summaryrefslogtreecommitdiffstats
path: root/arch/avr32/kernel/stacktrace.c
blob: 9a68190bbffd78dd41703259c3012c3d638b6994 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
/*
 * Stack trace management functions
 *
 * Copyright (C) 2007 Atmel Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/sched.h>
#include <linux/stacktrace.h>
#include <linux/thread_info.h>

register unsigned long current_frame_pointer asm("r7");

struct stackframe {
	unsigned long lr;
	unsigned long fp;
};

/*
 * Save stack-backtrace addresses into a stack_trace buffer.
 */
void save_stack_trace(struct stack_trace *trace)
{
	unsigned long low, high;
	unsigned long fp;
	struct stackframe *frame;
	int skip = trace->skip;

	low = (unsigned long)task_stack_page(current);
	high = low + THREAD_SIZE;
	fp = current_frame_pointer;

	while (fp >= low && fp <= (high - 8)) {
		frame = (struct stackframe *)fp;

		if (skip) {
			skip--;
		} else {
			trace->entries[trace->nr_entries++] = frame->lr;
			if (trace->nr_entries >= trace->max_entries)
				break;
		}

		/*
		 * The next frame must be at a higher address than the
		 * current frame.
		 */
		low = fp + 8;
		fp = frame->fp;
	}
}