glibc/sysdeps/unix/bsd/i386/vfork.S
Andreas Jaeger 41bdb6e20c Update to LGPL v2.1.
2001-07-06  Paul Eggert  <eggert@twinsun.com>

	* manual/argp.texi: Remove ignored LGPL copyright notice; it's
	not appropriate for documentation anyway.
	* manual/libc-texinfo.sh: "Library General Public License" ->
	"Lesser General Public License".

2001-07-06  Andreas Jaeger  <aj@suse.de>

	* All files under GPL/LGPL version 2: Place under LGPL version
	2.1.
2001-07-06 04:58:11 +00:00

40 lines
1.6 KiB
ArmAsm

/* Copyright (C) 1993, 1994, 1995, 1997 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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.h>
/* Since vfork shares the address space between the parent and child,
we must take care to avoid the child unwinding the stack frame and
clobbering it for the parent. */
.text
ENTRY (__vfork)
popl scratch /* Save the return PC in a register. */
DO_CALL (vfork, 0) /* Do the system call. */
pushl scratch /* Put the return PC back on the stack. */
jb syscall_error /* Branch if error. */
/* R1 is now 0 for the parent and 1 for the child. Decrement it to
make it -1 (all bits set) for the parent, and 0 (no bits set)
for the child. Then AND it with R0, so the parent gets
R0&-1==R0, and the child gets R0&0==0. */
decl r1
andl r1, r0
ret
weak_alias (__vfork, vfork)