1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/ctype.h> 46 #include <sys/systm.h> 47 #include <sys/signalvar.h> 48 #include <sys/vnode.h> 49 #include <sys/acct.h> 50 #include <sys/bus.h> 51 #include <sys/capsicum.h> 52 #include <sys/compressor.h> 53 #include <sys/condvar.h> 54 #include <sys/event.h> 55 #include <sys/fcntl.h> 56 #include <sys/imgact.h> 57 #include <sys/kernel.h> 58 #include <sys/ktr.h> 59 #include <sys/ktrace.h> 60 #include <sys/limits.h> 61 #include <sys/lock.h> 62 #include <sys/malloc.h> 63 #include <sys/mutex.h> 64 #include <sys/refcount.h> 65 #include <sys/namei.h> 66 #include <sys/proc.h> 67 #include <sys/procdesc.h> 68 #include <sys/posix4.h> 69 #include <sys/pioctl.h> 70 #include <sys/racct.h> 71 #include <sys/resourcevar.h> 72 #include <sys/sdt.h> 73 #include <sys/sbuf.h> 74 #include <sys/sleepqueue.h> 75 #include <sys/smp.h> 76 #include <sys/stat.h> 77 #include <sys/sx.h> 78 #include <sys/syscallsubr.h> 79 #include <sys/sysctl.h> 80 #include <sys/sysent.h> 81 #include <sys/syslog.h> 82 #include <sys/sysproto.h> 83 #include <sys/timers.h> 84 #include <sys/unistd.h> 85 #include <sys/wait.h> 86 #include <vm/vm.h> 87 #include <vm/vm_extern.h> 88 #include <vm/uma.h> 89 90 #include <sys/jail.h> 91 92 #include <machine/cpu.h> 93 94 #include <security/audit/audit.h> 95 96 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 97 98 SDT_PROVIDER_DECLARE(proc); 99 SDT_PROBE_DEFINE3(proc, , , signal__send, 100 "struct thread *", "struct proc *", "int"); 101 SDT_PROBE_DEFINE2(proc, , , signal__clear, 102 "int", "ksiginfo_t *"); 103 SDT_PROBE_DEFINE3(proc, , , signal__discard, 104 "struct thread *", "struct proc *", "int"); 105 106 static int coredump(struct thread *); 107 static int killpg1(struct thread *td, int sig, int pgid, int all, 108 ksiginfo_t *ksi); 109 static int issignal(struct thread *td); 110 static int sigprop(int sig); 111 static void tdsigwakeup(struct thread *, int, sig_t, int); 112 static int sig_suspend_threads(struct thread *, struct proc *, int); 113 static int filt_sigattach(struct knote *kn); 114 static void filt_sigdetach(struct knote *kn); 115 static int filt_signal(struct knote *kn, long hint); 116 static struct thread *sigtd(struct proc *p, int sig, int prop); 117 static void sigqueue_start(void); 118 119 static uma_zone_t ksiginfo_zone = NULL; 120 struct filterops sig_filtops = { 121 .f_isfd = 0, 122 .f_attach = filt_sigattach, 123 .f_detach = filt_sigdetach, 124 .f_event = filt_signal, 125 }; 126 127 static int kern_logsigexit = 1; 128 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 129 &kern_logsigexit, 0, 130 "Log processes quitting on abnormal signals to syslog(3)"); 131 132 static int kern_forcesigexit = 1; 133 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 134 &kern_forcesigexit, 0, "Force trap signal to be handled"); 135 136 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 137 "POSIX real time signal"); 138 139 static int max_pending_per_proc = 128; 140 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 141 &max_pending_per_proc, 0, "Max pending signals per proc"); 142 143 static int preallocate_siginfo = 1024; 144 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 145 &preallocate_siginfo, 0, "Preallocated signal memory size"); 146 147 static int signal_overflow = 0; 148 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 149 &signal_overflow, 0, "Number of signals overflew"); 150 151 static int signal_alloc_fail = 0; 152 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 153 &signal_alloc_fail, 0, "signals failed to be allocated"); 154 155 static int kern_lognosys = 0; 156 SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 157 "Log invalid syscalls"); 158 159 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 160 161 /* 162 * Policy -- Can ucred cr1 send SIGIO to process cr2? 163 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 164 * in the right situations. 165 */ 166 #define CANSIGIO(cr1, cr2) \ 167 ((cr1)->cr_uid == 0 || \ 168 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 169 (cr1)->cr_uid == (cr2)->cr_ruid || \ 170 (cr1)->cr_ruid == (cr2)->cr_uid || \ 171 (cr1)->cr_uid == (cr2)->cr_uid) 172 173 static int sugid_coredump; 174 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 175 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 176 177 static int capmode_coredump; 178 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 179 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 180 181 static int do_coredump = 1; 182 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 183 &do_coredump, 0, "Enable/Disable coredumps"); 184 185 static int set_core_nodump_flag = 0; 186 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 187 0, "Enable setting the NODUMP flag on coredump files"); 188 189 static int coredump_devctl = 0; 190 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 191 0, "Generate a devctl notification when processes coredump"); 192 193 /* 194 * Signal properties and actions. 195 * The array below categorizes the signals and their default actions 196 * according to the following properties: 197 */ 198 #define SIGPROP_KILL 0x01 /* terminates process by default */ 199 #define SIGPROP_CORE 0x02 /* ditto and coredumps */ 200 #define SIGPROP_STOP 0x04 /* suspend process */ 201 #define SIGPROP_TTYSTOP 0x08 /* ditto, from tty */ 202 #define SIGPROP_IGNORE 0x10 /* ignore by default */ 203 #define SIGPROP_CONT 0x20 /* continue if suspended */ 204 #define SIGPROP_CANTMASK 0x40 /* non-maskable, catchable */ 205 206 static int sigproptbl[NSIG] = { 207 [SIGHUP] = SIGPROP_KILL, 208 [SIGINT] = SIGPROP_KILL, 209 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE, 210 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE, 211 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE, 212 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE, 213 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE, 214 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE, 215 [SIGKILL] = SIGPROP_KILL, 216 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE, 217 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE, 218 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE, 219 [SIGPIPE] = SIGPROP_KILL, 220 [SIGALRM] = SIGPROP_KILL, 221 [SIGTERM] = SIGPROP_KILL, 222 [SIGURG] = SIGPROP_IGNORE, 223 [SIGSTOP] = SIGPROP_STOP, 224 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP, 225 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT, 226 [SIGCHLD] = SIGPROP_IGNORE, 227 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP, 228 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP, 229 [SIGIO] = SIGPROP_IGNORE, 230 [SIGXCPU] = SIGPROP_KILL, 231 [SIGXFSZ] = SIGPROP_KILL, 232 [SIGVTALRM] = SIGPROP_KILL, 233 [SIGPROF] = SIGPROP_KILL, 234 [SIGWINCH] = SIGPROP_IGNORE, 235 [SIGINFO] = SIGPROP_IGNORE, 236 [SIGUSR1] = SIGPROP_KILL, 237 [SIGUSR2] = SIGPROP_KILL, 238 }; 239 240 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 241 242 static void 243 sigqueue_start(void) 244 { 245 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 246 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 247 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 248 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 249 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 250 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 251 } 252 253 ksiginfo_t * 254 ksiginfo_alloc(int wait) 255 { 256 int flags; 257 258 flags = M_ZERO; 259 if (! wait) 260 flags |= M_NOWAIT; 261 if (ksiginfo_zone != NULL) 262 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 263 return (NULL); 264 } 265 266 void 267 ksiginfo_free(ksiginfo_t *ksi) 268 { 269 uma_zfree(ksiginfo_zone, ksi); 270 } 271 272 static __inline int 273 ksiginfo_tryfree(ksiginfo_t *ksi) 274 { 275 if (!(ksi->ksi_flags & KSI_EXT)) { 276 uma_zfree(ksiginfo_zone, ksi); 277 return (1); 278 } 279 return (0); 280 } 281 282 void 283 sigqueue_init(sigqueue_t *list, struct proc *p) 284 { 285 SIGEMPTYSET(list->sq_signals); 286 SIGEMPTYSET(list->sq_kill); 287 SIGEMPTYSET(list->sq_ptrace); 288 TAILQ_INIT(&list->sq_list); 289 list->sq_proc = p; 290 list->sq_flags = SQ_INIT; 291 } 292 293 /* 294 * Get a signal's ksiginfo. 295 * Return: 296 * 0 - signal not found 297 * others - signal number 298 */ 299 static int 300 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 301 { 302 struct proc *p = sq->sq_proc; 303 struct ksiginfo *ksi, *next; 304 int count = 0; 305 306 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 307 308 if (!SIGISMEMBER(sq->sq_signals, signo)) 309 return (0); 310 311 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 312 count++; 313 SIGDELSET(sq->sq_ptrace, signo); 314 si->ksi_flags |= KSI_PTRACE; 315 } 316 if (SIGISMEMBER(sq->sq_kill, signo)) { 317 count++; 318 if (count == 1) 319 SIGDELSET(sq->sq_kill, signo); 320 } 321 322 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 323 if (ksi->ksi_signo == signo) { 324 if (count == 0) { 325 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 326 ksi->ksi_sigq = NULL; 327 ksiginfo_copy(ksi, si); 328 if (ksiginfo_tryfree(ksi) && p != NULL) 329 p->p_pendingcnt--; 330 } 331 if (++count > 1) 332 break; 333 } 334 } 335 336 if (count <= 1) 337 SIGDELSET(sq->sq_signals, signo); 338 si->ksi_signo = signo; 339 return (signo); 340 } 341 342 void 343 sigqueue_take(ksiginfo_t *ksi) 344 { 345 struct ksiginfo *kp; 346 struct proc *p; 347 sigqueue_t *sq; 348 349 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 350 return; 351 352 p = sq->sq_proc; 353 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 354 ksi->ksi_sigq = NULL; 355 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 356 p->p_pendingcnt--; 357 358 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 359 kp = TAILQ_NEXT(kp, ksi_link)) { 360 if (kp->ksi_signo == ksi->ksi_signo) 361 break; 362 } 363 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 364 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 365 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 366 } 367 368 static int 369 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 370 { 371 struct proc *p = sq->sq_proc; 372 struct ksiginfo *ksi; 373 int ret = 0; 374 375 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 376 377 /* 378 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 379 * for these signals. 380 */ 381 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 382 SIGADDSET(sq->sq_kill, signo); 383 goto out_set_bit; 384 } 385 386 /* directly insert the ksi, don't copy it */ 387 if (si->ksi_flags & KSI_INS) { 388 if (si->ksi_flags & KSI_HEAD) 389 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 390 else 391 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 392 si->ksi_sigq = sq; 393 goto out_set_bit; 394 } 395 396 if (__predict_false(ksiginfo_zone == NULL)) { 397 SIGADDSET(sq->sq_kill, signo); 398 goto out_set_bit; 399 } 400 401 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 402 signal_overflow++; 403 ret = EAGAIN; 404 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 405 signal_alloc_fail++; 406 ret = EAGAIN; 407 } else { 408 if (p != NULL) 409 p->p_pendingcnt++; 410 ksiginfo_copy(si, ksi); 411 ksi->ksi_signo = signo; 412 if (si->ksi_flags & KSI_HEAD) 413 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 414 else 415 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 416 ksi->ksi_sigq = sq; 417 } 418 419 if (ret != 0) { 420 if ((si->ksi_flags & KSI_PTRACE) != 0) { 421 SIGADDSET(sq->sq_ptrace, signo); 422 ret = 0; 423 goto out_set_bit; 424 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 425 (si->ksi_flags & KSI_SIGQ) == 0) { 426 SIGADDSET(sq->sq_kill, signo); 427 ret = 0; 428 goto out_set_bit; 429 } 430 return (ret); 431 } 432 433 out_set_bit: 434 SIGADDSET(sq->sq_signals, signo); 435 return (ret); 436 } 437 438 void 439 sigqueue_flush(sigqueue_t *sq) 440 { 441 struct proc *p = sq->sq_proc; 442 ksiginfo_t *ksi; 443 444 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 445 446 if (p != NULL) 447 PROC_LOCK_ASSERT(p, MA_OWNED); 448 449 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 450 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 451 ksi->ksi_sigq = NULL; 452 if (ksiginfo_tryfree(ksi) && p != NULL) 453 p->p_pendingcnt--; 454 } 455 456 SIGEMPTYSET(sq->sq_signals); 457 SIGEMPTYSET(sq->sq_kill); 458 SIGEMPTYSET(sq->sq_ptrace); 459 } 460 461 static void 462 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 463 { 464 sigset_t tmp; 465 struct proc *p1, *p2; 466 ksiginfo_t *ksi, *next; 467 468 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 469 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 470 p1 = src->sq_proc; 471 p2 = dst->sq_proc; 472 /* Move siginfo to target list */ 473 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 474 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 475 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 476 if (p1 != NULL) 477 p1->p_pendingcnt--; 478 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 479 ksi->ksi_sigq = dst; 480 if (p2 != NULL) 481 p2->p_pendingcnt++; 482 } 483 } 484 485 /* Move pending bits to target list */ 486 tmp = src->sq_kill; 487 SIGSETAND(tmp, *set); 488 SIGSETOR(dst->sq_kill, tmp); 489 SIGSETNAND(src->sq_kill, tmp); 490 491 tmp = src->sq_ptrace; 492 SIGSETAND(tmp, *set); 493 SIGSETOR(dst->sq_ptrace, tmp); 494 SIGSETNAND(src->sq_ptrace, tmp); 495 496 tmp = src->sq_signals; 497 SIGSETAND(tmp, *set); 498 SIGSETOR(dst->sq_signals, tmp); 499 SIGSETNAND(src->sq_signals, tmp); 500 } 501 502 #if 0 503 static void 504 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 505 { 506 sigset_t set; 507 508 SIGEMPTYSET(set); 509 SIGADDSET(set, signo); 510 sigqueue_move_set(src, dst, &set); 511 } 512 #endif 513 514 static void 515 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 516 { 517 struct proc *p = sq->sq_proc; 518 ksiginfo_t *ksi, *next; 519 520 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 521 522 /* Remove siginfo queue */ 523 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 524 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 525 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 526 ksi->ksi_sigq = NULL; 527 if (ksiginfo_tryfree(ksi) && p != NULL) 528 p->p_pendingcnt--; 529 } 530 } 531 SIGSETNAND(sq->sq_kill, *set); 532 SIGSETNAND(sq->sq_ptrace, *set); 533 SIGSETNAND(sq->sq_signals, *set); 534 } 535 536 void 537 sigqueue_delete(sigqueue_t *sq, int signo) 538 { 539 sigset_t set; 540 541 SIGEMPTYSET(set); 542 SIGADDSET(set, signo); 543 sigqueue_delete_set(sq, &set); 544 } 545 546 /* Remove a set of signals for a process */ 547 static void 548 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 549 { 550 sigqueue_t worklist; 551 struct thread *td0; 552 553 PROC_LOCK_ASSERT(p, MA_OWNED); 554 555 sigqueue_init(&worklist, NULL); 556 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 557 558 FOREACH_THREAD_IN_PROC(p, td0) 559 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 560 561 sigqueue_flush(&worklist); 562 } 563 564 void 565 sigqueue_delete_proc(struct proc *p, int signo) 566 { 567 sigset_t set; 568 569 SIGEMPTYSET(set); 570 SIGADDSET(set, signo); 571 sigqueue_delete_set_proc(p, &set); 572 } 573 574 static void 575 sigqueue_delete_stopmask_proc(struct proc *p) 576 { 577 sigset_t set; 578 579 SIGEMPTYSET(set); 580 SIGADDSET(set, SIGSTOP); 581 SIGADDSET(set, SIGTSTP); 582 SIGADDSET(set, SIGTTIN); 583 SIGADDSET(set, SIGTTOU); 584 sigqueue_delete_set_proc(p, &set); 585 } 586 587 /* 588 * Determine signal that should be delivered to thread td, the current 589 * thread, 0 if none. If there is a pending stop signal with default 590 * action, the process stops in issignal(). 591 */ 592 int 593 cursig(struct thread *td) 594 { 595 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 596 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 597 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 598 return (SIGPENDING(td) ? issignal(td) : 0); 599 } 600 601 /* 602 * Arrange for ast() to handle unmasked pending signals on return to user 603 * mode. This must be called whenever a signal is added to td_sigqueue or 604 * unmasked in td_sigmask. 605 */ 606 void 607 signotify(struct thread *td) 608 { 609 610 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 611 612 if (SIGPENDING(td)) { 613 thread_lock(td); 614 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 615 thread_unlock(td); 616 } 617 } 618 619 /* 620 * Returns 1 (true) if altstack is configured for the thread, and the 621 * passed stack bottom address falls into the altstack range. Handles 622 * the 43 compat special case where the alt stack size is zero. 623 */ 624 int 625 sigonstack(size_t sp) 626 { 627 struct thread *td; 628 629 td = curthread; 630 if ((td->td_pflags & TDP_ALTSTACK) == 0) 631 return (0); 632 #if defined(COMPAT_43) 633 if (SV_PROC_FLAG(td->td_proc, SV_AOUT) && td->td_sigstk.ss_size == 0) 634 return ((td->td_sigstk.ss_flags & SS_ONSTACK) != 0); 635 #endif 636 return (sp >= (size_t)td->td_sigstk.ss_sp && 637 sp < td->td_sigstk.ss_size + (size_t)td->td_sigstk.ss_sp); 638 } 639 640 static __inline int 641 sigprop(int sig) 642 { 643 644 if (sig > 0 && sig < nitems(sigproptbl)) 645 return (sigproptbl[sig]); 646 return (0); 647 } 648 649 int 650 sig_ffs(sigset_t *set) 651 { 652 int i; 653 654 for (i = 0; i < _SIG_WORDS; i++) 655 if (set->__bits[i]) 656 return (ffs(set->__bits[i]) + (i * 32)); 657 return (0); 658 } 659 660 static bool 661 sigact_flag_test(const struct sigaction *act, int flag) 662 { 663 664 /* 665 * SA_SIGINFO is reset when signal disposition is set to 666 * ignore or default. Other flags are kept according to user 667 * settings. 668 */ 669 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 670 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 671 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 672 } 673 674 /* 675 * kern_sigaction 676 * sigaction 677 * freebsd4_sigaction 678 * osigaction 679 */ 680 int 681 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 682 struct sigaction *oact, int flags) 683 { 684 struct sigacts *ps; 685 struct proc *p = td->td_proc; 686 687 if (!_SIG_VALID(sig)) 688 return (EINVAL); 689 if (act != NULL && act->sa_handler != SIG_DFL && 690 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 691 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 692 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 693 return (EINVAL); 694 695 PROC_LOCK(p); 696 ps = p->p_sigacts; 697 mtx_lock(&ps->ps_mtx); 698 if (oact) { 699 memset(oact, 0, sizeof(*oact)); 700 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 701 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 702 oact->sa_flags |= SA_ONSTACK; 703 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 704 oact->sa_flags |= SA_RESTART; 705 if (SIGISMEMBER(ps->ps_sigreset, sig)) 706 oact->sa_flags |= SA_RESETHAND; 707 if (SIGISMEMBER(ps->ps_signodefer, sig)) 708 oact->sa_flags |= SA_NODEFER; 709 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 710 oact->sa_flags |= SA_SIGINFO; 711 oact->sa_sigaction = 712 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 713 } else 714 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 715 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 716 oact->sa_flags |= SA_NOCLDSTOP; 717 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 718 oact->sa_flags |= SA_NOCLDWAIT; 719 } 720 if (act) { 721 if ((sig == SIGKILL || sig == SIGSTOP) && 722 act->sa_handler != SIG_DFL) { 723 mtx_unlock(&ps->ps_mtx); 724 PROC_UNLOCK(p); 725 return (EINVAL); 726 } 727 728 /* 729 * Change setting atomically. 730 */ 731 732 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 733 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 734 if (sigact_flag_test(act, SA_SIGINFO)) { 735 ps->ps_sigact[_SIG_IDX(sig)] = 736 (__sighandler_t *)act->sa_sigaction; 737 SIGADDSET(ps->ps_siginfo, sig); 738 } else { 739 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 740 SIGDELSET(ps->ps_siginfo, sig); 741 } 742 if (!sigact_flag_test(act, SA_RESTART)) 743 SIGADDSET(ps->ps_sigintr, sig); 744 else 745 SIGDELSET(ps->ps_sigintr, sig); 746 if (sigact_flag_test(act, SA_ONSTACK)) 747 SIGADDSET(ps->ps_sigonstack, sig); 748 else 749 SIGDELSET(ps->ps_sigonstack, sig); 750 if (sigact_flag_test(act, SA_RESETHAND)) 751 SIGADDSET(ps->ps_sigreset, sig); 752 else 753 SIGDELSET(ps->ps_sigreset, sig); 754 if (sigact_flag_test(act, SA_NODEFER)) 755 SIGADDSET(ps->ps_signodefer, sig); 756 else 757 SIGDELSET(ps->ps_signodefer, sig); 758 if (sig == SIGCHLD) { 759 if (act->sa_flags & SA_NOCLDSTOP) 760 ps->ps_flag |= PS_NOCLDSTOP; 761 else 762 ps->ps_flag &= ~PS_NOCLDSTOP; 763 if (act->sa_flags & SA_NOCLDWAIT) { 764 /* 765 * Paranoia: since SA_NOCLDWAIT is implemented 766 * by reparenting the dying child to PID 1 (and 767 * trust it to reap the zombie), PID 1 itself 768 * is forbidden to set SA_NOCLDWAIT. 769 */ 770 if (p->p_pid == 1) 771 ps->ps_flag &= ~PS_NOCLDWAIT; 772 else 773 ps->ps_flag |= PS_NOCLDWAIT; 774 } else 775 ps->ps_flag &= ~PS_NOCLDWAIT; 776 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 777 ps->ps_flag |= PS_CLDSIGIGN; 778 else 779 ps->ps_flag &= ~PS_CLDSIGIGN; 780 } 781 /* 782 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 783 * and for signals set to SIG_DFL where the default is to 784 * ignore. However, don't put SIGCONT in ps_sigignore, as we 785 * have to restart the process. 786 */ 787 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 788 (sigprop(sig) & SIGPROP_IGNORE && 789 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 790 /* never to be seen again */ 791 sigqueue_delete_proc(p, sig); 792 if (sig != SIGCONT) 793 /* easier in psignal */ 794 SIGADDSET(ps->ps_sigignore, sig); 795 SIGDELSET(ps->ps_sigcatch, sig); 796 } else { 797 SIGDELSET(ps->ps_sigignore, sig); 798 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 799 SIGDELSET(ps->ps_sigcatch, sig); 800 else 801 SIGADDSET(ps->ps_sigcatch, sig); 802 } 803 #ifdef COMPAT_FREEBSD4 804 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 805 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 806 (flags & KSA_FREEBSD4) == 0) 807 SIGDELSET(ps->ps_freebsd4, sig); 808 else 809 SIGADDSET(ps->ps_freebsd4, sig); 810 #endif 811 #ifdef COMPAT_43 812 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 813 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 814 (flags & KSA_OSIGSET) == 0) 815 SIGDELSET(ps->ps_osigset, sig); 816 else 817 SIGADDSET(ps->ps_osigset, sig); 818 #endif 819 } 820 mtx_unlock(&ps->ps_mtx); 821 PROC_UNLOCK(p); 822 return (0); 823 } 824 825 #ifndef _SYS_SYSPROTO_H_ 826 struct sigaction_args { 827 int sig; 828 struct sigaction *act; 829 struct sigaction *oact; 830 }; 831 #endif 832 int 833 sys_sigaction(struct thread *td, struct sigaction_args *uap) 834 { 835 struct sigaction act, oact; 836 struct sigaction *actp, *oactp; 837 int error; 838 839 actp = (uap->act != NULL) ? &act : NULL; 840 oactp = (uap->oact != NULL) ? &oact : NULL; 841 if (actp) { 842 error = copyin(uap->act, actp, sizeof(act)); 843 if (error) 844 return (error); 845 } 846 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 847 if (oactp && !error) 848 error = copyout(oactp, uap->oact, sizeof(oact)); 849 return (error); 850 } 851 852 #ifdef COMPAT_FREEBSD4 853 #ifndef _SYS_SYSPROTO_H_ 854 struct freebsd4_sigaction_args { 855 int sig; 856 struct sigaction *act; 857 struct sigaction *oact; 858 }; 859 #endif 860 int 861 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 862 { 863 struct sigaction act, oact; 864 struct sigaction *actp, *oactp; 865 int error; 866 867 868 actp = (uap->act != NULL) ? &act : NULL; 869 oactp = (uap->oact != NULL) ? &oact : NULL; 870 if (actp) { 871 error = copyin(uap->act, actp, sizeof(act)); 872 if (error) 873 return (error); 874 } 875 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 876 if (oactp && !error) 877 error = copyout(oactp, uap->oact, sizeof(oact)); 878 return (error); 879 } 880 #endif /* COMAPT_FREEBSD4 */ 881 882 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 883 #ifndef _SYS_SYSPROTO_H_ 884 struct osigaction_args { 885 int signum; 886 struct osigaction *nsa; 887 struct osigaction *osa; 888 }; 889 #endif 890 int 891 osigaction(struct thread *td, struct osigaction_args *uap) 892 { 893 struct osigaction sa; 894 struct sigaction nsa, osa; 895 struct sigaction *nsap, *osap; 896 int error; 897 898 if (uap->signum <= 0 || uap->signum >= ONSIG) 899 return (EINVAL); 900 901 nsap = (uap->nsa != NULL) ? &nsa : NULL; 902 osap = (uap->osa != NULL) ? &osa : NULL; 903 904 if (nsap) { 905 error = copyin(uap->nsa, &sa, sizeof(sa)); 906 if (error) 907 return (error); 908 nsap->sa_handler = sa.sa_handler; 909 nsap->sa_flags = sa.sa_flags; 910 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 911 } 912 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 913 if (osap && !error) { 914 sa.sa_handler = osap->sa_handler; 915 sa.sa_flags = osap->sa_flags; 916 SIG2OSIG(osap->sa_mask, sa.sa_mask); 917 error = copyout(&sa, uap->osa, sizeof(sa)); 918 } 919 return (error); 920 } 921 922 #if !defined(__i386__) 923 /* Avoid replicating the same stub everywhere */ 924 int 925 osigreturn(struct thread *td, struct osigreturn_args *uap) 926 { 927 928 return (nosys(td, (struct nosys_args *)uap)); 929 } 930 #endif 931 #endif /* COMPAT_43 */ 932 933 /* 934 * Initialize signal state for process 0; 935 * set to ignore signals that are ignored by default. 936 */ 937 void 938 siginit(struct proc *p) 939 { 940 int i; 941 struct sigacts *ps; 942 943 PROC_LOCK(p); 944 ps = p->p_sigacts; 945 mtx_lock(&ps->ps_mtx); 946 for (i = 1; i <= NSIG; i++) { 947 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 948 SIGADDSET(ps->ps_sigignore, i); 949 } 950 } 951 mtx_unlock(&ps->ps_mtx); 952 PROC_UNLOCK(p); 953 } 954 955 /* 956 * Reset specified signal to the default disposition. 957 */ 958 static void 959 sigdflt(struct sigacts *ps, int sig) 960 { 961 962 mtx_assert(&ps->ps_mtx, MA_OWNED); 963 SIGDELSET(ps->ps_sigcatch, sig); 964 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 965 SIGADDSET(ps->ps_sigignore, sig); 966 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 967 SIGDELSET(ps->ps_siginfo, sig); 968 } 969 970 /* 971 * Reset signals for an exec of the specified process. 972 */ 973 void 974 execsigs(struct proc *p) 975 { 976 sigset_t osigignore; 977 struct sigacts *ps; 978 int sig; 979 struct thread *td; 980 981 /* 982 * Reset caught signals. Held signals remain held 983 * through td_sigmask (unless they were caught, 984 * and are now ignored by default). 985 */ 986 PROC_LOCK_ASSERT(p, MA_OWNED); 987 ps = p->p_sigacts; 988 mtx_lock(&ps->ps_mtx); 989 sig_drop_caught(p); 990 991 /* 992 * As CloudABI processes cannot modify signal handlers, fully 993 * reset all signals to their default behavior. Do ignore 994 * SIGPIPE, as it would otherwise be impossible to recover from 995 * writes to broken pipes and sockets. 996 */ 997 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 998 osigignore = ps->ps_sigignore; 999 while (SIGNOTEMPTY(osigignore)) { 1000 sig = sig_ffs(&osigignore); 1001 SIGDELSET(osigignore, sig); 1002 if (sig != SIGPIPE) 1003 sigdflt(ps, sig); 1004 } 1005 SIGADDSET(ps->ps_sigignore, SIGPIPE); 1006 } 1007 1008 /* 1009 * Reset stack state to the user stack. 1010 * Clear set of signals caught on the signal stack. 1011 */ 1012 td = curthread; 1013 MPASS(td->td_proc == p); 1014 td->td_sigstk.ss_flags = SS_DISABLE; 1015 td->td_sigstk.ss_size = 0; 1016 td->td_sigstk.ss_sp = 0; 1017 td->td_pflags &= ~TDP_ALTSTACK; 1018 /* 1019 * Reset no zombies if child dies flag as Solaris does. 1020 */ 1021 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1022 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1023 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1024 mtx_unlock(&ps->ps_mtx); 1025 } 1026 1027 /* 1028 * kern_sigprocmask() 1029 * 1030 * Manipulate signal mask. 1031 */ 1032 int 1033 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1034 int flags) 1035 { 1036 sigset_t new_block, oset1; 1037 struct proc *p; 1038 int error; 1039 1040 p = td->td_proc; 1041 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1042 PROC_LOCK_ASSERT(p, MA_OWNED); 1043 else 1044 PROC_LOCK(p); 1045 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1046 ? MA_OWNED : MA_NOTOWNED); 1047 if (oset != NULL) 1048 *oset = td->td_sigmask; 1049 1050 error = 0; 1051 if (set != NULL) { 1052 switch (how) { 1053 case SIG_BLOCK: 1054 SIG_CANTMASK(*set); 1055 oset1 = td->td_sigmask; 1056 SIGSETOR(td->td_sigmask, *set); 1057 new_block = td->td_sigmask; 1058 SIGSETNAND(new_block, oset1); 1059 break; 1060 case SIG_UNBLOCK: 1061 SIGSETNAND(td->td_sigmask, *set); 1062 signotify(td); 1063 goto out; 1064 case SIG_SETMASK: 1065 SIG_CANTMASK(*set); 1066 oset1 = td->td_sigmask; 1067 if (flags & SIGPROCMASK_OLD) 1068 SIGSETLO(td->td_sigmask, *set); 1069 else 1070 td->td_sigmask = *set; 1071 new_block = td->td_sigmask; 1072 SIGSETNAND(new_block, oset1); 1073 signotify(td); 1074 break; 1075 default: 1076 error = EINVAL; 1077 goto out; 1078 } 1079 1080 /* 1081 * The new_block set contains signals that were not previously 1082 * blocked, but are blocked now. 1083 * 1084 * In case we block any signal that was not previously blocked 1085 * for td, and process has the signal pending, try to schedule 1086 * signal delivery to some thread that does not block the 1087 * signal, possibly waking it up. 1088 */ 1089 if (p->p_numthreads != 1) 1090 reschedule_signals(p, new_block, flags); 1091 } 1092 1093 out: 1094 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1095 PROC_UNLOCK(p); 1096 return (error); 1097 } 1098 1099 #ifndef _SYS_SYSPROTO_H_ 1100 struct sigprocmask_args { 1101 int how; 1102 const sigset_t *set; 1103 sigset_t *oset; 1104 }; 1105 #endif 1106 int 1107 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1108 { 1109 sigset_t set, oset; 1110 sigset_t *setp, *osetp; 1111 int error; 1112 1113 setp = (uap->set != NULL) ? &set : NULL; 1114 osetp = (uap->oset != NULL) ? &oset : NULL; 1115 if (setp) { 1116 error = copyin(uap->set, setp, sizeof(set)); 1117 if (error) 1118 return (error); 1119 } 1120 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1121 if (osetp && !error) { 1122 error = copyout(osetp, uap->oset, sizeof(oset)); 1123 } 1124 return (error); 1125 } 1126 1127 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1128 #ifndef _SYS_SYSPROTO_H_ 1129 struct osigprocmask_args { 1130 int how; 1131 osigset_t mask; 1132 }; 1133 #endif 1134 int 1135 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1136 { 1137 sigset_t set, oset; 1138 int error; 1139 1140 OSIG2SIG(uap->mask, set); 1141 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1142 SIG2OSIG(oset, td->td_retval[0]); 1143 return (error); 1144 } 1145 #endif /* COMPAT_43 */ 1146 1147 int 1148 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1149 { 1150 ksiginfo_t ksi; 1151 sigset_t set; 1152 int error; 1153 1154 error = copyin(uap->set, &set, sizeof(set)); 1155 if (error) { 1156 td->td_retval[0] = error; 1157 return (0); 1158 } 1159 1160 error = kern_sigtimedwait(td, set, &ksi, NULL); 1161 if (error) { 1162 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1163 error = ERESTART; 1164 if (error == ERESTART) 1165 return (error); 1166 td->td_retval[0] = error; 1167 return (0); 1168 } 1169 1170 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1171 td->td_retval[0] = error; 1172 return (0); 1173 } 1174 1175 int 1176 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1177 { 1178 struct timespec ts; 1179 struct timespec *timeout; 1180 sigset_t set; 1181 ksiginfo_t ksi; 1182 int error; 1183 1184 if (uap->timeout) { 1185 error = copyin(uap->timeout, &ts, sizeof(ts)); 1186 if (error) 1187 return (error); 1188 1189 timeout = &ts; 1190 } else 1191 timeout = NULL; 1192 1193 error = copyin(uap->set, &set, sizeof(set)); 1194 if (error) 1195 return (error); 1196 1197 error = kern_sigtimedwait(td, set, &ksi, timeout); 1198 if (error) 1199 return (error); 1200 1201 if (uap->info) 1202 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1203 1204 if (error == 0) 1205 td->td_retval[0] = ksi.ksi_signo; 1206 return (error); 1207 } 1208 1209 int 1210 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1211 { 1212 ksiginfo_t ksi; 1213 sigset_t set; 1214 int error; 1215 1216 error = copyin(uap->set, &set, sizeof(set)); 1217 if (error) 1218 return (error); 1219 1220 error = kern_sigtimedwait(td, set, &ksi, NULL); 1221 if (error) 1222 return (error); 1223 1224 if (uap->info) 1225 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1226 1227 if (error == 0) 1228 td->td_retval[0] = ksi.ksi_signo; 1229 return (error); 1230 } 1231 1232 static void 1233 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1234 { 1235 struct thread *thr; 1236 1237 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1238 if (thr == td) 1239 thr->td_si = *si; 1240 else 1241 thr->td_si.si_signo = 0; 1242 } 1243 } 1244 1245 int 1246 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1247 struct timespec *timeout) 1248 { 1249 struct sigacts *ps; 1250 sigset_t saved_mask, new_block; 1251 struct proc *p; 1252 int error, sig, timo, timevalid = 0; 1253 struct timespec rts, ets, ts; 1254 struct timeval tv; 1255 1256 p = td->td_proc; 1257 error = 0; 1258 ets.tv_sec = 0; 1259 ets.tv_nsec = 0; 1260 1261 if (timeout != NULL) { 1262 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1263 timevalid = 1; 1264 getnanouptime(&rts); 1265 timespecadd(&rts, timeout, &ets); 1266 } 1267 } 1268 ksiginfo_init(ksi); 1269 /* Some signals can not be waited for. */ 1270 SIG_CANTMASK(waitset); 1271 ps = p->p_sigacts; 1272 PROC_LOCK(p); 1273 saved_mask = td->td_sigmask; 1274 SIGSETNAND(td->td_sigmask, waitset); 1275 for (;;) { 1276 mtx_lock(&ps->ps_mtx); 1277 sig = cursig(td); 1278 mtx_unlock(&ps->ps_mtx); 1279 KASSERT(sig >= 0, ("sig %d", sig)); 1280 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1281 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1282 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1283 error = 0; 1284 break; 1285 } 1286 } 1287 1288 if (error != 0) 1289 break; 1290 1291 /* 1292 * POSIX says this must be checked after looking for pending 1293 * signals. 1294 */ 1295 if (timeout != NULL) { 1296 if (!timevalid) { 1297 error = EINVAL; 1298 break; 1299 } 1300 getnanouptime(&rts); 1301 if (timespeccmp(&rts, &ets, >=)) { 1302 error = EAGAIN; 1303 break; 1304 } 1305 timespecsub(&ets, &rts, &ts); 1306 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1307 timo = tvtohz(&tv); 1308 } else { 1309 timo = 0; 1310 } 1311 1312 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1313 1314 if (timeout != NULL) { 1315 if (error == ERESTART) { 1316 /* Timeout can not be restarted. */ 1317 error = EINTR; 1318 } else if (error == EAGAIN) { 1319 /* We will calculate timeout by ourself. */ 1320 error = 0; 1321 } 1322 } 1323 } 1324 1325 new_block = saved_mask; 1326 SIGSETNAND(new_block, td->td_sigmask); 1327 td->td_sigmask = saved_mask; 1328 /* 1329 * Fewer signals can be delivered to us, reschedule signal 1330 * notification. 1331 */ 1332 if (p->p_numthreads != 1) 1333 reschedule_signals(p, new_block, 0); 1334 1335 if (error == 0) { 1336 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1337 1338 if (ksi->ksi_code == SI_TIMER) 1339 itimer_accept(p, ksi->ksi_timerid, ksi); 1340 1341 #ifdef KTRACE 1342 if (KTRPOINT(td, KTR_PSIG)) { 1343 sig_t action; 1344 1345 mtx_lock(&ps->ps_mtx); 1346 action = ps->ps_sigact[_SIG_IDX(sig)]; 1347 mtx_unlock(&ps->ps_mtx); 1348 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1349 } 1350 #endif 1351 if (sig == SIGKILL) { 1352 proc_td_siginfo_capture(td, &ksi->ksi_info); 1353 sigexit(td, sig); 1354 } 1355 } 1356 PROC_UNLOCK(p); 1357 return (error); 1358 } 1359 1360 #ifndef _SYS_SYSPROTO_H_ 1361 struct sigpending_args { 1362 sigset_t *set; 1363 }; 1364 #endif 1365 int 1366 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1367 { 1368 struct proc *p = td->td_proc; 1369 sigset_t pending; 1370 1371 PROC_LOCK(p); 1372 pending = p->p_sigqueue.sq_signals; 1373 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1374 PROC_UNLOCK(p); 1375 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1376 } 1377 1378 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1379 #ifndef _SYS_SYSPROTO_H_ 1380 struct osigpending_args { 1381 int dummy; 1382 }; 1383 #endif 1384 int 1385 osigpending(struct thread *td, struct osigpending_args *uap) 1386 { 1387 struct proc *p = td->td_proc; 1388 sigset_t pending; 1389 1390 PROC_LOCK(p); 1391 pending = p->p_sigqueue.sq_signals; 1392 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1393 PROC_UNLOCK(p); 1394 SIG2OSIG(pending, td->td_retval[0]); 1395 return (0); 1396 } 1397 #endif /* COMPAT_43 */ 1398 1399 #if defined(COMPAT_43) 1400 /* 1401 * Generalized interface signal handler, 4.3-compatible. 1402 */ 1403 #ifndef _SYS_SYSPROTO_H_ 1404 struct osigvec_args { 1405 int signum; 1406 struct sigvec *nsv; 1407 struct sigvec *osv; 1408 }; 1409 #endif 1410 /* ARGSUSED */ 1411 int 1412 osigvec(struct thread *td, struct osigvec_args *uap) 1413 { 1414 struct sigvec vec; 1415 struct sigaction nsa, osa; 1416 struct sigaction *nsap, *osap; 1417 int error; 1418 1419 if (uap->signum <= 0 || uap->signum >= ONSIG) 1420 return (EINVAL); 1421 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1422 osap = (uap->osv != NULL) ? &osa : NULL; 1423 if (nsap) { 1424 error = copyin(uap->nsv, &vec, sizeof(vec)); 1425 if (error) 1426 return (error); 1427 nsap->sa_handler = vec.sv_handler; 1428 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1429 nsap->sa_flags = vec.sv_flags; 1430 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1431 } 1432 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1433 if (osap && !error) { 1434 vec.sv_handler = osap->sa_handler; 1435 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1436 vec.sv_flags = osap->sa_flags; 1437 vec.sv_flags &= ~SA_NOCLDWAIT; 1438 vec.sv_flags ^= SA_RESTART; 1439 error = copyout(&vec, uap->osv, sizeof(vec)); 1440 } 1441 return (error); 1442 } 1443 1444 #ifndef _SYS_SYSPROTO_H_ 1445 struct osigblock_args { 1446 int mask; 1447 }; 1448 #endif 1449 int 1450 osigblock(struct thread *td, struct osigblock_args *uap) 1451 { 1452 sigset_t set, oset; 1453 1454 OSIG2SIG(uap->mask, set); 1455 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1456 SIG2OSIG(oset, td->td_retval[0]); 1457 return (0); 1458 } 1459 1460 #ifndef _SYS_SYSPROTO_H_ 1461 struct osigsetmask_args { 1462 int mask; 1463 }; 1464 #endif 1465 int 1466 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1467 { 1468 sigset_t set, oset; 1469 1470 OSIG2SIG(uap->mask, set); 1471 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1472 SIG2OSIG(oset, td->td_retval[0]); 1473 return (0); 1474 } 1475 #endif /* COMPAT_43 */ 1476 1477 /* 1478 * Suspend calling thread until signal, providing mask to be set in the 1479 * meantime. 1480 */ 1481 #ifndef _SYS_SYSPROTO_H_ 1482 struct sigsuspend_args { 1483 const sigset_t *sigmask; 1484 }; 1485 #endif 1486 /* ARGSUSED */ 1487 int 1488 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1489 { 1490 sigset_t mask; 1491 int error; 1492 1493 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1494 if (error) 1495 return (error); 1496 return (kern_sigsuspend(td, mask)); 1497 } 1498 1499 int 1500 kern_sigsuspend(struct thread *td, sigset_t mask) 1501 { 1502 struct proc *p = td->td_proc; 1503 int has_sig, sig; 1504 1505 /* 1506 * When returning from sigsuspend, we want 1507 * the old mask to be restored after the 1508 * signal handler has finished. Thus, we 1509 * save it here and mark the sigacts structure 1510 * to indicate this. 1511 */ 1512 PROC_LOCK(p); 1513 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1514 SIGPROCMASK_PROC_LOCKED); 1515 td->td_pflags |= TDP_OLDMASK; 1516 1517 /* 1518 * Process signals now. Otherwise, we can get spurious wakeup 1519 * due to signal entered process queue, but delivered to other 1520 * thread. But sigsuspend should return only on signal 1521 * delivery. 1522 */ 1523 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1524 for (has_sig = 0; !has_sig;) { 1525 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1526 0) == 0) 1527 /* void */; 1528 thread_suspend_check(0); 1529 mtx_lock(&p->p_sigacts->ps_mtx); 1530 while ((sig = cursig(td)) != 0) { 1531 KASSERT(sig >= 0, ("sig %d", sig)); 1532 has_sig += postsig(sig); 1533 } 1534 mtx_unlock(&p->p_sigacts->ps_mtx); 1535 } 1536 PROC_UNLOCK(p); 1537 td->td_errno = EINTR; 1538 td->td_pflags |= TDP_NERRNO; 1539 return (EJUSTRETURN); 1540 } 1541 1542 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1543 /* 1544 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1545 * convention: libc stub passes mask, not pointer, to save a copyin. 1546 */ 1547 #ifndef _SYS_SYSPROTO_H_ 1548 struct osigsuspend_args { 1549 osigset_t mask; 1550 }; 1551 #endif 1552 /* ARGSUSED */ 1553 int 1554 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1555 { 1556 sigset_t mask; 1557 1558 OSIG2SIG(uap->mask, mask); 1559 return (kern_sigsuspend(td, mask)); 1560 } 1561 #endif /* COMPAT_43 */ 1562 1563 #if defined(COMPAT_43) 1564 #ifndef _SYS_SYSPROTO_H_ 1565 struct osigstack_args { 1566 struct sigstack *nss; 1567 struct sigstack *oss; 1568 }; 1569 #endif 1570 /* ARGSUSED */ 1571 int 1572 osigstack(struct thread *td, struct osigstack_args *uap) 1573 { 1574 struct sigstack nss, oss; 1575 int error = 0; 1576 1577 if (uap->nss != NULL) { 1578 error = copyin(uap->nss, &nss, sizeof(nss)); 1579 if (error) 1580 return (error); 1581 } 1582 oss.ss_sp = td->td_sigstk.ss_sp; 1583 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1584 if (uap->nss != NULL) { 1585 td->td_sigstk.ss_sp = nss.ss_sp; 1586 td->td_sigstk.ss_size = 0; 1587 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1588 td->td_pflags |= TDP_ALTSTACK; 1589 } 1590 if (uap->oss != NULL) 1591 error = copyout(&oss, uap->oss, sizeof(oss)); 1592 1593 return (error); 1594 } 1595 #endif /* COMPAT_43 */ 1596 1597 #ifndef _SYS_SYSPROTO_H_ 1598 struct sigaltstack_args { 1599 stack_t *ss; 1600 stack_t *oss; 1601 }; 1602 #endif 1603 /* ARGSUSED */ 1604 int 1605 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1606 { 1607 stack_t ss, oss; 1608 int error; 1609 1610 if (uap->ss != NULL) { 1611 error = copyin(uap->ss, &ss, sizeof(ss)); 1612 if (error) 1613 return (error); 1614 } 1615 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1616 (uap->oss != NULL) ? &oss : NULL); 1617 if (error) 1618 return (error); 1619 if (uap->oss != NULL) 1620 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1621 return (error); 1622 } 1623 1624 int 1625 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1626 { 1627 struct proc *p = td->td_proc; 1628 int oonstack; 1629 1630 oonstack = sigonstack(cpu_getstack(td)); 1631 1632 if (oss != NULL) { 1633 *oss = td->td_sigstk; 1634 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1635 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1636 } 1637 1638 if (ss != NULL) { 1639 if (oonstack) 1640 return (EPERM); 1641 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1642 return (EINVAL); 1643 if (!(ss->ss_flags & SS_DISABLE)) { 1644 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1645 return (ENOMEM); 1646 1647 td->td_sigstk = *ss; 1648 td->td_pflags |= TDP_ALTSTACK; 1649 } else { 1650 td->td_pflags &= ~TDP_ALTSTACK; 1651 } 1652 } 1653 return (0); 1654 } 1655 1656 /* 1657 * Common code for kill process group/broadcast kill. 1658 * cp is calling process. 1659 */ 1660 static int 1661 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1662 { 1663 struct proc *p; 1664 struct pgrp *pgrp; 1665 int err; 1666 int ret; 1667 1668 ret = ESRCH; 1669 if (all) { 1670 /* 1671 * broadcast 1672 */ 1673 sx_slock(&allproc_lock); 1674 FOREACH_PROC_IN_SYSTEM(p) { 1675 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1676 p == td->td_proc || p->p_state == PRS_NEW) { 1677 continue; 1678 } 1679 PROC_LOCK(p); 1680 err = p_cansignal(td, p, sig); 1681 if (err == 0) { 1682 if (sig) 1683 pksignal(p, sig, ksi); 1684 ret = err; 1685 } 1686 else if (ret == ESRCH) 1687 ret = err; 1688 PROC_UNLOCK(p); 1689 } 1690 sx_sunlock(&allproc_lock); 1691 } else { 1692 sx_slock(&proctree_lock); 1693 if (pgid == 0) { 1694 /* 1695 * zero pgid means send to my process group. 1696 */ 1697 pgrp = td->td_proc->p_pgrp; 1698 PGRP_LOCK(pgrp); 1699 } else { 1700 pgrp = pgfind(pgid); 1701 if (pgrp == NULL) { 1702 sx_sunlock(&proctree_lock); 1703 return (ESRCH); 1704 } 1705 } 1706 sx_sunlock(&proctree_lock); 1707 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1708 PROC_LOCK(p); 1709 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1710 p->p_state == PRS_NEW) { 1711 PROC_UNLOCK(p); 1712 continue; 1713 } 1714 err = p_cansignal(td, p, sig); 1715 if (err == 0) { 1716 if (sig) 1717 pksignal(p, sig, ksi); 1718 ret = err; 1719 } 1720 else if (ret == ESRCH) 1721 ret = err; 1722 PROC_UNLOCK(p); 1723 } 1724 PGRP_UNLOCK(pgrp); 1725 } 1726 return (ret); 1727 } 1728 1729 #ifndef _SYS_SYSPROTO_H_ 1730 struct kill_args { 1731 int pid; 1732 int signum; 1733 }; 1734 #endif 1735 /* ARGSUSED */ 1736 int 1737 sys_kill(struct thread *td, struct kill_args *uap) 1738 { 1739 ksiginfo_t ksi; 1740 struct proc *p; 1741 int error; 1742 1743 /* 1744 * A process in capability mode can send signals only to himself. 1745 * The main rationale behind this is that abort(3) is implemented as 1746 * kill(getpid(), SIGABRT). 1747 */ 1748 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1749 return (ECAPMODE); 1750 1751 AUDIT_ARG_SIGNUM(uap->signum); 1752 AUDIT_ARG_PID(uap->pid); 1753 if ((u_int)uap->signum > _SIG_MAXSIG) 1754 return (EINVAL); 1755 1756 ksiginfo_init(&ksi); 1757 ksi.ksi_signo = uap->signum; 1758 ksi.ksi_code = SI_USER; 1759 ksi.ksi_pid = td->td_proc->p_pid; 1760 ksi.ksi_uid = td->td_ucred->cr_ruid; 1761 1762 if (uap->pid > 0) { 1763 /* kill single process */ 1764 if ((p = pfind_any(uap->pid)) == NULL) 1765 return (ESRCH); 1766 AUDIT_ARG_PROCESS(p); 1767 error = p_cansignal(td, p, uap->signum); 1768 if (error == 0 && uap->signum) 1769 pksignal(p, uap->signum, &ksi); 1770 PROC_UNLOCK(p); 1771 return (error); 1772 } 1773 switch (uap->pid) { 1774 case -1: /* broadcast signal */ 1775 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1776 case 0: /* signal own process group */ 1777 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1778 default: /* negative explicit process group */ 1779 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1780 } 1781 /* NOTREACHED */ 1782 } 1783 1784 int 1785 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1786 { 1787 struct proc *p; 1788 int error; 1789 1790 AUDIT_ARG_SIGNUM(uap->signum); 1791 AUDIT_ARG_FD(uap->fd); 1792 if ((u_int)uap->signum > _SIG_MAXSIG) 1793 return (EINVAL); 1794 1795 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1796 if (error) 1797 return (error); 1798 AUDIT_ARG_PROCESS(p); 1799 error = p_cansignal(td, p, uap->signum); 1800 if (error == 0 && uap->signum) 1801 kern_psignal(p, uap->signum); 1802 PROC_UNLOCK(p); 1803 return (error); 1804 } 1805 1806 #if defined(COMPAT_43) 1807 #ifndef _SYS_SYSPROTO_H_ 1808 struct okillpg_args { 1809 int pgid; 1810 int signum; 1811 }; 1812 #endif 1813 /* ARGSUSED */ 1814 int 1815 okillpg(struct thread *td, struct okillpg_args *uap) 1816 { 1817 ksiginfo_t ksi; 1818 1819 AUDIT_ARG_SIGNUM(uap->signum); 1820 AUDIT_ARG_PID(uap->pgid); 1821 if ((u_int)uap->signum > _SIG_MAXSIG) 1822 return (EINVAL); 1823 1824 ksiginfo_init(&ksi); 1825 ksi.ksi_signo = uap->signum; 1826 ksi.ksi_code = SI_USER; 1827 ksi.ksi_pid = td->td_proc->p_pid; 1828 ksi.ksi_uid = td->td_ucred->cr_ruid; 1829 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1830 } 1831 #endif /* COMPAT_43 */ 1832 1833 #ifndef _SYS_SYSPROTO_H_ 1834 struct sigqueue_args { 1835 pid_t pid; 1836 int signum; 1837 /* union sigval */ void *value; 1838 }; 1839 #endif 1840 int 1841 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1842 { 1843 union sigval sv; 1844 1845 sv.sival_ptr = uap->value; 1846 1847 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1848 } 1849 1850 int 1851 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1852 { 1853 ksiginfo_t ksi; 1854 struct proc *p; 1855 int error; 1856 1857 if ((u_int)signum > _SIG_MAXSIG) 1858 return (EINVAL); 1859 1860 /* 1861 * Specification says sigqueue can only send signal to 1862 * single process. 1863 */ 1864 if (pid <= 0) 1865 return (EINVAL); 1866 1867 if ((p = pfind_any(pid)) == NULL) 1868 return (ESRCH); 1869 error = p_cansignal(td, p, signum); 1870 if (error == 0 && signum != 0) { 1871 ksiginfo_init(&ksi); 1872 ksi.ksi_flags = KSI_SIGQ; 1873 ksi.ksi_signo = signum; 1874 ksi.ksi_code = SI_QUEUE; 1875 ksi.ksi_pid = td->td_proc->p_pid; 1876 ksi.ksi_uid = td->td_ucred->cr_ruid; 1877 ksi.ksi_value = *value; 1878 error = pksignal(p, ksi.ksi_signo, &ksi); 1879 } 1880 PROC_UNLOCK(p); 1881 return (error); 1882 } 1883 1884 /* 1885 * Send a signal to a process group. 1886 */ 1887 void 1888 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1889 { 1890 struct pgrp *pgrp; 1891 1892 if (pgid != 0) { 1893 sx_slock(&proctree_lock); 1894 pgrp = pgfind(pgid); 1895 sx_sunlock(&proctree_lock); 1896 if (pgrp != NULL) { 1897 pgsignal(pgrp, sig, 0, ksi); 1898 PGRP_UNLOCK(pgrp); 1899 } 1900 } 1901 } 1902 1903 /* 1904 * Send a signal to a process group. If checktty is 1, 1905 * limit to members which have a controlling terminal. 1906 */ 1907 void 1908 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1909 { 1910 struct proc *p; 1911 1912 if (pgrp) { 1913 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1914 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1915 PROC_LOCK(p); 1916 if (p->p_state == PRS_NORMAL && 1917 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1918 pksignal(p, sig, ksi); 1919 PROC_UNLOCK(p); 1920 } 1921 } 1922 } 1923 1924 1925 /* 1926 * Recalculate the signal mask and reset the signal disposition after 1927 * usermode frame for delivery is formed. Should be called after 1928 * mach-specific routine, because sysent->sv_sendsig() needs correct 1929 * ps_siginfo and signal mask. 1930 */ 1931 static void 1932 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1933 { 1934 sigset_t mask; 1935 1936 mtx_assert(&ps->ps_mtx, MA_OWNED); 1937 td->td_ru.ru_nsignals++; 1938 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1939 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1940 SIGADDSET(mask, sig); 1941 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1942 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1943 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1944 sigdflt(ps, sig); 1945 } 1946 1947 1948 /* 1949 * Send a signal caused by a trap to the current thread. If it will be 1950 * caught immediately, deliver it with correct code. Otherwise, post it 1951 * normally. 1952 */ 1953 void 1954 trapsignal(struct thread *td, ksiginfo_t *ksi) 1955 { 1956 struct sigacts *ps; 1957 struct proc *p; 1958 int sig; 1959 int code; 1960 1961 p = td->td_proc; 1962 sig = ksi->ksi_signo; 1963 code = ksi->ksi_code; 1964 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1965 1966 PROC_LOCK(p); 1967 ps = p->p_sigacts; 1968 mtx_lock(&ps->ps_mtx); 1969 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1970 !SIGISMEMBER(td->td_sigmask, sig)) { 1971 #ifdef KTRACE 1972 if (KTRPOINT(curthread, KTR_PSIG)) 1973 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1974 &td->td_sigmask, code); 1975 #endif 1976 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1977 ksi, &td->td_sigmask); 1978 postsig_done(sig, td, ps); 1979 mtx_unlock(&ps->ps_mtx); 1980 } else { 1981 /* 1982 * Avoid a possible infinite loop if the thread 1983 * masking the signal or process is ignoring the 1984 * signal. 1985 */ 1986 if (kern_forcesigexit && 1987 (SIGISMEMBER(td->td_sigmask, sig) || 1988 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1989 SIGDELSET(td->td_sigmask, sig); 1990 SIGDELSET(ps->ps_sigcatch, sig); 1991 SIGDELSET(ps->ps_sigignore, sig); 1992 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1993 } 1994 mtx_unlock(&ps->ps_mtx); 1995 p->p_sig = sig; /* XXX to verify code */ 1996 tdsendsignal(p, td, sig, ksi); 1997 } 1998 PROC_UNLOCK(p); 1999 } 2000 2001 static struct thread * 2002 sigtd(struct proc *p, int sig, int prop) 2003 { 2004 struct thread *td, *signal_td; 2005 2006 PROC_LOCK_ASSERT(p, MA_OWNED); 2007 2008 /* 2009 * Check if current thread can handle the signal without 2010 * switching context to another thread. 2011 */ 2012 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2013 return (curthread); 2014 signal_td = NULL; 2015 FOREACH_THREAD_IN_PROC(p, td) { 2016 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2017 signal_td = td; 2018 break; 2019 } 2020 } 2021 if (signal_td == NULL) 2022 signal_td = FIRST_THREAD_IN_PROC(p); 2023 return (signal_td); 2024 } 2025 2026 /* 2027 * Send the signal to the process. If the signal has an action, the action 2028 * is usually performed by the target process rather than the caller; we add 2029 * the signal to the set of pending signals for the process. 2030 * 2031 * Exceptions: 2032 * o When a stop signal is sent to a sleeping process that takes the 2033 * default action, the process is stopped without awakening it. 2034 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2035 * regardless of the signal action (eg, blocked or ignored). 2036 * 2037 * Other ignored signals are discarded immediately. 2038 * 2039 * NB: This function may be entered from the debugger via the "kill" DDB 2040 * command. There is little that can be done to mitigate the possibly messy 2041 * side effects of this unwise possibility. 2042 */ 2043 void 2044 kern_psignal(struct proc *p, int sig) 2045 { 2046 ksiginfo_t ksi; 2047 2048 ksiginfo_init(&ksi); 2049 ksi.ksi_signo = sig; 2050 ksi.ksi_code = SI_KERNEL; 2051 (void) tdsendsignal(p, NULL, sig, &ksi); 2052 } 2053 2054 int 2055 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2056 { 2057 2058 return (tdsendsignal(p, NULL, sig, ksi)); 2059 } 2060 2061 /* Utility function for finding a thread to send signal event to. */ 2062 int 2063 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2064 { 2065 struct thread *td; 2066 2067 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2068 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2069 if (td == NULL) 2070 return (ESRCH); 2071 *ttd = td; 2072 } else { 2073 *ttd = NULL; 2074 PROC_LOCK(p); 2075 } 2076 return (0); 2077 } 2078 2079 void 2080 tdsignal(struct thread *td, int sig) 2081 { 2082 ksiginfo_t ksi; 2083 2084 ksiginfo_init(&ksi); 2085 ksi.ksi_signo = sig; 2086 ksi.ksi_code = SI_KERNEL; 2087 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2088 } 2089 2090 void 2091 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2092 { 2093 2094 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2095 } 2096 2097 int 2098 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2099 { 2100 sig_t action; 2101 sigqueue_t *sigqueue; 2102 int prop; 2103 struct sigacts *ps; 2104 int intrval; 2105 int ret = 0; 2106 int wakeup_swapper; 2107 2108 MPASS(td == NULL || p == td->td_proc); 2109 PROC_LOCK_ASSERT(p, MA_OWNED); 2110 2111 if (!_SIG_VALID(sig)) 2112 panic("%s(): invalid signal %d", __func__, sig); 2113 2114 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2115 2116 /* 2117 * IEEE Std 1003.1-2001: return success when killing a zombie. 2118 */ 2119 if (p->p_state == PRS_ZOMBIE) { 2120 if (ksi && (ksi->ksi_flags & KSI_INS)) 2121 ksiginfo_tryfree(ksi); 2122 return (ret); 2123 } 2124 2125 ps = p->p_sigacts; 2126 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2127 prop = sigprop(sig); 2128 2129 if (td == NULL) { 2130 td = sigtd(p, sig, prop); 2131 sigqueue = &p->p_sigqueue; 2132 } else 2133 sigqueue = &td->td_sigqueue; 2134 2135 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2136 2137 /* 2138 * If the signal is being ignored, 2139 * then we forget about it immediately. 2140 * (Note: we don't set SIGCONT in ps_sigignore, 2141 * and if it is set to SIG_IGN, 2142 * action will be SIG_DFL here.) 2143 */ 2144 mtx_lock(&ps->ps_mtx); 2145 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2146 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2147 2148 mtx_unlock(&ps->ps_mtx); 2149 if (ksi && (ksi->ksi_flags & KSI_INS)) 2150 ksiginfo_tryfree(ksi); 2151 return (ret); 2152 } 2153 if (SIGISMEMBER(td->td_sigmask, sig)) 2154 action = SIG_HOLD; 2155 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2156 action = SIG_CATCH; 2157 else 2158 action = SIG_DFL; 2159 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2160 intrval = EINTR; 2161 else 2162 intrval = ERESTART; 2163 mtx_unlock(&ps->ps_mtx); 2164 2165 if (prop & SIGPROP_CONT) 2166 sigqueue_delete_stopmask_proc(p); 2167 else if (prop & SIGPROP_STOP) { 2168 /* 2169 * If sending a tty stop signal to a member of an orphaned 2170 * process group, discard the signal here if the action 2171 * is default; don't stop the process below if sleeping, 2172 * and don't clear any pending SIGCONT. 2173 */ 2174 if ((prop & SIGPROP_TTYSTOP) && 2175 (p->p_pgrp->pg_jobc == 0) && 2176 (action == SIG_DFL)) { 2177 if (ksi && (ksi->ksi_flags & KSI_INS)) 2178 ksiginfo_tryfree(ksi); 2179 return (ret); 2180 } 2181 sigqueue_delete_proc(p, SIGCONT); 2182 if (p->p_flag & P_CONTINUED) { 2183 p->p_flag &= ~P_CONTINUED; 2184 PROC_LOCK(p->p_pptr); 2185 sigqueue_take(p->p_ksi); 2186 PROC_UNLOCK(p->p_pptr); 2187 } 2188 } 2189 2190 ret = sigqueue_add(sigqueue, sig, ksi); 2191 if (ret != 0) 2192 return (ret); 2193 signotify(td); 2194 /* 2195 * Defer further processing for signals which are held, 2196 * except that stopped processes must be continued by SIGCONT. 2197 */ 2198 if (action == SIG_HOLD && 2199 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2200 return (ret); 2201 2202 /* SIGKILL: Remove procfs STOPEVENTs. */ 2203 if (sig == SIGKILL) { 2204 /* from procfs_ioctl.c: PIOCBIC */ 2205 p->p_stops = 0; 2206 /* from procfs_ioctl.c: PIOCCONT */ 2207 p->p_step = 0; 2208 wakeup(&p->p_step); 2209 } 2210 /* 2211 * Some signals have a process-wide effect and a per-thread 2212 * component. Most processing occurs when the process next 2213 * tries to cross the user boundary, however there are some 2214 * times when processing needs to be done immediately, such as 2215 * waking up threads so that they can cross the user boundary. 2216 * We try to do the per-process part here. 2217 */ 2218 if (P_SHOULDSTOP(p)) { 2219 KASSERT(!(p->p_flag & P_WEXIT), 2220 ("signal to stopped but exiting process")); 2221 if (sig == SIGKILL) { 2222 /* 2223 * If traced process is already stopped, 2224 * then no further action is necessary. 2225 */ 2226 if (p->p_flag & P_TRACED) 2227 goto out; 2228 /* 2229 * SIGKILL sets process running. 2230 * It will die elsewhere. 2231 * All threads must be restarted. 2232 */ 2233 p->p_flag &= ~P_STOPPED_SIG; 2234 goto runfast; 2235 } 2236 2237 if (prop & SIGPROP_CONT) { 2238 /* 2239 * If traced process is already stopped, 2240 * then no further action is necessary. 2241 */ 2242 if (p->p_flag & P_TRACED) 2243 goto out; 2244 /* 2245 * If SIGCONT is default (or ignored), we continue the 2246 * process but don't leave the signal in sigqueue as 2247 * it has no further action. If SIGCONT is held, we 2248 * continue the process and leave the signal in 2249 * sigqueue. If the process catches SIGCONT, let it 2250 * handle the signal itself. If it isn't waiting on 2251 * an event, it goes back to run state. 2252 * Otherwise, process goes back to sleep state. 2253 */ 2254 p->p_flag &= ~P_STOPPED_SIG; 2255 PROC_SLOCK(p); 2256 if (p->p_numthreads == p->p_suspcount) { 2257 PROC_SUNLOCK(p); 2258 p->p_flag |= P_CONTINUED; 2259 p->p_xsig = SIGCONT; 2260 PROC_LOCK(p->p_pptr); 2261 childproc_continued(p); 2262 PROC_UNLOCK(p->p_pptr); 2263 PROC_SLOCK(p); 2264 } 2265 if (action == SIG_DFL) { 2266 thread_unsuspend(p); 2267 PROC_SUNLOCK(p); 2268 sigqueue_delete(sigqueue, sig); 2269 goto out; 2270 } 2271 if (action == SIG_CATCH) { 2272 /* 2273 * The process wants to catch it so it needs 2274 * to run at least one thread, but which one? 2275 */ 2276 PROC_SUNLOCK(p); 2277 goto runfast; 2278 } 2279 /* 2280 * The signal is not ignored or caught. 2281 */ 2282 thread_unsuspend(p); 2283 PROC_SUNLOCK(p); 2284 goto out; 2285 } 2286 2287 if (prop & SIGPROP_STOP) { 2288 /* 2289 * If traced process is already stopped, 2290 * then no further action is necessary. 2291 */ 2292 if (p->p_flag & P_TRACED) 2293 goto out; 2294 /* 2295 * Already stopped, don't need to stop again 2296 * (If we did the shell could get confused). 2297 * Just make sure the signal STOP bit set. 2298 */ 2299 p->p_flag |= P_STOPPED_SIG; 2300 sigqueue_delete(sigqueue, sig); 2301 goto out; 2302 } 2303 2304 /* 2305 * All other kinds of signals: 2306 * If a thread is sleeping interruptibly, simulate a 2307 * wakeup so that when it is continued it will be made 2308 * runnable and can look at the signal. However, don't make 2309 * the PROCESS runnable, leave it stopped. 2310 * It may run a bit until it hits a thread_suspend_check(). 2311 */ 2312 wakeup_swapper = 0; 2313 PROC_SLOCK(p); 2314 thread_lock(td); 2315 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2316 wakeup_swapper = sleepq_abort(td, intrval); 2317 thread_unlock(td); 2318 PROC_SUNLOCK(p); 2319 if (wakeup_swapper) 2320 kick_proc0(); 2321 goto out; 2322 /* 2323 * Mutexes are short lived. Threads waiting on them will 2324 * hit thread_suspend_check() soon. 2325 */ 2326 } else if (p->p_state == PRS_NORMAL) { 2327 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2328 tdsigwakeup(td, sig, action, intrval); 2329 goto out; 2330 } 2331 2332 MPASS(action == SIG_DFL); 2333 2334 if (prop & SIGPROP_STOP) { 2335 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2336 goto out; 2337 p->p_flag |= P_STOPPED_SIG; 2338 p->p_xsig = sig; 2339 PROC_SLOCK(p); 2340 wakeup_swapper = sig_suspend_threads(td, p, 1); 2341 if (p->p_numthreads == p->p_suspcount) { 2342 /* 2343 * only thread sending signal to another 2344 * process can reach here, if thread is sending 2345 * signal to its process, because thread does 2346 * not suspend itself here, p_numthreads 2347 * should never be equal to p_suspcount. 2348 */ 2349 thread_stopped(p); 2350 PROC_SUNLOCK(p); 2351 sigqueue_delete_proc(p, p->p_xsig); 2352 } else 2353 PROC_SUNLOCK(p); 2354 if (wakeup_swapper) 2355 kick_proc0(); 2356 goto out; 2357 } 2358 } else { 2359 /* Not in "NORMAL" state. discard the signal. */ 2360 sigqueue_delete(sigqueue, sig); 2361 goto out; 2362 } 2363 2364 /* 2365 * The process is not stopped so we need to apply the signal to all the 2366 * running threads. 2367 */ 2368 runfast: 2369 tdsigwakeup(td, sig, action, intrval); 2370 PROC_SLOCK(p); 2371 thread_unsuspend(p); 2372 PROC_SUNLOCK(p); 2373 out: 2374 /* If we jump here, proc slock should not be owned. */ 2375 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2376 return (ret); 2377 } 2378 2379 /* 2380 * The force of a signal has been directed against a single 2381 * thread. We need to see what we can do about knocking it 2382 * out of any sleep it may be in etc. 2383 */ 2384 static void 2385 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2386 { 2387 struct proc *p = td->td_proc; 2388 int prop; 2389 int wakeup_swapper; 2390 2391 wakeup_swapper = 0; 2392 PROC_LOCK_ASSERT(p, MA_OWNED); 2393 prop = sigprop(sig); 2394 2395 PROC_SLOCK(p); 2396 thread_lock(td); 2397 /* 2398 * Bring the priority of a thread up if we want it to get 2399 * killed in this lifetime. Be careful to avoid bumping the 2400 * priority of the idle thread, since we still allow to signal 2401 * kernel processes. 2402 */ 2403 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2404 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2405 sched_prio(td, PUSER); 2406 if (TD_ON_SLEEPQ(td)) { 2407 /* 2408 * If thread is sleeping uninterruptibly 2409 * we can't interrupt the sleep... the signal will 2410 * be noticed when the process returns through 2411 * trap() or syscall(). 2412 */ 2413 if ((td->td_flags & TDF_SINTR) == 0) 2414 goto out; 2415 /* 2416 * If SIGCONT is default (or ignored) and process is 2417 * asleep, we are finished; the process should not 2418 * be awakened. 2419 */ 2420 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2421 thread_unlock(td); 2422 PROC_SUNLOCK(p); 2423 sigqueue_delete(&p->p_sigqueue, sig); 2424 /* 2425 * It may be on either list in this state. 2426 * Remove from both for now. 2427 */ 2428 sigqueue_delete(&td->td_sigqueue, sig); 2429 return; 2430 } 2431 2432 /* 2433 * Don't awaken a sleeping thread for SIGSTOP if the 2434 * STOP signal is deferred. 2435 */ 2436 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2437 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2438 goto out; 2439 2440 /* 2441 * Give low priority threads a better chance to run. 2442 */ 2443 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2444 sched_prio(td, PUSER); 2445 2446 wakeup_swapper = sleepq_abort(td, intrval); 2447 } else { 2448 /* 2449 * Other states do nothing with the signal immediately, 2450 * other than kicking ourselves if we are running. 2451 * It will either never be noticed, or noticed very soon. 2452 */ 2453 #ifdef SMP 2454 if (TD_IS_RUNNING(td) && td != curthread) 2455 forward_signal(td); 2456 #endif 2457 } 2458 out: 2459 PROC_SUNLOCK(p); 2460 thread_unlock(td); 2461 if (wakeup_swapper) 2462 kick_proc0(); 2463 } 2464 2465 static int 2466 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2467 { 2468 struct thread *td2; 2469 int wakeup_swapper; 2470 2471 PROC_LOCK_ASSERT(p, MA_OWNED); 2472 PROC_SLOCK_ASSERT(p, MA_OWNED); 2473 MPASS(sending || td == curthread); 2474 2475 wakeup_swapper = 0; 2476 FOREACH_THREAD_IN_PROC(p, td2) { 2477 thread_lock(td2); 2478 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2479 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2480 (td2->td_flags & TDF_SINTR)) { 2481 if (td2->td_flags & TDF_SBDRY) { 2482 /* 2483 * Once a thread is asleep with 2484 * TDF_SBDRY and without TDF_SERESTART 2485 * or TDF_SEINTR set, it should never 2486 * become suspended due to this check. 2487 */ 2488 KASSERT(!TD_IS_SUSPENDED(td2), 2489 ("thread with deferred stops suspended")); 2490 if (TD_SBDRY_INTR(td2)) 2491 wakeup_swapper |= sleepq_abort(td2, 2492 TD_SBDRY_ERRNO(td2)); 2493 } else if (!TD_IS_SUSPENDED(td2)) { 2494 thread_suspend_one(td2); 2495 } 2496 } else if (!TD_IS_SUSPENDED(td2)) { 2497 if (sending || td != td2) 2498 td2->td_flags |= TDF_ASTPENDING; 2499 #ifdef SMP 2500 if (TD_IS_RUNNING(td2) && td2 != td) 2501 forward_signal(td2); 2502 #endif 2503 } 2504 thread_unlock(td2); 2505 } 2506 return (wakeup_swapper); 2507 } 2508 2509 /* 2510 * Stop the process for an event deemed interesting to the debugger. If si is 2511 * non-NULL, this is a signal exchange; the new signal requested by the 2512 * debugger will be returned for handling. If si is NULL, this is some other 2513 * type of interesting event. The debugger may request a signal be delivered in 2514 * that case as well, however it will be deferred until it can be handled. 2515 */ 2516 int 2517 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2518 { 2519 struct proc *p = td->td_proc; 2520 struct thread *td2; 2521 ksiginfo_t ksi; 2522 int prop; 2523 2524 PROC_LOCK_ASSERT(p, MA_OWNED); 2525 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2526 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2527 &p->p_mtx.lock_object, "Stopping for traced signal"); 2528 2529 td->td_xsig = sig; 2530 2531 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2532 td->td_dbgflags |= TDB_XSIG; 2533 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2534 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2535 PROC_SLOCK(p); 2536 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2537 if (P_KILLED(p)) { 2538 /* 2539 * Ensure that, if we've been PT_KILLed, the 2540 * exit status reflects that. Another thread 2541 * may also be in ptracestop(), having just 2542 * received the SIGKILL, but this thread was 2543 * unsuspended first. 2544 */ 2545 td->td_dbgflags &= ~TDB_XSIG; 2546 td->td_xsig = SIGKILL; 2547 p->p_ptevents = 0; 2548 break; 2549 } 2550 if (p->p_flag & P_SINGLE_EXIT && 2551 !(td->td_dbgflags & TDB_EXIT)) { 2552 /* 2553 * Ignore ptrace stops except for thread exit 2554 * events when the process exits. 2555 */ 2556 td->td_dbgflags &= ~TDB_XSIG; 2557 PROC_SUNLOCK(p); 2558 return (0); 2559 } 2560 2561 /* 2562 * Make wait(2) work. Ensure that right after the 2563 * attach, the thread which was decided to become the 2564 * leader of attach gets reported to the waiter. 2565 * Otherwise, just avoid overwriting another thread's 2566 * assignment to p_xthread. If another thread has 2567 * already set p_xthread, the current thread will get 2568 * a chance to report itself upon the next iteration. 2569 */ 2570 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2571 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2572 p->p_xthread == NULL)) { 2573 p->p_xsig = sig; 2574 p->p_xthread = td; 2575 2576 /* 2577 * If we are on sleepqueue already, 2578 * let sleepqueue code decide if it 2579 * needs to go sleep after attach. 2580 */ 2581 if (td->td_wchan == NULL) 2582 td->td_dbgflags &= ~TDB_FSTP; 2583 2584 p->p_flag2 &= ~P2_PTRACE_FSTP; 2585 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2586 sig_suspend_threads(td, p, 0); 2587 } 2588 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2589 td->td_dbgflags &= ~TDB_STOPATFORK; 2590 } 2591 stopme: 2592 thread_suspend_switch(td, p); 2593 if (p->p_xthread == td) 2594 p->p_xthread = NULL; 2595 if (!(p->p_flag & P_TRACED)) 2596 break; 2597 if (td->td_dbgflags & TDB_SUSPEND) { 2598 if (p->p_flag & P_SINGLE_EXIT) 2599 break; 2600 goto stopme; 2601 } 2602 } 2603 PROC_SUNLOCK(p); 2604 } 2605 2606 if (si != NULL && sig == td->td_xsig) { 2607 /* Parent wants us to take the original signal unchanged. */ 2608 si->ksi_flags |= KSI_HEAD; 2609 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2610 si->ksi_signo = 0; 2611 } else if (td->td_xsig != 0) { 2612 /* 2613 * If parent wants us to take a new signal, then it will leave 2614 * it in td->td_xsig; otherwise we just look for signals again. 2615 */ 2616 ksiginfo_init(&ksi); 2617 ksi.ksi_signo = td->td_xsig; 2618 ksi.ksi_flags |= KSI_PTRACE; 2619 prop = sigprop(td->td_xsig); 2620 td2 = sigtd(p, td->td_xsig, prop); 2621 tdsendsignal(p, td2, td->td_xsig, &ksi); 2622 if (td != td2) 2623 return (0); 2624 } 2625 2626 return (td->td_xsig); 2627 } 2628 2629 static void 2630 reschedule_signals(struct proc *p, sigset_t block, int flags) 2631 { 2632 struct sigacts *ps; 2633 struct thread *td; 2634 int sig; 2635 2636 PROC_LOCK_ASSERT(p, MA_OWNED); 2637 ps = p->p_sigacts; 2638 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2639 MA_OWNED : MA_NOTOWNED); 2640 if (SIGISEMPTY(p->p_siglist)) 2641 return; 2642 SIGSETAND(block, p->p_siglist); 2643 while ((sig = sig_ffs(&block)) != 0) { 2644 SIGDELSET(block, sig); 2645 td = sigtd(p, sig, 0); 2646 signotify(td); 2647 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2648 mtx_lock(&ps->ps_mtx); 2649 if (p->p_flag & P_TRACED || 2650 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2651 !SIGISMEMBER(td->td_sigmask, sig))) 2652 tdsigwakeup(td, sig, SIG_CATCH, 2653 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2654 ERESTART)); 2655 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2656 mtx_unlock(&ps->ps_mtx); 2657 } 2658 } 2659 2660 void 2661 tdsigcleanup(struct thread *td) 2662 { 2663 struct proc *p; 2664 sigset_t unblocked; 2665 2666 p = td->td_proc; 2667 PROC_LOCK_ASSERT(p, MA_OWNED); 2668 2669 sigqueue_flush(&td->td_sigqueue); 2670 if (p->p_numthreads == 1) 2671 return; 2672 2673 /* 2674 * Since we cannot handle signals, notify signal post code 2675 * about this by filling the sigmask. 2676 * 2677 * Also, if needed, wake up thread(s) that do not block the 2678 * same signals as the exiting thread, since the thread might 2679 * have been selected for delivery and woken up. 2680 */ 2681 SIGFILLSET(unblocked); 2682 SIGSETNAND(unblocked, td->td_sigmask); 2683 SIGFILLSET(td->td_sigmask); 2684 reschedule_signals(p, unblocked, 0); 2685 2686 } 2687 2688 static int 2689 sigdeferstop_curr_flags(int cflags) 2690 { 2691 2692 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2693 (cflags & TDF_SBDRY) != 0); 2694 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2695 } 2696 2697 /* 2698 * Defer the delivery of SIGSTOP for the current thread, according to 2699 * the requested mode. Returns previous flags, which must be restored 2700 * by sigallowstop(). 2701 * 2702 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2703 * cleared by the current thread, which allow the lock-less read-only 2704 * accesses below. 2705 */ 2706 int 2707 sigdeferstop_impl(int mode) 2708 { 2709 struct thread *td; 2710 int cflags, nflags; 2711 2712 td = curthread; 2713 cflags = sigdeferstop_curr_flags(td->td_flags); 2714 switch (mode) { 2715 case SIGDEFERSTOP_NOP: 2716 nflags = cflags; 2717 break; 2718 case SIGDEFERSTOP_OFF: 2719 nflags = 0; 2720 break; 2721 case SIGDEFERSTOP_SILENT: 2722 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2723 break; 2724 case SIGDEFERSTOP_EINTR: 2725 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2726 break; 2727 case SIGDEFERSTOP_ERESTART: 2728 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2729 break; 2730 default: 2731 panic("sigdeferstop: invalid mode %x", mode); 2732 break; 2733 } 2734 if (cflags == nflags) 2735 return (SIGDEFERSTOP_VAL_NCHG); 2736 thread_lock(td); 2737 td->td_flags = (td->td_flags & ~cflags) | nflags; 2738 thread_unlock(td); 2739 return (cflags); 2740 } 2741 2742 /* 2743 * Restores the STOP handling mode, typically permitting the delivery 2744 * of SIGSTOP for the current thread. This does not immediately 2745 * suspend if a stop was posted. Instead, the thread will suspend 2746 * either via ast() or a subsequent interruptible sleep. 2747 */ 2748 void 2749 sigallowstop_impl(int prev) 2750 { 2751 struct thread *td; 2752 int cflags; 2753 2754 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2755 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2756 ("sigallowstop: incorrect previous mode %x", prev)); 2757 td = curthread; 2758 cflags = sigdeferstop_curr_flags(td->td_flags); 2759 if (cflags != prev) { 2760 thread_lock(td); 2761 td->td_flags = (td->td_flags & ~cflags) | prev; 2762 thread_unlock(td); 2763 } 2764 } 2765 2766 /* 2767 * If the current process has received a signal (should be caught or cause 2768 * termination, should interrupt current syscall), return the signal number. 2769 * Stop signals with default action are processed immediately, then cleared; 2770 * they aren't returned. This is checked after each entry to the system for 2771 * a syscall or trap (though this can usually be done without calling issignal 2772 * by checking the pending signal masks in cursig.) The normal call 2773 * sequence is 2774 * 2775 * while (sig = cursig(curthread)) 2776 * postsig(sig); 2777 */ 2778 static int 2779 issignal(struct thread *td) 2780 { 2781 struct proc *p; 2782 struct sigacts *ps; 2783 struct sigqueue *queue; 2784 sigset_t sigpending; 2785 ksiginfo_t ksi; 2786 int prop, sig, traced; 2787 2788 p = td->td_proc; 2789 ps = p->p_sigacts; 2790 mtx_assert(&ps->ps_mtx, MA_OWNED); 2791 PROC_LOCK_ASSERT(p, MA_OWNED); 2792 for (;;) { 2793 traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2794 2795 sigpending = td->td_sigqueue.sq_signals; 2796 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2797 SIGSETNAND(sigpending, td->td_sigmask); 2798 2799 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2800 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2801 SIG_STOPSIGMASK(sigpending); 2802 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2803 return (0); 2804 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2805 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2806 SIGISMEMBER(sigpending, SIGSTOP)) { 2807 /* 2808 * If debugger just attached, always consume 2809 * SIGSTOP from ptrace(PT_ATTACH) first, to 2810 * execute the debugger attach ritual in 2811 * order. 2812 */ 2813 sig = SIGSTOP; 2814 td->td_dbgflags |= TDB_FSTP; 2815 } else { 2816 sig = sig_ffs(&sigpending); 2817 } 2818 2819 if (p->p_stops & S_SIG) { 2820 mtx_unlock(&ps->ps_mtx); 2821 stopevent(p, S_SIG, sig); 2822 mtx_lock(&ps->ps_mtx); 2823 } 2824 2825 /* 2826 * We should see pending but ignored signals 2827 * only if P_TRACED was on when they were posted. 2828 */ 2829 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2830 sigqueue_delete(&td->td_sigqueue, sig); 2831 sigqueue_delete(&p->p_sigqueue, sig); 2832 continue; 2833 } 2834 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2835 /* 2836 * If traced, always stop. 2837 * Remove old signal from queue before the stop. 2838 * XXX shrug off debugger, it causes siginfo to 2839 * be thrown away. 2840 */ 2841 queue = &td->td_sigqueue; 2842 ksiginfo_init(&ksi); 2843 if (sigqueue_get(queue, sig, &ksi) == 0) { 2844 queue = &p->p_sigqueue; 2845 sigqueue_get(queue, sig, &ksi); 2846 } 2847 td->td_si = ksi.ksi_info; 2848 2849 mtx_unlock(&ps->ps_mtx); 2850 sig = ptracestop(td, sig, &ksi); 2851 mtx_lock(&ps->ps_mtx); 2852 2853 td->td_si.si_signo = 0; 2854 2855 /* 2856 * Keep looking if the debugger discarded or 2857 * replaced the signal. 2858 */ 2859 if (sig == 0) 2860 continue; 2861 2862 /* 2863 * If the signal became masked, re-queue it. 2864 */ 2865 if (SIGISMEMBER(td->td_sigmask, sig)) { 2866 ksi.ksi_flags |= KSI_HEAD; 2867 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2868 continue; 2869 } 2870 2871 /* 2872 * If the traced bit got turned off, requeue 2873 * the signal and go back up to the top to 2874 * rescan signals. This ensures that p_sig* 2875 * and p_sigact are consistent. 2876 */ 2877 if ((p->p_flag & P_TRACED) == 0) { 2878 ksi.ksi_flags |= KSI_HEAD; 2879 sigqueue_add(queue, sig, &ksi); 2880 continue; 2881 } 2882 } 2883 2884 prop = sigprop(sig); 2885 2886 /* 2887 * Decide whether the signal should be returned. 2888 * Return the signal's number, or fall through 2889 * to clear it from the pending mask. 2890 */ 2891 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2892 2893 case (intptr_t)SIG_DFL: 2894 /* 2895 * Don't take default actions on system processes. 2896 */ 2897 if (p->p_pid <= 1) { 2898 #ifdef DIAGNOSTIC 2899 /* 2900 * Are you sure you want to ignore SIGSEGV 2901 * in init? XXX 2902 */ 2903 printf("Process (pid %lu) got signal %d\n", 2904 (u_long)p->p_pid, sig); 2905 #endif 2906 break; /* == ignore */ 2907 } 2908 /* 2909 * If there is a pending stop signal to process with 2910 * default action, stop here, then clear the signal. 2911 * Traced or exiting processes should ignore stops. 2912 * Additionally, a member of an orphaned process group 2913 * should ignore tty stops. 2914 */ 2915 if (prop & SIGPROP_STOP) { 2916 if (p->p_flag & 2917 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 2918 (p->p_pgrp->pg_jobc == 0 && 2919 prop & SIGPROP_TTYSTOP)) 2920 break; /* == ignore */ 2921 if (TD_SBDRY_INTR(td)) { 2922 KASSERT((td->td_flags & TDF_SBDRY) != 0, 2923 ("lost TDF_SBDRY")); 2924 return (-1); 2925 } 2926 mtx_unlock(&ps->ps_mtx); 2927 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2928 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2929 sigqueue_delete(&td->td_sigqueue, sig); 2930 sigqueue_delete(&p->p_sigqueue, sig); 2931 p->p_flag |= P_STOPPED_SIG; 2932 p->p_xsig = sig; 2933 PROC_SLOCK(p); 2934 sig_suspend_threads(td, p, 0); 2935 thread_suspend_switch(td, p); 2936 PROC_SUNLOCK(p); 2937 mtx_lock(&ps->ps_mtx); 2938 goto next; 2939 } else if (prop & SIGPROP_IGNORE) { 2940 /* 2941 * Except for SIGCONT, shouldn't get here. 2942 * Default action is to ignore; drop it. 2943 */ 2944 break; /* == ignore */ 2945 } else 2946 return (sig); 2947 /*NOTREACHED*/ 2948 2949 case (intptr_t)SIG_IGN: 2950 /* 2951 * Masking above should prevent us ever trying 2952 * to take action on an ignored signal other 2953 * than SIGCONT, unless process is traced. 2954 */ 2955 if ((prop & SIGPROP_CONT) == 0 && 2956 (p->p_flag & P_TRACED) == 0) 2957 printf("issignal\n"); 2958 break; /* == ignore */ 2959 2960 default: 2961 /* 2962 * This signal has an action, let 2963 * postsig() process it. 2964 */ 2965 return (sig); 2966 } 2967 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2968 sigqueue_delete(&p->p_sigqueue, sig); 2969 next:; 2970 } 2971 /* NOTREACHED */ 2972 } 2973 2974 void 2975 thread_stopped(struct proc *p) 2976 { 2977 int n; 2978 2979 PROC_LOCK_ASSERT(p, MA_OWNED); 2980 PROC_SLOCK_ASSERT(p, MA_OWNED); 2981 n = p->p_suspcount; 2982 if (p == curproc) 2983 n++; 2984 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2985 PROC_SUNLOCK(p); 2986 p->p_flag &= ~P_WAITED; 2987 PROC_LOCK(p->p_pptr); 2988 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2989 CLD_TRAPPED : CLD_STOPPED); 2990 PROC_UNLOCK(p->p_pptr); 2991 PROC_SLOCK(p); 2992 } 2993 } 2994 2995 /* 2996 * Take the action for the specified signal 2997 * from the current set of pending signals. 2998 */ 2999 int 3000 postsig(int sig) 3001 { 3002 struct thread *td; 3003 struct proc *p; 3004 struct sigacts *ps; 3005 sig_t action; 3006 ksiginfo_t ksi; 3007 sigset_t returnmask; 3008 3009 KASSERT(sig != 0, ("postsig")); 3010 3011 td = curthread; 3012 p = td->td_proc; 3013 PROC_LOCK_ASSERT(p, MA_OWNED); 3014 ps = p->p_sigacts; 3015 mtx_assert(&ps->ps_mtx, MA_OWNED); 3016 ksiginfo_init(&ksi); 3017 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3018 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3019 return (0); 3020 ksi.ksi_signo = sig; 3021 if (ksi.ksi_code == SI_TIMER) 3022 itimer_accept(p, ksi.ksi_timerid, &ksi); 3023 action = ps->ps_sigact[_SIG_IDX(sig)]; 3024 #ifdef KTRACE 3025 if (KTRPOINT(td, KTR_PSIG)) 3026 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3027 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3028 #endif 3029 if ((p->p_stops & S_SIG) != 0) { 3030 mtx_unlock(&ps->ps_mtx); 3031 stopevent(p, S_SIG, sig); 3032 mtx_lock(&ps->ps_mtx); 3033 } 3034 3035 if (action == SIG_DFL) { 3036 /* 3037 * Default action, where the default is to kill 3038 * the process. (Other cases were ignored above.) 3039 */ 3040 mtx_unlock(&ps->ps_mtx); 3041 proc_td_siginfo_capture(td, &ksi.ksi_info); 3042 sigexit(td, sig); 3043 /* NOTREACHED */ 3044 } else { 3045 /* 3046 * If we get here, the signal must be caught. 3047 */ 3048 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3049 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3050 ("postsig action: blocked sig %d", sig)); 3051 3052 /* 3053 * Set the new mask value and also defer further 3054 * occurrences of this signal. 3055 * 3056 * Special case: user has done a sigsuspend. Here the 3057 * current mask is not of interest, but rather the 3058 * mask from before the sigsuspend is what we want 3059 * restored after the signal processing is completed. 3060 */ 3061 if (td->td_pflags & TDP_OLDMASK) { 3062 returnmask = td->td_oldsigmask; 3063 td->td_pflags &= ~TDP_OLDMASK; 3064 } else 3065 returnmask = td->td_sigmask; 3066 3067 if (p->p_sig == sig) { 3068 p->p_sig = 0; 3069 } 3070 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3071 postsig_done(sig, td, ps); 3072 } 3073 return (1); 3074 } 3075 3076 void 3077 proc_wkilled(struct proc *p) 3078 { 3079 3080 PROC_LOCK_ASSERT(p, MA_OWNED); 3081 if ((p->p_flag & P_WKILLED) == 0) { 3082 p->p_flag |= P_WKILLED; 3083 /* 3084 * Notify swapper that there is a process to swap in. 3085 * The notification is racy, at worst it would take 10 3086 * seconds for the swapper process to notice. 3087 */ 3088 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3089 wakeup(&proc0); 3090 } 3091 } 3092 3093 /* 3094 * Kill the current process for stated reason. 3095 */ 3096 void 3097 killproc(struct proc *p, char *why) 3098 { 3099 3100 PROC_LOCK_ASSERT(p, MA_OWNED); 3101 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3102 p->p_comm); 3103 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3104 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3105 p->p_ucred->cr_uid, why); 3106 proc_wkilled(p); 3107 kern_psignal(p, SIGKILL); 3108 } 3109 3110 /* 3111 * Force the current process to exit with the specified signal, dumping core 3112 * if appropriate. We bypass the normal tests for masked and caught signals, 3113 * allowing unrecoverable failures to terminate the process without changing 3114 * signal state. Mark the accounting record with the signal termination. 3115 * If dumping core, save the signal number for the debugger. Calls exit and 3116 * does not return. 3117 */ 3118 void 3119 sigexit(struct thread *td, int sig) 3120 { 3121 struct proc *p = td->td_proc; 3122 3123 PROC_LOCK_ASSERT(p, MA_OWNED); 3124 p->p_acflag |= AXSIG; 3125 /* 3126 * We must be single-threading to generate a core dump. This 3127 * ensures that the registers in the core file are up-to-date. 3128 * Also, the ELF dump handler assumes that the thread list doesn't 3129 * change out from under it. 3130 * 3131 * XXX If another thread attempts to single-thread before us 3132 * (e.g. via fork()), we won't get a dump at all. 3133 */ 3134 if ((sigprop(sig) & SIGPROP_CORE) && 3135 thread_single(p, SINGLE_NO_EXIT) == 0) { 3136 p->p_sig = sig; 3137 /* 3138 * Log signals which would cause core dumps 3139 * (Log as LOG_INFO to appease those who don't want 3140 * these messages.) 3141 * XXX : Todo, as well as euid, write out ruid too 3142 * Note that coredump() drops proc lock. 3143 */ 3144 if (coredump(td) == 0) 3145 sig |= WCOREFLAG; 3146 if (kern_logsigexit) 3147 log(LOG_INFO, 3148 "pid %d (%s), jid %d, uid %d: exited on " 3149 "signal %d%s\n", p->p_pid, p->p_comm, 3150 p->p_ucred->cr_prison->pr_id, 3151 td->td_ucred->cr_uid, 3152 sig &~ WCOREFLAG, 3153 sig & WCOREFLAG ? " (core dumped)" : ""); 3154 } else 3155 PROC_UNLOCK(p); 3156 exit1(td, 0, sig); 3157 /* NOTREACHED */ 3158 } 3159 3160 /* 3161 * Send queued SIGCHLD to parent when child process's state 3162 * is changed. 3163 */ 3164 static void 3165 sigparent(struct proc *p, int reason, int status) 3166 { 3167 PROC_LOCK_ASSERT(p, MA_OWNED); 3168 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3169 3170 if (p->p_ksi != NULL) { 3171 p->p_ksi->ksi_signo = SIGCHLD; 3172 p->p_ksi->ksi_code = reason; 3173 p->p_ksi->ksi_status = status; 3174 p->p_ksi->ksi_pid = p->p_pid; 3175 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3176 if (KSI_ONQ(p->p_ksi)) 3177 return; 3178 } 3179 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3180 } 3181 3182 static void 3183 childproc_jobstate(struct proc *p, int reason, int sig) 3184 { 3185 struct sigacts *ps; 3186 3187 PROC_LOCK_ASSERT(p, MA_OWNED); 3188 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3189 3190 /* 3191 * Wake up parent sleeping in kern_wait(), also send 3192 * SIGCHLD to parent, but SIGCHLD does not guarantee 3193 * that parent will awake, because parent may masked 3194 * the signal. 3195 */ 3196 p->p_pptr->p_flag |= P_STATCHILD; 3197 wakeup(p->p_pptr); 3198 3199 ps = p->p_pptr->p_sigacts; 3200 mtx_lock(&ps->ps_mtx); 3201 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3202 mtx_unlock(&ps->ps_mtx); 3203 sigparent(p, reason, sig); 3204 } else 3205 mtx_unlock(&ps->ps_mtx); 3206 } 3207 3208 void 3209 childproc_stopped(struct proc *p, int reason) 3210 { 3211 3212 childproc_jobstate(p, reason, p->p_xsig); 3213 } 3214 3215 void 3216 childproc_continued(struct proc *p) 3217 { 3218 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3219 } 3220 3221 void 3222 childproc_exited(struct proc *p) 3223 { 3224 int reason, status; 3225 3226 if (WCOREDUMP(p->p_xsig)) { 3227 reason = CLD_DUMPED; 3228 status = WTERMSIG(p->p_xsig); 3229 } else if (WIFSIGNALED(p->p_xsig)) { 3230 reason = CLD_KILLED; 3231 status = WTERMSIG(p->p_xsig); 3232 } else { 3233 reason = CLD_EXITED; 3234 status = p->p_xexit; 3235 } 3236 /* 3237 * XXX avoid calling wakeup(p->p_pptr), the work is 3238 * done in exit1(). 3239 */ 3240 sigparent(p, reason, status); 3241 } 3242 3243 #define MAX_NUM_CORE_FILES 100000 3244 #ifndef NUM_CORE_FILES 3245 #define NUM_CORE_FILES 5 3246 #endif 3247 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3248 static int num_cores = NUM_CORE_FILES; 3249 3250 static int 3251 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3252 { 3253 int error; 3254 int new_val; 3255 3256 new_val = num_cores; 3257 error = sysctl_handle_int(oidp, &new_val, 0, req); 3258 if (error != 0 || req->newptr == NULL) 3259 return (error); 3260 if (new_val > MAX_NUM_CORE_FILES) 3261 new_val = MAX_NUM_CORE_FILES; 3262 if (new_val < 0) 3263 new_val = 0; 3264 num_cores = new_val; 3265 return (0); 3266 } 3267 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3268 0, sizeof(int), sysctl_debug_num_cores_check, "I", 3269 "Maximum number of generated process corefiles while using index format"); 3270 3271 #define GZIP_SUFFIX ".gz" 3272 #define ZSTD_SUFFIX ".zst" 3273 3274 int compress_user_cores = 0; 3275 3276 static int 3277 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3278 { 3279 int error, val; 3280 3281 val = compress_user_cores; 3282 error = sysctl_handle_int(oidp, &val, 0, req); 3283 if (error != 0 || req->newptr == NULL) 3284 return (error); 3285 if (val != 0 && !compressor_avail(val)) 3286 return (EINVAL); 3287 compress_user_cores = val; 3288 return (error); 3289 } 3290 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, CTLTYPE_INT | CTLFLAG_RWTUN, 3291 0, sizeof(int), sysctl_compress_user_cores, "I", 3292 "Enable compression of user corefiles (" 3293 __XSTRING(COMPRESS_GZIP) " = gzip, " 3294 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3295 3296 int compress_user_cores_level = 6; 3297 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3298 &compress_user_cores_level, 0, 3299 "Corefile compression level"); 3300 3301 /* 3302 * Protect the access to corefilename[] by allproc_lock. 3303 */ 3304 #define corefilename_lock allproc_lock 3305 3306 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3307 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3308 3309 static int 3310 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3311 { 3312 int error; 3313 3314 sx_xlock(&corefilename_lock); 3315 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3316 req); 3317 sx_xunlock(&corefilename_lock); 3318 3319 return (error); 3320 } 3321 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3322 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3323 "Process corefile name format string"); 3324 3325 static void 3326 vnode_close_locked(struct thread *td, struct vnode *vp) 3327 { 3328 3329 VOP_UNLOCK(vp, 0); 3330 vn_close(vp, FWRITE, td->td_ucred, td); 3331 } 3332 3333 /* 3334 * If the core format has a %I in it, then we need to check 3335 * for existing corefiles before defining a name. 3336 * To do this we iterate over 0..ncores to find a 3337 * non-existing core file name to use. If all core files are 3338 * already used we choose the oldest one. 3339 */ 3340 static int 3341 corefile_open_last(struct thread *td, char *name, int indexpos, 3342 int indexlen, int ncores, struct vnode **vpp) 3343 { 3344 struct vnode *oldvp, *nextvp, *vp; 3345 struct vattr vattr; 3346 struct nameidata nd; 3347 int error, i, flags, oflags, cmode; 3348 char ch; 3349 struct timespec lasttime; 3350 3351 nextvp = oldvp = NULL; 3352 cmode = S_IRUSR | S_IWUSR; 3353 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3354 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3355 3356 for (i = 0; i < ncores; i++) { 3357 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3358 3359 ch = name[indexpos + indexlen]; 3360 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3361 i); 3362 name[indexpos + indexlen] = ch; 3363 3364 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3365 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3366 NULL); 3367 if (error != 0) 3368 break; 3369 3370 vp = nd.ni_vp; 3371 NDFREE(&nd, NDF_ONLY_PNBUF); 3372 if ((flags & O_CREAT) == O_CREAT) { 3373 nextvp = vp; 3374 break; 3375 } 3376 3377 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3378 if (error != 0) { 3379 vnode_close_locked(td, vp); 3380 break; 3381 } 3382 3383 if (oldvp == NULL || 3384 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3385 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3386 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3387 if (oldvp != NULL) 3388 vnode_close_locked(td, oldvp); 3389 oldvp = vp; 3390 lasttime = vattr.va_mtime; 3391 } else { 3392 vnode_close_locked(td, vp); 3393 } 3394 } 3395 3396 if (oldvp != NULL) { 3397 if (nextvp == NULL) { 3398 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3399 error = EFAULT; 3400 vnode_close_locked(td, oldvp); 3401 } else { 3402 nextvp = oldvp; 3403 } 3404 } else { 3405 vnode_close_locked(td, oldvp); 3406 } 3407 } 3408 if (error != 0) { 3409 if (nextvp != NULL) 3410 vnode_close_locked(td, oldvp); 3411 } else { 3412 *vpp = nextvp; 3413 } 3414 3415 return (error); 3416 } 3417 3418 /* 3419 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3420 * Expand the name described in corefilename, using name, uid, and pid 3421 * and open/create core file. 3422 * corefilename is a printf-like string, with three format specifiers: 3423 * %N name of process ("name") 3424 * %P process id (pid) 3425 * %U user id (uid) 3426 * For example, "%N.core" is the default; they can be disabled completely 3427 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3428 * This is controlled by the sysctl variable kern.corefile (see above). 3429 */ 3430 static int 3431 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3432 int compress, int signum, struct vnode **vpp, char **namep) 3433 { 3434 struct sbuf sb; 3435 struct nameidata nd; 3436 const char *format; 3437 char *hostname, *name; 3438 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3439 3440 hostname = NULL; 3441 format = corefilename; 3442 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3443 indexlen = 0; 3444 indexpos = -1; 3445 ncores = num_cores; 3446 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3447 sx_slock(&corefilename_lock); 3448 for (i = 0; format[i] != '\0'; i++) { 3449 switch (format[i]) { 3450 case '%': /* Format character */ 3451 i++; 3452 switch (format[i]) { 3453 case '%': 3454 sbuf_putc(&sb, '%'); 3455 break; 3456 case 'H': /* hostname */ 3457 if (hostname == NULL) { 3458 hostname = malloc(MAXHOSTNAMELEN, 3459 M_TEMP, M_WAITOK); 3460 } 3461 getcredhostname(td->td_ucred, hostname, 3462 MAXHOSTNAMELEN); 3463 sbuf_printf(&sb, "%s", hostname); 3464 break; 3465 case 'I': /* autoincrementing index */ 3466 if (indexpos != -1) { 3467 sbuf_printf(&sb, "%%I"); 3468 break; 3469 } 3470 3471 indexpos = sbuf_len(&sb); 3472 sbuf_printf(&sb, "%u", ncores - 1); 3473 indexlen = sbuf_len(&sb) - indexpos; 3474 break; 3475 case 'N': /* process name */ 3476 sbuf_printf(&sb, "%s", comm); 3477 break; 3478 case 'P': /* process id */ 3479 sbuf_printf(&sb, "%u", pid); 3480 break; 3481 case 'S': /* signal number */ 3482 sbuf_printf(&sb, "%i", signum); 3483 break; 3484 case 'U': /* user id */ 3485 sbuf_printf(&sb, "%u", uid); 3486 break; 3487 default: 3488 log(LOG_ERR, 3489 "Unknown format character %c in " 3490 "corename `%s'\n", format[i], format); 3491 break; 3492 } 3493 break; 3494 default: 3495 sbuf_putc(&sb, format[i]); 3496 break; 3497 } 3498 } 3499 sx_sunlock(&corefilename_lock); 3500 free(hostname, M_TEMP); 3501 if (compress == COMPRESS_GZIP) 3502 sbuf_printf(&sb, GZIP_SUFFIX); 3503 else if (compress == COMPRESS_ZSTD) 3504 sbuf_printf(&sb, ZSTD_SUFFIX); 3505 if (sbuf_error(&sb) != 0) { 3506 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3507 "long\n", (long)pid, comm, (u_long)uid); 3508 sbuf_delete(&sb); 3509 free(name, M_TEMP); 3510 return (ENOMEM); 3511 } 3512 sbuf_finish(&sb); 3513 sbuf_delete(&sb); 3514 3515 if (indexpos != -1) { 3516 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3517 vpp); 3518 if (error != 0) { 3519 log(LOG_ERR, 3520 "pid %d (%s), uid (%u): Path `%s' failed " 3521 "on initial open test, error = %d\n", 3522 pid, comm, uid, name, error); 3523 } 3524 } else { 3525 cmode = S_IRUSR | S_IWUSR; 3526 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3527 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3528 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3529 if ((td->td_proc->p_flag & P_SUGID) != 0) 3530 flags |= O_EXCL; 3531 3532 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3533 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3534 NULL); 3535 if (error == 0) { 3536 *vpp = nd.ni_vp; 3537 NDFREE(&nd, NDF_ONLY_PNBUF); 3538 } 3539 } 3540 3541 if (error != 0) { 3542 #ifdef AUDIT 3543 audit_proc_coredump(td, name, error); 3544 #endif 3545 free(name, M_TEMP); 3546 return (error); 3547 } 3548 *namep = name; 3549 return (0); 3550 } 3551 3552 /* 3553 * Dump a process' core. The main routine does some 3554 * policy checking, and creates the name of the coredump; 3555 * then it passes on a vnode and a size limit to the process-specific 3556 * coredump routine if there is one; if there _is not_ one, it returns 3557 * ENOSYS; otherwise it returns the error from the process-specific routine. 3558 */ 3559 3560 static int 3561 coredump(struct thread *td) 3562 { 3563 struct proc *p = td->td_proc; 3564 struct ucred *cred = td->td_ucred; 3565 struct vnode *vp; 3566 struct flock lf; 3567 struct vattr vattr; 3568 int error, error1, locked; 3569 char *name; /* name of corefile */ 3570 void *rl_cookie; 3571 off_t limit; 3572 char *fullpath, *freepath = NULL; 3573 struct sbuf *sb; 3574 3575 PROC_LOCK_ASSERT(p, MA_OWNED); 3576 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3577 _STOPEVENT(p, S_CORE, 0); 3578 3579 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3580 (p->p_flag2 & P2_NOTRACE) != 0) { 3581 PROC_UNLOCK(p); 3582 return (EFAULT); 3583 } 3584 3585 /* 3586 * Note that the bulk of limit checking is done after 3587 * the corefile is created. The exception is if the limit 3588 * for corefiles is 0, in which case we don't bother 3589 * creating the corefile at all. This layout means that 3590 * a corefile is truncated instead of not being created, 3591 * if it is larger than the limit. 3592 */ 3593 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3594 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3595 PROC_UNLOCK(p); 3596 return (EFBIG); 3597 } 3598 PROC_UNLOCK(p); 3599 3600 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3601 compress_user_cores, p->p_sig, &vp, &name); 3602 if (error != 0) 3603 return (error); 3604 3605 /* 3606 * Don't dump to non-regular files or files with links. 3607 * Do not dump into system files. Effective user must own the corefile. 3608 */ 3609 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3610 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 3611 vattr.va_uid != cred->cr_uid) { 3612 VOP_UNLOCK(vp, 0); 3613 error = EFAULT; 3614 goto out; 3615 } 3616 3617 VOP_UNLOCK(vp, 0); 3618 3619 /* Postpone other writers, including core dumps of other processes. */ 3620 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3621 3622 lf.l_whence = SEEK_SET; 3623 lf.l_start = 0; 3624 lf.l_len = 0; 3625 lf.l_type = F_WRLCK; 3626 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3627 3628 VATTR_NULL(&vattr); 3629 vattr.va_size = 0; 3630 if (set_core_nodump_flag) 3631 vattr.va_flags = UF_NODUMP; 3632 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3633 VOP_SETATTR(vp, &vattr, cred); 3634 VOP_UNLOCK(vp, 0); 3635 PROC_LOCK(p); 3636 p->p_acflag |= ACORE; 3637 PROC_UNLOCK(p); 3638 3639 if (p->p_sysent->sv_coredump != NULL) { 3640 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3641 } else { 3642 error = ENOSYS; 3643 } 3644 3645 if (locked) { 3646 lf.l_type = F_UNLCK; 3647 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3648 } 3649 vn_rangelock_unlock(vp, rl_cookie); 3650 3651 /* 3652 * Notify the userland helper that a process triggered a core dump. 3653 * This allows the helper to run an automated debugging session. 3654 */ 3655 if (error != 0 || coredump_devctl == 0) 3656 goto out; 3657 sb = sbuf_new_auto(); 3658 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3659 goto out2; 3660 sbuf_printf(sb, "comm=\""); 3661 devctl_safe_quote_sb(sb, fullpath); 3662 free(freepath, M_TEMP); 3663 sbuf_printf(sb, "\" core=\""); 3664 3665 /* 3666 * We can't lookup core file vp directly. When we're replacing a core, and 3667 * other random times, we flush the name cache, so it will fail. Instead, 3668 * if the path of the core is relative, add the current dir in front if it. 3669 */ 3670 if (name[0] != '/') { 3671 fullpath = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 3672 if (kern___getcwd(td, fullpath, UIO_SYSSPACE, MAXPATHLEN, MAXPATHLEN) != 0) { 3673 free(fullpath, M_TEMP); 3674 goto out2; 3675 } 3676 devctl_safe_quote_sb(sb, fullpath); 3677 free(fullpath, M_TEMP); 3678 sbuf_putc(sb, '/'); 3679 } 3680 devctl_safe_quote_sb(sb, name); 3681 sbuf_printf(sb, "\""); 3682 if (sbuf_finish(sb) == 0) 3683 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 3684 out2: 3685 sbuf_delete(sb); 3686 out: 3687 error1 = vn_close(vp, FWRITE, cred, td); 3688 if (error == 0) 3689 error = error1; 3690 #ifdef AUDIT 3691 audit_proc_coredump(td, name, error); 3692 #endif 3693 free(name, M_TEMP); 3694 return (error); 3695 } 3696 3697 /* 3698 * Nonexistent system call-- signal process (may want to handle it). Flag 3699 * error in case process won't see signal immediately (blocked or ignored). 3700 */ 3701 #ifndef _SYS_SYSPROTO_H_ 3702 struct nosys_args { 3703 int dummy; 3704 }; 3705 #endif 3706 /* ARGSUSED */ 3707 int 3708 nosys(struct thread *td, struct nosys_args *args) 3709 { 3710 struct proc *p; 3711 3712 p = td->td_proc; 3713 3714 PROC_LOCK(p); 3715 tdsignal(td, SIGSYS); 3716 PROC_UNLOCK(p); 3717 if (kern_lognosys == 1 || kern_lognosys == 3) { 3718 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3719 td->td_sa.code); 3720 } 3721 if (kern_lognosys == 2 || kern_lognosys == 3) { 3722 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3723 td->td_sa.code); 3724 } 3725 return (ENOSYS); 3726 } 3727 3728 /* 3729 * Send a SIGIO or SIGURG signal to a process or process group using stored 3730 * credentials rather than those of the current process. 3731 */ 3732 void 3733 pgsigio(struct sigio **sigiop, int sig, int checkctty) 3734 { 3735 ksiginfo_t ksi; 3736 struct sigio *sigio; 3737 3738 ksiginfo_init(&ksi); 3739 ksi.ksi_signo = sig; 3740 ksi.ksi_code = SI_KERNEL; 3741 3742 SIGIO_LOCK(); 3743 sigio = *sigiop; 3744 if (sigio == NULL) { 3745 SIGIO_UNLOCK(); 3746 return; 3747 } 3748 if (sigio->sio_pgid > 0) { 3749 PROC_LOCK(sigio->sio_proc); 3750 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3751 kern_psignal(sigio->sio_proc, sig); 3752 PROC_UNLOCK(sigio->sio_proc); 3753 } else if (sigio->sio_pgid < 0) { 3754 struct proc *p; 3755 3756 PGRP_LOCK(sigio->sio_pgrp); 3757 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3758 PROC_LOCK(p); 3759 if (p->p_state == PRS_NORMAL && 3760 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3761 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3762 kern_psignal(p, sig); 3763 PROC_UNLOCK(p); 3764 } 3765 PGRP_UNLOCK(sigio->sio_pgrp); 3766 } 3767 SIGIO_UNLOCK(); 3768 } 3769 3770 static int 3771 filt_sigattach(struct knote *kn) 3772 { 3773 struct proc *p = curproc; 3774 3775 kn->kn_ptr.p_proc = p; 3776 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3777 3778 knlist_add(p->p_klist, kn, 0); 3779 3780 return (0); 3781 } 3782 3783 static void 3784 filt_sigdetach(struct knote *kn) 3785 { 3786 struct proc *p = kn->kn_ptr.p_proc; 3787 3788 knlist_remove(p->p_klist, kn, 0); 3789 } 3790 3791 /* 3792 * signal knotes are shared with proc knotes, so we apply a mask to 3793 * the hint in order to differentiate them from process hints. This 3794 * could be avoided by using a signal-specific knote list, but probably 3795 * isn't worth the trouble. 3796 */ 3797 static int 3798 filt_signal(struct knote *kn, long hint) 3799 { 3800 3801 if (hint & NOTE_SIGNAL) { 3802 hint &= ~NOTE_SIGNAL; 3803 3804 if (kn->kn_id == hint) 3805 kn->kn_data++; 3806 } 3807 return (kn->kn_data != 0); 3808 } 3809 3810 struct sigacts * 3811 sigacts_alloc(void) 3812 { 3813 struct sigacts *ps; 3814 3815 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3816 refcount_init(&ps->ps_refcnt, 1); 3817 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3818 return (ps); 3819 } 3820 3821 void 3822 sigacts_free(struct sigacts *ps) 3823 { 3824 3825 if (refcount_release(&ps->ps_refcnt) == 0) 3826 return; 3827 mtx_destroy(&ps->ps_mtx); 3828 free(ps, M_SUBPROC); 3829 } 3830 3831 struct sigacts * 3832 sigacts_hold(struct sigacts *ps) 3833 { 3834 3835 refcount_acquire(&ps->ps_refcnt); 3836 return (ps); 3837 } 3838 3839 void 3840 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3841 { 3842 3843 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3844 mtx_lock(&src->ps_mtx); 3845 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3846 mtx_unlock(&src->ps_mtx); 3847 } 3848 3849 int 3850 sigacts_shared(struct sigacts *ps) 3851 { 3852 3853 return (ps->ps_refcnt > 1); 3854 } 3855 3856 void 3857 sig_drop_caught(struct proc *p) 3858 { 3859 int sig; 3860 struct sigacts *ps; 3861 3862 ps = p->p_sigacts; 3863 PROC_LOCK_ASSERT(p, MA_OWNED); 3864 mtx_assert(&ps->ps_mtx, MA_OWNED); 3865 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 3866 sig = sig_ffs(&ps->ps_sigcatch); 3867 sigdflt(ps, sig); 3868 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 3869 sigqueue_delete_proc(p, sig); 3870 } 3871 } 3872