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13067 lines
417 KiB
13067 lines
417 KiB
// arm.cc -- arm target support for gold. |
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// Copyright (C) 2009-2014 Free Software Foundation, Inc. |
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// Written by Doug Kwan <dougkwan@google.com> based on the i386 code |
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// by Ian Lance Taylor <iant@google.com>. |
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// This file also contains borrowed and adapted code from |
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// bfd/elf32-arm.c. |
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// This file is part of gold. |
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// This program is free software; you can redistribute it and/or modify |
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// it under the terms of the GNU General Public License as published by |
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// the Free Software Foundation; either version 3 of the License, or |
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// (at your option) any later version. |
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// This program is distributed in the hope that it will be useful, |
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// but WITHOUT ANY WARRANTY; without even the implied warranty of |
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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// GNU General Public License for more details. |
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// You should have received a copy of the GNU General Public License |
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// along with this program; if not, write to the Free Software |
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// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
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// MA 02110-1301, USA. |
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#include "gold.h" |
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#include <cstring> |
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#include <limits> |
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#include <cstdio> |
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#include <string> |
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#include <algorithm> |
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#include <map> |
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#include <utility> |
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#include <set> |
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#include "elfcpp.h" |
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#include "parameters.h" |
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#include "reloc.h" |
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#include "arm.h" |
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#include "object.h" |
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#include "symtab.h" |
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#include "layout.h" |
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#include "output.h" |
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#include "copy-relocs.h" |
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#include "target.h" |
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#include "target-reloc.h" |
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#include "target-select.h" |
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#include "tls.h" |
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#include "defstd.h" |
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#include "gc.h" |
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#include "attributes.h" |
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#include "arm-reloc-property.h" |
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#include "nacl.h" |
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namespace |
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{ |
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using namespace gold; |
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template<bool big_endian> |
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class Output_data_plt_arm; |
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template<bool big_endian> |
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class Output_data_plt_arm_short; |
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template<bool big_endian> |
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class Output_data_plt_arm_long; |
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template<bool big_endian> |
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class Stub_table; |
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template<bool big_endian> |
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class Arm_input_section; |
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class Arm_exidx_cantunwind; |
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class Arm_exidx_merged_section; |
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class Arm_exidx_fixup; |
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template<bool big_endian> |
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class Arm_output_section; |
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class Arm_exidx_input_section; |
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template<bool big_endian> |
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class Arm_relobj; |
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template<bool big_endian> |
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class Arm_relocate_functions; |
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template<bool big_endian> |
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class Arm_output_data_got; |
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template<bool big_endian> |
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class Target_arm; |
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// For convenience. |
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typedef elfcpp::Elf_types<32>::Elf_Addr Arm_address; |
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// Maximum branch offsets for ARM, THUMB and THUMB2. |
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const int32_t ARM_MAX_FWD_BRANCH_OFFSET = ((((1 << 23) - 1) << 2) + 8); |
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const int32_t ARM_MAX_BWD_BRANCH_OFFSET = ((-((1 << 23) << 2)) + 8); |
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const int32_t THM_MAX_FWD_BRANCH_OFFSET = ((1 << 22) -2 + 4); |
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const int32_t THM_MAX_BWD_BRANCH_OFFSET = (-(1 << 22) + 4); |
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const int32_t THM2_MAX_FWD_BRANCH_OFFSET = (((1 << 24) - 2) + 4); |
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const int32_t THM2_MAX_BWD_BRANCH_OFFSET = (-(1 << 24) + 4); |
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// Thread Control Block size. |
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const size_t ARM_TCB_SIZE = 8; |
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// The arm target class. |
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// |
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// This is a very simple port of gold for ARM-EABI. It is intended for |
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// supporting Android only for the time being. |
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// |
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// TODOs: |
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// - Implement all static relocation types documented in arm-reloc.def. |
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// - Make PLTs more flexible for different architecture features like |
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// Thumb-2 and BE8. |
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// There are probably a lot more. |
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// Ideally we would like to avoid using global variables but this is used |
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// very in many places and sometimes in loops. If we use a function |
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// returning a static instance of Arm_reloc_property_table, it will be very |
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// slow in an threaded environment since the static instance needs to be |
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// locked. The pointer is below initialized in the |
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// Target::do_select_as_default_target() hook so that we do not spend time |
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// building the table if we are not linking ARM objects. |
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// |
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// An alternative is to to process the information in arm-reloc.def in |
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// compilation time and generate a representation of it in PODs only. That |
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// way we can avoid initialization when the linker starts. |
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Arm_reloc_property_table* arm_reloc_property_table = NULL; |
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// Instruction template class. This class is similar to the insn_sequence |
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// struct in bfd/elf32-arm.c. |
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class Insn_template |
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{ |
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public: |
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// Types of instruction templates. |
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enum Type |
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{ |
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THUMB16_TYPE = 1, |
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// THUMB16_SPECIAL_TYPE is used by sub-classes of Stub for instruction |
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// templates with class-specific semantics. Currently this is used |
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// only by the Cortex_a8_stub class for handling condition codes in |
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// conditional branches. |
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THUMB16_SPECIAL_TYPE, |
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THUMB32_TYPE, |
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ARM_TYPE, |
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DATA_TYPE |
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}; |
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// Factory methods to create instruction templates in different formats. |
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static const Insn_template |
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thumb16_insn(uint32_t data) |
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{ return Insn_template(data, THUMB16_TYPE, elfcpp::R_ARM_NONE, 0); } |
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// A Thumb conditional branch, in which the proper condition is inserted |
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// when we build the stub. |
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static const Insn_template |
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thumb16_bcond_insn(uint32_t data) |
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{ return Insn_template(data, THUMB16_SPECIAL_TYPE, elfcpp::R_ARM_NONE, 1); } |
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static const Insn_template |
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thumb32_insn(uint32_t data) |
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{ return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_NONE, 0); } |
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static const Insn_template |
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thumb32_b_insn(uint32_t data, int reloc_addend) |
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{ |
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return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_THM_JUMP24, |
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reloc_addend); |
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} |
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static const Insn_template |
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arm_insn(uint32_t data) |
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{ return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_NONE, 0); } |
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static const Insn_template |
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arm_rel_insn(unsigned data, int reloc_addend) |
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{ return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_JUMP24, reloc_addend); } |
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static const Insn_template |
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data_word(unsigned data, unsigned int r_type, int reloc_addend) |
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{ return Insn_template(data, DATA_TYPE, r_type, reloc_addend); } |
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// Accessors. This class is used for read-only objects so no modifiers |
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// are provided. |
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uint32_t |
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data() const |
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{ return this->data_; } |
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// Return the instruction sequence type of this. |
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Type |
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type() const |
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{ return this->type_; } |
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// Return the ARM relocation type of this. |
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unsigned int |
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r_type() const |
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{ return this->r_type_; } |
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int32_t |
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reloc_addend() const |
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{ return this->reloc_addend_; } |
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// Return size of instruction template in bytes. |
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size_t |
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size() const; |
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// Return byte-alignment of instruction template. |
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unsigned |
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alignment() const; |
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private: |
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// We make the constructor private to ensure that only the factory |
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// methods are used. |
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inline |
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Insn_template(unsigned data, Type type, unsigned int r_type, int reloc_addend) |
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: data_(data), type_(type), r_type_(r_type), reloc_addend_(reloc_addend) |
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{ } |
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// Instruction specific data. This is used to store information like |
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// some of the instruction bits. |
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uint32_t data_; |
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// Instruction template type. |
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Type type_; |
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// Relocation type if there is a relocation or R_ARM_NONE otherwise. |
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unsigned int r_type_; |
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// Relocation addend. |
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int32_t reloc_addend_; |
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}; |
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// Macro for generating code to stub types. One entry per long/short |
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// branch stub |
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#define DEF_STUBS \ |
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DEF_STUB(long_branch_any_any) \ |
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DEF_STUB(long_branch_v4t_arm_thumb) \ |
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DEF_STUB(long_branch_thumb_only) \ |
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DEF_STUB(long_branch_v4t_thumb_thumb) \ |
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DEF_STUB(long_branch_v4t_thumb_arm) \ |
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DEF_STUB(short_branch_v4t_thumb_arm) \ |
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DEF_STUB(long_branch_any_arm_pic) \ |
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DEF_STUB(long_branch_any_thumb_pic) \ |
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DEF_STUB(long_branch_v4t_thumb_thumb_pic) \ |
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DEF_STUB(long_branch_v4t_arm_thumb_pic) \ |
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DEF_STUB(long_branch_v4t_thumb_arm_pic) \ |
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DEF_STUB(long_branch_thumb_only_pic) \ |
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DEF_STUB(a8_veneer_b_cond) \ |
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DEF_STUB(a8_veneer_b) \ |
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DEF_STUB(a8_veneer_bl) \ |
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DEF_STUB(a8_veneer_blx) \ |
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DEF_STUB(v4_veneer_bx) |
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// Stub types. |
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#define DEF_STUB(x) arm_stub_##x, |
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typedef enum |
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{ |
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arm_stub_none, |
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DEF_STUBS |
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// First reloc stub type. |
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arm_stub_reloc_first = arm_stub_long_branch_any_any, |
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// Last reloc stub type. |
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arm_stub_reloc_last = arm_stub_long_branch_thumb_only_pic, |
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// First Cortex-A8 stub type. |
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arm_stub_cortex_a8_first = arm_stub_a8_veneer_b_cond, |
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// Last Cortex-A8 stub type. |
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arm_stub_cortex_a8_last = arm_stub_a8_veneer_blx, |
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// Last stub type. |
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arm_stub_type_last = arm_stub_v4_veneer_bx |
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} Stub_type; |
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#undef DEF_STUB |
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// Stub template class. Templates are meant to be read-only objects. |
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// A stub template for a stub type contains all read-only attributes |
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// common to all stubs of the same type. |
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class Stub_template |
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{ |
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public: |
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Stub_template(Stub_type, const Insn_template*, size_t); |
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~Stub_template() |
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{ } |
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// Return stub type. |
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Stub_type |
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type() const |
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{ return this->type_; } |
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// Return an array of instruction templates. |
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const Insn_template* |
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insns() const |
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{ return this->insns_; } |
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// Return size of template in number of instructions. |
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size_t |
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insn_count() const |
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{ return this->insn_count_; } |
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// Return size of template in bytes. |
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size_t |
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size() const |
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{ return this->size_; } |
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// Return alignment of the stub template. |
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unsigned |
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alignment() const |
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{ return this->alignment_; } |
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// Return whether entry point is in thumb mode. |
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bool |
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entry_in_thumb_mode() const |
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{ return this->entry_in_thumb_mode_; } |
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// Return number of relocations in this template. |
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size_t |
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reloc_count() const |
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{ return this->relocs_.size(); } |
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// Return index of the I-th instruction with relocation. |
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size_t |
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reloc_insn_index(size_t i) const |
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{ |
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gold_assert(i < this->relocs_.size()); |
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return this->relocs_[i].first; |
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} |
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// Return the offset of the I-th instruction with relocation from the |
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// beginning of the stub. |
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section_size_type |
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reloc_offset(size_t i) const |
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{ |
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gold_assert(i < this->relocs_.size()); |
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return this->relocs_[i].second; |
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} |
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private: |
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// This contains information about an instruction template with a relocation |
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// and its offset from start of stub. |
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typedef std::pair<size_t, section_size_type> Reloc; |
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// A Stub_template may not be copied. We want to share templates as much |
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// as possible. |
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Stub_template(const Stub_template&); |
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Stub_template& operator=(const Stub_template&); |
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// Stub type. |
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Stub_type type_; |
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// Points to an array of Insn_templates. |
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const Insn_template* insns_; |
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// Number of Insn_templates in insns_[]. |
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size_t insn_count_; |
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// Size of templated instructions in bytes. |
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size_t size_; |
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// Alignment of templated instructions. |
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unsigned alignment_; |
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// Flag to indicate if entry is in thumb mode. |
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bool entry_in_thumb_mode_; |
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// A table of reloc instruction indices and offsets. We can find these by |
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// looking at the instruction templates but we pre-compute and then stash |
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// them here for speed. |
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std::vector<Reloc> relocs_; |
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}; |
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// |
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// A class for code stubs. This is a base class for different type of |
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// stubs used in the ARM target. |
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// |
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class Stub |
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{ |
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private: |
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static const section_offset_type invalid_offset = |
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static_cast<section_offset_type>(-1); |
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public: |
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Stub(const Stub_template* stub_template) |
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: stub_template_(stub_template), offset_(invalid_offset) |
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{ } |
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virtual |
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~Stub() |
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{ } |
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// Return the stub template. |
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const Stub_template* |
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stub_template() const |
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{ return this->stub_template_; } |
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// Return offset of code stub from beginning of its containing stub table. |
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section_offset_type |
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offset() const |
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{ |
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gold_assert(this->offset_ != invalid_offset); |
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return this->offset_; |
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} |
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// Set offset of code stub from beginning of its containing stub table. |
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void |
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set_offset(section_offset_type offset) |
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{ this->offset_ = offset; } |
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// Return the relocation target address of the i-th relocation in the |
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// stub. This must be defined in a child class. |
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Arm_address |
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reloc_target(size_t i) |
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{ return this->do_reloc_target(i); } |
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// Write a stub at output VIEW. BIG_ENDIAN select how a stub is written. |
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void |
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write(unsigned char* view, section_size_type view_size, bool big_endian) |
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{ this->do_write(view, view_size, big_endian); } |
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// Return the instruction for THUMB16_SPECIAL_TYPE instruction template |
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// for the i-th instruction. |
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uint16_t |
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thumb16_special(size_t i) |
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{ return this->do_thumb16_special(i); } |
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protected: |
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// This must be defined in the child class. |
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virtual Arm_address |
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do_reloc_target(size_t) = 0; |
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// This may be overridden in the child class. |
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virtual void |
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do_write(unsigned char* view, section_size_type view_size, bool big_endian) |
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{ |
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if (big_endian) |
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this->do_fixed_endian_write<true>(view, view_size); |
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else |
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this->do_fixed_endian_write<false>(view, view_size); |
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} |
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// This must be overridden if a child class uses the THUMB16_SPECIAL_TYPE |
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// instruction template. |
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virtual uint16_t |
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do_thumb16_special(size_t) |
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{ gold_unreachable(); } |
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private: |
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// A template to implement do_write. |
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template<bool big_endian> |
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void inline |
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do_fixed_endian_write(unsigned char*, section_size_type); |
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// Its template. |
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const Stub_template* stub_template_; |
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// Offset within the section of containing this stub. |
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section_offset_type offset_; |
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}; |
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// Reloc stub class. These are stubs we use to fix up relocation because |
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// of limited branch ranges. |
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class Reloc_stub : public Stub |
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{ |
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public: |
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static const unsigned int invalid_index = static_cast<unsigned int>(-1); |
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// We assume we never jump to this address. |
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static const Arm_address invalid_address = static_cast<Arm_address>(-1); |
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// Return destination address. |
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Arm_address |
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destination_address() const |
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{ |
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gold_assert(this->destination_address_ != this->invalid_address); |
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return this->destination_address_; |
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} |
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// Set destination address. |
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void |
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set_destination_address(Arm_address address) |
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{ |
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gold_assert(address != this->invalid_address); |
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this->destination_address_ = address; |
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} |
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// Reset destination address. |
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void |
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reset_destination_address() |
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{ this->destination_address_ = this->invalid_address; } |
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// Determine stub type for a branch of a relocation of R_TYPE going |
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// from BRANCH_ADDRESS to BRANCH_TARGET. If TARGET_IS_THUMB is set, |
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// the branch target is a thumb instruction. TARGET is used for look |
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// up ARM-specific linker settings. |
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static Stub_type |
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stub_type_for_reloc(unsigned int r_type, Arm_address branch_address, |
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Arm_address branch_target, bool target_is_thumb); |
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// Reloc_stub key. A key is logically a triplet of a stub type, a symbol |
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// and an addend. Since we treat global and local symbol differently, we |
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// use a Symbol object for a global symbol and a object-index pair for |
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// a local symbol. |
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class Key |
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{ |
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public: |
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// If SYMBOL is not null, this is a global symbol, we ignore RELOBJ and |
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// R_SYM. Otherwise, this is a local symbol and RELOBJ must non-NULL |
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// and R_SYM must not be invalid_index. |
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Key(Stub_type stub_type, const Symbol* symbol, const Relobj* relobj, |
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unsigned int r_sym, int32_t addend) |
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: stub_type_(stub_type), addend_(addend) |
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{ |
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if (symbol != NULL) |
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{ |
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this->r_sym_ = Reloc_stub::invalid_index; |
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this->u_.symbol = symbol; |
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} |
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else |
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{ |
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gold_assert(relobj != NULL && r_sym != invalid_index); |
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this->r_sym_ = r_sym; |
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this->u_.relobj = relobj; |
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} |
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} |
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~Key() |
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{ } |
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// Accessors: Keys are meant to be read-only object so no modifiers are |
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// provided. |
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// Return stub type. |
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Stub_type |
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stub_type() const |
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{ return this->stub_type_; } |
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// Return the local symbol index or invalid_index. |
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unsigned int |
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r_sym() const |
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{ return this->r_sym_; } |
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// Return the symbol if there is one. |
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const Symbol* |
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symbol() const |
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{ return this->r_sym_ == invalid_index ? this->u_.symbol : NULL; } |
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// Return the relobj if there is one. |
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const Relobj* |
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relobj() const |
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{ return this->r_sym_ != invalid_index ? this->u_.relobj : NULL; } |
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|
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// Whether this equals to another key k. |
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bool |
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eq(const Key& k) const |
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{ |
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return ((this->stub_type_ == k.stub_type_) |
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&& (this->r_sym_ == k.r_sym_) |
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&& ((this->r_sym_ != Reloc_stub::invalid_index) |
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? (this->u_.relobj == k.u_.relobj) |
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: (this->u_.symbol == k.u_.symbol)) |
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&& (this->addend_ == k.addend_)); |
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} |
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// Return a hash value. |
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size_t |
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hash_value() const |
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{ |
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return (this->stub_type_ |
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^ this->r_sym_ |
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^ gold::string_hash<char>( |
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(this->r_sym_ != Reloc_stub::invalid_index) |
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? this->u_.relobj->name().c_str() |
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: this->u_.symbol->name()) |
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^ this->addend_); |
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} |
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// Functors for STL associative containers. |
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struct hash |
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{ |
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size_t |
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operator()(const Key& k) const |
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{ return k.hash_value(); } |
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}; |
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|
|
struct equal_to |
|
{ |
|
bool |
|
operator()(const Key& k1, const Key& k2) const |
|
{ return k1.eq(k2); } |
|
}; |
|
|
|
// Name of key. This is mainly for debugging. |
|
std::string |
|
name() const; |
|
|
|
private: |
|
// Stub type. |
|
Stub_type stub_type_; |
|
// If this is a local symbol, this is the index in the defining object. |
|
// Otherwise, it is invalid_index for a global symbol. |
|
unsigned int r_sym_; |
|
// If r_sym_ is an invalid index, this points to a global symbol. |
|
// Otherwise, it points to a relobj. We used the unsized and target |
|
// independent Symbol and Relobj classes instead of Sized_symbol<32> and |
|
// Arm_relobj, in order to avoid making the stub class a template |
|
// as most of the stub machinery is endianness-neutral. However, it |
|
// may require a bit of casting done by users of this class. |
|
union |
|
{ |
|
const Symbol* symbol; |
|
const Relobj* relobj; |
|
} u_; |
|
// Addend associated with a reloc. |
|
int32_t addend_; |
|
}; |
|
|
|
protected: |
|
// Reloc_stubs are created via a stub factory. So these are protected. |
|
Reloc_stub(const Stub_template* stub_template) |
|
: Stub(stub_template), destination_address_(invalid_address) |
|
{ } |
|
|
|
~Reloc_stub() |
|
{ } |
|
|
|
friend class Stub_factory; |
|
|
|
// Return the relocation target address of the i-th relocation in the |
|
// stub. |
|
Arm_address |
|
do_reloc_target(size_t i) |
|
{ |
|
// All reloc stub have only one relocation. |
|
gold_assert(i == 0); |
|
return this->destination_address_; |
|
} |
|
|
|
private: |
|
// Address of destination. |
|
Arm_address destination_address_; |
|
}; |
|
|
|
// Cortex-A8 stub class. We need a Cortex-A8 stub to redirect any 32-bit |
|
// THUMB branch that meets the following conditions: |
|
// |
|
// 1. The branch straddles across a page boundary. i.e. lower 12-bit of |
|
// branch address is 0xffe. |
|
// 2. The branch target address is in the same page as the first word of the |
|
// branch. |
|
// 3. The branch follows a 32-bit instruction which is not a branch. |
|
// |
|
// To do the fix up, we need to store the address of the branch instruction |
|
// and its target at least. We also need to store the original branch |
|
// instruction bits for the condition code in a conditional branch. The |
|
// condition code is used in a special instruction template. We also want |
|
// to identify input sections needing Cortex-A8 workaround quickly. We store |
|
// extra information about object and section index of the code section |
|
// containing a branch being fixed up. The information is used to mark |
|
// the code section when we finalize the Cortex-A8 stubs. |
|
// |
|
|
|
class Cortex_a8_stub : public Stub |
|
{ |
|
public: |
|
~Cortex_a8_stub() |
|
{ } |
|
|
|
// Return the object of the code section containing the branch being fixed |
|
// up. |
|
Relobj* |
|
relobj() const |
|
{ return this->relobj_; } |
|
|
|
// Return the section index of the code section containing the branch being |
|
// fixed up. |
|
unsigned int |
|
shndx() const |
|
{ return this->shndx_; } |
|
|
|
// Return the source address of stub. This is the address of the original |
|
// branch instruction. LSB is 1 always set to indicate that it is a THUMB |
|
// instruction. |
|
Arm_address |
|
source_address() const |
|
{ return this->source_address_; } |
|
|
|
// Return the destination address of the stub. This is the branch taken |
|
// address of the original branch instruction. LSB is 1 if it is a THUMB |
|
// instruction address. |
|
Arm_address |
|
destination_address() const |
|
{ return this->destination_address_; } |
|
|
|
// Return the instruction being fixed up. |
|
uint32_t |
|
original_insn() const |
|
{ return this->original_insn_; } |
|
|
|
protected: |
|
// Cortex_a8_stubs are created via a stub factory. So these are protected. |
|
Cortex_a8_stub(const Stub_template* stub_template, Relobj* relobj, |
|
unsigned int shndx, Arm_address source_address, |
|
Arm_address destination_address, uint32_t original_insn) |
|
: Stub(stub_template), relobj_(relobj), shndx_(shndx), |
|
source_address_(source_address | 1U), |
|
destination_address_(destination_address), |
|
original_insn_(original_insn) |
|
{ } |
|
|
|
friend class Stub_factory; |
|
|
|
// Return the relocation target address of the i-th relocation in the |
|
// stub. |
|
Arm_address |
|
do_reloc_target(size_t i) |
|
{ |
|
if (this->stub_template()->type() == arm_stub_a8_veneer_b_cond) |
|
{ |
|
// The conditional branch veneer has two relocations. |
|
gold_assert(i < 2); |
|
return i == 0 ? this->source_address_ + 4 : this->destination_address_; |
|
} |
|
else |
|
{ |
|
// All other Cortex-A8 stubs have only one relocation. |
|
gold_assert(i == 0); |
|
return this->destination_address_; |
|
} |
|
} |
|
|
|
// Return an instruction for the THUMB16_SPECIAL_TYPE instruction template. |
|
uint16_t |
|
do_thumb16_special(size_t); |
|
|
|
private: |
|
// Object of the code section containing the branch being fixed up. |
|
Relobj* relobj_; |
|
// Section index of the code section containing the branch begin fixed up. |
|
unsigned int shndx_; |
|
// Source address of original branch. |
|
Arm_address source_address_; |
|
// Destination address of the original branch. |
|
Arm_address destination_address_; |
|
// Original branch instruction. This is needed for copying the condition |
|
// code from a condition branch to its stub. |
|
uint32_t original_insn_; |
|
}; |
|
|
|
// ARMv4 BX Rx branch relocation stub class. |
|
class Arm_v4bx_stub : public Stub |
|
{ |
|
public: |
|
~Arm_v4bx_stub() |
|
{ } |
|
|
|
// Return the associated register. |
|
uint32_t |
|
reg() const |
|
{ return this->reg_; } |
|
|
|
protected: |
|
// Arm V4BX stubs are created via a stub factory. So these are protected. |
|
Arm_v4bx_stub(const Stub_template* stub_template, const uint32_t reg) |
|
: Stub(stub_template), reg_(reg) |
|
{ } |
|
|
|
friend class Stub_factory; |
|
|
|
// Return the relocation target address of the i-th relocation in the |
|
// stub. |
|
Arm_address |
|
do_reloc_target(size_t) |
|
{ gold_unreachable(); } |
|
|
|
// This may be overridden in the child class. |
|
virtual void |
|
do_write(unsigned char* view, section_size_type view_size, bool big_endian) |
|
{ |
|
if (big_endian) |
|
this->do_fixed_endian_v4bx_write<true>(view, view_size); |
|
else |
|
this->do_fixed_endian_v4bx_write<false>(view, view_size); |
|
} |
|
|
|
private: |
|
// A template to implement do_write. |
|
template<bool big_endian> |
|
void inline |
|
do_fixed_endian_v4bx_write(unsigned char* view, section_size_type) |
|
{ |
|
const Insn_template* insns = this->stub_template()->insns(); |
|
elfcpp::Swap<32, big_endian>::writeval(view, |
|
(insns[0].data() |
|
+ (this->reg_ << 16))); |
|
view += insns[0].size(); |
|
elfcpp::Swap<32, big_endian>::writeval(view, |
|
(insns[1].data() + this->reg_)); |
|
view += insns[1].size(); |
|
elfcpp::Swap<32, big_endian>::writeval(view, |
|
(insns[2].data() + this->reg_)); |
|
} |
|
|
|
// A register index (r0-r14), which is associated with the stub. |
|
uint32_t reg_; |
|
}; |
|
|
|
// Stub factory class. |
|
|
|
class Stub_factory |
|
{ |
|
public: |
|
// Return the unique instance of this class. |
|
static const Stub_factory& |
|
get_instance() |
|
{ |
|
static Stub_factory singleton; |
|
return singleton; |
|
} |
|
|
|
// Make a relocation stub. |
|
Reloc_stub* |
|
make_reloc_stub(Stub_type stub_type) const |
|
{ |
|
gold_assert(stub_type >= arm_stub_reloc_first |
|
&& stub_type <= arm_stub_reloc_last); |
|
return new Reloc_stub(this->stub_templates_[stub_type]); |
|
} |
|
|
|
// Make a Cortex-A8 stub. |
|
Cortex_a8_stub* |
|
make_cortex_a8_stub(Stub_type stub_type, Relobj* relobj, unsigned int shndx, |
|
Arm_address source, Arm_address destination, |
|
uint32_t original_insn) const |
|
{ |
|
gold_assert(stub_type >= arm_stub_cortex_a8_first |
|
&& stub_type <= arm_stub_cortex_a8_last); |
|
return new Cortex_a8_stub(this->stub_templates_[stub_type], relobj, shndx, |
|
source, destination, original_insn); |
|
} |
|
|
|
// Make an ARM V4BX relocation stub. |
|
// This method creates a stub from the arm_stub_v4_veneer_bx template only. |
|
Arm_v4bx_stub* |
|
make_arm_v4bx_stub(uint32_t reg) const |
|
{ |
|
gold_assert(reg < 0xf); |
|
return new Arm_v4bx_stub(this->stub_templates_[arm_stub_v4_veneer_bx], |
|
reg); |
|
} |
|
|
|
private: |
|
// Constructor and destructor are protected since we only return a single |
|
// instance created in Stub_factory::get_instance(). |
|
|
|
Stub_factory(); |
|
|
|
// A Stub_factory may not be copied since it is a singleton. |
|
Stub_factory(const Stub_factory&); |
|
Stub_factory& operator=(Stub_factory&); |
|
|
|
// Stub templates. These are initialized in the constructor. |
|
const Stub_template* stub_templates_[arm_stub_type_last+1]; |
|
}; |
|
|
|
// A class to hold stubs for the ARM target. |
|
|
|
template<bool big_endian> |
|
class Stub_table : public Output_data |
|
{ |
|
public: |
|
Stub_table(Arm_input_section<big_endian>* owner) |
|
: Output_data(), owner_(owner), reloc_stubs_(), reloc_stubs_size_(0), |
|
reloc_stubs_addralign_(1), cortex_a8_stubs_(), arm_v4bx_stubs_(0xf), |
|
prev_data_size_(0), prev_addralign_(1), padding_(0) |
|
{ } |
|
|
|
~Stub_table() |
|
{ } |
|
|
|
// Owner of this stub table. |
|
Arm_input_section<big_endian>* |
|
owner() const |
|
{ return this->owner_; } |
|
|
|
// Whether this stub table is empty. |
|
bool |
|
empty() const |
|
{ |
|
return (this->reloc_stubs_.empty() |
|
&& this->cortex_a8_stubs_.empty() |
|
&& this->arm_v4bx_stubs_.empty()); |
|
} |
|
|
|
// Return the current data size. |
|
off_t |
|
current_data_size() const |
|
{ return this->current_data_size_for_child(); } |
|
|
|
// Add a STUB using KEY. The caller is responsible for avoiding addition |
|
// if a STUB with the same key has already been added. |
|
void |
|
add_reloc_stub(Reloc_stub* stub, const Reloc_stub::Key& key) |
|
{ |
|
const Stub_template* stub_template = stub->stub_template(); |
|
gold_assert(stub_template->type() == key.stub_type()); |
|
this->reloc_stubs_[key] = stub; |
|
|
|
// Assign stub offset early. We can do this because we never remove |
|
// reloc stubs and they are in the beginning of the stub table. |
|
uint64_t align = stub_template->alignment(); |
|
this->reloc_stubs_size_ = align_address(this->reloc_stubs_size_, align); |
|
stub->set_offset(this->reloc_stubs_size_); |
|
this->reloc_stubs_size_ += stub_template->size(); |
|
this->reloc_stubs_addralign_ = |
|
std::max(this->reloc_stubs_addralign_, align); |
|
} |
|
|
|
// Add a Cortex-A8 STUB that fixes up a THUMB branch at ADDRESS. |
|
// The caller is responsible for avoiding addition if a STUB with the same |
|
// address has already been added. |
|
void |
|
add_cortex_a8_stub(Arm_address address, Cortex_a8_stub* stub) |
|
{ |
|
std::pair<Arm_address, Cortex_a8_stub*> value(address, stub); |
|
this->cortex_a8_stubs_.insert(value); |
|
} |
|
|
|
// Add an ARM V4BX relocation stub. A register index will be retrieved |
|
// from the stub. |
|
void |
|
add_arm_v4bx_stub(Arm_v4bx_stub* stub) |
|
{ |
|
gold_assert(stub != NULL && this->arm_v4bx_stubs_[stub->reg()] == NULL); |
|
this->arm_v4bx_stubs_[stub->reg()] = stub; |
|
} |
|
|
|
// Remove all Cortex-A8 stubs. |
|
void |
|
remove_all_cortex_a8_stubs(); |
|
|
|
// Look up a relocation stub using KEY. Return NULL if there is none. |
|
Reloc_stub* |
|
find_reloc_stub(const Reloc_stub::Key& key) const |
|
{ |
|
typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.find(key); |
|
return (p != this->reloc_stubs_.end()) ? p->second : NULL; |
|
} |
|
|
|
// Look up an arm v4bx relocation stub using the register index. |
|
// Return NULL if there is none. |
|
Arm_v4bx_stub* |
|
find_arm_v4bx_stub(const uint32_t reg) const |
|
{ |
|
gold_assert(reg < 0xf); |
|
return this->arm_v4bx_stubs_[reg]; |
|
} |
|
|
|
// Relocate stubs in this stub table. |
|
void |
|
relocate_stubs(const Relocate_info<32, big_endian>*, |
|
Target_arm<big_endian>*, Output_section*, |
|
unsigned char*, Arm_address, section_size_type); |
|
|
|
// Update data size and alignment at the end of a relaxation pass. Return |
|
// true if either data size or alignment is different from that of the |
|
// previous relaxation pass. |
|
bool |
|
update_data_size_and_addralign(); |
|
|
|
// Finalize stubs. Set the offsets of all stubs and mark input sections |
|
// needing the Cortex-A8 workaround. |
|
void |
|
finalize_stubs(); |
|
|
|
// Apply Cortex-A8 workaround to an address range. |
|
void |
|
apply_cortex_a8_workaround_to_address_range(Target_arm<big_endian>*, |
|
unsigned char*, Arm_address, |
|
section_size_type); |
|
|
|
protected: |
|
// Write out section contents. |
|
void |
|
do_write(Output_file*); |
|
|
|
// Return the required alignment. |
|
uint64_t |
|
do_addralign() const |
|
{ return this->prev_addralign_; } |
|
|
|
// Reset address and file offset. |
|
void |
|
do_reset_address_and_file_offset() |
|
{ |
|
this->set_current_data_size_for_child( |
|
this->prev_data_size_ + this->padding_); |
|
} |
|
|
|
// Set final data size. |
|
void |
|
set_final_data_size() |
|
{ this->set_data_size(this->current_data_size()); } |
|
|
|
// Relocate one stub. |
|
void |
|
relocate_stub(Stub*, const Relocate_info<32, big_endian>*, |
|
Target_arm<big_endian>*, Output_section*, |
|
unsigned char*, Arm_address, section_size_type); |
|
|
|
// Unordered map of relocation stubs. |
|
typedef |
|
Unordered_map<Reloc_stub::Key, Reloc_stub*, Reloc_stub::Key::hash, |
|
Reloc_stub::Key::equal_to> |
|
Reloc_stub_map; |
|
|
|
// List of Cortex-A8 stubs ordered by addresses of branches being |
|
// fixed up in output. |
|
typedef std::map<Arm_address, Cortex_a8_stub*> Cortex_a8_stub_list; |
|
// List of Arm V4BX relocation stubs ordered by associated registers. |
|
typedef std::vector<Arm_v4bx_stub*> Arm_v4bx_stub_list; |
|
|
|
// Owner of this stub table. |
|
Arm_input_section<big_endian>* owner_; |
|
// The relocation stubs. |
|
Reloc_stub_map reloc_stubs_; |
|
// Size of reloc stubs. |
|
off_t reloc_stubs_size_; |
|
// Maximum address alignment of reloc stubs. |
|
uint64_t reloc_stubs_addralign_; |
|
// The cortex_a8_stubs. |
|
Cortex_a8_stub_list cortex_a8_stubs_; |
|
// The Arm V4BX relocation stubs. |
|
Arm_v4bx_stub_list arm_v4bx_stubs_; |
|
// data size of this in the previous pass. |
|
off_t prev_data_size_; |
|
// address alignment of this in the previous pass. |
|
uint64_t prev_addralign_; |
|
off_t padding_; |
|
}; |
|
|
|
// Arm_exidx_cantunwind class. This represents an EXIDX_CANTUNWIND entry |
|
// we add to the end of an EXIDX input section that goes into the output. |
|
|
|
class Arm_exidx_cantunwind : public Output_section_data |
|
{ |
|
public: |
|
Arm_exidx_cantunwind(Relobj* relobj, unsigned int shndx) |
|
: Output_section_data(8, 4, true), relobj_(relobj), shndx_(shndx) |
|
{ } |
|
|
|
// Return the object containing the section pointed by this. |
|
Relobj* |
|
relobj() const |
|
{ return this->relobj_; } |
|
|
|
// Return the section index of the section pointed by this. |
|
unsigned int |
|
shndx() const |
|
{ return this->shndx_; } |
|
|
|
protected: |
|
void |
|
do_write(Output_file* of) |
|
{ |
|
if (parameters->target().is_big_endian()) |
|
this->do_fixed_endian_write<true>(of); |
|
else |
|
this->do_fixed_endian_write<false>(of); |
|
} |
|
|
|
// Write to a map file. |
|
void |
|
do_print_to_mapfile(Mapfile* mapfile) const |
|
{ mapfile->print_output_data(this, _("** ARM cantunwind")); } |
|
|
|
private: |
|
// Implement do_write for a given endianness. |
|
template<bool big_endian> |
|
void inline |
|
do_fixed_endian_write(Output_file*); |
|
|
|
// The object containing the section pointed by this. |
|
Relobj* relobj_; |
|
// The section index of the section pointed by this. |
|
unsigned int shndx_; |
|
}; |
|
|
|
// During EXIDX coverage fix-up, we compact an EXIDX section. The |
|
// Offset map is used to map input section offset within the EXIDX section |
|
// to the output offset from the start of this EXIDX section. |
|
|
|
typedef std::map<section_offset_type, section_offset_type> |
|
Arm_exidx_section_offset_map; |
|
|
|
// Arm_exidx_merged_section class. This represents an EXIDX input section |
|
// with some of its entries merged. |
|
|
|
class Arm_exidx_merged_section : public Output_relaxed_input_section |
|
{ |
|
public: |
|
// Constructor for Arm_exidx_merged_section. |
|
// EXIDX_INPUT_SECTION points to the unmodified EXIDX input section. |
|
// SECTION_OFFSET_MAP points to a section offset map describing how |
|
// parts of the input section are mapped to output. DELETED_BYTES is |
|
// the number of bytes deleted from the EXIDX input section. |
|
Arm_exidx_merged_section( |
|
const Arm_exidx_input_section& exidx_input_section, |
|
const Arm_exidx_section_offset_map& section_offset_map, |
|
uint32_t deleted_bytes); |
|
|
|
// Build output contents. |
|
void |
|
build_contents(const unsigned char*, section_size_type); |
|
|
|
// Return the original EXIDX input section. |
|
const Arm_exidx_input_section& |
|
exidx_input_section() const |
|
{ return this->exidx_input_section_; } |
|
|
|
// Return the section offset map. |
|
const Arm_exidx_section_offset_map& |
|
section_offset_map() const |
|
{ return this->section_offset_map_; } |
|
|
|
protected: |
|
// Write merged section into file OF. |
|
void |
|
do_write(Output_file* of); |
|
|
|
bool |
|
do_output_offset(const Relobj*, unsigned int, section_offset_type, |
|
section_offset_type*) const; |
|
|
|
private: |
|
// Original EXIDX input section. |
|
const Arm_exidx_input_section& exidx_input_section_; |
|
// Section offset map. |
|
const Arm_exidx_section_offset_map& section_offset_map_; |
|
// Merged section contents. We need to keep build the merged section |
|
// and save it here to avoid accessing the original EXIDX section when |
|
// we cannot lock the sections' object. |
|
unsigned char* section_contents_; |
|
}; |
|
|
|
// A class to wrap an ordinary input section containing executable code. |
|
|
|
template<bool big_endian> |
|
class Arm_input_section : public Output_relaxed_input_section |
|
{ |
|
public: |
|
Arm_input_section(Relobj* relobj, unsigned int shndx) |
|
: Output_relaxed_input_section(relobj, shndx, 1), |
|
original_addralign_(1), original_size_(0), stub_table_(NULL), |
|
original_contents_(NULL) |
|
{ } |
|
|
|
~Arm_input_section() |
|
{ delete[] this->original_contents_; } |
|
|
|
// Initialize. |
|
void |
|
init(); |
|
|
|
// Whether this is a stub table owner. |
|
bool |
|
is_stub_table_owner() const |
|
{ return this->stub_table_ != NULL && this->stub_table_->owner() == this; } |
|
|
|
// Return the stub table. |
|
Stub_table<big_endian>* |
|
stub_table() const |
|
{ return this->stub_table_; } |
|
|
|
// Set the stub_table. |
|
void |
|
set_stub_table(Stub_table<big_endian>* stub_table) |
|
{ this->stub_table_ = stub_table; } |
|
|
|
// Downcast a base pointer to an Arm_input_section pointer. This is |
|
// not type-safe but we only use Arm_input_section not the base class. |
|
static Arm_input_section<big_endian>* |
|
as_arm_input_section(Output_relaxed_input_section* poris) |
|
{ return static_cast<Arm_input_section<big_endian>*>(poris); } |
|
|
|
// Return the original size of the section. |
|
uint32_t |
|
original_size() const |
|
{ return this->original_size_; } |
|
|
|
protected: |
|
// Write data to output file. |
|
void |
|
do_write(Output_file*); |
|
|
|
// Return required alignment of this. |
|
uint64_t |
|
do_addralign() const |
|
{ |
|
if (this->is_stub_table_owner()) |
|
return std::max(this->stub_table_->addralign(), |
|
static_cast<uint64_t>(this->original_addralign_)); |
|
else |
|
return this->original_addralign_; |
|
} |
|
|
|
// Finalize data size. |
|
void |
|
set_final_data_size(); |
|
|
|
// Reset address and file offset. |
|
void |
|
do_reset_address_and_file_offset(); |
|
|
|
// Output offset. |
|
bool |
|
do_output_offset(const Relobj* object, unsigned int shndx, |
|
section_offset_type offset, |
|
section_offset_type* poutput) const |
|
{ |
|
if ((object == this->relobj()) |
|
&& (shndx == this->shndx()) |
|
&& (offset >= 0) |
|
&& (offset <= |
|
convert_types<section_offset_type, uint32_t>(this->original_size_))) |
|
{ |
|
*poutput = offset; |
|
return true; |
|
} |
|
else |
|
return false; |
|
} |
|
|
|
private: |
|
// Copying is not allowed. |
|
Arm_input_section(const Arm_input_section&); |
|
Arm_input_section& operator=(const Arm_input_section&); |
|
|
|
// Address alignment of the original input section. |
|
uint32_t original_addralign_; |
|
// Section size of the original input section. |
|
uint32_t original_size_; |
|
// Stub table. |
|
Stub_table<big_endian>* stub_table_; |
|
// Original section contents. We have to make a copy here since the file |
|
// containing the original section may not be locked when we need to access |
|
// the contents. |
|
unsigned char* original_contents_; |
|
}; |
|
|
|
// Arm_exidx_fixup class. This is used to define a number of methods |
|
// and keep states for fixing up EXIDX coverage. |
|
|
|
class Arm_exidx_fixup |
|
{ |
|
public: |
|
Arm_exidx_fixup(Output_section* exidx_output_section, |
|
bool merge_exidx_entries = true) |
|
: exidx_output_section_(exidx_output_section), last_unwind_type_(UT_NONE), |
|
last_inlined_entry_(0), last_input_section_(NULL), |
|
section_offset_map_(NULL), first_output_text_section_(NULL), |
|
merge_exidx_entries_(merge_exidx_entries) |
|
{ } |
|
|
|
~Arm_exidx_fixup() |
|
{ delete this->section_offset_map_; } |
|
|
|
// Process an EXIDX section for entry merging. SECTION_CONTENTS points |
|
// to the EXIDX contents and SECTION_SIZE is the size of the contents. Return |
|
// number of bytes to be deleted in output. If parts of the input EXIDX |
|
// section are merged a heap allocated Arm_exidx_section_offset_map is store |
|
// in the located PSECTION_OFFSET_MAP. The caller owns the map and is |
|
// responsible for releasing it. |
|
template<bool big_endian> |
|
uint32_t |
|
process_exidx_section(const Arm_exidx_input_section* exidx_input_section, |
|
const unsigned char* section_contents, |
|
section_size_type section_size, |
|
Arm_exidx_section_offset_map** psection_offset_map); |
|
|
|
// Append an EXIDX_CANTUNWIND entry pointing at the end of the last |
|
// input section, if there is not one already. |
|
void |
|
add_exidx_cantunwind_as_needed(); |
|
|
|
// Return the output section for the text section which is linked to the |
|
// first exidx input in output. |
|
Output_section* |
|
first_output_text_section() const |
|
{ return this->first_output_text_section_; } |
|
|
|
private: |
|
// Copying is not allowed. |
|
Arm_exidx_fixup(const Arm_exidx_fixup&); |
|
Arm_exidx_fixup& operator=(const Arm_exidx_fixup&); |
|
|
|
// Type of EXIDX unwind entry. |
|
enum Unwind_type |
|
{ |
|
// No type. |
|
UT_NONE, |
|
// EXIDX_CANTUNWIND. |
|
UT_EXIDX_CANTUNWIND, |
|
// Inlined entry. |
|
UT_INLINED_ENTRY, |
|
// Normal entry. |
|
UT_NORMAL_ENTRY, |
|
}; |
|
|
|
// Process an EXIDX entry. We only care about the second word of the |
|
// entry. Return true if the entry can be deleted. |
|
bool |
|
process_exidx_entry(uint32_t second_word); |
|
|
|
// Update the current section offset map during EXIDX section fix-up. |
|
// If there is no map, create one. INPUT_OFFSET is the offset of a |
|
// reference point, DELETED_BYTES is the number of deleted by in the |
|
// section so far. If DELETE_ENTRY is true, the reference point and |
|
// all offsets after the previous reference point are discarded. |
|
void |
|
update_offset_map(section_offset_type input_offset, |
|
section_size_type deleted_bytes, bool delete_entry); |
|
|
|
// EXIDX output section. |
|
Output_section* exidx_output_section_; |
|
// Unwind type of the last EXIDX entry processed. |
|
Unwind_type last_unwind_type_; |
|
// Last seen inlined EXIDX entry. |
|
uint32_t last_inlined_entry_; |
|
// Last processed EXIDX input section. |
|
const Arm_exidx_input_section* last_input_section_; |
|
// Section offset map created in process_exidx_section. |
|
Arm_exidx_section_offset_map* section_offset_map_; |
|
// Output section for the text section which is linked to the first exidx |
|
// input in output. |
|
Output_section* first_output_text_section_; |
|
|
|
bool merge_exidx_entries_; |
|
}; |
|
|
|
// Arm output section class. This is defined mainly to add a number of |
|
// stub generation methods. |
|
|
|
template<bool big_endian> |
|
class Arm_output_section : public Output_section |
|
{ |
|
public: |
|
typedef std::vector<std::pair<Relobj*, unsigned int> > Text_section_list; |
|
|
|
// We need to force SHF_LINK_ORDER in a SHT_ARM_EXIDX section. |
|
Arm_output_section(const char* name, elfcpp::Elf_Word type, |
|
elfcpp::Elf_Xword flags) |
|
: Output_section(name, type, |
|
(type == elfcpp::SHT_ARM_EXIDX |
|
? flags | elfcpp::SHF_LINK_ORDER |
|
: flags)) |
|
{ |
|
if (type == elfcpp::SHT_ARM_EXIDX) |
|
this->set_always_keeps_input_sections(); |
|
} |
|
|
|
~Arm_output_section() |
|
{ } |
|
|
|
// Group input sections for stub generation. |
|
void |
|
group_sections(section_size_type, bool, Target_arm<big_endian>*, const Task*); |
|
|
|
// Downcast a base pointer to an Arm_output_section pointer. This is |
|
// not type-safe but we only use Arm_output_section not the base class. |
|
static Arm_output_section<big_endian>* |
|
as_arm_output_section(Output_section* os) |
|
{ return static_cast<Arm_output_section<big_endian>*>(os); } |
|
|
|
// Append all input text sections in this into LIST. |
|
void |
|
append_text_sections_to_list(Text_section_list* list); |
|
|
|
// Fix EXIDX coverage of this EXIDX output section. SORTED_TEXT_SECTION |
|
// is a list of text input sections sorted in ascending order of their |
|
// output addresses. |
|
void |
|
fix_exidx_coverage(Layout* layout, |
|
const Text_section_list& sorted_text_section, |
|
Symbol_table* symtab, |
|
bool merge_exidx_entries, |
|
const Task* task); |
|
|
|
// Link an EXIDX section into its corresponding text section. |
|
void |
|
set_exidx_section_link(); |
|
|
|
private: |
|
// For convenience. |
|
typedef Output_section::Input_section Input_section; |
|
typedef Output_section::Input_section_list Input_section_list; |
|
|
|
// Create a stub group. |
|
void create_stub_group(Input_section_list::const_iterator, |
|
Input_section_list::const_iterator, |
|
Input_section_list::const_iterator, |
|
Target_arm<big_endian>*, |
|
std::vector<Output_relaxed_input_section*>*, |
|
const Task* task); |
|
}; |
|
|
|
// Arm_exidx_input_section class. This represents an EXIDX input section. |
|
|
|
class Arm_exidx_input_section |
|
{ |
|
public: |
|
static const section_offset_type invalid_offset = |
|
static_cast<section_offset_type>(-1); |
|
|
|
Arm_exidx_input_section(Relobj* relobj, unsigned int shndx, |
|
unsigned int link, uint32_t size, |
|
uint32_t addralign, uint32_t text_size) |
|
: relobj_(relobj), shndx_(shndx), link_(link), size_(size), |
|
addralign_(addralign), text_size_(text_size), has_errors_(false) |
|
{ } |
|
|
|
~Arm_exidx_input_section() |
|
{ } |
|
|
|
// Accessors: This is a read-only class. |
|
|
|
// Return the object containing this EXIDX input section. |
|
Relobj* |
|
relobj() const |
|
{ return this->relobj_; } |
|
|
|
// Return the section index of this EXIDX input section. |
|
unsigned int |
|
shndx() const |
|
{ return this->shndx_; } |
|
|
|
// Return the section index of linked text section in the same object. |
|
unsigned int |
|
link() const |
|
{ return this->link_; } |
|
|
|
// Return size of the EXIDX input section. |
|
uint32_t |
|
size() const |
|
{ return this->size_; } |
|
|
|
// Return address alignment of EXIDX input section. |
|
uint32_t |
|
addralign() const |
|
{ return this->addralign_; } |
|
|
|
// Return size of the associated text input section. |
|
uint32_t |
|
text_size() const |
|
{ return this->text_size_; } |
|
|
|
// Whether there are any errors in the EXIDX input section. |
|
bool |
|
has_errors() const |
|
{ return this->has_errors_; } |
|
|
|
// Set has-errors flag. |
|
void |
|
set_has_errors() |
|
{ this->has_errors_ = true; } |
|
|
|
private: |
|
// Object containing this. |
|
Relobj* relobj_; |
|
// Section index of this. |
|
unsigned int shndx_; |
|
// text section linked to this in the same object. |
|
unsigned int link_; |
|
// Size of this. For ARM 32-bit is sufficient. |
|
uint32_t size_; |
|
// Address alignment of this. For ARM 32-bit is sufficient. |
|
uint32_t addralign_; |
|
// Size of associated text section. |
|
uint32_t text_size_; |
|
// Whether this has any errors. |
|
bool has_errors_; |
|
}; |
|
|
|
// Arm_relobj class. |
|
|
|
template<bool big_endian> |
|
class Arm_relobj : public Sized_relobj_file<32, big_endian> |
|
{ |
|
public: |
|
static const Arm_address invalid_address = static_cast<Arm_address>(-1); |
|
|
|
Arm_relobj(const std::string& name, Input_file* input_file, off_t offset, |
|
const typename elfcpp::Ehdr<32, big_endian>& ehdr) |
|
: Sized_relobj_file<32, big_endian>(name, input_file, offset, ehdr), |
|
stub_tables_(), local_symbol_is_thumb_function_(), |
|
attributes_section_data_(NULL), mapping_symbols_info_(), |
|
section_has_cortex_a8_workaround_(NULL), exidx_section_map_(), |
|
output_local_symbol_count_needs_update_(false), |
|
merge_flags_and_attributes_(true) |
|
{ } |
|
|
|
~Arm_relobj() |
|
{ delete this->attributes_section_data_; } |
|
|
|
// Return the stub table of the SHNDX-th section if there is one. |
|
Stub_table<big_endian>* |
|
stub_table(unsigned int shndx) const |
|
{ |
|
gold_assert(shndx < this->stub_tables_.size()); |
|
return this->stub_tables_[shndx]; |
|
} |
|
|
|
// Set STUB_TABLE to be the stub_table of the SHNDX-th section. |
|
void |
|
set_stub_table(unsigned int shndx, Stub_table<big_endian>* stub_table) |
|
{ |
|
gold_assert(shndx < this->stub_tables_.size()); |
|
this->stub_tables_[shndx] = stub_table; |
|
} |
|
|
|
// Whether a local symbol is a THUMB function. R_SYM is the symbol table |
|
// index. This is only valid after do_count_local_symbol is called. |
|
bool |
|
local_symbol_is_thumb_function(unsigned int r_sym) const |
|
{ |
|
gold_assert(r_sym < this->local_symbol_is_thumb_function_.size()); |
|
return this->local_symbol_is_thumb_function_[r_sym]; |
|
} |
|
|
|
// Scan all relocation sections for stub generation. |
|
void |
|
scan_sections_for_stubs(Target_arm<big_endian>*, const Symbol_table*, |
|
const Layout*); |
|
|
|
// Convert regular input section with index SHNDX to a relaxed section. |
|
void |
|
convert_input_section_to_relaxed_section(unsigned shndx) |
|
{ |
|
// The stubs have relocations and we need to process them after writing |
|
// out the stubs. So relocation now must follow section write. |
|
this->set_section_offset(shndx, -1ULL); |
|
this->set_relocs_must_follow_section_writes(); |
|
} |
|
|
|
// Downcast a base pointer to an Arm_relobj pointer. This is |
|
// not type-safe but we only use Arm_relobj not the base class. |
|
static Arm_relobj<big_endian>* |
|
as_arm_relobj(Relobj* relobj) |
|
{ return static_cast<Arm_relobj<big_endian>*>(relobj); } |
|
|
|
// Processor-specific flags in ELF file header. This is valid only after |
|
// reading symbols. |
|
elfcpp::Elf_Word |
|
processor_specific_flags() const |
|
{ return this->processor_specific_flags_; } |
|
|
|
// Attribute section data This is the contents of the .ARM.attribute section |
|
// if there is one. |
|
const Attributes_section_data* |
|
attributes_section_data() const |
|
{ return this->attributes_section_data_; } |
|
|
|
// Mapping symbol location. |
|
typedef std::pair<unsigned int, Arm_address> Mapping_symbol_position; |
|
|
|
// Functor for STL container. |
|
struct Mapping_symbol_position_less |
|
{ |
|
bool |
|
operator()(const Mapping_symbol_position& p1, |
|
const Mapping_symbol_position& p2) const |
|
{ |
|
return (p1.first < p2.first |
|
|| (p1.first == p2.first && p1.second < p2.second)); |
|
} |
|
}; |
|
|
|
// We only care about the first character of a mapping symbol, so |
|
// we only store that instead of the whole symbol name. |
|
typedef std::map<Mapping_symbol_position, char, |
|
Mapping_symbol_position_less> Mapping_symbols_info; |
|
|
|
// Whether a section contains any Cortex-A8 workaround. |
|
bool |
|
section_has_cortex_a8_workaround(unsigned int shndx) const |
|
{ |
|
return (this->section_has_cortex_a8_workaround_ != NULL |
|
&& (*this->section_has_cortex_a8_workaround_)[shndx]); |
|
} |
|
|
|
// Mark a section that has Cortex-A8 workaround. |
|
void |
|
mark_section_for_cortex_a8_workaround(unsigned int shndx) |
|
{ |
|
if (this->section_has_cortex_a8_workaround_ == NULL) |
|
this->section_has_cortex_a8_workaround_ = |
|
new std::vector<bool>(this->shnum(), false); |
|
(*this->section_has_cortex_a8_workaround_)[shndx] = true; |
|
} |
|
|
|
// Return the EXIDX section of an text section with index SHNDX or NULL |
|
// if the text section has no associated EXIDX section. |
|
const Arm_exidx_input_section* |
|
exidx_input_section_by_link(unsigned int shndx) const |
|
{ |
|
Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx); |
|
return ((p != this->exidx_section_map_.end() |
|
&& p->second->link() == shndx) |
|
? p->second |
|
: NULL); |
|
} |
|
|
|
// Return the EXIDX section with index SHNDX or NULL if there is none. |
|
const Arm_exidx_input_section* |
|
exidx_input_section_by_shndx(unsigned shndx) const |
|
{ |
|
Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx); |
|
return ((p != this->exidx_section_map_.end() |
|
&& p->second->shndx() == shndx) |
|
? p->second |
|
: NULL); |
|
} |
|
|
|
// Whether output local symbol count needs updating. |
|
bool |
|
output_local_symbol_count_needs_update() const |
|
{ return this->output_local_symbol_count_needs_update_; } |
|
|
|
// Set output_local_symbol_count_needs_update flag to be true. |
|
void |
|
set_output_local_symbol_count_needs_update() |
|
{ this->output_local_symbol_count_needs_update_ = true; } |
|
|
|
// Update output local symbol count at the end of relaxation. |
|
void |
|
update_output_local_symbol_count(); |
|
|
|
// Whether we want to merge processor-specific flags and attributes. |
|
bool |
|
merge_flags_and_attributes() const |
|
{ return this->merge_flags_and_attributes_; } |
|
|
|
// Export list of EXIDX section indices. |
|
void |
|
get_exidx_shndx_list(std::vector<unsigned int>* list) const |
|
{ |
|
list->clear(); |
|
for (Exidx_section_map::const_iterator p = this->exidx_section_map_.begin(); |
|
p != this->exidx_section_map_.end(); |
|
++p) |
|
{ |
|
if (p->second->shndx() == p->first) |
|
list->push_back(p->first); |
|
} |
|
// Sort list to make result independent of implementation of map. |
|
std::sort(list->begin(), list->end()); |
|
} |
|
|
|
protected: |
|
// Post constructor setup. |
|
void |
|
do_setup() |
|
{ |
|
// Call parent's setup method. |
|
Sized_relobj_file<32, big_endian>::do_setup(); |
|
|
|
// Initialize look-up tables. |
|
Stub_table_list empty_stub_table_list(this->shnum(), NULL); |
|
this->stub_tables_.swap(empty_stub_table_list); |
|
} |
|
|
|
// Count the local symbols. |
|
void |
|
do_count_local_symbols(Stringpool_template<char>*, |
|
Stringpool_template<char>*); |
|
|
|
void |
|
do_relocate_sections( |
|
const Symbol_table* symtab, const Layout* layout, |
|
const unsigned char* pshdrs, Output_file* of, |
|
typename Sized_relobj_file<32, big_endian>::Views* pivews); |
|
|
|
// Read the symbol information. |
|
void |
|
do_read_symbols(Read_symbols_data* sd); |
|
|
|
// Process relocs for garbage collection. |
|
void |
|
do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*); |
|
|
|
private: |
|
|
|
// Whether a section needs to be scanned for relocation stubs. |
|
bool |
|
section_needs_reloc_stub_scanning(const elfcpp::Shdr<32, big_endian>&, |
|
const Relobj::Output_sections&, |
|
const Symbol_table*, const unsigned char*); |
|
|
|
// Whether a section is a scannable text section. |
|
bool |
|
section_is_scannable(const elfcpp::Shdr<32, big_endian>&, unsigned int, |
|
const Output_section*, const Symbol_table*); |
|
|
|
// Whether a section needs to be scanned for the Cortex-A8 erratum. |
|
bool |
|
section_needs_cortex_a8_stub_scanning(const elfcpp::Shdr<32, big_endian>&, |
|
unsigned int, Output_section*, |
|
const Symbol_table*); |
|
|
|
// Scan a section for the Cortex-A8 erratum. |
|
void |
|
scan_section_for_cortex_a8_erratum(const elfcpp::Shdr<32, big_endian>&, |
|
unsigned int, Output_section*, |
|
Target_arm<big_endian>*); |
|
|
|
// Find the linked text section of an EXIDX section by looking at the |
|
// first relocation of the EXIDX section. PSHDR points to the section |
|
// headers of a relocation section and PSYMS points to the local symbols. |
|
// PSHNDX points to a location storing the text section index if found. |
|
// Return whether we can find the linked section. |
|
bool |
|
find_linked_text_section(const unsigned char* pshdr, |
|
const unsigned char* psyms, unsigned int* pshndx); |
|
|
|
// |
|
// Make a new Arm_exidx_input_section object for EXIDX section with |
|
// index SHNDX and section header SHDR. TEXT_SHNDX is the section |
|
// index of the linked text section. |
|
void |
|
make_exidx_input_section(unsigned int shndx, |
|
const elfcpp::Shdr<32, big_endian>& shdr, |
|
unsigned int text_shndx, |
|
const elfcpp::Shdr<32, big_endian>& text_shdr); |
|
|
|
// Return the output address of either a plain input section or a |
|
// relaxed input section. SHNDX is the section index. |
|
Arm_address |
|
simple_input_section_output_address(unsigned int, Output_section*); |
|
|
|
typedef std::vector<Stub_table<big_endian>*> Stub_table_list; |
|
typedef Unordered_map<unsigned int, const Arm_exidx_input_section*> |
|
Exidx_section_map; |
|
|
|
// List of stub tables. |
|
Stub_table_list stub_tables_; |
|
// Bit vector to tell if a local symbol is a thumb function or not. |
|
// This is only valid after do_count_local_symbol is called. |
|
std::vector<bool> local_symbol_is_thumb_function_; |
|
// processor-specific flags in ELF file header. |
|
elfcpp::Elf_Word processor_specific_flags_; |
|
// Object attributes if there is an .ARM.attributes section or NULL. |
|
Attributes_section_data* attributes_section_data_; |
|
// Mapping symbols information. |
|
Mapping_symbols_info mapping_symbols_info_; |
|
// Bitmap to indicate sections with Cortex-A8 workaround or NULL. |
|
std::vector<bool>* section_has_cortex_a8_workaround_; |
|
// Map a text section to its associated .ARM.exidx section, if there is one. |
|
Exidx_section_map exidx_section_map_; |
|
// Whether output local symbol count needs updating. |
|
bool output_local_symbol_count_needs_update_; |
|
// Whether we merge processor flags and attributes of this object to |
|
// output. |
|
bool merge_flags_and_attributes_; |
|
}; |
|
|
|
// Arm_dynobj class. |
|
|
|
template<bool big_endian> |
|
class Arm_dynobj : public Sized_dynobj<32, big_endian> |
|
{ |
|
public: |
|
Arm_dynobj(const std::string& name, Input_file* input_file, off_t offset, |
|
const elfcpp::Ehdr<32, big_endian>& ehdr) |
|
: Sized_dynobj<32, big_endian>(name, input_file, offset, ehdr), |
|
processor_specific_flags_(0), attributes_section_data_(NULL) |
|
{ } |
|
|
|
~Arm_dynobj() |
|
{ delete this->attributes_section_data_; } |
|
|
|
// Downcast a base pointer to an Arm_relobj pointer. This is |
|
// not type-safe but we only use Arm_relobj not the base class. |
|
static Arm_dynobj<big_endian>* |
|
as_arm_dynobj(Dynobj* dynobj) |
|
{ return static_cast<Arm_dynobj<big_endian>*>(dynobj); } |
|
|
|
// Processor-specific flags in ELF file header. This is valid only after |
|
// reading symbols. |
|
elfcpp::Elf_Word |
|
processor_specific_flags() const |
|
{ return this->processor_specific_flags_; } |
|
|
|
// Attributes section data. |
|
const Attributes_section_data* |
|
attributes_section_data() const |
|
{ return this->attributes_section_data_; } |
|
|
|
protected: |
|
// Read the symbol information. |
|
void |
|
do_read_symbols(Read_symbols_data* sd); |
|
|
|
private: |
|
// processor-specific flags in ELF file header. |
|
elfcpp::Elf_Word processor_specific_flags_; |
|
// Object attributes if there is an .ARM.attributes section or NULL. |
|
Attributes_section_data* attributes_section_data_; |
|
}; |
|
|
|
// Functor to read reloc addends during stub generation. |
|
|
|
template<int sh_type, bool big_endian> |
|
struct Stub_addend_reader |
|
{ |
|
// Return the addend for a relocation of a particular type. Depending |
|
// on whether this is a REL or RELA relocation, read the addend from a |
|
// view or from a Reloc object. |
|
elfcpp::Elf_types<32>::Elf_Swxword |
|
operator()( |
|
unsigned int /* r_type */, |
|
const unsigned char* /* view */, |
|
const typename Reloc_types<sh_type, |
|
32, big_endian>::Reloc& /* reloc */) const; |
|
}; |
|
|
|
// Specialized Stub_addend_reader for SHT_REL type relocation sections. |
|
|
|
template<bool big_endian> |
|
struct Stub_addend_reader<elfcpp::SHT_REL, big_endian> |
|
{ |
|
elfcpp::Elf_types<32>::Elf_Swxword |
|
operator()( |
|
unsigned int, |
|
const unsigned char*, |
|
const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const; |
|
}; |
|
|
|
// Specialized Stub_addend_reader for RELA type relocation sections. |
|
// We currently do not handle RELA type relocation sections but it is trivial |
|
// to implement the addend reader. This is provided for completeness and to |
|
// make it easier to add support for RELA relocation sections in the future. |
|
|
|
template<bool big_endian> |
|
struct Stub_addend_reader<elfcpp::SHT_RELA, big_endian> |
|
{ |
|
elfcpp::Elf_types<32>::Elf_Swxword |
|
operator()( |
|
unsigned int, |
|
const unsigned char*, |
|
const typename Reloc_types<elfcpp::SHT_RELA, 32, |
|
big_endian>::Reloc& reloc) const |
|
{ return reloc.get_r_addend(); } |
|
}; |
|
|
|
// Cortex_a8_reloc class. We keep record of relocation that may need |
|
// the Cortex-A8 erratum workaround. |
|
|
|
class Cortex_a8_reloc |
|
{ |
|
public: |
|
Cortex_a8_reloc(Reloc_stub* reloc_stub, unsigned r_type, |
|
Arm_address destination) |
|
: reloc_stub_(reloc_stub), r_type_(r_type), destination_(destination) |
|
{ } |
|
|
|
~Cortex_a8_reloc() |
|
{ } |
|
|
|
// Accessors: This is a read-only class. |
|
|
|
// Return the relocation stub associated with this relocation if there is |
|
// one. |
|
const Reloc_stub* |
|
reloc_stub() const |
|
{ return this->reloc_stub_; } |
|
|
|
// Return the relocation type. |
|
unsigned int |
|
r_type() const |
|
{ return this->r_type_; } |
|
|
|
// Return the destination address of the relocation. LSB stores the THUMB |
|
// bit. |
|
Arm_address |
|
destination() const |
|
{ return this->destination_; } |
|
|
|
private: |
|
// Associated relocation stub if there is one, or NULL. |
|
const Reloc_stub* reloc_stub_; |
|
// Relocation type. |
|
unsigned int r_type_; |
|
// Destination address of this relocation. LSB is used to distinguish |
|
// ARM/THUMB mode. |
|
Arm_address destination_; |
|
}; |
|
|
|
// Arm_output_data_got class. We derive this from Output_data_got to add |
|
// extra methods to handle TLS relocations in a static link. |
|
|
|
template<bool big_endian> |
|
class Arm_output_data_got : public Output_data_got<32, big_endian> |
|
{ |
|
public: |
|
Arm_output_data_got(Symbol_table* symtab, Layout* layout) |
|
: Output_data_got<32, big_endian>(), symbol_table_(symtab), layout_(layout) |
|
{ } |
|
|
|
// Add a static entry for the GOT entry at OFFSET. GSYM is a global |
|
// symbol and R_TYPE is the code of a dynamic relocation that needs to be |
|
// applied in a static link. |
|
void |
|
add_static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym) |
|
{ this->static_relocs_.push_back(Static_reloc(got_offset, r_type, gsym)); } |
|
|
|
// Add a static reloc for the GOT entry at OFFSET. RELOBJ is an object |
|
// defining a local symbol with INDEX. R_TYPE is the code of a dynamic |
|
// relocation that needs to be applied in a static link. |
|
void |
|
add_static_reloc(unsigned int got_offset, unsigned int r_type, |
|
Sized_relobj_file<32, big_endian>* relobj, |
|
unsigned int index) |
|
{ |
|
this->static_relocs_.push_back(Static_reloc(got_offset, r_type, relobj, |
|
index)); |
|
} |
|
|
|
// Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries. |
|
// The first one is initialized to be 1, which is the module index for |
|
// the main executable and the second one 0. A reloc of the type |
|
// R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will |
|
// be applied by gold. GSYM is a global symbol. |
|
void |
|
add_tls_gd32_with_static_reloc(unsigned int got_type, Symbol* gsym); |
|
|
|
// Same as the above but for a local symbol in OBJECT with INDEX. |
|
void |
|
add_tls_gd32_with_static_reloc(unsigned int got_type, |
|
Sized_relobj_file<32, big_endian>* object, |
|
unsigned int index); |
|
|
|
protected: |
|
// Write out the GOT table. |
|
void |
|
do_write(Output_file*); |
|
|
|
private: |
|
// This class represent dynamic relocations that need to be applied by |
|
// gold because we are using TLS relocations in a static link. |
|
class Static_reloc |
|
{ |
|
public: |
|
Static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym) |
|
: got_offset_(got_offset), r_type_(r_type), symbol_is_global_(true) |
|
{ this->u_.global.symbol = gsym; } |
|
|
|
Static_reloc(unsigned int got_offset, unsigned int r_type, |
|
Sized_relobj_file<32, big_endian>* relobj, unsigned int index) |
|
: got_offset_(got_offset), r_type_(r_type), symbol_is_global_(false) |
|
{ |
|
this->u_.local.relobj = relobj; |
|
this->u_.local.index = index; |
|
} |
|
|
|
// Return the GOT offset. |
|
unsigned int |
|
got_offset() const |
|
{ return this->got_offset_; } |
|
|
|
// Relocation type. |
|
unsigned int |
|
r_type() const |
|
{ return this->r_type_; } |
|
|
|
// Whether the symbol is global or not. |
|
bool |
|
symbol_is_global() const |
|
{ return this->symbol_is_global_; } |
|
|
|
// For a relocation against a global symbol, the global symbol. |
|
Symbol* |
|
symbol() const |
|
{ |
|
gold_assert(this->symbol_is_global_); |
|
return this->u_.global.symbol; |
|
} |
|
|
|
// For a relocation against a local symbol, the defining object. |
|
Sized_relobj_file<32, big_endian>* |
|
relobj() const |
|
{ |
|
gold_assert(!this->symbol_is_global_); |
|
return this->u_.local.relobj; |
|
} |
|
|
|
// For a relocation against a local symbol, the local symbol index. |
|
unsigned int |
|
index() const |
|
{ |
|
gold_assert(!this->symbol_is_global_); |
|
return this->u_.local.index; |
|
} |
|
|
|
private: |
|
// GOT offset of the entry to which this relocation is applied. |
|
unsigned int got_offset_; |
|
// Type of relocation. |
|
unsigned int r_type_; |
|
// Whether this relocation is against a global symbol. |
|
bool symbol_is_global_; |
|
// A global or local symbol. |
|
union |
|
{ |
|
struct |
|
{ |
|
// For a global symbol, the symbol itself. |
|
Symbol* symbol; |
|
} global; |
|
struct |
|
{ |
|
// For a local symbol, the object defining object. |
|
Sized_relobj_file<32, big_endian>* relobj; |
|
// For a local symbol, the symbol index. |
|
unsigned int index; |
|
} local; |
|
} u_; |
|
}; |
|
|
|
// Symbol table of the output object. |
|
Symbol_table* symbol_table_; |
|
// Layout of the output object. |
|
Layout* layout_; |
|
// Static relocs to be applied to the GOT. |
|
std::vector<Static_reloc> static_relocs_; |
|
}; |
|
|
|
// The ARM target has many relocation types with odd-sizes or noncontiguous |
|
// bits. The default handling of relocatable relocation cannot process these |
|
// relocations. So we have to extend the default code. |
|
|
|
template<bool big_endian, int sh_type, typename Classify_reloc> |
|
class Arm_scan_relocatable_relocs : |
|
public Default_scan_relocatable_relocs<sh_type, Classify_reloc> |
|
{ |
|
public: |
|
// Return the strategy to use for a local symbol which is a section |
|
// symbol, given the relocation type. |
|
inline Relocatable_relocs::Reloc_strategy |
|
local_section_strategy(unsigned int r_type, Relobj*) |
|
{ |
|
if (sh_type == elfcpp::SHT_RELA) |
|
return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA; |
|
else |
|
{ |
|
if (r_type == elfcpp::R_ARM_TARGET1 |
|
|| r_type == elfcpp::R_ARM_TARGET2) |
|
{ |
|
const Target_arm<big_endian>* arm_target = |
|
Target_arm<big_endian>::default_target(); |
|
r_type = arm_target->get_real_reloc_type(r_type); |
|
} |
|
|
|
switch(r_type) |
|
{ |
|
// Relocations that write nothing. These exclude R_ARM_TARGET1 |
|
// and R_ARM_TARGET2. |
|
case elfcpp::R_ARM_NONE: |
|
case elfcpp::R_ARM_V4BX: |
|
case elfcpp::R_ARM_TLS_GOTDESC: |
|
case elfcpp::R_ARM_TLS_CALL: |
|
case elfcpp::R_ARM_TLS_DESCSEQ: |
|
case elfcpp::R_ARM_THM_TLS_CALL: |
|
case elfcpp::R_ARM_GOTRELAX: |
|
case elfcpp::R_ARM_GNU_VTENTRY: |
|
case elfcpp::R_ARM_GNU_VTINHERIT: |
|
case elfcpp::R_ARM_THM_TLS_DESCSEQ16: |
|
case elfcpp::R_ARM_THM_TLS_DESCSEQ32: |
|
return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0; |
|
// These should have been converted to something else above. |
|
case elfcpp::R_ARM_TARGET1: |
|
case elfcpp::R_ARM_TARGET2: |
|
gold_unreachable(); |
|
// Relocations that write full 32 bits and |
|
// have alignment of 1. |
|
case elfcpp::R_ARM_ABS32: |
|
case elfcpp::R_ARM_REL32: |
|
case elfcpp::R_ARM_SBREL32: |
|
case elfcpp::R_ARM_GOTOFF32: |
|
case elfcpp::R_ARM_BASE_PREL: |
|
case elfcpp::R_ARM_GOT_BREL: |
|
case elfcpp::R_ARM_BASE_ABS: |
|
case elfcpp::R_ARM_ABS32_NOI: |
|
case elfcpp::R_ARM_REL32_NOI: |
|
case elfcpp::R_ARM_PLT32_ABS: |
|
case elfcpp::R_ARM_GOT_ABS: |
|
case elfcpp::R_ARM_GOT_PREL: |
|
case elfcpp::R_ARM_TLS_GD32: |
|
case elfcpp::R_ARM_TLS_LDM32: |
|
case elfcpp::R_ARM_TLS_LDO32: |
|
case elfcpp::R_ARM_TLS_IE32: |
|
case elfcpp::R_ARM_TLS_LE32: |
|
return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4_UNALIGNED; |
|
default: |
|
// For all other static relocations, return RELOC_SPECIAL. |
|
return Relocatable_relocs::RELOC_SPECIAL; |
|
} |
|
} |
|
} |
|
}; |
|
|
|
template<bool big_endian> |
|
class Target_arm : public Sized_target<32, big_endian> |
|
{ |
|
public: |
|
typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian> |
|
Reloc_section; |
|
|
|
// When were are relocating a stub, we pass this as the relocation number. |
|
static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1); |
|
|
|
Target_arm(const Target::Target_info* info = &arm_info) |
|
: Sized_target<32, big_endian>(info), |
|
got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL), |
|
rel_dyn_(NULL), rel_irelative_(NULL), copy_relocs_(elfcpp::R_ARM_COPY), |
|
got_mod_index_offset_(-1U), tls_base_symbol_defined_(false), |
|
stub_tables_(), stub_factory_(Stub_factory::get_instance()), |
|
should_force_pic_veneer_(false), |
|
arm_input_section_map_(), attributes_section_data_(NULL), |
|
fix_cortex_a8_(false), cortex_a8_relocs_info_() |
|
{ } |
|
|
|
// Whether we force PCI branch veneers. |
|
bool |
|
should_force_pic_veneer() const |
|
{ return this->should_force_pic_veneer_; } |
|
|
|
// Set PIC veneer flag. |
|
void |
|
set_should_force_pic_veneer(bool value) |
|
{ this->should_force_pic_veneer_ = value; } |
|
|
|
// Whether we use THUMB-2 instructions. |
|
bool |
|
using_thumb2() const |
|
{ |
|
Object_attribute* attr = |
|
this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch); |
|
int arch = attr->int_value(); |
|
return arch == elfcpp::TAG_CPU_ARCH_V6T2 || arch >= elfcpp::TAG_CPU_ARCH_V7; |
|
} |
|
|
|
// Whether we use THUMB/THUMB-2 instructions only. |
|
bool |
|
using_thumb_only() const |
|
{ |
|
Object_attribute* attr = |
|
this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch); |
|
|
|
if (attr->int_value() == elfcpp::TAG_CPU_ARCH_V6_M |
|
|| attr->int_value() == elfcpp::TAG_CPU_ARCH_V6S_M) |
|
return true; |
|
if (attr->int_value() != elfcpp::TAG_CPU_ARCH_V7 |
|
&& attr->int_value() != elfcpp::TAG_CPU_ARCH_V7E_M) |
|
return false; |
|
attr = this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile); |
|
return attr->int_value() == 'M'; |
|
} |
|
|
|
// Whether we have an NOP instruction. If not, use mov r0, r0 instead. |
|
bool |
|
may_use_arm_nop() const |
|
{ |
|
Object_attribute* attr = |
|
this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch); |
|
int arch = attr->int_value(); |
|
return (arch == elfcpp::TAG_CPU_ARCH_V6T2 |
|
|| arch == elfcpp::TAG_CPU_ARCH_V6K |
|
|| arch == elfcpp::TAG_CPU_ARCH_V7 |
|
|| arch == elfcpp::TAG_CPU_ARCH_V7E_M); |
|
} |
|
|
|
// Whether we have THUMB-2 NOP.W instruction. |
|
bool |
|
may_use_thumb2_nop() const |
|
{ |
|
Object_attribute* attr = |
|
this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch); |
|
int arch = attr->int_value(); |
|
return (arch == elfcpp::TAG_CPU_ARCH_V6T2 |
|
|| arch == elfcpp::TAG_CPU_ARCH_V7 |
|
|| arch == elfcpp::TAG_CPU_ARCH_V7E_M); |
|
} |
|
|
|
// Whether we have v4T interworking instructions available. |
|
bool |
|
may_use_v4t_interworking() const |
|
{ |
|
Object_attribute* attr = |
|
this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch); |
|
int arch = attr->int_value(); |
|
return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4 |
|
&& arch != elfcpp::TAG_CPU_ARCH_V4); |
|
} |
|
|
|
// Whether we have v5T interworking instructions available. |
|
bool |
|
may_use_v5t_interworking() const |
|
{ |
|
Object_attribute* attr = |
|
this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch); |
|
int arch = attr->int_value(); |
|
if (parameters->options().fix_arm1176()) |
|
return (arch == elfcpp::TAG_CPU_ARCH_V6T2 |
|
|| arch == elfcpp::TAG_CPU_ARCH_V7 |
|
|| arch == elfcpp::TAG_CPU_ARCH_V6_M |
|
|| arch == elfcpp::TAG_CPU_ARCH_V6S_M |
|
|| arch == elfcpp::TAG_CPU_ARCH_V7E_M); |
|
else |
|
return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4 |
|
&& arch != elfcpp::TAG_CPU_ARCH_V4 |
|
&& arch != elfcpp::TAG_CPU_ARCH_V4T); |
|
} |
|
|
|
// Process the relocations to determine unreferenced sections for |
|
// garbage collection. |
|
void |
|
gc_process_relocs(Symbol_table* symtab, |
|
Layout* layout, |
|
Sized_relobj_file<32, big_endian>* object, |
|
unsigned int data_shndx, |
|
unsigned int sh_type, |
|
const unsigned char* prelocs, |
|
size_t reloc_count, |
|
Output_section* output_section, |
|
bool needs_special_offset_handling, |
|
size_t local_symbol_count, |
|
const unsigned char* plocal_symbols); |
|
|
|
// Scan the relocations to look for symbol adjustments. |
|
void |
|
scan_relocs(Symbol_table* symtab, |
|
Layout* layout, |
|
Sized_relobj_file<32, big_endian>* object, |
|
unsigned int data_shndx, |
|
unsigned int sh_type, |
|
const unsigned char* prelocs, |
|
size_t reloc_count, |
|
Output_section* output_section, |
|
bool needs_special_offset_handling, |
|
size_t local_symbol_count, |
|
const unsigned char* plocal_symbols); |
|
|
|
// Finalize the sections. |
|
void |
|
do_finalize_sections(Layout*, const Input_objects*, Symbol_table*); |
|
|
|
// Return the value to use for a dynamic symbol which requires special |
|
// treatment. |
|
uint64_t |
|
do_dynsym_value(const Symbol*) const; |
|
|
|
// Return the plt address for globals. Since we have irelative plt entries, |
|
// address calculation is not as straightforward as plt_address + plt_offset. |
|
uint64_t |
|
do_plt_address_for_global(const Symbol* gsym) const |
|
{ return this->plt_section()->address_for_global(gsym); } |
|
|
|
// Return the plt address for locals. Since we have irelative plt entries, |
|
// address calculation is not as straightforward as plt_address + plt_offset. |
|
uint64_t |
|
do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const |
|
{ return this->plt_section()->address_for_local(relobj, symndx); } |
|
|
|
// Relocate a section. |
|
void |
|
relocate_section(const Relocate_info<32, big_endian>*, |
|
unsigned int sh_type, |
|
const unsigned char* prelocs, |
|
size_t reloc_count, |
|
Output_section* output_section, |
|
bool needs_special_offset_handling, |
|
unsigned char* view, |
|
Arm_address view_address, |
|
section_size_type view_size, |
|
const Reloc_symbol_changes*); |
|
|
|
// Scan the relocs during a relocatable link. |
|
void |
|
scan_relocatable_relocs(Symbol_table* symtab, |
|
Layout* layout, |
|
Sized_relobj_file<32, big_endian>* object, |
|
unsigned int data_shndx, |
|
unsigned int sh_type, |
|
const unsigned char* prelocs, |
|
size_t reloc_count, |
|
Output_section* output_section, |
|
bool needs_special_offset_handling, |
|
size_t local_symbol_count, |
|
const unsigned char* plocal_symbols, |
|
Relocatable_relocs*); |
|
|
|
// Emit relocations for a section. |
|
void |
|
relocate_relocs(const Relocate_info<32, big_endian>*, |
|
unsigned int sh_type, |
|
const unsigned char* prelocs, |
|
size_t reloc_count, |
|
Output_section* output_section, |
|
typename elfcpp::Elf_types<32>::Elf_Off |
|
offset_in_output_section, |
|
const Relocatable_relocs*, |
|
unsigned char* view, |
|
Arm_address view_address, |
|
section_size_type view_size, |
|
unsigned char* reloc_view, |
|
section_size_type reloc_view_size); |
|
|
|
// Perform target-specific processing in a relocatable link. This is |
|
// only used if we use the relocation strategy RELOC_SPECIAL. |
|
void |
|
relocate_special_relocatable(const Relocate_info<32, big_endian>* relinfo, |
|
unsigned int sh_type, |
|
const unsigned char* preloc_in, |
|
size_t relnum, |
|
Output_section* output_section, |
|
typename elfcpp::Elf_types<32>::Elf_Off |
|
offset_in_output_section, |
|
unsigned char* view, |
|
typename elfcpp::Elf_types<32>::Elf_Addr |
|
view_address, |
|
section_size_type view_size, |
|
unsigned char* preloc_out); |
|
|
|
// Return whether SYM is defined by the ABI. |
|
bool |
|
do_is_defined_by_abi(const Symbol* sym) const |
|
{ return strcmp(sym->name(), "__tls_get_addr") == 0; } |
|
|
|
// Return whether there is a GOT section. |
|
bool |
|
has_got_section() const |
|
{ return this->got_ != NULL; } |
|
|
|
// Return the size of the GOT section. |
|
section_size_type |
|
got_size() const |
|
{ |
|
gold_assert(this->got_ != NULL); |
|
return this->got_->data_size(); |
|
} |
|
|
|
// Return the number of entries in the GOT. |
|
unsigned int |
|
got_entry_count() const |
|
{ |
|
if (!this->has_got_section()) |
|
return 0; |
|
return this->got_size() / 4; |
|
} |
|
|
|
// Return the number of entries in the PLT. |
|
unsigned int |
|
plt_entry_count() const; |
|
|
|
// Return the offset of the first non-reserved PLT entry. |
|
unsigned int |
|
first_plt_entry_offset() const; |
|
|
|
// Return the size of each PLT entry. |
|
unsigned int |
|
plt_entry_size() const; |
|
|
|
// Get the section to use for IRELATIVE relocations, create it if necessary. |
|
Reloc_section* |
|
rel_irelative_section(Layout*); |
|
|
|
// Map platform-specific reloc types |
|
static unsigned int |
|
get_real_reloc_type(unsigned int r_type); |
|
|
|
// |
|
// Methods to support stub-generations. |
|
// |
|
|
|
// Return the stub factory |
|
const Stub_factory& |
|
stub_factory() const |
|
{ return this->stub_factory_; } |
|
|
|
// Make a new Arm_input_section object. |
|
Arm_input_section<big_endian>* |
|
new_arm_input_section(Relobj*, unsigned int); |
|
|
|
// Find the Arm_input_section object corresponding to the SHNDX-th input |
|
// section of RELOBJ. |
|
Arm_input_section<big_endian>* |
|
find_arm_input_section(Relobj* relobj, unsigned int shndx) const; |
|
|
|
// Make a new Stub_table |
|
Stub_table<big_endian>* |
|
new_stub_table(Arm_input_section<big_endian>*); |
|
|
|
// Scan a section for stub generation. |
|
void |
|
scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int, |
|
const unsigned char*, size_t, Output_section*, |
|
bool, const unsigned char*, Arm_address, |
|
section_size_type); |
|
|
|
// Relocate a stub. |
|
void |
|
relocate_stub(Stub*, const Relocate_info<32, big_endian>*, |
|
Output_section*, unsigned char*, Arm_address, |
|
section_size_type); |
|
|
|
// Get the default ARM target. |
|
static Target_arm<big_endian>* |
|
default_target() |
|
{ |
|
gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM |
|
&& parameters->target().is_big_endian() == big_endian); |
|
return static_cast<Target_arm<big_endian>*>( |
|
parameters->sized_target<32, big_endian>()); |
|
} |
|
|
|
// Whether NAME belongs to a mapping symbol. |
|
static bool |
|
is_mapping_symbol_name(const char* name) |
|
{ |
|
return (name |
|
&& name[0] == '$' |
|
&& (name[1] == 'a' || name[1] == 't' || name[1] == 'd') |
|
&& (name[2] == '\0' || name[2] == '.')); |
|
} |
|
|
|
// Whether we work around the Cortex-A8 erratum. |
|
bool |
|
fix_cortex_a8() const |
|
{ return this->fix_cortex_a8_; } |
|
|
|
// Whether we merge exidx entries in debuginfo. |
|
bool |
|
merge_exidx_entries() const |
|
{ return parameters->options().merge_exidx_entries(); } |
|
|
|
// Whether we fix R_ARM_V4BX relocation. |
|
// 0 - do not fix |
|
// 1 - replace with MOV instruction (armv4 target) |
|
// 2 - make interworking veneer (>= armv4t targets only) |
|
General_options::Fix_v4bx |
|
fix_v4bx() const |
|
{ return parameters->options().fix_v4bx(); } |
|
|
|
// Scan a span of THUMB code section for Cortex-A8 erratum. |
|
void |
|
scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int, |
|
section_size_type, section_size_type, |
|
const unsigned char*, Arm_address); |
|
|
|
// Apply Cortex-A8 workaround to a branch. |
|
void |
|
apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address, |
|
unsigned char*, Arm_address); |
|
|
|
protected: |
|
// Make the PLT-generator object. |
|
Output_data_plt_arm<big_endian>* |
|
make_data_plt(Layout* layout, |
|
Arm_output_data_got<big_endian>* got, |
|
Output_data_space* got_plt, |
|
Output_data_space* got_irelative) |
|
{ return this->do_make_data_plt(layout, got, got_plt, got_irelative); } |
|
|
|
// Make an ELF object. |
|
Object* |
|
do_make_elf_object(const std::string&, Input_file*, off_t, |
|
const elfcpp::Ehdr<32, big_endian>& ehdr); |
|
|
|
Object* |
|
do_make_elf_object(const std::string&, Input_file*, off_t, |
|
const elfcpp::Ehdr<32, !big_endian>&) |
|
{ gold_unreachable(); } |
|
|
|
Object* |
|
do_make_elf_object(const std::string&, Input_file*, off_t, |
|
const elfcpp::Ehdr<64, false>&) |
|
{ gold_unreachable(); } |
|
|
|
Object* |
|
do_make_elf_object(const std::string&, Input_file*, off_t, |
|
const elfcpp::Ehdr<64, true>&) |
|
{ gold_unreachable(); } |
|
|
|
// Make an output section. |
|
Output_section* |
|
do_make_output_section(const char* name, elfcpp::Elf_Word type, |
|
elfcpp::Elf_Xword flags) |
|
{ return new Arm_output_section<big_endian>(name, type, flags); } |
|
|
|
void |
|
do_adjust_elf_header(unsigned char* view, int len); |
|
|
|
// We only need to generate stubs, and hence perform relaxation if we are |
|
// not doing relocatable linking. |
|
bool |
|
do_may_relax() const |
|
{ return !parameters->options().relocatable(); } |
|
|
|
bool |
|
do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*); |
|
|
|
// Determine whether an object attribute tag takes an integer, a |
|
// string or both. |
|
int |
|
do_attribute_arg_type(int tag) const; |
|
|
|
// Reorder tags during output. |
|
int |
|
do_attributes_order(int num) const; |
|
|
|
// This is called when the target is selected as the default. |
|
void |
|
do_select_as_default_target() |
|
{ |
|
// No locking is required since there should only be one default target. |
|
// We cannot have both the big-endian and little-endian ARM targets |
|
// as the default. |
|
gold_assert(arm_reloc_property_table == NULL); |
|
arm_reloc_property_table = new Arm_reloc_property_table(); |
|
} |
|
|
|
// Virtual function which is set to return true by a target if |
|
// it can use relocation types to determine if a function's |
|
// pointer is taken. |
|
virtual bool |
|
do_can_check_for_function_pointers() const |
|
{ return true; } |
|
|
|
// Whether a section called SECTION_NAME may have function pointers to |
|
// sections not eligible for safe ICF folding. |
|
virtual bool |
|
do_section_may_have_icf_unsafe_pointers(const char* section_name) const |
|
{ |
|
return (!is_prefix_of(".ARM.exidx", section_name) |
|
&& !is_prefix_of(".ARM.extab", section_name) |
|
&& Target::do_section_may_have_icf_unsafe_pointers(section_name)); |
|
} |
|
|
|
virtual void |
|
do_define_standard_symbols(Symbol_table*, Layout*); |
|
|
|
virtual Output_data_plt_arm<big_endian>* |
|
do_make_data_plt(Layout* layout, |
|
Arm_output_data_got<big_endian>* got, |
|
Output_data_space* got_plt, |
|
Output_data_space* got_irelative) |
|
{ |
|
gold_assert(got_plt != NULL && got_irelative != NULL); |
|
if (parameters->options().long_plt()) |
|
return new Output_data_plt_arm_long<big_endian>( |
|
layout, got, got_plt, got_irelative); |
|
else |
|
return new Output_data_plt_arm_short<big_endian>( |
|
layout, got, got_plt, got_irelative); |
|
} |
|
|
|
private: |
|
// The class which scans relocations. |
|
class Scan |
|
{ |
|
public: |
|
Scan() |
|
: issued_non_pic_error_(false) |
|
{ } |
|
|
|
static inline int |
|
get_reference_flags(unsigned int r_type); |
|
|
|
inline void |
|
local(Symbol_table* symtab, Layout* layout, Target_arm* target, |
|
Sized_relobj_file<32, big_endian>* object, |
|
unsigned int data_shndx, |
|
Output_section* output_section, |
|
const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type, |
|
const elfcpp::Sym<32, big_endian>& lsym, |
|
bool is_discarded); |
|
|
|
inline void |
|
global(Symbol_table* symtab, Layout* layout, Target_arm* target, |
|
Sized_relobj_file<32, big_endian>* object, |
|
unsigned int data_shndx, |
|
Output_section* output_section, |
|
const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type, |
|
Symbol* gsym); |
|
|
|
inline bool |
|
local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* , |
|
Sized_relobj_file<32, big_endian>* , |
|
unsigned int , |
|
Output_section* , |
|
const elfcpp::Rel<32, big_endian>& , |
|
unsigned int , |
|
const elfcpp::Sym<32, big_endian>&); |
|
|
|
inline bool |
|
global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* , |
|
Sized_relobj_file<32, big_endian>* , |
|
unsigned int , |
|
Output_section* , |
|
const elfcpp::Rel<32, big_endian>& , |
|
unsigned int , Symbol*); |
|
|
|
private: |
|
static void |
|
unsupported_reloc_local(Sized_relobj_file<32, big_endian>*, |
|
unsigned int r_type); |
|
|
|
static void |
|
unsupported_reloc_global(Sized_relobj_file<32, big_endian>*, |
|
unsigned int r_type, Symbol*); |
|
|
|
void |
|
check_non_pic(Relobj*, unsigned int r_type); |
|
|
|
// Almost identical to Symbol::needs_plt_entry except that it also |
|
// handles STT_ARM_TFUNC. |
|
static bool |
|
symbol_needs_plt_entry(const Symbol* sym) |
|
{ |
|
// An undefined symbol from an executable does not need a PLT entry. |
|
if (sym->is_undefined() && !parameters->options().shared()) |
|
return false; |
|
|
|
if (sym->type() == elfcpp::STT_GNU_IFUNC) |
|
return true; |
|
|
|
return (!parameters->doing_static_link() |
|
&& (sym->type() == elfcpp::STT_FUNC |
|
|| sym->type() == elfcpp::STT_ARM_TFUNC) |
|
&& (sym->is_from_dynobj() |
|
|| sym->is_undefined() |
|
|| sym->is_preemptible())); |
|
} |
|
|
|
inline bool |
|
possible_function_pointer_reloc(unsigned int r_type); |
|
|
|
// Whether a plt entry is needed for ifunc. |
|
bool |
|
reloc_needs_plt_for_ifunc(Sized_relobj_file<32, big_endian>*, |
|
unsigned int r_type); |
|
|
|
// Whether we have issued an error about a non-PIC compilation. |
|
bool issued_non_pic_error_; |
|
}; |
|
|
|
// The class which implements relocation. |
|
class Relocate |
|
{ |
|
public: |
|
Relocate() |
|
{ } |
|
|
|
~Relocate() |
|
{ } |
|
|
|
// Return whether the static relocation needs to be applied. |
|
inline bool |
|
should_apply_static_reloc(const Sized_symbol<32>* gsym, |
|
unsigned int r_type, |
|
bool is_32bit, |
|
Output_section* output_section); |
|
|
|
// Do a relocation. Return false if the caller should not issue |
|
// any warnings about this relocation. |
|
inline bool |
|
relocate(const Relocate_info<32, big_endian>*, Target_arm*, |
|
Output_section*, size_t relnum, |
|
const elfcpp::Rel<32, big_endian>&, |
|
unsigned int r_type, const Sized_symbol<32>*, |
|
const Symbol_value<32>*, |
|
unsigned char*, Arm_address, |
|
section_size_type); |
|
|
|
// Return whether we want to pass flag NON_PIC_REF for this |
|
// reloc. This means the relocation type accesses a symbol not via |
|
// GOT or PLT. |
|
static inline bool |
|
reloc_is_non_pic(unsigned int r_type) |
|
{ |
|
switch (r_type) |
|
{ |
|
// These relocation types reference GOT or PLT entries explicitly. |
|
case elfcpp::R_ARM_GOT_BREL: |
|
case elfcpp::R_ARM_GOT_ABS: |
|
case elfcpp::R_ARM_GOT_PREL: |
|
case elfcpp::R_ARM_GOT_BREL12: |
|
case elfcpp::R_ARM_PLT32_ABS: |
|
case elfcpp::R_ARM_TLS_GD32: |
|
case elfcpp::R_ARM_TLS_LDM32: |
|
case elfcpp::R_ARM_TLS_IE32: |
|
case elfcpp::R_ARM_TLS_IE12GP: |
|
|
|
// These relocate types may use PLT entries. |
|
case elfcpp::R_ARM_CALL: |
|
case elfcpp::R_ARM_THM_CALL: |
|
case elfcpp::R_ARM_JUMP24: |
|
case elfcpp::R_ARM_THM_JUMP24: |
|
case elfcpp::R_ARM_THM_JUMP19: |
|
case elfcpp::R_ARM_PLT32: |
|
case elfcpp::R_ARM_THM_XPC22: |
|
case elfcpp::R_ARM_PREL31: |
|
case elfcpp::R_ARM_SBREL31: |
|
return false; |
|
|
|
default: |
|
return true; |
|
} |
|
} |
|
|
|
private: |
|
// Do a TLS relocation. |
|
inline typename Arm_relocate_functions<big_endian>::Status |
|
relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*, |
|
size_t, const elfcpp::Rel<32, big_endian>&, unsigned int, |
|
const Sized_symbol<32>*, const Symbol_value<32>*, |
|
unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, |
|
section_size_type); |
|
|
|
}; |
|
|
|
// A class which returns the size required for a relocation type, |
|
// used while scanning relocs during a relocatable link. |
|
class Relocatable_size_for_reloc |
|
{ |
|
public: |
|
unsigned int |
|
get_size_for_reloc(unsigned int, Relobj*); |
|
}; |
|
|
|
// Adjust TLS relocation type based on the options and whether this |
|
// is a local symbol. |
|
static tls::Tls_optimization |
|
optimize_tls_reloc(bool is_final, int r_type); |
|
|
|
// Get the GOT section, creating it if necessary. |
|
Arm_output_data_got<big_endian>* |
|
got_section(Symbol_table*, Layout*); |
|
|
|
// Get the GOT PLT section. |
|
Output_data_space* |
|
got_plt_section() const |
|
{ |
|
gold_assert(this->got_plt_ != NULL); |
|
return this->got_plt_; |
|
} |
|
|
|
// Create the PLT section. |
|
void |
|
make_plt_section(Symbol_table* symtab, Layout* layout); |
|
|
|
// Create a PLT entry for a global symbol. |
|
void |
|
make_plt_entry(Symbol_table*, Layout*, Symbol*); |
|
|
|
// Create a PLT entry for a local STT_GNU_IFUNC symbol. |
|
void |
|
make_local_ifunc_plt_entry(Symbol_table*, Layout*, |
|
Sized_relobj_file<32, big_endian>* relobj, |
|
unsigned int local_sym_index); |
|
|
|
// Define the _TLS_MODULE_BASE_ symbol in the TLS segment. |
|
void |
|
define_tls_base_symbol(Symbol_table*, Layout*); |
|
|
|
// Create a GOT entry for the TLS module index. |
|
unsigned int |
|
got_mod_index_entry(Symbol_table* symtab, Layout* layout, |
|
Sized_relobj_file<32, big_endian>* object); |
|
|
|
// Get the PLT section. |
|
const Output_data_plt_arm<big_endian>* |
|
plt_section() const |
|
{ |
|
gold_assert(this->plt_ != NULL); |
|
return this->plt_; |
|
} |
|
|
|
// Get the dynamic reloc section, creating it if necessary. |
|
Reloc_section* |
|
rel_dyn_section(Layout*); |
|
|
|
// Get the section to use for TLS_DESC relocations. |
|
Reloc_section* |
|
rel_tls_desc_section(Layout*) const; |
|
|
|
// Return true if the symbol may need a COPY relocation. |
|
// References from an executable object to non-function symbols |
|
// defined in a dynamic object may need a COPY relocation. |
|
bool |
|
may_need_copy_reloc(Symbol* gsym) |
|
{ |
|
return (gsym->type() != elfcpp::STT_ARM_TFUNC |
|
&& gsym->may_need_copy_reloc()); |
|
} |
|
|
|
// Add a potential copy relocation. |
|
void |
|
copy_reloc(Symbol_table* symtab, Layout* layout, |
|
Sized_relobj_file<32, big_endian>* object, |
|
unsigned int shndx, Output_section* output_section, |
|
Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc) |
|
{ |
|
this->copy_relocs_.copy_reloc(symtab, layout, |
|
symtab->get_sized_symbol<32>(sym), |
|
object, shndx, output_section, reloc, |
|
this->rel_dyn_section(layout)); |
|
} |
|
|
|
// Whether two EABI versions are compatible. |
|
static bool |
|
are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2); |
|
|
|
// Merge processor-specific flags from input object and those in the ELF |
|
// header of the output. |
|
void |
|
merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word); |
|
|
|
// Get the secondary compatible architecture. |
|
static int |
|
get_secondary_compatible_arch(const Attributes_section_data*); |
|
|
|
// Set the secondary compatible architecture. |
|
static void |
|
set_secondary_compatible_arch(Attributes_section_data*, int); |
|
|
|
static int |
|
tag_cpu_arch_combine(const char*, int, int*, int, int); |
|
|
|
// Helper to print AEABI enum tag value. |
|
static std::string |
|
aeabi_enum_name(unsigned int); |
|
|
|
// Return string value for TAG_CPU_name. |
|
static std::string |
|
tag_cpu_name_value(unsigned int); |
|
|
|
// Query attributes object to see if integer divide instructions may be |
|
// present in an object. |
|
static bool |
|
attributes_accept_div(int arch, int profile, |
|
const Object_attribute* div_attr); |
|
|
|
// Query attributes object to see if integer divide instructions are |
|
// forbidden to be in the object. This is not the inverse of |
|
// attributes_accept_div. |
|
static bool |
|
attributes_forbid_div(const Object_attribute* div_attr); |
|
|
|
// Merge object attributes from input object and those in the output. |
|
void |
|
merge_object_attributes(const char*, const Attributes_section_data*); |
|
|
|
// Helper to get an AEABI object attribute |
|
Object_attribute* |
|
get_aeabi_object_attribute(int tag) const |
|
{ |
|
Attributes_section_data* pasd = this->attributes_section_data_; |
|
gold_assert(pasd != NULL); |
|
Object_attribute* attr = |
|
pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag); |
|
gold_assert(attr != NULL); |
|
return attr; |
|
} |
|
|
|
// |
|
// Methods to support stub-generations. |
|
// |
|
|
|
// Group input sections for stub generation. |
|
void |
|
group_sections(Layout*, section_size_type, bool, const Task*); |
|
|
|
// Scan a relocation for stub generation. |
|
void |
|
scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int, |
|
const Sized_symbol<32>*, unsigned int, |
|
const Symbol_value<32>*, |
|
elfcpp::Elf_types<32>::Elf_Swxword, Arm_address); |
|
|
|
// Scan a relocation section for stub. |
|
template<int sh_type> |
|
void |
|
scan_reloc_section_for_stubs( |
|
const Relocate_info<32, big_endian>* relinfo, |
|
const unsigned char* prelocs, |
|
size_t reloc_count, |
|
Output_section* output_section, |
|
bool needs_special_offset_handling, |
|
const unsigned char* view, |
|
elfcpp::Elf_types<32>::Elf_Addr view_address, |
|
section_size_type); |
|
|
|
// Fix .ARM.exidx section coverage. |
|
void |
|
fix_exidx_coverage(Layout*, const Input_objects*, |
|
Arm_output_section<big_endian>*, Symbol_table*, |
|
const Task*); |
|
|
|
// Functors for STL set. |
|
struct output_section_address_less_than |
|
{ |
|
bool |
|
operator()(const Output_section* s1, const Output_section* s2) const |
|
{ return s1->address() < s2->address(); } |
|
}; |
|
|
|
// Information about this specific target which we pass to the |
|
// general Target structure. |
|
static const Target::Target_info arm_info; |
|
|
|
// The types of GOT entries needed for this platform. |
|
// These values are exposed to the ABI in an incremental link. |
|
// Do not renumber existing values without changing the version |
|
// number of the .gnu_incremental_inputs section. |
|
enum Got_type |
|
{ |
|
GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol |
|
GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset |
|
GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset |
|
GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair |
|
GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair |
|
}; |
|
|
|
typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list; |
|
|
|
// Map input section to Arm_input_section. |
|
typedef Unordered_map<Section_id, |
|
Arm_input_section<big_endian>*, |
|
Section_id_hash> |
|
Arm_input_section_map; |
|
|
|
// Map output addresses to relocs for Cortex-A8 erratum. |
|
typedef Unordered_map<Arm_address, const Cortex_a8_reloc*> |
|
Cortex_a8_relocs_info; |
|
|
|
// The GOT section. |
|
Arm_output_data_got<big_endian>* got_; |
|
// The PLT section. |
|
Output_data_plt_arm<big_endian>* plt_; |
|
// The GOT PLT section. |
|
Output_data_space* got_plt_; |
|
// The GOT section for IRELATIVE relocations. |
|
Output_data_space* got_irelative_; |
|
// The dynamic reloc section. |
|
Reloc_section* rel_dyn_; |
|
// The section to use for IRELATIVE relocs. |
|
Reloc_section* rel_irelative_; |
|
// Relocs saved to avoid a COPY reloc. |
|
Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_; |
|
// Offset of the GOT entry for the TLS module index. |
|
unsigned int got_mod_index_offset_; |
|
// True if the _TLS_MODULE_BASE_ symbol has been defined. |
|
bool tls_base_symbol_defined_; |
|
// Vector of Stub_tables created. |
|
Stub_table_list stub_tables_; |
|
// Stub factory. |
|
const Stub_factory &stub_factory_; |
|
// Whether we force PIC branch veneers. |
|
bool should_force_pic_veneer_; |
|
// Map for locating Arm_input_sections. |
|
Arm_input_section_map arm_input_section_map_; |
|
// Attributes section data in output. |
|
Attributes_section_data* attributes_section_data_; |
|
// Whether we want to fix code for Cortex-A8 erratum. |
|
bool fix_cortex_a8_; |
|
// Map addresses to relocs for Cortex-A8 erratum. |
|
Cortex_a8_relocs_info cortex_a8_relocs_info_; |
|
}; |
|
|
|
template<bool big_endian> |
|
const Target::Target_info Target_arm<big_endian>::arm_info = |
|
{ |
|
32, // size |
|
big_endian, // is_big_endian |
|
elfcpp::EM_ARM, // machine_code |
|
false, // has_make_symbol |
|
false, // has_resolve |
|
false, // has_code_fill |
|
true, // is_default_stack_executable |
|
false, // can_icf_inline_merge_sections |
|
'\0', // wrap_char |
|
"/usr/lib/libc.so.1", // dynamic_linker |
|
0x8000, // default_text_segment_address |
|
0x1000, // abi_pagesize (overridable by -z max-page-size) |
|
0x1000, // common_pagesize (overridable by -z common-page-size) |
|
false, // isolate_execinstr |
|
0, // rosegment_gap |
|
elfcpp::SHN_UNDEF, // small_common_shndx |
|
elfcpp::SHN_UNDEF, // large_common_shndx |
|
0, // small_common_section_flags |
|
0, // large_common_section_flags |
|
".ARM.attributes", // attributes_section |
|
"aeabi", // attributes_vendor |
|
"_start" // entry_symbol_name |
|
}; |
|
|
|
// Arm relocate functions class |
|
// |
|
|
|
template<bool big_endian> |
|
class Arm_relocate_functions : public Relocate_functions<32, big_endian> |
|
{ |
|
public: |
|
typedef enum |
|
{ |
|
STATUS_OKAY, // No error during relocation. |
|
STATUS_OVERFLOW, // Relocation overflow. |
|
STATUS_BAD_RELOC // Relocation cannot be applied. |
|
} Status; |
|
|
|
private: |
|
typedef Relocate_functions<32, big_endian> Base; |
|
typedef Arm_relocate_functions<big_endian> This; |
|
|
|
// Encoding of imm16 argument for movt and movw ARM instructions |
|
// from ARM ARM: |
|
// |
|
// imm16 := imm4 | imm12 |
|
// |
|
// f e d c b a 9 8 7 6 5 4 3 2 1 0 f e d c b a 9 8 7 6 5 4 3 2 1 0 |
|
// +-------+---------------+-------+-------+-----------------------+ |
|
// | | |imm4 | |imm12 | |
|
// +-------+---------------+-------+-------+-----------------------+ |
|
|
|
// Extract the relocation addend from VAL based on the ARM |
|
// instruction encoding described above. |
|
static inline typename elfcpp::Swap<32, big_endian>::Valtype |
|
extract_arm_movw_movt_addend( |
|
typename elfcpp::Swap<32, big_endian>::Valtype val) |
|
{ |
|
// According to the Elf ABI for ARM Architecture the immediate |
|
// field is sign-extended to form the addend. |
|
return Bits<16>::sign_extend32(((val >> 4) & 0xf000) | (val & 0xfff)); |
|
} |
|
|
|
// Insert X into VAL based on the ARM instruction encoding described |
|
// above. |
|
static inline typename elfcpp::Swap<32, big_endian>::Valtype |
|
insert_val_arm_movw_movt( |
|
typename elfcpp::Swap<32, big_endian>::Valtype val, |
|
typename elfcpp::Swap<32, big_endian>::Valtype x) |
|
{ |
|
val &= 0xfff0f000; |
|
val |= x & 0x0fff; |
|
val |= (x & 0xf000) << 4; |
|
return val; |
|
} |
|
|
|
// Encoding of imm16 argument for movt and movw Thumb2 instructions |
|
// from ARM ARM: |
|
// |
|
// imm16 := imm4 | i | imm3 | imm8 |
|
// |
|
// f e d c b a 9 8 7 6 5 4 3 2 1 0 f e d c b a 9 8 7 6 5 4 3 2 1 0 |
|
// +---------+-+-----------+-------++-+-----+-------+---------------+ |
|
// | |i| |imm4 || |imm3 | |imm8 | |
|
// +---------+-+-----------+-------++-+-----+-------+---------------+ |
|
|
|
// Extract the relocation addend from VAL based on the Thumb2 |
|
// instruction encoding described above. |
|
static inline typename elfcpp::Swap<32, big_endian>::Valtype |
|
extract_thumb_movw_movt_addend( |
|
typename elfcpp::Swap<32, big_endian>::Valtype val) |
|
{ |
|
// According to the Elf ABI for ARM Architecture the immediate |
|
// field is sign-extended to form the addend. |
|
return Bits<16>::sign_extend32(((val >> 4) & 0xf000) |
|
| ((val >> 15) & 0x0800) |
|
| ((val >> 4) & 0x0700) |
|
| (val & 0x00ff)); |
|
} |
|
|
|
// Insert X into VAL based on the Thumb2 instruction encoding |
|
// described above. |
|
static inline typename elfcpp::Swap<32, big_endian>::Valtype |
|
insert_val_thumb_movw_movt( |
|
typename elfcpp::Swap<32, big_endian>::Valtype val, |
|
typename elfcpp::Swap<32, big_endian>::Valtype x) |
|
{ |
|
val &= 0xfbf08f00; |
|
val |= (x & 0xf000) << 4; |
|
val |= (x & 0x0800) << 15; |
|
val |= (x & 0x0700) << 4; |
|
val |= (x & 0x00ff); |
|
return val; |
|
} |
|
|
|
// Calculate the smallest constant Kn for the specified residual. |
|
// (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32) |
|
static uint32_t |
|
calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual) |
|
{ |
|
int32_t msb; |
|
|
|
if (residual == 0) |
|
return 0; |
|
// Determine the most significant bit in the residual and |
|
// align the resulting value to a 2-bit boundary. |
|
for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2) |
|
; |
|
// The desired shift is now (msb - 6), or zero, whichever |
|
// is the greater. |
|
return (((msb - 6) < 0) ? 0 : (msb - 6)); |
|
} |
|
|
|
// Calculate the final residual for the specified group index. |
|
// If the passed group index is less than zero, the method will return |
|
// the value of the specified residual without any change. |
|
// (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32) |
|
static typename elfcpp::Swap<32, big_endian>::Valtype |
|
calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual, |
|
const int group) |
|
{ |
|
for (int n = 0; n <= group; n++) |
|
{ |
|
// Calculate which part of the value to mask. |
|
uint32_t shift = calc_grp_kn(residual); |
|
// Calculate the residual for the next time around. |
|
residual &= ~(residual & (0xff << shift)); |
|
} |
|
|
|
return residual; |
|
} |
|
|
|
// Calculate the value of Gn for the specified group index. |
|
// We return it in the form of an encoded constant-and-rotation. |
|
// (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32) |
|
static typename elfcpp::Swap<32, big_endian>::Valtype |
|
calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual, |
|
const int group) |
|
{ |
|
typename elfcpp::Swap<32, big_endian>::Valtype gn = 0; |
|
uint32_t shift = 0; |
|
|
|
for (int n = 0; n <= group; n++) |
|
{ |
|
// Calculate which part of the value to mask. |
|
shift = calc_grp_kn(residual); |
|
// Calculate Gn in 32-bit as well as encoded constant-and-rotation form. |
|
gn = residual & (0xff << shift); |
|
// Calculate the residual for the next time around. |
|
residual &= ~gn; |
|
} |
|
// Return Gn in the form of an encoded constant-and-rotation. |
|
return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8)); |
|
} |
|
|
|
public: |
|
// Handle ARM long branches. |
|
static typename This::Status |
|
arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*, |
|
unsigned char*, const Sized_symbol<32>*, |
|
const Arm_relobj<big_endian>*, unsigned int, |
|
const Symbol_value<32>*, Arm_address, Arm_address, bool); |
|
|
|
// Handle THUMB long branches. |
|
static typename This::Status |
|
thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*, |
|
unsigned char*, const Sized_symbol<32>*, |
|
const Arm_relobj<big_endian>*, unsigned int, |
|
const Symbol_value<32>*, Arm_address, Arm_address, bool); |
|
|
|
|
|
// Return the branch offset of a 32-bit THUMB branch. |
|
static inline int32_t |
|
thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn) |
|
{ |
|
// We use the Thumb-2 encoding (backwards compatible with Thumb-1) |
|
// involving the J1 and J2 bits. |
|
uint32_t s = (upper_insn & (1U << 10)) >> 10; |
|
uint32_t upper = upper_insn & 0x3ffU; |
|
uint32_t lower = lower_insn & 0x7ffU; |
|
uint32_t j1 = (lower_insn & (1U << 13)) >> 13; |
|
uint32_t j2 = (lower_insn & (1U << 11)) >> 11; |
|
uint32_t i1 = j1 ^ s ? 0 : 1; |
|
uint32_t i2 = j2 ^ s ? 0 : 1; |
|
|
|
return Bits<25>::sign_extend32((s << 24) | (i1 << 23) | (i2 << 22) |
|
| (upper << 12) | (lower << 1)); |
|
} |
|
|
|
// Insert OFFSET to a 32-bit THUMB branch and return the upper instruction. |
|
// UPPER_INSN is the original upper instruction of the branch. Caller is |
|
// responsible for overflow checking and BLX offset adjustment. |
|
static inline uint16_t |
|
thumb32_branch_upper(uint16_t upper_insn, int32_t offset) |
|
{ |
|
uint32_t s = offset < 0 ? 1 : 0; |
|
uint32_t bits = static_cast<uint32_t>(offset); |
|
return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10); |
|
} |
|
|
|
// Insert OFFSET to a 32-bit THUMB branch and return the lower instruction. |
|
// LOWER_INSN is the original lower instruction of the branch. Caller is |
|
// responsible for overflow checking and BLX offset adjustment. |
|
static inline uint16_t |
|
thumb32_branch_lower(uint16_t lower_insn, int32_t offset) |
|
{ |
|
uint32_t s = offset < 0 ? 1 : 0; |
|
uint32_t bits = static_cast<uint32_t>(offset); |
|
return ((lower_insn & ~0x2fffU) |
|
| ((((bits >> 23) & 1) ^ !s) << 13) |
|
| ((((bits >> 22) & 1) ^ !s) << 11) |
|
| ((bits >> 1) & 0x7ffU)); |
|
} |
|
|
|
// Return the branch offset of a 32-bit THUMB conditional branch. |
|
static inline int32_t |
|
thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn) |
|
{ |
|
uint32_t s = (upper_insn & 0x0400U) >> 10; |
|
uint32_t j1 = (lower_insn & 0x2000U) >> 13; |
|
uint32_t j2 = (lower_insn & 0x0800U) >> 11; |
|
uint32_t lower = (lower_insn & 0x07ffU); |
|
uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU); |
|
|
|
return Bits<21>::sign_extend32((upper << 12) | (lower << 1)); |
|
} |
|
|
|
// Insert OFFSET to a 32-bit THUMB conditional branch and return the upper |
|
// instruction. UPPER_INSN is the original upper instruction of the branch. |
|
// Caller is responsible for overflow checking. |
|
static inline uint16_t |
|
thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset) |
|
{ |
|
uint32_t s = offset < 0 ? 1 : 0; |
|
uint32_t bits = static_cast<uint32_t>(offset); |
|
return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12); |
|
} |
|
|
|
// Insert OFFSET to a 32-bit THUMB conditional branch and return the lower |
|
// instruction. LOWER_INSN is the original lower instruction of the branch. |
|
// The caller is responsible for overflow checking. |
|
static inline uint16_t |
|
thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset) |
|
{ |
|
uint32_t bits = static_cast<uint32_t>(offset); |
|
uint32_t j2 = (bits & 0x00080000U) >> 19; |
|
uint32_t j1 = (bits & 0x00040000U) >> 18; |
|
uint32_t lo = (bits & 0x00000ffeU) >> 1; |
|
|
|
return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo; |
|
} |
|
|
|
// R_ARM_ABS8: S + A |
|
static inline typename This::Status |
|
abs8(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval) |
|
{ |
|
typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
Valtype val = elfcpp::Swap<8, big_endian>::readval(wv); |
|
int32_t addend = Bits<8>::sign_extend32(val); |
|
Arm_address x = psymval->value(object, addend); |
|
val = Bits<32>::bit_select32(val, x, 0xffU); |
|
elfcpp::Swap<8, big_endian>::writeval(wv, val); |
|
|
|
// R_ARM_ABS8 permits signed or unsigned results. |
|
return (Bits<8>::has_signed_unsigned_overflow32(x) |
|
? This::STATUS_OVERFLOW |
|
: This::STATUS_OKAY); |
|
} |
|
|
|
// R_ARM_THM_ABS5: S + A |
|
static inline typename This::Status |
|
thm_abs5(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval) |
|
{ |
|
typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
|
typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
Valtype val = elfcpp::Swap<16, big_endian>::readval(wv); |
|
Reltype addend = (val & 0x7e0U) >> 6; |
|
Reltype x = psymval->value(object, addend); |
|
val = Bits<32>::bit_select32(val, x << 6, 0x7e0U); |
|
elfcpp::Swap<16, big_endian>::writeval(wv, val); |
|
return (Bits<5>::has_overflow32(x) |
|
? This::STATUS_OVERFLOW |
|
: This::STATUS_OKAY); |
|
} |
|
|
|
// R_ARM_ABS12: S + A |
|
static inline typename This::Status |
|
abs12(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval) |
|
{ |
|
typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
|
typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); |
|
Reltype addend = val & 0x0fffU; |
|
Reltype x = psymval->value(object, addend); |
|
val = Bits<32>::bit_select32(val, x, 0x0fffU); |
|
elfcpp::Swap<32, big_endian>::writeval(wv, val); |
|
return (Bits<12>::has_overflow32(x) |
|
? This::STATUS_OVERFLOW |
|
: This::STATUS_OKAY); |
|
} |
|
|
|
// R_ARM_ABS16: S + A |
|
static inline typename This::Status |
|
abs16(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval) |
|
{ |
|
typedef typename elfcpp::Swap_unaligned<16, big_endian>::Valtype Valtype; |
|
Valtype val = elfcpp::Swap_unaligned<16, big_endian>::readval(view); |
|
int32_t addend = Bits<16>::sign_extend32(val); |
|
Arm_address x = psymval->value(object, addend); |
|
val = Bits<32>::bit_select32(val, x, 0xffffU); |
|
elfcpp::Swap_unaligned<16, big_endian>::writeval(view, val); |
|
|
|
// R_ARM_ABS16 permits signed or unsigned results. |
|
return (Bits<16>::has_signed_unsigned_overflow32(x) |
|
? This::STATUS_OVERFLOW |
|
: This::STATUS_OKAY); |
|
} |
|
|
|
// R_ARM_ABS32: (S + A) | T |
|
static inline typename This::Status |
|
abs32(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval, |
|
Arm_address thumb_bit) |
|
{ |
|
typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype; |
|
Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view); |
|
Valtype x = psymval->value(object, addend) | thumb_bit; |
|
elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x); |
|
return This::STATUS_OKAY; |
|
} |
|
|
|
// R_ARM_REL32: (S + A) | T - P |
|
static inline typename This::Status |
|
rel32(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval, |
|
Arm_address address, |
|
Arm_address thumb_bit) |
|
{ |
|
typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype; |
|
Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view); |
|
Valtype x = (psymval->value(object, addend) | thumb_bit) - address; |
|
elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x); |
|
return This::STATUS_OKAY; |
|
} |
|
|
|
// R_ARM_THM_JUMP24: (S + A) | T - P |
|
static typename This::Status |
|
thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object, |
|
const Symbol_value<32>* psymval, Arm_address address, |
|
Arm_address thumb_bit); |
|
|
|
// R_ARM_THM_JUMP6: S + A – P |
|
static inline typename This::Status |
|
thm_jump6(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval, |
|
Arm_address address) |
|
{ |
|
typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
|
typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
Valtype val = elfcpp::Swap<16, big_endian>::readval(wv); |
|
// bit[9]:bit[7:3]:’0’ (mask: 0x02f8) |
|
Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2)); |
|
Reltype x = (psymval->value(object, addend) - address); |
|
val = (val & 0xfd07) | ((x & 0x0040) << 3) | ((val & 0x003e) << 2); |
|
elfcpp::Swap<16, big_endian>::writeval(wv, val); |
|
// CZB does only forward jumps. |
|
return ((x > 0x007e) |
|
? This::STATUS_OVERFLOW |
|
: This::STATUS_OKAY); |
|
} |
|
|
|
// R_ARM_THM_JUMP8: S + A – P |
|
static inline typename This::Status |
|
thm_jump8(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval, |
|
Arm_address address) |
|
{ |
|
typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
Valtype val = elfcpp::Swap<16, big_endian>::readval(wv); |
|
int32_t addend = Bits<8>::sign_extend32((val & 0x00ff) << 1); |
|
int32_t x = (psymval->value(object, addend) - address); |
|
elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xff00) |
|
| ((x & 0x01fe) >> 1))); |
|
// We do a 9-bit overflow check because x is right-shifted by 1 bit. |
|
return (Bits<9>::has_overflow32(x) |
|
? This::STATUS_OVERFLOW |
|
: This::STATUS_OKAY); |
|
} |
|
|
|
// R_ARM_THM_JUMP11: S + A – P |
|
static inline typename This::Status |
|
thm_jump11(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval, |
|
Arm_address address) |
|
{ |
|
typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
Valtype val = elfcpp::Swap<16, big_endian>::readval(wv); |
|
int32_t addend = Bits<11>::sign_extend32((val & 0x07ff) << 1); |
|
int32_t x = (psymval->value(object, addend) - address); |
|
elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xf800) |
|
| ((x & 0x0ffe) >> 1))); |
|
// We do a 12-bit overflow check because x is right-shifted by 1 bit. |
|
return (Bits<12>::has_overflow32(x) |
|
? This::STATUS_OVERFLOW |
|
: This::STATUS_OKAY); |
|
} |
|
|
|
// R_ARM_BASE_PREL: B(S) + A - P |
|
static inline typename This::Status |
|
base_prel(unsigned char* view, |
|
Arm_address origin, |
|
Arm_address address) |
|
{ |
|
Base::rel32(view, origin - address); |
|
return STATUS_OKAY; |
|
} |
|
|
|
// R_ARM_BASE_ABS: B(S) + A |
|
static inline typename This::Status |
|
base_abs(unsigned char* view, |
|
Arm_address origin) |
|
{ |
|
Base::rel32(view, origin); |
|
return STATUS_OKAY; |
|
} |
|
|
|
// R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG |
|
static inline typename This::Status |
|
got_brel(unsigned char* view, |
|
typename elfcpp::Swap<32, big_endian>::Valtype got_offset) |
|
{ |
|
Base::rel32(view, got_offset); |
|
return This::STATUS_OKAY; |
|
} |
|
|
|
// R_ARM_GOT_PREL: GOT(S) + A - P |
|
static inline typename This::Status |
|
got_prel(unsigned char* view, |
|
Arm_address got_entry, |
|
Arm_address address) |
|
{ |
|
Base::rel32(view, got_entry - address); |
|
return This::STATUS_OKAY; |
|
} |
|
|
|
// R_ARM_PREL: (S + A) | T - P |
|
static inline typename This::Status |
|
prel31(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval, |
|
Arm_address address, |
|
Arm_address thumb_bit) |
|
{ |
|
typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype; |
|
Valtype val = elfcpp::Swap_unaligned<32, big_endian>::readval(view); |
|
Valtype addend = Bits<31>::sign_extend32(val); |
|
Valtype x = (psymval->value(object, addend) | thumb_bit) - address; |
|
val = Bits<32>::bit_select32(val, x, 0x7fffffffU); |
|
elfcpp::Swap_unaligned<32, big_endian>::writeval(view, val); |
|
return (Bits<31>::has_overflow32(x) |
|
? This::STATUS_OVERFLOW |
|
: This::STATUS_OKAY); |
|
} |
|
|
|
// R_ARM_MOVW_ABS_NC: (S + A) | T (relative address base is ) |
|
// R_ARM_MOVW_PREL_NC: (S + A) | T - P |
|
// R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S) |
|
// R_ARM_MOVW_BREL: ((S + A) | T) - B(S) |
|
static inline typename This::Status |
|
movw(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval, |
|
Arm_address relative_address_base, |
|
Arm_address thumb_bit, |
|
bool check_overflow) |
|
{ |
|
typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); |
|
Valtype addend = This::extract_arm_movw_movt_addend(val); |
|
Valtype x = ((psymval->value(object, addend) | thumb_bit) |
|
- relative_address_base); |
|
val = This::insert_val_arm_movw_movt(val, x); |
|
elfcpp::Swap<32, big_endian>::writeval(wv, val); |
|
return ((check_overflow && Bits<16>::has_overflow32(x)) |
|
? This::STATUS_OVERFLOW |
|
: This::STATUS_OKAY); |
|
} |
|
|
|
// R_ARM_MOVT_ABS: S + A (relative address base is 0) |
|
// R_ARM_MOVT_PREL: S + A - P |
|
// R_ARM_MOVT_BREL: S + A - B(S) |
|
static inline typename This::Status |
|
movt(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval, |
|
Arm_address relative_address_base) |
|
{ |
|
typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); |
|
Valtype addend = This::extract_arm_movw_movt_addend(val); |
|
Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16; |
|
val = This::insert_val_arm_movw_movt(val, x); |
|
elfcpp::Swap<32, big_endian>::writeval(wv, val); |
|
// FIXME: IHI0044D says that we should check for overflow. |
|
return This::STATUS_OKAY; |
|
} |
|
|
|
// R_ARM_THM_MOVW_ABS_NC: S + A | T (relative_address_base is 0) |
|
// R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P |
|
// R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S) |
|
// R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S) |
|
static inline typename This::Status |
|
thm_movw(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval, |
|
Arm_address relative_address_base, |
|
Arm_address thumb_bit, |
|
bool check_overflow) |
|
{ |
|
typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
|
typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16) |
|
| elfcpp::Swap<16, big_endian>::readval(wv + 1); |
|
Reltype addend = This::extract_thumb_movw_movt_addend(val); |
|
Reltype x = |
|
(psymval->value(object, addend) | thumb_bit) - relative_address_base; |
|
val = This::insert_val_thumb_movw_movt(val, x); |
|
elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16); |
|
elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff); |
|
return ((check_overflow && Bits<16>::has_overflow32(x)) |
|
? This::STATUS_OVERFLOW |
|
: This::STATUS_OKAY); |
|
} |
|
|
|
// R_ARM_THM_MOVT_ABS: S + A (relative address base is 0) |
|
// R_ARM_THM_MOVT_PREL: S + A - P |
|
// R_ARM_THM_MOVT_BREL: S + A - B(S) |
|
static inline typename This::Status |
|
thm_movt(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval, |
|
Arm_address relative_address_base) |
|
{ |
|
typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
|
typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16) |
|
| elfcpp::Swap<16, big_endian>::readval(wv + 1); |
|
Reltype addend = This::extract_thumb_movw_movt_addend(val); |
|
Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16; |
|
val = This::insert_val_thumb_movw_movt(val, x); |
|
elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16); |
|
elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff); |
|
return This::STATUS_OKAY; |
|
} |
|
|
|
// R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32) |
|
static inline typename This::Status |
|
thm_alu11(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval, |
|
Arm_address address, |
|
Arm_address thumb_bit) |
|
{ |
|
typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
|
typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16) |
|
| elfcpp::Swap<16, big_endian>::readval(wv + 1); |
|
|
|
// f e d c b|a|9|8 7 6 5|4|3 2 1 0||f|e d c|b a 9 8|7 6 5 4 3 2 1 0 |
|
// ----------------------------------------------------------------------- |
|
// ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd |imm8 |
|
// ADDW 1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd |imm8 |
|
// ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd |imm8 |
|
// SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd |imm8 |
|
// SUBW 1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd |imm8 |
|
// ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd |imm8 |
|
|
|
// Determine a sign for the addend. |
|
const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000 |
|
|| (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1; |
|
// Thumb2 addend encoding: |
|
// imm12 := i | imm3 | imm8 |
|
int32_t addend = (insn & 0xff) |
|
| ((insn & 0x00007000) >> 4) |
|
| ((insn & 0x04000000) >> 15); |
|
// Apply a sign to the added. |
|
addend *= sign; |
|
|
|
int32_t x = (psymval->value(object, addend) | thumb_bit) |
|
- (address & 0xfffffffc); |
|
Reltype val = abs(x); |
|
// Mask out the value and a distinct part of the ADD/SUB opcode |
|
// (bits 7:5 of opword). |
|
insn = (insn & 0xfb0f8f00) |
|
| (val & 0xff) |
|
| ((val & 0x700) << 4) |
|
| ((val & 0x800) << 15); |
|
// Set the opcode according to whether the value to go in the |
|
// place is negative. |
|
if (x < 0) |
|
insn |= 0x00a00000; |
|
|
|
elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16); |
|
elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff); |
|
return ((val > 0xfff) ? |
|
This::STATUS_OVERFLOW : This::STATUS_OKAY); |
|
} |
|
|
|
// R_ARM_THM_PC8: S + A - Pa (Thumb) |
|
static inline typename This::Status |
|
thm_pc8(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval, |
|
Arm_address address) |
|
{ |
|
typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
|
typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv); |
|
Reltype addend = ((insn & 0x00ff) << 2); |
|
int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc)); |
|
Reltype val = abs(x); |
|
insn = (insn & 0xff00) | ((val & 0x03fc) >> 2); |
|
|
|
elfcpp::Swap<16, big_endian>::writeval(wv, insn); |
|
return ((val > 0x03fc) |
|
? This::STATUS_OVERFLOW |
|
: This::STATUS_OKAY); |
|
} |
|
|
|
// R_ARM_THM_PC12: S + A - Pa (Thumb32) |
|
static inline typename This::Status |
|
thm_pc12(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval, |
|
Arm_address address) |
|
{ |
|
typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
|
typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16) |
|
| elfcpp::Swap<16, big_endian>::readval(wv + 1); |
|
// Determine a sign for the addend (positive if the U bit is 1). |
|
const int sign = (insn & 0x00800000) ? 1 : -1; |
|
int32_t addend = (insn & 0xfff); |
|
// Apply a sign to the added. |
|
addend *= sign; |
|
|
|
int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc)); |
|
Reltype val = abs(x); |
|
// Mask out and apply the value and the U bit. |
|
insn = (insn & 0xff7ff000) | (val & 0xfff); |
|
// Set the U bit according to whether the value to go in the |
|
// place is positive. |
|
if (x >= 0) |
|
insn |= 0x00800000; |
|
|
|
elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16); |
|
elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff); |
|
return ((val > 0xfff) ? |
|
This::STATUS_OVERFLOW : This::STATUS_OKAY); |
|
} |
|
|
|
// R_ARM_V4BX |
|
static inline typename This::Status |
|
v4bx(const Relocate_info<32, big_endian>* relinfo, |
|
unsigned char* view, |
|
const Arm_relobj<big_endian>* object, |
|
const Arm_address address, |
|
const bool is_interworking) |
|
{ |
|
|
|
typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); |
|
|
|
// Ensure that we have a BX instruction. |
|
gold_assert((val & 0x0ffffff0) == 0x012fff10); |
|
const uint32_t reg = (val & 0xf); |
|
if (is_interworking && reg != 0xf) |
|
{ |
|
Stub_table<big_endian>* stub_table = |
|
object->stub_table(relinfo->data_shndx); |
|
gold_assert(stub_table != NULL); |
|
|
|
Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg); |
|
gold_assert(stub != NULL); |
|
|
|
int32_t veneer_address = |
|
stub_table->address() + stub->offset() - 8 - address; |
|
gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET) |
|
&& (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET)); |
|
// Replace with a branch to veneer (B <addr>) |
|
val = (val & 0xf0000000) | 0x0a000000 |
|
| ((veneer_address >> 2) & 0x00ffffff); |
|
} |
|
else |
|
{ |
|
// Preserve Rm (lowest four bits) and the condition code |
|
// (highest four bits). Other bits encode MOV PC,Rm. |
|
val = (val & 0xf000000f) | 0x01a0f000; |
|
} |
|
elfcpp::Swap<32, big_endian>::writeval(wv, val); |
|
return This::STATUS_OKAY; |
|
} |
|
|
|
// R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P |
|
// R_ARM_ALU_PC_G0: ((S + A) | T) - P |
|
// R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P |
|
// R_ARM_ALU_PC_G1: ((S + A) | T) - P |
|
// R_ARM_ALU_PC_G2: ((S + A) | T) - P |
|
// R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S) |
|
// R_ARM_ALU_SB_G0: ((S + A) | T) - B(S) |
|
// R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S) |
|
// R_ARM_ALU_SB_G1: ((S + A) | T) - B(S) |
|
// R_ARM_ALU_SB_G2: ((S + A) | T) - B(S) |
|
static inline typename This::Status |
|
arm_grp_alu(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval, |
|
const int group, |
|
Arm_address address, |
|
Arm_address thumb_bit, |
|
bool check_overflow) |
|
{ |
|
gold_assert(group >= 0 && group < 3); |
|
typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv); |
|
|
|
// ALU group relocations are allowed only for the ADD/SUB instructions. |
|
// (0x00800000 - ADD, 0x00400000 - SUB) |
|
const Valtype opcode = insn & 0x01e00000; |
|
if (opcode != 0x00800000 && opcode != 0x00400000) |
|
return This::STATUS_BAD_RELOC; |
|
|
|
// Determine a sign for the addend. |
|
const int sign = (opcode == 0x00800000) ? 1 : -1; |
|
// shifter = rotate_imm * 2 |
|
const uint32_t shifter = (insn & 0xf00) >> 7; |
|
// Initial addend value. |
|
int32_t addend = insn & 0xff; |
|
// Rotate addend right by shifter. |
|
addend = (addend >> shifter) | (addend << (32 - shifter)); |
|
// Apply a sign to the added. |
|
addend *= sign; |
|
|
|
int32_t x = ((psymval->value(object, addend) | thumb_bit) - address); |
|
Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group); |
|
// Check for overflow if required |
|
if (check_overflow |
|
&& (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0)) |
|
return This::STATUS_OVERFLOW; |
|
|
|
// Mask out the value and the ADD/SUB part of the opcode; take care |
|
// not to destroy the S bit. |
|
insn &= 0xff1ff000; |
|
// Set the opcode according to whether the value to go in the |
|
// place is negative. |
|
insn |= ((x < 0) ? 0x00400000 : 0x00800000); |
|
// Encode the offset (encoded Gn). |
|
insn |= gn; |
|
|
|
elfcpp::Swap<32, big_endian>::writeval(wv, insn); |
|
return This::STATUS_OKAY; |
|
} |
|
|
|
// R_ARM_LDR_PC_G0: S + A - P |
|
// R_ARM_LDR_PC_G1: S + A - P |
|
// R_ARM_LDR_PC_G2: S + A - P |
|
// R_ARM_LDR_SB_G0: S + A - B(S) |
|
// R_ARM_LDR_SB_G1: S + A - B(S) |
|
// R_ARM_LDR_SB_G2: S + A - B(S) |
|
static inline typename This::Status |
|
arm_grp_ldr(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval, |
|
const int group, |
|
Arm_address address) |
|
{ |
|
gold_assert(group >= 0 && group < 3); |
|
typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv); |
|
|
|
const int sign = (insn & 0x00800000) ? 1 : -1; |
|
int32_t addend = (insn & 0xfff) * sign; |
|
int32_t x = (psymval->value(object, addend) - address); |
|
// Calculate the relevant G(n-1) value to obtain this stage residual. |
|
Valtype residual = |
|
Arm_relocate_functions::calc_grp_residual(abs(x), group - 1); |
|
if (residual >= 0x1000) |
|
return This::STATUS_OVERFLOW; |
|
|
|
// Mask out the value and U bit. |
|
insn &= 0xff7ff000; |
|
// Set the U bit for non-negative values. |
|
if (x >= 0) |
|
insn |= 0x00800000; |
|
insn |= residual; |
|
|
|
elfcpp::Swap<32, big_endian>::writeval(wv, insn); |
|
return This::STATUS_OKAY; |
|
} |
|
|
|
// R_ARM_LDRS_PC_G0: S + A - P |
|
// R_ARM_LDRS_PC_G1: S + A - P |
|
// R_ARM_LDRS_PC_G2: S + A - P |
|
// R_ARM_LDRS_SB_G0: S + A - B(S) |
|
// R_ARM_LDRS_SB_G1: S + A - B(S) |
|
// R_ARM_LDRS_SB_G2: S + A - B(S) |
|
static inline typename This::Status |
|
arm_grp_ldrs(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval, |
|
const int group, |
|
Arm_address address) |
|
{ |
|
gold_assert(group >= 0 && group < 3); |
|
typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv); |
|
|
|
const int sign = (insn & 0x00800000) ? 1 : -1; |
|
int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign; |
|
int32_t x = (psymval->value(object, addend) - address); |
|
// Calculate the relevant G(n-1) value to obtain this stage residual. |
|
Valtype residual = |
|
Arm_relocate_functions::calc_grp_residual(abs(x), group - 1); |
|
if (residual >= 0x100) |
|
return This::STATUS_OVERFLOW; |
|
|
|
// Mask out the value and U bit. |
|
insn &= 0xff7ff0f0; |
|
// Set the U bit for non-negative values. |
|
if (x >= 0) |
|
insn |= 0x00800000; |
|
insn |= ((residual & 0xf0) << 4) | (residual & 0xf); |
|
|
|
elfcpp::Swap<32, big_endian>::writeval(wv, insn); |
|
return This::STATUS_OKAY; |
|
} |
|
|
|
// R_ARM_LDC_PC_G0: S + A - P |
|
// R_ARM_LDC_PC_G1: S + A - P |
|
// R_ARM_LDC_PC_G2: S + A - P |
|
// R_ARM_LDC_SB_G0: S + A - B(S) |
|
// R_ARM_LDC_SB_G1: S + A - B(S) |
|
// R_ARM_LDC_SB_G2: S + A - B(S) |
|
static inline typename This::Status |
|
arm_grp_ldc(unsigned char* view, |
|
const Sized_relobj_file<32, big_endian>* object, |
|
const Symbol_value<32>* psymval, |
|
const int group, |
|
Arm_address address) |
|
{ |
|
gold_assert(group >= 0 && group < 3); |
|
typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv); |
|
|
|
const int sign = (insn & 0x00800000) ? 1 : -1; |
|
int32_t addend = ((insn & 0xff) << 2) * sign; |
|
int32_t x = (psymval->value(object, addend) - address); |
|
// Calculate the relevant G(n-1) value to obtain this stage residual. |
|
Valtype residual = |
|
Arm_relocate_functions::calc_grp_residual(abs(x), group - 1); |
|
if ((residual & 0x3) != 0 || residual >= 0x400) |
|
return This::STATUS_OVERFLOW; |
|
|
|
// Mask out the value and U bit. |
|
insn &= 0xff7fff00; |
|
// Set the U bit for non-negative values. |
|
if (x >= 0) |
|
insn |= 0x00800000; |
|
insn |= (residual >> 2); |
|
|
|
elfcpp::Swap<32, big_endian>::writeval(wv, insn); |
|
return This::STATUS_OKAY; |
|
} |
|
}; |
|
|
|
// Relocate ARM long branches. This handles relocation types |
|
// R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25. |
|
// If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly |
|
// undefined and we do not use PLT in this relocation. In such a case, |
|
// the branch is converted into an NOP. |
|
|
|
template<bool big_endian> |
|
typename Arm_relocate_functions<big_endian>::Status |
|
Arm_relocate_functions<big_endian>::arm_branch_common( |
|
unsigned int r_type, |
|
const Relocate_info<32, big_endian>* relinfo, |
|
unsigned char* view, |
|
const Sized_symbol<32>* gsym, |
|
const Arm_relobj<big_endian>* object, |
|
unsigned int r_sym, |
|
const Symbol_value<32>* psymval, |
|
Arm_address address, |
|
Arm_address thumb_bit, |
|
bool is_weakly_undefined_without_plt) |
|
{ |
|
typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); |
|
|
|
bool insn_is_b = (((val >> 28) & 0xf) <= 0xe) |
|
&& ((val & 0x0f000000UL) == 0x0a000000UL); |
|
bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL; |
|
bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe) |
|
&& ((val & 0x0f000000UL) == 0x0b000000UL); |
|
bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL; |
|
bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL; |
|
|
|
// Check that the instruction is valid. |
|
if (r_type == elfcpp::R_ARM_CALL) |
|
{ |
|
if (!insn_is_uncond_bl && !insn_is_blx) |
|
return This::STATUS_BAD_RELOC; |
|
} |
|
else if (r_type == elfcpp::R_ARM_JUMP24) |
|
{ |
|
if (!insn_is_b && !insn_is_cond_bl) |
|
return This::STATUS_BAD_RELOC; |
|
} |
|
else if (r_type == elfcpp::R_ARM_PLT32) |
|
{ |
|
if (!insn_is_any_branch) |
|
return This::STATUS_BAD_RELOC; |
|
} |
|
else if (r_type == elfcpp::R_ARM_XPC25) |
|
{ |
|
// FIXME: AAELF document IH0044C does not say much about it other |
|
// than it being obsolete. |
|
if (!insn_is_any_branch) |
|
return This::STATUS_BAD_RELOC; |
|
} |
|
else |
|
gold_unreachable(); |
|
|
|
// A branch to an undefined weak symbol is turned into a jump to |
|
// the next instruction unless a PLT entry will be created. |
|
// Do the same for local undefined symbols. |
|
// The jump to the next instruction is optimized as a NOP depending |
|
// on the architecture. |
|
const Target_arm<big_endian>* arm_target = |
|
Target_arm<big_endian>::default_target(); |
|
if (is_weakly_undefined_without_plt) |
|
{ |
|
gold_assert(!parameters->options().relocatable()); |
|
Valtype cond = val & 0xf0000000U; |
|
if (arm_target->may_use_arm_nop()) |
|
val = cond | 0x0320f000; |
|
else |
|
val = cond | 0x01a00000; // Using pre-UAL nop: mov r0, r0. |
|
elfcpp::Swap<32, big_endian>::writeval(wv, val); |
|
return This::STATUS_OKAY; |
|
} |
|
|
|
Valtype addend = Bits<26>::sign_extend32(val << 2); |
|
Valtype branch_target = psymval->value(object, addend); |
|
int32_t branch_offset = branch_target - address; |
|
|
|
// We need a stub if the branch offset is too large or if we need |
|
// to switch mode. |
|
bool may_use_blx = arm_target->may_use_v5t_interworking(); |
|
Reloc_stub* stub = NULL; |
|
|
|
if (!parameters->options().relocatable() |
|
&& (Bits<26>::has_overflow32(branch_offset) |
|
|| ((thumb_bit != 0) |
|
&& !(may_use_blx && r_type == elfcpp::R_ARM_CALL)))) |
|
{ |
|
Valtype unadjusted_branch_target = psymval->value(object, 0); |
|
|
|
Stub_type stub_type = |
|
Reloc_stub::stub_type_for_reloc(r_type, address, |
|
unadjusted_branch_target, |
|
(thumb_bit != 0)); |
|
if (stub_type != arm_stub_none) |
|
{ |
|
Stub_table<big_endian>* stub_table = |
|
object->stub_table(relinfo->data_shndx); |
|
gold_assert(stub_table != NULL); |
|
|
|
Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend); |
|
stub = stub_table->find_reloc_stub(stub_key); |
|
gold_assert(stub != NULL); |
|
thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0; |
|
branch_target = stub_table->address() + stub->offset() + addend; |
|
branch_offset = branch_target - address; |
|
gold_assert(!Bits<26>::has_overflow32(branch_offset)); |
|
} |
|
} |
|
|
|
// At this point, if we still need to switch mode, the instruction |
|
// must either be a BLX or a BL that can be converted to a BLX. |
|
if (thumb_bit != 0) |
|
{ |
|
// Turn BL to BLX. |
|
gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL); |
|
val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23); |
|
} |
|
|
|
val = Bits<32>::bit_select32(val, (branch_offset >> 2), 0xffffffUL); |
|
elfcpp::Swap<32, big_endian>::writeval(wv, val); |
|
return (Bits<26>::has_overflow32(branch_offset) |
|
? This::STATUS_OVERFLOW |
|
: This::STATUS_OKAY); |
|
} |
|
|
|
// Relocate THUMB long branches. This handles relocation types |
|
// R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22. |
|
// If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly |
|
// undefined and we do not use PLT in this relocation. In such a case, |
|
// the branch is converted into an NOP. |
|
|
|
template<bool big_endian> |
|
typename Arm_relocate_functions<big_endian>::Status |
|
Arm_relocate_functions<big_endian>::thumb_branch_common( |
|
unsigned int r_type, |
|
const Relocate_info<32, big_endian>* relinfo, |
|
unsigned char* view, |
|
const Sized_symbol<32>* gsym, |
|
const Arm_relobj<big_endian>* object, |
|
unsigned int r_sym, |
|
const Symbol_value<32>* psymval, |
|
Arm_address address, |
|
Arm_address thumb_bit, |
|
bool is_weakly_undefined_without_plt) |
|
{ |
|
typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv); |
|
uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1); |
|
|
|
// FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference |
|
// into account. |
|
bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U; |
|
bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U; |
|
|
|
// Check that the instruction is valid. |
|
if (r_type == elfcpp::R_ARM_THM_CALL) |
|
{ |
|
if (!is_bl_insn && !is_blx_insn) |
|
return This::STATUS_BAD_RELOC; |
|
} |
|
else if (r_type == elfcpp::R_ARM_THM_JUMP24) |
|
{ |
|
// This cannot be a BLX. |
|
if (!is_bl_insn) |
|
return This::STATUS_BAD_RELOC; |
|
} |
|
else if (r_type == elfcpp::R_ARM_THM_XPC22) |
|
{ |
|
// Check for Thumb to Thumb call. |
|
if (!is_blx_insn) |
|
return This::STATUS_BAD_RELOC; |
|
if (thumb_bit != 0) |
|
{ |
|
gold_warning(_("%s: Thumb BLX instruction targets " |
|
"thumb function '%s'."), |
|
object->name().c_str(), |
|
(gsym ? gsym->name() : "(local)")); |
|
// Convert BLX to BL. |
|
lower_insn |= 0x1000U; |
|
} |
|
} |
|
else |
|
gold_unreachable(); |
|
|
|
// A branch to an undefined weak symbol is turned into a jump to |
|
// the next instruction unless a PLT entry will be created. |
|
// The jump to the next instruction is optimized as a NOP.W for |
|
// Thumb-2 enabled architectures. |
|
const Target_arm<big_endian>* arm_target = |
|
Target_arm<big_endian>::default_target(); |
|
if (is_weakly_undefined_without_plt) |
|
{ |
|
gold_assert(!parameters->options().relocatable()); |
|
if (arm_target->may_use_thumb2_nop()) |
|
{ |
|
elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af); |
|
elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000); |
|
} |
|
else |
|
{ |
|
elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000); |
|
elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00); |
|
} |
|
return This::STATUS_OKAY; |
|
} |
|
|
|
int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn); |
|
Arm_address branch_target = psymval->value(object, addend); |
|
|
|
// For BLX, bit 1 of target address comes from bit 1 of base address. |
|
bool may_use_blx = arm_target->may_use_v5t_interworking(); |
|
if (thumb_bit == 0 && may_use_blx) |
|
branch_target = Bits<32>::bit_select32(branch_target, address, 0x2); |
|
|
|
int32_t branch_offset = branch_target - address; |
|
|
|
// We need a stub if the branch offset is too large or if we need |
|
// to switch mode. |
|
bool thumb2 = arm_target->using_thumb2(); |
|
if (!parameters->options().relocatable() |
|
&& ((!thumb2 && Bits<23>::has_overflow32(branch_offset)) |
|
|| (thumb2 && Bits<25>::has_overflow32(branch_offset)) |
|
|| ((thumb_bit == 0) |
|
&& (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx) |
|
|| r_type == elfcpp::R_ARM_THM_JUMP24)))) |
|
{ |
|
Arm_address unadjusted_branch_target = psymval->value(object, 0); |
|
|
|
Stub_type stub_type = |
|
Reloc_stub::stub_type_for_reloc(r_type, address, |
|
unadjusted_branch_target, |
|
(thumb_bit != 0)); |
|
|
|
if (stub_type != arm_stub_none) |
|
{ |
|
Stub_table<big_endian>* stub_table = |
|
object->stub_table(relinfo->data_shndx); |
|
gold_assert(stub_table != NULL); |
|
|
|
Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend); |
|
Reloc_stub* stub = stub_table->find_reloc_stub(stub_key); |
|
gold_assert(stub != NULL); |
|
thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0; |
|
branch_target = stub_table->address() + stub->offset() + addend; |
|
if (thumb_bit == 0 && may_use_blx) |
|
branch_target = Bits<32>::bit_select32(branch_target, address, 0x2); |
|
branch_offset = branch_target - address; |
|
} |
|
} |
|
|
|
// At this point, if we still need to switch mode, the instruction |
|
// must either be a BLX or a BL that can be converted to a BLX. |
|
if (thumb_bit == 0) |
|
{ |
|
gold_assert(may_use_blx |
|
&& (r_type == elfcpp::R_ARM_THM_CALL |
|
|| r_type == elfcpp::R_ARM_THM_XPC22)); |
|
// Make sure this is a BLX. |
|
lower_insn &= ~0x1000U; |
|
} |
|
else |
|
{ |
|
// Make sure this is a BL. |
|
lower_insn |= 0x1000U; |
|
} |
|
|
|
// For a BLX instruction, make sure that the relocation is rounded up |
|
// to a word boundary. This follows the semantics of the instruction |
|
// which specifies that bit 1 of the target address will come from bit |
|
// 1 of the base address. |
|
if ((lower_insn & 0x5000U) == 0x4000U) |
|
gold_assert((branch_offset & 3) == 0); |
|
|
|
// Put BRANCH_OFFSET back into the insn. Assumes two's complement. |
|
// We use the Thumb-2 encoding, which is safe even if dealing with |
|
// a Thumb-1 instruction by virtue of our overflow check above. */ |
|
upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset); |
|
lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset); |
|
|
|
elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn); |
|
elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn); |
|
|
|
gold_assert(!Bits<25>::has_overflow32(branch_offset)); |
|
|
|
return ((thumb2 |
|
? Bits<25>::has_overflow32(branch_offset) |
|
: Bits<23>::has_overflow32(branch_offset)) |
|
? This::STATUS_OVERFLOW |
|
: This::STATUS_OKAY); |
|
} |
|
|
|
// Relocate THUMB-2 long conditional branches. |
|
// If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly |
|
// undefined and we do not use PLT in this relocation. In such a case, |
|
// the branch is converted into an NOP. |
|
|
|
template<bool big_endian> |
|
typename Arm_relocate_functions<big_endian>::Status |
|
Arm_relocate_functions<big_endian>::thm_jump19( |
|
unsigned char* view, |
|
const Arm_relobj<big_endian>* object, |
|
const Symbol_value<32>* psymval, |
|
Arm_address address, |
|
Arm_address thumb_bit) |
|
{ |
|
typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(view); |
|
uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv); |
|
uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1); |
|
int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn); |
|
|
|
Arm_address branch_target = psymval->value(object, addend); |
|
int32_t branch_offset = branch_target - address; |
|
|
|
// ??? Should handle interworking? GCC might someday try to |
|
// use this for tail calls. |
|
// FIXME: We do support thumb entry to PLT yet. |
|
if (thumb_bit == 0) |
|
{ |
|
gold_error(_("conditional branch to PLT in THUMB-2 not supported yet.")); |
|
return This::STATUS_BAD_RELOC; |
|
} |
|
|
|
// Put RELOCATION back into the insn. |
|
upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset); |
|
lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset); |
|
|
|
// Put the relocated value back in the object file: |
|
elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn); |
|
elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn); |
|
|
|
return (Bits<21>::has_overflow32(branch_offset) |
|
? This::STATUS_OVERFLOW |
|
: This::STATUS_OKAY); |
|
} |
|
|
|
// Get the GOT section, creating it if necessary. |
|
|
|
template<bool big_endian> |
|
Arm_output_data_got<big_endian>* |
|
Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout) |
|
{ |
|
if (this->got_ == NULL) |
|
{ |
|
gold_assert(symtab != NULL && layout != NULL); |
|
|
|
// When using -z now, we can treat .got as a relro section. |
|
// Without -z now, it is modified after program startup by lazy |
|
// PLT relocations. |
|
bool is_got_relro = parameters->options().now(); |
|
Output_section_order got_order = (is_got_relro |
|
? ORDER_RELRO_LAST |
|
: ORDER_DATA); |
|
|
|
// Unlike some targets (.e.g x86), ARM does not use separate .got and |
|
// .got.plt sections in output. The output .got section contains both |
|
// PLT and non-PLT GOT entries. |
|
this->got_ = new Arm_output_data_got<big_endian>(symtab, layout); |
|
|
|
layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, |
|
(elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE), |
|
this->got_, got_order, is_got_relro); |
|
|
|
// The old GNU linker creates a .got.plt section. We just |
|
// create another set of data in the .got section. Note that we |
|
// always create a PLT if we create a GOT, although the PLT |
|
// might be empty. |
|
this->got_plt_ = new Output_data_space(4, "** GOT PLT"); |
|
layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, |
|
(elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE), |
|
this->got_plt_, got_order, is_got_relro); |
|
|
|
// The first three entries are reserved. |
|
this->got_plt_->set_current_data_size(3 * 4); |
|
|
|
// Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT. |
|
symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL, |
|
Symbol_table::PREDEFINED, |
|
this->got_plt_, |
|
0, 0, elfcpp::STT_OBJECT, |
|
elfcpp::STB_LOCAL, |
|
elfcpp::STV_HIDDEN, 0, |
|
false, false); |
|
|
|
// If there are any IRELATIVE relocations, they get GOT entries |
|
// in .got.plt after the jump slot entries. |
|
this->got_irelative_ = new Output_data_space(4, "** GOT IRELATIVE PLT"); |
|
layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, |
|
(elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE), |
|
this->got_irelative_, |
|
got_order, is_got_relro); |
|
|
|
} |
|
return this->got_; |
|
} |
|
|
|
// Get the dynamic reloc section, creating it if necessary. |
|
|
|
template<bool big_endian> |
|
typename Target_arm<big_endian>::Reloc_section* |
|
Target_arm<big_endian>::rel_dyn_section(Layout* layout) |
|
{ |
|
if (this->rel_dyn_ == NULL) |
|
{ |
|
gold_assert(layout != NULL); |
|
// Create both relocation sections in the same place, so as to ensure |
|
// their relative order in the output section. |
|
this->rel_dyn_ = new Reloc_section(parameters->options().combreloc()); |
|
this->rel_irelative_ = new Reloc_section(false); |
|
layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL, |
|
elfcpp::SHF_ALLOC, this->rel_dyn_, |
|
ORDER_DYNAMIC_RELOCS, false); |
|
layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL, |
|
elfcpp::SHF_ALLOC, this->rel_irelative_, |
|
ORDER_DYNAMIC_RELOCS, false); |
|
} |
|
return this->rel_dyn_; |
|
} |
|
|
|
|
|
// Get the section to use for IRELATIVE relocs, creating it if necessary. These |
|
// go in .rela.dyn, but only after all other dynamic relocations. They need to |
|
// follow the other dynamic relocations so that they can refer to global |
|
// variables initialized by those relocs. |
|
|
|
template<bool big_endian> |
|
typename Target_arm<big_endian>::Reloc_section* |
|
Target_arm<big_endian>::rel_irelative_section(Layout* layout) |
|
{ |
|
if (this->rel_irelative_ == NULL) |
|
{ |
|
// Delegate the creation to rel_dyn_section so as to ensure their order in |
|
// the output section. |
|
this->rel_dyn_section(layout); |
|
gold_assert(this->rel_irelative_ != NULL |
|
&& (this->rel_dyn_->output_section() |
|
== this->rel_irelative_->output_section())); |
|
} |
|
return this->rel_irelative_; |
|
} |
|
|
|
|
|
// Insn_template methods. |
|
|
|
// Return byte size of an instruction template. |
|
|
|
size_t |
|
Insn_template::size() const |
|
{ |
|
switch (this->type()) |
|
{ |
|
case THUMB16_TYPE: |
|
case THUMB16_SPECIAL_TYPE: |
|
return 2; |
|
case ARM_TYPE: |
|
case THUMB32_TYPE: |
|
case DATA_TYPE: |
|
return 4; |
|
default: |
|
gold_unreachable(); |
|
} |
|
} |
|
|
|
// Return alignment of an instruction template. |
|
|
|
unsigned |
|
Insn_template::alignment() const |
|
{ |
|
switch (this->type()) |
|
{ |
|
case THUMB16_TYPE: |
|
case THUMB16_SPECIAL_TYPE: |
|
case THUMB32_TYPE: |
|
return 2; |
|
case ARM_TYPE: |
|
case DATA_TYPE: |
|
return 4; |
|
default: |
|
gold_unreachable(); |
|
} |
|
} |
|
|
|
// Stub_template methods. |
|
|
|
Stub_template::Stub_template( |
|
Stub_type type, const Insn_template* insns, |
|
size_t insn_count) |
|
: type_(type), insns_(insns), insn_count_(insn_count), alignment_(1), |
|
entry_in_thumb_mode_(false), relocs_() |
|
{ |
|
off_t offset = 0; |
|
|
|
// Compute byte size and alignment of stub template. |
|
for (size_t i = 0; i < insn_count; i++) |
|
{ |
|
unsigned insn_alignment = insns[i].alignment(); |
|
size_t insn_size = insns[i].size(); |
|
gold_assert((offset & (insn_alignment - 1)) == 0); |
|
this->alignment_ = std::max(this->alignment_, insn_alignment); |
|
switch (insns[i].type()) |
|
{ |
|
case Insn_template::THUMB16_TYPE: |
|
case Insn_template::THUMB16_SPECIAL_TYPE: |
|
if (i == 0) |
|
this->entry_in_thumb_mode_ = true; |
|
break; |
|
|
|
case Insn_template::THUMB32_TYPE: |
|
if (insns[i].r_type() != elfcpp::R_ARM_NONE) |
|
this->relocs_.push_back(Reloc(i, offset)); |
|
if (i == 0) |
|
this->entry_in_thumb_mode_ = true; |
|
break; |
|
|
|
case Insn_template::ARM_TYPE: |
|
// Handle cases where the target is encoded within the |
|
// instruction. |
|
if (insns[i].r_type() == elfcpp::R_ARM_JUMP24) |
|
this->relocs_.push_back(Reloc(i, offset)); |
|
break; |
|
|
|
case Insn_template::DATA_TYPE: |
|
// Entry point cannot be data. |
|
gold_assert(i != 0); |
|
this->relocs_.push_back(Reloc(i, offset)); |
|
break; |
|
|
|
default: |
|
gold_unreachable(); |
|
} |
|
offset += insn_size; |
|
} |
|
this->size_ = offset; |
|
} |
|
|
|
// Stub methods. |
|
|
|
// Template to implement do_write for a specific target endianness. |
|
|
|
template<bool big_endian> |
|
void inline |
|
Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size) |
|
{ |
|
const Stub_template* stub_template = this->stub_template(); |
|
const Insn_template* insns = stub_template->insns(); |
|
|
|
// FIXME: We do not handle BE8 encoding yet. |
|
unsigned char* pov = view; |
|
for (size_t i = 0; i < stub_template->insn_count(); i++) |
|
{ |
|
switch (insns[i].type()) |
|
{ |
|
case Insn_template::THUMB16_TYPE: |
|
elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff); |
|
break; |
|
case Insn_template::THUMB16_SPECIAL_TYPE: |
|
elfcpp::Swap<16, big_endian>::writeval( |
|
pov, |
|
this->thumb16_special(i)); |
|
break; |
|
case Insn_template::THUMB32_TYPE: |
|
{ |
|
uint32_t hi = (insns[i].data() >> 16) & 0xffff; |
|
uint32_t lo = insns[i].data() & 0xffff; |
|
elfcpp::Swap<16, big_endian>::writeval(pov, hi); |
|
elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo); |
|
} |
|
break; |
|
case Insn_template::ARM_TYPE: |
|
case Insn_template::DATA_TYPE: |
|
elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data()); |
|
break; |
|
default: |
|
gold_unreachable(); |
|
} |
|
pov += insns[i].size(); |
|
} |
|
gold_assert(static_cast<section_size_type>(pov - view) == view_size); |
|
} |
|
|
|
// Reloc_stub::Key methods. |
|
|
|
// Dump a Key as a string for debugging. |
|
|
|
std::string |
|
Reloc_stub::Key::name() const |
|
{ |
|
if (this->r_sym_ == invalid_index) |
|
{ |
|
// Global symbol key name |
|
// <stub-type>:<symbol name>:<addend>. |
|
const std::string sym_name = this->u_.symbol->name(); |
|
// We need to print two hex number and two colons. So just add 100 bytes |
|
// to the symbol name size. |
|
size_t len = sym_name.size() + 100; |
|
char* buffer = new char[len]; |
|
int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_, |
|
sym_name.c_str(), this->addend_); |
|
gold_assert(c > 0 && c < static_cast<int>(len)); |
|
delete[] buffer; |
|
return std::string(buffer); |
|
} |
|
else |
|
{ |
|
// local symbol key name |
|
// <stub-type>:<object>:<r_sym>:<addend>. |
|
const size_t len = 200; |
|
char buffer[len]; |
|
int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_, |
|
this->u_.relobj, this->r_sym_, this->addend_); |
|
gold_assert(c > 0 && c < static_cast<int>(len)); |
|
return std::string(buffer); |
|
} |
|
} |
|
|
|
// Reloc_stub methods. |
|
|
|
// Determine the type of stub needed, if any, for a relocation of R_TYPE at |
|
// LOCATION to DESTINATION. |
|
// This code is based on the arm_type_of_stub function in |
|
// bfd/elf32-arm.c. We have changed the interface a little to keep the Stub |
|
// class simple. |
|
|
|
Stub_type |
|
Reloc_stub::stub_type_for_reloc( |
|
unsigned int r_type, |
|
Arm_address location, |
|
Arm_address destination, |
|
bool target_is_thumb) |
|
{ |
|
Stub_type stub_type = arm_stub_none; |
|
|
|
// This is a bit ugly but we want to avoid using a templated class for |
|
// big and little endianities. |
|
bool may_use_blx; |
|
bool should_force_pic_veneer = parameters->options().pic_veneer(); |
|
bool thumb2; |
|
bool thumb_only; |
|
if (parameters->target().is_big_endian()) |
|
{ |
|
const Target_arm<true>* big_endian_target = |
|
Target_arm<true>::default_target(); |
|
may_use_blx = big_endian_target->may_use_v5t_interworking(); |
|
should_force_pic_veneer |= big_endian_target->should_force_pic_veneer(); |
|
thumb2 = big_endian_target->using_thumb2(); |
|
thumb_only = big_endian_target->using_thumb_only(); |
|
} |
|
else |
|
{ |
|
const Target_arm<false>* little_endian_target = |
|
Target_arm<false>::default_target(); |
|
may_use_blx = little_endian_target->may_use_v5t_interworking(); |
|
should_force_pic_veneer |= |
|
little_endian_target->should_force_pic_veneer(); |
|
thumb2 = little_endian_target->using_thumb2(); |
|
thumb_only = little_endian_target->using_thumb_only(); |
|
} |
|
|
|
int64_t branch_offset; |
|
bool output_is_position_independent = |
|
parameters->options().output_is_position_independent(); |
|
if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24) |
|
{ |
|
// For THUMB BLX instruction, bit 1 of target comes from bit 1 of the |
|
// base address (instruction address + 4). |
|
if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb) |
|
destination = Bits<32>::bit_select32(destination, location, 0x2); |
|
branch_offset = static_cast<int64_t>(destination) - location; |
|
|
|
// Handle cases where: |
|
// - this call goes too far (different Thumb/Thumb2 max |
|
// distance) |
|
// - it's a Thumb->Arm call and blx is not available, or it's a |
|
// Thumb->Arm branch (not bl). A stub is needed in this case. |
|
if ((!thumb2 |
|
&& (branch_offset > THM_MAX_FWD_BRANCH_OFFSET |
|
|| (branch_offset < THM_MAX_BWD_BRANCH_OFFSET))) |
|
|| (thumb2 |
|
&& (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET |
|
|| (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET))) |
|
|| ((!target_is_thumb) |
|
&& (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx) |
|
|| (r_type == elfcpp::R_ARM_THM_JUMP24)))) |
|
{ |
|
if (target_is_thumb) |
|
{ |
|
// Thumb to thumb. |
|
if (!thumb_only) |
|
{ |
|
stub_type = (output_is_position_independent |
|
|| should_force_pic_veneer) |
|
// PIC stubs. |
|
? ((may_use_blx |
|
&& (r_type == elfcpp::R_ARM_THM_CALL)) |
|
// V5T and above. Stub starts with ARM code, so |
|
// we must be able to switch mode before |
|
// reaching it, which is only possible for 'bl' |
|
// (ie R_ARM_THM_CALL relocation). |
|
? arm_stub_long_branch_any_thumb_pic |
|
// On V4T, use Thumb code only. |
|
: arm_stub_long_branch_v4t_thumb_thumb_pic) |
|
|
|
// non-PIC stubs. |
|
: ((may_use_blx |
|
&& (r_type == elfcpp::R_ARM_THM_CALL)) |
|
? arm_stub_long_branch_any_any // V5T and above. |
|
: arm_stub_long_branch_v4t_thumb_thumb); // V4T. |
|
} |
|
else |
|
{ |
|
stub_type = (output_is_position_independent |
|
|| should_force_pic_veneer) |
|
? arm_stub_long_branch_thumb_only_pic // PIC stub. |
|
: arm_stub_long_branch_thumb_only; // non-PIC stub. |
|
} |
|
} |
|
else |
|
{ |
|
// Thumb to arm. |
|
|
|
// FIXME: We should check that the input section is from an |
|
// object that has interwork enabled. |
|
|
|
stub_type = (output_is_position_independent |
|
|| should_force_pic_veneer) |
|
// PIC stubs. |
|
? ((may_use_blx |
|
&& (r_type == elfcpp::R_ARM_THM_CALL)) |
|
? arm_stub_long_branch_any_arm_pic // V5T and above. |
|
: arm_stub_long_branch_v4t_thumb_arm_pic) // V4T. |
|
|
|
// non-PIC stubs. |
|
: ((may_use_blx |
|
&& (r_type == elfcpp::R_ARM_THM_CALL)) |
|
? arm_stub_long_branch_any_any // V5T and above. |
|
: arm_stub_long_branch_v4t_thumb_arm); // V4T. |
|
|
|
// Handle v4t short branches. |
|
if ((stub_type == arm_stub_long_branch_v4t_thumb_arm) |
|
&& (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET) |
|
&& (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET)) |
|
stub_type = arm_stub_short_branch_v4t_thumb_arm; |
|
} |
|
} |
|
} |
|
else if (r_type == elfcpp::R_ARM_CALL |
|
|| r_type == elfcpp::R_ARM_JUMP24 |
|
|| r_type == elfcpp::R_ARM_PLT32) |
|
{ |
|
branch_offset = static_cast<int64_t>(destination) - location; |
|
if (target_is_thumb) |
|
{ |
|
// Arm to thumb. |
|
|
|
// FIXME: We should check that the input section is from an |
|
// object that has interwork enabled. |
|
|
|
// We have an extra 2-bytes reach because of |
|
// the mode change (bit 24 (H) of BLX encoding). |
|
if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2) |
|
|| (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET) |
|
|| ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx) |
|
|| (r_type == elfcpp::R_ARM_JUMP24) |
|
|| (r_type == elfcpp::R_ARM_PLT32)) |
|
{ |
|
stub_type = (output_is_position_independent |
|
|| should_force_pic_veneer) |
|
// PIC stubs. |
|
? (may_use_blx |
|
? arm_stub_long_branch_any_thumb_pic// V5T and above. |
|
: arm_stub_long_branch_v4t_arm_thumb_pic) // V4T stub. |
|
|
|
// non-PIC stubs. |
|
: (may_use_blx |
|
? arm_stub_long_branch_any_any // V5T and above. |
|
: arm_stub_long_branch_v4t_arm_thumb); // V4T. |
|
} |
|
} |
|
else |
|
{ |
|
// Arm to arm. |
|
if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET |
|
|| (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)) |
|
{ |
|
stub_type = (output_is_position_independent |
|
|| should_force_pic_veneer) |
|
? arm_stub_long_branch_any_arm_pic // PIC stubs. |
|
: arm_stub_long_branch_any_any; /// non-PIC. |
|
} |
|
} |
|
} |
|
|
|
return stub_type; |
|
} |
|
|
|
// Cortex_a8_stub methods. |
|
|
|
// Return the instruction for a THUMB16_SPECIAL_TYPE instruction template. |
|
// I is the position of the instruction template in the stub template. |
|
|
|
uint16_t |
|
Cortex_a8_stub::do_thumb16_special(size_t i) |
|
{ |
|
// The only use of this is to copy condition code from a conditional |
|
// branch being worked around to the corresponding conditional branch in |
|
// to the stub. |
|
gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond |
|
&& i == 0); |
|
uint16_t data = this->stub_template()->insns()[i].data(); |
|
gold_assert((data & 0xff00U) == 0xd000U); |
|
data |= ((this->original_insn_ >> 22) & 0xf) << 8; |
|
return data; |
|
} |
|
|
|
// Stub_factory methods. |
|
|
|
Stub_factory::Stub_factory() |
|
{ |
|
// The instruction template sequences are declared as static |
|
// objects and initialized first time the constructor runs. |
|
|
|
// Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx |
|
// to reach the stub if necessary. |
|
static const Insn_template elf32_arm_stub_long_branch_any_any[] = |
|
{ |
|
Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4] |
|
Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0), |
|
// dcd R_ARM_ABS32(X) |
|
}; |
|
|
|
// V4T Arm -> Thumb long branch stub. Used on V4T where blx is not |
|
// available. |
|
static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] = |
|
{ |
|
Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0] |
|
Insn_template::arm_insn(0xe12fff1c), // bx ip |
|
Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0), |
|
// dcd R_ARM_ABS32(X) |
|
}; |
|
|
|
// Thumb -> Thumb long branch stub. Used on M-profile architectures. |
|
static const Insn_template elf32_arm_stub_long_branch_thumb_only[] = |
|
{ |
|
Insn_template::thumb16_insn(0xb401), // push {r0} |
|
Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8] |
|
Insn_template::thumb16_insn(0x4684), // mov ip, r0 |
|
Insn_template::thumb16_insn(0xbc01), // pop {r0} |
|
Insn_template::thumb16_insn(0x4760), // bx ip |
|
Insn_template::thumb16_insn(0xbf00), // nop |
|
Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0), |
|
// dcd R_ARM_ABS32(X) |
|
}; |
|
|
|
// V4T Thumb -> Thumb long branch stub. Using the stack is not |
|
// allowed. |
|
static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] = |
|
{ |
|
Insn_template::thumb16_insn(0x4778), // bx pc |
|
Insn_template::thumb16_insn(0x46c0), // nop |
|
Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0] |
|
Insn_template::arm_insn(0xe12fff1c), // bx ip |
|
Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0), |
|
// dcd R_ARM_ABS32(X) |
|
}; |
|
|
|
// V4T Thumb -> ARM long branch stub. Used on V4T where blx is not |
|
// available. |
|
static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] = |
|
{ |
|
Insn_template::thumb16_insn(0x4778), // bx pc |
|
Insn_template::thumb16_insn(0x46c0), // nop |
|
Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4] |
|
Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0), |
|
// dcd R_ARM_ABS32(X) |
|
}; |
|
|
|
// V4T Thumb -> ARM short branch stub. Shorter variant of the above |
|
// one, when the destination is close enough. |
|
static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] = |
|
{ |
|
Insn_template::thumb16_insn(0x4778), // bx pc |
|
Insn_template::thumb16_insn(0x46c0), // nop |
|
Insn_template::arm_rel_insn(0xea000000, -8), // b (X-8) |
|
}; |
|
|
|
// ARM/Thumb -> ARM long branch stub, PIC. On V5T and above, use |
|
// blx to reach the stub if necessary. |
|
static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] = |
|
{ |
|
Insn_template::arm_insn(0xe59fc000), // ldr r12, [pc] |
|
Insn_template::arm_insn(0xe08ff00c), // add pc, pc, ip |
|
Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4), |
|
// dcd R_ARM_REL32(X-4) |
|
}; |
|
|
|
// ARM/Thumb -> Thumb long branch stub, PIC. On V5T and above, use |
|
// blx to reach the stub if necessary. We can not add into pc; |
|
// it is not guaranteed to mode switch (different in ARMv6 and |
|
// ARMv7). |
|
static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] = |
|
{ |
|
Insn_template::arm_insn(0xe59fc004), // ldr r12, [pc, #4] |
|
Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip |
|
Insn_template::arm_insn(0xe12fff1c), // bx ip |
|
Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0), |
|
// dcd R_ARM_REL32(X) |
|
}; |
|
|
|
// V4T ARM -> ARM long branch stub, PIC. |
|
static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] = |
|
{ |
|
Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4] |
|
Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip |
|
Insn_template::arm_insn(0xe12fff1c), // bx ip |
|
Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0), |
|
// dcd R_ARM_REL32(X) |
|
}; |
|
|
|
// V4T Thumb -> ARM long branch stub, PIC. |
|
static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] = |
|
{ |
|
Insn_template::thumb16_insn(0x4778), // bx pc |
|
Insn_template::thumb16_insn(0x46c0), // nop |
|
Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0] |
|
Insn_template::arm_insn(0xe08cf00f), // add pc, ip, pc |
|
Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4), |
|
// dcd R_ARM_REL32(X) |
|
}; |
|
|
|
// Thumb -> Thumb long branch stub, PIC. Used on M-profile |
|
// architectures. |
|
static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] = |
|
{ |
|
Insn_template::thumb16_insn(0xb401), // push {r0} |
|
Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8] |
|
Insn_template::thumb16_insn(0x46fc), // mov ip, pc |
|
Insn_template::thumb16_insn(0x4484), // add ip, r0 |
|
Insn_template::thumb16_insn(0xbc01), // pop {r0} |
|
Insn_template::thumb16_insn(0x4760), // bx ip |
|
Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4), |
|
// dcd R_ARM_REL32(X) |
|
}; |
|
|
|
// V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not |
|
// allowed. |
|
static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] = |
|
{ |
|
Insn_template::thumb16_insn(0x4778), // bx pc |
|
Insn_template::thumb16_insn(0x46c0), // nop |
|
Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4] |
|
Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip |
|
Insn_template::arm_insn(0xe12fff1c), // bx ip |
|
Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0), |
|
// dcd R_ARM_REL32(X) |
|
}; |
|
|
|
// Cortex-A8 erratum-workaround stubs. |
|
|
|
// Stub used for conditional branches (which may be beyond +/-1MB away, |
|
// so we can't use a conditional branch to reach this stub). |
|
|
|
// original code: |
|
// |
|
// b<cond> X |
|
// after: |
|
// |
|
static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] = |
|
{ |
|
Insn_template::thumb16_bcond_insn(0xd001), // b<cond>.n true |
|
Insn_template::thumb32_b_insn(0xf000b800, -4), // b.w after |
|
Insn_template::thumb32_b_insn(0xf000b800, -4) // true: |
|
// b.w X |
|
}; |
|
|
|
// Stub used for b.w and bl.w instructions. |
|
|
|
static const Insn_template elf32_arm_stub_a8_veneer_b[] = |
|
{ |
|
Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest |
|
}; |
|
|
|
static const Insn_template elf32_arm_stub_a8_veneer_bl[] = |
|
{ |
|
Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest |
|
}; |
|
|
|
// Stub used for Thumb-2 blx.w instructions. We modified the original blx.w |
|
// instruction (which switches to ARM mode) to point to this stub. Jump to |
|
// the real destination using an ARM-mode branch. |
|
static const Insn_template elf32_arm_stub_a8_veneer_blx[] = |
|
{ |
|
Insn_template::arm_rel_insn(0xea000000, -8) // b dest |
|
}; |
|
|
|
// Stub used to provide an interworking for R_ARM_V4BX relocation |
|
// (bx r[n] instruction). |
|
static const Insn_template elf32_arm_stub_v4_veneer_bx[] = |
|
{ |
|
Insn_template::arm_insn(0xe3100001), // tst r<n>, #1 |
|
Insn_template::arm_insn(0x01a0f000), // moveq pc, r<n> |
|
Insn_template::arm_insn(0xe12fff10) // bx r<n> |
|
}; |
|
|
|
// Fill in the stub template look-up table. Stub templates are constructed |
|
// per instance of Stub_factory for fast look-up without locking |
|
// in a thread-enabled environment. |
|
|
|
this->stub_templates_[arm_stub_none] = |
|
new Stub_template(arm_stub_none, NULL, 0); |
|
|
|
#define DEF_STUB(x) \ |
|
do \ |
|
{ \ |
|
size_t array_size \ |
|
= sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \ |
|
Stub_type type = arm_stub_##x; \ |
|
this->stub_templates_[type] = \ |
|
new Stub_template(type, elf32_arm_stub_##x, array_size); \ |
|
} \ |
|
while (0); |
|
|
|
DEF_STUBS |
|
#undef DEF_STUB |
|
} |
|
|
|
// Stub_table methods. |
|
|
|
// Remove all Cortex-A8 stub. |
|
|
|
template<bool big_endian> |
|
void |
|
Stub_table<big_endian>::remove_all_cortex_a8_stubs() |
|
{ |
|
for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin(); |
|
p != this->cortex_a8_stubs_.end(); |
|
++p) |
|
delete p->second; |
|
this->cortex_a8_stubs_.clear(); |
|
} |
|
|
|
// Relocate one stub. This is a helper for Stub_table::relocate_stubs(). |
|
|
|
template<bool big_endian> |
|
void |
|
Stub_table<big_endian>::relocate_stub( |
|
Stub* stub, |
|
const Relocate_info<32, big_endian>* relinfo, |
|
Target_arm<big_endian>* arm_target, |
|
Output_section* output_section, |
|
unsigned char* view, |
|
Arm_address address, |
|
section_size_type view_size) |
|
{ |
|
const Stub_template* stub_template = stub->stub_template(); |
|
if (stub_template->reloc_count() != 0) |
|
{ |
|
// Adjust view to cover the stub only. |
|
section_size_type offset = stub->offset(); |
|
section_size_type stub_size = stub_template->size(); |
|
gold_assert(offset + stub_size <= view_size); |
|
|
|
arm_target->relocate_stub(stub, relinfo, output_section, view + offset, |
|
address + offset, stub_size); |
|
} |
|
} |
|
|
|
// Relocate all stubs in this stub table. |
|
|
|
template<bool big_endian> |
|
void |
|
Stub_table<big_endian>::relocate_stubs( |
|
const Relocate_info<32, big_endian>* relinfo, |
|
Target_arm<big_endian>* arm_target, |
|
Output_section* output_section, |
|
unsigned char* view, |
|
Arm_address address, |
|
section_size_type view_size) |
|
{ |
|
// If we are passed a view bigger than the stub table's. we need to |
|
// adjust the view. |
|
gold_assert(address == this->address() |
|
&& (view_size |
|
== static_cast<section_size_type>(this->data_size()))); |
|
|
|
// Relocate all relocation stubs. |
|
for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin(); |
|
p != this->reloc_stubs_.end(); |
|
++p) |
|
this->relocate_stub(p->second, relinfo, arm_target, output_section, view, |
|
address, view_size); |
|
|
|
// Relocate all Cortex-A8 stubs. |
|
for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin(); |
|
p != this->cortex_a8_stubs_.end(); |
|
++p) |
|
this->relocate_stub(p->second, relinfo, arm_target, output_section, view, |
|
address, view_size); |
|
|
|
// Relocate all ARM V4BX stubs. |
|
for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin(); |
|
p != this->arm_v4bx_stubs_.end(); |
|
++p) |
|
{ |
|
if (*p != NULL) |
|
this->relocate_stub(*p, relinfo, arm_target, output_section, view, |
|
address, view_size); |
|
} |
|
} |
|
|
|
// Write out the stubs to file. |
|
|
|
template<bool big_endian> |
|
void |
|
Stub_table<big_endian>::do_write(Output_file* of) |
|
{ |
|
off_t offset = this->offset(); |
|
const section_size_type oview_size = |
|
convert_to_section_size_type(this->data_size()); |
|
unsigned char* const oview = of->get_output_view(offset, oview_size); |
|
|
|
// Write relocation stubs. |
|
for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin(); |
|
p != this->reloc_stubs_.end(); |
|
++p) |
|
{ |
|
Reloc_stub* stub = p->second; |
|
Arm_address address = this->address() + stub->offset(); |
|
gold_assert(address |
|
== align_address(address, |
|
stub->stub_template()->alignment())); |
|
stub->write(oview + stub->offset(), stub->stub_template()->size(), |
|
big_endian); |
|
} |
|
|
|
// Write Cortex-A8 stubs. |
|
for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin(); |
|
p != this->cortex_a8_stubs_.end(); |
|
++p) |
|
{ |
|
Cortex_a8_stub* stub = p->second; |
|
Arm_address address = this->address() + stub->offset(); |
|
gold_assert(address |
|
== align_address(address, |
|
stub->stub_template()->alignment())); |
|
stub->write(oview + stub->offset(), stub->stub_template()->size(), |
|
big_endian); |
|
} |
|
|
|
// Write ARM V4BX relocation stubs. |
|
for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin(); |
|
p != this->arm_v4bx_stubs_.end(); |
|
++p) |
|
{ |
|
if (*p == NULL) |
|
continue; |
|
|
|
Arm_address address = this->address() + (*p)->offset(); |
|
gold_assert(address |
|
== align_address(address, |
|
(*p)->stub_template()->alignment())); |
|
(*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(), |
|
big_endian); |
|
} |
|
|
|
if (parameters->options().stub_group_auto_padding()) |
|
{ |
|
// Zero-fill padding area. |
|
gold_assert((unsigned int)(this->prev_data_size_ + this->padding_) <= oview_size); |
|
unsigned char* p_padding_area = oview + this->prev_data_size_; |
|
for (unsigned int i = 0; i < this->padding_; ++i) |
|
*(p_padding_area + i) = 0; |
|
} |
|
|
|
of->write_output_view(this->offset(), oview_size, oview); |
|
} |
|
|
|
// Update the data size and address alignment of the stub table at the end |
|
// of a relaxation pass. Return true if either the data size or the |
|
// alignment changed in this relaxation pass. |
|
|
|
template<bool big_endian> |
|
bool |
|
Stub_table<big_endian>::update_data_size_and_addralign() |
|
{ |
|
// Go over all stubs in table to compute data size and address alignment. |
|
off_t size = this->reloc_stubs_size_; |
|
unsigned addralign = this->reloc_stubs_addralign_; |
|
|
|
for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin(); |
|
p != this->cortex_a8_stubs_.end(); |
|
++p) |
|
{ |
|
const Stub_template* stub_template = p->second->stub_template(); |
|
addralign = std::max(addralign, stub_template->alignment()); |
|
size = (align_address(size, stub_template->alignment()) |
|
+ stub_template->size()); |
|
} |
|
|
|
for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin(); |
|
p != this->arm_v4bx_stubs_.end(); |
|
++p) |
|
{ |
|
if (*p == NULL) |
|
continue; |
|
|
|
const Stub_template* stub_template = (*p)->stub_template(); |
|
addralign = std::max(addralign, stub_template->alignment()); |
|
size = (align_address(size, stub_template->alignment()) |
|
+ stub_template->size()); |
|
} |
|
|
|
unsigned int prev_padding = this->padding_; |
|
|
|
// Smart padding. |
|
if (parameters->options().stub_group_auto_padding()) |
|
{ |
|
if(size > this->prev_data_size_) |
|
{ |
|
// Stub table has to grow 'delta' bytes. |
|
unsigned int delta = size - this->prev_data_size_; |
|
// Test to see if this delta grow could be "absorbed" by the |
|
// "padding_" we added in previously iteration. |
|
if (delta <= this->padding_) |
|
{ |
|
// Yes! Grow into padding area, shrink padding, keep stub table |
|
// size unchanged. |
|
this->padding_ -= delta; |
|
} |
|
else |
|
{ |
|
// No! Delta is too much to fit in padding area. Heuristically, we |
|
// increase padding. Padding is about 0.5% of huge increment, or |
|
// 2% of moderate increment, or 0% for smaller ones.. |
|
if (delta >= 0x50000) |
|
this->padding_ = 0x250; |
|
else if (delta >= 0x30000) |
|
this->padding_ = 0x150; |
|
else if (delta >= 0x10000) |
|
this->padding_ = 0x100; |
|
else if (delta >= 0x500) |
|
{ |
|
// Set padding to 2% of stub table growth delta or 0x40, |
|
// whichever is smaller. |
|
this->padding_ = std::min((unsigned int)(delta * 0.02), |
|
(unsigned int)0x40); |
|
} |
|
} |
|
} |
|
else if (size < this->prev_data_size_) |
|
{ |
|
// Stub table shrinks, this is rare, but not impossible. |
|
unsigned int delta = this->prev_data_size_ - size; |
|
// So let padding increase to absorb the shrinking. Still we get an |
|
// unchanged stub table. |
|
this->padding_ += delta; |
|
} |
|
} |
|
|
|
// Check if either data size or alignment changed in this pass. |
|
// Update prev_data_size_ and prev_addralign_. These will be used |
|
// as the current data size and address alignment for the next pass. |
|
bool changed = (size + this->padding_) != |
|
this->prev_data_size_ + prev_padding; |
|
|
|
this->prev_data_size_ = size; |
|
|
|
if (addralign != this->prev_addralign_) |
|
changed = true; |
|
this->prev_addralign_ = addralign; |
|
|
|
return changed; |
|
} |
|
|
|
// Finalize the stubs. This sets the offsets of the stubs within the stub |
|
// table. It also marks all input sections needing Cortex-A8 workaround. |
|
|
|
template<bool big_endian> |
|
void |
|
Stub_table<big_endian>::finalize_stubs() |
|
{ |
|
off_t off = this->reloc_stubs_size_; |
|
for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin(); |
|
p != this->cortex_a8_stubs_.end(); |
|
++p) |
|
{ |
|
Cortex_a8_stub* stub = p->second; |
|
const Stub_template* stub_template = stub->stub_template(); |
|
uint64_t stub_addralign = stub_template->alignment(); |
|
off = align_address(off, stub_addralign); |
|
stub->set_offset(off); |
|
off += stub_template->size(); |
|
|
|
// Mark input section so that we can determine later if a code section |
|
// needs the Cortex-A8 workaround quickly. |
|
Arm_relobj<big_endian>* arm_relobj = |
|
Arm_relobj<big_endian>::as_arm_relobj(stub->relobj()); |
|
arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx()); |
|
} |
|
|
|
for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin(); |
|
p != this->arm_v4bx_stubs_.end(); |
|
++p) |
|
{ |
|
if (*p == NULL) |
|
continue; |
|
|
|
const Stub_template* stub_template = (*p)->stub_template(); |
|
uint64_t stub_addralign = stub_template->alignment(); |
|
off = align_address(off, stub_addralign); |
|
(*p)->set_offset(off); |
|
off += stub_template->size(); |
|
} |
|
|
|
gold_assert(off <= this->prev_data_size_); |
|
} |
|
|
|
// Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS |
|
// and VIEW_ADDRESS + VIEW_SIZE - 1. VIEW points to the mapped address |
|
// of the address range seen by the linker. |
|
|
|
template<bool big_endian> |
|
void |
|
Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range( |
|
Target_arm<big_endian>* arm_target, |
|
unsigned char* view, |
|
Arm_address view_address, |
|
section_size_type view_size) |
|
{ |
|
// Cortex-A8 stubs are sorted by addresses of branches being fixed up. |
|
for (Cortex_a8_stub_list::const_iterator p = |
|
this->cortex_a8_stubs_.lower_bound(view_address); |
|
((p != this->cortex_a8_stubs_.end()) |
|
&& (p->first < (view_address + view_size))); |
|
++p) |
|
{ |
|
// We do not store the THUMB bit in the LSB of either the branch address |
|
// or the stub offset. There is no need to strip the LSB. |
|
Arm_address branch_address = p->first; |
|
const Cortex_a8_stub* stub = p->second; |
|
Arm_address stub_address = this->address() + stub->offset(); |
|
|
|
// Offset of the branch instruction relative to this view. |
|
section_size_type offset = |
|
convert_to_section_size_type(branch_address - view_address); |
|
gold_assert((offset + 4) <= view_size); |
|
|
|
arm_target->apply_cortex_a8_workaround(stub, stub_address, |
|
view + offset, branch_address); |
|
} |
|
} |
|
|
|
// Arm_input_section methods. |
|
|
|
// Initialize an Arm_input_section. |
|
|
|
template<bool big_endian> |
|
void |
|
Arm_input_section<big_endian>::init() |
|
{ |
|
Relobj* relobj = this->relobj(); |
|
unsigned int shndx = this->shndx(); |
|
|
|
// We have to cache original size, alignment and contents to avoid locking |
|
// the original file. |
|
this->original_addralign_ = |
|
convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx)); |
|
|
|
// This is not efficient but we expect only a small number of relaxed |
|
// input sections for stubs. |
|
section_size_type section_size; |
|
const unsigned char* section_contents = |
|
relobj->section_contents(shndx, §ion_size, false); |
|
this->original_size_ = |
|
convert_types<uint32_t, uint64_t>(relobj->section_size(shndx)); |
|
|
|
gold_assert(this->original_contents_ == NULL); |
|
this->original_contents_ = new unsigned char[section_size]; |
|
memcpy(this->original_contents_, section_contents, section_size); |
|
|
|
// We want to make this look like the original input section after |
|
// output sections are finalized. |
|
Output_section* os = relobj->output_section(shndx); |
|
off_t offset = relobj->output_section_offset(shndx); |
|
gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx)); |
|
this->set_address(os->address() + offset); |
|
this->set_file_offset(os->offset() + offset); |
|
|
|
this->set_current_data_size(this->original_size_); |
|
this->finalize_data_size(); |
|
} |
|
|
|
template<bool big_endian> |
|
void |
|
Arm_input_section<big_endian>::do_write(Output_file* of) |
|
{ |
|
// We have to write out the original section content. |
|
gold_assert(this->original_contents_ != NULL); |
|
of->write(this->offset(), this->original_contents_, |
|
this->original_size_); |
|
|
|
// If this owns a stub table and it is not empty, write it. |
|
if (this->is_stub_table_owner() && !this->stub_table_->empty()) |
|
this->stub_table_->write(of); |
|
} |
|
|
|
// Finalize data size. |
|
|
|
template<bool big_endian> |
|
void |
|
Arm_input_section<big_endian>::set_final_data_size() |
|
{ |
|
off_t off = convert_types<off_t, uint64_t>(this->original_size_); |
|
|
|
if (this->is_stub_table_owner()) |
|
{ |
|
this->stub_table_->finalize_data_size(); |
|
off = align_address(off, this->stub_table_->addralign()); |
|
off += this->stub_table_->data_size(); |
|
} |
|
this->set_data_size(off); |
|
} |
|
|
|
// Reset address and file offset. |
|
|
|
template<bool big_endian> |
|
void |
|
Arm_input_section<big_endian>::do_reset_address_and_file_offset() |
|
{ |
|
// Size of the original input section contents. |
|
off_t off = convert_types<off_t, uint64_t>(this->original_size_); |
|
|
|
// If this is a stub table owner, account for the stub table size. |
|
if (this->is_stub_table_owner()) |
|
{ |
|
Stub_table<big_endian>* stub_table = this->stub_table_; |
|
|
|
// Reset the stub table's address and file offset. The |
|
// current data size for child will be updated after that. |
|
stub_table_->reset_address_and_file_offset(); |
|
off = align_address(off, stub_table_->addralign()); |
|
off += stub_table->current_data_size(); |
|
} |
|
|
|
this->set_current_data_size(off); |
|
} |
|
|
|
// Arm_exidx_cantunwind methods. |
|
|
|
// Write this to Output file OF for a fixed endianness. |
|
|
|
template<bool big_endian> |
|
void |
|
Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of) |
|
{ |
|
off_t offset = this->offset(); |
|
const section_size_type oview_size = 8; |
|
unsigned char* const oview = of->get_output_view(offset, oview_size); |
|
|
|
Output_section* os = this->relobj_->output_section(this->shndx_); |
|
gold_assert(os != NULL); |
|
|
|
Arm_relobj<big_endian>* arm_relobj = |
|
Arm_relobj<big_endian>::as_arm_relobj(this->relobj_); |
|
Arm_address output_offset = |
|
arm_relobj->get_output_section_offset(this->shndx_); |
|
Arm_address section_start; |
|
section_size_type section_size; |
|
|
|
// Find out the end of the text section referred by this. |
|
if (output_offset != Arm_relobj<big_endian>::invalid_address) |
|
{ |
|
section_start = os->address() + output_offset; |
|
const Arm_exidx_input_section* exidx_input_section = |
|
arm_relobj->exidx_input_section_by_link(this->shndx_); |
|
gold_assert(exidx_input_section != NULL); |
|
section_size = |
|
convert_to_section_size_type(exidx_input_section->text_size()); |
|
} |
|
else |
|
{ |
|
// Currently this only happens for a relaxed section. |
|
const Output_relaxed_input_section* poris = |
|
os->find_relaxed_input_section(this->relobj_, this->shndx_); |
|
gold_assert(poris != NULL); |
|
section_start = poris->address(); |
|
section_size = convert_to_section_size_type(poris->data_size()); |
|
} |
|
|
|
// We always append this to the end of an EXIDX section. |
|
Arm_address output_address = section_start + section_size; |
|
|
|
// Write out the entry. The first word either points to the beginning |
|
// or after the end of a text section. The second word is the special |
|
// EXIDX_CANTUNWIND value. |
|
uint32_t prel31_offset = output_address - this->address(); |
|
if (Bits<31>::has_overflow32(offset)) |
|
gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry")); |
|
elfcpp::Swap_unaligned<32, big_endian>::writeval(oview, |
|
prel31_offset & 0x7fffffffU); |
|
elfcpp::Swap_unaligned<32, big_endian>::writeval(oview + 4, |
|
elfcpp::EXIDX_CANTUNWIND); |
|
|
|
of->write_output_view(this->offset(), oview_size, oview); |
|
} |
|
|
|
// Arm_exidx_merged_section methods. |
|
|
|
// Constructor for Arm_exidx_merged_section. |
|
// EXIDX_INPUT_SECTION points to the unmodified EXIDX input section. |
|
// SECTION_OFFSET_MAP points to a section offset map describing how |
|
// parts of the input section are mapped to output. DELETED_BYTES is |
|
// the number of bytes deleted from the EXIDX input section. |
|
|
|
Arm_exidx_merged_section::Arm_exidx_merged_section( |
|
const Arm_exidx_input_section& exidx_input_section, |
|
const Arm_exidx_section_offset_map& section_offset_map, |
|
uint32_t deleted_bytes) |
|
: Output_relaxed_input_section(exidx_input_section.relobj(), |
|
exidx_input_section.shndx(), |
|
exidx_input_section.addralign()), |
|
exidx_input_section_(exidx_input_section), |
|
section_offset_map_(section_offset_map) |
|
{ |
|
// If we retain or discard the whole EXIDX input section, we would |
|
// not be here. |
|
gold_assert(deleted_bytes != 0 |
|
&& deleted_bytes != this->exidx_input_section_.size()); |
|
|
|
// Fix size here so that we do not need to implement set_final_data_size. |
|
uint32_t size = exidx_input_section.size() - deleted_bytes; |
|
this->set_data_size(size); |
|
this->fix_data_size(); |
|
|
|
// Allocate buffer for section contents and build contents. |
|
this->section_contents_ = new unsigned char[size]; |
|
} |
|
|
|
// Build the contents of a merged EXIDX output section. |
|
|
|
void |
|
Arm_exidx_merged_section::build_contents( |
|
const unsigned char* original_contents, |
|
section_size_type original_size) |
|
{ |
|
// Go over spans of input offsets and write only those that are not |
|
// discarded. |
|
section_offset_type in_start = 0; |
|
section_offset_type out_start = 0; |
|
section_offset_type in_max = |
|
convert_types<section_offset_type>(original_size); |
|
section_offset_type out_max = |
|
convert_types<section_offset_type>(this->data_size()); |
|
for (Arm_exidx_section_offset_map::const_iterator p = |
|
this->section_offset_map_.begin(); |
|
p != this->section_offset_map_.end(); |
|
++p) |
|
{ |
|
section_offset_type in_end = p->first; |
|
gold_assert(in_end >= in_start); |
|
section_offset_type out_end = p->second; |
|
size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1); |
|
if (out_end != -1) |
|
{ |
|
size_t out_chunk_size = |
|
convert_types<size_t>(out_end - out_start + 1); |
|
|
|
gold_assert(out_chunk_size == in_chunk_size |
|
&& in_end < in_max && out_end < out_max); |
|
|
|
memcpy(this->section_contents_ + out_start, |
|
original_contents + in_start, |
|
out_chunk_size); |
|
out_start += out_chunk_size; |
|
} |
|
in_start += in_chunk_size; |
|
} |
|
} |
|
|
|
// Given an input OBJECT, an input section index SHNDX within that |
|
// object, and an OFFSET relative to the start of that input |
|
// section, return whether or not the corresponding offset within |
|
// the output section is known. If this function returns true, it |
|
// sets *POUTPUT to the output offset. The value -1 indicates that |
|
// this input offset is being discarded. |
|
|
|
bool |
|
Arm_exidx_merged_section::do_output_offset( |
|
const Relobj* relobj, |
|
unsigned int shndx, |
|
section_offset_type offset, |
|
section_offset_type* poutput) const |
|
{ |
|
// We only handle offsets for the original EXIDX input section. |
|
if (relobj != this->exidx_input_section_.relobj() |
|
|| shndx != this->exidx_input_section_.shndx()) |
|
return false; |
|
|
|
section_offset_type section_size = |
|
convert_types<section_offset_type>(this->exidx_input_section_.size()); |
|
if (offset < 0 || offset >= section_size) |
|
// Input offset is out of valid range. |
|
*poutput = -1; |
|
else |
|
{ |
|
// We need to look up the section offset map to determine the output |
|
// offset. Find the reference point in map that is first offset |
|
// bigger than or equal to this offset. |
|
Arm_exidx_section_offset_map::const_iterator p = |
|
this->section_offset_map_.lower_bound(offset); |
|
|
|
// The section offset maps are build such that this should not happen if |
|
// input offset is in the valid range. |
|
gold_assert(p != this->section_offset_map_.end()); |
|
|
|
// We need to check if this is dropped. |
|
section_offset_type ref = p->first; |
|
section_offset_type mapped_ref = p->second; |
|
|
|
if (mapped_ref != Arm_exidx_input_section::invalid_offset) |
|
// Offset is present in output. |
|
*poutput = mapped_ref + (offset - ref); |
|
else |
|
// Offset is discarded owing to EXIDX entry merging. |
|
*poutput = -1; |
|
} |
|
|
|
return true; |
|
} |
|
|
|
// Write this to output file OF. |
|
|
|
void |
|
Arm_exidx_merged_section::do_write(Output_file* of) |
|
{ |
|
off_t offset = this->offset(); |
|
const section_size_type oview_size = this->data_size(); |
|
unsigned char* const oview = of->get_output_view(offset, oview_size); |
|
|
|
Output_section* os = this->relobj()->output_section(this->shndx()); |
|
gold_assert(os != NULL); |
|
|
|
memcpy(oview, this->section_contents_, oview_size); |
|
of->write_output_view(this->offset(), oview_size, oview); |
|
} |
|
|
|
// Arm_exidx_fixup methods. |
|
|
|
// Append an EXIDX_CANTUNWIND in the current output section if the last entry |
|
// is not an EXIDX_CANTUNWIND entry already. The new EXIDX_CANTUNWIND entry |
|
// points to the end of the last seen EXIDX section. |
|
|
|
void |
|
Arm_exidx_fixup::add_exidx_cantunwind_as_needed() |
|
{ |
|
if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND |
|
&& this->last_input_section_ != NULL) |
|
{ |
|
Relobj* relobj = this->last_input_section_->relobj(); |
|
unsigned int text_shndx = this->last_input_section_->link(); |
|
Arm_exidx_cantunwind* cantunwind = |
|
new Arm_exidx_cantunwind(relobj, text_shndx); |
|
this->exidx_output_section_->add_output_section_data(cantunwind); |
|
this->last_unwind_type_ = UT_EXIDX_CANTUNWIND; |
|
} |
|
} |
|
|
|
// Process an EXIDX section entry in input. Return whether this entry |
|
// can be deleted in the output. SECOND_WORD in the second word of the |
|
// EXIDX entry. |
|
|
|
bool |
|
Arm_exidx_fixup::process_exidx_entry(uint32_t second_word) |
|
{ |
|
bool delete_entry; |
|
if (second_word == elfcpp::EXIDX_CANTUNWIND) |
|
{ |
|
// Merge if previous entry is also an EXIDX_CANTUNWIND. |
|
delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND; |
|
this->last_unwind_type_ = UT_EXIDX_CANTUNWIND; |
|
} |
|
else if ((second_word & 0x80000000) != 0) |
|
{ |
|
// Inlined unwinding data. Merge if equal to previous. |
|
delete_entry = (merge_exidx_entries_ |
|
&& this->last_unwind_type_ == UT_INLINED_ENTRY |
|
&& this->last_inlined_entry_ == second_word); |
|
this->last_unwind_type_ = UT_INLINED_ENTRY; |
|
this->last_inlined_entry_ = second_word; |
|
} |
|
else |
|
{ |
|
// Normal table entry. In theory we could merge these too, |
|
// but duplicate entries are likely to be much less common. |
|
delete_entry = false; |
|
this->last_unwind_type_ = UT_NORMAL_ENTRY; |
|
} |
|
return delete_entry; |
|
} |
|
|
|
// Update the current section offset map during EXIDX section fix-up. |
|
// If there is no map, create one. INPUT_OFFSET is the offset of a |
|
// reference point, DELETED_BYTES is the number of deleted by in the |
|
// section so far. If DELETE_ENTRY is true, the reference point and |
|
// all offsets after the previous reference point are discarded. |
|
|
|
void |
|
Arm_exidx_fixup::update_offset_map( |
|
section_offset_type input_offset, |
|
section_size_type deleted_bytes, |
|
bool delete_entry) |
|
{ |
|
if (this->section_offset_map_ == NULL) |
|
this->section_offset_map_ = new Arm_exidx_section_offset_map(); |
|
section_offset_type output_offset; |
|
if (delete_entry) |
|
output_offset = Arm_exidx_input_section::invalid_offset; |
|
else |
|
output_offset = input_offset - deleted_bytes; |
|
(*this->section_offset_map_)[input_offset] = output_offset; |
|
} |
|
|
|
// Process EXIDX_INPUT_SECTION for EXIDX entry merging. Return the number of |
|
// bytes deleted. SECTION_CONTENTS points to the contents of the EXIDX |
|
// section and SECTION_SIZE is the number of bytes pointed by SECTION_CONTENTS. |
|
// If some entries are merged, also store a pointer to a newly created |
|
// Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP. The caller |
|
// owns the map and is responsible for releasing it after use. |
|
|
|
template<bool big_endian> |
|
uint32_t |
|
Arm_exidx_fixup::process_exidx_section( |
|
const Arm_exidx_input_section* exidx_input_section, |
|
const unsigned char* section_contents, |
|
section_size_type section_size, |
|
Arm_exidx_section_offset_map** psection_offset_map) |
|
{ |
|
Relobj* relobj = exidx_input_section->relobj(); |
|
unsigned shndx = exidx_input_section->shndx(); |
|
|
|
if ((section_size % 8) != 0) |
|
{ |
|
// Something is wrong with this section. Better not touch it. |
|
gold_error(_("uneven .ARM.exidx section size in %s section %u"), |
|
relobj->name().c_str(), shndx); |
|
this->last_input_section_ = exidx_input_section; |
|
this->last_unwind_type_ = UT_NONE; |
|
return 0; |
|
} |
|
|
|
uint32_t deleted_bytes = 0; |
|
bool prev_delete_entry = false; |
|
gold_assert(this->section_offset_map_ == NULL); |
|
|
|
for (section_size_type i = 0; i < section_size; i += 8) |
|
{ |
|
typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
|
const Valtype* wv = |
|
reinterpret_cast<const Valtype*>(section_contents + i + 4); |
|
uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv); |
|
|
|
bool delete_entry = this->process_exidx_entry(second_word); |
|
|
|
// Entry deletion causes changes in output offsets. We use a std::map |
|
// to record these. And entry (x, y) means input offset x |
|
// is mapped to output offset y. If y is invalid_offset, then x is |
|
// dropped in the output. Because of the way std::map::lower_bound |
|
// works, we record the last offset in a region w.r.t to keeping or |
|
// dropping. If there is no entry (x0, y0) for an input offset x0, |
|
// the output offset y0 of it is determined by the output offset y1 of |
|
// the smallest input offset x1 > x0 that there is an (x1, y1) entry |
|
// in the map. If y1 is not -1, then y0 = y1 + x0 - x1. Otherwise, y1 |
|
// y0 is also -1. |
|
if (delete_entry != prev_delete_entry && i != 0) |
|
this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry); |
|
|
|
// Update total deleted bytes for this entry. |
|
if (delete_entry) |
|
deleted_bytes += 8; |
|
|
|
prev_delete_entry = delete_entry; |
|
} |
|
|
|
// If section offset map is not NULL, make an entry for the end of |
|
// section. |
|
if (this->section_offset_map_ != NULL) |
|
update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry); |
|
|
|
*psection_offset_map = this->section_offset_map_; |
|
this->section_offset_map_ = NULL; |
|
this->last_input_section_ = exidx_input_section; |
|
|
|
// Set the first output text section so that we can link the EXIDX output |
|
// section to it. Ignore any EXIDX input section that is completely merged. |
|
if (this->first_output_text_section_ == NULL |
|
&& deleted_bytes != section_size) |
|
{ |
|
unsigned int link = exidx_input_section->link(); |
|
Output_section* os = relobj->output_section(link); |
|
gold_assert(os != NULL); |
|
this->first_output_text_section_ = os; |
|
} |
|
|
|
return deleted_bytes; |
|
} |
|
|
|
// Arm_output_section methods. |
|
|
|
// Create a stub group for input sections from BEGIN to END. OWNER |
|
// points to the input section to be the owner a new stub table. |
|
|
|
template<bool big_endian> |
|
void |
|
Arm_output_section<big_endian>::create_stub_group( |
|
Input_section_list::const_iterator begin, |
|
Input_section_list::const_iterator end, |
|
Input_section_list::const_iterator owner, |
|
Target_arm<big_endian>* target, |
|
std::vector<Output_relaxed_input_section*>* new_relaxed_sections, |
|
const Task* task) |
|
{ |
|
// We use a different kind of relaxed section in an EXIDX section. |
|
// The static casting from Output_relaxed_input_section to |
|
// Arm_input_section is invalid in an EXIDX section. We are okay |
|
// because we should not be calling this for an EXIDX section. |
|
gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX); |
|
|
|
// Currently we convert ordinary input sections into relaxed sections only |
|
// at this point but we may want to support creating relaxed input section |
|
// very early. So we check here to see if owner is already a relaxed |
|
// section. |
|
|
|
Arm_input_section<big_endian>* arm_input_section; |
|
if (owner->is_relaxed_input_section()) |
|
{ |
|
arm_input_section = |
|
Arm_input_section<big_endian>::as_arm_input_section( |
|
owner->relaxed_input_section()); |
|
} |
|
else |
|
{ |
|
gold_assert(owner->is_input_section()); |
|
// Create a new relaxed input section. We need to lock the original |
|
// file. |
|
Task_lock_obj<Object> tl(task, owner->relobj()); |
|
arm_input_section = |
|
target->new_arm_input_section(owner->relobj(), owner->shndx()); |
|
new_relaxed_sections->push_back(arm_input_section); |
|
} |
|
|
|
// Create a stub table. |
|
Stub_table<big_endian>* stub_table = |
|
target->new_stub_table(arm_input_section); |
|
|
|
arm_input_section->set_stub_table(stub_table); |
|
|
|
Input_section_list::const_iterator p = begin; |
|
Input_section_list::const_iterator prev_p; |
|
|
|
// Look for input sections or relaxed input sections in [begin ... end]. |
|
do |
|
{ |
|
if (p->is_input_section() || p->is_relaxed_input_section()) |
|
{ |
|
// The stub table information for input sections live |
|
// in their objects. |
|
Arm_relobj<big_endian>* arm_relobj = |
|
Arm_relobj<big_endian>::as_arm_relobj(p->relobj()); |
|
arm_relobj->set_stub_table(p->shndx(), stub_table); |
|
} |
|
prev_p = p++; |
|
} |
|
while (prev_p != end); |
|
} |
|
|
|
// Group input sections for stub generation. GROUP_SIZE is roughly the limit |
|
// of stub groups. We grow a stub group by adding input section until the |
|
// size is just below GROUP_SIZE. The last input section will be converted |
|
// into a stub table. If STUB_ALWAYS_AFTER_BRANCH is false, we also add |
|
// input section after the stub table, effectively double the group size. |
|
// |
|
// This is similar to the group_sections() function in elf32-arm.c but is |
|
// implemented differently. |
|
|
|
template<bool big_endian> |
|
void |
|
Arm_output_section<big_endian>::group_sections( |
|
section_size_type group_size, |
|
bool stubs_always_after_branch, |
|
Target_arm<big_endian>* target, |
|
const Task* task) |
|
{ |
|
// States for grouping. |
|
typedef enum |
|
{ |
|
// No group is being built. |
|
NO_GROUP, |
|
// A group is being built but the stub table is not found yet. |
|
// We keep group a stub group until the size is just under GROUP_SIZE. |
|
// The last input section in the group will be used as the stub table. |
|
FINDING_STUB_SECTION, |
|
// A group is being built and we have already found a stub table. |
|
// We enter this state to grow a stub group by adding input section |
|
// after the stub table. This effectively doubles the group size. |
|
HAS_STUB_SECTION |
|
} State; |
|
|
|
// Any newly created relaxed sections are stored here. |
|
std::vector<Output_relaxed_input_section*> new_relaxed_sections; |
|
|
|
State state = NO_GROUP; |
|
section_size_type off = 0; |
|
section_size_type group_begin_offset = 0; |
|
section_size_type group_end_offset = 0; |
|
section_size_type stub_table_end_offset = 0; |
|
Input_section_list::const_iterator group_begin = |
|
this->input_sections().end(); |
|
Input_section_list::const_iterator stub_table = |
|
this->input_sections().end(); |
|
Input_section_list::const_iterator group_end = this->input_sections().end(); |
|
for (Input_section_list::const_iterator p = this->input_sections().begin(); |
|
p != this->input_sections().end(); |
|
++p) |
|
{ |
|
section_size_type section_begin_offset = |
|
align_address(off, p->addralign()); |
|
section_size_type section_end_offset = |
|
section_begin_offset + p->data_size(); |
|
|
|
// Check to see if we should group the previously seen sections. |
|
switch (state) |
|
{ |
|
case NO_GROUP: |
|
break; |
|
|
|
case FINDING_STUB_SECTION: |
|
// Adding this section makes the group larger than GROUP_SIZE. |
|
if (section_end_offset - group_begin_offset >= group_size) |
|
{ |
|
if (stubs_always_after_branch) |
|
{ |
|
gold_assert(group_end != this->input_sections().end()); |
|
this->create_stub_group(group_begin, group_end, group_end, |
|
target, &new_relaxed_sections, |
|
task); |
|
state = NO_GROUP; |
|
} |
|
else |
|
{ |
|
// But wait, there's more! Input sections up to |
|
// stub_group_size bytes after the stub table can be |
|
// handled by it too. |
|
state = HAS_STUB_SECTION; |
|
stub_table = group_end; |
|
stub_table_end_offset = group_end_offset; |
|
} |
|
} |
|
break; |
|
|
|
case HAS_STUB_SECTION: |
|
// Adding this section makes the post stub-section group larger |
|
// than GROUP_SIZE. |
|
if (section_end_offset - stub_table_end_offset >= group_size) |
|
{ |
|
gold_assert(group_end != this->input_sections().end()); |
|
this->create_stub_group(group_begin, group_end, stub_table, |
|
target, &new_relaxed_sections, task); |
|
state = NO_GROUP; |
|
} |
|
break; |
|
|
|
default: |
|
gold_unreachable(); |
|
} |
|
|
|
// If we see an input section and currently there is no group, start |
|
// a new one. Skip any empty sections. We look at the data size |
|
// instead of calling p->relobj()->section_size() to avoid locking. |
|
if ((p->is_input_section() || p->is_relaxed_input_section()) |
|
&& (p->data_size() != 0)) |
|
{ |
|
if (state == NO_GROUP) |
|
{ |
|
state = FINDING_STUB_SECTION; |
|
group_begin = p; |
|
group_begin_offset = section_begin_offset; |
|
} |
|
|
|
// Keep track of the last input section seen. |
|
group_end = p; |
|
group_end_offset = section_end_offset; |
|
} |
|
|
|
off = section_end_offset; |
|
} |
|
|
|
// Create a stub group for any ungrouped sections. |
|
if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION) |
|
{ |
|
gold_assert(group_end != this->input_sections().end()); |
|
this->create_stub_group(group_begin, group_end, |
|
(state == FINDING_STUB_SECTION |
|
? group_end |
|
: stub_table), |
|
target, &new_relaxed_sections, task); |
|
} |
|
|
|
// Convert input section into relaxed input section in a batch. |
|
if (!new_relaxed_sections.empty()) |
|
this->convert_input_sections_to_relaxed_sections(new_relaxed_sections); |
|
|
|
// Update the section offsets |
|
for (size_t i = 0; i < new_relaxed_sections.size(); ++i) |
|
{ |
|
Arm_relobj<big_endian>* arm_relobj = |
|
Arm_relobj<big_endian>::as_arm_relobj( |
|
new_relaxed_sections[i]->relobj()); |
|
unsigned int shndx = new_relaxed_sections[i]->shndx(); |
|
// Tell Arm_relobj that this input section is converted. |
|
arm_relobj->convert_input_section_to_relaxed_section(shndx); |
|
} |
|
} |
|
|
|
// Append non empty text sections in this to LIST in ascending |
|
// order of their position in this. |
|
|
|
template<bool big_endian> |
|
void |
|
Arm_output_section<big_endian>::append_text_sections_to_list( |
|
Text_section_list* list) |
|
{ |
|
gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0); |
|
|
|
for (Input_section_list::const_iterator p = this->input_sections().begin(); |
|
p != this->input_sections().end(); |
|
++p) |
|
{ |
|
// We only care about plain or relaxed input sections. We also |
|
// ignore any merged sections. |
|
if (p->is_input_section() || p->is_relaxed_input_section()) |
|
list->push_back(Text_section_list::value_type(p->relobj(), |
|
p->shndx())); |
|
} |
|
} |
|
|
|
template<bool big_endian> |
|
void |
|
Arm_output_section<big_endian>::fix_exidx_coverage( |
|
Layout* layout, |
|
const Text_section_list& sorted_text_sections, |
|
Symbol_table* symtab, |
|
bool merge_exidx_entries, |
|
const Task* task) |
|
{ |
|
// We should only do this for the EXIDX output section. |
|
gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX); |
|
|
|
// We don't want the relaxation loop to undo these changes, so we discard |
|
// the current saved states and take another one after the fix-up. |
|
this->discard_states(); |
|
|
|
// Remove all input sections. |
|
uint64_t address = this->address(); |
|
typedef std::list<Output_section::Input_section> Input_section_list; |
|
Input_section_list input_sections; |
|
this->reset_address_and_file_offset(); |
|
this->get_input_sections(address, std::string(""), &input_sections); |
|
|
|
if (!this->input_sections().empty()) |
|
gold_error(_("Found non-EXIDX input sections in EXIDX output section")); |
|
|
|
// Go through all the known input sections and record them. |
|
typedef Unordered_set<Section_id, Section_id_hash> Section_id_set; |
|
typedef Unordered_map<Section_id, const Output_section::Input_section*, |
|
Section_id_hash> Text_to_exidx_map; |
|
Text_to_exidx_map text_to_exidx_map; |
|
for (Input_section_list::const_iterator p = input_sections.begin(); |
|
p != input_sections.end(); |
|
++p) |
|
{ |
|
// This should never happen. At this point, we should only see |
|
// plain EXIDX input sections. |
|
gold_assert(!p->is_relaxed_input_section()); |
|
text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p); |
|
} |
|
|
|
Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries); |
|
|
|
// Go over the sorted text sections. |
|
typedef Unordered_set<Section_id, Section_id_hash> Section_id_set; |
|
Section_id_set processed_input_sections; |
|
for (Text_section_list::const_iterator p = sorted_text_sections.begin(); |
|
p != sorted_text_sections.end(); |
|
++p) |
|
{ |
|
Relobj* relobj = p->first; |
|
unsigned int shndx = p->second; |
|
|
|
Arm_relobj<big_endian>* arm_relobj = |
|
Arm_relobj<big_endian>::as_arm_relobj(relobj); |
|
const Arm_exidx_input_section* exidx_input_section = |
|
arm_relobj->exidx_input_section_by_link(shndx); |
|
|
|
// If this text section has no EXIDX section or if the EXIDX section |
|
// has errors, force an EXIDX_CANTUNWIND entry pointing to the end |
|
// of the last seen EXIDX section. |
|
if (exidx_input_section == NULL || exidx_input_section->has_errors()) |
|
{ |
|
exidx_fixup.add_exidx_cantunwind_as_needed(); |
|
continue; |
|
} |
|
|
|
Relobj* exidx_relobj = exidx_input_section->relobj(); |
|
unsigned int exidx_shndx = exidx_input_section->shndx(); |
|
Section_id sid(exidx_relobj, exidx_shndx); |
|
Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid); |
|
if (iter == text_to_exidx_map.end()) |
|
{ |
|
// This is odd. We have not seen this EXIDX input section before. |
|
// We cannot do fix-up. If we saw a SECTIONS clause in a script, |
|
// issue a warning instead. We assume the user knows what he |
|
// or she is doing. Otherwise, this is an error. |
|
if (layout->script_options()->saw_sections_clause()) |
|
gold_warning(_("unwinding may not work because EXIDX input section" |
|
" %u of %s is not in EXIDX output section"), |
|
exidx_shndx, exidx_relobj->name().c_str()); |
|
else |
|
gold_error(_("unwinding may not work because EXIDX input section" |
|
" %u of %s is not in EXIDX output section"), |
|
exidx_shndx, exidx_relobj->name().c_str()); |
|
|
|
exidx_fixup.add_exidx_cantunwind_as_needed(); |
|
continue; |
|
} |
|
|
|
// We need to access the contents of the EXIDX section, lock the |
|
// object here. |
|
Task_lock_obj<Object> tl(task, exidx_relobj); |
|
section_size_type exidx_size; |
|
const unsigned char* exidx_contents = |
|
exidx_relobj->section_contents(exidx_shndx, &exidx_size, false); |
|
|
|
// Fix up coverage and append input section to output data list. |
|
Arm_exidx_section_offset_map* section_offset_map = NULL; |
|
uint32_t deleted_bytes = |
|
exidx_fixup.process_exidx_section<big_endian>(exidx_input_section, |
|
exidx_contents, |
|
exidx_size, |
|
§ion_offset_map); |
|
|
|
if (deleted_bytes == exidx_input_section->size()) |
|
{ |
|
// The whole EXIDX section got merged. Remove it from output. |
|
gold_assert(section_offset_map == NULL); |
|
exidx_relobj->set_output_section(exidx_shndx, NULL); |
|
|
|
// All local symbols defined in this input section will be dropped. |
|
// We need to adjust output local symbol count. |
|
arm_relobj->set_output_local_symbol_count_needs_update(); |
|
} |
|
else if (deleted_bytes > 0) |
|
{ |
|
// Some entries are merged. We need to convert this EXIDX input |
|
// section into a relaxed section. |
|
gold_assert(section_offset_map != NULL); |
|
|
|
Arm_exidx_merged_section* merged_section = |
|
new Arm_exidx_merged_section(*exidx_input_section, |
|
*section_offset_map, deleted_bytes); |
|
merged_section->build_contents(exidx_contents, exidx_size); |
|
|
|
const std::string secname = exidx_relobj->section_name(exidx_shndx); |
|
this->add_relaxed_input_section(layout, merged_section, secname); |
|
arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx); |
|
|
|
// All local symbols defined in discarded portions of this input |
|
// section will be dropped. We need to adjust output local symbol |
|
// count. |
|
arm_relobj->set_output_local_symbol_count_needs_update(); |
|
} |
|
else |
|
{ |
|
// Just add back the EXIDX input section. |
|
gold_assert(section_offset_map == NULL); |
|
const Output_section::Input_section* pis = iter->second; |
|
gold_assert(pis->is_input_section()); |
|
this->add_script_input_section(*pis); |
|
} |
|
|
|
processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx)); |
|
} |
|
|
|
// Insert an EXIDX_CANTUNWIND entry at the end of output if necessary. |
|
exidx_fixup.add_exidx_cantunwind_as_needed(); |
|
|
|
// Remove any known EXIDX input sections that are not processed. |
|
for (Input_section_list::const_iterator p = input_sections.begin(); |
|
p != input_sections.end(); |
|
++p) |
|
{ |
|
if (processed_input_sections.find(Section_id(p->relobj(), p->shndx())) |
|
== processed_input_sections.end()) |
|
{ |
|
// We discard a known EXIDX section because its linked |
|
// text section has been folded by ICF. We also discard an |
|
// EXIDX section with error, the output does not matter in this |
|
// case. We do this to avoid triggering asserts. |
|
Arm_relobj<big_endian>* arm_relobj = |
|
Arm_relobj<big_endian>::as_arm_relobj(p->relobj()); |
|
const Arm_exidx_input_section* exidx_input_section = |
|
arm_relobj->exidx_input_section_by_shndx(p->shndx()); |
|
gold_assert(exidx_input_section != NULL); |
|
if (!exidx_input_section->has_errors()) |
|
{ |
|
unsigned int text_shndx = exidx_input_section->link(); |
|
gold_assert(symtab->is_section_folded(p->relobj(), text_shndx)); |
|
} |
|
|
|
// Remove this from link. We also need to recount the |
|
// local symbols. |
|
p->relobj()->set_output_section(p->shndx(), NULL); |
|
arm_relobj->set_output_local_symbol_count_needs_update(); |
|
} |
|
} |
|
|
|
// Link exidx output section to the first seen output section and |
|
// set correct entry size. |
|
this->set_link_section(exidx_fixup.first_output_text_section()); |
|
this->set_entsize(8); |
|
|
|
// Make changes permanent. |
|
this->save_states(); |
|
this->set_section_offsets_need_adjustment(); |
|
} |
|
|
|
// Link EXIDX output sections to text output sections. |
|
|
|
template<bool big_endian> |
|
void |
|
Arm_output_section<big_endian>::set_exidx_section_link() |
|
{ |
|
gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX); |
|
if (!this->input_sections().empty()) |
|
{ |
|
Input_section_list::const_iterator p = this->input_sections().begin(); |
|
Arm_relobj<big_endian>* arm_relobj = |
|
Arm_relobj<big_endian>::as_arm_relobj(p->relobj()); |
|
unsigned exidx_shndx = p->shndx(); |
|
const Arm_exidx_input_section* exidx_input_section = |
|
arm_relobj->exidx_input_section_by_shndx(exidx_shndx); |
|
gold_assert(exidx_input_section != NULL); |
|
unsigned int text_shndx = exidx_input_section->link(); |
|
Output_section* os = arm_relobj->output_section(text_shndx); |
|
this->set_link_section(os); |
|
} |
|
} |
|
|
|
// Arm_relobj methods. |
|
|
|
// Determine if an input section is scannable for stub processing. SHDR is |
|
// the header of the section and SHNDX is the section index. OS is the output |
|
// section for the input section and SYMTAB is the global symbol table used to |
|
// look up ICF information. |
|
|
|
template<bool big_endian> |
|
bool |
|
Arm_relobj<big_endian>::section_is_scannable( |
|
const elfcpp::Shdr<32, big_endian>& shdr, |
|
unsigned int shndx, |
|
const Output_section* os, |
|
const Symbol_table* symtab) |
|
{ |
|
// Skip any empty sections, unallocated sections or sections whose |
|
// type are not SHT_PROGBITS. |
|
if (shdr.get_sh_size() == 0 |
|
|| (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0 |
|
|| shdr.get_sh_type() != elfcpp::SHT_PROGBITS) |
|
return false; |
|
|
|
// Skip any discarded or ICF'ed sections. |
|
if (os == NULL || symtab->is_section_folded(this, shndx)) |
|
return false; |
|
|
|
// If this requires special offset handling, check to see if it is |
|
// a relaxed section. If this is not, then it is a merged section that |
|
// we cannot handle. |
|
if (this->is_output_section_offset_invalid(shndx)) |
|
{ |
|
const Output_relaxed_input_section* poris = |
|
os->find_relaxed_input_section(this, shndx); |
|
if (poris == NULL) |
|
return false; |
|
} |
|
|
|
return true; |
|
} |
|
|
|
// Determine if we want to scan the SHNDX-th section for relocation stubs. |
|
// This is a helper for Arm_relobj::scan_sections_for_stubs() below. |
|
|
|
template<bool big_endian> |
|
bool |
|
Arm_relobj<big_endian>::section_needs_reloc_stub_scanning( |
|
const elfcpp::Shdr<32, big_endian>& shdr, |
|
const Relobj::Output_sections& out_sections, |
|
const Symbol_table* symtab, |
|
const unsigned char* pshdrs) |
|
{ |
|
unsigned int sh_type = shdr.get_sh_type(); |
|
if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA) |
|
return false; |
|
|
|
// Ignore empty section. |
|
off_t sh_size = shdr.get_sh_size(); |
|
if (sh_size == 0) |
|
return false; |
|
|
|
// Ignore reloc section with unexpected symbol table. The |
|
// error will be reported in the final link. |
|
if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx()) |
|
return false; |
|
|
|
unsigned int reloc_size; |
|
if (sh_type == elfcpp::SHT_REL) |
|
reloc_size = elfcpp::Elf_sizes<32>::rel_size; |
|
else |
|
reloc_size = elfcpp::Elf_sizes<32>::rela_size; |
|
|
|
// Ignore reloc section with unexpected entsize or uneven size. |
|
// The error will be reported in the final link. |
|
if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0) |
|
return false; |
|
|
|
// Ignore reloc section with bad info. This error will be |
|
// reported in the final link. |
|
unsigned int index = this->adjust_shndx(shdr.get_sh_info()); |
|
if (index >= this->shnum()) |
|
return false; |
|
|
|
const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size; |
|
const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size); |
|
return this->section_is_scannable(text_shdr, index, |
|
out_sections[index], symtab); |
|
} |
|
|
|
// Return the output address of either a plain input section or a relaxed |
|
// input section. SHNDX is the section index. We define and use this |
|
// instead of calling Output_section::output_address because that is slow |
|
// for large output. |
|
|
|
template<bool big_endian> |
|
Arm_address |
|
Arm_relobj<big_endian>::simple_input_section_output_address( |
|
unsigned int shndx, |
|
Output_section* os) |
|
{ |
|
if (this->is_output_section_offset_invalid(shndx)) |
|
{ |
|
const Output_relaxed_input_section* poris = |
|
os->find_relaxed_input_section(this, shndx); |
|
// We do not handle merged sections here. |
|
gold_assert(poris != NULL); |
|
return poris->address(); |
|
} |
|
else |
|
return os->address() + this->get_output_section_offset(shndx); |
|
} |
|
|
|
// Determine if we want to scan the SHNDX-th section for non-relocation stubs. |
|
// This is a helper for Arm_relobj::scan_sections_for_stubs() below. |
|
|
|
template<bool big_endian> |
|
bool |
|
Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning( |
|
const elfcpp::Shdr<32, big_endian>& shdr, |
|
unsigned int shndx, |
|
Output_section* os, |
|
const Symbol_table* symtab) |
|
{ |
|
if (!this->section_is_scannable(shdr, shndx, os, symtab)) |
|
return false; |
|
|
|
// If the section does not cross any 4K-boundaries, it does not need to |
|
// be scanned. |
|
Arm_address address = this->simple_input_section_output_address(shndx, os); |
|
if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU)) |
|
return false; |
|
|
|
return true; |
|
} |
|
|
|
// Scan a section for Cortex-A8 workaround. |
|
|
|
template<bool big_endian> |
|
void |
|
Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum( |
|
const elfcpp::Shdr<32, big_endian>& shdr, |
|
unsigned int shndx, |
|
Output_section* os, |
|
Target_arm<big_endian>* arm_target) |
|
{ |
|
// Look for the first mapping symbol in this section. It should be |
|
// at (shndx, 0). |
|
Mapping_symbol_position section_start(shndx, 0); |
|
typename Mapping_symbols_info::const_iterator p = |
|
this->mapping_symbols_info_.lower_bound(section_start); |
|
|
|
// There are no mapping symbols for this section. Treat it as a data-only |
|
// section. |
|
if (p == this->mapping_symbols_info_.end() || p->first.first != shndx) |
|
return; |
|
|
|
Arm_address output_address = |
|
this->simple_input_section_output_address(shndx, os); |
|
|
|
// Get the section contents. |
|
section_size_type input_view_size = 0; |
|
const unsigned char* input_view = |
|
this->section_contents(shndx, &input_view_size, false); |
|
|
|
// We need to go through the mapping symbols to determine what to |
|
// scan. There are two reasons. First, we should look at THUMB code and |
|
// THUMB code only. Second, we only want to look at the 4K-page boundary |
|
// to speed up the scanning. |
|
|
|
while (p != this->mapping_symbols_info_.end() |
|
&& p->first.first == shndx) |
|
{ |
|
typename Mapping_symbols_info::const_iterator next = |
|
this->mapping_symbols_info_.upper_bound(p->first); |
|
|
|
// Only scan part of a section with THUMB code. |
|
if (p->second == 't') |
|
{ |
|
// Determine the end of this range. |
|
section_size_type span_start = |
|
convert_to_section_size_type(p->first.second); |
|
section_size_type span_end; |
|
if (next != this->mapping_symbols_info_.end() |
|
&& next->first.first == shndx) |
|
span_end = convert_to_section_size_type(next->first.second); |
|
else |
|
span_end = convert_to_section_size_type(shdr.get_sh_size()); |
|
|
|
if (((span_start + output_address) & ~0xfffUL) |
|
!= ((span_end + output_address - 1) & ~0xfffUL)) |
|
{ |
|
arm_target->scan_span_for_cortex_a8_erratum(this, shndx, |
|
span_start, span_end, |
|
input_view, |
|
output_address); |
|
} |
|
} |
|
|
|
p = next; |
|
} |
|
} |
|
|
|
// Scan relocations for stub generation. |
|
|
|
template<bool big_endian> |
|
void |
|
Arm_relobj<big_endian>::scan_sections_for_stubs( |
|
Target_arm<big_endian>* arm_target, |
|
const Symbol_table* symtab, |
|
const Layout* layout) |
|
{ |
|
unsigned int shnum = this->shnum(); |
|
const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size; |
|
|
|
// Read the section headers. |
|
const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(), |
|
shnum * shdr_size, |
|
true, true); |
|
|
|
// To speed up processing, we set up hash tables for fast lookup of |
|
// input offsets to output addresses. |
|
this->initialize_input_to_output_maps(); |
|
|
|
const Relobj::Output_sections& out_sections(this->output_sections()); |
|
|
|
Relocate_info<32, big_endian> relinfo; |
|
relinfo.symtab = symtab; |
|
relinfo.layout = layout; |
|
relinfo.object = this; |
|
|
|
// Do relocation stubs scanning. |
|
const unsigned char* p = pshdrs + shdr_size; |
|
for (unsigned int i = 1; i < shnum; ++i, p += shdr_size) |
|
{ |
|
const elfcpp::Shdr<32, big_endian> shdr(p); |
|
if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab, |
|
pshdrs)) |
|
{ |
|
unsigned int index = this->adjust_shndx(shdr.get_sh_info()); |
|
Arm_address output_offset = this->get_output_section_offset(index); |
|
Arm_address output_address; |
|
if (output_offset != invalid_address) |
|
output_address = out_sections[index]->address() + output_offset; |
|
else |
|
{ |
|
// Currently this only happens for a relaxed section. |
|
const Output_relaxed_input_section* poris = |
|
out_sections[index]->find_relaxed_input_section(this, index); |
|
gold_assert(poris != NULL); |
|
output_address = poris->address(); |
|
} |
|
|
|
// Get the relocations. |
|
const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(), |
|
shdr.get_sh_size(), |
|
true, false); |
|
|
|
// Get the section contents. This does work for the case in which |
|
// we modify the contents of an input section. We need to pass the |
|
// output view under such circumstances. |
|
section_size_type input_view_size = 0; |
|
const unsigned char* input_view = |
|
this->section_contents(index, &input_view_size, false); |
|
|
|
relinfo.reloc_shndx = i; |
|
relinfo.data_shndx = index; |
|
unsigned int sh_type = shdr.get_sh_type(); |
|
unsigned int reloc_size; |
|
if (sh_type == elfcpp::SHT_REL) |
|
reloc_size = elfcpp::Elf_sizes<32>::rel_size; |
|
else |
|
reloc_size = elfcpp::Elf_sizes<32>::rela_size; |
|
|
|
Output_section* os = out_sections[index]; |
|
arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs, |
|
shdr.get_sh_size() / reloc_size, |
|
os, |
|
output_offset == invalid_address, |
|
input_view, output_address, |
|
input_view_size); |
|
} |
|
} |
|
|
|
// Do Cortex-A8 erratum stubs scanning. This has to be done for a section |
|
// after its relocation section, if there is one, is processed for |
|
// relocation stubs. Merging this loop with the one above would have been |
|
// complicated since we would have had to make sure that relocation stub |
|
// scanning is done first. |
|
if (arm_target->fix_cortex_a8()) |
|
{ |
|
const unsigned char* p = pshdrs + shdr_size; |
|
for (unsigned int i = 1; i < shnum; ++i, p += shdr_size) |
|
{ |
|
const elfcpp::Shdr<32, big_endian> shdr(p); |
|
if (this->section_needs_cortex_a8_stub_scanning(shdr, i, |
|
out_sections[i], |
|
symtab)) |
|
this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i], |
|
arm_target); |
|
} |
|
} |
|
|
|
// After we've done the relocations, we release the hash tables, |
|
// since we no longer need them. |
|
this->free_input_to_output_maps(); |
|
} |
|
|
|
// Count the local symbols. The ARM backend needs to know if a symbol |
|
// is a THUMB function or not. For global symbols, it is easy because |
|
// the Symbol object keeps the ELF symbol type. For local symbol it is |
|
// harder because we cannot access this information. So we override the |
|
// do_count_local_symbol in parent and scan local symbols to mark |
|
// THUMB functions. This is not the most efficient way but I do not want to |
|
// slow down other ports by calling a per symbol target hook inside |
|
// Sized_relobj_file<size, big_endian>::do_count_local_symbols. |
|
|
|
template<bool big_endian> |
|
void |
|
Arm_relobj<big_endian>::do_count_local_symbols( |
|
Stringpool_template<char>* pool, |
|
Stringpool_template<char>* dynpool) |
|
{ |
|
// We need to fix-up the values of any local symbols whose type are |
|
// STT_ARM_TFUNC. |
|
|
|
// Ask parent to count the local symbols. |
|
Sized_relobj_file<32, big_endian>::do_count_local_symbols(pool, dynpool); |
|
const unsigned int loccount = this->local_symbol_count(); |
|
if (loccount == 0) |
|
return; |
|
|
|
// Initialize the thumb function bit-vector. |
|
std::vector<bool> empty_vector(loccount, false); |
|
this->local_symbol_is_thumb_function_.swap(empty_vector); |
|
|
|
// Read the symbol table section header. |
|
const unsigned int symtab_shndx = this->symtab_shndx(); |
|
elfcpp::Shdr<32, big_endian> |
|
symtabshdr(this, this->elf_file()->section_header(symtab_shndx)); |
|
gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB); |
|
|
|
// Read the local symbols. |
|
const int sym_size =elfcpp::Elf_sizes<32>::sym_size; |
|
gold_assert(loccount == symtabshdr.get_sh_info()); |
|
off_t locsize = loccount * sym_size; |
|
const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(), |
|
locsize, true, true); |
|
|
|
// For mapping symbol processing, we need to read the symbol names. |
|
unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link()); |
|
if (strtab_shndx >= this->shnum()) |
|
{ |
|
this->error(_("invalid symbol table name index: %u"), strtab_shndx); |
|
return; |
|
} |
|
|
|
elfcpp::Shdr<32, big_endian> |
|
strtabshdr(this, this->elf_file()->section_header(strtab_shndx)); |
|
if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB) |
|
{ |
|
this->error(_("symbol table name section has wrong type: %u"), |
|
static_cast<unsigned int>(strtabshdr.get_sh_type())); |
|
return; |
|
} |
|
const char* pnames = |
|
reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(), |
|
strtabshdr.get_sh_size(), |
|
false, false)); |
|
|
|
// Loop over the local symbols and mark any local symbols pointing |
|
// to THUMB functions. |
|
|
|
// Skip the first dummy symbol. |
|
psyms += sym_size; |
|
typename Sized_relobj_file<32, big_endian>::Local_values* plocal_values = |
|
this->local_values(); |
|
for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size) |
|
{ |
|
elfcpp::Sym<32, big_endian> sym(psyms); |
|
elfcpp::STT st_type = sym.get_st_type(); |
|
Symbol_value<32>& lv((*plocal_values)[i]); |
|
Arm_address input_value = lv.input_value(); |
|
|
|
// Check to see if this is a mapping symbol. |
|
const char* sym_name = pnames + sym.get_st_name(); |
|
if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name)) |
|
{ |
|
bool is_ordinary; |
|
unsigned int input_shndx = |
|
this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary); |
|
gold_assert(is_ordinary); |
|
|
|
// Strip of LSB in case this is a THUMB symbol. |
|
Mapping_symbol_position msp(input_shndx, input_value & ~1U); |
|
this->mapping_symbols_info_[msp] = sym_name[1]; |
|
} |
|
|
|
if (st_type == elfcpp::STT_ARM_TFUNC |
|
|| (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0))) |
|
{ |
|
// This is a THUMB function. Mark this and canonicalize the |
|
// symbol value by setting LSB. |
|
this->local_symbol_is_thumb_function_[i] = true; |
|
if ((input_value & 1) == 0) |
|
lv.set_input_value(input_value | 1); |
|
} |
|
} |
|
} |
|
|
|
// Relocate sections. |
|
template<bool big_endian> |
|
void |
|
Arm_relobj<big_endian>::do_relocate_sections( |
|
const Symbol_table* symtab, |
|
const Layout* layout, |
|
const unsigned char* pshdrs, |
|
Output_file* of, |
|
typename Sized_relobj_file<32, big_endian>::Views* pviews) |
|
{ |
|
// Call parent to relocate sections. |
|
Sized_relobj_file<32, big_endian>::do_relocate_sections(symtab, layout, |
|
pshdrs, of, pviews); |
|
|
|
// We do not generate stubs if doing a relocatable link. |
|
if (parameters->options().relocatable()) |
|
return; |
|
|
|
// Relocate stub tables. |
|
unsigned int shnum = this->shnum(); |
|
|
|
Target_arm<big_endian>* arm_target = |
|
Target_arm<big_endian>::default_target(); |
|
|
|
Relocate_info<32, big_endian> relinfo; |
|
relinfo.symtab = symtab; |
|
relinfo.layout = layout; |
|
relinfo.object = this; |
|
|
|
for (unsigned int i = 1; i < shnum; ++i) |
|
{ |
|
Arm_input_section<big_endian>* arm_input_section = |
|
arm_target->find_arm_input_section(this, i); |
|
|
|
if (arm_input_section != NULL |
|
&& arm_input_section->is_stub_table_owner() |
|
&& !arm_input_section->stub_table()->empty()) |
|
{ |
|
// We cannot discard a section if it owns a stub table. |
|
Output_section* os = this->output_section(i); |
|
gold_assert(os != NULL); |
|
|
|
relinfo.reloc_shndx = elfcpp::SHN_UNDEF; |
|
relinfo.reloc_shdr = NULL; |
|
relinfo.data_shndx = i; |
|
relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size; |
|
|
|
gold_assert((*pviews)[i].view != NULL); |
|
|
|
// We are passed the output section view. Adjust it to cover the |
|
// stub table only. |
|
Stub_table<big_endian>* stub_table = arm_input_section->stub_table(); |
|
gold_assert((stub_table->address() >= (*pviews)[i].address) |
|
&& ((stub_table->address() + stub_table->data_size()) |
|
<= (*pviews)[i].address + (*pviews)[i].view_size)); |
|
|
|
off_t offset = stub_table->address() - (*pviews)[i].address; |
|
unsigned char* view = (*pviews)[i].view + offset; |
|
Arm_address address = stub_table->address(); |
|
section_size_type view_size = stub_table->data_size(); |
|
|
|
stub_table->relocate_stubs(&relinfo, arm_target, os, view, address, |
|
view_size); |
|
} |
|
|
|
// Apply Cortex A8 workaround if applicable. |
|
if (this->section_has_cortex_a8_workaround(i)) |
|
{ |
|
unsigned char* view = (*pviews)[i].view; |
|
Arm_address view_address = (*pviews)[i].address; |
|
section_size_type view_size = (*pviews)[i].view_size; |
|
Stub_table<big_endian>* stub_table = this->stub_tables_[i]; |
|
|
|
// Adjust view to cover section. |
|
Output_section* os = this->output_section(i); |
|
gold_assert(os != NULL); |
|
Arm_address section_address = |
|
this->simple_input_section_output_address(i, os); |
|
uint64_t section_size = this->section_size(i); |
|
|
|
gold_assert(section_address >= view_address |
|
&& ((section_address + section_size) |
|
<= (view_address + view_size))); |
|
|
|
unsigned char* section_view = view + (section_address - view_address); |
|
|
|
// Apply the Cortex-A8 workaround to the output address range |
|
// corresponding to this input section. |
|
stub_table->apply_cortex_a8_workaround_to_address_range( |
|
arm_target, |
|
section_view, |
|
section_address, |
|
section_size); |
|
} |
|
} |
|
} |
|
|
|
// Find the linked text section of an EXIDX section by looking at the first |
|
// relocation. 4.4.1 of the EHABI specifications says that an EXIDX section |
|
// must be linked to its associated code section via the sh_link field of |
|
// its section header. However, some tools are broken and the link is not |
|
// always set. LD just drops such an EXIDX section silently, causing the |
|
// associated code not unwindabled. Here we try a little bit harder to |
|
// discover the linked code section. |
|
// |
|
// PSHDR points to the section header of a relocation section of an EXIDX |
|
// section. If we can find a linked text section, return true and |
|
// store the text section index in the location PSHNDX. Otherwise |
|
// return false. |
|
|
|
template<bool big_endian> |
|
bool |
|
Arm_relobj<big_endian>::find_linked_text_section( |
|
const unsigned char* pshdr, |
|
const unsigned char* psyms, |
|
unsigned int* pshndx) |
|
{ |
|
elfcpp::Shdr<32, big_endian> shdr(pshdr); |
|
|
|
// If there is no relocation, we cannot find the linked text section. |
|
size_t reloc_size; |
|
if (shdr.get_sh_type() == elfcpp::SHT_REL) |
|
reloc_size = elfcpp::Elf_sizes<32>::rel_size; |
|
else |
|
reloc_size = elfcpp::Elf_sizes<32>::rela_size; |
|
size_t reloc_count = shdr.get_sh_size() / reloc_size; |
|
|
|
// Get the relocations. |
|
const unsigned char* prelocs = |
|
this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false); |
|
|
|
// Find the REL31 relocation for the first word of the first EXIDX entry. |
|
for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size) |
|
{ |
|
Arm_address r_offset; |
|
typename elfcpp::Elf_types<32>::Elf_WXword r_info; |
|
if (shdr.get_sh_type() == elfcpp::SHT_REL) |
|
{ |
|
typename elfcpp::Rel<32, big_endian> reloc(prelocs); |
|
r_info = reloc.get_r_info(); |
|
r_offset = reloc.get_r_offset(); |
|
} |
|
else |
|
{ |
|
typename elfcpp::Rela<32, big_endian> reloc(prelocs); |
|
r_info = reloc.get_r_info(); |
|
r_offset = reloc.get_r_offset(); |
|
} |
|
|
|
unsigned int r_type = elfcpp::elf_r_type<32>(r_info); |
|
if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31) |
|
continue; |
|
|
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info); |
|
if (r_sym == 0 |
|
|| r_sym >= this->local_symbol_count() |
|
|| r_offset != 0) |
|
continue; |
|
|
|
// This is the relocation for the first word of the first EXIDX entry. |
|
// We expect to see a local section symbol. |
|
const int sym_size = elfcpp::Elf_sizes<32>::sym_size; |
|
elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size); |
|
if (sym.get_st_type() == elfcpp::STT_SECTION) |
|
{ |
|
bool is_ordinary; |
|
*pshndx = |
|
this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary); |
|
gold_assert(is_ordinary); |
|
return true; |
|
} |
|
else |
|
return false; |
|
} |
|
|
|
return false; |
|
} |
|
|
|
// Make an EXIDX input section object for an EXIDX section whose index is |
|
// SHNDX. SHDR is the section header of the EXIDX section and TEXT_SHNDX |
|
// is the section index of the linked text section. |
|
|
|
template<bool big_endian> |
|
void |
|
Arm_relobj<big_endian>::make_exidx_input_section( |
|
unsigned int shndx, |
|
const elfcpp::Shdr<32, big_endian>& shdr, |
|
unsigned int text_shndx, |
|
const elfcpp::Shdr<32, big_endian>& text_shdr) |
|
{ |
|
// Create an Arm_exidx_input_section object for this EXIDX section. |
|
Arm_exidx_input_section* exidx_input_section = |
|
new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(), |
|
shdr.get_sh_addralign(), |
|
text_shdr.get_sh_size()); |
|
|
|
gold_assert(this->exidx_section_map_[shndx] == NULL); |
|
this->exidx_section_map_[shndx] = exidx_input_section; |
|
|
|
if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum()) |
|
{ |
|
gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"), |
|
this->section_name(shndx).c_str(), shndx, text_shndx, |
|
this->name().c_str()); |
|
exidx_input_section->set_has_errors(); |
|
} |
|
else if (this->exidx_section_map_[text_shndx] != NULL) |
|
{ |
|
unsigned other_exidx_shndx = |
|
this->exidx_section_map_[text_shndx]->shndx(); |
|
gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section" |
|
"%s(%u) in %s"), |
|
this->section_name(shndx).c_str(), shndx, |
|
this->section_name(other_exidx_shndx).c_str(), |
|
other_exidx_shndx, this->section_name(text_shndx).c_str(), |
|
text_shndx, this->name().c_str()); |
|
exidx_input_section->set_has_errors(); |
|
} |
|
else |
|
this->exidx_section_map_[text_shndx] = exidx_input_section; |
|
|
|
// Check section flags of text section. |
|
if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0) |
|
{ |
|
gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) " |
|
" in %s"), |
|
this->section_name(shndx).c_str(), shndx, |
|
this->section_name(text_shndx).c_str(), text_shndx, |
|
this->name().c_str()); |
|
exidx_input_section->set_has_errors(); |
|
} |
|
else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0) |
|
// I would like to make this an error but currently ld just ignores |
|
// this. |
|
gold_warning(_("EXIDX section %s(%u) links to non-executable section " |
|
"%s(%u) in %s"), |
|
this->section_name(shndx).c_str(), shndx, |
|
this->section_name(text_shndx).c_str(), text_shndx, |
|
this->name().c_str()); |
|
} |
|
|
|
// Read the symbol information. |
|
|
|
template<bool big_endian> |
|
void |
|
Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd) |
|
{ |
|
// Call parent class to read symbol information. |
|
this->base_read_symbols(sd); |
|
|
|
// If this input file is a binary file, it has no processor |
|
// specific flags and attributes section. |
|
Input_file::Format format = this->input_file()->format(); |
|
if (format != Input_file::FORMAT_ELF) |
|
{ |
|
gold_assert(format == Input_file::FORMAT_BINARY); |
|
this->merge_flags_and_attributes_ = false; |
|
return; |
|
} |
|
|
|
// Read processor-specific flags in ELF file header. |
|
const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset, |
|
elfcpp::Elf_sizes<32>::ehdr_size, |
|
true, false); |
|
elfcpp::Ehdr<32, big_endian> ehdr(pehdr); |
|
this->processor_specific_flags_ = ehdr.get_e_flags(); |
|
|
|
// Go over the section headers and look for .ARM.attributes and .ARM.exidx |
|
// sections. |
|
std::vector<unsigned int> deferred_exidx_sections; |
|
const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size; |
|
const unsigned char* pshdrs = sd->section_headers->data(); |
|
const unsigned char* ps = pshdrs + shdr_size; |
|
bool must_merge_flags_and_attributes = false; |
|
for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size) |
|
{ |
|
elfcpp::Shdr<32, big_endian> shdr(ps); |
|
|
|
// Sometimes an object has no contents except the section name string |
|
// table and an empty symbol table with the undefined symbol. We |
|
// don't want to merge processor-specific flags from such an object. |
|
if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB) |
|
{ |
|
// Symbol table is not empty. |
|
const elfcpp::Elf_types<32>::Elf_WXword sym_size = |
|
elfcpp::Elf_sizes<32>::sym_size; |
|
if (shdr.get_sh_size() > sym_size) |
|
must_merge_flags_and_attributes = true; |
|
} |
|
else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB) |
|
// If this is neither an empty symbol table nor a string table, |
|
// be conservative. |
|
must_merge_flags_and_attributes = true; |
|
|
|
if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES) |
|
{ |
|
gold_assert(this->attributes_section_data_ == NULL); |
|
section_offset_type section_offset = shdr.get_sh_offset(); |
|
section_size_type section_size = |
|
convert_to_section_size_type(shdr.get_sh_size()); |
|
const unsigned char* view = |
|
this->get_view(section_offset, section_size, true, false); |
|
this->attributes_section_data_ = |
|
new Attributes_section_data(view, section_size); |
|
} |
|
else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX) |
|
{ |
|
unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link()); |
|
if (text_shndx == elfcpp::SHN_UNDEF) |
|
deferred_exidx_sections.push_back(i); |
|
else |
|
{ |
|
elfcpp::Shdr<32, big_endian> text_shdr(pshdrs |
|
+ text_shndx * shdr_size); |
|
this->make_exidx_input_section(i, shdr, text_shndx, text_shdr); |
|
} |
|
// EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set. |
|
if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0) |
|
gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"), |
|
this->section_name(i).c_str(), this->name().c_str()); |
|
} |
|
} |
|
|
|
// This is rare. |
|
if (!must_merge_flags_and_attributes) |
|
{ |
|
gold_assert(deferred_exidx_sections.empty()); |
|
this->merge_flags_and_attributes_ = false; |
|
return; |
|
} |
|
|
|
// Some tools are broken and they do not set the link of EXIDX sections. |
|
// We look at the first relocation to figure out the linked sections. |
|
if (!deferred_exidx_sections.empty()) |
|
{ |
|
// We need to go over the section headers again to find the mapping |
|
// from sections being relocated to their relocation sections. This is |
|
// a bit inefficient as we could do that in the loop above. However, |
|
// we do not expect any deferred EXIDX sections normally. So we do not |
|
// want to slow down the most common path. |
|
typedef Unordered_map<unsigned int, unsigned int> Reloc_map; |
|
Reloc_map reloc_map; |
|
ps = pshdrs + shdr_size; |
|
for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size) |
|
{ |
|
elfcpp::Shdr<32, big_endian> shdr(ps); |
|
elfcpp::Elf_Word sh_type = shdr.get_sh_type(); |
|
if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA) |
|
{ |
|
unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info()); |
|
if (info_shndx >= this->shnum()) |
|
gold_error(_("relocation section %u has invalid info %u"), |
|
i, info_shndx); |
|
Reloc_map::value_type value(info_shndx, i); |
|
std::pair<Reloc_map::iterator, bool> result = |
|
reloc_map.insert(value); |
|
if (!result.second) |
|
gold_error(_("section %u has multiple relocation sections " |
|
"%u and %u"), |
|
info_shndx, i, reloc_map[info_shndx]); |
|
} |
|
} |
|
|
|
// Read the symbol table section header. |
|
const unsigned int symtab_shndx = this->symtab_shndx(); |
|
elfcpp::Shdr<32, big_endian> |
|
symtabshdr(this, this->elf_file()->section_header(symtab_shndx)); |
|
gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB); |
|
|
|
// Read the local symbols. |
|
const int sym_size =elfcpp::Elf_sizes<32>::sym_size; |
|
const unsigned int loccount = this->local_symbol_count(); |
|
gold_assert(loccount == symtabshdr.get_sh_info()); |
|
off_t locsize = loccount * sym_size; |
|
const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(), |
|
locsize, true, true); |
|
|
|
// Process the deferred EXIDX sections. |
|
for (unsigned int i = 0; i < deferred_exidx_sections.size(); ++i) |
|
{ |
|
unsigned int shndx = deferred_exidx_sections[i]; |
|
elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size); |
|
unsigned int text_shndx = elfcpp::SHN_UNDEF; |
|
Reloc_map::const_iterator it = reloc_map.find(shndx); |
|
if (it != reloc_map.end()) |
|
find_linked_text_section(pshdrs + it->second * shdr_size, |
|
psyms, &text_shndx); |
|
elfcpp::Shdr<32, big_endian> text_shdr(pshdrs |
|
+ text_shndx * shdr_size); |
|
this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr); |
|
} |
|
} |
|
} |
|
|
|
// Process relocations for garbage collection. The ARM target uses .ARM.exidx |
|
// sections for unwinding. These sections are referenced implicitly by |
|
// text sections linked in the section headers. If we ignore these implicit |
|
// references, the .ARM.exidx sections and any .ARM.extab sections they use |
|
// will be garbage-collected incorrectly. Hence we override the same function |
|
// in the base class to handle these implicit references. |
|
|
|
template<bool big_endian> |
|
void |
|
Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab, |
|
Layout* layout, |
|
Read_relocs_data* rd) |
|
{ |
|
// First, call base class method to process relocations in this object. |
|
Sized_relobj_file<32, big_endian>::do_gc_process_relocs(symtab, layout, rd); |
|
|
|
// If --gc-sections is not specified, there is nothing more to do. |
|
// This happens when --icf is used but --gc-sections is not. |
|
if (!parameters->options().gc_sections()) |
|
return; |
|
|
|
unsigned int shnum = this->shnum(); |
|
const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size; |
|
const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(), |
|
shnum * shdr_size, |
|
true, true); |
|
|
|
// Scan section headers for sections of type SHT_ARM_EXIDX. Add references |
|
// to these from the linked text sections. |
|
const unsigned char* ps = pshdrs + shdr_size; |
|
for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size) |
|
{ |
|
elfcpp::Shdr<32, big_endian> shdr(ps); |
|
if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX) |
|
{ |
|
// Found an .ARM.exidx section, add it to the set of reachable |
|
// sections from its linked text section. |
|
unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link()); |
|
symtab->gc()->add_reference(this, text_shndx, this, i); |
|
} |
|
} |
|
} |
|
|
|
// Update output local symbol count. Owing to EXIDX entry merging, some local |
|
// symbols will be removed in output. Adjust output local symbol count |
|
// accordingly. We can only changed the static output local symbol count. It |
|
// is too late to change the dynamic symbols. |
|
|
|
template<bool big_endian> |
|
void |
|
Arm_relobj<big_endian>::update_output_local_symbol_count() |
|
{ |
|
// Caller should check that this needs updating. We want caller checking |
|
// because output_local_symbol_count_needs_update() is most likely inlined. |
|
gold_assert(this->output_local_symbol_count_needs_update_); |
|
|
|
gold_assert(this->symtab_shndx() != -1U); |
|
if (this->symtab_shndx() == 0) |
|
{ |
|
// This object has no symbols. Weird but legal. |
|
return; |
|
} |
|
|
|
// Read the symbol table section header. |
|
const unsigned int symtab_shndx = this->symtab_shndx(); |
|
elfcpp::Shdr<32, big_endian> |
|
symtabshdr(this, this->elf_file()->section_header(symtab_shndx)); |
|
gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB); |
|
|
|
// Read the local symbols. |
|
const int sym_size = elfcpp::Elf_sizes<32>::sym_size; |
|
const unsigned int loccount = this->local_symbol_count(); |
|
gold_assert(loccount == symtabshdr.get_sh_info()); |
|
off_t locsize = loccount * sym_size; |
|
const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(), |
|
locsize, true, true); |
|
|
|
// Loop over the local symbols. |
|
|
|
typedef typename Sized_relobj_file<32, big_endian>::Output_sections |
|
Output_sections; |
|
const Output_sections& out_sections(this->output_sections()); |
|
unsigned int shnum = this->shnum(); |
|
unsigned int count = 0; |
|
// Skip the first, dummy, symbol. |
|
psyms += sym_size; |
|
for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size) |
|
{ |
|
elfcpp::Sym<32, big_endian> sym(psyms); |
|
|
|
Symbol_value<32>& lv((*this->local_values())[i]); |
|
|
|
// This local symbol was already discarded by do_count_local_symbols. |
|
if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry()) |
|
continue; |
|
|
|
bool is_ordinary; |
|
unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(), |
|
&is_ordinary); |
|
|
|
if (shndx < shnum) |
|
{ |
|
Output_section* os = out_sections[shndx]; |
|
|
|
// This local symbol no longer has an output section. Discard it. |
|
if (os == NULL) |
|
{ |
|
lv.set_no_output_symtab_entry(); |
|
continue; |
|
} |
|
|
|
// Currently we only discard parts of EXIDX input sections. |
|
// We explicitly check for a merged EXIDX input section to avoid |
|
// calling Output_section_data::output_offset unless necessary. |
|
if ((this->get_output_section_offset(shndx) == invalid_address) |
|
&& (this->exidx_input_section_by_shndx(shndx) != NULL)) |
|
{ |
|
section_offset_type output_offset = |
|
os->output_offset(this, shndx, lv.input_value()); |
|
if (output_offset == -1) |
|
{ |
|
// This symbol is defined in a part of an EXIDX input section |
|
// that is discarded due to entry merging. |
|
lv.set_no_output_symtab_entry(); |
|
continue; |
|
} |
|
} |
|
} |
|
|
|
++count; |
|
} |
|
|
|
this->set_output_local_symbol_count(count); |
|
this->output_local_symbol_count_needs_update_ = false; |
|
} |
|
|
|
// Arm_dynobj methods. |
|
|
|
// Read the symbol information. |
|
|
|
template<bool big_endian> |
|
void |
|
Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd) |
|
{ |
|
// Call parent class to read symbol information. |
|
this->base_read_symbols(sd); |
|
|
|
// Read processor-specific flags in ELF file header. |
|
const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset, |
|
elfcpp::Elf_sizes<32>::ehdr_size, |
|
true, false); |
|
elfcpp::Ehdr<32, big_endian> ehdr(pehdr); |
|
this->processor_specific_flags_ = ehdr.get_e_flags(); |
|
|
|
// Read the attributes section if there is one. |
|
// We read from the end because gas seems to put it near the end of |
|
// the section headers. |
|
const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size; |
|
const unsigned char* ps = |
|
sd->section_headers->data() + shdr_size * (this->shnum() - 1); |
|
for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size) |
|
{ |
|
elfcpp::Shdr<32, big_endian> shdr(ps); |
|
if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES) |
|
{ |
|
section_offset_type section_offset = shdr.get_sh_offset(); |
|
section_size_type section_size = |
|
convert_to_section_size_type(shdr.get_sh_size()); |
|
const unsigned char* view = |
|
this->get_view(section_offset, section_size, true, false); |
|
this->attributes_section_data_ = |
|
new Attributes_section_data(view, section_size); |
|
break; |
|
} |
|
} |
|
} |
|
|
|
// Stub_addend_reader methods. |
|
|
|
// Read the addend of a REL relocation of type R_TYPE at VIEW. |
|
|
|
template<bool big_endian> |
|
elfcpp::Elf_types<32>::Elf_Swxword |
|
Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()( |
|
unsigned int r_type, |
|
const unsigned char* view, |
|
const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const |
|
{ |
|
typedef class Arm_relocate_functions<big_endian> RelocFuncs; |
|
|
|
switch (r_type) |
|
{ |
|
case elfcpp::R_ARM_CALL: |
|
case elfcpp::R_ARM_JUMP24: |
|
case elfcpp::R_ARM_PLT32: |
|
{ |
|
typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
|
const Valtype* wv = reinterpret_cast<const Valtype*>(view); |
|
Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); |
|
return Bits<26>::sign_extend32(val << 2); |
|
} |
|
|
|
case elfcpp::R_ARM_THM_CALL: |
|
case elfcpp::R_ARM_THM_JUMP24: |
|
case elfcpp::R_ARM_THM_XPC22: |
|
{ |
|
typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
|
const Valtype* wv = reinterpret_cast<const Valtype*>(view); |
|
Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv); |
|
Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1); |
|
return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn); |
|
} |
|
|
|
case elfcpp::R_ARM_THM_JUMP19: |
|
{ |
|
typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
|
const Valtype* wv = reinterpret_cast<const Valtype*>(view); |
|
Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv); |
|
Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1); |
|
return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn); |
|
} |
|
|
|
default: |
|
gold_unreachable(); |
|
} |
|
} |
|
|
|
// Arm_output_data_got methods. |
|
|
|
// Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries. |
|
// The first one is initialized to be 1, which is the module index for |
|
// the main executable and the second one 0. A reloc of the type |
|
// R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will |
|
// be applied by gold. GSYM is a global symbol. |
|
// |
|
template<bool big_endian> |
|
void |
|
Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc( |
|
unsigned int got_type, |
|
Symbol* gsym) |
|
{ |
|
if (gsym->has_got_offset(got_type)) |
|
return; |
|
|
|
// We are doing a static link. Just mark it as belong to module 1, |
|
// the executable. |
|
unsigned int got_offset = this->add_constant(1); |
|
gsym->set_got_offset(got_type, got_offset); |
|
got_offset = this->add_constant(0); |
|
this->static_relocs_.push_back(Static_reloc(got_offset, |
|
elfcpp::R_ARM_TLS_DTPOFF32, |
|
gsym)); |
|
} |
|
|
|
// Same as the above but for a local symbol. |
|
|
|
template<bool big_endian> |
|
void |
|
Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc( |
|
unsigned int got_type, |
|
Sized_relobj_file<32, big_endian>* object, |
|
unsigned int index) |
|
{ |
|
if (object->local_has_got_offset(index, got_type)) |
|
return; |
|
|
|
// We are doing a static link. Just mark it as belong to module 1, |
|
// the executable. |
|
unsigned int got_offset = this->add_constant(1); |
|
object->set_local_got_offset(index, got_type, got_offset); |
|
got_offset = this->add_constant(0); |
|
this->static_relocs_.push_back(Static_reloc(got_offset, |
|
elfcpp::R_ARM_TLS_DTPOFF32, |
|
object, index)); |
|
} |
|
|
|
template<bool big_endian> |
|
void |
|
Arm_output_data_got<big_endian>::do_write(Output_file* of) |
|
{ |
|
// Call parent to write out GOT. |
|
Output_data_got<32, big_endian>::do_write(of); |
|
|
|
// We are done if there is no fix up. |
|
if (this->static_relocs_.empty()) |
|
return; |
|
|
|
gold_assert(parameters->doing_static_link()); |
|
|
|
const off_t offset = this->offset(); |
|
const section_size_type oview_size = |
|
convert_to_section_size_type(this->data_size()); |
|
unsigned char* const oview = of->get_output_view(offset, oview_size); |
|
|
|
Output_segment* tls_segment = this->layout_->tls_segment(); |
|
gold_assert(tls_segment != NULL); |
|
|
|
// The thread pointer $tp points to the TCB, which is followed by the |
|
// TLS. So we need to adjust $tp relative addressing by this amount. |
|
Arm_address aligned_tcb_size = |
|
align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment()); |
|
|
|
for (size_t i = 0; i < this->static_relocs_.size(); ++i) |
|
{ |
|
Static_reloc& reloc(this->static_relocs_[i]); |
|
|
|
Arm_address value; |
|
if (!reloc.symbol_is_global()) |
|
{ |
|
Sized_relobj_file<32, big_endian>* object = reloc.relobj(); |
|
const Symbol_value<32>* psymval = |
|
reloc.relobj()->local_symbol(reloc.index()); |
|
|
|
// We are doing static linking. Issue an error and skip this |
|
// relocation if the symbol is undefined or in a discarded_section. |
|
bool is_ordinary; |
|
unsigned int shndx = psymval->input_shndx(&is_ordinary); |
|
if ((shndx == elfcpp::SHN_UNDEF) |
|
|| (is_ordinary |
|
&& shndx != elfcpp::SHN_UNDEF |
|
&& !object->is_section_included(shndx) |
|
&& !this->symbol_table_->is_section_folded(object, shndx))) |
|
{ |
|
gold_error(_("undefined or discarded local symbol %u from " |
|
" object %s in GOT"), |
|
reloc.index(), reloc.relobj()->name().c_str()); |
|
continue; |
|
} |
|
|
|
value = psymval->value(object, 0); |
|
} |
|
else |
|
{ |
|
const Symbol* gsym = reloc.symbol(); |
|
gold_assert(gsym != NULL); |
|
if (gsym->is_forwarder()) |
|
gsym = this->symbol_table_->resolve_forwards(gsym); |
|
|
|
// We are doing static linking. Issue an error and skip this |
|
// relocation if the symbol is undefined or in a discarded_section |
|
// unless it is a weakly_undefined symbol. |
|
if ((gsym->is_defined_in_discarded_section() |
|
|| gsym->is_undefined()) |
|
&& !gsym->is_weak_undefined()) |
|
{ |
|
gold_error(_("undefined or discarded symbol %s in GOT"), |
|
gsym->name()); |
|
continue; |
|
} |
|
|
|
if (!gsym->is_weak_undefined()) |
|
{ |
|
const Sized_symbol<32>* sym = |
|
static_cast<const Sized_symbol<32>*>(gsym); |
|
value = sym->value(); |
|
} |
|
else |
|
value = 0; |
|
} |
|
|
|
unsigned got_offset = reloc.got_offset(); |
|
gold_assert(got_offset < oview_size); |
|
|
|
typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset); |
|
Valtype x; |
|
switch (reloc.r_type()) |
|
{ |
|
case elfcpp::R_ARM_TLS_DTPOFF32: |
|
x = value; |
|
break; |
|
case elfcpp::R_ARM_TLS_TPOFF32: |
|
x = value + aligned_tcb_size; |
|
break; |
|
default: |
|
gold_unreachable(); |
|
} |
|
elfcpp::Swap<32, big_endian>::writeval(wv, x); |
|
} |
|
|
|
of->write_output_view(offset, oview_size, oview); |
|
} |
|
|
|
// A class to handle the PLT data. |
|
// This is an abstract base class that handles most of the linker details |
|
// but does not know the actual contents of PLT entries. The derived |
|
// classes below fill in those details. |
|
|
|
template<bool big_endian> |
|
class Output_data_plt_arm : public Output_section_data |
|
{ |
|
public: |
|
// Unlike aarch64, which records symbol value in "addend" field of relocations |
|
// and could be done at the same time an IRelative reloc is created for the |
|
// symbol, arm puts the symbol value into "GOT" table, which, however, is |
|
// issued later in Output_data_plt_arm::do_write(). So we have a struct here |
|
// to keep necessary symbol information for later use in do_write. We usually |
|
// have only a very limited number of ifuncs, so the extra data required here |
|
// is also limited. |
|
|
|
struct IRelative_data |
|
{ |
|
IRelative_data(Sized_symbol<32>* sized_symbol) |
|
: symbol_is_global_(true) |
|
{ |
|
u_.global = sized_symbol; |
|
} |
|
|
|
IRelative_data(Sized_relobj_file<32, big_endian>* relobj, |
|
unsigned int index) |
|
: symbol_is_global_(false) |
|
{ |
|
u_.local.relobj = relobj; |
|
u_.local.index = index; |
|
} |
|
|
|
union |
|
{ |
|
Sized_symbol<32>* global; |
|
|
|
struct |
|
{ |
|
Sized_relobj_file<32, big_endian>* relobj; |
|
unsigned int index; |
|
} local; |
|
} u_; |
|
|
|
bool symbol_is_global_; |
|
}; |
|
|
|
typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian> |
|
Reloc_section; |
|
|
|
Output_data_plt_arm(Layout* layout, uint64_t addralign, |
|
Arm_output_data_got<big_endian>* got, |
|
Output_data_space* got_plt, |
|
Output_data_space* got_irelative); |
|
|
|
// Add an entry to the PLT. |
|
void |
|
add_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym); |
|
|
|
// Add the relocation for a plt entry. |
|
void |
|
add_relocation(Symbol_table* symtab, Layout* layout, |
|
Symbol* gsym, unsigned int got_offset); |
|
|
|
// Add an entry to the PLT for a local STT_GNU_IFUNC symbol. |
|
unsigned int |
|
add_local_ifunc_entry(Symbol_table* symtab, Layout*, |
|
Sized_relobj_file<32, big_endian>* relobj, |
|
unsigned int local_sym_index); |
|
|
|
// Return the .rel.plt section data. |
|
const Reloc_section* |
|
rel_plt() const |
|
{ return this->rel_; } |
|
|
|
// Return the PLT relocation container for IRELATIVE. |
|
Reloc_section* |
|
rel_irelative(Symbol_table*, Layout*); |
|
|
|
// Return the number of PLT entries. |
|
unsigned int |
|
entry_count() const |
|
{ return this->count_ + this->irelative_count_; } |
|
|
|
// Return the offset of the first non-reserved PLT entry. |
|
unsigned int |
|
first_plt_entry_offset() const |
|
{ return this->do_first_plt_entry_offset(); } |
|
|
|
// Return the size of a PLT entry. |
|
unsigned int |
|
get_plt_entry_size() const |
|
{ return this->do_get_plt_entry_size(); } |
|
|
|
// Return the PLT address for globals. |
|
uint32_t |
|
address_for_global(const Symbol*) const; |
|
|
|
// Return the PLT address for locals. |
|
uint32_t |
|
address_for_local(const Relobj*, unsigned int symndx) const; |
|
|
|
protected: |
|
// Fill in the first PLT entry. |
|
void |
|
fill_first_plt_entry(unsigned char* pov, |
|
Arm_address got_address, |
|
Arm_address plt_address) |
|
{ this->do_fill_first_plt_entry(pov, got_address, plt_address); } |
|
|
|
void |
|
fill_plt_entry(unsigned char* pov, |
|
Arm_address got_address, |
|
Arm_address plt_address, |
|
unsigned int got_offset, |
|
unsigned int plt_offset) |
|
{ do_fill_plt_entry(pov, got_address, plt_address, got_offset, plt_offset); } |
|
|
|
virtual unsigned int |
|
do_first_plt_entry_offset() const = 0; |
|
|
|
virtual unsigned int |
|
do_get_plt_entry_size() const = 0; |
|
|
|
virtual void |
|
do_fill_first_plt_entry(unsigned char* pov, |
|
Arm_address got_address, |
|
Arm_address plt_address) = 0; |
|
|
|
virtual void |
|
do_fill_plt_entry(unsigned char* pov, |
|
Arm_address got_address, |
|
Arm_address plt_address, |
|
unsigned int got_offset, |
|
unsigned int plt_offset) = 0; |
|
|
|
void |
|
do_adjust_output_section(Output_section* os); |
|
|
|
// Write to a map file. |
|
void |
|
do_print_to_mapfile(Mapfile* mapfile) const |
|
{ mapfile->print_output_data(this, _("** PLT")); } |
|
|
|
private: |
|
// Set the final size. |
|
void |
|
set_final_data_size() |
|
{ |
|
this->set_data_size(this->first_plt_entry_offset() |
|
+ ((this->count_ + this->irelative_count_) |
|
* this->get_plt_entry_size())); |
|
} |
|
|
|
// Write out the PLT data. |
|
void |
|
do_write(Output_file*); |
|
|
|
// Record irelative symbol data. |
|
void insert_irelative_data(const IRelative_data& idata) |
|
{ irelative_data_vec_.push_back(idata); } |
|
|
|
// The reloc section. |
|
Reloc_section* rel_; |
|
// The IRELATIVE relocs, if necessary. These must follow the |
|
// regular PLT relocations. |
|
Reloc_section* irelative_rel_; |
|
// The .got section. |
|
Arm_output_data_got<big_endian>* got_; |
|
// The .got.plt section. |
|
Output_data_space* got_plt_; |
|
// The part of the .got.plt section used for IRELATIVE relocs. |
|
Output_data_space* got_irelative_; |
|
// The number of PLT entries. |
|
unsigned int count_; |
|
// Number of PLT entries with R_ARM_IRELATIVE relocs. These |
|
// follow the regular PLT entries. |
|
unsigned int irelative_count_; |
|
// Vector for irelative data. |
|
typedef std::vector<IRelative_data> IRelative_data_vec; |
|
IRelative_data_vec irelative_data_vec_; |
|
}; |
|
|
|
// Create the PLT section. The ordinary .got section is an argument, |
|
// since we need to refer to the start. We also create our own .got |
|
// section just for PLT entries. |
|
|
|
template<bool big_endian> |
|
Output_data_plt_arm<big_endian>::Output_data_plt_arm( |
|
Layout* layout, uint64_t addralign, |
|
Arm_output_data_got<big_endian>* got, |
|
Output_data_space* got_plt, |
|
Output_data_space* got_irelative) |
|
: Output_section_data(addralign), irelative_rel_(NULL), |
|
got_(got), got_plt_(got_plt), got_irelative_(got_irelative), |
|
count_(0), irelative_count_(0) |
|
{ |
|
this->rel_ = new Reloc_section(false); |
|
layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL, |
|
elfcpp::SHF_ALLOC, this->rel_, |
|
ORDER_DYNAMIC_PLT_RELOCS, false); |
|
} |
|
|
|
template<bool big_endian> |
|
void |
|
Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os) |
|
{ |
|
os->set_entsize(0); |
|
} |
|
|
|
// Add an entry to the PLT. |
|
|
|
template<bool big_endian> |
|
void |
|
Output_data_plt_arm<big_endian>::add_entry(Symbol_table* symtab, |
|
Layout* layout, |
|
Symbol* gsym) |
|
{ |
|
gold_assert(!gsym->has_plt_offset()); |
|
|
|
unsigned int* entry_count; |
|
Output_section_data_build* got; |
|
|
|
// We have 2 different types of plt entry here, normal and ifunc. |
|
|
|
// For normal plt, the offset begins with first_plt_entry_offset(20), and the |
|
// 1st entry offset would be 20, the second 32, third 44 ... etc. |
|
|
|
// For ifunc plt, the offset begins with 0. So the first offset would 0, |
|
// second 12, third 24 ... etc. |
|
|
|
// IFunc plt entries *always* come after *normal* plt entries. |
|
|
|
// Notice, when computing the plt address of a certain symbol, "plt_address + |
|
// plt_offset" is no longer correct. Use target->plt_address_for_global() or |
|
// target->plt_address_for_local() instead. |
|
|
|
int begin_offset = 0; |
|
if (gsym->type() == elfcpp::STT_GNU_IFUNC |
|
&& gsym->can_use_relative_reloc(false)) |
|
{ |
|
entry_count = &this->irelative_count_; |
|
got = this->got_irelative_; |
|
// For irelative plt entries, offset is relative to the end of normal plt |
|
// entries, so it starts from 0. |
|
begin_offset = 0; |
|
// Record symbol information. |
|
this->insert_irelative_data( |
|
IRelative_data(symtab->get_sized_symbol<32>(gsym))); |
|
} |
|
else |
|
{ |
|
entry_count = &this->count_; |
|
got = this->got_plt_; |
|
// Note that for normal plt entries, when setting the PLT offset we skip |
|
// the initial reserved PLT entry. |
|
begin_offset = this->first_plt_entry_offset(); |
|
} |
|
|
|
gsym->set_plt_offset(begin_offset |
|
+ (*entry_count) * this->get_plt_entry_size()); |
|
|
|
++(*entry_count); |
|
|
|
section_offset_type got_offset = got->current_data_size(); |
|
|
|
// Every PLT entry needs a GOT entry which points back to the PLT |
|
// entry (this will be changed by the dynamic linker, normally |
|
// lazily when the function is called). |
|
got->set_current_data_size(got_offset + 4); |
|
|
|
// Every PLT entry needs a reloc. |
|
this->add_relocation(symtab, layout, gsym, got_offset); |
|
|
|
// Note that we don't need to save the symbol. The contents of the |
|
// PLT are independent of which symbols are used. The symbols only |
|
// appear in the relocations. |
|
} |
|
|
|
// Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return |
|
// the PLT offset. |
|
|
|
template<bool big_endian> |
|
unsigned int |
|
Output_data_plt_arm<big_endian>::add_local_ifunc_entry( |
|
Symbol_table* symtab, |
|
Layout* layout, |
|
Sized_relobj_file<32, big_endian>* relobj, |
|
unsigned int local_sym_index) |
|
{ |
|
this->insert_irelative_data(IRelative_data(relobj, local_sym_index)); |
|
|
|
// Notice, when computingthe plt entry address, "plt_address + plt_offset" is |
|
// no longer correct. Use target->plt_address_for_local() instead. |
|
unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size(); |
|
++this->irelative_count_; |
|
|
|
section_offset_type got_offset = this->got_irelative_->current_data_size(); |
|
|
|
// Every PLT entry needs a GOT entry which points back to the PLT |
|
// entry. |
|
this->got_irelative_->set_current_data_size(got_offset + 4); |
|
|
|
|
|
// Every PLT entry needs a reloc. |
|
Reloc_section* rel = this->rel_irelative(symtab, layout); |
|
rel->add_symbolless_local_addend(relobj, local_sym_index, |
|
elfcpp::R_ARM_IRELATIVE, |
|
this->got_irelative_, got_offset); |
|
return plt_offset; |
|
} |
|
|
|
|
|
// Add the relocation for a PLT entry. |
|
|
|
template<bool big_endian> |
|
void |
|
Output_data_plt_arm<big_endian>::add_relocation( |
|
Symbol_table* symtab, Layout* layout, Symbol* gsym, unsigned int got_offset) |
|
{ |
|
if (gsym->type() == elfcpp::STT_GNU_IFUNC |
|
&& gsym->can_use_relative_reloc(false)) |
|
{ |
|
Reloc_section* rel = this->rel_irelative(symtab, layout); |
|
rel->add_symbolless_global_addend(gsym, elfcpp::R_ARM_IRELATIVE, |
|
this->got_irelative_, got_offset); |
|
} |
|
else |
|
{ |
|
gsym->set_needs_dynsym_entry(); |
|
this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_, |
|
got_offset); |
|
} |
|
} |
|
|
|
|
|
// Create the irelative relocation data. |
|
|
|
template<bool big_endian> |
|
typename Output_data_plt_arm<big_endian>::Reloc_section* |
|
Output_data_plt_arm<big_endian>::rel_irelative(Symbol_table* symtab, |
|
Layout* layout) |
|
{ |
|
if (this->irelative_rel_ == NULL) |
|
{ |
|
// Since irelative relocations goes into 'rel.dyn', we delegate the |
|
// creation of irelative_rel_ to where rel_dyn section gets created. |
|
Target_arm<big_endian>* arm_target = |
|
Target_arm<big_endian>::default_target(); |
|
this->irelative_rel_ = arm_target->rel_irelative_section(layout); |
|
|
|
// Make sure we have a place for the TLSDESC relocations, in |
|
// case we see any later on. |
|
// this->rel_tlsdesc(layout); |
|
if (parameters->doing_static_link()) |
|
{ |
|
// A statically linked executable will only have a .rel.plt section to |
|
// hold R_ARM_IRELATIVE relocs for STT_GNU_IFUNC symbols. The library |
|
// will use these symbols to locate the IRELATIVE relocs at program |
|
// startup time. |
|
symtab->define_in_output_data("__rel_iplt_start", NULL, |
|
Symbol_table::PREDEFINED, |
|
this->irelative_rel_, 0, 0, |
|
elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL, |
|
elfcpp::STV_HIDDEN, 0, false, true); |
|
symtab->define_in_output_data("__rel_iplt_end", NULL, |
|
Symbol_table::PREDEFINED, |
|
this->irelative_rel_, 0, 0, |
|
elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL, |
|
elfcpp::STV_HIDDEN, 0, true, true); |
|
} |
|
} |
|
return this->irelative_rel_; |
|
} |
|
|
|
|
|
// Return the PLT address for a global symbol. |
|
|
|
template<bool big_endian> |
|
uint32_t |
|
Output_data_plt_arm<big_endian>::address_for_global(const Symbol* gsym) const |
|
{ |
|
uint64_t begin_offset = 0; |
|
if (gsym->type() == elfcpp::STT_GNU_IFUNC |
|
&& gsym->can_use_relative_reloc(false)) |
|
{ |
|
begin_offset = (this->first_plt_entry_offset() + |
|
this->count_ * this->get_plt_entry_size()); |
|
} |
|
return this->address() + begin_offset + gsym->plt_offset(); |
|
} |
|
|
|
|
|
// Return the PLT address for a local symbol. These are always |
|
// IRELATIVE relocs. |
|
|
|
template<bool big_endian> |
|
uint32_t |
|
Output_data_plt_arm<big_endian>::address_for_local( |
|
const Relobj* object, |
|
unsigned int r_sym) const |
|
{ |
|
return (this->address() |
|
+ this->first_plt_entry_offset() |
|
+ this->count_ * this->get_plt_entry_size() |
|
+ object->local_plt_offset(r_sym)); |
|
} |
|
|
|
|
|
template<bool big_endian> |
|
class Output_data_plt_arm_standard : public Output_data_plt_arm<big_endian> |
|
{ |
|
public: |
|
Output_data_plt_arm_standard(Layout* layout, |
|
Arm_output_data_got<big_endian>* got, |
|
Output_data_space* got_plt, |
|
Output_data_space* got_irelative) |
|
: Output_data_plt_arm<big_endian>(layout, 4, got, got_plt, got_irelative) |
|
{ } |
|
|
|
protected: |
|
// Return the offset of the first non-reserved PLT entry. |
|
virtual unsigned int |
|
do_first_plt_entry_offset() const |
|
{ return sizeof(first_plt_entry); } |
|
|
|
virtual void |
|
do_fill_first_plt_entry(unsigned char* pov, |
|
Arm_address got_address, |
|
Arm_address plt_address); |
|
|
|
private: |
|
// Template for the first PLT entry. |
|
static const uint32_t first_plt_entry[5]; |
|
}; |
|
|
|
// ARM PLTs. |
|
// FIXME: This is not very flexible. Right now this has only been tested |
|
// on armv5te. If we are to support additional architecture features like |
|
// Thumb-2 or BE8, we need to make this more flexible like GNU ld. |
|
|
|
// The first entry in the PLT. |
|
template<bool big_endian> |
|
const uint32_t Output_data_plt_arm_standard<big_endian>::first_plt_entry[5] = |
|
{ |
|
0xe52de004, // str lr, [sp, #-4]! |
|
0xe59fe004, // ldr lr, [pc, #4] |
|
0xe08fe00e, // add lr, pc, lr |
|
0xe5bef008, // ldr pc, [lr, #8]! |
|
0x00000000, // &GOT[0] - . |
|
}; |
|
|
|
template<bool big_endian> |
|
void |
|
Output_data_plt_arm_standard<big_endian>::do_fill_first_plt_entry( |
|
unsigned char* pov, |
|
Arm_address got_address, |
|
Arm_address plt_address) |
|
{ |
|
// Write first PLT entry. All but the last word are constants. |
|
const size_t num_first_plt_words = (sizeof(first_plt_entry) |
|
/ sizeof(first_plt_entry[0])); |
|
for (size_t i = 0; i < num_first_plt_words - 1; i++) |
|
elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]); |
|
// Last word in first PLT entry is &GOT[0] - . |
|
elfcpp::Swap<32, big_endian>::writeval(pov + 16, |
|
got_address - (plt_address + 16)); |
|
} |
|
|
|
// Subsequent entries in the PLT. |
|
// This class generates short (12-byte) entries, for displacements up to 2^28. |
|
|
|
template<bool big_endian> |
|
class Output_data_plt_arm_short : public Output_data_plt_arm_standard<big_endian> |
|
{ |
|
public: |
|
Output_data_plt_arm_short(Layout* layout, |
|
Arm_output_data_got<big_endian>* got, |
|
Output_data_space* got_plt, |
|
Output_data_space* got_irelative) |
|
: Output_data_plt_arm_standard<big_endian>(layout, got, got_plt, got_irelative) |
|
{ } |
|
|
|
protected: |
|
// Return the size of a PLT entry. |
|
virtual unsigned int |
|
do_get_plt_entry_size() const |
|
{ return sizeof(plt_entry); } |
|
|
|
virtual void |
|
do_fill_plt_entry(unsigned char* pov, |
|
Arm_address got_address, |
|
Arm_address plt_address, |
|
unsigned int got_offset, |
|
unsigned int plt_offset); |
|
|
|
private: |
|
// Template for subsequent PLT entries. |
|
static const uint32_t plt_entry[3]; |
|
}; |
|
|
|
template<bool big_endian> |
|
const uint32_t Output_data_plt_arm_short<big_endian>::plt_entry[3] = |
|
{ |
|
0xe28fc600, // add ip, pc, #0xNN00000 |
|
0xe28cca00, // add ip, ip, #0xNN000 |
|
0xe5bcf000, // ldr pc, [ip, #0xNNN]! |
|
}; |
|
|
|
template<bool big_endian> |
|
void |
|
Output_data_plt_arm_short<big_endian>::do_fill_plt_entry( |
|
unsigned char* pov, |
|
Arm_address got_address, |
|
Arm_address plt_address, |
|
unsigned int got_offset, |
|
unsigned int plt_offset) |
|
{ |
|
int32_t offset = ((got_address + got_offset) |
|
- (plt_address + plt_offset + 8)); |
|
if (offset < 0 || offset > 0x0fffffff) |
|
gold_error(_("PLT offset too large, try linking with --long-plt")); |
|
|
|
uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff); |
|
elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0); |
|
uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff); |
|
elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1); |
|
uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff); |
|
elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2); |
|
} |
|
|
|
// This class generates long (16-byte) entries, for arbitrary displacements. |
|
|
|
template<bool big_endian> |
|
class Output_data_plt_arm_long : public Output_data_plt_arm_standard<big_endian> |
|
{ |
|
public: |
|
Output_data_plt_arm_long(Layout* layout, |
|
Arm_output_data_got<big_endian>* got, |
|
Output_data_space* got_plt, |
|
Output_data_space* got_irelative) |
|
: Output_data_plt_arm_standard<big_endian>(layout, got, got_plt, got_irelative) |
|
{ } |
|
|
|
protected: |
|
// Return the size of a PLT entry. |
|
virtual unsigned int |
|
do_get_plt_entry_size() const |
|
{ return sizeof(plt_entry); } |
|
|
|
virtual void |
|
do_fill_plt_entry(unsigned char* pov, |
|
Arm_address got_address, |
|
Arm_address plt_address, |
|
unsigned int got_offset, |
|
unsigned int plt_offset); |
|
|
|
private: |
|
// Template for subsequent PLT entries. |
|
static const uint32_t plt_entry[4]; |
|
}; |
|
|
|
template<bool big_endian> |
|
const uint32_t Output_data_plt_arm_long<big_endian>::plt_entry[4] = |
|
{ |
|
0xe28fc200, // add ip, pc, #0xN0000000 |
|
0xe28cc600, // add ip, ip, #0xNN00000 |
|
0xe28cca00, // add ip, ip, #0xNN000 |
|
0xe5bcf000, // ldr pc, [ip, #0xNNN]! |
|
}; |
|
|
|
template<bool big_endian> |
|
void |
|
Output_data_plt_arm_long<big_endian>::do_fill_plt_entry( |
|
unsigned char* pov, |
|
Arm_address got_address, |
|
Arm_address plt_address, |
|
unsigned int got_offset, |
|
unsigned int plt_offset) |
|
{ |
|
int32_t offset = ((got_address + got_offset) |
|
- (plt_address + plt_offset + 8)); |
|
|
|
uint32_t plt_insn0 = plt_entry[0] | (offset >> 28); |
|
elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0); |
|
uint32_t plt_insn1 = plt_entry[1] | ((offset >> 20) & 0xff); |
|
elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1); |
|
uint32_t plt_insn2 = plt_entry[2] | ((offset >> 12) & 0xff); |
|
elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2); |
|
uint32_t plt_insn3 = plt_entry[3] | (offset & 0xfff); |
|
elfcpp::Swap<32, big_endian>::writeval(pov + 12, plt_insn3); |
|
} |
|
|
|
// Write out the PLT. This uses the hand-coded instructions above, |
|
// and adjusts them as needed. This is all specified by the arm ELF |
|
// Processor Supplement. |
|
|
|
template<bool big_endian> |
|
void |
|
Output_data_plt_arm<big_endian>::do_write(Output_file* of) |
|
{ |
|
const off_t offset = this->offset(); |
|
const section_size_type oview_size = |
|
convert_to_section_size_type(this->data_size()); |
|
unsigned char* const oview = of->get_output_view(offset, oview_size); |
|
|
|
const off_t got_file_offset = this->got_plt_->offset(); |
|
gold_assert(got_file_offset + this->got_plt_->data_size() |
|
== this->got_irelative_->offset()); |
|
const section_size_type got_size = |
|
convert_to_section_size_type(this->got_plt_->data_size() |
|
+ this->got_irelative_->data_size()); |
|
unsigned char* const got_view = of->get_output_view(got_file_offset, |
|
got_size); |
|
unsigned char* pov = oview; |
|
|
|
Arm_address plt_address = this->address(); |
|
Arm_address got_address = this->got_plt_->address(); |
|
|
|
// Write first PLT entry. |
|
this->fill_first_plt_entry(pov, got_address, plt_address); |
|
pov += this->first_plt_entry_offset(); |
|
|
|
unsigned char* got_pov = got_view; |
|
|
|
memset(got_pov, 0, 12); |
|
got_pov += 12; |
|
|
|
unsigned int plt_offset = this->first_plt_entry_offset(); |
|
unsigned int got_offset = 12; |
|
const unsigned int count = this->count_ + this->irelative_count_; |
|
gold_assert(this->irelative_count_ == this->irelative_data_vec_.size()); |
|
for (unsigned int i = 0; |
|
i < count; |
|
++i, |
|
pov += this->get_plt_entry_size(), |
|
got_pov += 4, |
|
plt_offset += this->get_plt_entry_size(), |
|
got_offset += 4) |
|
{ |
|
// Set and adjust the PLT entry itself. |
|
this->fill_plt_entry(pov, got_address, plt_address, |
|
got_offset, plt_offset); |
|
|
|
Arm_address value; |
|
if (i < this->count_) |
|
{ |
|
// For non-irelative got entries, the value is the beginning of plt. |
|
value = plt_address; |
|
} |
|
else |
|
{ |
|
// For irelative got entries, the value is the (global/local) symbol |
|
// address. |
|
const IRelative_data& idata = |
|
this->irelative_data_vec_[i - this->count_]; |
|
if (idata.symbol_is_global_) |
|
{ |
|
// Set the entry in the GOT for irelative symbols. The content is |
|
// the address of the ifunc, not the address of plt start. |
|
const Sized_symbol<32>* sized_symbol = idata.u_.global; |
|
gold_assert(sized_symbol->type() == elfcpp::STT_GNU_IFUNC); |
|
value = sized_symbol->value(); |
|
} |
|
else |
|
{ |
|
value = idata.u_.local.relobj->local_symbol_value( |
|
idata.u_.local.index, 0); |
|
} |
|
} |
|
elfcpp::Swap<32, big_endian>::writeval(got_pov, value); |
|
} |
|
|
|
gold_assert(static_cast<section_size_type>(pov - oview) == oview_size); |
|
gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size); |
|
|
|
of->write_output_view(offset, oview_size, oview); |
|
of->write_output_view(got_file_offset, got_size, got_view); |
|
} |
|
|
|
|
|
// Create a PLT entry for a global symbol. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout, |
|
Symbol* gsym) |
|
{ |
|
if (gsym->has_plt_offset()) |
|
return; |
|
|
|
if (this->plt_ == NULL) |
|
this->make_plt_section(symtab, layout); |
|
|
|
this->plt_->add_entry(symtab, layout, gsym); |
|
} |
|
|
|
|
|
// Create the PLT section. |
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::make_plt_section( |
|
Symbol_table* symtab, Layout* layout) |
|
{ |
|
if (this->plt_ == NULL) |
|
{ |
|
// Create the GOT section first. |
|
this->got_section(symtab, layout); |
|
|
|
// GOT for irelatives is create along with got.plt. |
|
gold_assert(this->got_ != NULL |
|
&& this->got_plt_ != NULL |
|
&& this->got_irelative_ != NULL); |
|
this->plt_ = this->make_data_plt(layout, this->got_, this->got_plt_, |
|
this->got_irelative_); |
|
|
|
layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS, |
|
(elfcpp::SHF_ALLOC |
|
| elfcpp::SHF_EXECINSTR), |
|
this->plt_, ORDER_PLT, false); |
|
symtab->define_in_output_data("$a", NULL, |
|
Symbol_table::PREDEFINED, |
|
this->plt_, |
|
0, 0, elfcpp::STT_NOTYPE, |
|
elfcpp::STB_LOCAL, |
|
elfcpp::STV_DEFAULT, 0, |
|
false, false); |
|
} |
|
} |
|
|
|
|
|
// Make a PLT entry for a local STT_GNU_IFUNC symbol. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::make_local_ifunc_plt_entry( |
|
Symbol_table* symtab, Layout* layout, |
|
Sized_relobj_file<32, big_endian>* relobj, |
|
unsigned int local_sym_index) |
|
{ |
|
if (relobj->local_has_plt_offset(local_sym_index)) |
|
return; |
|
if (this->plt_ == NULL) |
|
this->make_plt_section(symtab, layout); |
|
unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout, |
|
relobj, |
|
local_sym_index); |
|
relobj->set_local_plt_offset(local_sym_index, plt_offset); |
|
} |
|
|
|
|
|
// Return the number of entries in the PLT. |
|
|
|
template<bool big_endian> |
|
unsigned int |
|
Target_arm<big_endian>::plt_entry_count() const |
|
{ |
|
if (this->plt_ == NULL) |
|
return 0; |
|
return this->plt_->entry_count(); |
|
} |
|
|
|
// Return the offset of the first non-reserved PLT entry. |
|
|
|
template<bool big_endian> |
|
unsigned int |
|
Target_arm<big_endian>::first_plt_entry_offset() const |
|
{ |
|
return this->plt_->first_plt_entry_offset(); |
|
} |
|
|
|
// Return the size of each PLT entry. |
|
|
|
template<bool big_endian> |
|
unsigned int |
|
Target_arm<big_endian>::plt_entry_size() const |
|
{ |
|
return this->plt_->get_plt_entry_size(); |
|
} |
|
|
|
// Get the section to use for TLS_DESC relocations. |
|
|
|
template<bool big_endian> |
|
typename Target_arm<big_endian>::Reloc_section* |
|
Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const |
|
{ |
|
return this->plt_section()->rel_tls_desc(layout); |
|
} |
|
|
|
// Define the _TLS_MODULE_BASE_ symbol in the TLS segment. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::define_tls_base_symbol( |
|
Symbol_table* symtab, |
|
Layout* layout) |
|
{ |
|
if (this->tls_base_symbol_defined_) |
|
return; |
|
|
|
Output_segment* tls_segment = layout->tls_segment(); |
|
if (tls_segment != NULL) |
|
{ |
|
bool is_exec = parameters->options().output_is_executable(); |
|
symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL, |
|
Symbol_table::PREDEFINED, |
|
tls_segment, 0, 0, |
|
elfcpp::STT_TLS, |
|
elfcpp::STB_LOCAL, |
|
elfcpp::STV_HIDDEN, 0, |
|
(is_exec |
|
? Symbol::SEGMENT_END |
|
: Symbol::SEGMENT_START), |
|
true); |
|
} |
|
this->tls_base_symbol_defined_ = true; |
|
} |
|
|
|
// Create a GOT entry for the TLS module index. |
|
|
|
template<bool big_endian> |
|
unsigned int |
|
Target_arm<big_endian>::got_mod_index_entry( |
|
Symbol_table* symtab, |
|
Layout* layout, |
|
Sized_relobj_file<32, big_endian>* object) |
|
{ |
|
if (this->got_mod_index_offset_ == -1U) |
|
{ |
|
gold_assert(symtab != NULL && layout != NULL && object != NULL); |
|
Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout); |
|
unsigned int got_offset; |
|
if (!parameters->doing_static_link()) |
|
{ |
|
got_offset = got->add_constant(0); |
|
Reloc_section* rel_dyn = this->rel_dyn_section(layout); |
|
rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got, |
|
got_offset); |
|
} |
|
else |
|
{ |
|
// We are doing a static link. Just mark it as belong to module 1, |
|
// the executable. |
|
got_offset = got->add_constant(1); |
|
} |
|
|
|
got->add_constant(0); |
|
this->got_mod_index_offset_ = got_offset; |
|
} |
|
return this->got_mod_index_offset_; |
|
} |
|
|
|
// Optimize the TLS relocation type based on what we know about the |
|
// symbol. IS_FINAL is true if the final address of this symbol is |
|
// known at link time. |
|
|
|
template<bool big_endian> |
|
tls::Tls_optimization |
|
Target_arm<big_endian>::optimize_tls_reloc(bool, int) |
|
{ |
|
// FIXME: Currently we do not do any TLS optimization. |
|
return tls::TLSOPT_NONE; |
|
} |
|
|
|
// Get the Reference_flags for a particular relocation. |
|
|
|
template<bool big_endian> |
|
int |
|
Target_arm<big_endian>::Scan::get_reference_flags(unsigned int r_type) |
|
{ |
|
switch (r_type) |
|
{ |
|
case elfcpp::R_ARM_NONE: |
|
case elfcpp::R_ARM_V4BX: |
|
case elfcpp::R_ARM_GNU_VTENTRY: |
|
case elfcpp::R_ARM_GNU_VTINHERIT: |
|
// No symbol reference. |
|
return 0; |
|
|
|
case elfcpp::R_ARM_ABS32: |
|
case elfcpp::R_ARM_ABS16: |
|
case elfcpp::R_ARM_ABS12: |
|
case elfcpp::R_ARM_THM_ABS5: |
|
case elfcpp::R_ARM_ABS8: |
|
case elfcpp::R_ARM_BASE_ABS: |
|
case elfcpp::R_ARM_MOVW_ABS_NC: |
|
case elfcpp::R_ARM_MOVT_ABS: |
|
case elfcpp::R_ARM_THM_MOVW_ABS_NC: |
|
case elfcpp::R_ARM_THM_MOVT_ABS: |
|
case elfcpp::R_ARM_ABS32_NOI: |
|
return Symbol::ABSOLUTE_REF; |
|
|
|
case elfcpp::R_ARM_REL32: |
|
case elfcpp::R_ARM_LDR_PC_G0: |
|
case elfcpp::R_ARM_SBREL32: |
|
case elfcpp::R_ARM_THM_PC8: |
|
case elfcpp::R_ARM_BASE_PREL: |
|
case elfcpp::R_ARM_MOVW_PREL_NC: |
|
case elfcpp::R_ARM_MOVT_PREL: |
|
case elfcpp::R_ARM_THM_MOVW_PREL_NC: |
|
case elfcpp::R_ARM_THM_MOVT_PREL: |
|
case elfcpp::R_ARM_THM_ALU_PREL_11_0: |
|
case elfcpp::R_ARM_THM_PC12: |
|
case elfcpp::R_ARM_REL32_NOI: |
|
case elfcpp::R_ARM_ALU_PC_G0_NC: |
|
case elfcpp::R_ARM_ALU_PC_G0: |
|
case elfcpp::R_ARM_ALU_PC_G1_NC: |
|
case elfcpp::R_ARM_ALU_PC_G1: |
|
case elfcpp::R_ARM_ALU_PC_G2: |
|
case elfcpp::R_ARM_LDR_PC_G1: |
|
case elfcpp::R_ARM_LDR_PC_G2: |
|
case elfcpp::R_ARM_LDRS_PC_G0: |
|
case elfcpp::R_ARM_LDRS_PC_G1: |
|
case elfcpp::R_ARM_LDRS_PC_G2: |
|
case elfcpp::R_ARM_LDC_PC_G0: |
|
case elfcpp::R_ARM_LDC_PC_G1: |
|
case elfcpp::R_ARM_LDC_PC_G2: |
|
case elfcpp::R_ARM_ALU_SB_G0_NC: |
|
case elfcpp::R_ARM_ALU_SB_G0: |
|
case elfcpp::R_ARM_ALU_SB_G1_NC: |
|
case elfcpp::R_ARM_ALU_SB_G1: |
|
case elfcpp::R_ARM_ALU_SB_G2: |
|
case elfcpp::R_ARM_LDR_SB_G0: |
|
case elfcpp::R_ARM_LDR_SB_G1: |
|
case elfcpp::R_ARM_LDR_SB_G2: |
|
case elfcpp::R_ARM_LDRS_SB_G0: |
|
case elfcpp::R_ARM_LDRS_SB_G1: |
|
case elfcpp::R_ARM_LDRS_SB_G2: |
|
case elfcpp::R_ARM_LDC_SB_G0: |
|
case elfcpp::R_ARM_LDC_SB_G1: |
|
case elfcpp::R_ARM_LDC_SB_G2: |
|
case elfcpp::R_ARM_MOVW_BREL_NC: |
|
case elfcpp::R_ARM_MOVT_BREL: |
|
case elfcpp::R_ARM_MOVW_BREL: |
|
case elfcpp::R_ARM_THM_MOVW_BREL_NC: |
|
case elfcpp::R_ARM_THM_MOVT_BREL: |
|
case elfcpp::R_ARM_THM_MOVW_BREL: |
|
case elfcpp::R_ARM_GOTOFF32: |
|
case elfcpp::R_ARM_GOTOFF12: |
|
case elfcpp::R_ARM_SBREL31: |
|
return Symbol::RELATIVE_REF; |
|
|
|
case elfcpp::R_ARM_PLT32: |
|
case elfcpp::R_ARM_CALL: |
|
case elfcpp::R_ARM_JUMP24: |
|
case elfcpp::R_ARM_THM_CALL: |
|
case elfcpp::R_ARM_THM_JUMP24: |
|
case elfcpp::R_ARM_THM_JUMP19: |
|
case elfcpp::R_ARM_THM_JUMP6: |
|
case elfcpp::R_ARM_THM_JUMP11: |
|
case elfcpp::R_ARM_THM_JUMP8: |
|
// R_ARM_PREL31 is not used to relocate call/jump instructions but |
|
// in unwind tables. It may point to functions via PLTs. |
|
// So we treat it like call/jump relocations above. |
|
case elfcpp::R_ARM_PREL31: |
|
return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF; |
|
|
|
case elfcpp::R_ARM_GOT_BREL: |
|
case elfcpp::R_ARM_GOT_ABS: |
|
case elfcpp::R_ARM_GOT_PREL: |
|
// Absolute in GOT. |
|
return Symbol::ABSOLUTE_REF; |
|
|
|
case elfcpp::R_ARM_TLS_GD32: // Global-dynamic |
|
case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic |
|
case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic |
|
case elfcpp::R_ARM_TLS_IE32: // Initial-exec |
|
case elfcpp::R_ARM_TLS_LE32: // Local-exec |
|
return Symbol::TLS_REF; |
|
|
|
case elfcpp::R_ARM_TARGET1: |
|
case elfcpp::R_ARM_TARGET2: |
|
case elfcpp::R_ARM_COPY: |
|
case elfcpp::R_ARM_GLOB_DAT: |
|
case elfcpp::R_ARM_JUMP_SLOT: |
|
case elfcpp::R_ARM_RELATIVE: |
|
case elfcpp::R_ARM_PC24: |
|
case elfcpp::R_ARM_LDR_SBREL_11_0_NC: |
|
case elfcpp::R_ARM_ALU_SBREL_19_12_NC: |
|
case elfcpp::R_ARM_ALU_SBREL_27_20_CK: |
|
default: |
|
// Not expected. We will give an error later. |
|
return 0; |
|
} |
|
} |
|
|
|
// Report an unsupported relocation against a local symbol. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::Scan::unsupported_reloc_local( |
|
Sized_relobj_file<32, big_endian>* object, |
|
unsigned int r_type) |
|
{ |
|
gold_error(_("%s: unsupported reloc %u against local symbol"), |
|
object->name().c_str(), r_type); |
|
} |
|
|
|
// We are about to emit a dynamic relocation of type R_TYPE. If the |
|
// dynamic linker does not support it, issue an error. The GNU linker |
|
// only issues a non-PIC error for an allocated read-only section. |
|
// Here we know the section is allocated, but we don't know that it is |
|
// read-only. But we check for all the relocation types which the |
|
// glibc dynamic linker supports, so it seems appropriate to issue an |
|
// error even if the section is not read-only. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::Scan::check_non_pic(Relobj* object, |
|
unsigned int r_type) |
|
{ |
|
switch (r_type) |
|
{ |
|
// These are the relocation types supported by glibc for ARM. |
|
case elfcpp::R_ARM_RELATIVE: |
|
case elfcpp::R_ARM_COPY: |
|
case elfcpp::R_ARM_GLOB_DAT: |
|
case elfcpp::R_ARM_JUMP_SLOT: |
|
case elfcpp::R_ARM_ABS32: |
|
case elfcpp::R_ARM_ABS32_NOI: |
|
case elfcpp::R_ARM_IRELATIVE: |
|
case elfcpp::R_ARM_PC24: |
|
// FIXME: The following 3 types are not supported by Android's dynamic |
|
// linker. |
|
case elfcpp::R_ARM_TLS_DTPMOD32: |
|
case elfcpp::R_ARM_TLS_DTPOFF32: |
|
case elfcpp::R_ARM_TLS_TPOFF32: |
|
return; |
|
|
|
default: |
|
{ |
|
// This prevents us from issuing more than one error per reloc |
|
// section. But we can still wind up issuing more than one |
|
// error per object file. |
|
if (this->issued_non_pic_error_) |
|
return; |
|
const Arm_reloc_property* reloc_property = |
|
arm_reloc_property_table->get_reloc_property(r_type); |
|
gold_assert(reloc_property != NULL); |
|
object->error(_("requires unsupported dynamic reloc %s; " |
|
"recompile with -fPIC"), |
|
reloc_property->name().c_str()); |
|
this->issued_non_pic_error_ = true; |
|
return; |
|
} |
|
|
|
case elfcpp::R_ARM_NONE: |
|
gold_unreachable(); |
|
} |
|
} |
|
|
|
|
|
// Return whether we need to make a PLT entry for a relocation of the |
|
// given type against a STT_GNU_IFUNC symbol. |
|
|
|
template<bool big_endian> |
|
bool |
|
Target_arm<big_endian>::Scan::reloc_needs_plt_for_ifunc( |
|
Sized_relobj_file<32, big_endian>* object, |
|
unsigned int r_type) |
|
{ |
|
int flags = Scan::get_reference_flags(r_type); |
|
if (flags & Symbol::TLS_REF) |
|
{ |
|
gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"), |
|
object->name().c_str(), r_type); |
|
return false; |
|
} |
|
return flags != 0; |
|
} |
|
|
|
|
|
// Scan a relocation for a local symbol. |
|
// FIXME: This only handles a subset of relocation types used by Android |
|
// on ARM v5te devices. |
|
|
|
template<bool big_endian> |
|
inline void |
|
Target_arm<big_endian>::Scan::local(Symbol_table* symtab, |
|
Layout* layout, |
|
Target_arm* target, |
|
Sized_relobj_file<32, big_endian>* object, |
|
unsigned int data_shndx, |
|
Output_section* output_section, |
|
const elfcpp::Rel<32, big_endian>& reloc, |
|
unsigned int r_type, |
|
const elfcpp::Sym<32, big_endian>& lsym, |
|
bool is_discarded) |
|
{ |
|
if (is_discarded) |
|
return; |
|
|
|
r_type = get_real_reloc_type(r_type); |
|
|
|
// A local STT_GNU_IFUNC symbol may require a PLT entry. |
|
bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC; |
|
if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type)) |
|
{ |
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
|
target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym); |
|
} |
|
|
|
switch (r_type) |
|
{ |
|
case elfcpp::R_ARM_NONE: |
|
case elfcpp::R_ARM_V4BX: |
|
case elfcpp::R_ARM_GNU_VTENTRY: |
|
case elfcpp::R_ARM_GNU_VTINHERIT: |
|
break; |
|
|
|
case elfcpp::R_ARM_ABS32: |
|
case elfcpp::R_ARM_ABS32_NOI: |
|
// If building a shared library (or a position-independent |
|
// executable), we need to create a dynamic relocation for |
|
// this location. The relocation applied at link time will |
|
// apply the link-time value, so we flag the location with |
|
// an R_ARM_RELATIVE relocation so the dynamic loader can |
|
// relocate it easily. |
|
if (parameters->options().output_is_position_independent()) |
|
{ |
|
Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
|
// If we are to add more other reloc types than R_ARM_ABS32, |
|
// we need to add check_non_pic(object, r_type) here. |
|
rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE, |
|
output_section, data_shndx, |
|
reloc.get_r_offset(), is_ifunc); |
|
} |
|
break; |
|
|
|
case elfcpp::R_ARM_ABS16: |
|
case elfcpp::R_ARM_ABS12: |
|
case elfcpp::R_ARM_THM_ABS5: |
|
case elfcpp::R_ARM_ABS8: |
|
case elfcpp::R_ARM_BASE_ABS: |
|
case elfcpp::R_ARM_MOVW_ABS_NC: |
|
case elfcpp::R_ARM_MOVT_ABS: |
|
case elfcpp::R_ARM_THM_MOVW_ABS_NC: |
|
case elfcpp::R_ARM_THM_MOVT_ABS: |
|
// If building a shared library (or a position-independent |
|
// executable), we need to create a dynamic relocation for |
|
// this location. Because the addend needs to remain in the |
|
// data section, we need to be careful not to apply this |
|
// relocation statically. |
|
if (parameters->options().output_is_position_independent()) |
|
{ |
|
check_non_pic(object, r_type); |
|
Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
|
if (lsym.get_st_type() != elfcpp::STT_SECTION) |
|
rel_dyn->add_local(object, r_sym, r_type, output_section, |
|
data_shndx, reloc.get_r_offset()); |
|
else |
|
{ |
|
gold_assert(lsym.get_st_value() == 0); |
|
unsigned int shndx = lsym.get_st_shndx(); |
|
bool is_ordinary; |
|
shndx = object->adjust_sym_shndx(r_sym, shndx, |
|
&is_ordinary); |
|
if (!is_ordinary) |
|
object->error(_("section symbol %u has bad shndx %u"), |
|
r_sym, shndx); |
|
else |
|
rel_dyn->add_local_section(object, shndx, |
|
r_type, output_section, |
|
data_shndx, reloc.get_r_offset()); |
|
} |
|
} |
|
break; |
|
|
|
case elfcpp::R_ARM_REL32: |
|
case elfcpp::R_ARM_LDR_PC_G0: |
|
case elfcpp::R_ARM_SBREL32: |
|
case elfcpp::R_ARM_THM_CALL: |
|
case elfcpp::R_ARM_THM_PC8: |
|
case elfcpp::R_ARM_BASE_PREL: |
|
case elfcpp::R_ARM_PLT32: |
|
case elfcpp::R_ARM_CALL: |
|
case elfcpp::R_ARM_JUMP24: |
|
case elfcpp::R_ARM_THM_JUMP24: |
|
case elfcpp::R_ARM_SBREL31: |
|
case elfcpp::R_ARM_PREL31: |
|
case elfcpp::R_ARM_MOVW_PREL_NC: |
|
case elfcpp::R_ARM_MOVT_PREL: |
|
case elfcpp::R_ARM_THM_MOVW_PREL_NC: |
|
case elfcpp::R_ARM_THM_MOVT_PREL: |
|
case elfcpp::R_ARM_THM_JUMP19: |
|
case elfcpp::R_ARM_THM_JUMP6: |
|
case elfcpp::R_ARM_THM_ALU_PREL_11_0: |
|
case elfcpp::R_ARM_THM_PC12: |
|
case elfcpp::R_ARM_REL32_NOI: |
|
case elfcpp::R_ARM_ALU_PC_G0_NC: |
|
case elfcpp::R_ARM_ALU_PC_G0: |
|
case elfcpp::R_ARM_ALU_PC_G1_NC: |
|
case elfcpp::R_ARM_ALU_PC_G1: |
|
case elfcpp::R_ARM_ALU_PC_G2: |
|
case elfcpp::R_ARM_LDR_PC_G1: |
|
case elfcpp::R_ARM_LDR_PC_G2: |
|
case elfcpp::R_ARM_LDRS_PC_G0: |
|
case elfcpp::R_ARM_LDRS_PC_G1: |
|
case elfcpp::R_ARM_LDRS_PC_G2: |
|
case elfcpp::R_ARM_LDC_PC_G0: |
|
case elfcpp::R_ARM_LDC_PC_G1: |
|
case elfcpp::R_ARM_LDC_PC_G2: |
|
case elfcpp::R_ARM_ALU_SB_G0_NC: |
|
case elfcpp::R_ARM_ALU_SB_G0: |
|
case elfcpp::R_ARM_ALU_SB_G1_NC: |
|
case elfcpp::R_ARM_ALU_SB_G1: |
|
case elfcpp::R_ARM_ALU_SB_G2: |
|
case elfcpp::R_ARM_LDR_SB_G0: |
|
case elfcpp::R_ARM_LDR_SB_G1: |
|
case elfcpp::R_ARM_LDR_SB_G2: |
|
case elfcpp::R_ARM_LDRS_SB_G0: |
|
case elfcpp::R_ARM_LDRS_SB_G1: |
|
case elfcpp::R_ARM_LDRS_SB_G2: |
|
case elfcpp::R_ARM_LDC_SB_G0: |
|
case elfcpp::R_ARM_LDC_SB_G1: |
|
case elfcpp::R_ARM_LDC_SB_G2: |
|
case elfcpp::R_ARM_MOVW_BREL_NC: |
|
case elfcpp::R_ARM_MOVT_BREL: |
|
case elfcpp::R_ARM_MOVW_BREL: |
|
case elfcpp::R_ARM_THM_MOVW_BREL_NC: |
|
case elfcpp::R_ARM_THM_MOVT_BREL: |
|
case elfcpp::R_ARM_THM_MOVW_BREL: |
|
case elfcpp::R_ARM_THM_JUMP11: |
|
case elfcpp::R_ARM_THM_JUMP8: |
|
// We don't need to do anything for a relative addressing relocation |
|
// against a local symbol if it does not reference the GOT. |
|
break; |
|
|
|
case elfcpp::R_ARM_GOTOFF32: |
|
case elfcpp::R_ARM_GOTOFF12: |
|
// We need a GOT section: |
|
target->got_section(symtab, layout); |
|
break; |
|
|
|
case elfcpp::R_ARM_GOT_BREL: |
|
case elfcpp::R_ARM_GOT_PREL: |
|
{ |
|
// The symbol requires a GOT entry. |
|
Arm_output_data_got<big_endian>* got = |
|
target->got_section(symtab, layout); |
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
|
if (got->add_local(object, r_sym, GOT_TYPE_STANDARD)) |
|
{ |
|
// If we are generating a shared object, we need to add a |
|
// dynamic RELATIVE relocation for this symbol's GOT entry. |
|
if (parameters->options().output_is_position_independent()) |
|
{ |
|
Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
|
rel_dyn->add_local_relative( |
|
object, r_sym, elfcpp::R_ARM_RELATIVE, got, |
|
object->local_got_offset(r_sym, GOT_TYPE_STANDARD)); |
|
} |
|
} |
|
} |
|
break; |
|
|
|
case elfcpp::R_ARM_TARGET1: |
|
case elfcpp::R_ARM_TARGET2: |
|
// This should have been mapped to another type already. |
|
// Fall through. |
|
case elfcpp::R_ARM_COPY: |
|
case elfcpp::R_ARM_GLOB_DAT: |
|
case elfcpp::R_ARM_JUMP_SLOT: |
|
case elfcpp::R_ARM_RELATIVE: |
|
// These are relocations which should only be seen by the |
|
// dynamic linker, and should never be seen here. |
|
gold_error(_("%s: unexpected reloc %u in object file"), |
|
object->name().c_str(), r_type); |
|
break; |
|
|
|
|
|
// These are initial TLS relocs, which are expected when |
|
// linking. |
|
case elfcpp::R_ARM_TLS_GD32: // Global-dynamic |
|
case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic |
|
case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic |
|
case elfcpp::R_ARM_TLS_IE32: // Initial-exec |
|
case elfcpp::R_ARM_TLS_LE32: // Local-exec |
|
{ |
|
bool output_is_shared = parameters->options().shared(); |
|
const tls::Tls_optimization optimized_type |
|
= Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared, |
|
r_type); |
|
switch (r_type) |
|
{ |
|
case elfcpp::R_ARM_TLS_GD32: // Global-dynamic |
|
if (optimized_type == tls::TLSOPT_NONE) |
|
{ |
|
// Create a pair of GOT entries for the module index and |
|
// dtv-relative offset. |
|
Arm_output_data_got<big_endian>* got |
|
= target->got_section(symtab, layout); |
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
|
unsigned int shndx = lsym.get_st_shndx(); |
|
bool is_ordinary; |
|
shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary); |
|
if (!is_ordinary) |
|
{ |
|
object->error(_("local symbol %u has bad shndx %u"), |
|
r_sym, shndx); |
|
break; |
|
} |
|
|
|
if (!parameters->doing_static_link()) |
|
got->add_local_pair_with_rel(object, r_sym, shndx, |
|
GOT_TYPE_TLS_PAIR, |
|
target->rel_dyn_section(layout), |
|
elfcpp::R_ARM_TLS_DTPMOD32); |
|
else |
|
got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, |
|
object, r_sym); |
|
} |
|
else |
|
// FIXME: TLS optimization not supported yet. |
|
gold_unreachable(); |
|
break; |
|
|
|
case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic |
|
if (optimized_type == tls::TLSOPT_NONE) |
|
{ |
|
// Create a GOT entry for the module index. |
|
target->got_mod_index_entry(symtab, layout, object); |
|
} |
|
else |
|
// FIXME: TLS optimization not supported yet. |
|
gold_unreachable(); |
|
break; |
|
|
|
case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic |
|
break; |
|
|
|
case elfcpp::R_ARM_TLS_IE32: // Initial-exec |
|
layout->set_has_static_tls(); |
|
if (optimized_type == tls::TLSOPT_NONE) |
|
{ |
|
// Create a GOT entry for the tp-relative offset. |
|
Arm_output_data_got<big_endian>* got |
|
= target->got_section(symtab, layout); |
|
unsigned int r_sym = |
|
elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
|
if (!parameters->doing_static_link()) |
|
got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET, |
|
target->rel_dyn_section(layout), |
|
elfcpp::R_ARM_TLS_TPOFF32); |
|
else if (!object->local_has_got_offset(r_sym, |
|
GOT_TYPE_TLS_OFFSET)) |
|
{ |
|
got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET); |
|
unsigned int got_offset = |
|
object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET); |
|
got->add_static_reloc(got_offset, |
|
elfcpp::R_ARM_TLS_TPOFF32, object, |
|
r_sym); |
|
} |
|
} |
|
else |
|
// FIXME: TLS optimization not supported yet. |
|
gold_unreachable(); |
|
break; |
|
|
|
case elfcpp::R_ARM_TLS_LE32: // Local-exec |
|
layout->set_has_static_tls(); |
|
if (output_is_shared) |
|
{ |
|
// We need to create a dynamic relocation. |
|
gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION); |
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
|
Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
|
rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32, |
|
output_section, data_shndx, |
|
reloc.get_r_offset()); |
|
} |
|
break; |
|
|
|
default: |
|
gold_unreachable(); |
|
} |
|
} |
|
break; |
|
|
|
case elfcpp::R_ARM_PC24: |
|
case elfcpp::R_ARM_LDR_SBREL_11_0_NC: |
|
case elfcpp::R_ARM_ALU_SBREL_19_12_NC: |
|
case elfcpp::R_ARM_ALU_SBREL_27_20_CK: |
|
default: |
|
unsupported_reloc_local(object, r_type); |
|
break; |
|
} |
|
} |
|
|
|
// Report an unsupported relocation against a global symbol. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::Scan::unsupported_reloc_global( |
|
Sized_relobj_file<32, big_endian>* object, |
|
unsigned int r_type, |
|
Symbol* gsym) |
|
{ |
|
gold_error(_("%s: unsupported reloc %u against global symbol %s"), |
|
object->name().c_str(), r_type, gsym->demangled_name().c_str()); |
|
} |
|
|
|
template<bool big_endian> |
|
inline bool |
|
Target_arm<big_endian>::Scan::possible_function_pointer_reloc( |
|
unsigned int r_type) |
|
{ |
|
switch (r_type) |
|
{ |
|
case elfcpp::R_ARM_PC24: |
|
case elfcpp::R_ARM_THM_CALL: |
|
case elfcpp::R_ARM_PLT32: |
|
case elfcpp::R_ARM_CALL: |
|
case elfcpp::R_ARM_JUMP24: |
|
case elfcpp::R_ARM_THM_JUMP24: |
|
case elfcpp::R_ARM_SBREL31: |
|
case elfcpp::R_ARM_PREL31: |
|
case elfcpp::R_ARM_THM_JUMP19: |
|
case elfcpp::R_ARM_THM_JUMP6: |
|
case elfcpp::R_ARM_THM_JUMP11: |
|
case elfcpp::R_ARM_THM_JUMP8: |
|
// All the relocations above are branches except SBREL31 and PREL31. |
|
return false; |
|
|
|
default: |
|
// Be conservative and assume this is a function pointer. |
|
return true; |
|
} |
|
} |
|
|
|
template<bool big_endian> |
|
inline bool |
|
Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer( |
|
Symbol_table*, |
|
Layout*, |
|
Target_arm<big_endian>* target, |
|
Sized_relobj_file<32, big_endian>*, |
|
unsigned int, |
|
Output_section*, |
|
const elfcpp::Rel<32, big_endian>&, |
|
unsigned int r_type, |
|
const elfcpp::Sym<32, big_endian>&) |
|
{ |
|
r_type = target->get_real_reloc_type(r_type); |
|
return possible_function_pointer_reloc(r_type); |
|
} |
|
|
|
template<bool big_endian> |
|
inline bool |
|
Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer( |
|
Symbol_table*, |
|
Layout*, |
|
Target_arm<big_endian>* target, |
|
Sized_relobj_file<32, big_endian>*, |
|
unsigned int, |
|
Output_section*, |
|
const elfcpp::Rel<32, big_endian>&, |
|
unsigned int r_type, |
|
Symbol* gsym) |
|
{ |
|
// GOT is not a function. |
|
if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0) |
|
return false; |
|
|
|
r_type = target->get_real_reloc_type(r_type); |
|
return possible_function_pointer_reloc(r_type); |
|
} |
|
|
|
// Scan a relocation for a global symbol. |
|
|
|
template<bool big_endian> |
|
inline void |
|
Target_arm<big_endian>::Scan::global(Symbol_table* symtab, |
|
Layout* layout, |
|
Target_arm* target, |
|
Sized_relobj_file<32, big_endian>* object, |
|
unsigned int data_shndx, |
|
Output_section* output_section, |
|
const elfcpp::Rel<32, big_endian>& reloc, |
|
unsigned int r_type, |
|
Symbol* gsym) |
|
{ |
|
// A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got |
|
// section. We check here to avoid creating a dynamic reloc against |
|
// _GLOBAL_OFFSET_TABLE_. |
|
if (!target->has_got_section() |
|
&& strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0) |
|
target->got_section(symtab, layout); |
|
|
|
// A STT_GNU_IFUNC symbol may require a PLT entry. |
|
if (gsym->type() == elfcpp::STT_GNU_IFUNC |
|
&& this->reloc_needs_plt_for_ifunc(object, r_type)) |
|
target->make_plt_entry(symtab, layout, gsym); |
|
|
|
r_type = get_real_reloc_type(r_type); |
|
switch (r_type) |
|
{ |
|
case elfcpp::R_ARM_NONE: |
|
case elfcpp::R_ARM_V4BX: |
|
case elfcpp::R_ARM_GNU_VTENTRY: |
|
case elfcpp::R_ARM_GNU_VTINHERIT: |
|
break; |
|
|
|
case elfcpp::R_ARM_ABS32: |
|
case elfcpp::R_ARM_ABS16: |
|
case elfcpp::R_ARM_ABS12: |
|
case elfcpp::R_ARM_THM_ABS5: |
|
case elfcpp::R_ARM_ABS8: |
|
case elfcpp::R_ARM_BASE_ABS: |
|
case elfcpp::R_ARM_MOVW_ABS_NC: |
|
case elfcpp::R_ARM_MOVT_ABS: |
|
case elfcpp::R_ARM_THM_MOVW_ABS_NC: |
|
case elfcpp::R_ARM_THM_MOVT_ABS: |
|
case elfcpp::R_ARM_ABS32_NOI: |
|
// Absolute addressing relocations. |
|
{ |
|
// Make a PLT entry if necessary. |
|
if (this->symbol_needs_plt_entry(gsym)) |
|
{ |
|
target->make_plt_entry(symtab, layout, gsym); |
|
// Since this is not a PC-relative relocation, we may be |
|
// taking the address of a function. In that case we need to |
|
// set the entry in the dynamic symbol table to the address of |
|
// the PLT entry. |
|
if (gsym->is_from_dynobj() && !parameters->options().shared()) |
|
gsym->set_needs_dynsym_value(); |
|
} |
|
// Make a dynamic relocation if necessary. |
|
if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type))) |
|
{ |
|
if (!parameters->options().output_is_position_independent() |
|
&& gsym->may_need_copy_reloc()) |
|
{ |
|
target->copy_reloc(symtab, layout, object, |
|
data_shndx, output_section, gsym, reloc); |
|
} |
|
else if ((r_type == elfcpp::R_ARM_ABS32 |
|
|| r_type == elfcpp::R_ARM_ABS32_NOI) |
|
&& gsym->type() == elfcpp::STT_GNU_IFUNC |
|
&& gsym->can_use_relative_reloc(false) |
|
&& !gsym->is_from_dynobj() |
|
&& !gsym->is_undefined() |
|
&& !gsym->is_preemptible()) |
|
{ |
|
// Use an IRELATIVE reloc for a locally defined STT_GNU_IFUNC |
|
// symbol. This makes a function address in a PIE executable |
|
// match the address in a shared library that it links against. |
|
Reloc_section* rel_irelative = |
|
target->rel_irelative_section(layout); |
|
unsigned int r_type = elfcpp::R_ARM_IRELATIVE; |
|
rel_irelative->add_symbolless_global_addend( |
|
gsym, r_type, output_section, object, |
|
data_shndx, reloc.get_r_offset()); |
|
} |
|
else if ((r_type == elfcpp::R_ARM_ABS32 |
|
|| r_type == elfcpp::R_ARM_ABS32_NOI) |
|
&& gsym->can_use_relative_reloc(false)) |
|
{ |
|
Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
|
rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE, |
|
output_section, object, |
|
data_shndx, reloc.get_r_offset()); |
|
} |
|
else |
|
{ |
|
check_non_pic(object, r_type); |
|
Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
|
rel_dyn->add_global(gsym, r_type, output_section, object, |
|
data_shndx, reloc.get_r_offset()); |
|
} |
|
} |
|
} |
|
break; |
|
|
|
case elfcpp::R_ARM_GOTOFF32: |
|
case elfcpp::R_ARM_GOTOFF12: |
|
// We need a GOT section. |
|
target->got_section(symtab, layout); |
|
break; |
|
|
|
case elfcpp::R_ARM_REL32: |
|
case elfcpp::R_ARM_LDR_PC_G0: |
|
case elfcpp::R_ARM_SBREL32: |
|
case elfcpp::R_ARM_THM_PC8: |
|
case elfcpp::R_ARM_BASE_PREL: |
|
case elfcpp::R_ARM_MOVW_PREL_NC: |
|
case elfcpp::R_ARM_MOVT_PREL: |
|
case elfcpp::R_ARM_THM_MOVW_PREL_NC: |
|
case elfcpp::R_ARM_THM_MOVT_PREL: |
|
case elfcpp::R_ARM_THM_ALU_PREL_11_0: |
|
case elfcpp::R_ARM_THM_PC12: |
|
case elfcpp::R_ARM_REL32_NOI: |
|
case elfcpp::R_ARM_ALU_PC_G0_NC: |
|
case elfcpp::R_ARM_ALU_PC_G0: |
|
case elfcpp::R_ARM_ALU_PC_G1_NC: |
|
case elfcpp::R_ARM_ALU_PC_G1: |
|
case elfcpp::R_ARM_ALU_PC_G2: |
|
case elfcpp::R_ARM_LDR_PC_G1: |
|
case elfcpp::R_ARM_LDR_PC_G2: |
|
case elfcpp::R_ARM_LDRS_PC_G0: |
|
case elfcpp::R_ARM_LDRS_PC_G1: |
|
case elfcpp::R_ARM_LDRS_PC_G2: |
|
case elfcpp::R_ARM_LDC_PC_G0: |
|
case elfcpp::R_ARM_LDC_PC_G1: |
|
case elfcpp::R_ARM_LDC_PC_G2: |
|
case elfcpp::R_ARM_ALU_SB_G0_NC: |
|
case elfcpp::R_ARM_ALU_SB_G0: |
|
case elfcpp::R_ARM_ALU_SB_G1_NC: |
|
case elfcpp::R_ARM_ALU_SB_G1: |
|
case elfcpp::R_ARM_ALU_SB_G2: |
|
case elfcpp::R_ARM_LDR_SB_G0: |
|
case elfcpp::R_ARM_LDR_SB_G1: |
|
case elfcpp::R_ARM_LDR_SB_G2: |
|
case elfcpp::R_ARM_LDRS_SB_G0: |
|
case elfcpp::R_ARM_LDRS_SB_G1: |
|
case elfcpp::R_ARM_LDRS_SB_G2: |
|
case elfcpp::R_ARM_LDC_SB_G0: |
|
case elfcpp::R_ARM_LDC_SB_G1: |
|
case elfcpp::R_ARM_LDC_SB_G2: |
|
case elfcpp::R_ARM_MOVW_BREL_NC: |
|
case elfcpp::R_ARM_MOVT_BREL: |
|
case elfcpp::R_ARM_MOVW_BREL: |
|
case elfcpp::R_ARM_THM_MOVW_BREL_NC: |
|
case elfcpp::R_ARM_THM_MOVT_BREL: |
|
case elfcpp::R_ARM_THM_MOVW_BREL: |
|
// Relative addressing relocations. |
|
{ |
|
// Make a dynamic relocation if necessary. |
|
if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type))) |
|
{ |
|
if (parameters->options().output_is_executable() |
|
&& target->may_need_copy_reloc(gsym)) |
|
{ |
|
target->copy_reloc(symtab, layout, object, |
|
data_shndx, output_section, gsym, reloc); |
|
} |
|
else |
|
{ |
|
check_non_pic(object, r_type); |
|
Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
|
rel_dyn->add_global(gsym, r_type, output_section, object, |
|
data_shndx, reloc.get_r_offset()); |
|
} |
|
} |
|
} |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_CALL: |
|
case elfcpp::R_ARM_PLT32: |
|
case elfcpp::R_ARM_CALL: |
|
case elfcpp::R_ARM_JUMP24: |
|
case elfcpp::R_ARM_THM_JUMP24: |
|
case elfcpp::R_ARM_SBREL31: |
|
case elfcpp::R_ARM_PREL31: |
|
case elfcpp::R_ARM_THM_JUMP19: |
|
case elfcpp::R_ARM_THM_JUMP6: |
|
case elfcpp::R_ARM_THM_JUMP11: |
|
case elfcpp::R_ARM_THM_JUMP8: |
|
// All the relocation above are branches except for the PREL31 ones. |
|
// A PREL31 relocation can point to a personality function in a shared |
|
// library. In that case we want to use a PLT because we want to |
|
// call the personality routine and the dynamic linkers we care about |
|
// do not support dynamic PREL31 relocations. An REL31 relocation may |
|
// point to a function whose unwinding behaviour is being described but |
|
// we will not mistakenly generate a PLT for that because we should use |
|
// a local section symbol. |
|
|
|
// If the symbol is fully resolved, this is just a relative |
|
// local reloc. Otherwise we need a PLT entry. |
|
if (gsym->final_value_is_known()) |
|
break; |
|
// If building a shared library, we can also skip the PLT entry |
|
// if the symbol is defined in the output file and is protected |
|
// or hidden. |
|
if (gsym->is_defined() |
|
&& !gsym->is_from_dynobj() |
|
&& !gsym->is_preemptible()) |
|
break; |
|
target->make_plt_entry(symtab, layout, gsym); |
|
break; |
|
|
|
case elfcpp::R_ARM_GOT_BREL: |
|
case elfcpp::R_ARM_GOT_ABS: |
|
case elfcpp::R_ARM_GOT_PREL: |
|
{ |
|
// The symbol requires a GOT entry. |
|
Arm_output_data_got<big_endian>* got = |
|
target->got_section(symtab, layout); |
|
if (gsym->final_value_is_known()) |
|
{ |
|
// For a STT_GNU_IFUNC symbol we want the PLT address. |
|
if (gsym->type() == elfcpp::STT_GNU_IFUNC) |
|
got->add_global_plt(gsym, GOT_TYPE_STANDARD); |
|
else |
|
got->add_global(gsym, GOT_TYPE_STANDARD); |
|
} |
|
else |
|
{ |
|
// If this symbol is not fully resolved, we need to add a |
|
// GOT entry with a dynamic relocation. |
|
Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
|
if (gsym->is_from_dynobj() |
|
|| gsym->is_undefined() |
|
|| gsym->is_preemptible() |
|
|| (gsym->visibility() == elfcpp::STV_PROTECTED |
|
&& parameters->options().shared()) |
|
|| (gsym->type() == elfcpp::STT_GNU_IFUNC |
|
&& parameters->options().output_is_position_independent())) |
|
got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, |
|
rel_dyn, elfcpp::R_ARM_GLOB_DAT); |
|
else |
|
{ |
|
// For a STT_GNU_IFUNC symbol we want to write the PLT |
|
// offset into the GOT, so that function pointer |
|
// comparisons work correctly. |
|
bool is_new; |
|
if (gsym->type() != elfcpp::STT_GNU_IFUNC) |
|
is_new = got->add_global(gsym, GOT_TYPE_STANDARD); |
|
else |
|
{ |
|
is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD); |
|
// Tell the dynamic linker to use the PLT address |
|
// when resolving relocations. |
|
if (gsym->is_from_dynobj() |
|
&& !parameters->options().shared()) |
|
gsym->set_needs_dynsym_value(); |
|
} |
|
if (is_new) |
|
rel_dyn->add_global_relative( |
|
gsym, elfcpp::R_ARM_RELATIVE, got, |
|
gsym->got_offset(GOT_TYPE_STANDARD)); |
|
} |
|
} |
|
} |
|
break; |
|
|
|
case elfcpp::R_ARM_TARGET1: |
|
case elfcpp::R_ARM_TARGET2: |
|
// These should have been mapped to other types already. |
|
// Fall through. |
|
case elfcpp::R_ARM_COPY: |
|
case elfcpp::R_ARM_GLOB_DAT: |
|
case elfcpp::R_ARM_JUMP_SLOT: |
|
case elfcpp::R_ARM_RELATIVE: |
|
// These are relocations which should only be seen by the |
|
// dynamic linker, and should never be seen here. |
|
gold_error(_("%s: unexpected reloc %u in object file"), |
|
object->name().c_str(), r_type); |
|
break; |
|
|
|
// These are initial tls relocs, which are expected when |
|
// linking. |
|
case elfcpp::R_ARM_TLS_GD32: // Global-dynamic |
|
case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic |
|
case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic |
|
case elfcpp::R_ARM_TLS_IE32: // Initial-exec |
|
case elfcpp::R_ARM_TLS_LE32: // Local-exec |
|
{ |
|
const bool is_final = gsym->final_value_is_known(); |
|
const tls::Tls_optimization optimized_type |
|
= Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type); |
|
switch (r_type) |
|
{ |
|
case elfcpp::R_ARM_TLS_GD32: // Global-dynamic |
|
if (optimized_type == tls::TLSOPT_NONE) |
|
{ |
|
// Create a pair of GOT entries for the module index and |
|
// dtv-relative offset. |
|
Arm_output_data_got<big_endian>* got |
|
= target->got_section(symtab, layout); |
|
if (!parameters->doing_static_link()) |
|
got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR, |
|
target->rel_dyn_section(layout), |
|
elfcpp::R_ARM_TLS_DTPMOD32, |
|
elfcpp::R_ARM_TLS_DTPOFF32); |
|
else |
|
got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym); |
|
} |
|
else |
|
// FIXME: TLS optimization not supported yet. |
|
gold_unreachable(); |
|
break; |
|
|
|
case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic |
|
if (optimized_type == tls::TLSOPT_NONE) |
|
{ |
|
// Create a GOT entry for the module index. |
|
target->got_mod_index_entry(symtab, layout, object); |
|
} |
|
else |
|
// FIXME: TLS optimization not supported yet. |
|
gold_unreachable(); |
|
break; |
|
|
|
case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic |
|
break; |
|
|
|
case elfcpp::R_ARM_TLS_IE32: // Initial-exec |
|
layout->set_has_static_tls(); |
|
if (optimized_type == tls::TLSOPT_NONE) |
|
{ |
|
// Create a GOT entry for the tp-relative offset. |
|
Arm_output_data_got<big_endian>* got |
|
= target->got_section(symtab, layout); |
|
if (!parameters->doing_static_link()) |
|
got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET, |
|
target->rel_dyn_section(layout), |
|
elfcpp::R_ARM_TLS_TPOFF32); |
|
else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET)) |
|
{ |
|
got->add_global(gsym, GOT_TYPE_TLS_OFFSET); |
|
unsigned int got_offset = |
|
gsym->got_offset(GOT_TYPE_TLS_OFFSET); |
|
got->add_static_reloc(got_offset, |
|
elfcpp::R_ARM_TLS_TPOFF32, gsym); |
|
} |
|
} |
|
else |
|
// FIXME: TLS optimization not supported yet. |
|
gold_unreachable(); |
|
break; |
|
|
|
case elfcpp::R_ARM_TLS_LE32: // Local-exec |
|
layout->set_has_static_tls(); |
|
if (parameters->options().shared()) |
|
{ |
|
// We need to create a dynamic relocation. |
|
Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
|
rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32, |
|
output_section, object, |
|
data_shndx, reloc.get_r_offset()); |
|
} |
|
break; |
|
|
|
default: |
|
gold_unreachable(); |
|
} |
|
} |
|
break; |
|
|
|
case elfcpp::R_ARM_PC24: |
|
case elfcpp::R_ARM_LDR_SBREL_11_0_NC: |
|
case elfcpp::R_ARM_ALU_SBREL_19_12_NC: |
|
case elfcpp::R_ARM_ALU_SBREL_27_20_CK: |
|
default: |
|
unsupported_reloc_global(object, r_type, gsym); |
|
break; |
|
} |
|
} |
|
|
|
// Process relocations for gc. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::gc_process_relocs( |
|
Symbol_table* symtab, |
|
Layout* layout, |
|
Sized_relobj_file<32, big_endian>* object, |
|
unsigned int data_shndx, |
|
unsigned int, |
|
const unsigned char* prelocs, |
|
size_t reloc_count, |
|
Output_section* output_section, |
|
bool needs_special_offset_handling, |
|
size_t local_symbol_count, |
|
const unsigned char* plocal_symbols) |
|
{ |
|
typedef Target_arm<big_endian> Arm; |
|
typedef typename Target_arm<big_endian>::Scan Scan; |
|
|
|
gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan, |
|
typename Target_arm::Relocatable_size_for_reloc>( |
|
symtab, |
|
layout, |
|
this, |
|
object, |
|
data_shndx, |
|
prelocs, |
|
reloc_count, |
|
output_section, |
|
needs_special_offset_handling, |
|
local_symbol_count, |
|
plocal_symbols); |
|
} |
|
|
|
// Scan relocations for a section. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::scan_relocs(Symbol_table* symtab, |
|
Layout* layout, |
|
Sized_relobj_file<32, big_endian>* object, |
|
unsigned int data_shndx, |
|
unsigned int sh_type, |
|
const unsigned char* prelocs, |
|
size_t reloc_count, |
|
Output_section* output_section, |
|
bool needs_special_offset_handling, |
|
size_t local_symbol_count, |
|
const unsigned char* plocal_symbols) |
|
{ |
|
typedef typename Target_arm<big_endian>::Scan Scan; |
|
if (sh_type == elfcpp::SHT_RELA) |
|
{ |
|
gold_error(_("%s: unsupported RELA reloc section"), |
|
object->name().c_str()); |
|
return; |
|
} |
|
|
|
gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>( |
|
symtab, |
|
layout, |
|
this, |
|
object, |
|
data_shndx, |
|
prelocs, |
|
reloc_count, |
|
output_section, |
|
needs_special_offset_handling, |
|
local_symbol_count, |
|
plocal_symbols); |
|
} |
|
|
|
// Finalize the sections. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::do_finalize_sections( |
|
Layout* layout, |
|
const Input_objects* input_objects, |
|
Symbol_table*) |
|
{ |
|
bool merged_any_attributes = false; |
|
// Merge processor-specific flags. |
|
for (Input_objects::Relobj_iterator p = input_objects->relobj_begin(); |
|
p != input_objects->relobj_end(); |
|
++p) |
|
{ |
|
Arm_relobj<big_endian>* arm_relobj = |
|
Arm_relobj<big_endian>::as_arm_relobj(*p); |
|
if (arm_relobj->merge_flags_and_attributes()) |
|
{ |
|
this->merge_processor_specific_flags( |
|
arm_relobj->name(), |
|
arm_relobj->processor_specific_flags()); |
|
this->merge_object_attributes(arm_relobj->name().c_str(), |
|
arm_relobj->attributes_section_data()); |
|
merged_any_attributes = true; |
|
} |
|
} |
|
|
|
for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin(); |
|
p != input_objects->dynobj_end(); |
|
++p) |
|
{ |
|
Arm_dynobj<big_endian>* arm_dynobj = |
|
Arm_dynobj<big_endian>::as_arm_dynobj(*p); |
|
this->merge_processor_specific_flags( |
|
arm_dynobj->name(), |
|
arm_dynobj->processor_specific_flags()); |
|
this->merge_object_attributes(arm_dynobj->name().c_str(), |
|
arm_dynobj->attributes_section_data()); |
|
merged_any_attributes = true; |
|
} |
|
|
|
// Create an empty uninitialized attribute section if we still don't have it |
|
// at this moment. This happens if there is no attributes sections in all |
|
// inputs. |
|
if (this->attributes_section_data_ == NULL) |
|
this->attributes_section_data_ = new Attributes_section_data(NULL, 0); |
|
|
|
const Object_attribute* cpu_arch_attr = |
|
this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch); |
|
// Check if we need to use Cortex-A8 workaround. |
|
if (parameters->options().user_set_fix_cortex_a8()) |
|
this->fix_cortex_a8_ = parameters->options().fix_cortex_a8(); |
|
else |
|
{ |
|
// If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on |
|
// Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown |
|
// profile. |
|
const Object_attribute* cpu_arch_profile_attr = |
|
this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile); |
|
this->fix_cortex_a8_ = |
|
(cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7 |
|
&& (cpu_arch_profile_attr->int_value() == 'A' |
|
|| cpu_arch_profile_attr->int_value() == 0)); |
|
} |
|
|
|
// Check if we can use V4BX interworking. |
|
// The V4BX interworking stub contains BX instruction, |
|
// which is not specified for some profiles. |
|
if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING |
|
&& !this->may_use_v4t_interworking()) |
|
gold_error(_("unable to provide V4BX reloc interworking fix up; " |
|
"the target profile does not support BX instruction")); |
|
|
|
// Fill in some more dynamic tags. |
|
const Reloc_section* rel_plt = (this->plt_ == NULL |
|
? NULL |
|
: this->plt_->rel_plt()); |
|
layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt, |
|
this->rel_dyn_, true, false); |
|
|
|
// Emit any relocs we saved in an attempt to avoid generating COPY |
|
// relocs. |
|
if (this->copy_relocs_.any_saved_relocs()) |
|
this->copy_relocs_.emit(this->rel_dyn_section(layout)); |
|
|
|
// Handle the .ARM.exidx section. |
|
Output_section* exidx_section = layout->find_output_section(".ARM.exidx"); |
|
|
|
if (!parameters->options().relocatable()) |
|
{ |
|
if (exidx_section != NULL |
|
&& exidx_section->type() == elfcpp::SHT_ARM_EXIDX) |
|
{ |
|
// For the ARM target, we need to add a PT_ARM_EXIDX segment for |
|
// the .ARM.exidx section. |
|
if (!layout->script_options()->saw_phdrs_clause()) |
|
{ |
|
gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0, |
|
0) |
|
== NULL); |
|
Output_segment* exidx_segment = |
|
layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R); |
|
exidx_segment->add_output_section_to_nonload(exidx_section, |
|
elfcpp::PF_R); |
|
} |
|
} |
|
} |
|
|
|
// Create an .ARM.attributes section if we have merged any attributes |
|
// from inputs. |
|
if (merged_any_attributes) |
|
{ |
|
Output_attributes_section_data* attributes_section = |
|
new Output_attributes_section_data(*this->attributes_section_data_); |
|
layout->add_output_section_data(".ARM.attributes", |
|
elfcpp::SHT_ARM_ATTRIBUTES, 0, |
|
attributes_section, ORDER_INVALID, |
|
false); |
|
} |
|
|
|
// Fix up links in section EXIDX headers. |
|
for (Layout::Section_list::const_iterator p = layout->section_list().begin(); |
|
p != layout->section_list().end(); |
|
++p) |
|
if ((*p)->type() == elfcpp::SHT_ARM_EXIDX) |
|
{ |
|
Arm_output_section<big_endian>* os = |
|
Arm_output_section<big_endian>::as_arm_output_section(*p); |
|
os->set_exidx_section_link(); |
|
} |
|
} |
|
|
|
// Return whether a direct absolute static relocation needs to be applied. |
|
// In cases where Scan::local() or Scan::global() has created |
|
// a dynamic relocation other than R_ARM_RELATIVE, the addend |
|
// of the relocation is carried in the data, and we must not |
|
// apply the static relocation. |
|
|
|
template<bool big_endian> |
|
inline bool |
|
Target_arm<big_endian>::Relocate::should_apply_static_reloc( |
|
const Sized_symbol<32>* gsym, |
|
unsigned int r_type, |
|
bool is_32bit, |
|
Output_section* output_section) |
|
{ |
|
// If the output section is not allocated, then we didn't call |
|
// scan_relocs, we didn't create a dynamic reloc, and we must apply |
|
// the reloc here. |
|
if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0) |
|
return true; |
|
|
|
int ref_flags = Scan::get_reference_flags(r_type); |
|
|
|
// For local symbols, we will have created a non-RELATIVE dynamic |
|
// relocation only if (a) the output is position independent, |
|
// (b) the relocation is absolute (not pc- or segment-relative), and |
|
// (c) the relocation is not 32 bits wide. |
|
if (gsym == NULL) |
|
return !(parameters->options().output_is_position_independent() |
|
&& (ref_flags & Symbol::ABSOLUTE_REF) |
|
&& !is_32bit); |
|
|
|
// For global symbols, we use the same helper routines used in the |
|
// scan pass. If we did not create a dynamic relocation, or if we |
|
// created a RELATIVE dynamic relocation, we should apply the static |
|
// relocation. |
|
bool has_dyn = gsym->needs_dynamic_reloc(ref_flags); |
|
bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF) |
|
&& gsym->can_use_relative_reloc(ref_flags |
|
& Symbol::FUNCTION_CALL); |
|
return !has_dyn || is_rel; |
|
} |
|
|
|
// Perform a relocation. |
|
|
|
template<bool big_endian> |
|
inline bool |
|
Target_arm<big_endian>::Relocate::relocate( |
|
const Relocate_info<32, big_endian>* relinfo, |
|
Target_arm* target, |
|
Output_section* output_section, |
|
size_t relnum, |
|
const elfcpp::Rel<32, big_endian>& rel, |
|
unsigned int r_type, |
|
const Sized_symbol<32>* gsym, |
|
const Symbol_value<32>* psymval, |
|
unsigned char* view, |
|
Arm_address address, |
|
section_size_type view_size) |
|
{ |
|
if (view == NULL) |
|
return true; |
|
|
|
typedef Arm_relocate_functions<big_endian> Arm_relocate_functions; |
|
|
|
r_type = get_real_reloc_type(r_type); |
|
const Arm_reloc_property* reloc_property = |
|
arm_reloc_property_table->get_implemented_static_reloc_property(r_type); |
|
if (reloc_property == NULL) |
|
{ |
|
std::string reloc_name = |
|
arm_reloc_property_table->reloc_name_in_error_message(r_type); |
|
gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
|
_("cannot relocate %s in object file"), |
|
reloc_name.c_str()); |
|
return true; |
|
} |
|
|
|
const Arm_relobj<big_endian>* object = |
|
Arm_relobj<big_endian>::as_arm_relobj(relinfo->object); |
|
|
|
// If the final branch target of a relocation is THUMB instruction, this |
|
// is 1. Otherwise it is 0. |
|
Arm_address thumb_bit = 0; |
|
Symbol_value<32> symval; |
|
bool is_weakly_undefined_without_plt = false; |
|
bool have_got_offset = false; |
|
unsigned int got_offset = 0; |
|
|
|
// If the relocation uses the GOT entry of a symbol instead of the symbol |
|
// itself, we don't care about whether the symbol is defined or what kind |
|
// of symbol it is. |
|
if (reloc_property->uses_got_entry()) |
|
{ |
|
// Get the GOT offset. |
|
// The GOT pointer points to the end of the GOT section. |
|
// We need to subtract the size of the GOT section to get |
|
// the actual offset to use in the relocation. |
|
// TODO: We should move GOT offset computing code in TLS relocations |
|
// to here. |
|
switch (r_type) |
|
{ |
|
case elfcpp::R_ARM_GOT_BREL: |
|
case elfcpp::R_ARM_GOT_PREL: |
|
if (gsym != NULL) |
|
{ |
|
gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD)); |
|
got_offset = (gsym->got_offset(GOT_TYPE_STANDARD) |
|
- target->got_size()); |
|
} |
|
else |
|
{ |
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); |
|
gold_assert(object->local_has_got_offset(r_sym, |
|
GOT_TYPE_STANDARD)); |
|
got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD) |
|
- target->got_size()); |
|
} |
|
have_got_offset = true; |
|
break; |
|
|
|
default: |
|
break; |
|
} |
|
} |
|
else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs) |
|
{ |
|
if (gsym != NULL) |
|
{ |
|
// This is a global symbol. Determine if we use PLT and if the |
|
// final target is THUMB. |
|
if (gsym->use_plt_offset(Scan::get_reference_flags(r_type))) |
|
{ |
|
// This uses a PLT, change the symbol value. |
|
symval.set_output_value(target->plt_address_for_global(gsym)); |
|
psymval = &symval; |
|
} |
|
else if (gsym->is_weak_undefined()) |
|
{ |
|
// This is a weakly undefined symbol and we do not use PLT |
|
// for this relocation. A branch targeting this symbol will |
|
// be converted into an NOP. |
|
is_weakly_undefined_without_plt = true; |
|
} |
|
else if (gsym->is_undefined() && reloc_property->uses_symbol()) |
|
{ |
|
// This relocation uses the symbol value but the symbol is |
|
// undefined. Exit early and have the caller reporting an |
|
// error. |
|
return true; |
|
} |
|
else |
|
{ |
|
// Set thumb bit if symbol: |
|
// -Has type STT_ARM_TFUNC or |
|
// -Has type STT_FUNC, is defined and with LSB in value set. |
|
thumb_bit = |
|
(((gsym->type() == elfcpp::STT_ARM_TFUNC) |
|
|| (gsym->type() == elfcpp::STT_FUNC |
|
&& !gsym->is_undefined() |
|
&& ((psymval->value(object, 0) & 1) != 0))) |
|
? 1 |
|
: 0); |
|
} |
|
} |
|
else |
|
{ |
|
// This is a local symbol. Determine if the final target is THUMB. |
|
// We saved this information when all the local symbols were read. |
|
elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info(); |
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info); |
|
thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0; |
|
|
|
if (psymval->is_ifunc_symbol() && object->local_has_plt_offset(r_sym)) |
|
{ |
|
symval.set_output_value( |
|
target->plt_address_for_local(object, r_sym)); |
|
psymval = &symval; |
|
} |
|
} |
|
} |
|
else |
|
{ |
|
// This is a fake relocation synthesized for a stub. It does not have |
|
// a real symbol. We just look at the LSB of the symbol value to |
|
// determine if the target is THUMB or not. |
|
thumb_bit = ((psymval->value(object, 0) & 1) != 0); |
|
} |
|
|
|
// Strip LSB if this points to a THUMB target. |
|
if (thumb_bit != 0 |
|
&& reloc_property->uses_thumb_bit() |
|
&& ((psymval->value(object, 0) & 1) != 0)) |
|
{ |
|
Arm_address stripped_value = |
|
psymval->value(object, 0) & ~static_cast<Arm_address>(1); |
|
symval.set_output_value(stripped_value); |
|
psymval = &symval; |
|
} |
|
|
|
// To look up relocation stubs, we need to pass the symbol table index of |
|
// a local symbol. |
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); |
|
|
|
// Get the addressing origin of the output segment defining the |
|
// symbol gsym if needed (AAELF 4.6.1.2 Relocation types). |
|
Arm_address sym_origin = 0; |
|
if (reloc_property->uses_symbol_base()) |
|
{ |
|
if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL) |
|
// R_ARM_BASE_ABS with the NULL symbol will give the |
|
// absolute address of the GOT origin (GOT_ORG) (see ARM IHI |
|
// 0044C (AAELF): 4.6.1.8 Proxy generating relocations). |
|
sym_origin = target->got_plt_section()->address(); |
|
else if (gsym == NULL) |
|
sym_origin = 0; |
|
else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT) |
|
sym_origin = gsym->output_segment()->vaddr(); |
|
else if (gsym->source() == Symbol::IN_OUTPUT_DATA) |
|
sym_origin = gsym->output_data()->address(); |
|
|
|
// TODO: Assumes the segment base to be zero for the global symbols |
|
// till the proper support for the segment-base-relative addressing |
|
// will be implemented. This is consistent with GNU ld. |
|
} |
|
|
|
// For relative addressing relocation, find out the relative address base. |
|
Arm_address relative_address_base = 0; |
|
switch(reloc_property->relative_address_base()) |
|
{ |
|
case Arm_reloc_property::RAB_NONE: |
|
// Relocations with relative address bases RAB_TLS and RAB_tp are |
|
// handled by relocate_tls. So we do not need to do anything here. |
|
case Arm_reloc_property::RAB_TLS: |
|
case Arm_reloc_property::RAB_tp: |
|
break; |
|
case Arm_reloc_property::RAB_B_S: |
|
relative_address_base = sym_origin; |
|
break; |
|
case Arm_reloc_property::RAB_GOT_ORG: |
|
relative_address_base = target->got_plt_section()->address(); |
|
break; |
|
case Arm_reloc_property::RAB_P: |
|
relative_address_base = address; |
|
break; |
|
case Arm_reloc_property::RAB_Pa: |
|
relative_address_base = address & 0xfffffffcU; |
|
break; |
|
default: |
|
gold_unreachable(); |
|
} |
|
|
|
typename Arm_relocate_functions::Status reloc_status = |
|
Arm_relocate_functions::STATUS_OKAY; |
|
bool check_overflow = reloc_property->checks_overflow(); |
|
switch (r_type) |
|
{ |
|
case elfcpp::R_ARM_NONE: |
|
break; |
|
|
|
case elfcpp::R_ARM_ABS8: |
|
if (should_apply_static_reloc(gsym, r_type, false, output_section)) |
|
reloc_status = Arm_relocate_functions::abs8(view, object, psymval); |
|
break; |
|
|
|
case elfcpp::R_ARM_ABS12: |
|
if (should_apply_static_reloc(gsym, r_type, false, output_section)) |
|
reloc_status = Arm_relocate_functions::abs12(view, object, psymval); |
|
break; |
|
|
|
case elfcpp::R_ARM_ABS16: |
|
if (should_apply_static_reloc(gsym, r_type, false, output_section)) |
|
reloc_status = Arm_relocate_functions::abs16(view, object, psymval); |
|
break; |
|
|
|
case elfcpp::R_ARM_ABS32: |
|
if (should_apply_static_reloc(gsym, r_type, true, output_section)) |
|
reloc_status = Arm_relocate_functions::abs32(view, object, psymval, |
|
thumb_bit); |
|
break; |
|
|
|
case elfcpp::R_ARM_ABS32_NOI: |
|
if (should_apply_static_reloc(gsym, r_type, true, output_section)) |
|
// No thumb bit for this relocation: (S + A) |
|
reloc_status = Arm_relocate_functions::abs32(view, object, psymval, |
|
0); |
|
break; |
|
|
|
case elfcpp::R_ARM_MOVW_ABS_NC: |
|
if (should_apply_static_reloc(gsym, r_type, false, output_section)) |
|
reloc_status = Arm_relocate_functions::movw(view, object, psymval, |
|
0, thumb_bit, |
|
check_overflow); |
|
break; |
|
|
|
case elfcpp::R_ARM_MOVT_ABS: |
|
if (should_apply_static_reloc(gsym, r_type, false, output_section)) |
|
reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_MOVW_ABS_NC: |
|
if (should_apply_static_reloc(gsym, r_type, false, output_section)) |
|
reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval, |
|
0, thumb_bit, false); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_MOVT_ABS: |
|
if (should_apply_static_reloc(gsym, r_type, false, output_section)) |
|
reloc_status = Arm_relocate_functions::thm_movt(view, object, |
|
psymval, 0); |
|
break; |
|
|
|
case elfcpp::R_ARM_MOVW_PREL_NC: |
|
case elfcpp::R_ARM_MOVW_BREL_NC: |
|
case elfcpp::R_ARM_MOVW_BREL: |
|
reloc_status = |
|
Arm_relocate_functions::movw(view, object, psymval, |
|
relative_address_base, thumb_bit, |
|
check_overflow); |
|
break; |
|
|
|
case elfcpp::R_ARM_MOVT_PREL: |
|
case elfcpp::R_ARM_MOVT_BREL: |
|
reloc_status = |
|
Arm_relocate_functions::movt(view, object, psymval, |
|
relative_address_base); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_MOVW_PREL_NC: |
|
case elfcpp::R_ARM_THM_MOVW_BREL_NC: |
|
case elfcpp::R_ARM_THM_MOVW_BREL: |
|
reloc_status = |
|
Arm_relocate_functions::thm_movw(view, object, psymval, |
|
relative_address_base, |
|
thumb_bit, check_overflow); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_MOVT_PREL: |
|
case elfcpp::R_ARM_THM_MOVT_BREL: |
|
reloc_status = |
|
Arm_relocate_functions::thm_movt(view, object, psymval, |
|
relative_address_base); |
|
break; |
|
|
|
case elfcpp::R_ARM_REL32: |
|
reloc_status = Arm_relocate_functions::rel32(view, object, psymval, |
|
address, thumb_bit); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_ABS5: |
|
if (should_apply_static_reloc(gsym, r_type, false, output_section)) |
|
reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval); |
|
break; |
|
|
|
// Thumb long branches. |
|
case elfcpp::R_ARM_THM_CALL: |
|
case elfcpp::R_ARM_THM_XPC22: |
|
case elfcpp::R_ARM_THM_JUMP24: |
|
reloc_status = |
|
Arm_relocate_functions::thumb_branch_common( |
|
r_type, relinfo, view, gsym, object, r_sym, psymval, address, |
|
thumb_bit, is_weakly_undefined_without_plt); |
|
break; |
|
|
|
case elfcpp::R_ARM_GOTOFF32: |
|
{ |
|
Arm_address got_origin; |
|
got_origin = target->got_plt_section()->address(); |
|
reloc_status = Arm_relocate_functions::rel32(view, object, psymval, |
|
got_origin, thumb_bit); |
|
} |
|
break; |
|
|
|
case elfcpp::R_ARM_BASE_PREL: |
|
gold_assert(gsym != NULL); |
|
reloc_status = |
|
Arm_relocate_functions::base_prel(view, sym_origin, address); |
|
break; |
|
|
|
case elfcpp::R_ARM_BASE_ABS: |
|
if (should_apply_static_reloc(gsym, r_type, false, output_section)) |
|
reloc_status = Arm_relocate_functions::base_abs(view, sym_origin); |
|
break; |
|
|
|
case elfcpp::R_ARM_GOT_BREL: |
|
gold_assert(have_got_offset); |
|
reloc_status = Arm_relocate_functions::got_brel(view, got_offset); |
|
break; |
|
|
|
case elfcpp::R_ARM_GOT_PREL: |
|
gold_assert(have_got_offset); |
|
// Get the address origin for GOT PLT, which is allocated right |
|
// after the GOT section, to calculate an absolute address of |
|
// the symbol GOT entry (got_origin + got_offset). |
|
Arm_address got_origin; |
|
got_origin = target->got_plt_section()->address(); |
|
reloc_status = Arm_relocate_functions::got_prel(view, |
|
got_origin + got_offset, |
|
address); |
|
break; |
|
|
|
case elfcpp::R_ARM_PLT32: |
|
case elfcpp::R_ARM_CALL: |
|
case elfcpp::R_ARM_JUMP24: |
|
case elfcpp::R_ARM_XPC25: |
|
gold_assert(gsym == NULL |
|
|| gsym->has_plt_offset() |
|
|| gsym->final_value_is_known() |
|
|| (gsym->is_defined() |
|
&& !gsym->is_from_dynobj() |
|
&& !gsym->is_preemptible())); |
|
reloc_status = |
|
Arm_relocate_functions::arm_branch_common( |
|
r_type, relinfo, view, gsym, object, r_sym, psymval, address, |
|
thumb_bit, is_weakly_undefined_without_plt); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_JUMP19: |
|
reloc_status = |
|
Arm_relocate_functions::thm_jump19(view, object, psymval, address, |
|
thumb_bit); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_JUMP6: |
|
reloc_status = |
|
Arm_relocate_functions::thm_jump6(view, object, psymval, address); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_JUMP8: |
|
reloc_status = |
|
Arm_relocate_functions::thm_jump8(view, object, psymval, address); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_JUMP11: |
|
reloc_status = |
|
Arm_relocate_functions::thm_jump11(view, object, psymval, address); |
|
break; |
|
|
|
case elfcpp::R_ARM_PREL31: |
|
reloc_status = Arm_relocate_functions::prel31(view, object, psymval, |
|
address, thumb_bit); |
|
break; |
|
|
|
case elfcpp::R_ARM_V4BX: |
|
if (target->fix_v4bx() > General_options::FIX_V4BX_NONE) |
|
{ |
|
const bool is_v4bx_interworking = |
|
(target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING); |
|
reloc_status = |
|
Arm_relocate_functions::v4bx(relinfo, view, object, address, |
|
is_v4bx_interworking); |
|
} |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_PC8: |
|
reloc_status = |
|
Arm_relocate_functions::thm_pc8(view, object, psymval, address); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_PC12: |
|
reloc_status = |
|
Arm_relocate_functions::thm_pc12(view, object, psymval, address); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_ALU_PREL_11_0: |
|
reloc_status = |
|
Arm_relocate_functions::thm_alu11(view, object, psymval, address, |
|
thumb_bit); |
|
break; |
|
|
|
case elfcpp::R_ARM_ALU_PC_G0_NC: |
|
case elfcpp::R_ARM_ALU_PC_G0: |
|
case elfcpp::R_ARM_ALU_PC_G1_NC: |
|
case elfcpp::R_ARM_ALU_PC_G1: |
|
case elfcpp::R_ARM_ALU_PC_G2: |
|
case elfcpp::R_ARM_ALU_SB_G0_NC: |
|
case elfcpp::R_ARM_ALU_SB_G0: |
|
case elfcpp::R_ARM_ALU_SB_G1_NC: |
|
case elfcpp::R_ARM_ALU_SB_G1: |
|
case elfcpp::R_ARM_ALU_SB_G2: |
|
reloc_status = |
|
Arm_relocate_functions::arm_grp_alu(view, object, psymval, |
|
reloc_property->group_index(), |
|
relative_address_base, |
|
thumb_bit, check_overflow); |
|
break; |
|
|
|
case elfcpp::R_ARM_LDR_PC_G0: |
|
case elfcpp::R_ARM_LDR_PC_G1: |
|
case elfcpp::R_ARM_LDR_PC_G2: |
|
case elfcpp::R_ARM_LDR_SB_G0: |
|
case elfcpp::R_ARM_LDR_SB_G1: |
|
case elfcpp::R_ARM_LDR_SB_G2: |
|
reloc_status = |
|
Arm_relocate_functions::arm_grp_ldr(view, object, psymval, |
|
reloc_property->group_index(), |
|
relative_address_base); |
|
break; |
|
|
|
case elfcpp::R_ARM_LDRS_PC_G0: |
|
case elfcpp::R_ARM_LDRS_PC_G1: |
|
case elfcpp::R_ARM_LDRS_PC_G2: |
|
case elfcpp::R_ARM_LDRS_SB_G0: |
|
case elfcpp::R_ARM_LDRS_SB_G1: |
|
case elfcpp::R_ARM_LDRS_SB_G2: |
|
reloc_status = |
|
Arm_relocate_functions::arm_grp_ldrs(view, object, psymval, |
|
reloc_property->group_index(), |
|
relative_address_base); |
|
break; |
|
|
|
case elfcpp::R_ARM_LDC_PC_G0: |
|
case elfcpp::R_ARM_LDC_PC_G1: |
|
case elfcpp::R_ARM_LDC_PC_G2: |
|
case elfcpp::R_ARM_LDC_SB_G0: |
|
case elfcpp::R_ARM_LDC_SB_G1: |
|
case elfcpp::R_ARM_LDC_SB_G2: |
|
reloc_status = |
|
Arm_relocate_functions::arm_grp_ldc(view, object, psymval, |
|
reloc_property->group_index(), |
|
relative_address_base); |
|
break; |
|
|
|
// These are initial tls relocs, which are expected when |
|
// linking. |
|
case elfcpp::R_ARM_TLS_GD32: // Global-dynamic |
|
case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic |
|
case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic |
|
case elfcpp::R_ARM_TLS_IE32: // Initial-exec |
|
case elfcpp::R_ARM_TLS_LE32: // Local-exec |
|
reloc_status = |
|
this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval, |
|
view, address, view_size); |
|
break; |
|
|
|
// The known and unknown unsupported and/or deprecated relocations. |
|
case elfcpp::R_ARM_PC24: |
|
case elfcpp::R_ARM_LDR_SBREL_11_0_NC: |
|
case elfcpp::R_ARM_ALU_SBREL_19_12_NC: |
|
case elfcpp::R_ARM_ALU_SBREL_27_20_CK: |
|
default: |
|
// Just silently leave the method. We should get an appropriate error |
|
// message in the scan methods. |
|
break; |
|
} |
|
|
|
// Report any errors. |
|
switch (reloc_status) |
|
{ |
|
case Arm_relocate_functions::STATUS_OKAY: |
|
break; |
|
case Arm_relocate_functions::STATUS_OVERFLOW: |
|
gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
|
_("relocation overflow in %s"), |
|
reloc_property->name().c_str()); |
|
break; |
|
case Arm_relocate_functions::STATUS_BAD_RELOC: |
|
gold_error_at_location( |
|
relinfo, |
|
relnum, |
|
rel.get_r_offset(), |
|
_("unexpected opcode while processing relocation %s"), |
|
reloc_property->name().c_str()); |
|
break; |
|
default: |
|
gold_unreachable(); |
|
} |
|
|
|
return true; |
|
} |
|
|
|
// Perform a TLS relocation. |
|
|
|
template<bool big_endian> |
|
inline typename Arm_relocate_functions<big_endian>::Status |
|
Target_arm<big_endian>::Relocate::relocate_tls( |
|
const Relocate_info<32, big_endian>* relinfo, |
|
Target_arm<big_endian>* target, |
|
size_t relnum, |
|
const elfcpp::Rel<32, big_endian>& rel, |
|
unsigned int r_type, |
|
const Sized_symbol<32>* gsym, |
|
const Symbol_value<32>* psymval, |
|
unsigned char* view, |
|
elfcpp::Elf_types<32>::Elf_Addr address, |
|
section_size_type /*view_size*/ ) |
|
{ |
|
typedef Arm_relocate_functions<big_endian> ArmRelocFuncs; |
|
typedef Relocate_functions<32, big_endian> RelocFuncs; |
|
Output_segment* tls_segment = relinfo->layout->tls_segment(); |
|
|
|
const Sized_relobj_file<32, big_endian>* object = relinfo->object; |
|
|
|
elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0); |
|
|
|
const bool is_final = (gsym == NULL |
|
? !parameters->options().shared() |
|
: gsym->final_value_is_known()); |
|
const tls::Tls_optimization optimized_type |
|
= Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type); |
|
switch (r_type) |
|
{ |
|
case elfcpp::R_ARM_TLS_GD32: // Global-dynamic |
|
{ |
|
unsigned int got_type = GOT_TYPE_TLS_PAIR; |
|
unsigned int got_offset; |
|
if (gsym != NULL) |
|
{ |
|
gold_assert(gsym->has_got_offset(got_type)); |
|
got_offset = gsym->got_offset(got_type) - target->got_size(); |
|
} |
|
else |
|
{ |
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); |
|
gold_assert(object->local_has_got_offset(r_sym, got_type)); |
|
got_offset = (object->local_got_offset(r_sym, got_type) |
|
- target->got_size()); |
|
} |
|
if (optimized_type == tls::TLSOPT_NONE) |
|
{ |
|
Arm_address got_entry = |
|
target->got_plt_section()->address() + got_offset; |
|
|
|
// Relocate the field with the PC relative offset of the pair of |
|
// GOT entries. |
|
RelocFuncs::pcrel32_unaligned(view, got_entry, address); |
|
return ArmRelocFuncs::STATUS_OKAY; |
|
} |
|
} |
|
break; |
|
|
|
case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic |
|
if (optimized_type == tls::TLSOPT_NONE) |
|
{ |
|
// Relocate the field with the offset of the GOT entry for |
|
// the module index. |
|
unsigned int got_offset; |
|
got_offset = (target->got_mod_index_entry(NULL, NULL, NULL) |
|
- target->got_size()); |
|
Arm_address got_entry = |
|
target->got_plt_section()->address() + got_offset; |
|
|
|
// Relocate the field with the PC relative offset of the pair of |
|
// GOT entries. |
|
RelocFuncs::pcrel32_unaligned(view, got_entry, address); |
|
return ArmRelocFuncs::STATUS_OKAY; |
|
} |
|
break; |
|
|
|
case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic |
|
RelocFuncs::rel32_unaligned(view, value); |
|
return ArmRelocFuncs::STATUS_OKAY; |
|
|
|
case elfcpp::R_ARM_TLS_IE32: // Initial-exec |
|
if (optimized_type == tls::TLSOPT_NONE) |
|
{ |
|
// Relocate the field with the offset of the GOT entry for |
|
// the tp-relative offset of the symbol. |
|
unsigned int got_type = GOT_TYPE_TLS_OFFSET; |
|
unsigned int got_offset; |
|
if (gsym != NULL) |
|
{ |
|
gold_assert(gsym->has_got_offset(got_type)); |
|
got_offset = gsym->got_offset(got_type); |
|
} |
|
else |
|
{ |
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); |
|
gold_assert(object->local_has_got_offset(r_sym, got_type)); |
|
got_offset = object->local_got_offset(r_sym, got_type); |
|
} |
|
|
|
// All GOT offsets are relative to the end of the GOT. |
|
got_offset -= target->got_size(); |
|
|
|
Arm_address got_entry = |
|
target->got_plt_section()->address() + got_offset; |
|
|
|
// Relocate the field with the PC relative offset of the GOT entry. |
|
RelocFuncs::pcrel32_unaligned(view, got_entry, address); |
|
return ArmRelocFuncs::STATUS_OKAY; |
|
} |
|
break; |
|
|
|
case elfcpp::R_ARM_TLS_LE32: // Local-exec |
|
// If we're creating a shared library, a dynamic relocation will |
|
// have been created for this location, so do not apply it now. |
|
if (!parameters->options().shared()) |
|
{ |
|
gold_assert(tls_segment != NULL); |
|
|
|
// $tp points to the TCB, which is followed by the TLS, so we |
|
// need to add TCB size to the offset. |
|
Arm_address aligned_tcb_size = |
|
align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment()); |
|
RelocFuncs::rel32_unaligned(view, value + aligned_tcb_size); |
|
|
|
} |
|
return ArmRelocFuncs::STATUS_OKAY; |
|
|
|
default: |
|
gold_unreachable(); |
|
} |
|
|
|
gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
|
_("unsupported reloc %u"), |
|
r_type); |
|
return ArmRelocFuncs::STATUS_BAD_RELOC; |
|
} |
|
|
|
// Relocate section data. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::relocate_section( |
|
const Relocate_info<32, big_endian>* relinfo, |
|
unsigned int sh_type, |
|
const unsigned char* prelocs, |
|
size_t reloc_count, |
|
Output_section* output_section, |
|
bool needs_special_offset_handling, |
|
unsigned char* view, |
|
Arm_address address, |
|
section_size_type view_size, |
|
const Reloc_symbol_changes* reloc_symbol_changes) |
|
{ |
|
typedef typename Target_arm<big_endian>::Relocate Arm_relocate; |
|
gold_assert(sh_type == elfcpp::SHT_REL); |
|
|
|
// See if we are relocating a relaxed input section. If so, the view |
|
// covers the whole output section and we need to adjust accordingly. |
|
if (needs_special_offset_handling) |
|
{ |
|
const Output_relaxed_input_section* poris = |
|
output_section->find_relaxed_input_section(relinfo->object, |
|
relinfo->data_shndx); |
|
if (poris != NULL) |
|
{ |
|
Arm_address section_address = poris->address(); |
|
section_size_type section_size = poris->data_size(); |
|
|
|
gold_assert((section_address >= address) |
|
&& ((section_address + section_size) |
|
<= (address + view_size))); |
|
|
|
off_t offset = section_address - address; |
|
view += offset; |
|
address += offset; |
|
view_size = section_size; |
|
} |
|
} |
|
|
|
gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL, |
|
Arm_relocate, gold::Default_comdat_behavior>( |
|
relinfo, |
|
this, |
|
prelocs, |
|
reloc_count, |
|
output_section, |
|
needs_special_offset_handling, |
|
view, |
|
address, |
|
view_size, |
|
reloc_symbol_changes); |
|
} |
|
|
|
// Return the size of a relocation while scanning during a relocatable |
|
// link. |
|
|
|
template<bool big_endian> |
|
unsigned int |
|
Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc( |
|
unsigned int r_type, |
|
Relobj* object) |
|
{ |
|
r_type = get_real_reloc_type(r_type); |
|
const Arm_reloc_property* arp = |
|
arm_reloc_property_table->get_implemented_static_reloc_property(r_type); |
|
if (arp != NULL) |
|
return arp->size(); |
|
else |
|
{ |
|
std::string reloc_name = |
|
arm_reloc_property_table->reloc_name_in_error_message(r_type); |
|
gold_error(_("%s: unexpected %s in object file"), |
|
object->name().c_str(), reloc_name.c_str()); |
|
return 0; |
|
} |
|
} |
|
|
|
// Scan the relocs during a relocatable link. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::scan_relocatable_relocs( |
|
Symbol_table* symtab, |
|
Layout* layout, |
|
Sized_relobj_file<32, big_endian>* object, |
|
unsigned int data_shndx, |
|
unsigned int sh_type, |
|
const unsigned char* prelocs, |
|
size_t reloc_count, |
|
Output_section* output_section, |
|
bool needs_special_offset_handling, |
|
size_t local_symbol_count, |
|
const unsigned char* plocal_symbols, |
|
Relocatable_relocs* rr) |
|
{ |
|
gold_assert(sh_type == elfcpp::SHT_REL); |
|
|
|
typedef Arm_scan_relocatable_relocs<big_endian, elfcpp::SHT_REL, |
|
Relocatable_size_for_reloc> Scan_relocatable_relocs; |
|
|
|
gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL, |
|
Scan_relocatable_relocs>( |
|
symtab, |
|
layout, |
|
object, |
|
data_shndx, |
|
prelocs, |
|
reloc_count, |
|
output_section, |
|
needs_special_offset_handling, |
|
local_symbol_count, |
|
plocal_symbols, |
|
rr); |
|
} |
|
|
|
// Emit relocations for a section. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::relocate_relocs( |
|
const Relocate_info<32, big_endian>* relinfo, |
|
unsigned int sh_type, |
|
const unsigned char* prelocs, |
|
size_t reloc_count, |
|
Output_section* output_section, |
|
typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section, |
|
const Relocatable_relocs* rr, |
|
unsigned char* view, |
|
Arm_address view_address, |
|
section_size_type view_size, |
|
unsigned char* reloc_view, |
|
section_size_type reloc_view_size) |
|
{ |
|
gold_assert(sh_type == elfcpp::SHT_REL); |
|
|
|
gold::relocate_relocs<32, big_endian, elfcpp::SHT_REL>( |
|
relinfo, |
|
prelocs, |
|
reloc_count, |
|
output_section, |
|
offset_in_output_section, |
|
rr, |
|
view, |
|
view_address, |
|
view_size, |
|
reloc_view, |
|
reloc_view_size); |
|
} |
|
|
|
// Perform target-specific processing in a relocatable link. This is |
|
// only used if we use the relocation strategy RELOC_SPECIAL. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::relocate_special_relocatable( |
|
const Relocate_info<32, big_endian>* relinfo, |
|
unsigned int sh_type, |
|
const unsigned char* preloc_in, |
|
size_t relnum, |
|
Output_section* output_section, |
|
typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section, |
|
unsigned char* view, |
|
elfcpp::Elf_types<32>::Elf_Addr view_address, |
|
section_size_type, |
|
unsigned char* preloc_out) |
|
{ |
|
// We can only handle REL type relocation sections. |
|
gold_assert(sh_type == elfcpp::SHT_REL); |
|
|
|
typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype; |
|
typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write |
|
Reltype_write; |
|
const Arm_address invalid_address = static_cast<Arm_address>(0) - 1; |
|
|
|
const Arm_relobj<big_endian>* object = |
|
Arm_relobj<big_endian>::as_arm_relobj(relinfo->object); |
|
const unsigned int local_count = object->local_symbol_count(); |
|
|
|
Reltype reloc(preloc_in); |
|
Reltype_write reloc_write(preloc_out); |
|
|
|
elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info(); |
|
const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info); |
|
const unsigned int r_type = elfcpp::elf_r_type<32>(r_info); |
|
|
|
const Arm_reloc_property* arp = |
|
arm_reloc_property_table->get_implemented_static_reloc_property(r_type); |
|
gold_assert(arp != NULL); |
|
|
|
// Get the new symbol index. |
|
// We only use RELOC_SPECIAL strategy in local relocations. |
|
gold_assert(r_sym < local_count); |
|
|
|
// We are adjusting a section symbol. We need to find |
|
// the symbol table index of the section symbol for |
|
// the output section corresponding to input section |
|
// in which this symbol is defined. |
|
bool is_ordinary; |
|
unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary); |
|
gold_assert(is_ordinary); |
|
Output_section* os = object->output_section(shndx); |
|
gold_assert(os != NULL); |
|
gold_assert(os->needs_symtab_index()); |
|
unsigned int new_symndx = os->symtab_index(); |
|
|
|
// Get the new offset--the location in the output section where |
|
// this relocation should be applied. |
|
|
|
Arm_address offset = reloc.get_r_offset(); |
|
Arm_address new_offset; |
|
if (offset_in_output_section != invalid_address) |
|
new_offset = offset + offset_in_output_section; |
|
else |
|
{ |
|
section_offset_type sot_offset = |
|
convert_types<section_offset_type, Arm_address>(offset); |
|
section_offset_type new_sot_offset = |
|
output_section->output_offset(object, relinfo->data_shndx, |
|
sot_offset); |
|
gold_assert(new_sot_offset != -1); |
|
new_offset = new_sot_offset; |
|
} |
|
|
|
// In an object file, r_offset is an offset within the section. |
|
// In an executable or dynamic object, generated by |
|
// --emit-relocs, r_offset is an absolute address. |
|
if (!parameters->options().relocatable()) |
|
{ |
|
new_offset += view_address; |
|
if (offset_in_output_section != invalid_address) |
|
new_offset -= offset_in_output_section; |
|
} |
|
|
|
reloc_write.put_r_offset(new_offset); |
|
reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type)); |
|
|
|
// Handle the reloc addend. |
|
// The relocation uses a section symbol in the input file. |
|
// We are adjusting it to use a section symbol in the output |
|
// file. The input section symbol refers to some address in |
|
// the input section. We need the relocation in the output |
|
// file to refer to that same address. This adjustment to |
|
// the addend is the same calculation we use for a simple |
|
// absolute relocation for the input section symbol. |
|
|
|
const Symbol_value<32>* psymval = object->local_symbol(r_sym); |
|
|
|
// Handle THUMB bit. |
|
Symbol_value<32> symval; |
|
Arm_address thumb_bit = |
|
object->local_symbol_is_thumb_function(r_sym) ? 1 : 0; |
|
if (thumb_bit != 0 |
|
&& arp->uses_thumb_bit() |
|
&& ((psymval->value(object, 0) & 1) != 0)) |
|
{ |
|
Arm_address stripped_value = |
|
psymval->value(object, 0) & ~static_cast<Arm_address>(1); |
|
symval.set_output_value(stripped_value); |
|
psymval = &symval; |
|
} |
|
|
|
unsigned char* paddend = view + offset; |
|
typename Arm_relocate_functions<big_endian>::Status reloc_status = |
|
Arm_relocate_functions<big_endian>::STATUS_OKAY; |
|
switch (r_type) |
|
{ |
|
case elfcpp::R_ARM_ABS8: |
|
reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object, |
|
psymval); |
|
break; |
|
|
|
case elfcpp::R_ARM_ABS12: |
|
reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object, |
|
psymval); |
|
break; |
|
|
|
case elfcpp::R_ARM_ABS16: |
|
reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object, |
|
psymval); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_ABS5: |
|
reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend, |
|
object, |
|
psymval); |
|
break; |
|
|
|
case elfcpp::R_ARM_MOVW_ABS_NC: |
|
case elfcpp::R_ARM_MOVW_PREL_NC: |
|
case elfcpp::R_ARM_MOVW_BREL_NC: |
|
case elfcpp::R_ARM_MOVW_BREL: |
|
reloc_status = Arm_relocate_functions<big_endian>::movw( |
|
paddend, object, psymval, 0, thumb_bit, arp->checks_overflow()); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_MOVW_ABS_NC: |
|
case elfcpp::R_ARM_THM_MOVW_PREL_NC: |
|
case elfcpp::R_ARM_THM_MOVW_BREL_NC: |
|
case elfcpp::R_ARM_THM_MOVW_BREL: |
|
reloc_status = Arm_relocate_functions<big_endian>::thm_movw( |
|
paddend, object, psymval, 0, thumb_bit, arp->checks_overflow()); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_CALL: |
|
case elfcpp::R_ARM_THM_XPC22: |
|
case elfcpp::R_ARM_THM_JUMP24: |
|
reloc_status = |
|
Arm_relocate_functions<big_endian>::thumb_branch_common( |
|
r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit, |
|
false); |
|
break; |
|
|
|
case elfcpp::R_ARM_PLT32: |
|
case elfcpp::R_ARM_CALL: |
|
case elfcpp::R_ARM_JUMP24: |
|
case elfcpp::R_ARM_XPC25: |
|
reloc_status = |
|
Arm_relocate_functions<big_endian>::arm_branch_common( |
|
r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit, |
|
false); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_JUMP19: |
|
reloc_status = |
|
Arm_relocate_functions<big_endian>::thm_jump19(paddend, object, |
|
psymval, 0, thumb_bit); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_JUMP6: |
|
reloc_status = |
|
Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval, |
|
0); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_JUMP8: |
|
reloc_status = |
|
Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval, |
|
0); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_JUMP11: |
|
reloc_status = |
|
Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval, |
|
0); |
|
break; |
|
|
|
case elfcpp::R_ARM_PREL31: |
|
reloc_status = |
|
Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0, |
|
thumb_bit); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_PC8: |
|
reloc_status = |
|
Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval, |
|
0); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_PC12: |
|
reloc_status = |
|
Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval, |
|
0); |
|
break; |
|
|
|
case elfcpp::R_ARM_THM_ALU_PREL_11_0: |
|
reloc_status = |
|
Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval, |
|
0, thumb_bit); |
|
break; |
|
|
|
// These relocation truncate relocation results so we cannot handle them |
|
// in a relocatable link. |
|
case elfcpp::R_ARM_MOVT_ABS: |
|
case elfcpp::R_ARM_THM_MOVT_ABS: |
|
case elfcpp::R_ARM_MOVT_PREL: |
|
case elfcpp::R_ARM_MOVT_BREL: |
|
case elfcpp::R_ARM_THM_MOVT_PREL: |
|
case elfcpp::R_ARM_THM_MOVT_BREL: |
|
case elfcpp::R_ARM_ALU_PC_G0_NC: |
|
case elfcpp::R_ARM_ALU_PC_G0: |
|
case elfcpp::R_ARM_ALU_PC_G1_NC: |
|
case elfcpp::R_ARM_ALU_PC_G1: |
|
case elfcpp::R_ARM_ALU_PC_G2: |
|
case elfcpp::R_ARM_ALU_SB_G0_NC: |
|
case elfcpp::R_ARM_ALU_SB_G0: |
|
case elfcpp::R_ARM_ALU_SB_G1_NC: |
|
case elfcpp::R_ARM_ALU_SB_G1: |
|
case elfcpp::R_ARM_ALU_SB_G2: |
|
case elfcpp::R_ARM_LDR_PC_G0: |
|
case elfcpp::R_ARM_LDR_PC_G1: |
|
case elfcpp::R_ARM_LDR_PC_G2: |
|
case elfcpp::R_ARM_LDR_SB_G0: |
|
case elfcpp::R_ARM_LDR_SB_G1: |
|
case elfcpp::R_ARM_LDR_SB_G2: |
|
case elfcpp::R_ARM_LDRS_PC_G0: |
|
case elfcpp::R_ARM_LDRS_PC_G1: |
|
case elfcpp::R_ARM_LDRS_PC_G2: |
|
case elfcpp::R_ARM_LDRS_SB_G0: |
|
case elfcpp::R_ARM_LDRS_SB_G1: |
|
case elfcpp::R_ARM_LDRS_SB_G2: |
|
case elfcpp::R_ARM_LDC_PC_G0: |
|
case elfcpp::R_ARM_LDC_PC_G1: |
|
case elfcpp::R_ARM_LDC_PC_G2: |
|
case elfcpp::R_ARM_LDC_SB_G0: |
|
case elfcpp::R_ARM_LDC_SB_G1: |
|
case elfcpp::R_ARM_LDC_SB_G2: |
|
gold_error(_("cannot handle %s in a relocatable link"), |
|
arp->name().c_str()); |
|
break; |
|
|
|
default: |
|
gold_unreachable(); |
|
} |
|
|
|
// Report any errors. |
|
switch (reloc_status) |
|
{ |
|
case Arm_relocate_functions<big_endian>::STATUS_OKAY: |
|
break; |
|
case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW: |
|
gold_error_at_location(relinfo, relnum, reloc.get_r_offset(), |
|
_("relocation overflow in %s"), |
|
arp->name().c_str()); |
|
break; |
|
case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC: |
|
gold_error_at_location(relinfo, relnum, reloc.get_r_offset(), |
|
_("unexpected opcode while processing relocation %s"), |
|
arp->name().c_str()); |
|
break; |
|
default: |
|
gold_unreachable(); |
|
} |
|
} |
|
|
|
// Return the value to use for a dynamic symbol which requires special |
|
// treatment. This is how we support equality comparisons of function |
|
// pointers across shared library boundaries, as described in the |
|
// processor specific ABI supplement. |
|
|
|
template<bool big_endian> |
|
uint64_t |
|
Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const |
|
{ |
|
gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset()); |
|
return this->plt_address_for_global(gsym); |
|
} |
|
|
|
// Map platform-specific relocs to real relocs |
|
// |
|
template<bool big_endian> |
|
unsigned int |
|
Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type) |
|
{ |
|
switch (r_type) |
|
{ |
|
case elfcpp::R_ARM_TARGET1: |
|
// This is either R_ARM_ABS32 or R_ARM_REL32; |
|
return elfcpp::R_ARM_ABS32; |
|
|
|
case elfcpp::R_ARM_TARGET2: |
|
// This can be any reloc type but usually is R_ARM_GOT_PREL |
|
return elfcpp::R_ARM_GOT_PREL; |
|
|
|
default: |
|
return r_type; |
|
} |
|
} |
|
|
|
// Whether if two EABI versions V1 and V2 are compatible. |
|
|
|
template<bool big_endian> |
|
bool |
|
Target_arm<big_endian>::are_eabi_versions_compatible( |
|
elfcpp::Elf_Word v1, |
|
elfcpp::Elf_Word v2) |
|
{ |
|
// v4 and v5 are the same spec before and after it was released, |
|
// so allow mixing them. |
|
if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN) |
|
|| (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5) |
|
|| (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4)) |
|
return true; |
|
|
|
return v1 == v2; |
|
} |
|
|
|
// Combine FLAGS from an input object called NAME and the processor-specific |
|
// flags in the ELF header of the output. Much of this is adapted from the |
|
// processor-specific flags merging code in elf32_arm_merge_private_bfd_data |
|
// in bfd/elf32-arm.c. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::merge_processor_specific_flags( |
|
const std::string& name, |
|
elfcpp::Elf_Word flags) |
|
{ |
|
if (this->are_processor_specific_flags_set()) |
|
{ |
|
elfcpp::Elf_Word out_flags = this->processor_specific_flags(); |
|
|
|
// Nothing to merge if flags equal to those in output. |
|
if (flags == out_flags) |
|
return; |
|
|
|
// Complain about various flag mismatches. |
|
elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags); |
|
elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags); |
|
if (!this->are_eabi_versions_compatible(version1, version2) |
|
&& parameters->options().warn_mismatch()) |
|
gold_error(_("Source object %s has EABI version %d but output has " |
|
"EABI version %d."), |
|
name.c_str(), |
|
(flags & elfcpp::EF_ARM_EABIMASK) >> 24, |
|
(out_flags & elfcpp::EF_ARM_EABIMASK) >> 24); |
|
} |
|
else |
|
{ |
|
// If the input is the default architecture and had the default |
|
// flags then do not bother setting the flags for the output |
|
// architecture, instead allow future merges to do this. If no |
|
// future merges ever set these flags then they will retain their |
|
// uninitialised values, which surprise surprise, correspond |
|
// to the default values. |
|
if (flags == 0) |
|
return; |
|
|
|
// This is the first time, just copy the flags. |
|
// We only copy the EABI version for now. |
|
this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK); |
|
} |
|
} |
|
|
|
// Adjust ELF file header. |
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::do_adjust_elf_header( |
|
unsigned char* view, |
|
int len) |
|
{ |
|
gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size); |
|
|
|
elfcpp::Ehdr<32, big_endian> ehdr(view); |
|
elfcpp::Elf_Word flags = this->processor_specific_flags(); |
|
unsigned char e_ident[elfcpp::EI_NIDENT]; |
|
memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT); |
|
|
|
if (elfcpp::arm_eabi_version(flags) |
|
== elfcpp::EF_ARM_EABI_UNKNOWN) |
|
e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM; |
|
else |
|
e_ident[elfcpp::EI_OSABI] = 0; |
|
e_ident[elfcpp::EI_ABIVERSION] = 0; |
|
|
|
// FIXME: Do EF_ARM_BE8 adjustment. |
|
|
|
// If we're working in EABI_VER5, set the hard/soft float ABI flags |
|
// as appropriate. |
|
if (elfcpp::arm_eabi_version(flags) == elfcpp::EF_ARM_EABI_VER5) |
|
{ |
|
elfcpp::Elf_Half type = ehdr.get_e_type(); |
|
if (type == elfcpp::ET_EXEC || type == elfcpp::ET_DYN) |
|
{ |
|
Object_attribute* attr = this->get_aeabi_object_attribute(elfcpp::Tag_ABI_VFP_args); |
|
if (attr->int_value() == elfcpp::AEABI_VFP_args_vfp) |
|
flags |= elfcpp::EF_ARM_ABI_FLOAT_HARD; |
|
else |
|
flags |= elfcpp::EF_ARM_ABI_FLOAT_SOFT; |
|
this->set_processor_specific_flags(flags); |
|
} |
|
} |
|
elfcpp::Ehdr_write<32, big_endian> oehdr(view); |
|
oehdr.put_e_ident(e_ident); |
|
oehdr.put_e_flags(this->processor_specific_flags()); |
|
} |
|
|
|
// do_make_elf_object to override the same function in the base class. |
|
// We need to use a target-specific sub-class of |
|
// Sized_relobj_file<32, big_endian> to store ARM specific information. |
|
// Hence we need to have our own ELF object creation. |
|
|
|
template<bool big_endian> |
|
Object* |
|
Target_arm<big_endian>::do_make_elf_object( |
|
const std::string& name, |
|
Input_file* input_file, |
|
off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr) |
|
{ |
|
int et = ehdr.get_e_type(); |
|
// ET_EXEC files are valid input for --just-symbols/-R, |
|
// and we treat them as relocatable objects. |
|
if (et == elfcpp::ET_REL |
|
|| (et == elfcpp::ET_EXEC && input_file->just_symbols())) |
|
{ |
|
Arm_relobj<big_endian>* obj = |
|
new Arm_relobj<big_endian>(name, input_file, offset, ehdr); |
|
obj->setup(); |
|
return obj; |
|
} |
|
else if (et == elfcpp::ET_DYN) |
|
{ |
|
Sized_dynobj<32, big_endian>* obj = |
|
new Arm_dynobj<big_endian>(name, input_file, offset, ehdr); |
|
obj->setup(); |
|
return obj; |
|
} |
|
else |
|
{ |
|
gold_error(_("%s: unsupported ELF file type %d"), |
|
name.c_str(), et); |
|
return NULL; |
|
} |
|
} |
|
|
|
// Read the architecture from the Tag_also_compatible_with attribute, if any. |
|
// Returns -1 if no architecture could be read. |
|
// This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c. |
|
|
|
template<bool big_endian> |
|
int |
|
Target_arm<big_endian>::get_secondary_compatible_arch( |
|
const Attributes_section_data* pasd) |
|
{ |
|
const Object_attribute* known_attributes = |
|
pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC); |
|
|
|
// Note: the tag and its argument below are uleb128 values, though |
|
// currently-defined values fit in one byte for each. |
|
const std::string& sv = |
|
known_attributes[elfcpp::Tag_also_compatible_with].string_value(); |
|
if (sv.size() == 2 |
|
&& sv.data()[0] == elfcpp::Tag_CPU_arch |
|
&& (sv.data()[1] & 128) != 128) |
|
return sv.data()[1]; |
|
|
|
// This tag is "safely ignorable", so don't complain if it looks funny. |
|
return -1; |
|
} |
|
|
|
// Set, or unset, the architecture of the Tag_also_compatible_with attribute. |
|
// The tag is removed if ARCH is -1. |
|
// This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::set_secondary_compatible_arch( |
|
Attributes_section_data* pasd, |
|
int arch) |
|
{ |
|
Object_attribute* known_attributes = |
|
pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC); |
|
|
|
if (arch == -1) |
|
{ |
|
known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(""); |
|
return; |
|
} |
|
|
|
// Note: the tag and its argument below are uleb128 values, though |
|
// currently-defined values fit in one byte for each. |
|
char sv[3]; |
|
sv[0] = elfcpp::Tag_CPU_arch; |
|
gold_assert(arch != 0); |
|
sv[1] = arch; |
|
sv[2] = '\0'; |
|
|
|
known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv); |
|
} |
|
|
|
// Combine two values for Tag_CPU_arch, taking secondary compatibility tags |
|
// into account. |
|
// This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c. |
|
|
|
template<bool big_endian> |
|
int |
|
Target_arm<big_endian>::tag_cpu_arch_combine( |
|
const char* name, |
|
int oldtag, |
|
int* secondary_compat_out, |
|
int newtag, |
|
int secondary_compat) |
|
{ |
|
#define T(X) elfcpp::TAG_CPU_ARCH_##X |
|
static const int v6t2[] = |
|
{ |
|
T(V6T2), // PRE_V4. |
|
T(V6T2), // V4. |
|
T(V6T2), // V4T. |
|
T(V6T2), // V5T. |
|
T(V6T2), // V5TE. |
|
T(V6T2), // V5TEJ. |
|
T(V6T2), // V6. |
|
T(V7), // V6KZ. |
|
T(V6T2) // V6T2. |
|
}; |
|
static const int v6k[] = |
|
{ |
|
T(V6K), // PRE_V4. |
|
T(V6K), // V4. |
|
T(V6K), // V4T. |
|
T(V6K), // V5T. |
|
T(V6K), // V5TE. |
|
T(V6K), // V5TEJ. |
|
T(V6K), // V6. |
|
T(V6KZ), // V6KZ. |
|
T(V7), // V6T2. |
|
T(V6K) // V6K. |
|
}; |
|
static const int v7[] = |
|
{ |
|
T(V7), // PRE_V4. |
|
T(V7), // V4. |
|
T(V7), // V4T. |
|
T(V7), // V5T. |
|
T(V7), // V5TE. |
|
T(V7), // V5TEJ. |
|
T(V7), // V6. |
|
T(V7), // V6KZ. |
|
T(V7), // V6T2. |
|
T(V7), // V6K. |
|
T(V7) // V7. |
|
}; |
|
static const int v6_m[] = |
|
{ |
|
-1, // PRE_V4. |
|
-1, // V4. |
|
T(V6K), // V4T. |
|
T(V6K), // V5T. |
|
T(V6K), // V5TE. |
|
T(V6K), // V5TEJ. |
|
T(V6K), // V6. |
|
T(V6KZ), // V6KZ. |
|
T(V7), // V6T2. |
|
T(V6K), // V6K. |
|
T(V7), // V7. |
|
T(V6_M) // V6_M. |
|
}; |
|
static const int v6s_m[] = |
|
{ |
|
-1, // PRE_V4. |
|
-1, // V4. |
|
T(V6K), // V4T. |
|
T(V6K), // V5T. |
|
T(V6K), // V5TE. |
|
T(V6K), // V5TEJ. |
|
T(V6K), // V6. |
|
T(V6KZ), // V6KZ. |
|
T(V7), // V6T2. |
|
T(V6K), // V6K. |
|
T(V7), // V7. |
|
T(V6S_M), // V6_M. |
|
T(V6S_M) // V6S_M. |
|
}; |
|
static const int v7e_m[] = |
|
{ |
|
-1, // PRE_V4. |
|
-1, // V4. |
|
T(V7E_M), // V4T. |
|
T(V7E_M), // V5T. |
|
T(V7E_M), // V5TE. |
|
T(V7E_M), // V5TEJ. |
|
T(V7E_M), // V6. |
|
T(V7E_M), // V6KZ. |
|
T(V7E_M), // V6T2. |
|
T(V7E_M), // V6K. |
|
T(V7E_M), // V7. |
|
T(V7E_M), // V6_M. |
|
T(V7E_M), // V6S_M. |
|
T(V7E_M) // V7E_M. |
|
}; |
|
static const int v8[] = |
|
{ |
|
T(V8), // PRE_V4. |
|
T(V8), // V4. |
|
T(V8), // V4T. |
|
T(V8), // V5T. |
|
T(V8), // V5TE. |
|
T(V8), // V5TEJ. |
|
T(V8), // V6. |
|
T(V8), // V6KZ. |
|
T(V8), // V6T2. |
|
T(V8), // V6K. |
|
T(V8), // V7. |
|
T(V8), // V6_M. |
|
T(V8), // V6S_M. |
|
T(V8), // V7E_M. |
|
T(V8) // V8. |
|
}; |
|
static const int v4t_plus_v6_m[] = |
|
{ |
|
-1, // PRE_V4. |
|
-1, // V4. |
|
T(V4T), // V4T. |
|
T(V5T), // V5T. |
|
T(V5TE), // V5TE. |
|
T(V5TEJ), // V5TEJ. |
|
T(V6), // V6. |
|
T(V6KZ), // V6KZ. |
|
T(V6T2), // V6T2. |
|
T(V6K), // V6K. |
|
T(V7), // V7. |
|
T(V6_M), // V6_M. |
|
T(V6S_M), // V6S_M. |
|
T(V7E_M), // V7E_M. |
|
T(V8), // V8. |
|
T(V4T_PLUS_V6_M) // V4T plus V6_M. |
|
}; |
|
static const int* comb[] = |
|
{ |
|
v6t2, |
|
v6k, |
|
v7, |
|
v6_m, |
|
v6s_m, |
|
v7e_m, |
|
v8, |
|
// Pseudo-architecture. |
|
v4t_plus_v6_m |
|
}; |
|
|
|
// Check we've not got a higher architecture than we know about. |
|
|
|
if (oldtag > elfcpp::MAX_TAG_CPU_ARCH || newtag > elfcpp::MAX_TAG_CPU_ARCH) |
|
{ |
|
gold_error(_("%s: unknown CPU architecture"), name); |
|
return -1; |
|
} |
|
|
|
// Override old tag if we have a Tag_also_compatible_with on the output. |
|
|
|
if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T)) |
|
|| (oldtag == T(V4T) && *secondary_compat_out == T(V6_M))) |
|
oldtag = T(V4T_PLUS_V6_M); |
|
|
|
// And override the new tag if we have a Tag_also_compatible_with on the |
|
// input. |
|
|
|
if ((newtag == T(V6_M) && secondary_compat == T(V4T)) |
|
|| (newtag == T(V4T) && secondary_compat == T(V6_M))) |
|
newtag = T(V4T_PLUS_V6_M); |
|
|
|
// Architectures before V6KZ add features monotonically. |
|
int tagh = std::max(oldtag, newtag); |
|
if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ) |
|
return tagh; |
|
|
|
int tagl = std::min(oldtag, newtag); |
|
int result = comb[tagh - T(V6T2)][tagl]; |
|
|
|
// Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M) |
|
// as the canonical version. |
|
if (result == T(V4T_PLUS_V6_M)) |
|
{ |
|
result = T(V4T); |
|
*secondary_compat_out = T(V6_M); |
|
} |
|
else |
|
*secondary_compat_out = -1; |
|
|
|
if (result == -1) |
|
{ |
|
gold_error(_("%s: conflicting CPU architectures %d/%d"), |
|
name, oldtag, newtag); |
|
return -1; |
|
} |
|
|
|
return result; |
|
#undef T |
|
} |
|
|
|
// Helper to print AEABI enum tag value. |
|
|
|
template<bool big_endian> |
|
std::string |
|
Target_arm<big_endian>::aeabi_enum_name(unsigned int value) |
|
{ |
|
static const char* aeabi_enum_names[] = |
|
{ "", "variable-size", "32-bit", "" }; |
|
const size_t aeabi_enum_names_size = |
|
sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]); |
|
|
|
if (value < aeabi_enum_names_size) |
|
return std::string(aeabi_enum_names[value]); |
|
else |
|
{ |
|
char buffer[100]; |
|
sprintf(buffer, "<unknown value %u>", value); |
|
return std::string(buffer); |
|
} |
|
} |
|
|
|
// Return the string value to store in TAG_CPU_name. |
|
|
|
template<bool big_endian> |
|
std::string |
|
Target_arm<big_endian>::tag_cpu_name_value(unsigned int value) |
|
{ |
|
static const char* name_table[] = { |
|
// These aren't real CPU names, but we can't guess |
|
// that from the architecture version alone. |
|
"Pre v4", |
|
"ARM v4", |
|
"ARM v4T", |
|
"ARM v5T", |
|
"ARM v5TE", |
|
"ARM v5TEJ", |
|
"ARM v6", |
|
"ARM v6KZ", |
|
"ARM v6T2", |
|
"ARM v6K", |
|
"ARM v7", |
|
"ARM v6-M", |
|
"ARM v6S-M", |
|
"ARM v7E-M", |
|
"ARM v8" |
|
}; |
|
const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]); |
|
|
|
if (value < name_table_size) |
|
return std::string(name_table[value]); |
|
else |
|
{ |
|
char buffer[100]; |
|
sprintf(buffer, "<unknown CPU value %u>", value); |
|
return std::string(buffer); |
|
} |
|
} |
|
|
|
// Query attributes object to see if integer divide instructions may be |
|
// present in an object. |
|
|
|
template<bool big_endian> |
|
bool |
|
Target_arm<big_endian>::attributes_accept_div(int arch, int profile, |
|
const Object_attribute* div_attr) |
|
{ |
|
switch (div_attr->int_value()) |
|
{ |
|
case 0: |
|
// Integer divide allowed if instruction contained in |
|
// archetecture. |
|
if (arch == elfcpp::TAG_CPU_ARCH_V7 && (profile == 'R' || profile == 'M')) |
|
return true; |
|
else if (arch >= elfcpp::TAG_CPU_ARCH_V7E_M) |
|
return true; |
|
else |
|
return false; |
|
|
|
case 1: |
|
// Integer divide explicitly prohibited. |
|
return false; |
|
|
|
default: |
|
// Unrecognised case - treat as allowing divide everywhere. |
|
case 2: |
|
// Integer divide allowed in ARM state. |
|
return true; |
|
} |
|
} |
|
|
|
// Query attributes object to see if integer divide instructions are |
|
// forbidden to be in the object. This is not the inverse of |
|
// attributes_accept_div. |
|
|
|
template<bool big_endian> |
|
bool |
|
Target_arm<big_endian>::attributes_forbid_div(const Object_attribute* div_attr) |
|
{ |
|
return div_attr->int_value() == 1; |
|
} |
|
|
|
// Merge object attributes from input file called NAME with those of the |
|
// output. The input object attributes are in the object pointed by PASD. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::merge_object_attributes( |
|
const char* name, |
|
const Attributes_section_data* pasd) |
|
{ |
|
// Return if there is no attributes section data. |
|
if (pasd == NULL) |
|
return; |
|
|
|
// If output has no object attributes, just copy. |
|
const int vendor = Object_attribute::OBJ_ATTR_PROC; |
|
if (this->attributes_section_data_ == NULL) |
|
{ |
|
this->attributes_section_data_ = new Attributes_section_data(*pasd); |
|
Object_attribute* out_attr = |
|
this->attributes_section_data_->known_attributes(vendor); |
|
|
|
// We do not output objects with Tag_MPextension_use_legacy - we move |
|
// the attribute's value to Tag_MPextension_use. */ |
|
if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0) |
|
{ |
|
if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0 |
|
&& out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() |
|
!= out_attr[elfcpp::Tag_MPextension_use].int_value()) |
|
{ |
|
gold_error(_("%s has both the current and legacy " |
|
"Tag_MPextension_use attributes"), |
|
name); |
|
} |
|
|
|
out_attr[elfcpp::Tag_MPextension_use] = |
|
out_attr[elfcpp::Tag_MPextension_use_legacy]; |
|
out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0); |
|
out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0); |
|
} |
|
|
|
return; |
|
} |
|
|
|
const Object_attribute* in_attr = pasd->known_attributes(vendor); |
|
Object_attribute* out_attr = |
|
this->attributes_section_data_->known_attributes(vendor); |
|
|
|
// This needs to happen before Tag_ABI_FP_number_model is merged. */ |
|
if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value() |
|
!= out_attr[elfcpp::Tag_ABI_VFP_args].int_value()) |
|
{ |
|
// Ignore mismatches if the object doesn't use floating point. */ |
|
if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value() |
|
== elfcpp::AEABI_FP_number_model_none |
|
|| (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() |
|
!= elfcpp::AEABI_FP_number_model_none |
|
&& out_attr[elfcpp::Tag_ABI_VFP_args].int_value() |
|
== elfcpp::AEABI_VFP_args_compatible)) |
|
out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value( |
|
in_attr[elfcpp::Tag_ABI_VFP_args].int_value()); |
|
else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() |
|
!= elfcpp::AEABI_FP_number_model_none |
|
&& in_attr[elfcpp::Tag_ABI_VFP_args].int_value() |
|
!= elfcpp::AEABI_VFP_args_compatible |
|
&& parameters->options().warn_mismatch()) |
|
gold_error(_("%s uses VFP register arguments, output does not"), |
|
name); |
|
} |
|
|
|
for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i) |
|
{ |
|
// Merge this attribute with existing attributes. |
|
switch (i) |
|
{ |
|
case elfcpp::Tag_CPU_raw_name: |
|
case elfcpp::Tag_CPU_name: |
|
// These are merged after Tag_CPU_arch. |
|
break; |
|
|
|
case elfcpp::Tag_ABI_optimization_goals: |
|
case elfcpp::Tag_ABI_FP_optimization_goals: |
|
// Use the first value seen. |
|
break; |
|
|
|
case elfcpp::Tag_CPU_arch: |
|
{ |
|
unsigned int saved_out_attr = out_attr->int_value(); |
|
// Merge Tag_CPU_arch and Tag_also_compatible_with. |
|
int secondary_compat = |
|
this->get_secondary_compatible_arch(pasd); |
|
int secondary_compat_out = |
|
this->get_secondary_compatible_arch( |
|
this->attributes_section_data_); |
|
out_attr[i].set_int_value( |
|
tag_cpu_arch_combine(name, out_attr[i].int_value(), |
|
&secondary_compat_out, |
|
in_attr[i].int_value(), |
|
secondary_compat)); |
|
this->set_secondary_compatible_arch(this->attributes_section_data_, |
|
secondary_compat_out); |
|
|
|
// Merge Tag_CPU_name and Tag_CPU_raw_name. |
|
if (out_attr[i].int_value() == saved_out_attr) |
|
; // Leave the names alone. |
|
else if (out_attr[i].int_value() == in_attr[i].int_value()) |
|
{ |
|
// The output architecture has been changed to match the |
|
// input architecture. Use the input names. |
|
out_attr[elfcpp::Tag_CPU_name].set_string_value( |
|
in_attr[elfcpp::Tag_CPU_name].string_value()); |
|
out_attr[elfcpp::Tag_CPU_raw_name].set_string_value( |
|
in_attr[elfcpp::Tag_CPU_raw_name].string_value()); |
|
} |
|
else |
|
{ |
|
out_attr[elfcpp::Tag_CPU_name].set_string_value(""); |
|
out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(""); |
|
} |
|
|
|
// If we still don't have a value for Tag_CPU_name, |
|
// make one up now. Tag_CPU_raw_name remains blank. |
|
if (out_attr[elfcpp::Tag_CPU_name].string_value() == "") |
|
{ |
|
const std::string cpu_name = |
|
this->tag_cpu_name_value(out_attr[i].int_value()); |
|
// FIXME: If we see an unknown CPU, this will be set |
|
// to "<unknown CPU n>", where n is the attribute value. |
|
// This is different from BFD, which leaves the name alone. |
|
out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name); |
|
} |
|
} |
|
break; |
|
|
|
case elfcpp::Tag_ARM_ISA_use: |
|
case elfcpp::Tag_THUMB_ISA_use: |
|
case elfcpp::Tag_WMMX_arch: |
|
case elfcpp::Tag_Advanced_SIMD_arch: |
|
// ??? Do Advanced_SIMD (NEON) and WMMX conflict? |
|
case elfcpp::Tag_ABI_FP_rounding: |
|
case elfcpp::Tag_ABI_FP_exceptions: |
|
case elfcpp::Tag_ABI_FP_user_exceptions: |
|
case elfcpp::Tag_ABI_FP_number_model: |
|
case elfcpp::Tag_VFP_HP_extension: |
|
case elfcpp::Tag_CPU_unaligned_access: |
|
case elfcpp::Tag_T2EE_use: |
|
case elfcpp::Tag_Virtualization_use: |
|
case elfcpp::Tag_MPextension_use: |
|
// Use the largest value specified. |
|
if (in_attr[i].int_value() > out_attr[i].int_value()) |
|
out_attr[i].set_int_value(in_attr[i].int_value()); |
|
break; |
|
|
|
case elfcpp::Tag_ABI_align8_preserved: |
|
case elfcpp::Tag_ABI_PCS_RO_data: |
|
// Use the smallest value specified. |
|
if (in_attr[i].int_value() < out_attr[i].int_value()) |
|
out_attr[i].set_int_value(in_attr[i].int_value()); |
|
break; |
|
|
|
case elfcpp::Tag_ABI_align8_needed: |
|
if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0) |
|
&& (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0 |
|
|| (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value() |
|
== 0))) |
|
{ |
|
// This error message should be enabled once all non-conforming |
|
// binaries in the toolchain have had the attributes set |
|
// properly. |
|
// gold_error(_("output 8-byte data alignment conflicts with %s"), |
|
// name); |
|
} |
|
// Fall through. |
|
case elfcpp::Tag_ABI_FP_denormal: |
|
case elfcpp::Tag_ABI_PCS_GOT_use: |
|
{ |
|
// These tags have 0 = don't care, 1 = strong requirement, |
|
// 2 = weak requirement. |
|
static const int order_021[3] = {0, 2, 1}; |
|
|
|
// Use the "greatest" from the sequence 0, 2, 1, or the largest |
|
// value if greater than 2 (for future-proofing). |
|
if ((in_attr[i].int_value() > 2 |
|
&& in_attr[i].int_value() > out_attr[i].int_value()) |
|
|| (in_attr[i].int_value() <= 2 |
|
&& out_attr[i].int_value() <= 2 |
|
&& (order_021[in_attr[i].int_value()] |
|
> order_021[out_attr[i].int_value()]))) |
|
out_attr[i].set_int_value(in_attr[i].int_value()); |
|
} |
|
break; |
|
|
|
case elfcpp::Tag_CPU_arch_profile: |
|
if (out_attr[i].int_value() != in_attr[i].int_value()) |
|
{ |
|
// 0 will merge with anything. |
|
// 'A' and 'S' merge to 'A'. |
|
// 'R' and 'S' merge to 'R'. |
|
// 'M' and 'A|R|S' is an error. |
|
if (out_attr[i].int_value() == 0 |
|
|| (out_attr[i].int_value() == 'S' |
|
&& (in_attr[i].int_value() == 'A' |
|
|| in_attr[i].int_value() == 'R'))) |
|
out_attr[i].set_int_value(in_attr[i].int_value()); |
|
else if (in_attr[i].int_value() == 0 |
|
|| (in_attr[i].int_value() == 'S' |
|
&& (out_attr[i].int_value() == 'A' |
|
|| out_attr[i].int_value() == 'R'))) |
|
; // Do nothing. |
|
else if (parameters->options().warn_mismatch()) |
|
{ |
|
gold_error |
|
(_("conflicting architecture profiles %c/%c"), |
|
in_attr[i].int_value() ? in_attr[i].int_value() : '0', |
|
out_attr[i].int_value() ? out_attr[i].int_value() : '0'); |
|
} |
|
} |
|
break; |
|
case elfcpp::Tag_VFP_arch: |
|
{ |
|
static const struct |
|
{ |
|
int ver; |
|
int regs; |
|
} vfp_versions[7] = |
|
{ |
|
{0, 0}, |
|
{1, 16}, |
|
{2, 16}, |
|
{3, 32}, |
|
{3, 16}, |
|
{4, 32}, |
|
{4, 16} |
|
}; |
|
|
|
// Values greater than 6 aren't defined, so just pick the |
|
// biggest. |
|
if (in_attr[i].int_value() > 6 |
|
&& in_attr[i].int_value() > out_attr[i].int_value()) |
|
{ |
|
*out_attr = *in_attr; |
|
break; |
|
} |
|
// The output uses the superset of input features |
|
// (ISA version) and registers. |
|
int ver = std::max(vfp_versions[in_attr[i].int_value()].ver, |
|
vfp_versions[out_attr[i].int_value()].ver); |
|
int regs = std::max(vfp_versions[in_attr[i].int_value()].regs, |
|
vfp_versions[out_attr[i].int_value()].regs); |
|
// This assumes all possible supersets are also a valid |
|
// options. |
|
int newval; |
|
for (newval = 6; newval > 0; newval--) |
|
{ |
|
if (regs == vfp_versions[newval].regs |
|
&& ver == vfp_versions[newval].ver) |
|
break; |
|
} |
|
out_attr[i].set_int_value(newval); |
|
} |
|
break; |
|
case elfcpp::Tag_PCS_config: |
|
if (out_attr[i].int_value() == 0) |
|
out_attr[i].set_int_value(in_attr[i].int_value()); |
|
else if (in_attr[i].int_value() != 0 |
|
&& out_attr[i].int_value() != 0 |
|
&& parameters->options().warn_mismatch()) |
|
{ |
|
// It's sometimes ok to mix different configs, so this is only |
|
// a warning. |
|
gold_warning(_("%s: conflicting platform configuration"), name); |
|
} |
|
break; |
|
case elfcpp::Tag_ABI_PCS_R9_use: |
|
if (in_attr[i].int_value() != out_attr[i].int_value() |
|
&& out_attr[i].int_value() != elfcpp::AEABI_R9_unused |
|
&& in_attr[i].int_value() != elfcpp::AEABI_R9_unused |
|
&& parameters->options().warn_mismatch()) |
|
{ |
|
gold_error(_("%s: conflicting use of R9"), name); |
|
} |
|
if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused) |
|
out_attr[i].set_int_value(in_attr[i].int_value()); |
|
break; |
|
case elfcpp::Tag_ABI_PCS_RW_data: |
|
if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel |
|
&& (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value() |
|
!= elfcpp::AEABI_R9_SB) |
|
&& (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value() |
|
!= elfcpp::AEABI_R9_unused) |
|
&& parameters->options().warn_mismatch()) |
|
{ |
|
gold_error(_("%s: SB relative addressing conflicts with use " |
|
"of R9"), |
|
name); |
|
} |
|
// Use the smallest value specified. |
|
if (in_attr[i].int_value() < out_attr[i].int_value()) |
|
out_attr[i].set_int_value(in_attr[i].int_value()); |
|
break; |
|
case elfcpp::Tag_ABI_PCS_wchar_t: |
|
if (out_attr[i].int_value() |
|
&& in_attr[i].int_value() |
|
&& out_attr[i].int_value() != in_attr[i].int_value() |
|
&& parameters->options().warn_mismatch() |
|
&& parameters->options().wchar_size_warning()) |
|
{ |
|
gold_warning(_("%s uses %u-byte wchar_t yet the output is to " |
|
"use %u-byte wchar_t; use of wchar_t values " |
|
"across objects may fail"), |
|
name, in_attr[i].int_value(), |
|
out_attr[i].int_value()); |
|
} |
|
else if (in_attr[i].int_value() && !out_attr[i].int_value()) |
|
out_attr[i].set_int_value(in_attr[i].int_value()); |
|
break; |
|
case elfcpp::Tag_ABI_enum_size: |
|
if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused) |
|
{ |
|
if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused |
|
|| out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide) |
|
{ |
|
// The existing object is compatible with anything. |
|
// Use whatever requirements the new object has. |
|
out_attr[i].set_int_value(in_attr[i].int_value()); |
|
} |
|
else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide |
|
&& out_attr[i].int_value() != in_attr[i].int_value() |
|
&& parameters->options().warn_mismatch() |
|
&& parameters->options().enum_size_warning()) |
|
{ |
|
unsigned int in_value = in_attr[i].int_value(); |
|
unsigned int out_value = out_attr[i].int_value(); |
|
gold_warning(_("%s uses %s enums yet the output is to use " |
|
"%s enums; use of enum values across objects " |
|
"may fail"), |
|
name, |
|
this->aeabi_enum_name(in_value).c_str(), |
|
this->aeabi_enum_name(out_value).c_str()); |
|
} |
|
} |
|
break; |
|
case elfcpp::Tag_ABI_VFP_args: |
|
// Already done. |
|
break; |
|
case elfcpp::Tag_ABI_WMMX_args: |
|
if (in_attr[i].int_value() != out_attr[i].int_value() |
|
&& parameters->options().warn_mismatch()) |
|
{ |
|
gold_error(_("%s uses iWMMXt register arguments, output does " |
|
"not"), |
|
name); |
|
} |
|
break; |
|
case Object_attribute::Tag_compatibility: |
|
// Merged in target-independent code. |
|
break; |
|
case elfcpp::Tag_ABI_HardFP_use: |
|
// 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP). |
|
if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2) |
|
|| (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1)) |
|
out_attr[i].set_int_value(3); |
|
else if (in_attr[i].int_value() > out_attr[i].int_value()) |
|
out_attr[i].set_int_value(in_attr[i].int_value()); |
|
break; |
|
case elfcpp::Tag_ABI_FP_16bit_format: |
|
if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0) |
|
{ |
|
if (in_attr[i].int_value() != out_attr[i].int_value() |
|
&& parameters->options().warn_mismatch()) |
|
gold_error(_("fp16 format mismatch between %s and output"), |
|
name); |
|
} |
|
if (in_attr[i].int_value() != 0) |
|
out_attr[i].set_int_value(in_attr[i].int_value()); |
|
break; |
|
|
|
case elfcpp::Tag_DIV_use: |
|
{ |
|
// A value of zero on input means that the divide |
|
// instruction may be used if available in the base |
|
// architecture as specified via Tag_CPU_arch and |
|
// Tag_CPU_arch_profile. A value of 1 means that the user |
|
// did not want divide instructions. A value of 2 |
|
// explicitly means that divide instructions were allowed |
|
// in ARM and Thumb state. |
|
int arch = this-> |
|
get_aeabi_object_attribute(elfcpp::Tag_CPU_arch)-> |
|
int_value(); |
|
int profile = this-> |
|
get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile)-> |
|
int_value(); |
|
if (in_attr[i].int_value() == out_attr[i].int_value()) |
|
{ |
|
// Do nothing. |
|
} |
|
else if (attributes_forbid_div(&in_attr[i]) |
|
&& !attributes_accept_div(arch, profile, &out_attr[i])) |
|
out_attr[i].set_int_value(1); |
|
else if (attributes_forbid_div(&out_attr[i]) |
|
&& attributes_accept_div(arch, profile, &in_attr[i])) |
|
out_attr[i].set_int_value(in_attr[i].int_value()); |
|
else if (in_attr[i].int_value() == 2) |
|
out_attr[i].set_int_value(in_attr[i].int_value()); |
|
} |
|
break; |
|
|
|
case elfcpp::Tag_MPextension_use_legacy: |
|
// We don't output objects with Tag_MPextension_use_legacy - we |
|
// move the value to Tag_MPextension_use. |
|
if (in_attr[i].int_value() != 0 |
|
&& in_attr[elfcpp::Tag_MPextension_use].int_value() != 0) |
|
{ |
|
if (in_attr[elfcpp::Tag_MPextension_use].int_value() |
|
!= in_attr[i].int_value()) |
|
{ |
|
gold_error(_("%s has has both the current and legacy " |
|
"Tag_MPextension_use attributes"), |
|
name); |
|
} |
|
} |
|
|
|
if (in_attr[i].int_value() |
|
> out_attr[elfcpp::Tag_MPextension_use].int_value()) |
|
out_attr[elfcpp::Tag_MPextension_use] = in_attr[i]; |
|
|
|
break; |
|
|
|
case elfcpp::Tag_nodefaults: |
|
// This tag is set if it exists, but the value is unused (and is |
|
// typically zero). We don't actually need to do anything here - |
|
// the merge happens automatically when the type flags are merged |
|
// below. |
|
break; |
|
case elfcpp::Tag_also_compatible_with: |
|
// Already done in Tag_CPU_arch. |
|
break; |
|
case elfcpp::Tag_conformance: |
|
// Keep the attribute if it matches. Throw it away otherwise. |
|
// No attribute means no claim to conform. |
|
if (in_attr[i].string_value() != out_attr[i].string_value()) |
|
out_attr[i].set_string_value(""); |
|
break; |
|
|
|
default: |
|
{ |
|
const char* err_object = NULL; |
|
|
|
// The "known_obj_attributes" table does contain some undefined |
|
// attributes. Ensure that there are unused. |
|
if (out_attr[i].int_value() != 0 |
|
|| out_attr[i].string_value() != "") |
|
err_object = "output"; |
|
else if (in_attr[i].int_value() != 0 |
|
|| in_attr[i].string_value() != "") |
|
err_object = name; |
|
|
|
if (err_object != NULL |
|
&& parameters->options().warn_mismatch()) |
|
{ |
|
// Attribute numbers >=64 (mod 128) can be safely ignored. |
|
if ((i & 127) < 64) |
|
gold_error(_("%s: unknown mandatory EABI object attribute " |
|
"%d"), |
|
err_object, i); |
|
else |
|
gold_warning(_("%s: unknown EABI object attribute %d"), |
|
err_object, i); |
|
} |
|
|
|
// Only pass on attributes that match in both inputs. |
|
if (!in_attr[i].matches(out_attr[i])) |
|
{ |
|
out_attr[i].set_int_value(0); |
|
out_attr[i].set_string_value(""); |
|
} |
|
} |
|
} |
|
|
|
// If out_attr was copied from in_attr then it won't have a type yet. |
|
if (in_attr[i].type() && !out_attr[i].type()) |
|
out_attr[i].set_type(in_attr[i].type()); |
|
} |
|
|
|
// Merge Tag_compatibility attributes and any common GNU ones. |
|
this->attributes_section_data_->merge(name, pasd); |
|
|
|
// Check for any attributes not known on ARM. |
|
typedef Vendor_object_attributes::Other_attributes Other_attributes; |
|
const Other_attributes* in_other_attributes = pasd->other_attributes(vendor); |
|
Other_attributes::const_iterator in_iter = in_other_attributes->begin(); |
|
Other_attributes* out_other_attributes = |
|
this->attributes_section_data_->other_attributes(vendor); |
|
Other_attributes::iterator out_iter = out_other_attributes->begin(); |
|
|
|
while (in_iter != in_other_attributes->end() |
|
|| out_iter != out_other_attributes->end()) |
|
{ |
|
const char* err_object = NULL; |
|
int err_tag = 0; |
|
|
|
// The tags for each list are in numerical order. |
|
// If the tags are equal, then merge. |
|
if (out_iter != out_other_attributes->end() |
|
&& (in_iter == in_other_attributes->end() |
|
|| in_iter->first > out_iter->first)) |
|
{ |
|
// This attribute only exists in output. We can't merge, and we |
|
// don't know what the tag means, so delete it. |
|
err_object = "output"; |
|
err_tag = out_iter->first; |
|
int saved_tag = out_iter->first; |
|
delete out_iter->second; |
|
out_other_attributes->erase(out_iter); |
|
out_iter = out_other_attributes->upper_bound(saved_tag); |
|
} |
|
else if (in_iter != in_other_attributes->end() |
|
&& (out_iter != out_other_attributes->end() |
|
|| in_iter->first < out_iter->first)) |
|
{ |
|
// This attribute only exists in input. We can't merge, and we |
|
// don't know what the tag means, so ignore it. |
|
err_object = name; |
|
err_tag = in_iter->first; |
|
++in_iter; |
|
} |
|
else // The tags are equal. |
|
{ |
|
// As present, all attributes in the list are unknown, and |
|
// therefore can't be merged meaningfully. |
|
err_object = "output"; |
|
err_tag = out_iter->first; |
|
|
|
// Only pass on attributes that match in both inputs. |
|
if (!in_iter->second->matches(*(out_iter->second))) |
|
{ |
|
// No match. Delete the attribute. |
|
int saved_tag = out_iter->first; |
|
delete out_iter->second; |
|
out_other_attributes->erase(out_iter); |
|
out_iter = out_other_attributes->upper_bound(saved_tag); |
|
} |
|
else |
|
{ |
|
// Matched. Keep the attribute and move to the next. |
|
++out_iter; |
|
++in_iter; |
|
} |
|
} |
|
|
|
if (err_object && parameters->options().warn_mismatch()) |
|
{ |
|
// Attribute numbers >=64 (mod 128) can be safely ignored. */ |
|
if ((err_tag & 127) < 64) |
|
{ |
|
gold_error(_("%s: unknown mandatory EABI object attribute %d"), |
|
err_object, err_tag); |
|
} |
|
else |
|
{ |
|
gold_warning(_("%s: unknown EABI object attribute %d"), |
|
err_object, err_tag); |
|
} |
|
} |
|
} |
|
} |
|
|
|
// Stub-generation methods for Target_arm. |
|
|
|
// Make a new Arm_input_section object. |
|
|
|
template<bool big_endian> |
|
Arm_input_section<big_endian>* |
|
Target_arm<big_endian>::new_arm_input_section( |
|
Relobj* relobj, |
|
unsigned int shndx) |
|
{ |
|
Section_id sid(relobj, shndx); |
|
|
|
Arm_input_section<big_endian>* arm_input_section = |
|
new Arm_input_section<big_endian>(relobj, shndx); |
|
arm_input_section->init(); |
|
|
|
// Register new Arm_input_section in map for look-up. |
|
std::pair<typename Arm_input_section_map::iterator, bool> ins = |
|
this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section)); |
|
|
|
// Make sure that it we have not created another Arm_input_section |
|
// for this input section already. |
|
gold_assert(ins.second); |
|
|
|
return arm_input_section; |
|
} |
|
|
|
// Find the Arm_input_section object corresponding to the SHNDX-th input |
|
// section of RELOBJ. |
|
|
|
template<bool big_endian> |
|
Arm_input_section<big_endian>* |
|
Target_arm<big_endian>::find_arm_input_section( |
|
Relobj* relobj, |
|
unsigned int shndx) const |
|
{ |
|
Section_id sid(relobj, shndx); |
|
typename Arm_input_section_map::const_iterator p = |
|
this->arm_input_section_map_.find(sid); |
|
return (p != this->arm_input_section_map_.end()) ? p->second : NULL; |
|
} |
|
|
|
// Make a new stub table. |
|
|
|
template<bool big_endian> |
|
Stub_table<big_endian>* |
|
Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner) |
|
{ |
|
Stub_table<big_endian>* stub_table = |
|
new Stub_table<big_endian>(owner); |
|
this->stub_tables_.push_back(stub_table); |
|
|
|
stub_table->set_address(owner->address() + owner->data_size()); |
|
stub_table->set_file_offset(owner->offset() + owner->data_size()); |
|
stub_table->finalize_data_size(); |
|
|
|
return stub_table; |
|
} |
|
|
|
// Scan a relocation for stub generation. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::scan_reloc_for_stub( |
|
const Relocate_info<32, big_endian>* relinfo, |
|
unsigned int r_type, |
|
const Sized_symbol<32>* gsym, |
|
unsigned int r_sym, |
|
const Symbol_value<32>* psymval, |
|
elfcpp::Elf_types<32>::Elf_Swxword addend, |
|
Arm_address address) |
|
{ |
|
const Arm_relobj<big_endian>* arm_relobj = |
|
Arm_relobj<big_endian>::as_arm_relobj(relinfo->object); |
|
|
|
bool target_is_thumb; |
|
Symbol_value<32> symval; |
|
if (gsym != NULL) |
|
{ |
|
// This is a global symbol. Determine if we use PLT and if the |
|
// final target is THUMB. |
|
if (gsym->use_plt_offset(Scan::get_reference_flags(r_type))) |
|
{ |
|
// This uses a PLT, change the symbol value. |
|
symval.set_output_value(this->plt_address_for_global(gsym)); |
|
psymval = &symval; |
|
target_is_thumb = false; |
|
} |
|
else if (gsym->is_undefined()) |
|
// There is no need to generate a stub symbol is undefined. |
|
return; |
|
else |
|
{ |
|
target_is_thumb = |
|
((gsym->type() == elfcpp::STT_ARM_TFUNC) |
|
|| (gsym->type() == elfcpp::STT_FUNC |
|
&& !gsym->is_undefined() |
|
&& ((psymval->value(arm_relobj, 0) & 1) != 0))); |
|
} |
|
} |
|
else |
|
{ |
|
// This is a local symbol. Determine if the final target is THUMB. |
|
target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym); |
|
} |
|
|
|
// Strip LSB if this points to a THUMB target. |
|
const Arm_reloc_property* reloc_property = |
|
arm_reloc_property_table->get_implemented_static_reloc_property(r_type); |
|
gold_assert(reloc_property != NULL); |
|
if (target_is_thumb |
|
&& reloc_property->uses_thumb_bit() |
|
&& ((psymval->value(arm_relobj, 0) & 1) != 0)) |
|
{ |
|
Arm_address stripped_value = |
|
psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1); |
|
symval.set_output_value(stripped_value); |
|
psymval = &symval; |
|
} |
|
|
|
// Get the symbol value. |
|
Symbol_value<32>::Value value = psymval->value(arm_relobj, 0); |
|
|
|
// Owing to pipelining, the PC relative branches below actually skip |
|
// two instructions when the branch offset is 0. |
|
Arm_address destination; |
|
switch (r_type) |
|
{ |
|
case elfcpp::R_ARM_CALL: |
|
case elfcpp::R_ARM_JUMP24: |
|
case elfcpp::R_ARM_PLT32: |
|
// ARM branches. |
|
destination = value + addend + 8; |
|
break; |
|
case elfcpp::R_ARM_THM_CALL: |
|
case elfcpp::R_ARM_THM_XPC22: |
|
case elfcpp::R_ARM_THM_JUMP24: |
|
case elfcpp::R_ARM_THM_JUMP19: |
|
// THUMB branches. |
|
destination = value + addend + 4; |
|
break; |
|
default: |
|
gold_unreachable(); |
|
} |
|
|
|
Reloc_stub* stub = NULL; |
|
Stub_type stub_type = |
|
Reloc_stub::stub_type_for_reloc(r_type, address, destination, |
|
target_is_thumb); |
|
if (stub_type != arm_stub_none) |
|
{ |
|
// Try looking up an existing stub from a stub table. |
|
Stub_table<big_endian>* stub_table = |
|
arm_relobj->stub_table(relinfo->data_shndx); |
|
gold_assert(stub_table != NULL); |
|
|
|
// Locate stub by destination. |
|
Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend); |
|
|
|
// Create a stub if there is not one already |
|
stub = stub_table->find_reloc_stub(stub_key); |
|
if (stub == NULL) |
|
{ |
|
// create a new stub and add it to stub table. |
|
stub = this->stub_factory().make_reloc_stub(stub_type); |
|
stub_table->add_reloc_stub(stub, stub_key); |
|
} |
|
|
|
// Record the destination address. |
|
stub->set_destination_address(destination |
|
| (target_is_thumb ? 1 : 0)); |
|
} |
|
|
|
// For Cortex-A8, we need to record a relocation at 4K page boundary. |
|
if (this->fix_cortex_a8_ |
|
&& (r_type == elfcpp::R_ARM_THM_JUMP24 |
|
|| r_type == elfcpp::R_ARM_THM_JUMP19 |
|
|| r_type == elfcpp::R_ARM_THM_CALL |
|
|| r_type == elfcpp::R_ARM_THM_XPC22) |
|
&& (address & 0xfffU) == 0xffeU) |
|
{ |
|
// Found a candidate. Note we haven't checked the destination is |
|
// within 4K here: if we do so (and don't create a record) we can't |
|
// tell that a branch should have been relocated when scanning later. |
|
this->cortex_a8_relocs_info_[address] = |
|
new Cortex_a8_reloc(stub, r_type, |
|
destination | (target_is_thumb ? 1 : 0)); |
|
} |
|
} |
|
|
|
// This function scans a relocation sections for stub generation. |
|
// The template parameter Relocate must be a class type which provides |
|
// a single function, relocate(), which implements the machine |
|
// specific part of a relocation. |
|
|
|
// BIG_ENDIAN is the endianness of the data. SH_TYPE is the section type: |
|
// SHT_REL or SHT_RELA. |
|
|
|
// PRELOCS points to the relocation data. RELOC_COUNT is the number |
|
// of relocs. OUTPUT_SECTION is the output section. |
|
// NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be |
|
// mapped to output offsets. |
|
|
|
// VIEW is the section data, VIEW_ADDRESS is its memory address, and |
|
// VIEW_SIZE is the size. These refer to the input section, unless |
|
// NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to |
|
// the output section. |
|
|
|
template<bool big_endian> |
|
template<int sh_type> |
|
void inline |
|
Target_arm<big_endian>::scan_reloc_section_for_stubs( |
|
const Relocate_info<32, big_endian>* relinfo, |
|
const unsigned char* prelocs, |
|
size_t reloc_count, |
|
Output_section* output_section, |
|
bool needs_special_offset_handling, |
|
const unsigned char* view, |
|
elfcpp::Elf_types<32>::Elf_Addr view_address, |
|
section_size_type) |
|
{ |
|
typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype; |
|
const int reloc_size = |
|
Reloc_types<sh_type, 32, big_endian>::reloc_size; |
|
|
|
Arm_relobj<big_endian>* arm_object = |
|
Arm_relobj<big_endian>::as_arm_relobj(relinfo->object); |
|
unsigned int local_count = arm_object->local_symbol_count(); |
|
|
|
gold::Default_comdat_behavior default_comdat_behavior; |
|
Comdat_behavior comdat_behavior = CB_UNDETERMINED; |
|
|
|
for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size) |
|
{ |
|
Reltype reloc(prelocs); |
|
|
|
typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info(); |
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info); |
|
unsigned int r_type = elfcpp::elf_r_type<32>(r_info); |
|
|
|
r_type = this->get_real_reloc_type(r_type); |
|
|
|
// Only a few relocation types need stubs. |
|
if ((r_type != elfcpp::R_ARM_CALL) |
|
&& (r_type != elfcpp::R_ARM_JUMP24) |
|
&& (r_type != elfcpp::R_ARM_PLT32) |
|
&& (r_type != elfcpp::R_ARM_THM_CALL) |
|
&& (r_type != elfcpp::R_ARM_THM_XPC22) |
|
&& (r_type != elfcpp::R_ARM_THM_JUMP24) |
|
&& (r_type != elfcpp::R_ARM_THM_JUMP19) |
|
&& (r_type != elfcpp::R_ARM_V4BX)) |
|
continue; |
|
|
|
section_offset_type offset = |
|
convert_to_section_size_type(reloc.get_r_offset()); |
|
|
|
if (needs_special_offset_handling) |
|
{ |
|
offset = output_section->output_offset(relinfo->object, |
|
relinfo->data_shndx, |
|
offset); |
|
if (offset == -1) |
|
continue; |
|
} |
|
|
|
// Create a v4bx stub if --fix-v4bx-interworking is used. |
|
if (r_type == elfcpp::R_ARM_V4BX) |
|
{ |
|
if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING) |
|
{ |
|
// Get the BX instruction. |
|
typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
|
const Valtype* wv = |
|
reinterpret_cast<const Valtype*>(view + offset); |
|
elfcpp::Elf_types<32>::Elf_Swxword insn = |
|
elfcpp::Swap<32, big_endian>::readval(wv); |
|
const uint32_t reg = (insn & 0xf); |
|
|
|
if (reg < 0xf) |
|
{ |
|
// Try looking up an existing stub from a stub table. |
|
Stub_table<big_endian>* stub_table = |
|
arm_object->stub_table(relinfo->data_shndx); |
|
gold_assert(stub_table != NULL); |
|
|
|
if (stub_table->find_arm_v4bx_stub(reg) == NULL) |
|
{ |
|
// create a new stub and add it to stub table. |
|
Arm_v4bx_stub* stub = |
|
this->stub_factory().make_arm_v4bx_stub(reg); |
|
gold_assert(stub != NULL); |
|
stub_table->add_arm_v4bx_stub(stub); |
|
} |
|
} |
|
} |
|
continue; |
|
} |
|
|
|
// Get the addend. |
|
Stub_addend_reader<sh_type, big_endian> stub_addend_reader; |
|
elfcpp::Elf_types<32>::Elf_Swxword addend = |
|
stub_addend_reader(r_type, view + offset, reloc); |
|
|
|
const Sized_symbol<32>* sym; |
|
|
|
Symbol_value<32> symval; |
|
const Symbol_value<32> *psymval; |
|
bool is_defined_in_discarded_section; |
|
unsigned int shndx; |
|
if (r_sym < local_count) |
|
{ |
|
sym = NULL; |
|
psymval = arm_object->local_symbol(r_sym); |
|
|
|
// If the local symbol belongs to a section we are discarding, |
|
// and that section is a debug section, try to find the |
|
// corresponding kept section and map this symbol to its |
|
// counterpart in the kept section. The symbol must not |
|
// correspond to a section we are folding. |
|
bool is_ordinary; |
|
shndx = psymval->input_shndx(&is_ordinary); |
|
is_defined_in_discarded_section = |
|
(is_ordinary |
|
&& shndx != elfcpp::SHN_UNDEF |
|
&& !arm_object->is_section_included(shndx) |
|
&& !relinfo->symtab->is_section_folded(arm_object, shndx)); |
|
|
|
// We need to compute the would-be final value of this local |
|
// symbol. |
|
if (!is_defined_in_discarded_section) |
|
{ |
|
typedef Sized_relobj_file<32, big_endian> ObjType; |
|
typename ObjType::Compute_final_local_value_status status = |
|
arm_object->compute_final_local_value(r_sym, psymval, &symval, |
|
relinfo->symtab); |
|
if (status == ObjType::CFLV_OK) |
|
{ |
|
// Currently we cannot handle a branch to a target in |
|
// a merged section. If this is the case, issue an error |
|
// and also free the merge symbol value. |
|
if (!symval.has_output_value()) |
|
{ |
|
const std::string& section_name = |
|
arm_object->section_name(shndx); |
|
arm_object->error(_("cannot handle branch to local %u " |
|
"in a merged section %s"), |
|
r_sym, section_name.c_str()); |
|
} |
|
psymval = &symval; |
|
} |
|
else |
|
{ |
|
// We cannot determine the final value. |
|
continue; |
|
} |
|
} |
|
} |
|
else |
|
{ |
|
const Symbol* gsym; |
|
gsym = arm_object->global_symbol(r_sym); |
|
gold_assert(gsym != NULL); |
|
if (gsym->is_forwarder()) |
|
gsym = relinfo->symtab->resolve_forwards(gsym); |
|
|
|
sym = static_cast<const Sized_symbol<32>*>(gsym); |
|
if (sym->has_symtab_index() && sym->symtab_index() != -1U) |
|
symval.set_output_symtab_index(sym->symtab_index()); |
|
else |
|
symval.set_no_output_symtab_entry(); |
|
|
|
// We need to compute the would-be final value of this global |
|
// symbol. |
|
const Symbol_table* symtab = relinfo->symtab; |
|
const Sized_symbol<32>* sized_symbol = |
|
symtab->get_sized_symbol<32>(gsym); |
|
Symbol_table::Compute_final_value_status status; |
|
Arm_address value = |
|
symtab->compute_final_value<32>(sized_symbol, &status); |
|
|
|
// Skip this if the symbol has not output section. |
|
if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION) |
|
continue; |
|
symval.set_output_value(value); |
|
|
|
if (gsym->type() == elfcpp::STT_TLS) |
|
symval.set_is_tls_symbol(); |
|
else if (gsym->type() == elfcpp::STT_GNU_IFUNC) |
|
symval.set_is_ifunc_symbol(); |
|
psymval = &symval; |
|
|
|
is_defined_in_discarded_section = |
|
(gsym->is_defined_in_discarded_section() |
|
&& gsym->is_undefined()); |
|
shndx = 0; |
|
} |
|
|
|
Symbol_value<32> symval2; |
|
if (is_defined_in_discarded_section) |
|
{ |
|
if (comdat_behavior == CB_UNDETERMINED) |
|
{ |
|
std::string name = arm_object->section_name(relinfo->data_shndx); |
|
comdat_behavior = default_comdat_behavior.get(name.c_str()); |
|
} |
|
if (comdat_behavior == CB_PRETEND) |
|
{ |
|
// FIXME: This case does not work for global symbols. |
|
// We have no place to store the original section index. |
|
// Fortunately this does not matter for comdat sections, |
|
// only for sections explicitly discarded by a linker |
|
// script. |
|
bool found; |
|
typename elfcpp::Elf_types<32>::Elf_Addr value = |
|
arm_object->map_to_kept_section(shndx, &found); |
|
if (found) |
|
symval2.set_output_value(value + psymval->input_value()); |
|
else |
|
symval2.set_output_value(0); |
|
} |
|
else |
|
{ |
|
if (comdat_behavior == CB_WARNING) |
|
gold_warning_at_location(relinfo, i, offset, |
|
_("relocation refers to discarded " |
|
"section")); |
|
symval2.set_output_value(0); |
|
} |
|
symval2.set_no_output_symtab_entry(); |
|
psymval = &symval2; |
|
} |
|
|
|
// If symbol is a section symbol, we don't know the actual type of |
|
// destination. Give up. |
|
if (psymval->is_section_symbol()) |
|
continue; |
|
|
|
this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval, |
|
addend, view_address + offset); |
|
} |
|
} |
|
|
|
// Scan an input section for stub generation. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::scan_section_for_stubs( |
|
const Relocate_info<32, big_endian>* relinfo, |
|
unsigned int sh_type, |
|
const unsigned char* prelocs, |
|
size_t reloc_count, |
|
Output_section* output_section, |
|
bool needs_special_offset_handling, |
|
const unsigned char* view, |
|
Arm_address view_address, |
|
section_size_type view_size) |
|
{ |
|
if (sh_type == elfcpp::SHT_REL) |
|
this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>( |
|
relinfo, |
|
prelocs, |
|
reloc_count, |
|
output_section, |
|
needs_special_offset_handling, |
|
view, |
|
view_address, |
|
view_size); |
|
else if (sh_type == elfcpp::SHT_RELA) |
|
// We do not support RELA type relocations yet. This is provided for |
|
// completeness. |
|
this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>( |
|
relinfo, |
|
prelocs, |
|
reloc_count, |
|
output_section, |
|
needs_special_offset_handling, |
|
view, |
|
view_address, |
|
view_size); |
|
else |
|
gold_unreachable(); |
|
} |
|
|
|
// Group input sections for stub generation. |
|
// |
|
// We group input sections in an output section so that the total size, |
|
// including any padding space due to alignment is smaller than GROUP_SIZE |
|
// unless the only input section in group is bigger than GROUP_SIZE already. |
|
// Then an ARM stub table is created to follow the last input section |
|
// in group. For each group an ARM stub table is created an is placed |
|
// after the last group. If STUB_ALWAYS_AFTER_BRANCH is false, we further |
|
// extend the group after the stub table. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::group_sections( |
|
Layout* layout, |
|
section_size_type group_size, |
|
bool stubs_always_after_branch, |
|
const Task* task) |
|
{ |
|
// Group input sections and insert stub table |
|
Layout::Section_list section_list; |
|
layout->get_executable_sections(§ion_list); |
|
for (Layout::Section_list::const_iterator p = section_list.begin(); |
|
p != section_list.end(); |
|
++p) |
|
{ |
|
Arm_output_section<big_endian>* output_section = |
|
Arm_output_section<big_endian>::as_arm_output_section(*p); |
|
output_section->group_sections(group_size, stubs_always_after_branch, |
|
this, task); |
|
} |
|
} |
|
|
|
// Relaxation hook. This is where we do stub generation. |
|
|
|
template<bool big_endian> |
|
bool |
|
Target_arm<big_endian>::do_relax( |
|
int pass, |
|
const Input_objects* input_objects, |
|
Symbol_table* symtab, |
|
Layout* layout, |
|
const Task* task) |
|
{ |
|
// No need to generate stubs if this is a relocatable link. |
|
gold_assert(!parameters->options().relocatable()); |
|
|
|
// If this is the first pass, we need to group input sections into |
|
// stub groups. |
|
bool done_exidx_fixup = false; |
|
typedef typename Stub_table_list::iterator Stub_table_iterator; |
|
if (pass == 1) |
|
{ |
|
// Determine the stub group size. The group size is the absolute |
|
// value of the parameter --stub-group-size. If --stub-group-size |
|
// is passed a negative value, we restrict stubs to be always after |
|
// the stubbed branches. |
|
int32_t stub_group_size_param = |
|
parameters->options().stub_group_size(); |
|
bool stubs_always_after_branch = stub_group_size_param < 0; |
|
section_size_type stub_group_size = abs(stub_group_size_param); |
|
|
|
if (stub_group_size == 1) |
|
{ |
|
// Default value. |
|
// Thumb branch range is +-4MB has to be used as the default |
|
// maximum size (a given section can contain both ARM and Thumb |
|
// code, so the worst case has to be taken into account). If we are |
|
// fixing cortex-a8 errata, the branch range has to be even smaller, |
|
// since wide conditional branch has a range of +-1MB only. |
|
// |
|
// This value is 48K less than that, which allows for 4096 |
|
// 12-byte stubs. If we exceed that, then we will fail to link. |
|
// The user will have to relink with an explicit group size |
|
// option. |
|
stub_group_size = 4145152; |
|
} |
|
|
|
// The Cortex-A8 erratum fix depends on stubs not being in the same 4K |
|
// page as the first half of a 32-bit branch straddling two 4K pages. |
|
// This is a crude way of enforcing that. In addition, long conditional |
|
// branches of THUMB-2 have a range of +-1M. If we are fixing cortex-A8 |
|
// erratum, limit the group size to (1M - 12k) to avoid unreachable |
|
// cortex-A8 stubs from long conditional branches. |
|
if (this->fix_cortex_a8_) |
|
{ |
|
stubs_always_after_branch = true; |
|
const section_size_type cortex_a8_group_size = 1024 * (1024 - 12); |
|
stub_group_size = std::max(stub_group_size, cortex_a8_group_size); |
|
} |
|
|
|
group_sections(layout, stub_group_size, stubs_always_after_branch, task); |
|
|
|
// Also fix .ARM.exidx section coverage. |
|
Arm_output_section<big_endian>* exidx_output_section = NULL; |
|
for (Layout::Section_list::const_iterator p = |
|
layout->section_list().begin(); |
|
p != layout->section_list().end(); |
|
++p) |
|
if ((*p)->type() == elfcpp::SHT_ARM_EXIDX) |
|
{ |
|
if (exidx_output_section == NULL) |
|
exidx_output_section = |
|
Arm_output_section<big_endian>::as_arm_output_section(*p); |
|
else |
|
// We cannot handle this now. |
|
gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a " |
|
"non-relocatable link"), |
|
exidx_output_section->name(), |
|
(*p)->name()); |
|
} |
|
|
|
if (exidx_output_section != NULL) |
|
{ |
|
this->fix_exidx_coverage(layout, input_objects, exidx_output_section, |
|
symtab, task); |
|
done_exidx_fixup = true; |
|
} |
|
} |
|
else |
|
{ |
|
// If this is not the first pass, addresses and file offsets have |
|
// been reset at this point, set them here. |
|
for (Stub_table_iterator sp = this->stub_tables_.begin(); |
|
sp != this->stub_tables_.end(); |
|
++sp) |
|
{ |
|
Arm_input_section<big_endian>* owner = (*sp)->owner(); |
|
off_t off = align_address(owner->original_size(), |
|
(*sp)->addralign()); |
|
(*sp)->set_address_and_file_offset(owner->address() + off, |
|
owner->offset() + off); |
|
} |
|
} |
|
|
|
// The Cortex-A8 stubs are sensitive to layout of code sections. At the |
|
// beginning of each relaxation pass, just blow away all the stubs. |
|
// Alternatively, we could selectively remove only the stubs and reloc |
|
// information for code sections that have moved since the last pass. |
|
// That would require more book-keeping. |
|
if (this->fix_cortex_a8_) |
|
{ |
|
// Clear all Cortex-A8 reloc information. |
|
for (typename Cortex_a8_relocs_info::const_iterator p = |
|
this->cortex_a8_relocs_info_.begin(); |
|
p != this->cortex_a8_relocs_info_.end(); |
|
++p) |
|
delete p->second; |
|
this->cortex_a8_relocs_info_.clear(); |
|
|
|
// Remove all Cortex-A8 stubs. |
|
for (Stub_table_iterator sp = this->stub_tables_.begin(); |
|
sp != this->stub_tables_.end(); |
|
++sp) |
|
(*sp)->remove_all_cortex_a8_stubs(); |
|
} |
|
|
|
// Scan relocs for relocation stubs |
|
for (Input_objects::Relobj_iterator op = input_objects->relobj_begin(); |
|
op != input_objects->relobj_end(); |
|
++op) |
|
{ |
|
Arm_relobj<big_endian>* arm_relobj = |
|
Arm_relobj<big_endian>::as_arm_relobj(*op); |
|
// Lock the object so we can read from it. This is only called |
|
// single-threaded from Layout::finalize, so it is OK to lock. |
|
Task_lock_obj<Object> tl(task, arm_relobj); |
|
arm_relobj->scan_sections_for_stubs(this, symtab, layout); |
|
} |
|
|
|
// Check all stub tables to see if any of them have their data sizes |
|
// or addresses alignments changed. These are the only things that |
|
// matter. |
|
bool any_stub_table_changed = false; |
|
Unordered_set<const Output_section*> sections_needing_adjustment; |
|
for (Stub_table_iterator sp = this->stub_tables_.begin(); |
|
(sp != this->stub_tables_.end() |
|
&& (parameters->options().stub_group_auto_padding() |
|
|| !any_stub_table_changed)); |
|
++sp) |
|
{ |
|
if ((*sp)->update_data_size_and_addralign()) |
|
{ |
|
// Update data size of stub table owner. |
|
Arm_input_section<big_endian>* owner = (*sp)->owner(); |
|
uint64_t address = owner->address(); |
|
off_t offset = owner->offset(); |
|
owner->reset_address_and_file_offset(); |
|
owner->set_address_and_file_offset(address, offset); |
|
|
|
sections_needing_adjustment.insert(owner->output_section()); |
|
any_stub_table_changed = true; |
|
} |
|
} |
|
|
|
// Output_section_data::output_section() returns a const pointer but we |
|
// need to update output sections, so we record all output sections needing |
|
// update above and scan the sections here to find out what sections need |
|
// to be updated. |
|
for (Layout::Section_list::const_iterator p = layout->section_list().begin(); |
|
p != layout->section_list().end(); |
|
++p) |
|
{ |
|
if (sections_needing_adjustment.find(*p) |
|
!= sections_needing_adjustment.end()) |
|
(*p)->set_section_offsets_need_adjustment(); |
|
} |
|
|
|
// Stop relaxation if no EXIDX fix-up and no stub table change. |
|
bool continue_relaxation = done_exidx_fixup || any_stub_table_changed; |
|
|
|
// Finalize the stubs in the last relaxation pass. |
|
if (!continue_relaxation) |
|
{ |
|
for (Stub_table_iterator sp = this->stub_tables_.begin(); |
|
(sp != this->stub_tables_.end()) && !any_stub_table_changed; |
|
++sp) |
|
(*sp)->finalize_stubs(); |
|
|
|
// Update output local symbol counts of objects if necessary. |
|
for (Input_objects::Relobj_iterator op = input_objects->relobj_begin(); |
|
op != input_objects->relobj_end(); |
|
++op) |
|
{ |
|
Arm_relobj<big_endian>* arm_relobj = |
|
Arm_relobj<big_endian>::as_arm_relobj(*op); |
|
|
|
// Update output local symbol counts. We need to discard local |
|
// symbols defined in parts of input sections that are discarded by |
|
// relaxation. |
|
if (arm_relobj->output_local_symbol_count_needs_update()) |
|
{ |
|
// We need to lock the object's file to update it. |
|
Task_lock_obj<Object> tl(task, arm_relobj); |
|
arm_relobj->update_output_local_symbol_count(); |
|
} |
|
} |
|
} |
|
|
|
return continue_relaxation; |
|
} |
|
|
|
// Relocate a stub. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::relocate_stub( |
|
Stub* stub, |
|
const Relocate_info<32, big_endian>* relinfo, |
|
Output_section* output_section, |
|
unsigned char* view, |
|
Arm_address address, |
|
section_size_type view_size) |
|
{ |
|
Relocate relocate; |
|
const Stub_template* stub_template = stub->stub_template(); |
|
for (size_t i = 0; i < stub_template->reloc_count(); i++) |
|
{ |
|
size_t reloc_insn_index = stub_template->reloc_insn_index(i); |
|
const Insn_template* insn = &stub_template->insns()[reloc_insn_index]; |
|
|
|
unsigned int r_type = insn->r_type(); |
|
section_size_type reloc_offset = stub_template->reloc_offset(i); |
|
section_size_type reloc_size = insn->size(); |
|
gold_assert(reloc_offset + reloc_size <= view_size); |
|
|
|
// This is the address of the stub destination. |
|
Arm_address target = stub->reloc_target(i) + insn->reloc_addend(); |
|
Symbol_value<32> symval; |
|
symval.set_output_value(target); |
|
|
|
// Synthesize a fake reloc just in case. We don't have a symbol so |
|
// we use 0. |
|
unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size]; |
|
memset(reloc_buffer, 0, sizeof(reloc_buffer)); |
|
elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer); |
|
reloc_write.put_r_offset(reloc_offset); |
|
reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type)); |
|
elfcpp::Rel<32, big_endian> rel(reloc_buffer); |
|
|
|
relocate.relocate(relinfo, this, output_section, |
|
this->fake_relnum_for_stubs, rel, r_type, |
|
NULL, &symval, view + reloc_offset, |
|
address + reloc_offset, reloc_size); |
|
} |
|
} |
|
|
|
// Determine whether an object attribute tag takes an integer, a |
|
// string or both. |
|
|
|
template<bool big_endian> |
|
int |
|
Target_arm<big_endian>::do_attribute_arg_type(int tag) const |
|
{ |
|
if (tag == Object_attribute::Tag_compatibility) |
|
return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL |
|
| Object_attribute::ATTR_TYPE_FLAG_STR_VAL); |
|
else if (tag == elfcpp::Tag_nodefaults) |
|
return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL |
|
| Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT); |
|
else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name) |
|
return Object_attribute::ATTR_TYPE_FLAG_STR_VAL; |
|
else if (tag < 32) |
|
return Object_attribute::ATTR_TYPE_FLAG_INT_VAL; |
|
else |
|
return ((tag & 1) != 0 |
|
? Object_attribute::ATTR_TYPE_FLAG_STR_VAL |
|
: Object_attribute::ATTR_TYPE_FLAG_INT_VAL); |
|
} |
|
|
|
// Reorder attributes. |
|
// |
|
// The ABI defines that Tag_conformance should be emitted first, and that |
|
// Tag_nodefaults should be second (if either is defined). This sets those |
|
// two positions, and bumps up the position of all the remaining tags to |
|
// compensate. |
|
|
|
template<bool big_endian> |
|
int |
|
Target_arm<big_endian>::do_attributes_order(int num) const |
|
{ |
|
// Reorder the known object attributes in output. We want to move |
|
// Tag_conformance to position 4 and Tag_conformance to position 5 |
|
// and shift everything between 4 .. Tag_conformance - 1 to make room. |
|
if (num == 4) |
|
return elfcpp::Tag_conformance; |
|
if (num == 5) |
|
return elfcpp::Tag_nodefaults; |
|
if ((num - 2) < elfcpp::Tag_nodefaults) |
|
return num - 2; |
|
if ((num - 1) < elfcpp::Tag_conformance) |
|
return num - 1; |
|
return num; |
|
} |
|
|
|
// Scan a span of THUMB code for Cortex-A8 erratum. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::scan_span_for_cortex_a8_erratum( |
|
Arm_relobj<big_endian>* arm_relobj, |
|
unsigned int shndx, |
|
section_size_type span_start, |
|
section_size_type span_end, |
|
const unsigned char* view, |
|
Arm_address address) |
|
{ |
|
// Scan for 32-bit Thumb-2 branches which span two 4K regions, where: |
|
// |
|
// The opcode is BLX.W, BL.W, B.W, Bcc.W |
|
// The branch target is in the same 4KB region as the |
|
// first half of the branch. |
|
// The instruction before the branch is a 32-bit |
|
// length non-branch instruction. |
|
section_size_type i = span_start; |
|
bool last_was_32bit = false; |
|
bool last_was_branch = false; |
|
while (i < span_end) |
|
{ |
|
typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
|
const Valtype* wv = reinterpret_cast<const Valtype*>(view + i); |
|
uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv); |
|
bool is_blx = false, is_b = false; |
|
bool is_bl = false, is_bcc = false; |
|
|
|
bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000; |
|
if (insn_32bit) |
|
{ |
|
// Load the rest of the insn (in manual-friendly order). |
|
insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1); |
|
|
|
// Encoding T4: B<c>.W. |
|
is_b = (insn & 0xf800d000U) == 0xf0009000U; |
|
// Encoding T1: BL<c>.W. |
|
is_bl = (insn & 0xf800d000U) == 0xf000d000U; |
|
// Encoding T2: BLX<c>.W. |
|
is_blx = (insn & 0xf800d000U) == 0xf000c000U; |
|
// Encoding T3: B<c>.W (not permitted in IT block). |
|
is_bcc = ((insn & 0xf800d000U) == 0xf0008000U |
|
&& (insn & 0x07f00000U) != 0x03800000U); |
|
} |
|
|
|
bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc; |
|
|
|
// If this instruction is a 32-bit THUMB branch that crosses a 4K |
|
// page boundary and it follows 32-bit non-branch instruction, |
|
// we need to work around. |
|
if (is_32bit_branch |
|
&& ((address + i) & 0xfffU) == 0xffeU |
|
&& last_was_32bit |
|
&& !last_was_branch) |
|
{ |
|
// Check to see if there is a relocation stub for this branch. |
|
bool force_target_arm = false; |
|
bool force_target_thumb = false; |
|
const Cortex_a8_reloc* cortex_a8_reloc = NULL; |
|
Cortex_a8_relocs_info::const_iterator p = |
|
this->cortex_a8_relocs_info_.find(address + i); |
|
|
|
if (p != this->cortex_a8_relocs_info_.end()) |
|
{ |
|
cortex_a8_reloc = p->second; |
|
bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0; |
|
|
|
if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL |
|
&& !target_is_thumb) |
|
force_target_arm = true; |
|
else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL |
|
&& target_is_thumb) |
|
force_target_thumb = true; |
|
} |
|
|
|
off_t offset; |
|
Stub_type stub_type = arm_stub_none; |
|
|
|
// Check if we have an offending branch instruction. |
|
uint16_t upper_insn = (insn >> 16) & 0xffffU; |
|
uint16_t lower_insn = insn & 0xffffU; |
|
typedef class Arm_relocate_functions<big_endian> RelocFuncs; |
|
|
|
if (cortex_a8_reloc != NULL |
|
&& cortex_a8_reloc->reloc_stub() != NULL) |
|
// We've already made a stub for this instruction, e.g. |
|
// it's a long branch or a Thumb->ARM stub. Assume that |
|
// stub will suffice to work around the A8 erratum (see |
|
// setting of always_after_branch above). |
|
; |
|
else if (is_bcc) |
|
{ |
|
offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn, |
|
lower_insn); |
|
stub_type = arm_stub_a8_veneer_b_cond; |
|
} |
|
else if (is_b || is_bl || is_blx) |
|
{ |
|
offset = RelocFuncs::thumb32_branch_offset(upper_insn, |
|
lower_insn); |
|
if (is_blx) |
|
offset &= ~3; |
|
|
|
stub_type = (is_blx |
|
? arm_stub_a8_veneer_blx |
|
: (is_bl |
|
? arm_stub_a8_veneer_bl |
|
: arm_stub_a8_veneer_b)); |
|
} |
|
|
|
if (stub_type != arm_stub_none) |
|
{ |
|
Arm_address pc_for_insn = address + i + 4; |
|
|
|
// The original instruction is a BL, but the target is |
|
// an ARM instruction. If we were not making a stub, |
|
// the BL would have been converted to a BLX. Use the |
|
// BLX stub instead in that case. |
|
if (this->may_use_v5t_interworking() && force_target_arm |
|
&& stub_type == arm_stub_a8_veneer_bl) |
|
{ |
|
stub_type = arm_stub_a8_veneer_blx; |
|
is_blx = true; |
|
is_bl = false; |
|
} |
|
// Conversely, if the original instruction was |
|
// BLX but the target is Thumb mode, use the BL stub. |
|
else if (force_target_thumb |
|
&& stub_type == arm_stub_a8_veneer_blx) |
|
{ |
|
stub_type = arm_stub_a8_veneer_bl; |
|
is_blx = false; |
|
is_bl = true; |
|
} |
|
|
|
if (is_blx) |
|
pc_for_insn &= ~3; |
|
|
|
// If we found a relocation, use the proper destination, |
|
// not the offset in the (unrelocated) instruction. |
|
// Note this is always done if we switched the stub type above. |
|
if (cortex_a8_reloc != NULL) |
|
offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn); |
|
|
|
Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1); |
|
|
|
// Add a new stub if destination address in in the same page. |
|
if (((address + i) & ~0xfffU) == (target & ~0xfffU)) |
|
{ |
|
Cortex_a8_stub* stub = |
|
this->stub_factory_.make_cortex_a8_stub(stub_type, |
|
arm_relobj, shndx, |
|
address + i, |
|
target, insn); |
|
Stub_table<big_endian>* stub_table = |
|
arm_relobj->stub_table(shndx); |
|
gold_assert(stub_table != NULL); |
|
stub_table->add_cortex_a8_stub(address + i, stub); |
|
} |
|
} |
|
} |
|
|
|
i += insn_32bit ? 4 : 2; |
|
last_was_32bit = insn_32bit; |
|
last_was_branch = is_32bit_branch; |
|
} |
|
} |
|
|
|
// Apply the Cortex-A8 workaround. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::apply_cortex_a8_workaround( |
|
const Cortex_a8_stub* stub, |
|
Arm_address stub_address, |
|
unsigned char* insn_view, |
|
Arm_address insn_address) |
|
{ |
|
typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
|
Valtype* wv = reinterpret_cast<Valtype*>(insn_view); |
|
Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv); |
|
Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1); |
|
off_t branch_offset = stub_address - (insn_address + 4); |
|
|
|
typedef class Arm_relocate_functions<big_endian> RelocFuncs; |
|
switch (stub->stub_template()->type()) |
|
{ |
|
case arm_stub_a8_veneer_b_cond: |
|
// For a conditional branch, we re-write it to be an unconditional |
|
// branch to the stub. We use the THUMB-2 encoding here. |
|
upper_insn = 0xf000U; |
|
lower_insn = 0xb800U; |
|
// Fall through |
|
case arm_stub_a8_veneer_b: |
|
case arm_stub_a8_veneer_bl: |
|
case arm_stub_a8_veneer_blx: |
|
if ((lower_insn & 0x5000U) == 0x4000U) |
|
// For a BLX instruction, make sure that the relocation is |
|
// rounded up to a word boundary. This follows the semantics of |
|
// the instruction which specifies that bit 1 of the target |
|
// address will come from bit 1 of the base address. |
|
branch_offset = (branch_offset + 2) & ~3; |
|
|
|
// Put BRANCH_OFFSET back into the insn. |
|
gold_assert(!Bits<25>::has_overflow32(branch_offset)); |
|
upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset); |
|
lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset); |
|
break; |
|
|
|
default: |
|
gold_unreachable(); |
|
} |
|
|
|
// Put the relocated value back in the object file: |
|
elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn); |
|
elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn); |
|
} |
|
|
|
// Target selector for ARM. Note this is never instantiated directly. |
|
// It's only used in Target_selector_arm_nacl, below. |
|
|
|
template<bool big_endian> |
|
class Target_selector_arm : public Target_selector |
|
{ |
|
public: |
|
Target_selector_arm() |
|
: Target_selector(elfcpp::EM_ARM, 32, big_endian, |
|
(big_endian ? "elf32-bigarm" : "elf32-littlearm"), |
|
(big_endian ? "armelfb" : "armelf")) |
|
{ } |
|
|
|
Target* |
|
do_instantiate_target() |
|
{ return new Target_arm<big_endian>(); } |
|
}; |
|
|
|
// Fix .ARM.exidx section coverage. |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::fix_exidx_coverage( |
|
Layout* layout, |
|
const Input_objects* input_objects, |
|
Arm_output_section<big_endian>* exidx_section, |
|
Symbol_table* symtab, |
|
const Task* task) |
|
{ |
|
// We need to look at all the input sections in output in ascending |
|
// order of of output address. We do that by building a sorted list |
|
// of output sections by addresses. Then we looks at the output sections |
|
// in order. The input sections in an output section are already sorted |
|
// by addresses within the output section. |
|
|
|
typedef std::set<Output_section*, output_section_address_less_than> |
|
Sorted_output_section_list; |
|
Sorted_output_section_list sorted_output_sections; |
|
|
|
// Find out all the output sections of input sections pointed by |
|
// EXIDX input sections. |
|
for (Input_objects::Relobj_iterator p = input_objects->relobj_begin(); |
|
p != input_objects->relobj_end(); |
|
++p) |
|
{ |
|
Arm_relobj<big_endian>* arm_relobj = |
|
Arm_relobj<big_endian>::as_arm_relobj(*p); |
|
std::vector<unsigned int> shndx_list; |
|
arm_relobj->get_exidx_shndx_list(&shndx_list); |
|
for (size_t i = 0; i < shndx_list.size(); ++i) |
|
{ |
|
const Arm_exidx_input_section* exidx_input_section = |
|
arm_relobj->exidx_input_section_by_shndx(shndx_list[i]); |
|
gold_assert(exidx_input_section != NULL); |
|
if (!exidx_input_section->has_errors()) |
|
{ |
|
unsigned int text_shndx = exidx_input_section->link(); |
|
Output_section* os = arm_relobj->output_section(text_shndx); |
|
if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0) |
|
sorted_output_sections.insert(os); |
|
} |
|
} |
|
} |
|
|
|
// Go over the output sections in ascending order of output addresses. |
|
typedef typename Arm_output_section<big_endian>::Text_section_list |
|
Text_section_list; |
|
Text_section_list sorted_text_sections; |
|
for (typename Sorted_output_section_list::iterator p = |
|
sorted_output_sections.begin(); |
|
p != sorted_output_sections.end(); |
|
++p) |
|
{ |
|
Arm_output_section<big_endian>* arm_output_section = |
|
Arm_output_section<big_endian>::as_arm_output_section(*p); |
|
arm_output_section->append_text_sections_to_list(&sorted_text_sections); |
|
} |
|
|
|
exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab, |
|
merge_exidx_entries(), task); |
|
} |
|
|
|
template<bool big_endian> |
|
void |
|
Target_arm<big_endian>::do_define_standard_symbols( |
|
Symbol_table* symtab, |
|
Layout* layout) |
|
{ |
|
// Handle the .ARM.exidx section. |
|
Output_section* exidx_section = layout->find_output_section(".ARM.exidx"); |
|
|
|
if (exidx_section != NULL) |
|
{ |
|
// Create __exidx_start and __exidx_end symbols. |
|
symtab->define_in_output_data("__exidx_start", |
|
NULL, // version |
|
Symbol_table::PREDEFINED, |
|
exidx_section, |
|
0, // value |
|
0, // symsize |
|
elfcpp::STT_NOTYPE, |
|
elfcpp::STB_GLOBAL, |
|
elfcpp::STV_HIDDEN, |
|
0, // nonvis |
|
false, // offset_is_from_end |
|
true); // only_if_ref |
|
|
|
symtab->define_in_output_data("__exidx_end", |
|
NULL, // version |
|
Symbol_table::PREDEFINED, |
|
exidx_section, |
|
0, // value |
|
0, // symsize |
|
elfcpp::STT_NOTYPE, |
|
elfcpp::STB_GLOBAL, |
|
elfcpp::STV_HIDDEN, |
|
0, // nonvis |
|
true, // offset_is_from_end |
|
true); // only_if_ref |
|
} |
|
else |
|
{ |
|
// Define __exidx_start and __exidx_end even when .ARM.exidx |
|
// section is missing to match ld's behaviour. |
|
symtab->define_as_constant("__exidx_start", NULL, |
|
Symbol_table::PREDEFINED, |
|
0, 0, elfcpp::STT_OBJECT, |
|
elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0, |
|
true, false); |
|
symtab->define_as_constant("__exidx_end", NULL, |
|
Symbol_table::PREDEFINED, |
|
0, 0, elfcpp::STT_OBJECT, |
|
elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0, |
|
true, false); |
|
} |
|
} |
|
|
|
// NaCl variant. It uses different PLT contents. |
|
|
|
template<bool big_endian> |
|
class Output_data_plt_arm_nacl; |
|
|
|
template<bool big_endian> |
|
class Target_arm_nacl : public Target_arm<big_endian> |
|
{ |
|
public: |
|
Target_arm_nacl() |
|
: Target_arm<big_endian>(&arm_nacl_info) |
|
{ } |
|
|
|
protected: |
|
virtual Output_data_plt_arm<big_endian>* |
|
do_make_data_plt( |
|
Layout* layout, |
|
Arm_output_data_got<big_endian>* got, |
|
Output_data_space* got_plt, |
|
Output_data_space* got_irelative) |
|
{ return new Output_data_plt_arm_nacl<big_endian>( |
|
layout, got, got_plt, got_irelative); } |
|
|
|
private: |
|
static const Target::Target_info arm_nacl_info; |
|
}; |
|
|
|
template<bool big_endian> |
|
const Target::Target_info Target_arm_nacl<big_endian>::arm_nacl_info = |
|
{ |
|
32, // size |
|
big_endian, // is_big_endian |
|
elfcpp::EM_ARM, // machine_code |
|
false, // has_make_symbol |
|
false, // has_resolve |
|
false, // has_code_fill |
|
true, // is_default_stack_executable |
|
false, // can_icf_inline_merge_sections |
|
'\0', // wrap_char |
|
"/lib/ld-nacl-arm.so.1", // dynamic_linker |
|
0x20000, // default_text_segment_address |
|
0x10000, // abi_pagesize (overridable by -z max-page-size) |
|
0x10000, // common_pagesize (overridable by -z common-page-size) |
|
true, // isolate_execinstr |
|
0x10000000, // rosegment_gap |
|
elfcpp::SHN_UNDEF, // small_common_shndx |
|
elfcpp::SHN_UNDEF, // large_common_shndx |
|
0, // small_common_section_flags |
|
0, // large_common_section_flags |
|
".ARM.attributes", // attributes_section |
|
"aeabi", // attributes_vendor |
|
"_start" // entry_symbol_name |
|
}; |
|
|
|
template<bool big_endian> |
|
class Output_data_plt_arm_nacl : public Output_data_plt_arm<big_endian> |
|
{ |
|
public: |
|
Output_data_plt_arm_nacl( |
|
Layout* layout, |
|
Arm_output_data_got<big_endian>* got, |
|
Output_data_space* got_plt, |
|
Output_data_space* got_irelative) |
|
: Output_data_plt_arm<big_endian>(layout, 16, got, got_plt, got_irelative) |
|
{ } |
|
|
|
protected: |
|
// Return the offset of the first non-reserved PLT entry. |
|
virtual unsigned int |
|
do_first_plt_entry_offset() const |
|
{ return sizeof(first_plt_entry); } |
|
|
|
// Return the size of a PLT entry. |
|
virtual unsigned int |
|
do_get_plt_entry_size() const |
|
{ return sizeof(plt_entry); } |
|
|
|
virtual void |
|
do_fill_first_plt_entry(unsigned char* pov, |
|
Arm_address got_address, |
|
Arm_address plt_address); |
|
|
|
virtual void |
|
do_fill_plt_entry(unsigned char* pov, |
|
Arm_address got_address, |
|
Arm_address plt_address, |
|
unsigned int got_offset, |
|
unsigned int plt_offset); |
|
|
|
private: |
|
inline uint32_t arm_movw_immediate(uint32_t value) |
|
{ |
|
return (value & 0x00000fff) | ((value & 0x0000f000) << 4); |
|
} |
|
|
|
inline uint32_t arm_movt_immediate(uint32_t value) |
|
{ |
|
return ((value & 0x0fff0000) >> 16) | ((value & 0xf0000000) >> 12); |
|
} |
|
|
|
// Template for the first PLT entry. |
|
static const uint32_t first_plt_entry[16]; |
|
|
|
// Template for subsequent PLT entries. |
|
static const uint32_t plt_entry[4]; |
|
}; |
|
|
|
// The first entry in the PLT. |
|
template<bool big_endian> |
|
const uint32_t Output_data_plt_arm_nacl<big_endian>::first_plt_entry[16] = |
|
{ |
|
// First bundle: |
|
0xe300c000, // movw ip, #:lower16:&GOT[2]-.+8 |
|
0xe340c000, // movt ip, #:upper16:&GOT[2]-.+8 |
|
0xe08cc00f, // add ip, ip, pc |
|
0xe52dc008, // str ip, [sp, #-8]! |
|
// Second bundle: |
|
0xe3ccc103, // bic ip, ip, #0xc0000000 |
|
0xe59cc000, // ldr ip, [ip] |
|
0xe3ccc13f, // bic ip, ip, #0xc000000f |
|
0xe12fff1c, // bx ip |
|
// Third bundle: |
|
0xe320f000, // nop |
|
0xe320f000, // nop |
|
0xe320f000, // nop |
|
// .Lplt_tail: |
|
0xe50dc004, // str ip, [sp, #-4] |
|
// Fourth bundle: |
|
0xe3ccc103, // bic ip, ip, #0xc0000000 |
|
0xe59cc000, // ldr ip, [ip] |
|
0xe3ccc13f, // bic ip, ip, #0xc000000f |
|
0xe12fff1c, // bx ip |
|
}; |
|
|
|
template<bool big_endian> |
|
void |
|
Output_data_plt_arm_nacl<big_endian>::do_fill_first_plt_entry( |
|
unsigned char* pov, |
|
Arm_address got_address, |
|
Arm_address plt_address) |
|
{ |
|
// Write first PLT entry. All but first two words are constants. |
|
const size_t num_first_plt_words = (sizeof(first_plt_entry) |
|
/ sizeof(first_plt_entry[0])); |
|
|
|
int32_t got_displacement = got_address + 8 - (plt_address + 16); |
|
|
|
elfcpp::Swap<32, big_endian>::writeval |
|
(pov + 0, first_plt_entry[0] | arm_movw_immediate (got_displacement)); |
|
elfcpp::Swap<32, big_endian>::writeval |
|
(pov + 4, first_plt_entry[1] | arm_movt_immediate (got_displacement)); |
|
|
|
for (size_t i = 2; i < num_first_plt_words; ++i) |
|
elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]); |
|
} |
|
|
|
// Subsequent entries in the PLT. |
|
|
|
template<bool big_endian> |
|
const uint32_t Output_data_plt_arm_nacl<big_endian>::plt_entry[4] = |
|
{ |
|
0xe300c000, // movw ip, #:lower16:&GOT[n]-.+8 |
|
0xe340c000, // movt ip, #:upper16:&GOT[n]-.+8 |
|
0xe08cc00f, // add ip, ip, pc |
|
0xea000000, // b .Lplt_tail |
|
}; |
|
|
|
template<bool big_endian> |
|
void |
|
Output_data_plt_arm_nacl<big_endian>::do_fill_plt_entry( |
|
unsigned char* pov, |
|
Arm_address got_address, |
|
Arm_address plt_address, |
|
unsigned int got_offset, |
|
unsigned int plt_offset) |
|
{ |
|
// Calculate the displacement between the PLT slot and the |
|
// common tail that's part of the special initial PLT slot. |
|
int32_t tail_displacement = (plt_address + (11 * sizeof(uint32_t)) |
|
- (plt_address + plt_offset |
|
+ sizeof(plt_entry) + sizeof(uint32_t))); |
|
gold_assert((tail_displacement & 3) == 0); |
|
tail_displacement >>= 2; |
|
|
|
gold_assert ((tail_displacement & 0xff000000) == 0 |
|
|| (-tail_displacement & 0xff000000) == 0); |
|
|
|
// Calculate the displacement between the PLT slot and the entry |
|
// in the GOT. The offset accounts for the value produced by |
|
// adding to pc in the penultimate instruction of the PLT stub. |
|
const int32_t got_displacement = (got_address + got_offset |
|
- (plt_address + sizeof(plt_entry))); |
|
|
|
elfcpp::Swap<32, big_endian>::writeval |
|
(pov + 0, plt_entry[0] | arm_movw_immediate (got_displacement)); |
|
elfcpp::Swap<32, big_endian>::writeval |
|
(pov + 4, plt_entry[1] | arm_movt_immediate (got_displacement)); |
|
elfcpp::Swap<32, big_endian>::writeval |
|
(pov + 8, plt_entry[2]); |
|
elfcpp::Swap<32, big_endian>::writeval |
|
(pov + 12, plt_entry[3] | (tail_displacement & 0x00ffffff)); |
|
} |
|
|
|
// Target selectors. |
|
|
|
template<bool big_endian> |
|
class Target_selector_arm_nacl |
|
: public Target_selector_nacl<Target_selector_arm<big_endian>, |
|
Target_arm_nacl<big_endian> > |
|
{ |
|
public: |
|
Target_selector_arm_nacl() |
|
: Target_selector_nacl<Target_selector_arm<big_endian>, |
|
Target_arm_nacl<big_endian> >( |
|
"arm", |
|
big_endian ? "elf32-bigarm-nacl" : "elf32-littlearm-nacl", |
|
big_endian ? "armelfb_nacl" : "armelf_nacl") |
|
{ } |
|
}; |
|
|
|
Target_selector_arm_nacl<false> target_selector_arm; |
|
Target_selector_arm_nacl<true> target_selector_armbe; |
|
|
|
} // End anonymous namespace.
|
|
|