Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/arch/arm/lib/backtrace.S |
| 3 | * |
| 4 | * Copyright (C) 1995, 1996 Russell King |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | * |
| 10 | * 27/03/03 Ian Molton Clean up CONFIG_CPU |
| 11 | * |
| 12 | */ |
| 13 | #include <linux/config.h> |
| 14 | #include <linux/linkage.h> |
| 15 | #include <asm/assembler.h> |
| 16 | .text |
| 17 | |
| 18 | @ fp is 0 or stack frame |
| 19 | |
| 20 | #define frame r4 |
| 21 | #define next r5 |
| 22 | #define save r6 |
| 23 | #define mask r7 |
| 24 | #define offset r8 |
| 25 | |
| 26 | ENTRY(__backtrace) |
| 27 | mov r1, #0x10 |
| 28 | mov r0, fp |
| 29 | |
| 30 | ENTRY(c_backtrace) |
| 31 | |
Malcolm Parsons | 3ee357f | 2006-03-25 21:58:03 +0000 | [diff] [blame] | 32 | #if !defined(CONFIG_FRAME_POINTER) || !defined(CONFIG_PRINTK) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | mov pc, lr |
| 34 | #else |
| 35 | |
| 36 | stmfd sp!, {r4 - r8, lr} @ Save an extra register so we have a location... |
| 37 | tst r1, #0x10 @ 26 or 32-bit? |
| 38 | moveq mask, #0xfc000003 |
| 39 | movne mask, #0 |
| 40 | tst mask, r0 |
| 41 | movne r0, #0 |
| 42 | movs frame, r0 |
| 43 | 1: moveq r0, #-2 |
| 44 | LOADREGS(eqfd, sp!, {r4 - r8, pc}) |
| 45 | |
| 46 | 2: stmfd sp!, {pc} @ calculate offset of PC in STMIA instruction |
| 47 | ldr r0, [sp], #4 |
| 48 | adr r1, 2b - 4 |
| 49 | sub offset, r0, r1 |
| 50 | |
| 51 | 3: tst frame, mask @ Check for address exceptions... |
| 52 | bne 1b |
| 53 | |
| 54 | 1001: ldr next, [frame, #-12] @ get fp |
| 55 | 1002: ldr r2, [frame, #-4] @ get lr |
| 56 | 1003: ldr r3, [frame, #0] @ get pc |
| 57 | sub save, r3, offset @ Correct PC for prefetching |
| 58 | bic save, save, mask |
| 59 | 1004: ldr r1, [save, #0] @ get instruction at function |
| 60 | mov r1, r1, lsr #10 |
| 61 | ldr r3, .Ldsi+4 |
| 62 | teq r1, r3 |
| 63 | subeq save, save, #4 |
| 64 | mov r0, save |
| 65 | bic r1, r2, mask |
| 66 | bl dump_backtrace_entry |
| 67 | |
| 68 | ldr r0, [frame, #-8] @ get sp |
| 69 | sub r0, r0, #4 |
| 70 | 1005: ldr r1, [save, #4] @ get instruction at function+4 |
| 71 | mov r3, r1, lsr #10 |
| 72 | ldr r2, .Ldsi+4 |
| 73 | teq r3, r2 @ Check for stmia sp!, {args} |
| 74 | addeq save, save, #4 @ next instruction |
| 75 | bleq .Ldumpstm |
| 76 | |
| 77 | sub r0, frame, #16 |
| 78 | 1006: ldr r1, [save, #4] @ Get 'stmia sp!, {rlist, fp, ip, lr, pc}' instruction |
| 79 | mov r3, r1, lsr #10 |
| 80 | ldr r2, .Ldsi |
| 81 | teq r3, r2 |
| 82 | bleq .Ldumpstm |
| 83 | |
| 84 | /* |
| 85 | * A zero next framepointer means we're done. |
| 86 | */ |
| 87 | teq next, #0 |
| 88 | LOADREGS(eqfd, sp!, {r4 - r8, pc}) |
| 89 | |
| 90 | /* |
| 91 | * The next framepointer must be above the |
| 92 | * current framepointer. |
| 93 | */ |
| 94 | cmp next, frame |
| 95 | mov frame, next |
| 96 | bhi 3b |
| 97 | b 1007f |
| 98 | |
| 99 | /* |
| 100 | * Fixup for LDMDB |
| 101 | */ |
| 102 | .section .fixup,"ax" |
| 103 | .align 0 |
| 104 | 1007: ldr r0, =.Lbad |
| 105 | mov r1, frame |
| 106 | bl printk |
| 107 | LOADREGS(fd, sp!, {r4 - r8, pc}) |
| 108 | .ltorg |
| 109 | .previous |
| 110 | |
| 111 | .section __ex_table,"a" |
| 112 | .align 3 |
| 113 | .long 1001b, 1007b |
| 114 | .long 1002b, 1007b |
| 115 | .long 1003b, 1007b |
| 116 | .long 1004b, 1007b |
| 117 | .long 1005b, 1007b |
| 118 | .long 1006b, 1007b |
| 119 | .previous |
| 120 | |
| 121 | #define instr r4 |
| 122 | #define reg r5 |
| 123 | #define stack r6 |
| 124 | |
Nicolas Pitre | 1d6760a | 2006-05-16 11:29:46 +0100 | [diff] [blame] | 125 | .Ldumpstm: stmfd sp!, {instr, reg, stack, r7, r8, lr} |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | mov stack, r0 |
| 127 | mov instr, r1 |
| 128 | mov reg, #9 |
| 129 | mov r7, #0 |
| 130 | 1: mov r3, #1 |
| 131 | tst instr, r3, lsl reg |
| 132 | beq 2f |
| 133 | add r7, r7, #1 |
| 134 | teq r7, #4 |
| 135 | moveq r7, #0 |
| 136 | moveq r3, #'\n' |
| 137 | movne r3, #' ' |
| 138 | ldr r2, [stack], #-4 |
| 139 | mov r1, reg |
| 140 | adr r0, .Lfp |
| 141 | bl printk |
| 142 | 2: subs reg, reg, #1 |
| 143 | bpl 1b |
| 144 | teq r7, #0 |
| 145 | adrne r0, .Lcr |
| 146 | blne printk |
| 147 | mov r0, stack |
Nicolas Pitre | 1d6760a | 2006-05-16 11:29:46 +0100 | [diff] [blame] | 148 | LOADREGS(fd, sp!, {instr, reg, stack, r7, r8, pc}) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | |
| 150 | .Lfp: .asciz " r%d = %08X%c" |
| 151 | .Lcr: .asciz "\n" |
| 152 | .Lbad: .asciz "Backtrace aborted due to bad frame pointer <%p>\n" |
| 153 | .align |
| 154 | .Ldsi: .word 0x00e92dd8 >> 2 |
| 155 | .word 0x00e92d00 >> 2 |
| 156 | |
| 157 | #endif |