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 20 static 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 28 static DECLARE_COMPLETION(backtrace_work); 29 30 static void backtrace_test_irq_callback(unsigned long data) 31 { 32 dump_stack(); 33 complete(&backtrace_work); 34 } 35 36 static DECLARE_TASKLET(backtrace_tasklet, &backtrace_test_irq_callback, 0); 37 38 static 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 49 static 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 66 static void backtrace_test_saved(void) 67 { 68 pr_info("Saved backtrace test skipped.\n"); 69 } 70 #endif 71 72 static 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 84 static void exitf(void) 85 { 86 } 87 88 module_init(backtrace_regression_test); 89 module_exit(exitf); 90 MODULE_LICENSE("GPL"); 91 MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>"); 92