kernel/syscall/signotify.c

   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
  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
  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
  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
 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 }