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/lock.h> 61 #include <sys/malloc.h> 62 #include <sys/mutex.h> 63 #include <sys/refcount.h> 64 #include <sys/namei.h> 65 #include <sys/proc.h> 66 #include <sys/procdesc.h> 67 #include <sys/posix4.h> 68 #include <sys/pioctl.h> 69 #include <sys/racct.h> 70 #include <sys/resourcevar.h> 71 #include <sys/sdt.h> 72 #include <sys/sbuf.h> 73 #include <sys/sleepqueue.h> 74 #include <sys/smp.h> 75 #include <sys/stat.h> 76 #include <sys/sx.h> 77 #include <sys/syscallsubr.h> 78 #include <sys/sysctl.h> 79 #include <sys/sysent.h> 80 #include <sys/syslog.h> 81 #include <sys/sysproto.h> 82 #include <sys/timers.h> 83 #include <sys/unistd.h> 84 #include <sys/wait.h> 85 #include <vm/vm.h> 86 #include <vm/vm_extern.h> 87 #include <vm/uma.h> 88 89 #include <sys/jail.h> 90 91 #include <machine/cpu.h> 92 93 #include <security/audit/audit.h> 94 95 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 96 97 SDT_PROVIDER_DECLARE(proc); 98 SDT_PROBE_DEFINE3(proc, , , signal__send, 99 "struct thread *", "struct proc *", "int"); 100 SDT_PROBE_DEFINE2(proc, , , signal__clear, 101 "int", "ksiginfo_t *"); 102 SDT_PROBE_DEFINE3(proc, , , signal__discard, 103 "struct thread *", "struct proc *", "int"); 104 105 static int coredump(struct thread *); 106 static int killpg1(struct thread *td, int sig, int pgid, int all, 107 ksiginfo_t *ksi); 108 static int issignal(struct thread *td); 109 static int sigprop(int sig); 110 static void tdsigwakeup(struct thread *, int, sig_t, int); 111 static int sig_suspend_threads(struct thread *, struct proc *, int); 112 static int filt_sigattach(struct knote *kn); 113 static void filt_sigdetach(struct knote *kn); 114 static int filt_signal(struct knote *kn, long hint); 115 static struct thread *sigtd(struct proc *p, int sig, int prop); 116 static void sigqueue_start(void); 117 118 static uma_zone_t ksiginfo_zone = NULL; 119 struct filterops sig_filtops = { 120 .f_isfd = 0, 121 .f_attach = filt_sigattach, 122 .f_detach = filt_sigdetach, 123 .f_event = filt_signal, 124 }; 125 126 static int kern_logsigexit = 1; 127 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 128 &kern_logsigexit, 0, 129 "Log processes quitting on abnormal signals to syslog(3)"); 130 131 static int kern_forcesigexit = 1; 132 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 133 &kern_forcesigexit, 0, "Force trap signal to be handled"); 134 135 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 136 "POSIX real time signal"); 137 138 static int max_pending_per_proc = 128; 139 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 140 &max_pending_per_proc, 0, "Max pending signals per proc"); 141 142 static int preallocate_siginfo = 1024; 143 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 144 &preallocate_siginfo, 0, "Preallocated signal memory size"); 145 146 static int signal_overflow = 0; 147 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 148 &signal_overflow, 0, "Number of signals overflew"); 149 150 static int signal_alloc_fail = 0; 151 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 152 &signal_alloc_fail, 0, "signals failed to be allocated"); 153 154 static int kern_lognosys = 0; 155 SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 156 "Log invalid syscalls"); 157 158 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 159 160 /* 161 * Policy -- Can ucred cr1 send SIGIO to process cr2? 162 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 163 * in the right situations. 164 */ 165 #define CANSIGIO(cr1, cr2) \ 166 ((cr1)->cr_uid == 0 || \ 167 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 168 (cr1)->cr_uid == (cr2)->cr_ruid || \ 169 (cr1)->cr_ruid == (cr2)->cr_uid || \ 170 (cr1)->cr_uid == (cr2)->cr_uid) 171 172 static int sugid_coredump; 173 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 174 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 175 176 static int capmode_coredump; 177 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 178 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 179 180 static int do_coredump = 1; 181 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 182 &do_coredump, 0, "Enable/Disable coredumps"); 183 184 static int set_core_nodump_flag = 0; 185 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 186 0, "Enable setting the NODUMP flag on coredump files"); 187 188 static int coredump_devctl = 0; 189 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 190 0, "Generate a devctl notification when processes coredump"); 191 192 /* 193 * Signal properties and actions. 194 * The array below categorizes the signals and their default actions 195 * according to the following properties: 196 */ 197 #define SIGPROP_KILL 0x01 /* terminates process by default */ 198 #define SIGPROP_CORE 0x02 /* ditto and coredumps */ 199 #define SIGPROP_STOP 0x04 /* suspend process */ 200 #define SIGPROP_TTYSTOP 0x08 /* ditto, from tty */ 201 #define SIGPROP_IGNORE 0x10 /* ignore by default */ 202 #define SIGPROP_CONT 0x20 /* continue if suspended */ 203 #define SIGPROP_CANTMASK 0x40 /* non-maskable, catchable */ 204 205 static int sigproptbl[NSIG] = { 206 [SIGHUP] = SIGPROP_KILL, 207 [SIGINT] = SIGPROP_KILL, 208 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE, 209 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE, 210 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE, 211 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE, 212 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE, 213 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE, 214 [SIGKILL] = SIGPROP_KILL, 215 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE, 216 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE, 217 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE, 218 [SIGPIPE] = SIGPROP_KILL, 219 [SIGALRM] = SIGPROP_KILL, 220 [SIGTERM] = SIGPROP_KILL, 221 [SIGURG] = SIGPROP_IGNORE, 222 [SIGSTOP] = SIGPROP_STOP, 223 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP, 224 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT, 225 [SIGCHLD] = SIGPROP_IGNORE, 226 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP, 227 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP, 228 [SIGIO] = SIGPROP_IGNORE, 229 [SIGXCPU] = SIGPROP_KILL, 230 [SIGXFSZ] = SIGPROP_KILL, 231 [SIGVTALRM] = SIGPROP_KILL, 232 [SIGPROF] = SIGPROP_KILL, 233 [SIGWINCH] = SIGPROP_IGNORE, 234 [SIGINFO] = SIGPROP_IGNORE, 235 [SIGUSR1] = SIGPROP_KILL, 236 [SIGUSR2] = SIGPROP_KILL, 237 }; 238 239 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 240 241 static void 242 sigqueue_start(void) 243 { 244 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 245 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 246 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 247 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 248 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 249 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 250 } 251 252 ksiginfo_t * 253 ksiginfo_alloc(int wait) 254 { 255 int flags; 256 257 flags = M_ZERO; 258 if (! wait) 259 flags |= M_NOWAIT; 260 if (ksiginfo_zone != NULL) 261 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 262 return (NULL); 263 } 264 265 void 266 ksiginfo_free(ksiginfo_t *ksi) 267 { 268 uma_zfree(ksiginfo_zone, ksi); 269 } 270 271 static __inline int 272 ksiginfo_tryfree(ksiginfo_t *ksi) 273 { 274 if (!(ksi->ksi_flags & KSI_EXT)) { 275 uma_zfree(ksiginfo_zone, ksi); 276 return (1); 277 } 278 return (0); 279 } 280 281 void 282 sigqueue_init(sigqueue_t *list, struct proc *p) 283 { 284 SIGEMPTYSET(list->sq_signals); 285 SIGEMPTYSET(list->sq_kill); 286 SIGEMPTYSET(list->sq_ptrace); 287 TAILQ_INIT(&list->sq_list); 288 list->sq_proc = p; 289 list->sq_flags = SQ_INIT; 290 } 291 292 /* 293 * Get a signal's ksiginfo. 294 * Return: 295 * 0 - signal not found 296 * others - signal number 297 */ 298 static int 299 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 300 { 301 struct proc *p = sq->sq_proc; 302 struct ksiginfo *ksi, *next; 303 int count = 0; 304 305 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 306 307 if (!SIGISMEMBER(sq->sq_signals, signo)) 308 return (0); 309 310 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 311 count++; 312 SIGDELSET(sq->sq_ptrace, signo); 313 si->ksi_flags |= KSI_PTRACE; 314 } 315 if (SIGISMEMBER(sq->sq_kill, signo)) { 316 count++; 317 if (count == 1) 318 SIGDELSET(sq->sq_kill, signo); 319 } 320 321 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 322 if (ksi->ksi_signo == signo) { 323 if (count == 0) { 324 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 325 ksi->ksi_sigq = NULL; 326 ksiginfo_copy(ksi, si); 327 if (ksiginfo_tryfree(ksi) && p != NULL) 328 p->p_pendingcnt--; 329 } 330 if (++count > 1) 331 break; 332 } 333 } 334 335 if (count <= 1) 336 SIGDELSET(sq->sq_signals, signo); 337 si->ksi_signo = signo; 338 return (signo); 339 } 340 341 void 342 sigqueue_take(ksiginfo_t *ksi) 343 { 344 struct ksiginfo *kp; 345 struct proc *p; 346 sigqueue_t *sq; 347 348 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 349 return; 350 351 p = sq->sq_proc; 352 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 353 ksi->ksi_sigq = NULL; 354 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 355 p->p_pendingcnt--; 356 357 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 358 kp = TAILQ_NEXT(kp, ksi_link)) { 359 if (kp->ksi_signo == ksi->ksi_signo) 360 break; 361 } 362 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 363 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 364 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 365 } 366 367 static int 368 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 369 { 370 struct proc *p = sq->sq_proc; 371 struct ksiginfo *ksi; 372 int ret = 0; 373 374 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 375 376 /* 377 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 378 * for these signals. 379 */ 380 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 381 SIGADDSET(sq->sq_kill, signo); 382 goto out_set_bit; 383 } 384 385 /* directly insert the ksi, don't copy it */ 386 if (si->ksi_flags & KSI_INS) { 387 if (si->ksi_flags & KSI_HEAD) 388 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 389 else 390 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 391 si->ksi_sigq = sq; 392 goto out_set_bit; 393 } 394 395 if (__predict_false(ksiginfo_zone == NULL)) { 396 SIGADDSET(sq->sq_kill, signo); 397 goto out_set_bit; 398 } 399 400 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 401 signal_overflow++; 402 ret = EAGAIN; 403 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 404 signal_alloc_fail++; 405 ret = EAGAIN; 406 } else { 407 if (p != NULL) 408 p->p_pendingcnt++; 409 ksiginfo_copy(si, ksi); 410 ksi->ksi_signo = signo; 411 if (si->ksi_flags & KSI_HEAD) 412 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 413 else 414 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 415 ksi->ksi_sigq = sq; 416 } 417 418 if (ret != 0) { 419 if ((si->ksi_flags & KSI_PTRACE) != 0) { 420 SIGADDSET(sq->sq_ptrace, signo); 421 ret = 0; 422 goto out_set_bit; 423 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 424 (si->ksi_flags & KSI_SIGQ) == 0) { 425 SIGADDSET(sq->sq_kill, signo); 426 ret = 0; 427 goto out_set_bit; 428 } 429 return (ret); 430 } 431 432 out_set_bit: 433 SIGADDSET(sq->sq_signals, signo); 434 return (ret); 435 } 436 437 void 438 sigqueue_flush(sigqueue_t *sq) 439 { 440 struct proc *p = sq->sq_proc; 441 ksiginfo_t *ksi; 442 443 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 444 445 if (p != NULL) 446 PROC_LOCK_ASSERT(p, MA_OWNED); 447 448 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 449 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 450 ksi->ksi_sigq = NULL; 451 if (ksiginfo_tryfree(ksi) && p != NULL) 452 p->p_pendingcnt--; 453 } 454 455 SIGEMPTYSET(sq->sq_signals); 456 SIGEMPTYSET(sq->sq_kill); 457 SIGEMPTYSET(sq->sq_ptrace); 458 } 459 460 static void 461 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 462 { 463 sigset_t tmp; 464 struct proc *p1, *p2; 465 ksiginfo_t *ksi, *next; 466 467 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 468 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 469 p1 = src->sq_proc; 470 p2 = dst->sq_proc; 471 /* Move siginfo to target list */ 472 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 473 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 474 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 475 if (p1 != NULL) 476 p1->p_pendingcnt--; 477 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 478 ksi->ksi_sigq = dst; 479 if (p2 != NULL) 480 p2->p_pendingcnt++; 481 } 482 } 483 484 /* Move pending bits to target list */ 485 tmp = src->sq_kill; 486 SIGSETAND(tmp, *set); 487 SIGSETOR(dst->sq_kill, tmp); 488 SIGSETNAND(src->sq_kill, tmp); 489 490 tmp = src->sq_ptrace; 491 SIGSETAND(tmp, *set); 492 SIGSETOR(dst->sq_ptrace, tmp); 493 SIGSETNAND(src->sq_ptrace, tmp); 494 495 tmp = src->sq_signals; 496 SIGSETAND(tmp, *set); 497 SIGSETOR(dst->sq_signals, tmp); 498 SIGSETNAND(src->sq_signals, tmp); 499 } 500 501 #if 0 502 static void 503 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 504 { 505 sigset_t set; 506 507 SIGEMPTYSET(set); 508 SIGADDSET(set, signo); 509 sigqueue_move_set(src, dst, &set); 510 } 511 #endif 512 513 static void 514 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 515 { 516 struct proc *p = sq->sq_proc; 517 ksiginfo_t *ksi, *next; 518 519 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 520 521 /* Remove siginfo queue */ 522 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 523 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 524 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 525 ksi->ksi_sigq = NULL; 526 if (ksiginfo_tryfree(ksi) && p != NULL) 527 p->p_pendingcnt--; 528 } 529 } 530 SIGSETNAND(sq->sq_kill, *set); 531 SIGSETNAND(sq->sq_ptrace, *set); 532 SIGSETNAND(sq->sq_signals, *set); 533 } 534 535 void 536 sigqueue_delete(sigqueue_t *sq, int signo) 537 { 538 sigset_t set; 539 540 SIGEMPTYSET(set); 541 SIGADDSET(set, signo); 542 sigqueue_delete_set(sq, &set); 543 } 544 545 /* Remove a set of signals for a process */ 546 static void 547 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 548 { 549 sigqueue_t worklist; 550 struct thread *td0; 551 552 PROC_LOCK_ASSERT(p, MA_OWNED); 553 554 sigqueue_init(&worklist, NULL); 555 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 556 557 FOREACH_THREAD_IN_PROC(p, td0) 558 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 559 560 sigqueue_flush(&worklist); 561 } 562 563 void 564 sigqueue_delete_proc(struct proc *p, int signo) 565 { 566 sigset_t set; 567 568 SIGEMPTYSET(set); 569 SIGADDSET(set, signo); 570 sigqueue_delete_set_proc(p, &set); 571 } 572 573 static void 574 sigqueue_delete_stopmask_proc(struct proc *p) 575 { 576 sigset_t set; 577 578 SIGEMPTYSET(set); 579 SIGADDSET(set, SIGSTOP); 580 SIGADDSET(set, SIGTSTP); 581 SIGADDSET(set, SIGTTIN); 582 SIGADDSET(set, SIGTTOU); 583 sigqueue_delete_set_proc(p, &set); 584 } 585 586 /* 587 * Determine signal that should be delivered to thread td, the current 588 * thread, 0 if none. If there is a pending stop signal with default 589 * action, the process stops in issignal(). 590 */ 591 int 592 cursig(struct thread *td) 593 { 594 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 595 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 596 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 597 return (SIGPENDING(td) ? issignal(td) : 0); 598 } 599 600 /* 601 * Arrange for ast() to handle unmasked pending signals on return to user 602 * mode. This must be called whenever a signal is added to td_sigqueue or 603 * unmasked in td_sigmask. 604 */ 605 void 606 signotify(struct thread *td) 607 { 608 609 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 610 611 if (SIGPENDING(td)) { 612 thread_lock(td); 613 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 614 thread_unlock(td); 615 } 616 } 617 618 /* 619 * Returns 1 (true) if altstack is configured for the thread, and the 620 * passed stack bottom address falls into the altstack range. Handles 621 * the 43 compat special case where the alt stack size is zero. 622 */ 623 int 624 sigonstack(size_t sp) 625 { 626 struct thread *td; 627 628 td = curthread; 629 if ((td->td_pflags & TDP_ALTSTACK) == 0) 630 return (0); 631 #if defined(COMPAT_43) 632 if (td->td_sigstk.ss_size == 0) 633 return ((td->td_sigstk.ss_flags & SS_ONSTACK) != 0); 634 #endif 635 return (sp >= (size_t)td->td_sigstk.ss_sp && 636 sp < td->td_sigstk.ss_size + (size_t)td->td_sigstk.ss_sp); 637 } 638 639 static __inline int 640 sigprop(int sig) 641 { 642 643 if (sig > 0 && sig < nitems(sigproptbl)) 644 return (sigproptbl[sig]); 645 return (0); 646 } 647 648 int 649 sig_ffs(sigset_t *set) 650 { 651 int i; 652 653 for (i = 0; i < _SIG_WORDS; i++) 654 if (set->__bits[i]) 655 return (ffs(set->__bits[i]) + (i * 32)); 656 return (0); 657 } 658 659 static bool 660 sigact_flag_test(const struct sigaction *act, int flag) 661 { 662 663 /* 664 * SA_SIGINFO is reset when signal disposition is set to 665 * ignore or default. Other flags are kept according to user 666 * settings. 667 */ 668 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 669 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 670 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 671 } 672 673 /* 674 * kern_sigaction 675 * sigaction 676 * freebsd4_sigaction 677 * osigaction 678 */ 679 int 680 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 681 struct sigaction *oact, int flags) 682 { 683 struct sigacts *ps; 684 struct proc *p = td->td_proc; 685 686 if (!_SIG_VALID(sig)) 687 return (EINVAL); 688 if (act != NULL && act->sa_handler != SIG_DFL && 689 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 690 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 691 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 692 return (EINVAL); 693 694 PROC_LOCK(p); 695 ps = p->p_sigacts; 696 mtx_lock(&ps->ps_mtx); 697 if (oact) { 698 memset(oact, 0, sizeof(*oact)); 699 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 700 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 701 oact->sa_flags |= SA_ONSTACK; 702 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 703 oact->sa_flags |= SA_RESTART; 704 if (SIGISMEMBER(ps->ps_sigreset, sig)) 705 oact->sa_flags |= SA_RESETHAND; 706 if (SIGISMEMBER(ps->ps_signodefer, sig)) 707 oact->sa_flags |= SA_NODEFER; 708 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 709 oact->sa_flags |= SA_SIGINFO; 710 oact->sa_sigaction = 711 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 712 } else 713 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 714 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 715 oact->sa_flags |= SA_NOCLDSTOP; 716 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 717 oact->sa_flags |= SA_NOCLDWAIT; 718 } 719 if (act) { 720 if ((sig == SIGKILL || sig == SIGSTOP) && 721 act->sa_handler != SIG_DFL) { 722 mtx_unlock(&ps->ps_mtx); 723 PROC_UNLOCK(p); 724 return (EINVAL); 725 } 726 727 /* 728 * Change setting atomically. 729 */ 730 731 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 732 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 733 if (sigact_flag_test(act, SA_SIGINFO)) { 734 ps->ps_sigact[_SIG_IDX(sig)] = 735 (__sighandler_t *)act->sa_sigaction; 736 SIGADDSET(ps->ps_siginfo, sig); 737 } else { 738 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 739 SIGDELSET(ps->ps_siginfo, sig); 740 } 741 if (!sigact_flag_test(act, SA_RESTART)) 742 SIGADDSET(ps->ps_sigintr, sig); 743 else 744 SIGDELSET(ps->ps_sigintr, sig); 745 if (sigact_flag_test(act, SA_ONSTACK)) 746 SIGADDSET(ps->ps_sigonstack, sig); 747 else 748 SIGDELSET(ps->ps_sigonstack, sig); 749 if (sigact_flag_test(act, SA_RESETHAND)) 750 SIGADDSET(ps->ps_sigreset, sig); 751 else 752 SIGDELSET(ps->ps_sigreset, sig); 753 if (sigact_flag_test(act, SA_NODEFER)) 754 SIGADDSET(ps->ps_signodefer, sig); 755 else 756 SIGDELSET(ps->ps_signodefer, sig); 757 if (sig == SIGCHLD) { 758 if (act->sa_flags & SA_NOCLDSTOP) 759 ps->ps_flag |= PS_NOCLDSTOP; 760 else 761 ps->ps_flag &= ~PS_NOCLDSTOP; 762 if (act->sa_flags & SA_NOCLDWAIT) { 763 /* 764 * Paranoia: since SA_NOCLDWAIT is implemented 765 * by reparenting the dying child to PID 1 (and 766 * trust it to reap the zombie), PID 1 itself 767 * is forbidden to set SA_NOCLDWAIT. 768 */ 769 if (p->p_pid == 1) 770 ps->ps_flag &= ~PS_NOCLDWAIT; 771 else 772 ps->ps_flag |= PS_NOCLDWAIT; 773 } else 774 ps->ps_flag &= ~PS_NOCLDWAIT; 775 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 776 ps->ps_flag |= PS_CLDSIGIGN; 777 else 778 ps->ps_flag &= ~PS_CLDSIGIGN; 779 } 780 /* 781 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 782 * and for signals set to SIG_DFL where the default is to 783 * ignore. However, don't put SIGCONT in ps_sigignore, as we 784 * have to restart the process. 785 */ 786 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 787 (sigprop(sig) & SIGPROP_IGNORE && 788 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 789 /* never to be seen again */ 790 sigqueue_delete_proc(p, sig); 791 if (sig != SIGCONT) 792 /* easier in psignal */ 793 SIGADDSET(ps->ps_sigignore, sig); 794 SIGDELSET(ps->ps_sigcatch, sig); 795 } else { 796 SIGDELSET(ps->ps_sigignore, sig); 797 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 798 SIGDELSET(ps->ps_sigcatch, sig); 799 else 800 SIGADDSET(ps->ps_sigcatch, sig); 801 } 802 #ifdef COMPAT_FREEBSD4 803 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 804 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 805 (flags & KSA_FREEBSD4) == 0) 806 SIGDELSET(ps->ps_freebsd4, sig); 807 else 808 SIGADDSET(ps->ps_freebsd4, sig); 809 #endif 810 #ifdef COMPAT_43 811 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 812 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 813 (flags & KSA_OSIGSET) == 0) 814 SIGDELSET(ps->ps_osigset, sig); 815 else 816 SIGADDSET(ps->ps_osigset, sig); 817 #endif 818 } 819 mtx_unlock(&ps->ps_mtx); 820 PROC_UNLOCK(p); 821 return (0); 822 } 823 824 #ifndef _SYS_SYSPROTO_H_ 825 struct sigaction_args { 826 int sig; 827 struct sigaction *act; 828 struct sigaction *oact; 829 }; 830 #endif 831 int 832 sys_sigaction(struct thread *td, struct sigaction_args *uap) 833 { 834 struct sigaction act, oact; 835 struct sigaction *actp, *oactp; 836 int error; 837 838 actp = (uap->act != NULL) ? &act : NULL; 839 oactp = (uap->oact != NULL) ? &oact : NULL; 840 if (actp) { 841 error = copyin(uap->act, actp, sizeof(act)); 842 if (error) 843 return (error); 844 } 845 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 846 if (oactp && !error) 847 error = copyout(oactp, uap->oact, sizeof(oact)); 848 return (error); 849 } 850 851 #ifdef COMPAT_FREEBSD4 852 #ifndef _SYS_SYSPROTO_H_ 853 struct freebsd4_sigaction_args { 854 int sig; 855 struct sigaction *act; 856 struct sigaction *oact; 857 }; 858 #endif 859 int 860 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 861 { 862 struct sigaction act, oact; 863 struct sigaction *actp, *oactp; 864 int error; 865 866 867 actp = (uap->act != NULL) ? &act : NULL; 868 oactp = (uap->oact != NULL) ? &oact : NULL; 869 if (actp) { 870 error = copyin(uap->act, actp, sizeof(act)); 871 if (error) 872 return (error); 873 } 874 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 875 if (oactp && !error) 876 error = copyout(oactp, uap->oact, sizeof(oact)); 877 return (error); 878 } 879 #endif /* COMAPT_FREEBSD4 */ 880 881 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 882 #ifndef _SYS_SYSPROTO_H_ 883 struct osigaction_args { 884 int signum; 885 struct osigaction *nsa; 886 struct osigaction *osa; 887 }; 888 #endif 889 int 890 osigaction(struct thread *td, struct osigaction_args *uap) 891 { 892 struct osigaction sa; 893 struct sigaction nsa, osa; 894 struct sigaction *nsap, *osap; 895 int error; 896 897 if (uap->signum <= 0 || uap->signum >= ONSIG) 898 return (EINVAL); 899 900 nsap = (uap->nsa != NULL) ? &nsa : NULL; 901 osap = (uap->osa != NULL) ? &osa : NULL; 902 903 if (nsap) { 904 error = copyin(uap->nsa, &sa, sizeof(sa)); 905 if (error) 906 return (error); 907 nsap->sa_handler = sa.sa_handler; 908 nsap->sa_flags = sa.sa_flags; 909 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 910 } 911 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 912 if (osap && !error) { 913 sa.sa_handler = osap->sa_handler; 914 sa.sa_flags = osap->sa_flags; 915 SIG2OSIG(osap->sa_mask, sa.sa_mask); 916 error = copyout(&sa, uap->osa, sizeof(sa)); 917 } 918 return (error); 919 } 920 921 #if !defined(__i386__) 922 /* Avoid replicating the same stub everywhere */ 923 int 924 osigreturn(struct thread *td, struct osigreturn_args *uap) 925 { 926 927 return (nosys(td, (struct nosys_args *)uap)); 928 } 929 #endif 930 #endif /* COMPAT_43 */ 931 932 /* 933 * Initialize signal state for process 0; 934 * set to ignore signals that are ignored by default. 935 */ 936 void 937 siginit(struct proc *p) 938 { 939 int i; 940 struct sigacts *ps; 941 942 PROC_LOCK(p); 943 ps = p->p_sigacts; 944 mtx_lock(&ps->ps_mtx); 945 for (i = 1; i <= NSIG; i++) { 946 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 947 SIGADDSET(ps->ps_sigignore, i); 948 } 949 } 950 mtx_unlock(&ps->ps_mtx); 951 PROC_UNLOCK(p); 952 } 953 954 /* 955 * Reset specified signal to the default disposition. 956 */ 957 static void 958 sigdflt(struct sigacts *ps, int sig) 959 { 960 961 mtx_assert(&ps->ps_mtx, MA_OWNED); 962 SIGDELSET(ps->ps_sigcatch, sig); 963 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 964 SIGADDSET(ps->ps_sigignore, sig); 965 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 966 SIGDELSET(ps->ps_siginfo, sig); 967 } 968 969 /* 970 * Reset signals for an exec of the specified process. 971 */ 972 void 973 execsigs(struct proc *p) 974 { 975 sigset_t osigignore; 976 struct sigacts *ps; 977 int sig; 978 struct thread *td; 979 980 /* 981 * Reset caught signals. Held signals remain held 982 * through td_sigmask (unless they were caught, 983 * and are now ignored by default). 984 */ 985 PROC_LOCK_ASSERT(p, MA_OWNED); 986 ps = p->p_sigacts; 987 mtx_lock(&ps->ps_mtx); 988 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 989 sig = sig_ffs(&ps->ps_sigcatch); 990 sigdflt(ps, sig); 991 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 992 sigqueue_delete_proc(p, sig); 993 } 994 995 /* 996 * As CloudABI processes cannot modify signal handlers, fully 997 * reset all signals to their default behavior. Do ignore 998 * SIGPIPE, as it would otherwise be impossible to recover from 999 * writes to broken pipes and sockets. 1000 */ 1001 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 1002 osigignore = ps->ps_sigignore; 1003 while (SIGNOTEMPTY(osigignore)) { 1004 sig = sig_ffs(&osigignore); 1005 SIGDELSET(osigignore, sig); 1006 if (sig != SIGPIPE) 1007 sigdflt(ps, sig); 1008 } 1009 SIGADDSET(ps->ps_sigignore, SIGPIPE); 1010 } 1011 1012 /* 1013 * Reset stack state to the user stack. 1014 * Clear set of signals caught on the signal stack. 1015 */ 1016 td = curthread; 1017 MPASS(td->td_proc == p); 1018 td->td_sigstk.ss_flags = SS_DISABLE; 1019 td->td_sigstk.ss_size = 0; 1020 td->td_sigstk.ss_sp = 0; 1021 td->td_pflags &= ~TDP_ALTSTACK; 1022 /* 1023 * Reset no zombies if child dies flag as Solaris does. 1024 */ 1025 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1026 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1027 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1028 mtx_unlock(&ps->ps_mtx); 1029 } 1030 1031 /* 1032 * kern_sigprocmask() 1033 * 1034 * Manipulate signal mask. 1035 */ 1036 int 1037 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1038 int flags) 1039 { 1040 sigset_t new_block, oset1; 1041 struct proc *p; 1042 int error; 1043 1044 p = td->td_proc; 1045 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1046 PROC_LOCK_ASSERT(p, MA_OWNED); 1047 else 1048 PROC_LOCK(p); 1049 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1050 ? MA_OWNED : MA_NOTOWNED); 1051 if (oset != NULL) 1052 *oset = td->td_sigmask; 1053 1054 error = 0; 1055 if (set != NULL) { 1056 switch (how) { 1057 case SIG_BLOCK: 1058 SIG_CANTMASK(*set); 1059 oset1 = td->td_sigmask; 1060 SIGSETOR(td->td_sigmask, *set); 1061 new_block = td->td_sigmask; 1062 SIGSETNAND(new_block, oset1); 1063 break; 1064 case SIG_UNBLOCK: 1065 SIGSETNAND(td->td_sigmask, *set); 1066 signotify(td); 1067 goto out; 1068 case SIG_SETMASK: 1069 SIG_CANTMASK(*set); 1070 oset1 = td->td_sigmask; 1071 if (flags & SIGPROCMASK_OLD) 1072 SIGSETLO(td->td_sigmask, *set); 1073 else 1074 td->td_sigmask = *set; 1075 new_block = td->td_sigmask; 1076 SIGSETNAND(new_block, oset1); 1077 signotify(td); 1078 break; 1079 default: 1080 error = EINVAL; 1081 goto out; 1082 } 1083 1084 /* 1085 * The new_block set contains signals that were not previously 1086 * blocked, but are blocked now. 1087 * 1088 * In case we block any signal that was not previously blocked 1089 * for td, and process has the signal pending, try to schedule 1090 * signal delivery to some thread that does not block the 1091 * signal, possibly waking it up. 1092 */ 1093 if (p->p_numthreads != 1) 1094 reschedule_signals(p, new_block, flags); 1095 } 1096 1097 out: 1098 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1099 PROC_UNLOCK(p); 1100 return (error); 1101 } 1102 1103 #ifndef _SYS_SYSPROTO_H_ 1104 struct sigprocmask_args { 1105 int how; 1106 const sigset_t *set; 1107 sigset_t *oset; 1108 }; 1109 #endif 1110 int 1111 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1112 { 1113 sigset_t set, oset; 1114 sigset_t *setp, *osetp; 1115 int error; 1116 1117 setp = (uap->set != NULL) ? &set : NULL; 1118 osetp = (uap->oset != NULL) ? &oset : NULL; 1119 if (setp) { 1120 error = copyin(uap->set, setp, sizeof(set)); 1121 if (error) 1122 return (error); 1123 } 1124 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1125 if (osetp && !error) { 1126 error = copyout(osetp, uap->oset, sizeof(oset)); 1127 } 1128 return (error); 1129 } 1130 1131 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1132 #ifndef _SYS_SYSPROTO_H_ 1133 struct osigprocmask_args { 1134 int how; 1135 osigset_t mask; 1136 }; 1137 #endif 1138 int 1139 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1140 { 1141 sigset_t set, oset; 1142 int error; 1143 1144 OSIG2SIG(uap->mask, set); 1145 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1146 SIG2OSIG(oset, td->td_retval[0]); 1147 return (error); 1148 } 1149 #endif /* COMPAT_43 */ 1150 1151 int 1152 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1153 { 1154 ksiginfo_t ksi; 1155 sigset_t set; 1156 int error; 1157 1158 error = copyin(uap->set, &set, sizeof(set)); 1159 if (error) { 1160 td->td_retval[0] = error; 1161 return (0); 1162 } 1163 1164 error = kern_sigtimedwait(td, set, &ksi, NULL); 1165 if (error) { 1166 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1167 error = ERESTART; 1168 if (error == ERESTART) 1169 return (error); 1170 td->td_retval[0] = error; 1171 return (0); 1172 } 1173 1174 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1175 td->td_retval[0] = error; 1176 return (0); 1177 } 1178 1179 int 1180 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1181 { 1182 struct timespec ts; 1183 struct timespec *timeout; 1184 sigset_t set; 1185 ksiginfo_t ksi; 1186 int error; 1187 1188 if (uap->timeout) { 1189 error = copyin(uap->timeout, &ts, sizeof(ts)); 1190 if (error) 1191 return (error); 1192 1193 timeout = &ts; 1194 } else 1195 timeout = NULL; 1196 1197 error = copyin(uap->set, &set, sizeof(set)); 1198 if (error) 1199 return (error); 1200 1201 error = kern_sigtimedwait(td, set, &ksi, timeout); 1202 if (error) 1203 return (error); 1204 1205 if (uap->info) 1206 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1207 1208 if (error == 0) 1209 td->td_retval[0] = ksi.ksi_signo; 1210 return (error); 1211 } 1212 1213 int 1214 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1215 { 1216 ksiginfo_t ksi; 1217 sigset_t set; 1218 int error; 1219 1220 error = copyin(uap->set, &set, sizeof(set)); 1221 if (error) 1222 return (error); 1223 1224 error = kern_sigtimedwait(td, set, &ksi, NULL); 1225 if (error) 1226 return (error); 1227 1228 if (uap->info) 1229 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1230 1231 if (error == 0) 1232 td->td_retval[0] = ksi.ksi_signo; 1233 return (error); 1234 } 1235 1236 static void 1237 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1238 { 1239 struct thread *thr; 1240 1241 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1242 if (thr == td) 1243 thr->td_si = *si; 1244 else 1245 thr->td_si.si_signo = 0; 1246 } 1247 } 1248 1249 int 1250 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1251 struct timespec *timeout) 1252 { 1253 struct sigacts *ps; 1254 sigset_t saved_mask, new_block; 1255 struct proc *p; 1256 int error, sig, timo, timevalid = 0; 1257 struct timespec rts, ets, ts; 1258 struct timeval tv; 1259 1260 p = td->td_proc; 1261 error = 0; 1262 ets.tv_sec = 0; 1263 ets.tv_nsec = 0; 1264 1265 if (timeout != NULL) { 1266 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1267 timevalid = 1; 1268 getnanouptime(&rts); 1269 timespecadd(&rts, timeout, &ets); 1270 } 1271 } 1272 ksiginfo_init(ksi); 1273 /* Some signals can not be waited for. */ 1274 SIG_CANTMASK(waitset); 1275 ps = p->p_sigacts; 1276 PROC_LOCK(p); 1277 saved_mask = td->td_sigmask; 1278 SIGSETNAND(td->td_sigmask, waitset); 1279 for (;;) { 1280 mtx_lock(&ps->ps_mtx); 1281 sig = cursig(td); 1282 mtx_unlock(&ps->ps_mtx); 1283 KASSERT(sig >= 0, ("sig %d", sig)); 1284 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1285 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1286 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1287 error = 0; 1288 break; 1289 } 1290 } 1291 1292 if (error != 0) 1293 break; 1294 1295 /* 1296 * POSIX says this must be checked after looking for pending 1297 * signals. 1298 */ 1299 if (timeout != NULL) { 1300 if (!timevalid) { 1301 error = EINVAL; 1302 break; 1303 } 1304 getnanouptime(&rts); 1305 if (timespeccmp(&rts, &ets, >=)) { 1306 error = EAGAIN; 1307 break; 1308 } 1309 timespecsub(&ets, &rts, &ts); 1310 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1311 timo = tvtohz(&tv); 1312 } else { 1313 timo = 0; 1314 } 1315 1316 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1317 1318 if (timeout != NULL) { 1319 if (error == ERESTART) { 1320 /* Timeout can not be restarted. */ 1321 error = EINTR; 1322 } else if (error == EAGAIN) { 1323 /* We will calculate timeout by ourself. */ 1324 error = 0; 1325 } 1326 } 1327 } 1328 1329 new_block = saved_mask; 1330 SIGSETNAND(new_block, td->td_sigmask); 1331 td->td_sigmask = saved_mask; 1332 /* 1333 * Fewer signals can be delivered to us, reschedule signal 1334 * notification. 1335 */ 1336 if (p->p_numthreads != 1) 1337 reschedule_signals(p, new_block, 0); 1338 1339 if (error == 0) { 1340 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1341 1342 if (ksi->ksi_code == SI_TIMER) 1343 itimer_accept(p, ksi->ksi_timerid, ksi); 1344 1345 #ifdef KTRACE 1346 if (KTRPOINT(td, KTR_PSIG)) { 1347 sig_t action; 1348 1349 mtx_lock(&ps->ps_mtx); 1350 action = ps->ps_sigact[_SIG_IDX(sig)]; 1351 mtx_unlock(&ps->ps_mtx); 1352 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1353 } 1354 #endif 1355 if (sig == SIGKILL) { 1356 proc_td_siginfo_capture(td, &ksi->ksi_info); 1357 sigexit(td, sig); 1358 } 1359 } 1360 PROC_UNLOCK(p); 1361 return (error); 1362 } 1363 1364 #ifndef _SYS_SYSPROTO_H_ 1365 struct sigpending_args { 1366 sigset_t *set; 1367 }; 1368 #endif 1369 int 1370 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1371 { 1372 struct proc *p = td->td_proc; 1373 sigset_t pending; 1374 1375 PROC_LOCK(p); 1376 pending = p->p_sigqueue.sq_signals; 1377 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1378 PROC_UNLOCK(p); 1379 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1380 } 1381 1382 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1383 #ifndef _SYS_SYSPROTO_H_ 1384 struct osigpending_args { 1385 int dummy; 1386 }; 1387 #endif 1388 int 1389 osigpending(struct thread *td, struct osigpending_args *uap) 1390 { 1391 struct proc *p = td->td_proc; 1392 sigset_t pending; 1393 1394 PROC_LOCK(p); 1395 pending = p->p_sigqueue.sq_signals; 1396 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1397 PROC_UNLOCK(p); 1398 SIG2OSIG(pending, td->td_retval[0]); 1399 return (0); 1400 } 1401 #endif /* COMPAT_43 */ 1402 1403 #if defined(COMPAT_43) 1404 /* 1405 * Generalized interface signal handler, 4.3-compatible. 1406 */ 1407 #ifndef _SYS_SYSPROTO_H_ 1408 struct osigvec_args { 1409 int signum; 1410 struct sigvec *nsv; 1411 struct sigvec *osv; 1412 }; 1413 #endif 1414 /* ARGSUSED */ 1415 int 1416 osigvec(struct thread *td, struct osigvec_args *uap) 1417 { 1418 struct sigvec vec; 1419 struct sigaction nsa, osa; 1420 struct sigaction *nsap, *osap; 1421 int error; 1422 1423 if (uap->signum <= 0 || uap->signum >= ONSIG) 1424 return (EINVAL); 1425 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1426 osap = (uap->osv != NULL) ? &osa : NULL; 1427 if (nsap) { 1428 error = copyin(uap->nsv, &vec, sizeof(vec)); 1429 if (error) 1430 return (error); 1431 nsap->sa_handler = vec.sv_handler; 1432 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1433 nsap->sa_flags = vec.sv_flags; 1434 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1435 } 1436 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1437 if (osap && !error) { 1438 vec.sv_handler = osap->sa_handler; 1439 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1440 vec.sv_flags = osap->sa_flags; 1441 vec.sv_flags &= ~SA_NOCLDWAIT; 1442 vec.sv_flags ^= SA_RESTART; 1443 error = copyout(&vec, uap->osv, sizeof(vec)); 1444 } 1445 return (error); 1446 } 1447 1448 #ifndef _SYS_SYSPROTO_H_ 1449 struct osigblock_args { 1450 int mask; 1451 }; 1452 #endif 1453 int 1454 osigblock(struct thread *td, struct osigblock_args *uap) 1455 { 1456 sigset_t set, oset; 1457 1458 OSIG2SIG(uap->mask, set); 1459 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1460 SIG2OSIG(oset, td->td_retval[0]); 1461 return (0); 1462 } 1463 1464 #ifndef _SYS_SYSPROTO_H_ 1465 struct osigsetmask_args { 1466 int mask; 1467 }; 1468 #endif 1469 int 1470 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1471 { 1472 sigset_t set, oset; 1473 1474 OSIG2SIG(uap->mask, set); 1475 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1476 SIG2OSIG(oset, td->td_retval[0]); 1477 return (0); 1478 } 1479 #endif /* COMPAT_43 */ 1480 1481 /* 1482 * Suspend calling thread until signal, providing mask to be set in the 1483 * meantime. 1484 */ 1485 #ifndef _SYS_SYSPROTO_H_ 1486 struct sigsuspend_args { 1487 const sigset_t *sigmask; 1488 }; 1489 #endif 1490 /* ARGSUSED */ 1491 int 1492 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1493 { 1494 sigset_t mask; 1495 int error; 1496 1497 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1498 if (error) 1499 return (error); 1500 return (kern_sigsuspend(td, mask)); 1501 } 1502 1503 int 1504 kern_sigsuspend(struct thread *td, sigset_t mask) 1505 { 1506 struct proc *p = td->td_proc; 1507 int has_sig, sig; 1508 1509 /* 1510 * When returning from sigsuspend, we want 1511 * the old mask to be restored after the 1512 * signal handler has finished. Thus, we 1513 * save it here and mark the sigacts structure 1514 * to indicate this. 1515 */ 1516 PROC_LOCK(p); 1517 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1518 SIGPROCMASK_PROC_LOCKED); 1519 td->td_pflags |= TDP_OLDMASK; 1520 1521 /* 1522 * Process signals now. Otherwise, we can get spurious wakeup 1523 * due to signal entered process queue, but delivered to other 1524 * thread. But sigsuspend should return only on signal 1525 * delivery. 1526 */ 1527 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1528 for (has_sig = 0; !has_sig;) { 1529 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1530 0) == 0) 1531 /* void */; 1532 thread_suspend_check(0); 1533 mtx_lock(&p->p_sigacts->ps_mtx); 1534 while ((sig = cursig(td)) != 0) { 1535 KASSERT(sig >= 0, ("sig %d", sig)); 1536 has_sig += postsig(sig); 1537 } 1538 mtx_unlock(&p->p_sigacts->ps_mtx); 1539 } 1540 PROC_UNLOCK(p); 1541 td->td_errno = EINTR; 1542 td->td_pflags |= TDP_NERRNO; 1543 return (EJUSTRETURN); 1544 } 1545 1546 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1547 /* 1548 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1549 * convention: libc stub passes mask, not pointer, to save a copyin. 1550 */ 1551 #ifndef _SYS_SYSPROTO_H_ 1552 struct osigsuspend_args { 1553 osigset_t mask; 1554 }; 1555 #endif 1556 /* ARGSUSED */ 1557 int 1558 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1559 { 1560 sigset_t mask; 1561 1562 OSIG2SIG(uap->mask, mask); 1563 return (kern_sigsuspend(td, mask)); 1564 } 1565 #endif /* COMPAT_43 */ 1566 1567 #if defined(COMPAT_43) 1568 #ifndef _SYS_SYSPROTO_H_ 1569 struct osigstack_args { 1570 struct sigstack *nss; 1571 struct sigstack *oss; 1572 }; 1573 #endif 1574 /* ARGSUSED */ 1575 int 1576 osigstack(struct thread *td, struct osigstack_args *uap) 1577 { 1578 struct sigstack nss, oss; 1579 int error = 0; 1580 1581 if (uap->nss != NULL) { 1582 error = copyin(uap->nss, &nss, sizeof(nss)); 1583 if (error) 1584 return (error); 1585 } 1586 oss.ss_sp = td->td_sigstk.ss_sp; 1587 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1588 if (uap->nss != NULL) { 1589 td->td_sigstk.ss_sp = nss.ss_sp; 1590 td->td_sigstk.ss_size = 0; 1591 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1592 td->td_pflags |= TDP_ALTSTACK; 1593 } 1594 if (uap->oss != NULL) 1595 error = copyout(&oss, uap->oss, sizeof(oss)); 1596 1597 return (error); 1598 } 1599 #endif /* COMPAT_43 */ 1600 1601 #ifndef _SYS_SYSPROTO_H_ 1602 struct sigaltstack_args { 1603 stack_t *ss; 1604 stack_t *oss; 1605 }; 1606 #endif 1607 /* ARGSUSED */ 1608 int 1609 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1610 { 1611 stack_t ss, oss; 1612 int error; 1613 1614 if (uap->ss != NULL) { 1615 error = copyin(uap->ss, &ss, sizeof(ss)); 1616 if (error) 1617 return (error); 1618 } 1619 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1620 (uap->oss != NULL) ? &oss : NULL); 1621 if (error) 1622 return (error); 1623 if (uap->oss != NULL) 1624 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1625 return (error); 1626 } 1627 1628 int 1629 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1630 { 1631 struct proc *p = td->td_proc; 1632 int oonstack; 1633 1634 oonstack = sigonstack(cpu_getstack(td)); 1635 1636 if (oss != NULL) { 1637 *oss = td->td_sigstk; 1638 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1639 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1640 } 1641 1642 if (ss != NULL) { 1643 if (oonstack) 1644 return (EPERM); 1645 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1646 return (EINVAL); 1647 if (!(ss->ss_flags & SS_DISABLE)) { 1648 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1649 return (ENOMEM); 1650 1651 td->td_sigstk = *ss; 1652 td->td_pflags |= TDP_ALTSTACK; 1653 } else { 1654 td->td_pflags &= ~TDP_ALTSTACK; 1655 } 1656 } 1657 return (0); 1658 } 1659 1660 /* 1661 * Common code for kill process group/broadcast kill. 1662 * cp is calling process. 1663 */ 1664 static int 1665 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1666 { 1667 struct proc *p; 1668 struct pgrp *pgrp; 1669 int err; 1670 int ret; 1671 1672 ret = ESRCH; 1673 if (all) { 1674 /* 1675 * broadcast 1676 */ 1677 sx_slock(&allproc_lock); 1678 FOREACH_PROC_IN_SYSTEM(p) { 1679 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1680 p == td->td_proc || p->p_state == PRS_NEW) { 1681 continue; 1682 } 1683 PROC_LOCK(p); 1684 err = p_cansignal(td, p, sig); 1685 if (err == 0) { 1686 if (sig) 1687 pksignal(p, sig, ksi); 1688 ret = err; 1689 } 1690 else if (ret == ESRCH) 1691 ret = err; 1692 PROC_UNLOCK(p); 1693 } 1694 sx_sunlock(&allproc_lock); 1695 } else { 1696 sx_slock(&proctree_lock); 1697 if (pgid == 0) { 1698 /* 1699 * zero pgid means send to my process group. 1700 */ 1701 pgrp = td->td_proc->p_pgrp; 1702 PGRP_LOCK(pgrp); 1703 } else { 1704 pgrp = pgfind(pgid); 1705 if (pgrp == NULL) { 1706 sx_sunlock(&proctree_lock); 1707 return (ESRCH); 1708 } 1709 } 1710 sx_sunlock(&proctree_lock); 1711 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1712 PROC_LOCK(p); 1713 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1714 p->p_state == PRS_NEW) { 1715 PROC_UNLOCK(p); 1716 continue; 1717 } 1718 err = p_cansignal(td, p, sig); 1719 if (err == 0) { 1720 if (sig) 1721 pksignal(p, sig, ksi); 1722 ret = err; 1723 } 1724 else if (ret == ESRCH) 1725 ret = err; 1726 PROC_UNLOCK(p); 1727 } 1728 PGRP_UNLOCK(pgrp); 1729 } 1730 return (ret); 1731 } 1732 1733 #ifndef _SYS_SYSPROTO_H_ 1734 struct kill_args { 1735 int pid; 1736 int signum; 1737 }; 1738 #endif 1739 /* ARGSUSED */ 1740 int 1741 sys_kill(struct thread *td, struct kill_args *uap) 1742 { 1743 ksiginfo_t ksi; 1744 struct proc *p; 1745 int error; 1746 1747 /* 1748 * A process in capability mode can send signals only to himself. 1749 * The main rationale behind this is that abort(3) is implemented as 1750 * kill(getpid(), SIGABRT). 1751 */ 1752 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1753 return (ECAPMODE); 1754 1755 AUDIT_ARG_SIGNUM(uap->signum); 1756 AUDIT_ARG_PID(uap->pid); 1757 if ((u_int)uap->signum > _SIG_MAXSIG) 1758 return (EINVAL); 1759 1760 ksiginfo_init(&ksi); 1761 ksi.ksi_signo = uap->signum; 1762 ksi.ksi_code = SI_USER; 1763 ksi.ksi_pid = td->td_proc->p_pid; 1764 ksi.ksi_uid = td->td_ucred->cr_ruid; 1765 1766 if (uap->pid > 0) { 1767 /* kill single process */ 1768 if ((p = pfind_any(uap->pid)) == NULL) 1769 return (ESRCH); 1770 AUDIT_ARG_PROCESS(p); 1771 error = p_cansignal(td, p, uap->signum); 1772 if (error == 0 && uap->signum) 1773 pksignal(p, uap->signum, &ksi); 1774 PROC_UNLOCK(p); 1775 return (error); 1776 } 1777 switch (uap->pid) { 1778 case -1: /* broadcast signal */ 1779 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1780 case 0: /* signal own process group */ 1781 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1782 default: /* negative explicit process group */ 1783 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1784 } 1785 /* NOTREACHED */ 1786 } 1787 1788 int 1789 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1790 { 1791 struct proc *p; 1792 int error; 1793 1794 AUDIT_ARG_SIGNUM(uap->signum); 1795 AUDIT_ARG_FD(uap->fd); 1796 if ((u_int)uap->signum > _SIG_MAXSIG) 1797 return (EINVAL); 1798 1799 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1800 if (error) 1801 return (error); 1802 AUDIT_ARG_PROCESS(p); 1803 error = p_cansignal(td, p, uap->signum); 1804 if (error == 0 && uap->signum) 1805 kern_psignal(p, uap->signum); 1806 PROC_UNLOCK(p); 1807 return (error); 1808 } 1809 1810 #if defined(COMPAT_43) 1811 #ifndef _SYS_SYSPROTO_H_ 1812 struct okillpg_args { 1813 int pgid; 1814 int signum; 1815 }; 1816 #endif 1817 /* ARGSUSED */ 1818 int 1819 okillpg(struct thread *td, struct okillpg_args *uap) 1820 { 1821 ksiginfo_t ksi; 1822 1823 AUDIT_ARG_SIGNUM(uap->signum); 1824 AUDIT_ARG_PID(uap->pgid); 1825 if ((u_int)uap->signum > _SIG_MAXSIG) 1826 return (EINVAL); 1827 1828 ksiginfo_init(&ksi); 1829 ksi.ksi_signo = uap->signum; 1830 ksi.ksi_code = SI_USER; 1831 ksi.ksi_pid = td->td_proc->p_pid; 1832 ksi.ksi_uid = td->td_ucred->cr_ruid; 1833 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1834 } 1835 #endif /* COMPAT_43 */ 1836 1837 #ifndef _SYS_SYSPROTO_H_ 1838 struct sigqueue_args { 1839 pid_t pid; 1840 int signum; 1841 /* union sigval */ void *value; 1842 }; 1843 #endif 1844 int 1845 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1846 { 1847 union sigval sv; 1848 1849 sv.sival_ptr = uap->value; 1850 1851 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1852 } 1853 1854 int 1855 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1856 { 1857 ksiginfo_t ksi; 1858 struct proc *p; 1859 int error; 1860 1861 if ((u_int)signum > _SIG_MAXSIG) 1862 return (EINVAL); 1863 1864 /* 1865 * Specification says sigqueue can only send signal to 1866 * single process. 1867 */ 1868 if (pid <= 0) 1869 return (EINVAL); 1870 1871 if ((p = pfind_any(pid)) == NULL) 1872 return (ESRCH); 1873 error = p_cansignal(td, p, signum); 1874 if (error == 0 && signum != 0) { 1875 ksiginfo_init(&ksi); 1876 ksi.ksi_flags = KSI_SIGQ; 1877 ksi.ksi_signo = signum; 1878 ksi.ksi_code = SI_QUEUE; 1879 ksi.ksi_pid = td->td_proc->p_pid; 1880 ksi.ksi_uid = td->td_ucred->cr_ruid; 1881 ksi.ksi_value = *value; 1882 error = pksignal(p, ksi.ksi_signo, &ksi); 1883 } 1884 PROC_UNLOCK(p); 1885 return (error); 1886 } 1887 1888 /* 1889 * Send a signal to a process group. 1890 */ 1891 void 1892 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1893 { 1894 struct pgrp *pgrp; 1895 1896 if (pgid != 0) { 1897 sx_slock(&proctree_lock); 1898 pgrp = pgfind(pgid); 1899 sx_sunlock(&proctree_lock); 1900 if (pgrp != NULL) { 1901 pgsignal(pgrp, sig, 0, ksi); 1902 PGRP_UNLOCK(pgrp); 1903 } 1904 } 1905 } 1906 1907 /* 1908 * Send a signal to a process group. If checktty is 1, 1909 * limit to members which have a controlling terminal. 1910 */ 1911 void 1912 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1913 { 1914 struct proc *p; 1915 1916 if (pgrp) { 1917 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1918 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1919 PROC_LOCK(p); 1920 if (p->p_state == PRS_NORMAL && 1921 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1922 pksignal(p, sig, ksi); 1923 PROC_UNLOCK(p); 1924 } 1925 } 1926 } 1927 1928 1929 /* 1930 * Recalculate the signal mask and reset the signal disposition after 1931 * usermode frame for delivery is formed. Should be called after 1932 * mach-specific routine, because sysent->sv_sendsig() needs correct 1933 * ps_siginfo and signal mask. 1934 */ 1935 static void 1936 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1937 { 1938 sigset_t mask; 1939 1940 mtx_assert(&ps->ps_mtx, MA_OWNED); 1941 td->td_ru.ru_nsignals++; 1942 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1943 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1944 SIGADDSET(mask, sig); 1945 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1946 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1947 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1948 sigdflt(ps, sig); 1949 } 1950 1951 1952 /* 1953 * Send a signal caused by a trap to the current thread. If it will be 1954 * caught immediately, deliver it with correct code. Otherwise, post it 1955 * normally. 1956 */ 1957 void 1958 trapsignal(struct thread *td, ksiginfo_t *ksi) 1959 { 1960 struct sigacts *ps; 1961 struct proc *p; 1962 int sig; 1963 int code; 1964 1965 p = td->td_proc; 1966 sig = ksi->ksi_signo; 1967 code = ksi->ksi_code; 1968 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1969 1970 PROC_LOCK(p); 1971 ps = p->p_sigacts; 1972 mtx_lock(&ps->ps_mtx); 1973 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1974 !SIGISMEMBER(td->td_sigmask, sig)) { 1975 #ifdef KTRACE 1976 if (KTRPOINT(curthread, KTR_PSIG)) 1977 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1978 &td->td_sigmask, code); 1979 #endif 1980 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1981 ksi, &td->td_sigmask); 1982 postsig_done(sig, td, ps); 1983 mtx_unlock(&ps->ps_mtx); 1984 } else { 1985 /* 1986 * Avoid a possible infinite loop if the thread 1987 * masking the signal or process is ignoring the 1988 * signal. 1989 */ 1990 if (kern_forcesigexit && 1991 (SIGISMEMBER(td->td_sigmask, sig) || 1992 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1993 SIGDELSET(td->td_sigmask, sig); 1994 SIGDELSET(ps->ps_sigcatch, sig); 1995 SIGDELSET(ps->ps_sigignore, sig); 1996 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1997 } 1998 mtx_unlock(&ps->ps_mtx); 1999 p->p_code = code; /* XXX for core dump/debugger */ 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 td->td_dbgflags &= ~TDB_FSTP; 2581 p->p_flag2 &= ~P2_PTRACE_FSTP; 2582 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2583 sig_suspend_threads(td, p, 0); 2584 } 2585 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2586 td->td_dbgflags &= ~TDB_STOPATFORK; 2587 } 2588 stopme: 2589 thread_suspend_switch(td, p); 2590 if (p->p_xthread == td) 2591 p->p_xthread = NULL; 2592 if (!(p->p_flag & P_TRACED)) 2593 break; 2594 if (td->td_dbgflags & TDB_SUSPEND) { 2595 if (p->p_flag & P_SINGLE_EXIT) 2596 break; 2597 goto stopme; 2598 } 2599 } 2600 PROC_SUNLOCK(p); 2601 } 2602 2603 if (si != NULL && sig == td->td_xsig) { 2604 /* Parent wants us to take the original signal unchanged. */ 2605 si->ksi_flags |= KSI_HEAD; 2606 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2607 si->ksi_signo = 0; 2608 } else if (td->td_xsig != 0) { 2609 /* 2610 * If parent wants us to take a new signal, then it will leave 2611 * it in td->td_xsig; otherwise we just look for signals again. 2612 */ 2613 ksiginfo_init(&ksi); 2614 ksi.ksi_signo = td->td_xsig; 2615 ksi.ksi_flags |= KSI_PTRACE; 2616 prop = sigprop(td->td_xsig); 2617 td2 = sigtd(p, td->td_xsig, prop); 2618 tdsendsignal(p, td2, td->td_xsig, &ksi); 2619 if (td != td2) 2620 return (0); 2621 } 2622 2623 return (td->td_xsig); 2624 } 2625 2626 static void 2627 reschedule_signals(struct proc *p, sigset_t block, int flags) 2628 { 2629 struct sigacts *ps; 2630 struct thread *td; 2631 int sig; 2632 2633 PROC_LOCK_ASSERT(p, MA_OWNED); 2634 ps = p->p_sigacts; 2635 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2636 MA_OWNED : MA_NOTOWNED); 2637 if (SIGISEMPTY(p->p_siglist)) 2638 return; 2639 SIGSETAND(block, p->p_siglist); 2640 while ((sig = sig_ffs(&block)) != 0) { 2641 SIGDELSET(block, sig); 2642 td = sigtd(p, sig, 0); 2643 signotify(td); 2644 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2645 mtx_lock(&ps->ps_mtx); 2646 if (p->p_flag & P_TRACED || 2647 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2648 !SIGISMEMBER(td->td_sigmask, sig))) 2649 tdsigwakeup(td, sig, SIG_CATCH, 2650 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2651 ERESTART)); 2652 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2653 mtx_unlock(&ps->ps_mtx); 2654 } 2655 } 2656 2657 void 2658 tdsigcleanup(struct thread *td) 2659 { 2660 struct proc *p; 2661 sigset_t unblocked; 2662 2663 p = td->td_proc; 2664 PROC_LOCK_ASSERT(p, MA_OWNED); 2665 2666 sigqueue_flush(&td->td_sigqueue); 2667 if (p->p_numthreads == 1) 2668 return; 2669 2670 /* 2671 * Since we cannot handle signals, notify signal post code 2672 * about this by filling the sigmask. 2673 * 2674 * Also, if needed, wake up thread(s) that do not block the 2675 * same signals as the exiting thread, since the thread might 2676 * have been selected for delivery and woken up. 2677 */ 2678 SIGFILLSET(unblocked); 2679 SIGSETNAND(unblocked, td->td_sigmask); 2680 SIGFILLSET(td->td_sigmask); 2681 reschedule_signals(p, unblocked, 0); 2682 2683 } 2684 2685 static int 2686 sigdeferstop_curr_flags(int cflags) 2687 { 2688 2689 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2690 (cflags & TDF_SBDRY) != 0); 2691 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2692 } 2693 2694 /* 2695 * Defer the delivery of SIGSTOP for the current thread, according to 2696 * the requested mode. Returns previous flags, which must be restored 2697 * by sigallowstop(). 2698 * 2699 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2700 * cleared by the current thread, which allow the lock-less read-only 2701 * accesses below. 2702 */ 2703 int 2704 sigdeferstop_impl(int mode) 2705 { 2706 struct thread *td; 2707 int cflags, nflags; 2708 2709 td = curthread; 2710 cflags = sigdeferstop_curr_flags(td->td_flags); 2711 switch (mode) { 2712 case SIGDEFERSTOP_NOP: 2713 nflags = cflags; 2714 break; 2715 case SIGDEFERSTOP_OFF: 2716 nflags = 0; 2717 break; 2718 case SIGDEFERSTOP_SILENT: 2719 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2720 break; 2721 case SIGDEFERSTOP_EINTR: 2722 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2723 break; 2724 case SIGDEFERSTOP_ERESTART: 2725 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2726 break; 2727 default: 2728 panic("sigdeferstop: invalid mode %x", mode); 2729 break; 2730 } 2731 if (cflags == nflags) 2732 return (SIGDEFERSTOP_VAL_NCHG); 2733 thread_lock(td); 2734 td->td_flags = (td->td_flags & ~cflags) | nflags; 2735 thread_unlock(td); 2736 return (cflags); 2737 } 2738 2739 /* 2740 * Restores the STOP handling mode, typically permitting the delivery 2741 * of SIGSTOP for the current thread. This does not immediately 2742 * suspend if a stop was posted. Instead, the thread will suspend 2743 * either via ast() or a subsequent interruptible sleep. 2744 */ 2745 void 2746 sigallowstop_impl(int prev) 2747 { 2748 struct thread *td; 2749 int cflags; 2750 2751 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2752 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2753 ("sigallowstop: incorrect previous mode %x", prev)); 2754 td = curthread; 2755 cflags = sigdeferstop_curr_flags(td->td_flags); 2756 if (cflags != prev) { 2757 thread_lock(td); 2758 td->td_flags = (td->td_flags & ~cflags) | prev; 2759 thread_unlock(td); 2760 } 2761 } 2762 2763 /* 2764 * If the current process has received a signal (should be caught or cause 2765 * termination, should interrupt current syscall), return the signal number. 2766 * Stop signals with default action are processed immediately, then cleared; 2767 * they aren't returned. This is checked after each entry to the system for 2768 * a syscall or trap (though this can usually be done without calling issignal 2769 * by checking the pending signal masks in cursig.) The normal call 2770 * sequence is 2771 * 2772 * while (sig = cursig(curthread)) 2773 * postsig(sig); 2774 */ 2775 static int 2776 issignal(struct thread *td) 2777 { 2778 struct proc *p; 2779 struct sigacts *ps; 2780 struct sigqueue *queue; 2781 sigset_t sigpending; 2782 ksiginfo_t ksi; 2783 int prop, sig, traced; 2784 2785 p = td->td_proc; 2786 ps = p->p_sigacts; 2787 mtx_assert(&ps->ps_mtx, MA_OWNED); 2788 PROC_LOCK_ASSERT(p, MA_OWNED); 2789 for (;;) { 2790 traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2791 2792 sigpending = td->td_sigqueue.sq_signals; 2793 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2794 SIGSETNAND(sigpending, td->td_sigmask); 2795 2796 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2797 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2798 SIG_STOPSIGMASK(sigpending); 2799 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2800 return (0); 2801 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2802 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2803 SIGISMEMBER(sigpending, SIGSTOP)) { 2804 /* 2805 * If debugger just attached, always consume 2806 * SIGSTOP from ptrace(PT_ATTACH) first, to 2807 * execute the debugger attach ritual in 2808 * order. 2809 */ 2810 sig = SIGSTOP; 2811 td->td_dbgflags |= TDB_FSTP; 2812 } else { 2813 sig = sig_ffs(&sigpending); 2814 } 2815 2816 if (p->p_stops & S_SIG) { 2817 mtx_unlock(&ps->ps_mtx); 2818 stopevent(p, S_SIG, sig); 2819 mtx_lock(&ps->ps_mtx); 2820 } 2821 2822 /* 2823 * We should see pending but ignored signals 2824 * only if P_TRACED was on when they were posted. 2825 */ 2826 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2827 sigqueue_delete(&td->td_sigqueue, sig); 2828 sigqueue_delete(&p->p_sigqueue, sig); 2829 continue; 2830 } 2831 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2832 /* 2833 * If traced, always stop. 2834 * Remove old signal from queue before the stop. 2835 * XXX shrug off debugger, it causes siginfo to 2836 * be thrown away. 2837 */ 2838 queue = &td->td_sigqueue; 2839 ksiginfo_init(&ksi); 2840 if (sigqueue_get(queue, sig, &ksi) == 0) { 2841 queue = &p->p_sigqueue; 2842 sigqueue_get(queue, sig, &ksi); 2843 } 2844 td->td_si = ksi.ksi_info; 2845 2846 mtx_unlock(&ps->ps_mtx); 2847 sig = ptracestop(td, sig, &ksi); 2848 mtx_lock(&ps->ps_mtx); 2849 2850 td->td_si.si_signo = 0; 2851 2852 /* 2853 * Keep looking if the debugger discarded or 2854 * replaced the signal. 2855 */ 2856 if (sig == 0) 2857 continue; 2858 2859 /* 2860 * If the signal became masked, re-queue it. 2861 */ 2862 if (SIGISMEMBER(td->td_sigmask, sig)) { 2863 ksi.ksi_flags |= KSI_HEAD; 2864 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2865 continue; 2866 } 2867 2868 /* 2869 * If the traced bit got turned off, requeue 2870 * the signal and go back up to the top to 2871 * rescan signals. This ensures that p_sig* 2872 * and p_sigact are consistent. 2873 */ 2874 if ((p->p_flag & P_TRACED) == 0) { 2875 ksi.ksi_flags |= KSI_HEAD; 2876 sigqueue_add(queue, sig, &ksi); 2877 continue; 2878 } 2879 } 2880 2881 prop = sigprop(sig); 2882 2883 /* 2884 * Decide whether the signal should be returned. 2885 * Return the signal's number, or fall through 2886 * to clear it from the pending mask. 2887 */ 2888 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2889 2890 case (intptr_t)SIG_DFL: 2891 /* 2892 * Don't take default actions on system processes. 2893 */ 2894 if (p->p_pid <= 1) { 2895 #ifdef DIAGNOSTIC 2896 /* 2897 * Are you sure you want to ignore SIGSEGV 2898 * in init? XXX 2899 */ 2900 printf("Process (pid %lu) got signal %d\n", 2901 (u_long)p->p_pid, sig); 2902 #endif 2903 break; /* == ignore */ 2904 } 2905 /* 2906 * If there is a pending stop signal to process with 2907 * default action, stop here, then clear the signal. 2908 * Traced or exiting processes should ignore stops. 2909 * Additionally, a member of an orphaned process group 2910 * should ignore tty stops. 2911 */ 2912 if (prop & SIGPROP_STOP) { 2913 if (p->p_flag & 2914 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 2915 (p->p_pgrp->pg_jobc == 0 && 2916 prop & SIGPROP_TTYSTOP)) 2917 break; /* == ignore */ 2918 if (TD_SBDRY_INTR(td)) { 2919 KASSERT((td->td_flags & TDF_SBDRY) != 0, 2920 ("lost TDF_SBDRY")); 2921 return (-1); 2922 } 2923 mtx_unlock(&ps->ps_mtx); 2924 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2925 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2926 sigqueue_delete(&td->td_sigqueue, sig); 2927 sigqueue_delete(&p->p_sigqueue, sig); 2928 p->p_flag |= P_STOPPED_SIG; 2929 p->p_xsig = sig; 2930 PROC_SLOCK(p); 2931 sig_suspend_threads(td, p, 0); 2932 thread_suspend_switch(td, p); 2933 PROC_SUNLOCK(p); 2934 mtx_lock(&ps->ps_mtx); 2935 goto next; 2936 } else if (prop & SIGPROP_IGNORE) { 2937 /* 2938 * Except for SIGCONT, shouldn't get here. 2939 * Default action is to ignore; drop it. 2940 */ 2941 break; /* == ignore */ 2942 } else 2943 return (sig); 2944 /*NOTREACHED*/ 2945 2946 case (intptr_t)SIG_IGN: 2947 /* 2948 * Masking above should prevent us ever trying 2949 * to take action on an ignored signal other 2950 * than SIGCONT, unless process is traced. 2951 */ 2952 if ((prop & SIGPROP_CONT) == 0 && 2953 (p->p_flag & P_TRACED) == 0) 2954 printf("issignal\n"); 2955 break; /* == ignore */ 2956 2957 default: 2958 /* 2959 * This signal has an action, let 2960 * postsig() process it. 2961 */ 2962 return (sig); 2963 } 2964 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2965 sigqueue_delete(&p->p_sigqueue, sig); 2966 next:; 2967 } 2968 /* NOTREACHED */ 2969 } 2970 2971 void 2972 thread_stopped(struct proc *p) 2973 { 2974 int n; 2975 2976 PROC_LOCK_ASSERT(p, MA_OWNED); 2977 PROC_SLOCK_ASSERT(p, MA_OWNED); 2978 n = p->p_suspcount; 2979 if (p == curproc) 2980 n++; 2981 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2982 PROC_SUNLOCK(p); 2983 p->p_flag &= ~P_WAITED; 2984 PROC_LOCK(p->p_pptr); 2985 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2986 CLD_TRAPPED : CLD_STOPPED); 2987 PROC_UNLOCK(p->p_pptr); 2988 PROC_SLOCK(p); 2989 } 2990 } 2991 2992 /* 2993 * Take the action for the specified signal 2994 * from the current set of pending signals. 2995 */ 2996 int 2997 postsig(int sig) 2998 { 2999 struct thread *td; 3000 struct proc *p; 3001 struct sigacts *ps; 3002 sig_t action; 3003 ksiginfo_t ksi; 3004 sigset_t returnmask; 3005 3006 KASSERT(sig != 0, ("postsig")); 3007 3008 td = curthread; 3009 p = td->td_proc; 3010 PROC_LOCK_ASSERT(p, MA_OWNED); 3011 ps = p->p_sigacts; 3012 mtx_assert(&ps->ps_mtx, MA_OWNED); 3013 ksiginfo_init(&ksi); 3014 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3015 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3016 return (0); 3017 ksi.ksi_signo = sig; 3018 if (ksi.ksi_code == SI_TIMER) 3019 itimer_accept(p, ksi.ksi_timerid, &ksi); 3020 action = ps->ps_sigact[_SIG_IDX(sig)]; 3021 #ifdef KTRACE 3022 if (KTRPOINT(td, KTR_PSIG)) 3023 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3024 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3025 #endif 3026 if ((p->p_stops & S_SIG) != 0) { 3027 mtx_unlock(&ps->ps_mtx); 3028 stopevent(p, S_SIG, sig); 3029 mtx_lock(&ps->ps_mtx); 3030 } 3031 3032 if (action == SIG_DFL) { 3033 /* 3034 * Default action, where the default is to kill 3035 * the process. (Other cases were ignored above.) 3036 */ 3037 mtx_unlock(&ps->ps_mtx); 3038 proc_td_siginfo_capture(td, &ksi.ksi_info); 3039 sigexit(td, sig); 3040 /* NOTREACHED */ 3041 } else { 3042 /* 3043 * If we get here, the signal must be caught. 3044 */ 3045 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3046 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3047 ("postsig action: blocked sig %d", sig)); 3048 3049 /* 3050 * Set the new mask value and also defer further 3051 * occurrences of this signal. 3052 * 3053 * Special case: user has done a sigsuspend. Here the 3054 * current mask is not of interest, but rather the 3055 * mask from before the sigsuspend is what we want 3056 * restored after the signal processing is completed. 3057 */ 3058 if (td->td_pflags & TDP_OLDMASK) { 3059 returnmask = td->td_oldsigmask; 3060 td->td_pflags &= ~TDP_OLDMASK; 3061 } else 3062 returnmask = td->td_sigmask; 3063 3064 if (p->p_sig == sig) { 3065 p->p_code = 0; 3066 p->p_sig = 0; 3067 } 3068 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3069 postsig_done(sig, td, ps); 3070 } 3071 return (1); 3072 } 3073 3074 void 3075 proc_wkilled(struct proc *p) 3076 { 3077 3078 PROC_LOCK_ASSERT(p, MA_OWNED); 3079 if ((p->p_flag & P_WKILLED) == 0) { 3080 p->p_flag |= P_WKILLED; 3081 /* 3082 * Notify swapper that there is a process to swap in. 3083 * The notification is racy, at worst it would take 10 3084 * seconds for the swapper process to notice. 3085 */ 3086 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3087 wakeup(&proc0); 3088 } 3089 } 3090 3091 /* 3092 * Kill the current process for stated reason. 3093 */ 3094 void 3095 killproc(struct proc *p, char *why) 3096 { 3097 3098 PROC_LOCK_ASSERT(p, MA_OWNED); 3099 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3100 p->p_comm); 3101 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3102 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3103 p->p_ucred->cr_uid, why); 3104 proc_wkilled(p); 3105 kern_psignal(p, SIGKILL); 3106 } 3107 3108 /* 3109 * Force the current process to exit with the specified signal, dumping core 3110 * if appropriate. We bypass the normal tests for masked and caught signals, 3111 * allowing unrecoverable failures to terminate the process without changing 3112 * signal state. Mark the accounting record with the signal termination. 3113 * If dumping core, save the signal number for the debugger. Calls exit and 3114 * does not return. 3115 */ 3116 void 3117 sigexit(struct thread *td, int sig) 3118 { 3119 struct proc *p = td->td_proc; 3120 3121 PROC_LOCK_ASSERT(p, MA_OWNED); 3122 p->p_acflag |= AXSIG; 3123 /* 3124 * We must be single-threading to generate a core dump. This 3125 * ensures that the registers in the core file are up-to-date. 3126 * Also, the ELF dump handler assumes that the thread list doesn't 3127 * change out from under it. 3128 * 3129 * XXX If another thread attempts to single-thread before us 3130 * (e.g. via fork()), we won't get a dump at all. 3131 */ 3132 if ((sigprop(sig) & SIGPROP_CORE) && 3133 thread_single(p, SINGLE_NO_EXIT) == 0) { 3134 p->p_sig = sig; 3135 /* 3136 * Log signals which would cause core dumps 3137 * (Log as LOG_INFO to appease those who don't want 3138 * these messages.) 3139 * XXX : Todo, as well as euid, write out ruid too 3140 * Note that coredump() drops proc lock. 3141 */ 3142 if (coredump(td) == 0) 3143 sig |= WCOREFLAG; 3144 if (kern_logsigexit) 3145 log(LOG_INFO, 3146 "pid %d (%s), jid %d, uid %d: exited on " 3147 "signal %d%s\n", p->p_pid, p->p_comm, 3148 p->p_ucred->cr_prison->pr_id, 3149 td->td_ucred->cr_uid, 3150 sig &~ WCOREFLAG, 3151 sig & WCOREFLAG ? " (core dumped)" : ""); 3152 } else 3153 PROC_UNLOCK(p); 3154 exit1(td, 0, sig); 3155 /* NOTREACHED */ 3156 } 3157 3158 /* 3159 * Send queued SIGCHLD to parent when child process's state 3160 * is changed. 3161 */ 3162 static void 3163 sigparent(struct proc *p, int reason, int status) 3164 { 3165 PROC_LOCK_ASSERT(p, MA_OWNED); 3166 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3167 3168 if (p->p_ksi != NULL) { 3169 p->p_ksi->ksi_signo = SIGCHLD; 3170 p->p_ksi->ksi_code = reason; 3171 p->p_ksi->ksi_status = status; 3172 p->p_ksi->ksi_pid = p->p_pid; 3173 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3174 if (KSI_ONQ(p->p_ksi)) 3175 return; 3176 } 3177 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3178 } 3179 3180 static void 3181 childproc_jobstate(struct proc *p, int reason, int sig) 3182 { 3183 struct sigacts *ps; 3184 3185 PROC_LOCK_ASSERT(p, MA_OWNED); 3186 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3187 3188 /* 3189 * Wake up parent sleeping in kern_wait(), also send 3190 * SIGCHLD to parent, but SIGCHLD does not guarantee 3191 * that parent will awake, because parent may masked 3192 * the signal. 3193 */ 3194 p->p_pptr->p_flag |= P_STATCHILD; 3195 wakeup(p->p_pptr); 3196 3197 ps = p->p_pptr->p_sigacts; 3198 mtx_lock(&ps->ps_mtx); 3199 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3200 mtx_unlock(&ps->ps_mtx); 3201 sigparent(p, reason, sig); 3202 } else 3203 mtx_unlock(&ps->ps_mtx); 3204 } 3205 3206 void 3207 childproc_stopped(struct proc *p, int reason) 3208 { 3209 3210 childproc_jobstate(p, reason, p->p_xsig); 3211 } 3212 3213 void 3214 childproc_continued(struct proc *p) 3215 { 3216 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3217 } 3218 3219 void 3220 childproc_exited(struct proc *p) 3221 { 3222 int reason, status; 3223 3224 if (WCOREDUMP(p->p_xsig)) { 3225 reason = CLD_DUMPED; 3226 status = WTERMSIG(p->p_xsig); 3227 } else if (WIFSIGNALED(p->p_xsig)) { 3228 reason = CLD_KILLED; 3229 status = WTERMSIG(p->p_xsig); 3230 } else { 3231 reason = CLD_EXITED; 3232 status = p->p_xexit; 3233 } 3234 /* 3235 * XXX avoid calling wakeup(p->p_pptr), the work is 3236 * done in exit1(). 3237 */ 3238 sigparent(p, reason, status); 3239 } 3240 3241 #define MAX_NUM_CORE_FILES 100000 3242 #ifndef NUM_CORE_FILES 3243 #define NUM_CORE_FILES 5 3244 #endif 3245 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3246 static int num_cores = NUM_CORE_FILES; 3247 3248 static int 3249 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3250 { 3251 int error; 3252 int new_val; 3253 3254 new_val = num_cores; 3255 error = sysctl_handle_int(oidp, &new_val, 0, req); 3256 if (error != 0 || req->newptr == NULL) 3257 return (error); 3258 if (new_val > MAX_NUM_CORE_FILES) 3259 new_val = MAX_NUM_CORE_FILES; 3260 if (new_val < 0) 3261 new_val = 0; 3262 num_cores = new_val; 3263 return (0); 3264 } 3265 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3266 0, sizeof(int), sysctl_debug_num_cores_check, "I", 3267 "Maximum number of generated process corefiles while using index format"); 3268 3269 #define GZIP_SUFFIX ".gz" 3270 #define ZSTD_SUFFIX ".zst" 3271 3272 int compress_user_cores = 0; 3273 3274 static int 3275 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3276 { 3277 int error, val; 3278 3279 val = compress_user_cores; 3280 error = sysctl_handle_int(oidp, &val, 0, req); 3281 if (error != 0 || req->newptr == NULL) 3282 return (error); 3283 if (val != 0 && !compressor_avail(val)) 3284 return (EINVAL); 3285 compress_user_cores = val; 3286 return (error); 3287 } 3288 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, CTLTYPE_INT | CTLFLAG_RWTUN, 3289 0, sizeof(int), sysctl_compress_user_cores, "I", 3290 "Enable compression of user corefiles (" 3291 __XSTRING(COMPRESS_GZIP) " = gzip, " 3292 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3293 3294 int compress_user_cores_level = 6; 3295 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3296 &compress_user_cores_level, 0, 3297 "Corefile compression level"); 3298 3299 /* 3300 * Protect the access to corefilename[] by allproc_lock. 3301 */ 3302 #define corefilename_lock allproc_lock 3303 3304 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3305 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3306 3307 static int 3308 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3309 { 3310 int error; 3311 3312 sx_xlock(&corefilename_lock); 3313 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3314 req); 3315 sx_xunlock(&corefilename_lock); 3316 3317 return (error); 3318 } 3319 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3320 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3321 "Process corefile name format string"); 3322 3323 static void 3324 vnode_close_locked(struct thread *td, struct vnode *vp) 3325 { 3326 3327 VOP_UNLOCK(vp, 0); 3328 vn_close(vp, FWRITE, td->td_ucred, td); 3329 } 3330 3331 /* 3332 * If the core format has a %I in it, then we need to check 3333 * for existing corefiles before defining a name. 3334 * To do this we iterate over 0..ncores to find a 3335 * non-existing core file name to use. If all core files are 3336 * already used we choose the oldest one. 3337 */ 3338 static int 3339 corefile_open_last(struct thread *td, char *name, int indexpos, 3340 int indexlen, int ncores, struct vnode **vpp) 3341 { 3342 struct vnode *oldvp, *nextvp, *vp; 3343 struct vattr vattr; 3344 struct nameidata nd; 3345 int error, i, flags, oflags, cmode; 3346 char ch; 3347 struct timespec lasttime; 3348 3349 nextvp = oldvp = NULL; 3350 cmode = S_IRUSR | S_IWUSR; 3351 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3352 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3353 3354 for (i = 0; i < ncores; i++) { 3355 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3356 3357 ch = name[indexpos + indexlen]; 3358 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3359 i); 3360 name[indexpos + indexlen] = ch; 3361 3362 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3363 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3364 NULL); 3365 if (error != 0) 3366 break; 3367 3368 vp = nd.ni_vp; 3369 NDFREE(&nd, NDF_ONLY_PNBUF); 3370 if ((flags & O_CREAT) == O_CREAT) { 3371 nextvp = vp; 3372 break; 3373 } 3374 3375 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3376 if (error != 0) { 3377 vnode_close_locked(td, vp); 3378 break; 3379 } 3380 3381 if (oldvp == NULL || 3382 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3383 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3384 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3385 if (oldvp != NULL) 3386 vnode_close_locked(td, oldvp); 3387 oldvp = vp; 3388 lasttime = vattr.va_mtime; 3389 } else { 3390 vnode_close_locked(td, vp); 3391 } 3392 } 3393 3394 if (oldvp != NULL) { 3395 if (nextvp == NULL) 3396 nextvp = oldvp; 3397 else 3398 vnode_close_locked(td, oldvp); 3399 } 3400 if (error != 0) { 3401 if (nextvp != NULL) 3402 vnode_close_locked(td, oldvp); 3403 } else { 3404 *vpp = nextvp; 3405 } 3406 3407 return (error); 3408 } 3409 3410 /* 3411 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3412 * Expand the name described in corefilename, using name, uid, and pid 3413 * and open/create core file. 3414 * corefilename is a printf-like string, with three format specifiers: 3415 * %N name of process ("name") 3416 * %P process id (pid) 3417 * %U user id (uid) 3418 * For example, "%N.core" is the default; they can be disabled completely 3419 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3420 * This is controlled by the sysctl variable kern.corefile (see above). 3421 */ 3422 static int 3423 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3424 int compress, struct vnode **vpp, char **namep) 3425 { 3426 struct sbuf sb; 3427 struct nameidata nd; 3428 const char *format; 3429 char *hostname, *name; 3430 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3431 3432 hostname = NULL; 3433 format = corefilename; 3434 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3435 indexlen = 0; 3436 indexpos = -1; 3437 ncores = num_cores; 3438 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3439 sx_slock(&corefilename_lock); 3440 for (i = 0; format[i] != '\0'; i++) { 3441 switch (format[i]) { 3442 case '%': /* Format character */ 3443 i++; 3444 switch (format[i]) { 3445 case '%': 3446 sbuf_putc(&sb, '%'); 3447 break; 3448 case 'H': /* hostname */ 3449 if (hostname == NULL) { 3450 hostname = malloc(MAXHOSTNAMELEN, 3451 M_TEMP, M_WAITOK); 3452 } 3453 getcredhostname(td->td_ucred, hostname, 3454 MAXHOSTNAMELEN); 3455 sbuf_printf(&sb, "%s", hostname); 3456 break; 3457 case 'I': /* autoincrementing index */ 3458 if (indexpos != -1) { 3459 sbuf_printf(&sb, "%%I"); 3460 break; 3461 } 3462 3463 indexpos = sbuf_len(&sb); 3464 sbuf_printf(&sb, "%u", ncores - 1); 3465 indexlen = sbuf_len(&sb) - indexpos; 3466 break; 3467 case 'N': /* process name */ 3468 sbuf_printf(&sb, "%s", comm); 3469 break; 3470 case 'P': /* process id */ 3471 sbuf_printf(&sb, "%u", pid); 3472 break; 3473 case 'U': /* user id */ 3474 sbuf_printf(&sb, "%u", uid); 3475 break; 3476 default: 3477 log(LOG_ERR, 3478 "Unknown format character %c in " 3479 "corename `%s'\n", format[i], format); 3480 break; 3481 } 3482 break; 3483 default: 3484 sbuf_putc(&sb, format[i]); 3485 break; 3486 } 3487 } 3488 sx_sunlock(&corefilename_lock); 3489 free(hostname, M_TEMP); 3490 if (compress == COMPRESS_GZIP) 3491 sbuf_printf(&sb, GZIP_SUFFIX); 3492 else if (compress == COMPRESS_ZSTD) 3493 sbuf_printf(&sb, ZSTD_SUFFIX); 3494 if (sbuf_error(&sb) != 0) { 3495 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3496 "long\n", (long)pid, comm, (u_long)uid); 3497 sbuf_delete(&sb); 3498 free(name, M_TEMP); 3499 return (ENOMEM); 3500 } 3501 sbuf_finish(&sb); 3502 sbuf_delete(&sb); 3503 3504 if (indexpos != -1) { 3505 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3506 vpp); 3507 if (error != 0) { 3508 log(LOG_ERR, 3509 "pid %d (%s), uid (%u): Path `%s' failed " 3510 "on initial open test, error = %d\n", 3511 pid, comm, uid, name, error); 3512 } 3513 } else { 3514 cmode = S_IRUSR | S_IWUSR; 3515 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3516 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3517 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3518 3519 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3520 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3521 NULL); 3522 if (error == 0) { 3523 *vpp = nd.ni_vp; 3524 NDFREE(&nd, NDF_ONLY_PNBUF); 3525 } 3526 } 3527 3528 if (error != 0) { 3529 #ifdef AUDIT 3530 audit_proc_coredump(td, name, error); 3531 #endif 3532 free(name, M_TEMP); 3533 return (error); 3534 } 3535 *namep = name; 3536 return (0); 3537 } 3538 3539 /* 3540 * Dump a process' core. The main routine does some 3541 * policy checking, and creates the name of the coredump; 3542 * then it passes on a vnode and a size limit to the process-specific 3543 * coredump routine if there is one; if there _is not_ one, it returns 3544 * ENOSYS; otherwise it returns the error from the process-specific routine. 3545 */ 3546 3547 static int 3548 coredump(struct thread *td) 3549 { 3550 struct proc *p = td->td_proc; 3551 struct ucred *cred = td->td_ucred; 3552 struct vnode *vp; 3553 struct flock lf; 3554 struct vattr vattr; 3555 int error, error1, locked; 3556 char *name; /* name of corefile */ 3557 void *rl_cookie; 3558 off_t limit; 3559 char *fullpath, *freepath = NULL; 3560 struct sbuf *sb; 3561 3562 PROC_LOCK_ASSERT(p, MA_OWNED); 3563 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3564 _STOPEVENT(p, S_CORE, 0); 3565 3566 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3567 (p->p_flag2 & P2_NOTRACE) != 0) { 3568 PROC_UNLOCK(p); 3569 return (EFAULT); 3570 } 3571 3572 /* 3573 * Note that the bulk of limit checking is done after 3574 * the corefile is created. The exception is if the limit 3575 * for corefiles is 0, in which case we don't bother 3576 * creating the corefile at all. This layout means that 3577 * a corefile is truncated instead of not being created, 3578 * if it is larger than the limit. 3579 */ 3580 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3581 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3582 PROC_UNLOCK(p); 3583 return (EFBIG); 3584 } 3585 PROC_UNLOCK(p); 3586 3587 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3588 compress_user_cores, &vp, &name); 3589 if (error != 0) 3590 return (error); 3591 3592 /* 3593 * Don't dump to non-regular files or files with links. 3594 * Do not dump into system files. 3595 */ 3596 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3597 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0) { 3598 VOP_UNLOCK(vp, 0); 3599 error = EFAULT; 3600 goto out; 3601 } 3602 3603 VOP_UNLOCK(vp, 0); 3604 3605 /* Postpone other writers, including core dumps of other processes. */ 3606 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3607 3608 lf.l_whence = SEEK_SET; 3609 lf.l_start = 0; 3610 lf.l_len = 0; 3611 lf.l_type = F_WRLCK; 3612 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3613 3614 VATTR_NULL(&vattr); 3615 vattr.va_size = 0; 3616 if (set_core_nodump_flag) 3617 vattr.va_flags = UF_NODUMP; 3618 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3619 VOP_SETATTR(vp, &vattr, cred); 3620 VOP_UNLOCK(vp, 0); 3621 PROC_LOCK(p); 3622 p->p_acflag |= ACORE; 3623 PROC_UNLOCK(p); 3624 3625 if (p->p_sysent->sv_coredump != NULL) { 3626 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3627 } else { 3628 error = ENOSYS; 3629 } 3630 3631 if (locked) { 3632 lf.l_type = F_UNLCK; 3633 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3634 } 3635 vn_rangelock_unlock(vp, rl_cookie); 3636 3637 /* 3638 * Notify the userland helper that a process triggered a core dump. 3639 * This allows the helper to run an automated debugging session. 3640 */ 3641 if (error != 0 || coredump_devctl == 0) 3642 goto out; 3643 sb = sbuf_new_auto(); 3644 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3645 goto out2; 3646 sbuf_printf(sb, "comm=\""); 3647 devctl_safe_quote_sb(sb, fullpath); 3648 free(freepath, M_TEMP); 3649 sbuf_printf(sb, "\" core=\""); 3650 3651 /* 3652 * We can't lookup core file vp directly. When we're replacing a core, and 3653 * other random times, we flush the name cache, so it will fail. Instead, 3654 * if the path of the core is relative, add the current dir in front if it. 3655 */ 3656 if (name[0] != '/') { 3657 fullpath = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 3658 if (kern___getcwd(td, fullpath, UIO_SYSSPACE, MAXPATHLEN, MAXPATHLEN) != 0) { 3659 free(fullpath, M_TEMP); 3660 goto out2; 3661 } 3662 devctl_safe_quote_sb(sb, fullpath); 3663 free(fullpath, M_TEMP); 3664 sbuf_putc(sb, '/'); 3665 } 3666 devctl_safe_quote_sb(sb, name); 3667 sbuf_printf(sb, "\""); 3668 if (sbuf_finish(sb) == 0) 3669 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 3670 out2: 3671 sbuf_delete(sb); 3672 out: 3673 error1 = vn_close(vp, FWRITE, cred, td); 3674 if (error == 0) 3675 error = error1; 3676 #ifdef AUDIT 3677 audit_proc_coredump(td, name, error); 3678 #endif 3679 free(name, M_TEMP); 3680 return (error); 3681 } 3682 3683 /* 3684 * Nonexistent system call-- signal process (may want to handle it). Flag 3685 * error in case process won't see signal immediately (blocked or ignored). 3686 */ 3687 #ifndef _SYS_SYSPROTO_H_ 3688 struct nosys_args { 3689 int dummy; 3690 }; 3691 #endif 3692 /* ARGSUSED */ 3693 int 3694 nosys(struct thread *td, struct nosys_args *args) 3695 { 3696 struct proc *p; 3697 3698 p = td->td_proc; 3699 3700 PROC_LOCK(p); 3701 tdsignal(td, SIGSYS); 3702 PROC_UNLOCK(p); 3703 if (kern_lognosys == 1 || kern_lognosys == 3) { 3704 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3705 td->td_sa.code); 3706 } 3707 if (kern_lognosys == 2 || kern_lognosys == 3) { 3708 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3709 td->td_sa.code); 3710 } 3711 return (ENOSYS); 3712 } 3713 3714 /* 3715 * Send a SIGIO or SIGURG signal to a process or process group using stored 3716 * credentials rather than those of the current process. 3717 */ 3718 void 3719 pgsigio(struct sigio **sigiop, int sig, int checkctty) 3720 { 3721 ksiginfo_t ksi; 3722 struct sigio *sigio; 3723 3724 ksiginfo_init(&ksi); 3725 ksi.ksi_signo = sig; 3726 ksi.ksi_code = SI_KERNEL; 3727 3728 SIGIO_LOCK(); 3729 sigio = *sigiop; 3730 if (sigio == NULL) { 3731 SIGIO_UNLOCK(); 3732 return; 3733 } 3734 if (sigio->sio_pgid > 0) { 3735 PROC_LOCK(sigio->sio_proc); 3736 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3737 kern_psignal(sigio->sio_proc, sig); 3738 PROC_UNLOCK(sigio->sio_proc); 3739 } else if (sigio->sio_pgid < 0) { 3740 struct proc *p; 3741 3742 PGRP_LOCK(sigio->sio_pgrp); 3743 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3744 PROC_LOCK(p); 3745 if (p->p_state == PRS_NORMAL && 3746 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3747 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3748 kern_psignal(p, sig); 3749 PROC_UNLOCK(p); 3750 } 3751 PGRP_UNLOCK(sigio->sio_pgrp); 3752 } 3753 SIGIO_UNLOCK(); 3754 } 3755 3756 static int 3757 filt_sigattach(struct knote *kn) 3758 { 3759 struct proc *p = curproc; 3760 3761 kn->kn_ptr.p_proc = p; 3762 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3763 3764 knlist_add(p->p_klist, kn, 0); 3765 3766 return (0); 3767 } 3768 3769 static void 3770 filt_sigdetach(struct knote *kn) 3771 { 3772 struct proc *p = kn->kn_ptr.p_proc; 3773 3774 knlist_remove(p->p_klist, kn, 0); 3775 } 3776 3777 /* 3778 * signal knotes are shared with proc knotes, so we apply a mask to 3779 * the hint in order to differentiate them from process hints. This 3780 * could be avoided by using a signal-specific knote list, but probably 3781 * isn't worth the trouble. 3782 */ 3783 static int 3784 filt_signal(struct knote *kn, long hint) 3785 { 3786 3787 if (hint & NOTE_SIGNAL) { 3788 hint &= ~NOTE_SIGNAL; 3789 3790 if (kn->kn_id == hint) 3791 kn->kn_data++; 3792 } 3793 return (kn->kn_data != 0); 3794 } 3795 3796 struct sigacts * 3797 sigacts_alloc(void) 3798 { 3799 struct sigacts *ps; 3800 3801 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3802 refcount_init(&ps->ps_refcnt, 1); 3803 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3804 return (ps); 3805 } 3806 3807 void 3808 sigacts_free(struct sigacts *ps) 3809 { 3810 3811 if (refcount_release(&ps->ps_refcnt) == 0) 3812 return; 3813 mtx_destroy(&ps->ps_mtx); 3814 free(ps, M_SUBPROC); 3815 } 3816 3817 struct sigacts * 3818 sigacts_hold(struct sigacts *ps) 3819 { 3820 3821 refcount_acquire(&ps->ps_refcnt); 3822 return (ps); 3823 } 3824 3825 void 3826 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3827 { 3828 3829 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3830 mtx_lock(&src->ps_mtx); 3831 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3832 mtx_unlock(&src->ps_mtx); 3833 } 3834 3835 int 3836 sigacts_shared(struct sigacts *ps) 3837 { 3838 3839 return (ps->ps_refcnt > 1); 3840 } 3841