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
|
/* Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Richard Henderson (rth@tamu.edu)
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. 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>
#include <asm-syntax.h>
/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg); */
.text
ENTRY(__clone)
/* Sanity check arguments. */
movl $-EINVAL,%eax
movl 4(%esp),%ecx /* no NULL function pointers */
testl %ecx,%ecx
jz syscall_error
movl 8(%esp),%ecx /* no NULL stack pointers */
testl %ecx,%ecx
jz syscall_error
/* Insert the argument onto the new stack. */
subl $8,%ecx
movl 16(%esp),%eax /* no negative argument counts */
movl %eax,4(%ecx)
/* Save the function pointer as the zeroth argument.
It will be popped off in the child in the ebx frobbing below. */
movl 4(%esp),%eax
movl %eax,0(%ecx)
/* Do the system call */
pushl %ebx
movl 16(%esp),%ebx
movl $SYS_ify(clone),%eax
int $0x80
popl %ebx
test %eax,%eax
jl syscall_error
jz thread_start
L(pseudo_end):
ret
thread_start:
subl %ebp,%ebp /* terminate the stack frame */
call *%ebx
#ifdef PIC
call L(here)
L(here):
popl %ebx
addl $_GLOBAL_OFFSET_TABLE_+[.-L(here)], %ebx
#endif
pushl %eax
call JUMPTARGET (_exit)
PSEUDO_END (__clone)
weak_alias (__clone, clone)
|
