LXR linux/kernel/backtracetest.c

   1/*
   2 * Simple stack backtrace regression test module
   3 *
   4 * (C) Copyright 2008 Intel Corporation
   5 * Author: Arjan van de Ven <arjan@linux.intel.com>
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public License
   9 * as published by the Free Software Foundation; version 2
  10 * of the License.
  11 */
  12
  13#include <linux/completion.h>
  14#include <linux/delay.h>
  15#include <linux/interrupt.h>
  16#include <linux/module.h>
  17#include <linux/sched.h>
  18#include <linux/stacktrace.h>
  19
  20static void backtrace_test_normal(void)
  21{
  22        pr_info("Testing a backtrace from process context.\n");
  23        pr_info("The following trace is a kernel self test and not a bug!\n");
  24
  25        dump_stack();
  26}
  27
  28static DECLARE_COMPLETION(backtrace_work);
  29
  30static void backtrace_test_irq_callback(unsigned long data)
  31{
  32        dump_stack();
  33        complete(&backtrace_work);
  34}
  35
  36static DECLARE_TASKLET(backtrace_tasklet, &backtrace_test_irq_callback, 0);
  37
  38static void backtrace_test_irq(void)
  39{
  40        pr_info("Testing a backtrace from irq context.\n");
  41        pr_info("The following trace is a kernel self test and not a bug!\n");
  42
  43        init_completion(&backtrace_work);
  44        tasklet_schedule(&backtrace_tasklet);
  45        wait_for_completion(&backtrace_work);
  46}
  47
  48#ifdef CONFIG_STACKTRACE
  49static void backtrace_test_saved(void)
  50{
  51        struct stack_trace trace;
  52        unsigned long entries[8];
  53
  54        pr_info("Testing a saved backtrace.\n");
  55        pr_info("The following trace is a kernel self test and not a bug!\n");
  56
  57        trace.nr_entries = 0;
  58        trace.max_entries = ARRAY_SIZE(entries);
  59        trace.entries = entries;
  60        trace.skip = 0;
  61
  62        save_stack_trace(&trace);
  63        print_stack_trace(&trace, 0);
  64}
  65#else
  66static void backtrace_test_saved(void)
  67{
  68        pr_info("Saved backtrace test skipped.\n");
  69}
  70#endif
  71
  72static int backtrace_regression_test(void)
  73{
  74        pr_info("====[ backtrace testing ]===========\n");
  75
  76        backtrace_test_normal();
  77        backtrace_test_irq();
  78        backtrace_test_saved();
  79
  80        pr_info("====[ end of backtrace testing ]====\n");
  81        return 0;
  82}
  83
  84static void exitf(void)
  85{
  86}
  87
  88module_init(backtrace_regression_test);
  89module_exit(exitf);
  90MODULE_LICENSE("GPL");
  91MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");
  92