FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_sig.c
1 /*-
2 * Copyright (c) 1982, 1986, 1989, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94
35 */
36
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD: releng/5.4/sys/kern/kern_sig.c 145647 2005-04-28 23:42:10Z davidxu $");
39
40 #include "opt_compat.h"
41 #include "opt_ktrace.h"
42
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/signalvar.h>
46 #include <sys/vnode.h>
47 #include <sys/acct.h>
48 #include <sys/condvar.h>
49 #include <sys/event.h>
50 #include <sys/fcntl.h>
51 #include <sys/kernel.h>
52 #include <sys/kse.h>
53 #include <sys/ktr.h>
54 #include <sys/ktrace.h>
55 #include <sys/lock.h>
56 #include <sys/malloc.h>
57 #include <sys/mutex.h>
58 #include <sys/namei.h>
59 #include <sys/proc.h>
60 #include <sys/pioctl.h>
61 #include <sys/resourcevar.h>
62 #include <sys/sleepqueue.h>
63 #include <sys/smp.h>
64 #include <sys/stat.h>
65 #include <sys/sx.h>
66 #include <sys/syscallsubr.h>
67 #include <sys/sysctl.h>
68 #include <sys/sysent.h>
69 #include <sys/syslog.h>
70 #include <sys/sysproto.h>
71 #include <sys/unistd.h>
72 #include <sys/wait.h>
73
74 #include <machine/cpu.h>
75
76 #if defined (__alpha__) && !defined(COMPAT_43)
77 #error "You *really* need COMPAT_43 on the alpha for longjmp(3)"
78 #endif
79
80 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */
81
82 static int coredump(struct thread *);
83 static char *expand_name(const char *, uid_t, pid_t);
84 static int killpg1(struct thread *td, int sig, int pgid, int all);
85 static int issignal(struct thread *p);
86 static int sigprop(int sig);
87 static void tdsigwakeup(struct thread *td, int sig, sig_t action);
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 static struct thread *sigtd(struct proc *p, int sig, int prop);
92 static int kern_sigtimedwait(struct thread *td, sigset_t set,
93 siginfo_t *info, struct timespec *timeout);
94 static void do_tdsignal(struct thread *td, int sig, sigtarget_t target);
95
96 struct filterops sig_filtops =
97 { 0, filt_sigattach, filt_sigdetach, filt_signal };
98
99 static int kern_logsigexit = 1;
100 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
101 &kern_logsigexit, 0,
102 "Log processes quitting on abnormal signals to syslog(3)");
103
104 /*
105 * Policy -- Can ucred cr1 send SIGIO to process cr2?
106 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG
107 * in the right situations.
108 */
109 #define CANSIGIO(cr1, cr2) \
110 ((cr1)->cr_uid == 0 || \
111 (cr1)->cr_ruid == (cr2)->cr_ruid || \
112 (cr1)->cr_uid == (cr2)->cr_ruid || \
113 (cr1)->cr_ruid == (cr2)->cr_uid || \
114 (cr1)->cr_uid == (cr2)->cr_uid)
115
116 int sugid_coredump;
117 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
118 &sugid_coredump, 0, "Enable coredumping set user/group ID processes");
119
120 static int do_coredump = 1;
121 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
122 &do_coredump, 0, "Enable/Disable coredumps");
123
124 static int set_core_nodump_flag = 0;
125 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag,
126 0, "Enable setting the NODUMP flag on coredump files");
127
128 /*
129 * Signal properties and actions.
130 * The array below categorizes the signals and their default actions
131 * according to the following properties:
132 */
133 #define SA_KILL 0x01 /* terminates process by default */
134 #define SA_CORE 0x02 /* ditto and coredumps */
135 #define SA_STOP 0x04 /* suspend process */
136 #define SA_TTYSTOP 0x08 /* ditto, from tty */
137 #define SA_IGNORE 0x10 /* ignore by default */
138 #define SA_CONT 0x20 /* continue if suspended */
139 #define SA_CANTMASK 0x40 /* non-maskable, catchable */
140 #define SA_PROC 0x80 /* deliverable to any thread */
141
142 static int sigproptbl[NSIG] = {
143 SA_KILL|SA_PROC, /* SIGHUP */
144 SA_KILL|SA_PROC, /* SIGINT */
145 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */
146 SA_KILL|SA_CORE, /* SIGILL */
147 SA_KILL|SA_CORE, /* SIGTRAP */
148 SA_KILL|SA_CORE, /* SIGABRT */
149 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */
150 SA_KILL|SA_CORE, /* SIGFPE */
151 SA_KILL|SA_PROC, /* SIGKILL */
152 SA_KILL|SA_CORE, /* SIGBUS */
153 SA_KILL|SA_CORE, /* SIGSEGV */
154 SA_KILL|SA_CORE, /* SIGSYS */
155 SA_KILL|SA_PROC, /* SIGPIPE */
156 SA_KILL|SA_PROC, /* SIGALRM */
157 SA_KILL|SA_PROC, /* SIGTERM */
158 SA_IGNORE|SA_PROC, /* SIGURG */
159 SA_STOP|SA_PROC, /* SIGSTOP */
160 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */
161 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */
162 SA_IGNORE|SA_PROC, /* SIGCHLD */
163 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */
164 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */
165 SA_IGNORE|SA_PROC, /* SIGIO */
166 SA_KILL, /* SIGXCPU */
167 SA_KILL, /* SIGXFSZ */
168 SA_KILL|SA_PROC, /* SIGVTALRM */
169 SA_KILL|SA_PROC, /* SIGPROF */
170 SA_IGNORE|SA_PROC, /* SIGWINCH */
171 SA_IGNORE|SA_PROC, /* SIGINFO */
172 SA_KILL|SA_PROC, /* SIGUSR1 */
173 SA_KILL|SA_PROC, /* SIGUSR2 */
174 };
175
176 /*
177 * Determine signal that should be delivered to process p, the current
178 * process, 0 if none. If there is a pending stop signal with default
179 * action, the process stops in issignal().
180 * XXXKSE the check for a pending stop is not done under KSE
181 *
182 * MP SAFE.
183 */
184 int
185 cursig(struct thread *td)
186 {
187 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
188 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED);
189 mtx_assert(&sched_lock, MA_NOTOWNED);
190 return (SIGPENDING(td) ? issignal(td) : 0);
191 }
192
193 /*
194 * Arrange for ast() to handle unmasked pending signals on return to user
195 * mode. This must be called whenever a signal is added to td_siglist or
196 * unmasked in td_sigmask.
197 */
198 void
199 signotify(struct thread *td)
200 {
201 struct proc *p;
202 sigset_t set, saved;
203
204 p = td->td_proc;
205
206 PROC_LOCK_ASSERT(p, MA_OWNED);
207
208 /*
209 * If our mask changed we may have to move signal that were
210 * previously masked by all threads to our siglist.
211 */
212 set = p->p_siglist;
213 if (p->p_flag & P_SA)
214 saved = p->p_siglist;
215 SIGSETNAND(set, td->td_sigmask);
216 SIGSETNAND(p->p_siglist, set);
217 SIGSETOR(td->td_siglist, set);
218
219 if (SIGPENDING(td)) {
220 mtx_lock_spin(&sched_lock);
221 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING;
222 mtx_unlock_spin(&sched_lock);
223 }
224 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) {
225 if (!SIGSETEQ(saved, p->p_siglist)) {
226 /* pending set changed */
227 p->p_flag |= P_SIGEVENT;
228 wakeup(&p->p_siglist);
229 }
230 }
231 }
232
233 int
234 sigonstack(size_t sp)
235 {
236 struct thread *td = curthread;
237
238 return ((td->td_pflags & TDP_ALTSTACK) ?
239 #if defined(COMPAT_43)
240 ((td->td_sigstk.ss_size == 0) ?
241 (td->td_sigstk.ss_flags & SS_ONSTACK) :
242 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size))
243 #else
244 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)
245 #endif
246 : 0);
247 }
248
249 static __inline int
250 sigprop(int sig)
251 {
252
253 if (sig > 0 && sig < NSIG)
254 return (sigproptbl[_SIG_IDX(sig)]);
255 return (0);
256 }
257
258 int
259 sig_ffs(sigset_t *set)
260 {
261 int i;
262
263 for (i = 0; i < _SIG_WORDS; i++)
264 if (set->__bits[i])
265 return (ffs(set->__bits[i]) + (i * 32));
266 return (0);
267 }
268
269 /*
270 * kern_sigaction
271 * sigaction
272 * freebsd4_sigaction
273 * osigaction
274 *
275 * MPSAFE
276 */
277 int
278 kern_sigaction(td, sig, act, oact, flags)
279 struct thread *td;
280 register int sig;
281 struct sigaction *act, *oact;
282 int flags;
283 {
284 struct sigacts *ps;
285 struct thread *td0;
286 struct proc *p = td->td_proc;
287
288 if (!_SIG_VALID(sig))
289 return (EINVAL);
290
291 PROC_LOCK(p);
292 ps = p->p_sigacts;
293 mtx_lock(&ps->ps_mtx);
294 if (oact) {
295 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
296 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
297 oact->sa_flags = 0;
298 if (SIGISMEMBER(ps->ps_sigonstack, sig))
299 oact->sa_flags |= SA_ONSTACK;
300 if (!SIGISMEMBER(ps->ps_sigintr, sig))
301 oact->sa_flags |= SA_RESTART;
302 if (SIGISMEMBER(ps->ps_sigreset, sig))
303 oact->sa_flags |= SA_RESETHAND;
304 if (SIGISMEMBER(ps->ps_signodefer, sig))
305 oact->sa_flags |= SA_NODEFER;
306 if (SIGISMEMBER(ps->ps_siginfo, sig))
307 oact->sa_flags |= SA_SIGINFO;
308 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP)
309 oact->sa_flags |= SA_NOCLDSTOP;
310 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT)
311 oact->sa_flags |= SA_NOCLDWAIT;
312 }
313 if (act) {
314 if ((sig == SIGKILL || sig == SIGSTOP) &&
315 act->sa_handler != SIG_DFL) {
316 mtx_unlock(&ps->ps_mtx);
317 PROC_UNLOCK(p);
318 return (EINVAL);
319 }
320
321 /*
322 * Change setting atomically.
323 */
324
325 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
326 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
327 if (act->sa_flags & SA_SIGINFO) {
328 ps->ps_sigact[_SIG_IDX(sig)] =
329 (__sighandler_t *)act->sa_sigaction;
330 SIGADDSET(ps->ps_siginfo, sig);
331 } else {
332 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
333 SIGDELSET(ps->ps_siginfo, sig);
334 }
335 if (!(act->sa_flags & SA_RESTART))
336 SIGADDSET(ps->ps_sigintr, sig);
337 else
338 SIGDELSET(ps->ps_sigintr, sig);
339 if (act->sa_flags & SA_ONSTACK)
340 SIGADDSET(ps->ps_sigonstack, sig);
341 else
342 SIGDELSET(ps->ps_sigonstack, sig);
343 if (act->sa_flags & SA_RESETHAND)
344 SIGADDSET(ps->ps_sigreset, sig);
345 else
346 SIGDELSET(ps->ps_sigreset, sig);
347 if (act->sa_flags & SA_NODEFER)
348 SIGADDSET(ps->ps_signodefer, sig);
349 else
350 SIGDELSET(ps->ps_signodefer, sig);
351 if (sig == SIGCHLD) {
352 if (act->sa_flags & SA_NOCLDSTOP)
353 ps->ps_flag |= PS_NOCLDSTOP;
354 else
355 ps->ps_flag &= ~PS_NOCLDSTOP;
356 if (act->sa_flags & SA_NOCLDWAIT) {
357 /*
358 * Paranoia: since SA_NOCLDWAIT is implemented
359 * by reparenting the dying child to PID 1 (and
360 * trust it to reap the zombie), PID 1 itself
361 * is forbidden to set SA_NOCLDWAIT.
362 */
363 if (p->p_pid == 1)
364 ps->ps_flag &= ~PS_NOCLDWAIT;
365 else
366 ps->ps_flag |= PS_NOCLDWAIT;
367 } else
368 ps->ps_flag &= ~PS_NOCLDWAIT;
369 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
370 ps->ps_flag |= PS_CLDSIGIGN;
371 else
372 ps->ps_flag &= ~PS_CLDSIGIGN;
373 }
374 /*
375 * Set bit in ps_sigignore for signals that are set to SIG_IGN,
376 * and for signals set to SIG_DFL where the default is to
377 * ignore. However, don't put SIGCONT in ps_sigignore, as we
378 * have to restart the process.
379 */
380 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
381 (sigprop(sig) & SA_IGNORE &&
382 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
383 if ((p->p_flag & P_SA) &&
384 SIGISMEMBER(p->p_siglist, sig)) {
385 p->p_flag |= P_SIGEVENT;
386 wakeup(&p->p_siglist);
387 }
388 /* never to be seen again */
389 SIGDELSET(p->p_siglist, sig);
390 mtx_lock_spin(&sched_lock);
391 FOREACH_THREAD_IN_PROC(p, td0)
392 SIGDELSET(td0->td_siglist, sig);
393 mtx_unlock_spin(&sched_lock);
394 if (sig != SIGCONT)
395 /* easier in psignal */
396 SIGADDSET(ps->ps_sigignore, sig);
397 SIGDELSET(ps->ps_sigcatch, sig);
398 } else {
399 SIGDELSET(ps->ps_sigignore, sig);
400 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
401 SIGDELSET(ps->ps_sigcatch, sig);
402 else
403 SIGADDSET(ps->ps_sigcatch, sig);
404 }
405 #ifdef COMPAT_FREEBSD4
406 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
407 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
408 (flags & KSA_FREEBSD4) == 0)
409 SIGDELSET(ps->ps_freebsd4, sig);
410 else
411 SIGADDSET(ps->ps_freebsd4, sig);
412 #endif
413 #ifdef COMPAT_43
414 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
415 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
416 (flags & KSA_OSIGSET) == 0)
417 SIGDELSET(ps->ps_osigset, sig);
418 else
419 SIGADDSET(ps->ps_osigset, sig);
420 #endif
421 }
422 mtx_unlock(&ps->ps_mtx);
423 PROC_UNLOCK(p);
424 return (0);
425 }
426
427 #ifndef _SYS_SYSPROTO_H_
428 struct sigaction_args {
429 int sig;
430 struct sigaction *act;
431 struct sigaction *oact;
432 };
433 #endif
434 /*
435 * MPSAFE
436 */
437 int
438 sigaction(td, uap)
439 struct thread *td;
440 register struct sigaction_args *uap;
441 {
442 struct sigaction act, oact;
443 register struct sigaction *actp, *oactp;
444 int error;
445
446 actp = (uap->act != NULL) ? &act : NULL;
447 oactp = (uap->oact != NULL) ? &oact : NULL;
448 if (actp) {
449 error = copyin(uap->act, actp, sizeof(act));
450 if (error)
451 return (error);
452 }
453 error = kern_sigaction(td, uap->sig, actp, oactp, 0);
454 if (oactp && !error)
455 error = copyout(oactp, uap->oact, sizeof(oact));
456 return (error);
457 }
458
459 #ifdef COMPAT_FREEBSD4
460 #ifndef _SYS_SYSPROTO_H_
461 struct freebsd4_sigaction_args {
462 int sig;
463 struct sigaction *act;
464 struct sigaction *oact;
465 };
466 #endif
467 /*
468 * MPSAFE
469 */
470 int
471 freebsd4_sigaction(td, uap)
472 struct thread *td;
473 register struct freebsd4_sigaction_args *uap;
474 {
475 struct sigaction act, oact;
476 register struct sigaction *actp, *oactp;
477 int error;
478
479
480 actp = (uap->act != NULL) ? &act : NULL;
481 oactp = (uap->oact != NULL) ? &oact : NULL;
482 if (actp) {
483 error = copyin(uap->act, actp, sizeof(act));
484 if (error)
485 return (error);
486 }
487 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4);
488 if (oactp && !error)
489 error = copyout(oactp, uap->oact, sizeof(oact));
490 return (error);
491 }
492 #endif /* COMAPT_FREEBSD4 */
493
494 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
495 #ifndef _SYS_SYSPROTO_H_
496 struct osigaction_args {
497 int signum;
498 struct osigaction *nsa;
499 struct osigaction *osa;
500 };
501 #endif
502 /*
503 * MPSAFE
504 */
505 int
506 osigaction(td, uap)
507 struct thread *td;
508 register struct osigaction_args *uap;
509 {
510 struct osigaction sa;
511 struct sigaction nsa, osa;
512 register struct sigaction *nsap, *osap;
513 int error;
514
515 if (uap->signum <= 0 || uap->signum >= ONSIG)
516 return (EINVAL);
517
518 nsap = (uap->nsa != NULL) ? &nsa : NULL;
519 osap = (uap->osa != NULL) ? &osa : NULL;
520
521 if (nsap) {
522 error = copyin(uap->nsa, &sa, sizeof(sa));
523 if (error)
524 return (error);
525 nsap->sa_handler = sa.sa_handler;
526 nsap->sa_flags = sa.sa_flags;
527 OSIG2SIG(sa.sa_mask, nsap->sa_mask);
528 }
529 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
530 if (osap && !error) {
531 sa.sa_handler = osap->sa_handler;
532 sa.sa_flags = osap->sa_flags;
533 SIG2OSIG(osap->sa_mask, sa.sa_mask);
534 error = copyout(&sa, uap->osa, sizeof(sa));
535 }
536 return (error);
537 }
538
539 #if !defined(__i386__) && !defined(__alpha__)
540 /* Avoid replicating the same stub everywhere */
541 int
542 osigreturn(td, uap)
543 struct thread *td;
544 struct osigreturn_args *uap;
545 {
546
547 return (nosys(td, (struct nosys_args *)uap));
548 }
549 #endif
550 #endif /* COMPAT_43 */
551
552 /*
553 * Initialize signal state for process 0;
554 * set to ignore signals that are ignored by default.
555 */
556 void
557 siginit(p)
558 struct proc *p;
559 {
560 register int i;
561 struct sigacts *ps;
562
563 PROC_LOCK(p);
564 ps = p->p_sigacts;
565 mtx_lock(&ps->ps_mtx);
566 for (i = 1; i <= NSIG; i++)
567 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
568 SIGADDSET(ps->ps_sigignore, i);
569 mtx_unlock(&ps->ps_mtx);
570 PROC_UNLOCK(p);
571 }
572
573 /*
574 * Reset signals for an exec of the specified process.
575 */
576 void
577 execsigs(struct proc *p)
578 {
579 struct sigacts *ps;
580 int sig;
581 struct thread *td;
582
583 /*
584 * Reset caught signals. Held signals remain held
585 * through td_sigmask (unless they were caught,
586 * and are now ignored by default).
587 */
588 PROC_LOCK_ASSERT(p, MA_OWNED);
589 td = FIRST_THREAD_IN_PROC(p);
590 ps = p->p_sigacts;
591 mtx_lock(&ps->ps_mtx);
592 while (SIGNOTEMPTY(ps->ps_sigcatch)) {
593 sig = sig_ffs(&ps->ps_sigcatch);
594 SIGDELSET(ps->ps_sigcatch, sig);
595 if (sigprop(sig) & SA_IGNORE) {
596 if (sig != SIGCONT)
597 SIGADDSET(ps->ps_sigignore, sig);
598 SIGDELSET(p->p_siglist, sig);
599 /*
600 * There is only one thread at this point.
601 */
602 SIGDELSET(td->td_siglist, sig);
603 }
604 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
605 }
606 /*
607 * Reset stack state to the user stack.
608 * Clear set of signals caught on the signal stack.
609 */
610 td->td_sigstk.ss_flags = SS_DISABLE;
611 td->td_sigstk.ss_size = 0;
612 td->td_sigstk.ss_sp = 0;
613 td->td_pflags &= ~TDP_ALTSTACK;
614 /*
615 * Reset no zombies if child dies flag as Solaris does.
616 */
617 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN);
618 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
619 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL;
620 mtx_unlock(&ps->ps_mtx);
621 }
622
623 /*
624 * kern_sigprocmask()
625 *
626 * Manipulate signal mask.
627 */
628 int
629 kern_sigprocmask(td, how, set, oset, old)
630 struct thread *td;
631 int how;
632 sigset_t *set, *oset;
633 int old;
634 {
635 int error;
636
637 PROC_LOCK(td->td_proc);
638 if (oset != NULL)
639 *oset = td->td_sigmask;
640
641 error = 0;
642 if (set != NULL) {
643 switch (how) {
644 case SIG_BLOCK:
645 SIG_CANTMASK(*set);
646 SIGSETOR(td->td_sigmask, *set);
647 break;
648 case SIG_UNBLOCK:
649 SIGSETNAND(td->td_sigmask, *set);
650 signotify(td);
651 break;
652 case SIG_SETMASK:
653 SIG_CANTMASK(*set);
654 if (old)
655 SIGSETLO(td->td_sigmask, *set);
656 else
657 td->td_sigmask = *set;
658 signotify(td);
659 break;
660 default:
661 error = EINVAL;
662 break;
663 }
664 }
665 PROC_UNLOCK(td->td_proc);
666 return (error);
667 }
668
669 /*
670 * sigprocmask() - MP SAFE
671 */
672
673 #ifndef _SYS_SYSPROTO_H_
674 struct sigprocmask_args {
675 int how;
676 const sigset_t *set;
677 sigset_t *oset;
678 };
679 #endif
680 int
681 sigprocmask(td, uap)
682 register struct thread *td;
683 struct sigprocmask_args *uap;
684 {
685 sigset_t set, oset;
686 sigset_t *setp, *osetp;
687 int error;
688
689 setp = (uap->set != NULL) ? &set : NULL;
690 osetp = (uap->oset != NULL) ? &oset : NULL;
691 if (setp) {
692 error = copyin(uap->set, setp, sizeof(set));
693 if (error)
694 return (error);
695 }
696 error = kern_sigprocmask(td, uap->how, setp, osetp, 0);
697 if (osetp && !error) {
698 error = copyout(osetp, uap->oset, sizeof(oset));
699 }
700 return (error);
701 }
702
703 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
704 /*
705 * osigprocmask() - MP SAFE
706 */
707 #ifndef _SYS_SYSPROTO_H_
708 struct osigprocmask_args {
709 int how;
710 osigset_t mask;
711 };
712 #endif
713 int
714 osigprocmask(td, uap)
715 register struct thread *td;
716 struct osigprocmask_args *uap;
717 {
718 sigset_t set, oset;
719 int error;
720
721 OSIG2SIG(uap->mask, set);
722 error = kern_sigprocmask(td, uap->how, &set, &oset, 1);
723 SIG2OSIG(oset, td->td_retval[0]);
724 return (error);
725 }
726 #endif /* COMPAT_43 */
727
728 #ifndef _SYS_SYSPROTO_H_
729 struct sigpending_args {
730 sigset_t *set;
731 };
732 #endif
733 /*
734 * MPSAFE
735 */
736 int
737 sigwait(struct thread *td, struct sigwait_args *uap)
738 {
739 siginfo_t info;
740 sigset_t set;
741 int error;
742
743 error = copyin(uap->set, &set, sizeof(set));
744 if (error) {
745 td->td_retval[0] = error;
746 return (0);
747 }
748
749 error = kern_sigtimedwait(td, set, &info, NULL);
750 if (error) {
751 if (error == ERESTART)
752 return (error);
753 td->td_retval[0] = error;
754 return (0);
755 }
756
757 error = copyout(&info.si_signo, uap->sig, sizeof(info.si_signo));
758 /* Repost if we got an error. */
759 if (error && info.si_signo) {
760 PROC_LOCK(td->td_proc);
761 tdsignal(td, info.si_signo, SIGTARGET_TD);
762 PROC_UNLOCK(td->td_proc);
763 }
764 td->td_retval[0] = error;
765 return (0);
766 }
767 /*
768 * MPSAFE
769 */
770 int
771 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap)
772 {
773 struct timespec ts;
774 struct timespec *timeout;
775 sigset_t set;
776 siginfo_t info;
777 int error;
778
779 if (uap->timeout) {
780 error = copyin(uap->timeout, &ts, sizeof(ts));
781 if (error)
782 return (error);
783
784 timeout = &ts;
785 } else
786 timeout = NULL;
787
788 error = copyin(uap->set, &set, sizeof(set));
789 if (error)
790 return (error);
791
792 error = kern_sigtimedwait(td, set, &info, timeout);
793 if (error)
794 return (error);
795
796 if (uap->info)
797 error = copyout(&info, uap->info, sizeof(info));
798 /* Repost if we got an error. */
799 if (error && info.si_signo) {
800 PROC_LOCK(td->td_proc);
801 tdsignal(td, info.si_signo, SIGTARGET_TD);
802 PROC_UNLOCK(td->td_proc);
803 } else {
804 td->td_retval[0] = info.si_signo;
805 }
806 return (error);
807 }
808
809 /*
810 * MPSAFE
811 */
812 int
813 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap)
814 {
815 siginfo_t info;
816 sigset_t set;
817 int error;
818
819 error = copyin(uap->set, &set, sizeof(set));
820 if (error)
821 return (error);
822
823 error = kern_sigtimedwait(td, set, &info, NULL);
824 if (error)
825 return (error);
826
827 if (uap->info)
828 error = copyout(&info, uap->info, sizeof(info));
829 /* Repost if we got an error. */
830 if (error && info.si_signo) {
831 PROC_LOCK(td->td_proc);
832 tdsignal(td, info.si_signo, SIGTARGET_TD);
833 PROC_UNLOCK(td->td_proc);
834 } else {
835 td->td_retval[0] = info.si_signo;
836 }
837 return (error);
838 }
839
840 static int
841 kern_sigtimedwait(struct thread *td, sigset_t waitset, siginfo_t *info,
842 struct timespec *timeout)
843 {
844 struct sigacts *ps;
845 sigset_t savedmask;
846 struct proc *p;
847 int error, sig, hz, i, timevalid = 0;
848 struct timespec rts, ets, ts;
849 struct timeval tv;
850
851 p = td->td_proc;
852 error = 0;
853 sig = 0;
854 SIG_CANTMASK(waitset);
855
856 PROC_LOCK(p);
857 ps = p->p_sigacts;
858 savedmask = td->td_sigmask;
859 if (timeout) {
860 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) {
861 timevalid = 1;
862 getnanouptime(&rts);
863 ets = rts;
864 timespecadd(&ets, timeout);
865 }
866 }
867
868 again:
869 for (i = 1; i <= _SIG_MAXSIG; ++i) {
870 if (!SIGISMEMBER(waitset, i))
871 continue;
872 if (SIGISMEMBER(td->td_siglist, i)) {
873 SIGFILLSET(td->td_sigmask);
874 SIG_CANTMASK(td->td_sigmask);
875 SIGDELSET(td->td_sigmask, i);
876 mtx_lock(&ps->ps_mtx);
877 sig = cursig(td);
878 i = 0;
879 mtx_unlock(&ps->ps_mtx);
880 } else if (SIGISMEMBER(p->p_siglist, i)) {
881 if (p->p_flag & P_SA) {
882 p->p_flag |= P_SIGEVENT;
883 wakeup(&p->p_siglist);
884 }
885 SIGDELSET(p->p_siglist, i);
886 SIGADDSET(td->td_siglist, i);
887 SIGFILLSET(td->td_sigmask);
888 SIG_CANTMASK(td->td_sigmask);
889 SIGDELSET(td->td_sigmask, i);
890 mtx_lock(&ps->ps_mtx);
891 sig = cursig(td);
892 i = 0;
893 mtx_unlock(&ps->ps_mtx);
894 }
895 if (sig)
896 goto out;
897 }
898 if (error)
899 goto out;
900
901 /*
902 * POSIX says this must be checked after looking for pending
903 * signals.
904 */
905 if (timeout) {
906 if (!timevalid) {
907 error = EINVAL;
908 goto out;
909 }
910 getnanouptime(&rts);
911 if (timespeccmp(&rts, &ets, >=)) {
912 error = EAGAIN;
913 goto out;
914 }
915 ts = ets;
916 timespecsub(&ts, &rts);
917 TIMESPEC_TO_TIMEVAL(&tv, &ts);
918 hz = tvtohz(&tv);
919 } else
920 hz = 0;
921
922 td->td_sigmask = savedmask;
923 SIGSETNAND(td->td_sigmask, waitset);
924 signotify(td);
925 error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz);
926 if (timeout) {
927 if (error == ERESTART) {
928 /* timeout can not be restarted. */
929 error = EINTR;
930 } else if (error == EAGAIN) {
931 /* will calculate timeout by ourself. */
932 error = 0;
933 }
934 }
935 goto again;
936
937 out:
938 td->td_sigmask = savedmask;
939 signotify(td);
940 if (sig) {
941 sig_t action;
942
943 error = 0;
944 mtx_lock(&ps->ps_mtx);
945 action = ps->ps_sigact[_SIG_IDX(sig)];
946 mtx_unlock(&ps->ps_mtx);
947 #ifdef KTRACE
948 if (KTRPOINT(td, KTR_PSIG))
949 ktrpsig(sig, action, &td->td_sigmask, 0);
950 #endif
951 _STOPEVENT(p, S_SIG, sig);
952
953 SIGDELSET(td->td_siglist, sig);
954 bzero(info, sizeof(*info));
955 info->si_signo = sig;
956 info->si_code = 0;
957 }
958 PROC_UNLOCK(p);
959 return (error);
960 }
961
962 /*
963 * MPSAFE
964 */
965 int
966 sigpending(td, uap)
967 struct thread *td;
968 struct sigpending_args *uap;
969 {
970 struct proc *p = td->td_proc;
971 sigset_t siglist;
972
973 PROC_LOCK(p);
974 siglist = p->p_siglist;
975 SIGSETOR(siglist, td->td_siglist);
976 PROC_UNLOCK(p);
977 return (copyout(&siglist, uap->set, sizeof(sigset_t)));
978 }
979
980 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
981 #ifndef _SYS_SYSPROTO_H_
982 struct osigpending_args {
983 int dummy;
984 };
985 #endif
986 /*
987 * MPSAFE
988 */
989 int
990 osigpending(td, uap)
991 struct thread *td;
992 struct osigpending_args *uap;
993 {
994 struct proc *p = td->td_proc;
995 sigset_t siglist;
996
997 PROC_LOCK(p);
998 siglist = p->p_siglist;
999 SIGSETOR(siglist, td->td_siglist);
1000 PROC_UNLOCK(p);
1001 SIG2OSIG(siglist, td->td_retval[0]);
1002 return (0);
1003 }
1004 #endif /* COMPAT_43 */
1005
1006 #if defined(COMPAT_43)
1007 /*
1008 * Generalized interface signal handler, 4.3-compatible.
1009 */
1010 #ifndef _SYS_SYSPROTO_H_
1011 struct osigvec_args {
1012 int signum;
1013 struct sigvec *nsv;
1014 struct sigvec *osv;
1015 };
1016 #endif
1017 /*
1018 * MPSAFE
1019 */
1020 /* ARGSUSED */
1021 int
1022 osigvec(td, uap)
1023 struct thread *td;
1024 register struct osigvec_args *uap;
1025 {
1026 struct sigvec vec;
1027 struct sigaction nsa, osa;
1028 register struct sigaction *nsap, *osap;
1029 int error;
1030
1031 if (uap->signum <= 0 || uap->signum >= ONSIG)
1032 return (EINVAL);
1033 nsap = (uap->nsv != NULL) ? &nsa : NULL;
1034 osap = (uap->osv != NULL) ? &osa : NULL;
1035 if (nsap) {
1036 error = copyin(uap->nsv, &vec, sizeof(vec));
1037 if (error)
1038 return (error);
1039 nsap->sa_handler = vec.sv_handler;
1040 OSIG2SIG(vec.sv_mask, nsap->sa_mask);
1041 nsap->sa_flags = vec.sv_flags;
1042 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */
1043 }
1044 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
1045 if (osap && !error) {
1046 vec.sv_handler = osap->sa_handler;
1047 SIG2OSIG(osap->sa_mask, vec.sv_mask);
1048 vec.sv_flags = osap->sa_flags;
1049 vec.sv_flags &= ~SA_NOCLDWAIT;
1050 vec.sv_flags ^= SA_RESTART;
1051 error = copyout(&vec, uap->osv, sizeof(vec));
1052 }
1053 return (error);
1054 }
1055
1056 #ifndef _SYS_SYSPROTO_H_
1057 struct osigblock_args {
1058 int mask;
1059 };
1060 #endif
1061 /*
1062 * MPSAFE
1063 */
1064 int
1065 osigblock(td, uap)
1066 register struct thread *td;
1067 struct osigblock_args *uap;
1068 {
1069 struct proc *p = td->td_proc;
1070 sigset_t set;
1071
1072 OSIG2SIG(uap->mask, set);
1073 SIG_CANTMASK(set);
1074 PROC_LOCK(p);
1075 SIG2OSIG(td->td_sigmask, td->td_retval[0]);
1076 SIGSETOR(td->td_sigmask, set);
1077 PROC_UNLOCK(p);
1078 return (0);
1079 }
1080
1081 #ifndef _SYS_SYSPROTO_H_
1082 struct osigsetmask_args {
1083 int mask;
1084 };
1085 #endif
1086 /*
1087 * MPSAFE
1088 */
1089 int
1090 osigsetmask(td, uap)
1091 struct thread *td;
1092 struct osigsetmask_args *uap;
1093 {
1094 struct proc *p = td->td_proc;
1095 sigset_t set;
1096
1097 OSIG2SIG(uap->mask, set);
1098 SIG_CANTMASK(set);
1099 PROC_LOCK(p);
1100 SIG2OSIG(td->td_sigmask, td->td_retval[0]);
1101 SIGSETLO(td->td_sigmask, set);
1102 signotify(td);
1103 PROC_UNLOCK(p);
1104 return (0);
1105 }
1106 #endif /* COMPAT_43 */
1107
1108 /*
1109 * Suspend process until signal, providing mask to be set
1110 * in the meantime.
1111 ***** XXXKSE this doesn't make sense under KSE.
1112 ***** Do we suspend the thread or all threads in the process?
1113 ***** How do we suspend threads running NOW on another processor?
1114 */
1115 #ifndef _SYS_SYSPROTO_H_
1116 struct sigsuspend_args {
1117 const sigset_t *sigmask;
1118 };
1119 #endif
1120 /*
1121 * MPSAFE
1122 */
1123 /* ARGSUSED */
1124 int
1125 sigsuspend(td, uap)
1126 struct thread *td;
1127 struct sigsuspend_args *uap;
1128 {
1129 sigset_t mask;
1130 int error;
1131
1132 error = copyin(uap->sigmask, &mask, sizeof(mask));
1133 if (error)
1134 return (error);
1135 return (kern_sigsuspend(td, mask));
1136 }
1137
1138 int
1139 kern_sigsuspend(struct thread *td, sigset_t mask)
1140 {
1141 struct proc *p = td->td_proc;
1142
1143 /*
1144 * When returning from sigsuspend, we want
1145 * the old mask to be restored after the
1146 * signal handler has finished. Thus, we
1147 * save it here and mark the sigacts structure
1148 * to indicate this.
1149 */
1150 PROC_LOCK(p);
1151 td->td_oldsigmask = td->td_sigmask;
1152 td->td_pflags |= TDP_OLDMASK;
1153 SIG_CANTMASK(mask);
1154 td->td_sigmask = mask;
1155 signotify(td);
1156 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0)
1157 /* void */;
1158 PROC_UNLOCK(p);
1159 /* always return EINTR rather than ERESTART... */
1160 return (EINTR);
1161 }
1162
1163 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1164 /*
1165 * Compatibility sigsuspend call for old binaries. Note nonstandard calling
1166 * convention: libc stub passes mask, not pointer, to save a copyin.
1167 */
1168 #ifndef _SYS_SYSPROTO_H_
1169 struct osigsuspend_args {
1170 osigset_t mask;
1171 };
1172 #endif
1173 /*
1174 * MPSAFE
1175 */
1176 /* ARGSUSED */
1177 int
1178 osigsuspend(td, uap)
1179 struct thread *td;
1180 struct osigsuspend_args *uap;
1181 {
1182 struct proc *p = td->td_proc;
1183 sigset_t mask;
1184
1185 PROC_LOCK(p);
1186 td->td_oldsigmask = td->td_sigmask;
1187 td->td_pflags |= TDP_OLDMASK;
1188 OSIG2SIG(uap->mask, mask);
1189 SIG_CANTMASK(mask);
1190 SIGSETLO(td->td_sigmask, mask);
1191 signotify(td);
1192 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0)
1193 /* void */;
1194 PROC_UNLOCK(p);
1195 /* always return EINTR rather than ERESTART... */
1196 return (EINTR);
1197 }
1198 #endif /* COMPAT_43 */
1199
1200 #if defined(COMPAT_43)
1201 #ifndef _SYS_SYSPROTO_H_
1202 struct osigstack_args {
1203 struct sigstack *nss;
1204 struct sigstack *oss;
1205 };
1206 #endif
1207 /*
1208 * MPSAFE
1209 */
1210 /* ARGSUSED */
1211 int
1212 osigstack(td, uap)
1213 struct thread *td;
1214 register struct osigstack_args *uap;
1215 {
1216 struct sigstack nss, oss;
1217 int error = 0;
1218
1219 if (uap->nss != NULL) {
1220 error = copyin(uap->nss, &nss, sizeof(nss));
1221 if (error)
1222 return (error);
1223 }
1224 oss.ss_sp = td->td_sigstk.ss_sp;
1225 oss.ss_onstack = sigonstack(cpu_getstack(td));
1226 if (uap->nss != NULL) {
1227 td->td_sigstk.ss_sp = nss.ss_sp;
1228 td->td_sigstk.ss_size = 0;
1229 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK;
1230 td->td_pflags |= TDP_ALTSTACK;
1231 }
1232 if (uap->oss != NULL)
1233 error = copyout(&oss, uap->oss, sizeof(oss));
1234
1235 return (error);
1236 }
1237 #endif /* COMPAT_43 */
1238
1239 #ifndef _SYS_SYSPROTO_H_
1240 struct sigaltstack_args {
1241 stack_t *ss;
1242 stack_t *oss;
1243 };
1244 #endif
1245 /*
1246 * MPSAFE
1247 */
1248 /* ARGSUSED */
1249 int
1250 sigaltstack(td, uap)
1251 struct thread *td;
1252 register struct sigaltstack_args *uap;
1253 {
1254 stack_t ss, oss;
1255 int error;
1256
1257 if (uap->ss != NULL) {
1258 error = copyin(uap->ss, &ss, sizeof(ss));
1259 if (error)
1260 return (error);
1261 }
1262 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL,
1263 (uap->oss != NULL) ? &oss : NULL);
1264 if (error)
1265 return (error);
1266 if (uap->oss != NULL)
1267 error = copyout(&oss, uap->oss, sizeof(stack_t));
1268 return (error);
1269 }
1270
1271 int
1272 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss)
1273 {
1274 struct proc *p = td->td_proc;
1275 int oonstack;
1276
1277 oonstack = sigonstack(cpu_getstack(td));
1278
1279 if (oss != NULL) {
1280 *oss = td->td_sigstk;
1281 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK)
1282 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
1283 }
1284
1285 if (ss != NULL) {
1286 if (oonstack)
1287 return (EPERM);
1288 if ((ss->ss_flags & ~SS_DISABLE) != 0)
1289 return (EINVAL);
1290 if (!(ss->ss_flags & SS_DISABLE)) {
1291 if (ss->ss_size < p->p_sysent->sv_minsigstksz) {
1292 return (ENOMEM);
1293 }
1294 td->td_sigstk = *ss;
1295 td->td_pflags |= TDP_ALTSTACK;
1296 } else {
1297 td->td_pflags &= ~TDP_ALTSTACK;
1298 }
1299 }
1300 return (0);
1301 }
1302
1303 /*
1304 * Common code for kill process group/broadcast kill.
1305 * cp is calling process.
1306 */
1307 static int
1308 killpg1(td, sig, pgid, all)
1309 register struct thread *td;
1310 int sig, pgid, all;
1311 {
1312 register struct proc *p;
1313 struct pgrp *pgrp;
1314 int nfound = 0;
1315
1316 if (all) {
1317 /*
1318 * broadcast
1319 */
1320 sx_slock(&allproc_lock);
1321 LIST_FOREACH(p, &allproc, p_list) {
1322 PROC_LOCK(p);
1323 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
1324 p == td->td_proc) {
1325 PROC_UNLOCK(p);
1326 continue;
1327 }
1328 if (p_cansignal(td, p, sig) == 0) {
1329 nfound++;
1330 if (sig)
1331 psignal(p, sig);
1332 }
1333 PROC_UNLOCK(p);
1334 }
1335 sx_sunlock(&allproc_lock);
1336 } else {
1337 sx_slock(&proctree_lock);
1338 if (pgid == 0) {
1339 /*
1340 * zero pgid means send to my process group.
1341 */
1342 pgrp = td->td_proc->p_pgrp;
1343 PGRP_LOCK(pgrp);
1344 } else {
1345 pgrp = pgfind(pgid);
1346 if (pgrp == NULL) {
1347 sx_sunlock(&proctree_lock);
1348 return (ESRCH);
1349 }
1350 }
1351 sx_sunlock(&proctree_lock);
1352 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
1353 PROC_LOCK(p);
1354 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM) {
1355 PROC_UNLOCK(p);
1356 continue;
1357 }
1358 if (p_cansignal(td, p, sig) == 0) {
1359 nfound++;
1360 if (sig)
1361 psignal(p, sig);
1362 }
1363 PROC_UNLOCK(p);
1364 }
1365 PGRP_UNLOCK(pgrp);
1366 }
1367 return (nfound ? 0 : ESRCH);
1368 }
1369
1370 #ifndef _SYS_SYSPROTO_H_
1371 struct kill_args {
1372 int pid;
1373 int signum;
1374 };
1375 #endif
1376 /*
1377 * MPSAFE
1378 */
1379 /* ARGSUSED */
1380 int
1381 kill(td, uap)
1382 register struct thread *td;
1383 register struct kill_args *uap;
1384 {
1385 register struct proc *p;
1386 int error;
1387
1388 if ((u_int)uap->signum > _SIG_MAXSIG)
1389 return (EINVAL);
1390
1391 if (uap->pid > 0) {
1392 /* kill single process */
1393 if ((p = pfind(uap->pid)) == NULL) {
1394 if ((p = zpfind(uap->pid)) == NULL)
1395 return (ESRCH);
1396 }
1397 error = p_cansignal(td, p, uap->signum);
1398 if (error == 0 && uap->signum)
1399 psignal(p, uap->signum);
1400 PROC_UNLOCK(p);
1401 return (error);
1402 }
1403 switch (uap->pid) {
1404 case -1: /* broadcast signal */
1405 return (killpg1(td, uap->signum, 0, 1));
1406 case 0: /* signal own process group */
1407 return (killpg1(td, uap->signum, 0, 0));
1408 default: /* negative explicit process group */
1409 return (killpg1(td, uap->signum, -uap->pid, 0));
1410 }
1411 /* NOTREACHED */
1412 }
1413
1414 #if defined(COMPAT_43)
1415 #ifndef _SYS_SYSPROTO_H_
1416 struct okillpg_args {
1417 int pgid;
1418 int signum;
1419 };
1420 #endif
1421 /*
1422 * MPSAFE
1423 */
1424 /* ARGSUSED */
1425 int
1426 okillpg(td, uap)
1427 struct thread *td;
1428 register struct okillpg_args *uap;
1429 {
1430
1431 if ((u_int)uap->signum > _SIG_MAXSIG)
1432 return (EINVAL);
1433 return (killpg1(td, uap->signum, uap->pgid, 0));
1434 }
1435 #endif /* COMPAT_43 */
1436
1437 /*
1438 * Send a signal to a process group.
1439 */
1440 void
1441 gsignal(pgid, sig)
1442 int pgid, sig;
1443 {
1444 struct pgrp *pgrp;
1445
1446 if (pgid != 0) {
1447 sx_slock(&proctree_lock);
1448 pgrp = pgfind(pgid);
1449 sx_sunlock(&proctree_lock);
1450 if (pgrp != NULL) {
1451 pgsignal(pgrp, sig, 0);
1452 PGRP_UNLOCK(pgrp);
1453 }
1454 }
1455 }
1456
1457 /*
1458 * Send a signal to a process group. If checktty is 1,
1459 * limit to members which have a controlling terminal.
1460 */
1461 void
1462 pgsignal(pgrp, sig, checkctty)
1463 struct pgrp *pgrp;
1464 int sig, checkctty;
1465 {
1466 register struct proc *p;
1467
1468 if (pgrp) {
1469 PGRP_LOCK_ASSERT(pgrp, MA_OWNED);
1470 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
1471 PROC_LOCK(p);
1472 if (checkctty == 0 || p->p_flag & P_CONTROLT)
1473 psignal(p, sig);
1474 PROC_UNLOCK(p);
1475 }
1476 }
1477 }
1478
1479 /*
1480 * Send a signal caused by a trap to the current thread.
1481 * If it will be caught immediately, deliver it with correct code.
1482 * Otherwise, post it normally.
1483 *
1484 * MPSAFE
1485 */
1486 void
1487 trapsignal(struct thread *td, int sig, u_long code)
1488 {
1489 struct sigacts *ps;
1490 struct proc *p;
1491 siginfo_t siginfo;
1492 int error;
1493
1494 p = td->td_proc;
1495 if (td->td_pflags & TDP_SA) {
1496 if (td->td_mailbox == NULL)
1497 thread_user_enter(td);
1498 PROC_LOCK(p);
1499 SIGDELSET(td->td_sigmask, sig);
1500 mtx_lock_spin(&sched_lock);
1501 /*
1502 * Force scheduling an upcall, so UTS has chance to
1503 * process the signal before thread runs again in
1504 * userland.
1505 */
1506 if (td->td_upcall)
1507 td->td_upcall->ku_flags |= KUF_DOUPCALL;
1508 mtx_unlock_spin(&sched_lock);
1509 } else {
1510 PROC_LOCK(p);
1511 }
1512 ps = p->p_sigacts;
1513 mtx_lock(&ps->ps_mtx);
1514 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) &&
1515 !SIGISMEMBER(td->td_sigmask, sig)) {
1516 p->p_stats->p_ru.ru_nsignals++;
1517 #ifdef KTRACE
1518 if (KTRPOINT(curthread, KTR_PSIG))
1519 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)],
1520 &td->td_sigmask, code);
1521 #endif
1522 if (!(td->td_pflags & TDP_SA))
1523 (*p->p_sysent->sv_sendsig)(
1524 ps->ps_sigact[_SIG_IDX(sig)], sig,
1525 &td->td_sigmask, code);
1526 else if (td->td_mailbox == NULL) {
1527 mtx_unlock(&ps->ps_mtx);
1528 /* UTS caused a sync signal */
1529 p->p_code = code; /* XXX for core dump/debugger */
1530 p->p_sig = sig; /* XXX to verify code */
1531 sigexit(td, sig);
1532 } else {
1533 cpu_thread_siginfo(sig, code, &siginfo);
1534 mtx_unlock(&ps->ps_mtx);
1535 SIGADDSET(td->td_sigmask, sig);
1536 PROC_UNLOCK(p);
1537 error = copyout(&siginfo, &td->td_mailbox->tm_syncsig,
1538 sizeof(siginfo));
1539 PROC_LOCK(p);
1540 /* UTS memory corrupted */
1541 if (error)
1542 sigexit(td, SIGSEGV);
1543 mtx_lock(&ps->ps_mtx);
1544 }
1545 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
1546 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1547 SIGADDSET(td->td_sigmask, sig);
1548 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
1549 /*
1550 * See kern_sigaction() for origin of this code.
1551 */
1552 SIGDELSET(ps->ps_sigcatch, sig);
1553 if (sig != SIGCONT &&
1554 sigprop(sig) & SA_IGNORE)
1555 SIGADDSET(ps->ps_sigignore, sig);
1556 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1557 }
1558 mtx_unlock(&ps->ps_mtx);
1559 } else {
1560 mtx_unlock(&ps->ps_mtx);
1561 p->p_code = code; /* XXX for core dump/debugger */
1562 p->p_sig = sig; /* XXX to verify code */
1563 tdsignal(td, sig, SIGTARGET_TD);
1564 }
1565 PROC_UNLOCK(p);
1566 }
1567
1568 static struct thread *
1569 sigtd(struct proc *p, int sig, int prop)
1570 {
1571 struct thread *td, *signal_td;
1572
1573 PROC_LOCK_ASSERT(p, MA_OWNED);
1574
1575 /*
1576 * Check if current thread can handle the signal without
1577 * switching conetxt to another thread.
1578 */
1579 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig))
1580 return (curthread);
1581 signal_td = NULL;
1582 mtx_lock_spin(&sched_lock);
1583 FOREACH_THREAD_IN_PROC(p, td) {
1584 if (!SIGISMEMBER(td->td_sigmask, sig)) {
1585 signal_td = td;
1586 break;
1587 }
1588 }
1589 if (signal_td == NULL)
1590 signal_td = FIRST_THREAD_IN_PROC(p);
1591 mtx_unlock_spin(&sched_lock);
1592 return (signal_td);
1593 }
1594
1595 /*
1596 * Send the signal to the process. If the signal has an action, the action
1597 * is usually performed by the target process rather than the caller; we add
1598 * the signal to the set of pending signals for the process.
1599 *
1600 * Exceptions:
1601 * o When a stop signal is sent to a sleeping process that takes the
1602 * default action, the process is stopped without awakening it.
1603 * o SIGCONT restarts stopped processes (or puts them back to sleep)
1604 * regardless of the signal action (eg, blocked or ignored).
1605 *
1606 * Other ignored signals are discarded immediately.
1607 *
1608 * MPSAFE
1609 */
1610 void
1611 psignal(struct proc *p, int sig)
1612 {
1613 struct thread *td;
1614 int prop;
1615
1616 if (!_SIG_VALID(sig))
1617 panic("psignal(): invalid signal");
1618
1619 PROC_LOCK_ASSERT(p, MA_OWNED);
1620 /*
1621 * IEEE Std 1003.1-2001: return success when killing a zombie.
1622 */
1623 if (p->p_state == PRS_ZOMBIE)
1624 return;
1625 prop = sigprop(sig);
1626
1627 /*
1628 * Find a thread to deliver the signal to.
1629 */
1630 td = sigtd(p, sig, prop);
1631
1632 tdsignal(td, sig, SIGTARGET_P);
1633 }
1634
1635 /*
1636 * MPSAFE
1637 */
1638 void
1639 tdsignal(struct thread *td, int sig, sigtarget_t target)
1640 {
1641 sigset_t saved;
1642 struct proc *p = td->td_proc;
1643
1644 if (p->p_flag & P_SA)
1645 saved = p->p_siglist;
1646 do_tdsignal(td, sig, target);
1647 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) {
1648 if (!SIGSETEQ(saved, p->p_siglist)) {
1649 /* pending set changed */
1650 p->p_flag |= P_SIGEVENT;
1651 wakeup(&p->p_siglist);
1652 }
1653 }
1654 }
1655
1656 static void
1657 do_tdsignal(struct thread *td, int sig, sigtarget_t target)
1658 {
1659 struct proc *p;
1660 register sig_t action;
1661 sigset_t *siglist;
1662 struct thread *td0;
1663 register int prop;
1664 struct sigacts *ps;
1665
1666 if (!_SIG_VALID(sig))
1667 panic("do_tdsignal(): invalid signal");
1668
1669 p = td->td_proc;
1670 ps = p->p_sigacts;
1671
1672 PROC_LOCK_ASSERT(p, MA_OWNED);
1673 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig);
1674
1675 prop = sigprop(sig);
1676
1677 /*
1678 * If the signal is blocked and not destined for this thread, then
1679 * assign it to the process so that we can find it later in the first
1680 * thread that unblocks it. Otherwise, assign it to this thread now.
1681 */
1682 if (target == SIGTARGET_TD) {
1683 siglist = &td->td_siglist;
1684 } else {
1685 if (!SIGISMEMBER(td->td_sigmask, sig))
1686 siglist = &td->td_siglist;
1687 else
1688 siglist = &p->p_siglist;
1689 }
1690
1691 /*
1692 * If proc is traced, always give parent a chance;
1693 * if signal event is tracked by procfs, give *that*
1694 * a chance, as well.
1695 */
1696 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) {
1697 action = SIG_DFL;
1698 } else {
1699 /*
1700 * If the signal is being ignored,
1701 * then we forget about it immediately.
1702 * (Note: we don't set SIGCONT in ps_sigignore,
1703 * and if it is set to SIG_IGN,
1704 * action will be SIG_DFL here.)
1705 */
1706 mtx_lock(&ps->ps_mtx);
1707 if (SIGISMEMBER(ps->ps_sigignore, sig) ||
1708 (p->p_flag & P_WEXIT)) {
1709 mtx_unlock(&ps->ps_mtx);
1710 return;
1711 }
1712 if (SIGISMEMBER(td->td_sigmask, sig))
1713 action = SIG_HOLD;
1714 else if (SIGISMEMBER(ps->ps_sigcatch, sig))
1715 action = SIG_CATCH;
1716 else
1717 action = SIG_DFL;
1718 mtx_unlock(&ps->ps_mtx);
1719 }
1720
1721 if (prop & SA_CONT) {
1722 SIG_STOPSIGMASK(p->p_siglist);
1723 /*
1724 * XXX Should investigate leaving STOP and CONT sigs only in
1725 * the proc's siglist.
1726 */
1727 mtx_lock_spin(&sched_lock);
1728 FOREACH_THREAD_IN_PROC(p, td0)
1729 SIG_STOPSIGMASK(td0->td_siglist);
1730 mtx_unlock_spin(&sched_lock);
1731 }
1732
1733 if (prop & SA_STOP) {
1734 /*
1735 * If sending a tty stop signal to a member of an orphaned
1736 * process group, discard the signal here if the action
1737 * is default; don't stop the process below if sleeping,
1738 * and don't clear any pending SIGCONT.
1739 */
1740 if ((prop & SA_TTYSTOP) &&
1741 (p->p_pgrp->pg_jobc == 0) &&
1742 (action == SIG_DFL))
1743 return;
1744 SIG_CONTSIGMASK(p->p_siglist);
1745 mtx_lock_spin(&sched_lock);
1746 FOREACH_THREAD_IN_PROC(p, td0)
1747 SIG_CONTSIGMASK(td0->td_siglist);
1748 mtx_unlock_spin(&sched_lock);
1749 p->p_flag &= ~P_CONTINUED;
1750 }
1751
1752 SIGADDSET(*siglist, sig);
1753 signotify(td); /* uses schedlock */
1754 /*
1755 * Defer further processing for signals which are held,
1756 * except that stopped processes must be continued by SIGCONT.
1757 */
1758 if (action == SIG_HOLD &&
1759 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG)))
1760 return;
1761 /*
1762 * SIGKILL: Remove procfs STOPEVENTs.
1763 */
1764 if (sig == SIGKILL) {
1765 /* from procfs_ioctl.c: PIOCBIC */
1766 p->p_stops = 0;
1767 /* from procfs_ioctl.c: PIOCCONT */
1768 p->p_step = 0;
1769 wakeup(&p->p_step);
1770 }
1771 /*
1772 * Some signals have a process-wide effect and a per-thread
1773 * component. Most processing occurs when the process next
1774 * tries to cross the user boundary, however there are some
1775 * times when processing needs to be done immediatly, such as
1776 * waking up threads so that they can cross the user boundary.
1777 * We try do the per-process part here.
1778 */
1779 if (P_SHOULDSTOP(p)) {
1780 /*
1781 * The process is in stopped mode. All the threads should be
1782 * either winding down or already on the suspended queue.
1783 */
1784 if (p->p_flag & P_TRACED) {
1785 /*
1786 * The traced process is already stopped,
1787 * so no further action is necessary.
1788 * No signal can restart us.
1789 */
1790 goto out;
1791 }
1792
1793 if (sig == SIGKILL) {
1794 /*
1795 * SIGKILL sets process running.
1796 * It will die elsewhere.
1797 * All threads must be restarted.
1798 */
1799 p->p_flag &= ~P_STOPPED_SIG;
1800 goto runfast;
1801 }
1802
1803 if (prop & SA_CONT) {
1804 /*
1805 * If SIGCONT is default (or ignored), we continue the
1806 * process but don't leave the signal in siglist as
1807 * it has no further action. If SIGCONT is held, we
1808 * continue the process and leave the signal in
1809 * siglist. If the process catches SIGCONT, let it
1810 * handle the signal itself. If it isn't waiting on
1811 * an event, it goes back to run state.
1812 * Otherwise, process goes back to sleep state.
1813 */
1814 p->p_flag &= ~P_STOPPED_SIG;
1815 p->p_flag |= P_CONTINUED;
1816 if (action == SIG_DFL) {
1817 SIGDELSET(*siglist, sig);
1818 } else if (action == SIG_CATCH) {
1819 /*
1820 * The process wants to catch it so it needs
1821 * to run at least one thread, but which one?
1822 * It would seem that the answer would be to
1823 * run an upcall in the next KSE to run, and
1824 * deliver the signal that way. In a NON KSE
1825 * process, we need to make sure that the
1826 * single thread is runnable asap.
1827 * XXXKSE for now however, make them all run.
1828 */
1829 goto runfast;
1830 }
1831 /*
1832 * The signal is not ignored or caught.
1833 */
1834 mtx_lock_spin(&sched_lock);
1835 thread_unsuspend(p);
1836 mtx_unlock_spin(&sched_lock);
1837 goto out;
1838 }
1839
1840 if (prop & SA_STOP) {
1841 /*
1842 * Already stopped, don't need to stop again
1843 * (If we did the shell could get confused).
1844 * Just make sure the signal STOP bit set.
1845 */
1846 p->p_flag |= P_STOPPED_SIG;
1847 SIGDELSET(*siglist, sig);
1848 goto out;
1849 }
1850
1851 /*
1852 * All other kinds of signals:
1853 * If a thread is sleeping interruptibly, simulate a
1854 * wakeup so that when it is continued it will be made
1855 * runnable and can look at the signal. However, don't make
1856 * the PROCESS runnable, leave it stopped.
1857 * It may run a bit until it hits a thread_suspend_check().
1858 */
1859 mtx_lock_spin(&sched_lock);
1860 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR))
1861 sleepq_abort(td);
1862 mtx_unlock_spin(&sched_lock);
1863 goto out;
1864 /*
1865 * Mutexes are short lived. Threads waiting on them will
1866 * hit thread_suspend_check() soon.
1867 */
1868 } else if (p->p_state == PRS_NORMAL) {
1869 if ((p->p_flag & P_TRACED) || (action != SIG_DFL) ||
1870 !(prop & SA_STOP)) {
1871 mtx_lock_spin(&sched_lock);
1872 tdsigwakeup(td, sig, action);
1873 mtx_unlock_spin(&sched_lock);
1874 goto out;
1875 }
1876 if (prop & SA_STOP) {
1877 if (p->p_flag & P_PPWAIT)
1878 goto out;
1879 p->p_flag |= P_STOPPED_SIG;
1880 p->p_xstat = sig;
1881 p->p_xthread = td;
1882 mtx_lock_spin(&sched_lock);
1883 FOREACH_THREAD_IN_PROC(p, td0) {
1884 if (TD_IS_SLEEPING(td0) &&
1885 (td0->td_flags & TDF_SINTR) &&
1886 !TD_IS_SUSPENDED(td0)) {
1887 thread_suspend_one(td0);
1888 } else if (td != td0) {
1889 td0->td_flags |= TDF_ASTPENDING;
1890 }
1891 }
1892 thread_stopped(p);
1893 if (p->p_numthreads == p->p_suspcount) {
1894 SIGDELSET(p->p_siglist, p->p_xstat);
1895 FOREACH_THREAD_IN_PROC(p, td0)
1896 SIGDELSET(td0->td_siglist, p->p_xstat);
1897 }
1898 mtx_unlock_spin(&sched_lock);
1899 goto out;
1900 }
1901 else
1902 goto runfast;
1903 /* NOTREACHED */
1904 } else {
1905 /* Not in "NORMAL" state. discard the signal. */
1906 SIGDELSET(*siglist, sig);
1907 goto out;
1908 }
1909
1910 /*
1911 * The process is not stopped so we need to apply the signal to all the
1912 * running threads.
1913 */
1914
1915 runfast:
1916 mtx_lock_spin(&sched_lock);
1917 tdsigwakeup(td, sig, action);
1918 thread_unsuspend(p);
1919 mtx_unlock_spin(&sched_lock);
1920 out:
1921 /* If we jump here, sched_lock should not be owned. */
1922 mtx_assert(&sched_lock, MA_NOTOWNED);
1923 }
1924
1925 /*
1926 * The force of a signal has been directed against a single
1927 * thread. We need to see what we can do about knocking it
1928 * out of any sleep it may be in etc.
1929 */
1930 static void
1931 tdsigwakeup(struct thread *td, int sig, sig_t action)
1932 {
1933 struct proc *p = td->td_proc;
1934 register int prop;
1935
1936 PROC_LOCK_ASSERT(p, MA_OWNED);
1937 mtx_assert(&sched_lock, MA_OWNED);
1938 prop = sigprop(sig);
1939
1940 /*
1941 * Bring the priority of a thread up if we want it to get
1942 * killed in this lifetime.
1943 */
1944 if (action == SIG_DFL && (prop & SA_KILL)) {
1945 if (td->td_priority > PUSER)
1946 td->td_priority = PUSER;
1947 }
1948
1949 if (TD_ON_SLEEPQ(td)) {
1950 /*
1951 * If thread is sleeping uninterruptibly
1952 * we can't interrupt the sleep... the signal will
1953 * be noticed when the process returns through
1954 * trap() or syscall().
1955 */
1956 if ((td->td_flags & TDF_SINTR) == 0)
1957 return;
1958 /*
1959 * Process is sleeping and traced. Make it runnable
1960 * so it can discover the signal in issignal() and stop
1961 * for its parent.
1962 */
1963 if (p->p_flag & P_TRACED) {
1964 p->p_flag &= ~P_STOPPED_TRACE;
1965 } else {
1966 /*
1967 * If SIGCONT is default (or ignored) and process is
1968 * asleep, we are finished; the process should not
1969 * be awakened.
1970 */
1971 if ((prop & SA_CONT) && action == SIG_DFL) {
1972 SIGDELSET(p->p_siglist, sig);
1973 /*
1974 * It may be on either list in this state.
1975 * Remove from both for now.
1976 */
1977 SIGDELSET(td->td_siglist, sig);
1978 return;
1979 }
1980
1981 /*
1982 * Give low priority threads a better chance to run.
1983 */
1984 if (td->td_priority > PUSER)
1985 td->td_priority = PUSER;
1986 }
1987 sleepq_abort(td);
1988 } else {
1989 /*
1990 * Other states do nothing with the signal immediately,
1991 * other than kicking ourselves if we are running.
1992 * It will either never be noticed, or noticed very soon.
1993 */
1994 #ifdef SMP
1995 if (TD_IS_RUNNING(td) && td != curthread)
1996 forward_signal(td);
1997 #endif
1998 }
1999 }
2000
2001 int
2002 ptracestop(struct thread *td, int sig)
2003 {
2004 struct proc *p = td->td_proc;
2005 struct thread *td0;
2006
2007 PROC_LOCK_ASSERT(p, MA_OWNED);
2008 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
2009 &p->p_mtx.mtx_object, "Stopping for traced signal");
2010
2011 mtx_lock_spin(&sched_lock);
2012 td->td_flags |= TDF_XSIG;
2013 mtx_unlock_spin(&sched_lock);
2014 td->td_xsig = sig;
2015 while ((p->p_flag & P_TRACED) && (td->td_flags & TDF_XSIG)) {
2016 if (p->p_flag & P_SINGLE_EXIT) {
2017 mtx_lock_spin(&sched_lock);
2018 td->td_flags &= ~TDF_XSIG;
2019 mtx_unlock_spin(&sched_lock);
2020 return (sig);
2021 }
2022 /*
2023 * Just make wait() to work, the last stopped thread
2024 * will win.
2025 */
2026 p->p_xstat = sig;
2027 p->p_xthread = td;
2028 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE);
2029 mtx_lock_spin(&sched_lock);
2030 FOREACH_THREAD_IN_PROC(p, td0) {
2031 if (TD_IS_SLEEPING(td0) &&
2032 (td0->td_flags & TDF_SINTR) &&
2033 !TD_IS_SUSPENDED(td0)) {
2034 thread_suspend_one(td0);
2035 } else if (td != td0) {
2036 td0->td_flags |= TDF_ASTPENDING;
2037 }
2038 }
2039 stopme:
2040 thread_stopped(p);
2041 thread_suspend_one(td);
2042 PROC_UNLOCK(p);
2043 DROP_GIANT();
2044 mi_switch(SW_VOL, NULL);
2045 mtx_unlock_spin(&sched_lock);
2046 PICKUP_GIANT();
2047 PROC_LOCK(p);
2048 if (!(p->p_flag & P_TRACED))
2049 break;
2050 if (td->td_flags & TDF_DBSUSPEND) {
2051 if (p->p_flag & P_SINGLE_EXIT)
2052 break;
2053 mtx_lock_spin(&sched_lock);
2054 goto stopme;
2055 }
2056 }
2057 return (td->td_xsig);
2058 }
2059
2060 /*
2061 * If the current process has received a signal (should be caught or cause
2062 * termination, should interrupt current syscall), return the signal number.
2063 * Stop signals with default action are processed immediately, then cleared;
2064 * they aren't returned. This is checked after each entry to the system for
2065 * a syscall or trap (though this can usually be done without calling issignal
2066 * by checking the pending signal masks in cursig.) The normal call
2067 * sequence is
2068 *
2069 * while (sig = cursig(curthread))
2070 * postsig(sig);
2071 */
2072 static int
2073 issignal(td)
2074 struct thread *td;
2075 {
2076 struct proc *p;
2077 struct sigacts *ps;
2078 sigset_t sigpending;
2079 int sig, prop, newsig;
2080 struct thread *td0;
2081
2082 p = td->td_proc;
2083 ps = p->p_sigacts;
2084 mtx_assert(&ps->ps_mtx, MA_OWNED);
2085 PROC_LOCK_ASSERT(p, MA_OWNED);
2086 for (;;) {
2087 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
2088
2089 sigpending = td->td_siglist;
2090 SIGSETNAND(sigpending, td->td_sigmask);
2091
2092 if (p->p_flag & P_PPWAIT)
2093 SIG_STOPSIGMASK(sigpending);
2094 if (SIGISEMPTY(sigpending)) /* no signal to send */
2095 return (0);
2096 sig = sig_ffs(&sigpending);
2097
2098 if (p->p_stops & S_SIG) {
2099 mtx_unlock(&ps->ps_mtx);
2100 stopevent(p, S_SIG, sig);
2101 mtx_lock(&ps->ps_mtx);
2102 }
2103
2104 /*
2105 * We should see pending but ignored signals
2106 * only if P_TRACED was on when they were posted.
2107 */
2108 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) {
2109 SIGDELSET(td->td_siglist, sig);
2110 if (td->td_pflags & TDP_SA)
2111 SIGADDSET(td->td_sigmask, sig);
2112 continue;
2113 }
2114 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) {
2115 /*
2116 * If traced, always stop.
2117 */
2118 mtx_unlock(&ps->ps_mtx);
2119 newsig = ptracestop(td, sig);
2120 mtx_lock(&ps->ps_mtx);
2121
2122 /*
2123 * If parent wants us to take the signal,
2124 * then it will leave it in p->p_xstat;
2125 * otherwise we just look for signals again.
2126 */
2127 SIGDELSET(td->td_siglist, sig); /* clear old signal */
2128 if (td->td_pflags & TDP_SA)
2129 SIGADDSET(td->td_sigmask, sig);
2130 if (newsig == 0)
2131 continue;
2132 sig = newsig;
2133 /*
2134 * If the traced bit got turned off, go back up
2135 * to the top to rescan signals. This ensures
2136 * that p_sig* and p_sigact are consistent.
2137 */
2138 if ((p->p_flag & P_TRACED) == 0)
2139 continue;
2140
2141 /*
2142 * Put the new signal into td_siglist. If the
2143 * signal is being masked, look for other signals.
2144 */
2145 SIGADDSET(td->td_siglist, sig);
2146 if (td->td_pflags & TDP_SA)
2147 SIGDELSET(td->td_sigmask, sig);
2148 if (SIGISMEMBER(td->td_sigmask, sig))
2149 continue;
2150 signotify(td);
2151 }
2152
2153 prop = sigprop(sig);
2154
2155 /*
2156 * Decide whether the signal should be returned.
2157 * Return the signal's number, or fall through
2158 * to clear it from the pending mask.
2159 */
2160 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
2161
2162 case (intptr_t)SIG_DFL:
2163 /*
2164 * Don't take default actions on system processes.
2165 */
2166 if (p->p_pid <= 1) {
2167 #ifdef DIAGNOSTIC
2168 /*
2169 * Are you sure you want to ignore SIGSEGV
2170 * in init? XXX
2171 */
2172 printf("Process (pid %lu) got signal %d\n",
2173 (u_long)p->p_pid, sig);
2174 #endif
2175 break; /* == ignore */
2176 }
2177 /*
2178 * If there is a pending stop signal to process
2179 * with default action, stop here,
2180 * then clear the signal. However,
2181 * if process is member of an orphaned
2182 * process group, ignore tty stop signals.
2183 */
2184 if (prop & SA_STOP) {
2185 if (p->p_flag & P_TRACED ||
2186 (p->p_pgrp->pg_jobc == 0 &&
2187 prop & SA_TTYSTOP))
2188 break; /* == ignore */
2189 mtx_unlock(&ps->ps_mtx);
2190 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
2191 &p->p_mtx.mtx_object, "Catching SIGSTOP");
2192 p->p_flag |= P_STOPPED_SIG;
2193 p->p_xstat = sig;
2194 p->p_xthread = td;
2195 mtx_lock_spin(&sched_lock);
2196 FOREACH_THREAD_IN_PROC(p, td0) {
2197 if (TD_IS_SLEEPING(td0) &&
2198 (td0->td_flags & TDF_SINTR) &&
2199 !TD_IS_SUSPENDED(td0)) {
2200 thread_suspend_one(td0);
2201 } else if (td != td0) {
2202 td0->td_flags |= TDF_ASTPENDING;
2203 }
2204 }
2205 thread_stopped(p);
2206 thread_suspend_one(td);
2207 PROC_UNLOCK(p);
2208 DROP_GIANT();
2209 mi_switch(SW_INVOL, NULL);
2210 mtx_unlock_spin(&sched_lock);
2211 PICKUP_GIANT();
2212 PROC_LOCK(p);
2213 mtx_lock(&ps->ps_mtx);
2214 break;
2215 } else if (prop & SA_IGNORE) {
2216 /*
2217 * Except for SIGCONT, shouldn't get here.
2218 * Default action is to ignore; drop it.
2219 */
2220 break; /* == ignore */
2221 } else
2222 return (sig);
2223 /*NOTREACHED*/
2224
2225 case (intptr_t)SIG_IGN:
2226 /*
2227 * Masking above should prevent us ever trying
2228 * to take action on an ignored signal other
2229 * than SIGCONT, unless process is traced.
2230 */
2231 if ((prop & SA_CONT) == 0 &&
2232 (p->p_flag & P_TRACED) == 0)
2233 printf("issignal\n");
2234 break; /* == ignore */
2235
2236 default:
2237 /*
2238 * This signal has an action, let
2239 * postsig() process it.
2240 */
2241 return (sig);
2242 }
2243 SIGDELSET(td->td_siglist, sig); /* take the signal! */
2244 }
2245 /* NOTREACHED */
2246 }
2247
2248 /*
2249 * MPSAFE
2250 */
2251 void
2252 thread_stopped(struct proc *p)
2253 {
2254 struct proc *p1 = curthread->td_proc;
2255 struct sigacts *ps;
2256 int n;
2257
2258 PROC_LOCK_ASSERT(p, MA_OWNED);
2259 mtx_assert(&sched_lock, MA_OWNED);
2260 n = p->p_suspcount;
2261 if (p == p1)
2262 n++;
2263 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) {
2264 mtx_unlock_spin(&sched_lock);
2265 p->p_flag &= ~P_WAITED;
2266 PROC_LOCK(p->p_pptr);
2267 /*
2268 * Wake up parent sleeping in kern_wait(), also send
2269 * SIGCHLD to parent, but SIGCHLD does not guarantee
2270 * that parent will awake, because parent may masked
2271 * the signal.
2272 */
2273 p->p_pptr->p_flag |= P_STATCHILD;
2274 wakeup(p->p_pptr);
2275 ps = p->p_pptr->p_sigacts;
2276 mtx_lock(&ps->ps_mtx);
2277 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) {
2278 mtx_unlock(&ps->ps_mtx);
2279 psignal(p->p_pptr, SIGCHLD);
2280 } else
2281 mtx_unlock(&ps->ps_mtx);
2282 PROC_UNLOCK(p->p_pptr);
2283 mtx_lock_spin(&sched_lock);
2284 }
2285 }
2286
2287 /*
2288 * Take the action for the specified signal
2289 * from the current set of pending signals.
2290 */
2291 void
2292 postsig(sig)
2293 register int sig;
2294 {
2295 struct thread *td = curthread;
2296 register struct proc *p = td->td_proc;
2297 struct sigacts *ps;
2298 sig_t action;
2299 sigset_t returnmask;
2300 int code;
2301
2302 KASSERT(sig != 0, ("postsig"));
2303
2304 PROC_LOCK_ASSERT(p, MA_OWNED);
2305 ps = p->p_sigacts;
2306 mtx_assert(&ps->ps_mtx, MA_OWNED);
2307 SIGDELSET(td->td_siglist, sig);
2308 action = ps->ps_sigact[_SIG_IDX(sig)];
2309 #ifdef KTRACE
2310 if (KTRPOINT(td, KTR_PSIG))
2311 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ?
2312 &td->td_oldsigmask : &td->td_sigmask, 0);
2313 #endif
2314 if (p->p_stops & S_SIG) {
2315 mtx_unlock(&ps->ps_mtx);
2316 stopevent(p, S_SIG, sig);
2317 mtx_lock(&ps->ps_mtx);
2318 }
2319
2320 if (!(td->td_pflags & TDP_SA) && action == SIG_DFL) {
2321 /*
2322 * Default action, where the default is to kill
2323 * the process. (Other cases were ignored above.)
2324 */
2325 mtx_unlock(&ps->ps_mtx);
2326 sigexit(td, sig);
2327 /* NOTREACHED */
2328 } else {
2329 if (td->td_pflags & TDP_SA) {
2330 if (sig == SIGKILL) {
2331 mtx_unlock(&ps->ps_mtx);
2332 sigexit(td, sig);
2333 }
2334 }
2335
2336 /*
2337 * If we get here, the signal must be caught.
2338 */
2339 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig),
2340 ("postsig action"));
2341 /*
2342 * Set the new mask value and also defer further
2343 * occurrences of this signal.
2344 *
2345 * Special case: user has done a sigsuspend. Here the
2346 * current mask is not of interest, but rather the
2347 * mask from before the sigsuspend is what we want
2348 * restored after the signal processing is completed.
2349 */
2350 if (td->td_pflags & TDP_OLDMASK) {
2351 returnmask = td->td_oldsigmask;
2352 td->td_pflags &= ~TDP_OLDMASK;
2353 } else
2354 returnmask = td->td_sigmask;
2355
2356 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
2357 if (!SIGISMEMBER(ps->ps_signodefer, sig))
2358 SIGADDSET(td->td_sigmask, sig);
2359
2360 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
2361 /*
2362 * See kern_sigaction() for origin of this code.
2363 */
2364 SIGDELSET(ps->ps_sigcatch, sig);
2365 if (sig != SIGCONT &&
2366 sigprop(sig) & SA_IGNORE)
2367 SIGADDSET(ps->ps_sigignore, sig);
2368 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
2369 }
2370 p->p_stats->p_ru.ru_nsignals++;
2371 if (p->p_sig != sig) {
2372 code = 0;
2373 } else {
2374 code = p->p_code;
2375 p->p_code = 0;
2376 p->p_sig = 0;
2377 }
2378 if (td->td_pflags & TDP_SA)
2379 thread_signal_add(curthread, sig);
2380 else
2381 (*p->p_sysent->sv_sendsig)(action, sig,
2382 &returnmask, code);
2383 }
2384 }
2385
2386 /*
2387 * Kill the current process for stated reason.
2388 */
2389 void
2390 killproc(p, why)
2391 struct proc *p;
2392 char *why;
2393 {
2394
2395 PROC_LOCK_ASSERT(p, MA_OWNED);
2396 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)",
2397 p, p->p_pid, p->p_comm);
2398 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm,
2399 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
2400 psignal(p, SIGKILL);
2401 }
2402
2403 /*
2404 * Force the current process to exit with the specified signal, dumping core
2405 * if appropriate. We bypass the normal tests for masked and caught signals,
2406 * allowing unrecoverable failures to terminate the process without changing
2407 * signal state. Mark the accounting record with the signal termination.
2408 * If dumping core, save the signal number for the debugger. Calls exit and
2409 * does not return.
2410 *
2411 * MPSAFE
2412 */
2413 void
2414 sigexit(td, sig)
2415 struct thread *td;
2416 int sig;
2417 {
2418 struct proc *p = td->td_proc;
2419
2420 PROC_LOCK_ASSERT(p, MA_OWNED);
2421 p->p_acflag |= AXSIG;
2422 if (sigprop(sig) & SA_CORE) {
2423 p->p_sig = sig;
2424 /*
2425 * Log signals which would cause core dumps
2426 * (Log as LOG_INFO to appease those who don't want
2427 * these messages.)
2428 * XXX : Todo, as well as euid, write out ruid too
2429 * Note that coredump() drops proc lock.
2430 */
2431 if (coredump(td) == 0)
2432 sig |= WCOREFLAG;
2433 if (kern_logsigexit)
2434 log(LOG_INFO,
2435 "pid %d (%s), uid %d: exited on signal %d%s\n",
2436 p->p_pid, p->p_comm,
2437 td->td_ucred ? td->td_ucred->cr_uid : -1,
2438 sig &~ WCOREFLAG,
2439 sig & WCOREFLAG ? " (core dumped)" : "");
2440 } else
2441 PROC_UNLOCK(p);
2442 exit1(td, W_EXITCODE(0, sig));
2443 /* NOTREACHED */
2444 }
2445
2446 static char corefilename[MAXPATHLEN+1] = {"%N.core"};
2447 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
2448 sizeof(corefilename), "process corefile name format string");
2449
2450 /*
2451 * expand_name(name, uid, pid)
2452 * Expand the name described in corefilename, using name, uid, and pid.
2453 * corefilename is a printf-like string, with three format specifiers:
2454 * %N name of process ("name")
2455 * %P process id (pid)
2456 * %U user id (uid)
2457 * For example, "%N.core" is the default; they can be disabled completely
2458 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
2459 * This is controlled by the sysctl variable kern.corefile (see above).
2460 */
2461
2462 static char *
2463 expand_name(name, uid, pid)
2464 const char *name;
2465 uid_t uid;
2466 pid_t pid;
2467 {
2468 const char *format, *appendstr;
2469 char *temp;
2470 char buf[11]; /* Buffer for pid/uid -- max 4B */
2471 size_t i, l, n;
2472
2473 format = corefilename;
2474 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO);
2475 if (temp == NULL)
2476 return (NULL);
2477 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
2478 switch (format[i]) {
2479 case '%': /* Format character */
2480 i++;
2481 switch (format[i]) {
2482 case '%':
2483 appendstr = "%";
2484 break;
2485 case 'N': /* process name */
2486 appendstr = name;
2487 break;
2488 case 'P': /* process id */
2489 sprintf(buf, "%u", pid);
2490 appendstr = buf;
2491 break;
2492 case 'U': /* user id */
2493 sprintf(buf, "%u", uid);
2494 appendstr = buf;
2495 break;
2496 default:
2497 appendstr = "";
2498 log(LOG_ERR,
2499 "Unknown format character %c in `%s'\n",
2500 format[i], format);
2501 }
2502 l = strlen(appendstr);
2503 if ((n + l) >= MAXPATHLEN)
2504 goto toolong;
2505 memcpy(temp + n, appendstr, l);
2506 n += l;
2507 break;
2508 default:
2509 temp[n++] = format[i];
2510 }
2511 }
2512 if (format[i] != '\0')
2513 goto toolong;
2514 return (temp);
2515 toolong:
2516 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too long\n",
2517 (long)pid, name, (u_long)uid);
2518 free(temp, M_TEMP);
2519 return (NULL);
2520 }
2521
2522 /*
2523 * Dump a process' core. The main routine does some
2524 * policy checking, and creates the name of the coredump;
2525 * then it passes on a vnode and a size limit to the process-specific
2526 * coredump routine if there is one; if there _is not_ one, it returns
2527 * ENOSYS; otherwise it returns the error from the process-specific routine.
2528 */
2529
2530 static int
2531 coredump(struct thread *td)
2532 {
2533 struct proc *p = td->td_proc;
2534 register struct vnode *vp;
2535 register struct ucred *cred = td->td_ucred;
2536 struct flock lf;
2537 struct nameidata nd;
2538 struct vattr vattr;
2539 int error, error1, flags, locked;
2540 struct mount *mp;
2541 char *name; /* name of corefile */
2542 off_t limit;
2543
2544 PROC_LOCK_ASSERT(p, MA_OWNED);
2545 _STOPEVENT(p, S_CORE, 0);
2546
2547 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) {
2548 PROC_UNLOCK(p);
2549 return (EFAULT);
2550 }
2551
2552 /*
2553 * Note that the bulk of limit checking is done after
2554 * the corefile is created. The exception is if the limit
2555 * for corefiles is 0, in which case we don't bother
2556 * creating the corefile at all. This layout means that
2557 * a corefile is truncated instead of not being created,
2558 * if it is larger than the limit.
2559 */
2560 limit = (off_t)lim_cur(p, RLIMIT_CORE);
2561 PROC_UNLOCK(p);
2562 if (limit == 0)
2563 return (EFBIG);
2564
2565 mtx_lock(&Giant);
2566 restart:
2567 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid);
2568 if (name == NULL) {
2569 mtx_unlock(&Giant);
2570 return (EINVAL);
2571 }
2572 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); /* XXXKSE */
2573 flags = O_CREAT | FWRITE | O_NOFOLLOW;
2574 error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR, -1);
2575 free(name, M_TEMP);
2576 if (error) {
2577 mtx_unlock(&Giant);
2578 return (error);
2579 }
2580 NDFREE(&nd, NDF_ONLY_PNBUF);
2581 vp = nd.ni_vp;
2582
2583 /* Don't dump to non-regular files or files with links. */
2584 if (vp->v_type != VREG ||
2585 VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) {
2586 VOP_UNLOCK(vp, 0, td);
2587 error = EFAULT;
2588 goto out;
2589 }
2590
2591 VOP_UNLOCK(vp, 0, td);
2592 lf.l_whence = SEEK_SET;
2593 lf.l_start = 0;
2594 lf.l_len = 0;
2595 lf.l_type = F_WRLCK;
2596 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0);
2597
2598 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
2599 lf.l_type = F_UNLCK;
2600 if (locked)
2601 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
2602 if ((error = vn_close(vp, FWRITE, cred, td)) != 0)
2603 return (error);
2604 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
2605 return (error);
2606 goto restart;
2607 }
2608
2609 VATTR_NULL(&vattr);
2610 vattr.va_size = 0;
2611 if (set_core_nodump_flag)
2612 vattr.va_flags = UF_NODUMP;
2613 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
2614 VOP_LEASE(vp, td, cred, LEASE_WRITE);
2615 VOP_SETATTR(vp, &vattr, cred, td);
2616 VOP_UNLOCK(vp, 0, td);
2617 PROC_LOCK(p);
2618 p->p_acflag |= ACORE;
2619 PROC_UNLOCK(p);
2620
2621 error = p->p_sysent->sv_coredump ?
2622 p->p_sysent->sv_coredump(td, vp, limit) :
2623 ENOSYS;
2624
2625 if (locked) {
2626 lf.l_type = F_UNLCK;
2627 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
2628 }
2629 vn_finished_write(mp);
2630 out:
2631 error1 = vn_close(vp, FWRITE, cred, td);
2632 mtx_unlock(&Giant);
2633 if (error == 0)
2634 error = error1;
2635 return (error);
2636 }
2637
2638 /*
2639 * Nonexistent system call-- signal process (may want to handle it).
2640 * Flag error in case process won't see signal immediately (blocked or ignored).
2641 */
2642 #ifndef _SYS_SYSPROTO_H_
2643 struct nosys_args {
2644 int dummy;
2645 };
2646 #endif
2647 /*
2648 * MPSAFE
2649 */
2650 /* ARGSUSED */
2651 int
2652 nosys(td, args)
2653 struct thread *td;
2654 struct nosys_args *args;
2655 {
2656 struct proc *p = td->td_proc;
2657
2658 PROC_LOCK(p);
2659 psignal(p, SIGSYS);
2660 PROC_UNLOCK(p);
2661 return (ENOSYS);
2662 }
2663
2664 /*
2665 * Send a SIGIO or SIGURG signal to a process or process group using
2666 * stored credentials rather than those of the current process.
2667 */
2668 void
2669 pgsigio(sigiop, sig, checkctty)
2670 struct sigio **sigiop;
2671 int sig, checkctty;
2672 {
2673 struct sigio *sigio;
2674
2675 SIGIO_LOCK();
2676 sigio = *sigiop;
2677 if (sigio == NULL) {
2678 SIGIO_UNLOCK();
2679 return;
2680 }
2681 if (sigio->sio_pgid > 0) {
2682 PROC_LOCK(sigio->sio_proc);
2683 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred))
2684 psignal(sigio->sio_proc, sig);
2685 PROC_UNLOCK(sigio->sio_proc);
2686 } else if (sigio->sio_pgid < 0) {
2687 struct proc *p;
2688
2689 PGRP_LOCK(sigio->sio_pgrp);
2690 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
2691 PROC_LOCK(p);
2692 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) &&
2693 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
2694 psignal(p, sig);
2695 PROC_UNLOCK(p);
2696 }
2697 PGRP_UNLOCK(sigio->sio_pgrp);
2698 }
2699 SIGIO_UNLOCK();
2700 }
2701
2702 static int
2703 filt_sigattach(struct knote *kn)
2704 {
2705 struct proc *p = curproc;
2706
2707 kn->kn_ptr.p_proc = p;
2708 kn->kn_flags |= EV_CLEAR; /* automatically set */
2709
2710 knlist_add(&p->p_klist, kn, 0);
2711
2712 return (0);
2713 }
2714
2715 static void
2716 filt_sigdetach(struct knote *kn)
2717 {
2718 struct proc *p = kn->kn_ptr.p_proc;
2719
2720 knlist_remove(&p->p_klist, kn, 0);
2721 }
2722
2723 /*
2724 * signal knotes are shared with proc knotes, so we apply a mask to
2725 * the hint in order to differentiate them from process hints. This
2726 * could be avoided by using a signal-specific knote list, but probably
2727 * isn't worth the trouble.
2728 */
2729 static int
2730 filt_signal(struct knote *kn, long hint)
2731 {
2732
2733 if (hint & NOTE_SIGNAL) {
2734 hint &= ~NOTE_SIGNAL;
2735
2736 if (kn->kn_id == hint)
2737 kn->kn_data++;
2738 }
2739 return (kn->kn_data != 0);
2740 }
2741
2742 struct sigacts *
2743 sigacts_alloc(void)
2744 {
2745 struct sigacts *ps;
2746
2747 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO);
2748 ps->ps_refcnt = 1;
2749 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF);
2750 return (ps);
2751 }
2752
2753 void
2754 sigacts_free(struct sigacts *ps)
2755 {
2756
2757 mtx_lock(&ps->ps_mtx);
2758 ps->ps_refcnt--;
2759 if (ps->ps_refcnt == 0) {
2760 mtx_destroy(&ps->ps_mtx);
2761 free(ps, M_SUBPROC);
2762 } else
2763 mtx_unlock(&ps->ps_mtx);
2764 }
2765
2766 struct sigacts *
2767 sigacts_hold(struct sigacts *ps)
2768 {
2769 mtx_lock(&ps->ps_mtx);
2770 ps->ps_refcnt++;
2771 mtx_unlock(&ps->ps_mtx);
2772 return (ps);
2773 }
2774
2775 void
2776 sigacts_copy(struct sigacts *dest, struct sigacts *src)
2777 {
2778
2779 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest"));
2780 mtx_lock(&src->ps_mtx);
2781 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt));
2782 mtx_unlock(&src->ps_mtx);
2783 }
2784
2785 int
2786 sigacts_shared(struct sigacts *ps)
2787 {
2788 int shared;
2789
2790 mtx_lock(&ps->ps_mtx);
2791 shared = ps->ps_refcnt > 1;
2792 mtx_unlock(&ps->ps_mtx);
2793 return (shared);
2794 }
Cache object: 745220517efd061d4c71a9d2a1796c8a
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