LXR linux/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
  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 DECLARE_COMPLETION(backtrace_work);
  25
  26static void backtrace_test_irq_callback(unsigned long data)
  27{
  28        dump_stack();
  29        complete(&backtrace_work);
  30}
  31
  32static DECLARE_TASKLET(backtrace_tasklet, &backtrace_test_irq_callback, 0);
  33
  34static 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
  45static 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
  57static void backtrace_test_saved(void)
  58{
  59        pr_info("Saved backtrace test skipped.\n");
  60}
  61#endif
  62
  63static 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
  75static void exitf(void)
  76{
  77}
  78
  79module_init(backtrace_regression_test);
  80module_exit(exitf);
  81MODULE_LICENSE("GPL");
  82MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");
  83