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_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/posix4.h>
61 #include <sys/pioctl.h>
62 #include <sys/resourcevar.h>
63 #include <sys/sleepqueue.h>
64 #include <sys/smp.h>
65 #include <sys/stat.h>
66 #include <sys/sx.h>
67 #include <sys/syscallsubr.h>
68 #include <sys/sysctl.h>
69 #include <sys/sysent.h>
70 #include <sys/syslog.h>
71 #include <sys/sysproto.h>
72 #include <sys/timers.h>
73 #include <sys/unistd.h>
74 #include <sys/wait.h>
75 #include <vm/vm.h>
76 #include <vm/vm_extern.h>
77 #include <vm/uma.h>
78
79 #include <machine/cpu.h>
80
81 #include <security/audit/audit.h>
82
83 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */
84
85 static int coredump(struct thread *);
86 static char *expand_name(const char *, uid_t, pid_t);
87 static int killpg1(struct thread *td, int sig, int pgid, int all);
88 static int issignal(struct thread *p);
89 static int sigprop(int sig);
90 static void tdsigwakeup(struct thread *, int, sig_t, int);
91 static void sig_suspend_threads(struct thread *, struct proc *, int);
92 static int filt_sigattach(struct knote *kn);
93 static void filt_sigdetach(struct knote *kn);
94 static int filt_signal(struct knote *kn, long hint);
95 static struct thread *sigtd(struct proc *p, int sig, int prop);
96 #ifdef KSE
97 static int do_tdsignal(struct proc *, struct thread *, int, ksiginfo_t *);
98 #endif
99 static void sigqueue_start(void);
100
101 static uma_zone_t ksiginfo_zone = NULL;
102 struct filterops sig_filtops =
103 { 0, filt_sigattach, filt_sigdetach, filt_signal };
104
105 int kern_logsigexit = 1;
106 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
107 &kern_logsigexit, 0,
108 "Log processes quitting on abnormal signals to syslog(3)");
109
110 static int kern_forcesigexit = 1;
111 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW,
112 &kern_forcesigexit, 0, "Force trap signal to be handled");
113
114 SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, "POSIX real time signal");
115
116 static int max_pending_per_proc = 128;
117 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW,
118 &max_pending_per_proc, 0, "Max pending signals per proc");
119
120 static int preallocate_siginfo = 1024;
121 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo);
122 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD,
123 &preallocate_siginfo, 0, "Preallocated signal memory size");
124
125 static int signal_overflow = 0;
126 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD,
127 &signal_overflow, 0, "Number of signals overflew");
128
129 static int signal_alloc_fail = 0;
130 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD,
131 &signal_alloc_fail, 0, "signals failed to be allocated");
132
133 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL);
134
135 /*
136 * Policy -- Can ucred cr1 send SIGIO to process cr2?
137 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG
138 * in the right situations.
139 */
140 #define CANSIGIO(cr1, cr2) \
141 ((cr1)->cr_uid == 0 || \
142 (cr1)->cr_ruid == (cr2)->cr_ruid || \
143 (cr1)->cr_uid == (cr2)->cr_ruid || \
144 (cr1)->cr_ruid == (cr2)->cr_uid || \
145 (cr1)->cr_uid == (cr2)->cr_uid)
146
147 int sugid_coredump;
148 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
149 &sugid_coredump, 0, "Enable coredumping set user/group ID processes");
150
151 static int do_coredump = 1;
152 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
153 &do_coredump, 0, "Enable/Disable coredumps");
154
155 static int set_core_nodump_flag = 0;
156 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag,
157 0, "Enable setting the NODUMP flag on coredump files");
158
159 /*
160 * Signal properties and actions.
161 * The array below categorizes the signals and their default actions
162 * according to the following properties:
163 */
164 #define SA_KILL 0x01 /* terminates process by default */
165 #define SA_CORE 0x02 /* ditto and coredumps */
166 #define SA_STOP 0x04 /* suspend process */
167 #define SA_TTYSTOP 0x08 /* ditto, from tty */
168 #define SA_IGNORE 0x10 /* ignore by default */
169 #define SA_CONT 0x20 /* continue if suspended */
170 #define SA_CANTMASK 0x40 /* non-maskable, catchable */
171 #define SA_PROC 0x80 /* deliverable to any thread */
172
173 static int sigproptbl[NSIG] = {
174 SA_KILL|SA_PROC, /* SIGHUP */
175 SA_KILL|SA_PROC, /* SIGINT */
176 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */
177 SA_KILL|SA_CORE, /* SIGILL */
178 SA_KILL|SA_CORE, /* SIGTRAP */
179 SA_KILL|SA_CORE, /* SIGABRT */
180 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */
181 SA_KILL|SA_CORE, /* SIGFPE */
182 SA_KILL|SA_PROC, /* SIGKILL */
183 SA_KILL|SA_CORE, /* SIGBUS */
184 SA_KILL|SA_CORE, /* SIGSEGV */
185 SA_KILL|SA_CORE, /* SIGSYS */
186 SA_KILL|SA_PROC, /* SIGPIPE */
187 SA_KILL|SA_PROC, /* SIGALRM */
188 SA_KILL|SA_PROC, /* SIGTERM */
189 SA_IGNORE|SA_PROC, /* SIGURG */
190 SA_STOP|SA_PROC, /* SIGSTOP */
191 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */
192 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */
193 SA_IGNORE|SA_PROC, /* SIGCHLD */
194 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */
195 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */
196 SA_IGNORE|SA_PROC, /* SIGIO */
197 SA_KILL, /* SIGXCPU */
198 SA_KILL, /* SIGXFSZ */
199 SA_KILL|SA_PROC, /* SIGVTALRM */
200 SA_KILL|SA_PROC, /* SIGPROF */
201 SA_IGNORE|SA_PROC, /* SIGWINCH */
202 SA_IGNORE|SA_PROC, /* SIGINFO */
203 SA_KILL|SA_PROC, /* SIGUSR1 */
204 SA_KILL|SA_PROC, /* SIGUSR2 */
205 };
206
207 static void
208 sigqueue_start(void)
209 {
210 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t),
211 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
212 uma_prealloc(ksiginfo_zone, preallocate_siginfo);
213 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS);
214 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1);
215 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc);
216 }
217
218 ksiginfo_t *
219 ksiginfo_alloc(int wait)
220 {
221 int flags;
222
223 flags = M_ZERO;
224 if (! wait)
225 flags |= M_NOWAIT;
226 if (ksiginfo_zone != NULL)
227 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags));
228 return (NULL);
229 }
230
231 void
232 ksiginfo_free(ksiginfo_t *ksi)
233 {
234 uma_zfree(ksiginfo_zone, ksi);
235 }
236
237 static __inline int
238 ksiginfo_tryfree(ksiginfo_t *ksi)
239 {
240 if (!(ksi->ksi_flags & KSI_EXT)) {
241 uma_zfree(ksiginfo_zone, ksi);
242 return (1);
243 }
244 return (0);
245 }
246
247 void
248 sigqueue_init(sigqueue_t *list, struct proc *p)
249 {
250 SIGEMPTYSET(list->sq_signals);
251 SIGEMPTYSET(list->sq_kill);
252 TAILQ_INIT(&list->sq_list);
253 list->sq_proc = p;
254 list->sq_flags = SQ_INIT;
255 }
256
257 /*
258 * Get a signal's ksiginfo.
259 * Return:
260 * 0 - signal not found
261 * others - signal number
262 */
263 int
264 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si)
265 {
266 struct proc *p = sq->sq_proc;
267 struct ksiginfo *ksi, *next;
268 int count = 0;
269
270 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
271
272 if (!SIGISMEMBER(sq->sq_signals, signo))
273 return (0);
274
275 if (SIGISMEMBER(sq->sq_kill, signo)) {
276 count++;
277 SIGDELSET(sq->sq_kill, signo);
278 }
279
280 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
281 if (ksi->ksi_signo == signo) {
282 if (count == 0) {
283 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
284 ksi->ksi_sigq = NULL;
285 ksiginfo_copy(ksi, si);
286 if (ksiginfo_tryfree(ksi) && p != NULL)
287 p->p_pendingcnt--;
288 }
289 if (++count > 1)
290 break;
291 }
292 }
293
294 if (count <= 1)
295 SIGDELSET(sq->sq_signals, signo);
296 si->ksi_signo = signo;
297 return (signo);
298 }
299
300 void
301 sigqueue_take(ksiginfo_t *ksi)
302 {
303 struct ksiginfo *kp;
304 struct proc *p;
305 sigqueue_t *sq;
306
307 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL)
308 return;
309
310 p = sq->sq_proc;
311 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
312 ksi->ksi_sigq = NULL;
313 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL)
314 p->p_pendingcnt--;
315
316 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL;
317 kp = TAILQ_NEXT(kp, ksi_link)) {
318 if (kp->ksi_signo == ksi->ksi_signo)
319 break;
320 }
321 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo))
322 SIGDELSET(sq->sq_signals, ksi->ksi_signo);
323 }
324
325 int
326 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si)
327 {
328 struct proc *p = sq->sq_proc;
329 struct ksiginfo *ksi;
330 int ret = 0;
331
332 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
333
334 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) {
335 SIGADDSET(sq->sq_kill, signo);
336 goto out_set_bit;
337 }
338
339 /* directly insert the ksi, don't copy it */
340 if (si->ksi_flags & KSI_INS) {
341 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link);
342 si->ksi_sigq = sq;
343 goto out_set_bit;
344 }
345
346 if (__predict_false(ksiginfo_zone == NULL)) {
347 SIGADDSET(sq->sq_kill, signo);
348 goto out_set_bit;
349 }
350
351 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) {
352 signal_overflow++;
353 ret = EAGAIN;
354 } else if ((ksi = ksiginfo_alloc(0)) == NULL) {
355 signal_alloc_fail++;
356 ret = EAGAIN;
357 } else {
358 if (p != NULL)
359 p->p_pendingcnt++;
360 ksiginfo_copy(si, ksi);
361 ksi->ksi_signo = signo;
362 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link);
363 ksi->ksi_sigq = sq;
364 }
365
366 if ((si->ksi_flags & KSI_TRAP) != 0) {
367 if (ret != 0)
368 SIGADDSET(sq->sq_kill, signo);
369 ret = 0;
370 goto out_set_bit;
371 }
372
373 if (ret != 0)
374 return (ret);
375
376 out_set_bit:
377 SIGADDSET(sq->sq_signals, signo);
378 return (ret);
379 }
380
381 void
382 sigqueue_flush(sigqueue_t *sq)
383 {
384 struct proc *p = sq->sq_proc;
385 ksiginfo_t *ksi;
386
387 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
388
389 if (p != NULL)
390 PROC_LOCK_ASSERT(p, MA_OWNED);
391
392 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) {
393 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
394 ksi->ksi_sigq = NULL;
395 if (ksiginfo_tryfree(ksi) && p != NULL)
396 p->p_pendingcnt--;
397 }
398
399 SIGEMPTYSET(sq->sq_signals);
400 SIGEMPTYSET(sq->sq_kill);
401 }
402
403 void
404 sigqueue_collect_set(sigqueue_t *sq, sigset_t *set)
405 {
406 ksiginfo_t *ksi;
407
408 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
409
410 TAILQ_FOREACH(ksi, &sq->sq_list, ksi_link)
411 SIGADDSET(*set, ksi->ksi_signo);
412 SIGSETOR(*set, sq->sq_kill);
413 }
414
415 void
416 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, sigset_t *setp)
417 {
418 sigset_t tmp, set;
419 struct proc *p1, *p2;
420 ksiginfo_t *ksi, *next;
421
422 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited"));
423 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited"));
424 /*
425 * make a copy, this allows setp to point to src or dst
426 * sq_signals without trouble.
427 */
428 set = *setp;
429 p1 = src->sq_proc;
430 p2 = dst->sq_proc;
431 /* Move siginfo to target list */
432 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) {
433 if (SIGISMEMBER(set, ksi->ksi_signo)) {
434 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link);
435 if (p1 != NULL)
436 p1->p_pendingcnt--;
437 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link);
438 ksi->ksi_sigq = dst;
439 if (p2 != NULL)
440 p2->p_pendingcnt++;
441 }
442 }
443
444 /* Move pending bits to target list */
445 tmp = src->sq_kill;
446 SIGSETAND(tmp, set);
447 SIGSETOR(dst->sq_kill, tmp);
448 SIGSETNAND(src->sq_kill, tmp);
449
450 tmp = src->sq_signals;
451 SIGSETAND(tmp, set);
452 SIGSETOR(dst->sq_signals, tmp);
453 SIGSETNAND(src->sq_signals, tmp);
454
455 /* Finally, rescan src queue and set pending bits for it */
456 sigqueue_collect_set(src, &src->sq_signals);
457 }
458
459 void
460 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo)
461 {
462 sigset_t set;
463
464 SIGEMPTYSET(set);
465 SIGADDSET(set, signo);
466 sigqueue_move_set(src, dst, &set);
467 }
468
469 void
470 sigqueue_delete_set(sigqueue_t *sq, sigset_t *set)
471 {
472 struct proc *p = sq->sq_proc;
473 ksiginfo_t *ksi, *next;
474
475 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited"));
476
477 /* Remove siginfo queue */
478 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
479 if (SIGISMEMBER(*set, ksi->ksi_signo)) {
480 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
481 ksi->ksi_sigq = NULL;
482 if (ksiginfo_tryfree(ksi) && p != NULL)
483 p->p_pendingcnt--;
484 }
485 }
486 SIGSETNAND(sq->sq_kill, *set);
487 SIGSETNAND(sq->sq_signals, *set);
488 /* Finally, rescan queue and set pending bits for it */
489 sigqueue_collect_set(sq, &sq->sq_signals);
490 }
491
492 void
493 sigqueue_delete(sigqueue_t *sq, int signo)
494 {
495 sigset_t set;
496
497 SIGEMPTYSET(set);
498 SIGADDSET(set, signo);
499 sigqueue_delete_set(sq, &set);
500 }
501
502 /* Remove a set of signals for a process */
503 void
504 sigqueue_delete_set_proc(struct proc *p, sigset_t *set)
505 {
506 sigqueue_t worklist;
507 struct thread *td0;
508
509 PROC_LOCK_ASSERT(p, MA_OWNED);
510
511 sigqueue_init(&worklist, NULL);
512 sigqueue_move_set(&p->p_sigqueue, &worklist, set);
513
514 PROC_SLOCK(p);
515 FOREACH_THREAD_IN_PROC(p, td0)
516 sigqueue_move_set(&td0->td_sigqueue, &worklist, set);
517 PROC_SUNLOCK(p);
518
519 sigqueue_flush(&worklist);
520 }
521
522 void
523 sigqueue_delete_proc(struct proc *p, int signo)
524 {
525 sigset_t set;
526
527 SIGEMPTYSET(set);
528 SIGADDSET(set, signo);
529 sigqueue_delete_set_proc(p, &set);
530 }
531
532 void
533 sigqueue_delete_stopmask_proc(struct proc *p)
534 {
535 sigset_t set;
536
537 SIGEMPTYSET(set);
538 SIGADDSET(set, SIGSTOP);
539 SIGADDSET(set, SIGTSTP);
540 SIGADDSET(set, SIGTTIN);
541 SIGADDSET(set, SIGTTOU);
542 sigqueue_delete_set_proc(p, &set);
543 }
544
545 /*
546 * Determine signal that should be delivered to process p, the current
547 * process, 0 if none. If there is a pending stop signal with default
548 * action, the process stops in issignal().
549 */
550 int
551 cursig(struct thread *td)
552 {
553 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
554 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED);
555 THREAD_LOCK_ASSERT(td, MA_NOTOWNED);
556 return (SIGPENDING(td) ? issignal(td) : 0);
557 }
558
559 /*
560 * Arrange for ast() to handle unmasked pending signals on return to user
561 * mode. This must be called whenever a signal is added to td_sigqueue or
562 * unmasked in td_sigmask.
563 */
564 void
565 signotify(struct thread *td)
566 {
567 struct proc *p;
568 #ifdef KSE
569 sigset_t set, saved;
570 #else
571 sigset_t set;
572 #endif
573
574 p = td->td_proc;
575
576 PROC_LOCK_ASSERT(p, MA_OWNED);
577
578 /*
579 * If our mask changed we may have to move signal that were
580 * previously masked by all threads to our sigqueue.
581 */
582 set = p->p_sigqueue.sq_signals;
583 #ifdef KSE
584 if (p->p_flag & P_SA)
585 saved = p->p_sigqueue.sq_signals;
586 #endif
587 SIGSETNAND(set, td->td_sigmask);
588 if (! SIGISEMPTY(set))
589 sigqueue_move_set(&p->p_sigqueue, &td->td_sigqueue, &set);
590 if (SIGPENDING(td)) {
591 thread_lock(td);
592 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING;
593 thread_unlock(td);
594 }
595 #ifdef KSE
596 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) {
597 if (!SIGSETEQ(saved, p->p_sigqueue.sq_signals)) {
598 /* pending set changed */
599 p->p_flag |= P_SIGEVENT;
600 wakeup(&p->p_siglist);
601 }
602 }
603 #endif
604 }
605
606 int
607 sigonstack(size_t sp)
608 {
609 struct thread *td = curthread;
610
611 return ((td->td_pflags & TDP_ALTSTACK) ?
612 #if defined(COMPAT_43)
613 ((td->td_sigstk.ss_size == 0) ?
614 (td->td_sigstk.ss_flags & SS_ONSTACK) :
615 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size))
616 #else
617 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)
618 #endif
619 : 0);
620 }
621
622 static __inline int
623 sigprop(int sig)
624 {
625
626 if (sig > 0 && sig < NSIG)
627 return (sigproptbl[_SIG_IDX(sig)]);
628 return (0);
629 }
630
631 int
632 sig_ffs(sigset_t *set)
633 {
634 int i;
635
636 for (i = 0; i < _SIG_WORDS; i++)
637 if (set->__bits[i])
638 return (ffs(set->__bits[i]) + (i * 32));
639 return (0);
640 }
641
642 /*
643 * kern_sigaction
644 * sigaction
645 * freebsd4_sigaction
646 * osigaction
647 */
648 int
649 kern_sigaction(td, sig, act, oact, flags)
650 struct thread *td;
651 register int sig;
652 struct sigaction *act, *oact;
653 int flags;
654 {
655 struct sigacts *ps;
656 struct proc *p = td->td_proc;
657
658 if (!_SIG_VALID(sig))
659 return (EINVAL);
660
661 PROC_LOCK(p);
662 ps = p->p_sigacts;
663 mtx_lock(&ps->ps_mtx);
664 if (oact) {
665 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
666 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
667 oact->sa_flags = 0;
668 if (SIGISMEMBER(ps->ps_sigonstack, sig))
669 oact->sa_flags |= SA_ONSTACK;
670 if (!SIGISMEMBER(ps->ps_sigintr, sig))
671 oact->sa_flags |= SA_RESTART;
672 if (SIGISMEMBER(ps->ps_sigreset, sig))
673 oact->sa_flags |= SA_RESETHAND;
674 if (SIGISMEMBER(ps->ps_signodefer, sig))
675 oact->sa_flags |= SA_NODEFER;
676 if (SIGISMEMBER(ps->ps_siginfo, sig))
677 oact->sa_flags |= SA_SIGINFO;
678 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP)
679 oact->sa_flags |= SA_NOCLDSTOP;
680 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT)
681 oact->sa_flags |= SA_NOCLDWAIT;
682 }
683 if (act) {
684 if ((sig == SIGKILL || sig == SIGSTOP) &&
685 act->sa_handler != SIG_DFL) {
686 mtx_unlock(&ps->ps_mtx);
687 PROC_UNLOCK(p);
688 return (EINVAL);
689 }
690
691 /*
692 * Change setting atomically.
693 */
694
695 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
696 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
697 if (act->sa_flags & SA_SIGINFO) {
698 ps->ps_sigact[_SIG_IDX(sig)] =
699 (__sighandler_t *)act->sa_sigaction;
700 SIGADDSET(ps->ps_siginfo, sig);
701 } else {
702 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
703 SIGDELSET(ps->ps_siginfo, sig);
704 }
705 if (!(act->sa_flags & SA_RESTART))
706 SIGADDSET(ps->ps_sigintr, sig);
707 else
708 SIGDELSET(ps->ps_sigintr, sig);
709 if (act->sa_flags & SA_ONSTACK)
710 SIGADDSET(ps->ps_sigonstack, sig);
711 else
712 SIGDELSET(ps->ps_sigonstack, sig);
713 if (act->sa_flags & SA_RESETHAND)
714 SIGADDSET(ps->ps_sigreset, sig);
715 else
716 SIGDELSET(ps->ps_sigreset, sig);
717 if (act->sa_flags & SA_NODEFER)
718 SIGADDSET(ps->ps_signodefer, sig);
719 else
720 SIGDELSET(ps->ps_signodefer, sig);
721 if (sig == SIGCHLD) {
722 if (act->sa_flags & SA_NOCLDSTOP)
723 ps->ps_flag |= PS_NOCLDSTOP;
724 else
725 ps->ps_flag &= ~PS_NOCLDSTOP;
726 if (act->sa_flags & SA_NOCLDWAIT) {
727 /*
728 * Paranoia: since SA_NOCLDWAIT is implemented
729 * by reparenting the dying child to PID 1 (and
730 * trust it to reap the zombie), PID 1 itself
731 * is forbidden to set SA_NOCLDWAIT.
732 */
733 if (p->p_pid == 1)
734 ps->ps_flag &= ~PS_NOCLDWAIT;
735 else
736 ps->ps_flag |= PS_NOCLDWAIT;
737 } else
738 ps->ps_flag &= ~PS_NOCLDWAIT;
739 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
740 ps->ps_flag |= PS_CLDSIGIGN;
741 else
742 ps->ps_flag &= ~PS_CLDSIGIGN;
743 }
744 /*
745 * Set bit in ps_sigignore for signals that are set to SIG_IGN,
746 * and for signals set to SIG_DFL where the default is to
747 * ignore. However, don't put SIGCONT in ps_sigignore, as we
748 * have to restart the process.
749 */
750 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
751 (sigprop(sig) & SA_IGNORE &&
752 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
753 #ifdef KSE
754 if ((p->p_flag & P_SA) &&
755 SIGISMEMBER(p->p_sigqueue.sq_signals, sig)) {
756 p->p_flag |= P_SIGEVENT;
757 wakeup(&p->p_siglist);
758 }
759 #endif
760 /* never to be seen again */
761 PROC_SLOCK(p);
762 sigqueue_delete_proc(p, sig);
763 PROC_SUNLOCK(p);
764 if (sig != SIGCONT)
765 /* easier in psignal */
766 SIGADDSET(ps->ps_sigignore, sig);
767 SIGDELSET(ps->ps_sigcatch, sig);
768 } else {
769 SIGDELSET(ps->ps_sigignore, sig);
770 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
771 SIGDELSET(ps->ps_sigcatch, sig);
772 else
773 SIGADDSET(ps->ps_sigcatch, sig);
774 }
775 #ifdef COMPAT_FREEBSD4
776 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
777 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
778 (flags & KSA_FREEBSD4) == 0)
779 SIGDELSET(ps->ps_freebsd4, sig);
780 else
781 SIGADDSET(ps->ps_freebsd4, sig);
782 #endif
783 #ifdef COMPAT_43
784 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
785 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
786 (flags & KSA_OSIGSET) == 0)
787 SIGDELSET(ps->ps_osigset, sig);
788 else
789 SIGADDSET(ps->ps_osigset, sig);
790 #endif
791 }
792 mtx_unlock(&ps->ps_mtx);
793 PROC_UNLOCK(p);
794 return (0);
795 }
796
797 #ifndef _SYS_SYSPROTO_H_
798 struct sigaction_args {
799 int sig;
800 struct sigaction *act;
801 struct sigaction *oact;
802 };
803 #endif
804 int
805 sigaction(td, uap)
806 struct thread *td;
807 register struct sigaction_args *uap;
808 {
809 struct sigaction act, oact;
810 register struct sigaction *actp, *oactp;
811 int error;
812
813 actp = (uap->act != NULL) ? &act : NULL;
814 oactp = (uap->oact != NULL) ? &oact : NULL;
815 if (actp) {
816 error = copyin(uap->act, actp, sizeof(act));
817 if (error)
818 return (error);
819 }
820 error = kern_sigaction(td, uap->sig, actp, oactp, 0);
821 if (oactp && !error)
822 error = copyout(oactp, uap->oact, sizeof(oact));
823 return (error);
824 }
825
826 #ifdef COMPAT_FREEBSD4
827 #ifndef _SYS_SYSPROTO_H_
828 struct freebsd4_sigaction_args {
829 int sig;
830 struct sigaction *act;
831 struct sigaction *oact;
832 };
833 #endif
834 int
835 freebsd4_sigaction(td, uap)
836 struct thread *td;
837 register struct freebsd4_sigaction_args *uap;
838 {
839 struct sigaction act, oact;
840 register struct sigaction *actp, *oactp;
841 int error;
842
843
844 actp = (uap->act != NULL) ? &act : NULL;
845 oactp = (uap->oact != NULL) ? &oact : NULL;
846 if (actp) {
847 error = copyin(uap->act, actp, sizeof(act));
848 if (error)
849 return (error);
850 }
851 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4);
852 if (oactp && !error)
853 error = copyout(oactp, uap->oact, sizeof(oact));
854 return (error);
855 }
856 #endif /* COMAPT_FREEBSD4 */
857
858 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
859 #ifndef _SYS_SYSPROTO_H_
860 struct osigaction_args {
861 int signum;
862 struct osigaction *nsa;
863 struct osigaction *osa;
864 };
865 #endif
866 int
867 osigaction(td, uap)
868 struct thread *td;
869 register struct osigaction_args *uap;
870 {
871 struct osigaction sa;
872 struct sigaction nsa, osa;
873 register struct sigaction *nsap, *osap;
874 int error;
875
876 if (uap->signum <= 0 || uap->signum >= ONSIG)
877 return (EINVAL);
878
879 nsap = (uap->nsa != NULL) ? &nsa : NULL;
880 osap = (uap->osa != NULL) ? &osa : NULL;
881
882 if (nsap) {
883 error = copyin(uap->nsa, &sa, sizeof(sa));
884 if (error)
885 return (error);
886 nsap->sa_handler = sa.sa_handler;
887 nsap->sa_flags = sa.sa_flags;
888 OSIG2SIG(sa.sa_mask, nsap->sa_mask);
889 }
890 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
891 if (osap && !error) {
892 sa.sa_handler = osap->sa_handler;
893 sa.sa_flags = osap->sa_flags;
894 SIG2OSIG(osap->sa_mask, sa.sa_mask);
895 error = copyout(&sa, uap->osa, sizeof(sa));
896 }
897 return (error);
898 }
899
900 #if !defined(__i386__)
901 /* Avoid replicating the same stub everywhere */
902 int
903 osigreturn(td, uap)
904 struct thread *td;
905 struct osigreturn_args *uap;
906 {
907
908 return (nosys(td, (struct nosys_args *)uap));
909 }
910 #endif
911 #endif /* COMPAT_43 */
912
913 /*
914 * Initialize signal state for process 0;
915 * set to ignore signals that are ignored by default.
916 */
917 void
918 siginit(p)
919 struct proc *p;
920 {
921 register int i;
922 struct sigacts *ps;
923
924 PROC_LOCK(p);
925 ps = p->p_sigacts;
926 mtx_lock(&ps->ps_mtx);
927 for (i = 1; i <= NSIG; i++)
928 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
929 SIGADDSET(ps->ps_sigignore, i);
930 mtx_unlock(&ps->ps_mtx);
931 PROC_UNLOCK(p);
932 }
933
934 /*
935 * Reset signals for an exec of the specified process.
936 */
937 void
938 execsigs(struct proc *p)
939 {
940 struct sigacts *ps;
941 int sig;
942 struct thread *td;
943
944 /*
945 * Reset caught signals. Held signals remain held
946 * through td_sigmask (unless they were caught,
947 * and are now ignored by default).
948 */
949 PROC_LOCK_ASSERT(p, MA_OWNED);
950 td = FIRST_THREAD_IN_PROC(p);
951 ps = p->p_sigacts;
952 mtx_lock(&ps->ps_mtx);
953 while (SIGNOTEMPTY(ps->ps_sigcatch)) {
954 sig = sig_ffs(&ps->ps_sigcatch);
955 SIGDELSET(ps->ps_sigcatch, sig);
956 if (sigprop(sig) & SA_IGNORE) {
957 if (sig != SIGCONT)
958 SIGADDSET(ps->ps_sigignore, sig);
959 PROC_SLOCK(p);
960 sigqueue_delete_proc(p, sig);
961 PROC_SUNLOCK(p);
962 }
963 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
964 }
965 /*
966 * Reset stack state to the user stack.
967 * Clear set of signals caught on the signal stack.
968 */
969 td->td_sigstk.ss_flags = SS_DISABLE;
970 td->td_sigstk.ss_size = 0;
971 td->td_sigstk.ss_sp = 0;
972 td->td_pflags &= ~TDP_ALTSTACK;
973 /*
974 * Reset no zombies if child dies flag as Solaris does.
975 */
976 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN);
977 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
978 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL;
979 mtx_unlock(&ps->ps_mtx);
980 }
981
982 /*
983 * kern_sigprocmask()
984 *
985 * Manipulate signal mask.
986 */
987 int
988 kern_sigprocmask(td, how, set, oset, old)
989 struct thread *td;
990 int how;
991 sigset_t *set, *oset;
992 int old;
993 {
994 int error;
995
996 PROC_LOCK(td->td_proc);
997 if (oset != NULL)
998 *oset = td->td_sigmask;
999
1000 error = 0;
1001 if (set != NULL) {
1002 switch (how) {
1003 case SIG_BLOCK:
1004 SIG_CANTMASK(*set);
1005 SIGSETOR(td->td_sigmask, *set);
1006 break;
1007 case SIG_UNBLOCK:
1008 SIGSETNAND(td->td_sigmask, *set);
1009 signotify(td);
1010 break;
1011 case SIG_SETMASK:
1012 SIG_CANTMASK(*set);
1013 if (old)
1014 SIGSETLO(td->td_sigmask, *set);
1015 else
1016 td->td_sigmask = *set;
1017 signotify(td);
1018 break;
1019 default:
1020 error = EINVAL;
1021 break;
1022 }
1023 }
1024 PROC_UNLOCK(td->td_proc);
1025 return (error);
1026 }
1027
1028 #ifndef _SYS_SYSPROTO_H_
1029 struct sigprocmask_args {
1030 int how;
1031 const sigset_t *set;
1032 sigset_t *oset;
1033 };
1034 #endif
1035 int
1036 sigprocmask(td, uap)
1037 register struct thread *td;
1038 struct sigprocmask_args *uap;
1039 {
1040 sigset_t set, oset;
1041 sigset_t *setp, *osetp;
1042 int error;
1043
1044 setp = (uap->set != NULL) ? &set : NULL;
1045 osetp = (uap->oset != NULL) ? &oset : NULL;
1046 if (setp) {
1047 error = copyin(uap->set, setp, sizeof(set));
1048 if (error)
1049 return (error);
1050 }
1051 error = kern_sigprocmask(td, uap->how, setp, osetp, 0);
1052 if (osetp && !error) {
1053 error = copyout(osetp, uap->oset, sizeof(oset));
1054 }
1055 return (error);
1056 }
1057
1058 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1059 #ifndef _SYS_SYSPROTO_H_
1060 struct osigprocmask_args {
1061 int how;
1062 osigset_t mask;
1063 };
1064 #endif
1065 int
1066 osigprocmask(td, uap)
1067 register struct thread *td;
1068 struct osigprocmask_args *uap;
1069 {
1070 sigset_t set, oset;
1071 int error;
1072
1073 OSIG2SIG(uap->mask, set);
1074 error = kern_sigprocmask(td, uap->how, &set, &oset, 1);
1075 SIG2OSIG(oset, td->td_retval[0]);
1076 return (error);
1077 }
1078 #endif /* COMPAT_43 */
1079
1080 int
1081 sigwait(struct thread *td, struct sigwait_args *uap)
1082 {
1083 ksiginfo_t ksi;
1084 sigset_t set;
1085 int error;
1086
1087 error = copyin(uap->set, &set, sizeof(set));
1088 if (error) {
1089 td->td_retval[0] = error;
1090 return (0);
1091 }
1092
1093 error = kern_sigtimedwait(td, set, &ksi, NULL);
1094 if (error) {
1095 if (error == ERESTART)
1096 return (error);
1097 td->td_retval[0] = error;
1098 return (0);
1099 }
1100
1101 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo));
1102 td->td_retval[0] = error;
1103 return (0);
1104 }
1105
1106 int
1107 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap)
1108 {
1109 struct timespec ts;
1110 struct timespec *timeout;
1111 sigset_t set;
1112 ksiginfo_t ksi;
1113 int error;
1114
1115 if (uap->timeout) {
1116 error = copyin(uap->timeout, &ts, sizeof(ts));
1117 if (error)
1118 return (error);
1119
1120 timeout = &ts;
1121 } else
1122 timeout = NULL;
1123
1124 error = copyin(uap->set, &set, sizeof(set));
1125 if (error)
1126 return (error);
1127
1128 error = kern_sigtimedwait(td, set, &ksi, timeout);
1129 if (error)
1130 return (error);
1131
1132 if (uap->info)
1133 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t));
1134
1135 if (error == 0)
1136 td->td_retval[0] = ksi.ksi_signo;
1137 return (error);
1138 }
1139
1140 int
1141 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap)
1142 {
1143 ksiginfo_t ksi;
1144 sigset_t set;
1145 int error;
1146
1147 error = copyin(uap->set, &set, sizeof(set));
1148 if (error)
1149 return (error);
1150
1151 error = kern_sigtimedwait(td, set, &ksi, NULL);
1152 if (error)
1153 return (error);
1154
1155 if (uap->info)
1156 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t));
1157
1158 if (error == 0)
1159 td->td_retval[0] = ksi.ksi_signo;
1160 return (error);
1161 }
1162
1163 int
1164 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi,
1165 struct timespec *timeout)
1166 {
1167 struct sigacts *ps;
1168 sigset_t savedmask;
1169 struct proc *p;
1170 int error, sig, hz, i, timevalid = 0;
1171 struct timespec rts, ets, ts;
1172 struct timeval tv;
1173
1174 p = td->td_proc;
1175 error = 0;
1176 sig = 0;
1177 ets.tv_sec = 0;
1178 ets.tv_nsec = 0;
1179 SIG_CANTMASK(waitset);
1180
1181 PROC_LOCK(p);
1182 ps = p->p_sigacts;
1183 savedmask = td->td_sigmask;
1184 if (timeout) {
1185 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) {
1186 timevalid = 1;
1187 getnanouptime(&rts);
1188 ets = rts;
1189 timespecadd(&ets, timeout);
1190 }
1191 }
1192
1193 restart:
1194 for (i = 1; i <= _SIG_MAXSIG; ++i) {
1195 if (!SIGISMEMBER(waitset, i))
1196 continue;
1197 if (!SIGISMEMBER(td->td_sigqueue.sq_signals, i)) {
1198 if (SIGISMEMBER(p->p_sigqueue.sq_signals, i)) {
1199 #ifdef KSE
1200 if (p->p_flag & P_SA) {
1201 p->p_flag |= P_SIGEVENT;
1202 wakeup(&p->p_siglist);
1203 }
1204 #endif
1205 sigqueue_move(&p->p_sigqueue,
1206 &td->td_sigqueue, i);
1207 } else
1208 continue;
1209 }
1210
1211 SIGFILLSET(td->td_sigmask);
1212 SIG_CANTMASK(td->td_sigmask);
1213 SIGDELSET(td->td_sigmask, i);
1214 mtx_lock(&ps->ps_mtx);
1215 sig = cursig(td);
1216 mtx_unlock(&ps->ps_mtx);
1217 if (sig)
1218 goto out;
1219 else {
1220 /*
1221 * Because cursig() may have stopped current thread,
1222 * after it is resumed, things may have already been
1223 * changed, it should rescan any pending signals.
1224 */
1225 goto restart;
1226 }
1227 }
1228
1229 if (error)
1230 goto out;
1231
1232 /*
1233 * POSIX says this must be checked after looking for pending
1234 * signals.
1235 */
1236 if (timeout) {
1237 if (!timevalid) {
1238 error = EINVAL;
1239 goto out;
1240 }
1241 getnanouptime(&rts);
1242 if (timespeccmp(&rts, &ets, >=)) {
1243 error = EAGAIN;
1244 goto out;
1245 }
1246 ts = ets;
1247 timespecsub(&ts, &rts);
1248 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1249 hz = tvtohz(&tv);
1250 } else
1251 hz = 0;
1252
1253 td->td_sigmask = savedmask;
1254 SIGSETNAND(td->td_sigmask, waitset);
1255 signotify(td);
1256 error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz);
1257 if (timeout) {
1258 if (error == ERESTART) {
1259 /* timeout can not be restarted. */
1260 error = EINTR;
1261 } else if (error == EAGAIN) {
1262 /* will calculate timeout by ourself. */
1263 error = 0;
1264 }
1265 }
1266 goto restart;
1267
1268 out:
1269 td->td_sigmask = savedmask;
1270 signotify(td);
1271 if (sig) {
1272 ksiginfo_init(ksi);
1273 sigqueue_get(&td->td_sigqueue, sig, ksi);
1274 ksi->ksi_signo = sig;
1275 if (ksi->ksi_code == SI_TIMER)
1276 itimer_accept(p, ksi->ksi_timerid, ksi);
1277 error = 0;
1278
1279 #ifdef KTRACE
1280 if (KTRPOINT(td, KTR_PSIG)) {
1281 sig_t action;
1282
1283 mtx_lock(&ps->ps_mtx);
1284 action = ps->ps_sigact[_SIG_IDX(sig)];
1285 mtx_unlock(&ps->ps_mtx);
1286 ktrpsig(sig, action, &td->td_sigmask, 0);
1287 }
1288 #endif
1289 if (sig == SIGKILL)
1290 sigexit(td, sig);
1291 }
1292 PROC_UNLOCK(p);
1293 return (error);
1294 }
1295
1296 #ifndef _SYS_SYSPROTO_H_
1297 struct sigpending_args {
1298 sigset_t *set;
1299 };
1300 #endif
1301 int
1302 sigpending(td, uap)
1303 struct thread *td;
1304 struct sigpending_args *uap;
1305 {
1306 struct proc *p = td->td_proc;
1307 sigset_t pending;
1308
1309 PROC_LOCK(p);
1310 pending = p->p_sigqueue.sq_signals;
1311 SIGSETOR(pending, td->td_sigqueue.sq_signals);
1312 PROC_UNLOCK(p);
1313 return (copyout(&pending, uap->set, sizeof(sigset_t)));
1314 }
1315
1316 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1317 #ifndef _SYS_SYSPROTO_H_
1318 struct osigpending_args {
1319 int dummy;
1320 };
1321 #endif
1322 int
1323 osigpending(td, uap)
1324 struct thread *td;
1325 struct osigpending_args *uap;
1326 {
1327 struct proc *p = td->td_proc;
1328 sigset_t pending;
1329
1330 PROC_LOCK(p);
1331 pending = p->p_sigqueue.sq_signals;
1332 SIGSETOR(pending, td->td_sigqueue.sq_signals);
1333 PROC_UNLOCK(p);
1334 SIG2OSIG(pending, td->td_retval[0]);
1335 return (0);
1336 }
1337 #endif /* COMPAT_43 */
1338
1339 #if defined(COMPAT_43)
1340 /*
1341 * Generalized interface signal handler, 4.3-compatible.
1342 */
1343 #ifndef _SYS_SYSPROTO_H_
1344 struct osigvec_args {
1345 int signum;
1346 struct sigvec *nsv;
1347 struct sigvec *osv;
1348 };
1349 #endif
1350 /* ARGSUSED */
1351 int
1352 osigvec(td, uap)
1353 struct thread *td;
1354 register struct osigvec_args *uap;
1355 {
1356 struct sigvec vec;
1357 struct sigaction nsa, osa;
1358 register struct sigaction *nsap, *osap;
1359 int error;
1360
1361 if (uap->signum <= 0 || uap->signum >= ONSIG)
1362 return (EINVAL);
1363 nsap = (uap->nsv != NULL) ? &nsa : NULL;
1364 osap = (uap->osv != NULL) ? &osa : NULL;
1365 if (nsap) {
1366 error = copyin(uap->nsv, &vec, sizeof(vec));
1367 if (error)
1368 return (error);
1369 nsap->sa_handler = vec.sv_handler;
1370 OSIG2SIG(vec.sv_mask, nsap->sa_mask);
1371 nsap->sa_flags = vec.sv_flags;
1372 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */
1373 }
1374 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
1375 if (osap && !error) {
1376 vec.sv_handler = osap->sa_handler;
1377 SIG2OSIG(osap->sa_mask, vec.sv_mask);
1378 vec.sv_flags = osap->sa_flags;
1379 vec.sv_flags &= ~SA_NOCLDWAIT;
1380 vec.sv_flags ^= SA_RESTART;
1381 error = copyout(&vec, uap->osv, sizeof(vec));
1382 }
1383 return (error);
1384 }
1385
1386 #ifndef _SYS_SYSPROTO_H_
1387 struct osigblock_args {
1388 int mask;
1389 };
1390 #endif
1391 int
1392 osigblock(td, uap)
1393 register struct thread *td;
1394 struct osigblock_args *uap;
1395 {
1396 struct proc *p = td->td_proc;
1397 sigset_t set;
1398
1399 OSIG2SIG(uap->mask, set);
1400 SIG_CANTMASK(set);
1401 PROC_LOCK(p);
1402 SIG2OSIG(td->td_sigmask, td->td_retval[0]);
1403 SIGSETOR(td->td_sigmask, set);
1404 PROC_UNLOCK(p);
1405 return (0);
1406 }
1407
1408 #ifndef _SYS_SYSPROTO_H_
1409 struct osigsetmask_args {
1410 int mask;
1411 };
1412 #endif
1413 int
1414 osigsetmask(td, uap)
1415 struct thread *td;
1416 struct osigsetmask_args *uap;
1417 {
1418 struct proc *p = td->td_proc;
1419 sigset_t set;
1420
1421 OSIG2SIG(uap->mask, set);
1422 SIG_CANTMASK(set);
1423 PROC_LOCK(p);
1424 SIG2OSIG(td->td_sigmask, td->td_retval[0]);
1425 SIGSETLO(td->td_sigmask, set);
1426 signotify(td);
1427 PROC_UNLOCK(p);
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
1461 /*
1462 * When returning from sigsuspend, we want
1463 * the old mask to be restored after the
1464 * signal handler has finished. Thus, we
1465 * save it here and mark the sigacts structure
1466 * to indicate this.
1467 */
1468 PROC_LOCK(p);
1469 td->td_oldsigmask = td->td_sigmask;
1470 td->td_pflags |= TDP_OLDMASK;
1471 SIG_CANTMASK(mask);
1472 td->td_sigmask = mask;
1473 signotify(td);
1474 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0)
1475 /* void */;
1476 PROC_UNLOCK(p);
1477 /* always return EINTR rather than ERESTART... */
1478 return (EINTR);
1479 }
1480
1481 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1482 /*
1483 * Compatibility sigsuspend call for old binaries. Note nonstandard calling
1484 * convention: libc stub passes mask, not pointer, to save a copyin.
1485 */
1486 #ifndef _SYS_SYSPROTO_H_
1487 struct osigsuspend_args {
1488 osigset_t mask;
1489 };
1490 #endif
1491 /* ARGSUSED */
1492 int
1493 osigsuspend(td, uap)
1494 struct thread *td;
1495 struct osigsuspend_args *uap;
1496 {
1497 struct proc *p = td->td_proc;
1498 sigset_t mask;
1499
1500 PROC_LOCK(p);
1501 td->td_oldsigmask = td->td_sigmask;
1502 td->td_pflags |= TDP_OLDMASK;
1503 OSIG2SIG(uap->mask, mask);
1504 SIG_CANTMASK(mask);
1505 SIGSETLO(td->td_sigmask, mask);
1506 signotify(td);
1507 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0)
1508 /* void */;
1509 PROC_UNLOCK(p);
1510 /* always return EINTR rather than ERESTART... */
1511 return (EINTR);
1512 }
1513 #endif /* COMPAT_43 */
1514
1515 #if defined(COMPAT_43)
1516 #ifndef _SYS_SYSPROTO_H_
1517 struct osigstack_args {
1518 struct sigstack *nss;
1519 struct sigstack *oss;
1520 };
1521 #endif
1522 /* ARGSUSED */
1523 int
1524 osigstack(td, uap)
1525 struct thread *td;
1526 register struct osigstack_args *uap;
1527 {
1528 struct sigstack nss, oss;
1529 int error = 0;
1530
1531 if (uap->nss != NULL) {
1532 error = copyin(uap->nss, &nss, sizeof(nss));
1533 if (error)
1534 return (error);
1535 }
1536 oss.ss_sp = td->td_sigstk.ss_sp;
1537 oss.ss_onstack = sigonstack(cpu_getstack(td));
1538 if (uap->nss != NULL) {
1539 td->td_sigstk.ss_sp = nss.ss_sp;
1540 td->td_sigstk.ss_size = 0;
1541 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK;
1542 td->td_pflags |= TDP_ALTSTACK;
1543 }
1544 if (uap->oss != NULL)
1545 error = copyout(&oss, uap->oss, sizeof(oss));
1546
1547 return (error);
1548 }
1549 #endif /* COMPAT_43 */
1550
1551 #ifndef _SYS_SYSPROTO_H_
1552 struct sigaltstack_args {
1553 stack_t *ss;
1554 stack_t *oss;
1555 };
1556 #endif
1557 /* ARGSUSED */
1558 int
1559 sigaltstack(td, uap)
1560 struct thread *td;
1561 register struct sigaltstack_args *uap;
1562 {
1563 stack_t ss, oss;
1564 int error;
1565
1566 if (uap->ss != NULL) {
1567 error = copyin(uap->ss, &ss, sizeof(ss));
1568 if (error)
1569 return (error);
1570 }
1571 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL,
1572 (uap->oss != NULL) ? &oss : NULL);
1573 if (error)
1574 return (error);
1575 if (uap->oss != NULL)
1576 error = copyout(&oss, uap->oss, sizeof(stack_t));
1577 return (error);
1578 }
1579
1580 int
1581 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss)
1582 {
1583 struct proc *p = td->td_proc;
1584 int oonstack;
1585
1586 oonstack = sigonstack(cpu_getstack(td));
1587
1588 if (oss != NULL) {
1589 *oss = td->td_sigstk;
1590 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK)
1591 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
1592 }
1593
1594 if (ss != NULL) {
1595 if (oonstack)
1596 return (EPERM);
1597 if ((ss->ss_flags & ~SS_DISABLE) != 0)
1598 return (EINVAL);
1599 if (!(ss->ss_flags & SS_DISABLE)) {
1600 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
1601 return (ENOMEM);
1602
1603 td->td_sigstk = *ss;
1604 td->td_pflags |= TDP_ALTSTACK;
1605 } else {
1606 td->td_pflags &= ~TDP_ALTSTACK;
1607 }
1608 }
1609 return (0);
1610 }
1611
1612 /*
1613 * Common code for kill process group/broadcast kill.
1614 * cp is calling process.
1615 */
1616 static int
1617 killpg1(td, sig, pgid, all)
1618 register struct thread *td;
1619 int sig, pgid, all;
1620 {
1621 register struct proc *p;
1622 struct pgrp *pgrp;
1623 int nfound = 0;
1624
1625 if (all) {
1626 /*
1627 * broadcast
1628 */
1629 sx_slock(&allproc_lock);
1630 FOREACH_PROC_IN_SYSTEM(p) {
1631 PROC_LOCK(p);
1632 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
1633 p == td->td_proc || p->p_state == PRS_NEW) {
1634 PROC_UNLOCK(p);
1635 continue;
1636 }
1637 if (p_cansignal(td, p, sig) == 0) {
1638 nfound++;
1639 if (sig)
1640 psignal(p, sig);
1641 }
1642 PROC_UNLOCK(p);
1643 }
1644 sx_sunlock(&allproc_lock);
1645 } else {
1646 sx_slock(&proctree_lock);
1647 if (pgid == 0) {
1648 /*
1649 * zero pgid means send to my process group.
1650 */
1651 pgrp = td->td_proc->p_pgrp;
1652 PGRP_LOCK(pgrp);
1653 } else {
1654 pgrp = pgfind(pgid);
1655 if (pgrp == NULL) {
1656 sx_sunlock(&proctree_lock);
1657 return (ESRCH);
1658 }
1659 }
1660 sx_sunlock(&proctree_lock);
1661 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
1662 PROC_LOCK(p);
1663 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
1664 p->p_state == PRS_NEW ) {
1665 PROC_UNLOCK(p);
1666 continue;
1667 }
1668 if (p_cansignal(td, p, sig) == 0) {
1669 nfound++;
1670 if (sig)
1671 psignal(p, sig);
1672 }
1673 PROC_UNLOCK(p);
1674 }
1675 PGRP_UNLOCK(pgrp);
1676 }
1677 return (nfound ? 0 : ESRCH);
1678 }
1679
1680 #ifndef _SYS_SYSPROTO_H_
1681 struct kill_args {
1682 int pid;
1683 int signum;
1684 };
1685 #endif
1686 /* ARGSUSED */
1687 int
1688 kill(td, uap)
1689 register struct thread *td;
1690 register struct kill_args *uap;
1691 {
1692 register struct proc *p;
1693 int error;
1694
1695 AUDIT_ARG(signum, uap->signum);
1696 AUDIT_ARG(pid, uap->pid);
1697 if ((u_int)uap->signum > _SIG_MAXSIG)
1698 return (EINVAL);
1699
1700 if (uap->pid > 0) {
1701 /* kill single process */
1702 if ((p = pfind(uap->pid)) == NULL) {
1703 if ((p = zpfind(uap->pid)) == NULL)
1704 return (ESRCH);
1705 }
1706 AUDIT_ARG(process, p);
1707 error = p_cansignal(td, p, uap->signum);
1708 if (error == 0 && uap->signum)
1709 psignal(p, uap->signum);
1710 PROC_UNLOCK(p);
1711 return (error);
1712 }
1713 switch (uap->pid) {
1714 case -1: /* broadcast signal */
1715 return (killpg1(td, uap->signum, 0, 1));
1716 case 0: /* signal own process group */
1717 return (killpg1(td, uap->signum, 0, 0));
1718 default: /* negative explicit process group */
1719 return (killpg1(td, uap->signum, -uap->pid, 0));
1720 }
1721 /* NOTREACHED */
1722 }
1723
1724 #if defined(COMPAT_43)
1725 #ifndef _SYS_SYSPROTO_H_
1726 struct okillpg_args {
1727 int pgid;
1728 int signum;
1729 };
1730 #endif
1731 /* ARGSUSED */
1732 int
1733 okillpg(td, uap)
1734 struct thread *td;
1735 register struct okillpg_args *uap;
1736 {
1737
1738 AUDIT_ARG(signum, uap->signum);
1739 AUDIT_ARG(pid, uap->pgid);
1740 if ((u_int)uap->signum > _SIG_MAXSIG)
1741 return (EINVAL);
1742
1743 return (killpg1(td, uap->signum, uap->pgid, 0));
1744 }
1745 #endif /* COMPAT_43 */
1746
1747 #ifndef _SYS_SYSPROTO_H_
1748 struct sigqueue_args {
1749 pid_t pid;
1750 int signum;
1751 /* union sigval */ void *value;
1752 };
1753 #endif
1754 int
1755 sigqueue(struct thread *td, struct sigqueue_args *uap)
1756 {
1757 ksiginfo_t ksi;
1758 struct proc *p;
1759 int error;
1760
1761 if ((u_int)uap->signum > _SIG_MAXSIG)
1762 return (EINVAL);
1763
1764 /*
1765 * Specification says sigqueue can only send signal to
1766 * single process.
1767 */
1768 if (uap->pid <= 0)
1769 return (EINVAL);
1770
1771 if ((p = pfind(uap->pid)) == NULL) {
1772 if ((p = zpfind(uap->pid)) == NULL)
1773 return (ESRCH);
1774 }
1775 error = p_cansignal(td, p, uap->signum);
1776 if (error == 0 && uap->signum != 0) {
1777 ksiginfo_init(&ksi);
1778 ksi.ksi_signo = uap->signum;
1779 ksi.ksi_code = SI_QUEUE;
1780 ksi.ksi_pid = td->td_proc->p_pid;
1781 ksi.ksi_uid = td->td_ucred->cr_ruid;
1782 ksi.ksi_value.sival_ptr = uap->value;
1783 error = tdsignal(p, NULL, ksi.ksi_signo, &ksi);
1784 }
1785 PROC_UNLOCK(p);
1786 return (error);
1787 }
1788
1789 /*
1790 * Send a signal to a process group.
1791 */
1792 void
1793 gsignal(pgid, sig)
1794 int pgid, sig;
1795 {
1796 struct pgrp *pgrp;
1797
1798 if (pgid != 0) {
1799 sx_slock(&proctree_lock);
1800 pgrp = pgfind(pgid);
1801 sx_sunlock(&proctree_lock);
1802 if (pgrp != NULL) {
1803 pgsignal(pgrp, sig, 0);
1804 PGRP_UNLOCK(pgrp);
1805 }
1806 }
1807 }
1808
1809 /*
1810 * Send a signal to a process group. If checktty is 1,
1811 * limit to members which have a controlling terminal.
1812 */
1813 void
1814 pgsignal(pgrp, sig, checkctty)
1815 struct pgrp *pgrp;
1816 int sig, checkctty;
1817 {
1818 register struct proc *p;
1819
1820 if (pgrp) {
1821 PGRP_LOCK_ASSERT(pgrp, MA_OWNED);
1822 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
1823 PROC_LOCK(p);
1824 if (checkctty == 0 || p->p_flag & P_CONTROLT)
1825 psignal(p, sig);
1826 PROC_UNLOCK(p);
1827 }
1828 }
1829 }
1830
1831 /*
1832 * Send a signal caused by a trap to the current thread. If it will be
1833 * caught immediately, deliver it with correct code. Otherwise, post it
1834 * normally.
1835 */
1836 void
1837 trapsignal(struct thread *td, ksiginfo_t *ksi)
1838 {
1839 struct sigacts *ps;
1840 struct proc *p;
1841 #ifdef KSE
1842 int error;
1843 #endif
1844 int sig;
1845 int code;
1846
1847 p = td->td_proc;
1848 sig = ksi->ksi_signo;
1849 code = ksi->ksi_code;
1850 KASSERT(_SIG_VALID(sig), ("invalid signal"));
1851
1852 #ifdef KSE
1853 if (td->td_pflags & TDP_SA) {
1854 if (td->td_mailbox == NULL)
1855 thread_user_enter(td);
1856 PROC_LOCK(p);
1857 SIGDELSET(td->td_sigmask, sig);
1858 thread_lock(td);
1859 /*
1860 * Force scheduling an upcall, so UTS has chance to
1861 * process the signal before thread runs again in
1862 * userland.
1863 */
1864 if (td->td_upcall)
1865 td->td_upcall->ku_flags |= KUF_DOUPCALL;
1866 thread_unlock(td);
1867 } else {
1868 PROC_LOCK(p);
1869 }
1870 #else
1871 PROC_LOCK(p);
1872 #endif
1873 ps = p->p_sigacts;
1874 mtx_lock(&ps->ps_mtx);
1875 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) &&
1876 !SIGISMEMBER(td->td_sigmask, sig)) {
1877 td->td_ru.ru_nsignals++;
1878 #ifdef KTRACE
1879 if (KTRPOINT(curthread, KTR_PSIG))
1880 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)],
1881 &td->td_sigmask, code);
1882 #endif
1883 #ifdef KSE
1884 if (!(td->td_pflags & TDP_SA))
1885 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)],
1886 ksi, &td->td_sigmask);
1887 #else
1888 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)],
1889 ksi, &td->td_sigmask);
1890 #endif
1891 #ifdef KSE
1892 else if (td->td_mailbox == NULL) {
1893 mtx_unlock(&ps->ps_mtx);
1894 /* UTS caused a sync signal */
1895 p->p_code = code; /* XXX for core dump/debugger */
1896 p->p_sig = sig; /* XXX to verify code */
1897 sigexit(td, sig);
1898 } else {
1899 mtx_unlock(&ps->ps_mtx);
1900 SIGADDSET(td->td_sigmask, sig);
1901 PROC_UNLOCK(p);
1902 error = copyout(&ksi->ksi_info, &td->td_mailbox->tm_syncsig,
1903 sizeof(siginfo_t));
1904 PROC_LOCK(p);
1905 /* UTS memory corrupted */
1906 if (error)
1907 sigexit(td, SIGSEGV);
1908 mtx_lock(&ps->ps_mtx);
1909 }
1910 #endif
1911 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
1912 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1913 SIGADDSET(td->td_sigmask, sig);
1914 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
1915 /*
1916 * See kern_sigaction() for origin of this code.
1917 */
1918 SIGDELSET(ps->ps_sigcatch, sig);
1919 if (sig != SIGCONT &&
1920 sigprop(sig) & SA_IGNORE)
1921 SIGADDSET(ps->ps_sigignore, sig);
1922 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1923 }
1924 mtx_unlock(&ps->ps_mtx);
1925 } else {
1926 /*
1927 * Avoid a possible infinite loop if the thread
1928 * masking the signal or process is ignoring the
1929 * signal.
1930 */
1931 if (kern_forcesigexit &&
1932 (SIGISMEMBER(td->td_sigmask, sig) ||
1933 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) {
1934 SIGDELSET(td->td_sigmask, sig);
1935 SIGDELSET(ps->ps_sigcatch, sig);
1936 SIGDELSET(ps->ps_sigignore, sig);
1937 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1938 }
1939 mtx_unlock(&ps->ps_mtx);
1940 p->p_code = code; /* XXX for core dump/debugger */
1941 p->p_sig = sig; /* XXX to verify code */
1942 tdsignal(p, td, sig, ksi);
1943 }
1944 PROC_UNLOCK(p);
1945 }
1946
1947 static struct thread *
1948 sigtd(struct proc *p, int sig, int prop)
1949 {
1950 struct thread *td, *signal_td;
1951
1952 PROC_LOCK_ASSERT(p, MA_OWNED);
1953
1954 /*
1955 * Check if current thread can handle the signal without
1956 * switching conetxt to another thread.
1957 */
1958 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig))
1959 return (curthread);
1960 signal_td = NULL;
1961 PROC_SLOCK(p);
1962 FOREACH_THREAD_IN_PROC(p, td) {
1963 if (!SIGISMEMBER(td->td_sigmask, sig)) {
1964 signal_td = td;
1965 break;
1966 }
1967 }
1968 if (signal_td == NULL)
1969 signal_td = FIRST_THREAD_IN_PROC(p);
1970 PROC_SUNLOCK(p);
1971 return (signal_td);
1972 }
1973
1974 /*
1975 * Send the signal to the process. If the signal has an action, the action
1976 * is usually performed by the target process rather than the caller; we add
1977 * the signal to the set of pending signals for the process.
1978 *
1979 * Exceptions:
1980 * o When a stop signal is sent to a sleeping process that takes the
1981 * default action, the process is stopped without awakening it.
1982 * o SIGCONT restarts stopped processes (or puts them back to sleep)
1983 * regardless of the signal action (eg, blocked or ignored).
1984 *
1985 * Other ignored signals are discarded immediately.
1986 *
1987 * NB: This function may be entered from the debugger via the "kill" DDB
1988 * command. There is little that can be done to mitigate the possibly messy
1989 * side effects of this unwise possibility.
1990 */
1991 void
1992 psignal(struct proc *p, int sig)
1993 {
1994 (void) tdsignal(p, NULL, sig, NULL);
1995 }
1996
1997 int
1998 psignal_event(struct proc *p, struct sigevent *sigev, ksiginfo_t *ksi)
1999 {
2000 struct thread *td = NULL;
2001
2002 PROC_LOCK_ASSERT(p, MA_OWNED);
2003
2004 KASSERT(!KSI_ONQ(ksi), ("psignal_event: ksi on queue"));
2005
2006 /*
2007 * ksi_code and other fields should be set before
2008 * calling this function.
2009 */
2010 ksi->ksi_signo = sigev->sigev_signo;
2011 ksi->ksi_value = sigev->sigev_value;
2012 if (sigev->sigev_notify == SIGEV_THREAD_ID) {
2013 td = thread_find(p, sigev->sigev_notify_thread_id);
2014 if (td == NULL)
2015 return (ESRCH);
2016 }
2017 return (tdsignal(p, td, ksi->ksi_signo, ksi));
2018 }
2019
2020 int
2021 tdsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi)
2022 {
2023 #ifdef KSE
2024 sigset_t saved;
2025 int ret;
2026
2027 if (p->p_flag & P_SA)
2028 saved = p->p_sigqueue.sq_signals;
2029 ret = do_tdsignal(p, td, sig, ksi);
2030 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) {
2031 if (!SIGSETEQ(saved, p->p_sigqueue.sq_signals)) {
2032 /* pending set changed */
2033 p->p_flag |= P_SIGEVENT;
2034 wakeup(&p->p_siglist);
2035 }
2036 }
2037 return (ret);
2038 }
2039
2040 static int
2041 do_tdsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi)
2042 {
2043 #endif
2044 sig_t action;
2045 sigqueue_t *sigqueue;
2046 int prop;
2047 struct sigacts *ps;
2048 int intrval;
2049 int ret = 0;
2050
2051 PROC_LOCK_ASSERT(p, MA_OWNED);
2052
2053 if (!_SIG_VALID(sig))
2054 #ifdef KSE
2055 panic("do_tdsignal(): invalid signal %d", sig);
2056 #else
2057 panic("tdsignal(): invalid signal %d", sig);
2058 #endif
2059
2060 #ifdef KSE
2061 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("do_tdsignal: ksi on queue"));
2062 #else
2063 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("tdsignal: ksi on queue"));
2064 #endif
2065
2066 /*
2067 * IEEE Std 1003.1-2001: return success when killing a zombie.
2068 */
2069 if (p->p_state == PRS_ZOMBIE) {
2070 if (ksi && (ksi->ksi_flags & KSI_INS))
2071 ksiginfo_tryfree(ksi);
2072 return (ret);
2073 }
2074
2075 ps = p->p_sigacts;
2076 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig);
2077 prop = sigprop(sig);
2078
2079 /*
2080 * If the signal is blocked and not destined for this thread, then
2081 * assign it to the process so that we can find it later in the first
2082 * thread that unblocks it. Otherwise, assign it to this thread now.
2083 */
2084 if (td == NULL) {
2085 td = sigtd(p, sig, prop);
2086 if (SIGISMEMBER(td->td_sigmask, sig))
2087 sigqueue = &p->p_sigqueue;
2088 else
2089 sigqueue = &td->td_sigqueue;
2090 } else {
2091 KASSERT(td->td_proc == p, ("invalid thread"));
2092 sigqueue = &td->td_sigqueue;
2093 }
2094
2095 /*
2096 * If the signal is being ignored,
2097 * then we forget about it immediately.
2098 * (Note: we don't set SIGCONT in ps_sigignore,
2099 * and if it is set to SIG_IGN,
2100 * action will be SIG_DFL here.)
2101 */
2102 mtx_lock(&ps->ps_mtx);
2103 if (SIGISMEMBER(ps->ps_sigignore, sig)) {
2104 mtx_unlock(&ps->ps_mtx);
2105 if (ksi && (ksi->ksi_flags & KSI_INS))
2106 ksiginfo_tryfree(ksi);
2107 return (ret);
2108 }
2109 if (SIGISMEMBER(td->td_sigmask, sig))
2110 action = SIG_HOLD;
2111 else if (SIGISMEMBER(ps->ps_sigcatch, sig))
2112 action = SIG_CATCH;
2113 else
2114 action = SIG_DFL;
2115 if (SIGISMEMBER(ps->ps_sigintr, sig))
2116 intrval = EINTR;
2117 else
2118 intrval = ERESTART;
2119 mtx_unlock(&ps->ps_mtx);
2120
2121 if (prop & SA_CONT)
2122 sigqueue_delete_stopmask_proc(p);
2123 else if (prop & SA_STOP) {
2124 /*
2125 * If sending a tty stop signal to a member of an orphaned
2126 * process group, discard the signal here if the action
2127 * is default; don't stop the process below if sleeping,
2128 * and don't clear any pending SIGCONT.
2129 */
2130 if ((prop & SA_TTYSTOP) &&
2131 (p->p_pgrp->pg_jobc == 0) &&
2132 (action == SIG_DFL)) {
2133 if (ksi && (ksi->ksi_flags & KSI_INS))
2134 ksiginfo_tryfree(ksi);
2135 return (ret);
2136 }
2137 PROC_SLOCK(p);
2138 sigqueue_delete_proc(p, SIGCONT);
2139 PROC_SUNLOCK(p);
2140 if (p->p_flag & P_CONTINUED) {
2141 p->p_flag &= ~P_CONTINUED;
2142 PROC_LOCK(p->p_pptr);
2143 sigqueue_take(p->p_ksi);
2144 PROC_UNLOCK(p->p_pptr);
2145 }
2146 }
2147
2148 ret = sigqueue_add(sigqueue, sig, ksi);
2149 if (ret != 0)
2150 return (ret);
2151 signotify(td);
2152 /*
2153 * Defer further processing for signals which are held,
2154 * except that stopped processes must be continued by SIGCONT.
2155 */
2156 if (action == SIG_HOLD &&
2157 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG)))
2158 return (ret);
2159 /*
2160 * SIGKILL: Remove procfs STOPEVENTs.
2161 */
2162 if (sig == SIGKILL) {
2163 /* from procfs_ioctl.c: PIOCBIC */
2164 p->p_stops = 0;
2165 /* from procfs_ioctl.c: PIOCCONT */
2166 p->p_step = 0;
2167 wakeup(&p->p_step);
2168 }
2169 /*
2170 * Some signals have a process-wide effect and a per-thread
2171 * component. Most processing occurs when the process next
2172 * tries to cross the user boundary, however there are some
2173 * times when processing needs to be done immediatly, such as
2174 * waking up threads so that they can cross the user boundary.
2175 * We try do the per-process part here.
2176 */
2177 PROC_SLOCK(p);
2178 if (P_SHOULDSTOP(p)) {
2179 /*
2180 * The process is in stopped mode. All the threads should be
2181 * either winding down or already on the suspended queue.
2182 */
2183 if (p->p_flag & P_TRACED) {
2184 /*
2185 * The traced process is already stopped,
2186 * so no further action is necessary.
2187 * No signal can restart us.
2188 */
2189 PROC_SUNLOCK(p);
2190 goto out;
2191 }
2192
2193 if (sig == SIGKILL) {
2194 /*
2195 * SIGKILL sets process running.
2196 * It will die elsewhere.
2197 * All threads must be restarted.
2198 */
2199 p->p_flag &= ~P_STOPPED_SIG;
2200 goto runfast;
2201 }
2202
2203 if (prop & SA_CONT) {
2204 /*
2205 * If SIGCONT is default (or ignored), we continue the
2206 * process but don't leave the signal in sigqueue as
2207 * it has no further action. If SIGCONT is held, we
2208 * continue the process and leave the signal in
2209 * sigqueue. If the process catches SIGCONT, let it
2210 * handle the signal itself. If it isn't waiting on
2211 * an event, it goes back to run state.
2212 * Otherwise, process goes back to sleep state.
2213 */
2214 p->p_flag &= ~P_STOPPED_SIG;
2215 if (p->p_numthreads == p->p_suspcount) {
2216 PROC_SUNLOCK(p);
2217 p->p_flag |= P_CONTINUED;
2218 p->p_xstat = SIGCONT;
2219 PROC_LOCK(p->p_pptr);
2220 childproc_continued(p);
2221 PROC_UNLOCK(p->p_pptr);
2222 PROC_SLOCK(p);
2223 }
2224 if (action == SIG_DFL) {
2225 thread_unsuspend(p);
2226 PROC_SUNLOCK(p);
2227 sigqueue_delete(sigqueue, sig);
2228 goto out;
2229 }
2230 if (action == SIG_CATCH) {
2231 #ifdef KSE
2232 /*
2233 * The process wants to catch it so it needs
2234 * to run at least one thread, but which one?
2235 * It would seem that the answer would be to
2236 * run an upcall in the next KSE to run, and
2237 * deliver the signal that way. In a NON KSE
2238 * process, we need to make sure that the
2239 * single thread is runnable asap.
2240 * XXXKSE for now however, make them all run.
2241 */
2242 #endif
2243 /*
2244 * The process wants to catch it so it needs
2245 * to run at least one thread, but which one?
2246 */
2247 goto runfast;
2248 }
2249 /*
2250 * The signal is not ignored or caught.
2251 */
2252 thread_unsuspend(p);
2253 PROC_SUNLOCK(p);
2254 goto out;
2255 }
2256
2257 if (prop & SA_STOP) {
2258 /*
2259 * Already stopped, don't need to stop again
2260 * (If we did the shell could get confused).
2261 * Just make sure the signal STOP bit set.
2262 */
2263 PROC_SUNLOCK(p);
2264 p->p_flag |= P_STOPPED_SIG;
2265 sigqueue_delete(sigqueue, sig);
2266 goto out;
2267 }
2268
2269 /*
2270 * All other kinds of signals:
2271 * If a thread is sleeping interruptibly, simulate a
2272 * wakeup so that when it is continued it will be made
2273 * runnable and can look at the signal. However, don't make
2274 * the PROCESS runnable, leave it stopped.
2275 * It may run a bit until it hits a thread_suspend_check().
2276 */
2277 thread_lock(td);
2278 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR))
2279 sleepq_abort(td, intrval);
2280 thread_unlock(td);
2281 PROC_SUNLOCK(p);
2282 goto out;
2283 /*
2284 * Mutexes are short lived. Threads waiting on them will
2285 * hit thread_suspend_check() soon.
2286 */
2287 } else if (p->p_state == PRS_NORMAL) {
2288 if (p->p_flag & P_TRACED || action == SIG_CATCH) {
2289 thread_lock(td);
2290 tdsigwakeup(td, sig, action, intrval);
2291 thread_unlock(td);
2292 PROC_SUNLOCK(p);
2293 goto out;
2294 }
2295
2296 MPASS(action == SIG_DFL);
2297
2298 if (prop & SA_STOP) {
2299 if (p->p_flag & P_PPWAIT) {
2300 PROC_SUNLOCK(p);
2301 goto out;
2302 }
2303 p->p_flag |= P_STOPPED_SIG;
2304 p->p_xstat = sig;
2305 sig_suspend_threads(td, p, 1);
2306 if (p->p_numthreads == p->p_suspcount) {
2307 /*
2308 * only thread sending signal to another
2309 * process can reach here, if thread is sending
2310 * signal to its process, because thread does
2311 * not suspend itself here, p_numthreads
2312 * should never be equal to p_suspcount.
2313 */
2314 thread_stopped(p);
2315 PROC_SUNLOCK(p);
2316 sigqueue_delete_proc(p, p->p_xstat);
2317 } else
2318 PROC_SUNLOCK(p);
2319 goto out;
2320 }
2321 else
2322 goto runfast;
2323 /* NOTREACHED */
2324 } else {
2325 /* Not in "NORMAL" state. discard the signal. */
2326 PROC_SUNLOCK(p);
2327 sigqueue_delete(sigqueue, sig);
2328 goto out;
2329 }
2330
2331 /*
2332 * The process is not stopped so we need to apply the signal to all the
2333 * running threads.
2334 */
2335
2336 runfast:
2337 thread_lock(td);
2338 tdsigwakeup(td, sig, action, intrval);
2339 thread_unlock(td);
2340 thread_unsuspend(p);
2341 PROC_SUNLOCK(p);
2342 out:
2343 /* If we jump here, proc slock should not be owned. */
2344 PROC_SLOCK_ASSERT(p, MA_NOTOWNED);
2345 return (ret);
2346 }
2347
2348 /*
2349 * The force of a signal has been directed against a single
2350 * thread. We need to see what we can do about knocking it
2351 * out of any sleep it may be in etc.
2352 */
2353 static void
2354 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval)
2355 {
2356 struct proc *p = td->td_proc;
2357 register int prop;
2358
2359 PROC_LOCK_ASSERT(p, MA_OWNED);
2360 PROC_SLOCK_ASSERT(p, MA_OWNED);
2361 THREAD_LOCK_ASSERT(td, MA_OWNED);
2362 prop = sigprop(sig);
2363
2364 /*
2365 * Bring the priority of a thread up if we want it to get
2366 * killed in this lifetime.
2367 */
2368 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER)
2369 sched_prio(td, PUSER);
2370
2371 if (TD_ON_SLEEPQ(td)) {
2372 /*
2373 * If thread is sleeping uninterruptibly
2374 * we can't interrupt the sleep... the signal will
2375 * be noticed when the process returns through
2376 * trap() or syscall().
2377 */
2378 if ((td->td_flags & TDF_SINTR) == 0)
2379 return;
2380 /*
2381 * If SIGCONT is default (or ignored) and process is
2382 * asleep, we are finished; the process should not
2383 * be awakened.
2384 */
2385 if ((prop & SA_CONT) && action == SIG_DFL) {
2386 thread_unlock(td);
2387 PROC_SUNLOCK(p);
2388 sigqueue_delete(&p->p_sigqueue, sig);
2389 /*
2390 * It may be on either list in this state.
2391 * Remove from both for now.
2392 */
2393 sigqueue_delete(&td->td_sigqueue, sig);
2394 PROC_SLOCK(p);
2395 thread_lock(td);
2396 return;
2397 }
2398
2399 /*
2400 * Give low priority threads a better chance to run.
2401 */
2402 if (td->td_priority > PUSER)
2403 sched_prio(td, PUSER);
2404
2405 sleepq_abort(td, intrval);
2406 } else {
2407 /*
2408 * Other states do nothing with the signal immediately,
2409 * other than kicking ourselves if we are running.
2410 * It will either never be noticed, or noticed very soon.
2411 */
2412 #ifdef SMP
2413 if (TD_IS_RUNNING(td) && td != curthread)
2414 forward_signal(td);
2415 #endif
2416 }
2417 }
2418
2419 static void
2420 sig_suspend_threads(struct thread *td, struct proc *p, int sending)
2421 {
2422 struct thread *td2;
2423
2424 PROC_LOCK_ASSERT(p, MA_OWNED);
2425 PROC_SLOCK_ASSERT(p, MA_OWNED);
2426
2427 FOREACH_THREAD_IN_PROC(p, td2) {
2428 thread_lock(td2);
2429 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) &&
2430 (td2->td_flags & TDF_SINTR) &&
2431 !TD_IS_SUSPENDED(td2)) {
2432 thread_suspend_one(td2);
2433 } else {
2434 if (sending || td != td2)
2435 td2->td_flags |= TDF_ASTPENDING;
2436 #ifdef SMP
2437 if (TD_IS_RUNNING(td2) && td2 != td)
2438 forward_signal(td2);
2439 #endif
2440 }
2441 thread_unlock(td2);
2442 }
2443 }
2444
2445 int
2446 ptracestop(struct thread *td, int sig)
2447 {
2448 struct proc *p = td->td_proc;
2449
2450 PROC_LOCK_ASSERT(p, MA_OWNED);
2451 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
2452 &p->p_mtx.lock_object, "Stopping for traced signal");
2453
2454 thread_lock(td);
2455 td->td_flags |= TDF_XSIG;
2456 thread_unlock(td);
2457 td->td_xsig = sig;
2458 PROC_SLOCK(p);
2459 while ((p->p_flag & P_TRACED) && (td->td_flags & TDF_XSIG)) {
2460 if (p->p_flag & P_SINGLE_EXIT) {
2461 thread_lock(td);
2462 td->td_flags &= ~TDF_XSIG;
2463 thread_unlock(td);
2464 PROC_SUNLOCK(p);
2465 return (sig);
2466 }
2467 /*
2468 * Just make wait() to work, the last stopped thread
2469 * will win.
2470 */
2471 p->p_xstat = sig;
2472 p->p_xthread = td;
2473 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE);
2474 sig_suspend_threads(td, p, 0);
2475 stopme:
2476 thread_suspend_switch(td);
2477 if (!(p->p_flag & P_TRACED)) {
2478 break;
2479 }
2480 if (td->td_flags & TDF_DBSUSPEND) {
2481 if (p->p_flag & P_SINGLE_EXIT)
2482 break;
2483 goto stopme;
2484 }
2485 }
2486 PROC_SUNLOCK(p);
2487 return (td->td_xsig);
2488 }
2489
2490 /*
2491 * If the current process has received a signal (should be caught or cause
2492 * termination, should interrupt current syscall), return the signal number.
2493 * Stop signals with default action are processed immediately, then cleared;
2494 * they aren't returned. This is checked after each entry to the system for
2495 * a syscall or trap (though this can usually be done without calling issignal
2496 * by checking the pending signal masks in cursig.) The normal call
2497 * sequence is
2498 *
2499 * while (sig = cursig(curthread))
2500 * postsig(sig);
2501 */
2502 static int
2503 issignal(td)
2504 struct thread *td;
2505 {
2506 struct proc *p;
2507 struct sigacts *ps;
2508 sigset_t sigpending;
2509 int sig, prop, newsig;
2510
2511 p = td->td_proc;
2512 ps = p->p_sigacts;
2513 mtx_assert(&ps->ps_mtx, MA_OWNED);
2514 PROC_LOCK_ASSERT(p, MA_OWNED);
2515 for (;;) {
2516 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
2517
2518 sigpending = td->td_sigqueue.sq_signals;
2519 SIGSETNAND(sigpending, td->td_sigmask);
2520
2521 if (p->p_flag & P_PPWAIT)
2522 SIG_STOPSIGMASK(sigpending);
2523 if (SIGISEMPTY(sigpending)) /* no signal to send */
2524 return (0);
2525 sig = sig_ffs(&sigpending);
2526
2527 if (p->p_stops & S_SIG) {
2528 mtx_unlock(&ps->ps_mtx);
2529 stopevent(p, S_SIG, sig);
2530 mtx_lock(&ps->ps_mtx);
2531 }
2532
2533 /*
2534 * We should see pending but ignored signals
2535 * only if P_TRACED was on when they were posted.
2536 */
2537 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) {
2538 sigqueue_delete(&td->td_sigqueue, sig);
2539 #ifdef KSE
2540 if (td->td_pflags & TDP_SA)
2541 SIGADDSET(td->td_sigmask, sig);
2542 #endif
2543 continue;
2544 }
2545 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) {
2546 /*
2547 * If traced, always stop.
2548 */
2549 mtx_unlock(&ps->ps_mtx);
2550 newsig = ptracestop(td, sig);
2551 mtx_lock(&ps->ps_mtx);
2552
2553 #ifdef KSE
2554 if (td->td_pflags & TDP_SA)
2555 SIGADDSET(td->td_sigmask, sig);
2556
2557 #endif
2558 if (sig != newsig) {
2559 ksiginfo_t ksi;
2560 /*
2561 * clear old signal.
2562 * XXX shrug off debugger, it causes siginfo to
2563 * be thrown away.
2564 */
2565 sigqueue_get(&td->td_sigqueue, sig, &ksi);
2566
2567 /*
2568 * If parent wants us to take the signal,
2569 * then it will leave it in p->p_xstat;
2570 * otherwise we just look for signals again.
2571 */
2572 if (newsig == 0)
2573 continue;
2574 sig = newsig;
2575
2576 /*
2577 * Put the new signal into td_sigqueue. If the
2578 * signal is being masked, look for other signals.
2579 */
2580 SIGADDSET(td->td_sigqueue.sq_signals, sig);
2581 #ifdef KSE
2582 if (td->td_pflags & TDP_SA)
2583 SIGDELSET(td->td_sigmask, sig);
2584 #endif
2585 if (SIGISMEMBER(td->td_sigmask, sig))
2586 continue;
2587 signotify(td);
2588 }
2589
2590 /*
2591 * If the traced bit got turned off, go back up
2592 * to the top to rescan signals. This ensures
2593 * that p_sig* and p_sigact are consistent.
2594 */
2595 if ((p->p_flag & P_TRACED) == 0)
2596 continue;
2597 }
2598
2599 prop = sigprop(sig);
2600
2601 /*
2602 * Decide whether the signal should be returned.
2603 * Return the signal's number, or fall through
2604 * to clear it from the pending mask.
2605 */
2606 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
2607
2608 case (intptr_t)SIG_DFL:
2609 /*
2610 * Don't take default actions on system processes.
2611 */
2612 if (p->p_pid <= 1) {
2613 #ifdef DIAGNOSTIC
2614 /*
2615 * Are you sure you want to ignore SIGSEGV
2616 * in init? XXX
2617 */
2618 printf("Process (pid %lu) got signal %d\n",
2619 (u_long)p->p_pid, sig);
2620 #endif
2621 break; /* == ignore */
2622 }
2623 /*
2624 * If there is a pending stop signal to process
2625 * with default action, stop here,
2626 * then clear the signal. However,
2627 * if process is member of an orphaned
2628 * process group, ignore tty stop signals.
2629 */
2630 if (prop & SA_STOP) {
2631 if (p->p_flag & P_TRACED ||
2632 (p->p_pgrp->pg_jobc == 0 &&
2633 prop & SA_TTYSTOP))
2634 break; /* == ignore */
2635 mtx_unlock(&ps->ps_mtx);
2636 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
2637 &p->p_mtx.lock_object, "Catching SIGSTOP");
2638 p->p_flag |= P_STOPPED_SIG;
2639 p->p_xstat = sig;
2640 PROC_SLOCK(p);
2641 sig_suspend_threads(td, p, 0);
2642 thread_suspend_switch(td);
2643 PROC_SUNLOCK(p);
2644 mtx_lock(&ps->ps_mtx);
2645 break;
2646 } else if (prop & SA_IGNORE) {
2647 /*
2648 * Except for SIGCONT, shouldn't get here.
2649 * Default action is to ignore; drop it.
2650 */
2651 break; /* == ignore */
2652 } else
2653 return (sig);
2654 /*NOTREACHED*/
2655
2656 case (intptr_t)SIG_IGN:
2657 /*
2658 * Masking above should prevent us ever trying
2659 * to take action on an ignored signal other
2660 * than SIGCONT, unless process is traced.
2661 */
2662 if ((prop & SA_CONT) == 0 &&
2663 (p->p_flag & P_TRACED) == 0)
2664 printf("issignal\n");
2665 break; /* == ignore */
2666
2667 default:
2668 /*
2669 * This signal has an action, let
2670 * postsig() process it.
2671 */
2672 return (sig);
2673 }
2674 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */
2675 }
2676 /* NOTREACHED */
2677 }
2678
2679 void
2680 thread_stopped(struct proc *p)
2681 {
2682 int n;
2683
2684 PROC_LOCK_ASSERT(p, MA_OWNED);
2685 PROC_SLOCK_ASSERT(p, MA_OWNED);
2686 n = p->p_suspcount;
2687 if (p == curproc)
2688 n++;
2689 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) {
2690 PROC_SUNLOCK(p);
2691 p->p_flag &= ~P_WAITED;
2692 PROC_LOCK(p->p_pptr);
2693 childproc_stopped(p, (p->p_flag & P_TRACED) ?
2694 CLD_TRAPPED : CLD_STOPPED);
2695 PROC_UNLOCK(p->p_pptr);
2696 PROC_SLOCK(p);
2697 }
2698 }
2699
2700 /*
2701 * Take the action for the specified signal
2702 * from the current set of pending signals.
2703 */
2704 void
2705 postsig(sig)
2706 register int sig;
2707 {
2708 struct thread *td = curthread;
2709 register struct proc *p = td->td_proc;
2710 struct sigacts *ps;
2711 sig_t action;
2712 ksiginfo_t ksi;
2713 sigset_t returnmask;
2714 int code;
2715
2716 KASSERT(sig != 0, ("postsig"));
2717
2718 PROC_LOCK_ASSERT(p, MA_OWNED);
2719 ps = p->p_sigacts;
2720 mtx_assert(&ps->ps_mtx, MA_OWNED);
2721 ksiginfo_init(&ksi);
2722 sigqueue_get(&td->td_sigqueue, sig, &ksi);
2723 ksi.ksi_signo = sig;
2724 if (ksi.ksi_code == SI_TIMER)
2725 itimer_accept(p, ksi.ksi_timerid, &ksi);
2726 action = ps->ps_sigact[_SIG_IDX(sig)];
2727 #ifdef KTRACE
2728 if (KTRPOINT(td, KTR_PSIG))
2729 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ?
2730 &td->td_oldsigmask : &td->td_sigmask, 0);
2731 #endif
2732 if (p->p_stops & S_SIG) {
2733 mtx_unlock(&ps->ps_mtx);
2734 stopevent(p, S_SIG, sig);
2735 mtx_lock(&ps->ps_mtx);
2736 }
2737
2738 #ifdef KSE
2739 if (!(td->td_pflags & TDP_SA) && action == SIG_DFL) {
2740 #else
2741 if (action == SIG_DFL) {
2742 #endif
2743 /*
2744 * Default action, where the default is to kill
2745 * the process. (Other cases were ignored above.)
2746 */
2747 mtx_unlock(&ps->ps_mtx);
2748 sigexit(td, sig);
2749 /* NOTREACHED */
2750 } else {
2751 #ifdef KSE
2752 if (td->td_pflags & TDP_SA) {
2753 if (sig == SIGKILL) {
2754 mtx_unlock(&ps->ps_mtx);
2755 sigexit(td, sig);
2756 }
2757 }
2758
2759 #endif
2760 /*
2761 * If we get here, the signal must be caught.
2762 */
2763 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig),
2764 ("postsig action"));
2765 /*
2766 * Set the new mask value and also defer further
2767 * occurrences of this signal.
2768 *
2769 * Special case: user has done a sigsuspend. Here the
2770 * current mask is not of interest, but rather the
2771 * mask from before the sigsuspend is what we want
2772 * restored after the signal processing is completed.
2773 */
2774 if (td->td_pflags & TDP_OLDMASK) {
2775 returnmask = td->td_oldsigmask;
2776 td->td_pflags &= ~TDP_OLDMASK;
2777 } else
2778 returnmask = td->td_sigmask;
2779
2780 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
2781 if (!SIGISMEMBER(ps->ps_signodefer, sig))
2782 SIGADDSET(td->td_sigmask, sig);
2783
2784 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
2785 /*
2786 * See kern_sigaction() for origin of this code.
2787 */
2788 SIGDELSET(ps->ps_sigcatch, sig);
2789 if (sig != SIGCONT &&
2790 sigprop(sig) & SA_IGNORE)
2791 SIGADDSET(ps->ps_sigignore, sig);
2792 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
2793 }
2794 td->td_ru.ru_nsignals++;
2795 if (p->p_sig != sig) {
2796 code = 0;
2797 } else {
2798 code = p->p_code;
2799 p->p_code = 0;
2800 p->p_sig = 0;
2801 }
2802 #ifdef KSE
2803 if (td->td_pflags & TDP_SA)
2804 thread_signal_add(curthread, &ksi);
2805 else
2806 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask);
2807 #else
2808 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask);
2809 #endif
2810 }
2811 }
2812
2813 /*
2814 * Kill the current process for stated reason.
2815 */
2816 void
2817 killproc(p, why)
2818 struct proc *p;
2819 char *why;
2820 {
2821
2822 PROC_LOCK_ASSERT(p, MA_OWNED);
2823 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)",
2824 p, p->p_pid, p->p_comm);
2825 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm,
2826 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
2827 psignal(p, SIGKILL);
2828 }
2829
2830 /*
2831 * Force the current process to exit with the specified signal, dumping core
2832 * if appropriate. We bypass the normal tests for masked and caught signals,
2833 * allowing unrecoverable failures to terminate the process without changing
2834 * signal state. Mark the accounting record with the signal termination.
2835 * If dumping core, save the signal number for the debugger. Calls exit and
2836 * does not return.
2837 */
2838 void
2839 sigexit(td, sig)
2840 struct thread *td;
2841 int sig;
2842 {
2843 struct proc *p = td->td_proc;
2844
2845 PROC_LOCK_ASSERT(p, MA_OWNED);
2846 p->p_acflag |= AXSIG;
2847 /*
2848 * We must be single-threading to generate a core dump. This
2849 * ensures that the registers in the core file are up-to-date.
2850 * Also, the ELF dump handler assumes that the thread list doesn't
2851 * change out from under it.
2852 *
2853 * XXX If another thread attempts to single-thread before us
2854 * (e.g. via fork()), we won't get a dump at all.
2855 */
2856 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) {
2857 p->p_sig = sig;
2858 /*
2859 * Log signals which would cause core dumps
2860 * (Log as LOG_INFO to appease those who don't want
2861 * these messages.)
2862 * XXX : Todo, as well as euid, write out ruid too
2863 * Note that coredump() drops proc lock.
2864 */
2865 if (coredump(td) == 0)
2866 sig |= WCOREFLAG;
2867 if (kern_logsigexit)
2868 log(LOG_INFO,
2869 "pid %d (%s), uid %d: exited on signal %d%s\n",
2870 p->p_pid, p->p_comm,
2871 td->td_ucred ? td->td_ucred->cr_uid : -1,
2872 sig &~ WCOREFLAG,
2873 sig & WCOREFLAG ? " (core dumped)" : "");
2874 } else
2875 PROC_UNLOCK(p);
2876 exit1(td, W_EXITCODE(0, sig));
2877 /* NOTREACHED */
2878 }
2879
2880 /*
2881 * Send queued SIGCHLD to parent when child process's state
2882 * is changed.
2883 */
2884 static void
2885 sigparent(struct proc *p, int reason, int status)
2886 {
2887 PROC_LOCK_ASSERT(p, MA_OWNED);
2888 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
2889
2890 if (p->p_ksi != NULL) {
2891 p->p_ksi->ksi_signo = SIGCHLD;
2892 p->p_ksi->ksi_code = reason;
2893 p->p_ksi->ksi_status = status;
2894 p->p_ksi->ksi_pid = p->p_pid;
2895 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid;
2896 if (KSI_ONQ(p->p_ksi))
2897 return;
2898 }
2899 tdsignal(p->p_pptr, NULL, SIGCHLD, p->p_ksi);
2900 }
2901
2902 static void
2903 childproc_jobstate(struct proc *p, int reason, int status)
2904 {
2905 struct sigacts *ps;
2906
2907 PROC_LOCK_ASSERT(p, MA_OWNED);
2908 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
2909
2910 /*
2911 * Wake up parent sleeping in kern_wait(), also send
2912 * SIGCHLD to parent, but SIGCHLD does not guarantee
2913 * that parent will awake, because parent may masked
2914 * the signal.
2915 */
2916 p->p_pptr->p_flag |= P_STATCHILD;
2917 wakeup(p->p_pptr);
2918
2919 ps = p->p_pptr->p_sigacts;
2920 mtx_lock(&ps->ps_mtx);
2921 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) {
2922 mtx_unlock(&ps->ps_mtx);
2923 sigparent(p, reason, status);
2924 } else
2925 mtx_unlock(&ps->ps_mtx);
2926 }
2927
2928 void
2929 childproc_stopped(struct proc *p, int reason)
2930 {
2931 childproc_jobstate(p, reason, p->p_xstat);
2932 }
2933
2934 void
2935 childproc_continued(struct proc *p)
2936 {
2937 childproc_jobstate(p, CLD_CONTINUED, SIGCONT);
2938 }
2939
2940 void
2941 childproc_exited(struct proc *p)
2942 {
2943 int reason;
2944 int status = p->p_xstat; /* convert to int */
2945
2946 reason = CLD_EXITED;
2947 if (WCOREDUMP(status))
2948 reason = CLD_DUMPED;
2949 else if (WIFSIGNALED(status))
2950 reason = CLD_KILLED;
2951 /*
2952 * XXX avoid calling wakeup(p->p_pptr), the work is
2953 * done in exit1().
2954 */
2955 sigparent(p, reason, status);
2956 }
2957
2958 static char corefilename[MAXPATHLEN] = {"%N.core"};
2959 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
2960 sizeof(corefilename), "process corefile name format string");
2961
2962 /*
2963 * expand_name(name, uid, pid)
2964 * Expand the name described in corefilename, using name, uid, and pid.
2965 * corefilename is a printf-like string, with three format specifiers:
2966 * %N name of process ("name")
2967 * %P process id (pid)
2968 * %U user id (uid)
2969 * For example, "%N.core" is the default; they can be disabled completely
2970 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
2971 * This is controlled by the sysctl variable kern.corefile (see above).
2972 */
2973
2974 static char *
2975 expand_name(name, uid, pid)
2976 const char *name;
2977 uid_t uid;
2978 pid_t pid;
2979 {
2980 const char *format, *appendstr;
2981 char *temp;
2982 char buf[11]; /* Buffer for pid/uid -- max 4B */
2983 size_t i, l, n;
2984
2985 format = corefilename;
2986 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO);
2987 if (temp == NULL)
2988 return (NULL);
2989 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
2990 switch (format[i]) {
2991 case '%': /* Format character */
2992 i++;
2993 switch (format[i]) {
2994 case '%':
2995 appendstr = "%";
2996 break;
2997 case 'N': /* process name */
2998 appendstr = name;
2999 break;
3000 case 'P': /* process id */
3001 sprintf(buf, "%u", pid);
3002 appendstr = buf;
3003 break;
3004 case 'U': /* user id */
3005 sprintf(buf, "%u", uid);
3006 appendstr = buf;
3007 break;
3008 default:
3009 appendstr = "";
3010 log(LOG_ERR,
3011 "Unknown format character %c in `%s'\n",
3012 format[i], format);
3013 }
3014 l = strlen(appendstr);
3015 if ((n + l) >= MAXPATHLEN)
3016 goto toolong;
3017 memcpy(temp + n, appendstr, l);
3018 n += l;
3019 break;
3020 default:
3021 temp[n++] = format[i];
3022 }
3023 }
3024 if (format[i] != '\0')
3025 goto toolong;
3026 return (temp);
3027 toolong:
3028 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too long\n",
3029 (long)pid, name, (u_long)uid);
3030 free(temp, M_TEMP);
3031 return (NULL);
3032 }
3033
3034 /*
3035 * Dump a process' core. The main routine does some
3036 * policy checking, and creates the name of the coredump;
3037 * then it passes on a vnode and a size limit to the process-specific
3038 * coredump routine if there is one; if there _is not_ one, it returns
3039 * ENOSYS; otherwise it returns the error from the process-specific routine.
3040 */
3041
3042 static int
3043 coredump(struct thread *td)
3044 {
3045 struct proc *p = td->td_proc;
3046 register struct vnode *vp;
3047 register struct ucred *cred = td->td_ucred;
3048 struct flock lf;
3049 struct nameidata nd;
3050 struct vattr vattr;
3051 int error, error1, flags, locked;
3052 struct mount *mp;
3053 char *name; /* name of corefile */
3054 off_t limit;
3055 int vfslocked;
3056
3057 PROC_LOCK_ASSERT(p, MA_OWNED);
3058 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td);
3059 _STOPEVENT(p, S_CORE, 0);
3060
3061 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) {
3062 PROC_UNLOCK(p);
3063 return (EFAULT);
3064 }
3065
3066 /*
3067 * Note that the bulk of limit checking is done after
3068 * the corefile is created. The exception is if the limit
3069 * for corefiles is 0, in which case we don't bother
3070 * creating the corefile at all. This layout means that
3071 * a corefile is truncated instead of not being created,
3072 * if it is larger than the limit.
3073 */
3074 limit = (off_t)lim_cur(p, RLIMIT_CORE);
3075 PROC_UNLOCK(p);
3076 if (limit == 0)
3077 return (EFBIG);
3078
3079 restart:
3080 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid);
3081 if (name == NULL)
3082 return (EINVAL);
3083 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, name, td);
3084 flags = O_CREAT | FWRITE | O_NOFOLLOW;
3085 error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR, NULL);
3086 free(name, M_TEMP);
3087 if (error)
3088 return (error);
3089 vfslocked = NDHASGIANT(&nd);
3090 NDFREE(&nd, NDF_ONLY_PNBUF);
3091 vp = nd.ni_vp;
3092
3093 /* Don't dump to non-regular files or files with links. */
3094 if (vp->v_type != VREG ||
3095 VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) {
3096 VOP_UNLOCK(vp, 0, td);
3097 error = EFAULT;
3098 goto close;
3099 }
3100
3101 VOP_UNLOCK(vp, 0, td);
3102 lf.l_whence = SEEK_SET;
3103 lf.l_start = 0;
3104 lf.l_len = 0;
3105 lf.l_type = F_WRLCK;
3106 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0);
3107
3108 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
3109 lf.l_type = F_UNLCK;
3110 if (locked)
3111 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
3112 if ((error = vn_close(vp, FWRITE, cred, td)) != 0)
3113 goto out;
3114 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
3115 goto out;
3116 VFS_UNLOCK_GIANT(vfslocked);
3117 goto restart;
3118 }
3119
3120 VATTR_NULL(&vattr);
3121 vattr.va_size = 0;
3122 if (set_core_nodump_flag)
3123 vattr.va_flags = UF_NODUMP;
3124 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
3125 VOP_LEASE(vp, td, cred, LEASE_WRITE);
3126 VOP_SETATTR(vp, &vattr, cred, td);
3127 VOP_UNLOCK(vp, 0, td);
3128 vn_finished_write(mp);
3129 PROC_LOCK(p);
3130 p->p_acflag |= ACORE;
3131 PROC_UNLOCK(p);
3132
3133 error = p->p_sysent->sv_coredump ?
3134 p->p_sysent->sv_coredump(td, vp, limit) :
3135 ENOSYS;
3136
3137 if (locked) {
3138 lf.l_type = F_UNLCK;
3139 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
3140 }
3141 close:
3142 error1 = vn_close(vp, FWRITE, cred, td);
3143 if (error == 0)
3144 error = error1;
3145 out:
3146 VFS_UNLOCK_GIANT(vfslocked);
3147 return (error);
3148 }
3149
3150 /*
3151 * Nonexistent system call-- signal process (may want to handle it). Flag
3152 * error in case process won't see signal immediately (blocked or ignored).
3153 */
3154 #ifndef _SYS_SYSPROTO_H_
3155 struct nosys_args {
3156 int dummy;
3157 };
3158 #endif
3159 /* ARGSUSED */
3160 int
3161 nosys(td, args)
3162 struct thread *td;
3163 struct nosys_args *args;
3164 {
3165 struct proc *p = td->td_proc;
3166
3167 PROC_LOCK(p);
3168 psignal(p, SIGSYS);
3169 PROC_UNLOCK(p);
3170 return (ENOSYS);
3171 }
3172
3173 /*
3174 * Send a SIGIO or SIGURG signal to a process or process group using stored
3175 * credentials rather than those of the current process.
3176 */
3177 void
3178 pgsigio(sigiop, sig, checkctty)
3179 struct sigio **sigiop;
3180 int sig, checkctty;
3181 {
3182 struct sigio *sigio;
3183
3184 SIGIO_LOCK();
3185 sigio = *sigiop;
3186 if (sigio == NULL) {
3187 SIGIO_UNLOCK();
3188 return;
3189 }
3190 if (sigio->sio_pgid > 0) {
3191 PROC_LOCK(sigio->sio_proc);
3192 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred))
3193 psignal(sigio->sio_proc, sig);
3194 PROC_UNLOCK(sigio->sio_proc);
3195 } else if (sigio->sio_pgid < 0) {
3196 struct proc *p;
3197
3198 PGRP_LOCK(sigio->sio_pgrp);
3199 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
3200 PROC_LOCK(p);
3201 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) &&
3202 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
3203 psignal(p, sig);
3204 PROC_UNLOCK(p);
3205 }
3206 PGRP_UNLOCK(sigio->sio_pgrp);
3207 }
3208 SIGIO_UNLOCK();
3209 }
3210
3211 static int
3212 filt_sigattach(struct knote *kn)
3213 {
3214 struct proc *p = curproc;
3215
3216 kn->kn_ptr.p_proc = p;
3217 kn->kn_flags |= EV_CLEAR; /* automatically set */
3218
3219 knlist_add(&p->p_klist, kn, 0);
3220
3221 return (0);
3222 }
3223
3224 static void
3225 filt_sigdetach(struct knote *kn)
3226 {
3227 struct proc *p = kn->kn_ptr.p_proc;
3228
3229 knlist_remove(&p->p_klist, kn, 0);
3230 }
3231
3232 /*
3233 * signal knotes are shared with proc knotes, so we apply a mask to
3234 * the hint in order to differentiate them from process hints. This
3235 * could be avoided by using a signal-specific knote list, but probably
3236 * isn't worth the trouble.
3237 */
3238 static int
3239 filt_signal(struct knote *kn, long hint)
3240 {
3241
3242 if (hint & NOTE_SIGNAL) {
3243 hint &= ~NOTE_SIGNAL;
3244
3245 if (kn->kn_id == hint)
3246 kn->kn_data++;
3247 }
3248 return (kn->kn_data != 0);
3249 }
3250
3251 struct sigacts *
3252 sigacts_alloc(void)
3253 {
3254 struct sigacts *ps;
3255
3256 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO);
3257 ps->ps_refcnt = 1;
3258 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF);
3259 return (ps);
3260 }
3261
3262 void
3263 sigacts_free(struct sigacts *ps)
3264 {
3265
3266 mtx_lock(&ps->ps_mtx);
3267 ps->ps_refcnt--;
3268 if (ps->ps_refcnt == 0) {
3269 mtx_destroy(&ps->ps_mtx);
3270 free(ps, M_SUBPROC);
3271 } else
3272 mtx_unlock(&ps->ps_mtx);
3273 }
3274
3275 struct sigacts *
3276 sigacts_hold(struct sigacts *ps)
3277 {
3278 mtx_lock(&ps->ps_mtx);
3279 ps->ps_refcnt++;
3280 mtx_unlock(&ps->ps_mtx);
3281 return (ps);
3282 }
3283
3284 void
3285 sigacts_copy(struct sigacts *dest, struct sigacts *src)
3286 {
3287
3288 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest"));
3289 mtx_lock(&src->ps_mtx);
3290 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt));
3291 mtx_unlock(&src->ps_mtx);
3292 }
3293
3294 int
3295 sigacts_shared(struct sigacts *ps)
3296 {
3297 int shared;
3298
3299 mtx_lock(&ps->ps_mtx);
3300 shared = ps->ps_refcnt > 1;
3301 mtx_unlock(&ps->ps_mtx);
3302 return (shared);
3303 }
Cache object: 17612aa0c47235deaf02ce3c58e866a3
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