1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/ctype.h> 46 #include <sys/systm.h> 47 #include <sys/signalvar.h> 48 #include <sys/vnode.h> 49 #include <sys/acct.h> 50 #include <sys/bus.h> 51 #include <sys/capsicum.h> 52 #include <sys/compressor.h> 53 #include <sys/condvar.h> 54 #include <sys/event.h> 55 #include <sys/fcntl.h> 56 #include <sys/imgact.h> 57 #include <sys/kernel.h> 58 #include <sys/ktr.h> 59 #include <sys/ktrace.h> 60 #include <sys/limits.h> 61 #include <sys/lock.h> 62 #include <sys/malloc.h> 63 #include <sys/mutex.h> 64 #include <sys/refcount.h> 65 #include <sys/namei.h> 66 #include <sys/proc.h> 67 #include <sys/procdesc.h> 68 #include <sys/ptrace.h> 69 #include <sys/posix4.h> 70 #include <sys/pioctl.h> 71 #include <sys/racct.h> 72 #include <sys/resourcevar.h> 73 #include <sys/sdt.h> 74 #include <sys/sbuf.h> 75 #include <sys/sleepqueue.h> 76 #include <sys/smp.h> 77 #include <sys/stat.h> 78 #include <sys/sx.h> 79 #include <sys/syscallsubr.h> 80 #include <sys/sysctl.h> 81 #include <sys/sysent.h> 82 #include <sys/syslog.h> 83 #include <sys/sysproto.h> 84 #include <sys/timers.h> 85 #include <sys/unistd.h> 86 #include <sys/wait.h> 87 #include <vm/vm.h> 88 #include <vm/vm_extern.h> 89 #include <vm/uma.h> 90 91 #include <sys/jail.h> 92 93 #include <machine/cpu.h> 94 95 #include <security/audit/audit.h> 96 97 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 98 99 SDT_PROVIDER_DECLARE(proc); 100 SDT_PROBE_DEFINE3(proc, , , signal__send, 101 "struct thread *", "struct proc *", "int"); 102 SDT_PROBE_DEFINE2(proc, , , signal__clear, 103 "int", "ksiginfo_t *"); 104 SDT_PROBE_DEFINE3(proc, , , signal__discard, 105 "struct thread *", "struct proc *", "int"); 106 107 static int coredump(struct thread *); 108 static int killpg1(struct thread *td, int sig, int pgid, int all, 109 ksiginfo_t *ksi); 110 static int issignal(struct thread *td); 111 static int sigprop(int sig); 112 static void tdsigwakeup(struct thread *, int, sig_t, int); 113 static int 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 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 138 "POSIX real time signal"); 139 140 static int max_pending_per_proc = 128; 141 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 142 &max_pending_per_proc, 0, "Max pending signals per proc"); 143 144 static int preallocate_siginfo = 1024; 145 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 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 static int kern_lognosys = 0; 157 SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 158 "Log invalid syscalls"); 159 160 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 161 162 /* 163 * Policy -- Can ucred cr1 send SIGIO to process cr2? 164 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 165 * in the right situations. 166 */ 167 #define CANSIGIO(cr1, cr2) \ 168 ((cr1)->cr_uid == 0 || \ 169 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 170 (cr1)->cr_uid == (cr2)->cr_ruid || \ 171 (cr1)->cr_ruid == (cr2)->cr_uid || \ 172 (cr1)->cr_uid == (cr2)->cr_uid) 173 174 static int sugid_coredump; 175 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 176 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 177 178 static int capmode_coredump; 179 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 180 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 181 182 static int do_coredump = 1; 183 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 184 &do_coredump, 0, "Enable/Disable coredumps"); 185 186 static int set_core_nodump_flag = 0; 187 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 188 0, "Enable setting the NODUMP flag on coredump files"); 189 190 static int coredump_devctl = 0; 191 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 192 0, "Generate a devctl notification when processes coredump"); 193 194 /* 195 * Signal properties and actions. 196 * The array below categorizes the signals and their default actions 197 * according to the following properties: 198 */ 199 #define SIGPROP_KILL 0x01 /* terminates process by default */ 200 #define SIGPROP_CORE 0x02 /* ditto and coredumps */ 201 #define SIGPROP_STOP 0x04 /* suspend process */ 202 #define SIGPROP_TTYSTOP 0x08 /* ditto, from tty */ 203 #define SIGPROP_IGNORE 0x10 /* ignore by default */ 204 #define SIGPROP_CONT 0x20 /* continue if suspended */ 205 #define SIGPROP_CANTMASK 0x40 /* non-maskable, catchable */ 206 207 static int sigproptbl[NSIG] = { 208 [SIGHUP] = SIGPROP_KILL, 209 [SIGINT] = SIGPROP_KILL, 210 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE, 211 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE, 212 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE, 213 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE, 214 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE, 215 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE, 216 [SIGKILL] = SIGPROP_KILL, 217 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE, 218 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE, 219 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE, 220 [SIGPIPE] = SIGPROP_KILL, 221 [SIGALRM] = SIGPROP_KILL, 222 [SIGTERM] = SIGPROP_KILL, 223 [SIGURG] = SIGPROP_IGNORE, 224 [SIGSTOP] = SIGPROP_STOP, 225 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP, 226 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT, 227 [SIGCHLD] = SIGPROP_IGNORE, 228 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP, 229 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP, 230 [SIGIO] = SIGPROP_IGNORE, 231 [SIGXCPU] = SIGPROP_KILL, 232 [SIGXFSZ] = SIGPROP_KILL, 233 [SIGVTALRM] = SIGPROP_KILL, 234 [SIGPROF] = SIGPROP_KILL, 235 [SIGWINCH] = SIGPROP_IGNORE, 236 [SIGINFO] = SIGPROP_IGNORE, 237 [SIGUSR1] = SIGPROP_KILL, 238 [SIGUSR2] = SIGPROP_KILL, 239 }; 240 241 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 242 243 static void 244 sigqueue_start(void) 245 { 246 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 247 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 248 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 249 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 250 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 251 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 252 } 253 254 ksiginfo_t * 255 ksiginfo_alloc(int wait) 256 { 257 int flags; 258 259 flags = M_ZERO; 260 if (! wait) 261 flags |= M_NOWAIT; 262 if (ksiginfo_zone != NULL) 263 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 264 return (NULL); 265 } 266 267 void 268 ksiginfo_free(ksiginfo_t *ksi) 269 { 270 uma_zfree(ksiginfo_zone, ksi); 271 } 272 273 static __inline int 274 ksiginfo_tryfree(ksiginfo_t *ksi) 275 { 276 if (!(ksi->ksi_flags & KSI_EXT)) { 277 uma_zfree(ksiginfo_zone, ksi); 278 return (1); 279 } 280 return (0); 281 } 282 283 void 284 sigqueue_init(sigqueue_t *list, struct proc *p) 285 { 286 SIGEMPTYSET(list->sq_signals); 287 SIGEMPTYSET(list->sq_kill); 288 SIGEMPTYSET(list->sq_ptrace); 289 TAILQ_INIT(&list->sq_list); 290 list->sq_proc = p; 291 list->sq_flags = SQ_INIT; 292 } 293 294 /* 295 * Get a signal's ksiginfo. 296 * Return: 297 * 0 - signal not found 298 * others - signal number 299 */ 300 static int 301 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 302 { 303 struct proc *p = sq->sq_proc; 304 struct ksiginfo *ksi, *next; 305 int count = 0; 306 307 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 308 309 if (!SIGISMEMBER(sq->sq_signals, signo)) 310 return (0); 311 312 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 313 count++; 314 SIGDELSET(sq->sq_ptrace, signo); 315 si->ksi_flags |= KSI_PTRACE; 316 } 317 if (SIGISMEMBER(sq->sq_kill, signo)) { 318 count++; 319 if (count == 1) 320 SIGDELSET(sq->sq_kill, signo); 321 } 322 323 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 324 if (ksi->ksi_signo == signo) { 325 if (count == 0) { 326 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 327 ksi->ksi_sigq = NULL; 328 ksiginfo_copy(ksi, si); 329 if (ksiginfo_tryfree(ksi) && p != NULL) 330 p->p_pendingcnt--; 331 } 332 if (++count > 1) 333 break; 334 } 335 } 336 337 if (count <= 1) 338 SIGDELSET(sq->sq_signals, signo); 339 si->ksi_signo = signo; 340 return (signo); 341 } 342 343 void 344 sigqueue_take(ksiginfo_t *ksi) 345 { 346 struct ksiginfo *kp; 347 struct proc *p; 348 sigqueue_t *sq; 349 350 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 351 return; 352 353 p = sq->sq_proc; 354 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 355 ksi->ksi_sigq = NULL; 356 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 357 p->p_pendingcnt--; 358 359 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 360 kp = TAILQ_NEXT(kp, ksi_link)) { 361 if (kp->ksi_signo == ksi->ksi_signo) 362 break; 363 } 364 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 365 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 366 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 367 } 368 369 static int 370 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 371 { 372 struct proc *p = sq->sq_proc; 373 struct ksiginfo *ksi; 374 int ret = 0; 375 376 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 377 378 /* 379 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 380 * for these signals. 381 */ 382 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 383 SIGADDSET(sq->sq_kill, signo); 384 goto out_set_bit; 385 } 386 387 /* directly insert the ksi, don't copy it */ 388 if (si->ksi_flags & KSI_INS) { 389 if (si->ksi_flags & KSI_HEAD) 390 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 391 else 392 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 393 si->ksi_sigq = sq; 394 goto out_set_bit; 395 } 396 397 if (__predict_false(ksiginfo_zone == NULL)) { 398 SIGADDSET(sq->sq_kill, signo); 399 goto out_set_bit; 400 } 401 402 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 403 signal_overflow++; 404 ret = EAGAIN; 405 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 406 signal_alloc_fail++; 407 ret = EAGAIN; 408 } else { 409 if (p != NULL) 410 p->p_pendingcnt++; 411 ksiginfo_copy(si, ksi); 412 ksi->ksi_signo = signo; 413 if (si->ksi_flags & KSI_HEAD) 414 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 415 else 416 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 417 ksi->ksi_sigq = sq; 418 } 419 420 if (ret != 0) { 421 if ((si->ksi_flags & KSI_PTRACE) != 0) { 422 SIGADDSET(sq->sq_ptrace, signo); 423 ret = 0; 424 goto out_set_bit; 425 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 426 (si->ksi_flags & KSI_SIGQ) == 0) { 427 SIGADDSET(sq->sq_kill, signo); 428 ret = 0; 429 goto out_set_bit; 430 } 431 return (ret); 432 } 433 434 out_set_bit: 435 SIGADDSET(sq->sq_signals, signo); 436 return (ret); 437 } 438 439 void 440 sigqueue_flush(sigqueue_t *sq) 441 { 442 struct proc *p = sq->sq_proc; 443 ksiginfo_t *ksi; 444 445 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 446 447 if (p != NULL) 448 PROC_LOCK_ASSERT(p, MA_OWNED); 449 450 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 451 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 452 ksi->ksi_sigq = NULL; 453 if (ksiginfo_tryfree(ksi) && p != NULL) 454 p->p_pendingcnt--; 455 } 456 457 SIGEMPTYSET(sq->sq_signals); 458 SIGEMPTYSET(sq->sq_kill); 459 SIGEMPTYSET(sq->sq_ptrace); 460 } 461 462 static void 463 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 464 { 465 sigset_t tmp; 466 struct proc *p1, *p2; 467 ksiginfo_t *ksi, *next; 468 469 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 470 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 471 p1 = src->sq_proc; 472 p2 = dst->sq_proc; 473 /* Move siginfo to target list */ 474 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 475 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 476 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 477 if (p1 != NULL) 478 p1->p_pendingcnt--; 479 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 480 ksi->ksi_sigq = dst; 481 if (p2 != NULL) 482 p2->p_pendingcnt++; 483 } 484 } 485 486 /* Move pending bits to target list */ 487 tmp = src->sq_kill; 488 SIGSETAND(tmp, *set); 489 SIGSETOR(dst->sq_kill, tmp); 490 SIGSETNAND(src->sq_kill, tmp); 491 492 tmp = src->sq_ptrace; 493 SIGSETAND(tmp, *set); 494 SIGSETOR(dst->sq_ptrace, tmp); 495 SIGSETNAND(src->sq_ptrace, tmp); 496 497 tmp = src->sq_signals; 498 SIGSETAND(tmp, *set); 499 SIGSETOR(dst->sq_signals, tmp); 500 SIGSETNAND(src->sq_signals, tmp); 501 } 502 503 #if 0 504 static void 505 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 506 { 507 sigset_t set; 508 509 SIGEMPTYSET(set); 510 SIGADDSET(set, signo); 511 sigqueue_move_set(src, dst, &set); 512 } 513 #endif 514 515 static void 516 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 517 { 518 struct proc *p = sq->sq_proc; 519 ksiginfo_t *ksi, *next; 520 521 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 522 523 /* Remove siginfo queue */ 524 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 525 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 526 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 527 ksi->ksi_sigq = NULL; 528 if (ksiginfo_tryfree(ksi) && p != NULL) 529 p->p_pendingcnt--; 530 } 531 } 532 SIGSETNAND(sq->sq_kill, *set); 533 SIGSETNAND(sq->sq_ptrace, *set); 534 SIGSETNAND(sq->sq_signals, *set); 535 } 536 537 void 538 sigqueue_delete(sigqueue_t *sq, int signo) 539 { 540 sigset_t set; 541 542 SIGEMPTYSET(set); 543 SIGADDSET(set, signo); 544 sigqueue_delete_set(sq, &set); 545 } 546 547 /* Remove a set of signals for a process */ 548 static void 549 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 550 { 551 sigqueue_t worklist; 552 struct thread *td0; 553 554 PROC_LOCK_ASSERT(p, MA_OWNED); 555 556 sigqueue_init(&worklist, NULL); 557 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 558 559 FOREACH_THREAD_IN_PROC(p, td0) 560 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 561 562 sigqueue_flush(&worklist); 563 } 564 565 void 566 sigqueue_delete_proc(struct proc *p, int signo) 567 { 568 sigset_t set; 569 570 SIGEMPTYSET(set); 571 SIGADDSET(set, signo); 572 sigqueue_delete_set_proc(p, &set); 573 } 574 575 static void 576 sigqueue_delete_stopmask_proc(struct proc *p) 577 { 578 sigset_t set; 579 580 SIGEMPTYSET(set); 581 SIGADDSET(set, SIGSTOP); 582 SIGADDSET(set, SIGTSTP); 583 SIGADDSET(set, SIGTTIN); 584 SIGADDSET(set, SIGTTOU); 585 sigqueue_delete_set_proc(p, &set); 586 } 587 588 /* 589 * Determine signal that should be delivered to thread td, the current 590 * thread, 0 if none. If there is a pending stop signal with default 591 * action, the process stops in issignal(). 592 */ 593 int 594 cursig(struct thread *td) 595 { 596 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 597 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 598 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 599 return (SIGPENDING(td) ? issignal(td) : 0); 600 } 601 602 /* 603 * Arrange for ast() to handle unmasked pending signals on return to user 604 * mode. This must be called whenever a signal is added to td_sigqueue or 605 * unmasked in td_sigmask. 606 */ 607 void 608 signotify(struct thread *td) 609 { 610 611 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 612 613 if (SIGPENDING(td)) { 614 thread_lock(td); 615 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 616 thread_unlock(td); 617 } 618 } 619 620 /* 621 * Returns 1 (true) if altstack is configured for the thread, and the 622 * passed stack bottom address falls into the altstack range. Handles 623 * the 43 compat special case where the alt stack size is zero. 624 */ 625 int 626 sigonstack(size_t sp) 627 { 628 struct thread *td; 629 630 td = curthread; 631 if ((td->td_pflags & TDP_ALTSTACK) == 0) 632 return (0); 633 #if defined(COMPAT_43) 634 if (SV_PROC_FLAG(td->td_proc, SV_AOUT) && td->td_sigstk.ss_size == 0) 635 return ((td->td_sigstk.ss_flags & SS_ONSTACK) != 0); 636 #endif 637 return (sp >= (size_t)td->td_sigstk.ss_sp && 638 sp < td->td_sigstk.ss_size + (size_t)td->td_sigstk.ss_sp); 639 } 640 641 static __inline int 642 sigprop(int sig) 643 { 644 645 if (sig > 0 && sig < nitems(sigproptbl)) 646 return (sigproptbl[sig]); 647 return (0); 648 } 649 650 int 651 sig_ffs(sigset_t *set) 652 { 653 int i; 654 655 for (i = 0; i < _SIG_WORDS; i++) 656 if (set->__bits[i]) 657 return (ffs(set->__bits[i]) + (i * 32)); 658 return (0); 659 } 660 661 static bool 662 sigact_flag_test(const struct sigaction *act, int flag) 663 { 664 665 /* 666 * SA_SIGINFO is reset when signal disposition is set to 667 * ignore or default. Other flags are kept according to user 668 * settings. 669 */ 670 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 671 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 672 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 673 } 674 675 /* 676 * kern_sigaction 677 * sigaction 678 * freebsd4_sigaction 679 * osigaction 680 */ 681 int 682 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 683 struct sigaction *oact, int flags) 684 { 685 struct sigacts *ps; 686 struct proc *p = td->td_proc; 687 688 if (!_SIG_VALID(sig)) 689 return (EINVAL); 690 if (act != NULL && act->sa_handler != SIG_DFL && 691 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 692 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 693 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 694 return (EINVAL); 695 696 PROC_LOCK(p); 697 ps = p->p_sigacts; 698 mtx_lock(&ps->ps_mtx); 699 if (oact) { 700 memset(oact, 0, sizeof(*oact)); 701 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 702 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 703 oact->sa_flags |= SA_ONSTACK; 704 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 705 oact->sa_flags |= SA_RESTART; 706 if (SIGISMEMBER(ps->ps_sigreset, sig)) 707 oact->sa_flags |= SA_RESETHAND; 708 if (SIGISMEMBER(ps->ps_signodefer, sig)) 709 oact->sa_flags |= SA_NODEFER; 710 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 711 oact->sa_flags |= SA_SIGINFO; 712 oact->sa_sigaction = 713 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 714 } else 715 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 716 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 717 oact->sa_flags |= SA_NOCLDSTOP; 718 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 719 oact->sa_flags |= SA_NOCLDWAIT; 720 } 721 if (act) { 722 if ((sig == SIGKILL || sig == SIGSTOP) && 723 act->sa_handler != SIG_DFL) { 724 mtx_unlock(&ps->ps_mtx); 725 PROC_UNLOCK(p); 726 return (EINVAL); 727 } 728 729 /* 730 * Change setting atomically. 731 */ 732 733 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 734 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 735 if (sigact_flag_test(act, SA_SIGINFO)) { 736 ps->ps_sigact[_SIG_IDX(sig)] = 737 (__sighandler_t *)act->sa_sigaction; 738 SIGADDSET(ps->ps_siginfo, sig); 739 } else { 740 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 741 SIGDELSET(ps->ps_siginfo, sig); 742 } 743 if (!sigact_flag_test(act, SA_RESTART)) 744 SIGADDSET(ps->ps_sigintr, sig); 745 else 746 SIGDELSET(ps->ps_sigintr, sig); 747 if (sigact_flag_test(act, SA_ONSTACK)) 748 SIGADDSET(ps->ps_sigonstack, sig); 749 else 750 SIGDELSET(ps->ps_sigonstack, sig); 751 if (sigact_flag_test(act, SA_RESETHAND)) 752 SIGADDSET(ps->ps_sigreset, sig); 753 else 754 SIGDELSET(ps->ps_sigreset, sig); 755 if (sigact_flag_test(act, SA_NODEFER)) 756 SIGADDSET(ps->ps_signodefer, sig); 757 else 758 SIGDELSET(ps->ps_signodefer, sig); 759 if (sig == SIGCHLD) { 760 if (act->sa_flags & SA_NOCLDSTOP) 761 ps->ps_flag |= PS_NOCLDSTOP; 762 else 763 ps->ps_flag &= ~PS_NOCLDSTOP; 764 if (act->sa_flags & SA_NOCLDWAIT) { 765 /* 766 * Paranoia: since SA_NOCLDWAIT is implemented 767 * by reparenting the dying child to PID 1 (and 768 * trust it to reap the zombie), PID 1 itself 769 * is forbidden to set SA_NOCLDWAIT. 770 */ 771 if (p->p_pid == 1) 772 ps->ps_flag &= ~PS_NOCLDWAIT; 773 else 774 ps->ps_flag |= PS_NOCLDWAIT; 775 } else 776 ps->ps_flag &= ~PS_NOCLDWAIT; 777 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 778 ps->ps_flag |= PS_CLDSIGIGN; 779 else 780 ps->ps_flag &= ~PS_CLDSIGIGN; 781 } 782 /* 783 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 784 * and for signals set to SIG_DFL where the default is to 785 * ignore. However, don't put SIGCONT in ps_sigignore, as we 786 * have to restart the process. 787 */ 788 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 789 (sigprop(sig) & SIGPROP_IGNORE && 790 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 791 /* never to be seen again */ 792 sigqueue_delete_proc(p, sig); 793 if (sig != SIGCONT) 794 /* easier in psignal */ 795 SIGADDSET(ps->ps_sigignore, sig); 796 SIGDELSET(ps->ps_sigcatch, sig); 797 } else { 798 SIGDELSET(ps->ps_sigignore, sig); 799 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 800 SIGDELSET(ps->ps_sigcatch, sig); 801 else 802 SIGADDSET(ps->ps_sigcatch, sig); 803 } 804 #ifdef COMPAT_FREEBSD4 805 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 806 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 807 (flags & KSA_FREEBSD4) == 0) 808 SIGDELSET(ps->ps_freebsd4, sig); 809 else 810 SIGADDSET(ps->ps_freebsd4, sig); 811 #endif 812 #ifdef COMPAT_43 813 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 814 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 815 (flags & KSA_OSIGSET) == 0) 816 SIGDELSET(ps->ps_osigset, sig); 817 else 818 SIGADDSET(ps->ps_osigset, sig); 819 #endif 820 } 821 mtx_unlock(&ps->ps_mtx); 822 PROC_UNLOCK(p); 823 return (0); 824 } 825 826 #ifndef _SYS_SYSPROTO_H_ 827 struct sigaction_args { 828 int sig; 829 struct sigaction *act; 830 struct sigaction *oact; 831 }; 832 #endif 833 int 834 sys_sigaction(struct thread *td, struct sigaction_args *uap) 835 { 836 struct sigaction act, oact; 837 struct sigaction *actp, *oactp; 838 int error; 839 840 actp = (uap->act != NULL) ? &act : NULL; 841 oactp = (uap->oact != NULL) ? &oact : NULL; 842 if (actp) { 843 error = copyin(uap->act, actp, sizeof(act)); 844 if (error) 845 return (error); 846 } 847 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 848 if (oactp && !error) 849 error = copyout(oactp, uap->oact, sizeof(oact)); 850 return (error); 851 } 852 853 #ifdef COMPAT_FREEBSD4 854 #ifndef _SYS_SYSPROTO_H_ 855 struct freebsd4_sigaction_args { 856 int sig; 857 struct sigaction *act; 858 struct sigaction *oact; 859 }; 860 #endif 861 int 862 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 863 { 864 struct sigaction act, oact; 865 struct sigaction *actp, *oactp; 866 int error; 867 868 869 actp = (uap->act != NULL) ? &act : NULL; 870 oactp = (uap->oact != NULL) ? &oact : NULL; 871 if (actp) { 872 error = copyin(uap->act, actp, sizeof(act)); 873 if (error) 874 return (error); 875 } 876 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 877 if (oactp && !error) 878 error = copyout(oactp, uap->oact, sizeof(oact)); 879 return (error); 880 } 881 #endif /* COMAPT_FREEBSD4 */ 882 883 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 884 #ifndef _SYS_SYSPROTO_H_ 885 struct osigaction_args { 886 int signum; 887 struct osigaction *nsa; 888 struct osigaction *osa; 889 }; 890 #endif 891 int 892 osigaction(struct thread *td, struct osigaction_args *uap) 893 { 894 struct osigaction sa; 895 struct sigaction nsa, osa; 896 struct sigaction *nsap, *osap; 897 int error; 898 899 if (uap->signum <= 0 || uap->signum >= ONSIG) 900 return (EINVAL); 901 902 nsap = (uap->nsa != NULL) ? &nsa : NULL; 903 osap = (uap->osa != NULL) ? &osa : NULL; 904 905 if (nsap) { 906 error = copyin(uap->nsa, &sa, sizeof(sa)); 907 if (error) 908 return (error); 909 nsap->sa_handler = sa.sa_handler; 910 nsap->sa_flags = sa.sa_flags; 911 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 912 } 913 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 914 if (osap && !error) { 915 sa.sa_handler = osap->sa_handler; 916 sa.sa_flags = osap->sa_flags; 917 SIG2OSIG(osap->sa_mask, sa.sa_mask); 918 error = copyout(&sa, uap->osa, sizeof(sa)); 919 } 920 return (error); 921 } 922 923 #if !defined(__i386__) 924 /* Avoid replicating the same stub everywhere */ 925 int 926 osigreturn(struct thread *td, struct osigreturn_args *uap) 927 { 928 929 return (nosys(td, (struct nosys_args *)uap)); 930 } 931 #endif 932 #endif /* COMPAT_43 */ 933 934 /* 935 * Initialize signal state for process 0; 936 * set to ignore signals that are ignored by default. 937 */ 938 void 939 siginit(struct proc *p) 940 { 941 int i; 942 struct sigacts *ps; 943 944 PROC_LOCK(p); 945 ps = p->p_sigacts; 946 mtx_lock(&ps->ps_mtx); 947 for (i = 1; i <= NSIG; i++) { 948 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 949 SIGADDSET(ps->ps_sigignore, i); 950 } 951 } 952 mtx_unlock(&ps->ps_mtx); 953 PROC_UNLOCK(p); 954 } 955 956 /* 957 * Reset specified signal to the default disposition. 958 */ 959 static void 960 sigdflt(struct sigacts *ps, int sig) 961 { 962 963 mtx_assert(&ps->ps_mtx, MA_OWNED); 964 SIGDELSET(ps->ps_sigcatch, sig); 965 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 966 SIGADDSET(ps->ps_sigignore, sig); 967 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 968 SIGDELSET(ps->ps_siginfo, sig); 969 } 970 971 /* 972 * Reset signals for an exec of the specified process. 973 */ 974 void 975 execsigs(struct proc *p) 976 { 977 sigset_t osigignore; 978 struct sigacts *ps; 979 int sig; 980 struct thread *td; 981 982 /* 983 * Reset caught signals. Held signals remain held 984 * through td_sigmask (unless they were caught, 985 * and are now ignored by default). 986 */ 987 PROC_LOCK_ASSERT(p, MA_OWNED); 988 ps = p->p_sigacts; 989 mtx_lock(&ps->ps_mtx); 990 sig_drop_caught(p); 991 992 /* 993 * As CloudABI processes cannot modify signal handlers, fully 994 * reset all signals to their default behavior. Do ignore 995 * SIGPIPE, as it would otherwise be impossible to recover from 996 * writes to broken pipes and sockets. 997 */ 998 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 999 osigignore = ps->ps_sigignore; 1000 while (SIGNOTEMPTY(osigignore)) { 1001 sig = sig_ffs(&osigignore); 1002 SIGDELSET(osigignore, sig); 1003 if (sig != SIGPIPE) 1004 sigdflt(ps, sig); 1005 } 1006 SIGADDSET(ps->ps_sigignore, SIGPIPE); 1007 } 1008 1009 /* 1010 * Reset stack state to the user stack. 1011 * Clear set of signals caught on the signal stack. 1012 */ 1013 td = curthread; 1014 MPASS(td->td_proc == p); 1015 td->td_sigstk.ss_flags = SS_DISABLE; 1016 td->td_sigstk.ss_size = 0; 1017 td->td_sigstk.ss_sp = 0; 1018 td->td_pflags &= ~TDP_ALTSTACK; 1019 /* 1020 * Reset no zombies if child dies flag as Solaris does. 1021 */ 1022 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1023 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1024 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1025 mtx_unlock(&ps->ps_mtx); 1026 } 1027 1028 /* 1029 * kern_sigprocmask() 1030 * 1031 * Manipulate signal mask. 1032 */ 1033 int 1034 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1035 int flags) 1036 { 1037 sigset_t new_block, oset1; 1038 struct proc *p; 1039 int error; 1040 1041 p = td->td_proc; 1042 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1043 PROC_LOCK_ASSERT(p, MA_OWNED); 1044 else 1045 PROC_LOCK(p); 1046 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1047 ? MA_OWNED : MA_NOTOWNED); 1048 if (oset != NULL) 1049 *oset = td->td_sigmask; 1050 1051 error = 0; 1052 if (set != NULL) { 1053 switch (how) { 1054 case SIG_BLOCK: 1055 SIG_CANTMASK(*set); 1056 oset1 = td->td_sigmask; 1057 SIGSETOR(td->td_sigmask, *set); 1058 new_block = td->td_sigmask; 1059 SIGSETNAND(new_block, oset1); 1060 break; 1061 case SIG_UNBLOCK: 1062 SIGSETNAND(td->td_sigmask, *set); 1063 signotify(td); 1064 goto out; 1065 case SIG_SETMASK: 1066 SIG_CANTMASK(*set); 1067 oset1 = td->td_sigmask; 1068 if (flags & SIGPROCMASK_OLD) 1069 SIGSETLO(td->td_sigmask, *set); 1070 else 1071 td->td_sigmask = *set; 1072 new_block = td->td_sigmask; 1073 SIGSETNAND(new_block, oset1); 1074 signotify(td); 1075 break; 1076 default: 1077 error = EINVAL; 1078 goto out; 1079 } 1080 1081 /* 1082 * The new_block set contains signals that were not previously 1083 * blocked, but are blocked now. 1084 * 1085 * In case we block any signal that was not previously blocked 1086 * for td, and process has the signal pending, try to schedule 1087 * signal delivery to some thread that does not block the 1088 * signal, possibly waking it up. 1089 */ 1090 if (p->p_numthreads != 1) 1091 reschedule_signals(p, new_block, flags); 1092 } 1093 1094 out: 1095 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1096 PROC_UNLOCK(p); 1097 return (error); 1098 } 1099 1100 #ifndef _SYS_SYSPROTO_H_ 1101 struct sigprocmask_args { 1102 int how; 1103 const sigset_t *set; 1104 sigset_t *oset; 1105 }; 1106 #endif 1107 int 1108 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1109 { 1110 sigset_t set, oset; 1111 sigset_t *setp, *osetp; 1112 int error; 1113 1114 setp = (uap->set != NULL) ? &set : NULL; 1115 osetp = (uap->oset != NULL) ? &oset : NULL; 1116 if (setp) { 1117 error = copyin(uap->set, setp, sizeof(set)); 1118 if (error) 1119 return (error); 1120 } 1121 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1122 if (osetp && !error) { 1123 error = copyout(osetp, uap->oset, sizeof(oset)); 1124 } 1125 return (error); 1126 } 1127 1128 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1129 #ifndef _SYS_SYSPROTO_H_ 1130 struct osigprocmask_args { 1131 int how; 1132 osigset_t mask; 1133 }; 1134 #endif 1135 int 1136 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1137 { 1138 sigset_t set, oset; 1139 int error; 1140 1141 OSIG2SIG(uap->mask, set); 1142 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1143 SIG2OSIG(oset, td->td_retval[0]); 1144 return (error); 1145 } 1146 #endif /* COMPAT_43 */ 1147 1148 int 1149 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1150 { 1151 ksiginfo_t ksi; 1152 sigset_t set; 1153 int error; 1154 1155 error = copyin(uap->set, &set, sizeof(set)); 1156 if (error) { 1157 td->td_retval[0] = error; 1158 return (0); 1159 } 1160 1161 error = kern_sigtimedwait(td, set, &ksi, NULL); 1162 if (error) { 1163 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1164 error = ERESTART; 1165 if (error == ERESTART) 1166 return (error); 1167 td->td_retval[0] = error; 1168 return (0); 1169 } 1170 1171 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1172 td->td_retval[0] = error; 1173 return (0); 1174 } 1175 1176 int 1177 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1178 { 1179 struct timespec ts; 1180 struct timespec *timeout; 1181 sigset_t set; 1182 ksiginfo_t ksi; 1183 int error; 1184 1185 if (uap->timeout) { 1186 error = copyin(uap->timeout, &ts, sizeof(ts)); 1187 if (error) 1188 return (error); 1189 1190 timeout = &ts; 1191 } else 1192 timeout = NULL; 1193 1194 error = copyin(uap->set, &set, sizeof(set)); 1195 if (error) 1196 return (error); 1197 1198 error = kern_sigtimedwait(td, set, &ksi, timeout); 1199 if (error) 1200 return (error); 1201 1202 if (uap->info) 1203 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1204 1205 if (error == 0) 1206 td->td_retval[0] = ksi.ksi_signo; 1207 return (error); 1208 } 1209 1210 int 1211 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1212 { 1213 ksiginfo_t ksi; 1214 sigset_t set; 1215 int error; 1216 1217 error = copyin(uap->set, &set, sizeof(set)); 1218 if (error) 1219 return (error); 1220 1221 error = kern_sigtimedwait(td, set, &ksi, NULL); 1222 if (error) 1223 return (error); 1224 1225 if (uap->info) 1226 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1227 1228 if (error == 0) 1229 td->td_retval[0] = ksi.ksi_signo; 1230 return (error); 1231 } 1232 1233 static void 1234 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1235 { 1236 struct thread *thr; 1237 1238 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1239 if (thr == td) 1240 thr->td_si = *si; 1241 else 1242 thr->td_si.si_signo = 0; 1243 } 1244 } 1245 1246 int 1247 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1248 struct timespec *timeout) 1249 { 1250 struct sigacts *ps; 1251 sigset_t saved_mask, new_block; 1252 struct proc *p; 1253 int error, sig, timo, timevalid = 0; 1254 struct timespec rts, ets, ts; 1255 struct timeval tv; 1256 bool traced; 1257 1258 p = td->td_proc; 1259 error = 0; 1260 ets.tv_sec = 0; 1261 ets.tv_nsec = 0; 1262 traced = false; 1263 1264 if (timeout != NULL) { 1265 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1266 timevalid = 1; 1267 getnanouptime(&rts); 1268 timespecadd(&rts, timeout, &ets); 1269 } 1270 } 1271 ksiginfo_init(ksi); 1272 /* Some signals can not be waited for. */ 1273 SIG_CANTMASK(waitset); 1274 ps = p->p_sigacts; 1275 PROC_LOCK(p); 1276 saved_mask = td->td_sigmask; 1277 SIGSETNAND(td->td_sigmask, waitset); 1278 for (;;) { 1279 mtx_lock(&ps->ps_mtx); 1280 sig = cursig(td); 1281 mtx_unlock(&ps->ps_mtx); 1282 KASSERT(sig >= 0, ("sig %d", sig)); 1283 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1284 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1285 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1286 error = 0; 1287 break; 1288 } 1289 } 1290 1291 if (error != 0) 1292 break; 1293 1294 /* 1295 * POSIX says this must be checked after looking for pending 1296 * signals. 1297 */ 1298 if (timeout != NULL) { 1299 if (!timevalid) { 1300 error = EINVAL; 1301 break; 1302 } 1303 getnanouptime(&rts); 1304 if (timespeccmp(&rts, &ets, >=)) { 1305 error = EAGAIN; 1306 break; 1307 } 1308 timespecsub(&ets, &rts, &ts); 1309 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1310 timo = tvtohz(&tv); 1311 } else { 1312 timo = 0; 1313 } 1314 1315 if (traced) { 1316 error = EINTR; 1317 break; 1318 } 1319 1320 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1321 1322 if (timeout != NULL) { 1323 if (error == ERESTART) { 1324 /* Timeout can not be restarted. */ 1325 error = EINTR; 1326 } else if (error == EAGAIN) { 1327 /* We will calculate timeout by ourself. */ 1328 error = 0; 1329 } 1330 } 1331 1332 /* 1333 * If PTRACE_SCE or PTRACE_SCX were set after 1334 * userspace entered the syscall, return spurious 1335 * EINTR after wait was done. Only do this as last 1336 * resort after rechecking for possible queued signals 1337 * and expired timeouts. 1338 */ 1339 if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0) 1340 traced = true; 1341 } 1342 1343 new_block = saved_mask; 1344 SIGSETNAND(new_block, td->td_sigmask); 1345 td->td_sigmask = saved_mask; 1346 /* 1347 * Fewer signals can be delivered to us, reschedule signal 1348 * notification. 1349 */ 1350 if (p->p_numthreads != 1) 1351 reschedule_signals(p, new_block, 0); 1352 1353 if (error == 0) { 1354 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1355 1356 if (ksi->ksi_code == SI_TIMER) 1357 itimer_accept(p, ksi->ksi_timerid, ksi); 1358 1359 #ifdef KTRACE 1360 if (KTRPOINT(td, KTR_PSIG)) { 1361 sig_t action; 1362 1363 mtx_lock(&ps->ps_mtx); 1364 action = ps->ps_sigact[_SIG_IDX(sig)]; 1365 mtx_unlock(&ps->ps_mtx); 1366 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1367 } 1368 #endif 1369 if (sig == SIGKILL) { 1370 proc_td_siginfo_capture(td, &ksi->ksi_info); 1371 sigexit(td, sig); 1372 } 1373 } 1374 PROC_UNLOCK(p); 1375 return (error); 1376 } 1377 1378 #ifndef _SYS_SYSPROTO_H_ 1379 struct sigpending_args { 1380 sigset_t *set; 1381 }; 1382 #endif 1383 int 1384 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1385 { 1386 struct proc *p = td->td_proc; 1387 sigset_t pending; 1388 1389 PROC_LOCK(p); 1390 pending = p->p_sigqueue.sq_signals; 1391 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1392 PROC_UNLOCK(p); 1393 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1394 } 1395 1396 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1397 #ifndef _SYS_SYSPROTO_H_ 1398 struct osigpending_args { 1399 int dummy; 1400 }; 1401 #endif 1402 int 1403 osigpending(struct thread *td, struct osigpending_args *uap) 1404 { 1405 struct proc *p = td->td_proc; 1406 sigset_t pending; 1407 1408 PROC_LOCK(p); 1409 pending = p->p_sigqueue.sq_signals; 1410 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1411 PROC_UNLOCK(p); 1412 SIG2OSIG(pending, td->td_retval[0]); 1413 return (0); 1414 } 1415 #endif /* COMPAT_43 */ 1416 1417 #if defined(COMPAT_43) 1418 /* 1419 * Generalized interface signal handler, 4.3-compatible. 1420 */ 1421 #ifndef _SYS_SYSPROTO_H_ 1422 struct osigvec_args { 1423 int signum; 1424 struct sigvec *nsv; 1425 struct sigvec *osv; 1426 }; 1427 #endif 1428 /* ARGSUSED */ 1429 int 1430 osigvec(struct thread *td, struct osigvec_args *uap) 1431 { 1432 struct sigvec vec; 1433 struct sigaction nsa, osa; 1434 struct sigaction *nsap, *osap; 1435 int error; 1436 1437 if (uap->signum <= 0 || uap->signum >= ONSIG) 1438 return (EINVAL); 1439 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1440 osap = (uap->osv != NULL) ? &osa : NULL; 1441 if (nsap) { 1442 error = copyin(uap->nsv, &vec, sizeof(vec)); 1443 if (error) 1444 return (error); 1445 nsap->sa_handler = vec.sv_handler; 1446 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1447 nsap->sa_flags = vec.sv_flags; 1448 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1449 } 1450 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1451 if (osap && !error) { 1452 vec.sv_handler = osap->sa_handler; 1453 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1454 vec.sv_flags = osap->sa_flags; 1455 vec.sv_flags &= ~SA_NOCLDWAIT; 1456 vec.sv_flags ^= SA_RESTART; 1457 error = copyout(&vec, uap->osv, sizeof(vec)); 1458 } 1459 return (error); 1460 } 1461 1462 #ifndef _SYS_SYSPROTO_H_ 1463 struct osigblock_args { 1464 int mask; 1465 }; 1466 #endif 1467 int 1468 osigblock(struct thread *td, struct osigblock_args *uap) 1469 { 1470 sigset_t set, oset; 1471 1472 OSIG2SIG(uap->mask, set); 1473 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1474 SIG2OSIG(oset, td->td_retval[0]); 1475 return (0); 1476 } 1477 1478 #ifndef _SYS_SYSPROTO_H_ 1479 struct osigsetmask_args { 1480 int mask; 1481 }; 1482 #endif 1483 int 1484 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1485 { 1486 sigset_t set, oset; 1487 1488 OSIG2SIG(uap->mask, set); 1489 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1490 SIG2OSIG(oset, td->td_retval[0]); 1491 return (0); 1492 } 1493 #endif /* COMPAT_43 */ 1494 1495 /* 1496 * Suspend calling thread until signal, providing mask to be set in the 1497 * meantime. 1498 */ 1499 #ifndef _SYS_SYSPROTO_H_ 1500 struct sigsuspend_args { 1501 const sigset_t *sigmask; 1502 }; 1503 #endif 1504 /* ARGSUSED */ 1505 int 1506 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1507 { 1508 sigset_t mask; 1509 int error; 1510 1511 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1512 if (error) 1513 return (error); 1514 return (kern_sigsuspend(td, mask)); 1515 } 1516 1517 int 1518 kern_sigsuspend(struct thread *td, sigset_t mask) 1519 { 1520 struct proc *p = td->td_proc; 1521 int has_sig, sig; 1522 1523 /* 1524 * When returning from sigsuspend, we want 1525 * the old mask to be restored after the 1526 * signal handler has finished. Thus, we 1527 * save it here and mark the sigacts structure 1528 * to indicate this. 1529 */ 1530 PROC_LOCK(p); 1531 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1532 SIGPROCMASK_PROC_LOCKED); 1533 td->td_pflags |= TDP_OLDMASK; 1534 1535 /* 1536 * Process signals now. Otherwise, we can get spurious wakeup 1537 * due to signal entered process queue, but delivered to other 1538 * thread. But sigsuspend should return only on signal 1539 * delivery. 1540 */ 1541 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1542 for (has_sig = 0; !has_sig;) { 1543 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1544 0) == 0) 1545 /* void */; 1546 thread_suspend_check(0); 1547 mtx_lock(&p->p_sigacts->ps_mtx); 1548 while ((sig = cursig(td)) != 0) { 1549 KASSERT(sig >= 0, ("sig %d", sig)); 1550 has_sig += postsig(sig); 1551 } 1552 mtx_unlock(&p->p_sigacts->ps_mtx); 1553 1554 /* 1555 * If PTRACE_SCE or PTRACE_SCX were set after 1556 * userspace entered the syscall, return spurious 1557 * EINTR. 1558 */ 1559 if ((p->p_ptevents & PTRACE_SYSCALL) != 0) 1560 has_sig += 1; 1561 } 1562 PROC_UNLOCK(p); 1563 td->td_errno = EINTR; 1564 td->td_pflags |= TDP_NERRNO; 1565 return (EJUSTRETURN); 1566 } 1567 1568 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1569 /* 1570 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1571 * convention: libc stub passes mask, not pointer, to save a copyin. 1572 */ 1573 #ifndef _SYS_SYSPROTO_H_ 1574 struct osigsuspend_args { 1575 osigset_t mask; 1576 }; 1577 #endif 1578 /* ARGSUSED */ 1579 int 1580 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1581 { 1582 sigset_t mask; 1583 1584 OSIG2SIG(uap->mask, mask); 1585 return (kern_sigsuspend(td, mask)); 1586 } 1587 #endif /* COMPAT_43 */ 1588 1589 #if defined(COMPAT_43) 1590 #ifndef _SYS_SYSPROTO_H_ 1591 struct osigstack_args { 1592 struct sigstack *nss; 1593 struct sigstack *oss; 1594 }; 1595 #endif 1596 /* ARGSUSED */ 1597 int 1598 osigstack(struct thread *td, struct osigstack_args *uap) 1599 { 1600 struct sigstack nss, oss; 1601 int error = 0; 1602 1603 if (uap->nss != NULL) { 1604 error = copyin(uap->nss, &nss, sizeof(nss)); 1605 if (error) 1606 return (error); 1607 } 1608 oss.ss_sp = td->td_sigstk.ss_sp; 1609 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1610 if (uap->nss != NULL) { 1611 td->td_sigstk.ss_sp = nss.ss_sp; 1612 td->td_sigstk.ss_size = 0; 1613 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1614 td->td_pflags |= TDP_ALTSTACK; 1615 } 1616 if (uap->oss != NULL) 1617 error = copyout(&oss, uap->oss, sizeof(oss)); 1618 1619 return (error); 1620 } 1621 #endif /* COMPAT_43 */ 1622 1623 #ifndef _SYS_SYSPROTO_H_ 1624 struct sigaltstack_args { 1625 stack_t *ss; 1626 stack_t *oss; 1627 }; 1628 #endif 1629 /* ARGSUSED */ 1630 int 1631 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1632 { 1633 stack_t ss, oss; 1634 int error; 1635 1636 if (uap->ss != NULL) { 1637 error = copyin(uap->ss, &ss, sizeof(ss)); 1638 if (error) 1639 return (error); 1640 } 1641 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1642 (uap->oss != NULL) ? &oss : NULL); 1643 if (error) 1644 return (error); 1645 if (uap->oss != NULL) 1646 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1647 return (error); 1648 } 1649 1650 int 1651 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1652 { 1653 struct proc *p = td->td_proc; 1654 int oonstack; 1655 1656 oonstack = sigonstack(cpu_getstack(td)); 1657 1658 if (oss != NULL) { 1659 *oss = td->td_sigstk; 1660 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1661 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1662 } 1663 1664 if (ss != NULL) { 1665 if (oonstack) 1666 return (EPERM); 1667 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1668 return (EINVAL); 1669 if (!(ss->ss_flags & SS_DISABLE)) { 1670 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1671 return (ENOMEM); 1672 1673 td->td_sigstk = *ss; 1674 td->td_pflags |= TDP_ALTSTACK; 1675 } else { 1676 td->td_pflags &= ~TDP_ALTSTACK; 1677 } 1678 } 1679 return (0); 1680 } 1681 1682 /* 1683 * Common code for kill process group/broadcast kill. 1684 * cp is calling process. 1685 */ 1686 static int 1687 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1688 { 1689 struct proc *p; 1690 struct pgrp *pgrp; 1691 int err; 1692 int ret; 1693 1694 ret = ESRCH; 1695 if (all) { 1696 /* 1697 * broadcast 1698 */ 1699 sx_slock(&allproc_lock); 1700 FOREACH_PROC_IN_SYSTEM(p) { 1701 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1702 p == td->td_proc || p->p_state == PRS_NEW) { 1703 continue; 1704 } 1705 PROC_LOCK(p); 1706 err = p_cansignal(td, p, sig); 1707 if (err == 0) { 1708 if (sig) 1709 pksignal(p, sig, ksi); 1710 ret = err; 1711 } 1712 else if (ret == ESRCH) 1713 ret = err; 1714 PROC_UNLOCK(p); 1715 } 1716 sx_sunlock(&allproc_lock); 1717 } else { 1718 sx_slock(&proctree_lock); 1719 if (pgid == 0) { 1720 /* 1721 * zero pgid means send to my process group. 1722 */ 1723 pgrp = td->td_proc->p_pgrp; 1724 PGRP_LOCK(pgrp); 1725 } else { 1726 pgrp = pgfind(pgid); 1727 if (pgrp == NULL) { 1728 sx_sunlock(&proctree_lock); 1729 return (ESRCH); 1730 } 1731 } 1732 sx_sunlock(&proctree_lock); 1733 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1734 PROC_LOCK(p); 1735 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1736 p->p_state == PRS_NEW) { 1737 PROC_UNLOCK(p); 1738 continue; 1739 } 1740 err = p_cansignal(td, p, sig); 1741 if (err == 0) { 1742 if (sig) 1743 pksignal(p, sig, ksi); 1744 ret = err; 1745 } 1746 else if (ret == ESRCH) 1747 ret = err; 1748 PROC_UNLOCK(p); 1749 } 1750 PGRP_UNLOCK(pgrp); 1751 } 1752 return (ret); 1753 } 1754 1755 #ifndef _SYS_SYSPROTO_H_ 1756 struct kill_args { 1757 int pid; 1758 int signum; 1759 }; 1760 #endif 1761 /* ARGSUSED */ 1762 int 1763 sys_kill(struct thread *td, struct kill_args *uap) 1764 { 1765 ksiginfo_t ksi; 1766 struct proc *p; 1767 int error; 1768 1769 /* 1770 * A process in capability mode can send signals only to himself. 1771 * The main rationale behind this is that abort(3) is implemented as 1772 * kill(getpid(), SIGABRT). 1773 */ 1774 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1775 return (ECAPMODE); 1776 1777 AUDIT_ARG_SIGNUM(uap->signum); 1778 AUDIT_ARG_PID(uap->pid); 1779 if ((u_int)uap->signum > _SIG_MAXSIG) 1780 return (EINVAL); 1781 1782 ksiginfo_init(&ksi); 1783 ksi.ksi_signo = uap->signum; 1784 ksi.ksi_code = SI_USER; 1785 ksi.ksi_pid = td->td_proc->p_pid; 1786 ksi.ksi_uid = td->td_ucred->cr_ruid; 1787 1788 if (uap->pid > 0) { 1789 /* kill single process */ 1790 if ((p = pfind_any(uap->pid)) == NULL) 1791 return (ESRCH); 1792 AUDIT_ARG_PROCESS(p); 1793 error = p_cansignal(td, p, uap->signum); 1794 if (error == 0 && uap->signum) 1795 pksignal(p, uap->signum, &ksi); 1796 PROC_UNLOCK(p); 1797 return (error); 1798 } 1799 switch (uap->pid) { 1800 case -1: /* broadcast signal */ 1801 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1802 case 0: /* signal own process group */ 1803 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1804 default: /* negative explicit process group */ 1805 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1806 } 1807 /* NOTREACHED */ 1808 } 1809 1810 int 1811 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1812 { 1813 struct proc *p; 1814 int error; 1815 1816 AUDIT_ARG_SIGNUM(uap->signum); 1817 AUDIT_ARG_FD(uap->fd); 1818 if ((u_int)uap->signum > _SIG_MAXSIG) 1819 return (EINVAL); 1820 1821 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1822 if (error) 1823 return (error); 1824 AUDIT_ARG_PROCESS(p); 1825 error = p_cansignal(td, p, uap->signum); 1826 if (error == 0 && uap->signum) 1827 kern_psignal(p, uap->signum); 1828 PROC_UNLOCK(p); 1829 return (error); 1830 } 1831 1832 #if defined(COMPAT_43) 1833 #ifndef _SYS_SYSPROTO_H_ 1834 struct okillpg_args { 1835 int pgid; 1836 int signum; 1837 }; 1838 #endif 1839 /* ARGSUSED */ 1840 int 1841 okillpg(struct thread *td, struct okillpg_args *uap) 1842 { 1843 ksiginfo_t ksi; 1844 1845 AUDIT_ARG_SIGNUM(uap->signum); 1846 AUDIT_ARG_PID(uap->pgid); 1847 if ((u_int)uap->signum > _SIG_MAXSIG) 1848 return (EINVAL); 1849 1850 ksiginfo_init(&ksi); 1851 ksi.ksi_signo = uap->signum; 1852 ksi.ksi_code = SI_USER; 1853 ksi.ksi_pid = td->td_proc->p_pid; 1854 ksi.ksi_uid = td->td_ucred->cr_ruid; 1855 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1856 } 1857 #endif /* COMPAT_43 */ 1858 1859 #ifndef _SYS_SYSPROTO_H_ 1860 struct sigqueue_args { 1861 pid_t pid; 1862 int signum; 1863 /* union sigval */ void *value; 1864 }; 1865 #endif 1866 int 1867 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1868 { 1869 union sigval sv; 1870 1871 sv.sival_ptr = uap->value; 1872 1873 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1874 } 1875 1876 int 1877 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1878 { 1879 ksiginfo_t ksi; 1880 struct proc *p; 1881 int error; 1882 1883 if ((u_int)signum > _SIG_MAXSIG) 1884 return (EINVAL); 1885 1886 /* 1887 * Specification says sigqueue can only send signal to 1888 * single process. 1889 */ 1890 if (pid <= 0) 1891 return (EINVAL); 1892 1893 if ((p = pfind_any(pid)) == NULL) 1894 return (ESRCH); 1895 error = p_cansignal(td, p, signum); 1896 if (error == 0 && signum != 0) { 1897 ksiginfo_init(&ksi); 1898 ksi.ksi_flags = KSI_SIGQ; 1899 ksi.ksi_signo = signum; 1900 ksi.ksi_code = SI_QUEUE; 1901 ksi.ksi_pid = td->td_proc->p_pid; 1902 ksi.ksi_uid = td->td_ucred->cr_ruid; 1903 ksi.ksi_value = *value; 1904 error = pksignal(p, ksi.ksi_signo, &ksi); 1905 } 1906 PROC_UNLOCK(p); 1907 return (error); 1908 } 1909 1910 /* 1911 * Send a signal to a process group. 1912 */ 1913 void 1914 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1915 { 1916 struct pgrp *pgrp; 1917 1918 if (pgid != 0) { 1919 sx_slock(&proctree_lock); 1920 pgrp = pgfind(pgid); 1921 sx_sunlock(&proctree_lock); 1922 if (pgrp != NULL) { 1923 pgsignal(pgrp, sig, 0, ksi); 1924 PGRP_UNLOCK(pgrp); 1925 } 1926 } 1927 } 1928 1929 /* 1930 * Send a signal to a process group. If checktty is 1, 1931 * limit to members which have a controlling terminal. 1932 */ 1933 void 1934 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1935 { 1936 struct proc *p; 1937 1938 if (pgrp) { 1939 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1940 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1941 PROC_LOCK(p); 1942 if (p->p_state == PRS_NORMAL && 1943 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1944 pksignal(p, sig, ksi); 1945 PROC_UNLOCK(p); 1946 } 1947 } 1948 } 1949 1950 1951 /* 1952 * Recalculate the signal mask and reset the signal disposition after 1953 * usermode frame for delivery is formed. Should be called after 1954 * mach-specific routine, because sysent->sv_sendsig() needs correct 1955 * ps_siginfo and signal mask. 1956 */ 1957 static void 1958 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1959 { 1960 sigset_t mask; 1961 1962 mtx_assert(&ps->ps_mtx, MA_OWNED); 1963 td->td_ru.ru_nsignals++; 1964 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1965 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1966 SIGADDSET(mask, sig); 1967 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1968 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1969 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1970 sigdflt(ps, sig); 1971 } 1972 1973 1974 /* 1975 * Send a signal caused by a trap to the current thread. If it will be 1976 * caught immediately, deliver it with correct code. Otherwise, post it 1977 * normally. 1978 */ 1979 void 1980 trapsignal(struct thread *td, ksiginfo_t *ksi) 1981 { 1982 struct sigacts *ps; 1983 struct proc *p; 1984 int sig; 1985 int code; 1986 1987 p = td->td_proc; 1988 sig = ksi->ksi_signo; 1989 code = ksi->ksi_code; 1990 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1991 1992 PROC_LOCK(p); 1993 ps = p->p_sigacts; 1994 mtx_lock(&ps->ps_mtx); 1995 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1996 !SIGISMEMBER(td->td_sigmask, sig)) { 1997 #ifdef KTRACE 1998 if (KTRPOINT(curthread, KTR_PSIG)) 1999 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 2000 &td->td_sigmask, code); 2001 #endif 2002 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 2003 ksi, &td->td_sigmask); 2004 postsig_done(sig, td, ps); 2005 mtx_unlock(&ps->ps_mtx); 2006 } else { 2007 /* 2008 * Avoid a possible infinite loop if the thread 2009 * masking the signal or process is ignoring the 2010 * signal. 2011 */ 2012 if (kern_forcesigexit && 2013 (SIGISMEMBER(td->td_sigmask, sig) || 2014 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2015 SIGDELSET(td->td_sigmask, sig); 2016 SIGDELSET(ps->ps_sigcatch, sig); 2017 SIGDELSET(ps->ps_sigignore, sig); 2018 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2019 } 2020 mtx_unlock(&ps->ps_mtx); 2021 p->p_sig = sig; /* XXX to verify code */ 2022 tdsendsignal(p, td, sig, ksi); 2023 } 2024 PROC_UNLOCK(p); 2025 } 2026 2027 static struct thread * 2028 sigtd(struct proc *p, int sig, int prop) 2029 { 2030 struct thread *td, *signal_td; 2031 2032 PROC_LOCK_ASSERT(p, MA_OWNED); 2033 2034 /* 2035 * Check if current thread can handle the signal without 2036 * switching context to another thread. 2037 */ 2038 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2039 return (curthread); 2040 signal_td = NULL; 2041 FOREACH_THREAD_IN_PROC(p, td) { 2042 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2043 signal_td = td; 2044 break; 2045 } 2046 } 2047 if (signal_td == NULL) 2048 signal_td = FIRST_THREAD_IN_PROC(p); 2049 return (signal_td); 2050 } 2051 2052 /* 2053 * Send the signal to the process. If the signal has an action, the action 2054 * is usually performed by the target process rather than the caller; we add 2055 * the signal to the set of pending signals for the process. 2056 * 2057 * Exceptions: 2058 * o When a stop signal is sent to a sleeping process that takes the 2059 * default action, the process is stopped without awakening it. 2060 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2061 * regardless of the signal action (eg, blocked or ignored). 2062 * 2063 * Other ignored signals are discarded immediately. 2064 * 2065 * NB: This function may be entered from the debugger via the "kill" DDB 2066 * command. There is little that can be done to mitigate the possibly messy 2067 * side effects of this unwise possibility. 2068 */ 2069 void 2070 kern_psignal(struct proc *p, int sig) 2071 { 2072 ksiginfo_t ksi; 2073 2074 ksiginfo_init(&ksi); 2075 ksi.ksi_signo = sig; 2076 ksi.ksi_code = SI_KERNEL; 2077 (void) tdsendsignal(p, NULL, sig, &ksi); 2078 } 2079 2080 int 2081 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2082 { 2083 2084 return (tdsendsignal(p, NULL, sig, ksi)); 2085 } 2086 2087 /* Utility function for finding a thread to send signal event to. */ 2088 int 2089 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2090 { 2091 struct thread *td; 2092 2093 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2094 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2095 if (td == NULL) 2096 return (ESRCH); 2097 *ttd = td; 2098 } else { 2099 *ttd = NULL; 2100 PROC_LOCK(p); 2101 } 2102 return (0); 2103 } 2104 2105 void 2106 tdsignal(struct thread *td, int sig) 2107 { 2108 ksiginfo_t ksi; 2109 2110 ksiginfo_init(&ksi); 2111 ksi.ksi_signo = sig; 2112 ksi.ksi_code = SI_KERNEL; 2113 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2114 } 2115 2116 void 2117 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2118 { 2119 2120 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2121 } 2122 2123 int 2124 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2125 { 2126 sig_t action; 2127 sigqueue_t *sigqueue; 2128 int prop; 2129 struct sigacts *ps; 2130 int intrval; 2131 int ret = 0; 2132 int wakeup_swapper; 2133 2134 MPASS(td == NULL || p == td->td_proc); 2135 PROC_LOCK_ASSERT(p, MA_OWNED); 2136 2137 if (!_SIG_VALID(sig)) 2138 panic("%s(): invalid signal %d", __func__, sig); 2139 2140 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2141 2142 /* 2143 * IEEE Std 1003.1-2001: return success when killing a zombie. 2144 */ 2145 if (p->p_state == PRS_ZOMBIE) { 2146 if (ksi && (ksi->ksi_flags & KSI_INS)) 2147 ksiginfo_tryfree(ksi); 2148 return (ret); 2149 } 2150 2151 ps = p->p_sigacts; 2152 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2153 prop = sigprop(sig); 2154 2155 if (td == NULL) { 2156 td = sigtd(p, sig, prop); 2157 sigqueue = &p->p_sigqueue; 2158 } else 2159 sigqueue = &td->td_sigqueue; 2160 2161 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2162 2163 /* 2164 * If the signal is being ignored, 2165 * then we forget about it immediately. 2166 * (Note: we don't set SIGCONT in ps_sigignore, 2167 * and if it is set to SIG_IGN, 2168 * action will be SIG_DFL here.) 2169 */ 2170 mtx_lock(&ps->ps_mtx); 2171 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2172 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2173 2174 mtx_unlock(&ps->ps_mtx); 2175 if (ksi && (ksi->ksi_flags & KSI_INS)) 2176 ksiginfo_tryfree(ksi); 2177 return (ret); 2178 } 2179 if (SIGISMEMBER(td->td_sigmask, sig)) 2180 action = SIG_HOLD; 2181 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2182 action = SIG_CATCH; 2183 else 2184 action = SIG_DFL; 2185 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2186 intrval = EINTR; 2187 else 2188 intrval = ERESTART; 2189 mtx_unlock(&ps->ps_mtx); 2190 2191 if (prop & SIGPROP_CONT) 2192 sigqueue_delete_stopmask_proc(p); 2193 else if (prop & SIGPROP_STOP) { 2194 /* 2195 * If sending a tty stop signal to a member of an orphaned 2196 * process group, discard the signal here if the action 2197 * is default; don't stop the process below if sleeping, 2198 * and don't clear any pending SIGCONT. 2199 */ 2200 if ((prop & SIGPROP_TTYSTOP) && 2201 (p->p_pgrp->pg_jobc == 0) && 2202 (action == SIG_DFL)) { 2203 if (ksi && (ksi->ksi_flags & KSI_INS)) 2204 ksiginfo_tryfree(ksi); 2205 return (ret); 2206 } 2207 sigqueue_delete_proc(p, SIGCONT); 2208 if (p->p_flag & P_CONTINUED) { 2209 p->p_flag &= ~P_CONTINUED; 2210 PROC_LOCK(p->p_pptr); 2211 sigqueue_take(p->p_ksi); 2212 PROC_UNLOCK(p->p_pptr); 2213 } 2214 } 2215 2216 ret = sigqueue_add(sigqueue, sig, ksi); 2217 if (ret != 0) 2218 return (ret); 2219 signotify(td); 2220 /* 2221 * Defer further processing for signals which are held, 2222 * except that stopped processes must be continued by SIGCONT. 2223 */ 2224 if (action == SIG_HOLD && 2225 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2226 return (ret); 2227 2228 /* SIGKILL: Remove procfs STOPEVENTs. */ 2229 if (sig == SIGKILL) { 2230 /* from procfs_ioctl.c: PIOCBIC */ 2231 p->p_stops = 0; 2232 /* from procfs_ioctl.c: PIOCCONT */ 2233 p->p_step = 0; 2234 wakeup(&p->p_step); 2235 } 2236 /* 2237 * Some signals have a process-wide effect and a per-thread 2238 * component. Most processing occurs when the process next 2239 * tries to cross the user boundary, however there are some 2240 * times when processing needs to be done immediately, such as 2241 * waking up threads so that they can cross the user boundary. 2242 * We try to do the per-process part here. 2243 */ 2244 if (P_SHOULDSTOP(p)) { 2245 KASSERT(!(p->p_flag & P_WEXIT), 2246 ("signal to stopped but exiting process")); 2247 if (sig == SIGKILL) { 2248 /* 2249 * If traced process is already stopped, 2250 * then no further action is necessary. 2251 */ 2252 if (p->p_flag & P_TRACED) 2253 goto out; 2254 /* 2255 * SIGKILL sets process running. 2256 * It will die elsewhere. 2257 * All threads must be restarted. 2258 */ 2259 p->p_flag &= ~P_STOPPED_SIG; 2260 goto runfast; 2261 } 2262 2263 if (prop & SIGPROP_CONT) { 2264 /* 2265 * If traced process is already stopped, 2266 * then no further action is necessary. 2267 */ 2268 if (p->p_flag & P_TRACED) 2269 goto out; 2270 /* 2271 * If SIGCONT is default (or ignored), we continue the 2272 * process but don't leave the signal in sigqueue as 2273 * it has no further action. If SIGCONT is held, we 2274 * continue the process and leave the signal in 2275 * sigqueue. If the process catches SIGCONT, let it 2276 * handle the signal itself. If it isn't waiting on 2277 * an event, it goes back to run state. 2278 * Otherwise, process goes back to sleep state. 2279 */ 2280 p->p_flag &= ~P_STOPPED_SIG; 2281 PROC_SLOCK(p); 2282 if (p->p_numthreads == p->p_suspcount) { 2283 PROC_SUNLOCK(p); 2284 p->p_flag |= P_CONTINUED; 2285 p->p_xsig = SIGCONT; 2286 PROC_LOCK(p->p_pptr); 2287 childproc_continued(p); 2288 PROC_UNLOCK(p->p_pptr); 2289 PROC_SLOCK(p); 2290 } 2291 if (action == SIG_DFL) { 2292 thread_unsuspend(p); 2293 PROC_SUNLOCK(p); 2294 sigqueue_delete(sigqueue, sig); 2295 goto out; 2296 } 2297 if (action == SIG_CATCH) { 2298 /* 2299 * The process wants to catch it so it needs 2300 * to run at least one thread, but which one? 2301 */ 2302 PROC_SUNLOCK(p); 2303 goto runfast; 2304 } 2305 /* 2306 * The signal is not ignored or caught. 2307 */ 2308 thread_unsuspend(p); 2309 PROC_SUNLOCK(p); 2310 goto out; 2311 } 2312 2313 if (prop & SIGPROP_STOP) { 2314 /* 2315 * If traced process is already stopped, 2316 * then no further action is necessary. 2317 */ 2318 if (p->p_flag & P_TRACED) 2319 goto out; 2320 /* 2321 * Already stopped, don't need to stop again 2322 * (If we did the shell could get confused). 2323 * Just make sure the signal STOP bit set. 2324 */ 2325 p->p_flag |= P_STOPPED_SIG; 2326 sigqueue_delete(sigqueue, sig); 2327 goto out; 2328 } 2329 2330 /* 2331 * All other kinds of signals: 2332 * If a thread is sleeping interruptibly, simulate a 2333 * wakeup so that when it is continued it will be made 2334 * runnable and can look at the signal. However, don't make 2335 * the PROCESS runnable, leave it stopped. 2336 * It may run a bit until it hits a thread_suspend_check(). 2337 */ 2338 wakeup_swapper = 0; 2339 PROC_SLOCK(p); 2340 thread_lock(td); 2341 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2342 wakeup_swapper = sleepq_abort(td, intrval); 2343 thread_unlock(td); 2344 PROC_SUNLOCK(p); 2345 if (wakeup_swapper) 2346 kick_proc0(); 2347 goto out; 2348 /* 2349 * Mutexes are short lived. Threads waiting on them will 2350 * hit thread_suspend_check() soon. 2351 */ 2352 } else if (p->p_state == PRS_NORMAL) { 2353 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2354 tdsigwakeup(td, sig, action, intrval); 2355 goto out; 2356 } 2357 2358 MPASS(action == SIG_DFL); 2359 2360 if (prop & SIGPROP_STOP) { 2361 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2362 goto out; 2363 p->p_flag |= P_STOPPED_SIG; 2364 p->p_xsig = sig; 2365 PROC_SLOCK(p); 2366 wakeup_swapper = sig_suspend_threads(td, p, 1); 2367 if (p->p_numthreads == p->p_suspcount) { 2368 /* 2369 * only thread sending signal to another 2370 * process can reach here, if thread is sending 2371 * signal to its process, because thread does 2372 * not suspend itself here, p_numthreads 2373 * should never be equal to p_suspcount. 2374 */ 2375 thread_stopped(p); 2376 PROC_SUNLOCK(p); 2377 sigqueue_delete_proc(p, p->p_xsig); 2378 } else 2379 PROC_SUNLOCK(p); 2380 if (wakeup_swapper) 2381 kick_proc0(); 2382 goto out; 2383 } 2384 } else { 2385 /* Not in "NORMAL" state. discard the signal. */ 2386 sigqueue_delete(sigqueue, sig); 2387 goto out; 2388 } 2389 2390 /* 2391 * The process is not stopped so we need to apply the signal to all the 2392 * running threads. 2393 */ 2394 runfast: 2395 tdsigwakeup(td, sig, action, intrval); 2396 PROC_SLOCK(p); 2397 thread_unsuspend(p); 2398 PROC_SUNLOCK(p); 2399 out: 2400 /* If we jump here, proc slock should not be owned. */ 2401 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2402 return (ret); 2403 } 2404 2405 /* 2406 * The force of a signal has been directed against a single 2407 * thread. We need to see what we can do about knocking it 2408 * out of any sleep it may be in etc. 2409 */ 2410 static void 2411 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2412 { 2413 struct proc *p = td->td_proc; 2414 int prop; 2415 int wakeup_swapper; 2416 2417 wakeup_swapper = 0; 2418 PROC_LOCK_ASSERT(p, MA_OWNED); 2419 prop = sigprop(sig); 2420 2421 PROC_SLOCK(p); 2422 thread_lock(td); 2423 /* 2424 * Bring the priority of a thread up if we want it to get 2425 * killed in this lifetime. Be careful to avoid bumping the 2426 * priority of the idle thread, since we still allow to signal 2427 * kernel processes. 2428 */ 2429 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2430 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2431 sched_prio(td, PUSER); 2432 if (TD_ON_SLEEPQ(td)) { 2433 /* 2434 * If thread is sleeping uninterruptibly 2435 * we can't interrupt the sleep... the signal will 2436 * be noticed when the process returns through 2437 * trap() or syscall(). 2438 */ 2439 if ((td->td_flags & TDF_SINTR) == 0) 2440 goto out; 2441 /* 2442 * If SIGCONT is default (or ignored) and process is 2443 * asleep, we are finished; the process should not 2444 * be awakened. 2445 */ 2446 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2447 thread_unlock(td); 2448 PROC_SUNLOCK(p); 2449 sigqueue_delete(&p->p_sigqueue, sig); 2450 /* 2451 * It may be on either list in this state. 2452 * Remove from both for now. 2453 */ 2454 sigqueue_delete(&td->td_sigqueue, sig); 2455 return; 2456 } 2457 2458 /* 2459 * Don't awaken a sleeping thread for SIGSTOP if the 2460 * STOP signal is deferred. 2461 */ 2462 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2463 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2464 goto out; 2465 2466 /* 2467 * Give low priority threads a better chance to run. 2468 */ 2469 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2470 sched_prio(td, PUSER); 2471 2472 wakeup_swapper = sleepq_abort(td, intrval); 2473 } else { 2474 /* 2475 * Other states do nothing with the signal immediately, 2476 * other than kicking ourselves if we are running. 2477 * It will either never be noticed, or noticed very soon. 2478 */ 2479 #ifdef SMP 2480 if (TD_IS_RUNNING(td) && td != curthread) 2481 forward_signal(td); 2482 #endif 2483 } 2484 out: 2485 PROC_SUNLOCK(p); 2486 thread_unlock(td); 2487 if (wakeup_swapper) 2488 kick_proc0(); 2489 } 2490 2491 static int 2492 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2493 { 2494 struct thread *td2; 2495 int wakeup_swapper; 2496 2497 PROC_LOCK_ASSERT(p, MA_OWNED); 2498 PROC_SLOCK_ASSERT(p, MA_OWNED); 2499 MPASS(sending || td == curthread); 2500 2501 wakeup_swapper = 0; 2502 FOREACH_THREAD_IN_PROC(p, td2) { 2503 thread_lock(td2); 2504 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2505 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2506 (td2->td_flags & TDF_SINTR)) { 2507 if (td2->td_flags & TDF_SBDRY) { 2508 /* 2509 * Once a thread is asleep with 2510 * TDF_SBDRY and without TDF_SERESTART 2511 * or TDF_SEINTR set, it should never 2512 * become suspended due to this check. 2513 */ 2514 KASSERT(!TD_IS_SUSPENDED(td2), 2515 ("thread with deferred stops suspended")); 2516 if (TD_SBDRY_INTR(td2)) 2517 wakeup_swapper |= sleepq_abort(td2, 2518 TD_SBDRY_ERRNO(td2)); 2519 } else if (!TD_IS_SUSPENDED(td2)) { 2520 thread_suspend_one(td2); 2521 } 2522 } else if (!TD_IS_SUSPENDED(td2)) { 2523 if (sending || td != td2) 2524 td2->td_flags |= TDF_ASTPENDING; 2525 #ifdef SMP 2526 if (TD_IS_RUNNING(td2) && td2 != td) 2527 forward_signal(td2); 2528 #endif 2529 } 2530 thread_unlock(td2); 2531 } 2532 return (wakeup_swapper); 2533 } 2534 2535 /* 2536 * Stop the process for an event deemed interesting to the debugger. If si is 2537 * non-NULL, this is a signal exchange; the new signal requested by the 2538 * debugger will be returned for handling. If si is NULL, this is some other 2539 * type of interesting event. The debugger may request a signal be delivered in 2540 * that case as well, however it will be deferred until it can be handled. 2541 */ 2542 int 2543 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2544 { 2545 struct proc *p = td->td_proc; 2546 struct thread *td2; 2547 ksiginfo_t ksi; 2548 int prop; 2549 2550 PROC_LOCK_ASSERT(p, MA_OWNED); 2551 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2552 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2553 &p->p_mtx.lock_object, "Stopping for traced signal"); 2554 2555 td->td_xsig = sig; 2556 2557 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2558 td->td_dbgflags |= TDB_XSIG; 2559 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2560 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2561 PROC_SLOCK(p); 2562 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2563 if (P_KILLED(p)) { 2564 /* 2565 * Ensure that, if we've been PT_KILLed, the 2566 * exit status reflects that. Another thread 2567 * may also be in ptracestop(), having just 2568 * received the SIGKILL, but this thread was 2569 * unsuspended first. 2570 */ 2571 td->td_dbgflags &= ~TDB_XSIG; 2572 td->td_xsig = SIGKILL; 2573 p->p_ptevents = 0; 2574 break; 2575 } 2576 if (p->p_flag & P_SINGLE_EXIT && 2577 !(td->td_dbgflags & TDB_EXIT)) { 2578 /* 2579 * Ignore ptrace stops except for thread exit 2580 * events when the process exits. 2581 */ 2582 td->td_dbgflags &= ~TDB_XSIG; 2583 PROC_SUNLOCK(p); 2584 return (0); 2585 } 2586 2587 /* 2588 * Make wait(2) work. Ensure that right after the 2589 * attach, the thread which was decided to become the 2590 * leader of attach gets reported to the waiter. 2591 * Otherwise, just avoid overwriting another thread's 2592 * assignment to p_xthread. If another thread has 2593 * already set p_xthread, the current thread will get 2594 * a chance to report itself upon the next iteration. 2595 */ 2596 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2597 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2598 p->p_xthread == NULL)) { 2599 p->p_xsig = sig; 2600 p->p_xthread = td; 2601 2602 /* 2603 * If we are on sleepqueue already, 2604 * let sleepqueue code decide if it 2605 * needs to go sleep after attach. 2606 */ 2607 if (td->td_wchan == NULL) 2608 td->td_dbgflags &= ~TDB_FSTP; 2609 2610 p->p_flag2 &= ~P2_PTRACE_FSTP; 2611 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2612 sig_suspend_threads(td, p, 0); 2613 } 2614 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2615 td->td_dbgflags &= ~TDB_STOPATFORK; 2616 } 2617 stopme: 2618 thread_suspend_switch(td, p); 2619 if (p->p_xthread == td) 2620 p->p_xthread = NULL; 2621 if (!(p->p_flag & P_TRACED)) 2622 break; 2623 if (td->td_dbgflags & TDB_SUSPEND) { 2624 if (p->p_flag & P_SINGLE_EXIT) 2625 break; 2626 goto stopme; 2627 } 2628 } 2629 PROC_SUNLOCK(p); 2630 } 2631 2632 if (si != NULL && sig == td->td_xsig) { 2633 /* Parent wants us to take the original signal unchanged. */ 2634 si->ksi_flags |= KSI_HEAD; 2635 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2636 si->ksi_signo = 0; 2637 } else if (td->td_xsig != 0) { 2638 /* 2639 * If parent wants us to take a new signal, then it will leave 2640 * it in td->td_xsig; otherwise we just look for signals again. 2641 */ 2642 ksiginfo_init(&ksi); 2643 ksi.ksi_signo = td->td_xsig; 2644 ksi.ksi_flags |= KSI_PTRACE; 2645 prop = sigprop(td->td_xsig); 2646 td2 = sigtd(p, td->td_xsig, prop); 2647 tdsendsignal(p, td2, td->td_xsig, &ksi); 2648 if (td != td2) 2649 return (0); 2650 } 2651 2652 return (td->td_xsig); 2653 } 2654 2655 static void 2656 reschedule_signals(struct proc *p, sigset_t block, int flags) 2657 { 2658 struct sigacts *ps; 2659 struct thread *td; 2660 int sig; 2661 2662 PROC_LOCK_ASSERT(p, MA_OWNED); 2663 ps = p->p_sigacts; 2664 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2665 MA_OWNED : MA_NOTOWNED); 2666 if (SIGISEMPTY(p->p_siglist)) 2667 return; 2668 SIGSETAND(block, p->p_siglist); 2669 while ((sig = sig_ffs(&block)) != 0) { 2670 SIGDELSET(block, sig); 2671 td = sigtd(p, sig, 0); 2672 signotify(td); 2673 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2674 mtx_lock(&ps->ps_mtx); 2675 if (p->p_flag & P_TRACED || 2676 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2677 !SIGISMEMBER(td->td_sigmask, sig))) 2678 tdsigwakeup(td, sig, SIG_CATCH, 2679 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2680 ERESTART)); 2681 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2682 mtx_unlock(&ps->ps_mtx); 2683 } 2684 } 2685 2686 void 2687 tdsigcleanup(struct thread *td) 2688 { 2689 struct proc *p; 2690 sigset_t unblocked; 2691 2692 p = td->td_proc; 2693 PROC_LOCK_ASSERT(p, MA_OWNED); 2694 2695 sigqueue_flush(&td->td_sigqueue); 2696 if (p->p_numthreads == 1) 2697 return; 2698 2699 /* 2700 * Since we cannot handle signals, notify signal post code 2701 * about this by filling the sigmask. 2702 * 2703 * Also, if needed, wake up thread(s) that do not block the 2704 * same signals as the exiting thread, since the thread might 2705 * have been selected for delivery and woken up. 2706 */ 2707 SIGFILLSET(unblocked); 2708 SIGSETNAND(unblocked, td->td_sigmask); 2709 SIGFILLSET(td->td_sigmask); 2710 reschedule_signals(p, unblocked, 0); 2711 2712 } 2713 2714 static int 2715 sigdeferstop_curr_flags(int cflags) 2716 { 2717 2718 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2719 (cflags & TDF_SBDRY) != 0); 2720 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2721 } 2722 2723 /* 2724 * Defer the delivery of SIGSTOP for the current thread, according to 2725 * the requested mode. Returns previous flags, which must be restored 2726 * by sigallowstop(). 2727 * 2728 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2729 * cleared by the current thread, which allow the lock-less read-only 2730 * accesses below. 2731 */ 2732 int 2733 sigdeferstop_impl(int mode) 2734 { 2735 struct thread *td; 2736 int cflags, nflags; 2737 2738 td = curthread; 2739 cflags = sigdeferstop_curr_flags(td->td_flags); 2740 switch (mode) { 2741 case SIGDEFERSTOP_NOP: 2742 nflags = cflags; 2743 break; 2744 case SIGDEFERSTOP_OFF: 2745 nflags = 0; 2746 break; 2747 case SIGDEFERSTOP_SILENT: 2748 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2749 break; 2750 case SIGDEFERSTOP_EINTR: 2751 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2752 break; 2753 case SIGDEFERSTOP_ERESTART: 2754 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2755 break; 2756 default: 2757 panic("sigdeferstop: invalid mode %x", mode); 2758 break; 2759 } 2760 if (cflags == nflags) 2761 return (SIGDEFERSTOP_VAL_NCHG); 2762 thread_lock(td); 2763 td->td_flags = (td->td_flags & ~cflags) | nflags; 2764 thread_unlock(td); 2765 return (cflags); 2766 } 2767 2768 /* 2769 * Restores the STOP handling mode, typically permitting the delivery 2770 * of SIGSTOP for the current thread. This does not immediately 2771 * suspend if a stop was posted. Instead, the thread will suspend 2772 * either via ast() or a subsequent interruptible sleep. 2773 */ 2774 void 2775 sigallowstop_impl(int prev) 2776 { 2777 struct thread *td; 2778 int cflags; 2779 2780 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2781 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2782 ("sigallowstop: incorrect previous mode %x", prev)); 2783 td = curthread; 2784 cflags = sigdeferstop_curr_flags(td->td_flags); 2785 if (cflags != prev) { 2786 thread_lock(td); 2787 td->td_flags = (td->td_flags & ~cflags) | prev; 2788 thread_unlock(td); 2789 } 2790 } 2791 2792 /* 2793 * If the current process has received a signal (should be caught or cause 2794 * termination, should interrupt current syscall), return the signal number. 2795 * Stop signals with default action are processed immediately, then cleared; 2796 * they aren't returned. This is checked after each entry to the system for 2797 * a syscall or trap (though this can usually be done without calling issignal 2798 * by checking the pending signal masks in cursig.) The normal call 2799 * sequence is 2800 * 2801 * while (sig = cursig(curthread)) 2802 * postsig(sig); 2803 */ 2804 static int 2805 issignal(struct thread *td) 2806 { 2807 struct proc *p; 2808 struct sigacts *ps; 2809 struct sigqueue *queue; 2810 sigset_t sigpending; 2811 ksiginfo_t ksi; 2812 int prop, sig, traced; 2813 2814 p = td->td_proc; 2815 ps = p->p_sigacts; 2816 mtx_assert(&ps->ps_mtx, MA_OWNED); 2817 PROC_LOCK_ASSERT(p, MA_OWNED); 2818 for (;;) { 2819 traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2820 2821 sigpending = td->td_sigqueue.sq_signals; 2822 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2823 SIGSETNAND(sigpending, td->td_sigmask); 2824 2825 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2826 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2827 SIG_STOPSIGMASK(sigpending); 2828 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2829 return (0); 2830 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2831 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2832 SIGISMEMBER(sigpending, SIGSTOP)) { 2833 /* 2834 * If debugger just attached, always consume 2835 * SIGSTOP from ptrace(PT_ATTACH) first, to 2836 * execute the debugger attach ritual in 2837 * order. 2838 */ 2839 sig = SIGSTOP; 2840 td->td_dbgflags |= TDB_FSTP; 2841 } else { 2842 sig = sig_ffs(&sigpending); 2843 } 2844 2845 if (p->p_stops & S_SIG) { 2846 mtx_unlock(&ps->ps_mtx); 2847 stopevent(p, S_SIG, sig); 2848 mtx_lock(&ps->ps_mtx); 2849 } 2850 2851 /* 2852 * We should see pending but ignored signals 2853 * only if P_TRACED was on when they were posted. 2854 */ 2855 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2856 sigqueue_delete(&td->td_sigqueue, sig); 2857 sigqueue_delete(&p->p_sigqueue, sig); 2858 continue; 2859 } 2860 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2861 /* 2862 * If traced, always stop. 2863 * Remove old signal from queue before the stop. 2864 * XXX shrug off debugger, it causes siginfo to 2865 * be thrown away. 2866 */ 2867 queue = &td->td_sigqueue; 2868 ksiginfo_init(&ksi); 2869 if (sigqueue_get(queue, sig, &ksi) == 0) { 2870 queue = &p->p_sigqueue; 2871 sigqueue_get(queue, sig, &ksi); 2872 } 2873 td->td_si = ksi.ksi_info; 2874 2875 mtx_unlock(&ps->ps_mtx); 2876 sig = ptracestop(td, sig, &ksi); 2877 mtx_lock(&ps->ps_mtx); 2878 2879 td->td_si.si_signo = 0; 2880 2881 /* 2882 * Keep looking if the debugger discarded or 2883 * replaced the signal. 2884 */ 2885 if (sig == 0) 2886 continue; 2887 2888 /* 2889 * If the signal became masked, re-queue it. 2890 */ 2891 if (SIGISMEMBER(td->td_sigmask, sig)) { 2892 ksi.ksi_flags |= KSI_HEAD; 2893 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2894 continue; 2895 } 2896 2897 /* 2898 * If the traced bit got turned off, requeue 2899 * the signal and go back up to the top to 2900 * rescan signals. This ensures that p_sig* 2901 * and p_sigact are consistent. 2902 */ 2903 if ((p->p_flag & P_TRACED) == 0) { 2904 ksi.ksi_flags |= KSI_HEAD; 2905 sigqueue_add(queue, sig, &ksi); 2906 continue; 2907 } 2908 } 2909 2910 prop = sigprop(sig); 2911 2912 /* 2913 * Decide whether the signal should be returned. 2914 * Return the signal's number, or fall through 2915 * to clear it from the pending mask. 2916 */ 2917 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2918 2919 case (intptr_t)SIG_DFL: 2920 /* 2921 * Don't take default actions on system processes. 2922 */ 2923 if (p->p_pid <= 1) { 2924 #ifdef DIAGNOSTIC 2925 /* 2926 * Are you sure you want to ignore SIGSEGV 2927 * in init? XXX 2928 */ 2929 printf("Process (pid %lu) got signal %d\n", 2930 (u_long)p->p_pid, sig); 2931 #endif 2932 break; /* == ignore */ 2933 } 2934 /* 2935 * If there is a pending stop signal to process with 2936 * default action, stop here, then clear the signal. 2937 * Traced or exiting processes should ignore stops. 2938 * Additionally, a member of an orphaned process group 2939 * should ignore tty stops. 2940 */ 2941 if (prop & SIGPROP_STOP) { 2942 if (p->p_flag & 2943 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 2944 (p->p_pgrp->pg_jobc == 0 && 2945 prop & SIGPROP_TTYSTOP)) 2946 break; /* == ignore */ 2947 if (TD_SBDRY_INTR(td)) { 2948 KASSERT((td->td_flags & TDF_SBDRY) != 0, 2949 ("lost TDF_SBDRY")); 2950 return (-1); 2951 } 2952 mtx_unlock(&ps->ps_mtx); 2953 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2954 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2955 sigqueue_delete(&td->td_sigqueue, sig); 2956 sigqueue_delete(&p->p_sigqueue, sig); 2957 p->p_flag |= P_STOPPED_SIG; 2958 p->p_xsig = sig; 2959 PROC_SLOCK(p); 2960 sig_suspend_threads(td, p, 0); 2961 thread_suspend_switch(td, p); 2962 PROC_SUNLOCK(p); 2963 mtx_lock(&ps->ps_mtx); 2964 goto next; 2965 } else if (prop & SIGPROP_IGNORE) { 2966 /* 2967 * Except for SIGCONT, shouldn't get here. 2968 * Default action is to ignore; drop it. 2969 */ 2970 break; /* == ignore */ 2971 } else 2972 return (sig); 2973 /*NOTREACHED*/ 2974 2975 case (intptr_t)SIG_IGN: 2976 /* 2977 * Masking above should prevent us ever trying 2978 * to take action on an ignored signal other 2979 * than SIGCONT, unless process is traced. 2980 */ 2981 if ((prop & SIGPROP_CONT) == 0 && 2982 (p->p_flag & P_TRACED) == 0) 2983 printf("issignal\n"); 2984 break; /* == ignore */ 2985 2986 default: 2987 /* 2988 * This signal has an action, let 2989 * postsig() process it. 2990 */ 2991 return (sig); 2992 } 2993 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2994 sigqueue_delete(&p->p_sigqueue, sig); 2995 next:; 2996 } 2997 /* NOTREACHED */ 2998 } 2999 3000 void 3001 thread_stopped(struct proc *p) 3002 { 3003 int n; 3004 3005 PROC_LOCK_ASSERT(p, MA_OWNED); 3006 PROC_SLOCK_ASSERT(p, MA_OWNED); 3007 n = p->p_suspcount; 3008 if (p == curproc) 3009 n++; 3010 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 3011 PROC_SUNLOCK(p); 3012 p->p_flag &= ~P_WAITED; 3013 PROC_LOCK(p->p_pptr); 3014 childproc_stopped(p, (p->p_flag & P_TRACED) ? 3015 CLD_TRAPPED : CLD_STOPPED); 3016 PROC_UNLOCK(p->p_pptr); 3017 PROC_SLOCK(p); 3018 } 3019 } 3020 3021 /* 3022 * Take the action for the specified signal 3023 * from the current set of pending signals. 3024 */ 3025 int 3026 postsig(int sig) 3027 { 3028 struct thread *td; 3029 struct proc *p; 3030 struct sigacts *ps; 3031 sig_t action; 3032 ksiginfo_t ksi; 3033 sigset_t returnmask; 3034 3035 KASSERT(sig != 0, ("postsig")); 3036 3037 td = curthread; 3038 p = td->td_proc; 3039 PROC_LOCK_ASSERT(p, MA_OWNED); 3040 ps = p->p_sigacts; 3041 mtx_assert(&ps->ps_mtx, MA_OWNED); 3042 ksiginfo_init(&ksi); 3043 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3044 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3045 return (0); 3046 ksi.ksi_signo = sig; 3047 if (ksi.ksi_code == SI_TIMER) 3048 itimer_accept(p, ksi.ksi_timerid, &ksi); 3049 action = ps->ps_sigact[_SIG_IDX(sig)]; 3050 #ifdef KTRACE 3051 if (KTRPOINT(td, KTR_PSIG)) 3052 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3053 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3054 #endif 3055 if ((p->p_stops & S_SIG) != 0) { 3056 mtx_unlock(&ps->ps_mtx); 3057 stopevent(p, S_SIG, sig); 3058 mtx_lock(&ps->ps_mtx); 3059 } 3060 3061 if (action == SIG_DFL) { 3062 /* 3063 * Default action, where the default is to kill 3064 * the process. (Other cases were ignored above.) 3065 */ 3066 mtx_unlock(&ps->ps_mtx); 3067 proc_td_siginfo_capture(td, &ksi.ksi_info); 3068 sigexit(td, sig); 3069 /* NOTREACHED */ 3070 } else { 3071 /* 3072 * If we get here, the signal must be caught. 3073 */ 3074 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3075 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3076 ("postsig action: blocked sig %d", sig)); 3077 3078 /* 3079 * Set the new mask value and also defer further 3080 * occurrences of this signal. 3081 * 3082 * Special case: user has done a sigsuspend. Here the 3083 * current mask is not of interest, but rather the 3084 * mask from before the sigsuspend is what we want 3085 * restored after the signal processing is completed. 3086 */ 3087 if (td->td_pflags & TDP_OLDMASK) { 3088 returnmask = td->td_oldsigmask; 3089 td->td_pflags &= ~TDP_OLDMASK; 3090 } else 3091 returnmask = td->td_sigmask; 3092 3093 if (p->p_sig == sig) { 3094 p->p_sig = 0; 3095 } 3096 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3097 postsig_done(sig, td, ps); 3098 } 3099 return (1); 3100 } 3101 3102 void 3103 proc_wkilled(struct proc *p) 3104 { 3105 3106 PROC_LOCK_ASSERT(p, MA_OWNED); 3107 if ((p->p_flag & P_WKILLED) == 0) { 3108 p->p_flag |= P_WKILLED; 3109 /* 3110 * Notify swapper that there is a process to swap in. 3111 * The notification is racy, at worst it would take 10 3112 * seconds for the swapper process to notice. 3113 */ 3114 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3115 wakeup(&proc0); 3116 } 3117 } 3118 3119 /* 3120 * Kill the current process for stated reason. 3121 */ 3122 void 3123 killproc(struct proc *p, char *why) 3124 { 3125 3126 PROC_LOCK_ASSERT(p, MA_OWNED); 3127 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3128 p->p_comm); 3129 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3130 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3131 p->p_ucred->cr_uid, why); 3132 proc_wkilled(p); 3133 kern_psignal(p, SIGKILL); 3134 } 3135 3136 /* 3137 * Force the current process to exit with the specified signal, dumping core 3138 * if appropriate. We bypass the normal tests for masked and caught signals, 3139 * allowing unrecoverable failures to terminate the process without changing 3140 * signal state. Mark the accounting record with the signal termination. 3141 * If dumping core, save the signal number for the debugger. Calls exit and 3142 * does not return. 3143 */ 3144 void 3145 sigexit(struct thread *td, int sig) 3146 { 3147 struct proc *p = td->td_proc; 3148 3149 PROC_LOCK_ASSERT(p, MA_OWNED); 3150 p->p_acflag |= AXSIG; 3151 /* 3152 * We must be single-threading to generate a core dump. This 3153 * ensures that the registers in the core file are up-to-date. 3154 * Also, the ELF dump handler assumes that the thread list doesn't 3155 * change out from under it. 3156 * 3157 * XXX If another thread attempts to single-thread before us 3158 * (e.g. via fork()), we won't get a dump at all. 3159 */ 3160 if ((sigprop(sig) & SIGPROP_CORE) && 3161 thread_single(p, SINGLE_NO_EXIT) == 0) { 3162 p->p_sig = sig; 3163 /* 3164 * Log signals which would cause core dumps 3165 * (Log as LOG_INFO to appease those who don't want 3166 * these messages.) 3167 * XXX : Todo, as well as euid, write out ruid too 3168 * Note that coredump() drops proc lock. 3169 */ 3170 if (coredump(td) == 0) 3171 sig |= WCOREFLAG; 3172 if (kern_logsigexit) 3173 log(LOG_INFO, 3174 "pid %d (%s), jid %d, uid %d: exited on " 3175 "signal %d%s\n", p->p_pid, p->p_comm, 3176 p->p_ucred->cr_prison->pr_id, 3177 td->td_ucred->cr_uid, 3178 sig &~ WCOREFLAG, 3179 sig & WCOREFLAG ? " (core dumped)" : ""); 3180 } else 3181 PROC_UNLOCK(p); 3182 exit1(td, 0, sig); 3183 /* NOTREACHED */ 3184 } 3185 3186 /* 3187 * Send queued SIGCHLD to parent when child process's state 3188 * is changed. 3189 */ 3190 static void 3191 sigparent(struct proc *p, int reason, int status) 3192 { 3193 PROC_LOCK_ASSERT(p, MA_OWNED); 3194 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3195 3196 if (p->p_ksi != NULL) { 3197 p->p_ksi->ksi_signo = SIGCHLD; 3198 p->p_ksi->ksi_code = reason; 3199 p->p_ksi->ksi_status = status; 3200 p->p_ksi->ksi_pid = p->p_pid; 3201 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3202 if (KSI_ONQ(p->p_ksi)) 3203 return; 3204 } 3205 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3206 } 3207 3208 static void 3209 childproc_jobstate(struct proc *p, int reason, int sig) 3210 { 3211 struct sigacts *ps; 3212 3213 PROC_LOCK_ASSERT(p, MA_OWNED); 3214 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3215 3216 /* 3217 * Wake up parent sleeping in kern_wait(), also send 3218 * SIGCHLD to parent, but SIGCHLD does not guarantee 3219 * that parent will awake, because parent may masked 3220 * the signal. 3221 */ 3222 p->p_pptr->p_flag |= P_STATCHILD; 3223 wakeup(p->p_pptr); 3224 3225 ps = p->p_pptr->p_sigacts; 3226 mtx_lock(&ps->ps_mtx); 3227 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3228 mtx_unlock(&ps->ps_mtx); 3229 sigparent(p, reason, sig); 3230 } else 3231 mtx_unlock(&ps->ps_mtx); 3232 } 3233 3234 void 3235 childproc_stopped(struct proc *p, int reason) 3236 { 3237 3238 childproc_jobstate(p, reason, p->p_xsig); 3239 } 3240 3241 void 3242 childproc_continued(struct proc *p) 3243 { 3244 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3245 } 3246 3247 void 3248 childproc_exited(struct proc *p) 3249 { 3250 int reason, status; 3251 3252 if (WCOREDUMP(p->p_xsig)) { 3253 reason = CLD_DUMPED; 3254 status = WTERMSIG(p->p_xsig); 3255 } else if (WIFSIGNALED(p->p_xsig)) { 3256 reason = CLD_KILLED; 3257 status = WTERMSIG(p->p_xsig); 3258 } else { 3259 reason = CLD_EXITED; 3260 status = p->p_xexit; 3261 } 3262 /* 3263 * XXX avoid calling wakeup(p->p_pptr), the work is 3264 * done in exit1(). 3265 */ 3266 sigparent(p, reason, status); 3267 } 3268 3269 #define MAX_NUM_CORE_FILES 100000 3270 #ifndef NUM_CORE_FILES 3271 #define NUM_CORE_FILES 5 3272 #endif 3273 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3274 static int num_cores = NUM_CORE_FILES; 3275 3276 static int 3277 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3278 { 3279 int error; 3280 int new_val; 3281 3282 new_val = num_cores; 3283 error = sysctl_handle_int(oidp, &new_val, 0, req); 3284 if (error != 0 || req->newptr == NULL) 3285 return (error); 3286 if (new_val > MAX_NUM_CORE_FILES) 3287 new_val = MAX_NUM_CORE_FILES; 3288 if (new_val < 0) 3289 new_val = 0; 3290 num_cores = new_val; 3291 return (0); 3292 } 3293 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3294 0, sizeof(int), sysctl_debug_num_cores_check, "I", 3295 "Maximum number of generated process corefiles while using index format"); 3296 3297 #define GZIP_SUFFIX ".gz" 3298 #define ZSTD_SUFFIX ".zst" 3299 3300 int compress_user_cores = 0; 3301 3302 static int 3303 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3304 { 3305 int error, val; 3306 3307 val = compress_user_cores; 3308 error = sysctl_handle_int(oidp, &val, 0, req); 3309 if (error != 0 || req->newptr == NULL) 3310 return (error); 3311 if (val != 0 && !compressor_avail(val)) 3312 return (EINVAL); 3313 compress_user_cores = val; 3314 return (error); 3315 } 3316 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, CTLTYPE_INT | CTLFLAG_RWTUN, 3317 0, sizeof(int), sysctl_compress_user_cores, "I", 3318 "Enable compression of user corefiles (" 3319 __XSTRING(COMPRESS_GZIP) " = gzip, " 3320 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3321 3322 int compress_user_cores_level = 6; 3323 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3324 &compress_user_cores_level, 0, 3325 "Corefile compression level"); 3326 3327 /* 3328 * Protect the access to corefilename[] by allproc_lock. 3329 */ 3330 #define corefilename_lock allproc_lock 3331 3332 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3333 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3334 3335 static int 3336 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3337 { 3338 int error; 3339 3340 sx_xlock(&corefilename_lock); 3341 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3342 req); 3343 sx_xunlock(&corefilename_lock); 3344 3345 return (error); 3346 } 3347 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3348 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3349 "Process corefile name format string"); 3350 3351 static void 3352 vnode_close_locked(struct thread *td, struct vnode *vp) 3353 { 3354 3355 VOP_UNLOCK(vp, 0); 3356 vn_close(vp, FWRITE, td->td_ucred, td); 3357 } 3358 3359 /* 3360 * If the core format has a %I in it, then we need to check 3361 * for existing corefiles before defining a name. 3362 * To do this we iterate over 0..ncores to find a 3363 * non-existing core file name to use. If all core files are 3364 * already used we choose the oldest one. 3365 */ 3366 static int 3367 corefile_open_last(struct thread *td, char *name, int indexpos, 3368 int indexlen, int ncores, struct vnode **vpp) 3369 { 3370 struct vnode *oldvp, *nextvp, *vp; 3371 struct vattr vattr; 3372 struct nameidata nd; 3373 int error, i, flags, oflags, cmode; 3374 char ch; 3375 struct timespec lasttime; 3376 3377 nextvp = oldvp = NULL; 3378 cmode = S_IRUSR | S_IWUSR; 3379 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3380 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3381 3382 for (i = 0; i < ncores; i++) { 3383 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3384 3385 ch = name[indexpos + indexlen]; 3386 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3387 i); 3388 name[indexpos + indexlen] = ch; 3389 3390 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3391 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3392 NULL); 3393 if (error != 0) 3394 break; 3395 3396 vp = nd.ni_vp; 3397 NDFREE(&nd, NDF_ONLY_PNBUF); 3398 if ((flags & O_CREAT) == O_CREAT) { 3399 nextvp = vp; 3400 break; 3401 } 3402 3403 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3404 if (error != 0) { 3405 vnode_close_locked(td, vp); 3406 break; 3407 } 3408 3409 if (oldvp == NULL || 3410 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3411 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3412 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3413 if (oldvp != NULL) 3414 vnode_close_locked(td, oldvp); 3415 oldvp = vp; 3416 lasttime = vattr.va_mtime; 3417 } else { 3418 vnode_close_locked(td, vp); 3419 } 3420 } 3421 3422 if (oldvp != NULL) { 3423 if (nextvp == NULL) { 3424 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3425 error = EFAULT; 3426 vnode_close_locked(td, oldvp); 3427 } else { 3428 nextvp = oldvp; 3429 } 3430 } else { 3431 vnode_close_locked(td, oldvp); 3432 } 3433 } 3434 if (error != 0) { 3435 if (nextvp != NULL) 3436 vnode_close_locked(td, oldvp); 3437 } else { 3438 *vpp = nextvp; 3439 } 3440 3441 return (error); 3442 } 3443 3444 /* 3445 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3446 * Expand the name described in corefilename, using name, uid, and pid 3447 * and open/create core file. 3448 * corefilename is a printf-like string, with three format specifiers: 3449 * %N name of process ("name") 3450 * %P process id (pid) 3451 * %U user id (uid) 3452 * For example, "%N.core" is the default; they can be disabled completely 3453 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3454 * This is controlled by the sysctl variable kern.corefile (see above). 3455 */ 3456 static int 3457 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3458 int compress, int signum, struct vnode **vpp, char **namep) 3459 { 3460 struct sbuf sb; 3461 struct nameidata nd; 3462 const char *format; 3463 char *hostname, *name; 3464 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3465 3466 hostname = NULL; 3467 format = corefilename; 3468 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3469 indexlen = 0; 3470 indexpos = -1; 3471 ncores = num_cores; 3472 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3473 sx_slock(&corefilename_lock); 3474 for (i = 0; format[i] != '\0'; i++) { 3475 switch (format[i]) { 3476 case '%': /* Format character */ 3477 i++; 3478 switch (format[i]) { 3479 case '%': 3480 sbuf_putc(&sb, '%'); 3481 break; 3482 case 'H': /* hostname */ 3483 if (hostname == NULL) { 3484 hostname = malloc(MAXHOSTNAMELEN, 3485 M_TEMP, M_WAITOK); 3486 } 3487 getcredhostname(td->td_ucred, hostname, 3488 MAXHOSTNAMELEN); 3489 sbuf_printf(&sb, "%s", hostname); 3490 break; 3491 case 'I': /* autoincrementing index */ 3492 if (indexpos != -1) { 3493 sbuf_printf(&sb, "%%I"); 3494 break; 3495 } 3496 3497 indexpos = sbuf_len(&sb); 3498 sbuf_printf(&sb, "%u", ncores - 1); 3499 indexlen = sbuf_len(&sb) - indexpos; 3500 break; 3501 case 'N': /* process name */ 3502 sbuf_printf(&sb, "%s", comm); 3503 break; 3504 case 'P': /* process id */ 3505 sbuf_printf(&sb, "%u", pid); 3506 break; 3507 case 'S': /* signal number */ 3508 sbuf_printf(&sb, "%i", signum); 3509 break; 3510 case 'U': /* user id */ 3511 sbuf_printf(&sb, "%u", uid); 3512 break; 3513 default: 3514 log(LOG_ERR, 3515 "Unknown format character %c in " 3516 "corename `%s'\n", format[i], format); 3517 break; 3518 } 3519 break; 3520 default: 3521 sbuf_putc(&sb, format[i]); 3522 break; 3523 } 3524 } 3525 sx_sunlock(&corefilename_lock); 3526 free(hostname, M_TEMP); 3527 if (compress == COMPRESS_GZIP) 3528 sbuf_printf(&sb, GZIP_SUFFIX); 3529 else if (compress == COMPRESS_ZSTD) 3530 sbuf_printf(&sb, ZSTD_SUFFIX); 3531 if (sbuf_error(&sb) != 0) { 3532 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3533 "long\n", (long)pid, comm, (u_long)uid); 3534 sbuf_delete(&sb); 3535 free(name, M_TEMP); 3536 return (ENOMEM); 3537 } 3538 sbuf_finish(&sb); 3539 sbuf_delete(&sb); 3540 3541 if (indexpos != -1) { 3542 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3543 vpp); 3544 if (error != 0) { 3545 log(LOG_ERR, 3546 "pid %d (%s), uid (%u): Path `%s' failed " 3547 "on initial open test, error = %d\n", 3548 pid, comm, uid, name, error); 3549 } 3550 } else { 3551 cmode = S_IRUSR | S_IWUSR; 3552 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3553 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3554 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3555 if ((td->td_proc->p_flag & P_SUGID) != 0) 3556 flags |= O_EXCL; 3557 3558 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3559 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3560 NULL); 3561 if (error == 0) { 3562 *vpp = nd.ni_vp; 3563 NDFREE(&nd, NDF_ONLY_PNBUF); 3564 } 3565 } 3566 3567 if (error != 0) { 3568 #ifdef AUDIT 3569 audit_proc_coredump(td, name, error); 3570 #endif 3571 free(name, M_TEMP); 3572 return (error); 3573 } 3574 *namep = name; 3575 return (0); 3576 } 3577 3578 /* 3579 * Dump a process' core. The main routine does some 3580 * policy checking, and creates the name of the coredump; 3581 * then it passes on a vnode and a size limit to the process-specific 3582 * coredump routine if there is one; if there _is not_ one, it returns 3583 * ENOSYS; otherwise it returns the error from the process-specific routine. 3584 */ 3585 3586 static int 3587 coredump(struct thread *td) 3588 { 3589 struct proc *p = td->td_proc; 3590 struct ucred *cred = td->td_ucred; 3591 struct vnode *vp; 3592 struct flock lf; 3593 struct vattr vattr; 3594 int error, error1, locked; 3595 char *name; /* name of corefile */ 3596 void *rl_cookie; 3597 off_t limit; 3598 char *fullpath, *freepath = NULL; 3599 struct sbuf *sb; 3600 3601 PROC_LOCK_ASSERT(p, MA_OWNED); 3602 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3603 _STOPEVENT(p, S_CORE, 0); 3604 3605 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3606 (p->p_flag2 & P2_NOTRACE) != 0) { 3607 PROC_UNLOCK(p); 3608 return (EFAULT); 3609 } 3610 3611 /* 3612 * Note that the bulk of limit checking is done after 3613 * the corefile is created. The exception is if the limit 3614 * for corefiles is 0, in which case we don't bother 3615 * creating the corefile at all. This layout means that 3616 * a corefile is truncated instead of not being created, 3617 * if it is larger than the limit. 3618 */ 3619 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3620 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3621 PROC_UNLOCK(p); 3622 return (EFBIG); 3623 } 3624 PROC_UNLOCK(p); 3625 3626 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3627 compress_user_cores, p->p_sig, &vp, &name); 3628 if (error != 0) 3629 return (error); 3630 3631 /* 3632 * Don't dump to non-regular files or files with links. 3633 * Do not dump into system files. Effective user must own the corefile. 3634 */ 3635 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3636 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 3637 vattr.va_uid != cred->cr_uid) { 3638 VOP_UNLOCK(vp, 0); 3639 error = EFAULT; 3640 goto out; 3641 } 3642 3643 VOP_UNLOCK(vp, 0); 3644 3645 /* Postpone other writers, including core dumps of other processes. */ 3646 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3647 3648 lf.l_whence = SEEK_SET; 3649 lf.l_start = 0; 3650 lf.l_len = 0; 3651 lf.l_type = F_WRLCK; 3652 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3653 3654 VATTR_NULL(&vattr); 3655 vattr.va_size = 0; 3656 if (set_core_nodump_flag) 3657 vattr.va_flags = UF_NODUMP; 3658 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3659 VOP_SETATTR(vp, &vattr, cred); 3660 VOP_UNLOCK(vp, 0); 3661 PROC_LOCK(p); 3662 p->p_acflag |= ACORE; 3663 PROC_UNLOCK(p); 3664 3665 if (p->p_sysent->sv_coredump != NULL) { 3666 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3667 } else { 3668 error = ENOSYS; 3669 } 3670 3671 if (locked) { 3672 lf.l_type = F_UNLCK; 3673 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3674 } 3675 vn_rangelock_unlock(vp, rl_cookie); 3676 3677 /* 3678 * Notify the userland helper that a process triggered a core dump. 3679 * This allows the helper to run an automated debugging session. 3680 */ 3681 if (error != 0 || coredump_devctl == 0) 3682 goto out; 3683 sb = sbuf_new_auto(); 3684 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3685 goto out2; 3686 sbuf_printf(sb, "comm=\""); 3687 devctl_safe_quote_sb(sb, fullpath); 3688 free(freepath, M_TEMP); 3689 sbuf_printf(sb, "\" core=\""); 3690 3691 /* 3692 * We can't lookup core file vp directly. When we're replacing a core, and 3693 * other random times, we flush the name cache, so it will fail. Instead, 3694 * if the path of the core is relative, add the current dir in front if it. 3695 */ 3696 if (name[0] != '/') { 3697 fullpath = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 3698 if (kern___getcwd(td, fullpath, UIO_SYSSPACE, MAXPATHLEN, MAXPATHLEN) != 0) { 3699 free(fullpath, M_TEMP); 3700 goto out2; 3701 } 3702 devctl_safe_quote_sb(sb, fullpath); 3703 free(fullpath, M_TEMP); 3704 sbuf_putc(sb, '/'); 3705 } 3706 devctl_safe_quote_sb(sb, name); 3707 sbuf_printf(sb, "\""); 3708 if (sbuf_finish(sb) == 0) 3709 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 3710 out2: 3711 sbuf_delete(sb); 3712 out: 3713 error1 = vn_close(vp, FWRITE, cred, td); 3714 if (error == 0) 3715 error = error1; 3716 #ifdef AUDIT 3717 audit_proc_coredump(td, name, error); 3718 #endif 3719 free(name, M_TEMP); 3720 return (error); 3721 } 3722 3723 /* 3724 * Nonexistent system call-- signal process (may want to handle it). Flag 3725 * error in case process won't see signal immediately (blocked or ignored). 3726 */ 3727 #ifndef _SYS_SYSPROTO_H_ 3728 struct nosys_args { 3729 int dummy; 3730 }; 3731 #endif 3732 /* ARGSUSED */ 3733 int 3734 nosys(struct thread *td, struct nosys_args *args) 3735 { 3736 struct proc *p; 3737 3738 p = td->td_proc; 3739 3740 PROC_LOCK(p); 3741 tdsignal(td, SIGSYS); 3742 PROC_UNLOCK(p); 3743 if (kern_lognosys == 1 || kern_lognosys == 3) { 3744 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3745 td->td_sa.code); 3746 } 3747 if (kern_lognosys == 2 || kern_lognosys == 3) { 3748 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3749 td->td_sa.code); 3750 } 3751 return (ENOSYS); 3752 } 3753 3754 /* 3755 * Send a SIGIO or SIGURG signal to a process or process group using stored 3756 * credentials rather than those of the current process. 3757 */ 3758 void 3759 pgsigio(struct sigio **sigiop, int sig, int checkctty) 3760 { 3761 ksiginfo_t ksi; 3762 struct sigio *sigio; 3763 3764 ksiginfo_init(&ksi); 3765 ksi.ksi_signo = sig; 3766 ksi.ksi_code = SI_KERNEL; 3767 3768 SIGIO_LOCK(); 3769 sigio = *sigiop; 3770 if (sigio == NULL) { 3771 SIGIO_UNLOCK(); 3772 return; 3773 } 3774 if (sigio->sio_pgid > 0) { 3775 PROC_LOCK(sigio->sio_proc); 3776 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3777 kern_psignal(sigio->sio_proc, sig); 3778 PROC_UNLOCK(sigio->sio_proc); 3779 } else if (sigio->sio_pgid < 0) { 3780 struct proc *p; 3781 3782 PGRP_LOCK(sigio->sio_pgrp); 3783 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3784 PROC_LOCK(p); 3785 if (p->p_state == PRS_NORMAL && 3786 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3787 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3788 kern_psignal(p, sig); 3789 PROC_UNLOCK(p); 3790 } 3791 PGRP_UNLOCK(sigio->sio_pgrp); 3792 } 3793 SIGIO_UNLOCK(); 3794 } 3795 3796 static int 3797 filt_sigattach(struct knote *kn) 3798 { 3799 struct proc *p = curproc; 3800 3801 kn->kn_ptr.p_proc = p; 3802 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3803 3804 knlist_add(p->p_klist, kn, 0); 3805 3806 return (0); 3807 } 3808 3809 static void 3810 filt_sigdetach(struct knote *kn) 3811 { 3812 struct proc *p = kn->kn_ptr.p_proc; 3813 3814 knlist_remove(p->p_klist, kn, 0); 3815 } 3816 3817 /* 3818 * signal knotes are shared with proc knotes, so we apply a mask to 3819 * the hint in order to differentiate them from process hints. This 3820 * could be avoided by using a signal-specific knote list, but probably 3821 * isn't worth the trouble. 3822 */ 3823 static int 3824 filt_signal(struct knote *kn, long hint) 3825 { 3826 3827 if (hint & NOTE_SIGNAL) { 3828 hint &= ~NOTE_SIGNAL; 3829 3830 if (kn->kn_id == hint) 3831 kn->kn_data++; 3832 } 3833 return (kn->kn_data != 0); 3834 } 3835 3836 struct sigacts * 3837 sigacts_alloc(void) 3838 { 3839 struct sigacts *ps; 3840 3841 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3842 refcount_init(&ps->ps_refcnt, 1); 3843 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3844 return (ps); 3845 } 3846 3847 void 3848 sigacts_free(struct sigacts *ps) 3849 { 3850 3851 if (refcount_release(&ps->ps_refcnt) == 0) 3852 return; 3853 mtx_destroy(&ps->ps_mtx); 3854 free(ps, M_SUBPROC); 3855 } 3856 3857 struct sigacts * 3858 sigacts_hold(struct sigacts *ps) 3859 { 3860 3861 refcount_acquire(&ps->ps_refcnt); 3862 return (ps); 3863 } 3864 3865 void 3866 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3867 { 3868 3869 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3870 mtx_lock(&src->ps_mtx); 3871 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3872 mtx_unlock(&src->ps_mtx); 3873 } 3874 3875 int 3876 sigacts_shared(struct sigacts *ps) 3877 { 3878 3879 return (ps->ps_refcnt > 1); 3880 } 3881 3882 void 3883 sig_drop_caught(struct proc *p) 3884 { 3885 int sig; 3886 struct sigacts *ps; 3887 3888 ps = p->p_sigacts; 3889 PROC_LOCK_ASSERT(p, MA_OWNED); 3890 mtx_assert(&ps->ps_mtx, MA_OWNED); 3891 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 3892 sig = sig_ffs(&ps->ps_sigcatch); 3893 sigdflt(ps, sig); 3894 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 3895 sigqueue_delete_proc(p, sig); 3896 } 3897 } 3898