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 #include "opt_core.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/signalvar.h> 48 #include <sys/vnode.h> 49 #include <sys/acct.h> 50 #include <sys/condvar.h> 51 #include <sys/event.h> 52 #include <sys/fcntl.h> 53 #include <sys/imgact.h> 54 #include <sys/kernel.h> 55 #include <sys/ktr.h> 56 #include <sys/ktrace.h> 57 #include <sys/lock.h> 58 #include <sys/malloc.h> 59 #include <sys/mutex.h> 60 #include <sys/namei.h> 61 #include <sys/proc.h> 62 #include <sys/posix4.h> 63 #include <sys/pioctl.h> 64 #include <sys/resourcevar.h> 65 #include <sys/sdt.h> 66 #include <sys/sbuf.h> 67 #include <sys/sleepqueue.h> 68 #include <sys/smp.h> 69 #include <sys/stat.h> 70 #include <sys/sx.h> 71 #include <sys/syscallsubr.h> 72 #include <sys/sysctl.h> 73 #include <sys/sysent.h> 74 #include <sys/syslog.h> 75 #include <sys/sysproto.h> 76 #include <sys/timers.h> 77 #include <sys/unistd.h> 78 #include <sys/wait.h> 79 #include <vm/vm.h> 80 #include <vm/vm_extern.h> 81 #include <vm/uma.h> 82 83 #include <sys/jail.h> 84 85 #include <machine/cpu.h> 86 87 #include <security/audit/audit.h> 88 89 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 90 91 SDT_PROVIDER_DECLARE(proc); 92 SDT_PROBE_DEFINE(proc, kernel, , signal_send); 93 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 0, "struct thread *"); 94 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 1, "struct proc *"); 95 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 2, "int"); 96 SDT_PROBE_DEFINE(proc, kernel, , signal_clear); 97 SDT_PROBE_ARGTYPE(proc, kernel, , signal_clear, 0, "int"); 98 SDT_PROBE_ARGTYPE(proc, kernel, , signal_clear, 1, "ksiginfo_t *"); 99 SDT_PROBE_DEFINE(proc, kernel, , signal_discard); 100 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 0, "struct thread *"); 101 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 1, "struct proc *"); 102 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 2, "int"); 103 104 static int coredump(struct thread *); 105 static char *expand_name(const char *, uid_t, pid_t, struct thread *, int); 106 static int killpg1(struct thread *td, int sig, int pgid, int all, 107 ksiginfo_t *ksi); 108 static int issignal(struct thread *td, int stop_allowed); 109 static int sigprop(int sig); 110 static int tdsendsignal(struct proc *p, struct thread *td, int sig, 111 ksiginfo_t *ksi); 112 static void tdsigwakeup(struct thread *, int, sig_t, int); 113 static void sig_suspend_threads(struct thread *, struct proc *, int); 114 static int filt_sigattach(struct knote *kn); 115 static void filt_sigdetach(struct knote *kn); 116 static int filt_signal(struct knote *kn, long hint); 117 static struct thread *sigtd(struct proc *p, int sig, int prop); 118 static void sigqueue_start(void); 119 120 static uma_zone_t ksiginfo_zone = NULL; 121 struct filterops sig_filtops = { 122 .f_isfd = 0, 123 .f_attach = filt_sigattach, 124 .f_detach = filt_sigdetach, 125 .f_event = filt_signal, 126 }; 127 128 static int kern_logsigexit = 1; 129 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 130 &kern_logsigexit, 0, 131 "Log processes quitting on abnormal signals to syslog(3)"); 132 133 static int kern_forcesigexit = 1; 134 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 135 &kern_forcesigexit, 0, "Force trap signal to be handled"); 136 137 SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, "POSIX real time signal"); 138 139 static int max_pending_per_proc = 128; 140 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 141 &max_pending_per_proc, 0, "Max pending signals per proc"); 142 143 static int preallocate_siginfo = 1024; 144 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo); 145 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD, 146 &preallocate_siginfo, 0, "Preallocated signal memory size"); 147 148 static int signal_overflow = 0; 149 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 150 &signal_overflow, 0, "Number of signals overflew"); 151 152 static int signal_alloc_fail = 0; 153 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 154 &signal_alloc_fail, 0, "signals failed to be allocated"); 155 156 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 157 158 /* 159 * Policy -- Can ucred cr1 send SIGIO to process cr2? 160 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 161 * in the right situations. 162 */ 163 #define CANSIGIO(cr1, cr2) \ 164 ((cr1)->cr_uid == 0 || \ 165 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 166 (cr1)->cr_uid == (cr2)->cr_ruid || \ 167 (cr1)->cr_ruid == (cr2)->cr_uid || \ 168 (cr1)->cr_uid == (cr2)->cr_uid) 169 170 static int sugid_coredump; 171 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 172 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 173 174 static int do_coredump = 1; 175 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 176 &do_coredump, 0, "Enable/Disable coredumps"); 177 178 static int set_core_nodump_flag = 0; 179 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 180 0, "Enable setting the NODUMP flag on coredump files"); 181 182 /* 183 * Signal properties and actions. 184 * The array below categorizes the signals and their default actions 185 * according to the following properties: 186 */ 187 #define SA_KILL 0x01 /* terminates process by default */ 188 #define SA_CORE 0x02 /* ditto and coredumps */ 189 #define SA_STOP 0x04 /* suspend process */ 190 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 191 #define SA_IGNORE 0x10 /* ignore by default */ 192 #define SA_CONT 0x20 /* continue if suspended */ 193 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 194 #define SA_PROC 0x80 /* deliverable to any thread */ 195 196 static int sigproptbl[NSIG] = { 197 SA_KILL|SA_PROC, /* SIGHUP */ 198 SA_KILL|SA_PROC, /* SIGINT */ 199 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */ 200 SA_KILL|SA_CORE, /* SIGILL */ 201 SA_KILL|SA_CORE, /* SIGTRAP */ 202 SA_KILL|SA_CORE, /* SIGABRT */ 203 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */ 204 SA_KILL|SA_CORE, /* SIGFPE */ 205 SA_KILL|SA_PROC, /* SIGKILL */ 206 SA_KILL|SA_CORE, /* SIGBUS */ 207 SA_KILL|SA_CORE, /* SIGSEGV */ 208 SA_KILL|SA_CORE, /* SIGSYS */ 209 SA_KILL|SA_PROC, /* SIGPIPE */ 210 SA_KILL|SA_PROC, /* SIGALRM */ 211 SA_KILL|SA_PROC, /* SIGTERM */ 212 SA_IGNORE|SA_PROC, /* SIGURG */ 213 SA_STOP|SA_PROC, /* SIGSTOP */ 214 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */ 215 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */ 216 SA_IGNORE|SA_PROC, /* SIGCHLD */ 217 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */ 218 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */ 219 SA_IGNORE|SA_PROC, /* SIGIO */ 220 SA_KILL, /* SIGXCPU */ 221 SA_KILL, /* SIGXFSZ */ 222 SA_KILL|SA_PROC, /* SIGVTALRM */ 223 SA_KILL|SA_PROC, /* SIGPROF */ 224 SA_IGNORE|SA_PROC, /* SIGWINCH */ 225 SA_IGNORE|SA_PROC, /* SIGINFO */ 226 SA_KILL|SA_PROC, /* SIGUSR1 */ 227 SA_KILL|SA_PROC, /* SIGUSR2 */ 228 }; 229 230 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 231 232 static void 233 sigqueue_start(void) 234 { 235 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 236 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 237 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 238 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 239 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 240 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 241 } 242 243 ksiginfo_t * 244 ksiginfo_alloc(int wait) 245 { 246 int flags; 247 248 flags = M_ZERO; 249 if (! wait) 250 flags |= M_NOWAIT; 251 if (ksiginfo_zone != NULL) 252 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 253 return (NULL); 254 } 255 256 void 257 ksiginfo_free(ksiginfo_t *ksi) 258 { 259 uma_zfree(ksiginfo_zone, ksi); 260 } 261 262 static __inline int 263 ksiginfo_tryfree(ksiginfo_t *ksi) 264 { 265 if (!(ksi->ksi_flags & KSI_EXT)) { 266 uma_zfree(ksiginfo_zone, ksi); 267 return (1); 268 } 269 return (0); 270 } 271 272 void 273 sigqueue_init(sigqueue_t *list, struct proc *p) 274 { 275 SIGEMPTYSET(list->sq_signals); 276 SIGEMPTYSET(list->sq_kill); 277 TAILQ_INIT(&list->sq_list); 278 list->sq_proc = p; 279 list->sq_flags = SQ_INIT; 280 } 281 282 /* 283 * Get a signal's ksiginfo. 284 * Return: 285 * 0 - signal not found 286 * others - signal number 287 */ 288 static int 289 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 290 { 291 struct proc *p = sq->sq_proc; 292 struct ksiginfo *ksi, *next; 293 int count = 0; 294 295 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 296 297 if (!SIGISMEMBER(sq->sq_signals, signo)) 298 return (0); 299 300 if (SIGISMEMBER(sq->sq_kill, signo)) { 301 count++; 302 SIGDELSET(sq->sq_kill, signo); 303 } 304 305 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 306 if (ksi->ksi_signo == signo) { 307 if (count == 0) { 308 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 309 ksi->ksi_sigq = NULL; 310 ksiginfo_copy(ksi, si); 311 if (ksiginfo_tryfree(ksi) && p != NULL) 312 p->p_pendingcnt--; 313 } 314 if (++count > 1) 315 break; 316 } 317 } 318 319 if (count <= 1) 320 SIGDELSET(sq->sq_signals, signo); 321 si->ksi_signo = signo; 322 return (signo); 323 } 324 325 void 326 sigqueue_take(ksiginfo_t *ksi) 327 { 328 struct ksiginfo *kp; 329 struct proc *p; 330 sigqueue_t *sq; 331 332 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 333 return; 334 335 p = sq->sq_proc; 336 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 337 ksi->ksi_sigq = NULL; 338 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 339 p->p_pendingcnt--; 340 341 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 342 kp = TAILQ_NEXT(kp, ksi_link)) { 343 if (kp->ksi_signo == ksi->ksi_signo) 344 break; 345 } 346 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo)) 347 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 348 } 349 350 static int 351 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 352 { 353 struct proc *p = sq->sq_proc; 354 struct ksiginfo *ksi; 355 int ret = 0; 356 357 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 358 359 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 360 SIGADDSET(sq->sq_kill, signo); 361 goto out_set_bit; 362 } 363 364 /* directly insert the ksi, don't copy it */ 365 if (si->ksi_flags & KSI_INS) { 366 if (si->ksi_flags & KSI_HEAD) 367 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 368 else 369 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 370 si->ksi_sigq = sq; 371 goto out_set_bit; 372 } 373 374 if (__predict_false(ksiginfo_zone == NULL)) { 375 SIGADDSET(sq->sq_kill, signo); 376 goto out_set_bit; 377 } 378 379 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 380 signal_overflow++; 381 ret = EAGAIN; 382 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 383 signal_alloc_fail++; 384 ret = EAGAIN; 385 } else { 386 if (p != NULL) 387 p->p_pendingcnt++; 388 ksiginfo_copy(si, ksi); 389 ksi->ksi_signo = signo; 390 if (si->ksi_flags & KSI_HEAD) 391 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 392 else 393 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 394 ksi->ksi_sigq = sq; 395 } 396 397 if ((si->ksi_flags & KSI_TRAP) != 0 || 398 (si->ksi_flags & KSI_SIGQ) == 0) { 399 if (ret != 0) 400 SIGADDSET(sq->sq_kill, signo); 401 ret = 0; 402 goto out_set_bit; 403 } 404 405 if (ret != 0) 406 return (ret); 407 408 out_set_bit: 409 SIGADDSET(sq->sq_signals, signo); 410 return (ret); 411 } 412 413 void 414 sigqueue_flush(sigqueue_t *sq) 415 { 416 struct proc *p = sq->sq_proc; 417 ksiginfo_t *ksi; 418 419 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 420 421 if (p != NULL) 422 PROC_LOCK_ASSERT(p, MA_OWNED); 423 424 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 425 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 426 ksi->ksi_sigq = NULL; 427 if (ksiginfo_tryfree(ksi) && p != NULL) 428 p->p_pendingcnt--; 429 } 430 431 SIGEMPTYSET(sq->sq_signals); 432 SIGEMPTYSET(sq->sq_kill); 433 } 434 435 static void 436 sigqueue_collect_set(sigqueue_t *sq, sigset_t *set) 437 { 438 ksiginfo_t *ksi; 439 440 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 441 442 TAILQ_FOREACH(ksi, &sq->sq_list, ksi_link) 443 SIGADDSET(*set, ksi->ksi_signo); 444 SIGSETOR(*set, sq->sq_kill); 445 } 446 447 static void 448 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, sigset_t *setp) 449 { 450 sigset_t tmp, set; 451 struct proc *p1, *p2; 452 ksiginfo_t *ksi, *next; 453 454 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 455 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 456 /* 457 * make a copy, this allows setp to point to src or dst 458 * sq_signals without trouble. 459 */ 460 set = *setp; 461 p1 = src->sq_proc; 462 p2 = dst->sq_proc; 463 /* Move siginfo to target list */ 464 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 465 if (SIGISMEMBER(set, ksi->ksi_signo)) { 466 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 467 if (p1 != NULL) 468 p1->p_pendingcnt--; 469 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 470 ksi->ksi_sigq = dst; 471 if (p2 != NULL) 472 p2->p_pendingcnt++; 473 } 474 } 475 476 /* Move pending bits to target list */ 477 tmp = src->sq_kill; 478 SIGSETAND(tmp, set); 479 SIGSETOR(dst->sq_kill, tmp); 480 SIGSETNAND(src->sq_kill, tmp); 481 482 tmp = src->sq_signals; 483 SIGSETAND(tmp, set); 484 SIGSETOR(dst->sq_signals, tmp); 485 SIGSETNAND(src->sq_signals, tmp); 486 487 /* Finally, rescan src queue and set pending bits for it */ 488 sigqueue_collect_set(src, &src->sq_signals); 489 } 490 491 static void 492 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 493 { 494 sigset_t set; 495 496 SIGEMPTYSET(set); 497 SIGADDSET(set, signo); 498 sigqueue_move_set(src, dst, &set); 499 } 500 501 static void 502 sigqueue_delete_set(sigqueue_t *sq, sigset_t *set) 503 { 504 struct proc *p = sq->sq_proc; 505 ksiginfo_t *ksi, *next; 506 507 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 508 509 /* Remove siginfo queue */ 510 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 511 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 512 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 513 ksi->ksi_sigq = NULL; 514 if (ksiginfo_tryfree(ksi) && p != NULL) 515 p->p_pendingcnt--; 516 } 517 } 518 SIGSETNAND(sq->sq_kill, *set); 519 SIGSETNAND(sq->sq_signals, *set); 520 /* Finally, rescan queue and set pending bits for it */ 521 sigqueue_collect_set(sq, &sq->sq_signals); 522 } 523 524 void 525 sigqueue_delete(sigqueue_t *sq, int signo) 526 { 527 sigset_t set; 528 529 SIGEMPTYSET(set); 530 SIGADDSET(set, signo); 531 sigqueue_delete_set(sq, &set); 532 } 533 534 /* Remove a set of signals for a process */ 535 static void 536 sigqueue_delete_set_proc(struct proc *p, sigset_t *set) 537 { 538 sigqueue_t worklist; 539 struct thread *td0; 540 541 PROC_LOCK_ASSERT(p, MA_OWNED); 542 543 sigqueue_init(&worklist, NULL); 544 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 545 546 FOREACH_THREAD_IN_PROC(p, td0) 547 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 548 549 sigqueue_flush(&worklist); 550 } 551 552 void 553 sigqueue_delete_proc(struct proc *p, int signo) 554 { 555 sigset_t set; 556 557 SIGEMPTYSET(set); 558 SIGADDSET(set, signo); 559 sigqueue_delete_set_proc(p, &set); 560 } 561 562 static void 563 sigqueue_delete_stopmask_proc(struct proc *p) 564 { 565 sigset_t set; 566 567 SIGEMPTYSET(set); 568 SIGADDSET(set, SIGSTOP); 569 SIGADDSET(set, SIGTSTP); 570 SIGADDSET(set, SIGTTIN); 571 SIGADDSET(set, SIGTTOU); 572 sigqueue_delete_set_proc(p, &set); 573 } 574 575 /* 576 * Determine signal that should be delivered to process p, the current 577 * process, 0 if none. If there is a pending stop signal with default 578 * action, the process stops in issignal(). 579 */ 580 int 581 cursig(struct thread *td, int stop_allowed) 582 { 583 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 584 KASSERT(stop_allowed == SIG_STOP_ALLOWED || 585 stop_allowed == SIG_STOP_NOT_ALLOWED, ("cursig: stop_allowed")); 586 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 587 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 588 return (SIGPENDING(td) ? issignal(td, stop_allowed) : 0); 589 } 590 591 /* 592 * Arrange for ast() to handle unmasked pending signals on return to user 593 * mode. This must be called whenever a signal is added to td_sigqueue or 594 * unmasked in td_sigmask. 595 */ 596 void 597 signotify(struct thread *td) 598 { 599 struct proc *p; 600 601 p = td->td_proc; 602 603 PROC_LOCK_ASSERT(p, MA_OWNED); 604 605 if (SIGPENDING(td)) { 606 thread_lock(td); 607 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 608 thread_unlock(td); 609 } 610 } 611 612 int 613 sigonstack(size_t sp) 614 { 615 struct thread *td = curthread; 616 617 return ((td->td_pflags & TDP_ALTSTACK) ? 618 #if defined(COMPAT_43) 619 ((td->td_sigstk.ss_size == 0) ? 620 (td->td_sigstk.ss_flags & SS_ONSTACK) : 621 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 622 #else 623 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 624 #endif 625 : 0); 626 } 627 628 static __inline int 629 sigprop(int sig) 630 { 631 632 if (sig > 0 && sig < NSIG) 633 return (sigproptbl[_SIG_IDX(sig)]); 634 return (0); 635 } 636 637 int 638 sig_ffs(sigset_t *set) 639 { 640 int i; 641 642 for (i = 0; i < _SIG_WORDS; i++) 643 if (set->__bits[i]) 644 return (ffs(set->__bits[i]) + (i * 32)); 645 return (0); 646 } 647 648 /* 649 * kern_sigaction 650 * sigaction 651 * freebsd4_sigaction 652 * osigaction 653 */ 654 int 655 kern_sigaction(td, sig, act, oact, flags) 656 struct thread *td; 657 register int sig; 658 struct sigaction *act, *oact; 659 int flags; 660 { 661 struct sigacts *ps; 662 struct proc *p = td->td_proc; 663 664 if (!_SIG_VALID(sig)) 665 return (EINVAL); 666 667 PROC_LOCK(p); 668 ps = p->p_sigacts; 669 mtx_lock(&ps->ps_mtx); 670 if (oact) { 671 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 672 oact->sa_flags = 0; 673 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 674 oact->sa_flags |= SA_ONSTACK; 675 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 676 oact->sa_flags |= SA_RESTART; 677 if (SIGISMEMBER(ps->ps_sigreset, sig)) 678 oact->sa_flags |= SA_RESETHAND; 679 if (SIGISMEMBER(ps->ps_signodefer, sig)) 680 oact->sa_flags |= SA_NODEFER; 681 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 682 oact->sa_flags |= SA_SIGINFO; 683 oact->sa_sigaction = 684 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 685 } else 686 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 687 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 688 oact->sa_flags |= SA_NOCLDSTOP; 689 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 690 oact->sa_flags |= SA_NOCLDWAIT; 691 } 692 if (act) { 693 if ((sig == SIGKILL || sig == SIGSTOP) && 694 act->sa_handler != SIG_DFL) { 695 mtx_unlock(&ps->ps_mtx); 696 PROC_UNLOCK(p); 697 return (EINVAL); 698 } 699 700 /* 701 * Change setting atomically. 702 */ 703 704 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 705 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 706 if (act->sa_flags & SA_SIGINFO) { 707 ps->ps_sigact[_SIG_IDX(sig)] = 708 (__sighandler_t *)act->sa_sigaction; 709 SIGADDSET(ps->ps_siginfo, sig); 710 } else { 711 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 712 SIGDELSET(ps->ps_siginfo, sig); 713 } 714 if (!(act->sa_flags & SA_RESTART)) 715 SIGADDSET(ps->ps_sigintr, sig); 716 else 717 SIGDELSET(ps->ps_sigintr, sig); 718 if (act->sa_flags & SA_ONSTACK) 719 SIGADDSET(ps->ps_sigonstack, sig); 720 else 721 SIGDELSET(ps->ps_sigonstack, sig); 722 if (act->sa_flags & SA_RESETHAND) 723 SIGADDSET(ps->ps_sigreset, sig); 724 else 725 SIGDELSET(ps->ps_sigreset, sig); 726 if (act->sa_flags & SA_NODEFER) 727 SIGADDSET(ps->ps_signodefer, sig); 728 else 729 SIGDELSET(ps->ps_signodefer, sig); 730 if (sig == SIGCHLD) { 731 if (act->sa_flags & SA_NOCLDSTOP) 732 ps->ps_flag |= PS_NOCLDSTOP; 733 else 734 ps->ps_flag &= ~PS_NOCLDSTOP; 735 if (act->sa_flags & SA_NOCLDWAIT) { 736 /* 737 * Paranoia: since SA_NOCLDWAIT is implemented 738 * by reparenting the dying child to PID 1 (and 739 * trust it to reap the zombie), PID 1 itself 740 * is forbidden to set SA_NOCLDWAIT. 741 */ 742 if (p->p_pid == 1) 743 ps->ps_flag &= ~PS_NOCLDWAIT; 744 else 745 ps->ps_flag |= PS_NOCLDWAIT; 746 } else 747 ps->ps_flag &= ~PS_NOCLDWAIT; 748 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 749 ps->ps_flag |= PS_CLDSIGIGN; 750 else 751 ps->ps_flag &= ~PS_CLDSIGIGN; 752 } 753 /* 754 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 755 * and for signals set to SIG_DFL where the default is to 756 * ignore. However, don't put SIGCONT in ps_sigignore, as we 757 * have to restart the process. 758 */ 759 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 760 (sigprop(sig) & SA_IGNORE && 761 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 762 /* never to be seen again */ 763 sigqueue_delete_proc(p, sig); 764 if (sig != SIGCONT) 765 /* easier in psignal */ 766 SIGADDSET(ps->ps_sigignore, sig); 767 SIGDELSET(ps->ps_sigcatch, sig); 768 } else { 769 SIGDELSET(ps->ps_sigignore, sig); 770 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 771 SIGDELSET(ps->ps_sigcatch, sig); 772 else 773 SIGADDSET(ps->ps_sigcatch, sig); 774 } 775 #ifdef COMPAT_FREEBSD4 776 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 777 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 778 (flags & KSA_FREEBSD4) == 0) 779 SIGDELSET(ps->ps_freebsd4, sig); 780 else 781 SIGADDSET(ps->ps_freebsd4, sig); 782 #endif 783 #ifdef COMPAT_43 784 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 785 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 786 (flags & KSA_OSIGSET) == 0) 787 SIGDELSET(ps->ps_osigset, sig); 788 else 789 SIGADDSET(ps->ps_osigset, sig); 790 #endif 791 } 792 mtx_unlock(&ps->ps_mtx); 793 PROC_UNLOCK(p); 794 return (0); 795 } 796 797 #ifndef _SYS_SYSPROTO_H_ 798 struct sigaction_args { 799 int sig; 800 struct sigaction *act; 801 struct sigaction *oact; 802 }; 803 #endif 804 int 805 sigaction(td, uap) 806 struct thread *td; 807 register struct sigaction_args *uap; 808 { 809 struct sigaction act, oact; 810 register struct sigaction *actp, *oactp; 811 int error; 812 813 actp = (uap->act != NULL) ? &act : NULL; 814 oactp = (uap->oact != NULL) ? &oact : NULL; 815 if (actp) { 816 error = copyin(uap->act, actp, sizeof(act)); 817 if (error) 818 return (error); 819 } 820 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 821 if (oactp && !error) 822 error = copyout(oactp, uap->oact, sizeof(oact)); 823 return (error); 824 } 825 826 #ifdef COMPAT_FREEBSD4 827 #ifndef _SYS_SYSPROTO_H_ 828 struct freebsd4_sigaction_args { 829 int sig; 830 struct sigaction *act; 831 struct sigaction *oact; 832 }; 833 #endif 834 int 835 freebsd4_sigaction(td, uap) 836 struct thread *td; 837 register struct freebsd4_sigaction_args *uap; 838 { 839 struct sigaction act, oact; 840 register struct sigaction *actp, *oactp; 841 int error; 842 843 844 actp = (uap->act != NULL) ? &act : NULL; 845 oactp = (uap->oact != NULL) ? &oact : NULL; 846 if (actp) { 847 error = copyin(uap->act, actp, sizeof(act)); 848 if (error) 849 return (error); 850 } 851 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 852 if (oactp && !error) 853 error = copyout(oactp, uap->oact, sizeof(oact)); 854 return (error); 855 } 856 #endif /* COMAPT_FREEBSD4 */ 857 858 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 859 #ifndef _SYS_SYSPROTO_H_ 860 struct osigaction_args { 861 int signum; 862 struct osigaction *nsa; 863 struct osigaction *osa; 864 }; 865 #endif 866 int 867 osigaction(td, uap) 868 struct thread *td; 869 register struct osigaction_args *uap; 870 { 871 struct osigaction sa; 872 struct sigaction nsa, osa; 873 register struct sigaction *nsap, *osap; 874 int error; 875 876 if (uap->signum <= 0 || uap->signum >= ONSIG) 877 return (EINVAL); 878 879 nsap = (uap->nsa != NULL) ? &nsa : NULL; 880 osap = (uap->osa != NULL) ? &osa : NULL; 881 882 if (nsap) { 883 error = copyin(uap->nsa, &sa, sizeof(sa)); 884 if (error) 885 return (error); 886 nsap->sa_handler = sa.sa_handler; 887 nsap->sa_flags = sa.sa_flags; 888 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 889 } 890 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 891 if (osap && !error) { 892 sa.sa_handler = osap->sa_handler; 893 sa.sa_flags = osap->sa_flags; 894 SIG2OSIG(osap->sa_mask, sa.sa_mask); 895 error = copyout(&sa, uap->osa, sizeof(sa)); 896 } 897 return (error); 898 } 899 900 #if !defined(__i386__) 901 /* Avoid replicating the same stub everywhere */ 902 int 903 osigreturn(td, uap) 904 struct thread *td; 905 struct osigreturn_args *uap; 906 { 907 908 return (nosys(td, (struct nosys_args *)uap)); 909 } 910 #endif 911 #endif /* COMPAT_43 */ 912 913 /* 914 * Initialize signal state for process 0; 915 * set to ignore signals that are ignored by default. 916 */ 917 void 918 siginit(p) 919 struct proc *p; 920 { 921 register int i; 922 struct sigacts *ps; 923 924 PROC_LOCK(p); 925 ps = p->p_sigacts; 926 mtx_lock(&ps->ps_mtx); 927 for (i = 1; i <= NSIG; i++) 928 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 929 SIGADDSET(ps->ps_sigignore, i); 930 mtx_unlock(&ps->ps_mtx); 931 PROC_UNLOCK(p); 932 } 933 934 /* 935 * Reset signals for an exec of the specified process. 936 */ 937 void 938 execsigs(struct proc *p) 939 { 940 struct sigacts *ps; 941 int sig; 942 struct thread *td; 943 944 /* 945 * Reset caught signals. Held signals remain held 946 * through td_sigmask (unless they were caught, 947 * and are now ignored by default). 948 */ 949 PROC_LOCK_ASSERT(p, MA_OWNED); 950 td = FIRST_THREAD_IN_PROC(p); 951 ps = p->p_sigacts; 952 mtx_lock(&ps->ps_mtx); 953 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 954 sig = sig_ffs(&ps->ps_sigcatch); 955 SIGDELSET(ps->ps_sigcatch, sig); 956 if (sigprop(sig) & SA_IGNORE) { 957 if (sig != SIGCONT) 958 SIGADDSET(ps->ps_sigignore, sig); 959 sigqueue_delete_proc(p, sig); 960 } 961 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 962 } 963 /* 964 * Reset stack state to the user stack. 965 * Clear set of signals caught on the signal stack. 966 */ 967 td->td_sigstk.ss_flags = SS_DISABLE; 968 td->td_sigstk.ss_size = 0; 969 td->td_sigstk.ss_sp = 0; 970 td->td_pflags &= ~TDP_ALTSTACK; 971 /* 972 * Reset no zombies if child dies flag as Solaris does. 973 */ 974 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 975 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 976 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 977 mtx_unlock(&ps->ps_mtx); 978 } 979 980 /* 981 * kern_sigprocmask() 982 * 983 * Manipulate signal mask. 984 */ 985 int 986 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 987 int flags) 988 { 989 sigset_t new_block, oset1; 990 struct proc *p; 991 int error; 992 993 p = td->td_proc; 994 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 995 PROC_LOCK(p); 996 if (oset != NULL) 997 *oset = td->td_sigmask; 998 999 error = 0; 1000 SIGEMPTYSET(new_block); 1001 if (set != NULL) { 1002 switch (how) { 1003 case SIG_BLOCK: 1004 SIG_CANTMASK(*set); 1005 oset1 = td->td_sigmask; 1006 SIGSETOR(td->td_sigmask, *set); 1007 new_block = td->td_sigmask; 1008 SIGSETNAND(new_block, oset1); 1009 break; 1010 case SIG_UNBLOCK: 1011 SIGSETNAND(td->td_sigmask, *set); 1012 signotify(td); 1013 break; 1014 case SIG_SETMASK: 1015 SIG_CANTMASK(*set); 1016 oset1 = td->td_sigmask; 1017 if (flags & SIGPROCMASK_OLD) 1018 SIGSETLO(td->td_sigmask, *set); 1019 else 1020 td->td_sigmask = *set; 1021 new_block = td->td_sigmask; 1022 SIGSETNAND(new_block, oset1); 1023 signotify(td); 1024 break; 1025 default: 1026 error = EINVAL; 1027 break; 1028 } 1029 } 1030 1031 /* 1032 * The new_block set contains signals that were not previously 1033 * blocked, but are blocked now. 1034 * 1035 * In case we block any signal that was not previously blocked 1036 * for td, and process has the signal pending, try to schedule 1037 * signal delivery to some thread that does not block the signal, 1038 * possibly waking it up. 1039 */ 1040 if (p->p_numthreads != 1) 1041 reschedule_signals(p, new_block, flags); 1042 1043 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1044 PROC_UNLOCK(p); 1045 return (error); 1046 } 1047 1048 #ifndef _SYS_SYSPROTO_H_ 1049 struct sigprocmask_args { 1050 int how; 1051 const sigset_t *set; 1052 sigset_t *oset; 1053 }; 1054 #endif 1055 int 1056 sigprocmask(td, uap) 1057 register struct thread *td; 1058 struct sigprocmask_args *uap; 1059 { 1060 sigset_t set, oset; 1061 sigset_t *setp, *osetp; 1062 int error; 1063 1064 setp = (uap->set != NULL) ? &set : NULL; 1065 osetp = (uap->oset != NULL) ? &oset : NULL; 1066 if (setp) { 1067 error = copyin(uap->set, setp, sizeof(set)); 1068 if (error) 1069 return (error); 1070 } 1071 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1072 if (osetp && !error) { 1073 error = copyout(osetp, uap->oset, sizeof(oset)); 1074 } 1075 return (error); 1076 } 1077 1078 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1079 #ifndef _SYS_SYSPROTO_H_ 1080 struct osigprocmask_args { 1081 int how; 1082 osigset_t mask; 1083 }; 1084 #endif 1085 int 1086 osigprocmask(td, uap) 1087 register struct thread *td; 1088 struct osigprocmask_args *uap; 1089 { 1090 sigset_t set, oset; 1091 int error; 1092 1093 OSIG2SIG(uap->mask, set); 1094 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1095 SIG2OSIG(oset, td->td_retval[0]); 1096 return (error); 1097 } 1098 #endif /* COMPAT_43 */ 1099 1100 int 1101 sigwait(struct thread *td, struct sigwait_args *uap) 1102 { 1103 ksiginfo_t ksi; 1104 sigset_t set; 1105 int error; 1106 1107 error = copyin(uap->set, &set, sizeof(set)); 1108 if (error) { 1109 td->td_retval[0] = error; 1110 return (0); 1111 } 1112 1113 error = kern_sigtimedwait(td, set, &ksi, NULL); 1114 if (error) { 1115 if (error == ERESTART) 1116 return (error); 1117 td->td_retval[0] = error; 1118 return (0); 1119 } 1120 1121 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1122 td->td_retval[0] = error; 1123 return (0); 1124 } 1125 1126 int 1127 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1128 { 1129 struct timespec ts; 1130 struct timespec *timeout; 1131 sigset_t set; 1132 ksiginfo_t ksi; 1133 int error; 1134 1135 if (uap->timeout) { 1136 error = copyin(uap->timeout, &ts, sizeof(ts)); 1137 if (error) 1138 return (error); 1139 1140 timeout = &ts; 1141 } else 1142 timeout = NULL; 1143 1144 error = copyin(uap->set, &set, sizeof(set)); 1145 if (error) 1146 return (error); 1147 1148 error = kern_sigtimedwait(td, set, &ksi, timeout); 1149 if (error) 1150 return (error); 1151 1152 if (uap->info) 1153 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1154 1155 if (error == 0) 1156 td->td_retval[0] = ksi.ksi_signo; 1157 return (error); 1158 } 1159 1160 int 1161 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1162 { 1163 ksiginfo_t ksi; 1164 sigset_t set; 1165 int error; 1166 1167 error = copyin(uap->set, &set, sizeof(set)); 1168 if (error) 1169 return (error); 1170 1171 error = kern_sigtimedwait(td, set, &ksi, NULL); 1172 if (error) 1173 return (error); 1174 1175 if (uap->info) 1176 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1177 1178 if (error == 0) 1179 td->td_retval[0] = ksi.ksi_signo; 1180 return (error); 1181 } 1182 1183 int 1184 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1185 struct timespec *timeout) 1186 { 1187 struct sigacts *ps; 1188 sigset_t savedmask; 1189 struct proc *p; 1190 int error, sig, hz, i, timevalid = 0; 1191 struct timespec rts, ets, ts; 1192 struct timeval tv; 1193 1194 p = td->td_proc; 1195 error = 0; 1196 sig = 0; 1197 ets.tv_sec = 0; 1198 ets.tv_nsec = 0; 1199 SIG_CANTMASK(waitset); 1200 1201 PROC_LOCK(p); 1202 ps = p->p_sigacts; 1203 savedmask = td->td_sigmask; 1204 if (timeout) { 1205 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1206 timevalid = 1; 1207 getnanouptime(&rts); 1208 ets = rts; 1209 timespecadd(&ets, timeout); 1210 } 1211 } 1212 1213 restart: 1214 for (i = 1; i <= _SIG_MAXSIG; ++i) { 1215 if (!SIGISMEMBER(waitset, i)) 1216 continue; 1217 if (!SIGISMEMBER(td->td_sigqueue.sq_signals, i)) { 1218 if (SIGISMEMBER(p->p_sigqueue.sq_signals, i)) { 1219 sigqueue_move(&p->p_sigqueue, 1220 &td->td_sigqueue, i); 1221 } else 1222 continue; 1223 } 1224 1225 SIGFILLSET(td->td_sigmask); 1226 SIG_CANTMASK(td->td_sigmask); 1227 SIGDELSET(td->td_sigmask, i); 1228 mtx_lock(&ps->ps_mtx); 1229 sig = cursig(td, SIG_STOP_ALLOWED); 1230 mtx_unlock(&ps->ps_mtx); 1231 if (sig) 1232 goto out; 1233 else { 1234 /* 1235 * Because cursig() may have stopped current thread, 1236 * after it is resumed, things may have already been 1237 * changed, it should rescan any pending signals. 1238 */ 1239 goto restart; 1240 } 1241 } 1242 1243 if (error) 1244 goto out; 1245 1246 /* 1247 * POSIX says this must be checked after looking for pending 1248 * signals. 1249 */ 1250 if (timeout) { 1251 if (!timevalid) { 1252 error = EINVAL; 1253 goto out; 1254 } 1255 getnanouptime(&rts); 1256 if (timespeccmp(&rts, &ets, >=)) { 1257 error = EAGAIN; 1258 goto out; 1259 } 1260 ts = ets; 1261 timespecsub(&ts, &rts); 1262 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1263 hz = tvtohz(&tv); 1264 } else 1265 hz = 0; 1266 1267 td->td_sigmask = savedmask; 1268 SIGSETNAND(td->td_sigmask, waitset); 1269 signotify(td); 1270 error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz); 1271 if (timeout) { 1272 if (error == ERESTART) { 1273 /* timeout can not be restarted. */ 1274 error = EINTR; 1275 } else if (error == EAGAIN) { 1276 /* will calculate timeout by ourself. */ 1277 error = 0; 1278 } 1279 } 1280 goto restart; 1281 1282 out: 1283 td->td_sigmask = savedmask; 1284 signotify(td); 1285 if (sig) { 1286 ksiginfo_init(ksi); 1287 sigqueue_get(&td->td_sigqueue, sig, ksi); 1288 ksi->ksi_signo = sig; 1289 1290 SDT_PROBE(proc, kernel, , signal_clear, sig, ksi, 0, 0, 0); 1291 1292 if (ksi->ksi_code == SI_TIMER) 1293 itimer_accept(p, ksi->ksi_timerid, ksi); 1294 error = 0; 1295 1296 #ifdef KTRACE 1297 if (KTRPOINT(td, KTR_PSIG)) { 1298 sig_t action; 1299 1300 mtx_lock(&ps->ps_mtx); 1301 action = ps->ps_sigact[_SIG_IDX(sig)]; 1302 mtx_unlock(&ps->ps_mtx); 1303 ktrpsig(sig, action, &td->td_sigmask, 0); 1304 } 1305 #endif 1306 if (sig == SIGKILL) 1307 sigexit(td, sig); 1308 } 1309 PROC_UNLOCK(p); 1310 return (error); 1311 } 1312 1313 #ifndef _SYS_SYSPROTO_H_ 1314 struct sigpending_args { 1315 sigset_t *set; 1316 }; 1317 #endif 1318 int 1319 sigpending(td, uap) 1320 struct thread *td; 1321 struct sigpending_args *uap; 1322 { 1323 struct proc *p = td->td_proc; 1324 sigset_t pending; 1325 1326 PROC_LOCK(p); 1327 pending = p->p_sigqueue.sq_signals; 1328 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1329 PROC_UNLOCK(p); 1330 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1331 } 1332 1333 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1334 #ifndef _SYS_SYSPROTO_H_ 1335 struct osigpending_args { 1336 int dummy; 1337 }; 1338 #endif 1339 int 1340 osigpending(td, uap) 1341 struct thread *td; 1342 struct osigpending_args *uap; 1343 { 1344 struct proc *p = td->td_proc; 1345 sigset_t pending; 1346 1347 PROC_LOCK(p); 1348 pending = p->p_sigqueue.sq_signals; 1349 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1350 PROC_UNLOCK(p); 1351 SIG2OSIG(pending, td->td_retval[0]); 1352 return (0); 1353 } 1354 #endif /* COMPAT_43 */ 1355 1356 #if defined(COMPAT_43) 1357 /* 1358 * Generalized interface signal handler, 4.3-compatible. 1359 */ 1360 #ifndef _SYS_SYSPROTO_H_ 1361 struct osigvec_args { 1362 int signum; 1363 struct sigvec *nsv; 1364 struct sigvec *osv; 1365 }; 1366 #endif 1367 /* ARGSUSED */ 1368 int 1369 osigvec(td, uap) 1370 struct thread *td; 1371 register struct osigvec_args *uap; 1372 { 1373 struct sigvec vec; 1374 struct sigaction nsa, osa; 1375 register struct sigaction *nsap, *osap; 1376 int error; 1377 1378 if (uap->signum <= 0 || uap->signum >= ONSIG) 1379 return (EINVAL); 1380 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1381 osap = (uap->osv != NULL) ? &osa : NULL; 1382 if (nsap) { 1383 error = copyin(uap->nsv, &vec, sizeof(vec)); 1384 if (error) 1385 return (error); 1386 nsap->sa_handler = vec.sv_handler; 1387 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1388 nsap->sa_flags = vec.sv_flags; 1389 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1390 } 1391 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1392 if (osap && !error) { 1393 vec.sv_handler = osap->sa_handler; 1394 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1395 vec.sv_flags = osap->sa_flags; 1396 vec.sv_flags &= ~SA_NOCLDWAIT; 1397 vec.sv_flags ^= SA_RESTART; 1398 error = copyout(&vec, uap->osv, sizeof(vec)); 1399 } 1400 return (error); 1401 } 1402 1403 #ifndef _SYS_SYSPROTO_H_ 1404 struct osigblock_args { 1405 int mask; 1406 }; 1407 #endif 1408 int 1409 osigblock(td, uap) 1410 register struct thread *td; 1411 struct osigblock_args *uap; 1412 { 1413 sigset_t set, oset; 1414 1415 OSIG2SIG(uap->mask, set); 1416 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1417 SIG2OSIG(oset, td->td_retval[0]); 1418 return (0); 1419 } 1420 1421 #ifndef _SYS_SYSPROTO_H_ 1422 struct osigsetmask_args { 1423 int mask; 1424 }; 1425 #endif 1426 int 1427 osigsetmask(td, uap) 1428 struct thread *td; 1429 struct osigsetmask_args *uap; 1430 { 1431 sigset_t set, oset; 1432 1433 OSIG2SIG(uap->mask, set); 1434 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1435 SIG2OSIG(oset, td->td_retval[0]); 1436 return (0); 1437 } 1438 #endif /* COMPAT_43 */ 1439 1440 /* 1441 * Suspend calling thread until signal, providing mask to be set in the 1442 * meantime. 1443 */ 1444 #ifndef _SYS_SYSPROTO_H_ 1445 struct sigsuspend_args { 1446 const sigset_t *sigmask; 1447 }; 1448 #endif 1449 /* ARGSUSED */ 1450 int 1451 sigsuspend(td, uap) 1452 struct thread *td; 1453 struct sigsuspend_args *uap; 1454 { 1455 sigset_t mask; 1456 int error; 1457 1458 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1459 if (error) 1460 return (error); 1461 return (kern_sigsuspend(td, mask)); 1462 } 1463 1464 int 1465 kern_sigsuspend(struct thread *td, sigset_t mask) 1466 { 1467 struct proc *p = td->td_proc; 1468 int has_sig, sig; 1469 1470 /* 1471 * When returning from sigsuspend, we want 1472 * the old mask to be restored after the 1473 * signal handler has finished. Thus, we 1474 * save it here and mark the sigacts structure 1475 * to indicate this. 1476 */ 1477 PROC_LOCK(p); 1478 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1479 SIGPROCMASK_PROC_LOCKED); 1480 td->td_pflags |= TDP_OLDMASK; 1481 1482 /* 1483 * Process signals now. Otherwise, we can get spurious wakeup 1484 * due to signal entered process queue, but delivered to other 1485 * thread. But sigsuspend should return only on signal 1486 * delivery. 1487 */ 1488 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1489 for (has_sig = 0; !has_sig;) { 1490 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1491 0) == 0) 1492 /* void */; 1493 thread_suspend_check(0); 1494 mtx_lock(&p->p_sigacts->ps_mtx); 1495 while ((sig = cursig(td, SIG_STOP_ALLOWED)) != 0) 1496 has_sig += postsig(sig); 1497 mtx_unlock(&p->p_sigacts->ps_mtx); 1498 } 1499 PROC_UNLOCK(p); 1500 return (EJUSTRETURN); 1501 } 1502 1503 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1504 /* 1505 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1506 * convention: libc stub passes mask, not pointer, to save a copyin. 1507 */ 1508 #ifndef _SYS_SYSPROTO_H_ 1509 struct osigsuspend_args { 1510 osigset_t mask; 1511 }; 1512 #endif 1513 /* ARGSUSED */ 1514 int 1515 osigsuspend(td, uap) 1516 struct thread *td; 1517 struct osigsuspend_args *uap; 1518 { 1519 sigset_t mask; 1520 1521 OSIG2SIG(uap->mask, mask); 1522 return (kern_sigsuspend(td, mask)); 1523 } 1524 #endif /* COMPAT_43 */ 1525 1526 #if defined(COMPAT_43) 1527 #ifndef _SYS_SYSPROTO_H_ 1528 struct osigstack_args { 1529 struct sigstack *nss; 1530 struct sigstack *oss; 1531 }; 1532 #endif 1533 /* ARGSUSED */ 1534 int 1535 osigstack(td, uap) 1536 struct thread *td; 1537 register struct osigstack_args *uap; 1538 { 1539 struct sigstack nss, oss; 1540 int error = 0; 1541 1542 if (uap->nss != NULL) { 1543 error = copyin(uap->nss, &nss, sizeof(nss)); 1544 if (error) 1545 return (error); 1546 } 1547 oss.ss_sp = td->td_sigstk.ss_sp; 1548 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1549 if (uap->nss != NULL) { 1550 td->td_sigstk.ss_sp = nss.ss_sp; 1551 td->td_sigstk.ss_size = 0; 1552 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1553 td->td_pflags |= TDP_ALTSTACK; 1554 } 1555 if (uap->oss != NULL) 1556 error = copyout(&oss, uap->oss, sizeof(oss)); 1557 1558 return (error); 1559 } 1560 #endif /* COMPAT_43 */ 1561 1562 #ifndef _SYS_SYSPROTO_H_ 1563 struct sigaltstack_args { 1564 stack_t *ss; 1565 stack_t *oss; 1566 }; 1567 #endif 1568 /* ARGSUSED */ 1569 int 1570 sigaltstack(td, uap) 1571 struct thread *td; 1572 register struct sigaltstack_args *uap; 1573 { 1574 stack_t ss, oss; 1575 int error; 1576 1577 if (uap->ss != NULL) { 1578 error = copyin(uap->ss, &ss, sizeof(ss)); 1579 if (error) 1580 return (error); 1581 } 1582 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1583 (uap->oss != NULL) ? &oss : NULL); 1584 if (error) 1585 return (error); 1586 if (uap->oss != NULL) 1587 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1588 return (error); 1589 } 1590 1591 int 1592 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1593 { 1594 struct proc *p = td->td_proc; 1595 int oonstack; 1596 1597 oonstack = sigonstack(cpu_getstack(td)); 1598 1599 if (oss != NULL) { 1600 *oss = td->td_sigstk; 1601 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1602 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1603 } 1604 1605 if (ss != NULL) { 1606 if (oonstack) 1607 return (EPERM); 1608 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1609 return (EINVAL); 1610 if (!(ss->ss_flags & SS_DISABLE)) { 1611 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1612 return (ENOMEM); 1613 1614 td->td_sigstk = *ss; 1615 td->td_pflags |= TDP_ALTSTACK; 1616 } else { 1617 td->td_pflags &= ~TDP_ALTSTACK; 1618 } 1619 } 1620 return (0); 1621 } 1622 1623 /* 1624 * Common code for kill process group/broadcast kill. 1625 * cp is calling process. 1626 */ 1627 static int 1628 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1629 { 1630 struct proc *p; 1631 struct pgrp *pgrp; 1632 int nfound = 0; 1633 1634 if (all) { 1635 /* 1636 * broadcast 1637 */ 1638 sx_slock(&allproc_lock); 1639 FOREACH_PROC_IN_SYSTEM(p) { 1640 PROC_LOCK(p); 1641 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1642 p == td->td_proc || p->p_state == PRS_NEW) { 1643 PROC_UNLOCK(p); 1644 continue; 1645 } 1646 if (p_cansignal(td, p, sig) == 0) { 1647 nfound++; 1648 if (sig) 1649 pksignal(p, sig, ksi); 1650 } 1651 PROC_UNLOCK(p); 1652 } 1653 sx_sunlock(&allproc_lock); 1654 } else { 1655 sx_slock(&proctree_lock); 1656 if (pgid == 0) { 1657 /* 1658 * zero pgid means send to my process group. 1659 */ 1660 pgrp = td->td_proc->p_pgrp; 1661 PGRP_LOCK(pgrp); 1662 } else { 1663 pgrp = pgfind(pgid); 1664 if (pgrp == NULL) { 1665 sx_sunlock(&proctree_lock); 1666 return (ESRCH); 1667 } 1668 } 1669 sx_sunlock(&proctree_lock); 1670 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1671 PROC_LOCK(p); 1672 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1673 p->p_state == PRS_NEW ) { 1674 PROC_UNLOCK(p); 1675 continue; 1676 } 1677 if (p_cansignal(td, p, sig) == 0) { 1678 nfound++; 1679 if (sig) 1680 pksignal(p, sig, ksi); 1681 } 1682 PROC_UNLOCK(p); 1683 } 1684 PGRP_UNLOCK(pgrp); 1685 } 1686 return (nfound ? 0 : ESRCH); 1687 } 1688 1689 #ifndef _SYS_SYSPROTO_H_ 1690 struct kill_args { 1691 int pid; 1692 int signum; 1693 }; 1694 #endif 1695 /* ARGSUSED */ 1696 int 1697 kill(struct thread *td, struct kill_args *uap) 1698 { 1699 ksiginfo_t ksi; 1700 struct proc *p; 1701 int error; 1702 1703 AUDIT_ARG_SIGNUM(uap->signum); 1704 AUDIT_ARG_PID(uap->pid); 1705 if ((u_int)uap->signum > _SIG_MAXSIG) 1706 return (EINVAL); 1707 1708 ksiginfo_init(&ksi); 1709 ksi.ksi_signo = uap->signum; 1710 ksi.ksi_code = SI_USER; 1711 ksi.ksi_pid = td->td_proc->p_pid; 1712 ksi.ksi_uid = td->td_ucred->cr_ruid; 1713 1714 if (uap->pid > 0) { 1715 /* kill single process */ 1716 if ((p = pfind(uap->pid)) == NULL) { 1717 if ((p = zpfind(uap->pid)) == NULL) 1718 return (ESRCH); 1719 } 1720 AUDIT_ARG_PROCESS(p); 1721 error = p_cansignal(td, p, uap->signum); 1722 if (error == 0 && uap->signum) 1723 pksignal(p, uap->signum, &ksi); 1724 PROC_UNLOCK(p); 1725 return (error); 1726 } 1727 switch (uap->pid) { 1728 case -1: /* broadcast signal */ 1729 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1730 case 0: /* signal own process group */ 1731 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1732 default: /* negative explicit process group */ 1733 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1734 } 1735 /* NOTREACHED */ 1736 } 1737 1738 #if defined(COMPAT_43) 1739 #ifndef _SYS_SYSPROTO_H_ 1740 struct okillpg_args { 1741 int pgid; 1742 int signum; 1743 }; 1744 #endif 1745 /* ARGSUSED */ 1746 int 1747 okillpg(struct thread *td, struct okillpg_args *uap) 1748 { 1749 ksiginfo_t ksi; 1750 1751 AUDIT_ARG_SIGNUM(uap->signum); 1752 AUDIT_ARG_PID(uap->pgid); 1753 if ((u_int)uap->signum > _SIG_MAXSIG) 1754 return (EINVAL); 1755 1756 ksiginfo_init(&ksi); 1757 ksi.ksi_signo = uap->signum; 1758 ksi.ksi_code = SI_USER; 1759 ksi.ksi_pid = td->td_proc->p_pid; 1760 ksi.ksi_uid = td->td_ucred->cr_ruid; 1761 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1762 } 1763 #endif /* COMPAT_43 */ 1764 1765 #ifndef _SYS_SYSPROTO_H_ 1766 struct sigqueue_args { 1767 pid_t pid; 1768 int signum; 1769 /* union sigval */ void *value; 1770 }; 1771 #endif 1772 int 1773 sigqueue(struct thread *td, struct sigqueue_args *uap) 1774 { 1775 ksiginfo_t ksi; 1776 struct proc *p; 1777 int error; 1778 1779 if ((u_int)uap->signum > _SIG_MAXSIG) 1780 return (EINVAL); 1781 1782 /* 1783 * Specification says sigqueue can only send signal to 1784 * single process. 1785 */ 1786 if (uap->pid <= 0) 1787 return (EINVAL); 1788 1789 if ((p = pfind(uap->pid)) == NULL) { 1790 if ((p = zpfind(uap->pid)) == NULL) 1791 return (ESRCH); 1792 } 1793 error = p_cansignal(td, p, uap->signum); 1794 if (error == 0 && uap->signum != 0) { 1795 ksiginfo_init(&ksi); 1796 ksi.ksi_flags = KSI_SIGQ; 1797 ksi.ksi_signo = uap->signum; 1798 ksi.ksi_code = SI_QUEUE; 1799 ksi.ksi_pid = td->td_proc->p_pid; 1800 ksi.ksi_uid = td->td_ucred->cr_ruid; 1801 ksi.ksi_value.sival_ptr = uap->value; 1802 error = pksignal(p, ksi.ksi_signo, &ksi); 1803 } 1804 PROC_UNLOCK(p); 1805 return (error); 1806 } 1807 1808 /* 1809 * Send a signal to a process group. 1810 */ 1811 void 1812 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1813 { 1814 struct pgrp *pgrp; 1815 1816 if (pgid != 0) { 1817 sx_slock(&proctree_lock); 1818 pgrp = pgfind(pgid); 1819 sx_sunlock(&proctree_lock); 1820 if (pgrp != NULL) { 1821 pgsignal(pgrp, sig, 0, ksi); 1822 PGRP_UNLOCK(pgrp); 1823 } 1824 } 1825 } 1826 1827 /* 1828 * Send a signal to a process group. If checktty is 1, 1829 * limit to members which have a controlling terminal. 1830 */ 1831 void 1832 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1833 { 1834 struct proc *p; 1835 1836 if (pgrp) { 1837 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1838 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1839 PROC_LOCK(p); 1840 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1841 pksignal(p, sig, ksi); 1842 PROC_UNLOCK(p); 1843 } 1844 } 1845 } 1846 1847 /* 1848 * Send a signal caused by a trap to the current thread. If it will be 1849 * caught immediately, deliver it with correct code. Otherwise, post it 1850 * normally. 1851 */ 1852 void 1853 trapsignal(struct thread *td, ksiginfo_t *ksi) 1854 { 1855 struct sigacts *ps; 1856 sigset_t mask; 1857 struct proc *p; 1858 int sig; 1859 int code; 1860 1861 p = td->td_proc; 1862 sig = ksi->ksi_signo; 1863 code = ksi->ksi_code; 1864 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1865 1866 PROC_LOCK(p); 1867 ps = p->p_sigacts; 1868 mtx_lock(&ps->ps_mtx); 1869 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1870 !SIGISMEMBER(td->td_sigmask, sig)) { 1871 td->td_ru.ru_nsignals++; 1872 #ifdef KTRACE 1873 if (KTRPOINT(curthread, KTR_PSIG)) 1874 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1875 &td->td_sigmask, code); 1876 #endif 1877 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1878 ksi, &td->td_sigmask); 1879 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1880 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1881 SIGADDSET(mask, sig); 1882 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1883 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1884 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1885 /* 1886 * See kern_sigaction() for origin of this code. 1887 */ 1888 SIGDELSET(ps->ps_sigcatch, sig); 1889 if (sig != SIGCONT && 1890 sigprop(sig) & SA_IGNORE) 1891 SIGADDSET(ps->ps_sigignore, sig); 1892 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1893 } 1894 mtx_unlock(&ps->ps_mtx); 1895 } else { 1896 /* 1897 * Avoid a possible infinite loop if the thread 1898 * masking the signal or process is ignoring the 1899 * signal. 1900 */ 1901 if (kern_forcesigexit && 1902 (SIGISMEMBER(td->td_sigmask, sig) || 1903 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1904 SIGDELSET(td->td_sigmask, sig); 1905 SIGDELSET(ps->ps_sigcatch, sig); 1906 SIGDELSET(ps->ps_sigignore, sig); 1907 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1908 } 1909 mtx_unlock(&ps->ps_mtx); 1910 p->p_code = code; /* XXX for core dump/debugger */ 1911 p->p_sig = sig; /* XXX to verify code */ 1912 tdsendsignal(p, td, sig, ksi); 1913 } 1914 PROC_UNLOCK(p); 1915 } 1916 1917 static struct thread * 1918 sigtd(struct proc *p, int sig, int prop) 1919 { 1920 struct thread *td, *signal_td; 1921 1922 PROC_LOCK_ASSERT(p, MA_OWNED); 1923 1924 /* 1925 * Check if current thread can handle the signal without 1926 * switching context to another thread. 1927 */ 1928 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1929 return (curthread); 1930 signal_td = NULL; 1931 FOREACH_THREAD_IN_PROC(p, td) { 1932 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1933 signal_td = td; 1934 break; 1935 } 1936 } 1937 if (signal_td == NULL) 1938 signal_td = FIRST_THREAD_IN_PROC(p); 1939 return (signal_td); 1940 } 1941 1942 /* 1943 * Send the signal to the process. If the signal has an action, the action 1944 * is usually performed by the target process rather than the caller; we add 1945 * the signal to the set of pending signals for the process. 1946 * 1947 * Exceptions: 1948 * o When a stop signal is sent to a sleeping process that takes the 1949 * default action, the process is stopped without awakening it. 1950 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1951 * regardless of the signal action (eg, blocked or ignored). 1952 * 1953 * Other ignored signals are discarded immediately. 1954 * 1955 * NB: This function may be entered from the debugger via the "kill" DDB 1956 * command. There is little that can be done to mitigate the possibly messy 1957 * side effects of this unwise possibility. 1958 */ 1959 void 1960 psignal(struct proc *p, int sig) 1961 { 1962 ksiginfo_t ksi; 1963 1964 ksiginfo_init(&ksi); 1965 ksi.ksi_signo = sig; 1966 ksi.ksi_code = SI_KERNEL; 1967 (void) tdsendsignal(p, NULL, sig, &ksi); 1968 } 1969 1970 int 1971 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 1972 { 1973 1974 return (tdsendsignal(p, NULL, sig, ksi)); 1975 } 1976 1977 int 1978 psignal_event(struct proc *p, struct sigevent *sigev, ksiginfo_t *ksi) 1979 { 1980 struct thread *td = NULL; 1981 1982 PROC_LOCK_ASSERT(p, MA_OWNED); 1983 1984 KASSERT(!KSI_ONQ(ksi), ("psignal_event: ksi on queue")); 1985 1986 /* 1987 * ksi_code and other fields should be set before 1988 * calling this function. 1989 */ 1990 ksi->ksi_signo = sigev->sigev_signo; 1991 ksi->ksi_value = sigev->sigev_value; 1992 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 1993 td = thread_find(p, sigev->sigev_notify_thread_id); 1994 if (td == NULL) 1995 return (ESRCH); 1996 } 1997 return (tdsendsignal(p, td, ksi->ksi_signo, ksi)); 1998 } 1999 2000 void 2001 tdsignal(struct thread *td, int sig) 2002 { 2003 ksiginfo_t ksi; 2004 2005 ksiginfo_init(&ksi); 2006 ksi.ksi_signo = sig; 2007 ksi.ksi_code = SI_KERNEL; 2008 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2009 } 2010 2011 void 2012 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2013 { 2014 2015 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2016 } 2017 2018 static int 2019 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2020 { 2021 sig_t action; 2022 sigqueue_t *sigqueue; 2023 int prop; 2024 struct sigacts *ps; 2025 int intrval; 2026 int ret = 0; 2027 int wakeup_swapper; 2028 2029 PROC_LOCK_ASSERT(p, MA_OWNED); 2030 2031 if (!_SIG_VALID(sig)) 2032 panic("%s(): invalid signal %d", __func__, sig); 2033 2034 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2035 2036 /* 2037 * IEEE Std 1003.1-2001: return success when killing a zombie. 2038 */ 2039 if (p->p_state == PRS_ZOMBIE) { 2040 if (ksi && (ksi->ksi_flags & KSI_INS)) 2041 ksiginfo_tryfree(ksi); 2042 return (ret); 2043 } 2044 2045 ps = p->p_sigacts; 2046 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2047 prop = sigprop(sig); 2048 2049 if (td == NULL) { 2050 td = sigtd(p, sig, prop); 2051 sigqueue = &p->p_sigqueue; 2052 } else { 2053 KASSERT(td->td_proc == p, ("invalid thread")); 2054 sigqueue = &td->td_sigqueue; 2055 } 2056 2057 SDT_PROBE(proc, kernel, , signal_send, td, p, sig, 0, 0 ); 2058 2059 /* 2060 * If the signal is being ignored, 2061 * then we forget about it immediately. 2062 * (Note: we don't set SIGCONT in ps_sigignore, 2063 * and if it is set to SIG_IGN, 2064 * action will be SIG_DFL here.) 2065 */ 2066 mtx_lock(&ps->ps_mtx); 2067 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2068 SDT_PROBE(proc, kernel, , signal_discard, ps, td, sig, 0, 0 ); 2069 2070 mtx_unlock(&ps->ps_mtx); 2071 if (ksi && (ksi->ksi_flags & KSI_INS)) 2072 ksiginfo_tryfree(ksi); 2073 return (ret); 2074 } 2075 if (SIGISMEMBER(td->td_sigmask, sig)) 2076 action = SIG_HOLD; 2077 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2078 action = SIG_CATCH; 2079 else 2080 action = SIG_DFL; 2081 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2082 intrval = EINTR; 2083 else 2084 intrval = ERESTART; 2085 mtx_unlock(&ps->ps_mtx); 2086 2087 if (prop & SA_CONT) 2088 sigqueue_delete_stopmask_proc(p); 2089 else if (prop & SA_STOP) { 2090 /* 2091 * If sending a tty stop signal to a member of an orphaned 2092 * process group, discard the signal here if the action 2093 * is default; don't stop the process below if sleeping, 2094 * and don't clear any pending SIGCONT. 2095 */ 2096 if ((prop & SA_TTYSTOP) && 2097 (p->p_pgrp->pg_jobc == 0) && 2098 (action == SIG_DFL)) { 2099 if (ksi && (ksi->ksi_flags & KSI_INS)) 2100 ksiginfo_tryfree(ksi); 2101 return (ret); 2102 } 2103 sigqueue_delete_proc(p, SIGCONT); 2104 if (p->p_flag & P_CONTINUED) { 2105 p->p_flag &= ~P_CONTINUED; 2106 PROC_LOCK(p->p_pptr); 2107 sigqueue_take(p->p_ksi); 2108 PROC_UNLOCK(p->p_pptr); 2109 } 2110 } 2111 2112 ret = sigqueue_add(sigqueue, sig, ksi); 2113 if (ret != 0) 2114 return (ret); 2115 signotify(td); 2116 /* 2117 * Defer further processing for signals which are held, 2118 * except that stopped processes must be continued by SIGCONT. 2119 */ 2120 if (action == SIG_HOLD && 2121 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2122 return (ret); 2123 /* 2124 * SIGKILL: Remove procfs STOPEVENTs. 2125 */ 2126 if (sig == SIGKILL) { 2127 /* from procfs_ioctl.c: PIOCBIC */ 2128 p->p_stops = 0; 2129 /* from procfs_ioctl.c: PIOCCONT */ 2130 p->p_step = 0; 2131 wakeup(&p->p_step); 2132 } 2133 /* 2134 * Some signals have a process-wide effect and a per-thread 2135 * component. Most processing occurs when the process next 2136 * tries to cross the user boundary, however there are some 2137 * times when processing needs to be done immediatly, such as 2138 * waking up threads so that they can cross the user boundary. 2139 * We try do the per-process part here. 2140 */ 2141 if (P_SHOULDSTOP(p)) { 2142 /* 2143 * The process is in stopped mode. All the threads should be 2144 * either winding down or already on the suspended queue. 2145 */ 2146 if (p->p_flag & P_TRACED) { 2147 /* 2148 * The traced process is already stopped, 2149 * so no further action is necessary. 2150 * No signal can restart us. 2151 */ 2152 goto out; 2153 } 2154 2155 if (sig == SIGKILL) { 2156 /* 2157 * SIGKILL sets process running. 2158 * It will die elsewhere. 2159 * All threads must be restarted. 2160 */ 2161 p->p_flag &= ~P_STOPPED_SIG; 2162 goto runfast; 2163 } 2164 2165 if (prop & SA_CONT) { 2166 /* 2167 * If SIGCONT is default (or ignored), we continue the 2168 * process but don't leave the signal in sigqueue as 2169 * it has no further action. If SIGCONT is held, we 2170 * continue the process and leave the signal in 2171 * sigqueue. If the process catches SIGCONT, let it 2172 * handle the signal itself. If it isn't waiting on 2173 * an event, it goes back to run state. 2174 * Otherwise, process goes back to sleep state. 2175 */ 2176 p->p_flag &= ~P_STOPPED_SIG; 2177 PROC_SLOCK(p); 2178 if (p->p_numthreads == p->p_suspcount) { 2179 PROC_SUNLOCK(p); 2180 p->p_flag |= P_CONTINUED; 2181 p->p_xstat = SIGCONT; 2182 PROC_LOCK(p->p_pptr); 2183 childproc_continued(p); 2184 PROC_UNLOCK(p->p_pptr); 2185 PROC_SLOCK(p); 2186 } 2187 if (action == SIG_DFL) { 2188 thread_unsuspend(p); 2189 PROC_SUNLOCK(p); 2190 sigqueue_delete(sigqueue, sig); 2191 goto out; 2192 } 2193 if (action == SIG_CATCH) { 2194 /* 2195 * The process wants to catch it so it needs 2196 * to run at least one thread, but which one? 2197 */ 2198 PROC_SUNLOCK(p); 2199 goto runfast; 2200 } 2201 /* 2202 * The signal is not ignored or caught. 2203 */ 2204 thread_unsuspend(p); 2205 PROC_SUNLOCK(p); 2206 goto out; 2207 } 2208 2209 if (prop & SA_STOP) { 2210 /* 2211 * Already stopped, don't need to stop again 2212 * (If we did the shell could get confused). 2213 * Just make sure the signal STOP bit set. 2214 */ 2215 p->p_flag |= P_STOPPED_SIG; 2216 sigqueue_delete(sigqueue, sig); 2217 goto out; 2218 } 2219 2220 /* 2221 * All other kinds of signals: 2222 * If a thread is sleeping interruptibly, simulate a 2223 * wakeup so that when it is continued it will be made 2224 * runnable and can look at the signal. However, don't make 2225 * the PROCESS runnable, leave it stopped. 2226 * It may run a bit until it hits a thread_suspend_check(). 2227 */ 2228 wakeup_swapper = 0; 2229 PROC_SLOCK(p); 2230 thread_lock(td); 2231 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2232 wakeup_swapper = sleepq_abort(td, intrval); 2233 thread_unlock(td); 2234 PROC_SUNLOCK(p); 2235 if (wakeup_swapper) 2236 kick_proc0(); 2237 goto out; 2238 /* 2239 * Mutexes are short lived. Threads waiting on them will 2240 * hit thread_suspend_check() soon. 2241 */ 2242 } else if (p->p_state == PRS_NORMAL) { 2243 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2244 tdsigwakeup(td, sig, action, intrval); 2245 goto out; 2246 } 2247 2248 MPASS(action == SIG_DFL); 2249 2250 if (prop & SA_STOP) { 2251 if (p->p_flag & P_PPWAIT) 2252 goto out; 2253 p->p_flag |= P_STOPPED_SIG; 2254 p->p_xstat = sig; 2255 PROC_SLOCK(p); 2256 sig_suspend_threads(td, p, 1); 2257 if (p->p_numthreads == p->p_suspcount) { 2258 /* 2259 * only thread sending signal to another 2260 * process can reach here, if thread is sending 2261 * signal to its process, because thread does 2262 * not suspend itself here, p_numthreads 2263 * should never be equal to p_suspcount. 2264 */ 2265 thread_stopped(p); 2266 PROC_SUNLOCK(p); 2267 sigqueue_delete_proc(p, p->p_xstat); 2268 } else 2269 PROC_SUNLOCK(p); 2270 goto out; 2271 } 2272 } else { 2273 /* Not in "NORMAL" state. discard the signal. */ 2274 sigqueue_delete(sigqueue, sig); 2275 goto out; 2276 } 2277 2278 /* 2279 * The process is not stopped so we need to apply the signal to all the 2280 * running threads. 2281 */ 2282 runfast: 2283 tdsigwakeup(td, sig, action, intrval); 2284 PROC_SLOCK(p); 2285 thread_unsuspend(p); 2286 PROC_SUNLOCK(p); 2287 out: 2288 /* If we jump here, proc slock should not be owned. */ 2289 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2290 return (ret); 2291 } 2292 2293 /* 2294 * The force of a signal has been directed against a single 2295 * thread. We need to see what we can do about knocking it 2296 * out of any sleep it may be in etc. 2297 */ 2298 static void 2299 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2300 { 2301 struct proc *p = td->td_proc; 2302 register int prop; 2303 int wakeup_swapper; 2304 2305 wakeup_swapper = 0; 2306 PROC_LOCK_ASSERT(p, MA_OWNED); 2307 prop = sigprop(sig); 2308 2309 PROC_SLOCK(p); 2310 thread_lock(td); 2311 /* 2312 * Bring the priority of a thread up if we want it to get 2313 * killed in this lifetime. 2314 */ 2315 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER) 2316 sched_prio(td, PUSER); 2317 if (TD_ON_SLEEPQ(td)) { 2318 /* 2319 * If thread is sleeping uninterruptibly 2320 * we can't interrupt the sleep... the signal will 2321 * be noticed when the process returns through 2322 * trap() or syscall(). 2323 */ 2324 if ((td->td_flags & TDF_SINTR) == 0) 2325 goto out; 2326 /* 2327 * If SIGCONT is default (or ignored) and process is 2328 * asleep, we are finished; the process should not 2329 * be awakened. 2330 */ 2331 if ((prop & SA_CONT) && action == SIG_DFL) { 2332 thread_unlock(td); 2333 PROC_SUNLOCK(p); 2334 sigqueue_delete(&p->p_sigqueue, sig); 2335 /* 2336 * It may be on either list in this state. 2337 * Remove from both for now. 2338 */ 2339 sigqueue_delete(&td->td_sigqueue, sig); 2340 return; 2341 } 2342 2343 /* 2344 * Give low priority threads a better chance to run. 2345 */ 2346 if (td->td_priority > PUSER) 2347 sched_prio(td, PUSER); 2348 2349 wakeup_swapper = sleepq_abort(td, intrval); 2350 } else { 2351 /* 2352 * Other states do nothing with the signal immediately, 2353 * other than kicking ourselves if we are running. 2354 * It will either never be noticed, or noticed very soon. 2355 */ 2356 #ifdef SMP 2357 if (TD_IS_RUNNING(td) && td != curthread) 2358 forward_signal(td); 2359 #endif 2360 } 2361 out: 2362 PROC_SUNLOCK(p); 2363 thread_unlock(td); 2364 if (wakeup_swapper) 2365 kick_proc0(); 2366 } 2367 2368 static void 2369 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2370 { 2371 struct thread *td2; 2372 int wakeup_swapper; 2373 2374 PROC_LOCK_ASSERT(p, MA_OWNED); 2375 PROC_SLOCK_ASSERT(p, MA_OWNED); 2376 2377 wakeup_swapper = 0; 2378 FOREACH_THREAD_IN_PROC(p, td2) { 2379 thread_lock(td2); 2380 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2381 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2382 (td2->td_flags & TDF_SINTR)) { 2383 if (td2->td_flags & TDF_SBDRY) { 2384 if (TD_IS_SUSPENDED(td2)) 2385 wakeup_swapper |= 2386 thread_unsuspend_one(td2); 2387 if (TD_ON_SLEEPQ(td2)) 2388 wakeup_swapper |= 2389 sleepq_abort(td2, ERESTART); 2390 } else if (!TD_IS_SUSPENDED(td2)) { 2391 thread_suspend_one(td2); 2392 } 2393 } else if (!TD_IS_SUSPENDED(td2)) { 2394 if (sending || td != td2) 2395 td2->td_flags |= TDF_ASTPENDING; 2396 #ifdef SMP 2397 if (TD_IS_RUNNING(td2) && td2 != td) 2398 forward_signal(td2); 2399 #endif 2400 } 2401 thread_unlock(td2); 2402 } 2403 if (wakeup_swapper) 2404 kick_proc0(); 2405 } 2406 2407 int 2408 ptracestop(struct thread *td, int sig) 2409 { 2410 struct proc *p = td->td_proc; 2411 2412 PROC_LOCK_ASSERT(p, MA_OWNED); 2413 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2414 &p->p_mtx.lock_object, "Stopping for traced signal"); 2415 2416 td->td_dbgflags |= TDB_XSIG; 2417 td->td_xsig = sig; 2418 PROC_SLOCK(p); 2419 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2420 if (p->p_flag & P_SINGLE_EXIT) { 2421 td->td_dbgflags &= ~TDB_XSIG; 2422 PROC_SUNLOCK(p); 2423 return (sig); 2424 } 2425 /* 2426 * Just make wait() to work, the last stopped thread 2427 * will win. 2428 */ 2429 p->p_xstat = sig; 2430 p->p_xthread = td; 2431 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2432 sig_suspend_threads(td, p, 0); 2433 stopme: 2434 thread_suspend_switch(td); 2435 if (!(p->p_flag & P_TRACED)) { 2436 break; 2437 } 2438 if (td->td_dbgflags & TDB_SUSPEND) { 2439 if (p->p_flag & P_SINGLE_EXIT) 2440 break; 2441 goto stopme; 2442 } 2443 } 2444 PROC_SUNLOCK(p); 2445 return (td->td_xsig); 2446 } 2447 2448 static void 2449 reschedule_signals(struct proc *p, sigset_t block, int flags) 2450 { 2451 struct sigacts *ps; 2452 struct thread *td; 2453 int i; 2454 2455 PROC_LOCK_ASSERT(p, MA_OWNED); 2456 2457 ps = p->p_sigacts; 2458 for (i = 1; !SIGISEMPTY(block); i++) { 2459 if (!SIGISMEMBER(block, i)) 2460 continue; 2461 SIGDELSET(block, i); 2462 if (!SIGISMEMBER(p->p_siglist, i)) 2463 continue; 2464 2465 td = sigtd(p, i, 0); 2466 signotify(td); 2467 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2468 mtx_lock(&ps->ps_mtx); 2469 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, i)) 2470 tdsigwakeup(td, i, SIG_CATCH, 2471 (SIGISMEMBER(ps->ps_sigintr, i) ? EINTR : 2472 ERESTART)); 2473 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2474 mtx_unlock(&ps->ps_mtx); 2475 } 2476 } 2477 2478 void 2479 tdsigcleanup(struct thread *td) 2480 { 2481 struct proc *p; 2482 sigset_t unblocked; 2483 2484 p = td->td_proc; 2485 PROC_LOCK_ASSERT(p, MA_OWNED); 2486 2487 sigqueue_flush(&td->td_sigqueue); 2488 if (p->p_numthreads == 1) 2489 return; 2490 2491 /* 2492 * Since we cannot handle signals, notify signal post code 2493 * about this by filling the sigmask. 2494 * 2495 * Also, if needed, wake up thread(s) that do not block the 2496 * same signals as the exiting thread, since the thread might 2497 * have been selected for delivery and woken up. 2498 */ 2499 SIGFILLSET(unblocked); 2500 SIGSETNAND(unblocked, td->td_sigmask); 2501 SIGFILLSET(td->td_sigmask); 2502 reschedule_signals(p, unblocked, 0); 2503 2504 } 2505 2506 /* 2507 * If the current process has received a signal (should be caught or cause 2508 * termination, should interrupt current syscall), return the signal number. 2509 * Stop signals with default action are processed immediately, then cleared; 2510 * they aren't returned. This is checked after each entry to the system for 2511 * a syscall or trap (though this can usually be done without calling issignal 2512 * by checking the pending signal masks in cursig.) The normal call 2513 * sequence is 2514 * 2515 * while (sig = cursig(curthread)) 2516 * postsig(sig); 2517 */ 2518 static int 2519 issignal(struct thread *td, int stop_allowed) 2520 { 2521 struct proc *p; 2522 struct sigacts *ps; 2523 struct sigqueue *queue; 2524 sigset_t sigpending; 2525 int sig, prop, newsig; 2526 2527 p = td->td_proc; 2528 ps = p->p_sigacts; 2529 mtx_assert(&ps->ps_mtx, MA_OWNED); 2530 PROC_LOCK_ASSERT(p, MA_OWNED); 2531 for (;;) { 2532 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2533 2534 sigpending = td->td_sigqueue.sq_signals; 2535 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2536 SIGSETNAND(sigpending, td->td_sigmask); 2537 2538 if (p->p_flag & P_PPWAIT) 2539 SIG_STOPSIGMASK(sigpending); 2540 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2541 return (0); 2542 sig = sig_ffs(&sigpending); 2543 2544 if (p->p_stops & S_SIG) { 2545 mtx_unlock(&ps->ps_mtx); 2546 stopevent(p, S_SIG, sig); 2547 mtx_lock(&ps->ps_mtx); 2548 } 2549 2550 /* 2551 * We should see pending but ignored signals 2552 * only if P_TRACED was on when they were posted. 2553 */ 2554 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2555 sigqueue_delete(&td->td_sigqueue, sig); 2556 sigqueue_delete(&p->p_sigqueue, sig); 2557 continue; 2558 } 2559 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 2560 /* 2561 * If traced, always stop. 2562 * Remove old signal from queue before the stop. 2563 * XXX shrug off debugger, it causes siginfo to 2564 * be thrown away. 2565 */ 2566 queue = &td->td_sigqueue; 2567 td->td_dbgksi.ksi_signo = 0; 2568 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2569 queue = &p->p_sigqueue; 2570 sigqueue_get(queue, sig, &td->td_dbgksi); 2571 } 2572 2573 mtx_unlock(&ps->ps_mtx); 2574 newsig = ptracestop(td, sig); 2575 mtx_lock(&ps->ps_mtx); 2576 2577 if (sig != newsig) { 2578 2579 /* 2580 * If parent wants us to take the signal, 2581 * then it will leave it in p->p_xstat; 2582 * otherwise we just look for signals again. 2583 */ 2584 if (newsig == 0) 2585 continue; 2586 sig = newsig; 2587 2588 /* 2589 * Put the new signal into td_sigqueue. If the 2590 * signal is being masked, look for other signals. 2591 */ 2592 sigqueue_add(queue, sig, NULL); 2593 if (SIGISMEMBER(td->td_sigmask, sig)) 2594 continue; 2595 signotify(td); 2596 } else { 2597 if (td->td_dbgksi.ksi_signo != 0) { 2598 td->td_dbgksi.ksi_flags |= KSI_HEAD; 2599 if (sigqueue_add(&td->td_sigqueue, sig, 2600 &td->td_dbgksi) != 0) 2601 td->td_dbgksi.ksi_signo = 0; 2602 } 2603 if (td->td_dbgksi.ksi_signo == 0) 2604 sigqueue_add(&td->td_sigqueue, sig, 2605 NULL); 2606 } 2607 2608 /* 2609 * If the traced bit got turned off, go back up 2610 * to the top to rescan signals. This ensures 2611 * that p_sig* and p_sigact are consistent. 2612 */ 2613 if ((p->p_flag & P_TRACED) == 0) 2614 continue; 2615 } 2616 2617 prop = sigprop(sig); 2618 2619 /* 2620 * Decide whether the signal should be returned. 2621 * Return the signal's number, or fall through 2622 * to clear it from the pending mask. 2623 */ 2624 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2625 2626 case (intptr_t)SIG_DFL: 2627 /* 2628 * Don't take default actions on system processes. 2629 */ 2630 if (p->p_pid <= 1) { 2631 #ifdef DIAGNOSTIC 2632 /* 2633 * Are you sure you want to ignore SIGSEGV 2634 * in init? XXX 2635 */ 2636 printf("Process (pid %lu) got signal %d\n", 2637 (u_long)p->p_pid, sig); 2638 #endif 2639 break; /* == ignore */ 2640 } 2641 /* 2642 * If there is a pending stop signal to process 2643 * with default action, stop here, 2644 * then clear the signal. However, 2645 * if process is member of an orphaned 2646 * process group, ignore tty stop signals. 2647 */ 2648 if (prop & SA_STOP) { 2649 if (p->p_flag & P_TRACED || 2650 (p->p_pgrp->pg_jobc == 0 && 2651 prop & SA_TTYSTOP)) 2652 break; /* == ignore */ 2653 2654 /* Ignore, but do not drop the stop signal. */ 2655 if (stop_allowed != SIG_STOP_ALLOWED) 2656 return (sig); 2657 mtx_unlock(&ps->ps_mtx); 2658 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2659 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2660 p->p_flag |= P_STOPPED_SIG; 2661 p->p_xstat = sig; 2662 PROC_SLOCK(p); 2663 sig_suspend_threads(td, p, 0); 2664 thread_suspend_switch(td); 2665 PROC_SUNLOCK(p); 2666 mtx_lock(&ps->ps_mtx); 2667 break; 2668 } else if (prop & SA_IGNORE) { 2669 /* 2670 * Except for SIGCONT, shouldn't get here. 2671 * Default action is to ignore; drop it. 2672 */ 2673 break; /* == ignore */ 2674 } else 2675 return (sig); 2676 /*NOTREACHED*/ 2677 2678 case (intptr_t)SIG_IGN: 2679 /* 2680 * Masking above should prevent us ever trying 2681 * to take action on an ignored signal other 2682 * than SIGCONT, unless process is traced. 2683 */ 2684 if ((prop & SA_CONT) == 0 && 2685 (p->p_flag & P_TRACED) == 0) 2686 printf("issignal\n"); 2687 break; /* == ignore */ 2688 2689 default: 2690 /* 2691 * This signal has an action, let 2692 * postsig() process it. 2693 */ 2694 return (sig); 2695 } 2696 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2697 sigqueue_delete(&p->p_sigqueue, sig); 2698 } 2699 /* NOTREACHED */ 2700 } 2701 2702 void 2703 thread_stopped(struct proc *p) 2704 { 2705 int n; 2706 2707 PROC_LOCK_ASSERT(p, MA_OWNED); 2708 PROC_SLOCK_ASSERT(p, MA_OWNED); 2709 n = p->p_suspcount; 2710 if (p == curproc) 2711 n++; 2712 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2713 PROC_SUNLOCK(p); 2714 p->p_flag &= ~P_WAITED; 2715 PROC_LOCK(p->p_pptr); 2716 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2717 CLD_TRAPPED : CLD_STOPPED); 2718 PROC_UNLOCK(p->p_pptr); 2719 PROC_SLOCK(p); 2720 } 2721 } 2722 2723 /* 2724 * Take the action for the specified signal 2725 * from the current set of pending signals. 2726 */ 2727 int 2728 postsig(sig) 2729 register int sig; 2730 { 2731 struct thread *td = curthread; 2732 register struct proc *p = td->td_proc; 2733 struct sigacts *ps; 2734 sig_t action; 2735 ksiginfo_t ksi; 2736 sigset_t returnmask, mask; 2737 2738 KASSERT(sig != 0, ("postsig")); 2739 2740 PROC_LOCK_ASSERT(p, MA_OWNED); 2741 ps = p->p_sigacts; 2742 mtx_assert(&ps->ps_mtx, MA_OWNED); 2743 ksiginfo_init(&ksi); 2744 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2745 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2746 return (0); 2747 ksi.ksi_signo = sig; 2748 if (ksi.ksi_code == SI_TIMER) 2749 itimer_accept(p, ksi.ksi_timerid, &ksi); 2750 action = ps->ps_sigact[_SIG_IDX(sig)]; 2751 #ifdef KTRACE 2752 if (KTRPOINT(td, KTR_PSIG)) 2753 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2754 &td->td_oldsigmask : &td->td_sigmask, 0); 2755 #endif 2756 if (p->p_stops & S_SIG) { 2757 mtx_unlock(&ps->ps_mtx); 2758 stopevent(p, S_SIG, sig); 2759 mtx_lock(&ps->ps_mtx); 2760 } 2761 2762 if (action == SIG_DFL) { 2763 /* 2764 * Default action, where the default is to kill 2765 * the process. (Other cases were ignored above.) 2766 */ 2767 mtx_unlock(&ps->ps_mtx); 2768 sigexit(td, sig); 2769 /* NOTREACHED */ 2770 } else { 2771 /* 2772 * If we get here, the signal must be caught. 2773 */ 2774 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2775 ("postsig action")); 2776 /* 2777 * Set the new mask value and also defer further 2778 * occurrences of this signal. 2779 * 2780 * Special case: user has done a sigsuspend. Here the 2781 * current mask is not of interest, but rather the 2782 * mask from before the sigsuspend is what we want 2783 * restored after the signal processing is completed. 2784 */ 2785 if (td->td_pflags & TDP_OLDMASK) { 2786 returnmask = td->td_oldsigmask; 2787 td->td_pflags &= ~TDP_OLDMASK; 2788 } else 2789 returnmask = td->td_sigmask; 2790 2791 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2792 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2793 SIGADDSET(mask, sig); 2794 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2795 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2796 2797 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2798 /* 2799 * See kern_sigaction() for origin of this code. 2800 */ 2801 SIGDELSET(ps->ps_sigcatch, sig); 2802 if (sig != SIGCONT && 2803 sigprop(sig) & SA_IGNORE) 2804 SIGADDSET(ps->ps_sigignore, sig); 2805 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2806 } 2807 td->td_ru.ru_nsignals++; 2808 if (p->p_sig == sig) { 2809 p->p_code = 0; 2810 p->p_sig = 0; 2811 } 2812 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2813 } 2814 return (1); 2815 } 2816 2817 /* 2818 * Kill the current process for stated reason. 2819 */ 2820 void 2821 killproc(p, why) 2822 struct proc *p; 2823 char *why; 2824 { 2825 2826 PROC_LOCK_ASSERT(p, MA_OWNED); 2827 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2828 p, p->p_pid, p->p_comm); 2829 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2830 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2831 p->p_flag |= P_WKILLED; 2832 psignal(p, SIGKILL); 2833 } 2834 2835 /* 2836 * Force the current process to exit with the specified signal, dumping core 2837 * if appropriate. We bypass the normal tests for masked and caught signals, 2838 * allowing unrecoverable failures to terminate the process without changing 2839 * signal state. Mark the accounting record with the signal termination. 2840 * If dumping core, save the signal number for the debugger. Calls exit and 2841 * does not return. 2842 */ 2843 void 2844 sigexit(td, sig) 2845 struct thread *td; 2846 int sig; 2847 { 2848 struct proc *p = td->td_proc; 2849 2850 PROC_LOCK_ASSERT(p, MA_OWNED); 2851 p->p_acflag |= AXSIG; 2852 /* 2853 * We must be single-threading to generate a core dump. This 2854 * ensures that the registers in the core file are up-to-date. 2855 * Also, the ELF dump handler assumes that the thread list doesn't 2856 * change out from under it. 2857 * 2858 * XXX If another thread attempts to single-thread before us 2859 * (e.g. via fork()), we won't get a dump at all. 2860 */ 2861 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2862 p->p_sig = sig; 2863 /* 2864 * Log signals which would cause core dumps 2865 * (Log as LOG_INFO to appease those who don't want 2866 * these messages.) 2867 * XXX : Todo, as well as euid, write out ruid too 2868 * Note that coredump() drops proc lock. 2869 */ 2870 if (coredump(td) == 0) 2871 sig |= WCOREFLAG; 2872 if (kern_logsigexit) 2873 log(LOG_INFO, 2874 "pid %d (%s), uid %d: exited on signal %d%s\n", 2875 p->p_pid, p->p_comm, 2876 td->td_ucred ? td->td_ucred->cr_uid : -1, 2877 sig &~ WCOREFLAG, 2878 sig & WCOREFLAG ? " (core dumped)" : ""); 2879 } else 2880 PROC_UNLOCK(p); 2881 exit1(td, W_EXITCODE(0, sig)); 2882 /* NOTREACHED */ 2883 } 2884 2885 /* 2886 * Send queued SIGCHLD to parent when child process's state 2887 * is changed. 2888 */ 2889 static void 2890 sigparent(struct proc *p, int reason, int status) 2891 { 2892 PROC_LOCK_ASSERT(p, MA_OWNED); 2893 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2894 2895 if (p->p_ksi != NULL) { 2896 p->p_ksi->ksi_signo = SIGCHLD; 2897 p->p_ksi->ksi_code = reason; 2898 p->p_ksi->ksi_status = status; 2899 p->p_ksi->ksi_pid = p->p_pid; 2900 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2901 if (KSI_ONQ(p->p_ksi)) 2902 return; 2903 } 2904 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 2905 } 2906 2907 static void 2908 childproc_jobstate(struct proc *p, int reason, int status) 2909 { 2910 struct sigacts *ps; 2911 2912 PROC_LOCK_ASSERT(p, MA_OWNED); 2913 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2914 2915 /* 2916 * Wake up parent sleeping in kern_wait(), also send 2917 * SIGCHLD to parent, but SIGCHLD does not guarantee 2918 * that parent will awake, because parent may masked 2919 * the signal. 2920 */ 2921 p->p_pptr->p_flag |= P_STATCHILD; 2922 wakeup(p->p_pptr); 2923 2924 ps = p->p_pptr->p_sigacts; 2925 mtx_lock(&ps->ps_mtx); 2926 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2927 mtx_unlock(&ps->ps_mtx); 2928 sigparent(p, reason, status); 2929 } else 2930 mtx_unlock(&ps->ps_mtx); 2931 } 2932 2933 void 2934 childproc_stopped(struct proc *p, int reason) 2935 { 2936 childproc_jobstate(p, reason, p->p_xstat); 2937 } 2938 2939 void 2940 childproc_continued(struct proc *p) 2941 { 2942 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 2943 } 2944 2945 void 2946 childproc_exited(struct proc *p) 2947 { 2948 int reason; 2949 int status = p->p_xstat; /* convert to int */ 2950 2951 reason = CLD_EXITED; 2952 if (WCOREDUMP(status)) 2953 reason = CLD_DUMPED; 2954 else if (WIFSIGNALED(status)) 2955 reason = CLD_KILLED; 2956 /* 2957 * XXX avoid calling wakeup(p->p_pptr), the work is 2958 * done in exit1(). 2959 */ 2960 sigparent(p, reason, status); 2961 } 2962 2963 /* 2964 * We only have 1 character for the core count in the format 2965 * string, so the range will be 0-9 2966 */ 2967 #define MAX_NUM_CORES 10 2968 static int num_cores = 5; 2969 2970 static int 2971 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 2972 { 2973 int error; 2974 int new_val; 2975 2976 new_val = num_cores; 2977 error = sysctl_handle_int(oidp, &new_val, 0, req); 2978 if (error != 0 || req->newptr == NULL) 2979 return (error); 2980 if (new_val > MAX_NUM_CORES) 2981 new_val = MAX_NUM_CORES; 2982 if (new_val < 0) 2983 new_val = 0; 2984 num_cores = new_val; 2985 return (0); 2986 } 2987 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 2988 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 2989 2990 #if defined(COMPRESS_USER_CORES) 2991 int compress_user_cores = 1; 2992 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RW, 2993 &compress_user_cores, 0, ""); 2994 2995 int compress_user_cores_gzlevel = -1; /* default level */ 2996 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RW, 2997 &compress_user_cores_gzlevel, -1, "user core gz compression level"); 2998 2999 #define GZ_SUFFIX ".gz" 3000 #define GZ_SUFFIX_LEN 3 3001 #endif 3002 3003 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3004 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 3005 sizeof(corefilename), "process corefile name format string"); 3006 3007 /* 3008 * expand_name(name, uid, pid, td, compress) 3009 * Expand the name described in corefilename, using name, uid, and pid. 3010 * corefilename is a printf-like string, with three format specifiers: 3011 * %N name of process ("name") 3012 * %P process id (pid) 3013 * %U user id (uid) 3014 * For example, "%N.core" is the default; they can be disabled completely 3015 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3016 * This is controlled by the sysctl variable kern.corefile (see above). 3017 */ 3018 static char * 3019 expand_name(const char *name, uid_t uid, pid_t pid, struct thread *td, 3020 int compress) 3021 { 3022 struct sbuf sb; 3023 const char *format; 3024 char *temp; 3025 size_t i; 3026 int indexpos; 3027 char *hostname; 3028 3029 hostname = NULL; 3030 format = corefilename; 3031 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 3032 if (temp == NULL) 3033 return (NULL); 3034 indexpos = -1; 3035 (void)sbuf_new(&sb, temp, MAXPATHLEN, SBUF_FIXEDLEN); 3036 for (i = 0; format[i]; i++) { 3037 switch (format[i]) { 3038 case '%': /* Format character */ 3039 i++; 3040 switch (format[i]) { 3041 case '%': 3042 sbuf_putc(&sb, '%'); 3043 break; 3044 case 'H': /* hostname */ 3045 if (hostname == NULL) { 3046 hostname = malloc(MAXHOSTNAMELEN, 3047 M_TEMP, M_NOWAIT); 3048 if (hostname == NULL) { 3049 log(LOG_ERR, 3050 "pid %ld (%s), uid (%lu): " 3051 "unable to alloc memory " 3052 "for corefile hostname\n", 3053 (long)pid, name, 3054 (u_long)uid); 3055 goto nomem; 3056 } 3057 } 3058 getcredhostname(td->td_ucred, hostname, 3059 MAXHOSTNAMELEN); 3060 sbuf_printf(&sb, "%s", hostname); 3061 break; 3062 case 'I': /* autoincrementing index */ 3063 sbuf_printf(&sb, "0"); 3064 indexpos = sbuf_len(&sb) - 1; 3065 break; 3066 case 'N': /* process name */ 3067 sbuf_printf(&sb, "%s", name); 3068 break; 3069 case 'P': /* process id */ 3070 sbuf_printf(&sb, "%u", pid); 3071 break; 3072 case 'U': /* user id */ 3073 sbuf_printf(&sb, "%u", uid); 3074 break; 3075 default: 3076 log(LOG_ERR, 3077 "Unknown format character %c in " 3078 "corename `%s'\n", format[i], format); 3079 } 3080 break; 3081 default: 3082 sbuf_putc(&sb, format[i]); 3083 } 3084 } 3085 free(hostname, M_TEMP); 3086 #ifdef COMPRESS_USER_CORES 3087 if (compress) { 3088 sbuf_printf(&sb, GZ_SUFFIX); 3089 } 3090 #endif 3091 if (sbuf_overflowed(&sb)) { 3092 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3093 "long\n", (long)pid, name, (u_long)uid); 3094 nomem: 3095 sbuf_delete(&sb); 3096 free(temp, M_TEMP); 3097 return (NULL); 3098 } 3099 sbuf_finish(&sb); 3100 sbuf_delete(&sb); 3101 3102 /* 3103 * If the core format has a %I in it, then we need to check 3104 * for existing corefiles before returning a name. 3105 * To do this we iterate over 0..num_cores to find a 3106 * non-existing core file name to use. 3107 */ 3108 if (indexpos != -1) { 3109 struct nameidata nd; 3110 int error, n; 3111 int flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3112 int cmode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP; 3113 int vfslocked; 3114 3115 for (n = 0; n < num_cores; n++) { 3116 temp[indexpos] = '0' + n; 3117 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, 3118 temp, td); 3119 error = vn_open(&nd, &flags, cmode, NULL); 3120 if (error) { 3121 if (error == EEXIST) { 3122 continue; 3123 } 3124 log(LOG_ERR, 3125 "pid %d (%s), uid (%u): Path `%s' failed " 3126 "on initial open test, error = %d\n", 3127 pid, name, uid, temp, error); 3128 free(temp, M_TEMP); 3129 return (NULL); 3130 } 3131 vfslocked = NDHASGIANT(&nd); 3132 NDFREE(&nd, NDF_ONLY_PNBUF); 3133 VOP_UNLOCK(nd.ni_vp, 0); 3134 error = vn_close(nd.ni_vp, FWRITE, td->td_ucred, td); 3135 VFS_UNLOCK_GIANT(vfslocked); 3136 if (error) { 3137 log(LOG_ERR, 3138 "pid %d (%s), uid (%u): Path `%s' failed " 3139 "on close after initial open test, " 3140 "error = %d\n", 3141 pid, name, uid, temp, error); 3142 free(temp, M_TEMP); 3143 return (NULL); 3144 } 3145 break; 3146 } 3147 } 3148 return (temp); 3149 } 3150 3151 /* 3152 * Dump a process' core. The main routine does some 3153 * policy checking, and creates the name of the coredump; 3154 * then it passes on a vnode and a size limit to the process-specific 3155 * coredump routine if there is one; if there _is not_ one, it returns 3156 * ENOSYS; otherwise it returns the error from the process-specific routine. 3157 */ 3158 3159 static int 3160 coredump(struct thread *td) 3161 { 3162 struct proc *p = td->td_proc; 3163 register struct vnode *vp; 3164 register struct ucred *cred = td->td_ucred; 3165 struct flock lf; 3166 struct nameidata nd; 3167 struct vattr vattr; 3168 int error, error1, flags, locked; 3169 struct mount *mp; 3170 char *name; /* name of corefile */ 3171 off_t limit; 3172 int vfslocked; 3173 int compress; 3174 3175 #ifdef COMPRESS_USER_CORES 3176 compress = compress_user_cores; 3177 #else 3178 compress = 0; 3179 #endif 3180 PROC_LOCK_ASSERT(p, MA_OWNED); 3181 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3182 _STOPEVENT(p, S_CORE, 0); 3183 3184 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid, td, 3185 compress); 3186 if (name == NULL) { 3187 PROC_UNLOCK(p); 3188 #ifdef AUDIT 3189 audit_proc_coredump(td, NULL, EINVAL); 3190 #endif 3191 return (EINVAL); 3192 } 3193 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 3194 PROC_UNLOCK(p); 3195 #ifdef AUDIT 3196 audit_proc_coredump(td, name, EFAULT); 3197 #endif 3198 free(name, M_TEMP); 3199 return (EFAULT); 3200 } 3201 3202 /* 3203 * Note that the bulk of limit checking is done after 3204 * the corefile is created. The exception is if the limit 3205 * for corefiles is 0, in which case we don't bother 3206 * creating the corefile at all. This layout means that 3207 * a corefile is truncated instead of not being created, 3208 * if it is larger than the limit. 3209 */ 3210 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3211 PROC_UNLOCK(p); 3212 if (limit == 0) { 3213 #ifdef AUDIT 3214 audit_proc_coredump(td, name, EFBIG); 3215 #endif 3216 free(name, M_TEMP); 3217 return (EFBIG); 3218 } 3219 3220 restart: 3221 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, name, td); 3222 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3223 error = vn_open_cred(&nd, &flags, S_IRUSR | S_IWUSR, VN_OPEN_NOAUDIT, 3224 cred, NULL); 3225 if (error) { 3226 #ifdef AUDIT 3227 audit_proc_coredump(td, name, error); 3228 #endif 3229 free(name, M_TEMP); 3230 return (error); 3231 } 3232 vfslocked = NDHASGIANT(&nd); 3233 NDFREE(&nd, NDF_ONLY_PNBUF); 3234 vp = nd.ni_vp; 3235 3236 /* Don't dump to non-regular files or files with links. */ 3237 if (vp->v_type != VREG || 3238 VOP_GETATTR(vp, &vattr, cred) || vattr.va_nlink != 1) { 3239 VOP_UNLOCK(vp, 0); 3240 error = EFAULT; 3241 goto close; 3242 } 3243 3244 VOP_UNLOCK(vp, 0); 3245 lf.l_whence = SEEK_SET; 3246 lf.l_start = 0; 3247 lf.l_len = 0; 3248 lf.l_type = F_WRLCK; 3249 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3250 3251 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3252 lf.l_type = F_UNLCK; 3253 if (locked) 3254 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3255 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3256 goto out; 3257 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3258 goto out; 3259 VFS_UNLOCK_GIANT(vfslocked); 3260 goto restart; 3261 } 3262 3263 VATTR_NULL(&vattr); 3264 vattr.va_size = 0; 3265 if (set_core_nodump_flag) 3266 vattr.va_flags = UF_NODUMP; 3267 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3268 VOP_SETATTR(vp, &vattr, cred); 3269 VOP_UNLOCK(vp, 0); 3270 vn_finished_write(mp); 3271 PROC_LOCK(p); 3272 p->p_acflag |= ACORE; 3273 PROC_UNLOCK(p); 3274 3275 error = p->p_sysent->sv_coredump ? 3276 p->p_sysent->sv_coredump(td, vp, limit, compress ? IMGACT_CORE_COMPRESS : 0) : 3277 ENOSYS; 3278 3279 if (locked) { 3280 lf.l_type = F_UNLCK; 3281 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3282 } 3283 close: 3284 error1 = vn_close(vp, FWRITE, cred, td); 3285 if (error == 0) 3286 error = error1; 3287 out: 3288 #ifdef AUDIT 3289 audit_proc_coredump(td, name, error); 3290 #endif 3291 free(name, M_TEMP); 3292 VFS_UNLOCK_GIANT(vfslocked); 3293 return (error); 3294 } 3295 3296 /* 3297 * Nonexistent system call-- signal process (may want to handle it). Flag 3298 * error in case process won't see signal immediately (blocked or ignored). 3299 */ 3300 #ifndef _SYS_SYSPROTO_H_ 3301 struct nosys_args { 3302 int dummy; 3303 }; 3304 #endif 3305 /* ARGSUSED */ 3306 int 3307 nosys(td, args) 3308 struct thread *td; 3309 struct nosys_args *args; 3310 { 3311 struct proc *p = td->td_proc; 3312 3313 PROC_LOCK(p); 3314 psignal(p, SIGSYS); 3315 PROC_UNLOCK(p); 3316 return (ENOSYS); 3317 } 3318 3319 /* 3320 * Send a SIGIO or SIGURG signal to a process or process group using stored 3321 * credentials rather than those of the current process. 3322 */ 3323 void 3324 pgsigio(sigiop, sig, checkctty) 3325 struct sigio **sigiop; 3326 int sig, checkctty; 3327 { 3328 ksiginfo_t ksi; 3329 struct sigio *sigio; 3330 3331 ksiginfo_init(&ksi); 3332 ksi.ksi_signo = sig; 3333 ksi.ksi_code = SI_KERNEL; 3334 3335 SIGIO_LOCK(); 3336 sigio = *sigiop; 3337 if (sigio == NULL) { 3338 SIGIO_UNLOCK(); 3339 return; 3340 } 3341 if (sigio->sio_pgid > 0) { 3342 PROC_LOCK(sigio->sio_proc); 3343 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3344 psignal(sigio->sio_proc, sig); 3345 PROC_UNLOCK(sigio->sio_proc); 3346 } else if (sigio->sio_pgid < 0) { 3347 struct proc *p; 3348 3349 PGRP_LOCK(sigio->sio_pgrp); 3350 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3351 PROC_LOCK(p); 3352 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3353 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3354 psignal(p, sig); 3355 PROC_UNLOCK(p); 3356 } 3357 PGRP_UNLOCK(sigio->sio_pgrp); 3358 } 3359 SIGIO_UNLOCK(); 3360 } 3361 3362 static int 3363 filt_sigattach(struct knote *kn) 3364 { 3365 struct proc *p = curproc; 3366 3367 kn->kn_ptr.p_proc = p; 3368 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3369 3370 knlist_add(&p->p_klist, kn, 0); 3371 3372 return (0); 3373 } 3374 3375 static void 3376 filt_sigdetach(struct knote *kn) 3377 { 3378 struct proc *p = kn->kn_ptr.p_proc; 3379 3380 knlist_remove(&p->p_klist, kn, 0); 3381 } 3382 3383 /* 3384 * signal knotes are shared with proc knotes, so we apply a mask to 3385 * the hint in order to differentiate them from process hints. This 3386 * could be avoided by using a signal-specific knote list, but probably 3387 * isn't worth the trouble. 3388 */ 3389 static int 3390 filt_signal(struct knote *kn, long hint) 3391 { 3392 3393 if (hint & NOTE_SIGNAL) { 3394 hint &= ~NOTE_SIGNAL; 3395 3396 if (kn->kn_id == hint) 3397 kn->kn_data++; 3398 } 3399 return (kn->kn_data != 0); 3400 } 3401 3402 struct sigacts * 3403 sigacts_alloc(void) 3404 { 3405 struct sigacts *ps; 3406 3407 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3408 ps->ps_refcnt = 1; 3409 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3410 return (ps); 3411 } 3412 3413 void 3414 sigacts_free(struct sigacts *ps) 3415 { 3416 3417 mtx_lock(&ps->ps_mtx); 3418 ps->ps_refcnt--; 3419 if (ps->ps_refcnt == 0) { 3420 mtx_destroy(&ps->ps_mtx); 3421 free(ps, M_SUBPROC); 3422 } else 3423 mtx_unlock(&ps->ps_mtx); 3424 } 3425 3426 struct sigacts * 3427 sigacts_hold(struct sigacts *ps) 3428 { 3429 mtx_lock(&ps->ps_mtx); 3430 ps->ps_refcnt++; 3431 mtx_unlock(&ps->ps_mtx); 3432 return (ps); 3433 } 3434 3435 void 3436 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3437 { 3438 3439 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3440 mtx_lock(&src->ps_mtx); 3441 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3442 mtx_unlock(&src->ps_mtx); 3443 } 3444 3445 int 3446 sigacts_shared(struct sigacts *ps) 3447 { 3448 int shared; 3449 3450 mtx_lock(&ps->ps_mtx); 3451 shared = ps->ps_refcnt > 1; 3452 mtx_unlock(&ps->ps_mtx); 3453 return (shared); 3454 } 3455