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


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

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    1 /*-
    2  * Copyright (c) 1982, 1986, 1989, 1991, 1993
    3  *      The Regents of the University of California.  All rights reserved.
    4  * (c) UNIX System Laboratories, Inc.
    5  * All or some portions of this file are derived from material licensed
    6  * to the University of California by American Telephone and Telegraph
    7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
    8  * the permission of UNIX System Laboratories, Inc.
    9  *
   10  * Redistribution and use in source and binary forms, with or without
   11  * modification, are permitted provided that the following conditions
   12  * are met:
   13  * 1. Redistributions of source code must retain the above copyright
   14  *    notice, this list of conditions and the following disclaimer.
   15  * 2. Redistributions in binary form must reproduce the above copyright
   16  *    notice, this list of conditions and the following disclaimer in the
   17  *    documentation and/or other materials provided with the distribution.
   18  * 4. Neither the name of the University nor the names of its contributors
   19  *    may be used to endorse or promote products derived from this software
   20  *    without specific prior written permission.
   21  *
   22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   32  * SUCH DAMAGE.
   33  *
   34  *      @(#)kern_sig.c  8.7 (Berkeley) 4/18/94
   35  */
   36 
   37 #include <sys/cdefs.h>
   38 __FBSDID("$FreeBSD: releng/10.3/sys/kern/kern_sig.c 289798 2015-10-23 07:40:43Z avg $");
   39 
   40 #include "opt_compat.h"
   41 #include "opt_kdtrace.h"
   42 #include "opt_ktrace.h"
   43 #include "opt_core.h"
   44 #include "opt_procdesc.h"
   45 
   46 #include <sys/param.h>
   47 #include <sys/systm.h>
   48 #include <sys/signalvar.h>
   49 #include <sys/vnode.h>
   50 #include <sys/acct.h>
   51 #include <sys/capsicum.h>
   52 #include <sys/condvar.h>
   53 #include <sys/event.h>
   54 #include <sys/fcntl.h>
   55 #include <sys/imgact.h>
   56 #include <sys/kernel.h>
   57 #include <sys/ktr.h>
   58 #include <sys/ktrace.h>
   59 #include <sys/lock.h>
   60 #include <sys/malloc.h>
   61 #include <sys/mutex.h>
   62 #include <sys/refcount.h>
   63 #include <sys/namei.h>
   64 #include <sys/proc.h>
   65 #include <sys/procdesc.h>
   66 #include <sys/posix4.h>
   67 #include <sys/pioctl.h>
   68 #include <sys/racct.h>
   69 #include <sys/resourcevar.h>
   70 #include <sys/sdt.h>
   71 #include <sys/sbuf.h>
   72 #include <sys/sleepqueue.h>
   73 #include <sys/smp.h>
   74 #include <sys/stat.h>
   75 #include <sys/sx.h>
   76 #include <sys/syscallsubr.h>
   77 #include <sys/sysctl.h>
   78 #include <sys/sysent.h>
   79 #include <sys/syslog.h>
   80 #include <sys/sysproto.h>
   81 #include <sys/timers.h>
   82 #include <sys/unistd.h>
   83 #include <sys/wait.h>
   84 #include <vm/vm.h>
   85 #include <vm/vm_extern.h>
   86 #include <vm/uma.h>
   87 
   88 #include <sys/jail.h>
   89 
   90 #include <machine/cpu.h>
   91 
   92 #include <security/audit/audit.h>
   93 
   94 #define ONSIG   32              /* NSIG for osig* syscalls.  XXX. */
   95 
   96 SDT_PROVIDER_DECLARE(proc);
   97 SDT_PROBE_DEFINE3(proc, kernel, , signal__send, "struct thread *",
   98     "struct proc *", "int");
   99 SDT_PROBE_DEFINE2(proc, kernel, , signal__clear, "int",
  100     "ksiginfo_t *");
  101 SDT_PROBE_DEFINE3(proc, kernel, , signal__discard,
  102     "struct thread *", "struct proc *", "int");
  103 
  104 static int      coredump(struct thread *);
  105 static int      killpg1(struct thread *td, int sig, int pgid, int all,
  106                     ksiginfo_t *ksi);
  107 static int      issignal(struct thread *td);
  108 static int      sigprop(int sig);
  109 static void     tdsigwakeup(struct thread *, int, sig_t, int);
  110 static void     sig_suspend_threads(struct thread *, struct proc *, int);
  111 static int      filt_sigattach(struct knote *kn);
  112 static void     filt_sigdetach(struct knote *kn);
  113 static int      filt_signal(struct knote *kn, long hint);
  114 static struct thread *sigtd(struct proc *p, int sig, int prop);
  115 static void     sigqueue_start(void);
  116 
  117 static uma_zone_t       ksiginfo_zone = NULL;
  118 struct filterops sig_filtops = {
  119         .f_isfd = 0,
  120         .f_attach = filt_sigattach,
  121         .f_detach = filt_sigdetach,
  122         .f_event = filt_signal,
  123 };
  124 
  125 static int      kern_logsigexit = 1;
  126 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
  127     &kern_logsigexit, 0,
  128     "Log processes quitting on abnormal signals to syslog(3)");
  129 
  130 static int      kern_forcesigexit = 1;
  131 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW,
  132     &kern_forcesigexit, 0, "Force trap signal to be handled");
  133 
  134 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0,
  135     "POSIX real time signal");
  136 
  137 static int      max_pending_per_proc = 128;
  138 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW,
  139     &max_pending_per_proc, 0, "Max pending signals per proc");
  140 
  141 static int      preallocate_siginfo = 1024;
  142 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo);
  143 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD,
  144     &preallocate_siginfo, 0, "Preallocated signal memory size");
  145 
  146 static int      signal_overflow = 0;
  147 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD,
  148     &signal_overflow, 0, "Number of signals overflew");
  149 
  150 static int      signal_alloc_fail = 0;
  151 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD,
  152     &signal_alloc_fail, 0, "signals failed to be allocated");
  153 
  154 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL);
  155 
  156 /*
  157  * Policy -- Can ucred cr1 send SIGIO to process cr2?
  158  * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG
  159  * in the right situations.
  160  */
  161 #define CANSIGIO(cr1, cr2) \
  162         ((cr1)->cr_uid == 0 || \
  163             (cr1)->cr_ruid == (cr2)->cr_ruid || \
  164             (cr1)->cr_uid == (cr2)->cr_ruid || \
  165             (cr1)->cr_ruid == (cr2)->cr_uid || \
  166             (cr1)->cr_uid == (cr2)->cr_uid)
  167 
  168 static int      sugid_coredump;
  169 TUNABLE_INT("kern.sugid_coredump", &sugid_coredump);
  170 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
  171     &sugid_coredump, 0, "Allow setuid and setgid processes to dump core");
  172 
  173 static int      capmode_coredump;
  174 TUNABLE_INT("kern.capmode_coredump", &capmode_coredump);
  175 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RW,
  176     &capmode_coredump, 0, "Allow processes in capability mode to dump core");
  177 
  178 static int      do_coredump = 1;
  179 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
  180         &do_coredump, 0, "Enable/Disable coredumps");
  181 
  182 static int      set_core_nodump_flag = 0;
  183 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag,
  184         0, "Enable setting the NODUMP flag on coredump files");
  185 
  186 /*
  187  * Signal properties and actions.
  188  * The array below categorizes the signals and their default actions
  189  * according to the following properties:
  190  */
  191 #define SA_KILL         0x01            /* terminates process by default */
  192 #define SA_CORE         0x02            /* ditto and coredumps */
  193 #define SA_STOP         0x04            /* suspend process */
  194 #define SA_TTYSTOP      0x08            /* ditto, from tty */
  195 #define SA_IGNORE       0x10            /* ignore by default */
  196 #define SA_CONT         0x20            /* continue if suspended */
  197 #define SA_CANTMASK     0x40            /* non-maskable, catchable */
  198 
  199 static int sigproptbl[NSIG] = {
  200         SA_KILL,                        /* SIGHUP */
  201         SA_KILL,                        /* SIGINT */
  202         SA_KILL|SA_CORE,                /* SIGQUIT */
  203         SA_KILL|SA_CORE,                /* SIGILL */
  204         SA_KILL|SA_CORE,                /* SIGTRAP */
  205         SA_KILL|SA_CORE,                /* SIGABRT */
  206         SA_KILL|SA_CORE,                /* SIGEMT */
  207         SA_KILL|SA_CORE,                /* SIGFPE */
  208         SA_KILL,                        /* SIGKILL */
  209         SA_KILL|SA_CORE,                /* SIGBUS */
  210         SA_KILL|SA_CORE,                /* SIGSEGV */
  211         SA_KILL|SA_CORE,                /* SIGSYS */
  212         SA_KILL,                        /* SIGPIPE */
  213         SA_KILL,                        /* SIGALRM */
  214         SA_KILL,                        /* SIGTERM */
  215         SA_IGNORE,                      /* SIGURG */
  216         SA_STOP,                        /* SIGSTOP */
  217         SA_STOP|SA_TTYSTOP,             /* SIGTSTP */
  218         SA_IGNORE|SA_CONT,              /* SIGCONT */
  219         SA_IGNORE,                      /* SIGCHLD */
  220         SA_STOP|SA_TTYSTOP,             /* SIGTTIN */
  221         SA_STOP|SA_TTYSTOP,             /* SIGTTOU */
  222         SA_IGNORE,                      /* SIGIO */
  223         SA_KILL,                        /* SIGXCPU */
  224         SA_KILL,                        /* SIGXFSZ */
  225         SA_KILL,                        /* SIGVTALRM */
  226         SA_KILL,                        /* SIGPROF */
  227         SA_IGNORE,                      /* SIGWINCH  */
  228         SA_IGNORE,                      /* SIGINFO */
  229         SA_KILL,                        /* SIGUSR1 */
  230         SA_KILL,                        /* SIGUSR2 */
  231 };
  232 
  233 static void reschedule_signals(struct proc *p, sigset_t block, int flags);
  234 
  235 static void
  236 sigqueue_start(void)
  237 {
  238         ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t),
  239                 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
  240         uma_prealloc(ksiginfo_zone, preallocate_siginfo);
  241         p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS);
  242         p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1);
  243         p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc);
  244 }
  245 
  246 ksiginfo_t *
  247 ksiginfo_alloc(int wait)
  248 {
  249         int flags;
  250 
  251         flags = M_ZERO;
  252         if (! wait)
  253                 flags |= M_NOWAIT;
  254         if (ksiginfo_zone != NULL)
  255                 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags));
  256         return (NULL);
  257 }
  258 
  259 void
  260 ksiginfo_free(ksiginfo_t *ksi)
  261 {
  262         uma_zfree(ksiginfo_zone, ksi);
  263 }
  264 
  265 static __inline int
  266 ksiginfo_tryfree(ksiginfo_t *ksi)
  267 {
  268         if (!(ksi->ksi_flags & KSI_EXT)) {
  269                 uma_zfree(ksiginfo_zone, ksi);
  270                 return (1);
  271         }
  272         return (0);
  273 }
  274 
  275 void
  276 sigqueue_init(sigqueue_t *list, struct proc *p)
  277 {
  278         SIGEMPTYSET(list->sq_signals);
  279         SIGEMPTYSET(list->sq_kill);
  280         TAILQ_INIT(&list->sq_list);
  281         list->sq_proc = p;
  282         list->sq_flags = SQ_INIT;
  283 }
  284 
  285 /*
  286  * Get a signal's ksiginfo.
  287  * Return:
  288  *      0       -       signal not found
  289  *      others  -       signal number
  290  */
  291 static int
  292 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si)
  293 {
  294         struct proc *p = sq->sq_proc;
  295         struct ksiginfo *ksi, *next;
  296         int count = 0;
  297 
  298         KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
  299 
  300         if (!SIGISMEMBER(sq->sq_signals, signo))
  301                 return (0);
  302 
  303         if (SIGISMEMBER(sq->sq_kill, signo)) {
  304                 count++;
  305                 SIGDELSET(sq->sq_kill, signo);
  306         }
  307 
  308         TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
  309                 if (ksi->ksi_signo == signo) {
  310                         if (count == 0) {
  311                                 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
  312                                 ksi->ksi_sigq = NULL;
  313                                 ksiginfo_copy(ksi, si);
  314                                 if (ksiginfo_tryfree(ksi) && p != NULL)
  315                                         p->p_pendingcnt--;
  316                         }
  317                         if (++count > 1)
  318                                 break;
  319                 }
  320         }
  321 
  322         if (count <= 1)
  323                 SIGDELSET(sq->sq_signals, signo);
  324         si->ksi_signo = signo;
  325         return (signo);
  326 }
  327 
  328 void
  329 sigqueue_take(ksiginfo_t *ksi)
  330 {
  331         struct ksiginfo *kp;
  332         struct proc     *p;
  333         sigqueue_t      *sq;
  334 
  335         if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL)
  336                 return;
  337 
  338         p = sq->sq_proc;
  339         TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
  340         ksi->ksi_sigq = NULL;
  341         if (!(ksi->ksi_flags & KSI_EXT) && p != NULL)
  342                 p->p_pendingcnt--;
  343 
  344         for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL;
  345              kp = TAILQ_NEXT(kp, ksi_link)) {
  346                 if (kp->ksi_signo == ksi->ksi_signo)
  347                         break;
  348         }
  349         if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo))
  350                 SIGDELSET(sq->sq_signals, ksi->ksi_signo);
  351 }
  352 
  353 static int
  354 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si)
  355 {
  356         struct proc *p = sq->sq_proc;
  357         struct ksiginfo *ksi;
  358         int ret = 0;
  359 
  360         KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
  361 
  362         if (signo == SIGKILL || signo == SIGSTOP || si == NULL) {
  363                 SIGADDSET(sq->sq_kill, signo);
  364                 goto out_set_bit;
  365         }
  366 
  367         /* directly insert the ksi, don't copy it */
  368         if (si->ksi_flags & KSI_INS) {
  369                 if (si->ksi_flags & KSI_HEAD)
  370                         TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link);
  371                 else
  372                         TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link);
  373                 si->ksi_sigq = sq;
  374                 goto out_set_bit;
  375         }
  376 
  377         if (__predict_false(ksiginfo_zone == NULL)) {
  378                 SIGADDSET(sq->sq_kill, signo);
  379                 goto out_set_bit;
  380         }
  381 
  382         if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) {
  383                 signal_overflow++;
  384                 ret = EAGAIN;
  385         } else if ((ksi = ksiginfo_alloc(0)) == NULL) {
  386                 signal_alloc_fail++;
  387                 ret = EAGAIN;
  388         } else {
  389                 if (p != NULL)
  390                         p->p_pendingcnt++;
  391                 ksiginfo_copy(si, ksi);
  392                 ksi->ksi_signo = signo;
  393                 if (si->ksi_flags & KSI_HEAD)
  394                         TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link);
  395                 else
  396                         TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link);
  397                 ksi->ksi_sigq = sq;
  398         }
  399 
  400         if ((si->ksi_flags & KSI_TRAP) != 0 ||
  401             (si->ksi_flags & KSI_SIGQ) == 0) {
  402                 if (ret != 0)
  403                         SIGADDSET(sq->sq_kill, signo);
  404                 ret = 0;
  405                 goto out_set_bit;
  406         }
  407 
  408         if (ret != 0)
  409                 return (ret);
  410 
  411 out_set_bit:
  412         SIGADDSET(sq->sq_signals, signo);
  413         return (ret);
  414 }
  415 
  416 void
  417 sigqueue_flush(sigqueue_t *sq)
  418 {
  419         struct proc *p = sq->sq_proc;
  420         ksiginfo_t *ksi;
  421 
  422         KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
  423 
  424         if (p != NULL)
  425                 PROC_LOCK_ASSERT(p, MA_OWNED);
  426 
  427         while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) {
  428                 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
  429                 ksi->ksi_sigq = NULL;
  430                 if (ksiginfo_tryfree(ksi) && p != NULL)
  431                         p->p_pendingcnt--;
  432         }
  433 
  434         SIGEMPTYSET(sq->sq_signals);
  435         SIGEMPTYSET(sq->sq_kill);
  436 }
  437 
  438 static void
  439 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set)
  440 {
  441         sigset_t tmp;
  442         struct proc *p1, *p2;
  443         ksiginfo_t *ksi, *next;
  444 
  445         KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited"));
  446         KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited"));
  447         p1 = src->sq_proc;
  448         p2 = dst->sq_proc;
  449         /* Move siginfo to target list */
  450         TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) {
  451                 if (SIGISMEMBER(*set, ksi->ksi_signo)) {
  452                         TAILQ_REMOVE(&src->sq_list, ksi, ksi_link);
  453                         if (p1 != NULL)
  454                                 p1->p_pendingcnt--;
  455                         TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link);
  456                         ksi->ksi_sigq = dst;
  457                         if (p2 != NULL)
  458                                 p2->p_pendingcnt++;
  459                 }
  460         }
  461 
  462         /* Move pending bits to target list */
  463         tmp = src->sq_kill;
  464         SIGSETAND(tmp, *set);
  465         SIGSETOR(dst->sq_kill, tmp);
  466         SIGSETNAND(src->sq_kill, tmp);
  467 
  468         tmp = src->sq_signals;
  469         SIGSETAND(tmp, *set);
  470         SIGSETOR(dst->sq_signals, tmp);
  471         SIGSETNAND(src->sq_signals, tmp);
  472 }
  473 
  474 #if 0
  475 static void
  476 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo)
  477 {
  478         sigset_t set;
  479 
  480         SIGEMPTYSET(set);
  481         SIGADDSET(set, signo);
  482         sigqueue_move_set(src, dst, &set);
  483 }
  484 #endif
  485 
  486 static void
  487 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set)
  488 {
  489         struct proc *p = sq->sq_proc;
  490         ksiginfo_t *ksi, *next;
  491 
  492         KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited"));
  493 
  494         /* Remove siginfo queue */
  495         TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
  496                 if (SIGISMEMBER(*set, ksi->ksi_signo)) {
  497                         TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
  498                         ksi->ksi_sigq = NULL;
  499                         if (ksiginfo_tryfree(ksi) && p != NULL)
  500                                 p->p_pendingcnt--;
  501                 }
  502         }
  503         SIGSETNAND(sq->sq_kill, *set);
  504         SIGSETNAND(sq->sq_signals, *set);
  505 }
  506 
  507 void
  508 sigqueue_delete(sigqueue_t *sq, int signo)
  509 {
  510         sigset_t set;
  511 
  512         SIGEMPTYSET(set);
  513         SIGADDSET(set, signo);
  514         sigqueue_delete_set(sq, &set);
  515 }
  516 
  517 /* Remove a set of signals for a process */
  518 static void
  519 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set)
  520 {
  521         sigqueue_t worklist;
  522         struct thread *td0;
  523 
  524         PROC_LOCK_ASSERT(p, MA_OWNED);
  525 
  526         sigqueue_init(&worklist, NULL);
  527         sigqueue_move_set(&p->p_sigqueue, &worklist, set);
  528 
  529         FOREACH_THREAD_IN_PROC(p, td0)
  530                 sigqueue_move_set(&td0->td_sigqueue, &worklist, set);
  531 
  532         sigqueue_flush(&worklist);
  533 }
  534 
  535 void
  536 sigqueue_delete_proc(struct proc *p, int signo)
  537 {
  538         sigset_t set;
  539 
  540         SIGEMPTYSET(set);
  541         SIGADDSET(set, signo);
  542         sigqueue_delete_set_proc(p, &set);
  543 }
  544 
  545 static void
  546 sigqueue_delete_stopmask_proc(struct proc *p)
  547 {
  548         sigset_t set;
  549 
  550         SIGEMPTYSET(set);
  551         SIGADDSET(set, SIGSTOP);
  552         SIGADDSET(set, SIGTSTP);
  553         SIGADDSET(set, SIGTTIN);
  554         SIGADDSET(set, SIGTTOU);
  555         sigqueue_delete_set_proc(p, &set);
  556 }
  557 
  558 /*
  559  * Determine signal that should be delivered to thread td, the current
  560  * thread, 0 if none.  If there is a pending stop signal with default
  561  * action, the process stops in issignal().
  562  */
  563 int
  564 cursig(struct thread *td)
  565 {
  566         PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
  567         mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED);
  568         THREAD_LOCK_ASSERT(td, MA_NOTOWNED);
  569         return (SIGPENDING(td) ? issignal(td) : 0);
  570 }
  571 
  572 /*
  573  * Arrange for ast() to handle unmasked pending signals on return to user
  574  * mode.  This must be called whenever a signal is added to td_sigqueue or
  575  * unmasked in td_sigmask.
  576  */
  577 void
  578 signotify(struct thread *td)
  579 {
  580         struct proc *p;
  581 
  582         p = td->td_proc;
  583 
  584         PROC_LOCK_ASSERT(p, MA_OWNED);
  585 
  586         if (SIGPENDING(td)) {
  587                 thread_lock(td);
  588                 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING;
  589                 thread_unlock(td);
  590         }
  591 }
  592 
  593 int
  594 sigonstack(size_t sp)
  595 {
  596         struct thread *td = curthread;
  597 
  598         return ((td->td_pflags & TDP_ALTSTACK) ?
  599 #if defined(COMPAT_43)
  600             ((td->td_sigstk.ss_size == 0) ?
  601                 (td->td_sigstk.ss_flags & SS_ONSTACK) :
  602                 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size))
  603 #else
  604             ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)
  605 #endif
  606             : 0);
  607 }
  608 
  609 static __inline int
  610 sigprop(int sig)
  611 {
  612 
  613         if (sig > 0 && sig < NSIG)
  614                 return (sigproptbl[_SIG_IDX(sig)]);
  615         return (0);
  616 }
  617 
  618 int
  619 sig_ffs(sigset_t *set)
  620 {
  621         int i;
  622 
  623         for (i = 0; i < _SIG_WORDS; i++)
  624                 if (set->__bits[i])
  625                         return (ffs(set->__bits[i]) + (i * 32));
  626         return (0);
  627 }
  628 
  629 static bool
  630 sigact_flag_test(struct sigaction *act, int flag)
  631 {
  632 
  633         /*
  634          * SA_SIGINFO is reset when signal disposition is set to
  635          * ignore or default.  Other flags are kept according to user
  636          * settings.
  637          */
  638         return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO ||
  639             ((__sighandler_t *)act->sa_sigaction != SIG_IGN &&
  640             (__sighandler_t *)act->sa_sigaction != SIG_DFL)));
  641 }
  642 
  643 /*
  644  * kern_sigaction
  645  * sigaction
  646  * freebsd4_sigaction
  647  * osigaction
  648  */
  649 int
  650 kern_sigaction(td, sig, act, oact, flags)
  651         struct thread *td;
  652         register int sig;
  653         struct sigaction *act, *oact;
  654         int flags;
  655 {
  656         struct sigacts *ps;
  657         struct proc *p = td->td_proc;
  658 
  659         if (!_SIG_VALID(sig))
  660                 return (EINVAL);
  661         if (act != NULL && act->sa_handler != SIG_DFL &&
  662             act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK |
  663             SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER |
  664             SA_NOCLDWAIT | SA_SIGINFO)) != 0)
  665                 return (EINVAL);
  666 
  667         PROC_LOCK(p);
  668         ps = p->p_sigacts;
  669         mtx_lock(&ps->ps_mtx);
  670         if (oact) {
  671                 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
  672                 oact->sa_flags = 0;
  673                 if (SIGISMEMBER(ps->ps_sigonstack, sig))
  674                         oact->sa_flags |= SA_ONSTACK;
  675                 if (!SIGISMEMBER(ps->ps_sigintr, sig))
  676                         oact->sa_flags |= SA_RESTART;
  677                 if (SIGISMEMBER(ps->ps_sigreset, sig))
  678                         oact->sa_flags |= SA_RESETHAND;
  679                 if (SIGISMEMBER(ps->ps_signodefer, sig))
  680                         oact->sa_flags |= SA_NODEFER;
  681                 if (SIGISMEMBER(ps->ps_siginfo, sig)) {
  682                         oact->sa_flags |= SA_SIGINFO;
  683                         oact->sa_sigaction =
  684                             (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)];
  685                 } else
  686                         oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
  687                 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP)
  688                         oact->sa_flags |= SA_NOCLDSTOP;
  689                 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT)
  690                         oact->sa_flags |= SA_NOCLDWAIT;
  691         }
  692         if (act) {
  693                 if ((sig == SIGKILL || sig == SIGSTOP) &&
  694                     act->sa_handler != SIG_DFL) {
  695                         mtx_unlock(&ps->ps_mtx);
  696                         PROC_UNLOCK(p);
  697                         return (EINVAL);
  698                 }
  699 
  700                 /*
  701                  * Change setting atomically.
  702                  */
  703 
  704                 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
  705                 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
  706                 if (sigact_flag_test(act, SA_SIGINFO)) {
  707                         ps->ps_sigact[_SIG_IDX(sig)] =
  708                             (__sighandler_t *)act->sa_sigaction;
  709                         SIGADDSET(ps->ps_siginfo, sig);
  710                 } else {
  711                         ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
  712                         SIGDELSET(ps->ps_siginfo, sig);
  713                 }
  714                 if (!sigact_flag_test(act, SA_RESTART))
  715                         SIGADDSET(ps->ps_sigintr, sig);
  716                 else
  717                         SIGDELSET(ps->ps_sigintr, sig);
  718                 if (sigact_flag_test(act, SA_ONSTACK))
  719                         SIGADDSET(ps->ps_sigonstack, sig);
  720                 else
  721                         SIGDELSET(ps->ps_sigonstack, sig);
  722                 if (sigact_flag_test(act, SA_RESETHAND))
  723                         SIGADDSET(ps->ps_sigreset, sig);
  724                 else
  725                         SIGDELSET(ps->ps_sigreset, sig);
  726                 if (sigact_flag_test(act, SA_NODEFER))
  727                         SIGADDSET(ps->ps_signodefer, sig);
  728                 else
  729                         SIGDELSET(ps->ps_signodefer, sig);
  730                 if (sig == SIGCHLD) {
  731                         if (act->sa_flags & SA_NOCLDSTOP)
  732                                 ps->ps_flag |= PS_NOCLDSTOP;
  733                         else
  734                                 ps->ps_flag &= ~PS_NOCLDSTOP;
  735                         if (act->sa_flags & SA_NOCLDWAIT) {
  736                                 /*
  737                                  * Paranoia: since SA_NOCLDWAIT is implemented
  738                                  * by reparenting the dying child to PID 1 (and
  739                                  * trust it to reap the zombie), PID 1 itself
  740                                  * is forbidden to set SA_NOCLDWAIT.
  741                                  */
  742                                 if (p->p_pid == 1)
  743                                         ps->ps_flag &= ~PS_NOCLDWAIT;
  744                                 else
  745                                         ps->ps_flag |= PS_NOCLDWAIT;
  746                         } else
  747                                 ps->ps_flag &= ~PS_NOCLDWAIT;
  748                         if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
  749                                 ps->ps_flag |= PS_CLDSIGIGN;
  750                         else
  751                                 ps->ps_flag &= ~PS_CLDSIGIGN;
  752                 }
  753                 /*
  754                  * Set bit in ps_sigignore for signals that are set to SIG_IGN,
  755                  * and for signals set to SIG_DFL where the default is to
  756                  * ignore. However, don't put SIGCONT in ps_sigignore, as we
  757                  * have to restart the process.
  758                  */
  759                 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
  760                     (sigprop(sig) & SA_IGNORE &&
  761                      ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
  762                         /* never to be seen again */
  763                         sigqueue_delete_proc(p, sig);
  764                         if (sig != SIGCONT)
  765                                 /* easier in psignal */
  766                                 SIGADDSET(ps->ps_sigignore, sig);
  767                         SIGDELSET(ps->ps_sigcatch, sig);
  768                 } else {
  769                         SIGDELSET(ps->ps_sigignore, sig);
  770                         if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
  771                                 SIGDELSET(ps->ps_sigcatch, sig);
  772                         else
  773                                 SIGADDSET(ps->ps_sigcatch, sig);
  774                 }
  775 #ifdef COMPAT_FREEBSD4
  776                 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
  777                     ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
  778                     (flags & KSA_FREEBSD4) == 0)
  779                         SIGDELSET(ps->ps_freebsd4, sig);
  780                 else
  781                         SIGADDSET(ps->ps_freebsd4, sig);
  782 #endif
  783 #ifdef COMPAT_43
  784                 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
  785                     ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
  786                     (flags & KSA_OSIGSET) == 0)
  787                         SIGDELSET(ps->ps_osigset, sig);
  788                 else
  789                         SIGADDSET(ps->ps_osigset, sig);
  790 #endif
  791         }
  792         mtx_unlock(&ps->ps_mtx);
  793         PROC_UNLOCK(p);
  794         return (0);
  795 }
  796 
  797 #ifndef _SYS_SYSPROTO_H_
  798 struct sigaction_args {
  799         int     sig;
  800         struct  sigaction *act;
  801         struct  sigaction *oact;
  802 };
  803 #endif
  804 int
  805 sys_sigaction(td, uap)
  806         struct thread *td;
  807         register struct sigaction_args *uap;
  808 {
  809         struct sigaction act, oact;
  810         register struct sigaction *actp, *oactp;
  811         int error;
  812 
  813         actp = (uap->act != NULL) ? &act : NULL;
  814         oactp = (uap->oact != NULL) ? &oact : NULL;
  815         if (actp) {
  816                 error = copyin(uap->act, actp, sizeof(act));
  817                 if (error)
  818                         return (error);
  819         }
  820         error = kern_sigaction(td, uap->sig, actp, oactp, 0);
  821         if (oactp && !error)
  822                 error = copyout(oactp, uap->oact, sizeof(oact));
  823         return (error);
  824 }
  825 
  826 #ifdef COMPAT_FREEBSD4
  827 #ifndef _SYS_SYSPROTO_H_
  828 struct freebsd4_sigaction_args {
  829         int     sig;
  830         struct  sigaction *act;
  831         struct  sigaction *oact;
  832 };
  833 #endif
  834 int
  835 freebsd4_sigaction(td, uap)
  836         struct thread *td;
  837         register struct freebsd4_sigaction_args *uap;
  838 {
  839         struct sigaction act, oact;
  840         register struct sigaction *actp, *oactp;
  841         int error;
  842 
  843 
  844         actp = (uap->act != NULL) ? &act : NULL;
  845         oactp = (uap->oact != NULL) ? &oact : NULL;
  846         if (actp) {
  847                 error = copyin(uap->act, actp, sizeof(act));
  848                 if (error)
  849                         return (error);
  850         }
  851         error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4);
  852         if (oactp && !error)
  853                 error = copyout(oactp, uap->oact, sizeof(oact));
  854         return (error);
  855 }
  856 #endif  /* COMAPT_FREEBSD4 */
  857 
  858 #ifdef COMPAT_43        /* XXX - COMPAT_FBSD3 */
  859 #ifndef _SYS_SYSPROTO_H_
  860 struct osigaction_args {
  861         int     signum;
  862         struct  osigaction *nsa;
  863         struct  osigaction *osa;
  864 };
  865 #endif
  866 int
  867 osigaction(td, uap)
  868         struct thread *td;
  869         register struct osigaction_args *uap;
  870 {
  871         struct osigaction sa;
  872         struct sigaction nsa, osa;
  873         register struct sigaction *nsap, *osap;
  874         int error;
  875 
  876         if (uap->signum <= 0 || uap->signum >= ONSIG)
  877                 return (EINVAL);
  878 
  879         nsap = (uap->nsa != NULL) ? &nsa : NULL;
  880         osap = (uap->osa != NULL) ? &osa : NULL;
  881 
  882         if (nsap) {
  883                 error = copyin(uap->nsa, &sa, sizeof(sa));
  884                 if (error)
  885                         return (error);
  886                 nsap->sa_handler = sa.sa_handler;
  887                 nsap->sa_flags = sa.sa_flags;
  888                 OSIG2SIG(sa.sa_mask, nsap->sa_mask);
  889         }
  890         error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
  891         if (osap && !error) {
  892                 sa.sa_handler = osap->sa_handler;
  893                 sa.sa_flags = osap->sa_flags;
  894                 SIG2OSIG(osap->sa_mask, sa.sa_mask);
  895                 error = copyout(&sa, uap->osa, sizeof(sa));
  896         }
  897         return (error);
  898 }
  899 
  900 #if !defined(__i386__)
  901 /* Avoid replicating the same stub everywhere */
  902 int
  903 osigreturn(td, uap)
  904         struct thread *td;
  905         struct osigreturn_args *uap;
  906 {
  907 
  908         return (nosys(td, (struct nosys_args *)uap));
  909 }
  910 #endif
  911 #endif /* COMPAT_43 */
  912 
  913 /*
  914  * Initialize signal state for process 0;
  915  * set to ignore signals that are ignored by default.
  916  */
  917 void
  918 siginit(p)
  919         struct proc *p;
  920 {
  921         register int i;
  922         struct sigacts *ps;
  923 
  924         PROC_LOCK(p);
  925         ps = p->p_sigacts;
  926         mtx_lock(&ps->ps_mtx);
  927         for (i = 1; i <= NSIG; i++) {
  928                 if (sigprop(i) & SA_IGNORE && i != SIGCONT) {
  929                         SIGADDSET(ps->ps_sigignore, i);
  930                 }
  931         }
  932         mtx_unlock(&ps->ps_mtx);
  933         PROC_UNLOCK(p);
  934 }
  935 
  936 /*
  937  * Reset specified signal to the default disposition.
  938  */
  939 static void
  940 sigdflt(struct sigacts *ps, int sig)
  941 {
  942 
  943         mtx_assert(&ps->ps_mtx, MA_OWNED);
  944         SIGDELSET(ps->ps_sigcatch, sig);
  945         if ((sigprop(sig) & SA_IGNORE) != 0 && sig != SIGCONT)
  946                 SIGADDSET(ps->ps_sigignore, sig);
  947         ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
  948         SIGDELSET(ps->ps_siginfo, sig);
  949 }
  950 
  951 /*
  952  * Reset signals for an exec of the specified process.
  953  */
  954 void
  955 execsigs(struct proc *p)
  956 {
  957         struct sigacts *ps;
  958         int sig;
  959         struct thread *td;
  960 
  961         /*
  962          * Reset caught signals.  Held signals remain held
  963          * through td_sigmask (unless they were caught,
  964          * and are now ignored by default).
  965          */
  966         PROC_LOCK_ASSERT(p, MA_OWNED);
  967         td = FIRST_THREAD_IN_PROC(p);
  968         ps = p->p_sigacts;
  969         mtx_lock(&ps->ps_mtx);
  970         while (SIGNOTEMPTY(ps->ps_sigcatch)) {
  971                 sig = sig_ffs(&ps->ps_sigcatch);
  972                 sigdflt(ps, sig);
  973                 if ((sigprop(sig) & SA_IGNORE) != 0)
  974                         sigqueue_delete_proc(p, sig);
  975         }
  976         /*
  977          * Reset stack state to the user stack.
  978          * Clear set of signals caught on the signal stack.
  979          */
  980         td->td_sigstk.ss_flags = SS_DISABLE;
  981         td->td_sigstk.ss_size = 0;
  982         td->td_sigstk.ss_sp = 0;
  983         td->td_pflags &= ~TDP_ALTSTACK;
  984         /*
  985          * Reset no zombies if child dies flag as Solaris does.
  986          */
  987         ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN);
  988         if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
  989                 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL;
  990         mtx_unlock(&ps->ps_mtx);
  991 }
  992 
  993 /*
  994  * kern_sigprocmask()
  995  *
  996  *      Manipulate signal mask.
  997  */
  998 int
  999 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset,
 1000     int flags)
 1001 {
 1002         sigset_t new_block, oset1;
 1003         struct proc *p;
 1004         int error;
 1005 
 1006         p = td->td_proc;
 1007         if ((flags & SIGPROCMASK_PROC_LOCKED) != 0)
 1008                 PROC_LOCK_ASSERT(p, MA_OWNED);
 1009         else
 1010                 PROC_LOCK(p);
 1011         mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0
 1012             ? MA_OWNED : MA_NOTOWNED);
 1013         if (oset != NULL)
 1014                 *oset = td->td_sigmask;
 1015 
 1016         error = 0;
 1017         if (set != NULL) {
 1018                 switch (how) {
 1019                 case SIG_BLOCK:
 1020                         SIG_CANTMASK(*set);
 1021                         oset1 = td->td_sigmask;
 1022                         SIGSETOR(td->td_sigmask, *set);
 1023                         new_block = td->td_sigmask;
 1024                         SIGSETNAND(new_block, oset1);
 1025                         break;
 1026                 case SIG_UNBLOCK:
 1027                         SIGSETNAND(td->td_sigmask, *set);
 1028                         signotify(td);
 1029                         goto out;
 1030                 case SIG_SETMASK:
 1031                         SIG_CANTMASK(*set);
 1032                         oset1 = td->td_sigmask;
 1033                         if (flags & SIGPROCMASK_OLD)
 1034                                 SIGSETLO(td->td_sigmask, *set);
 1035                         else
 1036                                 td->td_sigmask = *set;
 1037                         new_block = td->td_sigmask;
 1038                         SIGSETNAND(new_block, oset1);
 1039                         signotify(td);
 1040                         break;
 1041                 default:
 1042                         error = EINVAL;
 1043                         goto out;
 1044                 }
 1045 
 1046                 /*
 1047                  * The new_block set contains signals that were not previously
 1048                  * blocked, but are blocked now.
 1049                  *
 1050                  * In case we block any signal that was not previously blocked
 1051                  * for td, and process has the signal pending, try to schedule
 1052                  * signal delivery to some thread that does not block the
 1053                  * signal, possibly waking it up.
 1054                  */
 1055                 if (p->p_numthreads != 1)
 1056                         reschedule_signals(p, new_block, flags);
 1057         }
 1058 
 1059 out:
 1060         if (!(flags & SIGPROCMASK_PROC_LOCKED))
 1061                 PROC_UNLOCK(p);
 1062         return (error);
 1063 }
 1064 
 1065 #ifndef _SYS_SYSPROTO_H_
 1066 struct sigprocmask_args {
 1067         int     how;
 1068         const sigset_t *set;
 1069         sigset_t *oset;
 1070 };
 1071 #endif
 1072 int
 1073 sys_sigprocmask(td, uap)
 1074         register struct thread *td;
 1075         struct sigprocmask_args *uap;
 1076 {
 1077         sigset_t set, oset;
 1078         sigset_t *setp, *osetp;
 1079         int error;
 1080 
 1081         setp = (uap->set != NULL) ? &set : NULL;
 1082         osetp = (uap->oset != NULL) ? &oset : NULL;
 1083         if (setp) {
 1084                 error = copyin(uap->set, setp, sizeof(set));
 1085                 if (error)
 1086                         return (error);
 1087         }
 1088         error = kern_sigprocmask(td, uap->how, setp, osetp, 0);
 1089         if (osetp && !error) {
 1090                 error = copyout(osetp, uap->oset, sizeof(oset));
 1091         }
 1092         return (error);
 1093 }
 1094 
 1095 #ifdef COMPAT_43        /* XXX - COMPAT_FBSD3 */
 1096 #ifndef _SYS_SYSPROTO_H_
 1097 struct osigprocmask_args {
 1098         int     how;
 1099         osigset_t mask;
 1100 };
 1101 #endif
 1102 int
 1103 osigprocmask(td, uap)
 1104         register struct thread *td;
 1105         struct osigprocmask_args *uap;
 1106 {
 1107         sigset_t set, oset;
 1108         int error;
 1109 
 1110         OSIG2SIG(uap->mask, set);
 1111         error = kern_sigprocmask(td, uap->how, &set, &oset, 1);
 1112         SIG2OSIG(oset, td->td_retval[0]);
 1113         return (error);
 1114 }
 1115 #endif /* COMPAT_43 */
 1116 
 1117 int
 1118 sys_sigwait(struct thread *td, struct sigwait_args *uap)
 1119 {
 1120         ksiginfo_t ksi;
 1121         sigset_t set;
 1122         int error;
 1123 
 1124         error = copyin(uap->set, &set, sizeof(set));
 1125         if (error) {
 1126                 td->td_retval[0] = error;
 1127                 return (0);
 1128         }
 1129 
 1130         error = kern_sigtimedwait(td, set, &ksi, NULL);
 1131         if (error) {
 1132                 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT)
 1133                         error = ERESTART;
 1134                 if (error == ERESTART)
 1135                         return (error);
 1136                 td->td_retval[0] = error;
 1137                 return (0);
 1138         }
 1139 
 1140         error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo));
 1141         td->td_retval[0] = error;
 1142         return (0);
 1143 }
 1144 
 1145 int
 1146 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap)
 1147 {
 1148         struct timespec ts;
 1149         struct timespec *timeout;
 1150         sigset_t set;
 1151         ksiginfo_t ksi;
 1152         int error;
 1153 
 1154         if (uap->timeout) {
 1155                 error = copyin(uap->timeout, &ts, sizeof(ts));
 1156                 if (error)
 1157                         return (error);
 1158 
 1159                 timeout = &ts;
 1160         } else
 1161                 timeout = NULL;
 1162 
 1163         error = copyin(uap->set, &set, sizeof(set));
 1164         if (error)
 1165                 return (error);
 1166 
 1167         error = kern_sigtimedwait(td, set, &ksi, timeout);
 1168         if (error)
 1169                 return (error);
 1170 
 1171         if (uap->info)
 1172                 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t));
 1173 
 1174         if (error == 0)
 1175                 td->td_retval[0] = ksi.ksi_signo;
 1176         return (error);
 1177 }
 1178 
 1179 int
 1180 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap)
 1181 {
 1182         ksiginfo_t ksi;
 1183         sigset_t set;
 1184         int error;
 1185 
 1186         error = copyin(uap->set, &set, sizeof(set));
 1187         if (error)
 1188                 return (error);
 1189 
 1190         error = kern_sigtimedwait(td, set, &ksi, NULL);
 1191         if (error)
 1192                 return (error);
 1193 
 1194         if (uap->info)
 1195                 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t));
 1196 
 1197         if (error == 0)
 1198                 td->td_retval[0] = ksi.ksi_signo;
 1199         return (error);
 1200 }
 1201 
 1202 int
 1203 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi,
 1204         struct timespec *timeout)
 1205 {
 1206         struct sigacts *ps;
 1207         sigset_t saved_mask, new_block;
 1208         struct proc *p;
 1209         int error, sig, timo, timevalid = 0;
 1210         struct timespec rts, ets, ts;
 1211         struct timeval tv;
 1212 
 1213         p = td->td_proc;
 1214         error = 0;
 1215         ets.tv_sec = 0;
 1216         ets.tv_nsec = 0;
 1217 
 1218         if (timeout != NULL) {
 1219                 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) {
 1220                         timevalid = 1;
 1221                         getnanouptime(&rts);
 1222                         ets = rts;
 1223                         timespecadd(&ets, timeout);
 1224                 }
 1225         }
 1226         ksiginfo_init(ksi);
 1227         /* Some signals can not be waited for. */
 1228         SIG_CANTMASK(waitset);
 1229         ps = p->p_sigacts;
 1230         PROC_LOCK(p);
 1231         saved_mask = td->td_sigmask;
 1232         SIGSETNAND(td->td_sigmask, waitset);
 1233         for (;;) {
 1234                 mtx_lock(&ps->ps_mtx);
 1235                 sig = cursig(td);
 1236                 mtx_unlock(&ps->ps_mtx);
 1237                 if (sig != 0 && SIGISMEMBER(waitset, sig)) {
 1238                         if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 ||
 1239                             sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) {
 1240                                 error = 0;
 1241                                 break;
 1242                         }
 1243                 }
 1244 
 1245                 if (error != 0)
 1246                         break;
 1247 
 1248                 /*
 1249                  * POSIX says this must be checked after looking for pending
 1250                  * signals.
 1251                  */
 1252                 if (timeout != NULL) {
 1253                         if (!timevalid) {
 1254                                 error = EINVAL;
 1255                                 break;
 1256                         }
 1257                         getnanouptime(&rts);
 1258                         if (timespeccmp(&rts, &ets, >=)) {
 1259                                 error = EAGAIN;
 1260                                 break;
 1261                         }
 1262                         ts = ets;
 1263                         timespecsub(&ts, &rts);
 1264                         TIMESPEC_TO_TIMEVAL(&tv, &ts);
 1265                         timo = tvtohz(&tv);
 1266                 } else {
 1267                         timo = 0;
 1268                 }
 1269 
 1270                 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo);
 1271 
 1272                 if (timeout != NULL) {
 1273                         if (error == ERESTART) {
 1274                                 /* Timeout can not be restarted. */
 1275                                 error = EINTR;
 1276                         } else if (error == EAGAIN) {
 1277                                 /* We will calculate timeout by ourself. */
 1278                                 error = 0;
 1279                         }
 1280                 }
 1281         }
 1282 
 1283         new_block = saved_mask;
 1284         SIGSETNAND(new_block, td->td_sigmask);
 1285         td->td_sigmask = saved_mask;
 1286         /*
 1287          * Fewer signals can be delivered to us, reschedule signal
 1288          * notification.
 1289          */
 1290         if (p->p_numthreads != 1)
 1291                 reschedule_signals(p, new_block, 0);
 1292 
 1293         if (error == 0) {
 1294                 SDT_PROBE2(proc, kernel, , signal__clear, sig, ksi);
 1295 
 1296                 if (ksi->ksi_code == SI_TIMER)
 1297                         itimer_accept(p, ksi->ksi_timerid, ksi);
 1298 
 1299 #ifdef KTRACE
 1300                 if (KTRPOINT(td, KTR_PSIG)) {
 1301                         sig_t action;
 1302 
 1303                         mtx_lock(&ps->ps_mtx);
 1304                         action = ps->ps_sigact[_SIG_IDX(sig)];
 1305                         mtx_unlock(&ps->ps_mtx);
 1306                         ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code);
 1307                 }
 1308 #endif
 1309                 if (sig == SIGKILL)
 1310                         sigexit(td, sig);
 1311         }
 1312         PROC_UNLOCK(p);
 1313         return (error);
 1314 }
 1315 
 1316 #ifndef _SYS_SYSPROTO_H_
 1317 struct sigpending_args {
 1318         sigset_t        *set;
 1319 };
 1320 #endif
 1321 int
 1322 sys_sigpending(td, uap)
 1323         struct thread *td;
 1324         struct sigpending_args *uap;
 1325 {
 1326         struct proc *p = td->td_proc;
 1327         sigset_t pending;
 1328 
 1329         PROC_LOCK(p);
 1330         pending = p->p_sigqueue.sq_signals;
 1331         SIGSETOR(pending, td->td_sigqueue.sq_signals);
 1332         PROC_UNLOCK(p);
 1333         return (copyout(&pending, uap->set, sizeof(sigset_t)));
 1334 }
 1335 
 1336 #ifdef COMPAT_43        /* XXX - COMPAT_FBSD3 */
 1337 #ifndef _SYS_SYSPROTO_H_
 1338 struct osigpending_args {
 1339         int     dummy;
 1340 };
 1341 #endif
 1342 int
 1343 osigpending(td, uap)
 1344         struct thread *td;
 1345         struct osigpending_args *uap;
 1346 {
 1347         struct proc *p = td->td_proc;
 1348         sigset_t pending;
 1349 
 1350         PROC_LOCK(p);
 1351         pending = p->p_sigqueue.sq_signals;
 1352         SIGSETOR(pending, td->td_sigqueue.sq_signals);
 1353         PROC_UNLOCK(p);
 1354         SIG2OSIG(pending, td->td_retval[0]);
 1355         return (0);
 1356 }
 1357 #endif /* COMPAT_43 */
 1358 
 1359 #if defined(COMPAT_43)
 1360 /*
 1361  * Generalized interface signal handler, 4.3-compatible.
 1362  */
 1363 #ifndef _SYS_SYSPROTO_H_
 1364 struct osigvec_args {
 1365         int     signum;
 1366         struct  sigvec *nsv;
 1367         struct  sigvec *osv;
 1368 };
 1369 #endif
 1370 /* ARGSUSED */
 1371 int
 1372 osigvec(td, uap)
 1373         struct thread *td;
 1374         register struct osigvec_args *uap;
 1375 {
 1376         struct sigvec vec;
 1377         struct sigaction nsa, osa;
 1378         register struct sigaction *nsap, *osap;
 1379         int error;
 1380 
 1381         if (uap->signum <= 0 || uap->signum >= ONSIG)
 1382                 return (EINVAL);
 1383         nsap = (uap->nsv != NULL) ? &nsa : NULL;
 1384         osap = (uap->osv != NULL) ? &osa : NULL;
 1385         if (nsap) {
 1386                 error = copyin(uap->nsv, &vec, sizeof(vec));
 1387                 if (error)
 1388                         return (error);
 1389                 nsap->sa_handler = vec.sv_handler;
 1390                 OSIG2SIG(vec.sv_mask, nsap->sa_mask);
 1391                 nsap->sa_flags = vec.sv_flags;
 1392                 nsap->sa_flags ^= SA_RESTART;   /* opposite of SV_INTERRUPT */
 1393         }
 1394         error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
 1395         if (osap && !error) {
 1396                 vec.sv_handler = osap->sa_handler;
 1397                 SIG2OSIG(osap->sa_mask, vec.sv_mask);
 1398                 vec.sv_flags = osap->sa_flags;
 1399                 vec.sv_flags &= ~SA_NOCLDWAIT;
 1400                 vec.sv_flags ^= SA_RESTART;
 1401                 error = copyout(&vec, uap->osv, sizeof(vec));
 1402         }
 1403         return (error);
 1404 }
 1405 
 1406 #ifndef _SYS_SYSPROTO_H_
 1407 struct osigblock_args {
 1408         int     mask;
 1409 };
 1410 #endif
 1411 int
 1412 osigblock(td, uap)
 1413         register struct thread *td;
 1414         struct osigblock_args *uap;
 1415 {
 1416         sigset_t set, oset;
 1417 
 1418         OSIG2SIG(uap->mask, set);
 1419         kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0);
 1420         SIG2OSIG(oset, td->td_retval[0]);
 1421         return (0);
 1422 }
 1423 
 1424 #ifndef _SYS_SYSPROTO_H_
 1425 struct osigsetmask_args {
 1426         int     mask;
 1427 };
 1428 #endif
 1429 int
 1430 osigsetmask(td, uap)
 1431         struct thread *td;
 1432         struct osigsetmask_args *uap;
 1433 {
 1434         sigset_t set, oset;
 1435 
 1436         OSIG2SIG(uap->mask, set);
 1437         kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0);
 1438         SIG2OSIG(oset, td->td_retval[0]);
 1439         return (0);
 1440 }
 1441 #endif /* COMPAT_43 */
 1442 
 1443 /*
 1444  * Suspend calling thread until signal, providing mask to be set in the
 1445  * meantime.
 1446  */
 1447 #ifndef _SYS_SYSPROTO_H_
 1448 struct sigsuspend_args {
 1449         const sigset_t *sigmask;
 1450 };
 1451 #endif
 1452 /* ARGSUSED */
 1453 int
 1454 sys_sigsuspend(td, uap)
 1455         struct thread *td;
 1456         struct sigsuspend_args *uap;
 1457 {
 1458         sigset_t mask;
 1459         int error;
 1460 
 1461         error = copyin(uap->sigmask, &mask, sizeof(mask));
 1462         if (error)
 1463                 return (error);
 1464         return (kern_sigsuspend(td, mask));
 1465 }
 1466 
 1467 int
 1468 kern_sigsuspend(struct thread *td, sigset_t mask)
 1469 {
 1470         struct proc *p = td->td_proc;
 1471         int has_sig, sig;
 1472 
 1473         /*
 1474          * When returning from sigsuspend, we want
 1475          * the old mask to be restored after the
 1476          * signal handler has finished.  Thus, we
 1477          * save it here and mark the sigacts structure
 1478          * to indicate this.
 1479          */
 1480         PROC_LOCK(p);
 1481         kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask,
 1482             SIGPROCMASK_PROC_LOCKED);
 1483         td->td_pflags |= TDP_OLDMASK;
 1484 
 1485         /*
 1486          * Process signals now. Otherwise, we can get spurious wakeup
 1487          * due to signal entered process queue, but delivered to other
 1488          * thread. But sigsuspend should return only on signal
 1489          * delivery.
 1490          */
 1491         (p->p_sysent->sv_set_syscall_retval)(td, EINTR);
 1492         for (has_sig = 0; !has_sig;) {
 1493                 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause",
 1494                         0) == 0)
 1495                         /* void */;
 1496                 thread_suspend_check(0);
 1497                 mtx_lock(&p->p_sigacts->ps_mtx);
 1498                 while ((sig = cursig(td)) != 0)
 1499                         has_sig += postsig(sig);
 1500                 mtx_unlock(&p->p_sigacts->ps_mtx);
 1501         }
 1502         PROC_UNLOCK(p);
 1503         td->td_errno = EINTR;
 1504         td->td_pflags |= TDP_NERRNO;
 1505         return (EJUSTRETURN);
 1506 }
 1507 
 1508 #ifdef COMPAT_43        /* XXX - COMPAT_FBSD3 */
 1509 /*
 1510  * Compatibility sigsuspend call for old binaries.  Note nonstandard calling
 1511  * convention: libc stub passes mask, not pointer, to save a copyin.
 1512  */
 1513 #ifndef _SYS_SYSPROTO_H_
 1514 struct osigsuspend_args {
 1515         osigset_t mask;
 1516 };
 1517 #endif
 1518 /* ARGSUSED */
 1519 int
 1520 osigsuspend(td, uap)
 1521         struct thread *td;
 1522         struct osigsuspend_args *uap;
 1523 {
 1524         sigset_t mask;
 1525 
 1526         OSIG2SIG(uap->mask, mask);
 1527         return (kern_sigsuspend(td, mask));
 1528 }
 1529 #endif /* COMPAT_43 */
 1530 
 1531 #if defined(COMPAT_43)
 1532 #ifndef _SYS_SYSPROTO_H_
 1533 struct osigstack_args {
 1534         struct  sigstack *nss;
 1535         struct  sigstack *oss;
 1536 };
 1537 #endif
 1538 /* ARGSUSED */
 1539 int
 1540 osigstack(td, uap)
 1541         struct thread *td;
 1542         register struct osigstack_args *uap;
 1543 {
 1544         struct sigstack nss, oss;
 1545         int error = 0;
 1546 
 1547         if (uap->nss != NULL) {
 1548                 error = copyin(uap->nss, &nss, sizeof(nss));
 1549                 if (error)
 1550                         return (error);
 1551         }
 1552         oss.ss_sp = td->td_sigstk.ss_sp;
 1553         oss.ss_onstack = sigonstack(cpu_getstack(td));
 1554         if (uap->nss != NULL) {
 1555                 td->td_sigstk.ss_sp = nss.ss_sp;
 1556                 td->td_sigstk.ss_size = 0;
 1557                 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK;
 1558                 td->td_pflags |= TDP_ALTSTACK;
 1559         }
 1560         if (uap->oss != NULL)
 1561                 error = copyout(&oss, uap->oss, sizeof(oss));
 1562 
 1563         return (error);
 1564 }
 1565 #endif /* COMPAT_43 */
 1566 
 1567 #ifndef _SYS_SYSPROTO_H_
 1568 struct sigaltstack_args {
 1569         stack_t *ss;
 1570         stack_t *oss;
 1571 };
 1572 #endif
 1573 /* ARGSUSED */
 1574 int
 1575 sys_sigaltstack(td, uap)
 1576         struct thread *td;
 1577         register struct sigaltstack_args *uap;
 1578 {
 1579         stack_t ss, oss;
 1580         int error;
 1581 
 1582         if (uap->ss != NULL) {
 1583                 error = copyin(uap->ss, &ss, sizeof(ss));
 1584                 if (error)
 1585                         return (error);
 1586         }
 1587         error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL,
 1588             (uap->oss != NULL) ? &oss : NULL);
 1589         if (error)
 1590                 return (error);
 1591         if (uap->oss != NULL)
 1592                 error = copyout(&oss, uap->oss, sizeof(stack_t));
 1593         return (error);
 1594 }
 1595 
 1596 int
 1597 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss)
 1598 {
 1599         struct proc *p = td->td_proc;
 1600         int oonstack;
 1601 
 1602         oonstack = sigonstack(cpu_getstack(td));
 1603 
 1604         if (oss != NULL) {
 1605                 *oss = td->td_sigstk;
 1606                 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK)
 1607                     ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
 1608         }
 1609 
 1610         if (ss != NULL) {
 1611                 if (oonstack)
 1612                         return (EPERM);
 1613                 if ((ss->ss_flags & ~SS_DISABLE) != 0)
 1614                         return (EINVAL);
 1615                 if (!(ss->ss_flags & SS_DISABLE)) {
 1616                         if (ss->ss_size < p->p_sysent->sv_minsigstksz)
 1617                                 return (ENOMEM);
 1618 
 1619                         td->td_sigstk = *ss;
 1620                         td->td_pflags |= TDP_ALTSTACK;
 1621                 } else {
 1622                         td->td_pflags &= ~TDP_ALTSTACK;
 1623                 }
 1624         }
 1625         return (0);
 1626 }
 1627 
 1628 /*
 1629  * Common code for kill process group/broadcast kill.
 1630  * cp is calling process.
 1631  */
 1632 static int
 1633 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi)
 1634 {
 1635         struct proc *p;
 1636         struct pgrp *pgrp;
 1637         int err;
 1638         int ret;
 1639 
 1640         ret = ESRCH;
 1641         if (all) {
 1642                 /*
 1643                  * broadcast
 1644                  */
 1645                 sx_slock(&allproc_lock);
 1646                 FOREACH_PROC_IN_SYSTEM(p) {
 1647                         PROC_LOCK(p);
 1648                         if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
 1649                             p == td->td_proc || p->p_state == PRS_NEW) {
 1650                                 PROC_UNLOCK(p);
 1651                                 continue;
 1652                         }
 1653                         err = p_cansignal(td, p, sig);
 1654                         if (err == 0) {
 1655                                 if (sig)
 1656                                         pksignal(p, sig, ksi);
 1657                                 ret = err;
 1658                         }
 1659                         else if (ret == ESRCH)
 1660                                 ret = err;
 1661                         PROC_UNLOCK(p);
 1662                 }
 1663                 sx_sunlock(&allproc_lock);
 1664         } else {
 1665                 sx_slock(&proctree_lock);
 1666                 if (pgid == 0) {
 1667                         /*
 1668                          * zero pgid means send to my process group.
 1669                          */
 1670                         pgrp = td->td_proc->p_pgrp;
 1671                         PGRP_LOCK(pgrp);
 1672                 } else {
 1673                         pgrp = pgfind(pgid);
 1674                         if (pgrp == NULL) {
 1675                                 sx_sunlock(&proctree_lock);
 1676                                 return (ESRCH);
 1677                         }
 1678                 }
 1679                 sx_sunlock(&proctree_lock);
 1680                 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
 1681                         PROC_LOCK(p);
 1682                         if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
 1683                             p->p_state == PRS_NEW) {
 1684                                 PROC_UNLOCK(p);
 1685                                 continue;
 1686                         }
 1687                         err = p_cansignal(td, p, sig);
 1688                         if (err == 0) {
 1689                                 if (sig)
 1690                                         pksignal(p, sig, ksi);
 1691                                 ret = err;
 1692                         }
 1693                         else if (ret == ESRCH)
 1694                                 ret = err;
 1695                         PROC_UNLOCK(p);
 1696                 }
 1697                 PGRP_UNLOCK(pgrp);
 1698         }
 1699         return (ret);
 1700 }
 1701 
 1702 #ifndef _SYS_SYSPROTO_H_
 1703 struct kill_args {
 1704         int     pid;
 1705         int     signum;
 1706 };
 1707 #endif
 1708 /* ARGSUSED */
 1709 int
 1710 sys_kill(struct thread *td, struct kill_args *uap)
 1711 {
 1712         ksiginfo_t ksi;
 1713         struct proc *p;
 1714         int error;
 1715 
 1716         /*
 1717          * A process in capability mode can send signals only to himself.
 1718          * The main rationale behind this is that abort(3) is implemented as
 1719          * kill(getpid(), SIGABRT).
 1720          */
 1721         if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid)
 1722                 return (ECAPMODE);
 1723 
 1724         AUDIT_ARG_SIGNUM(uap->signum);
 1725         AUDIT_ARG_PID(uap->pid);
 1726         if ((u_int)uap->signum > _SIG_MAXSIG)
 1727                 return (EINVAL);
 1728 
 1729         ksiginfo_init(&ksi);
 1730         ksi.ksi_signo = uap->signum;
 1731         ksi.ksi_code = SI_USER;
 1732         ksi.ksi_pid = td->td_proc->p_pid;
 1733         ksi.ksi_uid = td->td_ucred->cr_ruid;
 1734 
 1735         if (uap->pid > 0) {
 1736                 /* kill single process */
 1737                 if ((p = pfind(uap->pid)) == NULL) {
 1738                         if ((p = zpfind(uap->pid)) == NULL)
 1739                                 return (ESRCH);
 1740                 }
 1741                 AUDIT_ARG_PROCESS(p);
 1742                 error = p_cansignal(td, p, uap->signum);
 1743                 if (error == 0 && uap->signum)
 1744                         pksignal(p, uap->signum, &ksi);
 1745                 PROC_UNLOCK(p);
 1746                 return (error);
 1747         }
 1748         switch (uap->pid) {
 1749         case -1:                /* broadcast signal */
 1750                 return (killpg1(td, uap->signum, 0, 1, &ksi));
 1751         case 0:                 /* signal own process group */
 1752                 return (killpg1(td, uap->signum, 0, 0, &ksi));
 1753         default:                /* negative explicit process group */
 1754                 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi));
 1755         }
 1756         /* NOTREACHED */
 1757 }
 1758 
 1759 int
 1760 sys_pdkill(td, uap)
 1761         struct thread *td;
 1762         struct pdkill_args *uap;
 1763 {
 1764 #ifdef PROCDESC
 1765         struct proc *p;
 1766         cap_rights_t rights;
 1767         int error;
 1768 
 1769         AUDIT_ARG_SIGNUM(uap->signum);
 1770         AUDIT_ARG_FD(uap->fd);
 1771         if ((u_int)uap->signum > _SIG_MAXSIG)
 1772                 return (EINVAL);
 1773 
 1774         error = procdesc_find(td, uap->fd,
 1775             cap_rights_init(&rights, CAP_PDKILL), &p);
 1776         if (error)
 1777                 return (error);
 1778         AUDIT_ARG_PROCESS(p);
 1779         error = p_cansignal(td, p, uap->signum);
 1780         if (error == 0 && uap->signum)
 1781                 kern_psignal(p, uap->signum);
 1782         PROC_UNLOCK(p);
 1783         return (error);
 1784 #else
 1785         return (ENOSYS);
 1786 #endif
 1787 }
 1788 
 1789 #if defined(COMPAT_43)
 1790 #ifndef _SYS_SYSPROTO_H_
 1791 struct okillpg_args {
 1792         int     pgid;
 1793         int     signum;
 1794 };
 1795 #endif
 1796 /* ARGSUSED */
 1797 int
 1798 okillpg(struct thread *td, struct okillpg_args *uap)
 1799 {
 1800         ksiginfo_t ksi;
 1801 
 1802         AUDIT_ARG_SIGNUM(uap->signum);
 1803         AUDIT_ARG_PID(uap->pgid);
 1804         if ((u_int)uap->signum > _SIG_MAXSIG)
 1805                 return (EINVAL);
 1806 
 1807         ksiginfo_init(&ksi);
 1808         ksi.ksi_signo = uap->signum;
 1809         ksi.ksi_code = SI_USER;
 1810         ksi.ksi_pid = td->td_proc->p_pid;
 1811         ksi.ksi_uid = td->td_ucred->cr_ruid;
 1812         return (killpg1(td, uap->signum, uap->pgid, 0, &ksi));
 1813 }
 1814 #endif /* COMPAT_43 */
 1815 
 1816 #ifndef _SYS_SYSPROTO_H_
 1817 struct sigqueue_args {
 1818         pid_t pid;
 1819         int signum;
 1820         /* union sigval */ void *value;
 1821 };
 1822 #endif
 1823 int
 1824 sys_sigqueue(struct thread *td, struct sigqueue_args *uap)
 1825 {
 1826         ksiginfo_t ksi;
 1827         struct proc *p;
 1828         int error;
 1829 
 1830         if ((u_int)uap->signum > _SIG_MAXSIG)
 1831                 return (EINVAL);
 1832 
 1833         /*
 1834          * Specification says sigqueue can only send signal to
 1835          * single process.
 1836          */
 1837         if (uap->pid <= 0)
 1838                 return (EINVAL);
 1839 
 1840         if ((p = pfind(uap->pid)) == NULL) {
 1841                 if ((p = zpfind(uap->pid)) == NULL)
 1842                         return (ESRCH);
 1843         }
 1844         error = p_cansignal(td, p, uap->signum);
 1845         if (error == 0 && uap->signum != 0) {
 1846                 ksiginfo_init(&ksi);
 1847                 ksi.ksi_flags = KSI_SIGQ;
 1848                 ksi.ksi_signo = uap->signum;
 1849                 ksi.ksi_code = SI_QUEUE;
 1850                 ksi.ksi_pid = td->td_proc->p_pid;
 1851                 ksi.ksi_uid = td->td_ucred->cr_ruid;
 1852                 ksi.ksi_value.sival_ptr = uap->value;
 1853                 error = pksignal(p, ksi.ksi_signo, &ksi);
 1854         }
 1855         PROC_UNLOCK(p);
 1856         return (error);
 1857 }
 1858 
 1859 /*
 1860  * Send a signal to a process group.
 1861  */
 1862 void
 1863 gsignal(int pgid, int sig, ksiginfo_t *ksi)
 1864 {
 1865         struct pgrp *pgrp;
 1866 
 1867         if (pgid != 0) {
 1868                 sx_slock(&proctree_lock);
 1869                 pgrp = pgfind(pgid);
 1870                 sx_sunlock(&proctree_lock);
 1871                 if (pgrp != NULL) {
 1872                         pgsignal(pgrp, sig, 0, ksi);
 1873                         PGRP_UNLOCK(pgrp);
 1874                 }
 1875         }
 1876 }
 1877 
 1878 /*
 1879  * Send a signal to a process group.  If checktty is 1,
 1880  * limit to members which have a controlling terminal.
 1881  */
 1882 void
 1883 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi)
 1884 {
 1885         struct proc *p;
 1886 
 1887         if (pgrp) {
 1888                 PGRP_LOCK_ASSERT(pgrp, MA_OWNED);
 1889                 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
 1890                         PROC_LOCK(p);
 1891                         if (p->p_state == PRS_NORMAL &&
 1892                             (checkctty == 0 || p->p_flag & P_CONTROLT))
 1893                                 pksignal(p, sig, ksi);
 1894                         PROC_UNLOCK(p);
 1895                 }
 1896         }
 1897 }
 1898 
 1899 
 1900 /*
 1901  * Recalculate the signal mask and reset the signal disposition after
 1902  * usermode frame for delivery is formed.  Should be called after
 1903  * mach-specific routine, because sysent->sv_sendsig() needs correct
 1904  * ps_siginfo and signal mask.
 1905  */
 1906 static void
 1907 postsig_done(int sig, struct thread *td, struct sigacts *ps)
 1908 {
 1909         sigset_t mask;
 1910 
 1911         mtx_assert(&ps->ps_mtx, MA_OWNED);
 1912         td->td_ru.ru_nsignals++;
 1913         mask = ps->ps_catchmask[_SIG_IDX(sig)];
 1914         if (!SIGISMEMBER(ps->ps_signodefer, sig))
 1915                 SIGADDSET(mask, sig);
 1916         kern_sigprocmask(td, SIG_BLOCK, &mask, NULL,
 1917             SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED);
 1918         if (SIGISMEMBER(ps->ps_sigreset, sig))
 1919                 sigdflt(ps, sig);
 1920 }
 1921 
 1922 
 1923 /*
 1924  * Send a signal caused by a trap to the current thread.  If it will be
 1925  * caught immediately, deliver it with correct code.  Otherwise, post it
 1926  * normally.
 1927  */
 1928 void
 1929 trapsignal(struct thread *td, ksiginfo_t *ksi)
 1930 {
 1931         struct sigacts *ps;
 1932         struct proc *p;
 1933         int sig;
 1934         int code;
 1935 
 1936         p = td->td_proc;
 1937         sig = ksi->ksi_signo;
 1938         code = ksi->ksi_code;
 1939         KASSERT(_SIG_VALID(sig), ("invalid signal"));
 1940 
 1941         PROC_LOCK(p);
 1942         ps = p->p_sigacts;
 1943         mtx_lock(&ps->ps_mtx);
 1944         if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) &&
 1945             !SIGISMEMBER(td->td_sigmask, sig)) {
 1946 #ifdef KTRACE
 1947                 if (KTRPOINT(curthread, KTR_PSIG))
 1948                         ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)],
 1949                             &td->td_sigmask, code);
 1950 #endif
 1951                 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)],
 1952                                 ksi, &td->td_sigmask);
 1953                 postsig_done(sig, td, ps);
 1954                 mtx_unlock(&ps->ps_mtx);
 1955         } else {
 1956                 /*
 1957                  * Avoid a possible infinite loop if the thread
 1958                  * masking the signal or process is ignoring the
 1959                  * signal.
 1960                  */
 1961                 if (kern_forcesigexit &&
 1962                     (SIGISMEMBER(td->td_sigmask, sig) ||
 1963                      ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) {
 1964                         SIGDELSET(td->td_sigmask, sig);
 1965                         SIGDELSET(ps->ps_sigcatch, sig);
 1966                         SIGDELSET(ps->ps_sigignore, sig);
 1967                         ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
 1968                 }
 1969                 mtx_unlock(&ps->ps_mtx);
 1970                 p->p_code = code;       /* XXX for core dump/debugger */
 1971                 p->p_sig = sig;         /* XXX to verify code */
 1972                 tdsendsignal(p, td, sig, ksi);
 1973         }
 1974         PROC_UNLOCK(p);
 1975 }
 1976 
 1977 static struct thread *
 1978 sigtd(struct proc *p, int sig, int prop)
 1979 {
 1980         struct thread *td, *signal_td;
 1981 
 1982         PROC_LOCK_ASSERT(p, MA_OWNED);
 1983 
 1984         /*
 1985          * Check if current thread can handle the signal without
 1986          * switching context to another thread.
 1987          */
 1988         if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig))
 1989                 return (curthread);
 1990         signal_td = NULL;
 1991         FOREACH_THREAD_IN_PROC(p, td) {
 1992                 if (!SIGISMEMBER(td->td_sigmask, sig)) {
 1993                         signal_td = td;
 1994                         break;
 1995                 }
 1996         }
 1997         if (signal_td == NULL)
 1998                 signal_td = FIRST_THREAD_IN_PROC(p);
 1999         return (signal_td);
 2000 }
 2001 
 2002 /*
 2003  * Send the signal to the process.  If the signal has an action, the action
 2004  * is usually performed by the target process rather than the caller; we add
 2005  * the signal to the set of pending signals for the process.
 2006  *
 2007  * Exceptions:
 2008  *   o When a stop signal is sent to a sleeping process that takes the
 2009  *     default action, the process is stopped without awakening it.
 2010  *   o SIGCONT restarts stopped processes (or puts them back to sleep)
 2011  *     regardless of the signal action (eg, blocked or ignored).
 2012  *
 2013  * Other ignored signals are discarded immediately.
 2014  *
 2015  * NB: This function may be entered from the debugger via the "kill" DDB
 2016  * command.  There is little that can be done to mitigate the possibly messy
 2017  * side effects of this unwise possibility.
 2018  */
 2019 void
 2020 kern_psignal(struct proc *p, int sig)
 2021 {
 2022         ksiginfo_t ksi;
 2023 
 2024         ksiginfo_init(&ksi);
 2025         ksi.ksi_signo = sig;
 2026         ksi.ksi_code = SI_KERNEL;
 2027         (void) tdsendsignal(p, NULL, sig, &ksi);
 2028 }
 2029 
 2030 int
 2031 pksignal(struct proc *p, int sig, ksiginfo_t *ksi)
 2032 {
 2033 
 2034         return (tdsendsignal(p, NULL, sig, ksi));
 2035 }
 2036 
 2037 /* Utility function for finding a thread to send signal event to. */
 2038 int
 2039 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd)
 2040 {
 2041         struct thread *td;
 2042 
 2043         if (sigev->sigev_notify == SIGEV_THREAD_ID) {
 2044                 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid);
 2045                 if (td == NULL)
 2046                         return (ESRCH);
 2047                 *ttd = td;
 2048         } else {
 2049                 *ttd = NULL;
 2050                 PROC_LOCK(p);
 2051         }
 2052         return (0);
 2053 }
 2054 
 2055 void
 2056 tdsignal(struct thread *td, int sig)
 2057 {
 2058         ksiginfo_t ksi;
 2059 
 2060         ksiginfo_init(&ksi);
 2061         ksi.ksi_signo = sig;
 2062         ksi.ksi_code = SI_KERNEL;
 2063         (void) tdsendsignal(td->td_proc, td, sig, &ksi);
 2064 }
 2065 
 2066 void
 2067 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi)
 2068 {
 2069 
 2070         (void) tdsendsignal(td->td_proc, td, sig, ksi);
 2071 }
 2072 
 2073 int
 2074 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi)
 2075 {
 2076         sig_t action;
 2077         sigqueue_t *sigqueue;
 2078         int prop;
 2079         struct sigacts *ps;
 2080         int intrval;
 2081         int ret = 0;
 2082         int wakeup_swapper;
 2083 
 2084         MPASS(td == NULL || p == td->td_proc);
 2085         PROC_LOCK_ASSERT(p, MA_OWNED);
 2086 
 2087         if (!_SIG_VALID(sig))
 2088                 panic("%s(): invalid signal %d", __func__, sig);
 2089 
 2090         KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__));
 2091 
 2092         /*
 2093          * IEEE Std 1003.1-2001: return success when killing a zombie.
 2094          */
 2095         if (p->p_state == PRS_ZOMBIE) {
 2096                 if (ksi && (ksi->ksi_flags & KSI_INS))
 2097                         ksiginfo_tryfree(ksi);
 2098                 return (ret);
 2099         }
 2100 
 2101         ps = p->p_sigacts;
 2102         KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig);
 2103         prop = sigprop(sig);
 2104 
 2105         if (td == NULL) {
 2106                 td = sigtd(p, sig, prop);
 2107                 sigqueue = &p->p_sigqueue;
 2108         } else
 2109                 sigqueue = &td->td_sigqueue;
 2110 
 2111         SDT_PROBE3(proc, kernel, , signal__send, td, p, sig);
 2112 
 2113         /*
 2114          * If the signal is being ignored,
 2115          * then we forget about it immediately.
 2116          * (Note: we don't set SIGCONT in ps_sigignore,
 2117          * and if it is set to SIG_IGN,
 2118          * action will be SIG_DFL here.)
 2119          */
 2120         mtx_lock(&ps->ps_mtx);
 2121         if (SIGISMEMBER(ps->ps_sigignore, sig)) {
 2122                 SDT_PROBE3(proc, kernel, , signal__discard, td, p, sig);
 2123 
 2124                 mtx_unlock(&ps->ps_mtx);
 2125                 if (ksi && (ksi->ksi_flags & KSI_INS))
 2126                         ksiginfo_tryfree(ksi);
 2127                 return (ret);
 2128         }
 2129         if (SIGISMEMBER(td->td_sigmask, sig))
 2130                 action = SIG_HOLD;
 2131         else if (SIGISMEMBER(ps->ps_sigcatch, sig))
 2132                 action = SIG_CATCH;
 2133         else
 2134                 action = SIG_DFL;
 2135         if (SIGISMEMBER(ps->ps_sigintr, sig))
 2136                 intrval = EINTR;
 2137         else
 2138                 intrval = ERESTART;
 2139         mtx_unlock(&ps->ps_mtx);
 2140 
 2141         if (prop & SA_CONT)
 2142                 sigqueue_delete_stopmask_proc(p);
 2143         else if (prop & SA_STOP) {
 2144                 /*
 2145                  * If sending a tty stop signal to a member of an orphaned
 2146                  * process group, discard the signal here if the action
 2147                  * is default; don't stop the process below if sleeping,
 2148                  * and don't clear any pending SIGCONT.
 2149                  */
 2150                 if ((prop & SA_TTYSTOP) &&
 2151                     (p->p_pgrp->pg_jobc == 0) &&
 2152                     (action == SIG_DFL)) {
 2153                         if (ksi && (ksi->ksi_flags & KSI_INS))
 2154                                 ksiginfo_tryfree(ksi);
 2155                         return (ret);
 2156                 }
 2157                 sigqueue_delete_proc(p, SIGCONT);
 2158                 if (p->p_flag & P_CONTINUED) {
 2159                         p->p_flag &= ~P_CONTINUED;
 2160                         PROC_LOCK(p->p_pptr);
 2161                         sigqueue_take(p->p_ksi);
 2162                         PROC_UNLOCK(p->p_pptr);
 2163                 }
 2164         }
 2165 
 2166         ret = sigqueue_add(sigqueue, sig, ksi);
 2167         if (ret != 0)
 2168                 return (ret);
 2169         signotify(td);
 2170         /*
 2171          * Defer further processing for signals which are held,
 2172          * except that stopped processes must be continued by SIGCONT.
 2173          */
 2174         if (action == SIG_HOLD &&
 2175             !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG)))
 2176                 return (ret);
 2177         /*
 2178          * SIGKILL: Remove procfs STOPEVENTs.
 2179          */
 2180         if (sig == SIGKILL) {
 2181                 /* from procfs_ioctl.c: PIOCBIC */
 2182                 p->p_stops = 0;
 2183                 /* from procfs_ioctl.c: PIOCCONT */
 2184                 p->p_step = 0;
 2185                 wakeup(&p->p_step);
 2186         }
 2187         /*
 2188          * Some signals have a process-wide effect and a per-thread
 2189          * component.  Most processing occurs when the process next
 2190          * tries to cross the user boundary, however there are some
 2191          * times when processing needs to be done immediately, such as
 2192          * waking up threads so that they can cross the user boundary.
 2193          * We try to do the per-process part here.
 2194          */
 2195         if (P_SHOULDSTOP(p)) {
 2196                 KASSERT(!(p->p_flag & P_WEXIT),
 2197                     ("signal to stopped but exiting process"));
 2198                 if (sig == SIGKILL) {
 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                          * SIGKILL sets process running.
 2207                          * It will die elsewhere.
 2208                          * All threads must be restarted.
 2209                          */
 2210                         p->p_flag &= ~P_STOPPED_SIG;
 2211                         goto runfast;
 2212                 }
 2213 
 2214                 if (prop & SA_CONT) {
 2215                         /*
 2216                          * If traced process is already stopped,
 2217                          * then no further action is necessary.
 2218                          */
 2219                         if (p->p_flag & P_TRACED)
 2220                                 goto out;
 2221                         /*
 2222                          * If SIGCONT is default (or ignored), we continue the
 2223                          * process but don't leave the signal in sigqueue as
 2224                          * it has no further action.  If SIGCONT is held, we
 2225                          * continue the process and leave the signal in
 2226                          * sigqueue.  If the process catches SIGCONT, let it
 2227                          * handle the signal itself.  If it isn't waiting on
 2228                          * an event, it goes back to run state.
 2229                          * Otherwise, process goes back to sleep state.
 2230                          */
 2231                         p->p_flag &= ~P_STOPPED_SIG;
 2232                         PROC_SLOCK(p);
 2233                         if (p->p_numthreads == p->p_suspcount) {
 2234                                 PROC_SUNLOCK(p);
 2235                                 p->p_flag |= P_CONTINUED;
 2236                                 p->p_xstat = SIGCONT;
 2237                                 PROC_LOCK(p->p_pptr);
 2238                                 childproc_continued(p);
 2239                                 PROC_UNLOCK(p->p_pptr);
 2240                                 PROC_SLOCK(p);
 2241                         }
 2242                         if (action == SIG_DFL) {
 2243                                 thread_unsuspend(p);
 2244                                 PROC_SUNLOCK(p);
 2245                                 sigqueue_delete(sigqueue, sig);
 2246                                 goto out;
 2247                         }
 2248                         if (action == SIG_CATCH) {
 2249                                 /*
 2250                                  * The process wants to catch it so it needs
 2251                                  * to run at least one thread, but which one?
 2252                                  */
 2253                                 PROC_SUNLOCK(p);
 2254                                 goto runfast;
 2255                         }
 2256                         /*
 2257                          * The signal is not ignored or caught.
 2258                          */
 2259                         thread_unsuspend(p);
 2260                         PROC_SUNLOCK(p);
 2261                         goto out;
 2262                 }
 2263 
 2264                 if (prop & SA_STOP) {
 2265                         /*
 2266                          * If traced process is already stopped,
 2267                          * then no further action is necessary.
 2268                          */
 2269                         if (p->p_flag & P_TRACED)
 2270                                 goto out;
 2271                         /*
 2272                          * Already stopped, don't need to stop again
 2273                          * (If we did the shell could get confused).
 2274                          * Just make sure the signal STOP bit set.
 2275                          */
 2276                         p->p_flag |= P_STOPPED_SIG;
 2277                         sigqueue_delete(sigqueue, sig);
 2278                         goto out;
 2279                 }
 2280 
 2281                 /*
 2282                  * All other kinds of signals:
 2283                  * If a thread is sleeping interruptibly, simulate a
 2284                  * wakeup so that when it is continued it will be made
 2285                  * runnable and can look at the signal.  However, don't make
 2286                  * the PROCESS runnable, leave it stopped.
 2287                  * It may run a bit until it hits a thread_suspend_check().
 2288                  */
 2289                 wakeup_swapper = 0;
 2290                 PROC_SLOCK(p);
 2291                 thread_lock(td);
 2292                 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR))
 2293                         wakeup_swapper = sleepq_abort(td, intrval);
 2294                 thread_unlock(td);
 2295                 PROC_SUNLOCK(p);
 2296                 if (wakeup_swapper)
 2297                         kick_proc0();
 2298                 goto out;
 2299                 /*
 2300                  * Mutexes are short lived. Threads waiting on them will
 2301                  * hit thread_suspend_check() soon.
 2302                  */
 2303         } else if (p->p_state == PRS_NORMAL) {
 2304                 if (p->p_flag & P_TRACED || action == SIG_CATCH) {
 2305                         tdsigwakeup(td, sig, action, intrval);
 2306                         goto out;
 2307                 }
 2308 
 2309                 MPASS(action == SIG_DFL);
 2310 
 2311                 if (prop & SA_STOP) {
 2312                         if (p->p_flag & (P_PPWAIT|P_WEXIT))
 2313                                 goto out;
 2314                         p->p_flag |= P_STOPPED_SIG;
 2315                         p->p_xstat = sig;
 2316                         PROC_SLOCK(p);
 2317                         sig_suspend_threads(td, p, 1);
 2318                         if (p->p_numthreads == p->p_suspcount) {
 2319                                 /*
 2320                                  * only thread sending signal to another
 2321                                  * process can reach here, if thread is sending
 2322                                  * signal to its process, because thread does
 2323                                  * not suspend itself here, p_numthreads
 2324                                  * should never be equal to p_suspcount.
 2325                                  */
 2326                                 thread_stopped(p);
 2327                                 PROC_SUNLOCK(p);
 2328                                 sigqueue_delete_proc(p, p->p_xstat);
 2329                         } else
 2330                                 PROC_SUNLOCK(p);
 2331                         goto out;
 2332                 }
 2333         } else {
 2334                 /* Not in "NORMAL" state. discard the signal. */
 2335                 sigqueue_delete(sigqueue, sig);
 2336                 goto out;
 2337         }
 2338 
 2339         /*
 2340          * The process is not stopped so we need to apply the signal to all the
 2341          * running threads.
 2342          */
 2343 runfast:
 2344         tdsigwakeup(td, sig, action, intrval);
 2345         PROC_SLOCK(p);
 2346         thread_unsuspend(p);
 2347         PROC_SUNLOCK(p);
 2348 out:
 2349         /* If we jump here, proc slock should not be owned. */
 2350         PROC_SLOCK_ASSERT(p, MA_NOTOWNED);
 2351         return (ret);
 2352 }
 2353 
 2354 /*
 2355  * The force of a signal has been directed against a single
 2356  * thread.  We need to see what we can do about knocking it
 2357  * out of any sleep it may be in etc.
 2358  */
 2359 static void
 2360 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval)
 2361 {
 2362         struct proc *p = td->td_proc;
 2363         register int prop;
 2364         int wakeup_swapper;
 2365 
 2366         wakeup_swapper = 0;
 2367         PROC_LOCK_ASSERT(p, MA_OWNED);
 2368         prop = sigprop(sig);
 2369 
 2370         PROC_SLOCK(p);
 2371         thread_lock(td);
 2372         /*
 2373          * Bring the priority of a thread up if we want it to get
 2374          * killed in this lifetime.  Be careful to avoid bumping the
 2375          * priority of the idle thread, since we still allow to signal
 2376          * kernel processes.
 2377          */
 2378         if (action == SIG_DFL && (prop & SA_KILL) != 0 &&
 2379             td->td_priority > PUSER && !TD_IS_IDLETHREAD(td))
 2380                 sched_prio(td, PUSER);
 2381         if (TD_ON_SLEEPQ(td)) {
 2382                 /*
 2383                  * If thread is sleeping uninterruptibly
 2384                  * we can't interrupt the sleep... the signal will
 2385                  * be noticed when the process returns through
 2386                  * trap() or syscall().
 2387                  */
 2388                 if ((td->td_flags & TDF_SINTR) == 0)
 2389                         goto out;
 2390                 /*
 2391                  * If SIGCONT is default (or ignored) and process is
 2392                  * asleep, we are finished; the process should not
 2393                  * be awakened.
 2394                  */
 2395                 if ((prop & SA_CONT) && action == SIG_DFL) {
 2396                         thread_unlock(td);
 2397                         PROC_SUNLOCK(p);
 2398                         sigqueue_delete(&p->p_sigqueue, sig);
 2399                         /*
 2400                          * It may be on either list in this state.
 2401                          * Remove from both for now.
 2402                          */
 2403                         sigqueue_delete(&td->td_sigqueue, sig);
 2404                         return;
 2405                 }
 2406 
 2407                 /*
 2408                  * Don't awaken a sleeping thread for SIGSTOP if the
 2409                  * STOP signal is deferred.
 2410                  */
 2411                 if ((prop & SA_STOP) && (td->td_flags & TDF_SBDRY))
 2412                         goto out;
 2413 
 2414                 /*
 2415                  * Give low priority threads a better chance to run.
 2416                  */
 2417                 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td))
 2418                         sched_prio(td, PUSER);
 2419 
 2420                 wakeup_swapper = sleepq_abort(td, intrval);
 2421         } else {
 2422                 /*
 2423                  * Other states do nothing with the signal immediately,
 2424                  * other than kicking ourselves if we are running.
 2425                  * It will either never be noticed, or noticed very soon.
 2426                  */
 2427 #ifdef SMP
 2428                 if (TD_IS_RUNNING(td) && td != curthread)
 2429                         forward_signal(td);
 2430 #endif
 2431         }
 2432 out:
 2433         PROC_SUNLOCK(p);
 2434         thread_unlock(td);
 2435         if (wakeup_swapper)
 2436                 kick_proc0();
 2437 }
 2438 
 2439 static void
 2440 sig_suspend_threads(struct thread *td, struct proc *p, int sending)
 2441 {
 2442         struct thread *td2;
 2443 
 2444         PROC_LOCK_ASSERT(p, MA_OWNED);
 2445         PROC_SLOCK_ASSERT(p, MA_OWNED);
 2446 
 2447         FOREACH_THREAD_IN_PROC(p, td2) {
 2448                 thread_lock(td2);
 2449                 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK;
 2450                 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) &&
 2451                     (td2->td_flags & TDF_SINTR)) {
 2452                         if (td2->td_flags & TDF_SBDRY) {
 2453                                 /*
 2454                                  * Once a thread is asleep with
 2455                                  * TDF_SBDRY set, it should never
 2456                                  * become suspended due to this check.
 2457                                  */
 2458                                 KASSERT(!TD_IS_SUSPENDED(td2),
 2459                                     ("thread with deferred stops suspended"));
 2460                         } else if (!TD_IS_SUSPENDED(td2)) {
 2461                                 thread_suspend_one(td2);
 2462                         }
 2463                 } else if (!TD_IS_SUSPENDED(td2)) {
 2464                         if (sending || td != td2)
 2465                                 td2->td_flags |= TDF_ASTPENDING;
 2466 #ifdef SMP
 2467                         if (TD_IS_RUNNING(td2) && td2 != td)
 2468                                 forward_signal(td2);
 2469 #endif
 2470                 }
 2471                 thread_unlock(td2);
 2472         }
 2473 }
 2474 
 2475 int
 2476 ptracestop(struct thread *td, int sig)
 2477 {
 2478         struct proc *p = td->td_proc;
 2479 
 2480         PROC_LOCK_ASSERT(p, MA_OWNED);
 2481         KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process"));
 2482         WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
 2483             &p->p_mtx.lock_object, "Stopping for traced signal");
 2484 
 2485         td->td_dbgflags |= TDB_XSIG;
 2486         td->td_xsig = sig;
 2487         CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d",
 2488             td->td_tid, p->p_pid, td->td_dbgflags, sig);
 2489         PROC_SLOCK(p);
 2490         while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) {
 2491                 if (p->p_flag & P_SINGLE_EXIT) {
 2492                         td->td_dbgflags &= ~TDB_XSIG;
 2493                         PROC_SUNLOCK(p);
 2494                         return (sig);
 2495                 }
 2496                 /*
 2497                  * Just make wait() to work, the last stopped thread
 2498                  * will win.
 2499                  */
 2500                 p->p_xstat = sig;
 2501                 p->p_xthread = td;
 2502                 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE);
 2503                 sig_suspend_threads(td, p, 0);
 2504                 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) {
 2505                         td->td_dbgflags &= ~TDB_STOPATFORK;
 2506                         cv_broadcast(&p->p_dbgwait);
 2507                 }
 2508 stopme:
 2509                 thread_suspend_switch(td, p);
 2510                 if (p->p_xthread == td)
 2511                         p->p_xthread = NULL;
 2512                 if (!(p->p_flag & P_TRACED))
 2513                         break;
 2514                 if (td->td_dbgflags & TDB_SUSPEND) {
 2515                         if (p->p_flag & P_SINGLE_EXIT)
 2516                                 break;
 2517                         goto stopme;
 2518                 }
 2519         }
 2520         PROC_SUNLOCK(p);
 2521         return (td->td_xsig);
 2522 }
 2523 
 2524 static void
 2525 reschedule_signals(struct proc *p, sigset_t block, int flags)
 2526 {
 2527         struct sigacts *ps;
 2528         struct thread *td;
 2529         int sig;
 2530 
 2531         PROC_LOCK_ASSERT(p, MA_OWNED);
 2532         ps = p->p_sigacts;
 2533         mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ?
 2534             MA_OWNED : MA_NOTOWNED);
 2535         if (SIGISEMPTY(p->p_siglist))
 2536                 return;
 2537         SIGSETAND(block, p->p_siglist);
 2538         while ((sig = sig_ffs(&block)) != 0) {
 2539                 SIGDELSET(block, sig);
 2540                 td = sigtd(p, sig, 0);
 2541                 signotify(td);
 2542                 if (!(flags & SIGPROCMASK_PS_LOCKED))
 2543                         mtx_lock(&ps->ps_mtx);
 2544                 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig))
 2545                         tdsigwakeup(td, sig, SIG_CATCH,
 2546                             (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR :
 2547                              ERESTART));
 2548                 if (!(flags & SIGPROCMASK_PS_LOCKED))
 2549                         mtx_unlock(&ps->ps_mtx);
 2550         }
 2551 }
 2552 
 2553 void
 2554 tdsigcleanup(struct thread *td)
 2555 {
 2556         struct proc *p;
 2557         sigset_t unblocked;
 2558 
 2559         p = td->td_proc;
 2560         PROC_LOCK_ASSERT(p, MA_OWNED);
 2561 
 2562         sigqueue_flush(&td->td_sigqueue);
 2563         if (p->p_numthreads == 1)
 2564                 return;
 2565 
 2566         /*
 2567          * Since we cannot handle signals, notify signal post code
 2568          * about this by filling the sigmask.
 2569          *
 2570          * Also, if needed, wake up thread(s) that do not block the
 2571          * same signals as the exiting thread, since the thread might
 2572          * have been selected for delivery and woken up.
 2573          */
 2574         SIGFILLSET(unblocked);
 2575         SIGSETNAND(unblocked, td->td_sigmask);
 2576         SIGFILLSET(td->td_sigmask);
 2577         reschedule_signals(p, unblocked, 0);
 2578 
 2579 }
 2580 
 2581 /*
 2582  * Defer the delivery of SIGSTOP for the current thread.  Returns true
 2583  * if stops were deferred and false if they were already deferred.
 2584  */
 2585 int
 2586 sigdeferstop(void)
 2587 {
 2588         struct thread *td;
 2589 
 2590         td = curthread;
 2591         if (td->td_flags & TDF_SBDRY)
 2592                 return (0);
 2593         thread_lock(td);
 2594         td->td_flags |= TDF_SBDRY;
 2595         thread_unlock(td);
 2596         return (1);
 2597 }
 2598 
 2599 /*
 2600  * Permit the delivery of SIGSTOP for the current thread.  This does
 2601  * not immediately suspend if a stop was posted.  Instead, the thread
 2602  * will suspend either via ast() or a subsequent interruptible sleep.
 2603  */
 2604 int
 2605 sigallowstop(void)
 2606 {
 2607         struct thread *td;
 2608         int prev;
 2609 
 2610         td = curthread;
 2611         thread_lock(td);
 2612         prev = (td->td_flags & TDF_SBDRY) != 0;
 2613         td->td_flags &= ~TDF_SBDRY;
 2614         thread_unlock(td);
 2615         return (prev);
 2616 }
 2617 
 2618 /*
 2619  * If the current process has received a signal (should be caught or cause
 2620  * termination, should interrupt current syscall), return the signal number.
 2621  * Stop signals with default action are processed immediately, then cleared;
 2622  * they aren't returned.  This is checked after each entry to the system for
 2623  * a syscall or trap (though this can usually be done without calling issignal
 2624  * by checking the pending signal masks in cursig.) The normal call
 2625  * sequence is
 2626  *
 2627  *      while (sig = cursig(curthread))
 2628  *              postsig(sig);
 2629  */
 2630 static int
 2631 issignal(struct thread *td)
 2632 {
 2633         struct proc *p;
 2634         struct sigacts *ps;
 2635         struct sigqueue *queue;
 2636         sigset_t sigpending;
 2637         int sig, prop, newsig;
 2638 
 2639         p = td->td_proc;
 2640         ps = p->p_sigacts;
 2641         mtx_assert(&ps->ps_mtx, MA_OWNED);
 2642         PROC_LOCK_ASSERT(p, MA_OWNED);
 2643         for (;;) {
 2644                 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
 2645 
 2646                 sigpending = td->td_sigqueue.sq_signals;
 2647                 SIGSETOR(sigpending, p->p_sigqueue.sq_signals);
 2648                 SIGSETNAND(sigpending, td->td_sigmask);
 2649 
 2650                 if (p->p_flag & P_PPWAIT || td->td_flags & TDF_SBDRY)
 2651                         SIG_STOPSIGMASK(sigpending);
 2652                 if (SIGISEMPTY(sigpending))     /* no signal to send */
 2653                         return (0);
 2654                 sig = sig_ffs(&sigpending);
 2655 
 2656                 if (p->p_stops & S_SIG) {
 2657                         mtx_unlock(&ps->ps_mtx);
 2658                         stopevent(p, S_SIG, sig);
 2659                         mtx_lock(&ps->ps_mtx);
 2660                 }
 2661 
 2662                 /*
 2663                  * We should see pending but ignored signals
 2664                  * only if P_TRACED was on when they were posted.
 2665                  */
 2666                 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) {
 2667                         sigqueue_delete(&td->td_sigqueue, sig);
 2668                         sigqueue_delete(&p->p_sigqueue, sig);
 2669                         continue;
 2670                 }
 2671                 if (p->p_flag & P_TRACED && (p->p_flag & P_PPTRACE) == 0) {
 2672                         /*
 2673                          * If traced, always stop.
 2674                          * Remove old signal from queue before the stop.
 2675                          * XXX shrug off debugger, it causes siginfo to
 2676                          * be thrown away.
 2677                          */
 2678                         queue = &td->td_sigqueue;
 2679                         td->td_dbgksi.ksi_signo = 0;
 2680                         if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) {
 2681                                 queue = &p->p_sigqueue;
 2682                                 sigqueue_get(queue, sig, &td->td_dbgksi);
 2683                         }
 2684 
 2685                         mtx_unlock(&ps->ps_mtx);
 2686                         newsig = ptracestop(td, sig);
 2687                         mtx_lock(&ps->ps_mtx);
 2688 
 2689                         if (sig != newsig) {
 2690 
 2691                                 /*
 2692                                  * If parent wants us to take the signal,
 2693                                  * then it will leave it in p->p_xstat;
 2694                                  * otherwise we just look for signals again.
 2695                                 */
 2696                                 if (newsig == 0)
 2697                                         continue;
 2698                                 sig = newsig;
 2699 
 2700                                 /*
 2701                                  * Put the new signal into td_sigqueue. If the
 2702                                  * signal is being masked, look for other
 2703                                  * signals.
 2704                                  */
 2705                                 sigqueue_add(queue, sig, NULL);
 2706                                 if (SIGISMEMBER(td->td_sigmask, sig))
 2707                                         continue;
 2708                                 signotify(td);
 2709                         } else {
 2710                                 if (td->td_dbgksi.ksi_signo != 0) {
 2711                                         td->td_dbgksi.ksi_flags |= KSI_HEAD;
 2712                                         if (sigqueue_add(&td->td_sigqueue, sig,
 2713                                             &td->td_dbgksi) != 0)
 2714                                                 td->td_dbgksi.ksi_signo = 0;
 2715                                 }
 2716                                 if (td->td_dbgksi.ksi_signo == 0)
 2717                                         sigqueue_add(&td->td_sigqueue, sig,
 2718                                             NULL);
 2719                         }
 2720 
 2721                         /*
 2722                          * If the traced bit got turned off, go back up
 2723                          * to the top to rescan signals.  This ensures
 2724                          * that p_sig* and p_sigact are consistent.
 2725                          */
 2726                         if ((p->p_flag & P_TRACED) == 0)
 2727                                 continue;
 2728                 }
 2729 
 2730                 prop = sigprop(sig);
 2731 
 2732                 /*
 2733                  * Decide whether the signal should be returned.
 2734                  * Return the signal's number, or fall through
 2735                  * to clear it from the pending mask.
 2736                  */
 2737                 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
 2738 
 2739                 case (intptr_t)SIG_DFL:
 2740                         /*
 2741                          * Don't take default actions on system processes.
 2742                          */
 2743                         if (p->p_pid <= 1) {
 2744 #ifdef DIAGNOSTIC
 2745                                 /*
 2746                                  * Are you sure you want to ignore SIGSEGV
 2747                                  * in init? XXX
 2748                                  */
 2749                                 printf("Process (pid %lu) got signal %d\n",
 2750                                         (u_long)p->p_pid, sig);
 2751 #endif
 2752                                 break;          /* == ignore */
 2753                         }
 2754                         /*
 2755                          * If there is a pending stop signal to process
 2756                          * with default action, stop here,
 2757                          * then clear the signal.  However,
 2758                          * if process is member of an orphaned
 2759                          * process group, ignore tty stop signals.
 2760                          */
 2761                         if (prop & SA_STOP) {
 2762                                 if (p->p_flag & (P_TRACED|P_WEXIT) ||
 2763                                     (p->p_pgrp->pg_jobc == 0 &&
 2764                                      prop & SA_TTYSTOP))
 2765                                         break;  /* == ignore */
 2766                                 mtx_unlock(&ps->ps_mtx);
 2767                                 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
 2768                                     &p->p_mtx.lock_object, "Catching SIGSTOP");
 2769                                 p->p_flag |= P_STOPPED_SIG;
 2770                                 p->p_xstat = sig;
 2771                                 PROC_SLOCK(p);
 2772                                 sig_suspend_threads(td, p, 0);
 2773                                 thread_suspend_switch(td, p);
 2774                                 PROC_SUNLOCK(p);
 2775                                 mtx_lock(&ps->ps_mtx);
 2776                                 break;
 2777                         } else if (prop & SA_IGNORE) {
 2778                                 /*
 2779                                  * Except for SIGCONT, shouldn't get here.
 2780                                  * Default action is to ignore; drop it.
 2781                                  */
 2782                                 break;          /* == ignore */
 2783                         } else
 2784                                 return (sig);
 2785                         /*NOTREACHED*/
 2786 
 2787                 case (intptr_t)SIG_IGN:
 2788                         /*
 2789                          * Masking above should prevent us ever trying
 2790                          * to take action on an ignored signal other
 2791                          * than SIGCONT, unless process is traced.
 2792                          */
 2793                         if ((prop & SA_CONT) == 0 &&
 2794                             (p->p_flag & P_TRACED) == 0)
 2795                                 printf("issignal\n");
 2796                         break;          /* == ignore */
 2797 
 2798                 default:
 2799                         /*
 2800                          * This signal has an action, let
 2801                          * postsig() process it.
 2802                          */
 2803                         return (sig);
 2804                 }
 2805                 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */
 2806                 sigqueue_delete(&p->p_sigqueue, sig);
 2807         }
 2808         /* NOTREACHED */
 2809 }
 2810 
 2811 void
 2812 thread_stopped(struct proc *p)
 2813 {
 2814         int n;
 2815 
 2816         PROC_LOCK_ASSERT(p, MA_OWNED);
 2817         PROC_SLOCK_ASSERT(p, MA_OWNED);
 2818         n = p->p_suspcount;
 2819         if (p == curproc)
 2820                 n++;
 2821         if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) {
 2822                 PROC_SUNLOCK(p);
 2823                 p->p_flag &= ~P_WAITED;
 2824                 PROC_LOCK(p->p_pptr);
 2825                 childproc_stopped(p, (p->p_flag & P_TRACED) ?
 2826                         CLD_TRAPPED : CLD_STOPPED);
 2827                 PROC_UNLOCK(p->p_pptr);
 2828                 PROC_SLOCK(p);
 2829         }
 2830 }
 2831 
 2832 /*
 2833  * Take the action for the specified signal
 2834  * from the current set of pending signals.
 2835  */
 2836 int
 2837 postsig(sig)
 2838         register int sig;
 2839 {
 2840         struct thread *td = curthread;
 2841         register struct proc *p = td->td_proc;
 2842         struct sigacts *ps;
 2843         sig_t action;
 2844         ksiginfo_t ksi;
 2845         sigset_t returnmask;
 2846 
 2847         KASSERT(sig != 0, ("postsig"));
 2848 
 2849         PROC_LOCK_ASSERT(p, MA_OWNED);
 2850         ps = p->p_sigacts;
 2851         mtx_assert(&ps->ps_mtx, MA_OWNED);
 2852         ksiginfo_init(&ksi);
 2853         if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 &&
 2854             sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0)
 2855                 return (0);
 2856         ksi.ksi_signo = sig;
 2857         if (ksi.ksi_code == SI_TIMER)
 2858                 itimer_accept(p, ksi.ksi_timerid, &ksi);
 2859         action = ps->ps_sigact[_SIG_IDX(sig)];
 2860 #ifdef KTRACE
 2861         if (KTRPOINT(td, KTR_PSIG))
 2862                 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ?
 2863                     &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code);
 2864 #endif
 2865         if (p->p_stops & S_SIG) {
 2866                 mtx_unlock(&ps->ps_mtx);
 2867                 stopevent(p, S_SIG, sig);
 2868                 mtx_lock(&ps->ps_mtx);
 2869         }
 2870 
 2871         if (action == SIG_DFL) {
 2872                 /*
 2873                  * Default action, where the default is to kill
 2874                  * the process.  (Other cases were ignored above.)
 2875                  */
 2876                 mtx_unlock(&ps->ps_mtx);
 2877                 sigexit(td, sig);
 2878                 /* NOTREACHED */
 2879         } else {
 2880                 /*
 2881                  * If we get here, the signal must be caught.
 2882                  */
 2883                 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig),
 2884                     ("postsig action"));
 2885                 /*
 2886                  * Set the new mask value and also defer further
 2887                  * occurrences of this signal.
 2888                  *
 2889                  * Special case: user has done a sigsuspend.  Here the
 2890                  * current mask is not of interest, but rather the
 2891                  * mask from before the sigsuspend is what we want
 2892                  * restored after the signal processing is completed.
 2893                  */
 2894                 if (td->td_pflags & TDP_OLDMASK) {
 2895                         returnmask = td->td_oldsigmask;
 2896                         td->td_pflags &= ~TDP_OLDMASK;
 2897                 } else
 2898                         returnmask = td->td_sigmask;
 2899 
 2900                 if (p->p_sig == sig) {
 2901                         p->p_code = 0;
 2902                         p->p_sig = 0;
 2903                 }
 2904                 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask);
 2905                 postsig_done(sig, td, ps);
 2906         }
 2907         return (1);
 2908 }
 2909 
 2910 /*
 2911  * Kill the current process for stated reason.
 2912  */
 2913 void
 2914 killproc(p, why)
 2915         struct proc *p;
 2916         char *why;
 2917 {
 2918 
 2919         PROC_LOCK_ASSERT(p, MA_OWNED);
 2920         CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid,
 2921             p->p_comm);
 2922         log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid,
 2923             p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why);
 2924         p->p_flag |= P_WKILLED;
 2925         kern_psignal(p, SIGKILL);
 2926 }
 2927 
 2928 /*
 2929  * Force the current process to exit with the specified signal, dumping core
 2930  * if appropriate.  We bypass the normal tests for masked and caught signals,
 2931  * allowing unrecoverable failures to terminate the process without changing
 2932  * signal state.  Mark the accounting record with the signal termination.
 2933  * If dumping core, save the signal number for the debugger.  Calls exit and
 2934  * does not return.
 2935  */
 2936 void
 2937 sigexit(td, sig)
 2938         struct thread *td;
 2939         int sig;
 2940 {
 2941         struct proc *p = td->td_proc;
 2942 
 2943         PROC_LOCK_ASSERT(p, MA_OWNED);
 2944         p->p_acflag |= AXSIG;
 2945         /*
 2946          * We must be single-threading to generate a core dump.  This
 2947          * ensures that the registers in the core file are up-to-date.
 2948          * Also, the ELF dump handler assumes that the thread list doesn't
 2949          * change out from under it.
 2950          *
 2951          * XXX If another thread attempts to single-thread before us
 2952          *     (e.g. via fork()), we won't get a dump at all.
 2953          */
 2954         if ((sigprop(sig) & SA_CORE) && thread_single(p, SINGLE_NO_EXIT) == 0) {
 2955                 p->p_sig = sig;
 2956                 /*
 2957                  * Log signals which would cause core dumps
 2958                  * (Log as LOG_INFO to appease those who don't want
 2959                  * these messages.)
 2960                  * XXX : Todo, as well as euid, write out ruid too
 2961                  * Note that coredump() drops proc lock.
 2962                  */
 2963                 if (coredump(td) == 0)
 2964                         sig |= WCOREFLAG;
 2965                 if (kern_logsigexit)
 2966                         log(LOG_INFO,
 2967                             "pid %d (%s), uid %d: exited on signal %d%s\n",
 2968                             p->p_pid, p->p_comm,
 2969                             td->td_ucred ? td->td_ucred->cr_uid : -1,
 2970                             sig &~ WCOREFLAG,
 2971                             sig & WCOREFLAG ? " (core dumped)" : "");
 2972         } else
 2973                 PROC_UNLOCK(p);
 2974         exit1(td, W_EXITCODE(0, sig));
 2975         /* NOTREACHED */
 2976 }
 2977 
 2978 /*
 2979  * Send queued SIGCHLD to parent when child process's state
 2980  * is changed.
 2981  */
 2982 static void
 2983 sigparent(struct proc *p, int reason, int status)
 2984 {
 2985         PROC_LOCK_ASSERT(p, MA_OWNED);
 2986         PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
 2987 
 2988         if (p->p_ksi != NULL) {
 2989                 p->p_ksi->ksi_signo  = SIGCHLD;
 2990                 p->p_ksi->ksi_code   = reason;
 2991                 p->p_ksi->ksi_status = status;
 2992                 p->p_ksi->ksi_pid    = p->p_pid;
 2993                 p->p_ksi->ksi_uid    = p->p_ucred->cr_ruid;
 2994                 if (KSI_ONQ(p->p_ksi))
 2995                         return;
 2996         }
 2997         pksignal(p->p_pptr, SIGCHLD, p->p_ksi);
 2998 }
 2999 
 3000 static void
 3001 childproc_jobstate(struct proc *p, int reason, int sig)
 3002 {
 3003         struct sigacts *ps;
 3004 
 3005         PROC_LOCK_ASSERT(p, MA_OWNED);
 3006         PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
 3007 
 3008         /*
 3009          * Wake up parent sleeping in kern_wait(), also send
 3010          * SIGCHLD to parent, but SIGCHLD does not guarantee
 3011          * that parent will awake, because parent may masked
 3012          * the signal.
 3013          */
 3014         p->p_pptr->p_flag |= P_STATCHILD;
 3015         wakeup(p->p_pptr);
 3016 
 3017         ps = p->p_pptr->p_sigacts;
 3018         mtx_lock(&ps->ps_mtx);
 3019         if ((ps->ps_flag & PS_NOCLDSTOP) == 0) {
 3020                 mtx_unlock(&ps->ps_mtx);
 3021                 sigparent(p, reason, sig);
 3022         } else
 3023                 mtx_unlock(&ps->ps_mtx);
 3024 }
 3025 
 3026 void
 3027 childproc_stopped(struct proc *p, int reason)
 3028 {
 3029         /* p_xstat is a plain signal number, not a full wait() status here. */
 3030         childproc_jobstate(p, reason, p->p_xstat);
 3031 }
 3032 
 3033 void
 3034 childproc_continued(struct proc *p)
 3035 {
 3036         childproc_jobstate(p, CLD_CONTINUED, SIGCONT);
 3037 }
 3038 
 3039 void
 3040 childproc_exited(struct proc *p)
 3041 {
 3042         int reason;
 3043         int xstat = p->p_xstat; /* convert to int */
 3044         int status;
 3045 
 3046         if (WCOREDUMP(xstat))
 3047                 reason = CLD_DUMPED, status = WTERMSIG(xstat);
 3048         else if (WIFSIGNALED(xstat))
 3049                 reason = CLD_KILLED, status = WTERMSIG(xstat);
 3050         else
 3051                 reason = CLD_EXITED, status = WEXITSTATUS(xstat);
 3052         /*
 3053          * XXX avoid calling wakeup(p->p_pptr), the work is
 3054          * done in exit1().
 3055          */
 3056         sigparent(p, reason, status);
 3057 }
 3058 
 3059 /*
 3060  * We only have 1 character for the core count in the format
 3061  * string, so the range will be 0-9
 3062  */
 3063 #define MAX_NUM_CORES 10
 3064 static int num_cores = 5;
 3065 
 3066 static int
 3067 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS)
 3068 {
 3069         int error;
 3070         int new_val;
 3071 
 3072         new_val = num_cores;
 3073         error = sysctl_handle_int(oidp, &new_val, 0, req);
 3074         if (error != 0 || req->newptr == NULL)
 3075                 return (error);
 3076         if (new_val > MAX_NUM_CORES)
 3077                 new_val = MAX_NUM_CORES;
 3078         if (new_val < 0)
 3079                 new_val = 0;
 3080         num_cores = new_val;
 3081         return (0);
 3082 }
 3083 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW,
 3084             0, sizeof(int), sysctl_debug_num_cores_check, "I", "");
 3085 
 3086 #if defined(COMPRESS_USER_CORES)
 3087 int compress_user_cores = 1;
 3088 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RW,
 3089     &compress_user_cores, 0, "Compression of user corefiles");
 3090 
 3091 int compress_user_cores_gzlevel = -1; /* default level */
 3092 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RW,
 3093     &compress_user_cores_gzlevel, -1, "Corefile gzip compression level");
 3094 
 3095 #define GZ_SUFFIX       ".gz"
 3096 #define GZ_SUFFIX_LEN   3
 3097 #endif
 3098 
 3099 static char corefilename[MAXPATHLEN] = {"%N.core"};
 3100 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename));
 3101 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
 3102     sizeof(corefilename), "Process corefile name format string");
 3103 
 3104 /*
 3105  * corefile_open(comm, uid, pid, td, compress, vpp, namep)
 3106  * Expand the name described in corefilename, using name, uid, and pid
 3107  * and open/create core file.
 3108  * corefilename is a printf-like string, with three format specifiers:
 3109  *      %N      name of process ("name")
 3110  *      %P      process id (pid)
 3111  *      %U      user id (uid)
 3112  * For example, "%N.core" is the default; they can be disabled completely
 3113  * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
 3114  * This is controlled by the sysctl variable kern.corefile (see above).
 3115  */
 3116 static int
 3117 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td,
 3118     int compress, struct vnode **vpp, char **namep)
 3119 {
 3120         struct nameidata nd;
 3121         struct sbuf sb;
 3122         const char *format;
 3123         char *hostname, *name;
 3124         int indexpos, i, error, cmode, flags, oflags;
 3125 
 3126         hostname = NULL;
 3127         format = corefilename;
 3128         name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO);
 3129         indexpos = -1;
 3130         (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN);
 3131         for (i = 0; format[i] != '\0'; i++) {
 3132                 switch (format[i]) {
 3133                 case '%':       /* Format character */
 3134                         i++;
 3135                         switch (format[i]) {
 3136                         case '%':
 3137                                 sbuf_putc(&sb, '%');
 3138                                 break;
 3139                         case 'H':       /* hostname */
 3140                                 if (hostname == NULL) {
 3141                                         hostname = malloc(MAXHOSTNAMELEN,
 3142                                             M_TEMP, M_WAITOK);
 3143                                 }
 3144                                 getcredhostname(td->td_ucred, hostname,
 3145                                     MAXHOSTNAMELEN);
 3146                                 sbuf_printf(&sb, "%s", hostname);
 3147                                 break;
 3148                         case 'I':       /* autoincrementing index */
 3149                                 sbuf_printf(&sb, "");
 3150                                 indexpos = sbuf_len(&sb) - 1;
 3151                                 break;
 3152                         case 'N':       /* process name */
 3153                                 sbuf_printf(&sb, "%s", comm);
 3154                                 break;
 3155                         case 'P':       /* process id */
 3156                                 sbuf_printf(&sb, "%u", pid);
 3157                                 break;
 3158                         case 'U':       /* user id */
 3159                                 sbuf_printf(&sb, "%u", uid);
 3160                                 break;
 3161                         default:
 3162                                 log(LOG_ERR,
 3163                                     "Unknown format character %c in "
 3164                                     "corename `%s'\n", format[i], format);
 3165                                 break;
 3166                         }
 3167                         break;
 3168                 default:
 3169                         sbuf_putc(&sb, format[i]);
 3170                         break;
 3171                 }
 3172         }
 3173         free(hostname, M_TEMP);
 3174 #ifdef COMPRESS_USER_CORES
 3175         if (compress)
 3176                 sbuf_printf(&sb, GZ_SUFFIX);
 3177 #endif
 3178         if (sbuf_error(&sb) != 0) {
 3179                 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too "
 3180                     "long\n", (long)pid, comm, (u_long)uid);
 3181                 sbuf_delete(&sb);
 3182                 free(name, M_TEMP);
 3183                 return (ENOMEM);
 3184         }
 3185         sbuf_finish(&sb);
 3186         sbuf_delete(&sb);
 3187 
 3188         cmode = S_IRUSR | S_IWUSR;
 3189         oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE |
 3190             (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0);
 3191 
 3192         /*
 3193          * If the core format has a %I in it, then we need to check
 3194          * for existing corefiles before returning a name.
 3195          * To do this we iterate over 0..num_cores to find a
 3196          * non-existing core file name to use.
 3197          */
 3198         if (indexpos != -1) {
 3199                 for (i = 0; i < num_cores; i++) {
 3200                         flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW;
 3201                         name[indexpos] = '' + i;
 3202                         NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td);
 3203                         error = vn_open_cred(&nd, &flags, cmode, oflags,
 3204                             td->td_ucred, NULL);
 3205                         if (error) {
 3206                                 if (error == EEXIST)
 3207                                         continue;
 3208                                 log(LOG_ERR,
 3209                                     "pid %d (%s), uid (%u):  Path `%s' failed "
 3210                                     "on initial open test, error = %d\n",
 3211                                     pid, comm, uid, name, error);
 3212                         }
 3213                         goto out;
 3214                 }
 3215         }
 3216 
 3217         flags = O_CREAT | FWRITE | O_NOFOLLOW;
 3218         NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td);
 3219         error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL);
 3220 out:
 3221         if (error) {
 3222 #ifdef AUDIT
 3223                 audit_proc_coredump(td, name, error);
 3224 #endif
 3225                 free(name, M_TEMP);
 3226                 return (error);
 3227         }
 3228         NDFREE(&nd, NDF_ONLY_PNBUF);
 3229         *vpp = nd.ni_vp;
 3230         *namep = name;
 3231         return (0);
 3232 }
 3233 
 3234 /*
 3235  * Dump a process' core.  The main routine does some
 3236  * policy checking, and creates the name of the coredump;
 3237  * then it passes on a vnode and a size limit to the process-specific
 3238  * coredump routine if there is one; if there _is not_ one, it returns
 3239  * ENOSYS; otherwise it returns the error from the process-specific routine.
 3240  */
 3241 
 3242 static int
 3243 coredump(struct thread *td)
 3244 {
 3245         struct proc *p = td->td_proc;
 3246         struct ucred *cred = td->td_ucred;
 3247         struct vnode *vp;
 3248         struct flock lf;
 3249         struct vattr vattr;
 3250         int error, error1, locked;
 3251         struct mount *mp;
 3252         char *name;                     /* name of corefile */
 3253         off_t limit;
 3254         int compress;
 3255 
 3256 #ifdef COMPRESS_USER_CORES
 3257         compress = compress_user_cores;
 3258 #else
 3259         compress = 0;
 3260 #endif
 3261         PROC_LOCK_ASSERT(p, MA_OWNED);
 3262         MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td);
 3263         _STOPEVENT(p, S_CORE, 0);
 3264 
 3265         if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) ||
 3266             (p->p_flag2 & P2_NOTRACE) != 0) {
 3267                 PROC_UNLOCK(p);
 3268                 return (EFAULT);
 3269         }
 3270 
 3271         /*
 3272          * Note that the bulk of limit checking is done after
 3273          * the corefile is created.  The exception is if the limit
 3274          * for corefiles is 0, in which case we don't bother
 3275          * creating the corefile at all.  This layout means that
 3276          * a corefile is truncated instead of not being created,
 3277          * if it is larger than the limit.
 3278          */
 3279         limit = (off_t)lim_cur(p, RLIMIT_CORE);
 3280         if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) {
 3281                 PROC_UNLOCK(p);
 3282                 return (EFBIG);
 3283         }
 3284         PROC_UNLOCK(p);
 3285 
 3286 restart:
 3287         error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, compress,
 3288             &vp, &name);
 3289         if (error != 0)
 3290                 return (error);
 3291 
 3292         /* Don't dump to non-regular files or files with links. */
 3293         if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 ||
 3294             vattr.va_nlink != 1) {
 3295                 VOP_UNLOCK(vp, 0);
 3296                 error = EFAULT;
 3297                 goto close;
 3298         }
 3299 
 3300         VOP_UNLOCK(vp, 0);
 3301         lf.l_whence = SEEK_SET;
 3302         lf.l_start = 0;
 3303         lf.l_len = 0;
 3304         lf.l_type = F_WRLCK;
 3305         locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0);
 3306 
 3307         if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
 3308                 lf.l_type = F_UNLCK;
 3309                 if (locked)
 3310                         VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
 3311                 if ((error = vn_close(vp, FWRITE, cred, td)) != 0)
 3312                         goto out;
 3313                 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
 3314                         goto out;
 3315                 free(name, M_TEMP);
 3316                 goto restart;
 3317         }
 3318 
 3319         VATTR_NULL(&vattr);
 3320         vattr.va_size = 0;
 3321         if (set_core_nodump_flag)
 3322                 vattr.va_flags = UF_NODUMP;
 3323         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 3324         VOP_SETATTR(vp, &vattr, cred);
 3325         VOP_UNLOCK(vp, 0);
 3326         vn_finished_write(mp);
 3327         PROC_LOCK(p);
 3328         p->p_acflag |= ACORE;
 3329         PROC_UNLOCK(p);
 3330 
 3331         if (p->p_sysent->sv_coredump != NULL) {
 3332                 error = p->p_sysent->sv_coredump(td, vp, limit,
 3333                     compress ? IMGACT_CORE_COMPRESS : 0);
 3334         } else {
 3335                 error = ENOSYS;
 3336         }
 3337 
 3338         if (locked) {
 3339                 lf.l_type = F_UNLCK;
 3340                 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
 3341         }
 3342 close:
 3343         error1 = vn_close(vp, FWRITE, cred, td);
 3344         if (error == 0)
 3345                 error = error1;
 3346 out:
 3347 #ifdef AUDIT
 3348         audit_proc_coredump(td, name, error);
 3349 #endif
 3350         free(name, M_TEMP);
 3351         return (error);
 3352 }
 3353 
 3354 /*
 3355  * Nonexistent system call-- signal process (may want to handle it).  Flag
 3356  * error in case process won't see signal immediately (blocked or ignored).
 3357  */
 3358 #ifndef _SYS_SYSPROTO_H_
 3359 struct nosys_args {
 3360         int     dummy;
 3361 };
 3362 #endif
 3363 /* ARGSUSED */
 3364 int
 3365 nosys(td, args)
 3366         struct thread *td;
 3367         struct nosys_args *args;
 3368 {
 3369         struct proc *p = td->td_proc;
 3370 
 3371         PROC_LOCK(p);
 3372         tdsignal(td, SIGSYS);
 3373         PROC_UNLOCK(p);
 3374         return (ENOSYS);
 3375 }
 3376 
 3377 /*
 3378  * Send a SIGIO or SIGURG signal to a process or process group using stored
 3379  * credentials rather than those of the current process.
 3380  */
 3381 void
 3382 pgsigio(sigiop, sig, checkctty)
 3383         struct sigio **sigiop;
 3384         int sig, checkctty;
 3385 {
 3386         ksiginfo_t ksi;
 3387         struct sigio *sigio;
 3388 
 3389         ksiginfo_init(&ksi);
 3390         ksi.ksi_signo = sig;
 3391         ksi.ksi_code = SI_KERNEL;
 3392 
 3393         SIGIO_LOCK();
 3394         sigio = *sigiop;
 3395         if (sigio == NULL) {
 3396                 SIGIO_UNLOCK();
 3397                 return;
 3398         }
 3399         if (sigio->sio_pgid > 0) {
 3400                 PROC_LOCK(sigio->sio_proc);
 3401                 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred))
 3402                         kern_psignal(sigio->sio_proc, sig);
 3403                 PROC_UNLOCK(sigio->sio_proc);
 3404         } else if (sigio->sio_pgid < 0) {
 3405                 struct proc *p;
 3406 
 3407                 PGRP_LOCK(sigio->sio_pgrp);
 3408                 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
 3409                         PROC_LOCK(p);
 3410                         if (p->p_state == PRS_NORMAL &&
 3411                             CANSIGIO(sigio->sio_ucred, p->p_ucred) &&
 3412                             (checkctty == 0 || (p->p_flag & P_CONTROLT)))
 3413                                 kern_psignal(p, sig);
 3414                         PROC_UNLOCK(p);
 3415                 }
 3416                 PGRP_UNLOCK(sigio->sio_pgrp);
 3417         }
 3418         SIGIO_UNLOCK();
 3419 }
 3420 
 3421 static int
 3422 filt_sigattach(struct knote *kn)
 3423 {
 3424         struct proc *p = curproc;
 3425 
 3426         kn->kn_ptr.p_proc = p;
 3427         kn->kn_flags |= EV_CLEAR;               /* automatically set */
 3428 
 3429         knlist_add(&p->p_klist, kn, 0);
 3430 
 3431         return (0);
 3432 }
 3433 
 3434 static void
 3435 filt_sigdetach(struct knote *kn)
 3436 {
 3437         struct proc *p = kn->kn_ptr.p_proc;
 3438 
 3439         knlist_remove(&p->p_klist, kn, 0);
 3440 }
 3441 
 3442 /*
 3443  * signal knotes are shared with proc knotes, so we apply a mask to
 3444  * the hint in order to differentiate them from process hints.  This
 3445  * could be avoided by using a signal-specific knote list, but probably
 3446  * isn't worth the trouble.
 3447  */
 3448 static int
 3449 filt_signal(struct knote *kn, long hint)
 3450 {
 3451 
 3452         if (hint & NOTE_SIGNAL) {
 3453                 hint &= ~NOTE_SIGNAL;
 3454 
 3455                 if (kn->kn_id == hint)
 3456                         kn->kn_data++;
 3457         }
 3458         return (kn->kn_data != 0);
 3459 }
 3460 
 3461 struct sigacts *
 3462 sigacts_alloc(void)
 3463 {
 3464         struct sigacts *ps;
 3465 
 3466         ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO);
 3467         ps->ps_refcnt = 1;
 3468         mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF);
 3469         return (ps);
 3470 }
 3471 
 3472 void
 3473 sigacts_free(struct sigacts *ps)
 3474 {
 3475 
 3476         if (refcount_release(&ps->ps_refcnt) == 0)
 3477                 return;
 3478         mtx_destroy(&ps->ps_mtx);
 3479         free(ps, M_SUBPROC);
 3480 }
 3481 
 3482 struct sigacts *
 3483 sigacts_hold(struct sigacts *ps)
 3484 {
 3485 
 3486         refcount_acquire(&ps->ps_refcnt);
 3487         return (ps);
 3488 }
 3489 
 3490 void
 3491 sigacts_copy(struct sigacts *dest, struct sigacts *src)
 3492 {
 3493 
 3494         KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest"));
 3495         mtx_lock(&src->ps_mtx);
 3496         bcopy(src, dest, offsetof(struct sigacts, ps_refcnt));
 3497         mtx_unlock(&src->ps_mtx);
 3498 }
 3499 
 3500 int
 3501 sigacts_shared(struct sigacts *ps)
 3502 {
 3503 
 3504         return (ps->ps_refcnt > 1);
 3505 }

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