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
|
/*
* Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by John Birrell.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <signal.h>
#include <errno.h>
#include <pthread.h>
#include "thr_private.h"
LT10_COMPAT_PRIVATE(_sigaction);
LT10_COMPAT_DEFAULT(sigaction);
__weak_reference(_sigaction, sigaction);
int
_sigaction(int sig, const struct sigaction * act, struct sigaction * oact)
{
int ret = 0;
int err = 0;
struct sigaction newact, oldact;
struct pthread *curthread;
kse_critical_t crit;
/* Check if the signal number is out of range: */
if (sig < 1 || sig > _SIG_MAXSIG) {
/* Return an invalid argument: */
errno = EINVAL;
ret = -1;
} else {
if (act)
newact = *act;
crit = _kse_critical_enter();
curthread = _get_curthread();
KSE_LOCK_ACQUIRE(curthread->kse, &_thread_signal_lock);
oldact = _thread_sigact[sig - 1];
/* Check if a signal action was supplied: */
if (act != NULL) {
/* Set the new signal handler: */
_thread_sigact[sig - 1] = newact;
}
/*
* Check if the kernel needs to be advised of a change
* in signal action:
*/
if (act != NULL) {
newact.sa_flags |= SA_SIGINFO;
/*
* Check if the signal handler is being set to
* the default or ignore handlers:
*/
if (newact.sa_handler != SIG_DFL &&
newact.sa_handler != SIG_IGN) {
/*
* Specify the thread kernel signal
* handler:
*/
newact.sa_handler = (void (*) ())_thr_sig_handler;
}
/*
* Install libpthread signal handler wrapper
* for SIGINFO signal if threads dump enabled
* even if a user set the signal handler to
* SIG_DFL or SIG_IGN.
*/
if (sig == SIGINFO && _thr_dump_enabled()) {
newact.sa_handler =
(void (*) ())_thr_sig_handler;
}
/* Change the signal action in the kernel: */
if (__sys_sigaction(sig, &newact, NULL) != 0) {
_thread_sigact[sig - 1] = oldact;
/* errno is in kse, will copy it to thread */
err = errno;
ret = -1;
}
}
KSE_LOCK_RELEASE(curthread->kse, &_thread_signal_lock);
_kse_critical_leave(crit);
/*
* Check if the existing signal action structure contents are
* to be returned:
*/
if (oact != NULL) {
/* Return the existing signal action contents: */
*oact = oldact;
}
if (ret != 0) {
/* Return errno to thread */
errno = err;
}
}
/* Return the completion status: */
return (ret);
}
|
