2 * Copyright (c) 2005 David Xu <davidxu@freebsd.org>
3 * Copyright (c) 2003 Daniel Eischen <deischen@freebsd.org>
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Neither the name of the author nor the names of any co-contributors
12 * may be used to endorse or promote products derived from this software
13 * without specific prior written permission.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SPDX-License-Identifier: BSD-3-Clause
31 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
32 * All rights reserved.
34 * Redistribution and use in source and binary forms, with or without
35 * modification, are permitted provided that the following conditions
37 * 1. Redistributions of source code must retain the above copyright
38 * notice, this list of conditions and the following disclaimer.
39 * 2. Redistributions in binary form must reproduce the above copyright
40 * notice, this list of conditions and the following disclaimer in the
41 * documentation and/or other materials provided with the distribution.
42 * 3. Neither the name of the author nor the names of any co-contributors
43 * may be used to endorse or promote products derived from this software
44 * without specific prior written permission.
46 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
47 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
48 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
49 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
50 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
51 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
52 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
53 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
54 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
55 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60 #include <sys/syscall.h>
61 #include "namespace.h"
69 #include "un-namespace.h"
71 #include "libc_private.h"
72 #include "rtld_lock.h"
73 #include "thr_private.h"
75 __weak_reference(_thr_atfork, _pthread_atfork);
76 __weak_reference(_thr_atfork, pthread_atfork);
78 bool _thr_after_fork = false;
81 _thr_atfork(void (*prepare)(void), void (*parent)(void),
84 struct pthread *curthread;
85 struct pthread_atfork *af;
89 if ((af = malloc(sizeof(struct pthread_atfork))) == NULL)
92 curthread = _get_curthread();
93 af->prepare = prepare;
96 THR_CRITICAL_ENTER(curthread);
97 _thr_rwl_wrlock(&_thr_atfork_lock);
98 TAILQ_INSERT_TAIL(&_thr_atfork_list, af, qe);
99 _thr_rwl_unlock(&_thr_atfork_lock);
100 THR_CRITICAL_LEAVE(curthread);
105 __pthread_cxa_finalize(struct dl_phdr_info *phdr_info)
107 atfork_head temp_list = TAILQ_HEAD_INITIALIZER(temp_list);
108 struct pthread *curthread;
109 struct pthread_atfork *af, *af1;
113 curthread = _get_curthread();
114 THR_CRITICAL_ENTER(curthread);
115 _thr_rwl_wrlock(&_thr_atfork_lock);
116 TAILQ_FOREACH_SAFE(af, &_thr_atfork_list, qe, af1) {
117 if (__elf_phdr_match_addr(phdr_info, af->prepare) ||
118 __elf_phdr_match_addr(phdr_info, af->parent) ||
119 __elf_phdr_match_addr(phdr_info, af->child)) {
120 TAILQ_REMOVE(&_thr_atfork_list, af, qe);
121 TAILQ_INSERT_TAIL(&temp_list, af, qe);
124 _thr_rwl_unlock(&_thr_atfork_lock);
125 THR_CRITICAL_LEAVE(curthread);
126 while ((af = TAILQ_FIRST(&temp_list)) != NULL) {
127 TAILQ_REMOVE(&temp_list, af, qe);
130 _thr_tsd_unload(phdr_info);
131 _thr_sigact_unload(phdr_info);
139 struct thr_fork_args {
140 enum thr_fork_mode mode;
146 thr_fork_impl(const struct thr_fork_args *a)
148 struct pthread *curthread;
149 struct pthread_atfork *af;
151 int errsave, cancelsave;
153 int rtld_locks[MAX_RTLD_LOCKS];
155 if (!_thr_is_inited()) {
158 return (__sys_fork());
160 return (__sys_pdfork(a->fdp, a->flags));
167 curthread = _get_curthread();
168 cancelsave = curthread->no_cancel;
169 curthread->no_cancel = 1;
170 _thr_rwl_rdlock(&_thr_atfork_lock);
172 /* Run down atfork prepare handlers. */
173 TAILQ_FOREACH_REVERSE(af, &_thr_atfork_list, atfork_head, qe) {
174 if (af->prepare != NULL)
179 * Block all signals until we reach a safe point.
181 _thr_signal_block(curthread);
182 _thr_signal_prefork();
185 * All bets are off as to what should happen soon if the parent
186 * process was not so kindly as to set up pthread fork hooks to
187 * relinquish all running threads.
189 if (_thr_isthreaded() != 0) {
191 __thr_malloc_prefork(curthread);
193 __thr_pshared_atfork_pre();
194 _rtld_atfork_pre(rtld_locks);
200 * Fork a new process.
201 * There is no easy way to pre-resolve the __sys_fork symbol
202 * without performing the fork. Use the syscall(2)
203 * indirection, the syscall symbol is resolved in
204 * _thr_rtld_init() with side-effect free call.
208 ret = syscall(SYS_fork);
211 ret = syscall(SYS_pdfork, a->fdp, a->flags);
222 curthread->cancel_pending = 0;
223 curthread->flags &= ~(THR_FLAGS_NEED_SUSPEND|THR_FLAGS_DETACHED);
226 * Thread list will be reinitialized, and later we call
227 * _libpthread_init(), it will add us back to list.
229 curthread->tlflags &= ~TLFLAGS_IN_TDLIST;
231 /* before thr_self() */
233 __thr_malloc_postfork(curthread);
235 /* child is a new kernel thread. */
236 thr_self(&curthread->tid);
238 /* clear other threads locked us. */
239 _thr_umutex_init(&curthread->lock);
240 _mutex_fork(curthread);
242 _thr_signal_postfork_child();
245 _thr_after_fork = true;
246 _rtld_atfork_post(rtld_locks);
247 _thr_after_fork = false;
248 __thr_pshared_atfork_post();
252 /* reinitalize library. */
253 _libpthread_init(curthread);
255 /* atfork is reinitialized by _libpthread_init()! */
256 _thr_rwl_rdlock(&_thr_atfork_lock);
264 /* Ready to continue, unblock signals. */
265 _thr_signal_unblock(curthread);
267 /* Run down atfork child handlers. */
268 TAILQ_FOREACH(af, &_thr_atfork_list, qe) {
269 if (af->child != NULL)
272 _thr_rwlock_unlock(&_thr_atfork_lock);
273 curthread->no_cancel = cancelsave;
278 _thr_signal_postfork();
281 __thr_malloc_postfork(curthread);
282 _rtld_atfork_post(rtld_locks);
283 __thr_pshared_atfork_post();
287 /* Ready to continue, unblock signals. */
288 _thr_signal_unblock(curthread);
290 /* Run down atfork parent handlers. */
291 TAILQ_FOREACH(af, &_thr_atfork_list, qe) {
292 if (af->parent != NULL)
296 _thr_rwlock_unlock(&_thr_atfork_lock);
297 curthread->no_cancel = cancelsave;
298 /* test async cancel */
299 if (curthread->cancel_async)
300 _thr_testcancel(curthread);
307 __weak_reference(__thr_fork, _fork);
312 struct thr_fork_args a;
315 return (thr_fork_impl(&a));
319 __thr_pdfork(int *fdp, int flags)
321 struct thr_fork_args a;
323 a.mode = MODE_PDFORK;
326 return (thr_fork_impl(&a));