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/*
* linux/arch/arm/lib/backtrace.S
*
* Copyright (C) 1995, 1996 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/config.h>
#include <linux/linkage.h>
#include <asm/assembler.h>
.text
@ fp is 0 or stack frame
#define frame r4
#define next r5
#define save r6
#define mask r7
#define offset r8
ENTRY(__backtrace)
mov r1, #0x10
mov r0, fp
ENTRY(c_backtrace)
#ifdef CONFIG_NO_FRAME_POINTER
mov pc, lr
#else
stmfd sp!, {r4 - r8, lr} @ Save an extra register so we have a location...
#ifdef CONFIG_CPU_32
tst r1, #0x10 @ 26 or 32-bit?
moveq mask, #0xfc000003
movne mask, #0
#else
mov mask, #0xfc000003
#endif
tst mask, r0
movne r0, #0
movs frame, r0
1: moveq r0, #-2
LOADREGS(eqfd, sp!, {r4 - r8, pc})
2: stmfd sp!, {pc} @ calculate offset of PC in STMIA instruction
ldr r0, [sp], #4
adr r1, 2b - 4
sub offset, r0, r1
3: tst frame, mask @ Check for address exceptions...
bne 1b
1001: ldmda frame, {r0, r1, r2, r3} @ fp, sp, lr, pc
mov next, r0
sub save, r3, offset @ Correct PC for prefetching
bic save, save, mask
adr r0, .Lfe
mov r1, save
bic r2, r2, mask
bl SYMBOL_NAME(printk) @ print pc and link register
sub r0, frame, #16
1002: ldr r1, [save, #4] @ get instruction at function+4
mov r3, r1, lsr #10
ldr r2, .Ldsi+4
teq r3, r2 @ Check for stmia sp!, {args}
addeq save, save, #4 @ next instruction
bleq .Ldumpstm
1003: ldr r1, [save, #4] @ Get 'stmia sp!, {rlist, fp, ip, lr, pc}' instruction
mov r3, r1, lsr #10
ldr r2, .Ldsi
teq r3, r2
bleq .Ldumpstm
teq frame, next
movne frame, next
teqne frame, #0
bne 3b
LOADREGS(fd, sp!, {r4 - r8, pc})
/*
* Fixup for LDMDB
*/
.section .fixup,"ax"
.align 0
1004: ldr r0, =.Lbad
mov r1, frame
bl SYMBOL_NAME(printk)
LOADREGS(fd, sp!, {r4 - r8, pc})
.ltorg
.previous
.section __ex_table,"a"
.align 3
.long 1001b, 1004b
.long 1002b, 1004b
.long 1003b, 1004b
.previous
#define instr r4
#define reg r5
#define stack r6
.Ldumpstm: stmfd sp!, {instr, reg, stack, r7, lr}
mov stack, r0
mov instr, r1
mov reg, #9
mov r7, #0
1: mov r3, #1
tst instr, r3, lsl reg
beq 2f
add r7, r7, #1
teq r7, #4
moveq r7, #0
moveq r3, #'\n'
movne r3, #' '
ldr r2, [stack], #-4
mov r1, reg
adr r0, .Lfp
bl SYMBOL_NAME(printk)
2: subs reg, reg, #1
bpl 1b
teq r7, #0
adrne r0, .Lcr
blne SYMBOL_NAME(printk)
mov r0, stack
LOADREGS(fd, sp!, {instr, reg, stack, r7, pc})
.Lfe: .asciz "Function entered at [<%p>] from [<%p>]\n"
.Lfp: .asciz " r%d = %08X%c"
.Lcr: .asciz "\n"
.Lbad: .asciz "Backtrace aborted due to bad frame pointer <%p>\n"
.align
.Ldsi: .word 0x00e92dd8 >> 2
.word 0x00e92d00 >> 2
#endif
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