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