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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 | */ | |
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 | ||
32 | #ifndef CONFIG_FRAME_POINTER | |
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 | ||
125 | .Ldumpstm: stmfd sp!, {instr, reg, stack, r7, lr} | |
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 | |
148 | LOADREGS(fd, sp!, {instr, reg, stack, r7, pc}) | |
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 |