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/8.2/sys/kern/kern_sig.c 214756 2010-11-03 21:24:21Z kib $");
   39 
   40 #include "opt_compat.h"
   41 #include "opt_kdtrace.h"
   42 #include "opt_ktrace.h"
   43 
   44 #include <sys/param.h>
   45 #include <sys/systm.h>
   46 #include <sys/signalvar.h>
   47 #include <sys/vnode.h>
   48 #include <sys/acct.h>
   49 #include <sys/condvar.h>
   50 #include <sys/event.h>
   51 #include <sys/fcntl.h>
   52 #include <sys/kernel.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/sdt.h>
   64 #include <sys/sbuf.h>
   65 #include <sys/sleepqueue.h>
   66 #include <sys/smp.h>
   67 #include <sys/stat.h>
   68 #include <sys/sx.h>
   69 #include <sys/syscallsubr.h>
   70 #include <sys/sysctl.h>
   71 #include <sys/sysent.h>
   72 #include <sys/syslog.h>
   73 #include <sys/sysproto.h>
   74 #include <sys/timers.h>
   75 #include <sys/unistd.h>
   76 #include <sys/wait.h>
   77 #include <vm/vm.h>
   78 #include <vm/vm_extern.h>
   79 #include <vm/uma.h>
   80 
   81 #include <machine/cpu.h>
   82 
   83 #include <security/audit/audit.h>
   84 
   85 #define ONSIG   32              /* NSIG for osig* syscalls.  XXX. */
   86 
   87 SDT_PROVIDER_DECLARE(proc);
   88 SDT_PROBE_DEFINE(proc, kernel, , signal_send);
   89 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 0, "struct thread *");
   90 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 1, "struct proc *");
   91 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 2, "int");
   92 SDT_PROBE_DEFINE(proc, kernel, , signal_clear);
   93 SDT_PROBE_ARGTYPE(proc, kernel, , signal_clear, 0, "int");
   94 SDT_PROBE_ARGTYPE(proc, kernel, , signal_clear, 1, "ksiginfo_t *");
   95 SDT_PROBE_DEFINE(proc, kernel, , signal_discard);
   96 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 0, "struct thread *");
   97 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 1, "struct proc *");
   98 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 2, "int");
   99 
  100 static int      coredump(struct thread *);
  101 static char     *expand_name(const char *, uid_t, pid_t);
  102 static int      killpg1(struct thread *td, int sig, int pgid, int all,
  103                     ksiginfo_t *ksi);
  104 static int      issignal(struct thread *td, int stop_allowed);
  105 static int      sigprop(int sig);
  106 static void     tdsigwakeup(struct thread *, int, sig_t, int);
  107 static void     sig_suspend_threads(struct thread *, struct proc *, int);
  108 static int      filt_sigattach(struct knote *kn);
  109 static void     filt_sigdetach(struct knote *kn);
  110 static int      filt_signal(struct knote *kn, long hint);
  111 static struct thread *sigtd(struct proc *p, int sig, int prop);
  112 static void     sigqueue_start(void);
  113 
  114 static uma_zone_t       ksiginfo_zone = NULL;
  115 struct filterops sig_filtops =
  116         { 0, filt_sigattach, filt_sigdetach, filt_signal };
  117 
  118 int     kern_logsigexit = 1;
  119 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 
  120     &kern_logsigexit, 0, 
  121     "Log processes quitting on abnormal signals to syslog(3)");
  122 
  123 static int      kern_forcesigexit = 1;
  124 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW,
  125     &kern_forcesigexit, 0, "Force trap signal to be handled");
  126 
  127 SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, "POSIX real time signal");
  128 
  129 static int      max_pending_per_proc = 128;
  130 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW,
  131     &max_pending_per_proc, 0, "Max pending signals per proc");
  132 
  133 static int      preallocate_siginfo = 1024;
  134 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo);
  135 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD,
  136     &preallocate_siginfo, 0, "Preallocated signal memory size");
  137 
  138 static int      signal_overflow = 0;
  139 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD,
  140     &signal_overflow, 0, "Number of signals overflew");
  141 
  142 static int      signal_alloc_fail = 0;
  143 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD,
  144     &signal_alloc_fail, 0, "signals failed to be allocated");
  145 
  146 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL);
  147 
  148 /*
  149  * Policy -- Can ucred cr1 send SIGIO to process cr2?
  150  * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG
  151  * in the right situations.
  152  */
  153 #define CANSIGIO(cr1, cr2) \
  154         ((cr1)->cr_uid == 0 || \
  155             (cr1)->cr_ruid == (cr2)->cr_ruid || \
  156             (cr1)->cr_uid == (cr2)->cr_ruid || \
  157             (cr1)->cr_ruid == (cr2)->cr_uid || \
  158             (cr1)->cr_uid == (cr2)->cr_uid)
  159 
  160 int sugid_coredump;
  161 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 
  162     &sugid_coredump, 0, "Enable coredumping set user/group ID processes");
  163 
  164 static int      do_coredump = 1;
  165 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
  166         &do_coredump, 0, "Enable/Disable coredumps");
  167 
  168 static int      set_core_nodump_flag = 0;
  169 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag,
  170         0, "Enable setting the NODUMP flag on coredump files");
  171 
  172 /*
  173  * Signal properties and actions.
  174  * The array below categorizes the signals and their default actions
  175  * according to the following properties:
  176  */
  177 #define SA_KILL         0x01            /* terminates process by default */
  178 #define SA_CORE         0x02            /* ditto and coredumps */
  179 #define SA_STOP         0x04            /* suspend process */
  180 #define SA_TTYSTOP      0x08            /* ditto, from tty */
  181 #define SA_IGNORE       0x10            /* ignore by default */
  182 #define SA_CONT         0x20            /* continue if suspended */
  183 #define SA_CANTMASK     0x40            /* non-maskable, catchable */
  184 #define SA_PROC         0x80            /* deliverable to any thread */
  185 
  186 static int sigproptbl[NSIG] = {
  187         SA_KILL|SA_PROC,                /* SIGHUP */
  188         SA_KILL|SA_PROC,                /* SIGINT */
  189         SA_KILL|SA_CORE|SA_PROC,        /* SIGQUIT */
  190         SA_KILL|SA_CORE,                /* SIGILL */
  191         SA_KILL|SA_CORE,                /* SIGTRAP */
  192         SA_KILL|SA_CORE,                /* SIGABRT */
  193         SA_KILL|SA_CORE|SA_PROC,        /* SIGEMT */
  194         SA_KILL|SA_CORE,                /* SIGFPE */
  195         SA_KILL|SA_PROC,                /* SIGKILL */
  196         SA_KILL|SA_CORE,                /* SIGBUS */
  197         SA_KILL|SA_CORE,                /* SIGSEGV */
  198         SA_KILL|SA_CORE,                /* SIGSYS */
  199         SA_KILL|SA_PROC,                /* SIGPIPE */
  200         SA_KILL|SA_PROC,                /* SIGALRM */
  201         SA_KILL|SA_PROC,                /* SIGTERM */
  202         SA_IGNORE|SA_PROC,              /* SIGURG */
  203         SA_STOP|SA_PROC,                /* SIGSTOP */
  204         SA_STOP|SA_TTYSTOP|SA_PROC,     /* SIGTSTP */
  205         SA_IGNORE|SA_CONT|SA_PROC,      /* SIGCONT */
  206         SA_IGNORE|SA_PROC,              /* SIGCHLD */
  207         SA_STOP|SA_TTYSTOP|SA_PROC,     /* SIGTTIN */
  208         SA_STOP|SA_TTYSTOP|SA_PROC,     /* SIGTTOU */
  209         SA_IGNORE|SA_PROC,              /* SIGIO */
  210         SA_KILL,                        /* SIGXCPU */
  211         SA_KILL,                        /* SIGXFSZ */
  212         SA_KILL|SA_PROC,                /* SIGVTALRM */
  213         SA_KILL|SA_PROC,                /* SIGPROF */
  214         SA_IGNORE|SA_PROC,              /* SIGWINCH  */
  215         SA_IGNORE|SA_PROC,              /* SIGINFO */
  216         SA_KILL|SA_PROC,                /* SIGUSR1 */
  217         SA_KILL|SA_PROC,                /* SIGUSR2 */
  218 };
  219 
  220 static void reschedule_signals(struct proc *p, sigset_t block, int flags);
  221 
  222 static void
  223 sigqueue_start(void)
  224 {
  225         ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t),
  226                 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
  227         uma_prealloc(ksiginfo_zone, preallocate_siginfo);
  228         p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS);
  229         p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1);
  230         p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc);
  231 }
  232 
  233 ksiginfo_t *
  234 ksiginfo_alloc(int wait)
  235 {
  236         int flags;
  237 
  238         flags = M_ZERO;
  239         if (! wait)
  240                 flags |= M_NOWAIT;
  241         if (ksiginfo_zone != NULL)
  242                 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags));
  243         return (NULL);
  244 }
  245 
  246 void
  247 ksiginfo_free(ksiginfo_t *ksi)
  248 {
  249         uma_zfree(ksiginfo_zone, ksi);
  250 }
  251 
  252 static __inline int
  253 ksiginfo_tryfree(ksiginfo_t *ksi)
  254 {
  255         if (!(ksi->ksi_flags & KSI_EXT)) {
  256                 uma_zfree(ksiginfo_zone, ksi);
  257                 return (1);
  258         }
  259         return (0);
  260 }
  261 
  262 void
  263 sigqueue_init(sigqueue_t *list, struct proc *p)
  264 {
  265         SIGEMPTYSET(list->sq_signals);
  266         SIGEMPTYSET(list->sq_kill);
  267         TAILQ_INIT(&list->sq_list);
  268         list->sq_proc = p;
  269         list->sq_flags = SQ_INIT;
  270 }
  271 
  272 /*
  273  * Get a signal's ksiginfo.
  274  * Return:
  275  *      0       -       signal not found
  276  *      others  -       signal number
  277  */ 
  278 static int
  279 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si)
  280 {
  281         struct proc *p = sq->sq_proc;
  282         struct ksiginfo *ksi, *next;
  283         int count = 0;
  284 
  285         KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
  286 
  287         if (!SIGISMEMBER(sq->sq_signals, signo))
  288                 return (0);
  289 
  290         if (SIGISMEMBER(sq->sq_kill, signo)) {
  291                 count++;
  292                 SIGDELSET(sq->sq_kill, signo);
  293         }
  294 
  295         TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
  296                 if (ksi->ksi_signo == signo) {
  297                         if (count == 0) {
  298                                 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
  299                                 ksi->ksi_sigq = NULL;
  300                                 ksiginfo_copy(ksi, si);
  301                                 if (ksiginfo_tryfree(ksi) && p != NULL)
  302                                         p->p_pendingcnt--;
  303                         }
  304                         if (++count > 1)
  305                                 break;
  306                 }
  307         }
  308 
  309         if (count <= 1)
  310                 SIGDELSET(sq->sq_signals, signo);
  311         si->ksi_signo = signo;
  312         return (signo);
  313 }
  314 
  315 void
  316 sigqueue_take(ksiginfo_t *ksi)
  317 {
  318         struct ksiginfo *kp;
  319         struct proc     *p;
  320         sigqueue_t      *sq;
  321 
  322         if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL)
  323                 return;
  324 
  325         p = sq->sq_proc;
  326         TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
  327         ksi->ksi_sigq = NULL;
  328         if (!(ksi->ksi_flags & KSI_EXT) && p != NULL)
  329                 p->p_pendingcnt--;
  330 
  331         for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL;
  332              kp = TAILQ_NEXT(kp, ksi_link)) {
  333                 if (kp->ksi_signo == ksi->ksi_signo)
  334                         break;
  335         }
  336         if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo))
  337                 SIGDELSET(sq->sq_signals, ksi->ksi_signo);
  338 }
  339 
  340 static int
  341 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si)
  342 {
  343         struct proc *p = sq->sq_proc;
  344         struct ksiginfo *ksi;
  345         int ret = 0;
  346 
  347         KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
  348         
  349         if (signo == SIGKILL || signo == SIGSTOP || si == NULL) {
  350                 SIGADDSET(sq->sq_kill, signo);
  351                 goto out_set_bit;
  352         }
  353 
  354         /* directly insert the ksi, don't copy it */
  355         if (si->ksi_flags & KSI_INS) {
  356                 if (si->ksi_flags & KSI_HEAD)
  357                         TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link);
  358                 else
  359                         TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link);
  360                 si->ksi_sigq = sq;
  361                 goto out_set_bit;
  362         }
  363 
  364         if (__predict_false(ksiginfo_zone == NULL)) {
  365                 SIGADDSET(sq->sq_kill, signo);
  366                 goto out_set_bit;
  367         }
  368         
  369         if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) {
  370                 signal_overflow++;
  371                 ret = EAGAIN;
  372         } else if ((ksi = ksiginfo_alloc(0)) == NULL) {
  373                 signal_alloc_fail++;
  374                 ret = EAGAIN;
  375         } else {
  376                 if (p != NULL)
  377                         p->p_pendingcnt++;
  378                 ksiginfo_copy(si, ksi);
  379                 ksi->ksi_signo = signo;
  380                 if (si->ksi_flags & KSI_HEAD)
  381                         TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link);
  382                 else
  383                         TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link);
  384                 ksi->ksi_sigq = sq;
  385         }
  386 
  387         if ((si->ksi_flags & KSI_TRAP) != 0 ||
  388             (si->ksi_flags & KSI_SIGQ) == 0) {
  389                 if (ret != 0)
  390                         SIGADDSET(sq->sq_kill, signo);
  391                 ret = 0;
  392                 goto out_set_bit;
  393         }
  394 
  395         if (ret != 0)
  396                 return (ret);
  397         
  398 out_set_bit:
  399         SIGADDSET(sq->sq_signals, signo);
  400         return (ret);
  401 }
  402 
  403 void
  404 sigqueue_flush(sigqueue_t *sq)
  405 {
  406         struct proc *p = sq->sq_proc;
  407         ksiginfo_t *ksi;
  408 
  409         KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
  410 
  411         if (p != NULL)
  412                 PROC_LOCK_ASSERT(p, MA_OWNED);
  413 
  414         while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) {
  415                 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
  416                 ksi->ksi_sigq = NULL;
  417                 if (ksiginfo_tryfree(ksi) && p != NULL)
  418                         p->p_pendingcnt--;
  419         }
  420 
  421         SIGEMPTYSET(sq->sq_signals);
  422         SIGEMPTYSET(sq->sq_kill);
  423 }
  424 
  425 static void
  426 sigqueue_collect_set(sigqueue_t *sq, sigset_t *set)
  427 {
  428         ksiginfo_t *ksi;
  429 
  430         KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
  431 
  432         TAILQ_FOREACH(ksi, &sq->sq_list, ksi_link)
  433                 SIGADDSET(*set, ksi->ksi_signo);
  434         SIGSETOR(*set, sq->sq_kill);
  435 }
  436 
  437 static void
  438 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, sigset_t *setp)
  439 {
  440         sigset_t tmp, set;
  441         struct proc *p1, *p2;
  442         ksiginfo_t *ksi, *next;
  443 
  444         KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited"));
  445         KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited"));
  446         /*
  447          * make a copy, this allows setp to point to src or dst
  448          * sq_signals without trouble.
  449          */
  450         set = *setp;
  451         p1 = src->sq_proc;
  452         p2 = dst->sq_proc;
  453         /* Move siginfo to target list */
  454         TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) {
  455                 if (SIGISMEMBER(set, ksi->ksi_signo)) {
  456                         TAILQ_REMOVE(&src->sq_list, ksi, ksi_link);
  457                         if (p1 != NULL)
  458                                 p1->p_pendingcnt--;
  459                         TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link);
  460                         ksi->ksi_sigq = dst;
  461                         if (p2 != NULL)
  462                                 p2->p_pendingcnt++;
  463                 }
  464         }
  465 
  466         /* Move pending bits to target list */
  467         tmp = src->sq_kill;
  468         SIGSETAND(tmp, set);
  469         SIGSETOR(dst->sq_kill, tmp);
  470         SIGSETNAND(src->sq_kill, tmp);
  471 
  472         tmp = src->sq_signals;
  473         SIGSETAND(tmp, set);
  474         SIGSETOR(dst->sq_signals, tmp);
  475         SIGSETNAND(src->sq_signals, tmp);
  476 
  477         /* Finally, rescan src queue and set pending bits for it */
  478         sigqueue_collect_set(src, &src->sq_signals);
  479 }
  480 
  481 static void
  482 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo)
  483 {
  484         sigset_t set;
  485 
  486         SIGEMPTYSET(set);
  487         SIGADDSET(set, signo);
  488         sigqueue_move_set(src, dst, &set);
  489 }
  490 
  491 static void
  492 sigqueue_delete_set(sigqueue_t *sq, sigset_t *set)
  493 {
  494         struct proc *p = sq->sq_proc;
  495         ksiginfo_t *ksi, *next;
  496 
  497         KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited"));
  498 
  499         /* Remove siginfo queue */
  500         TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
  501                 if (SIGISMEMBER(*set, ksi->ksi_signo)) {
  502                         TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
  503                         ksi->ksi_sigq = NULL;
  504                         if (ksiginfo_tryfree(ksi) && p != NULL)
  505                                 p->p_pendingcnt--;
  506                 }
  507         }
  508         SIGSETNAND(sq->sq_kill, *set);
  509         SIGSETNAND(sq->sq_signals, *set);
  510         /* Finally, rescan queue and set pending bits for it */
  511         sigqueue_collect_set(sq, &sq->sq_signals);
  512 }
  513 
  514 void
  515 sigqueue_delete(sigqueue_t *sq, int signo)
  516 {
  517         sigset_t set;
  518 
  519         SIGEMPTYSET(set);
  520         SIGADDSET(set, signo);
  521         sigqueue_delete_set(sq, &set);
  522 }
  523 
  524 /* Remove a set of signals for a process */
  525 static void
  526 sigqueue_delete_set_proc(struct proc *p, sigset_t *set)
  527 {
  528         sigqueue_t worklist;
  529         struct thread *td0;
  530 
  531         PROC_LOCK_ASSERT(p, MA_OWNED);
  532 
  533         sigqueue_init(&worklist, NULL);
  534         sigqueue_move_set(&p->p_sigqueue, &worklist, set);
  535 
  536         FOREACH_THREAD_IN_PROC(p, td0)
  537                 sigqueue_move_set(&td0->td_sigqueue, &worklist, set);
  538 
  539         sigqueue_flush(&worklist);
  540 }
  541 
  542 void
  543 sigqueue_delete_proc(struct proc *p, int signo)
  544 {
  545         sigset_t set;
  546 
  547         SIGEMPTYSET(set);
  548         SIGADDSET(set, signo);
  549         sigqueue_delete_set_proc(p, &set);
  550 }
  551 
  552 static void
  553 sigqueue_delete_stopmask_proc(struct proc *p)
  554 {
  555         sigset_t set;
  556 
  557         SIGEMPTYSET(set);
  558         SIGADDSET(set, SIGSTOP);
  559         SIGADDSET(set, SIGTSTP);
  560         SIGADDSET(set, SIGTTIN);
  561         SIGADDSET(set, SIGTTOU);
  562         sigqueue_delete_set_proc(p, &set);
  563 }
  564 
  565 /*
  566  * Determine signal that should be delivered to process p, the current
  567  * process, 0 if none.  If there is a pending stop signal with default
  568  * action, the process stops in issignal().
  569  */
  570 int
  571 cursig(struct thread *td, int stop_allowed)
  572 {
  573         PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
  574         KASSERT(stop_allowed == SIG_STOP_ALLOWED ||
  575             stop_allowed == SIG_STOP_NOT_ALLOWED, ("cursig: stop_allowed"));
  576         mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED);
  577         THREAD_LOCK_ASSERT(td, MA_NOTOWNED);
  578         return (SIGPENDING(td) ? issignal(td, stop_allowed) : 0);
  579 }
  580 
  581 /*
  582  * Arrange for ast() to handle unmasked pending signals on return to user
  583  * mode.  This must be called whenever a signal is added to td_sigqueue or
  584  * unmasked in td_sigmask.
  585  */
  586 void
  587 signotify(struct thread *td)
  588 {
  589         struct proc *p;
  590 
  591         p = td->td_proc;
  592 
  593         PROC_LOCK_ASSERT(p, MA_OWNED);
  594 
  595         if (SIGPENDING(td)) {
  596                 thread_lock(td);
  597                 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING;
  598                 thread_unlock(td);
  599         }
  600 }
  601 
  602 int
  603 sigonstack(size_t sp)
  604 {
  605         struct thread *td = curthread;
  606 
  607         return ((td->td_pflags & TDP_ALTSTACK) ?
  608 #if defined(COMPAT_43)
  609             ((td->td_sigstk.ss_size == 0) ?
  610                 (td->td_sigstk.ss_flags & SS_ONSTACK) :
  611                 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size))
  612 #else
  613             ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)
  614 #endif
  615             : 0);
  616 }
  617 
  618 static __inline int
  619 sigprop(int sig)
  620 {
  621 
  622         if (sig > 0 && sig < NSIG)
  623                 return (sigproptbl[_SIG_IDX(sig)]);
  624         return (0);
  625 }
  626 
  627 int
  628 sig_ffs(sigset_t *set)
  629 {
  630         int i;
  631 
  632         for (i = 0; i < _SIG_WORDS; i++)
  633                 if (set->__bits[i])
  634                         return (ffs(set->__bits[i]) + (i * 32));
  635         return (0);
  636 }
  637 
  638 /*
  639  * kern_sigaction
  640  * sigaction
  641  * freebsd4_sigaction
  642  * osigaction
  643  */
  644 int
  645 kern_sigaction(td, sig, act, oact, flags)
  646         struct thread *td;
  647         register int sig;
  648         struct sigaction *act, *oact;
  649         int flags;
  650 {
  651         struct sigacts *ps;
  652         struct proc *p = td->td_proc;
  653 
  654         if (!_SIG_VALID(sig))
  655                 return (EINVAL);
  656 
  657         PROC_LOCK(p);
  658         ps = p->p_sigacts;
  659         mtx_lock(&ps->ps_mtx);
  660         if (oact) {
  661                 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
  662                 oact->sa_flags = 0;
  663                 if (SIGISMEMBER(ps->ps_sigonstack, sig))
  664                         oact->sa_flags |= SA_ONSTACK;
  665                 if (!SIGISMEMBER(ps->ps_sigintr, sig))
  666                         oact->sa_flags |= SA_RESTART;
  667                 if (SIGISMEMBER(ps->ps_sigreset, sig))
  668                         oact->sa_flags |= SA_RESETHAND;
  669                 if (SIGISMEMBER(ps->ps_signodefer, sig))
  670                         oact->sa_flags |= SA_NODEFER;
  671                 if (SIGISMEMBER(ps->ps_siginfo, sig)) {
  672                         oact->sa_flags |= SA_SIGINFO;
  673                         oact->sa_sigaction =
  674                             (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)];
  675                 } else
  676                         oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
  677                 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP)
  678                         oact->sa_flags |= SA_NOCLDSTOP;
  679                 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT)
  680                         oact->sa_flags |= SA_NOCLDWAIT;
  681         }
  682         if (act) {
  683                 if ((sig == SIGKILL || sig == SIGSTOP) &&
  684                     act->sa_handler != SIG_DFL) {
  685                         mtx_unlock(&ps->ps_mtx);
  686                         PROC_UNLOCK(p);
  687                         return (EINVAL);
  688                 }
  689 
  690                 /*
  691                  * Change setting atomically.
  692                  */
  693 
  694                 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
  695                 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
  696                 if (act->sa_flags & SA_SIGINFO) {
  697                         ps->ps_sigact[_SIG_IDX(sig)] =
  698                             (__sighandler_t *)act->sa_sigaction;
  699                         SIGADDSET(ps->ps_siginfo, sig);
  700                 } else {
  701                         ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
  702                         SIGDELSET(ps->ps_siginfo, sig);
  703                 }
  704                 if (!(act->sa_flags & SA_RESTART))
  705                         SIGADDSET(ps->ps_sigintr, sig);
  706                 else
  707                         SIGDELSET(ps->ps_sigintr, sig);
  708                 if (act->sa_flags & SA_ONSTACK)
  709                         SIGADDSET(ps->ps_sigonstack, sig);
  710                 else
  711                         SIGDELSET(ps->ps_sigonstack, sig);
  712                 if (act->sa_flags & SA_RESETHAND)
  713                         SIGADDSET(ps->ps_sigreset, sig);
  714                 else
  715                         SIGDELSET(ps->ps_sigreset, sig);
  716                 if (act->sa_flags & SA_NODEFER)
  717                         SIGADDSET(ps->ps_signodefer, sig);
  718                 else
  719                         SIGDELSET(ps->ps_signodefer, sig);
  720                 if (sig == SIGCHLD) {
  721                         if (act->sa_flags & SA_NOCLDSTOP)
  722                                 ps->ps_flag |= PS_NOCLDSTOP;
  723                         else
  724                                 ps->ps_flag &= ~PS_NOCLDSTOP;
  725                         if (act->sa_flags & SA_NOCLDWAIT) {
  726                                 /*
  727                                  * Paranoia: since SA_NOCLDWAIT is implemented
  728                                  * by reparenting the dying child to PID 1 (and
  729                                  * trust it to reap the zombie), PID 1 itself
  730                                  * is forbidden to set SA_NOCLDWAIT.
  731                                  */
  732                                 if (p->p_pid == 1)
  733                                         ps->ps_flag &= ~PS_NOCLDWAIT;
  734                                 else
  735                                         ps->ps_flag |= PS_NOCLDWAIT;
  736                         } else
  737                                 ps->ps_flag &= ~PS_NOCLDWAIT;
  738                         if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
  739                                 ps->ps_flag |= PS_CLDSIGIGN;
  740                         else
  741                                 ps->ps_flag &= ~PS_CLDSIGIGN;
  742                 }
  743                 /*
  744                  * Set bit in ps_sigignore for signals that are set to SIG_IGN,
  745                  * and for signals set to SIG_DFL where the default is to
  746                  * ignore. However, don't put SIGCONT in ps_sigignore, as we
  747                  * have to restart the process.
  748                  */
  749                 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
  750                     (sigprop(sig) & SA_IGNORE &&
  751                      ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
  752                         /* never to be seen again */
  753                         sigqueue_delete_proc(p, sig);
  754                         if (sig != SIGCONT)
  755                                 /* easier in psignal */
  756                                 SIGADDSET(ps->ps_sigignore, sig);
  757                         SIGDELSET(ps->ps_sigcatch, sig);
  758                 } else {
  759                         SIGDELSET(ps->ps_sigignore, sig);
  760                         if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
  761                                 SIGDELSET(ps->ps_sigcatch, sig);
  762                         else
  763                                 SIGADDSET(ps->ps_sigcatch, sig);
  764                 }
  765 #ifdef COMPAT_FREEBSD4
  766                 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
  767                     ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
  768                     (flags & KSA_FREEBSD4) == 0)
  769                         SIGDELSET(ps->ps_freebsd4, sig);
  770                 else
  771                         SIGADDSET(ps->ps_freebsd4, sig);
  772 #endif
  773 #ifdef COMPAT_43
  774                 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
  775                     ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
  776                     (flags & KSA_OSIGSET) == 0)
  777                         SIGDELSET(ps->ps_osigset, sig);
  778                 else
  779                         SIGADDSET(ps->ps_osigset, sig);
  780 #endif
  781         }
  782         mtx_unlock(&ps->ps_mtx);
  783         PROC_UNLOCK(p);
  784         return (0);
  785 }
  786 
  787 #ifndef _SYS_SYSPROTO_H_
  788 struct sigaction_args {
  789         int     sig;
  790         struct  sigaction *act;
  791         struct  sigaction *oact;
  792 };
  793 #endif
  794 int
  795 sigaction(td, uap)
  796         struct thread *td;
  797         register struct sigaction_args *uap;
  798 {
  799         struct sigaction act, oact;
  800         register struct sigaction *actp, *oactp;
  801         int error;
  802 
  803         actp = (uap->act != NULL) ? &act : NULL;
  804         oactp = (uap->oact != NULL) ? &oact : NULL;
  805         if (actp) {
  806                 error = copyin(uap->act, actp, sizeof(act));
  807                 if (error)
  808                         return (error);
  809         }
  810         error = kern_sigaction(td, uap->sig, actp, oactp, 0);
  811         if (oactp && !error)
  812                 error = copyout(oactp, uap->oact, sizeof(oact));
  813         return (error);
  814 }
  815 
  816 #ifdef COMPAT_FREEBSD4
  817 #ifndef _SYS_SYSPROTO_H_
  818 struct freebsd4_sigaction_args {
  819         int     sig;
  820         struct  sigaction *act;
  821         struct  sigaction *oact;
  822 };
  823 #endif
  824 int
  825 freebsd4_sigaction(td, uap)
  826         struct thread *td;
  827         register struct freebsd4_sigaction_args *uap;
  828 {
  829         struct sigaction act, oact;
  830         register struct sigaction *actp, *oactp;
  831         int error;
  832 
  833 
  834         actp = (uap->act != NULL) ? &act : NULL;
  835         oactp = (uap->oact != NULL) ? &oact : NULL;
  836         if (actp) {
  837                 error = copyin(uap->act, actp, sizeof(act));
  838                 if (error)
  839                         return (error);
  840         }
  841         error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4);
  842         if (oactp && !error)
  843                 error = copyout(oactp, uap->oact, sizeof(oact));
  844         return (error);
  845 }
  846 #endif  /* COMAPT_FREEBSD4 */
  847 
  848 #ifdef COMPAT_43        /* XXX - COMPAT_FBSD3 */
  849 #ifndef _SYS_SYSPROTO_H_
  850 struct osigaction_args {
  851         int     signum;
  852         struct  osigaction *nsa;
  853         struct  osigaction *osa;
  854 };
  855 #endif
  856 int
  857 osigaction(td, uap)
  858         struct thread *td;
  859         register struct osigaction_args *uap;
  860 {
  861         struct osigaction sa;
  862         struct sigaction nsa, osa;
  863         register struct sigaction *nsap, *osap;
  864         int error;
  865 
  866         if (uap->signum <= 0 || uap->signum >= ONSIG)
  867                 return (EINVAL);
  868 
  869         nsap = (uap->nsa != NULL) ? &nsa : NULL;
  870         osap = (uap->osa != NULL) ? &osa : NULL;
  871 
  872         if (nsap) {
  873                 error = copyin(uap->nsa, &sa, sizeof(sa));
  874                 if (error)
  875                         return (error);
  876                 nsap->sa_handler = sa.sa_handler;
  877                 nsap->sa_flags = sa.sa_flags;
  878                 OSIG2SIG(sa.sa_mask, nsap->sa_mask);
  879         }
  880         error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
  881         if (osap && !error) {
  882                 sa.sa_handler = osap->sa_handler;
  883                 sa.sa_flags = osap->sa_flags;
  884                 SIG2OSIG(osap->sa_mask, sa.sa_mask);
  885                 error = copyout(&sa, uap->osa, sizeof(sa));
  886         }
  887         return (error);
  888 }
  889 
  890 #if !defined(__i386__)
  891 /* Avoid replicating the same stub everywhere */
  892 int
  893 osigreturn(td, uap)
  894         struct thread *td;
  895         struct osigreturn_args *uap;
  896 {
  897 
  898         return (nosys(td, (struct nosys_args *)uap));
  899 }
  900 #endif
  901 #endif /* COMPAT_43 */
  902 
  903 /*
  904  * Initialize signal state for process 0;
  905  * set to ignore signals that are ignored by default.
  906  */
  907 void
  908 siginit(p)
  909         struct proc *p;
  910 {
  911         register int i;
  912         struct sigacts *ps;
  913 
  914         PROC_LOCK(p);
  915         ps = p->p_sigacts;
  916         mtx_lock(&ps->ps_mtx);
  917         for (i = 1; i <= NSIG; i++)
  918                 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
  919                         SIGADDSET(ps->ps_sigignore, i);
  920         mtx_unlock(&ps->ps_mtx);
  921         PROC_UNLOCK(p);
  922 }
  923 
  924 /*
  925  * Reset signals for an exec of the specified process.
  926  */
  927 void
  928 execsigs(struct proc *p)
  929 {
  930         struct sigacts *ps;
  931         int sig;
  932         struct thread *td;
  933 
  934         /*
  935          * Reset caught signals.  Held signals remain held
  936          * through td_sigmask (unless they were caught,
  937          * and are now ignored by default).
  938          */
  939         PROC_LOCK_ASSERT(p, MA_OWNED);
  940         td = FIRST_THREAD_IN_PROC(p);
  941         ps = p->p_sigacts;
  942         mtx_lock(&ps->ps_mtx);
  943         while (SIGNOTEMPTY(ps->ps_sigcatch)) {
  944                 sig = sig_ffs(&ps->ps_sigcatch);
  945                 SIGDELSET(ps->ps_sigcatch, sig);
  946                 if (sigprop(sig) & SA_IGNORE) {
  947                         if (sig != SIGCONT)
  948                                 SIGADDSET(ps->ps_sigignore, sig);
  949                         sigqueue_delete_proc(p, sig);
  950                 }
  951                 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
  952         }
  953         /*
  954          * Reset stack state to the user stack.
  955          * Clear set of signals caught on the signal stack.
  956          */
  957         td->td_sigstk.ss_flags = SS_DISABLE;
  958         td->td_sigstk.ss_size = 0;
  959         td->td_sigstk.ss_sp = 0;
  960         td->td_pflags &= ~TDP_ALTSTACK;
  961         /*
  962          * Reset no zombies if child dies flag as Solaris does.
  963          */
  964         ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN);
  965         if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
  966                 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL;
  967         mtx_unlock(&ps->ps_mtx);
  968 }
  969 
  970 /*
  971  * kern_sigprocmask()
  972  *
  973  *      Manipulate signal mask.
  974  */
  975 int
  976 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset,
  977     int flags)
  978 {
  979         sigset_t new_block, oset1;
  980         struct proc *p;
  981         int error;
  982 
  983         p = td->td_proc;
  984         if (!(flags & SIGPROCMASK_PROC_LOCKED))
  985                 PROC_LOCK(p);
  986         if (oset != NULL)
  987                 *oset = td->td_sigmask;
  988 
  989         error = 0;
  990         SIGEMPTYSET(new_block);
  991         if (set != NULL) {
  992                 switch (how) {
  993                 case SIG_BLOCK:
  994                         SIG_CANTMASK(*set);
  995                         oset1 = td->td_sigmask;
  996                         SIGSETOR(td->td_sigmask, *set);
  997                         new_block = td->td_sigmask;
  998                         SIGSETNAND(new_block, oset1);
  999                         break;
 1000                 case SIG_UNBLOCK:
 1001                         SIGSETNAND(td->td_sigmask, *set);
 1002                         signotify(td);
 1003                         break;
 1004                 case SIG_SETMASK:
 1005                         SIG_CANTMASK(*set);
 1006                         oset1 = td->td_sigmask;
 1007                         if (flags & SIGPROCMASK_OLD)
 1008                                 SIGSETLO(td->td_sigmask, *set);
 1009                         else
 1010                                 td->td_sigmask = *set;
 1011                         new_block = td->td_sigmask;
 1012                         SIGSETNAND(new_block, oset1);
 1013                         signotify(td);
 1014                         break;
 1015                 default:
 1016                         error = EINVAL;
 1017                         break;
 1018                 }
 1019         }
 1020 
 1021         /*
 1022          * The new_block set contains signals that were not previously
 1023          * blocked, but are blocked now.
 1024          *
 1025          * In case we block any signal that was not previously blocked
 1026          * for td, and process has the signal pending, try to schedule
 1027          * signal delivery to some thread that does not block the signal,
 1028          * possibly waking it up.
 1029          */
 1030         if (p->p_numthreads != 1)
 1031                 reschedule_signals(p, new_block, flags);
 1032 
 1033         if (!(flags & SIGPROCMASK_PROC_LOCKED))
 1034                 PROC_UNLOCK(p);
 1035         return (error);
 1036 }
 1037 
 1038 #ifndef _SYS_SYSPROTO_H_
 1039 struct sigprocmask_args {
 1040         int     how;
 1041         const sigset_t *set;
 1042         sigset_t *oset;
 1043 };
 1044 #endif
 1045 int
 1046 sigprocmask(td, uap)
 1047         register struct thread *td;
 1048         struct sigprocmask_args *uap;
 1049 {
 1050         sigset_t set, oset;
 1051         sigset_t *setp, *osetp;
 1052         int error;
 1053 
 1054         setp = (uap->set != NULL) ? &set : NULL;
 1055         osetp = (uap->oset != NULL) ? &oset : NULL;
 1056         if (setp) {
 1057                 error = copyin(uap->set, setp, sizeof(set));
 1058                 if (error)
 1059                         return (error);
 1060         }
 1061         error = kern_sigprocmask(td, uap->how, setp, osetp, 0);
 1062         if (osetp && !error) {
 1063                 error = copyout(osetp, uap->oset, sizeof(oset));
 1064         }
 1065         return (error);
 1066 }
 1067 
 1068 #ifdef COMPAT_43        /* XXX - COMPAT_FBSD3 */
 1069 #ifndef _SYS_SYSPROTO_H_
 1070 struct osigprocmask_args {
 1071         int     how;
 1072         osigset_t mask;
 1073 };
 1074 #endif
 1075 int
 1076 osigprocmask(td, uap)
 1077         register struct thread *td;
 1078         struct osigprocmask_args *uap;
 1079 {
 1080         sigset_t set, oset;
 1081         int error;
 1082 
 1083         OSIG2SIG(uap->mask, set);
 1084         error = kern_sigprocmask(td, uap->how, &set, &oset, 1);
 1085         SIG2OSIG(oset, td->td_retval[0]);
 1086         return (error);
 1087 }
 1088 #endif /* COMPAT_43 */
 1089 
 1090 int
 1091 sigwait(struct thread *td, struct sigwait_args *uap)
 1092 {
 1093         ksiginfo_t ksi;
 1094         sigset_t set;
 1095         int error;
 1096 
 1097         error = copyin(uap->set, &set, sizeof(set));
 1098         if (error) {
 1099                 td->td_retval[0] = error;
 1100                 return (0);
 1101         }
 1102 
 1103         error = kern_sigtimedwait(td, set, &ksi, NULL);
 1104         if (error) {
 1105                 if (error == ERESTART)
 1106                         return (error);
 1107                 td->td_retval[0] = error;
 1108                 return (0);
 1109         }
 1110 
 1111         error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo));
 1112         td->td_retval[0] = error;
 1113         return (0);
 1114 }
 1115 
 1116 int
 1117 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap)
 1118 {
 1119         struct timespec ts;
 1120         struct timespec *timeout;
 1121         sigset_t set;
 1122         ksiginfo_t ksi;
 1123         int error;
 1124 
 1125         if (uap->timeout) {
 1126                 error = copyin(uap->timeout, &ts, sizeof(ts));
 1127                 if (error)
 1128                         return (error);
 1129 
 1130                 timeout = &ts;
 1131         } else
 1132                 timeout = NULL;
 1133 
 1134         error = copyin(uap->set, &set, sizeof(set));
 1135         if (error)
 1136                 return (error);
 1137 
 1138         error = kern_sigtimedwait(td, set, &ksi, timeout);
 1139         if (error)
 1140                 return (error);
 1141 
 1142         if (uap->info)
 1143                 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t));
 1144 
 1145         if (error == 0)
 1146                 td->td_retval[0] = ksi.ksi_signo;
 1147         return (error);
 1148 }
 1149 
 1150 int
 1151 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap)
 1152 {
 1153         ksiginfo_t ksi;
 1154         sigset_t set;
 1155         int error;
 1156 
 1157         error = copyin(uap->set, &set, sizeof(set));
 1158         if (error)
 1159                 return (error);
 1160 
 1161         error = kern_sigtimedwait(td, set, &ksi, NULL);
 1162         if (error)
 1163                 return (error);
 1164 
 1165         if (uap->info)
 1166                 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t));
 1167         
 1168         if (error == 0)
 1169                 td->td_retval[0] = ksi.ksi_signo;
 1170         return (error);
 1171 }
 1172 
 1173 int
 1174 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi,
 1175         struct timespec *timeout)
 1176 {
 1177         struct sigacts *ps;
 1178         sigset_t savedmask;
 1179         struct proc *p;
 1180         int error, sig, hz, i, timevalid = 0;
 1181         struct timespec rts, ets, ts;
 1182         struct timeval tv;
 1183 
 1184         p = td->td_proc;
 1185         error = 0;
 1186         sig = 0;
 1187         ets.tv_sec = 0;
 1188         ets.tv_nsec = 0;
 1189         SIG_CANTMASK(waitset);
 1190 
 1191         PROC_LOCK(p);
 1192         ps = p->p_sigacts;
 1193         savedmask = td->td_sigmask;
 1194         if (timeout) {
 1195                 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) {
 1196                         timevalid = 1;
 1197                         getnanouptime(&rts);
 1198                         ets = rts;
 1199                         timespecadd(&ets, timeout);
 1200                 }
 1201         }
 1202 
 1203 restart:
 1204         for (i = 1; i <= _SIG_MAXSIG; ++i) {
 1205                 if (!SIGISMEMBER(waitset, i))
 1206                         continue;
 1207                 if (!SIGISMEMBER(td->td_sigqueue.sq_signals, i)) {
 1208                         if (SIGISMEMBER(p->p_sigqueue.sq_signals, i)) {
 1209                                 sigqueue_move(&p->p_sigqueue,
 1210                                         &td->td_sigqueue, i);
 1211                         } else
 1212                                 continue;
 1213                 }
 1214 
 1215                 SIGFILLSET(td->td_sigmask);
 1216                 SIG_CANTMASK(td->td_sigmask);
 1217                 SIGDELSET(td->td_sigmask, i);
 1218                 mtx_lock(&ps->ps_mtx);
 1219                 sig = cursig(td, SIG_STOP_ALLOWED);
 1220                 mtx_unlock(&ps->ps_mtx);
 1221                 if (sig)
 1222                         goto out;
 1223                 else {
 1224                         /*
 1225                          * Because cursig() may have stopped current thread,
 1226                          * after it is resumed, things may have already been 
 1227                          * changed, it should rescan any pending signals.
 1228                          */
 1229                         goto restart;
 1230                 }
 1231         }
 1232 
 1233         if (error)
 1234                 goto out;
 1235 
 1236         /*
 1237          * POSIX says this must be checked after looking for pending
 1238          * signals.
 1239          */
 1240         if (timeout) {
 1241                 if (!timevalid) {
 1242                         error = EINVAL;
 1243                         goto out;
 1244                 }
 1245                 getnanouptime(&rts);
 1246                 if (timespeccmp(&rts, &ets, >=)) {
 1247                         error = EAGAIN;
 1248                         goto out;
 1249                 }
 1250                 ts = ets;
 1251                 timespecsub(&ts, &rts);
 1252                 TIMESPEC_TO_TIMEVAL(&tv, &ts);
 1253                 hz = tvtohz(&tv);
 1254         } else
 1255                 hz = 0;
 1256 
 1257         td->td_sigmask = savedmask;
 1258         SIGSETNAND(td->td_sigmask, waitset);
 1259         signotify(td);
 1260         error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz);
 1261         if (timeout) {
 1262                 if (error == ERESTART) {
 1263                         /* timeout can not be restarted. */
 1264                         error = EINTR;
 1265                 } else if (error == EAGAIN) {
 1266                         /* will calculate timeout by ourself. */
 1267                         error = 0;
 1268                 }
 1269         }
 1270         goto restart;
 1271 
 1272 out:
 1273         td->td_sigmask = savedmask;
 1274         signotify(td);
 1275         if (sig) {
 1276                 ksiginfo_init(ksi);
 1277                 sigqueue_get(&td->td_sigqueue, sig, ksi);
 1278                 ksi->ksi_signo = sig;
 1279 
 1280                 SDT_PROBE(proc, kernel, , signal_clear, sig, ksi, 0, 0, 0);
 1281                 
 1282                 if (ksi->ksi_code == SI_TIMER)
 1283                         itimer_accept(p, ksi->ksi_timerid, ksi);
 1284                 error = 0;
 1285 
 1286 #ifdef KTRACE
 1287                 if (KTRPOINT(td, KTR_PSIG)) {
 1288                         sig_t action;
 1289 
 1290                         mtx_lock(&ps->ps_mtx);
 1291                         action = ps->ps_sigact[_SIG_IDX(sig)];
 1292                         mtx_unlock(&ps->ps_mtx);
 1293                         ktrpsig(sig, action, &td->td_sigmask, 0);
 1294                 }
 1295 #endif
 1296                 if (sig == SIGKILL)
 1297                         sigexit(td, sig);
 1298         }
 1299         PROC_UNLOCK(p);
 1300         return (error);
 1301 }
 1302 
 1303 #ifndef _SYS_SYSPROTO_H_
 1304 struct sigpending_args {
 1305         sigset_t        *set;
 1306 };
 1307 #endif
 1308 int
 1309 sigpending(td, uap)
 1310         struct thread *td;
 1311         struct sigpending_args *uap;
 1312 {
 1313         struct proc *p = td->td_proc;
 1314         sigset_t pending;
 1315 
 1316         PROC_LOCK(p);
 1317         pending = p->p_sigqueue.sq_signals;
 1318         SIGSETOR(pending, td->td_sigqueue.sq_signals);
 1319         PROC_UNLOCK(p);
 1320         return (copyout(&pending, uap->set, sizeof(sigset_t)));
 1321 }
 1322 
 1323 #ifdef COMPAT_43        /* XXX - COMPAT_FBSD3 */
 1324 #ifndef _SYS_SYSPROTO_H_
 1325 struct osigpending_args {
 1326         int     dummy;
 1327 };
 1328 #endif
 1329 int
 1330 osigpending(td, uap)
 1331         struct thread *td;
 1332         struct osigpending_args *uap;
 1333 {
 1334         struct proc *p = td->td_proc;
 1335         sigset_t pending;
 1336 
 1337         PROC_LOCK(p);
 1338         pending = p->p_sigqueue.sq_signals;
 1339         SIGSETOR(pending, td->td_sigqueue.sq_signals);
 1340         PROC_UNLOCK(p);
 1341         SIG2OSIG(pending, td->td_retval[0]);
 1342         return (0);
 1343 }
 1344 #endif /* COMPAT_43 */
 1345 
 1346 #if defined(COMPAT_43)
 1347 /*
 1348  * Generalized interface signal handler, 4.3-compatible.
 1349  */
 1350 #ifndef _SYS_SYSPROTO_H_
 1351 struct osigvec_args {
 1352         int     signum;
 1353         struct  sigvec *nsv;
 1354         struct  sigvec *osv;
 1355 };
 1356 #endif
 1357 /* ARGSUSED */
 1358 int
 1359 osigvec(td, uap)
 1360         struct thread *td;
 1361         register struct osigvec_args *uap;
 1362 {
 1363         struct sigvec vec;
 1364         struct sigaction nsa, osa;
 1365         register struct sigaction *nsap, *osap;
 1366         int error;
 1367 
 1368         if (uap->signum <= 0 || uap->signum >= ONSIG)
 1369                 return (EINVAL);
 1370         nsap = (uap->nsv != NULL) ? &nsa : NULL;
 1371         osap = (uap->osv != NULL) ? &osa : NULL;
 1372         if (nsap) {
 1373                 error = copyin(uap->nsv, &vec, sizeof(vec));
 1374                 if (error)
 1375                         return (error);
 1376                 nsap->sa_handler = vec.sv_handler;
 1377                 OSIG2SIG(vec.sv_mask, nsap->sa_mask);
 1378                 nsap->sa_flags = vec.sv_flags;
 1379                 nsap->sa_flags ^= SA_RESTART;   /* opposite of SV_INTERRUPT */
 1380         }
 1381         error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
 1382         if (osap && !error) {
 1383                 vec.sv_handler = osap->sa_handler;
 1384                 SIG2OSIG(osap->sa_mask, vec.sv_mask);
 1385                 vec.sv_flags = osap->sa_flags;
 1386                 vec.sv_flags &= ~SA_NOCLDWAIT;
 1387                 vec.sv_flags ^= SA_RESTART;
 1388                 error = copyout(&vec, uap->osv, sizeof(vec));
 1389         }
 1390         return (error);
 1391 }
 1392 
 1393 #ifndef _SYS_SYSPROTO_H_
 1394 struct osigblock_args {
 1395         int     mask;
 1396 };
 1397 #endif
 1398 int
 1399 osigblock(td, uap)
 1400         register struct thread *td;
 1401         struct osigblock_args *uap;
 1402 {
 1403         sigset_t set, oset;
 1404 
 1405         OSIG2SIG(uap->mask, set);
 1406         kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0);
 1407         SIG2OSIG(oset, td->td_retval[0]);
 1408         return (0);
 1409 }
 1410 
 1411 #ifndef _SYS_SYSPROTO_H_
 1412 struct osigsetmask_args {
 1413         int     mask;
 1414 };
 1415 #endif
 1416 int
 1417 osigsetmask(td, uap)
 1418         struct thread *td;
 1419         struct osigsetmask_args *uap;
 1420 {
 1421         sigset_t set, oset;
 1422 
 1423         OSIG2SIG(uap->mask, set);
 1424         kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0);
 1425         SIG2OSIG(oset, td->td_retval[0]);
 1426         return (0);
 1427 }
 1428 #endif /* COMPAT_43 */
 1429 
 1430 /*
 1431  * Suspend calling thread until signal, providing mask to be set in the
 1432  * meantime. 
 1433  */
 1434 #ifndef _SYS_SYSPROTO_H_
 1435 struct sigsuspend_args {
 1436         const sigset_t *sigmask;
 1437 };
 1438 #endif
 1439 /* ARGSUSED */
 1440 int
 1441 sigsuspend(td, uap)
 1442         struct thread *td;
 1443         struct sigsuspend_args *uap;
 1444 {
 1445         sigset_t mask;
 1446         int error;
 1447 
 1448         error = copyin(uap->sigmask, &mask, sizeof(mask));
 1449         if (error)
 1450                 return (error);
 1451         return (kern_sigsuspend(td, mask));
 1452 }
 1453 
 1454 int
 1455 kern_sigsuspend(struct thread *td, sigset_t mask)
 1456 {
 1457         struct proc *p = td->td_proc;
 1458         int has_sig, sig;
 1459 
 1460         /*
 1461          * When returning from sigsuspend, we want
 1462          * the old mask to be restored after the
 1463          * signal handler has finished.  Thus, we
 1464          * save it here and mark the sigacts structure
 1465          * to indicate this.
 1466          */
 1467         PROC_LOCK(p);
 1468         kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask,
 1469             SIGPROCMASK_PROC_LOCKED);
 1470         td->td_pflags |= TDP_OLDMASK;
 1471 
 1472         /*
 1473          * Process signals now. Otherwise, we can get spurious wakeup
 1474          * due to signal entered process queue, but delivered to other
 1475          * thread. But sigsuspend should return only on signal
 1476          * delivery.
 1477          */
 1478         (p->p_sysent->sv_set_syscall_retval)(td, EINTR);
 1479         for (has_sig = 0; !has_sig;) {
 1480                 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause",
 1481                         0) == 0)
 1482                         /* void */;
 1483                 thread_suspend_check(0);
 1484                 mtx_lock(&p->p_sigacts->ps_mtx);
 1485                 while ((sig = cursig(td, SIG_STOP_ALLOWED)) != 0)
 1486                         has_sig += postsig(sig);
 1487                 mtx_unlock(&p->p_sigacts->ps_mtx);
 1488         }
 1489         PROC_UNLOCK(p);
 1490         return (EJUSTRETURN);
 1491 }
 1492 
 1493 #ifdef COMPAT_43        /* XXX - COMPAT_FBSD3 */
 1494 /*
 1495  * Compatibility sigsuspend call for old binaries.  Note nonstandard calling
 1496  * convention: libc stub passes mask, not pointer, to save a copyin.
 1497  */
 1498 #ifndef _SYS_SYSPROTO_H_
 1499 struct osigsuspend_args {
 1500         osigset_t mask;
 1501 };
 1502 #endif
 1503 /* ARGSUSED */
 1504 int
 1505 osigsuspend(td, uap)
 1506         struct thread *td;
 1507         struct osigsuspend_args *uap;
 1508 {
 1509         sigset_t mask;
 1510 
 1511         OSIG2SIG(uap->mask, mask);
 1512         return (kern_sigsuspend(td, mask));
 1513 }
 1514 #endif /* COMPAT_43 */
 1515 
 1516 #if defined(COMPAT_43)
 1517 #ifndef _SYS_SYSPROTO_H_
 1518 struct osigstack_args {
 1519         struct  sigstack *nss;
 1520         struct  sigstack *oss;
 1521 };
 1522 #endif
 1523 /* ARGSUSED */
 1524 int
 1525 osigstack(td, uap)
 1526         struct thread *td;
 1527         register struct osigstack_args *uap;
 1528 {
 1529         struct sigstack nss, oss;
 1530         int error = 0;
 1531 
 1532         if (uap->nss != NULL) {
 1533                 error = copyin(uap->nss, &nss, sizeof(nss));
 1534                 if (error)
 1535                         return (error);
 1536         }
 1537         oss.ss_sp = td->td_sigstk.ss_sp;
 1538         oss.ss_onstack = sigonstack(cpu_getstack(td));
 1539         if (uap->nss != NULL) {
 1540                 td->td_sigstk.ss_sp = nss.ss_sp;
 1541                 td->td_sigstk.ss_size = 0;
 1542                 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK;
 1543                 td->td_pflags |= TDP_ALTSTACK;
 1544         }
 1545         if (uap->oss != NULL)
 1546                 error = copyout(&oss, uap->oss, sizeof(oss));
 1547 
 1548         return (error);
 1549 }
 1550 #endif /* COMPAT_43 */
 1551 
 1552 #ifndef _SYS_SYSPROTO_H_
 1553 struct sigaltstack_args {
 1554         stack_t *ss;
 1555         stack_t *oss;
 1556 };
 1557 #endif
 1558 /* ARGSUSED */
 1559 int
 1560 sigaltstack(td, uap)
 1561         struct thread *td;
 1562         register struct sigaltstack_args *uap;
 1563 {
 1564         stack_t ss, oss;
 1565         int error;
 1566 
 1567         if (uap->ss != NULL) {
 1568                 error = copyin(uap->ss, &ss, sizeof(ss));
 1569                 if (error)
 1570                         return (error);
 1571         }
 1572         error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL,
 1573             (uap->oss != NULL) ? &oss : NULL);
 1574         if (error)
 1575                 return (error);
 1576         if (uap->oss != NULL)
 1577                 error = copyout(&oss, uap->oss, sizeof(stack_t));
 1578         return (error);
 1579 }
 1580 
 1581 int
 1582 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss)
 1583 {
 1584         struct proc *p = td->td_proc;
 1585         int oonstack;
 1586 
 1587         oonstack = sigonstack(cpu_getstack(td));
 1588 
 1589         if (oss != NULL) {
 1590                 *oss = td->td_sigstk;
 1591                 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK)
 1592                     ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
 1593         }
 1594 
 1595         if (ss != NULL) {
 1596                 if (oonstack)
 1597                         return (EPERM);
 1598                 if ((ss->ss_flags & ~SS_DISABLE) != 0)
 1599                         return (EINVAL);
 1600                 if (!(ss->ss_flags & SS_DISABLE)) {
 1601                         if (ss->ss_size < p->p_sysent->sv_minsigstksz)
 1602                                 return (ENOMEM);
 1603 
 1604                         td->td_sigstk = *ss;
 1605                         td->td_pflags |= TDP_ALTSTACK;
 1606                 } else {
 1607                         td->td_pflags &= ~TDP_ALTSTACK;
 1608                 }
 1609         }
 1610         return (0);
 1611 }
 1612 
 1613 /*
 1614  * Common code for kill process group/broadcast kill.
 1615  * cp is calling process.
 1616  */
 1617 static int
 1618 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi)
 1619 {
 1620         struct proc *p;
 1621         struct pgrp *pgrp;
 1622         int nfound = 0;
 1623 
 1624         if (all) {
 1625                 /*
 1626                  * broadcast
 1627                  */
 1628                 sx_slock(&allproc_lock);
 1629                 FOREACH_PROC_IN_SYSTEM(p) {
 1630                         PROC_LOCK(p);
 1631                         if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
 1632                             p == td->td_proc || p->p_state == PRS_NEW) {
 1633                                 PROC_UNLOCK(p);
 1634                                 continue;
 1635                         }
 1636                         if (p_cansignal(td, p, sig) == 0) {
 1637                                 nfound++;
 1638                                 if (sig)
 1639                                         pksignal(p, sig, ksi);
 1640                         }
 1641                         PROC_UNLOCK(p);
 1642                 }
 1643                 sx_sunlock(&allproc_lock);
 1644         } else {
 1645                 sx_slock(&proctree_lock);
 1646                 if (pgid == 0) {
 1647                         /*
 1648                          * zero pgid means send to my process group.
 1649                          */
 1650                         pgrp = td->td_proc->p_pgrp;
 1651                         PGRP_LOCK(pgrp);
 1652                 } else {
 1653                         pgrp = pgfind(pgid);
 1654                         if (pgrp == NULL) {
 1655                                 sx_sunlock(&proctree_lock);
 1656                                 return (ESRCH);
 1657                         }
 1658                 }
 1659                 sx_sunlock(&proctree_lock);
 1660                 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
 1661                         PROC_LOCK(p);         
 1662                         if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
 1663                                 p->p_state == PRS_NEW ) {
 1664                                 PROC_UNLOCK(p);
 1665                                 continue;
 1666                         }
 1667                         if (p_cansignal(td, p, sig) == 0) {
 1668                                 nfound++;
 1669                                 if (sig)
 1670                                         pksignal(p, sig, ksi);
 1671                         }
 1672                         PROC_UNLOCK(p);
 1673                 }
 1674                 PGRP_UNLOCK(pgrp);
 1675         }
 1676         return (nfound ? 0 : ESRCH);
 1677 }
 1678 
 1679 #ifndef _SYS_SYSPROTO_H_
 1680 struct kill_args {
 1681         int     pid;
 1682         int     signum;
 1683 };
 1684 #endif
 1685 /* ARGSUSED */
 1686 int
 1687 kill(struct thread *td, struct kill_args *uap)
 1688 {
 1689         ksiginfo_t ksi;
 1690         struct proc *p;
 1691         int error;
 1692 
 1693         AUDIT_ARG_SIGNUM(uap->signum);
 1694         AUDIT_ARG_PID(uap->pid);
 1695         if ((u_int)uap->signum > _SIG_MAXSIG)
 1696                 return (EINVAL);
 1697 
 1698         ksiginfo_init(&ksi);
 1699         ksi.ksi_signo = uap->signum;
 1700         ksi.ksi_code = SI_USER;
 1701         ksi.ksi_pid = td->td_proc->p_pid;
 1702         ksi.ksi_uid = td->td_ucred->cr_ruid;
 1703 
 1704         if (uap->pid > 0) {
 1705                 /* kill single process */
 1706                 if ((p = pfind(uap->pid)) == NULL) {
 1707                         if ((p = zpfind(uap->pid)) == NULL)
 1708                                 return (ESRCH);
 1709                 }
 1710                 AUDIT_ARG_PROCESS(p);
 1711                 error = p_cansignal(td, p, uap->signum);
 1712                 if (error == 0 && uap->signum)
 1713                         pksignal(p, uap->signum, &ksi);
 1714                 PROC_UNLOCK(p);
 1715                 return (error);
 1716         }
 1717         switch (uap->pid) {
 1718         case -1:                /* broadcast signal */
 1719                 return (killpg1(td, uap->signum, 0, 1, &ksi));
 1720         case 0:                 /* signal own process group */
 1721                 return (killpg1(td, uap->signum, 0, 0, &ksi));
 1722         default:                /* negative explicit process group */
 1723                 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi));
 1724         }
 1725         /* NOTREACHED */
 1726 }
 1727 
 1728 #if defined(COMPAT_43)
 1729 #ifndef _SYS_SYSPROTO_H_
 1730 struct okillpg_args {
 1731         int     pgid;
 1732         int     signum;
 1733 };
 1734 #endif
 1735 /* ARGSUSED */
 1736 int
 1737 okillpg(struct thread *td, struct okillpg_args *uap)
 1738 {
 1739         ksiginfo_t ksi;
 1740 
 1741         AUDIT_ARG_SIGNUM(uap->signum);
 1742         AUDIT_ARG_PID(uap->pgid);
 1743         if ((u_int)uap->signum > _SIG_MAXSIG)
 1744                 return (EINVAL);
 1745 
 1746         ksiginfo_init(&ksi);
 1747         ksi.ksi_signo = uap->signum;
 1748         ksi.ksi_code = SI_USER;
 1749         ksi.ksi_pid = td->td_proc->p_pid;
 1750         ksi.ksi_uid = td->td_ucred->cr_ruid;
 1751         return (killpg1(td, uap->signum, uap->pgid, 0, &ksi));
 1752 }
 1753 #endif /* COMPAT_43 */
 1754 
 1755 #ifndef _SYS_SYSPROTO_H_
 1756 struct sigqueue_args {
 1757         pid_t pid;
 1758         int signum;
 1759         /* union sigval */ void *value;
 1760 };
 1761 #endif
 1762 int
 1763 sigqueue(struct thread *td, struct sigqueue_args *uap)
 1764 {
 1765         ksiginfo_t ksi;
 1766         struct proc *p;
 1767         int error;
 1768 
 1769         if ((u_int)uap->signum > _SIG_MAXSIG)
 1770                 return (EINVAL);
 1771 
 1772         /*
 1773          * Specification says sigqueue can only send signal to
 1774          * single process.
 1775          */
 1776         if (uap->pid <= 0)
 1777                 return (EINVAL);
 1778 
 1779         if ((p = pfind(uap->pid)) == NULL) {
 1780                 if ((p = zpfind(uap->pid)) == NULL)
 1781                         return (ESRCH);
 1782         }
 1783         error = p_cansignal(td, p, uap->signum);
 1784         if (error == 0 && uap->signum != 0) {
 1785                 ksiginfo_init(&ksi);
 1786                 ksi.ksi_flags = KSI_SIGQ;
 1787                 ksi.ksi_signo = uap->signum;
 1788                 ksi.ksi_code = SI_QUEUE;
 1789                 ksi.ksi_pid = td->td_proc->p_pid;
 1790                 ksi.ksi_uid = td->td_ucred->cr_ruid;
 1791                 ksi.ksi_value.sival_ptr = uap->value;
 1792                 error = tdsignal(p, NULL, ksi.ksi_signo, &ksi);
 1793         }
 1794         PROC_UNLOCK(p);
 1795         return (error);
 1796 }
 1797 
 1798 /*
 1799  * Send a signal to a process group.
 1800  */
 1801 void
 1802 gsignal(int pgid, int sig, ksiginfo_t *ksi)
 1803 {
 1804         struct pgrp *pgrp;
 1805 
 1806         if (pgid != 0) {
 1807                 sx_slock(&proctree_lock);
 1808                 pgrp = pgfind(pgid);
 1809                 sx_sunlock(&proctree_lock);
 1810                 if (pgrp != NULL) {
 1811                         pgsignal(pgrp, sig, 0, ksi);
 1812                         PGRP_UNLOCK(pgrp);
 1813                 }
 1814         }
 1815 }
 1816 
 1817 /*
 1818  * Send a signal to a process group.  If checktty is 1,
 1819  * limit to members which have a controlling terminal.
 1820  */
 1821 void
 1822 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi)
 1823 {
 1824         struct proc *p;
 1825 
 1826         if (pgrp) {
 1827                 PGRP_LOCK_ASSERT(pgrp, MA_OWNED);
 1828                 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
 1829                         PROC_LOCK(p);
 1830                         if (checkctty == 0 || p->p_flag & P_CONTROLT)
 1831                                 pksignal(p, sig, ksi);
 1832                         PROC_UNLOCK(p);
 1833                 }
 1834         }
 1835 }
 1836 
 1837 /*
 1838  * Send a signal caused by a trap to the current thread.  If it will be
 1839  * caught immediately, deliver it with correct code.  Otherwise, post it
 1840  * normally.
 1841  */
 1842 void
 1843 trapsignal(struct thread *td, ksiginfo_t *ksi)
 1844 {
 1845         struct sigacts *ps;
 1846         sigset_t mask;
 1847         struct proc *p;
 1848         int sig;
 1849         int code;
 1850 
 1851         p = td->td_proc;
 1852         sig = ksi->ksi_signo;
 1853         code = ksi->ksi_code;
 1854         KASSERT(_SIG_VALID(sig), ("invalid signal"));
 1855 
 1856         PROC_LOCK(p);
 1857         ps = p->p_sigacts;
 1858         mtx_lock(&ps->ps_mtx);
 1859         if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) &&
 1860             !SIGISMEMBER(td->td_sigmask, sig)) {
 1861                 td->td_ru.ru_nsignals++;
 1862 #ifdef KTRACE
 1863                 if (KTRPOINT(curthread, KTR_PSIG))
 1864                         ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)],
 1865                             &td->td_sigmask, code);
 1866 #endif
 1867                 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 
 1868                                 ksi, &td->td_sigmask);
 1869                 mask = ps->ps_catchmask[_SIG_IDX(sig)];
 1870                 if (!SIGISMEMBER(ps->ps_signodefer, sig))
 1871                         SIGADDSET(mask, sig);
 1872                 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL,
 1873                     SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED);
 1874                 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
 1875                         /*
 1876                          * See kern_sigaction() for origin of this code.
 1877                          */
 1878                         SIGDELSET(ps->ps_sigcatch, sig);
 1879                         if (sig != SIGCONT &&
 1880                             sigprop(sig) & SA_IGNORE)
 1881                                 SIGADDSET(ps->ps_sigignore, sig);
 1882                         ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
 1883                 }
 1884                 mtx_unlock(&ps->ps_mtx);
 1885         } else {
 1886                 /*
 1887                  * Avoid a possible infinite loop if the thread
 1888                  * masking the signal or process is ignoring the
 1889                  * signal.
 1890                  */
 1891                 if (kern_forcesigexit &&
 1892                     (SIGISMEMBER(td->td_sigmask, sig) ||
 1893                      ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) {
 1894                         SIGDELSET(td->td_sigmask, sig);
 1895                         SIGDELSET(ps->ps_sigcatch, sig);
 1896                         SIGDELSET(ps->ps_sigignore, sig);
 1897                         ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
 1898                 }
 1899                 mtx_unlock(&ps->ps_mtx);
 1900                 p->p_code = code;       /* XXX for core dump/debugger */
 1901                 p->p_sig = sig;         /* XXX to verify code */
 1902                 tdsignal(p, td, sig, ksi);
 1903         }
 1904         PROC_UNLOCK(p);
 1905 }
 1906 
 1907 static struct thread *
 1908 sigtd(struct proc *p, int sig, int prop)
 1909 {
 1910         struct thread *td, *signal_td;
 1911 
 1912         PROC_LOCK_ASSERT(p, MA_OWNED);
 1913 
 1914         /*
 1915          * Check if current thread can handle the signal without
 1916          * switching context to another thread.
 1917          */
 1918         if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig))
 1919                 return (curthread);
 1920         signal_td = NULL;
 1921         FOREACH_THREAD_IN_PROC(p, td) {
 1922                 if (!SIGISMEMBER(td->td_sigmask, sig)) {
 1923                         signal_td = td;
 1924                         break;
 1925                 }
 1926         }
 1927         if (signal_td == NULL)
 1928                 signal_td = FIRST_THREAD_IN_PROC(p);
 1929         return (signal_td);
 1930 }
 1931 
 1932 /*
 1933  * Send the signal to the process.  If the signal has an action, the action
 1934  * is usually performed by the target process rather than the caller; we add
 1935  * the signal to the set of pending signals for the process.
 1936  *
 1937  * Exceptions:
 1938  *   o When a stop signal is sent to a sleeping process that takes the
 1939  *     default action, the process is stopped without awakening it.
 1940  *   o SIGCONT restarts stopped processes (or puts them back to sleep)
 1941  *     regardless of the signal action (eg, blocked or ignored).
 1942  *
 1943  * Other ignored signals are discarded immediately.
 1944  * 
 1945  * NB: This function may be entered from the debugger via the "kill" DDB
 1946  * command.  There is little that can be done to mitigate the possibly messy
 1947  * side effects of this unwise possibility.
 1948  */
 1949 void
 1950 psignal(struct proc *p, int sig)
 1951 {
 1952         ksiginfo_t ksi;
 1953 
 1954         ksiginfo_init(&ksi);
 1955         ksi.ksi_signo = sig;
 1956         ksi.ksi_code = SI_KERNEL;
 1957         (void) tdsignal(p, NULL, sig, &ksi);
 1958 }
 1959 
 1960 void
 1961 pksignal(struct proc *p, int sig, ksiginfo_t *ksi)
 1962 {
 1963 
 1964         (void) tdsignal(p, NULL, sig, ksi);
 1965 }
 1966 
 1967 int
 1968 psignal_event(struct proc *p, struct sigevent *sigev, ksiginfo_t *ksi)
 1969 {
 1970         struct thread *td = NULL;
 1971 
 1972         PROC_LOCK_ASSERT(p, MA_OWNED);
 1973 
 1974         KASSERT(!KSI_ONQ(ksi), ("psignal_event: ksi on queue"));
 1975 
 1976         /*
 1977          * ksi_code and other fields should be set before
 1978          * calling this function.
 1979          */
 1980         ksi->ksi_signo = sigev->sigev_signo;
 1981         ksi->ksi_value = sigev->sigev_value;
 1982         if (sigev->sigev_notify == SIGEV_THREAD_ID) {
 1983                 td = thread_find(p, sigev->sigev_notify_thread_id);
 1984                 if (td == NULL)
 1985                         return (ESRCH);
 1986         }
 1987         return (tdsignal(p, td, ksi->ksi_signo, ksi));
 1988 }
 1989 
 1990 void
 1991 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi)
 1992 {
 1993         ksiginfo_t ksi_thunk;
 1994 
 1995         /*
 1996          * If ksi is NULL, use ksi_thunk and provide semantics
 1997          * identical to tdsignal() in 9.0+.
 1998          */
 1999         if (ksi == NULL) {
 2000                 ksi = &ksi_thunk;
 2001                 ksiginfo_init(ksi);
 2002                 ksi->ksi_signo = sig;
 2003                 ksi->ksi_code = SI_KERNEL;
 2004         }
 2005         (void) tdsignal(td->td_proc, td, sig, ksi);
 2006 }
 2007 
 2008 int
 2009 tdsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi)
 2010 {
 2011         sig_t action;
 2012         sigqueue_t *sigqueue;
 2013         int prop;
 2014         struct sigacts *ps;
 2015         int intrval;
 2016         int ret = 0;
 2017         int wakeup_swapper;
 2018 
 2019         PROC_LOCK_ASSERT(p, MA_OWNED);
 2020 
 2021         if (!_SIG_VALID(sig))
 2022                 panic("tdsignal(): invalid signal %d", sig);
 2023 
 2024         KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("tdsignal: ksi on queue"));
 2025 
 2026         /*
 2027          * IEEE Std 1003.1-2001: return success when killing a zombie.
 2028          */
 2029         if (p->p_state == PRS_ZOMBIE) {
 2030                 if (ksi && (ksi->ksi_flags & KSI_INS))
 2031                         ksiginfo_tryfree(ksi);
 2032                 return (ret);
 2033         }
 2034 
 2035         ps = p->p_sigacts;
 2036         KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig);
 2037         prop = sigprop(sig);
 2038 
 2039         if (td == NULL) {
 2040                 td = sigtd(p, sig, prop);
 2041                 sigqueue = &p->p_sigqueue;
 2042         } else {
 2043                 KASSERT(td->td_proc == p, ("invalid thread"));
 2044                 sigqueue = &td->td_sigqueue;
 2045         }
 2046 
 2047         SDT_PROBE(proc, kernel, , signal_send, td, p, sig, 0, 0 );
 2048 
 2049         /*
 2050          * If the signal is being ignored,
 2051          * then we forget about it immediately.
 2052          * (Note: we don't set SIGCONT in ps_sigignore,
 2053          * and if it is set to SIG_IGN,
 2054          * action will be SIG_DFL here.)
 2055          */
 2056         mtx_lock(&ps->ps_mtx);
 2057         if (SIGISMEMBER(ps->ps_sigignore, sig)) {
 2058                 SDT_PROBE(proc, kernel, , signal_discard, ps, td, sig, 0, 0 );
 2059 
 2060                 mtx_unlock(&ps->ps_mtx);
 2061                 if (ksi && (ksi->ksi_flags & KSI_INS))
 2062                         ksiginfo_tryfree(ksi);
 2063                 return (ret);
 2064         }
 2065         if (SIGISMEMBER(td->td_sigmask, sig))
 2066                 action = SIG_HOLD;
 2067         else if (SIGISMEMBER(ps->ps_sigcatch, sig))
 2068                 action = SIG_CATCH;
 2069         else
 2070                 action = SIG_DFL;
 2071         if (SIGISMEMBER(ps->ps_sigintr, sig))
 2072                 intrval = EINTR;
 2073         else
 2074                 intrval = ERESTART;
 2075         mtx_unlock(&ps->ps_mtx);
 2076 
 2077         if (prop & SA_CONT)
 2078                 sigqueue_delete_stopmask_proc(p);
 2079         else if (prop & SA_STOP) {
 2080                 /*
 2081                  * If sending a tty stop signal to a member of an orphaned
 2082                  * process group, discard the signal here if the action
 2083                  * is default; don't stop the process below if sleeping,
 2084                  * and don't clear any pending SIGCONT.
 2085                  */
 2086                 if ((prop & SA_TTYSTOP) &&
 2087                     (p->p_pgrp->pg_jobc == 0) &&
 2088                     (action == SIG_DFL)) {
 2089                         if (ksi && (ksi->ksi_flags & KSI_INS))
 2090                                 ksiginfo_tryfree(ksi);
 2091                         return (ret);
 2092                 }
 2093                 sigqueue_delete_proc(p, SIGCONT);
 2094                 if (p->p_flag & P_CONTINUED) {
 2095                         p->p_flag &= ~P_CONTINUED;
 2096                         PROC_LOCK(p->p_pptr);
 2097                         sigqueue_take(p->p_ksi);
 2098                         PROC_UNLOCK(p->p_pptr);
 2099                 }
 2100         }
 2101 
 2102         ret = sigqueue_add(sigqueue, sig, ksi);
 2103         if (ret != 0)
 2104                 return (ret);
 2105         signotify(td);
 2106         /*
 2107          * Defer further processing for signals which are held,
 2108          * except that stopped processes must be continued by SIGCONT.
 2109          */
 2110         if (action == SIG_HOLD &&
 2111             !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG)))
 2112                 return (ret);
 2113         /*
 2114          * SIGKILL: Remove procfs STOPEVENTs.
 2115          */
 2116         if (sig == SIGKILL) {
 2117                 /* from procfs_ioctl.c: PIOCBIC */
 2118                 p->p_stops = 0;
 2119                 /* from procfs_ioctl.c: PIOCCONT */
 2120                 p->p_step = 0;
 2121                 wakeup(&p->p_step);
 2122         }
 2123         /*
 2124          * Some signals have a process-wide effect and a per-thread
 2125          * component.  Most processing occurs when the process next
 2126          * tries to cross the user boundary, however there are some
 2127          * times when processing needs to be done immediatly, such as
 2128          * waking up threads so that they can cross the user boundary.
 2129          * We try do the per-process part here.
 2130          */
 2131         if (P_SHOULDSTOP(p)) {
 2132                 if (sig == SIGKILL) {
 2133                         /*
 2134                          * If traced process is already stopped,
 2135                          * then no further action is necessary.
 2136                          */
 2137                         if (p->p_flag & P_TRACED)
 2138                                 goto out;
 2139                         /*
 2140                          * SIGKILL sets process running.
 2141                          * It will die elsewhere.
 2142                          * All threads must be restarted.
 2143                          */
 2144                         p->p_flag &= ~P_STOPPED_SIG;
 2145                         goto runfast;
 2146                 }
 2147 
 2148                 if (prop & SA_CONT) {
 2149                         /*
 2150                          * If traced process is already stopped,
 2151                          * then no further action is necessary.
 2152                          */
 2153                         if (p->p_flag & P_TRACED)
 2154                                 goto out;
 2155                         /*
 2156                          * If SIGCONT is default (or ignored), we continue the
 2157                          * process but don't leave the signal in sigqueue as
 2158                          * it has no further action.  If SIGCONT is held, we
 2159                          * continue the process and leave the signal in
 2160                          * sigqueue.  If the process catches SIGCONT, let it
 2161                          * handle the signal itself.  If it isn't waiting on
 2162                          * an event, it goes back to run state.
 2163                          * Otherwise, process goes back to sleep state.
 2164                          */
 2165                         p->p_flag &= ~P_STOPPED_SIG;
 2166                         PROC_SLOCK(p);
 2167                         if (p->p_numthreads == p->p_suspcount) {
 2168                                 PROC_SUNLOCK(p);
 2169                                 p->p_flag |= P_CONTINUED;
 2170                                 p->p_xstat = SIGCONT;
 2171                                 PROC_LOCK(p->p_pptr);
 2172                                 childproc_continued(p);
 2173                                 PROC_UNLOCK(p->p_pptr);
 2174                                 PROC_SLOCK(p);
 2175                         }
 2176                         if (action == SIG_DFL) {
 2177                                 thread_unsuspend(p);
 2178                                 PROC_SUNLOCK(p);
 2179                                 sigqueue_delete(sigqueue, sig);
 2180                                 goto out;
 2181                         }
 2182                         if (action == SIG_CATCH) {
 2183                                 /*
 2184                                  * The process wants to catch it so it needs
 2185                                  * to run at least one thread, but which one?
 2186                                  */
 2187                                 PROC_SUNLOCK(p);
 2188                                 goto runfast;
 2189                         }
 2190                         /*
 2191                          * The signal is not ignored or caught.
 2192                          */
 2193                         thread_unsuspend(p);
 2194                         PROC_SUNLOCK(p);
 2195                         goto out;
 2196                 }
 2197 
 2198                 if (prop & SA_STOP) {
 2199                         /*
 2200                          * If traced process is already stopped,
 2201                          * then no further action is necessary.
 2202                          */
 2203                         if (p->p_flag & P_TRACED)
 2204                                 goto out;
 2205                         /*
 2206                          * Already stopped, don't need to stop again
 2207                          * (If we did the shell could get confused).
 2208                          * Just make sure the signal STOP bit set.
 2209                          */
 2210                         p->p_flag |= P_STOPPED_SIG;
 2211                         sigqueue_delete(sigqueue, sig);
 2212                         goto out;
 2213                 }
 2214 
 2215                 /*
 2216                  * All other kinds of signals:
 2217                  * If a thread is sleeping interruptibly, simulate a
 2218                  * wakeup so that when it is continued it will be made
 2219                  * runnable and can look at the signal.  However, don't make
 2220                  * the PROCESS runnable, leave it stopped.
 2221                  * It may run a bit until it hits a thread_suspend_check().
 2222                  */
 2223                 wakeup_swapper = 0;
 2224                 PROC_SLOCK(p);
 2225                 thread_lock(td);
 2226                 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR))
 2227                         wakeup_swapper = sleepq_abort(td, intrval);
 2228                 thread_unlock(td);
 2229                 PROC_SUNLOCK(p);
 2230                 if (wakeup_swapper)
 2231                         kick_proc0();
 2232                 goto out;
 2233                 /*
 2234                  * Mutexes are short lived. Threads waiting on them will
 2235                  * hit thread_suspend_check() soon.
 2236                  */
 2237         } else if (p->p_state == PRS_NORMAL) {
 2238                 if (p->p_flag & P_TRACED || action == SIG_CATCH) {
 2239                         tdsigwakeup(td, sig, action, intrval);
 2240                         goto out;
 2241                 }
 2242 
 2243                 MPASS(action == SIG_DFL);
 2244 
 2245                 if (prop & SA_STOP) {
 2246                         if (p->p_flag & P_PPWAIT)
 2247                                 goto out;
 2248                         p->p_flag |= P_STOPPED_SIG;
 2249                         p->p_xstat = sig;
 2250                         PROC_SLOCK(p);
 2251                         sig_suspend_threads(td, p, 1);
 2252                         if (p->p_numthreads == p->p_suspcount) {
 2253                                 /*
 2254                                  * only thread sending signal to another
 2255                                  * process can reach here, if thread is sending
 2256                                  * signal to its process, because thread does
 2257                                  * not suspend itself here, p_numthreads
 2258                                  * should never be equal to p_suspcount.
 2259                                  */
 2260                                 thread_stopped(p);
 2261                                 PROC_SUNLOCK(p);
 2262                                 sigqueue_delete_proc(p, p->p_xstat);
 2263                         } else
 2264                                 PROC_SUNLOCK(p);
 2265                         goto out;
 2266                 }
 2267         } else {
 2268                 /* Not in "NORMAL" state. discard the signal. */
 2269                 sigqueue_delete(sigqueue, sig);
 2270                 goto out;
 2271         }
 2272 
 2273         /*
 2274          * The process is not stopped so we need to apply the signal to all the
 2275          * running threads.
 2276          */
 2277 runfast:
 2278         tdsigwakeup(td, sig, action, intrval);
 2279         PROC_SLOCK(p);
 2280         thread_unsuspend(p);
 2281         PROC_SUNLOCK(p);
 2282 out:
 2283         /* If we jump here, proc slock should not be owned. */
 2284         PROC_SLOCK_ASSERT(p, MA_NOTOWNED);
 2285         return (ret);
 2286 }
 2287 
 2288 /*
 2289  * The force of a signal has been directed against a single
 2290  * thread.  We need to see what we can do about knocking it
 2291  * out of any sleep it may be in etc.
 2292  */
 2293 static void
 2294 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval)
 2295 {
 2296         struct proc *p = td->td_proc;
 2297         register int prop;
 2298         int wakeup_swapper;
 2299 
 2300         wakeup_swapper = 0;
 2301         PROC_LOCK_ASSERT(p, MA_OWNED);
 2302         prop = sigprop(sig);
 2303 
 2304         PROC_SLOCK(p);
 2305         thread_lock(td);
 2306         /*
 2307          * Bring the priority of a thread up if we want it to get
 2308          * killed in this lifetime.
 2309          */
 2310         if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER)
 2311                 sched_prio(td, PUSER);
 2312         if (TD_ON_SLEEPQ(td)) {
 2313                 /*
 2314                  * If thread is sleeping uninterruptibly
 2315                  * we can't interrupt the sleep... the signal will
 2316                  * be noticed when the process returns through
 2317                  * trap() or syscall().
 2318                  */
 2319                 if ((td->td_flags & TDF_SINTR) == 0)
 2320                         goto out;
 2321                 /*
 2322                  * If SIGCONT is default (or ignored) and process is
 2323                  * asleep, we are finished; the process should not
 2324                  * be awakened.
 2325                  */
 2326                 if ((prop & SA_CONT) && action == SIG_DFL) {
 2327                         thread_unlock(td);
 2328                         PROC_SUNLOCK(p);
 2329                         sigqueue_delete(&p->p_sigqueue, sig);
 2330                         /*
 2331                          * It may be on either list in this state.
 2332                          * Remove from both for now.
 2333                          */
 2334                         sigqueue_delete(&td->td_sigqueue, sig);
 2335                         return;
 2336                 }
 2337 
 2338                 /*
 2339                  * Give low priority threads a better chance to run.
 2340                  */
 2341                 if (td->td_priority > PUSER)
 2342                         sched_prio(td, PUSER);
 2343 
 2344                 wakeup_swapper = sleepq_abort(td, intrval);
 2345         } else {
 2346                 /*
 2347                  * Other states do nothing with the signal immediately,
 2348                  * other than kicking ourselves if we are running.
 2349                  * It will either never be noticed, or noticed very soon.
 2350                  */
 2351 #ifdef SMP
 2352                 if (TD_IS_RUNNING(td) && td != curthread)
 2353                         forward_signal(td);
 2354 #endif
 2355         }
 2356 out:
 2357         PROC_SUNLOCK(p);
 2358         thread_unlock(td);
 2359         if (wakeup_swapper)
 2360                 kick_proc0();
 2361 }
 2362 
 2363 static void
 2364 sig_suspend_threads(struct thread *td, struct proc *p, int sending)
 2365 {
 2366         struct thread *td2;
 2367         int wakeup_swapper;
 2368 
 2369         PROC_LOCK_ASSERT(p, MA_OWNED);
 2370         PROC_SLOCK_ASSERT(p, MA_OWNED);
 2371 
 2372         wakeup_swapper = 0;
 2373         FOREACH_THREAD_IN_PROC(p, td2) {
 2374                 thread_lock(td2);
 2375                 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK;
 2376                 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) &&
 2377                     (td2->td_flags & TDF_SINTR)) {
 2378                         if (td2->td_flags & TDF_SBDRY) {
 2379                                 if (TD_IS_SUSPENDED(td2))
 2380                                         wakeup_swapper |=
 2381                                             thread_unsuspend_one(td2);
 2382                                 if (TD_ON_SLEEPQ(td2))
 2383                                         wakeup_swapper |=
 2384                                             sleepq_abort(td2, ERESTART);
 2385                         } else if (!TD_IS_SUSPENDED(td2)) {
 2386                                 thread_suspend_one(td2);
 2387                         }
 2388                 } else if (!TD_IS_SUSPENDED(td2)) {
 2389                         if (sending || td != td2)
 2390                                 td2->td_flags |= TDF_ASTPENDING;
 2391 #ifdef SMP
 2392                         if (TD_IS_RUNNING(td2) && td2 != td)
 2393                                 forward_signal(td2);
 2394 #endif
 2395                 }
 2396                 thread_unlock(td2);
 2397         }
 2398         if (wakeup_swapper)
 2399                 kick_proc0();
 2400 }
 2401 
 2402 int
 2403 ptracestop(struct thread *td, int sig)
 2404 {
 2405         struct proc *p = td->td_proc;
 2406 
 2407         PROC_LOCK_ASSERT(p, MA_OWNED);
 2408         WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
 2409             &p->p_mtx.lock_object, "Stopping for traced signal");
 2410 
 2411         td->td_dbgflags |= TDB_XSIG;
 2412         td->td_xsig = sig;
 2413         PROC_SLOCK(p);
 2414         while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) {
 2415                 if (p->p_flag & P_SINGLE_EXIT) {
 2416                         td->td_dbgflags &= ~TDB_XSIG;
 2417                         PROC_SUNLOCK(p);
 2418                         return (sig);
 2419                 }
 2420                 /*
 2421                  * Just make wait() to work, the last stopped thread
 2422                  * will win.
 2423                  */
 2424                 p->p_xstat = sig;
 2425                 p->p_xthread = td;
 2426                 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE);
 2427                 sig_suspend_threads(td, p, 0);
 2428 stopme:
 2429                 thread_suspend_switch(td);
 2430                 if (!(p->p_flag & P_TRACED)) {
 2431                         break;
 2432                 }
 2433                 if (td->td_dbgflags & TDB_SUSPEND) {
 2434                         if (p->p_flag & P_SINGLE_EXIT)
 2435                                 break;
 2436                         goto stopme;
 2437                 }
 2438         }
 2439         PROC_SUNLOCK(p);
 2440         return (td->td_xsig);
 2441 }
 2442 
 2443 static void
 2444 reschedule_signals(struct proc *p, sigset_t block, int flags)
 2445 {
 2446         struct sigacts *ps;
 2447         struct thread *td;
 2448         int i;
 2449 
 2450         PROC_LOCK_ASSERT(p, MA_OWNED);
 2451 
 2452         ps = p->p_sigacts;
 2453         for (i = 1; !SIGISEMPTY(block); i++) {
 2454                 if (!SIGISMEMBER(block, i))
 2455                         continue;
 2456                 SIGDELSET(block, i);
 2457                 if (!SIGISMEMBER(p->p_siglist, i))
 2458                         continue;
 2459 
 2460                 td = sigtd(p, i, 0);
 2461                 signotify(td);
 2462                 if (!(flags & SIGPROCMASK_PS_LOCKED))
 2463                         mtx_lock(&ps->ps_mtx);
 2464                 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, i))
 2465                         tdsigwakeup(td, i, SIG_CATCH,
 2466                             (SIGISMEMBER(ps->ps_sigintr, i) ? EINTR :
 2467                              ERESTART));
 2468                 if (!(flags & SIGPROCMASK_PS_LOCKED))
 2469                         mtx_unlock(&ps->ps_mtx);
 2470         }
 2471 }
 2472 
 2473 void
 2474 tdsigcleanup(struct thread *td)
 2475 {
 2476         struct proc *p;
 2477         sigset_t unblocked;
 2478 
 2479         p = td->td_proc;
 2480         PROC_LOCK_ASSERT(p, MA_OWNED);
 2481 
 2482         sigqueue_flush(&td->td_sigqueue);
 2483         if (p->p_numthreads == 1)
 2484                 return;
 2485 
 2486         /*
 2487          * Since we cannot handle signals, notify signal post code
 2488          * about this by filling the sigmask.
 2489          *
 2490          * Also, if needed, wake up thread(s) that do not block the
 2491          * same signals as the exiting thread, since the thread might
 2492          * have been selected for delivery and woken up.
 2493          */
 2494         SIGFILLSET(unblocked);
 2495         SIGSETNAND(unblocked, td->td_sigmask);
 2496         SIGFILLSET(td->td_sigmask);
 2497         reschedule_signals(p, unblocked, 0);
 2498 
 2499 }
 2500 
 2501 /*
 2502  * If the current process has received a signal (should be caught or cause
 2503  * termination, should interrupt current syscall), return the signal number.
 2504  * Stop signals with default action are processed immediately, then cleared;
 2505  * they aren't returned.  This is checked after each entry to the system for
 2506  * a syscall or trap (though this can usually be done without calling issignal
 2507  * by checking the pending signal masks in cursig.) The normal call
 2508  * sequence is
 2509  *
 2510  *      while (sig = cursig(curthread))
 2511  *              postsig(sig);
 2512  */
 2513 static int
 2514 issignal(struct thread *td, int stop_allowed)
 2515 {
 2516         struct proc *p;
 2517         struct sigacts *ps;
 2518         struct sigqueue *queue;
 2519         sigset_t sigpending;
 2520         int sig, prop, newsig;
 2521 
 2522         p = td->td_proc;
 2523         ps = p->p_sigacts;
 2524         mtx_assert(&ps->ps_mtx, MA_OWNED);
 2525         PROC_LOCK_ASSERT(p, MA_OWNED);
 2526         for (;;) {
 2527                 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
 2528 
 2529                 sigpending = td->td_sigqueue.sq_signals;
 2530                 SIGSETOR(sigpending, p->p_sigqueue.sq_signals);
 2531                 SIGSETNAND(sigpending, td->td_sigmask);
 2532 
 2533                 if (p->p_flag & P_PPWAIT)
 2534                         SIG_STOPSIGMASK(sigpending);
 2535                 if (SIGISEMPTY(sigpending))     /* no signal to send */
 2536                         return (0);
 2537                 sig = sig_ffs(&sigpending);
 2538 
 2539                 if (p->p_stops & S_SIG) {
 2540                         mtx_unlock(&ps->ps_mtx);
 2541                         stopevent(p, S_SIG, sig);
 2542                         mtx_lock(&ps->ps_mtx);
 2543                 }
 2544 
 2545                 /*
 2546                  * We should see pending but ignored signals
 2547                  * only if P_TRACED was on when they were posted.
 2548                  */
 2549                 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) {
 2550                         sigqueue_delete(&td->td_sigqueue, sig);
 2551                         sigqueue_delete(&p->p_sigqueue, sig);
 2552                         continue;
 2553                 }
 2554                 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) {
 2555                         /*
 2556                          * If traced, always stop.
 2557                          * Remove old signal from queue before the stop.
 2558                          * XXX shrug off debugger, it causes siginfo to
 2559                          * be thrown away.
 2560                          */
 2561                         queue = &td->td_sigqueue;
 2562                         td->td_dbgksi.ksi_signo = 0;
 2563                         if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) {
 2564                                 queue = &p->p_sigqueue;
 2565                                 sigqueue_get(queue, sig, &td->td_dbgksi);
 2566                         }
 2567 
 2568                         mtx_unlock(&ps->ps_mtx);
 2569                         newsig = ptracestop(td, sig);
 2570                         mtx_lock(&ps->ps_mtx);
 2571 
 2572                         if (sig != newsig) {
 2573 
 2574                                 /*
 2575                                  * If parent wants us to take the signal,
 2576                                  * then it will leave it in p->p_xstat;
 2577                                  * otherwise we just look for signals again.
 2578                                 */
 2579                                 if (newsig == 0)
 2580                                         continue;
 2581                                 sig = newsig;
 2582 
 2583                                 /*
 2584                                  * Put the new signal into td_sigqueue. If the
 2585                                  * signal is being masked, look for other signals.
 2586                                  */
 2587                                 sigqueue_add(queue, sig, NULL);
 2588                                 if (SIGISMEMBER(td->td_sigmask, sig))
 2589                                         continue;
 2590                                 signotify(td);
 2591                         } else {
 2592                                 if (td->td_dbgksi.ksi_signo != 0) {
 2593                                         td->td_dbgksi.ksi_flags |= KSI_HEAD;
 2594                                         if (sigqueue_add(&td->td_sigqueue, sig,
 2595                                             &td->td_dbgksi) != 0)
 2596                                                 td->td_dbgksi.ksi_signo = 0;
 2597                                 }
 2598                                 if (td->td_dbgksi.ksi_signo == 0)
 2599                                         sigqueue_add(&td->td_sigqueue, sig,
 2600                                             NULL);
 2601                         }
 2602 
 2603                         /*
 2604                          * If the traced bit got turned off, go back up
 2605                          * to the top to rescan signals.  This ensures
 2606                          * that p_sig* and p_sigact are consistent.
 2607                          */
 2608                         if ((p->p_flag & P_TRACED) == 0)
 2609                                 continue;
 2610                 }
 2611 
 2612                 prop = sigprop(sig);
 2613 
 2614                 /*
 2615                  * Decide whether the signal should be returned.
 2616                  * Return the signal's number, or fall through
 2617                  * to clear it from the pending mask.
 2618                  */
 2619                 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
 2620 
 2621                 case (intptr_t)SIG_DFL:
 2622                         /*
 2623                          * Don't take default actions on system processes.
 2624                          */
 2625                         if (p->p_pid <= 1) {
 2626 #ifdef DIAGNOSTIC
 2627                                 /*
 2628                                  * Are you sure you want to ignore SIGSEGV
 2629                                  * in init? XXX
 2630                                  */
 2631                                 printf("Process (pid %lu) got signal %d\n",
 2632                                         (u_long)p->p_pid, sig);
 2633 #endif
 2634                                 break;          /* == ignore */
 2635                         }
 2636                         /*
 2637                          * If there is a pending stop signal to process
 2638                          * with default action, stop here,
 2639                          * then clear the signal.  However,
 2640                          * if process is member of an orphaned
 2641                          * process group, ignore tty stop signals.
 2642                          */
 2643                         if (prop & SA_STOP) {
 2644                                 if (p->p_flag & P_TRACED ||
 2645                                     (p->p_pgrp->pg_jobc == 0 &&
 2646                                      prop & SA_TTYSTOP))
 2647                                         break;  /* == ignore */
 2648 
 2649                                 /* Ignore, but do not drop the stop signal. */
 2650                                 if (stop_allowed != SIG_STOP_ALLOWED)
 2651                                         return (sig);
 2652                                 mtx_unlock(&ps->ps_mtx);
 2653                                 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
 2654                                     &p->p_mtx.lock_object, "Catching SIGSTOP");
 2655                                 p->p_flag |= P_STOPPED_SIG;
 2656                                 p->p_xstat = sig;
 2657                                 PROC_SLOCK(p);
 2658                                 sig_suspend_threads(td, p, 0);
 2659                                 thread_suspend_switch(td);
 2660                                 PROC_SUNLOCK(p);
 2661                                 mtx_lock(&ps->ps_mtx);
 2662                                 break;
 2663                         } else if (prop & SA_IGNORE) {
 2664                                 /*
 2665                                  * Except for SIGCONT, shouldn't get here.
 2666                                  * Default action is to ignore; drop it.
 2667                                  */
 2668                                 break;          /* == ignore */
 2669                         } else
 2670                                 return (sig);
 2671                         /*NOTREACHED*/
 2672 
 2673                 case (intptr_t)SIG_IGN:
 2674                         /*
 2675                          * Masking above should prevent us ever trying
 2676                          * to take action on an ignored signal other
 2677                          * than SIGCONT, unless process is traced.
 2678                          */
 2679                         if ((prop & SA_CONT) == 0 &&
 2680                             (p->p_flag & P_TRACED) == 0)
 2681                                 printf("issignal\n");
 2682                         break;          /* == ignore */
 2683 
 2684                 default:
 2685                         /*
 2686                          * This signal has an action, let
 2687                          * postsig() process it.
 2688                          */
 2689                         return (sig);
 2690                 }
 2691                 sigqueue_delete(&td->td_sigqueue, sig);         /* take the signal! */
 2692                 sigqueue_delete(&p->p_sigqueue, sig);
 2693         }
 2694         /* NOTREACHED */
 2695 }
 2696 
 2697 void
 2698 thread_stopped(struct proc *p)
 2699 {
 2700         int n;
 2701 
 2702         PROC_LOCK_ASSERT(p, MA_OWNED);
 2703         PROC_SLOCK_ASSERT(p, MA_OWNED);
 2704         n = p->p_suspcount;
 2705         if (p == curproc)
 2706                 n++;
 2707         if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) {
 2708                 PROC_SUNLOCK(p);
 2709                 p->p_flag &= ~P_WAITED;
 2710                 PROC_LOCK(p->p_pptr);
 2711                 childproc_stopped(p, (p->p_flag & P_TRACED) ?
 2712                         CLD_TRAPPED : CLD_STOPPED);
 2713                 PROC_UNLOCK(p->p_pptr);
 2714                 PROC_SLOCK(p);
 2715         }
 2716 }
 2717  
 2718 /*
 2719  * Take the action for the specified signal
 2720  * from the current set of pending signals.
 2721  */
 2722 int
 2723 postsig(sig)
 2724         register int sig;
 2725 {
 2726         struct thread *td = curthread;
 2727         register struct proc *p = td->td_proc;
 2728         struct sigacts *ps;
 2729         sig_t action;
 2730         ksiginfo_t ksi;
 2731         sigset_t returnmask, mask;
 2732 
 2733         KASSERT(sig != 0, ("postsig"));
 2734 
 2735         PROC_LOCK_ASSERT(p, MA_OWNED);
 2736         ps = p->p_sigacts;
 2737         mtx_assert(&ps->ps_mtx, MA_OWNED);
 2738         ksiginfo_init(&ksi);
 2739         if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 &&
 2740             sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0)
 2741                 return (0);
 2742         ksi.ksi_signo = sig;
 2743         if (ksi.ksi_code == SI_TIMER)
 2744                 itimer_accept(p, ksi.ksi_timerid, &ksi);
 2745         action = ps->ps_sigact[_SIG_IDX(sig)];
 2746 #ifdef KTRACE
 2747         if (KTRPOINT(td, KTR_PSIG))
 2748                 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ?
 2749                     &td->td_oldsigmask : &td->td_sigmask, 0);
 2750 #endif
 2751         if (p->p_stops & S_SIG) {
 2752                 mtx_unlock(&ps->ps_mtx);
 2753                 stopevent(p, S_SIG, sig);
 2754                 mtx_lock(&ps->ps_mtx);
 2755         }
 2756 
 2757         if (action == SIG_DFL) {
 2758                 /*
 2759                  * Default action, where the default is to kill
 2760                  * the process.  (Other cases were ignored above.)
 2761                  */
 2762                 mtx_unlock(&ps->ps_mtx);
 2763                 sigexit(td, sig);
 2764                 /* NOTREACHED */
 2765         } else {
 2766                 /*
 2767                  * If we get here, the signal must be caught.
 2768                  */
 2769                 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig),
 2770                     ("postsig action"));
 2771                 /*
 2772                  * Set the new mask value and also defer further
 2773                  * occurrences of this signal.
 2774                  *
 2775                  * Special case: user has done a sigsuspend.  Here the
 2776                  * current mask is not of interest, but rather the
 2777                  * mask from before the sigsuspend is what we want
 2778                  * restored after the signal processing is completed.
 2779                  */
 2780                 if (td->td_pflags & TDP_OLDMASK) {
 2781                         returnmask = td->td_oldsigmask;
 2782                         td->td_pflags &= ~TDP_OLDMASK;
 2783                 } else
 2784                         returnmask = td->td_sigmask;
 2785 
 2786                 mask = ps->ps_catchmask[_SIG_IDX(sig)];
 2787                 if (!SIGISMEMBER(ps->ps_signodefer, sig))
 2788                         SIGADDSET(mask, sig);
 2789                 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL,
 2790                     SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED);
 2791 
 2792                 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
 2793                         /*
 2794                          * See kern_sigaction() for origin of this code.
 2795                          */
 2796                         SIGDELSET(ps->ps_sigcatch, sig);
 2797                         if (sig != SIGCONT &&
 2798                             sigprop(sig) & SA_IGNORE)
 2799                                 SIGADDSET(ps->ps_sigignore, sig);
 2800                         ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
 2801                 }
 2802                 td->td_ru.ru_nsignals++;
 2803                 if (p->p_sig == sig) {
 2804                         p->p_code = 0;
 2805                         p->p_sig = 0;
 2806                 }
 2807                 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask);
 2808         }
 2809         return (1);
 2810 }
 2811 
 2812 /*
 2813  * Kill the current process for stated reason.
 2814  */
 2815 void
 2816 killproc(p, why)
 2817         struct proc *p;
 2818         char *why;
 2819 {
 2820 
 2821         PROC_LOCK_ASSERT(p, MA_OWNED);
 2822         CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)",
 2823                 p, p->p_pid, p->p_comm);
 2824         log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm,
 2825                 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
 2826         p->p_flag |= P_WKILLED;
 2827         psignal(p, SIGKILL);
 2828 }
 2829 
 2830 /*
 2831  * Force the current process to exit with the specified signal, dumping core
 2832  * if appropriate.  We bypass the normal tests for masked and caught signals,
 2833  * allowing unrecoverable failures to terminate the process without changing
 2834  * signal state.  Mark the accounting record with the signal termination.
 2835  * If dumping core, save the signal number for the debugger.  Calls exit and
 2836  * does not return.
 2837  */
 2838 void
 2839 sigexit(td, sig)
 2840         struct thread *td;
 2841         int sig;
 2842 {
 2843         struct proc *p = td->td_proc;
 2844 
 2845         PROC_LOCK_ASSERT(p, MA_OWNED);
 2846         p->p_acflag |= AXSIG;
 2847         /*
 2848          * We must be single-threading to generate a core dump.  This
 2849          * ensures that the registers in the core file are up-to-date.
 2850          * Also, the ELF dump handler assumes that the thread list doesn't
 2851          * change out from under it.
 2852          *
 2853          * XXX If another thread attempts to single-thread before us
 2854          *     (e.g. via fork()), we won't get a dump at all.
 2855          */
 2856         if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) {
 2857                 p->p_sig = sig;
 2858                 /*
 2859                  * Log signals which would cause core dumps
 2860                  * (Log as LOG_INFO to appease those who don't want
 2861                  * these messages.)
 2862                  * XXX : Todo, as well as euid, write out ruid too
 2863                  * Note that coredump() drops proc lock.
 2864                  */
 2865                 if (coredump(td) == 0)
 2866                         sig |= WCOREFLAG;
 2867                 if (kern_logsigexit)
 2868                         log(LOG_INFO,
 2869                             "pid %d (%s), uid %d: exited on signal %d%s\n",
 2870                             p->p_pid, p->p_comm,
 2871                             td->td_ucred ? td->td_ucred->cr_uid : -1,
 2872                             sig &~ WCOREFLAG,
 2873                             sig & WCOREFLAG ? " (core dumped)" : "");
 2874         } else
 2875                 PROC_UNLOCK(p);
 2876         exit1(td, W_EXITCODE(0, sig));
 2877         /* NOTREACHED */
 2878 }
 2879 
 2880 /*
 2881  * Send queued SIGCHLD to parent when child process's state
 2882  * is changed.
 2883  */
 2884 static void
 2885 sigparent(struct proc *p, int reason, int status)
 2886 {
 2887         PROC_LOCK_ASSERT(p, MA_OWNED);
 2888         PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
 2889 
 2890         if (p->p_ksi != NULL) {
 2891                 p->p_ksi->ksi_signo  = SIGCHLD;
 2892                 p->p_ksi->ksi_code   = reason;
 2893                 p->p_ksi->ksi_status = status;
 2894                 p->p_ksi->ksi_pid    = p->p_pid;
 2895                 p->p_ksi->ksi_uid    = p->p_ucred->cr_ruid;
 2896                 if (KSI_ONQ(p->p_ksi))
 2897                         return;
 2898         }
 2899         tdsignal(p->p_pptr, NULL, SIGCHLD, p->p_ksi);
 2900 }
 2901 
 2902 static void
 2903 childproc_jobstate(struct proc *p, int reason, int status)
 2904 {
 2905         struct sigacts *ps;
 2906 
 2907         PROC_LOCK_ASSERT(p, MA_OWNED);
 2908         PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
 2909 
 2910         /*
 2911          * Wake up parent sleeping in kern_wait(), also send
 2912          * SIGCHLD to parent, but SIGCHLD does not guarantee
 2913          * that parent will awake, because parent may masked
 2914          * the signal.
 2915          */
 2916         p->p_pptr->p_flag |= P_STATCHILD;
 2917         wakeup(p->p_pptr);
 2918 
 2919         ps = p->p_pptr->p_sigacts;
 2920         mtx_lock(&ps->ps_mtx);
 2921         if ((ps->ps_flag & PS_NOCLDSTOP) == 0) {
 2922                 mtx_unlock(&ps->ps_mtx);
 2923                 sigparent(p, reason, status);
 2924         } else
 2925                 mtx_unlock(&ps->ps_mtx);
 2926 }
 2927 
 2928 void
 2929 childproc_stopped(struct proc *p, int reason)
 2930 {
 2931         childproc_jobstate(p, reason, p->p_xstat);
 2932 }
 2933 
 2934 void
 2935 childproc_continued(struct proc *p)
 2936 {
 2937         childproc_jobstate(p, CLD_CONTINUED, SIGCONT);
 2938 }
 2939 
 2940 void
 2941 childproc_exited(struct proc *p)
 2942 {
 2943         int reason;
 2944         int status = p->p_xstat; /* convert to int */
 2945 
 2946         reason = CLD_EXITED;
 2947         if (WCOREDUMP(status))
 2948                 reason = CLD_DUMPED;
 2949         else if (WIFSIGNALED(status))
 2950                 reason = CLD_KILLED;
 2951         /*
 2952          * XXX avoid calling wakeup(p->p_pptr), the work is
 2953          * done in exit1().
 2954          */
 2955         sigparent(p, reason, status);
 2956 }
 2957 
 2958 static char corefilename[MAXPATHLEN] = {"%N.core"};
 2959 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
 2960               sizeof(corefilename), "process corefile name format string");
 2961 
 2962 /*
 2963  * expand_name(name, uid, pid)
 2964  * Expand the name described in corefilename, using name, uid, and pid.
 2965  * corefilename is a printf-like string, with three format specifiers:
 2966  *      %N      name of process ("name")
 2967  *      %P      process id (pid)
 2968  *      %U      user id (uid)
 2969  * For example, "%N.core" is the default; they can be disabled completely
 2970  * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
 2971  * This is controlled by the sysctl variable kern.corefile (see above).
 2972  */
 2973 static char *
 2974 expand_name(name, uid, pid)
 2975         const char *name;
 2976         uid_t uid;
 2977         pid_t pid;
 2978 {
 2979         struct sbuf sb;
 2980         const char *format;
 2981         char *temp;
 2982         size_t i;
 2983 
 2984         format = corefilename;
 2985         temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO);
 2986         if (temp == NULL)
 2987                 return (NULL);
 2988         (void)sbuf_new(&sb, temp, MAXPATHLEN, SBUF_FIXEDLEN);
 2989         for (i = 0; format[i]; i++) {
 2990                 switch (format[i]) {
 2991                 case '%':       /* Format character */
 2992                         i++;
 2993                         switch (format[i]) {
 2994                         case '%':
 2995                                 sbuf_putc(&sb, '%');
 2996                                 break;
 2997                         case 'N':       /* process name */
 2998                                 sbuf_printf(&sb, "%s", name);
 2999                                 break;
 3000                         case 'P':       /* process id */
 3001                                 sbuf_printf(&sb, "%u", pid);
 3002                                 break;
 3003                         case 'U':       /* user id */
 3004                                 sbuf_printf(&sb, "%u", uid);
 3005                                 break;
 3006                         default:
 3007                                 log(LOG_ERR,
 3008                                     "Unknown format character %c in "
 3009                                     "corename `%s'\n", format[i], format);
 3010                         }
 3011                         break;
 3012                 default:
 3013                         sbuf_putc(&sb, format[i]);
 3014                 }
 3015         }
 3016         if (sbuf_overflowed(&sb)) {
 3017                 sbuf_delete(&sb);
 3018                 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too "
 3019                     "long\n", (long)pid, name, (u_long)uid);
 3020                 free(temp, M_TEMP);
 3021                 return (NULL);
 3022         }
 3023         sbuf_finish(&sb);
 3024         sbuf_delete(&sb);
 3025         return (temp);
 3026 }
 3027 
 3028 /*
 3029  * Dump a process' core.  The main routine does some
 3030  * policy checking, and creates the name of the coredump;
 3031  * then it passes on a vnode and a size limit to the process-specific
 3032  * coredump routine if there is one; if there _is not_ one, it returns
 3033  * ENOSYS; otherwise it returns the error from the process-specific routine.
 3034  */
 3035 
 3036 static int
 3037 coredump(struct thread *td)
 3038 {
 3039         struct proc *p = td->td_proc;
 3040         register struct vnode *vp;
 3041         register struct ucred *cred = td->td_ucred;
 3042         struct flock lf;
 3043         struct nameidata nd;
 3044         struct vattr vattr;
 3045         int error, error1, flags, locked;
 3046         struct mount *mp;
 3047         char *name;                     /* name of corefile */
 3048         off_t limit;
 3049         int vfslocked;
 3050 
 3051         PROC_LOCK_ASSERT(p, MA_OWNED);
 3052         MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td);
 3053         _STOPEVENT(p, S_CORE, 0);
 3054 
 3055         name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid);
 3056         if (name == NULL) {
 3057                 PROC_UNLOCK(p);
 3058 #ifdef AUDIT
 3059                 audit_proc_coredump(td, NULL, EINVAL);
 3060 #endif
 3061                 return (EINVAL);
 3062         }
 3063         if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) {
 3064                 PROC_UNLOCK(p);
 3065 #ifdef AUDIT
 3066                 audit_proc_coredump(td, name, EFAULT);
 3067 #endif
 3068                 free(name, M_TEMP);
 3069                 return (EFAULT);
 3070         }
 3071         
 3072         /*
 3073          * Note that the bulk of limit checking is done after
 3074          * the corefile is created.  The exception is if the limit
 3075          * for corefiles is 0, in which case we don't bother
 3076          * creating the corefile at all.  This layout means that
 3077          * a corefile is truncated instead of not being created,
 3078          * if it is larger than the limit.
 3079          */
 3080         limit = (off_t)lim_cur(p, RLIMIT_CORE);
 3081         PROC_UNLOCK(p);
 3082         if (limit == 0) {
 3083 #ifdef AUDIT
 3084                 audit_proc_coredump(td, name, EFBIG);
 3085 #endif
 3086                 free(name, M_TEMP);
 3087                 return (EFBIG);
 3088         }
 3089 
 3090 restart:
 3091         NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, name, td);
 3092         flags = O_CREAT | FWRITE | O_NOFOLLOW;
 3093         error = vn_open_cred(&nd, &flags, S_IRUSR | S_IWUSR, VN_OPEN_NOAUDIT,
 3094             cred, NULL);
 3095         if (error) {
 3096 #ifdef AUDIT
 3097                 audit_proc_coredump(td, name, error);
 3098 #endif
 3099                 free(name, M_TEMP);
 3100                 return (error);
 3101         }
 3102         vfslocked = NDHASGIANT(&nd);
 3103         NDFREE(&nd, NDF_ONLY_PNBUF);
 3104         vp = nd.ni_vp;
 3105 
 3106         /* Don't dump to non-regular files or files with links. */
 3107         if (vp->v_type != VREG ||
 3108             VOP_GETATTR(vp, &vattr, cred) || vattr.va_nlink != 1) {
 3109                 VOP_UNLOCK(vp, 0);
 3110                 error = EFAULT;
 3111                 goto close;
 3112         }
 3113 
 3114         VOP_UNLOCK(vp, 0);
 3115         lf.l_whence = SEEK_SET;
 3116         lf.l_start = 0;
 3117         lf.l_len = 0;
 3118         lf.l_type = F_WRLCK;
 3119         locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0);
 3120 
 3121         if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
 3122                 lf.l_type = F_UNLCK;
 3123                 if (locked)
 3124                         VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
 3125                 if ((error = vn_close(vp, FWRITE, cred, td)) != 0)
 3126                         goto out;
 3127                 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
 3128                         goto out;
 3129                 VFS_UNLOCK_GIANT(vfslocked);
 3130                 goto restart;
 3131         }
 3132 
 3133         VATTR_NULL(&vattr);
 3134         vattr.va_size = 0;
 3135         if (set_core_nodump_flag)
 3136                 vattr.va_flags = UF_NODUMP;
 3137         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 3138         VOP_SETATTR(vp, &vattr, cred);
 3139         VOP_UNLOCK(vp, 0);
 3140         vn_finished_write(mp);
 3141         PROC_LOCK(p);
 3142         p->p_acflag |= ACORE;
 3143         PROC_UNLOCK(p);
 3144 
 3145         error = p->p_sysent->sv_coredump ?
 3146           p->p_sysent->sv_coredump(td, vp, limit) :
 3147           ENOSYS;
 3148 
 3149         if (locked) {
 3150                 lf.l_type = F_UNLCK;
 3151                 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
 3152         }
 3153 close:
 3154         error1 = vn_close(vp, FWRITE, cred, td);
 3155         if (error == 0)
 3156                 error = error1;
 3157 out:
 3158 #ifdef AUDIT
 3159         audit_proc_coredump(td, name, error);
 3160 #endif
 3161         free(name, M_TEMP);
 3162         VFS_UNLOCK_GIANT(vfslocked);
 3163         return (error);
 3164 }
 3165 
 3166 /*
 3167  * Nonexistent system call-- signal process (may want to handle it).  Flag
 3168  * error in case process won't see signal immediately (blocked or ignored).
 3169  */
 3170 #ifndef _SYS_SYSPROTO_H_
 3171 struct nosys_args {
 3172         int     dummy;
 3173 };
 3174 #endif
 3175 /* ARGSUSED */
 3176 int
 3177 nosys(td, args)
 3178         struct thread *td;
 3179         struct nosys_args *args;
 3180 {
 3181         struct proc *p = td->td_proc;
 3182 
 3183         PROC_LOCK(p);
 3184         psignal(p, SIGSYS);
 3185         PROC_UNLOCK(p);
 3186         return (ENOSYS);
 3187 }
 3188 
 3189 /*
 3190  * Send a SIGIO or SIGURG signal to a process or process group using stored
 3191  * credentials rather than those of the current process.
 3192  */
 3193 void
 3194 pgsigio(sigiop, sig, checkctty)
 3195         struct sigio **sigiop;
 3196         int sig, checkctty;
 3197 {
 3198         ksiginfo_t ksi;
 3199         struct sigio *sigio;
 3200 
 3201         ksiginfo_init(&ksi);
 3202         ksi.ksi_signo = sig;
 3203         ksi.ksi_code = SI_KERNEL;
 3204 
 3205         SIGIO_LOCK();
 3206         sigio = *sigiop;
 3207         if (sigio == NULL) {
 3208                 SIGIO_UNLOCK();
 3209                 return;
 3210         }
 3211         if (sigio->sio_pgid > 0) {
 3212                 PROC_LOCK(sigio->sio_proc);
 3213                 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred))
 3214                         psignal(sigio->sio_proc, sig);
 3215                 PROC_UNLOCK(sigio->sio_proc);
 3216         } else if (sigio->sio_pgid < 0) {
 3217                 struct proc *p;
 3218 
 3219                 PGRP_LOCK(sigio->sio_pgrp);
 3220                 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
 3221                         PROC_LOCK(p);
 3222                         if (CANSIGIO(sigio->sio_ucred, p->p_ucred) &&
 3223                             (checkctty == 0 || (p->p_flag & P_CONTROLT)))
 3224                                 psignal(p, sig);
 3225                         PROC_UNLOCK(p);
 3226                 }
 3227                 PGRP_UNLOCK(sigio->sio_pgrp);
 3228         }
 3229         SIGIO_UNLOCK();
 3230 }
 3231 
 3232 static int
 3233 filt_sigattach(struct knote *kn)
 3234 {
 3235         struct proc *p = curproc;
 3236 
 3237         kn->kn_ptr.p_proc = p;
 3238         kn->kn_flags |= EV_CLEAR;               /* automatically set */
 3239 
 3240         knlist_add(&p->p_klist, kn, 0);
 3241 
 3242         return (0);
 3243 }
 3244 
 3245 static void
 3246 filt_sigdetach(struct knote *kn)
 3247 {
 3248         struct proc *p = kn->kn_ptr.p_proc;
 3249 
 3250         knlist_remove(&p->p_klist, kn, 0);
 3251 }
 3252 
 3253 /*
 3254  * signal knotes are shared with proc knotes, so we apply a mask to 
 3255  * the hint in order to differentiate them from process hints.  This
 3256  * could be avoided by using a signal-specific knote list, but probably
 3257  * isn't worth the trouble.
 3258  */
 3259 static int
 3260 filt_signal(struct knote *kn, long hint)
 3261 {
 3262 
 3263         if (hint & NOTE_SIGNAL) {
 3264                 hint &= ~NOTE_SIGNAL;
 3265 
 3266                 if (kn->kn_id == hint)
 3267                         kn->kn_data++;
 3268         }
 3269         return (kn->kn_data != 0);
 3270 }
 3271 
 3272 struct sigacts *
 3273 sigacts_alloc(void)
 3274 {
 3275         struct sigacts *ps;
 3276 
 3277         ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO);
 3278         ps->ps_refcnt = 1;
 3279         mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF);
 3280         return (ps);
 3281 }
 3282 
 3283 void
 3284 sigacts_free(struct sigacts *ps)
 3285 {
 3286 
 3287         mtx_lock(&ps->ps_mtx);
 3288         ps->ps_refcnt--;
 3289         if (ps->ps_refcnt == 0) {
 3290                 mtx_destroy(&ps->ps_mtx);
 3291                 free(ps, M_SUBPROC);
 3292         } else
 3293                 mtx_unlock(&ps->ps_mtx);
 3294 }
 3295 
 3296 struct sigacts *
 3297 sigacts_hold(struct sigacts *ps)
 3298 {
 3299         mtx_lock(&ps->ps_mtx);
 3300         ps->ps_refcnt++;
 3301         mtx_unlock(&ps->ps_mtx);
 3302         return (ps);
 3303 }
 3304 
 3305 void
 3306 sigacts_copy(struct sigacts *dest, struct sigacts *src)
 3307 {
 3308 
 3309         KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest"));
 3310         mtx_lock(&src->ps_mtx);
 3311         bcopy(src, dest, offsetof(struct sigacts, ps_refcnt));
 3312         mtx_unlock(&src->ps_mtx);
 3313 }
 3314 
 3315 int
 3316 sigacts_shared(struct sigacts *ps)
 3317 {
 3318         int shared;
 3319 
 3320         mtx_lock(&ps->ps_mtx);
 3321         shared = ps->ps_refcnt > 1;
 3322         mtx_unlock(&ps->ps_mtx);
 3323         return (shared);
 3324 }

Cache object: cb7ef923469f2c266b85c5d2edd33862


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