1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Stacktrace support for Hexagon
4 *
5 * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
6 */
7
8#include <linux/sched.h>
9#include <linux/sched/task_stack.h>
10#include <linux/stacktrace.h>
11#include <linux/thread_info.h>
12#include <linux/module.h>
13
14struct stackframe {
15	unsigned long fp;
16	unsigned long rets;
17};
18
19/*
20 * Save stack-backtrace addresses into a stack_trace buffer.
21 */
22void save_stack_trace(struct stack_trace *trace)
23{
24	unsigned long low, high;
25	unsigned long fp;
26	struct stackframe *frame;
27	int skip = trace->skip;
28
29	low = (unsigned long)task_stack_page(current);
30	high = low + THREAD_SIZE;
31	fp = (unsigned long)__builtin_frame_address(0);
32
33	while (fp >= low && fp <= (high - sizeof(*frame))) {
34		frame = (struct stackframe *)fp;
35
36		if (skip) {
37			skip--;
38		} else {
39			trace->entries[trace->nr_entries++] = frame->rets;
40			if (trace->nr_entries >= trace->max_entries)
41				break;
42		}
43
44		/*
45		 * The next frame must be at a higher address than the
46		 * current frame.
47		 */
48		low = fp + sizeof(*frame);
49		fp = frame->fp;
50	}
51}
52EXPORT_SYMBOL_GPL(save_stack_trace);
53