mirror of
git://sourceware.org/git/glibc.git
synced 2024-12-21 04:31:04 +08:00
75 lines
2.4 KiB
ArmAsm
75 lines
2.4 KiB
ArmAsm
/* Copyright (C) 1999-2014 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Philip Blundell <philb@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, 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 (__vfork)
|
|
/* Save the PID value. */
|
|
GET_TLS (r2)
|
|
NEGOFF_ADJ_BASE2 (r2, r0, PID_OFFSET) /* Save the TLS addr in r2. */
|
|
ldr r3, NEGOFF_OFF1 (r2, PID_OFFSET) /* Load the saved PID. */
|
|
rsbs r0, r3, #0 /* Negate it, and test for zero. */
|
|
/* Use 0x80000000 if it was 0. See raise.c for how this is used. */
|
|
it eq
|
|
moveq r0, #0x80000000
|
|
str r0, NEGOFF_OFF1 (r2, PID_OFFSET) /* Store the temp PID. */
|
|
|
|
/* The DO_CALL macro saves r7 on the stack, to enable generation
|
|
of ARM unwind info. Since the stack is initially shared between
|
|
parent and child of vfork, that saved value could be corrupted.
|
|
To avoid this problem, we save r7 into ip as well, and restore
|
|
from there. */
|
|
mov ip, r7
|
|
cfi_register (r7, ip)
|
|
.fnstart
|
|
push { r7 }
|
|
cfi_adjust_cfa_offset (4)
|
|
.save { r7 }
|
|
ldr r7, =SYS_ify (vfork)
|
|
swi 0x0
|
|
.fnend
|
|
add sp, sp, #4
|
|
cfi_adjust_cfa_offset (-4)
|
|
mov r7, ip
|
|
cfi_restore (r7)
|
|
|
|
/* Restore the old PID value in the parent. */
|
|
cmp r0, #0 /* If we are the parent... */
|
|
it ne
|
|
strne r3, NEGOFF_OFF1 (r2, PID_OFFSET) /* restore the saved PID. */
|
|
|
|
cmn a1, #4096
|
|
it cc
|
|
RETINSTR(cc, lr)
|
|
|
|
b PLTJMP(SYSCALL_ERROR)
|
|
PSEUDO_END (__vfork)
|
|
libc_hidden_def (__vfork)
|
|
|
|
weak_alias (__vfork, vfork)
|
|
strong_alias (__vfork, __libc_vfork)
|