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f16fb1ec RK |
1 | #include <linux/sched.h> |
2 | #include <linux/stacktrace.h> | |
3 | ||
4 | #include "stacktrace.h" | |
5 | ||
6 | int walk_stackframe(unsigned long fp, unsigned long low, unsigned long high, | |
7 | int (*fn)(struct stackframe *, void *), void *data) | |
8 | { | |
9 | struct stackframe *frame; | |
10 | ||
11 | do { | |
12 | /* | |
13 | * Check current frame pointer is within bounds | |
14 | */ | |
15 | if ((fp - 12) < low || fp + 4 >= high) | |
16 | break; | |
17 | ||
18 | frame = (struct stackframe *)(fp - 12); | |
19 | ||
20 | if (fn(frame, data)) | |
21 | break; | |
22 | ||
23 | /* | |
24 | * Update the low bound - the next frame must always | |
25 | * be at a higher address than the current frame. | |
26 | */ | |
27 | low = fp + 4; | |
28 | fp = frame->fp; | |
29 | } while (fp); | |
30 | ||
31 | return 0; | |
32 | } | |
33 | ||
34 | #ifdef CONFIG_STACKTRACE | |
35 | struct stack_trace_data { | |
36 | struct stack_trace *trace; | |
37 | unsigned int skip; | |
38 | }; | |
39 | ||
40 | static int save_trace(struct stackframe *frame, void *d) | |
41 | { | |
42 | struct stack_trace_data *data = d; | |
43 | struct stack_trace *trace = data->trace; | |
44 | ||
45 | if (data->skip) { | |
46 | data->skip--; | |
47 | return 0; | |
48 | } | |
49 | ||
50 | trace->entries[trace->nr_entries++] = frame->lr; | |
51 | ||
52 | return trace->nr_entries >= trace->max_entries; | |
53 | } | |
54 | ||
55 | void save_stack_trace(struct stack_trace *trace, struct task_struct *task) | |
56 | { | |
57 | struct stack_trace_data data; | |
58 | unsigned long fp, base; | |
59 | ||
60 | data.trace = trace; | |
61 | data.skip = trace->skip; | |
62 | ||
63 | if (task) { | |
64 | base = (unsigned long)task_stack_page(task); | |
65 | fp = 0; /* FIXME */ | |
66 | } else { | |
67 | base = (unsigned long)task_stack_page(current); | |
68 | asm("mov %0, fp" : "=r" (fp)); | |
69 | } | |
70 | ||
71 | walk_stackframe(fp, base, base + THREAD_SIZE, save_trace, &data); | |
72 | } | |
73 | #endif |