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 unsigned long entries[8]; 52 unsigned int nr_entries; 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 nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0); 58 stack_trace_print(entries, nr_entries, 0); 59 } 60 #else 61 static void backtrace_test_saved(void) 62 { 63 pr_info("Saved backtrace test skipped.\n"); 64 } 65 #endif 66 67 static int backtrace_regression_test(void) 68 { 69 pr_info("====[ backtrace testing ]===========\n"); 70 71 backtrace_test_normal(); 72 backtrace_test_irq(); 73 backtrace_test_saved(); 74 75 pr_info("====[ end of backtrace testing ]====\n"); 76 return 0; 77 } 78 79 static void exitf(void) 80 { 81 } 82 83 module_init(backtrace_regression_test); 84 module_exit(exitf); 85 MODULE_LICENSE("GPL"); 86 MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>"); 87