1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
|
/* Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Pat Beirne <patb@corelcomputer.com>
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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
/* clone() is even more special than fork() as it mucks with stacks
and invokes a function in the right context after its all over. */
#include <sysdep.h>
#define _ERRNO_H 1
#include <bits/errno.h>
/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg); */
.text
ENTRY(__clone)
@ sanity check args
cmp r0, #0
cmpne r1, #0
moveq r0, #-EINVAL
beq PLTJMP(syscall_error)
@ insert the args onto the new stack
sub r1, r1, #8
str r3, [r1, #4]
@ save the function pointer as the 0th element
str r0, [r1]
@ do the system call
@ get flags
mov r0, r2
@ new sp is already in r1
swi SYS_ify(clone)
movs a1, a1
blt PLTJMP(C_SYMBOL_NAME(__syscall_error))
RETINSTR(movne, pc, lr)
@ pick the function arg and call address off the stack and execute
ldr r0, [sp, #4]
mov lr, pc
ldr pc, [sp]
@ and we are done, passing the return value through r0
b PLTJMP(_exit)
PSEUDO_END (__clone)
weak_alias (__clone, clone)
|
