Fix a minor bug in the last commit. lwp_cpumask has to be in the LWP copy
[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 $
8fa76237 40 * $DragonFly: src/sys/kern/kern_sig.c,v 1.49 2006/05/25 07:36:34 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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226int
227kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact)
984263bc 228{
65957d54
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{
1fd87d54
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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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MD
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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MD
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{
65957d54
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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MD
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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MD
579 int error;
580
65957d54
DRJ
581 if (uap->ss) {
582 error = copyin(uap->ss, &ss, sizeof(ss));
583 if (error)
584 return (error);
984263bc 585 }
65957d54
DRJ
586
587 error = kern_sigaltstack(uap->ss ? &ss : NULL,
588 uap->oss ? &oss : NULL);
589
590 if (error == 0 && uap->oss)
591 error = copyout(&oss, uap->oss, sizeof(*uap->oss));
592 return (error);
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593}
594
595/*
596 * Common code for kill process group/broadcast kill.
597 * cp is calling process.
598 */
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599struct killpg_info {
600 int nfound;
601 int sig;
602};
603
604static int killpg_all_callback(struct proc *p, void *data);
605
65957d54
DRJ
606static int
607killpg(int sig, int pgid, int all)
984263bc 608{
8fa76237 609 struct killpg_info info;
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610 struct proc *cp = curproc;
611 struct proc *p;
984263bc 612 struct pgrp *pgrp;
8fa76237
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613
614 info.nfound = 0;
615 info.sig = sig;
984263bc 616
8ebcad3f 617 if (all) {
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618 /*
619 * broadcast
620 */
8fa76237 621 allproc_scan(killpg_all_callback, &info);
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622 } else {
623 if (pgid == 0) {
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624 /*
625 * zero pgid means send to my process group.
626 */
627 pgrp = cp->p_pgrp;
8ebcad3f 628 } else {
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629 pgrp = pgfind(pgid);
630 if (pgrp == NULL)
631 return (ESRCH);
632 }
633 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
f026f3b0
MD
634 if (p->p_pid <= 1 ||
635 (p->p_flag & (P_SYSTEM | P_ZOMBIE)) ||
636 !CANSIGNAL(p, sig)) {
984263bc 637 continue;
f026f3b0 638 }
8fa76237 639 ++info.nfound;
984263bc
MD
640 if (sig)
641 psignal(p, sig);
642 }
643 }
8fa76237
MD
644 return (info.nfound ? 0 : ESRCH);
645}
646
647static int
648killpg_all_callback(struct proc *p, void *data)
649{
650 struct killpg_info *info = data;
651
652 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) ||
653 p == curproc || !CANSIGNAL(p, info->sig)) {
654 return (0);
655 }
656 ++info->nfound;
657 if (info->sig)
658 psignal(p, info->sig);
659 return(0);
984263bc
MD
660}
661
984263bc 662int
65957d54 663kern_kill(int sig, int pid)
984263bc 664{
65957d54
DRJ
665 struct thread *td = curthread;
666 struct proc *p = td->td_proc;
984263bc 667
65957d54 668 if ((u_int)sig > _SIG_MAXSIG)
984263bc 669 return (EINVAL);
65957d54 670 if (pid > 0) {
984263bc 671 /* kill single process */
65957d54 672 if ((p = pfind(pid)) == NULL)
984263bc 673 return (ESRCH);
65957d54 674 if (!CANSIGNAL(p, sig))
984263bc 675 return (EPERM);
65957d54
DRJ
676 if (sig)
677 psignal(p, sig);
984263bc
MD
678 return (0);
679 }
65957d54 680 switch (pid) {
984263bc 681 case -1: /* broadcast signal */
65957d54 682 return (killpg(sig, 0, 1));
984263bc 683 case 0: /* signal own process group */
65957d54 684 return (killpg(sig, 0, 0));
984263bc 685 default: /* negative explicit process group */
65957d54 686 return (killpg(sig, -pid, 0));
984263bc
MD
687 }
688 /* NOTREACHED */
689}
690
984263bc 691int
65957d54 692kill(struct kill_args *uap)
984263bc 693{
65957d54
DRJ
694 int error;
695
696 error = kern_kill(uap->signum, uap->pid);
697
698 return (error);
984263bc 699}
984263bc
MD
700
701/*
702 * Send a signal to a process group.
703 */
704void
41c20dac 705gsignal(int pgid, int sig)
984263bc
MD
706{
707 struct pgrp *pgrp;
708
709 if (pgid && (pgrp = pgfind(pgid)))
710 pgsignal(pgrp, sig, 0);
711}
712
713/*
714 * Send a signal to a process group. If checktty is 1,
715 * limit to members which have a controlling terminal.
716 */
717void
8ebcad3f 718pgsignal(struct pgrp *pgrp, int sig, int checkctty)
984263bc 719{
1fd87d54 720 struct proc *p;
984263bc
MD
721
722 if (pgrp)
723 LIST_FOREACH(p, &pgrp->pg_members, p_pglist)
724 if (checkctty == 0 || p->p_flag & P_CONTROLT)
725 psignal(p, sig);
726}
727
728/*
729 * Send a signal caused by a trap to the current process.
730 * If it will be caught immediately, deliver it with correct code.
731 * Otherwise, post it normally.
732 */
733void
8ebcad3f 734trapsignal(struct proc *p, int sig, u_long code)
984263bc 735{
dadab5e9 736 struct sigacts *ps = p->p_sigacts;
984263bc
MD
737
738 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
739 !SIGISMEMBER(p->p_sigmask, sig)) {
740 p->p_stats->p_ru.ru_nsignals++;
741#ifdef KTRACE
dadab5e9 742 if (KTRPOINT(p->p_thread, KTR_PSIG))
a9b80e23 743 ktrpsig(p, sig, ps->ps_sigact[_SIG_IDX(sig)],
984263bc
MD
744 &p->p_sigmask, code);
745#endif
746 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
747 &p->p_sigmask, code);
748 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
749 if (!SIGISMEMBER(ps->ps_signodefer, sig))
750 SIGADDSET(p->p_sigmask, sig);
751 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
752 /*
65957d54 753 * See kern_sigaction() for origin of this code.
984263bc
MD
754 */
755 SIGDELSET(p->p_sigcatch, sig);
756 if (sig != SIGCONT &&
757 sigprop(sig) & SA_IGNORE)
758 SIGADDSET(p->p_sigignore, sig);
759 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
760 }
761 } else {
762 p->p_code = code; /* XXX for core dump/debugger */
763 p->p_sig = sig; /* XXX to verify code */
764 psignal(p, sig);
765 }
766}
767
768/*
769 * Send the signal to the process. If the signal has an action, the action
770 * is usually performed by the target process rather than the caller; we add
771 * the signal to the set of pending signals for the process.
772 *
773 * Exceptions:
774 * o When a stop signal is sent to a sleeping process that takes the
775 * default action, the process is stopped without awakening it.
776 * o SIGCONT restarts stopped processes (or puts them back to sleep)
777 * regardless of the signal action (eg, blocked or ignored).
778 *
779 * Other ignored signals are discarded immediately.
780 */
781void
8ebcad3f 782psignal(struct proc *p, int sig)
984263bc 783{
553ea3c8 784 struct lwp *lp = &p->p_lwp;
e43a034f 785 int prop;
cb973d15 786 sig_t action;
984263bc
MD
787
788 if (sig > _SIG_MAXSIG || sig <= 0) {
789 printf("psignal: signal %d\n", sig);
790 panic("psignal signal number");
791 }
792
e43a034f 793 crit_enter();
984263bc 794 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
e43a034f 795 crit_exit();
984263bc
MD
796
797 prop = sigprop(sig);
798
799 /*
800 * If proc is traced, always give parent a chance;
801 * if signal event is tracked by procfs, give *that*
802 * a chance, as well.
803 */
8ebcad3f 804 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) {
984263bc 805 action = SIG_DFL;
8ebcad3f 806 } else {
984263bc
MD
807 /*
808 * If the signal is being ignored,
809 * then we forget about it immediately.
810 * (Note: we don't set SIGCONT in p_sigignore,
811 * and if it is set to SIG_IGN,
812 * action will be SIG_DFL here.)
813 */
814 if (SIGISMEMBER(p->p_sigignore, sig) || (p->p_flag & P_WEXIT))
815 return;
816 if (SIGISMEMBER(p->p_sigmask, sig))
817 action = SIG_HOLD;
818 else if (SIGISMEMBER(p->p_sigcatch, sig))
819 action = SIG_CATCH;
820 else
821 action = SIG_DFL;
822 }
823
824 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
8ebcad3f 825 (p->p_flag & P_TRACED) == 0) {
984263bc 826 p->p_nice = NZERO;
8ebcad3f 827 }
984263bc 828
344ad853
MD
829 /*
830 * If continuing, clear any pending STOP signals.
831 */
984263bc
MD
832 if (prop & SA_CONT)
833 SIG_STOPSIGMASK(p->p_siglist);
9d63d5c0 834
984263bc
MD
835 if (prop & SA_STOP) {
836 /*
837 * If sending a tty stop signal to a member of an orphaned
838 * process group, discard the signal here if the action
839 * is default; don't stop the process below if sleeping,
840 * and don't clear any pending SIGCONT.
841 */
842 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
8ebcad3f 843 action == SIG_DFL) {
984263bc 844 return;
8ebcad3f 845 }
984263bc
MD
846 SIG_CONTSIGMASK(p->p_siglist);
847 }
848 SIGADDSET(p->p_siglist, sig);
849
850 /*
851 * Defer further processing for signals which are held,
852 * except that stopped processes must be continued by SIGCONT.
853 */
344ad853
MD
854 if (action == SIG_HOLD) {
855 if ((prop & SA_CONT) == 0 || (p->p_flag & P_STOPPED) == 0)
856 return;
857 }
e43a034f
MD
858
859 crit_enter();
860
344ad853
MD
861 /*
862 * Process is in tsleep and not stopped
863 */
864 if (p->p_stat == SSLEEP && (p->p_flag & P_STOPPED) == 0) {
984263bc 865 /*
344ad853 866 * If the process is sleeping uninterruptibly
984263bc
MD
867 * we can't interrupt the sleep... the signal will
868 * be noticed when the process returns through
869 * trap() or syscall().
870 */
871 if ((p->p_flag & P_SINTR) == 0)
872 goto out;
344ad853 873
984263bc 874 /*
344ad853 875 * If the process is sleeping and traced, make it runnable
984263bc
MD
876 * so it can discover the signal in issignal() and stop
877 * for the parent.
344ad853
MD
878 *
879 * If the process is stopped and traced, no further action
880 * is necessary.
984263bc
MD
881 */
882 if (p->p_flag & P_TRACED)
883 goto run;
344ad853 884
984263bc 885 /*
344ad853
MD
886 * If the process is sleeping and SA_CONT, and the signal
887 * mode is SIG_DFL, then make the process runnable.
888 *
889 * However, do *NOT* set P_BREAKTSLEEP. We do not want
890 * a SIGCONT to terminate an interruptable tsleep early
891 * and generate a spurious EINTR.
984263bc
MD
892 */
893 if ((prop & SA_CONT) && action == SIG_DFL) {
894 SIGDELSET(p->p_siglist, sig);
344ad853 895 goto run_no_break;
984263bc 896 }
344ad853 897
984263bc 898 /*
344ad853
MD
899 * If the process is sleeping and receives a STOP signal,
900 * process immediately if possible. All other (caught or
901 * default) signals cause the process to run.
984263bc
MD
902 */
903 if (prop & SA_STOP) {
904 if (action != SIG_DFL)
26a0694b 905 goto run;
344ad853 906
984263bc 907 /*
344ad853
MD
908 * If a child holding parent blocked, stopping
909 * could cause deadlock. Take no action at this
910 * time.
984263bc
MD
911 */
912 if (p->p_flag & P_PPWAIT)
913 goto out;
344ad853
MD
914
915 /*
916 * Do not actually try to manipulate the process
917 * while it is sleeping, simply set P_STOPPED to
918 * indicate that it should stop as soon as it safely
919 * can.
920 */
984263bc 921 SIGDELSET(p->p_siglist, sig);
344ad853
MD
922 p->p_flag |= P_STOPPED;
923 p->p_flag &= ~P_WAITED;
984263bc 924 p->p_xstat = sig;
25c776be 925 wakeup(p->p_pptr);
984263bc
MD
926 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0)
927 psignal(p->p_pptr, SIGCHLD);
984263bc 928 goto out;
8ebcad3f 929 }
344ad853 930
984263bc 931 /*
344ad853
MD
932 * Otherwise the signal can interrupt the sleep.
933 */
934 goto run;
935 }
936
937 /*
938 * Process is in tsleep and is stopped
939 */
940 if (p->p_stat == SSLEEP && (p->p_flag & P_STOPPED)) {
941 /*
942 * If the process is stopped and is being traced, then no
943 * further action is necessary.
984263bc
MD
944 */
945 if (p->p_flag & P_TRACED)
946 goto out;
947
948 /*
344ad853
MD
949 * If the process is stopped and receives a KILL signal,
950 * make the process runnable.
984263bc
MD
951 */
952 if (sig == SIGKILL)
26a0694b 953 goto run;
984263bc 954
344ad853
MD
955 /*
956 * If the process is stopped and receives a CONT signal,
957 * then try to make the process runnable again.
958 */
984263bc
MD
959 if (prop & SA_CONT) {
960 /*
961 * If SIGCONT is default (or ignored), we continue the
962 * process but don't leave the signal in p_siglist, as
963 * it has no further action. If SIGCONT is held, we
964 * continue the process and leave the signal in
965 * p_siglist. If the process catches SIGCONT, let it
344ad853 966 * handle the signal itself.
984263bc
MD
967 */
968 if (action == SIG_DFL)
969 SIGDELSET(p->p_siglist, sig);
970 if (action == SIG_CATCH)
26a0694b 971 goto run;
984263bc 972
984263bc 973 /*
344ad853
MD
974 * Make runnable but do not break a tsleep unless
975 * some other signal was pending.
984263bc 976 */
344ad853
MD
977 goto run_no_break;
978 }
979
980 /*
981 * If the process is stopped and receives another STOP
982 * signal, we do not need to stop it again. If we did
983 * the shell could get confused.
984 */
985 if (prop & SA_STOP) {
984263bc
MD
986 SIGDELSET(p->p_siglist, sig);
987 goto out;
988 }
989
990 /*
344ad853
MD
991 * Otherwise the process is sleeping interruptably but
992 * is stopped, just set the P_BREAKTSLEEP flag and take
993 * no further action. The next runnable action will wake
994 * the process up.
984263bc 995 */
344ad853 996 p->p_flag |= P_BREAKTSLEEP;
984263bc 997 goto out;
344ad853
MD
998 }
999
1000 /*
1001 * Otherwise the process is running
1002 *
1003 * SRUN, SIDL, SZOMB do nothing with the signal,
1004 * other than kicking ourselves if we are running.
1005 * It will either never be noticed, or noticed very soon.
1006 *
1007 * Note that p_thread may be NULL or may not be completely
1008 * initialized if the process is in the SIDL or SZOMB state.
1009 *
1010 * For SMP we may have to forward the request to another cpu.
1011 * YYY the MP lock prevents the target process from moving
1012 * to another cpu, see kern/kern_switch.c
1013 *
1014 * If the target thread is waiting on its message port,
1015 * wakeup the target thread so it can check (or ignore)
1016 * the new signal. YYY needs cleanup.
1017 */
1018 if (lp == lwkt_preempted_proc()) {
1019 signotify();
1020 } else if (p->p_stat == SRUN) {
1021 struct thread *td = p->p_thread;
1022
1023 KASSERT(td != NULL,
1024 ("pid %d NULL p_thread stat %d flags %08x",
1025 p->p_pid, p->p_stat, p->p_flag));
1026
984263bc 1027#ifdef SMP
344ad853
MD
1028 if (td->td_gd != mycpu)
1029 lwkt_send_ipiq(td->td_gd, signotify_remote, lp);
1030 else
984263bc 1031#endif
344ad853
MD
1032 if (td->td_msgport.mp_flags & MSGPORTF_WAITING)
1033 lwkt_schedule(td);
984263bc 1034 }
344ad853 1035 goto out;
984263bc 1036 /*NOTREACHED*/
984263bc 1037run:
344ad853
MD
1038 /*
1039 * Make runnable and break out of any tsleep as well.
1040 */
1041 p->p_flag |= P_BREAKTSLEEP;
1042run_no_break:
984263bc
MD
1043 setrunnable(p);
1044out:
e43a034f 1045 crit_exit();
984263bc
MD
1046}
1047
cb973d15
MD
1048#ifdef SMP
1049
1050/*
1051 * This function is called via an IPI. We will be in a critical section but
1052 * the MP lock will NOT be held. Also note that by the time the ipi message
1053 * gets to us the process 'p' (arg) may no longer be scheduled or even valid.
1054 */
1055static void
1056signotify_remote(void *arg)
1057{
553ea3c8 1058 struct lwp *lp = arg;
60be1d11 1059
553ea3c8 1060 if (lp == lwkt_preempted_proc()) {
235957ed 1061 signotify();
60be1d11 1062 } else {
553ea3c8 1063 struct thread *td = lp->lwp_thread;
60be1d11
MD
1064 if (td->td_msgport.mp_flags & MSGPORTF_WAITING)
1065 lwkt_schedule(td);
1066 }
cb973d15
MD
1067}
1068
1069#endif
1070
3a59f0f7
DX
1071static int
1072kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout)
1073{
1074 sigset_t savedmask, set;
1075 struct proc *p = curproc;
1076 int error, sig, hz, timevalid = 0;
1077 struct timespec rts, ets, ts;
1078 struct timeval tv;
1079
1080 error = 0;
1081 sig = 0;
1082 SIG_CANTMASK(waitset);
1083 savedmask = p->p_sigmask;
1084
1085 if (timeout) {
f8c41806
DX
1086 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 &&
1087 timeout->tv_nsec < 1000000000) {
3a59f0f7
DX
1088 timevalid = 1;
1089 getnanouptime(&rts);
1090 ets = rts;
1091 timespecadd(&ets, timeout);
1092 }
1093 }
1094
1095 for (;;) {
1096 set = p->p_siglist;
1097 SIGSETAND(set, waitset);
1098 if ((sig = sig_ffs(&set)) != 0) {
1099 SIGFILLSET(p->p_sigmask);
1100 SIGDELSET(p->p_sigmask, sig);
976f0bc5 1101 SIG_CANTMASK(p->p_sigmask);
3a59f0f7
DX
1102 sig = issignal(p);
1103 /*
1104 * It may be a STOP signal, in the case, issignal
1105 * returns 0, because we may stop there, and new
1106 * signal can come in, we should restart if we got
1107 * nothing.
1108 */
1109 if (sig == 0)
1110 continue;
1111 else
1112 break;
1113 }
1114
1115 /*
1116 * Previous checking got nothing, and we retried but still
1117 * got nothing, we should return the error status.
1118 */
1119 if (error)
1120 break;
1121
1122 /*
1123 * POSIX says this must be checked after looking for pending
1124 * signals.
1125 */
1126 if (timeout) {
1127 if (!timevalid) {
1128 error = EINVAL;
1129 break;
1130 }
1131 getnanouptime(&rts);
1132 if (timespeccmp(&rts, &ets, >=)) {
1133 error = EAGAIN;
1134 break;
1135 }
1136 ts = ets;
1137 timespecsub(&ts, &rts);
1138 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1139 hz = tvtohz_high(&tv);
1140 } else
1141 hz = 0;
1142
1143 p->p_sigmask = savedmask;
1144 SIGSETNAND(p->p_sigmask, waitset);
1145 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz);
1146 if (timeout) {
1147 if (error == ERESTART) {
1148 /* can not restart a timeout wait. */
1149 error = EINTR;
1150 } else if (error == EAGAIN) {
1151 /* will calculate timeout by ourself. */
1152 error = 0;
1153 }
1154 }
1155 /* Retry ... */
1156 }
1157
1158 p->p_sigmask = savedmask;
1159 if (sig) {
1160 error = 0;
1161 bzero(info, sizeof(*info));
1162 info->si_signo = sig;
1163 SIGDELSET(p->p_siglist, sig); /* take the signal! */
1e1bd00b
DX
1164
1165 if (sig == SIGKILL)
1166 sigexit(p, sig);
3a59f0f7
DX
1167 }
1168 return (error);
1169}
1170
1171int
1172sigtimedwait(struct sigtimedwait_args *uap)
1173{
1174 struct timespec ts;
1175 struct timespec *timeout;
1176 sigset_t set;
1177 siginfo_t info;
1178 int error;
1179
1180 if (uap->timeout) {
1181 error = copyin(uap->timeout, &ts, sizeof(ts));
1182 if (error)
1183 return (error);
1184 timeout = &ts;
1185 } else {
1186 timeout = NULL;
1187 }
1188 error = copyin(uap->set, &set, sizeof(set));
1189 if (error)
1190 return (error);
1191 error = kern_sigtimedwait(set, &info, timeout);
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
1204int
1205sigwaitinfo(struct sigwaitinfo_args *uap)
1206{
1207 siginfo_t info;
1208 sigset_t set;
1209 int error;
1210
1211 error = copyin(uap->set, &set, sizeof(set));
1212 if (error)
1213 return (error);
1214 error = kern_sigtimedwait(set, &info, NULL);
1215 if (error)
1216 return (error);
1217 if (uap->info)
1218 error = copyout(&info, uap->info, sizeof(info));
1219 /* Repost if we got an error. */
1220 if (error)
1221 psignal(curproc, info.si_signo);
1222 else
1223 uap->sysmsg_result = info.si_signo;
1224 return (error);
1225}
1226
a94976ad
MD
1227/*
1228 * If the current process has received a signal that would interrupt a
1229 * system call, return EINTR or ERESTART as appropriate.
1230 */
1231int
1232iscaught(struct proc *p)
1233{
1234 int sig;
1235
1236 if (p) {
1237 if ((sig = CURSIG(p)) != 0) {
1238 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1239 return (EINTR);
1240 return (ERESTART);
1241 }
1242 }
1243 return(EWOULDBLOCK);
1244}
1245
984263bc
MD
1246/*
1247 * If the current process has received a signal (should be caught or cause
1248 * termination, should interrupt current syscall), return the signal number.
1249 * Stop signals with default action are processed immediately, then cleared;
1250 * they aren't returned. This is checked after each entry to the system for
1251 * a syscall or trap (though this can usually be done without calling issignal
1252 * by checking the pending signal masks in the CURSIG macro.) The normal call
1253 * sequence is
1254 *
bf189c26
MD
1255 * This routine is called via CURSIG/__cursig and the MP lock might not be
1256 * held. Obtain the MP lock for the duration of the operation.
1257 *
984263bc
MD
1258 * while (sig = CURSIG(curproc))
1259 * postsig(sig);
1260 */
1261int
8ebcad3f 1262issignal(struct proc *p)
984263bc
MD
1263{
1264 sigset_t mask;
1fd87d54 1265 int sig, prop;
984263bc 1266
bf189c26 1267 get_mplock();
984263bc
MD
1268 for (;;) {
1269 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
1270
1271 mask = p->p_siglist;
1272 SIGSETNAND(mask, p->p_sigmask);
1273 if (p->p_flag & P_PPWAIT)
1274 SIG_STOPSIGMASK(mask);
bf189c26
MD
1275 if (!SIGNOTEMPTY(mask)) { /* no signal to send */
1276 rel_mplock();
984263bc 1277 return (0);
bf189c26 1278 }
984263bc
MD
1279 sig = sig_ffs(&mask);
1280
1281 STOPEVENT(p, S_SIG, sig);
1282
1283 /*
1284 * We should see pending but ignored signals
1285 * only if P_TRACED was on when they were posted.
1286 */
1287 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
1288 SIGDELSET(p->p_siglist, sig);
1289 continue;
1290 }
344ad853 1291 if ((p->p_flag & P_TRACED) && (p->p_flag & P_PPWAIT) == 0) {
984263bc 1292 /*
344ad853
MD
1293 * If traced, always stop, and stay stopped until
1294 * released by the parent.
1295 *
1296 * NOTE: P_STOPPED may get cleared during the loop,
1297 * but we do not re-notify the parent if we have
1298 * to loop several times waiting for the parent
1299 * to let us continue.
984263bc
MD
1300 */
1301 p->p_xstat = sig;
344ad853
MD
1302 p->p_flag |= P_STOPPED;
1303 p->p_flag &= ~P_WAITED;
984263bc
MD
1304 psignal(p->p_pptr, SIGCHLD);
1305 do {
344ad853
MD
1306 tstop(p);
1307 } while (!trace_req(p) && (p->p_flag & P_TRACED));
1308 p->p_flag &= ~P_STOPPED;
984263bc
MD
1309
1310 /*
1311 * If parent wants us to take the signal,
1312 * then it will leave it in p->p_xstat;
1313 * otherwise we just look for signals again.
1314 */
1315 SIGDELSET(p->p_siglist, sig); /* clear old signal */
1316 sig = p->p_xstat;
1317 if (sig == 0)
1318 continue;
1319
1320 /*
1321 * Put the new signal into p_siglist. If the
1322 * signal is being masked, look for other signals.
1323 */
1324 SIGADDSET(p->p_siglist, sig);
1325 if (SIGISMEMBER(p->p_sigmask, sig))
1326 continue;
1327
1328 /*
1329 * If the traced bit got turned off, go back up
1330 * to the top to rescan signals. This ensures
1331 * that p_sig* and ps_sigact are consistent.
1332 */
1333 if ((p->p_flag & P_TRACED) == 0)
1334 continue;
1335 }
1336
1337 prop = sigprop(sig);
1338
1339 /*
1340 * Decide whether the signal should be returned.
1341 * Return the signal's number, or fall through
1342 * to clear it from the pending mask.
1343 */
1344 switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
984263bc
MD
1345 case (int)SIG_DFL:
1346 /*
1347 * Don't take default actions on system processes.
1348 */
1349 if (p->p_pid <= 1) {
1350#ifdef DIAGNOSTIC
1351 /*
1352 * Are you sure you want to ignore SIGSEGV
1353 * in init? XXX
1354 */
1355 printf("Process (pid %lu) got signal %d\n",
1356 (u_long)p->p_pid, sig);
1357#endif
1358 break; /* == ignore */
1359 }
f758a39e
MD
1360
1361 /*
1362 * Handle the in-kernel checkpoint action
1363 */
1364 if (prop & SA_CKPT) {
0ba6fbbf 1365 checkpoint_signal_handler(p);
f758a39e
MD
1366 break;
1367 }
1368
984263bc
MD
1369 /*
1370 * If there is a pending stop signal to process
1371 * with default action, stop here,
1372 * then clear the signal. However,
1373 * if process is member of an orphaned
1374 * process group, ignore tty stop signals.
1375 */
1376 if (prop & SA_STOP) {
1377 if (p->p_flag & P_TRACED ||
1378 (p->p_pgrp->pg_jobc == 0 &&
1379 prop & SA_TTYSTOP))
1380 break; /* == ignore */
1381 p->p_xstat = sig;
344ad853
MD
1382 p->p_flag |= P_STOPPED;
1383 p->p_flag &= ~P_WAITED;
1384
984263bc
MD
1385 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0)
1386 psignal(p->p_pptr, SIGCHLD);
344ad853
MD
1387 while (p->p_flag & P_STOPPED) {
1388 tstop(p);
1389 }
984263bc
MD
1390 break;
1391 } else if (prop & SA_IGNORE) {
1392 /*
1393 * Except for SIGCONT, shouldn't get here.
1394 * Default action is to ignore; drop it.
1395 */
1396 break; /* == ignore */
8ebcad3f 1397 } else {
bf189c26 1398 rel_mplock();
984263bc 1399 return (sig);
8ebcad3f
MD
1400 }
1401
984263bc
MD
1402 /*NOTREACHED*/
1403
1404 case (int)SIG_IGN:
1405 /*
1406 * Masking above should prevent us ever trying
1407 * to take action on an ignored signal other
1408 * than SIGCONT, unless process is traced.
1409 */
1410 if ((prop & SA_CONT) == 0 &&
1411 (p->p_flag & P_TRACED) == 0)
1412 printf("issignal\n");
1413 break; /* == ignore */
1414
1415 default:
1416 /*
1417 * This signal has an action, let
1418 * postsig() process it.
1419 */
bf189c26 1420 rel_mplock();
984263bc
MD
1421 return (sig);
1422 }
1423 SIGDELSET(p->p_siglist, sig); /* take the signal! */
1424 }
1425 /* NOTREACHED */
1426}
1427
984263bc
MD
1428/*
1429 * Take the action for the specified signal
1430 * from the current set of pending signals.
1431 */
1432void
8ebcad3f 1433postsig(int sig)
984263bc 1434{
41c20dac 1435 struct proc *p = curproc;
984263bc
MD
1436 struct sigacts *ps = p->p_sigacts;
1437 sig_t action;
1438 sigset_t returnmask;
1439 int code;
1440
1441 KASSERT(sig != 0, ("postsig"));
1442
1443 SIGDELSET(p->p_siglist, sig);
1444 action = ps->ps_sigact[_SIG_IDX(sig)];
1445#ifdef KTRACE
dadab5e9 1446 if (KTRPOINT(p->p_thread, KTR_PSIG))
a9b80e23
MD
1447 ktrpsig(p, sig, action, p->p_flag & P_OLDMASK ?
1448 &p->p_oldsigmask : &p->p_sigmask, 0);
984263bc
MD
1449#endif
1450 STOPEVENT(p, S_SIG, sig);
1451
1452 if (action == SIG_DFL) {
1453 /*
1454 * Default action, where the default is to kill
1455 * the process. (Other cases were ignored above.)
1456 */
1457 sigexit(p, sig);
1458 /* NOTREACHED */
1459 } else {
1460 /*
1461 * If we get here, the signal must be caught.
1462 */
1463 KASSERT(action != SIG_IGN && !SIGISMEMBER(p->p_sigmask, sig),
1464 ("postsig action"));
1465 /*
1466 * Set the new mask value and also defer further
1467 * occurrences of this signal.
1468 *
1469 * Special case: user has done a sigsuspend. Here the
1470 * current mask is not of interest, but rather the
1471 * mask from before the sigsuspend is what we want
1472 * restored after the signal processing is completed.
1473 */
e43a034f 1474 crit_enter();
984263bc
MD
1475 if (p->p_flag & P_OLDMASK) {
1476 returnmask = p->p_oldsigmask;
1477 p->p_flag &= ~P_OLDMASK;
8ebcad3f 1478 } else {
984263bc 1479 returnmask = p->p_sigmask;
8ebcad3f 1480 }
984263bc
MD
1481
1482 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
1483 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1484 SIGADDSET(p->p_sigmask, sig);
1485
1486 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
1487 /*
65957d54 1488 * See kern_sigaction() for origin of this code.
984263bc
MD
1489 */
1490 SIGDELSET(p->p_sigcatch, sig);
1491 if (sig != SIGCONT &&
1492 sigprop(sig) & SA_IGNORE)
1493 SIGADDSET(p->p_sigignore, sig);
1494 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1495 }
e43a034f 1496 crit_exit();
984263bc
MD
1497 p->p_stats->p_ru.ru_nsignals++;
1498 if (p->p_sig != sig) {
1499 code = 0;
1500 } else {
1501 code = p->p_code;
1502 p->p_code = 0;
1503 p->p_sig = 0;
1504 }
1505 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
1506 }
1507}
1508
1509/*
1510 * Kill the current process for stated reason.
1511 */
1512void
8ebcad3f 1513killproc(struct proc *p, char *why)
984263bc
MD
1514{
1515 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm,
41c20dac 1516 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
984263bc
MD
1517 psignal(p, SIGKILL);
1518}
1519
1520/*
1521 * Force the current process to exit with the specified signal, dumping core
1522 * if appropriate. We bypass the normal tests for masked and caught signals,
1523 * allowing unrecoverable failures to terminate the process without changing
1524 * signal state. Mark the accounting record with the signal termination.
1525 * If dumping core, save the signal number for the debugger. Calls exit and
1526 * does not return.
1527 */
1528void
41c20dac 1529sigexit(struct proc *p, int sig)
984263bc 1530{
984263bc
MD
1531 p->p_acflag |= AXSIG;
1532 if (sigprop(sig) & SA_CORE) {
1533 p->p_sig = sig;
1534 /*
1535 * Log signals which would cause core dumps
1536 * (Log as LOG_INFO to appease those who don't want
1537 * these messages.)
1538 * XXX : Todo, as well as euid, write out ruid too
1539 */
1540 if (coredump(p) == 0)
1541 sig |= WCOREFLAG;
1542 if (kern_logsigexit)
1543 log(LOG_INFO,
1544 "pid %d (%s), uid %d: exited on signal %d%s\n",
1545 p->p_pid, p->p_comm,
41c20dac 1546 p->p_ucred ? p->p_ucred->cr_uid : -1,
984263bc
MD
1547 sig &~ WCOREFLAG,
1548 sig & WCOREFLAG ? " (core dumped)" : "");
1549 }
41c20dac 1550 exit1(W_EXITCODE(0, sig));
984263bc
MD
1551 /* NOTREACHED */
1552}
1553
1554static char corefilename[MAXPATHLEN+1] = {"%N.core"};
1555SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
1556 sizeof(corefilename), "process corefile name format string");
1557
1558/*
1559 * expand_name(name, uid, pid)
1560 * Expand the name described in corefilename, using name, uid, and pid.
1561 * corefilename is a printf-like string, with three format specifiers:
1562 * %N name of process ("name")
1563 * %P process id (pid)
1564 * %U user id (uid)
1565 * For example, "%N.core" is the default; they can be disabled completely
1566 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
1567 * This is controlled by the sysctl variable kern.corefile (see above).
1568 */
1569
1570static char *
8ebcad3f
MD
1571expand_name(const char *name, uid_t uid, pid_t pid)
1572{
984263bc
MD
1573 char *temp;
1574 char buf[11]; /* Buffer for pid/uid -- max 4B */
1575 int i, n;
1576 char *format = corefilename;
1577 size_t namelen;
1578
1579 temp = malloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
1580 if (temp == NULL)
1581 return NULL;
1582 namelen = strlen(name);
1583 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
1584 int l;
1585 switch (format[i]) {
1586 case '%': /* Format character */
1587 i++;
1588 switch (format[i]) {
1589 case '%':
1590 temp[n++] = '%';
1591 break;
1592 case 'N': /* process name */
1593 if ((n + namelen) > MAXPATHLEN) {
1594 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1595 pid, name, uid, temp, name);
1596 free(temp, M_TEMP);
1597 return NULL;
1598 }
1599 memcpy(temp+n, name, namelen);
1600 n += namelen;
1601 break;
1602 case 'P': /* process id */
1603 l = sprintf(buf, "%u", pid);
1604 if ((n + l) > MAXPATHLEN) {
1605 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1606 pid, name, uid, temp, name);
1607 free(temp, M_TEMP);
1608 return NULL;
1609 }
1610 memcpy(temp+n, buf, l);
1611 n += l;
1612 break;
1613 case 'U': /* user id */
1614 l = sprintf(buf, "%u", uid);
1615 if ((n + l) > MAXPATHLEN) {
1616 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1617 pid, name, uid, temp, name);
1618 free(temp, M_TEMP);
1619 return NULL;
1620 }
1621 memcpy(temp+n, buf, l);
1622 n += l;
1623 break;
1624 default:
1625 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
1626 }
1627 break;
1628 default:
1629 temp[n++] = format[i];
1630 }
1631 }
1632 temp[n] = '\0';
1633 return temp;
1634}
1635
1636/*
1637 * Dump a process' core. The main routine does some
1638 * policy checking, and creates the name of the coredump;
1639 * then it passes on a vnode and a size limit to the process-specific
1640 * coredump routine if there is one; if there _is not_ one, it returns
1641 * ENOSYS; otherwise it returns the error from the process-specific routine.
1642 */
1643
1644static int
dadab5e9 1645coredump(struct proc *p)
984263bc 1646{
dadab5e9
MD
1647 struct vnode *vp;
1648 struct ucred *cred = p->p_ucred;
984263bc 1649 struct flock lf;
fad57d0e 1650 struct nlookupdata nd;
984263bc
MD
1651 struct vattr vattr;
1652 int error, error1;
1653 char *name; /* name of corefile */
1654 off_t limit;
1655
1656 STOPEVENT(p, S_CORE, 0);
1657
1658 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0)
1659 return (EFAULT);
1660
1661 /*
1662 * Note that the bulk of limit checking is done after
1663 * the corefile is created. The exception is if the limit
1664 * for corefiles is 0, in which case we don't bother
1665 * creating the corefile at all. This layout means that
1666 * a corefile is truncated instead of not being created,
1667 * if it is larger than the limit.
1668 */
1669 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
1670 if (limit == 0)
50fd5388 1671 return EFBIG;
984263bc
MD
1672
1673 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
1674 if (name == NULL)
1675 return (EINVAL);
fad57d0e
MD
1676 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
1677 if (error == 0)
1678 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
984263bc 1679 free(name, M_TEMP);
fad57d0e
MD
1680 if (error) {
1681 nlookup_done(&nd);
984263bc 1682 return (error);
fad57d0e
MD
1683 }
1684 vp = nd.nl_open_vp;
1685 nd.nl_open_vp = NULL;
1686 nlookup_done(&nd);
984263bc 1687
ca466bae 1688 VOP_UNLOCK(vp, 0);
984263bc
MD
1689 lf.l_whence = SEEK_SET;
1690 lf.l_start = 0;
1691 lf.l_len = 0;
1692 lf.l_type = F_WRLCK;
71c18fe3 1693 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0);
984263bc
MD
1694 if (error)
1695 goto out2;
1696
1697 /* Don't dump to non-regular files or files with links. */
1698 if (vp->v_type != VREG ||
87de5057 1699 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) {
984263bc
MD
1700 error = EFAULT;
1701 goto out1;
1702 }
1703
1704 VATTR_NULL(&vattr);
ca466bae 1705 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
984263bc 1706 vattr.va_size = 0;
87de5057 1707 VOP_SETATTR(vp, &vattr, cred);
984263bc 1708 p->p_acflag |= ACORE;
ca466bae 1709 VOP_UNLOCK(vp, 0);
984263bc
MD
1710
1711 error = p->p_sysent->sv_coredump ?
fad57d0e 1712 p->p_sysent->sv_coredump(p, vp, limit) : ENOSYS;
984263bc
MD
1713
1714out1:
1715 lf.l_type = F_UNLCK;
71c18fe3 1716 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0);
984263bc 1717out2:
87de5057 1718 error1 = vn_close(vp, FWRITE);
984263bc
MD
1719 if (error == 0)
1720 error = error1;
1721 return (error);
1722}
1723
1724/*
1725 * Nonexistent system call-- signal process (may want to handle it).
1726 * Flag error in case process won't see signal immediately (blocked or ignored).
1727 */
984263bc
MD
1728/* ARGSUSED */
1729int
41c20dac 1730nosys(struct nosys_args *args)
984263bc 1731{
41c20dac 1732 psignal(curproc, SIGSYS);
984263bc
MD
1733 return (EINVAL);
1734}
1735
1736/*
1737 * Send a SIGIO or SIGURG signal to a process or process group using
1738 * stored credentials rather than those of the current process.
1739 */
1740void
dadab5e9 1741pgsigio(struct sigio *sigio, int sig, int checkctty)
984263bc
MD
1742{
1743 if (sigio == NULL)
1744 return;
1745
1746 if (sigio->sio_pgid > 0) {
1747 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
1748 sigio->sio_proc))
1749 psignal(sigio->sio_proc, sig);
1750 } else if (sigio->sio_pgid < 0) {
1751 struct proc *p;
1752
1753 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist)
1754 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
1755 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
1756 psignal(p, sig);
1757 }
1758}
1759
1760static int
1761filt_sigattach(struct knote *kn)
1762{
1763 struct proc *p = curproc;
1764
1765 kn->kn_ptr.p_proc = p;
1766 kn->kn_flags |= EV_CLEAR; /* automatically set */
1767
1768 /* XXX lock the proc here while adding to the list? */
1769 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext);
1770
1771 return (0);
1772}
1773
1774static void
1775filt_sigdetach(struct knote *kn)
1776{
1777 struct proc *p = kn->kn_ptr.p_proc;
1778
1779 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext);
1780}
1781
1782/*
1783 * signal knotes are shared with proc knotes, so we apply a mask to
1784 * the hint in order to differentiate them from process hints. This
1785 * could be avoided by using a signal-specific knote list, but probably
1786 * isn't worth the trouble.
1787 */
1788static int
1789filt_signal(struct knote *kn, long hint)
1790{
984263bc
MD
1791 if (hint & NOTE_SIGNAL) {
1792 hint &= ~NOTE_SIGNAL;
1793
1794 if (kn->kn_id == hint)
1795 kn->kn_data++;
1796 }
1797 return (kn->kn_data != 0);
1798}