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
16 static 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
24 static void backtrace_test_bh_workfn(struct work_struct *work)
25 {
26 dump_stack();
27 }
28
29 static DECLARE_WORK(backtrace_bh_work, &backtrace_test_bh_workfn);
30
31 static 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
41 static 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
53 static void backtrace_test_saved(void)
54 {
55 pr_info("Saved backtrace test skipped.\n");
56 }
57 #endif
58
59 static 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
71 static void exitf(void)
72 {
73 }
74
75 module_init(backtrace_regression_test);
76 module_exit(exitf);
77 MODULE_DESCRIPTION("Simple stack backtrace regression test module");
78 MODULE_LICENSE("GPL");
79 MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");
80
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