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/* Copyright (C) 1999, 2002, 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Andreas Schwab <schwab@gnu.org>.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <sysdep-cancel.h>
#define _ERRNO_H 1
#include <bits/errno.h>
#include <kernel-features.h>
/* Clone the calling process, but without copying the whole address space.
The calling process is suspended until the new process exits or is
replaced by a call to `execve'. Return -1 for errors, 0 to the new process,
and the process ID of the new process to the old process. */
ENTRY (__vfork)
#ifdef __NR_vfork
# ifdef SHARED
# if !defined HAVE_HIDDEN || !USE___THREAD
SETUP_PIC_REG (cx)
# else
call __i686.get_pc_thunk.cx
# endif
addl $_GLOBAL_OFFSET_TABLE_, %ecx
cmpl $0, __libc_pthread_functions@GOTOFF(%ecx)
# else
.weak pthread_create
movl $pthread_create, %eax
testl %eax, %eax
# endif
jne HIDDEN_JUMPTARGET (__fork)
/* Pop the return PC value into ECX. */
popl %ecx
/* Stuff the syscall number in EAX and enter into the kernel. */
movl $SYS_ify (vfork), %eax
int $0x80
/* Jump to the return PC. Don't jump directly since this
disturbs the branch target cache. Instead push the return
address back on the stack. */
pushl %ecx
cmpl $-4095, %eax
/* Branch forward if it failed. */
# ifdef __ASSUME_VFORK_SYSCALL
jae SYSCALL_ERROR_LABEL
.Lpseudo_end:
# else
jae .Lerror
# endif
ret
# ifndef __ASSUME_VFORK_SYSCALL
.Lerror:
/* Check if vfork syscall is known at all. */
cmpl $-ENOSYS, %eax
jne SYSCALL_ERROR_LABEL
# endif
#endif
#ifndef __ASSUME_VFORK_SYSCALL
/* If we don't have vfork, fork is close enough. */
movl $SYS_ify (fork), %eax
int $0x80
cmpl $-4095, %eax
jae SYSCALL_ERROR_LABEL
.Lpseudo_end:
ret
#elif !defined __NR_vfork
# error "__NR_vfork not available and __ASSUME_VFORK_SYSCALL defined"
#endif
PSEUDO_END (__vfork)
libc_hidden_def (__vfork)
weak_alias (__vfork, vfork)
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