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 void backtrace_test_bh_workfn(struct work_struct *work) 25 { 26 dump_stack(); 27 } 28 29 static DECLARE_WORK(backtrace_bh_work, &backtrace_test_bh_workfn); 30 31 static void backtrace_test_bh(void) 32 { 33 pr_info("Testing a backtrace from BH context.\n"); 34 pr_info("The following trace is a kernel self test and not a bug!\n"); 35 36 queue_work(system_bh_wq, &backtrace_bh_work); 37 flush_work(&backtrace_bh_work); 38 } 39 40 #ifdef CONFIG_STACKTRACE 41 static void backtrace_test_saved(void) 42 { 43 unsigned long entries[8]; 44 unsigned int nr_entries; 45 46 pr_info("Testing a saved backtrace.\n"); 47 pr_info("The following trace is a kernel self test and not a bug!\n"); 48 49 nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0); 50 stack_trace_print(entries, nr_entries, 0); 51 } 52 #else 53 static void backtrace_test_saved(void) 54 { 55 pr_info("Saved backtrace test skipped.\n"); 56 } 57 #endif 58 59 static int backtrace_regression_test(void) 60 { 61 pr_info("====[ backtrace testing ]===========\n"); 62 63 backtrace_test_normal(); 64 backtrace_test_bh(); 65 backtrace_test_saved(); 66 67 pr_info("====[ end of backtrace testing ]====\n"); 68 return 0; 69 } 70 71 static void exitf(void) 72 { 73 } 74 75 module_init(backtrace_regression_test); 76 module_exit(exitf); 77 MODULE_LICENSE("GPL"); 78 MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>"); 79