diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/arm/lib/backtrace.S | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm/lib/backtrace.S')
-rw-r--r-- | arch/arm/lib/backtrace.S | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/arch/arm/lib/backtrace.S b/arch/arm/lib/backtrace.S new file mode 100644 index 000000000..293a2716b --- /dev/null +++ b/arch/arm/lib/backtrace.S @@ -0,0 +1,131 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * linux/arch/arm/lib/backtrace.S + * + * Copyright (C) 1995, 1996 Russell King + * + * 27/03/03 Ian Molton Clean up CONFIG_CPU + */ +#include <linux/kern_levels.h> +#include <linux/linkage.h> +#include <asm/assembler.h> + .text + +@ fp is 0 or stack frame + +#define frame r4 +#define sv_fp r5 +#define sv_pc r6 +#define mask r7 +#define offset r8 +#define loglvl r9 + +ENTRY(c_backtrace) + +#if !defined(CONFIG_FRAME_POINTER) || !defined(CONFIG_PRINTK) + ret lr +ENDPROC(c_backtrace) +#else + stmfd sp!, {r4 - r9, lr} @ Save an extra register so we have a location... + movs frame, r0 @ if frame pointer is zero + beq no_frame @ we have no stack frames + mov loglvl, r2 + + tst r1, #0x10 @ 26 or 32-bit mode? + ARM( moveq mask, #0xfc000003 ) + THUMB( moveq mask, #0xfc000000 ) + THUMB( orreq mask, #0x03 ) + movne mask, #0 @ mask for 32-bit + +1: stmfd sp!, {pc} @ calculate offset of PC stored + ldr r0, [sp], #4 @ by stmfd for this CPU + adr r1, 1b + sub offset, r0, r1 + +/* + * Stack frame layout: + * optionally saved caller registers (r4 - r10) + * saved fp + * saved sp + * saved lr + * frame => saved pc + * optionally saved arguments (r0 - r3) + * saved sp => <next word> + * + * Functions start with the following code sequence: + * mov ip, sp + * stmfd sp!, {r0 - r3} (optional) + * corrected pc => stmfd sp!, {..., fp, ip, lr, pc} + */ +for_each_frame: tst frame, mask @ Check for address exceptions + bne no_frame + +1001: ldr sv_pc, [frame, #0] @ get saved pc +1002: ldr sv_fp, [frame, #-12] @ get saved fp + + sub sv_pc, sv_pc, offset @ Correct PC for prefetching + bic sv_pc, sv_pc, mask @ mask PC/LR for the mode + +1003: ldr r2, [sv_pc, #-4] @ if stmfd sp!, {args} exists, + ldr r3, .Ldsi+4 @ adjust saved 'pc' back one + teq r3, r2, lsr #11 @ instruction + subne r0, sv_pc, #4 @ allow for mov + subeq r0, sv_pc, #8 @ allow for mov + stmia + + ldr r1, [frame, #-4] @ get saved lr + mov r2, frame + bic r1, r1, mask @ mask PC/LR for the mode + mov r3, loglvl + bl dump_backtrace_entry + + ldr r1, [sv_pc, #-4] @ if stmfd sp!, {args} exists, + ldr r3, .Ldsi+4 + teq r3, r1, lsr #11 + ldreq r0, [frame, #-8] @ get sp + subeq r0, r0, #4 @ point at the last arg + mov r2, loglvl + bleq dump_backtrace_stm @ dump saved registers + +1004: ldr r1, [sv_pc, #0] @ if stmfd sp!, {..., fp, ip, lr, pc} + ldr r3, .Ldsi @ instruction exists, + teq r3, r1, lsr #11 + subeq r0, frame, #16 + mov r2, loglvl + bleq dump_backtrace_stm @ dump saved registers + + teq sv_fp, #0 @ zero saved fp means + beq no_frame @ no further frames + + cmp sv_fp, frame @ next frame must be + mov frame, sv_fp @ above the current frame +#ifdef CONFIG_IRQSTACKS + @ + @ Kernel stacks may be discontiguous in memory. If the next + @ frame is below the previous frame, accept it as long as it + @ lives in kernel memory. + @ + cmpls sv_fp, #PAGE_OFFSET +#endif + bhi for_each_frame + +1006: adr r0, .Lbad + mov r1, loglvl + mov r2, frame + bl _printk +no_frame: ldmfd sp!, {r4 - r9, pc} +ENDPROC(c_backtrace) + + .pushsection __ex_table,"a" + .align 3 + .long 1001b, 1006b + .long 1002b, 1006b + .long 1003b, 1006b + .long 1004b, 1006b + .popsection + +.Lbad: .asciz "%sBacktrace aborted due to bad frame pointer <%p>\n" + .align +.Ldsi: .word 0xe92dd800 >> 11 @ stmfd sp!, {... fp, ip, lr, pc} + .word 0xe92d0000 >> 11 @ stmfd sp!, {} + +#endif |