diff options
Diffstat (limited to 'arch/arm/lib/backtrace.S')
| -rw-r--r-- | arch/arm/lib/backtrace.S | 32 |
1 files changed, 21 insertions, 11 deletions
diff --git a/arch/arm/lib/backtrace.S b/arch/arm/lib/backtrace.S index 7d7952e5a3b1..293a2716bd20 100644 --- a/arch/arm/lib/backtrace.S +++ b/arch/arm/lib/backtrace.S @@ -1,14 +1,10 @@ +/* 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> @@ -22,6 +18,7 @@ #define sv_pc r6 #define mask r7 #define offset r8 +#define loglvl r9 ENTRY(c_backtrace) @@ -29,9 +26,10 @@ ENTRY(c_backtrace) 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 ) @@ -70,13 +68,14 @@ 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, @@ -84,12 +83,14 @@ for_each_frame: tst frame, mask @ Check for address exceptions 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 @@ -97,12 +98,21 @@ for_each_frame: tst frame, mask @ Check for address exceptions 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" @@ -113,7 +123,7 @@ ENDPROC(c_backtrace) .long 1004b, 1006b .popsection -.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 >> 11 @ stmfd sp!, {... fp, ip, lr, pc} .word 0xe92d0000 >> 11 @ stmfd sp!, {} |