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("$FreeBSD$");
39
40 #include "opt_compat.h"
41 #include "opt_kdtrace.h"
42 #include "opt_ktrace.h"
43
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/signalvar.h>
47 #include <sys/vnode.h>
48 #include <sys/acct.h>
49 #include <sys/condvar.h>
50 #include <sys/event.h>
51 #include <sys/fcntl.h>
52 #include <sys/kernel.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/posix4.h>
61 #include <sys/pioctl.h>
62 #include <sys/resourcevar.h>
63 #include <sys/sdt.h>
64 #include <sys/sbuf.h>
65 #include <sys/sleepqueue.h>
66 #include <sys/smp.h>
67 #include <sys/stat.h>
68 #include <sys/sx.h>
69 #include <sys/syscallsubr.h>
70 #include <sys/sysctl.h>
71 #include <sys/sysent.h>
72 #include <sys/syslog.h>
73 #include <sys/sysproto.h>
74 #include <sys/timers.h>
75 #include <sys/unistd.h>
76 #include <sys/wait.h>
77 #include <vm/vm.h>
78 #include <vm/vm_extern.h>
79 #include <vm/uma.h>
80
81 #include <machine/cpu.h>
82
83 #include <security/audit/audit.h>
84
85 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */
86
87 SDT_PROVIDER_DECLARE(proc);
88 SDT_PROBE_DEFINE(proc, kernel, , signal_send, signal-send);
89 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 0, "struct thread *");
90 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 1, "struct proc *");
91 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 2, "int");
92 SDT_PROBE_DEFINE(proc, kernel, , signal_clear, signal-clear);
93 SDT_PROBE_ARGTYPE(proc, kernel, , signal_clear, 0, "int");
94 SDT_PROBE_ARGTYPE(proc, kernel, , signal_clear, 1, "ksiginfo_t *");
95 SDT_PROBE_DEFINE(proc, kernel, , signal_discard, signal-discard);
96 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 0, "struct thread *");
97 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 1, "struct proc *");
98 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 2, "int");
99
100 static int coredump(struct thread *);
101 static char *expand_name(const char *, uid_t, pid_t);
102 static int killpg1(struct thread *td, int sig, int pgid, int all,
103 ksiginfo_t *ksi);
104 static int issignal(struct thread *td, int stop_allowed);
105 static int sigprop(int sig);
106 static void tdsigwakeup(struct thread *, int, sig_t, int);
107 static void sig_suspend_threads(struct thread *, struct proc *, int);
108 static int filt_sigattach(struct knote *kn);
109 static void filt_sigdetach(struct knote *kn);
110 static int filt_signal(struct knote *kn, long hint);
111 static struct thread *sigtd(struct proc *p, int sig, int prop);
112 static void sigqueue_start(void);
113
114 static uma_zone_t ksiginfo_zone = NULL;
115 struct filterops sig_filtops =
116 { 0, filt_sigattach, filt_sigdetach, filt_signal };
117
118 int kern_logsigexit = 1;
119 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
120 &kern_logsigexit, 0,
121 "Log processes quitting on abnormal signals to syslog(3)");
122
123 static int kern_forcesigexit = 1;
124 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW,
125 &kern_forcesigexit, 0, "Force trap signal to be handled");
126
127 SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, "POSIX real time signal");
128
129 static int max_pending_per_proc = 128;
130 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW,
131 &max_pending_per_proc, 0, "Max pending signals per proc");
132
133 static int preallocate_siginfo = 1024;
134 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo);
135 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD,
136 &preallocate_siginfo, 0, "Preallocated signal memory size");
137
138 static int signal_overflow = 0;
139 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD,
140 &signal_overflow, 0, "Number of signals overflew");
141
142 static int signal_alloc_fail = 0;
143 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD,
144 &signal_alloc_fail, 0, "signals failed to be allocated");
145
146 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL);
147
148 /*
149 * Policy -- Can ucred cr1 send SIGIO to process cr2?
150 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG
151 * in the right situations.
152 */
153 #define CANSIGIO(cr1, cr2) \
154 ((cr1)->cr_uid == 0 || \
155 (cr1)->cr_ruid == (cr2)->cr_ruid || \
156 (cr1)->cr_uid == (cr2)->cr_ruid || \
157 (cr1)->cr_ruid == (cr2)->cr_uid || \
158 (cr1)->cr_uid == (cr2)->cr_uid)
159
160 int sugid_coredump;
161 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
162 &sugid_coredump, 0, "Enable coredumping set user/group ID processes");
163
164 static int do_coredump = 1;
165 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
166 &do_coredump, 0, "Enable/Disable coredumps");
167
168 static int set_core_nodump_flag = 0;
169 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag,
170 0, "Enable setting the NODUMP flag on coredump files");
171
172 /*
173 * Signal properties and actions.
174 * The array below categorizes the signals and their default actions
175 * according to the following properties:
176 */
177 #define SA_KILL 0x01 /* terminates process by default */
178 #define SA_CORE 0x02 /* ditto and coredumps */
179 #define SA_STOP 0x04 /* suspend process */
180 #define SA_TTYSTOP 0x08 /* ditto, from tty */
181 #define SA_IGNORE 0x10 /* ignore by default */
182 #define SA_CONT 0x20 /* continue if suspended */
183 #define SA_CANTMASK 0x40 /* non-maskable, catchable */
184 #define SA_PROC 0x80 /* deliverable to any thread */
185
186 static int sigproptbl[NSIG] = {
187 SA_KILL|SA_PROC, /* SIGHUP */
188 SA_KILL|SA_PROC, /* SIGINT */
189 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */
190 SA_KILL|SA_CORE, /* SIGILL */
191 SA_KILL|SA_CORE, /* SIGTRAP */
192 SA_KILL|SA_CORE, /* SIGABRT */
193 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */
194 SA_KILL|SA_CORE, /* SIGFPE */
195 SA_KILL|SA_PROC, /* SIGKILL */
196 SA_KILL|SA_CORE, /* SIGBUS */
197 SA_KILL|SA_CORE, /* SIGSEGV */
198 SA_KILL|SA_CORE, /* SIGSYS */
199 SA_KILL|SA_PROC, /* SIGPIPE */
200 SA_KILL|SA_PROC, /* SIGALRM */
201 SA_KILL|SA_PROC, /* SIGTERM */
202 SA_IGNORE|SA_PROC, /* SIGURG */
203 SA_STOP|SA_PROC, /* SIGSTOP */
204 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */
205 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */
206 SA_IGNORE|SA_PROC, /* SIGCHLD */
207 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */
208 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */
209 SA_IGNORE|SA_PROC, /* SIGIO */
210 SA_KILL, /* SIGXCPU */
211 SA_KILL, /* SIGXFSZ */
212 SA_KILL|SA_PROC, /* SIGVTALRM */
213 SA_KILL|SA_PROC, /* SIGPROF */
214 SA_IGNORE|SA_PROC, /* SIGWINCH */
215 SA_IGNORE|SA_PROC, /* SIGINFO */
216 SA_KILL|SA_PROC, /* SIGUSR1 */
217 SA_KILL|SA_PROC, /* SIGUSR2 */
218 };
219
220 static void reschedule_signals(struct proc *p, sigset_t block, int flags);
221
222 static void
223 sigqueue_start(void)
224 {
225 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t),
226 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
227 uma_prealloc(ksiginfo_zone, preallocate_siginfo);
228 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS);
229 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1);
230 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc);
231 }
232
233 ksiginfo_t *
234 ksiginfo_alloc(int wait)
235 {
236 int flags;
237
238 flags = M_ZERO;
239 if (! wait)
240 flags |= M_NOWAIT;
241 if (ksiginfo_zone != NULL)
242 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags));
243 return (NULL);
244 }
245
246 void
247 ksiginfo_free(ksiginfo_t *ksi)
248 {
249 uma_zfree(ksiginfo_zone, ksi);
250 }
251
252 static __inline int
253 ksiginfo_tryfree(ksiginfo_t *ksi)
254 {
255 if (!(ksi->ksi_flags & KSI_EXT)) {
256 uma_zfree(ksiginfo_zone, ksi);
257 return (1);
258 }
259 return (0);
260 }
261
262 void
263 sigqueue_init(sigqueue_t *list, struct proc *p)
264 {
265 SIGEMPTYSET(list->sq_signals);
266 SIGEMPTYSET(list->sq_kill);
267 TAILQ_INIT(&list->sq_list);
268 list->sq_proc = p;
269 list->sq_flags = SQ_INIT;
270 }
271
272 /*
273 * Get a signal's ksiginfo.
274 * Return:
275 * 0 - signal not found
276 * others - signal number
277 */
278 static int
279 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si)
280 {
281 struct proc *p = sq->sq_proc;
282 struct ksiginfo *ksi, *next;
283 int count = 0;
284
285 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
286
287 if (!SIGISMEMBER(sq->sq_signals, signo))
288 return (0);
289
290 if (SIGISMEMBER(sq->sq_kill, signo)) {
291 count++;
292 SIGDELSET(sq->sq_kill, signo);
293 }
294
295 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
296 if (ksi->ksi_signo == signo) {
297 if (count == 0) {
298 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
299 ksi->ksi_sigq = NULL;
300 ksiginfo_copy(ksi, si);
301 if (ksiginfo_tryfree(ksi) && p != NULL)
302 p->p_pendingcnt--;
303 }
304 if (++count > 1)
305 break;
306 }
307 }
308
309 if (count <= 1)
310 SIGDELSET(sq->sq_signals, signo);
311 si->ksi_signo = signo;
312 return (signo);
313 }
314
315 void
316 sigqueue_take(ksiginfo_t *ksi)
317 {
318 struct ksiginfo *kp;
319 struct proc *p;
320 sigqueue_t *sq;
321
322 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL)
323 return;
324
325 p = sq->sq_proc;
326 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
327 ksi->ksi_sigq = NULL;
328 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL)
329 p->p_pendingcnt--;
330
331 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL;
332 kp = TAILQ_NEXT(kp, ksi_link)) {
333 if (kp->ksi_signo == ksi->ksi_signo)
334 break;
335 }
336 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo))
337 SIGDELSET(sq->sq_signals, ksi->ksi_signo);
338 }
339
340 static int
341 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si)
342 {
343 struct proc *p = sq->sq_proc;
344 struct ksiginfo *ksi;
345 int ret = 0;
346
347 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
348
349 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) {
350 SIGADDSET(sq->sq_kill, signo);
351 goto out_set_bit;
352 }
353
354 /* directly insert the ksi, don't copy it */
355 if (si->ksi_flags & KSI_INS) {
356 if (si->ksi_flags & KSI_HEAD)
357 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link);
358 else
359 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link);
360 si->ksi_sigq = sq;
361 goto out_set_bit;
362 }
363
364 if (__predict_false(ksiginfo_zone == NULL)) {
365 SIGADDSET(sq->sq_kill, signo);
366 goto out_set_bit;
367 }
368
369 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) {
370 signal_overflow++;
371 ret = EAGAIN;
372 } else if ((ksi = ksiginfo_alloc(0)) == NULL) {
373 signal_alloc_fail++;
374 ret = EAGAIN;
375 } else {
376 if (p != NULL)
377 p->p_pendingcnt++;
378 ksiginfo_copy(si, ksi);
379 ksi->ksi_signo = signo;
380 if (si->ksi_flags & KSI_HEAD)
381 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link);
382 else
383 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link);
384 ksi->ksi_sigq = sq;
385 }
386
387 if ((si->ksi_flags & KSI_TRAP) != 0 ||
388 (si->ksi_flags & KSI_SIGQ) == 0) {
389 if (ret != 0)
390 SIGADDSET(sq->sq_kill, signo);
391 ret = 0;
392 goto out_set_bit;
393 }
394
395 if (ret != 0)
396 return (ret);
397
398 out_set_bit:
399 SIGADDSET(sq->sq_signals, signo);
400 return (ret);
401 }
402
403 void
404 sigqueue_flush(sigqueue_t *sq)
405 {
406 struct proc *p = sq->sq_proc;
407 ksiginfo_t *ksi;
408
409 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
410
411 if (p != NULL)
412 PROC_LOCK_ASSERT(p, MA_OWNED);
413
414 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) {
415 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
416 ksi->ksi_sigq = NULL;
417 if (ksiginfo_tryfree(ksi) && p != NULL)
418 p->p_pendingcnt--;
419 }
420
421 SIGEMPTYSET(sq->sq_signals);
422 SIGEMPTYSET(sq->sq_kill);
423 }
424
425 static void
426 sigqueue_collect_set(sigqueue_t *sq, sigset_t *set)
427 {
428 ksiginfo_t *ksi;
429
430 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
431
432 TAILQ_FOREACH(ksi, &sq->sq_list, ksi_link)
433 SIGADDSET(*set, ksi->ksi_signo);
434 SIGSETOR(*set, sq->sq_kill);
435 }
436
437 static void
438 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, sigset_t *setp)
439 {
440 sigset_t tmp, set;
441 struct proc *p1, *p2;
442 ksiginfo_t *ksi, *next;
443
444 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited"));
445 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited"));
446 /*
447 * make a copy, this allows setp to point to src or dst
448 * sq_signals without trouble.
449 */
450 set = *setp;
451 p1 = src->sq_proc;
452 p2 = dst->sq_proc;
453 /* Move siginfo to target list */
454 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) {
455 if (SIGISMEMBER(set, ksi->ksi_signo)) {
456 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link);
457 if (p1 != NULL)
458 p1->p_pendingcnt--;
459 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link);
460 ksi->ksi_sigq = dst;
461 if (p2 != NULL)
462 p2->p_pendingcnt++;
463 }
464 }
465
466 /* Move pending bits to target list */
467 tmp = src->sq_kill;
468 SIGSETAND(tmp, set);
469 SIGSETOR(dst->sq_kill, tmp);
470 SIGSETNAND(src->sq_kill, tmp);
471
472 tmp = src->sq_signals;
473 SIGSETAND(tmp, set);
474 SIGSETOR(dst->sq_signals, tmp);
475 SIGSETNAND(src->sq_signals, tmp);
476
477 /* Finally, rescan src queue and set pending bits for it */
478 sigqueue_collect_set(src, &src->sq_signals);
479 }
480
481 static void
482 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo)
483 {
484 sigset_t set;
485
486 SIGEMPTYSET(set);
487 SIGADDSET(set, signo);
488 sigqueue_move_set(src, dst, &set);
489 }
490
491 static void
492 sigqueue_delete_set(sigqueue_t *sq, sigset_t *set)
493 {
494 struct proc *p = sq->sq_proc;
495 ksiginfo_t *ksi, *next;
496
497 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited"));
498
499 /* Remove siginfo queue */
500 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
501 if (SIGISMEMBER(*set, ksi->ksi_signo)) {
502 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
503 ksi->ksi_sigq = NULL;
504 if (ksiginfo_tryfree(ksi) && p != NULL)
505 p->p_pendingcnt--;
506 }
507 }
508 SIGSETNAND(sq->sq_kill, *set);
509 SIGSETNAND(sq->sq_signals, *set);
510 /* Finally, rescan queue and set pending bits for it */
511 sigqueue_collect_set(sq, &sq->sq_signals);
512 }
513
514 void
515 sigqueue_delete(sigqueue_t *sq, int signo)
516 {
517 sigset_t set;
518
519 SIGEMPTYSET(set);
520 SIGADDSET(set, signo);
521 sigqueue_delete_set(sq, &set);
522 }
523
524 /* Remove a set of signals for a process */
525 static void
526 sigqueue_delete_set_proc(struct proc *p, sigset_t *set)
527 {
528 sigqueue_t worklist;
529 struct thread *td0;
530
531 PROC_LOCK_ASSERT(p, MA_OWNED);
532
533 sigqueue_init(&worklist, NULL);
534 sigqueue_move_set(&p->p_sigqueue, &worklist, set);
535
536 FOREACH_THREAD_IN_PROC(p, td0)
537 sigqueue_move_set(&td0->td_sigqueue, &worklist, set);
538
539 sigqueue_flush(&worklist);
540 }
541
542 void
543 sigqueue_delete_proc(struct proc *p, int signo)
544 {
545 sigset_t set;
546
547 SIGEMPTYSET(set);
548 SIGADDSET(set, signo);
549 sigqueue_delete_set_proc(p, &set);
550 }
551
552 static void
553 sigqueue_delete_stopmask_proc(struct proc *p)
554 {
555 sigset_t set;
556
557 SIGEMPTYSET(set);
558 SIGADDSET(set, SIGSTOP);
559 SIGADDSET(set, SIGTSTP);
560 SIGADDSET(set, SIGTTIN);
561 SIGADDSET(set, SIGTTOU);
562 sigqueue_delete_set_proc(p, &set);
563 }
564
565 /*
566 * Determine signal that should be delivered to process p, the current
567 * process, 0 if none. If there is a pending stop signal with default
568 * action, the process stops in issignal().
569 */
570 int
571 cursig(struct thread *td, int stop_allowed)
572 {
573 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
574 KASSERT(stop_allowed == SIG_STOP_ALLOWED ||
575 stop_allowed == SIG_STOP_NOT_ALLOWED, ("cursig: stop_allowed"));
576 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED);
577 THREAD_LOCK_ASSERT(td, MA_NOTOWNED);
578 return (SIGPENDING(td) ? issignal(td, stop_allowed) : 0);
579 }
580
581 /*
582 * Arrange for ast() to handle unmasked pending signals on return to user
583 * mode. This must be called whenever a signal is added to td_sigqueue or
584 * unmasked in td_sigmask.
585 */
586 void
587 signotify(struct thread *td)
588 {
589 struct proc *p;
590
591 p = td->td_proc;
592
593 PROC_LOCK_ASSERT(p, MA_OWNED);
594
595 if (SIGPENDING(td)) {
596 thread_lock(td);
597 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING;
598 thread_unlock(td);
599 }
600 }
601
602 int
603 sigonstack(size_t sp)
604 {
605 struct thread *td = curthread;
606
607 return ((td->td_pflags & TDP_ALTSTACK) ?
608 #if defined(COMPAT_43)
609 ((td->td_sigstk.ss_size == 0) ?
610 (td->td_sigstk.ss_flags & SS_ONSTACK) :
611 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size))
612 #else
613 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)
614 #endif
615 : 0);
616 }
617
618 static __inline int
619 sigprop(int sig)
620 {
621
622 if (sig > 0 && sig < NSIG)
623 return (sigproptbl[_SIG_IDX(sig)]);
624 return (0);
625 }
626
627 int
628 sig_ffs(sigset_t *set)
629 {
630 int i;
631
632 for (i = 0; i < _SIG_WORDS; i++)
633 if (set->__bits[i])
634 return (ffs(set->__bits[i]) + (i * 32));
635 return (0);
636 }
637
638 /*
639 * kern_sigaction
640 * sigaction
641 * freebsd4_sigaction
642 * osigaction
643 */
644 int
645 kern_sigaction(td, sig, act, oact, flags)
646 struct thread *td;
647 register int sig;
648 struct sigaction *act, *oact;
649 int flags;
650 {
651 struct sigacts *ps;
652 struct proc *p = td->td_proc;
653
654 if (!_SIG_VALID(sig))
655 return (EINVAL);
656
657 PROC_LOCK(p);
658 ps = p->p_sigacts;
659 mtx_lock(&ps->ps_mtx);
660 if (oact) {
661 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
662 oact->sa_flags = 0;
663 if (SIGISMEMBER(ps->ps_sigonstack, sig))
664 oact->sa_flags |= SA_ONSTACK;
665 if (!SIGISMEMBER(ps->ps_sigintr, sig))
666 oact->sa_flags |= SA_RESTART;
667 if (SIGISMEMBER(ps->ps_sigreset, sig))
668 oact->sa_flags |= SA_RESETHAND;
669 if (SIGISMEMBER(ps->ps_signodefer, sig))
670 oact->sa_flags |= SA_NODEFER;
671 if (SIGISMEMBER(ps->ps_siginfo, sig)) {
672 oact->sa_flags |= SA_SIGINFO;
673 oact->sa_sigaction =
674 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)];
675 } else
676 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
677 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP)
678 oact->sa_flags |= SA_NOCLDSTOP;
679 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT)
680 oact->sa_flags |= SA_NOCLDWAIT;
681 }
682 if (act) {
683 if ((sig == SIGKILL || sig == SIGSTOP) &&
684 act->sa_handler != SIG_DFL) {
685 mtx_unlock(&ps->ps_mtx);
686 PROC_UNLOCK(p);
687 return (EINVAL);
688 }
689
690 /*
691 * Change setting atomically.
692 */
693
694 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
695 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
696 if (act->sa_flags & SA_SIGINFO) {
697 ps->ps_sigact[_SIG_IDX(sig)] =
698 (__sighandler_t *)act->sa_sigaction;
699 SIGADDSET(ps->ps_siginfo, sig);
700 } else {
701 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
702 SIGDELSET(ps->ps_siginfo, sig);
703 }
704 if (!(act->sa_flags & SA_RESTART))
705 SIGADDSET(ps->ps_sigintr, sig);
706 else
707 SIGDELSET(ps->ps_sigintr, sig);
708 if (act->sa_flags & SA_ONSTACK)
709 SIGADDSET(ps->ps_sigonstack, sig);
710 else
711 SIGDELSET(ps->ps_sigonstack, sig);
712 if (act->sa_flags & SA_RESETHAND)
713 SIGADDSET(ps->ps_sigreset, sig);
714 else
715 SIGDELSET(ps->ps_sigreset, sig);
716 if (act->sa_flags & SA_NODEFER)
717 SIGADDSET(ps->ps_signodefer, sig);
718 else
719 SIGDELSET(ps->ps_signodefer, sig);
720 if (sig == SIGCHLD) {
721 if (act->sa_flags & SA_NOCLDSTOP)
722 ps->ps_flag |= PS_NOCLDSTOP;
723 else
724 ps->ps_flag &= ~PS_NOCLDSTOP;
725 if (act->sa_flags & SA_NOCLDWAIT) {
726 /*
727 * Paranoia: since SA_NOCLDWAIT is implemented
728 * by reparenting the dying child to PID 1 (and
729 * trust it to reap the zombie), PID 1 itself
730 * is forbidden to set SA_NOCLDWAIT.
731 */
732 if (p->p_pid == 1)
733 ps->ps_flag &= ~PS_NOCLDWAIT;
734 else
735 ps->ps_flag |= PS_NOCLDWAIT;
736 } else
737 ps->ps_flag &= ~PS_NOCLDWAIT;
738 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
739 ps->ps_flag |= PS_CLDSIGIGN;
740 else
741 ps->ps_flag &= ~PS_CLDSIGIGN;
742 }
743 /*
744 * Set bit in ps_sigignore for signals that are set to SIG_IGN,
745 * and for signals set to SIG_DFL where the default is to
746 * ignore. However, don't put SIGCONT in ps_sigignore, as we
747 * have to restart the process.
748 */
749 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
750 (sigprop(sig) & SA_IGNORE &&
751 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
752 /* never to be seen again */
753 sigqueue_delete_proc(p, sig);
754 if (sig != SIGCONT)
755 /* easier in psignal */
756 SIGADDSET(ps->ps_sigignore, sig);
757 SIGDELSET(ps->ps_sigcatch, sig);
758 } else {
759 SIGDELSET(ps->ps_sigignore, sig);
760 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
761 SIGDELSET(ps->ps_sigcatch, sig);
762 else
763 SIGADDSET(ps->ps_sigcatch, sig);
764 }
765 #ifdef COMPAT_FREEBSD4
766 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
767 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
768 (flags & KSA_FREEBSD4) == 0)
769 SIGDELSET(ps->ps_freebsd4, sig);
770 else
771 SIGADDSET(ps->ps_freebsd4, sig);
772 #endif
773 #ifdef COMPAT_43
774 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
775 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
776 (flags & KSA_OSIGSET) == 0)
777 SIGDELSET(ps->ps_osigset, sig);
778 else
779 SIGADDSET(ps->ps_osigset, sig);
780 #endif
781 }
782 mtx_unlock(&ps->ps_mtx);
783 PROC_UNLOCK(p);
784 return (0);
785 }
786
787 #ifndef _SYS_SYSPROTO_H_
788 struct sigaction_args {
789 int sig;
790 struct sigaction *act;
791 struct sigaction *oact;
792 };
793 #endif
794 int
795 sigaction(td, uap)
796 struct thread *td;
797 register struct sigaction_args *uap;
798 {
799 struct sigaction act, oact;
800 register struct sigaction *actp, *oactp;
801 int error;
802
803 actp = (uap->act != NULL) ? &act : NULL;
804 oactp = (uap->oact != NULL) ? &oact : NULL;
805 if (actp) {
806 error = copyin(uap->act, actp, sizeof(act));
807 if (error)
808 return (error);
809 }
810 error = kern_sigaction(td, uap->sig, actp, oactp, 0);
811 if (oactp && !error)
812 error = copyout(oactp, uap->oact, sizeof(oact));
813 return (error);
814 }
815
816 #ifdef COMPAT_FREEBSD4
817 #ifndef _SYS_SYSPROTO_H_
818 struct freebsd4_sigaction_args {
819 int sig;
820 struct sigaction *act;
821 struct sigaction *oact;
822 };
823 #endif
824 int
825 freebsd4_sigaction(td, uap)
826 struct thread *td;
827 register struct freebsd4_sigaction_args *uap;
828 {
829 struct sigaction act, oact;
830 register struct sigaction *actp, *oactp;
831 int error;
832
833
834 actp = (uap->act != NULL) ? &act : NULL;
835 oactp = (uap->oact != NULL) ? &oact : NULL;
836 if (actp) {
837 error = copyin(uap->act, actp, sizeof(act));
838 if (error)
839 return (error);
840 }
841 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4);
842 if (oactp && !error)
843 error = copyout(oactp, uap->oact, sizeof(oact));
844 return (error);
845 }
846 #endif /* COMAPT_FREEBSD4 */
847
848 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
849 #ifndef _SYS_SYSPROTO_H_
850 struct osigaction_args {
851 int signum;
852 struct osigaction *nsa;
853 struct osigaction *osa;
854 };
855 #endif
856 int
857 osigaction(td, uap)
858 struct thread *td;
859 register struct osigaction_args *uap;
860 {
861 struct osigaction sa;
862 struct sigaction nsa, osa;
863 register struct sigaction *nsap, *osap;
864 int error;
865
866 if (uap->signum <= 0 || uap->signum >= ONSIG)
867 return (EINVAL);
868
869 nsap = (uap->nsa != NULL) ? &nsa : NULL;
870 osap = (uap->osa != NULL) ? &osa : NULL;
871
872 if (nsap) {
873 error = copyin(uap->nsa, &sa, sizeof(sa));
874 if (error)
875 return (error);
876 nsap->sa_handler = sa.sa_handler;
877 nsap->sa_flags = sa.sa_flags;
878 OSIG2SIG(sa.sa_mask, nsap->sa_mask);
879 }
880 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
881 if (osap && !error) {
882 sa.sa_handler = osap->sa_handler;
883 sa.sa_flags = osap->sa_flags;
884 SIG2OSIG(osap->sa_mask, sa.sa_mask);
885 error = copyout(&sa, uap->osa, sizeof(sa));
886 }
887 return (error);
888 }
889
890 #if !defined(__i386__)
891 /* Avoid replicating the same stub everywhere */
892 int
893 osigreturn(td, uap)
894 struct thread *td;
895 struct osigreturn_args *uap;
896 {
897
898 return (nosys(td, (struct nosys_args *)uap));
899 }
900 #endif
901 #endif /* COMPAT_43 */
902
903 /*
904 * Initialize signal state for process 0;
905 * set to ignore signals that are ignored by default.
906 */
907 void
908 siginit(p)
909 struct proc *p;
910 {
911 register int i;
912 struct sigacts *ps;
913
914 PROC_LOCK(p);
915 ps = p->p_sigacts;
916 mtx_lock(&ps->ps_mtx);
917 for (i = 1; i <= NSIG; i++)
918 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
919 SIGADDSET(ps->ps_sigignore, i);
920 mtx_unlock(&ps->ps_mtx);
921 PROC_UNLOCK(p);
922 }
923
924 /*
925 * Reset signals for an exec of the specified process.
926 */
927 void
928 execsigs(struct proc *p)
929 {
930 struct sigacts *ps;
931 int sig;
932 struct thread *td;
933
934 /*
935 * Reset caught signals. Held signals remain held
936 * through td_sigmask (unless they were caught,
937 * and are now ignored by default).
938 */
939 PROC_LOCK_ASSERT(p, MA_OWNED);
940 td = FIRST_THREAD_IN_PROC(p);
941 ps = p->p_sigacts;
942 mtx_lock(&ps->ps_mtx);
943 while (SIGNOTEMPTY(ps->ps_sigcatch)) {
944 sig = sig_ffs(&ps->ps_sigcatch);
945 SIGDELSET(ps->ps_sigcatch, sig);
946 if (sigprop(sig) & SA_IGNORE) {
947 if (sig != SIGCONT)
948 SIGADDSET(ps->ps_sigignore, sig);
949 sigqueue_delete_proc(p, sig);
950 }
951 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
952 }
953 /*
954 * Reset stack state to the user stack.
955 * Clear set of signals caught on the signal stack.
956 */
957 td->td_sigstk.ss_flags = SS_DISABLE;
958 td->td_sigstk.ss_size = 0;
959 td->td_sigstk.ss_sp = 0;
960 td->td_pflags &= ~TDP_ALTSTACK;
961 /*
962 * Reset no zombies if child dies flag as Solaris does.
963 */
964 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN);
965 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
966 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL;
967 mtx_unlock(&ps->ps_mtx);
968 }
969
970 /*
971 * kern_sigprocmask()
972 *
973 * Manipulate signal mask.
974 */
975 int
976 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset,
977 int flags)
978 {
979 sigset_t new_block, oset1;
980 struct proc *p;
981 int error;
982
983 p = td->td_proc;
984 if (!(flags & SIGPROCMASK_PROC_LOCKED))
985 PROC_LOCK(p);
986 if (oset != NULL)
987 *oset = td->td_sigmask;
988
989 error = 0;
990 SIGEMPTYSET(new_block);
991 if (set != NULL) {
992 switch (how) {
993 case SIG_BLOCK:
994 SIG_CANTMASK(*set);
995 oset1 = td->td_sigmask;
996 SIGSETOR(td->td_sigmask, *set);
997 new_block = td->td_sigmask;
998 SIGSETNAND(new_block, oset1);
999 break;
1000 case SIG_UNBLOCK:
1001 SIGSETNAND(td->td_sigmask, *set);
1002 signotify(td);
1003 break;
1004 case SIG_SETMASK:
1005 SIG_CANTMASK(*set);
1006 oset1 = td->td_sigmask;
1007 if (flags & SIGPROCMASK_OLD)
1008 SIGSETLO(td->td_sigmask, *set);
1009 else
1010 td->td_sigmask = *set;
1011 new_block = td->td_sigmask;
1012 SIGSETNAND(new_block, oset1);
1013 signotify(td);
1014 break;
1015 default:
1016 error = EINVAL;
1017 break;
1018 }
1019 }
1020
1021 /*
1022 * The new_block set contains signals that were not previously
1023 * blocked, but are blocked now.
1024 *
1025 * In case we block any signal that was not previously blocked
1026 * for td, and process has the signal pending, try to schedule
1027 * signal delivery to some thread that does not block the signal,
1028 * possibly waking it up.
1029 */
1030 if (p->p_numthreads != 1)
1031 reschedule_signals(p, new_block, flags);
1032
1033 if (!(flags & SIGPROCMASK_PROC_LOCKED))
1034 PROC_UNLOCK(p);
1035 return (error);
1036 }
1037
1038 #ifndef _SYS_SYSPROTO_H_
1039 struct sigprocmask_args {
1040 int how;
1041 const sigset_t *set;
1042 sigset_t *oset;
1043 };
1044 #endif
1045 int
1046 sigprocmask(td, uap)
1047 register struct thread *td;
1048 struct sigprocmask_args *uap;
1049 {
1050 sigset_t set, oset;
1051 sigset_t *setp, *osetp;
1052 int error;
1053
1054 setp = (uap->set != NULL) ? &set : NULL;
1055 osetp = (uap->oset != NULL) ? &oset : NULL;
1056 if (setp) {
1057 error = copyin(uap->set, setp, sizeof(set));
1058 if (error)
1059 return (error);
1060 }
1061 error = kern_sigprocmask(td, uap->how, setp, osetp, 0);
1062 if (osetp && !error) {
1063 error = copyout(osetp, uap->oset, sizeof(oset));
1064 }
1065 return (error);
1066 }
1067
1068 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1069 #ifndef _SYS_SYSPROTO_H_
1070 struct osigprocmask_args {
1071 int how;
1072 osigset_t mask;
1073 };
1074 #endif
1075 int
1076 osigprocmask(td, uap)
1077 register struct thread *td;
1078 struct osigprocmask_args *uap;
1079 {
1080 sigset_t set, oset;
1081 int error;
1082
1083 OSIG2SIG(uap->mask, set);
1084 error = kern_sigprocmask(td, uap->how, &set, &oset, 1);
1085 SIG2OSIG(oset, td->td_retval[0]);
1086 return (error);
1087 }
1088 #endif /* COMPAT_43 */
1089
1090 int
1091 sigwait(struct thread *td, struct sigwait_args *uap)
1092 {
1093 ksiginfo_t ksi;
1094 sigset_t set;
1095 int error;
1096
1097 error = copyin(uap->set, &set, sizeof(set));
1098 if (error) {
1099 td->td_retval[0] = error;
1100 return (0);
1101 }
1102
1103 error = kern_sigtimedwait(td, set, &ksi, NULL);
1104 if (error) {
1105 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT)
1106 error = ERESTART;
1107 if (error == ERESTART)
1108 return (error);
1109 td->td_retval[0] = error;
1110 return (0);
1111 }
1112
1113 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo));
1114 td->td_retval[0] = error;
1115 return (0);
1116 }
1117
1118 int
1119 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap)
1120 {
1121 struct timespec ts;
1122 struct timespec *timeout;
1123 sigset_t set;
1124 ksiginfo_t ksi;
1125 int error;
1126
1127 if (uap->timeout) {
1128 error = copyin(uap->timeout, &ts, sizeof(ts));
1129 if (error)
1130 return (error);
1131
1132 timeout = &ts;
1133 } else
1134 timeout = NULL;
1135
1136 error = copyin(uap->set, &set, sizeof(set));
1137 if (error)
1138 return (error);
1139
1140 error = kern_sigtimedwait(td, set, &ksi, timeout);
1141 if (error)
1142 return (error);
1143
1144 if (uap->info)
1145 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t));
1146
1147 if (error == 0)
1148 td->td_retval[0] = ksi.ksi_signo;
1149 return (error);
1150 }
1151
1152 int
1153 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap)
1154 {
1155 ksiginfo_t ksi;
1156 sigset_t set;
1157 int error;
1158
1159 error = copyin(uap->set, &set, sizeof(set));
1160 if (error)
1161 return (error);
1162
1163 error = kern_sigtimedwait(td, set, &ksi, NULL);
1164 if (error)
1165 return (error);
1166
1167 if (uap->info)
1168 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t));
1169
1170 if (error == 0)
1171 td->td_retval[0] = ksi.ksi_signo;
1172 return (error);
1173 }
1174
1175 int
1176 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi,
1177 struct timespec *timeout)
1178 {
1179 struct sigacts *ps;
1180 sigset_t savedmask;
1181 struct proc *p;
1182 int error, sig, hz, i, timevalid = 0;
1183 struct timespec rts, ets, ts;
1184 struct timeval tv;
1185
1186 p = td->td_proc;
1187 error = 0;
1188 sig = 0;
1189 ets.tv_sec = 0;
1190 ets.tv_nsec = 0;
1191 SIG_CANTMASK(waitset);
1192
1193 PROC_LOCK(p);
1194 ps = p->p_sigacts;
1195 savedmask = td->td_sigmask;
1196 if (timeout) {
1197 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) {
1198 timevalid = 1;
1199 getnanouptime(&rts);
1200 ets = rts;
1201 timespecadd(&ets, timeout);
1202 }
1203 }
1204
1205 restart:
1206 for (i = 1; i <= _SIG_MAXSIG; ++i) {
1207 if (!SIGISMEMBER(waitset, i))
1208 continue;
1209 if (!SIGISMEMBER(td->td_sigqueue.sq_signals, i)) {
1210 if (SIGISMEMBER(p->p_sigqueue.sq_signals, i)) {
1211 sigqueue_move(&p->p_sigqueue,
1212 &td->td_sigqueue, i);
1213 } else
1214 continue;
1215 }
1216
1217 SIGFILLSET(td->td_sigmask);
1218 SIG_CANTMASK(td->td_sigmask);
1219 SIGDELSET(td->td_sigmask, i);
1220 mtx_lock(&ps->ps_mtx);
1221 sig = cursig(td, SIG_STOP_ALLOWED);
1222 mtx_unlock(&ps->ps_mtx);
1223 if (sig)
1224 goto out;
1225 else {
1226 /*
1227 * Because cursig() may have stopped current thread,
1228 * after it is resumed, things may have already been
1229 * changed, it should rescan any pending signals.
1230 */
1231 goto restart;
1232 }
1233 }
1234
1235 if (error)
1236 goto out;
1237
1238 /*
1239 * POSIX says this must be checked after looking for pending
1240 * signals.
1241 */
1242 if (timeout) {
1243 if (!timevalid) {
1244 error = EINVAL;
1245 goto out;
1246 }
1247 getnanouptime(&rts);
1248 if (timespeccmp(&rts, &ets, >=)) {
1249 error = EAGAIN;
1250 goto out;
1251 }
1252 ts = ets;
1253 timespecsub(&ts, &rts);
1254 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1255 hz = tvtohz(&tv);
1256 } else
1257 hz = 0;
1258
1259 td->td_sigmask = savedmask;
1260 SIGSETNAND(td->td_sigmask, waitset);
1261 signotify(td);
1262 error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz);
1263 if (timeout) {
1264 if (error == ERESTART) {
1265 /* timeout can not be restarted. */
1266 error = EINTR;
1267 } else if (error == EAGAIN) {
1268 /* will calculate timeout by ourself. */
1269 error = 0;
1270 }
1271 }
1272 goto restart;
1273
1274 out:
1275 td->td_sigmask = savedmask;
1276 signotify(td);
1277 if (sig) {
1278 ksiginfo_init(ksi);
1279 sigqueue_get(&td->td_sigqueue, sig, ksi);
1280 ksi->ksi_signo = sig;
1281
1282 SDT_PROBE(proc, kernel, , signal_clear, sig, ksi, 0, 0, 0);
1283
1284 if (ksi->ksi_code == SI_TIMER)
1285 itimer_accept(p, ksi->ksi_timerid, ksi);
1286 error = 0;
1287
1288 #ifdef KTRACE
1289 if (KTRPOINT(td, KTR_PSIG)) {
1290 sig_t action;
1291
1292 mtx_lock(&ps->ps_mtx);
1293 action = ps->ps_sigact[_SIG_IDX(sig)];
1294 mtx_unlock(&ps->ps_mtx);
1295 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code);
1296 }
1297 #endif
1298 if (sig == SIGKILL)
1299 sigexit(td, sig);
1300 }
1301 PROC_UNLOCK(p);
1302 return (error);
1303 }
1304
1305 #ifndef _SYS_SYSPROTO_H_
1306 struct sigpending_args {
1307 sigset_t *set;
1308 };
1309 #endif
1310 int
1311 sigpending(td, uap)
1312 struct thread *td;
1313 struct sigpending_args *uap;
1314 {
1315 struct proc *p = td->td_proc;
1316 sigset_t pending;
1317
1318 PROC_LOCK(p);
1319 pending = p->p_sigqueue.sq_signals;
1320 SIGSETOR(pending, td->td_sigqueue.sq_signals);
1321 PROC_UNLOCK(p);
1322 return (copyout(&pending, uap->set, sizeof(sigset_t)));
1323 }
1324
1325 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1326 #ifndef _SYS_SYSPROTO_H_
1327 struct osigpending_args {
1328 int dummy;
1329 };
1330 #endif
1331 int
1332 osigpending(td, uap)
1333 struct thread *td;
1334 struct osigpending_args *uap;
1335 {
1336 struct proc *p = td->td_proc;
1337 sigset_t pending;
1338
1339 PROC_LOCK(p);
1340 pending = p->p_sigqueue.sq_signals;
1341 SIGSETOR(pending, td->td_sigqueue.sq_signals);
1342 PROC_UNLOCK(p);
1343 SIG2OSIG(pending, td->td_retval[0]);
1344 return (0);
1345 }
1346 #endif /* COMPAT_43 */
1347
1348 #if defined(COMPAT_43)
1349 /*
1350 * Generalized interface signal handler, 4.3-compatible.
1351 */
1352 #ifndef _SYS_SYSPROTO_H_
1353 struct osigvec_args {
1354 int signum;
1355 struct sigvec *nsv;
1356 struct sigvec *osv;
1357 };
1358 #endif
1359 /* ARGSUSED */
1360 int
1361 osigvec(td, uap)
1362 struct thread *td;
1363 register struct osigvec_args *uap;
1364 {
1365 struct sigvec vec;
1366 struct sigaction nsa, osa;
1367 register struct sigaction *nsap, *osap;
1368 int error;
1369
1370 if (uap->signum <= 0 || uap->signum >= ONSIG)
1371 return (EINVAL);
1372 nsap = (uap->nsv != NULL) ? &nsa : NULL;
1373 osap = (uap->osv != NULL) ? &osa : NULL;
1374 if (nsap) {
1375 error = copyin(uap->nsv, &vec, sizeof(vec));
1376 if (error)
1377 return (error);
1378 nsap->sa_handler = vec.sv_handler;
1379 OSIG2SIG(vec.sv_mask, nsap->sa_mask);
1380 nsap->sa_flags = vec.sv_flags;
1381 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */
1382 }
1383 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
1384 if (osap && !error) {
1385 vec.sv_handler = osap->sa_handler;
1386 SIG2OSIG(osap->sa_mask, vec.sv_mask);
1387 vec.sv_flags = osap->sa_flags;
1388 vec.sv_flags &= ~SA_NOCLDWAIT;
1389 vec.sv_flags ^= SA_RESTART;
1390 error = copyout(&vec, uap->osv, sizeof(vec));
1391 }
1392 return (error);
1393 }
1394
1395 #ifndef _SYS_SYSPROTO_H_
1396 struct osigblock_args {
1397 int mask;
1398 };
1399 #endif
1400 int
1401 osigblock(td, uap)
1402 register struct thread *td;
1403 struct osigblock_args *uap;
1404 {
1405 sigset_t set, oset;
1406
1407 OSIG2SIG(uap->mask, set);
1408 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0);
1409 SIG2OSIG(oset, td->td_retval[0]);
1410 return (0);
1411 }
1412
1413 #ifndef _SYS_SYSPROTO_H_
1414 struct osigsetmask_args {
1415 int mask;
1416 };
1417 #endif
1418 int
1419 osigsetmask(td, uap)
1420 struct thread *td;
1421 struct osigsetmask_args *uap;
1422 {
1423 sigset_t set, oset;
1424
1425 OSIG2SIG(uap->mask, set);
1426 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0);
1427 SIG2OSIG(oset, td->td_retval[0]);
1428 return (0);
1429 }
1430 #endif /* COMPAT_43 */
1431
1432 /*
1433 * Suspend calling thread until signal, providing mask to be set in the
1434 * meantime.
1435 */
1436 #ifndef _SYS_SYSPROTO_H_
1437 struct sigsuspend_args {
1438 const sigset_t *sigmask;
1439 };
1440 #endif
1441 /* ARGSUSED */
1442 int
1443 sigsuspend(td, uap)
1444 struct thread *td;
1445 struct sigsuspend_args *uap;
1446 {
1447 sigset_t mask;
1448 int error;
1449
1450 error = copyin(uap->sigmask, &mask, sizeof(mask));
1451 if (error)
1452 return (error);
1453 return (kern_sigsuspend(td, mask));
1454 }
1455
1456 int
1457 kern_sigsuspend(struct thread *td, sigset_t mask)
1458 {
1459 struct proc *p = td->td_proc;
1460 int has_sig, sig;
1461
1462 /*
1463 * When returning from sigsuspend, we want
1464 * the old mask to be restored after the
1465 * signal handler has finished. Thus, we
1466 * save it here and mark the sigacts structure
1467 * to indicate this.
1468 */
1469 PROC_LOCK(p);
1470 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask,
1471 SIGPROCMASK_PROC_LOCKED);
1472 td->td_pflags |= TDP_OLDMASK;
1473
1474 /*
1475 * Process signals now. Otherwise, we can get spurious wakeup
1476 * due to signal entered process queue, but delivered to other
1477 * thread. But sigsuspend should return only on signal
1478 * delivery.
1479 */
1480 (p->p_sysent->sv_set_syscall_retval)(td, EINTR);
1481 for (has_sig = 0; !has_sig;) {
1482 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause",
1483 0) == 0)
1484 /* void */;
1485 thread_suspend_check(0);
1486 mtx_lock(&p->p_sigacts->ps_mtx);
1487 while ((sig = cursig(td, SIG_STOP_ALLOWED)) != 0)
1488 has_sig += postsig(sig);
1489 mtx_unlock(&p->p_sigacts->ps_mtx);
1490 }
1491 PROC_UNLOCK(p);
1492 td->td_errno = EINTR;
1493 td->td_pflags |= TDP_NERRNO;
1494 return (EJUSTRETURN);
1495 }
1496
1497 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1498 /*
1499 * Compatibility sigsuspend call for old binaries. Note nonstandard calling
1500 * convention: libc stub passes mask, not pointer, to save a copyin.
1501 */
1502 #ifndef _SYS_SYSPROTO_H_
1503 struct osigsuspend_args {
1504 osigset_t mask;
1505 };
1506 #endif
1507 /* ARGSUSED */
1508 int
1509 osigsuspend(td, uap)
1510 struct thread *td;
1511 struct osigsuspend_args *uap;
1512 {
1513 sigset_t mask;
1514
1515 OSIG2SIG(uap->mask, mask);
1516 return (kern_sigsuspend(td, mask));
1517 }
1518 #endif /* COMPAT_43 */
1519
1520 #if defined(COMPAT_43)
1521 #ifndef _SYS_SYSPROTO_H_
1522 struct osigstack_args {
1523 struct sigstack *nss;
1524 struct sigstack *oss;
1525 };
1526 #endif
1527 /* ARGSUSED */
1528 int
1529 osigstack(td, uap)
1530 struct thread *td;
1531 register struct osigstack_args *uap;
1532 {
1533 struct sigstack nss, oss;
1534 int error = 0;
1535
1536 if (uap->nss != NULL) {
1537 error = copyin(uap->nss, &nss, sizeof(nss));
1538 if (error)
1539 return (error);
1540 }
1541 oss.ss_sp = td->td_sigstk.ss_sp;
1542 oss.ss_onstack = sigonstack(cpu_getstack(td));
1543 if (uap->nss != NULL) {
1544 td->td_sigstk.ss_sp = nss.ss_sp;
1545 td->td_sigstk.ss_size = 0;
1546 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK;
1547 td->td_pflags |= TDP_ALTSTACK;
1548 }
1549 if (uap->oss != NULL)
1550 error = copyout(&oss, uap->oss, sizeof(oss));
1551
1552 return (error);
1553 }
1554 #endif /* COMPAT_43 */
1555
1556 #ifndef _SYS_SYSPROTO_H_
1557 struct sigaltstack_args {
1558 stack_t *ss;
1559 stack_t *oss;
1560 };
1561 #endif
1562 /* ARGSUSED */
1563 int
1564 sigaltstack(td, uap)
1565 struct thread *td;
1566 register struct sigaltstack_args *uap;
1567 {
1568 stack_t ss, oss;
1569 int error;
1570
1571 if (uap->ss != NULL) {
1572 error = copyin(uap->ss, &ss, sizeof(ss));
1573 if (error)
1574 return (error);
1575 }
1576 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL,
1577 (uap->oss != NULL) ? &oss : NULL);
1578 if (error)
1579 return (error);
1580 if (uap->oss != NULL)
1581 error = copyout(&oss, uap->oss, sizeof(stack_t));
1582 return (error);
1583 }
1584
1585 int
1586 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss)
1587 {
1588 struct proc *p = td->td_proc;
1589 int oonstack;
1590
1591 oonstack = sigonstack(cpu_getstack(td));
1592
1593 if (oss != NULL) {
1594 *oss = td->td_sigstk;
1595 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK)
1596 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
1597 }
1598
1599 if (ss != NULL) {
1600 if (oonstack)
1601 return (EPERM);
1602 if ((ss->ss_flags & ~SS_DISABLE) != 0)
1603 return (EINVAL);
1604 if (!(ss->ss_flags & SS_DISABLE)) {
1605 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
1606 return (ENOMEM);
1607
1608 td->td_sigstk = *ss;
1609 td->td_pflags |= TDP_ALTSTACK;
1610 } else {
1611 td->td_pflags &= ~TDP_ALTSTACK;
1612 }
1613 }
1614 return (0);
1615 }
1616
1617 /*
1618 * Common code for kill process group/broadcast kill.
1619 * cp is calling process.
1620 */
1621 static int
1622 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi)
1623 {
1624 struct proc *p;
1625 struct pgrp *pgrp;
1626 int err;
1627 int ret;
1628
1629 ret = ESRCH;
1630 if (all) {
1631 /*
1632 * broadcast
1633 */
1634 sx_slock(&allproc_lock);
1635 FOREACH_PROC_IN_SYSTEM(p) {
1636 PROC_LOCK(p);
1637 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
1638 p == td->td_proc || p->p_state == PRS_NEW) {
1639 PROC_UNLOCK(p);
1640 continue;
1641 }
1642 err = p_cansignal(td, p, sig);
1643 if (err == 0) {
1644 if (sig)
1645 pksignal(p, sig, ksi);
1646 ret = err;
1647 }
1648 else if (ret == ESRCH)
1649 ret = err;
1650 PROC_UNLOCK(p);
1651 }
1652 sx_sunlock(&allproc_lock);
1653 } else {
1654 sx_slock(&proctree_lock);
1655 if (pgid == 0) {
1656 /*
1657 * zero pgid means send to my process group.
1658 */
1659 pgrp = td->td_proc->p_pgrp;
1660 PGRP_LOCK(pgrp);
1661 } else {
1662 pgrp = pgfind(pgid);
1663 if (pgrp == NULL) {
1664 sx_sunlock(&proctree_lock);
1665 return (ESRCH);
1666 }
1667 }
1668 sx_sunlock(&proctree_lock);
1669 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
1670 PROC_LOCK(p);
1671 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
1672 p->p_state == PRS_NEW ) {
1673 PROC_UNLOCK(p);
1674 continue;
1675 }
1676 err = p_cansignal(td, p, sig);
1677 if (err == 0) {
1678 if (sig)
1679 pksignal(p, sig, ksi);
1680 ret = err;
1681 }
1682 else if (ret == ESRCH)
1683 ret = err;
1684 PROC_UNLOCK(p);
1685 }
1686 PGRP_UNLOCK(pgrp);
1687 }
1688 return (ret);
1689 }
1690
1691 #ifndef _SYS_SYSPROTO_H_
1692 struct kill_args {
1693 int pid;
1694 int signum;
1695 };
1696 #endif
1697 /* ARGSUSED */
1698 int
1699 kill(struct thread *td, struct kill_args *uap)
1700 {
1701 ksiginfo_t ksi;
1702 struct proc *p;
1703 int error;
1704
1705 AUDIT_ARG_SIGNUM(uap->signum);
1706 AUDIT_ARG_PID(uap->pid);
1707 if ((u_int)uap->signum > _SIG_MAXSIG)
1708 return (EINVAL);
1709
1710 ksiginfo_init(&ksi);
1711 ksi.ksi_signo = uap->signum;
1712 ksi.ksi_code = SI_USER;
1713 ksi.ksi_pid = td->td_proc->p_pid;
1714 ksi.ksi_uid = td->td_ucred->cr_ruid;
1715
1716 if (uap->pid > 0) {
1717 /* kill single process */
1718 if ((p = pfind(uap->pid)) == NULL) {
1719 if ((p = zpfind(uap->pid)) == NULL)
1720 return (ESRCH);
1721 }
1722 AUDIT_ARG_PROCESS(p);
1723 error = p_cansignal(td, p, uap->signum);
1724 if (error == 0 && uap->signum)
1725 pksignal(p, uap->signum, &ksi);
1726 PROC_UNLOCK(p);
1727 return (error);
1728 }
1729 switch (uap->pid) {
1730 case -1: /* broadcast signal */
1731 return (killpg1(td, uap->signum, 0, 1, &ksi));
1732 case 0: /* signal own process group */
1733 return (killpg1(td, uap->signum, 0, 0, &ksi));
1734 default: /* negative explicit process group */
1735 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi));
1736 }
1737 /* NOTREACHED */
1738 }
1739
1740 #if defined(COMPAT_43)
1741 #ifndef _SYS_SYSPROTO_H_
1742 struct okillpg_args {
1743 int pgid;
1744 int signum;
1745 };
1746 #endif
1747 /* ARGSUSED */
1748 int
1749 okillpg(struct thread *td, struct okillpg_args *uap)
1750 {
1751 ksiginfo_t ksi;
1752
1753 AUDIT_ARG_SIGNUM(uap->signum);
1754 AUDIT_ARG_PID(uap->pgid);
1755 if ((u_int)uap->signum > _SIG_MAXSIG)
1756 return (EINVAL);
1757
1758 ksiginfo_init(&ksi);
1759 ksi.ksi_signo = uap->signum;
1760 ksi.ksi_code = SI_USER;
1761 ksi.ksi_pid = td->td_proc->p_pid;
1762 ksi.ksi_uid = td->td_ucred->cr_ruid;
1763 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi));
1764 }
1765 #endif /* COMPAT_43 */
1766
1767 #ifndef _SYS_SYSPROTO_H_
1768 struct sigqueue_args {
1769 pid_t pid;
1770 int signum;
1771 /* union sigval */ void *value;
1772 };
1773 #endif
1774 int
1775 sigqueue(struct thread *td, struct sigqueue_args *uap)
1776 {
1777 ksiginfo_t ksi;
1778 struct proc *p;
1779 int error;
1780
1781 if ((u_int)uap->signum > _SIG_MAXSIG)
1782 return (EINVAL);
1783
1784 /*
1785 * Specification says sigqueue can only send signal to
1786 * single process.
1787 */
1788 if (uap->pid <= 0)
1789 return (EINVAL);
1790
1791 if ((p = pfind(uap->pid)) == NULL) {
1792 if ((p = zpfind(uap->pid)) == NULL)
1793 return (ESRCH);
1794 }
1795 error = p_cansignal(td, p, uap->signum);
1796 if (error == 0 && uap->signum != 0) {
1797 ksiginfo_init(&ksi);
1798 ksi.ksi_flags = KSI_SIGQ;
1799 ksi.ksi_signo = uap->signum;
1800 ksi.ksi_code = SI_QUEUE;
1801 ksi.ksi_pid = td->td_proc->p_pid;
1802 ksi.ksi_uid = td->td_ucred->cr_ruid;
1803 ksi.ksi_value.sival_ptr = uap->value;
1804 error = tdsignal(p, NULL, ksi.ksi_signo, &ksi);
1805 }
1806 PROC_UNLOCK(p);
1807 return (error);
1808 }
1809
1810 /*
1811 * Send a signal to a process group.
1812 */
1813 void
1814 gsignal(int pgid, int sig, ksiginfo_t *ksi)
1815 {
1816 struct pgrp *pgrp;
1817
1818 if (pgid != 0) {
1819 sx_slock(&proctree_lock);
1820 pgrp = pgfind(pgid);
1821 sx_sunlock(&proctree_lock);
1822 if (pgrp != NULL) {
1823 pgsignal(pgrp, sig, 0, ksi);
1824 PGRP_UNLOCK(pgrp);
1825 }
1826 }
1827 }
1828
1829 /*
1830 * Send a signal to a process group. If checktty is 1,
1831 * limit to members which have a controlling terminal.
1832 */
1833 void
1834 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi)
1835 {
1836 struct proc *p;
1837
1838 if (pgrp) {
1839 PGRP_LOCK_ASSERT(pgrp, MA_OWNED);
1840 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
1841 PROC_LOCK(p);
1842 if (p->p_state == PRS_NORMAL &&
1843 (checkctty == 0 || p->p_flag & P_CONTROLT))
1844 pksignal(p, sig, ksi);
1845 PROC_UNLOCK(p);
1846 }
1847 }
1848 }
1849
1850 /*
1851 * Send a signal caused by a trap to the current thread. If it will be
1852 * caught immediately, deliver it with correct code. Otherwise, post it
1853 * normally.
1854 */
1855 void
1856 trapsignal(struct thread *td, ksiginfo_t *ksi)
1857 {
1858 struct sigacts *ps;
1859 sigset_t mask;
1860 struct proc *p;
1861 int sig;
1862 int code;
1863
1864 p = td->td_proc;
1865 sig = ksi->ksi_signo;
1866 code = ksi->ksi_code;
1867 KASSERT(_SIG_VALID(sig), ("invalid signal"));
1868
1869 PROC_LOCK(p);
1870 ps = p->p_sigacts;
1871 mtx_lock(&ps->ps_mtx);
1872 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) &&
1873 !SIGISMEMBER(td->td_sigmask, sig)) {
1874 td->td_ru.ru_nsignals++;
1875 #ifdef KTRACE
1876 if (KTRPOINT(curthread, KTR_PSIG))
1877 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)],
1878 &td->td_sigmask, code);
1879 #endif
1880 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)],
1881 ksi, &td->td_sigmask);
1882 mask = ps->ps_catchmask[_SIG_IDX(sig)];
1883 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1884 SIGADDSET(mask, sig);
1885 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL,
1886 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED);
1887 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
1888 /*
1889 * See kern_sigaction() for origin of this code.
1890 */
1891 SIGDELSET(ps->ps_sigcatch, sig);
1892 if (sig != SIGCONT &&
1893 sigprop(sig) & SA_IGNORE)
1894 SIGADDSET(ps->ps_sigignore, sig);
1895 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1896 }
1897 mtx_unlock(&ps->ps_mtx);
1898 } else {
1899 /*
1900 * Avoid a possible infinite loop if the thread
1901 * masking the signal or process is ignoring the
1902 * signal.
1903 */
1904 if (kern_forcesigexit &&
1905 (SIGISMEMBER(td->td_sigmask, sig) ||
1906 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) {
1907 SIGDELSET(td->td_sigmask, sig);
1908 SIGDELSET(ps->ps_sigcatch, sig);
1909 SIGDELSET(ps->ps_sigignore, sig);
1910 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1911 }
1912 mtx_unlock(&ps->ps_mtx);
1913 p->p_code = code; /* XXX for core dump/debugger */
1914 p->p_sig = sig; /* XXX to verify code */
1915 tdsignal(p, td, sig, ksi);
1916 }
1917 PROC_UNLOCK(p);
1918 }
1919
1920 static struct thread *
1921 sigtd(struct proc *p, int sig, int prop)
1922 {
1923 struct thread *td, *signal_td;
1924
1925 PROC_LOCK_ASSERT(p, MA_OWNED);
1926
1927 /*
1928 * Check if current thread can handle the signal without
1929 * switching context to another thread.
1930 */
1931 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig))
1932 return (curthread);
1933 signal_td = NULL;
1934 FOREACH_THREAD_IN_PROC(p, td) {
1935 if (!SIGISMEMBER(td->td_sigmask, sig)) {
1936 signal_td = td;
1937 break;
1938 }
1939 }
1940 if (signal_td == NULL)
1941 signal_td = FIRST_THREAD_IN_PROC(p);
1942 return (signal_td);
1943 }
1944
1945 /*
1946 * Send the signal to the process. If the signal has an action, the action
1947 * is usually performed by the target process rather than the caller; we add
1948 * the signal to the set of pending signals for the process.
1949 *
1950 * Exceptions:
1951 * o When a stop signal is sent to a sleeping process that takes the
1952 * default action, the process is stopped without awakening it.
1953 * o SIGCONT restarts stopped processes (or puts them back to sleep)
1954 * regardless of the signal action (eg, blocked or ignored).
1955 *
1956 * Other ignored signals are discarded immediately.
1957 *
1958 * NB: This function may be entered from the debugger via the "kill" DDB
1959 * command. There is little that can be done to mitigate the possibly messy
1960 * side effects of this unwise possibility.
1961 */
1962 void
1963 psignal(struct proc *p, int sig)
1964 {
1965 ksiginfo_t ksi;
1966
1967 ksiginfo_init(&ksi);
1968 ksi.ksi_signo = sig;
1969 ksi.ksi_code = SI_KERNEL;
1970 (void) tdsignal(p, NULL, sig, &ksi);
1971 }
1972
1973 void
1974 pksignal(struct proc *p, int sig, ksiginfo_t *ksi)
1975 {
1976
1977 (void) tdsignal(p, NULL, sig, ksi);
1978 }
1979
1980 int
1981 psignal_event(struct proc *p, struct sigevent *sigev, ksiginfo_t *ksi)
1982 {
1983 struct thread *td = NULL;
1984
1985 PROC_LOCK_ASSERT(p, MA_OWNED);
1986
1987 KASSERT(!KSI_ONQ(ksi), ("psignal_event: ksi on queue"));
1988
1989 /*
1990 * ksi_code and other fields should be set before
1991 * calling this function.
1992 */
1993 ksi->ksi_signo = sigev->sigev_signo;
1994 ksi->ksi_value = sigev->sigev_value;
1995 if (sigev->sigev_notify == SIGEV_THREAD_ID) {
1996 td = thread_find(p, sigev->sigev_notify_thread_id);
1997 if (td == NULL)
1998 return (ESRCH);
1999 }
2000 return (tdsignal(p, td, ksi->ksi_signo, ksi));
2001 }
2002
2003 void
2004 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi)
2005 {
2006 ksiginfo_t ksi_thunk;
2007
2008 /*
2009 * If ksi is NULL, use ksi_thunk and provide semantics
2010 * identical to tdsignal() in 9.0+.
2011 */
2012 if (ksi == NULL) {
2013 ksi = &ksi_thunk;
2014 ksiginfo_init(ksi);
2015 ksi->ksi_signo = sig;
2016 ksi->ksi_code = SI_KERNEL;
2017 }
2018 (void) tdsignal(td->td_proc, td, sig, ksi);
2019 }
2020
2021 int
2022 tdsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi)
2023 {
2024 sig_t action;
2025 sigqueue_t *sigqueue;
2026 int prop;
2027 struct sigacts *ps;
2028 int intrval;
2029 int ret = 0;
2030 int wakeup_swapper;
2031
2032 PROC_LOCK_ASSERT(p, MA_OWNED);
2033
2034 if (!_SIG_VALID(sig))
2035 panic("tdsignal(): invalid signal %d", sig);
2036
2037 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("tdsignal: ksi on queue"));
2038
2039 /*
2040 * IEEE Std 1003.1-2001: return success when killing a zombie.
2041 */
2042 if (p->p_state == PRS_ZOMBIE) {
2043 if (ksi && (ksi->ksi_flags & KSI_INS))
2044 ksiginfo_tryfree(ksi);
2045 return (ret);
2046 }
2047
2048 ps = p->p_sigacts;
2049 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig);
2050 prop = sigprop(sig);
2051
2052 if (td == NULL) {
2053 td = sigtd(p, sig, prop);
2054 sigqueue = &p->p_sigqueue;
2055 } else {
2056 KASSERT(td->td_proc == p, ("invalid thread"));
2057 sigqueue = &td->td_sigqueue;
2058 }
2059
2060 SDT_PROBE(proc, kernel, , signal_send, td, p, sig, 0, 0 );
2061
2062 /*
2063 * If the signal is being ignored,
2064 * then we forget about it immediately.
2065 * (Note: we don't set SIGCONT in ps_sigignore,
2066 * and if it is set to SIG_IGN,
2067 * action will be SIG_DFL here.)
2068 */
2069 mtx_lock(&ps->ps_mtx);
2070 if (SIGISMEMBER(ps->ps_sigignore, sig)) {
2071 SDT_PROBE(proc, kernel, , signal_discard, td, p, sig, 0, 0 );
2072
2073 mtx_unlock(&ps->ps_mtx);
2074 if (ksi && (ksi->ksi_flags & KSI_INS))
2075 ksiginfo_tryfree(ksi);
2076 return (ret);
2077 }
2078 if (SIGISMEMBER(td->td_sigmask, sig))
2079 action = SIG_HOLD;
2080 else if (SIGISMEMBER(ps->ps_sigcatch, sig))
2081 action = SIG_CATCH;
2082 else
2083 action = SIG_DFL;
2084 if (SIGISMEMBER(ps->ps_sigintr, sig))
2085 intrval = EINTR;
2086 else
2087 intrval = ERESTART;
2088 mtx_unlock(&ps->ps_mtx);
2089
2090 if (prop & SA_CONT)
2091 sigqueue_delete_stopmask_proc(p);
2092 else if (prop & SA_STOP) {
2093 /*
2094 * If sending a tty stop signal to a member of an orphaned
2095 * process group, discard the signal here if the action
2096 * is default; don't stop the process below if sleeping,
2097 * and don't clear any pending SIGCONT.
2098 */
2099 if ((prop & SA_TTYSTOP) &&
2100 (p->p_pgrp->pg_jobc == 0) &&
2101 (action == SIG_DFL)) {
2102 if (ksi && (ksi->ksi_flags & KSI_INS))
2103 ksiginfo_tryfree(ksi);
2104 return (ret);
2105 }
2106 sigqueue_delete_proc(p, SIGCONT);
2107 if (p->p_flag & P_CONTINUED) {
2108 p->p_flag &= ~P_CONTINUED;
2109 PROC_LOCK(p->p_pptr);
2110 sigqueue_take(p->p_ksi);
2111 PROC_UNLOCK(p->p_pptr);
2112 }
2113 }
2114
2115 ret = sigqueue_add(sigqueue, sig, ksi);
2116 if (ret != 0)
2117 return (ret);
2118 signotify(td);
2119 /*
2120 * Defer further processing for signals which are held,
2121 * except that stopped processes must be continued by SIGCONT.
2122 */
2123 if (action == SIG_HOLD &&
2124 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG)))
2125 return (ret);
2126 /*
2127 * SIGKILL: Remove procfs STOPEVENTs.
2128 */
2129 if (sig == SIGKILL) {
2130 /* from procfs_ioctl.c: PIOCBIC */
2131 p->p_stops = 0;
2132 /* from procfs_ioctl.c: PIOCCONT */
2133 p->p_step = 0;
2134 wakeup(&p->p_step);
2135 }
2136 /*
2137 * Some signals have a process-wide effect and a per-thread
2138 * component. Most processing occurs when the process next
2139 * tries to cross the user boundary, however there are some
2140 * times when processing needs to be done immediatly, such as
2141 * waking up threads so that they can cross the user boundary.
2142 * We try do the per-process part here.
2143 */
2144 if (P_SHOULDSTOP(p)) {
2145 KASSERT(!(p->p_flag & P_WEXIT),
2146 ("signal to stopped but exiting process"));
2147 if (sig == SIGKILL) {
2148 /*
2149 * If traced process is already stopped,
2150 * then no further action is necessary.
2151 */
2152 if (p->p_flag & P_TRACED)
2153 goto out;
2154 /*
2155 * SIGKILL sets process running.
2156 * It will die elsewhere.
2157 * All threads must be restarted.
2158 */
2159 p->p_flag &= ~P_STOPPED_SIG;
2160 goto runfast;
2161 }
2162
2163 if (prop & SA_CONT) {
2164 /*
2165 * If traced process is already stopped,
2166 * then no further action is necessary.
2167 */
2168 if (p->p_flag & P_TRACED)
2169 goto out;
2170 /*
2171 * If SIGCONT is default (or ignored), we continue the
2172 * process but don't leave the signal in sigqueue as
2173 * it has no further action. If SIGCONT is held, we
2174 * continue the process and leave the signal in
2175 * sigqueue. If the process catches SIGCONT, let it
2176 * handle the signal itself. If it isn't waiting on
2177 * an event, it goes back to run state.
2178 * Otherwise, process goes back to sleep state.
2179 */
2180 p->p_flag &= ~P_STOPPED_SIG;
2181 PROC_SLOCK(p);
2182 if (p->p_numthreads == p->p_suspcount) {
2183 PROC_SUNLOCK(p);
2184 p->p_flag |= P_CONTINUED;
2185 p->p_xstat = SIGCONT;
2186 PROC_LOCK(p->p_pptr);
2187 childproc_continued(p);
2188 PROC_UNLOCK(p->p_pptr);
2189 PROC_SLOCK(p);
2190 }
2191 if (action == SIG_DFL) {
2192 thread_unsuspend(p);
2193 PROC_SUNLOCK(p);
2194 sigqueue_delete(sigqueue, sig);
2195 goto out;
2196 }
2197 if (action == SIG_CATCH) {
2198 /*
2199 * The process wants to catch it so it needs
2200 * to run at least one thread, but which one?
2201 */
2202 PROC_SUNLOCK(p);
2203 goto runfast;
2204 }
2205 /*
2206 * The signal is not ignored or caught.
2207 */
2208 thread_unsuspend(p);
2209 PROC_SUNLOCK(p);
2210 goto out;
2211 }
2212
2213 if (prop & SA_STOP) {
2214 /*
2215 * If traced process is already stopped,
2216 * then no further action is necessary.
2217 */
2218 if (p->p_flag & P_TRACED)
2219 goto out;
2220 /*
2221 * Already stopped, don't need to stop again
2222 * (If we did the shell could get confused).
2223 * Just make sure the signal STOP bit set.
2224 */
2225 p->p_flag |= P_STOPPED_SIG;
2226 sigqueue_delete(sigqueue, sig);
2227 goto out;
2228 }
2229
2230 /*
2231 * All other kinds of signals:
2232 * If a thread is sleeping interruptibly, simulate a
2233 * wakeup so that when it is continued it will be made
2234 * runnable and can look at the signal. However, don't make
2235 * the PROCESS runnable, leave it stopped.
2236 * It may run a bit until it hits a thread_suspend_check().
2237 */
2238 wakeup_swapper = 0;
2239 PROC_SLOCK(p);
2240 thread_lock(td);
2241 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR))
2242 wakeup_swapper = sleepq_abort(td, intrval);
2243 thread_unlock(td);
2244 PROC_SUNLOCK(p);
2245 if (wakeup_swapper)
2246 kick_proc0();
2247 goto out;
2248 /*
2249 * Mutexes are short lived. Threads waiting on them will
2250 * hit thread_suspend_check() soon.
2251 */
2252 } else if (p->p_state == PRS_NORMAL) {
2253 if (p->p_flag & P_TRACED || action == SIG_CATCH) {
2254 tdsigwakeup(td, sig, action, intrval);
2255 goto out;
2256 }
2257
2258 MPASS(action == SIG_DFL);
2259
2260 if (prop & SA_STOP) {
2261 if (p->p_flag & (P_PPWAIT|P_WEXIT))
2262 goto out;
2263 p->p_flag |= P_STOPPED_SIG;
2264 p->p_xstat = sig;
2265 PROC_SLOCK(p);
2266 sig_suspend_threads(td, p, 1);
2267 if (p->p_numthreads == p->p_suspcount) {
2268 /*
2269 * only thread sending signal to another
2270 * process can reach here, if thread is sending
2271 * signal to its process, because thread does
2272 * not suspend itself here, p_numthreads
2273 * should never be equal to p_suspcount.
2274 */
2275 thread_stopped(p);
2276 PROC_SUNLOCK(p);
2277 sigqueue_delete_proc(p, p->p_xstat);
2278 } else
2279 PROC_SUNLOCK(p);
2280 goto out;
2281 }
2282 } else {
2283 /* Not in "NORMAL" state. discard the signal. */
2284 sigqueue_delete(sigqueue, sig);
2285 goto out;
2286 }
2287
2288 /*
2289 * The process is not stopped so we need to apply the signal to all the
2290 * running threads.
2291 */
2292 runfast:
2293 tdsigwakeup(td, sig, action, intrval);
2294 PROC_SLOCK(p);
2295 thread_unsuspend(p);
2296 PROC_SUNLOCK(p);
2297 out:
2298 /* If we jump here, proc slock should not be owned. */
2299 PROC_SLOCK_ASSERT(p, MA_NOTOWNED);
2300 return (ret);
2301 }
2302
2303 /*
2304 * The force of a signal has been directed against a single
2305 * thread. We need to see what we can do about knocking it
2306 * out of any sleep it may be in etc.
2307 */
2308 static void
2309 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval)
2310 {
2311 struct proc *p = td->td_proc;
2312 register int prop;
2313 int wakeup_swapper;
2314
2315 wakeup_swapper = 0;
2316 PROC_LOCK_ASSERT(p, MA_OWNED);
2317 prop = sigprop(sig);
2318
2319 PROC_SLOCK(p);
2320 thread_lock(td);
2321 /*
2322 * Bring the priority of a thread up if we want it to get
2323 * killed in this lifetime.
2324 */
2325 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER)
2326 sched_prio(td, PUSER);
2327 if (TD_ON_SLEEPQ(td)) {
2328 /*
2329 * If thread is sleeping uninterruptibly
2330 * we can't interrupt the sleep... the signal will
2331 * be noticed when the process returns through
2332 * trap() or syscall().
2333 */
2334 if ((td->td_flags & TDF_SINTR) == 0)
2335 goto out;
2336 /*
2337 * If SIGCONT is default (or ignored) and process is
2338 * asleep, we are finished; the process should not
2339 * be awakened.
2340 */
2341 if ((prop & SA_CONT) && action == SIG_DFL) {
2342 thread_unlock(td);
2343 PROC_SUNLOCK(p);
2344 sigqueue_delete(&p->p_sigqueue, sig);
2345 /*
2346 * It may be on either list in this state.
2347 * Remove from both for now.
2348 */
2349 sigqueue_delete(&td->td_sigqueue, sig);
2350 return;
2351 }
2352
2353 /*
2354 * Don't awaken a sleeping thread for SIGSTOP if the
2355 * STOP signal is deferred.
2356 */
2357 if ((prop & SA_STOP) && (td->td_flags & TDF_SBDRY))
2358 goto out;
2359
2360 /*
2361 * Give low priority threads a better chance to run.
2362 */
2363 if (td->td_priority > PUSER)
2364 sched_prio(td, PUSER);
2365
2366 wakeup_swapper = sleepq_abort(td, intrval);
2367 } else {
2368 /*
2369 * Other states do nothing with the signal immediately,
2370 * other than kicking ourselves if we are running.
2371 * It will either never be noticed, or noticed very soon.
2372 */
2373 #ifdef SMP
2374 if (TD_IS_RUNNING(td) && td != curthread)
2375 forward_signal(td);
2376 #endif
2377 }
2378 out:
2379 PROC_SUNLOCK(p);
2380 thread_unlock(td);
2381 if (wakeup_swapper)
2382 kick_proc0();
2383 }
2384
2385 static void
2386 sig_suspend_threads(struct thread *td, struct proc *p, int sending)
2387 {
2388 struct thread *td2;
2389 int wakeup_swapper;
2390
2391 PROC_LOCK_ASSERT(p, MA_OWNED);
2392 PROC_SLOCK_ASSERT(p, MA_OWNED);
2393
2394 wakeup_swapper = 0;
2395 FOREACH_THREAD_IN_PROC(p, td2) {
2396 thread_lock(td2);
2397 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK;
2398 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) &&
2399 (td2->td_flags & TDF_SINTR)) {
2400 if (td2->td_flags & TDF_SBDRY) {
2401 /*
2402 * Once a thread is asleep with
2403 * TDF_SBDRY set, it should never
2404 * become suspended due to this check.
2405 */
2406 KASSERT(!TD_IS_SUSPENDED(td2),
2407 ("thread with deferred stops suspended"));
2408 } else if (!TD_IS_SUSPENDED(td2)) {
2409 thread_suspend_one(td2);
2410 }
2411 } else if (!TD_IS_SUSPENDED(td2)) {
2412 if (sending || td != td2)
2413 td2->td_flags |= TDF_ASTPENDING;
2414 #ifdef SMP
2415 if (TD_IS_RUNNING(td2) && td2 != td)
2416 forward_signal(td2);
2417 #endif
2418 }
2419 thread_unlock(td2);
2420 }
2421 if (wakeup_swapper)
2422 kick_proc0();
2423 }
2424
2425 int
2426 ptracestop(struct thread *td, int sig)
2427 {
2428 struct proc *p = td->td_proc;
2429
2430 PROC_LOCK_ASSERT(p, MA_OWNED);
2431 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process"));
2432 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
2433 &p->p_mtx.lock_object, "Stopping for traced signal");
2434
2435 td->td_dbgflags |= TDB_XSIG;
2436 td->td_xsig = sig;
2437 PROC_SLOCK(p);
2438 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) {
2439 if (p->p_flag & P_SINGLE_EXIT) {
2440 td->td_dbgflags &= ~TDB_XSIG;
2441 PROC_SUNLOCK(p);
2442 return (sig);
2443 }
2444 /*
2445 * Just make wait() to work, the last stopped thread
2446 * will win.
2447 */
2448 p->p_xstat = sig;
2449 p->p_xthread = td;
2450 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE);
2451 sig_suspend_threads(td, p, 0);
2452 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) {
2453 td->td_dbgflags &= ~TDB_STOPATFORK;
2454 cv_broadcast(&p->p_dbgwait);
2455 }
2456 stopme:
2457 thread_suspend_switch(td);
2458 if (!(p->p_flag & P_TRACED)) {
2459 break;
2460 }
2461 if (td->td_dbgflags & TDB_SUSPEND) {
2462 if (p->p_flag & P_SINGLE_EXIT)
2463 break;
2464 goto stopme;
2465 }
2466 }
2467 PROC_SUNLOCK(p);
2468 return (td->td_xsig);
2469 }
2470
2471 static void
2472 reschedule_signals(struct proc *p, sigset_t block, int flags)
2473 {
2474 struct sigacts *ps;
2475 struct thread *td;
2476 int i;
2477
2478 PROC_LOCK_ASSERT(p, MA_OWNED);
2479
2480 ps = p->p_sigacts;
2481 for (i = 1; !SIGISEMPTY(block); i++) {
2482 if (!SIGISMEMBER(block, i))
2483 continue;
2484 SIGDELSET(block, i);
2485 if (!SIGISMEMBER(p->p_siglist, i))
2486 continue;
2487
2488 td = sigtd(p, i, 0);
2489 signotify(td);
2490 if (!(flags & SIGPROCMASK_PS_LOCKED))
2491 mtx_lock(&ps->ps_mtx);
2492 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, i))
2493 tdsigwakeup(td, i, SIG_CATCH,
2494 (SIGISMEMBER(ps->ps_sigintr, i) ? EINTR :
2495 ERESTART));
2496 if (!(flags & SIGPROCMASK_PS_LOCKED))
2497 mtx_unlock(&ps->ps_mtx);
2498 }
2499 }
2500
2501 void
2502 tdsigcleanup(struct thread *td)
2503 {
2504 struct proc *p;
2505 sigset_t unblocked;
2506
2507 p = td->td_proc;
2508 PROC_LOCK_ASSERT(p, MA_OWNED);
2509
2510 sigqueue_flush(&td->td_sigqueue);
2511 if (p->p_numthreads == 1)
2512 return;
2513
2514 /*
2515 * Since we cannot handle signals, notify signal post code
2516 * about this by filling the sigmask.
2517 *
2518 * Also, if needed, wake up thread(s) that do not block the
2519 * same signals as the exiting thread, since the thread might
2520 * have been selected for delivery and woken up.
2521 */
2522 SIGFILLSET(unblocked);
2523 SIGSETNAND(unblocked, td->td_sigmask);
2524 SIGFILLSET(td->td_sigmask);
2525 reschedule_signals(p, unblocked, 0);
2526
2527 }
2528
2529 /*
2530 * Defer the delivery of SIGSTOP for the current thread. Returns true
2531 * if stops were deferred and false if they were already deferred.
2532 */
2533 int
2534 sigdeferstop(void)
2535 {
2536 struct thread *td;
2537
2538 td = curthread;
2539 if (td->td_flags & TDF_SBDRY)
2540 return (0);
2541 thread_lock(td);
2542 td->td_flags |= TDF_SBDRY;
2543 thread_unlock(td);
2544 return (1);
2545 }
2546
2547 /*
2548 * Permit the delivery of SIGSTOP for the current thread. This does
2549 * not immediately suspend if a stop was posted. Instead, the thread
2550 * will suspend either via ast() or a subsequent interruptible sleep.
2551 */
2552 void
2553 sigallowstop()
2554 {
2555 struct thread *td;
2556
2557 td = curthread;
2558 thread_lock(td);
2559 td->td_flags &= ~TDF_SBDRY;
2560 thread_unlock(td);
2561 }
2562
2563 /*
2564 * If the current process has received a signal (should be caught or cause
2565 * termination, should interrupt current syscall), return the signal number.
2566 * Stop signals with default action are processed immediately, then cleared;
2567 * they aren't returned. This is checked after each entry to the system for
2568 * a syscall or trap (though this can usually be done without calling issignal
2569 * by checking the pending signal masks in cursig.) The normal call
2570 * sequence is
2571 *
2572 * while (sig = cursig(curthread))
2573 * postsig(sig);
2574 */
2575 static int
2576 issignal(struct thread *td, int stop_allowed)
2577 {
2578 struct proc *p;
2579 struct sigacts *ps;
2580 struct sigqueue *queue;
2581 sigset_t sigpending;
2582 int sig, prop, newsig;
2583
2584 p = td->td_proc;
2585 ps = p->p_sigacts;
2586 mtx_assert(&ps->ps_mtx, MA_OWNED);
2587 PROC_LOCK_ASSERT(p, MA_OWNED);
2588 for (;;) {
2589 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
2590
2591 sigpending = td->td_sigqueue.sq_signals;
2592 SIGSETOR(sigpending, p->p_sigqueue.sq_signals);
2593 SIGSETNAND(sigpending, td->td_sigmask);
2594
2595 if (p->p_flag & P_PPWAIT || td->td_flags & TDF_SBDRY)
2596 SIG_STOPSIGMASK(sigpending);
2597 if (SIGISEMPTY(sigpending)) /* no signal to send */
2598 return (0);
2599 sig = sig_ffs(&sigpending);
2600
2601 if (p->p_stops & S_SIG) {
2602 mtx_unlock(&ps->ps_mtx);
2603 stopevent(p, S_SIG, sig);
2604 mtx_lock(&ps->ps_mtx);
2605 }
2606
2607 /*
2608 * We should see pending but ignored signals
2609 * only if P_TRACED was on when they were posted.
2610 */
2611 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) {
2612 sigqueue_delete(&td->td_sigqueue, sig);
2613 sigqueue_delete(&p->p_sigqueue, sig);
2614 continue;
2615 }
2616 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) {
2617 /*
2618 * If traced, always stop.
2619 * Remove old signal from queue before the stop.
2620 * XXX shrug off debugger, it causes siginfo to
2621 * be thrown away.
2622 */
2623 queue = &td->td_sigqueue;
2624 td->td_dbgksi.ksi_signo = 0;
2625 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) {
2626 queue = &p->p_sigqueue;
2627 sigqueue_get(queue, sig, &td->td_dbgksi);
2628 }
2629
2630 mtx_unlock(&ps->ps_mtx);
2631 newsig = ptracestop(td, sig);
2632 mtx_lock(&ps->ps_mtx);
2633
2634 if (sig != newsig) {
2635
2636 /*
2637 * If parent wants us to take the signal,
2638 * then it will leave it in p->p_xstat;
2639 * otherwise we just look for signals again.
2640 */
2641 if (newsig == 0)
2642 continue;
2643 sig = newsig;
2644
2645 /*
2646 * Put the new signal into td_sigqueue. If the
2647 * signal is being masked, look for other signals.
2648 */
2649 sigqueue_add(queue, sig, NULL);
2650 if (SIGISMEMBER(td->td_sigmask, sig))
2651 continue;
2652 signotify(td);
2653 } else {
2654 if (td->td_dbgksi.ksi_signo != 0) {
2655 td->td_dbgksi.ksi_flags |= KSI_HEAD;
2656 if (sigqueue_add(&td->td_sigqueue, sig,
2657 &td->td_dbgksi) != 0)
2658 td->td_dbgksi.ksi_signo = 0;
2659 }
2660 if (td->td_dbgksi.ksi_signo == 0)
2661 sigqueue_add(&td->td_sigqueue, sig,
2662 NULL);
2663 }
2664
2665 /*
2666 * If the traced bit got turned off, go back up
2667 * to the top to rescan signals. This ensures
2668 * that p_sig* and p_sigact are consistent.
2669 */
2670 if ((p->p_flag & P_TRACED) == 0)
2671 continue;
2672 }
2673
2674 prop = sigprop(sig);
2675
2676 /*
2677 * Decide whether the signal should be returned.
2678 * Return the signal's number, or fall through
2679 * to clear it from the pending mask.
2680 */
2681 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
2682
2683 case (intptr_t)SIG_DFL:
2684 /*
2685 * Don't take default actions on system processes.
2686 */
2687 if (p->p_pid <= 1) {
2688 #ifdef DIAGNOSTIC
2689 /*
2690 * Are you sure you want to ignore SIGSEGV
2691 * in init? XXX
2692 */
2693 printf("Process (pid %lu) got signal %d\n",
2694 (u_long)p->p_pid, sig);
2695 #endif
2696 break; /* == ignore */
2697 }
2698 /*
2699 * If there is a pending stop signal to process
2700 * with default action, stop here,
2701 * then clear the signal. However,
2702 * if process is member of an orphaned
2703 * process group, ignore tty stop signals.
2704 */
2705 if (prop & SA_STOP) {
2706 if (p->p_flag & (P_TRACED|P_WEXIT) ||
2707 (p->p_pgrp->pg_jobc == 0 &&
2708 prop & SA_TTYSTOP))
2709 break; /* == ignore */
2710 mtx_unlock(&ps->ps_mtx);
2711 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
2712 &p->p_mtx.lock_object, "Catching SIGSTOP");
2713 p->p_flag |= P_STOPPED_SIG;
2714 p->p_xstat = sig;
2715 PROC_SLOCK(p);
2716 sig_suspend_threads(td, p, 0);
2717 thread_suspend_switch(td);
2718 PROC_SUNLOCK(p);
2719 mtx_lock(&ps->ps_mtx);
2720 break;
2721 } else if (prop & SA_IGNORE) {
2722 /*
2723 * Except for SIGCONT, shouldn't get here.
2724 * Default action is to ignore; drop it.
2725 */
2726 break; /* == ignore */
2727 } else
2728 return (sig);
2729 /*NOTREACHED*/
2730
2731 case (intptr_t)SIG_IGN:
2732 /*
2733 * Masking above should prevent us ever trying
2734 * to take action on an ignored signal other
2735 * than SIGCONT, unless process is traced.
2736 */
2737 if ((prop & SA_CONT) == 0 &&
2738 (p->p_flag & P_TRACED) == 0)
2739 printf("issignal\n");
2740 break; /* == ignore */
2741
2742 default:
2743 /*
2744 * This signal has an action, let
2745 * postsig() process it.
2746 */
2747 return (sig);
2748 }
2749 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */
2750 sigqueue_delete(&p->p_sigqueue, sig);
2751 }
2752 /* NOTREACHED */
2753 }
2754
2755 void
2756 thread_stopped(struct proc *p)
2757 {
2758 int n;
2759
2760 PROC_LOCK_ASSERT(p, MA_OWNED);
2761 PROC_SLOCK_ASSERT(p, MA_OWNED);
2762 n = p->p_suspcount;
2763 if (p == curproc)
2764 n++;
2765 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) {
2766 PROC_SUNLOCK(p);
2767 p->p_flag &= ~P_WAITED;
2768 PROC_LOCK(p->p_pptr);
2769 childproc_stopped(p, (p->p_flag & P_TRACED) ?
2770 CLD_TRAPPED : CLD_STOPPED);
2771 PROC_UNLOCK(p->p_pptr);
2772 PROC_SLOCK(p);
2773 }
2774 }
2775
2776 /*
2777 * Take the action for the specified signal
2778 * from the current set of pending signals.
2779 */
2780 int
2781 postsig(sig)
2782 register int sig;
2783 {
2784 struct thread *td = curthread;
2785 register struct proc *p = td->td_proc;
2786 struct sigacts *ps;
2787 sig_t action;
2788 ksiginfo_t ksi;
2789 sigset_t returnmask, mask;
2790
2791 KASSERT(sig != 0, ("postsig"));
2792
2793 PROC_LOCK_ASSERT(p, MA_OWNED);
2794 ps = p->p_sigacts;
2795 mtx_assert(&ps->ps_mtx, MA_OWNED);
2796 ksiginfo_init(&ksi);
2797 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 &&
2798 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0)
2799 return (0);
2800 ksi.ksi_signo = sig;
2801 if (ksi.ksi_code == SI_TIMER)
2802 itimer_accept(p, ksi.ksi_timerid, &ksi);
2803 action = ps->ps_sigact[_SIG_IDX(sig)];
2804 #ifdef KTRACE
2805 if (KTRPOINT(td, KTR_PSIG))
2806 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ?
2807 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code);
2808 #endif
2809 if (p->p_stops & S_SIG) {
2810 mtx_unlock(&ps->ps_mtx);
2811 stopevent(p, S_SIG, sig);
2812 mtx_lock(&ps->ps_mtx);
2813 }
2814
2815 if (action == SIG_DFL) {
2816 /*
2817 * Default action, where the default is to kill
2818 * the process. (Other cases were ignored above.)
2819 */
2820 mtx_unlock(&ps->ps_mtx);
2821 sigexit(td, sig);
2822 /* NOTREACHED */
2823 } else {
2824 /*
2825 * If we get here, the signal must be caught.
2826 */
2827 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig),
2828 ("postsig action"));
2829 /*
2830 * Set the new mask value and also defer further
2831 * occurrences of this signal.
2832 *
2833 * Special case: user has done a sigsuspend. Here the
2834 * current mask is not of interest, but rather the
2835 * mask from before the sigsuspend is what we want
2836 * restored after the signal processing is completed.
2837 */
2838 if (td->td_pflags & TDP_OLDMASK) {
2839 returnmask = td->td_oldsigmask;
2840 td->td_pflags &= ~TDP_OLDMASK;
2841 } else
2842 returnmask = td->td_sigmask;
2843
2844 mask = ps->ps_catchmask[_SIG_IDX(sig)];
2845 if (!SIGISMEMBER(ps->ps_signodefer, sig))
2846 SIGADDSET(mask, sig);
2847 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL,
2848 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED);
2849
2850 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
2851 /*
2852 * See kern_sigaction() for origin of this code.
2853 */
2854 SIGDELSET(ps->ps_sigcatch, sig);
2855 if (sig != SIGCONT &&
2856 sigprop(sig) & SA_IGNORE)
2857 SIGADDSET(ps->ps_sigignore, sig);
2858 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
2859 }
2860 td->td_ru.ru_nsignals++;
2861 if (p->p_sig == sig) {
2862 p->p_code = 0;
2863 p->p_sig = 0;
2864 }
2865 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask);
2866 }
2867 return (1);
2868 }
2869
2870 /*
2871 * Kill the current process for stated reason.
2872 */
2873 void
2874 killproc(p, why)
2875 struct proc *p;
2876 char *why;
2877 {
2878
2879 PROC_LOCK_ASSERT(p, MA_OWNED);
2880 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)",
2881 p, p->p_pid, p->p_comm);
2882 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm,
2883 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
2884 p->p_flag |= P_WKILLED;
2885 psignal(p, SIGKILL);
2886 }
2887
2888 /*
2889 * Force the current process to exit with the specified signal, dumping core
2890 * if appropriate. We bypass the normal tests for masked and caught signals,
2891 * allowing unrecoverable failures to terminate the process without changing
2892 * signal state. Mark the accounting record with the signal termination.
2893 * If dumping core, save the signal number for the debugger. Calls exit and
2894 * does not return.
2895 */
2896 void
2897 sigexit(td, sig)
2898 struct thread *td;
2899 int sig;
2900 {
2901 struct proc *p = td->td_proc;
2902
2903 PROC_LOCK_ASSERT(p, MA_OWNED);
2904 p->p_acflag |= AXSIG;
2905 /*
2906 * We must be single-threading to generate a core dump. This
2907 * ensures that the registers in the core file are up-to-date.
2908 * Also, the ELF dump handler assumes that the thread list doesn't
2909 * change out from under it.
2910 *
2911 * XXX If another thread attempts to single-thread before us
2912 * (e.g. via fork()), we won't get a dump at all.
2913 */
2914 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) {
2915 p->p_sig = sig;
2916 /*
2917 * Log signals which would cause core dumps
2918 * (Log as LOG_INFO to appease those who don't want
2919 * these messages.)
2920 * XXX : Todo, as well as euid, write out ruid too
2921 * Note that coredump() drops proc lock.
2922 */
2923 if (coredump(td) == 0)
2924 sig |= WCOREFLAG;
2925 if (kern_logsigexit)
2926 log(LOG_INFO,
2927 "pid %d (%s), uid %d: exited on signal %d%s\n",
2928 p->p_pid, p->p_comm,
2929 td->td_ucred ? td->td_ucred->cr_uid : -1,
2930 sig &~ WCOREFLAG,
2931 sig & WCOREFLAG ? " (core dumped)" : "");
2932 } else
2933 PROC_UNLOCK(p);
2934 exit1(td, W_EXITCODE(0, sig));
2935 /* NOTREACHED */
2936 }
2937
2938 /*
2939 * Send queued SIGCHLD to parent when child process's state
2940 * is changed.
2941 */
2942 static void
2943 sigparent(struct proc *p, int reason, int status)
2944 {
2945 PROC_LOCK_ASSERT(p, MA_OWNED);
2946 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
2947
2948 if (p->p_ksi != NULL) {
2949 p->p_ksi->ksi_signo = SIGCHLD;
2950 p->p_ksi->ksi_code = reason;
2951 p->p_ksi->ksi_status = status;
2952 p->p_ksi->ksi_pid = p->p_pid;
2953 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid;
2954 if (KSI_ONQ(p->p_ksi))
2955 return;
2956 }
2957 tdsignal(p->p_pptr, NULL, SIGCHLD, p->p_ksi);
2958 }
2959
2960 static void
2961 childproc_jobstate(struct proc *p, int reason, int status)
2962 {
2963 struct sigacts *ps;
2964
2965 PROC_LOCK_ASSERT(p, MA_OWNED);
2966 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
2967
2968 /*
2969 * Wake up parent sleeping in kern_wait(), also send
2970 * SIGCHLD to parent, but SIGCHLD does not guarantee
2971 * that parent will awake, because parent may masked
2972 * the signal.
2973 */
2974 p->p_pptr->p_flag |= P_STATCHILD;
2975 wakeup(p->p_pptr);
2976
2977 ps = p->p_pptr->p_sigacts;
2978 mtx_lock(&ps->ps_mtx);
2979 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) {
2980 mtx_unlock(&ps->ps_mtx);
2981 sigparent(p, reason, status);
2982 } else
2983 mtx_unlock(&ps->ps_mtx);
2984 }
2985
2986 void
2987 childproc_stopped(struct proc *p, int reason)
2988 {
2989 childproc_jobstate(p, reason, p->p_xstat);
2990 }
2991
2992 void
2993 childproc_continued(struct proc *p)
2994 {
2995 childproc_jobstate(p, CLD_CONTINUED, SIGCONT);
2996 }
2997
2998 void
2999 childproc_exited(struct proc *p)
3000 {
3001 int reason;
3002 int status = p->p_xstat; /* convert to int */
3003
3004 reason = CLD_EXITED;
3005 if (WCOREDUMP(status))
3006 reason = CLD_DUMPED;
3007 else if (WIFSIGNALED(status))
3008 reason = CLD_KILLED;
3009 /*
3010 * XXX avoid calling wakeup(p->p_pptr), the work is
3011 * done in exit1().
3012 */
3013 sigparent(p, reason, status);
3014 }
3015
3016 static char corefilename[MAXPATHLEN] = {"%N.core"};
3017 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
3018 sizeof(corefilename), "process corefile name format string");
3019
3020 /*
3021 * expand_name(name, uid, pid)
3022 * Expand the name described in corefilename, using name, uid, and pid.
3023 * corefilename is a printf-like string, with three format specifiers:
3024 * %N name of process ("name")
3025 * %P process id (pid)
3026 * %U user id (uid)
3027 * For example, "%N.core" is the default; they can be disabled completely
3028 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
3029 * This is controlled by the sysctl variable kern.corefile (see above).
3030 */
3031 static char *
3032 expand_name(name, uid, pid)
3033 const char *name;
3034 uid_t uid;
3035 pid_t pid;
3036 {
3037 struct sbuf sb;
3038 const char *format;
3039 char *temp;
3040 size_t i;
3041
3042 format = corefilename;
3043 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO);
3044 if (temp == NULL)
3045 return (NULL);
3046 (void)sbuf_new(&sb, temp, MAXPATHLEN, SBUF_FIXEDLEN);
3047 for (i = 0; format[i]; i++) {
3048 switch (format[i]) {
3049 case '%': /* Format character */
3050 i++;
3051 switch (format[i]) {
3052 case '%':
3053 sbuf_putc(&sb, '%');
3054 break;
3055 case 'N': /* process name */
3056 sbuf_printf(&sb, "%s", name);
3057 break;
3058 case 'P': /* process id */
3059 sbuf_printf(&sb, "%u", pid);
3060 break;
3061 case 'U': /* user id */
3062 sbuf_printf(&sb, "%u", uid);
3063 break;
3064 default:
3065 log(LOG_ERR,
3066 "Unknown format character %c in "
3067 "corename `%s'\n", format[i], format);
3068 }
3069 break;
3070 default:
3071 sbuf_putc(&sb, format[i]);
3072 }
3073 }
3074 if (sbuf_overflowed(&sb)) {
3075 sbuf_delete(&sb);
3076 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too "
3077 "long\n", (long)pid, name, (u_long)uid);
3078 free(temp, M_TEMP);
3079 return (NULL);
3080 }
3081 sbuf_finish(&sb);
3082 sbuf_delete(&sb);
3083 return (temp);
3084 }
3085
3086 /*
3087 * Dump a process' core. The main routine does some
3088 * policy checking, and creates the name of the coredump;
3089 * then it passes on a vnode and a size limit to the process-specific
3090 * coredump routine if there is one; if there _is not_ one, it returns
3091 * ENOSYS; otherwise it returns the error from the process-specific routine.
3092 */
3093
3094 static int
3095 coredump(struct thread *td)
3096 {
3097 struct proc *p = td->td_proc;
3098 register struct vnode *vp;
3099 register struct ucred *cred = td->td_ucred;
3100 struct flock lf;
3101 struct nameidata nd;
3102 struct vattr vattr;
3103 int error, error1, flags, locked;
3104 struct mount *mp;
3105 char *name; /* name of corefile */
3106 off_t limit;
3107 int vfslocked;
3108
3109 PROC_LOCK_ASSERT(p, MA_OWNED);
3110 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td);
3111 _STOPEVENT(p, S_CORE, 0);
3112
3113 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid);
3114 if (name == NULL) {
3115 PROC_UNLOCK(p);
3116 #ifdef AUDIT
3117 audit_proc_coredump(td, NULL, EINVAL);
3118 #endif
3119 return (EINVAL);
3120 }
3121 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) {
3122 PROC_UNLOCK(p);
3123 #ifdef AUDIT
3124 audit_proc_coredump(td, name, EFAULT);
3125 #endif
3126 free(name, M_TEMP);
3127 return (EFAULT);
3128 }
3129
3130 /*
3131 * Note that the bulk of limit checking is done after
3132 * the corefile is created. The exception is if the limit
3133 * for corefiles is 0, in which case we don't bother
3134 * creating the corefile at all. This layout means that
3135 * a corefile is truncated instead of not being created,
3136 * if it is larger than the limit.
3137 */
3138 limit = (off_t)lim_cur(p, RLIMIT_CORE);
3139 PROC_UNLOCK(p);
3140 if (limit == 0) {
3141 #ifdef AUDIT
3142 audit_proc_coredump(td, name, EFBIG);
3143 #endif
3144 free(name, M_TEMP);
3145 return (EFBIG);
3146 }
3147
3148 restart:
3149 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, name, td);
3150 flags = O_CREAT | FWRITE | O_NOFOLLOW;
3151 error = vn_open_cred(&nd, &flags, S_IRUSR | S_IWUSR, VN_OPEN_NOAUDIT,
3152 cred, NULL);
3153 if (error) {
3154 #ifdef AUDIT
3155 audit_proc_coredump(td, name, error);
3156 #endif
3157 free(name, M_TEMP);
3158 return (error);
3159 }
3160 vfslocked = NDHASGIANT(&nd);
3161 NDFREE(&nd, NDF_ONLY_PNBUF);
3162 vp = nd.ni_vp;
3163
3164 /* Don't dump to non-regular files or files with links. */
3165 if (vp->v_type != VREG ||
3166 VOP_GETATTR(vp, &vattr, cred) || vattr.va_nlink != 1) {
3167 VOP_UNLOCK(vp, 0);
3168 error = EFAULT;
3169 goto close;
3170 }
3171
3172 VOP_UNLOCK(vp, 0);
3173 lf.l_whence = SEEK_SET;
3174 lf.l_start = 0;
3175 lf.l_len = 0;
3176 lf.l_type = F_WRLCK;
3177 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0);
3178
3179 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
3180 lf.l_type = F_UNLCK;
3181 if (locked)
3182 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
3183 if ((error = vn_close(vp, FWRITE, cred, td)) != 0)
3184 goto out;
3185 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
3186 goto out;
3187 VFS_UNLOCK_GIANT(vfslocked);
3188 goto restart;
3189 }
3190
3191 VATTR_NULL(&vattr);
3192 vattr.va_size = 0;
3193 if (set_core_nodump_flag)
3194 vattr.va_flags = UF_NODUMP;
3195 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3196 VOP_SETATTR(vp, &vattr, cred);
3197 VOP_UNLOCK(vp, 0);
3198 vn_finished_write(mp);
3199 PROC_LOCK(p);
3200 p->p_acflag |= ACORE;
3201 PROC_UNLOCK(p);
3202
3203 error = p->p_sysent->sv_coredump ?
3204 p->p_sysent->sv_coredump(td, vp, limit) :
3205 ENOSYS;
3206
3207 if (locked) {
3208 lf.l_type = F_UNLCK;
3209 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
3210 }
3211 close:
3212 error1 = vn_close(vp, FWRITE, cred, td);
3213 if (error == 0)
3214 error = error1;
3215 out:
3216 #ifdef AUDIT
3217 audit_proc_coredump(td, name, error);
3218 #endif
3219 free(name, M_TEMP);
3220 VFS_UNLOCK_GIANT(vfslocked);
3221 return (error);
3222 }
3223
3224 /*
3225 * Nonexistent system call-- signal process (may want to handle it). Flag
3226 * error in case process won't see signal immediately (blocked or ignored).
3227 */
3228 #ifndef _SYS_SYSPROTO_H_
3229 struct nosys_args {
3230 int dummy;
3231 };
3232 #endif
3233 /* ARGSUSED */
3234 int
3235 nosys(td, args)
3236 struct thread *td;
3237 struct nosys_args *args;
3238 {
3239 struct proc *p = td->td_proc;
3240
3241 PROC_LOCK(p);
3242 psignal(p, SIGSYS);
3243 PROC_UNLOCK(p);
3244 return (ENOSYS);
3245 }
3246
3247 /*
3248 * Send a SIGIO or SIGURG signal to a process or process group using stored
3249 * credentials rather than those of the current process.
3250 */
3251 void
3252 pgsigio(sigiop, sig, checkctty)
3253 struct sigio **sigiop;
3254 int sig, checkctty;
3255 {
3256 ksiginfo_t ksi;
3257 struct sigio *sigio;
3258
3259 ksiginfo_init(&ksi);
3260 ksi.ksi_signo = sig;
3261 ksi.ksi_code = SI_KERNEL;
3262
3263 SIGIO_LOCK();
3264 sigio = *sigiop;
3265 if (sigio == NULL) {
3266 SIGIO_UNLOCK();
3267 return;
3268 }
3269 if (sigio->sio_pgid > 0) {
3270 PROC_LOCK(sigio->sio_proc);
3271 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred))
3272 psignal(sigio->sio_proc, sig);
3273 PROC_UNLOCK(sigio->sio_proc);
3274 } else if (sigio->sio_pgid < 0) {
3275 struct proc *p;
3276
3277 PGRP_LOCK(sigio->sio_pgrp);
3278 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
3279 PROC_LOCK(p);
3280 if (p->p_state == PRS_NORMAL &&
3281 CANSIGIO(sigio->sio_ucred, p->p_ucred) &&
3282 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
3283 psignal(p, sig);
3284 PROC_UNLOCK(p);
3285 }
3286 PGRP_UNLOCK(sigio->sio_pgrp);
3287 }
3288 SIGIO_UNLOCK();
3289 }
3290
3291 static int
3292 filt_sigattach(struct knote *kn)
3293 {
3294 struct proc *p = curproc;
3295
3296 kn->kn_ptr.p_proc = p;
3297 kn->kn_flags |= EV_CLEAR; /* automatically set */
3298
3299 knlist_add(&p->p_klist, kn, 0);
3300
3301 return (0);
3302 }
3303
3304 static void
3305 filt_sigdetach(struct knote *kn)
3306 {
3307 struct proc *p = kn->kn_ptr.p_proc;
3308
3309 knlist_remove(&p->p_klist, kn, 0);
3310 }
3311
3312 /*
3313 * signal knotes are shared with proc knotes, so we apply a mask to
3314 * the hint in order to differentiate them from process hints. This
3315 * could be avoided by using a signal-specific knote list, but probably
3316 * isn't worth the trouble.
3317 */
3318 static int
3319 filt_signal(struct knote *kn, long hint)
3320 {
3321
3322 if (hint & NOTE_SIGNAL) {
3323 hint &= ~NOTE_SIGNAL;
3324
3325 if (kn->kn_id == hint)
3326 kn->kn_data++;
3327 }
3328 return (kn->kn_data != 0);
3329 }
3330
3331 struct sigacts *
3332 sigacts_alloc(void)
3333 {
3334 struct sigacts *ps;
3335
3336 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO);
3337 ps->ps_refcnt = 1;
3338 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF);
3339 return (ps);
3340 }
3341
3342 void
3343 sigacts_free(struct sigacts *ps)
3344 {
3345
3346 mtx_lock(&ps->ps_mtx);
3347 ps->ps_refcnt--;
3348 if (ps->ps_refcnt == 0) {
3349 mtx_destroy(&ps->ps_mtx);
3350 free(ps, M_SUBPROC);
3351 } else
3352 mtx_unlock(&ps->ps_mtx);
3353 }
3354
3355 struct sigacts *
3356 sigacts_hold(struct sigacts *ps)
3357 {
3358 mtx_lock(&ps->ps_mtx);
3359 ps->ps_refcnt++;
3360 mtx_unlock(&ps->ps_mtx);
3361 return (ps);
3362 }
3363
3364 void
3365 sigacts_copy(struct sigacts *dest, struct sigacts *src)
3366 {
3367
3368 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest"));
3369 mtx_lock(&src->ps_mtx);
3370 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt));
3371 mtx_unlock(&src->ps_mtx);
3372 }
3373
3374 int
3375 sigacts_shared(struct sigacts *ps)
3376 {
3377 int shared;
3378
3379 mtx_lock(&ps->ps_mtx);
3380 shared = ps->ps_refcnt > 1;
3381 mtx_unlock(&ps->ps_mtx);
3382 return (shared);
3383 }
Cache object: dddd6d3b12a52c35cf3dae483c96777e
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