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1// SPDX-License-Identifier: GPL-2.02/*3 * An API to allow a function, that may fail, to be executed, and recover in a4 * 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#include <linux/sched/task.h>15 16#include "try-catch-impl.h"17 18void __noreturn kunit_try_catch_throw(struct kunit_try_catch *try_catch)19{20 try_catch->try_result = -EFAULT;21 kthread_exit(0);22}23EXPORT_SYMBOL_GPL(kunit_try_catch_throw);24 25static int kunit_generic_run_threadfn_adapter(void *data)26{27 struct kunit_try_catch *try_catch = data;28 29 try_catch->try_result = -EINTR;30 try_catch->try(try_catch->context);31 if (try_catch->try_result == -EINTR)32 try_catch->try_result = 0;33 34 return 0;35}36 37static unsigned long kunit_test_timeout(void)38{39 /*40 * TODO(brendanhiggins@google.com): We should probably have some type of41 * variable timeout here. The only question is what that timeout value42 * should be.43 *44 * The intention has always been, at some point, to be able to label45 * tests with some type of size bucket (unit/small, integration/medium,46 * large/system/end-to-end, etc), where each size bucket would get a47 * default timeout value kind of like what Bazel does:48 * https://docs.bazel.build/versions/master/be/common-definitions.html#test.size49 * There is still some debate to be had on exactly how we do this. (For50 * one, we probably want to have some sort of test runner level51 * timeout.)52 *53 * For more background on this topic, see:54 * https://mike-bland.com/2011/11/01/small-medium-large.html55 *56 * If tests timeout due to exceeding sysctl_hung_task_timeout_secs,57 * the task will be killed and an oops generated.58 */59 return 300 * msecs_to_jiffies(MSEC_PER_SEC); /* 5 min */60}61 62void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context)63{64 struct kunit *test = try_catch->test;65 struct task_struct *task_struct;66 struct completion *task_done;67 int exit_code, time_remaining;68 69 try_catch->context = context;70 try_catch->try_result = 0;71 task_struct = kthread_create(kunit_generic_run_threadfn_adapter,72 try_catch, "kunit_try_catch_thread");73 if (IS_ERR(task_struct)) {74 try_catch->try_result = PTR_ERR(task_struct);75 try_catch->catch(try_catch->context);76 return;77 }78 get_task_struct(task_struct);79 /*80 * As for a vfork(2), task_struct->vfork_done (pointing to the81 * underlying kthread->exited) can be used to wait for the end of a82 * kernel thread. It is set to NULL when the thread exits, so we83 * keep a copy here.84 */85 task_done = task_struct->vfork_done;86 wake_up_process(task_struct);87 88 time_remaining = wait_for_completion_timeout(task_done,89 kunit_test_timeout());90 if (time_remaining == 0) {91 try_catch->try_result = -ETIMEDOUT;92 kthread_stop(task_struct);93 }94 95 put_task_struct(task_struct);96 exit_code = try_catch->try_result;97 98 if (!exit_code)99 return;100 101 if (exit_code == -EFAULT)102 try_catch->try_result = 0;103 else if (exit_code == -EINTR) {104 if (test->last_seen.file)105 kunit_err(test, "try faulted: last line seen %s:%d\n",106 test->last_seen.file, test->last_seen.line);107 else108 kunit_err(test, "try faulted\n");109 } else if (exit_code == -ETIMEDOUT)110 kunit_err(test, "try timed out\n");111 else if (exit_code)112 kunit_err(test, "Unknown error: %d\n", exit_code);113 114 try_catch->catch(try_catch->context);115}116EXPORT_SYMBOL_GPL(kunit_try_catch_run);117