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kern - Convert aio from zalloc to objcache
[dragonfly.git] / sys / kern / kern_sig.c
blob617e4cfd0aa80ef546e78c6ca94053048d9be683
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 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94
39 * $FreeBSD: src/sys/kern/kern_sig.c,v 1.72.2.17 2003/05/16 16:34:34 obrien Exp $
40 */
41
42 #include "opt_ktrace.h"
43
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
47 #include <sys/sysproto.h>
48 #include <sys/signalvar.h>
49 #include <sys/resourcevar.h>
50 #include <sys/vnode.h>
51 #include <sys/event.h>
52 #include <sys/proc.h>
53 #include <sys/nlookup.h>
54 #include <sys/pioctl.h>
55 #include <sys/systm.h>
56 #include <sys/acct.h>
57 #include <sys/fcntl.h>
58 #include <sys/lock.h>
59 #include <sys/wait.h>
60 #include <sys/ktrace.h>
61 #include <sys/syslog.h>
62 #include <sys/stat.h>
63 #include <sys/sysent.h>
64 #include <sys/sysctl.h>
65 #include <sys/malloc.h>
66 #include <sys/interrupt.h>
67 #include <sys/unistd.h>
68 #include <sys/kern_syscall.h>
69 #include <sys/vkernel.h>
70
71 #include <sys/signal2.h>
72 #include <sys/thread2.h>
73
74 #include <machine/cpu.h>
75 #include <machine/smp.h>
76
77 static int coredump(struct lwp *, int);
78 static char *expand_name(const char *, uid_t, pid_t);
79 static int dokillpg(int sig, int pgid, int all);
80 static int sig_ffs(sigset_t *set);
81 static int sigprop(int sig);
82 static void lwp_signotify(struct lwp *lp);
83 #ifdef SMP
84 static void signotify_remote(void *arg);
85 #endif
86 static int kern_sigtimedwait(sigset_t set, siginfo_t *info,
87 struct timespec *timeout);
88
89 static int filt_sigattach(struct knote *kn);
90 static void filt_sigdetach(struct knote *kn);
91 static int filt_signal(struct knote *kn, long hint);
92
93 struct filterops sig_filtops =
94 { 0, filt_sigattach, filt_sigdetach, filt_signal };
95
96 static int kern_logsigexit = 1;
97 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
98 &kern_logsigexit, 0,
99 "Log processes quitting on abnormal signals to syslog(3)");
100
101 /*
102 * Can process p, with pcred pc, send the signal sig to process q?
103 */
104 #define CANSIGNAL(q, sig) \
105 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \
106 ((sig) == SIGCONT && (q)->p_session == curproc->p_session))
107
108 /*
109 * Policy -- Can real uid ruid with ucred uc send a signal to process q?
110 */
111 #define CANSIGIO(ruid, uc, q) \
112 ((uc)->cr_uid == 0 || \
113 (ruid) == (q)->p_ucred->cr_ruid || \
114 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \
115 (ruid) == (q)->p_ucred->cr_uid || \
116 (uc)->cr_uid == (q)->p_ucred->cr_uid)
117
118 int sugid_coredump;
119 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
120 &sugid_coredump, 0, "Enable coredumping set user/group ID processes");
121
122 static int do_coredump = 1;
123 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
124 &do_coredump, 0, "Enable/Disable coredumps");
125
126 /*
127 * Signal properties and actions.
128 * The array below categorizes the signals and their default actions
129 * according to the following properties:
130 */
131 #define SA_KILL 0x01 /* terminates process by default */
132 #define SA_CORE 0x02 /* ditto and coredumps */
133 #define SA_STOP 0x04 /* suspend process */
134 #define SA_TTYSTOP 0x08 /* ditto, from tty */
135 #define SA_IGNORE 0x10 /* ignore by default */
136 #define SA_CONT 0x20 /* continue if suspended */
137 #define SA_CANTMASK 0x40 /* non-maskable, catchable */
138 #define SA_CKPT 0x80 /* checkpoint process */
139
140
141 static int sigproptbl[NSIG] = {
142 SA_KILL, /* SIGHUP */
143 SA_KILL, /* SIGINT */
144 SA_KILL|SA_CORE, /* SIGQUIT */
145 SA_KILL|SA_CORE, /* SIGILL */
146 SA_KILL|SA_CORE, /* SIGTRAP */
147 SA_KILL|SA_CORE, /* SIGABRT */
148 SA_KILL|SA_CORE, /* SIGEMT */
149 SA_KILL|SA_CORE, /* SIGFPE */
150 SA_KILL, /* SIGKILL */
151 SA_KILL|SA_CORE, /* SIGBUS */
152 SA_KILL|SA_CORE, /* SIGSEGV */
153 SA_KILL|SA_CORE, /* SIGSYS */
154 SA_KILL, /* SIGPIPE */
155 SA_KILL, /* SIGALRM */
156 SA_KILL, /* SIGTERM */
157 SA_IGNORE, /* SIGURG */
158 SA_STOP, /* SIGSTOP */
159 SA_STOP|SA_TTYSTOP, /* SIGTSTP */
160 SA_IGNORE|SA_CONT, /* SIGCONT */
161 SA_IGNORE, /* SIGCHLD */
162 SA_STOP|SA_TTYSTOP, /* SIGTTIN */
163 SA_STOP|SA_TTYSTOP, /* SIGTTOU */
164 SA_IGNORE, /* SIGIO */
165 SA_KILL, /* SIGXCPU */
166 SA_KILL, /* SIGXFSZ */
167 SA_KILL, /* SIGVTALRM */
168 SA_KILL, /* SIGPROF */
169 SA_IGNORE, /* SIGWINCH */
170 SA_IGNORE, /* SIGINFO */
171 SA_KILL, /* SIGUSR1 */
172 SA_KILL, /* SIGUSR2 */
173 SA_IGNORE, /* SIGTHR */
174 SA_CKPT, /* SIGCKPT */
175 SA_KILL|SA_CKPT, /* SIGCKPTEXIT */
176 SA_IGNORE,
177 SA_IGNORE,
178 SA_IGNORE,
179 SA_IGNORE,
180 SA_IGNORE,
181 SA_IGNORE,
182 SA_IGNORE,
183 SA_IGNORE,
184 SA_IGNORE,
185 SA_IGNORE,
186 SA_IGNORE,
187 SA_IGNORE,
188 SA_IGNORE,
189 SA_IGNORE,
190 SA_IGNORE,
191 SA_IGNORE,
192 SA_IGNORE,
193 SA_IGNORE,
194 SA_IGNORE,
195 SA_IGNORE,
196 SA_IGNORE,
197 SA_IGNORE,
198 SA_IGNORE,
199 SA_IGNORE,
200 SA_IGNORE,
201 SA_IGNORE,
202 SA_IGNORE,
203 SA_IGNORE,
204 SA_IGNORE,
205 SA_IGNORE,
206
207 };
208
209 static __inline int
210 sigprop(int sig)
211 {
212
213 if (sig > 0 && sig < NSIG)
214 return (sigproptbl[_SIG_IDX(sig)]);
215 return (0);
216 }
217
218 static __inline int
219 sig_ffs(sigset_t *set)
220 {
221 int i;
222
223 for (i = 0; i < _SIG_WORDS; i++)
224 if (set->__bits[i])
225 return (ffs(set->__bits[i]) + (i * 32));
226 return (0);
227 }
228
229 /*
230 * No requirements.
231 */
232 int
233 kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact)
234 {
235 struct thread *td = curthread;
236 struct proc *p = td->td_proc;
237 struct lwp *lp;
238 struct sigacts *ps = p->p_sigacts;
239
240 if (sig <= 0 || sig > _SIG_MAXSIG)
241 return (EINVAL);
242
243 lwkt_gettoken(&proc_token);
244
245 if (oact) {
246 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
247 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
248 oact->sa_flags = 0;
249 if (SIGISMEMBER(ps->ps_sigonstack, sig))
250 oact->sa_flags |= SA_ONSTACK;
251 if (!SIGISMEMBER(ps->ps_sigintr, sig))
252 oact->sa_flags |= SA_RESTART;
253 if (SIGISMEMBER(ps->ps_sigreset, sig))
254 oact->sa_flags |= SA_RESETHAND;
255 if (SIGISMEMBER(ps->ps_signodefer, sig))
256 oact->sa_flags |= SA_NODEFER;
257 if (SIGISMEMBER(ps->ps_siginfo, sig))
258 oact->sa_flags |= SA_SIGINFO;
259 if (SIGISMEMBER(ps->ps_sigmailbox, sig))
260 oact->sa_flags |= SA_MAILBOX;
261 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDSTOP)
262 oact->sa_flags |= SA_NOCLDSTOP;
263 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDWAIT)
264 oact->sa_flags |= SA_NOCLDWAIT;
265 }
266 if (act) {
267 /*
268 * Check for invalid requests. KILL and STOP cannot be
269 * caught.
270 */
271 if (sig == SIGKILL || sig == SIGSTOP) {
272 if (act->sa_handler != SIG_DFL) {
273 lwkt_reltoken(&proc_token);
274 return (EINVAL);
275 }
276 #if 0
277 /* (not needed, SIG_DFL forces action to occur) */
278 if (act->sa_flags & SA_MAILBOX)
279 return (EINVAL);
280 #endif
281 }
282
283 /*
284 * Change setting atomically.
285 */
286 crit_enter();
287
288 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
289 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
290 if (act->sa_flags & SA_SIGINFO) {
291 ps->ps_sigact[_SIG_IDX(sig)] =
292 (__sighandler_t *)act->sa_sigaction;
293 SIGADDSET(ps->ps_siginfo, sig);
294 } else {
295 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
296 SIGDELSET(ps->ps_siginfo, sig);
297 }
298 if (!(act->sa_flags & SA_RESTART))
299 SIGADDSET(ps->ps_sigintr, sig);
300 else
301 SIGDELSET(ps->ps_sigintr, sig);
302 if (act->sa_flags & SA_ONSTACK)
303 SIGADDSET(ps->ps_sigonstack, sig);
304 else
305 SIGDELSET(ps->ps_sigonstack, sig);
306 if (act->sa_flags & SA_RESETHAND)
307 SIGADDSET(ps->ps_sigreset, sig);
308 else
309 SIGDELSET(ps->ps_sigreset, sig);
310 if (act->sa_flags & SA_NODEFER)
311 SIGADDSET(ps->ps_signodefer, sig);
312 else
313 SIGDELSET(ps->ps_signodefer, sig);
314 if (act->sa_flags & SA_MAILBOX)
315 SIGADDSET(ps->ps_sigmailbox, sig);
316 else
317 SIGDELSET(ps->ps_sigmailbox, sig);
318 if (sig == SIGCHLD) {
319 if (act->sa_flags & SA_NOCLDSTOP)
320 p->p_sigacts->ps_flag |= PS_NOCLDSTOP;
321 else
322 p->p_sigacts->ps_flag &= ~PS_NOCLDSTOP;
323 if (act->sa_flags & SA_NOCLDWAIT) {
324 /*
325 * Paranoia: since SA_NOCLDWAIT is implemented
326 * by reparenting the dying child to PID 1 (and
327 * trust it to reap the zombie), PID 1 itself
328 * is forbidden to set SA_NOCLDWAIT.
329 */
330 if (p->p_pid == 1)
331 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
332 else
333 p->p_sigacts->ps_flag |= PS_NOCLDWAIT;
334 } else {
335 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
336 }
337 }
338 /*
339 * Set bit in p_sigignore for signals that are set to SIG_IGN,
340 * and for signals set to SIG_DFL where the default is to
341 * ignore. However, don't put SIGCONT in p_sigignore, as we
342 * have to restart the process.
343 */
344 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
345 (sigprop(sig) & SA_IGNORE &&
346 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
347 /* never to be seen again */
348 SIGDELSET(p->p_siglist, sig);
349 /*
350 * Remove the signal also from the thread lists.
351 */
352 FOREACH_LWP_IN_PROC(lp, p) {
353 SIGDELSET(lp->lwp_siglist, sig);
354 }
355 if (sig != SIGCONT) {
356 /* easier in ksignal */
357 SIGADDSET(p->p_sigignore, sig);
358 }
359 SIGDELSET(p->p_sigcatch, sig);
360 } else {
361 SIGDELSET(p->p_sigignore, sig);
362 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
363 SIGDELSET(p->p_sigcatch, sig);
364 else
365 SIGADDSET(p->p_sigcatch, sig);
366 }
367
368 crit_exit();
369 }
370 lwkt_reltoken(&proc_token);
371 return (0);
372 }
373
374 int
375 sys_sigaction(struct sigaction_args *uap)
376 {
377 struct sigaction act, oact;
378 struct sigaction *actp, *oactp;
379 int error;
380
381 actp = (uap->act != NULL) ? &act : NULL;
382 oactp = (uap->oact != NULL) ? &oact : NULL;
383 if (actp) {
384 error = copyin(uap->act, actp, sizeof(act));
385 if (error)
386 return (error);
387 }
388 error = kern_sigaction(uap->sig, actp, oactp);
389 if (oactp && !error) {
390 error = copyout(oactp, uap->oact, sizeof(oact));
391 }
392 return (error);
393 }
394
395 /*
396 * Initialize signal state for process 0;
397 * set to ignore signals that are ignored by default.
398 */
399 void
400 siginit(struct proc *p)
401 {
402 int i;
403
404 for (i = 1; i <= NSIG; i++)
405 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
406 SIGADDSET(p->p_sigignore, i);
407 }
408
409 /*
410 * Reset signals for an exec of the specified process.
411 */
412 void
413 execsigs(struct proc *p)
414 {
415 struct sigacts *ps = p->p_sigacts;
416 struct lwp *lp;
417 int sig;
418
419 lp = ONLY_LWP_IN_PROC(p);
420
421 /*
422 * Reset caught signals. Held signals remain held
423 * through p_sigmask (unless they were caught,
424 * and are now ignored by default).
425 */
426 while (SIGNOTEMPTY(p->p_sigcatch)) {
427 sig = sig_ffs(&p->p_sigcatch);
428 SIGDELSET(p->p_sigcatch, sig);
429 if (sigprop(sig) & SA_IGNORE) {
430 if (sig != SIGCONT)
431 SIGADDSET(p->p_sigignore, sig);
432 SIGDELSET(p->p_siglist, sig);
433 SIGDELSET(lp->lwp_siglist, sig);
434 }
435 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
436 }
437
438 /*
439 * Reset stack state to the user stack.
440 * Clear set of signals caught on the signal stack.
441 */
442 lp->lwp_sigstk.ss_flags = SS_DISABLE;
443 lp->lwp_sigstk.ss_size = 0;
444 lp->lwp_sigstk.ss_sp = 0;
445 lp->lwp_flag &= ~LWP_ALTSTACK;
446 /*
447 * Reset no zombies if child dies flag as Solaris does.
448 */
449 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
450 }
451
452 /*
453 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
454 *
455 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
456 * p == curproc.
457 */
458 int
459 kern_sigprocmask(int how, sigset_t *set, sigset_t *oset)
460 {
461 struct thread *td = curthread;
462 struct lwp *lp = td->td_lwp;
463 int error;
464
465 lwkt_gettoken(&proc_token);
466
467 if (oset != NULL)
468 *oset = lp->lwp_sigmask;
469
470 error = 0;
471 if (set != NULL) {
472 switch (how) {
473 case SIG_BLOCK:
474 SIG_CANTMASK(*set);
475 SIGSETOR(lp->lwp_sigmask, *set);
476 break;
477 case SIG_UNBLOCK:
478 SIGSETNAND(lp->lwp_sigmask, *set);
479 break;
480 case SIG_SETMASK:
481 SIG_CANTMASK(*set);
482 lp->lwp_sigmask = *set;
483 break;
484 default:
485 error = EINVAL;
486 break;
487 }
488 }
489
490 lwkt_reltoken(&proc_token);
491
492 return (error);
493 }
494
495 /*
496 * sigprocmask()
497 *
498 * MPSAFE
499 */
500 int
501 sys_sigprocmask(struct sigprocmask_args *uap)
502 {
503 sigset_t set, oset;
504 sigset_t *setp, *osetp;
505 int error;
506
507 setp = (uap->set != NULL) ? &set : NULL;
508 osetp = (uap->oset != NULL) ? &oset : NULL;
509 if (setp) {
510 error = copyin(uap->set, setp, sizeof(set));
511 if (error)
512 return (error);
513 }
514 error = kern_sigprocmask(uap->how, setp, osetp);
515 if (osetp && !error) {
516 error = copyout(osetp, uap->oset, sizeof(oset));
517 }
518 return (error);
519 }
520
521 /*
522 * MPSAFE
523 */
524 int
525 kern_sigpending(struct __sigset *set)
526 {
527 struct lwp *lp = curthread->td_lwp;
528
529 *set = lwp_sigpend(lp);
530
531 return (0);
532 }
533
534 /*
535 * MPSAFE
536 */
537 int
538 sys_sigpending(struct sigpending_args *uap)
539 {
540 sigset_t set;
541 int error;
542
543 error = kern_sigpending(&set);
544
545 if (error == 0)
546 error = copyout(&set, uap->set, sizeof(set));
547 return (error);
548 }
549
550 /*
551 * Suspend process until signal, providing mask to be set
552 * in the meantime.
553 *
554 * MPSAFE
555 */
556 int
557 kern_sigsuspend(struct __sigset *set)
558 {
559 struct thread *td = curthread;
560 struct lwp *lp = td->td_lwp;
561 struct proc *p = td->td_proc;
562 struct sigacts *ps = p->p_sigacts;
563
564 /*
565 * When returning from sigsuspend, we want
566 * the old mask to be restored after the
567 * signal handler has finished. Thus, we
568 * save it here and mark the sigacts structure
569 * to indicate this.
570 */
571 lp->lwp_oldsigmask = lp->lwp_sigmask;
572 lp->lwp_flag |= LWP_OLDMASK;
573
574 SIG_CANTMASK(*set);
575 lp->lwp_sigmask = *set;
576 while (tsleep(ps, PCATCH, "pause", 0) == 0)
577 /* void */;
578 /* always return EINTR rather than ERESTART... */
579 return (EINTR);
580 }
581
582 /*
583 * Note nonstandard calling convention: libc stub passes mask, not
584 * pointer, to save a copyin.
585 *
586 * MPSAFE
587 */
588 int
589 sys_sigsuspend(struct sigsuspend_args *uap)
590 {
591 sigset_t mask;
592 int error;
593
594 error = copyin(uap->sigmask, &mask, sizeof(mask));
595 if (error)
596 return (error);
597
598 error = kern_sigsuspend(&mask);
599
600 return (error);
601 }
602
603 /*
604 * MPSAFE
605 */
606 int
607 kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss)
608 {
609 struct thread *td = curthread;
610 struct lwp *lp = td->td_lwp;
611 struct proc *p = td->td_proc;
612
613 if ((lp->lwp_flag & LWP_ALTSTACK) == 0)
614 lp->lwp_sigstk.ss_flags |= SS_DISABLE;
615
616 if (oss)
617 *oss = lp->lwp_sigstk;
618
619 if (ss) {
620 if (ss->ss_flags & SS_DISABLE) {
621 if (lp->lwp_sigstk.ss_flags & SS_ONSTACK)
622 return (EINVAL);
623 lp->lwp_flag &= ~LWP_ALTSTACK;
624 lp->lwp_sigstk.ss_flags = ss->ss_flags;
625 } else {
626 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
627 return (ENOMEM);
628 lp->lwp_flag |= LWP_ALTSTACK;
629 lp->lwp_sigstk = *ss;
630 }
631 }
632
633 return (0);
634 }
635
636 /*
637 * MPSAFE
638 */
639 int
640 sys_sigaltstack(struct sigaltstack_args *uap)
641 {
642 stack_t ss, oss;
643 int error;
644
645 if (uap->ss) {
646 error = copyin(uap->ss, &ss, sizeof(ss));
647 if (error)
648 return (error);
649 }
650
651 error = kern_sigaltstack(uap->ss ? &ss : NULL,
652 uap->oss ? &oss : NULL);
653
654 if (error == 0 && uap->oss)
655 error = copyout(&oss, uap->oss, sizeof(*uap->oss));
656 return (error);
657 }
658
659 /*
660 * Common code for kill process group/broadcast kill.
661 * cp is calling process.
662 */
663 struct killpg_info {
664 int nfound;
665 int sig;
666 };
667
668 static int killpg_all_callback(struct proc *p, void *data);
669
670 static int
671 dokillpg(int sig, int pgid, int all)
672 {
673 struct killpg_info info;
674 struct proc *cp = curproc;
675 struct proc *p;
676 struct pgrp *pgrp;
677
678 info.nfound = 0;
679 info.sig = sig;
680
681 if (all) {
682 /*
683 * broadcast
684 */
685 allproc_scan(killpg_all_callback, &info);
686 } else {
687 if (pgid == 0) {
688 /*
689 * zero pgid means send to my process group.
690 */
691 pgrp = cp->p_pgrp;
692 } else {
693 pgrp = pgfind(pgid);
694 if (pgrp == NULL)
695 return (ESRCH);
696 }
697 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
698 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
699 if (p->p_pid <= 1 ||
700 p->p_stat == SZOMB ||
701 (p->p_flag & P_SYSTEM) ||
702 !CANSIGNAL(p, sig)) {
703 continue;
704 }
705 ++info.nfound;
706 if (sig)
707 ksignal(p, sig);
708 }
709 lockmgr(&pgrp->pg_lock, LK_RELEASE);
710 }
711 return (info.nfound ? 0 : ESRCH);
712 }
713
714 static int
715 killpg_all_callback(struct proc *p, void *data)
716 {
717 struct killpg_info *info = data;
718
719 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) ||
720 p == curproc || !CANSIGNAL(p, info->sig)) {
721 return (0);
722 }
723 ++info->nfound;
724 if (info->sig)
725 ksignal(p, info->sig);
726 return(0);
727 }
728
729 /*
730 * Send a general signal to a process or LWPs within that process. Note
731 * that new signals cannot be sent if a process is exiting.
732 *
733 * No requirements.
734 */
735 int
736 kern_kill(int sig, pid_t pid, lwpid_t tid)
737 {
738 int t;
739
740 if ((u_int)sig > _SIG_MAXSIG)
741 return (EINVAL);
742
743 lwkt_gettoken(&proc_token);
744
745 if (pid > 0) {
746 struct proc *p;
747 struct lwp *lp = NULL;
748
749 /* kill single process */
750 if ((p = pfind(pid)) == NULL) {
751 lwkt_reltoken(&proc_token);
752 return (ESRCH);
753 }
754 if (!CANSIGNAL(p, sig)) {
755 lwkt_reltoken(&proc_token);
756 return (EPERM);
757 }
758
759 /*
760 * NOP if the process is exiting. Note that lwpsignal() is
761 * called directly with P_WEXIT set to kill individual LWPs
762 * during exit, which is allowed.
763 */
764 if (p->p_flag & P_WEXIT) {
765 lwkt_reltoken(&proc_token);
766 return (0);
767 }
768 if (tid != -1) {
769 lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, tid);
770 if (lp == NULL) {
771 lwkt_reltoken(&proc_token);
772 return (ESRCH);
773 }
774 }
775 if (sig)
776 lwpsignal(p, lp, sig);
777 lwkt_reltoken(&proc_token);
778 return (0);
779 }
780 /*
781 * If we come here, pid is a special broadcast pid.
782 * This doesn't mix with a tid.
783 */
784 if (tid != -1) {
785 lwkt_reltoken(&proc_token);
786 return (EINVAL);
787 }
788 switch (pid) {
789 case -1: /* broadcast signal */
790 t = (dokillpg(sig, 0, 1));
791 break;
792 case 0: /* signal own process group */
793 t = (dokillpg(sig, 0, 0));
794 break;
795 default: /* negative explicit process group */
796 t = (dokillpg(sig, -pid, 0));
797 break;
798 }
799 lwkt_reltoken(&proc_token);
800 return t;
801 }
802
803 int
804 sys_kill(struct kill_args *uap)
805 {
806 int error;
807
808 error = kern_kill(uap->signum, uap->pid, -1);
809 return (error);
810 }
811
812 int
813 sys_lwp_kill(struct lwp_kill_args *uap)
814 {
815 int error;
816 pid_t pid = uap->pid;
817
818 /*
819 * A tid is mandatory for lwp_kill(), otherwise
820 * you could simply use kill().
821 */
822 if (uap->tid == -1)
823 return (EINVAL);
824
825 /*
826 * To save on a getpid() function call for intra-process
827 * signals, pid == -1 means current process.
828 */
829 if (pid == -1)
830 pid = curproc->p_pid;
831
832 error = kern_kill(uap->signum, pid, uap->tid);
833 return (error);
834 }
835
836 /*
837 * Send a signal to a process group.
838 */
839 void
840 gsignal(int pgid, int sig)
841 {
842 struct pgrp *pgrp;
843
844 if (pgid && (pgrp = pgfind(pgid)))
845 pgsignal(pgrp, sig, 0);
846 }
847
848 /*
849 * Send a signal to a process group. If checktty is 1,
850 * limit to members which have a controlling terminal.
851 *
852 * pg_lock interlocks against a fork that might be in progress, to
853 * ensure that the new child process picks up the signal.
854 */
855 void
856 pgsignal(struct pgrp *pgrp, int sig, int checkctty)
857 {
858 struct proc *p;
859
860 if (pgrp) {
861 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
862 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
863 if (checkctty == 0 || p->p_flag & P_CONTROLT)
864 ksignal(p, sig);
865 }
866 lockmgr(&pgrp->pg_lock, LK_RELEASE);
867 }
868 }
869
870 /*
871 * Send a signal caused by a trap to the current lwp. If it will be caught
872 * immediately, deliver it with correct code. Otherwise, post it normally.
873 *
874 * These signals may ONLY be delivered to the specified lwp and may never
875 * be delivered to the process generically.
876 */
877 void
878 trapsignal(struct lwp *lp, int sig, u_long code)
879 {
880 struct proc *p = lp->lwp_proc;
881 struct sigacts *ps = p->p_sigacts;
882
883 /*
884 * If we are a virtual kernel running an emulated user process
885 * context, switch back to the virtual kernel context before
886 * trying to post the signal.
887 */
888 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
889 struct trapframe *tf = lp->lwp_md.md_regs;
890 tf->tf_trapno = 0;
891 vkernel_trap(lp, tf);
892 }
893
894
895 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
896 !SIGISMEMBER(lp->lwp_sigmask, sig)) {
897 lp->lwp_ru.ru_nsignals++;
898 #ifdef KTRACE
899 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
900 ktrpsig(lp, sig, ps->ps_sigact[_SIG_IDX(sig)],
901 &lp->lwp_sigmask, code);
902 #endif
903 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
904 &lp->lwp_sigmask, code);
905 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
906 if (!SIGISMEMBER(ps->ps_signodefer, sig))
907 SIGADDSET(lp->lwp_sigmask, sig);
908 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
909 /*
910 * See kern_sigaction() for origin of this code.
911 */
912 SIGDELSET(p->p_sigcatch, sig);
913 if (sig != SIGCONT &&
914 sigprop(sig) & SA_IGNORE)
915 SIGADDSET(p->p_sigignore, sig);
916 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
917 }
918 } else {
919 lp->lwp_code = code; /* XXX for core dump/debugger */
920 lp->lwp_sig = sig; /* XXX to verify code */
921 lwpsignal(p, lp, sig);
922 }
923 }
924
925 /*
926 * Find a suitable lwp to deliver the signal to.
927 *
928 * Returns NULL if all lwps hold the signal blocked.
929 */
930 static struct lwp *
931 find_lwp_for_signal(struct proc *p, int sig)
932 {
933 struct lwp *lp;
934 struct lwp *run, *sleep, *stop;
935
936 /*
937 * If the running/preempted thread belongs to the proc to which
938 * the signal is being delivered and this thread does not block
939 * the signal, then we can avoid a context switch by delivering
940 * the signal to this thread, because it will return to userland
941 * soon anyways.
942 */
943 lp = lwkt_preempted_proc();
944 if (lp != NULL && lp->lwp_proc == p && !SIGISMEMBER(lp->lwp_sigmask, sig))
945 return (lp);
946
947 run = sleep = stop = NULL;
948 FOREACH_LWP_IN_PROC(lp, p) {
949 /*
950 * If the signal is being blocked by the lwp, then this
951 * lwp is not eligible for receiving the signal.
952 */
953 if (SIGISMEMBER(lp->lwp_sigmask, sig))
954 continue;
955
956 switch (lp->lwp_stat) {
957 case LSRUN:
958 run = lp;
959 break;
960
961 case LSSTOP:
962 stop = lp;
963 break;
964
965 case LSSLEEP:
966 if (lp->lwp_flag & LWP_SINTR)
967 sleep = lp;
968 break;
969 }
970 }
971
972 if (run != NULL)
973 return (run);
974 else if (sleep != NULL)
975 return (sleep);
976 else
977 return (stop);
978 }
979
980 /*
981 * Send the signal to the process. If the signal has an action, the action
982 * is usually performed by the target process rather than the caller; we add
983 * the signal to the set of pending signals for the process.
984 *
985 * Exceptions:
986 * o When a stop signal is sent to a sleeping process that takes the
987 * default action, the process is stopped without awakening it.
988 * o SIGCONT restarts stopped processes (or puts them back to sleep)
989 * regardless of the signal action (eg, blocked or ignored).
990 *
991 * Other ignored signals are discarded immediately.
992 *
993 * No requirements.
994 */
995 void
996 ksignal(struct proc *p, int sig)
997 {
998 lwpsignal(p, NULL, sig);
999 }
1000
1001 /*
1002 * The core for ksignal. lp may be NULL, then a suitable thread
1003 * will be chosen. If not, lp MUST be a member of p.
1004 *
1005 * No requirements.
1006 */
1007 void
1008 lwpsignal(struct proc *p, struct lwp *lp, int sig)
1009 {
1010 int prop;
1011 sig_t action;
1012
1013 if (sig > _SIG_MAXSIG || sig <= 0) {
1014 kprintf("lwpsignal: signal %d\n", sig);
1015 panic("lwpsignal signal number");
1016 }
1017
1018 KKASSERT(lp == NULL || lp->lwp_proc == p);
1019
1020 lwkt_gettoken(&proc_token);
1021
1022 prop = sigprop(sig);
1023
1024 /*
1025 * If proc is traced, always give parent a chance;
1026 * if signal event is tracked by procfs, give *that*
1027 * a chance, as well.
1028 */
1029 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) {
1030 action = SIG_DFL;
1031 } else {
1032 /*
1033 * Do not try to deliver signals to an exiting lwp. Note
1034 * that we must still deliver the signal if P_WEXIT is set
1035 * in the process flags.
1036 */
1037 if (lp && (lp->lwp_flag & LWP_WEXIT)) {
1038 lwkt_reltoken(&proc_token);
1039 return;
1040 }
1041
1042 /*
1043 * If the signal is being ignored, then we forget about
1044 * it immediately. NOTE: We don't set SIGCONT in p_sigignore,
1045 * and if it is set to SIG_IGN, action will be SIG_DFL here.
1046 */
1047 if (SIGISMEMBER(p->p_sigignore, sig)) {
1048 lwkt_reltoken(&proc_token);
1049 return;
1050 }
1051 if (SIGISMEMBER(p->p_sigcatch, sig))
1052 action = SIG_CATCH;
1053 else
1054 action = SIG_DFL;
1055 }
1056
1057 /*
1058 * If continuing, clear any pending STOP signals.
1059 */
1060 if (prop & SA_CONT)
1061 SIG_STOPSIGMASK(p->p_siglist);
1062
1063 if (prop & SA_STOP) {
1064 /*
1065 * If sending a tty stop signal to a member of an orphaned
1066 * process group, discard the signal here if the action
1067 * is default; don't stop the process below if sleeping,
1068 * and don't clear any pending SIGCONT.
1069 */
1070 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
1071 action == SIG_DFL) {
1072 lwkt_reltoken(&proc_token);
1073 return;
1074 }
1075 SIG_CONTSIGMASK(p->p_siglist);
1076 p->p_flag &= ~P_CONTINUED;
1077 }
1078
1079 crit_enter();
1080
1081 if (p->p_stat == SSTOP) {
1082 /*
1083 * Nobody can handle this signal, add it to the lwp or
1084 * process pending list
1085 */
1086 if (lp)
1087 SIGADDSET(lp->lwp_siglist, sig);
1088 else
1089 SIGADDSET(p->p_siglist, sig);
1090
1091 /*
1092 * If the process is stopped and is being traced, then no
1093 * further action is necessary.
1094 */
1095 if (p->p_flag & P_TRACED)
1096 goto out;
1097
1098 /*
1099 * If the process is stopped and receives a KILL signal,
1100 * make the process runnable.
1101 */
1102 if (sig == SIGKILL) {
1103 proc_unstop(p);
1104 goto active_process;
1105 }
1106
1107 /*
1108 * If the process is stopped and receives a CONT signal,
1109 * then try to make the process runnable again.
1110 */
1111 if (prop & SA_CONT) {
1112 /*
1113 * If SIGCONT is default (or ignored), we continue the
1114 * process but don't leave the signal in p_siglist, as
1115 * it has no further action. If SIGCONT is held, we
1116 * continue the process and leave the signal in
1117 * p_siglist. If the process catches SIGCONT, let it
1118 * handle the signal itself.
1119 */
1120 /* XXX what if the signal is being held blocked? */
1121 p->p_flag |= P_CONTINUED;
1122 wakeup(p->p_pptr);
1123 if (action == SIG_DFL)
1124 SIGDELSET(p->p_siglist, sig);
1125 proc_unstop(p);
1126 if (action == SIG_CATCH)
1127 goto active_process;
1128 goto out;
1129 }
1130
1131 /*
1132 * If the process is stopped and receives another STOP
1133 * signal, we do not need to stop it again. If we did
1134 * the shell could get confused.
1135 *
1136 * However, if the current/preempted lwp is part of the
1137 * process receiving the signal, we need to keep it,
1138 * so that this lwp can stop in issignal() later, as
1139 * we don't want to wait until it reaches userret!
1140 */
1141 if (prop & SA_STOP) {
1142 if (lwkt_preempted_proc() == NULL ||
1143 lwkt_preempted_proc()->lwp_proc != p)
1144 SIGDELSET(p->p_siglist, sig);
1145 }
1146
1147 /*
1148 * Otherwise the process is stopped and it received some
1149 * signal, which does not change its stopped state.
1150 *
1151 * We have to select one thread to set LWP_BREAKTSLEEP,
1152 * so that the current signal will break the sleep
1153 * as soon as a SA_CONT signal will unstop the process.
1154 */
1155 if (lp == NULL)
1156 lp = find_lwp_for_signal(p, sig);
1157 if (lp != NULL &&
1158 (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP))
1159 lp->lwp_flag |= LWP_BREAKTSLEEP;
1160 goto out;
1161
1162 /* NOTREACHED */
1163 }
1164 /* else not stopped */
1165 active_process:
1166
1167 /*
1168 * Never deliver a lwp-specific signal to a random lwp.
1169 */
1170 if (lp == NULL) {
1171 lp = find_lwp_for_signal(p, sig);
1172 if (lp && SIGISMEMBER(lp->lwp_sigmask, sig))
1173 lp = NULL;
1174 }
1175
1176 /*
1177 * Deliver to the process generically if (1) the signal is being
1178 * sent to any thread or (2) we could not find a thread to deliver
1179 * it to.
1180 */
1181 if (lp == NULL) {
1182 SIGADDSET(p->p_siglist, sig);
1183 goto out;
1184 }
1185
1186 /*
1187 * Deliver to a specific LWP whether it masks it or not. It will
1188 * not be dispatched if masked but we must still deliver it.
1189 */
1190 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
1191 (p->p_flag & P_TRACED) == 0) {
1192 p->p_nice = NZERO;
1193 }
1194
1195 /*
1196 * If the process receives a STOP signal which indeed needs to
1197 * stop the process, do so. If the process chose to catch the
1198 * signal, it will be treated like any other signal.
1199 */
1200 if ((prop & SA_STOP) && action == SIG_DFL) {
1201 /*
1202 * If a child holding parent blocked, stopping
1203 * could cause deadlock. Take no action at this
1204 * time.
1205 */
1206 if (p->p_flag & P_PPWAIT) {
1207 SIGADDSET(p->p_siglist, sig);
1208 goto out;
1209 }
1210
1211 /*
1212 * Do not actually try to manipulate the process, but simply
1213 * stop it. Lwps will stop as soon as they safely can.
1214 */
1215 p->p_xstat = sig;
1216 proc_stop(p);
1217 goto out;
1218 }
1219
1220 /*
1221 * If it is a CONT signal with default action, just ignore it.
1222 */
1223 if ((prop & SA_CONT) && action == SIG_DFL)
1224 goto out;
1225
1226 /*
1227 * Mark signal pending at this specific thread.
1228 */
1229 SIGADDSET(lp->lwp_siglist, sig);
1230
1231 lwp_signotify(lp);
1232
1233 out:
1234 lwkt_reltoken(&proc_token);
1235 crit_exit();
1236 }
1237
1238 /*
1239 * proc_token must be held
1240 */
1241 static void
1242 lwp_signotify(struct lwp *lp)
1243 {
1244 ASSERT_LWKT_TOKEN_HELD(&proc_token);
1245 crit_enter();
1246
1247 if (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP) {
1248 /*
1249 * Thread is in tsleep.
1250 */
1251
1252 /*
1253 * If the thread is sleeping uninterruptibly
1254 * we can't interrupt the sleep... the signal will
1255 * be noticed when the lwp returns through
1256 * trap() or syscall().
1257 *
1258 * Otherwise the signal can interrupt the sleep.
1259 *
1260 * If the process is traced, the lwp will handle the
1261 * tracing in issignal() when it returns to userland.
1262 */
1263 if (lp->lwp_flag & LWP_SINTR) {
1264 /*
1265 * Make runnable and break out of any tsleep as well.
1266 */
1267 lp->lwp_flag |= LWP_BREAKTSLEEP;
1268 setrunnable(lp);
1269 }
1270 } else {
1271 /*
1272 * Otherwise the thread is running
1273 *
1274 * LSRUN does nothing with the signal, other than kicking
1275 * ourselves if we are running.
1276 * SZOMB and SIDL mean that it will either never be noticed,
1277 * or noticed very soon.
1278 *
1279 * Note that lwp_thread may be NULL or may not be completely
1280 * initialized if the process is in the SIDL or SZOMB state.
1281 *
1282 * For SMP we may have to forward the request to another cpu.
1283 * YYY the MP lock prevents the target process from moving
1284 * to another cpu, see kern/kern_switch.c
1285 *
1286 * If the target thread is waiting on its message port,
1287 * wakeup the target thread so it can check (or ignore)
1288 * the new signal. YYY needs cleanup.
1289 */
1290 if (lp == lwkt_preempted_proc()) {
1291 signotify();
1292 } else if (lp->lwp_stat == LSRUN) {
1293 struct thread *td = lp->lwp_thread;
1294 struct proc *p __debugvar = lp->lwp_proc;
1295
1296 KASSERT(td != NULL,
1297 ("pid %d/%d NULL lwp_thread stat %d flags %08x/%08x",
1298 p->p_pid, lp->lwp_tid, lp->lwp_stat,
1299 p->p_flag, lp->lwp_flag));
1300
1301 /*
1302 * To prevent a MP race with TDF_SINTR we must
1303 * schedule the thread on the correct cpu.
1304 */
1305 #ifdef SMP
1306 if (td->td_gd != mycpu) {
1307 LWPHOLD(lp);
1308 lwkt_send_ipiq(td->td_gd, signotify_remote, lp);
1309 } else
1310 #endif
1311 if (td->td_flags & TDF_SINTR)
1312 lwkt_schedule(td);
1313 }
1314 }
1315 crit_exit();
1316 }
1317
1318 #ifdef SMP
1319
1320 /*
1321 * This function is called via an IPI. We will be in a critical section but
1322 * the MP lock will NOT be held. The passed lp will be held.
1323 *
1324 * We must essentially repeat the code at the end of lwp_signotify(),
1325 * in particular rechecking all races. If we are still not on the
1326 * correct cpu we leave the lwp ref intact and continue the chase.
1327 *
1328 * XXX this may still not be entirely correct, since we are checking
1329 * lwp_stat asynchronously.
1330 */
1331 static void
1332 signotify_remote(void *arg)
1333 {
1334 struct lwp *lp = arg;
1335 thread_t td;
1336
1337 if (lp == lwkt_preempted_proc()) {
1338 signotify();
1339 } else if (lp->lwp_stat == LSRUN) {
1340 /*
1341 * To prevent a MP race with TDF_SINTR we must
1342 * schedule the thread on the correct cpu.
1343 */
1344 td = lp->lwp_thread;
1345 if (td->td_gd != mycpu) {
1346 lwkt_send_ipiq(td->td_gd, signotify_remote, lp);
1347 return;
1348 /* NOT REACHED */
1349 }
1350 if (td->td_flags & TDF_SINTR)
1351 lwkt_schedule(td);
1352 }
1353 LWPRELE(lp);
1354 }
1355
1356 #endif
1357
1358 /*
1359 * Caller must hold proc_token
1360 */
1361 void
1362 proc_stop(struct proc *p)
1363 {
1364 struct lwp *lp;
1365
1366 ASSERT_LWKT_TOKEN_HELD(&proc_token);
1367 crit_enter();
1368
1369 /* If somebody raced us, be happy with it */
1370 if (p->p_stat == SSTOP || p->p_stat == SZOMB) {
1371 crit_exit();
1372 return;
1373 }
1374 p->p_stat = SSTOP;
1375
1376 FOREACH_LWP_IN_PROC(lp, p) {
1377 switch (lp->lwp_stat) {
1378 case LSSTOP:
1379 /*
1380 * Do nothing, we are already counted in
1381 * p_nstopped.
1382 */
1383 break;
1384
1385 case LSSLEEP:
1386 /*
1387 * We're sleeping, but we will stop before
1388 * returning to userspace, so count us
1389 * as stopped as well. We set LWP_WSTOP
1390 * to signal the lwp that it should not
1391 * increase p_nstopped when reaching tstop().
1392 */
1393 if ((lp->lwp_flag & LWP_WSTOP) == 0) {
1394 lp->lwp_flag |= LWP_WSTOP;
1395 ++p->p_nstopped;
1396 }
1397 break;
1398
1399 case LSRUN:
1400 /*
1401 * We might notify ourself, but that's not
1402 * a problem.
1403 */
1404 lwp_signotify(lp);
1405 break;
1406 }
1407 }
1408
1409 if (p->p_nstopped == p->p_nthreads) {
1410 p->p_flag &= ~P_WAITED;
1411 wakeup(p->p_pptr);
1412 if ((p->p_pptr->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1413 ksignal(p->p_pptr, SIGCHLD);
1414 }
1415 crit_exit();
1416 }
1417
1418 /*
1419 * Caller must hold proc_token
1420 */
1421 void
1422 proc_unstop(struct proc *p)
1423 {
1424 struct lwp *lp;
1425
1426 ASSERT_LWKT_TOKEN_HELD(&proc_token);
1427 crit_enter();
1428
1429 if (p->p_stat != SSTOP) {
1430 crit_exit();
1431 return;
1432 }
1433
1434 p->p_stat = SACTIVE;
1435
1436 FOREACH_LWP_IN_PROC(lp, p) {
1437 switch (lp->lwp_stat) {
1438 case LSRUN:
1439 /*
1440 * Uh? Not stopped? Well, I guess that's okay.
1441 */
1442 if (bootverbose)
1443 kprintf("proc_unstop: lwp %d/%d not sleeping\n",
1444 p->p_pid, lp->lwp_tid);
1445 break;
1446
1447 case LSSLEEP:
1448 /*
1449 * Still sleeping. Don't bother waking it up.
1450 * However, if this thread was counted as
1451 * stopped, undo this.
1452 *
1453 * Nevertheless we call setrunnable() so that it
1454 * will wake up in case a signal or timeout arrived
1455 * in the meantime.
1456 */
1457 if (lp->lwp_flag & LWP_WSTOP) {
1458 lp->lwp_flag &= ~LWP_WSTOP;
1459 --p->p_nstopped;
1460 } else {
1461 if (bootverbose)
1462 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n",
1463 p->p_pid, lp->lwp_tid);
1464 }
1465 /* FALLTHROUGH */
1466
1467 case LSSTOP:
1468 setrunnable(lp);
1469 break;
1470
1471 }
1472 }
1473 crit_exit();
1474 }
1475
1476 /*
1477 * No requirements.
1478 */
1479 static int
1480 kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout)
1481 {
1482 sigset_t savedmask, set;
1483 struct proc *p = curproc;
1484 struct lwp *lp = curthread->td_lwp;
1485 int error, sig, hz, timevalid = 0;
1486 struct timespec rts, ets, ts;
1487 struct timeval tv;
1488
1489 lwkt_gettoken(&proc_token);
1490
1491 error = 0;
1492 sig = 0;
1493 ets.tv_sec = 0; /* silence compiler warning */
1494 ets.tv_nsec = 0; /* silence compiler warning */
1495 SIG_CANTMASK(waitset);
1496 savedmask = lp->lwp_sigmask;
1497
1498 if (timeout) {
1499 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 &&
1500 timeout->tv_nsec < 1000000000) {
1501 timevalid = 1;
1502 getnanouptime(&rts);
1503 ets = rts;
1504 timespecadd(&ets, timeout);
1505 }
1506 }
1507
1508 for (;;) {
1509 set = lwp_sigpend(lp);
1510 SIGSETAND(set, waitset);
1511 if ((sig = sig_ffs(&set)) != 0) {
1512 SIGFILLSET(lp->lwp_sigmask);
1513 SIGDELSET(lp->lwp_sigmask, sig);
1514 SIG_CANTMASK(lp->lwp_sigmask);
1515 sig = issignal(lp, 1);
1516 /*
1517 * It may be a STOP signal, in the case, issignal
1518 * returns 0, because we may stop there, and new
1519 * signal can come in, we should restart if we got
1520 * nothing.
1521 */
1522 if (sig == 0)
1523 continue;
1524 else
1525 break;
1526 }
1527
1528 /*
1529 * Previous checking got nothing, and we retried but still
1530 * got nothing, we should return the error status.
1531 */
1532 if (error)
1533 break;
1534
1535 /*
1536 * POSIX says this must be checked after looking for pending
1537 * signals.
1538 */
1539 if (timeout) {
1540 if (timevalid == 0) {
1541 error = EINVAL;
1542 break;
1543 }
1544 getnanouptime(&rts);
1545 if (timespeccmp(&rts, &ets, >=)) {
1546 error = EAGAIN;
1547 break;
1548 }
1549 ts = ets;
1550 timespecsub(&ts, &rts);
1551 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1552 hz = tvtohz_high(&tv);
1553 } else
1554 hz = 0;
1555
1556 lp->lwp_sigmask = savedmask;
1557 SIGSETNAND(lp->lwp_sigmask, waitset);
1558 /*
1559 * We won't ever be woken up. Instead, our sleep will
1560 * be broken in lwpsignal().
1561 */
1562 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz);
1563 if (timeout) {
1564 if (error == ERESTART) {
1565 /* can not restart a timeout wait. */
1566 error = EINTR;
1567 } else if (error == EAGAIN) {
1568 /* will calculate timeout by ourself. */
1569 error = 0;
1570 }
1571 }
1572 /* Retry ... */
1573 }
1574
1575 lp->lwp_sigmask = savedmask;
1576 if (sig) {
1577 error = 0;
1578 bzero(info, sizeof(*info));
1579 info->si_signo = sig;
1580 lwp_delsig(lp, sig); /* take the signal! */
1581
1582 if (sig == SIGKILL) {
1583 lwkt_reltoken(&proc_token);
1584 sigexit(lp, sig);
1585 /* NOT REACHED */
1586 }
1587 }
1588
1589 lwkt_reltoken(&proc_token);
1590
1591 return (error);
1592 }
1593
1594 /*
1595 * MPALMOSTSAFE
1596 */
1597 int
1598 sys_sigtimedwait(struct sigtimedwait_args *uap)
1599 {
1600 struct timespec ts;
1601 struct timespec *timeout;
1602 sigset_t set;
1603 siginfo_t info;
1604 int error;
1605
1606 if (uap->timeout) {
1607 error = copyin(uap->timeout, &ts, sizeof(ts));
1608 if (error)
1609 return (error);
1610 timeout = &ts;
1611 } else {
1612 timeout = NULL;
1613 }
1614 error = copyin(uap->set, &set, sizeof(set));
1615 if (error)
1616 return (error);
1617 error = kern_sigtimedwait(set, &info, timeout);
1618 if (error)
1619 return (error);
1620 if (uap->info)
1621 error = copyout(&info, uap->info, sizeof(info));
1622 /* Repost if we got an error. */
1623 /*
1624 * XXX lwp
1625 *
1626 * This could transform a thread-specific signal to another
1627 * thread / process pending signal.
1628 */
1629 if (error) {
1630 ksignal(curproc, info.si_signo);
1631 } else {
1632 uap->sysmsg_result = info.si_signo;
1633 }
1634 return (error);
1635 }
1636
1637 /*
1638 * MPALMOSTSAFE
1639 */
1640 int
1641 sys_sigwaitinfo(struct sigwaitinfo_args *uap)
1642 {
1643 siginfo_t info;
1644 sigset_t set;
1645 int error;
1646
1647 error = copyin(uap->set, &set, sizeof(set));
1648 if (error)
1649 return (error);
1650 error = kern_sigtimedwait(set, &info, NULL);
1651 if (error)
1652 return (error);
1653 if (uap->info)
1654 error = copyout(&info, uap->info, sizeof(info));
1655 /* Repost if we got an error. */
1656 /*
1657 * XXX lwp
1658 *
1659 * This could transform a thread-specific signal to another
1660 * thread / process pending signal.
1661 */
1662 if (error) {
1663 ksignal(curproc, info.si_signo);
1664 } else {
1665 uap->sysmsg_result = info.si_signo;
1666 }
1667 return (error);
1668 }
1669
1670 /*
1671 * If the current process has received a signal that would interrupt a
1672 * system call, return EINTR or ERESTART as appropriate.
1673 */
1674 int
1675 iscaught(struct lwp *lp)
1676 {
1677 struct proc *p = lp->lwp_proc;
1678 int sig;
1679
1680 if (p) {
1681 if ((sig = CURSIG(lp)) != 0) {
1682 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1683 return (EINTR);
1684 return (ERESTART);
1685 }
1686 }
1687 return(EWOULDBLOCK);
1688 }
1689
1690 /*
1691 * If the current process has received a signal (should be caught or cause
1692 * termination, should interrupt current syscall), return the signal number.
1693 * Stop signals with default action are processed immediately, then cleared;
1694 * they aren't returned. This is checked after each entry to the system for
1695 * a syscall or trap (though this can usually be done without calling issignal
1696 * by checking the pending signal masks in the CURSIG macro.) The normal call
1697 * sequence is
1698 *
1699 * This routine is called via CURSIG/__cursig and the MP lock might not be
1700 * held. Obtain the MP lock for the duration of the operation.
1701 *
1702 * while (sig = CURSIG(curproc))
1703 * postsig(sig);
1704 */
1705 int
1706 issignal(struct lwp *lp, int maytrace)
1707 {
1708 struct proc *p = lp->lwp_proc;
1709 sigset_t mask;
1710 int sig, prop;
1711
1712 lwkt_gettoken(&proc_token);
1713
1714 for (;;) {
1715 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
1716
1717 /*
1718 * If this process is supposed to stop, stop this thread.
1719 */
1720 if (p->p_stat == SSTOP)
1721 tstop();
1722
1723 mask = lwp_sigpend(lp);
1724 SIGSETNAND(mask, lp->lwp_sigmask);
1725 if (p->p_flag & P_PPWAIT)
1726 SIG_STOPSIGMASK(mask);
1727 if (SIGISEMPTY(mask)) { /* no signal to send */
1728 lwkt_reltoken(&proc_token);
1729 return (0);
1730 }
1731 sig = sig_ffs(&mask);
1732
1733 STOPEVENT(p, S_SIG, sig);
1734
1735 /*
1736 * We should see pending but ignored signals
1737 * only if P_TRACED was on when they were posted.
1738 */
1739 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
1740 lwp_delsig(lp, sig);
1741 continue;
1742 }
1743 if (maytrace && (p->p_flag & P_TRACED) && (p->p_flag & P_PPWAIT) == 0) {
1744 /*
1745 * If traced, always stop, and stay stopped until
1746 * released by the parent.
1747 *
1748 * NOTE: SSTOP may get cleared during the loop,
1749 * but we do not re-notify the parent if we have
1750 * to loop several times waiting for the parent
1751 * to let us continue.
1752 *
1753 * XXX not sure if this is still true
1754 */
1755 p->p_xstat = sig;
1756 proc_stop(p);
1757 do {
1758 tstop();
1759 } while (!trace_req(p) && (p->p_flag & P_TRACED));
1760
1761 /*
1762 * If parent wants us to take the signal,
1763 * then it will leave it in p->p_xstat;
1764 * otherwise we just look for signals again.
1765 */
1766 lwp_delsig(lp, sig); /* clear old signal */
1767 sig = p->p_xstat;
1768 if (sig == 0)
1769 continue;
1770
1771 /*
1772 * Put the new signal into p_siglist. If the
1773 * signal is being masked, look for other signals.
1774 *
1775 * XXX lwp might need a call to ksignal()
1776 */
1777 SIGADDSET(p->p_siglist, sig);
1778 if (SIGISMEMBER(lp->lwp_sigmask, sig))
1779 continue;
1780
1781 /*
1782 * If the traced bit got turned off, go back up
1783 * to the top to rescan signals. This ensures
1784 * that p_sig* and ps_sigact are consistent.
1785 */
1786 if ((p->p_flag & P_TRACED) == 0)
1787 continue;
1788 }
1789
1790 prop = sigprop(sig);
1791
1792 /*
1793 * Decide whether the signal should be returned.
1794 * Return the signal's number, or fall through
1795 * to clear it from the pending mask.
1796 */
1797 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
1798 case (intptr_t)SIG_DFL:
1799 /*
1800 * Don't take default actions on system processes.
1801 */
1802 if (p->p_pid <= 1) {
1803 #ifdef DIAGNOSTIC
1804 /*
1805 * Are you sure you want to ignore SIGSEGV
1806 * in init? XXX
1807 */
1808 kprintf("Process (pid %lu) got signal %d\n",
1809 (u_long)p->p_pid, sig);
1810 #endif
1811 break; /* == ignore */
1812 }
1813
1814 /*
1815 * Handle the in-kernel checkpoint action
1816 */
1817 if (prop & SA_CKPT) {
1818 checkpoint_signal_handler(lp);
1819 break;
1820 }
1821
1822 /*
1823 * If there is a pending stop signal to process
1824 * with default action, stop here,
1825 * then clear the signal. However,
1826 * if process is member of an orphaned
1827 * process group, ignore tty stop signals.
1828 */
1829 if (prop & SA_STOP) {
1830 if (p->p_flag & P_TRACED ||
1831 (p->p_pgrp->pg_jobc == 0 &&
1832 prop & SA_TTYSTOP))
1833 break; /* == ignore */
1834 p->p_xstat = sig;
1835 proc_stop(p);
1836 tstop();
1837 break;
1838 } else if (prop & SA_IGNORE) {
1839 /*
1840 * Except for SIGCONT, shouldn't get here.
1841 * Default action is to ignore; drop it.
1842 */
1843 break; /* == ignore */
1844 } else {
1845 lwkt_reltoken(&proc_token);
1846 return (sig);
1847 }
1848
1849 /*NOTREACHED*/
1850
1851 case (intptr_t)SIG_IGN:
1852 /*
1853 * Masking above should prevent us ever trying
1854 * to take action on an ignored signal other
1855 * than SIGCONT, unless process is traced.
1856 */
1857 if ((prop & SA_CONT) == 0 &&
1858 (p->p_flag & P_TRACED) == 0)
1859 kprintf("issignal\n");
1860 break; /* == ignore */
1861
1862 default:
1863 /*
1864 * This signal has an action, let
1865 * postsig() process it.
1866 */
1867 lwkt_reltoken(&proc_token);
1868 return (sig);
1869 }
1870 lwp_delsig(lp, sig); /* take the signal! */
1871 }
1872 /* NOTREACHED */
1873 }
1874
1875 /*
1876 * Take the action for the specified signal
1877 * from the current set of pending signals.
1878 */
1879 void
1880 postsig(int sig)
1881 {
1882 struct lwp *lp = curthread->td_lwp;
1883 struct proc *p = lp->lwp_proc;
1884 struct sigacts *ps = p->p_sigacts;
1885 sig_t action;
1886 sigset_t returnmask;
1887 int code;
1888
1889 KASSERT(sig != 0, ("postsig"));
1890
1891 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
1892
1893 /*
1894 * If we are a virtual kernel running an emulated user process
1895 * context, switch back to the virtual kernel context before
1896 * trying to post the signal.
1897 */
1898 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
1899 struct trapframe *tf = lp->lwp_md.md_regs;
1900 tf->tf_trapno = 0;
1901 vkernel_trap(lp, tf);
1902 }
1903
1904 lwp_delsig(lp, sig);
1905 action = ps->ps_sigact[_SIG_IDX(sig)];
1906 #ifdef KTRACE
1907 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
1908 ktrpsig(lp, sig, action, lp->lwp_flag & LWP_OLDMASK ?
1909 &lp->lwp_oldsigmask : &lp->lwp_sigmask, 0);
1910 #endif
1911 STOPEVENT(p, S_SIG, sig);
1912
1913 if (action == SIG_DFL) {
1914 /*
1915 * Default action, where the default is to kill
1916 * the process. (Other cases were ignored above.)
1917 */
1918 sigexit(lp, sig);
1919 /* NOTREACHED */
1920 } else {
1921 /*
1922 * If we get here, the signal must be caught.
1923 */
1924 KASSERT(action != SIG_IGN && !SIGISMEMBER(lp->lwp_sigmask, sig),
1925 ("postsig action"));
1926
1927 crit_enter();
1928
1929 /*
1930 * Reset the signal handler if asked to
1931 */
1932 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
1933 /*
1934 * See kern_sigaction() for origin of this code.
1935 */
1936 SIGDELSET(p->p_sigcatch, sig);
1937 if (sig != SIGCONT &&
1938 sigprop(sig) & SA_IGNORE)
1939 SIGADDSET(p->p_sigignore, sig);
1940 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1941 }
1942
1943 /*
1944 * Handle the mailbox case. Copyout to the appropriate
1945 * location but do not generate a signal frame. The system
1946 * call simply returns EINTR and the user is responsible for
1947 * polling the mailbox.
1948 */
1949 if (SIGISMEMBER(ps->ps_sigmailbox, sig)) {
1950 int sig_copy = sig;
1951 copyout(&sig_copy, (void *)action, sizeof(int));
1952 curproc->p_flag |= P_MAILBOX;
1953 crit_exit();
1954 goto done;
1955 }
1956
1957 /*
1958 * Set the signal mask and calculate the mask to restore
1959 * when the signal function returns.
1960 *
1961 * Special case: user has done a sigsuspend. Here the
1962 * current mask is not of interest, but rather the
1963 * mask from before the sigsuspend is what we want
1964 * restored after the signal processing is completed.
1965 */
1966 if (lp->lwp_flag & LWP_OLDMASK) {
1967 returnmask = lp->lwp_oldsigmask;
1968 lp->lwp_flag &= ~LWP_OLDMASK;
1969 } else {
1970 returnmask = lp->lwp_sigmask;
1971 }
1972
1973 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
1974 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1975 SIGADDSET(lp->lwp_sigmask, sig);
1976
1977 crit_exit();
1978 lp->lwp_ru.ru_nsignals++;
1979 if (lp->lwp_sig != sig) {
1980 code = 0;
1981 } else {
1982 code = lp->lwp_code;
1983 lp->lwp_code = 0;
1984 lp->lwp_sig = 0;
1985 }
1986 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
1987 }
1988 done:
1989 ;
1990 }
1991
1992 /*
1993 * Kill the current process for stated reason.
1994 */
1995 void
1996 killproc(struct proc *p, char *why)
1997 {
1998 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n",
1999 p->p_pid, p->p_comm,
2000 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
2001 ksignal(p, SIGKILL);
2002 }
2003
2004 /*
2005 * Force the current process to exit with the specified signal, dumping core
2006 * if appropriate. We bypass the normal tests for masked and caught signals,
2007 * allowing unrecoverable failures to terminate the process without changing
2008 * signal state. Mark the accounting record with the signal termination.
2009 * If dumping core, save the signal number for the debugger. Calls exit and
2010 * does not return.
2011 *
2012 * This routine does not return.
2013 */
2014 void
2015 sigexit(struct lwp *lp, int sig)
2016 {
2017 struct proc *p = lp->lwp_proc;
2018
2019 p->p_acflag |= AXSIG;
2020 if (sigprop(sig) & SA_CORE) {
2021 lp->lwp_sig = sig;
2022 /*
2023 * Log signals which would cause core dumps
2024 * (Log as LOG_INFO to appease those who don't want
2025 * these messages.)
2026 * XXX : Todo, as well as euid, write out ruid too
2027 */
2028 if (coredump(lp, sig) == 0)
2029 sig |= WCOREFLAG;
2030 if (kern_logsigexit)
2031 log(LOG_INFO,
2032 "pid %d (%s), uid %d: exited on signal %d%s\n",
2033 p->p_pid, p->p_comm,
2034 p->p_ucred ? p->p_ucred->cr_uid : -1,
2035 sig &~ WCOREFLAG,
2036 sig & WCOREFLAG ? " (core dumped)" : "");
2037 }
2038 exit1(W_EXITCODE(0, sig));
2039 /* NOTREACHED */
2040 }
2041
2042 static char corefilename[MAXPATHLEN+1] = {"%N.core"};
2043 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
2044 sizeof(corefilename), "process corefile name format string");
2045
2046 /*
2047 * expand_name(name, uid, pid)
2048 * Expand the name described in corefilename, using name, uid, and pid.
2049 * corefilename is a kprintf-like string, with three format specifiers:
2050 * %N name of process ("name")
2051 * %P process id (pid)
2052 * %U user id (uid)
2053 * For example, "%N.core" is the default; they can be disabled completely
2054 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
2055 * This is controlled by the sysctl variable kern.corefile (see above).
2056 */
2057
2058 static char *
2059 expand_name(const char *name, uid_t uid, pid_t pid)
2060 {
2061 char *temp;
2062 char buf[11]; /* Buffer for pid/uid -- max 4B */
2063 int i, n;
2064 char *format = corefilename;
2065 size_t namelen;
2066
2067 temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
2068 if (temp == NULL)
2069 return NULL;
2070 namelen = strlen(name);
2071 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
2072 int l;
2073 switch (format[i]) {
2074 case '%': /* Format character */
2075 i++;
2076 switch (format[i]) {
2077 case '%':
2078 temp[n++] = '%';
2079 break;
2080 case 'N': /* process name */
2081 if ((n + namelen) > MAXPATHLEN) {
2082 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2083 pid, name, uid, temp, name);
2084 kfree(temp, M_TEMP);
2085 return NULL;
2086 }
2087 memcpy(temp+n, name, namelen);
2088 n += namelen;
2089 break;
2090 case 'P': /* process id */
2091 l = ksprintf(buf, "%u", pid);
2092 if ((n + l) > MAXPATHLEN) {
2093 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2094 pid, name, uid, temp, name);
2095 kfree(temp, M_TEMP);
2096 return NULL;
2097 }
2098 memcpy(temp+n, buf, l);
2099 n += l;
2100 break;
2101 case 'U': /* user id */
2102 l = ksprintf(buf, "%u", uid);
2103 if ((n + l) > MAXPATHLEN) {
2104 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2105 pid, name, uid, temp, name);
2106 kfree(temp, M_TEMP);
2107 return NULL;
2108 }
2109 memcpy(temp+n, buf, l);
2110 n += l;
2111 break;
2112 default:
2113 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
2114 }
2115 break;
2116 default:
2117 temp[n++] = format[i];
2118 }
2119 }
2120 temp[n] = '\0';
2121 return temp;
2122 }
2123
2124 /*
2125 * Dump a process' core. The main routine does some
2126 * policy checking, and creates the name of the coredump;
2127 * then it passes on a vnode and a size limit to the process-specific
2128 * coredump routine if there is one; if there _is not_ one, it returns
2129 * ENOSYS; otherwise it returns the error from the process-specific routine.
2130 *
2131 * The parameter `lp' is the lwp which triggered the coredump.
2132 */
2133
2134 static int
2135 coredump(struct lwp *lp, int sig)
2136 {
2137 struct proc *p = lp->lwp_proc;
2138 struct vnode *vp;
2139 struct ucred *cred = p->p_ucred;
2140 struct flock lf;
2141 struct nlookupdata nd;
2142 struct vattr vattr;
2143 int error, error1;
2144 char *name; /* name of corefile */
2145 off_t limit;
2146
2147 STOPEVENT(p, S_CORE, 0);
2148
2149 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0)
2150 return (EFAULT);
2151
2152 /*
2153 * Note that the bulk of limit checking is done after
2154 * the corefile is created. The exception is if the limit
2155 * for corefiles is 0, in which case we don't bother
2156 * creating the corefile at all. This layout means that
2157 * a corefile is truncated instead of not being created,
2158 * if it is larger than the limit.
2159 */
2160 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
2161 if (limit == 0)
2162 return EFBIG;
2163
2164 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
2165 if (name == NULL)
2166 return (EINVAL);
2167 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
2168 if (error == 0)
2169 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
2170 kfree(name, M_TEMP);
2171 if (error) {
2172 nlookup_done(&nd);
2173 return (error);
2174 }
2175 vp = nd.nl_open_vp;
2176 nd.nl_open_vp = NULL;
2177 nlookup_done(&nd);
2178
2179 vn_unlock(vp);
2180 lf.l_whence = SEEK_SET;
2181 lf.l_start = 0;
2182 lf.l_len = 0;
2183 lf.l_type = F_WRLCK;
2184 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0);
2185 if (error)
2186 goto out2;
2187
2188 /* Don't dump to non-regular files or files with links. */
2189 if (vp->v_type != VREG ||
2190 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) {
2191 error = EFAULT;
2192 goto out1;
2193 }
2194
2195 /* Don't dump to files current user does not own */
2196 if (vattr.va_uid != p->p_ucred->cr_uid) {
2197 error = EFAULT;
2198 goto out1;
2199 }
2200
2201 VATTR_NULL(&vattr);
2202 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2203 vattr.va_size = 0;
2204 VOP_SETATTR(vp, &vattr, cred);
2205 p->p_acflag |= ACORE;
2206 vn_unlock(vp);
2207
2208 error = p->p_sysent->sv_coredump ?
2209 p->p_sysent->sv_coredump(lp, sig, vp, limit) : ENOSYS;
2210
2211 out1:
2212 lf.l_type = F_UNLCK;
2213 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0);
2214 out2:
2215 error1 = vn_close(vp, FWRITE);
2216 if (error == 0)
2217 error = error1;
2218 return (error);
2219 }
2220
2221 /*
2222 * Nonexistent system call-- signal process (may want to handle it).
2223 * Flag error in case process won't see signal immediately (blocked or ignored).
2224 *
2225 * MPALMOSTSAFE
2226 */
2227 /* ARGSUSED */
2228 int
2229 sys_nosys(struct nosys_args *args)
2230 {
2231 lwpsignal(curproc, curthread->td_lwp, SIGSYS);
2232 return (EINVAL);
2233 }
2234
2235 /*
2236 * Send a SIGIO or SIGURG signal to a process or process group using
2237 * stored credentials rather than those of the current process.
2238 */
2239 void
2240 pgsigio(struct sigio *sigio, int sig, int checkctty)
2241 {
2242 if (sigio == NULL)
2243 return;
2244
2245 if (sigio->sio_pgid > 0) {
2246 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
2247 sigio->sio_proc))
2248 ksignal(sigio->sio_proc, sig);
2249 } else if (sigio->sio_pgid < 0) {
2250 struct proc *p;
2251
2252 lockmgr(&sigio->sio_pgrp->pg_lock, LK_EXCLUSIVE);
2253 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
2254 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
2255 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
2256 ksignal(p, sig);
2257 }
2258 lockmgr(&sigio->sio_pgrp->pg_lock, LK_RELEASE);
2259 }
2260 }
2261
2262 static int
2263 filt_sigattach(struct knote *kn)
2264 {
2265 struct proc *p = curproc;
2266
2267 kn->kn_ptr.p_proc = p;
2268 kn->kn_flags |= EV_CLEAR; /* automatically set */
2269
2270 /* XXX lock the proc here while adding to the list? */
2271 knote_insert(&p->p_klist, kn);
2272
2273 return (0);
2274 }
2275
2276 static void
2277 filt_sigdetach(struct knote *kn)
2278 {
2279 struct proc *p = kn->kn_ptr.p_proc;
2280
2281 knote_remove(&p->p_klist, kn);
2282 }
2283
2284 /*
2285 * signal knotes are shared with proc knotes, so we apply a mask to
2286 * the hint in order to differentiate them from process hints. This
2287 * could be avoided by using a signal-specific knote list, but probably
2288 * isn't worth the trouble.
2289 */
2290 static int
2291 filt_signal(struct knote *kn, long hint)
2292 {
2293 if (hint & NOTE_SIGNAL) {
2294 hint &= ~NOTE_SIGNAL;
2295
2296 if (kn->kn_id == hint)
2297 kn->kn_data++;
2298 }
2299 return (kn->kn_data != 0);
2300 }
DragonFly BSD