1/* Copyright (C) 1999-2022 Free Software Foundation, Inc.
2   This file is part of the GNU C Library.
3
4   The GNU C Library is free software; you can redistribute it and/or
5   modify it under the terms of the GNU Lesser General Public
6   License as published by the Free Software Foundation; either
7   version 2.1 of the License, or (at your option) any later version.
8
9   The GNU C Library is distributed in the hope that it will be useful,
10   but WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12   Lesser General Public License for more details.
13
14   You should have received a copy of the GNU Lesser General Public
15   License along with the GNU C Library.  If not, see
16   <https://www.gnu.org/licenses/>.  */
17
18#include <sysdep.h>
19#define _ERRNO_H	1
20#include <bits/errno.h>
21#include <tcb-offsets.h>
22
23
24/* Clone the calling process, but without copying the whole address space.
25   The calling process is suspended until the new process exits or is
26   replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
27   and the process ID of the new process to the old process.  */
28
29ENTRY (__vfork)
30	/* The DO_CALL macro saves r7 on the stack, to enable generation
31	   of ARM unwind info.  Since the stack is initially shared between
32	   parent and child of vfork, that saved value could be corrupted.
33	   To avoid this problem, we save r7 into ip as well, and restore
34	   from there.  */
35	mov	ip, r7
36	cfi_register (r7, ip)
37	.fnstart
38	push	{ r7 }
39	cfi_adjust_cfa_offset (4)
40	.save { r7 }
41	ldr	r7, =SYS_ify (vfork)
42	swi	0x0
43	.fnend
44	add	sp, sp, #4
45	cfi_adjust_cfa_offset (-4)
46	mov	r7, ip
47	cfi_restore (r7)
48
49	cmn	a1, #4096
50	it	cc
51	RETINSTR(cc, lr)
52
53	b	PLTJMP(SYSCALL_ERROR)
54PSEUDO_END (__vfork)
55libc_hidden_def (__vfork)
56
57weak_alias (__vfork, vfork)
58strong_alias (__vfork, __libc_vfork)
59