Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_sig.c
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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 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD: releng/8.2/sys/kern/kern_sig.c 214756 2010-11-03 21:24:21Z kib $"); 39 40 #include "opt_compat.h" 41 #include "opt_kdtrace.h" 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/signalvar.h> 47 #include <sys/vnode.h> 48 #include <sys/acct.h> 49 #include <sys/condvar.h> 50 #include <sys/event.h> 51 #include <sys/fcntl.h> 52 #include <sys/kernel.h> 53 #include <sys/ktr.h> 54 #include <sys/ktrace.h> 55 #include <sys/lock.h> 56 #include <sys/malloc.h> 57 #include <sys/mutex.h> 58 #include <sys/namei.h> 59 #include <sys/proc.h> 60 #include <sys/posix4.h> 61 #include <sys/pioctl.h> 62 #include <sys/resourcevar.h> 63 #include <sys/sdt.h> 64 #include <sys/sbuf.h> 65 #include <sys/sleepqueue.h> 66 #include <sys/smp.h> 67 #include <sys/stat.h> 68 #include <sys/sx.h> 69 #include <sys/syscallsubr.h> 70 #include <sys/sysctl.h> 71 #include <sys/sysent.h> 72 #include <sys/syslog.h> 73 #include <sys/sysproto.h> 74 #include <sys/timers.h> 75 #include <sys/unistd.h> 76 #include <sys/wait.h> 77 #include <vm/vm.h> 78 #include <vm/vm_extern.h> 79 #include <vm/uma.h> 80 81 #include <machine/cpu.h> 82 83 #include <security/audit/audit.h> 84 85 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 86 87 SDT_PROVIDER_DECLARE(proc); 88 SDT_PROBE_DEFINE(proc, kernel, , signal_send); 89 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 0, "struct thread *"); 90 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 1, "struct proc *"); 91 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 2, "int"); 92 SDT_PROBE_DEFINE(proc, kernel, , signal_clear); 93 SDT_PROBE_ARGTYPE(proc, kernel, , signal_clear, 0, "int"); 94 SDT_PROBE_ARGTYPE(proc, kernel, , signal_clear, 1, "ksiginfo_t *"); 95 SDT_PROBE_DEFINE(proc, kernel, , signal_discard); 96 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 0, "struct thread *"); 97 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 1, "struct proc *"); 98 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 2, "int"); 99 100 static int coredump(struct thread *); 101 static char *expand_name(const char *, uid_t, pid_t); 102 static int killpg1(struct thread *td, int sig, int pgid, int all, 103 ksiginfo_t *ksi); 104 static int issignal(struct thread *td, int stop_allowed); 105 static int sigprop(int sig); 106 static void tdsigwakeup(struct thread *, int, sig_t, int); 107 static void sig_suspend_threads(struct thread *, struct proc *, int); 108 static int filt_sigattach(struct knote *kn); 109 static void filt_sigdetach(struct knote *kn); 110 static int filt_signal(struct knote *kn, long hint); 111 static struct thread *sigtd(struct proc *p, int sig, int prop); 112 static void sigqueue_start(void); 113 114 static uma_zone_t ksiginfo_zone = NULL; 115 struct filterops sig_filtops = 116 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 117 118 int kern_logsigexit = 1; 119 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 120 &kern_logsigexit, 0, 121 "Log processes quitting on abnormal signals to syslog(3)"); 122 123 static int kern_forcesigexit = 1; 124 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 125 &kern_forcesigexit, 0, "Force trap signal to be handled"); 126 127 SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, "POSIX real time signal"); 128 129 static int max_pending_per_proc = 128; 130 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 131 &max_pending_per_proc, 0, "Max pending signals per proc"); 132 133 static int preallocate_siginfo = 1024; 134 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo); 135 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD, 136 &preallocate_siginfo, 0, "Preallocated signal memory size"); 137 138 static int signal_overflow = 0; 139 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 140 &signal_overflow, 0, "Number of signals overflew"); 141 142 static int signal_alloc_fail = 0; 143 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 144 &signal_alloc_fail, 0, "signals failed to be allocated"); 145 146 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 147 148 /* 149 * Policy -- Can ucred cr1 send SIGIO to process cr2? 150 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 151 * in the right situations. 152 */ 153 #define CANSIGIO(cr1, cr2) \ 154 ((cr1)->cr_uid == 0 || \ 155 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 156 (cr1)->cr_uid == (cr2)->cr_ruid || \ 157 (cr1)->cr_ruid == (cr2)->cr_uid || \ 158 (cr1)->cr_uid == (cr2)->cr_uid) 159 160 int sugid_coredump; 161 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 162 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 163 164 static int do_coredump = 1; 165 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 166 &do_coredump, 0, "Enable/Disable coredumps"); 167 168 static int set_core_nodump_flag = 0; 169 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 170 0, "Enable setting the NODUMP flag on coredump files"); 171 172 /* 173 * Signal properties and actions. 174 * The array below categorizes the signals and their default actions 175 * according to the following properties: 176 */ 177 #define SA_KILL 0x01 /* terminates process by default */ 178 #define SA_CORE 0x02 /* ditto and coredumps */ 179 #define SA_STOP 0x04 /* suspend process */ 180 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 181 #define SA_IGNORE 0x10 /* ignore by default */ 182 #define SA_CONT 0x20 /* continue if suspended */ 183 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 184 #define SA_PROC 0x80 /* deliverable to any thread */ 185 186 static int sigproptbl[NSIG] = { 187 SA_KILL|SA_PROC, /* SIGHUP */ 188 SA_KILL|SA_PROC, /* SIGINT */ 189 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */ 190 SA_KILL|SA_CORE, /* SIGILL */ 191 SA_KILL|SA_CORE, /* SIGTRAP */ 192 SA_KILL|SA_CORE, /* SIGABRT */ 193 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */ 194 SA_KILL|SA_CORE, /* SIGFPE */ 195 SA_KILL|SA_PROC, /* SIGKILL */ 196 SA_KILL|SA_CORE, /* SIGBUS */ 197 SA_KILL|SA_CORE, /* SIGSEGV */ 198 SA_KILL|SA_CORE, /* SIGSYS */ 199 SA_KILL|SA_PROC, /* SIGPIPE */ 200 SA_KILL|SA_PROC, /* SIGALRM */ 201 SA_KILL|SA_PROC, /* SIGTERM */ 202 SA_IGNORE|SA_PROC, /* SIGURG */ 203 SA_STOP|SA_PROC, /* SIGSTOP */ 204 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */ 205 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */ 206 SA_IGNORE|SA_PROC, /* SIGCHLD */ 207 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */ 208 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */ 209 SA_IGNORE|SA_PROC, /* SIGIO */ 210 SA_KILL, /* SIGXCPU */ 211 SA_KILL, /* SIGXFSZ */ 212 SA_KILL|SA_PROC, /* SIGVTALRM */ 213 SA_KILL|SA_PROC, /* SIGPROF */ 214 SA_IGNORE|SA_PROC, /* SIGWINCH */ 215 SA_IGNORE|SA_PROC, /* SIGINFO */ 216 SA_KILL|SA_PROC, /* SIGUSR1 */ 217 SA_KILL|SA_PROC, /* SIGUSR2 */ 218 }; 219 220 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 221 222 static void 223 sigqueue_start(void) 224 { 225 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 226 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 227 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 228 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 229 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 230 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 231 } 232 233 ksiginfo_t * 234 ksiginfo_alloc(int wait) 235 { 236 int flags; 237 238 flags = M_ZERO; 239 if (! wait) 240 flags |= M_NOWAIT; 241 if (ksiginfo_zone != NULL) 242 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 243 return (NULL); 244 } 245 246 void 247 ksiginfo_free(ksiginfo_t *ksi) 248 { 249 uma_zfree(ksiginfo_zone, ksi); 250 } 251 252 static __inline int 253 ksiginfo_tryfree(ksiginfo_t *ksi) 254 { 255 if (!(ksi->ksi_flags & KSI_EXT)) { 256 uma_zfree(ksiginfo_zone, ksi); 257 return (1); 258 } 259 return (0); 260 } 261 262 void 263 sigqueue_init(sigqueue_t *list, struct proc *p) 264 { 265 SIGEMPTYSET(list->sq_signals); 266 SIGEMPTYSET(list->sq_kill); 267 TAILQ_INIT(&list->sq_list); 268 list->sq_proc = p; 269 list->sq_flags = SQ_INIT; 270 } 271 272 /* 273 * Get a signal's ksiginfo. 274 * Return: 275 * 0 - signal not found 276 * others - signal number 277 */ 278 static int 279 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 280 { 281 struct proc *p = sq->sq_proc; 282 struct ksiginfo *ksi, *next; 283 int count = 0; 284 285 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 286 287 if (!SIGISMEMBER(sq->sq_signals, signo)) 288 return (0); 289 290 if (SIGISMEMBER(sq->sq_kill, signo)) { 291 count++; 292 SIGDELSET(sq->sq_kill, signo); 293 } 294 295 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 296 if (ksi->ksi_signo == signo) { 297 if (count == 0) { 298 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 299 ksi->ksi_sigq = NULL; 300 ksiginfo_copy(ksi, si); 301 if (ksiginfo_tryfree(ksi) && p != NULL) 302 p->p_pendingcnt--; 303 } 304 if (++count > 1) 305 break; 306 } 307 } 308 309 if (count <= 1) 310 SIGDELSET(sq->sq_signals, signo); 311 si->ksi_signo = signo; 312 return (signo); 313 } 314 315 void 316 sigqueue_take(ksiginfo_t *ksi) 317 { 318 struct ksiginfo *kp; 319 struct proc *p; 320 sigqueue_t *sq; 321 322 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 323 return; 324 325 p = sq->sq_proc; 326 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 327 ksi->ksi_sigq = NULL; 328 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 329 p->p_pendingcnt--; 330 331 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 332 kp = TAILQ_NEXT(kp, ksi_link)) { 333 if (kp->ksi_signo == ksi->ksi_signo) 334 break; 335 } 336 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo)) 337 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 338 } 339 340 static int 341 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 342 { 343 struct proc *p = sq->sq_proc; 344 struct ksiginfo *ksi; 345 int ret = 0; 346 347 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 348 349 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 350 SIGADDSET(sq->sq_kill, signo); 351 goto out_set_bit; 352 } 353 354 /* directly insert the ksi, don't copy it */ 355 if (si->ksi_flags & KSI_INS) { 356 if (si->ksi_flags & KSI_HEAD) 357 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 358 else 359 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 360 si->ksi_sigq = sq; 361 goto out_set_bit; 362 } 363 364 if (__predict_false(ksiginfo_zone == NULL)) { 365 SIGADDSET(sq->sq_kill, signo); 366 goto out_set_bit; 367 } 368 369 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 370 signal_overflow++; 371 ret = EAGAIN; 372 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 373 signal_alloc_fail++; 374 ret = EAGAIN; 375 } else { 376 if (p != NULL) 377 p->p_pendingcnt++; 378 ksiginfo_copy(si, ksi); 379 ksi->ksi_signo = signo; 380 if (si->ksi_flags & KSI_HEAD) 381 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 382 else 383 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 384 ksi->ksi_sigq = sq; 385 } 386 387 if ((si->ksi_flags & KSI_TRAP) != 0 || 388 (si->ksi_flags & KSI_SIGQ) == 0) { 389 if (ret != 0) 390 SIGADDSET(sq->sq_kill, signo); 391 ret = 0; 392 goto out_set_bit; 393 } 394 395 if (ret != 0) 396 return (ret); 397 398 out_set_bit: 399 SIGADDSET(sq->sq_signals, signo); 400 return (ret); 401 } 402 403 void 404 sigqueue_flush(sigqueue_t *sq) 405 { 406 struct proc *p = sq->sq_proc; 407 ksiginfo_t *ksi; 408 409 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 410 411 if (p != NULL) 412 PROC_LOCK_ASSERT(p, MA_OWNED); 413 414 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 415 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 416 ksi->ksi_sigq = NULL; 417 if (ksiginfo_tryfree(ksi) && p != NULL) 418 p->p_pendingcnt--; 419 } 420 421 SIGEMPTYSET(sq->sq_signals); 422 SIGEMPTYSET(sq->sq_kill); 423 } 424 425 static void 426 sigqueue_collect_set(sigqueue_t *sq, sigset_t *set) 427 { 428 ksiginfo_t *ksi; 429 430 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 431 432 TAILQ_FOREACH(ksi, &sq->sq_list, ksi_link) 433 SIGADDSET(*set, ksi->ksi_signo); 434 SIGSETOR(*set, sq->sq_kill); 435 } 436 437 static void 438 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, sigset_t *setp) 439 { 440 sigset_t tmp, set; 441 struct proc *p1, *p2; 442 ksiginfo_t *ksi, *next; 443 444 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 445 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 446 /* 447 * make a copy, this allows setp to point to src or dst 448 * sq_signals without trouble. 449 */ 450 set = *setp; 451 p1 = src->sq_proc; 452 p2 = dst->sq_proc; 453 /* Move siginfo to target list */ 454 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 455 if (SIGISMEMBER(set, ksi->ksi_signo)) { 456 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 457 if (p1 != NULL) 458 p1->p_pendingcnt--; 459 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 460 ksi->ksi_sigq = dst; 461 if (p2 != NULL) 462 p2->p_pendingcnt++; 463 } 464 } 465 466 /* Move pending bits to target list */ 467 tmp = src->sq_kill; 468 SIGSETAND(tmp, set); 469 SIGSETOR(dst->sq_kill, tmp); 470 SIGSETNAND(src->sq_kill, tmp); 471 472 tmp = src->sq_signals; 473 SIGSETAND(tmp, set); 474 SIGSETOR(dst->sq_signals, tmp); 475 SIGSETNAND(src->sq_signals, tmp); 476 477 /* Finally, rescan src queue and set pending bits for it */ 478 sigqueue_collect_set(src, &src->sq_signals); 479 } 480 481 static void 482 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 483 { 484 sigset_t set; 485 486 SIGEMPTYSET(set); 487 SIGADDSET(set, signo); 488 sigqueue_move_set(src, dst, &set); 489 } 490 491 static void 492 sigqueue_delete_set(sigqueue_t *sq, sigset_t *set) 493 { 494 struct proc *p = sq->sq_proc; 495 ksiginfo_t *ksi, *next; 496 497 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 498 499 /* Remove siginfo queue */ 500 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 501 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 502 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 503 ksi->ksi_sigq = NULL; 504 if (ksiginfo_tryfree(ksi) && p != NULL) 505 p->p_pendingcnt--; 506 } 507 } 508 SIGSETNAND(sq->sq_kill, *set); 509 SIGSETNAND(sq->sq_signals, *set); 510 /* Finally, rescan queue and set pending bits for it */ 511 sigqueue_collect_set(sq, &sq->sq_signals); 512 } 513 514 void 515 sigqueue_delete(sigqueue_t *sq, int signo) 516 { 517 sigset_t set; 518 519 SIGEMPTYSET(set); 520 SIGADDSET(set, signo); 521 sigqueue_delete_set(sq, &set); 522 } 523 524 /* Remove a set of signals for a process */ 525 static void 526 sigqueue_delete_set_proc(struct proc *p, sigset_t *set) 527 { 528 sigqueue_t worklist; 529 struct thread *td0; 530 531 PROC_LOCK_ASSERT(p, MA_OWNED); 532 533 sigqueue_init(&worklist, NULL); 534 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 535 536 FOREACH_THREAD_IN_PROC(p, td0) 537 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 538 539 sigqueue_flush(&worklist); 540 } 541 542 void 543 sigqueue_delete_proc(struct proc *p, int signo) 544 { 545 sigset_t set; 546 547 SIGEMPTYSET(set); 548 SIGADDSET(set, signo); 549 sigqueue_delete_set_proc(p, &set); 550 } 551 552 static void 553 sigqueue_delete_stopmask_proc(struct proc *p) 554 { 555 sigset_t set; 556 557 SIGEMPTYSET(set); 558 SIGADDSET(set, SIGSTOP); 559 SIGADDSET(set, SIGTSTP); 560 SIGADDSET(set, SIGTTIN); 561 SIGADDSET(set, SIGTTOU); 562 sigqueue_delete_set_proc(p, &set); 563 } 564 565 /* 566 * Determine signal that should be delivered to process p, the current 567 * process, 0 if none. If there is a pending stop signal with default 568 * action, the process stops in issignal(). 569 */ 570 int 571 cursig(struct thread *td, int stop_allowed) 572 { 573 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 574 KASSERT(stop_allowed == SIG_STOP_ALLOWED || 575 stop_allowed == SIG_STOP_NOT_ALLOWED, ("cursig: stop_allowed")); 576 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 577 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 578 return (SIGPENDING(td) ? issignal(td, stop_allowed) : 0); 579 } 580 581 /* 582 * Arrange for ast() to handle unmasked pending signals on return to user 583 * mode. This must be called whenever a signal is added to td_sigqueue or 584 * unmasked in td_sigmask. 585 */ 586 void 587 signotify(struct thread *td) 588 { 589 struct proc *p; 590 591 p = td->td_proc; 592 593 PROC_LOCK_ASSERT(p, MA_OWNED); 594 595 if (SIGPENDING(td)) { 596 thread_lock(td); 597 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 598 thread_unlock(td); 599 } 600 } 601 602 int 603 sigonstack(size_t sp) 604 { 605 struct thread *td = curthread; 606 607 return ((td->td_pflags & TDP_ALTSTACK) ? 608 #if defined(COMPAT_43) 609 ((td->td_sigstk.ss_size == 0) ? 610 (td->td_sigstk.ss_flags & SS_ONSTACK) : 611 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 612 #else 613 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 614 #endif 615 : 0); 616 } 617 618 static __inline int 619 sigprop(int sig) 620 { 621 622 if (sig > 0 && sig < NSIG) 623 return (sigproptbl[_SIG_IDX(sig)]); 624 return (0); 625 } 626 627 int 628 sig_ffs(sigset_t *set) 629 { 630 int i; 631 632 for (i = 0; i < _SIG_WORDS; i++) 633 if (set->__bits[i]) 634 return (ffs(set->__bits[i]) + (i * 32)); 635 return (0); 636 } 637 638 /* 639 * kern_sigaction 640 * sigaction 641 * freebsd4_sigaction 642 * osigaction 643 */ 644 int 645 kern_sigaction(td, sig, act, oact, flags) 646 struct thread *td; 647 register int sig; 648 struct sigaction *act, *oact; 649 int flags; 650 { 651 struct sigacts *ps; 652 struct proc *p = td->td_proc; 653 654 if (!_SIG_VALID(sig)) 655 return (EINVAL); 656 657 PROC_LOCK(p); 658 ps = p->p_sigacts; 659 mtx_lock(&ps->ps_mtx); 660 if (oact) { 661 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 662 oact->sa_flags = 0; 663 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 664 oact->sa_flags |= SA_ONSTACK; 665 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 666 oact->sa_flags |= SA_RESTART; 667 if (SIGISMEMBER(ps->ps_sigreset, sig)) 668 oact->sa_flags |= SA_RESETHAND; 669 if (SIGISMEMBER(ps->ps_signodefer, sig)) 670 oact->sa_flags |= SA_NODEFER; 671 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 672 oact->sa_flags |= SA_SIGINFO; 673 oact->sa_sigaction = 674 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 675 } else 676 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 677 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 678 oact->sa_flags |= SA_NOCLDSTOP; 679 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 680 oact->sa_flags |= SA_NOCLDWAIT; 681 } 682 if (act) { 683 if ((sig == SIGKILL || sig == SIGSTOP) && 684 act->sa_handler != SIG_DFL) { 685 mtx_unlock(&ps->ps_mtx); 686 PROC_UNLOCK(p); 687 return (EINVAL); 688 } 689 690 /* 691 * Change setting atomically. 692 */ 693 694 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 695 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 696 if (act->sa_flags & SA_SIGINFO) { 697 ps->ps_sigact[_SIG_IDX(sig)] = 698 (__sighandler_t *)act->sa_sigaction; 699 SIGADDSET(ps->ps_siginfo, sig); 700 } else { 701 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 702 SIGDELSET(ps->ps_siginfo, sig); 703 } 704 if (!(act->sa_flags & SA_RESTART)) 705 SIGADDSET(ps->ps_sigintr, sig); 706 else 707 SIGDELSET(ps->ps_sigintr, sig); 708 if (act->sa_flags & SA_ONSTACK) 709 SIGADDSET(ps->ps_sigonstack, sig); 710 else 711 SIGDELSET(ps->ps_sigonstack, sig); 712 if (act->sa_flags & SA_RESETHAND) 713 SIGADDSET(ps->ps_sigreset, sig); 714 else 715 SIGDELSET(ps->ps_sigreset, sig); 716 if (act->sa_flags & SA_NODEFER) 717 SIGADDSET(ps->ps_signodefer, sig); 718 else 719 SIGDELSET(ps->ps_signodefer, sig); 720 if (sig == SIGCHLD) { 721 if (act->sa_flags & SA_NOCLDSTOP) 722 ps->ps_flag |= PS_NOCLDSTOP; 723 else 724 ps->ps_flag &= ~PS_NOCLDSTOP; 725 if (act->sa_flags & SA_NOCLDWAIT) { 726 /* 727 * Paranoia: since SA_NOCLDWAIT is implemented 728 * by reparenting the dying child to PID 1 (and 729 * trust it to reap the zombie), PID 1 itself 730 * is forbidden to set SA_NOCLDWAIT. 731 */ 732 if (p->p_pid == 1) 733 ps->ps_flag &= ~PS_NOCLDWAIT; 734 else 735 ps->ps_flag |= PS_NOCLDWAIT; 736 } else 737 ps->ps_flag &= ~PS_NOCLDWAIT; 738 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 739 ps->ps_flag |= PS_CLDSIGIGN; 740 else 741 ps->ps_flag &= ~PS_CLDSIGIGN; 742 } 743 /* 744 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 745 * and for signals set to SIG_DFL where the default is to 746 * ignore. However, don't put SIGCONT in ps_sigignore, as we 747 * have to restart the process. 748 */ 749 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 750 (sigprop(sig) & SA_IGNORE && 751 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 752 /* never to be seen again */ 753 sigqueue_delete_proc(p, sig); 754 if (sig != SIGCONT) 755 /* easier in psignal */ 756 SIGADDSET(ps->ps_sigignore, sig); 757 SIGDELSET(ps->ps_sigcatch, sig); 758 } else { 759 SIGDELSET(ps->ps_sigignore, sig); 760 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 761 SIGDELSET(ps->ps_sigcatch, sig); 762 else 763 SIGADDSET(ps->ps_sigcatch, sig); 764 } 765 #ifdef COMPAT_FREEBSD4 766 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 767 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 768 (flags & KSA_FREEBSD4) == 0) 769 SIGDELSET(ps->ps_freebsd4, sig); 770 else 771 SIGADDSET(ps->ps_freebsd4, sig); 772 #endif 773 #ifdef COMPAT_43 774 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 775 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 776 (flags & KSA_OSIGSET) == 0) 777 SIGDELSET(ps->ps_osigset, sig); 778 else 779 SIGADDSET(ps->ps_osigset, sig); 780 #endif 781 } 782 mtx_unlock(&ps->ps_mtx); 783 PROC_UNLOCK(p); 784 return (0); 785 } 786 787 #ifndef _SYS_SYSPROTO_H_ 788 struct sigaction_args { 789 int sig; 790 struct sigaction *act; 791 struct sigaction *oact; 792 }; 793 #endif 794 int 795 sigaction(td, uap) 796 struct thread *td; 797 register struct sigaction_args *uap; 798 { 799 struct sigaction act, oact; 800 register struct sigaction *actp, *oactp; 801 int error; 802 803 actp = (uap->act != NULL) ? &act : NULL; 804 oactp = (uap->oact != NULL) ? &oact : NULL; 805 if (actp) { 806 error = copyin(uap->act, actp, sizeof(act)); 807 if (error) 808 return (error); 809 } 810 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 811 if (oactp && !error) 812 error = copyout(oactp, uap->oact, sizeof(oact)); 813 return (error); 814 } 815 816 #ifdef COMPAT_FREEBSD4 817 #ifndef _SYS_SYSPROTO_H_ 818 struct freebsd4_sigaction_args { 819 int sig; 820 struct sigaction *act; 821 struct sigaction *oact; 822 }; 823 #endif 824 int 825 freebsd4_sigaction(td, uap) 826 struct thread *td; 827 register struct freebsd4_sigaction_args *uap; 828 { 829 struct sigaction act, oact; 830 register struct sigaction *actp, *oactp; 831 int error; 832 833 834 actp = (uap->act != NULL) ? &act : NULL; 835 oactp = (uap->oact != NULL) ? &oact : NULL; 836 if (actp) { 837 error = copyin(uap->act, actp, sizeof(act)); 838 if (error) 839 return (error); 840 } 841 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 842 if (oactp && !error) 843 error = copyout(oactp, uap->oact, sizeof(oact)); 844 return (error); 845 } 846 #endif /* COMAPT_FREEBSD4 */ 847 848 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 849 #ifndef _SYS_SYSPROTO_H_ 850 struct osigaction_args { 851 int signum; 852 struct osigaction *nsa; 853 struct osigaction *osa; 854 }; 855 #endif 856 int 857 osigaction(td, uap) 858 struct thread *td; 859 register struct osigaction_args *uap; 860 { 861 struct osigaction sa; 862 struct sigaction nsa, osa; 863 register struct sigaction *nsap, *osap; 864 int error; 865 866 if (uap->signum <= 0 || uap->signum >= ONSIG) 867 return (EINVAL); 868 869 nsap = (uap->nsa != NULL) ? &nsa : NULL; 870 osap = (uap->osa != NULL) ? &osa : NULL; 871 872 if (nsap) { 873 error = copyin(uap->nsa, &sa, sizeof(sa)); 874 if (error) 875 return (error); 876 nsap->sa_handler = sa.sa_handler; 877 nsap->sa_flags = sa.sa_flags; 878 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 879 } 880 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 881 if (osap && !error) { 882 sa.sa_handler = osap->sa_handler; 883 sa.sa_flags = osap->sa_flags; 884 SIG2OSIG(osap->sa_mask, sa.sa_mask); 885 error = copyout(&sa, uap->osa, sizeof(sa)); 886 } 887 return (error); 888 } 889 890 #if !defined(__i386__) 891 /* Avoid replicating the same stub everywhere */ 892 int 893 osigreturn(td, uap) 894 struct thread *td; 895 struct osigreturn_args *uap; 896 { 897 898 return (nosys(td, (struct nosys_args *)uap)); 899 } 900 #endif 901 #endif /* COMPAT_43 */ 902 903 /* 904 * Initialize signal state for process 0; 905 * set to ignore signals that are ignored by default. 906 */ 907 void 908 siginit(p) 909 struct proc *p; 910 { 911 register int i; 912 struct sigacts *ps; 913 914 PROC_LOCK(p); 915 ps = p->p_sigacts; 916 mtx_lock(&ps->ps_mtx); 917 for (i = 1; i <= NSIG; i++) 918 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 919 SIGADDSET(ps->ps_sigignore, i); 920 mtx_unlock(&ps->ps_mtx); 921 PROC_UNLOCK(p); 922 } 923 924 /* 925 * Reset signals for an exec of the specified process. 926 */ 927 void 928 execsigs(struct proc *p) 929 { 930 struct sigacts *ps; 931 int sig; 932 struct thread *td; 933 934 /* 935 * Reset caught signals. Held signals remain held 936 * through td_sigmask (unless they were caught, 937 * and are now ignored by default). 938 */ 939 PROC_LOCK_ASSERT(p, MA_OWNED); 940 td = FIRST_THREAD_IN_PROC(p); 941 ps = p->p_sigacts; 942 mtx_lock(&ps->ps_mtx); 943 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 944 sig = sig_ffs(&ps->ps_sigcatch); 945 SIGDELSET(ps->ps_sigcatch, sig); 946 if (sigprop(sig) & SA_IGNORE) { 947 if (sig != SIGCONT) 948 SIGADDSET(ps->ps_sigignore, sig); 949 sigqueue_delete_proc(p, sig); 950 } 951 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 952 } 953 /* 954 * Reset stack state to the user stack. 955 * Clear set of signals caught on the signal stack. 956 */ 957 td->td_sigstk.ss_flags = SS_DISABLE; 958 td->td_sigstk.ss_size = 0; 959 td->td_sigstk.ss_sp = 0; 960 td->td_pflags &= ~TDP_ALTSTACK; 961 /* 962 * Reset no zombies if child dies flag as Solaris does. 963 */ 964 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 965 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 966 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 967 mtx_unlock(&ps->ps_mtx); 968 } 969 970 /* 971 * kern_sigprocmask() 972 * 973 * Manipulate signal mask. 974 */ 975 int 976 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 977 int flags) 978 { 979 sigset_t new_block, oset1; 980 struct proc *p; 981 int error; 982 983 p = td->td_proc; 984 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 985 PROC_LOCK(p); 986 if (oset != NULL) 987 *oset = td->td_sigmask; 988 989 error = 0; 990 SIGEMPTYSET(new_block); 991 if (set != NULL) { 992 switch (how) { 993 case SIG_BLOCK: 994 SIG_CANTMASK(*set); 995 oset1 = td->td_sigmask; 996 SIGSETOR(td->td_sigmask, *set); 997 new_block = td->td_sigmask; 998 SIGSETNAND(new_block, oset1); 999 break; 1000 case SIG_UNBLOCK: 1001 SIGSETNAND(td->td_sigmask, *set); 1002 signotify(td); 1003 break; 1004 case SIG_SETMASK: 1005 SIG_CANTMASK(*set); 1006 oset1 = td->td_sigmask; 1007 if (flags & SIGPROCMASK_OLD) 1008 SIGSETLO(td->td_sigmask, *set); 1009 else 1010 td->td_sigmask = *set; 1011 new_block = td->td_sigmask; 1012 SIGSETNAND(new_block, oset1); 1013 signotify(td); 1014 break; 1015 default: 1016 error = EINVAL; 1017 break; 1018 } 1019 } 1020 1021 /* 1022 * The new_block set contains signals that were not previously 1023 * blocked, but are blocked now. 1024 * 1025 * In case we block any signal that was not previously blocked 1026 * for td, and process has the signal pending, try to schedule 1027 * signal delivery to some thread that does not block the signal, 1028 * possibly waking it up. 1029 */ 1030 if (p->p_numthreads != 1) 1031 reschedule_signals(p, new_block, flags); 1032 1033 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1034 PROC_UNLOCK(p); 1035 return (error); 1036 } 1037 1038 #ifndef _SYS_SYSPROTO_H_ 1039 struct sigprocmask_args { 1040 int how; 1041 const sigset_t *set; 1042 sigset_t *oset; 1043 }; 1044 #endif 1045 int 1046 sigprocmask(td, uap) 1047 register struct thread *td; 1048 struct sigprocmask_args *uap; 1049 { 1050 sigset_t set, oset; 1051 sigset_t *setp, *osetp; 1052 int error; 1053 1054 setp = (uap->set != NULL) ? &set : NULL; 1055 osetp = (uap->oset != NULL) ? &oset : NULL; 1056 if (setp) { 1057 error = copyin(uap->set, setp, sizeof(set)); 1058 if (error) 1059 return (error); 1060 } 1061 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1062 if (osetp && !error) { 1063 error = copyout(osetp, uap->oset, sizeof(oset)); 1064 } 1065 return (error); 1066 } 1067 1068 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1069 #ifndef _SYS_SYSPROTO_H_ 1070 struct osigprocmask_args { 1071 int how; 1072 osigset_t mask; 1073 }; 1074 #endif 1075 int 1076 osigprocmask(td, uap) 1077 register struct thread *td; 1078 struct osigprocmask_args *uap; 1079 { 1080 sigset_t set, oset; 1081 int error; 1082 1083 OSIG2SIG(uap->mask, set); 1084 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1085 SIG2OSIG(oset, td->td_retval[0]); 1086 return (error); 1087 } 1088 #endif /* COMPAT_43 */ 1089 1090 int 1091 sigwait(struct thread *td, struct sigwait_args *uap) 1092 { 1093 ksiginfo_t ksi; 1094 sigset_t set; 1095 int error; 1096 1097 error = copyin(uap->set, &set, sizeof(set)); 1098 if (error) { 1099 td->td_retval[0] = error; 1100 return (0); 1101 } 1102 1103 error = kern_sigtimedwait(td, set, &ksi, NULL); 1104 if (error) { 1105 if (error == ERESTART) 1106 return (error); 1107 td->td_retval[0] = error; 1108 return (0); 1109 } 1110 1111 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1112 td->td_retval[0] = error; 1113 return (0); 1114 } 1115 1116 int 1117 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1118 { 1119 struct timespec ts; 1120 struct timespec *timeout; 1121 sigset_t set; 1122 ksiginfo_t ksi; 1123 int error; 1124 1125 if (uap->timeout) { 1126 error = copyin(uap->timeout, &ts, sizeof(ts)); 1127 if (error) 1128 return (error); 1129 1130 timeout = &ts; 1131 } else 1132 timeout = NULL; 1133 1134 error = copyin(uap->set, &set, sizeof(set)); 1135 if (error) 1136 return (error); 1137 1138 error = kern_sigtimedwait(td, set, &ksi, timeout); 1139 if (error) 1140 return (error); 1141 1142 if (uap->info) 1143 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1144 1145 if (error == 0) 1146 td->td_retval[0] = ksi.ksi_signo; 1147 return (error); 1148 } 1149 1150 int 1151 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1152 { 1153 ksiginfo_t ksi; 1154 sigset_t set; 1155 int error; 1156 1157 error = copyin(uap->set, &set, sizeof(set)); 1158 if (error) 1159 return (error); 1160 1161 error = kern_sigtimedwait(td, set, &ksi, NULL); 1162 if (error) 1163 return (error); 1164 1165 if (uap->info) 1166 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1167 1168 if (error == 0) 1169 td->td_retval[0] = ksi.ksi_signo; 1170 return (error); 1171 } 1172 1173 int 1174 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1175 struct timespec *timeout) 1176 { 1177 struct sigacts *ps; 1178 sigset_t savedmask; 1179 struct proc *p; 1180 int error, sig, hz, i, timevalid = 0; 1181 struct timespec rts, ets, ts; 1182 struct timeval tv; 1183 1184 p = td->td_proc; 1185 error = 0; 1186 sig = 0; 1187 ets.tv_sec = 0; 1188 ets.tv_nsec = 0; 1189 SIG_CANTMASK(waitset); 1190 1191 PROC_LOCK(p); 1192 ps = p->p_sigacts; 1193 savedmask = td->td_sigmask; 1194 if (timeout) { 1195 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1196 timevalid = 1; 1197 getnanouptime(&rts); 1198 ets = rts; 1199 timespecadd(&ets, timeout); 1200 } 1201 } 1202 1203 restart: 1204 for (i = 1; i <= _SIG_MAXSIG; ++i) { 1205 if (!SIGISMEMBER(waitset, i)) 1206 continue; 1207 if (!SIGISMEMBER(td->td_sigqueue.sq_signals, i)) { 1208 if (SIGISMEMBER(p->p_sigqueue.sq_signals, i)) { 1209 sigqueue_move(&p->p_sigqueue, 1210 &td->td_sigqueue, i); 1211 } else 1212 continue; 1213 } 1214 1215 SIGFILLSET(td->td_sigmask); 1216 SIG_CANTMASK(td->td_sigmask); 1217 SIGDELSET(td->td_sigmask, i); 1218 mtx_lock(&ps->ps_mtx); 1219 sig = cursig(td, SIG_STOP_ALLOWED); 1220 mtx_unlock(&ps->ps_mtx); 1221 if (sig) 1222 goto out; 1223 else { 1224 /* 1225 * Because cursig() may have stopped current thread, 1226 * after it is resumed, things may have already been 1227 * changed, it should rescan any pending signals. 1228 */ 1229 goto restart; 1230 } 1231 } 1232 1233 if (error) 1234 goto out; 1235 1236 /* 1237 * POSIX says this must be checked after looking for pending 1238 * signals. 1239 */ 1240 if (timeout) { 1241 if (!timevalid) { 1242 error = EINVAL; 1243 goto out; 1244 } 1245 getnanouptime(&rts); 1246 if (timespeccmp(&rts, &ets, >=)) { 1247 error = EAGAIN; 1248 goto out; 1249 } 1250 ts = ets; 1251 timespecsub(&ts, &rts); 1252 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1253 hz = tvtohz(&tv); 1254 } else 1255 hz = 0; 1256 1257 td->td_sigmask = savedmask; 1258 SIGSETNAND(td->td_sigmask, waitset); 1259 signotify(td); 1260 error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz); 1261 if (timeout) { 1262 if (error == ERESTART) { 1263 /* timeout can not be restarted. */ 1264 error = EINTR; 1265 } else if (error == EAGAIN) { 1266 /* will calculate timeout by ourself. */ 1267 error = 0; 1268 } 1269 } 1270 goto restart; 1271 1272 out: 1273 td->td_sigmask = savedmask; 1274 signotify(td); 1275 if (sig) { 1276 ksiginfo_init(ksi); 1277 sigqueue_get(&td->td_sigqueue, sig, ksi); 1278 ksi->ksi_signo = sig; 1279 1280 SDT_PROBE(proc, kernel, , signal_clear, sig, ksi, 0, 0, 0); 1281 1282 if (ksi->ksi_code == SI_TIMER) 1283 itimer_accept(p, ksi->ksi_timerid, ksi); 1284 error = 0; 1285 1286 #ifdef KTRACE 1287 if (KTRPOINT(td, KTR_PSIG)) { 1288 sig_t action; 1289 1290 mtx_lock(&ps->ps_mtx); 1291 action = ps->ps_sigact[_SIG_IDX(sig)]; 1292 mtx_unlock(&ps->ps_mtx); 1293 ktrpsig(sig, action, &td->td_sigmask, 0); 1294 } 1295 #endif 1296 if (sig == SIGKILL) 1297 sigexit(td, sig); 1298 } 1299 PROC_UNLOCK(p); 1300 return (error); 1301 } 1302 1303 #ifndef _SYS_SYSPROTO_H_ 1304 struct sigpending_args { 1305 sigset_t *set; 1306 }; 1307 #endif 1308 int 1309 sigpending(td, uap) 1310 struct thread *td; 1311 struct sigpending_args *uap; 1312 { 1313 struct proc *p = td->td_proc; 1314 sigset_t pending; 1315 1316 PROC_LOCK(p); 1317 pending = p->p_sigqueue.sq_signals; 1318 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1319 PROC_UNLOCK(p); 1320 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1321 } 1322 1323 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1324 #ifndef _SYS_SYSPROTO_H_ 1325 struct osigpending_args { 1326 int dummy; 1327 }; 1328 #endif 1329 int 1330 osigpending(td, uap) 1331 struct thread *td; 1332 struct osigpending_args *uap; 1333 { 1334 struct proc *p = td->td_proc; 1335 sigset_t pending; 1336 1337 PROC_LOCK(p); 1338 pending = p->p_sigqueue.sq_signals; 1339 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1340 PROC_UNLOCK(p); 1341 SIG2OSIG(pending, td->td_retval[0]); 1342 return (0); 1343 } 1344 #endif /* COMPAT_43 */ 1345 1346 #if defined(COMPAT_43) 1347 /* 1348 * Generalized interface signal handler, 4.3-compatible. 1349 */ 1350 #ifndef _SYS_SYSPROTO_H_ 1351 struct osigvec_args { 1352 int signum; 1353 struct sigvec *nsv; 1354 struct sigvec *osv; 1355 }; 1356 #endif 1357 /* ARGSUSED */ 1358 int 1359 osigvec(td, uap) 1360 struct thread *td; 1361 register struct osigvec_args *uap; 1362 { 1363 struct sigvec vec; 1364 struct sigaction nsa, osa; 1365 register struct sigaction *nsap, *osap; 1366 int error; 1367 1368 if (uap->signum <= 0 || uap->signum >= ONSIG) 1369 return (EINVAL); 1370 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1371 osap = (uap->osv != NULL) ? &osa : NULL; 1372 if (nsap) { 1373 error = copyin(uap->nsv, &vec, sizeof(vec)); 1374 if (error) 1375 return (error); 1376 nsap->sa_handler = vec.sv_handler; 1377 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1378 nsap->sa_flags = vec.sv_flags; 1379 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1380 } 1381 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1382 if (osap && !error) { 1383 vec.sv_handler = osap->sa_handler; 1384 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1385 vec.sv_flags = osap->sa_flags; 1386 vec.sv_flags &= ~SA_NOCLDWAIT; 1387 vec.sv_flags ^= SA_RESTART; 1388 error = copyout(&vec, uap->osv, sizeof(vec)); 1389 } 1390 return (error); 1391 } 1392 1393 #ifndef _SYS_SYSPROTO_H_ 1394 struct osigblock_args { 1395 int mask; 1396 }; 1397 #endif 1398 int 1399 osigblock(td, uap) 1400 register struct thread *td; 1401 struct osigblock_args *uap; 1402 { 1403 sigset_t set, oset; 1404 1405 OSIG2SIG(uap->mask, set); 1406 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1407 SIG2OSIG(oset, td->td_retval[0]); 1408 return (0); 1409 } 1410 1411 #ifndef _SYS_SYSPROTO_H_ 1412 struct osigsetmask_args { 1413 int mask; 1414 }; 1415 #endif 1416 int 1417 osigsetmask(td, uap) 1418 struct thread *td; 1419 struct osigsetmask_args *uap; 1420 { 1421 sigset_t set, oset; 1422 1423 OSIG2SIG(uap->mask, set); 1424 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1425 SIG2OSIG(oset, td->td_retval[0]); 1426 return (0); 1427 } 1428 #endif /* COMPAT_43 */ 1429 1430 /* 1431 * Suspend calling thread until signal, providing mask to be set in the 1432 * meantime. 1433 */ 1434 #ifndef _SYS_SYSPROTO_H_ 1435 struct sigsuspend_args { 1436 const sigset_t *sigmask; 1437 }; 1438 #endif 1439 /* ARGSUSED */ 1440 int 1441 sigsuspend(td, uap) 1442 struct thread *td; 1443 struct sigsuspend_args *uap; 1444 { 1445 sigset_t mask; 1446 int error; 1447 1448 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1449 if (error) 1450 return (error); 1451 return (kern_sigsuspend(td, mask)); 1452 } 1453 1454 int 1455 kern_sigsuspend(struct thread *td, sigset_t mask) 1456 { 1457 struct proc *p = td->td_proc; 1458 int has_sig, sig; 1459 1460 /* 1461 * When returning from sigsuspend, we want 1462 * the old mask to be restored after the 1463 * signal handler has finished. Thus, we 1464 * save it here and mark the sigacts structure 1465 * to indicate this. 1466 */ 1467 PROC_LOCK(p); 1468 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1469 SIGPROCMASK_PROC_LOCKED); 1470 td->td_pflags |= TDP_OLDMASK; 1471 1472 /* 1473 * Process signals now. Otherwise, we can get spurious wakeup 1474 * due to signal entered process queue, but delivered to other 1475 * thread. But sigsuspend should return only on signal 1476 * delivery. 1477 */ 1478 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1479 for (has_sig = 0; !has_sig;) { 1480 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1481 0) == 0) 1482 /* void */; 1483 thread_suspend_check(0); 1484 mtx_lock(&p->p_sigacts->ps_mtx); 1485 while ((sig = cursig(td, SIG_STOP_ALLOWED)) != 0) 1486 has_sig += postsig(sig); 1487 mtx_unlock(&p->p_sigacts->ps_mtx); 1488 } 1489 PROC_UNLOCK(p); 1490 return (EJUSTRETURN); 1491 } 1492 1493 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1494 /* 1495 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1496 * convention: libc stub passes mask, not pointer, to save a copyin. 1497 */ 1498 #ifndef _SYS_SYSPROTO_H_ 1499 struct osigsuspend_args { 1500 osigset_t mask; 1501 }; 1502 #endif 1503 /* ARGSUSED */ 1504 int 1505 osigsuspend(td, uap) 1506 struct thread *td; 1507 struct osigsuspend_args *uap; 1508 { 1509 sigset_t mask; 1510 1511 OSIG2SIG(uap->mask, mask); 1512 return (kern_sigsuspend(td, mask)); 1513 } 1514 #endif /* COMPAT_43 */ 1515 1516 #if defined(COMPAT_43) 1517 #ifndef _SYS_SYSPROTO_H_ 1518 struct osigstack_args { 1519 struct sigstack *nss; 1520 struct sigstack *oss; 1521 }; 1522 #endif 1523 /* ARGSUSED */ 1524 int 1525 osigstack(td, uap) 1526 struct thread *td; 1527 register struct osigstack_args *uap; 1528 { 1529 struct sigstack nss, oss; 1530 int error = 0; 1531 1532 if (uap->nss != NULL) { 1533 error = copyin(uap->nss, &nss, sizeof(nss)); 1534 if (error) 1535 return (error); 1536 } 1537 oss.ss_sp = td->td_sigstk.ss_sp; 1538 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1539 if (uap->nss != NULL) { 1540 td->td_sigstk.ss_sp = nss.ss_sp; 1541 td->td_sigstk.ss_size = 0; 1542 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1543 td->td_pflags |= TDP_ALTSTACK; 1544 } 1545 if (uap->oss != NULL) 1546 error = copyout(&oss, uap->oss, sizeof(oss)); 1547 1548 return (error); 1549 } 1550 #endif /* COMPAT_43 */ 1551 1552 #ifndef _SYS_SYSPROTO_H_ 1553 struct sigaltstack_args { 1554 stack_t *ss; 1555 stack_t *oss; 1556 }; 1557 #endif 1558 /* ARGSUSED */ 1559 int 1560 sigaltstack(td, uap) 1561 struct thread *td; 1562 register struct sigaltstack_args *uap; 1563 { 1564 stack_t ss, oss; 1565 int error; 1566 1567 if (uap->ss != NULL) { 1568 error = copyin(uap->ss, &ss, sizeof(ss)); 1569 if (error) 1570 return (error); 1571 } 1572 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1573 (uap->oss != NULL) ? &oss : NULL); 1574 if (error) 1575 return (error); 1576 if (uap->oss != NULL) 1577 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1578 return (error); 1579 } 1580 1581 int 1582 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1583 { 1584 struct proc *p = td->td_proc; 1585 int oonstack; 1586 1587 oonstack = sigonstack(cpu_getstack(td)); 1588 1589 if (oss != NULL) { 1590 *oss = td->td_sigstk; 1591 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1592 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1593 } 1594 1595 if (ss != NULL) { 1596 if (oonstack) 1597 return (EPERM); 1598 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1599 return (EINVAL); 1600 if (!(ss->ss_flags & SS_DISABLE)) { 1601 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1602 return (ENOMEM); 1603 1604 td->td_sigstk = *ss; 1605 td->td_pflags |= TDP_ALTSTACK; 1606 } else { 1607 td->td_pflags &= ~TDP_ALTSTACK; 1608 } 1609 } 1610 return (0); 1611 } 1612 1613 /* 1614 * Common code for kill process group/broadcast kill. 1615 * cp is calling process. 1616 */ 1617 static int 1618 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1619 { 1620 struct proc *p; 1621 struct pgrp *pgrp; 1622 int nfound = 0; 1623 1624 if (all) { 1625 /* 1626 * broadcast 1627 */ 1628 sx_slock(&allproc_lock); 1629 FOREACH_PROC_IN_SYSTEM(p) { 1630 PROC_LOCK(p); 1631 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1632 p == td->td_proc || p->p_state == PRS_NEW) { 1633 PROC_UNLOCK(p); 1634 continue; 1635 } 1636 if (p_cansignal(td, p, sig) == 0) { 1637 nfound++; 1638 if (sig) 1639 pksignal(p, sig, ksi); 1640 } 1641 PROC_UNLOCK(p); 1642 } 1643 sx_sunlock(&allproc_lock); 1644 } else { 1645 sx_slock(&proctree_lock); 1646 if (pgid == 0) { 1647 /* 1648 * zero pgid means send to my process group. 1649 */ 1650 pgrp = td->td_proc->p_pgrp; 1651 PGRP_LOCK(pgrp); 1652 } else { 1653 pgrp = pgfind(pgid); 1654 if (pgrp == NULL) { 1655 sx_sunlock(&proctree_lock); 1656 return (ESRCH); 1657 } 1658 } 1659 sx_sunlock(&proctree_lock); 1660 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1661 PROC_LOCK(p); 1662 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1663 p->p_state == PRS_NEW ) { 1664 PROC_UNLOCK(p); 1665 continue; 1666 } 1667 if (p_cansignal(td, p, sig) == 0) { 1668 nfound++; 1669 if (sig) 1670 pksignal(p, sig, ksi); 1671 } 1672 PROC_UNLOCK(p); 1673 } 1674 PGRP_UNLOCK(pgrp); 1675 } 1676 return (nfound ? 0 : ESRCH); 1677 } 1678 1679 #ifndef _SYS_SYSPROTO_H_ 1680 struct kill_args { 1681 int pid; 1682 int signum; 1683 }; 1684 #endif 1685 /* ARGSUSED */ 1686 int 1687 kill(struct thread *td, struct kill_args *uap) 1688 { 1689 ksiginfo_t ksi; 1690 struct proc *p; 1691 int error; 1692 1693 AUDIT_ARG_SIGNUM(uap->signum); 1694 AUDIT_ARG_PID(uap->pid); 1695 if ((u_int)uap->signum > _SIG_MAXSIG) 1696 return (EINVAL); 1697 1698 ksiginfo_init(&ksi); 1699 ksi.ksi_signo = uap->signum; 1700 ksi.ksi_code = SI_USER; 1701 ksi.ksi_pid = td->td_proc->p_pid; 1702 ksi.ksi_uid = td->td_ucred->cr_ruid; 1703 1704 if (uap->pid > 0) { 1705 /* kill single process */ 1706 if ((p = pfind(uap->pid)) == NULL) { 1707 if ((p = zpfind(uap->pid)) == NULL) 1708 return (ESRCH); 1709 } 1710 AUDIT_ARG_PROCESS(p); 1711 error = p_cansignal(td, p, uap->signum); 1712 if (error == 0 && uap->signum) 1713 pksignal(p, uap->signum, &ksi); 1714 PROC_UNLOCK(p); 1715 return (error); 1716 } 1717 switch (uap->pid) { 1718 case -1: /* broadcast signal */ 1719 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1720 case 0: /* signal own process group */ 1721 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1722 default: /* negative explicit process group */ 1723 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1724 } 1725 /* NOTREACHED */ 1726 } 1727 1728 #if defined(COMPAT_43) 1729 #ifndef _SYS_SYSPROTO_H_ 1730 struct okillpg_args { 1731 int pgid; 1732 int signum; 1733 }; 1734 #endif 1735 /* ARGSUSED */ 1736 int 1737 okillpg(struct thread *td, struct okillpg_args *uap) 1738 { 1739 ksiginfo_t ksi; 1740 1741 AUDIT_ARG_SIGNUM(uap->signum); 1742 AUDIT_ARG_PID(uap->pgid); 1743 if ((u_int)uap->signum > _SIG_MAXSIG) 1744 return (EINVAL); 1745 1746 ksiginfo_init(&ksi); 1747 ksi.ksi_signo = uap->signum; 1748 ksi.ksi_code = SI_USER; 1749 ksi.ksi_pid = td->td_proc->p_pid; 1750 ksi.ksi_uid = td->td_ucred->cr_ruid; 1751 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1752 } 1753 #endif /* COMPAT_43 */ 1754 1755 #ifndef _SYS_SYSPROTO_H_ 1756 struct sigqueue_args { 1757 pid_t pid; 1758 int signum; 1759 /* union sigval */ void *value; 1760 }; 1761 #endif 1762 int 1763 sigqueue(struct thread *td, struct sigqueue_args *uap) 1764 { 1765 ksiginfo_t ksi; 1766 struct proc *p; 1767 int error; 1768 1769 if ((u_int)uap->signum > _SIG_MAXSIG) 1770 return (EINVAL); 1771 1772 /* 1773 * Specification says sigqueue can only send signal to 1774 * single process. 1775 */ 1776 if (uap->pid <= 0) 1777 return (EINVAL); 1778 1779 if ((p = pfind(uap->pid)) == NULL) { 1780 if ((p = zpfind(uap->pid)) == NULL) 1781 return (ESRCH); 1782 } 1783 error = p_cansignal(td, p, uap->signum); 1784 if (error == 0 && uap->signum != 0) { 1785 ksiginfo_init(&ksi); 1786 ksi.ksi_flags = KSI_SIGQ; 1787 ksi.ksi_signo = uap->signum; 1788 ksi.ksi_code = SI_QUEUE; 1789 ksi.ksi_pid = td->td_proc->p_pid; 1790 ksi.ksi_uid = td->td_ucred->cr_ruid; 1791 ksi.ksi_value.sival_ptr = uap->value; 1792 error = tdsignal(p, NULL, ksi.ksi_signo, &ksi); 1793 } 1794 PROC_UNLOCK(p); 1795 return (error); 1796 } 1797 1798 /* 1799 * Send a signal to a process group. 1800 */ 1801 void 1802 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1803 { 1804 struct pgrp *pgrp; 1805 1806 if (pgid != 0) { 1807 sx_slock(&proctree_lock); 1808 pgrp = pgfind(pgid); 1809 sx_sunlock(&proctree_lock); 1810 if (pgrp != NULL) { 1811 pgsignal(pgrp, sig, 0, ksi); 1812 PGRP_UNLOCK(pgrp); 1813 } 1814 } 1815 } 1816 1817 /* 1818 * Send a signal to a process group. If checktty is 1, 1819 * limit to members which have a controlling terminal. 1820 */ 1821 void 1822 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1823 { 1824 struct proc *p; 1825 1826 if (pgrp) { 1827 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1828 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1829 PROC_LOCK(p); 1830 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1831 pksignal(p, sig, ksi); 1832 PROC_UNLOCK(p); 1833 } 1834 } 1835 } 1836 1837 /* 1838 * Send a signal caused by a trap to the current thread. If it will be 1839 * caught immediately, deliver it with correct code. Otherwise, post it 1840 * normally. 1841 */ 1842 void 1843 trapsignal(struct thread *td, ksiginfo_t *ksi) 1844 { 1845 struct sigacts *ps; 1846 sigset_t mask; 1847 struct proc *p; 1848 int sig; 1849 int code; 1850 1851 p = td->td_proc; 1852 sig = ksi->ksi_signo; 1853 code = ksi->ksi_code; 1854 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1855 1856 PROC_LOCK(p); 1857 ps = p->p_sigacts; 1858 mtx_lock(&ps->ps_mtx); 1859 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1860 !SIGISMEMBER(td->td_sigmask, sig)) { 1861 td->td_ru.ru_nsignals++; 1862 #ifdef KTRACE 1863 if (KTRPOINT(curthread, KTR_PSIG)) 1864 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1865 &td->td_sigmask, code); 1866 #endif 1867 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1868 ksi, &td->td_sigmask); 1869 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1870 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1871 SIGADDSET(mask, sig); 1872 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1873 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1874 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1875 /* 1876 * See kern_sigaction() for origin of this code. 1877 */ 1878 SIGDELSET(ps->ps_sigcatch, sig); 1879 if (sig != SIGCONT && 1880 sigprop(sig) & SA_IGNORE) 1881 SIGADDSET(ps->ps_sigignore, sig); 1882 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1883 } 1884 mtx_unlock(&ps->ps_mtx); 1885 } else { 1886 /* 1887 * Avoid a possible infinite loop if the thread 1888 * masking the signal or process is ignoring the 1889 * signal. 1890 */ 1891 if (kern_forcesigexit && 1892 (SIGISMEMBER(td->td_sigmask, sig) || 1893 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1894 SIGDELSET(td->td_sigmask, sig); 1895 SIGDELSET(ps->ps_sigcatch, sig); 1896 SIGDELSET(ps->ps_sigignore, sig); 1897 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1898 } 1899 mtx_unlock(&ps->ps_mtx); 1900 p->p_code = code; /* XXX for core dump/debugger */ 1901 p->p_sig = sig; /* XXX to verify code */ 1902 tdsignal(p, td, sig, ksi); 1903 } 1904 PROC_UNLOCK(p); 1905 } 1906 1907 static struct thread * 1908 sigtd(struct proc *p, int sig, int prop) 1909 { 1910 struct thread *td, *signal_td; 1911 1912 PROC_LOCK_ASSERT(p, MA_OWNED); 1913 1914 /* 1915 * Check if current thread can handle the signal without 1916 * switching context to another thread. 1917 */ 1918 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1919 return (curthread); 1920 signal_td = NULL; 1921 FOREACH_THREAD_IN_PROC(p, td) { 1922 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1923 signal_td = td; 1924 break; 1925 } 1926 } 1927 if (signal_td == NULL) 1928 signal_td = FIRST_THREAD_IN_PROC(p); 1929 return (signal_td); 1930 } 1931 1932 /* 1933 * Send the signal to the process. If the signal has an action, the action 1934 * is usually performed by the target process rather than the caller; we add 1935 * the signal to the set of pending signals for the process. 1936 * 1937 * Exceptions: 1938 * o When a stop signal is sent to a sleeping process that takes the 1939 * default action, the process is stopped without awakening it. 1940 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1941 * regardless of the signal action (eg, blocked or ignored). 1942 * 1943 * Other ignored signals are discarded immediately. 1944 * 1945 * NB: This function may be entered from the debugger via the "kill" DDB 1946 * command. There is little that can be done to mitigate the possibly messy 1947 * side effects of this unwise possibility. 1948 */ 1949 void 1950 psignal(struct proc *p, int sig) 1951 { 1952 ksiginfo_t ksi; 1953 1954 ksiginfo_init(&ksi); 1955 ksi.ksi_signo = sig; 1956 ksi.ksi_code = SI_KERNEL; 1957 (void) tdsignal(p, NULL, sig, &ksi); 1958 } 1959 1960 void 1961 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 1962 { 1963 1964 (void) tdsignal(p, NULL, sig, ksi); 1965 } 1966 1967 int 1968 psignal_event(struct proc *p, struct sigevent *sigev, ksiginfo_t *ksi) 1969 { 1970 struct thread *td = NULL; 1971 1972 PROC_LOCK_ASSERT(p, MA_OWNED); 1973 1974 KASSERT(!KSI_ONQ(ksi), ("psignal_event: ksi on queue")); 1975 1976 /* 1977 * ksi_code and other fields should be set before 1978 * calling this function. 1979 */ 1980 ksi->ksi_signo = sigev->sigev_signo; 1981 ksi->ksi_value = sigev->sigev_value; 1982 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 1983 td = thread_find(p, sigev->sigev_notify_thread_id); 1984 if (td == NULL) 1985 return (ESRCH); 1986 } 1987 return (tdsignal(p, td, ksi->ksi_signo, ksi)); 1988 } 1989 1990 void 1991 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 1992 { 1993 ksiginfo_t ksi_thunk; 1994 1995 /* 1996 * If ksi is NULL, use ksi_thunk and provide semantics 1997 * identical to tdsignal() in 9.0+. 1998 */ 1999 if (ksi == NULL) { 2000 ksi = &ksi_thunk; 2001 ksiginfo_init(ksi); 2002 ksi->ksi_signo = sig; 2003 ksi->ksi_code = SI_KERNEL; 2004 } 2005 (void) tdsignal(td->td_proc, td, sig, ksi); 2006 } 2007 2008 int 2009 tdsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2010 { 2011 sig_t action; 2012 sigqueue_t *sigqueue; 2013 int prop; 2014 struct sigacts *ps; 2015 int intrval; 2016 int ret = 0; 2017 int wakeup_swapper; 2018 2019 PROC_LOCK_ASSERT(p, MA_OWNED); 2020 2021 if (!_SIG_VALID(sig)) 2022 panic("tdsignal(): invalid signal %d", sig); 2023 2024 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("tdsignal: ksi on queue")); 2025 2026 /* 2027 * IEEE Std 1003.1-2001: return success when killing a zombie. 2028 */ 2029 if (p->p_state == PRS_ZOMBIE) { 2030 if (ksi && (ksi->ksi_flags & KSI_INS)) 2031 ksiginfo_tryfree(ksi); 2032 return (ret); 2033 } 2034 2035 ps = p->p_sigacts; 2036 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2037 prop = sigprop(sig); 2038 2039 if (td == NULL) { 2040 td = sigtd(p, sig, prop); 2041 sigqueue = &p->p_sigqueue; 2042 } else { 2043 KASSERT(td->td_proc == p, ("invalid thread")); 2044 sigqueue = &td->td_sigqueue; 2045 } 2046 2047 SDT_PROBE(proc, kernel, , signal_send, td, p, sig, 0, 0 ); 2048 2049 /* 2050 * If the signal is being ignored, 2051 * then we forget about it immediately. 2052 * (Note: we don't set SIGCONT in ps_sigignore, 2053 * and if it is set to SIG_IGN, 2054 * action will be SIG_DFL here.) 2055 */ 2056 mtx_lock(&ps->ps_mtx); 2057 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2058 SDT_PROBE(proc, kernel, , signal_discard, ps, td, sig, 0, 0 ); 2059 2060 mtx_unlock(&ps->ps_mtx); 2061 if (ksi && (ksi->ksi_flags & KSI_INS)) 2062 ksiginfo_tryfree(ksi); 2063 return (ret); 2064 } 2065 if (SIGISMEMBER(td->td_sigmask, sig)) 2066 action = SIG_HOLD; 2067 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2068 action = SIG_CATCH; 2069 else 2070 action = SIG_DFL; 2071 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2072 intrval = EINTR; 2073 else 2074 intrval = ERESTART; 2075 mtx_unlock(&ps->ps_mtx); 2076 2077 if (prop & SA_CONT) 2078 sigqueue_delete_stopmask_proc(p); 2079 else if (prop & SA_STOP) { 2080 /* 2081 * If sending a tty stop signal to a member of an orphaned 2082 * process group, discard the signal here if the action 2083 * is default; don't stop the process below if sleeping, 2084 * and don't clear any pending SIGCONT. 2085 */ 2086 if ((prop & SA_TTYSTOP) && 2087 (p->p_pgrp->pg_jobc == 0) && 2088 (action == SIG_DFL)) { 2089 if (ksi && (ksi->ksi_flags & KSI_INS)) 2090 ksiginfo_tryfree(ksi); 2091 return (ret); 2092 } 2093 sigqueue_delete_proc(p, SIGCONT); 2094 if (p->p_flag & P_CONTINUED) { 2095 p->p_flag &= ~P_CONTINUED; 2096 PROC_LOCK(p->p_pptr); 2097 sigqueue_take(p->p_ksi); 2098 PROC_UNLOCK(p->p_pptr); 2099 } 2100 } 2101 2102 ret = sigqueue_add(sigqueue, sig, ksi); 2103 if (ret != 0) 2104 return (ret); 2105 signotify(td); 2106 /* 2107 * Defer further processing for signals which are held, 2108 * except that stopped processes must be continued by SIGCONT. 2109 */ 2110 if (action == SIG_HOLD && 2111 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2112 return (ret); 2113 /* 2114 * SIGKILL: Remove procfs STOPEVENTs. 2115 */ 2116 if (sig == SIGKILL) { 2117 /* from procfs_ioctl.c: PIOCBIC */ 2118 p->p_stops = 0; 2119 /* from procfs_ioctl.c: PIOCCONT */ 2120 p->p_step = 0; 2121 wakeup(&p->p_step); 2122 } 2123 /* 2124 * Some signals have a process-wide effect and a per-thread 2125 * component. Most processing occurs when the process next 2126 * tries to cross the user boundary, however there are some 2127 * times when processing needs to be done immediatly, such as 2128 * waking up threads so that they can cross the user boundary. 2129 * We try do the per-process part here. 2130 */ 2131 if (P_SHOULDSTOP(p)) { 2132 if (sig == SIGKILL) { 2133 /* 2134 * If traced process is already stopped, 2135 * then no further action is necessary. 2136 */ 2137 if (p->p_flag & P_TRACED) 2138 goto out; 2139 /* 2140 * SIGKILL sets process running. 2141 * It will die elsewhere. 2142 * All threads must be restarted. 2143 */ 2144 p->p_flag &= ~P_STOPPED_SIG; 2145 goto runfast; 2146 } 2147 2148 if (prop & SA_CONT) { 2149 /* 2150 * If traced process is already stopped, 2151 * then no further action is necessary. 2152 */ 2153 if (p->p_flag & P_TRACED) 2154 goto out; 2155 /* 2156 * If SIGCONT is default (or ignored), we continue the 2157 * process but don't leave the signal in sigqueue as 2158 * it has no further action. If SIGCONT is held, we 2159 * continue the process and leave the signal in 2160 * sigqueue. If the process catches SIGCONT, let it 2161 * handle the signal itself. If it isn't waiting on 2162 * an event, it goes back to run state. 2163 * Otherwise, process goes back to sleep state. 2164 */ 2165 p->p_flag &= ~P_STOPPED_SIG; 2166 PROC_SLOCK(p); 2167 if (p->p_numthreads == p->p_suspcount) { 2168 PROC_SUNLOCK(p); 2169 p->p_flag |= P_CONTINUED; 2170 p->p_xstat = SIGCONT; 2171 PROC_LOCK(p->p_pptr); 2172 childproc_continued(p); 2173 PROC_UNLOCK(p->p_pptr); 2174 PROC_SLOCK(p); 2175 } 2176 if (action == SIG_DFL) { 2177 thread_unsuspend(p); 2178 PROC_SUNLOCK(p); 2179 sigqueue_delete(sigqueue, sig); 2180 goto out; 2181 } 2182 if (action == SIG_CATCH) { 2183 /* 2184 * The process wants to catch it so it needs 2185 * to run at least one thread, but which one? 2186 */ 2187 PROC_SUNLOCK(p); 2188 goto runfast; 2189 } 2190 /* 2191 * The signal is not ignored or caught. 2192 */ 2193 thread_unsuspend(p); 2194 PROC_SUNLOCK(p); 2195 goto out; 2196 } 2197 2198 if (prop & SA_STOP) { 2199 /* 2200 * If traced process is already stopped, 2201 * then no further action is necessary. 2202 */ 2203 if (p->p_flag & P_TRACED) 2204 goto out; 2205 /* 2206 * Already stopped, don't need to stop again 2207 * (If we did the shell could get confused). 2208 * Just make sure the signal STOP bit set. 2209 */ 2210 p->p_flag |= P_STOPPED_SIG; 2211 sigqueue_delete(sigqueue, sig); 2212 goto out; 2213 } 2214 2215 /* 2216 * All other kinds of signals: 2217 * If a thread is sleeping interruptibly, simulate a 2218 * wakeup so that when it is continued it will be made 2219 * runnable and can look at the signal. However, don't make 2220 * the PROCESS runnable, leave it stopped. 2221 * It may run a bit until it hits a thread_suspend_check(). 2222 */ 2223 wakeup_swapper = 0; 2224 PROC_SLOCK(p); 2225 thread_lock(td); 2226 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2227 wakeup_swapper = sleepq_abort(td, intrval); 2228 thread_unlock(td); 2229 PROC_SUNLOCK(p); 2230 if (wakeup_swapper) 2231 kick_proc0(); 2232 goto out; 2233 /* 2234 * Mutexes are short lived. Threads waiting on them will 2235 * hit thread_suspend_check() soon. 2236 */ 2237 } else if (p->p_state == PRS_NORMAL) { 2238 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2239 tdsigwakeup(td, sig, action, intrval); 2240 goto out; 2241 } 2242 2243 MPASS(action == SIG_DFL); 2244 2245 if (prop & SA_STOP) { 2246 if (p->p_flag & P_PPWAIT) 2247 goto out; 2248 p->p_flag |= P_STOPPED_SIG; 2249 p->p_xstat = sig; 2250 PROC_SLOCK(p); 2251 sig_suspend_threads(td, p, 1); 2252 if (p->p_numthreads == p->p_suspcount) { 2253 /* 2254 * only thread sending signal to another 2255 * process can reach here, if thread is sending 2256 * signal to its process, because thread does 2257 * not suspend itself here, p_numthreads 2258 * should never be equal to p_suspcount. 2259 */ 2260 thread_stopped(p); 2261 PROC_SUNLOCK(p); 2262 sigqueue_delete_proc(p, p->p_xstat); 2263 } else 2264 PROC_SUNLOCK(p); 2265 goto out; 2266 } 2267 } else { 2268 /* Not in "NORMAL" state. discard the signal. */ 2269 sigqueue_delete(sigqueue, sig); 2270 goto out; 2271 } 2272 2273 /* 2274 * The process is not stopped so we need to apply the signal to all the 2275 * running threads. 2276 */ 2277 runfast: 2278 tdsigwakeup(td, sig, action, intrval); 2279 PROC_SLOCK(p); 2280 thread_unsuspend(p); 2281 PROC_SUNLOCK(p); 2282 out: 2283 /* If we jump here, proc slock should not be owned. */ 2284 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2285 return (ret); 2286 } 2287 2288 /* 2289 * The force of a signal has been directed against a single 2290 * thread. We need to see what we can do about knocking it 2291 * out of any sleep it may be in etc. 2292 */ 2293 static void 2294 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2295 { 2296 struct proc *p = td->td_proc; 2297 register int prop; 2298 int wakeup_swapper; 2299 2300 wakeup_swapper = 0; 2301 PROC_LOCK_ASSERT(p, MA_OWNED); 2302 prop = sigprop(sig); 2303 2304 PROC_SLOCK(p); 2305 thread_lock(td); 2306 /* 2307 * Bring the priority of a thread up if we want it to get 2308 * killed in this lifetime. 2309 */ 2310 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER) 2311 sched_prio(td, PUSER); 2312 if (TD_ON_SLEEPQ(td)) { 2313 /* 2314 * If thread is sleeping uninterruptibly 2315 * we can't interrupt the sleep... the signal will 2316 * be noticed when the process returns through 2317 * trap() or syscall(). 2318 */ 2319 if ((td->td_flags & TDF_SINTR) == 0) 2320 goto out; 2321 /* 2322 * If SIGCONT is default (or ignored) and process is 2323 * asleep, we are finished; the process should not 2324 * be awakened. 2325 */ 2326 if ((prop & SA_CONT) && action == SIG_DFL) { 2327 thread_unlock(td); 2328 PROC_SUNLOCK(p); 2329 sigqueue_delete(&p->p_sigqueue, sig); 2330 /* 2331 * It may be on either list in this state. 2332 * Remove from both for now. 2333 */ 2334 sigqueue_delete(&td->td_sigqueue, sig); 2335 return; 2336 } 2337 2338 /* 2339 * Give low priority threads a better chance to run. 2340 */ 2341 if (td->td_priority > PUSER) 2342 sched_prio(td, PUSER); 2343 2344 wakeup_swapper = sleepq_abort(td, intrval); 2345 } else { 2346 /* 2347 * Other states do nothing with the signal immediately, 2348 * other than kicking ourselves if we are running. 2349 * It will either never be noticed, or noticed very soon. 2350 */ 2351 #ifdef SMP 2352 if (TD_IS_RUNNING(td) && td != curthread) 2353 forward_signal(td); 2354 #endif 2355 } 2356 out: 2357 PROC_SUNLOCK(p); 2358 thread_unlock(td); 2359 if (wakeup_swapper) 2360 kick_proc0(); 2361 } 2362 2363 static void 2364 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2365 { 2366 struct thread *td2; 2367 int wakeup_swapper; 2368 2369 PROC_LOCK_ASSERT(p, MA_OWNED); 2370 PROC_SLOCK_ASSERT(p, MA_OWNED); 2371 2372 wakeup_swapper = 0; 2373 FOREACH_THREAD_IN_PROC(p, td2) { 2374 thread_lock(td2); 2375 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2376 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2377 (td2->td_flags & TDF_SINTR)) { 2378 if (td2->td_flags & TDF_SBDRY) { 2379 if (TD_IS_SUSPENDED(td2)) 2380 wakeup_swapper |= 2381 thread_unsuspend_one(td2); 2382 if (TD_ON_SLEEPQ(td2)) 2383 wakeup_swapper |= 2384 sleepq_abort(td2, ERESTART); 2385 } else if (!TD_IS_SUSPENDED(td2)) { 2386 thread_suspend_one(td2); 2387 } 2388 } else if (!TD_IS_SUSPENDED(td2)) { 2389 if (sending || td != td2) 2390 td2->td_flags |= TDF_ASTPENDING; 2391 #ifdef SMP 2392 if (TD_IS_RUNNING(td2) && td2 != td) 2393 forward_signal(td2); 2394 #endif 2395 } 2396 thread_unlock(td2); 2397 } 2398 if (wakeup_swapper) 2399 kick_proc0(); 2400 } 2401 2402 int 2403 ptracestop(struct thread *td, int sig) 2404 { 2405 struct proc *p = td->td_proc; 2406 2407 PROC_LOCK_ASSERT(p, MA_OWNED); 2408 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2409 &p->p_mtx.lock_object, "Stopping for traced signal"); 2410 2411 td->td_dbgflags |= TDB_XSIG; 2412 td->td_xsig = sig; 2413 PROC_SLOCK(p); 2414 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2415 if (p->p_flag & P_SINGLE_EXIT) { 2416 td->td_dbgflags &= ~TDB_XSIG; 2417 PROC_SUNLOCK(p); 2418 return (sig); 2419 } 2420 /* 2421 * Just make wait() to work, the last stopped thread 2422 * will win. 2423 */ 2424 p->p_xstat = sig; 2425 p->p_xthread = td; 2426 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2427 sig_suspend_threads(td, p, 0); 2428 stopme: 2429 thread_suspend_switch(td); 2430 if (!(p->p_flag & P_TRACED)) { 2431 break; 2432 } 2433 if (td->td_dbgflags & TDB_SUSPEND) { 2434 if (p->p_flag & P_SINGLE_EXIT) 2435 break; 2436 goto stopme; 2437 } 2438 } 2439 PROC_SUNLOCK(p); 2440 return (td->td_xsig); 2441 } 2442 2443 static void 2444 reschedule_signals(struct proc *p, sigset_t block, int flags) 2445 { 2446 struct sigacts *ps; 2447 struct thread *td; 2448 int i; 2449 2450 PROC_LOCK_ASSERT(p, MA_OWNED); 2451 2452 ps = p->p_sigacts; 2453 for (i = 1; !SIGISEMPTY(block); i++) { 2454 if (!SIGISMEMBER(block, i)) 2455 continue; 2456 SIGDELSET(block, i); 2457 if (!SIGISMEMBER(p->p_siglist, i)) 2458 continue; 2459 2460 td = sigtd(p, i, 0); 2461 signotify(td); 2462 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2463 mtx_lock(&ps->ps_mtx); 2464 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, i)) 2465 tdsigwakeup(td, i, SIG_CATCH, 2466 (SIGISMEMBER(ps->ps_sigintr, i) ? EINTR : 2467 ERESTART)); 2468 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2469 mtx_unlock(&ps->ps_mtx); 2470 } 2471 } 2472 2473 void 2474 tdsigcleanup(struct thread *td) 2475 { 2476 struct proc *p; 2477 sigset_t unblocked; 2478 2479 p = td->td_proc; 2480 PROC_LOCK_ASSERT(p, MA_OWNED); 2481 2482 sigqueue_flush(&td->td_sigqueue); 2483 if (p->p_numthreads == 1) 2484 return; 2485 2486 /* 2487 * Since we cannot handle signals, notify signal post code 2488 * about this by filling the sigmask. 2489 * 2490 * Also, if needed, wake up thread(s) that do not block the 2491 * same signals as the exiting thread, since the thread might 2492 * have been selected for delivery and woken up. 2493 */ 2494 SIGFILLSET(unblocked); 2495 SIGSETNAND(unblocked, td->td_sigmask); 2496 SIGFILLSET(td->td_sigmask); 2497 reschedule_signals(p, unblocked, 0); 2498 2499 } 2500 2501 /* 2502 * If the current process has received a signal (should be caught or cause 2503 * termination, should interrupt current syscall), return the signal number. 2504 * Stop signals with default action are processed immediately, then cleared; 2505 * they aren't returned. This is checked after each entry to the system for 2506 * a syscall or trap (though this can usually be done without calling issignal 2507 * by checking the pending signal masks in cursig.) The normal call 2508 * sequence is 2509 * 2510 * while (sig = cursig(curthread)) 2511 * postsig(sig); 2512 */ 2513 static int 2514 issignal(struct thread *td, int stop_allowed) 2515 { 2516 struct proc *p; 2517 struct sigacts *ps; 2518 struct sigqueue *queue; 2519 sigset_t sigpending; 2520 int sig, prop, newsig; 2521 2522 p = td->td_proc; 2523 ps = p->p_sigacts; 2524 mtx_assert(&ps->ps_mtx, MA_OWNED); 2525 PROC_LOCK_ASSERT(p, MA_OWNED); 2526 for (;;) { 2527 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2528 2529 sigpending = td->td_sigqueue.sq_signals; 2530 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2531 SIGSETNAND(sigpending, td->td_sigmask); 2532 2533 if (p->p_flag & P_PPWAIT) 2534 SIG_STOPSIGMASK(sigpending); 2535 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2536 return (0); 2537 sig = sig_ffs(&sigpending); 2538 2539 if (p->p_stops & S_SIG) { 2540 mtx_unlock(&ps->ps_mtx); 2541 stopevent(p, S_SIG, sig); 2542 mtx_lock(&ps->ps_mtx); 2543 } 2544 2545 /* 2546 * We should see pending but ignored signals 2547 * only if P_TRACED was on when they were posted. 2548 */ 2549 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2550 sigqueue_delete(&td->td_sigqueue, sig); 2551 sigqueue_delete(&p->p_sigqueue, sig); 2552 continue; 2553 } 2554 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 2555 /* 2556 * If traced, always stop. 2557 * Remove old signal from queue before the stop. 2558 * XXX shrug off debugger, it causes siginfo to 2559 * be thrown away. 2560 */ 2561 queue = &td->td_sigqueue; 2562 td->td_dbgksi.ksi_signo = 0; 2563 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2564 queue = &p->p_sigqueue; 2565 sigqueue_get(queue, sig, &td->td_dbgksi); 2566 } 2567 2568 mtx_unlock(&ps->ps_mtx); 2569 newsig = ptracestop(td, sig); 2570 mtx_lock(&ps->ps_mtx); 2571 2572 if (sig != newsig) { 2573 2574 /* 2575 * If parent wants us to take the signal, 2576 * then it will leave it in p->p_xstat; 2577 * otherwise we just look for signals again. 2578 */ 2579 if (newsig == 0) 2580 continue; 2581 sig = newsig; 2582 2583 /* 2584 * Put the new signal into td_sigqueue. If the 2585 * signal is being masked, look for other signals. 2586 */ 2587 sigqueue_add(queue, sig, NULL); 2588 if (SIGISMEMBER(td->td_sigmask, sig)) 2589 continue; 2590 signotify(td); 2591 } else { 2592 if (td->td_dbgksi.ksi_signo != 0) { 2593 td->td_dbgksi.ksi_flags |= KSI_HEAD; 2594 if (sigqueue_add(&td->td_sigqueue, sig, 2595 &td->td_dbgksi) != 0) 2596 td->td_dbgksi.ksi_signo = 0; 2597 } 2598 if (td->td_dbgksi.ksi_signo == 0) 2599 sigqueue_add(&td->td_sigqueue, sig, 2600 NULL); 2601 } 2602 2603 /* 2604 * If the traced bit got turned off, go back up 2605 * to the top to rescan signals. This ensures 2606 * that p_sig* and p_sigact are consistent. 2607 */ 2608 if ((p->p_flag & P_TRACED) == 0) 2609 continue; 2610 } 2611 2612 prop = sigprop(sig); 2613 2614 /* 2615 * Decide whether the signal should be returned. 2616 * Return the signal's number, or fall through 2617 * to clear it from the pending mask. 2618 */ 2619 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2620 2621 case (intptr_t)SIG_DFL: 2622 /* 2623 * Don't take default actions on system processes. 2624 */ 2625 if (p->p_pid <= 1) { 2626 #ifdef DIAGNOSTIC 2627 /* 2628 * Are you sure you want to ignore SIGSEGV 2629 * in init? XXX 2630 */ 2631 printf("Process (pid %lu) got signal %d\n", 2632 (u_long)p->p_pid, sig); 2633 #endif 2634 break; /* == ignore */ 2635 } 2636 /* 2637 * If there is a pending stop signal to process 2638 * with default action, stop here, 2639 * then clear the signal. However, 2640 * if process is member of an orphaned 2641 * process group, ignore tty stop signals. 2642 */ 2643 if (prop & SA_STOP) { 2644 if (p->p_flag & P_TRACED || 2645 (p->p_pgrp->pg_jobc == 0 && 2646 prop & SA_TTYSTOP)) 2647 break; /* == ignore */ 2648 2649 /* Ignore, but do not drop the stop signal. */ 2650 if (stop_allowed != SIG_STOP_ALLOWED) 2651 return (sig); 2652 mtx_unlock(&ps->ps_mtx); 2653 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2654 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2655 p->p_flag |= P_STOPPED_SIG; 2656 p->p_xstat = sig; 2657 PROC_SLOCK(p); 2658 sig_suspend_threads(td, p, 0); 2659 thread_suspend_switch(td); 2660 PROC_SUNLOCK(p); 2661 mtx_lock(&ps->ps_mtx); 2662 break; 2663 } else if (prop & SA_IGNORE) { 2664 /* 2665 * Except for SIGCONT, shouldn't get here. 2666 * Default action is to ignore; drop it. 2667 */ 2668 break; /* == ignore */ 2669 } else 2670 return (sig); 2671 /*NOTREACHED*/ 2672 2673 case (intptr_t)SIG_IGN: 2674 /* 2675 * Masking above should prevent us ever trying 2676 * to take action on an ignored signal other 2677 * than SIGCONT, unless process is traced. 2678 */ 2679 if ((prop & SA_CONT) == 0 && 2680 (p->p_flag & P_TRACED) == 0) 2681 printf("issignal\n"); 2682 break; /* == ignore */ 2683 2684 default: 2685 /* 2686 * This signal has an action, let 2687 * postsig() process it. 2688 */ 2689 return (sig); 2690 } 2691 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2692 sigqueue_delete(&p->p_sigqueue, sig); 2693 } 2694 /* NOTREACHED */ 2695 } 2696 2697 void 2698 thread_stopped(struct proc *p) 2699 { 2700 int n; 2701 2702 PROC_LOCK_ASSERT(p, MA_OWNED); 2703 PROC_SLOCK_ASSERT(p, MA_OWNED); 2704 n = p->p_suspcount; 2705 if (p == curproc) 2706 n++; 2707 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2708 PROC_SUNLOCK(p); 2709 p->p_flag &= ~P_WAITED; 2710 PROC_LOCK(p->p_pptr); 2711 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2712 CLD_TRAPPED : CLD_STOPPED); 2713 PROC_UNLOCK(p->p_pptr); 2714 PROC_SLOCK(p); 2715 } 2716 } 2717 2718 /* 2719 * Take the action for the specified signal 2720 * from the current set of pending signals. 2721 */ 2722 int 2723 postsig(sig) 2724 register int sig; 2725 { 2726 struct thread *td = curthread; 2727 register struct proc *p = td->td_proc; 2728 struct sigacts *ps; 2729 sig_t action; 2730 ksiginfo_t ksi; 2731 sigset_t returnmask, mask; 2732 2733 KASSERT(sig != 0, ("postsig")); 2734 2735 PROC_LOCK_ASSERT(p, MA_OWNED); 2736 ps = p->p_sigacts; 2737 mtx_assert(&ps->ps_mtx, MA_OWNED); 2738 ksiginfo_init(&ksi); 2739 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2740 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2741 return (0); 2742 ksi.ksi_signo = sig; 2743 if (ksi.ksi_code == SI_TIMER) 2744 itimer_accept(p, ksi.ksi_timerid, &ksi); 2745 action = ps->ps_sigact[_SIG_IDX(sig)]; 2746 #ifdef KTRACE 2747 if (KTRPOINT(td, KTR_PSIG)) 2748 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2749 &td->td_oldsigmask : &td->td_sigmask, 0); 2750 #endif 2751 if (p->p_stops & S_SIG) { 2752 mtx_unlock(&ps->ps_mtx); 2753 stopevent(p, S_SIG, sig); 2754 mtx_lock(&ps->ps_mtx); 2755 } 2756 2757 if (action == SIG_DFL) { 2758 /* 2759 * Default action, where the default is to kill 2760 * the process. (Other cases were ignored above.) 2761 */ 2762 mtx_unlock(&ps->ps_mtx); 2763 sigexit(td, sig); 2764 /* NOTREACHED */ 2765 } else { 2766 /* 2767 * If we get here, the signal must be caught. 2768 */ 2769 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2770 ("postsig action")); 2771 /* 2772 * Set the new mask value and also defer further 2773 * occurrences of this signal. 2774 * 2775 * Special case: user has done a sigsuspend. Here the 2776 * current mask is not of interest, but rather the 2777 * mask from before the sigsuspend is what we want 2778 * restored after the signal processing is completed. 2779 */ 2780 if (td->td_pflags & TDP_OLDMASK) { 2781 returnmask = td->td_oldsigmask; 2782 td->td_pflags &= ~TDP_OLDMASK; 2783 } else 2784 returnmask = td->td_sigmask; 2785 2786 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2787 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2788 SIGADDSET(mask, sig); 2789 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2790 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2791 2792 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2793 /* 2794 * See kern_sigaction() for origin of this code. 2795 */ 2796 SIGDELSET(ps->ps_sigcatch, sig); 2797 if (sig != SIGCONT && 2798 sigprop(sig) & SA_IGNORE) 2799 SIGADDSET(ps->ps_sigignore, sig); 2800 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2801 } 2802 td->td_ru.ru_nsignals++; 2803 if (p->p_sig == sig) { 2804 p->p_code = 0; 2805 p->p_sig = 0; 2806 } 2807 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2808 } 2809 return (1); 2810 } 2811 2812 /* 2813 * Kill the current process for stated reason. 2814 */ 2815 void 2816 killproc(p, why) 2817 struct proc *p; 2818 char *why; 2819 { 2820 2821 PROC_LOCK_ASSERT(p, MA_OWNED); 2822 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2823 p, p->p_pid, p->p_comm); 2824 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2825 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2826 p->p_flag |= P_WKILLED; 2827 psignal(p, SIGKILL); 2828 } 2829 2830 /* 2831 * Force the current process to exit with the specified signal, dumping core 2832 * if appropriate. We bypass the normal tests for masked and caught signals, 2833 * allowing unrecoverable failures to terminate the process without changing 2834 * signal state. Mark the accounting record with the signal termination. 2835 * If dumping core, save the signal number for the debugger. Calls exit and 2836 * does not return. 2837 */ 2838 void 2839 sigexit(td, sig) 2840 struct thread *td; 2841 int sig; 2842 { 2843 struct proc *p = td->td_proc; 2844 2845 PROC_LOCK_ASSERT(p, MA_OWNED); 2846 p->p_acflag |= AXSIG; 2847 /* 2848 * We must be single-threading to generate a core dump. This 2849 * ensures that the registers in the core file are up-to-date. 2850 * Also, the ELF dump handler assumes that the thread list doesn't 2851 * change out from under it. 2852 * 2853 * XXX If another thread attempts to single-thread before us 2854 * (e.g. via fork()), we won't get a dump at all. 2855 */ 2856 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2857 p->p_sig = sig; 2858 /* 2859 * Log signals which would cause core dumps 2860 * (Log as LOG_INFO to appease those who don't want 2861 * these messages.) 2862 * XXX : Todo, as well as euid, write out ruid too 2863 * Note that coredump() drops proc lock. 2864 */ 2865 if (coredump(td) == 0) 2866 sig |= WCOREFLAG; 2867 if (kern_logsigexit) 2868 log(LOG_INFO, 2869 "pid %d (%s), uid %d: exited on signal %d%s\n", 2870 p->p_pid, p->p_comm, 2871 td->td_ucred ? td->td_ucred->cr_uid : -1, 2872 sig &~ WCOREFLAG, 2873 sig & WCOREFLAG ? " (core dumped)" : ""); 2874 } else 2875 PROC_UNLOCK(p); 2876 exit1(td, W_EXITCODE(0, sig)); 2877 /* NOTREACHED */ 2878 } 2879 2880 /* 2881 * Send queued SIGCHLD to parent when child process's state 2882 * is changed. 2883 */ 2884 static void 2885 sigparent(struct proc *p, int reason, int status) 2886 { 2887 PROC_LOCK_ASSERT(p, MA_OWNED); 2888 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2889 2890 if (p->p_ksi != NULL) { 2891 p->p_ksi->ksi_signo = SIGCHLD; 2892 p->p_ksi->ksi_code = reason; 2893 p->p_ksi->ksi_status = status; 2894 p->p_ksi->ksi_pid = p->p_pid; 2895 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2896 if (KSI_ONQ(p->p_ksi)) 2897 return; 2898 } 2899 tdsignal(p->p_pptr, NULL, SIGCHLD, p->p_ksi); 2900 } 2901 2902 static void 2903 childproc_jobstate(struct proc *p, int reason, int status) 2904 { 2905 struct sigacts *ps; 2906 2907 PROC_LOCK_ASSERT(p, MA_OWNED); 2908 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2909 2910 /* 2911 * Wake up parent sleeping in kern_wait(), also send 2912 * SIGCHLD to parent, but SIGCHLD does not guarantee 2913 * that parent will awake, because parent may masked 2914 * the signal. 2915 */ 2916 p->p_pptr->p_flag |= P_STATCHILD; 2917 wakeup(p->p_pptr); 2918 2919 ps = p->p_pptr->p_sigacts; 2920 mtx_lock(&ps->ps_mtx); 2921 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2922 mtx_unlock(&ps->ps_mtx); 2923 sigparent(p, reason, status); 2924 } else 2925 mtx_unlock(&ps->ps_mtx); 2926 } 2927 2928 void 2929 childproc_stopped(struct proc *p, int reason) 2930 { 2931 childproc_jobstate(p, reason, p->p_xstat); 2932 } 2933 2934 void 2935 childproc_continued(struct proc *p) 2936 { 2937 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 2938 } 2939 2940 void 2941 childproc_exited(struct proc *p) 2942 { 2943 int reason; 2944 int status = p->p_xstat; /* convert to int */ 2945 2946 reason = CLD_EXITED; 2947 if (WCOREDUMP(status)) 2948 reason = CLD_DUMPED; 2949 else if (WIFSIGNALED(status)) 2950 reason = CLD_KILLED; 2951 /* 2952 * XXX avoid calling wakeup(p->p_pptr), the work is 2953 * done in exit1(). 2954 */ 2955 sigparent(p, reason, status); 2956 } 2957 2958 static char corefilename[MAXPATHLEN] = {"%N.core"}; 2959 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2960 sizeof(corefilename), "process corefile name format string"); 2961 2962 /* 2963 * expand_name(name, uid, pid) 2964 * Expand the name described in corefilename, using name, uid, and pid. 2965 * corefilename is a printf-like string, with three format specifiers: 2966 * %N name of process ("name") 2967 * %P process id (pid) 2968 * %U user id (uid) 2969 * For example, "%N.core" is the default; they can be disabled completely 2970 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2971 * This is controlled by the sysctl variable kern.corefile (see above). 2972 */ 2973 static char * 2974 expand_name(name, uid, pid) 2975 const char *name; 2976 uid_t uid; 2977 pid_t pid; 2978 { 2979 struct sbuf sb; 2980 const char *format; 2981 char *temp; 2982 size_t i; 2983 2984 format = corefilename; 2985 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 2986 if (temp == NULL) 2987 return (NULL); 2988 (void)sbuf_new(&sb, temp, MAXPATHLEN, SBUF_FIXEDLEN); 2989 for (i = 0; format[i]; i++) { 2990 switch (format[i]) { 2991 case '%': /* Format character */ 2992 i++; 2993 switch (format[i]) { 2994 case '%': 2995 sbuf_putc(&sb, '%'); 2996 break; 2997 case 'N': /* process name */ 2998 sbuf_printf(&sb, "%s", name); 2999 break; 3000 case 'P': /* process id */ 3001 sbuf_printf(&sb, "%u", pid); 3002 break; 3003 case 'U': /* user id */ 3004 sbuf_printf(&sb, "%u", uid); 3005 break; 3006 default: 3007 log(LOG_ERR, 3008 "Unknown format character %c in " 3009 "corename `%s'\n", format[i], format); 3010 } 3011 break; 3012 default: 3013 sbuf_putc(&sb, format[i]); 3014 } 3015 } 3016 if (sbuf_overflowed(&sb)) { 3017 sbuf_delete(&sb); 3018 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3019 "long\n", (long)pid, name, (u_long)uid); 3020 free(temp, M_TEMP); 3021 return (NULL); 3022 } 3023 sbuf_finish(&sb); 3024 sbuf_delete(&sb); 3025 return (temp); 3026 } 3027 3028 /* 3029 * Dump a process' core. The main routine does some 3030 * policy checking, and creates the name of the coredump; 3031 * then it passes on a vnode and a size limit to the process-specific 3032 * coredump routine if there is one; if there _is not_ one, it returns 3033 * ENOSYS; otherwise it returns the error from the process-specific routine. 3034 */ 3035 3036 static int 3037 coredump(struct thread *td) 3038 { 3039 struct proc *p = td->td_proc; 3040 register struct vnode *vp; 3041 register struct ucred *cred = td->td_ucred; 3042 struct flock lf; 3043 struct nameidata nd; 3044 struct vattr vattr; 3045 int error, error1, flags, locked; 3046 struct mount *mp; 3047 char *name; /* name of corefile */ 3048 off_t limit; 3049 int vfslocked; 3050 3051 PROC_LOCK_ASSERT(p, MA_OWNED); 3052 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3053 _STOPEVENT(p, S_CORE, 0); 3054 3055 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); 3056 if (name == NULL) { 3057 PROC_UNLOCK(p); 3058 #ifdef AUDIT 3059 audit_proc_coredump(td, NULL, EINVAL); 3060 #endif 3061 return (EINVAL); 3062 } 3063 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 3064 PROC_UNLOCK(p); 3065 #ifdef AUDIT 3066 audit_proc_coredump(td, name, EFAULT); 3067 #endif 3068 free(name, M_TEMP); 3069 return (EFAULT); 3070 } 3071 3072 /* 3073 * Note that the bulk of limit checking is done after 3074 * the corefile is created. The exception is if the limit 3075 * for corefiles is 0, in which case we don't bother 3076 * creating the corefile at all. This layout means that 3077 * a corefile is truncated instead of not being created, 3078 * if it is larger than the limit. 3079 */ 3080 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3081 PROC_UNLOCK(p); 3082 if (limit == 0) { 3083 #ifdef AUDIT 3084 audit_proc_coredump(td, name, EFBIG); 3085 #endif 3086 free(name, M_TEMP); 3087 return (EFBIG); 3088 } 3089 3090 restart: 3091 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, name, td); 3092 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3093 error = vn_open_cred(&nd, &flags, S_IRUSR | S_IWUSR, VN_OPEN_NOAUDIT, 3094 cred, NULL); 3095 if (error) { 3096 #ifdef AUDIT 3097 audit_proc_coredump(td, name, error); 3098 #endif 3099 free(name, M_TEMP); 3100 return (error); 3101 } 3102 vfslocked = NDHASGIANT(&nd); 3103 NDFREE(&nd, NDF_ONLY_PNBUF); 3104 vp = nd.ni_vp; 3105 3106 /* Don't dump to non-regular files or files with links. */ 3107 if (vp->v_type != VREG || 3108 VOP_GETATTR(vp, &vattr, cred) || vattr.va_nlink != 1) { 3109 VOP_UNLOCK(vp, 0); 3110 error = EFAULT; 3111 goto close; 3112 } 3113 3114 VOP_UNLOCK(vp, 0); 3115 lf.l_whence = SEEK_SET; 3116 lf.l_start = 0; 3117 lf.l_len = 0; 3118 lf.l_type = F_WRLCK; 3119 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3120 3121 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3122 lf.l_type = F_UNLCK; 3123 if (locked) 3124 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3125 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3126 goto out; 3127 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3128 goto out; 3129 VFS_UNLOCK_GIANT(vfslocked); 3130 goto restart; 3131 } 3132 3133 VATTR_NULL(&vattr); 3134 vattr.va_size = 0; 3135 if (set_core_nodump_flag) 3136 vattr.va_flags = UF_NODUMP; 3137 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3138 VOP_SETATTR(vp, &vattr, cred); 3139 VOP_UNLOCK(vp, 0); 3140 vn_finished_write(mp); 3141 PROC_LOCK(p); 3142 p->p_acflag |= ACORE; 3143 PROC_UNLOCK(p); 3144 3145 error = p->p_sysent->sv_coredump ? 3146 p->p_sysent->sv_coredump(td, vp, limit) : 3147 ENOSYS; 3148 3149 if (locked) { 3150 lf.l_type = F_UNLCK; 3151 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3152 } 3153 close: 3154 error1 = vn_close(vp, FWRITE, cred, td); 3155 if (error == 0) 3156 error = error1; 3157 out: 3158 #ifdef AUDIT 3159 audit_proc_coredump(td, name, error); 3160 #endif 3161 free(name, M_TEMP); 3162 VFS_UNLOCK_GIANT(vfslocked); 3163 return (error); 3164 } 3165 3166 /* 3167 * Nonexistent system call-- signal process (may want to handle it). Flag 3168 * error in case process won't see signal immediately (blocked or ignored). 3169 */ 3170 #ifndef _SYS_SYSPROTO_H_ 3171 struct nosys_args { 3172 int dummy; 3173 }; 3174 #endif 3175 /* ARGSUSED */ 3176 int 3177 nosys(td, args) 3178 struct thread *td; 3179 struct nosys_args *args; 3180 { 3181 struct proc *p = td->td_proc; 3182 3183 PROC_LOCK(p); 3184 psignal(p, SIGSYS); 3185 PROC_UNLOCK(p); 3186 return (ENOSYS); 3187 } 3188 3189 /* 3190 * Send a SIGIO or SIGURG signal to a process or process group using stored 3191 * credentials rather than those of the current process. 3192 */ 3193 void 3194 pgsigio(sigiop, sig, checkctty) 3195 struct sigio **sigiop; 3196 int sig, checkctty; 3197 { 3198 ksiginfo_t ksi; 3199 struct sigio *sigio; 3200 3201 ksiginfo_init(&ksi); 3202 ksi.ksi_signo = sig; 3203 ksi.ksi_code = SI_KERNEL; 3204 3205 SIGIO_LOCK(); 3206 sigio = *sigiop; 3207 if (sigio == NULL) { 3208 SIGIO_UNLOCK(); 3209 return; 3210 } 3211 if (sigio->sio_pgid > 0) { 3212 PROC_LOCK(sigio->sio_proc); 3213 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3214 psignal(sigio->sio_proc, sig); 3215 PROC_UNLOCK(sigio->sio_proc); 3216 } else if (sigio->sio_pgid < 0) { 3217 struct proc *p; 3218 3219 PGRP_LOCK(sigio->sio_pgrp); 3220 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3221 PROC_LOCK(p); 3222 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3223 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3224 psignal(p, sig); 3225 PROC_UNLOCK(p); 3226 } 3227 PGRP_UNLOCK(sigio->sio_pgrp); 3228 } 3229 SIGIO_UNLOCK(); 3230 } 3231 3232 static int 3233 filt_sigattach(struct knote *kn) 3234 { 3235 struct proc *p = curproc; 3236 3237 kn->kn_ptr.p_proc = p; 3238 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3239 3240 knlist_add(&p->p_klist, kn, 0); 3241 3242 return (0); 3243 } 3244 3245 static void 3246 filt_sigdetach(struct knote *kn) 3247 { 3248 struct proc *p = kn->kn_ptr.p_proc; 3249 3250 knlist_remove(&p->p_klist, kn, 0); 3251 } 3252 3253 /* 3254 * signal knotes are shared with proc knotes, so we apply a mask to 3255 * the hint in order to differentiate them from process hints. This 3256 * could be avoided by using a signal-specific knote list, but probably 3257 * isn't worth the trouble. 3258 */ 3259 static int 3260 filt_signal(struct knote *kn, long hint) 3261 { 3262 3263 if (hint & NOTE_SIGNAL) { 3264 hint &= ~NOTE_SIGNAL; 3265 3266 if (kn->kn_id == hint) 3267 kn->kn_data++; 3268 } 3269 return (kn->kn_data != 0); 3270 } 3271 3272 struct sigacts * 3273 sigacts_alloc(void) 3274 { 3275 struct sigacts *ps; 3276 3277 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3278 ps->ps_refcnt = 1; 3279 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3280 return (ps); 3281 } 3282 3283 void 3284 sigacts_free(struct sigacts *ps) 3285 { 3286 3287 mtx_lock(&ps->ps_mtx); 3288 ps->ps_refcnt--; 3289 if (ps->ps_refcnt == 0) { 3290 mtx_destroy(&ps->ps_mtx); 3291 free(ps, M_SUBPROC); 3292 } else 3293 mtx_unlock(&ps->ps_mtx); 3294 } 3295 3296 struct sigacts * 3297 sigacts_hold(struct sigacts *ps) 3298 { 3299 mtx_lock(&ps->ps_mtx); 3300 ps->ps_refcnt++; 3301 mtx_unlock(&ps->ps_mtx); 3302 return (ps); 3303 } 3304 3305 void 3306 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3307 { 3308 3309 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3310 mtx_lock(&src->ps_mtx); 3311 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3312 mtx_unlock(&src->ps_mtx); 3313 } 3314 3315 int 3316 sigacts_shared(struct sigacts *ps) 3317 { 3318 int shared; 3319 3320 mtx_lock(&ps->ps_mtx); 3321 shared = ps->ps_refcnt > 1; 3322 mtx_unlock(&ps->ps_mtx); 3323 return (shared); 3324 }
Cache object: 71f9744decb3d27a219a24c66fbdcdbb
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