xref: /titanic_50/usr/src/uts/common/syscall/sigtimedwait.c (revision e127a3e717f822eb855235fa3bd08235b2cf533d)
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 2007 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 ret;
106 	int error = 0;
107 	k_siginfo_t info, *infop;
108 	model_t datamodel = get_udatamodel();
109 
110 	if (timeoutp) {
111 		timespec_t now;
112 
113 		gethrestime(&now);
114 		if (datamodel == DATAMODEL_NATIVE) {
115 			if (copyin(timeoutp, &sig_timeout,
116 			    sizeof (sig_timeout)))
117 				return (set_errno(EFAULT));
118 		} else {
119 			timespec32_t timeout32;
120 
121 			if (copyin(timeoutp, &timeout32, sizeof (timeout32)))
122 				return (set_errno(EFAULT));
123 			TIMESPEC32_TO_TIMESPEC(&sig_timeout, &timeout32)
124 		}
125 
126 		if (itimerspecfix(&sig_timeout))
127 			return (set_errno(EINVAL));
128 		/*
129 		 * Convert the timespec value into absolute time.
130 		 */
131 		timespecadd(&sig_timeout, &now);
132 		rqtp = &sig_timeout;
133 	}
134 	if (copyin(setp, &set, sizeof (set)))
135 		return (set_errno(EFAULT));
136 	sigutok(&set, &kset);
137 	if (sigisempty(&kset))
138 		return (set_errno(EINVAL));
139 
140 	mutex_enter(&p->p_lock);
141 	/*
142 	 * set the thread's signal mask to unmask
143 	 * those signals in the specified set.
144 	 */
145 	schedctl_finish_sigblock(t);
146 	oldmask = t->t_hold;
147 	sigdiffset(&t->t_hold, &kset);
148 
149 	/*
150 	 * Wait until we take a signal or until
151 	 * the absolute future time is passed.
152 	 */
153 	while ((ret = cv_waituntil_sig(&t->t_delay_cv, &p->p_lock,
154 	    rqtp)) > 0)
155 		continue;
156 	if (ret == -1)
157 		error = EAGAIN;
158 
159 	/*
160 	 * Restore thread's signal mask to its previous value.
161 	 */
162 	t->t_hold = oldmask;
163 	t->t_sig_check = 1;	/* so post_syscall sees new t_hold mask */
164 
165 	if (error) {
166 		mutex_exit(&p->p_lock);
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 || !sigismember(&kset, lwp->lwp_cursig)) {
173 		mutex_exit(&p->p_lock);
174 		/*
175 		 * lwp_cursig is zero if pokelwps() awakened cv_wait_sig().
176 		 * This happens if some other thread in this process called
177 		 * forkall() or exit().
178 		 */
179 		return (set_errno(EINTR));
180 	}
181 
182 	if (lwp->lwp_curinfo)
183 		infop = &lwp->lwp_curinfo->sq_info;
184 	else {
185 		infop = &info;
186 		bzero(infop, sizeof (info));
187 		infop->si_signo = lwp->lwp_cursig;
188 		infop->si_code = SI_NOINFO;
189 	}
190 
191 	lwp->lwp_ru.nsignals++;
192 	ret = lwp->lwp_cursig;
193 	DTRACE_PROC2(signal__clear, int, ret, ksiginfo_t *, infop);
194 	lwp->lwp_cursig = 0;
195 	lwp->lwp_extsig = 0;
196 	mutex_exit(&p->p_lock);
197 
198 	if (siginfop)
199 		ret = copyout_siginfo(datamodel, infop, siginfop);
200 	if (lwp->lwp_curinfo) {
201 		siginfofree(lwp->lwp_curinfo);
202 		lwp->lwp_curinfo = NULL;
203 	}
204 	return (ret);
205 }
206