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/11.0/sys/kern/kern_sig.c 302328 2016-07-03 18:19:48Z kib $");
39
40 #include "opt_compat.h"
41 #include "opt_gzio.h"
42 #include "opt_ktrace.h"
43
44 #include <sys/param.h>
45 #include <sys/ctype.h>
46 #include <sys/systm.h>
47 #include <sys/signalvar.h>
48 #include <sys/vnode.h>
49 #include <sys/acct.h>
50 #include <sys/bus.h>
51 #include <sys/capsicum.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, , , signal__send,
98 "struct thread *", "struct proc *", "int");
99 SDT_PROBE_DEFINE2(proc, , , signal__clear,
100 "int", "ksiginfo_t *");
101 SDT_PROBE_DEFINE3(proc, , , 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 int 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 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN,
143 &preallocate_siginfo, 0, "Preallocated signal memory size");
144
145 static int signal_overflow = 0;
146 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD,
147 &signal_overflow, 0, "Number of signals overflew");
148
149 static int signal_alloc_fail = 0;
150 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD,
151 &signal_alloc_fail, 0, "signals failed to be allocated");
152
153 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL);
154
155 /*
156 * Policy -- Can ucred cr1 send SIGIO to process cr2?
157 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG
158 * in the right situations.
159 */
160 #define CANSIGIO(cr1, cr2) \
161 ((cr1)->cr_uid == 0 || \
162 (cr1)->cr_ruid == (cr2)->cr_ruid || \
163 (cr1)->cr_uid == (cr2)->cr_ruid || \
164 (cr1)->cr_ruid == (cr2)->cr_uid || \
165 (cr1)->cr_uid == (cr2)->cr_uid)
166
167 static int sugid_coredump;
168 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN,
169 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core");
170
171 static int capmode_coredump;
172 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN,
173 &capmode_coredump, 0, "Allow processes in capability mode to dump core");
174
175 static int do_coredump = 1;
176 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
177 &do_coredump, 0, "Enable/Disable coredumps");
178
179 static int set_core_nodump_flag = 0;
180 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag,
181 0, "Enable setting the NODUMP flag on coredump files");
182
183 static int coredump_devctl = 0;
184 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl,
185 0, "Generate a devctl notification when processes coredump");
186
187 /*
188 * Signal properties and actions.
189 * The array below categorizes the signals and their default actions
190 * according to the following properties:
191 */
192 #define SA_KILL 0x01 /* terminates process by default */
193 #define SA_CORE 0x02 /* ditto and coredumps */
194 #define SA_STOP 0x04 /* suspend process */
195 #define SA_TTYSTOP 0x08 /* ditto, from tty */
196 #define SA_IGNORE 0x10 /* ignore by default */
197 #define SA_CONT 0x20 /* continue if suspended */
198 #define SA_CANTMASK 0x40 /* non-maskable, catchable */
199
200 static int sigproptbl[NSIG] = {
201 SA_KILL, /* SIGHUP */
202 SA_KILL, /* SIGINT */
203 SA_KILL|SA_CORE, /* SIGQUIT */
204 SA_KILL|SA_CORE, /* SIGILL */
205 SA_KILL|SA_CORE, /* SIGTRAP */
206 SA_KILL|SA_CORE, /* SIGABRT */
207 SA_KILL|SA_CORE, /* SIGEMT */
208 SA_KILL|SA_CORE, /* SIGFPE */
209 SA_KILL, /* SIGKILL */
210 SA_KILL|SA_CORE, /* SIGBUS */
211 SA_KILL|SA_CORE, /* SIGSEGV */
212 SA_KILL|SA_CORE, /* SIGSYS */
213 SA_KILL, /* SIGPIPE */
214 SA_KILL, /* SIGALRM */
215 SA_KILL, /* SIGTERM */
216 SA_IGNORE, /* SIGURG */
217 SA_STOP, /* SIGSTOP */
218 SA_STOP|SA_TTYSTOP, /* SIGTSTP */
219 SA_IGNORE|SA_CONT, /* SIGCONT */
220 SA_IGNORE, /* SIGCHLD */
221 SA_STOP|SA_TTYSTOP, /* SIGTTIN */
222 SA_STOP|SA_TTYSTOP, /* SIGTTOU */
223 SA_IGNORE, /* SIGIO */
224 SA_KILL, /* SIGXCPU */
225 SA_KILL, /* SIGXFSZ */
226 SA_KILL, /* SIGVTALRM */
227 SA_KILL, /* SIGPROF */
228 SA_IGNORE, /* SIGWINCH */
229 SA_IGNORE, /* SIGINFO */
230 SA_KILL, /* SIGUSR1 */
231 SA_KILL, /* SIGUSR2 */
232 };
233
234 static void reschedule_signals(struct proc *p, sigset_t block, int flags);
235
236 static void
237 sigqueue_start(void)
238 {
239 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t),
240 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
241 uma_prealloc(ksiginfo_zone, preallocate_siginfo);
242 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS);
243 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1);
244 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc);
245 }
246
247 ksiginfo_t *
248 ksiginfo_alloc(int wait)
249 {
250 int flags;
251
252 flags = M_ZERO;
253 if (! wait)
254 flags |= M_NOWAIT;
255 if (ksiginfo_zone != NULL)
256 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags));
257 return (NULL);
258 }
259
260 void
261 ksiginfo_free(ksiginfo_t *ksi)
262 {
263 uma_zfree(ksiginfo_zone, ksi);
264 }
265
266 static __inline int
267 ksiginfo_tryfree(ksiginfo_t *ksi)
268 {
269 if (!(ksi->ksi_flags & KSI_EXT)) {
270 uma_zfree(ksiginfo_zone, ksi);
271 return (1);
272 }
273 return (0);
274 }
275
276 void
277 sigqueue_init(sigqueue_t *list, struct proc *p)
278 {
279 SIGEMPTYSET(list->sq_signals);
280 SIGEMPTYSET(list->sq_kill);
281 TAILQ_INIT(&list->sq_list);
282 list->sq_proc = p;
283 list->sq_flags = SQ_INIT;
284 }
285
286 /*
287 * Get a signal's ksiginfo.
288 * Return:
289 * 0 - signal not found
290 * others - signal number
291 */
292 static int
293 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si)
294 {
295 struct proc *p = sq->sq_proc;
296 struct ksiginfo *ksi, *next;
297 int count = 0;
298
299 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
300
301 if (!SIGISMEMBER(sq->sq_signals, signo))
302 return (0);
303
304 if (SIGISMEMBER(sq->sq_kill, signo)) {
305 count++;
306 SIGDELSET(sq->sq_kill, signo);
307 }
308
309 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
310 if (ksi->ksi_signo == signo) {
311 if (count == 0) {
312 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
313 ksi->ksi_sigq = NULL;
314 ksiginfo_copy(ksi, si);
315 if (ksiginfo_tryfree(ksi) && p != NULL)
316 p->p_pendingcnt--;
317 }
318 if (++count > 1)
319 break;
320 }
321 }
322
323 if (count <= 1)
324 SIGDELSET(sq->sq_signals, signo);
325 si->ksi_signo = signo;
326 return (signo);
327 }
328
329 void
330 sigqueue_take(ksiginfo_t *ksi)
331 {
332 struct ksiginfo *kp;
333 struct proc *p;
334 sigqueue_t *sq;
335
336 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL)
337 return;
338
339 p = sq->sq_proc;
340 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
341 ksi->ksi_sigq = NULL;
342 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL)
343 p->p_pendingcnt--;
344
345 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL;
346 kp = TAILQ_NEXT(kp, ksi_link)) {
347 if (kp->ksi_signo == ksi->ksi_signo)
348 break;
349 }
350 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo))
351 SIGDELSET(sq->sq_signals, ksi->ksi_signo);
352 }
353
354 static int
355 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si)
356 {
357 struct proc *p = sq->sq_proc;
358 struct ksiginfo *ksi;
359 int ret = 0;
360
361 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
362
363 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) {
364 SIGADDSET(sq->sq_kill, signo);
365 goto out_set_bit;
366 }
367
368 /* directly insert the ksi, don't copy it */
369 if (si->ksi_flags & KSI_INS) {
370 if (si->ksi_flags & KSI_HEAD)
371 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link);
372 else
373 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link);
374 si->ksi_sigq = sq;
375 goto out_set_bit;
376 }
377
378 if (__predict_false(ksiginfo_zone == NULL)) {
379 SIGADDSET(sq->sq_kill, signo);
380 goto out_set_bit;
381 }
382
383 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) {
384 signal_overflow++;
385 ret = EAGAIN;
386 } else if ((ksi = ksiginfo_alloc(0)) == NULL) {
387 signal_alloc_fail++;
388 ret = EAGAIN;
389 } else {
390 if (p != NULL)
391 p->p_pendingcnt++;
392 ksiginfo_copy(si, ksi);
393 ksi->ksi_signo = signo;
394 if (si->ksi_flags & KSI_HEAD)
395 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link);
396 else
397 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link);
398 ksi->ksi_sigq = sq;
399 }
400
401 if ((si->ksi_flags & KSI_TRAP) != 0 ||
402 (si->ksi_flags & KSI_SIGQ) == 0) {
403 if (ret != 0)
404 SIGADDSET(sq->sq_kill, signo);
405 ret = 0;
406 goto out_set_bit;
407 }
408
409 if (ret != 0)
410 return (ret);
411
412 out_set_bit:
413 SIGADDSET(sq->sq_signals, signo);
414 return (ret);
415 }
416
417 void
418 sigqueue_flush(sigqueue_t *sq)
419 {
420 struct proc *p = sq->sq_proc;
421 ksiginfo_t *ksi;
422
423 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
424
425 if (p != NULL)
426 PROC_LOCK_ASSERT(p, MA_OWNED);
427
428 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) {
429 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
430 ksi->ksi_sigq = NULL;
431 if (ksiginfo_tryfree(ksi) && p != NULL)
432 p->p_pendingcnt--;
433 }
434
435 SIGEMPTYSET(sq->sq_signals);
436 SIGEMPTYSET(sq->sq_kill);
437 }
438
439 static void
440 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set)
441 {
442 sigset_t tmp;
443 struct proc *p1, *p2;
444 ksiginfo_t *ksi, *next;
445
446 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited"));
447 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited"));
448 p1 = src->sq_proc;
449 p2 = dst->sq_proc;
450 /* Move siginfo to target list */
451 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) {
452 if (SIGISMEMBER(*set, ksi->ksi_signo)) {
453 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link);
454 if (p1 != NULL)
455 p1->p_pendingcnt--;
456 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link);
457 ksi->ksi_sigq = dst;
458 if (p2 != NULL)
459 p2->p_pendingcnt++;
460 }
461 }
462
463 /* Move pending bits to target list */
464 tmp = src->sq_kill;
465 SIGSETAND(tmp, *set);
466 SIGSETOR(dst->sq_kill, tmp);
467 SIGSETNAND(src->sq_kill, tmp);
468
469 tmp = src->sq_signals;
470 SIGSETAND(tmp, *set);
471 SIGSETOR(dst->sq_signals, tmp);
472 SIGSETNAND(src->sq_signals, tmp);
473 }
474
475 #if 0
476 static void
477 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo)
478 {
479 sigset_t set;
480
481 SIGEMPTYSET(set);
482 SIGADDSET(set, signo);
483 sigqueue_move_set(src, dst, &set);
484 }
485 #endif
486
487 static void
488 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set)
489 {
490 struct proc *p = sq->sq_proc;
491 ksiginfo_t *ksi, *next;
492
493 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited"));
494
495 /* Remove siginfo queue */
496 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
497 if (SIGISMEMBER(*set, ksi->ksi_signo)) {
498 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
499 ksi->ksi_sigq = NULL;
500 if (ksiginfo_tryfree(ksi) && p != NULL)
501 p->p_pendingcnt--;
502 }
503 }
504 SIGSETNAND(sq->sq_kill, *set);
505 SIGSETNAND(sq->sq_signals, *set);
506 }
507
508 void
509 sigqueue_delete(sigqueue_t *sq, int signo)
510 {
511 sigset_t set;
512
513 SIGEMPTYSET(set);
514 SIGADDSET(set, signo);
515 sigqueue_delete_set(sq, &set);
516 }
517
518 /* Remove a set of signals for a process */
519 static void
520 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set)
521 {
522 sigqueue_t worklist;
523 struct thread *td0;
524
525 PROC_LOCK_ASSERT(p, MA_OWNED);
526
527 sigqueue_init(&worklist, NULL);
528 sigqueue_move_set(&p->p_sigqueue, &worklist, set);
529
530 FOREACH_THREAD_IN_PROC(p, td0)
531 sigqueue_move_set(&td0->td_sigqueue, &worklist, set);
532
533 sigqueue_flush(&worklist);
534 }
535
536 void
537 sigqueue_delete_proc(struct proc *p, int signo)
538 {
539 sigset_t set;
540
541 SIGEMPTYSET(set);
542 SIGADDSET(set, signo);
543 sigqueue_delete_set_proc(p, &set);
544 }
545
546 static void
547 sigqueue_delete_stopmask_proc(struct proc *p)
548 {
549 sigset_t set;
550
551 SIGEMPTYSET(set);
552 SIGADDSET(set, SIGSTOP);
553 SIGADDSET(set, SIGTSTP);
554 SIGADDSET(set, SIGTTIN);
555 SIGADDSET(set, SIGTTOU);
556 sigqueue_delete_set_proc(p, &set);
557 }
558
559 /*
560 * Determine signal that should be delivered to thread td, the current
561 * thread, 0 if none. If there is a pending stop signal with default
562 * action, the process stops in issignal().
563 */
564 int
565 cursig(struct thread *td)
566 {
567 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
568 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED);
569 THREAD_LOCK_ASSERT(td, MA_NOTOWNED);
570 return (SIGPENDING(td) ? issignal(td) : 0);
571 }
572
573 /*
574 * Arrange for ast() to handle unmasked pending signals on return to user
575 * mode. This must be called whenever a signal is added to td_sigqueue or
576 * unmasked in td_sigmask.
577 */
578 void
579 signotify(struct thread *td)
580 {
581 struct proc *p;
582
583 p = td->td_proc;
584
585 PROC_LOCK_ASSERT(p, MA_OWNED);
586
587 if (SIGPENDING(td)) {
588 thread_lock(td);
589 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING;
590 thread_unlock(td);
591 }
592 }
593
594 int
595 sigonstack(size_t sp)
596 {
597 struct thread *td = curthread;
598
599 return ((td->td_pflags & TDP_ALTSTACK) ?
600 #if defined(COMPAT_43)
601 ((td->td_sigstk.ss_size == 0) ?
602 (td->td_sigstk.ss_flags & SS_ONSTACK) :
603 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size))
604 #else
605 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)
606 #endif
607 : 0);
608 }
609
610 static __inline int
611 sigprop(int sig)
612 {
613
614 if (sig > 0 && sig < NSIG)
615 return (sigproptbl[_SIG_IDX(sig)]);
616 return (0);
617 }
618
619 int
620 sig_ffs(sigset_t *set)
621 {
622 int i;
623
624 for (i = 0; i < _SIG_WORDS; i++)
625 if (set->__bits[i])
626 return (ffs(set->__bits[i]) + (i * 32));
627 return (0);
628 }
629
630 static bool
631 sigact_flag_test(const struct sigaction *act, int flag)
632 {
633
634 /*
635 * SA_SIGINFO is reset when signal disposition is set to
636 * ignore or default. Other flags are kept according to user
637 * settings.
638 */
639 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO ||
640 ((__sighandler_t *)act->sa_sigaction != SIG_IGN &&
641 (__sighandler_t *)act->sa_sigaction != SIG_DFL)));
642 }
643
644 /*
645 * kern_sigaction
646 * sigaction
647 * freebsd4_sigaction
648 * osigaction
649 */
650 int
651 kern_sigaction(struct thread *td, int sig, const struct sigaction *act,
652 struct sigaction *oact, int flags)
653 {
654 struct sigacts *ps;
655 struct proc *p = td->td_proc;
656
657 if (!_SIG_VALID(sig))
658 return (EINVAL);
659 if (act != NULL && act->sa_handler != SIG_DFL &&
660 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK |
661 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER |
662 SA_NOCLDWAIT | SA_SIGINFO)) != 0)
663 return (EINVAL);
664
665 PROC_LOCK(p);
666 ps = p->p_sigacts;
667 mtx_lock(&ps->ps_mtx);
668 if (oact) {
669 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
670 oact->sa_flags = 0;
671 if (SIGISMEMBER(ps->ps_sigonstack, sig))
672 oact->sa_flags |= SA_ONSTACK;
673 if (!SIGISMEMBER(ps->ps_sigintr, sig))
674 oact->sa_flags |= SA_RESTART;
675 if (SIGISMEMBER(ps->ps_sigreset, sig))
676 oact->sa_flags |= SA_RESETHAND;
677 if (SIGISMEMBER(ps->ps_signodefer, sig))
678 oact->sa_flags |= SA_NODEFER;
679 if (SIGISMEMBER(ps->ps_siginfo, sig)) {
680 oact->sa_flags |= SA_SIGINFO;
681 oact->sa_sigaction =
682 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)];
683 } else
684 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
685 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP)
686 oact->sa_flags |= SA_NOCLDSTOP;
687 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT)
688 oact->sa_flags |= SA_NOCLDWAIT;
689 }
690 if (act) {
691 if ((sig == SIGKILL || sig == SIGSTOP) &&
692 act->sa_handler != SIG_DFL) {
693 mtx_unlock(&ps->ps_mtx);
694 PROC_UNLOCK(p);
695 return (EINVAL);
696 }
697
698 /*
699 * Change setting atomically.
700 */
701
702 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
703 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
704 if (sigact_flag_test(act, SA_SIGINFO)) {
705 ps->ps_sigact[_SIG_IDX(sig)] =
706 (__sighandler_t *)act->sa_sigaction;
707 SIGADDSET(ps->ps_siginfo, sig);
708 } else {
709 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
710 SIGDELSET(ps->ps_siginfo, sig);
711 }
712 if (!sigact_flag_test(act, SA_RESTART))
713 SIGADDSET(ps->ps_sigintr, sig);
714 else
715 SIGDELSET(ps->ps_sigintr, sig);
716 if (sigact_flag_test(act, SA_ONSTACK))
717 SIGADDSET(ps->ps_sigonstack, sig);
718 else
719 SIGDELSET(ps->ps_sigonstack, sig);
720 if (sigact_flag_test(act, SA_RESETHAND))
721 SIGADDSET(ps->ps_sigreset, sig);
722 else
723 SIGDELSET(ps->ps_sigreset, sig);
724 if (sigact_flag_test(act, SA_NODEFER))
725 SIGADDSET(ps->ps_signodefer, sig);
726 else
727 SIGDELSET(ps->ps_signodefer, sig);
728 if (sig == SIGCHLD) {
729 if (act->sa_flags & SA_NOCLDSTOP)
730 ps->ps_flag |= PS_NOCLDSTOP;
731 else
732 ps->ps_flag &= ~PS_NOCLDSTOP;
733 if (act->sa_flags & SA_NOCLDWAIT) {
734 /*
735 * Paranoia: since SA_NOCLDWAIT is implemented
736 * by reparenting the dying child to PID 1 (and
737 * trust it to reap the zombie), PID 1 itself
738 * is forbidden to set SA_NOCLDWAIT.
739 */
740 if (p->p_pid == 1)
741 ps->ps_flag &= ~PS_NOCLDWAIT;
742 else
743 ps->ps_flag |= PS_NOCLDWAIT;
744 } else
745 ps->ps_flag &= ~PS_NOCLDWAIT;
746 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
747 ps->ps_flag |= PS_CLDSIGIGN;
748 else
749 ps->ps_flag &= ~PS_CLDSIGIGN;
750 }
751 /*
752 * Set bit in ps_sigignore for signals that are set to SIG_IGN,
753 * and for signals set to SIG_DFL where the default is to
754 * ignore. However, don't put SIGCONT in ps_sigignore, as we
755 * have to restart the process.
756 */
757 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
758 (sigprop(sig) & SA_IGNORE &&
759 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
760 /* never to be seen again */
761 sigqueue_delete_proc(p, sig);
762 if (sig != SIGCONT)
763 /* easier in psignal */
764 SIGADDSET(ps->ps_sigignore, sig);
765 SIGDELSET(ps->ps_sigcatch, sig);
766 } else {
767 SIGDELSET(ps->ps_sigignore, sig);
768 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
769 SIGDELSET(ps->ps_sigcatch, sig);
770 else
771 SIGADDSET(ps->ps_sigcatch, sig);
772 }
773 #ifdef COMPAT_FREEBSD4
774 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
775 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
776 (flags & KSA_FREEBSD4) == 0)
777 SIGDELSET(ps->ps_freebsd4, sig);
778 else
779 SIGADDSET(ps->ps_freebsd4, sig);
780 #endif
781 #ifdef COMPAT_43
782 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
783 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
784 (flags & KSA_OSIGSET) == 0)
785 SIGDELSET(ps->ps_osigset, sig);
786 else
787 SIGADDSET(ps->ps_osigset, sig);
788 #endif
789 }
790 mtx_unlock(&ps->ps_mtx);
791 PROC_UNLOCK(p);
792 return (0);
793 }
794
795 #ifndef _SYS_SYSPROTO_H_
796 struct sigaction_args {
797 int sig;
798 struct sigaction *act;
799 struct sigaction *oact;
800 };
801 #endif
802 int
803 sys_sigaction(td, uap)
804 struct thread *td;
805 register struct sigaction_args *uap;
806 {
807 struct sigaction act, oact;
808 register struct sigaction *actp, *oactp;
809 int error;
810
811 actp = (uap->act != NULL) ? &act : NULL;
812 oactp = (uap->oact != NULL) ? &oact : NULL;
813 if (actp) {
814 error = copyin(uap->act, actp, sizeof(act));
815 if (error)
816 return (error);
817 }
818 error = kern_sigaction(td, uap->sig, actp, oactp, 0);
819 if (oactp && !error)
820 error = copyout(oactp, uap->oact, sizeof(oact));
821 return (error);
822 }
823
824 #ifdef COMPAT_FREEBSD4
825 #ifndef _SYS_SYSPROTO_H_
826 struct freebsd4_sigaction_args {
827 int sig;
828 struct sigaction *act;
829 struct sigaction *oact;
830 };
831 #endif
832 int
833 freebsd4_sigaction(td, uap)
834 struct thread *td;
835 register struct freebsd4_sigaction_args *uap;
836 {
837 struct sigaction act, oact;
838 register struct sigaction *actp, *oactp;
839 int error;
840
841
842 actp = (uap->act != NULL) ? &act : NULL;
843 oactp = (uap->oact != NULL) ? &oact : NULL;
844 if (actp) {
845 error = copyin(uap->act, actp, sizeof(act));
846 if (error)
847 return (error);
848 }
849 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4);
850 if (oactp && !error)
851 error = copyout(oactp, uap->oact, sizeof(oact));
852 return (error);
853 }
854 #endif /* COMAPT_FREEBSD4 */
855
856 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
857 #ifndef _SYS_SYSPROTO_H_
858 struct osigaction_args {
859 int signum;
860 struct osigaction *nsa;
861 struct osigaction *osa;
862 };
863 #endif
864 int
865 osigaction(td, uap)
866 struct thread *td;
867 register struct osigaction_args *uap;
868 {
869 struct osigaction sa;
870 struct sigaction nsa, osa;
871 register struct sigaction *nsap, *osap;
872 int error;
873
874 if (uap->signum <= 0 || uap->signum >= ONSIG)
875 return (EINVAL);
876
877 nsap = (uap->nsa != NULL) ? &nsa : NULL;
878 osap = (uap->osa != NULL) ? &osa : NULL;
879
880 if (nsap) {
881 error = copyin(uap->nsa, &sa, sizeof(sa));
882 if (error)
883 return (error);
884 nsap->sa_handler = sa.sa_handler;
885 nsap->sa_flags = sa.sa_flags;
886 OSIG2SIG(sa.sa_mask, nsap->sa_mask);
887 }
888 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
889 if (osap && !error) {
890 sa.sa_handler = osap->sa_handler;
891 sa.sa_flags = osap->sa_flags;
892 SIG2OSIG(osap->sa_mask, sa.sa_mask);
893 error = copyout(&sa, uap->osa, sizeof(sa));
894 }
895 return (error);
896 }
897
898 #if !defined(__i386__)
899 /* Avoid replicating the same stub everywhere */
900 int
901 osigreturn(td, uap)
902 struct thread *td;
903 struct osigreturn_args *uap;
904 {
905
906 return (nosys(td, (struct nosys_args *)uap));
907 }
908 #endif
909 #endif /* COMPAT_43 */
910
911 /*
912 * Initialize signal state for process 0;
913 * set to ignore signals that are ignored by default.
914 */
915 void
916 siginit(p)
917 struct proc *p;
918 {
919 register int i;
920 struct sigacts *ps;
921
922 PROC_LOCK(p);
923 ps = p->p_sigacts;
924 mtx_lock(&ps->ps_mtx);
925 for (i = 1; i <= NSIG; i++) {
926 if (sigprop(i) & SA_IGNORE && i != SIGCONT) {
927 SIGADDSET(ps->ps_sigignore, i);
928 }
929 }
930 mtx_unlock(&ps->ps_mtx);
931 PROC_UNLOCK(p);
932 }
933
934 /*
935 * Reset specified signal to the default disposition.
936 */
937 static void
938 sigdflt(struct sigacts *ps, int sig)
939 {
940
941 mtx_assert(&ps->ps_mtx, MA_OWNED);
942 SIGDELSET(ps->ps_sigcatch, sig);
943 if ((sigprop(sig) & SA_IGNORE) != 0 && sig != SIGCONT)
944 SIGADDSET(ps->ps_sigignore, sig);
945 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
946 SIGDELSET(ps->ps_siginfo, sig);
947 }
948
949 /*
950 * Reset signals for an exec of the specified process.
951 */
952 void
953 execsigs(struct proc *p)
954 {
955 sigset_t osigignore;
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 /*
977 * As CloudABI processes cannot modify signal handlers, fully
978 * reset all signals to their default behavior. Do ignore
979 * SIGPIPE, as it would otherwise be impossible to recover from
980 * writes to broken pipes and sockets.
981 */
982 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) {
983 osigignore = ps->ps_sigignore;
984 while (SIGNOTEMPTY(osigignore)) {
985 sig = sig_ffs(&osigignore);
986 SIGDELSET(osigignore, sig);
987 if (sig != SIGPIPE)
988 sigdflt(ps, sig);
989 }
990 SIGADDSET(ps->ps_sigignore, SIGPIPE);
991 }
992
993 /*
994 * Reset stack state to the user stack.
995 * Clear set of signals caught on the signal stack.
996 */
997 td->td_sigstk.ss_flags = SS_DISABLE;
998 td->td_sigstk.ss_size = 0;
999 td->td_sigstk.ss_sp = 0;
1000 td->td_pflags &= ~TDP_ALTSTACK;
1001 /*
1002 * Reset no zombies if child dies flag as Solaris does.
1003 */
1004 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN);
1005 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
1006 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL;
1007 mtx_unlock(&ps->ps_mtx);
1008 }
1009
1010 /*
1011 * kern_sigprocmask()
1012 *
1013 * Manipulate signal mask.
1014 */
1015 int
1016 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset,
1017 int flags)
1018 {
1019 sigset_t new_block, oset1;
1020 struct proc *p;
1021 int error;
1022
1023 p = td->td_proc;
1024 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0)
1025 PROC_LOCK_ASSERT(p, MA_OWNED);
1026 else
1027 PROC_LOCK(p);
1028 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0
1029 ? MA_OWNED : MA_NOTOWNED);
1030 if (oset != NULL)
1031 *oset = td->td_sigmask;
1032
1033 error = 0;
1034 if (set != NULL) {
1035 switch (how) {
1036 case SIG_BLOCK:
1037 SIG_CANTMASK(*set);
1038 oset1 = td->td_sigmask;
1039 SIGSETOR(td->td_sigmask, *set);
1040 new_block = td->td_sigmask;
1041 SIGSETNAND(new_block, oset1);
1042 break;
1043 case SIG_UNBLOCK:
1044 SIGSETNAND(td->td_sigmask, *set);
1045 signotify(td);
1046 goto out;
1047 case SIG_SETMASK:
1048 SIG_CANTMASK(*set);
1049 oset1 = td->td_sigmask;
1050 if (flags & SIGPROCMASK_OLD)
1051 SIGSETLO(td->td_sigmask, *set);
1052 else
1053 td->td_sigmask = *set;
1054 new_block = td->td_sigmask;
1055 SIGSETNAND(new_block, oset1);
1056 signotify(td);
1057 break;
1058 default:
1059 error = EINVAL;
1060 goto out;
1061 }
1062
1063 /*
1064 * The new_block set contains signals that were not previously
1065 * blocked, but are blocked now.
1066 *
1067 * In case we block any signal that was not previously blocked
1068 * for td, and process has the signal pending, try to schedule
1069 * signal delivery to some thread that does not block the
1070 * signal, possibly waking it up.
1071 */
1072 if (p->p_numthreads != 1)
1073 reschedule_signals(p, new_block, flags);
1074 }
1075
1076 out:
1077 if (!(flags & SIGPROCMASK_PROC_LOCKED))
1078 PROC_UNLOCK(p);
1079 return (error);
1080 }
1081
1082 #ifndef _SYS_SYSPROTO_H_
1083 struct sigprocmask_args {
1084 int how;
1085 const sigset_t *set;
1086 sigset_t *oset;
1087 };
1088 #endif
1089 int
1090 sys_sigprocmask(td, uap)
1091 register struct thread *td;
1092 struct sigprocmask_args *uap;
1093 {
1094 sigset_t set, oset;
1095 sigset_t *setp, *osetp;
1096 int error;
1097
1098 setp = (uap->set != NULL) ? &set : NULL;
1099 osetp = (uap->oset != NULL) ? &oset : NULL;
1100 if (setp) {
1101 error = copyin(uap->set, setp, sizeof(set));
1102 if (error)
1103 return (error);
1104 }
1105 error = kern_sigprocmask(td, uap->how, setp, osetp, 0);
1106 if (osetp && !error) {
1107 error = copyout(osetp, uap->oset, sizeof(oset));
1108 }
1109 return (error);
1110 }
1111
1112 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1113 #ifndef _SYS_SYSPROTO_H_
1114 struct osigprocmask_args {
1115 int how;
1116 osigset_t mask;
1117 };
1118 #endif
1119 int
1120 osigprocmask(td, uap)
1121 register struct thread *td;
1122 struct osigprocmask_args *uap;
1123 {
1124 sigset_t set, oset;
1125 int error;
1126
1127 OSIG2SIG(uap->mask, set);
1128 error = kern_sigprocmask(td, uap->how, &set, &oset, 1);
1129 SIG2OSIG(oset, td->td_retval[0]);
1130 return (error);
1131 }
1132 #endif /* COMPAT_43 */
1133
1134 int
1135 sys_sigwait(struct thread *td, struct sigwait_args *uap)
1136 {
1137 ksiginfo_t ksi;
1138 sigset_t set;
1139 int error;
1140
1141 error = copyin(uap->set, &set, sizeof(set));
1142 if (error) {
1143 td->td_retval[0] = error;
1144 return (0);
1145 }
1146
1147 error = kern_sigtimedwait(td, set, &ksi, NULL);
1148 if (error) {
1149 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT)
1150 error = ERESTART;
1151 if (error == ERESTART)
1152 return (error);
1153 td->td_retval[0] = error;
1154 return (0);
1155 }
1156
1157 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo));
1158 td->td_retval[0] = error;
1159 return (0);
1160 }
1161
1162 int
1163 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap)
1164 {
1165 struct timespec ts;
1166 struct timespec *timeout;
1167 sigset_t set;
1168 ksiginfo_t ksi;
1169 int error;
1170
1171 if (uap->timeout) {
1172 error = copyin(uap->timeout, &ts, sizeof(ts));
1173 if (error)
1174 return (error);
1175
1176 timeout = &ts;
1177 } else
1178 timeout = NULL;
1179
1180 error = copyin(uap->set, &set, sizeof(set));
1181 if (error)
1182 return (error);
1183
1184 error = kern_sigtimedwait(td, set, &ksi, timeout);
1185 if (error)
1186 return (error);
1187
1188 if (uap->info)
1189 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t));
1190
1191 if (error == 0)
1192 td->td_retval[0] = ksi.ksi_signo;
1193 return (error);
1194 }
1195
1196 int
1197 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap)
1198 {
1199 ksiginfo_t ksi;
1200 sigset_t set;
1201 int error;
1202
1203 error = copyin(uap->set, &set, sizeof(set));
1204 if (error)
1205 return (error);
1206
1207 error = kern_sigtimedwait(td, set, &ksi, NULL);
1208 if (error)
1209 return (error);
1210
1211 if (uap->info)
1212 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t));
1213
1214 if (error == 0)
1215 td->td_retval[0] = ksi.ksi_signo;
1216 return (error);
1217 }
1218
1219 int
1220 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi,
1221 struct timespec *timeout)
1222 {
1223 struct sigacts *ps;
1224 sigset_t saved_mask, new_block;
1225 struct proc *p;
1226 int error, sig, timo, timevalid = 0;
1227 struct timespec rts, ets, ts;
1228 struct timeval tv;
1229
1230 p = td->td_proc;
1231 error = 0;
1232 ets.tv_sec = 0;
1233 ets.tv_nsec = 0;
1234
1235 if (timeout != NULL) {
1236 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) {
1237 timevalid = 1;
1238 getnanouptime(&rts);
1239 ets = rts;
1240 timespecadd(&ets, timeout);
1241 }
1242 }
1243 ksiginfo_init(ksi);
1244 /* Some signals can not be waited for. */
1245 SIG_CANTMASK(waitset);
1246 ps = p->p_sigacts;
1247 PROC_LOCK(p);
1248 saved_mask = td->td_sigmask;
1249 SIGSETNAND(td->td_sigmask, waitset);
1250 for (;;) {
1251 mtx_lock(&ps->ps_mtx);
1252 sig = cursig(td);
1253 mtx_unlock(&ps->ps_mtx);
1254 KASSERT(sig >= 0, ("sig %d", sig));
1255 if (sig != 0 && SIGISMEMBER(waitset, sig)) {
1256 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 ||
1257 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) {
1258 error = 0;
1259 break;
1260 }
1261 }
1262
1263 if (error != 0)
1264 break;
1265
1266 /*
1267 * POSIX says this must be checked after looking for pending
1268 * signals.
1269 */
1270 if (timeout != NULL) {
1271 if (!timevalid) {
1272 error = EINVAL;
1273 break;
1274 }
1275 getnanouptime(&rts);
1276 if (timespeccmp(&rts, &ets, >=)) {
1277 error = EAGAIN;
1278 break;
1279 }
1280 ts = ets;
1281 timespecsub(&ts, &rts);
1282 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1283 timo = tvtohz(&tv);
1284 } else {
1285 timo = 0;
1286 }
1287
1288 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo);
1289
1290 if (timeout != NULL) {
1291 if (error == ERESTART) {
1292 /* Timeout can not be restarted. */
1293 error = EINTR;
1294 } else if (error == EAGAIN) {
1295 /* We will calculate timeout by ourself. */
1296 error = 0;
1297 }
1298 }
1299 }
1300
1301 new_block = saved_mask;
1302 SIGSETNAND(new_block, td->td_sigmask);
1303 td->td_sigmask = saved_mask;
1304 /*
1305 * Fewer signals can be delivered to us, reschedule signal
1306 * notification.
1307 */
1308 if (p->p_numthreads != 1)
1309 reschedule_signals(p, new_block, 0);
1310
1311 if (error == 0) {
1312 SDT_PROBE2(proc, , , signal__clear, sig, ksi);
1313
1314 if (ksi->ksi_code == SI_TIMER)
1315 itimer_accept(p, ksi->ksi_timerid, ksi);
1316
1317 #ifdef KTRACE
1318 if (KTRPOINT(td, KTR_PSIG)) {
1319 sig_t action;
1320
1321 mtx_lock(&ps->ps_mtx);
1322 action = ps->ps_sigact[_SIG_IDX(sig)];
1323 mtx_unlock(&ps->ps_mtx);
1324 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code);
1325 }
1326 #endif
1327 if (sig == SIGKILL)
1328 sigexit(td, sig);
1329 }
1330 PROC_UNLOCK(p);
1331 return (error);
1332 }
1333
1334 #ifndef _SYS_SYSPROTO_H_
1335 struct sigpending_args {
1336 sigset_t *set;
1337 };
1338 #endif
1339 int
1340 sys_sigpending(td, uap)
1341 struct thread *td;
1342 struct sigpending_args *uap;
1343 {
1344 struct proc *p = td->td_proc;
1345 sigset_t pending;
1346
1347 PROC_LOCK(p);
1348 pending = p->p_sigqueue.sq_signals;
1349 SIGSETOR(pending, td->td_sigqueue.sq_signals);
1350 PROC_UNLOCK(p);
1351 return (copyout(&pending, uap->set, sizeof(sigset_t)));
1352 }
1353
1354 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1355 #ifndef _SYS_SYSPROTO_H_
1356 struct osigpending_args {
1357 int dummy;
1358 };
1359 #endif
1360 int
1361 osigpending(td, uap)
1362 struct thread *td;
1363 struct osigpending_args *uap;
1364 {
1365 struct proc *p = td->td_proc;
1366 sigset_t pending;
1367
1368 PROC_LOCK(p);
1369 pending = p->p_sigqueue.sq_signals;
1370 SIGSETOR(pending, td->td_sigqueue.sq_signals);
1371 PROC_UNLOCK(p);
1372 SIG2OSIG(pending, td->td_retval[0]);
1373 return (0);
1374 }
1375 #endif /* COMPAT_43 */
1376
1377 #if defined(COMPAT_43)
1378 /*
1379 * Generalized interface signal handler, 4.3-compatible.
1380 */
1381 #ifndef _SYS_SYSPROTO_H_
1382 struct osigvec_args {
1383 int signum;
1384 struct sigvec *nsv;
1385 struct sigvec *osv;
1386 };
1387 #endif
1388 /* ARGSUSED */
1389 int
1390 osigvec(td, uap)
1391 struct thread *td;
1392 register struct osigvec_args *uap;
1393 {
1394 struct sigvec vec;
1395 struct sigaction nsa, osa;
1396 register struct sigaction *nsap, *osap;
1397 int error;
1398
1399 if (uap->signum <= 0 || uap->signum >= ONSIG)
1400 return (EINVAL);
1401 nsap = (uap->nsv != NULL) ? &nsa : NULL;
1402 osap = (uap->osv != NULL) ? &osa : NULL;
1403 if (nsap) {
1404 error = copyin(uap->nsv, &vec, sizeof(vec));
1405 if (error)
1406 return (error);
1407 nsap->sa_handler = vec.sv_handler;
1408 OSIG2SIG(vec.sv_mask, nsap->sa_mask);
1409 nsap->sa_flags = vec.sv_flags;
1410 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */
1411 }
1412 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
1413 if (osap && !error) {
1414 vec.sv_handler = osap->sa_handler;
1415 SIG2OSIG(osap->sa_mask, vec.sv_mask);
1416 vec.sv_flags = osap->sa_flags;
1417 vec.sv_flags &= ~SA_NOCLDWAIT;
1418 vec.sv_flags ^= SA_RESTART;
1419 error = copyout(&vec, uap->osv, sizeof(vec));
1420 }
1421 return (error);
1422 }
1423
1424 #ifndef _SYS_SYSPROTO_H_
1425 struct osigblock_args {
1426 int mask;
1427 };
1428 #endif
1429 int
1430 osigblock(td, uap)
1431 register struct thread *td;
1432 struct osigblock_args *uap;
1433 {
1434 sigset_t set, oset;
1435
1436 OSIG2SIG(uap->mask, set);
1437 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0);
1438 SIG2OSIG(oset, td->td_retval[0]);
1439 return (0);
1440 }
1441
1442 #ifndef _SYS_SYSPROTO_H_
1443 struct osigsetmask_args {
1444 int mask;
1445 };
1446 #endif
1447 int
1448 osigsetmask(td, uap)
1449 struct thread *td;
1450 struct osigsetmask_args *uap;
1451 {
1452 sigset_t set, oset;
1453
1454 OSIG2SIG(uap->mask, set);
1455 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0);
1456 SIG2OSIG(oset, td->td_retval[0]);
1457 return (0);
1458 }
1459 #endif /* COMPAT_43 */
1460
1461 /*
1462 * Suspend calling thread until signal, providing mask to be set in the
1463 * meantime.
1464 */
1465 #ifndef _SYS_SYSPROTO_H_
1466 struct sigsuspend_args {
1467 const sigset_t *sigmask;
1468 };
1469 #endif
1470 /* ARGSUSED */
1471 int
1472 sys_sigsuspend(td, uap)
1473 struct thread *td;
1474 struct sigsuspend_args *uap;
1475 {
1476 sigset_t mask;
1477 int error;
1478
1479 error = copyin(uap->sigmask, &mask, sizeof(mask));
1480 if (error)
1481 return (error);
1482 return (kern_sigsuspend(td, mask));
1483 }
1484
1485 int
1486 kern_sigsuspend(struct thread *td, sigset_t mask)
1487 {
1488 struct proc *p = td->td_proc;
1489 int has_sig, sig;
1490
1491 /*
1492 * When returning from sigsuspend, we want
1493 * the old mask to be restored after the
1494 * signal handler has finished. Thus, we
1495 * save it here and mark the sigacts structure
1496 * to indicate this.
1497 */
1498 PROC_LOCK(p);
1499 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask,
1500 SIGPROCMASK_PROC_LOCKED);
1501 td->td_pflags |= TDP_OLDMASK;
1502
1503 /*
1504 * Process signals now. Otherwise, we can get spurious wakeup
1505 * due to signal entered process queue, but delivered to other
1506 * thread. But sigsuspend should return only on signal
1507 * delivery.
1508 */
1509 (p->p_sysent->sv_set_syscall_retval)(td, EINTR);
1510 for (has_sig = 0; !has_sig;) {
1511 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause",
1512 0) == 0)
1513 /* void */;
1514 thread_suspend_check(0);
1515 mtx_lock(&p->p_sigacts->ps_mtx);
1516 while ((sig = cursig(td)) != 0) {
1517 KASSERT(sig >= 0, ("sig %d", sig));
1518 has_sig += postsig(sig);
1519 }
1520 mtx_unlock(&p->p_sigacts->ps_mtx);
1521 }
1522 PROC_UNLOCK(p);
1523 td->td_errno = EINTR;
1524 td->td_pflags |= TDP_NERRNO;
1525 return (EJUSTRETURN);
1526 }
1527
1528 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1529 /*
1530 * Compatibility sigsuspend call for old binaries. Note nonstandard calling
1531 * convention: libc stub passes mask, not pointer, to save a copyin.
1532 */
1533 #ifndef _SYS_SYSPROTO_H_
1534 struct osigsuspend_args {
1535 osigset_t mask;
1536 };
1537 #endif
1538 /* ARGSUSED */
1539 int
1540 osigsuspend(td, uap)
1541 struct thread *td;
1542 struct osigsuspend_args *uap;
1543 {
1544 sigset_t mask;
1545
1546 OSIG2SIG(uap->mask, mask);
1547 return (kern_sigsuspend(td, mask));
1548 }
1549 #endif /* COMPAT_43 */
1550
1551 #if defined(COMPAT_43)
1552 #ifndef _SYS_SYSPROTO_H_
1553 struct osigstack_args {
1554 struct sigstack *nss;
1555 struct sigstack *oss;
1556 };
1557 #endif
1558 /* ARGSUSED */
1559 int
1560 osigstack(td, uap)
1561 struct thread *td;
1562 register struct osigstack_args *uap;
1563 {
1564 struct sigstack nss, oss;
1565 int error = 0;
1566
1567 if (uap->nss != NULL) {
1568 error = copyin(uap->nss, &nss, sizeof(nss));
1569 if (error)
1570 return (error);
1571 }
1572 oss.ss_sp = td->td_sigstk.ss_sp;
1573 oss.ss_onstack = sigonstack(cpu_getstack(td));
1574 if (uap->nss != NULL) {
1575 td->td_sigstk.ss_sp = nss.ss_sp;
1576 td->td_sigstk.ss_size = 0;
1577 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK;
1578 td->td_pflags |= TDP_ALTSTACK;
1579 }
1580 if (uap->oss != NULL)
1581 error = copyout(&oss, uap->oss, sizeof(oss));
1582
1583 return (error);
1584 }
1585 #endif /* COMPAT_43 */
1586
1587 #ifndef _SYS_SYSPROTO_H_
1588 struct sigaltstack_args {
1589 stack_t *ss;
1590 stack_t *oss;
1591 };
1592 #endif
1593 /* ARGSUSED */
1594 int
1595 sys_sigaltstack(td, uap)
1596 struct thread *td;
1597 register struct sigaltstack_args *uap;
1598 {
1599 stack_t ss, oss;
1600 int error;
1601
1602 if (uap->ss != NULL) {
1603 error = copyin(uap->ss, &ss, sizeof(ss));
1604 if (error)
1605 return (error);
1606 }
1607 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL,
1608 (uap->oss != NULL) ? &oss : NULL);
1609 if (error)
1610 return (error);
1611 if (uap->oss != NULL)
1612 error = copyout(&oss, uap->oss, sizeof(stack_t));
1613 return (error);
1614 }
1615
1616 int
1617 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss)
1618 {
1619 struct proc *p = td->td_proc;
1620 int oonstack;
1621
1622 oonstack = sigonstack(cpu_getstack(td));
1623
1624 if (oss != NULL) {
1625 *oss = td->td_sigstk;
1626 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK)
1627 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
1628 }
1629
1630 if (ss != NULL) {
1631 if (oonstack)
1632 return (EPERM);
1633 if ((ss->ss_flags & ~SS_DISABLE) != 0)
1634 return (EINVAL);
1635 if (!(ss->ss_flags & SS_DISABLE)) {
1636 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
1637 return (ENOMEM);
1638
1639 td->td_sigstk = *ss;
1640 td->td_pflags |= TDP_ALTSTACK;
1641 } else {
1642 td->td_pflags &= ~TDP_ALTSTACK;
1643 }
1644 }
1645 return (0);
1646 }
1647
1648 /*
1649 * Common code for kill process group/broadcast kill.
1650 * cp is calling process.
1651 */
1652 static int
1653 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi)
1654 {
1655 struct proc *p;
1656 struct pgrp *pgrp;
1657 int err;
1658 int ret;
1659
1660 ret = ESRCH;
1661 if (all) {
1662 /*
1663 * broadcast
1664 */
1665 sx_slock(&allproc_lock);
1666 FOREACH_PROC_IN_SYSTEM(p) {
1667 PROC_LOCK(p);
1668 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
1669 p == td->td_proc || p->p_state == PRS_NEW) {
1670 PROC_UNLOCK(p);
1671 continue;
1672 }
1673 err = p_cansignal(td, p, sig);
1674 if (err == 0) {
1675 if (sig)
1676 pksignal(p, sig, ksi);
1677 ret = err;
1678 }
1679 else if (ret == ESRCH)
1680 ret = err;
1681 PROC_UNLOCK(p);
1682 }
1683 sx_sunlock(&allproc_lock);
1684 } else {
1685 sx_slock(&proctree_lock);
1686 if (pgid == 0) {
1687 /*
1688 * zero pgid means send to my process group.
1689 */
1690 pgrp = td->td_proc->p_pgrp;
1691 PGRP_LOCK(pgrp);
1692 } else {
1693 pgrp = pgfind(pgid);
1694 if (pgrp == NULL) {
1695 sx_sunlock(&proctree_lock);
1696 return (ESRCH);
1697 }
1698 }
1699 sx_sunlock(&proctree_lock);
1700 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
1701 PROC_LOCK(p);
1702 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
1703 p->p_state == PRS_NEW) {
1704 PROC_UNLOCK(p);
1705 continue;
1706 }
1707 err = p_cansignal(td, p, sig);
1708 if (err == 0) {
1709 if (sig)
1710 pksignal(p, sig, ksi);
1711 ret = err;
1712 }
1713 else if (ret == ESRCH)
1714 ret = err;
1715 PROC_UNLOCK(p);
1716 }
1717 PGRP_UNLOCK(pgrp);
1718 }
1719 return (ret);
1720 }
1721
1722 #ifndef _SYS_SYSPROTO_H_
1723 struct kill_args {
1724 int pid;
1725 int signum;
1726 };
1727 #endif
1728 /* ARGSUSED */
1729 int
1730 sys_kill(struct thread *td, struct kill_args *uap)
1731 {
1732 ksiginfo_t ksi;
1733 struct proc *p;
1734 int error;
1735
1736 /*
1737 * A process in capability mode can send signals only to himself.
1738 * The main rationale behind this is that abort(3) is implemented as
1739 * kill(getpid(), SIGABRT).
1740 */
1741 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid)
1742 return (ECAPMODE);
1743
1744 AUDIT_ARG_SIGNUM(uap->signum);
1745 AUDIT_ARG_PID(uap->pid);
1746 if ((u_int)uap->signum > _SIG_MAXSIG)
1747 return (EINVAL);
1748
1749 ksiginfo_init(&ksi);
1750 ksi.ksi_signo = uap->signum;
1751 ksi.ksi_code = SI_USER;
1752 ksi.ksi_pid = td->td_proc->p_pid;
1753 ksi.ksi_uid = td->td_ucred->cr_ruid;
1754
1755 if (uap->pid > 0) {
1756 /* kill single process */
1757 if ((p = pfind(uap->pid)) == NULL) {
1758 if ((p = zpfind(uap->pid)) == NULL)
1759 return (ESRCH);
1760 }
1761 AUDIT_ARG_PROCESS(p);
1762 error = p_cansignal(td, p, uap->signum);
1763 if (error == 0 && uap->signum)
1764 pksignal(p, uap->signum, &ksi);
1765 PROC_UNLOCK(p);
1766 return (error);
1767 }
1768 switch (uap->pid) {
1769 case -1: /* broadcast signal */
1770 return (killpg1(td, uap->signum, 0, 1, &ksi));
1771 case 0: /* signal own process group */
1772 return (killpg1(td, uap->signum, 0, 0, &ksi));
1773 default: /* negative explicit process group */
1774 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi));
1775 }
1776 /* NOTREACHED */
1777 }
1778
1779 int
1780 sys_pdkill(td, uap)
1781 struct thread *td;
1782 struct pdkill_args *uap;
1783 {
1784 struct proc *p;
1785 cap_rights_t rights;
1786 int error;
1787
1788 AUDIT_ARG_SIGNUM(uap->signum);
1789 AUDIT_ARG_FD(uap->fd);
1790 if ((u_int)uap->signum > _SIG_MAXSIG)
1791 return (EINVAL);
1792
1793 error = procdesc_find(td, uap->fd,
1794 cap_rights_init(&rights, CAP_PDKILL), &p);
1795 if (error)
1796 return (error);
1797 AUDIT_ARG_PROCESS(p);
1798 error = p_cansignal(td, p, uap->signum);
1799 if (error == 0 && uap->signum)
1800 kern_psignal(p, uap->signum);
1801 PROC_UNLOCK(p);
1802 return (error);
1803 }
1804
1805 #if defined(COMPAT_43)
1806 #ifndef _SYS_SYSPROTO_H_
1807 struct okillpg_args {
1808 int pgid;
1809 int signum;
1810 };
1811 #endif
1812 /* ARGSUSED */
1813 int
1814 okillpg(struct thread *td, struct okillpg_args *uap)
1815 {
1816 ksiginfo_t ksi;
1817
1818 AUDIT_ARG_SIGNUM(uap->signum);
1819 AUDIT_ARG_PID(uap->pgid);
1820 if ((u_int)uap->signum > _SIG_MAXSIG)
1821 return (EINVAL);
1822
1823 ksiginfo_init(&ksi);
1824 ksi.ksi_signo = uap->signum;
1825 ksi.ksi_code = SI_USER;
1826 ksi.ksi_pid = td->td_proc->p_pid;
1827 ksi.ksi_uid = td->td_ucred->cr_ruid;
1828 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi));
1829 }
1830 #endif /* COMPAT_43 */
1831
1832 #ifndef _SYS_SYSPROTO_H_
1833 struct sigqueue_args {
1834 pid_t pid;
1835 int signum;
1836 /* union sigval */ void *value;
1837 };
1838 #endif
1839 int
1840 sys_sigqueue(struct thread *td, struct sigqueue_args *uap)
1841 {
1842 ksiginfo_t ksi;
1843 struct proc *p;
1844 int error;
1845
1846 if ((u_int)uap->signum > _SIG_MAXSIG)
1847 return (EINVAL);
1848
1849 /*
1850 * Specification says sigqueue can only send signal to
1851 * single process.
1852 */
1853 if (uap->pid <= 0)
1854 return (EINVAL);
1855
1856 if ((p = pfind(uap->pid)) == NULL) {
1857 if ((p = zpfind(uap->pid)) == NULL)
1858 return (ESRCH);
1859 }
1860 error = p_cansignal(td, p, uap->signum);
1861 if (error == 0 && uap->signum != 0) {
1862 ksiginfo_init(&ksi);
1863 ksi.ksi_flags = KSI_SIGQ;
1864 ksi.ksi_signo = uap->signum;
1865 ksi.ksi_code = SI_QUEUE;
1866 ksi.ksi_pid = td->td_proc->p_pid;
1867 ksi.ksi_uid = td->td_ucred->cr_ruid;
1868 ksi.ksi_value.sival_ptr = uap->value;
1869 error = pksignal(p, ksi.ksi_signo, &ksi);
1870 }
1871 PROC_UNLOCK(p);
1872 return (error);
1873 }
1874
1875 /*
1876 * Send a signal to a process group.
1877 */
1878 void
1879 gsignal(int pgid, int sig, ksiginfo_t *ksi)
1880 {
1881 struct pgrp *pgrp;
1882
1883 if (pgid != 0) {
1884 sx_slock(&proctree_lock);
1885 pgrp = pgfind(pgid);
1886 sx_sunlock(&proctree_lock);
1887 if (pgrp != NULL) {
1888 pgsignal(pgrp, sig, 0, ksi);
1889 PGRP_UNLOCK(pgrp);
1890 }
1891 }
1892 }
1893
1894 /*
1895 * Send a signal to a process group. If checktty is 1,
1896 * limit to members which have a controlling terminal.
1897 */
1898 void
1899 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi)
1900 {
1901 struct proc *p;
1902
1903 if (pgrp) {
1904 PGRP_LOCK_ASSERT(pgrp, MA_OWNED);
1905 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
1906 PROC_LOCK(p);
1907 if (p->p_state == PRS_NORMAL &&
1908 (checkctty == 0 || p->p_flag & P_CONTROLT))
1909 pksignal(p, sig, ksi);
1910 PROC_UNLOCK(p);
1911 }
1912 }
1913 }
1914
1915
1916 /*
1917 * Recalculate the signal mask and reset the signal disposition after
1918 * usermode frame for delivery is formed. Should be called after
1919 * mach-specific routine, because sysent->sv_sendsig() needs correct
1920 * ps_siginfo and signal mask.
1921 */
1922 static void
1923 postsig_done(int sig, struct thread *td, struct sigacts *ps)
1924 {
1925 sigset_t mask;
1926
1927 mtx_assert(&ps->ps_mtx, MA_OWNED);
1928 td->td_ru.ru_nsignals++;
1929 mask = ps->ps_catchmask[_SIG_IDX(sig)];
1930 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1931 SIGADDSET(mask, sig);
1932 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL,
1933 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED);
1934 if (SIGISMEMBER(ps->ps_sigreset, sig))
1935 sigdflt(ps, sig);
1936 }
1937
1938
1939 /*
1940 * Send a signal caused by a trap to the current thread. If it will be
1941 * caught immediately, deliver it with correct code. Otherwise, post it
1942 * normally.
1943 */
1944 void
1945 trapsignal(struct thread *td, ksiginfo_t *ksi)
1946 {
1947 struct sigacts *ps;
1948 struct proc *p;
1949 int sig;
1950 int code;
1951
1952 p = td->td_proc;
1953 sig = ksi->ksi_signo;
1954 code = ksi->ksi_code;
1955 KASSERT(_SIG_VALID(sig), ("invalid signal"));
1956
1957 PROC_LOCK(p);
1958 ps = p->p_sigacts;
1959 mtx_lock(&ps->ps_mtx);
1960 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) &&
1961 !SIGISMEMBER(td->td_sigmask, sig)) {
1962 #ifdef KTRACE
1963 if (KTRPOINT(curthread, KTR_PSIG))
1964 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)],
1965 &td->td_sigmask, code);
1966 #endif
1967 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)],
1968 ksi, &td->td_sigmask);
1969 postsig_done(sig, td, ps);
1970 mtx_unlock(&ps->ps_mtx);
1971 } else {
1972 /*
1973 * Avoid a possible infinite loop if the thread
1974 * masking the signal or process is ignoring the
1975 * signal.
1976 */
1977 if (kern_forcesigexit &&
1978 (SIGISMEMBER(td->td_sigmask, sig) ||
1979 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) {
1980 SIGDELSET(td->td_sigmask, sig);
1981 SIGDELSET(ps->ps_sigcatch, sig);
1982 SIGDELSET(ps->ps_sigignore, sig);
1983 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1984 }
1985 mtx_unlock(&ps->ps_mtx);
1986 p->p_code = code; /* XXX for core dump/debugger */
1987 p->p_sig = sig; /* XXX to verify code */
1988 tdsendsignal(p, td, sig, ksi);
1989 }
1990 PROC_UNLOCK(p);
1991 }
1992
1993 static struct thread *
1994 sigtd(struct proc *p, int sig, int prop)
1995 {
1996 struct thread *td, *signal_td;
1997
1998 PROC_LOCK_ASSERT(p, MA_OWNED);
1999
2000 /*
2001 * Check if current thread can handle the signal without
2002 * switching context to another thread.
2003 */
2004 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig))
2005 return (curthread);
2006 signal_td = NULL;
2007 FOREACH_THREAD_IN_PROC(p, td) {
2008 if (!SIGISMEMBER(td->td_sigmask, sig)) {
2009 signal_td = td;
2010 break;
2011 }
2012 }
2013 if (signal_td == NULL)
2014 signal_td = FIRST_THREAD_IN_PROC(p);
2015 return (signal_td);
2016 }
2017
2018 /*
2019 * Send the signal to the process. If the signal has an action, the action
2020 * is usually performed by the target process rather than the caller; we add
2021 * the signal to the set of pending signals for the process.
2022 *
2023 * Exceptions:
2024 * o When a stop signal is sent to a sleeping process that takes the
2025 * default action, the process is stopped without awakening it.
2026 * o SIGCONT restarts stopped processes (or puts them back to sleep)
2027 * regardless of the signal action (eg, blocked or ignored).
2028 *
2029 * Other ignored signals are discarded immediately.
2030 *
2031 * NB: This function may be entered from the debugger via the "kill" DDB
2032 * command. There is little that can be done to mitigate the possibly messy
2033 * side effects of this unwise possibility.
2034 */
2035 void
2036 kern_psignal(struct proc *p, int sig)
2037 {
2038 ksiginfo_t ksi;
2039
2040 ksiginfo_init(&ksi);
2041 ksi.ksi_signo = sig;
2042 ksi.ksi_code = SI_KERNEL;
2043 (void) tdsendsignal(p, NULL, sig, &ksi);
2044 }
2045
2046 int
2047 pksignal(struct proc *p, int sig, ksiginfo_t *ksi)
2048 {
2049
2050 return (tdsendsignal(p, NULL, sig, ksi));
2051 }
2052
2053 /* Utility function for finding a thread to send signal event to. */
2054 int
2055 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd)
2056 {
2057 struct thread *td;
2058
2059 if (sigev->sigev_notify == SIGEV_THREAD_ID) {
2060 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid);
2061 if (td == NULL)
2062 return (ESRCH);
2063 *ttd = td;
2064 } else {
2065 *ttd = NULL;
2066 PROC_LOCK(p);
2067 }
2068 return (0);
2069 }
2070
2071 void
2072 tdsignal(struct thread *td, int sig)
2073 {
2074 ksiginfo_t ksi;
2075
2076 ksiginfo_init(&ksi);
2077 ksi.ksi_signo = sig;
2078 ksi.ksi_code = SI_KERNEL;
2079 (void) tdsendsignal(td->td_proc, td, sig, &ksi);
2080 }
2081
2082 void
2083 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi)
2084 {
2085
2086 (void) tdsendsignal(td->td_proc, td, sig, ksi);
2087 }
2088
2089 int
2090 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi)
2091 {
2092 sig_t action;
2093 sigqueue_t *sigqueue;
2094 int prop;
2095 struct sigacts *ps;
2096 int intrval;
2097 int ret = 0;
2098 int wakeup_swapper;
2099
2100 MPASS(td == NULL || p == td->td_proc);
2101 PROC_LOCK_ASSERT(p, MA_OWNED);
2102
2103 if (!_SIG_VALID(sig))
2104 panic("%s(): invalid signal %d", __func__, sig);
2105
2106 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__));
2107
2108 /*
2109 * IEEE Std 1003.1-2001: return success when killing a zombie.
2110 */
2111 if (p->p_state == PRS_ZOMBIE) {
2112 if (ksi && (ksi->ksi_flags & KSI_INS))
2113 ksiginfo_tryfree(ksi);
2114 return (ret);
2115 }
2116
2117 ps = p->p_sigacts;
2118 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig);
2119 prop = sigprop(sig);
2120
2121 if (td == NULL) {
2122 td = sigtd(p, sig, prop);
2123 sigqueue = &p->p_sigqueue;
2124 } else
2125 sigqueue = &td->td_sigqueue;
2126
2127 SDT_PROBE3(proc, , , signal__send, td, p, sig);
2128
2129 /*
2130 * If the signal is being ignored,
2131 * then we forget about it immediately.
2132 * (Note: we don't set SIGCONT in ps_sigignore,
2133 * and if it is set to SIG_IGN,
2134 * action will be SIG_DFL here.)
2135 */
2136 mtx_lock(&ps->ps_mtx);
2137 if (SIGISMEMBER(ps->ps_sigignore, sig)) {
2138 SDT_PROBE3(proc, , , signal__discard, td, p, sig);
2139
2140 mtx_unlock(&ps->ps_mtx);
2141 if (ksi && (ksi->ksi_flags & KSI_INS))
2142 ksiginfo_tryfree(ksi);
2143 return (ret);
2144 }
2145 if (SIGISMEMBER(td->td_sigmask, sig))
2146 action = SIG_HOLD;
2147 else if (SIGISMEMBER(ps->ps_sigcatch, sig))
2148 action = SIG_CATCH;
2149 else
2150 action = SIG_DFL;
2151 if (SIGISMEMBER(ps->ps_sigintr, sig))
2152 intrval = EINTR;
2153 else
2154 intrval = ERESTART;
2155 mtx_unlock(&ps->ps_mtx);
2156
2157 if (prop & SA_CONT)
2158 sigqueue_delete_stopmask_proc(p);
2159 else if (prop & SA_STOP) {
2160 /*
2161 * If sending a tty stop signal to a member of an orphaned
2162 * process group, discard the signal here if the action
2163 * is default; don't stop the process below if sleeping,
2164 * and don't clear any pending SIGCONT.
2165 */
2166 if ((prop & SA_TTYSTOP) &&
2167 (p->p_pgrp->pg_jobc == 0) &&
2168 (action == SIG_DFL)) {
2169 if (ksi && (ksi->ksi_flags & KSI_INS))
2170 ksiginfo_tryfree(ksi);
2171 return (ret);
2172 }
2173 sigqueue_delete_proc(p, SIGCONT);
2174 if (p->p_flag & P_CONTINUED) {
2175 p->p_flag &= ~P_CONTINUED;
2176 PROC_LOCK(p->p_pptr);
2177 sigqueue_take(p->p_ksi);
2178 PROC_UNLOCK(p->p_pptr);
2179 }
2180 }
2181
2182 ret = sigqueue_add(sigqueue, sig, ksi);
2183 if (ret != 0)
2184 return (ret);
2185 signotify(td);
2186 /*
2187 * Defer further processing for signals which are held,
2188 * except that stopped processes must be continued by SIGCONT.
2189 */
2190 if (action == SIG_HOLD &&
2191 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG)))
2192 return (ret);
2193 /*
2194 * SIGKILL: Remove procfs STOPEVENTs.
2195 */
2196 if (sig == SIGKILL) {
2197 /* from procfs_ioctl.c: PIOCBIC */
2198 p->p_stops = 0;
2199 /* from procfs_ioctl.c: PIOCCONT */
2200 p->p_step = 0;
2201 wakeup(&p->p_step);
2202 }
2203 /*
2204 * Some signals have a process-wide effect and a per-thread
2205 * component. Most processing occurs when the process next
2206 * tries to cross the user boundary, however there are some
2207 * times when processing needs to be done immediately, such as
2208 * waking up threads so that they can cross the user boundary.
2209 * We try to do the per-process part here.
2210 */
2211 if (P_SHOULDSTOP(p)) {
2212 KASSERT(!(p->p_flag & P_WEXIT),
2213 ("signal to stopped but exiting process"));
2214 if (sig == SIGKILL) {
2215 /*
2216 * If traced process is already stopped,
2217 * then no further action is necessary.
2218 */
2219 if (p->p_flag & P_TRACED)
2220 goto out;
2221 /*
2222 * SIGKILL sets process running.
2223 * It will die elsewhere.
2224 * All threads must be restarted.
2225 */
2226 p->p_flag &= ~P_STOPPED_SIG;
2227 goto runfast;
2228 }
2229
2230 if (prop & SA_CONT) {
2231 /*
2232 * If traced process is already stopped,
2233 * then no further action is necessary.
2234 */
2235 if (p->p_flag & P_TRACED)
2236 goto out;
2237 /*
2238 * If SIGCONT is default (or ignored), we continue the
2239 * process but don't leave the signal in sigqueue as
2240 * it has no further action. If SIGCONT is held, we
2241 * continue the process and leave the signal in
2242 * sigqueue. If the process catches SIGCONT, let it
2243 * handle the signal itself. If it isn't waiting on
2244 * an event, it goes back to run state.
2245 * Otherwise, process goes back to sleep state.
2246 */
2247 p->p_flag &= ~P_STOPPED_SIG;
2248 PROC_SLOCK(p);
2249 if (p->p_numthreads == p->p_suspcount) {
2250 PROC_SUNLOCK(p);
2251 p->p_flag |= P_CONTINUED;
2252 p->p_xsig = SIGCONT;
2253 PROC_LOCK(p->p_pptr);
2254 childproc_continued(p);
2255 PROC_UNLOCK(p->p_pptr);
2256 PROC_SLOCK(p);
2257 }
2258 if (action == SIG_DFL) {
2259 thread_unsuspend(p);
2260 PROC_SUNLOCK(p);
2261 sigqueue_delete(sigqueue, sig);
2262 goto out;
2263 }
2264 if (action == SIG_CATCH) {
2265 /*
2266 * The process wants to catch it so it needs
2267 * to run at least one thread, but which one?
2268 */
2269 PROC_SUNLOCK(p);
2270 goto runfast;
2271 }
2272 /*
2273 * The signal is not ignored or caught.
2274 */
2275 thread_unsuspend(p);
2276 PROC_SUNLOCK(p);
2277 goto out;
2278 }
2279
2280 if (prop & SA_STOP) {
2281 /*
2282 * If traced process is already stopped,
2283 * then no further action is necessary.
2284 */
2285 if (p->p_flag & P_TRACED)
2286 goto out;
2287 /*
2288 * Already stopped, don't need to stop again
2289 * (If we did the shell could get confused).
2290 * Just make sure the signal STOP bit set.
2291 */
2292 p->p_flag |= P_STOPPED_SIG;
2293 sigqueue_delete(sigqueue, sig);
2294 goto out;
2295 }
2296
2297 /*
2298 * All other kinds of signals:
2299 * If a thread is sleeping interruptibly, simulate a
2300 * wakeup so that when it is continued it will be made
2301 * runnable and can look at the signal. However, don't make
2302 * the PROCESS runnable, leave it stopped.
2303 * It may run a bit until it hits a thread_suspend_check().
2304 */
2305 wakeup_swapper = 0;
2306 PROC_SLOCK(p);
2307 thread_lock(td);
2308 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR))
2309 wakeup_swapper = sleepq_abort(td, intrval);
2310 thread_unlock(td);
2311 PROC_SUNLOCK(p);
2312 if (wakeup_swapper)
2313 kick_proc0();
2314 goto out;
2315 /*
2316 * Mutexes are short lived. Threads waiting on them will
2317 * hit thread_suspend_check() soon.
2318 */
2319 } else if (p->p_state == PRS_NORMAL) {
2320 if (p->p_flag & P_TRACED || action == SIG_CATCH) {
2321 tdsigwakeup(td, sig, action, intrval);
2322 goto out;
2323 }
2324
2325 MPASS(action == SIG_DFL);
2326
2327 if (prop & SA_STOP) {
2328 if (p->p_flag & (P_PPWAIT|P_WEXIT))
2329 goto out;
2330 p->p_flag |= P_STOPPED_SIG;
2331 p->p_xsig = sig;
2332 PROC_SLOCK(p);
2333 wakeup_swapper = sig_suspend_threads(td, p, 1);
2334 if (p->p_numthreads == p->p_suspcount) {
2335 /*
2336 * only thread sending signal to another
2337 * process can reach here, if thread is sending
2338 * signal to its process, because thread does
2339 * not suspend itself here, p_numthreads
2340 * should never be equal to p_suspcount.
2341 */
2342 thread_stopped(p);
2343 PROC_SUNLOCK(p);
2344 sigqueue_delete_proc(p, p->p_xsig);
2345 } else
2346 PROC_SUNLOCK(p);
2347 if (wakeup_swapper)
2348 kick_proc0();
2349 goto out;
2350 }
2351 } else {
2352 /* Not in "NORMAL" state. discard the signal. */
2353 sigqueue_delete(sigqueue, sig);
2354 goto out;
2355 }
2356
2357 /*
2358 * The process is not stopped so we need to apply the signal to all the
2359 * running threads.
2360 */
2361 runfast:
2362 tdsigwakeup(td, sig, action, intrval);
2363 PROC_SLOCK(p);
2364 thread_unsuspend(p);
2365 PROC_SUNLOCK(p);
2366 out:
2367 /* If we jump here, proc slock should not be owned. */
2368 PROC_SLOCK_ASSERT(p, MA_NOTOWNED);
2369 return (ret);
2370 }
2371
2372 /*
2373 * The force of a signal has been directed against a single
2374 * thread. We need to see what we can do about knocking it
2375 * out of any sleep it may be in etc.
2376 */
2377 static void
2378 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval)
2379 {
2380 struct proc *p = td->td_proc;
2381 register int prop;
2382 int wakeup_swapper;
2383
2384 wakeup_swapper = 0;
2385 PROC_LOCK_ASSERT(p, MA_OWNED);
2386 prop = sigprop(sig);
2387
2388 PROC_SLOCK(p);
2389 thread_lock(td);
2390 /*
2391 * Bring the priority of a thread up if we want it to get
2392 * killed in this lifetime. Be careful to avoid bumping the
2393 * priority of the idle thread, since we still allow to signal
2394 * kernel processes.
2395 */
2396 if (action == SIG_DFL && (prop & SA_KILL) != 0 &&
2397 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td))
2398 sched_prio(td, PUSER);
2399 if (TD_ON_SLEEPQ(td)) {
2400 /*
2401 * If thread is sleeping uninterruptibly
2402 * we can't interrupt the sleep... the signal will
2403 * be noticed when the process returns through
2404 * trap() or syscall().
2405 */
2406 if ((td->td_flags & TDF_SINTR) == 0)
2407 goto out;
2408 /*
2409 * If SIGCONT is default (or ignored) and process is
2410 * asleep, we are finished; the process should not
2411 * be awakened.
2412 */
2413 if ((prop & SA_CONT) && action == SIG_DFL) {
2414 thread_unlock(td);
2415 PROC_SUNLOCK(p);
2416 sigqueue_delete(&p->p_sigqueue, sig);
2417 /*
2418 * It may be on either list in this state.
2419 * Remove from both for now.
2420 */
2421 sigqueue_delete(&td->td_sigqueue, sig);
2422 return;
2423 }
2424
2425 /*
2426 * Don't awaken a sleeping thread for SIGSTOP if the
2427 * STOP signal is deferred.
2428 */
2429 if ((prop & SA_STOP) != 0 && (td->td_flags & (TDF_SBDRY |
2430 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY)
2431 goto out;
2432
2433 /*
2434 * Give low priority threads a better chance to run.
2435 */
2436 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td))
2437 sched_prio(td, PUSER);
2438
2439 wakeup_swapper = sleepq_abort(td, intrval);
2440 } else {
2441 /*
2442 * Other states do nothing with the signal immediately,
2443 * other than kicking ourselves if we are running.
2444 * It will either never be noticed, or noticed very soon.
2445 */
2446 #ifdef SMP
2447 if (TD_IS_RUNNING(td) && td != curthread)
2448 forward_signal(td);
2449 #endif
2450 }
2451 out:
2452 PROC_SUNLOCK(p);
2453 thread_unlock(td);
2454 if (wakeup_swapper)
2455 kick_proc0();
2456 }
2457
2458 static int
2459 sig_suspend_threads(struct thread *td, struct proc *p, int sending)
2460 {
2461 struct thread *td2;
2462 int wakeup_swapper;
2463
2464 PROC_LOCK_ASSERT(p, MA_OWNED);
2465 PROC_SLOCK_ASSERT(p, MA_OWNED);
2466
2467 wakeup_swapper = 0;
2468 FOREACH_THREAD_IN_PROC(p, td2) {
2469 thread_lock(td2);
2470 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK;
2471 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) &&
2472 (td2->td_flags & TDF_SINTR)) {
2473 if (td2->td_flags & TDF_SBDRY) {
2474 /*
2475 * Once a thread is asleep with
2476 * TDF_SBDRY and without TDF_SERESTART
2477 * or TDF_SEINTR set, it should never
2478 * become suspended due to this check.
2479 */
2480 KASSERT(!TD_IS_SUSPENDED(td2),
2481 ("thread with deferred stops suspended"));
2482 if (TD_SBDRY_INTR(td2) && sending) {
2483 wakeup_swapper |= sleepq_abort(td2,
2484 TD_SBDRY_ERRNO(td2));
2485 }
2486 } else if (!TD_IS_SUSPENDED(td2)) {
2487 thread_suspend_one(td2);
2488 }
2489 } else if (!TD_IS_SUSPENDED(td2)) {
2490 if (sending || td != td2)
2491 td2->td_flags |= TDF_ASTPENDING;
2492 #ifdef SMP
2493 if (TD_IS_RUNNING(td2) && td2 != td)
2494 forward_signal(td2);
2495 #endif
2496 }
2497 thread_unlock(td2);
2498 }
2499 return (wakeup_swapper);
2500 }
2501
2502 int
2503 ptracestop(struct thread *td, int sig)
2504 {
2505 struct proc *p = td->td_proc;
2506
2507 PROC_LOCK_ASSERT(p, MA_OWNED);
2508 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process"));
2509 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
2510 &p->p_mtx.lock_object, "Stopping for traced signal");
2511
2512 td->td_dbgflags |= TDB_XSIG;
2513 td->td_xsig = sig;
2514 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d",
2515 td->td_tid, p->p_pid, td->td_dbgflags, sig);
2516 PROC_SLOCK(p);
2517 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) {
2518 if (p->p_flag & P_SINGLE_EXIT &&
2519 !(td->td_dbgflags & TDB_EXIT)) {
2520 /*
2521 * Ignore ptrace stops except for thread exit
2522 * events when the process exits.
2523 */
2524 td->td_dbgflags &= ~TDB_XSIG;
2525 PROC_SUNLOCK(p);
2526 return (sig);
2527 }
2528 /*
2529 * Just make wait() to work, the last stopped thread
2530 * will win.
2531 */
2532 p->p_xsig = sig;
2533 p->p_xthread = td;
2534 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE);
2535 sig_suspend_threads(td, p, 0);
2536 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) {
2537 td->td_dbgflags &= ~TDB_STOPATFORK;
2538 cv_broadcast(&p->p_dbgwait);
2539 }
2540 stopme:
2541 thread_suspend_switch(td, p);
2542 if (p->p_xthread == td)
2543 p->p_xthread = NULL;
2544 if (!(p->p_flag & P_TRACED))
2545 break;
2546 if (td->td_dbgflags & TDB_SUSPEND) {
2547 if (p->p_flag & P_SINGLE_EXIT)
2548 break;
2549 goto stopme;
2550 }
2551 }
2552 PROC_SUNLOCK(p);
2553 return (td->td_xsig);
2554 }
2555
2556 static void
2557 reschedule_signals(struct proc *p, sigset_t block, int flags)
2558 {
2559 struct sigacts *ps;
2560 struct thread *td;
2561 int sig;
2562
2563 PROC_LOCK_ASSERT(p, MA_OWNED);
2564 ps = p->p_sigacts;
2565 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ?
2566 MA_OWNED : MA_NOTOWNED);
2567 if (SIGISEMPTY(p->p_siglist))
2568 return;
2569 SIGSETAND(block, p->p_siglist);
2570 while ((sig = sig_ffs(&block)) != 0) {
2571 SIGDELSET(block, sig);
2572 td = sigtd(p, sig, 0);
2573 signotify(td);
2574 if (!(flags & SIGPROCMASK_PS_LOCKED))
2575 mtx_lock(&ps->ps_mtx);
2576 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig))
2577 tdsigwakeup(td, sig, SIG_CATCH,
2578 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR :
2579 ERESTART));
2580 if (!(flags & SIGPROCMASK_PS_LOCKED))
2581 mtx_unlock(&ps->ps_mtx);
2582 }
2583 }
2584
2585 void
2586 tdsigcleanup(struct thread *td)
2587 {
2588 struct proc *p;
2589 sigset_t unblocked;
2590
2591 p = td->td_proc;
2592 PROC_LOCK_ASSERT(p, MA_OWNED);
2593
2594 sigqueue_flush(&td->td_sigqueue);
2595 if (p->p_numthreads == 1)
2596 return;
2597
2598 /*
2599 * Since we cannot handle signals, notify signal post code
2600 * about this by filling the sigmask.
2601 *
2602 * Also, if needed, wake up thread(s) that do not block the
2603 * same signals as the exiting thread, since the thread might
2604 * have been selected for delivery and woken up.
2605 */
2606 SIGFILLSET(unblocked);
2607 SIGSETNAND(unblocked, td->td_sigmask);
2608 SIGFILLSET(td->td_sigmask);
2609 reschedule_signals(p, unblocked, 0);
2610
2611 }
2612
2613 static int
2614 sigdeferstop_curr_flags(int cflags)
2615 {
2616
2617 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 ||
2618 (cflags & TDF_SBDRY) != 0);
2619 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART));
2620 }
2621
2622 /*
2623 * Defer the delivery of SIGSTOP for the current thread, according to
2624 * the requested mode. Returns previous flags, which must be restored
2625 * by sigallowstop().
2626 *
2627 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and
2628 * cleared by the current thread, which allow the lock-less read-only
2629 * accesses below.
2630 */
2631 int
2632 sigdeferstop_impl(int mode)
2633 {
2634 struct thread *td;
2635 int cflags, nflags;
2636
2637 td = curthread;
2638 cflags = sigdeferstop_curr_flags(td->td_flags);
2639 switch (mode) {
2640 case SIGDEFERSTOP_NOP:
2641 nflags = cflags;
2642 break;
2643 case SIGDEFERSTOP_OFF:
2644 nflags = 0;
2645 break;
2646 case SIGDEFERSTOP_SILENT:
2647 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART);
2648 break;
2649 case SIGDEFERSTOP_EINTR:
2650 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART;
2651 break;
2652 case SIGDEFERSTOP_ERESTART:
2653 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR;
2654 break;
2655 default:
2656 panic("sigdeferstop: invalid mode %x", mode);
2657 break;
2658 }
2659 if (cflags == nflags)
2660 return (SIGDEFERSTOP_VAL_NCHG);
2661 thread_lock(td);
2662 td->td_flags = (td->td_flags & ~cflags) | nflags;
2663 thread_unlock(td);
2664 return (cflags);
2665 }
2666
2667 /*
2668 * Restores the STOP handling mode, typically permitting the delivery
2669 * of SIGSTOP for the current thread. This does not immediately
2670 * suspend if a stop was posted. Instead, the thread will suspend
2671 * either via ast() or a subsequent interruptible sleep.
2672 */
2673 void
2674 sigallowstop_impl(int prev)
2675 {
2676 struct thread *td;
2677 int cflags;
2678
2679 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop"));
2680 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0,
2681 ("sigallowstop: incorrect previous mode %x", prev));
2682 td = curthread;
2683 cflags = sigdeferstop_curr_flags(td->td_flags);
2684 if (cflags != prev) {
2685 thread_lock(td);
2686 td->td_flags = (td->td_flags & ~cflags) | prev;
2687 thread_unlock(td);
2688 }
2689 }
2690
2691 /*
2692 * If the current process has received a signal (should be caught or cause
2693 * termination, should interrupt current syscall), return the signal number.
2694 * Stop signals with default action are processed immediately, then cleared;
2695 * they aren't returned. This is checked after each entry to the system for
2696 * a syscall or trap (though this can usually be done without calling issignal
2697 * by checking the pending signal masks in cursig.) The normal call
2698 * sequence is
2699 *
2700 * while (sig = cursig(curthread))
2701 * postsig(sig);
2702 */
2703 static int
2704 issignal(struct thread *td)
2705 {
2706 struct proc *p;
2707 struct sigacts *ps;
2708 struct sigqueue *queue;
2709 sigset_t sigpending;
2710 int sig, prop, newsig;
2711
2712 p = td->td_proc;
2713 ps = p->p_sigacts;
2714 mtx_assert(&ps->ps_mtx, MA_OWNED);
2715 PROC_LOCK_ASSERT(p, MA_OWNED);
2716 for (;;) {
2717 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
2718
2719 sigpending = td->td_sigqueue.sq_signals;
2720 SIGSETOR(sigpending, p->p_sigqueue.sq_signals);
2721 SIGSETNAND(sigpending, td->td_sigmask);
2722
2723 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags &
2724 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY)
2725 SIG_STOPSIGMASK(sigpending);
2726 if (SIGISEMPTY(sigpending)) /* no signal to send */
2727 return (0);
2728 sig = sig_ffs(&sigpending);
2729
2730 if (p->p_stops & S_SIG) {
2731 mtx_unlock(&ps->ps_mtx);
2732 stopevent(p, S_SIG, sig);
2733 mtx_lock(&ps->ps_mtx);
2734 }
2735
2736 /*
2737 * We should see pending but ignored signals
2738 * only if P_TRACED was on when they were posted.
2739 */
2740 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) {
2741 sigqueue_delete(&td->td_sigqueue, sig);
2742 sigqueue_delete(&p->p_sigqueue, sig);
2743 continue;
2744 }
2745 if (p->p_flag & P_TRACED && (p->p_flag & P_PPTRACE) == 0) {
2746 /*
2747 * If traced, always stop.
2748 * Remove old signal from queue before the stop.
2749 * XXX shrug off debugger, it causes siginfo to
2750 * be thrown away.
2751 */
2752 queue = &td->td_sigqueue;
2753 td->td_dbgksi.ksi_signo = 0;
2754 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) {
2755 queue = &p->p_sigqueue;
2756 sigqueue_get(queue, sig, &td->td_dbgksi);
2757 }
2758
2759 mtx_unlock(&ps->ps_mtx);
2760 newsig = ptracestop(td, sig);
2761 mtx_lock(&ps->ps_mtx);
2762
2763 if (sig != newsig) {
2764
2765 /*
2766 * If parent wants us to take the signal,
2767 * then it will leave it in p->p_xsig;
2768 * otherwise we just look for signals again.
2769 */
2770 if (newsig == 0)
2771 continue;
2772 sig = newsig;
2773
2774 /*
2775 * Put the new signal into td_sigqueue. If the
2776 * signal is being masked, look for other
2777 * signals.
2778 */
2779 sigqueue_add(queue, sig, NULL);
2780 if (SIGISMEMBER(td->td_sigmask, sig))
2781 continue;
2782 signotify(td);
2783 } else {
2784 if (td->td_dbgksi.ksi_signo != 0) {
2785 td->td_dbgksi.ksi_flags |= KSI_HEAD;
2786 if (sigqueue_add(&td->td_sigqueue, sig,
2787 &td->td_dbgksi) != 0)
2788 td->td_dbgksi.ksi_signo = 0;
2789 }
2790 if (td->td_dbgksi.ksi_signo == 0)
2791 sigqueue_add(&td->td_sigqueue, sig,
2792 NULL);
2793 }
2794
2795 /*
2796 * If the traced bit got turned off, go back up
2797 * to the top to rescan signals. This ensures
2798 * that p_sig* and p_sigact are consistent.
2799 */
2800 if ((p->p_flag & P_TRACED) == 0)
2801 continue;
2802 }
2803
2804 prop = sigprop(sig);
2805
2806 /*
2807 * Decide whether the signal should be returned.
2808 * Return the signal's number, or fall through
2809 * to clear it from the pending mask.
2810 */
2811 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
2812
2813 case (intptr_t)SIG_DFL:
2814 /*
2815 * Don't take default actions on system processes.
2816 */
2817 if (p->p_pid <= 1) {
2818 #ifdef DIAGNOSTIC
2819 /*
2820 * Are you sure you want to ignore SIGSEGV
2821 * in init? XXX
2822 */
2823 printf("Process (pid %lu) got signal %d\n",
2824 (u_long)p->p_pid, sig);
2825 #endif
2826 break; /* == ignore */
2827 }
2828 /*
2829 * If there is a pending stop signal to process
2830 * with default action, stop here,
2831 * then clear the signal. However,
2832 * if process is member of an orphaned
2833 * process group, ignore tty stop signals.
2834 */
2835 if (prop & SA_STOP) {
2836 if (p->p_flag & (P_TRACED|P_WEXIT) ||
2837 (p->p_pgrp->pg_jobc == 0 &&
2838 prop & SA_TTYSTOP))
2839 break; /* == ignore */
2840 if (TD_SBDRY_INTR(td)) {
2841 KASSERT((td->td_flags & TDF_SBDRY) != 0,
2842 ("lost TDF_SBDRY"));
2843 return (-1);
2844 }
2845 mtx_unlock(&ps->ps_mtx);
2846 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
2847 &p->p_mtx.lock_object, "Catching SIGSTOP");
2848 p->p_flag |= P_STOPPED_SIG;
2849 p->p_xsig = sig;
2850 PROC_SLOCK(p);
2851 sig_suspend_threads(td, p, 0);
2852 thread_suspend_switch(td, p);
2853 PROC_SUNLOCK(p);
2854 mtx_lock(&ps->ps_mtx);
2855 break;
2856 } else if (prop & SA_IGNORE) {
2857 /*
2858 * Except for SIGCONT, shouldn't get here.
2859 * Default action is to ignore; drop it.
2860 */
2861 break; /* == ignore */
2862 } else
2863 return (sig);
2864 /*NOTREACHED*/
2865
2866 case (intptr_t)SIG_IGN:
2867 /*
2868 * Masking above should prevent us ever trying
2869 * to take action on an ignored signal other
2870 * than SIGCONT, unless process is traced.
2871 */
2872 if ((prop & SA_CONT) == 0 &&
2873 (p->p_flag & P_TRACED) == 0)
2874 printf("issignal\n");
2875 break; /* == ignore */
2876
2877 default:
2878 /*
2879 * This signal has an action, let
2880 * postsig() process it.
2881 */
2882 return (sig);
2883 }
2884 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */
2885 sigqueue_delete(&p->p_sigqueue, sig);
2886 }
2887 /* NOTREACHED */
2888 }
2889
2890 void
2891 thread_stopped(struct proc *p)
2892 {
2893 int n;
2894
2895 PROC_LOCK_ASSERT(p, MA_OWNED);
2896 PROC_SLOCK_ASSERT(p, MA_OWNED);
2897 n = p->p_suspcount;
2898 if (p == curproc)
2899 n++;
2900 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) {
2901 PROC_SUNLOCK(p);
2902 p->p_flag &= ~P_WAITED;
2903 PROC_LOCK(p->p_pptr);
2904 childproc_stopped(p, (p->p_flag & P_TRACED) ?
2905 CLD_TRAPPED : CLD_STOPPED);
2906 PROC_UNLOCK(p->p_pptr);
2907 PROC_SLOCK(p);
2908 }
2909 }
2910
2911 /*
2912 * Take the action for the specified signal
2913 * from the current set of pending signals.
2914 */
2915 int
2916 postsig(sig)
2917 register int sig;
2918 {
2919 struct thread *td = curthread;
2920 register struct proc *p = td->td_proc;
2921 struct sigacts *ps;
2922 sig_t action;
2923 ksiginfo_t ksi;
2924 sigset_t returnmask;
2925
2926 KASSERT(sig != 0, ("postsig"));
2927
2928 PROC_LOCK_ASSERT(p, MA_OWNED);
2929 ps = p->p_sigacts;
2930 mtx_assert(&ps->ps_mtx, MA_OWNED);
2931 ksiginfo_init(&ksi);
2932 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 &&
2933 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0)
2934 return (0);
2935 ksi.ksi_signo = sig;
2936 if (ksi.ksi_code == SI_TIMER)
2937 itimer_accept(p, ksi.ksi_timerid, &ksi);
2938 action = ps->ps_sigact[_SIG_IDX(sig)];
2939 #ifdef KTRACE
2940 if (KTRPOINT(td, KTR_PSIG))
2941 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ?
2942 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code);
2943 #endif
2944 if (p->p_stops & S_SIG) {
2945 mtx_unlock(&ps->ps_mtx);
2946 stopevent(p, S_SIG, sig);
2947 mtx_lock(&ps->ps_mtx);
2948 }
2949
2950 if (action == SIG_DFL) {
2951 /*
2952 * Default action, where the default is to kill
2953 * the process. (Other cases were ignored above.)
2954 */
2955 mtx_unlock(&ps->ps_mtx);
2956 sigexit(td, sig);
2957 /* NOTREACHED */
2958 } else {
2959 /*
2960 * If we get here, the signal must be caught.
2961 */
2962 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig),
2963 ("postsig action"));
2964 /*
2965 * Set the new mask value and also defer further
2966 * occurrences of this signal.
2967 *
2968 * Special case: user has done a sigsuspend. Here the
2969 * current mask is not of interest, but rather the
2970 * mask from before the sigsuspend is what we want
2971 * restored after the signal processing is completed.
2972 */
2973 if (td->td_pflags & TDP_OLDMASK) {
2974 returnmask = td->td_oldsigmask;
2975 td->td_pflags &= ~TDP_OLDMASK;
2976 } else
2977 returnmask = td->td_sigmask;
2978
2979 if (p->p_sig == sig) {
2980 p->p_code = 0;
2981 p->p_sig = 0;
2982 }
2983 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask);
2984 postsig_done(sig, td, ps);
2985 }
2986 return (1);
2987 }
2988
2989 /*
2990 * Kill the current process for stated reason.
2991 */
2992 void
2993 killproc(p, why)
2994 struct proc *p;
2995 char *why;
2996 {
2997
2998 PROC_LOCK_ASSERT(p, MA_OWNED);
2999 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid,
3000 p->p_comm);
3001 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid,
3002 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why);
3003 p->p_flag |= P_WKILLED;
3004 kern_psignal(p, SIGKILL);
3005 }
3006
3007 /*
3008 * Force the current process to exit with the specified signal, dumping core
3009 * if appropriate. We bypass the normal tests for masked and caught signals,
3010 * allowing unrecoverable failures to terminate the process without changing
3011 * signal state. Mark the accounting record with the signal termination.
3012 * If dumping core, save the signal number for the debugger. Calls exit and
3013 * does not return.
3014 */
3015 void
3016 sigexit(td, sig)
3017 struct thread *td;
3018 int sig;
3019 {
3020 struct proc *p = td->td_proc;
3021
3022 PROC_LOCK_ASSERT(p, MA_OWNED);
3023 p->p_acflag |= AXSIG;
3024 /*
3025 * We must be single-threading to generate a core dump. This
3026 * ensures that the registers in the core file are up-to-date.
3027 * Also, the ELF dump handler assumes that the thread list doesn't
3028 * change out from under it.
3029 *
3030 * XXX If another thread attempts to single-thread before us
3031 * (e.g. via fork()), we won't get a dump at all.
3032 */
3033 if ((sigprop(sig) & SA_CORE) && thread_single(p, SINGLE_NO_EXIT) == 0) {
3034 p->p_sig = sig;
3035 /*
3036 * Log signals which would cause core dumps
3037 * (Log as LOG_INFO to appease those who don't want
3038 * these messages.)
3039 * XXX : Todo, as well as euid, write out ruid too
3040 * Note that coredump() drops proc lock.
3041 */
3042 if (coredump(td) == 0)
3043 sig |= WCOREFLAG;
3044 if (kern_logsigexit)
3045 log(LOG_INFO,
3046 "pid %d (%s), uid %d: exited on signal %d%s\n",
3047 p->p_pid, p->p_comm,
3048 td->td_ucred ? td->td_ucred->cr_uid : -1,
3049 sig &~ WCOREFLAG,
3050 sig & WCOREFLAG ? " (core dumped)" : "");
3051 } else
3052 PROC_UNLOCK(p);
3053 exit1(td, 0, sig);
3054 /* NOTREACHED */
3055 }
3056
3057 /*
3058 * Send queued SIGCHLD to parent when child process's state
3059 * is changed.
3060 */
3061 static void
3062 sigparent(struct proc *p, int reason, int status)
3063 {
3064 PROC_LOCK_ASSERT(p, MA_OWNED);
3065 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
3066
3067 if (p->p_ksi != NULL) {
3068 p->p_ksi->ksi_signo = SIGCHLD;
3069 p->p_ksi->ksi_code = reason;
3070 p->p_ksi->ksi_status = status;
3071 p->p_ksi->ksi_pid = p->p_pid;
3072 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid;
3073 if (KSI_ONQ(p->p_ksi))
3074 return;
3075 }
3076 pksignal(p->p_pptr, SIGCHLD, p->p_ksi);
3077 }
3078
3079 static void
3080 childproc_jobstate(struct proc *p, int reason, int sig)
3081 {
3082 struct sigacts *ps;
3083
3084 PROC_LOCK_ASSERT(p, MA_OWNED);
3085 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
3086
3087 /*
3088 * Wake up parent sleeping in kern_wait(), also send
3089 * SIGCHLD to parent, but SIGCHLD does not guarantee
3090 * that parent will awake, because parent may masked
3091 * the signal.
3092 */
3093 p->p_pptr->p_flag |= P_STATCHILD;
3094 wakeup(p->p_pptr);
3095
3096 ps = p->p_pptr->p_sigacts;
3097 mtx_lock(&ps->ps_mtx);
3098 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) {
3099 mtx_unlock(&ps->ps_mtx);
3100 sigparent(p, reason, sig);
3101 } else
3102 mtx_unlock(&ps->ps_mtx);
3103 }
3104
3105 void
3106 childproc_stopped(struct proc *p, int reason)
3107 {
3108
3109 childproc_jobstate(p, reason, p->p_xsig);
3110 }
3111
3112 void
3113 childproc_continued(struct proc *p)
3114 {
3115 childproc_jobstate(p, CLD_CONTINUED, SIGCONT);
3116 }
3117
3118 void
3119 childproc_exited(struct proc *p)
3120 {
3121 int reason, status;
3122
3123 if (WCOREDUMP(p->p_xsig)) {
3124 reason = CLD_DUMPED;
3125 status = WTERMSIG(p->p_xsig);
3126 } else if (WIFSIGNALED(p->p_xsig)) {
3127 reason = CLD_KILLED;
3128 status = WTERMSIG(p->p_xsig);
3129 } else {
3130 reason = CLD_EXITED;
3131 status = p->p_xexit;
3132 }
3133 /*
3134 * XXX avoid calling wakeup(p->p_pptr), the work is
3135 * done in exit1().
3136 */
3137 sigparent(p, reason, status);
3138 }
3139
3140 /*
3141 * We only have 1 character for the core count in the format
3142 * string, so the range will be 0-9
3143 */
3144 #define MAX_NUM_CORES 10
3145 static int num_cores = 5;
3146
3147 static int
3148 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS)
3149 {
3150 int error;
3151 int new_val;
3152
3153 new_val = num_cores;
3154 error = sysctl_handle_int(oidp, &new_val, 0, req);
3155 if (error != 0 || req->newptr == NULL)
3156 return (error);
3157 if (new_val > MAX_NUM_CORES)
3158 new_val = MAX_NUM_CORES;
3159 if (new_val < 0)
3160 new_val = 0;
3161 num_cores = new_val;
3162 return (0);
3163 }
3164 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW,
3165 0, sizeof(int), sysctl_debug_num_cores_check, "I", "");
3166
3167 #define GZ_SUFFIX ".gz"
3168
3169 #ifdef GZIO
3170 static int compress_user_cores = 1;
3171 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RWTUN,
3172 &compress_user_cores, 0, "Compression of user corefiles");
3173
3174 int compress_user_cores_gzlevel = 6;
3175 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RWTUN,
3176 &compress_user_cores_gzlevel, 0, "Corefile gzip compression level");
3177 #else
3178 static int compress_user_cores = 0;
3179 #endif
3180
3181 /*
3182 * Protect the access to corefilename[] by allproc_lock.
3183 */
3184 #define corefilename_lock allproc_lock
3185
3186 static char corefilename[MAXPATHLEN] = {"%N.core"};
3187 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename));
3188
3189 static int
3190 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS)
3191 {
3192 int error;
3193
3194 sx_xlock(&corefilename_lock);
3195 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename),
3196 req);
3197 sx_xunlock(&corefilename_lock);
3198
3199 return (error);
3200 }
3201 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW |
3202 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A",
3203 "Process corefile name format string");
3204
3205 /*
3206 * corefile_open(comm, uid, pid, td, compress, vpp, namep)
3207 * Expand the name described in corefilename, using name, uid, and pid
3208 * and open/create core file.
3209 * corefilename is a printf-like string, with three format specifiers:
3210 * %N name of process ("name")
3211 * %P process id (pid)
3212 * %U user id (uid)
3213 * For example, "%N.core" is the default; they can be disabled completely
3214 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
3215 * This is controlled by the sysctl variable kern.corefile (see above).
3216 */
3217 static int
3218 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td,
3219 int compress, struct vnode **vpp, char **namep)
3220 {
3221 struct nameidata nd;
3222 struct sbuf sb;
3223 const char *format;
3224 char *hostname, *name;
3225 int indexpos, i, error, cmode, flags, oflags;
3226
3227 hostname = NULL;
3228 format = corefilename;
3229 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO);
3230 indexpos = -1;
3231 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN);
3232 sx_slock(&corefilename_lock);
3233 for (i = 0; format[i] != '\0'; i++) {
3234 switch (format[i]) {
3235 case '%': /* Format character */
3236 i++;
3237 switch (format[i]) {
3238 case '%':
3239 sbuf_putc(&sb, '%');
3240 break;
3241 case 'H': /* hostname */
3242 if (hostname == NULL) {
3243 hostname = malloc(MAXHOSTNAMELEN,
3244 M_TEMP, M_WAITOK);
3245 }
3246 getcredhostname(td->td_ucred, hostname,
3247 MAXHOSTNAMELEN);
3248 sbuf_printf(&sb, "%s", hostname);
3249 break;
3250 case 'I': /* autoincrementing index */
3251 sbuf_printf(&sb, "");
3252 indexpos = sbuf_len(&sb) - 1;
3253 break;
3254 case 'N': /* process name */
3255 sbuf_printf(&sb, "%s", comm);
3256 break;
3257 case 'P': /* process id */
3258 sbuf_printf(&sb, "%u", pid);
3259 break;
3260 case 'U': /* user id */
3261 sbuf_printf(&sb, "%u", uid);
3262 break;
3263 default:
3264 log(LOG_ERR,
3265 "Unknown format character %c in "
3266 "corename `%s'\n", format[i], format);
3267 break;
3268 }
3269 break;
3270 default:
3271 sbuf_putc(&sb, format[i]);
3272 break;
3273 }
3274 }
3275 sx_sunlock(&corefilename_lock);
3276 free(hostname, M_TEMP);
3277 if (compress)
3278 sbuf_printf(&sb, GZ_SUFFIX);
3279 if (sbuf_error(&sb) != 0) {
3280 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too "
3281 "long\n", (long)pid, comm, (u_long)uid);
3282 sbuf_delete(&sb);
3283 free(name, M_TEMP);
3284 return (ENOMEM);
3285 }
3286 sbuf_finish(&sb);
3287 sbuf_delete(&sb);
3288
3289 cmode = S_IRUSR | S_IWUSR;
3290 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE |
3291 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0);
3292
3293 /*
3294 * If the core format has a %I in it, then we need to check
3295 * for existing corefiles before returning a name.
3296 * To do this we iterate over 0..num_cores to find a
3297 * non-existing core file name to use.
3298 */
3299 if (indexpos != -1) {
3300 for (i = 0; i < num_cores; i++) {
3301 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW;
3302 name[indexpos] = '' + i;
3303 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td);
3304 error = vn_open_cred(&nd, &flags, cmode, oflags,
3305 td->td_ucred, NULL);
3306 if (error) {
3307 if (error == EEXIST)
3308 continue;
3309 log(LOG_ERR,
3310 "pid %d (%s), uid (%u): Path `%s' failed "
3311 "on initial open test, error = %d\n",
3312 pid, comm, uid, name, error);
3313 }
3314 goto out;
3315 }
3316 }
3317
3318 flags = O_CREAT | FWRITE | O_NOFOLLOW;
3319 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td);
3320 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL);
3321 out:
3322 if (error) {
3323 #ifdef AUDIT
3324 audit_proc_coredump(td, name, error);
3325 #endif
3326 free(name, M_TEMP);
3327 return (error);
3328 }
3329 NDFREE(&nd, NDF_ONLY_PNBUF);
3330 *vpp = nd.ni_vp;
3331 *namep = name;
3332 return (0);
3333 }
3334
3335 static int
3336 coredump_sanitise_path(const char *path)
3337 {
3338 size_t i;
3339
3340 /*
3341 * Only send a subset of ASCII to devd(8) because it
3342 * might pass these strings to sh -c.
3343 */
3344 for (i = 0; path[i]; i++)
3345 if (!(isalpha(path[i]) || isdigit(path[i])) &&
3346 path[i] != '/' && path[i] != '.' &&
3347 path[i] != '-')
3348 return (0);
3349
3350 return (1);
3351 }
3352
3353 /*
3354 * Dump a process' core. The main routine does some
3355 * policy checking, and creates the name of the coredump;
3356 * then it passes on a vnode and a size limit to the process-specific
3357 * coredump routine if there is one; if there _is not_ one, it returns
3358 * ENOSYS; otherwise it returns the error from the process-specific routine.
3359 */
3360
3361 static int
3362 coredump(struct thread *td)
3363 {
3364 struct proc *p = td->td_proc;
3365 struct ucred *cred = td->td_ucred;
3366 struct vnode *vp;
3367 struct flock lf;
3368 struct vattr vattr;
3369 int error, error1, locked;
3370 char *name; /* name of corefile */
3371 void *rl_cookie;
3372 off_t limit;
3373 char *data = NULL;
3374 char *fullpath, *freepath = NULL;
3375 size_t len;
3376 static const char comm_name[] = "comm=";
3377 static const char core_name[] = "core=";
3378
3379 PROC_LOCK_ASSERT(p, MA_OWNED);
3380 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td);
3381 _STOPEVENT(p, S_CORE, 0);
3382
3383 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) ||
3384 (p->p_flag2 & P2_NOTRACE) != 0) {
3385 PROC_UNLOCK(p);
3386 return (EFAULT);
3387 }
3388
3389 /*
3390 * Note that the bulk of limit checking is done after
3391 * the corefile is created. The exception is if the limit
3392 * for corefiles is 0, in which case we don't bother
3393 * creating the corefile at all. This layout means that
3394 * a corefile is truncated instead of not being created,
3395 * if it is larger than the limit.
3396 */
3397 limit = (off_t)lim_cur(td, RLIMIT_CORE);
3398 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) {
3399 PROC_UNLOCK(p);
3400 return (EFBIG);
3401 }
3402 PROC_UNLOCK(p);
3403
3404 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td,
3405 compress_user_cores, &vp, &name);
3406 if (error != 0)
3407 return (error);
3408
3409 /*
3410 * Don't dump to non-regular files or files with links.
3411 * Do not dump into system files.
3412 */
3413 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 ||
3414 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0) {
3415 VOP_UNLOCK(vp, 0);
3416 error = EFAULT;
3417 goto out;
3418 }
3419
3420 VOP_UNLOCK(vp, 0);
3421
3422 /* Postpone other writers, including core dumps of other processes. */
3423 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
3424
3425 lf.l_whence = SEEK_SET;
3426 lf.l_start = 0;
3427 lf.l_len = 0;
3428 lf.l_type = F_WRLCK;
3429 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0);
3430
3431 VATTR_NULL(&vattr);
3432 vattr.va_size = 0;
3433 if (set_core_nodump_flag)
3434 vattr.va_flags = UF_NODUMP;
3435 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3436 VOP_SETATTR(vp, &vattr, cred);
3437 VOP_UNLOCK(vp, 0);
3438 PROC_LOCK(p);
3439 p->p_acflag |= ACORE;
3440 PROC_UNLOCK(p);
3441
3442 if (p->p_sysent->sv_coredump != NULL) {
3443 error = p->p_sysent->sv_coredump(td, vp, limit,
3444 compress_user_cores ? IMGACT_CORE_COMPRESS : 0);
3445 } else {
3446 error = ENOSYS;
3447 }
3448
3449 if (locked) {
3450 lf.l_type = F_UNLCK;
3451 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
3452 }
3453 vn_rangelock_unlock(vp, rl_cookie);
3454
3455 /*
3456 * Notify the userland helper that a process triggered a core dump.
3457 * This allows the helper to run an automated debugging session.
3458 */
3459 if (error != 0 || coredump_devctl == 0)
3460 goto out;
3461 len = MAXPATHLEN * 2 + sizeof(comm_name) - 1 +
3462 sizeof(' ') + sizeof(core_name) - 1;
3463 data = malloc(len, M_TEMP, M_WAITOK);
3464 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0)
3465 goto out;
3466 if (!coredump_sanitise_path(fullpath))
3467 goto out;
3468 snprintf(data, len, "%s%s ", comm_name, fullpath);
3469 free(freepath, M_TEMP);
3470 freepath = NULL;
3471 if (vn_fullpath_global(td, vp, &fullpath, &freepath) != 0)
3472 goto out;
3473 if (!coredump_sanitise_path(fullpath))
3474 goto out;
3475 strlcat(data, core_name, len);
3476 strlcat(data, fullpath, len);
3477 devctl_notify("kernel", "signal", "coredump", data);
3478 out:
3479 error1 = vn_close(vp, FWRITE, cred, td);
3480 if (error == 0)
3481 error = error1;
3482 #ifdef AUDIT
3483 audit_proc_coredump(td, name, error);
3484 #endif
3485 free(freepath, M_TEMP);
3486 free(data, M_TEMP);
3487 free(name, M_TEMP);
3488 return (error);
3489 }
3490
3491 /*
3492 * Nonexistent system call-- signal process (may want to handle it). Flag
3493 * error in case process won't see signal immediately (blocked or ignored).
3494 */
3495 #ifndef _SYS_SYSPROTO_H_
3496 struct nosys_args {
3497 int dummy;
3498 };
3499 #endif
3500 /* ARGSUSED */
3501 int
3502 nosys(td, args)
3503 struct thread *td;
3504 struct nosys_args *args;
3505 {
3506 struct proc *p = td->td_proc;
3507
3508 PROC_LOCK(p);
3509 tdsignal(td, SIGSYS);
3510 PROC_UNLOCK(p);
3511 return (ENOSYS);
3512 }
3513
3514 /*
3515 * Send a SIGIO or SIGURG signal to a process or process group using stored
3516 * credentials rather than those of the current process.
3517 */
3518 void
3519 pgsigio(sigiop, sig, checkctty)
3520 struct sigio **sigiop;
3521 int sig, checkctty;
3522 {
3523 ksiginfo_t ksi;
3524 struct sigio *sigio;
3525
3526 ksiginfo_init(&ksi);
3527 ksi.ksi_signo = sig;
3528 ksi.ksi_code = SI_KERNEL;
3529
3530 SIGIO_LOCK();
3531 sigio = *sigiop;
3532 if (sigio == NULL) {
3533 SIGIO_UNLOCK();
3534 return;
3535 }
3536 if (sigio->sio_pgid > 0) {
3537 PROC_LOCK(sigio->sio_proc);
3538 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred))
3539 kern_psignal(sigio->sio_proc, sig);
3540 PROC_UNLOCK(sigio->sio_proc);
3541 } else if (sigio->sio_pgid < 0) {
3542 struct proc *p;
3543
3544 PGRP_LOCK(sigio->sio_pgrp);
3545 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
3546 PROC_LOCK(p);
3547 if (p->p_state == PRS_NORMAL &&
3548 CANSIGIO(sigio->sio_ucred, p->p_ucred) &&
3549 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
3550 kern_psignal(p, sig);
3551 PROC_UNLOCK(p);
3552 }
3553 PGRP_UNLOCK(sigio->sio_pgrp);
3554 }
3555 SIGIO_UNLOCK();
3556 }
3557
3558 static int
3559 filt_sigattach(struct knote *kn)
3560 {
3561 struct proc *p = curproc;
3562
3563 kn->kn_ptr.p_proc = p;
3564 kn->kn_flags |= EV_CLEAR; /* automatically set */
3565
3566 knlist_add(p->p_klist, kn, 0);
3567
3568 return (0);
3569 }
3570
3571 static void
3572 filt_sigdetach(struct knote *kn)
3573 {
3574 struct proc *p = kn->kn_ptr.p_proc;
3575
3576 knlist_remove(p->p_klist, kn, 0);
3577 }
3578
3579 /*
3580 * signal knotes are shared with proc knotes, so we apply a mask to
3581 * the hint in order to differentiate them from process hints. This
3582 * could be avoided by using a signal-specific knote list, but probably
3583 * isn't worth the trouble.
3584 */
3585 static int
3586 filt_signal(struct knote *kn, long hint)
3587 {
3588
3589 if (hint & NOTE_SIGNAL) {
3590 hint &= ~NOTE_SIGNAL;
3591
3592 if (kn->kn_id == hint)
3593 kn->kn_data++;
3594 }
3595 return (kn->kn_data != 0);
3596 }
3597
3598 struct sigacts *
3599 sigacts_alloc(void)
3600 {
3601 struct sigacts *ps;
3602
3603 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO);
3604 refcount_init(&ps->ps_refcnt, 1);
3605 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF);
3606 return (ps);
3607 }
3608
3609 void
3610 sigacts_free(struct sigacts *ps)
3611 {
3612
3613 if (refcount_release(&ps->ps_refcnt) == 0)
3614 return;
3615 mtx_destroy(&ps->ps_mtx);
3616 free(ps, M_SUBPROC);
3617 }
3618
3619 struct sigacts *
3620 sigacts_hold(struct sigacts *ps)
3621 {
3622
3623 refcount_acquire(&ps->ps_refcnt);
3624 return (ps);
3625 }
3626
3627 void
3628 sigacts_copy(struct sigacts *dest, struct sigacts *src)
3629 {
3630
3631 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest"));
3632 mtx_lock(&src->ps_mtx);
3633 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt));
3634 mtx_unlock(&src->ps_mtx);
3635 }
3636
3637 int
3638 sigacts_shared(struct sigacts *ps)
3639 {
3640
3641 return (ps->ps_refcnt > 1);
3642 }
Cache object: 96ad981f7264e2cb98b3a70c59912c27
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