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/* Copyright (C) 2004-2016 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, see
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
#define _ERRNO_H 1
#include <bits/errno.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. */
ENTRY (__libc_vfork)
/* Save the PID value. */
stc gbr, r2
mov.w .L2, r0
mov.l @(r0,r2), r4
neg r4, r1
tst r1, r1
bf 1f
mov #1, r1
rotr r1
1:
mov.l r1, @(r0,r2)
mov.w .L1, r3
trapa #0x10
mov r0, r1
/* Restore the old PID value in the parent. */
tst r0, r0
bt.s 2f
stc gbr, r2
mov.w .L2, r0
mov.l r4, @(r0,r2)
mov r1, r0
2:
mov #-12, r2
shad r2, r1
not r1, r1 // r1=0 means r0 = -1 to -4095
tst r1, r1 // i.e. error in linux
bf .Lpseudo_end
SYSCALL_ERROR_HANDLER
.Lpseudo_end:
rts
nop
.L1:
.word __NR_vfork
.L2:
.word PID - TLS_PRE_TCB_SIZE
.align 2
PSEUDO_END (__libc_vfork)
#if IS_IN (libc)
weak_alias (__libc_vfork, vfork)
strong_alias (__libc_vfork, __vfork)
libc_hidden_def (__vfork)
#endif
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