kernel/backtracetest.c

   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 DECLARE_COMPLETION(backtrace_work);
  25
  26 static void backtrace_test_irq_callback(unsigned long data)
  27 {
  28         dump_stack();
  29         complete(&backtrace_work);
  30 }
  31
  32 static DECLARE_TASKLET(backtrace_tasklet, &backtrace_test_irq_callback, 0);
  33
  34 static void backtrace_test_irq(void)
  35 {
  36         pr_info("Testing a backtrace from irq context.\n");
  37         pr_info("The following trace is a kernel self test and not a bug!\n");
  38
  39         init_completion(&backtrace_work);
  40         tasklet_schedule(&backtrace_tasklet);
  41         wait_for_completion(&backtrace_work);
  42 }
  43
  44 #ifdef CONFIG_STACKTRACE
  45 static void backtrace_test_saved(void)
  46 {
  47         unsigned long entries[8];
  48         unsigned int nr_entries;
  49
  50         pr_info("Testing a saved backtrace.\n");
  51         pr_info("The following trace is a kernel self test and not a bug!\n");
  52
  53         nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0);
  54         stack_trace_print(entries, nr_entries, 0);
  55 }
  56 #else
  57 static void backtrace_test_saved(void)
  58 {
  59         pr_info("Saved backtrace test skipped.\n");
  60 }
  61 #endif
  62
  63 static int backtrace_regression_test(void)
  64 {
  65         pr_info("====[ backtrace testing ]===========\n");
  66
  67         backtrace_test_normal();
  68         backtrace_test_irq();
  69         backtrace_test_saved();
  70
  71         pr_info("====[ end of backtrace testing ]====\n");
  72         return 0;
  73 }
  74
  75 static void exitf(void)
  76 {
  77 }
  78
  79 module_init(backtrace_regression_test);
  80 module_exit(exitf);
  81 MODULE_LICENSE("GPL");
  82 MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");