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
|
/* Copyright (C) 2008 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by David Bartley <dtbartle@csclub.uwaterloo.ca>, 2008.
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. */
#include <sysdep.h>
#include <ucontext_i.h>
ENTRY(__swapcontext)
/* load ucp (arg) into %ecx */
movl 4(%esp), %ecx
/* load return address into %eax */
movl 0(%esp), %eax
/* push ucp, subcall number, and return address */
pushl %ecx; cfi_adjust_cfa_offset (4)
pushl $SYS_SUB_getcontext; cfi_adjust_cfa_offset (4)
pushl %eax; cfi_adjust_cfa_offset (4)
/* call context syscall */
DO_CALL(context, 2)
/* Jump if not error. */
jnb 1f;
/* pop args from stack */
addl $12, %esp; cfi_adjust_cfa_offset (-12);
/* Jump to error label. */
jmp SYSCALL_ERROR_LABEL;
1:
/* pop args from stack */
addl $12, %esp; cfi_adjust_cfa_offset (-12);
/* load ucp (arg) into %ecx */
movl 4(%esp), %ecx
/* save %esp */
leal 4(%esp), %eax
movl %eax, oUESP(%ecx)
/* save %eip */
movl 0(%esp), %eax
movl %eax, oEIP(%ecx)
/* return 0 on success */
xorl %eax, %eax
movl %eax, oEAX(%ecx)
/* load ocp (arg 2) into %edx */
movl 8(%esp), %edx
/* push ucp */
pushl %edx; cfi_adjust_cfa_offset (4);
/* call __setcontext */
call __setcontext
/* pop ucp */
addl $4, %esp; cfi_adjust_cfa_offset (-4)
/* __setcontext sets the return (%eax) */
L(pseudo_end):
ret
PSEUDO_END(__swapcontext)
weak_alias (__swapcontext, swapcontext)
|
