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
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
|
/* Copyright (C) 1999-2019 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/>. */
/* 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>
#include <tcb-offsets.h>
/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
pid_t *ptid, void *tls, pid_t *ctid); */
.text
ENTRY(__clone)
/* sanity check arguments. */
tst r4, r4
bt/s 0f
tst r5, r5
bf 1f
0:
bra .Lsyscall_error
mov #-EINVAL,r0
1:
/* insert the args onto the new stack */
mov.l r7, @-r5
/* save the function pointer as the 0th element */
mov.l r4, @-r5
/* do the system call */
mov r6, r4
mov.l @r15, r6
mov.l @(8,r15), r7
mov.l @(4,r15), r0
mov #+SYS_ify(clone), r3
trapa #0x15
mov r0, r1
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 .Lclone_end
.Lsyscall_error:
SYSCALL_ERROR_HANDLER
.Lclone_end:
tst r0, r0
bt 2f
.Lpseudo_end:
rts
nop
2:
/* terminate the stack frame */
mov #0, r14
/* thread starts */
mov.l @r15, r1
jsr @r1
mov.l @(4,r15), r4
/* we are done, passing the return value through r0 */
mov r0, r4
mov #+SYS_ify(exit), r3
trapa #0x15
.align 2
.LG:
.long _GLOBAL_OFFSET_TABLE_
.L3:
.long PLTJMP(C_SYMBOL_NAME(_exit))
PSEUDO_END (__clone)
libc_hidden_def (__clone)
weak_alias (__clone, clone)
|
