kernel - Fix signal delivery races
[dragonfly.git] / sys / kern / kern_sig.c
CommitLineData
984263bc
MD
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
984263bc
MD
42#include "opt_ktrace.h"
43
44#include <sys/param.h>
dadab5e9 45#include <sys/systm.h>
984263bc
MD
46#include <sys/kernel.h>
47#include <sys/sysproto.h>
48#include <sys/signalvar.h>
49#include <sys/resourcevar.h>
984263bc
MD
50#include <sys/vnode.h>
51#include <sys/event.h>
52#include <sys/proc.h>
fad57d0e 53#include <sys/nlookup.h>
984263bc
MD
54#include <sys/pioctl.h>
55#include <sys/systm.h>
56#include <sys/acct.h>
57#include <sys/fcntl.h>
167e6ecb 58#include <sys/lock.h>
984263bc
MD
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>
a7231bde 66#include <sys/interrupt.h>
984263bc 67#include <sys/unistd.h>
65957d54 68#include <sys/kern_syscall.h>
7c1212ec 69#include <sys/vkernel.h>
684a93c4
MD
70
71#include <sys/signal2.h>
e43a034f 72#include <sys/thread2.h>
984263bc 73
984263bc
MD
74#include <machine/cpu.h>
75#include <machine/smp.h>
76
7d20a8ff 77static int coredump(struct lwp *, int);
8ebcad3f 78static char *expand_name(const char *, uid_t, pid_t);
552a98ac 79static int dokillpg(int sig, int pgid, int all);
8ebcad3f
MD
80static int sig_ffs(sigset_t *set);
81static int sigprop(int sig);
98c2b8ac 82static void lwp_signotify(struct lwp *lp);
cb973d15 83#ifdef SMP
8ebcad3f 84static void signotify_remote(void *arg);
cb973d15 85#endif
3a59f0f7
DX
86static int kern_sigtimedwait(sigset_t set, siginfo_t *info,
87 struct timespec *timeout);
984263bc
MD
88
89static int filt_sigattach(struct knote *kn);
90static void filt_sigdetach(struct knote *kn);
91static int filt_signal(struct knote *kn, long hint);
92
93struct filterops sig_filtops =
1b478385 94 { 0, filt_sigattach, filt_sigdetach, filt_signal };
984263bc
MD
95
96static int kern_logsigexit = 1;
97SYSCTL_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 */
41c20dac
MD
104#define CANSIGNAL(q, sig) \
105 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \
106 ((sig) == SIGCONT && (q)->p_session == curproc->p_session))
984263bc
MD
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 || \
41c20dac
MD
113 (ruid) == (q)->p_ucred->cr_ruid || \
114 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \
984263bc
MD
115 (ruid) == (q)->p_ucred->cr_uid || \
116 (uc)->cr_uid == (q)->p_ucred->cr_uid)
117
118int sugid_coredump;
119SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
8ebcad3f 120 &sugid_coredump, 0, "Enable coredumping set user/group ID processes");
984263bc
MD
121
122static int do_coredump = 1;
123SYSCTL_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 */
9d63d5c0
MD
138#define SA_CKPT 0x80 /* checkpoint process */
139
984263bc
MD
140
141static 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 */
9d63d5c0
MD
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
984263bc
MD
207};
208
209static __inline int
210sigprop(int sig)
211{
212
213 if (sig > 0 && sig < NSIG)
214 return (sigproptbl[_SIG_IDX(sig)]);
215 return (0);
216}
217
218static __inline int
219sig_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
ac7ea585
VS
229/*
230 * No requirements.
231 */
65957d54
DRJ
232int
233kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact)
984263bc 234{
65957d54
DRJ
235 struct thread *td = curthread;
236 struct proc *p = td->td_proc;
aa6c3de6 237 struct lwp *lp;
41c20dac 238 struct sigacts *ps = p->p_sigacts;
984263bc
MD
239
240 if (sig <= 0 || sig > _SIG_MAXSIG)
241 return (EINVAL);
242
5686ec5a 243 lwkt_gettoken(&p->p_token);
ac7ea585 244
984263bc
MD
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;
7c1212ec
MD
259 if (SIGISMEMBER(ps->ps_sigmailbox, sig))
260 oact->sa_flags |= SA_MAILBOX;
b1b4e5a6 261 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDSTOP)
984263bc 262 oact->sa_flags |= SA_NOCLDSTOP;
b1b4e5a6 263 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDWAIT)
984263bc
MD
264 oact->sa_flags |= SA_NOCLDWAIT;
265 }
266 if (act) {
7c1212ec
MD
267 /*
268 * Check for invalid requests. KILL and STOP cannot be
269 * caught.
270 */
271 if (sig == SIGKILL || sig == SIGSTOP) {
ac7ea585 272 if (act->sa_handler != SIG_DFL) {
5686ec5a 273 lwkt_reltoken(&p->p_token);
7c1212ec 274 return (EINVAL);
ac7ea585 275 }
7c1212ec
MD
276#if 0
277 /* (not needed, SIG_DFL forces action to occur) */
5686ec5a
MD
278 if (act->sa_flags & SA_MAILBOX) {
279 lwkt_reltoken(&p->p_token);
7c1212ec 280 return (EINVAL);
5686ec5a 281 }
7c1212ec
MD
282#endif
283 }
984263bc
MD
284
285 /*
286 * Change setting atomically.
287 */
e43a034f 288 crit_enter();
984263bc
MD
289
290 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
291 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
292 if (act->sa_flags & SA_SIGINFO) {
293 ps->ps_sigact[_SIG_IDX(sig)] =
294 (__sighandler_t *)act->sa_sigaction;
295 SIGADDSET(ps->ps_siginfo, sig);
296 } else {
297 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
298 SIGDELSET(ps->ps_siginfo, sig);
299 }
300 if (!(act->sa_flags & SA_RESTART))
301 SIGADDSET(ps->ps_sigintr, sig);
302 else
303 SIGDELSET(ps->ps_sigintr, sig);
304 if (act->sa_flags & SA_ONSTACK)
305 SIGADDSET(ps->ps_sigonstack, sig);
306 else
307 SIGDELSET(ps->ps_sigonstack, sig);
308 if (act->sa_flags & SA_RESETHAND)
309 SIGADDSET(ps->ps_sigreset, sig);
310 else
311 SIGDELSET(ps->ps_sigreset, sig);
312 if (act->sa_flags & SA_NODEFER)
313 SIGADDSET(ps->ps_signodefer, sig);
314 else
315 SIGDELSET(ps->ps_signodefer, sig);
7c1212ec
MD
316 if (act->sa_flags & SA_MAILBOX)
317 SIGADDSET(ps->ps_sigmailbox, sig);
318 else
319 SIGDELSET(ps->ps_sigmailbox, sig);
984263bc
MD
320 if (sig == SIGCHLD) {
321 if (act->sa_flags & SA_NOCLDSTOP)
b1b4e5a6 322 p->p_sigacts->ps_flag |= PS_NOCLDSTOP;
984263bc 323 else
b1b4e5a6 324 p->p_sigacts->ps_flag &= ~PS_NOCLDSTOP;
984263bc
MD
325 if (act->sa_flags & SA_NOCLDWAIT) {
326 /*
327 * Paranoia: since SA_NOCLDWAIT is implemented
328 * by reparenting the dying child to PID 1 (and
329 * trust it to reap the zombie), PID 1 itself
330 * is forbidden to set SA_NOCLDWAIT.
331 */
332 if (p->p_pid == 1)
b1b4e5a6 333 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
984263bc 334 else
b1b4e5a6 335 p->p_sigacts->ps_flag |= PS_NOCLDWAIT;
8ebcad3f 336 } else {
b1b4e5a6 337 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
8ebcad3f 338 }
984263bc
MD
339 }
340 /*
341 * Set bit in p_sigignore for signals that are set to SIG_IGN,
342 * and for signals set to SIG_DFL where the default is to
343 * ignore. However, don't put SIGCONT in p_sigignore, as we
344 * have to restart the process.
345 */
346 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
347 (sigprop(sig) & SA_IGNORE &&
348 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
349 /* never to be seen again */
350 SIGDELSET(p->p_siglist, sig);
aa6c3de6
SS
351 /*
352 * Remove the signal also from the thread lists.
353 */
354 FOREACH_LWP_IN_PROC(lp, p) {
355 SIGDELSET(lp->lwp_siglist, sig);
356 }
2883d2d8 357 if (sig != SIGCONT) {
84204577 358 /* easier in ksignal */
984263bc 359 SIGADDSET(p->p_sigignore, sig);
2883d2d8 360 }
984263bc
MD
361 SIGDELSET(p->p_sigcatch, sig);
362 } else {
363 SIGDELSET(p->p_sigignore, sig);
364 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
365 SIGDELSET(p->p_sigcatch, sig);
366 else
367 SIGADDSET(p->p_sigcatch, sig);
368 }
984263bc 369
e43a034f 370 crit_exit();
984263bc 371 }
5686ec5a 372 lwkt_reltoken(&p->p_token);
984263bc
MD
373 return (0);
374}
375
984263bc 376int
753fd850 377sys_sigaction(struct sigaction_args *uap)
984263bc
MD
378{
379 struct sigaction act, oact;
1fd87d54 380 struct sigaction *actp, *oactp;
984263bc
MD
381 int error;
382
383 actp = (uap->act != NULL) ? &act : NULL;
384 oactp = (uap->oact != NULL) ? &oact : NULL;
385 if (actp) {
386 error = copyin(uap->act, actp, sizeof(act));
387 if (error)
388 return (error);
389 }
65957d54 390 error = kern_sigaction(uap->sig, actp, oactp);
984263bc
MD
391 if (oactp && !error) {
392 error = copyout(oactp, uap->oact, sizeof(oact));
393 }
394 return (error);
395}
396
984263bc
MD
397/*
398 * Initialize signal state for process 0;
399 * set to ignore signals that are ignored by default.
400 */
401void
8ebcad3f 402siginit(struct proc *p)
984263bc 403{
1fd87d54 404 int i;
984263bc
MD
405
406 for (i = 1; i <= NSIG; i++)
407 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
408 SIGADDSET(p->p_sigignore, i);
409}
410
411/*
412 * Reset signals for an exec of the specified process.
413 */
414void
8ebcad3f 415execsigs(struct proc *p)
984263bc 416{
1fd87d54 417 struct sigacts *ps = p->p_sigacts;
08f2f1bb 418 struct lwp *lp;
1fd87d54 419 int sig;
984263bc 420
aa6c3de6
SS
421 lp = ONLY_LWP_IN_PROC(p);
422
984263bc
MD
423 /*
424 * Reset caught signals. Held signals remain held
425 * through p_sigmask (unless they were caught,
426 * and are now ignored by default).
427 */
428 while (SIGNOTEMPTY(p->p_sigcatch)) {
429 sig = sig_ffs(&p->p_sigcatch);
430 SIGDELSET(p->p_sigcatch, sig);
431 if (sigprop(sig) & SA_IGNORE) {
432 if (sig != SIGCONT)
433 SIGADDSET(p->p_sigignore, sig);
434 SIGDELSET(p->p_siglist, sig);
aa6c3de6 435 SIGDELSET(lp->lwp_siglist, sig);
984263bc
MD
436 }
437 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
438 }
aa6c3de6 439
984263bc
MD
440 /*
441 * Reset stack state to the user stack.
442 * Clear set of signals caught on the signal stack.
443 */
08f2f1bb
SS
444 lp->lwp_sigstk.ss_flags = SS_DISABLE;
445 lp->lwp_sigstk.ss_size = 0;
446 lp->lwp_sigstk.ss_sp = 0;
447 lp->lwp_flag &= ~LWP_ALTSTACK;
984263bc
MD
448 /*
449 * Reset no zombies if child dies flag as Solaris does.
450 */
b1b4e5a6 451 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
984263bc
MD
452}
453
454/*
65957d54 455 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
984263bc
MD
456 *
457 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
e43a034f 458 * p == curproc.
984263bc 459 */
65957d54
DRJ
460int
461kern_sigprocmask(int how, sigset_t *set, sigset_t *oset)
984263bc 462{
65957d54 463 struct thread *td = curthread;
08f2f1bb 464 struct lwp *lp = td->td_lwp;
5686ec5a 465 struct proc *p = td->td_proc;
984263bc
MD
466 int error;
467
5686ec5a 468 lwkt_gettoken(&p->p_token);
ac7ea585 469
984263bc 470 if (oset != NULL)
08f2f1bb 471 *oset = lp->lwp_sigmask;
984263bc
MD
472
473 error = 0;
474 if (set != NULL) {
475 switch (how) {
476 case SIG_BLOCK:
477 SIG_CANTMASK(*set);
08f2f1bb 478 SIGSETOR(lp->lwp_sigmask, *set);
984263bc
MD
479 break;
480 case SIG_UNBLOCK:
08f2f1bb 481 SIGSETNAND(lp->lwp_sigmask, *set);
984263bc
MD
482 break;
483 case SIG_SETMASK:
484 SIG_CANTMASK(*set);
08f2f1bb 485 lp->lwp_sigmask = *set;
984263bc
MD
486 break;
487 default:
488 error = EINVAL;
489 break;
490 }
491 }
ac7ea585 492
5686ec5a 493 lwkt_reltoken(&p->p_token);
ac7ea585 494
984263bc
MD
495 return (error);
496}
497
498/*
3919ced0
MD
499 * sigprocmask()
500 *
501 * MPSAFE
984263bc 502 */
984263bc 503int
753fd850 504sys_sigprocmask(struct sigprocmask_args *uap)
984263bc
MD
505{
506 sigset_t set, oset;
507 sigset_t *setp, *osetp;
508 int error;
509
510 setp = (uap->set != NULL) ? &set : NULL;
511 osetp = (uap->oset != NULL) ? &oset : NULL;
512 if (setp) {
513 error = copyin(uap->set, setp, sizeof(set));
514 if (error)
515 return (error);
516 }
65957d54 517 error = kern_sigprocmask(uap->how, setp, osetp);
984263bc
MD
518 if (osetp && !error) {
519 error = copyout(osetp, uap->oset, sizeof(oset));
520 }
521 return (error);
522}
523
3919ced0
MD
524/*
525 * MPSAFE
526 */
984263bc 527int
65957d54 528kern_sigpending(struct __sigset *set)
984263bc 529{
aa6c3de6 530 struct lwp *lp = curthread->td_lwp;
984263bc 531
aa6c3de6 532 *set = lwp_sigpend(lp);
984263bc 533
984263bc
MD
534 return (0);
535}
536
3919ced0
MD
537/*
538 * MPSAFE
539 */
984263bc 540int
753fd850 541sys_sigpending(struct sigpending_args *uap)
984263bc
MD
542{
543 sigset_t set;
65957d54 544 int error;
984263bc 545
65957d54 546 error = kern_sigpending(&set);
984263bc 547
65957d54
DRJ
548 if (error == 0)
549 error = copyout(&set, uap->set, sizeof(set));
550 return (error);
984263bc 551}
984263bc
MD
552
553/*
554 * Suspend process until signal, providing mask to be set
65957d54 555 * in the meantime.
3919ced0
MD
556 *
557 * MPSAFE
984263bc 558 */
984263bc 559int
65957d54 560kern_sigsuspend(struct __sigset *set)
984263bc 561{
65957d54 562 struct thread *td = curthread;
08f2f1bb 563 struct lwp *lp = td->td_lwp;
65957d54 564 struct proc *p = td->td_proc;
41c20dac 565 struct sigacts *ps = p->p_sigacts;
984263bc
MD
566
567 /*
568 * When returning from sigsuspend, we want
569 * the old mask to be restored after the
570 * signal handler has finished. Thus, we
571 * save it here and mark the sigacts structure
572 * to indicate this.
573 */
08f2f1bb
SS
574 lp->lwp_oldsigmask = lp->lwp_sigmask;
575 lp->lwp_flag |= LWP_OLDMASK;
984263bc 576
65957d54 577 SIG_CANTMASK(*set);
08f2f1bb 578 lp->lwp_sigmask = *set;
65957d54 579 while (tsleep(ps, PCATCH, "pause", 0) == 0)
984263bc
MD
580 /* void */;
581 /* always return EINTR rather than ERESTART... */
582 return (EINTR);
583}
584
65957d54
DRJ
585/*
586 * Note nonstandard calling convention: libc stub passes mask, not
587 * pointer, to save a copyin.
3919ced0
MD
588 *
589 * MPSAFE
65957d54 590 */
984263bc 591int
753fd850 592sys_sigsuspend(struct sigsuspend_args *uap)
984263bc
MD
593{
594 sigset_t mask;
65957d54 595 int error;
984263bc 596
65957d54
DRJ
597 error = copyin(uap->sigmask, &mask, sizeof(mask));
598 if (error)
599 return (error);
600
601 error = kern_sigsuspend(&mask);
602
603 return (error);
984263bc
MD
604}
605
3919ced0
MD
606/*
607 * MPSAFE
608 */
984263bc 609int
65957d54 610kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss)
984263bc 611{
65957d54 612 struct thread *td = curthread;
08f2f1bb 613 struct lwp *lp = td->td_lwp;
65957d54 614 struct proc *p = td->td_proc;
984263bc 615
08f2f1bb
SS
616 if ((lp->lwp_flag & LWP_ALTSTACK) == 0)
617 lp->lwp_sigstk.ss_flags |= SS_DISABLE;
65957d54
DRJ
618
619 if (oss)
08f2f1bb 620 *oss = lp->lwp_sigstk;
65957d54
DRJ
621
622 if (ss) {
623 if (ss->ss_flags & SS_DISABLE) {
08f2f1bb 624 if (lp->lwp_sigstk.ss_flags & SS_ONSTACK)
65957d54 625 return (EINVAL);
08f2f1bb
SS
626 lp->lwp_flag &= ~LWP_ALTSTACK;
627 lp->lwp_sigstk.ss_flags = ss->ss_flags;
65957d54
DRJ
628 } else {
629 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
630 return (ENOMEM);
08f2f1bb
SS
631 lp->lwp_flag |= LWP_ALTSTACK;
632 lp->lwp_sigstk = *ss;
65957d54 633 }
984263bc 634 }
65957d54
DRJ
635
636 return (0);
984263bc 637}
984263bc 638
3919ced0
MD
639/*
640 * MPSAFE
641 */
984263bc 642int
753fd850 643sys_sigaltstack(struct sigaltstack_args *uap)
984263bc 644{
65957d54 645 stack_t ss, oss;
984263bc
MD
646 int error;
647
65957d54
DRJ
648 if (uap->ss) {
649 error = copyin(uap->ss, &ss, sizeof(ss));
650 if (error)
651 return (error);
984263bc 652 }
65957d54
DRJ
653
654 error = kern_sigaltstack(uap->ss ? &ss : NULL,
655 uap->oss ? &oss : NULL);
656
657 if (error == 0 && uap->oss)
658 error = copyout(&oss, uap->oss, sizeof(*uap->oss));
659 return (error);
984263bc
MD
660}
661
662/*
663 * Common code for kill process group/broadcast kill.
664 * cp is calling process.
665 */
8fa76237
MD
666struct killpg_info {
667 int nfound;
668 int sig;
669};
670
671static int killpg_all_callback(struct proc *p, void *data);
672
65957d54 673static int
552a98ac 674dokillpg(int sig, int pgid, int all)
984263bc 675{
8fa76237 676 struct killpg_info info;
41c20dac
MD
677 struct proc *cp = curproc;
678 struct proc *p;
984263bc 679 struct pgrp *pgrp;
8fa76237
MD
680
681 info.nfound = 0;
682 info.sig = sig;
984263bc 683
8ebcad3f 684 if (all) {
984263bc
MD
685 /*
686 * broadcast
687 */
8fa76237 688 allproc_scan(killpg_all_callback, &info);
8ebcad3f
MD
689 } else {
690 if (pgid == 0) {
984263bc
MD
691 /*
692 * zero pgid means send to my process group.
693 */
694 pgrp = cp->p_pgrp;
58c2553a 695 pgref(pgrp);
8ebcad3f 696 } else {
984263bc
MD
697 pgrp = pgfind(pgid);
698 if (pgrp == NULL)
699 return (ESRCH);
700 }
58c2553a
MD
701
702 /*
703 * Must interlock all signals against fork
704 */
167e6ecb 705 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
984263bc 706 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
f026f3b0 707 if (p->p_pid <= 1 ||
416d05d7
SS
708 p->p_stat == SZOMB ||
709 (p->p_flag & P_SYSTEM) ||
f026f3b0 710 !CANSIGNAL(p, sig)) {
984263bc 711 continue;
f026f3b0 712 }
8fa76237 713 ++info.nfound;
984263bc 714 if (sig)
84204577 715 ksignal(p, sig);
984263bc 716 }
167e6ecb 717 lockmgr(&pgrp->pg_lock, LK_RELEASE);
58c2553a 718 pgrel(pgrp);
984263bc 719 }
8fa76237
MD
720 return (info.nfound ? 0 : ESRCH);
721}
722
723static int
724killpg_all_callback(struct proc *p, void *data)
725{
726 struct killpg_info *info = data;
727
728 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) ||
729 p == curproc || !CANSIGNAL(p, info->sig)) {
730 return (0);
731 }
732 ++info->nfound;
733 if (info->sig)
84204577 734 ksignal(p, info->sig);
8fa76237 735 return(0);
984263bc
MD
736}
737
73e40cb2
MD
738/*
739 * Send a general signal to a process or LWPs within that process. Note
740 * that new signals cannot be sent if a process is exiting.
ac7ea585
VS
741 *
742 * No requirements.
73e40cb2 743 */
984263bc 744int
f9366a82 745kern_kill(int sig, pid_t pid, lwpid_t tid)
984263bc 746{
ac7ea585
VS
747 int t;
748
65957d54 749 if ((u_int)sig > _SIG_MAXSIG)
984263bc 750 return (EINVAL);
ac7ea585
VS
751
752 lwkt_gettoken(&proc_token);
753
65957d54 754 if (pid > 0) {
505ba680 755 struct proc *p;
9e758ef5
SW
756 struct lwp *lp = NULL;
757
984263bc 758 /* kill single process */
ac7ea585
VS
759 if ((p = pfind(pid)) == NULL) {
760 lwkt_reltoken(&proc_token);
984263bc 761 return (ESRCH);
ac7ea585 762 }
5686ec5a 763 lwkt_gettoken(&p->p_token);
ac7ea585 764 if (!CANSIGNAL(p, sig)) {
5686ec5a
MD
765 lwkt_reltoken(&p->p_token);
766 PRELE(p);
ac7ea585 767 lwkt_reltoken(&proc_token);
984263bc 768 return (EPERM);
ac7ea585 769 }
73e40cb2
MD
770
771 /*
772 * NOP if the process is exiting. Note that lwpsignal() is
773 * called directly with P_WEXIT set to kill individual LWPs
774 * during exit, which is allowed.
775 */
ac7ea585 776 if (p->p_flag & P_WEXIT) {
5686ec5a
MD
777 lwkt_reltoken(&p->p_token);
778 PRELE(p);
ac7ea585 779 lwkt_reltoken(&proc_token);
73e40cb2 780 return (0);
ac7ea585 781 }
f9366a82 782 if (tid != -1) {
3e291793 783 lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, tid);
ac7ea585 784 if (lp == NULL) {
5686ec5a
MD
785 lwkt_reltoken(&p->p_token);
786 PRELE(p);
ac7ea585 787 lwkt_reltoken(&proc_token);
f9366a82 788 return (ESRCH);
ac7ea585 789 }
f9366a82 790 }
65957d54 791 if (sig)
f9366a82 792 lwpsignal(p, lp, sig);
5686ec5a
MD
793 lwkt_reltoken(&p->p_token);
794 PRELE(p);
ac7ea585 795 lwkt_reltoken(&proc_token);
984263bc
MD
796 return (0);
797 }
5686ec5a 798
f9366a82
SS
799 /*
800 * If we come here, pid is a special broadcast pid.
801 * This doesn't mix with a tid.
802 */
ac7ea585
VS
803 if (tid != -1) {
804 lwkt_reltoken(&proc_token);
f9366a82 805 return (EINVAL);
ac7ea585 806 }
65957d54 807 switch (pid) {
984263bc 808 case -1: /* broadcast signal */
ac7ea585
VS
809 t = (dokillpg(sig, 0, 1));
810 break;
984263bc 811 case 0: /* signal own process group */
ac7ea585
VS
812 t = (dokillpg(sig, 0, 0));
813 break;
984263bc 814 default: /* negative explicit process group */
ac7ea585
VS
815 t = (dokillpg(sig, -pid, 0));
816 break;
984263bc 817 }
ac7ea585
VS
818 lwkt_reltoken(&proc_token);
819 return t;
984263bc
MD
820}
821
984263bc 822int
753fd850 823sys_kill(struct kill_args *uap)
984263bc 824{
65957d54
DRJ
825 int error;
826
f9366a82
SS
827 error = kern_kill(uap->signum, uap->pid, -1);
828 return (error);
829}
830
831int
832sys_lwp_kill(struct lwp_kill_args *uap)
833{
834 int error;
835 pid_t pid = uap->pid;
836
837 /*
838 * A tid is mandatory for lwp_kill(), otherwise
839 * you could simply use kill().
840 */
841 if (uap->tid == -1)
842 return (EINVAL);
843
844 /*
845 * To save on a getpid() function call for intra-process
846 * signals, pid == -1 means current process.
847 */
848 if (pid == -1)
849 pid = curproc->p_pid;
65957d54 850
f9366a82 851 error = kern_kill(uap->signum, pid, uap->tid);
65957d54 852 return (error);
984263bc 853}
984263bc
MD
854
855/*
856 * Send a signal to a process group.
857 */
858void
41c20dac 859gsignal(int pgid, int sig)
984263bc
MD
860{
861 struct pgrp *pgrp;
862
863 if (pgid && (pgrp = pgfind(pgid)))
864 pgsignal(pgrp, sig, 0);
865}
866
867/*
868 * Send a signal to a process group. If checktty is 1,
869 * limit to members which have a controlling terminal.
167e6ecb
MD
870 *
871 * pg_lock interlocks against a fork that might be in progress, to
872 * ensure that the new child process picks up the signal.
984263bc
MD
873 */
874void
8ebcad3f 875pgsignal(struct pgrp *pgrp, int sig, int checkctty)
984263bc 876{
1fd87d54 877 struct proc *p;
984263bc 878
58c2553a
MD
879 /*
880 * Must interlock all signals against fork
881 */
167e6ecb 882 if (pgrp) {
58c2553a 883 pgref(pgrp);
167e6ecb
MD
884 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
885 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
984263bc 886 if (checkctty == 0 || p->p_flag & P_CONTROLT)
84204577 887 ksignal(p, sig);
167e6ecb
MD
888 }
889 lockmgr(&pgrp->pg_lock, LK_RELEASE);
58c2553a 890 pgrel(pgrp);
167e6ecb 891 }
984263bc
MD
892}
893
894/*
04d84fc2
MD
895 * Send a signal caused by a trap to the current lwp. If it will be caught
896 * immediately, deliver it with correct code. Otherwise, post it normally.
897 *
898 * These signals may ONLY be delivered to the specified lwp and may never
899 * be delivered to the process generically.
984263bc
MD
900 */
901void
08f2f1bb 902trapsignal(struct lwp *lp, int sig, u_long code)
984263bc 903{
08f2f1bb 904 struct proc *p = lp->lwp_proc;
dadab5e9 905 struct sigacts *ps = p->p_sigacts;
984263bc 906
7c1212ec
MD
907 /*
908 * If we are a virtual kernel running an emulated user process
909 * context, switch back to the virtual kernel context before
910 * trying to post the signal.
911 */
39005e16 912 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
287ebb09 913 struct trapframe *tf = lp->lwp_md.md_regs;
7c1212ec 914 tf->tf_trapno = 0;
287ebb09 915 vkernel_trap(lp, tf);
7c1212ec
MD
916 }
917
918
984263bc 919 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
08f2f1bb
SS
920 !SIGISMEMBER(lp->lwp_sigmask, sig)) {
921 lp->lwp_ru.ru_nsignals++;
984263bc 922#ifdef KTRACE
08f2f1bb 923 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
9fb04d14 924 ktrpsig(lp, sig, ps->ps_sigact[_SIG_IDX(sig)],
08f2f1bb 925 &lp->lwp_sigmask, code);
984263bc
MD
926#endif
927 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
08f2f1bb
SS
928 &lp->lwp_sigmask, code);
929 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
984263bc 930 if (!SIGISMEMBER(ps->ps_signodefer, sig))
08f2f1bb 931 SIGADDSET(lp->lwp_sigmask, sig);
984263bc
MD
932 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
933 /*
65957d54 934 * See kern_sigaction() for origin of this code.
984263bc
MD
935 */
936 SIGDELSET(p->p_sigcatch, sig);
937 if (sig != SIGCONT &&
938 sigprop(sig) & SA_IGNORE)
939 SIGADDSET(p->p_sigignore, sig);
940 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
941 }
942 } else {
7d20a8ff
SS
943 lp->lwp_code = code; /* XXX for core dump/debugger */
944 lp->lwp_sig = sig; /* XXX to verify code */
7278a846 945 lwpsignal(p, lp, sig);
984263bc
MD
946 }
947}
948
1699b0b8 949/*
58c2553a
MD
950 * Find a suitable lwp to deliver the signal to. Returns NULL if all
951 * lwps hold the signal blocked.
1699b0b8 952 *
58c2553a 953 * Caller must hold p->p_token.
1699b0b8
SS
954 */
955static struct lwp *
956find_lwp_for_signal(struct proc *p, int sig)
957{
958 struct lwp *lp;
959 struct lwp *run, *sleep, *stop;
960
961 /*
962 * If the running/preempted thread belongs to the proc to which
963 * the signal is being delivered and this thread does not block
964 * the signal, then we can avoid a context switch by delivering
965 * the signal to this thread, because it will return to userland
966 * soon anyways.
967 */
968 lp = lwkt_preempted_proc();
58c2553a
MD
969 if (lp != NULL && lp->lwp_proc == p &&
970 !SIGISMEMBER(lp->lwp_sigmask, sig)) {
1699b0b8 971 return (lp);
58c2553a 972 }
1699b0b8
SS
973
974 run = sleep = stop = NULL;
975 FOREACH_LWP_IN_PROC(lp, p) {
976 /*
977 * If the signal is being blocked by the lwp, then this
978 * lwp is not eligible for receiving the signal.
979 */
980 if (SIGISMEMBER(lp->lwp_sigmask, sig))
981 continue;
982
983 switch (lp->lwp_stat) {
984 case LSRUN:
985 run = lp;
986 break;
987
988 case LSSTOP:
989 stop = lp;
990 break;
991
992 case LSSLEEP:
993 if (lp->lwp_flag & LWP_SINTR)
994 sleep = lp;
995 break;
996 }
997 }
998
999 if (run != NULL)
1000 return (run);
1001 else if (sleep != NULL)
1002 return (sleep);
1003 else
1004 return (stop);
1005}
1006
984263bc
MD
1007/*
1008 * Send the signal to the process. If the signal has an action, the action
1009 * is usually performed by the target process rather than the caller; we add
1010 * the signal to the set of pending signals for the process.
1011 *
1012 * Exceptions:
1013 * o When a stop signal is sent to a sleeping process that takes the
1014 * default action, the process is stopped without awakening it.
1015 * o SIGCONT restarts stopped processes (or puts them back to sleep)
1016 * regardless of the signal action (eg, blocked or ignored).
1017 *
1018 * Other ignored signals are discarded immediately.
ac7ea585 1019 *
8582ec21
MD
1020 * If the caller wishes to call this function from a hard code section the
1021 * caller must already hold p->p_token (see kern_clock.c).
1022 *
ac7ea585 1023 * No requirements.
984263bc
MD
1024 */
1025void
84204577 1026ksignal(struct proc *p, int sig)
984263bc 1027{
7278a846
SS
1028 lwpsignal(p, NULL, sig);
1029}
1030
1031/*
1032 * The core for ksignal. lp may be NULL, then a suitable thread
1033 * will be chosen. If not, lp MUST be a member of p.
ac7ea585 1034 *
8582ec21
MD
1035 * If the caller wishes to call this function from a hard code section the
1036 * caller must already hold p->p_token.
1037 *
ac7ea585 1038 * No requirements.
7278a846
SS
1039 */
1040void
1041lwpsignal(struct proc *p, struct lwp *lp, int sig)
1042{
e43a034f 1043 int prop;
cb973d15 1044 sig_t action;
984263bc
MD
1045
1046 if (sig > _SIG_MAXSIG || sig <= 0) {
7278a846
SS
1047 kprintf("lwpsignal: signal %d\n", sig);
1048 panic("lwpsignal signal number");
984263bc
MD
1049 }
1050
7278a846
SS
1051 KKASSERT(lp == NULL || lp->lwp_proc == p);
1052
58c2553a 1053 PHOLD(p);
5686ec5a 1054 lwkt_gettoken(&p->p_token);
ac7ea585 1055
984263bc
MD
1056 prop = sigprop(sig);
1057
1058 /*
1059 * If proc is traced, always give parent a chance;
1060 * if signal event is tracked by procfs, give *that*
1061 * a chance, as well.
1062 */
8ebcad3f 1063 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) {
984263bc 1064 action = SIG_DFL;
8ebcad3f 1065 } else {
984263bc 1066 /*
73e40cb2
MD
1067 * Do not try to deliver signals to an exiting lwp. Note
1068 * that we must still deliver the signal if P_WEXIT is set
1069 * in the process flags.
984263bc 1070 */
ac7ea585 1071 if (lp && (lp->lwp_flag & LWP_WEXIT)) {
5686ec5a 1072 lwkt_reltoken(&p->p_token);
58c2553a 1073 PRELE(p);
e3161323 1074 return;
ac7ea585 1075 }
e3161323
MD
1076
1077 /*
8f433481 1078 * If the signal is being ignored, then we forget about
e3161323
MD
1079 * it immediately. NOTE: We don't set SIGCONT in p_sigignore,
1080 * and if it is set to SIG_IGN, action will be SIG_DFL here.
1081 */
ac7ea585 1082 if (SIGISMEMBER(p->p_sigignore, sig)) {
ac310c3a
SG
1083 /*
1084 * Even if a signal is set SIG_IGN, it may still be
1085 * lurking in a kqueue.
1086 */
1087 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
5686ec5a 1088 lwkt_reltoken(&p->p_token);
58c2553a 1089 PRELE(p);
984263bc 1090 return;
ac7ea585 1091 }
1699b0b8 1092 if (SIGISMEMBER(p->p_sigcatch, sig))
984263bc
MD
1093 action = SIG_CATCH;
1094 else
1095 action = SIG_DFL;
1096 }
1097
344ad853
MD
1098 /*
1099 * If continuing, clear any pending STOP signals.
1100 */
984263bc
MD
1101 if (prop & SA_CONT)
1102 SIG_STOPSIGMASK(p->p_siglist);
9d63d5c0 1103
984263bc
MD
1104 if (prop & SA_STOP) {
1105 /*
1106 * If sending a tty stop signal to a member of an orphaned
1107 * process group, discard the signal here if the action
1108 * is default; don't stop the process below if sleeping,
1109 * and don't clear any pending SIGCONT.
1110 */
1111 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
8ebcad3f 1112 action == SIG_DFL) {
5686ec5a 1113 lwkt_reltoken(&p->p_token);
58c2553a 1114 PRELE(p);
984263bc 1115 return;
8ebcad3f 1116 }
984263bc 1117 SIG_CONTSIGMASK(p->p_siglist);
cc162105 1118 p->p_flag &= ~P_CONTINUED;
984263bc 1119 }
e43a034f
MD
1120
1121 crit_enter();
1122
1699b0b8 1123 if (p->p_stat == SSTOP) {
984263bc 1124 /*
04d84fc2
MD
1125 * Nobody can handle this signal, add it to the lwp or
1126 * process pending list
344ad853 1127 */
04d84fc2
MD
1128 if (lp)
1129 SIGADDSET(lp->lwp_siglist, sig);
1130 else
1131 SIGADDSET(p->p_siglist, sig);
344ad853 1132
344ad853
MD
1133 /*
1134 * If the process is stopped and is being traced, then no
1135 * further action is necessary.
984263bc
MD
1136 */
1137 if (p->p_flag & P_TRACED)
1138 goto out;
1139
1140 /*
344ad853
MD
1141 * If the process is stopped and receives a KILL signal,
1142 * make the process runnable.
984263bc 1143 */
9a379a4a
SS
1144 if (sig == SIGKILL) {
1145 proc_unstop(p);
7278a846 1146 goto active_process;
9a379a4a 1147 }
984263bc 1148
344ad853
MD
1149 /*
1150 * If the process is stopped and receives a CONT signal,
1151 * then try to make the process runnable again.
1152 */
984263bc
MD
1153 if (prop & SA_CONT) {
1154 /*
1155 * If SIGCONT is default (or ignored), we continue the
1156 * process but don't leave the signal in p_siglist, as
1157 * it has no further action. If SIGCONT is held, we
1158 * continue the process and leave the signal in
1159 * p_siglist. If the process catches SIGCONT, let it
344ad853 1160 * handle the signal itself.
984263bc 1161 */
1699b0b8 1162 /* XXX what if the signal is being held blocked? */
cc162105
PA
1163 p->p_flag |= P_CONTINUED;
1164 wakeup(p->p_pptr);
984263bc
MD
1165 if (action == SIG_DFL)
1166 SIGDELSET(p->p_siglist, sig);
9a379a4a 1167 proc_unstop(p);
984263bc 1168 if (action == SIG_CATCH)
1699b0b8 1169 goto active_process;
9a379a4a 1170 goto out;
344ad853
MD
1171 }
1172
1173 /*
1174 * If the process is stopped and receives another STOP
1175 * signal, we do not need to stop it again. If we did
1176 * the shell could get confused.
6ed57d3d
SS
1177 *
1178 * However, if the current/preempted lwp is part of the
1179 * process receiving the signal, we need to keep it,
1180 * so that this lwp can stop in issignal() later, as
1181 * we don't want to wait until it reaches userret!
344ad853
MD
1182 */
1183 if (prop & SA_STOP) {
7278a846
SS
1184 if (lwkt_preempted_proc() == NULL ||
1185 lwkt_preempted_proc()->lwp_proc != p)
6ed57d3d 1186 SIGDELSET(p->p_siglist, sig);
984263bc
MD
1187 }
1188
1189 /*
1699b0b8
SS
1190 * Otherwise the process is stopped and it received some
1191 * signal, which does not change its stopped state.
7278a846
SS
1192 *
1193 * We have to select one thread to set LWP_BREAKTSLEEP,
1194 * so that the current signal will break the sleep
1195 * as soon as a SA_CONT signal will unstop the process.
984263bc 1196 */
7278a846
SS
1197 if (lp == NULL)
1198 lp = find_lwp_for_signal(p, sig);
1199 if (lp != NULL &&
1200 (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP))
1201 lp->lwp_flag |= LWP_BREAKTSLEEP;
984263bc 1202 goto out;
1699b0b8
SS
1203
1204 /* NOTREACHED */
344ad853 1205 }
1699b0b8
SS
1206 /* else not stopped */
1207active_process:
1208
04d84fc2
MD
1209 /*
1210 * Never deliver a lwp-specific signal to a random lwp.
1211 */
1212 if (lp == NULL) {
7278a846 1213 lp = find_lwp_for_signal(p, sig);
04d84fc2
MD
1214 if (lp && SIGISMEMBER(lp->lwp_sigmask, sig))
1215 lp = NULL;
1216 }
344ad853
MD
1217
1218 /*
04d84fc2
MD
1219 * Deliver to the process generically if (1) the signal is being
1220 * sent to any thread or (2) we could not find a thread to deliver
1221 * it to.
344ad853 1222 */
04d84fc2 1223 if (lp == NULL) {
1699b0b8
SS
1224 SIGADDSET(p->p_siglist, sig);
1225 goto out;
1226 }
344ad853 1227
04d84fc2
MD
1228 /*
1229 * Deliver to a specific LWP whether it masks it or not. It will
1230 * not be dispatched if masked but we must still deliver it.
1231 */
1699b0b8
SS
1232 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
1233 (p->p_flag & P_TRACED) == 0) {
1234 p->p_nice = NZERO;
1235 }
344ad853 1236
1699b0b8
SS
1237 /*
1238 * If the process receives a STOP signal which indeed needs to
1239 * stop the process, do so. If the process chose to catch the
1240 * signal, it will be treated like any other signal.
1241 */
1242 if ((prop & SA_STOP) && action == SIG_DFL) {
1243 /*
1244 * If a child holding parent blocked, stopping
1245 * could cause deadlock. Take no action at this
1246 * time.
1247 */
1248 if (p->p_flag & P_PPWAIT) {
1249 SIGADDSET(p->p_siglist, sig);
1250 goto out;
1251 }
1252
1253 /*
1254 * Do not actually try to manipulate the process, but simply
1255 * stop it. Lwps will stop as soon as they safely can.
1256 */
1257 p->p_xstat = sig;
f33e8653 1258 proc_stop(p);
1699b0b8 1259 goto out;
984263bc 1260 }
1699b0b8 1261
344ad853 1262 /*
1699b0b8 1263 * If it is a CONT signal with default action, just ignore it.
344ad853 1264 */
1699b0b8
SS
1265 if ((prop & SA_CONT) && action == SIG_DFL)
1266 goto out;
1267
1268 /*
1269 * Mark signal pending at this specific thread.
1270 */
1271 SIGADDSET(lp->lwp_siglist, sig);
1272
7278a846
SS
1273 lwp_signotify(lp);
1274
1275out:
5686ec5a 1276 lwkt_reltoken(&p->p_token);
58c2553a 1277 PRELE(p);
7278a846
SS
1278 crit_exit();
1279}
1280
98c2b8ac 1281/*
5686ec5a 1282 * p->p_token must be held
98c2b8ac
MD
1283 */
1284static void
7278a846
SS
1285lwp_signotify(struct lwp *lp)
1286{
5686ec5a 1287 ASSERT_LWKT_TOKEN_HELD(&lp->lwp_proc->p_token);
7278a846 1288 crit_enter();
98c2b8ac 1289
7278a846 1290 if (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP) {
1699b0b8
SS
1291 /*
1292 * Thread is in tsleep.
1293 */
1294
1295 /*
1296 * If the thread is sleeping uninterruptibly
1297 * we can't interrupt the sleep... the signal will
1298 * be noticed when the lwp returns through
1299 * trap() or syscall().
7278a846 1300 *
1699b0b8
SS
1301 * Otherwise the signal can interrupt the sleep.
1302 *
1303 * If the process is traced, the lwp will handle the
1304 * tracing in issignal() when it returns to userland.
1305 */
7278a846
SS
1306 if (lp->lwp_flag & LWP_SINTR) {
1307 /*
1308 * Make runnable and break out of any tsleep as well.
1309 */
1310 lp->lwp_flag |= LWP_BREAKTSLEEP;
1311 setrunnable(lp);
1312 }
1699b0b8
SS
1313 } else {
1314 /*
1315 * Otherwise the thread is running
1316 *
1317 * LSRUN does nothing with the signal, other than kicking
1318 * ourselves if we are running.
1319 * SZOMB and SIDL mean that it will either never be noticed,
1320 * or noticed very soon.
1321 *
1322 * Note that lwp_thread may be NULL or may not be completely
1323 * initialized if the process is in the SIDL or SZOMB state.
1324 *
1325 * For SMP we may have to forward the request to another cpu.
1326 * YYY the MP lock prevents the target process from moving
1327 * to another cpu, see kern/kern_switch.c
1328 *
1329 * If the target thread is waiting on its message port,
1330 * wakeup the target thread so it can check (or ignore)
1331 * the new signal. YYY needs cleanup.
1332 */
1333 if (lp == lwkt_preempted_proc()) {
1334 signotify();
1335 } else if (lp->lwp_stat == LSRUN) {
1336 struct thread *td = lp->lwp_thread;
f64b567c 1337 struct proc *p __debugvar = lp->lwp_proc;
1699b0b8
SS
1338
1339 KASSERT(td != NULL,
1340 ("pid %d/%d NULL lwp_thread stat %d flags %08x/%08x",
1341 p->p_pid, lp->lwp_tid, lp->lwp_stat,
1342 p->p_flag, lp->lwp_flag));
1343
a22c590e
MD
1344 /*
1345 * To prevent a MP race with TDF_SINTR we must
1346 * schedule the thread on the correct cpu.
1347 */
1699b0b8 1348#ifdef SMP
c5d0ecf8
MD
1349 if (td->td_gd != mycpu) {
1350 LWPHOLD(lp);
1699b0b8 1351 lwkt_send_ipiq(td->td_gd, signotify_remote, lp);
c5d0ecf8 1352 } else
1699b0b8 1353#endif
a22c590e 1354 if (td->td_flags & TDF_SINTR)
1699b0b8
SS
1355 lwkt_schedule(td);
1356 }
1357 }
e43a034f 1358 crit_exit();
984263bc
MD
1359}
1360
cb973d15
MD
1361#ifdef SMP
1362
1363/*
1364 * This function is called via an IPI. We will be in a critical section but
d041353d
MD
1365 * the MP lock will NOT be held. The passed lp will be held.
1366 *
1367 * We must essentially repeat the code at the end of lwp_signotify(),
1368 * in particular rechecking all races. If we are still not on the
1369 * correct cpu we leave the lwp ref intact and continue the chase.
1370 *
1371 * XXX this may still not be entirely correct, since we are checking
1372 * lwp_stat asynchronously.
cb973d15
MD
1373 */
1374static void
1375signotify_remote(void *arg)
1376{
553ea3c8 1377 struct lwp *lp = arg;
d041353d 1378 thread_t td;
60be1d11 1379
553ea3c8 1380 if (lp == lwkt_preempted_proc()) {
235957ed 1381 signotify();
d041353d
MD
1382 } else if (lp->lwp_stat == LSRUN) {
1383 /*
1384 * To prevent a MP race with TDF_SINTR we must
1385 * schedule the thread on the correct cpu.
1386 */
1387 td = lp->lwp_thread;
1388 if (td->td_gd != mycpu) {
1389 lwkt_send_ipiq(td->td_gd, signotify_remote, lp);
1390 return;
1391 /* NOT REACHED */
1392 }
a22c590e 1393 if (td->td_flags & TDF_SINTR)
60be1d11
MD
1394 lwkt_schedule(td);
1395 }
c5d0ecf8 1396 LWPRELE(lp);
cb973d15
MD
1397}
1398
1399#endif
1400
98c2b8ac 1401/*
5686ec5a 1402 * Caller must hold p->p_token
98c2b8ac 1403 */
9a379a4a 1404void
f33e8653 1405proc_stop(struct proc *p)
9a379a4a 1406{
f33e8653 1407 struct lwp *lp;
7278a846 1408
5686ec5a 1409 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
98c2b8ac
MD
1410 crit_enter();
1411
7278a846 1412 /* If somebody raced us, be happy with it */
98c2b8ac
MD
1413 if (p->p_stat == SSTOP || p->p_stat == SZOMB) {
1414 crit_exit();
7278a846 1415 return;
98c2b8ac 1416 }
9a379a4a 1417 p->p_stat = SSTOP;
7278a846 1418
7278a846
SS
1419 FOREACH_LWP_IN_PROC(lp, p) {
1420 switch (lp->lwp_stat) {
1421 case LSSTOP:
1422 /*
1423 * Do nothing, we are already counted in
1424 * p_nstopped.
1425 */
1426 break;
1427
1428 case LSSLEEP:
1429 /*
1430 * We're sleeping, but we will stop before
1431 * returning to userspace, so count us
f33e8653
SS
1432 * as stopped as well. We set LWP_WSTOP
1433 * to signal the lwp that it should not
1434 * increase p_nstopped when reaching tstop().
7278a846 1435 */
f33e8653
SS
1436 if ((lp->lwp_flag & LWP_WSTOP) == 0) {
1437 lp->lwp_flag |= LWP_WSTOP;
1438 ++p->p_nstopped;
1439 }
7278a846
SS
1440 break;
1441
1442 case LSRUN:
7278a846 1443 /*
f33e8653
SS
1444 * We might notify ourself, but that's not
1445 * a problem.
7278a846 1446 */
f33e8653 1447 lwp_signotify(lp);
7278a846
SS
1448 break;
1449 }
1450 }
1451
f33e8653
SS
1452 if (p->p_nstopped == p->p_nthreads) {
1453 p->p_flag &= ~P_WAITED;
1454 wakeup(p->p_pptr);
1455 if ((p->p_pptr->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1456 ksignal(p->p_pptr, SIGCHLD);
1457 }
1458 crit_exit();
9a379a4a
SS
1459}
1460
98c2b8ac
MD
1461/*
1462 * Caller must hold proc_token
1463 */
9a379a4a
SS
1464void
1465proc_unstop(struct proc *p)
1466{
7278a846 1467 struct lwp *lp;
9a379a4a 1468
5686ec5a 1469 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
98c2b8ac
MD
1470 crit_enter();
1471
1472 if (p->p_stat != SSTOP) {
1473 crit_exit();
7278a846 1474 return;
98c2b8ac 1475 }
f33e8653 1476
9a379a4a 1477 p->p_stat = SACTIVE;
7278a846
SS
1478
1479 FOREACH_LWP_IN_PROC(lp, p) {
1480 switch (lp->lwp_stat) {
1481 case LSRUN:
1482 /*
1483 * Uh? Not stopped? Well, I guess that's okay.
1484 */
1485 if (bootverbose)
1486 kprintf("proc_unstop: lwp %d/%d not sleeping\n",
1487 p->p_pid, lp->lwp_tid);
1488 break;
1489
7278a846
SS
1490 case LSSLEEP:
1491 /*
1492 * Still sleeping. Don't bother waking it up.
f33e8653
SS
1493 * However, if this thread was counted as
1494 * stopped, undo this.
1495 *
1496 * Nevertheless we call setrunnable() so that it
1497 * will wake up in case a signal or timeout arrived
1498 * in the meantime.
7278a846 1499 */
f33e8653 1500 if (lp->lwp_flag & LWP_WSTOP) {
a5ff9d37 1501 lp->lwp_flag &= ~LWP_WSTOP;
f33e8653
SS
1502 --p->p_nstopped;
1503 } else {
1504 if (bootverbose)
1505 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n",
1506 p->p_pid, lp->lwp_tid);
1507 }
1508 /* FALLTHROUGH */
1509
1510 case LSSTOP:
1511 setrunnable(lp);
7278a846 1512 break;
f33e8653 1513
7278a846
SS
1514 }
1515 }
f33e8653 1516 crit_exit();
9a379a4a
SS
1517}
1518
ac7ea585
VS
1519/*
1520 * No requirements.
ac7ea585 1521 */
3a59f0f7
DX
1522static int
1523kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout)
1524{
1525 sigset_t savedmask, set;
1526 struct proc *p = curproc;
08f2f1bb 1527 struct lwp *lp = curthread->td_lwp;
3a59f0f7
DX
1528 int error, sig, hz, timevalid = 0;
1529 struct timespec rts, ets, ts;
1530 struct timeval tv;
1531
1532 error = 0;
1533 sig = 0;
c077b601
MD
1534 ets.tv_sec = 0; /* silence compiler warning */
1535 ets.tv_nsec = 0; /* silence compiler warning */
3a59f0f7 1536 SIG_CANTMASK(waitset);
08f2f1bb 1537 savedmask = lp->lwp_sigmask;
3a59f0f7
DX
1538
1539 if (timeout) {
f8c41806
DX
1540 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 &&
1541 timeout->tv_nsec < 1000000000) {
3a59f0f7
DX
1542 timevalid = 1;
1543 getnanouptime(&rts);
1544 ets = rts;
1545 timespecadd(&ets, timeout);
1546 }
1547 }
1548
1549 for (;;) {
aa6c3de6 1550 set = lwp_sigpend(lp);
3a59f0f7
DX
1551 SIGSETAND(set, waitset);
1552 if ((sig = sig_ffs(&set)) != 0) {
08f2f1bb
SS
1553 SIGFILLSET(lp->lwp_sigmask);
1554 SIGDELSET(lp->lwp_sigmask, sig);
1555 SIG_CANTMASK(lp->lwp_sigmask);
e473f776 1556 sig = issignal(lp, 1);
3a59f0f7
DX
1557 /*
1558 * It may be a STOP signal, in the case, issignal
1559 * returns 0, because we may stop there, and new
1560 * signal can come in, we should restart if we got
1561 * nothing.
1562 */
1563 if (sig == 0)
1564 continue;
1565 else
1566 break;
1567 }
1568
1569 /*
1570 * Previous checking got nothing, and we retried but still
1571 * got nothing, we should return the error status.
1572 */
1573 if (error)
1574 break;
1575
1576 /*
1577 * POSIX says this must be checked after looking for pending
1578 * signals.
1579 */
1580 if (timeout) {
c077b601 1581 if (timevalid == 0) {
3a59f0f7
DX
1582 error = EINVAL;
1583 break;
1584 }
1585 getnanouptime(&rts);
1586 if (timespeccmp(&rts, &ets, >=)) {
1587 error = EAGAIN;
1588 break;
1589 }
1590 ts = ets;
1591 timespecsub(&ts, &rts);
1592 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1593 hz = tvtohz_high(&tv);
5686ec5a 1594 } else {
3a59f0f7 1595 hz = 0;
5686ec5a 1596 }
3a59f0f7 1597
08f2f1bb
SS
1598 lp->lwp_sigmask = savedmask;
1599 SIGSETNAND(lp->lwp_sigmask, waitset);
b1b4e5a6
SS
1600 /*
1601 * We won't ever be woken up. Instead, our sleep will
1602 * be broken in lwpsignal().
1603 */
3a59f0f7
DX
1604 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz);
1605 if (timeout) {
1606 if (error == ERESTART) {
1607 /* can not restart a timeout wait. */
1608 error = EINTR;
1609 } else if (error == EAGAIN) {
1610 /* will calculate timeout by ourself. */
1611 error = 0;
1612 }
1613 }
1614 /* Retry ... */
1615 }
1616
08f2f1bb 1617 lp->lwp_sigmask = savedmask;
3a59f0f7
DX
1618 if (sig) {
1619 error = 0;
1620 bzero(info, sizeof(*info));
1621 info->si_signo = sig;
aa6c3de6 1622 lwp_delsig(lp, sig); /* take the signal! */
1e1bd00b 1623
2883d2d8 1624 if (sig == SIGKILL) {
b276424c 1625 sigexit(lp, sig);
2883d2d8
MD
1626 /* NOT REACHED */
1627 }
3a59f0f7 1628 }
ac7ea585 1629
3a59f0f7
DX
1630 return (error);
1631}
1632
3919ced0
MD
1633/*
1634 * MPALMOSTSAFE
1635 */
3a59f0f7 1636int
753fd850 1637sys_sigtimedwait(struct sigtimedwait_args *uap)
3a59f0f7
DX
1638{
1639 struct timespec ts;
1640 struct timespec *timeout;
1641 sigset_t set;
1642 siginfo_t info;
1643 int error;
1644
1645 if (uap->timeout) {
1646 error = copyin(uap->timeout, &ts, sizeof(ts));
1647 if (error)
1648 return (error);
1649 timeout = &ts;
1650 } else {
1651 timeout = NULL;
1652 }
1653 error = copyin(uap->set, &set, sizeof(set));
1654 if (error)
1655 return (error);
1656 error = kern_sigtimedwait(set, &info, timeout);
1657 if (error)
1658 return (error);
1659 if (uap->info)
1660 error = copyout(&info, uap->info, sizeof(info));
1661 /* Repost if we got an error. */
7278a846
SS
1662 /*
1663 * XXX lwp
1664 *
1665 * This could transform a thread-specific signal to another
1666 * thread / process pending signal.
1667 */
3919ced0 1668 if (error) {
84204577 1669 ksignal(curproc, info.si_signo);
3919ced0 1670 } else {
3a59f0f7 1671 uap->sysmsg_result = info.si_signo;
3919ced0 1672 }
3a59f0f7
DX
1673 return (error);
1674}
1675
3919ced0
MD
1676/*
1677 * MPALMOSTSAFE
1678 */
3a59f0f7 1679int
753fd850 1680sys_sigwaitinfo(struct sigwaitinfo_args *uap)
3a59f0f7
DX
1681{
1682 siginfo_t info;
1683 sigset_t set;
1684 int error;
1685
1686 error = copyin(uap->set, &set, sizeof(set));
1687 if (error)
1688 return (error);
1689 error = kern_sigtimedwait(set, &info, NULL);
1690 if (error)
1691 return (error);
1692 if (uap->info)
1693 error = copyout(&info, uap->info, sizeof(info));
1694 /* Repost if we got an error. */
7278a846
SS
1695 /*
1696 * XXX lwp
1697 *
1698 * This could transform a thread-specific signal to another
1699 * thread / process pending signal.
1700 */
3919ced0 1701 if (error) {
84204577 1702 ksignal(curproc, info.si_signo);
3919ced0 1703 } else {
3a59f0f7 1704 uap->sysmsg_result = info.si_signo;
3919ced0 1705 }
3a59f0f7
DX
1706 return (error);
1707}
1708
a94976ad
MD
1709/*
1710 * If the current process has received a signal that would interrupt a
1711 * system call, return EINTR or ERESTART as appropriate.
1712 */
1713int
08f2f1bb 1714iscaught(struct lwp *lp)
a94976ad 1715{
08f2f1bb 1716 struct proc *p = lp->lwp_proc;
a94976ad
MD
1717 int sig;
1718
1719 if (p) {
08f2f1bb 1720 if ((sig = CURSIG(lp)) != 0) {
a94976ad
MD
1721 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1722 return (EINTR);
1723 return (ERESTART);
1724 }
1725 }
1726 return(EWOULDBLOCK);
1727}
1728
984263bc
MD
1729/*
1730 * If the current process has received a signal (should be caught or cause
1731 * termination, should interrupt current syscall), return the signal number.
1732 * Stop signals with default action are processed immediately, then cleared;
1733 * they aren't returned. This is checked after each entry to the system for
1734 * a syscall or trap (though this can usually be done without calling issignal
5686ec5a 1735 * by checking the pending signal masks in the CURSIG macro).
984263bc 1736 *
5686ec5a
MD
1737 * This routine is called via CURSIG/__cursig. We will acquire and release
1738 * p->p_token but if the caller needs to interlock the test the caller must
1739 * also hold p->p_token.
bf189c26 1740 *
984263bc
MD
1741 * while (sig = CURSIG(curproc))
1742 * postsig(sig);
5686ec5a
MD
1743 *
1744 * MPSAFE
984263bc
MD
1745 */
1746int
e473f776 1747issignal(struct lwp *lp, int maytrace)
984263bc 1748{
08f2f1bb 1749 struct proc *p = lp->lwp_proc;
984263bc 1750 sigset_t mask;
1fd87d54 1751 int sig, prop;
984263bc 1752
5686ec5a 1753 lwkt_gettoken(&p->p_token);
98c2b8ac 1754
984263bc
MD
1755 for (;;) {
1756 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
1757
e473f776
SS
1758 /*
1759 * If this process is supposed to stop, stop this thread.
1760 */
1761 if (p->p_stat == SSTOP)
1762 tstop();
1763
aa6c3de6 1764 mask = lwp_sigpend(lp);
08f2f1bb 1765 SIGSETNAND(mask, lp->lwp_sigmask);
984263bc
MD
1766 if (p->p_flag & P_PPWAIT)
1767 SIG_STOPSIGMASK(mask);
1699b0b8 1768 if (SIGISEMPTY(mask)) { /* no signal to send */
5686ec5a 1769 lwkt_reltoken(&p->p_token);
984263bc 1770 return (0);
bf189c26 1771 }
984263bc
MD
1772 sig = sig_ffs(&mask);
1773
1774 STOPEVENT(p, S_SIG, sig);
1775
1776 /*
1777 * We should see pending but ignored signals
1778 * only if P_TRACED was on when they were posted.
1779 */
1780 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
aa6c3de6 1781 lwp_delsig(lp, sig);
984263bc
MD
1782 continue;
1783 }
e473f776 1784 if (maytrace && (p->p_flag & P_TRACED) && (p->p_flag & P_PPWAIT) == 0) {
984263bc 1785 /*
344ad853
MD
1786 * If traced, always stop, and stay stopped until
1787 * released by the parent.
1788 *
164b8401 1789 * NOTE: SSTOP may get cleared during the loop,
344ad853
MD
1790 * but we do not re-notify the parent if we have
1791 * to loop several times waiting for the parent
1792 * to let us continue.
164b8401
SS
1793 *
1794 * XXX not sure if this is still true
984263bc
MD
1795 */
1796 p->p_xstat = sig;
f33e8653 1797 proc_stop(p);
984263bc 1798 do {
9a379a4a 1799 tstop();
344ad853 1800 } while (!trace_req(p) && (p->p_flag & P_TRACED));
984263bc
MD
1801
1802 /*
1803 * If parent wants us to take the signal,
1804 * then it will leave it in p->p_xstat;
1805 * otherwise we just look for signals again.
1806 */
aa6c3de6 1807 lwp_delsig(lp, sig); /* clear old signal */
984263bc
MD
1808 sig = p->p_xstat;
1809 if (sig == 0)
1810 continue;
1811
1812 /*
1813 * Put the new signal into p_siglist. If the
1814 * signal is being masked, look for other signals.
1699b0b8
SS
1815 *
1816 * XXX lwp might need a call to ksignal()
984263bc
MD
1817 */
1818 SIGADDSET(p->p_siglist, sig);
08f2f1bb 1819 if (SIGISMEMBER(lp->lwp_sigmask, sig))
984263bc
MD
1820 continue;
1821
1822 /*
1823 * If the traced bit got turned off, go back up
1824 * to the top to rescan signals. This ensures
1825 * that p_sig* and ps_sigact are consistent.
1826 */
1827 if ((p->p_flag & P_TRACED) == 0)
1828 continue;
1829 }
1830
1831 prop = sigprop(sig);
1832
1833 /*
1834 * Decide whether the signal should be returned.
1835 * Return the signal's number, or fall through
1836 * to clear it from the pending mask.
1837 */
16094a36
MD
1838 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
1839 case (intptr_t)SIG_DFL:
984263bc
MD
1840 /*
1841 * Don't take default actions on system processes.
1842 */
1843 if (p->p_pid <= 1) {
1844#ifdef DIAGNOSTIC
1845 /*
1846 * Are you sure you want to ignore SIGSEGV
1847 * in init? XXX
1848 */
6ea70f76 1849 kprintf("Process (pid %lu) got signal %d\n",
984263bc
MD
1850 (u_long)p->p_pid, sig);
1851#endif
1852 break; /* == ignore */
1853 }
f758a39e
MD
1854
1855 /*
1856 * Handle the in-kernel checkpoint action
1857 */
1858 if (prop & SA_CKPT) {
7d20a8ff 1859 checkpoint_signal_handler(lp);
f758a39e
MD
1860 break;
1861 }
1862
984263bc
MD
1863 /*
1864 * If there is a pending stop signal to process
1865 * with default action, stop here,
1866 * then clear the signal. However,
1867 * if process is member of an orphaned
1868 * process group, ignore tty stop signals.
1869 */
1870 if (prop & SA_STOP) {
1871 if (p->p_flag & P_TRACED ||
1872 (p->p_pgrp->pg_jobc == 0 &&
1873 prop & SA_TTYSTOP))
1874 break; /* == ignore */
680b21e7 1875 p->p_xstat = sig;
f33e8653 1876 proc_stop(p);
e473f776 1877 tstop();
984263bc
MD
1878 break;
1879 } else if (prop & SA_IGNORE) {
1880 /*
1881 * Except for SIGCONT, shouldn't get here.
1882 * Default action is to ignore; drop it.
1883 */
1884 break; /* == ignore */
8ebcad3f 1885 } else {
5686ec5a 1886 lwkt_reltoken(&p->p_token);
984263bc 1887 return (sig);
8ebcad3f
MD
1888 }
1889
984263bc
MD
1890 /*NOTREACHED*/
1891
16094a36 1892 case (intptr_t)SIG_IGN:
984263bc
MD
1893 /*
1894 * Masking above should prevent us ever trying
1895 * to take action on an ignored signal other
1896 * than SIGCONT, unless process is traced.
1897 */
1898 if ((prop & SA_CONT) == 0 &&
1899 (p->p_flag & P_TRACED) == 0)
6ea70f76 1900 kprintf("issignal\n");
984263bc
MD
1901 break; /* == ignore */
1902
1903 default:
1904 /*
1905 * This signal has an action, let
1906 * postsig() process it.
1907 */
5686ec5a 1908 lwkt_reltoken(&p->p_token);
984263bc
MD
1909 return (sig);
1910 }
aa6c3de6 1911 lwp_delsig(lp, sig); /* take the signal! */
984263bc
MD
1912 }
1913 /* NOTREACHED */
1914}
1915
984263bc
MD
1916/*
1917 * Take the action for the specified signal
1918 * from the current set of pending signals.
025d695a
MD
1919 *
1920 * Caller must hold p->p_token
984263bc
MD
1921 */
1922void
8ebcad3f 1923postsig(int sig)
984263bc 1924{
08f2f1bb
SS
1925 struct lwp *lp = curthread->td_lwp;
1926 struct proc *p = lp->lwp_proc;
984263bc
MD
1927 struct sigacts *ps = p->p_sigacts;
1928 sig_t action;
1929 sigset_t returnmask;
1930 int code;
1931
1932 KASSERT(sig != 0, ("postsig"));
1933
6ac7d3ce
SG
1934 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
1935
7c1212ec
MD
1936 /*
1937 * If we are a virtual kernel running an emulated user process
1938 * context, switch back to the virtual kernel context before
1939 * trying to post the signal.
1940 */
39005e16 1941 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
287ebb09 1942 struct trapframe *tf = lp->lwp_md.md_regs;
7c1212ec 1943 tf->tf_trapno = 0;
287ebb09 1944 vkernel_trap(lp, tf);
7c1212ec
MD
1945 }
1946
aa6c3de6 1947 lwp_delsig(lp, sig);
984263bc
MD
1948 action = ps->ps_sigact[_SIG_IDX(sig)];
1949#ifdef KTRACE
08f2f1bb 1950 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
9fb04d14 1951 ktrpsig(lp, sig, action, lp->lwp_flag & LWP_OLDMASK ?
08f2f1bb 1952 &lp->lwp_oldsigmask : &lp->lwp_sigmask, 0);
984263bc
MD
1953#endif
1954 STOPEVENT(p, S_SIG, sig);
1955
1956 if (action == SIG_DFL) {
1957 /*
1958 * Default action, where the default is to kill
1959 * the process. (Other cases were ignored above.)
1960 */
b276424c 1961 sigexit(lp, sig);
984263bc
MD
1962 /* NOTREACHED */
1963 } else {
1964 /*
1965 * If we get here, the signal must be caught.
1966 */
08f2f1bb 1967 KASSERT(action != SIG_IGN && !SIGISMEMBER(lp->lwp_sigmask, sig),
984263bc 1968 ("postsig action"));
7c1212ec
MD
1969
1970 crit_enter();
1971
1972 /*
1973 * Reset the signal handler if asked to
1974 */
1975 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
1976 /*
1977 * See kern_sigaction() for origin of this code.
1978 */
1979 SIGDELSET(p->p_sigcatch, sig);
1980 if (sig != SIGCONT &&
1981 sigprop(sig) & SA_IGNORE)
1982 SIGADDSET(p->p_sigignore, sig);
1983 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1984 }
1985
1986 /*
1987 * Handle the mailbox case. Copyout to the appropriate
1988 * location but do not generate a signal frame. The system
1989 * call simply returns EINTR and the user is responsible for
1990 * polling the mailbox.
1991 */
1992 if (SIGISMEMBER(ps->ps_sigmailbox, sig)) {
1993 int sig_copy = sig;
1994 copyout(&sig_copy, (void *)action, sizeof(int));
1995 curproc->p_flag |= P_MAILBOX;
1996 crit_exit();
1997 goto done;
1998 }
1999
984263bc 2000 /*
7c1212ec
MD
2001 * Set the signal mask and calculate the mask to restore
2002 * when the signal function returns.
984263bc
MD
2003 *
2004 * Special case: user has done a sigsuspend. Here the
2005 * current mask is not of interest, but rather the
2006 * mask from before the sigsuspend is what we want
2007 * restored after the signal processing is completed.
2008 */
08f2f1bb
SS
2009 if (lp->lwp_flag & LWP_OLDMASK) {
2010 returnmask = lp->lwp_oldsigmask;
2011 lp->lwp_flag &= ~LWP_OLDMASK;
8ebcad3f 2012 } else {
08f2f1bb 2013 returnmask = lp->lwp_sigmask;
8ebcad3f 2014 }
08f2f1bb
SS
2015
2016 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
984263bc 2017 if (!SIGISMEMBER(ps->ps_signodefer, sig))
08f2f1bb 2018 SIGADDSET(lp->lwp_sigmask, sig);
984263bc 2019
e43a034f 2020 crit_exit();
08f2f1bb 2021 lp->lwp_ru.ru_nsignals++;
7d20a8ff 2022 if (lp->lwp_sig != sig) {
984263bc
MD
2023 code = 0;
2024 } else {
7d20a8ff
SS
2025 code = lp->lwp_code;
2026 lp->lwp_code = 0;
2027 lp->lwp_sig = 0;
984263bc
MD
2028 }
2029 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
2030 }
7c1212ec
MD
2031done:
2032 ;
984263bc
MD
2033}
2034
2035/*
2036 * Kill the current process for stated reason.
2037 */
2038void
8ebcad3f 2039killproc(struct proc *p, char *why)
984263bc 2040{
7c1212ec
MD
2041 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n",
2042 p->p_pid, p->p_comm,
41c20dac 2043 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
84204577 2044 ksignal(p, SIGKILL);
984263bc
MD
2045}
2046
2047/*
2048 * Force the current process to exit with the specified signal, dumping core
2049 * if appropriate. We bypass the normal tests for masked and caught signals,
2050 * allowing unrecoverable failures to terminate the process without changing
2051 * signal state. Mark the accounting record with the signal termination.
2052 * If dumping core, save the signal number for the debugger. Calls exit and
2053 * does not return.
2883d2d8
MD
2054 *
2055 * This routine does not return.
984263bc
MD
2056 */
2057void
b276424c 2058sigexit(struct lwp *lp, int sig)
984263bc 2059{
b276424c 2060 struct proc *p = lp->lwp_proc;
7d20a8ff 2061
b5c4d81f 2062 lwkt_gettoken(&p->p_token);
984263bc
MD
2063 p->p_acflag |= AXSIG;
2064 if (sigprop(sig) & SA_CORE) {
7d20a8ff 2065 lp->lwp_sig = sig;
984263bc
MD
2066 /*
2067 * Log signals which would cause core dumps
2068 * (Log as LOG_INFO to appease those who don't want
2069 * these messages.)
2070 * XXX : Todo, as well as euid, write out ruid too
2071 */
7d20a8ff 2072 if (coredump(lp, sig) == 0)
984263bc
MD
2073 sig |= WCOREFLAG;
2074 if (kern_logsigexit)
2075 log(LOG_INFO,
2076 "pid %d (%s), uid %d: exited on signal %d%s\n",
2077 p->p_pid, p->p_comm,
41c20dac 2078 p->p_ucred ? p->p_ucred->cr_uid : -1,
984263bc
MD
2079 sig &~ WCOREFLAG,
2080 sig & WCOREFLAG ? " (core dumped)" : "");
2081 }
b5c4d81f 2082 lwkt_reltoken(&p->p_token);
41c20dac 2083 exit1(W_EXITCODE(0, sig));
984263bc
MD
2084 /* NOTREACHED */
2085}
2086
2087static char corefilename[MAXPATHLEN+1] = {"%N.core"};
2088SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
2089 sizeof(corefilename), "process corefile name format string");
2090
2091/*
2092 * expand_name(name, uid, pid)
2093 * Expand the name described in corefilename, using name, uid, and pid.
6ea70f76 2094 * corefilename is a kprintf-like string, with three format specifiers:
984263bc
MD
2095 * %N name of process ("name")
2096 * %P process id (pid)
2097 * %U user id (uid)
2098 * For example, "%N.core" is the default; they can be disabled completely
2099 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
2100 * This is controlled by the sysctl variable kern.corefile (see above).
2101 */
2102
2103static char *
8ebcad3f
MD
2104expand_name(const char *name, uid_t uid, pid_t pid)
2105{
984263bc
MD
2106 char *temp;
2107 char buf[11]; /* Buffer for pid/uid -- max 4B */
2108 int i, n;
2109 char *format = corefilename;
2110 size_t namelen;
2111
efda3bd0 2112 temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
984263bc
MD
2113 if (temp == NULL)
2114 return NULL;
2115 namelen = strlen(name);
2116 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
2117 int l;
2118 switch (format[i]) {
2119 case '%': /* Format character */
2120 i++;
2121 switch (format[i]) {
2122 case '%':
2123 temp[n++] = '%';
2124 break;
2125 case 'N': /* process name */
2126 if ((n + namelen) > MAXPATHLEN) {
2127 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2128 pid, name, uid, temp, name);
efda3bd0 2129 kfree(temp, M_TEMP);
984263bc
MD
2130 return NULL;
2131 }
2132 memcpy(temp+n, name, namelen);
2133 n += namelen;
2134 break;
2135 case 'P': /* process id */
f8c7a42d 2136 l = ksprintf(buf, "%u", pid);
984263bc
MD
2137 if ((n + l) > MAXPATHLEN) {
2138 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2139 pid, name, uid, temp, name);
efda3bd0 2140 kfree(temp, M_TEMP);
984263bc
MD
2141 return NULL;
2142 }
2143 memcpy(temp+n, buf, l);
2144 n += l;
2145 break;
2146 case 'U': /* user id */
f8c7a42d 2147 l = ksprintf(buf, "%u", uid);
984263bc
MD
2148 if ((n + l) > MAXPATHLEN) {
2149 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2150 pid, name, uid, temp, name);
efda3bd0 2151 kfree(temp, M_TEMP);
984263bc
MD
2152 return NULL;
2153 }
2154 memcpy(temp+n, buf, l);
2155 n += l;
2156 break;
2157 default:
2158 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
2159 }
2160 break;
2161 default:
2162 temp[n++] = format[i];
2163 }
2164 }
2165 temp[n] = '\0';
2166 return temp;
2167}
2168
2169/*
2170 * Dump a process' core. The main routine does some
2171 * policy checking, and creates the name of the coredump;
2172 * then it passes on a vnode and a size limit to the process-specific
2173 * coredump routine if there is one; if there _is not_ one, it returns
2174 * ENOSYS; otherwise it returns the error from the process-specific routine.
7d20a8ff
SS
2175 *
2176 * The parameter `lp' is the lwp which triggered the coredump.
984263bc
MD
2177 */
2178
2179static int
7d20a8ff 2180coredump(struct lwp *lp, int sig)
984263bc 2181{
7d20a8ff 2182 struct proc *p = lp->lwp_proc;
dadab5e9
MD
2183 struct vnode *vp;
2184 struct ucred *cred = p->p_ucred;
984263bc 2185 struct flock lf;
fad57d0e 2186 struct nlookupdata nd;
984263bc
MD
2187 struct vattr vattr;
2188 int error, error1;
2189 char *name; /* name of corefile */
2190 off_t limit;
2191
2192 STOPEVENT(p, S_CORE, 0);
2193
2194 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0)
2195 return (EFAULT);
2196
2197 /*
2198 * Note that the bulk of limit checking is done after
2199 * the corefile is created. The exception is if the limit
2200 * for corefiles is 0, in which case we don't bother
2201 * creating the corefile at all. This layout means that
2202 * a corefile is truncated instead of not being created,
2203 * if it is larger than the limit.
2204 */
2205 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
2206 if (limit == 0)
50fd5388 2207 return EFBIG;
984263bc
MD
2208
2209 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
2210 if (name == NULL)
2211 return (EINVAL);
fad57d0e
MD
2212 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
2213 if (error == 0)
2214 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
efda3bd0 2215 kfree(name, M_TEMP);
fad57d0e
MD
2216 if (error) {
2217 nlookup_done(&nd);
984263bc 2218 return (error);
fad57d0e
MD
2219 }
2220 vp = nd.nl_open_vp;
2221 nd.nl_open_vp = NULL;
2222 nlookup_done(&nd);
984263bc 2223
a11aaa81 2224 vn_unlock(vp);
984263bc
MD
2225 lf.l_whence = SEEK_SET;
2226 lf.l_start = 0;
2227 lf.l_len = 0;
2228 lf.l_type = F_WRLCK;
71c18fe3 2229 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0);
984263bc
MD
2230 if (error)
2231 goto out2;
2232
2233 /* Don't dump to non-regular files or files with links. */
2234 if (vp->v_type != VREG ||
87de5057 2235 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) {
984263bc
MD
2236 error = EFAULT;
2237 goto out1;
2238 }
2239
9d2a4e5d
MD
2240 /* Don't dump to files current user does not own */
2241 if (vattr.va_uid != p->p_ucred->cr_uid) {
2242 error = EFAULT;
2243 goto out1;
2244 }
2245
984263bc 2246 VATTR_NULL(&vattr);
ca466bae 2247 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
984263bc 2248 vattr.va_size = 0;
87de5057 2249 VOP_SETATTR(vp, &vattr, cred);
984263bc 2250 p->p_acflag |= ACORE;
a11aaa81 2251 vn_unlock(vp);
984263bc
MD
2252
2253 error = p->p_sysent->sv_coredump ?
7d20a8ff 2254 p->p_sysent->sv_coredump(lp, sig, vp, limit) : ENOSYS;
984263bc
MD
2255
2256out1:
2257 lf.l_type = F_UNLCK;
71c18fe3 2258 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0);
984263bc 2259out2:
87de5057 2260 error1 = vn_close(vp, FWRITE);
984263bc
MD
2261 if (error == 0)
2262 error = error1;
2263 return (error);
2264}
2265
2266/*
2267 * Nonexistent system call-- signal process (may want to handle it).
2268 * Flag error in case process won't see signal immediately (blocked or ignored).
3919ced0
MD
2269 *
2270 * MPALMOSTSAFE
984263bc 2271 */
984263bc
MD
2272/* ARGSUSED */
2273int
753fd850 2274sys_nosys(struct nosys_args *args)
984263bc 2275{
7278a846 2276 lwpsignal(curproc, curthread->td_lwp, SIGSYS);
984263bc
MD
2277 return (EINVAL);
2278}
2279
2280/*
2281 * Send a SIGIO or SIGURG signal to a process or process group using
2282 * stored credentials rather than those of the current process.
2283 */
2284void
dadab5e9 2285pgsigio(struct sigio *sigio, int sig, int checkctty)
984263bc
MD
2286{
2287 if (sigio == NULL)
2288 return;
2289
2290 if (sigio->sio_pgid > 0) {
2291 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
2292 sigio->sio_proc))
84204577 2293 ksignal(sigio->sio_proc, sig);
984263bc
MD
2294 } else if (sigio->sio_pgid < 0) {
2295 struct proc *p;
58c2553a 2296 struct pgrp *pg = sigio->sio_pgrp;
984263bc 2297
58c2553a
MD
2298 /*
2299 * Must interlock all signals against fork
2300 */
2301 pgref(pg);
2302 lockmgr(&pg->pg_lock, LK_EXCLUSIVE);
2303 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
984263bc
MD
2304 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
2305 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
84204577 2306 ksignal(p, sig);
167e6ecb 2307 }
58c2553a
MD
2308 lockmgr(&pg->pg_lock, LK_RELEASE);
2309 pgrel(pg);
984263bc
MD
2310 }
2311}
2312
2313static int
2314filt_sigattach(struct knote *kn)
2315{
2316 struct proc *p = curproc;
2317
2318 kn->kn_ptr.p_proc = p;
2319 kn->kn_flags |= EV_CLEAR; /* automatically set */
2320
2321 /* XXX lock the proc here while adding to the list? */
5b22f1a7 2322 knote_insert(&p->p_klist, kn);
984263bc
MD
2323
2324 return (0);
2325}
2326
2327static void
2328filt_sigdetach(struct knote *kn)
2329{
2330 struct proc *p = kn->kn_ptr.p_proc;
2331
5b22f1a7 2332 knote_remove(&p->p_klist, kn);
984263bc
MD
2333}
2334
2335/*
2336 * signal knotes are shared with proc knotes, so we apply a mask to
2337 * the hint in order to differentiate them from process hints. This
2338 * could be avoided by using a signal-specific knote list, but probably
2339 * isn't worth the trouble.
2340 */
2341static int
2342filt_signal(struct knote *kn, long hint)
2343{
984263bc
MD
2344 if (hint & NOTE_SIGNAL) {
2345 hint &= ~NOTE_SIGNAL;
2346
2347 if (kn->kn_id == hint)
2348 kn->kn_data++;
2349 }
2350 return (kn->kn_data != 0);
2351}