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 struct killpg1_ctx { 1683 struct thread *td; 1684 ksiginfo_t *ksi; 1685 int sig; 1686 bool sent; 1687 bool found; 1688 int ret; 1689 }; 1690 1691 static void 1692 killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg) 1693 { 1694 int err; 1695 1696 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 || 1697 (notself && p == arg->td->td_proc) || p->p_state == PRS_NEW) 1698 return; 1699 PROC_LOCK(p); 1700 err = p_cansignal(arg->td, p, arg->sig); 1701 if (err == 0 && arg->sig != 0) 1702 pksignal(p, arg->sig, arg->ksi); 1703 PROC_UNLOCK(p); 1704 if (err != ESRCH) 1705 arg->found = true; 1706 if (err == 0) 1707 arg->sent = true; 1708 else if (arg->ret == 0 && err != ESRCH && err != EPERM) 1709 arg->ret = err; 1710 } 1711 1712 /* 1713 * Common code for kill process group/broadcast kill. 1714 * cp is calling process. 1715 */ 1716 static int 1717 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1718 { 1719 struct proc *p; 1720 struct pgrp *pgrp; 1721 struct killpg1_ctx arg; 1722 1723 arg.td = td; 1724 arg.ksi = ksi; 1725 arg.sig = sig; 1726 arg.sent = false; 1727 arg.found = false; 1728 arg.ret = 0; 1729 if (all) { 1730 /* 1731 * broadcast 1732 */ 1733 sx_slock(&allproc_lock); 1734 FOREACH_PROC_IN_SYSTEM(p) { 1735 killpg1_sendsig(p, true, &arg); 1736 } 1737 sx_sunlock(&allproc_lock); 1738 } else { 1739 sx_slock(&proctree_lock); 1740 if (pgid == 0) { 1741 /* 1742 * zero pgid means send to my process group. 1743 */ 1744 pgrp = td->td_proc->p_pgrp; 1745 PGRP_LOCK(pgrp); 1746 } else { 1747 pgrp = pgfind(pgid); 1748 if (pgrp == NULL) { 1749 sx_sunlock(&proctree_lock); 1750 return (ESRCH); 1751 } 1752 } 1753 sx_sunlock(&proctree_lock); 1754 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1755 killpg1_sendsig(p, false, &arg); 1756 } 1757 PGRP_UNLOCK(pgrp); 1758 } 1759 MPASS(arg.ret != 0 || arg.found || !arg.sent); 1760 if (arg.ret == 0 && !arg.sent) 1761 arg.ret = arg.found ? EPERM : ESRCH; 1762 return (arg.ret); 1763 } 1764 1765 #ifndef _SYS_SYSPROTO_H_ 1766 struct kill_args { 1767 int pid; 1768 int signum; 1769 }; 1770 #endif 1771 /* ARGSUSED */ 1772 int 1773 sys_kill(struct thread *td, struct kill_args *uap) 1774 { 1775 ksiginfo_t ksi; 1776 struct proc *p; 1777 int error; 1778 1779 /* 1780 * A process in capability mode can send signals only to himself. 1781 * The main rationale behind this is that abort(3) is implemented as 1782 * kill(getpid(), SIGABRT). 1783 */ 1784 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1785 return (ECAPMODE); 1786 1787 AUDIT_ARG_SIGNUM(uap->signum); 1788 AUDIT_ARG_PID(uap->pid); 1789 if ((u_int)uap->signum > _SIG_MAXSIG) 1790 return (EINVAL); 1791 1792 ksiginfo_init(&ksi); 1793 ksi.ksi_signo = uap->signum; 1794 ksi.ksi_code = SI_USER; 1795 ksi.ksi_pid = td->td_proc->p_pid; 1796 ksi.ksi_uid = td->td_ucred->cr_ruid; 1797 1798 if (uap->pid > 0) { 1799 /* kill single process */ 1800 if ((p = pfind_any(uap->pid)) == NULL) 1801 return (ESRCH); 1802 AUDIT_ARG_PROCESS(p); 1803 error = p_cansignal(td, p, uap->signum); 1804 if (error == 0 && uap->signum) 1805 pksignal(p, uap->signum, &ksi); 1806 PROC_UNLOCK(p); 1807 return (error); 1808 } 1809 switch (uap->pid) { 1810 case -1: /* broadcast signal */ 1811 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1812 case 0: /* signal own process group */ 1813 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1814 default: /* negative explicit process group */ 1815 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1816 } 1817 /* NOTREACHED */ 1818 } 1819 1820 int 1821 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1822 { 1823 struct proc *p; 1824 int error; 1825 1826 AUDIT_ARG_SIGNUM(uap->signum); 1827 AUDIT_ARG_FD(uap->fd); 1828 if ((u_int)uap->signum > _SIG_MAXSIG) 1829 return (EINVAL); 1830 1831 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1832 if (error) 1833 return (error); 1834 AUDIT_ARG_PROCESS(p); 1835 error = p_cansignal(td, p, uap->signum); 1836 if (error == 0 && uap->signum) 1837 kern_psignal(p, uap->signum); 1838 PROC_UNLOCK(p); 1839 return (error); 1840 } 1841 1842 #if defined(COMPAT_43) 1843 #ifndef _SYS_SYSPROTO_H_ 1844 struct okillpg_args { 1845 int pgid; 1846 int signum; 1847 }; 1848 #endif 1849 /* ARGSUSED */ 1850 int 1851 okillpg(struct thread *td, struct okillpg_args *uap) 1852 { 1853 ksiginfo_t ksi; 1854 1855 AUDIT_ARG_SIGNUM(uap->signum); 1856 AUDIT_ARG_PID(uap->pgid); 1857 if ((u_int)uap->signum > _SIG_MAXSIG) 1858 return (EINVAL); 1859 1860 ksiginfo_init(&ksi); 1861 ksi.ksi_signo = uap->signum; 1862 ksi.ksi_code = SI_USER; 1863 ksi.ksi_pid = td->td_proc->p_pid; 1864 ksi.ksi_uid = td->td_ucred->cr_ruid; 1865 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1866 } 1867 #endif /* COMPAT_43 */ 1868 1869 #ifndef _SYS_SYSPROTO_H_ 1870 struct sigqueue_args { 1871 pid_t pid; 1872 int signum; 1873 /* union sigval */ void *value; 1874 }; 1875 #endif 1876 int 1877 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1878 { 1879 union sigval sv; 1880 1881 sv.sival_ptr = uap->value; 1882 1883 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1884 } 1885 1886 int 1887 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1888 { 1889 ksiginfo_t ksi; 1890 struct proc *p; 1891 int error; 1892 1893 if ((u_int)signum > _SIG_MAXSIG) 1894 return (EINVAL); 1895 1896 /* 1897 * Specification says sigqueue can only send signal to 1898 * single process. 1899 */ 1900 if (pid <= 0) 1901 return (EINVAL); 1902 1903 if ((p = pfind_any(pid)) == NULL) 1904 return (ESRCH); 1905 error = p_cansignal(td, p, signum); 1906 if (error == 0 && signum != 0) { 1907 ksiginfo_init(&ksi); 1908 ksi.ksi_flags = KSI_SIGQ; 1909 ksi.ksi_signo = signum; 1910 ksi.ksi_code = SI_QUEUE; 1911 ksi.ksi_pid = td->td_proc->p_pid; 1912 ksi.ksi_uid = td->td_ucred->cr_ruid; 1913 ksi.ksi_value = *value; 1914 error = pksignal(p, ksi.ksi_signo, &ksi); 1915 } 1916 PROC_UNLOCK(p); 1917 return (error); 1918 } 1919 1920 /* 1921 * Send a signal to a process group. 1922 */ 1923 void 1924 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1925 { 1926 struct pgrp *pgrp; 1927 1928 if (pgid != 0) { 1929 sx_slock(&proctree_lock); 1930 pgrp = pgfind(pgid); 1931 sx_sunlock(&proctree_lock); 1932 if (pgrp != NULL) { 1933 pgsignal(pgrp, sig, 0, ksi); 1934 PGRP_UNLOCK(pgrp); 1935 } 1936 } 1937 } 1938 1939 /* 1940 * Send a signal to a process group. If checktty is 1, 1941 * limit to members which have a controlling terminal. 1942 */ 1943 void 1944 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1945 { 1946 struct proc *p; 1947 1948 if (pgrp) { 1949 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1950 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1951 PROC_LOCK(p); 1952 if (p->p_state == PRS_NORMAL && 1953 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1954 pksignal(p, sig, ksi); 1955 PROC_UNLOCK(p); 1956 } 1957 } 1958 } 1959 1960 1961 /* 1962 * Recalculate the signal mask and reset the signal disposition after 1963 * usermode frame for delivery is formed. Should be called after 1964 * mach-specific routine, because sysent->sv_sendsig() needs correct 1965 * ps_siginfo and signal mask. 1966 */ 1967 static void 1968 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1969 { 1970 sigset_t mask; 1971 1972 mtx_assert(&ps->ps_mtx, MA_OWNED); 1973 td->td_ru.ru_nsignals++; 1974 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1975 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1976 SIGADDSET(mask, sig); 1977 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1978 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1979 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1980 sigdflt(ps, sig); 1981 } 1982 1983 1984 /* 1985 * Send a signal caused by a trap to the current thread. If it will be 1986 * caught immediately, deliver it with correct code. Otherwise, post it 1987 * normally. 1988 */ 1989 void 1990 trapsignal(struct thread *td, ksiginfo_t *ksi) 1991 { 1992 struct sigacts *ps; 1993 struct proc *p; 1994 int sig; 1995 int code; 1996 1997 p = td->td_proc; 1998 sig = ksi->ksi_signo; 1999 code = ksi->ksi_code; 2000 KASSERT(_SIG_VALID(sig), ("invalid signal")); 2001 2002 PROC_LOCK(p); 2003 ps = p->p_sigacts; 2004 mtx_lock(&ps->ps_mtx); 2005 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 2006 !SIGISMEMBER(td->td_sigmask, sig)) { 2007 #ifdef KTRACE 2008 if (KTRPOINT(curthread, KTR_PSIG)) 2009 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 2010 &td->td_sigmask, code); 2011 #endif 2012 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 2013 ksi, &td->td_sigmask); 2014 postsig_done(sig, td, ps); 2015 mtx_unlock(&ps->ps_mtx); 2016 } else { 2017 /* 2018 * Avoid a possible infinite loop if the thread 2019 * masking the signal or process is ignoring the 2020 * signal. 2021 */ 2022 if (kern_forcesigexit && 2023 (SIGISMEMBER(td->td_sigmask, sig) || 2024 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2025 SIGDELSET(td->td_sigmask, sig); 2026 SIGDELSET(ps->ps_sigcatch, sig); 2027 SIGDELSET(ps->ps_sigignore, sig); 2028 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2029 } 2030 mtx_unlock(&ps->ps_mtx); 2031 p->p_sig = sig; /* XXX to verify code */ 2032 tdsendsignal(p, td, sig, ksi); 2033 } 2034 PROC_UNLOCK(p); 2035 } 2036 2037 static struct thread * 2038 sigtd(struct proc *p, int sig, int prop) 2039 { 2040 struct thread *td, *signal_td; 2041 2042 PROC_LOCK_ASSERT(p, MA_OWNED); 2043 2044 /* 2045 * Check if current thread can handle the signal without 2046 * switching context to another thread. 2047 */ 2048 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2049 return (curthread); 2050 signal_td = NULL; 2051 FOREACH_THREAD_IN_PROC(p, td) { 2052 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2053 signal_td = td; 2054 break; 2055 } 2056 } 2057 if (signal_td == NULL) 2058 signal_td = FIRST_THREAD_IN_PROC(p); 2059 return (signal_td); 2060 } 2061 2062 /* 2063 * Send the signal to the process. If the signal has an action, the action 2064 * is usually performed by the target process rather than the caller; we add 2065 * the signal to the set of pending signals for the process. 2066 * 2067 * Exceptions: 2068 * o When a stop signal is sent to a sleeping process that takes the 2069 * default action, the process is stopped without awakening it. 2070 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2071 * regardless of the signal action (eg, blocked or ignored). 2072 * 2073 * Other ignored signals are discarded immediately. 2074 * 2075 * NB: This function may be entered from the debugger via the "kill" DDB 2076 * command. There is little that can be done to mitigate the possibly messy 2077 * side effects of this unwise possibility. 2078 */ 2079 void 2080 kern_psignal(struct proc *p, int sig) 2081 { 2082 ksiginfo_t ksi; 2083 2084 ksiginfo_init(&ksi); 2085 ksi.ksi_signo = sig; 2086 ksi.ksi_code = SI_KERNEL; 2087 (void) tdsendsignal(p, NULL, sig, &ksi); 2088 } 2089 2090 int 2091 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2092 { 2093 2094 return (tdsendsignal(p, NULL, sig, ksi)); 2095 } 2096 2097 /* Utility function for finding a thread to send signal event to. */ 2098 int 2099 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2100 { 2101 struct thread *td; 2102 2103 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2104 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2105 if (td == NULL) 2106 return (ESRCH); 2107 *ttd = td; 2108 } else { 2109 *ttd = NULL; 2110 PROC_LOCK(p); 2111 } 2112 return (0); 2113 } 2114 2115 void 2116 tdsignal(struct thread *td, int sig) 2117 { 2118 ksiginfo_t ksi; 2119 2120 ksiginfo_init(&ksi); 2121 ksi.ksi_signo = sig; 2122 ksi.ksi_code = SI_KERNEL; 2123 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2124 } 2125 2126 void 2127 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2128 { 2129 2130 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2131 } 2132 2133 int 2134 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2135 { 2136 sig_t action; 2137 sigqueue_t *sigqueue; 2138 int prop; 2139 struct sigacts *ps; 2140 int intrval; 2141 int ret = 0; 2142 int wakeup_swapper; 2143 2144 MPASS(td == NULL || p == td->td_proc); 2145 PROC_LOCK_ASSERT(p, MA_OWNED); 2146 2147 if (!_SIG_VALID(sig)) 2148 panic("%s(): invalid signal %d", __func__, sig); 2149 2150 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2151 2152 /* 2153 * IEEE Std 1003.1-2001: return success when killing a zombie. 2154 */ 2155 if (p->p_state == PRS_ZOMBIE) { 2156 if (ksi && (ksi->ksi_flags & KSI_INS)) 2157 ksiginfo_tryfree(ksi); 2158 return (ret); 2159 } 2160 2161 ps = p->p_sigacts; 2162 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2163 prop = sigprop(sig); 2164 2165 if (td == NULL) { 2166 td = sigtd(p, sig, prop); 2167 sigqueue = &p->p_sigqueue; 2168 } else 2169 sigqueue = &td->td_sigqueue; 2170 2171 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2172 2173 /* 2174 * If the signal is being ignored, 2175 * then we forget about it immediately. 2176 * (Note: we don't set SIGCONT in ps_sigignore, 2177 * and if it is set to SIG_IGN, 2178 * action will be SIG_DFL here.) 2179 */ 2180 mtx_lock(&ps->ps_mtx); 2181 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2182 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2183 2184 mtx_unlock(&ps->ps_mtx); 2185 if (ksi && (ksi->ksi_flags & KSI_INS)) 2186 ksiginfo_tryfree(ksi); 2187 return (ret); 2188 } 2189 if (SIGISMEMBER(td->td_sigmask, sig)) 2190 action = SIG_HOLD; 2191 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2192 action = SIG_CATCH; 2193 else 2194 action = SIG_DFL; 2195 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2196 intrval = EINTR; 2197 else 2198 intrval = ERESTART; 2199 mtx_unlock(&ps->ps_mtx); 2200 2201 if (prop & SIGPROP_CONT) 2202 sigqueue_delete_stopmask_proc(p); 2203 else if (prop & SIGPROP_STOP) { 2204 /* 2205 * If sending a tty stop signal to a member of an orphaned 2206 * process group, discard the signal here if the action 2207 * is default; don't stop the process below if sleeping, 2208 * and don't clear any pending SIGCONT. 2209 */ 2210 if ((prop & SIGPROP_TTYSTOP) && 2211 (p->p_pgrp->pg_jobc == 0) && 2212 (action == SIG_DFL)) { 2213 if (ksi && (ksi->ksi_flags & KSI_INS)) 2214 ksiginfo_tryfree(ksi); 2215 return (ret); 2216 } 2217 sigqueue_delete_proc(p, SIGCONT); 2218 if (p->p_flag & P_CONTINUED) { 2219 p->p_flag &= ~P_CONTINUED; 2220 PROC_LOCK(p->p_pptr); 2221 sigqueue_take(p->p_ksi); 2222 PROC_UNLOCK(p->p_pptr); 2223 } 2224 } 2225 2226 ret = sigqueue_add(sigqueue, sig, ksi); 2227 if (ret != 0) 2228 return (ret); 2229 signotify(td); 2230 /* 2231 * Defer further processing for signals which are held, 2232 * except that stopped processes must be continued by SIGCONT. 2233 */ 2234 if (action == SIG_HOLD && 2235 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2236 return (ret); 2237 2238 /* SIGKILL: Remove procfs STOPEVENTs. */ 2239 if (sig == SIGKILL) { 2240 /* from procfs_ioctl.c: PIOCBIC */ 2241 p->p_stops = 0; 2242 /* from procfs_ioctl.c: PIOCCONT */ 2243 p->p_step = 0; 2244 wakeup(&p->p_step); 2245 } 2246 /* 2247 * Some signals have a process-wide effect and a per-thread 2248 * component. Most processing occurs when the process next 2249 * tries to cross the user boundary, however there are some 2250 * times when processing needs to be done immediately, such as 2251 * waking up threads so that they can cross the user boundary. 2252 * We try to do the per-process part here. 2253 */ 2254 if (P_SHOULDSTOP(p)) { 2255 KASSERT(!(p->p_flag & P_WEXIT), 2256 ("signal to stopped but exiting process")); 2257 if (sig == SIGKILL) { 2258 /* 2259 * If traced process is already stopped, 2260 * then no further action is necessary. 2261 */ 2262 if (p->p_flag & P_TRACED) 2263 goto out; 2264 /* 2265 * SIGKILL sets process running. 2266 * It will die elsewhere. 2267 * All threads must be restarted. 2268 */ 2269 p->p_flag &= ~P_STOPPED_SIG; 2270 goto runfast; 2271 } 2272 2273 if (prop & SIGPROP_CONT) { 2274 /* 2275 * If traced process is already stopped, 2276 * then no further action is necessary. 2277 */ 2278 if (p->p_flag & P_TRACED) 2279 goto out; 2280 /* 2281 * If SIGCONT is default (or ignored), we continue the 2282 * process but don't leave the signal in sigqueue as 2283 * it has no further action. If SIGCONT is held, we 2284 * continue the process and leave the signal in 2285 * sigqueue. If the process catches SIGCONT, let it 2286 * handle the signal itself. If it isn't waiting on 2287 * an event, it goes back to run state. 2288 * Otherwise, process goes back to sleep state. 2289 */ 2290 p->p_flag &= ~P_STOPPED_SIG; 2291 PROC_SLOCK(p); 2292 if (p->p_numthreads == p->p_suspcount) { 2293 PROC_SUNLOCK(p); 2294 p->p_flag |= P_CONTINUED; 2295 p->p_xsig = SIGCONT; 2296 PROC_LOCK(p->p_pptr); 2297 childproc_continued(p); 2298 PROC_UNLOCK(p->p_pptr); 2299 PROC_SLOCK(p); 2300 } 2301 if (action == SIG_DFL) { 2302 thread_unsuspend(p); 2303 PROC_SUNLOCK(p); 2304 sigqueue_delete(sigqueue, sig); 2305 goto out; 2306 } 2307 if (action == SIG_CATCH) { 2308 /* 2309 * The process wants to catch it so it needs 2310 * to run at least one thread, but which one? 2311 */ 2312 PROC_SUNLOCK(p); 2313 goto runfast; 2314 } 2315 /* 2316 * The signal is not ignored or caught. 2317 */ 2318 thread_unsuspend(p); 2319 PROC_SUNLOCK(p); 2320 goto out; 2321 } 2322 2323 if (prop & SIGPROP_STOP) { 2324 /* 2325 * If traced process is already stopped, 2326 * then no further action is necessary. 2327 */ 2328 if (p->p_flag & P_TRACED) 2329 goto out; 2330 /* 2331 * Already stopped, don't need to stop again 2332 * (If we did the shell could get confused). 2333 * Just make sure the signal STOP bit set. 2334 */ 2335 p->p_flag |= P_STOPPED_SIG; 2336 sigqueue_delete(sigqueue, sig); 2337 goto out; 2338 } 2339 2340 /* 2341 * All other kinds of signals: 2342 * If a thread is sleeping interruptibly, simulate a 2343 * wakeup so that when it is continued it will be made 2344 * runnable and can look at the signal. However, don't make 2345 * the PROCESS runnable, leave it stopped. 2346 * It may run a bit until it hits a thread_suspend_check(). 2347 */ 2348 wakeup_swapper = 0; 2349 PROC_SLOCK(p); 2350 thread_lock(td); 2351 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2352 wakeup_swapper = sleepq_abort(td, intrval); 2353 thread_unlock(td); 2354 PROC_SUNLOCK(p); 2355 if (wakeup_swapper) 2356 kick_proc0(); 2357 goto out; 2358 /* 2359 * Mutexes are short lived. Threads waiting on them will 2360 * hit thread_suspend_check() soon. 2361 */ 2362 } else if (p->p_state == PRS_NORMAL) { 2363 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2364 tdsigwakeup(td, sig, action, intrval); 2365 goto out; 2366 } 2367 2368 MPASS(action == SIG_DFL); 2369 2370 if (prop & SIGPROP_STOP) { 2371 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2372 goto out; 2373 p->p_flag |= P_STOPPED_SIG; 2374 p->p_xsig = sig; 2375 PROC_SLOCK(p); 2376 wakeup_swapper = sig_suspend_threads(td, p, 1); 2377 if (p->p_numthreads == p->p_suspcount) { 2378 /* 2379 * only thread sending signal to another 2380 * process can reach here, if thread is sending 2381 * signal to its process, because thread does 2382 * not suspend itself here, p_numthreads 2383 * should never be equal to p_suspcount. 2384 */ 2385 thread_stopped(p); 2386 PROC_SUNLOCK(p); 2387 sigqueue_delete_proc(p, p->p_xsig); 2388 } else 2389 PROC_SUNLOCK(p); 2390 if (wakeup_swapper) 2391 kick_proc0(); 2392 goto out; 2393 } 2394 } else { 2395 /* Not in "NORMAL" state. discard the signal. */ 2396 sigqueue_delete(sigqueue, sig); 2397 goto out; 2398 } 2399 2400 /* 2401 * The process is not stopped so we need to apply the signal to all the 2402 * running threads. 2403 */ 2404 runfast: 2405 tdsigwakeup(td, sig, action, intrval); 2406 PROC_SLOCK(p); 2407 thread_unsuspend(p); 2408 PROC_SUNLOCK(p); 2409 out: 2410 /* If we jump here, proc slock should not be owned. */ 2411 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2412 return (ret); 2413 } 2414 2415 /* 2416 * The force of a signal has been directed against a single 2417 * thread. We need to see what we can do about knocking it 2418 * out of any sleep it may be in etc. 2419 */ 2420 static void 2421 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2422 { 2423 struct proc *p = td->td_proc; 2424 int prop; 2425 int wakeup_swapper; 2426 2427 wakeup_swapper = 0; 2428 PROC_LOCK_ASSERT(p, MA_OWNED); 2429 prop = sigprop(sig); 2430 2431 PROC_SLOCK(p); 2432 thread_lock(td); 2433 /* 2434 * Bring the priority of a thread up if we want it to get 2435 * killed in this lifetime. Be careful to avoid bumping the 2436 * priority of the idle thread, since we still allow to signal 2437 * kernel processes. 2438 */ 2439 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2440 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2441 sched_prio(td, PUSER); 2442 if (TD_ON_SLEEPQ(td)) { 2443 /* 2444 * If thread is sleeping uninterruptibly 2445 * we can't interrupt the sleep... the signal will 2446 * be noticed when the process returns through 2447 * trap() or syscall(). 2448 */ 2449 if ((td->td_flags & TDF_SINTR) == 0) 2450 goto out; 2451 /* 2452 * If SIGCONT is default (or ignored) and process is 2453 * asleep, we are finished; the process should not 2454 * be awakened. 2455 */ 2456 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2457 thread_unlock(td); 2458 PROC_SUNLOCK(p); 2459 sigqueue_delete(&p->p_sigqueue, sig); 2460 /* 2461 * It may be on either list in this state. 2462 * Remove from both for now. 2463 */ 2464 sigqueue_delete(&td->td_sigqueue, sig); 2465 return; 2466 } 2467 2468 /* 2469 * Don't awaken a sleeping thread for SIGSTOP if the 2470 * STOP signal is deferred. 2471 */ 2472 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2473 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2474 goto out; 2475 2476 /* 2477 * Give low priority threads a better chance to run. 2478 */ 2479 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2480 sched_prio(td, PUSER); 2481 2482 wakeup_swapper = sleepq_abort(td, intrval); 2483 } else { 2484 /* 2485 * Other states do nothing with the signal immediately, 2486 * other than kicking ourselves if we are running. 2487 * It will either never be noticed, or noticed very soon. 2488 */ 2489 #ifdef SMP 2490 if (TD_IS_RUNNING(td) && td != curthread) 2491 forward_signal(td); 2492 #endif 2493 } 2494 out: 2495 PROC_SUNLOCK(p); 2496 thread_unlock(td); 2497 if (wakeup_swapper) 2498 kick_proc0(); 2499 } 2500 2501 static int 2502 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2503 { 2504 struct thread *td2; 2505 int wakeup_swapper; 2506 2507 PROC_LOCK_ASSERT(p, MA_OWNED); 2508 PROC_SLOCK_ASSERT(p, MA_OWNED); 2509 MPASS(sending || td == curthread); 2510 2511 wakeup_swapper = 0; 2512 FOREACH_THREAD_IN_PROC(p, td2) { 2513 thread_lock(td2); 2514 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2515 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2516 (td2->td_flags & TDF_SINTR)) { 2517 if (td2->td_flags & TDF_SBDRY) { 2518 /* 2519 * Once a thread is asleep with 2520 * TDF_SBDRY and without TDF_SERESTART 2521 * or TDF_SEINTR set, it should never 2522 * become suspended due to this check. 2523 */ 2524 KASSERT(!TD_IS_SUSPENDED(td2), 2525 ("thread with deferred stops suspended")); 2526 if (TD_SBDRY_INTR(td2)) 2527 wakeup_swapper |= sleepq_abort(td2, 2528 TD_SBDRY_ERRNO(td2)); 2529 } else if (!TD_IS_SUSPENDED(td2)) { 2530 thread_suspend_one(td2); 2531 } 2532 } else if (!TD_IS_SUSPENDED(td2)) { 2533 if (sending || td != td2) 2534 td2->td_flags |= TDF_ASTPENDING; 2535 #ifdef SMP 2536 if (TD_IS_RUNNING(td2) && td2 != td) 2537 forward_signal(td2); 2538 #endif 2539 } 2540 thread_unlock(td2); 2541 } 2542 return (wakeup_swapper); 2543 } 2544 2545 /* 2546 * Stop the process for an event deemed interesting to the debugger. If si is 2547 * non-NULL, this is a signal exchange; the new signal requested by the 2548 * debugger will be returned for handling. If si is NULL, this is some other 2549 * type of interesting event. The debugger may request a signal be delivered in 2550 * that case as well, however it will be deferred until it can be handled. 2551 */ 2552 int 2553 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2554 { 2555 struct proc *p = td->td_proc; 2556 struct thread *td2; 2557 ksiginfo_t ksi; 2558 int prop; 2559 2560 PROC_LOCK_ASSERT(p, MA_OWNED); 2561 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2562 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2563 &p->p_mtx.lock_object, "Stopping for traced signal"); 2564 2565 td->td_xsig = sig; 2566 2567 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2568 td->td_dbgflags |= TDB_XSIG; 2569 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2570 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2571 PROC_SLOCK(p); 2572 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2573 if (P_KILLED(p)) { 2574 /* 2575 * Ensure that, if we've been PT_KILLed, the 2576 * exit status reflects that. Another thread 2577 * may also be in ptracestop(), having just 2578 * received the SIGKILL, but this thread was 2579 * unsuspended first. 2580 */ 2581 td->td_dbgflags &= ~TDB_XSIG; 2582 td->td_xsig = SIGKILL; 2583 p->p_ptevents = 0; 2584 break; 2585 } 2586 if (p->p_flag & P_SINGLE_EXIT && 2587 !(td->td_dbgflags & TDB_EXIT)) { 2588 /* 2589 * Ignore ptrace stops except for thread exit 2590 * events when the process exits. 2591 */ 2592 td->td_dbgflags &= ~TDB_XSIG; 2593 PROC_SUNLOCK(p); 2594 return (0); 2595 } 2596 2597 /* 2598 * Make wait(2) work. Ensure that right after the 2599 * attach, the thread which was decided to become the 2600 * leader of attach gets reported to the waiter. 2601 * Otherwise, just avoid overwriting another thread's 2602 * assignment to p_xthread. If another thread has 2603 * already set p_xthread, the current thread will get 2604 * a chance to report itself upon the next iteration. 2605 */ 2606 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2607 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2608 p->p_xthread == NULL)) { 2609 p->p_xsig = sig; 2610 p->p_xthread = td; 2611 2612 /* 2613 * If we are on sleepqueue already, 2614 * let sleepqueue code decide if it 2615 * needs to go sleep after attach. 2616 */ 2617 if (td->td_wchan == NULL) 2618 td->td_dbgflags &= ~TDB_FSTP; 2619 2620 p->p_flag2 &= ~P2_PTRACE_FSTP; 2621 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2622 sig_suspend_threads(td, p, 0); 2623 } 2624 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2625 td->td_dbgflags &= ~TDB_STOPATFORK; 2626 } 2627 stopme: 2628 thread_suspend_switch(td, p); 2629 if (p->p_xthread == td) 2630 p->p_xthread = NULL; 2631 if (!(p->p_flag & P_TRACED)) 2632 break; 2633 if (td->td_dbgflags & TDB_SUSPEND) { 2634 if (p->p_flag & P_SINGLE_EXIT) 2635 break; 2636 goto stopme; 2637 } 2638 } 2639 PROC_SUNLOCK(p); 2640 } 2641 2642 if (si != NULL && sig == td->td_xsig) { 2643 /* Parent wants us to take the original signal unchanged. */ 2644 si->ksi_flags |= KSI_HEAD; 2645 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2646 si->ksi_signo = 0; 2647 } else if (td->td_xsig != 0) { 2648 /* 2649 * If parent wants us to take a new signal, then it will leave 2650 * it in td->td_xsig; otherwise we just look for signals again. 2651 */ 2652 ksiginfo_init(&ksi); 2653 ksi.ksi_signo = td->td_xsig; 2654 ksi.ksi_flags |= KSI_PTRACE; 2655 prop = sigprop(td->td_xsig); 2656 td2 = sigtd(p, td->td_xsig, prop); 2657 tdsendsignal(p, td2, td->td_xsig, &ksi); 2658 if (td != td2) 2659 return (0); 2660 } 2661 2662 return (td->td_xsig); 2663 } 2664 2665 static void 2666 reschedule_signals(struct proc *p, sigset_t block, int flags) 2667 { 2668 struct sigacts *ps; 2669 struct thread *td; 2670 int sig; 2671 2672 PROC_LOCK_ASSERT(p, MA_OWNED); 2673 ps = p->p_sigacts; 2674 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2675 MA_OWNED : MA_NOTOWNED); 2676 if (SIGISEMPTY(p->p_siglist)) 2677 return; 2678 SIGSETAND(block, p->p_siglist); 2679 while ((sig = sig_ffs(&block)) != 0) { 2680 SIGDELSET(block, sig); 2681 td = sigtd(p, sig, 0); 2682 signotify(td); 2683 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2684 mtx_lock(&ps->ps_mtx); 2685 if (p->p_flag & P_TRACED || 2686 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2687 !SIGISMEMBER(td->td_sigmask, sig))) 2688 tdsigwakeup(td, sig, SIG_CATCH, 2689 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2690 ERESTART)); 2691 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2692 mtx_unlock(&ps->ps_mtx); 2693 } 2694 } 2695 2696 void 2697 tdsigcleanup(struct thread *td) 2698 { 2699 struct proc *p; 2700 sigset_t unblocked; 2701 2702 p = td->td_proc; 2703 PROC_LOCK_ASSERT(p, MA_OWNED); 2704 2705 sigqueue_flush(&td->td_sigqueue); 2706 if (p->p_numthreads == 1) 2707 return; 2708 2709 /* 2710 * Since we cannot handle signals, notify signal post code 2711 * about this by filling the sigmask. 2712 * 2713 * Also, if needed, wake up thread(s) that do not block the 2714 * same signals as the exiting thread, since the thread might 2715 * have been selected for delivery and woken up. 2716 */ 2717 SIGFILLSET(unblocked); 2718 SIGSETNAND(unblocked, td->td_sigmask); 2719 SIGFILLSET(td->td_sigmask); 2720 reschedule_signals(p, unblocked, 0); 2721 2722 } 2723 2724 static int 2725 sigdeferstop_curr_flags(int cflags) 2726 { 2727 2728 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2729 (cflags & TDF_SBDRY) != 0); 2730 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2731 } 2732 2733 /* 2734 * Defer the delivery of SIGSTOP for the current thread, according to 2735 * the requested mode. Returns previous flags, which must be restored 2736 * by sigallowstop(). 2737 * 2738 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2739 * cleared by the current thread, which allow the lock-less read-only 2740 * accesses below. 2741 */ 2742 int 2743 sigdeferstop_impl(int mode) 2744 { 2745 struct thread *td; 2746 int cflags, nflags; 2747 2748 td = curthread; 2749 cflags = sigdeferstop_curr_flags(td->td_flags); 2750 switch (mode) { 2751 case SIGDEFERSTOP_NOP: 2752 nflags = cflags; 2753 break; 2754 case SIGDEFERSTOP_OFF: 2755 nflags = 0; 2756 break; 2757 case SIGDEFERSTOP_SILENT: 2758 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2759 break; 2760 case SIGDEFERSTOP_EINTR: 2761 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2762 break; 2763 case SIGDEFERSTOP_ERESTART: 2764 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2765 break; 2766 default: 2767 panic("sigdeferstop: invalid mode %x", mode); 2768 break; 2769 } 2770 if (cflags == nflags) 2771 return (SIGDEFERSTOP_VAL_NCHG); 2772 thread_lock(td); 2773 td->td_flags = (td->td_flags & ~cflags) | nflags; 2774 thread_unlock(td); 2775 return (cflags); 2776 } 2777 2778 /* 2779 * Restores the STOP handling mode, typically permitting the delivery 2780 * of SIGSTOP for the current thread. This does not immediately 2781 * suspend if a stop was posted. Instead, the thread will suspend 2782 * either via ast() or a subsequent interruptible sleep. 2783 */ 2784 void 2785 sigallowstop_impl(int prev) 2786 { 2787 struct thread *td; 2788 int cflags; 2789 2790 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2791 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2792 ("sigallowstop: incorrect previous mode %x", prev)); 2793 td = curthread; 2794 cflags = sigdeferstop_curr_flags(td->td_flags); 2795 if (cflags != prev) { 2796 thread_lock(td); 2797 td->td_flags = (td->td_flags & ~cflags) | prev; 2798 thread_unlock(td); 2799 } 2800 } 2801 2802 /* 2803 * If the current process has received a signal (should be caught or cause 2804 * termination, should interrupt current syscall), return the signal number. 2805 * Stop signals with default action are processed immediately, then cleared; 2806 * they aren't returned. This is checked after each entry to the system for 2807 * a syscall or trap (though this can usually be done without calling issignal 2808 * by checking the pending signal masks in cursig.) The normal call 2809 * sequence is 2810 * 2811 * while (sig = cursig(curthread)) 2812 * postsig(sig); 2813 */ 2814 static int 2815 issignal(struct thread *td) 2816 { 2817 struct proc *p; 2818 struct sigacts *ps; 2819 struct sigqueue *queue; 2820 sigset_t sigpending; 2821 ksiginfo_t ksi; 2822 int prop, sig, traced; 2823 2824 p = td->td_proc; 2825 ps = p->p_sigacts; 2826 mtx_assert(&ps->ps_mtx, MA_OWNED); 2827 PROC_LOCK_ASSERT(p, MA_OWNED); 2828 for (;;) { 2829 traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2830 2831 sigpending = td->td_sigqueue.sq_signals; 2832 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2833 SIGSETNAND(sigpending, td->td_sigmask); 2834 2835 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2836 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2837 SIG_STOPSIGMASK(sigpending); 2838 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2839 return (0); 2840 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2841 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2842 SIGISMEMBER(sigpending, SIGSTOP)) { 2843 /* 2844 * If debugger just attached, always consume 2845 * SIGSTOP from ptrace(PT_ATTACH) first, to 2846 * execute the debugger attach ritual in 2847 * order. 2848 */ 2849 sig = SIGSTOP; 2850 td->td_dbgflags |= TDB_FSTP; 2851 } else { 2852 sig = sig_ffs(&sigpending); 2853 } 2854 2855 if (p->p_stops & S_SIG) { 2856 mtx_unlock(&ps->ps_mtx); 2857 stopevent(p, S_SIG, sig); 2858 mtx_lock(&ps->ps_mtx); 2859 } 2860 2861 /* 2862 * We should see pending but ignored signals 2863 * only if P_TRACED was on when they were posted. 2864 */ 2865 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2866 sigqueue_delete(&td->td_sigqueue, sig); 2867 sigqueue_delete(&p->p_sigqueue, sig); 2868 continue; 2869 } 2870 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2871 /* 2872 * If traced, always stop. 2873 * Remove old signal from queue before the stop. 2874 * XXX shrug off debugger, it causes siginfo to 2875 * be thrown away. 2876 */ 2877 queue = &td->td_sigqueue; 2878 ksiginfo_init(&ksi); 2879 if (sigqueue_get(queue, sig, &ksi) == 0) { 2880 queue = &p->p_sigqueue; 2881 sigqueue_get(queue, sig, &ksi); 2882 } 2883 td->td_si = ksi.ksi_info; 2884 2885 mtx_unlock(&ps->ps_mtx); 2886 sig = ptracestop(td, sig, &ksi); 2887 mtx_lock(&ps->ps_mtx); 2888 2889 td->td_si.si_signo = 0; 2890 2891 /* 2892 * Keep looking if the debugger discarded or 2893 * replaced the signal. 2894 */ 2895 if (sig == 0) 2896 continue; 2897 2898 /* 2899 * If the signal became masked, re-queue it. 2900 */ 2901 if (SIGISMEMBER(td->td_sigmask, sig)) { 2902 ksi.ksi_flags |= KSI_HEAD; 2903 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2904 continue; 2905 } 2906 2907 /* 2908 * If the traced bit got turned off, requeue 2909 * the signal and go back up to the top to 2910 * rescan signals. This ensures that p_sig* 2911 * and p_sigact are consistent. 2912 */ 2913 if ((p->p_flag & P_TRACED) == 0) { 2914 ksi.ksi_flags |= KSI_HEAD; 2915 sigqueue_add(queue, sig, &ksi); 2916 continue; 2917 } 2918 } 2919 2920 prop = sigprop(sig); 2921 2922 /* 2923 * Decide whether the signal should be returned. 2924 * Return the signal's number, or fall through 2925 * to clear it from the pending mask. 2926 */ 2927 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2928 2929 case (intptr_t)SIG_DFL: 2930 /* 2931 * Don't take default actions on system processes. 2932 */ 2933 if (p->p_pid <= 1) { 2934 #ifdef DIAGNOSTIC 2935 /* 2936 * Are you sure you want to ignore SIGSEGV 2937 * in init? XXX 2938 */ 2939 printf("Process (pid %lu) got signal %d\n", 2940 (u_long)p->p_pid, sig); 2941 #endif 2942 break; /* == ignore */ 2943 } 2944 /* 2945 * If there is a pending stop signal to process with 2946 * default action, stop here, then clear the signal. 2947 * Traced or exiting processes should ignore stops. 2948 * Additionally, a member of an orphaned process group 2949 * should ignore tty stops. 2950 */ 2951 if (prop & SIGPROP_STOP) { 2952 if (p->p_flag & 2953 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 2954 (p->p_pgrp->pg_jobc == 0 && 2955 prop & SIGPROP_TTYSTOP)) 2956 break; /* == ignore */ 2957 if (TD_SBDRY_INTR(td)) { 2958 KASSERT((td->td_flags & TDF_SBDRY) != 0, 2959 ("lost TDF_SBDRY")); 2960 return (-1); 2961 } 2962 mtx_unlock(&ps->ps_mtx); 2963 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2964 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2965 sigqueue_delete(&td->td_sigqueue, sig); 2966 sigqueue_delete(&p->p_sigqueue, sig); 2967 p->p_flag |= P_STOPPED_SIG; 2968 p->p_xsig = sig; 2969 PROC_SLOCK(p); 2970 sig_suspend_threads(td, p, 0); 2971 thread_suspend_switch(td, p); 2972 PROC_SUNLOCK(p); 2973 mtx_lock(&ps->ps_mtx); 2974 goto next; 2975 } else if (prop & SIGPROP_IGNORE) { 2976 /* 2977 * Except for SIGCONT, shouldn't get here. 2978 * Default action is to ignore; drop it. 2979 */ 2980 break; /* == ignore */ 2981 } else 2982 return (sig); 2983 /*NOTREACHED*/ 2984 2985 case (intptr_t)SIG_IGN: 2986 /* 2987 * Masking above should prevent us ever trying 2988 * to take action on an ignored signal other 2989 * than SIGCONT, unless process is traced. 2990 */ 2991 if ((prop & SIGPROP_CONT) == 0 && 2992 (p->p_flag & P_TRACED) == 0) 2993 printf("issignal\n"); 2994 break; /* == ignore */ 2995 2996 default: 2997 /* 2998 * This signal has an action, let 2999 * postsig() process it. 3000 */ 3001 return (sig); 3002 } 3003 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 3004 sigqueue_delete(&p->p_sigqueue, sig); 3005 next:; 3006 } 3007 /* NOTREACHED */ 3008 } 3009 3010 void 3011 thread_stopped(struct proc *p) 3012 { 3013 int n; 3014 3015 PROC_LOCK_ASSERT(p, MA_OWNED); 3016 PROC_SLOCK_ASSERT(p, MA_OWNED); 3017 n = p->p_suspcount; 3018 if (p == curproc) 3019 n++; 3020 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 3021 PROC_SUNLOCK(p); 3022 p->p_flag &= ~P_WAITED; 3023 PROC_LOCK(p->p_pptr); 3024 childproc_stopped(p, (p->p_flag & P_TRACED) ? 3025 CLD_TRAPPED : CLD_STOPPED); 3026 PROC_UNLOCK(p->p_pptr); 3027 PROC_SLOCK(p); 3028 } 3029 } 3030 3031 /* 3032 * Take the action for the specified signal 3033 * from the current set of pending signals. 3034 */ 3035 int 3036 postsig(int sig) 3037 { 3038 struct thread *td; 3039 struct proc *p; 3040 struct sigacts *ps; 3041 sig_t action; 3042 ksiginfo_t ksi; 3043 sigset_t returnmask; 3044 3045 KASSERT(sig != 0, ("postsig")); 3046 3047 td = curthread; 3048 p = td->td_proc; 3049 PROC_LOCK_ASSERT(p, MA_OWNED); 3050 ps = p->p_sigacts; 3051 mtx_assert(&ps->ps_mtx, MA_OWNED); 3052 ksiginfo_init(&ksi); 3053 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3054 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3055 return (0); 3056 ksi.ksi_signo = sig; 3057 if (ksi.ksi_code == SI_TIMER) 3058 itimer_accept(p, ksi.ksi_timerid, &ksi); 3059 action = ps->ps_sigact[_SIG_IDX(sig)]; 3060 #ifdef KTRACE 3061 if (KTRPOINT(td, KTR_PSIG)) 3062 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3063 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3064 #endif 3065 if ((p->p_stops & S_SIG) != 0) { 3066 mtx_unlock(&ps->ps_mtx); 3067 stopevent(p, S_SIG, sig); 3068 mtx_lock(&ps->ps_mtx); 3069 } 3070 3071 if (action == SIG_DFL) { 3072 /* 3073 * Default action, where the default is to kill 3074 * the process. (Other cases were ignored above.) 3075 */ 3076 mtx_unlock(&ps->ps_mtx); 3077 proc_td_siginfo_capture(td, &ksi.ksi_info); 3078 sigexit(td, sig); 3079 /* NOTREACHED */ 3080 } else { 3081 /* 3082 * If we get here, the signal must be caught. 3083 */ 3084 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3085 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3086 ("postsig action: blocked sig %d", sig)); 3087 3088 /* 3089 * Set the new mask value and also defer further 3090 * occurrences of this signal. 3091 * 3092 * Special case: user has done a sigsuspend. Here the 3093 * current mask is not of interest, but rather the 3094 * mask from before the sigsuspend is what we want 3095 * restored after the signal processing is completed. 3096 */ 3097 if (td->td_pflags & TDP_OLDMASK) { 3098 returnmask = td->td_oldsigmask; 3099 td->td_pflags &= ~TDP_OLDMASK; 3100 } else 3101 returnmask = td->td_sigmask; 3102 3103 if (p->p_sig == sig) { 3104 p->p_sig = 0; 3105 } 3106 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3107 postsig_done(sig, td, ps); 3108 } 3109 return (1); 3110 } 3111 3112 void 3113 proc_wkilled(struct proc *p) 3114 { 3115 3116 PROC_LOCK_ASSERT(p, MA_OWNED); 3117 if ((p->p_flag & P_WKILLED) == 0) { 3118 p->p_flag |= P_WKILLED; 3119 /* 3120 * Notify swapper that there is a process to swap in. 3121 * The notification is racy, at worst it would take 10 3122 * seconds for the swapper process to notice. 3123 */ 3124 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3125 wakeup(&proc0); 3126 } 3127 } 3128 3129 /* 3130 * Kill the current process for stated reason. 3131 */ 3132 void 3133 killproc(struct proc *p, char *why) 3134 { 3135 3136 PROC_LOCK_ASSERT(p, MA_OWNED); 3137 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3138 p->p_comm); 3139 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3140 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3141 p->p_ucred->cr_uid, why); 3142 proc_wkilled(p); 3143 kern_psignal(p, SIGKILL); 3144 } 3145 3146 /* 3147 * Force the current process to exit with the specified signal, dumping core 3148 * if appropriate. We bypass the normal tests for masked and caught signals, 3149 * allowing unrecoverable failures to terminate the process without changing 3150 * signal state. Mark the accounting record with the signal termination. 3151 * If dumping core, save the signal number for the debugger. Calls exit and 3152 * does not return. 3153 */ 3154 void 3155 sigexit(struct thread *td, int sig) 3156 { 3157 struct proc *p = td->td_proc; 3158 3159 PROC_LOCK_ASSERT(p, MA_OWNED); 3160 p->p_acflag |= AXSIG; 3161 /* 3162 * We must be single-threading to generate a core dump. This 3163 * ensures that the registers in the core file are up-to-date. 3164 * Also, the ELF dump handler assumes that the thread list doesn't 3165 * change out from under it. 3166 * 3167 * XXX If another thread attempts to single-thread before us 3168 * (e.g. via fork()), we won't get a dump at all. 3169 */ 3170 if ((sigprop(sig) & SIGPROP_CORE) && 3171 thread_single(p, SINGLE_NO_EXIT) == 0) { 3172 p->p_sig = sig; 3173 /* 3174 * Log signals which would cause core dumps 3175 * (Log as LOG_INFO to appease those who don't want 3176 * these messages.) 3177 * XXX : Todo, as well as euid, write out ruid too 3178 * Note that coredump() drops proc lock. 3179 */ 3180 if (coredump(td) == 0) 3181 sig |= WCOREFLAG; 3182 if (kern_logsigexit) 3183 log(LOG_INFO, 3184 "pid %d (%s), jid %d, uid %d: exited on " 3185 "signal %d%s\n", p->p_pid, p->p_comm, 3186 p->p_ucred->cr_prison->pr_id, 3187 td->td_ucred->cr_uid, 3188 sig &~ WCOREFLAG, 3189 sig & WCOREFLAG ? " (core dumped)" : ""); 3190 } else 3191 PROC_UNLOCK(p); 3192 exit1(td, 0, sig); 3193 /* NOTREACHED */ 3194 } 3195 3196 /* 3197 * Send queued SIGCHLD to parent when child process's state 3198 * is changed. 3199 */ 3200 static void 3201 sigparent(struct proc *p, int reason, int status) 3202 { 3203 PROC_LOCK_ASSERT(p, MA_OWNED); 3204 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3205 3206 if (p->p_ksi != NULL) { 3207 p->p_ksi->ksi_signo = SIGCHLD; 3208 p->p_ksi->ksi_code = reason; 3209 p->p_ksi->ksi_status = status; 3210 p->p_ksi->ksi_pid = p->p_pid; 3211 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3212 if (KSI_ONQ(p->p_ksi)) 3213 return; 3214 } 3215 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3216 } 3217 3218 static void 3219 childproc_jobstate(struct proc *p, int reason, int sig) 3220 { 3221 struct sigacts *ps; 3222 3223 PROC_LOCK_ASSERT(p, MA_OWNED); 3224 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3225 3226 /* 3227 * Wake up parent sleeping in kern_wait(), also send 3228 * SIGCHLD to parent, but SIGCHLD does not guarantee 3229 * that parent will awake, because parent may masked 3230 * the signal. 3231 */ 3232 p->p_pptr->p_flag |= P_STATCHILD; 3233 wakeup(p->p_pptr); 3234 3235 ps = p->p_pptr->p_sigacts; 3236 mtx_lock(&ps->ps_mtx); 3237 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3238 mtx_unlock(&ps->ps_mtx); 3239 sigparent(p, reason, sig); 3240 } else 3241 mtx_unlock(&ps->ps_mtx); 3242 } 3243 3244 void 3245 childproc_stopped(struct proc *p, int reason) 3246 { 3247 3248 childproc_jobstate(p, reason, p->p_xsig); 3249 } 3250 3251 void 3252 childproc_continued(struct proc *p) 3253 { 3254 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3255 } 3256 3257 void 3258 childproc_exited(struct proc *p) 3259 { 3260 int reason, status; 3261 3262 if (WCOREDUMP(p->p_xsig)) { 3263 reason = CLD_DUMPED; 3264 status = WTERMSIG(p->p_xsig); 3265 } else if (WIFSIGNALED(p->p_xsig)) { 3266 reason = CLD_KILLED; 3267 status = WTERMSIG(p->p_xsig); 3268 } else { 3269 reason = CLD_EXITED; 3270 status = p->p_xexit; 3271 } 3272 /* 3273 * XXX avoid calling wakeup(p->p_pptr), the work is 3274 * done in exit1(). 3275 */ 3276 sigparent(p, reason, status); 3277 } 3278 3279 #define MAX_NUM_CORE_FILES 100000 3280 #ifndef NUM_CORE_FILES 3281 #define NUM_CORE_FILES 5 3282 #endif 3283 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3284 static int num_cores = NUM_CORE_FILES; 3285 3286 static int 3287 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3288 { 3289 int error; 3290 int new_val; 3291 3292 new_val = num_cores; 3293 error = sysctl_handle_int(oidp, &new_val, 0, req); 3294 if (error != 0 || req->newptr == NULL) 3295 return (error); 3296 if (new_val > MAX_NUM_CORE_FILES) 3297 new_val = MAX_NUM_CORE_FILES; 3298 if (new_val < 0) 3299 new_val = 0; 3300 num_cores = new_val; 3301 return (0); 3302 } 3303 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3304 0, sizeof(int), sysctl_debug_num_cores_check, "I", 3305 "Maximum number of generated process corefiles while using index format"); 3306 3307 #define GZIP_SUFFIX ".gz" 3308 #define ZSTD_SUFFIX ".zst" 3309 3310 int compress_user_cores = 0; 3311 3312 static int 3313 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3314 { 3315 int error, val; 3316 3317 val = compress_user_cores; 3318 error = sysctl_handle_int(oidp, &val, 0, req); 3319 if (error != 0 || req->newptr == NULL) 3320 return (error); 3321 if (val != 0 && !compressor_avail(val)) 3322 return (EINVAL); 3323 compress_user_cores = val; 3324 return (error); 3325 } 3326 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, CTLTYPE_INT | CTLFLAG_RWTUN, 3327 0, sizeof(int), sysctl_compress_user_cores, "I", 3328 "Enable compression of user corefiles (" 3329 __XSTRING(COMPRESS_GZIP) " = gzip, " 3330 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3331 3332 int compress_user_cores_level = 6; 3333 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3334 &compress_user_cores_level, 0, 3335 "Corefile compression level"); 3336 3337 /* 3338 * Protect the access to corefilename[] by allproc_lock. 3339 */ 3340 #define corefilename_lock allproc_lock 3341 3342 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3343 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3344 3345 static int 3346 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3347 { 3348 int error; 3349 3350 sx_xlock(&corefilename_lock); 3351 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3352 req); 3353 sx_xunlock(&corefilename_lock); 3354 3355 return (error); 3356 } 3357 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3358 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3359 "Process corefile name format string"); 3360 3361 static void 3362 vnode_close_locked(struct thread *td, struct vnode *vp) 3363 { 3364 3365 VOP_UNLOCK(vp, 0); 3366 vn_close(vp, FWRITE, td->td_ucred, td); 3367 } 3368 3369 /* 3370 * If the core format has a %I in it, then we need to check 3371 * for existing corefiles before defining a name. 3372 * To do this we iterate over 0..ncores to find a 3373 * non-existing core file name to use. If all core files are 3374 * already used we choose the oldest one. 3375 */ 3376 static int 3377 corefile_open_last(struct thread *td, char *name, int indexpos, 3378 int indexlen, int ncores, struct vnode **vpp) 3379 { 3380 struct vnode *oldvp, *nextvp, *vp; 3381 struct vattr vattr; 3382 struct nameidata nd; 3383 int error, i, flags, oflags, cmode; 3384 char ch; 3385 struct timespec lasttime; 3386 3387 nextvp = oldvp = NULL; 3388 cmode = S_IRUSR | S_IWUSR; 3389 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3390 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3391 3392 for (i = 0; i < ncores; i++) { 3393 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3394 3395 ch = name[indexpos + indexlen]; 3396 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3397 i); 3398 name[indexpos + indexlen] = ch; 3399 3400 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3401 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3402 NULL); 3403 if (error != 0) 3404 break; 3405 3406 vp = nd.ni_vp; 3407 NDFREE(&nd, NDF_ONLY_PNBUF); 3408 if ((flags & O_CREAT) == O_CREAT) { 3409 nextvp = vp; 3410 break; 3411 } 3412 3413 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3414 if (error != 0) { 3415 vnode_close_locked(td, vp); 3416 break; 3417 } 3418 3419 if (oldvp == NULL || 3420 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3421 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3422 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3423 if (oldvp != NULL) 3424 vnode_close_locked(td, oldvp); 3425 oldvp = vp; 3426 lasttime = vattr.va_mtime; 3427 } else { 3428 vnode_close_locked(td, vp); 3429 } 3430 } 3431 3432 if (oldvp != NULL) { 3433 if (nextvp == NULL) { 3434 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3435 error = EFAULT; 3436 vnode_close_locked(td, oldvp); 3437 } else { 3438 nextvp = oldvp; 3439 } 3440 } else { 3441 vnode_close_locked(td, oldvp); 3442 } 3443 } 3444 if (error != 0) { 3445 if (nextvp != NULL) 3446 vnode_close_locked(td, oldvp); 3447 } else { 3448 *vpp = nextvp; 3449 } 3450 3451 return (error); 3452 } 3453 3454 /* 3455 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3456 * Expand the name described in corefilename, using name, uid, and pid 3457 * and open/create core file. 3458 * corefilename is a printf-like string, with three format specifiers: 3459 * %N name of process ("name") 3460 * %P process id (pid) 3461 * %U user id (uid) 3462 * For example, "%N.core" is the default; they can be disabled completely 3463 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3464 * This is controlled by the sysctl variable kern.corefile (see above). 3465 */ 3466 static int 3467 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3468 int compress, int signum, struct vnode **vpp, char **namep) 3469 { 3470 struct sbuf sb; 3471 struct nameidata nd; 3472 const char *format; 3473 char *hostname, *name; 3474 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3475 3476 hostname = NULL; 3477 format = corefilename; 3478 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3479 indexlen = 0; 3480 indexpos = -1; 3481 ncores = num_cores; 3482 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3483 sx_slock(&corefilename_lock); 3484 for (i = 0; format[i] != '\0'; i++) { 3485 switch (format[i]) { 3486 case '%': /* Format character */ 3487 i++; 3488 switch (format[i]) { 3489 case '%': 3490 sbuf_putc(&sb, '%'); 3491 break; 3492 case 'H': /* hostname */ 3493 if (hostname == NULL) { 3494 hostname = malloc(MAXHOSTNAMELEN, 3495 M_TEMP, M_WAITOK); 3496 } 3497 getcredhostname(td->td_ucred, hostname, 3498 MAXHOSTNAMELEN); 3499 sbuf_printf(&sb, "%s", hostname); 3500 break; 3501 case 'I': /* autoincrementing index */ 3502 if (indexpos != -1) { 3503 sbuf_printf(&sb, "%%I"); 3504 break; 3505 } 3506 3507 indexpos = sbuf_len(&sb); 3508 sbuf_printf(&sb, "%u", ncores - 1); 3509 indexlen = sbuf_len(&sb) - indexpos; 3510 break; 3511 case 'N': /* process name */ 3512 sbuf_printf(&sb, "%s", comm); 3513 break; 3514 case 'P': /* process id */ 3515 sbuf_printf(&sb, "%u", pid); 3516 break; 3517 case 'S': /* signal number */ 3518 sbuf_printf(&sb, "%i", signum); 3519 break; 3520 case 'U': /* user id */ 3521 sbuf_printf(&sb, "%u", uid); 3522 break; 3523 default: 3524 log(LOG_ERR, 3525 "Unknown format character %c in " 3526 "corename `%s'\n", format[i], format); 3527 break; 3528 } 3529 break; 3530 default: 3531 sbuf_putc(&sb, format[i]); 3532 break; 3533 } 3534 } 3535 sx_sunlock(&corefilename_lock); 3536 free(hostname, M_TEMP); 3537 if (compress == COMPRESS_GZIP) 3538 sbuf_printf(&sb, GZIP_SUFFIX); 3539 else if (compress == COMPRESS_ZSTD) 3540 sbuf_printf(&sb, ZSTD_SUFFIX); 3541 if (sbuf_error(&sb) != 0) { 3542 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3543 "long\n", (long)pid, comm, (u_long)uid); 3544 sbuf_delete(&sb); 3545 free(name, M_TEMP); 3546 return (ENOMEM); 3547 } 3548 sbuf_finish(&sb); 3549 sbuf_delete(&sb); 3550 3551 if (indexpos != -1) { 3552 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3553 vpp); 3554 if (error != 0) { 3555 log(LOG_ERR, 3556 "pid %d (%s), uid (%u): Path `%s' failed " 3557 "on initial open test, error = %d\n", 3558 pid, comm, uid, name, error); 3559 } 3560 } else { 3561 cmode = S_IRUSR | S_IWUSR; 3562 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3563 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3564 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3565 if ((td->td_proc->p_flag & P_SUGID) != 0) 3566 flags |= O_EXCL; 3567 3568 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3569 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3570 NULL); 3571 if (error == 0) { 3572 *vpp = nd.ni_vp; 3573 NDFREE(&nd, NDF_ONLY_PNBUF); 3574 } 3575 } 3576 3577 if (error != 0) { 3578 #ifdef AUDIT 3579 audit_proc_coredump(td, name, error); 3580 #endif 3581 free(name, M_TEMP); 3582 return (error); 3583 } 3584 *namep = name; 3585 return (0); 3586 } 3587 3588 /* 3589 * Dump a process' core. The main routine does some 3590 * policy checking, and creates the name of the coredump; 3591 * then it passes on a vnode and a size limit to the process-specific 3592 * coredump routine if there is one; if there _is not_ one, it returns 3593 * ENOSYS; otherwise it returns the error from the process-specific routine. 3594 */ 3595 3596 static int 3597 coredump(struct thread *td) 3598 { 3599 struct proc *p = td->td_proc; 3600 struct ucred *cred = td->td_ucred; 3601 struct vnode *vp; 3602 struct flock lf; 3603 struct vattr vattr; 3604 int error, error1, locked; 3605 char *name; /* name of corefile */ 3606 void *rl_cookie; 3607 off_t limit; 3608 char *fullpath, *freepath = NULL; 3609 struct sbuf *sb; 3610 3611 PROC_LOCK_ASSERT(p, MA_OWNED); 3612 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3613 _STOPEVENT(p, S_CORE, 0); 3614 3615 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3616 (p->p_flag2 & P2_NOTRACE) != 0) { 3617 PROC_UNLOCK(p); 3618 return (EFAULT); 3619 } 3620 3621 /* 3622 * Note that the bulk of limit checking is done after 3623 * the corefile is created. The exception is if the limit 3624 * for corefiles is 0, in which case we don't bother 3625 * creating the corefile at all. This layout means that 3626 * a corefile is truncated instead of not being created, 3627 * if it is larger than the limit. 3628 */ 3629 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3630 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3631 PROC_UNLOCK(p); 3632 return (EFBIG); 3633 } 3634 PROC_UNLOCK(p); 3635 3636 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3637 compress_user_cores, p->p_sig, &vp, &name); 3638 if (error != 0) 3639 return (error); 3640 3641 /* 3642 * Don't dump to non-regular files or files with links. 3643 * Do not dump into system files. Effective user must own the corefile. 3644 */ 3645 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3646 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 3647 vattr.va_uid != cred->cr_uid) { 3648 VOP_UNLOCK(vp, 0); 3649 error = EFAULT; 3650 goto out; 3651 } 3652 3653 VOP_UNLOCK(vp, 0); 3654 3655 /* Postpone other writers, including core dumps of other processes. */ 3656 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3657 3658 lf.l_whence = SEEK_SET; 3659 lf.l_start = 0; 3660 lf.l_len = 0; 3661 lf.l_type = F_WRLCK; 3662 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3663 3664 VATTR_NULL(&vattr); 3665 vattr.va_size = 0; 3666 if (set_core_nodump_flag) 3667 vattr.va_flags = UF_NODUMP; 3668 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3669 VOP_SETATTR(vp, &vattr, cred); 3670 VOP_UNLOCK(vp, 0); 3671 PROC_LOCK(p); 3672 p->p_acflag |= ACORE; 3673 PROC_UNLOCK(p); 3674 3675 if (p->p_sysent->sv_coredump != NULL) { 3676 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3677 } else { 3678 error = ENOSYS; 3679 } 3680 3681 if (locked) { 3682 lf.l_type = F_UNLCK; 3683 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3684 } 3685 vn_rangelock_unlock(vp, rl_cookie); 3686 3687 /* 3688 * Notify the userland helper that a process triggered a core dump. 3689 * This allows the helper to run an automated debugging session. 3690 */ 3691 if (error != 0 || coredump_devctl == 0) 3692 goto out; 3693 sb = sbuf_new_auto(); 3694 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3695 goto out2; 3696 sbuf_printf(sb, "comm=\""); 3697 devctl_safe_quote_sb(sb, fullpath); 3698 free(freepath, M_TEMP); 3699 sbuf_printf(sb, "\" core=\""); 3700 3701 /* 3702 * We can't lookup core file vp directly. When we're replacing a core, and 3703 * other random times, we flush the name cache, so it will fail. Instead, 3704 * if the path of the core is relative, add the current dir in front if it. 3705 */ 3706 if (name[0] != '/') { 3707 fullpath = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 3708 if (kern___getcwd(td, fullpath, UIO_SYSSPACE, MAXPATHLEN, MAXPATHLEN) != 0) { 3709 free(fullpath, M_TEMP); 3710 goto out2; 3711 } 3712 devctl_safe_quote_sb(sb, fullpath); 3713 free(fullpath, M_TEMP); 3714 sbuf_putc(sb, '/'); 3715 } 3716 devctl_safe_quote_sb(sb, name); 3717 sbuf_printf(sb, "\""); 3718 if (sbuf_finish(sb) == 0) 3719 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 3720 out2: 3721 sbuf_delete(sb); 3722 out: 3723 error1 = vn_close(vp, FWRITE, cred, td); 3724 if (error == 0) 3725 error = error1; 3726 #ifdef AUDIT 3727 audit_proc_coredump(td, name, error); 3728 #endif 3729 free(name, M_TEMP); 3730 return (error); 3731 } 3732 3733 /* 3734 * Nonexistent system call-- signal process (may want to handle it). Flag 3735 * error in case process won't see signal immediately (blocked or ignored). 3736 */ 3737 #ifndef _SYS_SYSPROTO_H_ 3738 struct nosys_args { 3739 int dummy; 3740 }; 3741 #endif 3742 /* ARGSUSED */ 3743 int 3744 nosys(struct thread *td, struct nosys_args *args) 3745 { 3746 struct proc *p; 3747 3748 p = td->td_proc; 3749 3750 PROC_LOCK(p); 3751 tdsignal(td, SIGSYS); 3752 PROC_UNLOCK(p); 3753 if (kern_lognosys == 1 || kern_lognosys == 3) { 3754 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3755 td->td_sa.code); 3756 } 3757 if (kern_lognosys == 2 || kern_lognosys == 3) { 3758 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3759 td->td_sa.code); 3760 } 3761 return (ENOSYS); 3762 } 3763 3764 /* 3765 * Send a SIGIO or SIGURG signal to a process or process group using stored 3766 * credentials rather than those of the current process. 3767 */ 3768 void 3769 pgsigio(struct sigio **sigiop, int sig, int checkctty) 3770 { 3771 ksiginfo_t ksi; 3772 struct sigio *sigio; 3773 3774 ksiginfo_init(&ksi); 3775 ksi.ksi_signo = sig; 3776 ksi.ksi_code = SI_KERNEL; 3777 3778 SIGIO_LOCK(); 3779 sigio = *sigiop; 3780 if (sigio == NULL) { 3781 SIGIO_UNLOCK(); 3782 return; 3783 } 3784 if (sigio->sio_pgid > 0) { 3785 PROC_LOCK(sigio->sio_proc); 3786 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3787 kern_psignal(sigio->sio_proc, sig); 3788 PROC_UNLOCK(sigio->sio_proc); 3789 } else if (sigio->sio_pgid < 0) { 3790 struct proc *p; 3791 3792 PGRP_LOCK(sigio->sio_pgrp); 3793 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3794 PROC_LOCK(p); 3795 if (p->p_state == PRS_NORMAL && 3796 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3797 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3798 kern_psignal(p, sig); 3799 PROC_UNLOCK(p); 3800 } 3801 PGRP_UNLOCK(sigio->sio_pgrp); 3802 } 3803 SIGIO_UNLOCK(); 3804 } 3805 3806 static int 3807 filt_sigattach(struct knote *kn) 3808 { 3809 struct proc *p = curproc; 3810 3811 kn->kn_ptr.p_proc = p; 3812 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3813 3814 knlist_add(p->p_klist, kn, 0); 3815 3816 return (0); 3817 } 3818 3819 static void 3820 filt_sigdetach(struct knote *kn) 3821 { 3822 struct proc *p = kn->kn_ptr.p_proc; 3823 3824 knlist_remove(p->p_klist, kn, 0); 3825 } 3826 3827 /* 3828 * signal knotes are shared with proc knotes, so we apply a mask to 3829 * the hint in order to differentiate them from process hints. This 3830 * could be avoided by using a signal-specific knote list, but probably 3831 * isn't worth the trouble. 3832 */ 3833 static int 3834 filt_signal(struct knote *kn, long hint) 3835 { 3836 3837 if (hint & NOTE_SIGNAL) { 3838 hint &= ~NOTE_SIGNAL; 3839 3840 if (kn->kn_id == hint) 3841 kn->kn_data++; 3842 } 3843 return (kn->kn_data != 0); 3844 } 3845 3846 struct sigacts * 3847 sigacts_alloc(void) 3848 { 3849 struct sigacts *ps; 3850 3851 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3852 refcount_init(&ps->ps_refcnt, 1); 3853 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3854 return (ps); 3855 } 3856 3857 void 3858 sigacts_free(struct sigacts *ps) 3859 { 3860 3861 if (refcount_release(&ps->ps_refcnt) == 0) 3862 return; 3863 mtx_destroy(&ps->ps_mtx); 3864 free(ps, M_SUBPROC); 3865 } 3866 3867 struct sigacts * 3868 sigacts_hold(struct sigacts *ps) 3869 { 3870 3871 refcount_acquire(&ps->ps_refcnt); 3872 return (ps); 3873 } 3874 3875 void 3876 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3877 { 3878 3879 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3880 mtx_lock(&src->ps_mtx); 3881 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3882 mtx_unlock(&src->ps_mtx); 3883 } 3884 3885 int 3886 sigacts_shared(struct sigacts *ps) 3887 { 3888 3889 return (ps->ps_refcnt > 1); 3890 } 3891 3892 void 3893 sig_drop_caught(struct proc *p) 3894 { 3895 int sig; 3896 struct sigacts *ps; 3897 3898 ps = p->p_sigacts; 3899 PROC_LOCK_ASSERT(p, MA_OWNED); 3900 mtx_assert(&ps->ps_mtx, MA_OWNED); 3901 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 3902 sig = sig_ffs(&ps->ps_sigcatch); 3903 sigdflt(ps, sig); 3904 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 3905 sigqueue_delete_proc(p, sig); 3906 } 3907 } 3908