Annotation of src/sys/kern/kern_sig.c, Revision 1.280
1.280 ! martin 1: /* $NetBSD: kern_sig.c,v 1.279 2008/04/25 11:24:11 ad Exp $ */
1.243 ad 2:
3: /*-
1.277 ad 4: * Copyright (c) 2006, 2007, 2008 The NetBSD Foundation, Inc.
1.243 ad 5: * All rights reserved.
6: *
7: * This code is derived from software contributed to The NetBSD Foundation
8: * by Andrew Doran.
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: *
19: * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20: * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21: * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22: * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23: * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29: * POSSIBILITY OF SUCH DAMAGE.
30: */
1.29 cgd 31:
32: /*
33: * Copyright (c) 1982, 1986, 1989, 1991, 1993
34: * The Regents of the University of California. All rights reserved.
35: * (c) UNIX System Laboratories, Inc.
36: * All or some portions of this file are derived from material licensed
37: * to the University of California by American Telephone and Telegraph
38: * Co. or Unix System Laboratories, Inc. and are reproduced herein with
39: * the permission of UNIX System Laboratories, Inc.
40: *
41: * Redistribution and use in source and binary forms, with or without
42: * modification, are permitted provided that the following conditions
43: * are met:
44: * 1. Redistributions of source code must retain the above copyright
45: * notice, this list of conditions and the following disclaimer.
46: * 2. Redistributions in binary form must reproduce the above copyright
47: * notice, this list of conditions and the following disclaimer in the
48: * documentation and/or other materials provided with the distribution.
1.146 agc 49: * 3. Neither the name of the University nor the names of its contributors
1.29 cgd 50: * may be used to endorse or promote products derived from this software
51: * without specific prior written permission.
52: *
53: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63: * SUCH DAMAGE.
64: *
1.71 fvdl 65: * @(#)kern_sig.c 8.14 (Berkeley) 5/14/95
1.29 cgd 66: */
1.116 lukem 67:
68: #include <sys/cdefs.h>
1.280 ! martin 69: __KERNEL_RCSID(0, "$NetBSD: kern_sig.c,v 1.279 2008/04/25 11:24:11 ad Exp $");
1.70 mrg 70:
1.227 matt 71: #include "opt_ptrace.h"
1.222 rjs 72: #include "opt_multiprocessor.h"
1.74 thorpej 73: #include "opt_compat_sunos.h"
1.158 christos 74: #include "opt_compat_netbsd.h"
1.202 perry 75: #include "opt_compat_netbsd32.h"
1.240 elad 76: #include "opt_pax.h"
1.29 cgd 77:
78: #define SIGPROP /* include signal properties table */
79: #include <sys/param.h>
80: #include <sys/signalvar.h>
81: #include <sys/proc.h>
82: #include <sys/systm.h>
83: #include <sys/wait.h>
84: #include <sys/ktrace.h>
85: #include <sys/syslog.h>
1.59 cgd 86: #include <sys/filedesc.h>
1.243 ad 87: #include <sys/file.h>
1.89 thorpej 88: #include <sys/malloc.h>
89: #include <sys/pool.h>
1.130 thorpej 90: #include <sys/ucontext.h>
1.118 thorpej 91: #include <sys/exec.h>
1.220 elad 92: #include <sys/kauth.h>
1.243 ad 93: #include <sys/acct.h>
94: #include <sys/callout.h>
1.260 ad 95: #include <sys/atomic.h>
1.258 ad 96: #include <sys/cpu.h>
1.29 cgd 97:
1.240 elad 98: #ifdef PAX_SEGVGUARD
99: #include <sys/pax.h>
100: #endif /* PAX_SEGVGUARD */
101:
1.196 skrll 102: #include <uvm/uvm.h>
1.69 mrg 103: #include <uvm/uvm_extern.h>
104:
1.243 ad 105: static void ksiginfo_exechook(struct proc *, void *);
106: static void proc_stop_callout(void *);
107:
108: int sigunwait(struct proc *, const ksiginfo_t *);
109: void sigput(sigpend_t *, struct proc *, ksiginfo_t *);
110: int sigpost(struct lwp *, sig_t, int, int);
111: int sigchecktrace(sigpend_t **);
1.248 thorpej 112: void sigswitch(bool, int, int);
1.243 ad 113: void sigrealloc(ksiginfo_t *);
1.152 christos 114:
1.198 jdolecek 115: sigset_t contsigmask, stopsigmask, sigcantmask;
1.279 ad 116: static pool_cache_t sigacts_cache; /* memory pool for sigacts structures */
1.243 ad 117: static void sigacts_poolpage_free(struct pool *, void *);
118: static void *sigacts_poolpage_alloc(struct pool *, int);
1.254 ad 119: static callout_t proc_stop_ch;
1.196 skrll 120:
121: static struct pool_allocator sigactspool_allocator = {
1.228 christos 122: .pa_alloc = sigacts_poolpage_alloc,
123: .pa_free = sigacts_poolpage_free,
1.196 skrll 124: };
125:
1.243 ad 126: #ifdef DEBUG
127: int kern_logsigexit = 1;
128: #else
129: int kern_logsigexit = 0;
130: #endif
1.89 thorpej 131:
1.243 ad 132: static const char logcoredump[] =
133: "pid %d (%s), uid %d: exited on signal %d (core dumped)\n";
134: static const char lognocoredump[] =
135: "pid %d (%s), uid %d: exited on signal %d (core not dumped, err = %d)\n";
1.237 yamt 136:
1.243 ad 137: POOL_INIT(siginfo_pool, sizeof(siginfo_t), 0, 0, 0, "siginfo",
1.252 ad 138: &pool_allocator_nointr, IPL_NONE);
139: POOL_INIT(ksiginfo_pool, sizeof(ksiginfo_t), 0, 0, 0, "ksiginfo",
1.257 ad 140: NULL, IPL_VM);
1.237 yamt 141:
1.29 cgd 142: /*
1.243 ad 143: * signal_init:
144: *
145: * Initialize global signal-related data structures.
1.152 christos 146: */
1.243 ad 147: void
148: signal_init(void)
1.152 christos 149: {
150:
1.243 ad 151: sigactspool_allocator.pa_pagesz = (PAGE_SIZE)*2;
1.152 christos 152:
1.279 ad 153: sigacts_cache = pool_cache_init(sizeof(struct sigacts), 0, 0, 0,
154: "sigacts", sizeof(struct sigacts) > PAGE_SIZE ?
155: &sigactspool_allocator : NULL, IPL_NONE, NULL, NULL, NULL);
1.152 christos 156:
1.243 ad 157: exechook_establish(ksiginfo_exechook, NULL);
1.152 christos 158:
1.265 ad 159: callout_init(&proc_stop_ch, CALLOUT_MPSAFE);
1.243 ad 160: callout_setfunc(&proc_stop_ch, proc_stop_callout, NULL);
1.152 christos 161: }
162:
163: /*
1.243 ad 164: * sigacts_poolpage_alloc:
165: *
166: * Allocate a page for the sigacts memory pool.
1.152 christos 167: */
1.243 ad 168: static void *
169: sigacts_poolpage_alloc(struct pool *pp, int flags)
1.152 christos 170: {
171:
1.243 ad 172: return (void *)uvm_km_alloc(kernel_map,
173: (PAGE_SIZE)*2, (PAGE_SIZE)*2,
174: ((flags & PR_WAITOK) ? 0 : UVM_KMF_NOWAIT | UVM_KMF_TRYLOCK)
175: | UVM_KMF_WIRED);
1.152 christos 176: }
177:
178: /*
1.243 ad 179: * sigacts_poolpage_free:
180: *
181: * Free a page on behalf of the sigacts memory pool.
1.89 thorpej 182: */
1.243 ad 183: static void
184: sigacts_poolpage_free(struct pool *pp, void *v)
1.89 thorpej 185: {
1.279 ad 186:
1.243 ad 187: uvm_km_free(kernel_map, (vaddr_t)v, (PAGE_SIZE)*2, UVM_KMF_WIRED);
1.89 thorpej 188: }
189:
190: /*
1.243 ad 191: * sigactsinit:
192: *
193: * Create an initial sigctx structure, using the same signal state as
194: * p. If 'share' is set, share the sigctx_proc part, otherwise just
195: * copy it from parent.
1.89 thorpej 196: */
1.243 ad 197: struct sigacts *
198: sigactsinit(struct proc *pp, int share)
1.89 thorpej 199: {
1.259 ad 200: struct sigacts *ps, *ps2;
1.89 thorpej 201:
1.259 ad 202: ps = pp->p_sigacts;
1.243 ad 203:
1.109 jdolecek 204: if (share) {
1.279 ad 205: atomic_inc_uint(&ps->sa_refcnt);
1.259 ad 206: ps2 = ps;
1.109 jdolecek 207: } else {
1.279 ad 208: ps2 = pool_cache_get(sigacts_cache, PR_WAITOK);
1.277 ad 209: /* XXXAD get rid of this */
1.262 ad 210: mutex_init(&ps2->sa_mutex, MUTEX_DEFAULT, IPL_SCHED);
1.259 ad 211: mutex_enter(&ps->sa_mutex);
212: memcpy(&ps2->sa_sigdesc, ps->sa_sigdesc,
213: sizeof(ps2->sa_sigdesc));
214: mutex_exit(&ps->sa_mutex);
215: ps2->sa_refcnt = 1;
1.109 jdolecek 216: }
1.243 ad 217:
1.259 ad 218: return ps2;
1.89 thorpej 219: }
220:
221: /*
1.243 ad 222: * sigactsunshare:
223: *
224: * Make this process not share its sigctx, maintaining all
225: * signal state.
1.89 thorpej 226: */
227: void
1.112 lukem 228: sigactsunshare(struct proc *p)
1.89 thorpej 229: {
1.243 ad 230: struct sigacts *ps, *oldps;
231:
232: oldps = p->p_sigacts;
1.259 ad 233: if (oldps->sa_refcnt == 1)
1.89 thorpej 234: return;
1.279 ad 235: ps = pool_cache_get(sigacts_cache, PR_WAITOK);
1.277 ad 236: /* XXXAD get rid of this */
1.262 ad 237: mutex_init(&ps->sa_mutex, MUTEX_DEFAULT, IPL_SCHED);
1.259 ad 238: memset(&ps->sa_sigdesc, 0, sizeof(ps->sa_sigdesc));
1.243 ad 239: p->p_sigacts = ps;
240: sigactsfree(oldps);
1.89 thorpej 241: }
242:
243: /*
1.243 ad 244: * sigactsfree;
245: *
246: * Release a sigctx structure.
1.89 thorpej 247: */
248: void
1.195 pk 249: sigactsfree(struct sigacts *ps)
1.89 thorpej 250: {
251:
1.279 ad 252: if (atomic_dec_uint_nv(&ps->sa_refcnt) == 0) {
1.243 ad 253: mutex_destroy(&ps->sa_mutex);
1.279 ad 254: pool_cache_put(sigacts_cache, ps);
1.29 cgd 255: }
256: }
257:
258: /*
1.243 ad 259: * siginit:
260: *
261: * Initialize signal state for process 0; set to ignore signals that
262: * are ignored by default and disable the signal stack. Locking not
263: * required as the system is still cold.
1.29 cgd 264: */
265: void
1.112 lukem 266: siginit(struct proc *p)
1.29 cgd 267: {
1.243 ad 268: struct lwp *l;
269: struct sigacts *ps;
270: int signo, prop;
1.79 mycroft 271:
1.112 lukem 272: ps = p->p_sigacts;
1.79 mycroft 273: sigemptyset(&contsigmask);
274: sigemptyset(&stopsigmask);
275: sigemptyset(&sigcantmask);
1.243 ad 276: for (signo = 1; signo < NSIG; signo++) {
277: prop = sigprop[signo];
1.79 mycroft 278: if (prop & SA_CONT)
1.243 ad 279: sigaddset(&contsigmask, signo);
1.79 mycroft 280: if (prop & SA_STOP)
1.243 ad 281: sigaddset(&stopsigmask, signo);
1.79 mycroft 282: if (prop & SA_CANTMASK)
1.243 ad 283: sigaddset(&sigcantmask, signo);
284: if (prop & SA_IGNORE && signo != SIGCONT)
285: sigaddset(&p->p_sigctx.ps_sigignore, signo);
286: sigemptyset(&SIGACTION_PS(ps, signo).sa_mask);
287: SIGACTION_PS(ps, signo).sa_flags = SA_RESTART;
1.79 mycroft 288: }
1.109 jdolecek 289: sigemptyset(&p->p_sigctx.ps_sigcatch);
1.243 ad 290: p->p_sflag &= ~PS_NOCLDSTOP;
291:
292: ksiginfo_queue_init(&p->p_sigpend.sp_info);
293: sigemptyset(&p->p_sigpend.sp_set);
1.29 cgd 294:
1.79 mycroft 295: /*
1.243 ad 296: * Reset per LWP state.
1.79 mycroft 297: */
1.243 ad 298: l = LIST_FIRST(&p->p_lwps);
299: l->l_sigwaited = NULL;
300: l->l_sigstk.ss_flags = SS_DISABLE;
301: l->l_sigstk.ss_size = 0;
302: l->l_sigstk.ss_sp = 0;
303: ksiginfo_queue_init(&l->l_sigpend.sp_info);
304: sigemptyset(&l->l_sigpend.sp_set);
1.89 thorpej 305:
306: /* One reference. */
1.109 jdolecek 307: ps->sa_refcnt = 1;
1.29 cgd 308: }
309:
310: /*
1.243 ad 311: * execsigs:
312: *
313: * Reset signals for an exec of the specified process.
1.29 cgd 314: */
315: void
1.112 lukem 316: execsigs(struct proc *p)
1.29 cgd 317: {
1.243 ad 318: struct sigacts *ps;
319: struct lwp *l;
320: int signo, prop;
321: sigset_t tset;
322: ksiginfoq_t kq;
323:
324: KASSERT(p->p_nlwps == 1);
325:
1.115 thorpej 326: sigactsunshare(p);
1.112 lukem 327: ps = p->p_sigacts;
1.115 thorpej 328:
1.29 cgd 329: /*
1.243 ad 330: * Reset caught signals. Held signals remain held through
331: * l->l_sigmask (unless they were caught, and are now ignored
332: * by default).
1.259 ad 333: *
334: * No need to lock yet, the process has only one LWP and
335: * at this point the sigacts are private to the process.
1.243 ad 336: */
337: sigemptyset(&tset);
338: for (signo = 1; signo < NSIG; signo++) {
339: if (sigismember(&p->p_sigctx.ps_sigcatch, signo)) {
340: prop = sigprop[signo];
1.79 mycroft 341: if (prop & SA_IGNORE) {
342: if ((prop & SA_CONT) == 0)
1.112 lukem 343: sigaddset(&p->p_sigctx.ps_sigignore,
1.243 ad 344: signo);
345: sigaddset(&tset, signo);
1.79 mycroft 346: }
1.243 ad 347: SIGACTION_PS(ps, signo).sa_handler = SIG_DFL;
1.29 cgd 348: }
1.243 ad 349: sigemptyset(&SIGACTION_PS(ps, signo).sa_mask);
350: SIGACTION_PS(ps, signo).sa_flags = SA_RESTART;
1.29 cgd 351: }
1.243 ad 352: ksiginfo_queue_init(&kq);
1.259 ad 353:
1.277 ad 354: mutex_enter(p->p_lock);
1.243 ad 355: sigclearall(p, &tset, &kq);
1.109 jdolecek 356: sigemptyset(&p->p_sigctx.ps_sigcatch);
1.205 christos 357:
358: /*
359: * Reset no zombies if child dies flag as Solaris does.
360: */
1.246 pavel 361: p->p_flag &= ~(PK_NOCLDWAIT | PK_CLDSIGIGN);
1.205 christos 362: if (SIGACTION_PS(ps, SIGCHLD).sa_handler == SIG_IGN)
363: SIGACTION_PS(ps, SIGCHLD).sa_handler = SIG_DFL;
1.79 mycroft 364:
1.29 cgd 365: /*
1.243 ad 366: * Reset per-LWP state.
1.29 cgd 367: */
1.243 ad 368: l = LIST_FIRST(&p->p_lwps);
369: l->l_sigwaited = NULL;
370: l->l_sigstk.ss_flags = SS_DISABLE;
371: l->l_sigstk.ss_size = 0;
372: l->l_sigstk.ss_sp = 0;
373: ksiginfo_queue_init(&l->l_sigpend.sp_info);
374: sigemptyset(&l->l_sigpend.sp_set);
1.277 ad 375: mutex_exit(p->p_lock);
1.243 ad 376:
377: ksiginfo_queue_drain(&kq);
1.29 cgd 378: }
379:
1.243 ad 380: /*
381: * ksiginfo_exechook:
382: *
383: * Free all pending ksiginfo entries from a process on exec.
384: * Additionally, drain any unused ksiginfo structures in the
385: * system back to the pool.
386: *
387: * XXX This should not be a hook, every process has signals.
388: */
389: static void
390: ksiginfo_exechook(struct proc *p, void *v)
1.79 mycroft 391: {
1.243 ad 392: ksiginfoq_t kq;
1.79 mycroft 393:
1.243 ad 394: ksiginfo_queue_init(&kq);
1.79 mycroft 395:
1.277 ad 396: mutex_enter(p->p_lock);
1.243 ad 397: sigclearall(p, NULL, &kq);
1.277 ad 398: mutex_exit(p->p_lock);
1.79 mycroft 399:
1.243 ad 400: ksiginfo_queue_drain(&kq);
1.79 mycroft 401: }
1.202 perry 402:
1.29 cgd 403: /*
1.243 ad 404: * ksiginfo_alloc:
405: *
406: * Allocate a new ksiginfo structure from the pool, and optionally copy
407: * an existing one. If the existing ksiginfo_t is from the pool, and
408: * has not been queued somewhere, then just return it. Additionally,
409: * if the existing ksiginfo_t does not contain any information beyond
410: * the signal number, then just return it.
1.29 cgd 411: */
1.243 ad 412: ksiginfo_t *
413: ksiginfo_alloc(struct proc *p, ksiginfo_t *ok, int flags)
1.48 thorpej 414: {
1.243 ad 415: ksiginfo_t *kp;
1.29 cgd 416:
1.243 ad 417: if (ok != NULL) {
418: if ((ok->ksi_flags & (KSI_QUEUED | KSI_FROMPOOL)) ==
419: KSI_FROMPOOL)
420: return ok;
421: if (KSI_EMPTY_P(ok))
422: return ok;
1.79 mycroft 423: }
1.243 ad 424:
425: kp = pool_get(&ksiginfo_pool, flags);
426: if (kp == NULL) {
427: #ifdef DIAGNOSTIC
428: printf("Out of memory allocating ksiginfo for pid %d\n",
429: p->p_pid);
430: #endif
431: return NULL;
1.79 mycroft 432: }
1.243 ad 433:
434: if (ok != NULL) {
435: memcpy(kp, ok, sizeof(*kp));
436: kp->ksi_flags &= ~KSI_QUEUED;
437: } else
438: KSI_INIT_EMPTY(kp);
439:
440: kp->ksi_flags |= KSI_FROMPOOL;
441:
442: return kp;
1.79 mycroft 443: }
444:
1.243 ad 445: /*
446: * ksiginfo_free:
447: *
448: * If the given ksiginfo_t is from the pool and has not been queued,
449: * then free it.
450: */
1.79 mycroft 451: void
1.243 ad 452: ksiginfo_free(ksiginfo_t *kp)
1.79 mycroft 453: {
1.29 cgd 454:
1.243 ad 455: if ((kp->ksi_flags & (KSI_QUEUED | KSI_FROMPOOL)) != KSI_FROMPOOL)
456: return;
457: pool_put(&ksiginfo_pool, kp);
1.29 cgd 458: }
459:
1.243 ad 460: /*
461: * ksiginfo_queue_drain:
462: *
463: * Drain a non-empty ksiginfo_t queue.
464: */
465: void
466: ksiginfo_queue_drain0(ksiginfoq_t *kq)
1.29 cgd 467: {
1.243 ad 468: ksiginfo_t *ksi;
1.79 mycroft 469:
1.243 ad 470: KASSERT(!CIRCLEQ_EMPTY(kq));
471:
472: while (!CIRCLEQ_EMPTY(kq)) {
473: ksi = CIRCLEQ_FIRST(kq);
474: CIRCLEQ_REMOVE(kq, ksi, ksi_list);
475: pool_put(&ksiginfo_pool, ksi);
476: }
1.79 mycroft 477: }
478:
1.243 ad 479: /*
480: * sigget:
481: *
482: * Fetch the first pending signal from a set. Optionally, also fetch
483: * or manufacture a ksiginfo element. Returns the number of the first
484: * pending signal, or zero.
485: */
486: int
1.270 yamt 487: sigget(sigpend_t *sp, ksiginfo_t *out, int signo, const sigset_t *mask)
1.243 ad 488: {
489: ksiginfo_t *ksi;
490: sigset_t tset;
491:
492: /* If there's no pending set, the signal is from the debugger. */
493: if (sp == NULL) {
494: if (out != NULL) {
495: KSI_INIT(out);
496: out->ksi_info._signo = signo;
497: out->ksi_info._code = SI_USER;
498: }
499: return signo;
500: }
501:
502: /* Construct mask from signo, and 'mask'. */
503: if (signo == 0) {
504: if (mask != NULL) {
505: tset = *mask;
506: __sigandset(&sp->sp_set, &tset);
507: } else
508: tset = sp->sp_set;
509:
510: /* If there are no signals pending, that's it. */
511: if ((signo = firstsig(&tset)) == 0)
512: return 0;
513: } else {
514: KASSERT(sigismember(&sp->sp_set, signo));
515: }
516:
517: sigdelset(&sp->sp_set, signo);
1.29 cgd 518:
1.243 ad 519: /* Find siginfo and copy it out. */
520: CIRCLEQ_FOREACH(ksi, &sp->sp_info, ksi_list) {
521: if (ksi->ksi_signo == signo) {
522: CIRCLEQ_REMOVE(&sp->sp_info, ksi, ksi_list);
523: KASSERT((ksi->ksi_flags & KSI_FROMPOOL) != 0);
524: KASSERT((ksi->ksi_flags & KSI_QUEUED) != 0);
525: ksi->ksi_flags &= ~KSI_QUEUED;
526: if (out != NULL) {
527: memcpy(out, ksi, sizeof(*out));
528: out->ksi_flags &= ~(KSI_FROMPOOL | KSI_QUEUED);
529: }
530: ksiginfo_free(ksi);
531: return signo;
532: }
1.79 mycroft 533: }
534:
1.243 ad 535: /* If there's no siginfo, then manufacture it. */
536: if (out != NULL) {
537: KSI_INIT(out);
538: out->ksi_info._signo = signo;
539: out->ksi_info._code = SI_USER;
540: }
1.202 perry 541:
1.243 ad 542: return signo;
1.29 cgd 543: }
544:
545: /*
1.243 ad 546: * sigput:
547: *
548: * Append a new ksiginfo element to the list of pending ksiginfo's, if
549: * we need to (e.g. SA_SIGINFO was requested).
1.29 cgd 550: */
1.243 ad 551: void
552: sigput(sigpend_t *sp, struct proc *p, ksiginfo_t *ksi)
1.48 thorpej 553: {
1.243 ad 554: ksiginfo_t *kp;
555: struct sigaction *sa = &SIGACTION_PS(p->p_sigacts, ksi->ksi_signo);
556:
1.277 ad 557: KASSERT(mutex_owned(p->p_lock));
1.243 ad 558: KASSERT((ksi->ksi_flags & KSI_QUEUED) == 0);
559:
560: sigaddset(&sp->sp_set, ksi->ksi_signo);
561:
562: /*
563: * If siginfo is not required, or there is none, then just mark the
564: * signal as pending.
565: */
566: if ((sa->sa_flags & SA_SIGINFO) == 0 || KSI_EMPTY_P(ksi))
567: return;
568:
569: KASSERT((ksi->ksi_flags & KSI_FROMPOOL) != 0);
1.79 mycroft 570:
1.243 ad 571: #ifdef notyet /* XXX: QUEUING */
572: if (ksi->ksi_signo < SIGRTMIN)
573: #endif
574: {
575: CIRCLEQ_FOREACH(kp, &sp->sp_info, ksi_list) {
576: if (kp->ksi_signo == ksi->ksi_signo) {
577: KSI_COPY(ksi, kp);
578: kp->ksi_flags |= KSI_QUEUED;
579: return;
580: }
581: }
1.79 mycroft 582: }
583:
1.243 ad 584: ksi->ksi_flags |= KSI_QUEUED;
585: CIRCLEQ_INSERT_TAIL(&sp->sp_info, ksi, ksi_list);
1.79 mycroft 586: }
587:
1.243 ad 588: /*
589: * sigclear:
590: *
591: * Clear all pending signals in the specified set.
592: */
593: void
1.270 yamt 594: sigclear(sigpend_t *sp, const sigset_t *mask, ksiginfoq_t *kq)
1.79 mycroft 595: {
1.243 ad 596: ksiginfo_t *ksi, *next;
1.112 lukem 597:
1.243 ad 598: if (mask == NULL)
599: sigemptyset(&sp->sp_set);
600: else
601: sigminusset(mask, &sp->sp_set);
1.79 mycroft 602:
1.243 ad 603: ksi = CIRCLEQ_FIRST(&sp->sp_info);
604: for (; ksi != (void *)&sp->sp_info; ksi = next) {
605: next = CIRCLEQ_NEXT(ksi, ksi_list);
606: if (mask == NULL || sigismember(mask, ksi->ksi_signo)) {
607: CIRCLEQ_REMOVE(&sp->sp_info, ksi, ksi_list);
608: KASSERT((ksi->ksi_flags & KSI_FROMPOOL) != 0);
609: KASSERT((ksi->ksi_flags & KSI_QUEUED) != 0);
610: CIRCLEQ_INSERT_TAIL(kq, ksi, ksi_list);
1.79 mycroft 611: }
612: }
1.243 ad 613: }
614:
615: /*
616: * sigclearall:
617: *
618: * Clear all pending signals in the specified set from a process and
619: * its LWPs.
620: */
621: void
1.270 yamt 622: sigclearall(struct proc *p, const sigset_t *mask, ksiginfoq_t *kq)
1.243 ad 623: {
624: struct lwp *l;
625:
1.277 ad 626: KASSERT(mutex_owned(p->p_lock));
1.79 mycroft 627:
1.243 ad 628: sigclear(&p->p_sigpend, mask, kq);
629:
630: LIST_FOREACH(l, &p->p_lwps, l_sibling) {
631: sigclear(&l->l_sigpend, mask, kq);
632: }
1.29 cgd 633: }
634:
1.243 ad 635: /*
636: * sigispending:
637: *
638: * Return true if there are pending signals for the current LWP. May
1.269 yamt 639: * be called unlocked provided that LW_PENDSIG is set, and that the
640: * signal has been posted to the appopriate queue before LW_PENDSIG is
1.243 ad 641: * set.
642: */
1.52 christos 643: int
1.243 ad 644: sigispending(struct lwp *l, int signo)
1.48 thorpej 645: {
1.243 ad 646: struct proc *p = l->l_proc;
647: sigset_t tset;
648:
1.260 ad 649: membar_consumer();
1.243 ad 650:
651: tset = l->l_sigpend.sp_set;
652: sigplusset(&p->p_sigpend.sp_set, &tset);
653: sigminusset(&p->p_sigctx.ps_sigignore, &tset);
654: sigminusset(&l->l_sigmask, &tset);
655:
656: if (signo == 0) {
657: if (firstsig(&tset) != 0)
658: return EINTR;
659: } else if (sigismember(&tset, signo))
660: return EINTR;
661:
662: return 0;
663: }
664:
665: /*
666: * siginfo_alloc:
667: *
668: * Allocate a new siginfo_t structure from the pool.
669: */
670: siginfo_t *
671: siginfo_alloc(int flags)
672: {
673:
674: return pool_get(&siginfo_pool, flags);
675: }
676:
677: /*
678: * siginfo_free:
679: *
680: * Return a siginfo_t structure to the pool.
681: */
682: void
683: siginfo_free(void *arg)
684: {
685:
686: pool_put(&siginfo_pool, arg);
687: }
688:
689: void
690: getucontext(struct lwp *l, ucontext_t *ucp)
691: {
692: struct proc *p = l->l_proc;
693:
1.277 ad 694: KASSERT(mutex_owned(p->p_lock));
1.243 ad 695:
696: ucp->uc_flags = 0;
697: ucp->uc_link = l->l_ctxlink;
698:
699: ucp->uc_sigmask = l->l_sigmask;
700: ucp->uc_flags |= _UC_SIGMASK;
701:
702: /*
703: * The (unsupplied) definition of the `current execution stack'
704: * in the System V Interface Definition appears to allow returning
705: * the main context stack.
706: */
707: if ((l->l_sigstk.ss_flags & SS_ONSTACK) == 0) {
1.263 christos 708: ucp->uc_stack.ss_sp = (void *)l->l_proc->p_stackbase;
1.243 ad 709: ucp->uc_stack.ss_size = ctob(l->l_proc->p_vmspace->vm_ssize);
710: ucp->uc_stack.ss_flags = 0; /* XXX, def. is Very Fishy */
711: } else {
712: /* Simply copy alternate signal execution stack. */
713: ucp->uc_stack = l->l_sigstk;
1.79 mycroft 714: }
1.243 ad 715: ucp->uc_flags |= _UC_STACK;
1.277 ad 716: mutex_exit(p->p_lock);
1.243 ad 717: cpu_getmcontext(l, &ucp->uc_mcontext, &ucp->uc_flags);
1.277 ad 718: mutex_enter(p->p_lock);
1.29 cgd 719: }
720:
721: int
1.243 ad 722: setucontext(struct lwp *l, const ucontext_t *ucp)
1.48 thorpej 723: {
1.243 ad 724: struct proc *p = l->l_proc;
1.223 yamt 725: int error;
1.29 cgd 726:
1.277 ad 727: KASSERT(mutex_owned(p->p_lock));
1.243 ad 728:
729: if ((ucp->uc_flags & _UC_SIGMASK) != 0) {
730: error = sigprocmask1(l, SIG_SETMASK, &ucp->uc_sigmask, NULL);
731: if (error != 0)
1.223 yamt 732: return error;
1.29 cgd 733: }
1.243 ad 734:
1.277 ad 735: mutex_exit(p->p_lock);
1.243 ad 736: error = cpu_setmcontext(l, &ucp->uc_mcontext, ucp->uc_flags);
1.277 ad 737: mutex_enter(p->p_lock);
1.243 ad 738: if (error != 0)
739: return (error);
740:
741: l->l_ctxlink = ucp->uc_link;
742:
743: /*
744: * If there was stack information, update whether or not we are
745: * still running on an alternate signal stack.
746: */
747: if ((ucp->uc_flags & _UC_STACK) != 0) {
748: if (ucp->uc_stack.ss_flags & SS_ONSTACK)
749: l->l_sigstk.ss_flags |= SS_ONSTACK;
750: else
751: l->l_sigstk.ss_flags &= ~SS_ONSTACK;
752: }
753:
754: return 0;
1.29 cgd 755: }
756:
757: /*
1.243 ad 758: * Common code for kill process group/broadcast kill. cp is calling
759: * process.
1.29 cgd 760: */
1.52 christos 761: int
1.224 ad 762: killpg1(struct lwp *l, ksiginfo_t *ksi, int pgid, int all)
1.29 cgd 763: {
1.224 ad 764: struct proc *p, *cp;
1.220 elad 765: kauth_cred_t pc;
1.112 lukem 766: struct pgrp *pgrp;
767: int nfound;
1.243 ad 768: int signo = ksi->ksi_signo;
1.202 perry 769:
1.224 ad 770: cp = l->l_proc;
771: pc = l->l_cred;
1.112 lukem 772: nfound = 0;
1.243 ad 773:
1.276 ad 774: mutex_enter(proc_lock);
1.91 thorpej 775: if (all) {
1.202 perry 776: /*
777: * broadcast
1.29 cgd 778: */
1.199 yamt 779: PROCLIST_FOREACH(p, &allproc) {
1.246 pavel 780: if (p->p_pid <= 1 || p->p_flag & PK_SYSTEM || p == cp)
1.29 cgd 781: continue;
1.277 ad 782: mutex_enter(p->p_lock);
1.243 ad 783: if (kauth_authorize_process(pc,
1.264 elad 784: KAUTH_PROCESS_SIGNAL, p, KAUTH_ARG(signo), NULL,
785: NULL) == 0) {
1.243 ad 786: nfound++;
1.277 ad 787: if (signo)
1.243 ad 788: kpsignal2(p, ksi);
789: }
1.277 ad 790: mutex_exit(p->p_lock);
1.29 cgd 791: }
1.91 thorpej 792: } else {
1.202 perry 793: if (pgid == 0)
794: /*
1.29 cgd 795: * zero pgid means send to my process group.
796: */
797: pgrp = cp->p_pgrp;
798: else {
1.243 ad 799: pgrp = pg_find(pgid, PFIND_LOCKED);
1.29 cgd 800: if (pgrp == NULL)
1.243 ad 801: goto out;
1.29 cgd 802: }
1.124 matt 803: LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
1.246 pavel 804: if (p->p_pid <= 1 || p->p_flag & PK_SYSTEM)
1.29 cgd 805: continue;
1.277 ad 806: mutex_enter(p->p_lock);
1.264 elad 807: if (kauth_authorize_process(pc, KAUTH_PROCESS_SIGNAL,
808: p, KAUTH_ARG(signo), NULL, NULL) == 0) {
1.243 ad 809: nfound++;
1.277 ad 810: if (signo && P_ZOMBIE(p) == 0)
811: kpsignal2(p, ksi);
1.243 ad 812: }
1.277 ad 813: mutex_exit(p->p_lock);
1.29 cgd 814: }
815: }
1.243 ad 816: out:
1.276 ad 817: mutex_exit(proc_lock);
1.29 cgd 818: return (nfound ? 0 : ESRCH);
819: }
820:
821: /*
1.243 ad 822: * Send a signal to a process group. If checktty is 1, limit to members
823: * which have a controlling terminal.
1.29 cgd 824: */
825: void
1.243 ad 826: pgsignal(struct pgrp *pgrp, int sig, int checkctty)
1.29 cgd 827: {
1.148 christos 828: ksiginfo_t ksi;
829:
1.276 ad 830: KASSERT(!cpu_intr_p());
831: KASSERT(mutex_owned(proc_lock));
1.29 cgd 832:
1.192 matt 833: KSI_INIT_EMPTY(&ksi);
1.148 christos 834: ksi.ksi_signo = sig;
835: kpgsignal(pgrp, &ksi, NULL, checkctty);
836: }
837:
838: void
839: kpgsignal(struct pgrp *pgrp, ksiginfo_t *ksi, void *data, int checkctty)
1.29 cgd 840: {
1.98 augustss 841: struct proc *p;
1.29 cgd 842:
1.276 ad 843: KASSERT(!cpu_intr_p());
844: KASSERT(mutex_owned(proc_lock));
1.243 ad 845:
1.29 cgd 846: if (pgrp)
1.124 matt 847: LIST_FOREACH(p, &pgrp->pg_members, p_pglist)
1.243 ad 848: if (checkctty == 0 || p->p_lflag & PL_CONTROLT)
1.148 christos 849: kpsignal(p, ksi, data);
1.29 cgd 850: }
851:
852: /*
1.243 ad 853: * Send a signal caused by a trap to the current LWP. If it will be caught
854: * immediately, deliver it with correct code. Otherwise, post it normally.
1.29 cgd 855: */
1.148 christos 856: void
1.243 ad 857: trapsignal(struct lwp *l, ksiginfo_t *ksi)
1.148 christos 858: {
1.130 thorpej 859: struct proc *p;
860: struct sigacts *ps;
1.243 ad 861: int signo = ksi->ksi_signo;
1.29 cgd 862:
1.166 thorpej 863: KASSERT(KSI_TRAP_P(ksi));
864:
1.243 ad 865: ksi->ksi_lid = l->l_lid;
1.130 thorpej 866: p = l->l_proc;
1.243 ad 867:
1.276 ad 868: KASSERT(!cpu_intr_p());
869: mutex_enter(proc_lock);
1.277 ad 870: mutex_enter(p->p_lock);
1.112 lukem 871: ps = p->p_sigacts;
1.243 ad 872: if ((p->p_slflag & PSL_TRACED) == 0 &&
873: sigismember(&p->p_sigctx.ps_sigcatch, signo) &&
874: !sigismember(&l->l_sigmask, signo)) {
1.276 ad 875: mutex_exit(proc_lock);
1.275 ad 876: l->l_ru.ru_nsignals++;
1.243 ad 877: kpsendsig(l, ksi, &l->l_sigmask);
1.277 ad 878: mutex_exit(p->p_lock);
1.255 ad 879: ktrpsig(signo, SIGACTION_PS(ps, signo).sa_handler,
880: &l->l_sigmask, ksi);
1.29 cgd 881: } else {
1.243 ad 882: /* XXX for core dump/debugger */
1.152 christos 883: p->p_sigctx.ps_lwp = l->l_lid;
884: p->p_sigctx.ps_signo = ksi->ksi_signo;
885: p->p_sigctx.ps_code = ksi->ksi_trap;
1.234 yamt 886: kpsignal2(p, ksi);
1.277 ad 887: mutex_exit(p->p_lock);
1.276 ad 888: mutex_exit(proc_lock);
1.29 cgd 889: }
890: }
891:
892: /*
1.151 christos 893: * Fill in signal information and signal the parent for a child status change.
894: */
1.216 christos 895: void
1.243 ad 896: child_psignal(struct proc *p, int mask)
1.151 christos 897: {
898: ksiginfo_t ksi;
1.243 ad 899: struct proc *q;
900: int xstat;
901:
1.276 ad 902: KASSERT(mutex_owned(proc_lock));
1.277 ad 903: KASSERT(mutex_owned(p->p_lock));
1.243 ad 904:
905: xstat = p->p_xstat;
1.151 christos 906:
1.191 matt 907: KSI_INIT(&ksi);
1.151 christos 908: ksi.ksi_signo = SIGCHLD;
1.243 ad 909: ksi.ksi_code = (xstat == SIGCONT ? CLD_CONTINUED : CLD_STOPPED);
1.151 christos 910: ksi.ksi_pid = p->p_pid;
1.220 elad 911: ksi.ksi_uid = kauth_cred_geteuid(p->p_cred);
1.243 ad 912: ksi.ksi_status = xstat;
1.151 christos 913: ksi.ksi_utime = p->p_stats->p_ru.ru_utime.tv_sec;
914: ksi.ksi_stime = p->p_stats->p_ru.ru_stime.tv_sec;
1.243 ad 915:
916: q = p->p_pptr;
917:
1.277 ad 918: mutex_exit(p->p_lock);
919: mutex_enter(q->p_lock);
1.243 ad 920:
921: if ((q->p_sflag & mask) == 0)
922: kpsignal2(q, &ksi);
923:
1.277 ad 924: mutex_exit(q->p_lock);
925: mutex_enter(p->p_lock);
1.151 christos 926: }
927:
1.29 cgd 928: void
1.243 ad 929: psignal(struct proc *p, int signo)
1.148 christos 930: {
1.165 thorpej 931: ksiginfo_t ksi;
932:
1.276 ad 933: KASSERT(!cpu_intr_p());
934: KASSERT(mutex_owned(proc_lock));
1.243 ad 935:
1.192 matt 936: KSI_INIT_EMPTY(&ksi);
1.243 ad 937: ksi.ksi_signo = signo;
1.277 ad 938: mutex_enter(p->p_lock);
1.234 yamt 939: kpsignal2(p, &ksi);
1.277 ad 940: mutex_exit(p->p_lock);
1.148 christos 941: }
942:
943: void
1.234 yamt 944: kpsignal(struct proc *p, ksiginfo_t *ksi, void *data)
1.160 christos 945: {
1.274 ad 946: fdfile_t *ff;
947: file_t *fp;
1.165 thorpej 948:
1.276 ad 949: KASSERT(!cpu_intr_p());
950: KASSERT(mutex_owned(proc_lock));
1.243 ad 951:
952: if ((p->p_sflag & PS_WEXIT) == 0 && data) {
1.160 christos 953: size_t fd;
1.274 ad 954: filedesc_t *fdp = p->p_fd;
1.165 thorpej 955:
1.274 ad 956: /* XXXSMP locking */
1.160 christos 957: ksi->ksi_fd = -1;
958: for (fd = 0; fd < fdp->fd_nfiles; fd++) {
1.274 ad 959: if ((ff = fdp->fd_ofiles[fd]) == NULL)
960: continue;
961: if ((fp = ff->ff_file) == NULL)
962: continue;
963: if (fp->f_data == data) {
1.160 christos 964: ksi->ksi_fd = fd;
965: break;
966: }
967: }
968: }
1.277 ad 969: mutex_enter(p->p_lock);
1.234 yamt 970: kpsignal2(p, ksi);
1.277 ad 971: mutex_exit(p->p_lock);
1.160 christos 972: }
973:
1.243 ad 974: /*
975: * sigismasked:
976: *
977: * Returns true if signal is ignored or masked for the specified LWP.
978: */
979: int
980: sigismasked(struct lwp *l, int sig)
1.29 cgd 981: {
1.243 ad 982: struct proc *p = l->l_proc;
983:
984: return (sigismember(&p->p_sigctx.ps_sigignore, sig) ||
985: sigismember(&l->l_sigmask, sig));
986: }
1.29 cgd 987:
1.243 ad 988: /*
989: * sigpost:
990: *
991: * Post a pending signal to an LWP. Returns non-zero if the LWP was
992: * able to take the signal.
993: */
994: int
995: sigpost(struct lwp *l, sig_t action, int prop, int sig)
996: {
997: int rv, masked;
1.148 christos 998:
1.277 ad 999: KASSERT(mutex_owned(l->l_proc->p_lock));
1.148 christos 1000:
1.183 fvdl 1001: /*
1.243 ad 1002: * If the LWP is on the way out, sigclear() will be busy draining all
1003: * pending signals. Don't give it more.
1.126 jdolecek 1004: */
1.243 ad 1005: if (l->l_refcnt == 0)
1006: return 0;
1007:
1008: lwp_lock(l);
1.126 jdolecek 1009:
1.243 ad 1010: /*
1011: * Have the LWP check for signals. This ensures that even if no LWP
1012: * is found to take the signal immediately, it should be taken soon.
1013: */
1.246 pavel 1014: l->l_flag |= LW_PENDSIG;
1.29 cgd 1015:
1016: /*
1.243 ad 1017: * SIGCONT can be masked, but must always restart stopped LWPs.
1.29 cgd 1018: */
1.243 ad 1019: masked = sigismember(&l->l_sigmask, sig);
1020: if (masked && ((prop & SA_CONT) == 0 || l->l_stat != LSSTOP)) {
1021: lwp_unlock(l);
1022: return 0;
1023: }
1.198 jdolecek 1024:
1.243 ad 1025: /*
1.247 ad 1026: * If killing the process, make it run fast.
1027: */
1028: if (__predict_false((prop & SA_KILL) != 0) &&
1.266 rmind 1029: action == SIG_DFL && l->l_priority < MAXPRI_USER) {
1030: KASSERT(l->l_class == SCHED_OTHER);
1031: lwp_changepri(l, MAXPRI_USER);
1032: }
1.247 ad 1033:
1034: /*
1.243 ad 1035: * If the LWP is running or on a run queue, then we win. If it's
1036: * sleeping interruptably, wake it and make it take the signal. If
1037: * the sleep isn't interruptable, then the chances are it will get
1038: * to see the signal soon anyhow. If suspended, it can't take the
1039: * signal right now. If it's LWP private or for all LWPs, save it
1040: * for later; otherwise punt.
1041: */
1042: rv = 0;
1043:
1044: switch (l->l_stat) {
1045: case LSRUN:
1046: case LSONPROC:
1047: lwp_need_userret(l);
1048: rv = 1;
1049: break;
1050:
1051: case LSSLEEP:
1.246 pavel 1052: if ((l->l_flag & LW_SINTR) != 0) {
1.243 ad 1053: /* setrunnable() will release the lock. */
1054: setrunnable(l);
1055: return 1;
1.232 mrg 1056: }
1.243 ad 1057: break;
1058:
1059: case LSSUSPENDED:
1060: if ((prop & SA_KILL) != 0) {
1061: /* lwp_continue() will release the lock. */
1062: lwp_continue(l);
1063: return 1;
1.190 matt 1064: }
1.243 ad 1065: break;
1066:
1067: case LSSTOP:
1068: if ((prop & SA_STOP) != 0)
1069: break;
1.198 jdolecek 1070:
1071: /*
1.243 ad 1072: * If the LWP is stopped and we are sending a continue
1073: * signal, then start it again.
1.198 jdolecek 1074: */
1.243 ad 1075: if ((prop & SA_CONT) != 0) {
1076: if (l->l_wchan != NULL) {
1077: l->l_stat = LSSLEEP;
1078: l->l_proc->p_nrlwps++;
1079: rv = 1;
1080: break;
1081: }
1082: /* setrunnable() will release the lock. */
1083: setrunnable(l);
1084: return 1;
1.246 pavel 1085: } else if (l->l_wchan == NULL || (l->l_flag & LW_SINTR) != 0) {
1.243 ad 1086: /* setrunnable() will release the lock. */
1087: setrunnable(l);
1088: return 1;
1089: }
1090: break;
1.198 jdolecek 1091:
1.243 ad 1092: default:
1093: break;
1094: }
1.44 mycroft 1095:
1.243 ad 1096: lwp_unlock(l);
1097: return rv;
1098: }
1.29 cgd 1099:
1.243 ad 1100: /*
1101: * Notify an LWP that it has a pending signal.
1102: */
1103: void
1104: signotify(struct lwp *l)
1105: {
1.250 ad 1106: KASSERT(lwp_locked(l, NULL));
1.29 cgd 1107:
1.246 pavel 1108: l->l_flag |= LW_PENDSIG;
1.243 ad 1109: lwp_need_userret(l);
1110: }
1.44 mycroft 1111:
1.243 ad 1112: /*
1113: * Find an LWP within process p that is waiting on signal ksi, and hand
1114: * it on.
1115: */
1116: int
1117: sigunwait(struct proc *p, const ksiginfo_t *ksi)
1118: {
1119: struct lwp *l;
1120: int signo;
1.135 jdolecek 1121:
1.277 ad 1122: KASSERT(mutex_owned(p->p_lock));
1.171 jdolecek 1123:
1.243 ad 1124: signo = ksi->ksi_signo;
1125:
1126: if (ksi->ksi_lid != 0) {
1127: /*
1128: * Signal came via _lwp_kill(). Find the LWP and see if
1129: * it's interested.
1130: */
1131: if ((l = lwp_find(p, ksi->ksi_lid)) == NULL)
1132: return 0;
1133: if (l->l_sigwaited == NULL ||
1134: !sigismember(&l->l_sigwaitset, signo))
1135: return 0;
1136: } else {
1137: /*
1138: * Look for any LWP that may be interested.
1139: */
1140: LIST_FOREACH(l, &p->p_sigwaiters, l_sigwaiter) {
1141: KASSERT(l->l_sigwaited != NULL);
1142: if (sigismember(&l->l_sigwaitset, signo))
1143: break;
1144: }
1145: }
1146:
1147: if (l != NULL) {
1148: l->l_sigwaited->ksi_info = ksi->ksi_info;
1149: l->l_sigwaited = NULL;
1150: LIST_REMOVE(l, l_sigwaiter);
1151: cv_signal(&l->l_sigcv);
1152: return 1;
1153: }
1154:
1155: return 0;
1156: }
1157:
1158: /*
1159: * Send the signal to the process. If the signal has an action, the action
1160: * is usually performed by the target process rather than the caller; we add
1161: * the signal to the set of pending signals for the process.
1162: *
1163: * Exceptions:
1164: * o When a stop signal is sent to a sleeping process that takes the
1165: * default action, the process is stopped without awakening it.
1166: * o SIGCONT restarts stopped processes (or puts them back to sleep)
1167: * regardless of the signal action (eg, blocked or ignored).
1168: *
1169: * Other ignored signals are discarded immediately.
1170: */
1171: void
1172: kpsignal2(struct proc *p, ksiginfo_t *ksi)
1173: {
1174: int prop, lid, toall, signo = ksi->ksi_signo;
1.259 ad 1175: struct sigacts *sa;
1.243 ad 1176: struct lwp *l;
1177: ksiginfo_t *kp;
1178: ksiginfoq_t kq;
1179: sig_t action;
1180:
1.276 ad 1181: KASSERT(!cpu_intr_p());
1182: KASSERT(mutex_owned(proc_lock));
1.277 ad 1183: KASSERT(mutex_owned(p->p_lock));
1.243 ad 1184: KASSERT((ksi->ksi_flags & KSI_QUEUED) == 0);
1185: KASSERT(signo > 0 && signo < NSIG);
1.171 jdolecek 1186:
1.135 jdolecek 1187: /*
1.243 ad 1188: * If the process is being created by fork, is a zombie or is
1189: * exiting, then just drop the signal here and bail out.
1.29 cgd 1190: */
1.243 ad 1191: if (p->p_stat != SACTIVE && p->p_stat != SSTOP)
1.231 mrg 1192: return;
1193:
1194: /*
1.243 ad 1195: * Notify any interested parties of the signal.
1196: */
1197: KNOTE(&p->p_klist, NOTE_SIGNAL | signo);
1198:
1199: /*
1200: * Some signals including SIGKILL must act on the entire process.
1.231 mrg 1201: */
1.243 ad 1202: kp = NULL;
1203: prop = sigprop[signo];
1204: toall = ((prop & SA_TOALL) != 0);
1205:
1206: if (toall)
1207: lid = 0;
1208: else
1209: lid = ksi->ksi_lid;
1.231 mrg 1210:
1.243 ad 1211: /*
1212: * If proc is traced, always give parent a chance.
1213: */
1214: if (p->p_slflag & PSL_TRACED) {
1215: action = SIG_DFL;
1.104 thorpej 1216:
1.243 ad 1217: if (lid == 0) {
1218: /*
1219: * If the process is being traced and the signal
1220: * is being caught, make sure to save any ksiginfo.
1221: */
1222: if ((kp = ksiginfo_alloc(p, ksi, PR_NOWAIT)) == NULL)
1223: return;
1224: sigput(&p->p_sigpend, p, kp);
1225: }
1226: } else {
1227: /*
1228: * If the signal was the result of a trap and is not being
1229: * caught, then reset it to default action so that the
1230: * process dumps core immediately.
1231: */
1232: if (KSI_TRAP_P(ksi)) {
1.259 ad 1233: sa = p->p_sigacts;
1234: mutex_enter(&sa->sa_mutex);
1.243 ad 1235: if (!sigismember(&p->p_sigctx.ps_sigcatch, signo)) {
1236: sigdelset(&p->p_sigctx.ps_sigignore, signo);
1237: SIGACTION(p, signo).sa_handler = SIG_DFL;
1.187 cl 1238: }
1.259 ad 1239: mutex_exit(&sa->sa_mutex);
1.175 cl 1240: }
1.243 ad 1241:
1.29 cgd 1242: /*
1.243 ad 1243: * If the signal is being ignored, then drop it. Note: we
1244: * don't set SIGCONT in ps_sigignore, and if it is set to
1245: * SIG_IGN, action will be SIG_DFL here.
1.29 cgd 1246: */
1.243 ad 1247: if (sigismember(&p->p_sigctx.ps_sigignore, signo))
1248: return;
1249:
1250: else if (sigismember(&p->p_sigctx.ps_sigcatch, signo))
1251: action = SIG_CATCH;
1252: else {
1253: action = SIG_DFL;
1254:
1255: /*
1256: * If sending a tty stop signal to a member of an
1257: * orphaned process group, discard the signal here if
1258: * the action is default; don't stop the process below
1259: * if sleeping, and don't clear any pending SIGCONT.
1260: */
1.276 ad 1261: if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0)
1.243 ad 1262: return;
1263:
1264: if (prop & SA_KILL && p->p_nice > NZERO)
1265: p->p_nice = NZERO;
1.29 cgd 1266: }
1.175 cl 1267: }
1268:
1.243 ad 1269: /*
1270: * If stopping or continuing a process, discard any pending
1271: * signals that would do the inverse.
1272: */
1273: if ((prop & (SA_CONT | SA_STOP)) != 0) {
1274: ksiginfo_queue_init(&kq);
1275: if ((prop & SA_CONT) != 0)
1276: sigclear(&p->p_sigpend, &stopsigmask, &kq);
1277: if ((prop & SA_STOP) != 0)
1278: sigclear(&p->p_sigpend, &contsigmask, &kq);
1279: ksiginfo_queue_drain(&kq); /* XXXSMP */
1280: }
1281:
1282: /*
1283: * If the signal doesn't have SA_CANTMASK (no override for SIGKILL,
1284: * please!), check if any LWPs are waiting on it. If yes, pass on
1285: * the signal info. The signal won't be processed further here.
1286: */
1287: if ((prop & SA_CANTMASK) == 0 && !LIST_EMPTY(&p->p_sigwaiters) &&
1288: p->p_stat == SACTIVE && (p->p_sflag & PS_STOPPING) == 0 &&
1289: sigunwait(p, ksi))
1290: return;
1291:
1292: /*
1293: * XXXSMP Should be allocated by the caller, we're holding locks
1294: * here.
1295: */
1296: if (kp == NULL && (kp = ksiginfo_alloc(p, ksi, PR_NOWAIT)) == NULL)
1297: return;
1298:
1299: /*
1300: * LWP private signals are easy - just find the LWP and post
1301: * the signal to it.
1302: */
1303: if (lid != 0) {
1304: l = lwp_find(p, lid);
1305: if (l != NULL) {
1306: sigput(&l->l_sigpend, p, kp);
1.260 ad 1307: membar_producer();
1.243 ad 1308: (void)sigpost(l, action, prop, kp->ksi_signo);
1309: }
1310: goto out;
1311: }
1.130 thorpej 1312:
1.243 ad 1313: /*
1.250 ad 1314: * Some signals go to all LWPs, even if posted with _lwp_kill().
1.243 ad 1315: */
1316: if (p->p_stat == SACTIVE && (p->p_sflag & PS_STOPPING) == 0) {
1317: if ((p->p_slflag & PSL_TRACED) != 0)
1318: goto deliver;
1.202 perry 1319:
1.176 cl 1320: /*
1321: * If SIGCONT is default (or ignored) and process is
1322: * asleep, we are finished; the process should not
1323: * be awakened.
1324: */
1.243 ad 1325: if ((prop & SA_CONT) != 0 && action == SIG_DFL)
1326: goto out;
1.176 cl 1327:
1.273 yamt 1328: sigput(&p->p_sigpend, p, kp);
1.243 ad 1329: } else {
1.176 cl 1330: /*
1.250 ad 1331: * Process is stopped or stopping. If traced, then no
1332: * further action is necessary.
1.176 cl 1333: */
1.243 ad 1334: if ((p->p_slflag & PSL_TRACED) != 0 && signo != SIGKILL)
1335: goto out;
1.29 cgd 1336:
1.243 ad 1337: if ((prop & (SA_CONT | SA_KILL)) != 0) {
1338: /*
1339: * Re-adjust p_nstopchild if the process wasn't
1340: * collected by its parent.
1341: */
1342: p->p_stat = SACTIVE;
1343: p->p_sflag &= ~PS_STOPPING;
1344: if (!p->p_waited)
1345: p->p_pptr->p_nstopchild--;
1.202 perry 1346:
1.29 cgd 1347: /*
1.243 ad 1348: * If SIGCONT is default (or ignored), we continue
1349: * the process but don't leave the signal in
1350: * ps_siglist, as it has no further action. If
1351: * SIGCONT is held, we continue the process and
1352: * leave the signal in ps_siglist. If the process
1353: * catches SIGCONT, let it handle the signal itself.
1354: * If it isn't waiting on an event, then it goes
1355: * back to run state. Otherwise, process goes back
1356: * to sleep state.
1.29 cgd 1357: */
1.243 ad 1358: if ((prop & SA_CONT) == 0 || action != SIG_DFL)
1359: sigput(&p->p_sigpend, p, kp);
1360: } else if ((prop & SA_STOP) != 0) {
1.29 cgd 1361: /*
1.176 cl 1362: * Already stopped, don't need to stop again.
1363: * (If we did the shell could get confused.)
1.29 cgd 1364: */
1.243 ad 1365: goto out;
1366: } else
1367: sigput(&p->p_sigpend, p, kp);
1368: }
1.176 cl 1369:
1.243 ad 1370: deliver:
1371: /*
1.271 yamt 1372: * Before we set LW_PENDSIG on any LWP, ensure that the signal is
1.243 ad 1373: * visible on the per process list (for sigispending()). This
1374: * is unlikely to be needed in practice, but...
1375: */
1.260 ad 1376: membar_producer();
1.29 cgd 1377:
1378: /*
1.243 ad 1379: * Try to find an LWP that can take the signal.
1.29 cgd 1380: */
1.243 ad 1381: LIST_FOREACH(l, &p->p_lwps, l_sibling)
1382: if (sigpost(l, action, prop, kp->ksi_signo) && !toall)
1383: break;
1.202 perry 1384:
1.112 lukem 1385: out:
1.243 ad 1386: /*
1.250 ad 1387: * If the ksiginfo wasn't used, then bin it. XXXSMP freeing memory
1388: * with locks held. The caller should take care of this.
1.243 ad 1389: */
1390: ksiginfo_free(kp);
1.29 cgd 1391: }
1392:
1.243 ad 1393: void
1394: kpsendsig(struct lwp *l, const ksiginfo_t *ksi, const sigset_t *mask)
1.209 chs 1395: {
1.243 ad 1396: struct proc *p = l->l_proc;
1397:
1.277 ad 1398: KASSERT(mutex_owned(p->p_lock));
1.209 chs 1399:
1.243 ad 1400: (*p->p_emul->e_sendsig)(ksi, mask);
1.209 chs 1401: }
1402:
1.243 ad 1403: /*
1.272 yamt 1404: * Stop any LWPs sleeping interruptably.
1405: */
1406: static void
1407: proc_stop_lwps(struct proc *p)
1408: {
1409: struct lwp *l;
1410:
1.277 ad 1411: KASSERT(mutex_owned(p->p_lock));
1.272 yamt 1412: KASSERT((p->p_sflag & PS_STOPPING) != 0);
1413:
1414: LIST_FOREACH(l, &p->p_lwps, l_sibling) {
1415: lwp_lock(l);
1416: if (l->l_stat == LSSLEEP && (l->l_flag & LW_SINTR) != 0) {
1417: l->l_stat = LSSTOP;
1418: p->p_nrlwps--;
1419: }
1420: lwp_unlock(l);
1421: }
1422: }
1423:
1424: /*
1425: * Finish stopping of a process. Mark it stopped and notify the parent.
1426: *
1.277 ad 1427: * Drop p_lock briefly if PS_NOTIFYSTOP is set and ppsig is true.
1.272 yamt 1428: */
1429: static void
1430: proc_stop_done(struct proc *p, bool ppsig, int ppmask)
1431: {
1432:
1.276 ad 1433: KASSERT(mutex_owned(proc_lock));
1.277 ad 1434: KASSERT(mutex_owned(p->p_lock));
1.272 yamt 1435: KASSERT((p->p_sflag & PS_STOPPING) != 0);
1436: KASSERT(p->p_nrlwps == 0 || (p->p_nrlwps == 1 && p == curproc));
1437:
1438: p->p_sflag &= ~PS_STOPPING;
1439: p->p_stat = SSTOP;
1440: p->p_waited = 0;
1441: p->p_pptr->p_nstopchild++;
1442: if ((p->p_sflag & PS_NOTIFYSTOP) != 0) {
1443: if (ppsig) {
1.277 ad 1444: /* child_psignal drops p_lock briefly. */
1.272 yamt 1445: child_psignal(p, ppmask);
1446: }
1447: cv_broadcast(&p->p_pptr->p_waitcv);
1448: }
1449: }
1450:
1451: /*
1.243 ad 1452: * Stop the current process and switch away when being stopped or traced.
1453: */
1.209 chs 1454: void
1.248 thorpej 1455: sigswitch(bool ppsig, int ppmask, int signo)
1.209 chs 1456: {
1.272 yamt 1457: struct lwp *l = curlwp;
1.243 ad 1458: struct proc *p = l->l_proc;
1.245 ad 1459: #ifdef MULTIPROCESSOR
1460: int biglocks;
1461: #endif
1.243 ad 1462:
1.277 ad 1463: KASSERT(mutex_owned(p->p_lock));
1.250 ad 1464: KASSERT(l->l_stat == LSONPROC);
1465: KASSERT(p->p_nrlwps > 0);
1.243 ad 1466:
1467: /*
1468: * On entry we know that the process needs to stop. If it's
1469: * the result of a 'sideways' stop signal that has been sourced
1470: * through issignal(), then stop other LWPs in the process too.
1471: */
1472: if (p->p_stat == SACTIVE && (p->p_sflag & PS_STOPPING) == 0) {
1473: KASSERT(signo != 0);
1.272 yamt 1474: proc_stop(p, 1, signo);
1.250 ad 1475: KASSERT(p->p_nrlwps > 0);
1.243 ad 1476: }
1477:
1478: /*
1479: * If we are the last live LWP, and the stop was a result of
1480: * a new signal, then signal the parent.
1481: */
1482: if ((p->p_sflag & PS_STOPPING) != 0) {
1.276 ad 1483: if (!mutex_tryenter(proc_lock)) {
1.277 ad 1484: mutex_exit(p->p_lock);
1.276 ad 1485: mutex_enter(proc_lock);
1.277 ad 1486: mutex_enter(p->p_lock);
1.243 ad 1487: }
1488:
1489: if (p->p_nrlwps == 1 && (p->p_sflag & PS_STOPPING) != 0) {
1.272 yamt 1490: /*
1491: * Note that proc_stop_done() can drop
1.277 ad 1492: * p->p_lock briefly.
1.272 yamt 1493: */
1494: proc_stop_done(p, ppsig, ppmask);
1.243 ad 1495: }
1496:
1.276 ad 1497: mutex_exit(proc_lock);
1.243 ad 1498: }
1499:
1500: /*
1501: * Unlock and switch away.
1502: */
1.245 ad 1503: KERNEL_UNLOCK_ALL(l, &biglocks);
1.243 ad 1504: if (p->p_stat == SSTOP || (p->p_sflag & PS_STOPPING) != 0) {
1505: p->p_nrlwps--;
1506: lwp_lock(l);
1507: KASSERT(l->l_stat == LSONPROC || l->l_stat == LSSLEEP);
1508: l->l_stat = LSSTOP;
1509: lwp_unlock(l);
1510: }
1511:
1.277 ad 1512: mutex_exit(p->p_lock);
1.243 ad 1513: lwp_lock(l);
1.253 yamt 1514: mi_switch(l);
1.245 ad 1515: KERNEL_LOCK(biglocks, l);
1.277 ad 1516: mutex_enter(p->p_lock);
1.209 chs 1517: }
1518:
1.243 ad 1519: /*
1520: * Check for a signal from the debugger.
1521: */
1522: int
1523: sigchecktrace(sigpend_t **spp)
1.130 thorpej 1524: {
1.243 ad 1525: struct lwp *l = curlwp;
1.130 thorpej 1526: struct proc *p = l->l_proc;
1.243 ad 1527: int signo;
1528:
1.277 ad 1529: KASSERT(mutex_owned(p->p_lock));
1.130 thorpej 1530:
1.243 ad 1531: /*
1532: * If we are no longer being traced, or the parent didn't
1533: * give us a signal, look for more signals.
1534: */
1535: if ((p->p_slflag & PSL_TRACED) == 0 || p->p_xstat == 0)
1536: return 0;
1.130 thorpej 1537:
1.243 ad 1538: /* If there's a pending SIGKILL, process it immediately. */
1539: if (sigismember(&p->p_sigpend.sp_set, SIGKILL))
1540: return 0;
1.79 mycroft 1541:
1.243 ad 1542: /*
1543: * If the new signal is being masked, look for other signals.
1544: * `p->p_sigctx.ps_siglist |= mask' is done in setrunnable().
1545: */
1546: signo = p->p_xstat;
1547: p->p_xstat = 0;
1548: if ((sigprop[signo] & SA_TOLWP) != 0)
1549: *spp = &l->l_sigpend;
1550: else
1551: *spp = &p->p_sigpend;
1552: if (sigismember(&l->l_sigmask, signo))
1553: signo = 0;
1.79 mycroft 1554:
1.243 ad 1555: return signo;
1.79 mycroft 1556: }
1557:
1.29 cgd 1558: /*
1559: * If the current process has received a signal (should be caught or cause
1560: * termination, should interrupt current syscall), return the signal number.
1.243 ad 1561: *
1.29 cgd 1562: * Stop signals with default action are processed immediately, then cleared;
1563: * they aren't returned. This is checked after each entry to the system for
1.243 ad 1564: * a syscall or trap.
1565: *
1566: * We will also return -1 if the process is exiting and the current LWP must
1567: * follow suit.
1.29 cgd 1568: *
1.243 ad 1569: * Note that we may be called while on a sleep queue, so MUST NOT sleep. We
1570: * can switch away, though.
1.29 cgd 1571: */
1572: int
1.130 thorpej 1573: issignal(struct lwp *l)
1.29 cgd 1574: {
1.243 ad 1575: struct proc *p = l->l_proc;
1576: int signo = 0, prop;
1577: sigpend_t *sp = NULL;
1578: sigset_t ss;
1579:
1.277 ad 1580: KASSERT(mutex_owned(p->p_lock));
1.29 cgd 1581:
1.243 ad 1582: for (;;) {
1583: /* Discard any signals that we have decided not to take. */
1584: if (signo != 0)
1585: (void)sigget(sp, NULL, signo, NULL);
1.144 fvdl 1586:
1.243 ad 1587: /*
1588: * If the process is stopped/stopping, then stop ourselves
1589: * now that we're on the kernel/userspace boundary. When
1590: * we awaken, check for a signal from the debugger.
1591: */
1592: if (p->p_stat == SSTOP || (p->p_sflag & PS_STOPPING) != 0) {
1.249 thorpej 1593: sigswitch(true, PS_NOCLDSTOP, 0);
1.243 ad 1594: signo = sigchecktrace(&sp);
1595: } else
1596: signo = 0;
1.238 ad 1597:
1.130 thorpej 1598: /*
1.243 ad 1599: * If the debugger didn't provide a signal, find a pending
1600: * signal from our set. Check per-LWP signals first, and
1601: * then per-process.
1602: */
1603: if (signo == 0) {
1604: sp = &l->l_sigpend;
1605: ss = sp->sp_set;
1606: if ((p->p_sflag & PS_PPWAIT) != 0)
1607: sigminusset(&stopsigmask, &ss);
1608: sigminusset(&l->l_sigmask, &ss);
1609:
1610: if ((signo = firstsig(&ss)) == 0) {
1611: sp = &p->p_sigpend;
1612: ss = sp->sp_set;
1613: if ((p->p_sflag & PS_PPWAIT) != 0)
1614: sigminusset(&stopsigmask, &ss);
1615: sigminusset(&l->l_sigmask, &ss);
1616:
1617: if ((signo = firstsig(&ss)) == 0) {
1618: /*
1619: * No signal pending - clear the
1620: * indicator and bail out.
1621: */
1622: lwp_lock(l);
1.246 pavel 1623: l->l_flag &= ~LW_PENDSIG;
1.243 ad 1624: lwp_unlock(l);
1625: sp = NULL;
1626: break;
1627: }
1628: }
1.79 mycroft 1629: }
1.42 mycroft 1630:
1.29 cgd 1631: /*
1.243 ad 1632: * We should see pending but ignored signals only if
1633: * we are being traced.
1.29 cgd 1634: */
1.243 ad 1635: if (sigismember(&p->p_sigctx.ps_sigignore, signo) &&
1636: (p->p_slflag & PSL_TRACED) == 0) {
1637: /* Discard the signal. */
1.29 cgd 1638: continue;
1.243 ad 1639: }
1.42 mycroft 1640:
1.243 ad 1641: /*
1642: * If traced, always stop, and stay stopped until released
1643: * by the debugger. If the our parent process is waiting
1644: * for us, don't hang as we could deadlock.
1645: */
1646: if ((p->p_slflag & PSL_TRACED) != 0 &&
1647: (p->p_sflag & PS_PPWAIT) == 0 && signo != SIGKILL) {
1648: /* Take the signal. */
1649: (void)sigget(sp, NULL, signo, NULL);
1650: p->p_xstat = signo;
1.184 manu 1651:
1652: /* Emulation-specific handling of signal trace */
1.243 ad 1653: if (p->p_emul->e_tracesig == NULL ||
1654: (*p->p_emul->e_tracesig)(p, signo) == 0)
1655: sigswitch(!(p->p_slflag & PSL_FSTRACE), 0,
1656: signo);
1.29 cgd 1657:
1.243 ad 1658: /* Check for a signal from the debugger. */
1659: if ((signo = sigchecktrace(&sp)) == 0)
1.29 cgd 1660: continue;
1661: }
1662:
1.243 ad 1663: prop = sigprop[signo];
1.42 mycroft 1664:
1.29 cgd 1665: /*
1666: * Decide whether the signal should be returned.
1667: */
1.243 ad 1668: switch ((long)SIGACTION(p, signo).sa_handler) {
1.33 cgd 1669: case (long)SIG_DFL:
1.29 cgd 1670: /*
1671: * Don't take default actions on system processes.
1672: */
1673: if (p->p_pid <= 1) {
1674: #ifdef DIAGNOSTIC
1675: /*
1676: * Are you sure you want to ignore SIGSEGV
1677: * in init? XXX
1678: */
1.243 ad 1679: printf_nolog("Process (pid %d) got sig %d\n",
1680: p->p_pid, signo);
1.29 cgd 1681: #endif
1.243 ad 1682: continue;
1.29 cgd 1683: }
1.243 ad 1684:
1.29 cgd 1685: /*
1.243 ad 1686: * If there is a pending stop signal to process with
1687: * default action, stop here, then clear the signal.
1688: * However, if process is member of an orphaned
1.29 cgd 1689: * process group, ignore tty stop signals.
1690: */
1691: if (prop & SA_STOP) {
1.276 ad 1692: /*
1693: * XXX Don't hold proc_lock for p_lflag,
1694: * but it's not a big deal.
1695: */
1.243 ad 1696: if (p->p_slflag & PSL_TRACED ||
1.276 ad 1697: ((p->p_lflag & PL_ORPHANPG) != 0 &&
1.243 ad 1698: prop & SA_TTYSTOP)) {
1699: /* Ignore the signal. */
1700: continue;
1701: }
1702: /* Take the signal. */
1703: (void)sigget(sp, NULL, signo, NULL);
1704: p->p_xstat = signo;
1705: signo = 0;
1.249 thorpej 1706: sigswitch(true, PS_NOCLDSTOP, p->p_xstat);
1.29 cgd 1707: } else if (prop & SA_IGNORE) {
1708: /*
1709: * Except for SIGCONT, shouldn't get here.
1710: * Default action is to ignore; drop it.
1711: */
1.243 ad 1712: continue;
1713: }
1714: break;
1.29 cgd 1715:
1.33 cgd 1716: case (long)SIG_IGN:
1.243 ad 1717: #ifdef DEBUG_ISSIGNAL
1.29 cgd 1718: /*
1719: * Masking above should prevent us ever trying
1720: * to take action on an ignored signal other
1721: * than SIGCONT, unless process is traced.
1722: */
1723: if ((prop & SA_CONT) == 0 &&
1.243 ad 1724: (p->p_slflag & PSL_TRACED) == 0)
1725: printf_nolog("issignal\n");
1.128 jdolecek 1726: #endif
1.243 ad 1727: continue;
1.29 cgd 1728:
1729: default:
1730: /*
1.243 ad 1731: * This signal has an action, let postsig() process
1732: * it.
1.29 cgd 1733: */
1.243 ad 1734: break;
1.29 cgd 1735: }
1.243 ad 1736:
1737: break;
1.29 cgd 1738: }
1.42 mycroft 1739:
1.243 ad 1740: l->l_sigpendset = sp;
1741: return signo;
1.29 cgd 1742: }
1743:
1744: /*
1.243 ad 1745: * Take the action for the specified signal
1746: * from the current set of pending signals.
1.29 cgd 1747: */
1.179 christos 1748: void
1.243 ad 1749: postsig(int signo)
1.29 cgd 1750: {
1.243 ad 1751: struct lwp *l;
1752: struct proc *p;
1753: struct sigacts *ps;
1754: sig_t action;
1755: sigset_t *returnmask;
1756: ksiginfo_t ksi;
1757:
1758: l = curlwp;
1759: p = l->l_proc;
1760: ps = p->p_sigacts;
1761:
1.277 ad 1762: KASSERT(mutex_owned(p->p_lock));
1.243 ad 1763: KASSERT(signo > 0);
1764:
1765: /*
1766: * Set the new mask value and also defer further occurrences of this
1767: * signal.
1768: *
1.268 yamt 1769: * Special case: user has done a sigsuspend. Here the current mask is
1770: * not of interest, but rather the mask from before the sigsuspen is
1.243 ad 1771: * what we want restored after the signal processing is completed.
1772: */
1773: if (l->l_sigrestore) {
1774: returnmask = &l->l_sigoldmask;
1775: l->l_sigrestore = 0;
1776: } else
1777: returnmask = &l->l_sigmask;
1.29 cgd 1778:
1.243 ad 1779: /*
1780: * Commit to taking the signal before releasing the mutex.
1781: */
1782: action = SIGACTION_PS(ps, signo).sa_handler;
1.275 ad 1783: l->l_ru.ru_nsignals++;
1.243 ad 1784: sigget(l->l_sigpendset, &ksi, signo, NULL);
1.104 thorpej 1785:
1.255 ad 1786: if (ktrpoint(KTR_PSIG)) {
1.277 ad 1787: mutex_exit(p->p_lock);
1.255 ad 1788: ktrpsig(signo, action, returnmask, NULL);
1.277 ad 1789: mutex_enter(p->p_lock);
1.243 ad 1790: }
1.130 thorpej 1791:
1.243 ad 1792: if (action == SIG_DFL) {
1.175 cl 1793: /*
1.243 ad 1794: * Default action, where the default is to kill
1795: * the process. (Other cases were ignored above.)
1.175 cl 1796: */
1.243 ad 1797: sigexit(l, signo);
1798: return;
1.175 cl 1799: }
1800:
1.202 perry 1801: /*
1.243 ad 1802: * If we get here, the signal must be caught.
1.130 thorpej 1803: */
1804: #ifdef DIAGNOSTIC
1.243 ad 1805: if (action == SIG_IGN || sigismember(&l->l_sigmask, signo))
1806: panic("postsig action");
1.130 thorpej 1807: #endif
1.144 fvdl 1808:
1.243 ad 1809: kpsendsig(l, &ksi, returnmask);
1.29 cgd 1810: }
1811:
1.133 nathanw 1812: /*
1.243 ad 1813: * sendsig_reset:
1.133 nathanw 1814: *
1.243 ad 1815: * Reset the signal action. Called from emulation specific sendsig()
1816: * before unlocking to deliver the signal.
1.29 cgd 1817: */
1818: void
1.243 ad 1819: sendsig_reset(struct lwp *l, int signo)
1.29 cgd 1820: {
1.243 ad 1821: struct proc *p = l->l_proc;
1822: struct sigacts *ps = p->p_sigacts;
1.29 cgd 1823:
1.277 ad 1824: KASSERT(mutex_owned(p->p_lock));
1.106 thorpej 1825:
1.243 ad 1826: p->p_sigctx.ps_lwp = 0;
1827: p->p_sigctx.ps_code = 0;
1828: p->p_sigctx.ps_signo = 0;
1829:
1.259 ad 1830: mutex_enter(&ps->sa_mutex);
1.243 ad 1831: sigplusset(&SIGACTION_PS(ps, signo).sa_mask, &l->l_sigmask);
1832: if (SIGACTION_PS(ps, signo).sa_flags & SA_RESETHAND) {
1833: sigdelset(&p->p_sigctx.ps_sigcatch, signo);
1834: if (signo != SIGCONT && sigprop[signo] & SA_IGNORE)
1835: sigaddset(&p->p_sigctx.ps_sigignore, signo);
1836: SIGACTION_PS(ps, signo).sa_handler = SIG_DFL;
1.29 cgd 1837: }
1.259 ad 1838: mutex_exit(&ps->sa_mutex);
1.29 cgd 1839: }
1840:
1841: /*
1842: * Kill the current process for stated reason.
1843: */
1.52 christos 1844: void
1.122 manu 1845: killproc(struct proc *p, const char *why)
1.29 cgd 1846: {
1.276 ad 1847:
1848: KASSERT(mutex_owned(proc_lock));
1849:
1.29 cgd 1850: log(LOG_ERR, "pid %d was killed: %s\n", p->p_pid, why);
1.243 ad 1851: uprintf_locked("sorry, pid %d was killed: %s\n", p->p_pid, why);
1.29 cgd 1852: psignal(p, SIGKILL);
1853: }
1854:
1855: /*
1856: * Force the current process to exit with the specified signal, dumping core
1.243 ad 1857: * if appropriate. We bypass the normal tests for masked and caught
1858: * signals, allowing unrecoverable failures to terminate the process without
1859: * changing signal state. Mark the accounting record with the signal
1860: * termination. If dumping core, save the signal number for the debugger.
1861: * Calls exit and does not return.
1.29 cgd 1862: */
1.243 ad 1863: void
1864: sigexit(struct lwp *l, int signo)
1865: {
1866: int exitsig, error, docore;
1867: struct proc *p;
1868: struct lwp *t;
1.96 fair 1869:
1.243 ad 1870: p = l->l_proc;
1.96 fair 1871:
1.277 ad 1872: KASSERT(mutex_owned(p->p_lock));
1.243 ad 1873: KERNEL_UNLOCK_ALL(l, NULL);
1.96 fair 1874:
1.243 ad 1875: /*
1876: * Don't permit coredump() multiple times in the same process.
1877: * Call back into sigexit, where we will be suspended until
1878: * the deed is done. Note that this is a recursive call, but
1.246 pavel 1879: * LW_WCORE will prevent us from coming back this way.
1.243 ad 1880: */
1881: if ((p->p_sflag & PS_WCORE) != 0) {
1882: lwp_lock(l);
1.246 pavel 1883: l->l_flag |= (LW_WCORE | LW_WEXIT | LW_WSUSPEND);
1.243 ad 1884: lwp_unlock(l);
1.277 ad 1885: mutex_exit(p->p_lock);
1.243 ad 1886: lwp_userret(l);
1887: #ifdef DIAGNOSTIC
1888: panic("sigexit");
1889: #endif
1890: /* NOTREACHED */
1891: }
1.130 thorpej 1892:
1893: /*
1.243 ad 1894: * Prepare all other LWPs for exit. If dumping core, suspend them
1895: * so that their registers are available long enough to be dumped.
1896: */
1897: if ((docore = (sigprop[signo] & SA_CORE)) != 0) {
1898: p->p_sflag |= PS_WCORE;
1899: for (;;) {
1900: LIST_FOREACH(t, &p->p_lwps, l_sibling) {
1901: lwp_lock(t);
1902: if (t == l) {
1.246 pavel 1903: t->l_flag &= ~LW_WSUSPEND;
1.243 ad 1904: lwp_unlock(t);
1905: continue;
1906: }
1.246 pavel 1907: t->l_flag |= (LW_WCORE | LW_WEXIT);
1.243 ad 1908: lwp_suspend(l, t);
1909: }
1.130 thorpej 1910:
1.243 ad 1911: if (p->p_nrlwps == 1)
1912: break;
1.130 thorpej 1913:
1.243 ad 1914: /*
1915: * Kick any LWPs sitting in lwp_wait1(), and wait
1916: * for everyone else to stop before proceeding.
1917: */
1918: p->p_nlwpwait++;
1919: cv_broadcast(&p->p_lwpcv);
1.277 ad 1920: cv_wait(&p->p_lwpcv, p->p_lock);
1.243 ad 1921: p->p_nlwpwait--;
1922: }
1923: }
1.130 thorpej 1924:
1.243 ad 1925: exitsig = signo;
1926: p->p_acflag |= AXSIG;
1927: p->p_sigctx.ps_signo = signo;
1.277 ad 1928: mutex_exit(p->p_lock);
1.130 thorpej 1929:
1.243 ad 1930: if (docore) {
1.201 christos 1931: if ((error = coredump(l, NULL)) == 0)
1.102 sommerfe 1932: exitsig |= WCOREFLAG;
1933:
1934: if (kern_logsigexit) {
1.224 ad 1935: int uid = l->l_cred ?
1936: (int)kauth_cred_geteuid(l->l_cred) : -1;
1.102 sommerfe 1937:
1.202 perry 1938: if (error)
1.102 sommerfe 1939: log(LOG_INFO, lognocoredump, p->p_pid,
1.243 ad 1940: p->p_comm, uid, signo, error);
1.102 sommerfe 1941: else
1942: log(LOG_INFO, logcoredump, p->p_pid,
1.243 ad 1943: p->p_comm, uid, signo);
1.96 fair 1944: }
1945:
1.240 elad 1946: #ifdef PAX_SEGVGUARD
1.249 thorpej 1947: pax_segvguard(l, p->p_textvp, p->p_comm, true);
1.240 elad 1948: #endif /* PAX_SEGVGUARD */
1.29 cgd 1949: }
1.96 fair 1950:
1.243 ad 1951: /* Acquire the sched state mutex. exit1() will release it. */
1.277 ad 1952: mutex_enter(p->p_lock);
1.243 ad 1953:
1954: /* No longer dumping core. */
1955: p->p_sflag &= ~PS_WCORE;
1956:
1.130 thorpej 1957: exit1(l, W_EXITCODE(0, exitsig));
1.29 cgd 1958: /* NOTREACHED */
1959: }
1960:
1961: /*
1.243 ad 1962: * Put process 'p' into the stopped state and optionally, notify the parent.
1.29 cgd 1963: */
1.243 ad 1964: void
1965: proc_stop(struct proc *p, int notify, int signo)
1.29 cgd 1966: {
1.243 ad 1967: struct lwp *l;
1.112 lukem 1968:
1.277 ad 1969: KASSERT(mutex_owned(p->p_lock));
1.29 cgd 1970:
1.59 cgd 1971: /*
1.243 ad 1972: * First off, set the stopping indicator and bring all sleeping
1973: * LWPs to a halt so they are included in p->p_nrlwps. We musn't
1974: * unlock between here and the p->p_nrlwps check below.
1.59 cgd 1975: */
1.243 ad 1976: p->p_sflag |= PS_STOPPING;
1.272 yamt 1977: if (notify)
1978: p->p_sflag |= PS_NOTIFYSTOP;
1979: else
1980: p->p_sflag &= ~PS_NOTIFYSTOP;
1.260 ad 1981: membar_producer();
1.59 cgd 1982:
1.272 yamt 1983: proc_stop_lwps(p);
1.59 cgd 1984:
1985: /*
1.243 ad 1986: * If there are no LWPs available to take the signal, then we
1987: * signal the parent process immediately. Otherwise, the last
1988: * LWP to stop will take care of it.
1.59 cgd 1989: */
1990:
1.243 ad 1991: if (p->p_nrlwps == 0) {
1.272 yamt 1992: proc_stop_done(p, true, PS_NOCLDSTOP);
1.243 ad 1993: } else {
1994: /*
1995: * Have the remaining LWPs come to a halt, and trigger
1996: * proc_stop_callout() to ensure that they do.
1997: */
1998: LIST_FOREACH(l, &p->p_lwps, l_sibling)
1999: sigpost(l, SIG_DFL, SA_STOP, signo);
2000: callout_schedule(&proc_stop_ch, 1);
1.169 hannken 2001: }
1.29 cgd 2002: }
2003:
2004: /*
1.243 ad 2005: * When stopping a process, we do not immediatly set sleeping LWPs stopped,
2006: * but wait for them to come to a halt at the kernel-user boundary. This is
2007: * to allow LWPs to release any locks that they may hold before stopping.
2008: *
2009: * Non-interruptable sleeps can be long, and there is the potential for an
2010: * LWP to begin sleeping interruptably soon after the process has been set
2011: * stopping (PS_STOPPING). These LWPs will not notice that the process is
2012: * stopping, and so complete halt of the process and the return of status
2013: * information to the parent could be delayed indefinitely.
2014: *
2015: * To handle this race, proc_stop_callout() runs once per tick while there
1.256 ad 2016: * are stopping processes in the system. It sets LWPs that are sleeping
1.243 ad 2017: * interruptably into the LSSTOP state.
2018: *
2019: * Note that we are not concerned about keeping all LWPs stopped while the
2020: * process is stopped: stopped LWPs can awaken briefly to handle signals.
2021: * What we do need to ensure is that all LWPs in a stopping process have
2022: * stopped at least once, so that notification can be sent to the parent
2023: * process.
1.29 cgd 2024: */
1.243 ad 2025: static void
2026: proc_stop_callout(void *cookie)
1.29 cgd 2027: {
1.248 thorpej 2028: bool more, restart;
1.243 ad 2029: struct proc *p;
1.29 cgd 2030:
1.243 ad 2031: (void)cookie;
1.94 bouyer 2032:
1.243 ad 2033: do {
1.249 thorpej 2034: restart = false;
2035: more = false;
1.130 thorpej 2036:
1.276 ad 2037: mutex_enter(proc_lock);
1.243 ad 2038: PROCLIST_FOREACH(p, &allproc) {
1.277 ad 2039: mutex_enter(p->p_lock);
1.130 thorpej 2040:
1.243 ad 2041: if ((p->p_sflag & PS_STOPPING) == 0) {
1.277 ad 2042: mutex_exit(p->p_lock);
1.243 ad 2043: continue;
2044: }
1.130 thorpej 2045:
1.243 ad 2046: /* Stop any LWPs sleeping interruptably. */
1.272 yamt 2047: proc_stop_lwps(p);
1.243 ad 2048: if (p->p_nrlwps == 0) {
2049: /*
2050: * We brought the process to a halt.
2051: * Mark it as stopped and notify the
2052: * parent.
2053: */
2054: if ((p->p_sflag & PS_NOTIFYSTOP) != 0) {
2055: /*
1.272 yamt 2056: * Note that proc_stop_done() will
1.277 ad 2057: * drop p->p_lock briefly.
1.243 ad 2058: * Arrange to restart and check
2059: * all processes again.
2060: */
1.249 thorpej 2061: restart = true;
1.243 ad 2062: }
1.272 yamt 2063: proc_stop_done(p, true, PS_NOCLDSTOP);
1.243 ad 2064: } else
1.249 thorpej 2065: more = true;
1.130 thorpej 2066:
1.277 ad 2067: mutex_exit(p->p_lock);
1.243 ad 2068: if (restart)
2069: break;
2070: }
1.276 ad 2071: mutex_exit(proc_lock);
1.243 ad 2072: } while (restart);
1.185 matt 2073:
1.130 thorpej 2074: /*
1.243 ad 2075: * If we noted processes that are stopping but still have
2076: * running LWPs, then arrange to check again in 1 tick.
1.130 thorpej 2077: */
1.243 ad 2078: if (more)
2079: callout_schedule(&proc_stop_ch, 1);
1.108 jdolecek 2080: }
1.130 thorpej 2081:
1.135 jdolecek 2082: /*
1.243 ad 2083: * Given a process in state SSTOP, set the state back to SACTIVE and
2084: * move LSSTOP'd LWPs to LSSLEEP or make them runnable.
1.135 jdolecek 2085: */
1.243 ad 2086: void
2087: proc_unstop(struct proc *p)
1.135 jdolecek 2088: {
1.243 ad 2089: struct lwp *l;
2090: int sig;
1.208 cube 2091:
1.276 ad 2092: KASSERT(mutex_owned(proc_lock));
1.277 ad 2093: KASSERT(mutex_owned(p->p_lock));
1.135 jdolecek 2094:
1.243 ad 2095: p->p_stat = SACTIVE;
2096: p->p_sflag &= ~PS_STOPPING;
2097: sig = p->p_xstat;
1.219 mrg 2098:
1.243 ad 2099: if (!p->p_waited)
2100: p->p_pptr->p_nstopchild--;
1.173 jdolecek 2101:
1.243 ad 2102: LIST_FOREACH(l, &p->p_lwps, l_sibling) {
2103: lwp_lock(l);
2104: if (l->l_stat != LSSTOP) {
2105: lwp_unlock(l);
2106: continue;
1.171 jdolecek 2107: }
1.243 ad 2108: if (l->l_wchan == NULL) {
2109: setrunnable(l);
2110: continue;
1.241 enami 2111: }
1.246 pavel 2112: if (sig && (l->l_flag & LW_SINTR) != 0) {
1.243 ad 2113: setrunnable(l);
2114: sig = 0;
1.250 ad 2115: } else {
2116: l->l_stat = LSSLEEP;
2117: p->p_nrlwps++;
1.243 ad 2118: lwp_unlock(l);
1.250 ad 2119: }
1.135 jdolecek 2120: }
1.29 cgd 2121: }
1.126 jdolecek 2122:
2123: static int
2124: filt_sigattach(struct knote *kn)
2125: {
2126: struct proc *p = curproc;
2127:
1.274 ad 2128: kn->kn_obj = p;
1.126 jdolecek 2129: kn->kn_flags |= EV_CLEAR; /* automatically set */
2130:
1.277 ad 2131: mutex_enter(p->p_lock);
1.126 jdolecek 2132: SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext);
1.277 ad 2133: mutex_exit(p->p_lock);
1.126 jdolecek 2134:
2135: return (0);
2136: }
2137:
2138: static void
2139: filt_sigdetach(struct knote *kn)
2140: {
1.274 ad 2141: struct proc *p = kn->kn_obj;
1.126 jdolecek 2142:
1.277 ad 2143: mutex_enter(p->p_lock);
1.126 jdolecek 2144: SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext);
1.277 ad 2145: mutex_exit(p->p_lock);
1.126 jdolecek 2146: }
2147:
2148: /*
2149: * signal knotes are shared with proc knotes, so we apply a mask to
2150: * the hint in order to differentiate them from process hints. This
2151: * could be avoided by using a signal-specific knote list, but probably
2152: * isn't worth the trouble.
2153: */
2154: static int
2155: filt_signal(struct knote *kn, long hint)
2156: {
2157:
2158: if (hint & NOTE_SIGNAL) {
2159: hint &= ~NOTE_SIGNAL;
2160:
2161: if (kn->kn_id == hint)
2162: kn->kn_data++;
2163: }
2164: return (kn->kn_data != 0);
2165: }
2166:
2167: const struct filterops sig_filtops = {
2168: 0, filt_sigattach, filt_sigdetach, filt_signal
2169: };
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