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299 lines
8.2 KiB
299 lines
8.2 KiB
/* Return section header. |
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Copyright (C) 1998-2002, 2005, 2007, 2009, 2012, 2014, 2015 Red Hat, Inc. |
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This file is part of elfutils. |
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Written by Ulrich Drepper <drepper@redhat.com>, 1998. |
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This file is free software; you can redistribute it and/or modify |
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it under the terms of either |
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* the GNU Lesser General Public License as published by the Free |
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Software Foundation; either version 3 of the License, or (at |
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your option) any later version |
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or |
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* the GNU General Public License as published by the Free |
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Software Foundation; either version 2 of the License, or (at |
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your option) any later version |
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or both in parallel, as here. |
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elfutils is distributed in the hope that it will be useful, but |
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WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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General Public License for more details. |
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You should have received copies of the GNU General Public License and |
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the GNU Lesser General Public License along with this program. If |
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not, see <http://www.gnu.org/licenses/>. */ |
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#ifdef HAVE_CONFIG_H |
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# include <config.h> |
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#endif |
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#include <assert.h> |
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#include <errno.h> |
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#include <stdbool.h> |
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#include <unistd.h> |
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#include <system.h> |
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#include "libelfP.h" |
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#include "common.h" |
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#ifndef LIBELFBITS |
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# define LIBELFBITS 32 |
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#endif |
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static ElfW2(LIBELFBITS,Shdr) * |
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load_shdr_wrlock (Elf_Scn *scn) |
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{ |
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ElfW2(LIBELFBITS,Shdr) *result; |
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/* Read the section header table. */ |
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Elf *elf = scn->elf; |
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ElfW2(LIBELFBITS,Ehdr) *ehdr = elf->state.ELFW(elf,LIBELFBITS).ehdr; |
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/* Try again, maybe the data is there now. */ |
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result = scn->shdr.ELFW(e,LIBELFBITS); |
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if (result != NULL) |
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goto out; |
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size_t shnum; |
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if (__elf_getshdrnum_rdlock (elf, &shnum) != 0 |
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|| shnum > SIZE_MAX / sizeof (ElfW2(LIBELFBITS,Shdr))) |
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goto out; |
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size_t size = shnum * sizeof (ElfW2(LIBELFBITS,Shdr)); |
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/* Allocate memory for the section headers. We know the number |
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of entries from the ELF header. */ |
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ElfW2(LIBELFBITS,Shdr) *shdr = elf->state.ELFW(elf,LIBELFBITS).shdr = |
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(ElfW2(LIBELFBITS,Shdr) *) malloc (size); |
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if (elf->state.ELFW(elf,LIBELFBITS).shdr == NULL) |
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{ |
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__libelf_seterrno (ELF_E_NOMEM); |
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goto out; |
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} |
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elf->state.ELFW(elf,LIBELFBITS).shdr_malloced = 1; |
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if (elf->map_address != NULL) |
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{ |
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/* First see whether the information in the ELF header is |
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valid and it does not ask for too much. */ |
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if (unlikely (ehdr->e_shoff >= elf->maximum_size) |
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|| unlikely (elf->maximum_size - ehdr->e_shoff < size)) |
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{ |
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/* Something is wrong. */ |
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__libelf_seterrno (ELF_E_INVALID_SECTION_HEADER); |
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goto free_and_out; |
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} |
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ElfW2(LIBELFBITS,Shdr) *notcvt; |
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/* All the data is already mapped. If we could use it |
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directly this would already have happened. Unless |
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we allocated the memory ourselves and the ELF_F_MALLOCED |
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flag is set. */ |
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void *file_shdr = ((char *) elf->map_address |
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+ elf->start_offset + ehdr->e_shoff); |
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assert ((elf->flags & ELF_F_MALLOCED) |
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|| ehdr->e_ident[EI_DATA] != MY_ELFDATA |
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|| elf->cmd == ELF_C_READ_MMAP |
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|| (! ALLOW_UNALIGNED |
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&& ((uintptr_t) file_shdr |
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& (__alignof__ (ElfW2(LIBELFBITS,Shdr)) - 1)) != 0)); |
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/* Now copy the data and at the same time convert the byte order. */ |
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if (ehdr->e_ident[EI_DATA] == MY_ELFDATA) |
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{ |
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assert ((elf->flags & ELF_F_MALLOCED) |
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|| elf->cmd == ELF_C_READ_MMAP |
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|| ! ALLOW_UNALIGNED); |
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memcpy (shdr, file_shdr, size); |
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} |
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else |
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{ |
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bool copy = ! (ALLOW_UNALIGNED |
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|| ((uintptr_t) file_shdr |
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& (__alignof__ (ElfW2(LIBELFBITS,Shdr)) - 1)) |
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== 0); |
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if (! copy) |
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notcvt = (ElfW2(LIBELFBITS,Shdr) *) |
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((char *) elf->map_address |
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+ elf->start_offset + ehdr->e_shoff); |
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else |
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{ |
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notcvt = (ElfW2(LIBELFBITS,Shdr) *) malloc (size); |
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if (unlikely (notcvt == NULL)) |
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{ |
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__libelf_seterrno (ELF_E_NOMEM); |
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goto out; |
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} |
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memcpy (notcvt, ((char *) elf->map_address |
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+ elf->start_offset + ehdr->e_shoff), |
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size); |
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} |
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for (size_t cnt = 0; cnt < shnum; ++cnt) |
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{ |
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CONVERT_TO (shdr[cnt].sh_name, notcvt[cnt].sh_name); |
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CONVERT_TO (shdr[cnt].sh_type, notcvt[cnt].sh_type); |
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CONVERT_TO (shdr[cnt].sh_flags, notcvt[cnt].sh_flags); |
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CONVERT_TO (shdr[cnt].sh_addr, notcvt[cnt].sh_addr); |
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CONVERT_TO (shdr[cnt].sh_offset, notcvt[cnt].sh_offset); |
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CONVERT_TO (shdr[cnt].sh_size, notcvt[cnt].sh_size); |
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CONVERT_TO (shdr[cnt].sh_link, notcvt[cnt].sh_link); |
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CONVERT_TO (shdr[cnt].sh_info, notcvt[cnt].sh_info); |
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CONVERT_TO (shdr[cnt].sh_addralign, |
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notcvt[cnt].sh_addralign); |
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CONVERT_TO (shdr[cnt].sh_entsize, notcvt[cnt].sh_entsize); |
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/* If this is a section with an extended index add a |
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reference in the section which uses the extended |
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index. */ |
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if (shdr[cnt].sh_type == SHT_SYMTAB_SHNDX |
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&& shdr[cnt].sh_link < shnum) |
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elf->state.ELFW(elf,LIBELFBITS).scns.data[shdr[cnt].sh_link].shndx_index |
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= cnt; |
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/* Set the own shndx_index field in case it has not yet |
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been set. */ |
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if (elf->state.ELFW(elf,LIBELFBITS).scns.data[cnt].shndx_index == 0) |
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elf->state.ELFW(elf,LIBELFBITS).scns.data[cnt].shndx_index |
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= -1; |
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} |
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if (copy) |
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free (notcvt); |
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} |
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} |
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else if (likely (elf->fildes != -1)) |
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{ |
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/* Read the header. */ |
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ssize_t n = pread_retry (elf->fildes, |
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elf->state.ELFW(elf,LIBELFBITS).shdr, size, |
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elf->start_offset + ehdr->e_shoff); |
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if (unlikely ((size_t) n != size)) |
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{ |
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/* Severe problems. We cannot read the data. */ |
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__libelf_seterrno (ELF_E_READ_ERROR); |
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goto free_and_out; |
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} |
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/* If the byte order of the file is not the same as the one |
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of the host convert the data now. */ |
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if (ehdr->e_ident[EI_DATA] != MY_ELFDATA) |
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for (size_t cnt = 0; cnt < shnum; ++cnt) |
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{ |
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CONVERT (shdr[cnt].sh_name); |
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CONVERT (shdr[cnt].sh_type); |
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CONVERT (shdr[cnt].sh_flags); |
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CONVERT (shdr[cnt].sh_addr); |
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CONVERT (shdr[cnt].sh_offset); |
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CONVERT (shdr[cnt].sh_size); |
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CONVERT (shdr[cnt].sh_link); |
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CONVERT (shdr[cnt].sh_info); |
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CONVERT (shdr[cnt].sh_addralign); |
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CONVERT (shdr[cnt].sh_entsize); |
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} |
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} |
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else |
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{ |
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/* The file descriptor was already enabled and not all data was |
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read. Undo the allocation. */ |
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__libelf_seterrno (ELF_E_FD_DISABLED); |
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free_and_out: |
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free (shdr); |
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elf->state.ELFW(elf,LIBELFBITS).shdr = NULL; |
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elf->state.ELFW(elf,LIBELFBITS).shdr_malloced = 0; |
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goto out; |
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} |
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/* Set the pointers in the `scn's. */ |
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for (size_t cnt = 0; cnt < shnum; ++cnt) |
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elf->state.ELFW(elf,LIBELFBITS).scns.data[cnt].shdr.ELFW(e,LIBELFBITS) |
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= &elf->state.ELFW(elf,LIBELFBITS).shdr[cnt]; |
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result = scn->shdr.ELFW(e,LIBELFBITS); |
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assert (result != NULL); |
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out: |
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return result; |
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} |
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static bool |
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scn_valid (Elf_Scn *scn) |
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{ |
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if (scn == NULL) |
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return false; |
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if (unlikely (scn->elf->state.elf.ehdr == NULL)) |
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{ |
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__libelf_seterrno (ELF_E_WRONG_ORDER_EHDR); |
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return false; |
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} |
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if (unlikely (scn->elf->class != ELFW(ELFCLASS,LIBELFBITS))) |
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{ |
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__libelf_seterrno (ELF_E_INVALID_CLASS); |
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return false; |
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} |
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return true; |
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} |
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ElfW2(LIBELFBITS,Shdr) * |
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internal_function |
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__elfw2(LIBELFBITS,getshdr_rdlock) (Elf_Scn *scn) |
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{ |
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ElfW2(LIBELFBITS,Shdr) *result; |
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if (!scn_valid (scn)) |
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return NULL; |
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result = scn->shdr.ELFW(e,LIBELFBITS); |
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if (result == NULL) |
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{ |
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rwlock_unlock (scn->elf->lock); |
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rwlock_wrlock (scn->elf->lock); |
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result = scn->shdr.ELFW(e,LIBELFBITS); |
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if (result == NULL) |
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result = load_shdr_wrlock (scn); |
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} |
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return result; |
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} |
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ElfW2(LIBELFBITS,Shdr) * |
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internal_function |
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__elfw2(LIBELFBITS,getshdr_wrlock) (Elf_Scn *scn) |
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{ |
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ElfW2(LIBELFBITS,Shdr) *result; |
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if (!scn_valid (scn)) |
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return NULL; |
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result = scn->shdr.ELFW(e,LIBELFBITS); |
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if (result == NULL) |
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result = load_shdr_wrlock (scn); |
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return result; |
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} |
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ElfW2(LIBELFBITS,Shdr) * |
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elfw2(LIBELFBITS,getshdr) (Elf_Scn *scn) |
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{ |
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ElfW2(LIBELFBITS,Shdr) *result; |
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if (!scn_valid (scn)) |
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return NULL; |
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rwlock_rdlock (scn->elf->lock); |
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result = __elfw2(LIBELFBITS,getshdr_rdlock) (scn); |
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rwlock_unlock (scn->elf->lock); |
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return result; |
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}
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