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/* Copyright (C) 2011-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
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, see
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
#define __ASSEMBLY__ /* for kernel headers */
#include <linux/sched.h>
#include <asm/signal.h>
#include <tcb-offsets.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. */
.text
ENTRY (__vfork)
{
addli r11, tp, PID_OFFSET /* Point at PID. */
movei r13, 1
}
{
LD4U r12, r11 /* Load the saved PID. */
shli r13, r13, 31 /* Build 0x80000000. */
}
sub r12, zero, r12 /* Negate it. */
CMOVEQZ r12, r12, r13 /* Replace zero pids. */
ST4 r11, r12 /* Store the temporary PID. */
{
moveli r0, CLONE_VFORK | CLONE_VM | SIGCHLD
move r1, zero
}
{
move r2, zero
move r3, zero
}
moveli TREG_SYSCALL_NR_NAME, __NR_clone
swint1
BEQZ r0, 1f /* If we are the parent... */
{
addli r11, tp, PID_OFFSET /* Point at PID. */
movei r13, 1
}
{
LD4U r12, r11 /* Load the saved PID. */
shli r13, r13, 31 /* Build 0x80000000. */
}
{
CMPEQ r13, r12, r12 /* Test for that value. */
sub r12, zero, r12 /* Re-negate it. */
}
CMOVNEZ r12, r13, zero /* Replace zero pids. */
ST4 r11, r12 /* Restore the PID. */
1:
BNEZ r1, 0f
jrp lr
PSEUDO_END (__vfork)
libc_hidden_def (__vfork)
weak_alias (__vfork, vfork)
strong_alias (__vfork, __libc_vfork)
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