The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_sig.c

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    1 /*-
    2  * Copyright (c) 1982, 1986, 1989, 1991, 1993
    3  *      The Regents of the University of California.  All rights reserved.
    4  * (c) UNIX System Laboratories, Inc.
    5  * All or some portions of this file are derived from material licensed
    6  * to the University of California by American Telephone and Telegraph
    7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
    8  * the permission of UNIX System Laboratories, Inc.
    9  *
   10  * Redistribution and use in source and binary forms, with or without
   11  * modification, are permitted provided that the following conditions
   12  * are met:
   13  * 1. Redistributions of source code must retain the above copyright
   14  *    notice, this list of conditions and the following disclaimer.
   15  * 2. Redistributions in binary form must reproduce the above copyright
   16  *    notice, this list of conditions and the following disclaimer in the
   17  *    documentation and/or other materials provided with the distribution.
   18  * 4. Neither the name of the University nor the names of its contributors
   19  *    may be used to endorse or promote products derived from this software
   20  *    without specific prior written permission.
   21  *
   22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   32  * SUCH DAMAGE.
   33  *
   34  *      @(#)kern_sig.c  8.7 (Berkeley) 4/18/94
   35  */
   36 
   37 #include <sys/cdefs.h>
   38 __FBSDID("$FreeBSD: releng/7.3/sys/kern/kern_sig.c 197745 2009-10-04 13:00:27Z kib $");
   39 
   40 #include "opt_compat.h"
   41 #include "opt_ktrace.h"
   42 
   43 #include <sys/param.h>
   44 #include <sys/systm.h>
   45 #include <sys/signalvar.h>
   46 #include <sys/vnode.h>
   47 #include <sys/acct.h>
   48 #include <sys/condvar.h>
   49 #include <sys/event.h>
   50 #include <sys/fcntl.h>
   51 #include <sys/kernel.h>
   52 #include <sys/kse.h>
   53 #include <sys/ktr.h>
   54 #include <sys/ktrace.h>
   55 #include <sys/lock.h>
   56 #include <sys/malloc.h>
   57 #include <sys/mutex.h>
   58 #include <sys/namei.h>
   59 #include <sys/proc.h>
   60 #include <sys/posix4.h>
   61 #include <sys/pioctl.h>
   62 #include <sys/resourcevar.h>
   63 #include <sys/sbuf.h>
   64 #include <sys/sleepqueue.h>
   65 #include <sys/smp.h>
   66 #include <sys/stat.h>
   67 #include <sys/sx.h>
   68 #include <sys/syscallsubr.h>
   69 #include <sys/sysctl.h>
   70 #include <sys/sysent.h>
   71 #include <sys/syslog.h>
   72 #include <sys/sysproto.h>
   73 #include <sys/timers.h>
   74 #include <sys/unistd.h>
   75 #include <sys/wait.h>
   76 #include <vm/vm.h>
   77 #include <vm/vm_extern.h>
   78 #include <vm/uma.h>
   79 
   80 #include <machine/cpu.h>
   81 
   82 #include <security/audit/audit.h>
   83 
   84 #define ONSIG   32              /* NSIG for osig* syscalls.  XXX. */
   85 
   86 static int      coredump(struct thread *);
   87 static char     *expand_name(const char *, uid_t, pid_t);
   88 static int      killpg1(struct thread *td, int sig, int pgid, int all);
   89 static int      issignal(struct thread *p);
   90 static int      sigprop(int sig);
   91 static int      tdsigwakeup(struct thread *, int, sig_t, int);
   92 static void     sig_suspend_threads(struct thread *, struct proc *, int);
   93 static int      filt_sigattach(struct knote *kn);
   94 static void     filt_sigdetach(struct knote *kn);
   95 static int      filt_signal(struct knote *kn, long hint);
   96 static struct thread *sigtd(struct proc *p, int sig, int prop);
   97 #ifdef KSE
   98 static int      do_tdsignal(struct proc *, struct thread *, int, ksiginfo_t *);
   99 #endif
  100 static void     sigqueue_start(void);
  101 
  102 static uma_zone_t       ksiginfo_zone = NULL;
  103 struct filterops sig_filtops =
  104         { 0, filt_sigattach, filt_sigdetach, filt_signal };
  105 
  106 int     kern_logsigexit = 1;
  107 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 
  108     &kern_logsigexit, 0, 
  109     "Log processes quitting on abnormal signals to syslog(3)");
  110 
  111 static int      kern_forcesigexit = 1;
  112 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW,
  113     &kern_forcesigexit, 0, "Force trap signal to be handled");
  114 
  115 SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, "POSIX real time signal");
  116 
  117 static int      max_pending_per_proc = 128;
  118 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW,
  119     &max_pending_per_proc, 0, "Max pending signals per proc");
  120 
  121 static int      preallocate_siginfo = 1024;
  122 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo);
  123 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD,
  124     &preallocate_siginfo, 0, "Preallocated signal memory size");
  125 
  126 static int      signal_overflow = 0;
  127 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD,
  128     &signal_overflow, 0, "Number of signals overflew");
  129 
  130 static int      signal_alloc_fail = 0;
  131 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD,
  132     &signal_alloc_fail, 0, "signals failed to be allocated");
  133 
  134 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL);
  135 
  136 /*
  137  * Policy -- Can ucred cr1 send SIGIO to process cr2?
  138  * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG
  139  * in the right situations.
  140  */
  141 #define CANSIGIO(cr1, cr2) \
  142         ((cr1)->cr_uid == 0 || \
  143             (cr1)->cr_ruid == (cr2)->cr_ruid || \
  144             (cr1)->cr_uid == (cr2)->cr_ruid || \
  145             (cr1)->cr_ruid == (cr2)->cr_uid || \
  146             (cr1)->cr_uid == (cr2)->cr_uid)
  147 
  148 int sugid_coredump;
  149 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 
  150     &sugid_coredump, 0, "Enable coredumping set user/group ID processes");
  151 
  152 static int      do_coredump = 1;
  153 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
  154         &do_coredump, 0, "Enable/Disable coredumps");
  155 
  156 static int      set_core_nodump_flag = 0;
  157 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag,
  158         0, "Enable setting the NODUMP flag on coredump files");
  159 
  160 /*
  161  * Signal properties and actions.
  162  * The array below categorizes the signals and their default actions
  163  * according to the following properties:
  164  */
  165 #define SA_KILL         0x01            /* terminates process by default */
  166 #define SA_CORE         0x02            /* ditto and coredumps */
  167 #define SA_STOP         0x04            /* suspend process */
  168 #define SA_TTYSTOP      0x08            /* ditto, from tty */
  169 #define SA_IGNORE       0x10            /* ignore by default */
  170 #define SA_CONT         0x20            /* continue if suspended */
  171 #define SA_CANTMASK     0x40            /* non-maskable, catchable */
  172 #define SA_PROC         0x80            /* deliverable to any thread */
  173 
  174 static int sigproptbl[NSIG] = {
  175         SA_KILL|SA_PROC,                /* SIGHUP */
  176         SA_KILL|SA_PROC,                /* SIGINT */
  177         SA_KILL|SA_CORE|SA_PROC,        /* SIGQUIT */
  178         SA_KILL|SA_CORE,                /* SIGILL */
  179         SA_KILL|SA_CORE,                /* SIGTRAP */
  180         SA_KILL|SA_CORE,                /* SIGABRT */
  181         SA_KILL|SA_CORE|SA_PROC,        /* SIGEMT */
  182         SA_KILL|SA_CORE,                /* SIGFPE */
  183         SA_KILL|SA_PROC,                /* SIGKILL */
  184         SA_KILL|SA_CORE,                /* SIGBUS */
  185         SA_KILL|SA_CORE,                /* SIGSEGV */
  186         SA_KILL|SA_CORE,                /* SIGSYS */
  187         SA_KILL|SA_PROC,                /* SIGPIPE */
  188         SA_KILL|SA_PROC,                /* SIGALRM */
  189         SA_KILL|SA_PROC,                /* SIGTERM */
  190         SA_IGNORE|SA_PROC,              /* SIGURG */
  191         SA_STOP|SA_PROC,                /* SIGSTOP */
  192         SA_STOP|SA_TTYSTOP|SA_PROC,     /* SIGTSTP */
  193         SA_IGNORE|SA_CONT|SA_PROC,      /* SIGCONT */
  194         SA_IGNORE|SA_PROC,              /* SIGCHLD */
  195         SA_STOP|SA_TTYSTOP|SA_PROC,     /* SIGTTIN */
  196         SA_STOP|SA_TTYSTOP|SA_PROC,     /* SIGTTOU */
  197         SA_IGNORE|SA_PROC,              /* SIGIO */
  198         SA_KILL,                        /* SIGXCPU */
  199         SA_KILL,                        /* SIGXFSZ */
  200         SA_KILL|SA_PROC,                /* SIGVTALRM */
  201         SA_KILL|SA_PROC,                /* SIGPROF */
  202         SA_IGNORE|SA_PROC,              /* SIGWINCH  */
  203         SA_IGNORE|SA_PROC,              /* SIGINFO */
  204         SA_KILL|SA_PROC,                /* SIGUSR1 */
  205         SA_KILL|SA_PROC,                /* SIGUSR2 */
  206 };
  207 
  208 static void
  209 sigqueue_start(void)
  210 {
  211         ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t),
  212                 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
  213         uma_prealloc(ksiginfo_zone, preallocate_siginfo);
  214         p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS);
  215         p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1);
  216         p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc);
  217 }
  218 
  219 ksiginfo_t *
  220 ksiginfo_alloc(int wait)
  221 {
  222         int flags;
  223 
  224         flags = M_ZERO;
  225         if (! wait)
  226                 flags |= M_NOWAIT;
  227         if (ksiginfo_zone != NULL)
  228                 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags));
  229         return (NULL);
  230 }
  231 
  232 void
  233 ksiginfo_free(ksiginfo_t *ksi)
  234 {
  235         uma_zfree(ksiginfo_zone, ksi);
  236 }
  237 
  238 static __inline int
  239 ksiginfo_tryfree(ksiginfo_t *ksi)
  240 {
  241         if (!(ksi->ksi_flags & KSI_EXT)) {
  242                 uma_zfree(ksiginfo_zone, ksi);
  243                 return (1);
  244         }
  245         return (0);
  246 }
  247 
  248 void
  249 sigqueue_init(sigqueue_t *list, struct proc *p)
  250 {
  251         SIGEMPTYSET(list->sq_signals);
  252         SIGEMPTYSET(list->sq_kill);
  253         TAILQ_INIT(&list->sq_list);
  254         list->sq_proc = p;
  255         list->sq_flags = SQ_INIT;
  256 }
  257 
  258 /*
  259  * Get a signal's ksiginfo.
  260  * Return:
  261  *      0       -       signal not found
  262  *      others  -       signal number
  263  */ 
  264 int
  265 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si)
  266 {
  267         struct proc *p = sq->sq_proc;
  268         struct ksiginfo *ksi, *next;
  269         int count = 0;
  270 
  271         KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
  272 
  273         if (!SIGISMEMBER(sq->sq_signals, signo))
  274                 return (0);
  275 
  276         if (SIGISMEMBER(sq->sq_kill, signo)) {
  277                 count++;
  278                 SIGDELSET(sq->sq_kill, signo);
  279         }
  280 
  281         TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
  282                 if (ksi->ksi_signo == signo) {
  283                         if (count == 0) {
  284                                 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
  285                                 ksi->ksi_sigq = NULL;
  286                                 ksiginfo_copy(ksi, si);
  287                                 if (ksiginfo_tryfree(ksi) && p != NULL)
  288                                         p->p_pendingcnt--;
  289                         }
  290                         if (++count > 1)
  291                                 break;
  292                 }
  293         }
  294 
  295         if (count <= 1)
  296                 SIGDELSET(sq->sq_signals, signo);
  297         si->ksi_signo = signo;
  298         return (signo);
  299 }
  300 
  301 void
  302 sigqueue_take(ksiginfo_t *ksi)
  303 {
  304         struct ksiginfo *kp;
  305         struct proc     *p;
  306         sigqueue_t      *sq;
  307 
  308         if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL)
  309                 return;
  310 
  311         p = sq->sq_proc;
  312         TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
  313         ksi->ksi_sigq = NULL;
  314         if (!(ksi->ksi_flags & KSI_EXT) && p != NULL)
  315                 p->p_pendingcnt--;
  316 
  317         for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL;
  318              kp = TAILQ_NEXT(kp, ksi_link)) {
  319                 if (kp->ksi_signo == ksi->ksi_signo)
  320                         break;
  321         }
  322         if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo))
  323                 SIGDELSET(sq->sq_signals, ksi->ksi_signo);
  324 }
  325 
  326 int
  327 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si)
  328 {
  329         struct proc *p = sq->sq_proc;
  330         struct ksiginfo *ksi;
  331         int ret = 0;
  332 
  333         KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
  334         
  335         if (signo == SIGKILL || signo == SIGSTOP || si == NULL) {
  336                 SIGADDSET(sq->sq_kill, signo);
  337                 goto out_set_bit;
  338         }
  339 
  340         /* directly insert the ksi, don't copy it */
  341         if (si->ksi_flags & KSI_INS) {
  342                 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link);
  343                 si->ksi_sigq = sq;
  344                 goto out_set_bit;
  345         }
  346 
  347         if (__predict_false(ksiginfo_zone == NULL)) {
  348                 SIGADDSET(sq->sq_kill, signo);
  349                 goto out_set_bit;
  350         }
  351         
  352         if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) {
  353                 signal_overflow++;
  354                 ret = EAGAIN;
  355         } else if ((ksi = ksiginfo_alloc(0)) == NULL) {
  356                 signal_alloc_fail++;
  357                 ret = EAGAIN;
  358         } else {
  359                 if (p != NULL)
  360                         p->p_pendingcnt++;
  361                 ksiginfo_copy(si, ksi);
  362                 ksi->ksi_signo = signo;
  363                 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link);
  364                 ksi->ksi_sigq = sq;
  365         }
  366 
  367         if ((si->ksi_flags & KSI_TRAP) != 0) {
  368                 if (ret != 0)
  369                         SIGADDSET(sq->sq_kill, signo);
  370                 ret = 0;
  371                 goto out_set_bit;
  372         }
  373 
  374         if (ret != 0)
  375                 return (ret);
  376         
  377 out_set_bit:
  378         SIGADDSET(sq->sq_signals, signo);
  379         return (ret);
  380 }
  381 
  382 void
  383 sigqueue_flush(sigqueue_t *sq)
  384 {
  385         struct proc *p = sq->sq_proc;
  386         ksiginfo_t *ksi;
  387 
  388         KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
  389 
  390         if (p != NULL)
  391                 PROC_LOCK_ASSERT(p, MA_OWNED);
  392 
  393         while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) {
  394                 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
  395                 ksi->ksi_sigq = NULL;
  396                 if (ksiginfo_tryfree(ksi) && p != NULL)
  397                         p->p_pendingcnt--;
  398         }
  399 
  400         SIGEMPTYSET(sq->sq_signals);
  401         SIGEMPTYSET(sq->sq_kill);
  402 }
  403 
  404 void
  405 sigqueue_collect_set(sigqueue_t *sq, sigset_t *set)
  406 {
  407         ksiginfo_t *ksi;
  408 
  409         KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
  410 
  411         TAILQ_FOREACH(ksi, &sq->sq_list, ksi_link)
  412                 SIGADDSET(*set, ksi->ksi_signo);
  413         SIGSETOR(*set, sq->sq_kill);
  414 }
  415 
  416 void
  417 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, sigset_t *setp)
  418 {
  419         sigset_t tmp, set;
  420         struct proc *p1, *p2;
  421         ksiginfo_t *ksi, *next;
  422 
  423         KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited"));
  424         KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited"));
  425         /*
  426          * make a copy, this allows setp to point to src or dst
  427          * sq_signals without trouble.
  428          */
  429         set = *setp;
  430         p1 = src->sq_proc;
  431         p2 = dst->sq_proc;
  432         /* Move siginfo to target list */
  433         TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) {
  434                 if (SIGISMEMBER(set, ksi->ksi_signo)) {
  435                         TAILQ_REMOVE(&src->sq_list, ksi, ksi_link);
  436                         if (p1 != NULL)
  437                                 p1->p_pendingcnt--;
  438                         TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link);
  439                         ksi->ksi_sigq = dst;
  440                         if (p2 != NULL)
  441                                 p2->p_pendingcnt++;
  442                 }
  443         }
  444 
  445         /* Move pending bits to target list */
  446         tmp = src->sq_kill;
  447         SIGSETAND(tmp, set);
  448         SIGSETOR(dst->sq_kill, tmp);
  449         SIGSETNAND(src->sq_kill, tmp);
  450 
  451         tmp = src->sq_signals;
  452         SIGSETAND(tmp, set);
  453         SIGSETOR(dst->sq_signals, tmp);
  454         SIGSETNAND(src->sq_signals, tmp);
  455 
  456         /* Finally, rescan src queue and set pending bits for it */
  457         sigqueue_collect_set(src, &src->sq_signals);
  458 }
  459 
  460 void
  461 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo)
  462 {
  463         sigset_t set;
  464 
  465         SIGEMPTYSET(set);
  466         SIGADDSET(set, signo);
  467         sigqueue_move_set(src, dst, &set);
  468 }
  469 
  470 void
  471 sigqueue_delete_set(sigqueue_t *sq, sigset_t *set)
  472 {
  473         struct proc *p = sq->sq_proc;
  474         ksiginfo_t *ksi, *next;
  475 
  476         KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited"));
  477 
  478         /* Remove siginfo queue */
  479         TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
  480                 if (SIGISMEMBER(*set, ksi->ksi_signo)) {
  481                         TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
  482                         ksi->ksi_sigq = NULL;
  483                         if (ksiginfo_tryfree(ksi) && p != NULL)
  484                                 p->p_pendingcnt--;
  485                 }
  486         }
  487         SIGSETNAND(sq->sq_kill, *set);
  488         SIGSETNAND(sq->sq_signals, *set);
  489         /* Finally, rescan queue and set pending bits for it */
  490         sigqueue_collect_set(sq, &sq->sq_signals);
  491 }
  492 
  493 void
  494 sigqueue_delete(sigqueue_t *sq, int signo)
  495 {
  496         sigset_t set;
  497 
  498         SIGEMPTYSET(set);
  499         SIGADDSET(set, signo);
  500         sigqueue_delete_set(sq, &set);
  501 }
  502 
  503 /* Remove a set of signals for a process */
  504 void
  505 sigqueue_delete_set_proc(struct proc *p, sigset_t *set)
  506 {
  507         sigqueue_t worklist;
  508         struct thread *td0;
  509 
  510         PROC_LOCK_ASSERT(p, MA_OWNED);
  511 
  512         sigqueue_init(&worklist, NULL);
  513         sigqueue_move_set(&p->p_sigqueue, &worklist, set);
  514 
  515         PROC_SLOCK(p);
  516         FOREACH_THREAD_IN_PROC(p, td0)
  517                 sigqueue_move_set(&td0->td_sigqueue, &worklist, set);
  518         PROC_SUNLOCK(p);
  519 
  520         sigqueue_flush(&worklist);
  521 }
  522 
  523 void
  524 sigqueue_delete_proc(struct proc *p, int signo)
  525 {
  526         sigset_t set;
  527 
  528         SIGEMPTYSET(set);
  529         SIGADDSET(set, signo);
  530         sigqueue_delete_set_proc(p, &set);
  531 }
  532 
  533 void
  534 sigqueue_delete_stopmask_proc(struct proc *p)
  535 {
  536         sigset_t set;
  537 
  538         SIGEMPTYSET(set);
  539         SIGADDSET(set, SIGSTOP);
  540         SIGADDSET(set, SIGTSTP);
  541         SIGADDSET(set, SIGTTIN);
  542         SIGADDSET(set, SIGTTOU);
  543         sigqueue_delete_set_proc(p, &set);
  544 }
  545 
  546 /*
  547  * Determine signal that should be delivered to process p, the current
  548  * process, 0 if none.  If there is a pending stop signal with default
  549  * action, the process stops in issignal().
  550  */
  551 int
  552 cursig(struct thread *td)
  553 {
  554         PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
  555         mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED);
  556         THREAD_LOCK_ASSERT(td, MA_NOTOWNED);
  557         return (SIGPENDING(td) ? issignal(td) : 0);
  558 }
  559 
  560 /*
  561  * Arrange for ast() to handle unmasked pending signals on return to user
  562  * mode.  This must be called whenever a signal is added to td_sigqueue or
  563  * unmasked in td_sigmask.
  564  */
  565 void
  566 signotify(struct thread *td)
  567 {
  568         struct proc *p;
  569 #ifdef KSE
  570         sigset_t set, saved;
  571 #else
  572         sigset_t set;
  573 #endif
  574 
  575         p = td->td_proc;
  576 
  577         PROC_LOCK_ASSERT(p, MA_OWNED);
  578 
  579         /*
  580          * If our mask changed we may have to move signal that were
  581          * previously masked by all threads to our sigqueue.
  582          */
  583         set = p->p_sigqueue.sq_signals;
  584 #ifdef KSE
  585         if (p->p_flag & P_SA)
  586                 saved = p->p_sigqueue.sq_signals;
  587 #endif
  588         SIGSETNAND(set, td->td_sigmask);
  589         if (! SIGISEMPTY(set))
  590                 sigqueue_move_set(&p->p_sigqueue, &td->td_sigqueue, &set);
  591         if (SIGPENDING(td)) {
  592                 thread_lock(td);
  593                 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING;
  594                 thread_unlock(td);
  595         }
  596 #ifdef KSE
  597         if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) {
  598                 if (!SIGSETEQ(saved, p->p_sigqueue.sq_signals)) {
  599                         /* pending set changed */
  600                         p->p_flag |= P_SIGEVENT;
  601                         wakeup(&p->p_siglist);
  602                 }
  603         }
  604 #endif
  605 }
  606 
  607 int
  608 sigonstack(size_t sp)
  609 {
  610         struct thread *td = curthread;
  611 
  612         return ((td->td_pflags & TDP_ALTSTACK) ?
  613 #if defined(COMPAT_43)
  614             ((td->td_sigstk.ss_size == 0) ?
  615                 (td->td_sigstk.ss_flags & SS_ONSTACK) :
  616                 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size))
  617 #else
  618             ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)
  619 #endif
  620             : 0);
  621 }
  622 
  623 static __inline int
  624 sigprop(int sig)
  625 {
  626 
  627         if (sig > 0 && sig < NSIG)
  628                 return (sigproptbl[_SIG_IDX(sig)]);
  629         return (0);
  630 }
  631 
  632 int
  633 sig_ffs(sigset_t *set)
  634 {
  635         int i;
  636 
  637         for (i = 0; i < _SIG_WORDS; i++)
  638                 if (set->__bits[i])
  639                         return (ffs(set->__bits[i]) + (i * 32));
  640         return (0);
  641 }
  642 
  643 /*
  644  * kern_sigaction
  645  * sigaction
  646  * freebsd4_sigaction
  647  * osigaction
  648  */
  649 int
  650 kern_sigaction(td, sig, act, oact, flags)
  651         struct thread *td;
  652         register int sig;
  653         struct sigaction *act, *oact;
  654         int flags;
  655 {
  656         struct sigacts *ps;
  657         struct proc *p = td->td_proc;
  658 
  659         if (!_SIG_VALID(sig))
  660                 return (EINVAL);
  661 
  662         PROC_LOCK(p);
  663         ps = p->p_sigacts;
  664         mtx_lock(&ps->ps_mtx);
  665         if (oact) {
  666                 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
  667                 oact->sa_flags = 0;
  668                 if (SIGISMEMBER(ps->ps_sigonstack, sig))
  669                         oact->sa_flags |= SA_ONSTACK;
  670                 if (!SIGISMEMBER(ps->ps_sigintr, sig))
  671                         oact->sa_flags |= SA_RESTART;
  672                 if (SIGISMEMBER(ps->ps_sigreset, sig))
  673                         oact->sa_flags |= SA_RESETHAND;
  674                 if (SIGISMEMBER(ps->ps_signodefer, sig))
  675                         oact->sa_flags |= SA_NODEFER;
  676                 if (SIGISMEMBER(ps->ps_siginfo, sig)) {
  677                         oact->sa_flags |= SA_SIGINFO;
  678                         oact->sa_sigaction =
  679                             (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)];
  680                 } else
  681                         oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
  682                 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP)
  683                         oact->sa_flags |= SA_NOCLDSTOP;
  684                 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT)
  685                         oact->sa_flags |= SA_NOCLDWAIT;
  686         }
  687         if (act) {
  688                 if ((sig == SIGKILL || sig == SIGSTOP) &&
  689                     act->sa_handler != SIG_DFL) {
  690                         mtx_unlock(&ps->ps_mtx);
  691                         PROC_UNLOCK(p);
  692                         return (EINVAL);
  693                 }
  694 
  695                 /*
  696                  * Change setting atomically.
  697                  */
  698 
  699                 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
  700                 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
  701                 if (act->sa_flags & SA_SIGINFO) {
  702                         ps->ps_sigact[_SIG_IDX(sig)] =
  703                             (__sighandler_t *)act->sa_sigaction;
  704                         SIGADDSET(ps->ps_siginfo, sig);
  705                 } else {
  706                         ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
  707                         SIGDELSET(ps->ps_siginfo, sig);
  708                 }
  709                 if (!(act->sa_flags & SA_RESTART))
  710                         SIGADDSET(ps->ps_sigintr, sig);
  711                 else
  712                         SIGDELSET(ps->ps_sigintr, sig);
  713                 if (act->sa_flags & SA_ONSTACK)
  714                         SIGADDSET(ps->ps_sigonstack, sig);
  715                 else
  716                         SIGDELSET(ps->ps_sigonstack, sig);
  717                 if (act->sa_flags & SA_RESETHAND)
  718                         SIGADDSET(ps->ps_sigreset, sig);
  719                 else
  720                         SIGDELSET(ps->ps_sigreset, sig);
  721                 if (act->sa_flags & SA_NODEFER)
  722                         SIGADDSET(ps->ps_signodefer, sig);
  723                 else
  724                         SIGDELSET(ps->ps_signodefer, sig);
  725                 if (sig == SIGCHLD) {
  726                         if (act->sa_flags & SA_NOCLDSTOP)
  727                                 ps->ps_flag |= PS_NOCLDSTOP;
  728                         else
  729                                 ps->ps_flag &= ~PS_NOCLDSTOP;
  730                         if (act->sa_flags & SA_NOCLDWAIT) {
  731                                 /*
  732                                  * Paranoia: since SA_NOCLDWAIT is implemented
  733                                  * by reparenting the dying child to PID 1 (and
  734                                  * trust it to reap the zombie), PID 1 itself
  735                                  * is forbidden to set SA_NOCLDWAIT.
  736                                  */
  737                                 if (p->p_pid == 1)
  738                                         ps->ps_flag &= ~PS_NOCLDWAIT;
  739                                 else
  740                                         ps->ps_flag |= PS_NOCLDWAIT;
  741                         } else
  742                                 ps->ps_flag &= ~PS_NOCLDWAIT;
  743                         if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
  744                                 ps->ps_flag |= PS_CLDSIGIGN;
  745                         else
  746                                 ps->ps_flag &= ~PS_CLDSIGIGN;
  747                 }
  748                 /*
  749                  * Set bit in ps_sigignore for signals that are set to SIG_IGN,
  750                  * and for signals set to SIG_DFL where the default is to
  751                  * ignore. However, don't put SIGCONT in ps_sigignore, as we
  752                  * have to restart the process.
  753                  */
  754                 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
  755                     (sigprop(sig) & SA_IGNORE &&
  756                      ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
  757 #ifdef KSE
  758                         if ((p->p_flag & P_SA) &&
  759                              SIGISMEMBER(p->p_sigqueue.sq_signals, sig)) {
  760                                 p->p_flag |= P_SIGEVENT;
  761                                 wakeup(&p->p_siglist);
  762                         }
  763 #endif
  764                         /* never to be seen again */
  765                         sigqueue_delete_proc(p, sig);
  766                         if (sig != SIGCONT)
  767                                 /* easier in psignal */
  768                                 SIGADDSET(ps->ps_sigignore, sig);
  769                         SIGDELSET(ps->ps_sigcatch, sig);
  770                 } else {
  771                         SIGDELSET(ps->ps_sigignore, sig);
  772                         if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
  773                                 SIGDELSET(ps->ps_sigcatch, sig);
  774                         else
  775                                 SIGADDSET(ps->ps_sigcatch, sig);
  776                 }
  777 #ifdef COMPAT_FREEBSD4
  778                 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
  779                     ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
  780                     (flags & KSA_FREEBSD4) == 0)
  781                         SIGDELSET(ps->ps_freebsd4, sig);
  782                 else
  783                         SIGADDSET(ps->ps_freebsd4, sig);
  784 #endif
  785 #ifdef COMPAT_43
  786                 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
  787                     ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
  788                     (flags & KSA_OSIGSET) == 0)
  789                         SIGDELSET(ps->ps_osigset, sig);
  790                 else
  791                         SIGADDSET(ps->ps_osigset, sig);
  792 #endif
  793         }
  794         mtx_unlock(&ps->ps_mtx);
  795         PROC_UNLOCK(p);
  796         return (0);
  797 }
  798 
  799 #ifndef _SYS_SYSPROTO_H_
  800 struct sigaction_args {
  801         int     sig;
  802         struct  sigaction *act;
  803         struct  sigaction *oact;
  804 };
  805 #endif
  806 int
  807 sigaction(td, uap)
  808         struct thread *td;
  809         register struct sigaction_args *uap;
  810 {
  811         struct sigaction act, oact;
  812         register struct sigaction *actp, *oactp;
  813         int error;
  814 
  815         actp = (uap->act != NULL) ? &act : NULL;
  816         oactp = (uap->oact != NULL) ? &oact : NULL;
  817         if (actp) {
  818                 error = copyin(uap->act, actp, sizeof(act));
  819                 if (error)
  820                         return (error);
  821         }
  822         error = kern_sigaction(td, uap->sig, actp, oactp, 0);
  823         if (oactp && !error)
  824                 error = copyout(oactp, uap->oact, sizeof(oact));
  825         return (error);
  826 }
  827 
  828 #ifdef COMPAT_FREEBSD4
  829 #ifndef _SYS_SYSPROTO_H_
  830 struct freebsd4_sigaction_args {
  831         int     sig;
  832         struct  sigaction *act;
  833         struct  sigaction *oact;
  834 };
  835 #endif
  836 int
  837 freebsd4_sigaction(td, uap)
  838         struct thread *td;
  839         register struct freebsd4_sigaction_args *uap;
  840 {
  841         struct sigaction act, oact;
  842         register struct sigaction *actp, *oactp;
  843         int error;
  844 
  845 
  846         actp = (uap->act != NULL) ? &act : NULL;
  847         oactp = (uap->oact != NULL) ? &oact : NULL;
  848         if (actp) {
  849                 error = copyin(uap->act, actp, sizeof(act));
  850                 if (error)
  851                         return (error);
  852         }
  853         error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4);
  854         if (oactp && !error)
  855                 error = copyout(oactp, uap->oact, sizeof(oact));
  856         return (error);
  857 }
  858 #endif  /* COMAPT_FREEBSD4 */
  859 
  860 #ifdef COMPAT_43        /* XXX - COMPAT_FBSD3 */
  861 #ifndef _SYS_SYSPROTO_H_
  862 struct osigaction_args {
  863         int     signum;
  864         struct  osigaction *nsa;
  865         struct  osigaction *osa;
  866 };
  867 #endif
  868 int
  869 osigaction(td, uap)
  870         struct thread *td;
  871         register struct osigaction_args *uap;
  872 {
  873         struct osigaction sa;
  874         struct sigaction nsa, osa;
  875         register struct sigaction *nsap, *osap;
  876         int error;
  877 
  878         if (uap->signum <= 0 || uap->signum >= ONSIG)
  879                 return (EINVAL);
  880 
  881         nsap = (uap->nsa != NULL) ? &nsa : NULL;
  882         osap = (uap->osa != NULL) ? &osa : NULL;
  883 
  884         if (nsap) {
  885                 error = copyin(uap->nsa, &sa, sizeof(sa));
  886                 if (error)
  887                         return (error);
  888                 nsap->sa_handler = sa.sa_handler;
  889                 nsap->sa_flags = sa.sa_flags;
  890                 OSIG2SIG(sa.sa_mask, nsap->sa_mask);
  891         }
  892         error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
  893         if (osap && !error) {
  894                 sa.sa_handler = osap->sa_handler;
  895                 sa.sa_flags = osap->sa_flags;
  896                 SIG2OSIG(osap->sa_mask, sa.sa_mask);
  897                 error = copyout(&sa, uap->osa, sizeof(sa));
  898         }
  899         return (error);
  900 }
  901 
  902 #if !defined(__i386__)
  903 /* Avoid replicating the same stub everywhere */
  904 int
  905 osigreturn(td, uap)
  906         struct thread *td;
  907         struct osigreturn_args *uap;
  908 {
  909 
  910         return (nosys(td, (struct nosys_args *)uap));
  911 }
  912 #endif
  913 #endif /* COMPAT_43 */
  914 
  915 /*
  916  * Initialize signal state for process 0;
  917  * set to ignore signals that are ignored by default.
  918  */
  919 void
  920 siginit(p)
  921         struct proc *p;
  922 {
  923         register int i;
  924         struct sigacts *ps;
  925 
  926         PROC_LOCK(p);
  927         ps = p->p_sigacts;
  928         mtx_lock(&ps->ps_mtx);
  929         for (i = 1; i <= NSIG; i++)
  930                 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
  931                         SIGADDSET(ps->ps_sigignore, i);
  932         mtx_unlock(&ps->ps_mtx);
  933         PROC_UNLOCK(p);
  934 }
  935 
  936 /*
  937  * Reset signals for an exec of the specified process.
  938  */
  939 void
  940 execsigs(struct proc *p)
  941 {
  942         struct sigacts *ps;
  943         int sig;
  944         struct thread *td;
  945 
  946         /*
  947          * Reset caught signals.  Held signals remain held
  948          * through td_sigmask (unless they were caught,
  949          * and are now ignored by default).
  950          */
  951         PROC_LOCK_ASSERT(p, MA_OWNED);
  952         td = FIRST_THREAD_IN_PROC(p);
  953         ps = p->p_sigacts;
  954         mtx_lock(&ps->ps_mtx);
  955         while (SIGNOTEMPTY(ps->ps_sigcatch)) {
  956                 sig = sig_ffs(&ps->ps_sigcatch);
  957                 SIGDELSET(ps->ps_sigcatch, sig);
  958                 if (sigprop(sig) & SA_IGNORE) {
  959                         if (sig != SIGCONT)
  960                                 SIGADDSET(ps->ps_sigignore, sig);
  961                         sigqueue_delete_proc(p, sig);
  962                 }
  963                 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
  964         }
  965         /*
  966          * Reset stack state to the user stack.
  967          * Clear set of signals caught on the signal stack.
  968          */
  969         td->td_sigstk.ss_flags = SS_DISABLE;
  970         td->td_sigstk.ss_size = 0;
  971         td->td_sigstk.ss_sp = 0;
  972         td->td_pflags &= ~TDP_ALTSTACK;
  973         /*
  974          * Reset no zombies if child dies flag as Solaris does.
  975          */
  976         ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN);
  977         if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
  978                 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL;
  979         mtx_unlock(&ps->ps_mtx);
  980 }
  981 
  982 /*
  983  * kern_sigprocmask()
  984  *
  985  *      Manipulate signal mask.
  986  */
  987 int
  988 kern_sigprocmask(td, how, set, oset, old)
  989         struct thread *td;
  990         int how;
  991         sigset_t *set, *oset;
  992         int old;
  993 {
  994         int error;
  995 
  996         PROC_LOCK(td->td_proc);
  997         if (oset != NULL)
  998                 *oset = td->td_sigmask;
  999 
 1000         error = 0;
 1001         if (set != NULL) {
 1002                 switch (how) {
 1003                 case SIG_BLOCK:
 1004                         SIG_CANTMASK(*set);
 1005                         SIGSETOR(td->td_sigmask, *set);
 1006                         break;
 1007                 case SIG_UNBLOCK:
 1008                         SIGSETNAND(td->td_sigmask, *set);
 1009                         signotify(td);
 1010                         break;
 1011                 case SIG_SETMASK:
 1012                         SIG_CANTMASK(*set);
 1013                         if (old)
 1014                                 SIGSETLO(td->td_sigmask, *set);
 1015                         else
 1016                                 td->td_sigmask = *set;
 1017                         signotify(td);
 1018                         break;
 1019                 default:
 1020                         error = EINVAL;
 1021                         break;
 1022                 }
 1023         }
 1024         PROC_UNLOCK(td->td_proc);
 1025         return (error);
 1026 }
 1027 
 1028 #ifndef _SYS_SYSPROTO_H_
 1029 struct sigprocmask_args {
 1030         int     how;
 1031         const sigset_t *set;
 1032         sigset_t *oset;
 1033 };
 1034 #endif
 1035 int
 1036 sigprocmask(td, uap)
 1037         register struct thread *td;
 1038         struct sigprocmask_args *uap;
 1039 {
 1040         sigset_t set, oset;
 1041         sigset_t *setp, *osetp;
 1042         int error;
 1043 
 1044         setp = (uap->set != NULL) ? &set : NULL;
 1045         osetp = (uap->oset != NULL) ? &oset : NULL;
 1046         if (setp) {
 1047                 error = copyin(uap->set, setp, sizeof(set));
 1048                 if (error)
 1049                         return (error);
 1050         }
 1051         error = kern_sigprocmask(td, uap->how, setp, osetp, 0);
 1052         if (osetp && !error) {
 1053                 error = copyout(osetp, uap->oset, sizeof(oset));
 1054         }
 1055         return (error);
 1056 }
 1057 
 1058 #ifdef COMPAT_43        /* XXX - COMPAT_FBSD3 */
 1059 #ifndef _SYS_SYSPROTO_H_
 1060 struct osigprocmask_args {
 1061         int     how;
 1062         osigset_t mask;
 1063 };
 1064 #endif
 1065 int
 1066 osigprocmask(td, uap)
 1067         register struct thread *td;
 1068         struct osigprocmask_args *uap;
 1069 {
 1070         sigset_t set, oset;
 1071         int error;
 1072 
 1073         OSIG2SIG(uap->mask, set);
 1074         error = kern_sigprocmask(td, uap->how, &set, &oset, 1);
 1075         SIG2OSIG(oset, td->td_retval[0]);
 1076         return (error);
 1077 }
 1078 #endif /* COMPAT_43 */
 1079 
 1080 int
 1081 sigwait(struct thread *td, struct sigwait_args *uap)
 1082 {
 1083         ksiginfo_t ksi;
 1084         sigset_t set;
 1085         int error;
 1086 
 1087         error = copyin(uap->set, &set, sizeof(set));
 1088         if (error) {
 1089                 td->td_retval[0] = error;
 1090                 return (0);
 1091         }
 1092 
 1093         error = kern_sigtimedwait(td, set, &ksi, NULL);
 1094         if (error) {
 1095                 if (error == ERESTART)
 1096                         return (error);
 1097                 td->td_retval[0] = error;
 1098                 return (0);
 1099         }
 1100 
 1101         error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo));
 1102         td->td_retval[0] = error;
 1103         return (0);
 1104 }
 1105 
 1106 int
 1107 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap)
 1108 {
 1109         struct timespec ts;
 1110         struct timespec *timeout;
 1111         sigset_t set;
 1112         ksiginfo_t ksi;
 1113         int error;
 1114 
 1115         if (uap->timeout) {
 1116                 error = copyin(uap->timeout, &ts, sizeof(ts));
 1117                 if (error)
 1118                         return (error);
 1119 
 1120                 timeout = &ts;
 1121         } else
 1122                 timeout = NULL;
 1123 
 1124         error = copyin(uap->set, &set, sizeof(set));
 1125         if (error)
 1126                 return (error);
 1127 
 1128         error = kern_sigtimedwait(td, set, &ksi, timeout);
 1129         if (error)
 1130                 return (error);
 1131 
 1132         if (uap->info)
 1133                 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t));
 1134 
 1135         if (error == 0)
 1136                 td->td_retval[0] = ksi.ksi_signo;
 1137         return (error);
 1138 }
 1139 
 1140 int
 1141 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap)
 1142 {
 1143         ksiginfo_t ksi;
 1144         sigset_t set;
 1145         int error;
 1146 
 1147         error = copyin(uap->set, &set, sizeof(set));
 1148         if (error)
 1149                 return (error);
 1150 
 1151         error = kern_sigtimedwait(td, set, &ksi, NULL);
 1152         if (error)
 1153                 return (error);
 1154 
 1155         if (uap->info)
 1156                 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t));
 1157         
 1158         if (error == 0)
 1159                 td->td_retval[0] = ksi.ksi_signo;
 1160         return (error);
 1161 }
 1162 
 1163 int
 1164 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi,
 1165         struct timespec *timeout)
 1166 {
 1167         struct sigacts *ps;
 1168         sigset_t savedmask;
 1169         struct proc *p;
 1170         int error, sig, hz, i, timevalid = 0;
 1171         struct timespec rts, ets, ts;
 1172         struct timeval tv;
 1173 
 1174         p = td->td_proc;
 1175         error = 0;
 1176         sig = 0;
 1177         ets.tv_sec = 0;
 1178         ets.tv_nsec = 0;
 1179         SIG_CANTMASK(waitset);
 1180 
 1181         PROC_LOCK(p);
 1182         ps = p->p_sigacts;
 1183         savedmask = td->td_sigmask;
 1184         if (timeout) {
 1185                 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) {
 1186                         timevalid = 1;
 1187                         getnanouptime(&rts);
 1188                         ets = rts;
 1189                         timespecadd(&ets, timeout);
 1190                 }
 1191         }
 1192 
 1193 restart:
 1194         for (i = 1; i <= _SIG_MAXSIG; ++i) {
 1195                 if (!SIGISMEMBER(waitset, i))
 1196                         continue;
 1197                 if (!SIGISMEMBER(td->td_sigqueue.sq_signals, i)) {
 1198                         if (SIGISMEMBER(p->p_sigqueue.sq_signals, i)) {
 1199 #ifdef KSE
 1200                                 if (p->p_flag & P_SA) {
 1201                                         p->p_flag |= P_SIGEVENT;
 1202                                         wakeup(&p->p_siglist);
 1203                                 }
 1204 #endif
 1205                                 sigqueue_move(&p->p_sigqueue,
 1206                                         &td->td_sigqueue, i);
 1207                         } else
 1208                                 continue;
 1209                 }
 1210 
 1211                 SIGFILLSET(td->td_sigmask);
 1212                 SIG_CANTMASK(td->td_sigmask);
 1213                 SIGDELSET(td->td_sigmask, i);
 1214                 mtx_lock(&ps->ps_mtx);
 1215                 sig = cursig(td);
 1216                 mtx_unlock(&ps->ps_mtx);
 1217                 if (sig)
 1218                         goto out;
 1219                 else {
 1220                         /*
 1221                          * Because cursig() may have stopped current thread,
 1222                          * after it is resumed, things may have already been 
 1223                          * changed, it should rescan any pending signals.
 1224                          */
 1225                         goto restart;
 1226                 }
 1227         }
 1228 
 1229         if (error)
 1230                 goto out;
 1231 
 1232         /*
 1233          * POSIX says this must be checked after looking for pending
 1234          * signals.
 1235          */
 1236         if (timeout) {
 1237                 if (!timevalid) {
 1238                         error = EINVAL;
 1239                         goto out;
 1240                 }
 1241                 getnanouptime(&rts);
 1242                 if (timespeccmp(&rts, &ets, >=)) {
 1243                         error = EAGAIN;
 1244                         goto out;
 1245                 }
 1246                 ts = ets;
 1247                 timespecsub(&ts, &rts);
 1248                 TIMESPEC_TO_TIMEVAL(&tv, &ts);
 1249                 hz = tvtohz(&tv);
 1250         } else
 1251                 hz = 0;
 1252 
 1253         td->td_sigmask = savedmask;
 1254         SIGSETNAND(td->td_sigmask, waitset);
 1255         signotify(td);
 1256         error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz);
 1257         if (timeout) {
 1258                 if (error == ERESTART) {
 1259                         /* timeout can not be restarted. */
 1260                         error = EINTR;
 1261                 } else if (error == EAGAIN) {
 1262                         /* will calculate timeout by ourself. */
 1263                         error = 0;
 1264                 }
 1265         }
 1266         goto restart;
 1267 
 1268 out:
 1269         td->td_sigmask = savedmask;
 1270         signotify(td);
 1271         if (sig) {
 1272                 ksiginfo_init(ksi);
 1273                 sigqueue_get(&td->td_sigqueue, sig, ksi);
 1274                 ksi->ksi_signo = sig;
 1275                 if (ksi->ksi_code == SI_TIMER)
 1276                         itimer_accept(p, ksi->ksi_timerid, ksi);
 1277                 error = 0;
 1278 
 1279 #ifdef KTRACE
 1280                 if (KTRPOINT(td, KTR_PSIG)) {
 1281                         sig_t action;
 1282 
 1283                         mtx_lock(&ps->ps_mtx);
 1284                         action = ps->ps_sigact[_SIG_IDX(sig)];
 1285                         mtx_unlock(&ps->ps_mtx);
 1286                         ktrpsig(sig, action, &td->td_sigmask, 0);
 1287                 }
 1288 #endif
 1289                 if (sig == SIGKILL)
 1290                         sigexit(td, sig);
 1291         }
 1292         PROC_UNLOCK(p);
 1293         return (error);
 1294 }
 1295 
 1296 #ifndef _SYS_SYSPROTO_H_
 1297 struct sigpending_args {
 1298         sigset_t        *set;
 1299 };
 1300 #endif
 1301 int
 1302 sigpending(td, uap)
 1303         struct thread *td;
 1304         struct sigpending_args *uap;
 1305 {
 1306         struct proc *p = td->td_proc;
 1307         sigset_t pending;
 1308 
 1309         PROC_LOCK(p);
 1310         pending = p->p_sigqueue.sq_signals;
 1311         SIGSETOR(pending, td->td_sigqueue.sq_signals);
 1312         PROC_UNLOCK(p);
 1313         return (copyout(&pending, uap->set, sizeof(sigset_t)));
 1314 }
 1315 
 1316 #ifdef COMPAT_43        /* XXX - COMPAT_FBSD3 */
 1317 #ifndef _SYS_SYSPROTO_H_
 1318 struct osigpending_args {
 1319         int     dummy;
 1320 };
 1321 #endif
 1322 int
 1323 osigpending(td, uap)
 1324         struct thread *td;
 1325         struct osigpending_args *uap;
 1326 {
 1327         struct proc *p = td->td_proc;
 1328         sigset_t pending;
 1329 
 1330         PROC_LOCK(p);
 1331         pending = p->p_sigqueue.sq_signals;
 1332         SIGSETOR(pending, td->td_sigqueue.sq_signals);
 1333         PROC_UNLOCK(p);
 1334         SIG2OSIG(pending, td->td_retval[0]);
 1335         return (0);
 1336 }
 1337 #endif /* COMPAT_43 */
 1338 
 1339 #if defined(COMPAT_43)
 1340 /*
 1341  * Generalized interface signal handler, 4.3-compatible.
 1342  */
 1343 #ifndef _SYS_SYSPROTO_H_
 1344 struct osigvec_args {
 1345         int     signum;
 1346         struct  sigvec *nsv;
 1347         struct  sigvec *osv;
 1348 };
 1349 #endif
 1350 /* ARGSUSED */
 1351 int
 1352 osigvec(td, uap)
 1353         struct thread *td;
 1354         register struct osigvec_args *uap;
 1355 {
 1356         struct sigvec vec;
 1357         struct sigaction nsa, osa;
 1358         register struct sigaction *nsap, *osap;
 1359         int error;
 1360 
 1361         if (uap->signum <= 0 || uap->signum >= ONSIG)
 1362                 return (EINVAL);
 1363         nsap = (uap->nsv != NULL) ? &nsa : NULL;
 1364         osap = (uap->osv != NULL) ? &osa : NULL;
 1365         if (nsap) {
 1366                 error = copyin(uap->nsv, &vec, sizeof(vec));
 1367                 if (error)
 1368                         return (error);
 1369                 nsap->sa_handler = vec.sv_handler;
 1370                 OSIG2SIG(vec.sv_mask, nsap->sa_mask);
 1371                 nsap->sa_flags = vec.sv_flags;
 1372                 nsap->sa_flags ^= SA_RESTART;   /* opposite of SV_INTERRUPT */
 1373         }
 1374         error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
 1375         if (osap && !error) {
 1376                 vec.sv_handler = osap->sa_handler;
 1377                 SIG2OSIG(osap->sa_mask, vec.sv_mask);
 1378                 vec.sv_flags = osap->sa_flags;
 1379                 vec.sv_flags &= ~SA_NOCLDWAIT;
 1380                 vec.sv_flags ^= SA_RESTART;
 1381                 error = copyout(&vec, uap->osv, sizeof(vec));
 1382         }
 1383         return (error);
 1384 }
 1385 
 1386 #ifndef _SYS_SYSPROTO_H_
 1387 struct osigblock_args {
 1388         int     mask;
 1389 };
 1390 #endif
 1391 int
 1392 osigblock(td, uap)
 1393         register struct thread *td;
 1394         struct osigblock_args *uap;
 1395 {
 1396         struct proc *p = td->td_proc;
 1397         sigset_t set;
 1398 
 1399         OSIG2SIG(uap->mask, set);
 1400         SIG_CANTMASK(set);
 1401         PROC_LOCK(p);
 1402         SIG2OSIG(td->td_sigmask, td->td_retval[0]);
 1403         SIGSETOR(td->td_sigmask, set);
 1404         PROC_UNLOCK(p);
 1405         return (0);
 1406 }
 1407 
 1408 #ifndef _SYS_SYSPROTO_H_
 1409 struct osigsetmask_args {
 1410         int     mask;
 1411 };
 1412 #endif
 1413 int
 1414 osigsetmask(td, uap)
 1415         struct thread *td;
 1416         struct osigsetmask_args *uap;
 1417 {
 1418         struct proc *p = td->td_proc;
 1419         sigset_t set;
 1420 
 1421         OSIG2SIG(uap->mask, set);
 1422         SIG_CANTMASK(set);
 1423         PROC_LOCK(p);
 1424         SIG2OSIG(td->td_sigmask, td->td_retval[0]);
 1425         SIGSETLO(td->td_sigmask, set);
 1426         signotify(td);
 1427         PROC_UNLOCK(p);
 1428         return (0);
 1429 }
 1430 #endif /* COMPAT_43 */
 1431 
 1432 /*
 1433  * Suspend calling thread until signal, providing mask to be set in the
 1434  * meantime. 
 1435  */
 1436 #ifndef _SYS_SYSPROTO_H_
 1437 struct sigsuspend_args {
 1438         const sigset_t *sigmask;
 1439 };
 1440 #endif
 1441 /* ARGSUSED */
 1442 int
 1443 sigsuspend(td, uap)
 1444         struct thread *td;
 1445         struct sigsuspend_args *uap;
 1446 {
 1447         sigset_t mask;
 1448         int error;
 1449 
 1450         error = copyin(uap->sigmask, &mask, sizeof(mask));
 1451         if (error)
 1452                 return (error);
 1453         return (kern_sigsuspend(td, mask));
 1454 }
 1455 
 1456 int
 1457 kern_sigsuspend(struct thread *td, sigset_t mask)
 1458 {
 1459         struct proc *p = td->td_proc;
 1460 
 1461         /*
 1462          * When returning from sigsuspend, we want
 1463          * the old mask to be restored after the
 1464          * signal handler has finished.  Thus, we
 1465          * save it here and mark the sigacts structure
 1466          * to indicate this.
 1467          */
 1468         PROC_LOCK(p);
 1469         td->td_oldsigmask = td->td_sigmask;
 1470         td->td_pflags |= TDP_OLDMASK;
 1471         SIG_CANTMASK(mask);
 1472         td->td_sigmask = mask;
 1473         signotify(td);
 1474         while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0)
 1475                 /* void */;
 1476         PROC_UNLOCK(p);
 1477         /* always return EINTR rather than ERESTART... */
 1478         return (EINTR);
 1479 }
 1480 
 1481 #ifdef COMPAT_43        /* XXX - COMPAT_FBSD3 */
 1482 /*
 1483  * Compatibility sigsuspend call for old binaries.  Note nonstandard calling
 1484  * convention: libc stub passes mask, not pointer, to save a copyin.
 1485  */
 1486 #ifndef _SYS_SYSPROTO_H_
 1487 struct osigsuspend_args {
 1488         osigset_t mask;
 1489 };
 1490 #endif
 1491 /* ARGSUSED */
 1492 int
 1493 osigsuspend(td, uap)
 1494         struct thread *td;
 1495         struct osigsuspend_args *uap;
 1496 {
 1497         struct proc *p = td->td_proc;
 1498         sigset_t mask;
 1499 
 1500         PROC_LOCK(p);
 1501         td->td_oldsigmask = td->td_sigmask;
 1502         td->td_pflags |= TDP_OLDMASK;
 1503         OSIG2SIG(uap->mask, mask);
 1504         SIG_CANTMASK(mask);
 1505         SIGSETLO(td->td_sigmask, mask);
 1506         signotify(td);
 1507         while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0)
 1508                 /* void */;
 1509         PROC_UNLOCK(p);
 1510         /* always return EINTR rather than ERESTART... */
 1511         return (EINTR);
 1512 }
 1513 #endif /* COMPAT_43 */
 1514 
 1515 #if defined(COMPAT_43)
 1516 #ifndef _SYS_SYSPROTO_H_
 1517 struct osigstack_args {
 1518         struct  sigstack *nss;
 1519         struct  sigstack *oss;
 1520 };
 1521 #endif
 1522 /* ARGSUSED */
 1523 int
 1524 osigstack(td, uap)
 1525         struct thread *td;
 1526         register struct osigstack_args *uap;
 1527 {
 1528         struct sigstack nss, oss;
 1529         int error = 0;
 1530 
 1531         if (uap->nss != NULL) {
 1532                 error = copyin(uap->nss, &nss, sizeof(nss));
 1533                 if (error)
 1534                         return (error);
 1535         }
 1536         oss.ss_sp = td->td_sigstk.ss_sp;
 1537         oss.ss_onstack = sigonstack(cpu_getstack(td));
 1538         if (uap->nss != NULL) {
 1539                 td->td_sigstk.ss_sp = nss.ss_sp;
 1540                 td->td_sigstk.ss_size = 0;
 1541                 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK;
 1542                 td->td_pflags |= TDP_ALTSTACK;
 1543         }
 1544         if (uap->oss != NULL)
 1545                 error = copyout(&oss, uap->oss, sizeof(oss));
 1546 
 1547         return (error);
 1548 }
 1549 #endif /* COMPAT_43 */
 1550 
 1551 #ifndef _SYS_SYSPROTO_H_
 1552 struct sigaltstack_args {
 1553         stack_t *ss;
 1554         stack_t *oss;
 1555 };
 1556 #endif
 1557 /* ARGSUSED */
 1558 int
 1559 sigaltstack(td, uap)
 1560         struct thread *td;
 1561         register struct sigaltstack_args *uap;
 1562 {
 1563         stack_t ss, oss;
 1564         int error;
 1565 
 1566         if (uap->ss != NULL) {
 1567                 error = copyin(uap->ss, &ss, sizeof(ss));
 1568                 if (error)
 1569                         return (error);
 1570         }
 1571         error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL,
 1572             (uap->oss != NULL) ? &oss : NULL);
 1573         if (error)
 1574                 return (error);
 1575         if (uap->oss != NULL)
 1576                 error = copyout(&oss, uap->oss, sizeof(stack_t));
 1577         return (error);
 1578 }
 1579 
 1580 int
 1581 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss)
 1582 {
 1583         struct proc *p = td->td_proc;
 1584         int oonstack;
 1585 
 1586         oonstack = sigonstack(cpu_getstack(td));
 1587 
 1588         if (oss != NULL) {
 1589                 *oss = td->td_sigstk;
 1590                 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK)
 1591                     ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
 1592         }
 1593 
 1594         if (ss != NULL) {
 1595                 if (oonstack)
 1596                         return (EPERM);
 1597                 if ((ss->ss_flags & ~SS_DISABLE) != 0)
 1598                         return (EINVAL);
 1599                 if (!(ss->ss_flags & SS_DISABLE)) {
 1600                         if (ss->ss_size < p->p_sysent->sv_minsigstksz)
 1601                                 return (ENOMEM);
 1602 
 1603                         td->td_sigstk = *ss;
 1604                         td->td_pflags |= TDP_ALTSTACK;
 1605                 } else {
 1606                         td->td_pflags &= ~TDP_ALTSTACK;
 1607                 }
 1608         }
 1609         return (0);
 1610 }
 1611 
 1612 /*
 1613  * Common code for kill process group/broadcast kill.
 1614  * cp is calling process.
 1615  */
 1616 static int
 1617 killpg1(td, sig, pgid, all)
 1618         register struct thread *td;
 1619         int sig, pgid, all;
 1620 {
 1621         register struct proc *p;
 1622         struct pgrp *pgrp;
 1623         int nfound = 0;
 1624 
 1625         if (all) {
 1626                 /*
 1627                  * broadcast
 1628                  */
 1629                 sx_slock(&allproc_lock);
 1630                 FOREACH_PROC_IN_SYSTEM(p) {
 1631                         PROC_LOCK(p);
 1632                         if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
 1633                             p == td->td_proc || p->p_state == PRS_NEW) {
 1634                                 PROC_UNLOCK(p);
 1635                                 continue;
 1636                         }
 1637                         if (p_cansignal(td, p, sig) == 0) {
 1638                                 nfound++;
 1639                                 if (sig)
 1640                                         psignal(p, sig);
 1641                         }
 1642                         PROC_UNLOCK(p);
 1643                 }
 1644                 sx_sunlock(&allproc_lock);
 1645         } else {
 1646                 sx_slock(&proctree_lock);
 1647                 if (pgid == 0) {
 1648                         /*
 1649                          * zero pgid means send to my process group.
 1650                          */
 1651                         pgrp = td->td_proc->p_pgrp;
 1652                         PGRP_LOCK(pgrp);
 1653                 } else {
 1654                         pgrp = pgfind(pgid);
 1655                         if (pgrp == NULL) {
 1656                                 sx_sunlock(&proctree_lock);
 1657                                 return (ESRCH);
 1658                         }
 1659                 }
 1660                 sx_sunlock(&proctree_lock);
 1661                 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
 1662                         PROC_LOCK(p);         
 1663                         if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
 1664                                 p->p_state == PRS_NEW ) {
 1665                                 PROC_UNLOCK(p);
 1666                                 continue;
 1667                         }
 1668                         if (p_cansignal(td, p, sig) == 0) {
 1669                                 nfound++;
 1670                                 if (sig)
 1671                                         psignal(p, sig);
 1672                         }
 1673                         PROC_UNLOCK(p);
 1674                 }
 1675                 PGRP_UNLOCK(pgrp);
 1676         }
 1677         return (nfound ? 0 : ESRCH);
 1678 }
 1679 
 1680 #ifndef _SYS_SYSPROTO_H_
 1681 struct kill_args {
 1682         int     pid;
 1683         int     signum;
 1684 };
 1685 #endif
 1686 /* ARGSUSED */
 1687 int
 1688 kill(td, uap)
 1689         register struct thread *td;
 1690         register struct kill_args *uap;
 1691 {
 1692         register struct proc *p;
 1693         int error;
 1694 
 1695         AUDIT_ARG(signum, uap->signum);
 1696         AUDIT_ARG(pid, uap->pid);
 1697         if ((u_int)uap->signum > _SIG_MAXSIG)
 1698                 return (EINVAL);
 1699 
 1700         if (uap->pid > 0) {
 1701                 /* kill single process */
 1702                 if ((p = pfind(uap->pid)) == NULL) {
 1703                         if ((p = zpfind(uap->pid)) == NULL)
 1704                                 return (ESRCH);
 1705                 }
 1706                 AUDIT_ARG(process, p);
 1707                 error = p_cansignal(td, p, uap->signum);
 1708                 if (error == 0 && uap->signum)
 1709                         psignal(p, uap->signum);
 1710                 PROC_UNLOCK(p);
 1711                 return (error);
 1712         }
 1713         switch (uap->pid) {
 1714         case -1:                /* broadcast signal */
 1715                 return (killpg1(td, uap->signum, 0, 1));
 1716         case 0:                 /* signal own process group */
 1717                 return (killpg1(td, uap->signum, 0, 0));
 1718         default:                /* negative explicit process group */
 1719                 return (killpg1(td, uap->signum, -uap->pid, 0));
 1720         }
 1721         /* NOTREACHED */
 1722 }
 1723 
 1724 #if defined(COMPAT_43)
 1725 #ifndef _SYS_SYSPROTO_H_
 1726 struct okillpg_args {
 1727         int     pgid;
 1728         int     signum;
 1729 };
 1730 #endif
 1731 /* ARGSUSED */
 1732 int
 1733 okillpg(td, uap)
 1734         struct thread *td;
 1735         register struct okillpg_args *uap;
 1736 {
 1737 
 1738         AUDIT_ARG(signum, uap->signum);
 1739         AUDIT_ARG(pid, uap->pgid);
 1740         if ((u_int)uap->signum > _SIG_MAXSIG)
 1741                 return (EINVAL);
 1742 
 1743         return (killpg1(td, uap->signum, uap->pgid, 0));
 1744 }
 1745 #endif /* COMPAT_43 */
 1746 
 1747 #ifndef _SYS_SYSPROTO_H_
 1748 struct sigqueue_args {
 1749         pid_t pid;
 1750         int signum;
 1751         /* union sigval */ void *value;
 1752 };
 1753 #endif
 1754 int
 1755 sigqueue(struct thread *td, struct sigqueue_args *uap)
 1756 {
 1757         ksiginfo_t ksi;
 1758         struct proc *p;
 1759         int error;
 1760 
 1761         if ((u_int)uap->signum > _SIG_MAXSIG)
 1762                 return (EINVAL);
 1763 
 1764         /*
 1765          * Specification says sigqueue can only send signal to
 1766          * single process.
 1767          */
 1768         if (uap->pid <= 0)
 1769                 return (EINVAL);
 1770 
 1771         if ((p = pfind(uap->pid)) == NULL) {
 1772                 if ((p = zpfind(uap->pid)) == NULL)
 1773                         return (ESRCH);
 1774         }
 1775         error = p_cansignal(td, p, uap->signum);
 1776         if (error == 0 && uap->signum != 0) {
 1777                 ksiginfo_init(&ksi);
 1778                 ksi.ksi_signo = uap->signum;
 1779                 ksi.ksi_code = SI_QUEUE;
 1780                 ksi.ksi_pid = td->td_proc->p_pid;
 1781                 ksi.ksi_uid = td->td_ucred->cr_ruid;
 1782                 ksi.ksi_value.sival_ptr = uap->value;
 1783                 error = tdsignal(p, NULL, ksi.ksi_signo, &ksi);
 1784         }
 1785         PROC_UNLOCK(p);
 1786         return (error);
 1787 }
 1788 
 1789 /*
 1790  * Send a signal to a process group.
 1791  */
 1792 void
 1793 gsignal(pgid, sig)
 1794         int pgid, sig;
 1795 {
 1796         struct pgrp *pgrp;
 1797 
 1798         if (pgid != 0) {
 1799                 sx_slock(&proctree_lock);
 1800                 pgrp = pgfind(pgid);
 1801                 sx_sunlock(&proctree_lock);
 1802                 if (pgrp != NULL) {
 1803                         pgsignal(pgrp, sig, 0);
 1804                         PGRP_UNLOCK(pgrp);
 1805                 }
 1806         }
 1807 }
 1808 
 1809 /*
 1810  * Send a signal to a process group.  If checktty is 1,
 1811  * limit to members which have a controlling terminal.
 1812  */
 1813 void
 1814 pgsignal(pgrp, sig, checkctty)
 1815         struct pgrp *pgrp;
 1816         int sig, checkctty;
 1817 {
 1818         register struct proc *p;
 1819 
 1820         if (pgrp) {
 1821                 PGRP_LOCK_ASSERT(pgrp, MA_OWNED);
 1822                 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
 1823                         PROC_LOCK(p);
 1824                         if (checkctty == 0 || p->p_flag & P_CONTROLT)
 1825                                 psignal(p, sig);
 1826                         PROC_UNLOCK(p);
 1827                 }
 1828         }
 1829 }
 1830 
 1831 /*
 1832  * Send a signal caused by a trap to the current thread.  If it will be
 1833  * caught immediately, deliver it with correct code.  Otherwise, post it
 1834  * normally.
 1835  */
 1836 void
 1837 trapsignal(struct thread *td, ksiginfo_t *ksi)
 1838 {
 1839         struct sigacts *ps;
 1840         struct proc *p;
 1841 #ifdef KSE
 1842         int error;
 1843 #endif
 1844         int sig;
 1845         int code;
 1846 
 1847         p = td->td_proc;
 1848         sig = ksi->ksi_signo;
 1849         code = ksi->ksi_code;
 1850         KASSERT(_SIG_VALID(sig), ("invalid signal"));
 1851 
 1852 #ifdef KSE
 1853         if (td->td_pflags & TDP_SA) {
 1854                 if (td->td_mailbox == NULL)
 1855                         thread_user_enter(td);
 1856                 PROC_LOCK(p);
 1857                 SIGDELSET(td->td_sigmask, sig);
 1858                 thread_lock(td);
 1859                 /*
 1860                  * Force scheduling an upcall, so UTS has chance to
 1861                  * process the signal before thread runs again in
 1862                  * userland.
 1863                  */
 1864                 if (td->td_upcall)
 1865                         td->td_upcall->ku_flags |= KUF_DOUPCALL;
 1866                 thread_unlock(td);
 1867         } else {
 1868                 PROC_LOCK(p);
 1869         }
 1870 #else
 1871         PROC_LOCK(p);
 1872 #endif
 1873         ps = p->p_sigacts;
 1874         mtx_lock(&ps->ps_mtx);
 1875         if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) &&
 1876             !SIGISMEMBER(td->td_sigmask, sig)) {
 1877                 td->td_ru.ru_nsignals++;
 1878 #ifdef KTRACE
 1879                 if (KTRPOINT(curthread, KTR_PSIG))
 1880                         ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)],
 1881                             &td->td_sigmask, code);
 1882 #endif
 1883 #ifdef KSE
 1884                 if (!(td->td_pflags & TDP_SA))
 1885                         (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 
 1886                                 ksi, &td->td_sigmask);
 1887 #else
 1888                 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 
 1889                                 ksi, &td->td_sigmask);
 1890 #endif
 1891 #ifdef KSE
 1892                 else if (td->td_mailbox == NULL) {
 1893                         mtx_unlock(&ps->ps_mtx);
 1894                         /* UTS caused a sync signal */
 1895                         p->p_code = code;       /* XXX for core dump/debugger */
 1896                         p->p_sig = sig;         /* XXX to verify code */
 1897                         sigexit(td, sig);
 1898                 } else {
 1899                         mtx_unlock(&ps->ps_mtx);
 1900                         SIGADDSET(td->td_sigmask, sig);
 1901                         PROC_UNLOCK(p);
 1902                         error = copyout(&ksi->ksi_info, &td->td_mailbox->tm_syncsig,
 1903                             sizeof(siginfo_t));
 1904                         PROC_LOCK(p);
 1905                         /* UTS memory corrupted */
 1906                         if (error)
 1907                                 sigexit(td, SIGSEGV);
 1908                         mtx_lock(&ps->ps_mtx);
 1909                 }
 1910 #endif
 1911                 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
 1912                 if (!SIGISMEMBER(ps->ps_signodefer, sig))
 1913                         SIGADDSET(td->td_sigmask, sig);
 1914                 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
 1915                         /*
 1916                          * See kern_sigaction() for origin of this code.
 1917                          */
 1918                         SIGDELSET(ps->ps_sigcatch, sig);
 1919                         if (sig != SIGCONT &&
 1920                             sigprop(sig) & SA_IGNORE)
 1921                                 SIGADDSET(ps->ps_sigignore, sig);
 1922                         ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
 1923                 }
 1924                 mtx_unlock(&ps->ps_mtx);
 1925         } else {
 1926                 /*
 1927                  * Avoid a possible infinite loop if the thread
 1928                  * masking the signal or process is ignoring the
 1929                  * signal.
 1930                  */
 1931                 if (kern_forcesigexit &&
 1932                     (SIGISMEMBER(td->td_sigmask, sig) ||
 1933                      ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) {
 1934                         SIGDELSET(td->td_sigmask, sig);
 1935                         SIGDELSET(ps->ps_sigcatch, sig);
 1936                         SIGDELSET(ps->ps_sigignore, sig);
 1937                         ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
 1938                 }
 1939                 mtx_unlock(&ps->ps_mtx);
 1940                 p->p_code = code;       /* XXX for core dump/debugger */
 1941                 p->p_sig = sig;         /* XXX to verify code */
 1942                 tdsignal(p, td, sig, ksi);
 1943         }
 1944         PROC_UNLOCK(p);
 1945 }
 1946 
 1947 static struct thread *
 1948 sigtd(struct proc *p, int sig, int prop)
 1949 {
 1950         struct thread *td, *signal_td;
 1951 
 1952         PROC_LOCK_ASSERT(p, MA_OWNED);
 1953 
 1954         /*
 1955          * Check if current thread can handle the signal without
 1956          * switching context to another thread.
 1957          */
 1958         if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig))
 1959                 return (curthread);
 1960         signal_td = NULL;
 1961         PROC_SLOCK(p);
 1962         FOREACH_THREAD_IN_PROC(p, td) {
 1963                 if (!SIGISMEMBER(td->td_sigmask, sig)) {
 1964                         signal_td = td;
 1965                         break;
 1966                 }
 1967         }
 1968         if (signal_td == NULL)
 1969                 signal_td = FIRST_THREAD_IN_PROC(p);
 1970         PROC_SUNLOCK(p);
 1971         return (signal_td);
 1972 }
 1973 
 1974 /*
 1975  * Send the signal to the process.  If the signal has an action, the action
 1976  * is usually performed by the target process rather than the caller; we add
 1977  * the signal to the set of pending signals for the process.
 1978  *
 1979  * Exceptions:
 1980  *   o When a stop signal is sent to a sleeping process that takes the
 1981  *     default action, the process is stopped without awakening it.
 1982  *   o SIGCONT restarts stopped processes (or puts them back to sleep)
 1983  *     regardless of the signal action (eg, blocked or ignored).
 1984  *
 1985  * Other ignored signals are discarded immediately.
 1986  * 
 1987  * NB: This function may be entered from the debugger via the "kill" DDB
 1988  * command.  There is little that can be done to mitigate the possibly messy
 1989  * side effects of this unwise possibility.
 1990  */
 1991 void
 1992 psignal(struct proc *p, int sig)
 1993 {
 1994         (void) tdsignal(p, NULL, sig, NULL);
 1995 }
 1996 
 1997 int
 1998 psignal_event(struct proc *p, struct sigevent *sigev, ksiginfo_t *ksi)
 1999 {
 2000         struct thread *td = NULL;
 2001 
 2002         PROC_LOCK_ASSERT(p, MA_OWNED);
 2003 
 2004         KASSERT(!KSI_ONQ(ksi), ("psignal_event: ksi on queue"));
 2005 
 2006         /*
 2007          * ksi_code and other fields should be set before
 2008          * calling this function.
 2009          */
 2010         ksi->ksi_signo = sigev->sigev_signo;
 2011         ksi->ksi_value = sigev->sigev_value;
 2012         if (sigev->sigev_notify == SIGEV_THREAD_ID) {
 2013                 td = thread_find(p, sigev->sigev_notify_thread_id);
 2014                 if (td == NULL)
 2015                         return (ESRCH);
 2016         }
 2017         return (tdsignal(p, td, ksi->ksi_signo, ksi));
 2018 }
 2019 
 2020 int
 2021 tdsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi)
 2022 {
 2023 #ifdef KSE
 2024         sigset_t saved;
 2025         int ret;
 2026 
 2027         if (p->p_flag & P_SA)
 2028                 saved = p->p_sigqueue.sq_signals;
 2029         ret = do_tdsignal(p, td, sig, ksi);
 2030         if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) {
 2031                 if (!SIGSETEQ(saved, p->p_sigqueue.sq_signals)) {
 2032                         /* pending set changed */
 2033                         p->p_flag |= P_SIGEVENT;
 2034                         wakeup(&p->p_siglist);
 2035                 }
 2036         }
 2037         return (ret);
 2038 }
 2039 
 2040 static int
 2041 do_tdsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi)
 2042 {
 2043 #endif
 2044         sig_t action;
 2045         sigqueue_t *sigqueue;
 2046         int prop;
 2047         struct sigacts *ps;
 2048         int intrval;
 2049         int ret = 0;
 2050         int wakeup_swapper;
 2051 
 2052         PROC_LOCK_ASSERT(p, MA_OWNED);
 2053 
 2054         if (!_SIG_VALID(sig))
 2055 #ifdef KSE
 2056                 panic("do_tdsignal(): invalid signal %d", sig);
 2057 #else
 2058                 panic("tdsignal(): invalid signal %d", sig);
 2059 #endif
 2060 
 2061 #ifdef KSE
 2062         KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("do_tdsignal: ksi on queue"));
 2063 #else
 2064         KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("tdsignal: ksi on queue"));
 2065 #endif
 2066 
 2067         /*
 2068          * IEEE Std 1003.1-2001: return success when killing a zombie.
 2069          */
 2070         if (p->p_state == PRS_ZOMBIE) {
 2071                 if (ksi && (ksi->ksi_flags & KSI_INS))
 2072                         ksiginfo_tryfree(ksi);
 2073                 return (ret);
 2074         }
 2075 
 2076         ps = p->p_sigacts;
 2077         KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig);
 2078         prop = sigprop(sig);
 2079 
 2080         /*
 2081          * If the signal is blocked and not destined for this thread, then
 2082          * assign it to the process so that we can find it later in the first
 2083          * thread that unblocks it.  Otherwise, assign it to this thread now.
 2084          */
 2085         if (td == NULL) {
 2086                 td = sigtd(p, sig, prop);
 2087                 if (SIGISMEMBER(td->td_sigmask, sig))
 2088                         sigqueue = &p->p_sigqueue;
 2089                 else
 2090                         sigqueue = &td->td_sigqueue;
 2091         } else {
 2092                 KASSERT(td->td_proc == p, ("invalid thread"));
 2093                 sigqueue = &td->td_sigqueue;
 2094         }
 2095 
 2096         /*
 2097          * If the signal is being ignored,
 2098          * then we forget about it immediately.
 2099          * (Note: we don't set SIGCONT in ps_sigignore,
 2100          * and if it is set to SIG_IGN,
 2101          * action will be SIG_DFL here.)
 2102          */
 2103         mtx_lock(&ps->ps_mtx);
 2104         if (SIGISMEMBER(ps->ps_sigignore, sig)) {
 2105                 mtx_unlock(&ps->ps_mtx);
 2106                 if (ksi && (ksi->ksi_flags & KSI_INS))
 2107                         ksiginfo_tryfree(ksi);
 2108                 return (ret);
 2109         }
 2110         if (SIGISMEMBER(td->td_sigmask, sig))
 2111                 action = SIG_HOLD;
 2112         else if (SIGISMEMBER(ps->ps_sigcatch, sig))
 2113                 action = SIG_CATCH;
 2114         else
 2115                 action = SIG_DFL;
 2116         if (SIGISMEMBER(ps->ps_sigintr, sig))
 2117                 intrval = EINTR;
 2118         else
 2119                 intrval = ERESTART;
 2120         mtx_unlock(&ps->ps_mtx);
 2121 
 2122         if (prop & SA_CONT)
 2123                 sigqueue_delete_stopmask_proc(p);
 2124         else if (prop & SA_STOP) {
 2125                 /*
 2126                  * If sending a tty stop signal to a member of an orphaned
 2127                  * process group, discard the signal here if the action
 2128                  * is default; don't stop the process below if sleeping,
 2129                  * and don't clear any pending SIGCONT.
 2130                  */
 2131                 if ((prop & SA_TTYSTOP) &&
 2132                     (p->p_pgrp->pg_jobc == 0) &&
 2133                     (action == SIG_DFL)) {
 2134                         if (ksi && (ksi->ksi_flags & KSI_INS))
 2135                                 ksiginfo_tryfree(ksi);
 2136                         return (ret);
 2137                 }
 2138                 sigqueue_delete_proc(p, SIGCONT);
 2139                 if (p->p_flag & P_CONTINUED) {
 2140                         p->p_flag &= ~P_CONTINUED;
 2141                         PROC_LOCK(p->p_pptr);
 2142                         sigqueue_take(p->p_ksi);
 2143                         PROC_UNLOCK(p->p_pptr);
 2144                 }
 2145         }
 2146 
 2147         ret = sigqueue_add(sigqueue, sig, ksi);
 2148         if (ret != 0)
 2149                 return (ret);
 2150         signotify(td);
 2151         /*
 2152          * Defer further processing for signals which are held,
 2153          * except that stopped processes must be continued by SIGCONT.
 2154          */
 2155         if (action == SIG_HOLD &&
 2156             !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG)))
 2157                 return (ret);
 2158         /*
 2159          * SIGKILL: Remove procfs STOPEVENTs.
 2160          */
 2161         if (sig == SIGKILL) {
 2162                 /* from procfs_ioctl.c: PIOCBIC */
 2163                 p->p_stops = 0;
 2164                 /* from procfs_ioctl.c: PIOCCONT */
 2165                 p->p_step = 0;
 2166                 wakeup(&p->p_step);
 2167         }
 2168         /*
 2169          * Some signals have a process-wide effect and a per-thread
 2170          * component.  Most processing occurs when the process next
 2171          * tries to cross the user boundary, however there are some
 2172          * times when processing needs to be done immediatly, such as
 2173          * waking up threads so that they can cross the user boundary.
 2174          * We try do the per-process part here.
 2175          */
 2176         PROC_SLOCK(p);
 2177         if (P_SHOULDSTOP(p)) {
 2178                 /*
 2179                  * The process is in stopped mode. All the threads should be
 2180                  * either winding down or already on the suspended queue.
 2181                  */
 2182                 if (p->p_flag & P_TRACED) {
 2183                         /*
 2184                          * The traced process is already stopped,
 2185                          * so no further action is necessary.
 2186                          * No signal can restart us.
 2187                          */
 2188                         PROC_SUNLOCK(p);
 2189                         goto out;
 2190                 }
 2191 
 2192                 if (sig == SIGKILL) {
 2193                         /*
 2194                          * SIGKILL sets process running.
 2195                          * It will die elsewhere.
 2196                          * All threads must be restarted.
 2197                          */
 2198                         p->p_flag &= ~P_STOPPED_SIG;
 2199                         goto runfast;
 2200                 }
 2201 
 2202                 if (prop & SA_CONT) {
 2203                         /*
 2204                          * If SIGCONT is default (or ignored), we continue the
 2205                          * process but don't leave the signal in sigqueue as
 2206                          * it has no further action.  If SIGCONT is held, we
 2207                          * continue the process and leave the signal in
 2208                          * sigqueue.  If the process catches SIGCONT, let it
 2209                          * handle the signal itself.  If it isn't waiting on
 2210                          * an event, it goes back to run state.
 2211                          * Otherwise, process goes back to sleep state.
 2212                          */
 2213                         p->p_flag &= ~P_STOPPED_SIG;
 2214                         if (p->p_numthreads == p->p_suspcount) {
 2215                                 PROC_SUNLOCK(p);
 2216                                 p->p_flag |= P_CONTINUED;
 2217                                 p->p_xstat = SIGCONT;
 2218                                 PROC_LOCK(p->p_pptr);
 2219                                 childproc_continued(p);
 2220                                 PROC_UNLOCK(p->p_pptr);
 2221                                 PROC_SLOCK(p);
 2222                         }
 2223                         if (action == SIG_DFL) {
 2224                                 thread_unsuspend(p);
 2225                                 PROC_SUNLOCK(p);
 2226                                 sigqueue_delete(sigqueue, sig);
 2227                                 goto out;
 2228                         }
 2229                         if (action == SIG_CATCH) {
 2230 #ifdef KSE
 2231                                 /*
 2232                                  * The process wants to catch it so it needs
 2233                                  * to run at least one thread, but which one?
 2234                                  * It would seem that the answer would be to
 2235                                  * run an upcall in the next KSE to run, and
 2236                                  * deliver the signal that way. In a NON KSE
 2237                                  * process, we need to make sure that the
 2238                                  * single thread is runnable asap.
 2239                                  * XXXKSE for now however, make them all run.
 2240                                  */
 2241 #endif
 2242                                 /*
 2243                                  * The process wants to catch it so it needs
 2244                                  * to run at least one thread, but which one?
 2245                                  */
 2246                                 goto runfast;
 2247                         }
 2248                         /*
 2249                          * The signal is not ignored or caught.
 2250                          */
 2251                         thread_unsuspend(p);
 2252                         PROC_SUNLOCK(p);
 2253                         goto out;
 2254                 }
 2255 
 2256                 if (prop & SA_STOP) {
 2257                         /*
 2258                          * Already stopped, don't need to stop again
 2259                          * (If we did the shell could get confused).
 2260                          * Just make sure the signal STOP bit set.
 2261                          */
 2262                         PROC_SUNLOCK(p);
 2263                         p->p_flag |= P_STOPPED_SIG;
 2264                         sigqueue_delete(sigqueue, sig);
 2265                         goto out;
 2266                 }
 2267 
 2268                 /*
 2269                  * All other kinds of signals:
 2270                  * If a thread is sleeping interruptibly, simulate a
 2271                  * wakeup so that when it is continued it will be made
 2272                  * runnable and can look at the signal.  However, don't make
 2273                  * the PROCESS runnable, leave it stopped.
 2274                  * It may run a bit until it hits a thread_suspend_check().
 2275                  */
 2276                 wakeup_swapper = 0;
 2277                 thread_lock(td);
 2278                 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR))
 2279                         wakeup_swapper = sleepq_abort(td, intrval);
 2280                 thread_unlock(td);
 2281                 PROC_SUNLOCK(p);
 2282                 if (wakeup_swapper)
 2283                         kick_proc0();
 2284                 goto out;
 2285                 /*
 2286                  * Mutexes are short lived. Threads waiting on them will
 2287                  * hit thread_suspend_check() soon.
 2288                  */
 2289         } else if (p->p_state == PRS_NORMAL) {
 2290                 if (p->p_flag & P_TRACED || action == SIG_CATCH) {
 2291                         thread_lock(td);
 2292                         wakeup_swapper = tdsigwakeup(td, sig, action, intrval);
 2293                         thread_unlock(td);
 2294                         PROC_SUNLOCK(p);
 2295                         if (wakeup_swapper)
 2296                                 kick_proc0();
 2297                         goto out;
 2298                 }
 2299 
 2300                 MPASS(action == SIG_DFL);
 2301 
 2302                 if (prop & SA_STOP) {
 2303                         if (p->p_flag & P_PPWAIT) {
 2304                                 PROC_SUNLOCK(p);
 2305                                 goto out;
 2306                         }
 2307                         p->p_flag |= P_STOPPED_SIG;
 2308                         p->p_xstat = sig;
 2309                         sig_suspend_threads(td, p, 1);
 2310                         if (p->p_numthreads == p->p_suspcount) {
 2311                                 /*
 2312                                  * only thread sending signal to another
 2313                                  * process can reach here, if thread is sending
 2314                                  * signal to its process, because thread does
 2315                                  * not suspend itself here, p_numthreads
 2316                                  * should never be equal to p_suspcount.
 2317                                  */
 2318                                 thread_stopped(p);
 2319                                 PROC_SUNLOCK(p);
 2320                                 sigqueue_delete_proc(p, p->p_xstat);
 2321                         } else
 2322                                 PROC_SUNLOCK(p);
 2323                         goto out;
 2324                 } 
 2325                 else
 2326                         goto runfast;
 2327                 /* NOTREACHED */
 2328         } else {
 2329                 /* Not in "NORMAL" state. discard the signal. */
 2330                 PROC_SUNLOCK(p);
 2331                 sigqueue_delete(sigqueue, sig);
 2332                 goto out;
 2333         }
 2334 
 2335         /*
 2336          * The process is not stopped so we need to apply the signal to all the
 2337          * running threads.
 2338          */
 2339 
 2340 runfast:
 2341         thread_lock(td);
 2342         wakeup_swapper = tdsigwakeup(td, sig, action, intrval);
 2343         thread_unlock(td);
 2344         thread_unsuspend(p);
 2345         PROC_SUNLOCK(p);
 2346         if (wakeup_swapper)
 2347                 kick_proc0();
 2348 out:
 2349         /* If we jump here, proc slock should not be owned. */
 2350         PROC_SLOCK_ASSERT(p, MA_NOTOWNED);
 2351         return (ret);
 2352 }
 2353 
 2354 /*
 2355  * The force of a signal has been directed against a single
 2356  * thread.  We need to see what we can do about knocking it
 2357  * out of any sleep it may be in etc.
 2358  */
 2359 static int
 2360 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval)
 2361 {
 2362         struct proc *p = td->td_proc;
 2363         register int prop;
 2364         int wakeup_swapper;
 2365 
 2366         wakeup_swapper = 0;
 2367         PROC_LOCK_ASSERT(p, MA_OWNED);
 2368         PROC_SLOCK_ASSERT(p, MA_OWNED);
 2369         THREAD_LOCK_ASSERT(td, MA_OWNED);
 2370         prop = sigprop(sig);
 2371 
 2372         /*
 2373          * Bring the priority of a thread up if we want it to get
 2374          * killed in this lifetime.
 2375          */
 2376         if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER)
 2377                 sched_prio(td, PUSER);
 2378 
 2379         if (TD_ON_SLEEPQ(td)) {
 2380                 /*
 2381                  * If thread is sleeping uninterruptibly
 2382                  * we can't interrupt the sleep... the signal will
 2383                  * be noticed when the process returns through
 2384                  * trap() or syscall().
 2385                  */
 2386                 if ((td->td_flags & TDF_SINTR) == 0)
 2387                         return (0);
 2388                 /*
 2389                  * If SIGCONT is default (or ignored) and process is
 2390                  * asleep, we are finished; the process should not
 2391                  * be awakened.
 2392                  */
 2393                 if ((prop & SA_CONT) && action == SIG_DFL) {
 2394                         thread_unlock(td);
 2395                         PROC_SUNLOCK(p);
 2396                         sigqueue_delete(&p->p_sigqueue, sig);
 2397                         /*
 2398                          * It may be on either list in this state.
 2399                          * Remove from both for now.
 2400                          */
 2401                         sigqueue_delete(&td->td_sigqueue, sig);
 2402                         PROC_SLOCK(p);
 2403                         thread_lock(td);
 2404                         return (0);
 2405                 }
 2406 
 2407                 /*
 2408                  * Give low priority threads a better chance to run.
 2409                  */
 2410                 if (td->td_priority > PUSER)
 2411                         sched_prio(td, PUSER);
 2412 
 2413                 wakeup_swapper = sleepq_abort(td, intrval);
 2414         } else {
 2415                 /*
 2416                  * Other states do nothing with the signal immediately,
 2417                  * other than kicking ourselves if we are running.
 2418                  * It will either never be noticed, or noticed very soon.
 2419                  */
 2420 #ifdef SMP
 2421                 if (TD_IS_RUNNING(td) && td != curthread)
 2422                         forward_signal(td);
 2423 #endif
 2424         }
 2425         return (wakeup_swapper);
 2426 }
 2427 
 2428 static void
 2429 sig_suspend_threads(struct thread *td, struct proc *p, int sending)
 2430 {
 2431         struct thread *td2;
 2432 
 2433         PROC_LOCK_ASSERT(p, MA_OWNED);
 2434         PROC_SLOCK_ASSERT(p, MA_OWNED);
 2435 
 2436         FOREACH_THREAD_IN_PROC(p, td2) {
 2437                 thread_lock(td2);
 2438                 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) &&
 2439                     (td2->td_flags & TDF_SINTR) &&
 2440                     !TD_IS_SUSPENDED(td2)) {
 2441                         thread_suspend_one(td2);
 2442                 } else {
 2443                         if (sending || td != td2)
 2444                                 td2->td_flags |= TDF_ASTPENDING;
 2445 #ifdef SMP
 2446                         if (TD_IS_RUNNING(td2) && td2 != td)
 2447                                 forward_signal(td2);
 2448 #endif
 2449                 }
 2450                 thread_unlock(td2);
 2451         }
 2452 }
 2453 
 2454 int
 2455 ptracestop(struct thread *td, int sig)
 2456 {
 2457         struct proc *p = td->td_proc;
 2458 
 2459         PROC_LOCK_ASSERT(p, MA_OWNED);
 2460         WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
 2461             &p->p_mtx.lock_object, "Stopping for traced signal");
 2462 
 2463         thread_lock(td);
 2464         td->td_flags |= TDF_XSIG;
 2465         thread_unlock(td);
 2466         td->td_xsig = sig;
 2467         PROC_SLOCK(p);
 2468         while ((p->p_flag & P_TRACED) && (td->td_flags & TDF_XSIG)) {
 2469                 if (p->p_flag & P_SINGLE_EXIT) {
 2470                         thread_lock(td);
 2471                         td->td_flags &= ~TDF_XSIG;
 2472                         thread_unlock(td);
 2473                         PROC_SUNLOCK(p);
 2474                         return (sig);
 2475                 }
 2476                 /*
 2477                  * Just make wait() to work, the last stopped thread
 2478                  * will win.
 2479                  */
 2480                 p->p_xstat = sig;
 2481                 p->p_xthread = td;
 2482                 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE);
 2483                 sig_suspend_threads(td, p, 0);
 2484 stopme:
 2485                 thread_suspend_switch(td);
 2486                 if (!(p->p_flag & P_TRACED)) {
 2487                         break;
 2488                 }
 2489                 if (td->td_flags & TDF_DBSUSPEND) {
 2490                         if (p->p_flag & P_SINGLE_EXIT)
 2491                                 break;
 2492                         goto stopme;
 2493                 }
 2494         }
 2495         PROC_SUNLOCK(p);
 2496         return (td->td_xsig);
 2497 }
 2498 
 2499 /*
 2500  * If the current process has received a signal (should be caught or cause
 2501  * termination, should interrupt current syscall), return the signal number.
 2502  * Stop signals with default action are processed immediately, then cleared;
 2503  * they aren't returned.  This is checked after each entry to the system for
 2504  * a syscall or trap (though this can usually be done without calling issignal
 2505  * by checking the pending signal masks in cursig.) The normal call
 2506  * sequence is
 2507  *
 2508  *      while (sig = cursig(curthread))
 2509  *              postsig(sig);
 2510  */
 2511 static int
 2512 issignal(td)
 2513         struct thread *td;
 2514 {
 2515         struct proc *p;
 2516         struct sigacts *ps;
 2517         sigset_t sigpending;
 2518         int sig, prop, newsig;
 2519 
 2520         p = td->td_proc;
 2521         ps = p->p_sigacts;
 2522         mtx_assert(&ps->ps_mtx, MA_OWNED);
 2523         PROC_LOCK_ASSERT(p, MA_OWNED);
 2524         for (;;) {
 2525                 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
 2526 
 2527                 sigpending = td->td_sigqueue.sq_signals;
 2528                 SIGSETNAND(sigpending, td->td_sigmask);
 2529 
 2530                 if (p->p_flag & P_PPWAIT)
 2531                         SIG_STOPSIGMASK(sigpending);
 2532                 if (SIGISEMPTY(sigpending))     /* no signal to send */
 2533                         return (0);
 2534                 sig = sig_ffs(&sigpending);
 2535 
 2536                 if (p->p_stops & S_SIG) {
 2537                         mtx_unlock(&ps->ps_mtx);
 2538                         stopevent(p, S_SIG, sig);
 2539                         mtx_lock(&ps->ps_mtx);
 2540                 }
 2541 
 2542                 /*
 2543                  * We should see pending but ignored signals
 2544                  * only if P_TRACED was on when they were posted.
 2545                  */
 2546                 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) {
 2547                         sigqueue_delete(&td->td_sigqueue, sig);
 2548 #ifdef KSE
 2549                         if (td->td_pflags & TDP_SA)
 2550                                 SIGADDSET(td->td_sigmask, sig);
 2551 #endif
 2552                         continue;
 2553                 }
 2554                 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) {
 2555                         /*
 2556                          * If traced, always stop.
 2557                          */
 2558                         mtx_unlock(&ps->ps_mtx);
 2559                         newsig = ptracestop(td, sig);
 2560                         mtx_lock(&ps->ps_mtx);
 2561 
 2562 #ifdef KSE
 2563                         if (td->td_pflags & TDP_SA)
 2564                                 SIGADDSET(td->td_sigmask, sig);
 2565 
 2566 #endif
 2567                         if (sig != newsig) {
 2568                                 ksiginfo_t ksi;
 2569                                 /*
 2570                                  * clear old signal.
 2571                                  * XXX shrug off debugger, it causes siginfo to
 2572                                  * be thrown away.
 2573                                  */
 2574                                 sigqueue_get(&td->td_sigqueue, sig, &ksi);
 2575 
 2576                                 /*
 2577                                  * If parent wants us to take the signal,
 2578                                  * then it will leave it in p->p_xstat;
 2579                                  * otherwise we just look for signals again.
 2580                                 */
 2581                                 if (newsig == 0)
 2582                                         continue;
 2583                                 sig = newsig;
 2584 
 2585                                 /*
 2586                                  * Put the new signal into td_sigqueue. If the
 2587                                  * signal is being masked, look for other signals.
 2588                                  */
 2589                                 SIGADDSET(td->td_sigqueue.sq_signals, sig);
 2590 #ifdef KSE
 2591                                 if (td->td_pflags & TDP_SA)
 2592                                         SIGDELSET(td->td_sigmask, sig);
 2593 #endif
 2594                                 if (SIGISMEMBER(td->td_sigmask, sig))
 2595                                         continue;
 2596                                 signotify(td);
 2597                         }
 2598 
 2599                         /*
 2600                          * If the traced bit got turned off, go back up
 2601                          * to the top to rescan signals.  This ensures
 2602                          * that p_sig* and p_sigact are consistent.
 2603                          */
 2604                         if ((p->p_flag & P_TRACED) == 0)
 2605                                 continue;
 2606                 }
 2607 
 2608                 prop = sigprop(sig);
 2609 
 2610                 /*
 2611                  * Decide whether the signal should be returned.
 2612                  * Return the signal's number, or fall through
 2613                  * to clear it from the pending mask.
 2614                  */
 2615                 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
 2616 
 2617                 case (intptr_t)SIG_DFL:
 2618                         /*
 2619                          * Don't take default actions on system processes.
 2620                          */
 2621                         if (p->p_pid <= 1) {
 2622 #ifdef DIAGNOSTIC
 2623                                 /*
 2624                                  * Are you sure you want to ignore SIGSEGV
 2625                                  * in init? XXX
 2626                                  */
 2627                                 printf("Process (pid %lu) got signal %d\n",
 2628                                         (u_long)p->p_pid, sig);
 2629 #endif
 2630                                 break;          /* == ignore */
 2631                         }
 2632                         /*
 2633                          * If there is a pending stop signal to process
 2634                          * with default action, stop here,
 2635                          * then clear the signal.  However,
 2636                          * if process is member of an orphaned
 2637                          * process group, ignore tty stop signals.
 2638                          */
 2639                         if (prop & SA_STOP) {
 2640                                 if (p->p_flag & P_TRACED ||
 2641                                     (p->p_pgrp->pg_jobc == 0 &&
 2642                                      prop & SA_TTYSTOP))
 2643                                         break;  /* == ignore */
 2644                                 mtx_unlock(&ps->ps_mtx);
 2645                                 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
 2646                                     &p->p_mtx.lock_object, "Catching SIGSTOP");
 2647                                 p->p_flag |= P_STOPPED_SIG;
 2648                                 p->p_xstat = sig;
 2649                                 PROC_SLOCK(p);
 2650                                 sig_suspend_threads(td, p, 0);
 2651                                 thread_suspend_switch(td);
 2652                                 PROC_SUNLOCK(p);
 2653                                 mtx_lock(&ps->ps_mtx);
 2654                                 break;
 2655                         } else if (prop & SA_IGNORE) {
 2656                                 /*
 2657                                  * Except for SIGCONT, shouldn't get here.
 2658                                  * Default action is to ignore; drop it.
 2659                                  */
 2660                                 break;          /* == ignore */
 2661                         } else
 2662                                 return (sig);
 2663                         /*NOTREACHED*/
 2664 
 2665                 case (intptr_t)SIG_IGN:
 2666                         /*
 2667                          * Masking above should prevent us ever trying
 2668                          * to take action on an ignored signal other
 2669                          * than SIGCONT, unless process is traced.
 2670                          */
 2671                         if ((prop & SA_CONT) == 0 &&
 2672                             (p->p_flag & P_TRACED) == 0)
 2673                                 printf("issignal\n");
 2674                         break;          /* == ignore */
 2675 
 2676                 default:
 2677                         /*
 2678                          * This signal has an action, let
 2679                          * postsig() process it.
 2680                          */
 2681                         return (sig);
 2682                 }
 2683                 sigqueue_delete(&td->td_sigqueue, sig);         /* take the signal! */
 2684         }
 2685         /* NOTREACHED */
 2686 }
 2687 
 2688 void
 2689 thread_stopped(struct proc *p)
 2690 {
 2691         int n;
 2692 
 2693         PROC_LOCK_ASSERT(p, MA_OWNED);
 2694         PROC_SLOCK_ASSERT(p, MA_OWNED);
 2695         n = p->p_suspcount;
 2696         if (p == curproc)
 2697                 n++;
 2698         if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) {
 2699                 PROC_SUNLOCK(p);
 2700                 p->p_flag &= ~P_WAITED;
 2701                 PROC_LOCK(p->p_pptr);
 2702                 childproc_stopped(p, (p->p_flag & P_TRACED) ?
 2703                         CLD_TRAPPED : CLD_STOPPED);
 2704                 PROC_UNLOCK(p->p_pptr);
 2705                 PROC_SLOCK(p);
 2706         }
 2707 }
 2708  
 2709 /*
 2710  * Take the action for the specified signal
 2711  * from the current set of pending signals.
 2712  */
 2713 void
 2714 postsig(sig)
 2715         register int sig;
 2716 {
 2717         struct thread *td = curthread;
 2718         register struct proc *p = td->td_proc;
 2719         struct sigacts *ps;
 2720         sig_t action;
 2721         ksiginfo_t ksi;
 2722         sigset_t returnmask;
 2723         int code;
 2724 
 2725         KASSERT(sig != 0, ("postsig"));
 2726 
 2727         PROC_LOCK_ASSERT(p, MA_OWNED);
 2728         ps = p->p_sigacts;
 2729         mtx_assert(&ps->ps_mtx, MA_OWNED);
 2730         ksiginfo_init(&ksi);
 2731         sigqueue_get(&td->td_sigqueue, sig, &ksi);
 2732         ksi.ksi_signo = sig;
 2733         if (ksi.ksi_code == SI_TIMER)
 2734                 itimer_accept(p, ksi.ksi_timerid, &ksi);
 2735         action = ps->ps_sigact[_SIG_IDX(sig)];
 2736 #ifdef KTRACE
 2737         if (KTRPOINT(td, KTR_PSIG))
 2738                 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ?
 2739                     &td->td_oldsigmask : &td->td_sigmask, 0);
 2740 #endif
 2741         if (p->p_stops & S_SIG) {
 2742                 mtx_unlock(&ps->ps_mtx);
 2743                 stopevent(p, S_SIG, sig);
 2744                 mtx_lock(&ps->ps_mtx);
 2745         }
 2746 
 2747 #ifdef KSE
 2748         if (!(td->td_pflags & TDP_SA) && action == SIG_DFL) {
 2749 #else
 2750         if (action == SIG_DFL) {
 2751 #endif
 2752                 /*
 2753                  * Default action, where the default is to kill
 2754                  * the process.  (Other cases were ignored above.)
 2755                  */
 2756                 mtx_unlock(&ps->ps_mtx);
 2757                 sigexit(td, sig);
 2758                 /* NOTREACHED */
 2759         } else {
 2760 #ifdef KSE
 2761                 if (td->td_pflags & TDP_SA) {
 2762                         if (sig == SIGKILL) {
 2763                                 mtx_unlock(&ps->ps_mtx);
 2764                                 sigexit(td, sig);
 2765                         }
 2766                 }
 2767 
 2768 #endif
 2769                 /*
 2770                  * If we get here, the signal must be caught.
 2771                  */
 2772                 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig),
 2773                     ("postsig action"));
 2774                 /*
 2775                  * Set the new mask value and also defer further
 2776                  * occurrences of this signal.
 2777                  *
 2778                  * Special case: user has done a sigsuspend.  Here the
 2779                  * current mask is not of interest, but rather the
 2780                  * mask from before the sigsuspend is what we want
 2781                  * restored after the signal processing is completed.
 2782                  */
 2783                 if (td->td_pflags & TDP_OLDMASK) {
 2784                         returnmask = td->td_oldsigmask;
 2785                         td->td_pflags &= ~TDP_OLDMASK;
 2786                 } else
 2787                         returnmask = td->td_sigmask;
 2788 
 2789                 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
 2790                 if (!SIGISMEMBER(ps->ps_signodefer, sig))
 2791                         SIGADDSET(td->td_sigmask, sig);
 2792 
 2793                 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
 2794                         /*
 2795                          * See kern_sigaction() for origin of this code.
 2796                          */
 2797                         SIGDELSET(ps->ps_sigcatch, sig);
 2798                         if (sig != SIGCONT &&
 2799                             sigprop(sig) & SA_IGNORE)
 2800                                 SIGADDSET(ps->ps_sigignore, sig);
 2801                         ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
 2802                 }
 2803                 td->td_ru.ru_nsignals++;
 2804                 if (p->p_sig != sig) {
 2805                         code = 0;
 2806                 } else {
 2807                         code = p->p_code;
 2808                         p->p_code = 0;
 2809                         p->p_sig = 0;
 2810                 }
 2811 #ifdef KSE
 2812                 if (td->td_pflags & TDP_SA)
 2813                         thread_signal_add(curthread, &ksi);
 2814                 else
 2815                         (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask);
 2816 #else
 2817                 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask);
 2818 #endif
 2819         }
 2820 }
 2821 
 2822 /*
 2823  * Kill the current process for stated reason.
 2824  */
 2825 void
 2826 killproc(p, why)
 2827         struct proc *p;
 2828         char *why;
 2829 {
 2830 
 2831         PROC_LOCK_ASSERT(p, MA_OWNED);
 2832         CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)",
 2833                 p, p->p_pid, p->p_comm);
 2834         log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm,
 2835                 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
 2836         psignal(p, SIGKILL);
 2837 }
 2838 
 2839 /*
 2840  * Force the current process to exit with the specified signal, dumping core
 2841  * if appropriate.  We bypass the normal tests for masked and caught signals,
 2842  * allowing unrecoverable failures to terminate the process without changing
 2843  * signal state.  Mark the accounting record with the signal termination.
 2844  * If dumping core, save the signal number for the debugger.  Calls exit and
 2845  * does not return.
 2846  */
 2847 void
 2848 sigexit(td, sig)
 2849         struct thread *td;
 2850         int sig;
 2851 {
 2852         struct proc *p = td->td_proc;
 2853 
 2854         PROC_LOCK_ASSERT(p, MA_OWNED);
 2855         p->p_acflag |= AXSIG;
 2856         /*
 2857          * We must be single-threading to generate a core dump.  This
 2858          * ensures that the registers in the core file are up-to-date.
 2859          * Also, the ELF dump handler assumes that the thread list doesn't
 2860          * change out from under it.
 2861          *
 2862          * XXX If another thread attempts to single-thread before us
 2863          *     (e.g. via fork()), we won't get a dump at all.
 2864          */
 2865         if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) {
 2866                 p->p_sig = sig;
 2867                 /*
 2868                  * Log signals which would cause core dumps
 2869                  * (Log as LOG_INFO to appease those who don't want
 2870                  * these messages.)
 2871                  * XXX : Todo, as well as euid, write out ruid too
 2872                  * Note that coredump() drops proc lock.
 2873                  */
 2874                 if (coredump(td) == 0)
 2875                         sig |= WCOREFLAG;
 2876                 if (kern_logsigexit)
 2877                         log(LOG_INFO,
 2878                             "pid %d (%s), uid %d: exited on signal %d%s\n",
 2879                             p->p_pid, p->p_comm,
 2880                             td->td_ucred ? td->td_ucred->cr_uid : -1,
 2881                             sig &~ WCOREFLAG,
 2882                             sig & WCOREFLAG ? " (core dumped)" : "");
 2883         } else
 2884                 PROC_UNLOCK(p);
 2885         exit1(td, W_EXITCODE(0, sig));
 2886         /* NOTREACHED */
 2887 }
 2888 
 2889 /*
 2890  * Send queued SIGCHLD to parent when child process's state
 2891  * is changed.
 2892  */
 2893 static void
 2894 sigparent(struct proc *p, int reason, int status)
 2895 {
 2896         PROC_LOCK_ASSERT(p, MA_OWNED);
 2897         PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
 2898 
 2899         if (p->p_ksi != NULL) {
 2900                 p->p_ksi->ksi_signo  = SIGCHLD;
 2901                 p->p_ksi->ksi_code   = reason;
 2902                 p->p_ksi->ksi_status = status;
 2903                 p->p_ksi->ksi_pid    = p->p_pid;
 2904                 p->p_ksi->ksi_uid    = p->p_ucred->cr_ruid;
 2905                 if (KSI_ONQ(p->p_ksi))
 2906                         return;
 2907         }
 2908         tdsignal(p->p_pptr, NULL, SIGCHLD, p->p_ksi);
 2909 }
 2910 
 2911 static void
 2912 childproc_jobstate(struct proc *p, int reason, int status)
 2913 {
 2914         struct sigacts *ps;
 2915 
 2916         PROC_LOCK_ASSERT(p, MA_OWNED);
 2917         PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
 2918 
 2919         /*
 2920          * Wake up parent sleeping in kern_wait(), also send
 2921          * SIGCHLD to parent, but SIGCHLD does not guarantee
 2922          * that parent will awake, because parent may masked
 2923          * the signal.
 2924          */
 2925         p->p_pptr->p_flag |= P_STATCHILD;
 2926         wakeup(p->p_pptr);
 2927 
 2928         ps = p->p_pptr->p_sigacts;
 2929         mtx_lock(&ps->ps_mtx);
 2930         if ((ps->ps_flag & PS_NOCLDSTOP) == 0) {
 2931                 mtx_unlock(&ps->ps_mtx);
 2932                 sigparent(p, reason, status);
 2933         } else
 2934                 mtx_unlock(&ps->ps_mtx);
 2935 }
 2936 
 2937 void
 2938 childproc_stopped(struct proc *p, int reason)
 2939 {
 2940         childproc_jobstate(p, reason, p->p_xstat);
 2941 }
 2942 
 2943 void
 2944 childproc_continued(struct proc *p)
 2945 {
 2946         childproc_jobstate(p, CLD_CONTINUED, SIGCONT);
 2947 }
 2948 
 2949 void
 2950 childproc_exited(struct proc *p)
 2951 {
 2952         int reason;
 2953         int status = p->p_xstat; /* convert to int */
 2954 
 2955         reason = CLD_EXITED;
 2956         if (WCOREDUMP(status))
 2957                 reason = CLD_DUMPED;
 2958         else if (WIFSIGNALED(status))
 2959                 reason = CLD_KILLED;
 2960         /*
 2961          * XXX avoid calling wakeup(p->p_pptr), the work is
 2962          * done in exit1().
 2963          */
 2964         sigparent(p, reason, status);
 2965 }
 2966 
 2967 static char corefilename[MAXPATHLEN] = {"%N.core"};
 2968 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
 2969               sizeof(corefilename), "process corefile name format string");
 2970 
 2971 /*
 2972  * expand_name(name, uid, pid)
 2973  * Expand the name described in corefilename, using name, uid, and pid.
 2974  * corefilename is a printf-like string, with three format specifiers:
 2975  *      %N      name of process ("name")
 2976  *      %P      process id (pid)
 2977  *      %U      user id (uid)
 2978  * For example, "%N.core" is the default; they can be disabled completely
 2979  * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
 2980  * This is controlled by the sysctl variable kern.corefile (see above).
 2981  */
 2982 static char *
 2983 expand_name(name, uid, pid)
 2984         const char *name;
 2985         uid_t uid;
 2986         pid_t pid;
 2987 {
 2988         struct sbuf sb;
 2989         const char *format;
 2990         char *temp;
 2991         size_t i;
 2992 
 2993         format = corefilename;
 2994         temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO);
 2995         if (temp == NULL)
 2996                 return (NULL);
 2997         (void)sbuf_new(&sb, temp, MAXPATHLEN, SBUF_FIXEDLEN);
 2998         for (i = 0; format[i]; i++) {
 2999                 switch (format[i]) {
 3000                 case '%':       /* Format character */
 3001                         i++;
 3002                         switch (format[i]) {
 3003                         case '%':
 3004                                 sbuf_putc(&sb, '%');
 3005                                 break;
 3006                         case 'N':       /* process name */
 3007                                 sbuf_printf(&sb, "%s", name);
 3008                                 break;
 3009                         case 'P':       /* process id */
 3010                                 sbuf_printf(&sb, "%u", pid);
 3011                                 break;
 3012                         case 'U':       /* user id */
 3013                                 sbuf_printf(&sb, "%u", uid);
 3014                                 break;
 3015                         default:
 3016                                 log(LOG_ERR,
 3017                                     "Unknown format character %c in "
 3018                                     "corename `%s'\n", format[i], format);
 3019                         }
 3020                         break;
 3021                 default:
 3022                         sbuf_putc(&sb, format[i]);
 3023                 }
 3024         }
 3025         if (sbuf_overflowed(&sb)) {
 3026                 sbuf_delete(&sb);
 3027                 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too "
 3028                     "long\n", (long)pid, name, (u_long)uid);
 3029                 free(temp, M_TEMP);
 3030                 return (NULL);
 3031         }
 3032         sbuf_finish(&sb);
 3033         sbuf_delete(&sb);
 3034         return (temp);
 3035 }
 3036 
 3037 /*
 3038  * Dump a process' core.  The main routine does some
 3039  * policy checking, and creates the name of the coredump;
 3040  * then it passes on a vnode and a size limit to the process-specific
 3041  * coredump routine if there is one; if there _is not_ one, it returns
 3042  * ENOSYS; otherwise it returns the error from the process-specific routine.
 3043  */
 3044 
 3045 static int
 3046 coredump(struct thread *td)
 3047 {
 3048         struct proc *p = td->td_proc;
 3049         register struct vnode *vp;
 3050         register struct ucred *cred = td->td_ucred;
 3051         struct flock lf;
 3052         struct nameidata nd;
 3053         struct vattr vattr;
 3054         int error, error1, flags, locked;
 3055         struct mount *mp;
 3056         char *name;                     /* name of corefile */
 3057         off_t limit;
 3058         int vfslocked;
 3059 
 3060         PROC_LOCK_ASSERT(p, MA_OWNED);
 3061         MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td);
 3062         _STOPEVENT(p, S_CORE, 0);
 3063 
 3064         name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid);
 3065         if (name == NULL) {
 3066                 PROC_UNLOCK(p);
 3067 #ifdef AUDIT
 3068                 audit_proc_coredump(td, NULL, EINVAL);
 3069 #endif
 3070                 return (EINVAL);
 3071         }
 3072         if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) {
 3073                 PROC_UNLOCK(p);
 3074 #ifdef AUDIT
 3075                 audit_proc_coredump(td, name, EFAULT);
 3076 #endif
 3077                 free(name, M_TEMP);
 3078                 return (EFAULT);
 3079         }
 3080         
 3081         /*
 3082          * Note that the bulk of limit checking is done after
 3083          * the corefile is created.  The exception is if the limit
 3084          * for corefiles is 0, in which case we don't bother
 3085          * creating the corefile at all.  This layout means that
 3086          * a corefile is truncated instead of not being created,
 3087          * if it is larger than the limit.
 3088          */
 3089         limit = (off_t)lim_cur(p, RLIMIT_CORE);
 3090         PROC_UNLOCK(p);
 3091         if (limit == 0) {
 3092 #ifdef AUDIT
 3093                 audit_proc_coredump(td, name, EFBIG);
 3094 #endif
 3095                 free(name, M_TEMP);
 3096                 return (EFBIG);
 3097         }
 3098 
 3099 restart:
 3100         NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, name, td);
 3101         flags = O_CREAT | FWRITE | O_NOFOLLOW;
 3102         error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR, NULL);
 3103         if (error) {
 3104 #ifdef AUDIT
 3105                 audit_proc_coredump(td, name, error);
 3106 #endif
 3107                 free(name, M_TEMP);
 3108                 return (error);
 3109         }
 3110         vfslocked = NDHASGIANT(&nd);
 3111         NDFREE(&nd, NDF_ONLY_PNBUF);
 3112         vp = nd.ni_vp;
 3113 
 3114         /* Don't dump to non-regular files or files with links. */
 3115         if (vp->v_type != VREG ||
 3116             VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) {
 3117                 VOP_UNLOCK(vp, 0, td);
 3118                 error = EFAULT;
 3119                 goto close;
 3120         }
 3121 
 3122         VOP_UNLOCK(vp, 0, td);
 3123         lf.l_whence = SEEK_SET;
 3124         lf.l_start = 0;
 3125         lf.l_len = 0;
 3126         lf.l_type = F_WRLCK;
 3127         locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0);
 3128 
 3129         if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
 3130                 lf.l_type = F_UNLCK;
 3131                 if (locked)
 3132                         VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
 3133                 if ((error = vn_close(vp, FWRITE, cred, td)) != 0)
 3134                         goto out;
 3135                 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
 3136                         goto out;
 3137                 VFS_UNLOCK_GIANT(vfslocked);
 3138                 goto restart;
 3139         }
 3140 
 3141         VATTR_NULL(&vattr);
 3142         vattr.va_size = 0;
 3143         if (set_core_nodump_flag)
 3144                 vattr.va_flags = UF_NODUMP;
 3145         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
 3146         VOP_LEASE(vp, td, cred, LEASE_WRITE);
 3147         VOP_SETATTR(vp, &vattr, cred, td);
 3148         VOP_UNLOCK(vp, 0, td);
 3149         vn_finished_write(mp);
 3150         PROC_LOCK(p);
 3151         p->p_acflag |= ACORE;
 3152         PROC_UNLOCK(p);
 3153 
 3154         error = p->p_sysent->sv_coredump ?
 3155           p->p_sysent->sv_coredump(td, vp, limit) :
 3156           ENOSYS;
 3157 
 3158         if (locked) {
 3159                 lf.l_type = F_UNLCK;
 3160                 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
 3161         }
 3162 close:
 3163         error1 = vn_close(vp, FWRITE, cred, td);
 3164         if (error == 0)
 3165                 error = error1;
 3166 out:
 3167 #ifdef AUDIT
 3168         audit_proc_coredump(td, name, error);
 3169 #endif
 3170         free(name, M_TEMP);
 3171         VFS_UNLOCK_GIANT(vfslocked);
 3172         return (error);
 3173 }
 3174 
 3175 /*
 3176  * Nonexistent system call-- signal process (may want to handle it).  Flag
 3177  * error in case process won't see signal immediately (blocked or ignored).
 3178  */
 3179 #ifndef _SYS_SYSPROTO_H_
 3180 struct nosys_args {
 3181         int     dummy;
 3182 };
 3183 #endif
 3184 /* ARGSUSED */
 3185 int
 3186 nosys(td, args)
 3187         struct thread *td;
 3188         struct nosys_args *args;
 3189 {
 3190         struct proc *p = td->td_proc;
 3191 
 3192         PROC_LOCK(p);
 3193         psignal(p, SIGSYS);
 3194         PROC_UNLOCK(p);
 3195         return (ENOSYS);
 3196 }
 3197 
 3198 /*
 3199  * Send a SIGIO or SIGURG signal to a process or process group using stored
 3200  * credentials rather than those of the current process.
 3201  */
 3202 void
 3203 pgsigio(sigiop, sig, checkctty)
 3204         struct sigio **sigiop;
 3205         int sig, checkctty;
 3206 {
 3207         struct sigio *sigio;
 3208 
 3209         SIGIO_LOCK();
 3210         sigio = *sigiop;
 3211         if (sigio == NULL) {
 3212                 SIGIO_UNLOCK();
 3213                 return;
 3214         }
 3215         if (sigio->sio_pgid > 0) {
 3216                 PROC_LOCK(sigio->sio_proc);
 3217                 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred))
 3218                         psignal(sigio->sio_proc, sig);
 3219                 PROC_UNLOCK(sigio->sio_proc);
 3220         } else if (sigio->sio_pgid < 0) {
 3221                 struct proc *p;
 3222 
 3223                 PGRP_LOCK(sigio->sio_pgrp);
 3224                 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
 3225                         PROC_LOCK(p);
 3226                         if (CANSIGIO(sigio->sio_ucred, p->p_ucred) &&
 3227                             (checkctty == 0 || (p->p_flag & P_CONTROLT)))
 3228                                 psignal(p, sig);
 3229                         PROC_UNLOCK(p);
 3230                 }
 3231                 PGRP_UNLOCK(sigio->sio_pgrp);
 3232         }
 3233         SIGIO_UNLOCK();
 3234 }
 3235 
 3236 static int
 3237 filt_sigattach(struct knote *kn)
 3238 {
 3239         struct proc *p = curproc;
 3240 
 3241         kn->kn_ptr.p_proc = p;
 3242         kn->kn_flags |= EV_CLEAR;               /* automatically set */
 3243 
 3244         knlist_add(&p->p_klist, kn, 0);
 3245 
 3246         return (0);
 3247 }
 3248 
 3249 static void
 3250 filt_sigdetach(struct knote *kn)
 3251 {
 3252         struct proc *p = kn->kn_ptr.p_proc;
 3253 
 3254         knlist_remove(&p->p_klist, kn, 0);
 3255 }
 3256 
 3257 /*
 3258  * signal knotes are shared with proc knotes, so we apply a mask to 
 3259  * the hint in order to differentiate them from process hints.  This
 3260  * could be avoided by using a signal-specific knote list, but probably
 3261  * isn't worth the trouble.
 3262  */
 3263 static int
 3264 filt_signal(struct knote *kn, long hint)
 3265 {
 3266 
 3267         if (hint & NOTE_SIGNAL) {
 3268                 hint &= ~NOTE_SIGNAL;
 3269 
 3270                 if (kn->kn_id == hint)
 3271                         kn->kn_data++;
 3272         }
 3273         return (kn->kn_data != 0);
 3274 }
 3275 
 3276 struct sigacts *
 3277 sigacts_alloc(void)
 3278 {
 3279         struct sigacts *ps;
 3280 
 3281         ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO);
 3282         ps->ps_refcnt = 1;
 3283         mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF);
 3284         return (ps);
 3285 }
 3286 
 3287 void
 3288 sigacts_free(struct sigacts *ps)
 3289 {
 3290 
 3291         mtx_lock(&ps->ps_mtx);
 3292         ps->ps_refcnt--;
 3293         if (ps->ps_refcnt == 0) {
 3294                 mtx_destroy(&ps->ps_mtx);
 3295                 free(ps, M_SUBPROC);
 3296         } else
 3297                 mtx_unlock(&ps->ps_mtx);
 3298 }
 3299 
 3300 struct sigacts *
 3301 sigacts_hold(struct sigacts *ps)
 3302 {
 3303         mtx_lock(&ps->ps_mtx);
 3304         ps->ps_refcnt++;
 3305         mtx_unlock(&ps->ps_mtx);
 3306         return (ps);
 3307 }
 3308 
 3309 void
 3310 sigacts_copy(struct sigacts *dest, struct sigacts *src)
 3311 {
 3312 
 3313         KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest"));
 3314         mtx_lock(&src->ps_mtx);
 3315         bcopy(src, dest, offsetof(struct sigacts, ps_refcnt));
 3316         mtx_unlock(&src->ps_mtx);
 3317 }
 3318 
 3319 int
 3320 sigacts_shared(struct sigacts *ps)
 3321 {
 3322         int shared;
 3323 
 3324         mtx_lock(&ps->ps_mtx);
 3325         shared = ps->ps_refcnt > 1;
 3326         mtx_unlock(&ps->ps_mtx);
 3327         return (shared);
 3328 }

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