xref: /netbsd-src/lib/libc/gen/signal.c (revision 4be2f99d7b796075be09b940699672ca22c01984)
1 /*	$NetBSD: signal.c,v 1.16 2024/01/03 18:41:53 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1985, 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 #if 0
35 static char sccsid[] = "@(#)signal.c	8.1 (Berkeley) 6/4/93";
36 #else
37 __RCSID("$NetBSD: signal.c,v 1.16 2024/01/03 18:41:53 christos Exp $");
38 #endif
39 #endif /* LIBC_SCCS and not lint */
40 
41 /*
42  * Almost backwards compatible signal.
43  */
44 #include "namespace.h"
45 #include "extern.h"
46 #include <signal.h>
47 
48 #ifdef __weak_alias
__weak_alias(signal,_signal)49 __weak_alias(signal,_signal)
50 #endif
51 
52 sigset_t __sigintr;		/* shared with siginterrupt */
53 
54 sig_t
55 signal(int s, sig_t a)
56 {
57 	struct sigaction sa, osa;
58 
59 	sa.sa_handler = a;
60 	sigemptyset(&sa.sa_mask);
61 	sa.sa_flags = 0;
62 	if (!sigismember(&__sigintr, s))
63 		sa.sa_flags |= SA_RESTART;
64 	if (sigaction(s, &sa, &osa) < 0)
65 		return (SIG_ERR);
66 	return (osa.sa_handler);
67 }
68 
69 void
bsd_signal(int sig,void (* func)(int))70 (*bsd_signal(int sig, void (*func)(int)))(int)
71 {
72 	struct sigaction act, oact;
73 
74 	act.sa_handler = func;
75 	act.sa_flags = SA_RESTART;
76 
77 	sigemptyset(&act.sa_mask);
78 	sigaddset(&act.sa_mask, sig);
79 	if (sigaction(sig, &act, &oact) < 0)
80 		return (SIG_ERR);
81 
82 	return (oact.sa_handler);
83 }
84