mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-23 13:30:06 +00:00
60 lines
2.0 KiB
ArmAsm
60 lines
2.0 KiB
ArmAsm
/* Copyright (C) 1999-2015 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>
|
|
|
|
/* 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)
|
|
|
|
/* Save the TCB-cached PID away in w3, and then negate the TCB
|
|
field. But if it's zero, set it to 0x80000000 instead. See
|
|
raise.c for the logic that relies on this value. */
|
|
mrs x2, tpidr_el0
|
|
sub x2, x2, #PTHREAD_SIZEOF
|
|
ldr w3, [x2, #PTHREAD_PID_OFFSET]
|
|
mov w1, #0x80000000
|
|
negs w0, w3
|
|
csel w0, w1, w0, eq
|
|
str w0, [x2, #PTHREAD_PID_OFFSET]
|
|
|
|
mov x0, #0x4111 /* CLONE_VM | CLONE_VFORK | SIGCHLD */
|
|
mov x1, sp
|
|
DO_CALL (clone, 2)
|
|
|
|
/* Restore the original value of the TCB cache of the PID, if we're
|
|
the parent. But in the child (syscall return value equals zero),
|
|
leave things as they are. */
|
|
cbz x0, 1f
|
|
str w3, [x2, #PTHREAD_PID_OFFSET]
|
|
1:
|
|
cmn x0, #4095
|
|
b.cs .Lsyscall_error
|
|
RET
|
|
|
|
PSEUDO_END (__vfork)
|
|
libc_hidden_def (__vfork)
|
|
|
|
weak_alias (__vfork, vfork)
|
|
strong_alias (__vfork, __libc_vfork)
|