FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_sig.c
1 /*-
2 * Copyright (c) 1982, 1986, 1989, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94
35 */
36
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD: releng/7.3/sys/kern/kern_sig.c 197745 2009-10-04 13:00:27Z kib $");
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/sbuf.h>
64 #include <sys/sleepqueue.h>
65 #include <sys/smp.h>
66 #include <sys/stat.h>
67 #include <sys/sx.h>
68 #include <sys/syscallsubr.h>
69 #include <sys/sysctl.h>
70 #include <sys/sysent.h>
71 #include <sys/syslog.h>
72 #include <sys/sysproto.h>
73 #include <sys/timers.h>
74 #include <sys/unistd.h>
75 #include <sys/wait.h>
76 #include <vm/vm.h>
77 #include <vm/vm_extern.h>
78 #include <vm/uma.h>
79
80 #include <machine/cpu.h>
81
82 #include <security/audit/audit.h>
83
84 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */
85
86 static int coredump(struct thread *);
87 static char *expand_name(const char *, uid_t, pid_t);
88 static int killpg1(struct thread *td, int sig, int pgid, int all);
89 static int issignal(struct thread *p);
90 static int sigprop(int sig);
91 static int tdsigwakeup(struct thread *, int, sig_t, int);
92 static void sig_suspend_threads(struct thread *, struct proc *, int);
93 static int filt_sigattach(struct knote *kn);
94 static void filt_sigdetach(struct knote *kn);
95 static int filt_signal(struct knote *kn, long hint);
96 static struct thread *sigtd(struct proc *p, int sig, int prop);
97 #ifdef KSE
98 static int do_tdsignal(struct proc *, struct thread *, int, ksiginfo_t *);
99 #endif
100 static void sigqueue_start(void);
101
102 static uma_zone_t ksiginfo_zone = NULL;
103 struct filterops sig_filtops =
104 { 0, filt_sigattach, filt_sigdetach, filt_signal };
105
106 int kern_logsigexit = 1;
107 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
108 &kern_logsigexit, 0,
109 "Log processes quitting on abnormal signals to syslog(3)");
110
111 static int kern_forcesigexit = 1;
112 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW,
113 &kern_forcesigexit, 0, "Force trap signal to be handled");
114
115 SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, "POSIX real time signal");
116
117 static int max_pending_per_proc = 128;
118 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW,
119 &max_pending_per_proc, 0, "Max pending signals per proc");
120
121 static int preallocate_siginfo = 1024;
122 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo);
123 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD,
124 &preallocate_siginfo, 0, "Preallocated signal memory size");
125
126 static int signal_overflow = 0;
127 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD,
128 &signal_overflow, 0, "Number of signals overflew");
129
130 static int signal_alloc_fail = 0;
131 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD,
132 &signal_alloc_fail, 0, "signals failed to be allocated");
133
134 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL);
135
136 /*
137 * Policy -- Can ucred cr1 send SIGIO to process cr2?
138 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG
139 * in the right situations.
140 */
141 #define CANSIGIO(cr1, cr2) \
142 ((cr1)->cr_uid == 0 || \
143 (cr1)->cr_ruid == (cr2)->cr_ruid || \
144 (cr1)->cr_uid == (cr2)->cr_ruid || \
145 (cr1)->cr_ruid == (cr2)->cr_uid || \
146 (cr1)->cr_uid == (cr2)->cr_uid)
147
148 int sugid_coredump;
149 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
150 &sugid_coredump, 0, "Enable coredumping set user/group ID processes");
151
152 static int do_coredump = 1;
153 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
154 &do_coredump, 0, "Enable/Disable coredumps");
155
156 static int set_core_nodump_flag = 0;
157 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag,
158 0, "Enable setting the NODUMP flag on coredump files");
159
160 /*
161 * Signal properties and actions.
162 * The array below categorizes the signals and their default actions
163 * according to the following properties:
164 */
165 #define SA_KILL 0x01 /* terminates process by default */
166 #define SA_CORE 0x02 /* ditto and coredumps */
167 #define SA_STOP 0x04 /* suspend process */
168 #define SA_TTYSTOP 0x08 /* ditto, from tty */
169 #define SA_IGNORE 0x10 /* ignore by default */
170 #define SA_CONT 0x20 /* continue if suspended */
171 #define SA_CANTMASK 0x40 /* non-maskable, catchable */
172 #define SA_PROC 0x80 /* deliverable to any thread */
173
174 static int sigproptbl[NSIG] = {
175 SA_KILL|SA_PROC, /* SIGHUP */
176 SA_KILL|SA_PROC, /* SIGINT */
177 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */
178 SA_KILL|SA_CORE, /* SIGILL */
179 SA_KILL|SA_CORE, /* SIGTRAP */
180 SA_KILL|SA_CORE, /* SIGABRT */
181 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */
182 SA_KILL|SA_CORE, /* SIGFPE */
183 SA_KILL|SA_PROC, /* SIGKILL */
184 SA_KILL|SA_CORE, /* SIGBUS */
185 SA_KILL|SA_CORE, /* SIGSEGV */
186 SA_KILL|SA_CORE, /* SIGSYS */
187 SA_KILL|SA_PROC, /* SIGPIPE */
188 SA_KILL|SA_PROC, /* SIGALRM */
189 SA_KILL|SA_PROC, /* SIGTERM */
190 SA_IGNORE|SA_PROC, /* SIGURG */
191 SA_STOP|SA_PROC, /* SIGSTOP */
192 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */
193 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */
194 SA_IGNORE|SA_PROC, /* SIGCHLD */
195 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */
196 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */
197 SA_IGNORE|SA_PROC, /* SIGIO */
198 SA_KILL, /* SIGXCPU */
199 SA_KILL, /* SIGXFSZ */
200 SA_KILL|SA_PROC, /* SIGVTALRM */
201 SA_KILL|SA_PROC, /* SIGPROF */
202 SA_IGNORE|SA_PROC, /* SIGWINCH */
203 SA_IGNORE|SA_PROC, /* SIGINFO */
204 SA_KILL|SA_PROC, /* SIGUSR1 */
205 SA_KILL|SA_PROC, /* SIGUSR2 */
206 };
207
208 static void
209 sigqueue_start(void)
210 {
211 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t),
212 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
213 uma_prealloc(ksiginfo_zone, preallocate_siginfo);
214 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS);
215 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1);
216 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc);
217 }
218
219 ksiginfo_t *
220 ksiginfo_alloc(int wait)
221 {
222 int flags;
223
224 flags = M_ZERO;
225 if (! wait)
226 flags |= M_NOWAIT;
227 if (ksiginfo_zone != NULL)
228 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags));
229 return (NULL);
230 }
231
232 void
233 ksiginfo_free(ksiginfo_t *ksi)
234 {
235 uma_zfree(ksiginfo_zone, ksi);
236 }
237
238 static __inline int
239 ksiginfo_tryfree(ksiginfo_t *ksi)
240 {
241 if (!(ksi->ksi_flags & KSI_EXT)) {
242 uma_zfree(ksiginfo_zone, ksi);
243 return (1);
244 }
245 return (0);
246 }
247
248 void
249 sigqueue_init(sigqueue_t *list, struct proc *p)
250 {
251 SIGEMPTYSET(list->sq_signals);
252 SIGEMPTYSET(list->sq_kill);
253 TAILQ_INIT(&list->sq_list);
254 list->sq_proc = p;
255 list->sq_flags = SQ_INIT;
256 }
257
258 /*
259 * Get a signal's ksiginfo.
260 * Return:
261 * 0 - signal not found
262 * others - signal number
263 */
264 int
265 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si)
266 {
267 struct proc *p = sq->sq_proc;
268 struct ksiginfo *ksi, *next;
269 int count = 0;
270
271 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
272
273 if (!SIGISMEMBER(sq->sq_signals, signo))
274 return (0);
275
276 if (SIGISMEMBER(sq->sq_kill, signo)) {
277 count++;
278 SIGDELSET(sq->sq_kill, signo);
279 }
280
281 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
282 if (ksi->ksi_signo == signo) {
283 if (count == 0) {
284 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
285 ksi->ksi_sigq = NULL;
286 ksiginfo_copy(ksi, si);
287 if (ksiginfo_tryfree(ksi) && p != NULL)
288 p->p_pendingcnt--;
289 }
290 if (++count > 1)
291 break;
292 }
293 }
294
295 if (count <= 1)
296 SIGDELSET(sq->sq_signals, signo);
297 si->ksi_signo = signo;
298 return (signo);
299 }
300
301 void
302 sigqueue_take(ksiginfo_t *ksi)
303 {
304 struct ksiginfo *kp;
305 struct proc *p;
306 sigqueue_t *sq;
307
308 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL)
309 return;
310
311 p = sq->sq_proc;
312 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
313 ksi->ksi_sigq = NULL;
314 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL)
315 p->p_pendingcnt--;
316
317 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL;
318 kp = TAILQ_NEXT(kp, ksi_link)) {
319 if (kp->ksi_signo == ksi->ksi_signo)
320 break;
321 }
322 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo))
323 SIGDELSET(sq->sq_signals, ksi->ksi_signo);
324 }
325
326 int
327 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si)
328 {
329 struct proc *p = sq->sq_proc;
330 struct ksiginfo *ksi;
331 int ret = 0;
332
333 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
334
335 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) {
336 SIGADDSET(sq->sq_kill, signo);
337 goto out_set_bit;
338 }
339
340 /* directly insert the ksi, don't copy it */
341 if (si->ksi_flags & KSI_INS) {
342 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link);
343 si->ksi_sigq = sq;
344 goto out_set_bit;
345 }
346
347 if (__predict_false(ksiginfo_zone == NULL)) {
348 SIGADDSET(sq->sq_kill, signo);
349 goto out_set_bit;
350 }
351
352 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) {
353 signal_overflow++;
354 ret = EAGAIN;
355 } else if ((ksi = ksiginfo_alloc(0)) == NULL) {
356 signal_alloc_fail++;
357 ret = EAGAIN;
358 } else {
359 if (p != NULL)
360 p->p_pendingcnt++;
361 ksiginfo_copy(si, ksi);
362 ksi->ksi_signo = signo;
363 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link);
364 ksi->ksi_sigq = sq;
365 }
366
367 if ((si->ksi_flags & KSI_TRAP) != 0) {
368 if (ret != 0)
369 SIGADDSET(sq->sq_kill, signo);
370 ret = 0;
371 goto out_set_bit;
372 }
373
374 if (ret != 0)
375 return (ret);
376
377 out_set_bit:
378 SIGADDSET(sq->sq_signals, signo);
379 return (ret);
380 }
381
382 void
383 sigqueue_flush(sigqueue_t *sq)
384 {
385 struct proc *p = sq->sq_proc;
386 ksiginfo_t *ksi;
387
388 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
389
390 if (p != NULL)
391 PROC_LOCK_ASSERT(p, MA_OWNED);
392
393 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) {
394 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
395 ksi->ksi_sigq = NULL;
396 if (ksiginfo_tryfree(ksi) && p != NULL)
397 p->p_pendingcnt--;
398 }
399
400 SIGEMPTYSET(sq->sq_signals);
401 SIGEMPTYSET(sq->sq_kill);
402 }
403
404 void
405 sigqueue_collect_set(sigqueue_t *sq, sigset_t *set)
406 {
407 ksiginfo_t *ksi;
408
409 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
410
411 TAILQ_FOREACH(ksi, &sq->sq_list, ksi_link)
412 SIGADDSET(*set, ksi->ksi_signo);
413 SIGSETOR(*set, sq->sq_kill);
414 }
415
416 void
417 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, sigset_t *setp)
418 {
419 sigset_t tmp, set;
420 struct proc *p1, *p2;
421 ksiginfo_t *ksi, *next;
422
423 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited"));
424 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited"));
425 /*
426 * make a copy, this allows setp to point to src or dst
427 * sq_signals without trouble.
428 */
429 set = *setp;
430 p1 = src->sq_proc;
431 p2 = dst->sq_proc;
432 /* Move siginfo to target list */
433 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) {
434 if (SIGISMEMBER(set, ksi->ksi_signo)) {
435 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link);
436 if (p1 != NULL)
437 p1->p_pendingcnt--;
438 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link);
439 ksi->ksi_sigq = dst;
440 if (p2 != NULL)
441 p2->p_pendingcnt++;
442 }
443 }
444
445 /* Move pending bits to target list */
446 tmp = src->sq_kill;
447 SIGSETAND(tmp, set);
448 SIGSETOR(dst->sq_kill, tmp);
449 SIGSETNAND(src->sq_kill, tmp);
450
451 tmp = src->sq_signals;
452 SIGSETAND(tmp, set);
453 SIGSETOR(dst->sq_signals, tmp);
454 SIGSETNAND(src->sq_signals, tmp);
455
456 /* Finally, rescan src queue and set pending bits for it */
457 sigqueue_collect_set(src, &src->sq_signals);
458 }
459
460 void
461 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo)
462 {
463 sigset_t set;
464
465 SIGEMPTYSET(set);
466 SIGADDSET(set, signo);
467 sigqueue_move_set(src, dst, &set);
468 }
469
470 void
471 sigqueue_delete_set(sigqueue_t *sq, sigset_t *set)
472 {
473 struct proc *p = sq->sq_proc;
474 ksiginfo_t *ksi, *next;
475
476 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited"));
477
478 /* Remove siginfo queue */
479 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
480 if (SIGISMEMBER(*set, ksi->ksi_signo)) {
481 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
482 ksi->ksi_sigq = NULL;
483 if (ksiginfo_tryfree(ksi) && p != NULL)
484 p->p_pendingcnt--;
485 }
486 }
487 SIGSETNAND(sq->sq_kill, *set);
488 SIGSETNAND(sq->sq_signals, *set);
489 /* Finally, rescan queue and set pending bits for it */
490 sigqueue_collect_set(sq, &sq->sq_signals);
491 }
492
493 void
494 sigqueue_delete(sigqueue_t *sq, int signo)
495 {
496 sigset_t set;
497
498 SIGEMPTYSET(set);
499 SIGADDSET(set, signo);
500 sigqueue_delete_set(sq, &set);
501 }
502
503 /* Remove a set of signals for a process */
504 void
505 sigqueue_delete_set_proc(struct proc *p, sigset_t *set)
506 {
507 sigqueue_t worklist;
508 struct thread *td0;
509
510 PROC_LOCK_ASSERT(p, MA_OWNED);
511
512 sigqueue_init(&worklist, NULL);
513 sigqueue_move_set(&p->p_sigqueue, &worklist, set);
514
515 PROC_SLOCK(p);
516 FOREACH_THREAD_IN_PROC(p, td0)
517 sigqueue_move_set(&td0->td_sigqueue, &worklist, set);
518 PROC_SUNLOCK(p);
519
520 sigqueue_flush(&worklist);
521 }
522
523 void
524 sigqueue_delete_proc(struct proc *p, int signo)
525 {
526 sigset_t set;
527
528 SIGEMPTYSET(set);
529 SIGADDSET(set, signo);
530 sigqueue_delete_set_proc(p, &set);
531 }
532
533 void
534 sigqueue_delete_stopmask_proc(struct proc *p)
535 {
536 sigset_t set;
537
538 SIGEMPTYSET(set);
539 SIGADDSET(set, SIGSTOP);
540 SIGADDSET(set, SIGTSTP);
541 SIGADDSET(set, SIGTTIN);
542 SIGADDSET(set, SIGTTOU);
543 sigqueue_delete_set_proc(p, &set);
544 }
545
546 /*
547 * Determine signal that should be delivered to process p, the current
548 * process, 0 if none. If there is a pending stop signal with default
549 * action, the process stops in issignal().
550 */
551 int
552 cursig(struct thread *td)
553 {
554 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
555 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED);
556 THREAD_LOCK_ASSERT(td, MA_NOTOWNED);
557 return (SIGPENDING(td) ? issignal(td) : 0);
558 }
559
560 /*
561 * Arrange for ast() to handle unmasked pending signals on return to user
562 * mode. This must be called whenever a signal is added to td_sigqueue or
563 * unmasked in td_sigmask.
564 */
565 void
566 signotify(struct thread *td)
567 {
568 struct proc *p;
569 #ifdef KSE
570 sigset_t set, saved;
571 #else
572 sigset_t set;
573 #endif
574
575 p = td->td_proc;
576
577 PROC_LOCK_ASSERT(p, MA_OWNED);
578
579 /*
580 * If our mask changed we may have to move signal that were
581 * previously masked by all threads to our sigqueue.
582 */
583 set = p->p_sigqueue.sq_signals;
584 #ifdef KSE
585 if (p->p_flag & P_SA)
586 saved = p->p_sigqueue.sq_signals;
587 #endif
588 SIGSETNAND(set, td->td_sigmask);
589 if (! SIGISEMPTY(set))
590 sigqueue_move_set(&p->p_sigqueue, &td->td_sigqueue, &set);
591 if (SIGPENDING(td)) {
592 thread_lock(td);
593 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING;
594 thread_unlock(td);
595 }
596 #ifdef KSE
597 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) {
598 if (!SIGSETEQ(saved, p->p_sigqueue.sq_signals)) {
599 /* pending set changed */
600 p->p_flag |= P_SIGEVENT;
601 wakeup(&p->p_siglist);
602 }
603 }
604 #endif
605 }
606
607 int
608 sigonstack(size_t sp)
609 {
610 struct thread *td = curthread;
611
612 return ((td->td_pflags & TDP_ALTSTACK) ?
613 #if defined(COMPAT_43)
614 ((td->td_sigstk.ss_size == 0) ?
615 (td->td_sigstk.ss_flags & SS_ONSTACK) :
616 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size))
617 #else
618 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)
619 #endif
620 : 0);
621 }
622
623 static __inline int
624 sigprop(int sig)
625 {
626
627 if (sig > 0 && sig < NSIG)
628 return (sigproptbl[_SIG_IDX(sig)]);
629 return (0);
630 }
631
632 int
633 sig_ffs(sigset_t *set)
634 {
635 int i;
636
637 for (i = 0; i < _SIG_WORDS; i++)
638 if (set->__bits[i])
639 return (ffs(set->__bits[i]) + (i * 32));
640 return (0);
641 }
642
643 /*
644 * kern_sigaction
645 * sigaction
646 * freebsd4_sigaction
647 * osigaction
648 */
649 int
650 kern_sigaction(td, sig, act, oact, flags)
651 struct thread *td;
652 register int sig;
653 struct sigaction *act, *oact;
654 int flags;
655 {
656 struct sigacts *ps;
657 struct proc *p = td->td_proc;
658
659 if (!_SIG_VALID(sig))
660 return (EINVAL);
661
662 PROC_LOCK(p);
663 ps = p->p_sigacts;
664 mtx_lock(&ps->ps_mtx);
665 if (oact) {
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 oact->sa_sigaction =
679 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)];
680 } else
681 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
682 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP)
683 oact->sa_flags |= SA_NOCLDSTOP;
684 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT)
685 oact->sa_flags |= SA_NOCLDWAIT;
686 }
687 if (act) {
688 if ((sig == SIGKILL || sig == SIGSTOP) &&
689 act->sa_handler != SIG_DFL) {
690 mtx_unlock(&ps->ps_mtx);
691 PROC_UNLOCK(p);
692 return (EINVAL);
693 }
694
695 /*
696 * Change setting atomically.
697 */
698
699 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
700 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
701 if (act->sa_flags & SA_SIGINFO) {
702 ps->ps_sigact[_SIG_IDX(sig)] =
703 (__sighandler_t *)act->sa_sigaction;
704 SIGADDSET(ps->ps_siginfo, sig);
705 } else {
706 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
707 SIGDELSET(ps->ps_siginfo, sig);
708 }
709 if (!(act->sa_flags & SA_RESTART))
710 SIGADDSET(ps->ps_sigintr, sig);
711 else
712 SIGDELSET(ps->ps_sigintr, sig);
713 if (act->sa_flags & SA_ONSTACK)
714 SIGADDSET(ps->ps_sigonstack, sig);
715 else
716 SIGDELSET(ps->ps_sigonstack, sig);
717 if (act->sa_flags & SA_RESETHAND)
718 SIGADDSET(ps->ps_sigreset, sig);
719 else
720 SIGDELSET(ps->ps_sigreset, sig);
721 if (act->sa_flags & SA_NODEFER)
722 SIGADDSET(ps->ps_signodefer, sig);
723 else
724 SIGDELSET(ps->ps_signodefer, sig);
725 if (sig == SIGCHLD) {
726 if (act->sa_flags & SA_NOCLDSTOP)
727 ps->ps_flag |= PS_NOCLDSTOP;
728 else
729 ps->ps_flag &= ~PS_NOCLDSTOP;
730 if (act->sa_flags & SA_NOCLDWAIT) {
731 /*
732 * Paranoia: since SA_NOCLDWAIT is implemented
733 * by reparenting the dying child to PID 1 (and
734 * trust it to reap the zombie), PID 1 itself
735 * is forbidden to set SA_NOCLDWAIT.
736 */
737 if (p->p_pid == 1)
738 ps->ps_flag &= ~PS_NOCLDWAIT;
739 else
740 ps->ps_flag |= PS_NOCLDWAIT;
741 } else
742 ps->ps_flag &= ~PS_NOCLDWAIT;
743 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
744 ps->ps_flag |= PS_CLDSIGIGN;
745 else
746 ps->ps_flag &= ~PS_CLDSIGIGN;
747 }
748 /*
749 * Set bit in ps_sigignore for signals that are set to SIG_IGN,
750 * and for signals set to SIG_DFL where the default is to
751 * ignore. However, don't put SIGCONT in ps_sigignore, as we
752 * have to restart the process.
753 */
754 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
755 (sigprop(sig) & SA_IGNORE &&
756 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
757 #ifdef KSE
758 if ((p->p_flag & P_SA) &&
759 SIGISMEMBER(p->p_sigqueue.sq_signals, sig)) {
760 p->p_flag |= P_SIGEVENT;
761 wakeup(&p->p_siglist);
762 }
763 #endif
764 /* never to be seen again */
765 sigqueue_delete_proc(p, sig);
766 if (sig != SIGCONT)
767 /* easier in psignal */
768 SIGADDSET(ps->ps_sigignore, sig);
769 SIGDELSET(ps->ps_sigcatch, sig);
770 } else {
771 SIGDELSET(ps->ps_sigignore, sig);
772 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
773 SIGDELSET(ps->ps_sigcatch, sig);
774 else
775 SIGADDSET(ps->ps_sigcatch, sig);
776 }
777 #ifdef COMPAT_FREEBSD4
778 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
779 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
780 (flags & KSA_FREEBSD4) == 0)
781 SIGDELSET(ps->ps_freebsd4, sig);
782 else
783 SIGADDSET(ps->ps_freebsd4, sig);
784 #endif
785 #ifdef COMPAT_43
786 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
787 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
788 (flags & KSA_OSIGSET) == 0)
789 SIGDELSET(ps->ps_osigset, sig);
790 else
791 SIGADDSET(ps->ps_osigset, sig);
792 #endif
793 }
794 mtx_unlock(&ps->ps_mtx);
795 PROC_UNLOCK(p);
796 return (0);
797 }
798
799 #ifndef _SYS_SYSPROTO_H_
800 struct sigaction_args {
801 int sig;
802 struct sigaction *act;
803 struct sigaction *oact;
804 };
805 #endif
806 int
807 sigaction(td, uap)
808 struct thread *td;
809 register struct sigaction_args *uap;
810 {
811 struct sigaction act, oact;
812 register struct sigaction *actp, *oactp;
813 int error;
814
815 actp = (uap->act != NULL) ? &act : NULL;
816 oactp = (uap->oact != NULL) ? &oact : NULL;
817 if (actp) {
818 error = copyin(uap->act, actp, sizeof(act));
819 if (error)
820 return (error);
821 }
822 error = kern_sigaction(td, uap->sig, actp, oactp, 0);
823 if (oactp && !error)
824 error = copyout(oactp, uap->oact, sizeof(oact));
825 return (error);
826 }
827
828 #ifdef COMPAT_FREEBSD4
829 #ifndef _SYS_SYSPROTO_H_
830 struct freebsd4_sigaction_args {
831 int sig;
832 struct sigaction *act;
833 struct sigaction *oact;
834 };
835 #endif
836 int
837 freebsd4_sigaction(td, uap)
838 struct thread *td;
839 register struct freebsd4_sigaction_args *uap;
840 {
841 struct sigaction act, oact;
842 register struct sigaction *actp, *oactp;
843 int error;
844
845
846 actp = (uap->act != NULL) ? &act : NULL;
847 oactp = (uap->oact != NULL) ? &oact : NULL;
848 if (actp) {
849 error = copyin(uap->act, actp, sizeof(act));
850 if (error)
851 return (error);
852 }
853 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4);
854 if (oactp && !error)
855 error = copyout(oactp, uap->oact, sizeof(oact));
856 return (error);
857 }
858 #endif /* COMAPT_FREEBSD4 */
859
860 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
861 #ifndef _SYS_SYSPROTO_H_
862 struct osigaction_args {
863 int signum;
864 struct osigaction *nsa;
865 struct osigaction *osa;
866 };
867 #endif
868 int
869 osigaction(td, uap)
870 struct thread *td;
871 register struct osigaction_args *uap;
872 {
873 struct osigaction sa;
874 struct sigaction nsa, osa;
875 register struct sigaction *nsap, *osap;
876 int error;
877
878 if (uap->signum <= 0 || uap->signum >= ONSIG)
879 return (EINVAL);
880
881 nsap = (uap->nsa != NULL) ? &nsa : NULL;
882 osap = (uap->osa != NULL) ? &osa : NULL;
883
884 if (nsap) {
885 error = copyin(uap->nsa, &sa, sizeof(sa));
886 if (error)
887 return (error);
888 nsap->sa_handler = sa.sa_handler;
889 nsap->sa_flags = sa.sa_flags;
890 OSIG2SIG(sa.sa_mask, nsap->sa_mask);
891 }
892 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
893 if (osap && !error) {
894 sa.sa_handler = osap->sa_handler;
895 sa.sa_flags = osap->sa_flags;
896 SIG2OSIG(osap->sa_mask, sa.sa_mask);
897 error = copyout(&sa, uap->osa, sizeof(sa));
898 }
899 return (error);
900 }
901
902 #if !defined(__i386__)
903 /* Avoid replicating the same stub everywhere */
904 int
905 osigreturn(td, uap)
906 struct thread *td;
907 struct osigreturn_args *uap;
908 {
909
910 return (nosys(td, (struct nosys_args *)uap));
911 }
912 #endif
913 #endif /* COMPAT_43 */
914
915 /*
916 * Initialize signal state for process 0;
917 * set to ignore signals that are ignored by default.
918 */
919 void
920 siginit(p)
921 struct proc *p;
922 {
923 register int i;
924 struct sigacts *ps;
925
926 PROC_LOCK(p);
927 ps = p->p_sigacts;
928 mtx_lock(&ps->ps_mtx);
929 for (i = 1; i <= NSIG; i++)
930 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
931 SIGADDSET(ps->ps_sigignore, i);
932 mtx_unlock(&ps->ps_mtx);
933 PROC_UNLOCK(p);
934 }
935
936 /*
937 * Reset signals for an exec of the specified process.
938 */
939 void
940 execsigs(struct proc *p)
941 {
942 struct sigacts *ps;
943 int sig;
944 struct thread *td;
945
946 /*
947 * Reset caught signals. Held signals remain held
948 * through td_sigmask (unless they were caught,
949 * and are now ignored by default).
950 */
951 PROC_LOCK_ASSERT(p, MA_OWNED);
952 td = FIRST_THREAD_IN_PROC(p);
953 ps = p->p_sigacts;
954 mtx_lock(&ps->ps_mtx);
955 while (SIGNOTEMPTY(ps->ps_sigcatch)) {
956 sig = sig_ffs(&ps->ps_sigcatch);
957 SIGDELSET(ps->ps_sigcatch, sig);
958 if (sigprop(sig) & SA_IGNORE) {
959 if (sig != SIGCONT)
960 SIGADDSET(ps->ps_sigignore, sig);
961 sigqueue_delete_proc(p, sig);
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 context 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 int wakeup_swapper;
2051
2052 PROC_LOCK_ASSERT(p, MA_OWNED);
2053
2054 if (!_SIG_VALID(sig))
2055 #ifdef KSE
2056 panic("do_tdsignal(): invalid signal %d", sig);
2057 #else
2058 panic("tdsignal(): invalid signal %d", sig);
2059 #endif
2060
2061 #ifdef KSE
2062 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("do_tdsignal: ksi on queue"));
2063 #else
2064 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("tdsignal: ksi on queue"));
2065 #endif
2066
2067 /*
2068 * IEEE Std 1003.1-2001: return success when killing a zombie.
2069 */
2070 if (p->p_state == PRS_ZOMBIE) {
2071 if (ksi && (ksi->ksi_flags & KSI_INS))
2072 ksiginfo_tryfree(ksi);
2073 return (ret);
2074 }
2075
2076 ps = p->p_sigacts;
2077 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig);
2078 prop = sigprop(sig);
2079
2080 /*
2081 * If the signal is blocked and not destined for this thread, then
2082 * assign it to the process so that we can find it later in the first
2083 * thread that unblocks it. Otherwise, assign it to this thread now.
2084 */
2085 if (td == NULL) {
2086 td = sigtd(p, sig, prop);
2087 if (SIGISMEMBER(td->td_sigmask, sig))
2088 sigqueue = &p->p_sigqueue;
2089 else
2090 sigqueue = &td->td_sigqueue;
2091 } else {
2092 KASSERT(td->td_proc == p, ("invalid thread"));
2093 sigqueue = &td->td_sigqueue;
2094 }
2095
2096 /*
2097 * If the signal is being ignored,
2098 * then we forget about it immediately.
2099 * (Note: we don't set SIGCONT in ps_sigignore,
2100 * and if it is set to SIG_IGN,
2101 * action will be SIG_DFL here.)
2102 */
2103 mtx_lock(&ps->ps_mtx);
2104 if (SIGISMEMBER(ps->ps_sigignore, sig)) {
2105 mtx_unlock(&ps->ps_mtx);
2106 if (ksi && (ksi->ksi_flags & KSI_INS))
2107 ksiginfo_tryfree(ksi);
2108 return (ret);
2109 }
2110 if (SIGISMEMBER(td->td_sigmask, sig))
2111 action = SIG_HOLD;
2112 else if (SIGISMEMBER(ps->ps_sigcatch, sig))
2113 action = SIG_CATCH;
2114 else
2115 action = SIG_DFL;
2116 if (SIGISMEMBER(ps->ps_sigintr, sig))
2117 intrval = EINTR;
2118 else
2119 intrval = ERESTART;
2120 mtx_unlock(&ps->ps_mtx);
2121
2122 if (prop & SA_CONT)
2123 sigqueue_delete_stopmask_proc(p);
2124 else if (prop & SA_STOP) {
2125 /*
2126 * If sending a tty stop signal to a member of an orphaned
2127 * process group, discard the signal here if the action
2128 * is default; don't stop the process below if sleeping,
2129 * and don't clear any pending SIGCONT.
2130 */
2131 if ((prop & SA_TTYSTOP) &&
2132 (p->p_pgrp->pg_jobc == 0) &&
2133 (action == SIG_DFL)) {
2134 if (ksi && (ksi->ksi_flags & KSI_INS))
2135 ksiginfo_tryfree(ksi);
2136 return (ret);
2137 }
2138 sigqueue_delete_proc(p, SIGCONT);
2139 if (p->p_flag & P_CONTINUED) {
2140 p->p_flag &= ~P_CONTINUED;
2141 PROC_LOCK(p->p_pptr);
2142 sigqueue_take(p->p_ksi);
2143 PROC_UNLOCK(p->p_pptr);
2144 }
2145 }
2146
2147 ret = sigqueue_add(sigqueue, sig, ksi);
2148 if (ret != 0)
2149 return (ret);
2150 signotify(td);
2151 /*
2152 * Defer further processing for signals which are held,
2153 * except that stopped processes must be continued by SIGCONT.
2154 */
2155 if (action == SIG_HOLD &&
2156 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG)))
2157 return (ret);
2158 /*
2159 * SIGKILL: Remove procfs STOPEVENTs.
2160 */
2161 if (sig == SIGKILL) {
2162 /* from procfs_ioctl.c: PIOCBIC */
2163 p->p_stops = 0;
2164 /* from procfs_ioctl.c: PIOCCONT */
2165 p->p_step = 0;
2166 wakeup(&p->p_step);
2167 }
2168 /*
2169 * Some signals have a process-wide effect and a per-thread
2170 * component. Most processing occurs when the process next
2171 * tries to cross the user boundary, however there are some
2172 * times when processing needs to be done immediatly, such as
2173 * waking up threads so that they can cross the user boundary.
2174 * We try do the per-process part here.
2175 */
2176 PROC_SLOCK(p);
2177 if (P_SHOULDSTOP(p)) {
2178 /*
2179 * The process is in stopped mode. All the threads should be
2180 * either winding down or already on the suspended queue.
2181 */
2182 if (p->p_flag & P_TRACED) {
2183 /*
2184 * The traced process is already stopped,
2185 * so no further action is necessary.
2186 * No signal can restart us.
2187 */
2188 PROC_SUNLOCK(p);
2189 goto out;
2190 }
2191
2192 if (sig == SIGKILL) {
2193 /*
2194 * SIGKILL sets process running.
2195 * It will die elsewhere.
2196 * All threads must be restarted.
2197 */
2198 p->p_flag &= ~P_STOPPED_SIG;
2199 goto runfast;
2200 }
2201
2202 if (prop & SA_CONT) {
2203 /*
2204 * If SIGCONT is default (or ignored), we continue the
2205 * process but don't leave the signal in sigqueue as
2206 * it has no further action. If SIGCONT is held, we
2207 * continue the process and leave the signal in
2208 * sigqueue. If the process catches SIGCONT, let it
2209 * handle the signal itself. If it isn't waiting on
2210 * an event, it goes back to run state.
2211 * Otherwise, process goes back to sleep state.
2212 */
2213 p->p_flag &= ~P_STOPPED_SIG;
2214 if (p->p_numthreads == p->p_suspcount) {
2215 PROC_SUNLOCK(p);
2216 p->p_flag |= P_CONTINUED;
2217 p->p_xstat = SIGCONT;
2218 PROC_LOCK(p->p_pptr);
2219 childproc_continued(p);
2220 PROC_UNLOCK(p->p_pptr);
2221 PROC_SLOCK(p);
2222 }
2223 if (action == SIG_DFL) {
2224 thread_unsuspend(p);
2225 PROC_SUNLOCK(p);
2226 sigqueue_delete(sigqueue, sig);
2227 goto out;
2228 }
2229 if (action == SIG_CATCH) {
2230 #ifdef KSE
2231 /*
2232 * The process wants to catch it so it needs
2233 * to run at least one thread, but which one?
2234 * It would seem that the answer would be to
2235 * run an upcall in the next KSE to run, and
2236 * deliver the signal that way. In a NON KSE
2237 * process, we need to make sure that the
2238 * single thread is runnable asap.
2239 * XXXKSE for now however, make them all run.
2240 */
2241 #endif
2242 /*
2243 * The process wants to catch it so it needs
2244 * to run at least one thread, but which one?
2245 */
2246 goto runfast;
2247 }
2248 /*
2249 * The signal is not ignored or caught.
2250 */
2251 thread_unsuspend(p);
2252 PROC_SUNLOCK(p);
2253 goto out;
2254 }
2255
2256 if (prop & SA_STOP) {
2257 /*
2258 * Already stopped, don't need to stop again
2259 * (If we did the shell could get confused).
2260 * Just make sure the signal STOP bit set.
2261 */
2262 PROC_SUNLOCK(p);
2263 p->p_flag |= P_STOPPED_SIG;
2264 sigqueue_delete(sigqueue, sig);
2265 goto out;
2266 }
2267
2268 /*
2269 * All other kinds of signals:
2270 * If a thread is sleeping interruptibly, simulate a
2271 * wakeup so that when it is continued it will be made
2272 * runnable and can look at the signal. However, don't make
2273 * the PROCESS runnable, leave it stopped.
2274 * It may run a bit until it hits a thread_suspend_check().
2275 */
2276 wakeup_swapper = 0;
2277 thread_lock(td);
2278 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR))
2279 wakeup_swapper = sleepq_abort(td, intrval);
2280 thread_unlock(td);
2281 PROC_SUNLOCK(p);
2282 if (wakeup_swapper)
2283 kick_proc0();
2284 goto out;
2285 /*
2286 * Mutexes are short lived. Threads waiting on them will
2287 * hit thread_suspend_check() soon.
2288 */
2289 } else if (p->p_state == PRS_NORMAL) {
2290 if (p->p_flag & P_TRACED || action == SIG_CATCH) {
2291 thread_lock(td);
2292 wakeup_swapper = tdsigwakeup(td, sig, action, intrval);
2293 thread_unlock(td);
2294 PROC_SUNLOCK(p);
2295 if (wakeup_swapper)
2296 kick_proc0();
2297 goto out;
2298 }
2299
2300 MPASS(action == SIG_DFL);
2301
2302 if (prop & SA_STOP) {
2303 if (p->p_flag & P_PPWAIT) {
2304 PROC_SUNLOCK(p);
2305 goto out;
2306 }
2307 p->p_flag |= P_STOPPED_SIG;
2308 p->p_xstat = sig;
2309 sig_suspend_threads(td, p, 1);
2310 if (p->p_numthreads == p->p_suspcount) {
2311 /*
2312 * only thread sending signal to another
2313 * process can reach here, if thread is sending
2314 * signal to its process, because thread does
2315 * not suspend itself here, p_numthreads
2316 * should never be equal to p_suspcount.
2317 */
2318 thread_stopped(p);
2319 PROC_SUNLOCK(p);
2320 sigqueue_delete_proc(p, p->p_xstat);
2321 } else
2322 PROC_SUNLOCK(p);
2323 goto out;
2324 }
2325 else
2326 goto runfast;
2327 /* NOTREACHED */
2328 } else {
2329 /* Not in "NORMAL" state. discard the signal. */
2330 PROC_SUNLOCK(p);
2331 sigqueue_delete(sigqueue, sig);
2332 goto out;
2333 }
2334
2335 /*
2336 * The process is not stopped so we need to apply the signal to all the
2337 * running threads.
2338 */
2339
2340 runfast:
2341 thread_lock(td);
2342 wakeup_swapper = tdsigwakeup(td, sig, action, intrval);
2343 thread_unlock(td);
2344 thread_unsuspend(p);
2345 PROC_SUNLOCK(p);
2346 if (wakeup_swapper)
2347 kick_proc0();
2348 out:
2349 /* If we jump here, proc slock should not be owned. */
2350 PROC_SLOCK_ASSERT(p, MA_NOTOWNED);
2351 return (ret);
2352 }
2353
2354 /*
2355 * The force of a signal has been directed against a single
2356 * thread. We need to see what we can do about knocking it
2357 * out of any sleep it may be in etc.
2358 */
2359 static int
2360 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval)
2361 {
2362 struct proc *p = td->td_proc;
2363 register int prop;
2364 int wakeup_swapper;
2365
2366 wakeup_swapper = 0;
2367 PROC_LOCK_ASSERT(p, MA_OWNED);
2368 PROC_SLOCK_ASSERT(p, MA_OWNED);
2369 THREAD_LOCK_ASSERT(td, MA_OWNED);
2370 prop = sigprop(sig);
2371
2372 /*
2373 * Bring the priority of a thread up if we want it to get
2374 * killed in this lifetime.
2375 */
2376 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER)
2377 sched_prio(td, PUSER);
2378
2379 if (TD_ON_SLEEPQ(td)) {
2380 /*
2381 * If thread is sleeping uninterruptibly
2382 * we can't interrupt the sleep... the signal will
2383 * be noticed when the process returns through
2384 * trap() or syscall().
2385 */
2386 if ((td->td_flags & TDF_SINTR) == 0)
2387 return (0);
2388 /*
2389 * If SIGCONT is default (or ignored) and process is
2390 * asleep, we are finished; the process should not
2391 * be awakened.
2392 */
2393 if ((prop & SA_CONT) && action == SIG_DFL) {
2394 thread_unlock(td);
2395 PROC_SUNLOCK(p);
2396 sigqueue_delete(&p->p_sigqueue, sig);
2397 /*
2398 * It may be on either list in this state.
2399 * Remove from both for now.
2400 */
2401 sigqueue_delete(&td->td_sigqueue, sig);
2402 PROC_SLOCK(p);
2403 thread_lock(td);
2404 return (0);
2405 }
2406
2407 /*
2408 * Give low priority threads a better chance to run.
2409 */
2410 if (td->td_priority > PUSER)
2411 sched_prio(td, PUSER);
2412
2413 wakeup_swapper = sleepq_abort(td, intrval);
2414 } else {
2415 /*
2416 * Other states do nothing with the signal immediately,
2417 * other than kicking ourselves if we are running.
2418 * It will either never be noticed, or noticed very soon.
2419 */
2420 #ifdef SMP
2421 if (TD_IS_RUNNING(td) && td != curthread)
2422 forward_signal(td);
2423 #endif
2424 }
2425 return (wakeup_swapper);
2426 }
2427
2428 static void
2429 sig_suspend_threads(struct thread *td, struct proc *p, int sending)
2430 {
2431 struct thread *td2;
2432
2433 PROC_LOCK_ASSERT(p, MA_OWNED);
2434 PROC_SLOCK_ASSERT(p, MA_OWNED);
2435
2436 FOREACH_THREAD_IN_PROC(p, td2) {
2437 thread_lock(td2);
2438 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) &&
2439 (td2->td_flags & TDF_SINTR) &&
2440 !TD_IS_SUSPENDED(td2)) {
2441 thread_suspend_one(td2);
2442 } else {
2443 if (sending || td != td2)
2444 td2->td_flags |= TDF_ASTPENDING;
2445 #ifdef SMP
2446 if (TD_IS_RUNNING(td2) && td2 != td)
2447 forward_signal(td2);
2448 #endif
2449 }
2450 thread_unlock(td2);
2451 }
2452 }
2453
2454 int
2455 ptracestop(struct thread *td, int sig)
2456 {
2457 struct proc *p = td->td_proc;
2458
2459 PROC_LOCK_ASSERT(p, MA_OWNED);
2460 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
2461 &p->p_mtx.lock_object, "Stopping for traced signal");
2462
2463 thread_lock(td);
2464 td->td_flags |= TDF_XSIG;
2465 thread_unlock(td);
2466 td->td_xsig = sig;
2467 PROC_SLOCK(p);
2468 while ((p->p_flag & P_TRACED) && (td->td_flags & TDF_XSIG)) {
2469 if (p->p_flag & P_SINGLE_EXIT) {
2470 thread_lock(td);
2471 td->td_flags &= ~TDF_XSIG;
2472 thread_unlock(td);
2473 PROC_SUNLOCK(p);
2474 return (sig);
2475 }
2476 /*
2477 * Just make wait() to work, the last stopped thread
2478 * will win.
2479 */
2480 p->p_xstat = sig;
2481 p->p_xthread = td;
2482 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE);
2483 sig_suspend_threads(td, p, 0);
2484 stopme:
2485 thread_suspend_switch(td);
2486 if (!(p->p_flag & P_TRACED)) {
2487 break;
2488 }
2489 if (td->td_flags & TDF_DBSUSPEND) {
2490 if (p->p_flag & P_SINGLE_EXIT)
2491 break;
2492 goto stopme;
2493 }
2494 }
2495 PROC_SUNLOCK(p);
2496 return (td->td_xsig);
2497 }
2498
2499 /*
2500 * If the current process has received a signal (should be caught or cause
2501 * termination, should interrupt current syscall), return the signal number.
2502 * Stop signals with default action are processed immediately, then cleared;
2503 * they aren't returned. This is checked after each entry to the system for
2504 * a syscall or trap (though this can usually be done without calling issignal
2505 * by checking the pending signal masks in cursig.) The normal call
2506 * sequence is
2507 *
2508 * while (sig = cursig(curthread))
2509 * postsig(sig);
2510 */
2511 static int
2512 issignal(td)
2513 struct thread *td;
2514 {
2515 struct proc *p;
2516 struct sigacts *ps;
2517 sigset_t sigpending;
2518 int sig, prop, newsig;
2519
2520 p = td->td_proc;
2521 ps = p->p_sigacts;
2522 mtx_assert(&ps->ps_mtx, MA_OWNED);
2523 PROC_LOCK_ASSERT(p, MA_OWNED);
2524 for (;;) {
2525 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
2526
2527 sigpending = td->td_sigqueue.sq_signals;
2528 SIGSETNAND(sigpending, td->td_sigmask);
2529
2530 if (p->p_flag & P_PPWAIT)
2531 SIG_STOPSIGMASK(sigpending);
2532 if (SIGISEMPTY(sigpending)) /* no signal to send */
2533 return (0);
2534 sig = sig_ffs(&sigpending);
2535
2536 if (p->p_stops & S_SIG) {
2537 mtx_unlock(&ps->ps_mtx);
2538 stopevent(p, S_SIG, sig);
2539 mtx_lock(&ps->ps_mtx);
2540 }
2541
2542 /*
2543 * We should see pending but ignored signals
2544 * only if P_TRACED was on when they were posted.
2545 */
2546 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) {
2547 sigqueue_delete(&td->td_sigqueue, sig);
2548 #ifdef KSE
2549 if (td->td_pflags & TDP_SA)
2550 SIGADDSET(td->td_sigmask, sig);
2551 #endif
2552 continue;
2553 }
2554 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) {
2555 /*
2556 * If traced, always stop.
2557 */
2558 mtx_unlock(&ps->ps_mtx);
2559 newsig = ptracestop(td, sig);
2560 mtx_lock(&ps->ps_mtx);
2561
2562 #ifdef KSE
2563 if (td->td_pflags & TDP_SA)
2564 SIGADDSET(td->td_sigmask, sig);
2565
2566 #endif
2567 if (sig != newsig) {
2568 ksiginfo_t ksi;
2569 /*
2570 * clear old signal.
2571 * XXX shrug off debugger, it causes siginfo to
2572 * be thrown away.
2573 */
2574 sigqueue_get(&td->td_sigqueue, sig, &ksi);
2575
2576 /*
2577 * If parent wants us to take the signal,
2578 * then it will leave it in p->p_xstat;
2579 * otherwise we just look for signals again.
2580 */
2581 if (newsig == 0)
2582 continue;
2583 sig = newsig;
2584
2585 /*
2586 * Put the new signal into td_sigqueue. If the
2587 * signal is being masked, look for other signals.
2588 */
2589 SIGADDSET(td->td_sigqueue.sq_signals, sig);
2590 #ifdef KSE
2591 if (td->td_pflags & TDP_SA)
2592 SIGDELSET(td->td_sigmask, sig);
2593 #endif
2594 if (SIGISMEMBER(td->td_sigmask, sig))
2595 continue;
2596 signotify(td);
2597 }
2598
2599 /*
2600 * If the traced bit got turned off, go back up
2601 * to the top to rescan signals. This ensures
2602 * that p_sig* and p_sigact are consistent.
2603 */
2604 if ((p->p_flag & P_TRACED) == 0)
2605 continue;
2606 }
2607
2608 prop = sigprop(sig);
2609
2610 /*
2611 * Decide whether the signal should be returned.
2612 * Return the signal's number, or fall through
2613 * to clear it from the pending mask.
2614 */
2615 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
2616
2617 case (intptr_t)SIG_DFL:
2618 /*
2619 * Don't take default actions on system processes.
2620 */
2621 if (p->p_pid <= 1) {
2622 #ifdef DIAGNOSTIC
2623 /*
2624 * Are you sure you want to ignore SIGSEGV
2625 * in init? XXX
2626 */
2627 printf("Process (pid %lu) got signal %d\n",
2628 (u_long)p->p_pid, sig);
2629 #endif
2630 break; /* == ignore */
2631 }
2632 /*
2633 * If there is a pending stop signal to process
2634 * with default action, stop here,
2635 * then clear the signal. However,
2636 * if process is member of an orphaned
2637 * process group, ignore tty stop signals.
2638 */
2639 if (prop & SA_STOP) {
2640 if (p->p_flag & P_TRACED ||
2641 (p->p_pgrp->pg_jobc == 0 &&
2642 prop & SA_TTYSTOP))
2643 break; /* == ignore */
2644 mtx_unlock(&ps->ps_mtx);
2645 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
2646 &p->p_mtx.lock_object, "Catching SIGSTOP");
2647 p->p_flag |= P_STOPPED_SIG;
2648 p->p_xstat = sig;
2649 PROC_SLOCK(p);
2650 sig_suspend_threads(td, p, 0);
2651 thread_suspend_switch(td);
2652 PROC_SUNLOCK(p);
2653 mtx_lock(&ps->ps_mtx);
2654 break;
2655 } else if (prop & SA_IGNORE) {
2656 /*
2657 * Except for SIGCONT, shouldn't get here.
2658 * Default action is to ignore; drop it.
2659 */
2660 break; /* == ignore */
2661 } else
2662 return (sig);
2663 /*NOTREACHED*/
2664
2665 case (intptr_t)SIG_IGN:
2666 /*
2667 * Masking above should prevent us ever trying
2668 * to take action on an ignored signal other
2669 * than SIGCONT, unless process is traced.
2670 */
2671 if ((prop & SA_CONT) == 0 &&
2672 (p->p_flag & P_TRACED) == 0)
2673 printf("issignal\n");
2674 break; /* == ignore */
2675
2676 default:
2677 /*
2678 * This signal has an action, let
2679 * postsig() process it.
2680 */
2681 return (sig);
2682 }
2683 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */
2684 }
2685 /* NOTREACHED */
2686 }
2687
2688 void
2689 thread_stopped(struct proc *p)
2690 {
2691 int n;
2692
2693 PROC_LOCK_ASSERT(p, MA_OWNED);
2694 PROC_SLOCK_ASSERT(p, MA_OWNED);
2695 n = p->p_suspcount;
2696 if (p == curproc)
2697 n++;
2698 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) {
2699 PROC_SUNLOCK(p);
2700 p->p_flag &= ~P_WAITED;
2701 PROC_LOCK(p->p_pptr);
2702 childproc_stopped(p, (p->p_flag & P_TRACED) ?
2703 CLD_TRAPPED : CLD_STOPPED);
2704 PROC_UNLOCK(p->p_pptr);
2705 PROC_SLOCK(p);
2706 }
2707 }
2708
2709 /*
2710 * Take the action for the specified signal
2711 * from the current set of pending signals.
2712 */
2713 void
2714 postsig(sig)
2715 register int sig;
2716 {
2717 struct thread *td = curthread;
2718 register struct proc *p = td->td_proc;
2719 struct sigacts *ps;
2720 sig_t action;
2721 ksiginfo_t ksi;
2722 sigset_t returnmask;
2723 int code;
2724
2725 KASSERT(sig != 0, ("postsig"));
2726
2727 PROC_LOCK_ASSERT(p, MA_OWNED);
2728 ps = p->p_sigacts;
2729 mtx_assert(&ps->ps_mtx, MA_OWNED);
2730 ksiginfo_init(&ksi);
2731 sigqueue_get(&td->td_sigqueue, sig, &ksi);
2732 ksi.ksi_signo = sig;
2733 if (ksi.ksi_code == SI_TIMER)
2734 itimer_accept(p, ksi.ksi_timerid, &ksi);
2735 action = ps->ps_sigact[_SIG_IDX(sig)];
2736 #ifdef KTRACE
2737 if (KTRPOINT(td, KTR_PSIG))
2738 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ?
2739 &td->td_oldsigmask : &td->td_sigmask, 0);
2740 #endif
2741 if (p->p_stops & S_SIG) {
2742 mtx_unlock(&ps->ps_mtx);
2743 stopevent(p, S_SIG, sig);
2744 mtx_lock(&ps->ps_mtx);
2745 }
2746
2747 #ifdef KSE
2748 if (!(td->td_pflags & TDP_SA) && action == SIG_DFL) {
2749 #else
2750 if (action == SIG_DFL) {
2751 #endif
2752 /*
2753 * Default action, where the default is to kill
2754 * the process. (Other cases were ignored above.)
2755 */
2756 mtx_unlock(&ps->ps_mtx);
2757 sigexit(td, sig);
2758 /* NOTREACHED */
2759 } else {
2760 #ifdef KSE
2761 if (td->td_pflags & TDP_SA) {
2762 if (sig == SIGKILL) {
2763 mtx_unlock(&ps->ps_mtx);
2764 sigexit(td, sig);
2765 }
2766 }
2767
2768 #endif
2769 /*
2770 * If we get here, the signal must be caught.
2771 */
2772 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig),
2773 ("postsig action"));
2774 /*
2775 * Set the new mask value and also defer further
2776 * occurrences of this signal.
2777 *
2778 * Special case: user has done a sigsuspend. Here the
2779 * current mask is not of interest, but rather the
2780 * mask from before the sigsuspend is what we want
2781 * restored after the signal processing is completed.
2782 */
2783 if (td->td_pflags & TDP_OLDMASK) {
2784 returnmask = td->td_oldsigmask;
2785 td->td_pflags &= ~TDP_OLDMASK;
2786 } else
2787 returnmask = td->td_sigmask;
2788
2789 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
2790 if (!SIGISMEMBER(ps->ps_signodefer, sig))
2791 SIGADDSET(td->td_sigmask, sig);
2792
2793 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
2794 /*
2795 * See kern_sigaction() for origin of this code.
2796 */
2797 SIGDELSET(ps->ps_sigcatch, sig);
2798 if (sig != SIGCONT &&
2799 sigprop(sig) & SA_IGNORE)
2800 SIGADDSET(ps->ps_sigignore, sig);
2801 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
2802 }
2803 td->td_ru.ru_nsignals++;
2804 if (p->p_sig != sig) {
2805 code = 0;
2806 } else {
2807 code = p->p_code;
2808 p->p_code = 0;
2809 p->p_sig = 0;
2810 }
2811 #ifdef KSE
2812 if (td->td_pflags & TDP_SA)
2813 thread_signal_add(curthread, &ksi);
2814 else
2815 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask);
2816 #else
2817 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask);
2818 #endif
2819 }
2820 }
2821
2822 /*
2823 * Kill the current process for stated reason.
2824 */
2825 void
2826 killproc(p, why)
2827 struct proc *p;
2828 char *why;
2829 {
2830
2831 PROC_LOCK_ASSERT(p, MA_OWNED);
2832 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)",
2833 p, p->p_pid, p->p_comm);
2834 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm,
2835 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
2836 psignal(p, SIGKILL);
2837 }
2838
2839 /*
2840 * Force the current process to exit with the specified signal, dumping core
2841 * if appropriate. We bypass the normal tests for masked and caught signals,
2842 * allowing unrecoverable failures to terminate the process without changing
2843 * signal state. Mark the accounting record with the signal termination.
2844 * If dumping core, save the signal number for the debugger. Calls exit and
2845 * does not return.
2846 */
2847 void
2848 sigexit(td, sig)
2849 struct thread *td;
2850 int sig;
2851 {
2852 struct proc *p = td->td_proc;
2853
2854 PROC_LOCK_ASSERT(p, MA_OWNED);
2855 p->p_acflag |= AXSIG;
2856 /*
2857 * We must be single-threading to generate a core dump. This
2858 * ensures that the registers in the core file are up-to-date.
2859 * Also, the ELF dump handler assumes that the thread list doesn't
2860 * change out from under it.
2861 *
2862 * XXX If another thread attempts to single-thread before us
2863 * (e.g. via fork()), we won't get a dump at all.
2864 */
2865 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) {
2866 p->p_sig = sig;
2867 /*
2868 * Log signals which would cause core dumps
2869 * (Log as LOG_INFO to appease those who don't want
2870 * these messages.)
2871 * XXX : Todo, as well as euid, write out ruid too
2872 * Note that coredump() drops proc lock.
2873 */
2874 if (coredump(td) == 0)
2875 sig |= WCOREFLAG;
2876 if (kern_logsigexit)
2877 log(LOG_INFO,
2878 "pid %d (%s), uid %d: exited on signal %d%s\n",
2879 p->p_pid, p->p_comm,
2880 td->td_ucred ? td->td_ucred->cr_uid : -1,
2881 sig &~ WCOREFLAG,
2882 sig & WCOREFLAG ? " (core dumped)" : "");
2883 } else
2884 PROC_UNLOCK(p);
2885 exit1(td, W_EXITCODE(0, sig));
2886 /* NOTREACHED */
2887 }
2888
2889 /*
2890 * Send queued SIGCHLD to parent when child process's state
2891 * is changed.
2892 */
2893 static void
2894 sigparent(struct proc *p, int reason, int status)
2895 {
2896 PROC_LOCK_ASSERT(p, MA_OWNED);
2897 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
2898
2899 if (p->p_ksi != NULL) {
2900 p->p_ksi->ksi_signo = SIGCHLD;
2901 p->p_ksi->ksi_code = reason;
2902 p->p_ksi->ksi_status = status;
2903 p->p_ksi->ksi_pid = p->p_pid;
2904 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid;
2905 if (KSI_ONQ(p->p_ksi))
2906 return;
2907 }
2908 tdsignal(p->p_pptr, NULL, SIGCHLD, p->p_ksi);
2909 }
2910
2911 static void
2912 childproc_jobstate(struct proc *p, int reason, int status)
2913 {
2914 struct sigacts *ps;
2915
2916 PROC_LOCK_ASSERT(p, MA_OWNED);
2917 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
2918
2919 /*
2920 * Wake up parent sleeping in kern_wait(), also send
2921 * SIGCHLD to parent, but SIGCHLD does not guarantee
2922 * that parent will awake, because parent may masked
2923 * the signal.
2924 */
2925 p->p_pptr->p_flag |= P_STATCHILD;
2926 wakeup(p->p_pptr);
2927
2928 ps = p->p_pptr->p_sigacts;
2929 mtx_lock(&ps->ps_mtx);
2930 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) {
2931 mtx_unlock(&ps->ps_mtx);
2932 sigparent(p, reason, status);
2933 } else
2934 mtx_unlock(&ps->ps_mtx);
2935 }
2936
2937 void
2938 childproc_stopped(struct proc *p, int reason)
2939 {
2940 childproc_jobstate(p, reason, p->p_xstat);
2941 }
2942
2943 void
2944 childproc_continued(struct proc *p)
2945 {
2946 childproc_jobstate(p, CLD_CONTINUED, SIGCONT);
2947 }
2948
2949 void
2950 childproc_exited(struct proc *p)
2951 {
2952 int reason;
2953 int status = p->p_xstat; /* convert to int */
2954
2955 reason = CLD_EXITED;
2956 if (WCOREDUMP(status))
2957 reason = CLD_DUMPED;
2958 else if (WIFSIGNALED(status))
2959 reason = CLD_KILLED;
2960 /*
2961 * XXX avoid calling wakeup(p->p_pptr), the work is
2962 * done in exit1().
2963 */
2964 sigparent(p, reason, status);
2965 }
2966
2967 static char corefilename[MAXPATHLEN] = {"%N.core"};
2968 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
2969 sizeof(corefilename), "process corefile name format string");
2970
2971 /*
2972 * expand_name(name, uid, pid)
2973 * Expand the name described in corefilename, using name, uid, and pid.
2974 * corefilename is a printf-like string, with three format specifiers:
2975 * %N name of process ("name")
2976 * %P process id (pid)
2977 * %U user id (uid)
2978 * For example, "%N.core" is the default; they can be disabled completely
2979 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
2980 * This is controlled by the sysctl variable kern.corefile (see above).
2981 */
2982 static char *
2983 expand_name(name, uid, pid)
2984 const char *name;
2985 uid_t uid;
2986 pid_t pid;
2987 {
2988 struct sbuf sb;
2989 const char *format;
2990 char *temp;
2991 size_t i;
2992
2993 format = corefilename;
2994 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO);
2995 if (temp == NULL)
2996 return (NULL);
2997 (void)sbuf_new(&sb, temp, MAXPATHLEN, SBUF_FIXEDLEN);
2998 for (i = 0; format[i]; i++) {
2999 switch (format[i]) {
3000 case '%': /* Format character */
3001 i++;
3002 switch (format[i]) {
3003 case '%':
3004 sbuf_putc(&sb, '%');
3005 break;
3006 case 'N': /* process name */
3007 sbuf_printf(&sb, "%s", name);
3008 break;
3009 case 'P': /* process id */
3010 sbuf_printf(&sb, "%u", pid);
3011 break;
3012 case 'U': /* user id */
3013 sbuf_printf(&sb, "%u", uid);
3014 break;
3015 default:
3016 log(LOG_ERR,
3017 "Unknown format character %c in "
3018 "corename `%s'\n", format[i], format);
3019 }
3020 break;
3021 default:
3022 sbuf_putc(&sb, format[i]);
3023 }
3024 }
3025 if (sbuf_overflowed(&sb)) {
3026 sbuf_delete(&sb);
3027 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too "
3028 "long\n", (long)pid, name, (u_long)uid);
3029 free(temp, M_TEMP);
3030 return (NULL);
3031 }
3032 sbuf_finish(&sb);
3033 sbuf_delete(&sb);
3034 return (temp);
3035 }
3036
3037 /*
3038 * Dump a process' core. The main routine does some
3039 * policy checking, and creates the name of the coredump;
3040 * then it passes on a vnode and a size limit to the process-specific
3041 * coredump routine if there is one; if there _is not_ one, it returns
3042 * ENOSYS; otherwise it returns the error from the process-specific routine.
3043 */
3044
3045 static int
3046 coredump(struct thread *td)
3047 {
3048 struct proc *p = td->td_proc;
3049 register struct vnode *vp;
3050 register struct ucred *cred = td->td_ucred;
3051 struct flock lf;
3052 struct nameidata nd;
3053 struct vattr vattr;
3054 int error, error1, flags, locked;
3055 struct mount *mp;
3056 char *name; /* name of corefile */
3057 off_t limit;
3058 int vfslocked;
3059
3060 PROC_LOCK_ASSERT(p, MA_OWNED);
3061 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td);
3062 _STOPEVENT(p, S_CORE, 0);
3063
3064 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid);
3065 if (name == NULL) {
3066 PROC_UNLOCK(p);
3067 #ifdef AUDIT
3068 audit_proc_coredump(td, NULL, EINVAL);
3069 #endif
3070 return (EINVAL);
3071 }
3072 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) {
3073 PROC_UNLOCK(p);
3074 #ifdef AUDIT
3075 audit_proc_coredump(td, name, EFAULT);
3076 #endif
3077 free(name, M_TEMP);
3078 return (EFAULT);
3079 }
3080
3081 /*
3082 * Note that the bulk of limit checking is done after
3083 * the corefile is created. The exception is if the limit
3084 * for corefiles is 0, in which case we don't bother
3085 * creating the corefile at all. This layout means that
3086 * a corefile is truncated instead of not being created,
3087 * if it is larger than the limit.
3088 */
3089 limit = (off_t)lim_cur(p, RLIMIT_CORE);
3090 PROC_UNLOCK(p);
3091 if (limit == 0) {
3092 #ifdef AUDIT
3093 audit_proc_coredump(td, name, EFBIG);
3094 #endif
3095 free(name, M_TEMP);
3096 return (EFBIG);
3097 }
3098
3099 restart:
3100 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, name, td);
3101 flags = O_CREAT | FWRITE | O_NOFOLLOW;
3102 error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR, NULL);
3103 if (error) {
3104 #ifdef AUDIT
3105 audit_proc_coredump(td, name, error);
3106 #endif
3107 free(name, M_TEMP);
3108 return (error);
3109 }
3110 vfslocked = NDHASGIANT(&nd);
3111 NDFREE(&nd, NDF_ONLY_PNBUF);
3112 vp = nd.ni_vp;
3113
3114 /* Don't dump to non-regular files or files with links. */
3115 if (vp->v_type != VREG ||
3116 VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) {
3117 VOP_UNLOCK(vp, 0, td);
3118 error = EFAULT;
3119 goto close;
3120 }
3121
3122 VOP_UNLOCK(vp, 0, td);
3123 lf.l_whence = SEEK_SET;
3124 lf.l_start = 0;
3125 lf.l_len = 0;
3126 lf.l_type = F_WRLCK;
3127 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0);
3128
3129 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
3130 lf.l_type = F_UNLCK;
3131 if (locked)
3132 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
3133 if ((error = vn_close(vp, FWRITE, cred, td)) != 0)
3134 goto out;
3135 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
3136 goto out;
3137 VFS_UNLOCK_GIANT(vfslocked);
3138 goto restart;
3139 }
3140
3141 VATTR_NULL(&vattr);
3142 vattr.va_size = 0;
3143 if (set_core_nodump_flag)
3144 vattr.va_flags = UF_NODUMP;
3145 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
3146 VOP_LEASE(vp, td, cred, LEASE_WRITE);
3147 VOP_SETATTR(vp, &vattr, cred, td);
3148 VOP_UNLOCK(vp, 0, td);
3149 vn_finished_write(mp);
3150 PROC_LOCK(p);
3151 p->p_acflag |= ACORE;
3152 PROC_UNLOCK(p);
3153
3154 error = p->p_sysent->sv_coredump ?
3155 p->p_sysent->sv_coredump(td, vp, limit) :
3156 ENOSYS;
3157
3158 if (locked) {
3159 lf.l_type = F_UNLCK;
3160 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
3161 }
3162 close:
3163 error1 = vn_close(vp, FWRITE, cred, td);
3164 if (error == 0)
3165 error = error1;
3166 out:
3167 #ifdef AUDIT
3168 audit_proc_coredump(td, name, error);
3169 #endif
3170 free(name, M_TEMP);
3171 VFS_UNLOCK_GIANT(vfslocked);
3172 return (error);
3173 }
3174
3175 /*
3176 * Nonexistent system call-- signal process (may want to handle it). Flag
3177 * error in case process won't see signal immediately (blocked or ignored).
3178 */
3179 #ifndef _SYS_SYSPROTO_H_
3180 struct nosys_args {
3181 int dummy;
3182 };
3183 #endif
3184 /* ARGSUSED */
3185 int
3186 nosys(td, args)
3187 struct thread *td;
3188 struct nosys_args *args;
3189 {
3190 struct proc *p = td->td_proc;
3191
3192 PROC_LOCK(p);
3193 psignal(p, SIGSYS);
3194 PROC_UNLOCK(p);
3195 return (ENOSYS);
3196 }
3197
3198 /*
3199 * Send a SIGIO or SIGURG signal to a process or process group using stored
3200 * credentials rather than those of the current process.
3201 */
3202 void
3203 pgsigio(sigiop, sig, checkctty)
3204 struct sigio **sigiop;
3205 int sig, checkctty;
3206 {
3207 struct sigio *sigio;
3208
3209 SIGIO_LOCK();
3210 sigio = *sigiop;
3211 if (sigio == NULL) {
3212 SIGIO_UNLOCK();
3213 return;
3214 }
3215 if (sigio->sio_pgid > 0) {
3216 PROC_LOCK(sigio->sio_proc);
3217 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred))
3218 psignal(sigio->sio_proc, sig);
3219 PROC_UNLOCK(sigio->sio_proc);
3220 } else if (sigio->sio_pgid < 0) {
3221 struct proc *p;
3222
3223 PGRP_LOCK(sigio->sio_pgrp);
3224 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
3225 PROC_LOCK(p);
3226 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) &&
3227 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
3228 psignal(p, sig);
3229 PROC_UNLOCK(p);
3230 }
3231 PGRP_UNLOCK(sigio->sio_pgrp);
3232 }
3233 SIGIO_UNLOCK();
3234 }
3235
3236 static int
3237 filt_sigattach(struct knote *kn)
3238 {
3239 struct proc *p = curproc;
3240
3241 kn->kn_ptr.p_proc = p;
3242 kn->kn_flags |= EV_CLEAR; /* automatically set */
3243
3244 knlist_add(&p->p_klist, kn, 0);
3245
3246 return (0);
3247 }
3248
3249 static void
3250 filt_sigdetach(struct knote *kn)
3251 {
3252 struct proc *p = kn->kn_ptr.p_proc;
3253
3254 knlist_remove(&p->p_klist, kn, 0);
3255 }
3256
3257 /*
3258 * signal knotes are shared with proc knotes, so we apply a mask to
3259 * the hint in order to differentiate them from process hints. This
3260 * could be avoided by using a signal-specific knote list, but probably
3261 * isn't worth the trouble.
3262 */
3263 static int
3264 filt_signal(struct knote *kn, long hint)
3265 {
3266
3267 if (hint & NOTE_SIGNAL) {
3268 hint &= ~NOTE_SIGNAL;
3269
3270 if (kn->kn_id == hint)
3271 kn->kn_data++;
3272 }
3273 return (kn->kn_data != 0);
3274 }
3275
3276 struct sigacts *
3277 sigacts_alloc(void)
3278 {
3279 struct sigacts *ps;
3280
3281 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO);
3282 ps->ps_refcnt = 1;
3283 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF);
3284 return (ps);
3285 }
3286
3287 void
3288 sigacts_free(struct sigacts *ps)
3289 {
3290
3291 mtx_lock(&ps->ps_mtx);
3292 ps->ps_refcnt--;
3293 if (ps->ps_refcnt == 0) {
3294 mtx_destroy(&ps->ps_mtx);
3295 free(ps, M_SUBPROC);
3296 } else
3297 mtx_unlock(&ps->ps_mtx);
3298 }
3299
3300 struct sigacts *
3301 sigacts_hold(struct sigacts *ps)
3302 {
3303 mtx_lock(&ps->ps_mtx);
3304 ps->ps_refcnt++;
3305 mtx_unlock(&ps->ps_mtx);
3306 return (ps);
3307 }
3308
3309 void
3310 sigacts_copy(struct sigacts *dest, struct sigacts *src)
3311 {
3312
3313 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest"));
3314 mtx_lock(&src->ps_mtx);
3315 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt));
3316 mtx_unlock(&src->ps_mtx);
3317 }
3318
3319 int
3320 sigacts_shared(struct sigacts *ps)
3321 {
3322 int shared;
3323
3324 mtx_lock(&ps->ps_mtx);
3325 shared = ps->ps_refcnt > 1;
3326 mtx_unlock(&ps->ps_mtx);
3327 return (shared);
3328 }
Cache object: 08229e7dcb14a80019f3cc7ac1bea9b1
|