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 16 static 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 24 static DECLARE_COMPLETION(backtrace_work); 25 26 static void backtrace_test_irq_callback(unsigned long data) 27 { 28 dump_stack(); 29 complete(&backtrace_work); 30 } 31 32 static DECLARE_TASKLET(backtrace_tasklet, &backtrace_test_irq_callback, 0); 33 34 static 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 45 static 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 57 static void backtrace_test_saved(void) 58 { 59 pr_info("Saved backtrace test skipped.\n"); 60 } 61 #endif 62 63 static 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 75 static void exitf(void) 76 { 77 } 78 79 module_init(backtrace_regression_test); 80 module_exit(exitf); 81 MODULE_LICENSE("GPL"); 82 MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>"); 83