kernel - Major signal path adjustments to fix races, tsleep race fixes, +more
[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>
984263bc 54#include <sys/pioctl.h>
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55#include <sys/acct.h>
56#include <sys/fcntl.h>
167e6ecb 57#include <sys/lock.h>
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58#include <sys/wait.h>
59#include <sys/ktrace.h>
60#include <sys/syslog.h>
61#include <sys/stat.h>
62#include <sys/sysent.h>
63#include <sys/sysctl.h>
64#include <sys/malloc.h>
a7231bde 65#include <sys/interrupt.h>
984263bc 66#include <sys/unistd.h>
65957d54 67#include <sys/kern_syscall.h>
7c1212ec 68#include <sys/vkernel.h>
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69
70#include <sys/signal2.h>
e43a034f 71#include <sys/thread2.h>
94f98873 72#include <sys/spinlock2.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
4643740a 84static void lwp_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;
b1b4e5a6 259 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDSTOP)
984263bc 260 oact->sa_flags |= SA_NOCLDSTOP;
b1b4e5a6 261 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDWAIT)
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262 oact->sa_flags |= SA_NOCLDWAIT;
263 }
264 if (act) {
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265 /*
266 * Check for invalid requests. KILL and STOP cannot be
267 * caught.
268 */
269 if (sig == SIGKILL || sig == SIGSTOP) {
ac7ea585 270 if (act->sa_handler != SIG_DFL) {
5686ec5a 271 lwkt_reltoken(&p->p_token);
7c1212ec 272 return (EINVAL);
ac7ea585 273 }
7c1212ec 274 }
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275
276 /*
277 * Change setting atomically.
278 */
e43a034f 279 crit_enter();
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280
281 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
282 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
283 if (act->sa_flags & SA_SIGINFO) {
284 ps->ps_sigact[_SIG_IDX(sig)] =
285 (__sighandler_t *)act->sa_sigaction;
286 SIGADDSET(ps->ps_siginfo, sig);
287 } else {
288 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
289 SIGDELSET(ps->ps_siginfo, sig);
290 }
291 if (!(act->sa_flags & SA_RESTART))
292 SIGADDSET(ps->ps_sigintr, sig);
293 else
294 SIGDELSET(ps->ps_sigintr, sig);
295 if (act->sa_flags & SA_ONSTACK)
296 SIGADDSET(ps->ps_sigonstack, sig);
297 else
298 SIGDELSET(ps->ps_sigonstack, sig);
299 if (act->sa_flags & SA_RESETHAND)
300 SIGADDSET(ps->ps_sigreset, sig);
301 else
302 SIGDELSET(ps->ps_sigreset, sig);
303 if (act->sa_flags & SA_NODEFER)
304 SIGADDSET(ps->ps_signodefer, sig);
305 else
306 SIGDELSET(ps->ps_signodefer, sig);
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307 if (sig == SIGCHLD) {
308 if (act->sa_flags & SA_NOCLDSTOP)
b1b4e5a6 309 p->p_sigacts->ps_flag |= PS_NOCLDSTOP;
984263bc 310 else
b1b4e5a6 311 p->p_sigacts->ps_flag &= ~PS_NOCLDSTOP;
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312 if (act->sa_flags & SA_NOCLDWAIT) {
313 /*
314 * Paranoia: since SA_NOCLDWAIT is implemented
315 * by reparenting the dying child to PID 1 (and
316 * trust it to reap the zombie), PID 1 itself
317 * is forbidden to set SA_NOCLDWAIT.
318 */
319 if (p->p_pid == 1)
b1b4e5a6 320 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
984263bc 321 else
b1b4e5a6 322 p->p_sigacts->ps_flag |= PS_NOCLDWAIT;
8ebcad3f 323 } else {
b1b4e5a6 324 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
8ebcad3f 325 }
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326 }
327 /*
328 * Set bit in p_sigignore for signals that are set to SIG_IGN,
329 * and for signals set to SIG_DFL where the default is to
330 * ignore. However, don't put SIGCONT in p_sigignore, as we
331 * have to restart the process.
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332 *
333 * Also remove the signal from the process and lwp signal
334 * list.
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335 */
336 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
337 (sigprop(sig) & SA_IGNORE &&
338 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
984263bc 339 SIGDELSET(p->p_siglist, sig);
aa6c3de6 340 FOREACH_LWP_IN_PROC(lp, p) {
94f98873 341 spin_lock(&lp->lwp_spin);
aa6c3de6 342 SIGDELSET(lp->lwp_siglist, sig);
94f98873 343 spin_unlock(&lp->lwp_spin);
aa6c3de6 344 }
2883d2d8 345 if (sig != SIGCONT) {
84204577 346 /* easier in ksignal */
984263bc 347 SIGADDSET(p->p_sigignore, sig);
2883d2d8 348 }
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349 SIGDELSET(p->p_sigcatch, sig);
350 } else {
351 SIGDELSET(p->p_sigignore, sig);
352 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
353 SIGDELSET(p->p_sigcatch, sig);
354 else
355 SIGADDSET(p->p_sigcatch, sig);
356 }
984263bc 357
e43a034f 358 crit_exit();
984263bc 359 }
5686ec5a 360 lwkt_reltoken(&p->p_token);
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361 return (0);
362}
363
984263bc 364int
753fd850 365sys_sigaction(struct sigaction_args *uap)
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366{
367 struct sigaction act, oact;
1fd87d54 368 struct sigaction *actp, *oactp;
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369 int error;
370
371 actp = (uap->act != NULL) ? &act : NULL;
372 oactp = (uap->oact != NULL) ? &oact : NULL;
373 if (actp) {
374 error = copyin(uap->act, actp, sizeof(act));
375 if (error)
376 return (error);
377 }
65957d54 378 error = kern_sigaction(uap->sig, actp, oactp);
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379 if (oactp && !error) {
380 error = copyout(oactp, uap->oact, sizeof(oact));
381 }
382 return (error);
383}
384
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385/*
386 * Initialize signal state for process 0;
387 * set to ignore signals that are ignored by default.
388 */
389void
8ebcad3f 390siginit(struct proc *p)
984263bc 391{
1fd87d54 392 int i;
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393
394 for (i = 1; i <= NSIG; i++)
395 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
396 SIGADDSET(p->p_sigignore, i);
397}
398
399/*
400 * Reset signals for an exec of the specified process.
401 */
402void
8ebcad3f 403execsigs(struct proc *p)
984263bc 404{
1fd87d54 405 struct sigacts *ps = p->p_sigacts;
08f2f1bb 406 struct lwp *lp;
1fd87d54 407 int sig;
984263bc 408
aa6c3de6
SS
409 lp = ONLY_LWP_IN_PROC(p);
410
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411 /*
412 * Reset caught signals. Held signals remain held
413 * through p_sigmask (unless they were caught,
414 * and are now ignored by default).
415 */
416 while (SIGNOTEMPTY(p->p_sigcatch)) {
417 sig = sig_ffs(&p->p_sigcatch);
418 SIGDELSET(p->p_sigcatch, sig);
419 if (sigprop(sig) & SA_IGNORE) {
420 if (sig != SIGCONT)
421 SIGADDSET(p->p_sigignore, sig);
422 SIGDELSET(p->p_siglist, sig);
94f98873 423 /* don't need spinlock */
aa6c3de6 424 SIGDELSET(lp->lwp_siglist, sig);
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425 }
426 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
427 }
aa6c3de6 428
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429 /*
430 * Reset stack state to the user stack.
431 * Clear set of signals caught on the signal stack.
432 */
08f2f1bb
SS
433 lp->lwp_sigstk.ss_flags = SS_DISABLE;
434 lp->lwp_sigstk.ss_size = 0;
435 lp->lwp_sigstk.ss_sp = 0;
4643740a 436 lp->lwp_flags &= ~LWP_ALTSTACK;
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437 /*
438 * Reset no zombies if child dies flag as Solaris does.
439 */
b1b4e5a6 440 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
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441}
442
443/*
65957d54 444 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
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445 *
446 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
e43a034f 447 * p == curproc.
984263bc 448 */
65957d54
DRJ
449int
450kern_sigprocmask(int how, sigset_t *set, sigset_t *oset)
984263bc 451{
65957d54 452 struct thread *td = curthread;
08f2f1bb 453 struct lwp *lp = td->td_lwp;
5686ec5a 454 struct proc *p = td->td_proc;
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455 int error;
456
5686ec5a 457 lwkt_gettoken(&p->p_token);
ac7ea585 458
984263bc 459 if (oset != NULL)
08f2f1bb 460 *oset = lp->lwp_sigmask;
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461
462 error = 0;
463 if (set != NULL) {
464 switch (how) {
465 case SIG_BLOCK:
466 SIG_CANTMASK(*set);
08f2f1bb 467 SIGSETOR(lp->lwp_sigmask, *set);
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468 break;
469 case SIG_UNBLOCK:
08f2f1bb 470 SIGSETNAND(lp->lwp_sigmask, *set);
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471 break;
472 case SIG_SETMASK:
473 SIG_CANTMASK(*set);
08f2f1bb 474 lp->lwp_sigmask = *set;
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475 break;
476 default:
477 error = EINVAL;
478 break;
479 }
480 }
ac7ea585 481
5686ec5a 482 lwkt_reltoken(&p->p_token);
ac7ea585 483
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484 return (error);
485}
486
487/*
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488 * sigprocmask()
489 *
490 * MPSAFE
984263bc 491 */
984263bc 492int
753fd850 493sys_sigprocmask(struct sigprocmask_args *uap)
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494{
495 sigset_t set, oset;
496 sigset_t *setp, *osetp;
497 int error;
498
499 setp = (uap->set != NULL) ? &set : NULL;
500 osetp = (uap->oset != NULL) ? &oset : NULL;
501 if (setp) {
502 error = copyin(uap->set, setp, sizeof(set));
503 if (error)
504 return (error);
505 }
65957d54 506 error = kern_sigprocmask(uap->how, setp, osetp);
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507 if (osetp && !error) {
508 error = copyout(osetp, uap->oset, sizeof(oset));
509 }
510 return (error);
511}
512
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513/*
514 * MPSAFE
515 */
984263bc 516int
65957d54 517kern_sigpending(struct __sigset *set)
984263bc 518{
aa6c3de6 519 struct lwp *lp = curthread->td_lwp;
984263bc 520
aa6c3de6 521 *set = lwp_sigpend(lp);
984263bc 522
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523 return (0);
524}
525
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526/*
527 * MPSAFE
528 */
984263bc 529int
753fd850 530sys_sigpending(struct sigpending_args *uap)
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531{
532 sigset_t set;
65957d54 533 int error;
984263bc 534
65957d54 535 error = kern_sigpending(&set);
984263bc 536
65957d54
DRJ
537 if (error == 0)
538 error = copyout(&set, uap->set, sizeof(set));
539 return (error);
984263bc 540}
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541
542/*
543 * Suspend process until signal, providing mask to be set
65957d54 544 * in the meantime.
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545 *
546 * MPSAFE
984263bc 547 */
984263bc 548int
65957d54 549kern_sigsuspend(struct __sigset *set)
984263bc 550{
65957d54 551 struct thread *td = curthread;
08f2f1bb 552 struct lwp *lp = td->td_lwp;
65957d54 553 struct proc *p = td->td_proc;
41c20dac 554 struct sigacts *ps = p->p_sigacts;
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555
556 /*
557 * When returning from sigsuspend, we want
558 * the old mask to be restored after the
559 * signal handler has finished. Thus, we
560 * save it here and mark the sigacts structure
561 * to indicate this.
562 */
08f2f1bb 563 lp->lwp_oldsigmask = lp->lwp_sigmask;
4643740a 564 lp->lwp_flags |= LWP_OLDMASK;
984263bc 565
65957d54 566 SIG_CANTMASK(*set);
08f2f1bb 567 lp->lwp_sigmask = *set;
65957d54 568 while (tsleep(ps, PCATCH, "pause", 0) == 0)
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569 /* void */;
570 /* always return EINTR rather than ERESTART... */
571 return (EINTR);
572}
573
65957d54
DRJ
574/*
575 * Note nonstandard calling convention: libc stub passes mask, not
576 * pointer, to save a copyin.
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577 *
578 * MPSAFE
65957d54 579 */
984263bc 580int
753fd850 581sys_sigsuspend(struct sigsuspend_args *uap)
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582{
583 sigset_t mask;
65957d54 584 int error;
984263bc 585
65957d54
DRJ
586 error = copyin(uap->sigmask, &mask, sizeof(mask));
587 if (error)
588 return (error);
589
590 error = kern_sigsuspend(&mask);
591
592 return (error);
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593}
594
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595/*
596 * MPSAFE
597 */
984263bc 598int
65957d54 599kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss)
984263bc 600{
65957d54 601 struct thread *td = curthread;
08f2f1bb 602 struct lwp *lp = td->td_lwp;
65957d54 603 struct proc *p = td->td_proc;
984263bc 604
4643740a 605 if ((lp->lwp_flags & LWP_ALTSTACK) == 0)
08f2f1bb 606 lp->lwp_sigstk.ss_flags |= SS_DISABLE;
65957d54
DRJ
607
608 if (oss)
08f2f1bb 609 *oss = lp->lwp_sigstk;
65957d54
DRJ
610
611 if (ss) {
612 if (ss->ss_flags & SS_DISABLE) {
08f2f1bb 613 if (lp->lwp_sigstk.ss_flags & SS_ONSTACK)
65957d54 614 return (EINVAL);
4643740a 615 lp->lwp_flags &= ~LWP_ALTSTACK;
08f2f1bb 616 lp->lwp_sigstk.ss_flags = ss->ss_flags;
65957d54
DRJ
617 } else {
618 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
619 return (ENOMEM);
4643740a 620 lp->lwp_flags |= LWP_ALTSTACK;
08f2f1bb 621 lp->lwp_sigstk = *ss;
65957d54 622 }
984263bc 623 }
65957d54
DRJ
624
625 return (0);
984263bc 626}
984263bc 627
3919ced0
MD
628/*
629 * MPSAFE
630 */
984263bc 631int
753fd850 632sys_sigaltstack(struct sigaltstack_args *uap)
984263bc 633{
65957d54 634 stack_t ss, oss;
984263bc
MD
635 int error;
636
65957d54
DRJ
637 if (uap->ss) {
638 error = copyin(uap->ss, &ss, sizeof(ss));
639 if (error)
640 return (error);
984263bc 641 }
65957d54
DRJ
642
643 error = kern_sigaltstack(uap->ss ? &ss : NULL,
644 uap->oss ? &oss : NULL);
645
646 if (error == 0 && uap->oss)
647 error = copyout(&oss, uap->oss, sizeof(*uap->oss));
648 return (error);
984263bc
MD
649}
650
651/*
652 * Common code for kill process group/broadcast kill.
653 * cp is calling process.
654 */
8fa76237
MD
655struct killpg_info {
656 int nfound;
657 int sig;
658};
659
660static int killpg_all_callback(struct proc *p, void *data);
661
65957d54 662static int
552a98ac 663dokillpg(int sig, int pgid, int all)
984263bc 664{
8fa76237 665 struct killpg_info info;
41c20dac
MD
666 struct proc *cp = curproc;
667 struct proc *p;
984263bc 668 struct pgrp *pgrp;
8fa76237
MD
669
670 info.nfound = 0;
671 info.sig = sig;
984263bc 672
8ebcad3f 673 if (all) {
984263bc
MD
674 /*
675 * broadcast
676 */
8fa76237 677 allproc_scan(killpg_all_callback, &info);
8ebcad3f
MD
678 } else {
679 if (pgid == 0) {
984263bc
MD
680 /*
681 * zero pgid means send to my process group.
682 */
683 pgrp = cp->p_pgrp;
58c2553a 684 pgref(pgrp);
8ebcad3f 685 } else {
984263bc
MD
686 pgrp = pgfind(pgid);
687 if (pgrp == NULL)
688 return (ESRCH);
689 }
58c2553a
MD
690
691 /*
692 * Must interlock all signals against fork
693 */
167e6ecb 694 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
984263bc 695 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
f026f3b0 696 if (p->p_pid <= 1 ||
416d05d7 697 p->p_stat == SZOMB ||
4643740a 698 (p->p_flags & P_SYSTEM) ||
f026f3b0 699 !CANSIGNAL(p, sig)) {
984263bc 700 continue;
f026f3b0 701 }
8fa76237 702 ++info.nfound;
984263bc 703 if (sig)
84204577 704 ksignal(p, sig);
984263bc 705 }
167e6ecb 706 lockmgr(&pgrp->pg_lock, LK_RELEASE);
58c2553a 707 pgrel(pgrp);
984263bc 708 }
8fa76237
MD
709 return (info.nfound ? 0 : ESRCH);
710}
711
712static int
713killpg_all_callback(struct proc *p, void *data)
714{
715 struct killpg_info *info = data;
716
4643740a 717 if (p->p_pid <= 1 || (p->p_flags & P_SYSTEM) ||
8fa76237
MD
718 p == curproc || !CANSIGNAL(p, info->sig)) {
719 return (0);
720 }
721 ++info->nfound;
722 if (info->sig)
84204577 723 ksignal(p, info->sig);
8fa76237 724 return(0);
984263bc
MD
725}
726
73e40cb2
MD
727/*
728 * Send a general signal to a process or LWPs within that process. Note
729 * that new signals cannot be sent if a process is exiting.
ac7ea585
VS
730 *
731 * No requirements.
73e40cb2 732 */
984263bc 733int
f9366a82 734kern_kill(int sig, pid_t pid, lwpid_t tid)
984263bc 735{
ac7ea585
VS
736 int t;
737
65957d54 738 if ((u_int)sig > _SIG_MAXSIG)
984263bc 739 return (EINVAL);
ac7ea585
VS
740
741 lwkt_gettoken(&proc_token);
742
65957d54 743 if (pid > 0) {
505ba680 744 struct proc *p;
9e758ef5
SW
745 struct lwp *lp = NULL;
746
984263bc 747 /* kill single process */
ac7ea585
VS
748 if ((p = pfind(pid)) == NULL) {
749 lwkt_reltoken(&proc_token);
984263bc 750 return (ESRCH);
ac7ea585 751 }
5686ec5a 752 lwkt_gettoken(&p->p_token);
ac7ea585 753 if (!CANSIGNAL(p, sig)) {
5686ec5a
MD
754 lwkt_reltoken(&p->p_token);
755 PRELE(p);
ac7ea585 756 lwkt_reltoken(&proc_token);
984263bc 757 return (EPERM);
ac7ea585 758 }
73e40cb2
MD
759
760 /*
761 * NOP if the process is exiting. Note that lwpsignal() is
762 * called directly with P_WEXIT set to kill individual LWPs
763 * during exit, which is allowed.
764 */
4643740a 765 if (p->p_flags & P_WEXIT) {
5686ec5a
MD
766 lwkt_reltoken(&p->p_token);
767 PRELE(p);
ac7ea585 768 lwkt_reltoken(&proc_token);
73e40cb2 769 return (0);
ac7ea585 770 }
f9366a82 771 if (tid != -1) {
3e291793 772 lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, tid);
ac7ea585 773 if (lp == NULL) {
5686ec5a
MD
774 lwkt_reltoken(&p->p_token);
775 PRELE(p);
ac7ea585 776 lwkt_reltoken(&proc_token);
f9366a82 777 return (ESRCH);
ac7ea585 778 }
f9366a82 779 }
65957d54 780 if (sig)
f9366a82 781 lwpsignal(p, lp, sig);
5686ec5a
MD
782 lwkt_reltoken(&p->p_token);
783 PRELE(p);
ac7ea585 784 lwkt_reltoken(&proc_token);
984263bc
MD
785 return (0);
786 }
5686ec5a 787
f9366a82
SS
788 /*
789 * If we come here, pid is a special broadcast pid.
790 * This doesn't mix with a tid.
791 */
ac7ea585
VS
792 if (tid != -1) {
793 lwkt_reltoken(&proc_token);
f9366a82 794 return (EINVAL);
ac7ea585 795 }
65957d54 796 switch (pid) {
984263bc 797 case -1: /* broadcast signal */
ac7ea585
VS
798 t = (dokillpg(sig, 0, 1));
799 break;
984263bc 800 case 0: /* signal own process group */
ac7ea585
VS
801 t = (dokillpg(sig, 0, 0));
802 break;
984263bc 803 default: /* negative explicit process group */
ac7ea585
VS
804 t = (dokillpg(sig, -pid, 0));
805 break;
984263bc 806 }
ac7ea585
VS
807 lwkt_reltoken(&proc_token);
808 return t;
984263bc
MD
809}
810
984263bc 811int
753fd850 812sys_kill(struct kill_args *uap)
984263bc 813{
65957d54
DRJ
814 int error;
815
f9366a82
SS
816 error = kern_kill(uap->signum, uap->pid, -1);
817 return (error);
818}
819
820int
821sys_lwp_kill(struct lwp_kill_args *uap)
822{
823 int error;
824 pid_t pid = uap->pid;
825
826 /*
827 * A tid is mandatory for lwp_kill(), otherwise
828 * you could simply use kill().
829 */
830 if (uap->tid == -1)
831 return (EINVAL);
832
833 /*
834 * To save on a getpid() function call for intra-process
835 * signals, pid == -1 means current process.
836 */
837 if (pid == -1)
838 pid = curproc->p_pid;
65957d54 839
f9366a82 840 error = kern_kill(uap->signum, pid, uap->tid);
65957d54 841 return (error);
984263bc 842}
984263bc
MD
843
844/*
845 * Send a signal to a process group.
846 */
847void
41c20dac 848gsignal(int pgid, int sig)
984263bc
MD
849{
850 struct pgrp *pgrp;
851
852 if (pgid && (pgrp = pgfind(pgid)))
853 pgsignal(pgrp, sig, 0);
854}
855
856/*
857 * Send a signal to a process group. If checktty is 1,
858 * limit to members which have a controlling terminal.
167e6ecb
MD
859 *
860 * pg_lock interlocks against a fork that might be in progress, to
861 * ensure that the new child process picks up the signal.
984263bc
MD
862 */
863void
8ebcad3f 864pgsignal(struct pgrp *pgrp, int sig, int checkctty)
984263bc 865{
1fd87d54 866 struct proc *p;
984263bc 867
58c2553a
MD
868 /*
869 * Must interlock all signals against fork
870 */
167e6ecb 871 if (pgrp) {
58c2553a 872 pgref(pgrp);
167e6ecb
MD
873 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
874 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
4643740a 875 if (checkctty == 0 || p->p_flags & P_CONTROLT)
84204577 876 ksignal(p, sig);
167e6ecb
MD
877 }
878 lockmgr(&pgrp->pg_lock, LK_RELEASE);
58c2553a 879 pgrel(pgrp);
167e6ecb 880 }
984263bc
MD
881}
882
883/*
04d84fc2
MD
884 * Send a signal caused by a trap to the current lwp. If it will be caught
885 * immediately, deliver it with correct code. Otherwise, post it normally.
886 *
887 * These signals may ONLY be delivered to the specified lwp and may never
888 * be delivered to the process generically.
984263bc
MD
889 */
890void
08f2f1bb 891trapsignal(struct lwp *lp, int sig, u_long code)
984263bc 892{
08f2f1bb 893 struct proc *p = lp->lwp_proc;
dadab5e9 894 struct sigacts *ps = p->p_sigacts;
984263bc 895
7c1212ec
MD
896 /*
897 * If we are a virtual kernel running an emulated user process
898 * context, switch back to the virtual kernel context before
899 * trying to post the signal.
900 */
39005e16 901 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
287ebb09 902 struct trapframe *tf = lp->lwp_md.md_regs;
7c1212ec 903 tf->tf_trapno = 0;
287ebb09 904 vkernel_trap(lp, tf);
7c1212ec
MD
905 }
906
907
4643740a 908 if ((p->p_flags & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
08f2f1bb
SS
909 !SIGISMEMBER(lp->lwp_sigmask, sig)) {
910 lp->lwp_ru.ru_nsignals++;
984263bc 911#ifdef KTRACE
08f2f1bb 912 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
9fb04d14 913 ktrpsig(lp, sig, ps->ps_sigact[_SIG_IDX(sig)],
08f2f1bb 914 &lp->lwp_sigmask, code);
984263bc
MD
915#endif
916 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
08f2f1bb
SS
917 &lp->lwp_sigmask, code);
918 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
984263bc 919 if (!SIGISMEMBER(ps->ps_signodefer, sig))
08f2f1bb 920 SIGADDSET(lp->lwp_sigmask, sig);
984263bc
MD
921 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
922 /*
65957d54 923 * See kern_sigaction() for origin of this code.
984263bc
MD
924 */
925 SIGDELSET(p->p_sigcatch, sig);
926 if (sig != SIGCONT &&
927 sigprop(sig) & SA_IGNORE)
928 SIGADDSET(p->p_sigignore, sig);
929 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
930 }
931 } else {
7d20a8ff
SS
932 lp->lwp_code = code; /* XXX for core dump/debugger */
933 lp->lwp_sig = sig; /* XXX to verify code */
7278a846 934 lwpsignal(p, lp, sig);
984263bc
MD
935 }
936}
937
938/*
58c2553a
MD
939 * Find a suitable lwp to deliver the signal to. Returns NULL if all
940 * lwps hold the signal blocked.
1699b0b8 941 *
58c2553a 942 * Caller must hold p->p_token.
e2b148c6
MD
943 *
944 * Returns a lp or NULL. If non-NULL the lp is held and its token is
945 * acquired.
1699b0b8
SS
946 */
947static struct lwp *
948find_lwp_for_signal(struct proc *p, int sig)
949{
950 struct lwp *lp;
951 struct lwp *run, *sleep, *stop;
952
953 /*
954 * If the running/preempted thread belongs to the proc to which
955 * the signal is being delivered and this thread does not block
956 * the signal, then we can avoid a context switch by delivering
957 * the signal to this thread, because it will return to userland
958 * soon anyways.
959 */
960 lp = lwkt_preempted_proc();
e2b148c6
MD
961 if (lp != NULL && lp->lwp_proc == p) {
962 LWPHOLD(lp);
963 lwkt_gettoken(&lp->lwp_token);
964 if (!SIGISMEMBER(lp->lwp_sigmask, sig)) {
965 /* return w/ token held */
966 return (lp);
967 }
968 lwkt_reltoken(&lp->lwp_token);
969 LWPRELE(lp);
58c2553a 970 }
1699b0b8
SS
971
972 run = sleep = stop = NULL;
973 FOREACH_LWP_IN_PROC(lp, p) {
974 /*
975 * If the signal is being blocked by the lwp, then this
976 * lwp is not eligible for receiving the signal.
977 */
e2b148c6
MD
978 LWPHOLD(lp);
979 lwkt_gettoken(&lp->lwp_token);
980
981 if (SIGISMEMBER(lp->lwp_sigmask, sig)) {
982 lwkt_reltoken(&lp->lwp_token);
983 LWPRELE(lp);
1699b0b8 984 continue;
e2b148c6 985 }
1699b0b8
SS
986
987 switch (lp->lwp_stat) {
988 case LSRUN:
e2b148c6
MD
989 if (sleep) {
990 lwkt_token_swap();
991 lwkt_reltoken(&sleep->lwp_token);
992 LWPRELE(sleep);
993 sleep = NULL;
994 run = lp;
995 } else if (stop) {
996 lwkt_token_swap();
997 lwkt_reltoken(&stop->lwp_token);
998 LWPRELE(stop);
999 stop = NULL;
1000 run = lp;
1001 } else {
1002 run = lp;
1003 }
1699b0b8 1004 break;
1699b0b8 1005 case LSSLEEP:
4643740a 1006 if (lp->lwp_flags & LWP_SINTR) {
e2b148c6
MD
1007 if (sleep) {
1008 lwkt_reltoken(&lp->lwp_token);
1009 LWPRELE(lp);
1010 } else if (stop) {
1011 lwkt_token_swap();
1012 lwkt_reltoken(&stop->lwp_token);
1013 LWPRELE(stop);
1014 stop = NULL;
1015 sleep = lp;
1016 } else {
1017 sleep = lp;
1018 }
1019 } else {
1020 lwkt_reltoken(&lp->lwp_token);
1021 LWPRELE(lp);
1022 }
1023 break;
1024 case LSSTOP:
1025 if (sleep) {
1026 lwkt_reltoken(&lp->lwp_token);
1027 LWPRELE(lp);
1028 } else if (stop) {
1029 lwkt_reltoken(&lp->lwp_token);
1030 LWPRELE(lp);
1031 } else {
1032 stop = lp;
1033 }
1699b0b8
SS
1034 break;
1035 }
e2b148c6
MD
1036 if (run)
1037 break;
1699b0b8
SS
1038 }
1039
1040 if (run != NULL)
1041 return (run);
1042 else if (sleep != NULL)
1043 return (sleep);
1044 else
1045 return (stop);
1046}
1047
1048/*
984263bc
MD
1049 * Send the signal to the process. If the signal has an action, the action
1050 * is usually performed by the target process rather than the caller; we add
1051 * the signal to the set of pending signals for the process.
1052 *
1053 * Exceptions:
1054 * o When a stop signal is sent to a sleeping process that takes the
1055 * default action, the process is stopped without awakening it.
1056 * o SIGCONT restarts stopped processes (or puts them back to sleep)
1057 * regardless of the signal action (eg, blocked or ignored).
1058 *
1059 * Other ignored signals are discarded immediately.
ac7ea585 1060 *
8582ec21
MD
1061 * If the caller wishes to call this function from a hard code section the
1062 * caller must already hold p->p_token (see kern_clock.c).
1063 *
ac7ea585 1064 * No requirements.
984263bc
MD
1065 */
1066void
84204577 1067ksignal(struct proc *p, int sig)
984263bc 1068{
7278a846
SS
1069 lwpsignal(p, NULL, sig);
1070}
1071
1072/*
1073 * The core for ksignal. lp may be NULL, then a suitable thread
1074 * will be chosen. If not, lp MUST be a member of p.
ac7ea585 1075 *
8582ec21
MD
1076 * If the caller wishes to call this function from a hard code section the
1077 * caller must already hold p->p_token.
1078 *
ac7ea585 1079 * No requirements.
7278a846
SS
1080 */
1081void
1082lwpsignal(struct proc *p, struct lwp *lp, int sig)
1083{
8c986a82 1084 struct proc *q;
cb973d15 1085 sig_t action;
8c986a82 1086 int prop;
984263bc
MD
1087
1088 if (sig > _SIG_MAXSIG || sig <= 0) {
7278a846
SS
1089 kprintf("lwpsignal: signal %d\n", sig);
1090 panic("lwpsignal signal number");
984263bc
MD
1091 }
1092
7278a846
SS
1093 KKASSERT(lp == NULL || lp->lwp_proc == p);
1094
58c2553a 1095 PHOLD(p);
5686ec5a 1096 lwkt_gettoken(&p->p_token);
e2b148c6
MD
1097 if (lp) {
1098 LWPHOLD(lp);
1099 lwkt_gettoken(&lp->lwp_token);
1100 }
ac7ea585 1101
984263bc
MD
1102 prop = sigprop(sig);
1103
1104 /*
1105 * If proc is traced, always give parent a chance;
1106 * if signal event is tracked by procfs, give *that*
1107 * a chance, as well.
1108 */
4643740a 1109 if ((p->p_flags & P_TRACED) || (p->p_stops & S_SIG)) {
984263bc 1110 action = SIG_DFL;
8ebcad3f 1111 } else {
984263bc 1112 /*
73e40cb2
MD
1113 * Do not try to deliver signals to an exiting lwp. Note
1114 * that we must still deliver the signal if P_WEXIT is set
1115 * in the process flags.
984263bc 1116 */
4643740a 1117 if (lp && (lp->lwp_mpflags & LWP_MP_WEXIT)) {
e2b148c6
MD
1118 if (lp) {
1119 lwkt_reltoken(&lp->lwp_token);
1120 LWPRELE(lp);
1121 }
5686ec5a 1122 lwkt_reltoken(&p->p_token);
58c2553a 1123 PRELE(p);
e3161323 1124 return;
ac7ea585 1125 }
e3161323
MD
1126
1127 /*
8f433481 1128 * If the signal is being ignored, then we forget about
e3161323
MD
1129 * it immediately. NOTE: We don't set SIGCONT in p_sigignore,
1130 * and if it is set to SIG_IGN, action will be SIG_DFL here.
1131 */
ac7ea585 1132 if (SIGISMEMBER(p->p_sigignore, sig)) {
1ee5f2b8
SG
1133 /*
1134 * Even if a signal is set SIG_IGN, it may still be
1135 * lurking in a kqueue.
1136 */
1137 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
e2b148c6
MD
1138 if (lp) {
1139 lwkt_reltoken(&lp->lwp_token);
1140 LWPRELE(lp);
1141 }
5686ec5a 1142 lwkt_reltoken(&p->p_token);
58c2553a 1143 PRELE(p);
984263bc 1144 return;
ac7ea585 1145 }
1699b0b8 1146 if (SIGISMEMBER(p->p_sigcatch, sig))
984263bc
MD
1147 action = SIG_CATCH;
1148 else
1149 action = SIG_DFL;
1150 }
1151
344ad853
MD
1152 /*
1153 * If continuing, clear any pending STOP signals.
1154 */
984263bc
MD
1155 if (prop & SA_CONT)
1156 SIG_STOPSIGMASK(p->p_siglist);
9d63d5c0 1157
984263bc
MD
1158 if (prop & SA_STOP) {
1159 /*
1160 * If sending a tty stop signal to a member of an orphaned
1161 * process group, discard the signal here if the action
1162 * is default; don't stop the process below if sleeping,
1163 * and don't clear any pending SIGCONT.
1164 */
1165 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
8ebcad3f 1166 action == SIG_DFL) {
5686ec5a 1167 lwkt_reltoken(&p->p_token);
58c2553a 1168 PRELE(p);
984263bc 1169 return;
8ebcad3f 1170 }
984263bc 1171 SIG_CONTSIGMASK(p->p_siglist);
4643740a 1172 p->p_flags &= ~P_CONTINUED;
984263bc 1173 }
e43a034f
MD
1174
1175 crit_enter();
1176
1699b0b8 1177 if (p->p_stat == SSTOP) {
984263bc 1178 /*
04d84fc2
MD
1179 * Nobody can handle this signal, add it to the lwp or
1180 * process pending list
344ad853 1181 */
94f98873
MD
1182 if (lp) {
1183 spin_lock(&lp->lwp_spin);
04d84fc2 1184 SIGADDSET(lp->lwp_siglist, sig);
94f98873
MD
1185 spin_unlock(&lp->lwp_spin);
1186 } else {
04d84fc2 1187 SIGADDSET(p->p_siglist, sig);
94f98873 1188 }
344ad853 1189
344ad853
MD
1190 /*
1191 * If the process is stopped and is being traced, then no
1192 * further action is necessary.
984263bc 1193 */
4643740a 1194 if (p->p_flags & P_TRACED)
984263bc
MD
1195 goto out;
1196
1197 /*
344ad853
MD
1198 * If the process is stopped and receives a KILL signal,
1199 * make the process runnable.
984263bc 1200 */
9a379a4a
SS
1201 if (sig == SIGKILL) {
1202 proc_unstop(p);
7278a846 1203 goto active_process;
9a379a4a 1204 }
984263bc 1205
344ad853
MD
1206 /*
1207 * If the process is stopped and receives a CONT signal,
1208 * then try to make the process runnable again.
1209 */
984263bc
MD
1210 if (prop & SA_CONT) {
1211 /*
1212 * If SIGCONT is default (or ignored), we continue the
1213 * process but don't leave the signal in p_siglist, as
1214 * it has no further action. If SIGCONT is held, we
1215 * continue the process and leave the signal in
1216 * p_siglist. If the process catches SIGCONT, let it
344ad853 1217 * handle the signal itself.
8c986a82
MD
1218 *
1219 * XXX what if the signal is being held blocked?
1220 *
1221 * Token required to interlock kern_wait().
1222 * Reparenting can also cause a race so we have to
1223 * hold (q).
984263bc 1224 */
8c986a82
MD
1225 q = p->p_pptr;
1226 PHOLD(q);
1227 lwkt_gettoken(&q->p_token);
4643740a 1228 p->p_flags |= P_CONTINUED;
8c986a82 1229 wakeup(q);
984263bc
MD
1230 if (action == SIG_DFL)
1231 SIGDELSET(p->p_siglist, sig);
9a379a4a 1232 proc_unstop(p);
8c986a82
MD
1233 lwkt_reltoken(&q->p_token);
1234 PRELE(q);
984263bc 1235 if (action == SIG_CATCH)
1699b0b8 1236 goto active_process;
9a379a4a 1237 goto out;
344ad853
MD
1238 }
1239
1240 /*
1241 * If the process is stopped and receives another STOP
1242 * signal, we do not need to stop it again. If we did
1243 * the shell could get confused.
6ed57d3d
SS
1244 *
1245 * However, if the current/preempted lwp is part of the
1246 * process receiving the signal, we need to keep it,
1247 * so that this lwp can stop in issignal() later, as
1248 * we don't want to wait until it reaches userret!
344ad853
MD
1249 */
1250 if (prop & SA_STOP) {
7278a846
SS
1251 if (lwkt_preempted_proc() == NULL ||
1252 lwkt_preempted_proc()->lwp_proc != p)
6ed57d3d 1253 SIGDELSET(p->p_siglist, sig);
984263bc
MD
1254 }
1255
1256 /*
1699b0b8 1257 * Otherwise the process is stopped and it received some
4643740a
MD
1258 * signal, which does not change its stopped state. When
1259 * the process is continued a wakeup(p) will be issued which
1260 * will wakeup any threads sleeping in tstop().
984263bc 1261 */
e2b148c6
MD
1262 if (lp == NULL) {
1263 /* NOTE: returns lp w/ token held */
7278a846 1264 lp = find_lwp_for_signal(p, sig);
e2b148c6 1265 }
984263bc 1266 goto out;
1699b0b8
SS
1267
1268 /* NOTREACHED */
344ad853 1269 }
1699b0b8
SS
1270 /* else not stopped */
1271active_process:
1272
04d84fc2
MD
1273 /*
1274 * Never deliver a lwp-specific signal to a random lwp.
1275 */
1276 if (lp == NULL) {
e2b148c6 1277 /* NOTE: returns lp w/ token held */
7278a846 1278 lp = find_lwp_for_signal(p, sig);
e2b148c6
MD
1279 if (lp) {
1280 if (SIGISMEMBER(lp->lwp_sigmask, sig)) {
1281 lwkt_reltoken(&lp->lwp_token);
1282 LWPRELE(lp);
1283 lp = NULL;
1284 }
1285 }
04d84fc2 1286 }
344ad853
MD
1287
1288 /*
04d84fc2
MD
1289 * Deliver to the process generically if (1) the signal is being
1290 * sent to any thread or (2) we could not find a thread to deliver
1291 * it to.
344ad853 1292 */
04d84fc2 1293 if (lp == NULL) {
1699b0b8
SS
1294 SIGADDSET(p->p_siglist, sig);
1295 goto out;
1296 }
344ad853 1297
04d84fc2
MD
1298 /*
1299 * Deliver to a specific LWP whether it masks it or not. It will
1300 * not be dispatched if masked but we must still deliver it.
1301 */
1699b0b8 1302 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
4643740a 1303 (p->p_flags & P_TRACED) == 0) {
1699b0b8
SS
1304 p->p_nice = NZERO;
1305 }
344ad853 1306
1699b0b8
SS
1307 /*
1308 * If the process receives a STOP signal which indeed needs to
1309 * stop the process, do so. If the process chose to catch the
1310 * signal, it will be treated like any other signal.
1311 */
1312 if ((prop & SA_STOP) && action == SIG_DFL) {
1313 /*
1314 * If a child holding parent blocked, stopping
1315 * could cause deadlock. Take no action at this
1316 * time.
1317 */
4643740a 1318 if (p->p_flags & P_PPWAIT) {
1699b0b8
SS
1319 SIGADDSET(p->p_siglist, sig);
1320 goto out;
1321 }
1322
1323 /*
1324 * Do not actually try to manipulate the process, but simply
1325 * stop it. Lwps will stop as soon as they safely can.
1326 */
1327 p->p_xstat = sig;
f33e8653 1328 proc_stop(p);
1699b0b8 1329 goto out;
984263bc 1330 }
1699b0b8 1331
344ad853 1332 /*
1699b0b8 1333 * If it is a CONT signal with default action, just ignore it.
344ad853 1334 */
1699b0b8
SS
1335 if ((prop & SA_CONT) && action == SIG_DFL)
1336 goto out;
1337
1338 /*
1339 * Mark signal pending at this specific thread.
1340 */
94f98873 1341 spin_lock(&lp->lwp_spin);
1699b0b8 1342 SIGADDSET(lp->lwp_siglist, sig);
94f98873 1343 spin_unlock(&lp->lwp_spin);
1699b0b8 1344
7278a846
SS
1345 lwp_signotify(lp);
1346
1347out:
e2b148c6
MD
1348 if (lp) {
1349 lwkt_reltoken(&lp->lwp_token);
1350 LWPRELE(lp);
1351 }
5686ec5a 1352 lwkt_reltoken(&p->p_token);
58c2553a 1353 PRELE(p);
7278a846
SS
1354 crit_exit();
1355}
1356
98c2b8ac 1357/*
4643740a
MD
1358 * Notify the LWP that a signal has arrived. The LWP does not have to be
1359 * sleeping on the current cpu.
1360 *
1361 * p->p_token and lp->lwp_token must be held on call.
98c2b8ac
MD
1362 */
1363static void
7278a846
SS
1364lwp_signotify(struct lwp *lp)
1365{
5686ec5a 1366 ASSERT_LWKT_TOKEN_HELD(&lp->lwp_proc->p_token);
7278a846 1367 crit_enter();
98c2b8ac 1368
4643740a 1369 if (lp == lwkt_preempted_proc()) {
1699b0b8 1370 /*
4643740a
MD
1371 * lwp is on the current cpu AND it is currently running
1372 * (we preempted it).
1699b0b8 1373 */
4643740a
MD
1374 signotify();
1375 } else if (lp->lwp_thread->td_gd == mycpu) {
1699b0b8 1376 /*
4643740a
MD
1377 * lwp is on the current cpu, we can safely call
1378 * setrunnable()
1699b0b8 1379 */
4643740a
MD
1380 setrunnable(lp);
1381 } else
1382#ifdef SMP
1383 if (lp->lwp_flags & LWP_SINTR) {
1699b0b8 1384 /*
4643740a
MD
1385 * The lwp is on some other cpu but sitting in a tsleep,
1386 * we have to hold it to prevent it from going away and
1387 * chase after the cpu it is sitting on.
1699b0b8 1388 *
4643740a 1389 * The lwp_token interlocks LWP_SINTR.
1699b0b8 1390 */
4643740a
MD
1391 LWPHOLD(lp);
1392 lwkt_send_ipiq(lp->lwp_thread->td_gd, lwp_signotify_remote, lp);
1393 } else
1699b0b8 1394#endif
4643740a
MD
1395 {
1396 /*
1397 * Otherwise the lwp is either in some uninterruptable state
1398 * or it is on the userland scheduler's runqueue waiting to
1399 * be scheduled to a cpu.
1400 */
1699b0b8 1401 }
e43a034f 1402 crit_exit();
984263bc
MD
1403}
1404
cb973d15
MD
1405#ifdef SMP
1406
1407/*
4643740a
MD
1408 * This function is called via an IPI so we cannot call setrunnable() here
1409 * (because while we hold the lp we don't own its token, and can't get it
1410 * from an IPI).
d041353d 1411 *
4643740a
MD
1412 * We are interlocked by virtue of being on the same cpu as the target. If
1413 * we still are and LWP_SINTR is set we can schedule the target thread.
cb973d15
MD
1414 */
1415static void
4643740a 1416lwp_signotify_remote(void *arg)
cb973d15 1417{
553ea3c8 1418 struct lwp *lp = arg;
4643740a 1419 thread_t td = lp->lwp_thread;
60be1d11 1420
553ea3c8 1421 if (lp == lwkt_preempted_proc()) {
235957ed 1422 signotify();
4643740a
MD
1423 LWPRELE(lp);
1424 } else if (td->td_gd == mycpu) {
1425 if (lp->lwp_flags & LWP_SINTR)
1426 lwkt_schedule(td);
a22c590e 1427 if (td->td_flags & TDF_SINTR)
60be1d11 1428 lwkt_schedule(td);
4643740a
MD
1429 LWPRELE(lp);
1430 } else {
1431 lwkt_send_ipiq(td->td_gd, lwp_signotify_remote, lp);
1432 /* LWPHOLD() is forwarded to the target cpu */
60be1d11 1433 }
cb973d15
MD
1434}
1435
1436#endif
1437
98c2b8ac 1438/*
5686ec5a 1439 * Caller must hold p->p_token
98c2b8ac 1440 */
9a379a4a 1441void
f33e8653 1442proc_stop(struct proc *p)
9a379a4a 1443{
8c986a82 1444 struct proc *q;
f33e8653 1445 struct lwp *lp;
7278a846 1446
5686ec5a 1447 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
98c2b8ac
MD
1448 crit_enter();
1449
7278a846 1450 /* If somebody raced us, be happy with it */
98c2b8ac
MD
1451 if (p->p_stat == SSTOP || p->p_stat == SZOMB) {
1452 crit_exit();
7278a846 1453 return;
98c2b8ac 1454 }
9a379a4a 1455 p->p_stat = SSTOP;
7278a846 1456
7278a846 1457 FOREACH_LWP_IN_PROC(lp, p) {
e2b148c6
MD
1458 LWPHOLD(lp);
1459 lwkt_gettoken(&lp->lwp_token);
1460
7278a846
SS
1461 switch (lp->lwp_stat) {
1462 case LSSTOP:
1463 /*
1464 * Do nothing, we are already counted in
1465 * p_nstopped.
1466 */
1467 break;
1468
1469 case LSSLEEP:
1470 /*
1471 * We're sleeping, but we will stop before
1472 * returning to userspace, so count us
4643740a 1473 * as stopped as well. We set LWP_MP_WSTOP
f33e8653
SS
1474 * to signal the lwp that it should not
1475 * increase p_nstopped when reaching tstop().
4643740a
MD
1476 *
1477 * LWP_MP_WSTOP is protected by lp->lwp_token.
7278a846 1478 */
4643740a
MD
1479 if ((lp->lwp_mpflags & LWP_MP_WSTOP) == 0) {
1480 atomic_set_int(&lp->lwp_mpflags, LWP_MP_WSTOP);
f33e8653
SS
1481 ++p->p_nstopped;
1482 }
7278a846
SS
1483 break;
1484
1485 case LSRUN:
7278a846 1486 /*
f33e8653
SS
1487 * We might notify ourself, but that's not
1488 * a problem.
7278a846 1489 */
f33e8653 1490 lwp_signotify(lp);
7278a846
SS
1491 break;
1492 }
e2b148c6
MD
1493 lwkt_reltoken(&lp->lwp_token);
1494 LWPRELE(lp);
7278a846
SS
1495 }
1496
f33e8653 1497 if (p->p_nstopped == p->p_nthreads) {
8c986a82
MD
1498 /*
1499 * Token required to interlock kern_wait(). Reparenting can
1500 * also cause a race so we have to hold (q).
1501 */
1502 q = p->p_pptr;
1503 PHOLD(q);
1504 lwkt_gettoken(&q->p_token);
4643740a 1505 p->p_flags &= ~P_WAITED;
8c986a82
MD
1506 wakeup(q);
1507 if ((q->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
f33e8653 1508 ksignal(p->p_pptr, SIGCHLD);
8c986a82
MD
1509 lwkt_reltoken(&q->p_token);
1510 PRELE(q);
f33e8653
SS
1511 }
1512 crit_exit();
9a379a4a
SS
1513}
1514
98c2b8ac
MD
1515/*
1516 * Caller must hold proc_token
1517 */
9a379a4a
SS
1518void
1519proc_unstop(struct proc *p)
1520{
7278a846 1521 struct lwp *lp;
9a379a4a 1522
5686ec5a 1523 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
98c2b8ac
MD
1524 crit_enter();
1525
1526 if (p->p_stat != SSTOP) {
1527 crit_exit();
7278a846 1528 return;
98c2b8ac 1529 }
f33e8653 1530
9a379a4a 1531 p->p_stat = SACTIVE;
7278a846
SS
1532
1533 FOREACH_LWP_IN_PROC(lp, p) {
e2b148c6
MD
1534 LWPHOLD(lp);
1535 lwkt_gettoken(&lp->lwp_token);
1536
7278a846
SS
1537 switch (lp->lwp_stat) {
1538 case LSRUN:
1539 /*
1540 * Uh? Not stopped? Well, I guess that's okay.
1541 */
1542 if (bootverbose)
1543 kprintf("proc_unstop: lwp %d/%d not sleeping\n",
1544 p->p_pid, lp->lwp_tid);
1545 break;
1546
7278a846
SS
1547 case LSSLEEP:
1548 /*
1549 * Still sleeping. Don't bother waking it up.
f33e8653
SS
1550 * However, if this thread was counted as
1551 * stopped, undo this.
1552 *
1553 * Nevertheless we call setrunnable() so that it
1554 * will wake up in case a signal or timeout arrived
1555 * in the meantime.
4643740a
MD
1556 *
1557 * LWP_MP_WSTOP is protected by lp->lwp_token.
7278a846 1558 */
4643740a
MD
1559 if (lp->lwp_mpflags & LWP_MP_WSTOP) {
1560 atomic_clear_int(&lp->lwp_mpflags,
1561 LWP_MP_WSTOP);
f33e8653
SS
1562 --p->p_nstopped;
1563 } else {
1564 if (bootverbose)
1565 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n",
1566 p->p_pid, lp->lwp_tid);
1567 }
1568 /* FALLTHROUGH */
1569
1570 case LSSTOP:
4643740a
MD
1571 /*
1572 * This handles any lwp's waiting in a tsleep with
1573 * SIGCATCH.
1574 */
1575 lwp_signotify(lp);
7278a846 1576 break;
f33e8653 1577
7278a846 1578 }
e2b148c6
MD
1579 lwkt_reltoken(&lp->lwp_token);
1580 LWPRELE(lp);
7278a846 1581 }
4643740a
MD
1582
1583 /*
1584 * This handles any lwp's waiting in tstop(). We have interlocked
1585 * the setting of p_stat by acquiring and releasing each lpw's
1586 * token.
1587 */
1588 wakeup(p);
f33e8653 1589 crit_exit();
9a379a4a
SS
1590}
1591
ac7ea585
VS
1592/*
1593 * No requirements.
ac7ea585 1594 */
3a59f0f7
DX
1595static int
1596kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout)
1597{
1598 sigset_t savedmask, set;
1599 struct proc *p = curproc;
08f2f1bb 1600 struct lwp *lp = curthread->td_lwp;
3a59f0f7
DX
1601 int error, sig, hz, timevalid = 0;
1602 struct timespec rts, ets, ts;
1603 struct timeval tv;
1604
1605 error = 0;
1606 sig = 0;
c077b601
MD
1607 ets.tv_sec = 0; /* silence compiler warning */
1608 ets.tv_nsec = 0; /* silence compiler warning */
3a59f0f7 1609 SIG_CANTMASK(waitset);
08f2f1bb 1610 savedmask = lp->lwp_sigmask;
3a59f0f7
DX
1611
1612 if (timeout) {
f8c41806
DX
1613 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 &&
1614 timeout->tv_nsec < 1000000000) {
3a59f0f7
DX
1615 timevalid = 1;
1616 getnanouptime(&rts);
1617 ets = rts;
1618 timespecadd(&ets, timeout);
1619 }
1620 }
1621
1622 for (;;) {
aa6c3de6 1623 set = lwp_sigpend(lp);
3a59f0f7
DX
1624 SIGSETAND(set, waitset);
1625 if ((sig = sig_ffs(&set)) != 0) {
08f2f1bb
SS
1626 SIGFILLSET(lp->lwp_sigmask);
1627 SIGDELSET(lp->lwp_sigmask, sig);
1628 SIG_CANTMASK(lp->lwp_sigmask);
e473f776 1629 sig = issignal(lp, 1);
3a59f0f7
DX
1630 /*
1631 * It may be a STOP signal, in the case, issignal
1632 * returns 0, because we may stop there, and new
1633 * signal can come in, we should restart if we got
1634 * nothing.
1635 */
1636 if (sig == 0)
1637 continue;
1638 else
1639 break;
1640 }
1641
1642 /*
1643 * Previous checking got nothing, and we retried but still
1644 * got nothing, we should return the error status.
1645 */
1646 if (error)
1647 break;
1648
1649 /*
1650 * POSIX says this must be checked after looking for pending
1651 * signals.
1652 */
1653 if (timeout) {
c077b601 1654 if (timevalid == 0) {
3a59f0f7
DX
1655 error = EINVAL;
1656 break;
1657 }
1658 getnanouptime(&rts);
1659 if (timespeccmp(&rts, &ets, >=)) {
1660 error = EAGAIN;
1661 break;
1662 }
1663 ts = ets;
1664 timespecsub(&ts, &rts);
1665 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1666 hz = tvtohz_high(&tv);
5686ec5a 1667 } else {
3a59f0f7 1668 hz = 0;
5686ec5a 1669 }
3a59f0f7 1670
08f2f1bb
SS
1671 lp->lwp_sigmask = savedmask;
1672 SIGSETNAND(lp->lwp_sigmask, waitset);
b1b4e5a6
SS
1673 /*
1674 * We won't ever be woken up. Instead, our sleep will
1675 * be broken in lwpsignal().
1676 */
3a59f0f7
DX
1677 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz);
1678 if (timeout) {
1679 if (error == ERESTART) {
1680 /* can not restart a timeout wait. */
1681 error = EINTR;
1682 } else if (error == EAGAIN) {
1683 /* will calculate timeout by ourself. */
1684 error = 0;
1685 }
1686 }
1687 /* Retry ... */
1688 }
1689
08f2f1bb 1690 lp->lwp_sigmask = savedmask;
3a59f0f7
DX
1691 if (sig) {
1692 error = 0;
1693 bzero(info, sizeof(*info));
1694 info->si_signo = sig;
94f98873 1695 spin_lock(&lp->lwp_spin);
aa6c3de6 1696 lwp_delsig(lp, sig); /* take the signal! */
94f98873 1697 spin_unlock(&lp->lwp_spin);
1e1bd00b 1698
2883d2d8 1699 if (sig == SIGKILL) {
b276424c 1700 sigexit(lp, sig);
2883d2d8
MD
1701 /* NOT REACHED */
1702 }
3a59f0f7 1703 }
ac7ea585 1704
3a59f0f7
DX
1705 return (error);
1706}
1707
3919ced0
MD
1708/*
1709 * MPALMOSTSAFE
1710 */
3a59f0f7 1711int
753fd850 1712sys_sigtimedwait(struct sigtimedwait_args *uap)
3a59f0f7
DX
1713{
1714 struct timespec ts;
1715 struct timespec *timeout;
1716 sigset_t set;
1717 siginfo_t info;
1718 int error;
1719
1720 if (uap->timeout) {
1721 error = copyin(uap->timeout, &ts, sizeof(ts));
1722 if (error)
1723 return (error);
1724 timeout = &ts;
1725 } else {
1726 timeout = NULL;
1727 }
1728 error = copyin(uap->set, &set, sizeof(set));
1729 if (error)
1730 return (error);
1731 error = kern_sigtimedwait(set, &info, timeout);
1732 if (error)
1733 return (error);
1734 if (uap->info)
1735 error = copyout(&info, uap->info, sizeof(info));
1736 /* Repost if we got an error. */
7278a846
SS
1737 /*
1738 * XXX lwp
1739 *
1740 * This could transform a thread-specific signal to another
1741 * thread / process pending signal.
1742 */
3919ced0 1743 if (error) {
84204577 1744 ksignal(curproc, info.si_signo);
3919ced0 1745 } else {
3a59f0f7 1746 uap->sysmsg_result = info.si_signo;
3919ced0 1747 }
3a59f0f7
DX
1748 return (error);
1749}
1750
3919ced0
MD
1751/*
1752 * MPALMOSTSAFE
1753 */
3a59f0f7 1754int
753fd850 1755sys_sigwaitinfo(struct sigwaitinfo_args *uap)
3a59f0f7
DX
1756{
1757 siginfo_t info;
1758 sigset_t set;
1759 int error;
1760
1761 error = copyin(uap->set, &set, sizeof(set));
1762 if (error)
1763 return (error);
1764 error = kern_sigtimedwait(set, &info, NULL);
1765 if (error)
1766 return (error);
1767 if (uap->info)
1768 error = copyout(&info, uap->info, sizeof(info));
1769 /* Repost if we got an error. */
7278a846
SS
1770 /*
1771 * XXX lwp
1772 *
1773 * This could transform a thread-specific signal to another
1774 * thread / process pending signal.
1775 */
3919ced0 1776 if (error) {
84204577 1777 ksignal(curproc, info.si_signo);
3919ced0 1778 } else {
3a59f0f7 1779 uap->sysmsg_result = info.si_signo;
3919ced0 1780 }
3a59f0f7
DX
1781 return (error);
1782}
1783
984263bc 1784/*
a94976ad
MD
1785 * If the current process has received a signal that would interrupt a
1786 * system call, return EINTR or ERESTART as appropriate.
1787 */
1788int
08f2f1bb 1789iscaught(struct lwp *lp)
a94976ad 1790{
08f2f1bb 1791 struct proc *p = lp->lwp_proc;
a94976ad
MD
1792 int sig;
1793
1794 if (p) {
08f2f1bb 1795 if ((sig = CURSIG(lp)) != 0) {
a94976ad
MD
1796 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1797 return (EINTR);
1798 return (ERESTART);
1799 }
1800 }
1801 return(EWOULDBLOCK);
1802}
1803
1804/*
984263bc
MD
1805 * If the current process has received a signal (should be caught or cause
1806 * termination, should interrupt current syscall), return the signal number.
1807 * Stop signals with default action are processed immediately, then cleared;
1808 * they aren't returned. This is checked after each entry to the system for
1809 * a syscall or trap (though this can usually be done without calling issignal
5686ec5a 1810 * by checking the pending signal masks in the CURSIG macro).
984263bc 1811 *
5686ec5a
MD
1812 * This routine is called via CURSIG/__cursig. We will acquire and release
1813 * p->p_token but if the caller needs to interlock the test the caller must
1814 * also hold p->p_token.
bf189c26 1815 *
984263bc
MD
1816 * while (sig = CURSIG(curproc))
1817 * postsig(sig);
5686ec5a
MD
1818 *
1819 * MPSAFE
984263bc
MD
1820 */
1821int
e473f776 1822issignal(struct lwp *lp, int maytrace)
984263bc 1823{
08f2f1bb 1824 struct proc *p = lp->lwp_proc;
984263bc 1825 sigset_t mask;
1fd87d54 1826 int sig, prop;
984263bc 1827
5686ec5a 1828 lwkt_gettoken(&p->p_token);
98c2b8ac 1829
984263bc 1830 for (;;) {
4643740a 1831 int traced = (p->p_flags & P_TRACED) || (p->p_stops & S_SIG);
984263bc 1832
e473f776
SS
1833 /*
1834 * If this process is supposed to stop, stop this thread.
1835 */
1836 if (p->p_stat == SSTOP)
1837 tstop();
1838
aa6c3de6 1839 mask = lwp_sigpend(lp);
08f2f1bb 1840 SIGSETNAND(mask, lp->lwp_sigmask);
4643740a 1841 if (p->p_flags & P_PPWAIT)
984263bc 1842 SIG_STOPSIGMASK(mask);
1699b0b8 1843 if (SIGISEMPTY(mask)) { /* no signal to send */
5686ec5a 1844 lwkt_reltoken(&p->p_token);
984263bc 1845 return (0);
bf189c26 1846 }
984263bc
MD
1847 sig = sig_ffs(&mask);
1848
1849 STOPEVENT(p, S_SIG, sig);
1850
1851 /*
1852 * We should see pending but ignored signals
1853 * only if P_TRACED was on when they were posted.
1854 */
1855 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
94f98873 1856 spin_lock(&lp->lwp_spin);
aa6c3de6 1857 lwp_delsig(lp, sig);
94f98873 1858 spin_unlock(&lp->lwp_spin);
984263bc
MD
1859 continue;
1860 }
4643740a
MD
1861 if (maytrace &&
1862 (p->p_flags & P_TRACED) &&
1863 (p->p_flags & P_PPWAIT) == 0) {
984263bc 1864 /*
344ad853
MD
1865 * If traced, always stop, and stay stopped until
1866 * released by the parent.
1867 *
164b8401 1868 * NOTE: SSTOP may get cleared during the loop,
344ad853
MD
1869 * but we do not re-notify the parent if we have
1870 * to loop several times waiting for the parent
1871 * to let us continue.
164b8401
SS
1872 *
1873 * XXX not sure if this is still true
984263bc
MD
1874 */
1875 p->p_xstat = sig;
f33e8653 1876 proc_stop(p);
984263bc 1877 do {
9a379a4a 1878 tstop();
4643740a 1879 } while (!trace_req(p) && (p->p_flags & P_TRACED));
984263bc
MD
1880
1881 /*
1882 * If parent wants us to take the signal,
1883 * then it will leave it in p->p_xstat;
1884 * otherwise we just look for signals again.
1885 */
94f98873 1886 spin_lock(&lp->lwp_spin);
aa6c3de6 1887 lwp_delsig(lp, sig); /* clear old signal */
94f98873 1888 spin_unlock(&lp->lwp_spin);
984263bc
MD
1889 sig = p->p_xstat;
1890 if (sig == 0)
1891 continue;
1892
1893 /*
1894 * Put the new signal into p_siglist. If the
1895 * signal is being masked, look for other signals.
1699b0b8
SS
1896 *
1897 * XXX lwp might need a call to ksignal()
984263bc
MD
1898 */
1899 SIGADDSET(p->p_siglist, sig);
08f2f1bb 1900 if (SIGISMEMBER(lp->lwp_sigmask, sig))
984263bc
MD
1901 continue;
1902
1903 /*
1904 * If the traced bit got turned off, go back up
1905 * to the top to rescan signals. This ensures
1906 * that p_sig* and ps_sigact are consistent.
1907 */
4643740a 1908 if ((p->p_flags & P_TRACED) == 0)
984263bc
MD
1909 continue;
1910 }
1911
1912 prop = sigprop(sig);
1913
1914 /*
1915 * Decide whether the signal should be returned.
1916 * Return the signal's number, or fall through
1917 * to clear it from the pending mask.
1918 */
16094a36
MD
1919 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
1920 case (intptr_t)SIG_DFL:
984263bc
MD
1921 /*
1922 * Don't take default actions on system processes.
1923 */
1924 if (p->p_pid <= 1) {
1925#ifdef DIAGNOSTIC
1926 /*
1927 * Are you sure you want to ignore SIGSEGV
1928 * in init? XXX
1929 */
6ea70f76 1930 kprintf("Process (pid %lu) got signal %d\n",
984263bc
MD
1931 (u_long)p->p_pid, sig);
1932#endif
1933 break; /* == ignore */
1934 }
f758a39e
MD
1935
1936 /*
1937 * Handle the in-kernel checkpoint action
1938 */
1939 if (prop & SA_CKPT) {
7d20a8ff 1940 checkpoint_signal_handler(lp);
f758a39e
MD
1941 break;
1942 }
1943
984263bc
MD
1944 /*
1945 * If there is a pending stop signal to process
1946 * with default action, stop here,
1947 * then clear the signal. However,
1948 * if process is member of an orphaned
1949 * process group, ignore tty stop signals.
1950 */
1951 if (prop & SA_STOP) {
4643740a 1952 if (p->p_flags & P_TRACED ||
984263bc
MD
1953 (p->p_pgrp->pg_jobc == 0 &&
1954 prop & SA_TTYSTOP))
1955 break; /* == ignore */
680b21e7 1956 p->p_xstat = sig;
f33e8653 1957 proc_stop(p);
e473f776 1958 tstop();
984263bc
MD
1959 break;
1960 } else if (prop & SA_IGNORE) {
1961 /*
1962 * Except for SIGCONT, shouldn't get here.
1963 * Default action is to ignore; drop it.
1964 */
1965 break; /* == ignore */
8ebcad3f 1966 } else {
5686ec5a 1967 lwkt_reltoken(&p->p_token);
984263bc 1968 return (sig);
8ebcad3f
MD
1969 }
1970
984263bc
MD
1971 /*NOTREACHED*/
1972
16094a36 1973 case (intptr_t)SIG_IGN:
984263bc
MD
1974 /*
1975 * Masking above should prevent us ever trying
1976 * to take action on an ignored signal other
1977 * than SIGCONT, unless process is traced.
1978 */
1979 if ((prop & SA_CONT) == 0 &&
4643740a 1980 (p->p_flags & P_TRACED) == 0)
6ea70f76 1981 kprintf("issignal\n");
984263bc
MD
1982 break; /* == ignore */
1983
1984 default:
1985 /*
1986 * This signal has an action, let
1987 * postsig() process it.
1988 */
5686ec5a 1989 lwkt_reltoken(&p->p_token);
984263bc
MD
1990 return (sig);
1991 }
94f98873 1992 spin_lock(&lp->lwp_spin);
aa6c3de6 1993 lwp_delsig(lp, sig); /* take the signal! */
94f98873 1994 spin_unlock(&lp->lwp_spin);
984263bc
MD
1995 }
1996 /* NOTREACHED */
1997}
1998
1999/*
984263bc
MD
2000 * Take the action for the specified signal
2001 * from the current set of pending signals.
fc509460
MD
2002 *
2003 * Caller must hold p->p_token
984263bc
MD
2004 */
2005void
8ebcad3f 2006postsig(int sig)
984263bc 2007{
08f2f1bb
SS
2008 struct lwp *lp = curthread->td_lwp;
2009 struct proc *p = lp->lwp_proc;
984263bc
MD
2010 struct sigacts *ps = p->p_sigacts;
2011 sig_t action;
2012 sigset_t returnmask;
2013 int code;
2014
2015 KASSERT(sig != 0, ("postsig"));
2016
6ac7d3ce
SG
2017 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
2018
7c1212ec
MD
2019 /*
2020 * If we are a virtual kernel running an emulated user process
2021 * context, switch back to the virtual kernel context before
2022 * trying to post the signal.
2023 */
39005e16 2024 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
287ebb09 2025 struct trapframe *tf = lp->lwp_md.md_regs;
7c1212ec 2026 tf->tf_trapno = 0;
287ebb09 2027 vkernel_trap(lp, tf);
7c1212ec
MD
2028 }
2029
94f98873 2030 spin_lock(&lp->lwp_spin);
aa6c3de6 2031 lwp_delsig(lp, sig);
94f98873 2032 spin_unlock(&lp->lwp_spin);
984263bc
MD
2033 action = ps->ps_sigact[_SIG_IDX(sig)];
2034#ifdef KTRACE
08f2f1bb 2035 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
4643740a 2036 ktrpsig(lp, sig, action, lp->lwp_flags & LWP_OLDMASK ?
08f2f1bb 2037 &lp->lwp_oldsigmask : &lp->lwp_sigmask, 0);
984263bc
MD
2038#endif
2039 STOPEVENT(p, S_SIG, sig);
2040
2041 if (action == SIG_DFL) {
2042 /*
2043 * Default action, where the default is to kill
2044 * the process. (Other cases were ignored above.)
2045 */
b276424c 2046 sigexit(lp, sig);
984263bc
MD
2047 /* NOTREACHED */
2048 } else {
2049 /*
2050 * If we get here, the signal must be caught.
2051 */
08f2f1bb 2052 KASSERT(action != SIG_IGN && !SIGISMEMBER(lp->lwp_sigmask, sig),
984263bc 2053 ("postsig action"));
7c1212ec
MD
2054
2055 crit_enter();
2056
2057 /*
2058 * Reset the signal handler if asked to
2059 */
2060 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
2061 /*
2062 * See kern_sigaction() for origin of this code.
2063 */
2064 SIGDELSET(p->p_sigcatch, sig);
2065 if (sig != SIGCONT &&
2066 sigprop(sig) & SA_IGNORE)
2067 SIGADDSET(p->p_sigignore, sig);
2068 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
2069 }
2070
2071 /*
7c1212ec
MD
2072 * Set the signal mask and calculate the mask to restore
2073 * when the signal function returns.
984263bc
MD
2074 *
2075 * Special case: user has done a sigsuspend. Here the
2076 * current mask is not of interest, but rather the
2077 * mask from before the sigsuspend is what we want
2078 * restored after the signal processing is completed.
2079 */
4643740a 2080 if (lp->lwp_flags & LWP_OLDMASK) {
08f2f1bb 2081 returnmask = lp->lwp_oldsigmask;
4643740a 2082 lp->lwp_flags &= ~LWP_OLDMASK;
8ebcad3f 2083 } else {
08f2f1bb 2084 returnmask = lp->lwp_sigmask;
8ebcad3f 2085 }
08f2f1bb
SS
2086
2087 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
984263bc 2088 if (!SIGISMEMBER(ps->ps_signodefer, sig))
08f2f1bb 2089 SIGADDSET(lp->lwp_sigmask, sig);
984263bc 2090
e43a034f 2091 crit_exit();
08f2f1bb 2092 lp->lwp_ru.ru_nsignals++;
7d20a8ff 2093 if (lp->lwp_sig != sig) {
984263bc
MD
2094 code = 0;
2095 } else {
7d20a8ff
SS
2096 code = lp->lwp_code;
2097 lp->lwp_code = 0;
2098 lp->lwp_sig = 0;
984263bc
MD
2099 }
2100 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
2101 }
2102}
2103
2104/*
2105 * Kill the current process for stated reason.
2106 */
2107void
8ebcad3f 2108killproc(struct proc *p, char *why)
984263bc 2109{
7c1212ec
MD
2110 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n",
2111 p->p_pid, p->p_comm,
41c20dac 2112 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
84204577 2113 ksignal(p, SIGKILL);
984263bc
MD
2114}
2115
2116/*
2117 * Force the current process to exit with the specified signal, dumping core
2118 * if appropriate. We bypass the normal tests for masked and caught signals,
2119 * allowing unrecoverable failures to terminate the process without changing
2120 * signal state. Mark the accounting record with the signal termination.
2121 * If dumping core, save the signal number for the debugger. Calls exit and
2122 * does not return.
2883d2d8
MD
2123 *
2124 * This routine does not return.
984263bc
MD
2125 */
2126void
b276424c 2127sigexit(struct lwp *lp, int sig)
984263bc 2128{
b276424c 2129 struct proc *p = lp->lwp_proc;
7d20a8ff 2130
b5c4d81f 2131 lwkt_gettoken(&p->p_token);
984263bc
MD
2132 p->p_acflag |= AXSIG;
2133 if (sigprop(sig) & SA_CORE) {
7d20a8ff 2134 lp->lwp_sig = sig;
984263bc
MD
2135 /*
2136 * Log signals which would cause core dumps
2137 * (Log as LOG_INFO to appease those who don't want
2138 * these messages.)
2139 * XXX : Todo, as well as euid, write out ruid too
2140 */
7d20a8ff 2141 if (coredump(lp, sig) == 0)
984263bc
MD
2142 sig |= WCOREFLAG;
2143 if (kern_logsigexit)
2144 log(LOG_INFO,
2145 "pid %d (%s), uid %d: exited on signal %d%s\n",
2146 p->p_pid, p->p_comm,
41c20dac 2147 p->p_ucred ? p->p_ucred->cr_uid : -1,
984263bc
MD
2148 sig &~ WCOREFLAG,
2149 sig & WCOREFLAG ? " (core dumped)" : "");
2150 }
b5c4d81f 2151 lwkt_reltoken(&p->p_token);
41c20dac 2152 exit1(W_EXITCODE(0, sig));
984263bc
MD
2153 /* NOTREACHED */
2154}
2155
2156static char corefilename[MAXPATHLEN+1] = {"%N.core"};
2157SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
2158 sizeof(corefilename), "process corefile name format string");
2159
2160/*
2161 * expand_name(name, uid, pid)
2162 * Expand the name described in corefilename, using name, uid, and pid.
6ea70f76 2163 * corefilename is a kprintf-like string, with three format specifiers:
984263bc
MD
2164 * %N name of process ("name")
2165 * %P process id (pid)
2166 * %U user id (uid)
2167 * For example, "%N.core" is the default; they can be disabled completely
2168 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
2169 * This is controlled by the sysctl variable kern.corefile (see above).
2170 */
2171
2172static char *
8ebcad3f
MD
2173expand_name(const char *name, uid_t uid, pid_t pid)
2174{
984263bc
MD
2175 char *temp;
2176 char buf[11]; /* Buffer for pid/uid -- max 4B */
2177 int i, n;
2178 char *format = corefilename;
2179 size_t namelen;
2180
efda3bd0 2181 temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
984263bc
MD
2182 if (temp == NULL)
2183 return NULL;
2184 namelen = strlen(name);
2185 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
2186 int l;
2187 switch (format[i]) {
2188 case '%': /* Format character */
2189 i++;
2190 switch (format[i]) {
2191 case '%':
2192 temp[n++] = '%';
2193 break;
2194 case 'N': /* process name */
2195 if ((n + namelen) > MAXPATHLEN) {
2196 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2197 pid, name, uid, temp, name);
efda3bd0 2198 kfree(temp, M_TEMP);
984263bc
MD
2199 return NULL;
2200 }
2201 memcpy(temp+n, name, namelen);
2202 n += namelen;
2203 break;
2204 case 'P': /* process id */
f8c7a42d 2205 l = ksprintf(buf, "%u", pid);
984263bc
MD
2206 if ((n + l) > MAXPATHLEN) {
2207 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2208 pid, name, uid, temp, name);
efda3bd0 2209 kfree(temp, M_TEMP);
984263bc
MD
2210 return NULL;
2211 }
2212 memcpy(temp+n, buf, l);
2213 n += l;
2214 break;
2215 case 'U': /* user id */
f8c7a42d 2216 l = ksprintf(buf, "%u", uid);
984263bc
MD
2217 if ((n + l) > MAXPATHLEN) {
2218 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2219 pid, name, uid, temp, name);
efda3bd0 2220 kfree(temp, M_TEMP);
984263bc
MD
2221 return NULL;
2222 }
2223 memcpy(temp+n, buf, l);
2224 n += l;
2225 break;
2226 default:
2227 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
2228 }
2229 break;
2230 default:
2231 temp[n++] = format[i];
2232 }
2233 }
2234 temp[n] = '\0';
2235 return temp;
2236}
2237
2238/*
2239 * Dump a process' core. The main routine does some
2240 * policy checking, and creates the name of the coredump;
2241 * then it passes on a vnode and a size limit to the process-specific
2242 * coredump routine if there is one; if there _is not_ one, it returns
2243 * ENOSYS; otherwise it returns the error from the process-specific routine.
7d20a8ff
SS
2244 *
2245 * The parameter `lp' is the lwp which triggered the coredump.
984263bc
MD
2246 */
2247
2248static int
7d20a8ff 2249coredump(struct lwp *lp, int sig)
984263bc 2250{
7d20a8ff 2251 struct proc *p = lp->lwp_proc;
dadab5e9
MD
2252 struct vnode *vp;
2253 struct ucred *cred = p->p_ucred;
984263bc 2254 struct flock lf;
fad57d0e 2255 struct nlookupdata nd;
984263bc
MD
2256 struct vattr vattr;
2257 int error, error1;
2258 char *name; /* name of corefile */
2259 off_t limit;
2260
2261 STOPEVENT(p, S_CORE, 0);
2262
4643740a 2263 if (((sugid_coredump == 0) && p->p_flags & P_SUGID) || do_coredump == 0)
984263bc
MD
2264 return (EFAULT);
2265
2266 /*
2267 * Note that the bulk of limit checking is done after
2268 * the corefile is created. The exception is if the limit
2269 * for corefiles is 0, in which case we don't bother
2270 * creating the corefile at all. This layout means that
2271 * a corefile is truncated instead of not being created,
2272 * if it is larger than the limit.
2273 */
2274 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
2275 if (limit == 0)
50fd5388 2276 return EFBIG;
984263bc
MD
2277
2278 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
2279 if (name == NULL)
2280 return (EINVAL);
fad57d0e
MD
2281 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
2282 if (error == 0)
2283 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
efda3bd0 2284 kfree(name, M_TEMP);
fad57d0e
MD
2285 if (error) {
2286 nlookup_done(&nd);
984263bc 2287 return (error);
fad57d0e
MD
2288 }
2289 vp = nd.nl_open_vp;
2290 nd.nl_open_vp = NULL;
2291 nlookup_done(&nd);
984263bc 2292
a11aaa81 2293 vn_unlock(vp);
984263bc
MD
2294 lf.l_whence = SEEK_SET;
2295 lf.l_start = 0;
2296 lf.l_len = 0;
2297 lf.l_type = F_WRLCK;
71c18fe3 2298 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0);
984263bc
MD
2299 if (error)
2300 goto out2;
2301
2302 /* Don't dump to non-regular files or files with links. */
2303 if (vp->v_type != VREG ||
87de5057 2304 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) {
984263bc
MD
2305 error = EFAULT;
2306 goto out1;
2307 }
2308
9d2a4e5d
MD
2309 /* Don't dump to files current user does not own */
2310 if (vattr.va_uid != p->p_ucred->cr_uid) {
2311 error = EFAULT;
2312 goto out1;
2313 }
2314
984263bc 2315 VATTR_NULL(&vattr);
ca466bae 2316 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
984263bc 2317 vattr.va_size = 0;
87de5057 2318 VOP_SETATTR(vp, &vattr, cred);
984263bc 2319 p->p_acflag |= ACORE;
a11aaa81 2320 vn_unlock(vp);
984263bc
MD
2321
2322 error = p->p_sysent->sv_coredump ?
7d20a8ff 2323 p->p_sysent->sv_coredump(lp, sig, vp, limit) : ENOSYS;
984263bc
MD
2324
2325out1:
2326 lf.l_type = F_UNLCK;
71c18fe3 2327 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0);
984263bc 2328out2:
87de5057 2329 error1 = vn_close(vp, FWRITE);
984263bc
MD
2330 if (error == 0)
2331 error = error1;
2332 return (error);
2333}
2334
2335/*
2336 * Nonexistent system call-- signal process (may want to handle it).
2337 * Flag error in case process won't see signal immediately (blocked or ignored).
3919ced0
MD
2338 *
2339 * MPALMOSTSAFE
984263bc 2340 */
984263bc
MD
2341/* ARGSUSED */
2342int
753fd850 2343sys_nosys(struct nosys_args *args)
984263bc 2344{
7278a846 2345 lwpsignal(curproc, curthread->td_lwp, SIGSYS);
984263bc
MD
2346 return (EINVAL);
2347}
2348
2349/*
2350 * Send a SIGIO or SIGURG signal to a process or process group using
2351 * stored credentials rather than those of the current process.
2352 */
2353void
dadab5e9 2354pgsigio(struct sigio *sigio, int sig, int checkctty)
984263bc
MD
2355{
2356 if (sigio == NULL)
2357 return;
2358
2359 if (sigio->sio_pgid > 0) {
2360 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
2361 sigio->sio_proc))
84204577 2362 ksignal(sigio->sio_proc, sig);
984263bc
MD
2363 } else if (sigio->sio_pgid < 0) {
2364 struct proc *p;
58c2553a 2365 struct pgrp *pg = sigio->sio_pgrp;
984263bc 2366
58c2553a
MD
2367 /*
2368 * Must interlock all signals against fork
2369 */
2370 pgref(pg);
2371 lockmgr(&pg->pg_lock, LK_EXCLUSIVE);
2372 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
984263bc 2373 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
4643740a 2374 (checkctty == 0 || (p->p_flags & P_CONTROLT)))
84204577 2375 ksignal(p, sig);
167e6ecb 2376 }
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2377 lockmgr(&pg->pg_lock, LK_RELEASE);
2378 pgrel(pg);
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2379 }
2380}
2381
2382static int
2383filt_sigattach(struct knote *kn)
2384{
2385 struct proc *p = curproc;
2386
2387 kn->kn_ptr.p_proc = p;
2388 kn->kn_flags |= EV_CLEAR; /* automatically set */
2389
2390 /* XXX lock the proc here while adding to the list? */
5b22f1a7 2391 knote_insert(&p->p_klist, kn);
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2392
2393 return (0);
2394}
2395
2396static void
2397filt_sigdetach(struct knote *kn)
2398{
2399 struct proc *p = kn->kn_ptr.p_proc;
2400
5b22f1a7 2401 knote_remove(&p->p_klist, kn);
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2402}
2403
2404/*
2405 * signal knotes are shared with proc knotes, so we apply a mask to
2406 * the hint in order to differentiate them from process hints. This
2407 * could be avoided by using a signal-specific knote list, but probably
2408 * isn't worth the trouble.
2409 */
2410static int
2411filt_signal(struct knote *kn, long hint)
2412{
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2413 if (hint & NOTE_SIGNAL) {
2414 hint &= ~NOTE_SIGNAL;
2415
2416 if (kn->kn_id == hint)
2417 kn->kn_data++;
2418 }
2419 return (kn->kn_data != 0);
2420}