1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Simple stack backtrace regression test module
4 *
5 * (C) Copyright 2008 Intel Corporation
6 * Author: Arjan van de Ven <arjan@linux.intel.com>
7 */
8
9#include <linux/completion.h>
10#include <linux/delay.h>
11#include <linux/interrupt.h>
12#include <linux/module.h>
13#include <linux/sched.h>
14#include <linux/stacktrace.h>
15
16static void backtrace_test_normal(void)
17{
18	pr_info("Testing a backtrace from process context.\n");
19	pr_info("The following trace is a kernel self test and not a bug!\n");
20
21	dump_stack();
22}
23
24static void backtrace_test_bh_workfn(struct work_struct *work)
25{
26	dump_stack();
27}
28
29static DECLARE_WORK(backtrace_bh_work, &backtrace_test_bh_workfn);
30
31static void backtrace_test_bh(void)
32{
33	pr_info("Testing a backtrace from BH context.\n");
34	pr_info("The following trace is a kernel self test and not a bug!\n");
35
36	queue_work(system_bh_wq, &backtrace_bh_work);
37	flush_work(&backtrace_bh_work);
38}
39
40#ifdef CONFIG_STACKTRACE
41static void backtrace_test_saved(void)
42{
43	unsigned long entries[8];
44	unsigned int nr_entries;
45
46	pr_info("Testing a saved backtrace.\n");
47	pr_info("The following trace is a kernel self test and not a bug!\n");
48
49	nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0);
50	stack_trace_print(entries, nr_entries, 0);
51}
52#else
53static void backtrace_test_saved(void)
54{
55	pr_info("Saved backtrace test skipped.\n");
56}
57#endif
58
59static int backtrace_regression_test(void)
60{
61	pr_info("====[ backtrace testing ]===========\n");
62
63	backtrace_test_normal();
64	backtrace_test_bh();
65	backtrace_test_saved();
66
67	pr_info("====[ end of backtrace testing ]====\n");
68	return 0;
69}
70
71static void exitf(void)
72{
73}
74
75module_init(backtrace_regression_test);
76module_exit(exitf);
77MODULE_LICENSE("GPL");
78MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");
79