xref: /illumos-gate/usr/src/uts/common/syscall/sigtimedwait.c (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
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 /*
23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <sys/param.h>
30 #include <sys/types.h>
31 #include <sys/bitmap.h>
32 #include <sys/sysmacros.h>
33 #include <sys/systm.h>
34 #include <sys/user.h>
35 #include <sys/errno.h>
36 #include <sys/proc.h>
37 #include <sys/fault.h>
38 #include <sys/procset.h>
39 #include <sys/signal.h>
40 #include <sys/siginfo.h>
41 #include <sys/time.h>
42 #include <sys/kmem.h>
43 #include <sys/schedctl.h>
44 #include <sys/debug.h>
45 #include <sys/condvar_impl.h>
46 #include <sys/model.h>
47 #include <sys/sdt.h>
48 #include <sys/zone.h>
49 
50 static int
51 copyout_siginfo(model_t datamodel, k_siginfo_t *ksip, void *uaddr)
52 {
53 	zoneid_t zoneid = getzoneid();
54 
55 	if (datamodel == DATAMODEL_NATIVE) {
56 		if (SI_FROMUSER(ksip) && zoneid != GLOBAL_ZONEID &&
57 		    zoneid != ksip->si_zoneid) {
58 			k_siginfo_t sani_sip = *ksip;
59 			sani_sip.si_pid = curproc->p_zone->zone_zsched->p_pid;
60 			sani_sip.si_uid = 0;
61 			sani_sip.si_ctid = -1;
62 			sani_sip.si_zoneid = zoneid;
63 			if (copyout(&sani_sip, uaddr, sizeof (sani_sip)))
64 				return (set_errno(EFAULT));
65 		} else {
66 			if (copyout(ksip, uaddr, sizeof (*ksip)))
67 				return (set_errno(EFAULT));
68 		}
69 	}
70 #ifdef _SYSCALL32_IMPL
71 	else {
72 		siginfo32_t si32;
73 
74 		siginfo_kto32(ksip, &si32);
75 		if (SI_FROMUSER(ksip) && zoneid != GLOBAL_ZONEID &&
76 		    zoneid != ksip->si_zoneid) {
77 			si32.si_pid = curproc->p_zone->zone_zsched->p_pid;
78 			si32.si_uid = 0;
79 			si32.si_ctid = -1;
80 			si32.si_zoneid = zoneid;
81 		}
82 		if (copyout(&si32, uaddr, sizeof (si32)))
83 			return (set_errno(EFAULT));
84 	}
85 #endif
86 	return (ksip->si_signo);
87 }
88 
89 /*
90  * Wait until a signal within a specified set is posted or until the
91  * time interval 'timeout' if specified.  The signal is caught but
92  * not delivered. The value of the signal is returned to the caller.
93  */
94 int
95 sigtimedwait(sigset_t *setp, siginfo_t *siginfop, timespec_t *timeoutp)
96 {
97 	sigset_t set;
98 	k_sigset_t kset;
99 	k_sigset_t oldmask;
100 	kthread_t *t = curthread;
101 	klwp_t *lwp = ttolwp(t);
102 	proc_t *p = ttoproc(t);
103 	timespec_t sig_timeout;
104 	timespec_t *rqtp = NULL;
105 	int timecheck = 0;
106 	int ret;
107 	int error = 0;
108 	k_siginfo_t info, *infop;
109 	model_t datamodel = get_udatamodel();
110 
111 	if (timeoutp) {
112 		timespec_t now;
113 
114 		timecheck = timechanged;
115 		gethrestime(&now);
116 		if (datamodel == DATAMODEL_NATIVE) {
117 			if (copyin(timeoutp, &sig_timeout,
118 			    sizeof (sig_timeout)))
119 				return (set_errno(EFAULT));
120 		} else {
121 			timespec32_t timeout32;
122 
123 			if (copyin(timeoutp, &timeout32, sizeof (timeout32)))
124 				return (set_errno(EFAULT));
125 			TIMESPEC32_TO_TIMESPEC(&sig_timeout, &timeout32)
126 		}
127 
128 		if (itimerspecfix(&sig_timeout))
129 			return (set_errno(EINVAL));
130 		/*
131 		 * Convert the timespec value into absolute time.
132 		 */
133 		timespecadd(&sig_timeout, &now);
134 		rqtp = &sig_timeout;
135 	}
136 	if (copyin(setp, &set, sizeof (set)))
137 		return (set_errno(EFAULT));
138 	sigutok(&set, &kset);
139 	if (sigisempty(&kset))
140 		return (set_errno(EINVAL));
141 
142 	mutex_enter(&p->p_lock);
143 	/*
144 	 * set the thread's signal mask to unmask
145 	 * those signals in the specified set.
146 	 */
147 	schedctl_finish_sigblock(t);
148 	oldmask = t->t_hold;
149 	sigdiffset(&t->t_hold, &kset);
150 
151 	/*
152 	 * Wait until we take a signal or until
153 	 * the absolute future time is passed.
154 	 */
155 	while ((ret = cv_waituntil_sig(&t->t_delay_cv, &p->p_lock,
156 	    rqtp, timecheck)) > 0)
157 		continue;
158 	if (ret == -1)
159 		error = EAGAIN;
160 
161 	/*
162 	 * Restore thread's signal mask to its previous value.
163 	 */
164 	t->t_hold = oldmask;
165 	t->t_sig_check = 1;	/* so post_syscall sees new t_hold mask */
166 
167 	if (error) {
168 		mutex_exit(&p->p_lock);
169 		return (set_errno(error));	/* timer expired */
170 	}
171 	/*
172 	 * Don't bother with signal if it is not in request set.
173 	 */
174 	if (lwp->lwp_cursig == 0 || !sigismember(&kset, lwp->lwp_cursig)) {
175 		mutex_exit(&p->p_lock);
176 		/*
177 		 * lwp_cursig is zero if pokelwps() awakened cv_wait_sig().
178 		 * This happens if some other thread in this process called
179 		 * forkall() or exit().
180 		 */
181 		return (set_errno(EINTR));
182 	}
183 
184 	if (lwp->lwp_curinfo)
185 		infop = &lwp->lwp_curinfo->sq_info;
186 	else {
187 		infop = &info;
188 		bzero(infop, sizeof (info));
189 		infop->si_signo = lwp->lwp_cursig;
190 		infop->si_code = SI_NOINFO;
191 	}
192 
193 	lwp->lwp_ru.nsignals++;
194 	ret = lwp->lwp_cursig;
195 	DTRACE_PROC2(signal__clear, int, ret, ksiginfo_t *, infop);
196 	lwp->lwp_cursig = 0;
197 	lwp->lwp_extsig = 0;
198 	mutex_exit(&p->p_lock);
199 
200 	if (siginfop)
201 		ret = copyout_siginfo(datamodel, infop, siginfop);
202 	if (lwp->lwp_curinfo) {
203 		siginfofree(lwp->lwp_curinfo);
204 		lwp->lwp_curinfo = NULL;
205 	}
206 	return (ret);
207 }
208