kernel - Add per-process token, adjust signal code to use it.
[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 $
40 */
41
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42#include "opt_ktrace.h"
43
44#include <sys/param.h>
dadab5e9 45#include <sys/systm.h>
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46#include <sys/kernel.h>
47#include <sys/sysproto.h>
48#include <sys/signalvar.h>
49#include <sys/resourcevar.h>
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50#include <sys/vnode.h>
51#include <sys/event.h>
52#include <sys/proc.h>
fad57d0e 53#include <sys/nlookup.h>
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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>
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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>
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70
71#include <sys/signal2.h>
e43a034f 72#include <sys/thread2.h>
984263bc 73
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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);
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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
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86static int kern_sigtimedwait(sigset_t set, siginfo_t *info,
87 struct timespec *timeout);
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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 };
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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 */
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104#define CANSIGNAL(q, sig) \
105 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \
106 ((sig) == SIGCONT && (q)->p_session == curproc->p_session))
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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 || \
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113 (ruid) == (q)->p_ucred->cr_ruid || \
114 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \
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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");
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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 */
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138#define SA_CKPT 0x80 /* checkpoint process */
139
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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 */
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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
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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
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229/*
230 * No requirements.
231 */
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232int
233kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact)
984263bc 234{
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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;
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239
240 if (sig <= 0 || sig > _SIG_MAXSIG)
241 return (EINVAL);
242
5686ec5a 243 lwkt_gettoken(&p->p_token);
ac7ea585 244
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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;
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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)
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264 oact->sa_flags |= SA_NOCLDWAIT;
265 }
266 if (act) {
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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 }
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276#if 0
277 /* (not needed, SIG_DFL forces action to occur) */
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278 if (act->sa_flags & SA_MAILBOX) {
279 lwkt_reltoken(&p->p_token);
7c1212ec 280 return (EINVAL);
5686ec5a 281 }
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282#endif
283 }
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284
285 /*
286 * Change setting atomically.
287 */
e43a034f 288 crit_enter();
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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);
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316 if (act->sa_flags & SA_MAILBOX)
317 SIGADDSET(ps->ps_sigmailbox, sig);
318 else
319 SIGDELSET(ps->ps_sigmailbox, sig);
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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;
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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 }
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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);
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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 }
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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);
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373 return (0);
374}
375
984263bc 376int
753fd850 377sys_sigaction(struct sigaction_args *uap)
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378{
379 struct sigaction act, oact;
1fd87d54 380 struct sigaction *actp, *oactp;
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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);
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391 if (oactp && !error) {
392 error = copyout(oactp, uap->oact, sizeof(oact));
393 }
394 return (error);
395}
396
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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;
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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
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421 lp = ONLY_LWP_IN_PROC(p);
422
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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);
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436 }
437 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
438 }
aa6c3de6 439
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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;
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448 /*
449 * Reset no zombies if child dies flag as Solaris does.
450 */
b1b4e5a6 451 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
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452}
453
454/*
65957d54 455 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
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456 *
457 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
e43a034f 458 * p == curproc.
984263bc 459 */
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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;
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466 int error;
467
5686ec5a 468 lwkt_gettoken(&p->p_token);
ac7ea585 469
984263bc 470 if (oset != NULL)
08f2f1bb 471 *oset = lp->lwp_sigmask;
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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);
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479 break;
480 case SIG_UNBLOCK:
08f2f1bb 481 SIGSETNAND(lp->lwp_sigmask, *set);
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482 break;
483 case SIG_SETMASK:
484 SIG_CANTMASK(*set);
08f2f1bb 485 lp->lwp_sigmask = *set;
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486 break;
487 default:
488 error = EINVAL;
489 break;
490 }
491 }
ac7ea585 492
5686ec5a 493 lwkt_reltoken(&p->p_token);
ac7ea585 494
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495 return (error);
496}
497
498/*
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499 * sigprocmask()
500 *
501 * MPSAFE
984263bc 502 */
984263bc 503int
753fd850 504sys_sigprocmask(struct sigprocmask_args *uap)
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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);
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518 if (osetp && !error) {
519 error = copyout(osetp, uap->oset, sizeof(oset));
520 }
521 return (error);
522}
523
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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
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534 return (0);
535}
536
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537/*
538 * MPSAFE
539 */
984263bc 540int
753fd850 541sys_sigpending(struct sigpending_args *uap)
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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}
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552
553/*
554 * Suspend process until signal, providing mask to be set
65957d54 555 * in the meantime.
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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;
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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)
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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
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588 *
589 * MPSAFE
65957d54 590 */
984263bc 591int
753fd850 592sys_sigsuspend(struct sigsuspend_args *uap)
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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;
8ebcad3f 695 } else {
984263bc
MD
696 pgrp = pgfind(pgid);
697 if (pgrp == NULL)
698 return (ESRCH);
699 }
167e6ecb 700 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
984263bc 701 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
f026f3b0 702 if (p->p_pid <= 1 ||
416d05d7
SS
703 p->p_stat == SZOMB ||
704 (p->p_flag & P_SYSTEM) ||
f026f3b0 705 !CANSIGNAL(p, sig)) {
984263bc 706 continue;
f026f3b0 707 }
8fa76237 708 ++info.nfound;
984263bc 709 if (sig)
84204577 710 ksignal(p, sig);
984263bc 711 }
167e6ecb 712 lockmgr(&pgrp->pg_lock, LK_RELEASE);
984263bc 713 }
8fa76237
MD
714 return (info.nfound ? 0 : ESRCH);
715}
716
717static int
718killpg_all_callback(struct proc *p, void *data)
719{
720 struct killpg_info *info = data;
721
722 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) ||
723 p == curproc || !CANSIGNAL(p, info->sig)) {
724 return (0);
725 }
726 ++info->nfound;
727 if (info->sig)
84204577 728 ksignal(p, info->sig);
8fa76237 729 return(0);
984263bc
MD
730}
731
73e40cb2
MD
732/*
733 * Send a general signal to a process or LWPs within that process. Note
734 * that new signals cannot be sent if a process is exiting.
ac7ea585
VS
735 *
736 * No requirements.
73e40cb2 737 */
984263bc 738int
f9366a82 739kern_kill(int sig, pid_t pid, lwpid_t tid)
984263bc 740{
ac7ea585
VS
741 int t;
742
65957d54 743 if ((u_int)sig > _SIG_MAXSIG)
984263bc 744 return (EINVAL);
ac7ea585
VS
745
746 lwkt_gettoken(&proc_token);
747
65957d54 748 if (pid > 0) {
505ba680 749 struct proc *p;
9e758ef5
SW
750 struct lwp *lp = NULL;
751
984263bc 752 /* kill single process */
ac7ea585
VS
753 if ((p = pfind(pid)) == NULL) {
754 lwkt_reltoken(&proc_token);
984263bc 755 return (ESRCH);
ac7ea585 756 }
5686ec5a
MD
757 PHOLD(p);
758 lwkt_gettoken(&p->p_token);
ac7ea585 759 if (!CANSIGNAL(p, sig)) {
5686ec5a
MD
760 lwkt_reltoken(&p->p_token);
761 PRELE(p);
ac7ea585 762 lwkt_reltoken(&proc_token);
984263bc 763 return (EPERM);
ac7ea585 764 }
73e40cb2
MD
765
766 /*
767 * NOP if the process is exiting. Note that lwpsignal() is
768 * called directly with P_WEXIT set to kill individual LWPs
769 * during exit, which is allowed.
770 */
ac7ea585 771 if (p->p_flag & P_WEXIT) {
5686ec5a
MD
772 lwkt_reltoken(&p->p_token);
773 PRELE(p);
ac7ea585 774 lwkt_reltoken(&proc_token);
73e40cb2 775 return (0);
ac7ea585 776 }
f9366a82 777 if (tid != -1) {
3e291793 778 lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, tid);
ac7ea585 779 if (lp == NULL) {
5686ec5a
MD
780 lwkt_reltoken(&p->p_token);
781 PRELE(p);
ac7ea585 782 lwkt_reltoken(&proc_token);
f9366a82 783 return (ESRCH);
ac7ea585 784 }
f9366a82 785 }
65957d54 786 if (sig)
f9366a82 787 lwpsignal(p, lp, sig);
5686ec5a
MD
788 lwkt_reltoken(&p->p_token);
789 PRELE(p);
ac7ea585 790 lwkt_reltoken(&proc_token);
984263bc
MD
791 return (0);
792 }
5686ec5a 793
f9366a82
SS
794 /*
795 * If we come here, pid is a special broadcast pid.
796 * This doesn't mix with a tid.
797 */
ac7ea585
VS
798 if (tid != -1) {
799 lwkt_reltoken(&proc_token);
f9366a82 800 return (EINVAL);
ac7ea585 801 }
65957d54 802 switch (pid) {
984263bc 803 case -1: /* broadcast signal */
ac7ea585
VS
804 t = (dokillpg(sig, 0, 1));
805 break;
984263bc 806 case 0: /* signal own process group */
ac7ea585
VS
807 t = (dokillpg(sig, 0, 0));
808 break;
984263bc 809 default: /* negative explicit process group */
ac7ea585
VS
810 t = (dokillpg(sig, -pid, 0));
811 break;
984263bc 812 }
ac7ea585
VS
813 lwkt_reltoken(&proc_token);
814 return t;
984263bc
MD
815}
816
984263bc 817int
753fd850 818sys_kill(struct kill_args *uap)
984263bc 819{
65957d54
DRJ
820 int error;
821
f9366a82
SS
822 error = kern_kill(uap->signum, uap->pid, -1);
823 return (error);
824}
825
826int
827sys_lwp_kill(struct lwp_kill_args *uap)
828{
829 int error;
830 pid_t pid = uap->pid;
831
832 /*
833 * A tid is mandatory for lwp_kill(), otherwise
834 * you could simply use kill().
835 */
836 if (uap->tid == -1)
837 return (EINVAL);
838
839 /*
840 * To save on a getpid() function call for intra-process
841 * signals, pid == -1 means current process.
842 */
843 if (pid == -1)
844 pid = curproc->p_pid;
65957d54 845
f9366a82 846 error = kern_kill(uap->signum, pid, uap->tid);
65957d54 847 return (error);
984263bc 848}
984263bc
MD
849
850/*
851 * Send a signal to a process group.
852 */
853void
41c20dac 854gsignal(int pgid, int sig)
984263bc
MD
855{
856 struct pgrp *pgrp;
857
858 if (pgid && (pgrp = pgfind(pgid)))
859 pgsignal(pgrp, sig, 0);
860}
861
862/*
863 * Send a signal to a process group. If checktty is 1,
864 * limit to members which have a controlling terminal.
167e6ecb
MD
865 *
866 * pg_lock interlocks against a fork that might be in progress, to
867 * ensure that the new child process picks up the signal.
984263bc
MD
868 */
869void
8ebcad3f 870pgsignal(struct pgrp *pgrp, int sig, int checkctty)
984263bc 871{
1fd87d54 872 struct proc *p;
984263bc 873
167e6ecb
MD
874 if (pgrp) {
875 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
876 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
984263bc 877 if (checkctty == 0 || p->p_flag & P_CONTROLT)
84204577 878 ksignal(p, sig);
167e6ecb
MD
879 }
880 lockmgr(&pgrp->pg_lock, LK_RELEASE);
881 }
984263bc
MD
882}
883
884/*
04d84fc2
MD
885 * Send a signal caused by a trap to the current lwp. If it will be caught
886 * immediately, deliver it with correct code. Otherwise, post it normally.
887 *
888 * These signals may ONLY be delivered to the specified lwp and may never
889 * be delivered to the process generically.
984263bc
MD
890 */
891void
08f2f1bb 892trapsignal(struct lwp *lp, int sig, u_long code)
984263bc 893{
08f2f1bb 894 struct proc *p = lp->lwp_proc;
dadab5e9 895 struct sigacts *ps = p->p_sigacts;
984263bc 896
7c1212ec
MD
897 /*
898 * If we are a virtual kernel running an emulated user process
899 * context, switch back to the virtual kernel context before
900 * trying to post the signal.
901 */
39005e16 902 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
287ebb09 903 struct trapframe *tf = lp->lwp_md.md_regs;
7c1212ec 904 tf->tf_trapno = 0;
287ebb09 905 vkernel_trap(lp, tf);
7c1212ec
MD
906 }
907
908
984263bc 909 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
08f2f1bb
SS
910 !SIGISMEMBER(lp->lwp_sigmask, sig)) {
911 lp->lwp_ru.ru_nsignals++;
984263bc 912#ifdef KTRACE
08f2f1bb 913 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
9fb04d14 914 ktrpsig(lp, sig, ps->ps_sigact[_SIG_IDX(sig)],
08f2f1bb 915 &lp->lwp_sigmask, code);
984263bc
MD
916#endif
917 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
08f2f1bb
SS
918 &lp->lwp_sigmask, code);
919 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
984263bc 920 if (!SIGISMEMBER(ps->ps_signodefer, sig))
08f2f1bb 921 SIGADDSET(lp->lwp_sigmask, sig);
984263bc
MD
922 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
923 /*
65957d54 924 * See kern_sigaction() for origin of this code.
984263bc
MD
925 */
926 SIGDELSET(p->p_sigcatch, sig);
927 if (sig != SIGCONT &&
928 sigprop(sig) & SA_IGNORE)
929 SIGADDSET(p->p_sigignore, sig);
930 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
931 }
932 } else {
7d20a8ff
SS
933 lp->lwp_code = code; /* XXX for core dump/debugger */
934 lp->lwp_sig = sig; /* XXX to verify code */
7278a846 935 lwpsignal(p, lp, sig);
984263bc
MD
936 }
937}
938
939/*
1699b0b8
SS
940 * Find a suitable lwp to deliver the signal to.
941 *
942 * Returns NULL if all lwps hold the signal blocked.
943 */
944static struct lwp *
945find_lwp_for_signal(struct proc *p, int sig)
946{
947 struct lwp *lp;
948 struct lwp *run, *sleep, *stop;
949
950 /*
951 * If the running/preempted thread belongs to the proc to which
952 * the signal is being delivered and this thread does not block
953 * the signal, then we can avoid a context switch by delivering
954 * the signal to this thread, because it will return to userland
955 * soon anyways.
956 */
957 lp = lwkt_preempted_proc();
958 if (lp != NULL && lp->lwp_proc == p && !SIGISMEMBER(lp->lwp_sigmask, sig))
959 return (lp);
960
961 run = sleep = stop = NULL;
962 FOREACH_LWP_IN_PROC(lp, p) {
963 /*
964 * If the signal is being blocked by the lwp, then this
965 * lwp is not eligible for receiving the signal.
966 */
967 if (SIGISMEMBER(lp->lwp_sigmask, sig))
968 continue;
969
970 switch (lp->lwp_stat) {
971 case LSRUN:
972 run = lp;
973 break;
974
975 case LSSTOP:
976 stop = lp;
977 break;
978
979 case LSSLEEP:
980 if (lp->lwp_flag & LWP_SINTR)
981 sleep = lp;
982 break;
983 }
984 }
985
986 if (run != NULL)
987 return (run);
988 else if (sleep != NULL)
989 return (sleep);
990 else
991 return (stop);
992}
993
994/*
984263bc
MD
995 * Send the signal to the process. If the signal has an action, the action
996 * is usually performed by the target process rather than the caller; we add
997 * the signal to the set of pending signals for the process.
998 *
999 * Exceptions:
1000 * o When a stop signal is sent to a sleeping process that takes the
1001 * default action, the process is stopped without awakening it.
1002 * o SIGCONT restarts stopped processes (or puts them back to sleep)
1003 * regardless of the signal action (eg, blocked or ignored).
1004 *
1005 * Other ignored signals are discarded immediately.
ac7ea585
VS
1006 *
1007 * No requirements.
984263bc
MD
1008 */
1009void
84204577 1010ksignal(struct proc *p, int sig)
984263bc 1011{
7278a846
SS
1012 lwpsignal(p, NULL, sig);
1013}
1014
1015/*
1016 * The core for ksignal. lp may be NULL, then a suitable thread
1017 * will be chosen. If not, lp MUST be a member of p.
ac7ea585
VS
1018 *
1019 * No requirements.
7278a846
SS
1020 */
1021void
1022lwpsignal(struct proc *p, struct lwp *lp, int sig)
1023{
e43a034f 1024 int prop;
cb973d15 1025 sig_t action;
984263bc
MD
1026
1027 if (sig > _SIG_MAXSIG || sig <= 0) {
7278a846
SS
1028 kprintf("lwpsignal: signal %d\n", sig);
1029 panic("lwpsignal signal number");
984263bc
MD
1030 }
1031
7278a846
SS
1032 KKASSERT(lp == NULL || lp->lwp_proc == p);
1033
5686ec5a 1034 lwkt_gettoken(&p->p_token);
ac7ea585 1035
984263bc
MD
1036 prop = sigprop(sig);
1037
1038 /*
1039 * If proc is traced, always give parent a chance;
1040 * if signal event is tracked by procfs, give *that*
1041 * a chance, as well.
1042 */
8ebcad3f 1043 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) {
984263bc 1044 action = SIG_DFL;
8ebcad3f 1045 } else {
984263bc 1046 /*
73e40cb2
MD
1047 * Do not try to deliver signals to an exiting lwp. Note
1048 * that we must still deliver the signal if P_WEXIT is set
1049 * in the process flags.
984263bc 1050 */
ac7ea585 1051 if (lp && (lp->lwp_flag & LWP_WEXIT)) {
5686ec5a 1052 lwkt_reltoken(&p->p_token);
e3161323 1053 return;
ac7ea585 1054 }
e3161323
MD
1055
1056 /*
8f433481 1057 * If the signal is being ignored, then we forget about
e3161323
MD
1058 * it immediately. NOTE: We don't set SIGCONT in p_sigignore,
1059 * and if it is set to SIG_IGN, action will be SIG_DFL here.
1060 */
ac7ea585 1061 if (SIGISMEMBER(p->p_sigignore, sig)) {
5686ec5a 1062 lwkt_reltoken(&p->p_token);
984263bc 1063 return;
ac7ea585 1064 }
1699b0b8 1065 if (SIGISMEMBER(p->p_sigcatch, sig))
984263bc
MD
1066 action = SIG_CATCH;
1067 else
1068 action = SIG_DFL;
1069 }
1070
344ad853
MD
1071 /*
1072 * If continuing, clear any pending STOP signals.
1073 */
984263bc
MD
1074 if (prop & SA_CONT)
1075 SIG_STOPSIGMASK(p->p_siglist);
9d63d5c0 1076
984263bc
MD
1077 if (prop & SA_STOP) {
1078 /*
1079 * If sending a tty stop signal to a member of an orphaned
1080 * process group, discard the signal here if the action
1081 * is default; don't stop the process below if sleeping,
1082 * and don't clear any pending SIGCONT.
1083 */
1084 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
8ebcad3f 1085 action == SIG_DFL) {
5686ec5a 1086 lwkt_reltoken(&p->p_token);
984263bc 1087 return;
8ebcad3f 1088 }
984263bc 1089 SIG_CONTSIGMASK(p->p_siglist);
cc162105 1090 p->p_flag &= ~P_CONTINUED;
984263bc 1091 }
e43a034f
MD
1092
1093 crit_enter();
1094
1699b0b8 1095 if (p->p_stat == SSTOP) {
984263bc 1096 /*
04d84fc2
MD
1097 * Nobody can handle this signal, add it to the lwp or
1098 * process pending list
344ad853 1099 */
04d84fc2
MD
1100 if (lp)
1101 SIGADDSET(lp->lwp_siglist, sig);
1102 else
1103 SIGADDSET(p->p_siglist, sig);
344ad853 1104
344ad853
MD
1105 /*
1106 * If the process is stopped and is being traced, then no
1107 * further action is necessary.
984263bc
MD
1108 */
1109 if (p->p_flag & P_TRACED)
1110 goto out;
1111
1112 /*
344ad853
MD
1113 * If the process is stopped and receives a KILL signal,
1114 * make the process runnable.
984263bc 1115 */
9a379a4a
SS
1116 if (sig == SIGKILL) {
1117 proc_unstop(p);
7278a846 1118 goto active_process;
9a379a4a 1119 }
984263bc 1120
344ad853
MD
1121 /*
1122 * If the process is stopped and receives a CONT signal,
1123 * then try to make the process runnable again.
1124 */
984263bc
MD
1125 if (prop & SA_CONT) {
1126 /*
1127 * If SIGCONT is default (or ignored), we continue the
1128 * process but don't leave the signal in p_siglist, as
1129 * it has no further action. If SIGCONT is held, we
1130 * continue the process and leave the signal in
1131 * p_siglist. If the process catches SIGCONT, let it
344ad853 1132 * handle the signal itself.
984263bc 1133 */
1699b0b8 1134 /* XXX what if the signal is being held blocked? */
cc162105
PA
1135 p->p_flag |= P_CONTINUED;
1136 wakeup(p->p_pptr);
984263bc
MD
1137 if (action == SIG_DFL)
1138 SIGDELSET(p->p_siglist, sig);
9a379a4a 1139 proc_unstop(p);
984263bc 1140 if (action == SIG_CATCH)
1699b0b8 1141 goto active_process;
9a379a4a 1142 goto out;
344ad853
MD
1143 }
1144
1145 /*
1146 * If the process is stopped and receives another STOP
1147 * signal, we do not need to stop it again. If we did
1148 * the shell could get confused.
6ed57d3d
SS
1149 *
1150 * However, if the current/preempted lwp is part of the
1151 * process receiving the signal, we need to keep it,
1152 * so that this lwp can stop in issignal() later, as
1153 * we don't want to wait until it reaches userret!
344ad853
MD
1154 */
1155 if (prop & SA_STOP) {
7278a846
SS
1156 if (lwkt_preempted_proc() == NULL ||
1157 lwkt_preempted_proc()->lwp_proc != p)
6ed57d3d 1158 SIGDELSET(p->p_siglist, sig);
984263bc
MD
1159 }
1160
1161 /*
1699b0b8
SS
1162 * Otherwise the process is stopped and it received some
1163 * signal, which does not change its stopped state.
7278a846
SS
1164 *
1165 * We have to select one thread to set LWP_BREAKTSLEEP,
1166 * so that the current signal will break the sleep
1167 * as soon as a SA_CONT signal will unstop the process.
984263bc 1168 */
7278a846
SS
1169 if (lp == NULL)
1170 lp = find_lwp_for_signal(p, sig);
1171 if (lp != NULL &&
1172 (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP))
1173 lp->lwp_flag |= LWP_BREAKTSLEEP;
984263bc 1174 goto out;
1699b0b8
SS
1175
1176 /* NOTREACHED */
344ad853 1177 }
1699b0b8
SS
1178 /* else not stopped */
1179active_process:
1180
04d84fc2
MD
1181 /*
1182 * Never deliver a lwp-specific signal to a random lwp.
1183 */
1184 if (lp == NULL) {
7278a846 1185 lp = find_lwp_for_signal(p, sig);
04d84fc2
MD
1186 if (lp && SIGISMEMBER(lp->lwp_sigmask, sig))
1187 lp = NULL;
1188 }
344ad853
MD
1189
1190 /*
04d84fc2
MD
1191 * Deliver to the process generically if (1) the signal is being
1192 * sent to any thread or (2) we could not find a thread to deliver
1193 * it to.
344ad853 1194 */
04d84fc2 1195 if (lp == NULL) {
1699b0b8
SS
1196 SIGADDSET(p->p_siglist, sig);
1197 goto out;
1198 }
344ad853 1199
04d84fc2
MD
1200 /*
1201 * Deliver to a specific LWP whether it masks it or not. It will
1202 * not be dispatched if masked but we must still deliver it.
1203 */
1699b0b8
SS
1204 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
1205 (p->p_flag & P_TRACED) == 0) {
1206 p->p_nice = NZERO;
1207 }
344ad853 1208
1699b0b8
SS
1209 /*
1210 * If the process receives a STOP signal which indeed needs to
1211 * stop the process, do so. If the process chose to catch the
1212 * signal, it will be treated like any other signal.
1213 */
1214 if ((prop & SA_STOP) && action == SIG_DFL) {
1215 /*
1216 * If a child holding parent blocked, stopping
1217 * could cause deadlock. Take no action at this
1218 * time.
1219 */
1220 if (p->p_flag & P_PPWAIT) {
1221 SIGADDSET(p->p_siglist, sig);
1222 goto out;
1223 }
1224
1225 /*
1226 * Do not actually try to manipulate the process, but simply
1227 * stop it. Lwps will stop as soon as they safely can.
1228 */
1229 p->p_xstat = sig;
f33e8653 1230 proc_stop(p);
1699b0b8 1231 goto out;
984263bc 1232 }
1699b0b8 1233
344ad853 1234 /*
1699b0b8 1235 * If it is a CONT signal with default action, just ignore it.
344ad853 1236 */
1699b0b8
SS
1237 if ((prop & SA_CONT) && action == SIG_DFL)
1238 goto out;
1239
1240 /*
1241 * Mark signal pending at this specific thread.
1242 */
1243 SIGADDSET(lp->lwp_siglist, sig);
1244
7278a846
SS
1245 lwp_signotify(lp);
1246
1247out:
5686ec5a 1248 lwkt_reltoken(&p->p_token);
7278a846
SS
1249 crit_exit();
1250}
1251
98c2b8ac 1252/*
5686ec5a 1253 * p->p_token must be held
98c2b8ac
MD
1254 */
1255static void
7278a846
SS
1256lwp_signotify(struct lwp *lp)
1257{
5686ec5a 1258 ASSERT_LWKT_TOKEN_HELD(&lp->lwp_proc->p_token);
7278a846 1259 crit_enter();
98c2b8ac 1260
7278a846 1261 if (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP) {
1699b0b8
SS
1262 /*
1263 * Thread is in tsleep.
1264 */
1265
1266 /*
1267 * If the thread is sleeping uninterruptibly
1268 * we can't interrupt the sleep... the signal will
1269 * be noticed when the lwp returns through
1270 * trap() or syscall().
7278a846 1271 *
1699b0b8
SS
1272 * Otherwise the signal can interrupt the sleep.
1273 *
1274 * If the process is traced, the lwp will handle the
1275 * tracing in issignal() when it returns to userland.
1276 */
7278a846
SS
1277 if (lp->lwp_flag & LWP_SINTR) {
1278 /*
1279 * Make runnable and break out of any tsleep as well.
1280 */
1281 lp->lwp_flag |= LWP_BREAKTSLEEP;
1282 setrunnable(lp);
1283 }
1699b0b8
SS
1284 } else {
1285 /*
1286 * Otherwise the thread is running
1287 *
1288 * LSRUN does nothing with the signal, other than kicking
1289 * ourselves if we are running.
1290 * SZOMB and SIDL mean that it will either never be noticed,
1291 * or noticed very soon.
1292 *
1293 * Note that lwp_thread may be NULL or may not be completely
1294 * initialized if the process is in the SIDL or SZOMB state.
1295 *
1296 * For SMP we may have to forward the request to another cpu.
1297 * YYY the MP lock prevents the target process from moving
1298 * to another cpu, see kern/kern_switch.c
1299 *
1300 * If the target thread is waiting on its message port,
1301 * wakeup the target thread so it can check (or ignore)
1302 * the new signal. YYY needs cleanup.
1303 */
1304 if (lp == lwkt_preempted_proc()) {
1305 signotify();
1306 } else if (lp->lwp_stat == LSRUN) {
1307 struct thread *td = lp->lwp_thread;
f64b567c 1308 struct proc *p __debugvar = lp->lwp_proc;
1699b0b8
SS
1309
1310 KASSERT(td != NULL,
1311 ("pid %d/%d NULL lwp_thread stat %d flags %08x/%08x",
1312 p->p_pid, lp->lwp_tid, lp->lwp_stat,
1313 p->p_flag, lp->lwp_flag));
1314
a22c590e
MD
1315 /*
1316 * To prevent a MP race with TDF_SINTR we must
1317 * schedule the thread on the correct cpu.
1318 */
1699b0b8 1319#ifdef SMP
c5d0ecf8
MD
1320 if (td->td_gd != mycpu) {
1321 LWPHOLD(lp);
1699b0b8 1322 lwkt_send_ipiq(td->td_gd, signotify_remote, lp);
c5d0ecf8 1323 } else
1699b0b8 1324#endif
a22c590e 1325 if (td->td_flags & TDF_SINTR)
1699b0b8
SS
1326 lwkt_schedule(td);
1327 }
1328 }
e43a034f 1329 crit_exit();
984263bc
MD
1330}
1331
cb973d15
MD
1332#ifdef SMP
1333
1334/*
1335 * This function is called via an IPI. We will be in a critical section but
d041353d
MD
1336 * the MP lock will NOT be held. The passed lp will be held.
1337 *
1338 * We must essentially repeat the code at the end of lwp_signotify(),
1339 * in particular rechecking all races. If we are still not on the
1340 * correct cpu we leave the lwp ref intact and continue the chase.
1341 *
1342 * XXX this may still not be entirely correct, since we are checking
1343 * lwp_stat asynchronously.
cb973d15
MD
1344 */
1345static void
1346signotify_remote(void *arg)
1347{
553ea3c8 1348 struct lwp *lp = arg;
d041353d 1349 thread_t td;
60be1d11 1350
553ea3c8 1351 if (lp == lwkt_preempted_proc()) {
235957ed 1352 signotify();
d041353d
MD
1353 } else if (lp->lwp_stat == LSRUN) {
1354 /*
1355 * To prevent a MP race with TDF_SINTR we must
1356 * schedule the thread on the correct cpu.
1357 */
1358 td = lp->lwp_thread;
1359 if (td->td_gd != mycpu) {
1360 lwkt_send_ipiq(td->td_gd, signotify_remote, lp);
1361 return;
1362 /* NOT REACHED */
1363 }
a22c590e 1364 if (td->td_flags & TDF_SINTR)
60be1d11
MD
1365 lwkt_schedule(td);
1366 }
c5d0ecf8 1367 LWPRELE(lp);
cb973d15
MD
1368}
1369
1370#endif
1371
98c2b8ac 1372/*
5686ec5a 1373 * Caller must hold p->p_token
98c2b8ac 1374 */
9a379a4a 1375void
f33e8653 1376proc_stop(struct proc *p)
9a379a4a 1377{
f33e8653 1378 struct lwp *lp;
7278a846 1379
5686ec5a 1380 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
98c2b8ac
MD
1381 crit_enter();
1382
7278a846 1383 /* If somebody raced us, be happy with it */
98c2b8ac
MD
1384 if (p->p_stat == SSTOP || p->p_stat == SZOMB) {
1385 crit_exit();
7278a846 1386 return;
98c2b8ac 1387 }
9a379a4a 1388 p->p_stat = SSTOP;
7278a846 1389
7278a846
SS
1390 FOREACH_LWP_IN_PROC(lp, p) {
1391 switch (lp->lwp_stat) {
1392 case LSSTOP:
1393 /*
1394 * Do nothing, we are already counted in
1395 * p_nstopped.
1396 */
1397 break;
1398
1399 case LSSLEEP:
1400 /*
1401 * We're sleeping, but we will stop before
1402 * returning to userspace, so count us
f33e8653
SS
1403 * as stopped as well. We set LWP_WSTOP
1404 * to signal the lwp that it should not
1405 * increase p_nstopped when reaching tstop().
7278a846 1406 */
f33e8653
SS
1407 if ((lp->lwp_flag & LWP_WSTOP) == 0) {
1408 lp->lwp_flag |= LWP_WSTOP;
1409 ++p->p_nstopped;
1410 }
7278a846
SS
1411 break;
1412
1413 case LSRUN:
7278a846 1414 /*
f33e8653
SS
1415 * We might notify ourself, but that's not
1416 * a problem.
7278a846 1417 */
f33e8653 1418 lwp_signotify(lp);
7278a846
SS
1419 break;
1420 }
1421 }
1422
f33e8653
SS
1423 if (p->p_nstopped == p->p_nthreads) {
1424 p->p_flag &= ~P_WAITED;
1425 wakeup(p->p_pptr);
1426 if ((p->p_pptr->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1427 ksignal(p->p_pptr, SIGCHLD);
1428 }
1429 crit_exit();
9a379a4a
SS
1430}
1431
98c2b8ac
MD
1432/*
1433 * Caller must hold proc_token
1434 */
9a379a4a
SS
1435void
1436proc_unstop(struct proc *p)
1437{
7278a846 1438 struct lwp *lp;
9a379a4a 1439
5686ec5a 1440 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
98c2b8ac
MD
1441 crit_enter();
1442
1443 if (p->p_stat != SSTOP) {
1444 crit_exit();
7278a846 1445 return;
98c2b8ac 1446 }
f33e8653 1447
9a379a4a 1448 p->p_stat = SACTIVE;
7278a846
SS
1449
1450 FOREACH_LWP_IN_PROC(lp, p) {
1451 switch (lp->lwp_stat) {
1452 case LSRUN:
1453 /*
1454 * Uh? Not stopped? Well, I guess that's okay.
1455 */
1456 if (bootverbose)
1457 kprintf("proc_unstop: lwp %d/%d not sleeping\n",
1458 p->p_pid, lp->lwp_tid);
1459 break;
1460
7278a846
SS
1461 case LSSLEEP:
1462 /*
1463 * Still sleeping. Don't bother waking it up.
f33e8653
SS
1464 * However, if this thread was counted as
1465 * stopped, undo this.
1466 *
1467 * Nevertheless we call setrunnable() so that it
1468 * will wake up in case a signal or timeout arrived
1469 * in the meantime.
7278a846 1470 */
f33e8653 1471 if (lp->lwp_flag & LWP_WSTOP) {
a5ff9d37 1472 lp->lwp_flag &= ~LWP_WSTOP;
f33e8653
SS
1473 --p->p_nstopped;
1474 } else {
1475 if (bootverbose)
1476 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n",
1477 p->p_pid, lp->lwp_tid);
1478 }
1479 /* FALLTHROUGH */
1480
1481 case LSSTOP:
1482 setrunnable(lp);
7278a846 1483 break;
f33e8653 1484
7278a846
SS
1485 }
1486 }
f33e8653 1487 crit_exit();
9a379a4a
SS
1488}
1489
ac7ea585
VS
1490/*
1491 * No requirements.
ac7ea585 1492 */
3a59f0f7
DX
1493static int
1494kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout)
1495{
1496 sigset_t savedmask, set;
1497 struct proc *p = curproc;
08f2f1bb 1498 struct lwp *lp = curthread->td_lwp;
3a59f0f7
DX
1499 int error, sig, hz, timevalid = 0;
1500 struct timespec rts, ets, ts;
1501 struct timeval tv;
1502
1503 error = 0;
1504 sig = 0;
c077b601
MD
1505 ets.tv_sec = 0; /* silence compiler warning */
1506 ets.tv_nsec = 0; /* silence compiler warning */
3a59f0f7 1507 SIG_CANTMASK(waitset);
08f2f1bb 1508 savedmask = lp->lwp_sigmask;
3a59f0f7
DX
1509
1510 if (timeout) {
f8c41806
DX
1511 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 &&
1512 timeout->tv_nsec < 1000000000) {
3a59f0f7
DX
1513 timevalid = 1;
1514 getnanouptime(&rts);
1515 ets = rts;
1516 timespecadd(&ets, timeout);
1517 }
1518 }
1519
1520 for (;;) {
aa6c3de6 1521 set = lwp_sigpend(lp);
3a59f0f7
DX
1522 SIGSETAND(set, waitset);
1523 if ((sig = sig_ffs(&set)) != 0) {
08f2f1bb
SS
1524 SIGFILLSET(lp->lwp_sigmask);
1525 SIGDELSET(lp->lwp_sigmask, sig);
1526 SIG_CANTMASK(lp->lwp_sigmask);
e473f776 1527 sig = issignal(lp, 1);
3a59f0f7
DX
1528 /*
1529 * It may be a STOP signal, in the case, issignal
1530 * returns 0, because we may stop there, and new
1531 * signal can come in, we should restart if we got
1532 * nothing.
1533 */
1534 if (sig == 0)
1535 continue;
1536 else
1537 break;
1538 }
1539
1540 /*
1541 * Previous checking got nothing, and we retried but still
1542 * got nothing, we should return the error status.
1543 */
1544 if (error)
1545 break;
1546
1547 /*
1548 * POSIX says this must be checked after looking for pending
1549 * signals.
1550 */
1551 if (timeout) {
c077b601 1552 if (timevalid == 0) {
3a59f0f7
DX
1553 error = EINVAL;
1554 break;
1555 }
1556 getnanouptime(&rts);
1557 if (timespeccmp(&rts, &ets, >=)) {
1558 error = EAGAIN;
1559 break;
1560 }
1561 ts = ets;
1562 timespecsub(&ts, &rts);
1563 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1564 hz = tvtohz_high(&tv);
5686ec5a 1565 } else {
3a59f0f7 1566 hz = 0;
5686ec5a 1567 }
3a59f0f7 1568
08f2f1bb
SS
1569 lp->lwp_sigmask = savedmask;
1570 SIGSETNAND(lp->lwp_sigmask, waitset);
b1b4e5a6
SS
1571 /*
1572 * We won't ever be woken up. Instead, our sleep will
1573 * be broken in lwpsignal().
1574 */
3a59f0f7
DX
1575 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz);
1576 if (timeout) {
1577 if (error == ERESTART) {
1578 /* can not restart a timeout wait. */
1579 error = EINTR;
1580 } else if (error == EAGAIN) {
1581 /* will calculate timeout by ourself. */
1582 error = 0;
1583 }
1584 }
1585 /* Retry ... */
1586 }
1587
08f2f1bb 1588 lp->lwp_sigmask = savedmask;
3a59f0f7
DX
1589 if (sig) {
1590 error = 0;
1591 bzero(info, sizeof(*info));
1592 info->si_signo = sig;
aa6c3de6 1593 lwp_delsig(lp, sig); /* take the signal! */
1e1bd00b 1594
2883d2d8 1595 if (sig == SIGKILL) {
b276424c 1596 sigexit(lp, sig);
2883d2d8
MD
1597 /* NOT REACHED */
1598 }
3a59f0f7 1599 }
ac7ea585 1600
3a59f0f7
DX
1601 return (error);
1602}
1603
3919ced0
MD
1604/*
1605 * MPALMOSTSAFE
1606 */
3a59f0f7 1607int
753fd850 1608sys_sigtimedwait(struct sigtimedwait_args *uap)
3a59f0f7
DX
1609{
1610 struct timespec ts;
1611 struct timespec *timeout;
1612 sigset_t set;
1613 siginfo_t info;
1614 int error;
1615
1616 if (uap->timeout) {
1617 error = copyin(uap->timeout, &ts, sizeof(ts));
1618 if (error)
1619 return (error);
1620 timeout = &ts;
1621 } else {
1622 timeout = NULL;
1623 }
1624 error = copyin(uap->set, &set, sizeof(set));
1625 if (error)
1626 return (error);
1627 error = kern_sigtimedwait(set, &info, timeout);
1628 if (error)
1629 return (error);
1630 if (uap->info)
1631 error = copyout(&info, uap->info, sizeof(info));
1632 /* Repost if we got an error. */
7278a846
SS
1633 /*
1634 * XXX lwp
1635 *
1636 * This could transform a thread-specific signal to another
1637 * thread / process pending signal.
1638 */
3919ced0 1639 if (error) {
84204577 1640 ksignal(curproc, info.si_signo);
3919ced0 1641 } else {
3a59f0f7 1642 uap->sysmsg_result = info.si_signo;
3919ced0 1643 }
3a59f0f7
DX
1644 return (error);
1645}
1646
3919ced0
MD
1647/*
1648 * MPALMOSTSAFE
1649 */
3a59f0f7 1650int
753fd850 1651sys_sigwaitinfo(struct sigwaitinfo_args *uap)
3a59f0f7
DX
1652{
1653 siginfo_t info;
1654 sigset_t set;
1655 int error;
1656
1657 error = copyin(uap->set, &set, sizeof(set));
1658 if (error)
1659 return (error);
1660 error = kern_sigtimedwait(set, &info, NULL);
1661 if (error)
1662 return (error);
1663 if (uap->info)
1664 error = copyout(&info, uap->info, sizeof(info));
1665 /* Repost if we got an error. */
7278a846
SS
1666 /*
1667 * XXX lwp
1668 *
1669 * This could transform a thread-specific signal to another
1670 * thread / process pending signal.
1671 */
3919ced0 1672 if (error) {
84204577 1673 ksignal(curproc, info.si_signo);
3919ced0 1674 } else {
3a59f0f7 1675 uap->sysmsg_result = info.si_signo;
3919ced0 1676 }
3a59f0f7
DX
1677 return (error);
1678}
1679
984263bc 1680/*
a94976ad
MD
1681 * If the current process has received a signal that would interrupt a
1682 * system call, return EINTR or ERESTART as appropriate.
1683 */
1684int
08f2f1bb 1685iscaught(struct lwp *lp)
a94976ad 1686{
08f2f1bb 1687 struct proc *p = lp->lwp_proc;
a94976ad
MD
1688 int sig;
1689
1690 if (p) {
08f2f1bb 1691 if ((sig = CURSIG(lp)) != 0) {
a94976ad
MD
1692 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1693 return (EINTR);
1694 return (ERESTART);
1695 }
1696 }
1697 return(EWOULDBLOCK);
1698}
1699
1700/*
984263bc
MD
1701 * If the current process has received a signal (should be caught or cause
1702 * termination, should interrupt current syscall), return the signal number.
1703 * Stop signals with default action are processed immediately, then cleared;
1704 * they aren't returned. This is checked after each entry to the system for
1705 * a syscall or trap (though this can usually be done without calling issignal
5686ec5a 1706 * by checking the pending signal masks in the CURSIG macro).
984263bc 1707 *
5686ec5a
MD
1708 * This routine is called via CURSIG/__cursig. We will acquire and release
1709 * p->p_token but if the caller needs to interlock the test the caller must
1710 * also hold p->p_token.
bf189c26 1711 *
984263bc
MD
1712 * while (sig = CURSIG(curproc))
1713 * postsig(sig);
5686ec5a
MD
1714 *
1715 * MPSAFE
984263bc
MD
1716 */
1717int
e473f776 1718issignal(struct lwp *lp, int maytrace)
984263bc 1719{
08f2f1bb 1720 struct proc *p = lp->lwp_proc;
984263bc 1721 sigset_t mask;
1fd87d54 1722 int sig, prop;
984263bc 1723
5686ec5a 1724 lwkt_gettoken(&p->p_token);
98c2b8ac 1725
984263bc
MD
1726 for (;;) {
1727 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
1728
e473f776
SS
1729 /*
1730 * If this process is supposed to stop, stop this thread.
1731 */
1732 if (p->p_stat == SSTOP)
1733 tstop();
1734
aa6c3de6 1735 mask = lwp_sigpend(lp);
08f2f1bb 1736 SIGSETNAND(mask, lp->lwp_sigmask);
984263bc
MD
1737 if (p->p_flag & P_PPWAIT)
1738 SIG_STOPSIGMASK(mask);
1699b0b8 1739 if (SIGISEMPTY(mask)) { /* no signal to send */
5686ec5a 1740 lwkt_reltoken(&p->p_token);
984263bc 1741 return (0);
bf189c26 1742 }
984263bc
MD
1743 sig = sig_ffs(&mask);
1744
1745 STOPEVENT(p, S_SIG, sig);
1746
1747 /*
1748 * We should see pending but ignored signals
1749 * only if P_TRACED was on when they were posted.
1750 */
1751 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
aa6c3de6 1752 lwp_delsig(lp, sig);
984263bc
MD
1753 continue;
1754 }
e473f776 1755 if (maytrace && (p->p_flag & P_TRACED) && (p->p_flag & P_PPWAIT) == 0) {
984263bc 1756 /*
344ad853
MD
1757 * If traced, always stop, and stay stopped until
1758 * released by the parent.
1759 *
164b8401 1760 * NOTE: SSTOP may get cleared during the loop,
344ad853
MD
1761 * but we do not re-notify the parent if we have
1762 * to loop several times waiting for the parent
1763 * to let us continue.
164b8401
SS
1764 *
1765 * XXX not sure if this is still true
984263bc
MD
1766 */
1767 p->p_xstat = sig;
f33e8653 1768 proc_stop(p);
984263bc 1769 do {
9a379a4a 1770 tstop();
344ad853 1771 } while (!trace_req(p) && (p->p_flag & P_TRACED));
984263bc
MD
1772
1773 /*
1774 * If parent wants us to take the signal,
1775 * then it will leave it in p->p_xstat;
1776 * otherwise we just look for signals again.
1777 */
aa6c3de6 1778 lwp_delsig(lp, sig); /* clear old signal */
984263bc
MD
1779 sig = p->p_xstat;
1780 if (sig == 0)
1781 continue;
1782
1783 /*
1784 * Put the new signal into p_siglist. If the
1785 * signal is being masked, look for other signals.
1699b0b8
SS
1786 *
1787 * XXX lwp might need a call to ksignal()
984263bc
MD
1788 */
1789 SIGADDSET(p->p_siglist, sig);
08f2f1bb 1790 if (SIGISMEMBER(lp->lwp_sigmask, sig))
984263bc
MD
1791 continue;
1792
1793 /*
1794 * If the traced bit got turned off, go back up
1795 * to the top to rescan signals. This ensures
1796 * that p_sig* and ps_sigact are consistent.
1797 */
1798 if ((p->p_flag & P_TRACED) == 0)
1799 continue;
1800 }
1801
1802 prop = sigprop(sig);
1803
1804 /*
1805 * Decide whether the signal should be returned.
1806 * Return the signal's number, or fall through
1807 * to clear it from the pending mask.
1808 */
16094a36
MD
1809 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
1810 case (intptr_t)SIG_DFL:
984263bc
MD
1811 /*
1812 * Don't take default actions on system processes.
1813 */
1814 if (p->p_pid <= 1) {
1815#ifdef DIAGNOSTIC
1816 /*
1817 * Are you sure you want to ignore SIGSEGV
1818 * in init? XXX
1819 */
6ea70f76 1820 kprintf("Process (pid %lu) got signal %d\n",
984263bc
MD
1821 (u_long)p->p_pid, sig);
1822#endif
1823 break; /* == ignore */
1824 }
f758a39e
MD
1825
1826 /*
1827 * Handle the in-kernel checkpoint action
1828 */
1829 if (prop & SA_CKPT) {
7d20a8ff 1830 checkpoint_signal_handler(lp);
f758a39e
MD
1831 break;
1832 }
1833
984263bc
MD
1834 /*
1835 * If there is a pending stop signal to process
1836 * with default action, stop here,
1837 * then clear the signal. However,
1838 * if process is member of an orphaned
1839 * process group, ignore tty stop signals.
1840 */
1841 if (prop & SA_STOP) {
1842 if (p->p_flag & P_TRACED ||
1843 (p->p_pgrp->pg_jobc == 0 &&
1844 prop & SA_TTYSTOP))
1845 break; /* == ignore */
680b21e7 1846 p->p_xstat = sig;
f33e8653 1847 proc_stop(p);
e473f776 1848 tstop();
984263bc
MD
1849 break;
1850 } else if (prop & SA_IGNORE) {
1851 /*
1852 * Except for SIGCONT, shouldn't get here.
1853 * Default action is to ignore; drop it.
1854 */
1855 break; /* == ignore */
8ebcad3f 1856 } else {
5686ec5a 1857 lwkt_reltoken(&p->p_token);
984263bc 1858 return (sig);
8ebcad3f
MD
1859 }
1860
984263bc
MD
1861 /*NOTREACHED*/
1862
16094a36 1863 case (intptr_t)SIG_IGN:
984263bc
MD
1864 /*
1865 * Masking above should prevent us ever trying
1866 * to take action on an ignored signal other
1867 * than SIGCONT, unless process is traced.
1868 */
1869 if ((prop & SA_CONT) == 0 &&
1870 (p->p_flag & P_TRACED) == 0)
6ea70f76 1871 kprintf("issignal\n");
984263bc
MD
1872 break; /* == ignore */
1873
1874 default:
1875 /*
1876 * This signal has an action, let
1877 * postsig() process it.
1878 */
5686ec5a 1879 lwkt_reltoken(&p->p_token);
984263bc
MD
1880 return (sig);
1881 }
aa6c3de6 1882 lwp_delsig(lp, sig); /* take the signal! */
984263bc
MD
1883 }
1884 /* NOTREACHED */
1885}
1886
1887/*
984263bc
MD
1888 * Take the action for the specified signal
1889 * from the current set of pending signals.
1890 */
1891void
8ebcad3f 1892postsig(int sig)
984263bc 1893{
08f2f1bb
SS
1894 struct lwp *lp = curthread->td_lwp;
1895 struct proc *p = lp->lwp_proc;
984263bc
MD
1896 struct sigacts *ps = p->p_sigacts;
1897 sig_t action;
1898 sigset_t returnmask;
1899 int code;
1900
1901 KASSERT(sig != 0, ("postsig"));
1902
6ac7d3ce
SG
1903 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
1904
7c1212ec
MD
1905 /*
1906 * If we are a virtual kernel running an emulated user process
1907 * context, switch back to the virtual kernel context before
1908 * trying to post the signal.
1909 */
39005e16 1910 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
287ebb09 1911 struct trapframe *tf = lp->lwp_md.md_regs;
7c1212ec 1912 tf->tf_trapno = 0;
287ebb09 1913 vkernel_trap(lp, tf);
7c1212ec
MD
1914 }
1915
aa6c3de6 1916 lwp_delsig(lp, sig);
984263bc
MD
1917 action = ps->ps_sigact[_SIG_IDX(sig)];
1918#ifdef KTRACE
08f2f1bb 1919 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
9fb04d14 1920 ktrpsig(lp, sig, action, lp->lwp_flag & LWP_OLDMASK ?
08f2f1bb 1921 &lp->lwp_oldsigmask : &lp->lwp_sigmask, 0);
984263bc
MD
1922#endif
1923 STOPEVENT(p, S_SIG, sig);
1924
1925 if (action == SIG_DFL) {
1926 /*
1927 * Default action, where the default is to kill
1928 * the process. (Other cases were ignored above.)
1929 */
b276424c 1930 sigexit(lp, sig);
984263bc
MD
1931 /* NOTREACHED */
1932 } else {
1933 /*
1934 * If we get here, the signal must be caught.
1935 */
08f2f1bb 1936 KASSERT(action != SIG_IGN && !SIGISMEMBER(lp->lwp_sigmask, sig),
984263bc 1937 ("postsig action"));
7c1212ec
MD
1938
1939 crit_enter();
1940
1941 /*
1942 * Reset the signal handler if asked to
1943 */
1944 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
1945 /*
1946 * See kern_sigaction() for origin of this code.
1947 */
1948 SIGDELSET(p->p_sigcatch, sig);
1949 if (sig != SIGCONT &&
1950 sigprop(sig) & SA_IGNORE)
1951 SIGADDSET(p->p_sigignore, sig);
1952 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1953 }
1954
1955 /*
1956 * Handle the mailbox case. Copyout to the appropriate
1957 * location but do not generate a signal frame. The system
1958 * call simply returns EINTR and the user is responsible for
1959 * polling the mailbox.
1960 */
1961 if (SIGISMEMBER(ps->ps_sigmailbox, sig)) {
1962 int sig_copy = sig;
1963 copyout(&sig_copy, (void *)action, sizeof(int));
1964 curproc->p_flag |= P_MAILBOX;
1965 crit_exit();
1966 goto done;
1967 }
1968
984263bc 1969 /*
7c1212ec
MD
1970 * Set the signal mask and calculate the mask to restore
1971 * when the signal function returns.
984263bc
MD
1972 *
1973 * Special case: user has done a sigsuspend. Here the
1974 * current mask is not of interest, but rather the
1975 * mask from before the sigsuspend is what we want
1976 * restored after the signal processing is completed.
1977 */
08f2f1bb
SS
1978 if (lp->lwp_flag & LWP_OLDMASK) {
1979 returnmask = lp->lwp_oldsigmask;
1980 lp->lwp_flag &= ~LWP_OLDMASK;
8ebcad3f 1981 } else {
08f2f1bb 1982 returnmask = lp->lwp_sigmask;
8ebcad3f 1983 }
08f2f1bb
SS
1984
1985 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
984263bc 1986 if (!SIGISMEMBER(ps->ps_signodefer, sig))
08f2f1bb 1987 SIGADDSET(lp->lwp_sigmask, sig);
984263bc 1988
e43a034f 1989 crit_exit();
08f2f1bb 1990 lp->lwp_ru.ru_nsignals++;
7d20a8ff 1991 if (lp->lwp_sig != sig) {
984263bc
MD
1992 code = 0;
1993 } else {
7d20a8ff
SS
1994 code = lp->lwp_code;
1995 lp->lwp_code = 0;
1996 lp->lwp_sig = 0;
984263bc
MD
1997 }
1998 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
1999 }
7c1212ec
MD
2000done:
2001 ;
984263bc
MD
2002}
2003
2004/*
2005 * Kill the current process for stated reason.
2006 */
2007void
8ebcad3f 2008killproc(struct proc *p, char *why)
984263bc 2009{
7c1212ec
MD
2010 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n",
2011 p->p_pid, p->p_comm,
41c20dac 2012 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
84204577 2013 ksignal(p, SIGKILL);
984263bc
MD
2014}
2015
2016/*
2017 * Force the current process to exit with the specified signal, dumping core
2018 * if appropriate. We bypass the normal tests for masked and caught signals,
2019 * allowing unrecoverable failures to terminate the process without changing
2020 * signal state. Mark the accounting record with the signal termination.
2021 * If dumping core, save the signal number for the debugger. Calls exit and
2022 * does not return.
2883d2d8
MD
2023 *
2024 * This routine does not return.
984263bc
MD
2025 */
2026void
b276424c 2027sigexit(struct lwp *lp, int sig)
984263bc 2028{
b276424c 2029 struct proc *p = lp->lwp_proc;
7d20a8ff 2030
984263bc
MD
2031 p->p_acflag |= AXSIG;
2032 if (sigprop(sig) & SA_CORE) {
7d20a8ff 2033 lp->lwp_sig = sig;
984263bc
MD
2034 /*
2035 * Log signals which would cause core dumps
2036 * (Log as LOG_INFO to appease those who don't want
2037 * these messages.)
2038 * XXX : Todo, as well as euid, write out ruid too
2039 */
7d20a8ff 2040 if (coredump(lp, sig) == 0)
984263bc
MD
2041 sig |= WCOREFLAG;
2042 if (kern_logsigexit)
2043 log(LOG_INFO,
2044 "pid %d (%s), uid %d: exited on signal %d%s\n",
2045 p->p_pid, p->p_comm,
41c20dac 2046 p->p_ucred ? p->p_ucred->cr_uid : -1,
984263bc
MD
2047 sig &~ WCOREFLAG,
2048 sig & WCOREFLAG ? " (core dumped)" : "");
2049 }
41c20dac 2050 exit1(W_EXITCODE(0, sig));
984263bc
MD
2051 /* NOTREACHED */
2052}
2053
2054static char corefilename[MAXPATHLEN+1] = {"%N.core"};
2055SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
2056 sizeof(corefilename), "process corefile name format string");
2057
2058/*
2059 * expand_name(name, uid, pid)
2060 * Expand the name described in corefilename, using name, uid, and pid.
6ea70f76 2061 * corefilename is a kprintf-like string, with three format specifiers:
984263bc
MD
2062 * %N name of process ("name")
2063 * %P process id (pid)
2064 * %U user id (uid)
2065 * For example, "%N.core" is the default; they can be disabled completely
2066 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
2067 * This is controlled by the sysctl variable kern.corefile (see above).
2068 */
2069
2070static char *
8ebcad3f
MD
2071expand_name(const char *name, uid_t uid, pid_t pid)
2072{
984263bc
MD
2073 char *temp;
2074 char buf[11]; /* Buffer for pid/uid -- max 4B */
2075 int i, n;
2076 char *format = corefilename;
2077 size_t namelen;
2078
efda3bd0 2079 temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
984263bc
MD
2080 if (temp == NULL)
2081 return NULL;
2082 namelen = strlen(name);
2083 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
2084 int l;
2085 switch (format[i]) {
2086 case '%': /* Format character */
2087 i++;
2088 switch (format[i]) {
2089 case '%':
2090 temp[n++] = '%';
2091 break;
2092 case 'N': /* process name */
2093 if ((n + namelen) > MAXPATHLEN) {
2094 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2095 pid, name, uid, temp, name);
efda3bd0 2096 kfree(temp, M_TEMP);
984263bc
MD
2097 return NULL;
2098 }
2099 memcpy(temp+n, name, namelen);
2100 n += namelen;
2101 break;
2102 case 'P': /* process id */
f8c7a42d 2103 l = ksprintf(buf, "%u", pid);
984263bc
MD
2104 if ((n + l) > MAXPATHLEN) {
2105 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2106 pid, name, uid, temp, name);
efda3bd0 2107 kfree(temp, M_TEMP);
984263bc
MD
2108 return NULL;
2109 }
2110 memcpy(temp+n, buf, l);
2111 n += l;
2112 break;
2113 case 'U': /* user id */
f8c7a42d 2114 l = ksprintf(buf, "%u", uid);
984263bc
MD
2115 if ((n + l) > MAXPATHLEN) {
2116 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2117 pid, name, uid, temp, name);
efda3bd0 2118 kfree(temp, M_TEMP);
984263bc
MD
2119 return NULL;
2120 }
2121 memcpy(temp+n, buf, l);
2122 n += l;
2123 break;
2124 default:
2125 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
2126 }
2127 break;
2128 default:
2129 temp[n++] = format[i];
2130 }
2131 }
2132 temp[n] = '\0';
2133 return temp;
2134}
2135
2136/*
2137 * Dump a process' core. The main routine does some
2138 * policy checking, and creates the name of the coredump;
2139 * then it passes on a vnode and a size limit to the process-specific
2140 * coredump routine if there is one; if there _is not_ one, it returns
2141 * ENOSYS; otherwise it returns the error from the process-specific routine.
7d20a8ff
SS
2142 *
2143 * The parameter `lp' is the lwp which triggered the coredump.
984263bc
MD
2144 */
2145
2146static int
7d20a8ff 2147coredump(struct lwp *lp, int sig)
984263bc 2148{
7d20a8ff 2149 struct proc *p = lp->lwp_proc;
dadab5e9
MD
2150 struct vnode *vp;
2151 struct ucred *cred = p->p_ucred;
984263bc 2152 struct flock lf;
fad57d0e 2153 struct nlookupdata nd;
984263bc
MD
2154 struct vattr vattr;
2155 int error, error1;
2156 char *name; /* name of corefile */
2157 off_t limit;
2158
2159 STOPEVENT(p, S_CORE, 0);
2160
2161 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0)
2162 return (EFAULT);
2163
2164 /*
2165 * Note that the bulk of limit checking is done after
2166 * the corefile is created. The exception is if the limit
2167 * for corefiles is 0, in which case we don't bother
2168 * creating the corefile at all. This layout means that
2169 * a corefile is truncated instead of not being created,
2170 * if it is larger than the limit.
2171 */
2172 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
2173 if (limit == 0)
50fd5388 2174 return EFBIG;
984263bc
MD
2175
2176 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
2177 if (name == NULL)
2178 return (EINVAL);
fad57d0e
MD
2179 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
2180 if (error == 0)
2181 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
efda3bd0 2182 kfree(name, M_TEMP);
fad57d0e
MD
2183 if (error) {
2184 nlookup_done(&nd);
984263bc 2185 return (error);
fad57d0e
MD
2186 }
2187 vp = nd.nl_open_vp;
2188 nd.nl_open_vp = NULL;
2189 nlookup_done(&nd);
984263bc 2190
a11aaa81 2191 vn_unlock(vp);
984263bc
MD
2192 lf.l_whence = SEEK_SET;
2193 lf.l_start = 0;
2194 lf.l_len = 0;
2195 lf.l_type = F_WRLCK;
71c18fe3 2196 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0);
984263bc
MD
2197 if (error)
2198 goto out2;
2199
2200 /* Don't dump to non-regular files or files with links. */
2201 if (vp->v_type != VREG ||
87de5057 2202 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) {
984263bc
MD
2203 error = EFAULT;
2204 goto out1;
2205 }
2206
9d2a4e5d
MD
2207 /* Don't dump to files current user does not own */
2208 if (vattr.va_uid != p->p_ucred->cr_uid) {
2209 error = EFAULT;
2210 goto out1;
2211 }
2212
984263bc 2213 VATTR_NULL(&vattr);
ca466bae 2214 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
984263bc 2215 vattr.va_size = 0;
87de5057 2216 VOP_SETATTR(vp, &vattr, cred);
984263bc 2217 p->p_acflag |= ACORE;
a11aaa81 2218 vn_unlock(vp);
984263bc
MD
2219
2220 error = p->p_sysent->sv_coredump ?
7d20a8ff 2221 p->p_sysent->sv_coredump(lp, sig, vp, limit) : ENOSYS;
984263bc
MD
2222
2223out1:
2224 lf.l_type = F_UNLCK;
71c18fe3 2225 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0);
984263bc 2226out2:
87de5057 2227 error1 = vn_close(vp, FWRITE);
984263bc
MD
2228 if (error == 0)
2229 error = error1;
2230 return (error);
2231}
2232
2233/*
2234 * Nonexistent system call-- signal process (may want to handle it).
2235 * Flag error in case process won't see signal immediately (blocked or ignored).
3919ced0
MD
2236 *
2237 * MPALMOSTSAFE
984263bc 2238 */
984263bc
MD
2239/* ARGSUSED */
2240int
753fd850 2241sys_nosys(struct nosys_args *args)
984263bc 2242{
7278a846 2243 lwpsignal(curproc, curthread->td_lwp, SIGSYS);
984263bc
MD
2244 return (EINVAL);
2245}
2246
2247/*
2248 * Send a SIGIO or SIGURG signal to a process or process group using
2249 * stored credentials rather than those of the current process.
2250 */
2251void
dadab5e9 2252pgsigio(struct sigio *sigio, int sig, int checkctty)
984263bc
MD
2253{
2254 if (sigio == NULL)
2255 return;
2256
2257 if (sigio->sio_pgid > 0) {
2258 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
2259 sigio->sio_proc))
84204577 2260 ksignal(sigio->sio_proc, sig);
984263bc
MD
2261 } else if (sigio->sio_pgid < 0) {
2262 struct proc *p;
2263
167e6ecb
MD
2264 lockmgr(&sigio->sio_pgrp->pg_lock, LK_EXCLUSIVE);
2265 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
984263bc
MD
2266 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
2267 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
84204577 2268 ksignal(p, sig);
167e6ecb
MD
2269 }
2270 lockmgr(&sigio->sio_pgrp->pg_lock, LK_RELEASE);
984263bc
MD
2271 }
2272}
2273
2274static int
2275filt_sigattach(struct knote *kn)
2276{
2277 struct proc *p = curproc;
2278
2279 kn->kn_ptr.p_proc = p;
2280 kn->kn_flags |= EV_CLEAR; /* automatically set */
2281
2282 /* XXX lock the proc here while adding to the list? */
5b22f1a7 2283 knote_insert(&p->p_klist, kn);
984263bc
MD
2284
2285 return (0);
2286}
2287
2288static void
2289filt_sigdetach(struct knote *kn)
2290{
2291 struct proc *p = kn->kn_ptr.p_proc;
2292
5b22f1a7 2293 knote_remove(&p->p_klist, kn);
984263bc
MD
2294}
2295
2296/*
2297 * signal knotes are shared with proc knotes, so we apply a mask to
2298 * the hint in order to differentiate them from process hints. This
2299 * could be avoided by using a signal-specific knote list, but probably
2300 * isn't worth the trouble.
2301 */
2302static int
2303filt_signal(struct knote *kn, long hint)
2304{
984263bc
MD
2305 if (hint & NOTE_SIGNAL) {
2306 hint &= ~NOTE_SIGNAL;
2307
2308 if (kn->kn_id == hint)
2309 kn->kn_data++;
2310 }
2311 return (kn->kn_data != 0);
2312}