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/* $OpenBSD: rthread_fork.c,v 1.21 2017/07/30 19:48:30 tedu Exp $ */
/*
* Copyright (c) 2008 Kurt Miller <kurt@openbsd.org>
* Copyright (c) 2008 Philip Guenther <guenther@openbsd.org>
* Copyright (c) 2003 Daniel Eischen <deischen@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD: /repoman/r/ncvs/src/lib/libc_r/uthread/uthread_atfork.c,v 1.1 2004/12/10 03:36:45 grog Exp $
*/
#ifndef NO_PIC
#include <sys/types.h>
#include <sys/exec_elf.h>
#pragma weak _DYNAMIC
#endif
#include <errno.h>
#include <pthread.h>
#include <stdlib.h>
#include <tib.h>
#include <unistd.h>
#include "thread_private.h" /* in libc/include */
#include "rthread.h"
#include "rthread_cb.h"
/* make {fork,vfork,getthrid} call _thread_sys_{fork,vfork,getthrid} */
REDIRECT_SYSCALL(fork);
REDIRECT_SYSCALL(vfork);
REDIRECT_SYSCALL(getthrid);
static pid_t
_dofork(pid_t (*sys_fork)(void))
{
pthread_t me;
pid_t newid;
int i;
extern int _post_threaded;
if (!_threads_ready)
return sys_fork();
me = pthread_self();
/*
* Protect important libc/ld.so critical areas across the fork call.
* dlclose() will grab the atexit lock via __cxa_finalize() so lock
* the dl_lock first. malloc()/free() can use arc4random(), so lock
* malloc_lock before arc4_lock
*/
#ifndef NO_PIC
if (_DYNAMIC)
_rthread_dl_lock(0);
#endif
_thread_atexit_lock();
for (i = 0; i < _MALLOC_MUTEXES; i++)
_thread_malloc_lock(i);
_thread_arc4_lock();
newid = sys_fork();
_thread_arc4_unlock();
if (newid == 0)
_thread_malloc_reinit();
else
for (i = 0; i < _MALLOC_MUTEXES; i++)
_thread_malloc_unlock(i);
_thread_atexit_unlock();
if (newid == 0) {
struct tib *tib = me->tib;
#ifndef NO_PIC
/* reinitialize the lock in the child */
if (_DYNAMIC)
_rthread_dl_lock(2);
#endif
/* update this thread's structure */
tib->tib_tid = getthrid();
me->donesem.lock = _SPINLOCK_UNLOCKED;
me->flags_lock = _SPINLOCK_UNLOCKED;
/* reinit the thread list */
LIST_INIT(&_thread_list);
LIST_INSERT_HEAD(&_thread_list, me, threads);
_thread_lock = _SPINLOCK_UNLOCKED;
/* single threaded now */
__isthreaded = 0;
_post_threaded = 0; /* notyet... */
}
#ifndef NO_PIC
else if (_DYNAMIC)
_rthread_dl_lock(1);
#endif
return newid;
}
pid_t
_thread_fork(void)
{
return _dofork(&fork);
}
pid_t
_thread_vfork(void)
{
return _dofork(&vfork);
}
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