Fix a bug introduced earlier. We can't put packets back into
[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 $
0ba6fbbf 40 * $DragonFly: src/sys/kern/kern_sig.c,v 1.33 2004/11/23 06:32:32 dillon Exp $
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41 */
42
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43#include "opt_ktrace.h"
44
45#include <sys/param.h>
dadab5e9 46#include <sys/systm.h>
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47#include <sys/kernel.h>
48#include <sys/sysproto.h>
49#include <sys/signalvar.h>
50#include <sys/resourcevar.h>
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51#include <sys/vnode.h>
52#include <sys/event.h>
53#include <sys/proc.h>
fad57d0e 54#include <sys/nlookup.h>
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55#include <sys/pioctl.h>
56#include <sys/systm.h>
57#include <sys/acct.h>
58#include <sys/fcntl.h>
59#include <sys/wait.h>
60#include <sys/ktrace.h>
61#include <sys/syslog.h>
62#include <sys/stat.h>
63#include <sys/sysent.h>
64#include <sys/sysctl.h>
65#include <sys/malloc.h>
66#include <sys/unistd.h>
65957d54 67#include <sys/kern_syscall.h>
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68
69
70#include <machine/ipl.h>
71#include <machine/cpu.h>
72#include <machine/smp.h>
73
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74static int coredump(struct proc *);
75static char *expand_name(const char *, uid_t, pid_t);
76static int killpg(int sig, int pgid, int all);
77static int sig_ffs(sigset_t *set);
78static int sigprop(int sig);
79static void stop(struct proc *);
cb973d15 80#ifdef SMP
8ebcad3f 81static void signotify_remote(void *arg);
cb973d15 82#endif
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83
84static int filt_sigattach(struct knote *kn);
85static void filt_sigdetach(struct knote *kn);
86static int filt_signal(struct knote *kn, long hint);
87
88struct filterops sig_filtops =
89 { 0, filt_sigattach, filt_sigdetach, filt_signal };
90
91static int kern_logsigexit = 1;
92SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
93 &kern_logsigexit, 0,
94 "Log processes quitting on abnormal signals to syslog(3)");
95
96/*
97 * Can process p, with pcred pc, send the signal sig to process q?
98 */
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99#define CANSIGNAL(q, sig) \
100 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \
101 ((sig) == SIGCONT && (q)->p_session == curproc->p_session))
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102
103/*
104 * Policy -- Can real uid ruid with ucred uc send a signal to process q?
105 */
106#define CANSIGIO(ruid, uc, q) \
107 ((uc)->cr_uid == 0 || \
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108 (ruid) == (q)->p_ucred->cr_ruid || \
109 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \
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110 (ruid) == (q)->p_ucred->cr_uid || \
111 (uc)->cr_uid == (q)->p_ucred->cr_uid)
112
113int sugid_coredump;
114SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
8ebcad3f 115 &sugid_coredump, 0, "Enable coredumping set user/group ID processes");
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116
117static int do_coredump = 1;
118SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
119 &do_coredump, 0, "Enable/Disable coredumps");
120
121/*
122 * Signal properties and actions.
123 * The array below categorizes the signals and their default actions
124 * according to the following properties:
125 */
126#define SA_KILL 0x01 /* terminates process by default */
127#define SA_CORE 0x02 /* ditto and coredumps */
128#define SA_STOP 0x04 /* suspend process */
129#define SA_TTYSTOP 0x08 /* ditto, from tty */
130#define SA_IGNORE 0x10 /* ignore by default */
131#define SA_CONT 0x20 /* continue if suspended */
132#define SA_CANTMASK 0x40 /* non-maskable, catchable */
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133#define SA_CKPT 0x80 /* checkpoint process */
134
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135
136static int sigproptbl[NSIG] = {
137 SA_KILL, /* SIGHUP */
138 SA_KILL, /* SIGINT */
139 SA_KILL|SA_CORE, /* SIGQUIT */
140 SA_KILL|SA_CORE, /* SIGILL */
141 SA_KILL|SA_CORE, /* SIGTRAP */
142 SA_KILL|SA_CORE, /* SIGABRT */
143 SA_KILL|SA_CORE, /* SIGEMT */
144 SA_KILL|SA_CORE, /* SIGFPE */
145 SA_KILL, /* SIGKILL */
146 SA_KILL|SA_CORE, /* SIGBUS */
147 SA_KILL|SA_CORE, /* SIGSEGV */
148 SA_KILL|SA_CORE, /* SIGSYS */
149 SA_KILL, /* SIGPIPE */
150 SA_KILL, /* SIGALRM */
151 SA_KILL, /* SIGTERM */
152 SA_IGNORE, /* SIGURG */
153 SA_STOP, /* SIGSTOP */
154 SA_STOP|SA_TTYSTOP, /* SIGTSTP */
155 SA_IGNORE|SA_CONT, /* SIGCONT */
156 SA_IGNORE, /* SIGCHLD */
157 SA_STOP|SA_TTYSTOP, /* SIGTTIN */
158 SA_STOP|SA_TTYSTOP, /* SIGTTOU */
159 SA_IGNORE, /* SIGIO */
160 SA_KILL, /* SIGXCPU */
161 SA_KILL, /* SIGXFSZ */
162 SA_KILL, /* SIGVTALRM */
163 SA_KILL, /* SIGPROF */
164 SA_IGNORE, /* SIGWINCH */
165 SA_IGNORE, /* SIGINFO */
166 SA_KILL, /* SIGUSR1 */
167 SA_KILL, /* SIGUSR2 */
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168 SA_IGNORE, /* SIGTHR */
169 SA_CKPT, /* SIGCKPT */
170 SA_KILL|SA_CKPT, /* SIGCKPTEXIT */
171 SA_IGNORE,
172 SA_IGNORE,
173 SA_IGNORE,
174 SA_IGNORE,
175 SA_IGNORE,
176 SA_IGNORE,
177 SA_IGNORE,
178 SA_IGNORE,
179 SA_IGNORE,
180 SA_IGNORE,
181 SA_IGNORE,
182 SA_IGNORE,
183 SA_IGNORE,
184 SA_IGNORE,
185 SA_IGNORE,
186 SA_IGNORE,
187 SA_IGNORE,
188 SA_IGNORE,
189 SA_IGNORE,
190 SA_IGNORE,
191 SA_IGNORE,
192 SA_IGNORE,
193 SA_IGNORE,
194 SA_IGNORE,
195 SA_IGNORE,
196 SA_IGNORE,
197 SA_IGNORE,
198 SA_IGNORE,
199 SA_IGNORE,
200 SA_IGNORE,
201
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202};
203
204static __inline int
205sigprop(int sig)
206{
207
208 if (sig > 0 && sig < NSIG)
209 return (sigproptbl[_SIG_IDX(sig)]);
210 return (0);
211}
212
213static __inline int
214sig_ffs(sigset_t *set)
215{
216 int i;
217
218 for (i = 0; i < _SIG_WORDS; i++)
219 if (set->__bits[i])
220 return (ffs(set->__bits[i]) + (i * 32));
221 return (0);
222}
223
65957d54
DRJ
224int
225kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact)
984263bc 226{
65957d54
DRJ
227 struct thread *td = curthread;
228 struct proc *p = td->td_proc;
41c20dac 229 struct sigacts *ps = p->p_sigacts;
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230
231 if (sig <= 0 || sig > _SIG_MAXSIG)
232 return (EINVAL);
233
234 if (oact) {
235 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
236 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
237 oact->sa_flags = 0;
238 if (SIGISMEMBER(ps->ps_sigonstack, sig))
239 oact->sa_flags |= SA_ONSTACK;
240 if (!SIGISMEMBER(ps->ps_sigintr, sig))
241 oact->sa_flags |= SA_RESTART;
242 if (SIGISMEMBER(ps->ps_sigreset, sig))
243 oact->sa_flags |= SA_RESETHAND;
244 if (SIGISMEMBER(ps->ps_signodefer, sig))
245 oact->sa_flags |= SA_NODEFER;
246 if (SIGISMEMBER(ps->ps_siginfo, sig))
247 oact->sa_flags |= SA_SIGINFO;
248 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDSTOP)
249 oact->sa_flags |= SA_NOCLDSTOP;
250 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDWAIT)
251 oact->sa_flags |= SA_NOCLDWAIT;
252 }
253 if (act) {
254 if ((sig == SIGKILL || sig == SIGSTOP) &&
255 act->sa_handler != SIG_DFL)
256 return (EINVAL);
257
258 /*
259 * Change setting atomically.
260 */
8ebcad3f 261 splhigh();
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262
263 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
264 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
265 if (act->sa_flags & SA_SIGINFO) {
266 ps->ps_sigact[_SIG_IDX(sig)] =
267 (__sighandler_t *)act->sa_sigaction;
268 SIGADDSET(ps->ps_siginfo, sig);
269 } else {
270 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
271 SIGDELSET(ps->ps_siginfo, sig);
272 }
273 if (!(act->sa_flags & SA_RESTART))
274 SIGADDSET(ps->ps_sigintr, sig);
275 else
276 SIGDELSET(ps->ps_sigintr, sig);
277 if (act->sa_flags & SA_ONSTACK)
278 SIGADDSET(ps->ps_sigonstack, sig);
279 else
280 SIGDELSET(ps->ps_sigonstack, sig);
281 if (act->sa_flags & SA_RESETHAND)
282 SIGADDSET(ps->ps_sigreset, sig);
283 else
284 SIGDELSET(ps->ps_sigreset, sig);
285 if (act->sa_flags & SA_NODEFER)
286 SIGADDSET(ps->ps_signodefer, sig);
287 else
288 SIGDELSET(ps->ps_signodefer, sig);
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289 if (sig == SIGCHLD) {
290 if (act->sa_flags & SA_NOCLDSTOP)
291 p->p_procsig->ps_flag |= PS_NOCLDSTOP;
292 else
293 p->p_procsig->ps_flag &= ~PS_NOCLDSTOP;
294 if (act->sa_flags & SA_NOCLDWAIT) {
295 /*
296 * Paranoia: since SA_NOCLDWAIT is implemented
297 * by reparenting the dying child to PID 1 (and
298 * trust it to reap the zombie), PID 1 itself
299 * is forbidden to set SA_NOCLDWAIT.
300 */
301 if (p->p_pid == 1)
302 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT;
303 else
304 p->p_procsig->ps_flag |= PS_NOCLDWAIT;
8ebcad3f 305 } else {
984263bc 306 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT;
8ebcad3f 307 }
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308 }
309 /*
310 * Set bit in p_sigignore for signals that are set to SIG_IGN,
311 * and for signals set to SIG_DFL where the default is to
312 * ignore. However, don't put SIGCONT in p_sigignore, as we
313 * have to restart the process.
314 */
315 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
316 (sigprop(sig) & SA_IGNORE &&
317 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
318 /* never to be seen again */
319 SIGDELSET(p->p_siglist, sig);
320 if (sig != SIGCONT)
321 /* easier in psignal */
322 SIGADDSET(p->p_sigignore, sig);
323 SIGDELSET(p->p_sigcatch, sig);
324 } else {
325 SIGDELSET(p->p_sigignore, sig);
326 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
327 SIGDELSET(p->p_sigcatch, sig);
328 else
329 SIGADDSET(p->p_sigcatch, sig);
330 }
984263bc 331
8ebcad3f 332 spl0();
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333 }
334 return (0);
335}
336
984263bc 337int
41c20dac 338sigaction(struct sigaction_args *uap)
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339{
340 struct sigaction act, oact;
1fd87d54 341 struct sigaction *actp, *oactp;
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342 int error;
343
344 actp = (uap->act != NULL) ? &act : NULL;
345 oactp = (uap->oact != NULL) ? &oact : NULL;
346 if (actp) {
347 error = copyin(uap->act, actp, sizeof(act));
348 if (error)
349 return (error);
350 }
65957d54 351 error = kern_sigaction(uap->sig, actp, oactp);
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352 if (oactp && !error) {
353 error = copyout(oactp, uap->oact, sizeof(oact));
354 }
355 return (error);
356}
357
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358/*
359 * Initialize signal state for process 0;
360 * set to ignore signals that are ignored by default.
361 */
362void
8ebcad3f 363siginit(struct proc *p)
984263bc 364{
1fd87d54 365 int i;
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366
367 for (i = 1; i <= NSIG; i++)
368 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
369 SIGADDSET(p->p_sigignore, i);
370}
371
372/*
373 * Reset signals for an exec of the specified process.
374 */
375void
8ebcad3f 376execsigs(struct proc *p)
984263bc 377{
1fd87d54
RG
378 struct sigacts *ps = p->p_sigacts;
379 int sig;
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380
381 /*
382 * Reset caught signals. Held signals remain held
383 * through p_sigmask (unless they were caught,
384 * and are now ignored by default).
385 */
386 while (SIGNOTEMPTY(p->p_sigcatch)) {
387 sig = sig_ffs(&p->p_sigcatch);
388 SIGDELSET(p->p_sigcatch, sig);
389 if (sigprop(sig) & SA_IGNORE) {
390 if (sig != SIGCONT)
391 SIGADDSET(p->p_sigignore, sig);
392 SIGDELSET(p->p_siglist, sig);
393 }
394 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
395 }
396 /*
397 * Reset stack state to the user stack.
398 * Clear set of signals caught on the signal stack.
399 */
400 p->p_sigstk.ss_flags = SS_DISABLE;
401 p->p_sigstk.ss_size = 0;
402 p->p_sigstk.ss_sp = 0;
403 p->p_flag &= ~P_ALTSTACK;
404 /*
405 * Reset no zombies if child dies flag as Solaris does.
406 */
407 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT;
408}
409
410/*
65957d54 411 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
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412 *
413 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
414 * p == curproc. Also remember that in order to remain MP SAFE
415 * no spl*() calls may be made.
416 */
65957d54
DRJ
417int
418kern_sigprocmask(int how, sigset_t *set, sigset_t *oset)
984263bc 419{
65957d54
DRJ
420 struct thread *td = curthread;
421 struct proc *p = td->td_proc;
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MD
422 int error;
423
424 if (oset != NULL)
425 *oset = p->p_sigmask;
426
427 error = 0;
428 if (set != NULL) {
429 switch (how) {
430 case SIG_BLOCK:
431 SIG_CANTMASK(*set);
432 SIGSETOR(p->p_sigmask, *set);
433 break;
434 case SIG_UNBLOCK:
435 SIGSETNAND(p->p_sigmask, *set);
436 break;
437 case SIG_SETMASK:
438 SIG_CANTMASK(*set);
65957d54 439 p->p_sigmask = *set;
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440 break;
441 default:
442 error = EINVAL;
443 break;
444 }
445 }
446 return (error);
447}
448
449/*
450 * sigprocmask() - MP SAFE
451 */
984263bc 452int
41c20dac 453sigprocmask(struct sigprocmask_args *uap)
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MD
454{
455 sigset_t set, oset;
456 sigset_t *setp, *osetp;
457 int error;
458
459 setp = (uap->set != NULL) ? &set : NULL;
460 osetp = (uap->oset != NULL) ? &oset : NULL;
461 if (setp) {
462 error = copyin(uap->set, setp, sizeof(set));
463 if (error)
464 return (error);
465 }
65957d54 466 error = kern_sigprocmask(uap->how, setp, osetp);
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467 if (osetp && !error) {
468 error = copyout(osetp, uap->oset, sizeof(oset));
469 }
470 return (error);
471}
472
984263bc 473int
65957d54 474kern_sigpending(struct __sigset *set)
984263bc 475{
65957d54
DRJ
476 struct thread *td = curthread;
477 struct proc *p = td->td_proc;
984263bc 478
65957d54 479 *set = p->p_siglist;
984263bc 480
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481 return (0);
482}
483
984263bc 484int
65957d54 485sigpending(struct sigpending_args *uap)
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MD
486{
487 sigset_t set;
65957d54 488 int error;
984263bc 489
65957d54 490 error = kern_sigpending(&set);
984263bc 491
65957d54
DRJ
492 if (error == 0)
493 error = copyout(&set, uap->set, sizeof(set));
494 return (error);
984263bc 495}
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496
497/*
498 * Suspend process until signal, providing mask to be set
65957d54 499 * in the meantime.
984263bc 500 */
984263bc 501int
65957d54 502kern_sigsuspend(struct __sigset *set)
984263bc 503{
65957d54
DRJ
504 struct thread *td = curthread;
505 struct proc *p = td->td_proc;
41c20dac 506 struct sigacts *ps = p->p_sigacts;
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507
508 /*
509 * When returning from sigsuspend, we want
510 * the old mask to be restored after the
511 * signal handler has finished. Thus, we
512 * save it here and mark the sigacts structure
513 * to indicate this.
514 */
515 p->p_oldsigmask = p->p_sigmask;
516 p->p_flag |= P_OLDMASK;
517
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DRJ
518 SIG_CANTMASK(*set);
519 p->p_sigmask = *set;
520 while (tsleep(ps, PCATCH, "pause", 0) == 0)
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521 /* void */;
522 /* always return EINTR rather than ERESTART... */
523 return (EINTR);
524}
525
65957d54
DRJ
526/*
527 * Note nonstandard calling convention: libc stub passes mask, not
528 * pointer, to save a copyin.
529 */
984263bc 530int
65957d54 531sigsuspend(struct sigsuspend_args *uap)
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532{
533 sigset_t mask;
65957d54 534 int error;
984263bc 535
65957d54
DRJ
536 error = copyin(uap->sigmask, &mask, sizeof(mask));
537 if (error)
538 return (error);
539
540 error = kern_sigsuspend(&mask);
541
542 return (error);
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543}
544
984263bc 545int
65957d54 546kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss)
984263bc 547{
65957d54
DRJ
548 struct thread *td = curthread;
549 struct proc *p = td->td_proc;
984263bc 550
65957d54
DRJ
551 if ((p->p_flag & P_ALTSTACK) == 0)
552 p->p_sigstk.ss_flags |= SS_DISABLE;
553
554 if (oss)
555 *oss = p->p_sigstk;
556
557 if (ss) {
558 if (ss->ss_flags & SS_DISABLE) {
559 if (p->p_sigstk.ss_flags & SS_ONSTACK)
560 return (EINVAL);
561 p->p_flag &= ~P_ALTSTACK;
562 p->p_sigstk.ss_flags = ss->ss_flags;
563 } else {
564 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
565 return (ENOMEM);
566 p->p_flag |= P_ALTSTACK;
567 p->p_sigstk = *ss;
568 }
984263bc 569 }
65957d54
DRJ
570
571 return (0);
984263bc 572}
984263bc 573
984263bc 574int
41c20dac 575sigaltstack(struct sigaltstack_args *uap)
984263bc 576{
65957d54 577 stack_t ss, oss;
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578 int error;
579
65957d54
DRJ
580 if (uap->ss) {
581 error = copyin(uap->ss, &ss, sizeof(ss));
582 if (error)
583 return (error);
984263bc 584 }
65957d54
DRJ
585
586 error = kern_sigaltstack(uap->ss ? &ss : NULL,
587 uap->oss ? &oss : NULL);
588
589 if (error == 0 && uap->oss)
590 error = copyout(&oss, uap->oss, sizeof(*uap->oss));
591 return (error);
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592}
593
594/*
595 * Common code for kill process group/broadcast kill.
596 * cp is calling process.
597 */
65957d54
DRJ
598static int
599killpg(int sig, int pgid, int all)
984263bc 600{
41c20dac
MD
601 struct proc *cp = curproc;
602 struct proc *p;
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603 struct pgrp *pgrp;
604 int nfound = 0;
605
8ebcad3f 606 if (all) {
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607 /*
608 * broadcast
609 */
f62004ad 610 FOREACH_PROC_IN_SYSTEM(p) {
984263bc 611 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
41c20dac 612 p == cp || !CANSIGNAL(p, sig))
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613 continue;
614 nfound++;
615 if (sig)
616 psignal(p, sig);
617 }
8ebcad3f
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618 } else {
619 if (pgid == 0) {
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620 /*
621 * zero pgid means send to my process group.
622 */
623 pgrp = cp->p_pgrp;
8ebcad3f 624 } else {
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625 pgrp = pgfind(pgid);
626 if (pgrp == NULL)
627 return (ESRCH);
628 }
629 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
630 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
631 p->p_stat == SZOMB ||
41c20dac 632 !CANSIGNAL(p, sig))
984263bc
MD
633 continue;
634 nfound++;
635 if (sig)
636 psignal(p, sig);
637 }
638 }
639 return (nfound ? 0 : ESRCH);
640}
641
984263bc 642int
65957d54 643kern_kill(int sig, int pid)
984263bc 644{
65957d54
DRJ
645 struct thread *td = curthread;
646 struct proc *p = td->td_proc;
984263bc 647
65957d54 648 if ((u_int)sig > _SIG_MAXSIG)
984263bc 649 return (EINVAL);
65957d54 650 if (pid > 0) {
984263bc 651 /* kill single process */
65957d54 652 if ((p = pfind(pid)) == NULL)
984263bc 653 return (ESRCH);
65957d54 654 if (!CANSIGNAL(p, sig))
984263bc 655 return (EPERM);
65957d54
DRJ
656 if (sig)
657 psignal(p, sig);
984263bc
MD
658 return (0);
659 }
65957d54 660 switch (pid) {
984263bc 661 case -1: /* broadcast signal */
65957d54 662 return (killpg(sig, 0, 1));
984263bc 663 case 0: /* signal own process group */
65957d54 664 return (killpg(sig, 0, 0));
984263bc 665 default: /* negative explicit process group */
65957d54 666 return (killpg(sig, -pid, 0));
984263bc
MD
667 }
668 /* NOTREACHED */
669}
670
984263bc 671int
65957d54 672kill(struct kill_args *uap)
984263bc 673{
65957d54
DRJ
674 int error;
675
676 error = kern_kill(uap->signum, uap->pid);
677
678 return (error);
984263bc 679}
984263bc
MD
680
681/*
682 * Send a signal to a process group.
683 */
684void
41c20dac 685gsignal(int pgid, int sig)
984263bc
MD
686{
687 struct pgrp *pgrp;
688
689 if (pgid && (pgrp = pgfind(pgid)))
690 pgsignal(pgrp, sig, 0);
691}
692
693/*
694 * Send a signal to a process group. If checktty is 1,
695 * limit to members which have a controlling terminal.
696 */
697void
8ebcad3f 698pgsignal(struct pgrp *pgrp, int sig, int checkctty)
984263bc 699{
1fd87d54 700 struct proc *p;
984263bc
MD
701
702 if (pgrp)
703 LIST_FOREACH(p, &pgrp->pg_members, p_pglist)
704 if (checkctty == 0 || p->p_flag & P_CONTROLT)
705 psignal(p, sig);
706}
707
708/*
709 * Send a signal caused by a trap to the current process.
710 * If it will be caught immediately, deliver it with correct code.
711 * Otherwise, post it normally.
712 */
713void
8ebcad3f 714trapsignal(struct proc *p, int sig, u_long code)
984263bc 715{
dadab5e9 716 struct sigacts *ps = p->p_sigacts;
984263bc
MD
717
718 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
719 !SIGISMEMBER(p->p_sigmask, sig)) {
720 p->p_stats->p_ru.ru_nsignals++;
721#ifdef KTRACE
dadab5e9 722 if (KTRPOINT(p->p_thread, KTR_PSIG))
984263bc
MD
723 ktrpsig(p->p_tracep, sig, ps->ps_sigact[_SIG_IDX(sig)],
724 &p->p_sigmask, code);
725#endif
726 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
727 &p->p_sigmask, code);
728 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
729 if (!SIGISMEMBER(ps->ps_signodefer, sig))
730 SIGADDSET(p->p_sigmask, sig);
731 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
732 /*
65957d54 733 * See kern_sigaction() for origin of this code.
984263bc
MD
734 */
735 SIGDELSET(p->p_sigcatch, sig);
736 if (sig != SIGCONT &&
737 sigprop(sig) & SA_IGNORE)
738 SIGADDSET(p->p_sigignore, sig);
739 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
740 }
741 } else {
742 p->p_code = code; /* XXX for core dump/debugger */
743 p->p_sig = sig; /* XXX to verify code */
744 psignal(p, sig);
745 }
746}
747
748/*
749 * Send the signal to the process. If the signal has an action, the action
750 * is usually performed by the target process rather than the caller; we add
751 * the signal to the set of pending signals for the process.
752 *
753 * Exceptions:
754 * o When a stop signal is sent to a sleeping process that takes the
755 * default action, the process is stopped without awakening it.
756 * o SIGCONT restarts stopped processes (or puts them back to sleep)
757 * regardless of the signal action (eg, blocked or ignored).
758 *
759 * Other ignored signals are discarded immediately.
760 */
cb973d15 761
9d63d5c0
MD
762/*
763 * temporary hack to allow checkpoint code to continue to
764 * be in a module for the moment
765 */
766
984263bc 767void
8ebcad3f 768psignal(struct proc *p, int sig)
984263bc 769{
cb973d15
MD
770 int s, prop;
771 sig_t action;
984263bc
MD
772
773 if (sig > _SIG_MAXSIG || sig <= 0) {
774 printf("psignal: signal %d\n", sig);
775 panic("psignal signal number");
776 }
777
778 s = splhigh();
779 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
780 splx(s);
781
782 prop = sigprop(sig);
783
784 /*
785 * If proc is traced, always give parent a chance;
786 * if signal event is tracked by procfs, give *that*
787 * a chance, as well.
788 */
8ebcad3f 789 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) {
984263bc 790 action = SIG_DFL;
8ebcad3f 791 } else {
984263bc
MD
792 /*
793 * If the signal is being ignored,
794 * then we forget about it immediately.
795 * (Note: we don't set SIGCONT in p_sigignore,
796 * and if it is set to SIG_IGN,
797 * action will be SIG_DFL here.)
798 */
799 if (SIGISMEMBER(p->p_sigignore, sig) || (p->p_flag & P_WEXIT))
800 return;
801 if (SIGISMEMBER(p->p_sigmask, sig))
802 action = SIG_HOLD;
803 else if (SIGISMEMBER(p->p_sigcatch, sig))
804 action = SIG_CATCH;
805 else
806 action = SIG_DFL;
807 }
808
809 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
8ebcad3f 810 (p->p_flag & P_TRACED) == 0) {
984263bc 811 p->p_nice = NZERO;
8ebcad3f 812 }
984263bc
MD
813
814 if (prop & SA_CONT)
815 SIG_STOPSIGMASK(p->p_siglist);
9d63d5c0 816
984263bc
MD
817
818 if (prop & SA_STOP) {
819 /*
820 * If sending a tty stop signal to a member of an orphaned
821 * process group, discard the signal here if the action
822 * is default; don't stop the process below if sleeping,
823 * and don't clear any pending SIGCONT.
824 */
825 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
8ebcad3f 826 action == SIG_DFL) {
984263bc 827 return;
8ebcad3f 828 }
984263bc
MD
829 SIG_CONTSIGMASK(p->p_siglist);
830 }
831 SIGADDSET(p->p_siglist, sig);
832
833 /*
834 * Defer further processing for signals which are held,
835 * except that stopped processes must be continued by SIGCONT.
836 */
837 if (action == SIG_HOLD && (!(prop & SA_CONT) || p->p_stat != SSTOP))
838 return;
839 s = splhigh();
840 switch (p->p_stat) {
984263bc
MD
841 case SSLEEP:
842 /*
843 * If process is sleeping uninterruptibly
844 * we can't interrupt the sleep... the signal will
845 * be noticed when the process returns through
846 * trap() or syscall().
847 */
848 if ((p->p_flag & P_SINTR) == 0)
849 goto out;
850 /*
851 * Process is sleeping and traced... make it runnable
852 * so it can discover the signal in issignal() and stop
853 * for the parent.
854 */
855 if (p->p_flag & P_TRACED)
856 goto run;
857 /*
858 * If SIGCONT is default (or ignored) and process is
859 * asleep, we are finished; the process should not
860 * be awakened.
861 */
862 if ((prop & SA_CONT) && action == SIG_DFL) {
863 SIGDELSET(p->p_siglist, sig);
864 goto out;
865 }
866 /*
867 * When a sleeping process receives a stop
868 * signal, process immediately if possible.
869 * All other (caught or default) signals
870 * cause the process to run.
871 */
872 if (prop & SA_STOP) {
873 if (action != SIG_DFL)
26a0694b 874 goto run;
984263bc
MD
875 /*
876 * If a child holding parent blocked,
877 * stopping could cause deadlock.
878 */
879 if (p->p_flag & P_PPWAIT)
880 goto out;
881 SIGDELSET(p->p_siglist, sig);
882 p->p_xstat = sig;
883 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0)
884 psignal(p->p_pptr, SIGCHLD);
885 stop(p);
886 goto out;
8ebcad3f 887 } else {
26a0694b 888 goto run;
8ebcad3f 889 }
984263bc 890 /*NOTREACHED*/
984263bc
MD
891 case SSTOP:
892 /*
893 * If traced process is already stopped,
894 * then no further action is necessary.
895 */
896 if (p->p_flag & P_TRACED)
897 goto out;
898
899 /*
900 * Kill signal always sets processes running.
901 */
902 if (sig == SIGKILL)
26a0694b 903 goto run;
984263bc
MD
904
905 if (prop & SA_CONT) {
906 /*
907 * If SIGCONT is default (or ignored), we continue the
908 * process but don't leave the signal in p_siglist, as
909 * it has no further action. If SIGCONT is held, we
910 * continue the process and leave the signal in
911 * p_siglist. If the process catches SIGCONT, let it
912 * handle the signal itself. If it isn't waiting on
913 * an event, then it goes back to run state.
914 * Otherwise, process goes back to sleep state.
915 */
916 if (action == SIG_DFL)
917 SIGDELSET(p->p_siglist, sig);
918 if (action == SIG_CATCH)
26a0694b 919 goto run;
984263bc
MD
920 if (p->p_wchan == 0)
921 goto run;
26a0694b 922 clrrunnable(p, SSLEEP);
984263bc
MD
923 goto out;
924 }
925
926 if (prop & SA_STOP) {
927 /*
928 * Already stopped, don't need to stop again.
929 * (If we did the shell could get confused.)
930 */
931 SIGDELSET(p->p_siglist, sig);
932 goto out;
933 }
934
935 /*
936 * If process is sleeping interruptibly, then simulate a
937 * wakeup so that when it is continued, it will be made
938 * runnable and can look at the signal. But don't make
939 * the process runnable, leave it stopped.
940 */
92e4c1e5 941 if (p->p_wchan && (p->p_flag & P_SINTR))
0cfcada1 942 unsleep(p->p_thread);
984263bc 943 goto out;
984263bc
MD
944 default:
945 /*
946 * SRUN, SIDL, SZOMB do nothing with the signal,
947 * other than kicking ourselves if we are running.
948 * It will either never be noticed, or noticed very soon.
cb973d15 949 *
5fd012e0
MD
950 * Note that p_thread may be NULL or may not be completely
951 * initialized if the process is in the SIDL or SZOMB state.
952 *
cb973d15
MD
953 * For SMP we may have to forward the request to another cpu.
954 * YYY the MP lock prevents the target process from moving
955 * to another cpu, see kern/kern_switch.c
60be1d11
MD
956 *
957 * If the target thread is waiting on its message port,
958 * wakeup the target thread so it can check (or ignore)
959 * the new signal. YYY needs cleanup.
984263bc 960 */
984263bc 961#ifdef SMP
cb973d15 962 if (p == lwkt_preempted_proc()) {
235957ed 963 signotify();
5fd012e0 964 } else if (p->p_stat == SRUN) {
a72187e9
MD
965 struct thread *td = p->p_thread;
966
5fd012e0
MD
967 KASSERT(td != NULL,
968 ("pid %d NULL p_thread stat %d flags %08x",
969 p->p_pid, p->p_stat, p->p_flag));
970
a72187e9 971 if (td->td_gd != mycpu)
2db3b277 972 lwkt_send_ipiq(td->td_gd, signotify_remote, p);
60be1d11
MD
973 else if (td->td_msgport.mp_flags & MSGPORTF_WAITING)
974 lwkt_schedule(td);
cb973d15
MD
975 }
976#else
60be1d11 977 if (p == lwkt_preempted_proc()) {
235957ed 978 signotify();
5fd012e0 979 } else if (p->p_stat == SRUN) {
60be1d11 980 struct thread *td = p->p_thread;
5fd012e0
MD
981
982 KASSERT(td != NULL,
983 ("pid %d NULL p_thread stat %d flags %08x",
984 p->p_pid, p->p_stat, p->p_flag));
985
60be1d11
MD
986 if (td->td_msgport.mp_flags & MSGPORTF_WAITING)
987 lwkt_schedule(td);
988 }
984263bc
MD
989#endif
990 goto out;
991 }
992 /*NOTREACHED*/
984263bc
MD
993run:
994 setrunnable(p);
995out:
996 splx(s);
997}
998
cb973d15
MD
999#ifdef SMP
1000
1001/*
1002 * This function is called via an IPI. We will be in a critical section but
1003 * the MP lock will NOT be held. Also note that by the time the ipi message
1004 * gets to us the process 'p' (arg) may no longer be scheduled or even valid.
1005 */
1006static void
1007signotify_remote(void *arg)
1008{
1009 struct proc *p = arg;
60be1d11
MD
1010
1011 if (p == lwkt_preempted_proc()) {
235957ed 1012 signotify();
60be1d11
MD
1013 } else {
1014 struct thread *td = p->p_thread;
1015 if (td->td_msgport.mp_flags & MSGPORTF_WAITING)
1016 lwkt_schedule(td);
1017 }
cb973d15
MD
1018}
1019
1020#endif
1021
a94976ad
MD
1022/*
1023 * If the current process has received a signal that would interrupt a
1024 * system call, return EINTR or ERESTART as appropriate.
1025 */
1026int
1027iscaught(struct proc *p)
1028{
1029 int sig;
1030
1031 if (p) {
1032 if ((sig = CURSIG(p)) != 0) {
1033 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1034 return (EINTR);
1035 return (ERESTART);
1036 }
1037 }
1038 return(EWOULDBLOCK);
1039}
1040
984263bc
MD
1041/*
1042 * If the current process has received a signal (should be caught or cause
1043 * termination, should interrupt current syscall), return the signal number.
1044 * Stop signals with default action are processed immediately, then cleared;
1045 * they aren't returned. This is checked after each entry to the system for
1046 * a syscall or trap (though this can usually be done without calling issignal
1047 * by checking the pending signal masks in the CURSIG macro.) The normal call
1048 * sequence is
1049 *
1050 * while (sig = CURSIG(curproc))
1051 * postsig(sig);
1052 */
1053int
8ebcad3f 1054issignal(struct proc *p)
984263bc
MD
1055{
1056 sigset_t mask;
1fd87d54 1057 int sig, prop;
984263bc
MD
1058
1059 for (;;) {
1060 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
1061
1062 mask = p->p_siglist;
1063 SIGSETNAND(mask, p->p_sigmask);
1064 if (p->p_flag & P_PPWAIT)
1065 SIG_STOPSIGMASK(mask);
1066 if (!SIGNOTEMPTY(mask)) /* no signal to send */
1067 return (0);
1068 sig = sig_ffs(&mask);
1069
1070 STOPEVENT(p, S_SIG, sig);
1071
1072 /*
1073 * We should see pending but ignored signals
1074 * only if P_TRACED was on when they were posted.
1075 */
1076 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
1077 SIGDELSET(p->p_siglist, sig);
1078 continue;
1079 }
1080 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) {
1081 /*
1082 * If traced, always stop, and stay
1083 * stopped until released by the parent.
1084 */
1085 p->p_xstat = sig;
1086 psignal(p->p_pptr, SIGCHLD);
1087 do {
1088 stop(p);
37af14fe 1089 mi_switch(p);
26a0694b 1090 } while (!trace_req(p) && p->p_flag & P_TRACED);
984263bc
MD
1091
1092 /*
1093 * If parent wants us to take the signal,
1094 * then it will leave it in p->p_xstat;
1095 * otherwise we just look for signals again.
1096 */
1097 SIGDELSET(p->p_siglist, sig); /* clear old signal */
1098 sig = p->p_xstat;
1099 if (sig == 0)
1100 continue;
1101
1102 /*
1103 * Put the new signal into p_siglist. If the
1104 * signal is being masked, look for other signals.
1105 */
1106 SIGADDSET(p->p_siglist, sig);
1107 if (SIGISMEMBER(p->p_sigmask, sig))
1108 continue;
1109
1110 /*
1111 * If the traced bit got turned off, go back up
1112 * to the top to rescan signals. This ensures
1113 * that p_sig* and ps_sigact are consistent.
1114 */
1115 if ((p->p_flag & P_TRACED) == 0)
1116 continue;
1117 }
1118
1119 prop = sigprop(sig);
1120
1121 /*
1122 * Decide whether the signal should be returned.
1123 * Return the signal's number, or fall through
1124 * to clear it from the pending mask.
1125 */
1126 switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
1127
1128 case (int)SIG_DFL:
1129 /*
1130 * Don't take default actions on system processes.
1131 */
1132 if (p->p_pid <= 1) {
1133#ifdef DIAGNOSTIC
1134 /*
1135 * Are you sure you want to ignore SIGSEGV
1136 * in init? XXX
1137 */
1138 printf("Process (pid %lu) got signal %d\n",
1139 (u_long)p->p_pid, sig);
1140#endif
1141 break; /* == ignore */
1142 }
f758a39e
MD
1143
1144 /*
1145 * Handle the in-kernel checkpoint action
1146 */
1147 if (prop & SA_CKPT) {
0ba6fbbf 1148 checkpoint_signal_handler(p);
f758a39e
MD
1149 break;
1150 }
1151
984263bc
MD
1152 /*
1153 * If there is a pending stop signal to process
1154 * with default action, stop here,
1155 * then clear the signal. However,
1156 * if process is member of an orphaned
1157 * process group, ignore tty stop signals.
1158 */
1159 if (prop & SA_STOP) {
1160 if (p->p_flag & P_TRACED ||
1161 (p->p_pgrp->pg_jobc == 0 &&
1162 prop & SA_TTYSTOP))
1163 break; /* == ignore */
1164 p->p_xstat = sig;
1165 stop(p);
1166 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0)
1167 psignal(p->p_pptr, SIGCHLD);
37af14fe 1168 mi_switch(p);
984263bc
MD
1169 break;
1170 } else if (prop & SA_IGNORE) {
1171 /*
1172 * Except for SIGCONT, shouldn't get here.
1173 * Default action is to ignore; drop it.
1174 */
1175 break; /* == ignore */
8ebcad3f 1176 } else {
984263bc 1177 return (sig);
8ebcad3f
MD
1178 }
1179
984263bc
MD
1180 /*NOTREACHED*/
1181
1182 case (int)SIG_IGN:
1183 /*
1184 * Masking above should prevent us ever trying
1185 * to take action on an ignored signal other
1186 * than SIGCONT, unless process is traced.
1187 */
1188 if ((prop & SA_CONT) == 0 &&
1189 (p->p_flag & P_TRACED) == 0)
1190 printf("issignal\n");
1191 break; /* == ignore */
1192
1193 default:
1194 /*
1195 * This signal has an action, let
1196 * postsig() process it.
1197 */
1198 return (sig);
1199 }
1200 SIGDELSET(p->p_siglist, sig); /* take the signal! */
1201 }
1202 /* NOTREACHED */
1203}
1204
1205/*
1206 * Put the argument process into the stopped state and notify the parent
1207 * via wakeup. Signals are handled elsewhere. The process must not be
1208 * on the run queue.
1209 */
1210void
8ebcad3f 1211stop(struct proc *p)
984263bc 1212{
984263bc
MD
1213 p->p_stat = SSTOP;
1214 p->p_flag &= ~P_WAITED;
1215 wakeup((caddr_t)p->p_pptr);
1216}
1217
1218/*
1219 * Take the action for the specified signal
1220 * from the current set of pending signals.
1221 */
1222void
8ebcad3f 1223postsig(int sig)
984263bc 1224{
41c20dac 1225 struct proc *p = curproc;
984263bc
MD
1226 struct sigacts *ps = p->p_sigacts;
1227 sig_t action;
1228 sigset_t returnmask;
1229 int code;
1230
1231 KASSERT(sig != 0, ("postsig"));
1232
1233 SIGDELSET(p->p_siglist, sig);
1234 action = ps->ps_sigact[_SIG_IDX(sig)];
1235#ifdef KTRACE
dadab5e9 1236 if (KTRPOINT(p->p_thread, KTR_PSIG))
984263bc
MD
1237 ktrpsig(p->p_tracep, sig, action, p->p_flag & P_OLDMASK ?
1238 &p->p_oldsigmask : &p->p_sigmask, 0);
1239#endif
1240 STOPEVENT(p, S_SIG, sig);
1241
1242 if (action == SIG_DFL) {
1243 /*
1244 * Default action, where the default is to kill
1245 * the process. (Other cases were ignored above.)
1246 */
1247 sigexit(p, sig);
1248 /* NOTREACHED */
1249 } else {
1250 /*
1251 * If we get here, the signal must be caught.
1252 */
1253 KASSERT(action != SIG_IGN && !SIGISMEMBER(p->p_sigmask, sig),
1254 ("postsig action"));
1255 /*
1256 * Set the new mask value and also defer further
1257 * occurrences of this signal.
1258 *
1259 * Special case: user has done a sigsuspend. Here the
1260 * current mask is not of interest, but rather the
1261 * mask from before the sigsuspend is what we want
1262 * restored after the signal processing is completed.
1263 */
8ebcad3f 1264 splhigh();
984263bc
MD
1265 if (p->p_flag & P_OLDMASK) {
1266 returnmask = p->p_oldsigmask;
1267 p->p_flag &= ~P_OLDMASK;
8ebcad3f 1268 } else {
984263bc 1269 returnmask = p->p_sigmask;
8ebcad3f 1270 }
984263bc
MD
1271
1272 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
1273 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1274 SIGADDSET(p->p_sigmask, sig);
1275
1276 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
1277 /*
65957d54 1278 * See kern_sigaction() for origin of this code.
984263bc
MD
1279 */
1280 SIGDELSET(p->p_sigcatch, sig);
1281 if (sig != SIGCONT &&
1282 sigprop(sig) & SA_IGNORE)
1283 SIGADDSET(p->p_sigignore, sig);
1284 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1285 }
8ebcad3f 1286 spl0();
984263bc
MD
1287 p->p_stats->p_ru.ru_nsignals++;
1288 if (p->p_sig != sig) {
1289 code = 0;
1290 } else {
1291 code = p->p_code;
1292 p->p_code = 0;
1293 p->p_sig = 0;
1294 }
1295 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
1296 }
1297}
1298
1299/*
1300 * Kill the current process for stated reason.
1301 */
1302void
8ebcad3f 1303killproc(struct proc *p, char *why)
984263bc
MD
1304{
1305 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm,
41c20dac 1306 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
984263bc
MD
1307 psignal(p, SIGKILL);
1308}
1309
1310/*
1311 * Force the current process to exit with the specified signal, dumping core
1312 * if appropriate. We bypass the normal tests for masked and caught signals,
1313 * allowing unrecoverable failures to terminate the process without changing
1314 * signal state. Mark the accounting record with the signal termination.
1315 * If dumping core, save the signal number for the debugger. Calls exit and
1316 * does not return.
1317 */
1318void
41c20dac 1319sigexit(struct proc *p, int sig)
984263bc 1320{
984263bc
MD
1321 p->p_acflag |= AXSIG;
1322 if (sigprop(sig) & SA_CORE) {
1323 p->p_sig = sig;
1324 /*
1325 * Log signals which would cause core dumps
1326 * (Log as LOG_INFO to appease those who don't want
1327 * these messages.)
1328 * XXX : Todo, as well as euid, write out ruid too
1329 */
1330 if (coredump(p) == 0)
1331 sig |= WCOREFLAG;
1332 if (kern_logsigexit)
1333 log(LOG_INFO,
1334 "pid %d (%s), uid %d: exited on signal %d%s\n",
1335 p->p_pid, p->p_comm,
41c20dac 1336 p->p_ucred ? p->p_ucred->cr_uid : -1,
984263bc
MD
1337 sig &~ WCOREFLAG,
1338 sig & WCOREFLAG ? " (core dumped)" : "");
1339 }
41c20dac 1340 exit1(W_EXITCODE(0, sig));
984263bc
MD
1341 /* NOTREACHED */
1342}
1343
1344static char corefilename[MAXPATHLEN+1] = {"%N.core"};
1345SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
1346 sizeof(corefilename), "process corefile name format string");
1347
1348/*
1349 * expand_name(name, uid, pid)
1350 * Expand the name described in corefilename, using name, uid, and pid.
1351 * corefilename is a printf-like string, with three format specifiers:
1352 * %N name of process ("name")
1353 * %P process id (pid)
1354 * %U user id (uid)
1355 * For example, "%N.core" is the default; they can be disabled completely
1356 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
1357 * This is controlled by the sysctl variable kern.corefile (see above).
1358 */
1359
1360static char *
8ebcad3f
MD
1361expand_name(const char *name, uid_t uid, pid_t pid)
1362{
984263bc
MD
1363 char *temp;
1364 char buf[11]; /* Buffer for pid/uid -- max 4B */
1365 int i, n;
1366 char *format = corefilename;
1367 size_t namelen;
1368
1369 temp = malloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
1370 if (temp == NULL)
1371 return NULL;
1372 namelen = strlen(name);
1373 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
1374 int l;
1375 switch (format[i]) {
1376 case '%': /* Format character */
1377 i++;
1378 switch (format[i]) {
1379 case '%':
1380 temp[n++] = '%';
1381 break;
1382 case 'N': /* process name */
1383 if ((n + namelen) > MAXPATHLEN) {
1384 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1385 pid, name, uid, temp, name);
1386 free(temp, M_TEMP);
1387 return NULL;
1388 }
1389 memcpy(temp+n, name, namelen);
1390 n += namelen;
1391 break;
1392 case 'P': /* process id */
1393 l = sprintf(buf, "%u", pid);
1394 if ((n + l) > MAXPATHLEN) {
1395 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1396 pid, name, uid, temp, name);
1397 free(temp, M_TEMP);
1398 return NULL;
1399 }
1400 memcpy(temp+n, buf, l);
1401 n += l;
1402 break;
1403 case 'U': /* user id */
1404 l = sprintf(buf, "%u", uid);
1405 if ((n + l) > MAXPATHLEN) {
1406 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1407 pid, name, uid, temp, name);
1408 free(temp, M_TEMP);
1409 return NULL;
1410 }
1411 memcpy(temp+n, buf, l);
1412 n += l;
1413 break;
1414 default:
1415 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
1416 }
1417 break;
1418 default:
1419 temp[n++] = format[i];
1420 }
1421 }
1422 temp[n] = '\0';
1423 return temp;
1424}
1425
1426/*
1427 * Dump a process' core. The main routine does some
1428 * policy checking, and creates the name of the coredump;
1429 * then it passes on a vnode and a size limit to the process-specific
1430 * coredump routine if there is one; if there _is not_ one, it returns
1431 * ENOSYS; otherwise it returns the error from the process-specific routine.
1432 */
1433
1434static int
dadab5e9 1435coredump(struct proc *p)
984263bc 1436{
dadab5e9
MD
1437 struct vnode *vp;
1438 struct ucred *cred = p->p_ucred;
1439 struct thread *td = p->p_thread;
984263bc 1440 struct flock lf;
fad57d0e 1441 struct nlookupdata nd;
984263bc
MD
1442 struct vattr vattr;
1443 int error, error1;
1444 char *name; /* name of corefile */
1445 off_t limit;
1446
1447 STOPEVENT(p, S_CORE, 0);
1448
1449 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0)
1450 return (EFAULT);
1451
1452 /*
1453 * Note that the bulk of limit checking is done after
1454 * the corefile is created. The exception is if the limit
1455 * for corefiles is 0, in which case we don't bother
1456 * creating the corefile at all. This layout means that
1457 * a corefile is truncated instead of not being created,
1458 * if it is larger than the limit.
1459 */
1460 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
1461 if (limit == 0)
50fd5388 1462 return EFBIG;
984263bc
MD
1463
1464 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
1465 if (name == NULL)
1466 return (EINVAL);
fad57d0e
MD
1467 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
1468 if (error == 0)
1469 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
984263bc 1470 free(name, M_TEMP);
fad57d0e
MD
1471 if (error) {
1472 nlookup_done(&nd);
984263bc 1473 return (error);
fad57d0e
MD
1474 }
1475 vp = nd.nl_open_vp;
1476 nd.nl_open_vp = NULL;
1477 nlookup_done(&nd);
984263bc 1478
5fd012e0 1479 VOP_UNLOCK(vp, 0, td);
984263bc
MD
1480 lf.l_whence = SEEK_SET;
1481 lf.l_start = 0;
1482 lf.l_len = 0;
1483 lf.l_type = F_WRLCK;
1484 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK);
1485 if (error)
1486 goto out2;
1487
1488 /* Don't dump to non-regular files or files with links. */
1489 if (vp->v_type != VREG ||
3b568787 1490 VOP_GETATTR(vp, &vattr, td) || vattr.va_nlink != 1) {
984263bc
MD
1491 error = EFAULT;
1492 goto out1;
1493 }
1494
1495 VATTR_NULL(&vattr);
5fd012e0 1496 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
984263bc 1497 vattr.va_size = 0;
dadab5e9
MD
1498 VOP_LEASE(vp, td, cred, LEASE_WRITE);
1499 VOP_SETATTR(vp, &vattr, cred, td);
984263bc 1500 p->p_acflag |= ACORE;
5fd012e0 1501 VOP_UNLOCK(vp, 0, td);
984263bc
MD
1502
1503 error = p->p_sysent->sv_coredump ?
fad57d0e 1504 p->p_sysent->sv_coredump(p, vp, limit) : ENOSYS;
984263bc
MD
1505
1506out1:
1507 lf.l_type = F_UNLCK;
1508 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
1509out2:
3b568787 1510 error1 = vn_close(vp, FWRITE, td);
984263bc
MD
1511 if (error == 0)
1512 error = error1;
1513 return (error);
1514}
1515
1516/*
1517 * Nonexistent system call-- signal process (may want to handle it).
1518 * Flag error in case process won't see signal immediately (blocked or ignored).
1519 */
984263bc
MD
1520/* ARGSUSED */
1521int
41c20dac 1522nosys(struct nosys_args *args)
984263bc 1523{
41c20dac 1524 psignal(curproc, SIGSYS);
984263bc
MD
1525 return (EINVAL);
1526}
1527
1528/*
1529 * Send a SIGIO or SIGURG signal to a process or process group using
1530 * stored credentials rather than those of the current process.
1531 */
1532void
dadab5e9 1533pgsigio(struct sigio *sigio, int sig, int checkctty)
984263bc
MD
1534{
1535 if (sigio == NULL)
1536 return;
1537
1538 if (sigio->sio_pgid > 0) {
1539 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
1540 sigio->sio_proc))
1541 psignal(sigio->sio_proc, sig);
1542 } else if (sigio->sio_pgid < 0) {
1543 struct proc *p;
1544
1545 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist)
1546 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
1547 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
1548 psignal(p, sig);
1549 }
1550}
1551
1552static int
1553filt_sigattach(struct knote *kn)
1554{
1555 struct proc *p = curproc;
1556
1557 kn->kn_ptr.p_proc = p;
1558 kn->kn_flags |= EV_CLEAR; /* automatically set */
1559
1560 /* XXX lock the proc here while adding to the list? */
1561 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext);
1562
1563 return (0);
1564}
1565
1566static void
1567filt_sigdetach(struct knote *kn)
1568{
1569 struct proc *p = kn->kn_ptr.p_proc;
1570
1571 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext);
1572}
1573
1574/*
1575 * signal knotes are shared with proc knotes, so we apply a mask to
1576 * the hint in order to differentiate them from process hints. This
1577 * could be avoided by using a signal-specific knote list, but probably
1578 * isn't worth the trouble.
1579 */
1580static int
1581filt_signal(struct knote *kn, long hint)
1582{
984263bc
MD
1583 if (hint & NOTE_SIGNAL) {
1584 hint &= ~NOTE_SIGNAL;
1585
1586 if (kn->kn_id == hint)
1587 kn->kn_data++;
1588 }
1589 return (kn->kn_data != 0);
1590}