1 /*
2 * Copyright (C) 2008 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <unistd.h>
30
31 #include <android/fdsan.h>
32
33 #include "private/bionic_defs.h"
34 #include "private/bionic_fdtrack.h"
35 #include "pthread_internal.h"
36
37 __BIONIC_WEAK_FOR_NATIVE_BRIDGE_INLINE
__clone_for_fork()38 int __clone_for_fork() {
39 pthread_internal_t* self = __get_thread();
40
41 int result = clone(nullptr, nullptr, (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID | SIGCHLD),
42 nullptr, nullptr, nullptr, &(self->tid));
43
44 if (result == 0) {
45 // Update the cached pid in child, since clone() will not set it directly (as
46 // self->tid is updated by the kernel).
47 self->set_cached_pid(gettid());
48 }
49
50 return result;
51 }
52
fork()53 int fork() {
54 __bionic_atfork_run_prepare();
55
56 int result = __clone_for_fork();
57
58 if (result == 0) {
59 // Disable fdsan and fdtrack post-fork, so we don't falsely trigger on processes that
60 // fork, close all of their fds, and then exec.
61 android_fdsan_set_error_level(ANDROID_FDSAN_ERROR_LEVEL_DISABLED);
62 android_fdtrack_set_globally_enabled(false);
63
64 // Reset the stack_and_tls VMA name so it doesn't end with a tid from the
65 // parent process.
66 __set_stack_and_tls_vma_name(true);
67
68 __bionic_atfork_run_child();
69 } else {
70 __bionic_atfork_run_parent();
71 }
72 return result;
73 }
74