Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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#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
37void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context)
38{
39 struct kunit *test = try_catch->test;
40 struct task_struct *task_struct;
41 struct completion *task_done;
42 int exit_code, time_remaining;
43
44 try_catch->context = context;
45 try_catch->try_result = 0;
46 task_struct = kthread_create(kunit_generic_run_threadfn_adapter,
47 try_catch, "kunit_try_catch_thread");
48 if (IS_ERR(task_struct)) {
49 try_catch->try_result = PTR_ERR(task_struct);
50 try_catch->catch(try_catch->context);
51 return;
52 }
53 get_task_struct(task_struct);
54 /*
55 * As for a vfork(2), task_struct->vfork_done (pointing to the
56 * underlying kthread->exited) can be used to wait for the end of a
57 * kernel thread. It is set to NULL when the thread exits, so we
58 * keep a copy here.
59 */
60 task_done = task_struct->vfork_done;
61 wake_up_process(task_struct);
62
63 time_remaining = wait_for_completion_timeout(
64 task_done, try_catch->timeout);
65 if (time_remaining == 0) {
66 try_catch->try_result = -ETIMEDOUT;
67 kthread_stop(task_struct);
68 }
69
70 put_task_struct(task_struct);
71 exit_code = try_catch->try_result;
72
73 if (!exit_code)
74 return;
75
76 if (exit_code == -EFAULT)
77 try_catch->try_result = 0;
78 else if (exit_code == -EINTR) {
79 if (test->last_seen.file)
80 kunit_err(test, "try faulted: last line seen %s:%d\n",
81 test->last_seen.file, test->last_seen.line);
82 else
83 kunit_err(test, "try faulted\n");
84 } else if (exit_code == -ETIMEDOUT)
85 kunit_err(test, "try timed out\n");
86 else if (exit_code)
87 kunit_err(test, "Unknown error: %d\n", exit_code);
88
89 try_catch->catch(try_catch->context);
90}
91EXPORT_SYMBOL_GPL(kunit_try_catch_run);