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1da177e4 LT |
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 | */ | |
1da177e4 LT |
13 | #include <linux/linkage.h> |
14 | #include <asm/assembler.h> | |
15 | .text | |
16 | ||
17 | @ fp is 0 or stack frame | |
18 | ||
19 | #define frame r4 | |
20 | #define next r5 | |
21 | #define save r6 | |
22 | #define mask r7 | |
23 | #define offset r8 | |
24 | ||
25 | ENTRY(__backtrace) | |
26 | mov r1, #0x10 | |
27 | mov r0, fp | |
28 | ||
29 | ENTRY(c_backtrace) | |
30 | ||
3ee357f0 | 31 | #if !defined(CONFIG_FRAME_POINTER) || !defined(CONFIG_PRINTK) |
1da177e4 LT |
32 | mov pc, lr |
33 | #else | |
34 | ||
35 | stmfd sp!, {r4 - r8, lr} @ Save an extra register so we have a location... | |
36 | tst r1, #0x10 @ 26 or 32-bit? | |
37 | moveq mask, #0xfc000003 | |
38 | movne mask, #0 | |
39 | tst mask, r0 | |
40 | movne r0, #0 | |
41 | movs frame, r0 | |
42 | 1: moveq r0, #-2 | |
1b93a717 | 43 | ldmeqfd sp!, {r4 - r8, pc} |
1da177e4 LT |
44 | |
45 | 2: stmfd sp!, {pc} @ calculate offset of PC in STMIA instruction | |
46 | ldr r0, [sp], #4 | |
47 | adr r1, 2b - 4 | |
48 | sub offset, r0, r1 | |
49 | ||
50 | 3: tst frame, mask @ Check for address exceptions... | |
51 | bne 1b | |
52 | ||
53 | 1001: ldr next, [frame, #-12] @ get fp | |
54 | 1002: ldr r2, [frame, #-4] @ get lr | |
55 | 1003: ldr r3, [frame, #0] @ get pc | |
56 | sub save, r3, offset @ Correct PC for prefetching | |
57 | bic save, save, mask | |
58 | 1004: ldr r1, [save, #0] @ get instruction at function | |
59 | mov r1, r1, lsr #10 | |
60 | ldr r3, .Ldsi+4 | |
61 | teq r1, r3 | |
62 | subeq save, save, #4 | |
63 | mov r0, save | |
64 | bic r1, r2, mask | |
65 | bl dump_backtrace_entry | |
66 | ||
67 | ldr r0, [frame, #-8] @ get sp | |
68 | sub r0, r0, #4 | |
69 | 1005: ldr r1, [save, #4] @ get instruction at function+4 | |
70 | mov r3, r1, lsr #10 | |
71 | ldr r2, .Ldsi+4 | |
72 | teq r3, r2 @ Check for stmia sp!, {args} | |
73 | addeq save, save, #4 @ next instruction | |
74 | bleq .Ldumpstm | |
75 | ||
76 | sub r0, frame, #16 | |
77 | 1006: ldr r1, [save, #4] @ Get 'stmia sp!, {rlist, fp, ip, lr, pc}' instruction | |
78 | mov r3, r1, lsr #10 | |
79 | ldr r2, .Ldsi | |
80 | teq r3, r2 | |
81 | bleq .Ldumpstm | |
82 | ||
83 | /* | |
84 | * A zero next framepointer means we're done. | |
85 | */ | |
86 | teq next, #0 | |
1b93a717 | 87 | ldmeqfd sp!, {r4 - r8, pc} |
1da177e4 LT |
88 | |
89 | /* | |
90 | * The next framepointer must be above the | |
91 | * current framepointer. | |
92 | */ | |
93 | cmp next, frame | |
94 | mov frame, next | |
95 | bhi 3b | |
96 | b 1007f | |
97 | ||
98 | /* | |
583e7f5d | 99 | * Fixup for LDMDB. Note that this must not be in the fixup section. |
1da177e4 | 100 | */ |
1da177e4 LT |
101 | 1007: ldr r0, =.Lbad |
102 | mov r1, frame | |
103 | bl printk | |
1b93a717 | 104 | ldmfd sp!, {r4 - r8, pc} |
1da177e4 | 105 | .ltorg |
1da177e4 LT |
106 | |
107 | .section __ex_table,"a" | |
108 | .align 3 | |
109 | .long 1001b, 1007b | |
110 | .long 1002b, 1007b | |
111 | .long 1003b, 1007b | |
112 | .long 1004b, 1007b | |
113 | .long 1005b, 1007b | |
114 | .long 1006b, 1007b | |
115 | .previous | |
116 | ||
117 | #define instr r4 | |
118 | #define reg r5 | |
119 | #define stack r6 | |
120 | ||
1d6760a3 | 121 | .Ldumpstm: stmfd sp!, {instr, reg, stack, r7, r8, lr} |
1da177e4 LT |
122 | mov stack, r0 |
123 | mov instr, r1 | |
124 | mov reg, #9 | |
125 | mov r7, #0 | |
126 | 1: mov r3, #1 | |
127 | tst instr, r3, lsl reg | |
128 | beq 2f | |
129 | add r7, r7, #1 | |
130 | teq r7, #4 | |
131 | moveq r7, #0 | |
132 | moveq r3, #'\n' | |
133 | movne r3, #' ' | |
134 | ldr r2, [stack], #-4 | |
135 | mov r1, reg | |
136 | adr r0, .Lfp | |
137 | bl printk | |
138 | 2: subs reg, reg, #1 | |
139 | bpl 1b | |
140 | teq r7, #0 | |
141 | adrne r0, .Lcr | |
142 | blne printk | |
143 | mov r0, stack | |
1b93a717 | 144 | ldmfd sp!, {instr, reg, stack, r7, r8, pc} |
1da177e4 LT |
145 | |
146 | .Lfp: .asciz " r%d = %08X%c" | |
147 | .Lcr: .asciz "\n" | |
148 | .Lbad: .asciz "Backtrace aborted due to bad frame pointer <%p>\n" | |
149 | .align | |
150 | .Ldsi: .word 0x00e92dd8 >> 2 | |
151 | .word 0x00e92d00 >> 2 | |
152 | ||
153 | #endif |