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/8.1/sys/kern/kern_sig.c 207596 2010-05-04 05:14:43Z 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 cpu_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 int 1991 tdsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 1992 { 1993 sig_t action; 1994 sigqueue_t *sigqueue; 1995 int prop; 1996 struct sigacts *ps; 1997 int intrval; 1998 int ret = 0; 1999 int wakeup_swapper; 2000 2001 PROC_LOCK_ASSERT(p, MA_OWNED); 2002 2003 if (!_SIG_VALID(sig)) 2004 panic("tdsignal(): invalid signal %d", sig); 2005 2006 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("tdsignal: ksi on queue")); 2007 2008 /* 2009 * IEEE Std 1003.1-2001: return success when killing a zombie. 2010 */ 2011 if (p->p_state == PRS_ZOMBIE) { 2012 if (ksi && (ksi->ksi_flags & KSI_INS)) 2013 ksiginfo_tryfree(ksi); 2014 return (ret); 2015 } 2016 2017 ps = p->p_sigacts; 2018 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2019 prop = sigprop(sig); 2020 2021 if (td == NULL) { 2022 td = sigtd(p, sig, prop); 2023 sigqueue = &p->p_sigqueue; 2024 } else { 2025 KASSERT(td->td_proc == p, ("invalid thread")); 2026 sigqueue = &td->td_sigqueue; 2027 } 2028 2029 SDT_PROBE(proc, kernel, , signal_send, td, p, sig, 0, 0 ); 2030 2031 /* 2032 * If the signal is being ignored, 2033 * then we forget about it immediately. 2034 * (Note: we don't set SIGCONT in ps_sigignore, 2035 * and if it is set to SIG_IGN, 2036 * action will be SIG_DFL here.) 2037 */ 2038 mtx_lock(&ps->ps_mtx); 2039 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2040 SDT_PROBE(proc, kernel, , signal_discard, ps, td, sig, 0, 0 ); 2041 2042 mtx_unlock(&ps->ps_mtx); 2043 if (ksi && (ksi->ksi_flags & KSI_INS)) 2044 ksiginfo_tryfree(ksi); 2045 return (ret); 2046 } 2047 if (SIGISMEMBER(td->td_sigmask, sig)) 2048 action = SIG_HOLD; 2049 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2050 action = SIG_CATCH; 2051 else 2052 action = SIG_DFL; 2053 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2054 intrval = EINTR; 2055 else 2056 intrval = ERESTART; 2057 mtx_unlock(&ps->ps_mtx); 2058 2059 if (prop & SA_CONT) 2060 sigqueue_delete_stopmask_proc(p); 2061 else if (prop & SA_STOP) { 2062 /* 2063 * If sending a tty stop signal to a member of an orphaned 2064 * process group, discard the signal here if the action 2065 * is default; don't stop the process below if sleeping, 2066 * and don't clear any pending SIGCONT. 2067 */ 2068 if ((prop & SA_TTYSTOP) && 2069 (p->p_pgrp->pg_jobc == 0) && 2070 (action == SIG_DFL)) { 2071 if (ksi && (ksi->ksi_flags & KSI_INS)) 2072 ksiginfo_tryfree(ksi); 2073 return (ret); 2074 } 2075 sigqueue_delete_proc(p, SIGCONT); 2076 if (p->p_flag & P_CONTINUED) { 2077 p->p_flag &= ~P_CONTINUED; 2078 PROC_LOCK(p->p_pptr); 2079 sigqueue_take(p->p_ksi); 2080 PROC_UNLOCK(p->p_pptr); 2081 } 2082 } 2083 2084 ret = sigqueue_add(sigqueue, sig, ksi); 2085 if (ret != 0) 2086 return (ret); 2087 signotify(td); 2088 /* 2089 * Defer further processing for signals which are held, 2090 * except that stopped processes must be continued by SIGCONT. 2091 */ 2092 if (action == SIG_HOLD && 2093 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2094 return (ret); 2095 /* 2096 * SIGKILL: Remove procfs STOPEVENTs. 2097 */ 2098 if (sig == SIGKILL) { 2099 /* from procfs_ioctl.c: PIOCBIC */ 2100 p->p_stops = 0; 2101 /* from procfs_ioctl.c: PIOCCONT */ 2102 p->p_step = 0; 2103 wakeup(&p->p_step); 2104 } 2105 /* 2106 * Some signals have a process-wide effect and a per-thread 2107 * component. Most processing occurs when the process next 2108 * tries to cross the user boundary, however there are some 2109 * times when processing needs to be done immediatly, such as 2110 * waking up threads so that they can cross the user boundary. 2111 * We try do the per-process part here. 2112 */ 2113 if (P_SHOULDSTOP(p)) { 2114 /* 2115 * The process is in stopped mode. All the threads should be 2116 * either winding down or already on the suspended queue. 2117 */ 2118 if (p->p_flag & P_TRACED) { 2119 /* 2120 * The traced process is already stopped, 2121 * so no further action is necessary. 2122 * No signal can restart us. 2123 */ 2124 goto out; 2125 } 2126 2127 if (sig == SIGKILL) { 2128 /* 2129 * SIGKILL sets process running. 2130 * It will die elsewhere. 2131 * All threads must be restarted. 2132 */ 2133 p->p_flag &= ~P_STOPPED_SIG; 2134 goto runfast; 2135 } 2136 2137 if (prop & SA_CONT) { 2138 /* 2139 * If SIGCONT is default (or ignored), we continue the 2140 * process but don't leave the signal in sigqueue as 2141 * it has no further action. If SIGCONT is held, we 2142 * continue the process and leave the signal in 2143 * sigqueue. If the process catches SIGCONT, let it 2144 * handle the signal itself. If it isn't waiting on 2145 * an event, it goes back to run state. 2146 * Otherwise, process goes back to sleep state. 2147 */ 2148 p->p_flag &= ~P_STOPPED_SIG; 2149 PROC_SLOCK(p); 2150 if (p->p_numthreads == p->p_suspcount) { 2151 PROC_SUNLOCK(p); 2152 p->p_flag |= P_CONTINUED; 2153 p->p_xstat = SIGCONT; 2154 PROC_LOCK(p->p_pptr); 2155 childproc_continued(p); 2156 PROC_UNLOCK(p->p_pptr); 2157 PROC_SLOCK(p); 2158 } 2159 if (action == SIG_DFL) { 2160 thread_unsuspend(p); 2161 PROC_SUNLOCK(p); 2162 sigqueue_delete(sigqueue, sig); 2163 goto out; 2164 } 2165 if (action == SIG_CATCH) { 2166 /* 2167 * The process wants to catch it so it needs 2168 * to run at least one thread, but which one? 2169 */ 2170 PROC_SUNLOCK(p); 2171 goto runfast; 2172 } 2173 /* 2174 * The signal is not ignored or caught. 2175 */ 2176 thread_unsuspend(p); 2177 PROC_SUNLOCK(p); 2178 goto out; 2179 } 2180 2181 if (prop & SA_STOP) { 2182 /* 2183 * Already stopped, don't need to stop again 2184 * (If we did the shell could get confused). 2185 * Just make sure the signal STOP bit set. 2186 */ 2187 p->p_flag |= P_STOPPED_SIG; 2188 sigqueue_delete(sigqueue, sig); 2189 goto out; 2190 } 2191 2192 /* 2193 * All other kinds of signals: 2194 * If a thread is sleeping interruptibly, simulate a 2195 * wakeup so that when it is continued it will be made 2196 * runnable and can look at the signal. However, don't make 2197 * the PROCESS runnable, leave it stopped. 2198 * It may run a bit until it hits a thread_suspend_check(). 2199 */ 2200 wakeup_swapper = 0; 2201 PROC_SLOCK(p); 2202 thread_lock(td); 2203 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2204 wakeup_swapper = sleepq_abort(td, intrval); 2205 thread_unlock(td); 2206 PROC_SUNLOCK(p); 2207 if (wakeup_swapper) 2208 kick_proc0(); 2209 goto out; 2210 /* 2211 * Mutexes are short lived. Threads waiting on them will 2212 * hit thread_suspend_check() soon. 2213 */ 2214 } else if (p->p_state == PRS_NORMAL) { 2215 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2216 tdsigwakeup(td, sig, action, intrval); 2217 goto out; 2218 } 2219 2220 MPASS(action == SIG_DFL); 2221 2222 if (prop & SA_STOP) { 2223 if (p->p_flag & P_PPWAIT) 2224 goto out; 2225 p->p_flag |= P_STOPPED_SIG; 2226 p->p_xstat = sig; 2227 PROC_SLOCK(p); 2228 sig_suspend_threads(td, p, 1); 2229 if (p->p_numthreads == p->p_suspcount) { 2230 /* 2231 * only thread sending signal to another 2232 * process can reach here, if thread is sending 2233 * signal to its process, because thread does 2234 * not suspend itself here, p_numthreads 2235 * should never be equal to p_suspcount. 2236 */ 2237 thread_stopped(p); 2238 PROC_SUNLOCK(p); 2239 sigqueue_delete_proc(p, p->p_xstat); 2240 } else 2241 PROC_SUNLOCK(p); 2242 goto out; 2243 } 2244 } else { 2245 /* Not in "NORMAL" state. discard the signal. */ 2246 sigqueue_delete(sigqueue, sig); 2247 goto out; 2248 } 2249 2250 /* 2251 * The process is not stopped so we need to apply the signal to all the 2252 * running threads. 2253 */ 2254 runfast: 2255 tdsigwakeup(td, sig, action, intrval); 2256 PROC_SLOCK(p); 2257 thread_unsuspend(p); 2258 PROC_SUNLOCK(p); 2259 out: 2260 /* If we jump here, proc slock should not be owned. */ 2261 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2262 return (ret); 2263 } 2264 2265 /* 2266 * The force of a signal has been directed against a single 2267 * thread. We need to see what we can do about knocking it 2268 * out of any sleep it may be in etc. 2269 */ 2270 static void 2271 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2272 { 2273 struct proc *p = td->td_proc; 2274 register int prop; 2275 int wakeup_swapper; 2276 2277 wakeup_swapper = 0; 2278 PROC_LOCK_ASSERT(p, MA_OWNED); 2279 prop = sigprop(sig); 2280 2281 PROC_SLOCK(p); 2282 thread_lock(td); 2283 /* 2284 * Bring the priority of a thread up if we want it to get 2285 * killed in this lifetime. 2286 */ 2287 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER) 2288 sched_prio(td, PUSER); 2289 if (TD_ON_SLEEPQ(td)) { 2290 /* 2291 * If thread is sleeping uninterruptibly 2292 * we can't interrupt the sleep... the signal will 2293 * be noticed when the process returns through 2294 * trap() or syscall(). 2295 */ 2296 if ((td->td_flags & TDF_SINTR) == 0) 2297 goto out; 2298 /* 2299 * If SIGCONT is default (or ignored) and process is 2300 * asleep, we are finished; the process should not 2301 * be awakened. 2302 */ 2303 if ((prop & SA_CONT) && action == SIG_DFL) { 2304 thread_unlock(td); 2305 PROC_SUNLOCK(p); 2306 sigqueue_delete(&p->p_sigqueue, sig); 2307 /* 2308 * It may be on either list in this state. 2309 * Remove from both for now. 2310 */ 2311 sigqueue_delete(&td->td_sigqueue, sig); 2312 return; 2313 } 2314 2315 /* 2316 * Give low priority threads a better chance to run. 2317 */ 2318 if (td->td_priority > PUSER) 2319 sched_prio(td, PUSER); 2320 2321 wakeup_swapper = sleepq_abort(td, intrval); 2322 } else { 2323 /* 2324 * Other states do nothing with the signal immediately, 2325 * other than kicking ourselves if we are running. 2326 * It will either never be noticed, or noticed very soon. 2327 */ 2328 #ifdef SMP 2329 if (TD_IS_RUNNING(td) && td != curthread) 2330 forward_signal(td); 2331 #endif 2332 } 2333 out: 2334 PROC_SUNLOCK(p); 2335 thread_unlock(td); 2336 if (wakeup_swapper) 2337 kick_proc0(); 2338 } 2339 2340 static void 2341 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2342 { 2343 struct thread *td2; 2344 int wakeup_swapper; 2345 2346 PROC_LOCK_ASSERT(p, MA_OWNED); 2347 PROC_SLOCK_ASSERT(p, MA_OWNED); 2348 2349 wakeup_swapper = 0; 2350 FOREACH_THREAD_IN_PROC(p, td2) { 2351 thread_lock(td2); 2352 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2353 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2354 (td2->td_flags & TDF_SINTR)) { 2355 if (td2->td_flags & TDF_SBDRY) { 2356 if (TD_IS_SUSPENDED(td2)) 2357 wakeup_swapper |= 2358 thread_unsuspend_one(td2); 2359 if (TD_ON_SLEEPQ(td2)) 2360 wakeup_swapper |= 2361 sleepq_abort(td2, ERESTART); 2362 } else if (!TD_IS_SUSPENDED(td2)) { 2363 thread_suspend_one(td2); 2364 } 2365 } else if (!TD_IS_SUSPENDED(td2)) { 2366 if (sending || td != td2) 2367 td2->td_flags |= TDF_ASTPENDING; 2368 #ifdef SMP 2369 if (TD_IS_RUNNING(td2) && td2 != td) 2370 forward_signal(td2); 2371 #endif 2372 } 2373 thread_unlock(td2); 2374 } 2375 if (wakeup_swapper) 2376 kick_proc0(); 2377 } 2378 2379 int 2380 ptracestop(struct thread *td, int sig) 2381 { 2382 struct proc *p = td->td_proc; 2383 2384 PROC_LOCK_ASSERT(p, MA_OWNED); 2385 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2386 &p->p_mtx.lock_object, "Stopping for traced signal"); 2387 2388 td->td_dbgflags |= TDB_XSIG; 2389 td->td_xsig = sig; 2390 PROC_SLOCK(p); 2391 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2392 if (p->p_flag & P_SINGLE_EXIT) { 2393 td->td_dbgflags &= ~TDB_XSIG; 2394 PROC_SUNLOCK(p); 2395 return (sig); 2396 } 2397 /* 2398 * Just make wait() to work, the last stopped thread 2399 * will win. 2400 */ 2401 p->p_xstat = sig; 2402 p->p_xthread = td; 2403 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2404 sig_suspend_threads(td, p, 0); 2405 stopme: 2406 thread_suspend_switch(td); 2407 if (!(p->p_flag & P_TRACED)) { 2408 break; 2409 } 2410 if (td->td_dbgflags & TDB_SUSPEND) { 2411 if (p->p_flag & P_SINGLE_EXIT) 2412 break; 2413 goto stopme; 2414 } 2415 } 2416 PROC_SUNLOCK(p); 2417 return (td->td_xsig); 2418 } 2419 2420 static void 2421 reschedule_signals(struct proc *p, sigset_t block, int flags) 2422 { 2423 struct sigacts *ps; 2424 struct thread *td; 2425 int i; 2426 2427 PROC_LOCK_ASSERT(p, MA_OWNED); 2428 2429 ps = p->p_sigacts; 2430 for (i = 1; !SIGISEMPTY(block); i++) { 2431 if (!SIGISMEMBER(block, i)) 2432 continue; 2433 SIGDELSET(block, i); 2434 if (!SIGISMEMBER(p->p_siglist, i)) 2435 continue; 2436 2437 td = sigtd(p, i, 0); 2438 signotify(td); 2439 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2440 mtx_lock(&ps->ps_mtx); 2441 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, i)) 2442 tdsigwakeup(td, i, SIG_CATCH, 2443 (SIGISMEMBER(ps->ps_sigintr, i) ? EINTR : 2444 ERESTART)); 2445 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2446 mtx_unlock(&ps->ps_mtx); 2447 } 2448 } 2449 2450 void 2451 tdsigcleanup(struct thread *td) 2452 { 2453 struct proc *p; 2454 sigset_t unblocked; 2455 2456 p = td->td_proc; 2457 PROC_LOCK_ASSERT(p, MA_OWNED); 2458 2459 sigqueue_flush(&td->td_sigqueue); 2460 if (p->p_numthreads == 1) 2461 return; 2462 2463 /* 2464 * Since we cannot handle signals, notify signal post code 2465 * about this by filling the sigmask. 2466 * 2467 * Also, if needed, wake up thread(s) that do not block the 2468 * same signals as the exiting thread, since the thread might 2469 * have been selected for delivery and woken up. 2470 */ 2471 SIGFILLSET(unblocked); 2472 SIGSETNAND(unblocked, td->td_sigmask); 2473 SIGFILLSET(td->td_sigmask); 2474 reschedule_signals(p, unblocked, 0); 2475 2476 } 2477 2478 /* 2479 * If the current process has received a signal (should be caught or cause 2480 * termination, should interrupt current syscall), return the signal number. 2481 * Stop signals with default action are processed immediately, then cleared; 2482 * they aren't returned. This is checked after each entry to the system for 2483 * a syscall or trap (though this can usually be done without calling issignal 2484 * by checking the pending signal masks in cursig.) The normal call 2485 * sequence is 2486 * 2487 * while (sig = cursig(curthread)) 2488 * postsig(sig); 2489 */ 2490 static int 2491 issignal(struct thread *td, int stop_allowed) 2492 { 2493 struct proc *p; 2494 struct sigacts *ps; 2495 struct sigqueue *queue; 2496 sigset_t sigpending; 2497 ksiginfo_t ksi; 2498 int sig, prop, newsig; 2499 2500 p = td->td_proc; 2501 ps = p->p_sigacts; 2502 mtx_assert(&ps->ps_mtx, MA_OWNED); 2503 PROC_LOCK_ASSERT(p, MA_OWNED); 2504 for (;;) { 2505 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2506 2507 sigpending = td->td_sigqueue.sq_signals; 2508 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2509 SIGSETNAND(sigpending, td->td_sigmask); 2510 2511 if (p->p_flag & P_PPWAIT) 2512 SIG_STOPSIGMASK(sigpending); 2513 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2514 return (0); 2515 sig = sig_ffs(&sigpending); 2516 2517 if (p->p_stops & S_SIG) { 2518 mtx_unlock(&ps->ps_mtx); 2519 stopevent(p, S_SIG, sig); 2520 mtx_lock(&ps->ps_mtx); 2521 } 2522 2523 /* 2524 * We should see pending but ignored signals 2525 * only if P_TRACED was on when they were posted. 2526 */ 2527 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2528 sigqueue_delete(&td->td_sigqueue, sig); 2529 sigqueue_delete(&p->p_sigqueue, sig); 2530 continue; 2531 } 2532 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 2533 /* 2534 * If traced, always stop. 2535 * Remove old signal from queue before the stop. 2536 * XXX shrug off debugger, it causes siginfo to 2537 * be thrown away. 2538 */ 2539 queue = &td->td_sigqueue; 2540 ksi.ksi_signo = 0; 2541 if (sigqueue_get(queue, sig, &ksi) == 0) { 2542 queue = &p->p_sigqueue; 2543 sigqueue_get(queue, sig, &ksi); 2544 } 2545 2546 mtx_unlock(&ps->ps_mtx); 2547 newsig = ptracestop(td, sig); 2548 mtx_lock(&ps->ps_mtx); 2549 2550 if (sig != newsig) { 2551 2552 /* 2553 * If parent wants us to take the signal, 2554 * then it will leave it in p->p_xstat; 2555 * otherwise we just look for signals again. 2556 */ 2557 if (newsig == 0) 2558 continue; 2559 sig = newsig; 2560 2561 /* 2562 * Put the new signal into td_sigqueue. If the 2563 * signal is being masked, look for other signals. 2564 */ 2565 sigqueue_add(queue, sig, NULL); 2566 if (SIGISMEMBER(td->td_sigmask, sig)) 2567 continue; 2568 signotify(td); 2569 } else { 2570 if (ksi.ksi_signo != 0) { 2571 ksi.ksi_flags |= KSI_HEAD; 2572 if (sigqueue_add(&td->td_sigqueue, sig, 2573 &ksi) != 0) 2574 ksi.ksi_signo = 0; 2575 } 2576 if (ksi.ksi_signo == 0) 2577 sigqueue_add(&td->td_sigqueue, sig, 2578 NULL); 2579 } 2580 2581 /* 2582 * If the traced bit got turned off, go back up 2583 * to the top to rescan signals. This ensures 2584 * that p_sig* and p_sigact are consistent. 2585 */ 2586 if ((p->p_flag & P_TRACED) == 0) 2587 continue; 2588 } 2589 2590 prop = sigprop(sig); 2591 2592 /* 2593 * Decide whether the signal should be returned. 2594 * Return the signal's number, or fall through 2595 * to clear it from the pending mask. 2596 */ 2597 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2598 2599 case (intptr_t)SIG_DFL: 2600 /* 2601 * Don't take default actions on system processes. 2602 */ 2603 if (p->p_pid <= 1) { 2604 #ifdef DIAGNOSTIC 2605 /* 2606 * Are you sure you want to ignore SIGSEGV 2607 * in init? XXX 2608 */ 2609 printf("Process (pid %lu) got signal %d\n", 2610 (u_long)p->p_pid, sig); 2611 #endif 2612 break; /* == ignore */ 2613 } 2614 /* 2615 * If there is a pending stop signal to process 2616 * with default action, stop here, 2617 * then clear the signal. However, 2618 * if process is member of an orphaned 2619 * process group, ignore tty stop signals. 2620 */ 2621 if (prop & SA_STOP) { 2622 if (p->p_flag & P_TRACED || 2623 (p->p_pgrp->pg_jobc == 0 && 2624 prop & SA_TTYSTOP)) 2625 break; /* == ignore */ 2626 2627 /* Ignore, but do not drop the stop signal. */ 2628 if (stop_allowed != SIG_STOP_ALLOWED) 2629 return (sig); 2630 mtx_unlock(&ps->ps_mtx); 2631 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2632 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2633 p->p_flag |= P_STOPPED_SIG; 2634 p->p_xstat = sig; 2635 PROC_SLOCK(p); 2636 sig_suspend_threads(td, p, 0); 2637 thread_suspend_switch(td); 2638 PROC_SUNLOCK(p); 2639 mtx_lock(&ps->ps_mtx); 2640 break; 2641 } else if (prop & SA_IGNORE) { 2642 /* 2643 * Except for SIGCONT, shouldn't get here. 2644 * Default action is to ignore; drop it. 2645 */ 2646 break; /* == ignore */ 2647 } else 2648 return (sig); 2649 /*NOTREACHED*/ 2650 2651 case (intptr_t)SIG_IGN: 2652 /* 2653 * Masking above should prevent us ever trying 2654 * to take action on an ignored signal other 2655 * than SIGCONT, unless process is traced. 2656 */ 2657 if ((prop & SA_CONT) == 0 && 2658 (p->p_flag & P_TRACED) == 0) 2659 printf("issignal\n"); 2660 break; /* == ignore */ 2661 2662 default: 2663 /* 2664 * This signal has an action, let 2665 * postsig() process it. 2666 */ 2667 return (sig); 2668 } 2669 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2670 sigqueue_delete(&p->p_sigqueue, sig); 2671 } 2672 /* NOTREACHED */ 2673 } 2674 2675 void 2676 thread_stopped(struct proc *p) 2677 { 2678 int n; 2679 2680 PROC_LOCK_ASSERT(p, MA_OWNED); 2681 PROC_SLOCK_ASSERT(p, MA_OWNED); 2682 n = p->p_suspcount; 2683 if (p == curproc) 2684 n++; 2685 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2686 PROC_SUNLOCK(p); 2687 p->p_flag &= ~P_WAITED; 2688 PROC_LOCK(p->p_pptr); 2689 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2690 CLD_TRAPPED : CLD_STOPPED); 2691 PROC_UNLOCK(p->p_pptr); 2692 PROC_SLOCK(p); 2693 } 2694 } 2695 2696 /* 2697 * Take the action for the specified signal 2698 * from the current set of pending signals. 2699 */ 2700 int 2701 postsig(sig) 2702 register int sig; 2703 { 2704 struct thread *td = curthread; 2705 register struct proc *p = td->td_proc; 2706 struct sigacts *ps; 2707 sig_t action; 2708 ksiginfo_t ksi; 2709 sigset_t returnmask, mask; 2710 2711 KASSERT(sig != 0, ("postsig")); 2712 2713 PROC_LOCK_ASSERT(p, MA_OWNED); 2714 ps = p->p_sigacts; 2715 mtx_assert(&ps->ps_mtx, MA_OWNED); 2716 ksiginfo_init(&ksi); 2717 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2718 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2719 return (0); 2720 ksi.ksi_signo = sig; 2721 if (ksi.ksi_code == SI_TIMER) 2722 itimer_accept(p, ksi.ksi_timerid, &ksi); 2723 action = ps->ps_sigact[_SIG_IDX(sig)]; 2724 #ifdef KTRACE 2725 if (KTRPOINT(td, KTR_PSIG)) 2726 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2727 &td->td_oldsigmask : &td->td_sigmask, 0); 2728 #endif 2729 if (p->p_stops & S_SIG) { 2730 mtx_unlock(&ps->ps_mtx); 2731 stopevent(p, S_SIG, sig); 2732 mtx_lock(&ps->ps_mtx); 2733 } 2734 2735 if (action == SIG_DFL) { 2736 /* 2737 * Default action, where the default is to kill 2738 * the process. (Other cases were ignored above.) 2739 */ 2740 mtx_unlock(&ps->ps_mtx); 2741 sigexit(td, sig); 2742 /* NOTREACHED */ 2743 } else { 2744 /* 2745 * If we get here, the signal must be caught. 2746 */ 2747 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2748 ("postsig action")); 2749 /* 2750 * Set the new mask value and also defer further 2751 * occurrences of this signal. 2752 * 2753 * Special case: user has done a sigsuspend. Here the 2754 * current mask is not of interest, but rather the 2755 * mask from before the sigsuspend is what we want 2756 * restored after the signal processing is completed. 2757 */ 2758 if (td->td_pflags & TDP_OLDMASK) { 2759 returnmask = td->td_oldsigmask; 2760 td->td_pflags &= ~TDP_OLDMASK; 2761 } else 2762 returnmask = td->td_sigmask; 2763 2764 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2765 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2766 SIGADDSET(mask, sig); 2767 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2768 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2769 2770 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2771 /* 2772 * See kern_sigaction() for origin of this code. 2773 */ 2774 SIGDELSET(ps->ps_sigcatch, sig); 2775 if (sig != SIGCONT && 2776 sigprop(sig) & SA_IGNORE) 2777 SIGADDSET(ps->ps_sigignore, sig); 2778 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2779 } 2780 td->td_ru.ru_nsignals++; 2781 if (p->p_sig == sig) { 2782 p->p_code = 0; 2783 p->p_sig = 0; 2784 } 2785 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2786 } 2787 return (1); 2788 } 2789 2790 /* 2791 * Kill the current process for stated reason. 2792 */ 2793 void 2794 killproc(p, why) 2795 struct proc *p; 2796 char *why; 2797 { 2798 2799 PROC_LOCK_ASSERT(p, MA_OWNED); 2800 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2801 p, p->p_pid, p->p_comm); 2802 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2803 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2804 p->p_flag |= P_WKILLED; 2805 psignal(p, SIGKILL); 2806 } 2807 2808 /* 2809 * Force the current process to exit with the specified signal, dumping core 2810 * if appropriate. We bypass the normal tests for masked and caught signals, 2811 * allowing unrecoverable failures to terminate the process without changing 2812 * signal state. Mark the accounting record with the signal termination. 2813 * If dumping core, save the signal number for the debugger. Calls exit and 2814 * does not return. 2815 */ 2816 void 2817 sigexit(td, sig) 2818 struct thread *td; 2819 int sig; 2820 { 2821 struct proc *p = td->td_proc; 2822 2823 PROC_LOCK_ASSERT(p, MA_OWNED); 2824 p->p_acflag |= AXSIG; 2825 /* 2826 * We must be single-threading to generate a core dump. This 2827 * ensures that the registers in the core file are up-to-date. 2828 * Also, the ELF dump handler assumes that the thread list doesn't 2829 * change out from under it. 2830 * 2831 * XXX If another thread attempts to single-thread before us 2832 * (e.g. via fork()), we won't get a dump at all. 2833 */ 2834 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2835 p->p_sig = sig; 2836 /* 2837 * Log signals which would cause core dumps 2838 * (Log as LOG_INFO to appease those who don't want 2839 * these messages.) 2840 * XXX : Todo, as well as euid, write out ruid too 2841 * Note that coredump() drops proc lock. 2842 */ 2843 if (coredump(td) == 0) 2844 sig |= WCOREFLAG; 2845 if (kern_logsigexit) 2846 log(LOG_INFO, 2847 "pid %d (%s), uid %d: exited on signal %d%s\n", 2848 p->p_pid, p->p_comm, 2849 td->td_ucred ? td->td_ucred->cr_uid : -1, 2850 sig &~ WCOREFLAG, 2851 sig & WCOREFLAG ? " (core dumped)" : ""); 2852 } else 2853 PROC_UNLOCK(p); 2854 exit1(td, W_EXITCODE(0, sig)); 2855 /* NOTREACHED */ 2856 } 2857 2858 /* 2859 * Send queued SIGCHLD to parent when child process's state 2860 * is changed. 2861 */ 2862 static void 2863 sigparent(struct proc *p, int reason, int status) 2864 { 2865 PROC_LOCK_ASSERT(p, MA_OWNED); 2866 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2867 2868 if (p->p_ksi != NULL) { 2869 p->p_ksi->ksi_signo = SIGCHLD; 2870 p->p_ksi->ksi_code = reason; 2871 p->p_ksi->ksi_status = status; 2872 p->p_ksi->ksi_pid = p->p_pid; 2873 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2874 if (KSI_ONQ(p->p_ksi)) 2875 return; 2876 } 2877 tdsignal(p->p_pptr, NULL, SIGCHLD, p->p_ksi); 2878 } 2879 2880 static void 2881 childproc_jobstate(struct proc *p, int reason, int status) 2882 { 2883 struct sigacts *ps; 2884 2885 PROC_LOCK_ASSERT(p, MA_OWNED); 2886 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2887 2888 /* 2889 * Wake up parent sleeping in kern_wait(), also send 2890 * SIGCHLD to parent, but SIGCHLD does not guarantee 2891 * that parent will awake, because parent may masked 2892 * the signal. 2893 */ 2894 p->p_pptr->p_flag |= P_STATCHILD; 2895 wakeup(p->p_pptr); 2896 2897 ps = p->p_pptr->p_sigacts; 2898 mtx_lock(&ps->ps_mtx); 2899 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2900 mtx_unlock(&ps->ps_mtx); 2901 sigparent(p, reason, status); 2902 } else 2903 mtx_unlock(&ps->ps_mtx); 2904 } 2905 2906 void 2907 childproc_stopped(struct proc *p, int reason) 2908 { 2909 childproc_jobstate(p, reason, p->p_xstat); 2910 } 2911 2912 void 2913 childproc_continued(struct proc *p) 2914 { 2915 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 2916 } 2917 2918 void 2919 childproc_exited(struct proc *p) 2920 { 2921 int reason; 2922 int status = p->p_xstat; /* convert to int */ 2923 2924 reason = CLD_EXITED; 2925 if (WCOREDUMP(status)) 2926 reason = CLD_DUMPED; 2927 else if (WIFSIGNALED(status)) 2928 reason = CLD_KILLED; 2929 /* 2930 * XXX avoid calling wakeup(p->p_pptr), the work is 2931 * done in exit1(). 2932 */ 2933 sigparent(p, reason, status); 2934 } 2935 2936 static char corefilename[MAXPATHLEN] = {"%N.core"}; 2937 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2938 sizeof(corefilename), "process corefile name format string"); 2939 2940 /* 2941 * expand_name(name, uid, pid) 2942 * Expand the name described in corefilename, using name, uid, and pid. 2943 * corefilename is a printf-like string, with three format specifiers: 2944 * %N name of process ("name") 2945 * %P process id (pid) 2946 * %U user id (uid) 2947 * For example, "%N.core" is the default; they can be disabled completely 2948 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2949 * This is controlled by the sysctl variable kern.corefile (see above). 2950 */ 2951 static char * 2952 expand_name(name, uid, pid) 2953 const char *name; 2954 uid_t uid; 2955 pid_t pid; 2956 { 2957 struct sbuf sb; 2958 const char *format; 2959 char *temp; 2960 size_t i; 2961 2962 format = corefilename; 2963 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 2964 if (temp == NULL) 2965 return (NULL); 2966 (void)sbuf_new(&sb, temp, MAXPATHLEN, SBUF_FIXEDLEN); 2967 for (i = 0; format[i]; i++) { 2968 switch (format[i]) { 2969 case '%': /* Format character */ 2970 i++; 2971 switch (format[i]) { 2972 case '%': 2973 sbuf_putc(&sb, '%'); 2974 break; 2975 case 'N': /* process name */ 2976 sbuf_printf(&sb, "%s", name); 2977 break; 2978 case 'P': /* process id */ 2979 sbuf_printf(&sb, "%u", pid); 2980 break; 2981 case 'U': /* user id */ 2982 sbuf_printf(&sb, "%u", uid); 2983 break; 2984 default: 2985 log(LOG_ERR, 2986 "Unknown format character %c in " 2987 "corename `%s'\n", format[i], format); 2988 } 2989 break; 2990 default: 2991 sbuf_putc(&sb, format[i]); 2992 } 2993 } 2994 if (sbuf_overflowed(&sb)) { 2995 sbuf_delete(&sb); 2996 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 2997 "long\n", (long)pid, name, (u_long)uid); 2998 free(temp, M_TEMP); 2999 return (NULL); 3000 } 3001 sbuf_finish(&sb); 3002 sbuf_delete(&sb); 3003 return (temp); 3004 } 3005 3006 /* 3007 * Dump a process' core. The main routine does some 3008 * policy checking, and creates the name of the coredump; 3009 * then it passes on a vnode and a size limit to the process-specific 3010 * coredump routine if there is one; if there _is not_ one, it returns 3011 * ENOSYS; otherwise it returns the error from the process-specific routine. 3012 */ 3013 3014 static int 3015 coredump(struct thread *td) 3016 { 3017 struct proc *p = td->td_proc; 3018 register struct vnode *vp; 3019 register struct ucred *cred = td->td_ucred; 3020 struct flock lf; 3021 struct nameidata nd; 3022 struct vattr vattr; 3023 int error, error1, flags, locked; 3024 struct mount *mp; 3025 char *name; /* name of corefile */ 3026 off_t limit; 3027 int vfslocked; 3028 3029 PROC_LOCK_ASSERT(p, MA_OWNED); 3030 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3031 _STOPEVENT(p, S_CORE, 0); 3032 3033 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); 3034 if (name == NULL) { 3035 PROC_UNLOCK(p); 3036 #ifdef AUDIT 3037 audit_proc_coredump(td, NULL, EINVAL); 3038 #endif 3039 return (EINVAL); 3040 } 3041 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 3042 PROC_UNLOCK(p); 3043 #ifdef AUDIT 3044 audit_proc_coredump(td, name, EFAULT); 3045 #endif 3046 free(name, M_TEMP); 3047 return (EFAULT); 3048 } 3049 3050 /* 3051 * Note that the bulk of limit checking is done after 3052 * the corefile is created. The exception is if the limit 3053 * for corefiles is 0, in which case we don't bother 3054 * creating the corefile at all. This layout means that 3055 * a corefile is truncated instead of not being created, 3056 * if it is larger than the limit. 3057 */ 3058 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3059 PROC_UNLOCK(p); 3060 if (limit == 0) { 3061 #ifdef AUDIT 3062 audit_proc_coredump(td, name, EFBIG); 3063 #endif 3064 free(name, M_TEMP); 3065 return (EFBIG); 3066 } 3067 3068 restart: 3069 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, name, td); 3070 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3071 error = vn_open_cred(&nd, &flags, S_IRUSR | S_IWUSR, VN_OPEN_NOAUDIT, 3072 cred, NULL); 3073 if (error) { 3074 #ifdef AUDIT 3075 audit_proc_coredump(td, name, error); 3076 #endif 3077 free(name, M_TEMP); 3078 return (error); 3079 } 3080 vfslocked = NDHASGIANT(&nd); 3081 NDFREE(&nd, NDF_ONLY_PNBUF); 3082 vp = nd.ni_vp; 3083 3084 /* Don't dump to non-regular files or files with links. */ 3085 if (vp->v_type != VREG || 3086 VOP_GETATTR(vp, &vattr, cred) || vattr.va_nlink != 1) { 3087 VOP_UNLOCK(vp, 0); 3088 error = EFAULT; 3089 goto close; 3090 } 3091 3092 VOP_UNLOCK(vp, 0); 3093 lf.l_whence = SEEK_SET; 3094 lf.l_start = 0; 3095 lf.l_len = 0; 3096 lf.l_type = F_WRLCK; 3097 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3098 3099 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3100 lf.l_type = F_UNLCK; 3101 if (locked) 3102 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3103 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3104 goto out; 3105 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3106 goto out; 3107 VFS_UNLOCK_GIANT(vfslocked); 3108 goto restart; 3109 } 3110 3111 VATTR_NULL(&vattr); 3112 vattr.va_size = 0; 3113 if (set_core_nodump_flag) 3114 vattr.va_flags = UF_NODUMP; 3115 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3116 VOP_SETATTR(vp, &vattr, cred); 3117 VOP_UNLOCK(vp, 0); 3118 vn_finished_write(mp); 3119 PROC_LOCK(p); 3120 p->p_acflag |= ACORE; 3121 PROC_UNLOCK(p); 3122 3123 error = p->p_sysent->sv_coredump ? 3124 p->p_sysent->sv_coredump(td, vp, limit) : 3125 ENOSYS; 3126 3127 if (locked) { 3128 lf.l_type = F_UNLCK; 3129 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3130 } 3131 close: 3132 error1 = vn_close(vp, FWRITE, cred, td); 3133 if (error == 0) 3134 error = error1; 3135 out: 3136 #ifdef AUDIT 3137 audit_proc_coredump(td, name, error); 3138 #endif 3139 free(name, M_TEMP); 3140 VFS_UNLOCK_GIANT(vfslocked); 3141 return (error); 3142 } 3143 3144 /* 3145 * Nonexistent system call-- signal process (may want to handle it). Flag 3146 * error in case process won't see signal immediately (blocked or ignored). 3147 */ 3148 #ifndef _SYS_SYSPROTO_H_ 3149 struct nosys_args { 3150 int dummy; 3151 }; 3152 #endif 3153 /* ARGSUSED */ 3154 int 3155 nosys(td, args) 3156 struct thread *td; 3157 struct nosys_args *args; 3158 { 3159 struct proc *p = td->td_proc; 3160 3161 PROC_LOCK(p); 3162 psignal(p, SIGSYS); 3163 PROC_UNLOCK(p); 3164 return (ENOSYS); 3165 } 3166 3167 /* 3168 * Send a SIGIO or SIGURG signal to a process or process group using stored 3169 * credentials rather than those of the current process. 3170 */ 3171 void 3172 pgsigio(sigiop, sig, checkctty) 3173 struct sigio **sigiop; 3174 int sig, checkctty; 3175 { 3176 ksiginfo_t ksi; 3177 struct sigio *sigio; 3178 3179 ksiginfo_init(&ksi); 3180 ksi.ksi_signo = sig; 3181 ksi.ksi_code = SI_KERNEL; 3182 3183 SIGIO_LOCK(); 3184 sigio = *sigiop; 3185 if (sigio == NULL) { 3186 SIGIO_UNLOCK(); 3187 return; 3188 } 3189 if (sigio->sio_pgid > 0) { 3190 PROC_LOCK(sigio->sio_proc); 3191 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3192 psignal(sigio->sio_proc, sig); 3193 PROC_UNLOCK(sigio->sio_proc); 3194 } else if (sigio->sio_pgid < 0) { 3195 struct proc *p; 3196 3197 PGRP_LOCK(sigio->sio_pgrp); 3198 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3199 PROC_LOCK(p); 3200 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3201 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3202 psignal(p, sig); 3203 PROC_UNLOCK(p); 3204 } 3205 PGRP_UNLOCK(sigio->sio_pgrp); 3206 } 3207 SIGIO_UNLOCK(); 3208 } 3209 3210 static int 3211 filt_sigattach(struct knote *kn) 3212 { 3213 struct proc *p = curproc; 3214 3215 kn->kn_ptr.p_proc = p; 3216 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3217 3218 knlist_add(&p->p_klist, kn, 0); 3219 3220 return (0); 3221 } 3222 3223 static void 3224 filt_sigdetach(struct knote *kn) 3225 { 3226 struct proc *p = kn->kn_ptr.p_proc; 3227 3228 knlist_remove(&p->p_klist, kn, 0); 3229 } 3230 3231 /* 3232 * signal knotes are shared with proc knotes, so we apply a mask to 3233 * the hint in order to differentiate them from process hints. This 3234 * could be avoided by using a signal-specific knote list, but probably 3235 * isn't worth the trouble. 3236 */ 3237 static int 3238 filt_signal(struct knote *kn, long hint) 3239 { 3240 3241 if (hint & NOTE_SIGNAL) { 3242 hint &= ~NOTE_SIGNAL; 3243 3244 if (kn->kn_id == hint) 3245 kn->kn_data++; 3246 } 3247 return (kn->kn_data != 0); 3248 } 3249 3250 struct sigacts * 3251 sigacts_alloc(void) 3252 { 3253 struct sigacts *ps; 3254 3255 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3256 ps->ps_refcnt = 1; 3257 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3258 return (ps); 3259 } 3260 3261 void 3262 sigacts_free(struct sigacts *ps) 3263 { 3264 3265 mtx_lock(&ps->ps_mtx); 3266 ps->ps_refcnt--; 3267 if (ps->ps_refcnt == 0) { 3268 mtx_destroy(&ps->ps_mtx); 3269 free(ps, M_SUBPROC); 3270 } else 3271 mtx_unlock(&ps->ps_mtx); 3272 } 3273 3274 struct sigacts * 3275 sigacts_hold(struct sigacts *ps) 3276 { 3277 mtx_lock(&ps->ps_mtx); 3278 ps->ps_refcnt++; 3279 mtx_unlock(&ps->ps_mtx); 3280 return (ps); 3281 } 3282 3283 void 3284 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3285 { 3286 3287 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3288 mtx_lock(&src->ps_mtx); 3289 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3290 mtx_unlock(&src->ps_mtx); 3291 } 3292 3293 int 3294 sigacts_shared(struct sigacts *ps) 3295 { 3296 int shared; 3297 3298 mtx_lock(&ps->ps_mtx); 3299 shared = ps->ps_refcnt > 1; 3300 mtx_unlock(&ps->ps_mtx); 3301 return (shared); 3302 }
Cache object: b0b449f9a2c09c9f321bc62b91de1371
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