1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * An API to allow a function, that may fail, to be executed, and recover in a 4 * controlled manner. 5 * 6 * Copyright (C) 2019, Google LLC. 7 * Author: Brendan Higgins <brendanhiggins@google.com> 8 */ 9 10 #include <kunit/test.h> 11 #include <kunit/try-catch.h> 12 #include <linux/completion.h> 13 #include <linux/kernel.h> 14 #include <linux/kthread.h> 15 #include <linux/sched/sysctl.h> 16 17 void __noreturn kunit_try_catch_throw(struct kunit_try_catch *try_catch) 18 { 19 try_catch->try_result = -EFAULT; 20 complete_and_exit(try_catch->try_completion, -EFAULT); 21 } 22 23 static int kunit_generic_run_threadfn_adapter(void *data) 24 { 25 struct kunit_try_catch *try_catch = data; 26 27 try_catch->try(try_catch->context); 28 29 complete_and_exit(try_catch->try_completion, 0); 30 } 31 32 static unsigned long kunit_test_timeout(void) 33 { 34 unsigned long timeout_msecs; 35 36 /* 37 * TODO(brendanhiggins@google.com): We should probably have some type of 38 * variable timeout here. The only question is what that timeout value 39 * should be. 40 * 41 * The intention has always been, at some point, to be able to label 42 * tests with some type of size bucket (unit/small, integration/medium, 43 * large/system/end-to-end, etc), where each size bucket would get a 44 * default timeout value kind of like what Bazel does: 45 * https://docs.bazel.build/versions/master/be/common-definitions.html#test.size 46 * There is still some debate to be had on exactly how we do this. (For 47 * one, we probably want to have some sort of test runner level 48 * timeout.) 49 * 50 * For more background on this topic, see: 51 * https://mike-bland.com/2011/11/01/small-medium-large.html 52 */ 53 if (sysctl_hung_task_timeout_secs) { 54 /* 55 * If sysctl_hung_task is active, just set the timeout to some 56 * value less than that. 57 * 58 * In regards to the above TODO, if we decide on variable 59 * timeouts, this logic will likely need to change. 60 */ 61 timeout_msecs = (sysctl_hung_task_timeout_secs - 1) * 62 MSEC_PER_SEC; 63 } else { 64 timeout_msecs = 300 * MSEC_PER_SEC; /* 5 min */ 65 } 66 67 return timeout_msecs; 68 } 69 70 void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context) 71 { 72 DECLARE_COMPLETION_ONSTACK(try_completion); 73 struct kunit *test = try_catch->test; 74 struct task_struct *task_struct; 75 int exit_code, time_remaining; 76 77 try_catch->context = context; 78 try_catch->try_completion = &try_completion; 79 try_catch->try_result = 0; 80 task_struct = kthread_run(kunit_generic_run_threadfn_adapter, 81 try_catch, 82 "kunit_try_catch_thread"); 83 if (IS_ERR(task_struct)) { 84 try_catch->catch(try_catch->context); 85 return; 86 } 87 88 time_remaining = wait_for_completion_timeout(&try_completion, 89 kunit_test_timeout()); 90 if (time_remaining == 0) { 91 kunit_err(test, "try timed out\n"); 92 try_catch->try_result = -ETIMEDOUT; 93 } 94 95 exit_code = try_catch->try_result; 96 97 if (!exit_code) 98 return; 99 100 if (exit_code == -EFAULT) 101 try_catch->try_result = 0; 102 else if (exit_code == -EINTR) 103 kunit_err(test, "wake_up_process() was never called\n"); 104 else if (exit_code) 105 kunit_err(test, "Unknown error: %d\n", exit_code); 106 107 try_catch->catch(try_catch->context); 108 } 109 110 void kunit_try_catch_init(struct kunit_try_catch *try_catch, 111 struct kunit *test, 112 kunit_try_catch_func_t try, 113 kunit_try_catch_func_t catch) 114 { 115 try_catch->test = test; 116 try_catch->try = try; 117 try_catch->catch = catch; 118 } 119