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      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 2007 Sun Microsystems, Inc.  All rights reserved.
     24  * Use is subject to license terms.
     25  */
     26 
     27 #pragma ident	"@(#)signotify.c	1.15	07/08/03 SMI"
     28 
     29 #include <sys/param.h>
     30 #include <sys/types.h>
     31 #include <sys/sysmacros.h>
     32 #include <sys/systm.h>
     33 #include <sys/errno.h>
     34 #include <sys/proc.h>
     35 #include <sys/procset.h>
     36 #include <sys/fault.h>
     37 #include <sys/signal.h>
     38 #include <sys/siginfo.h>
     39 #include <sys/schedctl.h>
     40 #include <vm/as.h>
     41 #include <sys/debug.h>
     42 #include <sys/contract/process_impl.h>
     43 
     44 /*ARGSUSED*/
     45 static int
     46 copyin_siginfo(model_t datamodel, void *uaddr, k_siginfo_t *ksip)
     47 {
     48 #ifdef _SYSCALL32_IMPL
     49 	int ret;
     50 
     51 	if (datamodel == DATAMODEL_NATIVE) {
     52 #endif
     53 		return (copyin(uaddr, ksip, sizeof (k_siginfo_t)));
     54 #ifdef _SYSCALL32_IMPL
     55 	} else {
     56 		siginfo32_t si32;
     57 
     58 		if (ret = copyin(uaddr, &si32, sizeof (si32)))
     59 			return (ret);
     60 
     61 		siginfo_32tok(&si32, ksip);
     62 	}
     63 
     64 	return (0);
     65 #endif
     66 }
     67 
     68 /*
     69  * To find secured 64 bit id for signotify() call
     70  * This depends upon as_getmemid() which returns
     71  * unique vnode/offset for a user virtual address.
     72  */
     73 static u_longlong_t
     74 get_sigid(proc_t *p, caddr_t addr)
     75 {
     76 	u_longlong_t snid = 0;
     77 	memid_t memid;
     78 	quad_t *tquad = (quad_t *)&snid;
     79 
     80 	if (!as_getmemid(p->p_as, addr, &memid)) {
     81 		tquad->val[0] = (int)memid.val[0];
     82 		tquad->val[1] = (int)memid.val[1];
     83 	}
     84 	return (snid);
     85 }
     86 
     87 #define	SIGN_PTR(p, n)	&((signotifyq_t *)(&p->p_signhdr[1]))[n];
     88 
     89 int
     90 signotify(int cmd, siginfo_t *siginfo, signotify_id_t *sn_id)
     91 {
     92 	k_siginfo_t	info;
     93 	signotify_id_t	id;
     94 	proc_t		*p;
     95 	proc_t		*cp = curproc;
     96 	signotifyq_t	*snqp;
     97 	struct cred	*cr;
     98 	sigqueue_t	*sqp;
     99 	sigqhdr_t	*sqh;
    100 	u_longlong_t	sid;
    101 	model_t 	datamodel = get_udatamodel();
    102 
    103 	if (copyin(sn_id, &id, sizeof (signotify_id_t)))
    104 		return (set_errno(EFAULT));
    105 
    106 	if (id.sn_index >= _SIGNOTIFY_MAX || id.sn_index < 0)
    107 		return (set_errno(EINVAL));
    108 
    109 	switch (cmd) {
    110 	case SN_PROC:
    111 		/* get snid for the given user address of signotifyid_t */
    112 		sid = get_sigid(cp, (caddr_t)sn_id);
    113 
    114 		if (id.sn_pid > 0) {
    115 			mutex_enter(&pidlock);
    116 			if ((p = prfind(id.sn_pid)) != NULL) {
    117 				mutex_enter(&p->p_lock);
    118 				if (p->p_signhdr != NULL) {
    119 					snqp = SIGN_PTR(p, id.sn_index);
    120 					if (snqp->sn_snid == sid) {
    121 						mutex_exit(&p->p_lock);
    122 						mutex_exit(&pidlock);
    123 						return (set_errno(EBUSY));
    124 					}
    125 				}
    126 				mutex_exit(&p->p_lock);
    127 			}
    128 			mutex_exit(&pidlock);
    129 		}
    130 
    131 		if (copyin_siginfo(datamodel, siginfo, &info))
    132 			return (set_errno(EFAULT));
    133 
    134 		/* The si_code value must indicate the signal will be queued */
    135 		if (!sigwillqueue(info.si_signo, info.si_code))
    136 			return (set_errno(EINVAL));
    137 
    138 		if (cp->p_signhdr == NULL) {
    139 			/* Allocate signotify pool first time */
    140 			sqh = sigqhdralloc(sizeof (signotifyq_t),
    141 			    _SIGNOTIFY_MAX);
    142 			mutex_enter(&cp->p_lock);
    143 			if (cp->p_signhdr == NULL) {
    144 				/* hang the pool head on proc */
    145 				cp->p_signhdr = sqh;
    146 			} else {
    147 				/* another lwp allocated the pool, free ours */
    148 				sigqhdrfree(sqh);
    149 			}
    150 		} else {
    151 			mutex_enter(&cp->p_lock);
    152 		}
    153 
    154 		sqp = sigqalloc(cp->p_signhdr);
    155 		if (sqp == NULL) {
    156 			mutex_exit(&cp->p_lock);
    157 			return (set_errno(EAGAIN));
    158 		}
    159 		cr = CRED();
    160 		sqp->sq_info = info;
    161 		sqp->sq_info.si_pid = cp->p_pid;
    162 		sqp->sq_info.si_ctid = PRCTID(cp);
    163 		sqp->sq_info.si_zoneid = getzoneid();
    164 		sqp->sq_info.si_uid = crgetruid(cr);
    165 
    166 		/* fill the signotifyq_t fields */
    167 		((signotifyq_t *)sqp)->sn_snid = sid;
    168 
    169 		mutex_exit(&cp->p_lock);
    170 
    171 		/* complete the signotify_id_t fields */
    172 		id.sn_index = (signotifyq_t *)sqp - SIGN_PTR(cp, 0);
    173 		id.sn_pid = cp->p_pid;
    174 
    175 		break;
    176 
    177 	case SN_CANCEL:
    178 	case SN_SEND:
    179 
    180 		mutex_enter(&pidlock);
    181 		if ((id.sn_pid <= 0) || ((p = prfind(id.sn_pid)) == NULL)) {
    182 			mutex_exit(&pidlock);
    183 			return (set_errno(EINVAL));
    184 		}
    185 		mutex_enter(&p->p_lock);
    186 		mutex_exit(&pidlock);
    187 
    188 		if (p->p_signhdr == NULL) {
    189 			mutex_exit(&p->p_lock);
    190 			return (set_errno(EINVAL));
    191 		}
    192 
    193 		snqp = SIGN_PTR(p, id.sn_index);
    194 
    195 		if (snqp->sn_snid == 0) {
    196 			mutex_exit(&p->p_lock);
    197 			return (set_errno(EINVAL));
    198 		}
    199 
    200 		if (snqp->sn_snid != get_sigid(cp, (caddr_t)sn_id)) {
    201 			mutex_exit(&p->p_lock);
    202 			return (set_errno(EINVAL));
    203 		}
    204 
    205 		snqp->sn_snid = 0;
    206 
    207 		/* cmd == SN_CANCEL or signo == 0 (SIGEV_NONE) */
    208 		if (((sigqueue_t *)snqp)->sq_info.si_signo <= 0)
    209 			cmd = SN_CANCEL;
    210 
    211 		sigqsend(cmd, p, 0, (sigqueue_t *)snqp);
    212 		mutex_exit(&p->p_lock);
    213 
    214 		id.sn_pid = 0;
    215 		id.sn_index = 0;
    216 
    217 		break;
    218 
    219 	default :
    220 		return (set_errno(EINVAL));
    221 	}
    222 
    223 	if (copyout(&id, sn_id, sizeof (signotify_id_t)))
    224 		return (set_errno(EFAULT));
    225 
    226 	return (0);
    227 }
    228 
    229 int
    230 sigresend(int sig, siginfo_t *siginfo, sigset_t *mask)
    231 {
    232 	kthread_t *t = curthread;
    233 	proc_t *p = ttoproc(t);
    234 	klwp_t *lwp = ttolwp(t);
    235 	sigqueue_t *sqp = kmem_zalloc(sizeof (*sqp), KM_SLEEP);
    236 	sigset_t set;
    237 	k_sigset_t kset;
    238 	int error;
    239 
    240 	if (sig <= 0 || sig >= NSIG || sigismember(&cantmask, sig)) {
    241 		error = EINVAL;
    242 		goto bad;
    243 	}
    244 
    245 	if (siginfo == NULL) {
    246 		sqp->sq_info.si_signo = sig;
    247 		sqp->sq_info.si_code = SI_NOINFO;
    248 	} else {
    249 		if (copyin_siginfo(get_udatamodel(), siginfo, &sqp->sq_info)) {
    250 			error = EFAULT;
    251 			goto bad;
    252 		}
    253 		if (sqp->sq_info.si_signo != sig) {
    254 			error = EINVAL;
    255 			goto bad;
    256 		}
    257 	}
    258 
    259 	if (copyin(mask, &set, sizeof (set))) {
    260 		error = EFAULT;
    261 		goto bad;
    262 	}
    263 	sigutok(&set, &kset);
    264 
    265 	mutex_enter(&p->p_lock);
    266 	if (lwp->lwp_cursig || lwp->lwp_curinfo) {
    267 		mutex_exit(&p->p_lock);
    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 	mutex_exit(&p->p_lock);
    277 
    278 	t->t_sig_check = 1;
    279 	return (0);
    280 bad:
    281 	kmem_free(sqp, sizeof (*sqp));
    282 	return (set_errno(error));
    283 }
    284