Merge branches 'release' and 'gpe-ack' into release
[linux-2.6] / arch / avr32 / kernel / stacktrace.c
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 }