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Create the USB task queues before creating the event thread to avoid
[dragonfly/vkernel-mp.git] / sys / kern / kern_sig.c
blob933340e3414db562f430fe5ad56b22fa3eb4693a
1 /*
2 * Copyright (c) 1982, 1986, 1989, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94
39 * $FreeBSD: src/sys/kern/kern_sig.c,v 1.72.2.17 2003/05/16 16:34:34 obrien Exp $
40 * $DragonFly: src/sys/kern/kern_sig.c,v 1.78 2007/05/24 20:51:16 dillon Exp $
41 */
42
43 #include "opt_ktrace.h"
44
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/kernel.h>
48 #include <sys/sysproto.h>
49 #include <sys/signalvar.h>
50 #include <sys/signal2.h>
51 #include <sys/resourcevar.h>
52 #include <sys/vnode.h>
53 #include <sys/event.h>
54 #include <sys/proc.h>
55 #include <sys/nlookup.h>
56 #include <sys/pioctl.h>
57 #include <sys/systm.h>
58 #include <sys/acct.h>
59 #include <sys/fcntl.h>
60 #include <sys/lock.h>
61 #include <sys/wait.h>
62 #include <sys/ktrace.h>
63 #include <sys/syslog.h>
64 #include <sys/stat.h>
65 #include <sys/sysent.h>
66 #include <sys/sysctl.h>
67 #include <sys/malloc.h>
68 #include <sys/interrupt.h>
69 #include <sys/unistd.h>
70 #include <sys/kern_syscall.h>
71 #include <sys/vkernel.h>
72 #include <sys/thread2.h>
73
74 #include <machine/cpu.h>
75 #include <machine/smp.h>
76
77 static int coredump(struct lwp *, int);
78 static char *expand_name(const char *, uid_t, pid_t);
79 static int dokillpg(int sig, int pgid, int all);
80 static int sig_ffs(sigset_t *set);
81 static int sigprop(int sig);
82 #ifdef SMP
83 static void signotify_remote(void *arg);
84 #endif
85 static int kern_sigtimedwait(sigset_t set, siginfo_t *info,
86 struct timespec *timeout);
87
88 static int filt_sigattach(struct knote *kn);
89 static void filt_sigdetach(struct knote *kn);
90 static int filt_signal(struct knote *kn, long hint);
91
92 struct filterops sig_filtops =
93 { 0, filt_sigattach, filt_sigdetach, filt_signal };
94
95 static int kern_logsigexit = 1;
96 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
97 &kern_logsigexit, 0,
98 "Log processes quitting on abnormal signals to syslog(3)");
99
100 /*
101 * Can process p, with pcred pc, send the signal sig to process q?
102 */
103 #define CANSIGNAL(q, sig) \
104 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \
105 ((sig) == SIGCONT && (q)->p_session == curproc->p_session))
106
107 /*
108 * Policy -- Can real uid ruid with ucred uc send a signal to process q?
109 */
110 #define CANSIGIO(ruid, uc, q) \
111 ((uc)->cr_uid == 0 || \
112 (ruid) == (q)->p_ucred->cr_ruid || \
113 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \
114 (ruid) == (q)->p_ucred->cr_uid || \
115 (uc)->cr_uid == (q)->p_ucred->cr_uid)
116
117 int sugid_coredump;
118 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
119 &sugid_coredump, 0, "Enable coredumping set user/group ID processes");
120
121 static int do_coredump = 1;
122 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
123 &do_coredump, 0, "Enable/Disable coredumps");
124
125 /*
126 * Signal properties and actions.
127 * The array below categorizes the signals and their default actions
128 * according to the following properties:
129 */
130 #define SA_KILL 0x01 /* terminates process by default */
131 #define SA_CORE 0x02 /* ditto and coredumps */
132 #define SA_STOP 0x04 /* suspend process */
133 #define SA_TTYSTOP 0x08 /* ditto, from tty */
134 #define SA_IGNORE 0x10 /* ignore by default */
135 #define SA_CONT 0x20 /* continue if suspended */
136 #define SA_CANTMASK 0x40 /* non-maskable, catchable */
137 #define SA_CKPT 0x80 /* checkpoint process */
138
139
140 static int sigproptbl[NSIG] = {
141 SA_KILL, /* SIGHUP */
142 SA_KILL, /* SIGINT */
143 SA_KILL|SA_CORE, /* SIGQUIT */
144 SA_KILL|SA_CORE, /* SIGILL */
145 SA_KILL|SA_CORE, /* SIGTRAP */
146 SA_KILL|SA_CORE, /* SIGABRT */
147 SA_KILL|SA_CORE, /* SIGEMT */
148 SA_KILL|SA_CORE, /* SIGFPE */
149 SA_KILL, /* SIGKILL */
150 SA_KILL|SA_CORE, /* SIGBUS */
151 SA_KILL|SA_CORE, /* SIGSEGV */
152 SA_KILL|SA_CORE, /* SIGSYS */
153 SA_KILL, /* SIGPIPE */
154 SA_KILL, /* SIGALRM */
155 SA_KILL, /* SIGTERM */
156 SA_IGNORE, /* SIGURG */
157 SA_STOP, /* SIGSTOP */
158 SA_STOP|SA_TTYSTOP, /* SIGTSTP */
159 SA_IGNORE|SA_CONT, /* SIGCONT */
160 SA_IGNORE, /* SIGCHLD */
161 SA_STOP|SA_TTYSTOP, /* SIGTTIN */
162 SA_STOP|SA_TTYSTOP, /* SIGTTOU */
163 SA_IGNORE, /* SIGIO */
164 SA_KILL, /* SIGXCPU */
165 SA_KILL, /* SIGXFSZ */
166 SA_KILL, /* SIGVTALRM */
167 SA_KILL, /* SIGPROF */
168 SA_IGNORE, /* SIGWINCH */
169 SA_IGNORE, /* SIGINFO */
170 SA_KILL, /* SIGUSR1 */
171 SA_KILL, /* SIGUSR2 */
172 SA_IGNORE, /* SIGTHR */
173 SA_CKPT, /* SIGCKPT */
174 SA_KILL|SA_CKPT, /* SIGCKPTEXIT */
175 SA_IGNORE,
176 SA_IGNORE,
177 SA_IGNORE,
178 SA_IGNORE,
179 SA_IGNORE,
180 SA_IGNORE,
181 SA_IGNORE,
182 SA_IGNORE,
183 SA_IGNORE,
184 SA_IGNORE,
185 SA_IGNORE,
186 SA_IGNORE,
187 SA_IGNORE,
188 SA_IGNORE,
189 SA_IGNORE,
190 SA_IGNORE,
191 SA_IGNORE,
192 SA_IGNORE,
193 SA_IGNORE,
194 SA_IGNORE,
195 SA_IGNORE,
196 SA_IGNORE,
197 SA_IGNORE,
198 SA_IGNORE,
199 SA_IGNORE,
200 SA_IGNORE,
201 SA_IGNORE,
202 SA_IGNORE,
203 SA_IGNORE,
204 SA_IGNORE,
205
206 };
207
208 static __inline int
209 sigprop(int sig)
210 {
211
212 if (sig > 0 && sig < NSIG)
213 return (sigproptbl[_SIG_IDX(sig)]);
214 return (0);
215 }
216
217 static __inline int
218 sig_ffs(sigset_t *set)
219 {
220 int i;
221
222 for (i = 0; i < _SIG_WORDS; i++)
223 if (set->__bits[i])
224 return (ffs(set->__bits[i]) + (i * 32));
225 return (0);
226 }
227
228 int
229 kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact)
230 {
231 struct thread *td = curthread;
232 struct proc *p = td->td_proc;
233 struct lwp *lp;
234 struct sigacts *ps = p->p_sigacts;
235
236 if (sig <= 0 || sig > _SIG_MAXSIG)
237 return (EINVAL);
238
239 if (oact) {
240 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
241 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
242 oact->sa_flags = 0;
243 if (SIGISMEMBER(ps->ps_sigonstack, sig))
244 oact->sa_flags |= SA_ONSTACK;
245 if (!SIGISMEMBER(ps->ps_sigintr, sig))
246 oact->sa_flags |= SA_RESTART;
247 if (SIGISMEMBER(ps->ps_sigreset, sig))
248 oact->sa_flags |= SA_RESETHAND;
249 if (SIGISMEMBER(ps->ps_signodefer, sig))
250 oact->sa_flags |= SA_NODEFER;
251 if (SIGISMEMBER(ps->ps_siginfo, sig))
252 oact->sa_flags |= SA_SIGINFO;
253 if (SIGISMEMBER(ps->ps_sigmailbox, sig))
254 oact->sa_flags |= SA_MAILBOX;
255 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDSTOP)
256 oact->sa_flags |= SA_NOCLDSTOP;
257 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDWAIT)
258 oact->sa_flags |= SA_NOCLDWAIT;
259 }
260 if (act) {
261 /*
262 * Check for invalid requests. KILL and STOP cannot be
263 * caught.
264 */
265 if (sig == SIGKILL || sig == SIGSTOP) {
266 if (act->sa_handler != SIG_DFL)
267 return (EINVAL);
268 #if 0
269 /* (not needed, SIG_DFL forces action to occur) */
270 if (act->sa_flags & SA_MAILBOX)
271 return (EINVAL);
272 #endif
273 }
274
275 /*
276 * Change setting atomically.
277 */
278 crit_enter();
279
280 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
281 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
282 if (act->sa_flags & SA_SIGINFO) {
283 ps->ps_sigact[_SIG_IDX(sig)] =
284 (__sighandler_t *)act->sa_sigaction;
285 SIGADDSET(ps->ps_siginfo, sig);
286 } else {
287 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
288 SIGDELSET(ps->ps_siginfo, sig);
289 }
290 if (!(act->sa_flags & SA_RESTART))
291 SIGADDSET(ps->ps_sigintr, sig);
292 else
293 SIGDELSET(ps->ps_sigintr, sig);
294 if (act->sa_flags & SA_ONSTACK)
295 SIGADDSET(ps->ps_sigonstack, sig);
296 else
297 SIGDELSET(ps->ps_sigonstack, sig);
298 if (act->sa_flags & SA_RESETHAND)
299 SIGADDSET(ps->ps_sigreset, sig);
300 else
301 SIGDELSET(ps->ps_sigreset, sig);
302 if (act->sa_flags & SA_NODEFER)
303 SIGADDSET(ps->ps_signodefer, sig);
304 else
305 SIGDELSET(ps->ps_signodefer, sig);
306 if (act->sa_flags & SA_MAILBOX)
307 SIGADDSET(ps->ps_sigmailbox, sig);
308 else
309 SIGDELSET(ps->ps_sigmailbox, sig);
310 if (sig == SIGCHLD) {
311 if (act->sa_flags & SA_NOCLDSTOP)
312 p->p_sigacts->ps_flag |= PS_NOCLDSTOP;
313 else
314 p->p_sigacts->ps_flag &= ~PS_NOCLDSTOP;
315 if (act->sa_flags & SA_NOCLDWAIT) {
316 /*
317 * Paranoia: since SA_NOCLDWAIT is implemented
318 * by reparenting the dying child to PID 1 (and
319 * trust it to reap the zombie), PID 1 itself
320 * is forbidden to set SA_NOCLDWAIT.
321 */
322 if (p->p_pid == 1)
323 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
324 else
325 p->p_sigacts->ps_flag |= PS_NOCLDWAIT;
326 } else {
327 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
328 }
329 }
330 /*
331 * Set bit in p_sigignore for signals that are set to SIG_IGN,
332 * and for signals set to SIG_DFL where the default is to
333 * ignore. However, don't put SIGCONT in p_sigignore, as we
334 * have to restart the process.
335 */
336 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
337 (sigprop(sig) & SA_IGNORE &&
338 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
339 /* never to be seen again */
340 SIGDELSET(p->p_siglist, sig);
341 /*
342 * Remove the signal also from the thread lists.
343 */
344 FOREACH_LWP_IN_PROC(lp, p) {
345 SIGDELSET(lp->lwp_siglist, sig);
346 }
347 if (sig != SIGCONT)
348 /* easier in ksignal */
349 SIGADDSET(p->p_sigignore, sig);
350 SIGDELSET(p->p_sigcatch, sig);
351 } else {
352 SIGDELSET(p->p_sigignore, sig);
353 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
354 SIGDELSET(p->p_sigcatch, sig);
355 else
356 SIGADDSET(p->p_sigcatch, sig);
357 }
358
359 crit_exit();
360 }
361 return (0);
362 }
363
364 int
365 sys_sigaction(struct sigaction_args *uap)
366 {
367 struct sigaction act, oact;
368 struct sigaction *actp, *oactp;
369 int error;
370
371 actp = (uap->act != NULL) ? &act : NULL;
372 oactp = (uap->oact != NULL) ? &oact : NULL;
373 if (actp) {
374 error = copyin(uap->act, actp, sizeof(act));
375 if (error)
376 return (error);
377 }
378 error = kern_sigaction(uap->sig, actp, oactp);
379 if (oactp && !error) {
380 error = copyout(oactp, uap->oact, sizeof(oact));
381 }
382 return (error);
383 }
384
385 /*
386 * Initialize signal state for process 0;
387 * set to ignore signals that are ignored by default.
388 */
389 void
390 siginit(struct proc *p)
391 {
392 int i;
393
394 for (i = 1; i <= NSIG; i++)
395 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
396 SIGADDSET(p->p_sigignore, i);
397 }
398
399 /*
400 * Reset signals for an exec of the specified process.
401 */
402 void
403 execsigs(struct proc *p)
404 {
405 struct sigacts *ps = p->p_sigacts;
406 struct lwp *lp;
407 int sig;
408
409 lp = ONLY_LWP_IN_PROC(p);
410
411 /*
412 * Reset caught signals. Held signals remain held
413 * through p_sigmask (unless they were caught,
414 * and are now ignored by default).
415 */
416 while (SIGNOTEMPTY(p->p_sigcatch)) {
417 sig = sig_ffs(&p->p_sigcatch);
418 SIGDELSET(p->p_sigcatch, sig);
419 if (sigprop(sig) & SA_IGNORE) {
420 if (sig != SIGCONT)
421 SIGADDSET(p->p_sigignore, sig);
422 SIGDELSET(p->p_siglist, sig);
423 SIGDELSET(lp->lwp_siglist, sig);
424 }
425 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
426 }
427
428 /*
429 * Reset stack state to the user stack.
430 * Clear set of signals caught on the signal stack.
431 */
432 lp->lwp_sigstk.ss_flags = SS_DISABLE;
433 lp->lwp_sigstk.ss_size = 0;
434 lp->lwp_sigstk.ss_sp = 0;
435 lp->lwp_flag &= ~LWP_ALTSTACK;
436 /*
437 * Reset no zombies if child dies flag as Solaris does.
438 */
439 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
440 }
441
442 /*
443 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
444 *
445 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
446 * p == curproc.
447 */
448 int
449 kern_sigprocmask(int how, sigset_t *set, sigset_t *oset)
450 {
451 struct thread *td = curthread;
452 struct lwp *lp = td->td_lwp;
453 int error;
454
455 if (oset != NULL)
456 *oset = lp->lwp_sigmask;
457
458 error = 0;
459 if (set != NULL) {
460 switch (how) {
461 case SIG_BLOCK:
462 SIG_CANTMASK(*set);
463 SIGSETOR(lp->lwp_sigmask, *set);
464 break;
465 case SIG_UNBLOCK:
466 SIGSETNAND(lp->lwp_sigmask, *set);
467 break;
468 case SIG_SETMASK:
469 SIG_CANTMASK(*set);
470 lp->lwp_sigmask = *set;
471 break;
472 default:
473 error = EINVAL;
474 break;
475 }
476 }
477 return (error);
478 }
479
480 /*
481 * sigprocmask() - MP SAFE
482 */
483 int
484 sys_sigprocmask(struct sigprocmask_args *uap)
485 {
486 sigset_t set, oset;
487 sigset_t *setp, *osetp;
488 int error;
489
490 setp = (uap->set != NULL) ? &set : NULL;
491 osetp = (uap->oset != NULL) ? &oset : NULL;
492 if (setp) {
493 error = copyin(uap->set, setp, sizeof(set));
494 if (error)
495 return (error);
496 }
497 error = kern_sigprocmask(uap->how, setp, osetp);
498 if (osetp && !error) {
499 error = copyout(osetp, uap->oset, sizeof(oset));
500 }
501 return (error);
502 }
503
504 int
505 kern_sigpending(struct __sigset *set)
506 {
507 struct lwp *lp = curthread->td_lwp;
508
509 *set = lwp_sigpend(lp);
510
511 return (0);
512 }
513
514 int
515 sys_sigpending(struct sigpending_args *uap)
516 {
517 sigset_t set;
518 int error;
519
520 error = kern_sigpending(&set);
521
522 if (error == 0)
523 error = copyout(&set, uap->set, sizeof(set));
524 return (error);
525 }
526
527 /*
528 * Suspend process until signal, providing mask to be set
529 * in the meantime.
530 */
531 int
532 kern_sigsuspend(struct __sigset *set)
533 {
534 struct thread *td = curthread;
535 struct lwp *lp = td->td_lwp;
536 struct proc *p = td->td_proc;
537 struct sigacts *ps = p->p_sigacts;
538
539 /*
540 * When returning from sigsuspend, we want
541 * the old mask to be restored after the
542 * signal handler has finished. Thus, we
543 * save it here and mark the sigacts structure
544 * to indicate this.
545 */
546 lp->lwp_oldsigmask = lp->lwp_sigmask;
547 lp->lwp_flag |= LWP_OLDMASK;
548
549 SIG_CANTMASK(*set);
550 lp->lwp_sigmask = *set;
551 while (tsleep(ps, PCATCH, "pause", 0) == 0)
552 /* void */;
553 /* always return EINTR rather than ERESTART... */
554 return (EINTR);
555 }
556
557 /*
558 * Note nonstandard calling convention: libc stub passes mask, not
559 * pointer, to save a copyin.
560 */
561 int
562 sys_sigsuspend(struct sigsuspend_args *uap)
563 {
564 sigset_t mask;
565 int error;
566
567 error = copyin(uap->sigmask, &mask, sizeof(mask));
568 if (error)
569 return (error);
570
571 error = kern_sigsuspend(&mask);
572
573 return (error);
574 }
575
576 int
577 kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss)
578 {
579 struct thread *td = curthread;
580 struct lwp *lp = td->td_lwp;
581 struct proc *p = td->td_proc;
582
583 if ((lp->lwp_flag & LWP_ALTSTACK) == 0)
584 lp->lwp_sigstk.ss_flags |= SS_DISABLE;
585
586 if (oss)
587 *oss = lp->lwp_sigstk;
588
589 if (ss) {
590 if (ss->ss_flags & SS_DISABLE) {
591 if (lp->lwp_sigstk.ss_flags & SS_ONSTACK)
592 return (EINVAL);
593 lp->lwp_flag &= ~LWP_ALTSTACK;
594 lp->lwp_sigstk.ss_flags = ss->ss_flags;
595 } else {
596 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
597 return (ENOMEM);
598 lp->lwp_flag |= LWP_ALTSTACK;
599 lp->lwp_sigstk = *ss;
600 }
601 }
602
603 return (0);
604 }
605
606 int
607 sys_sigaltstack(struct sigaltstack_args *uap)
608 {
609 stack_t ss, oss;
610 int error;
611
612 if (uap->ss) {
613 error = copyin(uap->ss, &ss, sizeof(ss));
614 if (error)
615 return (error);
616 }
617
618 error = kern_sigaltstack(uap->ss ? &ss : NULL,
619 uap->oss ? &oss : NULL);
620
621 if (error == 0 && uap->oss)
622 error = copyout(&oss, uap->oss, sizeof(*uap->oss));
623 return (error);
624 }
625
626 /*
627 * Common code for kill process group/broadcast kill.
628 * cp is calling process.
629 */
630 struct killpg_info {
631 int nfound;
632 int sig;
633 };
634
635 static int killpg_all_callback(struct proc *p, void *data);
636
637 static int
638 dokillpg(int sig, int pgid, int all)
639 {
640 struct killpg_info info;
641 struct proc *cp = curproc;
642 struct proc *p;
643 struct pgrp *pgrp;
644
645 info.nfound = 0;
646 info.sig = sig;
647
648 if (all) {
649 /*
650 * broadcast
651 */
652 allproc_scan(killpg_all_callback, &info);
653 } else {
654 if (pgid == 0) {
655 /*
656 * zero pgid means send to my process group.
657 */
658 pgrp = cp->p_pgrp;
659 } else {
660 pgrp = pgfind(pgid);
661 if (pgrp == NULL)
662 return (ESRCH);
663 }
664 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
665 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
666 if (p->p_pid <= 1 ||
667 p->p_stat == SZOMB ||
668 (p->p_flag & P_SYSTEM) ||
669 !CANSIGNAL(p, sig)) {
670 continue;
671 }
672 ++info.nfound;
673 if (sig)
674 ksignal(p, sig);
675 }
676 lockmgr(&pgrp->pg_lock, LK_RELEASE);
677 }
678 return (info.nfound ? 0 : ESRCH);
679 }
680
681 static int
682 killpg_all_callback(struct proc *p, void *data)
683 {
684 struct killpg_info *info = data;
685
686 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) ||
687 p == curproc || !CANSIGNAL(p, info->sig)) {
688 return (0);
689 }
690 ++info->nfound;
691 if (info->sig)
692 ksignal(p, info->sig);
693 return(0);
694 }
695
696 int
697 kern_kill(int sig, pid_t pid, lwpid_t tid)
698 {
699 struct thread *td = curthread;
700 struct proc *p = td->td_proc;
701 struct lwp *lp = NULL;
702
703 if ((u_int)sig > _SIG_MAXSIG)
704 return (EINVAL);
705 if (pid > 0) {
706 /* kill single process */
707 if ((p = pfind(pid)) == NULL)
708 return (ESRCH);
709 if (!CANSIGNAL(p, sig))
710 return (EPERM);
711 if (tid != -1) {
712 FOREACH_LWP_IN_PROC(lp, p) {
713 if (lp->lwp_tid == tid)
714 break;
715 }
716 if (lp == NULL)
717 return (ESRCH);
718 }
719 if (sig)
720 lwpsignal(p, lp, sig);
721 return (0);
722 }
723 /*
724 * If we come here, pid is a special broadcast pid.
725 * This doesn't mix with a tid.
726 */
727 if (tid != -1)
728 return (EINVAL);
729 switch (pid) {
730 case -1: /* broadcast signal */
731 return (dokillpg(sig, 0, 1));
732 case 0: /* signal own process group */
733 return (dokillpg(sig, 0, 0));
734 default: /* negative explicit process group */
735 return (dokillpg(sig, -pid, 0));
736 }
737 /* NOTREACHED */
738 }
739
740 int
741 sys_kill(struct kill_args *uap)
742 {
743 int error;
744
745 error = kern_kill(uap->signum, uap->pid, -1);
746 return (error);
747 }
748
749 int
750 sys_lwp_kill(struct lwp_kill_args *uap)
751 {
752 int error;
753 pid_t pid = uap->pid;
754
755 /*
756 * A tid is mandatory for lwp_kill(), otherwise
757 * you could simply use kill().
758 */
759 if (uap->tid == -1)
760 return (EINVAL);
761
762 /*
763 * To save on a getpid() function call for intra-process
764 * signals, pid == -1 means current process.
765 */
766 if (pid == -1)
767 pid = curproc->p_pid;
768
769 error = kern_kill(uap->signum, pid, uap->tid);
770 return (error);
771 }
772
773 /*
774 * Send a signal to a process group.
775 */
776 void
777 gsignal(int pgid, int sig)
778 {
779 struct pgrp *pgrp;
780
781 if (pgid && (pgrp = pgfind(pgid)))
782 pgsignal(pgrp, sig, 0);
783 }
784
785 /*
786 * Send a signal to a process group. If checktty is 1,
787 * limit to members which have a controlling terminal.
788 *
789 * pg_lock interlocks against a fork that might be in progress, to
790 * ensure that the new child process picks up the signal.
791 */
792 void
793 pgsignal(struct pgrp *pgrp, int sig, int checkctty)
794 {
795 struct proc *p;
796
797 if (pgrp) {
798 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
799 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
800 if (checkctty == 0 || p->p_flag & P_CONTROLT)
801 ksignal(p, sig);
802 }
803 lockmgr(&pgrp->pg_lock, LK_RELEASE);
804 }
805 }
806
807 /*
808 * Send a signal caused by a trap to the current process.
809 * If it will be caught immediately, deliver it with correct code.
810 * Otherwise, post it normally.
811 */
812 void
813 trapsignal(struct lwp *lp, int sig, u_long code)
814 {
815 struct proc *p = lp->lwp_proc;
816 struct sigacts *ps = p->p_sigacts;
817
818 /*
819 * If we are a virtual kernel running an emulated user process
820 * context, switch back to the virtual kernel context before
821 * trying to post the signal.
822 */
823 if (p->p_vkernel && p->p_vkernel->vk_current) {
824 struct trapframe *tf = curthread->td_lwp->lwp_md.md_regs;
825 tf->tf_trapno = 0;
826 vkernel_trap(p, tf);
827 }
828
829
830 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
831 !SIGISMEMBER(lp->lwp_sigmask, sig)) {
832 lp->lwp_ru.ru_nsignals++;
833 #ifdef KTRACE
834 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
835 ktrpsig(p, sig, ps->ps_sigact[_SIG_IDX(sig)],
836 &lp->lwp_sigmask, code);
837 #endif
838 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
839 &lp->lwp_sigmask, code);
840 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
841 if (!SIGISMEMBER(ps->ps_signodefer, sig))
842 SIGADDSET(lp->lwp_sigmask, sig);
843 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
844 /*
845 * See kern_sigaction() for origin of this code.
846 */
847 SIGDELSET(p->p_sigcatch, sig);
848 if (sig != SIGCONT &&
849 sigprop(sig) & SA_IGNORE)
850 SIGADDSET(p->p_sigignore, sig);
851 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
852 }
853 } else {
854 lp->lwp_code = code; /* XXX for core dump/debugger */
855 lp->lwp_sig = sig; /* XXX to verify code */
856 lwpsignal(p, lp, sig);
857 }
858 }
859
860 /*
861 * Find a suitable lwp to deliver the signal to.
862 *
863 * Returns NULL if all lwps hold the signal blocked.
864 */
865 static struct lwp *
866 find_lwp_for_signal(struct proc *p, int sig)
867 {
868 struct lwp *lp;
869 struct lwp *run, *sleep, *stop;
870
871 /*
872 * If the running/preempted thread belongs to the proc to which
873 * the signal is being delivered and this thread does not block
874 * the signal, then we can avoid a context switch by delivering
875 * the signal to this thread, because it will return to userland
876 * soon anyways.
877 */
878 lp = lwkt_preempted_proc();
879 if (lp != NULL && lp->lwp_proc == p && !SIGISMEMBER(lp->lwp_sigmask, sig))
880 return (lp);
881
882 run = sleep = stop = NULL;
883 FOREACH_LWP_IN_PROC(lp, p) {
884 /*
885 * If the signal is being blocked by the lwp, then this
886 * lwp is not eligible for receiving the signal.
887 */
888 if (SIGISMEMBER(lp->lwp_sigmask, sig))
889 continue;
890
891 switch (lp->lwp_stat) {
892 case LSRUN:
893 run = lp;
894 break;
895
896 case LSSTOP:
897 stop = lp;
898 break;
899
900 case LSSLEEP:
901 if (lp->lwp_flag & LWP_SINTR)
902 sleep = lp;
903 break;
904 }
905 }
906
907 if (run != NULL)
908 return (run);
909 else if (sleep != NULL)
910 return (sleep);
911 else
912 return (stop);
913 }
914
915 /*
916 * Send the signal to the process. If the signal has an action, the action
917 * is usually performed by the target process rather than the caller; we add
918 * the signal to the set of pending signals for the process.
919 *
920 * Exceptions:
921 * o When a stop signal is sent to a sleeping process that takes the
922 * default action, the process is stopped without awakening it.
923 * o SIGCONT restarts stopped processes (or puts them back to sleep)
924 * regardless of the signal action (eg, blocked or ignored).
925 *
926 * Other ignored signals are discarded immediately.
927 */
928 void
929 ksignal(struct proc *p, int sig)
930 {
931 lwpsignal(p, NULL, sig);
932 }
933
934 /*
935 * The core for ksignal. lp may be NULL, then a suitable thread
936 * will be chosen. If not, lp MUST be a member of p.
937 */
938 void
939 lwpsignal(struct proc *p, struct lwp *lp, int sig)
940 {
941 int prop;
942 sig_t action;
943
944 if (sig > _SIG_MAXSIG || sig <= 0) {
945 kprintf("lwpsignal: signal %d\n", sig);
946 panic("lwpsignal signal number");
947 }
948
949 KKASSERT(lp == NULL || lp->lwp_proc == p);
950
951 crit_enter();
952 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
953 crit_exit();
954
955 prop = sigprop(sig);
956
957 /*
958 * If proc is traced, always give parent a chance;
959 * if signal event is tracked by procfs, give *that*
960 * a chance, as well.
961 */
962 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) {
963 action = SIG_DFL;
964 } else {
965 /*
966 * Do not try to deliver signals to an exiting process or
967 * exiting lwp.
968 */
969 if (p->p_flag & P_WEXIT)
970 return;
971 if (lp && (lp->lwp_flag & LWP_WEXIT))
972 return;
973
974 /*
975 * Ig the signal is being ignored, then we forget about
976 * it immediately. NOTE: We don't set SIGCONT in p_sigignore,
977 * and if it is set to SIG_IGN, action will be SIG_DFL here.
978 */
979 if (SIGISMEMBER(p->p_sigignore, sig))
980 return;
981 if (SIGISMEMBER(p->p_sigcatch, sig))
982 action = SIG_CATCH;
983 else
984 action = SIG_DFL;
985 }
986
987 /*
988 * If continuing, clear any pending STOP signals.
989 */
990 if (prop & SA_CONT)
991 SIG_STOPSIGMASK(p->p_siglist);
992
993 if (prop & SA_STOP) {
994 /*
995 * If sending a tty stop signal to a member of an orphaned
996 * process group, discard the signal here if the action
997 * is default; don't stop the process below if sleeping,
998 * and don't clear any pending SIGCONT.
999 */
1000 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
1001 action == SIG_DFL) {
1002 return;
1003 }
1004 SIG_CONTSIGMASK(p->p_siglist);
1005 }
1006
1007 crit_enter();
1008
1009 if (p->p_stat == SSTOP) {
1010 /*
1011 * Nobody can handle this signal, so add it to the process
1012 * pending list.
1013 */
1014 SIGADDSET(p->p_siglist, sig);
1015
1016 /*
1017 * If the process is stopped and is being traced, then no
1018 * further action is necessary.
1019 */
1020 if (p->p_flag & P_TRACED)
1021 goto out;
1022
1023 /*
1024 * If the process is stopped and receives a KILL signal,
1025 * make the process runnable.
1026 */
1027 if (sig == SIGKILL) {
1028 proc_unstop(p);
1029 goto active_process;
1030 }
1031
1032 /*
1033 * If the process is stopped and receives a CONT signal,
1034 * then try to make the process runnable again.
1035 */
1036 if (prop & SA_CONT) {
1037 /*
1038 * If SIGCONT is default (or ignored), we continue the
1039 * process but don't leave the signal in p_siglist, as
1040 * it has no further action. If SIGCONT is held, we
1041 * continue the process and leave the signal in
1042 * p_siglist. If the process catches SIGCONT, let it
1043 * handle the signal itself.
1044 */
1045 /* XXX what if the signal is being held blocked? */
1046 if (action == SIG_DFL)
1047 SIGDELSET(p->p_siglist, sig);
1048 proc_unstop(p);
1049 if (action == SIG_CATCH)
1050 goto active_process;
1051 goto out;
1052 }
1053
1054 /*
1055 * If the process is stopped and receives another STOP
1056 * signal, we do not need to stop it again. If we did
1057 * the shell could get confused.
1058 *
1059 * However, if the current/preempted lwp is part of the
1060 * process receiving the signal, we need to keep it,
1061 * so that this lwp can stop in issignal() later, as
1062 * we don't want to wait until it reaches userret!
1063 */
1064 if (prop & SA_STOP) {
1065 if (lwkt_preempted_proc() == NULL ||
1066 lwkt_preempted_proc()->lwp_proc != p)
1067 SIGDELSET(p->p_siglist, sig);
1068 }
1069
1070 /*
1071 * Otherwise the process is stopped and it received some
1072 * signal, which does not change its stopped state.
1073 *
1074 * We have to select one thread to set LWP_BREAKTSLEEP,
1075 * so that the current signal will break the sleep
1076 * as soon as a SA_CONT signal will unstop the process.
1077 */
1078 if (lp == NULL)
1079 lp = find_lwp_for_signal(p, sig);
1080 if (lp != NULL &&
1081 (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP))
1082 lp->lwp_flag |= LWP_BREAKTSLEEP;
1083 goto out;
1084
1085 /* NOTREACHED */
1086 }
1087 /* else not stopped */
1088 active_process:
1089
1090 if (lp == NULL)
1091 lp = find_lwp_for_signal(p, sig);
1092
1093 /*
1094 * If lp == NULL, there is no thread available which does
1095 * not block the signal. If lp is set, it might be a thread
1096 * specific signal, so we have to check for the thread ignoring
1097 * the signal.
1098 *
1099 * If so, defer further processing for this signal.
1100 * Add the signal to the process pending list.
1101 */
1102 if (lp == NULL || SIGISMEMBER(lp->lwp_sigmask, sig)) {
1103 SIGADDSET(p->p_siglist, sig);
1104 goto out;
1105 }
1106 /* else we have a lwp to deliver the signal to */
1107
1108 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
1109 (p->p_flag & P_TRACED) == 0) {
1110 p->p_nice = NZERO;
1111 }
1112
1113 /*
1114 * If the process receives a STOP signal which indeed needs to
1115 * stop the process, do so. If the process chose to catch the
1116 * signal, it will be treated like any other signal.
1117 */
1118 if ((prop & SA_STOP) && action == SIG_DFL) {
1119 /*
1120 * If a child holding parent blocked, stopping
1121 * could cause deadlock. Take no action at this
1122 * time.
1123 */
1124 if (p->p_flag & P_PPWAIT) {
1125 SIGADDSET(p->p_siglist, sig);
1126 goto out;
1127 }
1128
1129 /*
1130 * Do not actually try to manipulate the process, but simply
1131 * stop it. Lwps will stop as soon as they safely can.
1132 */
1133 p->p_xstat = sig;
1134 proc_stop(p);
1135 goto out;
1136 }
1137
1138 /*
1139 * If it is a CONT signal with default action, just ignore it.
1140 */
1141 if ((prop & SA_CONT) && action == SIG_DFL)
1142 goto out;
1143
1144 /*
1145 * Mark signal pending at this specific thread.
1146 */
1147 SIGADDSET(lp->lwp_siglist, sig);
1148
1149 lwp_signotify(lp);
1150
1151 out:
1152 crit_exit();
1153 }
1154
1155 void
1156 lwp_signotify(struct lwp *lp)
1157 {
1158 crit_enter();
1159 if (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP) {
1160 /*
1161 * Thread is in tsleep.
1162 */
1163
1164 /*
1165 * If the thread is sleeping uninterruptibly
1166 * we can't interrupt the sleep... the signal will
1167 * be noticed when the lwp returns through
1168 * trap() or syscall().
1169 *
1170 * Otherwise the signal can interrupt the sleep.
1171 *
1172 * If the process is traced, the lwp will handle the
1173 * tracing in issignal() when it returns to userland.
1174 */
1175 if (lp->lwp_flag & LWP_SINTR) {
1176 /*
1177 * Make runnable and break out of any tsleep as well.
1178 */
1179 lp->lwp_flag |= LWP_BREAKTSLEEP;
1180 setrunnable(lp);
1181 }
1182 } else {
1183 /*
1184 * Otherwise the thread is running
1185 *
1186 * LSRUN does nothing with the signal, other than kicking
1187 * ourselves if we are running.
1188 * SZOMB and SIDL mean that it will either never be noticed,
1189 * or noticed very soon.
1190 *
1191 * Note that lwp_thread may be NULL or may not be completely
1192 * initialized if the process is in the SIDL or SZOMB state.
1193 *
1194 * For SMP we may have to forward the request to another cpu.
1195 * YYY the MP lock prevents the target process from moving
1196 * to another cpu, see kern/kern_switch.c
1197 *
1198 * If the target thread is waiting on its message port,
1199 * wakeup the target thread so it can check (or ignore)
1200 * the new signal. YYY needs cleanup.
1201 */
1202 if (lp == lwkt_preempted_proc()) {
1203 signotify();
1204 } else if (lp->lwp_stat == LSRUN) {
1205 struct thread *td = lp->lwp_thread;
1206 struct proc *p = lp->lwp_proc;
1207
1208 KASSERT(td != NULL,
1209 ("pid %d/%d NULL lwp_thread stat %d flags %08x/%08x",
1210 p->p_pid, lp->lwp_tid, lp->lwp_stat,
1211 p->p_flag, lp->lwp_flag));
1212
1213 /*
1214 * To prevent a MP race with TDF_SINTR we must
1215 * schedule the thread on the correct cpu.
1216 */
1217 #ifdef SMP
1218 if (td->td_gd != mycpu)
1219 lwkt_send_ipiq(td->td_gd, signotify_remote, lp);
1220 else
1221 #endif
1222 if (td->td_flags & TDF_SINTR)
1223 lwkt_schedule(td);
1224 }
1225 }
1226 crit_exit();
1227 }
1228
1229 #ifdef SMP
1230
1231 /*
1232 * This function is called via an IPI. We will be in a critical section but
1233 * the MP lock will NOT be held. Also note that by the time the ipi message
1234 * gets to us the process 'p' (arg) may no longer be scheduled or even valid.
1235 */
1236 static void
1237 signotify_remote(void *arg)
1238 {
1239 struct lwp *lp = arg;
1240
1241 if (lp == lwkt_preempted_proc()) {
1242 signotify();
1243 } else {
1244 struct thread *td = lp->lwp_thread;
1245 if (td->td_flags & TDF_SINTR)
1246 lwkt_schedule(td);
1247 }
1248 }
1249
1250 #endif
1251
1252 void
1253 proc_stop(struct proc *p)
1254 {
1255 struct lwp *lp;
1256
1257 /* If somebody raced us, be happy with it */
1258 if (p->p_stat == SSTOP)
1259 return;
1260
1261 crit_enter();
1262 p->p_stat = SSTOP;
1263
1264 FOREACH_LWP_IN_PROC(lp, p) {
1265 switch (lp->lwp_stat) {
1266 case LSSTOP:
1267 /*
1268 * Do nothing, we are already counted in
1269 * p_nstopped.
1270 */
1271 break;
1272
1273 case LSSLEEP:
1274 /*
1275 * We're sleeping, but we will stop before
1276 * returning to userspace, so count us
1277 * as stopped as well. We set LWP_WSTOP
1278 * to signal the lwp that it should not
1279 * increase p_nstopped when reaching tstop().
1280 */
1281 if ((lp->lwp_flag & LWP_WSTOP) == 0) {
1282 lp->lwp_flag |= LWP_WSTOP;
1283 ++p->p_nstopped;
1284 }
1285 break;
1286
1287 case LSRUN:
1288 /*
1289 * We might notify ourself, but that's not
1290 * a problem.
1291 */
1292 lwp_signotify(lp);
1293 break;
1294 }
1295 }
1296
1297 if (p->p_nstopped == p->p_nthreads) {
1298 p->p_flag &= ~P_WAITED;
1299 wakeup(p->p_pptr);
1300 if ((p->p_pptr->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1301 ksignal(p->p_pptr, SIGCHLD);
1302 }
1303 crit_exit();
1304 }
1305
1306 void
1307 proc_unstop(struct proc *p)
1308 {
1309 struct lwp *lp;
1310
1311 if (p->p_stat != SSTOP)
1312 return;
1313
1314 crit_enter();
1315 p->p_stat = SACTIVE;
1316
1317 FOREACH_LWP_IN_PROC(lp, p) {
1318 switch (lp->lwp_stat) {
1319 case LSRUN:
1320 /*
1321 * Uh? Not stopped? Well, I guess that's okay.
1322 */
1323 if (bootverbose)
1324 kprintf("proc_unstop: lwp %d/%d not sleeping\n",
1325 p->p_pid, lp->lwp_tid);
1326 break;
1327
1328 case LSSLEEP:
1329 /*
1330 * Still sleeping. Don't bother waking it up.
1331 * However, if this thread was counted as
1332 * stopped, undo this.
1333 *
1334 * Nevertheless we call setrunnable() so that it
1335 * will wake up in case a signal or timeout arrived
1336 * in the meantime.
1337 */
1338 if (lp->lwp_flag & LWP_WSTOP) {
1339 --p->p_nstopped;
1340 } else {
1341 if (bootverbose)
1342 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n",
1343 p->p_pid, lp->lwp_tid);
1344 }
1345 /* FALLTHROUGH */
1346
1347 case LSSTOP:
1348 setrunnable(lp);
1349 break;
1350
1351 }
1352 lp->lwp_flag &= ~LWP_WSTOP;
1353 }
1354 crit_exit();
1355 }
1356
1357 static int
1358 kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout)
1359 {
1360 sigset_t savedmask, set;
1361 struct proc *p = curproc;
1362 struct lwp *lp = curthread->td_lwp;
1363 int error, sig, hz, timevalid = 0;
1364 struct timespec rts, ets, ts;
1365 struct timeval tv;
1366
1367 error = 0;
1368 sig = 0;
1369 SIG_CANTMASK(waitset);
1370 savedmask = lp->lwp_sigmask;
1371
1372 if (timeout) {
1373 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 &&
1374 timeout->tv_nsec < 1000000000) {
1375 timevalid = 1;
1376 getnanouptime(&rts);
1377 ets = rts;
1378 timespecadd(&ets, timeout);
1379 }
1380 }
1381
1382 for (;;) {
1383 set = lwp_sigpend(lp);
1384 SIGSETAND(set, waitset);
1385 if ((sig = sig_ffs(&set)) != 0) {
1386 SIGFILLSET(lp->lwp_sigmask);
1387 SIGDELSET(lp->lwp_sigmask, sig);
1388 SIG_CANTMASK(lp->lwp_sigmask);
1389 sig = issignal(lp);
1390 /*
1391 * It may be a STOP signal, in the case, issignal
1392 * returns 0, because we may stop there, and new
1393 * signal can come in, we should restart if we got
1394 * nothing.
1395 */
1396 if (sig == 0)
1397 continue;
1398 else
1399 break;
1400 }
1401
1402 /*
1403 * Previous checking got nothing, and we retried but still
1404 * got nothing, we should return the error status.
1405 */
1406 if (error)
1407 break;
1408
1409 /*
1410 * POSIX says this must be checked after looking for pending
1411 * signals.
1412 */
1413 if (timeout) {
1414 if (!timevalid) {
1415 error = EINVAL;
1416 break;
1417 }
1418 getnanouptime(&rts);
1419 if (timespeccmp(&rts, &ets, >=)) {
1420 error = EAGAIN;
1421 break;
1422 }
1423 ts = ets;
1424 timespecsub(&ts, &rts);
1425 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1426 hz = tvtohz_high(&tv);
1427 } else
1428 hz = 0;
1429
1430 lp->lwp_sigmask = savedmask;
1431 SIGSETNAND(lp->lwp_sigmask, waitset);
1432 /*
1433 * We won't ever be woken up. Instead, our sleep will
1434 * be broken in lwpsignal().
1435 */
1436 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz);
1437 if (timeout) {
1438 if (error == ERESTART) {
1439 /* can not restart a timeout wait. */
1440 error = EINTR;
1441 } else if (error == EAGAIN) {
1442 /* will calculate timeout by ourself. */
1443 error = 0;
1444 }
1445 }
1446 /* Retry ... */
1447 }
1448
1449 lp->lwp_sigmask = savedmask;
1450 if (sig) {
1451 error = 0;
1452 bzero(info, sizeof(*info));
1453 info->si_signo = sig;
1454 lwp_delsig(lp, sig); /* take the signal! */
1455
1456 if (sig == SIGKILL)
1457 sigexit(p, sig);
1458 }
1459 return (error);
1460 }
1461
1462 int
1463 sys_sigtimedwait(struct sigtimedwait_args *uap)
1464 {
1465 struct timespec ts;
1466 struct timespec *timeout;
1467 sigset_t set;
1468 siginfo_t info;
1469 int error;
1470
1471 if (uap->timeout) {
1472 error = copyin(uap->timeout, &ts, sizeof(ts));
1473 if (error)
1474 return (error);
1475 timeout = &ts;
1476 } else {
1477 timeout = NULL;
1478 }
1479 error = copyin(uap->set, &set, sizeof(set));
1480 if (error)
1481 return (error);
1482 error = kern_sigtimedwait(set, &info, timeout);
1483 if (error)
1484 return (error);
1485 if (uap->info)
1486 error = copyout(&info, uap->info, sizeof(info));
1487 /* Repost if we got an error. */
1488 /*
1489 * XXX lwp
1490 *
1491 * This could transform a thread-specific signal to another
1492 * thread / process pending signal.
1493 */
1494 if (error)
1495 ksignal(curproc, info.si_signo);
1496 else
1497 uap->sysmsg_result = info.si_signo;
1498 return (error);
1499 }
1500
1501 int
1502 sys_sigwaitinfo(struct sigwaitinfo_args *uap)
1503 {
1504 siginfo_t info;
1505 sigset_t set;
1506 int error;
1507
1508 error = copyin(uap->set, &set, sizeof(set));
1509 if (error)
1510 return (error);
1511 error = kern_sigtimedwait(set, &info, NULL);
1512 if (error)
1513 return (error);
1514 if (uap->info)
1515 error = copyout(&info, uap->info, sizeof(info));
1516 /* Repost if we got an error. */
1517 /*
1518 * XXX lwp
1519 *
1520 * This could transform a thread-specific signal to another
1521 * thread / process pending signal.
1522 */
1523 if (error)
1524 ksignal(curproc, info.si_signo);
1525 else
1526 uap->sysmsg_result = info.si_signo;
1527 return (error);
1528 }
1529
1530 /*
1531 * If the current process has received a signal that would interrupt a
1532 * system call, return EINTR or ERESTART as appropriate.
1533 */
1534 int
1535 iscaught(struct lwp *lp)
1536 {
1537 struct proc *p = lp->lwp_proc;
1538 int sig;
1539
1540 if (p) {
1541 if ((sig = CURSIG(lp)) != 0) {
1542 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1543 return (EINTR);
1544 return (ERESTART);
1545 }
1546 }
1547 return(EWOULDBLOCK);
1548 }
1549
1550 /*
1551 * If the current process has received a signal (should be caught or cause
1552 * termination, should interrupt current syscall), return the signal number.
1553 * Stop signals with default action are processed immediately, then cleared;
1554 * they aren't returned. This is checked after each entry to the system for
1555 * a syscall or trap (though this can usually be done without calling issignal
1556 * by checking the pending signal masks in the CURSIG macro.) The normal call
1557 * sequence is
1558 *
1559 * This routine is called via CURSIG/__cursig and the MP lock might not be
1560 * held. Obtain the MP lock for the duration of the operation.
1561 *
1562 * while (sig = CURSIG(curproc))
1563 * postsig(sig);
1564 */
1565 int
1566 issignal(struct lwp *lp)
1567 {
1568 struct proc *p = lp->lwp_proc;
1569 sigset_t mask;
1570 int sig, prop;
1571
1572 get_mplock();
1573 for (;;) {
1574 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
1575
1576 mask = lwp_sigpend(lp);
1577 SIGSETNAND(mask, lp->lwp_sigmask);
1578 if (p->p_flag & P_PPWAIT)
1579 SIG_STOPSIGMASK(mask);
1580 if (SIGISEMPTY(mask)) { /* no signal to send */
1581 rel_mplock();
1582 return (0);
1583 }
1584 sig = sig_ffs(&mask);
1585
1586 STOPEVENT(p, S_SIG, sig);
1587
1588 /*
1589 * We should see pending but ignored signals
1590 * only if P_TRACED was on when they were posted.
1591 */
1592 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
1593 lwp_delsig(lp, sig);
1594 continue;
1595 }
1596 if ((p->p_flag & P_TRACED) && (p->p_flag & P_PPWAIT) == 0) {
1597 /*
1598 * If traced, always stop, and stay stopped until
1599 * released by the parent.
1600 *
1601 * NOTE: SSTOP may get cleared during the loop,
1602 * but we do not re-notify the parent if we have
1603 * to loop several times waiting for the parent
1604 * to let us continue.
1605 *
1606 * XXX not sure if this is still true
1607 */
1608 p->p_xstat = sig;
1609 proc_stop(p);
1610 do {
1611 tstop();
1612 } while (!trace_req(p) && (p->p_flag & P_TRACED));
1613
1614 /*
1615 * If parent wants us to take the signal,
1616 * then it will leave it in p->p_xstat;
1617 * otherwise we just look for signals again.
1618 */
1619 lwp_delsig(lp, sig); /* clear old signal */
1620 sig = p->p_xstat;
1621 if (sig == 0)
1622 continue;
1623
1624 /*
1625 * Put the new signal into p_siglist. If the
1626 * signal is being masked, look for other signals.
1627 *
1628 * XXX lwp might need a call to ksignal()
1629 */
1630 SIGADDSET(p->p_siglist, sig);
1631 if (SIGISMEMBER(lp->lwp_sigmask, sig))
1632 continue;
1633
1634 /*
1635 * If the traced bit got turned off, go back up
1636 * to the top to rescan signals. This ensures
1637 * that p_sig* and ps_sigact are consistent.
1638 */
1639 if ((p->p_flag & P_TRACED) == 0)
1640 continue;
1641 }
1642
1643 prop = sigprop(sig);
1644
1645 /*
1646 * Decide whether the signal should be returned.
1647 * Return the signal's number, or fall through
1648 * to clear it from the pending mask.
1649 */
1650 switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
1651 case (int)SIG_DFL:
1652 /*
1653 * Don't take default actions on system processes.
1654 */
1655 if (p->p_pid <= 1) {
1656 #ifdef DIAGNOSTIC
1657 /*
1658 * Are you sure you want to ignore SIGSEGV
1659 * in init? XXX
1660 */
1661 kprintf("Process (pid %lu) got signal %d\n",
1662 (u_long)p->p_pid, sig);
1663 #endif
1664 break; /* == ignore */
1665 }
1666
1667 /*
1668 * Handle the in-kernel checkpoint action
1669 */
1670 if (prop & SA_CKPT) {
1671 checkpoint_signal_handler(lp);
1672 break;
1673 }
1674
1675 /*
1676 * If there is a pending stop signal to process
1677 * with default action, stop here,
1678 * then clear the signal. However,
1679 * if process is member of an orphaned
1680 * process group, ignore tty stop signals.
1681 */
1682 if (prop & SA_STOP) {
1683 if (p->p_flag & P_TRACED ||
1684 (p->p_pgrp->pg_jobc == 0 &&
1685 prop & SA_TTYSTOP))
1686 break; /* == ignore */
1687 p->p_xstat = sig;
1688 proc_stop(p);
1689 while (p->p_stat == SSTOP) {
1690 tstop();
1691 }
1692 break;
1693 } else if (prop & SA_IGNORE) {
1694 /*
1695 * Except for SIGCONT, shouldn't get here.
1696 * Default action is to ignore; drop it.
1697 */
1698 break; /* == ignore */
1699 } else {
1700 rel_mplock();
1701 return (sig);
1702 }
1703
1704 /*NOTREACHED*/
1705
1706 case (int)SIG_IGN:
1707 /*
1708 * Masking above should prevent us ever trying
1709 * to take action on an ignored signal other
1710 * than SIGCONT, unless process is traced.
1711 */
1712 if ((prop & SA_CONT) == 0 &&
1713 (p->p_flag & P_TRACED) == 0)
1714 kprintf("issignal\n");
1715 break; /* == ignore */
1716
1717 default:
1718 /*
1719 * This signal has an action, let
1720 * postsig() process it.
1721 */
1722 rel_mplock();
1723 return (sig);
1724 }
1725 lwp_delsig(lp, sig); /* take the signal! */
1726 }
1727 /* NOTREACHED */
1728 }
1729
1730 /*
1731 * Take the action for the specified signal
1732 * from the current set of pending signals.
1733 */
1734 void
1735 postsig(int sig)
1736 {
1737 struct lwp *lp = curthread->td_lwp;
1738 struct proc *p = lp->lwp_proc;
1739 struct sigacts *ps = p->p_sigacts;
1740 sig_t action;
1741 sigset_t returnmask;
1742 int code;
1743
1744 KASSERT(sig != 0, ("postsig"));
1745
1746 /*
1747 * If we are a virtual kernel running an emulated user process
1748 * context, switch back to the virtual kernel context before
1749 * trying to post the signal.
1750 */
1751 if (p->p_vkernel && p->p_vkernel->vk_current) {
1752 struct trapframe *tf = curthread->td_lwp->lwp_md.md_regs;
1753 tf->tf_trapno = 0;
1754 vkernel_trap(p, tf);
1755 }
1756
1757 lwp_delsig(lp, sig);
1758 action = ps->ps_sigact[_SIG_IDX(sig)];
1759 #ifdef KTRACE
1760 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
1761 ktrpsig(p, sig, action, lp->lwp_flag & LWP_OLDMASK ?
1762 &lp->lwp_oldsigmask : &lp->lwp_sigmask, 0);
1763 #endif
1764 STOPEVENT(p, S_SIG, sig);
1765
1766 if (action == SIG_DFL) {
1767 /*
1768 * Default action, where the default is to kill
1769 * the process. (Other cases were ignored above.)
1770 */
1771 sigexit(p, sig);
1772 /* NOTREACHED */
1773 } else {
1774 /*
1775 * If we get here, the signal must be caught.
1776 */
1777 KASSERT(action != SIG_IGN && !SIGISMEMBER(lp->lwp_sigmask, sig),
1778 ("postsig action"));
1779
1780 crit_enter();
1781
1782 /*
1783 * Reset the signal handler if asked to
1784 */
1785 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
1786 /*
1787 * See kern_sigaction() for origin of this code.
1788 */
1789 SIGDELSET(p->p_sigcatch, sig);
1790 if (sig != SIGCONT &&
1791 sigprop(sig) & SA_IGNORE)
1792 SIGADDSET(p->p_sigignore, sig);
1793 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1794 }
1795
1796 /*
1797 * Handle the mailbox case. Copyout to the appropriate
1798 * location but do not generate a signal frame. The system
1799 * call simply returns EINTR and the user is responsible for
1800 * polling the mailbox.
1801 */
1802 if (SIGISMEMBER(ps->ps_sigmailbox, sig)) {
1803 int sig_copy = sig;
1804 copyout(&sig_copy, (void *)action, sizeof(int));
1805 curproc->p_flag |= P_MAILBOX;
1806 crit_exit();
1807 goto done;
1808 }
1809
1810 /*
1811 * Set the signal mask and calculate the mask to restore
1812 * when the signal function returns.
1813 *
1814 * Special case: user has done a sigsuspend. Here the
1815 * current mask is not of interest, but rather the
1816 * mask from before the sigsuspend is what we want
1817 * restored after the signal processing is completed.
1818 */
1819 if (lp->lwp_flag & LWP_OLDMASK) {
1820 returnmask = lp->lwp_oldsigmask;
1821 lp->lwp_flag &= ~LWP_OLDMASK;
1822 } else {
1823 returnmask = lp->lwp_sigmask;
1824 }
1825
1826 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
1827 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1828 SIGADDSET(lp->lwp_sigmask, sig);
1829
1830 crit_exit();
1831 lp->lwp_ru.ru_nsignals++;
1832 if (lp->lwp_sig != sig) {
1833 code = 0;
1834 } else {
1835 code = lp->lwp_code;
1836 lp->lwp_code = 0;
1837 lp->lwp_sig = 0;
1838 }
1839 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
1840 }
1841 done:
1842 ;
1843 }
1844
1845 /*
1846 * Kill the current process for stated reason.
1847 */
1848 void
1849 killproc(struct proc *p, char *why)
1850 {
1851 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n",
1852 p->p_pid, p->p_comm,
1853 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
1854 ksignal(p, SIGKILL);
1855 }
1856
1857 /*
1858 * Force the current process to exit with the specified signal, dumping core
1859 * if appropriate. We bypass the normal tests for masked and caught signals,
1860 * allowing unrecoverable failures to terminate the process without changing
1861 * signal state. Mark the accounting record with the signal termination.
1862 * If dumping core, save the signal number for the debugger. Calls exit and
1863 * does not return.
1864 */
1865 void
1866 sigexit(struct proc *p, int sig)
1867 {
1868 struct lwp *lp = FIRST_LWP_IN_PROC(p); /* XXX lwp */
1869
1870 p->p_acflag |= AXSIG;
1871 if (sigprop(sig) & SA_CORE) {
1872 lp->lwp_sig = sig;
1873 /*
1874 * Log signals which would cause core dumps
1875 * (Log as LOG_INFO to appease those who don't want
1876 * these messages.)
1877 * XXX : Todo, as well as euid, write out ruid too
1878 */
1879 if (coredump(lp, sig) == 0)
1880 sig |= WCOREFLAG;
1881 if (kern_logsigexit)
1882 log(LOG_INFO,
1883 "pid %d (%s), uid %d: exited on signal %d%s\n",
1884 p->p_pid, p->p_comm,
1885 p->p_ucred ? p->p_ucred->cr_uid : -1,
1886 sig &~ WCOREFLAG,
1887 sig & WCOREFLAG ? " (core dumped)" : "");
1888 }
1889 exit1(W_EXITCODE(0, sig));
1890 /* NOTREACHED */
1891 }
1892
1893 static char corefilename[MAXPATHLEN+1] = {"%N.core"};
1894 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
1895 sizeof(corefilename), "process corefile name format string");
1896
1897 /*
1898 * expand_name(name, uid, pid)
1899 * Expand the name described in corefilename, using name, uid, and pid.
1900 * corefilename is a kprintf-like string, with three format specifiers:
1901 * %N name of process ("name")
1902 * %P process id (pid)
1903 * %U user id (uid)
1904 * For example, "%N.core" is the default; they can be disabled completely
1905 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
1906 * This is controlled by the sysctl variable kern.corefile (see above).
1907 */
1908
1909 static char *
1910 expand_name(const char *name, uid_t uid, pid_t pid)
1911 {
1912 char *temp;
1913 char buf[11]; /* Buffer for pid/uid -- max 4B */
1914 int i, n;
1915 char *format = corefilename;
1916 size_t namelen;
1917
1918 temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
1919 if (temp == NULL)
1920 return NULL;
1921 namelen = strlen(name);
1922 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
1923 int l;
1924 switch (format[i]) {
1925 case '%': /* Format character */
1926 i++;
1927 switch (format[i]) {
1928 case '%':
1929 temp[n++] = '%';
1930 break;
1931 case 'N': /* process name */
1932 if ((n + namelen) > MAXPATHLEN) {
1933 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1934 pid, name, uid, temp, name);
1935 kfree(temp, M_TEMP);
1936 return NULL;
1937 }
1938 memcpy(temp+n, name, namelen);
1939 n += namelen;
1940 break;
1941 case 'P': /* process id */
1942 l = ksprintf(buf, "%u", pid);
1943 if ((n + l) > MAXPATHLEN) {
1944 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1945 pid, name, uid, temp, name);
1946 kfree(temp, M_TEMP);
1947 return NULL;
1948 }
1949 memcpy(temp+n, buf, l);
1950 n += l;
1951 break;
1952 case 'U': /* user id */
1953 l = ksprintf(buf, "%u", uid);
1954 if ((n + l) > MAXPATHLEN) {
1955 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1956 pid, name, uid, temp, name);
1957 kfree(temp, M_TEMP);
1958 return NULL;
1959 }
1960 memcpy(temp+n, buf, l);
1961 n += l;
1962 break;
1963 default:
1964 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
1965 }
1966 break;
1967 default:
1968 temp[n++] = format[i];
1969 }
1970 }
1971 temp[n] = '\0';
1972 return temp;
1973 }
1974
1975 /*
1976 * Dump a process' core. The main routine does some
1977 * policy checking, and creates the name of the coredump;
1978 * then it passes on a vnode and a size limit to the process-specific
1979 * coredump routine if there is one; if there _is not_ one, it returns
1980 * ENOSYS; otherwise it returns the error from the process-specific routine.
1981 *
1982 * The parameter `lp' is the lwp which triggered the coredump.
1983 */
1984
1985 static int
1986 coredump(struct lwp *lp, int sig)
1987 {
1988 struct proc *p = lp->lwp_proc;
1989 struct vnode *vp;
1990 struct ucred *cred = p->p_ucred;
1991 struct flock lf;
1992 struct nlookupdata nd;
1993 struct vattr vattr;
1994 int error, error1;
1995 char *name; /* name of corefile */
1996 off_t limit;
1997
1998 STOPEVENT(p, S_CORE, 0);
1999
2000 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0)
2001 return (EFAULT);
2002
2003 /*
2004 * Note that the bulk of limit checking is done after
2005 * the corefile is created. The exception is if the limit
2006 * for corefiles is 0, in which case we don't bother
2007 * creating the corefile at all. This layout means that
2008 * a corefile is truncated instead of not being created,
2009 * if it is larger than the limit.
2010 */
2011 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
2012 if (limit == 0)
2013 return EFBIG;
2014
2015 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
2016 if (name == NULL)
2017 return (EINVAL);
2018 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
2019 if (error == 0)
2020 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
2021 kfree(name, M_TEMP);
2022 if (error) {
2023 nlookup_done(&nd);
2024 return (error);
2025 }
2026 vp = nd.nl_open_vp;
2027 nd.nl_open_vp = NULL;
2028 nlookup_done(&nd);
2029
2030 vn_unlock(vp);
2031 lf.l_whence = SEEK_SET;
2032 lf.l_start = 0;
2033 lf.l_len = 0;
2034 lf.l_type = F_WRLCK;
2035 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0);
2036 if (error)
2037 goto out2;
2038
2039 /* Don't dump to non-regular files or files with links. */
2040 if (vp->v_type != VREG ||
2041 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) {
2042 error = EFAULT;
2043 goto out1;
2044 }
2045
2046 VATTR_NULL(&vattr);
2047 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2048 vattr.va_size = 0;
2049 VOP_SETATTR(vp, &vattr, cred);
2050 p->p_acflag |= ACORE;
2051 vn_unlock(vp);
2052
2053 error = p->p_sysent->sv_coredump ?
2054 p->p_sysent->sv_coredump(lp, sig, vp, limit) : ENOSYS;
2055
2056 out1:
2057 lf.l_type = F_UNLCK;
2058 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0);
2059 out2:
2060 error1 = vn_close(vp, FWRITE);
2061 if (error == 0)
2062 error = error1;
2063 return (error);
2064 }
2065
2066 /*
2067 * Nonexistent system call-- signal process (may want to handle it).
2068 * Flag error in case process won't see signal immediately (blocked or ignored).
2069 */
2070 /* ARGSUSED */
2071 int
2072 sys_nosys(struct nosys_args *args)
2073 {
2074 lwpsignal(curproc, curthread->td_lwp, SIGSYS);
2075 return (EINVAL);
2076 }
2077
2078 /*
2079 * Send a SIGIO or SIGURG signal to a process or process group using
2080 * stored credentials rather than those of the current process.
2081 */
2082 void
2083 pgsigio(struct sigio *sigio, int sig, int checkctty)
2084 {
2085 if (sigio == NULL)
2086 return;
2087
2088 if (sigio->sio_pgid > 0) {
2089 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
2090 sigio->sio_proc))
2091 ksignal(sigio->sio_proc, sig);
2092 } else if (sigio->sio_pgid < 0) {
2093 struct proc *p;
2094
2095 lockmgr(&sigio->sio_pgrp->pg_lock, LK_EXCLUSIVE);
2096 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
2097 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
2098 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
2099 ksignal(p, sig);
2100 }
2101 lockmgr(&sigio->sio_pgrp->pg_lock, LK_RELEASE);
2102 }
2103 }
2104
2105 static int
2106 filt_sigattach(struct knote *kn)
2107 {
2108 struct proc *p = curproc;
2109
2110 kn->kn_ptr.p_proc = p;
2111 kn->kn_flags |= EV_CLEAR; /* automatically set */
2112
2113 /* XXX lock the proc here while adding to the list? */
2114 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext);
2115
2116 return (0);
2117 }
2118
2119 static void
2120 filt_sigdetach(struct knote *kn)
2121 {
2122 struct proc *p = kn->kn_ptr.p_proc;
2123
2124 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext);
2125 }
2126
2127 /*
2128 * signal knotes are shared with proc knotes, so we apply a mask to
2129 * the hint in order to differentiate them from process hints. This
2130 * could be avoided by using a signal-specific knote list, but probably
2131 * isn't worth the trouble.
2132 */
2133 static int
2134 filt_signal(struct knote *kn, long hint)
2135 {
2136 if (hint & NOTE_SIGNAL) {
2137 hint &= ~NOTE_SIGNAL;
2138
2139 if (kn->kn_id == hint)
2140 kn->kn_data++;
2141 }
2142 return (kn->kn_data != 0);
2143 }
DragonFly vkernel multiprocessor port