xref: /titanic_41/usr/src/uts/common/syscall/signotify.c (revision 7be238fce69ba74b2163fc0ea898dfdc01a4aa22)
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/sysmacros.h>
30 #include <sys/systm.h>
31 #include <sys/errno.h>
32 #include <sys/proc.h>
33 #include <sys/procset.h>
34 #include <sys/fault.h>
35 #include <sys/signal.h>
36 #include <sys/siginfo.h>
37 #include <sys/schedctl.h>
38 #include <vm/as.h>
39 #include <sys/debug.h>
40 #include <sys/contract/process_impl.h>
41 
42 /*ARGSUSED*/
43 static int
copyin_siginfo(model_t datamodel,void * uaddr,k_siginfo_t * ksip)44 copyin_siginfo(model_t datamodel, void *uaddr, k_siginfo_t *ksip)
45 {
46 #ifdef _SYSCALL32_IMPL
47 	int ret;
48 
49 	if (datamodel == DATAMODEL_NATIVE) {
50 #endif
51 		return (copyin(uaddr, ksip, sizeof (k_siginfo_t)));
52 #ifdef _SYSCALL32_IMPL
53 	} else {
54 		siginfo32_t si32;
55 
56 		if (ret = copyin(uaddr, &si32, sizeof (si32)))
57 			return (ret);
58 
59 		siginfo_32tok(&si32, ksip);
60 	}
61 
62 	return (0);
63 #endif
64 }
65 
66 /*
67  * To find secured 64 bit id for signotify() call
68  * This depends upon as_getmemid() which returns
69  * unique vnode/offset for a user virtual address.
70  */
71 static u_longlong_t
get_sigid(proc_t * p,caddr_t addr)72 get_sigid(proc_t *p, caddr_t addr)
73 {
74 	u_longlong_t snid = 0;
75 	memid_t memid;
76 	quad_t *tquad = (quad_t *)&snid;
77 
78 	if (!as_getmemid(p->p_as, addr, &memid)) {
79 		tquad->val[0] = (int)memid.val[0];
80 		tquad->val[1] = (int)memid.val[1];
81 	}
82 	return (snid);
83 }
84 
85 #define	SIGN_PTR(p, n)	&((signotifyq_t *)(&p->p_signhdr[1]))[n];
86 
87 int
signotify(int cmd,siginfo_t * siginfo,signotify_id_t * sn_id)88 signotify(int cmd, siginfo_t *siginfo, signotify_id_t *sn_id)
89 {
90 	k_siginfo_t	info;
91 	signotify_id_t	id;
92 	proc_t		*p;
93 	proc_t		*cp = curproc;
94 	signotifyq_t	*snqp;
95 	struct cred	*cr;
96 	sigqueue_t	*sqp;
97 	sigqhdr_t	*sqh;
98 	u_longlong_t	sid;
99 	model_t 	datamodel = get_udatamodel();
100 
101 	if (copyin(sn_id, &id, sizeof (signotify_id_t)))
102 		return (set_errno(EFAULT));
103 
104 	if (id.sn_index >= _SIGNOTIFY_MAX || id.sn_index < 0)
105 		return (set_errno(EINVAL));
106 
107 	switch (cmd) {
108 	case SN_PROC:
109 		/* get snid for the given user address of signotifyid_t */
110 		sid = get_sigid(cp, (caddr_t)sn_id);
111 
112 		if (id.sn_pid > 0) {
113 			mutex_enter(&pidlock);
114 			if ((p = prfind(id.sn_pid)) != NULL) {
115 				mutex_enter(&p->p_lock);
116 				if (p->p_signhdr != NULL) {
117 					snqp = SIGN_PTR(p, id.sn_index);
118 					if (snqp->sn_snid == sid) {
119 						mutex_exit(&p->p_lock);
120 						mutex_exit(&pidlock);
121 						return (set_errno(EBUSY));
122 					}
123 				}
124 				mutex_exit(&p->p_lock);
125 			}
126 			mutex_exit(&pidlock);
127 		}
128 
129 		if (copyin_siginfo(datamodel, siginfo, &info))
130 			return (set_errno(EFAULT));
131 
132 		/* The si_code value must indicate the signal will be queued */
133 		if (!sigwillqueue(info.si_signo, info.si_code))
134 			return (set_errno(EINVAL));
135 
136 		if (cp->p_signhdr == NULL) {
137 			/* Allocate signotify pool first time */
138 			sqh = sigqhdralloc(sizeof (signotifyq_t),
139 			    _SIGNOTIFY_MAX);
140 			mutex_enter(&cp->p_lock);
141 			if (cp->p_signhdr == NULL) {
142 				/* hang the pool head on proc */
143 				cp->p_signhdr = sqh;
144 			} else {
145 				/* another lwp allocated the pool, free ours */
146 				sigqhdrfree(sqh);
147 			}
148 		} else {
149 			mutex_enter(&cp->p_lock);
150 		}
151 
152 		sqp = sigqalloc(cp->p_signhdr);
153 		if (sqp == NULL) {
154 			mutex_exit(&cp->p_lock);
155 			return (set_errno(EAGAIN));
156 		}
157 		cr = CRED();
158 		sqp->sq_info = info;
159 		sqp->sq_info.si_pid = cp->p_pid;
160 		sqp->sq_info.si_ctid = PRCTID(cp);
161 		sqp->sq_info.si_zoneid = getzoneid();
162 		sqp->sq_info.si_uid = crgetruid(cr);
163 
164 		/* fill the signotifyq_t fields */
165 		((signotifyq_t *)sqp)->sn_snid = sid;
166 
167 		mutex_exit(&cp->p_lock);
168 
169 		/* complete the signotify_id_t fields */
170 		id.sn_index = (signotifyq_t *)sqp - SIGN_PTR(cp, 0);
171 		id.sn_pid = cp->p_pid;
172 
173 		break;
174 
175 	case SN_CANCEL:
176 	case SN_SEND:
177 
178 		sid =  get_sigid(cp, (caddr_t)sn_id);
179 		mutex_enter(&pidlock);
180 		if ((id.sn_pid <= 0) || ((p = prfind(id.sn_pid)) == NULL)) {
181 			mutex_exit(&pidlock);
182 			return (set_errno(EINVAL));
183 		}
184 		mutex_enter(&p->p_lock);
185 		mutex_exit(&pidlock);
186 
187 		if (p->p_signhdr == NULL) {
188 			mutex_exit(&p->p_lock);
189 			return (set_errno(EINVAL));
190 		}
191 
192 		snqp = SIGN_PTR(p, id.sn_index);
193 
194 		if (snqp->sn_snid == 0) {
195 			mutex_exit(&p->p_lock);
196 			return (set_errno(EINVAL));
197 		}
198 
199 		if (snqp->sn_snid != sid) {
200 			mutex_exit(&p->p_lock);
201 			return (set_errno(EINVAL));
202 		}
203 
204 		snqp->sn_snid = 0;
205 
206 		/* cmd == SN_CANCEL or signo == 0 (SIGEV_NONE) */
207 		if (((sigqueue_t *)snqp)->sq_info.si_signo <= 0)
208 			cmd = SN_CANCEL;
209 
210 		sigqsend(cmd, p, 0, (sigqueue_t *)snqp);
211 		mutex_exit(&p->p_lock);
212 
213 		id.sn_pid = 0;
214 		id.sn_index = 0;
215 
216 		break;
217 
218 	default :
219 		return (set_errno(EINVAL));
220 	}
221 
222 	if (copyout(&id, sn_id, sizeof (signotify_id_t)))
223 		return (set_errno(EFAULT));
224 
225 	return (0);
226 }
227 
228 int
sigresend(int sig,siginfo_t * siginfo,sigset_t * mask)229 sigresend(int sig, siginfo_t *siginfo, sigset_t *mask)
230 {
231 	kthread_t *t = curthread;
232 	klwp_t *lwp = ttolwp(t);
233 	sigqueue_t *sqp = kmem_zalloc(sizeof (*sqp), KM_SLEEP);
234 	sigset_t set;
235 	k_sigset_t kset;
236 	int error;
237 
238 	if (sig <= 0 || sig >= NSIG || sigismember(&cantmask, sig)) {
239 		error = EINVAL;
240 		goto bad;
241 	}
242 
243 	if (siginfo == NULL) {
244 		sqp->sq_info.si_signo = sig;
245 		sqp->sq_info.si_code = SI_NOINFO;
246 	} else {
247 		if (copyin_siginfo(get_udatamodel(), siginfo, &sqp->sq_info)) {
248 			error = EFAULT;
249 			goto bad;
250 		}
251 		if (sqp->sq_info.si_signo != sig) {
252 			error = EINVAL;
253 			goto bad;
254 		}
255 	}
256 
257 	if (copyin(mask, &set, sizeof (set))) {
258 		error = EFAULT;
259 		goto bad;
260 	}
261 	sigutok(&set, &kset);
262 
263 	/*
264 	 * We don't need to acquire p->p_lock here;
265 	 * we are manipulating thread-private data.
266 	 */
267 	if (lwp->lwp_cursig || lwp->lwp_curinfo) {
268 		t->t_sig_check = 1;
269 		error = EAGAIN;
270 		goto bad;
271 	}
272 	lwp->lwp_cursig = sig;
273 	lwp->lwp_curinfo = sqp;
274 	schedctl_finish_sigblock(t);
275 	t->t_hold = kset;
276 	t->t_sig_check = 1;
277 	return (0);
278 bad:
279 	kmem_free(sqp, sizeof (*sqp));
280 	return (set_errno(error));
281 }
282