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 1776 return (kern_kill(td, uap->pid, uap->signum)); 1777 } 1778 1779 int 1780 kern_kill(struct thread *td, pid_t pid, int signum) 1781 { 1782 ksiginfo_t ksi; 1783 struct proc *p; 1784 int error; 1785 1786 /* 1787 * A process in capability mode can send signals only to himself. 1788 * The main rationale behind this is that abort(3) is implemented as 1789 * kill(getpid(), SIGABRT). 1790 */ 1791 if (IN_CAPABILITY_MODE(td) && pid != td->td_proc->p_pid) 1792 return (ECAPMODE); 1793 1794 AUDIT_ARG_SIGNUM(signum); 1795 AUDIT_ARG_PID(pid); 1796 if ((u_int)signum > _SIG_MAXSIG) 1797 return (EINVAL); 1798 1799 ksiginfo_init(&ksi); 1800 ksi.ksi_signo = signum; 1801 ksi.ksi_code = SI_USER; 1802 ksi.ksi_pid = td->td_proc->p_pid; 1803 ksi.ksi_uid = td->td_ucred->cr_ruid; 1804 1805 if (pid > 0) { 1806 /* kill single process */ 1807 if ((p = pfind_any(pid)) == NULL) 1808 return (ESRCH); 1809 AUDIT_ARG_PROCESS(p); 1810 error = p_cansignal(td, p, signum); 1811 if (error == 0 && signum) 1812 pksignal(p, signum, &ksi); 1813 PROC_UNLOCK(p); 1814 return (error); 1815 } 1816 switch (pid) { 1817 case -1: /* broadcast signal */ 1818 return (killpg1(td, signum, 0, 1, &ksi)); 1819 case 0: /* signal own process group */ 1820 return (killpg1(td, signum, 0, 0, &ksi)); 1821 default: /* negative explicit process group */ 1822 return (killpg1(td, signum, -pid, 0, &ksi)); 1823 } 1824 /* NOTREACHED */ 1825 } 1826 1827 int 1828 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1829 { 1830 struct proc *p; 1831 int error; 1832 1833 AUDIT_ARG_SIGNUM(uap->signum); 1834 AUDIT_ARG_FD(uap->fd); 1835 if ((u_int)uap->signum > _SIG_MAXSIG) 1836 return (EINVAL); 1837 1838 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1839 if (error) 1840 return (error); 1841 AUDIT_ARG_PROCESS(p); 1842 error = p_cansignal(td, p, uap->signum); 1843 if (error == 0 && uap->signum) 1844 kern_psignal(p, uap->signum); 1845 PROC_UNLOCK(p); 1846 return (error); 1847 } 1848 1849 #if defined(COMPAT_43) 1850 #ifndef _SYS_SYSPROTO_H_ 1851 struct okillpg_args { 1852 int pgid; 1853 int signum; 1854 }; 1855 #endif 1856 /* ARGSUSED */ 1857 int 1858 okillpg(struct thread *td, struct okillpg_args *uap) 1859 { 1860 ksiginfo_t ksi; 1861 1862 AUDIT_ARG_SIGNUM(uap->signum); 1863 AUDIT_ARG_PID(uap->pgid); 1864 if ((u_int)uap->signum > _SIG_MAXSIG) 1865 return (EINVAL); 1866 1867 ksiginfo_init(&ksi); 1868 ksi.ksi_signo = uap->signum; 1869 ksi.ksi_code = SI_USER; 1870 ksi.ksi_pid = td->td_proc->p_pid; 1871 ksi.ksi_uid = td->td_ucred->cr_ruid; 1872 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1873 } 1874 #endif /* COMPAT_43 */ 1875 1876 #ifndef _SYS_SYSPROTO_H_ 1877 struct sigqueue_args { 1878 pid_t pid; 1879 int signum; 1880 /* union sigval */ void *value; 1881 }; 1882 #endif 1883 int 1884 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1885 { 1886 union sigval sv; 1887 1888 sv.sival_ptr = uap->value; 1889 1890 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1891 } 1892 1893 int 1894 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1895 { 1896 ksiginfo_t ksi; 1897 struct proc *p; 1898 int error; 1899 1900 if ((u_int)signum > _SIG_MAXSIG) 1901 return (EINVAL); 1902 1903 /* 1904 * Specification says sigqueue can only send signal to 1905 * single process. 1906 */ 1907 if (pid <= 0) 1908 return (EINVAL); 1909 1910 if ((p = pfind_any(pid)) == NULL) 1911 return (ESRCH); 1912 error = p_cansignal(td, p, signum); 1913 if (error == 0 && signum != 0) { 1914 ksiginfo_init(&ksi); 1915 ksi.ksi_flags = KSI_SIGQ; 1916 ksi.ksi_signo = signum; 1917 ksi.ksi_code = SI_QUEUE; 1918 ksi.ksi_pid = td->td_proc->p_pid; 1919 ksi.ksi_uid = td->td_ucred->cr_ruid; 1920 ksi.ksi_value = *value; 1921 error = pksignal(p, ksi.ksi_signo, &ksi); 1922 } 1923 PROC_UNLOCK(p); 1924 return (error); 1925 } 1926 1927 /* 1928 * Send a signal to a process group. 1929 */ 1930 void 1931 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1932 { 1933 struct pgrp *pgrp; 1934 1935 if (pgid != 0) { 1936 sx_slock(&proctree_lock); 1937 pgrp = pgfind(pgid); 1938 sx_sunlock(&proctree_lock); 1939 if (pgrp != NULL) { 1940 pgsignal(pgrp, sig, 0, ksi); 1941 PGRP_UNLOCK(pgrp); 1942 } 1943 } 1944 } 1945 1946 /* 1947 * Send a signal to a process group. If checktty is 1, 1948 * limit to members which have a controlling terminal. 1949 */ 1950 void 1951 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1952 { 1953 struct proc *p; 1954 1955 if (pgrp) { 1956 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1957 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1958 PROC_LOCK(p); 1959 if (p->p_state == PRS_NORMAL && 1960 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1961 pksignal(p, sig, ksi); 1962 PROC_UNLOCK(p); 1963 } 1964 } 1965 } 1966 1967 1968 /* 1969 * Recalculate the signal mask and reset the signal disposition after 1970 * usermode frame for delivery is formed. Should be called after 1971 * mach-specific routine, because sysent->sv_sendsig() needs correct 1972 * ps_siginfo and signal mask. 1973 */ 1974 static void 1975 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1976 { 1977 sigset_t mask; 1978 1979 mtx_assert(&ps->ps_mtx, MA_OWNED); 1980 td->td_ru.ru_nsignals++; 1981 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1982 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1983 SIGADDSET(mask, sig); 1984 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1985 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1986 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1987 sigdflt(ps, sig); 1988 } 1989 1990 1991 /* 1992 * Send a signal caused by a trap to the current thread. If it will be 1993 * caught immediately, deliver it with correct code. Otherwise, post it 1994 * normally. 1995 */ 1996 void 1997 trapsignal(struct thread *td, ksiginfo_t *ksi) 1998 { 1999 struct sigacts *ps; 2000 struct proc *p; 2001 int sig; 2002 int code; 2003 2004 p = td->td_proc; 2005 sig = ksi->ksi_signo; 2006 code = ksi->ksi_code; 2007 KASSERT(_SIG_VALID(sig), ("invalid signal")); 2008 2009 PROC_LOCK(p); 2010 ps = p->p_sigacts; 2011 mtx_lock(&ps->ps_mtx); 2012 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 2013 !SIGISMEMBER(td->td_sigmask, sig)) { 2014 #ifdef KTRACE 2015 if (KTRPOINT(curthread, KTR_PSIG)) 2016 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 2017 &td->td_sigmask, code); 2018 #endif 2019 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 2020 ksi, &td->td_sigmask); 2021 postsig_done(sig, td, ps); 2022 mtx_unlock(&ps->ps_mtx); 2023 } else { 2024 /* 2025 * Avoid a possible infinite loop if the thread 2026 * masking the signal or process is ignoring the 2027 * signal. 2028 */ 2029 if (kern_forcesigexit && 2030 (SIGISMEMBER(td->td_sigmask, sig) || 2031 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2032 SIGDELSET(td->td_sigmask, sig); 2033 SIGDELSET(ps->ps_sigcatch, sig); 2034 SIGDELSET(ps->ps_sigignore, sig); 2035 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2036 } 2037 mtx_unlock(&ps->ps_mtx); 2038 p->p_sig = sig; /* XXX to verify code */ 2039 tdsendsignal(p, td, sig, ksi); 2040 } 2041 PROC_UNLOCK(p); 2042 } 2043 2044 static struct thread * 2045 sigtd(struct proc *p, int sig, int prop) 2046 { 2047 struct thread *td, *signal_td; 2048 2049 PROC_LOCK_ASSERT(p, MA_OWNED); 2050 2051 /* 2052 * Check if current thread can handle the signal without 2053 * switching context to another thread. 2054 */ 2055 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2056 return (curthread); 2057 signal_td = NULL; 2058 FOREACH_THREAD_IN_PROC(p, td) { 2059 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2060 signal_td = td; 2061 break; 2062 } 2063 } 2064 if (signal_td == NULL) 2065 signal_td = FIRST_THREAD_IN_PROC(p); 2066 return (signal_td); 2067 } 2068 2069 /* 2070 * Send the signal to the process. If the signal has an action, the action 2071 * is usually performed by the target process rather than the caller; we add 2072 * the signal to the set of pending signals for the process. 2073 * 2074 * Exceptions: 2075 * o When a stop signal is sent to a sleeping process that takes the 2076 * default action, the process is stopped without awakening it. 2077 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2078 * regardless of the signal action (eg, blocked or ignored). 2079 * 2080 * Other ignored signals are discarded immediately. 2081 * 2082 * NB: This function may be entered from the debugger via the "kill" DDB 2083 * command. There is little that can be done to mitigate the possibly messy 2084 * side effects of this unwise possibility. 2085 */ 2086 void 2087 kern_psignal(struct proc *p, int sig) 2088 { 2089 ksiginfo_t ksi; 2090 2091 ksiginfo_init(&ksi); 2092 ksi.ksi_signo = sig; 2093 ksi.ksi_code = SI_KERNEL; 2094 (void) tdsendsignal(p, NULL, sig, &ksi); 2095 } 2096 2097 int 2098 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2099 { 2100 2101 return (tdsendsignal(p, NULL, sig, ksi)); 2102 } 2103 2104 /* Utility function for finding a thread to send signal event to. */ 2105 int 2106 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2107 { 2108 struct thread *td; 2109 2110 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2111 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2112 if (td == NULL) 2113 return (ESRCH); 2114 *ttd = td; 2115 } else { 2116 *ttd = NULL; 2117 PROC_LOCK(p); 2118 } 2119 return (0); 2120 } 2121 2122 void 2123 tdsignal(struct thread *td, int sig) 2124 { 2125 ksiginfo_t ksi; 2126 2127 ksiginfo_init(&ksi); 2128 ksi.ksi_signo = sig; 2129 ksi.ksi_code = SI_KERNEL; 2130 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2131 } 2132 2133 void 2134 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2135 { 2136 2137 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2138 } 2139 2140 int 2141 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2142 { 2143 sig_t action; 2144 sigqueue_t *sigqueue; 2145 int prop; 2146 struct sigacts *ps; 2147 int intrval; 2148 int ret = 0; 2149 int wakeup_swapper; 2150 2151 MPASS(td == NULL || p == td->td_proc); 2152 PROC_LOCK_ASSERT(p, MA_OWNED); 2153 2154 if (!_SIG_VALID(sig)) 2155 panic("%s(): invalid signal %d", __func__, sig); 2156 2157 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2158 2159 /* 2160 * IEEE Std 1003.1-2001: return success when killing a zombie. 2161 */ 2162 if (p->p_state == PRS_ZOMBIE) { 2163 if (ksi && (ksi->ksi_flags & KSI_INS)) 2164 ksiginfo_tryfree(ksi); 2165 return (ret); 2166 } 2167 2168 ps = p->p_sigacts; 2169 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2170 prop = sigprop(sig); 2171 2172 if (td == NULL) { 2173 td = sigtd(p, sig, prop); 2174 sigqueue = &p->p_sigqueue; 2175 } else 2176 sigqueue = &td->td_sigqueue; 2177 2178 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2179 2180 /* 2181 * If the signal is being ignored, 2182 * then we forget about it immediately. 2183 * (Note: we don't set SIGCONT in ps_sigignore, 2184 * and if it is set to SIG_IGN, 2185 * action will be SIG_DFL here.) 2186 */ 2187 mtx_lock(&ps->ps_mtx); 2188 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2189 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2190 2191 mtx_unlock(&ps->ps_mtx); 2192 if (ksi && (ksi->ksi_flags & KSI_INS)) 2193 ksiginfo_tryfree(ksi); 2194 return (ret); 2195 } 2196 if (SIGISMEMBER(td->td_sigmask, sig)) 2197 action = SIG_HOLD; 2198 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2199 action = SIG_CATCH; 2200 else 2201 action = SIG_DFL; 2202 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2203 intrval = EINTR; 2204 else 2205 intrval = ERESTART; 2206 mtx_unlock(&ps->ps_mtx); 2207 2208 if (prop & SIGPROP_CONT) 2209 sigqueue_delete_stopmask_proc(p); 2210 else if (prop & SIGPROP_STOP) { 2211 /* 2212 * If sending a tty stop signal to a member of an orphaned 2213 * process group, discard the signal here if the action 2214 * is default; don't stop the process below if sleeping, 2215 * and don't clear any pending SIGCONT. 2216 */ 2217 if ((prop & SIGPROP_TTYSTOP) && 2218 (p->p_pgrp->pg_jobc == 0) && 2219 (action == SIG_DFL)) { 2220 if (ksi && (ksi->ksi_flags & KSI_INS)) 2221 ksiginfo_tryfree(ksi); 2222 return (ret); 2223 } 2224 sigqueue_delete_proc(p, SIGCONT); 2225 if (p->p_flag & P_CONTINUED) { 2226 p->p_flag &= ~P_CONTINUED; 2227 PROC_LOCK(p->p_pptr); 2228 sigqueue_take(p->p_ksi); 2229 PROC_UNLOCK(p->p_pptr); 2230 } 2231 } 2232 2233 ret = sigqueue_add(sigqueue, sig, ksi); 2234 if (ret != 0) 2235 return (ret); 2236 signotify(td); 2237 /* 2238 * Defer further processing for signals which are held, 2239 * except that stopped processes must be continued by SIGCONT. 2240 */ 2241 if (action == SIG_HOLD && 2242 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2243 return (ret); 2244 2245 /* SIGKILL: Remove procfs STOPEVENTs. */ 2246 if (sig == SIGKILL) { 2247 /* from procfs_ioctl.c: PIOCBIC */ 2248 p->p_stops = 0; 2249 /* from procfs_ioctl.c: PIOCCONT */ 2250 p->p_step = 0; 2251 wakeup(&p->p_step); 2252 } 2253 /* 2254 * Some signals have a process-wide effect and a per-thread 2255 * component. Most processing occurs when the process next 2256 * tries to cross the user boundary, however there are some 2257 * times when processing needs to be done immediately, such as 2258 * waking up threads so that they can cross the user boundary. 2259 * We try to do the per-process part here. 2260 */ 2261 if (P_SHOULDSTOP(p)) { 2262 KASSERT(!(p->p_flag & P_WEXIT), 2263 ("signal to stopped but exiting process")); 2264 if (sig == SIGKILL) { 2265 /* 2266 * If traced process is already stopped, 2267 * then no further action is necessary. 2268 */ 2269 if (p->p_flag & P_TRACED) 2270 goto out; 2271 /* 2272 * SIGKILL sets process running. 2273 * It will die elsewhere. 2274 * All threads must be restarted. 2275 */ 2276 p->p_flag &= ~P_STOPPED_SIG; 2277 goto runfast; 2278 } 2279 2280 if (prop & SIGPROP_CONT) { 2281 /* 2282 * If traced process is already stopped, 2283 * then no further action is necessary. 2284 */ 2285 if (p->p_flag & P_TRACED) 2286 goto out; 2287 /* 2288 * If SIGCONT is default (or ignored), we continue the 2289 * process but don't leave the signal in sigqueue as 2290 * it has no further action. If SIGCONT is held, we 2291 * continue the process and leave the signal in 2292 * sigqueue. If the process catches SIGCONT, let it 2293 * handle the signal itself. If it isn't waiting on 2294 * an event, it goes back to run state. 2295 * Otherwise, process goes back to sleep state. 2296 */ 2297 p->p_flag &= ~P_STOPPED_SIG; 2298 PROC_SLOCK(p); 2299 if (p->p_numthreads == p->p_suspcount) { 2300 PROC_SUNLOCK(p); 2301 p->p_flag |= P_CONTINUED; 2302 p->p_xsig = SIGCONT; 2303 PROC_LOCK(p->p_pptr); 2304 childproc_continued(p); 2305 PROC_UNLOCK(p->p_pptr); 2306 PROC_SLOCK(p); 2307 } 2308 if (action == SIG_DFL) { 2309 thread_unsuspend(p); 2310 PROC_SUNLOCK(p); 2311 sigqueue_delete(sigqueue, sig); 2312 goto out; 2313 } 2314 if (action == SIG_CATCH) { 2315 /* 2316 * The process wants to catch it so it needs 2317 * to run at least one thread, but which one? 2318 */ 2319 PROC_SUNLOCK(p); 2320 goto runfast; 2321 } 2322 /* 2323 * The signal is not ignored or caught. 2324 */ 2325 thread_unsuspend(p); 2326 PROC_SUNLOCK(p); 2327 goto out; 2328 } 2329 2330 if (prop & SIGPROP_STOP) { 2331 /* 2332 * If traced process is already stopped, 2333 * then no further action is necessary. 2334 */ 2335 if (p->p_flag & P_TRACED) 2336 goto out; 2337 /* 2338 * Already stopped, don't need to stop again 2339 * (If we did the shell could get confused). 2340 * Just make sure the signal STOP bit set. 2341 */ 2342 p->p_flag |= P_STOPPED_SIG; 2343 sigqueue_delete(sigqueue, sig); 2344 goto out; 2345 } 2346 2347 /* 2348 * All other kinds of signals: 2349 * If a thread is sleeping interruptibly, simulate a 2350 * wakeup so that when it is continued it will be made 2351 * runnable and can look at the signal. However, don't make 2352 * the PROCESS runnable, leave it stopped. 2353 * It may run a bit until it hits a thread_suspend_check(). 2354 */ 2355 wakeup_swapper = 0; 2356 PROC_SLOCK(p); 2357 thread_lock(td); 2358 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2359 wakeup_swapper = sleepq_abort(td, intrval); 2360 thread_unlock(td); 2361 PROC_SUNLOCK(p); 2362 if (wakeup_swapper) 2363 kick_proc0(); 2364 goto out; 2365 /* 2366 * Mutexes are short lived. Threads waiting on them will 2367 * hit thread_suspend_check() soon. 2368 */ 2369 } else if (p->p_state == PRS_NORMAL) { 2370 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2371 tdsigwakeup(td, sig, action, intrval); 2372 goto out; 2373 } 2374 2375 MPASS(action == SIG_DFL); 2376 2377 if (prop & SIGPROP_STOP) { 2378 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2379 goto out; 2380 p->p_flag |= P_STOPPED_SIG; 2381 p->p_xsig = sig; 2382 PROC_SLOCK(p); 2383 wakeup_swapper = sig_suspend_threads(td, p, 1); 2384 if (p->p_numthreads == p->p_suspcount) { 2385 /* 2386 * only thread sending signal to another 2387 * process can reach here, if thread is sending 2388 * signal to its process, because thread does 2389 * not suspend itself here, p_numthreads 2390 * should never be equal to p_suspcount. 2391 */ 2392 thread_stopped(p); 2393 PROC_SUNLOCK(p); 2394 sigqueue_delete_proc(p, p->p_xsig); 2395 } else 2396 PROC_SUNLOCK(p); 2397 if (wakeup_swapper) 2398 kick_proc0(); 2399 goto out; 2400 } 2401 } else { 2402 /* Not in "NORMAL" state. discard the signal. */ 2403 sigqueue_delete(sigqueue, sig); 2404 goto out; 2405 } 2406 2407 /* 2408 * The process is not stopped so we need to apply the signal to all the 2409 * running threads. 2410 */ 2411 runfast: 2412 tdsigwakeup(td, sig, action, intrval); 2413 PROC_SLOCK(p); 2414 thread_unsuspend(p); 2415 PROC_SUNLOCK(p); 2416 out: 2417 /* If we jump here, proc slock should not be owned. */ 2418 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2419 return (ret); 2420 } 2421 2422 /* 2423 * The force of a signal has been directed against a single 2424 * thread. We need to see what we can do about knocking it 2425 * out of any sleep it may be in etc. 2426 */ 2427 static void 2428 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2429 { 2430 struct proc *p = td->td_proc; 2431 int prop; 2432 int wakeup_swapper; 2433 2434 wakeup_swapper = 0; 2435 PROC_LOCK_ASSERT(p, MA_OWNED); 2436 prop = sigprop(sig); 2437 2438 PROC_SLOCK(p); 2439 thread_lock(td); 2440 /* 2441 * Bring the priority of a thread up if we want it to get 2442 * killed in this lifetime. Be careful to avoid bumping the 2443 * priority of the idle thread, since we still allow to signal 2444 * kernel processes. 2445 */ 2446 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2447 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2448 sched_prio(td, PUSER); 2449 if (TD_ON_SLEEPQ(td)) { 2450 /* 2451 * If thread is sleeping uninterruptibly 2452 * we can't interrupt the sleep... the signal will 2453 * be noticed when the process returns through 2454 * trap() or syscall(). 2455 */ 2456 if ((td->td_flags & TDF_SINTR) == 0) 2457 goto out; 2458 /* 2459 * If SIGCONT is default (or ignored) and process is 2460 * asleep, we are finished; the process should not 2461 * be awakened. 2462 */ 2463 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2464 thread_unlock(td); 2465 PROC_SUNLOCK(p); 2466 sigqueue_delete(&p->p_sigqueue, sig); 2467 /* 2468 * It may be on either list in this state. 2469 * Remove from both for now. 2470 */ 2471 sigqueue_delete(&td->td_sigqueue, sig); 2472 return; 2473 } 2474 2475 /* 2476 * Don't awaken a sleeping thread for SIGSTOP if the 2477 * STOP signal is deferred. 2478 */ 2479 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2480 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2481 goto out; 2482 2483 /* 2484 * Give low priority threads a better chance to run. 2485 */ 2486 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2487 sched_prio(td, PUSER); 2488 2489 wakeup_swapper = sleepq_abort(td, intrval); 2490 } else { 2491 /* 2492 * Other states do nothing with the signal immediately, 2493 * other than kicking ourselves if we are running. 2494 * It will either never be noticed, or noticed very soon. 2495 */ 2496 #ifdef SMP 2497 if (TD_IS_RUNNING(td) && td != curthread) 2498 forward_signal(td); 2499 #endif 2500 } 2501 out: 2502 PROC_SUNLOCK(p); 2503 thread_unlock(td); 2504 if (wakeup_swapper) 2505 kick_proc0(); 2506 } 2507 2508 static int 2509 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2510 { 2511 struct thread *td2; 2512 int wakeup_swapper; 2513 2514 PROC_LOCK_ASSERT(p, MA_OWNED); 2515 PROC_SLOCK_ASSERT(p, MA_OWNED); 2516 MPASS(sending || td == curthread); 2517 2518 wakeup_swapper = 0; 2519 FOREACH_THREAD_IN_PROC(p, td2) { 2520 thread_lock(td2); 2521 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2522 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2523 (td2->td_flags & TDF_SINTR)) { 2524 if (td2->td_flags & TDF_SBDRY) { 2525 /* 2526 * Once a thread is asleep with 2527 * TDF_SBDRY and without TDF_SERESTART 2528 * or TDF_SEINTR set, it should never 2529 * become suspended due to this check. 2530 */ 2531 KASSERT(!TD_IS_SUSPENDED(td2), 2532 ("thread with deferred stops suspended")); 2533 if (TD_SBDRY_INTR(td2)) 2534 wakeup_swapper |= sleepq_abort(td2, 2535 TD_SBDRY_ERRNO(td2)); 2536 } else if (!TD_IS_SUSPENDED(td2)) { 2537 thread_suspend_one(td2); 2538 } 2539 } else if (!TD_IS_SUSPENDED(td2)) { 2540 if (sending || td != td2) 2541 td2->td_flags |= TDF_ASTPENDING; 2542 #ifdef SMP 2543 if (TD_IS_RUNNING(td2) && td2 != td) 2544 forward_signal(td2); 2545 #endif 2546 } 2547 thread_unlock(td2); 2548 } 2549 return (wakeup_swapper); 2550 } 2551 2552 /* 2553 * Stop the process for an event deemed interesting to the debugger. If si is 2554 * non-NULL, this is a signal exchange; the new signal requested by the 2555 * debugger will be returned for handling. If si is NULL, this is some other 2556 * type of interesting event. The debugger may request a signal be delivered in 2557 * that case as well, however it will be deferred until it can be handled. 2558 */ 2559 int 2560 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2561 { 2562 struct proc *p = td->td_proc; 2563 struct thread *td2; 2564 ksiginfo_t ksi; 2565 int prop; 2566 2567 PROC_LOCK_ASSERT(p, MA_OWNED); 2568 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2569 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2570 &p->p_mtx.lock_object, "Stopping for traced signal"); 2571 2572 td->td_xsig = sig; 2573 2574 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2575 td->td_dbgflags |= TDB_XSIG; 2576 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2577 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2578 PROC_SLOCK(p); 2579 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2580 if (P_KILLED(p)) { 2581 /* 2582 * Ensure that, if we've been PT_KILLed, the 2583 * exit status reflects that. Another thread 2584 * may also be in ptracestop(), having just 2585 * received the SIGKILL, but this thread was 2586 * unsuspended first. 2587 */ 2588 td->td_dbgflags &= ~TDB_XSIG; 2589 td->td_xsig = SIGKILL; 2590 p->p_ptevents = 0; 2591 break; 2592 } 2593 if (p->p_flag & P_SINGLE_EXIT && 2594 !(td->td_dbgflags & TDB_EXIT)) { 2595 /* 2596 * Ignore ptrace stops except for thread exit 2597 * events when the process exits. 2598 */ 2599 td->td_dbgflags &= ~TDB_XSIG; 2600 PROC_SUNLOCK(p); 2601 return (0); 2602 } 2603 2604 /* 2605 * Make wait(2) work. Ensure that right after the 2606 * attach, the thread which was decided to become the 2607 * leader of attach gets reported to the waiter. 2608 * Otherwise, just avoid overwriting another thread's 2609 * assignment to p_xthread. If another thread has 2610 * already set p_xthread, the current thread will get 2611 * a chance to report itself upon the next iteration. 2612 */ 2613 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2614 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2615 p->p_xthread == NULL)) { 2616 p->p_xsig = sig; 2617 p->p_xthread = td; 2618 2619 /* 2620 * If we are on sleepqueue already, 2621 * let sleepqueue code decide if it 2622 * needs to go sleep after attach. 2623 */ 2624 if (td->td_wchan == NULL) 2625 td->td_dbgflags &= ~TDB_FSTP; 2626 2627 p->p_flag2 &= ~P2_PTRACE_FSTP; 2628 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2629 sig_suspend_threads(td, p, 0); 2630 } 2631 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2632 td->td_dbgflags &= ~TDB_STOPATFORK; 2633 } 2634 stopme: 2635 thread_suspend_switch(td, p); 2636 if (p->p_xthread == td) 2637 p->p_xthread = NULL; 2638 if (!(p->p_flag & P_TRACED)) 2639 break; 2640 if (td->td_dbgflags & TDB_SUSPEND) { 2641 if (p->p_flag & P_SINGLE_EXIT) 2642 break; 2643 goto stopme; 2644 } 2645 } 2646 PROC_SUNLOCK(p); 2647 } 2648 2649 if (si != NULL && sig == td->td_xsig) { 2650 /* Parent wants us to take the original signal unchanged. */ 2651 si->ksi_flags |= KSI_HEAD; 2652 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2653 si->ksi_signo = 0; 2654 } else if (td->td_xsig != 0) { 2655 /* 2656 * If parent wants us to take a new signal, then it will leave 2657 * it in td->td_xsig; otherwise we just look for signals again. 2658 */ 2659 ksiginfo_init(&ksi); 2660 ksi.ksi_signo = td->td_xsig; 2661 ksi.ksi_flags |= KSI_PTRACE; 2662 prop = sigprop(td->td_xsig); 2663 td2 = sigtd(p, td->td_xsig, prop); 2664 tdsendsignal(p, td2, td->td_xsig, &ksi); 2665 if (td != td2) 2666 return (0); 2667 } 2668 2669 return (td->td_xsig); 2670 } 2671 2672 static void 2673 reschedule_signals(struct proc *p, sigset_t block, int flags) 2674 { 2675 struct sigacts *ps; 2676 struct thread *td; 2677 int sig; 2678 2679 PROC_LOCK_ASSERT(p, MA_OWNED); 2680 ps = p->p_sigacts; 2681 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2682 MA_OWNED : MA_NOTOWNED); 2683 if (SIGISEMPTY(p->p_siglist)) 2684 return; 2685 SIGSETAND(block, p->p_siglist); 2686 while ((sig = sig_ffs(&block)) != 0) { 2687 SIGDELSET(block, sig); 2688 td = sigtd(p, sig, 0); 2689 signotify(td); 2690 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2691 mtx_lock(&ps->ps_mtx); 2692 if (p->p_flag & P_TRACED || 2693 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2694 !SIGISMEMBER(td->td_sigmask, sig))) 2695 tdsigwakeup(td, sig, SIG_CATCH, 2696 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2697 ERESTART)); 2698 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2699 mtx_unlock(&ps->ps_mtx); 2700 } 2701 } 2702 2703 void 2704 tdsigcleanup(struct thread *td) 2705 { 2706 struct proc *p; 2707 sigset_t unblocked; 2708 2709 p = td->td_proc; 2710 PROC_LOCK_ASSERT(p, MA_OWNED); 2711 2712 sigqueue_flush(&td->td_sigqueue); 2713 if (p->p_numthreads == 1) 2714 return; 2715 2716 /* 2717 * Since we cannot handle signals, notify signal post code 2718 * about this by filling the sigmask. 2719 * 2720 * Also, if needed, wake up thread(s) that do not block the 2721 * same signals as the exiting thread, since the thread might 2722 * have been selected for delivery and woken up. 2723 */ 2724 SIGFILLSET(unblocked); 2725 SIGSETNAND(unblocked, td->td_sigmask); 2726 SIGFILLSET(td->td_sigmask); 2727 reschedule_signals(p, unblocked, 0); 2728 2729 } 2730 2731 static int 2732 sigdeferstop_curr_flags(int cflags) 2733 { 2734 2735 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2736 (cflags & TDF_SBDRY) != 0); 2737 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2738 } 2739 2740 /* 2741 * Defer the delivery of SIGSTOP for the current thread, according to 2742 * the requested mode. Returns previous flags, which must be restored 2743 * by sigallowstop(). 2744 * 2745 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2746 * cleared by the current thread, which allow the lock-less read-only 2747 * accesses below. 2748 */ 2749 int 2750 sigdeferstop_impl(int mode) 2751 { 2752 struct thread *td; 2753 int cflags, nflags; 2754 2755 td = curthread; 2756 cflags = sigdeferstop_curr_flags(td->td_flags); 2757 switch (mode) { 2758 case SIGDEFERSTOP_NOP: 2759 nflags = cflags; 2760 break; 2761 case SIGDEFERSTOP_OFF: 2762 nflags = 0; 2763 break; 2764 case SIGDEFERSTOP_SILENT: 2765 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2766 break; 2767 case SIGDEFERSTOP_EINTR: 2768 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2769 break; 2770 case SIGDEFERSTOP_ERESTART: 2771 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2772 break; 2773 default: 2774 panic("sigdeferstop: invalid mode %x", mode); 2775 break; 2776 } 2777 if (cflags == nflags) 2778 return (SIGDEFERSTOP_VAL_NCHG); 2779 thread_lock(td); 2780 td->td_flags = (td->td_flags & ~cflags) | nflags; 2781 thread_unlock(td); 2782 return (cflags); 2783 } 2784 2785 /* 2786 * Restores the STOP handling mode, typically permitting the delivery 2787 * of SIGSTOP for the current thread. This does not immediately 2788 * suspend if a stop was posted. Instead, the thread will suspend 2789 * either via ast() or a subsequent interruptible sleep. 2790 */ 2791 void 2792 sigallowstop_impl(int prev) 2793 { 2794 struct thread *td; 2795 int cflags; 2796 2797 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2798 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2799 ("sigallowstop: incorrect previous mode %x", prev)); 2800 td = curthread; 2801 cflags = sigdeferstop_curr_flags(td->td_flags); 2802 if (cflags != prev) { 2803 thread_lock(td); 2804 td->td_flags = (td->td_flags & ~cflags) | prev; 2805 thread_unlock(td); 2806 } 2807 } 2808 2809 /* 2810 * If the current process has received a signal (should be caught or cause 2811 * termination, should interrupt current syscall), return the signal number. 2812 * Stop signals with default action are processed immediately, then cleared; 2813 * they aren't returned. This is checked after each entry to the system for 2814 * a syscall or trap (though this can usually be done without calling issignal 2815 * by checking the pending signal masks in cursig.) The normal call 2816 * sequence is 2817 * 2818 * while (sig = cursig(curthread)) 2819 * postsig(sig); 2820 */ 2821 static int 2822 issignal(struct thread *td) 2823 { 2824 struct proc *p; 2825 struct sigacts *ps; 2826 struct sigqueue *queue; 2827 sigset_t sigpending; 2828 ksiginfo_t ksi; 2829 int prop, sig, traced; 2830 2831 p = td->td_proc; 2832 ps = p->p_sigacts; 2833 mtx_assert(&ps->ps_mtx, MA_OWNED); 2834 PROC_LOCK_ASSERT(p, MA_OWNED); 2835 for (;;) { 2836 traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2837 2838 sigpending = td->td_sigqueue.sq_signals; 2839 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2840 SIGSETNAND(sigpending, td->td_sigmask); 2841 2842 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2843 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2844 SIG_STOPSIGMASK(sigpending); 2845 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2846 return (0); 2847 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2848 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2849 SIGISMEMBER(sigpending, SIGSTOP)) { 2850 /* 2851 * If debugger just attached, always consume 2852 * SIGSTOP from ptrace(PT_ATTACH) first, to 2853 * execute the debugger attach ritual in 2854 * order. 2855 */ 2856 sig = SIGSTOP; 2857 td->td_dbgflags |= TDB_FSTP; 2858 } else { 2859 sig = sig_ffs(&sigpending); 2860 } 2861 2862 if (p->p_stops & S_SIG) { 2863 mtx_unlock(&ps->ps_mtx); 2864 stopevent(p, S_SIG, sig); 2865 mtx_lock(&ps->ps_mtx); 2866 } 2867 2868 /* 2869 * We should see pending but ignored signals 2870 * only if P_TRACED was on when they were posted. 2871 */ 2872 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2873 sigqueue_delete(&td->td_sigqueue, sig); 2874 sigqueue_delete(&p->p_sigqueue, sig); 2875 continue; 2876 } 2877 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2878 /* 2879 * If traced, always stop. 2880 * Remove old signal from queue before the stop. 2881 * XXX shrug off debugger, it causes siginfo to 2882 * be thrown away. 2883 */ 2884 queue = &td->td_sigqueue; 2885 ksiginfo_init(&ksi); 2886 if (sigqueue_get(queue, sig, &ksi) == 0) { 2887 queue = &p->p_sigqueue; 2888 sigqueue_get(queue, sig, &ksi); 2889 } 2890 td->td_si = ksi.ksi_info; 2891 2892 mtx_unlock(&ps->ps_mtx); 2893 sig = ptracestop(td, sig, &ksi); 2894 mtx_lock(&ps->ps_mtx); 2895 2896 td->td_si.si_signo = 0; 2897 2898 /* 2899 * Keep looking if the debugger discarded or 2900 * replaced the signal. 2901 */ 2902 if (sig == 0) 2903 continue; 2904 2905 /* 2906 * If the signal became masked, re-queue it. 2907 */ 2908 if (SIGISMEMBER(td->td_sigmask, sig)) { 2909 ksi.ksi_flags |= KSI_HEAD; 2910 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2911 continue; 2912 } 2913 2914 /* 2915 * If the traced bit got turned off, requeue 2916 * the signal and go back up to the top to 2917 * rescan signals. This ensures that p_sig* 2918 * and p_sigact are consistent. 2919 */ 2920 if ((p->p_flag & P_TRACED) == 0) { 2921 ksi.ksi_flags |= KSI_HEAD; 2922 sigqueue_add(queue, sig, &ksi); 2923 continue; 2924 } 2925 } 2926 2927 prop = sigprop(sig); 2928 2929 /* 2930 * Decide whether the signal should be returned. 2931 * Return the signal's number, or fall through 2932 * to clear it from the pending mask. 2933 */ 2934 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2935 2936 case (intptr_t)SIG_DFL: 2937 /* 2938 * Don't take default actions on system processes. 2939 */ 2940 if (p->p_pid <= 1) { 2941 #ifdef DIAGNOSTIC 2942 /* 2943 * Are you sure you want to ignore SIGSEGV 2944 * in init? XXX 2945 */ 2946 printf("Process (pid %lu) got signal %d\n", 2947 (u_long)p->p_pid, sig); 2948 #endif 2949 break; /* == ignore */ 2950 } 2951 /* 2952 * If there is a pending stop signal to process with 2953 * default action, stop here, then clear the signal. 2954 * Traced or exiting processes should ignore stops. 2955 * Additionally, a member of an orphaned process group 2956 * should ignore tty stops. 2957 */ 2958 if (prop & SIGPROP_STOP) { 2959 if (p->p_flag & 2960 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 2961 (p->p_pgrp->pg_jobc == 0 && 2962 prop & SIGPROP_TTYSTOP)) 2963 break; /* == ignore */ 2964 if (TD_SBDRY_INTR(td)) { 2965 KASSERT((td->td_flags & TDF_SBDRY) != 0, 2966 ("lost TDF_SBDRY")); 2967 return (-1); 2968 } 2969 mtx_unlock(&ps->ps_mtx); 2970 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2971 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2972 sigqueue_delete(&td->td_sigqueue, sig); 2973 sigqueue_delete(&p->p_sigqueue, sig); 2974 p->p_flag |= P_STOPPED_SIG; 2975 p->p_xsig = sig; 2976 PROC_SLOCK(p); 2977 sig_suspend_threads(td, p, 0); 2978 thread_suspend_switch(td, p); 2979 PROC_SUNLOCK(p); 2980 mtx_lock(&ps->ps_mtx); 2981 goto next; 2982 } else if (prop & SIGPROP_IGNORE) { 2983 /* 2984 * Except for SIGCONT, shouldn't get here. 2985 * Default action is to ignore; drop it. 2986 */ 2987 break; /* == ignore */ 2988 } else 2989 return (sig); 2990 /*NOTREACHED*/ 2991 2992 case (intptr_t)SIG_IGN: 2993 /* 2994 * Masking above should prevent us ever trying 2995 * to take action on an ignored signal other 2996 * than SIGCONT, unless process is traced. 2997 */ 2998 if ((prop & SIGPROP_CONT) == 0 && 2999 (p->p_flag & P_TRACED) == 0) 3000 printf("issignal\n"); 3001 break; /* == ignore */ 3002 3003 default: 3004 /* 3005 * This signal has an action, let 3006 * postsig() process it. 3007 */ 3008 return (sig); 3009 } 3010 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 3011 sigqueue_delete(&p->p_sigqueue, sig); 3012 next:; 3013 } 3014 /* NOTREACHED */ 3015 } 3016 3017 void 3018 thread_stopped(struct proc *p) 3019 { 3020 int n; 3021 3022 PROC_LOCK_ASSERT(p, MA_OWNED); 3023 PROC_SLOCK_ASSERT(p, MA_OWNED); 3024 n = p->p_suspcount; 3025 if (p == curproc) 3026 n++; 3027 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 3028 PROC_SUNLOCK(p); 3029 p->p_flag &= ~P_WAITED; 3030 PROC_LOCK(p->p_pptr); 3031 childproc_stopped(p, (p->p_flag & P_TRACED) ? 3032 CLD_TRAPPED : CLD_STOPPED); 3033 PROC_UNLOCK(p->p_pptr); 3034 PROC_SLOCK(p); 3035 } 3036 } 3037 3038 /* 3039 * Take the action for the specified signal 3040 * from the current set of pending signals. 3041 */ 3042 int 3043 postsig(int sig) 3044 { 3045 struct thread *td; 3046 struct proc *p; 3047 struct sigacts *ps; 3048 sig_t action; 3049 ksiginfo_t ksi; 3050 sigset_t returnmask; 3051 3052 KASSERT(sig != 0, ("postsig")); 3053 3054 td = curthread; 3055 p = td->td_proc; 3056 PROC_LOCK_ASSERT(p, MA_OWNED); 3057 ps = p->p_sigacts; 3058 mtx_assert(&ps->ps_mtx, MA_OWNED); 3059 ksiginfo_init(&ksi); 3060 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3061 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3062 return (0); 3063 ksi.ksi_signo = sig; 3064 if (ksi.ksi_code == SI_TIMER) 3065 itimer_accept(p, ksi.ksi_timerid, &ksi); 3066 action = ps->ps_sigact[_SIG_IDX(sig)]; 3067 #ifdef KTRACE 3068 if (KTRPOINT(td, KTR_PSIG)) 3069 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3070 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3071 #endif 3072 if ((p->p_stops & S_SIG) != 0) { 3073 mtx_unlock(&ps->ps_mtx); 3074 stopevent(p, S_SIG, sig); 3075 mtx_lock(&ps->ps_mtx); 3076 } 3077 3078 if (action == SIG_DFL) { 3079 /* 3080 * Default action, where the default is to kill 3081 * the process. (Other cases were ignored above.) 3082 */ 3083 mtx_unlock(&ps->ps_mtx); 3084 proc_td_siginfo_capture(td, &ksi.ksi_info); 3085 sigexit(td, sig); 3086 /* NOTREACHED */ 3087 } else { 3088 /* 3089 * If we get here, the signal must be caught. 3090 */ 3091 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3092 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3093 ("postsig action: blocked sig %d", sig)); 3094 3095 /* 3096 * Set the new mask value and also defer further 3097 * occurrences of this signal. 3098 * 3099 * Special case: user has done a sigsuspend. Here the 3100 * current mask is not of interest, but rather the 3101 * mask from before the sigsuspend is what we want 3102 * restored after the signal processing is completed. 3103 */ 3104 if (td->td_pflags & TDP_OLDMASK) { 3105 returnmask = td->td_oldsigmask; 3106 td->td_pflags &= ~TDP_OLDMASK; 3107 } else 3108 returnmask = td->td_sigmask; 3109 3110 if (p->p_sig == sig) { 3111 p->p_sig = 0; 3112 } 3113 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3114 postsig_done(sig, td, ps); 3115 } 3116 return (1); 3117 } 3118 3119 void 3120 proc_wkilled(struct proc *p) 3121 { 3122 3123 PROC_LOCK_ASSERT(p, MA_OWNED); 3124 if ((p->p_flag & P_WKILLED) == 0) { 3125 p->p_flag |= P_WKILLED; 3126 /* 3127 * Notify swapper that there is a process to swap in. 3128 * The notification is racy, at worst it would take 10 3129 * seconds for the swapper process to notice. 3130 */ 3131 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3132 wakeup(&proc0); 3133 } 3134 } 3135 3136 /* 3137 * Kill the current process for stated reason. 3138 */ 3139 void 3140 killproc(struct proc *p, char *why) 3141 { 3142 3143 PROC_LOCK_ASSERT(p, MA_OWNED); 3144 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3145 p->p_comm); 3146 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3147 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3148 p->p_ucred->cr_uid, why); 3149 proc_wkilled(p); 3150 kern_psignal(p, SIGKILL); 3151 } 3152 3153 /* 3154 * Force the current process to exit with the specified signal, dumping core 3155 * if appropriate. We bypass the normal tests for masked and caught signals, 3156 * allowing unrecoverable failures to terminate the process without changing 3157 * signal state. Mark the accounting record with the signal termination. 3158 * If dumping core, save the signal number for the debugger. Calls exit and 3159 * does not return. 3160 */ 3161 void 3162 sigexit(struct thread *td, int sig) 3163 { 3164 struct proc *p = td->td_proc; 3165 3166 PROC_LOCK_ASSERT(p, MA_OWNED); 3167 p->p_acflag |= AXSIG; 3168 /* 3169 * We must be single-threading to generate a core dump. This 3170 * ensures that the registers in the core file are up-to-date. 3171 * Also, the ELF dump handler assumes that the thread list doesn't 3172 * change out from under it. 3173 * 3174 * XXX If another thread attempts to single-thread before us 3175 * (e.g. via fork()), we won't get a dump at all. 3176 */ 3177 if ((sigprop(sig) & SIGPROP_CORE) && 3178 thread_single(p, SINGLE_NO_EXIT) == 0) { 3179 p->p_sig = sig; 3180 /* 3181 * Log signals which would cause core dumps 3182 * (Log as LOG_INFO to appease those who don't want 3183 * these messages.) 3184 * XXX : Todo, as well as euid, write out ruid too 3185 * Note that coredump() drops proc lock. 3186 */ 3187 if (coredump(td) == 0) 3188 sig |= WCOREFLAG; 3189 if (kern_logsigexit) 3190 log(LOG_INFO, 3191 "pid %d (%s), jid %d, uid %d: exited on " 3192 "signal %d%s\n", p->p_pid, p->p_comm, 3193 p->p_ucred->cr_prison->pr_id, 3194 td->td_ucred->cr_uid, 3195 sig &~ WCOREFLAG, 3196 sig & WCOREFLAG ? " (core dumped)" : ""); 3197 } else 3198 PROC_UNLOCK(p); 3199 exit1(td, 0, sig); 3200 /* NOTREACHED */ 3201 } 3202 3203 /* 3204 * Send queued SIGCHLD to parent when child process's state 3205 * is changed. 3206 */ 3207 static void 3208 sigparent(struct proc *p, int reason, int status) 3209 { 3210 PROC_LOCK_ASSERT(p, MA_OWNED); 3211 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3212 3213 if (p->p_ksi != NULL) { 3214 p->p_ksi->ksi_signo = SIGCHLD; 3215 p->p_ksi->ksi_code = reason; 3216 p->p_ksi->ksi_status = status; 3217 p->p_ksi->ksi_pid = p->p_pid; 3218 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3219 if (KSI_ONQ(p->p_ksi)) 3220 return; 3221 } 3222 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3223 } 3224 3225 static void 3226 childproc_jobstate(struct proc *p, int reason, int sig) 3227 { 3228 struct sigacts *ps; 3229 3230 PROC_LOCK_ASSERT(p, MA_OWNED); 3231 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3232 3233 /* 3234 * Wake up parent sleeping in kern_wait(), also send 3235 * SIGCHLD to parent, but SIGCHLD does not guarantee 3236 * that parent will awake, because parent may masked 3237 * the signal. 3238 */ 3239 p->p_pptr->p_flag |= P_STATCHILD; 3240 wakeup(p->p_pptr); 3241 3242 ps = p->p_pptr->p_sigacts; 3243 mtx_lock(&ps->ps_mtx); 3244 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3245 mtx_unlock(&ps->ps_mtx); 3246 sigparent(p, reason, sig); 3247 } else 3248 mtx_unlock(&ps->ps_mtx); 3249 } 3250 3251 void 3252 childproc_stopped(struct proc *p, int reason) 3253 { 3254 3255 childproc_jobstate(p, reason, p->p_xsig); 3256 } 3257 3258 void 3259 childproc_continued(struct proc *p) 3260 { 3261 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3262 } 3263 3264 void 3265 childproc_exited(struct proc *p) 3266 { 3267 int reason, status; 3268 3269 if (WCOREDUMP(p->p_xsig)) { 3270 reason = CLD_DUMPED; 3271 status = WTERMSIG(p->p_xsig); 3272 } else if (WIFSIGNALED(p->p_xsig)) { 3273 reason = CLD_KILLED; 3274 status = WTERMSIG(p->p_xsig); 3275 } else { 3276 reason = CLD_EXITED; 3277 status = p->p_xexit; 3278 } 3279 /* 3280 * XXX avoid calling wakeup(p->p_pptr), the work is 3281 * done in exit1(). 3282 */ 3283 sigparent(p, reason, status); 3284 } 3285 3286 #define MAX_NUM_CORE_FILES 100000 3287 #ifndef NUM_CORE_FILES 3288 #define NUM_CORE_FILES 5 3289 #endif 3290 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3291 static int num_cores = NUM_CORE_FILES; 3292 3293 static int 3294 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3295 { 3296 int error; 3297 int new_val; 3298 3299 new_val = num_cores; 3300 error = sysctl_handle_int(oidp, &new_val, 0, req); 3301 if (error != 0 || req->newptr == NULL) 3302 return (error); 3303 if (new_val > MAX_NUM_CORE_FILES) 3304 new_val = MAX_NUM_CORE_FILES; 3305 if (new_val < 0) 3306 new_val = 0; 3307 num_cores = new_val; 3308 return (0); 3309 } 3310 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3311 0, sizeof(int), sysctl_debug_num_cores_check, "I", 3312 "Maximum number of generated process corefiles while using index format"); 3313 3314 #define GZIP_SUFFIX ".gz" 3315 #define ZSTD_SUFFIX ".zst" 3316 3317 int compress_user_cores = 0; 3318 3319 static int 3320 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3321 { 3322 int error, val; 3323 3324 val = compress_user_cores; 3325 error = sysctl_handle_int(oidp, &val, 0, req); 3326 if (error != 0 || req->newptr == NULL) 3327 return (error); 3328 if (val != 0 && !compressor_avail(val)) 3329 return (EINVAL); 3330 compress_user_cores = val; 3331 return (error); 3332 } 3333 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, CTLTYPE_INT | CTLFLAG_RWTUN, 3334 0, sizeof(int), sysctl_compress_user_cores, "I", 3335 "Enable compression of user corefiles (" 3336 __XSTRING(COMPRESS_GZIP) " = gzip, " 3337 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3338 3339 int compress_user_cores_level = 6; 3340 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3341 &compress_user_cores_level, 0, 3342 "Corefile compression level"); 3343 3344 /* 3345 * Protect the access to corefilename[] by allproc_lock. 3346 */ 3347 #define corefilename_lock allproc_lock 3348 3349 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3350 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3351 3352 static int 3353 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3354 { 3355 int error; 3356 3357 sx_xlock(&corefilename_lock); 3358 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3359 req); 3360 sx_xunlock(&corefilename_lock); 3361 3362 return (error); 3363 } 3364 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3365 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3366 "Process corefile name format string"); 3367 3368 static void 3369 vnode_close_locked(struct thread *td, struct vnode *vp) 3370 { 3371 3372 VOP_UNLOCK(vp, 0); 3373 vn_close(vp, FWRITE, td->td_ucred, td); 3374 } 3375 3376 /* 3377 * If the core format has a %I in it, then we need to check 3378 * for existing corefiles before defining a name. 3379 * To do this we iterate over 0..ncores to find a 3380 * non-existing core file name to use. If all core files are 3381 * already used we choose the oldest one. 3382 */ 3383 static int 3384 corefile_open_last(struct thread *td, char *name, int indexpos, 3385 int indexlen, int ncores, struct vnode **vpp) 3386 { 3387 struct vnode *oldvp, *nextvp, *vp; 3388 struct vattr vattr; 3389 struct nameidata nd; 3390 int error, i, flags, oflags, cmode; 3391 char ch; 3392 struct timespec lasttime; 3393 3394 nextvp = oldvp = NULL; 3395 cmode = S_IRUSR | S_IWUSR; 3396 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3397 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3398 3399 for (i = 0; i < ncores; i++) { 3400 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3401 3402 ch = name[indexpos + indexlen]; 3403 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3404 i); 3405 name[indexpos + indexlen] = ch; 3406 3407 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3408 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3409 NULL); 3410 if (error != 0) 3411 break; 3412 3413 vp = nd.ni_vp; 3414 NDFREE(&nd, NDF_ONLY_PNBUF); 3415 if ((flags & O_CREAT) == O_CREAT) { 3416 nextvp = vp; 3417 break; 3418 } 3419 3420 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3421 if (error != 0) { 3422 vnode_close_locked(td, vp); 3423 break; 3424 } 3425 3426 if (oldvp == NULL || 3427 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3428 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3429 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3430 if (oldvp != NULL) 3431 vnode_close_locked(td, oldvp); 3432 oldvp = vp; 3433 lasttime = vattr.va_mtime; 3434 } else { 3435 vnode_close_locked(td, vp); 3436 } 3437 } 3438 3439 if (oldvp != NULL) { 3440 if (nextvp == NULL) { 3441 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3442 error = EFAULT; 3443 vnode_close_locked(td, oldvp); 3444 } else { 3445 nextvp = oldvp; 3446 } 3447 } else { 3448 vnode_close_locked(td, oldvp); 3449 } 3450 } 3451 if (error != 0) { 3452 if (nextvp != NULL) 3453 vnode_close_locked(td, oldvp); 3454 } else { 3455 *vpp = nextvp; 3456 } 3457 3458 return (error); 3459 } 3460 3461 /* 3462 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3463 * Expand the name described in corefilename, using name, uid, and pid 3464 * and open/create core file. 3465 * corefilename is a printf-like string, with three format specifiers: 3466 * %N name of process ("name") 3467 * %P process id (pid) 3468 * %U user id (uid) 3469 * For example, "%N.core" is the default; they can be disabled completely 3470 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3471 * This is controlled by the sysctl variable kern.corefile (see above). 3472 */ 3473 static int 3474 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3475 int compress, int signum, struct vnode **vpp, char **namep) 3476 { 3477 struct sbuf sb; 3478 struct nameidata nd; 3479 const char *format; 3480 char *hostname, *name; 3481 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3482 3483 hostname = NULL; 3484 format = corefilename; 3485 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3486 indexlen = 0; 3487 indexpos = -1; 3488 ncores = num_cores; 3489 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3490 sx_slock(&corefilename_lock); 3491 for (i = 0; format[i] != '\0'; i++) { 3492 switch (format[i]) { 3493 case '%': /* Format character */ 3494 i++; 3495 switch (format[i]) { 3496 case '%': 3497 sbuf_putc(&sb, '%'); 3498 break; 3499 case 'H': /* hostname */ 3500 if (hostname == NULL) { 3501 hostname = malloc(MAXHOSTNAMELEN, 3502 M_TEMP, M_WAITOK); 3503 } 3504 getcredhostname(td->td_ucred, hostname, 3505 MAXHOSTNAMELEN); 3506 sbuf_printf(&sb, "%s", hostname); 3507 break; 3508 case 'I': /* autoincrementing index */ 3509 if (indexpos != -1) { 3510 sbuf_printf(&sb, "%%I"); 3511 break; 3512 } 3513 3514 indexpos = sbuf_len(&sb); 3515 sbuf_printf(&sb, "%u", ncores - 1); 3516 indexlen = sbuf_len(&sb) - indexpos; 3517 break; 3518 case 'N': /* process name */ 3519 sbuf_printf(&sb, "%s", comm); 3520 break; 3521 case 'P': /* process id */ 3522 sbuf_printf(&sb, "%u", pid); 3523 break; 3524 case 'S': /* signal number */ 3525 sbuf_printf(&sb, "%i", signum); 3526 break; 3527 case 'U': /* user id */ 3528 sbuf_printf(&sb, "%u", uid); 3529 break; 3530 default: 3531 log(LOG_ERR, 3532 "Unknown format character %c in " 3533 "corename `%s'\n", format[i], format); 3534 break; 3535 } 3536 break; 3537 default: 3538 sbuf_putc(&sb, format[i]); 3539 break; 3540 } 3541 } 3542 sx_sunlock(&corefilename_lock); 3543 free(hostname, M_TEMP); 3544 if (compress == COMPRESS_GZIP) 3545 sbuf_printf(&sb, GZIP_SUFFIX); 3546 else if (compress == COMPRESS_ZSTD) 3547 sbuf_printf(&sb, ZSTD_SUFFIX); 3548 if (sbuf_error(&sb) != 0) { 3549 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3550 "long\n", (long)pid, comm, (u_long)uid); 3551 sbuf_delete(&sb); 3552 free(name, M_TEMP); 3553 return (ENOMEM); 3554 } 3555 sbuf_finish(&sb); 3556 sbuf_delete(&sb); 3557 3558 if (indexpos != -1) { 3559 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3560 vpp); 3561 if (error != 0) { 3562 log(LOG_ERR, 3563 "pid %d (%s), uid (%u): Path `%s' failed " 3564 "on initial open test, error = %d\n", 3565 pid, comm, uid, name, error); 3566 } 3567 } else { 3568 cmode = S_IRUSR | S_IWUSR; 3569 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3570 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3571 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3572 if ((td->td_proc->p_flag & P_SUGID) != 0) 3573 flags |= O_EXCL; 3574 3575 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3576 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3577 NULL); 3578 if (error == 0) { 3579 *vpp = nd.ni_vp; 3580 NDFREE(&nd, NDF_ONLY_PNBUF); 3581 } 3582 } 3583 3584 if (error != 0) { 3585 #ifdef AUDIT 3586 audit_proc_coredump(td, name, error); 3587 #endif 3588 free(name, M_TEMP); 3589 return (error); 3590 } 3591 *namep = name; 3592 return (0); 3593 } 3594 3595 /* 3596 * Dump a process' core. The main routine does some 3597 * policy checking, and creates the name of the coredump; 3598 * then it passes on a vnode and a size limit to the process-specific 3599 * coredump routine if there is one; if there _is not_ one, it returns 3600 * ENOSYS; otherwise it returns the error from the process-specific routine. 3601 */ 3602 3603 static int 3604 coredump(struct thread *td) 3605 { 3606 struct proc *p = td->td_proc; 3607 struct ucred *cred = td->td_ucred; 3608 struct vnode *vp; 3609 struct flock lf; 3610 struct vattr vattr; 3611 int error, error1, locked; 3612 char *name; /* name of corefile */ 3613 void *rl_cookie; 3614 off_t limit; 3615 char *fullpath, *freepath = NULL; 3616 struct sbuf *sb; 3617 3618 PROC_LOCK_ASSERT(p, MA_OWNED); 3619 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3620 _STOPEVENT(p, S_CORE, 0); 3621 3622 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3623 (p->p_flag2 & P2_NOTRACE) != 0) { 3624 PROC_UNLOCK(p); 3625 return (EFAULT); 3626 } 3627 3628 /* 3629 * Note that the bulk of limit checking is done after 3630 * the corefile is created. The exception is if the limit 3631 * for corefiles is 0, in which case we don't bother 3632 * creating the corefile at all. This layout means that 3633 * a corefile is truncated instead of not being created, 3634 * if it is larger than the limit. 3635 */ 3636 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3637 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3638 PROC_UNLOCK(p); 3639 return (EFBIG); 3640 } 3641 PROC_UNLOCK(p); 3642 3643 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3644 compress_user_cores, p->p_sig, &vp, &name); 3645 if (error != 0) 3646 return (error); 3647 3648 /* 3649 * Don't dump to non-regular files or files with links. 3650 * Do not dump into system files. Effective user must own the corefile. 3651 */ 3652 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3653 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 3654 vattr.va_uid != cred->cr_uid) { 3655 VOP_UNLOCK(vp, 0); 3656 error = EFAULT; 3657 goto out; 3658 } 3659 3660 VOP_UNLOCK(vp, 0); 3661 3662 /* Postpone other writers, including core dumps of other processes. */ 3663 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3664 3665 lf.l_whence = SEEK_SET; 3666 lf.l_start = 0; 3667 lf.l_len = 0; 3668 lf.l_type = F_WRLCK; 3669 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3670 3671 VATTR_NULL(&vattr); 3672 vattr.va_size = 0; 3673 if (set_core_nodump_flag) 3674 vattr.va_flags = UF_NODUMP; 3675 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3676 VOP_SETATTR(vp, &vattr, cred); 3677 VOP_UNLOCK(vp, 0); 3678 PROC_LOCK(p); 3679 p->p_acflag |= ACORE; 3680 PROC_UNLOCK(p); 3681 3682 if (p->p_sysent->sv_coredump != NULL) { 3683 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3684 } else { 3685 error = ENOSYS; 3686 } 3687 3688 if (locked) { 3689 lf.l_type = F_UNLCK; 3690 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3691 } 3692 vn_rangelock_unlock(vp, rl_cookie); 3693 3694 /* 3695 * Notify the userland helper that a process triggered a core dump. 3696 * This allows the helper to run an automated debugging session. 3697 */ 3698 if (error != 0 || coredump_devctl == 0) 3699 goto out; 3700 sb = sbuf_new_auto(); 3701 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3702 goto out2; 3703 sbuf_printf(sb, "comm=\""); 3704 devctl_safe_quote_sb(sb, fullpath); 3705 free(freepath, M_TEMP); 3706 sbuf_printf(sb, "\" core=\""); 3707 3708 /* 3709 * We can't lookup core file vp directly. When we're replacing a core, and 3710 * other random times, we flush the name cache, so it will fail. Instead, 3711 * if the path of the core is relative, add the current dir in front if it. 3712 */ 3713 if (name[0] != '/') { 3714 fullpath = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 3715 if (kern___getcwd(td, fullpath, UIO_SYSSPACE, MAXPATHLEN, MAXPATHLEN) != 0) { 3716 free(fullpath, M_TEMP); 3717 goto out2; 3718 } 3719 devctl_safe_quote_sb(sb, fullpath); 3720 free(fullpath, M_TEMP); 3721 sbuf_putc(sb, '/'); 3722 } 3723 devctl_safe_quote_sb(sb, name); 3724 sbuf_printf(sb, "\""); 3725 if (sbuf_finish(sb) == 0) 3726 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 3727 out2: 3728 sbuf_delete(sb); 3729 out: 3730 error1 = vn_close(vp, FWRITE, cred, td); 3731 if (error == 0) 3732 error = error1; 3733 #ifdef AUDIT 3734 audit_proc_coredump(td, name, error); 3735 #endif 3736 free(name, M_TEMP); 3737 return (error); 3738 } 3739 3740 /* 3741 * Nonexistent system call-- signal process (may want to handle it). Flag 3742 * error in case process won't see signal immediately (blocked or ignored). 3743 */ 3744 #ifndef _SYS_SYSPROTO_H_ 3745 struct nosys_args { 3746 int dummy; 3747 }; 3748 #endif 3749 /* ARGSUSED */ 3750 int 3751 nosys(struct thread *td, struct nosys_args *args) 3752 { 3753 struct proc *p; 3754 3755 p = td->td_proc; 3756 3757 PROC_LOCK(p); 3758 tdsignal(td, SIGSYS); 3759 PROC_UNLOCK(p); 3760 if (kern_lognosys == 1 || kern_lognosys == 3) { 3761 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3762 td->td_sa.code); 3763 } 3764 if (kern_lognosys == 2 || kern_lognosys == 3) { 3765 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3766 td->td_sa.code); 3767 } 3768 return (ENOSYS); 3769 } 3770 3771 /* 3772 * Send a SIGIO or SIGURG signal to a process or process group using stored 3773 * credentials rather than those of the current process. 3774 */ 3775 void 3776 pgsigio(struct sigio **sigiop, int sig, int checkctty) 3777 { 3778 ksiginfo_t ksi; 3779 struct sigio *sigio; 3780 3781 ksiginfo_init(&ksi); 3782 ksi.ksi_signo = sig; 3783 ksi.ksi_code = SI_KERNEL; 3784 3785 SIGIO_LOCK(); 3786 sigio = *sigiop; 3787 if (sigio == NULL) { 3788 SIGIO_UNLOCK(); 3789 return; 3790 } 3791 if (sigio->sio_pgid > 0) { 3792 PROC_LOCK(sigio->sio_proc); 3793 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3794 kern_psignal(sigio->sio_proc, sig); 3795 PROC_UNLOCK(sigio->sio_proc); 3796 } else if (sigio->sio_pgid < 0) { 3797 struct proc *p; 3798 3799 PGRP_LOCK(sigio->sio_pgrp); 3800 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3801 PROC_LOCK(p); 3802 if (p->p_state == PRS_NORMAL && 3803 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3804 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3805 kern_psignal(p, sig); 3806 PROC_UNLOCK(p); 3807 } 3808 PGRP_UNLOCK(sigio->sio_pgrp); 3809 } 3810 SIGIO_UNLOCK(); 3811 } 3812 3813 static int 3814 filt_sigattach(struct knote *kn) 3815 { 3816 struct proc *p = curproc; 3817 3818 kn->kn_ptr.p_proc = p; 3819 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3820 3821 knlist_add(p->p_klist, kn, 0); 3822 3823 return (0); 3824 } 3825 3826 static void 3827 filt_sigdetach(struct knote *kn) 3828 { 3829 struct proc *p = kn->kn_ptr.p_proc; 3830 3831 knlist_remove(p->p_klist, kn, 0); 3832 } 3833 3834 /* 3835 * signal knotes are shared with proc knotes, so we apply a mask to 3836 * the hint in order to differentiate them from process hints. This 3837 * could be avoided by using a signal-specific knote list, but probably 3838 * isn't worth the trouble. 3839 */ 3840 static int 3841 filt_signal(struct knote *kn, long hint) 3842 { 3843 3844 if (hint & NOTE_SIGNAL) { 3845 hint &= ~NOTE_SIGNAL; 3846 3847 if (kn->kn_id == hint) 3848 kn->kn_data++; 3849 } 3850 return (kn->kn_data != 0); 3851 } 3852 3853 struct sigacts * 3854 sigacts_alloc(void) 3855 { 3856 struct sigacts *ps; 3857 3858 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3859 refcount_init(&ps->ps_refcnt, 1); 3860 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3861 return (ps); 3862 } 3863 3864 void 3865 sigacts_free(struct sigacts *ps) 3866 { 3867 3868 if (refcount_release(&ps->ps_refcnt) == 0) 3869 return; 3870 mtx_destroy(&ps->ps_mtx); 3871 free(ps, M_SUBPROC); 3872 } 3873 3874 struct sigacts * 3875 sigacts_hold(struct sigacts *ps) 3876 { 3877 3878 refcount_acquire(&ps->ps_refcnt); 3879 return (ps); 3880 } 3881 3882 void 3883 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3884 { 3885 3886 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3887 mtx_lock(&src->ps_mtx); 3888 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3889 mtx_unlock(&src->ps_mtx); 3890 } 3891 3892 int 3893 sigacts_shared(struct sigacts *ps) 3894 { 3895 3896 return (ps->ps_refcnt > 1); 3897 } 3898 3899 void 3900 sig_drop_caught(struct proc *p) 3901 { 3902 int sig; 3903 struct sigacts *ps; 3904 3905 ps = p->p_sigacts; 3906 PROC_LOCK_ASSERT(p, MA_OWNED); 3907 mtx_assert(&ps->ps_mtx, MA_OWNED); 3908 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 3909 sig = sig_ffs(&ps->ps_sigcatch); 3910 sigdflt(ps, sig); 3911 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 3912 sigqueue_delete_proc(p, sig); 3913 } 3914 } 3915