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
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
/* Copyright (C) 1995-2012 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/>. */
#include <sysdep-cancel.h>
#include <socketcall.h>
#include <tls.h>
#include <kernel-features.h>
#define EINVAL 22
#define ENOSYS 38
#ifdef __ASSUME_ACCEPT4
# define errlabel SYSCALL_ERROR_LABEL
#else
# define errlabel .Lerr
.data
have_accept4:
.long 0
#endif
.text
/* The socket-oriented system calls are handled unusally in Linux/i386.
They are all gated through the single `socketcall' system call number.
`socketcall' takes two arguments: the first is the subcode, specifying
which socket function is being called; and the second is a pointer to
the arguments to the specific function. */
.globl __libc_accept4
ENTRY (__libc_accept4)
#ifdef CENABLE
SINGLE_THREAD_P
jne 1f
#endif
/* Save registers. */
movl %ebx, %edx
cfi_register (3, 2)
movl $SYS_ify(socketcall), %eax /* System call number in %eax. */
movl $SOCKOP_accept4, %ebx /* Subcode is first arg to syscall. */
lea 4(%esp), %ecx /* Address of args is 2nd arg. */
/* Do the system call trap. */
ENTER_KERNEL
/* Restore registers. */
movl %edx, %ebx
cfi_restore (3)
/* %eax is < 0 if there was an error. */
cmpl $-125, %eax
jae errlabel
/* Successful; return the syscall's value. */
ret
#ifdef CENABLE
/* We need one more register. */
1: pushl %esi
cfi_adjust_cfa_offset(4)
/* Enable asynchronous cancellation. */
CENABLE
movl %eax, %esi
cfi_offset(6, -8) /* %esi */
/* Save registers. */
movl %ebx, %edx
cfi_register (3, 2)
movl $SYS_ify(socketcall), %eax /* System call number in %eax. */
movl $SOCKOP_accept4, %ebx /* Subcode is first arg to syscall. */
lea 8(%esp), %ecx /* Address of args is 2nd arg. */
/* Do the system call trap. */
ENTER_KERNEL
/* Restore registers. */
movl %edx, %ebx
cfi_restore (3)
/* Restore the cancellation. */
xchgl %esi, %eax
CDISABLE
/* Restore registers. */
movl %esi, %eax
popl %esi
cfi_restore (6)
cfi_adjust_cfa_offset(-4)
/* %eax is < 0 if there was an error. */
cmpl $-125, %eax
jae errlabel
/* Successful; return the syscall's value. */
ret
#endif
#ifndef __ASSUME_ACCEPT4
/* The kernel returns -EINVAL for unknown socket operations.
We need to convert that error to an ENOSYS error. */
.Lerr: cmpl $-EINVAL, %eax
jne SYSCALL_ERROR_LABEL
/* Save registers. */
pushl %ebx
cfi_adjust_cfa_offset(4)
cfi_offset(ebx, -8)
# ifdef PIC
SETUP_PIC_REG (dx)
addl $_GLOBAL_OFFSET_TABLE_, %edx
movl have_accept4@GOTOFF(%edx), %eax
# else
movl have_accept4, %eax
# endif
testl %eax, %eax
jne 1f
/* Try another call, this time with the FLAGS parameter
cleared and an invalid file descriptor. This call will not
cause any harm and it will return immediately. */
movl $-1, 8(%esp)
movl $0, 20(%esp)
movl $SYS_ify(socketcall), %eax /* System call number in %eax. */
movl $SOCKOP_accept4, %ebx /* Subcode is first arg to syscall. */
lea 8(%esp), %ecx /* Address of args is 2nd arg. */
/* Do the system call trap. */
ENTER_KERNEL
cmpl $-EINVAL, %eax
movl $-1, %eax
je 3f
movl $1, %eax
3:
# ifdef PIC
movl %eax, have_accept4@GOTOFF(%edx)
# else
movl %eax, have_accept4
# endif
testl %eax, %eax
1: movl $-EINVAL, %eax
jns 2f
movl $-ENOSYS, %eax
/* Restore registers. */
2: popl %ebx
cfi_restore (ebx)
jmp SYSCALL_ERROR_LABEL
#endif
PSEUDO_END (__libc_accept4)
weak_alias (__libc_accept4, accept4)
|
