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.
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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
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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
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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"
41 #include "opt_ktrace.h"
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/signalvar.h>
47 #include <sys/vnode.h>
49 #include <sys/capsicum.h>
50 #include <sys/condvar.h>
51 #include <sys/event.h>
52 #include <sys/fcntl.h>
53 #include <sys/imgact.h>
54 #include <sys/kernel.h>
56 #include <sys/ktrace.h>
58 #include <sys/malloc.h>
59 #include <sys/mutex.h>
60 #include <sys/refcount.h>
61 #include <sys/namei.h>
63 #include <sys/procdesc.h>
64 #include <sys/posix4.h>
65 #include <sys/pioctl.h>
66 #include <sys/racct.h>
67 #include <sys/resourcevar.h>
70 #include <sys/sleepqueue.h>
74 #include <sys/syscallsubr.h>
75 #include <sys/sysctl.h>
76 #include <sys/sysent.h>
77 #include <sys/syslog.h>
78 #include <sys/sysproto.h>
79 #include <sys/timers.h>
80 #include <sys/unistd.h>
83 #include <vm/vm_extern.h>
88 #include <machine/cpu.h>
90 #include <security/audit/audit.h>
92 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */
94 SDT_PROVIDER_DECLARE(proc);
95 SDT_PROBE_DEFINE3(proc, kernel, , signal__send, "struct thread *",
96 "struct proc *", "int");
97 SDT_PROBE_DEFINE2(proc, kernel, , signal__clear, "int",
99 SDT_PROBE_DEFINE3(proc, kernel, , signal__discard,
100 "struct thread *", "struct proc *", "int");
102 static int coredump(struct thread *);
103 static int killpg1(struct thread *td, int sig, int pgid, int all,
105 static int issignal(struct thread *td);
106 static int sigprop(int sig);
107 static void tdsigwakeup(struct thread *, int, sig_t, int);
108 static void sig_suspend_threads(struct thread *, struct proc *, int);
109 static int filt_sigattach(struct knote *kn);
110 static void filt_sigdetach(struct knote *kn);
111 static int filt_signal(struct knote *kn, long hint);
112 static struct thread *sigtd(struct proc *p, int sig, int prop);
113 static void sigqueue_start(void);
115 static uma_zone_t ksiginfo_zone = NULL;
116 struct filterops sig_filtops = {
118 .f_attach = filt_sigattach,
119 .f_detach = filt_sigdetach,
120 .f_event = filt_signal,
123 static int kern_logsigexit = 1;
124 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
126 "Log processes quitting on abnormal signals to syslog(3)");
128 static int kern_forcesigexit = 1;
129 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW,
130 &kern_forcesigexit, 0, "Force trap signal to be handled");
132 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0,
133 "POSIX real time signal");
135 static int max_pending_per_proc = 128;
136 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW,
137 &max_pending_per_proc, 0, "Max pending signals per proc");
139 static int preallocate_siginfo = 1024;
140 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN,
141 &preallocate_siginfo, 0, "Preallocated signal memory size");
143 static int signal_overflow = 0;
144 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD,
145 &signal_overflow, 0, "Number of signals overflew");
147 static int signal_alloc_fail = 0;
148 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD,
149 &signal_alloc_fail, 0, "signals failed to be allocated");
151 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL);
154 * Policy -- Can ucred cr1 send SIGIO to process cr2?
155 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG
156 * in the right situations.
158 #define CANSIGIO(cr1, cr2) \
159 ((cr1)->cr_uid == 0 || \
160 (cr1)->cr_ruid == (cr2)->cr_ruid || \
161 (cr1)->cr_uid == (cr2)->cr_ruid || \
162 (cr1)->cr_ruid == (cr2)->cr_uid || \
163 (cr1)->cr_uid == (cr2)->cr_uid)
165 static int sugid_coredump;
166 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN,
167 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core");
169 static int capmode_coredump;
170 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN,
171 &capmode_coredump, 0, "Allow processes in capability mode to dump core");
173 static int do_coredump = 1;
174 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
175 &do_coredump, 0, "Enable/Disable coredumps");
177 static int set_core_nodump_flag = 0;
178 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag,
179 0, "Enable setting the NODUMP flag on coredump files");
182 * Signal properties and actions.
183 * The array below categorizes the signals and their default actions
184 * according to the following properties:
186 #define SA_KILL 0x01 /* terminates process by default */
187 #define SA_CORE 0x02 /* ditto and coredumps */
188 #define SA_STOP 0x04 /* suspend process */
189 #define SA_TTYSTOP 0x08 /* ditto, from tty */
190 #define SA_IGNORE 0x10 /* ignore by default */
191 #define SA_CONT 0x20 /* continue if suspended */
192 #define SA_CANTMASK 0x40 /* non-maskable, catchable */
194 static int sigproptbl[NSIG] = {
195 SA_KILL, /* SIGHUP */
196 SA_KILL, /* SIGINT */
197 SA_KILL|SA_CORE, /* SIGQUIT */
198 SA_KILL|SA_CORE, /* SIGILL */
199 SA_KILL|SA_CORE, /* SIGTRAP */
200 SA_KILL|SA_CORE, /* SIGABRT */
201 SA_KILL|SA_CORE, /* SIGEMT */
202 SA_KILL|SA_CORE, /* SIGFPE */
203 SA_KILL, /* SIGKILL */
204 SA_KILL|SA_CORE, /* SIGBUS */
205 SA_KILL|SA_CORE, /* SIGSEGV */
206 SA_KILL|SA_CORE, /* SIGSYS */
207 SA_KILL, /* SIGPIPE */
208 SA_KILL, /* SIGALRM */
209 SA_KILL, /* SIGTERM */
210 SA_IGNORE, /* SIGURG */
211 SA_STOP, /* SIGSTOP */
212 SA_STOP|SA_TTYSTOP, /* SIGTSTP */
213 SA_IGNORE|SA_CONT, /* SIGCONT */
214 SA_IGNORE, /* SIGCHLD */
215 SA_STOP|SA_TTYSTOP, /* SIGTTIN */
216 SA_STOP|SA_TTYSTOP, /* SIGTTOU */
217 SA_IGNORE, /* SIGIO */
218 SA_KILL, /* SIGXCPU */
219 SA_KILL, /* SIGXFSZ */
220 SA_KILL, /* SIGVTALRM */
221 SA_KILL, /* SIGPROF */
222 SA_IGNORE, /* SIGWINCH */
223 SA_IGNORE, /* SIGINFO */
224 SA_KILL, /* SIGUSR1 */
225 SA_KILL, /* SIGUSR2 */
228 static void reschedule_signals(struct proc *p, sigset_t block, int flags);
233 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t),
234 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
235 uma_prealloc(ksiginfo_zone, preallocate_siginfo);
236 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS);
237 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1);
238 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc);
242 ksiginfo_alloc(int wait)
249 if (ksiginfo_zone != NULL)
250 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags));
255 ksiginfo_free(ksiginfo_t *ksi)
257 uma_zfree(ksiginfo_zone, ksi);
261 ksiginfo_tryfree(ksiginfo_t *ksi)
263 if (!(ksi->ksi_flags & KSI_EXT)) {
264 uma_zfree(ksiginfo_zone, ksi);
271 sigqueue_init(sigqueue_t *list, struct proc *p)
273 SIGEMPTYSET(list->sq_signals);
274 SIGEMPTYSET(list->sq_kill);
275 TAILQ_INIT(&list->sq_list);
277 list->sq_flags = SQ_INIT;
281 * Get a signal's ksiginfo.
283 * 0 - signal not found
284 * others - signal number
287 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si)
289 struct proc *p = sq->sq_proc;
290 struct ksiginfo *ksi, *next;
293 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
295 if (!SIGISMEMBER(sq->sq_signals, signo))
298 if (SIGISMEMBER(sq->sq_kill, signo)) {
300 SIGDELSET(sq->sq_kill, signo);
303 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
304 if (ksi->ksi_signo == signo) {
306 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
307 ksi->ksi_sigq = NULL;
308 ksiginfo_copy(ksi, si);
309 if (ksiginfo_tryfree(ksi) && p != NULL)
318 SIGDELSET(sq->sq_signals, signo);
319 si->ksi_signo = signo;
324 sigqueue_take(ksiginfo_t *ksi)
330 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL)
334 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
335 ksi->ksi_sigq = NULL;
336 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL)
339 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL;
340 kp = TAILQ_NEXT(kp, ksi_link)) {
341 if (kp->ksi_signo == ksi->ksi_signo)
344 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo))
345 SIGDELSET(sq->sq_signals, ksi->ksi_signo);
349 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si)
351 struct proc *p = sq->sq_proc;
352 struct ksiginfo *ksi;
355 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
357 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) {
358 SIGADDSET(sq->sq_kill, signo);
362 /* directly insert the ksi, don't copy it */
363 if (si->ksi_flags & KSI_INS) {
364 if (si->ksi_flags & KSI_HEAD)
365 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link);
367 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link);
372 if (__predict_false(ksiginfo_zone == NULL)) {
373 SIGADDSET(sq->sq_kill, signo);
377 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) {
380 } else if ((ksi = ksiginfo_alloc(0)) == NULL) {
386 ksiginfo_copy(si, ksi);
387 ksi->ksi_signo = signo;
388 if (si->ksi_flags & KSI_HEAD)
389 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link);
391 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link);
395 if ((si->ksi_flags & KSI_TRAP) != 0 ||
396 (si->ksi_flags & KSI_SIGQ) == 0) {
398 SIGADDSET(sq->sq_kill, signo);
407 SIGADDSET(sq->sq_signals, signo);
412 sigqueue_flush(sigqueue_t *sq)
414 struct proc *p = sq->sq_proc;
417 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
420 PROC_LOCK_ASSERT(p, MA_OWNED);
422 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) {
423 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
424 ksi->ksi_sigq = NULL;
425 if (ksiginfo_tryfree(ksi) && p != NULL)
429 SIGEMPTYSET(sq->sq_signals);
430 SIGEMPTYSET(sq->sq_kill);
434 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set)
437 struct proc *p1, *p2;
438 ksiginfo_t *ksi, *next;
440 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited"));
441 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited"));
444 /* Move siginfo to target list */
445 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) {
446 if (SIGISMEMBER(*set, ksi->ksi_signo)) {
447 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link);
450 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link);
457 /* Move pending bits to target list */
459 SIGSETAND(tmp, *set);
460 SIGSETOR(dst->sq_kill, tmp);
461 SIGSETNAND(src->sq_kill, tmp);
463 tmp = src->sq_signals;
464 SIGSETAND(tmp, *set);
465 SIGSETOR(dst->sq_signals, tmp);
466 SIGSETNAND(src->sq_signals, tmp);
471 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo)
476 SIGADDSET(set, signo);
477 sigqueue_move_set(src, dst, &set);
482 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set)
484 struct proc *p = sq->sq_proc;
485 ksiginfo_t *ksi, *next;
487 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited"));
489 /* Remove siginfo queue */
490 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
491 if (SIGISMEMBER(*set, ksi->ksi_signo)) {
492 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
493 ksi->ksi_sigq = NULL;
494 if (ksiginfo_tryfree(ksi) && p != NULL)
498 SIGSETNAND(sq->sq_kill, *set);
499 SIGSETNAND(sq->sq_signals, *set);
503 sigqueue_delete(sigqueue_t *sq, int signo)
508 SIGADDSET(set, signo);
509 sigqueue_delete_set(sq, &set);
512 /* Remove a set of signals for a process */
514 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set)
519 PROC_LOCK_ASSERT(p, MA_OWNED);
521 sigqueue_init(&worklist, NULL);
522 sigqueue_move_set(&p->p_sigqueue, &worklist, set);
524 FOREACH_THREAD_IN_PROC(p, td0)
525 sigqueue_move_set(&td0->td_sigqueue, &worklist, set);
527 sigqueue_flush(&worklist);
531 sigqueue_delete_proc(struct proc *p, int signo)
536 SIGADDSET(set, signo);
537 sigqueue_delete_set_proc(p, &set);
541 sigqueue_delete_stopmask_proc(struct proc *p)
546 SIGADDSET(set, SIGSTOP);
547 SIGADDSET(set, SIGTSTP);
548 SIGADDSET(set, SIGTTIN);
549 SIGADDSET(set, SIGTTOU);
550 sigqueue_delete_set_proc(p, &set);
554 * Determine signal that should be delivered to thread td, the current
555 * thread, 0 if none. If there is a pending stop signal with default
556 * action, the process stops in issignal().
559 cursig(struct thread *td)
561 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
562 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED);
563 THREAD_LOCK_ASSERT(td, MA_NOTOWNED);
564 return (SIGPENDING(td) ? issignal(td) : 0);
568 * Arrange for ast() to handle unmasked pending signals on return to user
569 * mode. This must be called whenever a signal is added to td_sigqueue or
570 * unmasked in td_sigmask.
573 signotify(struct thread *td)
579 PROC_LOCK_ASSERT(p, MA_OWNED);
581 if (SIGPENDING(td)) {
583 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING;
589 sigonstack(size_t sp)
591 struct thread *td = curthread;
593 return ((td->td_pflags & TDP_ALTSTACK) ?
594 #if defined(COMPAT_43)
595 ((td->td_sigstk.ss_size == 0) ?
596 (td->td_sigstk.ss_flags & SS_ONSTACK) :
597 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size))
599 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)
608 if (sig > 0 && sig < NSIG)
609 return (sigproptbl[_SIG_IDX(sig)]);
614 sig_ffs(sigset_t *set)
618 for (i = 0; i < _SIG_WORDS; i++)
620 return (ffs(set->__bits[i]) + (i * 32));
625 sigact_flag_test(struct sigaction *act, int flag)
629 * SA_SIGINFO is reset when signal disposition is set to
630 * ignore or default. Other flags are kept according to user
633 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO ||
634 ((__sighandler_t *)act->sa_sigaction != SIG_IGN &&
635 (__sighandler_t *)act->sa_sigaction != SIG_DFL)));
645 kern_sigaction(td, sig, act, oact, flags)
648 struct sigaction *act, *oact;
652 struct proc *p = td->td_proc;
654 if (!_SIG_VALID(sig))
656 if (act != NULL && (act->sa_flags & ~(SA_ONSTACK | SA_RESTART |
657 SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | SA_NOCLDWAIT |
663 mtx_lock(&ps->ps_mtx);
665 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
667 if (SIGISMEMBER(ps->ps_sigonstack, sig))
668 oact->sa_flags |= SA_ONSTACK;
669 if (!SIGISMEMBER(ps->ps_sigintr, sig))
670 oact->sa_flags |= SA_RESTART;
671 if (SIGISMEMBER(ps->ps_sigreset, sig))
672 oact->sa_flags |= SA_RESETHAND;
673 if (SIGISMEMBER(ps->ps_signodefer, sig))
674 oact->sa_flags |= SA_NODEFER;
675 if (SIGISMEMBER(ps->ps_siginfo, sig)) {
676 oact->sa_flags |= SA_SIGINFO;
678 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)];
680 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
681 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP)
682 oact->sa_flags |= SA_NOCLDSTOP;
683 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT)
684 oact->sa_flags |= SA_NOCLDWAIT;
687 if ((sig == SIGKILL || sig == SIGSTOP) &&
688 act->sa_handler != SIG_DFL) {
689 mtx_unlock(&ps->ps_mtx);
695 * Change setting atomically.
698 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
699 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
700 if (sigact_flag_test(act, SA_SIGINFO)) {
701 ps->ps_sigact[_SIG_IDX(sig)] =
702 (__sighandler_t *)act->sa_sigaction;
703 SIGADDSET(ps->ps_siginfo, sig);
705 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
706 SIGDELSET(ps->ps_siginfo, sig);
708 if (!sigact_flag_test(act, SA_RESTART))
709 SIGADDSET(ps->ps_sigintr, sig);
711 SIGDELSET(ps->ps_sigintr, sig);
712 if (sigact_flag_test(act, SA_ONSTACK))
713 SIGADDSET(ps->ps_sigonstack, sig);
715 SIGDELSET(ps->ps_sigonstack, sig);
716 if (sigact_flag_test(act, SA_RESETHAND))
717 SIGADDSET(ps->ps_sigreset, sig);
719 SIGDELSET(ps->ps_sigreset, sig);
720 if (sigact_flag_test(act, SA_NODEFER))
721 SIGADDSET(ps->ps_signodefer, sig);
723 SIGDELSET(ps->ps_signodefer, sig);
724 if (sig == SIGCHLD) {
725 if (act->sa_flags & SA_NOCLDSTOP)
726 ps->ps_flag |= PS_NOCLDSTOP;
728 ps->ps_flag &= ~PS_NOCLDSTOP;
729 if (act->sa_flags & SA_NOCLDWAIT) {
731 * Paranoia: since SA_NOCLDWAIT is implemented
732 * by reparenting the dying child to PID 1 (and
733 * trust it to reap the zombie), PID 1 itself
734 * is forbidden to set SA_NOCLDWAIT.
737 ps->ps_flag &= ~PS_NOCLDWAIT;
739 ps->ps_flag |= PS_NOCLDWAIT;
741 ps->ps_flag &= ~PS_NOCLDWAIT;
742 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
743 ps->ps_flag |= PS_CLDSIGIGN;
745 ps->ps_flag &= ~PS_CLDSIGIGN;
748 * Set bit in ps_sigignore for signals that are set to SIG_IGN,
749 * and for signals set to SIG_DFL where the default is to
750 * ignore. However, don't put SIGCONT in ps_sigignore, as we
751 * have to restart the process.
753 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
754 (sigprop(sig) & SA_IGNORE &&
755 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
756 /* never to be seen again */
757 sigqueue_delete_proc(p, sig);
759 /* easier in psignal */
760 SIGADDSET(ps->ps_sigignore, sig);
761 SIGDELSET(ps->ps_sigcatch, sig);
763 SIGDELSET(ps->ps_sigignore, sig);
764 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
765 SIGDELSET(ps->ps_sigcatch, sig);
767 SIGADDSET(ps->ps_sigcatch, sig);
769 #ifdef COMPAT_FREEBSD4
770 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
771 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
772 (flags & KSA_FREEBSD4) == 0)
773 SIGDELSET(ps->ps_freebsd4, sig);
775 SIGADDSET(ps->ps_freebsd4, sig);
778 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
779 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
780 (flags & KSA_OSIGSET) == 0)
781 SIGDELSET(ps->ps_osigset, sig);
783 SIGADDSET(ps->ps_osigset, sig);
786 mtx_unlock(&ps->ps_mtx);
791 #ifndef _SYS_SYSPROTO_H_
792 struct sigaction_args {
794 struct sigaction *act;
795 struct sigaction *oact;
799 sys_sigaction(td, uap)
801 register struct sigaction_args *uap;
803 struct sigaction act, oact;
804 register struct sigaction *actp, *oactp;
807 actp = (uap->act != NULL) ? &act : NULL;
808 oactp = (uap->oact != NULL) ? &oact : NULL;
810 error = copyin(uap->act, actp, sizeof(act));
814 error = kern_sigaction(td, uap->sig, actp, oactp, 0);
816 error = copyout(oactp, uap->oact, sizeof(oact));
820 #ifdef COMPAT_FREEBSD4
821 #ifndef _SYS_SYSPROTO_H_
822 struct freebsd4_sigaction_args {
824 struct sigaction *act;
825 struct sigaction *oact;
829 freebsd4_sigaction(td, uap)
831 register struct freebsd4_sigaction_args *uap;
833 struct sigaction act, oact;
834 register struct sigaction *actp, *oactp;
838 actp = (uap->act != NULL) ? &act : NULL;
839 oactp = (uap->oact != NULL) ? &oact : NULL;
841 error = copyin(uap->act, actp, sizeof(act));
845 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4);
847 error = copyout(oactp, uap->oact, sizeof(oact));
850 #endif /* COMAPT_FREEBSD4 */
852 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
853 #ifndef _SYS_SYSPROTO_H_
854 struct osigaction_args {
856 struct osigaction *nsa;
857 struct osigaction *osa;
863 register struct osigaction_args *uap;
865 struct osigaction sa;
866 struct sigaction nsa, osa;
867 register struct sigaction *nsap, *osap;
870 if (uap->signum <= 0 || uap->signum >= ONSIG)
873 nsap = (uap->nsa != NULL) ? &nsa : NULL;
874 osap = (uap->osa != NULL) ? &osa : NULL;
877 error = copyin(uap->nsa, &sa, sizeof(sa));
880 nsap->sa_handler = sa.sa_handler;
881 nsap->sa_flags = sa.sa_flags;
882 OSIG2SIG(sa.sa_mask, nsap->sa_mask);
884 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
885 if (osap && !error) {
886 sa.sa_handler = osap->sa_handler;
887 sa.sa_flags = osap->sa_flags;
888 SIG2OSIG(osap->sa_mask, sa.sa_mask);
889 error = copyout(&sa, uap->osa, sizeof(sa));
894 #if !defined(__i386__)
895 /* Avoid replicating the same stub everywhere */
899 struct osigreturn_args *uap;
902 return (nosys(td, (struct nosys_args *)uap));
905 #endif /* COMPAT_43 */
908 * Initialize signal state for process 0;
909 * set to ignore signals that are ignored by default.
920 mtx_lock(&ps->ps_mtx);
921 for (i = 1; i <= NSIG; i++) {
922 if (sigprop(i) & SA_IGNORE && i != SIGCONT) {
923 SIGADDSET(ps->ps_sigignore, i);
926 mtx_unlock(&ps->ps_mtx);
931 * Reset specified signal to the default disposition.
934 sigdflt(struct sigacts *ps, int sig)
937 mtx_assert(&ps->ps_mtx, MA_OWNED);
938 SIGDELSET(ps->ps_sigcatch, sig);
939 if ((sigprop(sig) & SA_IGNORE) != 0 && sig != SIGCONT)
940 SIGADDSET(ps->ps_sigignore, sig);
941 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
942 SIGDELSET(ps->ps_siginfo, sig);
946 * Reset signals for an exec of the specified process.
949 execsigs(struct proc *p)
956 * Reset caught signals. Held signals remain held
957 * through td_sigmask (unless they were caught,
958 * and are now ignored by default).
960 PROC_LOCK_ASSERT(p, MA_OWNED);
961 td = FIRST_THREAD_IN_PROC(p);
963 mtx_lock(&ps->ps_mtx);
964 while (SIGNOTEMPTY(ps->ps_sigcatch)) {
965 sig = sig_ffs(&ps->ps_sigcatch);
967 if ((sigprop(sig) & SA_IGNORE) != 0)
968 sigqueue_delete_proc(p, sig);
971 * Reset stack state to the user stack.
972 * Clear set of signals caught on the signal stack.
974 td->td_sigstk.ss_flags = SS_DISABLE;
975 td->td_sigstk.ss_size = 0;
976 td->td_sigstk.ss_sp = 0;
977 td->td_pflags &= ~TDP_ALTSTACK;
979 * Reset no zombies if child dies flag as Solaris does.
981 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN);
982 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
983 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL;
984 mtx_unlock(&ps->ps_mtx);
990 * Manipulate signal mask.
993 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset,
996 sigset_t new_block, oset1;
1001 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0)
1002 PROC_LOCK_ASSERT(p, MA_OWNED);
1005 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0
1006 ? MA_OWNED : MA_NOTOWNED);
1008 *oset = td->td_sigmask;
1015 oset1 = td->td_sigmask;
1016 SIGSETOR(td->td_sigmask, *set);
1017 new_block = td->td_sigmask;
1018 SIGSETNAND(new_block, oset1);
1021 SIGSETNAND(td->td_sigmask, *set);
1026 oset1 = td->td_sigmask;
1027 if (flags & SIGPROCMASK_OLD)
1028 SIGSETLO(td->td_sigmask, *set);
1030 td->td_sigmask = *set;
1031 new_block = td->td_sigmask;
1032 SIGSETNAND(new_block, oset1);
1041 * The new_block set contains signals that were not previously
1042 * blocked, but are blocked now.
1044 * In case we block any signal that was not previously blocked
1045 * for td, and process has the signal pending, try to schedule
1046 * signal delivery to some thread that does not block the
1047 * signal, possibly waking it up.
1049 if (p->p_numthreads != 1)
1050 reschedule_signals(p, new_block, flags);
1054 if (!(flags & SIGPROCMASK_PROC_LOCKED))
1059 #ifndef _SYS_SYSPROTO_H_
1060 struct sigprocmask_args {
1062 const sigset_t *set;
1067 sys_sigprocmask(td, uap)
1068 register struct thread *td;
1069 struct sigprocmask_args *uap;
1072 sigset_t *setp, *osetp;
1075 setp = (uap->set != NULL) ? &set : NULL;
1076 osetp = (uap->oset != NULL) ? &oset : NULL;
1078 error = copyin(uap->set, setp, sizeof(set));
1082 error = kern_sigprocmask(td, uap->how, setp, osetp, 0);
1083 if (osetp && !error) {
1084 error = copyout(osetp, uap->oset, sizeof(oset));
1089 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1090 #ifndef _SYS_SYSPROTO_H_
1091 struct osigprocmask_args {
1097 osigprocmask(td, uap)
1098 register struct thread *td;
1099 struct osigprocmask_args *uap;
1104 OSIG2SIG(uap->mask, set);
1105 error = kern_sigprocmask(td, uap->how, &set, &oset, 1);
1106 SIG2OSIG(oset, td->td_retval[0]);
1109 #endif /* COMPAT_43 */
1112 sys_sigwait(struct thread *td, struct sigwait_args *uap)
1118 error = copyin(uap->set, &set, sizeof(set));
1120 td->td_retval[0] = error;
1124 error = kern_sigtimedwait(td, set, &ksi, NULL);
1126 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT)
1128 if (error == ERESTART)
1130 td->td_retval[0] = error;
1134 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo));
1135 td->td_retval[0] = error;
1140 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap)
1143 struct timespec *timeout;
1149 error = copyin(uap->timeout, &ts, sizeof(ts));
1157 error = copyin(uap->set, &set, sizeof(set));
1161 error = kern_sigtimedwait(td, set, &ksi, timeout);
1166 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t));
1169 td->td_retval[0] = ksi.ksi_signo;
1174 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap)
1180 error = copyin(uap->set, &set, sizeof(set));
1184 error = kern_sigtimedwait(td, set, &ksi, NULL);
1189 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t));
1192 td->td_retval[0] = ksi.ksi_signo;
1197 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi,
1198 struct timespec *timeout)
1201 sigset_t saved_mask, new_block;
1203 int error, sig, timo, timevalid = 0;
1204 struct timespec rts, ets, ts;
1212 if (timeout != NULL) {
1213 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) {
1215 getnanouptime(&rts);
1217 timespecadd(&ets, timeout);
1221 /* Some signals can not be waited for. */
1222 SIG_CANTMASK(waitset);
1225 saved_mask = td->td_sigmask;
1226 SIGSETNAND(td->td_sigmask, waitset);
1228 mtx_lock(&ps->ps_mtx);
1230 mtx_unlock(&ps->ps_mtx);
1231 if (sig != 0 && SIGISMEMBER(waitset, sig)) {
1232 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 ||
1233 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) {
1243 * POSIX says this must be checked after looking for pending
1246 if (timeout != NULL) {
1251 getnanouptime(&rts);
1252 if (timespeccmp(&rts, &ets, >=)) {
1257 timespecsub(&ts, &rts);
1258 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1264 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo);
1266 if (timeout != NULL) {
1267 if (error == ERESTART) {
1268 /* Timeout can not be restarted. */
1270 } else if (error == EAGAIN) {
1271 /* We will calculate timeout by ourself. */
1277 new_block = saved_mask;
1278 SIGSETNAND(new_block, td->td_sigmask);
1279 td->td_sigmask = saved_mask;
1281 * Fewer signals can be delivered to us, reschedule signal
1284 if (p->p_numthreads != 1)
1285 reschedule_signals(p, new_block, 0);
1288 SDT_PROBE(proc, kernel, , signal__clear, sig, ksi, 0, 0, 0);
1290 if (ksi->ksi_code == SI_TIMER)
1291 itimer_accept(p, ksi->ksi_timerid, ksi);
1294 if (KTRPOINT(td, KTR_PSIG)) {
1297 mtx_lock(&ps->ps_mtx);
1298 action = ps->ps_sigact[_SIG_IDX(sig)];
1299 mtx_unlock(&ps->ps_mtx);
1300 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code);
1310 #ifndef _SYS_SYSPROTO_H_
1311 struct sigpending_args {
1316 sys_sigpending(td, uap)
1318 struct sigpending_args *uap;
1320 struct proc *p = td->td_proc;
1324 pending = p->p_sigqueue.sq_signals;
1325 SIGSETOR(pending, td->td_sigqueue.sq_signals);
1327 return (copyout(&pending, uap->set, sizeof(sigset_t)));
1330 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1331 #ifndef _SYS_SYSPROTO_H_
1332 struct osigpending_args {
1337 osigpending(td, uap)
1339 struct osigpending_args *uap;
1341 struct proc *p = td->td_proc;
1345 pending = p->p_sigqueue.sq_signals;
1346 SIGSETOR(pending, td->td_sigqueue.sq_signals);
1348 SIG2OSIG(pending, td->td_retval[0]);
1351 #endif /* COMPAT_43 */
1353 #if defined(COMPAT_43)
1355 * Generalized interface signal handler, 4.3-compatible.
1357 #ifndef _SYS_SYSPROTO_H_
1358 struct osigvec_args {
1368 register struct osigvec_args *uap;
1371 struct sigaction nsa, osa;
1372 register struct sigaction *nsap, *osap;
1375 if (uap->signum <= 0 || uap->signum >= ONSIG)
1377 nsap = (uap->nsv != NULL) ? &nsa : NULL;
1378 osap = (uap->osv != NULL) ? &osa : NULL;
1380 error = copyin(uap->nsv, &vec, sizeof(vec));
1383 nsap->sa_handler = vec.sv_handler;
1384 OSIG2SIG(vec.sv_mask, nsap->sa_mask);
1385 nsap->sa_flags = vec.sv_flags;
1386 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */
1388 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
1389 if (osap && !error) {
1390 vec.sv_handler = osap->sa_handler;
1391 SIG2OSIG(osap->sa_mask, vec.sv_mask);
1392 vec.sv_flags = osap->sa_flags;
1393 vec.sv_flags &= ~SA_NOCLDWAIT;
1394 vec.sv_flags ^= SA_RESTART;
1395 error = copyout(&vec, uap->osv, sizeof(vec));
1400 #ifndef _SYS_SYSPROTO_H_
1401 struct osigblock_args {
1407 register struct thread *td;
1408 struct osigblock_args *uap;
1412 OSIG2SIG(uap->mask, set);
1413 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0);
1414 SIG2OSIG(oset, td->td_retval[0]);
1418 #ifndef _SYS_SYSPROTO_H_
1419 struct osigsetmask_args {
1424 osigsetmask(td, uap)
1426 struct osigsetmask_args *uap;
1430 OSIG2SIG(uap->mask, set);
1431 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0);
1432 SIG2OSIG(oset, td->td_retval[0]);
1435 #endif /* COMPAT_43 */
1438 * Suspend calling thread until signal, providing mask to be set in the
1441 #ifndef _SYS_SYSPROTO_H_
1442 struct sigsuspend_args {
1443 const sigset_t *sigmask;
1448 sys_sigsuspend(td, uap)
1450 struct sigsuspend_args *uap;
1455 error = copyin(uap->sigmask, &mask, sizeof(mask));
1458 return (kern_sigsuspend(td, mask));
1462 kern_sigsuspend(struct thread *td, sigset_t mask)
1464 struct proc *p = td->td_proc;
1468 * When returning from sigsuspend, we want
1469 * the old mask to be restored after the
1470 * signal handler has finished. Thus, we
1471 * save it here and mark the sigacts structure
1475 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask,
1476 SIGPROCMASK_PROC_LOCKED);
1477 td->td_pflags |= TDP_OLDMASK;
1480 * Process signals now. Otherwise, we can get spurious wakeup
1481 * due to signal entered process queue, but delivered to other
1482 * thread. But sigsuspend should return only on signal
1485 (p->p_sysent->sv_set_syscall_retval)(td, EINTR);
1486 for (has_sig = 0; !has_sig;) {
1487 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause",
1490 thread_suspend_check(0);
1491 mtx_lock(&p->p_sigacts->ps_mtx);
1492 while ((sig = cursig(td)) != 0)
1493 has_sig += postsig(sig);
1494 mtx_unlock(&p->p_sigacts->ps_mtx);
1497 td->td_errno = EINTR;
1498 td->td_pflags |= TDP_NERRNO;
1499 return (EJUSTRETURN);
1502 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1504 * Compatibility sigsuspend call for old binaries. Note nonstandard calling
1505 * convention: libc stub passes mask, not pointer, to save a copyin.
1507 #ifndef _SYS_SYSPROTO_H_
1508 struct osigsuspend_args {
1514 osigsuspend(td, uap)
1516 struct osigsuspend_args *uap;
1520 OSIG2SIG(uap->mask, mask);
1521 return (kern_sigsuspend(td, mask));
1523 #endif /* COMPAT_43 */
1525 #if defined(COMPAT_43)
1526 #ifndef _SYS_SYSPROTO_H_
1527 struct osigstack_args {
1528 struct sigstack *nss;
1529 struct sigstack *oss;
1536 register struct osigstack_args *uap;
1538 struct sigstack nss, oss;
1541 if (uap->nss != NULL) {
1542 error = copyin(uap->nss, &nss, sizeof(nss));
1546 oss.ss_sp = td->td_sigstk.ss_sp;
1547 oss.ss_onstack = sigonstack(cpu_getstack(td));
1548 if (uap->nss != NULL) {
1549 td->td_sigstk.ss_sp = nss.ss_sp;
1550 td->td_sigstk.ss_size = 0;
1551 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK;
1552 td->td_pflags |= TDP_ALTSTACK;
1554 if (uap->oss != NULL)
1555 error = copyout(&oss, uap->oss, sizeof(oss));
1559 #endif /* COMPAT_43 */
1561 #ifndef _SYS_SYSPROTO_H_
1562 struct sigaltstack_args {
1569 sys_sigaltstack(td, uap)
1571 register struct sigaltstack_args *uap;
1576 if (uap->ss != NULL) {
1577 error = copyin(uap->ss, &ss, sizeof(ss));
1581 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL,
1582 (uap->oss != NULL) ? &oss : NULL);
1585 if (uap->oss != NULL)
1586 error = copyout(&oss, uap->oss, sizeof(stack_t));
1591 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss)
1593 struct proc *p = td->td_proc;
1596 oonstack = sigonstack(cpu_getstack(td));
1599 *oss = td->td_sigstk;
1600 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK)
1601 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
1607 if ((ss->ss_flags & ~SS_DISABLE) != 0)
1609 if (!(ss->ss_flags & SS_DISABLE)) {
1610 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
1613 td->td_sigstk = *ss;
1614 td->td_pflags |= TDP_ALTSTACK;
1616 td->td_pflags &= ~TDP_ALTSTACK;
1623 * Common code for kill process group/broadcast kill.
1624 * cp is calling process.
1627 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi)
1639 sx_slock(&allproc_lock);
1640 FOREACH_PROC_IN_SYSTEM(p) {
1642 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
1643 p == td->td_proc || p->p_state == PRS_NEW) {
1647 err = p_cansignal(td, p, sig);
1650 pksignal(p, sig, ksi);
1653 else if (ret == ESRCH)
1657 sx_sunlock(&allproc_lock);
1659 sx_slock(&proctree_lock);
1662 * zero pgid means send to my process group.
1664 pgrp = td->td_proc->p_pgrp;
1667 pgrp = pgfind(pgid);
1669 sx_sunlock(&proctree_lock);
1673 sx_sunlock(&proctree_lock);
1674 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
1676 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
1677 p->p_state == PRS_NEW) {
1681 err = p_cansignal(td, p, sig);
1684 pksignal(p, sig, ksi);
1687 else if (ret == ESRCH)
1696 #ifndef _SYS_SYSPROTO_H_
1704 sys_kill(struct thread *td, struct kill_args *uap)
1711 * A process in capability mode can send signals only to himself.
1712 * The main rationale behind this is that abort(3) is implemented as
1713 * kill(getpid(), SIGABRT).
1715 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid)
1718 AUDIT_ARG_SIGNUM(uap->signum);
1719 AUDIT_ARG_PID(uap->pid);
1720 if ((u_int)uap->signum > _SIG_MAXSIG)
1723 ksiginfo_init(&ksi);
1724 ksi.ksi_signo = uap->signum;
1725 ksi.ksi_code = SI_USER;
1726 ksi.ksi_pid = td->td_proc->p_pid;
1727 ksi.ksi_uid = td->td_ucred->cr_ruid;
1730 /* kill single process */
1731 if ((p = pfind(uap->pid)) == NULL) {
1732 if ((p = zpfind(uap->pid)) == NULL)
1735 AUDIT_ARG_PROCESS(p);
1736 error = p_cansignal(td, p, uap->signum);
1737 if (error == 0 && uap->signum)
1738 pksignal(p, uap->signum, &ksi);
1743 case -1: /* broadcast signal */
1744 return (killpg1(td, uap->signum, 0, 1, &ksi));
1745 case 0: /* signal own process group */
1746 return (killpg1(td, uap->signum, 0, 0, &ksi));
1747 default: /* negative explicit process group */
1748 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi));
1756 struct pdkill_args *uap;
1759 cap_rights_t rights;
1762 AUDIT_ARG_SIGNUM(uap->signum);
1763 AUDIT_ARG_FD(uap->fd);
1764 if ((u_int)uap->signum > _SIG_MAXSIG)
1767 error = procdesc_find(td, uap->fd,
1768 cap_rights_init(&rights, CAP_PDKILL), &p);
1771 AUDIT_ARG_PROCESS(p);
1772 error = p_cansignal(td, p, uap->signum);
1773 if (error == 0 && uap->signum)
1774 kern_psignal(p, uap->signum);
1779 #if defined(COMPAT_43)
1780 #ifndef _SYS_SYSPROTO_H_
1781 struct okillpg_args {
1788 okillpg(struct thread *td, struct okillpg_args *uap)
1792 AUDIT_ARG_SIGNUM(uap->signum);
1793 AUDIT_ARG_PID(uap->pgid);
1794 if ((u_int)uap->signum > _SIG_MAXSIG)
1797 ksiginfo_init(&ksi);
1798 ksi.ksi_signo = uap->signum;
1799 ksi.ksi_code = SI_USER;
1800 ksi.ksi_pid = td->td_proc->p_pid;
1801 ksi.ksi_uid = td->td_ucred->cr_ruid;
1802 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi));
1804 #endif /* COMPAT_43 */
1806 #ifndef _SYS_SYSPROTO_H_
1807 struct sigqueue_args {
1810 /* union sigval */ void *value;
1814 sys_sigqueue(struct thread *td, struct sigqueue_args *uap)
1820 if ((u_int)uap->signum > _SIG_MAXSIG)
1824 * Specification says sigqueue can only send signal to
1830 if ((p = pfind(uap->pid)) == NULL) {
1831 if ((p = zpfind(uap->pid)) == NULL)
1834 error = p_cansignal(td, p, uap->signum);
1835 if (error == 0 && uap->signum != 0) {
1836 ksiginfo_init(&ksi);
1837 ksi.ksi_flags = KSI_SIGQ;
1838 ksi.ksi_signo = uap->signum;
1839 ksi.ksi_code = SI_QUEUE;
1840 ksi.ksi_pid = td->td_proc->p_pid;
1841 ksi.ksi_uid = td->td_ucred->cr_ruid;
1842 ksi.ksi_value.sival_ptr = uap->value;
1843 error = pksignal(p, ksi.ksi_signo, &ksi);
1850 * Send a signal to a process group.
1853 gsignal(int pgid, int sig, ksiginfo_t *ksi)
1858 sx_slock(&proctree_lock);
1859 pgrp = pgfind(pgid);
1860 sx_sunlock(&proctree_lock);
1862 pgsignal(pgrp, sig, 0, ksi);
1869 * Send a signal to a process group. If checktty is 1,
1870 * limit to members which have a controlling terminal.
1873 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi)
1878 PGRP_LOCK_ASSERT(pgrp, MA_OWNED);
1879 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
1881 if (p->p_state == PRS_NORMAL &&
1882 (checkctty == 0 || p->p_flag & P_CONTROLT))
1883 pksignal(p, sig, ksi);
1891 * Recalculate the signal mask and reset the signal disposition after
1892 * usermode frame for delivery is formed. Should be called after
1893 * mach-specific routine, because sysent->sv_sendsig() needs correct
1894 * ps_siginfo and signal mask.
1897 postsig_done(int sig, struct thread *td, struct sigacts *ps)
1901 mtx_assert(&ps->ps_mtx, MA_OWNED);
1902 td->td_ru.ru_nsignals++;
1903 mask = ps->ps_catchmask[_SIG_IDX(sig)];
1904 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1905 SIGADDSET(mask, sig);
1906 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL,
1907 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED);
1908 if (SIGISMEMBER(ps->ps_sigreset, sig))
1914 * Send a signal caused by a trap to the current thread. If it will be
1915 * caught immediately, deliver it with correct code. Otherwise, post it
1919 trapsignal(struct thread *td, ksiginfo_t *ksi)
1927 sig = ksi->ksi_signo;
1928 code = ksi->ksi_code;
1929 KASSERT(_SIG_VALID(sig), ("invalid signal"));
1933 mtx_lock(&ps->ps_mtx);
1934 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) &&
1935 !SIGISMEMBER(td->td_sigmask, sig)) {
1937 if (KTRPOINT(curthread, KTR_PSIG))
1938 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)],
1939 &td->td_sigmask, code);
1941 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)],
1942 ksi, &td->td_sigmask);
1943 postsig_done(sig, td, ps);
1944 mtx_unlock(&ps->ps_mtx);
1947 * Avoid a possible infinite loop if the thread
1948 * masking the signal or process is ignoring the
1951 if (kern_forcesigexit &&
1952 (SIGISMEMBER(td->td_sigmask, sig) ||
1953 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) {
1954 SIGDELSET(td->td_sigmask, sig);
1955 SIGDELSET(ps->ps_sigcatch, sig);
1956 SIGDELSET(ps->ps_sigignore, sig);
1957 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1959 mtx_unlock(&ps->ps_mtx);
1960 p->p_code = code; /* XXX for core dump/debugger */
1961 p->p_sig = sig; /* XXX to verify code */
1962 tdsendsignal(p, td, sig, ksi);
1967 static struct thread *
1968 sigtd(struct proc *p, int sig, int prop)
1970 struct thread *td, *signal_td;
1972 PROC_LOCK_ASSERT(p, MA_OWNED);
1975 * Check if current thread can handle the signal without
1976 * switching context to another thread.
1978 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig))
1981 FOREACH_THREAD_IN_PROC(p, td) {
1982 if (!SIGISMEMBER(td->td_sigmask, sig)) {
1987 if (signal_td == NULL)
1988 signal_td = FIRST_THREAD_IN_PROC(p);
1993 * Send the signal to the process. If the signal has an action, the action
1994 * is usually performed by the target process rather than the caller; we add
1995 * the signal to the set of pending signals for the process.
1998 * o When a stop signal is sent to a sleeping process that takes the
1999 * default action, the process is stopped without awakening it.
2000 * o SIGCONT restarts stopped processes (or puts them back to sleep)
2001 * regardless of the signal action (eg, blocked or ignored).
2003 * Other ignored signals are discarded immediately.
2005 * NB: This function may be entered from the debugger via the "kill" DDB
2006 * command. There is little that can be done to mitigate the possibly messy
2007 * side effects of this unwise possibility.
2010 kern_psignal(struct proc *p, int sig)
2014 ksiginfo_init(&ksi);
2015 ksi.ksi_signo = sig;
2016 ksi.ksi_code = SI_KERNEL;
2017 (void) tdsendsignal(p, NULL, sig, &ksi);
2021 pksignal(struct proc *p, int sig, ksiginfo_t *ksi)
2024 return (tdsendsignal(p, NULL, sig, ksi));
2027 /* Utility function for finding a thread to send signal event to. */
2029 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd)
2033 if (sigev->sigev_notify == SIGEV_THREAD_ID) {
2034 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid);
2046 tdsignal(struct thread *td, int sig)
2050 ksiginfo_init(&ksi);
2051 ksi.ksi_signo = sig;
2052 ksi.ksi_code = SI_KERNEL;
2053 (void) tdsendsignal(td->td_proc, td, sig, &ksi);
2057 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi)
2060 (void) tdsendsignal(td->td_proc, td, sig, ksi);
2064 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi)
2067 sigqueue_t *sigqueue;
2074 MPASS(td == NULL || p == td->td_proc);
2075 PROC_LOCK_ASSERT(p, MA_OWNED);
2077 if (!_SIG_VALID(sig))
2078 panic("%s(): invalid signal %d", __func__, sig);
2080 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__));
2083 * IEEE Std 1003.1-2001: return success when killing a zombie.
2085 if (p->p_state == PRS_ZOMBIE) {
2086 if (ksi && (ksi->ksi_flags & KSI_INS))
2087 ksiginfo_tryfree(ksi);
2092 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig);
2093 prop = sigprop(sig);
2096 td = sigtd(p, sig, prop);
2097 sigqueue = &p->p_sigqueue;
2099 sigqueue = &td->td_sigqueue;
2101 SDT_PROBE(proc, kernel, , signal__send, td, p, sig, 0, 0 );
2104 * If the signal is being ignored,
2105 * then we forget about it immediately.
2106 * (Note: we don't set SIGCONT in ps_sigignore,
2107 * and if it is set to SIG_IGN,
2108 * action will be SIG_DFL here.)
2110 mtx_lock(&ps->ps_mtx);
2111 if (SIGISMEMBER(ps->ps_sigignore, sig)) {
2112 SDT_PROBE(proc, kernel, , signal__discard, td, p, sig, 0, 0 );
2114 mtx_unlock(&ps->ps_mtx);
2115 if (ksi && (ksi->ksi_flags & KSI_INS))
2116 ksiginfo_tryfree(ksi);
2119 if (SIGISMEMBER(td->td_sigmask, sig))
2121 else if (SIGISMEMBER(ps->ps_sigcatch, sig))
2125 if (SIGISMEMBER(ps->ps_sigintr, sig))
2129 mtx_unlock(&ps->ps_mtx);
2132 sigqueue_delete_stopmask_proc(p);
2133 else if (prop & SA_STOP) {
2135 * If sending a tty stop signal to a member of an orphaned
2136 * process group, discard the signal here if the action
2137 * is default; don't stop the process below if sleeping,
2138 * and don't clear any pending SIGCONT.
2140 if ((prop & SA_TTYSTOP) &&
2141 (p->p_pgrp->pg_jobc == 0) &&
2142 (action == SIG_DFL)) {
2143 if (ksi && (ksi->ksi_flags & KSI_INS))
2144 ksiginfo_tryfree(ksi);
2147 sigqueue_delete_proc(p, SIGCONT);
2148 if (p->p_flag & P_CONTINUED) {
2149 p->p_flag &= ~P_CONTINUED;
2150 PROC_LOCK(p->p_pptr);
2151 sigqueue_take(p->p_ksi);
2152 PROC_UNLOCK(p->p_pptr);
2156 ret = sigqueue_add(sigqueue, sig, ksi);
2161 * Defer further processing for signals which are held,
2162 * except that stopped processes must be continued by SIGCONT.
2164 if (action == SIG_HOLD &&
2165 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG)))
2168 * SIGKILL: Remove procfs STOPEVENTs.
2170 if (sig == SIGKILL) {
2171 /* from procfs_ioctl.c: PIOCBIC */
2173 /* from procfs_ioctl.c: PIOCCONT */
2178 * Some signals have a process-wide effect and a per-thread
2179 * component. Most processing occurs when the process next
2180 * tries to cross the user boundary, however there are some
2181 * times when processing needs to be done immediately, such as
2182 * waking up threads so that they can cross the user boundary.
2183 * We try to do the per-process part here.
2185 if (P_SHOULDSTOP(p)) {
2186 KASSERT(!(p->p_flag & P_WEXIT),
2187 ("signal to stopped but exiting process"));
2188 if (sig == SIGKILL) {
2190 * If traced process is already stopped,
2191 * then no further action is necessary.
2193 if (p->p_flag & P_TRACED)
2196 * SIGKILL sets process running.
2197 * It will die elsewhere.
2198 * All threads must be restarted.
2200 p->p_flag &= ~P_STOPPED_SIG;
2204 if (prop & SA_CONT) {
2206 * If traced process is already stopped,
2207 * then no further action is necessary.
2209 if (p->p_flag & P_TRACED)
2212 * If SIGCONT is default (or ignored), we continue the
2213 * process but don't leave the signal in sigqueue as
2214 * it has no further action. If SIGCONT is held, we
2215 * continue the process and leave the signal in
2216 * sigqueue. If the process catches SIGCONT, let it
2217 * handle the signal itself. If it isn't waiting on
2218 * an event, it goes back to run state.
2219 * Otherwise, process goes back to sleep state.
2221 p->p_flag &= ~P_STOPPED_SIG;
2223 if (p->p_numthreads == p->p_suspcount) {
2225 p->p_flag |= P_CONTINUED;
2226 p->p_xstat = SIGCONT;
2227 PROC_LOCK(p->p_pptr);
2228 childproc_continued(p);
2229 PROC_UNLOCK(p->p_pptr);
2232 if (action == SIG_DFL) {
2233 thread_unsuspend(p);
2235 sigqueue_delete(sigqueue, sig);
2238 if (action == SIG_CATCH) {
2240 * The process wants to catch it so it needs
2241 * to run at least one thread, but which one?
2247 * The signal is not ignored or caught.
2249 thread_unsuspend(p);
2254 if (prop & SA_STOP) {
2256 * If traced process is already stopped,
2257 * then no further action is necessary.
2259 if (p->p_flag & P_TRACED)
2262 * Already stopped, don't need to stop again
2263 * (If we did the shell could get confused).
2264 * Just make sure the signal STOP bit set.
2266 p->p_flag |= P_STOPPED_SIG;
2267 sigqueue_delete(sigqueue, sig);
2272 * All other kinds of signals:
2273 * If a thread is sleeping interruptibly, simulate a
2274 * wakeup so that when it is continued it will be made
2275 * runnable and can look at the signal. However, don't make
2276 * the PROCESS runnable, leave it stopped.
2277 * It may run a bit until it hits a thread_suspend_check().
2282 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR))
2283 wakeup_swapper = sleepq_abort(td, intrval);
2290 * Mutexes are short lived. Threads waiting on them will
2291 * hit thread_suspend_check() soon.
2293 } else if (p->p_state == PRS_NORMAL) {
2294 if (p->p_flag & P_TRACED || action == SIG_CATCH) {
2295 tdsigwakeup(td, sig, action, intrval);
2299 MPASS(action == SIG_DFL);
2301 if (prop & SA_STOP) {
2302 if (p->p_flag & (P_PPWAIT|P_WEXIT))
2304 p->p_flag |= P_STOPPED_SIG;
2307 sig_suspend_threads(td, p, 1);
2308 if (p->p_numthreads == p->p_suspcount) {
2310 * only thread sending signal to another
2311 * process can reach here, if thread is sending
2312 * signal to its process, because thread does
2313 * not suspend itself here, p_numthreads
2314 * should never be equal to p_suspcount.
2318 sigqueue_delete_proc(p, p->p_xstat);
2324 /* Not in "NORMAL" state. discard the signal. */
2325 sigqueue_delete(sigqueue, sig);
2330 * The process is not stopped so we need to apply the signal to all the
2334 tdsigwakeup(td, sig, action, intrval);
2336 thread_unsuspend(p);
2339 /* If we jump here, proc slock should not be owned. */
2340 PROC_SLOCK_ASSERT(p, MA_NOTOWNED);
2345 * The force of a signal has been directed against a single
2346 * thread. We need to see what we can do about knocking it
2347 * out of any sleep it may be in etc.
2350 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval)
2352 struct proc *p = td->td_proc;
2357 PROC_LOCK_ASSERT(p, MA_OWNED);
2358 prop = sigprop(sig);
2363 * Bring the priority of a thread up if we want it to get
2364 * killed in this lifetime.
2366 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER)
2367 sched_prio(td, PUSER);
2368 if (TD_ON_SLEEPQ(td)) {
2370 * If thread is sleeping uninterruptibly
2371 * we can't interrupt the sleep... the signal will
2372 * be noticed when the process returns through
2373 * trap() or syscall().
2375 if ((td->td_flags & TDF_SINTR) == 0)
2378 * If SIGCONT is default (or ignored) and process is
2379 * asleep, we are finished; the process should not
2382 if ((prop & SA_CONT) && action == SIG_DFL) {
2385 sigqueue_delete(&p->p_sigqueue, sig);
2387 * It may be on either list in this state.
2388 * Remove from both for now.
2390 sigqueue_delete(&td->td_sigqueue, sig);
2395 * Don't awaken a sleeping thread for SIGSTOP if the
2396 * STOP signal is deferred.
2398 if ((prop & SA_STOP) && (td->td_flags & TDF_SBDRY))
2402 * Give low priority threads a better chance to run.
2404 if (td->td_priority > PUSER)
2405 sched_prio(td, PUSER);
2407 wakeup_swapper = sleepq_abort(td, intrval);
2410 * Other states do nothing with the signal immediately,
2411 * other than kicking ourselves if we are running.
2412 * It will either never be noticed, or noticed very soon.
2415 if (TD_IS_RUNNING(td) && td != curthread)
2427 sig_suspend_threads(struct thread *td, struct proc *p, int sending)
2431 PROC_LOCK_ASSERT(p, MA_OWNED);
2432 PROC_SLOCK_ASSERT(p, MA_OWNED);
2434 FOREACH_THREAD_IN_PROC(p, td2) {
2436 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK;
2437 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) &&
2438 (td2->td_flags & TDF_SINTR)) {
2439 if (td2->td_flags & TDF_SBDRY) {
2441 * Once a thread is asleep with
2442 * TDF_SBDRY set, it should never
2443 * become suspended due to this check.
2445 KASSERT(!TD_IS_SUSPENDED(td2),
2446 ("thread with deferred stops suspended"));
2447 } else if (!TD_IS_SUSPENDED(td2)) {
2448 thread_suspend_one(td2);
2450 } else if (!TD_IS_SUSPENDED(td2)) {
2451 if (sending || td != td2)
2452 td2->td_flags |= TDF_ASTPENDING;
2454 if (TD_IS_RUNNING(td2) && td2 != td)
2455 forward_signal(td2);
2463 ptracestop(struct thread *td, int sig)
2465 struct proc *p = td->td_proc;
2467 PROC_LOCK_ASSERT(p, MA_OWNED);
2468 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process"));
2469 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
2470 &p->p_mtx.lock_object, "Stopping for traced signal");
2472 td->td_dbgflags |= TDB_XSIG;
2475 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) {
2476 if (p->p_flag & P_SINGLE_EXIT) {
2477 td->td_dbgflags &= ~TDB_XSIG;
2482 * Just make wait() to work, the last stopped thread
2487 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE);
2488 sig_suspend_threads(td, p, 0);
2489 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) {
2490 td->td_dbgflags &= ~TDB_STOPATFORK;
2491 cv_broadcast(&p->p_dbgwait);
2494 thread_suspend_switch(td, p);
2495 if (p->p_xthread == td)
2496 p->p_xthread = NULL;
2497 if (!(p->p_flag & P_TRACED))
2499 if (td->td_dbgflags & TDB_SUSPEND) {
2500 if (p->p_flag & P_SINGLE_EXIT)
2506 return (td->td_xsig);
2510 reschedule_signals(struct proc *p, sigset_t block, int flags)
2516 PROC_LOCK_ASSERT(p, MA_OWNED);
2518 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ?
2519 MA_OWNED : MA_NOTOWNED);
2520 if (SIGISEMPTY(p->p_siglist))
2522 SIGSETAND(block, p->p_siglist);
2523 while ((sig = sig_ffs(&block)) != 0) {
2524 SIGDELSET(block, sig);
2525 td = sigtd(p, sig, 0);
2527 if (!(flags & SIGPROCMASK_PS_LOCKED))
2528 mtx_lock(&ps->ps_mtx);
2529 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig))
2530 tdsigwakeup(td, sig, SIG_CATCH,
2531 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR :
2533 if (!(flags & SIGPROCMASK_PS_LOCKED))
2534 mtx_unlock(&ps->ps_mtx);
2539 tdsigcleanup(struct thread *td)
2545 PROC_LOCK_ASSERT(p, MA_OWNED);
2547 sigqueue_flush(&td->td_sigqueue);
2548 if (p->p_numthreads == 1)
2552 * Since we cannot handle signals, notify signal post code
2553 * about this by filling the sigmask.
2555 * Also, if needed, wake up thread(s) that do not block the
2556 * same signals as the exiting thread, since the thread might
2557 * have been selected for delivery and woken up.
2559 SIGFILLSET(unblocked);
2560 SIGSETNAND(unblocked, td->td_sigmask);
2561 SIGFILLSET(td->td_sigmask);
2562 reschedule_signals(p, unblocked, 0);
2567 * Defer the delivery of SIGSTOP for the current thread. Returns true
2568 * if stops were deferred and false if they were already deferred.
2576 if (td->td_flags & TDF_SBDRY)
2579 td->td_flags |= TDF_SBDRY;
2585 * Permit the delivery of SIGSTOP for the current thread. This does
2586 * not immediately suspend if a stop was posted. Instead, the thread
2587 * will suspend either via ast() or a subsequent interruptible sleep.
2596 td->td_flags &= ~TDF_SBDRY;
2601 * If the current process has received a signal (should be caught or cause
2602 * termination, should interrupt current syscall), return the signal number.
2603 * Stop signals with default action are processed immediately, then cleared;
2604 * they aren't returned. This is checked after each entry to the system for
2605 * a syscall or trap (though this can usually be done without calling issignal
2606 * by checking the pending signal masks in cursig.) The normal call
2609 * while (sig = cursig(curthread))
2613 issignal(struct thread *td)
2617 struct sigqueue *queue;
2618 sigset_t sigpending;
2619 int sig, prop, newsig;
2623 mtx_assert(&ps->ps_mtx, MA_OWNED);
2624 PROC_LOCK_ASSERT(p, MA_OWNED);
2626 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
2628 sigpending = td->td_sigqueue.sq_signals;
2629 SIGSETOR(sigpending, p->p_sigqueue.sq_signals);
2630 SIGSETNAND(sigpending, td->td_sigmask);
2632 if (p->p_flag & P_PPWAIT || td->td_flags & TDF_SBDRY)
2633 SIG_STOPSIGMASK(sigpending);
2634 if (SIGISEMPTY(sigpending)) /* no signal to send */
2636 sig = sig_ffs(&sigpending);
2638 if (p->p_stops & S_SIG) {
2639 mtx_unlock(&ps->ps_mtx);
2640 stopevent(p, S_SIG, sig);
2641 mtx_lock(&ps->ps_mtx);
2645 * We should see pending but ignored signals
2646 * only if P_TRACED was on when they were posted.
2648 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) {
2649 sigqueue_delete(&td->td_sigqueue, sig);
2650 sigqueue_delete(&p->p_sigqueue, sig);
2653 if (p->p_flag & P_TRACED && (p->p_flag & P_PPTRACE) == 0) {
2655 * If traced, always stop.
2656 * Remove old signal from queue before the stop.
2657 * XXX shrug off debugger, it causes siginfo to
2660 queue = &td->td_sigqueue;
2661 td->td_dbgksi.ksi_signo = 0;
2662 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) {
2663 queue = &p->p_sigqueue;
2664 sigqueue_get(queue, sig, &td->td_dbgksi);
2667 mtx_unlock(&ps->ps_mtx);
2668 newsig = ptracestop(td, sig);
2669 mtx_lock(&ps->ps_mtx);
2671 if (sig != newsig) {
2674 * If parent wants us to take the signal,
2675 * then it will leave it in p->p_xstat;
2676 * otherwise we just look for signals again.
2683 * Put the new signal into td_sigqueue. If the
2684 * signal is being masked, look for other
2687 sigqueue_add(queue, sig, NULL);
2688 if (SIGISMEMBER(td->td_sigmask, sig))
2692 if (td->td_dbgksi.ksi_signo != 0) {
2693 td->td_dbgksi.ksi_flags |= KSI_HEAD;
2694 if (sigqueue_add(&td->td_sigqueue, sig,
2695 &td->td_dbgksi) != 0)
2696 td->td_dbgksi.ksi_signo = 0;
2698 if (td->td_dbgksi.ksi_signo == 0)
2699 sigqueue_add(&td->td_sigqueue, sig,
2704 * If the traced bit got turned off, go back up
2705 * to the top to rescan signals. This ensures
2706 * that p_sig* and p_sigact are consistent.
2708 if ((p->p_flag & P_TRACED) == 0)
2712 prop = sigprop(sig);
2715 * Decide whether the signal should be returned.
2716 * Return the signal's number, or fall through
2717 * to clear it from the pending mask.
2719 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
2721 case (intptr_t)SIG_DFL:
2723 * Don't take default actions on system processes.
2725 if (p->p_pid <= 1) {
2728 * Are you sure you want to ignore SIGSEGV
2731 printf("Process (pid %lu) got signal %d\n",
2732 (u_long)p->p_pid, sig);
2734 break; /* == ignore */
2737 * If there is a pending stop signal to process
2738 * with default action, stop here,
2739 * then clear the signal. However,
2740 * if process is member of an orphaned
2741 * process group, ignore tty stop signals.
2743 if (prop & SA_STOP) {
2744 if (p->p_flag & (P_TRACED|P_WEXIT) ||
2745 (p->p_pgrp->pg_jobc == 0 &&
2747 break; /* == ignore */
2748 mtx_unlock(&ps->ps_mtx);
2749 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
2750 &p->p_mtx.lock_object, "Catching SIGSTOP");
2751 p->p_flag |= P_STOPPED_SIG;
2754 sig_suspend_threads(td, p, 0);
2755 thread_suspend_switch(td, p);
2757 mtx_lock(&ps->ps_mtx);
2759 } else if (prop & SA_IGNORE) {
2761 * Except for SIGCONT, shouldn't get here.
2762 * Default action is to ignore; drop it.
2764 break; /* == ignore */
2769 case (intptr_t)SIG_IGN:
2771 * Masking above should prevent us ever trying
2772 * to take action on an ignored signal other
2773 * than SIGCONT, unless process is traced.
2775 if ((prop & SA_CONT) == 0 &&
2776 (p->p_flag & P_TRACED) == 0)
2777 printf("issignal\n");
2778 break; /* == ignore */
2782 * This signal has an action, let
2783 * postsig() process it.
2787 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */
2788 sigqueue_delete(&p->p_sigqueue, sig);
2794 thread_stopped(struct proc *p)
2798 PROC_LOCK_ASSERT(p, MA_OWNED);
2799 PROC_SLOCK_ASSERT(p, MA_OWNED);
2803 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) {
2805 p->p_flag &= ~P_WAITED;
2806 PROC_LOCK(p->p_pptr);
2807 childproc_stopped(p, (p->p_flag & P_TRACED) ?
2808 CLD_TRAPPED : CLD_STOPPED);
2809 PROC_UNLOCK(p->p_pptr);
2815 * Take the action for the specified signal
2816 * from the current set of pending signals.
2822 struct thread *td = curthread;
2823 register struct proc *p = td->td_proc;
2827 sigset_t returnmask;
2829 KASSERT(sig != 0, ("postsig"));
2831 PROC_LOCK_ASSERT(p, MA_OWNED);
2833 mtx_assert(&ps->ps_mtx, MA_OWNED);
2834 ksiginfo_init(&ksi);
2835 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 &&
2836 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0)
2838 ksi.ksi_signo = sig;
2839 if (ksi.ksi_code == SI_TIMER)
2840 itimer_accept(p, ksi.ksi_timerid, &ksi);
2841 action = ps->ps_sigact[_SIG_IDX(sig)];
2843 if (KTRPOINT(td, KTR_PSIG))
2844 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ?
2845 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code);
2847 if (p->p_stops & S_SIG) {
2848 mtx_unlock(&ps->ps_mtx);
2849 stopevent(p, S_SIG, sig);
2850 mtx_lock(&ps->ps_mtx);
2853 if (action == SIG_DFL) {
2855 * Default action, where the default is to kill
2856 * the process. (Other cases were ignored above.)
2858 mtx_unlock(&ps->ps_mtx);
2863 * If we get here, the signal must be caught.
2865 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig),
2866 ("postsig action"));
2868 * Set the new mask value and also defer further
2869 * occurrences of this signal.
2871 * Special case: user has done a sigsuspend. Here the
2872 * current mask is not of interest, but rather the
2873 * mask from before the sigsuspend is what we want
2874 * restored after the signal processing is completed.
2876 if (td->td_pflags & TDP_OLDMASK) {
2877 returnmask = td->td_oldsigmask;
2878 td->td_pflags &= ~TDP_OLDMASK;
2880 returnmask = td->td_sigmask;
2882 if (p->p_sig == sig) {
2886 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask);
2887 postsig_done(sig, td, ps);
2893 * Kill the current process for stated reason.
2901 PROC_LOCK_ASSERT(p, MA_OWNED);
2902 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid,
2904 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid,
2905 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why);
2906 p->p_flag |= P_WKILLED;
2907 kern_psignal(p, SIGKILL);
2911 * Force the current process to exit with the specified signal, dumping core
2912 * if appropriate. We bypass the normal tests for masked and caught signals,
2913 * allowing unrecoverable failures to terminate the process without changing
2914 * signal state. Mark the accounting record with the signal termination.
2915 * If dumping core, save the signal number for the debugger. Calls exit and
2923 struct proc *p = td->td_proc;
2925 PROC_LOCK_ASSERT(p, MA_OWNED);
2926 p->p_acflag |= AXSIG;
2928 * We must be single-threading to generate a core dump. This
2929 * ensures that the registers in the core file are up-to-date.
2930 * Also, the ELF dump handler assumes that the thread list doesn't
2931 * change out from under it.
2933 * XXX If another thread attempts to single-thread before us
2934 * (e.g. via fork()), we won't get a dump at all.
2936 if ((sigprop(sig) & SA_CORE) && thread_single(p, SINGLE_NO_EXIT) == 0) {
2939 * Log signals which would cause core dumps
2940 * (Log as LOG_INFO to appease those who don't want
2942 * XXX : Todo, as well as euid, write out ruid too
2943 * Note that coredump() drops proc lock.
2945 if (coredump(td) == 0)
2947 if (kern_logsigexit)
2949 "pid %d (%s), uid %d: exited on signal %d%s\n",
2950 p->p_pid, p->p_comm,
2951 td->td_ucred ? td->td_ucred->cr_uid : -1,
2953 sig & WCOREFLAG ? " (core dumped)" : "");
2956 exit1(td, W_EXITCODE(0, sig));
2961 * Send queued SIGCHLD to parent when child process's state
2965 sigparent(struct proc *p, int reason, int status)
2967 PROC_LOCK_ASSERT(p, MA_OWNED);
2968 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
2970 if (p->p_ksi != NULL) {
2971 p->p_ksi->ksi_signo = SIGCHLD;
2972 p->p_ksi->ksi_code = reason;
2973 p->p_ksi->ksi_status = status;
2974 p->p_ksi->ksi_pid = p->p_pid;
2975 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid;
2976 if (KSI_ONQ(p->p_ksi))
2979 pksignal(p->p_pptr, SIGCHLD, p->p_ksi);
2983 childproc_jobstate(struct proc *p, int reason, int sig)
2987 PROC_LOCK_ASSERT(p, MA_OWNED);
2988 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
2991 * Wake up parent sleeping in kern_wait(), also send
2992 * SIGCHLD to parent, but SIGCHLD does not guarantee
2993 * that parent will awake, because parent may masked
2996 p->p_pptr->p_flag |= P_STATCHILD;
2999 ps = p->p_pptr->p_sigacts;
3000 mtx_lock(&ps->ps_mtx);
3001 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) {
3002 mtx_unlock(&ps->ps_mtx);
3003 sigparent(p, reason, sig);
3005 mtx_unlock(&ps->ps_mtx);
3009 childproc_stopped(struct proc *p, int reason)
3011 /* p_xstat is a plain signal number, not a full wait() status here. */
3012 childproc_jobstate(p, reason, p->p_xstat);
3016 childproc_continued(struct proc *p)
3018 childproc_jobstate(p, CLD_CONTINUED, SIGCONT);
3022 childproc_exited(struct proc *p)
3025 int xstat = p->p_xstat; /* convert to int */
3028 if (WCOREDUMP(xstat))
3029 reason = CLD_DUMPED, status = WTERMSIG(xstat);
3030 else if (WIFSIGNALED(xstat))
3031 reason = CLD_KILLED, status = WTERMSIG(xstat);
3033 reason = CLD_EXITED, status = WEXITSTATUS(xstat);
3035 * XXX avoid calling wakeup(p->p_pptr), the work is
3038 sigparent(p, reason, status);
3042 * We only have 1 character for the core count in the format
3043 * string, so the range will be 0-9
3045 #define MAX_NUM_CORES 10
3046 static int num_cores = 5;
3049 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS)
3054 new_val = num_cores;
3055 error = sysctl_handle_int(oidp, &new_val, 0, req);
3056 if (error != 0 || req->newptr == NULL)
3058 if (new_val > MAX_NUM_CORES)
3059 new_val = MAX_NUM_CORES;
3062 num_cores = new_val;
3065 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW,
3066 0, sizeof(int), sysctl_debug_num_cores_check, "I", "");
3068 #if defined(COMPRESS_USER_CORES)
3069 int compress_user_cores = 1;
3070 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RW,
3071 &compress_user_cores, 0, "Compression of user corefiles");
3073 int compress_user_cores_gzlevel = -1; /* default level */
3074 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RW,
3075 &compress_user_cores_gzlevel, -1, "Corefile gzip compression level");
3077 #define GZ_SUFFIX ".gz"
3078 #define GZ_SUFFIX_LEN 3
3081 static char corefilename[MAXPATHLEN] = {"%N.core"};
3082 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RWTUN, corefilename,
3083 sizeof(corefilename), "Process corefile name format string");
3086 * corefile_open(comm, uid, pid, td, compress, vpp, namep)
3087 * Expand the name described in corefilename, using name, uid, and pid
3088 * and open/create core file.
3089 * corefilename is a printf-like string, with three format specifiers:
3090 * %N name of process ("name")
3091 * %P process id (pid)
3093 * For example, "%N.core" is the default; they can be disabled completely
3094 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
3095 * This is controlled by the sysctl variable kern.corefile (see above).
3098 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td,
3099 int compress, struct vnode **vpp, char **namep)
3101 struct nameidata nd;
3104 char *hostname, *name;
3105 int indexpos, i, error, cmode, flags, oflags;
3108 format = corefilename;
3109 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO);
3111 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN);
3112 for (i = 0; format[i] != '\0'; i++) {
3113 switch (format[i]) {
3114 case '%': /* Format character */
3116 switch (format[i]) {
3118 sbuf_putc(&sb, '%');
3120 case 'H': /* hostname */
3121 if (hostname == NULL) {
3122 hostname = malloc(MAXHOSTNAMELEN,
3125 getcredhostname(td->td_ucred, hostname,
3127 sbuf_printf(&sb, "%s", hostname);
3129 case 'I': /* autoincrementing index */
3130 sbuf_printf(&sb, "0");
3131 indexpos = sbuf_len(&sb) - 1;
3133 case 'N': /* process name */
3134 sbuf_printf(&sb, "%s", comm);
3136 case 'P': /* process id */
3137 sbuf_printf(&sb, "%u", pid);
3139 case 'U': /* user id */
3140 sbuf_printf(&sb, "%u", uid);
3144 "Unknown format character %c in "
3145 "corename `%s'\n", format[i], format);
3150 sbuf_putc(&sb, format[i]);
3154 free(hostname, M_TEMP);
3155 #ifdef COMPRESS_USER_CORES
3157 sbuf_printf(&sb, GZ_SUFFIX);
3159 if (sbuf_error(&sb) != 0) {
3160 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too "
3161 "long\n", (long)pid, comm, (u_long)uid);
3169 cmode = S_IRUSR | S_IWUSR;
3170 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE |
3171 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0);
3174 * If the core format has a %I in it, then we need to check
3175 * for existing corefiles before returning a name.
3176 * To do this we iterate over 0..num_cores to find a
3177 * non-existing core file name to use.
3179 if (indexpos != -1) {
3180 for (i = 0; i < num_cores; i++) {
3181 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW;
3182 name[indexpos] = '0' + i;
3183 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td);
3184 error = vn_open_cred(&nd, &flags, cmode, oflags,
3185 td->td_ucred, NULL);
3187 if (error == EEXIST)
3190 "pid %d (%s), uid (%u): Path `%s' failed "
3191 "on initial open test, error = %d\n",
3192 pid, comm, uid, name, error);
3198 flags = O_CREAT | FWRITE | O_NOFOLLOW;
3199 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td);
3200 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL);
3204 audit_proc_coredump(td, name, error);
3209 NDFREE(&nd, NDF_ONLY_PNBUF);
3216 * Dump a process' core. The main routine does some
3217 * policy checking, and creates the name of the coredump;
3218 * then it passes on a vnode and a size limit to the process-specific
3219 * coredump routine if there is one; if there _is not_ one, it returns
3220 * ENOSYS; otherwise it returns the error from the process-specific routine.
3224 coredump(struct thread *td)
3226 struct proc *p = td->td_proc;
3227 struct ucred *cred = td->td_ucred;
3231 int error, error1, locked;
3232 char *name; /* name of corefile */
3237 #ifdef COMPRESS_USER_CORES
3238 compress = compress_user_cores;
3242 PROC_LOCK_ASSERT(p, MA_OWNED);
3243 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td);
3244 _STOPEVENT(p, S_CORE, 0);
3246 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0)) {
3252 * Note that the bulk of limit checking is done after
3253 * the corefile is created. The exception is if the limit
3254 * for corefiles is 0, in which case we don't bother
3255 * creating the corefile at all. This layout means that
3256 * a corefile is truncated instead of not being created,
3257 * if it is larger than the limit.
3259 limit = (off_t)lim_cur(p, RLIMIT_CORE);
3260 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) {
3266 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, compress,
3272 * Don't dump to non-regular files or files with links.
3273 * Do not dump into system files.
3275 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 ||
3276 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0) {
3284 /* Postpone other writers, including core dumps of other processes. */
3285 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
3287 lf.l_whence = SEEK_SET;
3290 lf.l_type = F_WRLCK;
3291 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0);
3295 if (set_core_nodump_flag)
3296 vattr.va_flags = UF_NODUMP;
3297 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3298 VOP_SETATTR(vp, &vattr, cred);
3301 p->p_acflag |= ACORE;
3304 if (p->p_sysent->sv_coredump != NULL) {
3305 error = p->p_sysent->sv_coredump(td, vp, limit,
3306 compress ? IMGACT_CORE_COMPRESS : 0);
3312 lf.l_type = F_UNLCK;
3313 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
3315 vn_rangelock_unlock(vp, rl_cookie);
3317 error1 = vn_close(vp, FWRITE, cred, td);
3321 audit_proc_coredump(td, name, error);
3328 * Nonexistent system call-- signal process (may want to handle it). Flag
3329 * error in case process won't see signal immediately (blocked or ignored).
3331 #ifndef _SYS_SYSPROTO_H_
3340 struct nosys_args *args;
3342 struct proc *p = td->td_proc;
3345 tdsignal(td, SIGSYS);
3351 * Send a SIGIO or SIGURG signal to a process or process group using stored
3352 * credentials rather than those of the current process.
3355 pgsigio(sigiop, sig, checkctty)
3356 struct sigio **sigiop;
3360 struct sigio *sigio;
3362 ksiginfo_init(&ksi);
3363 ksi.ksi_signo = sig;
3364 ksi.ksi_code = SI_KERNEL;
3368 if (sigio == NULL) {
3372 if (sigio->sio_pgid > 0) {
3373 PROC_LOCK(sigio->sio_proc);
3374 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred))
3375 kern_psignal(sigio->sio_proc, sig);
3376 PROC_UNLOCK(sigio->sio_proc);
3377 } else if (sigio->sio_pgid < 0) {
3380 PGRP_LOCK(sigio->sio_pgrp);
3381 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
3383 if (p->p_state == PRS_NORMAL &&
3384 CANSIGIO(sigio->sio_ucred, p->p_ucred) &&
3385 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
3386 kern_psignal(p, sig);
3389 PGRP_UNLOCK(sigio->sio_pgrp);
3395 filt_sigattach(struct knote *kn)
3397 struct proc *p = curproc;
3399 kn->kn_ptr.p_proc = p;
3400 kn->kn_flags |= EV_CLEAR; /* automatically set */
3402 knlist_add(&p->p_klist, kn, 0);
3408 filt_sigdetach(struct knote *kn)
3410 struct proc *p = kn->kn_ptr.p_proc;
3412 knlist_remove(&p->p_klist, kn, 0);
3416 * signal knotes are shared with proc knotes, so we apply a mask to
3417 * the hint in order to differentiate them from process hints. This
3418 * could be avoided by using a signal-specific knote list, but probably
3419 * isn't worth the trouble.
3422 filt_signal(struct knote *kn, long hint)
3425 if (hint & NOTE_SIGNAL) {
3426 hint &= ~NOTE_SIGNAL;
3428 if (kn->kn_id == hint)
3431 return (kn->kn_data != 0);
3439 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO);
3440 refcount_init(&ps->ps_refcnt, 1);
3441 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF);
3446 sigacts_free(struct sigacts *ps)
3449 if (refcount_release(&ps->ps_refcnt) == 0)
3451 mtx_destroy(&ps->ps_mtx);
3452 free(ps, M_SUBPROC);
3456 sigacts_hold(struct sigacts *ps)
3459 refcount_acquire(&ps->ps_refcnt);
3464 sigacts_copy(struct sigacts *dest, struct sigacts *src)
3467 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest"));
3468 mtx_lock(&src->ps_mtx);
3469 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt));
3470 mtx_unlock(&src->ps_mtx);
3474 sigacts_shared(struct sigacts *ps)
3477 return (ps->ps_refcnt > 1);