Fix comment.
[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 $
344ad853 40 * $DragonFly: src/sys/kern/kern_sig.c,v 1.39 2005/11/14 18:50:05 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>
e43a034f 68#include <sys/thread2.h>
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69
70
71#include <machine/ipl.h>
72#include <machine/cpu.h>
73#include <machine/smp.h>
74
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75static int coredump(struct proc *);
76static char *expand_name(const char *, uid_t, pid_t);
77static int killpg(int sig, int pgid, int all);
78static int sig_ffs(sigset_t *set);
79static int sigprop(int sig);
cb973d15 80#ifdef SMP
8ebcad3f 81static void signotify_remote(void *arg);
cb973d15 82#endif
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83static int kern_sigtimedwait(sigset_t set, siginfo_t *info,
84 struct timespec *timeout);
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85
86static int filt_sigattach(struct knote *kn);
87static void filt_sigdetach(struct knote *kn);
88static int filt_signal(struct knote *kn, long hint);
89
90struct filterops sig_filtops =
91 { 0, filt_sigattach, filt_sigdetach, filt_signal };
92
93static int kern_logsigexit = 1;
94SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
95 &kern_logsigexit, 0,
96 "Log processes quitting on abnormal signals to syslog(3)");
97
98/*
99 * Can process p, with pcred pc, send the signal sig to process q?
100 */
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101#define CANSIGNAL(q, sig) \
102 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \
103 ((sig) == SIGCONT && (q)->p_session == curproc->p_session))
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104
105/*
106 * Policy -- Can real uid ruid with ucred uc send a signal to process q?
107 */
108#define CANSIGIO(ruid, uc, q) \
109 ((uc)->cr_uid == 0 || \
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110 (ruid) == (q)->p_ucred->cr_ruid || \
111 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \
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112 (ruid) == (q)->p_ucred->cr_uid || \
113 (uc)->cr_uid == (q)->p_ucred->cr_uid)
114
115int sugid_coredump;
116SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
8ebcad3f 117 &sugid_coredump, 0, "Enable coredumping set user/group ID processes");
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118
119static int do_coredump = 1;
120SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
121 &do_coredump, 0, "Enable/Disable coredumps");
122
123/*
124 * Signal properties and actions.
125 * The array below categorizes the signals and their default actions
126 * according to the following properties:
127 */
128#define SA_KILL 0x01 /* terminates process by default */
129#define SA_CORE 0x02 /* ditto and coredumps */
130#define SA_STOP 0x04 /* suspend process */
131#define SA_TTYSTOP 0x08 /* ditto, from tty */
132#define SA_IGNORE 0x10 /* ignore by default */
133#define SA_CONT 0x20 /* continue if suspended */
134#define SA_CANTMASK 0x40 /* non-maskable, catchable */
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135#define SA_CKPT 0x80 /* checkpoint process */
136
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137
138static int sigproptbl[NSIG] = {
139 SA_KILL, /* SIGHUP */
140 SA_KILL, /* SIGINT */
141 SA_KILL|SA_CORE, /* SIGQUIT */
142 SA_KILL|SA_CORE, /* SIGILL */
143 SA_KILL|SA_CORE, /* SIGTRAP */
144 SA_KILL|SA_CORE, /* SIGABRT */
145 SA_KILL|SA_CORE, /* SIGEMT */
146 SA_KILL|SA_CORE, /* SIGFPE */
147 SA_KILL, /* SIGKILL */
148 SA_KILL|SA_CORE, /* SIGBUS */
149 SA_KILL|SA_CORE, /* SIGSEGV */
150 SA_KILL|SA_CORE, /* SIGSYS */
151 SA_KILL, /* SIGPIPE */
152 SA_KILL, /* SIGALRM */
153 SA_KILL, /* SIGTERM */
154 SA_IGNORE, /* SIGURG */
155 SA_STOP, /* SIGSTOP */
156 SA_STOP|SA_TTYSTOP, /* SIGTSTP */
157 SA_IGNORE|SA_CONT, /* SIGCONT */
158 SA_IGNORE, /* SIGCHLD */
159 SA_STOP|SA_TTYSTOP, /* SIGTTIN */
160 SA_STOP|SA_TTYSTOP, /* SIGTTOU */
161 SA_IGNORE, /* SIGIO */
162 SA_KILL, /* SIGXCPU */
163 SA_KILL, /* SIGXFSZ */
164 SA_KILL, /* SIGVTALRM */
165 SA_KILL, /* SIGPROF */
166 SA_IGNORE, /* SIGWINCH */
167 SA_IGNORE, /* SIGINFO */
168 SA_KILL, /* SIGUSR1 */
169 SA_KILL, /* SIGUSR2 */
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170 SA_IGNORE, /* SIGTHR */
171 SA_CKPT, /* SIGCKPT */
172 SA_KILL|SA_CKPT, /* SIGCKPTEXIT */
173 SA_IGNORE,
174 SA_IGNORE,
175 SA_IGNORE,
176 SA_IGNORE,
177 SA_IGNORE,
178 SA_IGNORE,
179 SA_IGNORE,
180 SA_IGNORE,
181 SA_IGNORE,
182 SA_IGNORE,
183 SA_IGNORE,
184 SA_IGNORE,
185 SA_IGNORE,
186 SA_IGNORE,
187 SA_IGNORE,
188 SA_IGNORE,
189 SA_IGNORE,
190 SA_IGNORE,
191 SA_IGNORE,
192 SA_IGNORE,
193 SA_IGNORE,
194 SA_IGNORE,
195 SA_IGNORE,
196 SA_IGNORE,
197 SA_IGNORE,
198 SA_IGNORE,
199 SA_IGNORE,
200 SA_IGNORE,
201 SA_IGNORE,
202 SA_IGNORE,
203
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204};
205
206static __inline int
207sigprop(int sig)
208{
209
210 if (sig > 0 && sig < NSIG)
211 return (sigproptbl[_SIG_IDX(sig)]);
212 return (0);
213}
214
215static __inline int
216sig_ffs(sigset_t *set)
217{
218 int i;
219
220 for (i = 0; i < _SIG_WORDS; i++)
221 if (set->__bits[i])
222 return (ffs(set->__bits[i]) + (i * 32));
223 return (0);
224}
225
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DRJ
226int
227kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact)
984263bc 228{
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DRJ
229 struct thread *td = curthread;
230 struct proc *p = td->td_proc;
41c20dac 231 struct sigacts *ps = p->p_sigacts;
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232
233 if (sig <= 0 || sig > _SIG_MAXSIG)
234 return (EINVAL);
235
236 if (oact) {
237 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
238 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
239 oact->sa_flags = 0;
240 if (SIGISMEMBER(ps->ps_sigonstack, sig))
241 oact->sa_flags |= SA_ONSTACK;
242 if (!SIGISMEMBER(ps->ps_sigintr, sig))
243 oact->sa_flags |= SA_RESTART;
244 if (SIGISMEMBER(ps->ps_sigreset, sig))
245 oact->sa_flags |= SA_RESETHAND;
246 if (SIGISMEMBER(ps->ps_signodefer, sig))
247 oact->sa_flags |= SA_NODEFER;
248 if (SIGISMEMBER(ps->ps_siginfo, sig))
249 oact->sa_flags |= SA_SIGINFO;
250 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDSTOP)
251 oact->sa_flags |= SA_NOCLDSTOP;
252 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDWAIT)
253 oact->sa_flags |= SA_NOCLDWAIT;
254 }
255 if (act) {
256 if ((sig == SIGKILL || sig == SIGSTOP) &&
257 act->sa_handler != SIG_DFL)
258 return (EINVAL);
259
260 /*
261 * Change setting atomically.
262 */
e43a034f 263 crit_enter();
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264
265 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
266 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
267 if (act->sa_flags & SA_SIGINFO) {
268 ps->ps_sigact[_SIG_IDX(sig)] =
269 (__sighandler_t *)act->sa_sigaction;
270 SIGADDSET(ps->ps_siginfo, sig);
271 } else {
272 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
273 SIGDELSET(ps->ps_siginfo, sig);
274 }
275 if (!(act->sa_flags & SA_RESTART))
276 SIGADDSET(ps->ps_sigintr, sig);
277 else
278 SIGDELSET(ps->ps_sigintr, sig);
279 if (act->sa_flags & SA_ONSTACK)
280 SIGADDSET(ps->ps_sigonstack, sig);
281 else
282 SIGDELSET(ps->ps_sigonstack, sig);
283 if (act->sa_flags & SA_RESETHAND)
284 SIGADDSET(ps->ps_sigreset, sig);
285 else
286 SIGDELSET(ps->ps_sigreset, sig);
287 if (act->sa_flags & SA_NODEFER)
288 SIGADDSET(ps->ps_signodefer, sig);
289 else
290 SIGDELSET(ps->ps_signodefer, sig);
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291 if (sig == SIGCHLD) {
292 if (act->sa_flags & SA_NOCLDSTOP)
293 p->p_procsig->ps_flag |= PS_NOCLDSTOP;
294 else
295 p->p_procsig->ps_flag &= ~PS_NOCLDSTOP;
296 if (act->sa_flags & SA_NOCLDWAIT) {
297 /*
298 * Paranoia: since SA_NOCLDWAIT is implemented
299 * by reparenting the dying child to PID 1 (and
300 * trust it to reap the zombie), PID 1 itself
301 * is forbidden to set SA_NOCLDWAIT.
302 */
303 if (p->p_pid == 1)
304 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT;
305 else
306 p->p_procsig->ps_flag |= PS_NOCLDWAIT;
8ebcad3f 307 } else {
984263bc 308 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT;
8ebcad3f 309 }
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310 }
311 /*
312 * Set bit in p_sigignore for signals that are set to SIG_IGN,
313 * and for signals set to SIG_DFL where the default is to
314 * ignore. However, don't put SIGCONT in p_sigignore, as we
315 * have to restart the process.
316 */
317 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
318 (sigprop(sig) & SA_IGNORE &&
319 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
320 /* never to be seen again */
321 SIGDELSET(p->p_siglist, sig);
322 if (sig != SIGCONT)
323 /* easier in psignal */
324 SIGADDSET(p->p_sigignore, sig);
325 SIGDELSET(p->p_sigcatch, sig);
326 } else {
327 SIGDELSET(p->p_sigignore, sig);
328 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
329 SIGDELSET(p->p_sigcatch, sig);
330 else
331 SIGADDSET(p->p_sigcatch, sig);
332 }
984263bc 333
e43a034f 334 crit_exit();
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335 }
336 return (0);
337}
338
984263bc 339int
41c20dac 340sigaction(struct sigaction_args *uap)
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341{
342 struct sigaction act, oact;
1fd87d54 343 struct sigaction *actp, *oactp;
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344 int error;
345
346 actp = (uap->act != NULL) ? &act : NULL;
347 oactp = (uap->oact != NULL) ? &oact : NULL;
348 if (actp) {
349 error = copyin(uap->act, actp, sizeof(act));
350 if (error)
351 return (error);
352 }
65957d54 353 error = kern_sigaction(uap->sig, actp, oactp);
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354 if (oactp && !error) {
355 error = copyout(oactp, uap->oact, sizeof(oact));
356 }
357 return (error);
358}
359
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360/*
361 * Initialize signal state for process 0;
362 * set to ignore signals that are ignored by default.
363 */
364void
8ebcad3f 365siginit(struct proc *p)
984263bc 366{
1fd87d54 367 int i;
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368
369 for (i = 1; i <= NSIG; i++)
370 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
371 SIGADDSET(p->p_sigignore, i);
372}
373
374/*
375 * Reset signals for an exec of the specified process.
376 */
377void
8ebcad3f 378execsigs(struct proc *p)
984263bc 379{
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380 struct sigacts *ps = p->p_sigacts;
381 int sig;
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382
383 /*
384 * Reset caught signals. Held signals remain held
385 * through p_sigmask (unless they were caught,
386 * and are now ignored by default).
387 */
388 while (SIGNOTEMPTY(p->p_sigcatch)) {
389 sig = sig_ffs(&p->p_sigcatch);
390 SIGDELSET(p->p_sigcatch, sig);
391 if (sigprop(sig) & SA_IGNORE) {
392 if (sig != SIGCONT)
393 SIGADDSET(p->p_sigignore, sig);
394 SIGDELSET(p->p_siglist, sig);
395 }
396 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
397 }
398 /*
399 * Reset stack state to the user stack.
400 * Clear set of signals caught on the signal stack.
401 */
402 p->p_sigstk.ss_flags = SS_DISABLE;
403 p->p_sigstk.ss_size = 0;
404 p->p_sigstk.ss_sp = 0;
405 p->p_flag &= ~P_ALTSTACK;
406 /*
407 * Reset no zombies if child dies flag as Solaris does.
408 */
409 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT;
410}
411
412/*
65957d54 413 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
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414 *
415 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
e43a034f 416 * p == curproc.
984263bc 417 */
65957d54
DRJ
418int
419kern_sigprocmask(int how, sigset_t *set, sigset_t *oset)
984263bc 420{
65957d54
DRJ
421 struct thread *td = curthread;
422 struct proc *p = td->td_proc;
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423 int error;
424
425 if (oset != NULL)
426 *oset = p->p_sigmask;
427
428 error = 0;
429 if (set != NULL) {
430 switch (how) {
431 case SIG_BLOCK:
432 SIG_CANTMASK(*set);
433 SIGSETOR(p->p_sigmask, *set);
434 break;
435 case SIG_UNBLOCK:
436 SIGSETNAND(p->p_sigmask, *set);
437 break;
438 case SIG_SETMASK:
439 SIG_CANTMASK(*set);
65957d54 440 p->p_sigmask = *set;
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441 break;
442 default:
443 error = EINVAL;
444 break;
445 }
446 }
447 return (error);
448}
449
450/*
451 * sigprocmask() - MP SAFE
452 */
984263bc 453int
41c20dac 454sigprocmask(struct sigprocmask_args *uap)
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MD
455{
456 sigset_t set, oset;
457 sigset_t *setp, *osetp;
458 int error;
459
460 setp = (uap->set != NULL) ? &set : NULL;
461 osetp = (uap->oset != NULL) ? &oset : NULL;
462 if (setp) {
463 error = copyin(uap->set, setp, sizeof(set));
464 if (error)
465 return (error);
466 }
65957d54 467 error = kern_sigprocmask(uap->how, setp, osetp);
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468 if (osetp && !error) {
469 error = copyout(osetp, uap->oset, sizeof(oset));
470 }
471 return (error);
472}
473
984263bc 474int
65957d54 475kern_sigpending(struct __sigset *set)
984263bc 476{
65957d54
DRJ
477 struct thread *td = curthread;
478 struct proc *p = td->td_proc;
984263bc 479
65957d54 480 *set = p->p_siglist;
984263bc 481
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482 return (0);
483}
484
984263bc 485int
65957d54 486sigpending(struct sigpending_args *uap)
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487{
488 sigset_t set;
65957d54 489 int error;
984263bc 490
65957d54 491 error = kern_sigpending(&set);
984263bc 492
65957d54
DRJ
493 if (error == 0)
494 error = copyout(&set, uap->set, sizeof(set));
495 return (error);
984263bc 496}
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497
498/*
499 * Suspend process until signal, providing mask to be set
65957d54 500 * in the meantime.
984263bc 501 */
984263bc 502int
65957d54 503kern_sigsuspend(struct __sigset *set)
984263bc 504{
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DRJ
505 struct thread *td = curthread;
506 struct proc *p = td->td_proc;
41c20dac 507 struct sigacts *ps = p->p_sigacts;
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508
509 /*
510 * When returning from sigsuspend, we want
511 * the old mask to be restored after the
512 * signal handler has finished. Thus, we
513 * save it here and mark the sigacts structure
514 * to indicate this.
515 */
516 p->p_oldsigmask = p->p_sigmask;
517 p->p_flag |= P_OLDMASK;
518
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DRJ
519 SIG_CANTMASK(*set);
520 p->p_sigmask = *set;
521 while (tsleep(ps, PCATCH, "pause", 0) == 0)
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522 /* void */;
523 /* always return EINTR rather than ERESTART... */
524 return (EINTR);
525}
526
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DRJ
527/*
528 * Note nonstandard calling convention: libc stub passes mask, not
529 * pointer, to save a copyin.
530 */
984263bc 531int
65957d54 532sigsuspend(struct sigsuspend_args *uap)
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533{
534 sigset_t mask;
65957d54 535 int error;
984263bc 536
65957d54
DRJ
537 error = copyin(uap->sigmask, &mask, sizeof(mask));
538 if (error)
539 return (error);
540
541 error = kern_sigsuspend(&mask);
542
543 return (error);
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544}
545
984263bc 546int
65957d54 547kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss)
984263bc 548{
65957d54
DRJ
549 struct thread *td = curthread;
550 struct proc *p = td->td_proc;
984263bc 551
65957d54
DRJ
552 if ((p->p_flag & P_ALTSTACK) == 0)
553 p->p_sigstk.ss_flags |= SS_DISABLE;
554
555 if (oss)
556 *oss = p->p_sigstk;
557
558 if (ss) {
559 if (ss->ss_flags & SS_DISABLE) {
560 if (p->p_sigstk.ss_flags & SS_ONSTACK)
561 return (EINVAL);
562 p->p_flag &= ~P_ALTSTACK;
563 p->p_sigstk.ss_flags = ss->ss_flags;
564 } else {
565 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
566 return (ENOMEM);
567 p->p_flag |= P_ALTSTACK;
568 p->p_sigstk = *ss;
569 }
984263bc 570 }
65957d54
DRJ
571
572 return (0);
984263bc 573}
984263bc 574
984263bc 575int
41c20dac 576sigaltstack(struct sigaltstack_args *uap)
984263bc 577{
65957d54 578 stack_t ss, oss;
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579 int error;
580
65957d54
DRJ
581 if (uap->ss) {
582 error = copyin(uap->ss, &ss, sizeof(ss));
583 if (error)
584 return (error);
984263bc 585 }
65957d54
DRJ
586
587 error = kern_sigaltstack(uap->ss ? &ss : NULL,
588 uap->oss ? &oss : NULL);
589
590 if (error == 0 && uap->oss)
591 error = copyout(&oss, uap->oss, sizeof(*uap->oss));
592 return (error);
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593}
594
595/*
596 * Common code for kill process group/broadcast kill.
597 * cp is calling process.
598 */
65957d54
DRJ
599static int
600killpg(int sig, int pgid, int all)
984263bc 601{
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602 struct proc *cp = curproc;
603 struct proc *p;
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604 struct pgrp *pgrp;
605 int nfound = 0;
606
8ebcad3f 607 if (all) {
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608 /*
609 * broadcast
610 */
f62004ad 611 FOREACH_PROC_IN_SYSTEM(p) {
984263bc 612 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
41c20dac 613 p == cp || !CANSIGNAL(p, sig))
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614 continue;
615 nfound++;
616 if (sig)
617 psignal(p, sig);
618 }
8ebcad3f
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619 } else {
620 if (pgid == 0) {
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621 /*
622 * zero pgid means send to my process group.
623 */
624 pgrp = cp->p_pgrp;
8ebcad3f 625 } else {
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626 pgrp = pgfind(pgid);
627 if (pgrp == NULL)
628 return (ESRCH);
629 }
630 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
631 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
632 p->p_stat == SZOMB ||
41c20dac 633 !CANSIGNAL(p, sig))
984263bc
MD
634 continue;
635 nfound++;
636 if (sig)
637 psignal(p, sig);
638 }
639 }
640 return (nfound ? 0 : ESRCH);
641}
642
984263bc 643int
65957d54 644kern_kill(int sig, int pid)
984263bc 645{
65957d54
DRJ
646 struct thread *td = curthread;
647 struct proc *p = td->td_proc;
984263bc 648
65957d54 649 if ((u_int)sig > _SIG_MAXSIG)
984263bc 650 return (EINVAL);
65957d54 651 if (pid > 0) {
984263bc 652 /* kill single process */
65957d54 653 if ((p = pfind(pid)) == NULL)
984263bc 654 return (ESRCH);
65957d54 655 if (!CANSIGNAL(p, sig))
984263bc 656 return (EPERM);
65957d54
DRJ
657 if (sig)
658 psignal(p, sig);
984263bc
MD
659 return (0);
660 }
65957d54 661 switch (pid) {
984263bc 662 case -1: /* broadcast signal */
65957d54 663 return (killpg(sig, 0, 1));
984263bc 664 case 0: /* signal own process group */
65957d54 665 return (killpg(sig, 0, 0));
984263bc 666 default: /* negative explicit process group */
65957d54 667 return (killpg(sig, -pid, 0));
984263bc
MD
668 }
669 /* NOTREACHED */
670}
671
984263bc 672int
65957d54 673kill(struct kill_args *uap)
984263bc 674{
65957d54
DRJ
675 int error;
676
677 error = kern_kill(uap->signum, uap->pid);
678
679 return (error);
984263bc 680}
984263bc
MD
681
682/*
683 * Send a signal to a process group.
684 */
685void
41c20dac 686gsignal(int pgid, int sig)
984263bc
MD
687{
688 struct pgrp *pgrp;
689
690 if (pgid && (pgrp = pgfind(pgid)))
691 pgsignal(pgrp, sig, 0);
692}
693
694/*
695 * Send a signal to a process group. If checktty is 1,
696 * limit to members which have a controlling terminal.
697 */
698void
8ebcad3f 699pgsignal(struct pgrp *pgrp, int sig, int checkctty)
984263bc 700{
1fd87d54 701 struct proc *p;
984263bc
MD
702
703 if (pgrp)
704 LIST_FOREACH(p, &pgrp->pg_members, p_pglist)
705 if (checkctty == 0 || p->p_flag & P_CONTROLT)
706 psignal(p, sig);
707}
708
709/*
710 * Send a signal caused by a trap to the current process.
711 * If it will be caught immediately, deliver it with correct code.
712 * Otherwise, post it normally.
713 */
714void
8ebcad3f 715trapsignal(struct proc *p, int sig, u_long code)
984263bc 716{
dadab5e9 717 struct sigacts *ps = p->p_sigacts;
984263bc
MD
718
719 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
720 !SIGISMEMBER(p->p_sigmask, sig)) {
721 p->p_stats->p_ru.ru_nsignals++;
722#ifdef KTRACE
dadab5e9 723 if (KTRPOINT(p->p_thread, KTR_PSIG))
984263bc
MD
724 ktrpsig(p->p_tracep, sig, ps->ps_sigact[_SIG_IDX(sig)],
725 &p->p_sigmask, code);
726#endif
727 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
728 &p->p_sigmask, code);
729 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
730 if (!SIGISMEMBER(ps->ps_signodefer, sig))
731 SIGADDSET(p->p_sigmask, sig);
732 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
733 /*
65957d54 734 * See kern_sigaction() for origin of this code.
984263bc
MD
735 */
736 SIGDELSET(p->p_sigcatch, sig);
737 if (sig != SIGCONT &&
738 sigprop(sig) & SA_IGNORE)
739 SIGADDSET(p->p_sigignore, sig);
740 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
741 }
742 } else {
743 p->p_code = code; /* XXX for core dump/debugger */
744 p->p_sig = sig; /* XXX to verify code */
745 psignal(p, sig);
746 }
747}
748
749/*
750 * Send the signal to the process. If the signal has an action, the action
751 * is usually performed by the target process rather than the caller; we add
752 * the signal to the set of pending signals for the process.
753 *
754 * Exceptions:
755 * o When a stop signal is sent to a sleeping process that takes the
756 * default action, the process is stopped without awakening it.
757 * o SIGCONT restarts stopped processes (or puts them back to sleep)
758 * regardless of the signal action (eg, blocked or ignored).
759 *
760 * Other ignored signals are discarded immediately.
761 */
762void
8ebcad3f 763psignal(struct proc *p, int sig)
984263bc 764{
553ea3c8 765 struct lwp *lp = &p->p_lwp;
e43a034f 766 int prop;
cb973d15 767 sig_t action;
984263bc
MD
768
769 if (sig > _SIG_MAXSIG || sig <= 0) {
770 printf("psignal: signal %d\n", sig);
771 panic("psignal signal number");
772 }
773
e43a034f 774 crit_enter();
984263bc 775 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
e43a034f 776 crit_exit();
984263bc
MD
777
778 prop = sigprop(sig);
779
780 /*
781 * If proc is traced, always give parent a chance;
782 * if signal event is tracked by procfs, give *that*
783 * a chance, as well.
784 */
8ebcad3f 785 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) {
984263bc 786 action = SIG_DFL;
8ebcad3f 787 } else {
984263bc
MD
788 /*
789 * If the signal is being ignored,
790 * then we forget about it immediately.
791 * (Note: we don't set SIGCONT in p_sigignore,
792 * and if it is set to SIG_IGN,
793 * action will be SIG_DFL here.)
794 */
795 if (SIGISMEMBER(p->p_sigignore, sig) || (p->p_flag & P_WEXIT))
796 return;
797 if (SIGISMEMBER(p->p_sigmask, sig))
798 action = SIG_HOLD;
799 else if (SIGISMEMBER(p->p_sigcatch, sig))
800 action = SIG_CATCH;
801 else
802 action = SIG_DFL;
803 }
804
805 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
8ebcad3f 806 (p->p_flag & P_TRACED) == 0) {
984263bc 807 p->p_nice = NZERO;
8ebcad3f 808 }
984263bc 809
344ad853
MD
810 /*
811 * If continuing, clear any pending STOP signals.
812 */
984263bc
MD
813 if (prop & SA_CONT)
814 SIG_STOPSIGMASK(p->p_siglist);
9d63d5c0 815
984263bc
MD
816 if (prop & SA_STOP) {
817 /*
818 * If sending a tty stop signal to a member of an orphaned
819 * process group, discard the signal here if the action
820 * is default; don't stop the process below if sleeping,
821 * and don't clear any pending SIGCONT.
822 */
823 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
8ebcad3f 824 action == SIG_DFL) {
984263bc 825 return;
8ebcad3f 826 }
984263bc
MD
827 SIG_CONTSIGMASK(p->p_siglist);
828 }
829 SIGADDSET(p->p_siglist, sig);
830
831 /*
832 * Defer further processing for signals which are held,
833 * except that stopped processes must be continued by SIGCONT.
834 */
344ad853
MD
835 if (action == SIG_HOLD) {
836 if ((prop & SA_CONT) == 0 || (p->p_flag & P_STOPPED) == 0)
837 return;
838 }
e43a034f
MD
839
840 crit_enter();
841
344ad853
MD
842 /*
843 * Process is in tsleep and not stopped
844 */
845 if (p->p_stat == SSLEEP && (p->p_flag & P_STOPPED) == 0) {
984263bc 846 /*
344ad853 847 * If the process is sleeping uninterruptibly
984263bc
MD
848 * we can't interrupt the sleep... the signal will
849 * be noticed when the process returns through
850 * trap() or syscall().
851 */
852 if ((p->p_flag & P_SINTR) == 0)
853 goto out;
344ad853 854
984263bc 855 /*
344ad853 856 * If the process is sleeping and traced, make it runnable
984263bc
MD
857 * so it can discover the signal in issignal() and stop
858 * for the parent.
344ad853
MD
859 *
860 * If the process is stopped and traced, no further action
861 * is necessary.
984263bc
MD
862 */
863 if (p->p_flag & P_TRACED)
864 goto run;
344ad853 865
984263bc 866 /*
344ad853
MD
867 * If the process is sleeping and SA_CONT, and the signal
868 * mode is SIG_DFL, then make the process runnable.
869 *
870 * However, do *NOT* set P_BREAKTSLEEP. We do not want
871 * a SIGCONT to terminate an interruptable tsleep early
872 * and generate a spurious EINTR.
984263bc
MD
873 */
874 if ((prop & SA_CONT) && action == SIG_DFL) {
875 SIGDELSET(p->p_siglist, sig);
344ad853 876 goto run_no_break;
984263bc 877 }
344ad853 878
984263bc 879 /*
344ad853
MD
880 * If the process is sleeping and receives a STOP signal,
881 * process immediately if possible. All other (caught or
882 * default) signals cause the process to run.
984263bc
MD
883 */
884 if (prop & SA_STOP) {
885 if (action != SIG_DFL)
26a0694b 886 goto run;
344ad853 887
984263bc 888 /*
344ad853
MD
889 * If a child holding parent blocked, stopping
890 * could cause deadlock. Take no action at this
891 * time.
984263bc
MD
892 */
893 if (p->p_flag & P_PPWAIT)
894 goto out;
344ad853
MD
895
896 /*
897 * Do not actually try to manipulate the process
898 * while it is sleeping, simply set P_STOPPED to
899 * indicate that it should stop as soon as it safely
900 * can.
901 */
984263bc 902 SIGDELSET(p->p_siglist, sig);
344ad853
MD
903 p->p_flag |= P_STOPPED;
904 p->p_flag &= ~P_WAITED;
984263bc
MD
905 p->p_xstat = sig;
906 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0)
907 psignal(p->p_pptr, SIGCHLD);
984263bc 908 goto out;
8ebcad3f 909 }
344ad853 910
984263bc 911 /*
344ad853
MD
912 * Otherwise the signal can interrupt the sleep.
913 */
914 goto run;
915 }
916
917 /*
918 * Process is in tsleep and is stopped
919 */
920 if (p->p_stat == SSLEEP && (p->p_flag & P_STOPPED)) {
921 /*
922 * If the process is stopped and is being traced, then no
923 * further action is necessary.
984263bc
MD
924 */
925 if (p->p_flag & P_TRACED)
926 goto out;
927
928 /*
344ad853
MD
929 * If the process is stopped and receives a KILL signal,
930 * make the process runnable.
984263bc
MD
931 */
932 if (sig == SIGKILL)
26a0694b 933 goto run;
984263bc 934
344ad853
MD
935 /*
936 * If the process is stopped and receives a CONT signal,
937 * then try to make the process runnable again.
938 */
984263bc
MD
939 if (prop & SA_CONT) {
940 /*
941 * If SIGCONT is default (or ignored), we continue the
942 * process but don't leave the signal in p_siglist, as
943 * it has no further action. If SIGCONT is held, we
944 * continue the process and leave the signal in
945 * p_siglist. If the process catches SIGCONT, let it
344ad853 946 * handle the signal itself.
984263bc
MD
947 */
948 if (action == SIG_DFL)
949 SIGDELSET(p->p_siglist, sig);
950 if (action == SIG_CATCH)
26a0694b 951 goto run;
984263bc 952
984263bc 953 /*
344ad853
MD
954 * Make runnable but do not break a tsleep unless
955 * some other signal was pending.
984263bc 956 */
344ad853
MD
957 goto run_no_break;
958 }
959
960 /*
961 * If the process is stopped and receives another STOP
962 * signal, we do not need to stop it again. If we did
963 * the shell could get confused.
964 */
965 if (prop & SA_STOP) {
984263bc
MD
966 SIGDELSET(p->p_siglist, sig);
967 goto out;
968 }
969
970 /*
344ad853
MD
971 * Otherwise the process is sleeping interruptably but
972 * is stopped, just set the P_BREAKTSLEEP flag and take
973 * no further action. The next runnable action will wake
974 * the process up.
984263bc 975 */
344ad853 976 p->p_flag |= P_BREAKTSLEEP;
984263bc 977 goto out;
344ad853
MD
978 }
979
980 /*
981 * Otherwise the process is running
982 *
983 * SRUN, SIDL, SZOMB do nothing with the signal,
984 * other than kicking ourselves if we are running.
985 * It will either never be noticed, or noticed very soon.
986 *
987 * Note that p_thread may be NULL or may not be completely
988 * initialized if the process is in the SIDL or SZOMB state.
989 *
990 * For SMP we may have to forward the request to another cpu.
991 * YYY the MP lock prevents the target process from moving
992 * to another cpu, see kern/kern_switch.c
993 *
994 * If the target thread is waiting on its message port,
995 * wakeup the target thread so it can check (or ignore)
996 * the new signal. YYY needs cleanup.
997 */
998 if (lp == lwkt_preempted_proc()) {
999 signotify();
1000 } else if (p->p_stat == SRUN) {
1001 struct thread *td = p->p_thread;
1002
1003 KASSERT(td != NULL,
1004 ("pid %d NULL p_thread stat %d flags %08x",
1005 p->p_pid, p->p_stat, p->p_flag));
1006
984263bc 1007#ifdef SMP
344ad853
MD
1008 if (td->td_gd != mycpu)
1009 lwkt_send_ipiq(td->td_gd, signotify_remote, lp);
1010 else
984263bc 1011#endif
344ad853
MD
1012 if (td->td_msgport.mp_flags & MSGPORTF_WAITING)
1013 lwkt_schedule(td);
984263bc 1014 }
344ad853 1015 goto out;
984263bc 1016 /*NOTREACHED*/
984263bc 1017run:
344ad853
MD
1018 /*
1019 * Make runnable and break out of any tsleep as well.
1020 */
1021 p->p_flag |= P_BREAKTSLEEP;
1022run_no_break:
984263bc
MD
1023 setrunnable(p);
1024out:
e43a034f 1025 crit_exit();
984263bc
MD
1026}
1027
cb973d15
MD
1028#ifdef SMP
1029
1030/*
1031 * This function is called via an IPI. We will be in a critical section but
1032 * the MP lock will NOT be held. Also note that by the time the ipi message
1033 * gets to us the process 'p' (arg) may no longer be scheduled or even valid.
1034 */
1035static void
1036signotify_remote(void *arg)
1037{
553ea3c8 1038 struct lwp *lp = arg;
60be1d11 1039
553ea3c8 1040 if (lp == lwkt_preempted_proc()) {
235957ed 1041 signotify();
60be1d11 1042 } else {
553ea3c8 1043 struct thread *td = lp->lwp_thread;
60be1d11
MD
1044 if (td->td_msgport.mp_flags & MSGPORTF_WAITING)
1045 lwkt_schedule(td);
1046 }
cb973d15
MD
1047}
1048
1049#endif
1050
3a59f0f7
DX
1051static int
1052kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout)
1053{
1054 sigset_t savedmask, set;
1055 struct proc *p = curproc;
1056 int error, sig, hz, timevalid = 0;
1057 struct timespec rts, ets, ts;
1058 struct timeval tv;
1059
1060 error = 0;
1061 sig = 0;
1062 SIG_CANTMASK(waitset);
1063 savedmask = p->p_sigmask;
1064
1065 if (timeout) {
f8c41806
DX
1066 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 &&
1067 timeout->tv_nsec < 1000000000) {
3a59f0f7
DX
1068 timevalid = 1;
1069 getnanouptime(&rts);
1070 ets = rts;
1071 timespecadd(&ets, timeout);
1072 }
1073 }
1074
1075 for (;;) {
1076 set = p->p_siglist;
1077 SIGSETAND(set, waitset);
1078 if ((sig = sig_ffs(&set)) != 0) {
1079 SIGFILLSET(p->p_sigmask);
1080 SIGDELSET(p->p_sigmask, sig);
976f0bc5 1081 SIG_CANTMASK(p->p_sigmask);
3a59f0f7
DX
1082 sig = issignal(p);
1083 /*
1084 * It may be a STOP signal, in the case, issignal
1085 * returns 0, because we may stop there, and new
1086 * signal can come in, we should restart if we got
1087 * nothing.
1088 */
1089 if (sig == 0)
1090 continue;
1091 else
1092 break;
1093 }
1094
1095 /*
1096 * Previous checking got nothing, and we retried but still
1097 * got nothing, we should return the error status.
1098 */
1099 if (error)
1100 break;
1101
1102 /*
1103 * POSIX says this must be checked after looking for pending
1104 * signals.
1105 */
1106 if (timeout) {
1107 if (!timevalid) {
1108 error = EINVAL;
1109 break;
1110 }
1111 getnanouptime(&rts);
1112 if (timespeccmp(&rts, &ets, >=)) {
1113 error = EAGAIN;
1114 break;
1115 }
1116 ts = ets;
1117 timespecsub(&ts, &rts);
1118 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1119 hz = tvtohz_high(&tv);
1120 } else
1121 hz = 0;
1122
1123 p->p_sigmask = savedmask;
1124 SIGSETNAND(p->p_sigmask, waitset);
1125 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz);
1126 if (timeout) {
1127 if (error == ERESTART) {
1128 /* can not restart a timeout wait. */
1129 error = EINTR;
1130 } else if (error == EAGAIN) {
1131 /* will calculate timeout by ourself. */
1132 error = 0;
1133 }
1134 }
1135 /* Retry ... */
1136 }
1137
1138 p->p_sigmask = savedmask;
1139 if (sig) {
1140 error = 0;
1141 bzero(info, sizeof(*info));
1142 info->si_signo = sig;
1143 SIGDELSET(p->p_siglist, sig); /* take the signal! */
1144 }
1145 return (error);
1146}
1147
1148int
1149sigtimedwait(struct sigtimedwait_args *uap)
1150{
1151 struct timespec ts;
1152 struct timespec *timeout;
1153 sigset_t set;
1154 siginfo_t info;
1155 int error;
1156
1157 if (uap->timeout) {
1158 error = copyin(uap->timeout, &ts, sizeof(ts));
1159 if (error)
1160 return (error);
1161 timeout = &ts;
1162 } else {
1163 timeout = NULL;
1164 }
1165 error = copyin(uap->set, &set, sizeof(set));
1166 if (error)
1167 return (error);
1168 error = kern_sigtimedwait(set, &info, timeout);
1169 if (error)
1170 return (error);
1171 if (uap->info)
1172 error = copyout(&info, uap->info, sizeof(info));
1173 /* Repost if we got an error. */
1174 if (error)
1175 psignal(curproc, info.si_signo);
1176 else
1177 uap->sysmsg_result = info.si_signo;
1178 return (error);
1179}
1180
1181int
1182sigwaitinfo(struct sigwaitinfo_args *uap)
1183{
1184 siginfo_t info;
1185 sigset_t set;
1186 int error;
1187
1188 error = copyin(uap->set, &set, sizeof(set));
1189 if (error)
1190 return (error);
1191 error = kern_sigtimedwait(set, &info, NULL);
1192 if (error)
1193 return (error);
1194 if (uap->info)
1195 error = copyout(&info, uap->info, sizeof(info));
1196 /* Repost if we got an error. */
1197 if (error)
1198 psignal(curproc, info.si_signo);
1199 else
1200 uap->sysmsg_result = info.si_signo;
1201 return (error);
1202}
1203
a94976ad
MD
1204/*
1205 * If the current process has received a signal that would interrupt a
1206 * system call, return EINTR or ERESTART as appropriate.
1207 */
1208int
1209iscaught(struct proc *p)
1210{
1211 int sig;
1212
1213 if (p) {
1214 if ((sig = CURSIG(p)) != 0) {
1215 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1216 return (EINTR);
1217 return (ERESTART);
1218 }
1219 }
1220 return(EWOULDBLOCK);
1221}
1222
984263bc
MD
1223/*
1224 * If the current process has received a signal (should be caught or cause
1225 * termination, should interrupt current syscall), return the signal number.
1226 * Stop signals with default action are processed immediately, then cleared;
1227 * they aren't returned. This is checked after each entry to the system for
1228 * a syscall or trap (though this can usually be done without calling issignal
1229 * by checking the pending signal masks in the CURSIG macro.) The normal call
1230 * sequence is
1231 *
1232 * while (sig = CURSIG(curproc))
1233 * postsig(sig);
1234 */
1235int
8ebcad3f 1236issignal(struct proc *p)
984263bc
MD
1237{
1238 sigset_t mask;
1fd87d54 1239 int sig, prop;
984263bc
MD
1240
1241 for (;;) {
1242 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
1243
1244 mask = p->p_siglist;
1245 SIGSETNAND(mask, p->p_sigmask);
1246 if (p->p_flag & P_PPWAIT)
1247 SIG_STOPSIGMASK(mask);
1248 if (!SIGNOTEMPTY(mask)) /* no signal to send */
1249 return (0);
1250 sig = sig_ffs(&mask);
1251
1252 STOPEVENT(p, S_SIG, sig);
1253
1254 /*
1255 * We should see pending but ignored signals
1256 * only if P_TRACED was on when they were posted.
1257 */
1258 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
1259 SIGDELSET(p->p_siglist, sig);
1260 continue;
1261 }
344ad853 1262 if ((p->p_flag & P_TRACED) && (p->p_flag & P_PPWAIT) == 0) {
984263bc 1263 /*
344ad853
MD
1264 * If traced, always stop, and stay stopped until
1265 * released by the parent.
1266 *
1267 * NOTE: P_STOPPED may get cleared during the loop,
1268 * but we do not re-notify the parent if we have
1269 * to loop several times waiting for the parent
1270 * to let us continue.
984263bc
MD
1271 */
1272 p->p_xstat = sig;
344ad853
MD
1273 p->p_flag |= P_STOPPED;
1274 p->p_flag &= ~P_WAITED;
984263bc
MD
1275 psignal(p->p_pptr, SIGCHLD);
1276 do {
344ad853
MD
1277 tstop(p);
1278 } while (!trace_req(p) && (p->p_flag & P_TRACED));
1279 p->p_flag &= ~P_STOPPED;
984263bc
MD
1280
1281 /*
1282 * If parent wants us to take the signal,
1283 * then it will leave it in p->p_xstat;
1284 * otherwise we just look for signals again.
1285 */
1286 SIGDELSET(p->p_siglist, sig); /* clear old signal */
1287 sig = p->p_xstat;
1288 if (sig == 0)
1289 continue;
1290
1291 /*
1292 * Put the new signal into p_siglist. If the
1293 * signal is being masked, look for other signals.
1294 */
1295 SIGADDSET(p->p_siglist, sig);
1296 if (SIGISMEMBER(p->p_sigmask, sig))
1297 continue;
1298
1299 /*
1300 * If the traced bit got turned off, go back up
1301 * to the top to rescan signals. This ensures
1302 * that p_sig* and ps_sigact are consistent.
1303 */
1304 if ((p->p_flag & P_TRACED) == 0)
1305 continue;
1306 }
1307
1308 prop = sigprop(sig);
1309
1310 /*
1311 * Decide whether the signal should be returned.
1312 * Return the signal's number, or fall through
1313 * to clear it from the pending mask.
1314 */
1315 switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
984263bc
MD
1316 case (int)SIG_DFL:
1317 /*
1318 * Don't take default actions on system processes.
1319 */
1320 if (p->p_pid <= 1) {
1321#ifdef DIAGNOSTIC
1322 /*
1323 * Are you sure you want to ignore SIGSEGV
1324 * in init? XXX
1325 */
1326 printf("Process (pid %lu) got signal %d\n",
1327 (u_long)p->p_pid, sig);
1328#endif
1329 break; /* == ignore */
1330 }
f758a39e
MD
1331
1332 /*
1333 * Handle the in-kernel checkpoint action
1334 */
1335 if (prop & SA_CKPT) {
0ba6fbbf 1336 checkpoint_signal_handler(p);
f758a39e
MD
1337 break;
1338 }
1339
984263bc
MD
1340 /*
1341 * If there is a pending stop signal to process
1342 * with default action, stop here,
1343 * then clear the signal. However,
1344 * if process is member of an orphaned
1345 * process group, ignore tty stop signals.
1346 */
1347 if (prop & SA_STOP) {
1348 if (p->p_flag & P_TRACED ||
1349 (p->p_pgrp->pg_jobc == 0 &&
1350 prop & SA_TTYSTOP))
1351 break; /* == ignore */
1352 p->p_xstat = sig;
344ad853
MD
1353 p->p_flag |= P_STOPPED;
1354 p->p_flag &= ~P_WAITED;
1355
984263bc
MD
1356 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0)
1357 psignal(p->p_pptr, SIGCHLD);
344ad853
MD
1358 while (p->p_flag & P_STOPPED) {
1359 tstop(p);
1360 }
984263bc
MD
1361 break;
1362 } else if (prop & SA_IGNORE) {
1363 /*
1364 * Except for SIGCONT, shouldn't get here.
1365 * Default action is to ignore; drop it.
1366 */
1367 break; /* == ignore */
8ebcad3f 1368 } else {
984263bc 1369 return (sig);
8ebcad3f
MD
1370 }
1371
984263bc
MD
1372 /*NOTREACHED*/
1373
1374 case (int)SIG_IGN:
1375 /*
1376 * Masking above should prevent us ever trying
1377 * to take action on an ignored signal other
1378 * than SIGCONT, unless process is traced.
1379 */
1380 if ((prop & SA_CONT) == 0 &&
1381 (p->p_flag & P_TRACED) == 0)
1382 printf("issignal\n");
1383 break; /* == ignore */
1384
1385 default:
1386 /*
1387 * This signal has an action, let
1388 * postsig() process it.
1389 */
1390 return (sig);
1391 }
1392 SIGDELSET(p->p_siglist, sig); /* take the signal! */
1393 }
1394 /* NOTREACHED */
1395}
1396
984263bc
MD
1397/*
1398 * Take the action for the specified signal
1399 * from the current set of pending signals.
1400 */
1401void
8ebcad3f 1402postsig(int sig)
984263bc 1403{
41c20dac 1404 struct proc *p = curproc;
984263bc
MD
1405 struct sigacts *ps = p->p_sigacts;
1406 sig_t action;
1407 sigset_t returnmask;
1408 int code;
1409
1410 KASSERT(sig != 0, ("postsig"));
1411
1412 SIGDELSET(p->p_siglist, sig);
1413 action = ps->ps_sigact[_SIG_IDX(sig)];
1414#ifdef KTRACE
dadab5e9 1415 if (KTRPOINT(p->p_thread, KTR_PSIG))
984263bc
MD
1416 ktrpsig(p->p_tracep, sig, action, p->p_flag & P_OLDMASK ?
1417 &p->p_oldsigmask : &p->p_sigmask, 0);
1418#endif
1419 STOPEVENT(p, S_SIG, sig);
1420
1421 if (action == SIG_DFL) {
1422 /*
1423 * Default action, where the default is to kill
1424 * the process. (Other cases were ignored above.)
1425 */
1426 sigexit(p, sig);
1427 /* NOTREACHED */
1428 } else {
1429 /*
1430 * If we get here, the signal must be caught.
1431 */
1432 KASSERT(action != SIG_IGN && !SIGISMEMBER(p->p_sigmask, sig),
1433 ("postsig action"));
1434 /*
1435 * Set the new mask value and also defer further
1436 * occurrences of this signal.
1437 *
1438 * Special case: user has done a sigsuspend. Here the
1439 * current mask is not of interest, but rather the
1440 * mask from before the sigsuspend is what we want
1441 * restored after the signal processing is completed.
1442 */
e43a034f 1443 crit_enter();
984263bc
MD
1444 if (p->p_flag & P_OLDMASK) {
1445 returnmask = p->p_oldsigmask;
1446 p->p_flag &= ~P_OLDMASK;
8ebcad3f 1447 } else {
984263bc 1448 returnmask = p->p_sigmask;
8ebcad3f 1449 }
984263bc
MD
1450
1451 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
1452 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1453 SIGADDSET(p->p_sigmask, sig);
1454
1455 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
1456 /*
65957d54 1457 * See kern_sigaction() for origin of this code.
984263bc
MD
1458 */
1459 SIGDELSET(p->p_sigcatch, sig);
1460 if (sig != SIGCONT &&
1461 sigprop(sig) & SA_IGNORE)
1462 SIGADDSET(p->p_sigignore, sig);
1463 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1464 }
e43a034f 1465 crit_exit();
984263bc
MD
1466 p->p_stats->p_ru.ru_nsignals++;
1467 if (p->p_sig != sig) {
1468 code = 0;
1469 } else {
1470 code = p->p_code;
1471 p->p_code = 0;
1472 p->p_sig = 0;
1473 }
1474 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
1475 }
1476}
1477
1478/*
1479 * Kill the current process for stated reason.
1480 */
1481void
8ebcad3f 1482killproc(struct proc *p, char *why)
984263bc
MD
1483{
1484 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm,
41c20dac 1485 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
984263bc
MD
1486 psignal(p, SIGKILL);
1487}
1488
1489/*
1490 * Force the current process to exit with the specified signal, dumping core
1491 * if appropriate. We bypass the normal tests for masked and caught signals,
1492 * allowing unrecoverable failures to terminate the process without changing
1493 * signal state. Mark the accounting record with the signal termination.
1494 * If dumping core, save the signal number for the debugger. Calls exit and
1495 * does not return.
1496 */
1497void
41c20dac 1498sigexit(struct proc *p, int sig)
984263bc 1499{
984263bc
MD
1500 p->p_acflag |= AXSIG;
1501 if (sigprop(sig) & SA_CORE) {
1502 p->p_sig = sig;
1503 /*
1504 * Log signals which would cause core dumps
1505 * (Log as LOG_INFO to appease those who don't want
1506 * these messages.)
1507 * XXX : Todo, as well as euid, write out ruid too
1508 */
1509 if (coredump(p) == 0)
1510 sig |= WCOREFLAG;
1511 if (kern_logsigexit)
1512 log(LOG_INFO,
1513 "pid %d (%s), uid %d: exited on signal %d%s\n",
1514 p->p_pid, p->p_comm,
41c20dac 1515 p->p_ucred ? p->p_ucred->cr_uid : -1,
984263bc
MD
1516 sig &~ WCOREFLAG,
1517 sig & WCOREFLAG ? " (core dumped)" : "");
1518 }
41c20dac 1519 exit1(W_EXITCODE(0, sig));
984263bc
MD
1520 /* NOTREACHED */
1521}
1522
1523static char corefilename[MAXPATHLEN+1] = {"%N.core"};
1524SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
1525 sizeof(corefilename), "process corefile name format string");
1526
1527/*
1528 * expand_name(name, uid, pid)
1529 * Expand the name described in corefilename, using name, uid, and pid.
1530 * corefilename is a printf-like string, with three format specifiers:
1531 * %N name of process ("name")
1532 * %P process id (pid)
1533 * %U user id (uid)
1534 * For example, "%N.core" is the default; they can be disabled completely
1535 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
1536 * This is controlled by the sysctl variable kern.corefile (see above).
1537 */
1538
1539static char *
8ebcad3f
MD
1540expand_name(const char *name, uid_t uid, pid_t pid)
1541{
984263bc
MD
1542 char *temp;
1543 char buf[11]; /* Buffer for pid/uid -- max 4B */
1544 int i, n;
1545 char *format = corefilename;
1546 size_t namelen;
1547
1548 temp = malloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
1549 if (temp == NULL)
1550 return NULL;
1551 namelen = strlen(name);
1552 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
1553 int l;
1554 switch (format[i]) {
1555 case '%': /* Format character */
1556 i++;
1557 switch (format[i]) {
1558 case '%':
1559 temp[n++] = '%';
1560 break;
1561 case 'N': /* process name */
1562 if ((n + namelen) > MAXPATHLEN) {
1563 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1564 pid, name, uid, temp, name);
1565 free(temp, M_TEMP);
1566 return NULL;
1567 }
1568 memcpy(temp+n, name, namelen);
1569 n += namelen;
1570 break;
1571 case 'P': /* process id */
1572 l = sprintf(buf, "%u", pid);
1573 if ((n + l) > MAXPATHLEN) {
1574 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1575 pid, name, uid, temp, name);
1576 free(temp, M_TEMP);
1577 return NULL;
1578 }
1579 memcpy(temp+n, buf, l);
1580 n += l;
1581 break;
1582 case 'U': /* user id */
1583 l = sprintf(buf, "%u", uid);
1584 if ((n + l) > MAXPATHLEN) {
1585 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1586 pid, name, uid, temp, name);
1587 free(temp, M_TEMP);
1588 return NULL;
1589 }
1590 memcpy(temp+n, buf, l);
1591 n += l;
1592 break;
1593 default:
1594 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
1595 }
1596 break;
1597 default:
1598 temp[n++] = format[i];
1599 }
1600 }
1601 temp[n] = '\0';
1602 return temp;
1603}
1604
1605/*
1606 * Dump a process' core. The main routine does some
1607 * policy checking, and creates the name of the coredump;
1608 * then it passes on a vnode and a size limit to the process-specific
1609 * coredump routine if there is one; if there _is not_ one, it returns
1610 * ENOSYS; otherwise it returns the error from the process-specific routine.
1611 */
1612
1613static int
dadab5e9 1614coredump(struct proc *p)
984263bc 1615{
dadab5e9
MD
1616 struct vnode *vp;
1617 struct ucred *cred = p->p_ucred;
1618 struct thread *td = p->p_thread;
984263bc 1619 struct flock lf;
fad57d0e 1620 struct nlookupdata nd;
984263bc
MD
1621 struct vattr vattr;
1622 int error, error1;
1623 char *name; /* name of corefile */
1624 off_t limit;
1625
1626 STOPEVENT(p, S_CORE, 0);
1627
1628 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0)
1629 return (EFAULT);
1630
1631 /*
1632 * Note that the bulk of limit checking is done after
1633 * the corefile is created. The exception is if the limit
1634 * for corefiles is 0, in which case we don't bother
1635 * creating the corefile at all. This layout means that
1636 * a corefile is truncated instead of not being created,
1637 * if it is larger than the limit.
1638 */
1639 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
1640 if (limit == 0)
50fd5388 1641 return EFBIG;
984263bc
MD
1642
1643 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
1644 if (name == NULL)
1645 return (EINVAL);
fad57d0e
MD
1646 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
1647 if (error == 0)
1648 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
984263bc 1649 free(name, M_TEMP);
fad57d0e
MD
1650 if (error) {
1651 nlookup_done(&nd);
984263bc 1652 return (error);
fad57d0e
MD
1653 }
1654 vp = nd.nl_open_vp;
1655 nd.nl_open_vp = NULL;
1656 nlookup_done(&nd);
984263bc 1657
5fd012e0 1658 VOP_UNLOCK(vp, 0, td);
984263bc
MD
1659 lf.l_whence = SEEK_SET;
1660 lf.l_start = 0;
1661 lf.l_len = 0;
1662 lf.l_type = F_WRLCK;
1663 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK);
1664 if (error)
1665 goto out2;
1666
1667 /* Don't dump to non-regular files or files with links. */
1668 if (vp->v_type != VREG ||
3b568787 1669 VOP_GETATTR(vp, &vattr, td) || vattr.va_nlink != 1) {
984263bc
MD
1670 error = EFAULT;
1671 goto out1;
1672 }
1673
1674 VATTR_NULL(&vattr);
5fd012e0 1675 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
984263bc 1676 vattr.va_size = 0;
dadab5e9
MD
1677 VOP_LEASE(vp, td, cred, LEASE_WRITE);
1678 VOP_SETATTR(vp, &vattr, cred, td);
984263bc 1679 p->p_acflag |= ACORE;
5fd012e0 1680 VOP_UNLOCK(vp, 0, td);
984263bc
MD
1681
1682 error = p->p_sysent->sv_coredump ?
fad57d0e 1683 p->p_sysent->sv_coredump(p, vp, limit) : ENOSYS;
984263bc
MD
1684
1685out1:
1686 lf.l_type = F_UNLCK;
1687 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
1688out2:
3b568787 1689 error1 = vn_close(vp, FWRITE, td);
984263bc
MD
1690 if (error == 0)
1691 error = error1;
1692 return (error);
1693}
1694
1695/*
1696 * Nonexistent system call-- signal process (may want to handle it).
1697 * Flag error in case process won't see signal immediately (blocked or ignored).
1698 */
984263bc
MD
1699/* ARGSUSED */
1700int
41c20dac 1701nosys(struct nosys_args *args)
984263bc 1702{
41c20dac 1703 psignal(curproc, SIGSYS);
984263bc
MD
1704 return (EINVAL);
1705}
1706
1707/*
1708 * Send a SIGIO or SIGURG signal to a process or process group using
1709 * stored credentials rather than those of the current process.
1710 */
1711void
dadab5e9 1712pgsigio(struct sigio *sigio, int sig, int checkctty)
984263bc
MD
1713{
1714 if (sigio == NULL)
1715 return;
1716
1717 if (sigio->sio_pgid > 0) {
1718 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
1719 sigio->sio_proc))
1720 psignal(sigio->sio_proc, sig);
1721 } else if (sigio->sio_pgid < 0) {
1722 struct proc *p;
1723
1724 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist)
1725 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
1726 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
1727 psignal(p, sig);
1728 }
1729}
1730
1731static int
1732filt_sigattach(struct knote *kn)
1733{
1734 struct proc *p = curproc;
1735
1736 kn->kn_ptr.p_proc = p;
1737 kn->kn_flags |= EV_CLEAR; /* automatically set */
1738
1739 /* XXX lock the proc here while adding to the list? */
1740 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext);
1741
1742 return (0);
1743}
1744
1745static void
1746filt_sigdetach(struct knote *kn)
1747{
1748 struct proc *p = kn->kn_ptr.p_proc;
1749
1750 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext);
1751}
1752
1753/*
1754 * signal knotes are shared with proc knotes, so we apply a mask to
1755 * the hint in order to differentiate them from process hints. This
1756 * could be avoided by using a signal-specific knote list, but probably
1757 * isn't worth the trouble.
1758 */
1759static int
1760filt_signal(struct knote *kn, long hint)
1761{
984263bc
MD
1762 if (hint & NOTE_SIGNAL) {
1763 hint &= ~NOTE_SIGNAL;
1764
1765 if (kn->kn_id == hint)
1766 kn->kn_data++;
1767 }
1768 return (kn->kn_data != 0);
1769}