diff options
Diffstat (limited to 'arch/arm/lib/backtrace.S')
| -rw-r--r-- | arch/arm/lib/backtrace.S | 79 |
1 files changed, 29 insertions, 50 deletions
diff --git a/arch/arm/lib/backtrace.S b/arch/arm/lib/backtrace.S index cd07b5814c23..293a2716bd20 100644 --- a/arch/arm/lib/backtrace.S +++ b/arch/arm/lib/backtrace.S @@ -1,15 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ /* * 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/kern_levels.h> #include <linux/linkage.h> #include <asm/assembler.h> .text @@ -21,16 +18,18 @@ #define sv_pc r6 #define mask r7 #define offset r8 +#define loglvl r9 ENTRY(c_backtrace) #if !defined(CONFIG_FRAME_POINTER) || !defined(CONFIG_PRINTK) - mov pc, lr + ret lr ENDPROC(c_backtrace) #else - stmfd sp!, {r4 - r8, lr} @ Save an extra register so we have a location... + 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 ) @@ -69,39 +68,51 @@ for_each_frame: tst frame, mask @ Check for address exceptions 1003: ldr r2, [sv_pc, #-4] @ if stmfd sp!, {args} exists, ldr r3, .Ldsi+4 @ adjust saved 'pc' back one - teq r3, r2, lsr #10 @ instruction + 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 #10 + teq r3, r1, lsr #11 ldreq r0, [frame, #-8] @ get sp subeq r0, r0, #4 @ point at the last arg - bleq .Ldumpstm @ dump saved registers + 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 #10 + teq r3, r1, lsr #11 subeq r0, frame, #16 - bleq .Ldumpstm @ dump saved registers + 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, frame - bl printk -no_frame: ldmfd sp!, {r4 - r8, pc} + mov r1, loglvl + mov r2, frame + bl _printk +no_frame: ldmfd sp!, {r4 - r9, pc} ENDPROC(c_backtrace) .pushsection __ex_table,"a" @@ -112,41 +123,9 @@ ENDPROC(c_backtrace) .long 1004b, 1006b .popsection -#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, #10 - mov r7, #0 -1: mov r3, #1 - ARM( tst instr, r3, lsl reg ) - THUMB( lsl r3, reg ) - THUMB( tst instr, r3 ) - beq 2f - add r7, r7, #1 - teq r7, #6 - moveq r7, #1 - moveq r1, #'\n' - movne r1, #' ' - ldr r3, [stack], #-4 - mov r2, reg - adr r0, .Lfp - bl printk -2: subs reg, reg, #1 - bpl 1b - teq r7, #0 - adrne r0, .Lcr - blne printk - ldmfd sp!, {instr, reg, stack, r7, pc} - -.Lfp: .asciz "%cr%d:%08x" -.Lcr: .asciz "\n" -.Lbad: .asciz "Backtrace aborted due to bad frame pointer <%p>\n" +.Lbad: .asciz "%sBacktrace aborted due to bad frame pointer <%p>\n" .align -.Ldsi: .word 0xe92dd800 >> 10 @ stmfd sp!, {... fp, ip, lr, pc} - .word 0xe92d0000 >> 10 @ stmfd sp!, {} +.Ldsi: .word 0xe92dd800 >> 11 @ stmfd sp!, {... fp, ip, lr, pc} + .word 0xe92d0000 >> 11 @ stmfd sp!, {} #endif |