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.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
40 #include "opt_compat.h"
42 #include "opt_ktrace.h"
44 #include <sys/param.h>
45 #include <sys/ctype.h>
46 #include <sys/systm.h>
47 #include <sys/signalvar.h>
48 #include <sys/vnode.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>
58 #include <sys/ktrace.h>
60 #include <sys/malloc.h>
61 #include <sys/mutex.h>
62 #include <sys/refcount.h>
63 #include <sys/namei.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>
72 #include <sys/sleepqueue.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>
85 #include <vm/vm_extern.h>
90 #include <machine/cpu.h>
92 #include <security/audit/audit.h>
94 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */
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",
101 SDT_PROBE_DEFINE3(proc, kernel, , signal__discard,
102 "struct thread *", "struct proc *", "int");
104 static int coredump(struct thread *);
105 static int killpg1(struct thread *td, int sig, int pgid, int all,
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);
117 static uma_zone_t ksiginfo_zone = NULL;
118 struct filterops sig_filtops = {
120 .f_attach = filt_sigattach,
121 .f_detach = filt_sigdetach,
122 .f_event = filt_signal,
125 static int kern_logsigexit = 1;
126 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
128 "Log processes quitting on abnormal signals to syslog(3)");
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");
134 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0,
135 "POSIX real time signal");
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");
141 static int preallocate_siginfo = 1024;
142 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN,
143 &preallocate_siginfo, 0, "Preallocated signal memory size");
145 static int signal_overflow = 0;
146 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD,
147 &signal_overflow, 0, "Number of signals overflew");
149 static int signal_alloc_fail = 0;
150 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD,
151 &signal_alloc_fail, 0, "signals failed to be allocated");
153 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL);
156 * Policy -- Can ucred cr1 send SIGIO to process cr2?
157 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG
158 * in the right situations.
160 #define CANSIGIO(cr1, cr2) \
161 ((cr1)->cr_uid == 0 || \
162 (cr1)->cr_ruid == (cr2)->cr_ruid || \
163 (cr1)->cr_uid == (cr2)->cr_ruid || \
164 (cr1)->cr_ruid == (cr2)->cr_uid || \
165 (cr1)->cr_uid == (cr2)->cr_uid)
167 static int sugid_coredump;
168 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN,
169 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core");
171 static int capmode_coredump;
172 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN,
173 &capmode_coredump, 0, "Allow processes in capability mode to dump core");
175 static int do_coredump = 1;
176 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
177 &do_coredump, 0, "Enable/Disable coredumps");
179 static int set_core_nodump_flag = 0;
180 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag,
181 0, "Enable setting the NODUMP flag on coredump files");
183 static int coredump_devctl = 0;
184 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl,
185 0, "Generate a devctl notification when processes coredump");
188 * Signal properties and actions.
189 * The array below categorizes the signals and their default actions
190 * according to the following properties:
192 #define SA_KILL 0x01 /* terminates process by default */
193 #define SA_CORE 0x02 /* ditto and coredumps */
194 #define SA_STOP 0x04 /* suspend process */
195 #define SA_TTYSTOP 0x08 /* ditto, from tty */
196 #define SA_IGNORE 0x10 /* ignore by default */
197 #define SA_CONT 0x20 /* continue if suspended */
198 #define SA_CANTMASK 0x40 /* non-maskable, catchable */
200 static int sigproptbl[NSIG] = {
201 SA_KILL, /* SIGHUP */
202 SA_KILL, /* SIGINT */
203 SA_KILL|SA_CORE, /* SIGQUIT */
204 SA_KILL|SA_CORE, /* SIGILL */
205 SA_KILL|SA_CORE, /* SIGTRAP */
206 SA_KILL|SA_CORE, /* SIGABRT */
207 SA_KILL|SA_CORE, /* SIGEMT */
208 SA_KILL|SA_CORE, /* SIGFPE */
209 SA_KILL, /* SIGKILL */
210 SA_KILL|SA_CORE, /* SIGBUS */
211 SA_KILL|SA_CORE, /* SIGSEGV */
212 SA_KILL|SA_CORE, /* SIGSYS */
213 SA_KILL, /* SIGPIPE */
214 SA_KILL, /* SIGALRM */
215 SA_KILL, /* SIGTERM */
216 SA_IGNORE, /* SIGURG */
217 SA_STOP, /* SIGSTOP */
218 SA_STOP|SA_TTYSTOP, /* SIGTSTP */
219 SA_IGNORE|SA_CONT, /* SIGCONT */
220 SA_IGNORE, /* SIGCHLD */
221 SA_STOP|SA_TTYSTOP, /* SIGTTIN */
222 SA_STOP|SA_TTYSTOP, /* SIGTTOU */
223 SA_IGNORE, /* SIGIO */
224 SA_KILL, /* SIGXCPU */
225 SA_KILL, /* SIGXFSZ */
226 SA_KILL, /* SIGVTALRM */
227 SA_KILL, /* SIGPROF */
228 SA_IGNORE, /* SIGWINCH */
229 SA_IGNORE, /* SIGINFO */
230 SA_KILL, /* SIGUSR1 */
231 SA_KILL, /* SIGUSR2 */
234 static void reschedule_signals(struct proc *p, sigset_t block, int flags);
239 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t),
240 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
241 uma_prealloc(ksiginfo_zone, preallocate_siginfo);
242 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS);
243 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1);
244 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc);
248 ksiginfo_alloc(int wait)
255 if (ksiginfo_zone != NULL)
256 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags));
261 ksiginfo_free(ksiginfo_t *ksi)
263 uma_zfree(ksiginfo_zone, ksi);
267 ksiginfo_tryfree(ksiginfo_t *ksi)
269 if (!(ksi->ksi_flags & KSI_EXT)) {
270 uma_zfree(ksiginfo_zone, ksi);
277 sigqueue_init(sigqueue_t *list, struct proc *p)
279 SIGEMPTYSET(list->sq_signals);
280 SIGEMPTYSET(list->sq_kill);
281 TAILQ_INIT(&list->sq_list);
283 list->sq_flags = SQ_INIT;
287 * Get a signal's ksiginfo.
289 * 0 - signal not found
290 * others - signal number
293 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si)
295 struct proc *p = sq->sq_proc;
296 struct ksiginfo *ksi, *next;
299 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
301 if (!SIGISMEMBER(sq->sq_signals, signo))
304 if (SIGISMEMBER(sq->sq_kill, signo)) {
306 SIGDELSET(sq->sq_kill, signo);
309 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
310 if (ksi->ksi_signo == signo) {
312 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
313 ksi->ksi_sigq = NULL;
314 ksiginfo_copy(ksi, si);
315 if (ksiginfo_tryfree(ksi) && p != NULL)
324 SIGDELSET(sq->sq_signals, signo);
325 si->ksi_signo = signo;
330 sigqueue_take(ksiginfo_t *ksi)
336 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL)
340 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
341 ksi->ksi_sigq = NULL;
342 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL)
345 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL;
346 kp = TAILQ_NEXT(kp, ksi_link)) {
347 if (kp->ksi_signo == ksi->ksi_signo)
350 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo))
351 SIGDELSET(sq->sq_signals, ksi->ksi_signo);
355 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si)
357 struct proc *p = sq->sq_proc;
358 struct ksiginfo *ksi;
361 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
363 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) {
364 SIGADDSET(sq->sq_kill, signo);
368 /* directly insert the ksi, don't copy it */
369 if (si->ksi_flags & KSI_INS) {
370 if (si->ksi_flags & KSI_HEAD)
371 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link);
373 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link);
378 if (__predict_false(ksiginfo_zone == NULL)) {
379 SIGADDSET(sq->sq_kill, signo);
383 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) {
386 } else if ((ksi = ksiginfo_alloc(0)) == NULL) {
392 ksiginfo_copy(si, ksi);
393 ksi->ksi_signo = signo;
394 if (si->ksi_flags & KSI_HEAD)
395 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link);
397 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link);
401 if ((si->ksi_flags & KSI_TRAP) != 0 ||
402 (si->ksi_flags & KSI_SIGQ) == 0) {
404 SIGADDSET(sq->sq_kill, signo);
413 SIGADDSET(sq->sq_signals, signo);
418 sigqueue_flush(sigqueue_t *sq)
420 struct proc *p = sq->sq_proc;
423 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
426 PROC_LOCK_ASSERT(p, MA_OWNED);
428 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) {
429 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
430 ksi->ksi_sigq = NULL;
431 if (ksiginfo_tryfree(ksi) && p != NULL)
435 SIGEMPTYSET(sq->sq_signals);
436 SIGEMPTYSET(sq->sq_kill);
440 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set)
443 struct proc *p1, *p2;
444 ksiginfo_t *ksi, *next;
446 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited"));
447 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited"));
450 /* Move siginfo to target list */
451 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) {
452 if (SIGISMEMBER(*set, ksi->ksi_signo)) {
453 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link);
456 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link);
463 /* Move pending bits to target list */
465 SIGSETAND(tmp, *set);
466 SIGSETOR(dst->sq_kill, tmp);
467 SIGSETNAND(src->sq_kill, tmp);
469 tmp = src->sq_signals;
470 SIGSETAND(tmp, *set);
471 SIGSETOR(dst->sq_signals, tmp);
472 SIGSETNAND(src->sq_signals, tmp);
477 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo)
482 SIGADDSET(set, signo);
483 sigqueue_move_set(src, dst, &set);
488 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set)
490 struct proc *p = sq->sq_proc;
491 ksiginfo_t *ksi, *next;
493 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited"));
495 /* Remove siginfo queue */
496 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
497 if (SIGISMEMBER(*set, ksi->ksi_signo)) {
498 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
499 ksi->ksi_sigq = NULL;
500 if (ksiginfo_tryfree(ksi) && p != NULL)
504 SIGSETNAND(sq->sq_kill, *set);
505 SIGSETNAND(sq->sq_signals, *set);
509 sigqueue_delete(sigqueue_t *sq, int signo)
514 SIGADDSET(set, signo);
515 sigqueue_delete_set(sq, &set);
518 /* Remove a set of signals for a process */
520 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set)
525 PROC_LOCK_ASSERT(p, MA_OWNED);
527 sigqueue_init(&worklist, NULL);
528 sigqueue_move_set(&p->p_sigqueue, &worklist, set);
530 FOREACH_THREAD_IN_PROC(p, td0)
531 sigqueue_move_set(&td0->td_sigqueue, &worklist, set);
533 sigqueue_flush(&worklist);
537 sigqueue_delete_proc(struct proc *p, int signo)
542 SIGADDSET(set, signo);
543 sigqueue_delete_set_proc(p, &set);
547 sigqueue_delete_stopmask_proc(struct proc *p)
552 SIGADDSET(set, SIGSTOP);
553 SIGADDSET(set, SIGTSTP);
554 SIGADDSET(set, SIGTTIN);
555 SIGADDSET(set, SIGTTOU);
556 sigqueue_delete_set_proc(p, &set);
560 * Determine signal that should be delivered to thread td, the current
561 * thread, 0 if none. If there is a pending stop signal with default
562 * action, the process stops in issignal().
565 cursig(struct thread *td)
567 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
568 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED);
569 THREAD_LOCK_ASSERT(td, MA_NOTOWNED);
570 return (SIGPENDING(td) ? issignal(td) : 0);
574 * Arrange for ast() to handle unmasked pending signals on return to user
575 * mode. This must be called whenever a signal is added to td_sigqueue or
576 * unmasked in td_sigmask.
579 signotify(struct thread *td)
585 PROC_LOCK_ASSERT(p, MA_OWNED);
587 if (SIGPENDING(td)) {
589 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING;
595 sigonstack(size_t sp)
597 struct thread *td = curthread;
599 return ((td->td_pflags & TDP_ALTSTACK) ?
600 #if defined(COMPAT_43)
601 ((td->td_sigstk.ss_size == 0) ?
602 (td->td_sigstk.ss_flags & SS_ONSTACK) :
603 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size))
605 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)
614 if (sig > 0 && sig < NSIG)
615 return (sigproptbl[_SIG_IDX(sig)]);
620 sig_ffs(sigset_t *set)
624 for (i = 0; i < _SIG_WORDS; i++)
626 return (ffs(set->__bits[i]) + (i * 32));
631 sigact_flag_test(const struct sigaction *act, int flag)
635 * SA_SIGINFO is reset when signal disposition is set to
636 * ignore or default. Other flags are kept according to user
639 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO ||
640 ((__sighandler_t *)act->sa_sigaction != SIG_IGN &&
641 (__sighandler_t *)act->sa_sigaction != SIG_DFL)));
651 kern_sigaction(struct thread *td, int sig, const struct sigaction *act,
652 struct sigaction *oact, int flags)
655 struct proc *p = td->td_proc;
657 if (!_SIG_VALID(sig))
659 if (act != NULL && act->sa_handler != SIG_DFL &&
660 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK |
661 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER |
662 SA_NOCLDWAIT | SA_SIGINFO)) != 0)
667 mtx_lock(&ps->ps_mtx);
669 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
671 if (SIGISMEMBER(ps->ps_sigonstack, sig))
672 oact->sa_flags |= SA_ONSTACK;
673 if (!SIGISMEMBER(ps->ps_sigintr, sig))
674 oact->sa_flags |= SA_RESTART;
675 if (SIGISMEMBER(ps->ps_sigreset, sig))
676 oact->sa_flags |= SA_RESETHAND;
677 if (SIGISMEMBER(ps->ps_signodefer, sig))
678 oact->sa_flags |= SA_NODEFER;
679 if (SIGISMEMBER(ps->ps_siginfo, sig)) {
680 oact->sa_flags |= SA_SIGINFO;
682 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)];
684 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
685 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP)
686 oact->sa_flags |= SA_NOCLDSTOP;
687 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT)
688 oact->sa_flags |= SA_NOCLDWAIT;
691 if ((sig == SIGKILL || sig == SIGSTOP) &&
692 act->sa_handler != SIG_DFL) {
693 mtx_unlock(&ps->ps_mtx);
699 * Change setting atomically.
702 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
703 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
704 if (sigact_flag_test(act, SA_SIGINFO)) {
705 ps->ps_sigact[_SIG_IDX(sig)] =
706 (__sighandler_t *)act->sa_sigaction;
707 SIGADDSET(ps->ps_siginfo, sig);
709 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
710 SIGDELSET(ps->ps_siginfo, sig);
712 if (!sigact_flag_test(act, SA_RESTART))
713 SIGADDSET(ps->ps_sigintr, sig);
715 SIGDELSET(ps->ps_sigintr, sig);
716 if (sigact_flag_test(act, SA_ONSTACK))
717 SIGADDSET(ps->ps_sigonstack, sig);
719 SIGDELSET(ps->ps_sigonstack, sig);
720 if (sigact_flag_test(act, SA_RESETHAND))
721 SIGADDSET(ps->ps_sigreset, sig);
723 SIGDELSET(ps->ps_sigreset, sig);
724 if (sigact_flag_test(act, SA_NODEFER))
725 SIGADDSET(ps->ps_signodefer, sig);
727 SIGDELSET(ps->ps_signodefer, sig);
728 if (sig == SIGCHLD) {
729 if (act->sa_flags & SA_NOCLDSTOP)
730 ps->ps_flag |= PS_NOCLDSTOP;
732 ps->ps_flag &= ~PS_NOCLDSTOP;
733 if (act->sa_flags & SA_NOCLDWAIT) {
735 * Paranoia: since SA_NOCLDWAIT is implemented
736 * by reparenting the dying child to PID 1 (and
737 * trust it to reap the zombie), PID 1 itself
738 * is forbidden to set SA_NOCLDWAIT.
741 ps->ps_flag &= ~PS_NOCLDWAIT;
743 ps->ps_flag |= PS_NOCLDWAIT;
745 ps->ps_flag &= ~PS_NOCLDWAIT;
746 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
747 ps->ps_flag |= PS_CLDSIGIGN;
749 ps->ps_flag &= ~PS_CLDSIGIGN;
752 * Set bit in ps_sigignore for signals that are set to SIG_IGN,
753 * and for signals set to SIG_DFL where the default is to
754 * ignore. However, don't put SIGCONT in ps_sigignore, as we
755 * have to restart the process.
757 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
758 (sigprop(sig) & SA_IGNORE &&
759 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
760 /* never to be seen again */
761 sigqueue_delete_proc(p, sig);
763 /* easier in psignal */
764 SIGADDSET(ps->ps_sigignore, sig);
765 SIGDELSET(ps->ps_sigcatch, sig);
767 SIGDELSET(ps->ps_sigignore, sig);
768 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
769 SIGDELSET(ps->ps_sigcatch, sig);
771 SIGADDSET(ps->ps_sigcatch, sig);
773 #ifdef COMPAT_FREEBSD4
774 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
775 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
776 (flags & KSA_FREEBSD4) == 0)
777 SIGDELSET(ps->ps_freebsd4, sig);
779 SIGADDSET(ps->ps_freebsd4, sig);
782 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
783 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
784 (flags & KSA_OSIGSET) == 0)
785 SIGDELSET(ps->ps_osigset, sig);
787 SIGADDSET(ps->ps_osigset, sig);
790 mtx_unlock(&ps->ps_mtx);
795 #ifndef _SYS_SYSPROTO_H_
796 struct sigaction_args {
798 struct sigaction *act;
799 struct sigaction *oact;
803 sys_sigaction(td, uap)
805 register struct sigaction_args *uap;
807 struct sigaction act, oact;
808 register struct sigaction *actp, *oactp;
811 actp = (uap->act != NULL) ? &act : NULL;
812 oactp = (uap->oact != NULL) ? &oact : NULL;
814 error = copyin(uap->act, actp, sizeof(act));
818 error = kern_sigaction(td, uap->sig, actp, oactp, 0);
820 error = copyout(oactp, uap->oact, sizeof(oact));
824 #ifdef COMPAT_FREEBSD4
825 #ifndef _SYS_SYSPROTO_H_
826 struct freebsd4_sigaction_args {
828 struct sigaction *act;
829 struct sigaction *oact;
833 freebsd4_sigaction(td, uap)
835 register struct freebsd4_sigaction_args *uap;
837 struct sigaction act, oact;
838 register struct sigaction *actp, *oactp;
842 actp = (uap->act != NULL) ? &act : NULL;
843 oactp = (uap->oact != NULL) ? &oact : NULL;
845 error = copyin(uap->act, actp, sizeof(act));
849 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4);
851 error = copyout(oactp, uap->oact, sizeof(oact));
854 #endif /* COMAPT_FREEBSD4 */
856 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
857 #ifndef _SYS_SYSPROTO_H_
858 struct osigaction_args {
860 struct osigaction *nsa;
861 struct osigaction *osa;
867 register struct osigaction_args *uap;
869 struct osigaction sa;
870 struct sigaction nsa, osa;
871 register struct sigaction *nsap, *osap;
874 if (uap->signum <= 0 || uap->signum >= ONSIG)
877 nsap = (uap->nsa != NULL) ? &nsa : NULL;
878 osap = (uap->osa != NULL) ? &osa : NULL;
881 error = copyin(uap->nsa, &sa, sizeof(sa));
884 nsap->sa_handler = sa.sa_handler;
885 nsap->sa_flags = sa.sa_flags;
886 OSIG2SIG(sa.sa_mask, nsap->sa_mask);
888 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
889 if (osap && !error) {
890 sa.sa_handler = osap->sa_handler;
891 sa.sa_flags = osap->sa_flags;
892 SIG2OSIG(osap->sa_mask, sa.sa_mask);
893 error = copyout(&sa, uap->osa, sizeof(sa));
898 #if !defined(__i386__)
899 /* Avoid replicating the same stub everywhere */
903 struct osigreturn_args *uap;
906 return (nosys(td, (struct nosys_args *)uap));
909 #endif /* COMPAT_43 */
912 * Initialize signal state for process 0;
913 * set to ignore signals that are ignored by default.
924 mtx_lock(&ps->ps_mtx);
925 for (i = 1; i <= NSIG; i++) {
926 if (sigprop(i) & SA_IGNORE && i != SIGCONT) {
927 SIGADDSET(ps->ps_sigignore, i);
930 mtx_unlock(&ps->ps_mtx);
935 * Reset specified signal to the default disposition.
938 sigdflt(struct sigacts *ps, int sig)
941 mtx_assert(&ps->ps_mtx, MA_OWNED);
942 SIGDELSET(ps->ps_sigcatch, sig);
943 if ((sigprop(sig) & SA_IGNORE) != 0 && sig != SIGCONT)
944 SIGADDSET(ps->ps_sigignore, sig);
945 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
946 SIGDELSET(ps->ps_siginfo, sig);
950 * Reset signals for an exec of the specified process.
953 execsigs(struct proc *p)
960 * Reset caught signals. Held signals remain held
961 * through td_sigmask (unless they were caught,
962 * and are now ignored by default).
964 PROC_LOCK_ASSERT(p, MA_OWNED);
965 td = FIRST_THREAD_IN_PROC(p);
967 mtx_lock(&ps->ps_mtx);
968 while (SIGNOTEMPTY(ps->ps_sigcatch)) {
969 sig = sig_ffs(&ps->ps_sigcatch);
971 if ((sigprop(sig) & SA_IGNORE) != 0)
972 sigqueue_delete_proc(p, sig);
975 * Reset stack state to the user stack.
976 * Clear set of signals caught on the signal stack.
978 td->td_sigstk.ss_flags = SS_DISABLE;
979 td->td_sigstk.ss_size = 0;
980 td->td_sigstk.ss_sp = 0;
981 td->td_pflags &= ~TDP_ALTSTACK;
983 * Reset no zombies if child dies flag as Solaris does.
985 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN);
986 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
987 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL;
988 mtx_unlock(&ps->ps_mtx);
994 * Manipulate signal mask.
997 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset,
1000 sigset_t new_block, oset1;
1005 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0)
1006 PROC_LOCK_ASSERT(p, MA_OWNED);
1009 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0
1010 ? MA_OWNED : MA_NOTOWNED);
1012 *oset = td->td_sigmask;
1019 oset1 = td->td_sigmask;
1020 SIGSETOR(td->td_sigmask, *set);
1021 new_block = td->td_sigmask;
1022 SIGSETNAND(new_block, oset1);
1025 SIGSETNAND(td->td_sigmask, *set);
1030 oset1 = td->td_sigmask;
1031 if (flags & SIGPROCMASK_OLD)
1032 SIGSETLO(td->td_sigmask, *set);
1034 td->td_sigmask = *set;
1035 new_block = td->td_sigmask;
1036 SIGSETNAND(new_block, oset1);
1045 * The new_block set contains signals that were not previously
1046 * blocked, but are blocked now.
1048 * In case we block any signal that was not previously blocked
1049 * for td, and process has the signal pending, try to schedule
1050 * signal delivery to some thread that does not block the
1051 * signal, possibly waking it up.
1053 if (p->p_numthreads != 1)
1054 reschedule_signals(p, new_block, flags);
1058 if (!(flags & SIGPROCMASK_PROC_LOCKED))
1063 #ifndef _SYS_SYSPROTO_H_
1064 struct sigprocmask_args {
1066 const sigset_t *set;
1071 sys_sigprocmask(td, uap)
1072 register struct thread *td;
1073 struct sigprocmask_args *uap;
1076 sigset_t *setp, *osetp;
1079 setp = (uap->set != NULL) ? &set : NULL;
1080 osetp = (uap->oset != NULL) ? &oset : NULL;
1082 error = copyin(uap->set, setp, sizeof(set));
1086 error = kern_sigprocmask(td, uap->how, setp, osetp, 0);
1087 if (osetp && !error) {
1088 error = copyout(osetp, uap->oset, sizeof(oset));
1093 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1094 #ifndef _SYS_SYSPROTO_H_
1095 struct osigprocmask_args {
1101 osigprocmask(td, uap)
1102 register struct thread *td;
1103 struct osigprocmask_args *uap;
1108 OSIG2SIG(uap->mask, set);
1109 error = kern_sigprocmask(td, uap->how, &set, &oset, 1);
1110 SIG2OSIG(oset, td->td_retval[0]);
1113 #endif /* COMPAT_43 */
1116 sys_sigwait(struct thread *td, struct sigwait_args *uap)
1122 error = copyin(uap->set, &set, sizeof(set));
1124 td->td_retval[0] = error;
1128 error = kern_sigtimedwait(td, set, &ksi, NULL);
1130 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT)
1132 if (error == ERESTART)
1134 td->td_retval[0] = error;
1138 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo));
1139 td->td_retval[0] = error;
1144 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap)
1147 struct timespec *timeout;
1153 error = copyin(uap->timeout, &ts, sizeof(ts));
1161 error = copyin(uap->set, &set, sizeof(set));
1165 error = kern_sigtimedwait(td, set, &ksi, timeout);
1170 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t));
1173 td->td_retval[0] = ksi.ksi_signo;
1178 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap)
1184 error = copyin(uap->set, &set, sizeof(set));
1188 error = kern_sigtimedwait(td, set, &ksi, NULL);
1193 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t));
1196 td->td_retval[0] = ksi.ksi_signo;
1201 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi,
1202 struct timespec *timeout)
1205 sigset_t saved_mask, new_block;
1207 int error, sig, timo, timevalid = 0;
1208 struct timespec rts, ets, ts;
1216 if (timeout != NULL) {
1217 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) {
1219 getnanouptime(&rts);
1221 timespecadd(&ets, timeout);
1225 /* Some signals can not be waited for. */
1226 SIG_CANTMASK(waitset);
1229 saved_mask = td->td_sigmask;
1230 SIGSETNAND(td->td_sigmask, waitset);
1232 mtx_lock(&ps->ps_mtx);
1234 mtx_unlock(&ps->ps_mtx);
1235 if (sig != 0 && SIGISMEMBER(waitset, sig)) {
1236 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 ||
1237 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) {
1247 * POSIX says this must be checked after looking for pending
1250 if (timeout != NULL) {
1255 getnanouptime(&rts);
1256 if (timespeccmp(&rts, &ets, >=)) {
1261 timespecsub(&ts, &rts);
1262 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1268 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo);
1270 if (timeout != NULL) {
1271 if (error == ERESTART) {
1272 /* Timeout can not be restarted. */
1274 } else if (error == EAGAIN) {
1275 /* We will calculate timeout by ourself. */
1281 new_block = saved_mask;
1282 SIGSETNAND(new_block, td->td_sigmask);
1283 td->td_sigmask = saved_mask;
1285 * Fewer signals can be delivered to us, reschedule signal
1288 if (p->p_numthreads != 1)
1289 reschedule_signals(p, new_block, 0);
1292 SDT_PROBE(proc, kernel, , signal__clear, sig, ksi, 0, 0, 0);
1294 if (ksi->ksi_code == SI_TIMER)
1295 itimer_accept(p, ksi->ksi_timerid, ksi);
1298 if (KTRPOINT(td, KTR_PSIG)) {
1301 mtx_lock(&ps->ps_mtx);
1302 action = ps->ps_sigact[_SIG_IDX(sig)];
1303 mtx_unlock(&ps->ps_mtx);
1304 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code);
1314 #ifndef _SYS_SYSPROTO_H_
1315 struct sigpending_args {
1320 sys_sigpending(td, uap)
1322 struct sigpending_args *uap;
1324 struct proc *p = td->td_proc;
1328 pending = p->p_sigqueue.sq_signals;
1329 SIGSETOR(pending, td->td_sigqueue.sq_signals);
1331 return (copyout(&pending, uap->set, sizeof(sigset_t)));
1334 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1335 #ifndef _SYS_SYSPROTO_H_
1336 struct osigpending_args {
1341 osigpending(td, uap)
1343 struct osigpending_args *uap;
1345 struct proc *p = td->td_proc;
1349 pending = p->p_sigqueue.sq_signals;
1350 SIGSETOR(pending, td->td_sigqueue.sq_signals);
1352 SIG2OSIG(pending, td->td_retval[0]);
1355 #endif /* COMPAT_43 */
1357 #if defined(COMPAT_43)
1359 * Generalized interface signal handler, 4.3-compatible.
1361 #ifndef _SYS_SYSPROTO_H_
1362 struct osigvec_args {
1372 register struct osigvec_args *uap;
1375 struct sigaction nsa, osa;
1376 register struct sigaction *nsap, *osap;
1379 if (uap->signum <= 0 || uap->signum >= ONSIG)
1381 nsap = (uap->nsv != NULL) ? &nsa : NULL;
1382 osap = (uap->osv != NULL) ? &osa : NULL;
1384 error = copyin(uap->nsv, &vec, sizeof(vec));
1387 nsap->sa_handler = vec.sv_handler;
1388 OSIG2SIG(vec.sv_mask, nsap->sa_mask);
1389 nsap->sa_flags = vec.sv_flags;
1390 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */
1392 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
1393 if (osap && !error) {
1394 vec.sv_handler = osap->sa_handler;
1395 SIG2OSIG(osap->sa_mask, vec.sv_mask);
1396 vec.sv_flags = osap->sa_flags;
1397 vec.sv_flags &= ~SA_NOCLDWAIT;
1398 vec.sv_flags ^= SA_RESTART;
1399 error = copyout(&vec, uap->osv, sizeof(vec));
1404 #ifndef _SYS_SYSPROTO_H_
1405 struct osigblock_args {
1411 register struct thread *td;
1412 struct osigblock_args *uap;
1416 OSIG2SIG(uap->mask, set);
1417 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0);
1418 SIG2OSIG(oset, td->td_retval[0]);
1422 #ifndef _SYS_SYSPROTO_H_
1423 struct osigsetmask_args {
1428 osigsetmask(td, uap)
1430 struct osigsetmask_args *uap;
1434 OSIG2SIG(uap->mask, set);
1435 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0);
1436 SIG2OSIG(oset, td->td_retval[0]);
1439 #endif /* COMPAT_43 */
1442 * Suspend calling thread until signal, providing mask to be set in the
1445 #ifndef _SYS_SYSPROTO_H_
1446 struct sigsuspend_args {
1447 const sigset_t *sigmask;
1452 sys_sigsuspend(td, uap)
1454 struct sigsuspend_args *uap;
1459 error = copyin(uap->sigmask, &mask, sizeof(mask));
1462 return (kern_sigsuspend(td, mask));
1466 kern_sigsuspend(struct thread *td, sigset_t mask)
1468 struct proc *p = td->td_proc;
1472 * When returning from sigsuspend, we want
1473 * the old mask to be restored after the
1474 * signal handler has finished. Thus, we
1475 * save it here and mark the sigacts structure
1479 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask,
1480 SIGPROCMASK_PROC_LOCKED);
1481 td->td_pflags |= TDP_OLDMASK;
1484 * Process signals now. Otherwise, we can get spurious wakeup
1485 * due to signal entered process queue, but delivered to other
1486 * thread. But sigsuspend should return only on signal
1489 (p->p_sysent->sv_set_syscall_retval)(td, EINTR);
1490 for (has_sig = 0; !has_sig;) {
1491 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause",
1494 thread_suspend_check(0);
1495 mtx_lock(&p->p_sigacts->ps_mtx);
1496 while ((sig = cursig(td)) != 0)
1497 has_sig += postsig(sig);
1498 mtx_unlock(&p->p_sigacts->ps_mtx);
1501 td->td_errno = EINTR;
1502 td->td_pflags |= TDP_NERRNO;
1503 return (EJUSTRETURN);
1506 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1508 * Compatibility sigsuspend call for old binaries. Note nonstandard calling
1509 * convention: libc stub passes mask, not pointer, to save a copyin.
1511 #ifndef _SYS_SYSPROTO_H_
1512 struct osigsuspend_args {
1518 osigsuspend(td, uap)
1520 struct osigsuspend_args *uap;
1524 OSIG2SIG(uap->mask, mask);
1525 return (kern_sigsuspend(td, mask));
1527 #endif /* COMPAT_43 */
1529 #if defined(COMPAT_43)
1530 #ifndef _SYS_SYSPROTO_H_
1531 struct osigstack_args {
1532 struct sigstack *nss;
1533 struct sigstack *oss;
1540 register struct osigstack_args *uap;
1542 struct sigstack nss, oss;
1545 if (uap->nss != NULL) {
1546 error = copyin(uap->nss, &nss, sizeof(nss));
1550 oss.ss_sp = td->td_sigstk.ss_sp;
1551 oss.ss_onstack = sigonstack(cpu_getstack(td));
1552 if (uap->nss != NULL) {
1553 td->td_sigstk.ss_sp = nss.ss_sp;
1554 td->td_sigstk.ss_size = 0;
1555 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK;
1556 td->td_pflags |= TDP_ALTSTACK;
1558 if (uap->oss != NULL)
1559 error = copyout(&oss, uap->oss, sizeof(oss));
1563 #endif /* COMPAT_43 */
1565 #ifndef _SYS_SYSPROTO_H_
1566 struct sigaltstack_args {
1573 sys_sigaltstack(td, uap)
1575 register struct sigaltstack_args *uap;
1580 if (uap->ss != NULL) {
1581 error = copyin(uap->ss, &ss, sizeof(ss));
1585 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL,
1586 (uap->oss != NULL) ? &oss : NULL);
1589 if (uap->oss != NULL)
1590 error = copyout(&oss, uap->oss, sizeof(stack_t));
1595 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss)
1597 struct proc *p = td->td_proc;
1600 oonstack = sigonstack(cpu_getstack(td));
1603 *oss = td->td_sigstk;
1604 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK)
1605 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
1611 if ((ss->ss_flags & ~SS_DISABLE) != 0)
1613 if (!(ss->ss_flags & SS_DISABLE)) {
1614 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
1617 td->td_sigstk = *ss;
1618 td->td_pflags |= TDP_ALTSTACK;
1620 td->td_pflags &= ~TDP_ALTSTACK;
1627 * Common code for kill process group/broadcast kill.
1628 * cp is calling process.
1631 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi)
1643 sx_slock(&allproc_lock);
1644 FOREACH_PROC_IN_SYSTEM(p) {
1646 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
1647 p == td->td_proc || p->p_state == PRS_NEW) {
1651 err = p_cansignal(td, p, sig);
1654 pksignal(p, sig, ksi);
1657 else if (ret == ESRCH)
1661 sx_sunlock(&allproc_lock);
1663 sx_slock(&proctree_lock);
1666 * zero pgid means send to my process group.
1668 pgrp = td->td_proc->p_pgrp;
1671 pgrp = pgfind(pgid);
1673 sx_sunlock(&proctree_lock);
1677 sx_sunlock(&proctree_lock);
1678 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
1680 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
1681 p->p_state == PRS_NEW) {
1685 err = p_cansignal(td, p, sig);
1688 pksignal(p, sig, ksi);
1691 else if (ret == ESRCH)
1700 #ifndef _SYS_SYSPROTO_H_
1708 sys_kill(struct thread *td, struct kill_args *uap)
1715 * A process in capability mode can send signals only to himself.
1716 * The main rationale behind this is that abort(3) is implemented as
1717 * kill(getpid(), SIGABRT).
1719 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid)
1722 AUDIT_ARG_SIGNUM(uap->signum);
1723 AUDIT_ARG_PID(uap->pid);
1724 if ((u_int)uap->signum > _SIG_MAXSIG)
1727 ksiginfo_init(&ksi);
1728 ksi.ksi_signo = uap->signum;
1729 ksi.ksi_code = SI_USER;
1730 ksi.ksi_pid = td->td_proc->p_pid;
1731 ksi.ksi_uid = td->td_ucred->cr_ruid;
1734 /* kill single process */
1735 if ((p = pfind(uap->pid)) == NULL) {
1736 if ((p = zpfind(uap->pid)) == NULL)
1739 AUDIT_ARG_PROCESS(p);
1740 error = p_cansignal(td, p, uap->signum);
1741 if (error == 0 && uap->signum)
1742 pksignal(p, uap->signum, &ksi);
1747 case -1: /* broadcast signal */
1748 return (killpg1(td, uap->signum, 0, 1, &ksi));
1749 case 0: /* signal own process group */
1750 return (killpg1(td, uap->signum, 0, 0, &ksi));
1751 default: /* negative explicit process group */
1752 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi));
1760 struct pdkill_args *uap;
1763 cap_rights_t rights;
1766 AUDIT_ARG_SIGNUM(uap->signum);
1767 AUDIT_ARG_FD(uap->fd);
1768 if ((u_int)uap->signum > _SIG_MAXSIG)
1771 error = procdesc_find(td, uap->fd,
1772 cap_rights_init(&rights, CAP_PDKILL), &p);
1775 AUDIT_ARG_PROCESS(p);
1776 error = p_cansignal(td, p, uap->signum);
1777 if (error == 0 && uap->signum)
1778 kern_psignal(p, uap->signum);
1783 #if defined(COMPAT_43)
1784 #ifndef _SYS_SYSPROTO_H_
1785 struct okillpg_args {
1792 okillpg(struct thread *td, struct okillpg_args *uap)
1796 AUDIT_ARG_SIGNUM(uap->signum);
1797 AUDIT_ARG_PID(uap->pgid);
1798 if ((u_int)uap->signum > _SIG_MAXSIG)
1801 ksiginfo_init(&ksi);
1802 ksi.ksi_signo = uap->signum;
1803 ksi.ksi_code = SI_USER;
1804 ksi.ksi_pid = td->td_proc->p_pid;
1805 ksi.ksi_uid = td->td_ucred->cr_ruid;
1806 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi));
1808 #endif /* COMPAT_43 */
1810 #ifndef _SYS_SYSPROTO_H_
1811 struct sigqueue_args {
1814 /* union sigval */ void *value;
1818 sys_sigqueue(struct thread *td, struct sigqueue_args *uap)
1824 if ((u_int)uap->signum > _SIG_MAXSIG)
1828 * Specification says sigqueue can only send signal to
1834 if ((p = pfind(uap->pid)) == NULL) {
1835 if ((p = zpfind(uap->pid)) == NULL)
1838 error = p_cansignal(td, p, uap->signum);
1839 if (error == 0 && uap->signum != 0) {
1840 ksiginfo_init(&ksi);
1841 ksi.ksi_flags = KSI_SIGQ;
1842 ksi.ksi_signo = uap->signum;
1843 ksi.ksi_code = SI_QUEUE;
1844 ksi.ksi_pid = td->td_proc->p_pid;
1845 ksi.ksi_uid = td->td_ucred->cr_ruid;
1846 ksi.ksi_value.sival_ptr = uap->value;
1847 error = pksignal(p, ksi.ksi_signo, &ksi);
1854 * Send a signal to a process group.
1857 gsignal(int pgid, int sig, ksiginfo_t *ksi)
1862 sx_slock(&proctree_lock);
1863 pgrp = pgfind(pgid);
1864 sx_sunlock(&proctree_lock);
1866 pgsignal(pgrp, sig, 0, ksi);
1873 * Send a signal to a process group. If checktty is 1,
1874 * limit to members which have a controlling terminal.
1877 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi)
1882 PGRP_LOCK_ASSERT(pgrp, MA_OWNED);
1883 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
1885 if (p->p_state == PRS_NORMAL &&
1886 (checkctty == 0 || p->p_flag & P_CONTROLT))
1887 pksignal(p, sig, ksi);
1895 * Recalculate the signal mask and reset the signal disposition after
1896 * usermode frame for delivery is formed. Should be called after
1897 * mach-specific routine, because sysent->sv_sendsig() needs correct
1898 * ps_siginfo and signal mask.
1901 postsig_done(int sig, struct thread *td, struct sigacts *ps)
1905 mtx_assert(&ps->ps_mtx, MA_OWNED);
1906 td->td_ru.ru_nsignals++;
1907 mask = ps->ps_catchmask[_SIG_IDX(sig)];
1908 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1909 SIGADDSET(mask, sig);
1910 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL,
1911 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED);
1912 if (SIGISMEMBER(ps->ps_sigreset, sig))
1918 * Send a signal caused by a trap to the current thread. If it will be
1919 * caught immediately, deliver it with correct code. Otherwise, post it
1923 trapsignal(struct thread *td, ksiginfo_t *ksi)
1931 sig = ksi->ksi_signo;
1932 code = ksi->ksi_code;
1933 KASSERT(_SIG_VALID(sig), ("invalid signal"));
1937 mtx_lock(&ps->ps_mtx);
1938 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) &&
1939 !SIGISMEMBER(td->td_sigmask, sig)) {
1941 if (KTRPOINT(curthread, KTR_PSIG))
1942 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)],
1943 &td->td_sigmask, code);
1945 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)],
1946 ksi, &td->td_sigmask);
1947 postsig_done(sig, td, ps);
1948 mtx_unlock(&ps->ps_mtx);
1951 * Avoid a possible infinite loop if the thread
1952 * masking the signal or process is ignoring the
1955 if (kern_forcesigexit &&
1956 (SIGISMEMBER(td->td_sigmask, sig) ||
1957 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) {
1958 SIGDELSET(td->td_sigmask, sig);
1959 SIGDELSET(ps->ps_sigcatch, sig);
1960 SIGDELSET(ps->ps_sigignore, sig);
1961 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1963 mtx_unlock(&ps->ps_mtx);
1964 p->p_code = code; /* XXX for core dump/debugger */
1965 p->p_sig = sig; /* XXX to verify code */
1966 tdsendsignal(p, td, sig, ksi);
1971 static struct thread *
1972 sigtd(struct proc *p, int sig, int prop)
1974 struct thread *td, *signal_td;
1976 PROC_LOCK_ASSERT(p, MA_OWNED);
1979 * Check if current thread can handle the signal without
1980 * switching context to another thread.
1982 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig))
1985 FOREACH_THREAD_IN_PROC(p, td) {
1986 if (!SIGISMEMBER(td->td_sigmask, sig)) {
1991 if (signal_td == NULL)
1992 signal_td = FIRST_THREAD_IN_PROC(p);
1997 * Send the signal to the process. If the signal has an action, the action
1998 * is usually performed by the target process rather than the caller; we add
1999 * the signal to the set of pending signals for the process.
2002 * o When a stop signal is sent to a sleeping process that takes the
2003 * default action, the process is stopped without awakening it.
2004 * o SIGCONT restarts stopped processes (or puts them back to sleep)
2005 * regardless of the signal action (eg, blocked or ignored).
2007 * Other ignored signals are discarded immediately.
2009 * NB: This function may be entered from the debugger via the "kill" DDB
2010 * command. There is little that can be done to mitigate the possibly messy
2011 * side effects of this unwise possibility.
2014 kern_psignal(struct proc *p, int sig)
2018 ksiginfo_init(&ksi);
2019 ksi.ksi_signo = sig;
2020 ksi.ksi_code = SI_KERNEL;
2021 (void) tdsendsignal(p, NULL, sig, &ksi);
2025 pksignal(struct proc *p, int sig, ksiginfo_t *ksi)
2028 return (tdsendsignal(p, NULL, sig, ksi));
2031 /* Utility function for finding a thread to send signal event to. */
2033 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd)
2037 if (sigev->sigev_notify == SIGEV_THREAD_ID) {
2038 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid);
2050 tdsignal(struct thread *td, int sig)
2054 ksiginfo_init(&ksi);
2055 ksi.ksi_signo = sig;
2056 ksi.ksi_code = SI_KERNEL;
2057 (void) tdsendsignal(td->td_proc, td, sig, &ksi);
2061 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi)
2064 (void) tdsendsignal(td->td_proc, td, sig, ksi);
2068 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi)
2071 sigqueue_t *sigqueue;
2078 MPASS(td == NULL || p == td->td_proc);
2079 PROC_LOCK_ASSERT(p, MA_OWNED);
2081 if (!_SIG_VALID(sig))
2082 panic("%s(): invalid signal %d", __func__, sig);
2084 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__));
2087 * IEEE Std 1003.1-2001: return success when killing a zombie.
2089 if (p->p_state == PRS_ZOMBIE) {
2090 if (ksi && (ksi->ksi_flags & KSI_INS))
2091 ksiginfo_tryfree(ksi);
2096 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig);
2097 prop = sigprop(sig);
2100 td = sigtd(p, sig, prop);
2101 sigqueue = &p->p_sigqueue;
2103 sigqueue = &td->td_sigqueue;
2105 SDT_PROBE(proc, kernel, , signal__send, td, p, sig, 0, 0 );
2108 * If the signal is being ignored,
2109 * then we forget about it immediately.
2110 * (Note: we don't set SIGCONT in ps_sigignore,
2111 * and if it is set to SIG_IGN,
2112 * action will be SIG_DFL here.)
2114 mtx_lock(&ps->ps_mtx);
2115 if (SIGISMEMBER(ps->ps_sigignore, sig)) {
2116 SDT_PROBE(proc, kernel, , signal__discard, td, p, sig, 0, 0 );
2118 mtx_unlock(&ps->ps_mtx);
2119 if (ksi && (ksi->ksi_flags & KSI_INS))
2120 ksiginfo_tryfree(ksi);
2123 if (SIGISMEMBER(td->td_sigmask, sig))
2125 else if (SIGISMEMBER(ps->ps_sigcatch, sig))
2129 if (SIGISMEMBER(ps->ps_sigintr, sig))
2133 mtx_unlock(&ps->ps_mtx);
2136 sigqueue_delete_stopmask_proc(p);
2137 else if (prop & SA_STOP) {
2139 * If sending a tty stop signal to a member of an orphaned
2140 * process group, discard the signal here if the action
2141 * is default; don't stop the process below if sleeping,
2142 * and don't clear any pending SIGCONT.
2144 if ((prop & SA_TTYSTOP) &&
2145 (p->p_pgrp->pg_jobc == 0) &&
2146 (action == SIG_DFL)) {
2147 if (ksi && (ksi->ksi_flags & KSI_INS))
2148 ksiginfo_tryfree(ksi);
2151 sigqueue_delete_proc(p, SIGCONT);
2152 if (p->p_flag & P_CONTINUED) {
2153 p->p_flag &= ~P_CONTINUED;
2154 PROC_LOCK(p->p_pptr);
2155 sigqueue_take(p->p_ksi);
2156 PROC_UNLOCK(p->p_pptr);
2160 ret = sigqueue_add(sigqueue, sig, ksi);
2165 * Defer further processing for signals which are held,
2166 * except that stopped processes must be continued by SIGCONT.
2168 if (action == SIG_HOLD &&
2169 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG)))
2172 * SIGKILL: Remove procfs STOPEVENTs.
2174 if (sig == SIGKILL) {
2175 /* from procfs_ioctl.c: PIOCBIC */
2177 /* from procfs_ioctl.c: PIOCCONT */
2182 * Some signals have a process-wide effect and a per-thread
2183 * component. Most processing occurs when the process next
2184 * tries to cross the user boundary, however there are some
2185 * times when processing needs to be done immediately, such as
2186 * waking up threads so that they can cross the user boundary.
2187 * We try to do the per-process part here.
2189 if (P_SHOULDSTOP(p)) {
2190 KASSERT(!(p->p_flag & P_WEXIT),
2191 ("signal to stopped but exiting process"));
2192 if (sig == SIGKILL) {
2194 * If traced process is already stopped,
2195 * then no further action is necessary.
2197 if (p->p_flag & P_TRACED)
2200 * SIGKILL sets process running.
2201 * It will die elsewhere.
2202 * All threads must be restarted.
2204 p->p_flag &= ~P_STOPPED_SIG;
2208 if (prop & SA_CONT) {
2210 * If traced process is already stopped,
2211 * then no further action is necessary.
2213 if (p->p_flag & P_TRACED)
2216 * If SIGCONT is default (or ignored), we continue the
2217 * process but don't leave the signal in sigqueue as
2218 * it has no further action. If SIGCONT is held, we
2219 * continue the process and leave the signal in
2220 * sigqueue. If the process catches SIGCONT, let it
2221 * handle the signal itself. If it isn't waiting on
2222 * an event, it goes back to run state.
2223 * Otherwise, process goes back to sleep state.
2225 p->p_flag &= ~P_STOPPED_SIG;
2227 if (p->p_numthreads == p->p_suspcount) {
2229 p->p_flag |= P_CONTINUED;
2230 p->p_xstat = SIGCONT;
2231 PROC_LOCK(p->p_pptr);
2232 childproc_continued(p);
2233 PROC_UNLOCK(p->p_pptr);
2236 if (action == SIG_DFL) {
2237 thread_unsuspend(p);
2239 sigqueue_delete(sigqueue, sig);
2242 if (action == SIG_CATCH) {
2244 * The process wants to catch it so it needs
2245 * to run at least one thread, but which one?
2251 * The signal is not ignored or caught.
2253 thread_unsuspend(p);
2258 if (prop & SA_STOP) {
2260 * If traced process is already stopped,
2261 * then no further action is necessary.
2263 if (p->p_flag & P_TRACED)
2266 * Already stopped, don't need to stop again
2267 * (If we did the shell could get confused).
2268 * Just make sure the signal STOP bit set.
2270 p->p_flag |= P_STOPPED_SIG;
2271 sigqueue_delete(sigqueue, sig);
2276 * All other kinds of signals:
2277 * If a thread is sleeping interruptibly, simulate a
2278 * wakeup so that when it is continued it will be made
2279 * runnable and can look at the signal. However, don't make
2280 * the PROCESS runnable, leave it stopped.
2281 * It may run a bit until it hits a thread_suspend_check().
2286 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR))
2287 wakeup_swapper = sleepq_abort(td, intrval);
2294 * Mutexes are short lived. Threads waiting on them will
2295 * hit thread_suspend_check() soon.
2297 } else if (p->p_state == PRS_NORMAL) {
2298 if (p->p_flag & P_TRACED || action == SIG_CATCH) {
2299 tdsigwakeup(td, sig, action, intrval);
2303 MPASS(action == SIG_DFL);
2305 if (prop & SA_STOP) {
2306 if (p->p_flag & (P_PPWAIT|P_WEXIT))
2308 p->p_flag |= P_STOPPED_SIG;
2311 sig_suspend_threads(td, p, 1);
2312 if (p->p_numthreads == p->p_suspcount) {
2314 * only thread sending signal to another
2315 * process can reach here, if thread is sending
2316 * signal to its process, because thread does
2317 * not suspend itself here, p_numthreads
2318 * should never be equal to p_suspcount.
2322 sigqueue_delete_proc(p, p->p_xstat);
2328 /* Not in "NORMAL" state. discard the signal. */
2329 sigqueue_delete(sigqueue, sig);
2334 * The process is not stopped so we need to apply the signal to all the
2338 tdsigwakeup(td, sig, action, intrval);
2340 thread_unsuspend(p);
2343 /* If we jump here, proc slock should not be owned. */
2344 PROC_SLOCK_ASSERT(p, MA_NOTOWNED);
2349 * The force of a signal has been directed against a single
2350 * thread. We need to see what we can do about knocking it
2351 * out of any sleep it may be in etc.
2354 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval)
2356 struct proc *p = td->td_proc;
2361 PROC_LOCK_ASSERT(p, MA_OWNED);
2362 prop = sigprop(sig);
2367 * Bring the priority of a thread up if we want it to get
2368 * killed in this lifetime. Be careful to avoid bumping the
2369 * priority of the idle thread, since we still allow to signal
2372 if (action == SIG_DFL && (prop & SA_KILL) != 0 &&
2373 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td))
2374 sched_prio(td, PUSER);
2375 if (TD_ON_SLEEPQ(td)) {
2377 * If thread is sleeping uninterruptibly
2378 * we can't interrupt the sleep... the signal will
2379 * be noticed when the process returns through
2380 * trap() or syscall().
2382 if ((td->td_flags & TDF_SINTR) == 0)
2385 * If SIGCONT is default (or ignored) and process is
2386 * asleep, we are finished; the process should not
2389 if ((prop & SA_CONT) && action == SIG_DFL) {
2392 sigqueue_delete(&p->p_sigqueue, sig);
2394 * It may be on either list in this state.
2395 * Remove from both for now.
2397 sigqueue_delete(&td->td_sigqueue, sig);
2402 * Don't awaken a sleeping thread for SIGSTOP if the
2403 * STOP signal is deferred.
2405 if ((prop & SA_STOP) && (td->td_flags & TDF_SBDRY))
2409 * Give low priority threads a better chance to run.
2411 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td))
2412 sched_prio(td, PUSER);
2414 wakeup_swapper = sleepq_abort(td, intrval);
2417 * Other states do nothing with the signal immediately,
2418 * other than kicking ourselves if we are running.
2419 * It will either never be noticed, or noticed very soon.
2422 if (TD_IS_RUNNING(td) && td != curthread)
2434 sig_suspend_threads(struct thread *td, struct proc *p, int sending)
2438 PROC_LOCK_ASSERT(p, MA_OWNED);
2439 PROC_SLOCK_ASSERT(p, MA_OWNED);
2441 FOREACH_THREAD_IN_PROC(p, td2) {
2443 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK;
2444 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) &&
2445 (td2->td_flags & TDF_SINTR)) {
2446 if (td2->td_flags & TDF_SBDRY) {
2448 * Once a thread is asleep with
2449 * TDF_SBDRY set, it should never
2450 * become suspended due to this check.
2452 KASSERT(!TD_IS_SUSPENDED(td2),
2453 ("thread with deferred stops suspended"));
2454 } else if (!TD_IS_SUSPENDED(td2)) {
2455 thread_suspend_one(td2);
2457 } else if (!TD_IS_SUSPENDED(td2)) {
2458 if (sending || td != td2)
2459 td2->td_flags |= TDF_ASTPENDING;
2461 if (TD_IS_RUNNING(td2) && td2 != td)
2462 forward_signal(td2);
2470 ptracestop(struct thread *td, int sig)
2472 struct proc *p = td->td_proc;
2474 PROC_LOCK_ASSERT(p, MA_OWNED);
2475 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process"));
2476 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
2477 &p->p_mtx.lock_object, "Stopping for traced signal");
2479 td->td_dbgflags |= TDB_XSIG;
2481 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d",
2482 td->td_tid, p->p_pid, td->td_dbgflags, sig);
2484 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) {
2485 if (p->p_flag & P_SINGLE_EXIT) {
2486 td->td_dbgflags &= ~TDB_XSIG;
2491 * Just make wait() to work, the last stopped thread
2496 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE);
2497 sig_suspend_threads(td, p, 0);
2498 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) {
2499 td->td_dbgflags &= ~TDB_STOPATFORK;
2500 cv_broadcast(&p->p_dbgwait);
2503 thread_suspend_switch(td, p);
2504 if (p->p_xthread == td)
2505 p->p_xthread = NULL;
2506 if (!(p->p_flag & P_TRACED))
2508 if (td->td_dbgflags & TDB_SUSPEND) {
2509 if (p->p_flag & P_SINGLE_EXIT)
2515 return (td->td_xsig);
2519 reschedule_signals(struct proc *p, sigset_t block, int flags)
2525 PROC_LOCK_ASSERT(p, MA_OWNED);
2527 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ?
2528 MA_OWNED : MA_NOTOWNED);
2529 if (SIGISEMPTY(p->p_siglist))
2531 SIGSETAND(block, p->p_siglist);
2532 while ((sig = sig_ffs(&block)) != 0) {
2533 SIGDELSET(block, sig);
2534 td = sigtd(p, sig, 0);
2536 if (!(flags & SIGPROCMASK_PS_LOCKED))
2537 mtx_lock(&ps->ps_mtx);
2538 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig))
2539 tdsigwakeup(td, sig, SIG_CATCH,
2540 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR :
2542 if (!(flags & SIGPROCMASK_PS_LOCKED))
2543 mtx_unlock(&ps->ps_mtx);
2548 tdsigcleanup(struct thread *td)
2554 PROC_LOCK_ASSERT(p, MA_OWNED);
2556 sigqueue_flush(&td->td_sigqueue);
2557 if (p->p_numthreads == 1)
2561 * Since we cannot handle signals, notify signal post code
2562 * about this by filling the sigmask.
2564 * Also, if needed, wake up thread(s) that do not block the
2565 * same signals as the exiting thread, since the thread might
2566 * have been selected for delivery and woken up.
2568 SIGFILLSET(unblocked);
2569 SIGSETNAND(unblocked, td->td_sigmask);
2570 SIGFILLSET(td->td_sigmask);
2571 reschedule_signals(p, unblocked, 0);
2576 * Defer the delivery of SIGSTOP for the current thread. Returns true
2577 * if stops were deferred and false if they were already deferred.
2585 if (td->td_flags & TDF_SBDRY)
2588 td->td_flags |= TDF_SBDRY;
2594 * Permit the delivery of SIGSTOP for the current thread. This does
2595 * not immediately suspend if a stop was posted. Instead, the thread
2596 * will suspend either via ast() or a subsequent interruptible sleep.
2606 prev = (td->td_flags & TDF_SBDRY) != 0;
2607 td->td_flags &= ~TDF_SBDRY;
2613 * If the current process has received a signal (should be caught or cause
2614 * termination, should interrupt current syscall), return the signal number.
2615 * Stop signals with default action are processed immediately, then cleared;
2616 * they aren't returned. This is checked after each entry to the system for
2617 * a syscall or trap (though this can usually be done without calling issignal
2618 * by checking the pending signal masks in cursig.) The normal call
2621 * while (sig = cursig(curthread))
2625 issignal(struct thread *td)
2629 struct sigqueue *queue;
2630 sigset_t sigpending;
2631 int sig, prop, newsig;
2635 mtx_assert(&ps->ps_mtx, MA_OWNED);
2636 PROC_LOCK_ASSERT(p, MA_OWNED);
2638 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
2640 sigpending = td->td_sigqueue.sq_signals;
2641 SIGSETOR(sigpending, p->p_sigqueue.sq_signals);
2642 SIGSETNAND(sigpending, td->td_sigmask);
2644 if (p->p_flag & P_PPWAIT || td->td_flags & TDF_SBDRY)
2645 SIG_STOPSIGMASK(sigpending);
2646 if (SIGISEMPTY(sigpending)) /* no signal to send */
2648 sig = sig_ffs(&sigpending);
2650 if (p->p_stops & S_SIG) {
2651 mtx_unlock(&ps->ps_mtx);
2652 stopevent(p, S_SIG, sig);
2653 mtx_lock(&ps->ps_mtx);
2657 * We should see pending but ignored signals
2658 * only if P_TRACED was on when they were posted.
2660 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) {
2661 sigqueue_delete(&td->td_sigqueue, sig);
2662 sigqueue_delete(&p->p_sigqueue, sig);
2665 if (p->p_flag & P_TRACED && (p->p_flag & P_PPTRACE) == 0) {
2667 * If traced, always stop.
2668 * Remove old signal from queue before the stop.
2669 * XXX shrug off debugger, it causes siginfo to
2672 queue = &td->td_sigqueue;
2673 td->td_dbgksi.ksi_signo = 0;
2674 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) {
2675 queue = &p->p_sigqueue;
2676 sigqueue_get(queue, sig, &td->td_dbgksi);
2679 mtx_unlock(&ps->ps_mtx);
2680 newsig = ptracestop(td, sig);
2681 mtx_lock(&ps->ps_mtx);
2683 if (sig != newsig) {
2686 * If parent wants us to take the signal,
2687 * then it will leave it in p->p_xstat;
2688 * otherwise we just look for signals again.
2695 * Put the new signal into td_sigqueue. If the
2696 * signal is being masked, look for other
2699 sigqueue_add(queue, sig, NULL);
2700 if (SIGISMEMBER(td->td_sigmask, sig))
2704 if (td->td_dbgksi.ksi_signo != 0) {
2705 td->td_dbgksi.ksi_flags |= KSI_HEAD;
2706 if (sigqueue_add(&td->td_sigqueue, sig,
2707 &td->td_dbgksi) != 0)
2708 td->td_dbgksi.ksi_signo = 0;
2710 if (td->td_dbgksi.ksi_signo == 0)
2711 sigqueue_add(&td->td_sigqueue, sig,
2716 * If the traced bit got turned off, go back up
2717 * to the top to rescan signals. This ensures
2718 * that p_sig* and p_sigact are consistent.
2720 if ((p->p_flag & P_TRACED) == 0)
2724 prop = sigprop(sig);
2727 * Decide whether the signal should be returned.
2728 * Return the signal's number, or fall through
2729 * to clear it from the pending mask.
2731 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
2733 case (intptr_t)SIG_DFL:
2735 * Don't take default actions on system processes.
2737 if (p->p_pid <= 1) {
2740 * Are you sure you want to ignore SIGSEGV
2743 printf("Process (pid %lu) got signal %d\n",
2744 (u_long)p->p_pid, sig);
2746 break; /* == ignore */
2749 * If there is a pending stop signal to process
2750 * with default action, stop here,
2751 * then clear the signal. However,
2752 * if process is member of an orphaned
2753 * process group, ignore tty stop signals.
2755 if (prop & SA_STOP) {
2756 if (p->p_flag & (P_TRACED|P_WEXIT) ||
2757 (p->p_pgrp->pg_jobc == 0 &&
2759 break; /* == ignore */
2760 mtx_unlock(&ps->ps_mtx);
2761 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
2762 &p->p_mtx.lock_object, "Catching SIGSTOP");
2763 p->p_flag |= P_STOPPED_SIG;
2766 sig_suspend_threads(td, p, 0);
2767 thread_suspend_switch(td, p);
2769 mtx_lock(&ps->ps_mtx);
2771 } else if (prop & SA_IGNORE) {
2773 * Except for SIGCONT, shouldn't get here.
2774 * Default action is to ignore; drop it.
2776 break; /* == ignore */
2781 case (intptr_t)SIG_IGN:
2783 * Masking above should prevent us ever trying
2784 * to take action on an ignored signal other
2785 * than SIGCONT, unless process is traced.
2787 if ((prop & SA_CONT) == 0 &&
2788 (p->p_flag & P_TRACED) == 0)
2789 printf("issignal\n");
2790 break; /* == ignore */
2794 * This signal has an action, let
2795 * postsig() process it.
2799 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */
2800 sigqueue_delete(&p->p_sigqueue, sig);
2806 thread_stopped(struct proc *p)
2810 PROC_LOCK_ASSERT(p, MA_OWNED);
2811 PROC_SLOCK_ASSERT(p, MA_OWNED);
2815 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) {
2817 p->p_flag &= ~P_WAITED;
2818 PROC_LOCK(p->p_pptr);
2819 childproc_stopped(p, (p->p_flag & P_TRACED) ?
2820 CLD_TRAPPED : CLD_STOPPED);
2821 PROC_UNLOCK(p->p_pptr);
2827 * Take the action for the specified signal
2828 * from the current set of pending signals.
2834 struct thread *td = curthread;
2835 register struct proc *p = td->td_proc;
2839 sigset_t returnmask;
2841 KASSERT(sig != 0, ("postsig"));
2843 PROC_LOCK_ASSERT(p, MA_OWNED);
2845 mtx_assert(&ps->ps_mtx, MA_OWNED);
2846 ksiginfo_init(&ksi);
2847 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 &&
2848 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0)
2850 ksi.ksi_signo = sig;
2851 if (ksi.ksi_code == SI_TIMER)
2852 itimer_accept(p, ksi.ksi_timerid, &ksi);
2853 action = ps->ps_sigact[_SIG_IDX(sig)];
2855 if (KTRPOINT(td, KTR_PSIG))
2856 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ?
2857 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code);
2859 if (p->p_stops & S_SIG) {
2860 mtx_unlock(&ps->ps_mtx);
2861 stopevent(p, S_SIG, sig);
2862 mtx_lock(&ps->ps_mtx);
2865 if (action == SIG_DFL) {
2867 * Default action, where the default is to kill
2868 * the process. (Other cases were ignored above.)
2870 mtx_unlock(&ps->ps_mtx);
2875 * If we get here, the signal must be caught.
2877 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig),
2878 ("postsig action"));
2880 * Set the new mask value and also defer further
2881 * occurrences of this signal.
2883 * Special case: user has done a sigsuspend. Here the
2884 * current mask is not of interest, but rather the
2885 * mask from before the sigsuspend is what we want
2886 * restored after the signal processing is completed.
2888 if (td->td_pflags & TDP_OLDMASK) {
2889 returnmask = td->td_oldsigmask;
2890 td->td_pflags &= ~TDP_OLDMASK;
2892 returnmask = td->td_sigmask;
2894 if (p->p_sig == sig) {
2898 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask);
2899 postsig_done(sig, td, ps);
2905 * Kill the current process for stated reason.
2913 PROC_LOCK_ASSERT(p, MA_OWNED);
2914 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid,
2916 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid,
2917 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why);
2918 p->p_flag |= P_WKILLED;
2919 kern_psignal(p, SIGKILL);
2923 * Force the current process to exit with the specified signal, dumping core
2924 * if appropriate. We bypass the normal tests for masked and caught signals,
2925 * allowing unrecoverable failures to terminate the process without changing
2926 * signal state. Mark the accounting record with the signal termination.
2927 * If dumping core, save the signal number for the debugger. Calls exit and
2935 struct proc *p = td->td_proc;
2937 PROC_LOCK_ASSERT(p, MA_OWNED);
2938 p->p_acflag |= AXSIG;
2940 * We must be single-threading to generate a core dump. This
2941 * ensures that the registers in the core file are up-to-date.
2942 * Also, the ELF dump handler assumes that the thread list doesn't
2943 * change out from under it.
2945 * XXX If another thread attempts to single-thread before us
2946 * (e.g. via fork()), we won't get a dump at all.
2948 if ((sigprop(sig) & SA_CORE) && thread_single(p, SINGLE_NO_EXIT) == 0) {
2951 * Log signals which would cause core dumps
2952 * (Log as LOG_INFO to appease those who don't want
2954 * XXX : Todo, as well as euid, write out ruid too
2955 * Note that coredump() drops proc lock.
2957 if (coredump(td) == 0)
2959 if (kern_logsigexit)
2961 "pid %d (%s), uid %d: exited on signal %d%s\n",
2962 p->p_pid, p->p_comm,
2963 td->td_ucred ? td->td_ucred->cr_uid : -1,
2965 sig & WCOREFLAG ? " (core dumped)" : "");
2968 exit1(td, W_EXITCODE(0, sig));
2973 * Send queued SIGCHLD to parent when child process's state
2977 sigparent(struct proc *p, int reason, int status)
2979 PROC_LOCK_ASSERT(p, MA_OWNED);
2980 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
2982 if (p->p_ksi != NULL) {
2983 p->p_ksi->ksi_signo = SIGCHLD;
2984 p->p_ksi->ksi_code = reason;
2985 p->p_ksi->ksi_status = status;
2986 p->p_ksi->ksi_pid = p->p_pid;
2987 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid;
2988 if (KSI_ONQ(p->p_ksi))
2991 pksignal(p->p_pptr, SIGCHLD, p->p_ksi);
2995 childproc_jobstate(struct proc *p, int reason, int sig)
2999 PROC_LOCK_ASSERT(p, MA_OWNED);
3000 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
3003 * Wake up parent sleeping in kern_wait(), also send
3004 * SIGCHLD to parent, but SIGCHLD does not guarantee
3005 * that parent will awake, because parent may masked
3008 p->p_pptr->p_flag |= P_STATCHILD;
3011 ps = p->p_pptr->p_sigacts;
3012 mtx_lock(&ps->ps_mtx);
3013 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) {
3014 mtx_unlock(&ps->ps_mtx);
3015 sigparent(p, reason, sig);
3017 mtx_unlock(&ps->ps_mtx);
3021 childproc_stopped(struct proc *p, int reason)
3023 /* p_xstat is a plain signal number, not a full wait() status here. */
3024 childproc_jobstate(p, reason, p->p_xstat);
3028 childproc_continued(struct proc *p)
3030 childproc_jobstate(p, CLD_CONTINUED, SIGCONT);
3034 childproc_exited(struct proc *p)
3037 int xstat = p->p_xstat; /* convert to int */
3040 if (WCOREDUMP(xstat))
3041 reason = CLD_DUMPED, status = WTERMSIG(xstat);
3042 else if (WIFSIGNALED(xstat))
3043 reason = CLD_KILLED, status = WTERMSIG(xstat);
3045 reason = CLD_EXITED, status = WEXITSTATUS(xstat);
3047 * XXX avoid calling wakeup(p->p_pptr), the work is
3050 sigparent(p, reason, status);
3054 * We only have 1 character for the core count in the format
3055 * string, so the range will be 0-9
3057 #define MAX_NUM_CORES 10
3058 static int num_cores = 5;
3061 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS)
3066 new_val = num_cores;
3067 error = sysctl_handle_int(oidp, &new_val, 0, req);
3068 if (error != 0 || req->newptr == NULL)
3070 if (new_val > MAX_NUM_CORES)
3071 new_val = MAX_NUM_CORES;
3074 num_cores = new_val;
3077 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW,
3078 0, sizeof(int), sysctl_debug_num_cores_check, "I", "");
3080 #define GZ_SUFFIX ".gz"
3083 static int compress_user_cores = 1;
3084 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RWTUN,
3085 &compress_user_cores, 0, "Compression of user corefiles");
3087 int compress_user_cores_gzlevel = 6;
3088 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RWTUN,
3089 &compress_user_cores_gzlevel, 0, "Corefile gzip compression level");
3091 static int compress_user_cores = 0;
3095 * Protect the access to corefilename[] by allproc_lock.
3097 #define corefilename_lock allproc_lock
3099 static char corefilename[MAXPATHLEN] = {"%N.core"};
3102 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS)
3106 sx_xlock(&corefilename_lock);
3107 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename),
3109 sx_xunlock(&corefilename_lock);
3113 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RWTUN |
3114 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A",
3115 "Process corefile name format string");
3118 * corefile_open(comm, uid, pid, td, compress, vpp, namep)
3119 * Expand the name described in corefilename, using name, uid, and pid
3120 * and open/create core file.
3121 * corefilename is a printf-like string, with three format specifiers:
3122 * %N name of process ("name")
3123 * %P process id (pid)
3125 * For example, "%N.core" is the default; they can be disabled completely
3126 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
3127 * This is controlled by the sysctl variable kern.corefile (see above).
3130 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td,
3131 int compress, struct vnode **vpp, char **namep)
3133 struct nameidata nd;
3136 char *hostname, *name;
3137 int indexpos, i, error, cmode, flags, oflags;
3140 format = corefilename;
3141 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO);
3143 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN);
3144 sx_slock(&corefilename_lock);
3145 for (i = 0; format[i] != '\0'; i++) {
3146 switch (format[i]) {
3147 case '%': /* Format character */
3149 switch (format[i]) {
3151 sbuf_putc(&sb, '%');
3153 case 'H': /* hostname */
3154 if (hostname == NULL) {
3155 hostname = malloc(MAXHOSTNAMELEN,
3158 getcredhostname(td->td_ucred, hostname,
3160 sbuf_printf(&sb, "%s", hostname);
3162 case 'I': /* autoincrementing index */
3163 sbuf_printf(&sb, "0");
3164 indexpos = sbuf_len(&sb) - 1;
3166 case 'N': /* process name */
3167 sbuf_printf(&sb, "%s", comm);
3169 case 'P': /* process id */
3170 sbuf_printf(&sb, "%u", pid);
3172 case 'U': /* user id */
3173 sbuf_printf(&sb, "%u", uid);
3177 "Unknown format character %c in "
3178 "corename `%s'\n", format[i], format);
3183 sbuf_putc(&sb, format[i]);
3187 sx_sunlock(&corefilename_lock);
3188 free(hostname, M_TEMP);
3190 sbuf_printf(&sb, GZ_SUFFIX);
3191 if (sbuf_error(&sb) != 0) {
3192 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too "
3193 "long\n", (long)pid, comm, (u_long)uid);
3201 cmode = S_IRUSR | S_IWUSR;
3202 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE |
3203 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0);
3206 * If the core format has a %I in it, then we need to check
3207 * for existing corefiles before returning a name.
3208 * To do this we iterate over 0..num_cores to find a
3209 * non-existing core file name to use.
3211 if (indexpos != -1) {
3212 for (i = 0; i < num_cores; i++) {
3213 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW;
3214 name[indexpos] = '0' + i;
3215 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td);
3216 error = vn_open_cred(&nd, &flags, cmode, oflags,
3217 td->td_ucred, NULL);
3219 if (error == EEXIST)
3222 "pid %d (%s), uid (%u): Path `%s' failed "
3223 "on initial open test, error = %d\n",
3224 pid, comm, uid, name, error);
3230 flags = O_CREAT | FWRITE | O_NOFOLLOW;
3231 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td);
3232 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL);
3236 audit_proc_coredump(td, name, error);
3241 NDFREE(&nd, NDF_ONLY_PNBUF);
3248 coredump_sanitise_path(const char *path)
3253 * Only send a subset of ASCII to devd(8) because it
3254 * might pass these strings to sh -c.
3256 for (i = 0; path[i]; i++)
3257 if (!(isalpha(path[i]) || isdigit(path[i])) &&
3258 path[i] != '/' && path[i] != '.' &&
3266 * Dump a process' core. The main routine does some
3267 * policy checking, and creates the name of the coredump;
3268 * then it passes on a vnode and a size limit to the process-specific
3269 * coredump routine if there is one; if there _is not_ one, it returns
3270 * ENOSYS; otherwise it returns the error from the process-specific routine.
3274 coredump(struct thread *td)
3276 struct proc *p = td->td_proc;
3277 struct ucred *cred = td->td_ucred;
3281 int error, error1, locked;
3282 char *name; /* name of corefile */
3286 char *fullpath, *freepath = NULL;
3288 static const char comm_name[] = "comm=";
3289 static const char core_name[] = "core=";
3291 PROC_LOCK_ASSERT(p, MA_OWNED);
3292 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td);
3293 _STOPEVENT(p, S_CORE, 0);
3295 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) ||
3296 (p->p_flag2 & P2_NOTRACE) != 0) {
3302 * Note that the bulk of limit checking is done after
3303 * the corefile is created. The exception is if the limit
3304 * for corefiles is 0, in which case we don't bother
3305 * creating the corefile at all. This layout means that
3306 * a corefile is truncated instead of not being created,
3307 * if it is larger than the limit.
3309 limit = (off_t)lim_cur(td, RLIMIT_CORE);
3310 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) {
3316 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td,
3317 compress_user_cores, &vp, &name);
3322 * Don't dump to non-regular files or files with links.
3323 * Do not dump into system files.
3325 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 ||
3326 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0) {
3334 /* Postpone other writers, including core dumps of other processes. */
3335 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
3337 lf.l_whence = SEEK_SET;
3340 lf.l_type = F_WRLCK;
3341 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0);
3345 if (set_core_nodump_flag)
3346 vattr.va_flags = UF_NODUMP;
3347 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3348 VOP_SETATTR(vp, &vattr, cred);
3351 p->p_acflag |= ACORE;
3354 if (p->p_sysent->sv_coredump != NULL) {
3355 error = p->p_sysent->sv_coredump(td, vp, limit,
3356 compress_user_cores ? IMGACT_CORE_COMPRESS : 0);
3362 lf.l_type = F_UNLCK;
3363 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
3365 vn_rangelock_unlock(vp, rl_cookie);
3368 * Notify the userland helper that a process triggered a core dump.
3369 * This allows the helper to run an automated debugging session.
3371 if (error != 0 || coredump_devctl == 0)
3373 len = MAXPATHLEN * 2 + sizeof(comm_name) - 1 +
3374 sizeof(' ') + sizeof(core_name) - 1;
3375 data = malloc(len, M_TEMP, M_WAITOK);
3376 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0)
3378 if (!coredump_sanitise_path(fullpath))
3380 snprintf(data, len, "%s%s ", comm_name, fullpath);
3381 free(freepath, M_TEMP);
3383 if (vn_fullpath_global(td, vp, &fullpath, &freepath) != 0)
3385 if (!coredump_sanitise_path(fullpath))
3387 strlcat(data, core_name, len);
3388 strlcat(data, fullpath, len);
3389 devctl_notify("kernel", "signal", "coredump", data);
3391 error1 = vn_close(vp, FWRITE, cred, td);
3395 audit_proc_coredump(td, name, error);
3397 free(freepath, M_TEMP);
3404 * Nonexistent system call-- signal process (may want to handle it). Flag
3405 * error in case process won't see signal immediately (blocked or ignored).
3407 #ifndef _SYS_SYSPROTO_H_
3416 struct nosys_args *args;
3418 struct proc *p = td->td_proc;
3421 tdsignal(td, SIGSYS);
3427 * Send a SIGIO or SIGURG signal to a process or process group using stored
3428 * credentials rather than those of the current process.
3431 pgsigio(sigiop, sig, checkctty)
3432 struct sigio **sigiop;
3436 struct sigio *sigio;
3438 ksiginfo_init(&ksi);
3439 ksi.ksi_signo = sig;
3440 ksi.ksi_code = SI_KERNEL;
3444 if (sigio == NULL) {
3448 if (sigio->sio_pgid > 0) {
3449 PROC_LOCK(sigio->sio_proc);
3450 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred))
3451 kern_psignal(sigio->sio_proc, sig);
3452 PROC_UNLOCK(sigio->sio_proc);
3453 } else if (sigio->sio_pgid < 0) {
3456 PGRP_LOCK(sigio->sio_pgrp);
3457 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
3459 if (p->p_state == PRS_NORMAL &&
3460 CANSIGIO(sigio->sio_ucred, p->p_ucred) &&
3461 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
3462 kern_psignal(p, sig);
3465 PGRP_UNLOCK(sigio->sio_pgrp);
3471 filt_sigattach(struct knote *kn)
3473 struct proc *p = curproc;
3475 kn->kn_ptr.p_proc = p;
3476 kn->kn_flags |= EV_CLEAR; /* automatically set */
3478 knlist_add(&p->p_klist, kn, 0);
3484 filt_sigdetach(struct knote *kn)
3486 struct proc *p = kn->kn_ptr.p_proc;
3488 knlist_remove(&p->p_klist, kn, 0);
3492 * signal knotes are shared with proc knotes, so we apply a mask to
3493 * the hint in order to differentiate them from process hints. This
3494 * could be avoided by using a signal-specific knote list, but probably
3495 * isn't worth the trouble.
3498 filt_signal(struct knote *kn, long hint)
3501 if (hint & NOTE_SIGNAL) {
3502 hint &= ~NOTE_SIGNAL;
3504 if (kn->kn_id == hint)
3507 return (kn->kn_data != 0);
3515 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO);
3516 refcount_init(&ps->ps_refcnt, 1);
3517 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF);
3522 sigacts_free(struct sigacts *ps)
3525 if (refcount_release(&ps->ps_refcnt) == 0)
3527 mtx_destroy(&ps->ps_mtx);
3528 free(ps, M_SUBPROC);
3532 sigacts_hold(struct sigacts *ps)
3535 refcount_acquire(&ps->ps_refcnt);
3540 sigacts_copy(struct sigacts *dest, struct sigacts *src)
3543 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest"));
3544 mtx_lock(&src->ps_mtx);
3545 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt));
3546 mtx_unlock(&src->ps_mtx);
3550 sigacts_shared(struct sigacts *ps)
3553 return (ps->ps_refcnt > 1);