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/posix4.h> 69 #include <sys/pioctl.h> 70 #include <sys/racct.h> 71 #include <sys/resourcevar.h> 72 #include <sys/sdt.h> 73 #include <sys/sbuf.h> 74 #include <sys/sleepqueue.h> 75 #include <sys/smp.h> 76 #include <sys/stat.h> 77 #include <sys/sx.h> 78 #include <sys/syscallsubr.h> 79 #include <sys/sysctl.h> 80 #include <sys/sysent.h> 81 #include <sys/syslog.h> 82 #include <sys/sysproto.h> 83 #include <sys/timers.h> 84 #include <sys/unistd.h> 85 #include <sys/wait.h> 86 #include <vm/vm.h> 87 #include <vm/vm_extern.h> 88 #include <vm/uma.h> 89 90 #include <sys/jail.h> 91 92 #include <machine/cpu.h> 93 94 #include <security/audit/audit.h> 95 96 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 97 98 SDT_PROVIDER_DECLARE(proc); 99 SDT_PROBE_DEFINE3(proc, , , signal__send, 100 "struct thread *", "struct proc *", "int"); 101 SDT_PROBE_DEFINE2(proc, , , signal__clear, 102 "int", "ksiginfo_t *"); 103 SDT_PROBE_DEFINE3(proc, , , signal__discard, 104 "struct thread *", "struct proc *", "int"); 105 106 static int coredump(struct thread *); 107 static int killpg1(struct thread *td, int sig, int pgid, int all, 108 ksiginfo_t *ksi); 109 static int issignal(struct thread *td); 110 static int sigprop(int sig); 111 static void tdsigwakeup(struct thread *, int, sig_t, int); 112 static int sig_suspend_threads(struct thread *, struct proc *, int); 113 static int filt_sigattach(struct knote *kn); 114 static void filt_sigdetach(struct knote *kn); 115 static int filt_signal(struct knote *kn, long hint); 116 static struct thread *sigtd(struct proc *p, int sig, int prop); 117 static void sigqueue_start(void); 118 119 static uma_zone_t ksiginfo_zone = NULL; 120 struct filterops sig_filtops = { 121 .f_isfd = 0, 122 .f_attach = filt_sigattach, 123 .f_detach = filt_sigdetach, 124 .f_event = filt_signal, 125 }; 126 127 static int kern_logsigexit = 1; 128 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 129 &kern_logsigexit, 0, 130 "Log processes quitting on abnormal signals to syslog(3)"); 131 132 static int kern_forcesigexit = 1; 133 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 134 &kern_forcesigexit, 0, "Force trap signal to be handled"); 135 136 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 137 "POSIX real time signal"); 138 139 static int max_pending_per_proc = 128; 140 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 141 &max_pending_per_proc, 0, "Max pending signals per proc"); 142 143 static int preallocate_siginfo = 1024; 144 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 145 &preallocate_siginfo, 0, "Preallocated signal memory size"); 146 147 static int signal_overflow = 0; 148 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 149 &signal_overflow, 0, "Number of signals overflew"); 150 151 static int signal_alloc_fail = 0; 152 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 153 &signal_alloc_fail, 0, "signals failed to be allocated"); 154 155 static int kern_lognosys = 0; 156 SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 157 "Log invalid syscalls"); 158 159 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 160 161 /* 162 * Policy -- Can ucred cr1 send SIGIO to process cr2? 163 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 164 * in the right situations. 165 */ 166 #define CANSIGIO(cr1, cr2) \ 167 ((cr1)->cr_uid == 0 || \ 168 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 169 (cr1)->cr_uid == (cr2)->cr_ruid || \ 170 (cr1)->cr_ruid == (cr2)->cr_uid || \ 171 (cr1)->cr_uid == (cr2)->cr_uid) 172 173 static int sugid_coredump; 174 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 175 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 176 177 static int capmode_coredump; 178 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 179 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 180 181 static int do_coredump = 1; 182 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 183 &do_coredump, 0, "Enable/Disable coredumps"); 184 185 static int set_core_nodump_flag = 0; 186 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 187 0, "Enable setting the NODUMP flag on coredump files"); 188 189 static int coredump_devctl = 0; 190 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 191 0, "Generate a devctl notification when processes coredump"); 192 193 /* 194 * Signal properties and actions. 195 * The array below categorizes the signals and their default actions 196 * according to the following properties: 197 */ 198 #define SIGPROP_KILL 0x01 /* terminates process by default */ 199 #define SIGPROP_CORE 0x02 /* ditto and coredumps */ 200 #define SIGPROP_STOP 0x04 /* suspend process */ 201 #define SIGPROP_TTYSTOP 0x08 /* ditto, from tty */ 202 #define SIGPROP_IGNORE 0x10 /* ignore by default */ 203 #define SIGPROP_CONT 0x20 /* continue if suspended */ 204 #define SIGPROP_CANTMASK 0x40 /* non-maskable, catchable */ 205 206 static int sigproptbl[NSIG] = { 207 [SIGHUP] = SIGPROP_KILL, 208 [SIGINT] = SIGPROP_KILL, 209 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE, 210 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE, 211 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE, 212 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE, 213 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE, 214 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE, 215 [SIGKILL] = SIGPROP_KILL, 216 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE, 217 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE, 218 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE, 219 [SIGPIPE] = SIGPROP_KILL, 220 [SIGALRM] = SIGPROP_KILL, 221 [SIGTERM] = SIGPROP_KILL, 222 [SIGURG] = SIGPROP_IGNORE, 223 [SIGSTOP] = SIGPROP_STOP, 224 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP, 225 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT, 226 [SIGCHLD] = SIGPROP_IGNORE, 227 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP, 228 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP, 229 [SIGIO] = SIGPROP_IGNORE, 230 [SIGXCPU] = SIGPROP_KILL, 231 [SIGXFSZ] = SIGPROP_KILL, 232 [SIGVTALRM] = SIGPROP_KILL, 233 [SIGPROF] = SIGPROP_KILL, 234 [SIGWINCH] = SIGPROP_IGNORE, 235 [SIGINFO] = SIGPROP_IGNORE, 236 [SIGUSR1] = SIGPROP_KILL, 237 [SIGUSR2] = SIGPROP_KILL, 238 }; 239 240 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 241 242 static void 243 sigqueue_start(void) 244 { 245 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 246 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 247 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 248 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 249 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 250 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 251 } 252 253 ksiginfo_t * 254 ksiginfo_alloc(int wait) 255 { 256 int flags; 257 258 flags = M_ZERO; 259 if (! wait) 260 flags |= M_NOWAIT; 261 if (ksiginfo_zone != NULL) 262 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 263 return (NULL); 264 } 265 266 void 267 ksiginfo_free(ksiginfo_t *ksi) 268 { 269 uma_zfree(ksiginfo_zone, ksi); 270 } 271 272 static __inline int 273 ksiginfo_tryfree(ksiginfo_t *ksi) 274 { 275 if (!(ksi->ksi_flags & KSI_EXT)) { 276 uma_zfree(ksiginfo_zone, ksi); 277 return (1); 278 } 279 return (0); 280 } 281 282 void 283 sigqueue_init(sigqueue_t *list, struct proc *p) 284 { 285 SIGEMPTYSET(list->sq_signals); 286 SIGEMPTYSET(list->sq_kill); 287 SIGEMPTYSET(list->sq_ptrace); 288 TAILQ_INIT(&list->sq_list); 289 list->sq_proc = p; 290 list->sq_flags = SQ_INIT; 291 } 292 293 /* 294 * Get a signal's ksiginfo. 295 * Return: 296 * 0 - signal not found 297 * others - signal number 298 */ 299 static int 300 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 301 { 302 struct proc *p = sq->sq_proc; 303 struct ksiginfo *ksi, *next; 304 int count = 0; 305 306 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 307 308 if (!SIGISMEMBER(sq->sq_signals, signo)) 309 return (0); 310 311 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 312 count++; 313 SIGDELSET(sq->sq_ptrace, signo); 314 si->ksi_flags |= KSI_PTRACE; 315 } 316 if (SIGISMEMBER(sq->sq_kill, signo)) { 317 count++; 318 if (count == 1) 319 SIGDELSET(sq->sq_kill, signo); 320 } 321 322 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 323 if (ksi->ksi_signo == signo) { 324 if (count == 0) { 325 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 326 ksi->ksi_sigq = NULL; 327 ksiginfo_copy(ksi, si); 328 if (ksiginfo_tryfree(ksi) && p != NULL) 329 p->p_pendingcnt--; 330 } 331 if (++count > 1) 332 break; 333 } 334 } 335 336 if (count <= 1) 337 SIGDELSET(sq->sq_signals, signo); 338 si->ksi_signo = signo; 339 return (signo); 340 } 341 342 void 343 sigqueue_take(ksiginfo_t *ksi) 344 { 345 struct ksiginfo *kp; 346 struct proc *p; 347 sigqueue_t *sq; 348 349 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 350 return; 351 352 p = sq->sq_proc; 353 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 354 ksi->ksi_sigq = NULL; 355 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 356 p->p_pendingcnt--; 357 358 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 359 kp = TAILQ_NEXT(kp, ksi_link)) { 360 if (kp->ksi_signo == ksi->ksi_signo) 361 break; 362 } 363 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 364 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 365 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 366 } 367 368 static int 369 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 370 { 371 struct proc *p = sq->sq_proc; 372 struct ksiginfo *ksi; 373 int ret = 0; 374 375 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 376 377 /* 378 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 379 * for these signals. 380 */ 381 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 382 SIGADDSET(sq->sq_kill, signo); 383 goto out_set_bit; 384 } 385 386 /* directly insert the ksi, don't copy it */ 387 if (si->ksi_flags & KSI_INS) { 388 if (si->ksi_flags & KSI_HEAD) 389 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 390 else 391 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 392 si->ksi_sigq = sq; 393 goto out_set_bit; 394 } 395 396 if (__predict_false(ksiginfo_zone == NULL)) { 397 SIGADDSET(sq->sq_kill, signo); 398 goto out_set_bit; 399 } 400 401 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 402 signal_overflow++; 403 ret = EAGAIN; 404 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 405 signal_alloc_fail++; 406 ret = EAGAIN; 407 } else { 408 if (p != NULL) 409 p->p_pendingcnt++; 410 ksiginfo_copy(si, ksi); 411 ksi->ksi_signo = signo; 412 if (si->ksi_flags & KSI_HEAD) 413 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 414 else 415 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 416 ksi->ksi_sigq = sq; 417 } 418 419 if (ret != 0) { 420 if ((si->ksi_flags & KSI_PTRACE) != 0) { 421 SIGADDSET(sq->sq_ptrace, signo); 422 ret = 0; 423 goto out_set_bit; 424 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 425 (si->ksi_flags & KSI_SIGQ) == 0) { 426 SIGADDSET(sq->sq_kill, signo); 427 ret = 0; 428 goto out_set_bit; 429 } 430 return (ret); 431 } 432 433 out_set_bit: 434 SIGADDSET(sq->sq_signals, signo); 435 return (ret); 436 } 437 438 void 439 sigqueue_flush(sigqueue_t *sq) 440 { 441 struct proc *p = sq->sq_proc; 442 ksiginfo_t *ksi; 443 444 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 445 446 if (p != NULL) 447 PROC_LOCK_ASSERT(p, MA_OWNED); 448 449 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 450 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 451 ksi->ksi_sigq = NULL; 452 if (ksiginfo_tryfree(ksi) && p != NULL) 453 p->p_pendingcnt--; 454 } 455 456 SIGEMPTYSET(sq->sq_signals); 457 SIGEMPTYSET(sq->sq_kill); 458 SIGEMPTYSET(sq->sq_ptrace); 459 } 460 461 static void 462 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 463 { 464 sigset_t tmp; 465 struct proc *p1, *p2; 466 ksiginfo_t *ksi, *next; 467 468 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 469 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 470 p1 = src->sq_proc; 471 p2 = dst->sq_proc; 472 /* Move siginfo to target list */ 473 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 474 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 475 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 476 if (p1 != NULL) 477 p1->p_pendingcnt--; 478 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 479 ksi->ksi_sigq = dst; 480 if (p2 != NULL) 481 p2->p_pendingcnt++; 482 } 483 } 484 485 /* Move pending bits to target list */ 486 tmp = src->sq_kill; 487 SIGSETAND(tmp, *set); 488 SIGSETOR(dst->sq_kill, tmp); 489 SIGSETNAND(src->sq_kill, tmp); 490 491 tmp = src->sq_ptrace; 492 SIGSETAND(tmp, *set); 493 SIGSETOR(dst->sq_ptrace, tmp); 494 SIGSETNAND(src->sq_ptrace, tmp); 495 496 tmp = src->sq_signals; 497 SIGSETAND(tmp, *set); 498 SIGSETOR(dst->sq_signals, tmp); 499 SIGSETNAND(src->sq_signals, tmp); 500 } 501 502 #if 0 503 static void 504 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 505 { 506 sigset_t set; 507 508 SIGEMPTYSET(set); 509 SIGADDSET(set, signo); 510 sigqueue_move_set(src, dst, &set); 511 } 512 #endif 513 514 static void 515 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 516 { 517 struct proc *p = sq->sq_proc; 518 ksiginfo_t *ksi, *next; 519 520 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 521 522 /* Remove siginfo queue */ 523 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 524 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 525 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 526 ksi->ksi_sigq = NULL; 527 if (ksiginfo_tryfree(ksi) && p != NULL) 528 p->p_pendingcnt--; 529 } 530 } 531 SIGSETNAND(sq->sq_kill, *set); 532 SIGSETNAND(sq->sq_ptrace, *set); 533 SIGSETNAND(sq->sq_signals, *set); 534 } 535 536 void 537 sigqueue_delete(sigqueue_t *sq, int signo) 538 { 539 sigset_t set; 540 541 SIGEMPTYSET(set); 542 SIGADDSET(set, signo); 543 sigqueue_delete_set(sq, &set); 544 } 545 546 /* Remove a set of signals for a process */ 547 static void 548 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 549 { 550 sigqueue_t worklist; 551 struct thread *td0; 552 553 PROC_LOCK_ASSERT(p, MA_OWNED); 554 555 sigqueue_init(&worklist, NULL); 556 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 557 558 FOREACH_THREAD_IN_PROC(p, td0) 559 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 560 561 sigqueue_flush(&worklist); 562 } 563 564 void 565 sigqueue_delete_proc(struct proc *p, int signo) 566 { 567 sigset_t set; 568 569 SIGEMPTYSET(set); 570 SIGADDSET(set, signo); 571 sigqueue_delete_set_proc(p, &set); 572 } 573 574 static void 575 sigqueue_delete_stopmask_proc(struct proc *p) 576 { 577 sigset_t set; 578 579 SIGEMPTYSET(set); 580 SIGADDSET(set, SIGSTOP); 581 SIGADDSET(set, SIGTSTP); 582 SIGADDSET(set, SIGTTIN); 583 SIGADDSET(set, SIGTTOU); 584 sigqueue_delete_set_proc(p, &set); 585 } 586 587 /* 588 * Determine signal that should be delivered to thread td, the current 589 * thread, 0 if none. If there is a pending stop signal with default 590 * action, the process stops in issignal(). 591 */ 592 int 593 cursig(struct thread *td) 594 { 595 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 596 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 597 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 598 return (SIGPENDING(td) ? issignal(td) : 0); 599 } 600 601 /* 602 * Arrange for ast() to handle unmasked pending signals on return to user 603 * mode. This must be called whenever a signal is added to td_sigqueue or 604 * unmasked in td_sigmask. 605 */ 606 void 607 signotify(struct thread *td) 608 { 609 610 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 611 612 if (SIGPENDING(td)) { 613 thread_lock(td); 614 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 615 thread_unlock(td); 616 } 617 } 618 619 /* 620 * Returns 1 (true) if altstack is configured for the thread, and the 621 * passed stack bottom address falls into the altstack range. Handles 622 * the 43 compat special case where the alt stack size is zero. 623 */ 624 int 625 sigonstack(size_t sp) 626 { 627 struct thread *td; 628 629 td = curthread; 630 if ((td->td_pflags & TDP_ALTSTACK) == 0) 631 return (0); 632 #if defined(COMPAT_43) 633 if (SV_PROC_FLAG(td->td_proc, SV_AOUT) && td->td_sigstk.ss_size == 0) 634 return ((td->td_sigstk.ss_flags & SS_ONSTACK) != 0); 635 #endif 636 return (sp >= (size_t)td->td_sigstk.ss_sp && 637 sp < td->td_sigstk.ss_size + (size_t)td->td_sigstk.ss_sp); 638 } 639 640 static __inline int 641 sigprop(int sig) 642 { 643 644 if (sig > 0 && sig < nitems(sigproptbl)) 645 return (sigproptbl[sig]); 646 return (0); 647 } 648 649 int 650 sig_ffs(sigset_t *set) 651 { 652 int i; 653 654 for (i = 0; i < _SIG_WORDS; i++) 655 if (set->__bits[i]) 656 return (ffs(set->__bits[i]) + (i * 32)); 657 return (0); 658 } 659 660 static bool 661 sigact_flag_test(const struct sigaction *act, int flag) 662 { 663 664 /* 665 * SA_SIGINFO is reset when signal disposition is set to 666 * ignore or default. Other flags are kept according to user 667 * settings. 668 */ 669 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 670 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 671 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 672 } 673 674 /* 675 * kern_sigaction 676 * sigaction 677 * freebsd4_sigaction 678 * osigaction 679 */ 680 int 681 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 682 struct sigaction *oact, int flags) 683 { 684 struct sigacts *ps; 685 struct proc *p = td->td_proc; 686 687 if (!_SIG_VALID(sig)) 688 return (EINVAL); 689 if (act != NULL && act->sa_handler != SIG_DFL && 690 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 691 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 692 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 693 return (EINVAL); 694 695 PROC_LOCK(p); 696 ps = p->p_sigacts; 697 mtx_lock(&ps->ps_mtx); 698 if (oact) { 699 memset(oact, 0, sizeof(*oact)); 700 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 701 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 702 oact->sa_flags |= SA_ONSTACK; 703 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 704 oact->sa_flags |= SA_RESTART; 705 if (SIGISMEMBER(ps->ps_sigreset, sig)) 706 oact->sa_flags |= SA_RESETHAND; 707 if (SIGISMEMBER(ps->ps_signodefer, sig)) 708 oact->sa_flags |= SA_NODEFER; 709 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 710 oact->sa_flags |= SA_SIGINFO; 711 oact->sa_sigaction = 712 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 713 } else 714 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 715 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 716 oact->sa_flags |= SA_NOCLDSTOP; 717 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 718 oact->sa_flags |= SA_NOCLDWAIT; 719 } 720 if (act) { 721 if ((sig == SIGKILL || sig == SIGSTOP) && 722 act->sa_handler != SIG_DFL) { 723 mtx_unlock(&ps->ps_mtx); 724 PROC_UNLOCK(p); 725 return (EINVAL); 726 } 727 728 /* 729 * Change setting atomically. 730 */ 731 732 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 733 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 734 if (sigact_flag_test(act, SA_SIGINFO)) { 735 ps->ps_sigact[_SIG_IDX(sig)] = 736 (__sighandler_t *)act->sa_sigaction; 737 SIGADDSET(ps->ps_siginfo, sig); 738 } else { 739 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 740 SIGDELSET(ps->ps_siginfo, sig); 741 } 742 if (!sigact_flag_test(act, SA_RESTART)) 743 SIGADDSET(ps->ps_sigintr, sig); 744 else 745 SIGDELSET(ps->ps_sigintr, sig); 746 if (sigact_flag_test(act, SA_ONSTACK)) 747 SIGADDSET(ps->ps_sigonstack, sig); 748 else 749 SIGDELSET(ps->ps_sigonstack, sig); 750 if (sigact_flag_test(act, SA_RESETHAND)) 751 SIGADDSET(ps->ps_sigreset, sig); 752 else 753 SIGDELSET(ps->ps_sigreset, sig); 754 if (sigact_flag_test(act, SA_NODEFER)) 755 SIGADDSET(ps->ps_signodefer, sig); 756 else 757 SIGDELSET(ps->ps_signodefer, sig); 758 if (sig == SIGCHLD) { 759 if (act->sa_flags & SA_NOCLDSTOP) 760 ps->ps_flag |= PS_NOCLDSTOP; 761 else 762 ps->ps_flag &= ~PS_NOCLDSTOP; 763 if (act->sa_flags & SA_NOCLDWAIT) { 764 /* 765 * Paranoia: since SA_NOCLDWAIT is implemented 766 * by reparenting the dying child to PID 1 (and 767 * trust it to reap the zombie), PID 1 itself 768 * is forbidden to set SA_NOCLDWAIT. 769 */ 770 if (p->p_pid == 1) 771 ps->ps_flag &= ~PS_NOCLDWAIT; 772 else 773 ps->ps_flag |= PS_NOCLDWAIT; 774 } else 775 ps->ps_flag &= ~PS_NOCLDWAIT; 776 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 777 ps->ps_flag |= PS_CLDSIGIGN; 778 else 779 ps->ps_flag &= ~PS_CLDSIGIGN; 780 } 781 /* 782 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 783 * and for signals set to SIG_DFL where the default is to 784 * ignore. However, don't put SIGCONT in ps_sigignore, as we 785 * have to restart the process. 786 */ 787 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 788 (sigprop(sig) & SIGPROP_IGNORE && 789 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 790 /* never to be seen again */ 791 sigqueue_delete_proc(p, sig); 792 if (sig != SIGCONT) 793 /* easier in psignal */ 794 SIGADDSET(ps->ps_sigignore, sig); 795 SIGDELSET(ps->ps_sigcatch, sig); 796 } else { 797 SIGDELSET(ps->ps_sigignore, sig); 798 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 799 SIGDELSET(ps->ps_sigcatch, sig); 800 else 801 SIGADDSET(ps->ps_sigcatch, sig); 802 } 803 #ifdef COMPAT_FREEBSD4 804 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 805 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 806 (flags & KSA_FREEBSD4) == 0) 807 SIGDELSET(ps->ps_freebsd4, sig); 808 else 809 SIGADDSET(ps->ps_freebsd4, sig); 810 #endif 811 #ifdef COMPAT_43 812 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 813 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 814 (flags & KSA_OSIGSET) == 0) 815 SIGDELSET(ps->ps_osigset, sig); 816 else 817 SIGADDSET(ps->ps_osigset, sig); 818 #endif 819 } 820 mtx_unlock(&ps->ps_mtx); 821 PROC_UNLOCK(p); 822 return (0); 823 } 824 825 #ifndef _SYS_SYSPROTO_H_ 826 struct sigaction_args { 827 int sig; 828 struct sigaction *act; 829 struct sigaction *oact; 830 }; 831 #endif 832 int 833 sys_sigaction(struct thread *td, struct sigaction_args *uap) 834 { 835 struct sigaction act, oact; 836 struct sigaction *actp, *oactp; 837 int error; 838 839 actp = (uap->act != NULL) ? &act : NULL; 840 oactp = (uap->oact != NULL) ? &oact : NULL; 841 if (actp) { 842 error = copyin(uap->act, actp, sizeof(act)); 843 if (error) 844 return (error); 845 } 846 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 847 if (oactp && !error) 848 error = copyout(oactp, uap->oact, sizeof(oact)); 849 return (error); 850 } 851 852 #ifdef COMPAT_FREEBSD4 853 #ifndef _SYS_SYSPROTO_H_ 854 struct freebsd4_sigaction_args { 855 int sig; 856 struct sigaction *act; 857 struct sigaction *oact; 858 }; 859 #endif 860 int 861 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 862 { 863 struct sigaction act, oact; 864 struct sigaction *actp, *oactp; 865 int error; 866 867 868 actp = (uap->act != NULL) ? &act : NULL; 869 oactp = (uap->oact != NULL) ? &oact : NULL; 870 if (actp) { 871 error = copyin(uap->act, actp, sizeof(act)); 872 if (error) 873 return (error); 874 } 875 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 876 if (oactp && !error) 877 error = copyout(oactp, uap->oact, sizeof(oact)); 878 return (error); 879 } 880 #endif /* COMAPT_FREEBSD4 */ 881 882 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 883 #ifndef _SYS_SYSPROTO_H_ 884 struct osigaction_args { 885 int signum; 886 struct osigaction *nsa; 887 struct osigaction *osa; 888 }; 889 #endif 890 int 891 osigaction(struct thread *td, struct osigaction_args *uap) 892 { 893 struct osigaction sa; 894 struct sigaction nsa, osa; 895 struct sigaction *nsap, *osap; 896 int error; 897 898 if (uap->signum <= 0 || uap->signum >= ONSIG) 899 return (EINVAL); 900 901 nsap = (uap->nsa != NULL) ? &nsa : NULL; 902 osap = (uap->osa != NULL) ? &osa : NULL; 903 904 if (nsap) { 905 error = copyin(uap->nsa, &sa, sizeof(sa)); 906 if (error) 907 return (error); 908 nsap->sa_handler = sa.sa_handler; 909 nsap->sa_flags = sa.sa_flags; 910 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 911 } 912 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 913 if (osap && !error) { 914 sa.sa_handler = osap->sa_handler; 915 sa.sa_flags = osap->sa_flags; 916 SIG2OSIG(osap->sa_mask, sa.sa_mask); 917 error = copyout(&sa, uap->osa, sizeof(sa)); 918 } 919 return (error); 920 } 921 922 #if !defined(__i386__) 923 /* Avoid replicating the same stub everywhere */ 924 int 925 osigreturn(struct thread *td, struct osigreturn_args *uap) 926 { 927 928 return (nosys(td, (struct nosys_args *)uap)); 929 } 930 #endif 931 #endif /* COMPAT_43 */ 932 933 /* 934 * Initialize signal state for process 0; 935 * set to ignore signals that are ignored by default. 936 */ 937 void 938 siginit(struct proc *p) 939 { 940 int i; 941 struct sigacts *ps; 942 943 PROC_LOCK(p); 944 ps = p->p_sigacts; 945 mtx_lock(&ps->ps_mtx); 946 for (i = 1; i <= NSIG; i++) { 947 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 948 SIGADDSET(ps->ps_sigignore, i); 949 } 950 } 951 mtx_unlock(&ps->ps_mtx); 952 PROC_UNLOCK(p); 953 } 954 955 /* 956 * Reset specified signal to the default disposition. 957 */ 958 static void 959 sigdflt(struct sigacts *ps, int sig) 960 { 961 962 mtx_assert(&ps->ps_mtx, MA_OWNED); 963 SIGDELSET(ps->ps_sigcatch, sig); 964 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 965 SIGADDSET(ps->ps_sigignore, sig); 966 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 967 SIGDELSET(ps->ps_siginfo, sig); 968 } 969 970 /* 971 * Reset signals for an exec of the specified process. 972 */ 973 void 974 execsigs(struct proc *p) 975 { 976 sigset_t osigignore; 977 struct sigacts *ps; 978 int sig; 979 struct thread *td; 980 981 /* 982 * Reset caught signals. Held signals remain held 983 * through td_sigmask (unless they were caught, 984 * and are now ignored by default). 985 */ 986 PROC_LOCK_ASSERT(p, MA_OWNED); 987 ps = p->p_sigacts; 988 mtx_lock(&ps->ps_mtx); 989 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 990 sig = sig_ffs(&ps->ps_sigcatch); 991 sigdflt(ps, sig); 992 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 993 sigqueue_delete_proc(p, sig); 994 } 995 996 /* 997 * As CloudABI processes cannot modify signal handlers, fully 998 * reset all signals to their default behavior. Do ignore 999 * SIGPIPE, as it would otherwise be impossible to recover from 1000 * writes to broken pipes and sockets. 1001 */ 1002 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 1003 osigignore = ps->ps_sigignore; 1004 while (SIGNOTEMPTY(osigignore)) { 1005 sig = sig_ffs(&osigignore); 1006 SIGDELSET(osigignore, sig); 1007 if (sig != SIGPIPE) 1008 sigdflt(ps, sig); 1009 } 1010 SIGADDSET(ps->ps_sigignore, SIGPIPE); 1011 } 1012 1013 /* 1014 * Reset stack state to the user stack. 1015 * Clear set of signals caught on the signal stack. 1016 */ 1017 td = curthread; 1018 MPASS(td->td_proc == p); 1019 td->td_sigstk.ss_flags = SS_DISABLE; 1020 td->td_sigstk.ss_size = 0; 1021 td->td_sigstk.ss_sp = 0; 1022 td->td_pflags &= ~TDP_ALTSTACK; 1023 /* 1024 * Reset no zombies if child dies flag as Solaris does. 1025 */ 1026 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1027 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1028 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1029 mtx_unlock(&ps->ps_mtx); 1030 } 1031 1032 /* 1033 * kern_sigprocmask() 1034 * 1035 * Manipulate signal mask. 1036 */ 1037 int 1038 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1039 int flags) 1040 { 1041 sigset_t new_block, oset1; 1042 struct proc *p; 1043 int error; 1044 1045 p = td->td_proc; 1046 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1047 PROC_LOCK_ASSERT(p, MA_OWNED); 1048 else 1049 PROC_LOCK(p); 1050 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1051 ? MA_OWNED : MA_NOTOWNED); 1052 if (oset != NULL) 1053 *oset = td->td_sigmask; 1054 1055 error = 0; 1056 if (set != NULL) { 1057 switch (how) { 1058 case SIG_BLOCK: 1059 SIG_CANTMASK(*set); 1060 oset1 = td->td_sigmask; 1061 SIGSETOR(td->td_sigmask, *set); 1062 new_block = td->td_sigmask; 1063 SIGSETNAND(new_block, oset1); 1064 break; 1065 case SIG_UNBLOCK: 1066 SIGSETNAND(td->td_sigmask, *set); 1067 signotify(td); 1068 goto out; 1069 case SIG_SETMASK: 1070 SIG_CANTMASK(*set); 1071 oset1 = td->td_sigmask; 1072 if (flags & SIGPROCMASK_OLD) 1073 SIGSETLO(td->td_sigmask, *set); 1074 else 1075 td->td_sigmask = *set; 1076 new_block = td->td_sigmask; 1077 SIGSETNAND(new_block, oset1); 1078 signotify(td); 1079 break; 1080 default: 1081 error = EINVAL; 1082 goto out; 1083 } 1084 1085 /* 1086 * The new_block set contains signals that were not previously 1087 * blocked, but are blocked now. 1088 * 1089 * In case we block any signal that was not previously blocked 1090 * for td, and process has the signal pending, try to schedule 1091 * signal delivery to some thread that does not block the 1092 * signal, possibly waking it up. 1093 */ 1094 if (p->p_numthreads != 1) 1095 reschedule_signals(p, new_block, flags); 1096 } 1097 1098 out: 1099 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1100 PROC_UNLOCK(p); 1101 return (error); 1102 } 1103 1104 #ifndef _SYS_SYSPROTO_H_ 1105 struct sigprocmask_args { 1106 int how; 1107 const sigset_t *set; 1108 sigset_t *oset; 1109 }; 1110 #endif 1111 int 1112 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1113 { 1114 sigset_t set, oset; 1115 sigset_t *setp, *osetp; 1116 int error; 1117 1118 setp = (uap->set != NULL) ? &set : NULL; 1119 osetp = (uap->oset != NULL) ? &oset : NULL; 1120 if (setp) { 1121 error = copyin(uap->set, setp, sizeof(set)); 1122 if (error) 1123 return (error); 1124 } 1125 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1126 if (osetp && !error) { 1127 error = copyout(osetp, uap->oset, sizeof(oset)); 1128 } 1129 return (error); 1130 } 1131 1132 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1133 #ifndef _SYS_SYSPROTO_H_ 1134 struct osigprocmask_args { 1135 int how; 1136 osigset_t mask; 1137 }; 1138 #endif 1139 int 1140 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1141 { 1142 sigset_t set, oset; 1143 int error; 1144 1145 OSIG2SIG(uap->mask, set); 1146 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1147 SIG2OSIG(oset, td->td_retval[0]); 1148 return (error); 1149 } 1150 #endif /* COMPAT_43 */ 1151 1152 int 1153 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1154 { 1155 ksiginfo_t ksi; 1156 sigset_t set; 1157 int error; 1158 1159 error = copyin(uap->set, &set, sizeof(set)); 1160 if (error) { 1161 td->td_retval[0] = error; 1162 return (0); 1163 } 1164 1165 error = kern_sigtimedwait(td, set, &ksi, NULL); 1166 if (error) { 1167 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1168 error = ERESTART; 1169 if (error == ERESTART) 1170 return (error); 1171 td->td_retval[0] = error; 1172 return (0); 1173 } 1174 1175 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1176 td->td_retval[0] = error; 1177 return (0); 1178 } 1179 1180 int 1181 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1182 { 1183 struct timespec ts; 1184 struct timespec *timeout; 1185 sigset_t set; 1186 ksiginfo_t ksi; 1187 int error; 1188 1189 if (uap->timeout) { 1190 error = copyin(uap->timeout, &ts, sizeof(ts)); 1191 if (error) 1192 return (error); 1193 1194 timeout = &ts; 1195 } else 1196 timeout = NULL; 1197 1198 error = copyin(uap->set, &set, sizeof(set)); 1199 if (error) 1200 return (error); 1201 1202 error = kern_sigtimedwait(td, set, &ksi, timeout); 1203 if (error) 1204 return (error); 1205 1206 if (uap->info) 1207 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1208 1209 if (error == 0) 1210 td->td_retval[0] = ksi.ksi_signo; 1211 return (error); 1212 } 1213 1214 int 1215 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1216 { 1217 ksiginfo_t ksi; 1218 sigset_t set; 1219 int error; 1220 1221 error = copyin(uap->set, &set, sizeof(set)); 1222 if (error) 1223 return (error); 1224 1225 error = kern_sigtimedwait(td, set, &ksi, NULL); 1226 if (error) 1227 return (error); 1228 1229 if (uap->info) 1230 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1231 1232 if (error == 0) 1233 td->td_retval[0] = ksi.ksi_signo; 1234 return (error); 1235 } 1236 1237 static void 1238 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1239 { 1240 struct thread *thr; 1241 1242 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1243 if (thr == td) 1244 thr->td_si = *si; 1245 else 1246 thr->td_si.si_signo = 0; 1247 } 1248 } 1249 1250 int 1251 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1252 struct timespec *timeout) 1253 { 1254 struct sigacts *ps; 1255 sigset_t saved_mask, new_block; 1256 struct proc *p; 1257 int error, sig, timo, timevalid = 0; 1258 struct timespec rts, ets, ts; 1259 struct timeval tv; 1260 1261 p = td->td_proc; 1262 error = 0; 1263 ets.tv_sec = 0; 1264 ets.tv_nsec = 0; 1265 1266 if (timeout != NULL) { 1267 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1268 timevalid = 1; 1269 getnanouptime(&rts); 1270 timespecadd(&rts, timeout, &ets); 1271 } 1272 } 1273 ksiginfo_init(ksi); 1274 /* Some signals can not be waited for. */ 1275 SIG_CANTMASK(waitset); 1276 ps = p->p_sigacts; 1277 PROC_LOCK(p); 1278 saved_mask = td->td_sigmask; 1279 SIGSETNAND(td->td_sigmask, waitset); 1280 for (;;) { 1281 mtx_lock(&ps->ps_mtx); 1282 sig = cursig(td); 1283 mtx_unlock(&ps->ps_mtx); 1284 KASSERT(sig >= 0, ("sig %d", sig)); 1285 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1286 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1287 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1288 error = 0; 1289 break; 1290 } 1291 } 1292 1293 if (error != 0) 1294 break; 1295 1296 /* 1297 * POSIX says this must be checked after looking for pending 1298 * signals. 1299 */ 1300 if (timeout != NULL) { 1301 if (!timevalid) { 1302 error = EINVAL; 1303 break; 1304 } 1305 getnanouptime(&rts); 1306 if (timespeccmp(&rts, &ets, >=)) { 1307 error = EAGAIN; 1308 break; 1309 } 1310 timespecsub(&ets, &rts, &ts); 1311 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1312 timo = tvtohz(&tv); 1313 } else { 1314 timo = 0; 1315 } 1316 1317 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1318 1319 if (timeout != NULL) { 1320 if (error == ERESTART) { 1321 /* Timeout can not be restarted. */ 1322 error = EINTR; 1323 } else if (error == EAGAIN) { 1324 /* We will calculate timeout by ourself. */ 1325 error = 0; 1326 } 1327 } 1328 } 1329 1330 new_block = saved_mask; 1331 SIGSETNAND(new_block, td->td_sigmask); 1332 td->td_sigmask = saved_mask; 1333 /* 1334 * Fewer signals can be delivered to us, reschedule signal 1335 * notification. 1336 */ 1337 if (p->p_numthreads != 1) 1338 reschedule_signals(p, new_block, 0); 1339 1340 if (error == 0) { 1341 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1342 1343 if (ksi->ksi_code == SI_TIMER) 1344 itimer_accept(p, ksi->ksi_timerid, ksi); 1345 1346 #ifdef KTRACE 1347 if (KTRPOINT(td, KTR_PSIG)) { 1348 sig_t action; 1349 1350 mtx_lock(&ps->ps_mtx); 1351 action = ps->ps_sigact[_SIG_IDX(sig)]; 1352 mtx_unlock(&ps->ps_mtx); 1353 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1354 } 1355 #endif 1356 if (sig == SIGKILL) { 1357 proc_td_siginfo_capture(td, &ksi->ksi_info); 1358 sigexit(td, sig); 1359 } 1360 } 1361 PROC_UNLOCK(p); 1362 return (error); 1363 } 1364 1365 #ifndef _SYS_SYSPROTO_H_ 1366 struct sigpending_args { 1367 sigset_t *set; 1368 }; 1369 #endif 1370 int 1371 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1372 { 1373 struct proc *p = td->td_proc; 1374 sigset_t pending; 1375 1376 PROC_LOCK(p); 1377 pending = p->p_sigqueue.sq_signals; 1378 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1379 PROC_UNLOCK(p); 1380 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1381 } 1382 1383 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1384 #ifndef _SYS_SYSPROTO_H_ 1385 struct osigpending_args { 1386 int dummy; 1387 }; 1388 #endif 1389 int 1390 osigpending(struct thread *td, struct osigpending_args *uap) 1391 { 1392 struct proc *p = td->td_proc; 1393 sigset_t pending; 1394 1395 PROC_LOCK(p); 1396 pending = p->p_sigqueue.sq_signals; 1397 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1398 PROC_UNLOCK(p); 1399 SIG2OSIG(pending, td->td_retval[0]); 1400 return (0); 1401 } 1402 #endif /* COMPAT_43 */ 1403 1404 #if defined(COMPAT_43) 1405 /* 1406 * Generalized interface signal handler, 4.3-compatible. 1407 */ 1408 #ifndef _SYS_SYSPROTO_H_ 1409 struct osigvec_args { 1410 int signum; 1411 struct sigvec *nsv; 1412 struct sigvec *osv; 1413 }; 1414 #endif 1415 /* ARGSUSED */ 1416 int 1417 osigvec(struct thread *td, struct osigvec_args *uap) 1418 { 1419 struct sigvec vec; 1420 struct sigaction nsa, osa; 1421 struct sigaction *nsap, *osap; 1422 int error; 1423 1424 if (uap->signum <= 0 || uap->signum >= ONSIG) 1425 return (EINVAL); 1426 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1427 osap = (uap->osv != NULL) ? &osa : NULL; 1428 if (nsap) { 1429 error = copyin(uap->nsv, &vec, sizeof(vec)); 1430 if (error) 1431 return (error); 1432 nsap->sa_handler = vec.sv_handler; 1433 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1434 nsap->sa_flags = vec.sv_flags; 1435 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1436 } 1437 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1438 if (osap && !error) { 1439 vec.sv_handler = osap->sa_handler; 1440 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1441 vec.sv_flags = osap->sa_flags; 1442 vec.sv_flags &= ~SA_NOCLDWAIT; 1443 vec.sv_flags ^= SA_RESTART; 1444 error = copyout(&vec, uap->osv, sizeof(vec)); 1445 } 1446 return (error); 1447 } 1448 1449 #ifndef _SYS_SYSPROTO_H_ 1450 struct osigblock_args { 1451 int mask; 1452 }; 1453 #endif 1454 int 1455 osigblock(struct thread *td, struct osigblock_args *uap) 1456 { 1457 sigset_t set, oset; 1458 1459 OSIG2SIG(uap->mask, set); 1460 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1461 SIG2OSIG(oset, td->td_retval[0]); 1462 return (0); 1463 } 1464 1465 #ifndef _SYS_SYSPROTO_H_ 1466 struct osigsetmask_args { 1467 int mask; 1468 }; 1469 #endif 1470 int 1471 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1472 { 1473 sigset_t set, oset; 1474 1475 OSIG2SIG(uap->mask, set); 1476 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1477 SIG2OSIG(oset, td->td_retval[0]); 1478 return (0); 1479 } 1480 #endif /* COMPAT_43 */ 1481 1482 /* 1483 * Suspend calling thread until signal, providing mask to be set in the 1484 * meantime. 1485 */ 1486 #ifndef _SYS_SYSPROTO_H_ 1487 struct sigsuspend_args { 1488 const sigset_t *sigmask; 1489 }; 1490 #endif 1491 /* ARGSUSED */ 1492 int 1493 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1494 { 1495 sigset_t mask; 1496 int error; 1497 1498 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1499 if (error) 1500 return (error); 1501 return (kern_sigsuspend(td, mask)); 1502 } 1503 1504 int 1505 kern_sigsuspend(struct thread *td, sigset_t mask) 1506 { 1507 struct proc *p = td->td_proc; 1508 int has_sig, sig; 1509 1510 /* 1511 * When returning from sigsuspend, we want 1512 * the old mask to be restored after the 1513 * signal handler has finished. Thus, we 1514 * save it here and mark the sigacts structure 1515 * to indicate this. 1516 */ 1517 PROC_LOCK(p); 1518 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1519 SIGPROCMASK_PROC_LOCKED); 1520 td->td_pflags |= TDP_OLDMASK; 1521 1522 /* 1523 * Process signals now. Otherwise, we can get spurious wakeup 1524 * due to signal entered process queue, but delivered to other 1525 * thread. But sigsuspend should return only on signal 1526 * delivery. 1527 */ 1528 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1529 for (has_sig = 0; !has_sig;) { 1530 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1531 0) == 0) 1532 /* void */; 1533 thread_suspend_check(0); 1534 mtx_lock(&p->p_sigacts->ps_mtx); 1535 while ((sig = cursig(td)) != 0) { 1536 KASSERT(sig >= 0, ("sig %d", sig)); 1537 has_sig += postsig(sig); 1538 } 1539 mtx_unlock(&p->p_sigacts->ps_mtx); 1540 } 1541 PROC_UNLOCK(p); 1542 td->td_errno = EINTR; 1543 td->td_pflags |= TDP_NERRNO; 1544 return (EJUSTRETURN); 1545 } 1546 1547 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1548 /* 1549 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1550 * convention: libc stub passes mask, not pointer, to save a copyin. 1551 */ 1552 #ifndef _SYS_SYSPROTO_H_ 1553 struct osigsuspend_args { 1554 osigset_t mask; 1555 }; 1556 #endif 1557 /* ARGSUSED */ 1558 int 1559 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1560 { 1561 sigset_t mask; 1562 1563 OSIG2SIG(uap->mask, mask); 1564 return (kern_sigsuspend(td, mask)); 1565 } 1566 #endif /* COMPAT_43 */ 1567 1568 #if defined(COMPAT_43) 1569 #ifndef _SYS_SYSPROTO_H_ 1570 struct osigstack_args { 1571 struct sigstack *nss; 1572 struct sigstack *oss; 1573 }; 1574 #endif 1575 /* ARGSUSED */ 1576 int 1577 osigstack(struct thread *td, struct osigstack_args *uap) 1578 { 1579 struct sigstack nss, oss; 1580 int error = 0; 1581 1582 if (uap->nss != NULL) { 1583 error = copyin(uap->nss, &nss, sizeof(nss)); 1584 if (error) 1585 return (error); 1586 } 1587 oss.ss_sp = td->td_sigstk.ss_sp; 1588 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1589 if (uap->nss != NULL) { 1590 td->td_sigstk.ss_sp = nss.ss_sp; 1591 td->td_sigstk.ss_size = 0; 1592 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1593 td->td_pflags |= TDP_ALTSTACK; 1594 } 1595 if (uap->oss != NULL) 1596 error = copyout(&oss, uap->oss, sizeof(oss)); 1597 1598 return (error); 1599 } 1600 #endif /* COMPAT_43 */ 1601 1602 #ifndef _SYS_SYSPROTO_H_ 1603 struct sigaltstack_args { 1604 stack_t *ss; 1605 stack_t *oss; 1606 }; 1607 #endif 1608 /* ARGSUSED */ 1609 int 1610 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1611 { 1612 stack_t ss, oss; 1613 int error; 1614 1615 if (uap->ss != NULL) { 1616 error = copyin(uap->ss, &ss, sizeof(ss)); 1617 if (error) 1618 return (error); 1619 } 1620 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1621 (uap->oss != NULL) ? &oss : NULL); 1622 if (error) 1623 return (error); 1624 if (uap->oss != NULL) 1625 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1626 return (error); 1627 } 1628 1629 int 1630 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1631 { 1632 struct proc *p = td->td_proc; 1633 int oonstack; 1634 1635 oonstack = sigonstack(cpu_getstack(td)); 1636 1637 if (oss != NULL) { 1638 *oss = td->td_sigstk; 1639 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1640 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1641 } 1642 1643 if (ss != NULL) { 1644 if (oonstack) 1645 return (EPERM); 1646 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1647 return (EINVAL); 1648 if (!(ss->ss_flags & SS_DISABLE)) { 1649 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1650 return (ENOMEM); 1651 1652 td->td_sigstk = *ss; 1653 td->td_pflags |= TDP_ALTSTACK; 1654 } else { 1655 td->td_pflags &= ~TDP_ALTSTACK; 1656 } 1657 } 1658 return (0); 1659 } 1660 1661 /* 1662 * Common code for kill process group/broadcast kill. 1663 * cp is calling process. 1664 */ 1665 static int 1666 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1667 { 1668 struct proc *p; 1669 struct pgrp *pgrp; 1670 int err; 1671 int ret; 1672 1673 ret = ESRCH; 1674 if (all) { 1675 /* 1676 * broadcast 1677 */ 1678 sx_slock(&allproc_lock); 1679 FOREACH_PROC_IN_SYSTEM(p) { 1680 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1681 p == td->td_proc || p->p_state == PRS_NEW) { 1682 continue; 1683 } 1684 PROC_LOCK(p); 1685 err = p_cansignal(td, p, sig); 1686 if (err == 0) { 1687 if (sig) 1688 pksignal(p, sig, ksi); 1689 ret = err; 1690 } 1691 else if (ret == ESRCH) 1692 ret = err; 1693 PROC_UNLOCK(p); 1694 } 1695 sx_sunlock(&allproc_lock); 1696 } else { 1697 sx_slock(&proctree_lock); 1698 if (pgid == 0) { 1699 /* 1700 * zero pgid means send to my process group. 1701 */ 1702 pgrp = td->td_proc->p_pgrp; 1703 PGRP_LOCK(pgrp); 1704 } else { 1705 pgrp = pgfind(pgid); 1706 if (pgrp == NULL) { 1707 sx_sunlock(&proctree_lock); 1708 return (ESRCH); 1709 } 1710 } 1711 sx_sunlock(&proctree_lock); 1712 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1713 PROC_LOCK(p); 1714 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1715 p->p_state == PRS_NEW) { 1716 PROC_UNLOCK(p); 1717 continue; 1718 } 1719 err = p_cansignal(td, p, sig); 1720 if (err == 0) { 1721 if (sig) 1722 pksignal(p, sig, ksi); 1723 ret = err; 1724 } 1725 else if (ret == ESRCH) 1726 ret = err; 1727 PROC_UNLOCK(p); 1728 } 1729 PGRP_UNLOCK(pgrp); 1730 } 1731 return (ret); 1732 } 1733 1734 #ifndef _SYS_SYSPROTO_H_ 1735 struct kill_args { 1736 int pid; 1737 int signum; 1738 }; 1739 #endif 1740 /* ARGSUSED */ 1741 int 1742 sys_kill(struct thread *td, struct kill_args *uap) 1743 { 1744 ksiginfo_t ksi; 1745 struct proc *p; 1746 int error; 1747 1748 /* 1749 * A process in capability mode can send signals only to himself. 1750 * The main rationale behind this is that abort(3) is implemented as 1751 * kill(getpid(), SIGABRT). 1752 */ 1753 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1754 return (ECAPMODE); 1755 1756 AUDIT_ARG_SIGNUM(uap->signum); 1757 AUDIT_ARG_PID(uap->pid); 1758 if ((u_int)uap->signum > _SIG_MAXSIG) 1759 return (EINVAL); 1760 1761 ksiginfo_init(&ksi); 1762 ksi.ksi_signo = uap->signum; 1763 ksi.ksi_code = SI_USER; 1764 ksi.ksi_pid = td->td_proc->p_pid; 1765 ksi.ksi_uid = td->td_ucred->cr_ruid; 1766 1767 if (uap->pid > 0) { 1768 /* kill single process */ 1769 if ((p = pfind_any(uap->pid)) == NULL) 1770 return (ESRCH); 1771 AUDIT_ARG_PROCESS(p); 1772 error = p_cansignal(td, p, uap->signum); 1773 if (error == 0 && uap->signum) 1774 pksignal(p, uap->signum, &ksi); 1775 PROC_UNLOCK(p); 1776 return (error); 1777 } 1778 switch (uap->pid) { 1779 case -1: /* broadcast signal */ 1780 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1781 case 0: /* signal own process group */ 1782 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1783 default: /* negative explicit process group */ 1784 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1785 } 1786 /* NOTREACHED */ 1787 } 1788 1789 int 1790 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1791 { 1792 struct proc *p; 1793 int error; 1794 1795 AUDIT_ARG_SIGNUM(uap->signum); 1796 AUDIT_ARG_FD(uap->fd); 1797 if ((u_int)uap->signum > _SIG_MAXSIG) 1798 return (EINVAL); 1799 1800 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1801 if (error) 1802 return (error); 1803 AUDIT_ARG_PROCESS(p); 1804 error = p_cansignal(td, p, uap->signum); 1805 if (error == 0 && uap->signum) 1806 kern_psignal(p, uap->signum); 1807 PROC_UNLOCK(p); 1808 return (error); 1809 } 1810 1811 #if defined(COMPAT_43) 1812 #ifndef _SYS_SYSPROTO_H_ 1813 struct okillpg_args { 1814 int pgid; 1815 int signum; 1816 }; 1817 #endif 1818 /* ARGSUSED */ 1819 int 1820 okillpg(struct thread *td, struct okillpg_args *uap) 1821 { 1822 ksiginfo_t ksi; 1823 1824 AUDIT_ARG_SIGNUM(uap->signum); 1825 AUDIT_ARG_PID(uap->pgid); 1826 if ((u_int)uap->signum > _SIG_MAXSIG) 1827 return (EINVAL); 1828 1829 ksiginfo_init(&ksi); 1830 ksi.ksi_signo = uap->signum; 1831 ksi.ksi_code = SI_USER; 1832 ksi.ksi_pid = td->td_proc->p_pid; 1833 ksi.ksi_uid = td->td_ucred->cr_ruid; 1834 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1835 } 1836 #endif /* COMPAT_43 */ 1837 1838 #ifndef _SYS_SYSPROTO_H_ 1839 struct sigqueue_args { 1840 pid_t pid; 1841 int signum; 1842 /* union sigval */ void *value; 1843 }; 1844 #endif 1845 int 1846 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1847 { 1848 union sigval sv; 1849 1850 sv.sival_ptr = uap->value; 1851 1852 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1853 } 1854 1855 int 1856 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1857 { 1858 ksiginfo_t ksi; 1859 struct proc *p; 1860 int error; 1861 1862 if ((u_int)signum > _SIG_MAXSIG) 1863 return (EINVAL); 1864 1865 /* 1866 * Specification says sigqueue can only send signal to 1867 * single process. 1868 */ 1869 if (pid <= 0) 1870 return (EINVAL); 1871 1872 if ((p = pfind_any(pid)) == NULL) 1873 return (ESRCH); 1874 error = p_cansignal(td, p, signum); 1875 if (error == 0 && signum != 0) { 1876 ksiginfo_init(&ksi); 1877 ksi.ksi_flags = KSI_SIGQ; 1878 ksi.ksi_signo = signum; 1879 ksi.ksi_code = SI_QUEUE; 1880 ksi.ksi_pid = td->td_proc->p_pid; 1881 ksi.ksi_uid = td->td_ucred->cr_ruid; 1882 ksi.ksi_value = *value; 1883 error = pksignal(p, ksi.ksi_signo, &ksi); 1884 } 1885 PROC_UNLOCK(p); 1886 return (error); 1887 } 1888 1889 /* 1890 * Send a signal to a process group. 1891 */ 1892 void 1893 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1894 { 1895 struct pgrp *pgrp; 1896 1897 if (pgid != 0) { 1898 sx_slock(&proctree_lock); 1899 pgrp = pgfind(pgid); 1900 sx_sunlock(&proctree_lock); 1901 if (pgrp != NULL) { 1902 pgsignal(pgrp, sig, 0, ksi); 1903 PGRP_UNLOCK(pgrp); 1904 } 1905 } 1906 } 1907 1908 /* 1909 * Send a signal to a process group. If checktty is 1, 1910 * limit to members which have a controlling terminal. 1911 */ 1912 void 1913 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1914 { 1915 struct proc *p; 1916 1917 if (pgrp) { 1918 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1919 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1920 PROC_LOCK(p); 1921 if (p->p_state == PRS_NORMAL && 1922 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1923 pksignal(p, sig, ksi); 1924 PROC_UNLOCK(p); 1925 } 1926 } 1927 } 1928 1929 1930 /* 1931 * Recalculate the signal mask and reset the signal disposition after 1932 * usermode frame for delivery is formed. Should be called after 1933 * mach-specific routine, because sysent->sv_sendsig() needs correct 1934 * ps_siginfo and signal mask. 1935 */ 1936 static void 1937 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1938 { 1939 sigset_t mask; 1940 1941 mtx_assert(&ps->ps_mtx, MA_OWNED); 1942 td->td_ru.ru_nsignals++; 1943 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1944 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1945 SIGADDSET(mask, sig); 1946 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1947 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1948 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1949 sigdflt(ps, sig); 1950 } 1951 1952 1953 /* 1954 * Send a signal caused by a trap to the current thread. If it will be 1955 * caught immediately, deliver it with correct code. Otherwise, post it 1956 * normally. 1957 */ 1958 void 1959 trapsignal(struct thread *td, ksiginfo_t *ksi) 1960 { 1961 struct sigacts *ps; 1962 struct proc *p; 1963 int sig; 1964 int code; 1965 1966 p = td->td_proc; 1967 sig = ksi->ksi_signo; 1968 code = ksi->ksi_code; 1969 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1970 1971 PROC_LOCK(p); 1972 ps = p->p_sigacts; 1973 mtx_lock(&ps->ps_mtx); 1974 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1975 !SIGISMEMBER(td->td_sigmask, sig)) { 1976 #ifdef KTRACE 1977 if (KTRPOINT(curthread, KTR_PSIG)) 1978 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1979 &td->td_sigmask, code); 1980 #endif 1981 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1982 ksi, &td->td_sigmask); 1983 postsig_done(sig, td, ps); 1984 mtx_unlock(&ps->ps_mtx); 1985 } else { 1986 /* 1987 * Avoid a possible infinite loop if the thread 1988 * masking the signal or process is ignoring the 1989 * signal. 1990 */ 1991 if (kern_forcesigexit && 1992 (SIGISMEMBER(td->td_sigmask, sig) || 1993 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1994 SIGDELSET(td->td_sigmask, sig); 1995 SIGDELSET(ps->ps_sigcatch, sig); 1996 SIGDELSET(ps->ps_sigignore, sig); 1997 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1998 } 1999 mtx_unlock(&ps->ps_mtx); 2000 p->p_sig = sig; /* XXX to verify code */ 2001 tdsendsignal(p, td, sig, ksi); 2002 } 2003 PROC_UNLOCK(p); 2004 } 2005 2006 static struct thread * 2007 sigtd(struct proc *p, int sig, int prop) 2008 { 2009 struct thread *td, *signal_td; 2010 2011 PROC_LOCK_ASSERT(p, MA_OWNED); 2012 2013 /* 2014 * Check if current thread can handle the signal without 2015 * switching context to another thread. 2016 */ 2017 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2018 return (curthread); 2019 signal_td = NULL; 2020 FOREACH_THREAD_IN_PROC(p, td) { 2021 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2022 signal_td = td; 2023 break; 2024 } 2025 } 2026 if (signal_td == NULL) 2027 signal_td = FIRST_THREAD_IN_PROC(p); 2028 return (signal_td); 2029 } 2030 2031 /* 2032 * Send the signal to the process. If the signal has an action, the action 2033 * is usually performed by the target process rather than the caller; we add 2034 * the signal to the set of pending signals for the process. 2035 * 2036 * Exceptions: 2037 * o When a stop signal is sent to a sleeping process that takes the 2038 * default action, the process is stopped without awakening it. 2039 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2040 * regardless of the signal action (eg, blocked or ignored). 2041 * 2042 * Other ignored signals are discarded immediately. 2043 * 2044 * NB: This function may be entered from the debugger via the "kill" DDB 2045 * command. There is little that can be done to mitigate the possibly messy 2046 * side effects of this unwise possibility. 2047 */ 2048 void 2049 kern_psignal(struct proc *p, int sig) 2050 { 2051 ksiginfo_t ksi; 2052 2053 ksiginfo_init(&ksi); 2054 ksi.ksi_signo = sig; 2055 ksi.ksi_code = SI_KERNEL; 2056 (void) tdsendsignal(p, NULL, sig, &ksi); 2057 } 2058 2059 int 2060 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2061 { 2062 2063 return (tdsendsignal(p, NULL, sig, ksi)); 2064 } 2065 2066 /* Utility function for finding a thread to send signal event to. */ 2067 int 2068 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2069 { 2070 struct thread *td; 2071 2072 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2073 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2074 if (td == NULL) 2075 return (ESRCH); 2076 *ttd = td; 2077 } else { 2078 *ttd = NULL; 2079 PROC_LOCK(p); 2080 } 2081 return (0); 2082 } 2083 2084 void 2085 tdsignal(struct thread *td, int sig) 2086 { 2087 ksiginfo_t ksi; 2088 2089 ksiginfo_init(&ksi); 2090 ksi.ksi_signo = sig; 2091 ksi.ksi_code = SI_KERNEL; 2092 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2093 } 2094 2095 void 2096 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2097 { 2098 2099 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2100 } 2101 2102 int 2103 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2104 { 2105 sig_t action; 2106 sigqueue_t *sigqueue; 2107 int prop; 2108 struct sigacts *ps; 2109 int intrval; 2110 int ret = 0; 2111 int wakeup_swapper; 2112 2113 MPASS(td == NULL || p == td->td_proc); 2114 PROC_LOCK_ASSERT(p, MA_OWNED); 2115 2116 if (!_SIG_VALID(sig)) 2117 panic("%s(): invalid signal %d", __func__, sig); 2118 2119 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2120 2121 /* 2122 * IEEE Std 1003.1-2001: return success when killing a zombie. 2123 */ 2124 if (p->p_state == PRS_ZOMBIE) { 2125 if (ksi && (ksi->ksi_flags & KSI_INS)) 2126 ksiginfo_tryfree(ksi); 2127 return (ret); 2128 } 2129 2130 ps = p->p_sigacts; 2131 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2132 prop = sigprop(sig); 2133 2134 if (td == NULL) { 2135 td = sigtd(p, sig, prop); 2136 sigqueue = &p->p_sigqueue; 2137 } else 2138 sigqueue = &td->td_sigqueue; 2139 2140 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2141 2142 /* 2143 * If the signal is being ignored, 2144 * then we forget about it immediately. 2145 * (Note: we don't set SIGCONT in ps_sigignore, 2146 * and if it is set to SIG_IGN, 2147 * action will be SIG_DFL here.) 2148 */ 2149 mtx_lock(&ps->ps_mtx); 2150 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2151 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2152 2153 mtx_unlock(&ps->ps_mtx); 2154 if (ksi && (ksi->ksi_flags & KSI_INS)) 2155 ksiginfo_tryfree(ksi); 2156 return (ret); 2157 } 2158 if (SIGISMEMBER(td->td_sigmask, sig)) 2159 action = SIG_HOLD; 2160 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2161 action = SIG_CATCH; 2162 else 2163 action = SIG_DFL; 2164 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2165 intrval = EINTR; 2166 else 2167 intrval = ERESTART; 2168 mtx_unlock(&ps->ps_mtx); 2169 2170 if (prop & SIGPROP_CONT) 2171 sigqueue_delete_stopmask_proc(p); 2172 else if (prop & SIGPROP_STOP) { 2173 /* 2174 * If sending a tty stop signal to a member of an orphaned 2175 * process group, discard the signal here if the action 2176 * is default; don't stop the process below if sleeping, 2177 * and don't clear any pending SIGCONT. 2178 */ 2179 if ((prop & SIGPROP_TTYSTOP) && 2180 (p->p_pgrp->pg_jobc == 0) && 2181 (action == SIG_DFL)) { 2182 if (ksi && (ksi->ksi_flags & KSI_INS)) 2183 ksiginfo_tryfree(ksi); 2184 return (ret); 2185 } 2186 sigqueue_delete_proc(p, SIGCONT); 2187 if (p->p_flag & P_CONTINUED) { 2188 p->p_flag &= ~P_CONTINUED; 2189 PROC_LOCK(p->p_pptr); 2190 sigqueue_take(p->p_ksi); 2191 PROC_UNLOCK(p->p_pptr); 2192 } 2193 } 2194 2195 ret = sigqueue_add(sigqueue, sig, ksi); 2196 if (ret != 0) 2197 return (ret); 2198 signotify(td); 2199 /* 2200 * Defer further processing for signals which are held, 2201 * except that stopped processes must be continued by SIGCONT. 2202 */ 2203 if (action == SIG_HOLD && 2204 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2205 return (ret); 2206 2207 /* SIGKILL: Remove procfs STOPEVENTs. */ 2208 if (sig == SIGKILL) { 2209 /* from procfs_ioctl.c: PIOCBIC */ 2210 p->p_stops = 0; 2211 /* from procfs_ioctl.c: PIOCCONT */ 2212 p->p_step = 0; 2213 wakeup(&p->p_step); 2214 } 2215 /* 2216 * Some signals have a process-wide effect and a per-thread 2217 * component. Most processing occurs when the process next 2218 * tries to cross the user boundary, however there are some 2219 * times when processing needs to be done immediately, such as 2220 * waking up threads so that they can cross the user boundary. 2221 * We try to do the per-process part here. 2222 */ 2223 if (P_SHOULDSTOP(p)) { 2224 KASSERT(!(p->p_flag & P_WEXIT), 2225 ("signal to stopped but exiting process")); 2226 if (sig == SIGKILL) { 2227 /* 2228 * If traced process is already stopped, 2229 * then no further action is necessary. 2230 */ 2231 if (p->p_flag & P_TRACED) 2232 goto out; 2233 /* 2234 * SIGKILL sets process running. 2235 * It will die elsewhere. 2236 * All threads must be restarted. 2237 */ 2238 p->p_flag &= ~P_STOPPED_SIG; 2239 goto runfast; 2240 } 2241 2242 if (prop & SIGPROP_CONT) { 2243 /* 2244 * If traced process is already stopped, 2245 * then no further action is necessary. 2246 */ 2247 if (p->p_flag & P_TRACED) 2248 goto out; 2249 /* 2250 * If SIGCONT is default (or ignored), we continue the 2251 * process but don't leave the signal in sigqueue as 2252 * it has no further action. If SIGCONT is held, we 2253 * continue the process and leave the signal in 2254 * sigqueue. If the process catches SIGCONT, let it 2255 * handle the signal itself. If it isn't waiting on 2256 * an event, it goes back to run state. 2257 * Otherwise, process goes back to sleep state. 2258 */ 2259 p->p_flag &= ~P_STOPPED_SIG; 2260 PROC_SLOCK(p); 2261 if (p->p_numthreads == p->p_suspcount) { 2262 PROC_SUNLOCK(p); 2263 p->p_flag |= P_CONTINUED; 2264 p->p_xsig = SIGCONT; 2265 PROC_LOCK(p->p_pptr); 2266 childproc_continued(p); 2267 PROC_UNLOCK(p->p_pptr); 2268 PROC_SLOCK(p); 2269 } 2270 if (action == SIG_DFL) { 2271 thread_unsuspend(p); 2272 PROC_SUNLOCK(p); 2273 sigqueue_delete(sigqueue, sig); 2274 goto out; 2275 } 2276 if (action == SIG_CATCH) { 2277 /* 2278 * The process wants to catch it so it needs 2279 * to run at least one thread, but which one? 2280 */ 2281 PROC_SUNLOCK(p); 2282 goto runfast; 2283 } 2284 /* 2285 * The signal is not ignored or caught. 2286 */ 2287 thread_unsuspend(p); 2288 PROC_SUNLOCK(p); 2289 goto out; 2290 } 2291 2292 if (prop & SIGPROP_STOP) { 2293 /* 2294 * If traced process is already stopped, 2295 * then no further action is necessary. 2296 */ 2297 if (p->p_flag & P_TRACED) 2298 goto out; 2299 /* 2300 * Already stopped, don't need to stop again 2301 * (If we did the shell could get confused). 2302 * Just make sure the signal STOP bit set. 2303 */ 2304 p->p_flag |= P_STOPPED_SIG; 2305 sigqueue_delete(sigqueue, sig); 2306 goto out; 2307 } 2308 2309 /* 2310 * All other kinds of signals: 2311 * If a thread is sleeping interruptibly, simulate a 2312 * wakeup so that when it is continued it will be made 2313 * runnable and can look at the signal. However, don't make 2314 * the PROCESS runnable, leave it stopped. 2315 * It may run a bit until it hits a thread_suspend_check(). 2316 */ 2317 wakeup_swapper = 0; 2318 PROC_SLOCK(p); 2319 thread_lock(td); 2320 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2321 wakeup_swapper = sleepq_abort(td, intrval); 2322 thread_unlock(td); 2323 PROC_SUNLOCK(p); 2324 if (wakeup_swapper) 2325 kick_proc0(); 2326 goto out; 2327 /* 2328 * Mutexes are short lived. Threads waiting on them will 2329 * hit thread_suspend_check() soon. 2330 */ 2331 } else if (p->p_state == PRS_NORMAL) { 2332 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2333 tdsigwakeup(td, sig, action, intrval); 2334 goto out; 2335 } 2336 2337 MPASS(action == SIG_DFL); 2338 2339 if (prop & SIGPROP_STOP) { 2340 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2341 goto out; 2342 p->p_flag |= P_STOPPED_SIG; 2343 p->p_xsig = sig; 2344 PROC_SLOCK(p); 2345 wakeup_swapper = sig_suspend_threads(td, p, 1); 2346 if (p->p_numthreads == p->p_suspcount) { 2347 /* 2348 * only thread sending signal to another 2349 * process can reach here, if thread is sending 2350 * signal to its process, because thread does 2351 * not suspend itself here, p_numthreads 2352 * should never be equal to p_suspcount. 2353 */ 2354 thread_stopped(p); 2355 PROC_SUNLOCK(p); 2356 sigqueue_delete_proc(p, p->p_xsig); 2357 } else 2358 PROC_SUNLOCK(p); 2359 if (wakeup_swapper) 2360 kick_proc0(); 2361 goto out; 2362 } 2363 } else { 2364 /* Not in "NORMAL" state. discard the signal. */ 2365 sigqueue_delete(sigqueue, sig); 2366 goto out; 2367 } 2368 2369 /* 2370 * The process is not stopped so we need to apply the signal to all the 2371 * running threads. 2372 */ 2373 runfast: 2374 tdsigwakeup(td, sig, action, intrval); 2375 PROC_SLOCK(p); 2376 thread_unsuspend(p); 2377 PROC_SUNLOCK(p); 2378 out: 2379 /* If we jump here, proc slock should not be owned. */ 2380 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2381 return (ret); 2382 } 2383 2384 /* 2385 * The force of a signal has been directed against a single 2386 * thread. We need to see what we can do about knocking it 2387 * out of any sleep it may be in etc. 2388 */ 2389 static void 2390 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2391 { 2392 struct proc *p = td->td_proc; 2393 int prop; 2394 int wakeup_swapper; 2395 2396 wakeup_swapper = 0; 2397 PROC_LOCK_ASSERT(p, MA_OWNED); 2398 prop = sigprop(sig); 2399 2400 PROC_SLOCK(p); 2401 thread_lock(td); 2402 /* 2403 * Bring the priority of a thread up if we want it to get 2404 * killed in this lifetime. Be careful to avoid bumping the 2405 * priority of the idle thread, since we still allow to signal 2406 * kernel processes. 2407 */ 2408 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2409 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2410 sched_prio(td, PUSER); 2411 if (TD_ON_SLEEPQ(td)) { 2412 /* 2413 * If thread is sleeping uninterruptibly 2414 * we can't interrupt the sleep... the signal will 2415 * be noticed when the process returns through 2416 * trap() or syscall(). 2417 */ 2418 if ((td->td_flags & TDF_SINTR) == 0) 2419 goto out; 2420 /* 2421 * If SIGCONT is default (or ignored) and process is 2422 * asleep, we are finished; the process should not 2423 * be awakened. 2424 */ 2425 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2426 thread_unlock(td); 2427 PROC_SUNLOCK(p); 2428 sigqueue_delete(&p->p_sigqueue, sig); 2429 /* 2430 * It may be on either list in this state. 2431 * Remove from both for now. 2432 */ 2433 sigqueue_delete(&td->td_sigqueue, sig); 2434 return; 2435 } 2436 2437 /* 2438 * Don't awaken a sleeping thread for SIGSTOP if the 2439 * STOP signal is deferred. 2440 */ 2441 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2442 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2443 goto out; 2444 2445 /* 2446 * Give low priority threads a better chance to run. 2447 */ 2448 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2449 sched_prio(td, PUSER); 2450 2451 wakeup_swapper = sleepq_abort(td, intrval); 2452 } else { 2453 /* 2454 * Other states do nothing with the signal immediately, 2455 * other than kicking ourselves if we are running. 2456 * It will either never be noticed, or noticed very soon. 2457 */ 2458 #ifdef SMP 2459 if (TD_IS_RUNNING(td) && td != curthread) 2460 forward_signal(td); 2461 #endif 2462 } 2463 out: 2464 PROC_SUNLOCK(p); 2465 thread_unlock(td); 2466 if (wakeup_swapper) 2467 kick_proc0(); 2468 } 2469 2470 static int 2471 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2472 { 2473 struct thread *td2; 2474 int wakeup_swapper; 2475 2476 PROC_LOCK_ASSERT(p, MA_OWNED); 2477 PROC_SLOCK_ASSERT(p, MA_OWNED); 2478 MPASS(sending || td == curthread); 2479 2480 wakeup_swapper = 0; 2481 FOREACH_THREAD_IN_PROC(p, td2) { 2482 thread_lock(td2); 2483 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2484 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2485 (td2->td_flags & TDF_SINTR)) { 2486 if (td2->td_flags & TDF_SBDRY) { 2487 /* 2488 * Once a thread is asleep with 2489 * TDF_SBDRY and without TDF_SERESTART 2490 * or TDF_SEINTR set, it should never 2491 * become suspended due to this check. 2492 */ 2493 KASSERT(!TD_IS_SUSPENDED(td2), 2494 ("thread with deferred stops suspended")); 2495 if (TD_SBDRY_INTR(td2)) 2496 wakeup_swapper |= sleepq_abort(td2, 2497 TD_SBDRY_ERRNO(td2)); 2498 } else if (!TD_IS_SUSPENDED(td2)) { 2499 thread_suspend_one(td2); 2500 } 2501 } else if (!TD_IS_SUSPENDED(td2)) { 2502 if (sending || td != td2) 2503 td2->td_flags |= TDF_ASTPENDING; 2504 #ifdef SMP 2505 if (TD_IS_RUNNING(td2) && td2 != td) 2506 forward_signal(td2); 2507 #endif 2508 } 2509 thread_unlock(td2); 2510 } 2511 return (wakeup_swapper); 2512 } 2513 2514 /* 2515 * Stop the process for an event deemed interesting to the debugger. If si is 2516 * non-NULL, this is a signal exchange; the new signal requested by the 2517 * debugger will be returned for handling. If si is NULL, this is some other 2518 * type of interesting event. The debugger may request a signal be delivered in 2519 * that case as well, however it will be deferred until it can be handled. 2520 */ 2521 int 2522 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2523 { 2524 struct proc *p = td->td_proc; 2525 struct thread *td2; 2526 ksiginfo_t ksi; 2527 int prop; 2528 2529 PROC_LOCK_ASSERT(p, MA_OWNED); 2530 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2531 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2532 &p->p_mtx.lock_object, "Stopping for traced signal"); 2533 2534 td->td_xsig = sig; 2535 2536 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2537 td->td_dbgflags |= TDB_XSIG; 2538 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2539 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2540 PROC_SLOCK(p); 2541 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2542 if (P_KILLED(p)) { 2543 /* 2544 * Ensure that, if we've been PT_KILLed, the 2545 * exit status reflects that. Another thread 2546 * may also be in ptracestop(), having just 2547 * received the SIGKILL, but this thread was 2548 * unsuspended first. 2549 */ 2550 td->td_dbgflags &= ~TDB_XSIG; 2551 td->td_xsig = SIGKILL; 2552 p->p_ptevents = 0; 2553 break; 2554 } 2555 if (p->p_flag & P_SINGLE_EXIT && 2556 !(td->td_dbgflags & TDB_EXIT)) { 2557 /* 2558 * Ignore ptrace stops except for thread exit 2559 * events when the process exits. 2560 */ 2561 td->td_dbgflags &= ~TDB_XSIG; 2562 PROC_SUNLOCK(p); 2563 return (0); 2564 } 2565 2566 /* 2567 * Make wait(2) work. Ensure that right after the 2568 * attach, the thread which was decided to become the 2569 * leader of attach gets reported to the waiter. 2570 * Otherwise, just avoid overwriting another thread's 2571 * assignment to p_xthread. If another thread has 2572 * already set p_xthread, the current thread will get 2573 * a chance to report itself upon the next iteration. 2574 */ 2575 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2576 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2577 p->p_xthread == NULL)) { 2578 p->p_xsig = sig; 2579 p->p_xthread = td; 2580 2581 /* 2582 * If we are on sleepqueue already, 2583 * let sleepqueue code decide if it 2584 * needs to go sleep after attach. 2585 */ 2586 if (td->td_wchan == NULL) 2587 td->td_dbgflags &= ~TDB_FSTP; 2588 2589 p->p_flag2 &= ~P2_PTRACE_FSTP; 2590 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2591 sig_suspend_threads(td, p, 0); 2592 } 2593 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2594 td->td_dbgflags &= ~TDB_STOPATFORK; 2595 } 2596 stopme: 2597 thread_suspend_switch(td, p); 2598 if (p->p_xthread == td) 2599 p->p_xthread = NULL; 2600 if (!(p->p_flag & P_TRACED)) 2601 break; 2602 if (td->td_dbgflags & TDB_SUSPEND) { 2603 if (p->p_flag & P_SINGLE_EXIT) 2604 break; 2605 goto stopme; 2606 } 2607 } 2608 PROC_SUNLOCK(p); 2609 } 2610 2611 if (si != NULL && sig == td->td_xsig) { 2612 /* Parent wants us to take the original signal unchanged. */ 2613 si->ksi_flags |= KSI_HEAD; 2614 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2615 si->ksi_signo = 0; 2616 } else if (td->td_xsig != 0) { 2617 /* 2618 * If parent wants us to take a new signal, then it will leave 2619 * it in td->td_xsig; otherwise we just look for signals again. 2620 */ 2621 ksiginfo_init(&ksi); 2622 ksi.ksi_signo = td->td_xsig; 2623 ksi.ksi_flags |= KSI_PTRACE; 2624 prop = sigprop(td->td_xsig); 2625 td2 = sigtd(p, td->td_xsig, prop); 2626 tdsendsignal(p, td2, td->td_xsig, &ksi); 2627 if (td != td2) 2628 return (0); 2629 } 2630 2631 return (td->td_xsig); 2632 } 2633 2634 static void 2635 reschedule_signals(struct proc *p, sigset_t block, int flags) 2636 { 2637 struct sigacts *ps; 2638 struct thread *td; 2639 int sig; 2640 2641 PROC_LOCK_ASSERT(p, MA_OWNED); 2642 ps = p->p_sigacts; 2643 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2644 MA_OWNED : MA_NOTOWNED); 2645 if (SIGISEMPTY(p->p_siglist)) 2646 return; 2647 SIGSETAND(block, p->p_siglist); 2648 while ((sig = sig_ffs(&block)) != 0) { 2649 SIGDELSET(block, sig); 2650 td = sigtd(p, sig, 0); 2651 signotify(td); 2652 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2653 mtx_lock(&ps->ps_mtx); 2654 if (p->p_flag & P_TRACED || 2655 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2656 !SIGISMEMBER(td->td_sigmask, sig))) 2657 tdsigwakeup(td, sig, SIG_CATCH, 2658 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2659 ERESTART)); 2660 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2661 mtx_unlock(&ps->ps_mtx); 2662 } 2663 } 2664 2665 void 2666 tdsigcleanup(struct thread *td) 2667 { 2668 struct proc *p; 2669 sigset_t unblocked; 2670 2671 p = td->td_proc; 2672 PROC_LOCK_ASSERT(p, MA_OWNED); 2673 2674 sigqueue_flush(&td->td_sigqueue); 2675 if (p->p_numthreads == 1) 2676 return; 2677 2678 /* 2679 * Since we cannot handle signals, notify signal post code 2680 * about this by filling the sigmask. 2681 * 2682 * Also, if needed, wake up thread(s) that do not block the 2683 * same signals as the exiting thread, since the thread might 2684 * have been selected for delivery and woken up. 2685 */ 2686 SIGFILLSET(unblocked); 2687 SIGSETNAND(unblocked, td->td_sigmask); 2688 SIGFILLSET(td->td_sigmask); 2689 reschedule_signals(p, unblocked, 0); 2690 2691 } 2692 2693 static int 2694 sigdeferstop_curr_flags(int cflags) 2695 { 2696 2697 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2698 (cflags & TDF_SBDRY) != 0); 2699 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2700 } 2701 2702 /* 2703 * Defer the delivery of SIGSTOP for the current thread, according to 2704 * the requested mode. Returns previous flags, which must be restored 2705 * by sigallowstop(). 2706 * 2707 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2708 * cleared by the current thread, which allow the lock-less read-only 2709 * accesses below. 2710 */ 2711 int 2712 sigdeferstop_impl(int mode) 2713 { 2714 struct thread *td; 2715 int cflags, nflags; 2716 2717 td = curthread; 2718 cflags = sigdeferstop_curr_flags(td->td_flags); 2719 switch (mode) { 2720 case SIGDEFERSTOP_NOP: 2721 nflags = cflags; 2722 break; 2723 case SIGDEFERSTOP_OFF: 2724 nflags = 0; 2725 break; 2726 case SIGDEFERSTOP_SILENT: 2727 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2728 break; 2729 case SIGDEFERSTOP_EINTR: 2730 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2731 break; 2732 case SIGDEFERSTOP_ERESTART: 2733 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2734 break; 2735 default: 2736 panic("sigdeferstop: invalid mode %x", mode); 2737 break; 2738 } 2739 if (cflags == nflags) 2740 return (SIGDEFERSTOP_VAL_NCHG); 2741 thread_lock(td); 2742 td->td_flags = (td->td_flags & ~cflags) | nflags; 2743 thread_unlock(td); 2744 return (cflags); 2745 } 2746 2747 /* 2748 * Restores the STOP handling mode, typically permitting the delivery 2749 * of SIGSTOP for the current thread. This does not immediately 2750 * suspend if a stop was posted. Instead, the thread will suspend 2751 * either via ast() or a subsequent interruptible sleep. 2752 */ 2753 void 2754 sigallowstop_impl(int prev) 2755 { 2756 struct thread *td; 2757 int cflags; 2758 2759 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2760 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2761 ("sigallowstop: incorrect previous mode %x", prev)); 2762 td = curthread; 2763 cflags = sigdeferstop_curr_flags(td->td_flags); 2764 if (cflags != prev) { 2765 thread_lock(td); 2766 td->td_flags = (td->td_flags & ~cflags) | prev; 2767 thread_unlock(td); 2768 } 2769 } 2770 2771 /* 2772 * If the current process has received a signal (should be caught or cause 2773 * termination, should interrupt current syscall), return the signal number. 2774 * Stop signals with default action are processed immediately, then cleared; 2775 * they aren't returned. This is checked after each entry to the system for 2776 * a syscall or trap (though this can usually be done without calling issignal 2777 * by checking the pending signal masks in cursig.) The normal call 2778 * sequence is 2779 * 2780 * while (sig = cursig(curthread)) 2781 * postsig(sig); 2782 */ 2783 static int 2784 issignal(struct thread *td) 2785 { 2786 struct proc *p; 2787 struct sigacts *ps; 2788 struct sigqueue *queue; 2789 sigset_t sigpending; 2790 ksiginfo_t ksi; 2791 int prop, sig, traced; 2792 2793 p = td->td_proc; 2794 ps = p->p_sigacts; 2795 mtx_assert(&ps->ps_mtx, MA_OWNED); 2796 PROC_LOCK_ASSERT(p, MA_OWNED); 2797 for (;;) { 2798 traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2799 2800 sigpending = td->td_sigqueue.sq_signals; 2801 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2802 SIGSETNAND(sigpending, td->td_sigmask); 2803 2804 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2805 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2806 SIG_STOPSIGMASK(sigpending); 2807 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2808 return (0); 2809 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2810 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2811 SIGISMEMBER(sigpending, SIGSTOP)) { 2812 /* 2813 * If debugger just attached, always consume 2814 * SIGSTOP from ptrace(PT_ATTACH) first, to 2815 * execute the debugger attach ritual in 2816 * order. 2817 */ 2818 sig = SIGSTOP; 2819 td->td_dbgflags |= TDB_FSTP; 2820 } else { 2821 sig = sig_ffs(&sigpending); 2822 } 2823 2824 if (p->p_stops & S_SIG) { 2825 mtx_unlock(&ps->ps_mtx); 2826 stopevent(p, S_SIG, sig); 2827 mtx_lock(&ps->ps_mtx); 2828 } 2829 2830 /* 2831 * We should see pending but ignored signals 2832 * only if P_TRACED was on when they were posted. 2833 */ 2834 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2835 sigqueue_delete(&td->td_sigqueue, sig); 2836 sigqueue_delete(&p->p_sigqueue, sig); 2837 continue; 2838 } 2839 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2840 /* 2841 * If traced, always stop. 2842 * Remove old signal from queue before the stop. 2843 * XXX shrug off debugger, it causes siginfo to 2844 * be thrown away. 2845 */ 2846 queue = &td->td_sigqueue; 2847 ksiginfo_init(&ksi); 2848 if (sigqueue_get(queue, sig, &ksi) == 0) { 2849 queue = &p->p_sigqueue; 2850 sigqueue_get(queue, sig, &ksi); 2851 } 2852 td->td_si = ksi.ksi_info; 2853 2854 mtx_unlock(&ps->ps_mtx); 2855 sig = ptracestop(td, sig, &ksi); 2856 mtx_lock(&ps->ps_mtx); 2857 2858 td->td_si.si_signo = 0; 2859 2860 /* 2861 * Keep looking if the debugger discarded or 2862 * replaced the signal. 2863 */ 2864 if (sig == 0) 2865 continue; 2866 2867 /* 2868 * If the signal became masked, re-queue it. 2869 */ 2870 if (SIGISMEMBER(td->td_sigmask, sig)) { 2871 ksi.ksi_flags |= KSI_HEAD; 2872 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2873 continue; 2874 } 2875 2876 /* 2877 * If the traced bit got turned off, requeue 2878 * the signal and go back up to the top to 2879 * rescan signals. This ensures that p_sig* 2880 * and p_sigact are consistent. 2881 */ 2882 if ((p->p_flag & P_TRACED) == 0) { 2883 ksi.ksi_flags |= KSI_HEAD; 2884 sigqueue_add(queue, sig, &ksi); 2885 continue; 2886 } 2887 } 2888 2889 prop = sigprop(sig); 2890 2891 /* 2892 * Decide whether the signal should be returned. 2893 * Return the signal's number, or fall through 2894 * to clear it from the pending mask. 2895 */ 2896 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2897 2898 case (intptr_t)SIG_DFL: 2899 /* 2900 * Don't take default actions on system processes. 2901 */ 2902 if (p->p_pid <= 1) { 2903 #ifdef DIAGNOSTIC 2904 /* 2905 * Are you sure you want to ignore SIGSEGV 2906 * in init? XXX 2907 */ 2908 printf("Process (pid %lu) got signal %d\n", 2909 (u_long)p->p_pid, sig); 2910 #endif 2911 break; /* == ignore */ 2912 } 2913 /* 2914 * If there is a pending stop signal to process with 2915 * default action, stop here, then clear the signal. 2916 * Traced or exiting processes should ignore stops. 2917 * Additionally, a member of an orphaned process group 2918 * should ignore tty stops. 2919 */ 2920 if (prop & SIGPROP_STOP) { 2921 if (p->p_flag & 2922 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 2923 (p->p_pgrp->pg_jobc == 0 && 2924 prop & SIGPROP_TTYSTOP)) 2925 break; /* == ignore */ 2926 if (TD_SBDRY_INTR(td)) { 2927 KASSERT((td->td_flags & TDF_SBDRY) != 0, 2928 ("lost TDF_SBDRY")); 2929 return (-1); 2930 } 2931 mtx_unlock(&ps->ps_mtx); 2932 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2933 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2934 sigqueue_delete(&td->td_sigqueue, sig); 2935 sigqueue_delete(&p->p_sigqueue, sig); 2936 p->p_flag |= P_STOPPED_SIG; 2937 p->p_xsig = sig; 2938 PROC_SLOCK(p); 2939 sig_suspend_threads(td, p, 0); 2940 thread_suspend_switch(td, p); 2941 PROC_SUNLOCK(p); 2942 mtx_lock(&ps->ps_mtx); 2943 goto next; 2944 } else if (prop & SIGPROP_IGNORE) { 2945 /* 2946 * Except for SIGCONT, shouldn't get here. 2947 * Default action is to ignore; drop it. 2948 */ 2949 break; /* == ignore */ 2950 } else 2951 return (sig); 2952 /*NOTREACHED*/ 2953 2954 case (intptr_t)SIG_IGN: 2955 /* 2956 * Masking above should prevent us ever trying 2957 * to take action on an ignored signal other 2958 * than SIGCONT, unless process is traced. 2959 */ 2960 if ((prop & SIGPROP_CONT) == 0 && 2961 (p->p_flag & P_TRACED) == 0) 2962 printf("issignal\n"); 2963 break; /* == ignore */ 2964 2965 default: 2966 /* 2967 * This signal has an action, let 2968 * postsig() process it. 2969 */ 2970 return (sig); 2971 } 2972 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2973 sigqueue_delete(&p->p_sigqueue, sig); 2974 next:; 2975 } 2976 /* NOTREACHED */ 2977 } 2978 2979 void 2980 thread_stopped(struct proc *p) 2981 { 2982 int n; 2983 2984 PROC_LOCK_ASSERT(p, MA_OWNED); 2985 PROC_SLOCK_ASSERT(p, MA_OWNED); 2986 n = p->p_suspcount; 2987 if (p == curproc) 2988 n++; 2989 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2990 PROC_SUNLOCK(p); 2991 p->p_flag &= ~P_WAITED; 2992 PROC_LOCK(p->p_pptr); 2993 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2994 CLD_TRAPPED : CLD_STOPPED); 2995 PROC_UNLOCK(p->p_pptr); 2996 PROC_SLOCK(p); 2997 } 2998 } 2999 3000 /* 3001 * Take the action for the specified signal 3002 * from the current set of pending signals. 3003 */ 3004 int 3005 postsig(int sig) 3006 { 3007 struct thread *td; 3008 struct proc *p; 3009 struct sigacts *ps; 3010 sig_t action; 3011 ksiginfo_t ksi; 3012 sigset_t returnmask; 3013 3014 KASSERT(sig != 0, ("postsig")); 3015 3016 td = curthread; 3017 p = td->td_proc; 3018 PROC_LOCK_ASSERT(p, MA_OWNED); 3019 ps = p->p_sigacts; 3020 mtx_assert(&ps->ps_mtx, MA_OWNED); 3021 ksiginfo_init(&ksi); 3022 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3023 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3024 return (0); 3025 ksi.ksi_signo = sig; 3026 if (ksi.ksi_code == SI_TIMER) 3027 itimer_accept(p, ksi.ksi_timerid, &ksi); 3028 action = ps->ps_sigact[_SIG_IDX(sig)]; 3029 #ifdef KTRACE 3030 if (KTRPOINT(td, KTR_PSIG)) 3031 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3032 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3033 #endif 3034 if ((p->p_stops & S_SIG) != 0) { 3035 mtx_unlock(&ps->ps_mtx); 3036 stopevent(p, S_SIG, sig); 3037 mtx_lock(&ps->ps_mtx); 3038 } 3039 3040 if (action == SIG_DFL) { 3041 /* 3042 * Default action, where the default is to kill 3043 * the process. (Other cases were ignored above.) 3044 */ 3045 mtx_unlock(&ps->ps_mtx); 3046 proc_td_siginfo_capture(td, &ksi.ksi_info); 3047 sigexit(td, sig); 3048 /* NOTREACHED */ 3049 } else { 3050 /* 3051 * If we get here, the signal must be caught. 3052 */ 3053 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3054 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3055 ("postsig action: blocked sig %d", sig)); 3056 3057 /* 3058 * Set the new mask value and also defer further 3059 * occurrences of this signal. 3060 * 3061 * Special case: user has done a sigsuspend. Here the 3062 * current mask is not of interest, but rather the 3063 * mask from before the sigsuspend is what we want 3064 * restored after the signal processing is completed. 3065 */ 3066 if (td->td_pflags & TDP_OLDMASK) { 3067 returnmask = td->td_oldsigmask; 3068 td->td_pflags &= ~TDP_OLDMASK; 3069 } else 3070 returnmask = td->td_sigmask; 3071 3072 if (p->p_sig == sig) { 3073 p->p_sig = 0; 3074 } 3075 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3076 postsig_done(sig, td, ps); 3077 } 3078 return (1); 3079 } 3080 3081 void 3082 proc_wkilled(struct proc *p) 3083 { 3084 3085 PROC_LOCK_ASSERT(p, MA_OWNED); 3086 if ((p->p_flag & P_WKILLED) == 0) { 3087 p->p_flag |= P_WKILLED; 3088 /* 3089 * Notify swapper that there is a process to swap in. 3090 * The notification is racy, at worst it would take 10 3091 * seconds for the swapper process to notice. 3092 */ 3093 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3094 wakeup(&proc0); 3095 } 3096 } 3097 3098 /* 3099 * Kill the current process for stated reason. 3100 */ 3101 void 3102 killproc(struct proc *p, char *why) 3103 { 3104 3105 PROC_LOCK_ASSERT(p, MA_OWNED); 3106 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3107 p->p_comm); 3108 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3109 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3110 p->p_ucred->cr_uid, why); 3111 proc_wkilled(p); 3112 kern_psignal(p, SIGKILL); 3113 } 3114 3115 /* 3116 * Force the current process to exit with the specified signal, dumping core 3117 * if appropriate. We bypass the normal tests for masked and caught signals, 3118 * allowing unrecoverable failures to terminate the process without changing 3119 * signal state. Mark the accounting record with the signal termination. 3120 * If dumping core, save the signal number for the debugger. Calls exit and 3121 * does not return. 3122 */ 3123 void 3124 sigexit(struct thread *td, int sig) 3125 { 3126 struct proc *p = td->td_proc; 3127 3128 PROC_LOCK_ASSERT(p, MA_OWNED); 3129 p->p_acflag |= AXSIG; 3130 /* 3131 * We must be single-threading to generate a core dump. This 3132 * ensures that the registers in the core file are up-to-date. 3133 * Also, the ELF dump handler assumes that the thread list doesn't 3134 * change out from under it. 3135 * 3136 * XXX If another thread attempts to single-thread before us 3137 * (e.g. via fork()), we won't get a dump at all. 3138 */ 3139 if ((sigprop(sig) & SIGPROP_CORE) && 3140 thread_single(p, SINGLE_NO_EXIT) == 0) { 3141 p->p_sig = sig; 3142 /* 3143 * Log signals which would cause core dumps 3144 * (Log as LOG_INFO to appease those who don't want 3145 * these messages.) 3146 * XXX : Todo, as well as euid, write out ruid too 3147 * Note that coredump() drops proc lock. 3148 */ 3149 if (coredump(td) == 0) 3150 sig |= WCOREFLAG; 3151 if (kern_logsigexit) 3152 log(LOG_INFO, 3153 "pid %d (%s), jid %d, uid %d: exited on " 3154 "signal %d%s\n", p->p_pid, p->p_comm, 3155 p->p_ucred->cr_prison->pr_id, 3156 td->td_ucred->cr_uid, 3157 sig &~ WCOREFLAG, 3158 sig & WCOREFLAG ? " (core dumped)" : ""); 3159 } else 3160 PROC_UNLOCK(p); 3161 exit1(td, 0, sig); 3162 /* NOTREACHED */ 3163 } 3164 3165 /* 3166 * Send queued SIGCHLD to parent when child process's state 3167 * is changed. 3168 */ 3169 static void 3170 sigparent(struct proc *p, int reason, int status) 3171 { 3172 PROC_LOCK_ASSERT(p, MA_OWNED); 3173 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3174 3175 if (p->p_ksi != NULL) { 3176 p->p_ksi->ksi_signo = SIGCHLD; 3177 p->p_ksi->ksi_code = reason; 3178 p->p_ksi->ksi_status = status; 3179 p->p_ksi->ksi_pid = p->p_pid; 3180 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3181 if (KSI_ONQ(p->p_ksi)) 3182 return; 3183 } 3184 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3185 } 3186 3187 static void 3188 childproc_jobstate(struct proc *p, int reason, int sig) 3189 { 3190 struct sigacts *ps; 3191 3192 PROC_LOCK_ASSERT(p, MA_OWNED); 3193 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3194 3195 /* 3196 * Wake up parent sleeping in kern_wait(), also send 3197 * SIGCHLD to parent, but SIGCHLD does not guarantee 3198 * that parent will awake, because parent may masked 3199 * the signal. 3200 */ 3201 p->p_pptr->p_flag |= P_STATCHILD; 3202 wakeup(p->p_pptr); 3203 3204 ps = p->p_pptr->p_sigacts; 3205 mtx_lock(&ps->ps_mtx); 3206 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3207 mtx_unlock(&ps->ps_mtx); 3208 sigparent(p, reason, sig); 3209 } else 3210 mtx_unlock(&ps->ps_mtx); 3211 } 3212 3213 void 3214 childproc_stopped(struct proc *p, int reason) 3215 { 3216 3217 childproc_jobstate(p, reason, p->p_xsig); 3218 } 3219 3220 void 3221 childproc_continued(struct proc *p) 3222 { 3223 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3224 } 3225 3226 void 3227 childproc_exited(struct proc *p) 3228 { 3229 int reason, status; 3230 3231 if (WCOREDUMP(p->p_xsig)) { 3232 reason = CLD_DUMPED; 3233 status = WTERMSIG(p->p_xsig); 3234 } else if (WIFSIGNALED(p->p_xsig)) { 3235 reason = CLD_KILLED; 3236 status = WTERMSIG(p->p_xsig); 3237 } else { 3238 reason = CLD_EXITED; 3239 status = p->p_xexit; 3240 } 3241 /* 3242 * XXX avoid calling wakeup(p->p_pptr), the work is 3243 * done in exit1(). 3244 */ 3245 sigparent(p, reason, status); 3246 } 3247 3248 #define MAX_NUM_CORE_FILES 100000 3249 #ifndef NUM_CORE_FILES 3250 #define NUM_CORE_FILES 5 3251 #endif 3252 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3253 static int num_cores = NUM_CORE_FILES; 3254 3255 static int 3256 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3257 { 3258 int error; 3259 int new_val; 3260 3261 new_val = num_cores; 3262 error = sysctl_handle_int(oidp, &new_val, 0, req); 3263 if (error != 0 || req->newptr == NULL) 3264 return (error); 3265 if (new_val > MAX_NUM_CORE_FILES) 3266 new_val = MAX_NUM_CORE_FILES; 3267 if (new_val < 0) 3268 new_val = 0; 3269 num_cores = new_val; 3270 return (0); 3271 } 3272 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3273 0, sizeof(int), sysctl_debug_num_cores_check, "I", 3274 "Maximum number of generated process corefiles while using index format"); 3275 3276 #define GZIP_SUFFIX ".gz" 3277 #define ZSTD_SUFFIX ".zst" 3278 3279 int compress_user_cores = 0; 3280 3281 static int 3282 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3283 { 3284 int error, val; 3285 3286 val = compress_user_cores; 3287 error = sysctl_handle_int(oidp, &val, 0, req); 3288 if (error != 0 || req->newptr == NULL) 3289 return (error); 3290 if (val != 0 && !compressor_avail(val)) 3291 return (EINVAL); 3292 compress_user_cores = val; 3293 return (error); 3294 } 3295 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, CTLTYPE_INT | CTLFLAG_RWTUN, 3296 0, sizeof(int), sysctl_compress_user_cores, "I", 3297 "Enable compression of user corefiles (" 3298 __XSTRING(COMPRESS_GZIP) " = gzip, " 3299 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3300 3301 int compress_user_cores_level = 6; 3302 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3303 &compress_user_cores_level, 0, 3304 "Corefile compression level"); 3305 3306 /* 3307 * Protect the access to corefilename[] by allproc_lock. 3308 */ 3309 #define corefilename_lock allproc_lock 3310 3311 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3312 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3313 3314 static int 3315 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3316 { 3317 int error; 3318 3319 sx_xlock(&corefilename_lock); 3320 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3321 req); 3322 sx_xunlock(&corefilename_lock); 3323 3324 return (error); 3325 } 3326 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3327 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3328 "Process corefile name format string"); 3329 3330 static void 3331 vnode_close_locked(struct thread *td, struct vnode *vp) 3332 { 3333 3334 VOP_UNLOCK(vp, 0); 3335 vn_close(vp, FWRITE, td->td_ucred, td); 3336 } 3337 3338 /* 3339 * If the core format has a %I in it, then we need to check 3340 * for existing corefiles before defining a name. 3341 * To do this we iterate over 0..ncores to find a 3342 * non-existing core file name to use. If all core files are 3343 * already used we choose the oldest one. 3344 */ 3345 static int 3346 corefile_open_last(struct thread *td, char *name, int indexpos, 3347 int indexlen, int ncores, struct vnode **vpp) 3348 { 3349 struct vnode *oldvp, *nextvp, *vp; 3350 struct vattr vattr; 3351 struct nameidata nd; 3352 int error, i, flags, oflags, cmode; 3353 char ch; 3354 struct timespec lasttime; 3355 3356 nextvp = oldvp = NULL; 3357 cmode = S_IRUSR | S_IWUSR; 3358 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3359 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3360 3361 for (i = 0; i < ncores; i++) { 3362 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3363 3364 ch = name[indexpos + indexlen]; 3365 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3366 i); 3367 name[indexpos + indexlen] = ch; 3368 3369 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3370 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3371 NULL); 3372 if (error != 0) 3373 break; 3374 3375 vp = nd.ni_vp; 3376 NDFREE(&nd, NDF_ONLY_PNBUF); 3377 if ((flags & O_CREAT) == O_CREAT) { 3378 nextvp = vp; 3379 break; 3380 } 3381 3382 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3383 if (error != 0) { 3384 vnode_close_locked(td, vp); 3385 break; 3386 } 3387 3388 if (oldvp == NULL || 3389 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3390 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3391 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3392 if (oldvp != NULL) 3393 vnode_close_locked(td, oldvp); 3394 oldvp = vp; 3395 lasttime = vattr.va_mtime; 3396 } else { 3397 vnode_close_locked(td, vp); 3398 } 3399 } 3400 3401 if (oldvp != NULL) { 3402 if (nextvp == NULL) { 3403 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3404 error = EFAULT; 3405 vnode_close_locked(td, oldvp); 3406 } else { 3407 nextvp = oldvp; 3408 } 3409 } else { 3410 vnode_close_locked(td, oldvp); 3411 } 3412 } 3413 if (error != 0) { 3414 if (nextvp != NULL) 3415 vnode_close_locked(td, oldvp); 3416 } else { 3417 *vpp = nextvp; 3418 } 3419 3420 return (error); 3421 } 3422 3423 /* 3424 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3425 * Expand the name described in corefilename, using name, uid, and pid 3426 * and open/create core file. 3427 * corefilename is a printf-like string, with three format specifiers: 3428 * %N name of process ("name") 3429 * %P process id (pid) 3430 * %U user id (uid) 3431 * For example, "%N.core" is the default; they can be disabled completely 3432 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3433 * This is controlled by the sysctl variable kern.corefile (see above). 3434 */ 3435 static int 3436 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3437 int compress, int signum, struct vnode **vpp, char **namep) 3438 { 3439 struct sbuf sb; 3440 struct nameidata nd; 3441 const char *format; 3442 char *hostname, *name; 3443 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3444 3445 hostname = NULL; 3446 format = corefilename; 3447 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3448 indexlen = 0; 3449 indexpos = -1; 3450 ncores = num_cores; 3451 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3452 sx_slock(&corefilename_lock); 3453 for (i = 0; format[i] != '\0'; i++) { 3454 switch (format[i]) { 3455 case '%': /* Format character */ 3456 i++; 3457 switch (format[i]) { 3458 case '%': 3459 sbuf_putc(&sb, '%'); 3460 break; 3461 case 'H': /* hostname */ 3462 if (hostname == NULL) { 3463 hostname = malloc(MAXHOSTNAMELEN, 3464 M_TEMP, M_WAITOK); 3465 } 3466 getcredhostname(td->td_ucred, hostname, 3467 MAXHOSTNAMELEN); 3468 sbuf_printf(&sb, "%s", hostname); 3469 break; 3470 case 'I': /* autoincrementing index */ 3471 if (indexpos != -1) { 3472 sbuf_printf(&sb, "%%I"); 3473 break; 3474 } 3475 3476 indexpos = sbuf_len(&sb); 3477 sbuf_printf(&sb, "%u", ncores - 1); 3478 indexlen = sbuf_len(&sb) - indexpos; 3479 break; 3480 case 'N': /* process name */ 3481 sbuf_printf(&sb, "%s", comm); 3482 break; 3483 case 'P': /* process id */ 3484 sbuf_printf(&sb, "%u", pid); 3485 break; 3486 case 'S': /* signal number */ 3487 sbuf_printf(&sb, "%i", signum); 3488 break; 3489 case 'U': /* user id */ 3490 sbuf_printf(&sb, "%u", uid); 3491 break; 3492 default: 3493 log(LOG_ERR, 3494 "Unknown format character %c in " 3495 "corename `%s'\n", format[i], format); 3496 break; 3497 } 3498 break; 3499 default: 3500 sbuf_putc(&sb, format[i]); 3501 break; 3502 } 3503 } 3504 sx_sunlock(&corefilename_lock); 3505 free(hostname, M_TEMP); 3506 if (compress == COMPRESS_GZIP) 3507 sbuf_printf(&sb, GZIP_SUFFIX); 3508 else if (compress == COMPRESS_ZSTD) 3509 sbuf_printf(&sb, ZSTD_SUFFIX); 3510 if (sbuf_error(&sb) != 0) { 3511 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3512 "long\n", (long)pid, comm, (u_long)uid); 3513 sbuf_delete(&sb); 3514 free(name, M_TEMP); 3515 return (ENOMEM); 3516 } 3517 sbuf_finish(&sb); 3518 sbuf_delete(&sb); 3519 3520 if (indexpos != -1) { 3521 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3522 vpp); 3523 if (error != 0) { 3524 log(LOG_ERR, 3525 "pid %d (%s), uid (%u): Path `%s' failed " 3526 "on initial open test, error = %d\n", 3527 pid, comm, uid, name, error); 3528 } 3529 } else { 3530 cmode = S_IRUSR | S_IWUSR; 3531 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3532 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3533 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3534 if ((td->td_proc->p_flag & P_SUGID) != 0) 3535 flags |= O_EXCL; 3536 3537 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3538 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3539 NULL); 3540 if (error == 0) { 3541 *vpp = nd.ni_vp; 3542 NDFREE(&nd, NDF_ONLY_PNBUF); 3543 } 3544 } 3545 3546 if (error != 0) { 3547 #ifdef AUDIT 3548 audit_proc_coredump(td, name, error); 3549 #endif 3550 free(name, M_TEMP); 3551 return (error); 3552 } 3553 *namep = name; 3554 return (0); 3555 } 3556 3557 /* 3558 * Dump a process' core. The main routine does some 3559 * policy checking, and creates the name of the coredump; 3560 * then it passes on a vnode and a size limit to the process-specific 3561 * coredump routine if there is one; if there _is not_ one, it returns 3562 * ENOSYS; otherwise it returns the error from the process-specific routine. 3563 */ 3564 3565 static int 3566 coredump(struct thread *td) 3567 { 3568 struct proc *p = td->td_proc; 3569 struct ucred *cred = td->td_ucred; 3570 struct vnode *vp; 3571 struct flock lf; 3572 struct vattr vattr; 3573 int error, error1, locked; 3574 char *name; /* name of corefile */ 3575 void *rl_cookie; 3576 off_t limit; 3577 char *fullpath, *freepath = NULL; 3578 struct sbuf *sb; 3579 3580 PROC_LOCK_ASSERT(p, MA_OWNED); 3581 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3582 _STOPEVENT(p, S_CORE, 0); 3583 3584 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3585 (p->p_flag2 & P2_NOTRACE) != 0) { 3586 PROC_UNLOCK(p); 3587 return (EFAULT); 3588 } 3589 3590 /* 3591 * Note that the bulk of limit checking is done after 3592 * the corefile is created. The exception is if the limit 3593 * for corefiles is 0, in which case we don't bother 3594 * creating the corefile at all. This layout means that 3595 * a corefile is truncated instead of not being created, 3596 * if it is larger than the limit. 3597 */ 3598 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3599 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3600 PROC_UNLOCK(p); 3601 return (EFBIG); 3602 } 3603 PROC_UNLOCK(p); 3604 3605 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3606 compress_user_cores, p->p_sig, &vp, &name); 3607 if (error != 0) 3608 return (error); 3609 3610 /* 3611 * Don't dump to non-regular files or files with links. 3612 * Do not dump into system files. Effective user must own the corefile. 3613 */ 3614 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3615 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 3616 vattr.va_uid != cred->cr_uid) { 3617 VOP_UNLOCK(vp, 0); 3618 error = EFAULT; 3619 goto out; 3620 } 3621 3622 VOP_UNLOCK(vp, 0); 3623 3624 /* Postpone other writers, including core dumps of other processes. */ 3625 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3626 3627 lf.l_whence = SEEK_SET; 3628 lf.l_start = 0; 3629 lf.l_len = 0; 3630 lf.l_type = F_WRLCK; 3631 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3632 3633 VATTR_NULL(&vattr); 3634 vattr.va_size = 0; 3635 if (set_core_nodump_flag) 3636 vattr.va_flags = UF_NODUMP; 3637 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3638 VOP_SETATTR(vp, &vattr, cred); 3639 VOP_UNLOCK(vp, 0); 3640 PROC_LOCK(p); 3641 p->p_acflag |= ACORE; 3642 PROC_UNLOCK(p); 3643 3644 if (p->p_sysent->sv_coredump != NULL) { 3645 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3646 } else { 3647 error = ENOSYS; 3648 } 3649 3650 if (locked) { 3651 lf.l_type = F_UNLCK; 3652 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3653 } 3654 vn_rangelock_unlock(vp, rl_cookie); 3655 3656 /* 3657 * Notify the userland helper that a process triggered a core dump. 3658 * This allows the helper to run an automated debugging session. 3659 */ 3660 if (error != 0 || coredump_devctl == 0) 3661 goto out; 3662 sb = sbuf_new_auto(); 3663 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3664 goto out2; 3665 sbuf_printf(sb, "comm=\""); 3666 devctl_safe_quote_sb(sb, fullpath); 3667 free(freepath, M_TEMP); 3668 sbuf_printf(sb, "\" core=\""); 3669 3670 /* 3671 * We can't lookup core file vp directly. When we're replacing a core, and 3672 * other random times, we flush the name cache, so it will fail. Instead, 3673 * if the path of the core is relative, add the current dir in front if it. 3674 */ 3675 if (name[0] != '/') { 3676 fullpath = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 3677 if (kern___getcwd(td, fullpath, UIO_SYSSPACE, MAXPATHLEN, MAXPATHLEN) != 0) { 3678 free(fullpath, M_TEMP); 3679 goto out2; 3680 } 3681 devctl_safe_quote_sb(sb, fullpath); 3682 free(fullpath, M_TEMP); 3683 sbuf_putc(sb, '/'); 3684 } 3685 devctl_safe_quote_sb(sb, name); 3686 sbuf_printf(sb, "\""); 3687 if (sbuf_finish(sb) == 0) 3688 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 3689 out2: 3690 sbuf_delete(sb); 3691 out: 3692 error1 = vn_close(vp, FWRITE, cred, td); 3693 if (error == 0) 3694 error = error1; 3695 #ifdef AUDIT 3696 audit_proc_coredump(td, name, error); 3697 #endif 3698 free(name, M_TEMP); 3699 return (error); 3700 } 3701 3702 /* 3703 * Nonexistent system call-- signal process (may want to handle it). Flag 3704 * error in case process won't see signal immediately (blocked or ignored). 3705 */ 3706 #ifndef _SYS_SYSPROTO_H_ 3707 struct nosys_args { 3708 int dummy; 3709 }; 3710 #endif 3711 /* ARGSUSED */ 3712 int 3713 nosys(struct thread *td, struct nosys_args *args) 3714 { 3715 struct proc *p; 3716 3717 p = td->td_proc; 3718 3719 PROC_LOCK(p); 3720 tdsignal(td, SIGSYS); 3721 PROC_UNLOCK(p); 3722 if (kern_lognosys == 1 || kern_lognosys == 3) { 3723 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3724 td->td_sa.code); 3725 } 3726 if (kern_lognosys == 2 || kern_lognosys == 3) { 3727 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3728 td->td_sa.code); 3729 } 3730 return (ENOSYS); 3731 } 3732 3733 /* 3734 * Send a SIGIO or SIGURG signal to a process or process group using stored 3735 * credentials rather than those of the current process. 3736 */ 3737 void 3738 pgsigio(struct sigio **sigiop, int sig, int checkctty) 3739 { 3740 ksiginfo_t ksi; 3741 struct sigio *sigio; 3742 3743 ksiginfo_init(&ksi); 3744 ksi.ksi_signo = sig; 3745 ksi.ksi_code = SI_KERNEL; 3746 3747 SIGIO_LOCK(); 3748 sigio = *sigiop; 3749 if (sigio == NULL) { 3750 SIGIO_UNLOCK(); 3751 return; 3752 } 3753 if (sigio->sio_pgid > 0) { 3754 PROC_LOCK(sigio->sio_proc); 3755 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3756 kern_psignal(sigio->sio_proc, sig); 3757 PROC_UNLOCK(sigio->sio_proc); 3758 } else if (sigio->sio_pgid < 0) { 3759 struct proc *p; 3760 3761 PGRP_LOCK(sigio->sio_pgrp); 3762 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3763 PROC_LOCK(p); 3764 if (p->p_state == PRS_NORMAL && 3765 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3766 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3767 kern_psignal(p, sig); 3768 PROC_UNLOCK(p); 3769 } 3770 PGRP_UNLOCK(sigio->sio_pgrp); 3771 } 3772 SIGIO_UNLOCK(); 3773 } 3774 3775 static int 3776 filt_sigattach(struct knote *kn) 3777 { 3778 struct proc *p = curproc; 3779 3780 kn->kn_ptr.p_proc = p; 3781 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3782 3783 knlist_add(p->p_klist, kn, 0); 3784 3785 return (0); 3786 } 3787 3788 static void 3789 filt_sigdetach(struct knote *kn) 3790 { 3791 struct proc *p = kn->kn_ptr.p_proc; 3792 3793 knlist_remove(p->p_klist, kn, 0); 3794 } 3795 3796 /* 3797 * signal knotes are shared with proc knotes, so we apply a mask to 3798 * the hint in order to differentiate them from process hints. This 3799 * could be avoided by using a signal-specific knote list, but probably 3800 * isn't worth the trouble. 3801 */ 3802 static int 3803 filt_signal(struct knote *kn, long hint) 3804 { 3805 3806 if (hint & NOTE_SIGNAL) { 3807 hint &= ~NOTE_SIGNAL; 3808 3809 if (kn->kn_id == hint) 3810 kn->kn_data++; 3811 } 3812 return (kn->kn_data != 0); 3813 } 3814 3815 struct sigacts * 3816 sigacts_alloc(void) 3817 { 3818 struct sigacts *ps; 3819 3820 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3821 refcount_init(&ps->ps_refcnt, 1); 3822 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3823 return (ps); 3824 } 3825 3826 void 3827 sigacts_free(struct sigacts *ps) 3828 { 3829 3830 if (refcount_release(&ps->ps_refcnt) == 0) 3831 return; 3832 mtx_destroy(&ps->ps_mtx); 3833 free(ps, M_SUBPROC); 3834 } 3835 3836 struct sigacts * 3837 sigacts_hold(struct sigacts *ps) 3838 { 3839 3840 refcount_acquire(&ps->ps_refcnt); 3841 return (ps); 3842 } 3843 3844 void 3845 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3846 { 3847 3848 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3849 mtx_lock(&src->ps_mtx); 3850 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3851 mtx_unlock(&src->ps_mtx); 3852 } 3853 3854 int 3855 sigacts_shared(struct sigacts *ps) 3856 { 3857 3858 return (ps->ps_refcnt > 1); 3859 } 3860