linux/arch/arm/lib/backtrace.S
Russell King 583e7f5d36 [ARM] nommu: backtrace code must not reference a discarded section
The code in "1007:" is in the .fixup section, which in the mmuless
case is discarded.  Since this code is referenced from the .text
section, it causes an link error.  Move this code into the .text
section instead.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-28 17:59:57 +01:00

155 lines
3.1 KiB
ArmAsm

/*
* 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.
*
* 27/03/03 Ian Molton Clean up CONFIG_CPU
*
*/
#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)
#if !defined(CONFIG_FRAME_POINTER) || !defined(CONFIG_PRINTK)
mov pc, lr
#else
stmfd sp!, {r4 - r8, lr} @ Save an extra register so we have a location...
tst r1, #0x10 @ 26 or 32-bit?
moveq mask, #0xfc000003
movne mask, #0
tst mask, r0
movne r0, #0
movs frame, r0
1: moveq r0, #-2
ldmeqfd 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: ldr next, [frame, #-12] @ get fp
1002: ldr r2, [frame, #-4] @ get lr
1003: ldr r3, [frame, #0] @ get pc
sub save, r3, offset @ Correct PC for prefetching
bic save, save, mask
1004: ldr r1, [save, #0] @ get instruction at function
mov r1, r1, lsr #10
ldr r3, .Ldsi+4
teq r1, r3
subeq save, save, #4
mov r0, save
bic r1, r2, mask
bl dump_backtrace_entry
ldr r0, [frame, #-8] @ get sp
sub r0, r0, #4
1005: 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
sub r0, frame, #16
1006: 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
/*
* A zero next framepointer means we're done.
*/
teq next, #0
ldmeqfd sp!, {r4 - r8, pc}
/*
* The next framepointer must be above the
* current framepointer.
*/
cmp next, frame
mov frame, next
bhi 3b
b 1007f
/*
* Fixup for LDMDB. Note that this must not be in the fixup section.
*/
1007: ldr r0, =.Lbad
mov r1, frame
bl printk
ldmfd sp!, {r4 - r8, pc}
.ltorg
.section __ex_table,"a"
.align 3
.long 1001b, 1007b
.long 1002b, 1007b
.long 1003b, 1007b
.long 1004b, 1007b
.long 1005b, 1007b
.long 1006b, 1007b
.previous
#define instr r4
#define reg r5
#define stack r6
.Ldumpstm: stmfd sp!, {instr, reg, stack, r7, r8, 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 printk
2: subs reg, reg, #1
bpl 1b
teq r7, #0
adrne r0, .Lcr
blne printk
mov r0, stack
ldmfd sp!, {instr, reg, stack, r7, r8, pc}
.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