xref: /titanic_41/usr/src/uts/common/syscall/sigtimedwait.c (revision 9524a69f24734e80c50bfc33c4f1bce173d465a1)
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 (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #include <sys/param.h>
28 #include <sys/types.h>
29 #include <sys/bitmap.h>
30 #include <sys/sysmacros.h>
31 #include <sys/systm.h>
32 #include <sys/user.h>
33 #include <sys/errno.h>
34 #include <sys/proc.h>
35 #include <sys/fault.h>
36 #include <sys/procset.h>
37 #include <sys/signal.h>
38 #include <sys/siginfo.h>
39 #include <sys/time.h>
40 #include <sys/kmem.h>
41 #include <sys/schedctl.h>
42 #include <sys/debug.h>
43 #include <sys/condvar_impl.h>
44 #include <sys/model.h>
45 #include <sys/sdt.h>
46 #include <sys/zone.h>
47 
48 static int
copyout_siginfo(model_t datamodel,k_siginfo_t * ksip,void * uaddr)49 copyout_siginfo(model_t datamodel, k_siginfo_t *ksip, void *uaddr)
50 {
51 	zoneid_t zoneid = getzoneid();
52 
53 	if (datamodel == DATAMODEL_NATIVE) {
54 		if (SI_FROMUSER(ksip) && zoneid != GLOBAL_ZONEID &&
55 		    zoneid != ksip->si_zoneid) {
56 			k_siginfo_t sani_sip = *ksip;
57 			sani_sip.si_pid = curproc->p_zone->zone_zsched->p_pid;
58 			sani_sip.si_uid = 0;
59 			sani_sip.si_ctid = -1;
60 			sani_sip.si_zoneid = zoneid;
61 			if (copyout(&sani_sip, uaddr, sizeof (sani_sip)))
62 				return (set_errno(EFAULT));
63 		} else {
64 			if (copyout(ksip, uaddr, sizeof (*ksip)))
65 				return (set_errno(EFAULT));
66 		}
67 	}
68 #ifdef _SYSCALL32_IMPL
69 	else {
70 		siginfo32_t si32;
71 
72 		siginfo_kto32(ksip, &si32);
73 		if (SI_FROMUSER(ksip) && zoneid != GLOBAL_ZONEID &&
74 		    zoneid != ksip->si_zoneid) {
75 			si32.si_pid = curproc->p_zone->zone_zsched->p_pid;
76 			si32.si_uid = 0;
77 			si32.si_ctid = -1;
78 			si32.si_zoneid = zoneid;
79 		}
80 		if (copyout(&si32, uaddr, sizeof (si32)))
81 			return (set_errno(EFAULT));
82 	}
83 #endif
84 	return (ksip->si_signo);
85 }
86 
87 /*
88  * Wait until a signal within a specified set is posted or until the
89  * time interval 'timeout' if specified.  The signal is caught but
90  * not delivered. The value of the signal is returned to the caller.
91  */
92 int
sigtimedwait(sigset_t * setp,siginfo_t * siginfop,timespec_t * timeoutp)93 sigtimedwait(sigset_t *setp, siginfo_t *siginfop, timespec_t *timeoutp)
94 {
95 	sigset_t set;
96 	k_sigset_t oldmask;
97 	kthread_t *t = curthread;
98 	klwp_t *lwp = ttolwp(t);
99 	proc_t *p = ttoproc(t);
100 	timespec_t sig_timeout;
101 	timespec_t *rqtp = NULL;
102 	int timecheck = 0;
103 	int ret;
104 	int error = 0;
105 	k_siginfo_t info, *infop;
106 	model_t datamodel = get_udatamodel();
107 
108 	if (timeoutp) {
109 		timespec_t now;
110 
111 		timecheck = timechanged;
112 		gethrestime(&now);
113 		if (datamodel == DATAMODEL_NATIVE) {
114 			if (copyin(timeoutp, &sig_timeout,
115 			    sizeof (sig_timeout)))
116 				return (set_errno(EFAULT));
117 		} else {
118 			timespec32_t timeout32;
119 
120 			if (copyin(timeoutp, &timeout32, sizeof (timeout32)))
121 				return (set_errno(EFAULT));
122 			TIMESPEC32_TO_TIMESPEC(&sig_timeout, &timeout32)
123 		}
124 
125 		if (itimerspecfix(&sig_timeout))
126 			return (set_errno(EINVAL));
127 		/*
128 		 * Convert the timespec value into absolute time.
129 		 */
130 		timespecadd(&sig_timeout, &now);
131 		rqtp = &sig_timeout;
132 	}
133 	if (copyin(setp, &set, sizeof (set)))
134 		return (set_errno(EFAULT));
135 	sigutok(&set, &t->t_sigwait);
136 	if (sigisempty(&t->t_sigwait))
137 		return (set_errno(EINVAL));
138 
139 	mutex_enter(&p->p_lock);
140 	/*
141 	 * set the thread's signal mask to unmask
142 	 * those signals in the specified set.
143 	 */
144 	schedctl_finish_sigblock(t);
145 	oldmask = t->t_hold;
146 	sigdiffset(&t->t_hold, &t->t_sigwait);
147 
148 	/*
149 	 * Wait until we take a signal or until
150 	 * the absolute future time is passed.
151 	 */
152 	while ((ret = cv_waituntil_sig(&t->t_delay_cv, &p->p_lock,
153 	    rqtp, timecheck)) > 0)
154 		continue;
155 	if (ret == -1)
156 		error = EAGAIN;
157 
158 	/*
159 	 * Restore thread's signal mask to its previous value.
160 	 */
161 	t->t_hold = oldmask;
162 	t->t_sig_check = 1;	/* so post_syscall sees new t_hold mask */
163 
164 	if (error) {
165 		mutex_exit(&p->p_lock);
166 		sigemptyset(&t->t_sigwait);
167 		return (set_errno(error));	/* timer expired */
168 	}
169 	/*
170 	 * Don't bother with signal if it is not in request set.
171 	 */
172 	if (lwp->lwp_cursig == 0 ||
173 	    !sigismember(&t->t_sigwait, lwp->lwp_cursig)) {
174 		mutex_exit(&p->p_lock);
175 		/*
176 		 * lwp_cursig is zero if pokelwps() awakened cv_wait_sig().
177 		 * This happens if some other thread in this process called
178 		 * forkall() or exit().
179 		 */
180 		sigemptyset(&t->t_sigwait);
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 	sigemptyset(&t->t_sigwait);
207 	return (ret);
208 }
209