Rename printf -> kprintf in sys/ and add some defines where necessary
[dragonfly.git] / sys / kern / kern_sig.c
CommitLineData
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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 $
6ea70f76 40 * $DragonFly: src/sys/kern/kern_sig.c,v 1.58 2006/12/23 00:35:04 swildner Exp $
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41 */
42
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43#include "opt_ktrace.h"
44
45#include <sys/param.h>
dadab5e9 46#include <sys/systm.h>
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47#include <sys/kernel.h>
48#include <sys/sysproto.h>
49#include <sys/signalvar.h>
50#include <sys/resourcevar.h>
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51#include <sys/vnode.h>
52#include <sys/event.h>
53#include <sys/proc.h>
fad57d0e 54#include <sys/nlookup.h>
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55#include <sys/pioctl.h>
56#include <sys/systm.h>
57#include <sys/acct.h>
58#include <sys/fcntl.h>
167e6ecb 59#include <sys/lock.h>
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60#include <sys/wait.h>
61#include <sys/ktrace.h>
62#include <sys/syslog.h>
63#include <sys/stat.h>
64#include <sys/sysent.h>
65#include <sys/sysctl.h>
66#include <sys/malloc.h>
a7231bde 67#include <sys/interrupt.h>
984263bc 68#include <sys/unistd.h>
65957d54 69#include <sys/kern_syscall.h>
e43a034f 70#include <sys/thread2.h>
984263bc 71
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72#include <machine/cpu.h>
73#include <machine/smp.h>
74
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75static int coredump(struct proc *);
76static char *expand_name(const char *, uid_t, pid_t);
77static int killpg(int sig, int pgid, int all);
78static int sig_ffs(sigset_t *set);
79static int sigprop(int sig);
cb973d15 80#ifdef SMP
8ebcad3f 81static void signotify_remote(void *arg);
cb973d15 82#endif
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83static int kern_sigtimedwait(sigset_t set, siginfo_t *info,
84 struct timespec *timeout);
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85
86static int filt_sigattach(struct knote *kn);
87static void filt_sigdetach(struct knote *kn);
88static int filt_signal(struct knote *kn, long hint);
89
90struct filterops sig_filtops =
91 { 0, filt_sigattach, filt_sigdetach, filt_signal };
92
93static int kern_logsigexit = 1;
94SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
95 &kern_logsigexit, 0,
96 "Log processes quitting on abnormal signals to syslog(3)");
97
98/*
99 * Can process p, with pcred pc, send the signal sig to process q?
100 */
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101#define CANSIGNAL(q, sig) \
102 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \
103 ((sig) == SIGCONT && (q)->p_session == curproc->p_session))
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104
105/*
106 * Policy -- Can real uid ruid with ucred uc send a signal to process q?
107 */
108#define CANSIGIO(ruid, uc, q) \
109 ((uc)->cr_uid == 0 || \
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110 (ruid) == (q)->p_ucred->cr_ruid || \
111 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \
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112 (ruid) == (q)->p_ucred->cr_uid || \
113 (uc)->cr_uid == (q)->p_ucred->cr_uid)
114
115int sugid_coredump;
116SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
8ebcad3f 117 &sugid_coredump, 0, "Enable coredumping set user/group ID processes");
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118
119static int do_coredump = 1;
120SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
121 &do_coredump, 0, "Enable/Disable coredumps");
122
123/*
124 * Signal properties and actions.
125 * The array below categorizes the signals and their default actions
126 * according to the following properties:
127 */
128#define SA_KILL 0x01 /* terminates process by default */
129#define SA_CORE 0x02 /* ditto and coredumps */
130#define SA_STOP 0x04 /* suspend process */
131#define SA_TTYSTOP 0x08 /* ditto, from tty */
132#define SA_IGNORE 0x10 /* ignore by default */
133#define SA_CONT 0x20 /* continue if suspended */
134#define SA_CANTMASK 0x40 /* non-maskable, catchable */
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135#define SA_CKPT 0x80 /* checkpoint process */
136
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137
138static int sigproptbl[NSIG] = {
139 SA_KILL, /* SIGHUP */
140 SA_KILL, /* SIGINT */
141 SA_KILL|SA_CORE, /* SIGQUIT */
142 SA_KILL|SA_CORE, /* SIGILL */
143 SA_KILL|SA_CORE, /* SIGTRAP */
144 SA_KILL|SA_CORE, /* SIGABRT */
145 SA_KILL|SA_CORE, /* SIGEMT */
146 SA_KILL|SA_CORE, /* SIGFPE */
147 SA_KILL, /* SIGKILL */
148 SA_KILL|SA_CORE, /* SIGBUS */
149 SA_KILL|SA_CORE, /* SIGSEGV */
150 SA_KILL|SA_CORE, /* SIGSYS */
151 SA_KILL, /* SIGPIPE */
152 SA_KILL, /* SIGALRM */
153 SA_KILL, /* SIGTERM */
154 SA_IGNORE, /* SIGURG */
155 SA_STOP, /* SIGSTOP */
156 SA_STOP|SA_TTYSTOP, /* SIGTSTP */
157 SA_IGNORE|SA_CONT, /* SIGCONT */
158 SA_IGNORE, /* SIGCHLD */
159 SA_STOP|SA_TTYSTOP, /* SIGTTIN */
160 SA_STOP|SA_TTYSTOP, /* SIGTTOU */
161 SA_IGNORE, /* SIGIO */
162 SA_KILL, /* SIGXCPU */
163 SA_KILL, /* SIGXFSZ */
164 SA_KILL, /* SIGVTALRM */
165 SA_KILL, /* SIGPROF */
166 SA_IGNORE, /* SIGWINCH */
167 SA_IGNORE, /* SIGINFO */
168 SA_KILL, /* SIGUSR1 */
169 SA_KILL, /* SIGUSR2 */
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170 SA_IGNORE, /* SIGTHR */
171 SA_CKPT, /* SIGCKPT */
172 SA_KILL|SA_CKPT, /* SIGCKPTEXIT */
173 SA_IGNORE,
174 SA_IGNORE,
175 SA_IGNORE,
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
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204};
205
206static __inline int
207sigprop(int sig)
208{
209
210 if (sig > 0 && sig < NSIG)
211 return (sigproptbl[_SIG_IDX(sig)]);
212 return (0);
213}
214
215static __inline int
216sig_ffs(sigset_t *set)
217{
218 int i;
219
220 for (i = 0; i < _SIG_WORDS; i++)
221 if (set->__bits[i])
222 return (ffs(set->__bits[i]) + (i * 32));
223 return (0);
224}
225
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226int
227kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact)
984263bc 228{
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DRJ
229 struct thread *td = curthread;
230 struct proc *p = td->td_proc;
41c20dac 231 struct sigacts *ps = p->p_sigacts;
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232
233 if (sig <= 0 || sig > _SIG_MAXSIG)
234 return (EINVAL);
235
236 if (oact) {
237 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
238 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
239 oact->sa_flags = 0;
240 if (SIGISMEMBER(ps->ps_sigonstack, sig))
241 oact->sa_flags |= SA_ONSTACK;
242 if (!SIGISMEMBER(ps->ps_sigintr, sig))
243 oact->sa_flags |= SA_RESTART;
244 if (SIGISMEMBER(ps->ps_sigreset, sig))
245 oact->sa_flags |= SA_RESETHAND;
246 if (SIGISMEMBER(ps->ps_signodefer, sig))
247 oact->sa_flags |= SA_NODEFER;
248 if (SIGISMEMBER(ps->ps_siginfo, sig))
249 oact->sa_flags |= SA_SIGINFO;
250 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDSTOP)
251 oact->sa_flags |= SA_NOCLDSTOP;
252 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDWAIT)
253 oact->sa_flags |= SA_NOCLDWAIT;
254 }
255 if (act) {
256 if ((sig == SIGKILL || sig == SIGSTOP) &&
257 act->sa_handler != SIG_DFL)
258 return (EINVAL);
259
260 /*
261 * Change setting atomically.
262 */
e43a034f 263 crit_enter();
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264
265 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
266 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
267 if (act->sa_flags & SA_SIGINFO) {
268 ps->ps_sigact[_SIG_IDX(sig)] =
269 (__sighandler_t *)act->sa_sigaction;
270 SIGADDSET(ps->ps_siginfo, sig);
271 } else {
272 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
273 SIGDELSET(ps->ps_siginfo, sig);
274 }
275 if (!(act->sa_flags & SA_RESTART))
276 SIGADDSET(ps->ps_sigintr, sig);
277 else
278 SIGDELSET(ps->ps_sigintr, sig);
279 if (act->sa_flags & SA_ONSTACK)
280 SIGADDSET(ps->ps_sigonstack, sig);
281 else
282 SIGDELSET(ps->ps_sigonstack, sig);
283 if (act->sa_flags & SA_RESETHAND)
284 SIGADDSET(ps->ps_sigreset, sig);
285 else
286 SIGDELSET(ps->ps_sigreset, sig);
287 if (act->sa_flags & SA_NODEFER)
288 SIGADDSET(ps->ps_signodefer, sig);
289 else
290 SIGDELSET(ps->ps_signodefer, sig);
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291 if (sig == SIGCHLD) {
292 if (act->sa_flags & SA_NOCLDSTOP)
293 p->p_procsig->ps_flag |= PS_NOCLDSTOP;
294 else
295 p->p_procsig->ps_flag &= ~PS_NOCLDSTOP;
296 if (act->sa_flags & SA_NOCLDWAIT) {
297 /*
298 * Paranoia: since SA_NOCLDWAIT is implemented
299 * by reparenting the dying child to PID 1 (and
300 * trust it to reap the zombie), PID 1 itself
301 * is forbidden to set SA_NOCLDWAIT.
302 */
303 if (p->p_pid == 1)
304 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT;
305 else
306 p->p_procsig->ps_flag |= PS_NOCLDWAIT;
8ebcad3f 307 } else {
984263bc 308 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT;
8ebcad3f 309 }
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310 }
311 /*
312 * Set bit in p_sigignore for signals that are set to SIG_IGN,
313 * and for signals set to SIG_DFL where the default is to
314 * ignore. However, don't put SIGCONT in p_sigignore, as we
315 * have to restart the process.
316 */
317 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
318 (sigprop(sig) & SA_IGNORE &&
319 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
320 /* never to be seen again */
321 SIGDELSET(p->p_siglist, sig);
322 if (sig != SIGCONT)
84204577 323 /* easier in ksignal */
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324 SIGADDSET(p->p_sigignore, sig);
325 SIGDELSET(p->p_sigcatch, sig);
326 } else {
327 SIGDELSET(p->p_sigignore, sig);
328 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
329 SIGDELSET(p->p_sigcatch, sig);
330 else
331 SIGADDSET(p->p_sigcatch, sig);
332 }
984263bc 333
e43a034f 334 crit_exit();
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335 }
336 return (0);
337}
338
984263bc 339int
753fd850 340sys_sigaction(struct sigaction_args *uap)
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341{
342 struct sigaction act, oact;
1fd87d54 343 struct sigaction *actp, *oactp;
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344 int error;
345
346 actp = (uap->act != NULL) ? &act : NULL;
347 oactp = (uap->oact != NULL) ? &oact : NULL;
348 if (actp) {
349 error = copyin(uap->act, actp, sizeof(act));
350 if (error)
351 return (error);
352 }
65957d54 353 error = kern_sigaction(uap->sig, actp, oactp);
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354 if (oactp && !error) {
355 error = copyout(oactp, uap->oact, sizeof(oact));
356 }
357 return (error);
358}
359
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360/*
361 * Initialize signal state for process 0;
362 * set to ignore signals that are ignored by default.
363 */
364void
8ebcad3f 365siginit(struct proc *p)
984263bc 366{
1fd87d54 367 int i;
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368
369 for (i = 1; i <= NSIG; i++)
370 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
371 SIGADDSET(p->p_sigignore, i);
372}
373
374/*
375 * Reset signals for an exec of the specified process.
376 */
377void
8ebcad3f 378execsigs(struct proc *p)
984263bc 379{
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380 struct sigacts *ps = p->p_sigacts;
381 int sig;
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382
383 /*
384 * Reset caught signals. Held signals remain held
385 * through p_sigmask (unless they were caught,
386 * and are now ignored by default).
387 */
388 while (SIGNOTEMPTY(p->p_sigcatch)) {
389 sig = sig_ffs(&p->p_sigcatch);
390 SIGDELSET(p->p_sigcatch, sig);
391 if (sigprop(sig) & SA_IGNORE) {
392 if (sig != SIGCONT)
393 SIGADDSET(p->p_sigignore, sig);
394 SIGDELSET(p->p_siglist, sig);
395 }
396 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
397 }
398 /*
399 * Reset stack state to the user stack.
400 * Clear set of signals caught on the signal stack.
401 */
402 p->p_sigstk.ss_flags = SS_DISABLE;
403 p->p_sigstk.ss_size = 0;
404 p->p_sigstk.ss_sp = 0;
405 p->p_flag &= ~P_ALTSTACK;
406 /*
407 * Reset no zombies if child dies flag as Solaris does.
408 */
409 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT;
410}
411
412/*
65957d54 413 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
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414 *
415 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
e43a034f 416 * p == curproc.
984263bc 417 */
65957d54
DRJ
418int
419kern_sigprocmask(int how, sigset_t *set, sigset_t *oset)
984263bc 420{
65957d54
DRJ
421 struct thread *td = curthread;
422 struct proc *p = td->td_proc;
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423 int error;
424
425 if (oset != NULL)
426 *oset = p->p_sigmask;
427
428 error = 0;
429 if (set != NULL) {
430 switch (how) {
431 case SIG_BLOCK:
432 SIG_CANTMASK(*set);
433 SIGSETOR(p->p_sigmask, *set);
434 break;
435 case SIG_UNBLOCK:
436 SIGSETNAND(p->p_sigmask, *set);
437 break;
438 case SIG_SETMASK:
439 SIG_CANTMASK(*set);
65957d54 440 p->p_sigmask = *set;
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441 break;
442 default:
443 error = EINVAL;
444 break;
445 }
446 }
447 return (error);
448}
449
450/*
451 * sigprocmask() - MP SAFE
452 */
984263bc 453int
753fd850 454sys_sigprocmask(struct sigprocmask_args *uap)
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455{
456 sigset_t set, oset;
457 sigset_t *setp, *osetp;
458 int error;
459
460 setp = (uap->set != NULL) ? &set : NULL;
461 osetp = (uap->oset != NULL) ? &oset : NULL;
462 if (setp) {
463 error = copyin(uap->set, setp, sizeof(set));
464 if (error)
465 return (error);
466 }
65957d54 467 error = kern_sigprocmask(uap->how, setp, osetp);
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468 if (osetp && !error) {
469 error = copyout(osetp, uap->oset, sizeof(oset));
470 }
471 return (error);
472}
473
984263bc 474int
65957d54 475kern_sigpending(struct __sigset *set)
984263bc 476{
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DRJ
477 struct thread *td = curthread;
478 struct proc *p = td->td_proc;
984263bc 479
65957d54 480 *set = p->p_siglist;
984263bc 481
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482 return (0);
483}
484
984263bc 485int
753fd850 486sys_sigpending(struct sigpending_args *uap)
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487{
488 sigset_t set;
65957d54 489 int error;
984263bc 490
65957d54 491 error = kern_sigpending(&set);
984263bc 492
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DRJ
493 if (error == 0)
494 error = copyout(&set, uap->set, sizeof(set));
495 return (error);
984263bc 496}
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497
498/*
499 * Suspend process until signal, providing mask to be set
65957d54 500 * in the meantime.
984263bc 501 */
984263bc 502int
65957d54 503kern_sigsuspend(struct __sigset *set)
984263bc 504{
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DRJ
505 struct thread *td = curthread;
506 struct proc *p = td->td_proc;
41c20dac 507 struct sigacts *ps = p->p_sigacts;
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508
509 /*
510 * When returning from sigsuspend, we want
511 * the old mask to be restored after the
512 * signal handler has finished. Thus, we
513 * save it here and mark the sigacts structure
514 * to indicate this.
515 */
516 p->p_oldsigmask = p->p_sigmask;
517 p->p_flag |= P_OLDMASK;
518
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519 SIG_CANTMASK(*set);
520 p->p_sigmask = *set;
521 while (tsleep(ps, PCATCH, "pause", 0) == 0)
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522 /* void */;
523 /* always return EINTR rather than ERESTART... */
524 return (EINTR);
525}
526
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527/*
528 * Note nonstandard calling convention: libc stub passes mask, not
529 * pointer, to save a copyin.
530 */
984263bc 531int
753fd850 532sys_sigsuspend(struct sigsuspend_args *uap)
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533{
534 sigset_t mask;
65957d54 535 int error;
984263bc 536
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537 error = copyin(uap->sigmask, &mask, sizeof(mask));
538 if (error)
539 return (error);
540
541 error = kern_sigsuspend(&mask);
542
543 return (error);
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544}
545
984263bc 546int
65957d54 547kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss)
984263bc 548{
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DRJ
549 struct thread *td = curthread;
550 struct proc *p = td->td_proc;
984263bc 551
65957d54
DRJ
552 if ((p->p_flag & P_ALTSTACK) == 0)
553 p->p_sigstk.ss_flags |= SS_DISABLE;
554
555 if (oss)
556 *oss = p->p_sigstk;
557
558 if (ss) {
559 if (ss->ss_flags & SS_DISABLE) {
560 if (p->p_sigstk.ss_flags & SS_ONSTACK)
561 return (EINVAL);
562 p->p_flag &= ~P_ALTSTACK;
563 p->p_sigstk.ss_flags = ss->ss_flags;
564 } else {
565 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
566 return (ENOMEM);
567 p->p_flag |= P_ALTSTACK;
568 p->p_sigstk = *ss;
569 }
984263bc 570 }
65957d54
DRJ
571
572 return (0);
984263bc 573}
984263bc 574
984263bc 575int
753fd850 576sys_sigaltstack(struct sigaltstack_args *uap)
984263bc 577{
65957d54 578 stack_t ss, oss;
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579 int error;
580
65957d54
DRJ
581 if (uap->ss) {
582 error = copyin(uap->ss, &ss, sizeof(ss));
583 if (error)
584 return (error);
984263bc 585 }
65957d54
DRJ
586
587 error = kern_sigaltstack(uap->ss ? &ss : NULL,
588 uap->oss ? &oss : NULL);
589
590 if (error == 0 && uap->oss)
591 error = copyout(&oss, uap->oss, sizeof(*uap->oss));
592 return (error);
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593}
594
595/*
596 * Common code for kill process group/broadcast kill.
597 * cp is calling process.
598 */
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599struct killpg_info {
600 int nfound;
601 int sig;
602};
603
604static int killpg_all_callback(struct proc *p, void *data);
605
65957d54
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606static int
607killpg(int sig, int pgid, int all)
984263bc 608{
8fa76237 609 struct killpg_info info;
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610 struct proc *cp = curproc;
611 struct proc *p;
984263bc 612 struct pgrp *pgrp;
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613
614 info.nfound = 0;
615 info.sig = sig;
984263bc 616
8ebcad3f 617 if (all) {
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618 /*
619 * broadcast
620 */
8fa76237 621 allproc_scan(killpg_all_callback, &info);
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622 } else {
623 if (pgid == 0) {
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624 /*
625 * zero pgid means send to my process group.
626 */
627 pgrp = cp->p_pgrp;
8ebcad3f 628 } else {
984263bc
MD
629 pgrp = pgfind(pgid);
630 if (pgrp == NULL)
631 return (ESRCH);
632 }
167e6ecb 633 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
984263bc 634 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
f026f3b0
MD
635 if (p->p_pid <= 1 ||
636 (p->p_flag & (P_SYSTEM | P_ZOMBIE)) ||
637 !CANSIGNAL(p, sig)) {
984263bc 638 continue;
f026f3b0 639 }
8fa76237 640 ++info.nfound;
984263bc 641 if (sig)
84204577 642 ksignal(p, sig);
984263bc 643 }
167e6ecb 644 lockmgr(&pgrp->pg_lock, LK_RELEASE);
984263bc 645 }
8fa76237
MD
646 return (info.nfound ? 0 : ESRCH);
647}
648
649static int
650killpg_all_callback(struct proc *p, void *data)
651{
652 struct killpg_info *info = data;
653
654 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) ||
655 p == curproc || !CANSIGNAL(p, info->sig)) {
656 return (0);
657 }
658 ++info->nfound;
659 if (info->sig)
84204577 660 ksignal(p, info->sig);
8fa76237 661 return(0);
984263bc
MD
662}
663
984263bc 664int
65957d54 665kern_kill(int sig, int pid)
984263bc 666{
65957d54
DRJ
667 struct thread *td = curthread;
668 struct proc *p = td->td_proc;
984263bc 669
65957d54 670 if ((u_int)sig > _SIG_MAXSIG)
984263bc 671 return (EINVAL);
65957d54 672 if (pid > 0) {
984263bc 673 /* kill single process */
65957d54 674 if ((p = pfind(pid)) == NULL)
984263bc 675 return (ESRCH);
65957d54 676 if (!CANSIGNAL(p, sig))
984263bc 677 return (EPERM);
65957d54 678 if (sig)
84204577 679 ksignal(p, sig);
984263bc
MD
680 return (0);
681 }
65957d54 682 switch (pid) {
984263bc 683 case -1: /* broadcast signal */
65957d54 684 return (killpg(sig, 0, 1));
984263bc 685 case 0: /* signal own process group */
65957d54 686 return (killpg(sig, 0, 0));
984263bc 687 default: /* negative explicit process group */
65957d54 688 return (killpg(sig, -pid, 0));
984263bc
MD
689 }
690 /* NOTREACHED */
691}
692
984263bc 693int
753fd850 694sys_kill(struct kill_args *uap)
984263bc 695{
65957d54
DRJ
696 int error;
697
698 error = kern_kill(uap->signum, uap->pid);
699
700 return (error);
984263bc 701}
984263bc
MD
702
703/*
704 * Send a signal to a process group.
705 */
706void
41c20dac 707gsignal(int pgid, int sig)
984263bc
MD
708{
709 struct pgrp *pgrp;
710
711 if (pgid && (pgrp = pgfind(pgid)))
712 pgsignal(pgrp, sig, 0);
713}
714
715/*
716 * Send a signal to a process group. If checktty is 1,
717 * limit to members which have a controlling terminal.
167e6ecb
MD
718 *
719 * pg_lock interlocks against a fork that might be in progress, to
720 * ensure that the new child process picks up the signal.
984263bc
MD
721 */
722void
8ebcad3f 723pgsignal(struct pgrp *pgrp, int sig, int checkctty)
984263bc 724{
1fd87d54 725 struct proc *p;
984263bc 726
167e6ecb
MD
727 if (pgrp) {
728 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
729 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
984263bc 730 if (checkctty == 0 || p->p_flag & P_CONTROLT)
84204577 731 ksignal(p, sig);
167e6ecb
MD
732 }
733 lockmgr(&pgrp->pg_lock, LK_RELEASE);
734 }
984263bc
MD
735}
736
737/*
738 * Send a signal caused by a trap to the current process.
739 * If it will be caught immediately, deliver it with correct code.
740 * Otherwise, post it normally.
741 */
742void
8ebcad3f 743trapsignal(struct proc *p, int sig, u_long code)
984263bc 744{
dadab5e9 745 struct sigacts *ps = p->p_sigacts;
984263bc
MD
746
747 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
748 !SIGISMEMBER(p->p_sigmask, sig)) {
749 p->p_stats->p_ru.ru_nsignals++;
750#ifdef KTRACE
dadab5e9 751 if (KTRPOINT(p->p_thread, KTR_PSIG))
a9b80e23 752 ktrpsig(p, sig, ps->ps_sigact[_SIG_IDX(sig)],
984263bc
MD
753 &p->p_sigmask, code);
754#endif
755 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
756 &p->p_sigmask, code);
757 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
758 if (!SIGISMEMBER(ps->ps_signodefer, sig))
759 SIGADDSET(p->p_sigmask, sig);
760 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
761 /*
65957d54 762 * See kern_sigaction() for origin of this code.
984263bc
MD
763 */
764 SIGDELSET(p->p_sigcatch, sig);
765 if (sig != SIGCONT &&
766 sigprop(sig) & SA_IGNORE)
767 SIGADDSET(p->p_sigignore, sig);
768 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
769 }
770 } else {
771 p->p_code = code; /* XXX for core dump/debugger */
772 p->p_sig = sig; /* XXX to verify code */
84204577 773 ksignal(p, sig);
984263bc
MD
774 }
775}
776
777/*
778 * Send the signal to the process. If the signal has an action, the action
779 * is usually performed by the target process rather than the caller; we add
780 * the signal to the set of pending signals for the process.
781 *
782 * Exceptions:
783 * o When a stop signal is sent to a sleeping process that takes the
784 * default action, the process is stopped without awakening it.
785 * o SIGCONT restarts stopped processes (or puts them back to sleep)
786 * regardless of the signal action (eg, blocked or ignored).
787 *
788 * Other ignored signals are discarded immediately.
789 */
790void
84204577 791ksignal(struct proc *p, int sig)
984263bc 792{
553ea3c8 793 struct lwp *lp = &p->p_lwp;
e43a034f 794 int prop;
cb973d15 795 sig_t action;
984263bc
MD
796
797 if (sig > _SIG_MAXSIG || sig <= 0) {
6ea70f76 798 kprintf("ksignal: signal %d\n", sig);
84204577 799 panic("ksignal signal number");
984263bc
MD
800 }
801
e43a034f 802 crit_enter();
984263bc 803 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
e43a034f 804 crit_exit();
984263bc
MD
805
806 prop = sigprop(sig);
807
808 /*
809 * If proc is traced, always give parent a chance;
810 * if signal event is tracked by procfs, give *that*
811 * a chance, as well.
812 */
8ebcad3f 813 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) {
984263bc 814 action = SIG_DFL;
8ebcad3f 815 } else {
984263bc
MD
816 /*
817 * If the signal is being ignored,
818 * then we forget about it immediately.
819 * (Note: we don't set SIGCONT in p_sigignore,
820 * and if it is set to SIG_IGN,
821 * action will be SIG_DFL here.)
822 */
823 if (SIGISMEMBER(p->p_sigignore, sig) || (p->p_flag & P_WEXIT))
824 return;
825 if (SIGISMEMBER(p->p_sigmask, sig))
826 action = SIG_HOLD;
827 else if (SIGISMEMBER(p->p_sigcatch, sig))
828 action = SIG_CATCH;
829 else
830 action = SIG_DFL;
831 }
832
833 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
8ebcad3f 834 (p->p_flag & P_TRACED) == 0) {
984263bc 835 p->p_nice = NZERO;
8ebcad3f 836 }
984263bc 837
344ad853
MD
838 /*
839 * If continuing, clear any pending STOP signals.
840 */
984263bc
MD
841 if (prop & SA_CONT)
842 SIG_STOPSIGMASK(p->p_siglist);
9d63d5c0 843
984263bc
MD
844 if (prop & SA_STOP) {
845 /*
846 * If sending a tty stop signal to a member of an orphaned
847 * process group, discard the signal here if the action
848 * is default; don't stop the process below if sleeping,
849 * and don't clear any pending SIGCONT.
850 */
851 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
8ebcad3f 852 action == SIG_DFL) {
984263bc 853 return;
8ebcad3f 854 }
984263bc
MD
855 SIG_CONTSIGMASK(p->p_siglist);
856 }
857 SIGADDSET(p->p_siglist, sig);
858
859 /*
860 * Defer further processing for signals which are held,
861 * except that stopped processes must be continued by SIGCONT.
862 */
344ad853
MD
863 if (action == SIG_HOLD) {
864 if ((prop & SA_CONT) == 0 || (p->p_flag & P_STOPPED) == 0)
865 return;
866 }
e43a034f
MD
867
868 crit_enter();
869
344ad853
MD
870 /*
871 * Process is in tsleep and not stopped
872 */
873 if (p->p_stat == SSLEEP && (p->p_flag & P_STOPPED) == 0) {
984263bc 874 /*
344ad853 875 * If the process is sleeping uninterruptibly
984263bc
MD
876 * we can't interrupt the sleep... the signal will
877 * be noticed when the process returns through
878 * trap() or syscall().
879 */
880 if ((p->p_flag & P_SINTR) == 0)
881 goto out;
344ad853 882
984263bc 883 /*
344ad853 884 * If the process is sleeping and traced, make it runnable
984263bc
MD
885 * so it can discover the signal in issignal() and stop
886 * for the parent.
344ad853
MD
887 *
888 * If the process is stopped and traced, no further action
889 * is necessary.
984263bc
MD
890 */
891 if (p->p_flag & P_TRACED)
892 goto run;
344ad853 893
984263bc 894 /*
344ad853
MD
895 * If the process is sleeping and SA_CONT, and the signal
896 * mode is SIG_DFL, then make the process runnable.
897 *
898 * However, do *NOT* set P_BREAKTSLEEP. We do not want
899 * a SIGCONT to terminate an interruptable tsleep early
900 * and generate a spurious EINTR.
984263bc
MD
901 */
902 if ((prop & SA_CONT) && action == SIG_DFL) {
903 SIGDELSET(p->p_siglist, sig);
344ad853 904 goto run_no_break;
984263bc 905 }
344ad853 906
984263bc 907 /*
344ad853
MD
908 * If the process is sleeping and receives a STOP signal,
909 * process immediately if possible. All other (caught or
910 * default) signals cause the process to run.
984263bc
MD
911 */
912 if (prop & SA_STOP) {
913 if (action != SIG_DFL)
26a0694b 914 goto run;
344ad853 915
984263bc 916 /*
344ad853
MD
917 * If a child holding parent blocked, stopping
918 * could cause deadlock. Take no action at this
919 * time.
984263bc
MD
920 */
921 if (p->p_flag & P_PPWAIT)
922 goto out;
344ad853
MD
923
924 /*
925 * Do not actually try to manipulate the process
926 * while it is sleeping, simply set P_STOPPED to
927 * indicate that it should stop as soon as it safely
928 * can.
929 */
984263bc 930 SIGDELSET(p->p_siglist, sig);
344ad853
MD
931 p->p_flag |= P_STOPPED;
932 p->p_flag &= ~P_WAITED;
984263bc 933 p->p_xstat = sig;
25c776be 934 wakeup(p->p_pptr);
984263bc 935 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0)
84204577 936 ksignal(p->p_pptr, SIGCHLD);
984263bc 937 goto out;
8ebcad3f 938 }
344ad853 939
984263bc 940 /*
344ad853
MD
941 * Otherwise the signal can interrupt the sleep.
942 */
943 goto run;
944 }
945
946 /*
947 * Process is in tsleep and is stopped
948 */
949 if (p->p_stat == SSLEEP && (p->p_flag & P_STOPPED)) {
950 /*
951 * If the process is stopped and is being traced, then no
952 * further action is necessary.
984263bc
MD
953 */
954 if (p->p_flag & P_TRACED)
955 goto out;
956
957 /*
344ad853
MD
958 * If the process is stopped and receives a KILL signal,
959 * make the process runnable.
984263bc
MD
960 */
961 if (sig == SIGKILL)
26a0694b 962 goto run;
984263bc 963
344ad853
MD
964 /*
965 * If the process is stopped and receives a CONT signal,
966 * then try to make the process runnable again.
967 */
984263bc
MD
968 if (prop & SA_CONT) {
969 /*
970 * If SIGCONT is default (or ignored), we continue the
971 * process but don't leave the signal in p_siglist, as
972 * it has no further action. If SIGCONT is held, we
973 * continue the process and leave the signal in
974 * p_siglist. If the process catches SIGCONT, let it
344ad853 975 * handle the signal itself.
984263bc
MD
976 */
977 if (action == SIG_DFL)
978 SIGDELSET(p->p_siglist, sig);
979 if (action == SIG_CATCH)
26a0694b 980 goto run;
984263bc 981
984263bc 982 /*
344ad853
MD
983 * Make runnable but do not break a tsleep unless
984 * some other signal was pending.
984263bc 985 */
344ad853
MD
986 goto run_no_break;
987 }
988
989 /*
990 * If the process is stopped and receives another STOP
991 * signal, we do not need to stop it again. If we did
992 * the shell could get confused.
993 */
994 if (prop & SA_STOP) {
984263bc
MD
995 SIGDELSET(p->p_siglist, sig);
996 goto out;
997 }
998
999 /*
344ad853
MD
1000 * Otherwise the process is sleeping interruptably but
1001 * is stopped, just set the P_BREAKTSLEEP flag and take
1002 * no further action. The next runnable action will wake
1003 * the process up.
984263bc 1004 */
344ad853 1005 p->p_flag |= P_BREAKTSLEEP;
984263bc 1006 goto out;
344ad853
MD
1007 }
1008
1009 /*
1010 * Otherwise the process is running
1011 *
1012 * SRUN, SIDL, SZOMB do nothing with the signal,
1013 * other than kicking ourselves if we are running.
1014 * It will either never be noticed, or noticed very soon.
1015 *
1016 * Note that p_thread may be NULL or may not be completely
1017 * initialized if the process is in the SIDL or SZOMB state.
1018 *
1019 * For SMP we may have to forward the request to another cpu.
1020 * YYY the MP lock prevents the target process from moving
1021 * to another cpu, see kern/kern_switch.c
1022 *
1023 * If the target thread is waiting on its message port,
1024 * wakeup the target thread so it can check (or ignore)
1025 * the new signal. YYY needs cleanup.
1026 */
1027 if (lp == lwkt_preempted_proc()) {
1028 signotify();
1029 } else if (p->p_stat == SRUN) {
1030 struct thread *td = p->p_thread;
1031
1032 KASSERT(td != NULL,
1033 ("pid %d NULL p_thread stat %d flags %08x",
1034 p->p_pid, p->p_stat, p->p_flag));
1035
984263bc 1036#ifdef SMP
344ad853
MD
1037 if (td->td_gd != mycpu)
1038 lwkt_send_ipiq(td->td_gd, signotify_remote, lp);
1039 else
984263bc 1040#endif
344ad853
MD
1041 if (td->td_msgport.mp_flags & MSGPORTF_WAITING)
1042 lwkt_schedule(td);
984263bc 1043 }
344ad853 1044 goto out;
984263bc 1045 /*NOTREACHED*/
984263bc 1046run:
344ad853
MD
1047 /*
1048 * Make runnable and break out of any tsleep as well.
1049 */
1050 p->p_flag |= P_BREAKTSLEEP;
1051run_no_break:
984263bc
MD
1052 setrunnable(p);
1053out:
e43a034f 1054 crit_exit();
984263bc
MD
1055}
1056
cb973d15
MD
1057#ifdef SMP
1058
1059/*
1060 * This function is called via an IPI. We will be in a critical section but
1061 * the MP lock will NOT be held. Also note that by the time the ipi message
1062 * gets to us the process 'p' (arg) may no longer be scheduled or even valid.
1063 */
1064static void
1065signotify_remote(void *arg)
1066{
553ea3c8 1067 struct lwp *lp = arg;
60be1d11 1068
553ea3c8 1069 if (lp == lwkt_preempted_proc()) {
235957ed 1070 signotify();
60be1d11 1071 } else {
553ea3c8 1072 struct thread *td = lp->lwp_thread;
60be1d11
MD
1073 if (td->td_msgport.mp_flags & MSGPORTF_WAITING)
1074 lwkt_schedule(td);
1075 }
cb973d15
MD
1076}
1077
1078#endif
1079
3a59f0f7
DX
1080static int
1081kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout)
1082{
1083 sigset_t savedmask, set;
1084 struct proc *p = curproc;
1085 int error, sig, hz, timevalid = 0;
1086 struct timespec rts, ets, ts;
1087 struct timeval tv;
1088
1089 error = 0;
1090 sig = 0;
1091 SIG_CANTMASK(waitset);
1092 savedmask = p->p_sigmask;
1093
1094 if (timeout) {
f8c41806
DX
1095 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 &&
1096 timeout->tv_nsec < 1000000000) {
3a59f0f7
DX
1097 timevalid = 1;
1098 getnanouptime(&rts);
1099 ets = rts;
1100 timespecadd(&ets, timeout);
1101 }
1102 }
1103
1104 for (;;) {
1105 set = p->p_siglist;
1106 SIGSETAND(set, waitset);
1107 if ((sig = sig_ffs(&set)) != 0) {
1108 SIGFILLSET(p->p_sigmask);
1109 SIGDELSET(p->p_sigmask, sig);
976f0bc5 1110 SIG_CANTMASK(p->p_sigmask);
3a59f0f7
DX
1111 sig = issignal(p);
1112 /*
1113 * It may be a STOP signal, in the case, issignal
1114 * returns 0, because we may stop there, and new
1115 * signal can come in, we should restart if we got
1116 * nothing.
1117 */
1118 if (sig == 0)
1119 continue;
1120 else
1121 break;
1122 }
1123
1124 /*
1125 * Previous checking got nothing, and we retried but still
1126 * got nothing, we should return the error status.
1127 */
1128 if (error)
1129 break;
1130
1131 /*
1132 * POSIX says this must be checked after looking for pending
1133 * signals.
1134 */
1135 if (timeout) {
1136 if (!timevalid) {
1137 error = EINVAL;
1138 break;
1139 }
1140 getnanouptime(&rts);
1141 if (timespeccmp(&rts, &ets, >=)) {
1142 error = EAGAIN;
1143 break;
1144 }
1145 ts = ets;
1146 timespecsub(&ts, &rts);
1147 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1148 hz = tvtohz_high(&tv);
1149 } else
1150 hz = 0;
1151
1152 p->p_sigmask = savedmask;
1153 SIGSETNAND(p->p_sigmask, waitset);
1154 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz);
1155 if (timeout) {
1156 if (error == ERESTART) {
1157 /* can not restart a timeout wait. */
1158 error = EINTR;
1159 } else if (error == EAGAIN) {
1160 /* will calculate timeout by ourself. */
1161 error = 0;
1162 }
1163 }
1164 /* Retry ... */
1165 }
1166
1167 p->p_sigmask = savedmask;
1168 if (sig) {
1169 error = 0;
1170 bzero(info, sizeof(*info));
1171 info->si_signo = sig;
1172 SIGDELSET(p->p_siglist, sig); /* take the signal! */
1e1bd00b
DX
1173
1174 if (sig == SIGKILL)
1175 sigexit(p, sig);
3a59f0f7
DX
1176 }
1177 return (error);
1178}
1179
1180int
753fd850 1181sys_sigtimedwait(struct sigtimedwait_args *uap)
3a59f0f7
DX
1182{
1183 struct timespec ts;
1184 struct timespec *timeout;
1185 sigset_t set;
1186 siginfo_t info;
1187 int error;
1188
1189 if (uap->timeout) {
1190 error = copyin(uap->timeout, &ts, sizeof(ts));
1191 if (error)
1192 return (error);
1193 timeout = &ts;
1194 } else {
1195 timeout = NULL;
1196 }
1197 error = copyin(uap->set, &set, sizeof(set));
1198 if (error)
1199 return (error);
1200 error = kern_sigtimedwait(set, &info, timeout);
1201 if (error)
1202 return (error);
1203 if (uap->info)
1204 error = copyout(&info, uap->info, sizeof(info));
1205 /* Repost if we got an error. */
1206 if (error)
84204577 1207 ksignal(curproc, info.si_signo);
3a59f0f7
DX
1208 else
1209 uap->sysmsg_result = info.si_signo;
1210 return (error);
1211}
1212
1213int
753fd850 1214sys_sigwaitinfo(struct sigwaitinfo_args *uap)
3a59f0f7
DX
1215{
1216 siginfo_t info;
1217 sigset_t set;
1218 int error;
1219
1220 error = copyin(uap->set, &set, sizeof(set));
1221 if (error)
1222 return (error);
1223 error = kern_sigtimedwait(set, &info, NULL);
1224 if (error)
1225 return (error);
1226 if (uap->info)
1227 error = copyout(&info, uap->info, sizeof(info));
1228 /* Repost if we got an error. */
1229 if (error)
84204577 1230 ksignal(curproc, info.si_signo);
3a59f0f7
DX
1231 else
1232 uap->sysmsg_result = info.si_signo;
1233 return (error);
1234}
1235
a94976ad
MD
1236/*
1237 * If the current process has received a signal that would interrupt a
1238 * system call, return EINTR or ERESTART as appropriate.
1239 */
1240int
1241iscaught(struct proc *p)
1242{
1243 int sig;
1244
1245 if (p) {
1246 if ((sig = CURSIG(p)) != 0) {
1247 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1248 return (EINTR);
1249 return (ERESTART);
1250 }
1251 }
1252 return(EWOULDBLOCK);
1253}
1254
984263bc
MD
1255/*
1256 * If the current process has received a signal (should be caught or cause
1257 * termination, should interrupt current syscall), return the signal number.
1258 * Stop signals with default action are processed immediately, then cleared;
1259 * they aren't returned. This is checked after each entry to the system for
1260 * a syscall or trap (though this can usually be done without calling issignal
1261 * by checking the pending signal masks in the CURSIG macro.) The normal call
1262 * sequence is
1263 *
bf189c26
MD
1264 * This routine is called via CURSIG/__cursig and the MP lock might not be
1265 * held. Obtain the MP lock for the duration of the operation.
1266 *
984263bc
MD
1267 * while (sig = CURSIG(curproc))
1268 * postsig(sig);
1269 */
1270int
8ebcad3f 1271issignal(struct proc *p)
984263bc
MD
1272{
1273 sigset_t mask;
1fd87d54 1274 int sig, prop;
984263bc 1275
bf189c26 1276 get_mplock();
984263bc
MD
1277 for (;;) {
1278 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
1279
1280 mask = p->p_siglist;
1281 SIGSETNAND(mask, p->p_sigmask);
1282 if (p->p_flag & P_PPWAIT)
1283 SIG_STOPSIGMASK(mask);
bf189c26
MD
1284 if (!SIGNOTEMPTY(mask)) { /* no signal to send */
1285 rel_mplock();
984263bc 1286 return (0);
bf189c26 1287 }
984263bc
MD
1288 sig = sig_ffs(&mask);
1289
1290 STOPEVENT(p, S_SIG, sig);
1291
1292 /*
1293 * We should see pending but ignored signals
1294 * only if P_TRACED was on when they were posted.
1295 */
1296 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
1297 SIGDELSET(p->p_siglist, sig);
1298 continue;
1299 }
344ad853 1300 if ((p->p_flag & P_TRACED) && (p->p_flag & P_PPWAIT) == 0) {
984263bc 1301 /*
344ad853
MD
1302 * If traced, always stop, and stay stopped until
1303 * released by the parent.
1304 *
1305 * NOTE: P_STOPPED may get cleared during the loop,
1306 * but we do not re-notify the parent if we have
1307 * to loop several times waiting for the parent
1308 * to let us continue.
984263bc
MD
1309 */
1310 p->p_xstat = sig;
344ad853
MD
1311 p->p_flag |= P_STOPPED;
1312 p->p_flag &= ~P_WAITED;
84204577 1313 ksignal(p->p_pptr, SIGCHLD);
984263bc 1314 do {
344ad853
MD
1315 tstop(p);
1316 } while (!trace_req(p) && (p->p_flag & P_TRACED));
1317 p->p_flag &= ~P_STOPPED;
984263bc
MD
1318
1319 /*
1320 * If parent wants us to take the signal,
1321 * then it will leave it in p->p_xstat;
1322 * otherwise we just look for signals again.
1323 */
1324 SIGDELSET(p->p_siglist, sig); /* clear old signal */
1325 sig = p->p_xstat;
1326 if (sig == 0)
1327 continue;
1328
1329 /*
1330 * Put the new signal into p_siglist. If the
1331 * signal is being masked, look for other signals.
1332 */
1333 SIGADDSET(p->p_siglist, sig);
1334 if (SIGISMEMBER(p->p_sigmask, sig))
1335 continue;
1336
1337 /*
1338 * If the traced bit got turned off, go back up
1339 * to the top to rescan signals. This ensures
1340 * that p_sig* and ps_sigact are consistent.
1341 */
1342 if ((p->p_flag & P_TRACED) == 0)
1343 continue;
1344 }
1345
1346 prop = sigprop(sig);
1347
1348 /*
1349 * Decide whether the signal should be returned.
1350 * Return the signal's number, or fall through
1351 * to clear it from the pending mask.
1352 */
1353 switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
984263bc
MD
1354 case (int)SIG_DFL:
1355 /*
1356 * Don't take default actions on system processes.
1357 */
1358 if (p->p_pid <= 1) {
1359#ifdef DIAGNOSTIC
1360 /*
1361 * Are you sure you want to ignore SIGSEGV
1362 * in init? XXX
1363 */
6ea70f76 1364 kprintf("Process (pid %lu) got signal %d\n",
984263bc
MD
1365 (u_long)p->p_pid, sig);
1366#endif
1367 break; /* == ignore */
1368 }
f758a39e
MD
1369
1370 /*
1371 * Handle the in-kernel checkpoint action
1372 */
1373 if (prop & SA_CKPT) {
0ba6fbbf 1374 checkpoint_signal_handler(p);
f758a39e
MD
1375 break;
1376 }
1377
984263bc
MD
1378 /*
1379 * If there is a pending stop signal to process
1380 * with default action, stop here,
1381 * then clear the signal. However,
1382 * if process is member of an orphaned
1383 * process group, ignore tty stop signals.
1384 */
1385 if (prop & SA_STOP) {
1386 if (p->p_flag & P_TRACED ||
1387 (p->p_pgrp->pg_jobc == 0 &&
1388 prop & SA_TTYSTOP))
1389 break; /* == ignore */
1390 p->p_xstat = sig;
344ad853
MD
1391 p->p_flag |= P_STOPPED;
1392 p->p_flag &= ~P_WAITED;
1393
984263bc 1394 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0)
84204577 1395 ksignal(p->p_pptr, SIGCHLD);
344ad853
MD
1396 while (p->p_flag & P_STOPPED) {
1397 tstop(p);
1398 }
984263bc
MD
1399 break;
1400 } else if (prop & SA_IGNORE) {
1401 /*
1402 * Except for SIGCONT, shouldn't get here.
1403 * Default action is to ignore; drop it.
1404 */
1405 break; /* == ignore */
8ebcad3f 1406 } else {
bf189c26 1407 rel_mplock();
984263bc 1408 return (sig);
8ebcad3f
MD
1409 }
1410
984263bc
MD
1411 /*NOTREACHED*/
1412
1413 case (int)SIG_IGN:
1414 /*
1415 * Masking above should prevent us ever trying
1416 * to take action on an ignored signal other
1417 * than SIGCONT, unless process is traced.
1418 */
1419 if ((prop & SA_CONT) == 0 &&
1420 (p->p_flag & P_TRACED) == 0)
6ea70f76 1421 kprintf("issignal\n");
984263bc
MD
1422 break; /* == ignore */
1423
1424 default:
1425 /*
1426 * This signal has an action, let
1427 * postsig() process it.
1428 */
bf189c26 1429 rel_mplock();
984263bc
MD
1430 return (sig);
1431 }
1432 SIGDELSET(p->p_siglist, sig); /* take the signal! */
1433 }
1434 /* NOTREACHED */
1435}
1436
984263bc
MD
1437/*
1438 * Take the action for the specified signal
1439 * from the current set of pending signals.
1440 */
1441void
8ebcad3f 1442postsig(int sig)
984263bc 1443{
bb3cd951
SS
1444 struct thread *td = curthread;
1445 struct proc *p = td->td_proc;
984263bc
MD
1446 struct sigacts *ps = p->p_sigacts;
1447 sig_t action;
1448 sigset_t returnmask;
1449 int code;
1450
1451 KASSERT(sig != 0, ("postsig"));
1452
1453 SIGDELSET(p->p_siglist, sig);
1454 action = ps->ps_sigact[_SIG_IDX(sig)];
1455#ifdef KTRACE
bb3cd951 1456 if (KTRPOINT(td, KTR_PSIG))
a9b80e23
MD
1457 ktrpsig(p, sig, action, p->p_flag & P_OLDMASK ?
1458 &p->p_oldsigmask : &p->p_sigmask, 0);
984263bc
MD
1459#endif
1460 STOPEVENT(p, S_SIG, sig);
1461
1462 if (action == SIG_DFL) {
1463 /*
1464 * Default action, where the default is to kill
1465 * the process. (Other cases were ignored above.)
1466 */
1467 sigexit(p, sig);
1468 /* NOTREACHED */
1469 } else {
1470 /*
1471 * If we get here, the signal must be caught.
1472 */
1473 KASSERT(action != SIG_IGN && !SIGISMEMBER(p->p_sigmask, sig),
1474 ("postsig action"));
1475 /*
1476 * Set the new mask value and also defer further
1477 * occurrences of this signal.
1478 *
1479 * Special case: user has done a sigsuspend. Here the
1480 * current mask is not of interest, but rather the
1481 * mask from before the sigsuspend is what we want
1482 * restored after the signal processing is completed.
1483 */
e43a034f 1484 crit_enter();
984263bc
MD
1485 if (p->p_flag & P_OLDMASK) {
1486 returnmask = p->p_oldsigmask;
1487 p->p_flag &= ~P_OLDMASK;
8ebcad3f 1488 } else {
984263bc 1489 returnmask = p->p_sigmask;
8ebcad3f 1490 }
984263bc
MD
1491
1492 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
1493 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1494 SIGADDSET(p->p_sigmask, sig);
1495
1496 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
1497 /*
65957d54 1498 * See kern_sigaction() for origin of this code.
984263bc
MD
1499 */
1500 SIGDELSET(p->p_sigcatch, sig);
1501 if (sig != SIGCONT &&
1502 sigprop(sig) & SA_IGNORE)
1503 SIGADDSET(p->p_sigignore, sig);
1504 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1505 }
e43a034f 1506 crit_exit();
984263bc
MD
1507 p->p_stats->p_ru.ru_nsignals++;
1508 if (p->p_sig != sig) {
1509 code = 0;
1510 } else {
1511 code = p->p_code;
1512 p->p_code = 0;
1513 p->p_sig = 0;
1514 }
1515 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
1516 }
1517}
1518
1519/*
1520 * Kill the current process for stated reason.
1521 */
1522void
8ebcad3f 1523killproc(struct proc *p, char *why)
984263bc
MD
1524{
1525 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm,
41c20dac 1526 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
84204577 1527 ksignal(p, SIGKILL);
984263bc
MD
1528}
1529
1530/*
1531 * Force the current process to exit with the specified signal, dumping core
1532 * if appropriate. We bypass the normal tests for masked and caught signals,
1533 * allowing unrecoverable failures to terminate the process without changing
1534 * signal state. Mark the accounting record with the signal termination.
1535 * If dumping core, save the signal number for the debugger. Calls exit and
1536 * does not return.
1537 */
1538void
41c20dac 1539sigexit(struct proc *p, int sig)
984263bc 1540{
984263bc
MD
1541 p->p_acflag |= AXSIG;
1542 if (sigprop(sig) & SA_CORE) {
1543 p->p_sig = sig;
1544 /*
1545 * Log signals which would cause core dumps
1546 * (Log as LOG_INFO to appease those who don't want
1547 * these messages.)
1548 * XXX : Todo, as well as euid, write out ruid too
1549 */
1550 if (coredump(p) == 0)
1551 sig |= WCOREFLAG;
1552 if (kern_logsigexit)
1553 log(LOG_INFO,
1554 "pid %d (%s), uid %d: exited on signal %d%s\n",
1555 p->p_pid, p->p_comm,
41c20dac 1556 p->p_ucred ? p->p_ucred->cr_uid : -1,
984263bc
MD
1557 sig &~ WCOREFLAG,
1558 sig & WCOREFLAG ? " (core dumped)" : "");
1559 }
41c20dac 1560 exit1(W_EXITCODE(0, sig));
984263bc
MD
1561 /* NOTREACHED */
1562}
1563
1564static char corefilename[MAXPATHLEN+1] = {"%N.core"};
1565SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
1566 sizeof(corefilename), "process corefile name format string");
1567
1568/*
1569 * expand_name(name, uid, pid)
1570 * Expand the name described in corefilename, using name, uid, and pid.
6ea70f76 1571 * corefilename is a kprintf-like string, with three format specifiers:
984263bc
MD
1572 * %N name of process ("name")
1573 * %P process id (pid)
1574 * %U user id (uid)
1575 * For example, "%N.core" is the default; they can be disabled completely
1576 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
1577 * This is controlled by the sysctl variable kern.corefile (see above).
1578 */
1579
1580static char *
8ebcad3f
MD
1581expand_name(const char *name, uid_t uid, pid_t pid)
1582{
984263bc
MD
1583 char *temp;
1584 char buf[11]; /* Buffer for pid/uid -- max 4B */
1585 int i, n;
1586 char *format = corefilename;
1587 size_t namelen;
1588
efda3bd0 1589 temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
984263bc
MD
1590 if (temp == NULL)
1591 return NULL;
1592 namelen = strlen(name);
1593 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
1594 int l;
1595 switch (format[i]) {
1596 case '%': /* Format character */
1597 i++;
1598 switch (format[i]) {
1599 case '%':
1600 temp[n++] = '%';
1601 break;
1602 case 'N': /* process name */
1603 if ((n + namelen) > MAXPATHLEN) {
1604 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1605 pid, name, uid, temp, name);
efda3bd0 1606 kfree(temp, M_TEMP);
984263bc
MD
1607 return NULL;
1608 }
1609 memcpy(temp+n, name, namelen);
1610 n += namelen;
1611 break;
1612 case 'P': /* process id */
f8c7a42d 1613 l = ksprintf(buf, "%u", pid);
984263bc
MD
1614 if ((n + l) > MAXPATHLEN) {
1615 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1616 pid, name, uid, temp, name);
efda3bd0 1617 kfree(temp, M_TEMP);
984263bc
MD
1618 return NULL;
1619 }
1620 memcpy(temp+n, buf, l);
1621 n += l;
1622 break;
1623 case 'U': /* user id */
f8c7a42d 1624 l = ksprintf(buf, "%u", uid);
984263bc
MD
1625 if ((n + l) > MAXPATHLEN) {
1626 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1627 pid, name, uid, temp, name);
efda3bd0 1628 kfree(temp, M_TEMP);
984263bc
MD
1629 return NULL;
1630 }
1631 memcpy(temp+n, buf, l);
1632 n += l;
1633 break;
1634 default:
1635 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
1636 }
1637 break;
1638 default:
1639 temp[n++] = format[i];
1640 }
1641 }
1642 temp[n] = '\0';
1643 return temp;
1644}
1645
1646/*
1647 * Dump a process' core. The main routine does some
1648 * policy checking, and creates the name of the coredump;
1649 * then it passes on a vnode and a size limit to the process-specific
1650 * coredump routine if there is one; if there _is not_ one, it returns
1651 * ENOSYS; otherwise it returns the error from the process-specific routine.
1652 */
1653
1654static int
dadab5e9 1655coredump(struct proc *p)
984263bc 1656{
dadab5e9
MD
1657 struct vnode *vp;
1658 struct ucred *cred = p->p_ucred;
984263bc 1659 struct flock lf;
fad57d0e 1660 struct nlookupdata nd;
984263bc
MD
1661 struct vattr vattr;
1662 int error, error1;
1663 char *name; /* name of corefile */
1664 off_t limit;
1665
1666 STOPEVENT(p, S_CORE, 0);
1667
1668 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0)
1669 return (EFAULT);
1670
1671 /*
1672 * Note that the bulk of limit checking is done after
1673 * the corefile is created. The exception is if the limit
1674 * for corefiles is 0, in which case we don't bother
1675 * creating the corefile at all. This layout means that
1676 * a corefile is truncated instead of not being created,
1677 * if it is larger than the limit.
1678 */
1679 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
1680 if (limit == 0)
50fd5388 1681 return EFBIG;
984263bc
MD
1682
1683 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
1684 if (name == NULL)
1685 return (EINVAL);
fad57d0e
MD
1686 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
1687 if (error == 0)
1688 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
efda3bd0 1689 kfree(name, M_TEMP);
fad57d0e
MD
1690 if (error) {
1691 nlookup_done(&nd);
984263bc 1692 return (error);
fad57d0e
MD
1693 }
1694 vp = nd.nl_open_vp;
1695 nd.nl_open_vp = NULL;
1696 nlookup_done(&nd);
984263bc 1697
a11aaa81 1698 vn_unlock(vp);
984263bc
MD
1699 lf.l_whence = SEEK_SET;
1700 lf.l_start = 0;
1701 lf.l_len = 0;
1702 lf.l_type = F_WRLCK;
71c18fe3 1703 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0);
984263bc
MD
1704 if (error)
1705 goto out2;
1706
1707 /* Don't dump to non-regular files or files with links. */
1708 if (vp->v_type != VREG ||
87de5057 1709 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) {
984263bc
MD
1710 error = EFAULT;
1711 goto out1;
1712 }
1713
1714 VATTR_NULL(&vattr);
ca466bae 1715 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
984263bc 1716 vattr.va_size = 0;
87de5057 1717 VOP_SETATTR(vp, &vattr, cred);
984263bc 1718 p->p_acflag |= ACORE;
a11aaa81 1719 vn_unlock(vp);
984263bc
MD
1720
1721 error = p->p_sysent->sv_coredump ?
fad57d0e 1722 p->p_sysent->sv_coredump(p, vp, limit) : ENOSYS;
984263bc
MD
1723
1724out1:
1725 lf.l_type = F_UNLCK;
71c18fe3 1726 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0);
984263bc 1727out2:
87de5057 1728 error1 = vn_close(vp, FWRITE);
984263bc
MD
1729 if (error == 0)
1730 error = error1;
1731 return (error);
1732}
1733
1734/*
1735 * Nonexistent system call-- signal process (may want to handle it).
1736 * Flag error in case process won't see signal immediately (blocked or ignored).
1737 */
984263bc
MD
1738/* ARGSUSED */
1739int
753fd850 1740sys_nosys(struct nosys_args *args)
984263bc 1741{
84204577 1742 ksignal(curproc, SIGSYS);
984263bc
MD
1743 return (EINVAL);
1744}
1745
1746/*
1747 * Send a SIGIO or SIGURG signal to a process or process group using
1748 * stored credentials rather than those of the current process.
1749 */
1750void
dadab5e9 1751pgsigio(struct sigio *sigio, int sig, int checkctty)
984263bc
MD
1752{
1753 if (sigio == NULL)
1754 return;
1755
1756 if (sigio->sio_pgid > 0) {
1757 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
1758 sigio->sio_proc))
84204577 1759 ksignal(sigio->sio_proc, sig);
984263bc
MD
1760 } else if (sigio->sio_pgid < 0) {
1761 struct proc *p;
1762
167e6ecb
MD
1763 lockmgr(&sigio->sio_pgrp->pg_lock, LK_EXCLUSIVE);
1764 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
984263bc
MD
1765 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
1766 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
84204577 1767 ksignal(p, sig);
167e6ecb
MD
1768 }
1769 lockmgr(&sigio->sio_pgrp->pg_lock, LK_RELEASE);
984263bc
MD
1770 }
1771}
1772
1773static int
1774filt_sigattach(struct knote *kn)
1775{
1776 struct proc *p = curproc;
1777
1778 kn->kn_ptr.p_proc = p;
1779 kn->kn_flags |= EV_CLEAR; /* automatically set */
1780
1781 /* XXX lock the proc here while adding to the list? */
1782 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext);
1783
1784 return (0);
1785}
1786
1787static void
1788filt_sigdetach(struct knote *kn)
1789{
1790 struct proc *p = kn->kn_ptr.p_proc;
1791
1792 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext);
1793}
1794
1795/*
1796 * signal knotes are shared with proc knotes, so we apply a mask to
1797 * the hint in order to differentiate them from process hints. This
1798 * could be avoided by using a signal-specific knote list, but probably
1799 * isn't worth the trouble.
1800 */
1801static int
1802filt_signal(struct knote *kn, long hint)
1803{
984263bc
MD
1804 if (hint & NOTE_SIGNAL) {
1805 hint &= ~NOTE_SIGNAL;
1806
1807 if (kn->kn_id == hint)
1808 kn->kn_data++;
1809 }
1810 return (kn->kn_data != 0);
1811}