1 /*
2 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the author nor the names of any co-contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $FreeBSD: stable/10/lib/libkse/thread/thr_sigaction.c 174689 2007-12-16 23:29:57Z deischen $
30 */
31
32 #include "namespace.h"
33 #include <signal.h>
34 #include <errno.h>
35 #include <pthread.h>
36 #include "un-namespace.h"
37 #include "thr_private.h"
38
39 __weak_reference(_sigaction, sigaction);
40
41 int
_sigaction(int sig,const struct sigaction * act,struct sigaction * oact)42 _sigaction(int sig, const struct sigaction * act, struct sigaction * oact)
43 {
44 int ret = 0;
45 int err = 0;
46 struct sigaction newact, oldact;
47 struct pthread *curthread;
48 kse_critical_t crit;
49
50 /* Check if the signal number is out of range: */
51 if (sig < 1 || sig > _SIG_MAXSIG) {
52 /* Return an invalid argument: */
53 errno = EINVAL;
54 ret = -1;
55 } else {
56 if (act)
57 newact = *act;
58
59 crit = _kse_critical_enter();
60 curthread = _get_curthread();
61 KSE_LOCK_ACQUIRE(curthread->kse, &_thread_signal_lock);
62
63 oldact = _thread_sigact[sig - 1];
64
65 /* Check if a signal action was supplied: */
66 if (act != NULL) {
67 /* Set the new signal handler: */
68 _thread_sigact[sig - 1] = newact;
69 }
70
71 /*
72 * Check if the kernel needs to be advised of a change
73 * in signal action:
74 */
75 if (act != NULL) {
76
77 newact.sa_flags |= SA_SIGINFO;
78
79 /*
80 * Check if the signal handler is being set to
81 * the default or ignore handlers:
82 */
83 if (newact.sa_handler != SIG_DFL &&
84 newact.sa_handler != SIG_IGN) {
85 /*
86 * Specify the thread kernel signal
87 * handler:
88 */
89 newact.sa_sigaction = _thr_sig_handler;
90 }
91 /*
92 * Install libpthread signal handler wrapper
93 * for SIGINFO signal if threads dump enabled
94 * even if a user set the signal handler to
95 * SIG_DFL or SIG_IGN.
96 */
97 if (sig == SIGINFO && _thr_dump_enabled()) {
98 newact.sa_sigaction = _thr_sig_handler;
99 }
100 /* Change the signal action in the kernel: */
101 if (__sys_sigaction(sig, &newact, NULL) != 0) {
102 _thread_sigact[sig - 1] = oldact;
103 /* errno is in kse, will copy it to thread */
104 err = errno;
105 ret = -1;
106 }
107 }
108 KSE_LOCK_RELEASE(curthread->kse, &_thread_signal_lock);
109 _kse_critical_leave(crit);
110 /*
111 * Check if the existing signal action structure contents are
112 * to be returned:
113 */
114 if (oact != NULL) {
115 /* Return the existing signal action contents: */
116 *oact = oldact;
117 }
118 if (ret != 0) {
119 /* Return errno to thread */
120 errno = err;
121 }
122 }
123
124 /* Return the completion status: */
125 return (ret);
126 }
127