Commit | Line | Data |
---|---|---|
2f026037 HS |
1 | /* |
2 | * Stack trace management functions | |
3 | * | |
4 | * Copyright (C) 2007 Atmel Corporation | |
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 | #include <linux/sched.h> | |
11 | #include <linux/stacktrace.h> | |
12 | #include <linux/thread_info.h> | |
13 | ||
14 | register unsigned long current_frame_pointer asm("r7"); | |
15 | ||
16 | struct stackframe { | |
17 | unsigned long lr; | |
18 | unsigned long fp; | |
19 | }; | |
20 | ||
21 | /* | |
22 | * Save stack-backtrace addresses into a stack_trace buffer. | |
23 | */ | |
24 | void save_stack_trace(struct stack_trace *trace) | |
25 | { | |
26 | unsigned long low, high; | |
27 | unsigned long fp; | |
28 | struct stackframe *frame; | |
29 | int skip = trace->skip; | |
30 | ||
31 | low = (unsigned long)task_stack_page(current); | |
32 | high = low + THREAD_SIZE; | |
33 | fp = current_frame_pointer; | |
34 | ||
35 | while (fp >= low && fp <= (high - 8)) { | |
36 | frame = (struct stackframe *)fp; | |
37 | ||
38 | if (skip) { | |
39 | skip--; | |
40 | } else { | |
41 | trace->entries[trace->nr_entries++] = frame->lr; | |
42 | if (trace->nr_entries >= trace->max_entries) | |
43 | break; | |
44 | } | |
45 | ||
46 | /* | |
47 | * The next frame must be at a higher address than the | |
48 | * current frame. | |
49 | */ | |
50 | low = fp + 8; | |
51 | fp = frame->fp; | |
52 | } | |
53 | } |