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/8.3/sys/kern/kern_sig.c 229486 2012-01-04 14:21:30Z pluknet $"); 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, 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, 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, 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 == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1106 error = ERESTART; 1107 if (error == ERESTART) 1108 return (error); 1109 td->td_retval[0] = error; 1110 return (0); 1111 } 1112 1113 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1114 td->td_retval[0] = error; 1115 return (0); 1116 } 1117 1118 int 1119 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1120 { 1121 struct timespec ts; 1122 struct timespec *timeout; 1123 sigset_t set; 1124 ksiginfo_t ksi; 1125 int error; 1126 1127 if (uap->timeout) { 1128 error = copyin(uap->timeout, &ts, sizeof(ts)); 1129 if (error) 1130 return (error); 1131 1132 timeout = &ts; 1133 } else 1134 timeout = NULL; 1135 1136 error = copyin(uap->set, &set, sizeof(set)); 1137 if (error) 1138 return (error); 1139 1140 error = kern_sigtimedwait(td, set, &ksi, timeout); 1141 if (error) 1142 return (error); 1143 1144 if (uap->info) 1145 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1146 1147 if (error == 0) 1148 td->td_retval[0] = ksi.ksi_signo; 1149 return (error); 1150 } 1151 1152 int 1153 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1154 { 1155 ksiginfo_t ksi; 1156 sigset_t set; 1157 int error; 1158 1159 error = copyin(uap->set, &set, sizeof(set)); 1160 if (error) 1161 return (error); 1162 1163 error = kern_sigtimedwait(td, set, &ksi, NULL); 1164 if (error) 1165 return (error); 1166 1167 if (uap->info) 1168 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1169 1170 if (error == 0) 1171 td->td_retval[0] = ksi.ksi_signo; 1172 return (error); 1173 } 1174 1175 int 1176 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1177 struct timespec *timeout) 1178 { 1179 struct sigacts *ps; 1180 sigset_t savedmask; 1181 struct proc *p; 1182 int error, sig, hz, i, timevalid = 0; 1183 struct timespec rts, ets, ts; 1184 struct timeval tv; 1185 1186 p = td->td_proc; 1187 error = 0; 1188 sig = 0; 1189 ets.tv_sec = 0; 1190 ets.tv_nsec = 0; 1191 SIG_CANTMASK(waitset); 1192 1193 PROC_LOCK(p); 1194 ps = p->p_sigacts; 1195 savedmask = td->td_sigmask; 1196 if (timeout) { 1197 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1198 timevalid = 1; 1199 getnanouptime(&rts); 1200 ets = rts; 1201 timespecadd(&ets, timeout); 1202 } 1203 } 1204 1205 restart: 1206 for (i = 1; i <= _SIG_MAXSIG; ++i) { 1207 if (!SIGISMEMBER(waitset, i)) 1208 continue; 1209 if (!SIGISMEMBER(td->td_sigqueue.sq_signals, i)) { 1210 if (SIGISMEMBER(p->p_sigqueue.sq_signals, i)) { 1211 sigqueue_move(&p->p_sigqueue, 1212 &td->td_sigqueue, i); 1213 } else 1214 continue; 1215 } 1216 1217 SIGFILLSET(td->td_sigmask); 1218 SIG_CANTMASK(td->td_sigmask); 1219 SIGDELSET(td->td_sigmask, i); 1220 mtx_lock(&ps->ps_mtx); 1221 sig = cursig(td, SIG_STOP_ALLOWED); 1222 mtx_unlock(&ps->ps_mtx); 1223 if (sig) 1224 goto out; 1225 else { 1226 /* 1227 * Because cursig() may have stopped current thread, 1228 * after it is resumed, things may have already been 1229 * changed, it should rescan any pending signals. 1230 */ 1231 goto restart; 1232 } 1233 } 1234 1235 if (error) 1236 goto out; 1237 1238 /* 1239 * POSIX says this must be checked after looking for pending 1240 * signals. 1241 */ 1242 if (timeout) { 1243 if (!timevalid) { 1244 error = EINVAL; 1245 goto out; 1246 } 1247 getnanouptime(&rts); 1248 if (timespeccmp(&rts, &ets, >=)) { 1249 error = EAGAIN; 1250 goto out; 1251 } 1252 ts = ets; 1253 timespecsub(&ts, &rts); 1254 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1255 hz = tvtohz(&tv); 1256 } else 1257 hz = 0; 1258 1259 td->td_sigmask = savedmask; 1260 SIGSETNAND(td->td_sigmask, waitset); 1261 signotify(td); 1262 error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz); 1263 if (timeout) { 1264 if (error == ERESTART) { 1265 /* timeout can not be restarted. */ 1266 error = EINTR; 1267 } else if (error == EAGAIN) { 1268 /* will calculate timeout by ourself. */ 1269 error = 0; 1270 } 1271 } 1272 goto restart; 1273 1274 out: 1275 td->td_sigmask = savedmask; 1276 signotify(td); 1277 if (sig) { 1278 ksiginfo_init(ksi); 1279 sigqueue_get(&td->td_sigqueue, sig, ksi); 1280 ksi->ksi_signo = sig; 1281 1282 SDT_PROBE(proc, kernel, , signal_clear, sig, ksi, 0, 0, 0); 1283 1284 if (ksi->ksi_code == SI_TIMER) 1285 itimer_accept(p, ksi->ksi_timerid, ksi); 1286 error = 0; 1287 1288 #ifdef KTRACE 1289 if (KTRPOINT(td, KTR_PSIG)) { 1290 sig_t action; 1291 1292 mtx_lock(&ps->ps_mtx); 1293 action = ps->ps_sigact[_SIG_IDX(sig)]; 1294 mtx_unlock(&ps->ps_mtx); 1295 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1296 } 1297 #endif 1298 if (sig == SIGKILL) 1299 sigexit(td, sig); 1300 } 1301 PROC_UNLOCK(p); 1302 return (error); 1303 } 1304 1305 #ifndef _SYS_SYSPROTO_H_ 1306 struct sigpending_args { 1307 sigset_t *set; 1308 }; 1309 #endif 1310 int 1311 sigpending(td, uap) 1312 struct thread *td; 1313 struct sigpending_args *uap; 1314 { 1315 struct proc *p = td->td_proc; 1316 sigset_t pending; 1317 1318 PROC_LOCK(p); 1319 pending = p->p_sigqueue.sq_signals; 1320 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1321 PROC_UNLOCK(p); 1322 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1323 } 1324 1325 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1326 #ifndef _SYS_SYSPROTO_H_ 1327 struct osigpending_args { 1328 int dummy; 1329 }; 1330 #endif 1331 int 1332 osigpending(td, uap) 1333 struct thread *td; 1334 struct osigpending_args *uap; 1335 { 1336 struct proc *p = td->td_proc; 1337 sigset_t pending; 1338 1339 PROC_LOCK(p); 1340 pending = p->p_sigqueue.sq_signals; 1341 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1342 PROC_UNLOCK(p); 1343 SIG2OSIG(pending, td->td_retval[0]); 1344 return (0); 1345 } 1346 #endif /* COMPAT_43 */ 1347 1348 #if defined(COMPAT_43) 1349 /* 1350 * Generalized interface signal handler, 4.3-compatible. 1351 */ 1352 #ifndef _SYS_SYSPROTO_H_ 1353 struct osigvec_args { 1354 int signum; 1355 struct sigvec *nsv; 1356 struct sigvec *osv; 1357 }; 1358 #endif 1359 /* ARGSUSED */ 1360 int 1361 osigvec(td, uap) 1362 struct thread *td; 1363 register struct osigvec_args *uap; 1364 { 1365 struct sigvec vec; 1366 struct sigaction nsa, osa; 1367 register struct sigaction *nsap, *osap; 1368 int error; 1369 1370 if (uap->signum <= 0 || uap->signum >= ONSIG) 1371 return (EINVAL); 1372 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1373 osap = (uap->osv != NULL) ? &osa : NULL; 1374 if (nsap) { 1375 error = copyin(uap->nsv, &vec, sizeof(vec)); 1376 if (error) 1377 return (error); 1378 nsap->sa_handler = vec.sv_handler; 1379 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1380 nsap->sa_flags = vec.sv_flags; 1381 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1382 } 1383 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1384 if (osap && !error) { 1385 vec.sv_handler = osap->sa_handler; 1386 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1387 vec.sv_flags = osap->sa_flags; 1388 vec.sv_flags &= ~SA_NOCLDWAIT; 1389 vec.sv_flags ^= SA_RESTART; 1390 error = copyout(&vec, uap->osv, sizeof(vec)); 1391 } 1392 return (error); 1393 } 1394 1395 #ifndef _SYS_SYSPROTO_H_ 1396 struct osigblock_args { 1397 int mask; 1398 }; 1399 #endif 1400 int 1401 osigblock(td, uap) 1402 register struct thread *td; 1403 struct osigblock_args *uap; 1404 { 1405 sigset_t set, oset; 1406 1407 OSIG2SIG(uap->mask, set); 1408 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1409 SIG2OSIG(oset, td->td_retval[0]); 1410 return (0); 1411 } 1412 1413 #ifndef _SYS_SYSPROTO_H_ 1414 struct osigsetmask_args { 1415 int mask; 1416 }; 1417 #endif 1418 int 1419 osigsetmask(td, uap) 1420 struct thread *td; 1421 struct osigsetmask_args *uap; 1422 { 1423 sigset_t set, oset; 1424 1425 OSIG2SIG(uap->mask, set); 1426 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1427 SIG2OSIG(oset, td->td_retval[0]); 1428 return (0); 1429 } 1430 #endif /* COMPAT_43 */ 1431 1432 /* 1433 * Suspend calling thread until signal, providing mask to be set in the 1434 * meantime. 1435 */ 1436 #ifndef _SYS_SYSPROTO_H_ 1437 struct sigsuspend_args { 1438 const sigset_t *sigmask; 1439 }; 1440 #endif 1441 /* ARGSUSED */ 1442 int 1443 sigsuspend(td, uap) 1444 struct thread *td; 1445 struct sigsuspend_args *uap; 1446 { 1447 sigset_t mask; 1448 int error; 1449 1450 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1451 if (error) 1452 return (error); 1453 return (kern_sigsuspend(td, mask)); 1454 } 1455 1456 int 1457 kern_sigsuspend(struct thread *td, sigset_t mask) 1458 { 1459 struct proc *p = td->td_proc; 1460 int has_sig, sig; 1461 1462 /* 1463 * When returning from sigsuspend, we want 1464 * the old mask to be restored after the 1465 * signal handler has finished. Thus, we 1466 * save it here and mark the sigacts structure 1467 * to indicate this. 1468 */ 1469 PROC_LOCK(p); 1470 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1471 SIGPROCMASK_PROC_LOCKED); 1472 td->td_pflags |= TDP_OLDMASK; 1473 1474 /* 1475 * Process signals now. Otherwise, we can get spurious wakeup 1476 * due to signal entered process queue, but delivered to other 1477 * thread. But sigsuspend should return only on signal 1478 * delivery. 1479 */ 1480 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1481 for (has_sig = 0; !has_sig;) { 1482 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1483 0) == 0) 1484 /* void */; 1485 thread_suspend_check(0); 1486 mtx_lock(&p->p_sigacts->ps_mtx); 1487 while ((sig = cursig(td, SIG_STOP_ALLOWED)) != 0) 1488 has_sig += postsig(sig); 1489 mtx_unlock(&p->p_sigacts->ps_mtx); 1490 } 1491 PROC_UNLOCK(p); 1492 return (EJUSTRETURN); 1493 } 1494 1495 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1496 /* 1497 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1498 * convention: libc stub passes mask, not pointer, to save a copyin. 1499 */ 1500 #ifndef _SYS_SYSPROTO_H_ 1501 struct osigsuspend_args { 1502 osigset_t mask; 1503 }; 1504 #endif 1505 /* ARGSUSED */ 1506 int 1507 osigsuspend(td, uap) 1508 struct thread *td; 1509 struct osigsuspend_args *uap; 1510 { 1511 sigset_t mask; 1512 1513 OSIG2SIG(uap->mask, mask); 1514 return (kern_sigsuspend(td, mask)); 1515 } 1516 #endif /* COMPAT_43 */ 1517 1518 #if defined(COMPAT_43) 1519 #ifndef _SYS_SYSPROTO_H_ 1520 struct osigstack_args { 1521 struct sigstack *nss; 1522 struct sigstack *oss; 1523 }; 1524 #endif 1525 /* ARGSUSED */ 1526 int 1527 osigstack(td, uap) 1528 struct thread *td; 1529 register struct osigstack_args *uap; 1530 { 1531 struct sigstack nss, oss; 1532 int error = 0; 1533 1534 if (uap->nss != NULL) { 1535 error = copyin(uap->nss, &nss, sizeof(nss)); 1536 if (error) 1537 return (error); 1538 } 1539 oss.ss_sp = td->td_sigstk.ss_sp; 1540 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1541 if (uap->nss != NULL) { 1542 td->td_sigstk.ss_sp = nss.ss_sp; 1543 td->td_sigstk.ss_size = 0; 1544 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1545 td->td_pflags |= TDP_ALTSTACK; 1546 } 1547 if (uap->oss != NULL) 1548 error = copyout(&oss, uap->oss, sizeof(oss)); 1549 1550 return (error); 1551 } 1552 #endif /* COMPAT_43 */ 1553 1554 #ifndef _SYS_SYSPROTO_H_ 1555 struct sigaltstack_args { 1556 stack_t *ss; 1557 stack_t *oss; 1558 }; 1559 #endif 1560 /* ARGSUSED */ 1561 int 1562 sigaltstack(td, uap) 1563 struct thread *td; 1564 register struct sigaltstack_args *uap; 1565 { 1566 stack_t ss, oss; 1567 int error; 1568 1569 if (uap->ss != NULL) { 1570 error = copyin(uap->ss, &ss, sizeof(ss)); 1571 if (error) 1572 return (error); 1573 } 1574 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1575 (uap->oss != NULL) ? &oss : NULL); 1576 if (error) 1577 return (error); 1578 if (uap->oss != NULL) 1579 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1580 return (error); 1581 } 1582 1583 int 1584 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1585 { 1586 struct proc *p = td->td_proc; 1587 int oonstack; 1588 1589 oonstack = sigonstack(cpu_getstack(td)); 1590 1591 if (oss != NULL) { 1592 *oss = td->td_sigstk; 1593 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1594 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1595 } 1596 1597 if (ss != NULL) { 1598 if (oonstack) 1599 return (EPERM); 1600 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1601 return (EINVAL); 1602 if (!(ss->ss_flags & SS_DISABLE)) { 1603 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1604 return (ENOMEM); 1605 1606 td->td_sigstk = *ss; 1607 td->td_pflags |= TDP_ALTSTACK; 1608 } else { 1609 td->td_pflags &= ~TDP_ALTSTACK; 1610 } 1611 } 1612 return (0); 1613 } 1614 1615 /* 1616 * Common code for kill process group/broadcast kill. 1617 * cp is calling process. 1618 */ 1619 static int 1620 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1621 { 1622 struct proc *p; 1623 struct pgrp *pgrp; 1624 int nfound = 0; 1625 1626 if (all) { 1627 /* 1628 * broadcast 1629 */ 1630 sx_slock(&allproc_lock); 1631 FOREACH_PROC_IN_SYSTEM(p) { 1632 PROC_LOCK(p); 1633 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1634 p == td->td_proc || p->p_state == PRS_NEW) { 1635 PROC_UNLOCK(p); 1636 continue; 1637 } 1638 if (p_cansignal(td, p, sig) == 0) { 1639 nfound++; 1640 if (sig) 1641 pksignal(p, sig, ksi); 1642 } 1643 PROC_UNLOCK(p); 1644 } 1645 sx_sunlock(&allproc_lock); 1646 } else { 1647 sx_slock(&proctree_lock); 1648 if (pgid == 0) { 1649 /* 1650 * zero pgid means send to my process group. 1651 */ 1652 pgrp = td->td_proc->p_pgrp; 1653 PGRP_LOCK(pgrp); 1654 } else { 1655 pgrp = pgfind(pgid); 1656 if (pgrp == NULL) { 1657 sx_sunlock(&proctree_lock); 1658 return (ESRCH); 1659 } 1660 } 1661 sx_sunlock(&proctree_lock); 1662 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1663 PROC_LOCK(p); 1664 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1665 p->p_state == PRS_NEW ) { 1666 PROC_UNLOCK(p); 1667 continue; 1668 } 1669 if (p_cansignal(td, p, sig) == 0) { 1670 nfound++; 1671 if (sig) 1672 pksignal(p, sig, ksi); 1673 } 1674 PROC_UNLOCK(p); 1675 } 1676 PGRP_UNLOCK(pgrp); 1677 } 1678 return (nfound ? 0 : ESRCH); 1679 } 1680 1681 #ifndef _SYS_SYSPROTO_H_ 1682 struct kill_args { 1683 int pid; 1684 int signum; 1685 }; 1686 #endif 1687 /* ARGSUSED */ 1688 int 1689 kill(struct thread *td, struct kill_args *uap) 1690 { 1691 ksiginfo_t ksi; 1692 struct proc *p; 1693 int error; 1694 1695 AUDIT_ARG_SIGNUM(uap->signum); 1696 AUDIT_ARG_PID(uap->pid); 1697 if ((u_int)uap->signum > _SIG_MAXSIG) 1698 return (EINVAL); 1699 1700 ksiginfo_init(&ksi); 1701 ksi.ksi_signo = uap->signum; 1702 ksi.ksi_code = SI_USER; 1703 ksi.ksi_pid = td->td_proc->p_pid; 1704 ksi.ksi_uid = td->td_ucred->cr_ruid; 1705 1706 if (uap->pid > 0) { 1707 /* kill single process */ 1708 if ((p = pfind(uap->pid)) == NULL) { 1709 if ((p = zpfind(uap->pid)) == NULL) 1710 return (ESRCH); 1711 } 1712 AUDIT_ARG_PROCESS(p); 1713 error = p_cansignal(td, p, uap->signum); 1714 if (error == 0 && uap->signum) 1715 pksignal(p, uap->signum, &ksi); 1716 PROC_UNLOCK(p); 1717 return (error); 1718 } 1719 switch (uap->pid) { 1720 case -1: /* broadcast signal */ 1721 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1722 case 0: /* signal own process group */ 1723 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1724 default: /* negative explicit process group */ 1725 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1726 } 1727 /* NOTREACHED */ 1728 } 1729 1730 #if defined(COMPAT_43) 1731 #ifndef _SYS_SYSPROTO_H_ 1732 struct okillpg_args { 1733 int pgid; 1734 int signum; 1735 }; 1736 #endif 1737 /* ARGSUSED */ 1738 int 1739 okillpg(struct thread *td, struct okillpg_args *uap) 1740 { 1741 ksiginfo_t ksi; 1742 1743 AUDIT_ARG_SIGNUM(uap->signum); 1744 AUDIT_ARG_PID(uap->pgid); 1745 if ((u_int)uap->signum > _SIG_MAXSIG) 1746 return (EINVAL); 1747 1748 ksiginfo_init(&ksi); 1749 ksi.ksi_signo = uap->signum; 1750 ksi.ksi_code = SI_USER; 1751 ksi.ksi_pid = td->td_proc->p_pid; 1752 ksi.ksi_uid = td->td_ucred->cr_ruid; 1753 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1754 } 1755 #endif /* COMPAT_43 */ 1756 1757 #ifndef _SYS_SYSPROTO_H_ 1758 struct sigqueue_args { 1759 pid_t pid; 1760 int signum; 1761 /* union sigval */ void *value; 1762 }; 1763 #endif 1764 int 1765 sigqueue(struct thread *td, struct sigqueue_args *uap) 1766 { 1767 ksiginfo_t ksi; 1768 struct proc *p; 1769 int error; 1770 1771 if ((u_int)uap->signum > _SIG_MAXSIG) 1772 return (EINVAL); 1773 1774 /* 1775 * Specification says sigqueue can only send signal to 1776 * single process. 1777 */ 1778 if (uap->pid <= 0) 1779 return (EINVAL); 1780 1781 if ((p = pfind(uap->pid)) == NULL) { 1782 if ((p = zpfind(uap->pid)) == NULL) 1783 return (ESRCH); 1784 } 1785 error = p_cansignal(td, p, uap->signum); 1786 if (error == 0 && uap->signum != 0) { 1787 ksiginfo_init(&ksi); 1788 ksi.ksi_flags = KSI_SIGQ; 1789 ksi.ksi_signo = uap->signum; 1790 ksi.ksi_code = SI_QUEUE; 1791 ksi.ksi_pid = td->td_proc->p_pid; 1792 ksi.ksi_uid = td->td_ucred->cr_ruid; 1793 ksi.ksi_value.sival_ptr = uap->value; 1794 error = tdsignal(p, NULL, ksi.ksi_signo, &ksi); 1795 } 1796 PROC_UNLOCK(p); 1797 return (error); 1798 } 1799 1800 /* 1801 * Send a signal to a process group. 1802 */ 1803 void 1804 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1805 { 1806 struct pgrp *pgrp; 1807 1808 if (pgid != 0) { 1809 sx_slock(&proctree_lock); 1810 pgrp = pgfind(pgid); 1811 sx_sunlock(&proctree_lock); 1812 if (pgrp != NULL) { 1813 pgsignal(pgrp, sig, 0, ksi); 1814 PGRP_UNLOCK(pgrp); 1815 } 1816 } 1817 } 1818 1819 /* 1820 * Send a signal to a process group. If checktty is 1, 1821 * limit to members which have a controlling terminal. 1822 */ 1823 void 1824 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1825 { 1826 struct proc *p; 1827 1828 if (pgrp) { 1829 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1830 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1831 PROC_LOCK(p); 1832 if (p->p_state == PRS_NORMAL && 1833 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1834 pksignal(p, sig, ksi); 1835 PROC_UNLOCK(p); 1836 } 1837 } 1838 } 1839 1840 /* 1841 * Send a signal caused by a trap to the current thread. If it will be 1842 * caught immediately, deliver it with correct code. Otherwise, post it 1843 * normally. 1844 */ 1845 void 1846 trapsignal(struct thread *td, ksiginfo_t *ksi) 1847 { 1848 struct sigacts *ps; 1849 sigset_t mask; 1850 struct proc *p; 1851 int sig; 1852 int code; 1853 1854 p = td->td_proc; 1855 sig = ksi->ksi_signo; 1856 code = ksi->ksi_code; 1857 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1858 1859 PROC_LOCK(p); 1860 ps = p->p_sigacts; 1861 mtx_lock(&ps->ps_mtx); 1862 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1863 !SIGISMEMBER(td->td_sigmask, sig)) { 1864 td->td_ru.ru_nsignals++; 1865 #ifdef KTRACE 1866 if (KTRPOINT(curthread, KTR_PSIG)) 1867 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1868 &td->td_sigmask, code); 1869 #endif 1870 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1871 ksi, &td->td_sigmask); 1872 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1873 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1874 SIGADDSET(mask, sig); 1875 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1876 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1877 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1878 /* 1879 * See kern_sigaction() for origin of this code. 1880 */ 1881 SIGDELSET(ps->ps_sigcatch, sig); 1882 if (sig != SIGCONT && 1883 sigprop(sig) & SA_IGNORE) 1884 SIGADDSET(ps->ps_sigignore, sig); 1885 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1886 } 1887 mtx_unlock(&ps->ps_mtx); 1888 } else { 1889 /* 1890 * Avoid a possible infinite loop if the thread 1891 * masking the signal or process is ignoring the 1892 * signal. 1893 */ 1894 if (kern_forcesigexit && 1895 (SIGISMEMBER(td->td_sigmask, sig) || 1896 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1897 SIGDELSET(td->td_sigmask, sig); 1898 SIGDELSET(ps->ps_sigcatch, sig); 1899 SIGDELSET(ps->ps_sigignore, sig); 1900 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1901 } 1902 mtx_unlock(&ps->ps_mtx); 1903 p->p_code = code; /* XXX for core dump/debugger */ 1904 p->p_sig = sig; /* XXX to verify code */ 1905 tdsignal(p, td, sig, ksi); 1906 } 1907 PROC_UNLOCK(p); 1908 } 1909 1910 static struct thread * 1911 sigtd(struct proc *p, int sig, int prop) 1912 { 1913 struct thread *td, *signal_td; 1914 1915 PROC_LOCK_ASSERT(p, MA_OWNED); 1916 1917 /* 1918 * Check if current thread can handle the signal without 1919 * switching context to another thread. 1920 */ 1921 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1922 return (curthread); 1923 signal_td = NULL; 1924 FOREACH_THREAD_IN_PROC(p, td) { 1925 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1926 signal_td = td; 1927 break; 1928 } 1929 } 1930 if (signal_td == NULL) 1931 signal_td = FIRST_THREAD_IN_PROC(p); 1932 return (signal_td); 1933 } 1934 1935 /* 1936 * Send the signal to the process. If the signal has an action, the action 1937 * is usually performed by the target process rather than the caller; we add 1938 * the signal to the set of pending signals for the process. 1939 * 1940 * Exceptions: 1941 * o When a stop signal is sent to a sleeping process that takes the 1942 * default action, the process is stopped without awakening it. 1943 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1944 * regardless of the signal action (eg, blocked or ignored). 1945 * 1946 * Other ignored signals are discarded immediately. 1947 * 1948 * NB: This function may be entered from the debugger via the "kill" DDB 1949 * command. There is little that can be done to mitigate the possibly messy 1950 * side effects of this unwise possibility. 1951 */ 1952 void 1953 psignal(struct proc *p, int sig) 1954 { 1955 ksiginfo_t ksi; 1956 1957 ksiginfo_init(&ksi); 1958 ksi.ksi_signo = sig; 1959 ksi.ksi_code = SI_KERNEL; 1960 (void) tdsignal(p, NULL, sig, &ksi); 1961 } 1962 1963 void 1964 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 1965 { 1966 1967 (void) tdsignal(p, NULL, sig, ksi); 1968 } 1969 1970 int 1971 psignal_event(struct proc *p, struct sigevent *sigev, ksiginfo_t *ksi) 1972 { 1973 struct thread *td = NULL; 1974 1975 PROC_LOCK_ASSERT(p, MA_OWNED); 1976 1977 KASSERT(!KSI_ONQ(ksi), ("psignal_event: ksi on queue")); 1978 1979 /* 1980 * ksi_code and other fields should be set before 1981 * calling this function. 1982 */ 1983 ksi->ksi_signo = sigev->sigev_signo; 1984 ksi->ksi_value = sigev->sigev_value; 1985 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 1986 td = thread_find(p, sigev->sigev_notify_thread_id); 1987 if (td == NULL) 1988 return (ESRCH); 1989 } 1990 return (tdsignal(p, td, ksi->ksi_signo, ksi)); 1991 } 1992 1993 void 1994 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 1995 { 1996 ksiginfo_t ksi_thunk; 1997 1998 /* 1999 * If ksi is NULL, use ksi_thunk and provide semantics 2000 * identical to tdsignal() in 9.0+. 2001 */ 2002 if (ksi == NULL) { 2003 ksi = &ksi_thunk; 2004 ksiginfo_init(ksi); 2005 ksi->ksi_signo = sig; 2006 ksi->ksi_code = SI_KERNEL; 2007 } 2008 (void) tdsignal(td->td_proc, td, sig, ksi); 2009 } 2010 2011 int 2012 tdsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2013 { 2014 sig_t action; 2015 sigqueue_t *sigqueue; 2016 int prop; 2017 struct sigacts *ps; 2018 int intrval; 2019 int ret = 0; 2020 int wakeup_swapper; 2021 2022 PROC_LOCK_ASSERT(p, MA_OWNED); 2023 2024 if (!_SIG_VALID(sig)) 2025 panic("tdsignal(): invalid signal %d", sig); 2026 2027 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("tdsignal: ksi on queue")); 2028 2029 /* 2030 * IEEE Std 1003.1-2001: return success when killing a zombie. 2031 */ 2032 if (p->p_state == PRS_ZOMBIE) { 2033 if (ksi && (ksi->ksi_flags & KSI_INS)) 2034 ksiginfo_tryfree(ksi); 2035 return (ret); 2036 } 2037 2038 ps = p->p_sigacts; 2039 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2040 prop = sigprop(sig); 2041 2042 if (td == NULL) { 2043 td = sigtd(p, sig, prop); 2044 sigqueue = &p->p_sigqueue; 2045 } else { 2046 KASSERT(td->td_proc == p, ("invalid thread")); 2047 sigqueue = &td->td_sigqueue; 2048 } 2049 2050 SDT_PROBE(proc, kernel, , signal_send, td, p, sig, 0, 0 ); 2051 2052 /* 2053 * If the signal is being ignored, 2054 * then we forget about it immediately. 2055 * (Note: we don't set SIGCONT in ps_sigignore, 2056 * and if it is set to SIG_IGN, 2057 * action will be SIG_DFL here.) 2058 */ 2059 mtx_lock(&ps->ps_mtx); 2060 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2061 SDT_PROBE(proc, kernel, , signal_discard, td, p, sig, 0, 0 ); 2062 2063 mtx_unlock(&ps->ps_mtx); 2064 if (ksi && (ksi->ksi_flags & KSI_INS)) 2065 ksiginfo_tryfree(ksi); 2066 return (ret); 2067 } 2068 if (SIGISMEMBER(td->td_sigmask, sig)) 2069 action = SIG_HOLD; 2070 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2071 action = SIG_CATCH; 2072 else 2073 action = SIG_DFL; 2074 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2075 intrval = EINTR; 2076 else 2077 intrval = ERESTART; 2078 mtx_unlock(&ps->ps_mtx); 2079 2080 if (prop & SA_CONT) 2081 sigqueue_delete_stopmask_proc(p); 2082 else if (prop & SA_STOP) { 2083 /* 2084 * If sending a tty stop signal to a member of an orphaned 2085 * process group, discard the signal here if the action 2086 * is default; don't stop the process below if sleeping, 2087 * and don't clear any pending SIGCONT. 2088 */ 2089 if ((prop & SA_TTYSTOP) && 2090 (p->p_pgrp->pg_jobc == 0) && 2091 (action == SIG_DFL)) { 2092 if (ksi && (ksi->ksi_flags & KSI_INS)) 2093 ksiginfo_tryfree(ksi); 2094 return (ret); 2095 } 2096 sigqueue_delete_proc(p, SIGCONT); 2097 if (p->p_flag & P_CONTINUED) { 2098 p->p_flag &= ~P_CONTINUED; 2099 PROC_LOCK(p->p_pptr); 2100 sigqueue_take(p->p_ksi); 2101 PROC_UNLOCK(p->p_pptr); 2102 } 2103 } 2104 2105 ret = sigqueue_add(sigqueue, sig, ksi); 2106 if (ret != 0) 2107 return (ret); 2108 signotify(td); 2109 /* 2110 * Defer further processing for signals which are held, 2111 * except that stopped processes must be continued by SIGCONT. 2112 */ 2113 if (action == SIG_HOLD && 2114 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2115 return (ret); 2116 /* 2117 * SIGKILL: Remove procfs STOPEVENTs. 2118 */ 2119 if (sig == SIGKILL) { 2120 /* from procfs_ioctl.c: PIOCBIC */ 2121 p->p_stops = 0; 2122 /* from procfs_ioctl.c: PIOCCONT */ 2123 p->p_step = 0; 2124 wakeup(&p->p_step); 2125 } 2126 /* 2127 * Some signals have a process-wide effect and a per-thread 2128 * component. Most processing occurs when the process next 2129 * tries to cross the user boundary, however there are some 2130 * times when processing needs to be done immediatly, such as 2131 * waking up threads so that they can cross the user boundary. 2132 * We try do the per-process part here. 2133 */ 2134 if (P_SHOULDSTOP(p)) { 2135 if (sig == SIGKILL) { 2136 /* 2137 * If traced process is already stopped, 2138 * then no further action is necessary. 2139 */ 2140 if (p->p_flag & P_TRACED) 2141 goto out; 2142 /* 2143 * SIGKILL sets process running. 2144 * It will die elsewhere. 2145 * All threads must be restarted. 2146 */ 2147 p->p_flag &= ~P_STOPPED_SIG; 2148 goto runfast; 2149 } 2150 2151 if (prop & SA_CONT) { 2152 /* 2153 * If traced process is already stopped, 2154 * then no further action is necessary. 2155 */ 2156 if (p->p_flag & P_TRACED) 2157 goto out; 2158 /* 2159 * If SIGCONT is default (or ignored), we continue the 2160 * process but don't leave the signal in sigqueue as 2161 * it has no further action. If SIGCONT is held, we 2162 * continue the process and leave the signal in 2163 * sigqueue. If the process catches SIGCONT, let it 2164 * handle the signal itself. If it isn't waiting on 2165 * an event, it goes back to run state. 2166 * Otherwise, process goes back to sleep state. 2167 */ 2168 p->p_flag &= ~P_STOPPED_SIG; 2169 PROC_SLOCK(p); 2170 if (p->p_numthreads == p->p_suspcount) { 2171 PROC_SUNLOCK(p); 2172 p->p_flag |= P_CONTINUED; 2173 p->p_xstat = SIGCONT; 2174 PROC_LOCK(p->p_pptr); 2175 childproc_continued(p); 2176 PROC_UNLOCK(p->p_pptr); 2177 PROC_SLOCK(p); 2178 } 2179 if (action == SIG_DFL) { 2180 thread_unsuspend(p); 2181 PROC_SUNLOCK(p); 2182 sigqueue_delete(sigqueue, sig); 2183 goto out; 2184 } 2185 if (action == SIG_CATCH) { 2186 /* 2187 * The process wants to catch it so it needs 2188 * to run at least one thread, but which one? 2189 */ 2190 PROC_SUNLOCK(p); 2191 goto runfast; 2192 } 2193 /* 2194 * The signal is not ignored or caught. 2195 */ 2196 thread_unsuspend(p); 2197 PROC_SUNLOCK(p); 2198 goto out; 2199 } 2200 2201 if (prop & SA_STOP) { 2202 /* 2203 * If traced process is already stopped, 2204 * then no further action is necessary. 2205 */ 2206 if (p->p_flag & P_TRACED) 2207 goto out; 2208 /* 2209 * Already stopped, don't need to stop again 2210 * (If we did the shell could get confused). 2211 * Just make sure the signal STOP bit set. 2212 */ 2213 p->p_flag |= P_STOPPED_SIG; 2214 sigqueue_delete(sigqueue, sig); 2215 goto out; 2216 } 2217 2218 /* 2219 * All other kinds of signals: 2220 * If a thread is sleeping interruptibly, simulate a 2221 * wakeup so that when it is continued it will be made 2222 * runnable and can look at the signal. However, don't make 2223 * the PROCESS runnable, leave it stopped. 2224 * It may run a bit until it hits a thread_suspend_check(). 2225 */ 2226 wakeup_swapper = 0; 2227 PROC_SLOCK(p); 2228 thread_lock(td); 2229 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2230 wakeup_swapper = sleepq_abort(td, intrval); 2231 thread_unlock(td); 2232 PROC_SUNLOCK(p); 2233 if (wakeup_swapper) 2234 kick_proc0(); 2235 goto out; 2236 /* 2237 * Mutexes are short lived. Threads waiting on them will 2238 * hit thread_suspend_check() soon. 2239 */ 2240 } else if (p->p_state == PRS_NORMAL) { 2241 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2242 tdsigwakeup(td, sig, action, intrval); 2243 goto out; 2244 } 2245 2246 MPASS(action == SIG_DFL); 2247 2248 if (prop & SA_STOP) { 2249 if (p->p_flag & P_PPWAIT) 2250 goto out; 2251 p->p_flag |= P_STOPPED_SIG; 2252 p->p_xstat = sig; 2253 PROC_SLOCK(p); 2254 sig_suspend_threads(td, p, 1); 2255 if (p->p_numthreads == p->p_suspcount) { 2256 /* 2257 * only thread sending signal to another 2258 * process can reach here, if thread is sending 2259 * signal to its process, because thread does 2260 * not suspend itself here, p_numthreads 2261 * should never be equal to p_suspcount. 2262 */ 2263 thread_stopped(p); 2264 PROC_SUNLOCK(p); 2265 sigqueue_delete_proc(p, p->p_xstat); 2266 } else 2267 PROC_SUNLOCK(p); 2268 goto out; 2269 } 2270 } else { 2271 /* Not in "NORMAL" state. discard the signal. */ 2272 sigqueue_delete(sigqueue, sig); 2273 goto out; 2274 } 2275 2276 /* 2277 * The process is not stopped so we need to apply the signal to all the 2278 * running threads. 2279 */ 2280 runfast: 2281 tdsigwakeup(td, sig, action, intrval); 2282 PROC_SLOCK(p); 2283 thread_unsuspend(p); 2284 PROC_SUNLOCK(p); 2285 out: 2286 /* If we jump here, proc slock should not be owned. */ 2287 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2288 return (ret); 2289 } 2290 2291 /* 2292 * The force of a signal has been directed against a single 2293 * thread. We need to see what we can do about knocking it 2294 * out of any sleep it may be in etc. 2295 */ 2296 static void 2297 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2298 { 2299 struct proc *p = td->td_proc; 2300 register int prop; 2301 int wakeup_swapper; 2302 2303 wakeup_swapper = 0; 2304 PROC_LOCK_ASSERT(p, MA_OWNED); 2305 prop = sigprop(sig); 2306 2307 PROC_SLOCK(p); 2308 thread_lock(td); 2309 /* 2310 * Bring the priority of a thread up if we want it to get 2311 * killed in this lifetime. 2312 */ 2313 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER) 2314 sched_prio(td, PUSER); 2315 if (TD_ON_SLEEPQ(td)) { 2316 /* 2317 * If thread is sleeping uninterruptibly 2318 * we can't interrupt the sleep... the signal will 2319 * be noticed when the process returns through 2320 * trap() or syscall(). 2321 */ 2322 if ((td->td_flags & TDF_SINTR) == 0) 2323 goto out; 2324 /* 2325 * If SIGCONT is default (or ignored) and process is 2326 * asleep, we are finished; the process should not 2327 * be awakened. 2328 */ 2329 if ((prop & SA_CONT) && action == SIG_DFL) { 2330 thread_unlock(td); 2331 PROC_SUNLOCK(p); 2332 sigqueue_delete(&p->p_sigqueue, sig); 2333 /* 2334 * It may be on either list in this state. 2335 * Remove from both for now. 2336 */ 2337 sigqueue_delete(&td->td_sigqueue, sig); 2338 return; 2339 } 2340 2341 /* 2342 * Give low priority threads a better chance to run. 2343 */ 2344 if (td->td_priority > PUSER) 2345 sched_prio(td, PUSER); 2346 2347 wakeup_swapper = sleepq_abort(td, intrval); 2348 } else { 2349 /* 2350 * Other states do nothing with the signal immediately, 2351 * other than kicking ourselves if we are running. 2352 * It will either never be noticed, or noticed very soon. 2353 */ 2354 #ifdef SMP 2355 if (TD_IS_RUNNING(td) && td != curthread) 2356 forward_signal(td); 2357 #endif 2358 } 2359 out: 2360 PROC_SUNLOCK(p); 2361 thread_unlock(td); 2362 if (wakeup_swapper) 2363 kick_proc0(); 2364 } 2365 2366 static void 2367 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2368 { 2369 struct thread *td2; 2370 int wakeup_swapper; 2371 2372 PROC_LOCK_ASSERT(p, MA_OWNED); 2373 PROC_SLOCK_ASSERT(p, MA_OWNED); 2374 2375 wakeup_swapper = 0; 2376 FOREACH_THREAD_IN_PROC(p, td2) { 2377 thread_lock(td2); 2378 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2379 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2380 (td2->td_flags & TDF_SINTR)) { 2381 if (td2->td_flags & TDF_SBDRY) { 2382 if (TD_IS_SUSPENDED(td2)) 2383 wakeup_swapper |= 2384 thread_unsuspend_one(td2); 2385 if (TD_ON_SLEEPQ(td2)) 2386 wakeup_swapper |= 2387 sleepq_abort(td2, ERESTART); 2388 } else if (!TD_IS_SUSPENDED(td2)) { 2389 thread_suspend_one(td2); 2390 } 2391 } else if (!TD_IS_SUSPENDED(td2)) { 2392 if (sending || td != td2) 2393 td2->td_flags |= TDF_ASTPENDING; 2394 #ifdef SMP 2395 if (TD_IS_RUNNING(td2) && td2 != td) 2396 forward_signal(td2); 2397 #endif 2398 } 2399 thread_unlock(td2); 2400 } 2401 if (wakeup_swapper) 2402 kick_proc0(); 2403 } 2404 2405 int 2406 ptracestop(struct thread *td, int sig) 2407 { 2408 struct proc *p = td->td_proc; 2409 2410 PROC_LOCK_ASSERT(p, MA_OWNED); 2411 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2412 &p->p_mtx.lock_object, "Stopping for traced signal"); 2413 2414 td->td_dbgflags |= TDB_XSIG; 2415 td->td_xsig = sig; 2416 PROC_SLOCK(p); 2417 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2418 if (p->p_flag & P_SINGLE_EXIT) { 2419 td->td_dbgflags &= ~TDB_XSIG; 2420 PROC_SUNLOCK(p); 2421 return (sig); 2422 } 2423 /* 2424 * Just make wait() to work, the last stopped thread 2425 * will win. 2426 */ 2427 p->p_xstat = sig; 2428 p->p_xthread = td; 2429 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2430 sig_suspend_threads(td, p, 0); 2431 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2432 td->td_dbgflags &= ~TDB_STOPATFORK; 2433 cv_broadcast(&p->p_dbgwait); 2434 } 2435 stopme: 2436 thread_suspend_switch(td); 2437 if (!(p->p_flag & P_TRACED)) { 2438 break; 2439 } 2440 if (td->td_dbgflags & TDB_SUSPEND) { 2441 if (p->p_flag & P_SINGLE_EXIT) 2442 break; 2443 goto stopme; 2444 } 2445 } 2446 PROC_SUNLOCK(p); 2447 return (td->td_xsig); 2448 } 2449 2450 static void 2451 reschedule_signals(struct proc *p, sigset_t block, int flags) 2452 { 2453 struct sigacts *ps; 2454 struct thread *td; 2455 int i; 2456 2457 PROC_LOCK_ASSERT(p, MA_OWNED); 2458 2459 ps = p->p_sigacts; 2460 for (i = 1; !SIGISEMPTY(block); i++) { 2461 if (!SIGISMEMBER(block, i)) 2462 continue; 2463 SIGDELSET(block, i); 2464 if (!SIGISMEMBER(p->p_siglist, i)) 2465 continue; 2466 2467 td = sigtd(p, i, 0); 2468 signotify(td); 2469 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2470 mtx_lock(&ps->ps_mtx); 2471 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, i)) 2472 tdsigwakeup(td, i, SIG_CATCH, 2473 (SIGISMEMBER(ps->ps_sigintr, i) ? EINTR : 2474 ERESTART)); 2475 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2476 mtx_unlock(&ps->ps_mtx); 2477 } 2478 } 2479 2480 void 2481 tdsigcleanup(struct thread *td) 2482 { 2483 struct proc *p; 2484 sigset_t unblocked; 2485 2486 p = td->td_proc; 2487 PROC_LOCK_ASSERT(p, MA_OWNED); 2488 2489 sigqueue_flush(&td->td_sigqueue); 2490 if (p->p_numthreads == 1) 2491 return; 2492 2493 /* 2494 * Since we cannot handle signals, notify signal post code 2495 * about this by filling the sigmask. 2496 * 2497 * Also, if needed, wake up thread(s) that do not block the 2498 * same signals as the exiting thread, since the thread might 2499 * have been selected for delivery and woken up. 2500 */ 2501 SIGFILLSET(unblocked); 2502 SIGSETNAND(unblocked, td->td_sigmask); 2503 SIGFILLSET(td->td_sigmask); 2504 reschedule_signals(p, unblocked, 0); 2505 2506 } 2507 2508 /* 2509 * If the current process has received a signal (should be caught or cause 2510 * termination, should interrupt current syscall), return the signal number. 2511 * Stop signals with default action are processed immediately, then cleared; 2512 * they aren't returned. This is checked after each entry to the system for 2513 * a syscall or trap (though this can usually be done without calling issignal 2514 * by checking the pending signal masks in cursig.) The normal call 2515 * sequence is 2516 * 2517 * while (sig = cursig(curthread)) 2518 * postsig(sig); 2519 */ 2520 static int 2521 issignal(struct thread *td, int stop_allowed) 2522 { 2523 struct proc *p; 2524 struct sigacts *ps; 2525 struct sigqueue *queue; 2526 sigset_t sigpending; 2527 int sig, prop, newsig; 2528 2529 p = td->td_proc; 2530 ps = p->p_sigacts; 2531 mtx_assert(&ps->ps_mtx, MA_OWNED); 2532 PROC_LOCK_ASSERT(p, MA_OWNED); 2533 for (;;) { 2534 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2535 2536 sigpending = td->td_sigqueue.sq_signals; 2537 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2538 SIGSETNAND(sigpending, td->td_sigmask); 2539 2540 if (p->p_flag & P_PPWAIT) 2541 SIG_STOPSIGMASK(sigpending); 2542 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2543 return (0); 2544 sig = sig_ffs(&sigpending); 2545 2546 if (p->p_stops & S_SIG) { 2547 mtx_unlock(&ps->ps_mtx); 2548 stopevent(p, S_SIG, sig); 2549 mtx_lock(&ps->ps_mtx); 2550 } 2551 2552 /* 2553 * We should see pending but ignored signals 2554 * only if P_TRACED was on when they were posted. 2555 */ 2556 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2557 sigqueue_delete(&td->td_sigqueue, sig); 2558 sigqueue_delete(&p->p_sigqueue, sig); 2559 continue; 2560 } 2561 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 2562 /* 2563 * If traced, always stop. 2564 * Remove old signal from queue before the stop. 2565 * XXX shrug off debugger, it causes siginfo to 2566 * be thrown away. 2567 */ 2568 queue = &td->td_sigqueue; 2569 td->td_dbgksi.ksi_signo = 0; 2570 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2571 queue = &p->p_sigqueue; 2572 sigqueue_get(queue, sig, &td->td_dbgksi); 2573 } 2574 2575 mtx_unlock(&ps->ps_mtx); 2576 newsig = ptracestop(td, sig); 2577 mtx_lock(&ps->ps_mtx); 2578 2579 if (sig != newsig) { 2580 2581 /* 2582 * If parent wants us to take the signal, 2583 * then it will leave it in p->p_xstat; 2584 * otherwise we just look for signals again. 2585 */ 2586 if (newsig == 0) 2587 continue; 2588 sig = newsig; 2589 2590 /* 2591 * Put the new signal into td_sigqueue. If the 2592 * signal is being masked, look for other signals. 2593 */ 2594 sigqueue_add(queue, sig, NULL); 2595 if (SIGISMEMBER(td->td_sigmask, sig)) 2596 continue; 2597 signotify(td); 2598 } else { 2599 if (td->td_dbgksi.ksi_signo != 0) { 2600 td->td_dbgksi.ksi_flags |= KSI_HEAD; 2601 if (sigqueue_add(&td->td_sigqueue, sig, 2602 &td->td_dbgksi) != 0) 2603 td->td_dbgksi.ksi_signo = 0; 2604 } 2605 if (td->td_dbgksi.ksi_signo == 0) 2606 sigqueue_add(&td->td_sigqueue, sig, 2607 NULL); 2608 } 2609 2610 /* 2611 * If the traced bit got turned off, go back up 2612 * to the top to rescan signals. This ensures 2613 * that p_sig* and p_sigact are consistent. 2614 */ 2615 if ((p->p_flag & P_TRACED) == 0) 2616 continue; 2617 } 2618 2619 prop = sigprop(sig); 2620 2621 /* 2622 * Decide whether the signal should be returned. 2623 * Return the signal's number, or fall through 2624 * to clear it from the pending mask. 2625 */ 2626 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2627 2628 case (intptr_t)SIG_DFL: 2629 /* 2630 * Don't take default actions on system processes. 2631 */ 2632 if (p->p_pid <= 1) { 2633 #ifdef DIAGNOSTIC 2634 /* 2635 * Are you sure you want to ignore SIGSEGV 2636 * in init? XXX 2637 */ 2638 printf("Process (pid %lu) got signal %d\n", 2639 (u_long)p->p_pid, sig); 2640 #endif 2641 break; /* == ignore */ 2642 } 2643 /* 2644 * If there is a pending stop signal to process 2645 * with default action, stop here, 2646 * then clear the signal. However, 2647 * if process is member of an orphaned 2648 * process group, ignore tty stop signals. 2649 */ 2650 if (prop & SA_STOP) { 2651 if (p->p_flag & P_TRACED || 2652 (p->p_pgrp->pg_jobc == 0 && 2653 prop & SA_TTYSTOP)) 2654 break; /* == ignore */ 2655 2656 /* Ignore, but do not drop the stop signal. */ 2657 if (stop_allowed != SIG_STOP_ALLOWED) 2658 return (sig); 2659 mtx_unlock(&ps->ps_mtx); 2660 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2661 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2662 p->p_flag |= P_STOPPED_SIG; 2663 p->p_xstat = sig; 2664 PROC_SLOCK(p); 2665 sig_suspend_threads(td, p, 0); 2666 thread_suspend_switch(td); 2667 PROC_SUNLOCK(p); 2668 mtx_lock(&ps->ps_mtx); 2669 break; 2670 } else if (prop & SA_IGNORE) { 2671 /* 2672 * Except for SIGCONT, shouldn't get here. 2673 * Default action is to ignore; drop it. 2674 */ 2675 break; /* == ignore */ 2676 } else 2677 return (sig); 2678 /*NOTREACHED*/ 2679 2680 case (intptr_t)SIG_IGN: 2681 /* 2682 * Masking above should prevent us ever trying 2683 * to take action on an ignored signal other 2684 * than SIGCONT, unless process is traced. 2685 */ 2686 if ((prop & SA_CONT) == 0 && 2687 (p->p_flag & P_TRACED) == 0) 2688 printf("issignal\n"); 2689 break; /* == ignore */ 2690 2691 default: 2692 /* 2693 * This signal has an action, let 2694 * postsig() process it. 2695 */ 2696 return (sig); 2697 } 2698 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2699 sigqueue_delete(&p->p_sigqueue, sig); 2700 } 2701 /* NOTREACHED */ 2702 } 2703 2704 void 2705 thread_stopped(struct proc *p) 2706 { 2707 int n; 2708 2709 PROC_LOCK_ASSERT(p, MA_OWNED); 2710 PROC_SLOCK_ASSERT(p, MA_OWNED); 2711 n = p->p_suspcount; 2712 if (p == curproc) 2713 n++; 2714 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2715 PROC_SUNLOCK(p); 2716 p->p_flag &= ~P_WAITED; 2717 PROC_LOCK(p->p_pptr); 2718 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2719 CLD_TRAPPED : CLD_STOPPED); 2720 PROC_UNLOCK(p->p_pptr); 2721 PROC_SLOCK(p); 2722 } 2723 } 2724 2725 /* 2726 * Take the action for the specified signal 2727 * from the current set of pending signals. 2728 */ 2729 int 2730 postsig(sig) 2731 register int sig; 2732 { 2733 struct thread *td = curthread; 2734 register struct proc *p = td->td_proc; 2735 struct sigacts *ps; 2736 sig_t action; 2737 ksiginfo_t ksi; 2738 sigset_t returnmask, mask; 2739 2740 KASSERT(sig != 0, ("postsig")); 2741 2742 PROC_LOCK_ASSERT(p, MA_OWNED); 2743 ps = p->p_sigacts; 2744 mtx_assert(&ps->ps_mtx, MA_OWNED); 2745 ksiginfo_init(&ksi); 2746 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2747 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2748 return (0); 2749 ksi.ksi_signo = sig; 2750 if (ksi.ksi_code == SI_TIMER) 2751 itimer_accept(p, ksi.ksi_timerid, &ksi); 2752 action = ps->ps_sigact[_SIG_IDX(sig)]; 2753 #ifdef KTRACE 2754 if (KTRPOINT(td, KTR_PSIG)) 2755 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2756 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 2757 #endif 2758 if (p->p_stops & S_SIG) { 2759 mtx_unlock(&ps->ps_mtx); 2760 stopevent(p, S_SIG, sig); 2761 mtx_lock(&ps->ps_mtx); 2762 } 2763 2764 if (action == SIG_DFL) { 2765 /* 2766 * Default action, where the default is to kill 2767 * the process. (Other cases were ignored above.) 2768 */ 2769 mtx_unlock(&ps->ps_mtx); 2770 sigexit(td, sig); 2771 /* NOTREACHED */ 2772 } else { 2773 /* 2774 * If we get here, the signal must be caught. 2775 */ 2776 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2777 ("postsig action")); 2778 /* 2779 * Set the new mask value and also defer further 2780 * occurrences of this signal. 2781 * 2782 * Special case: user has done a sigsuspend. Here the 2783 * current mask is not of interest, but rather the 2784 * mask from before the sigsuspend is what we want 2785 * restored after the signal processing is completed. 2786 */ 2787 if (td->td_pflags & TDP_OLDMASK) { 2788 returnmask = td->td_oldsigmask; 2789 td->td_pflags &= ~TDP_OLDMASK; 2790 } else 2791 returnmask = td->td_sigmask; 2792 2793 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2794 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2795 SIGADDSET(mask, sig); 2796 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2797 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2798 2799 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2800 /* 2801 * See kern_sigaction() for origin of this code. 2802 */ 2803 SIGDELSET(ps->ps_sigcatch, sig); 2804 if (sig != SIGCONT && 2805 sigprop(sig) & SA_IGNORE) 2806 SIGADDSET(ps->ps_sigignore, sig); 2807 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2808 } 2809 td->td_ru.ru_nsignals++; 2810 if (p->p_sig == sig) { 2811 p->p_code = 0; 2812 p->p_sig = 0; 2813 } 2814 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2815 } 2816 return (1); 2817 } 2818 2819 /* 2820 * Kill the current process for stated reason. 2821 */ 2822 void 2823 killproc(p, why) 2824 struct proc *p; 2825 char *why; 2826 { 2827 2828 PROC_LOCK_ASSERT(p, MA_OWNED); 2829 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2830 p, p->p_pid, p->p_comm); 2831 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2832 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2833 p->p_flag |= P_WKILLED; 2834 psignal(p, SIGKILL); 2835 } 2836 2837 /* 2838 * Force the current process to exit with the specified signal, dumping core 2839 * if appropriate. We bypass the normal tests for masked and caught signals, 2840 * allowing unrecoverable failures to terminate the process without changing 2841 * signal state. Mark the accounting record with the signal termination. 2842 * If dumping core, save the signal number for the debugger. Calls exit and 2843 * does not return. 2844 */ 2845 void 2846 sigexit(td, sig) 2847 struct thread *td; 2848 int sig; 2849 { 2850 struct proc *p = td->td_proc; 2851 2852 PROC_LOCK_ASSERT(p, MA_OWNED); 2853 p->p_acflag |= AXSIG; 2854 /* 2855 * We must be single-threading to generate a core dump. This 2856 * ensures that the registers in the core file are up-to-date. 2857 * Also, the ELF dump handler assumes that the thread list doesn't 2858 * change out from under it. 2859 * 2860 * XXX If another thread attempts to single-thread before us 2861 * (e.g. via fork()), we won't get a dump at all. 2862 */ 2863 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2864 p->p_sig = sig; 2865 /* 2866 * Log signals which would cause core dumps 2867 * (Log as LOG_INFO to appease those who don't want 2868 * these messages.) 2869 * XXX : Todo, as well as euid, write out ruid too 2870 * Note that coredump() drops proc lock. 2871 */ 2872 if (coredump(td) == 0) 2873 sig |= WCOREFLAG; 2874 if (kern_logsigexit) 2875 log(LOG_INFO, 2876 "pid %d (%s), uid %d: exited on signal %d%s\n", 2877 p->p_pid, p->p_comm, 2878 td->td_ucred ? td->td_ucred->cr_uid : -1, 2879 sig &~ WCOREFLAG, 2880 sig & WCOREFLAG ? " (core dumped)" : ""); 2881 } else 2882 PROC_UNLOCK(p); 2883 exit1(td, W_EXITCODE(0, sig)); 2884 /* NOTREACHED */ 2885 } 2886 2887 /* 2888 * Send queued SIGCHLD to parent when child process's state 2889 * is changed. 2890 */ 2891 static void 2892 sigparent(struct proc *p, int reason, int status) 2893 { 2894 PROC_LOCK_ASSERT(p, MA_OWNED); 2895 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2896 2897 if (p->p_ksi != NULL) { 2898 p->p_ksi->ksi_signo = SIGCHLD; 2899 p->p_ksi->ksi_code = reason; 2900 p->p_ksi->ksi_status = status; 2901 p->p_ksi->ksi_pid = p->p_pid; 2902 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2903 if (KSI_ONQ(p->p_ksi)) 2904 return; 2905 } 2906 tdsignal(p->p_pptr, NULL, SIGCHLD, p->p_ksi); 2907 } 2908 2909 static void 2910 childproc_jobstate(struct proc *p, int reason, int status) 2911 { 2912 struct sigacts *ps; 2913 2914 PROC_LOCK_ASSERT(p, MA_OWNED); 2915 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2916 2917 /* 2918 * Wake up parent sleeping in kern_wait(), also send 2919 * SIGCHLD to parent, but SIGCHLD does not guarantee 2920 * that parent will awake, because parent may masked 2921 * the signal. 2922 */ 2923 p->p_pptr->p_flag |= P_STATCHILD; 2924 wakeup(p->p_pptr); 2925 2926 ps = p->p_pptr->p_sigacts; 2927 mtx_lock(&ps->ps_mtx); 2928 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2929 mtx_unlock(&ps->ps_mtx); 2930 sigparent(p, reason, status); 2931 } else 2932 mtx_unlock(&ps->ps_mtx); 2933 } 2934 2935 void 2936 childproc_stopped(struct proc *p, int reason) 2937 { 2938 childproc_jobstate(p, reason, p->p_xstat); 2939 } 2940 2941 void 2942 childproc_continued(struct proc *p) 2943 { 2944 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 2945 } 2946 2947 void 2948 childproc_exited(struct proc *p) 2949 { 2950 int reason; 2951 int status = p->p_xstat; /* convert to int */ 2952 2953 reason = CLD_EXITED; 2954 if (WCOREDUMP(status)) 2955 reason = CLD_DUMPED; 2956 else if (WIFSIGNALED(status)) 2957 reason = CLD_KILLED; 2958 /* 2959 * XXX avoid calling wakeup(p->p_pptr), the work is 2960 * done in exit1(). 2961 */ 2962 sigparent(p, reason, status); 2963 } 2964 2965 static char corefilename[MAXPATHLEN] = {"%N.core"}; 2966 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2967 sizeof(corefilename), "process corefile name format string"); 2968 2969 /* 2970 * expand_name(name, uid, pid) 2971 * Expand the name described in corefilename, using name, uid, and pid. 2972 * corefilename is a printf-like string, with three format specifiers: 2973 * %N name of process ("name") 2974 * %P process id (pid) 2975 * %U user id (uid) 2976 * For example, "%N.core" is the default; they can be disabled completely 2977 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2978 * This is controlled by the sysctl variable kern.corefile (see above). 2979 */ 2980 static char * 2981 expand_name(name, uid, pid) 2982 const char *name; 2983 uid_t uid; 2984 pid_t pid; 2985 { 2986 struct sbuf sb; 2987 const char *format; 2988 char *temp; 2989 size_t i; 2990 2991 format = corefilename; 2992 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 2993 if (temp == NULL) 2994 return (NULL); 2995 (void)sbuf_new(&sb, temp, MAXPATHLEN, SBUF_FIXEDLEN); 2996 for (i = 0; format[i]; i++) { 2997 switch (format[i]) { 2998 case '%': /* Format character */ 2999 i++; 3000 switch (format[i]) { 3001 case '%': 3002 sbuf_putc(&sb, '%'); 3003 break; 3004 case 'N': /* process name */ 3005 sbuf_printf(&sb, "%s", name); 3006 break; 3007 case 'P': /* process id */ 3008 sbuf_printf(&sb, "%u", pid); 3009 break; 3010 case 'U': /* user id */ 3011 sbuf_printf(&sb, "%u", uid); 3012 break; 3013 default: 3014 log(LOG_ERR, 3015 "Unknown format character %c in " 3016 "corename `%s'\n", format[i], format); 3017 } 3018 break; 3019 default: 3020 sbuf_putc(&sb, format[i]); 3021 } 3022 } 3023 if (sbuf_overflowed(&sb)) { 3024 sbuf_delete(&sb); 3025 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3026 "long\n", (long)pid, name, (u_long)uid); 3027 free(temp, M_TEMP); 3028 return (NULL); 3029 } 3030 sbuf_finish(&sb); 3031 sbuf_delete(&sb); 3032 return (temp); 3033 } 3034 3035 /* 3036 * Dump a process' core. The main routine does some 3037 * policy checking, and creates the name of the coredump; 3038 * then it passes on a vnode and a size limit to the process-specific 3039 * coredump routine if there is one; if there _is not_ one, it returns 3040 * ENOSYS; otherwise it returns the error from the process-specific routine. 3041 */ 3042 3043 static int 3044 coredump(struct thread *td) 3045 { 3046 struct proc *p = td->td_proc; 3047 register struct vnode *vp; 3048 register struct ucred *cred = td->td_ucred; 3049 struct flock lf; 3050 struct nameidata nd; 3051 struct vattr vattr; 3052 int error, error1, flags, locked; 3053 struct mount *mp; 3054 char *name; /* name of corefile */ 3055 off_t limit; 3056 int vfslocked; 3057 3058 PROC_LOCK_ASSERT(p, MA_OWNED); 3059 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3060 _STOPEVENT(p, S_CORE, 0); 3061 3062 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); 3063 if (name == NULL) { 3064 PROC_UNLOCK(p); 3065 #ifdef AUDIT 3066 audit_proc_coredump(td, NULL, EINVAL); 3067 #endif 3068 return (EINVAL); 3069 } 3070 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 3071 PROC_UNLOCK(p); 3072 #ifdef AUDIT 3073 audit_proc_coredump(td, name, EFAULT); 3074 #endif 3075 free(name, M_TEMP); 3076 return (EFAULT); 3077 } 3078 3079 /* 3080 * Note that the bulk of limit checking is done after 3081 * the corefile is created. The exception is if the limit 3082 * for corefiles is 0, in which case we don't bother 3083 * creating the corefile at all. This layout means that 3084 * a corefile is truncated instead of not being created, 3085 * if it is larger than the limit. 3086 */ 3087 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3088 PROC_UNLOCK(p); 3089 if (limit == 0) { 3090 #ifdef AUDIT 3091 audit_proc_coredump(td, name, EFBIG); 3092 #endif 3093 free(name, M_TEMP); 3094 return (EFBIG); 3095 } 3096 3097 restart: 3098 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, name, td); 3099 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3100 error = vn_open_cred(&nd, &flags, S_IRUSR | S_IWUSR, VN_OPEN_NOAUDIT, 3101 cred, NULL); 3102 if (error) { 3103 #ifdef AUDIT 3104 audit_proc_coredump(td, name, error); 3105 #endif 3106 free(name, M_TEMP); 3107 return (error); 3108 } 3109 vfslocked = NDHASGIANT(&nd); 3110 NDFREE(&nd, NDF_ONLY_PNBUF); 3111 vp = nd.ni_vp; 3112 3113 /* Don't dump to non-regular files or files with links. */ 3114 if (vp->v_type != VREG || 3115 VOP_GETATTR(vp, &vattr, cred) || vattr.va_nlink != 1) { 3116 VOP_UNLOCK(vp, 0); 3117 error = EFAULT; 3118 goto close; 3119 } 3120 3121 VOP_UNLOCK(vp, 0); 3122 lf.l_whence = SEEK_SET; 3123 lf.l_start = 0; 3124 lf.l_len = 0; 3125 lf.l_type = F_WRLCK; 3126 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3127 3128 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3129 lf.l_type = F_UNLCK; 3130 if (locked) 3131 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3132 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3133 goto out; 3134 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3135 goto out; 3136 VFS_UNLOCK_GIANT(vfslocked); 3137 goto restart; 3138 } 3139 3140 VATTR_NULL(&vattr); 3141 vattr.va_size = 0; 3142 if (set_core_nodump_flag) 3143 vattr.va_flags = UF_NODUMP; 3144 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3145 VOP_SETATTR(vp, &vattr, cred); 3146 VOP_UNLOCK(vp, 0); 3147 vn_finished_write(mp); 3148 PROC_LOCK(p); 3149 p->p_acflag |= ACORE; 3150 PROC_UNLOCK(p); 3151 3152 error = p->p_sysent->sv_coredump ? 3153 p->p_sysent->sv_coredump(td, vp, limit) : 3154 ENOSYS; 3155 3156 if (locked) { 3157 lf.l_type = F_UNLCK; 3158 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3159 } 3160 close: 3161 error1 = vn_close(vp, FWRITE, cred, td); 3162 if (error == 0) 3163 error = error1; 3164 out: 3165 #ifdef AUDIT 3166 audit_proc_coredump(td, name, error); 3167 #endif 3168 free(name, M_TEMP); 3169 VFS_UNLOCK_GIANT(vfslocked); 3170 return (error); 3171 } 3172 3173 /* 3174 * Nonexistent system call-- signal process (may want to handle it). Flag 3175 * error in case process won't see signal immediately (blocked or ignored). 3176 */ 3177 #ifndef _SYS_SYSPROTO_H_ 3178 struct nosys_args { 3179 int dummy; 3180 }; 3181 #endif 3182 /* ARGSUSED */ 3183 int 3184 nosys(td, args) 3185 struct thread *td; 3186 struct nosys_args *args; 3187 { 3188 struct proc *p = td->td_proc; 3189 3190 PROC_LOCK(p); 3191 psignal(p, SIGSYS); 3192 PROC_UNLOCK(p); 3193 return (ENOSYS); 3194 } 3195 3196 /* 3197 * Send a SIGIO or SIGURG signal to a process or process group using stored 3198 * credentials rather than those of the current process. 3199 */ 3200 void 3201 pgsigio(sigiop, sig, checkctty) 3202 struct sigio **sigiop; 3203 int sig, checkctty; 3204 { 3205 ksiginfo_t ksi; 3206 struct sigio *sigio; 3207 3208 ksiginfo_init(&ksi); 3209 ksi.ksi_signo = sig; 3210 ksi.ksi_code = SI_KERNEL; 3211 3212 SIGIO_LOCK(); 3213 sigio = *sigiop; 3214 if (sigio == NULL) { 3215 SIGIO_UNLOCK(); 3216 return; 3217 } 3218 if (sigio->sio_pgid > 0) { 3219 PROC_LOCK(sigio->sio_proc); 3220 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3221 psignal(sigio->sio_proc, sig); 3222 PROC_UNLOCK(sigio->sio_proc); 3223 } else if (sigio->sio_pgid < 0) { 3224 struct proc *p; 3225 3226 PGRP_LOCK(sigio->sio_pgrp); 3227 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3228 PROC_LOCK(p); 3229 if (p->p_state == PRS_NORMAL && 3230 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3231 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3232 psignal(p, sig); 3233 PROC_UNLOCK(p); 3234 } 3235 PGRP_UNLOCK(sigio->sio_pgrp); 3236 } 3237 SIGIO_UNLOCK(); 3238 } 3239 3240 static int 3241 filt_sigattach(struct knote *kn) 3242 { 3243 struct proc *p = curproc; 3244 3245 kn->kn_ptr.p_proc = p; 3246 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3247 3248 knlist_add(&p->p_klist, kn, 0); 3249 3250 return (0); 3251 } 3252 3253 static void 3254 filt_sigdetach(struct knote *kn) 3255 { 3256 struct proc *p = kn->kn_ptr.p_proc; 3257 3258 knlist_remove(&p->p_klist, kn, 0); 3259 } 3260 3261 /* 3262 * signal knotes are shared with proc knotes, so we apply a mask to 3263 * the hint in order to differentiate them from process hints. This 3264 * could be avoided by using a signal-specific knote list, but probably 3265 * isn't worth the trouble. 3266 */ 3267 static int 3268 filt_signal(struct knote *kn, long hint) 3269 { 3270 3271 if (hint & NOTE_SIGNAL) { 3272 hint &= ~NOTE_SIGNAL; 3273 3274 if (kn->kn_id == hint) 3275 kn->kn_data++; 3276 } 3277 return (kn->kn_data != 0); 3278 } 3279 3280 struct sigacts * 3281 sigacts_alloc(void) 3282 { 3283 struct sigacts *ps; 3284 3285 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3286 ps->ps_refcnt = 1; 3287 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3288 return (ps); 3289 } 3290 3291 void 3292 sigacts_free(struct sigacts *ps) 3293 { 3294 3295 mtx_lock(&ps->ps_mtx); 3296 ps->ps_refcnt--; 3297 if (ps->ps_refcnt == 0) { 3298 mtx_destroy(&ps->ps_mtx); 3299 free(ps, M_SUBPROC); 3300 } else 3301 mtx_unlock(&ps->ps_mtx); 3302 } 3303 3304 struct sigacts * 3305 sigacts_hold(struct sigacts *ps) 3306 { 3307 mtx_lock(&ps->ps_mtx); 3308 ps->ps_refcnt++; 3309 mtx_unlock(&ps->ps_mtx); 3310 return (ps); 3311 } 3312 3313 void 3314 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3315 { 3316 3317 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3318 mtx_lock(&src->ps_mtx); 3319 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3320 mtx_unlock(&src->ps_mtx); 3321 } 3322 3323 int 3324 sigacts_shared(struct sigacts *ps) 3325 { 3326 int shared; 3327 3328 mtx_lock(&ps->ps_mtx); 3329 shared = ps->ps_refcnt > 1; 3330 mtx_unlock(&ps->ps_mtx); 3331 return (shared); 3332 }
Cache object: 5a820fdc88190484aea7a6a02bbd6fde
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