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/10.1/sys/kern/kern_sig.c 270788 2014-08-29 08:38:34Z kib $");
39
40 #include "opt_compat.h"
41 #include "opt_kdtrace.h"
42 #include "opt_ktrace.h"
43 #include "opt_core.h"
44 #include "opt_procdesc.h"
45
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/signalvar.h>
49 #include <sys/vnode.h>
50 #include <sys/acct.h>
51 #include <sys/capability.h>
52 #include <sys/condvar.h>
53 #include <sys/event.h>
54 #include <sys/fcntl.h>
55 #include <sys/imgact.h>
56 #include <sys/kernel.h>
57 #include <sys/ktr.h>
58 #include <sys/ktrace.h>
59 #include <sys/lock.h>
60 #include <sys/malloc.h>
61 #include <sys/mutex.h>
62 #include <sys/refcount.h>
63 #include <sys/namei.h>
64 #include <sys/proc.h>
65 #include <sys/procdesc.h>
66 #include <sys/posix4.h>
67 #include <sys/pioctl.h>
68 #include <sys/racct.h>
69 #include <sys/resourcevar.h>
70 #include <sys/sdt.h>
71 #include <sys/sbuf.h>
72 #include <sys/sleepqueue.h>
73 #include <sys/smp.h>
74 #include <sys/stat.h>
75 #include <sys/sx.h>
76 #include <sys/syscallsubr.h>
77 #include <sys/sysctl.h>
78 #include <sys/sysent.h>
79 #include <sys/syslog.h>
80 #include <sys/sysproto.h>
81 #include <sys/timers.h>
82 #include <sys/unistd.h>
83 #include <sys/wait.h>
84 #include <vm/vm.h>
85 #include <vm/vm_extern.h>
86 #include <vm/uma.h>
87
88 #include <sys/jail.h>
89
90 #include <machine/cpu.h>
91
92 #include <security/audit/audit.h>
93
94 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */
95
96 SDT_PROVIDER_DECLARE(proc);
97 SDT_PROBE_DEFINE3(proc, kernel, , signal__send, "struct thread *",
98 "struct proc *", "int");
99 SDT_PROBE_DEFINE2(proc, kernel, , signal__clear, "int",
100 "ksiginfo_t *");
101 SDT_PROBE_DEFINE3(proc, kernel, , signal__discard,
102 "struct thread *", "struct proc *", "int");
103
104 static int coredump(struct thread *);
105 static int killpg1(struct thread *td, int sig, int pgid, int all,
106 ksiginfo_t *ksi);
107 static int issignal(struct thread *td);
108 static int sigprop(int sig);
109 static void tdsigwakeup(struct thread *, int, sig_t, int);
110 static void sig_suspend_threads(struct thread *, struct proc *, int);
111 static int filt_sigattach(struct knote *kn);
112 static void filt_sigdetach(struct knote *kn);
113 static int filt_signal(struct knote *kn, long hint);
114 static struct thread *sigtd(struct proc *p, int sig, int prop);
115 static void sigqueue_start(void);
116
117 static uma_zone_t ksiginfo_zone = NULL;
118 struct filterops sig_filtops = {
119 .f_isfd = 0,
120 .f_attach = filt_sigattach,
121 .f_detach = filt_sigdetach,
122 .f_event = filt_signal,
123 };
124
125 static int kern_logsigexit = 1;
126 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
127 &kern_logsigexit, 0,
128 "Log processes quitting on abnormal signals to syslog(3)");
129
130 static int kern_forcesigexit = 1;
131 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW,
132 &kern_forcesigexit, 0, "Force trap signal to be handled");
133
134 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0,
135 "POSIX real time signal");
136
137 static int max_pending_per_proc = 128;
138 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW,
139 &max_pending_per_proc, 0, "Max pending signals per proc");
140
141 static int preallocate_siginfo = 1024;
142 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo);
143 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD,
144 &preallocate_siginfo, 0, "Preallocated signal memory size");
145
146 static int signal_overflow = 0;
147 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD,
148 &signal_overflow, 0, "Number of signals overflew");
149
150 static int signal_alloc_fail = 0;
151 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD,
152 &signal_alloc_fail, 0, "signals failed to be allocated");
153
154 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL);
155
156 /*
157 * Policy -- Can ucred cr1 send SIGIO to process cr2?
158 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG
159 * in the right situations.
160 */
161 #define CANSIGIO(cr1, cr2) \
162 ((cr1)->cr_uid == 0 || \
163 (cr1)->cr_ruid == (cr2)->cr_ruid || \
164 (cr1)->cr_uid == (cr2)->cr_ruid || \
165 (cr1)->cr_ruid == (cr2)->cr_uid || \
166 (cr1)->cr_uid == (cr2)->cr_uid)
167
168 static int sugid_coredump;
169 TUNABLE_INT("kern.sugid_coredump", &sugid_coredump);
170 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
171 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core");
172
173 static int capmode_coredump;
174 TUNABLE_INT("kern.capmode_coredump", &capmode_coredump);
175 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RW,
176 &capmode_coredump, 0, "Allow processes in capability mode to dump core");
177
178 static int do_coredump = 1;
179 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
180 &do_coredump, 0, "Enable/Disable coredumps");
181
182 static int set_core_nodump_flag = 0;
183 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag,
184 0, "Enable setting the NODUMP flag on coredump files");
185
186 /*
187 * Signal properties and actions.
188 * The array below categorizes the signals and their default actions
189 * according to the following properties:
190 */
191 #define SA_KILL 0x01 /* terminates process by default */
192 #define SA_CORE 0x02 /* ditto and coredumps */
193 #define SA_STOP 0x04 /* suspend process */
194 #define SA_TTYSTOP 0x08 /* ditto, from tty */
195 #define SA_IGNORE 0x10 /* ignore by default */
196 #define SA_CONT 0x20 /* continue if suspended */
197 #define SA_CANTMASK 0x40 /* non-maskable, catchable */
198
199 static int sigproptbl[NSIG] = {
200 SA_KILL, /* SIGHUP */
201 SA_KILL, /* SIGINT */
202 SA_KILL|SA_CORE, /* SIGQUIT */
203 SA_KILL|SA_CORE, /* SIGILL */
204 SA_KILL|SA_CORE, /* SIGTRAP */
205 SA_KILL|SA_CORE, /* SIGABRT */
206 SA_KILL|SA_CORE, /* SIGEMT */
207 SA_KILL|SA_CORE, /* SIGFPE */
208 SA_KILL, /* SIGKILL */
209 SA_KILL|SA_CORE, /* SIGBUS */
210 SA_KILL|SA_CORE, /* SIGSEGV */
211 SA_KILL|SA_CORE, /* SIGSYS */
212 SA_KILL, /* SIGPIPE */
213 SA_KILL, /* SIGALRM */
214 SA_KILL, /* SIGTERM */
215 SA_IGNORE, /* SIGURG */
216 SA_STOP, /* SIGSTOP */
217 SA_STOP|SA_TTYSTOP, /* SIGTSTP */
218 SA_IGNORE|SA_CONT, /* SIGCONT */
219 SA_IGNORE, /* SIGCHLD */
220 SA_STOP|SA_TTYSTOP, /* SIGTTIN */
221 SA_STOP|SA_TTYSTOP, /* SIGTTOU */
222 SA_IGNORE, /* SIGIO */
223 SA_KILL, /* SIGXCPU */
224 SA_KILL, /* SIGXFSZ */
225 SA_KILL, /* SIGVTALRM */
226 SA_KILL, /* SIGPROF */
227 SA_IGNORE, /* SIGWINCH */
228 SA_IGNORE, /* SIGINFO */
229 SA_KILL, /* SIGUSR1 */
230 SA_KILL, /* SIGUSR2 */
231 };
232
233 static void reschedule_signals(struct proc *p, sigset_t block, int flags);
234
235 static void
236 sigqueue_start(void)
237 {
238 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t),
239 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
240 uma_prealloc(ksiginfo_zone, preallocate_siginfo);
241 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS);
242 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1);
243 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc);
244 }
245
246 ksiginfo_t *
247 ksiginfo_alloc(int wait)
248 {
249 int flags;
250
251 flags = M_ZERO;
252 if (! wait)
253 flags |= M_NOWAIT;
254 if (ksiginfo_zone != NULL)
255 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags));
256 return (NULL);
257 }
258
259 void
260 ksiginfo_free(ksiginfo_t *ksi)
261 {
262 uma_zfree(ksiginfo_zone, ksi);
263 }
264
265 static __inline int
266 ksiginfo_tryfree(ksiginfo_t *ksi)
267 {
268 if (!(ksi->ksi_flags & KSI_EXT)) {
269 uma_zfree(ksiginfo_zone, ksi);
270 return (1);
271 }
272 return (0);
273 }
274
275 void
276 sigqueue_init(sigqueue_t *list, struct proc *p)
277 {
278 SIGEMPTYSET(list->sq_signals);
279 SIGEMPTYSET(list->sq_kill);
280 TAILQ_INIT(&list->sq_list);
281 list->sq_proc = p;
282 list->sq_flags = SQ_INIT;
283 }
284
285 /*
286 * Get a signal's ksiginfo.
287 * Return:
288 * 0 - signal not found
289 * others - signal number
290 */
291 static int
292 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si)
293 {
294 struct proc *p = sq->sq_proc;
295 struct ksiginfo *ksi, *next;
296 int count = 0;
297
298 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
299
300 if (!SIGISMEMBER(sq->sq_signals, signo))
301 return (0);
302
303 if (SIGISMEMBER(sq->sq_kill, signo)) {
304 count++;
305 SIGDELSET(sq->sq_kill, signo);
306 }
307
308 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
309 if (ksi->ksi_signo == signo) {
310 if (count == 0) {
311 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
312 ksi->ksi_sigq = NULL;
313 ksiginfo_copy(ksi, si);
314 if (ksiginfo_tryfree(ksi) && p != NULL)
315 p->p_pendingcnt--;
316 }
317 if (++count > 1)
318 break;
319 }
320 }
321
322 if (count <= 1)
323 SIGDELSET(sq->sq_signals, signo);
324 si->ksi_signo = signo;
325 return (signo);
326 }
327
328 void
329 sigqueue_take(ksiginfo_t *ksi)
330 {
331 struct ksiginfo *kp;
332 struct proc *p;
333 sigqueue_t *sq;
334
335 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL)
336 return;
337
338 p = sq->sq_proc;
339 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
340 ksi->ksi_sigq = NULL;
341 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL)
342 p->p_pendingcnt--;
343
344 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL;
345 kp = TAILQ_NEXT(kp, ksi_link)) {
346 if (kp->ksi_signo == ksi->ksi_signo)
347 break;
348 }
349 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo))
350 SIGDELSET(sq->sq_signals, ksi->ksi_signo);
351 }
352
353 static int
354 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si)
355 {
356 struct proc *p = sq->sq_proc;
357 struct ksiginfo *ksi;
358 int ret = 0;
359
360 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
361
362 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) {
363 SIGADDSET(sq->sq_kill, signo);
364 goto out_set_bit;
365 }
366
367 /* directly insert the ksi, don't copy it */
368 if (si->ksi_flags & KSI_INS) {
369 if (si->ksi_flags & KSI_HEAD)
370 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link);
371 else
372 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link);
373 si->ksi_sigq = sq;
374 goto out_set_bit;
375 }
376
377 if (__predict_false(ksiginfo_zone == NULL)) {
378 SIGADDSET(sq->sq_kill, signo);
379 goto out_set_bit;
380 }
381
382 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) {
383 signal_overflow++;
384 ret = EAGAIN;
385 } else if ((ksi = ksiginfo_alloc(0)) == NULL) {
386 signal_alloc_fail++;
387 ret = EAGAIN;
388 } else {
389 if (p != NULL)
390 p->p_pendingcnt++;
391 ksiginfo_copy(si, ksi);
392 ksi->ksi_signo = signo;
393 if (si->ksi_flags & KSI_HEAD)
394 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link);
395 else
396 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link);
397 ksi->ksi_sigq = sq;
398 }
399
400 if ((si->ksi_flags & KSI_TRAP) != 0 ||
401 (si->ksi_flags & KSI_SIGQ) == 0) {
402 if (ret != 0)
403 SIGADDSET(sq->sq_kill, signo);
404 ret = 0;
405 goto out_set_bit;
406 }
407
408 if (ret != 0)
409 return (ret);
410
411 out_set_bit:
412 SIGADDSET(sq->sq_signals, signo);
413 return (ret);
414 }
415
416 void
417 sigqueue_flush(sigqueue_t *sq)
418 {
419 struct proc *p = sq->sq_proc;
420 ksiginfo_t *ksi;
421
422 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
423
424 if (p != NULL)
425 PROC_LOCK_ASSERT(p, MA_OWNED);
426
427 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) {
428 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
429 ksi->ksi_sigq = NULL;
430 if (ksiginfo_tryfree(ksi) && p != NULL)
431 p->p_pendingcnt--;
432 }
433
434 SIGEMPTYSET(sq->sq_signals);
435 SIGEMPTYSET(sq->sq_kill);
436 }
437
438 static void
439 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set)
440 {
441 sigset_t tmp;
442 struct proc *p1, *p2;
443 ksiginfo_t *ksi, *next;
444
445 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited"));
446 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited"));
447 p1 = src->sq_proc;
448 p2 = dst->sq_proc;
449 /* Move siginfo to target list */
450 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) {
451 if (SIGISMEMBER(*set, ksi->ksi_signo)) {
452 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link);
453 if (p1 != NULL)
454 p1->p_pendingcnt--;
455 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link);
456 ksi->ksi_sigq = dst;
457 if (p2 != NULL)
458 p2->p_pendingcnt++;
459 }
460 }
461
462 /* Move pending bits to target list */
463 tmp = src->sq_kill;
464 SIGSETAND(tmp, *set);
465 SIGSETOR(dst->sq_kill, tmp);
466 SIGSETNAND(src->sq_kill, tmp);
467
468 tmp = src->sq_signals;
469 SIGSETAND(tmp, *set);
470 SIGSETOR(dst->sq_signals, tmp);
471 SIGSETNAND(src->sq_signals, tmp);
472 }
473
474 #if 0
475 static void
476 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo)
477 {
478 sigset_t set;
479
480 SIGEMPTYSET(set);
481 SIGADDSET(set, signo);
482 sigqueue_move_set(src, dst, &set);
483 }
484 #endif
485
486 static void
487 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set)
488 {
489 struct proc *p = sq->sq_proc;
490 ksiginfo_t *ksi, *next;
491
492 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited"));
493
494 /* Remove siginfo queue */
495 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
496 if (SIGISMEMBER(*set, ksi->ksi_signo)) {
497 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
498 ksi->ksi_sigq = NULL;
499 if (ksiginfo_tryfree(ksi) && p != NULL)
500 p->p_pendingcnt--;
501 }
502 }
503 SIGSETNAND(sq->sq_kill, *set);
504 SIGSETNAND(sq->sq_signals, *set);
505 }
506
507 void
508 sigqueue_delete(sigqueue_t *sq, int signo)
509 {
510 sigset_t set;
511
512 SIGEMPTYSET(set);
513 SIGADDSET(set, signo);
514 sigqueue_delete_set(sq, &set);
515 }
516
517 /* Remove a set of signals for a process */
518 static void
519 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set)
520 {
521 sigqueue_t worklist;
522 struct thread *td0;
523
524 PROC_LOCK_ASSERT(p, MA_OWNED);
525
526 sigqueue_init(&worklist, NULL);
527 sigqueue_move_set(&p->p_sigqueue, &worklist, set);
528
529 FOREACH_THREAD_IN_PROC(p, td0)
530 sigqueue_move_set(&td0->td_sigqueue, &worklist, set);
531
532 sigqueue_flush(&worklist);
533 }
534
535 void
536 sigqueue_delete_proc(struct proc *p, int signo)
537 {
538 sigset_t set;
539
540 SIGEMPTYSET(set);
541 SIGADDSET(set, signo);
542 sigqueue_delete_set_proc(p, &set);
543 }
544
545 static void
546 sigqueue_delete_stopmask_proc(struct proc *p)
547 {
548 sigset_t set;
549
550 SIGEMPTYSET(set);
551 SIGADDSET(set, SIGSTOP);
552 SIGADDSET(set, SIGTSTP);
553 SIGADDSET(set, SIGTTIN);
554 SIGADDSET(set, SIGTTOU);
555 sigqueue_delete_set_proc(p, &set);
556 }
557
558 /*
559 * Determine signal that should be delivered to thread td, the current
560 * thread, 0 if none. If there is a pending stop signal with default
561 * action, the process stops in issignal().
562 */
563 int
564 cursig(struct thread *td)
565 {
566 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
567 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED);
568 THREAD_LOCK_ASSERT(td, MA_NOTOWNED);
569 return (SIGPENDING(td) ? issignal(td) : 0);
570 }
571
572 /*
573 * Arrange for ast() to handle unmasked pending signals on return to user
574 * mode. This must be called whenever a signal is added to td_sigqueue or
575 * unmasked in td_sigmask.
576 */
577 void
578 signotify(struct thread *td)
579 {
580 struct proc *p;
581
582 p = td->td_proc;
583
584 PROC_LOCK_ASSERT(p, MA_OWNED);
585
586 if (SIGPENDING(td)) {
587 thread_lock(td);
588 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING;
589 thread_unlock(td);
590 }
591 }
592
593 int
594 sigonstack(size_t sp)
595 {
596 struct thread *td = curthread;
597
598 return ((td->td_pflags & TDP_ALTSTACK) ?
599 #if defined(COMPAT_43)
600 ((td->td_sigstk.ss_size == 0) ?
601 (td->td_sigstk.ss_flags & SS_ONSTACK) :
602 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size))
603 #else
604 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)
605 #endif
606 : 0);
607 }
608
609 static __inline int
610 sigprop(int sig)
611 {
612
613 if (sig > 0 && sig < NSIG)
614 return (sigproptbl[_SIG_IDX(sig)]);
615 return (0);
616 }
617
618 int
619 sig_ffs(sigset_t *set)
620 {
621 int i;
622
623 for (i = 0; i < _SIG_WORDS; i++)
624 if (set->__bits[i])
625 return (ffs(set->__bits[i]) + (i * 32));
626 return (0);
627 }
628
629 static bool
630 sigact_flag_test(struct sigaction *act, int flag)
631 {
632
633 /*
634 * SA_SIGINFO is reset when signal disposition is set to
635 * ignore or default. Other flags are kept according to user
636 * settings.
637 */
638 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO ||
639 ((__sighandler_t *)act->sa_sigaction != SIG_IGN &&
640 (__sighandler_t *)act->sa_sigaction != SIG_DFL)));
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 if (act != NULL && (act->sa_flags & ~(SA_ONSTACK | SA_RESTART |
662 SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | SA_NOCLDWAIT |
663 SA_SIGINFO)) != 0)
664 return (EINVAL);
665
666 PROC_LOCK(p);
667 ps = p->p_sigacts;
668 mtx_lock(&ps->ps_mtx);
669 if (oact) {
670 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
671 oact->sa_flags = 0;
672 if (SIGISMEMBER(ps->ps_sigonstack, sig))
673 oact->sa_flags |= SA_ONSTACK;
674 if (!SIGISMEMBER(ps->ps_sigintr, sig))
675 oact->sa_flags |= SA_RESTART;
676 if (SIGISMEMBER(ps->ps_sigreset, sig))
677 oact->sa_flags |= SA_RESETHAND;
678 if (SIGISMEMBER(ps->ps_signodefer, sig))
679 oact->sa_flags |= SA_NODEFER;
680 if (SIGISMEMBER(ps->ps_siginfo, sig)) {
681 oact->sa_flags |= SA_SIGINFO;
682 oact->sa_sigaction =
683 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)];
684 } else
685 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
686 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP)
687 oact->sa_flags |= SA_NOCLDSTOP;
688 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT)
689 oact->sa_flags |= SA_NOCLDWAIT;
690 }
691 if (act) {
692 if ((sig == SIGKILL || sig == SIGSTOP) &&
693 act->sa_handler != SIG_DFL) {
694 mtx_unlock(&ps->ps_mtx);
695 PROC_UNLOCK(p);
696 return (EINVAL);
697 }
698
699 /*
700 * Change setting atomically.
701 */
702
703 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
704 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
705 if (sigact_flag_test(act, SA_SIGINFO)) {
706 ps->ps_sigact[_SIG_IDX(sig)] =
707 (__sighandler_t *)act->sa_sigaction;
708 SIGADDSET(ps->ps_siginfo, sig);
709 } else {
710 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
711 SIGDELSET(ps->ps_siginfo, sig);
712 }
713 if (!sigact_flag_test(act, SA_RESTART))
714 SIGADDSET(ps->ps_sigintr, sig);
715 else
716 SIGDELSET(ps->ps_sigintr, sig);
717 if (sigact_flag_test(act, SA_ONSTACK))
718 SIGADDSET(ps->ps_sigonstack, sig);
719 else
720 SIGDELSET(ps->ps_sigonstack, sig);
721 if (sigact_flag_test(act, SA_RESETHAND))
722 SIGADDSET(ps->ps_sigreset, sig);
723 else
724 SIGDELSET(ps->ps_sigreset, sig);
725 if (sigact_flag_test(act, SA_NODEFER))
726 SIGADDSET(ps->ps_signodefer, sig);
727 else
728 SIGDELSET(ps->ps_signodefer, sig);
729 if (sig == SIGCHLD) {
730 if (act->sa_flags & SA_NOCLDSTOP)
731 ps->ps_flag |= PS_NOCLDSTOP;
732 else
733 ps->ps_flag &= ~PS_NOCLDSTOP;
734 if (act->sa_flags & SA_NOCLDWAIT) {
735 /*
736 * Paranoia: since SA_NOCLDWAIT is implemented
737 * by reparenting the dying child to PID 1 (and
738 * trust it to reap the zombie), PID 1 itself
739 * is forbidden to set SA_NOCLDWAIT.
740 */
741 if (p->p_pid == 1)
742 ps->ps_flag &= ~PS_NOCLDWAIT;
743 else
744 ps->ps_flag |= PS_NOCLDWAIT;
745 } else
746 ps->ps_flag &= ~PS_NOCLDWAIT;
747 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
748 ps->ps_flag |= PS_CLDSIGIGN;
749 else
750 ps->ps_flag &= ~PS_CLDSIGIGN;
751 }
752 /*
753 * Set bit in ps_sigignore for signals that are set to SIG_IGN,
754 * and for signals set to SIG_DFL where the default is to
755 * ignore. However, don't put SIGCONT in ps_sigignore, as we
756 * have to restart the process.
757 */
758 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
759 (sigprop(sig) & SA_IGNORE &&
760 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
761 /* never to be seen again */
762 sigqueue_delete_proc(p, sig);
763 if (sig != SIGCONT)
764 /* easier in psignal */
765 SIGADDSET(ps->ps_sigignore, sig);
766 SIGDELSET(ps->ps_sigcatch, sig);
767 } else {
768 SIGDELSET(ps->ps_sigignore, sig);
769 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
770 SIGDELSET(ps->ps_sigcatch, sig);
771 else
772 SIGADDSET(ps->ps_sigcatch, sig);
773 }
774 #ifdef COMPAT_FREEBSD4
775 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
776 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
777 (flags & KSA_FREEBSD4) == 0)
778 SIGDELSET(ps->ps_freebsd4, sig);
779 else
780 SIGADDSET(ps->ps_freebsd4, sig);
781 #endif
782 #ifdef COMPAT_43
783 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
784 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
785 (flags & KSA_OSIGSET) == 0)
786 SIGDELSET(ps->ps_osigset, sig);
787 else
788 SIGADDSET(ps->ps_osigset, sig);
789 #endif
790 }
791 mtx_unlock(&ps->ps_mtx);
792 PROC_UNLOCK(p);
793 return (0);
794 }
795
796 #ifndef _SYS_SYSPROTO_H_
797 struct sigaction_args {
798 int sig;
799 struct sigaction *act;
800 struct sigaction *oact;
801 };
802 #endif
803 int
804 sys_sigaction(td, uap)
805 struct thread *td;
806 register struct sigaction_args *uap;
807 {
808 struct sigaction act, oact;
809 register struct sigaction *actp, *oactp;
810 int error;
811
812 actp = (uap->act != NULL) ? &act : NULL;
813 oactp = (uap->oact != NULL) ? &oact : NULL;
814 if (actp) {
815 error = copyin(uap->act, actp, sizeof(act));
816 if (error)
817 return (error);
818 }
819 error = kern_sigaction(td, uap->sig, actp, oactp, 0);
820 if (oactp && !error)
821 error = copyout(oactp, uap->oact, sizeof(oact));
822 return (error);
823 }
824
825 #ifdef COMPAT_FREEBSD4
826 #ifndef _SYS_SYSPROTO_H_
827 struct freebsd4_sigaction_args {
828 int sig;
829 struct sigaction *act;
830 struct sigaction *oact;
831 };
832 #endif
833 int
834 freebsd4_sigaction(td, uap)
835 struct thread *td;
836 register struct freebsd4_sigaction_args *uap;
837 {
838 struct sigaction act, oact;
839 register struct sigaction *actp, *oactp;
840 int error;
841
842
843 actp = (uap->act != NULL) ? &act : NULL;
844 oactp = (uap->oact != NULL) ? &oact : NULL;
845 if (actp) {
846 error = copyin(uap->act, actp, sizeof(act));
847 if (error)
848 return (error);
849 }
850 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4);
851 if (oactp && !error)
852 error = copyout(oactp, uap->oact, sizeof(oact));
853 return (error);
854 }
855 #endif /* COMAPT_FREEBSD4 */
856
857 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
858 #ifndef _SYS_SYSPROTO_H_
859 struct osigaction_args {
860 int signum;
861 struct osigaction *nsa;
862 struct osigaction *osa;
863 };
864 #endif
865 int
866 osigaction(td, uap)
867 struct thread *td;
868 register struct osigaction_args *uap;
869 {
870 struct osigaction sa;
871 struct sigaction nsa, osa;
872 register struct sigaction *nsap, *osap;
873 int error;
874
875 if (uap->signum <= 0 || uap->signum >= ONSIG)
876 return (EINVAL);
877
878 nsap = (uap->nsa != NULL) ? &nsa : NULL;
879 osap = (uap->osa != NULL) ? &osa : NULL;
880
881 if (nsap) {
882 error = copyin(uap->nsa, &sa, sizeof(sa));
883 if (error)
884 return (error);
885 nsap->sa_handler = sa.sa_handler;
886 nsap->sa_flags = sa.sa_flags;
887 OSIG2SIG(sa.sa_mask, nsap->sa_mask);
888 }
889 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
890 if (osap && !error) {
891 sa.sa_handler = osap->sa_handler;
892 sa.sa_flags = osap->sa_flags;
893 SIG2OSIG(osap->sa_mask, sa.sa_mask);
894 error = copyout(&sa, uap->osa, sizeof(sa));
895 }
896 return (error);
897 }
898
899 #if !defined(__i386__)
900 /* Avoid replicating the same stub everywhere */
901 int
902 osigreturn(td, uap)
903 struct thread *td;
904 struct osigreturn_args *uap;
905 {
906
907 return (nosys(td, (struct nosys_args *)uap));
908 }
909 #endif
910 #endif /* COMPAT_43 */
911
912 /*
913 * Initialize signal state for process 0;
914 * set to ignore signals that are ignored by default.
915 */
916 void
917 siginit(p)
918 struct proc *p;
919 {
920 register int i;
921 struct sigacts *ps;
922
923 PROC_LOCK(p);
924 ps = p->p_sigacts;
925 mtx_lock(&ps->ps_mtx);
926 for (i = 1; i <= NSIG; i++) {
927 if (sigprop(i) & SA_IGNORE && i != SIGCONT) {
928 SIGADDSET(ps->ps_sigignore, i);
929 }
930 }
931 mtx_unlock(&ps->ps_mtx);
932 PROC_UNLOCK(p);
933 }
934
935 /*
936 * Reset specified signal to the default disposition.
937 */
938 static void
939 sigdflt(struct sigacts *ps, int sig)
940 {
941
942 mtx_assert(&ps->ps_mtx, MA_OWNED);
943 SIGDELSET(ps->ps_sigcatch, sig);
944 if ((sigprop(sig) & SA_IGNORE) != 0 && sig != SIGCONT)
945 SIGADDSET(ps->ps_sigignore, sig);
946 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
947 SIGDELSET(ps->ps_siginfo, sig);
948 }
949
950 /*
951 * Reset signals for an exec of the specified process.
952 */
953 void
954 execsigs(struct proc *p)
955 {
956 struct sigacts *ps;
957 int sig;
958 struct thread *td;
959
960 /*
961 * Reset caught signals. Held signals remain held
962 * through td_sigmask (unless they were caught,
963 * and are now ignored by default).
964 */
965 PROC_LOCK_ASSERT(p, MA_OWNED);
966 td = FIRST_THREAD_IN_PROC(p);
967 ps = p->p_sigacts;
968 mtx_lock(&ps->ps_mtx);
969 while (SIGNOTEMPTY(ps->ps_sigcatch)) {
970 sig = sig_ffs(&ps->ps_sigcatch);
971 sigdflt(ps, sig);
972 if ((sigprop(sig) & SA_IGNORE) != 0)
973 sigqueue_delete_proc(p, sig);
974 }
975 /*
976 * Reset stack state to the user stack.
977 * Clear set of signals caught on the signal stack.
978 */
979 td->td_sigstk.ss_flags = SS_DISABLE;
980 td->td_sigstk.ss_size = 0;
981 td->td_sigstk.ss_sp = 0;
982 td->td_pflags &= ~TDP_ALTSTACK;
983 /*
984 * Reset no zombies if child dies flag as Solaris does.
985 */
986 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN);
987 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
988 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL;
989 mtx_unlock(&ps->ps_mtx);
990 }
991
992 /*
993 * kern_sigprocmask()
994 *
995 * Manipulate signal mask.
996 */
997 int
998 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset,
999 int flags)
1000 {
1001 sigset_t new_block, oset1;
1002 struct proc *p;
1003 int error;
1004
1005 p = td->td_proc;
1006 if (!(flags & SIGPROCMASK_PROC_LOCKED))
1007 PROC_LOCK(p);
1008 if (oset != NULL)
1009 *oset = td->td_sigmask;
1010
1011 error = 0;
1012 if (set != NULL) {
1013 switch (how) {
1014 case SIG_BLOCK:
1015 SIG_CANTMASK(*set);
1016 oset1 = td->td_sigmask;
1017 SIGSETOR(td->td_sigmask, *set);
1018 new_block = td->td_sigmask;
1019 SIGSETNAND(new_block, oset1);
1020 break;
1021 case SIG_UNBLOCK:
1022 SIGSETNAND(td->td_sigmask, *set);
1023 signotify(td);
1024 goto out;
1025 case SIG_SETMASK:
1026 SIG_CANTMASK(*set);
1027 oset1 = td->td_sigmask;
1028 if (flags & SIGPROCMASK_OLD)
1029 SIGSETLO(td->td_sigmask, *set);
1030 else
1031 td->td_sigmask = *set;
1032 new_block = td->td_sigmask;
1033 SIGSETNAND(new_block, oset1);
1034 signotify(td);
1035 break;
1036 default:
1037 error = EINVAL;
1038 goto out;
1039 }
1040
1041 /*
1042 * The new_block set contains signals that were not previously
1043 * blocked, but are blocked now.
1044 *
1045 * In case we block any signal that was not previously blocked
1046 * for td, and process has the signal pending, try to schedule
1047 * signal delivery to some thread that does not block the
1048 * signal, possibly waking it up.
1049 */
1050 if (p->p_numthreads != 1)
1051 reschedule_signals(p, new_block, flags);
1052 }
1053
1054 out:
1055 if (!(flags & SIGPROCMASK_PROC_LOCKED))
1056 PROC_UNLOCK(p);
1057 return (error);
1058 }
1059
1060 #ifndef _SYS_SYSPROTO_H_
1061 struct sigprocmask_args {
1062 int how;
1063 const sigset_t *set;
1064 sigset_t *oset;
1065 };
1066 #endif
1067 int
1068 sys_sigprocmask(td, uap)
1069 register struct thread *td;
1070 struct sigprocmask_args *uap;
1071 {
1072 sigset_t set, oset;
1073 sigset_t *setp, *osetp;
1074 int error;
1075
1076 setp = (uap->set != NULL) ? &set : NULL;
1077 osetp = (uap->oset != NULL) ? &oset : NULL;
1078 if (setp) {
1079 error = copyin(uap->set, setp, sizeof(set));
1080 if (error)
1081 return (error);
1082 }
1083 error = kern_sigprocmask(td, uap->how, setp, osetp, 0);
1084 if (osetp && !error) {
1085 error = copyout(osetp, uap->oset, sizeof(oset));
1086 }
1087 return (error);
1088 }
1089
1090 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1091 #ifndef _SYS_SYSPROTO_H_
1092 struct osigprocmask_args {
1093 int how;
1094 osigset_t mask;
1095 };
1096 #endif
1097 int
1098 osigprocmask(td, uap)
1099 register struct thread *td;
1100 struct osigprocmask_args *uap;
1101 {
1102 sigset_t set, oset;
1103 int error;
1104
1105 OSIG2SIG(uap->mask, set);
1106 error = kern_sigprocmask(td, uap->how, &set, &oset, 1);
1107 SIG2OSIG(oset, td->td_retval[0]);
1108 return (error);
1109 }
1110 #endif /* COMPAT_43 */
1111
1112 int
1113 sys_sigwait(struct thread *td, struct sigwait_args *uap)
1114 {
1115 ksiginfo_t ksi;
1116 sigset_t set;
1117 int error;
1118
1119 error = copyin(uap->set, &set, sizeof(set));
1120 if (error) {
1121 td->td_retval[0] = error;
1122 return (0);
1123 }
1124
1125 error = kern_sigtimedwait(td, set, &ksi, NULL);
1126 if (error) {
1127 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT)
1128 error = ERESTART;
1129 if (error == ERESTART)
1130 return (error);
1131 td->td_retval[0] = error;
1132 return (0);
1133 }
1134
1135 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo));
1136 td->td_retval[0] = error;
1137 return (0);
1138 }
1139
1140 int
1141 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap)
1142 {
1143 struct timespec ts;
1144 struct timespec *timeout;
1145 sigset_t set;
1146 ksiginfo_t ksi;
1147 int error;
1148
1149 if (uap->timeout) {
1150 error = copyin(uap->timeout, &ts, sizeof(ts));
1151 if (error)
1152 return (error);
1153
1154 timeout = &ts;
1155 } else
1156 timeout = NULL;
1157
1158 error = copyin(uap->set, &set, sizeof(set));
1159 if (error)
1160 return (error);
1161
1162 error = kern_sigtimedwait(td, set, &ksi, timeout);
1163 if (error)
1164 return (error);
1165
1166 if (uap->info)
1167 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t));
1168
1169 if (error == 0)
1170 td->td_retval[0] = ksi.ksi_signo;
1171 return (error);
1172 }
1173
1174 int
1175 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap)
1176 {
1177 ksiginfo_t ksi;
1178 sigset_t set;
1179 int error;
1180
1181 error = copyin(uap->set, &set, sizeof(set));
1182 if (error)
1183 return (error);
1184
1185 error = kern_sigtimedwait(td, set, &ksi, NULL);
1186 if (error)
1187 return (error);
1188
1189 if (uap->info)
1190 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t));
1191
1192 if (error == 0)
1193 td->td_retval[0] = ksi.ksi_signo;
1194 return (error);
1195 }
1196
1197 int
1198 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi,
1199 struct timespec *timeout)
1200 {
1201 struct sigacts *ps;
1202 sigset_t saved_mask, new_block;
1203 struct proc *p;
1204 int error, sig, timo, timevalid = 0;
1205 struct timespec rts, ets, ts;
1206 struct timeval tv;
1207
1208 p = td->td_proc;
1209 error = 0;
1210 ets.tv_sec = 0;
1211 ets.tv_nsec = 0;
1212
1213 if (timeout != NULL) {
1214 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) {
1215 timevalid = 1;
1216 getnanouptime(&rts);
1217 ets = rts;
1218 timespecadd(&ets, timeout);
1219 }
1220 }
1221 ksiginfo_init(ksi);
1222 /* Some signals can not be waited for. */
1223 SIG_CANTMASK(waitset);
1224 ps = p->p_sigacts;
1225 PROC_LOCK(p);
1226 saved_mask = td->td_sigmask;
1227 SIGSETNAND(td->td_sigmask, waitset);
1228 for (;;) {
1229 mtx_lock(&ps->ps_mtx);
1230 sig = cursig(td);
1231 mtx_unlock(&ps->ps_mtx);
1232 if (sig != 0 && SIGISMEMBER(waitset, sig)) {
1233 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 ||
1234 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) {
1235 error = 0;
1236 break;
1237 }
1238 }
1239
1240 if (error != 0)
1241 break;
1242
1243 /*
1244 * POSIX says this must be checked after looking for pending
1245 * signals.
1246 */
1247 if (timeout != NULL) {
1248 if (!timevalid) {
1249 error = EINVAL;
1250 break;
1251 }
1252 getnanouptime(&rts);
1253 if (timespeccmp(&rts, &ets, >=)) {
1254 error = EAGAIN;
1255 break;
1256 }
1257 ts = ets;
1258 timespecsub(&ts, &rts);
1259 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1260 timo = tvtohz(&tv);
1261 } else {
1262 timo = 0;
1263 }
1264
1265 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo);
1266
1267 if (timeout != NULL) {
1268 if (error == ERESTART) {
1269 /* Timeout can not be restarted. */
1270 error = EINTR;
1271 } else if (error == EAGAIN) {
1272 /* We will calculate timeout by ourself. */
1273 error = 0;
1274 }
1275 }
1276 }
1277
1278 new_block = saved_mask;
1279 SIGSETNAND(new_block, td->td_sigmask);
1280 td->td_sigmask = saved_mask;
1281 /*
1282 * Fewer signals can be delivered to us, reschedule signal
1283 * notification.
1284 */
1285 if (p->p_numthreads != 1)
1286 reschedule_signals(p, new_block, 0);
1287
1288 if (error == 0) {
1289 SDT_PROBE(proc, kernel, , signal__clear, sig, ksi, 0, 0, 0);
1290
1291 if (ksi->ksi_code == SI_TIMER)
1292 itimer_accept(p, ksi->ksi_timerid, ksi);
1293
1294 #ifdef KTRACE
1295 if (KTRPOINT(td, KTR_PSIG)) {
1296 sig_t action;
1297
1298 mtx_lock(&ps->ps_mtx);
1299 action = ps->ps_sigact[_SIG_IDX(sig)];
1300 mtx_unlock(&ps->ps_mtx);
1301 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code);
1302 }
1303 #endif
1304 if (sig == SIGKILL)
1305 sigexit(td, sig);
1306 }
1307 PROC_UNLOCK(p);
1308 return (error);
1309 }
1310
1311 #ifndef _SYS_SYSPROTO_H_
1312 struct sigpending_args {
1313 sigset_t *set;
1314 };
1315 #endif
1316 int
1317 sys_sigpending(td, uap)
1318 struct thread *td;
1319 struct sigpending_args *uap;
1320 {
1321 struct proc *p = td->td_proc;
1322 sigset_t pending;
1323
1324 PROC_LOCK(p);
1325 pending = p->p_sigqueue.sq_signals;
1326 SIGSETOR(pending, td->td_sigqueue.sq_signals);
1327 PROC_UNLOCK(p);
1328 return (copyout(&pending, uap->set, sizeof(sigset_t)));
1329 }
1330
1331 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1332 #ifndef _SYS_SYSPROTO_H_
1333 struct osigpending_args {
1334 int dummy;
1335 };
1336 #endif
1337 int
1338 osigpending(td, uap)
1339 struct thread *td;
1340 struct osigpending_args *uap;
1341 {
1342 struct proc *p = td->td_proc;
1343 sigset_t pending;
1344
1345 PROC_LOCK(p);
1346 pending = p->p_sigqueue.sq_signals;
1347 SIGSETOR(pending, td->td_sigqueue.sq_signals);
1348 PROC_UNLOCK(p);
1349 SIG2OSIG(pending, td->td_retval[0]);
1350 return (0);
1351 }
1352 #endif /* COMPAT_43 */
1353
1354 #if defined(COMPAT_43)
1355 /*
1356 * Generalized interface signal handler, 4.3-compatible.
1357 */
1358 #ifndef _SYS_SYSPROTO_H_
1359 struct osigvec_args {
1360 int signum;
1361 struct sigvec *nsv;
1362 struct sigvec *osv;
1363 };
1364 #endif
1365 /* ARGSUSED */
1366 int
1367 osigvec(td, uap)
1368 struct thread *td;
1369 register struct osigvec_args *uap;
1370 {
1371 struct sigvec vec;
1372 struct sigaction nsa, osa;
1373 register struct sigaction *nsap, *osap;
1374 int error;
1375
1376 if (uap->signum <= 0 || uap->signum >= ONSIG)
1377 return (EINVAL);
1378 nsap = (uap->nsv != NULL) ? &nsa : NULL;
1379 osap = (uap->osv != NULL) ? &osa : NULL;
1380 if (nsap) {
1381 error = copyin(uap->nsv, &vec, sizeof(vec));
1382 if (error)
1383 return (error);
1384 nsap->sa_handler = vec.sv_handler;
1385 OSIG2SIG(vec.sv_mask, nsap->sa_mask);
1386 nsap->sa_flags = vec.sv_flags;
1387 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */
1388 }
1389 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
1390 if (osap && !error) {
1391 vec.sv_handler = osap->sa_handler;
1392 SIG2OSIG(osap->sa_mask, vec.sv_mask);
1393 vec.sv_flags = osap->sa_flags;
1394 vec.sv_flags &= ~SA_NOCLDWAIT;
1395 vec.sv_flags ^= SA_RESTART;
1396 error = copyout(&vec, uap->osv, sizeof(vec));
1397 }
1398 return (error);
1399 }
1400
1401 #ifndef _SYS_SYSPROTO_H_
1402 struct osigblock_args {
1403 int mask;
1404 };
1405 #endif
1406 int
1407 osigblock(td, uap)
1408 register struct thread *td;
1409 struct osigblock_args *uap;
1410 {
1411 sigset_t set, oset;
1412
1413 OSIG2SIG(uap->mask, set);
1414 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0);
1415 SIG2OSIG(oset, td->td_retval[0]);
1416 return (0);
1417 }
1418
1419 #ifndef _SYS_SYSPROTO_H_
1420 struct osigsetmask_args {
1421 int mask;
1422 };
1423 #endif
1424 int
1425 osigsetmask(td, uap)
1426 struct thread *td;
1427 struct osigsetmask_args *uap;
1428 {
1429 sigset_t set, oset;
1430
1431 OSIG2SIG(uap->mask, set);
1432 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0);
1433 SIG2OSIG(oset, td->td_retval[0]);
1434 return (0);
1435 }
1436 #endif /* COMPAT_43 */
1437
1438 /*
1439 * Suspend calling thread until signal, providing mask to be set in the
1440 * meantime.
1441 */
1442 #ifndef _SYS_SYSPROTO_H_
1443 struct sigsuspend_args {
1444 const sigset_t *sigmask;
1445 };
1446 #endif
1447 /* ARGSUSED */
1448 int
1449 sys_sigsuspend(td, uap)
1450 struct thread *td;
1451 struct sigsuspend_args *uap;
1452 {
1453 sigset_t mask;
1454 int error;
1455
1456 error = copyin(uap->sigmask, &mask, sizeof(mask));
1457 if (error)
1458 return (error);
1459 return (kern_sigsuspend(td, mask));
1460 }
1461
1462 int
1463 kern_sigsuspend(struct thread *td, sigset_t mask)
1464 {
1465 struct proc *p = td->td_proc;
1466 int has_sig, sig;
1467
1468 /*
1469 * When returning from sigsuspend, we want
1470 * the old mask to be restored after the
1471 * signal handler has finished. Thus, we
1472 * save it here and mark the sigacts structure
1473 * to indicate this.
1474 */
1475 PROC_LOCK(p);
1476 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask,
1477 SIGPROCMASK_PROC_LOCKED);
1478 td->td_pflags |= TDP_OLDMASK;
1479
1480 /*
1481 * Process signals now. Otherwise, we can get spurious wakeup
1482 * due to signal entered process queue, but delivered to other
1483 * thread. But sigsuspend should return only on signal
1484 * delivery.
1485 */
1486 (p->p_sysent->sv_set_syscall_retval)(td, EINTR);
1487 for (has_sig = 0; !has_sig;) {
1488 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause",
1489 0) == 0)
1490 /* void */;
1491 thread_suspend_check(0);
1492 mtx_lock(&p->p_sigacts->ps_mtx);
1493 while ((sig = cursig(td)) != 0)
1494 has_sig += postsig(sig);
1495 mtx_unlock(&p->p_sigacts->ps_mtx);
1496 }
1497 PROC_UNLOCK(p);
1498 td->td_errno = EINTR;
1499 td->td_pflags |= TDP_NERRNO;
1500 return (EJUSTRETURN);
1501 }
1502
1503 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1504 /*
1505 * Compatibility sigsuspend call for old binaries. Note nonstandard calling
1506 * convention: libc stub passes mask, not pointer, to save a copyin.
1507 */
1508 #ifndef _SYS_SYSPROTO_H_
1509 struct osigsuspend_args {
1510 osigset_t mask;
1511 };
1512 #endif
1513 /* ARGSUSED */
1514 int
1515 osigsuspend(td, uap)
1516 struct thread *td;
1517 struct osigsuspend_args *uap;
1518 {
1519 sigset_t mask;
1520
1521 OSIG2SIG(uap->mask, mask);
1522 return (kern_sigsuspend(td, mask));
1523 }
1524 #endif /* COMPAT_43 */
1525
1526 #if defined(COMPAT_43)
1527 #ifndef _SYS_SYSPROTO_H_
1528 struct osigstack_args {
1529 struct sigstack *nss;
1530 struct sigstack *oss;
1531 };
1532 #endif
1533 /* ARGSUSED */
1534 int
1535 osigstack(td, uap)
1536 struct thread *td;
1537 register struct osigstack_args *uap;
1538 {
1539 struct sigstack nss, oss;
1540 int error = 0;
1541
1542 if (uap->nss != NULL) {
1543 error = copyin(uap->nss, &nss, sizeof(nss));
1544 if (error)
1545 return (error);
1546 }
1547 oss.ss_sp = td->td_sigstk.ss_sp;
1548 oss.ss_onstack = sigonstack(cpu_getstack(td));
1549 if (uap->nss != NULL) {
1550 td->td_sigstk.ss_sp = nss.ss_sp;
1551 td->td_sigstk.ss_size = 0;
1552 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK;
1553 td->td_pflags |= TDP_ALTSTACK;
1554 }
1555 if (uap->oss != NULL)
1556 error = copyout(&oss, uap->oss, sizeof(oss));
1557
1558 return (error);
1559 }
1560 #endif /* COMPAT_43 */
1561
1562 #ifndef _SYS_SYSPROTO_H_
1563 struct sigaltstack_args {
1564 stack_t *ss;
1565 stack_t *oss;
1566 };
1567 #endif
1568 /* ARGSUSED */
1569 int
1570 sys_sigaltstack(td, uap)
1571 struct thread *td;
1572 register struct sigaltstack_args *uap;
1573 {
1574 stack_t ss, oss;
1575 int error;
1576
1577 if (uap->ss != NULL) {
1578 error = copyin(uap->ss, &ss, sizeof(ss));
1579 if (error)
1580 return (error);
1581 }
1582 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL,
1583 (uap->oss != NULL) ? &oss : NULL);
1584 if (error)
1585 return (error);
1586 if (uap->oss != NULL)
1587 error = copyout(&oss, uap->oss, sizeof(stack_t));
1588 return (error);
1589 }
1590
1591 int
1592 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss)
1593 {
1594 struct proc *p = td->td_proc;
1595 int oonstack;
1596
1597 oonstack = sigonstack(cpu_getstack(td));
1598
1599 if (oss != NULL) {
1600 *oss = td->td_sigstk;
1601 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK)
1602 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
1603 }
1604
1605 if (ss != NULL) {
1606 if (oonstack)
1607 return (EPERM);
1608 if ((ss->ss_flags & ~SS_DISABLE) != 0)
1609 return (EINVAL);
1610 if (!(ss->ss_flags & SS_DISABLE)) {
1611 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
1612 return (ENOMEM);
1613
1614 td->td_sigstk = *ss;
1615 td->td_pflags |= TDP_ALTSTACK;
1616 } else {
1617 td->td_pflags &= ~TDP_ALTSTACK;
1618 }
1619 }
1620 return (0);
1621 }
1622
1623 /*
1624 * Common code for kill process group/broadcast kill.
1625 * cp is calling process.
1626 */
1627 static int
1628 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi)
1629 {
1630 struct proc *p;
1631 struct pgrp *pgrp;
1632 int err;
1633 int ret;
1634
1635 ret = ESRCH;
1636 if (all) {
1637 /*
1638 * broadcast
1639 */
1640 sx_slock(&allproc_lock);
1641 FOREACH_PROC_IN_SYSTEM(p) {
1642 PROC_LOCK(p);
1643 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
1644 p == td->td_proc || p->p_state == PRS_NEW) {
1645 PROC_UNLOCK(p);
1646 continue;
1647 }
1648 err = p_cansignal(td, p, sig);
1649 if (err == 0) {
1650 if (sig)
1651 pksignal(p, sig, ksi);
1652 ret = err;
1653 }
1654 else if (ret == ESRCH)
1655 ret = err;
1656 PROC_UNLOCK(p);
1657 }
1658 sx_sunlock(&allproc_lock);
1659 } else {
1660 sx_slock(&proctree_lock);
1661 if (pgid == 0) {
1662 /*
1663 * zero pgid means send to my process group.
1664 */
1665 pgrp = td->td_proc->p_pgrp;
1666 PGRP_LOCK(pgrp);
1667 } else {
1668 pgrp = pgfind(pgid);
1669 if (pgrp == NULL) {
1670 sx_sunlock(&proctree_lock);
1671 return (ESRCH);
1672 }
1673 }
1674 sx_sunlock(&proctree_lock);
1675 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
1676 PROC_LOCK(p);
1677 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
1678 p->p_state == PRS_NEW) {
1679 PROC_UNLOCK(p);
1680 continue;
1681 }
1682 err = p_cansignal(td, p, sig);
1683 if (err == 0) {
1684 if (sig)
1685 pksignal(p, sig, ksi);
1686 ret = err;
1687 }
1688 else if (ret == ESRCH)
1689 ret = err;
1690 PROC_UNLOCK(p);
1691 }
1692 PGRP_UNLOCK(pgrp);
1693 }
1694 return (ret);
1695 }
1696
1697 #ifndef _SYS_SYSPROTO_H_
1698 struct kill_args {
1699 int pid;
1700 int signum;
1701 };
1702 #endif
1703 /* ARGSUSED */
1704 int
1705 sys_kill(struct thread *td, struct kill_args *uap)
1706 {
1707 ksiginfo_t ksi;
1708 struct proc *p;
1709 int error;
1710
1711 /*
1712 * A process in capability mode can send signals only to himself.
1713 * The main rationale behind this is that abort(3) is implemented as
1714 * kill(getpid(), SIGABRT).
1715 */
1716 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid)
1717 return (ECAPMODE);
1718
1719 AUDIT_ARG_SIGNUM(uap->signum);
1720 AUDIT_ARG_PID(uap->pid);
1721 if ((u_int)uap->signum > _SIG_MAXSIG)
1722 return (EINVAL);
1723
1724 ksiginfo_init(&ksi);
1725 ksi.ksi_signo = uap->signum;
1726 ksi.ksi_code = SI_USER;
1727 ksi.ksi_pid = td->td_proc->p_pid;
1728 ksi.ksi_uid = td->td_ucred->cr_ruid;
1729
1730 if (uap->pid > 0) {
1731 /* kill single process */
1732 if ((p = pfind(uap->pid)) == NULL) {
1733 if ((p = zpfind(uap->pid)) == NULL)
1734 return (ESRCH);
1735 }
1736 AUDIT_ARG_PROCESS(p);
1737 error = p_cansignal(td, p, uap->signum);
1738 if (error == 0 && uap->signum)
1739 pksignal(p, uap->signum, &ksi);
1740 PROC_UNLOCK(p);
1741 return (error);
1742 }
1743 switch (uap->pid) {
1744 case -1: /* broadcast signal */
1745 return (killpg1(td, uap->signum, 0, 1, &ksi));
1746 case 0: /* signal own process group */
1747 return (killpg1(td, uap->signum, 0, 0, &ksi));
1748 default: /* negative explicit process group */
1749 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi));
1750 }
1751 /* NOTREACHED */
1752 }
1753
1754 int
1755 sys_pdkill(td, uap)
1756 struct thread *td;
1757 struct pdkill_args *uap;
1758 {
1759 #ifdef PROCDESC
1760 struct proc *p;
1761 cap_rights_t rights;
1762 int error;
1763
1764 AUDIT_ARG_SIGNUM(uap->signum);
1765 AUDIT_ARG_FD(uap->fd);
1766 if ((u_int)uap->signum > _SIG_MAXSIG)
1767 return (EINVAL);
1768
1769 error = procdesc_find(td, uap->fd,
1770 cap_rights_init(&rights, CAP_PDKILL), &p);
1771 if (error)
1772 return (error);
1773 AUDIT_ARG_PROCESS(p);
1774 error = p_cansignal(td, p, uap->signum);
1775 if (error == 0 && uap->signum)
1776 kern_psignal(p, uap->signum);
1777 PROC_UNLOCK(p);
1778 return (error);
1779 #else
1780 return (ENOSYS);
1781 #endif
1782 }
1783
1784 #if defined(COMPAT_43)
1785 #ifndef _SYS_SYSPROTO_H_
1786 struct okillpg_args {
1787 int pgid;
1788 int signum;
1789 };
1790 #endif
1791 /* ARGSUSED */
1792 int
1793 okillpg(struct thread *td, struct okillpg_args *uap)
1794 {
1795 ksiginfo_t ksi;
1796
1797 AUDIT_ARG_SIGNUM(uap->signum);
1798 AUDIT_ARG_PID(uap->pgid);
1799 if ((u_int)uap->signum > _SIG_MAXSIG)
1800 return (EINVAL);
1801
1802 ksiginfo_init(&ksi);
1803 ksi.ksi_signo = uap->signum;
1804 ksi.ksi_code = SI_USER;
1805 ksi.ksi_pid = td->td_proc->p_pid;
1806 ksi.ksi_uid = td->td_ucred->cr_ruid;
1807 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi));
1808 }
1809 #endif /* COMPAT_43 */
1810
1811 #ifndef _SYS_SYSPROTO_H_
1812 struct sigqueue_args {
1813 pid_t pid;
1814 int signum;
1815 /* union sigval */ void *value;
1816 };
1817 #endif
1818 int
1819 sys_sigqueue(struct thread *td, struct sigqueue_args *uap)
1820 {
1821 ksiginfo_t ksi;
1822 struct proc *p;
1823 int error;
1824
1825 if ((u_int)uap->signum > _SIG_MAXSIG)
1826 return (EINVAL);
1827
1828 /*
1829 * Specification says sigqueue can only send signal to
1830 * single process.
1831 */
1832 if (uap->pid <= 0)
1833 return (EINVAL);
1834
1835 if ((p = pfind(uap->pid)) == NULL) {
1836 if ((p = zpfind(uap->pid)) == NULL)
1837 return (ESRCH);
1838 }
1839 error = p_cansignal(td, p, uap->signum);
1840 if (error == 0 && uap->signum != 0) {
1841 ksiginfo_init(&ksi);
1842 ksi.ksi_flags = KSI_SIGQ;
1843 ksi.ksi_signo = uap->signum;
1844 ksi.ksi_code = SI_QUEUE;
1845 ksi.ksi_pid = td->td_proc->p_pid;
1846 ksi.ksi_uid = td->td_ucred->cr_ruid;
1847 ksi.ksi_value.sival_ptr = uap->value;
1848 error = pksignal(p, ksi.ksi_signo, &ksi);
1849 }
1850 PROC_UNLOCK(p);
1851 return (error);
1852 }
1853
1854 /*
1855 * Send a signal to a process group.
1856 */
1857 void
1858 gsignal(int pgid, int sig, ksiginfo_t *ksi)
1859 {
1860 struct pgrp *pgrp;
1861
1862 if (pgid != 0) {
1863 sx_slock(&proctree_lock);
1864 pgrp = pgfind(pgid);
1865 sx_sunlock(&proctree_lock);
1866 if (pgrp != NULL) {
1867 pgsignal(pgrp, sig, 0, ksi);
1868 PGRP_UNLOCK(pgrp);
1869 }
1870 }
1871 }
1872
1873 /*
1874 * Send a signal to a process group. If checktty is 1,
1875 * limit to members which have a controlling terminal.
1876 */
1877 void
1878 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi)
1879 {
1880 struct proc *p;
1881
1882 if (pgrp) {
1883 PGRP_LOCK_ASSERT(pgrp, MA_OWNED);
1884 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
1885 PROC_LOCK(p);
1886 if (p->p_state == PRS_NORMAL &&
1887 (checkctty == 0 || p->p_flag & P_CONTROLT))
1888 pksignal(p, sig, ksi);
1889 PROC_UNLOCK(p);
1890 }
1891 }
1892 }
1893
1894 /*
1895 * Send a signal caused by a trap to the current thread. If it will be
1896 * caught immediately, deliver it with correct code. Otherwise, post it
1897 * normally.
1898 */
1899 void
1900 trapsignal(struct thread *td, ksiginfo_t *ksi)
1901 {
1902 struct sigacts *ps;
1903 sigset_t mask;
1904 struct proc *p;
1905 int sig;
1906 int code;
1907
1908 p = td->td_proc;
1909 sig = ksi->ksi_signo;
1910 code = ksi->ksi_code;
1911 KASSERT(_SIG_VALID(sig), ("invalid signal"));
1912
1913 PROC_LOCK(p);
1914 ps = p->p_sigacts;
1915 mtx_lock(&ps->ps_mtx);
1916 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) &&
1917 !SIGISMEMBER(td->td_sigmask, sig)) {
1918 td->td_ru.ru_nsignals++;
1919 #ifdef KTRACE
1920 if (KTRPOINT(curthread, KTR_PSIG))
1921 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)],
1922 &td->td_sigmask, code);
1923 #endif
1924 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)],
1925 ksi, &td->td_sigmask);
1926 mask = ps->ps_catchmask[_SIG_IDX(sig)];
1927 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1928 SIGADDSET(mask, sig);
1929 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL,
1930 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED);
1931 if (SIGISMEMBER(ps->ps_sigreset, sig))
1932 sigdflt(ps, sig);
1933 mtx_unlock(&ps->ps_mtx);
1934 } else {
1935 /*
1936 * Avoid a possible infinite loop if the thread
1937 * masking the signal or process is ignoring the
1938 * signal.
1939 */
1940 if (kern_forcesigexit &&
1941 (SIGISMEMBER(td->td_sigmask, sig) ||
1942 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) {
1943 SIGDELSET(td->td_sigmask, sig);
1944 SIGDELSET(ps->ps_sigcatch, sig);
1945 SIGDELSET(ps->ps_sigignore, sig);
1946 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1947 }
1948 mtx_unlock(&ps->ps_mtx);
1949 p->p_code = code; /* XXX for core dump/debugger */
1950 p->p_sig = sig; /* XXX to verify code */
1951 tdsendsignal(p, td, sig, ksi);
1952 }
1953 PROC_UNLOCK(p);
1954 }
1955
1956 static struct thread *
1957 sigtd(struct proc *p, int sig, int prop)
1958 {
1959 struct thread *td, *signal_td;
1960
1961 PROC_LOCK_ASSERT(p, MA_OWNED);
1962
1963 /*
1964 * Check if current thread can handle the signal without
1965 * switching context to another thread.
1966 */
1967 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig))
1968 return (curthread);
1969 signal_td = NULL;
1970 FOREACH_THREAD_IN_PROC(p, td) {
1971 if (!SIGISMEMBER(td->td_sigmask, sig)) {
1972 signal_td = td;
1973 break;
1974 }
1975 }
1976 if (signal_td == NULL)
1977 signal_td = FIRST_THREAD_IN_PROC(p);
1978 return (signal_td);
1979 }
1980
1981 /*
1982 * Send the signal to the process. If the signal has an action, the action
1983 * is usually performed by the target process rather than the caller; we add
1984 * the signal to the set of pending signals for the process.
1985 *
1986 * Exceptions:
1987 * o When a stop signal is sent to a sleeping process that takes the
1988 * default action, the process is stopped without awakening it.
1989 * o SIGCONT restarts stopped processes (or puts them back to sleep)
1990 * regardless of the signal action (eg, blocked or ignored).
1991 *
1992 * Other ignored signals are discarded immediately.
1993 *
1994 * NB: This function may be entered from the debugger via the "kill" DDB
1995 * command. There is little that can be done to mitigate the possibly messy
1996 * side effects of this unwise possibility.
1997 */
1998 void
1999 kern_psignal(struct proc *p, int sig)
2000 {
2001 ksiginfo_t ksi;
2002
2003 ksiginfo_init(&ksi);
2004 ksi.ksi_signo = sig;
2005 ksi.ksi_code = SI_KERNEL;
2006 (void) tdsendsignal(p, NULL, sig, &ksi);
2007 }
2008
2009 int
2010 pksignal(struct proc *p, int sig, ksiginfo_t *ksi)
2011 {
2012
2013 return (tdsendsignal(p, NULL, sig, ksi));
2014 }
2015
2016 /* Utility function for finding a thread to send signal event to. */
2017 int
2018 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd)
2019 {
2020 struct thread *td;
2021
2022 if (sigev->sigev_notify == SIGEV_THREAD_ID) {
2023 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid);
2024 if (td == NULL)
2025 return (ESRCH);
2026 *ttd = td;
2027 } else {
2028 *ttd = NULL;
2029 PROC_LOCK(p);
2030 }
2031 return (0);
2032 }
2033
2034 void
2035 tdsignal(struct thread *td, int sig)
2036 {
2037 ksiginfo_t ksi;
2038
2039 ksiginfo_init(&ksi);
2040 ksi.ksi_signo = sig;
2041 ksi.ksi_code = SI_KERNEL;
2042 (void) tdsendsignal(td->td_proc, td, sig, &ksi);
2043 }
2044
2045 void
2046 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi)
2047 {
2048
2049 (void) tdsendsignal(td->td_proc, td, sig, ksi);
2050 }
2051
2052 int
2053 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi)
2054 {
2055 sig_t action;
2056 sigqueue_t *sigqueue;
2057 int prop;
2058 struct sigacts *ps;
2059 int intrval;
2060 int ret = 0;
2061 int wakeup_swapper;
2062
2063 MPASS(td == NULL || p == td->td_proc);
2064 PROC_LOCK_ASSERT(p, MA_OWNED);
2065
2066 if (!_SIG_VALID(sig))
2067 panic("%s(): invalid signal %d", __func__, sig);
2068
2069 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__));
2070
2071 /*
2072 * IEEE Std 1003.1-2001: return success when killing a zombie.
2073 */
2074 if (p->p_state == PRS_ZOMBIE) {
2075 if (ksi && (ksi->ksi_flags & KSI_INS))
2076 ksiginfo_tryfree(ksi);
2077 return (ret);
2078 }
2079
2080 ps = p->p_sigacts;
2081 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig);
2082 prop = sigprop(sig);
2083
2084 if (td == NULL) {
2085 td = sigtd(p, sig, prop);
2086 sigqueue = &p->p_sigqueue;
2087 } else
2088 sigqueue = &td->td_sigqueue;
2089
2090 SDT_PROBE(proc, kernel, , signal__send, td, p, sig, 0, 0 );
2091
2092 /*
2093 * If the signal is being ignored,
2094 * then we forget about it immediately.
2095 * (Note: we don't set SIGCONT in ps_sigignore,
2096 * and if it is set to SIG_IGN,
2097 * action will be SIG_DFL here.)
2098 */
2099 mtx_lock(&ps->ps_mtx);
2100 if (SIGISMEMBER(ps->ps_sigignore, sig)) {
2101 SDT_PROBE(proc, kernel, , signal__discard, td, p, sig, 0, 0 );
2102
2103 mtx_unlock(&ps->ps_mtx);
2104 if (ksi && (ksi->ksi_flags & KSI_INS))
2105 ksiginfo_tryfree(ksi);
2106 return (ret);
2107 }
2108 if (SIGISMEMBER(td->td_sigmask, sig))
2109 action = SIG_HOLD;
2110 else if (SIGISMEMBER(ps->ps_sigcatch, sig))
2111 action = SIG_CATCH;
2112 else
2113 action = SIG_DFL;
2114 if (SIGISMEMBER(ps->ps_sigintr, sig))
2115 intrval = EINTR;
2116 else
2117 intrval = ERESTART;
2118 mtx_unlock(&ps->ps_mtx);
2119
2120 if (prop & SA_CONT)
2121 sigqueue_delete_stopmask_proc(p);
2122 else if (prop & SA_STOP) {
2123 /*
2124 * If sending a tty stop signal to a member of an orphaned
2125 * process group, discard the signal here if the action
2126 * is default; don't stop the process below if sleeping,
2127 * and don't clear any pending SIGCONT.
2128 */
2129 if ((prop & SA_TTYSTOP) &&
2130 (p->p_pgrp->pg_jobc == 0) &&
2131 (action == SIG_DFL)) {
2132 if (ksi && (ksi->ksi_flags & KSI_INS))
2133 ksiginfo_tryfree(ksi);
2134 return (ret);
2135 }
2136 sigqueue_delete_proc(p, SIGCONT);
2137 if (p->p_flag & P_CONTINUED) {
2138 p->p_flag &= ~P_CONTINUED;
2139 PROC_LOCK(p->p_pptr);
2140 sigqueue_take(p->p_ksi);
2141 PROC_UNLOCK(p->p_pptr);
2142 }
2143 }
2144
2145 ret = sigqueue_add(sigqueue, sig, ksi);
2146 if (ret != 0)
2147 return (ret);
2148 signotify(td);
2149 /*
2150 * Defer further processing for signals which are held,
2151 * except that stopped processes must be continued by SIGCONT.
2152 */
2153 if (action == SIG_HOLD &&
2154 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG)))
2155 return (ret);
2156 /*
2157 * SIGKILL: Remove procfs STOPEVENTs.
2158 */
2159 if (sig == SIGKILL) {
2160 /* from procfs_ioctl.c: PIOCBIC */
2161 p->p_stops = 0;
2162 /* from procfs_ioctl.c: PIOCCONT */
2163 p->p_step = 0;
2164 wakeup(&p->p_step);
2165 }
2166 /*
2167 * Some signals have a process-wide effect and a per-thread
2168 * component. Most processing occurs when the process next
2169 * tries to cross the user boundary, however there are some
2170 * times when processing needs to be done immediately, such as
2171 * waking up threads so that they can cross the user boundary.
2172 * We try to do the per-process part here.
2173 */
2174 if (P_SHOULDSTOP(p)) {
2175 KASSERT(!(p->p_flag & P_WEXIT),
2176 ("signal to stopped but exiting process"));
2177 if (sig == SIGKILL) {
2178 /*
2179 * If traced process is already stopped,
2180 * then no further action is necessary.
2181 */
2182 if (p->p_flag & P_TRACED)
2183 goto out;
2184 /*
2185 * SIGKILL sets process running.
2186 * It will die elsewhere.
2187 * All threads must be restarted.
2188 */
2189 p->p_flag &= ~P_STOPPED_SIG;
2190 goto runfast;
2191 }
2192
2193 if (prop & SA_CONT) {
2194 /*
2195 * If traced process is already stopped,
2196 * then no further action is necessary.
2197 */
2198 if (p->p_flag & P_TRACED)
2199 goto out;
2200 /*
2201 * If SIGCONT is default (or ignored), we continue the
2202 * process but don't leave the signal in sigqueue as
2203 * it has no further action. If SIGCONT is held, we
2204 * continue the process and leave the signal in
2205 * sigqueue. If the process catches SIGCONT, let it
2206 * handle the signal itself. If it isn't waiting on
2207 * an event, it goes back to run state.
2208 * Otherwise, process goes back to sleep state.
2209 */
2210 p->p_flag &= ~P_STOPPED_SIG;
2211 PROC_SLOCK(p);
2212 if (p->p_numthreads == p->p_suspcount) {
2213 PROC_SUNLOCK(p);
2214 p->p_flag |= P_CONTINUED;
2215 p->p_xstat = SIGCONT;
2216 PROC_LOCK(p->p_pptr);
2217 childproc_continued(p);
2218 PROC_UNLOCK(p->p_pptr);
2219 PROC_SLOCK(p);
2220 }
2221 if (action == SIG_DFL) {
2222 thread_unsuspend(p);
2223 PROC_SUNLOCK(p);
2224 sigqueue_delete(sigqueue, sig);
2225 goto out;
2226 }
2227 if (action == SIG_CATCH) {
2228 /*
2229 * The process wants to catch it so it needs
2230 * to run at least one thread, but which one?
2231 */
2232 PROC_SUNLOCK(p);
2233 goto runfast;
2234 }
2235 /*
2236 * The signal is not ignored or caught.
2237 */
2238 thread_unsuspend(p);
2239 PROC_SUNLOCK(p);
2240 goto out;
2241 }
2242
2243 if (prop & SA_STOP) {
2244 /*
2245 * If traced process is already stopped,
2246 * then no further action is necessary.
2247 */
2248 if (p->p_flag & P_TRACED)
2249 goto out;
2250 /*
2251 * Already stopped, don't need to stop again
2252 * (If we did the shell could get confused).
2253 * Just make sure the signal STOP bit set.
2254 */
2255 p->p_flag |= P_STOPPED_SIG;
2256 sigqueue_delete(sigqueue, sig);
2257 goto out;
2258 }
2259
2260 /*
2261 * All other kinds of signals:
2262 * If a thread is sleeping interruptibly, simulate a
2263 * wakeup so that when it is continued it will be made
2264 * runnable and can look at the signal. However, don't make
2265 * the PROCESS runnable, leave it stopped.
2266 * It may run a bit until it hits a thread_suspend_check().
2267 */
2268 wakeup_swapper = 0;
2269 PROC_SLOCK(p);
2270 thread_lock(td);
2271 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR))
2272 wakeup_swapper = sleepq_abort(td, intrval);
2273 thread_unlock(td);
2274 PROC_SUNLOCK(p);
2275 if (wakeup_swapper)
2276 kick_proc0();
2277 goto out;
2278 /*
2279 * Mutexes are short lived. Threads waiting on them will
2280 * hit thread_suspend_check() soon.
2281 */
2282 } else if (p->p_state == PRS_NORMAL) {
2283 if (p->p_flag & P_TRACED || action == SIG_CATCH) {
2284 tdsigwakeup(td, sig, action, intrval);
2285 goto out;
2286 }
2287
2288 MPASS(action == SIG_DFL);
2289
2290 if (prop & SA_STOP) {
2291 if (p->p_flag & (P_PPWAIT|P_WEXIT))
2292 goto out;
2293 p->p_flag |= P_STOPPED_SIG;
2294 p->p_xstat = sig;
2295 PROC_SLOCK(p);
2296 sig_suspend_threads(td, p, 1);
2297 if (p->p_numthreads == p->p_suspcount) {
2298 /*
2299 * only thread sending signal to another
2300 * process can reach here, if thread is sending
2301 * signal to its process, because thread does
2302 * not suspend itself here, p_numthreads
2303 * should never be equal to p_suspcount.
2304 */
2305 thread_stopped(p);
2306 PROC_SUNLOCK(p);
2307 sigqueue_delete_proc(p, p->p_xstat);
2308 } else
2309 PROC_SUNLOCK(p);
2310 goto out;
2311 }
2312 } else {
2313 /* Not in "NORMAL" state. discard the signal. */
2314 sigqueue_delete(sigqueue, sig);
2315 goto out;
2316 }
2317
2318 /*
2319 * The process is not stopped so we need to apply the signal to all the
2320 * running threads.
2321 */
2322 runfast:
2323 tdsigwakeup(td, sig, action, intrval);
2324 PROC_SLOCK(p);
2325 thread_unsuspend(p);
2326 PROC_SUNLOCK(p);
2327 out:
2328 /* If we jump here, proc slock should not be owned. */
2329 PROC_SLOCK_ASSERT(p, MA_NOTOWNED);
2330 return (ret);
2331 }
2332
2333 /*
2334 * The force of a signal has been directed against a single
2335 * thread. We need to see what we can do about knocking it
2336 * out of any sleep it may be in etc.
2337 */
2338 static void
2339 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval)
2340 {
2341 struct proc *p = td->td_proc;
2342 register int prop;
2343 int wakeup_swapper;
2344
2345 wakeup_swapper = 0;
2346 PROC_LOCK_ASSERT(p, MA_OWNED);
2347 prop = sigprop(sig);
2348
2349 PROC_SLOCK(p);
2350 thread_lock(td);
2351 /*
2352 * Bring the priority of a thread up if we want it to get
2353 * killed in this lifetime.
2354 */
2355 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER)
2356 sched_prio(td, PUSER);
2357 if (TD_ON_SLEEPQ(td)) {
2358 /*
2359 * If thread is sleeping uninterruptibly
2360 * we can't interrupt the sleep... the signal will
2361 * be noticed when the process returns through
2362 * trap() or syscall().
2363 */
2364 if ((td->td_flags & TDF_SINTR) == 0)
2365 goto out;
2366 /*
2367 * If SIGCONT is default (or ignored) and process is
2368 * asleep, we are finished; the process should not
2369 * be awakened.
2370 */
2371 if ((prop & SA_CONT) && action == SIG_DFL) {
2372 thread_unlock(td);
2373 PROC_SUNLOCK(p);
2374 sigqueue_delete(&p->p_sigqueue, sig);
2375 /*
2376 * It may be on either list in this state.
2377 * Remove from both for now.
2378 */
2379 sigqueue_delete(&td->td_sigqueue, sig);
2380 return;
2381 }
2382
2383 /*
2384 * Don't awaken a sleeping thread for SIGSTOP if the
2385 * STOP signal is deferred.
2386 */
2387 if ((prop & SA_STOP) && (td->td_flags & TDF_SBDRY))
2388 goto out;
2389
2390 /*
2391 * Give low priority threads a better chance to run.
2392 */
2393 if (td->td_priority > PUSER)
2394 sched_prio(td, PUSER);
2395
2396 wakeup_swapper = sleepq_abort(td, intrval);
2397 } else {
2398 /*
2399 * Other states do nothing with the signal immediately,
2400 * other than kicking ourselves if we are running.
2401 * It will either never be noticed, or noticed very soon.
2402 */
2403 #ifdef SMP
2404 if (TD_IS_RUNNING(td) && td != curthread)
2405 forward_signal(td);
2406 #endif
2407 }
2408 out:
2409 PROC_SUNLOCK(p);
2410 thread_unlock(td);
2411 if (wakeup_swapper)
2412 kick_proc0();
2413 }
2414
2415 static void
2416 sig_suspend_threads(struct thread *td, struct proc *p, int sending)
2417 {
2418 struct thread *td2;
2419
2420 PROC_LOCK_ASSERT(p, MA_OWNED);
2421 PROC_SLOCK_ASSERT(p, MA_OWNED);
2422
2423 FOREACH_THREAD_IN_PROC(p, td2) {
2424 thread_lock(td2);
2425 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK;
2426 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) &&
2427 (td2->td_flags & TDF_SINTR)) {
2428 if (td2->td_flags & TDF_SBDRY) {
2429 /*
2430 * Once a thread is asleep with
2431 * TDF_SBDRY set, it should never
2432 * become suspended due to this check.
2433 */
2434 KASSERT(!TD_IS_SUSPENDED(td2),
2435 ("thread with deferred stops suspended"));
2436 } else if (!TD_IS_SUSPENDED(td2)) {
2437 thread_suspend_one(td2);
2438 }
2439 } else if (!TD_IS_SUSPENDED(td2)) {
2440 if (sending || td != td2)
2441 td2->td_flags |= TDF_ASTPENDING;
2442 #ifdef SMP
2443 if (TD_IS_RUNNING(td2) && td2 != td)
2444 forward_signal(td2);
2445 #endif
2446 }
2447 thread_unlock(td2);
2448 }
2449 }
2450
2451 int
2452 ptracestop(struct thread *td, int sig)
2453 {
2454 struct proc *p = td->td_proc;
2455
2456 PROC_LOCK_ASSERT(p, MA_OWNED);
2457 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process"));
2458 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
2459 &p->p_mtx.lock_object, "Stopping for traced signal");
2460
2461 td->td_dbgflags |= TDB_XSIG;
2462 td->td_xsig = sig;
2463 PROC_SLOCK(p);
2464 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) {
2465 if (p->p_flag & P_SINGLE_EXIT) {
2466 td->td_dbgflags &= ~TDB_XSIG;
2467 PROC_SUNLOCK(p);
2468 return (sig);
2469 }
2470 /*
2471 * Just make wait() to work, the last stopped thread
2472 * will win.
2473 */
2474 p->p_xstat = sig;
2475 p->p_xthread = td;
2476 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE);
2477 sig_suspend_threads(td, p, 0);
2478 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) {
2479 td->td_dbgflags &= ~TDB_STOPATFORK;
2480 cv_broadcast(&p->p_dbgwait);
2481 }
2482 stopme:
2483 thread_suspend_switch(td);
2484 if (p->p_xthread == td)
2485 p->p_xthread = NULL;
2486 if (!(p->p_flag & P_TRACED))
2487 break;
2488 if (td->td_dbgflags & TDB_SUSPEND) {
2489 if (p->p_flag & P_SINGLE_EXIT)
2490 break;
2491 goto stopme;
2492 }
2493 }
2494 PROC_SUNLOCK(p);
2495 return (td->td_xsig);
2496 }
2497
2498 static void
2499 reschedule_signals(struct proc *p, sigset_t block, int flags)
2500 {
2501 struct sigacts *ps;
2502 struct thread *td;
2503 int sig;
2504
2505 PROC_LOCK_ASSERT(p, MA_OWNED);
2506 if (SIGISEMPTY(p->p_siglist))
2507 return;
2508 ps = p->p_sigacts;
2509 SIGSETAND(block, p->p_siglist);
2510 while ((sig = sig_ffs(&block)) != 0) {
2511 SIGDELSET(block, sig);
2512 td = sigtd(p, sig, 0);
2513 signotify(td);
2514 if (!(flags & SIGPROCMASK_PS_LOCKED))
2515 mtx_lock(&ps->ps_mtx);
2516 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig))
2517 tdsigwakeup(td, sig, SIG_CATCH,
2518 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR :
2519 ERESTART));
2520 if (!(flags & SIGPROCMASK_PS_LOCKED))
2521 mtx_unlock(&ps->ps_mtx);
2522 }
2523 }
2524
2525 void
2526 tdsigcleanup(struct thread *td)
2527 {
2528 struct proc *p;
2529 sigset_t unblocked;
2530
2531 p = td->td_proc;
2532 PROC_LOCK_ASSERT(p, MA_OWNED);
2533
2534 sigqueue_flush(&td->td_sigqueue);
2535 if (p->p_numthreads == 1)
2536 return;
2537
2538 /*
2539 * Since we cannot handle signals, notify signal post code
2540 * about this by filling the sigmask.
2541 *
2542 * Also, if needed, wake up thread(s) that do not block the
2543 * same signals as the exiting thread, since the thread might
2544 * have been selected for delivery and woken up.
2545 */
2546 SIGFILLSET(unblocked);
2547 SIGSETNAND(unblocked, td->td_sigmask);
2548 SIGFILLSET(td->td_sigmask);
2549 reschedule_signals(p, unblocked, 0);
2550
2551 }
2552
2553 /*
2554 * Defer the delivery of SIGSTOP for the current thread. Returns true
2555 * if stops were deferred and false if they were already deferred.
2556 */
2557 int
2558 sigdeferstop(void)
2559 {
2560 struct thread *td;
2561
2562 td = curthread;
2563 if (td->td_flags & TDF_SBDRY)
2564 return (0);
2565 thread_lock(td);
2566 td->td_flags |= TDF_SBDRY;
2567 thread_unlock(td);
2568 return (1);
2569 }
2570
2571 /*
2572 * Permit the delivery of SIGSTOP for the current thread. This does
2573 * not immediately suspend if a stop was posted. Instead, the thread
2574 * will suspend either via ast() or a subsequent interruptible sleep.
2575 */
2576 void
2577 sigallowstop()
2578 {
2579 struct thread *td;
2580
2581 td = curthread;
2582 thread_lock(td);
2583 td->td_flags &= ~TDF_SBDRY;
2584 thread_unlock(td);
2585 }
2586
2587 /*
2588 * If the current process has received a signal (should be caught or cause
2589 * termination, should interrupt current syscall), return the signal number.
2590 * Stop signals with default action are processed immediately, then cleared;
2591 * they aren't returned. This is checked after each entry to the system for
2592 * a syscall or trap (though this can usually be done without calling issignal
2593 * by checking the pending signal masks in cursig.) The normal call
2594 * sequence is
2595 *
2596 * while (sig = cursig(curthread))
2597 * postsig(sig);
2598 */
2599 static int
2600 issignal(struct thread *td)
2601 {
2602 struct proc *p;
2603 struct sigacts *ps;
2604 struct sigqueue *queue;
2605 sigset_t sigpending;
2606 int sig, prop, newsig;
2607
2608 p = td->td_proc;
2609 ps = p->p_sigacts;
2610 mtx_assert(&ps->ps_mtx, MA_OWNED);
2611 PROC_LOCK_ASSERT(p, MA_OWNED);
2612 for (;;) {
2613 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
2614
2615 sigpending = td->td_sigqueue.sq_signals;
2616 SIGSETOR(sigpending, p->p_sigqueue.sq_signals);
2617 SIGSETNAND(sigpending, td->td_sigmask);
2618
2619 if (p->p_flag & P_PPWAIT || td->td_flags & TDF_SBDRY)
2620 SIG_STOPSIGMASK(sigpending);
2621 if (SIGISEMPTY(sigpending)) /* no signal to send */
2622 return (0);
2623 sig = sig_ffs(&sigpending);
2624
2625 if (p->p_stops & S_SIG) {
2626 mtx_unlock(&ps->ps_mtx);
2627 stopevent(p, S_SIG, sig);
2628 mtx_lock(&ps->ps_mtx);
2629 }
2630
2631 /*
2632 * We should see pending but ignored signals
2633 * only if P_TRACED was on when they were posted.
2634 */
2635 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) {
2636 sigqueue_delete(&td->td_sigqueue, sig);
2637 sigqueue_delete(&p->p_sigqueue, sig);
2638 continue;
2639 }
2640 if (p->p_flag & P_TRACED && (p->p_flag & P_PPTRACE) == 0) {
2641 /*
2642 * If traced, always stop.
2643 * Remove old signal from queue before the stop.
2644 * XXX shrug off debugger, it causes siginfo to
2645 * be thrown away.
2646 */
2647 queue = &td->td_sigqueue;
2648 td->td_dbgksi.ksi_signo = 0;
2649 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) {
2650 queue = &p->p_sigqueue;
2651 sigqueue_get(queue, sig, &td->td_dbgksi);
2652 }
2653
2654 mtx_unlock(&ps->ps_mtx);
2655 newsig = ptracestop(td, sig);
2656 mtx_lock(&ps->ps_mtx);
2657
2658 if (sig != newsig) {
2659
2660 /*
2661 * If parent wants us to take the signal,
2662 * then it will leave it in p->p_xstat;
2663 * otherwise we just look for signals again.
2664 */
2665 if (newsig == 0)
2666 continue;
2667 sig = newsig;
2668
2669 /*
2670 * Put the new signal into td_sigqueue. If the
2671 * signal is being masked, look for other
2672 * signals.
2673 */
2674 sigqueue_add(queue, sig, NULL);
2675 if (SIGISMEMBER(td->td_sigmask, sig))
2676 continue;
2677 signotify(td);
2678 } else {
2679 if (td->td_dbgksi.ksi_signo != 0) {
2680 td->td_dbgksi.ksi_flags |= KSI_HEAD;
2681 if (sigqueue_add(&td->td_sigqueue, sig,
2682 &td->td_dbgksi) != 0)
2683 td->td_dbgksi.ksi_signo = 0;
2684 }
2685 if (td->td_dbgksi.ksi_signo == 0)
2686 sigqueue_add(&td->td_sigqueue, sig,
2687 NULL);
2688 }
2689
2690 /*
2691 * If the traced bit got turned off, go back up
2692 * to the top to rescan signals. This ensures
2693 * that p_sig* and p_sigact are consistent.
2694 */
2695 if ((p->p_flag & P_TRACED) == 0)
2696 continue;
2697 }
2698
2699 prop = sigprop(sig);
2700
2701 /*
2702 * Decide whether the signal should be returned.
2703 * Return the signal's number, or fall through
2704 * to clear it from the pending mask.
2705 */
2706 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
2707
2708 case (intptr_t)SIG_DFL:
2709 /*
2710 * Don't take default actions on system processes.
2711 */
2712 if (p->p_pid <= 1) {
2713 #ifdef DIAGNOSTIC
2714 /*
2715 * Are you sure you want to ignore SIGSEGV
2716 * in init? XXX
2717 */
2718 printf("Process (pid %lu) got signal %d\n",
2719 (u_long)p->p_pid, sig);
2720 #endif
2721 break; /* == ignore */
2722 }
2723 /*
2724 * If there is a pending stop signal to process
2725 * with default action, stop here,
2726 * then clear the signal. However,
2727 * if process is member of an orphaned
2728 * process group, ignore tty stop signals.
2729 */
2730 if (prop & SA_STOP) {
2731 if (p->p_flag & (P_TRACED|P_WEXIT) ||
2732 (p->p_pgrp->pg_jobc == 0 &&
2733 prop & SA_TTYSTOP))
2734 break; /* == ignore */
2735 mtx_unlock(&ps->ps_mtx);
2736 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
2737 &p->p_mtx.lock_object, "Catching SIGSTOP");
2738 p->p_flag |= P_STOPPED_SIG;
2739 p->p_xstat = sig;
2740 PROC_SLOCK(p);
2741 sig_suspend_threads(td, p, 0);
2742 thread_suspend_switch(td);
2743 PROC_SUNLOCK(p);
2744 mtx_lock(&ps->ps_mtx);
2745 break;
2746 } else if (prop & SA_IGNORE) {
2747 /*
2748 * Except for SIGCONT, shouldn't get here.
2749 * Default action is to ignore; drop it.
2750 */
2751 break; /* == ignore */
2752 } else
2753 return (sig);
2754 /*NOTREACHED*/
2755
2756 case (intptr_t)SIG_IGN:
2757 /*
2758 * Masking above should prevent us ever trying
2759 * to take action on an ignored signal other
2760 * than SIGCONT, unless process is traced.
2761 */
2762 if ((prop & SA_CONT) == 0 &&
2763 (p->p_flag & P_TRACED) == 0)
2764 printf("issignal\n");
2765 break; /* == ignore */
2766
2767 default:
2768 /*
2769 * This signal has an action, let
2770 * postsig() process it.
2771 */
2772 return (sig);
2773 }
2774 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */
2775 sigqueue_delete(&p->p_sigqueue, sig);
2776 }
2777 /* NOTREACHED */
2778 }
2779
2780 void
2781 thread_stopped(struct proc *p)
2782 {
2783 int n;
2784
2785 PROC_LOCK_ASSERT(p, MA_OWNED);
2786 PROC_SLOCK_ASSERT(p, MA_OWNED);
2787 n = p->p_suspcount;
2788 if (p == curproc)
2789 n++;
2790 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) {
2791 PROC_SUNLOCK(p);
2792 p->p_flag &= ~P_WAITED;
2793 PROC_LOCK(p->p_pptr);
2794 childproc_stopped(p, (p->p_flag & P_TRACED) ?
2795 CLD_TRAPPED : CLD_STOPPED);
2796 PROC_UNLOCK(p->p_pptr);
2797 PROC_SLOCK(p);
2798 }
2799 }
2800
2801 /*
2802 * Take the action for the specified signal
2803 * from the current set of pending signals.
2804 */
2805 int
2806 postsig(sig)
2807 register int sig;
2808 {
2809 struct thread *td = curthread;
2810 register struct proc *p = td->td_proc;
2811 struct sigacts *ps;
2812 sig_t action;
2813 ksiginfo_t ksi;
2814 sigset_t returnmask, mask;
2815
2816 KASSERT(sig != 0, ("postsig"));
2817
2818 PROC_LOCK_ASSERT(p, MA_OWNED);
2819 ps = p->p_sigacts;
2820 mtx_assert(&ps->ps_mtx, MA_OWNED);
2821 ksiginfo_init(&ksi);
2822 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 &&
2823 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0)
2824 return (0);
2825 ksi.ksi_signo = sig;
2826 if (ksi.ksi_code == SI_TIMER)
2827 itimer_accept(p, ksi.ksi_timerid, &ksi);
2828 action = ps->ps_sigact[_SIG_IDX(sig)];
2829 #ifdef KTRACE
2830 if (KTRPOINT(td, KTR_PSIG))
2831 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ?
2832 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code);
2833 #endif
2834 if (p->p_stops & S_SIG) {
2835 mtx_unlock(&ps->ps_mtx);
2836 stopevent(p, S_SIG, sig);
2837 mtx_lock(&ps->ps_mtx);
2838 }
2839
2840 if (action == SIG_DFL) {
2841 /*
2842 * Default action, where the default is to kill
2843 * the process. (Other cases were ignored above.)
2844 */
2845 mtx_unlock(&ps->ps_mtx);
2846 sigexit(td, sig);
2847 /* NOTREACHED */
2848 } else {
2849 /*
2850 * If we get here, the signal must be caught.
2851 */
2852 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig),
2853 ("postsig action"));
2854 /*
2855 * Set the new mask value and also defer further
2856 * occurrences of this signal.
2857 *
2858 * Special case: user has done a sigsuspend. Here the
2859 * current mask is not of interest, but rather the
2860 * mask from before the sigsuspend is what we want
2861 * restored after the signal processing is completed.
2862 */
2863 if (td->td_pflags & TDP_OLDMASK) {
2864 returnmask = td->td_oldsigmask;
2865 td->td_pflags &= ~TDP_OLDMASK;
2866 } else
2867 returnmask = td->td_sigmask;
2868
2869 mask = ps->ps_catchmask[_SIG_IDX(sig)];
2870 if (!SIGISMEMBER(ps->ps_signodefer, sig))
2871 SIGADDSET(mask, sig);
2872 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL,
2873 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED);
2874
2875 if (SIGISMEMBER(ps->ps_sigreset, sig))
2876 sigdflt(ps, sig);
2877 td->td_ru.ru_nsignals++;
2878 if (p->p_sig == sig) {
2879 p->p_code = 0;
2880 p->p_sig = 0;
2881 }
2882 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask);
2883 }
2884 return (1);
2885 }
2886
2887 /*
2888 * Kill the current process for stated reason.
2889 */
2890 void
2891 killproc(p, why)
2892 struct proc *p;
2893 char *why;
2894 {
2895
2896 PROC_LOCK_ASSERT(p, MA_OWNED);
2897 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid,
2898 p->p_comm);
2899 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid,
2900 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why);
2901 p->p_flag |= P_WKILLED;
2902 kern_psignal(p, SIGKILL);
2903 }
2904
2905 /*
2906 * Force the current process to exit with the specified signal, dumping core
2907 * if appropriate. We bypass the normal tests for masked and caught signals,
2908 * allowing unrecoverable failures to terminate the process without changing
2909 * signal state. Mark the accounting record with the signal termination.
2910 * If dumping core, save the signal number for the debugger. Calls exit and
2911 * does not return.
2912 */
2913 void
2914 sigexit(td, sig)
2915 struct thread *td;
2916 int sig;
2917 {
2918 struct proc *p = td->td_proc;
2919
2920 PROC_LOCK_ASSERT(p, MA_OWNED);
2921 p->p_acflag |= AXSIG;
2922 /*
2923 * We must be single-threading to generate a core dump. This
2924 * ensures that the registers in the core file are up-to-date.
2925 * Also, the ELF dump handler assumes that the thread list doesn't
2926 * change out from under it.
2927 *
2928 * XXX If another thread attempts to single-thread before us
2929 * (e.g. via fork()), we won't get a dump at all.
2930 */
2931 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) {
2932 p->p_sig = sig;
2933 /*
2934 * Log signals which would cause core dumps
2935 * (Log as LOG_INFO to appease those who don't want
2936 * these messages.)
2937 * XXX : Todo, as well as euid, write out ruid too
2938 * Note that coredump() drops proc lock.
2939 */
2940 if (coredump(td) == 0)
2941 sig |= WCOREFLAG;
2942 if (kern_logsigexit)
2943 log(LOG_INFO,
2944 "pid %d (%s), uid %d: exited on signal %d%s\n",
2945 p->p_pid, p->p_comm,
2946 td->td_ucred ? td->td_ucred->cr_uid : -1,
2947 sig &~ WCOREFLAG,
2948 sig & WCOREFLAG ? " (core dumped)" : "");
2949 } else
2950 PROC_UNLOCK(p);
2951 exit1(td, W_EXITCODE(0, sig));
2952 /* NOTREACHED */
2953 }
2954
2955 /*
2956 * Send queued SIGCHLD to parent when child process's state
2957 * is changed.
2958 */
2959 static void
2960 sigparent(struct proc *p, int reason, int status)
2961 {
2962 PROC_LOCK_ASSERT(p, MA_OWNED);
2963 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
2964
2965 if (p->p_ksi != NULL) {
2966 p->p_ksi->ksi_signo = SIGCHLD;
2967 p->p_ksi->ksi_code = reason;
2968 p->p_ksi->ksi_status = status;
2969 p->p_ksi->ksi_pid = p->p_pid;
2970 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid;
2971 if (KSI_ONQ(p->p_ksi))
2972 return;
2973 }
2974 pksignal(p->p_pptr, SIGCHLD, p->p_ksi);
2975 }
2976
2977 static void
2978 childproc_jobstate(struct proc *p, int reason, int sig)
2979 {
2980 struct sigacts *ps;
2981
2982 PROC_LOCK_ASSERT(p, MA_OWNED);
2983 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
2984
2985 /*
2986 * Wake up parent sleeping in kern_wait(), also send
2987 * SIGCHLD to parent, but SIGCHLD does not guarantee
2988 * that parent will awake, because parent may masked
2989 * the signal.
2990 */
2991 p->p_pptr->p_flag |= P_STATCHILD;
2992 wakeup(p->p_pptr);
2993
2994 ps = p->p_pptr->p_sigacts;
2995 mtx_lock(&ps->ps_mtx);
2996 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) {
2997 mtx_unlock(&ps->ps_mtx);
2998 sigparent(p, reason, sig);
2999 } else
3000 mtx_unlock(&ps->ps_mtx);
3001 }
3002
3003 void
3004 childproc_stopped(struct proc *p, int reason)
3005 {
3006 /* p_xstat is a plain signal number, not a full wait() status here. */
3007 childproc_jobstate(p, reason, p->p_xstat);
3008 }
3009
3010 void
3011 childproc_continued(struct proc *p)
3012 {
3013 childproc_jobstate(p, CLD_CONTINUED, SIGCONT);
3014 }
3015
3016 void
3017 childproc_exited(struct proc *p)
3018 {
3019 int reason;
3020 int xstat = p->p_xstat; /* convert to int */
3021 int status;
3022
3023 if (WCOREDUMP(xstat))
3024 reason = CLD_DUMPED, status = WTERMSIG(xstat);
3025 else if (WIFSIGNALED(xstat))
3026 reason = CLD_KILLED, status = WTERMSIG(xstat);
3027 else
3028 reason = CLD_EXITED, status = WEXITSTATUS(xstat);
3029 /*
3030 * XXX avoid calling wakeup(p->p_pptr), the work is
3031 * done in exit1().
3032 */
3033 sigparent(p, reason, status);
3034 }
3035
3036 /*
3037 * We only have 1 character for the core count in the format
3038 * string, so the range will be 0-9
3039 */
3040 #define MAX_NUM_CORES 10
3041 static int num_cores = 5;
3042
3043 static int
3044 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS)
3045 {
3046 int error;
3047 int new_val;
3048
3049 new_val = num_cores;
3050 error = sysctl_handle_int(oidp, &new_val, 0, req);
3051 if (error != 0 || req->newptr == NULL)
3052 return (error);
3053 if (new_val > MAX_NUM_CORES)
3054 new_val = MAX_NUM_CORES;
3055 if (new_val < 0)
3056 new_val = 0;
3057 num_cores = new_val;
3058 return (0);
3059 }
3060 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW,
3061 0, sizeof(int), sysctl_debug_num_cores_check, "I", "");
3062
3063 #if defined(COMPRESS_USER_CORES)
3064 int compress_user_cores = 1;
3065 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RW,
3066 &compress_user_cores, 0, "Compression of user corefiles");
3067
3068 int compress_user_cores_gzlevel = -1; /* default level */
3069 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RW,
3070 &compress_user_cores_gzlevel, -1, "Corefile gzip compression level");
3071
3072 #define GZ_SUFFIX ".gz"
3073 #define GZ_SUFFIX_LEN 3
3074 #endif
3075
3076 static char corefilename[MAXPATHLEN] = {"%N.core"};
3077 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename));
3078 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
3079 sizeof(corefilename), "Process corefile name format string");
3080
3081 /*
3082 * corefile_open(comm, uid, pid, td, compress, vpp, namep)
3083 * Expand the name described in corefilename, using name, uid, and pid
3084 * and open/create core file.
3085 * corefilename is a printf-like string, with three format specifiers:
3086 * %N name of process ("name")
3087 * %P process id (pid)
3088 * %U user id (uid)
3089 * For example, "%N.core" is the default; they can be disabled completely
3090 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
3091 * This is controlled by the sysctl variable kern.corefile (see above).
3092 */
3093 static int
3094 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td,
3095 int compress, struct vnode **vpp, char **namep)
3096 {
3097 struct nameidata nd;
3098 struct sbuf sb;
3099 const char *format;
3100 char *hostname, *name;
3101 int indexpos, i, error, cmode, flags, oflags;
3102
3103 hostname = NULL;
3104 format = corefilename;
3105 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO);
3106 indexpos = -1;
3107 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN);
3108 for (i = 0; format[i] != '\0'; i++) {
3109 switch (format[i]) {
3110 case '%': /* Format character */
3111 i++;
3112 switch (format[i]) {
3113 case '%':
3114 sbuf_putc(&sb, '%');
3115 break;
3116 case 'H': /* hostname */
3117 if (hostname == NULL) {
3118 hostname = malloc(MAXHOSTNAMELEN,
3119 M_TEMP, M_WAITOK);
3120 }
3121 getcredhostname(td->td_ucred, hostname,
3122 MAXHOSTNAMELEN);
3123 sbuf_printf(&sb, "%s", hostname);
3124 break;
3125 case 'I': /* autoincrementing index */
3126 sbuf_printf(&sb, "");
3127 indexpos = sbuf_len(&sb) - 1;
3128 break;
3129 case 'N': /* process name */
3130 sbuf_printf(&sb, "%s", comm);
3131 break;
3132 case 'P': /* process id */
3133 sbuf_printf(&sb, "%u", pid);
3134 break;
3135 case 'U': /* user id */
3136 sbuf_printf(&sb, "%u", uid);
3137 break;
3138 default:
3139 log(LOG_ERR,
3140 "Unknown format character %c in "
3141 "corename `%s'\n", format[i], format);
3142 break;
3143 }
3144 break;
3145 default:
3146 sbuf_putc(&sb, format[i]);
3147 break;
3148 }
3149 }
3150 free(hostname, M_TEMP);
3151 #ifdef COMPRESS_USER_CORES
3152 if (compress)
3153 sbuf_printf(&sb, GZ_SUFFIX);
3154 #endif
3155 if (sbuf_error(&sb) != 0) {
3156 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too "
3157 "long\n", (long)pid, comm, (u_long)uid);
3158 sbuf_delete(&sb);
3159 free(name, M_TEMP);
3160 return (ENOMEM);
3161 }
3162 sbuf_finish(&sb);
3163 sbuf_delete(&sb);
3164
3165 cmode = S_IRUSR | S_IWUSR;
3166 oflags = VN_OPEN_NOAUDIT | (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0);
3167
3168 /*
3169 * If the core format has a %I in it, then we need to check
3170 * for existing corefiles before returning a name.
3171 * To do this we iterate over 0..num_cores to find a
3172 * non-existing core file name to use.
3173 */
3174 if (indexpos != -1) {
3175 for (i = 0; i < num_cores; i++) {
3176 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW;
3177 name[indexpos] = '' + i;
3178 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td);
3179 error = vn_open_cred(&nd, &flags, cmode, oflags,
3180 td->td_ucred, NULL);
3181 if (error) {
3182 if (error == EEXIST)
3183 continue;
3184 log(LOG_ERR,
3185 "pid %d (%s), uid (%u): Path `%s' failed "
3186 "on initial open test, error = %d\n",
3187 pid, comm, uid, name, error);
3188 }
3189 goto out;
3190 }
3191 }
3192
3193 flags = O_CREAT | FWRITE | O_NOFOLLOW;
3194 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td);
3195 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL);
3196 out:
3197 if (error) {
3198 #ifdef AUDIT
3199 audit_proc_coredump(td, name, error);
3200 #endif
3201 free(name, M_TEMP);
3202 return (error);
3203 }
3204 NDFREE(&nd, NDF_ONLY_PNBUF);
3205 *vpp = nd.ni_vp;
3206 *namep = name;
3207 return (0);
3208 }
3209
3210 /*
3211 * Dump a process' core. The main routine does some
3212 * policy checking, and creates the name of the coredump;
3213 * then it passes on a vnode and a size limit to the process-specific
3214 * coredump routine if there is one; if there _is not_ one, it returns
3215 * ENOSYS; otherwise it returns the error from the process-specific routine.
3216 */
3217
3218 static int
3219 coredump(struct thread *td)
3220 {
3221 struct proc *p = td->td_proc;
3222 struct ucred *cred = td->td_ucred;
3223 struct vnode *vp;
3224 struct flock lf;
3225 struct vattr vattr;
3226 int error, error1, locked;
3227 struct mount *mp;
3228 char *name; /* name of corefile */
3229 off_t limit;
3230 int compress;
3231
3232 #ifdef COMPRESS_USER_CORES
3233 compress = compress_user_cores;
3234 #else
3235 compress = 0;
3236 #endif
3237 PROC_LOCK_ASSERT(p, MA_OWNED);
3238 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td);
3239 _STOPEVENT(p, S_CORE, 0);
3240
3241 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0)) {
3242 PROC_UNLOCK(p);
3243 return (EFAULT);
3244 }
3245
3246 /*
3247 * Note that the bulk of limit checking is done after
3248 * the corefile is created. The exception is if the limit
3249 * for corefiles is 0, in which case we don't bother
3250 * creating the corefile at all. This layout means that
3251 * a corefile is truncated instead of not being created,
3252 * if it is larger than the limit.
3253 */
3254 limit = (off_t)lim_cur(p, RLIMIT_CORE);
3255 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) {
3256 PROC_UNLOCK(p);
3257 return (EFBIG);
3258 }
3259 PROC_UNLOCK(p);
3260
3261 restart:
3262 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, compress,
3263 &vp, &name);
3264 if (error != 0)
3265 return (error);
3266
3267 /* Don't dump to non-regular files or files with links. */
3268 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 ||
3269 vattr.va_nlink != 1) {
3270 VOP_UNLOCK(vp, 0);
3271 error = EFAULT;
3272 goto close;
3273 }
3274
3275 VOP_UNLOCK(vp, 0);
3276 lf.l_whence = SEEK_SET;
3277 lf.l_start = 0;
3278 lf.l_len = 0;
3279 lf.l_type = F_WRLCK;
3280 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0);
3281
3282 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
3283 lf.l_type = F_UNLCK;
3284 if (locked)
3285 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
3286 if ((error = vn_close(vp, FWRITE, cred, td)) != 0)
3287 goto out;
3288 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
3289 goto out;
3290 free(name, M_TEMP);
3291 goto restart;
3292 }
3293
3294 VATTR_NULL(&vattr);
3295 vattr.va_size = 0;
3296 if (set_core_nodump_flag)
3297 vattr.va_flags = UF_NODUMP;
3298 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3299 VOP_SETATTR(vp, &vattr, cred);
3300 VOP_UNLOCK(vp, 0);
3301 vn_finished_write(mp);
3302 PROC_LOCK(p);
3303 p->p_acflag |= ACORE;
3304 PROC_UNLOCK(p);
3305
3306 if (p->p_sysent->sv_coredump != NULL) {
3307 error = p->p_sysent->sv_coredump(td, vp, limit,
3308 compress ? IMGACT_CORE_COMPRESS : 0);
3309 } else {
3310 error = ENOSYS;
3311 }
3312
3313 if (locked) {
3314 lf.l_type = F_UNLCK;
3315 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
3316 }
3317 close:
3318 error1 = vn_close(vp, FWRITE, cred, td);
3319 if (error == 0)
3320 error = error1;
3321 out:
3322 #ifdef AUDIT
3323 audit_proc_coredump(td, name, error);
3324 #endif
3325 free(name, M_TEMP);
3326 return (error);
3327 }
3328
3329 /*
3330 * Nonexistent system call-- signal process (may want to handle it). Flag
3331 * error in case process won't see signal immediately (blocked or ignored).
3332 */
3333 #ifndef _SYS_SYSPROTO_H_
3334 struct nosys_args {
3335 int dummy;
3336 };
3337 #endif
3338 /* ARGSUSED */
3339 int
3340 nosys(td, args)
3341 struct thread *td;
3342 struct nosys_args *args;
3343 {
3344 struct proc *p = td->td_proc;
3345
3346 PROC_LOCK(p);
3347 tdsignal(td, SIGSYS);
3348 PROC_UNLOCK(p);
3349 return (ENOSYS);
3350 }
3351
3352 /*
3353 * Send a SIGIO or SIGURG signal to a process or process group using stored
3354 * credentials rather than those of the current process.
3355 */
3356 void
3357 pgsigio(sigiop, sig, checkctty)
3358 struct sigio **sigiop;
3359 int sig, checkctty;
3360 {
3361 ksiginfo_t ksi;
3362 struct sigio *sigio;
3363
3364 ksiginfo_init(&ksi);
3365 ksi.ksi_signo = sig;
3366 ksi.ksi_code = SI_KERNEL;
3367
3368 SIGIO_LOCK();
3369 sigio = *sigiop;
3370 if (sigio == NULL) {
3371 SIGIO_UNLOCK();
3372 return;
3373 }
3374 if (sigio->sio_pgid > 0) {
3375 PROC_LOCK(sigio->sio_proc);
3376 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred))
3377 kern_psignal(sigio->sio_proc, sig);
3378 PROC_UNLOCK(sigio->sio_proc);
3379 } else if (sigio->sio_pgid < 0) {
3380 struct proc *p;
3381
3382 PGRP_LOCK(sigio->sio_pgrp);
3383 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
3384 PROC_LOCK(p);
3385 if (p->p_state == PRS_NORMAL &&
3386 CANSIGIO(sigio->sio_ucred, p->p_ucred) &&
3387 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
3388 kern_psignal(p, sig);
3389 PROC_UNLOCK(p);
3390 }
3391 PGRP_UNLOCK(sigio->sio_pgrp);
3392 }
3393 SIGIO_UNLOCK();
3394 }
3395
3396 static int
3397 filt_sigattach(struct knote *kn)
3398 {
3399 struct proc *p = curproc;
3400
3401 kn->kn_ptr.p_proc = p;
3402 kn->kn_flags |= EV_CLEAR; /* automatically set */
3403
3404 knlist_add(&p->p_klist, kn, 0);
3405
3406 return (0);
3407 }
3408
3409 static void
3410 filt_sigdetach(struct knote *kn)
3411 {
3412 struct proc *p = kn->kn_ptr.p_proc;
3413
3414 knlist_remove(&p->p_klist, kn, 0);
3415 }
3416
3417 /*
3418 * signal knotes are shared with proc knotes, so we apply a mask to
3419 * the hint in order to differentiate them from process hints. This
3420 * could be avoided by using a signal-specific knote list, but probably
3421 * isn't worth the trouble.
3422 */
3423 static int
3424 filt_signal(struct knote *kn, long hint)
3425 {
3426
3427 if (hint & NOTE_SIGNAL) {
3428 hint &= ~NOTE_SIGNAL;
3429
3430 if (kn->kn_id == hint)
3431 kn->kn_data++;
3432 }
3433 return (kn->kn_data != 0);
3434 }
3435
3436 struct sigacts *
3437 sigacts_alloc(void)
3438 {
3439 struct sigacts *ps;
3440
3441 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO);
3442 ps->ps_refcnt = 1;
3443 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF);
3444 return (ps);
3445 }
3446
3447 void
3448 sigacts_free(struct sigacts *ps)
3449 {
3450
3451 if (refcount_release(&ps->ps_refcnt) == 0)
3452 return;
3453 mtx_destroy(&ps->ps_mtx);
3454 free(ps, M_SUBPROC);
3455 }
3456
3457 struct sigacts *
3458 sigacts_hold(struct sigacts *ps)
3459 {
3460
3461 refcount_acquire(&ps->ps_refcnt);
3462 return (ps);
3463 }
3464
3465 void
3466 sigacts_copy(struct sigacts *dest, struct sigacts *src)
3467 {
3468
3469 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest"));
3470 mtx_lock(&src->ps_mtx);
3471 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt));
3472 mtx_unlock(&src->ps_mtx);
3473 }
3474
3475 int
3476 sigacts_shared(struct sigacts *ps)
3477 {
3478
3479 return (ps->ps_refcnt > 1);
3480 }
Cache object: 5363f5dca93f8949b35eab3f48535fe2
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