Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
[linux-2.6.git] / 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 #include <linux/module.h>
14
15 register unsigned long current_frame_pointer asm("r7");
16
17 struct stackframe {
18         unsigned long lr;
19         unsigned long fp;
20 };
21
22 /*
23  * Save stack-backtrace addresses into a stack_trace buffer.
24  */
25 void save_stack_trace(struct stack_trace *trace)
26 {
27         unsigned long low, high;
28         unsigned long fp;
29         struct stackframe *frame;
30         int skip = trace->skip;
31
32         low = (unsigned long)task_stack_page(current);
33         high = low + THREAD_SIZE;
34         fp = current_frame_pointer;
35
36         while (fp >= low && fp <= (high - 8)) {
37                 frame = (struct stackframe *)fp;
38
39                 if (skip) {
40                         skip--;
41                 } else {
42                         trace->entries[trace->nr_entries++] = frame->lr;
43                         if (trace->nr_entries >= trace->max_entries)
44                                 break;
45                 }
46
47                 /*
48                  * The next frame must be at a higher address than the
49                  * current frame.
50                  */
51                 low = fp + 8;
52                 fp = frame->fp;
53         }
54 }
55 EXPORT_SYMBOL_GPL(save_stack_trace);