| 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(wq: system_bh_wq, work: &backtrace_bh_work); |
| 37 | flush_work(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(store: entries, ARRAY_SIZE(entries), skipnr: 0); |
| 50 | stack_trace_print(trace: entries, nr_entries, spaces: 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 |