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 <linux/completion.h> 12 #include <linux/kernel.h> 13 #include <linux/kthread.h> 14 15 #include "try-catch-impl.h" 16 17 void __noreturn kunit_try_catch_throw(struct kunit_try_catch *try_catch) 18 { 19 try_catch->try_result = -EFAULT; 20 kthread_complete_and_exit(try_catch->try_completion, -EFAULT); 21 } 22 EXPORT_SYMBOL_GPL(kunit_try_catch_throw); 23 24 static int kunit_generic_run_threadfn_adapter(void *data) 25 { 26 struct kunit_try_catch *try_catch = data; 27 28 try_catch->try(try_catch->context); 29 30 kthread_complete_and_exit(try_catch->try_completion, 0); 31 } 32 33 static unsigned long kunit_test_timeout(void) 34 { 35 /* 36 * TODO(brendanhiggins@google.com): We should probably have some type of 37 * variable timeout here. The only question is what that timeout value 38 * should be. 39 * 40 * The intention has always been, at some point, to be able to label 41 * tests with some type of size bucket (unit/small, integration/medium, 42 * large/system/end-to-end, etc), where each size bucket would get a 43 * default timeout value kind of like what Bazel does: 44 * https://docs.bazel.build/versions/master/be/common-definitions.html#test.size 45 * There is still some debate to be had on exactly how we do this. (For 46 * one, we probably want to have some sort of test runner level 47 * timeout.) 48 * 49 * For more background on this topic, see: 50 * https://mike-bland.com/2011/11/01/small-medium-large.html 51 * 52 * If tests timeout due to exceeding sysctl_hung_task_timeout_secs, 53 * the task will be killed and an oops generated. 54 */ 55 return 300 * MSEC_PER_SEC; /* 5 min */ 56 } 57 58 void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context) 59 { 60 DECLARE_COMPLETION_ONSTACK(try_completion); 61 struct kunit *test = try_catch->test; 62 struct task_struct *task_struct; 63 int exit_code, time_remaining; 64 65 try_catch->context = context; 66 try_catch->try_completion = &try_completion; 67 try_catch->try_result = 0; 68 task_struct = kthread_run(kunit_generic_run_threadfn_adapter, 69 try_catch, 70 "kunit_try_catch_thread"); 71 if (IS_ERR(task_struct)) { 72 try_catch->catch(try_catch->context); 73 return; 74 } 75 76 time_remaining = wait_for_completion_timeout(&try_completion, 77 kunit_test_timeout()); 78 if (time_remaining == 0) { 79 kunit_err(test, "try timed out\n"); 80 try_catch->try_result = -ETIMEDOUT; 81 } 82 83 exit_code = try_catch->try_result; 84 85 if (!exit_code) 86 return; 87 88 if (exit_code == -EFAULT) 89 try_catch->try_result = 0; 90 else if (exit_code == -EINTR) 91 kunit_err(test, "wake_up_process() was never called\n"); 92 else if (exit_code) 93 kunit_err(test, "Unknown error: %d\n", exit_code); 94 95 try_catch->catch(try_catch->context); 96 } 97 EXPORT_SYMBOL_GPL(kunit_try_catch_run); 98