1/*
2 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
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 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the author nor the names of any co-contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $FreeBSD$
30 */
31
32#include "namespace.h"
33#include <errno.h>
34#include <string.h>
35#include <stdlib.h>
36#include <unistd.h>
37#include <fcntl.h>
38#include <pthread.h>
39#include <spinlock.h>
40#include <sys/signalvar.h>
41#include "un-namespace.h"
42
43#include "libc_private.h"
44#include "thr_private.h"
45
46pid_t	_fork(void);
47
48__weak_reference(_fork, fork);
49
50pid_t
51_fork(void)
52{
53	sigset_t sigset, oldset;
54	struct pthread *curthread;
55	struct pthread_atfork *af;
56	pid_t ret;
57	int errsave;
58
59	curthread = _get_curthread();
60
61	if (!_kse_isthreaded()) {
62		SIGFILLSET(sigset);
63		__sys_sigprocmask(SIG_SETMASK, &sigset, &oldset);
64		ret = __sys_fork();
65		if (ret == 0)
66			/* Child */
67			__sys_sigprocmask(SIG_SETMASK, &curthread->sigmask,
68			    NULL);
69		else
70			__sys_sigprocmask(SIG_SETMASK, &oldset, NULL);
71		return (ret);
72	}
73
74	/*
75	 * Masks all signals until we reach a safe point in
76	 * _kse_single_thread, and the signal masks will be
77	 * restored in that function, for M:N thread, all
78	 * signals were already masked in kernel atomically,
79	 * we only need to do this for bound thread.
80	 */
81	if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM) {
82		SIGFILLSET(sigset);
83		__sys_sigprocmask(SIG_SETMASK, &sigset, &oldset);
84	}
85
86	_pthread_mutex_lock(&_thr_atfork_mutex);
87
88	/* Run down atfork prepare handlers. */
89	TAILQ_FOREACH_REVERSE(af, &_thr_atfork_list, atfork_head, qe) {
90		if (af->prepare != NULL)
91			af->prepare();
92	}
93
94	/* Fork a new process: */
95	if (_kse_isthreaded() != 0) {
96		_malloc_prefork();
97	}
98	if ((ret = __sys_fork()) == 0) {
99		/* Child process */
100		errsave = errno;
101
102		/* Kernel signal mask is restored in _kse_single_thread */
103		_kse_single_thread(curthread);
104
105		/* Run down atfork child handlers. */
106		TAILQ_FOREACH(af, &_thr_atfork_list, qe) {
107			if (af->child != NULL)
108				af->child();
109		}
110		_thr_mutex_reinit(&_thr_atfork_mutex);
111	} else {
112		if (_kse_isthreaded() != 0) {
113			_malloc_postfork();
114		}
115		errsave = errno;
116		if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM) {
117			__sys_sigprocmask(SIG_SETMASK, &oldset, NULL);
118		}
119		/* Run down atfork parent handlers. */
120		TAILQ_FOREACH(af, &_thr_atfork_list, qe) {
121			if (af->parent != NULL)
122				af->parent();
123		}
124		_pthread_mutex_unlock(&_thr_atfork_mutex);
125	}
126	errno = errsave;
127
128	/* Return the process ID: */
129	return (ret);
130}
131