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179 lines
4.1 KiB
179 lines
4.1 KiB
/* |
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* linux/arch/arm/lib/backtrace.S |
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* |
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* Copyright (C) 1995, 1996 Russell King |
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* |
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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 version 2 as |
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* published by the Free Software Foundation. |
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* |
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* 27/03/03 Ian Molton Clean up CONFIG_CPU |
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* |
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*/ |
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#include <linux/linkage.h> |
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#include <asm/assembler.h> |
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#include <asm/thread_info.h> |
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#include <linux/const.h> |
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.extern _stext, _etext |
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__stext: |
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.word _stext |
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__etext: |
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.word _etext |
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.text |
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@ fp is 0 or stack frame |
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#define frame r4 |
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#define sv_fp r5 |
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#define sv_pc r6 |
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#define mask r7 |
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#define offset r8 |
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ENTRY(c_backtrace) |
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#if !defined(CONFIG_FRAME_POINTER) || !defined(CONFIG_PRINTK) |
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ret lr |
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ENDPROC(c_backtrace) |
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#else |
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stmfd sp!, {r4 - r8, lr} @ Save an extra register so we have a location... |
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movs frame, r0 @ if frame pointer is zero |
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beq no_frame @ we have no stack frames |
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tst r1, #0x10 @ 26 or 32-bit mode? |
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ARM( moveq mask, #0xfc000003 ) |
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THUMB( moveq mask, #0xfc000000 ) |
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THUMB( orreq mask, #0x03 ) |
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movne mask, #0 @ mask for 32-bit |
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1: stmfd sp!, {pc} @ calculate offset of PC stored |
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ldr r0, [sp], #4 @ by stmfd for this CPU |
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adr r1, 1b |
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sub offset, r0, r1 |
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/* |
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* Stack frame layout: |
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* optionally saved caller registers (r4 - r10) |
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* saved fp |
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* saved sp |
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* saved lr |
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* frame => saved pc |
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* optionally saved arguments (r0 - r3) |
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* saved sp => <next word> |
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* |
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* Functions start with the following code sequence: |
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* mov ip, sp |
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* stmfd sp!, {r0 - r3} (optional) |
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* corrected pc => stmfd sp!, {..., fp, ip, lr, pc} |
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*/ |
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for_each_frame: tst frame, mask @ Check for address exceptions |
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bne no_frame |
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1001: ldr sv_pc, [frame, #0] @ get saved pc |
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1002: ldr sv_fp, [frame, #-12] @ get saved fp |
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sub sv_pc, sv_pc, offset @ Correct PC for prefetching |
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bic sv_pc, sv_pc, mask @ mask PC/LR for the mode |
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ldr r0, __stext |
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cmp sv_pc, r0 |
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blo .badpc |
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ldr r0, __etext |
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cmp sv_pc, r0 |
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bhs .badpc |
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1003: ldr r2, [sv_pc, #-4] @ if stmfd sp!, {args} exists, |
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ldr r3, .Ldsi+4 @ adjust saved 'pc' back one |
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teq r3, r2, lsr #10 @ instruction |
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subne r0, sv_pc, #4 @ allow for mov |
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subeq r0, sv_pc, #8 @ allow for mov + stmia |
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ldr r1, [frame, #-4] @ get saved lr |
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mov r2, frame |
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bic r1, r1, mask @ mask PC/LR for the mode |
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bl dump_backtrace_entry |
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ldr r1, [sv_pc, #-4] @ if stmfd sp!, {args} exists, |
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ldr r3, .Ldsi+4 |
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teq r3, r1, lsr #11 |
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ldreq r0, [frame, #-8] @ get sp |
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subeq r0, r0, #4 @ point at the last arg |
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bleq .Ldumpstm @ dump saved registers |
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1004: ldr r1, [sv_pc, #0] @ if stmfd sp!, {..., fp, ip, lr, pc} |
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ldr r3, .Ldsi @ instruction exists, |
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teq r3, r1, lsr #11 |
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subeq r0, frame, #16 |
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bleq .Ldumpstm @ dump saved registers |
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teq sv_fp, #0 @ zero saved fp means |
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beq no_frame @ no further frames |
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cmp sv_fp, frame @ next frame must be |
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mov frame, sv_fp @ above the current frame |
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bhi for_each_frame |
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1006: adr r0, .Lbad |
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mov r1, frame |
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bl printk |
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no_frame: ldmfd sp!, {r4 - r8, pc} |
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ENDPROC(c_backtrace) |
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.pushsection __ex_table,"a" |
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.align 3 |
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.long 1001b, 1006b |
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.long 1002b, 1006b |
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.long 1003b, 1006b |
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.long 1004b, 1006b |
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.popsection |
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#define instr r4 |
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#define reg r5 |
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#define stack r6 |
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.badpc: |
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adr r0, .Lbadpc |
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mov r1, sv_pc |
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bl printk |
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b no_frame |
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.Ldumpstm: stmfd sp!, {instr, reg, stack, r7, lr} |
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mov stack, r0 |
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mov instr, r1 |
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eor r0, stack, sv_fp |
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cmp r0, #(THREAD_SIZE) |
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bhs 2f |
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mov reg, #10 |
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mov r7, #0 |
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1: mov r3, #1 |
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ARM( tst instr, r3, lsl reg ) |
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THUMB( lsl r3, reg ) |
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THUMB( tst instr, r3 ) |
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beq 2f |
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tst stack, mask |
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bne 2f |
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add r7, r7, #1 |
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teq r7, #6 |
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moveq r7, #0 |
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adr r3, .Lcr |
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addne r3, r3, #1 @ skip newline |
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ldr r2, [stack], #-4 |
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mov r1, reg |
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adr r0, .Lfp |
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bl printk |
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2: subs reg, reg, #1 |
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bpl 1b |
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teq r7, #0 |
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adrne r0, .Lcr |
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blne printk |
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ldmfd sp!, {instr, reg, stack, r7, pc} |
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.Lfp: .asciz " r%d:%08x%s" |
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.Lcr: .asciz "\n" |
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.Lbad: .asciz "Backtrace aborted due to bad frame pointer <%p>\n" |
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.align |
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.Lbadpc: .asciz "Backtrace aborted due to bad pc <%p>\n" |
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.align |
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.Ldsi: .word 0xe92dd800 >> 11 @ stmfd sp!, {... fp, ip, lr, pc} |
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.word 0xe92d0000 >> 11 @ stmfd sp!, {} |
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#endif
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