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/delay.h>
  14 #include <linux/module.h>
  15 #include <linux/sched.h>
  16 #include <linux/stacktrace.h>
  17
  18 static struct timer_list backtrace_timer;
  19
  20 static void backtrace_test_timer(unsigned long data)
  21 {
  22         printk("Testing a backtrace from irq context.\n");
  23         printk("The following trace is a kernel self test and not a bug!\n");
  24         dump_stack();
  25 }
  26
  27 #ifdef CONFIG_STACKTRACE
  28 static void backtrace_test_saved(void)
  29 {
  30         struct stack_trace trace;
  31         unsigned long entries[8];
  32
  33         printk("Testing a saved backtrace.\n");
  34         printk("The following trace is a kernel self test and not a bug!\n");
  35
  36         trace.nr_entries = 0;
  37         trace.max_entries = ARRAY_SIZE(entries);
  38         trace.entries = entries;
  39         trace.skip = 0;
  40
  41         save_stack_trace(&trace);
  42         print_stack_trace(&trace, 0);
  43 }
  44 #else
  45 static void backtrace_test_saved(void)
  46 {
  47         printk("Saved backtrace test skipped.\n");
  48 }
  49 #endif
  50
  51 static int backtrace_regression_test(void)
  52 {
  53         printk("====[ backtrace testing ]===========\n");
  54         printk("Testing a backtrace from process context.\n");
  55         printk("The following trace is a kernel self test and not a bug!\n");
  56         dump_stack();
  57
  58         backtrace_test_saved();
  59
  60         init_timer(&backtrace_timer);
  61         backtrace_timer.function = backtrace_test_timer;
  62         mod_timer(&backtrace_timer, jiffies + 10);
  63
  64         msleep(10);
  65         printk("====[ end of backtrace testing ]====\n");
  66         return 0;
  67 }
  68
  69 static void exitf(void)
  70 {
  71 }
  72
  73 module_init(backtrace_regression_test);
  74 module_exit(exitf);
  75 MODULE_LICENSE("GPL");
  76 MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");