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kernel - procfs_token work
[dragonfly.git] / sys / kern / kern_sig.c
blobf930f27b3a0d573e73fdf34cd19acd384f8032cc
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 SIGDELSET(p->p_sigcatch, sig);
359 } else {
360 SIGDELSET(p->p_sigignore, sig);
361 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
362 SIGDELSET(p->p_sigcatch, sig);
363 else
364 SIGADDSET(p->p_sigcatch, sig);
365 }
366
367 crit_exit();
368 }
369 lwkt_reltoken(&proc_token);
370 return (0);
371 }
372
373 int
374 sys_sigaction(struct sigaction_args *uap)
375 {
376 struct sigaction act, oact;
377 struct sigaction *actp, *oactp;
378 int error;
379
380 actp = (uap->act != NULL) ? &act : NULL;
381 oactp = (uap->oact != NULL) ? &oact : NULL;
382 if (actp) {
383 error = copyin(uap->act, actp, sizeof(act));
384 if (error)
385 return (error);
386 }
387 error = kern_sigaction(uap->sig, actp, oactp);
388 if (oactp && !error) {
389 error = copyout(oactp, uap->oact, sizeof(oact));
390 }
391 return (error);
392 }
393
394 /*
395 * Initialize signal state for process 0;
396 * set to ignore signals that are ignored by default.
397 */
398 void
399 siginit(struct proc *p)
400 {
401 int i;
402
403 for (i = 1; i <= NSIG; i++)
404 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
405 SIGADDSET(p->p_sigignore, i);
406 }
407
408 /*
409 * Reset signals for an exec of the specified process.
410 */
411 void
412 execsigs(struct proc *p)
413 {
414 struct sigacts *ps = p->p_sigacts;
415 struct lwp *lp;
416 int sig;
417
418 lp = ONLY_LWP_IN_PROC(p);
419
420 /*
421 * Reset caught signals. Held signals remain held
422 * through p_sigmask (unless they were caught,
423 * and are now ignored by default).
424 */
425 while (SIGNOTEMPTY(p->p_sigcatch)) {
426 sig = sig_ffs(&p->p_sigcatch);
427 SIGDELSET(p->p_sigcatch, sig);
428 if (sigprop(sig) & SA_IGNORE) {
429 if (sig != SIGCONT)
430 SIGADDSET(p->p_sigignore, sig);
431 SIGDELSET(p->p_siglist, sig);
432 SIGDELSET(lp->lwp_siglist, sig);
433 }
434 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
435 }
436
437 /*
438 * Reset stack state to the user stack.
439 * Clear set of signals caught on the signal stack.
440 */
441 lp->lwp_sigstk.ss_flags = SS_DISABLE;
442 lp->lwp_sigstk.ss_size = 0;
443 lp->lwp_sigstk.ss_sp = 0;
444 lp->lwp_flag &= ~LWP_ALTSTACK;
445 /*
446 * Reset no zombies if child dies flag as Solaris does.
447 */
448 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
449 }
450
451 /*
452 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
453 *
454 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
455 * p == curproc.
456 */
457 int
458 kern_sigprocmask(int how, sigset_t *set, sigset_t *oset)
459 {
460 struct thread *td = curthread;
461 struct lwp *lp = td->td_lwp;
462 int error;
463
464 lwkt_gettoken(&proc_token);
465
466 if (oset != NULL)
467 *oset = lp->lwp_sigmask;
468
469 error = 0;
470 if (set != NULL) {
471 switch (how) {
472 case SIG_BLOCK:
473 SIG_CANTMASK(*set);
474 SIGSETOR(lp->lwp_sigmask, *set);
475 break;
476 case SIG_UNBLOCK:
477 SIGSETNAND(lp->lwp_sigmask, *set);
478 break;
479 case SIG_SETMASK:
480 SIG_CANTMASK(*set);
481 lp->lwp_sigmask = *set;
482 break;
483 default:
484 error = EINVAL;
485 break;
486 }
487 }
488
489 lwkt_reltoken(&proc_token);
490
491 return (error);
492 }
493
494 /*
495 * sigprocmask()
496 *
497 * MPSAFE
498 */
499 int
500 sys_sigprocmask(struct sigprocmask_args *uap)
501 {
502 sigset_t set, oset;
503 sigset_t *setp, *osetp;
504 int error;
505
506 setp = (uap->set != NULL) ? &set : NULL;
507 osetp = (uap->oset != NULL) ? &oset : NULL;
508 if (setp) {
509 error = copyin(uap->set, setp, sizeof(set));
510 if (error)
511 return (error);
512 }
513 error = kern_sigprocmask(uap->how, setp, osetp);
514 if (osetp && !error) {
515 error = copyout(osetp, uap->oset, sizeof(oset));
516 }
517 return (error);
518 }
519
520 /*
521 * MPSAFE
522 */
523 int
524 kern_sigpending(struct __sigset *set)
525 {
526 struct lwp *lp = curthread->td_lwp;
527
528 *set = lwp_sigpend(lp);
529
530 return (0);
531 }
532
533 /*
534 * MPSAFE
535 */
536 int
537 sys_sigpending(struct sigpending_args *uap)
538 {
539 sigset_t set;
540 int error;
541
542 error = kern_sigpending(&set);
543
544 if (error == 0)
545 error = copyout(&set, uap->set, sizeof(set));
546 return (error);
547 }
548
549 /*
550 * Suspend process until signal, providing mask to be set
551 * in the meantime.
552 *
553 * MPSAFE
554 */
555 int
556 kern_sigsuspend(struct __sigset *set)
557 {
558 struct thread *td = curthread;
559 struct lwp *lp = td->td_lwp;
560 struct proc *p = td->td_proc;
561 struct sigacts *ps = p->p_sigacts;
562
563 /*
564 * When returning from sigsuspend, we want
565 * the old mask to be restored after the
566 * signal handler has finished. Thus, we
567 * save it here and mark the sigacts structure
568 * to indicate this.
569 */
570 lp->lwp_oldsigmask = lp->lwp_sigmask;
571 lp->lwp_flag |= LWP_OLDMASK;
572
573 SIG_CANTMASK(*set);
574 lp->lwp_sigmask = *set;
575 while (tsleep(ps, PCATCH, "pause", 0) == 0)
576 /* void */;
577 /* always return EINTR rather than ERESTART... */
578 return (EINTR);
579 }
580
581 /*
582 * Note nonstandard calling convention: libc stub passes mask, not
583 * pointer, to save a copyin.
584 *
585 * MPSAFE
586 */
587 int
588 sys_sigsuspend(struct sigsuspend_args *uap)
589 {
590 sigset_t mask;
591 int error;
592
593 error = copyin(uap->sigmask, &mask, sizeof(mask));
594 if (error)
595 return (error);
596
597 error = kern_sigsuspend(&mask);
598
599 return (error);
600 }
601
602 /*
603 * MPSAFE
604 */
605 int
606 kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss)
607 {
608 struct thread *td = curthread;
609 struct lwp *lp = td->td_lwp;
610 struct proc *p = td->td_proc;
611
612 if ((lp->lwp_flag & LWP_ALTSTACK) == 0)
613 lp->lwp_sigstk.ss_flags |= SS_DISABLE;
614
615 if (oss)
616 *oss = lp->lwp_sigstk;
617
618 if (ss) {
619 if (ss->ss_flags & SS_DISABLE) {
620 if (lp->lwp_sigstk.ss_flags & SS_ONSTACK)
621 return (EINVAL);
622 lp->lwp_flag &= ~LWP_ALTSTACK;
623 lp->lwp_sigstk.ss_flags = ss->ss_flags;
624 } else {
625 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
626 return (ENOMEM);
627 lp->lwp_flag |= LWP_ALTSTACK;
628 lp->lwp_sigstk = *ss;
629 }
630 }
631
632 return (0);
633 }
634
635 /*
636 * MPSAFE
637 */
638 int
639 sys_sigaltstack(struct sigaltstack_args *uap)
640 {
641 stack_t ss, oss;
642 int error;
643
644 if (uap->ss) {
645 error = copyin(uap->ss, &ss, sizeof(ss));
646 if (error)
647 return (error);
648 }
649
650 error = kern_sigaltstack(uap->ss ? &ss : NULL,
651 uap->oss ? &oss : NULL);
652
653 if (error == 0 && uap->oss)
654 error = copyout(&oss, uap->oss, sizeof(*uap->oss));
655 return (error);
656 }
657
658 /*
659 * Common code for kill process group/broadcast kill.
660 * cp is calling process.
661 */
662 struct killpg_info {
663 int nfound;
664 int sig;
665 };
666
667 static int killpg_all_callback(struct proc *p, void *data);
668
669 static int
670 dokillpg(int sig, int pgid, int all)
671 {
672 struct killpg_info info;
673 struct proc *cp = curproc;
674 struct proc *p;
675 struct pgrp *pgrp;
676
677 info.nfound = 0;
678 info.sig = sig;
679
680 if (all) {
681 /*
682 * broadcast
683 */
684 allproc_scan(killpg_all_callback, &info);
685 } else {
686 if (pgid == 0) {
687 /*
688 * zero pgid means send to my process group.
689 */
690 pgrp = cp->p_pgrp;
691 } else {
692 pgrp = pgfind(pgid);
693 if (pgrp == NULL)
694 return (ESRCH);
695 }
696 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
697 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
698 if (p->p_pid <= 1 ||
699 p->p_stat == SZOMB ||
700 (p->p_flag & P_SYSTEM) ||
701 !CANSIGNAL(p, sig)) {
702 continue;
703 }
704 ++info.nfound;
705 if (sig)
706 ksignal(p, sig);
707 }
708 lockmgr(&pgrp->pg_lock, LK_RELEASE);
709 }
710 return (info.nfound ? 0 : ESRCH);
711 }
712
713 static int
714 killpg_all_callback(struct proc *p, void *data)
715 {
716 struct killpg_info *info = data;
717
718 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) ||
719 p == curproc || !CANSIGNAL(p, info->sig)) {
720 return (0);
721 }
722 ++info->nfound;
723 if (info->sig)
724 ksignal(p, info->sig);
725 return(0);
726 }
727
728 /*
729 * Send a general signal to a process or LWPs within that process. Note
730 * that new signals cannot be sent if a process is exiting.
731 *
732 * No requirements.
733 */
734 int
735 kern_kill(int sig, pid_t pid, lwpid_t tid)
736 {
737 int t;
738
739 if ((u_int)sig > _SIG_MAXSIG)
740 return (EINVAL);
741
742 lwkt_gettoken(&proc_token);
743
744 if (pid > 0) {
745 struct proc *p;
746 struct lwp *lp = NULL;
747
748 /* kill single process */
749 if ((p = pfind(pid)) == NULL) {
750 lwkt_reltoken(&proc_token);
751 return (ESRCH);
752 }
753 if (!CANSIGNAL(p, sig)) {
754 lwkt_reltoken(&proc_token);
755 return (EPERM);
756 }
757
758 /*
759 * NOP if the process is exiting. Note that lwpsignal() is
760 * called directly with P_WEXIT set to kill individual LWPs
761 * during exit, which is allowed.
762 */
763 if (p->p_flag & P_WEXIT) {
764 lwkt_reltoken(&proc_token);
765 return (0);
766 }
767 if (tid != -1) {
768 lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, tid);
769 if (lp == NULL) {
770 lwkt_reltoken(&proc_token);
771 return (ESRCH);
772 }
773 }
774 if (sig)
775 lwpsignal(p, lp, sig);
776 lwkt_reltoken(&proc_token);
777 return (0);
778 }
779 /*
780 * If we come here, pid is a special broadcast pid.
781 * This doesn't mix with a tid.
782 */
783 if (tid != -1) {
784 lwkt_reltoken(&proc_token);
785 return (EINVAL);
786 }
787 switch (pid) {
788 case -1: /* broadcast signal */
789 t = (dokillpg(sig, 0, 1));
790 break;
791 case 0: /* signal own process group */
792 t = (dokillpg(sig, 0, 0));
793 break;
794 default: /* negative explicit process group */
795 t = (dokillpg(sig, -pid, 0));
796 break;
797 }
798 lwkt_reltoken(&proc_token);
799 return t;
800 }
801
802 int
803 sys_kill(struct kill_args *uap)
804 {
805 int error;
806
807 error = kern_kill(uap->signum, uap->pid, -1);
808 return (error);
809 }
810
811 int
812 sys_lwp_kill(struct lwp_kill_args *uap)
813 {
814 int error;
815 pid_t pid = uap->pid;
816
817 /*
818 * A tid is mandatory for lwp_kill(), otherwise
819 * you could simply use kill().
820 */
821 if (uap->tid == -1)
822 return (EINVAL);
823
824 /*
825 * To save on a getpid() function call for intra-process
826 * signals, pid == -1 means current process.
827 */
828 if (pid == -1)
829 pid = curproc->p_pid;
830
831 error = kern_kill(uap->signum, pid, uap->tid);
832 return (error);
833 }
834
835 /*
836 * Send a signal to a process group.
837 */
838 void
839 gsignal(int pgid, int sig)
840 {
841 struct pgrp *pgrp;
842
843 if (pgid && (pgrp = pgfind(pgid)))
844 pgsignal(pgrp, sig, 0);
845 }
846
847 /*
848 * Send a signal to a process group. If checktty is 1,
849 * limit to members which have a controlling terminal.
850 *
851 * pg_lock interlocks against a fork that might be in progress, to
852 * ensure that the new child process picks up the signal.
853 */
854 void
855 pgsignal(struct pgrp *pgrp, int sig, int checkctty)
856 {
857 struct proc *p;
858
859 if (pgrp) {
860 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
861 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
862 if (checkctty == 0 || p->p_flag & P_CONTROLT)
863 ksignal(p, sig);
864 }
865 lockmgr(&pgrp->pg_lock, LK_RELEASE);
866 }
867 }
868
869 /*
870 * Send a signal caused by a trap to the current lwp. If it will be caught
871 * immediately, deliver it with correct code. Otherwise, post it normally.
872 *
873 * These signals may ONLY be delivered to the specified lwp and may never
874 * be delivered to the process generically.
875 */
876 void
877 trapsignal(struct lwp *lp, int sig, u_long code)
878 {
879 struct proc *p = lp->lwp_proc;
880 struct sigacts *ps = p->p_sigacts;
881
882 /*
883 * If we are a virtual kernel running an emulated user process
884 * context, switch back to the virtual kernel context before
885 * trying to post the signal.
886 */
887 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
888 struct trapframe *tf = lp->lwp_md.md_regs;
889 tf->tf_trapno = 0;
890 vkernel_trap(lp, tf);
891 }
892
893
894 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
895 !SIGISMEMBER(lp->lwp_sigmask, sig)) {
896 lp->lwp_ru.ru_nsignals++;
897 #ifdef KTRACE
898 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
899 ktrpsig(lp, sig, ps->ps_sigact[_SIG_IDX(sig)],
900 &lp->lwp_sigmask, code);
901 #endif
902 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
903 &lp->lwp_sigmask, code);
904 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
905 if (!SIGISMEMBER(ps->ps_signodefer, sig))
906 SIGADDSET(lp->lwp_sigmask, sig);
907 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
908 /*
909 * See kern_sigaction() for origin of this code.
910 */
911 SIGDELSET(p->p_sigcatch, sig);
912 if (sig != SIGCONT &&
913 sigprop(sig) & SA_IGNORE)
914 SIGADDSET(p->p_sigignore, sig);
915 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
916 }
917 } else {
918 lp->lwp_code = code; /* XXX for core dump/debugger */
919 lp->lwp_sig = sig; /* XXX to verify code */
920 lwpsignal(p, lp, sig);
921 }
922 }
923
924 /*
925 * Find a suitable lwp to deliver the signal to.
926 *
927 * Returns NULL if all lwps hold the signal blocked.
928 */
929 static struct lwp *
930 find_lwp_for_signal(struct proc *p, int sig)
931 {
932 struct lwp *lp;
933 struct lwp *run, *sleep, *stop;
934
935 /*
936 * If the running/preempted thread belongs to the proc to which
937 * the signal is being delivered and this thread does not block
938 * the signal, then we can avoid a context switch by delivering
939 * the signal to this thread, because it will return to userland
940 * soon anyways.
941 */
942 lp = lwkt_preempted_proc();
943 if (lp != NULL && lp->lwp_proc == p && !SIGISMEMBER(lp->lwp_sigmask, sig))
944 return (lp);
945
946 run = sleep = stop = NULL;
947 FOREACH_LWP_IN_PROC(lp, p) {
948 /*
949 * If the signal is being blocked by the lwp, then this
950 * lwp is not eligible for receiving the signal.
951 */
952 if (SIGISMEMBER(lp->lwp_sigmask, sig))
953 continue;
954
955 switch (lp->lwp_stat) {
956 case LSRUN:
957 run = lp;
958 break;
959
960 case LSSTOP:
961 stop = lp;
962 break;
963
964 case LSSLEEP:
965 if (lp->lwp_flag & LWP_SINTR)
966 sleep = lp;
967 break;
968 }
969 }
970
971 if (run != NULL)
972 return (run);
973 else if (sleep != NULL)
974 return (sleep);
975 else
976 return (stop);
977 }
978
979 /*
980 * Send the signal to the process. If the signal has an action, the action
981 * is usually performed by the target process rather than the caller; we add
982 * the signal to the set of pending signals for the process.
983 *
984 * Exceptions:
985 * o When a stop signal is sent to a sleeping process that takes the
986 * default action, the process is stopped without awakening it.
987 * o SIGCONT restarts stopped processes (or puts them back to sleep)
988 * regardless of the signal action (eg, blocked or ignored).
989 *
990 * Other ignored signals are discarded immediately.
991 *
992 * No requirements.
993 */
994 void
995 ksignal(struct proc *p, int sig)
996 {
997 lwpsignal(p, NULL, sig);
998 }
999
1000 /*
1001 * The core for ksignal. lp may be NULL, then a suitable thread
1002 * will be chosen. If not, lp MUST be a member of p.
1003 *
1004 * No requirements.
1005 */
1006 void
1007 lwpsignal(struct proc *p, struct lwp *lp, int sig)
1008 {
1009 int prop;
1010 sig_t action;
1011
1012 if (sig > _SIG_MAXSIG || sig <= 0) {
1013 kprintf("lwpsignal: signal %d\n", sig);
1014 panic("lwpsignal signal number");
1015 }
1016
1017 KKASSERT(lp == NULL || lp->lwp_proc == p);
1018
1019 lwkt_gettoken(&proc_token);
1020
1021 prop = sigprop(sig);
1022
1023 /*
1024 * If proc is traced, always give parent a chance;
1025 * if signal event is tracked by procfs, give *that*
1026 * a chance, as well.
1027 */
1028 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) {
1029 action = SIG_DFL;
1030 } else {
1031 /*
1032 * Do not try to deliver signals to an exiting lwp. Note
1033 * that we must still deliver the signal if P_WEXIT is set
1034 * in the process flags.
1035 */
1036 if (lp && (lp->lwp_flag & LWP_WEXIT)) {
1037 lwkt_reltoken(&proc_token);
1038 return;
1039 }
1040
1041 /*
1042 * If the signal is being ignored, then we forget about
1043 * it immediately. NOTE: We don't set SIGCONT in p_sigignore,
1044 * and if it is set to SIG_IGN, action will be SIG_DFL here.
1045 */
1046 if (SIGISMEMBER(p->p_sigignore, sig)) {
1047 lwkt_reltoken(&proc_token);
1048 return;
1049 }
1050 if (SIGISMEMBER(p->p_sigcatch, sig))
1051 action = SIG_CATCH;
1052 else
1053 action = SIG_DFL;
1054 }
1055
1056 /*
1057 * If continuing, clear any pending STOP signals.
1058 */
1059 if (prop & SA_CONT)
1060 SIG_STOPSIGMASK(p->p_siglist);
1061
1062 if (prop & SA_STOP) {
1063 /*
1064 * If sending a tty stop signal to a member of an orphaned
1065 * process group, discard the signal here if the action
1066 * is default; don't stop the process below if sleeping,
1067 * and don't clear any pending SIGCONT.
1068 */
1069 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
1070 action == SIG_DFL) {
1071 lwkt_reltoken(&proc_token);
1072 return;
1073 }
1074 SIG_CONTSIGMASK(p->p_siglist);
1075 p->p_flag &= ~P_CONTINUED;
1076 }
1077
1078 crit_enter();
1079
1080 if (p->p_stat == SSTOP) {
1081 /*
1082 * Nobody can handle this signal, add it to the lwp or
1083 * process pending list
1084 */
1085 if (lp)
1086 SIGADDSET(lp->lwp_siglist, sig);
1087 else
1088 SIGADDSET(p->p_siglist, sig);
1089
1090 /*
1091 * If the process is stopped and is being traced, then no
1092 * further action is necessary.
1093 */
1094 if (p->p_flag & P_TRACED)
1095 goto out;
1096
1097 /*
1098 * If the process is stopped and receives a KILL signal,
1099 * make the process runnable.
1100 */
1101 if (sig == SIGKILL) {
1102 proc_unstop(p);
1103 goto active_process;
1104 }
1105
1106 /*
1107 * If the process is stopped and receives a CONT signal,
1108 * then try to make the process runnable again.
1109 */
1110 if (prop & SA_CONT) {
1111 /*
1112 * If SIGCONT is default (or ignored), we continue the
1113 * process but don't leave the signal in p_siglist, as
1114 * it has no further action. If SIGCONT is held, we
1115 * continue the process and leave the signal in
1116 * p_siglist. If the process catches SIGCONT, let it
1117 * handle the signal itself.
1118 */
1119 /* XXX what if the signal is being held blocked? */
1120 p->p_flag |= P_CONTINUED;
1121 wakeup(p->p_pptr);
1122 if (action == SIG_DFL)
1123 SIGDELSET(p->p_siglist, sig);
1124 proc_unstop(p);
1125 if (action == SIG_CATCH)
1126 goto active_process;
1127 goto out;
1128 }
1129
1130 /*
1131 * If the process is stopped and receives another STOP
1132 * signal, we do not need to stop it again. If we did
1133 * the shell could get confused.
1134 *
1135 * However, if the current/preempted lwp is part of the
1136 * process receiving the signal, we need to keep it,
1137 * so that this lwp can stop in issignal() later, as
1138 * we don't want to wait until it reaches userret!
1139 */
1140 if (prop & SA_STOP) {
1141 if (lwkt_preempted_proc() == NULL ||
1142 lwkt_preempted_proc()->lwp_proc != p)
1143 SIGDELSET(p->p_siglist, sig);
1144 }
1145
1146 /*
1147 * Otherwise the process is stopped and it received some
1148 * signal, which does not change its stopped state.
1149 *
1150 * We have to select one thread to set LWP_BREAKTSLEEP,
1151 * so that the current signal will break the sleep
1152 * as soon as a SA_CONT signal will unstop the process.
1153 */
1154 if (lp == NULL)
1155 lp = find_lwp_for_signal(p, sig);
1156 if (lp != NULL &&
1157 (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP))
1158 lp->lwp_flag |= LWP_BREAKTSLEEP;
1159 goto out;
1160
1161 /* NOTREACHED */
1162 }
1163 /* else not stopped */
1164 active_process:
1165
1166 /*
1167 * Never deliver a lwp-specific signal to a random lwp.
1168 */
1169 if (lp == NULL) {
1170 lp = find_lwp_for_signal(p, sig);
1171 if (lp && SIGISMEMBER(lp->lwp_sigmask, sig))
1172 lp = NULL;
1173 }
1174
1175 /*
1176 * Deliver to the process generically if (1) the signal is being
1177 * sent to any thread or (2) we could not find a thread to deliver
1178 * it to.
1179 */
1180 if (lp == NULL) {
1181 SIGADDSET(p->p_siglist, sig);
1182 goto out;
1183 }
1184
1185 /*
1186 * Deliver to a specific LWP whether it masks it or not. It will
1187 * not be dispatched if masked but we must still deliver it.
1188 */
1189 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
1190 (p->p_flag & P_TRACED) == 0) {
1191 p->p_nice = NZERO;
1192 }
1193
1194 /*
1195 * If the process receives a STOP signal which indeed needs to
1196 * stop the process, do so. If the process chose to catch the
1197 * signal, it will be treated like any other signal.
1198 */
1199 if ((prop & SA_STOP) && action == SIG_DFL) {
1200 /*
1201 * If a child holding parent blocked, stopping
1202 * could cause deadlock. Take no action at this
1203 * time.
1204 */
1205 if (p->p_flag & P_PPWAIT) {
1206 SIGADDSET(p->p_siglist, sig);
1207 goto out;
1208 }
1209
1210 /*
1211 * Do not actually try to manipulate the process, but simply
1212 * stop it. Lwps will stop as soon as they safely can.
1213 */
1214 p->p_xstat = sig;
1215 proc_stop(p);
1216 goto out;
1217 }
1218
1219 /*
1220 * If it is a CONT signal with default action, just ignore it.
1221 */
1222 if ((prop & SA_CONT) && action == SIG_DFL)
1223 goto out;
1224
1225 /*
1226 * Mark signal pending at this specific thread.
1227 */
1228 SIGADDSET(lp->lwp_siglist, sig);
1229
1230 lwp_signotify(lp);
1231
1232 out:
1233 lwkt_reltoken(&proc_token);
1234 crit_exit();
1235 }
1236
1237 /*
1238 * proc_token must be held
1239 */
1240 static void
1241 lwp_signotify(struct lwp *lp)
1242 {
1243 ASSERT_LWKT_TOKEN_HELD(&proc_token);
1244 crit_enter();
1245
1246 if (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP) {
1247 /*
1248 * Thread is in tsleep.
1249 */
1250
1251 /*
1252 * If the thread is sleeping uninterruptibly
1253 * we can't interrupt the sleep... the signal will
1254 * be noticed when the lwp returns through
1255 * trap() or syscall().
1256 *
1257 * Otherwise the signal can interrupt the sleep.
1258 *
1259 * If the process is traced, the lwp will handle the
1260 * tracing in issignal() when it returns to userland.
1261 */
1262 if (lp->lwp_flag & LWP_SINTR) {
1263 /*
1264 * Make runnable and break out of any tsleep as well.
1265 */
1266 lp->lwp_flag |= LWP_BREAKTSLEEP;
1267 setrunnable(lp);
1268 }
1269 } else {
1270 /*
1271 * Otherwise the thread is running
1272 *
1273 * LSRUN does nothing with the signal, other than kicking
1274 * ourselves if we are running.
1275 * SZOMB and SIDL mean that it will either never be noticed,
1276 * or noticed very soon.
1277 *
1278 * Note that lwp_thread may be NULL or may not be completely
1279 * initialized if the process is in the SIDL or SZOMB state.
1280 *
1281 * For SMP we may have to forward the request to another cpu.
1282 * YYY the MP lock prevents the target process from moving
1283 * to another cpu, see kern/kern_switch.c
1284 *
1285 * If the target thread is waiting on its message port,
1286 * wakeup the target thread so it can check (or ignore)
1287 * the new signal. YYY needs cleanup.
1288 */
1289 if (lp == lwkt_preempted_proc()) {
1290 signotify();
1291 } else if (lp->lwp_stat == LSRUN) {
1292 struct thread *td = lp->lwp_thread;
1293 struct proc *p __debugvar = lp->lwp_proc;
1294
1295 KASSERT(td != NULL,
1296 ("pid %d/%d NULL lwp_thread stat %d flags %08x/%08x",
1297 p->p_pid, lp->lwp_tid, lp->lwp_stat,
1298 p->p_flag, lp->lwp_flag));
1299
1300 /*
1301 * To prevent a MP race with TDF_SINTR we must
1302 * schedule the thread on the correct cpu.
1303 */
1304 #ifdef SMP
1305 if (td->td_gd != mycpu) {
1306 LWPHOLD(lp);
1307 lwkt_send_ipiq(td->td_gd, signotify_remote, lp);
1308 } else
1309 #endif
1310 if (td->td_flags & TDF_SINTR)
1311 lwkt_schedule(td);
1312 }
1313 }
1314 crit_exit();
1315 }
1316
1317 #ifdef SMP
1318
1319 /*
1320 * This function is called via an IPI. We will be in a critical section but
1321 * the MP lock will NOT be held. Also note that by the time the ipi message
1322 * gets to us the process 'p' (arg) may no longer be scheduled or even valid.
1323 */
1324 static void
1325 signotify_remote(void *arg)
1326 {
1327 struct lwp *lp = arg;
1328
1329 if (lp == lwkt_preempted_proc()) {
1330 signotify();
1331 } else {
1332 struct thread *td = lp->lwp_thread;
1333 if (td->td_flags & TDF_SINTR)
1334 lwkt_schedule(td);
1335 }
1336 LWPRELE(lp);
1337 }
1338
1339 #endif
1340
1341 /*
1342 * Caller must hold proc_token
1343 */
1344 void
1345 proc_stop(struct proc *p)
1346 {
1347 struct lwp *lp;
1348
1349 ASSERT_LWKT_TOKEN_HELD(&proc_token);
1350 crit_enter();
1351
1352 /* If somebody raced us, be happy with it */
1353 if (p->p_stat == SSTOP || p->p_stat == SZOMB) {
1354 crit_exit();
1355 return;
1356 }
1357 p->p_stat = SSTOP;
1358
1359 FOREACH_LWP_IN_PROC(lp, p) {
1360 switch (lp->lwp_stat) {
1361 case LSSTOP:
1362 /*
1363 * Do nothing, we are already counted in
1364 * p_nstopped.
1365 */
1366 break;
1367
1368 case LSSLEEP:
1369 /*
1370 * We're sleeping, but we will stop before
1371 * returning to userspace, so count us
1372 * as stopped as well. We set LWP_WSTOP
1373 * to signal the lwp that it should not
1374 * increase p_nstopped when reaching tstop().
1375 */
1376 if ((lp->lwp_flag & LWP_WSTOP) == 0) {
1377 lp->lwp_flag |= LWP_WSTOP;
1378 ++p->p_nstopped;
1379 }
1380 break;
1381
1382 case LSRUN:
1383 /*
1384 * We might notify ourself, but that's not
1385 * a problem.
1386 */
1387 lwp_signotify(lp);
1388 break;
1389 }
1390 }
1391
1392 if (p->p_nstopped == p->p_nthreads) {
1393 p->p_flag &= ~P_WAITED;
1394 wakeup(p->p_pptr);
1395 if ((p->p_pptr->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1396 ksignal(p->p_pptr, SIGCHLD);
1397 }
1398 crit_exit();
1399 }
1400
1401 /*
1402 * Caller must hold proc_token
1403 */
1404 void
1405 proc_unstop(struct proc *p)
1406 {
1407 struct lwp *lp;
1408
1409 ASSERT_LWKT_TOKEN_HELD(&proc_token);
1410 crit_enter();
1411
1412 if (p->p_stat != SSTOP) {
1413 crit_exit();
1414 return;
1415 }
1416
1417 p->p_stat = SACTIVE;
1418
1419 FOREACH_LWP_IN_PROC(lp, p) {
1420 switch (lp->lwp_stat) {
1421 case LSRUN:
1422 /*
1423 * Uh? Not stopped? Well, I guess that's okay.
1424 */
1425 if (bootverbose)
1426 kprintf("proc_unstop: lwp %d/%d not sleeping\n",
1427 p->p_pid, lp->lwp_tid);
1428 break;
1429
1430 case LSSLEEP:
1431 /*
1432 * Still sleeping. Don't bother waking it up.
1433 * However, if this thread was counted as
1434 * stopped, undo this.
1435 *
1436 * Nevertheless we call setrunnable() so that it
1437 * will wake up in case a signal or timeout arrived
1438 * in the meantime.
1439 */
1440 if (lp->lwp_flag & LWP_WSTOP) {
1441 lp->lwp_flag &= ~LWP_WSTOP;
1442 --p->p_nstopped;
1443 } else {
1444 if (bootverbose)
1445 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n",
1446 p->p_pid, lp->lwp_tid);
1447 }
1448 /* FALLTHROUGH */
1449
1450 case LSSTOP:
1451 setrunnable(lp);
1452 break;
1453
1454 }
1455 }
1456 crit_exit();
1457 }
1458
1459 /*
1460 * No requirements.
1461 *
1462 * XXX: Holds the proc_token for longer than it probably needs to.
1463 */
1464 static int
1465 kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout)
1466 {
1467 sigset_t savedmask, set;
1468 struct proc *p = curproc;
1469 struct lwp *lp = curthread->td_lwp;
1470 int error, sig, hz, timevalid = 0;
1471 struct timespec rts, ets, ts;
1472 struct timeval tv;
1473
1474 lwkt_gettoken(&proc_token);
1475
1476 error = 0;
1477 sig = 0;
1478 ets.tv_sec = 0; /* silence compiler warning */
1479 ets.tv_nsec = 0; /* silence compiler warning */
1480 SIG_CANTMASK(waitset);
1481 savedmask = lp->lwp_sigmask;
1482
1483 if (timeout) {
1484 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 &&
1485 timeout->tv_nsec < 1000000000) {
1486 timevalid = 1;
1487 getnanouptime(&rts);
1488 ets = rts;
1489 timespecadd(&ets, timeout);
1490 }
1491 }
1492
1493 for (;;) {
1494 set = lwp_sigpend(lp);
1495 SIGSETAND(set, waitset);
1496 if ((sig = sig_ffs(&set)) != 0) {
1497 SIGFILLSET(lp->lwp_sigmask);
1498 SIGDELSET(lp->lwp_sigmask, sig);
1499 SIG_CANTMASK(lp->lwp_sigmask);
1500 sig = issignal(lp, 1);
1501 /*
1502 * It may be a STOP signal, in the case, issignal
1503 * returns 0, because we may stop there, and new
1504 * signal can come in, we should restart if we got
1505 * nothing.
1506 */
1507 if (sig == 0)
1508 continue;
1509 else
1510 break;
1511 }
1512
1513 /*
1514 * Previous checking got nothing, and we retried but still
1515 * got nothing, we should return the error status.
1516 */
1517 if (error)
1518 break;
1519
1520 /*
1521 * POSIX says this must be checked after looking for pending
1522 * signals.
1523 */
1524 if (timeout) {
1525 if (timevalid == 0) {
1526 error = EINVAL;
1527 break;
1528 }
1529 getnanouptime(&rts);
1530 if (timespeccmp(&rts, &ets, >=)) {
1531 error = EAGAIN;
1532 break;
1533 }
1534 ts = ets;
1535 timespecsub(&ts, &rts);
1536 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1537 hz = tvtohz_high(&tv);
1538 } else
1539 hz = 0;
1540
1541 lp->lwp_sigmask = savedmask;
1542 SIGSETNAND(lp->lwp_sigmask, waitset);
1543 /*
1544 * We won't ever be woken up. Instead, our sleep will
1545 * be broken in lwpsignal().
1546 */
1547 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz);
1548 if (timeout) {
1549 if (error == ERESTART) {
1550 /* can not restart a timeout wait. */
1551 error = EINTR;
1552 } else if (error == EAGAIN) {
1553 /* will calculate timeout by ourself. */
1554 error = 0;
1555 }
1556 }
1557 /* Retry ... */
1558 }
1559
1560 lp->lwp_sigmask = savedmask;
1561 if (sig) {
1562 error = 0;
1563 bzero(info, sizeof(*info));
1564 info->si_signo = sig;
1565 lwp_delsig(lp, sig); /* take the signal! */
1566
1567 if (sig == SIGKILL)
1568 sigexit(lp, sig);
1569 }
1570
1571 lwkt_reltoken(&proc_token);
1572
1573 return (error);
1574 }
1575
1576 /*
1577 * MPALMOSTSAFE
1578 */
1579 int
1580 sys_sigtimedwait(struct sigtimedwait_args *uap)
1581 {
1582 struct timespec ts;
1583 struct timespec *timeout;
1584 sigset_t set;
1585 siginfo_t info;
1586 int error;
1587
1588 if (uap->timeout) {
1589 error = copyin(uap->timeout, &ts, sizeof(ts));
1590 if (error)
1591 return (error);
1592 timeout = &ts;
1593 } else {
1594 timeout = NULL;
1595 }
1596 error = copyin(uap->set, &set, sizeof(set));
1597 if (error)
1598 return (error);
1599 error = kern_sigtimedwait(set, &info, timeout);
1600 if (error)
1601 return (error);
1602 if (uap->info)
1603 error = copyout(&info, uap->info, sizeof(info));
1604 /* Repost if we got an error. */
1605 /*
1606 * XXX lwp
1607 *
1608 * This could transform a thread-specific signal to another
1609 * thread / process pending signal.
1610 */
1611 if (error) {
1612 ksignal(curproc, info.si_signo);
1613 } else {
1614 uap->sysmsg_result = info.si_signo;
1615 }
1616 return (error);
1617 }
1618
1619 /*
1620 * MPALMOSTSAFE
1621 */
1622 int
1623 sys_sigwaitinfo(struct sigwaitinfo_args *uap)
1624 {
1625 siginfo_t info;
1626 sigset_t set;
1627 int error;
1628
1629 error = copyin(uap->set, &set, sizeof(set));
1630 if (error)
1631 return (error);
1632 error = kern_sigtimedwait(set, &info, NULL);
1633 if (error)
1634 return (error);
1635 if (uap->info)
1636 error = copyout(&info, uap->info, sizeof(info));
1637 /* Repost if we got an error. */
1638 /*
1639 * XXX lwp
1640 *
1641 * This could transform a thread-specific signal to another
1642 * thread / process pending signal.
1643 */
1644 if (error) {
1645 ksignal(curproc, info.si_signo);
1646 } else {
1647 uap->sysmsg_result = info.si_signo;
1648 }
1649 return (error);
1650 }
1651
1652 /*
1653 * If the current process has received a signal that would interrupt a
1654 * system call, return EINTR or ERESTART as appropriate.
1655 */
1656 int
1657 iscaught(struct lwp *lp)
1658 {
1659 struct proc *p = lp->lwp_proc;
1660 int sig;
1661
1662 if (p) {
1663 if ((sig = CURSIG(lp)) != 0) {
1664 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1665 return (EINTR);
1666 return (ERESTART);
1667 }
1668 }
1669 return(EWOULDBLOCK);
1670 }
1671
1672 /*
1673 * If the current process has received a signal (should be caught or cause
1674 * termination, should interrupt current syscall), return the signal number.
1675 * Stop signals with default action are processed immediately, then cleared;
1676 * they aren't returned. This is checked after each entry to the system for
1677 * a syscall or trap (though this can usually be done without calling issignal
1678 * by checking the pending signal masks in the CURSIG macro.) The normal call
1679 * sequence is
1680 *
1681 * This routine is called via CURSIG/__cursig and the MP lock might not be
1682 * held. Obtain the MP lock for the duration of the operation.
1683 *
1684 * while (sig = CURSIG(curproc))
1685 * postsig(sig);
1686 */
1687 int
1688 issignal(struct lwp *lp, int maytrace)
1689 {
1690 struct proc *p = lp->lwp_proc;
1691 sigset_t mask;
1692 int sig, prop;
1693
1694 lwkt_gettoken(&proc_token);
1695
1696 for (;;) {
1697 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
1698
1699 /*
1700 * If this process is supposed to stop, stop this thread.
1701 */
1702 if (p->p_stat == SSTOP)
1703 tstop();
1704
1705 mask = lwp_sigpend(lp);
1706 SIGSETNAND(mask, lp->lwp_sigmask);
1707 if (p->p_flag & P_PPWAIT)
1708 SIG_STOPSIGMASK(mask);
1709 if (SIGISEMPTY(mask)) { /* no signal to send */
1710 lwkt_reltoken(&proc_token);
1711 return (0);
1712 }
1713 sig = sig_ffs(&mask);
1714
1715 STOPEVENT(p, S_SIG, sig);
1716
1717 /*
1718 * We should see pending but ignored signals
1719 * only if P_TRACED was on when they were posted.
1720 */
1721 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
1722 lwp_delsig(lp, sig);
1723 continue;
1724 }
1725 if (maytrace && (p->p_flag & P_TRACED) && (p->p_flag & P_PPWAIT) == 0) {
1726 /*
1727 * If traced, always stop, and stay stopped until
1728 * released by the parent.
1729 *
1730 * NOTE: SSTOP may get cleared during the loop,
1731 * but we do not re-notify the parent if we have
1732 * to loop several times waiting for the parent
1733 * to let us continue.
1734 *
1735 * XXX not sure if this is still true
1736 */
1737 p->p_xstat = sig;
1738 proc_stop(p);
1739 do {
1740 tstop();
1741 } while (!trace_req(p) && (p->p_flag & P_TRACED));
1742
1743 /*
1744 * If parent wants us to take the signal,
1745 * then it will leave it in p->p_xstat;
1746 * otherwise we just look for signals again.
1747 */
1748 lwp_delsig(lp, sig); /* clear old signal */
1749 sig = p->p_xstat;
1750 if (sig == 0)
1751 continue;
1752
1753 /*
1754 * Put the new signal into p_siglist. If the
1755 * signal is being masked, look for other signals.
1756 *
1757 * XXX lwp might need a call to ksignal()
1758 */
1759 SIGADDSET(p->p_siglist, sig);
1760 if (SIGISMEMBER(lp->lwp_sigmask, sig))
1761 continue;
1762
1763 /*
1764 * If the traced bit got turned off, go back up
1765 * to the top to rescan signals. This ensures
1766 * that p_sig* and ps_sigact are consistent.
1767 */
1768 if ((p->p_flag & P_TRACED) == 0)
1769 continue;
1770 }
1771
1772 prop = sigprop(sig);
1773
1774 /*
1775 * Decide whether the signal should be returned.
1776 * Return the signal's number, or fall through
1777 * to clear it from the pending mask.
1778 */
1779 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
1780 case (intptr_t)SIG_DFL:
1781 /*
1782 * Don't take default actions on system processes.
1783 */
1784 if (p->p_pid <= 1) {
1785 #ifdef DIAGNOSTIC
1786 /*
1787 * Are you sure you want to ignore SIGSEGV
1788 * in init? XXX
1789 */
1790 kprintf("Process (pid %lu) got signal %d\n",
1791 (u_long)p->p_pid, sig);
1792 #endif
1793 break; /* == ignore */
1794 }
1795
1796 /*
1797 * Handle the in-kernel checkpoint action
1798 */
1799 if (prop & SA_CKPT) {
1800 checkpoint_signal_handler(lp);
1801 break;
1802 }
1803
1804 /*
1805 * If there is a pending stop signal to process
1806 * with default action, stop here,
1807 * then clear the signal. However,
1808 * if process is member of an orphaned
1809 * process group, ignore tty stop signals.
1810 */
1811 if (prop & SA_STOP) {
1812 if (p->p_flag & P_TRACED ||
1813 (p->p_pgrp->pg_jobc == 0 &&
1814 prop & SA_TTYSTOP))
1815 break; /* == ignore */
1816 p->p_xstat = sig;
1817 proc_stop(p);
1818 tstop();
1819 break;
1820 } else if (prop & SA_IGNORE) {
1821 /*
1822 * Except for SIGCONT, shouldn't get here.
1823 * Default action is to ignore; drop it.
1824 */
1825 break; /* == ignore */
1826 } else {
1827 lwkt_reltoken(&proc_token);
1828 return (sig);
1829 }
1830
1831 /*NOTREACHED*/
1832
1833 case (intptr_t)SIG_IGN:
1834 /*
1835 * Masking above should prevent us ever trying
1836 * to take action on an ignored signal other
1837 * than SIGCONT, unless process is traced.
1838 */
1839 if ((prop & SA_CONT) == 0 &&
1840 (p->p_flag & P_TRACED) == 0)
1841 kprintf("issignal\n");
1842 break; /* == ignore */
1843
1844 default:
1845 /*
1846 * This signal has an action, let
1847 * postsig() process it.
1848 */
1849 lwkt_reltoken(&proc_token);
1850 return (sig);
1851 }
1852 lwp_delsig(lp, sig); /* take the signal! */
1853 }
1854 /* NOTREACHED */
1855 }
1856
1857 /*
1858 * Take the action for the specified signal
1859 * from the current set of pending signals.
1860 */
1861 void
1862 postsig(int sig)
1863 {
1864 struct lwp *lp = curthread->td_lwp;
1865 struct proc *p = lp->lwp_proc;
1866 struct sigacts *ps = p->p_sigacts;
1867 sig_t action;
1868 sigset_t returnmask;
1869 int code;
1870
1871 KASSERT(sig != 0, ("postsig"));
1872
1873 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
1874
1875 /*
1876 * If we are a virtual kernel running an emulated user process
1877 * context, switch back to the virtual kernel context before
1878 * trying to post the signal.
1879 */
1880 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
1881 struct trapframe *tf = lp->lwp_md.md_regs;
1882 tf->tf_trapno = 0;
1883 vkernel_trap(lp, tf);
1884 }
1885
1886 lwp_delsig(lp, sig);
1887 action = ps->ps_sigact[_SIG_IDX(sig)];
1888 #ifdef KTRACE
1889 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
1890 ktrpsig(lp, sig, action, lp->lwp_flag & LWP_OLDMASK ?
1891 &lp->lwp_oldsigmask : &lp->lwp_sigmask, 0);
1892 #endif
1893 STOPEVENT(p, S_SIG, sig);
1894
1895 if (action == SIG_DFL) {
1896 /*
1897 * Default action, where the default is to kill
1898 * the process. (Other cases were ignored above.)
1899 */
1900 sigexit(lp, sig);
1901 /* NOTREACHED */
1902 } else {
1903 /*
1904 * If we get here, the signal must be caught.
1905 */
1906 KASSERT(action != SIG_IGN && !SIGISMEMBER(lp->lwp_sigmask, sig),
1907 ("postsig action"));
1908
1909 crit_enter();
1910
1911 /*
1912 * Reset the signal handler if asked to
1913 */
1914 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
1915 /*
1916 * See kern_sigaction() for origin of this code.
1917 */
1918 SIGDELSET(p->p_sigcatch, sig);
1919 if (sig != SIGCONT &&
1920 sigprop(sig) & SA_IGNORE)
1921 SIGADDSET(p->p_sigignore, sig);
1922 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1923 }
1924
1925 /*
1926 * Handle the mailbox case. Copyout to the appropriate
1927 * location but do not generate a signal frame. The system
1928 * call simply returns EINTR and the user is responsible for
1929 * polling the mailbox.
1930 */
1931 if (SIGISMEMBER(ps->ps_sigmailbox, sig)) {
1932 int sig_copy = sig;
1933 copyout(&sig_copy, (void *)action, sizeof(int));
1934 curproc->p_flag |= P_MAILBOX;
1935 crit_exit();
1936 goto done;
1937 }
1938
1939 /*
1940 * Set the signal mask and calculate the mask to restore
1941 * when the signal function returns.
1942 *
1943 * Special case: user has done a sigsuspend. Here the
1944 * current mask is not of interest, but rather the
1945 * mask from before the sigsuspend is what we want
1946 * restored after the signal processing is completed.
1947 */
1948 if (lp->lwp_flag & LWP_OLDMASK) {
1949 returnmask = lp->lwp_oldsigmask;
1950 lp->lwp_flag &= ~LWP_OLDMASK;
1951 } else {
1952 returnmask = lp->lwp_sigmask;
1953 }
1954
1955 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
1956 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1957 SIGADDSET(lp->lwp_sigmask, sig);
1958
1959 crit_exit();
1960 lp->lwp_ru.ru_nsignals++;
1961 if (lp->lwp_sig != sig) {
1962 code = 0;
1963 } else {
1964 code = lp->lwp_code;
1965 lp->lwp_code = 0;
1966 lp->lwp_sig = 0;
1967 }
1968 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
1969 }
1970 done:
1971 ;
1972 }
1973
1974 /*
1975 * Kill the current process for stated reason.
1976 */
1977 void
1978 killproc(struct proc *p, char *why)
1979 {
1980 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n",
1981 p->p_pid, p->p_comm,
1982 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
1983 ksignal(p, SIGKILL);
1984 }
1985
1986 /*
1987 * Force the current process to exit with the specified signal, dumping core
1988 * if appropriate. We bypass the normal tests for masked and caught signals,
1989 * allowing unrecoverable failures to terminate the process without changing
1990 * signal state. Mark the accounting record with the signal termination.
1991 * If dumping core, save the signal number for the debugger. Calls exit and
1992 * does not return.
1993 */
1994 void
1995 sigexit(struct lwp *lp, int sig)
1996 {
1997 struct proc *p = lp->lwp_proc;
1998
1999 p->p_acflag |= AXSIG;
2000 if (sigprop(sig) & SA_CORE) {
2001 lp->lwp_sig = sig;
2002 /*
2003 * Log signals which would cause core dumps
2004 * (Log as LOG_INFO to appease those who don't want
2005 * these messages.)
2006 * XXX : Todo, as well as euid, write out ruid too
2007 */
2008 if (coredump(lp, sig) == 0)
2009 sig |= WCOREFLAG;
2010 if (kern_logsigexit)
2011 log(LOG_INFO,
2012 "pid %d (%s), uid %d: exited on signal %d%s\n",
2013 p->p_pid, p->p_comm,
2014 p->p_ucred ? p->p_ucred->cr_uid : -1,
2015 sig &~ WCOREFLAG,
2016 sig & WCOREFLAG ? " (core dumped)" : "");
2017 }
2018 exit1(W_EXITCODE(0, sig));
2019 /* NOTREACHED */
2020 }
2021
2022 static char corefilename[MAXPATHLEN+1] = {"%N.core"};
2023 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
2024 sizeof(corefilename), "process corefile name format string");
2025
2026 /*
2027 * expand_name(name, uid, pid)
2028 * Expand the name described in corefilename, using name, uid, and pid.
2029 * corefilename is a kprintf-like string, with three format specifiers:
2030 * %N name of process ("name")
2031 * %P process id (pid)
2032 * %U user id (uid)
2033 * For example, "%N.core" is the default; they can be disabled completely
2034 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
2035 * This is controlled by the sysctl variable kern.corefile (see above).
2036 */
2037
2038 static char *
2039 expand_name(const char *name, uid_t uid, pid_t pid)
2040 {
2041 char *temp;
2042 char buf[11]; /* Buffer for pid/uid -- max 4B */
2043 int i, n;
2044 char *format = corefilename;
2045 size_t namelen;
2046
2047 temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
2048 if (temp == NULL)
2049 return NULL;
2050 namelen = strlen(name);
2051 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
2052 int l;
2053 switch (format[i]) {
2054 case '%': /* Format character */
2055 i++;
2056 switch (format[i]) {
2057 case '%':
2058 temp[n++] = '%';
2059 break;
2060 case 'N': /* process name */
2061 if ((n + namelen) > MAXPATHLEN) {
2062 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2063 pid, name, uid, temp, name);
2064 kfree(temp, M_TEMP);
2065 return NULL;
2066 }
2067 memcpy(temp+n, name, namelen);
2068 n += namelen;
2069 break;
2070 case 'P': /* process id */
2071 l = ksprintf(buf, "%u", pid);
2072 if ((n + l) > MAXPATHLEN) {
2073 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2074 pid, name, uid, temp, name);
2075 kfree(temp, M_TEMP);
2076 return NULL;
2077 }
2078 memcpy(temp+n, buf, l);
2079 n += l;
2080 break;
2081 case 'U': /* user id */
2082 l = ksprintf(buf, "%u", uid);
2083 if ((n + l) > MAXPATHLEN) {
2084 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2085 pid, name, uid, temp, name);
2086 kfree(temp, M_TEMP);
2087 return NULL;
2088 }
2089 memcpy(temp+n, buf, l);
2090 n += l;
2091 break;
2092 default:
2093 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
2094 }
2095 break;
2096 default:
2097 temp[n++] = format[i];
2098 }
2099 }
2100 temp[n] = '\0';
2101 return temp;
2102 }
2103
2104 /*
2105 * Dump a process' core. The main routine does some
2106 * policy checking, and creates the name of the coredump;
2107 * then it passes on a vnode and a size limit to the process-specific
2108 * coredump routine if there is one; if there _is not_ one, it returns
2109 * ENOSYS; otherwise it returns the error from the process-specific routine.
2110 *
2111 * The parameter `lp' is the lwp which triggered the coredump.
2112 */
2113
2114 static int
2115 coredump(struct lwp *lp, int sig)
2116 {
2117 struct proc *p = lp->lwp_proc;
2118 struct vnode *vp;
2119 struct ucred *cred = p->p_ucred;
2120 struct flock lf;
2121 struct nlookupdata nd;
2122 struct vattr vattr;
2123 int error, error1;
2124 char *name; /* name of corefile */
2125 off_t limit;
2126
2127 STOPEVENT(p, S_CORE, 0);
2128
2129 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0)
2130 return (EFAULT);
2131
2132 /*
2133 * Note that the bulk of limit checking is done after
2134 * the corefile is created. The exception is if the limit
2135 * for corefiles is 0, in which case we don't bother
2136 * creating the corefile at all. This layout means that
2137 * a corefile is truncated instead of not being created,
2138 * if it is larger than the limit.
2139 */
2140 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
2141 if (limit == 0)
2142 return EFBIG;
2143
2144 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
2145 if (name == NULL)
2146 return (EINVAL);
2147 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
2148 if (error == 0)
2149 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
2150 kfree(name, M_TEMP);
2151 if (error) {
2152 nlookup_done(&nd);
2153 return (error);
2154 }
2155 vp = nd.nl_open_vp;
2156 nd.nl_open_vp = NULL;
2157 nlookup_done(&nd);
2158
2159 vn_unlock(vp);
2160 lf.l_whence = SEEK_SET;
2161 lf.l_start = 0;
2162 lf.l_len = 0;
2163 lf.l_type = F_WRLCK;
2164 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0);
2165 if (error)
2166 goto out2;
2167
2168 /* Don't dump to non-regular files or files with links. */
2169 if (vp->v_type != VREG ||
2170 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) {
2171 error = EFAULT;
2172 goto out1;
2173 }
2174
2175 /* Don't dump to files current user does not own */
2176 if (vattr.va_uid != p->p_ucred->cr_uid) {
2177 error = EFAULT;
2178 goto out1;
2179 }
2180
2181 VATTR_NULL(&vattr);
2182 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2183 vattr.va_size = 0;
2184 VOP_SETATTR(vp, &vattr, cred);
2185 p->p_acflag |= ACORE;
2186 vn_unlock(vp);
2187
2188 error = p->p_sysent->sv_coredump ?
2189 p->p_sysent->sv_coredump(lp, sig, vp, limit) : ENOSYS;
2190
2191 out1:
2192 lf.l_type = F_UNLCK;
2193 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0);
2194 out2:
2195 error1 = vn_close(vp, FWRITE);
2196 if (error == 0)
2197 error = error1;
2198 return (error);
2199 }
2200
2201 /*
2202 * Nonexistent system call-- signal process (may want to handle it).
2203 * Flag error in case process won't see signal immediately (blocked or ignored).
2204 *
2205 * MPALMOSTSAFE
2206 */
2207 /* ARGSUSED */
2208 int
2209 sys_nosys(struct nosys_args *args)
2210 {
2211 lwpsignal(curproc, curthread->td_lwp, SIGSYS);
2212 return (EINVAL);
2213 }
2214
2215 /*
2216 * Send a SIGIO or SIGURG signal to a process or process group using
2217 * stored credentials rather than those of the current process.
2218 */
2219 void
2220 pgsigio(struct sigio *sigio, int sig, int checkctty)
2221 {
2222 if (sigio == NULL)
2223 return;
2224
2225 if (sigio->sio_pgid > 0) {
2226 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
2227 sigio->sio_proc))
2228 ksignal(sigio->sio_proc, sig);
2229 } else if (sigio->sio_pgid < 0) {
2230 struct proc *p;
2231
2232 lockmgr(&sigio->sio_pgrp->pg_lock, LK_EXCLUSIVE);
2233 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
2234 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
2235 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
2236 ksignal(p, sig);
2237 }
2238 lockmgr(&sigio->sio_pgrp->pg_lock, LK_RELEASE);
2239 }
2240 }
2241
2242 static int
2243 filt_sigattach(struct knote *kn)
2244 {
2245 struct proc *p = curproc;
2246
2247 kn->kn_ptr.p_proc = p;
2248 kn->kn_flags |= EV_CLEAR; /* automatically set */
2249
2250 /* XXX lock the proc here while adding to the list? */
2251 knote_insert(&p->p_klist, kn);
2252
2253 return (0);
2254 }
2255
2256 static void
2257 filt_sigdetach(struct knote *kn)
2258 {
2259 struct proc *p = kn->kn_ptr.p_proc;
2260
2261 knote_remove(&p->p_klist, kn);
2262 }
2263
2264 /*
2265 * signal knotes are shared with proc knotes, so we apply a mask to
2266 * the hint in order to differentiate them from process hints. This
2267 * could be avoided by using a signal-specific knote list, but probably
2268 * isn't worth the trouble.
2269 */
2270 static int
2271 filt_signal(struct knote *kn, long hint)
2272 {
2273 if (hint & NOTE_SIGNAL) {
2274 hint &= ~NOTE_SIGNAL;
2275
2276 if (kn->kn_id == hint)
2277 kn->kn_data++;
2278 }
2279 return (kn->kn_data != 0);
2280 }
DragonFly BSD