xref: /titanic_41/usr/src/lib/libbc/libc/gen/sys5/sighold.c (revision 74e20cfe817b82802b16fac8690dadcda76f54f5)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 #pragma ident	"%Z%%M%	%I%	%E% SMI"
23 
24 /*
25  * Copyright (c) 1987 Sun Microsystems, Inc.
26  */
27 
28 #include <errno.h>
29 #include <sys/signal.h>
30 
31 int
32 sighold(sig)
33 	int sig;
34 {
35 
36 	if (sig == SIGKILL) {
37 		errno = EINVAL;
38 		return (-1);	/* sigblock quietly disallows SIGKILL */
39 	}
40 	(void) sigblock(sigmask(sig));
41 	return (0);		/* SVID specifies 0 return on success */
42 }
43 
44 int
45 sigrelse(sig)
46 	int sig;
47 {
48 
49 	if (sig == SIGKILL) {
50 		errno = EINVAL;
51 		return (-1);	/* sigsetmask quietly disallows SIGKILL */
52 	}
53 	(void) sigsetmask(sigblock(0) & ~sigmask(sig));
54 	return (0);		/* SVID specifies 0 return on success */
55 }
56 
57 int
58 sigignore(sig)
59 	int sig;
60 {
61 	struct sigvec vec;
62 
63 	if (sig == SIGKILL) {
64 		errno = EINVAL;
65 		return (-1);	/* sigsetmask quietly disallows SIGKILL */
66 	}
67 	if (sigvec(sig, (struct sigvec *)0, &vec) < 0)
68 		return (-1);
69 	vec.sv_handler = SIG_IGN;
70 	if (sigvec(sig, &vec, (struct sigvec *)0) < 0)
71 		return (-1);
72 	(void) sigsetmask(sigblock(0) & ~sigmask(sig));
73 	return (0);		/* SVID specifies 0 return on success */
74 }
75 
76 void (*
77 sigset(sig, func))()
78 	int sig;
79 	void (*func)();
80 {
81 	struct sigvec newvec;
82 	int newmask;
83 	struct sigvec oldvec;
84 	int oldmask;
85 
86 	if (sigvec(sig, (struct sigvec *)0, &oldvec) < 0)
87 		return (SIG_ERR);
88 	oldmask = sigblock(0);
89 	newvec = oldvec;
90 	newvec.sv_flags |= SV_INTERRUPT;
91 	newvec.sv_flags &= ~SV_RESETHAND;
92 	newvec.sv_mask = 0;
93 	newmask = oldmask;
94 	if (func == SIG_HOLD) {
95 		/*
96 		 * Signal will be held.  Set the bit for that
97 		 * signal in the signal mask.  Leave the action
98 		 * alone.
99 		 */
100 		newmask |= sigmask(sig);
101 	} else {
102 		/*
103 		 * Signal will not be held.  Clear the bit
104 		 * for it in the signal mask.  Set the action
105 		 * for it.
106 		 */
107 		newmask &= ~sigmask(sig);
108 		newvec.sv_handler = func;
109 	}
110 	if (sigvec(sig, &newvec, (struct sigvec *)0) < 0)
111 		return (SIG_ERR);
112 	if (sigsetmask(newmask) < 0)
113 		return (SIG_ERR);
114 	if (oldmask & sigmask(sig))
115 		return (SIG_HOLD);      /* signal was held */
116 	else
117 		return (oldvec.sv_handler);
118 }
119