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
15register unsigned long current_frame_pointer asm("r7");
16
17struct stackframe {
18	unsigned long lr;
19	unsigned long fp;
20};
21
22/*
23 * Save stack-backtrace addresses into a stack_trace buffer.
24 */
25void 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}
55EXPORT_SYMBOL_GPL(save_stack_trace);

 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
15register unsigned long current_frame_pointer asm("r7");
16
17struct stackframe {
18	unsigned long lr;
19	unsigned long fp;
20};
21
22/*
23 * Save stack-backtrace addresses into a stack_trace buffer.
24 */
25void 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}
55EXPORT_SYMBOL_GPL(save_stack_trace);