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/capsicum.h> 51 #include <sys/compressor.h> 52 #include <sys/condvar.h> 53 #include <sys/devctl.h> 54 #include <sys/event.h> 55 #include <sys/fcntl.h> 56 #include <sys/imgact.h> 57 #include <sys/kernel.h> 58 #include <sys/ktr.h> 59 #include <sys/ktrace.h> 60 #include <sys/limits.h> 61 #include <sys/lock.h> 62 #include <sys/malloc.h> 63 #include <sys/mutex.h> 64 #include <sys/refcount.h> 65 #include <sys/namei.h> 66 #include <sys/proc.h> 67 #include <sys/procdesc.h> 68 #include <sys/ptrace.h> 69 #include <sys/posix4.h> 70 #include <sys/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 void reschedule_signals(struct proc *p, sigset_t block, int flags); 111 static int sigprop(int sig); 112 static void tdsigwakeup(struct thread *, int, sig_t, int); 113 static int sig_suspend_threads(struct thread *, struct proc *, int); 114 static int filt_sigattach(struct knote *kn); 115 static void filt_sigdetach(struct knote *kn); 116 static int filt_signal(struct knote *kn, long hint); 117 static struct thread *sigtd(struct proc *p, int sig, bool fast_sigblock); 118 static void sigqueue_start(void); 119 120 static uma_zone_t ksiginfo_zone = NULL; 121 struct filterops sig_filtops = { 122 .f_isfd = 0, 123 .f_attach = filt_sigattach, 124 .f_detach = filt_sigdetach, 125 .f_event = filt_signal, 126 }; 127 128 static int kern_logsigexit = 1; 129 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 130 &kern_logsigexit, 0, 131 "Log processes quitting on abnormal signals to syslog(3)"); 132 133 static int kern_forcesigexit = 1; 134 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 135 &kern_forcesigexit, 0, "Force trap signal to be handled"); 136 137 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 138 "POSIX real time signal"); 139 140 static int max_pending_per_proc = 128; 141 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 142 &max_pending_per_proc, 0, "Max pending signals per proc"); 143 144 static int preallocate_siginfo = 1024; 145 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 146 &preallocate_siginfo, 0, "Preallocated signal memory size"); 147 148 static int signal_overflow = 0; 149 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 150 &signal_overflow, 0, "Number of signals overflew"); 151 152 static int signal_alloc_fail = 0; 153 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 154 &signal_alloc_fail, 0, "signals failed to be allocated"); 155 156 static int kern_lognosys = 0; 157 SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 158 "Log invalid syscalls"); 159 160 __read_frequently bool sigfastblock_fetch_always = false; 161 SYSCTL_BOOL(_kern, OID_AUTO, sigfastblock_fetch_always, CTLFLAG_RWTUN, 162 &sigfastblock_fetch_always, 0, 163 "Fetch sigfastblock word on each syscall entry for proper " 164 "blocking semantic"); 165 166 static bool kern_sig_discard_ign = true; 167 SYSCTL_BOOL(_kern, OID_AUTO, sig_discard_ign, CTLFLAG_RWTUN, 168 &kern_sig_discard_ign, 0, 169 "Discard ignored signals on delivery, otherwise queue them to " 170 "the target queue"); 171 172 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 173 174 /* 175 * Policy -- Can ucred cr1 send SIGIO to process cr2? 176 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 177 * in the right situations. 178 */ 179 #define CANSIGIO(cr1, cr2) \ 180 ((cr1)->cr_uid == 0 || \ 181 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 182 (cr1)->cr_uid == (cr2)->cr_ruid || \ 183 (cr1)->cr_ruid == (cr2)->cr_uid || \ 184 (cr1)->cr_uid == (cr2)->cr_uid) 185 186 static int sugid_coredump; 187 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 188 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 189 190 static int capmode_coredump; 191 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 192 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 193 194 static int do_coredump = 1; 195 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 196 &do_coredump, 0, "Enable/Disable coredumps"); 197 198 static int set_core_nodump_flag = 0; 199 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 200 0, "Enable setting the NODUMP flag on coredump files"); 201 202 static int coredump_devctl = 0; 203 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 204 0, "Generate a devctl notification when processes coredump"); 205 206 /* 207 * Signal properties and actions. 208 * The array below categorizes the signals and their default actions 209 * according to the following properties: 210 */ 211 #define SIGPROP_KILL 0x01 /* terminates process by default */ 212 #define SIGPROP_CORE 0x02 /* ditto and coredumps */ 213 #define SIGPROP_STOP 0x04 /* suspend process */ 214 #define SIGPROP_TTYSTOP 0x08 /* ditto, from tty */ 215 #define SIGPROP_IGNORE 0x10 /* ignore by default */ 216 #define SIGPROP_CONT 0x20 /* continue if suspended */ 217 #define SIGPROP_CANTMASK 0x40 /* non-maskable, catchable */ 218 219 static int sigproptbl[NSIG] = { 220 [SIGHUP] = SIGPROP_KILL, 221 [SIGINT] = SIGPROP_KILL, 222 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE, 223 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE, 224 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE, 225 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE, 226 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE, 227 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE, 228 [SIGKILL] = SIGPROP_KILL, 229 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE, 230 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE, 231 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE, 232 [SIGPIPE] = SIGPROP_KILL, 233 [SIGALRM] = SIGPROP_KILL, 234 [SIGTERM] = SIGPROP_KILL, 235 [SIGURG] = SIGPROP_IGNORE, 236 [SIGSTOP] = SIGPROP_STOP, 237 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP, 238 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT, 239 [SIGCHLD] = SIGPROP_IGNORE, 240 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP, 241 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP, 242 [SIGIO] = SIGPROP_IGNORE, 243 [SIGXCPU] = SIGPROP_KILL, 244 [SIGXFSZ] = SIGPROP_KILL, 245 [SIGVTALRM] = SIGPROP_KILL, 246 [SIGPROF] = SIGPROP_KILL, 247 [SIGWINCH] = SIGPROP_IGNORE, 248 [SIGINFO] = SIGPROP_IGNORE, 249 [SIGUSR1] = SIGPROP_KILL, 250 [SIGUSR2] = SIGPROP_KILL, 251 }; 252 253 sigset_t fastblock_mask; 254 255 static void 256 sigqueue_start(void) 257 { 258 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 259 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 260 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 261 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 262 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 263 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 264 SIGFILLSET(fastblock_mask); 265 SIG_CANTMASK(fastblock_mask); 266 } 267 268 ksiginfo_t * 269 ksiginfo_alloc(int wait) 270 { 271 int flags; 272 273 flags = M_ZERO; 274 if (! wait) 275 flags |= M_NOWAIT; 276 if (ksiginfo_zone != NULL) 277 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 278 return (NULL); 279 } 280 281 void 282 ksiginfo_free(ksiginfo_t *ksi) 283 { 284 uma_zfree(ksiginfo_zone, ksi); 285 } 286 287 static __inline int 288 ksiginfo_tryfree(ksiginfo_t *ksi) 289 { 290 if (!(ksi->ksi_flags & KSI_EXT)) { 291 uma_zfree(ksiginfo_zone, ksi); 292 return (1); 293 } 294 return (0); 295 } 296 297 void 298 sigqueue_init(sigqueue_t *list, struct proc *p) 299 { 300 SIGEMPTYSET(list->sq_signals); 301 SIGEMPTYSET(list->sq_kill); 302 SIGEMPTYSET(list->sq_ptrace); 303 TAILQ_INIT(&list->sq_list); 304 list->sq_proc = p; 305 list->sq_flags = SQ_INIT; 306 } 307 308 /* 309 * Get a signal's ksiginfo. 310 * Return: 311 * 0 - signal not found 312 * others - signal number 313 */ 314 static int 315 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 316 { 317 struct proc *p = sq->sq_proc; 318 struct ksiginfo *ksi, *next; 319 int count = 0; 320 321 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 322 323 if (!SIGISMEMBER(sq->sq_signals, signo)) 324 return (0); 325 326 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 327 count++; 328 SIGDELSET(sq->sq_ptrace, signo); 329 si->ksi_flags |= KSI_PTRACE; 330 } 331 if (SIGISMEMBER(sq->sq_kill, signo)) { 332 count++; 333 if (count == 1) 334 SIGDELSET(sq->sq_kill, signo); 335 } 336 337 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 338 if (ksi->ksi_signo == signo) { 339 if (count == 0) { 340 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 341 ksi->ksi_sigq = NULL; 342 ksiginfo_copy(ksi, si); 343 if (ksiginfo_tryfree(ksi) && p != NULL) 344 p->p_pendingcnt--; 345 } 346 if (++count > 1) 347 break; 348 } 349 } 350 351 if (count <= 1) 352 SIGDELSET(sq->sq_signals, signo); 353 si->ksi_signo = signo; 354 return (signo); 355 } 356 357 void 358 sigqueue_take(ksiginfo_t *ksi) 359 { 360 struct ksiginfo *kp; 361 struct proc *p; 362 sigqueue_t *sq; 363 364 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 365 return; 366 367 p = sq->sq_proc; 368 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 369 ksi->ksi_sigq = NULL; 370 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 371 p->p_pendingcnt--; 372 373 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 374 kp = TAILQ_NEXT(kp, ksi_link)) { 375 if (kp->ksi_signo == ksi->ksi_signo) 376 break; 377 } 378 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 379 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 380 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 381 } 382 383 static int 384 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 385 { 386 struct proc *p = sq->sq_proc; 387 struct ksiginfo *ksi; 388 int ret = 0; 389 390 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 391 392 /* 393 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 394 * for these signals. 395 */ 396 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 397 SIGADDSET(sq->sq_kill, signo); 398 goto out_set_bit; 399 } 400 401 /* directly insert the ksi, don't copy it */ 402 if (si->ksi_flags & KSI_INS) { 403 if (si->ksi_flags & KSI_HEAD) 404 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 405 else 406 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 407 si->ksi_sigq = sq; 408 goto out_set_bit; 409 } 410 411 if (__predict_false(ksiginfo_zone == NULL)) { 412 SIGADDSET(sq->sq_kill, signo); 413 goto out_set_bit; 414 } 415 416 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 417 signal_overflow++; 418 ret = EAGAIN; 419 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 420 signal_alloc_fail++; 421 ret = EAGAIN; 422 } else { 423 if (p != NULL) 424 p->p_pendingcnt++; 425 ksiginfo_copy(si, ksi); 426 ksi->ksi_signo = signo; 427 if (si->ksi_flags & KSI_HEAD) 428 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 429 else 430 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 431 ksi->ksi_sigq = sq; 432 } 433 434 if (ret != 0) { 435 if ((si->ksi_flags & KSI_PTRACE) != 0) { 436 SIGADDSET(sq->sq_ptrace, signo); 437 ret = 0; 438 goto out_set_bit; 439 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 440 (si->ksi_flags & KSI_SIGQ) == 0) { 441 SIGADDSET(sq->sq_kill, signo); 442 ret = 0; 443 goto out_set_bit; 444 } 445 return (ret); 446 } 447 448 out_set_bit: 449 SIGADDSET(sq->sq_signals, signo); 450 return (ret); 451 } 452 453 void 454 sigqueue_flush(sigqueue_t *sq) 455 { 456 struct proc *p = sq->sq_proc; 457 ksiginfo_t *ksi; 458 459 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 460 461 if (p != NULL) 462 PROC_LOCK_ASSERT(p, MA_OWNED); 463 464 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 465 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 466 ksi->ksi_sigq = NULL; 467 if (ksiginfo_tryfree(ksi) && p != NULL) 468 p->p_pendingcnt--; 469 } 470 471 SIGEMPTYSET(sq->sq_signals); 472 SIGEMPTYSET(sq->sq_kill); 473 SIGEMPTYSET(sq->sq_ptrace); 474 } 475 476 static void 477 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 478 { 479 sigset_t tmp; 480 struct proc *p1, *p2; 481 ksiginfo_t *ksi, *next; 482 483 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 484 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 485 p1 = src->sq_proc; 486 p2 = dst->sq_proc; 487 /* Move siginfo to target list */ 488 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 489 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 490 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 491 if (p1 != NULL) 492 p1->p_pendingcnt--; 493 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 494 ksi->ksi_sigq = dst; 495 if (p2 != NULL) 496 p2->p_pendingcnt++; 497 } 498 } 499 500 /* Move pending bits to target list */ 501 tmp = src->sq_kill; 502 SIGSETAND(tmp, *set); 503 SIGSETOR(dst->sq_kill, tmp); 504 SIGSETNAND(src->sq_kill, tmp); 505 506 tmp = src->sq_ptrace; 507 SIGSETAND(tmp, *set); 508 SIGSETOR(dst->sq_ptrace, tmp); 509 SIGSETNAND(src->sq_ptrace, tmp); 510 511 tmp = src->sq_signals; 512 SIGSETAND(tmp, *set); 513 SIGSETOR(dst->sq_signals, tmp); 514 SIGSETNAND(src->sq_signals, tmp); 515 } 516 517 #if 0 518 static void 519 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 520 { 521 sigset_t set; 522 523 SIGEMPTYSET(set); 524 SIGADDSET(set, signo); 525 sigqueue_move_set(src, dst, &set); 526 } 527 #endif 528 529 static void 530 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 531 { 532 struct proc *p = sq->sq_proc; 533 ksiginfo_t *ksi, *next; 534 535 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 536 537 /* Remove siginfo queue */ 538 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 539 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 540 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 541 ksi->ksi_sigq = NULL; 542 if (ksiginfo_tryfree(ksi) && p != NULL) 543 p->p_pendingcnt--; 544 } 545 } 546 SIGSETNAND(sq->sq_kill, *set); 547 SIGSETNAND(sq->sq_ptrace, *set); 548 SIGSETNAND(sq->sq_signals, *set); 549 } 550 551 void 552 sigqueue_delete(sigqueue_t *sq, int signo) 553 { 554 sigset_t set; 555 556 SIGEMPTYSET(set); 557 SIGADDSET(set, signo); 558 sigqueue_delete_set(sq, &set); 559 } 560 561 /* Remove a set of signals for a process */ 562 static void 563 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 564 { 565 sigqueue_t worklist; 566 struct thread *td0; 567 568 PROC_LOCK_ASSERT(p, MA_OWNED); 569 570 sigqueue_init(&worklist, NULL); 571 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 572 573 FOREACH_THREAD_IN_PROC(p, td0) 574 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 575 576 sigqueue_flush(&worklist); 577 } 578 579 void 580 sigqueue_delete_proc(struct proc *p, int signo) 581 { 582 sigset_t set; 583 584 SIGEMPTYSET(set); 585 SIGADDSET(set, signo); 586 sigqueue_delete_set_proc(p, &set); 587 } 588 589 static void 590 sigqueue_delete_stopmask_proc(struct proc *p) 591 { 592 sigset_t set; 593 594 SIGEMPTYSET(set); 595 SIGADDSET(set, SIGSTOP); 596 SIGADDSET(set, SIGTSTP); 597 SIGADDSET(set, SIGTTIN); 598 SIGADDSET(set, SIGTTOU); 599 sigqueue_delete_set_proc(p, &set); 600 } 601 602 /* 603 * Determine signal that should be delivered to thread td, the current 604 * thread, 0 if none. If there is a pending stop signal with default 605 * action, the process stops in issignal(). 606 */ 607 int 608 cursig(struct thread *td) 609 { 610 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 611 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 612 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 613 return (SIGPENDING(td) ? issignal(td) : 0); 614 } 615 616 /* 617 * Arrange for ast() to handle unmasked pending signals on return to user 618 * mode. This must be called whenever a signal is added to td_sigqueue or 619 * unmasked in td_sigmask. 620 */ 621 void 622 signotify(struct thread *td) 623 { 624 625 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 626 627 if (SIGPENDING(td)) { 628 thread_lock(td); 629 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 630 thread_unlock(td); 631 } 632 } 633 634 /* 635 * Returns 1 (true) if altstack is configured for the thread, and the 636 * passed stack bottom address falls into the altstack range. Handles 637 * the 43 compat special case where the alt stack size is zero. 638 */ 639 int 640 sigonstack(size_t sp) 641 { 642 struct thread *td; 643 644 td = curthread; 645 if ((td->td_pflags & TDP_ALTSTACK) == 0) 646 return (0); 647 #if defined(COMPAT_43) 648 if (SV_PROC_FLAG(td->td_proc, SV_AOUT) && td->td_sigstk.ss_size == 0) 649 return ((td->td_sigstk.ss_flags & SS_ONSTACK) != 0); 650 #endif 651 return (sp >= (size_t)td->td_sigstk.ss_sp && 652 sp < td->td_sigstk.ss_size + (size_t)td->td_sigstk.ss_sp); 653 } 654 655 static __inline int 656 sigprop(int sig) 657 { 658 659 if (sig > 0 && sig < nitems(sigproptbl)) 660 return (sigproptbl[sig]); 661 return (0); 662 } 663 664 int 665 sig_ffs(sigset_t *set) 666 { 667 int i; 668 669 for (i = 0; i < _SIG_WORDS; i++) 670 if (set->__bits[i]) 671 return (ffs(set->__bits[i]) + (i * 32)); 672 return (0); 673 } 674 675 static bool 676 sigact_flag_test(const struct sigaction *act, int flag) 677 { 678 679 /* 680 * SA_SIGINFO is reset when signal disposition is set to 681 * ignore or default. Other flags are kept according to user 682 * settings. 683 */ 684 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 685 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 686 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 687 } 688 689 /* 690 * kern_sigaction 691 * sigaction 692 * freebsd4_sigaction 693 * osigaction 694 */ 695 int 696 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 697 struct sigaction *oact, int flags) 698 { 699 struct sigacts *ps; 700 struct proc *p = td->td_proc; 701 702 if (!_SIG_VALID(sig)) 703 return (EINVAL); 704 if (act != NULL && act->sa_handler != SIG_DFL && 705 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 706 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 707 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 708 return (EINVAL); 709 710 PROC_LOCK(p); 711 ps = p->p_sigacts; 712 mtx_lock(&ps->ps_mtx); 713 if (oact) { 714 memset(oact, 0, sizeof(*oact)); 715 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 716 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 717 oact->sa_flags |= SA_ONSTACK; 718 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 719 oact->sa_flags |= SA_RESTART; 720 if (SIGISMEMBER(ps->ps_sigreset, sig)) 721 oact->sa_flags |= SA_RESETHAND; 722 if (SIGISMEMBER(ps->ps_signodefer, sig)) 723 oact->sa_flags |= SA_NODEFER; 724 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 725 oact->sa_flags |= SA_SIGINFO; 726 oact->sa_sigaction = 727 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 728 } else 729 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 730 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 731 oact->sa_flags |= SA_NOCLDSTOP; 732 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 733 oact->sa_flags |= SA_NOCLDWAIT; 734 } 735 if (act) { 736 if ((sig == SIGKILL || sig == SIGSTOP) && 737 act->sa_handler != SIG_DFL) { 738 mtx_unlock(&ps->ps_mtx); 739 PROC_UNLOCK(p); 740 return (EINVAL); 741 } 742 743 /* 744 * Change setting atomically. 745 */ 746 747 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 748 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 749 if (sigact_flag_test(act, SA_SIGINFO)) { 750 ps->ps_sigact[_SIG_IDX(sig)] = 751 (__sighandler_t *)act->sa_sigaction; 752 SIGADDSET(ps->ps_siginfo, sig); 753 } else { 754 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 755 SIGDELSET(ps->ps_siginfo, sig); 756 } 757 if (!sigact_flag_test(act, SA_RESTART)) 758 SIGADDSET(ps->ps_sigintr, sig); 759 else 760 SIGDELSET(ps->ps_sigintr, sig); 761 if (sigact_flag_test(act, SA_ONSTACK)) 762 SIGADDSET(ps->ps_sigonstack, sig); 763 else 764 SIGDELSET(ps->ps_sigonstack, sig); 765 if (sigact_flag_test(act, SA_RESETHAND)) 766 SIGADDSET(ps->ps_sigreset, sig); 767 else 768 SIGDELSET(ps->ps_sigreset, sig); 769 if (sigact_flag_test(act, SA_NODEFER)) 770 SIGADDSET(ps->ps_signodefer, sig); 771 else 772 SIGDELSET(ps->ps_signodefer, sig); 773 if (sig == SIGCHLD) { 774 if (act->sa_flags & SA_NOCLDSTOP) 775 ps->ps_flag |= PS_NOCLDSTOP; 776 else 777 ps->ps_flag &= ~PS_NOCLDSTOP; 778 if (act->sa_flags & SA_NOCLDWAIT) { 779 /* 780 * Paranoia: since SA_NOCLDWAIT is implemented 781 * by reparenting the dying child to PID 1 (and 782 * trust it to reap the zombie), PID 1 itself 783 * is forbidden to set SA_NOCLDWAIT. 784 */ 785 if (p->p_pid == 1) 786 ps->ps_flag &= ~PS_NOCLDWAIT; 787 else 788 ps->ps_flag |= PS_NOCLDWAIT; 789 } else 790 ps->ps_flag &= ~PS_NOCLDWAIT; 791 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 792 ps->ps_flag |= PS_CLDSIGIGN; 793 else 794 ps->ps_flag &= ~PS_CLDSIGIGN; 795 } 796 /* 797 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 798 * and for signals set to SIG_DFL where the default is to 799 * ignore. However, don't put SIGCONT in ps_sigignore, as we 800 * have to restart the process. 801 */ 802 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 803 (sigprop(sig) & SIGPROP_IGNORE && 804 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 805 /* never to be seen again */ 806 sigqueue_delete_proc(p, sig); 807 if (sig != SIGCONT) 808 /* easier in psignal */ 809 SIGADDSET(ps->ps_sigignore, sig); 810 SIGDELSET(ps->ps_sigcatch, sig); 811 } else { 812 SIGDELSET(ps->ps_sigignore, sig); 813 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 814 SIGDELSET(ps->ps_sigcatch, sig); 815 else 816 SIGADDSET(ps->ps_sigcatch, sig); 817 } 818 #ifdef COMPAT_FREEBSD4 819 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 820 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 821 (flags & KSA_FREEBSD4) == 0) 822 SIGDELSET(ps->ps_freebsd4, sig); 823 else 824 SIGADDSET(ps->ps_freebsd4, sig); 825 #endif 826 #ifdef COMPAT_43 827 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 828 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 829 (flags & KSA_OSIGSET) == 0) 830 SIGDELSET(ps->ps_osigset, sig); 831 else 832 SIGADDSET(ps->ps_osigset, sig); 833 #endif 834 } 835 mtx_unlock(&ps->ps_mtx); 836 PROC_UNLOCK(p); 837 return (0); 838 } 839 840 #ifndef _SYS_SYSPROTO_H_ 841 struct sigaction_args { 842 int sig; 843 struct sigaction *act; 844 struct sigaction *oact; 845 }; 846 #endif 847 int 848 sys_sigaction(struct thread *td, struct sigaction_args *uap) 849 { 850 struct sigaction act, oact; 851 struct sigaction *actp, *oactp; 852 int error; 853 854 actp = (uap->act != NULL) ? &act : NULL; 855 oactp = (uap->oact != NULL) ? &oact : NULL; 856 if (actp) { 857 error = copyin(uap->act, actp, sizeof(act)); 858 if (error) 859 return (error); 860 } 861 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 862 if (oactp && !error) 863 error = copyout(oactp, uap->oact, sizeof(oact)); 864 return (error); 865 } 866 867 #ifdef COMPAT_FREEBSD4 868 #ifndef _SYS_SYSPROTO_H_ 869 struct freebsd4_sigaction_args { 870 int sig; 871 struct sigaction *act; 872 struct sigaction *oact; 873 }; 874 #endif 875 int 876 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 877 { 878 struct sigaction act, oact; 879 struct sigaction *actp, *oactp; 880 int error; 881 882 actp = (uap->act != NULL) ? &act : NULL; 883 oactp = (uap->oact != NULL) ? &oact : NULL; 884 if (actp) { 885 error = copyin(uap->act, actp, sizeof(act)); 886 if (error) 887 return (error); 888 } 889 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 890 if (oactp && !error) 891 error = copyout(oactp, uap->oact, sizeof(oact)); 892 return (error); 893 } 894 #endif /* COMAPT_FREEBSD4 */ 895 896 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 897 #ifndef _SYS_SYSPROTO_H_ 898 struct osigaction_args { 899 int signum; 900 struct osigaction *nsa; 901 struct osigaction *osa; 902 }; 903 #endif 904 int 905 osigaction(struct thread *td, struct osigaction_args *uap) 906 { 907 struct osigaction sa; 908 struct sigaction nsa, osa; 909 struct sigaction *nsap, *osap; 910 int error; 911 912 if (uap->signum <= 0 || uap->signum >= ONSIG) 913 return (EINVAL); 914 915 nsap = (uap->nsa != NULL) ? &nsa : NULL; 916 osap = (uap->osa != NULL) ? &osa : NULL; 917 918 if (nsap) { 919 error = copyin(uap->nsa, &sa, sizeof(sa)); 920 if (error) 921 return (error); 922 nsap->sa_handler = sa.sa_handler; 923 nsap->sa_flags = sa.sa_flags; 924 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 925 } 926 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 927 if (osap && !error) { 928 sa.sa_handler = osap->sa_handler; 929 sa.sa_flags = osap->sa_flags; 930 SIG2OSIG(osap->sa_mask, sa.sa_mask); 931 error = copyout(&sa, uap->osa, sizeof(sa)); 932 } 933 return (error); 934 } 935 936 #if !defined(__i386__) 937 /* Avoid replicating the same stub everywhere */ 938 int 939 osigreturn(struct thread *td, struct osigreturn_args *uap) 940 { 941 942 return (nosys(td, (struct nosys_args *)uap)); 943 } 944 #endif 945 #endif /* COMPAT_43 */ 946 947 /* 948 * Initialize signal state for process 0; 949 * set to ignore signals that are ignored by default. 950 */ 951 void 952 siginit(struct proc *p) 953 { 954 int i; 955 struct sigacts *ps; 956 957 PROC_LOCK(p); 958 ps = p->p_sigacts; 959 mtx_lock(&ps->ps_mtx); 960 for (i = 1; i <= NSIG; i++) { 961 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 962 SIGADDSET(ps->ps_sigignore, i); 963 } 964 } 965 mtx_unlock(&ps->ps_mtx); 966 PROC_UNLOCK(p); 967 } 968 969 /* 970 * Reset specified signal to the default disposition. 971 */ 972 static void 973 sigdflt(struct sigacts *ps, int sig) 974 { 975 976 mtx_assert(&ps->ps_mtx, MA_OWNED); 977 SIGDELSET(ps->ps_sigcatch, sig); 978 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 979 SIGADDSET(ps->ps_sigignore, sig); 980 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 981 SIGDELSET(ps->ps_siginfo, sig); 982 } 983 984 /* 985 * Reset signals for an exec of the specified process. 986 */ 987 void 988 execsigs(struct proc *p) 989 { 990 struct sigacts *ps; 991 struct thread *td; 992 993 /* 994 * Reset caught signals. Held signals remain held 995 * through td_sigmask (unless they were caught, 996 * and are now ignored by default). 997 */ 998 PROC_LOCK_ASSERT(p, MA_OWNED); 999 ps = p->p_sigacts; 1000 mtx_lock(&ps->ps_mtx); 1001 sig_drop_caught(p); 1002 1003 /* 1004 * Reset stack state to the user stack. 1005 * Clear set of signals caught on the signal stack. 1006 */ 1007 td = curthread; 1008 MPASS(td->td_proc == p); 1009 td->td_sigstk.ss_flags = SS_DISABLE; 1010 td->td_sigstk.ss_size = 0; 1011 td->td_sigstk.ss_sp = 0; 1012 td->td_pflags &= ~TDP_ALTSTACK; 1013 /* 1014 * Reset no zombies if child dies flag as Solaris does. 1015 */ 1016 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1017 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1018 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1019 mtx_unlock(&ps->ps_mtx); 1020 } 1021 1022 /* 1023 * kern_sigprocmask() 1024 * 1025 * Manipulate signal mask. 1026 */ 1027 int 1028 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1029 int flags) 1030 { 1031 sigset_t new_block, oset1; 1032 struct proc *p; 1033 int error; 1034 1035 p = td->td_proc; 1036 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1037 PROC_LOCK_ASSERT(p, MA_OWNED); 1038 else 1039 PROC_LOCK(p); 1040 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1041 ? MA_OWNED : MA_NOTOWNED); 1042 if (oset != NULL) 1043 *oset = td->td_sigmask; 1044 1045 error = 0; 1046 if (set != NULL) { 1047 switch (how) { 1048 case SIG_BLOCK: 1049 SIG_CANTMASK(*set); 1050 oset1 = td->td_sigmask; 1051 SIGSETOR(td->td_sigmask, *set); 1052 new_block = td->td_sigmask; 1053 SIGSETNAND(new_block, oset1); 1054 break; 1055 case SIG_UNBLOCK: 1056 SIGSETNAND(td->td_sigmask, *set); 1057 signotify(td); 1058 goto out; 1059 case SIG_SETMASK: 1060 SIG_CANTMASK(*set); 1061 oset1 = td->td_sigmask; 1062 if (flags & SIGPROCMASK_OLD) 1063 SIGSETLO(td->td_sigmask, *set); 1064 else 1065 td->td_sigmask = *set; 1066 new_block = td->td_sigmask; 1067 SIGSETNAND(new_block, oset1); 1068 signotify(td); 1069 break; 1070 default: 1071 error = EINVAL; 1072 goto out; 1073 } 1074 1075 /* 1076 * The new_block set contains signals that were not previously 1077 * blocked, but are blocked now. 1078 * 1079 * In case we block any signal that was not previously blocked 1080 * for td, and process has the signal pending, try to schedule 1081 * signal delivery to some thread that does not block the 1082 * signal, possibly waking it up. 1083 */ 1084 if (p->p_numthreads != 1) 1085 reschedule_signals(p, new_block, flags); 1086 } 1087 1088 out: 1089 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1090 PROC_UNLOCK(p); 1091 return (error); 1092 } 1093 1094 #ifndef _SYS_SYSPROTO_H_ 1095 struct sigprocmask_args { 1096 int how; 1097 const sigset_t *set; 1098 sigset_t *oset; 1099 }; 1100 #endif 1101 int 1102 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1103 { 1104 sigset_t set, oset; 1105 sigset_t *setp, *osetp; 1106 int error; 1107 1108 setp = (uap->set != NULL) ? &set : NULL; 1109 osetp = (uap->oset != NULL) ? &oset : NULL; 1110 if (setp) { 1111 error = copyin(uap->set, setp, sizeof(set)); 1112 if (error) 1113 return (error); 1114 } 1115 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1116 if (osetp && !error) { 1117 error = copyout(osetp, uap->oset, sizeof(oset)); 1118 } 1119 return (error); 1120 } 1121 1122 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1123 #ifndef _SYS_SYSPROTO_H_ 1124 struct osigprocmask_args { 1125 int how; 1126 osigset_t mask; 1127 }; 1128 #endif 1129 int 1130 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1131 { 1132 sigset_t set, oset; 1133 int error; 1134 1135 OSIG2SIG(uap->mask, set); 1136 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1137 SIG2OSIG(oset, td->td_retval[0]); 1138 return (error); 1139 } 1140 #endif /* COMPAT_43 */ 1141 1142 int 1143 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1144 { 1145 ksiginfo_t ksi; 1146 sigset_t set; 1147 int error; 1148 1149 error = copyin(uap->set, &set, sizeof(set)); 1150 if (error) { 1151 td->td_retval[0] = error; 1152 return (0); 1153 } 1154 1155 error = kern_sigtimedwait(td, set, &ksi, NULL); 1156 if (error) { 1157 /* 1158 * sigwait() function shall not return EINTR, but 1159 * the syscall does. Non-ancient libc provides the 1160 * wrapper which hides EINTR. Otherwise, EINTR return 1161 * is used by libthr to handle required cancellation 1162 * point in the sigwait(). 1163 */ 1164 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1165 return (ERESTART); 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 bool traced; 1256 1257 p = td->td_proc; 1258 error = 0; 1259 ets.tv_sec = 0; 1260 ets.tv_nsec = 0; 1261 traced = false; 1262 1263 /* Ensure the sigfastblock value is up to date. */ 1264 sigfastblock_fetch(td); 1265 1266 if (timeout != NULL) { 1267 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1268 timevalid = 1; 1269 getnanouptime(&rts); 1270 timespecadd(&rts, timeout, &ets); 1271 } 1272 } 1273 ksiginfo_init(ksi); 1274 /* Some signals can not be waited for. */ 1275 SIG_CANTMASK(waitset); 1276 ps = p->p_sigacts; 1277 PROC_LOCK(p); 1278 saved_mask = td->td_sigmask; 1279 SIGSETNAND(td->td_sigmask, waitset); 1280 if ((p->p_sysent->sv_flags & SV_SIG_DISCIGN) != 0 || 1281 !kern_sig_discard_ign) 1282 td->td_pflags2 |= TDP2_SIGWAIT; 1283 for (;;) { 1284 mtx_lock(&ps->ps_mtx); 1285 sig = cursig(td); 1286 mtx_unlock(&ps->ps_mtx); 1287 KASSERT(sig >= 0, ("sig %d", sig)); 1288 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1289 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1290 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1291 error = 0; 1292 break; 1293 } 1294 } 1295 1296 if (error != 0) 1297 break; 1298 1299 /* 1300 * POSIX says this must be checked after looking for pending 1301 * signals. 1302 */ 1303 if (timeout != NULL) { 1304 if (!timevalid) { 1305 error = EINVAL; 1306 break; 1307 } 1308 getnanouptime(&rts); 1309 if (timespeccmp(&rts, &ets, >=)) { 1310 error = EAGAIN; 1311 break; 1312 } 1313 timespecsub(&ets, &rts, &ts); 1314 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1315 timo = tvtohz(&tv); 1316 } else { 1317 timo = 0; 1318 } 1319 1320 if (traced) { 1321 error = EINTR; 1322 break; 1323 } 1324 1325 error = msleep(&p->p_sigacts, &p->p_mtx, PPAUSE | PCATCH, 1326 "sigwait", timo); 1327 1328 /* The syscalls can not be restarted. */ 1329 if (error == ERESTART) 1330 error = EINTR; 1331 1332 /* We will calculate timeout by ourself. */ 1333 if (timeout != NULL && error == EAGAIN) 1334 error = 0; 1335 1336 /* 1337 * If PTRACE_SCE or PTRACE_SCX were set after 1338 * userspace entered the syscall, return spurious 1339 * EINTR after wait was done. Only do this as last 1340 * resort after rechecking for possible queued signals 1341 * and expired timeouts. 1342 */ 1343 if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0) 1344 traced = true; 1345 } 1346 td->td_pflags2 &= ~TDP2_SIGWAIT; 1347 1348 new_block = saved_mask; 1349 SIGSETNAND(new_block, td->td_sigmask); 1350 td->td_sigmask = saved_mask; 1351 /* 1352 * Fewer signals can be delivered to us, reschedule signal 1353 * notification. 1354 */ 1355 if (p->p_numthreads != 1) 1356 reschedule_signals(p, new_block, 0); 1357 1358 if (error == 0) { 1359 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1360 1361 if (ksi->ksi_code == SI_TIMER) 1362 itimer_accept(p, ksi->ksi_timerid, ksi); 1363 1364 #ifdef KTRACE 1365 if (KTRPOINT(td, KTR_PSIG)) { 1366 sig_t action; 1367 1368 mtx_lock(&ps->ps_mtx); 1369 action = ps->ps_sigact[_SIG_IDX(sig)]; 1370 mtx_unlock(&ps->ps_mtx); 1371 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1372 } 1373 #endif 1374 if (sig == SIGKILL) { 1375 proc_td_siginfo_capture(td, &ksi->ksi_info); 1376 sigexit(td, sig); 1377 } 1378 } 1379 PROC_UNLOCK(p); 1380 return (error); 1381 } 1382 1383 #ifndef _SYS_SYSPROTO_H_ 1384 struct sigpending_args { 1385 sigset_t *set; 1386 }; 1387 #endif 1388 int 1389 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1390 { 1391 struct proc *p = td->td_proc; 1392 sigset_t pending; 1393 1394 PROC_LOCK(p); 1395 pending = p->p_sigqueue.sq_signals; 1396 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1397 PROC_UNLOCK(p); 1398 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1399 } 1400 1401 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1402 #ifndef _SYS_SYSPROTO_H_ 1403 struct osigpending_args { 1404 int dummy; 1405 }; 1406 #endif 1407 int 1408 osigpending(struct thread *td, struct osigpending_args *uap) 1409 { 1410 struct proc *p = td->td_proc; 1411 sigset_t pending; 1412 1413 PROC_LOCK(p); 1414 pending = p->p_sigqueue.sq_signals; 1415 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1416 PROC_UNLOCK(p); 1417 SIG2OSIG(pending, td->td_retval[0]); 1418 return (0); 1419 } 1420 #endif /* COMPAT_43 */ 1421 1422 #if defined(COMPAT_43) 1423 /* 1424 * Generalized interface signal handler, 4.3-compatible. 1425 */ 1426 #ifndef _SYS_SYSPROTO_H_ 1427 struct osigvec_args { 1428 int signum; 1429 struct sigvec *nsv; 1430 struct sigvec *osv; 1431 }; 1432 #endif 1433 /* ARGSUSED */ 1434 int 1435 osigvec(struct thread *td, struct osigvec_args *uap) 1436 { 1437 struct sigvec vec; 1438 struct sigaction nsa, osa; 1439 struct sigaction *nsap, *osap; 1440 int error; 1441 1442 if (uap->signum <= 0 || uap->signum >= ONSIG) 1443 return (EINVAL); 1444 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1445 osap = (uap->osv != NULL) ? &osa : NULL; 1446 if (nsap) { 1447 error = copyin(uap->nsv, &vec, sizeof(vec)); 1448 if (error) 1449 return (error); 1450 nsap->sa_handler = vec.sv_handler; 1451 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1452 nsap->sa_flags = vec.sv_flags; 1453 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1454 } 1455 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1456 if (osap && !error) { 1457 vec.sv_handler = osap->sa_handler; 1458 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1459 vec.sv_flags = osap->sa_flags; 1460 vec.sv_flags &= ~SA_NOCLDWAIT; 1461 vec.sv_flags ^= SA_RESTART; 1462 error = copyout(&vec, uap->osv, sizeof(vec)); 1463 } 1464 return (error); 1465 } 1466 1467 #ifndef _SYS_SYSPROTO_H_ 1468 struct osigblock_args { 1469 int mask; 1470 }; 1471 #endif 1472 int 1473 osigblock(struct thread *td, struct osigblock_args *uap) 1474 { 1475 sigset_t set, oset; 1476 1477 OSIG2SIG(uap->mask, set); 1478 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1479 SIG2OSIG(oset, td->td_retval[0]); 1480 return (0); 1481 } 1482 1483 #ifndef _SYS_SYSPROTO_H_ 1484 struct osigsetmask_args { 1485 int mask; 1486 }; 1487 #endif 1488 int 1489 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1490 { 1491 sigset_t set, oset; 1492 1493 OSIG2SIG(uap->mask, set); 1494 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1495 SIG2OSIG(oset, td->td_retval[0]); 1496 return (0); 1497 } 1498 #endif /* COMPAT_43 */ 1499 1500 /* 1501 * Suspend calling thread until signal, providing mask to be set in the 1502 * meantime. 1503 */ 1504 #ifndef _SYS_SYSPROTO_H_ 1505 struct sigsuspend_args { 1506 const sigset_t *sigmask; 1507 }; 1508 #endif 1509 /* ARGSUSED */ 1510 int 1511 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1512 { 1513 sigset_t mask; 1514 int error; 1515 1516 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1517 if (error) 1518 return (error); 1519 return (kern_sigsuspend(td, mask)); 1520 } 1521 1522 int 1523 kern_sigsuspend(struct thread *td, sigset_t mask) 1524 { 1525 struct proc *p = td->td_proc; 1526 int has_sig, sig; 1527 1528 /* Ensure the sigfastblock value is up to date. */ 1529 sigfastblock_fetch(td); 1530 1531 /* 1532 * When returning from sigsuspend, we want 1533 * the old mask to be restored after the 1534 * signal handler has finished. Thus, we 1535 * save it here and mark the sigacts structure 1536 * to indicate this. 1537 */ 1538 PROC_LOCK(p); 1539 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1540 SIGPROCMASK_PROC_LOCKED); 1541 td->td_pflags |= TDP_OLDMASK; 1542 1543 /* 1544 * Process signals now. Otherwise, we can get spurious wakeup 1545 * due to signal entered process queue, but delivered to other 1546 * thread. But sigsuspend should return only on signal 1547 * delivery. 1548 */ 1549 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1550 for (has_sig = 0; !has_sig;) { 1551 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1552 0) == 0) 1553 /* void */; 1554 thread_suspend_check(0); 1555 mtx_lock(&p->p_sigacts->ps_mtx); 1556 while ((sig = cursig(td)) != 0) { 1557 KASSERT(sig >= 0, ("sig %d", sig)); 1558 has_sig += postsig(sig); 1559 } 1560 mtx_unlock(&p->p_sigacts->ps_mtx); 1561 1562 /* 1563 * If PTRACE_SCE or PTRACE_SCX were set after 1564 * userspace entered the syscall, return spurious 1565 * EINTR. 1566 */ 1567 if ((p->p_ptevents & PTRACE_SYSCALL) != 0) 1568 has_sig += 1; 1569 } 1570 PROC_UNLOCK(p); 1571 td->td_errno = EINTR; 1572 td->td_pflags |= TDP_NERRNO; 1573 return (EJUSTRETURN); 1574 } 1575 1576 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1577 /* 1578 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1579 * convention: libc stub passes mask, not pointer, to save a copyin. 1580 */ 1581 #ifndef _SYS_SYSPROTO_H_ 1582 struct osigsuspend_args { 1583 osigset_t mask; 1584 }; 1585 #endif 1586 /* ARGSUSED */ 1587 int 1588 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1589 { 1590 sigset_t mask; 1591 1592 OSIG2SIG(uap->mask, mask); 1593 return (kern_sigsuspend(td, mask)); 1594 } 1595 #endif /* COMPAT_43 */ 1596 1597 #if defined(COMPAT_43) 1598 #ifndef _SYS_SYSPROTO_H_ 1599 struct osigstack_args { 1600 struct sigstack *nss; 1601 struct sigstack *oss; 1602 }; 1603 #endif 1604 /* ARGSUSED */ 1605 int 1606 osigstack(struct thread *td, struct osigstack_args *uap) 1607 { 1608 struct sigstack nss, oss; 1609 int error = 0; 1610 1611 if (uap->nss != NULL) { 1612 error = copyin(uap->nss, &nss, sizeof(nss)); 1613 if (error) 1614 return (error); 1615 } 1616 oss.ss_sp = td->td_sigstk.ss_sp; 1617 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1618 if (uap->nss != NULL) { 1619 td->td_sigstk.ss_sp = nss.ss_sp; 1620 td->td_sigstk.ss_size = 0; 1621 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1622 td->td_pflags |= TDP_ALTSTACK; 1623 } 1624 if (uap->oss != NULL) 1625 error = copyout(&oss, uap->oss, sizeof(oss)); 1626 1627 return (error); 1628 } 1629 #endif /* COMPAT_43 */ 1630 1631 #ifndef _SYS_SYSPROTO_H_ 1632 struct sigaltstack_args { 1633 stack_t *ss; 1634 stack_t *oss; 1635 }; 1636 #endif 1637 /* ARGSUSED */ 1638 int 1639 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1640 { 1641 stack_t ss, oss; 1642 int error; 1643 1644 if (uap->ss != NULL) { 1645 error = copyin(uap->ss, &ss, sizeof(ss)); 1646 if (error) 1647 return (error); 1648 } 1649 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1650 (uap->oss != NULL) ? &oss : NULL); 1651 if (error) 1652 return (error); 1653 if (uap->oss != NULL) 1654 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1655 return (error); 1656 } 1657 1658 int 1659 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1660 { 1661 struct proc *p = td->td_proc; 1662 int oonstack; 1663 1664 oonstack = sigonstack(cpu_getstack(td)); 1665 1666 if (oss != NULL) { 1667 *oss = td->td_sigstk; 1668 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1669 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1670 } 1671 1672 if (ss != NULL) { 1673 if (oonstack) 1674 return (EPERM); 1675 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1676 return (EINVAL); 1677 if (!(ss->ss_flags & SS_DISABLE)) { 1678 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1679 return (ENOMEM); 1680 1681 td->td_sigstk = *ss; 1682 td->td_pflags |= TDP_ALTSTACK; 1683 } else { 1684 td->td_pflags &= ~TDP_ALTSTACK; 1685 } 1686 } 1687 return (0); 1688 } 1689 1690 struct killpg1_ctx { 1691 struct thread *td; 1692 ksiginfo_t *ksi; 1693 int sig; 1694 bool sent; 1695 bool found; 1696 int ret; 1697 }; 1698 1699 static void 1700 killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg) 1701 { 1702 int err; 1703 1704 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 || 1705 (notself && p == arg->td->td_proc) || p->p_state == PRS_NEW) 1706 return; 1707 PROC_LOCK(p); 1708 err = p_cansignal(arg->td, p, arg->sig); 1709 if (err == 0 && arg->sig != 0) 1710 pksignal(p, arg->sig, arg->ksi); 1711 PROC_UNLOCK(p); 1712 if (err != ESRCH) 1713 arg->found = true; 1714 if (err == 0) 1715 arg->sent = true; 1716 else if (arg->ret == 0 && err != ESRCH && err != EPERM) 1717 arg->ret = err; 1718 } 1719 1720 /* 1721 * Common code for kill process group/broadcast kill. 1722 * cp is calling process. 1723 */ 1724 static int 1725 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1726 { 1727 struct proc *p; 1728 struct pgrp *pgrp; 1729 struct killpg1_ctx arg; 1730 1731 arg.td = td; 1732 arg.ksi = ksi; 1733 arg.sig = sig; 1734 arg.sent = false; 1735 arg.found = false; 1736 arg.ret = 0; 1737 if (all) { 1738 /* 1739 * broadcast 1740 */ 1741 sx_slock(&allproc_lock); 1742 FOREACH_PROC_IN_SYSTEM(p) { 1743 killpg1_sendsig(p, true, &arg); 1744 } 1745 sx_sunlock(&allproc_lock); 1746 } else { 1747 sx_slock(&proctree_lock); 1748 if (pgid == 0) { 1749 /* 1750 * zero pgid means send to my process group. 1751 */ 1752 pgrp = td->td_proc->p_pgrp; 1753 PGRP_LOCK(pgrp); 1754 } else { 1755 pgrp = pgfind(pgid); 1756 if (pgrp == NULL) { 1757 sx_sunlock(&proctree_lock); 1758 return (ESRCH); 1759 } 1760 } 1761 sx_sunlock(&proctree_lock); 1762 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1763 killpg1_sendsig(p, false, &arg); 1764 } 1765 PGRP_UNLOCK(pgrp); 1766 } 1767 MPASS(arg.ret != 0 || arg.found || !arg.sent); 1768 if (arg.ret == 0 && !arg.sent) 1769 arg.ret = arg.found ? EPERM : ESRCH; 1770 return (arg.ret); 1771 } 1772 1773 #ifndef _SYS_SYSPROTO_H_ 1774 struct kill_args { 1775 int pid; 1776 int signum; 1777 }; 1778 #endif 1779 /* ARGSUSED */ 1780 int 1781 sys_kill(struct thread *td, struct kill_args *uap) 1782 { 1783 1784 return (kern_kill(td, uap->pid, uap->signum)); 1785 } 1786 1787 int 1788 kern_kill(struct thread *td, pid_t pid, int signum) 1789 { 1790 ksiginfo_t ksi; 1791 struct proc *p; 1792 int error; 1793 1794 /* 1795 * A process in capability mode can send signals only to himself. 1796 * The main rationale behind this is that abort(3) is implemented as 1797 * kill(getpid(), SIGABRT). 1798 */ 1799 if (IN_CAPABILITY_MODE(td) && pid != td->td_proc->p_pid) 1800 return (ECAPMODE); 1801 1802 AUDIT_ARG_SIGNUM(signum); 1803 AUDIT_ARG_PID(pid); 1804 if ((u_int)signum > _SIG_MAXSIG) 1805 return (EINVAL); 1806 1807 ksiginfo_init(&ksi); 1808 ksi.ksi_signo = signum; 1809 ksi.ksi_code = SI_USER; 1810 ksi.ksi_pid = td->td_proc->p_pid; 1811 ksi.ksi_uid = td->td_ucred->cr_ruid; 1812 1813 if (pid > 0) { 1814 /* kill single process */ 1815 if ((p = pfind_any(pid)) == NULL) 1816 return (ESRCH); 1817 AUDIT_ARG_PROCESS(p); 1818 error = p_cansignal(td, p, signum); 1819 if (error == 0 && signum) 1820 pksignal(p, signum, &ksi); 1821 PROC_UNLOCK(p); 1822 return (error); 1823 } 1824 switch (pid) { 1825 case -1: /* broadcast signal */ 1826 return (killpg1(td, signum, 0, 1, &ksi)); 1827 case 0: /* signal own process group */ 1828 return (killpg1(td, signum, 0, 0, &ksi)); 1829 default: /* negative explicit process group */ 1830 return (killpg1(td, signum, -pid, 0, &ksi)); 1831 } 1832 /* NOTREACHED */ 1833 } 1834 1835 int 1836 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1837 { 1838 struct proc *p; 1839 int error; 1840 1841 AUDIT_ARG_SIGNUM(uap->signum); 1842 AUDIT_ARG_FD(uap->fd); 1843 if ((u_int)uap->signum > _SIG_MAXSIG) 1844 return (EINVAL); 1845 1846 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1847 if (error) 1848 return (error); 1849 AUDIT_ARG_PROCESS(p); 1850 error = p_cansignal(td, p, uap->signum); 1851 if (error == 0 && uap->signum) 1852 kern_psignal(p, uap->signum); 1853 PROC_UNLOCK(p); 1854 return (error); 1855 } 1856 1857 #if defined(COMPAT_43) 1858 #ifndef _SYS_SYSPROTO_H_ 1859 struct okillpg_args { 1860 int pgid; 1861 int signum; 1862 }; 1863 #endif 1864 /* ARGSUSED */ 1865 int 1866 okillpg(struct thread *td, struct okillpg_args *uap) 1867 { 1868 ksiginfo_t ksi; 1869 1870 AUDIT_ARG_SIGNUM(uap->signum); 1871 AUDIT_ARG_PID(uap->pgid); 1872 if ((u_int)uap->signum > _SIG_MAXSIG) 1873 return (EINVAL); 1874 1875 ksiginfo_init(&ksi); 1876 ksi.ksi_signo = uap->signum; 1877 ksi.ksi_code = SI_USER; 1878 ksi.ksi_pid = td->td_proc->p_pid; 1879 ksi.ksi_uid = td->td_ucred->cr_ruid; 1880 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1881 } 1882 #endif /* COMPAT_43 */ 1883 1884 #ifndef _SYS_SYSPROTO_H_ 1885 struct sigqueue_args { 1886 pid_t pid; 1887 int signum; 1888 /* union sigval */ void *value; 1889 }; 1890 #endif 1891 int 1892 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1893 { 1894 union sigval sv; 1895 1896 sv.sival_ptr = uap->value; 1897 1898 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1899 } 1900 1901 int 1902 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1903 { 1904 ksiginfo_t ksi; 1905 struct proc *p; 1906 int error; 1907 1908 if ((u_int)signum > _SIG_MAXSIG) 1909 return (EINVAL); 1910 1911 /* 1912 * Specification says sigqueue can only send signal to 1913 * single process. 1914 */ 1915 if (pid <= 0) 1916 return (EINVAL); 1917 1918 if ((p = pfind_any(pid)) == NULL) 1919 return (ESRCH); 1920 error = p_cansignal(td, p, signum); 1921 if (error == 0 && signum != 0) { 1922 ksiginfo_init(&ksi); 1923 ksi.ksi_flags = KSI_SIGQ; 1924 ksi.ksi_signo = signum; 1925 ksi.ksi_code = SI_QUEUE; 1926 ksi.ksi_pid = td->td_proc->p_pid; 1927 ksi.ksi_uid = td->td_ucred->cr_ruid; 1928 ksi.ksi_value = *value; 1929 error = pksignal(p, ksi.ksi_signo, &ksi); 1930 } 1931 PROC_UNLOCK(p); 1932 return (error); 1933 } 1934 1935 /* 1936 * Send a signal to a process group. 1937 */ 1938 void 1939 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1940 { 1941 struct pgrp *pgrp; 1942 1943 if (pgid != 0) { 1944 sx_slock(&proctree_lock); 1945 pgrp = pgfind(pgid); 1946 sx_sunlock(&proctree_lock); 1947 if (pgrp != NULL) { 1948 pgsignal(pgrp, sig, 0, ksi); 1949 PGRP_UNLOCK(pgrp); 1950 } 1951 } 1952 } 1953 1954 /* 1955 * Send a signal to a process group. If checktty is 1, 1956 * limit to members which have a controlling terminal. 1957 */ 1958 void 1959 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1960 { 1961 struct proc *p; 1962 1963 if (pgrp) { 1964 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1965 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1966 PROC_LOCK(p); 1967 if (p->p_state == PRS_NORMAL && 1968 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1969 pksignal(p, sig, ksi); 1970 PROC_UNLOCK(p); 1971 } 1972 } 1973 } 1974 1975 /* 1976 * Recalculate the signal mask and reset the signal disposition after 1977 * usermode frame for delivery is formed. Should be called after 1978 * mach-specific routine, because sysent->sv_sendsig() needs correct 1979 * ps_siginfo and signal mask. 1980 */ 1981 static void 1982 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1983 { 1984 sigset_t mask; 1985 1986 mtx_assert(&ps->ps_mtx, MA_OWNED); 1987 td->td_ru.ru_nsignals++; 1988 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1989 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1990 SIGADDSET(mask, sig); 1991 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1992 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1993 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1994 sigdflt(ps, sig); 1995 } 1996 1997 /* 1998 * Send a signal caused by a trap to the current thread. If it will be 1999 * caught immediately, deliver it with correct code. Otherwise, post it 2000 * normally. 2001 */ 2002 void 2003 trapsignal(struct thread *td, ksiginfo_t *ksi) 2004 { 2005 struct sigacts *ps; 2006 struct proc *p; 2007 sigset_t sigmask; 2008 int code, sig; 2009 2010 p = td->td_proc; 2011 sig = ksi->ksi_signo; 2012 code = ksi->ksi_code; 2013 KASSERT(_SIG_VALID(sig), ("invalid signal")); 2014 2015 sigfastblock_fetch(td); 2016 PROC_LOCK(p); 2017 ps = p->p_sigacts; 2018 mtx_lock(&ps->ps_mtx); 2019 sigmask = td->td_sigmask; 2020 if (td->td_sigblock_val != 0) 2021 SIGSETOR(sigmask, fastblock_mask); 2022 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 2023 !SIGISMEMBER(sigmask, sig)) { 2024 #ifdef KTRACE 2025 if (KTRPOINT(curthread, KTR_PSIG)) 2026 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 2027 &td->td_sigmask, code); 2028 #endif 2029 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 2030 ksi, &td->td_sigmask); 2031 postsig_done(sig, td, ps); 2032 mtx_unlock(&ps->ps_mtx); 2033 } else { 2034 /* 2035 * Avoid a possible infinite loop if the thread 2036 * masking the signal or process is ignoring the 2037 * signal. 2038 */ 2039 if (kern_forcesigexit && (SIGISMEMBER(sigmask, sig) || 2040 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2041 SIGDELSET(td->td_sigmask, sig); 2042 SIGDELSET(ps->ps_sigcatch, sig); 2043 SIGDELSET(ps->ps_sigignore, sig); 2044 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2045 td->td_pflags &= ~TDP_SIGFASTBLOCK; 2046 td->td_sigblock_val = 0; 2047 } 2048 mtx_unlock(&ps->ps_mtx); 2049 p->p_sig = sig; /* XXX to verify code */ 2050 tdsendsignal(p, td, sig, ksi); 2051 } 2052 PROC_UNLOCK(p); 2053 } 2054 2055 static struct thread * 2056 sigtd(struct proc *p, int sig, bool fast_sigblock) 2057 { 2058 struct thread *td, *signal_td; 2059 2060 PROC_LOCK_ASSERT(p, MA_OWNED); 2061 MPASS(!fast_sigblock || p == curproc); 2062 2063 /* 2064 * Check if current thread can handle the signal without 2065 * switching context to another thread. 2066 */ 2067 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig) && 2068 (!fast_sigblock || curthread->td_sigblock_val == 0)) 2069 return (curthread); 2070 signal_td = NULL; 2071 FOREACH_THREAD_IN_PROC(p, td) { 2072 if (!SIGISMEMBER(td->td_sigmask, sig) && (!fast_sigblock || 2073 td != curthread || td->td_sigblock_val == 0)) { 2074 signal_td = td; 2075 break; 2076 } 2077 } 2078 if (signal_td == NULL) 2079 signal_td = FIRST_THREAD_IN_PROC(p); 2080 return (signal_td); 2081 } 2082 2083 /* 2084 * Send the signal to the process. If the signal has an action, the action 2085 * is usually performed by the target process rather than the caller; we add 2086 * the signal to the set of pending signals for the process. 2087 * 2088 * Exceptions: 2089 * o When a stop signal is sent to a sleeping process that takes the 2090 * default action, the process is stopped without awakening it. 2091 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2092 * regardless of the signal action (eg, blocked or ignored). 2093 * 2094 * Other ignored signals are discarded immediately. 2095 * 2096 * NB: This function may be entered from the debugger via the "kill" DDB 2097 * command. There is little that can be done to mitigate the possibly messy 2098 * side effects of this unwise possibility. 2099 */ 2100 void 2101 kern_psignal(struct proc *p, int sig) 2102 { 2103 ksiginfo_t ksi; 2104 2105 ksiginfo_init(&ksi); 2106 ksi.ksi_signo = sig; 2107 ksi.ksi_code = SI_KERNEL; 2108 (void) tdsendsignal(p, NULL, sig, &ksi); 2109 } 2110 2111 int 2112 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2113 { 2114 2115 return (tdsendsignal(p, NULL, sig, ksi)); 2116 } 2117 2118 /* Utility function for finding a thread to send signal event to. */ 2119 int 2120 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2121 { 2122 struct thread *td; 2123 2124 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2125 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2126 if (td == NULL) 2127 return (ESRCH); 2128 *ttd = td; 2129 } else { 2130 *ttd = NULL; 2131 PROC_LOCK(p); 2132 } 2133 return (0); 2134 } 2135 2136 void 2137 tdsignal(struct thread *td, int sig) 2138 { 2139 ksiginfo_t ksi; 2140 2141 ksiginfo_init(&ksi); 2142 ksi.ksi_signo = sig; 2143 ksi.ksi_code = SI_KERNEL; 2144 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2145 } 2146 2147 void 2148 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2149 { 2150 2151 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2152 } 2153 2154 int 2155 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2156 { 2157 sig_t action; 2158 sigqueue_t *sigqueue; 2159 int prop; 2160 struct sigacts *ps; 2161 int intrval; 2162 int ret = 0; 2163 int wakeup_swapper; 2164 2165 MPASS(td == NULL || p == td->td_proc); 2166 PROC_LOCK_ASSERT(p, MA_OWNED); 2167 2168 if (!_SIG_VALID(sig)) 2169 panic("%s(): invalid signal %d", __func__, sig); 2170 2171 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2172 2173 /* 2174 * IEEE Std 1003.1-2001: return success when killing a zombie. 2175 */ 2176 if (p->p_state == PRS_ZOMBIE) { 2177 if (ksi && (ksi->ksi_flags & KSI_INS)) 2178 ksiginfo_tryfree(ksi); 2179 return (ret); 2180 } 2181 2182 ps = p->p_sigacts; 2183 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2184 prop = sigprop(sig); 2185 2186 if (td == NULL) { 2187 td = sigtd(p, sig, false); 2188 sigqueue = &p->p_sigqueue; 2189 } else 2190 sigqueue = &td->td_sigqueue; 2191 2192 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2193 2194 /* 2195 * If the signal is being ignored, then we forget about it 2196 * immediately, except when the target process executes 2197 * sigwait(). (Note: we don't set SIGCONT in ps_sigignore, 2198 * and if it is set to SIG_IGN, action will be SIG_DFL here.) 2199 */ 2200 mtx_lock(&ps->ps_mtx); 2201 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2202 if (kern_sig_discard_ign && 2203 (p->p_sysent->sv_flags & SV_SIG_DISCIGN) == 0) { 2204 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2205 2206 mtx_unlock(&ps->ps_mtx); 2207 if (ksi && (ksi->ksi_flags & KSI_INS)) 2208 ksiginfo_tryfree(ksi); 2209 return (ret); 2210 } else { 2211 action = SIG_CATCH; 2212 } 2213 } else if (SIGISMEMBER(td->td_sigmask, sig)) 2214 action = SIG_HOLD; 2215 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2216 action = SIG_CATCH; 2217 else 2218 action = SIG_DFL; 2219 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2220 intrval = EINTR; 2221 else 2222 intrval = ERESTART; 2223 mtx_unlock(&ps->ps_mtx); 2224 2225 if (prop & SIGPROP_CONT) 2226 sigqueue_delete_stopmask_proc(p); 2227 else if (prop & SIGPROP_STOP) { 2228 /* 2229 * If sending a tty stop signal to a member of an orphaned 2230 * process group, discard the signal here if the action 2231 * is default; don't stop the process below if sleeping, 2232 * and don't clear any pending SIGCONT. 2233 */ 2234 if ((prop & SIGPROP_TTYSTOP) != 0 && 2235 (p->p_pgrp->pg_flags & PGRP_ORPHANED) != 0 && 2236 action == SIG_DFL) { 2237 if (ksi && (ksi->ksi_flags & KSI_INS)) 2238 ksiginfo_tryfree(ksi); 2239 return (ret); 2240 } 2241 sigqueue_delete_proc(p, SIGCONT); 2242 if (p->p_flag & P_CONTINUED) { 2243 p->p_flag &= ~P_CONTINUED; 2244 PROC_LOCK(p->p_pptr); 2245 sigqueue_take(p->p_ksi); 2246 PROC_UNLOCK(p->p_pptr); 2247 } 2248 } 2249 2250 ret = sigqueue_add(sigqueue, sig, ksi); 2251 if (ret != 0) 2252 return (ret); 2253 signotify(td); 2254 /* 2255 * Defer further processing for signals which are held, 2256 * except that stopped processes must be continued by SIGCONT. 2257 */ 2258 if (action == SIG_HOLD && 2259 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2260 return (ret); 2261 2262 wakeup_swapper = 0; 2263 2264 /* 2265 * Some signals have a process-wide effect and a per-thread 2266 * component. Most processing occurs when the process next 2267 * tries to cross the user boundary, however there are some 2268 * times when processing needs to be done immediately, such as 2269 * waking up threads so that they can cross the user boundary. 2270 * We try to do the per-process part here. 2271 */ 2272 if (P_SHOULDSTOP(p)) { 2273 KASSERT(!(p->p_flag & P_WEXIT), 2274 ("signal to stopped but exiting process")); 2275 if (sig == SIGKILL) { 2276 /* 2277 * If traced process is already stopped, 2278 * then no further action is necessary. 2279 */ 2280 if (p->p_flag & P_TRACED) 2281 goto out; 2282 /* 2283 * SIGKILL sets process running. 2284 * It will die elsewhere. 2285 * All threads must be restarted. 2286 */ 2287 p->p_flag &= ~P_STOPPED_SIG; 2288 goto runfast; 2289 } 2290 2291 if (prop & SIGPROP_CONT) { 2292 /* 2293 * If traced process is already stopped, 2294 * then no further action is necessary. 2295 */ 2296 if (p->p_flag & P_TRACED) 2297 goto out; 2298 /* 2299 * If SIGCONT is default (or ignored), we continue the 2300 * process but don't leave the signal in sigqueue as 2301 * it has no further action. If SIGCONT is held, we 2302 * continue the process and leave the signal in 2303 * sigqueue. If the process catches SIGCONT, let it 2304 * handle the signal itself. If it isn't waiting on 2305 * an event, it goes back to run state. 2306 * Otherwise, process goes back to sleep state. 2307 */ 2308 p->p_flag &= ~P_STOPPED_SIG; 2309 PROC_SLOCK(p); 2310 if (p->p_numthreads == p->p_suspcount) { 2311 PROC_SUNLOCK(p); 2312 p->p_flag |= P_CONTINUED; 2313 p->p_xsig = SIGCONT; 2314 PROC_LOCK(p->p_pptr); 2315 childproc_continued(p); 2316 PROC_UNLOCK(p->p_pptr); 2317 PROC_SLOCK(p); 2318 } 2319 if (action == SIG_DFL) { 2320 thread_unsuspend(p); 2321 PROC_SUNLOCK(p); 2322 sigqueue_delete(sigqueue, sig); 2323 goto out_cont; 2324 } 2325 if (action == SIG_CATCH) { 2326 /* 2327 * The process wants to catch it so it needs 2328 * to run at least one thread, but which one? 2329 */ 2330 PROC_SUNLOCK(p); 2331 goto runfast; 2332 } 2333 /* 2334 * The signal is not ignored or caught. 2335 */ 2336 thread_unsuspend(p); 2337 PROC_SUNLOCK(p); 2338 goto out_cont; 2339 } 2340 2341 if (prop & SIGPROP_STOP) { 2342 /* 2343 * If traced process is already stopped, 2344 * then no further action is necessary. 2345 */ 2346 if (p->p_flag & P_TRACED) 2347 goto out; 2348 /* 2349 * Already stopped, don't need to stop again 2350 * (If we did the shell could get confused). 2351 * Just make sure the signal STOP bit set. 2352 */ 2353 p->p_flag |= P_STOPPED_SIG; 2354 sigqueue_delete(sigqueue, sig); 2355 goto out; 2356 } 2357 2358 /* 2359 * All other kinds of signals: 2360 * If a thread is sleeping interruptibly, simulate a 2361 * wakeup so that when it is continued it will be made 2362 * runnable and can look at the signal. However, don't make 2363 * the PROCESS runnable, leave it stopped. 2364 * It may run a bit until it hits a thread_suspend_check(). 2365 */ 2366 PROC_SLOCK(p); 2367 thread_lock(td); 2368 if (TD_CAN_ABORT(td)) 2369 wakeup_swapper = sleepq_abort(td, intrval); 2370 else 2371 thread_unlock(td); 2372 PROC_SUNLOCK(p); 2373 goto out; 2374 /* 2375 * Mutexes are short lived. Threads waiting on them will 2376 * hit thread_suspend_check() soon. 2377 */ 2378 } else if (p->p_state == PRS_NORMAL) { 2379 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2380 tdsigwakeup(td, sig, action, intrval); 2381 goto out; 2382 } 2383 2384 MPASS(action == SIG_DFL); 2385 2386 if (prop & SIGPROP_STOP) { 2387 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2388 goto out; 2389 p->p_flag |= P_STOPPED_SIG; 2390 p->p_xsig = sig; 2391 PROC_SLOCK(p); 2392 wakeup_swapper = sig_suspend_threads(td, p, 1); 2393 if (p->p_numthreads == p->p_suspcount) { 2394 /* 2395 * only thread sending signal to another 2396 * process can reach here, if thread is sending 2397 * signal to its process, because thread does 2398 * not suspend itself here, p_numthreads 2399 * should never be equal to p_suspcount. 2400 */ 2401 thread_stopped(p); 2402 PROC_SUNLOCK(p); 2403 sigqueue_delete_proc(p, p->p_xsig); 2404 } else 2405 PROC_SUNLOCK(p); 2406 goto out; 2407 } 2408 } else { 2409 /* Not in "NORMAL" state. discard the signal. */ 2410 sigqueue_delete(sigqueue, sig); 2411 goto out; 2412 } 2413 2414 /* 2415 * The process is not stopped so we need to apply the signal to all the 2416 * running threads. 2417 */ 2418 runfast: 2419 tdsigwakeup(td, sig, action, intrval); 2420 PROC_SLOCK(p); 2421 thread_unsuspend(p); 2422 PROC_SUNLOCK(p); 2423 out_cont: 2424 itimer_proc_continue(p); 2425 kqtimer_proc_continue(p); 2426 out: 2427 /* If we jump here, proc slock should not be owned. */ 2428 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2429 if (wakeup_swapper) 2430 kick_proc0(); 2431 2432 return (ret); 2433 } 2434 2435 /* 2436 * The force of a signal has been directed against a single 2437 * thread. We need to see what we can do about knocking it 2438 * out of any sleep it may be in etc. 2439 */ 2440 static void 2441 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2442 { 2443 struct proc *p = td->td_proc; 2444 int prop, wakeup_swapper; 2445 2446 PROC_LOCK_ASSERT(p, MA_OWNED); 2447 prop = sigprop(sig); 2448 2449 PROC_SLOCK(p); 2450 thread_lock(td); 2451 /* 2452 * Bring the priority of a thread up if we want it to get 2453 * killed in this lifetime. Be careful to avoid bumping the 2454 * priority of the idle thread, since we still allow to signal 2455 * kernel processes. 2456 */ 2457 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2458 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2459 sched_prio(td, PUSER); 2460 if (TD_ON_SLEEPQ(td)) { 2461 /* 2462 * If thread is sleeping uninterruptibly 2463 * we can't interrupt the sleep... the signal will 2464 * be noticed when the process returns through 2465 * trap() or syscall(). 2466 */ 2467 if ((td->td_flags & TDF_SINTR) == 0) 2468 goto out; 2469 /* 2470 * If SIGCONT is default (or ignored) and process is 2471 * asleep, we are finished; the process should not 2472 * be awakened. 2473 */ 2474 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2475 thread_unlock(td); 2476 PROC_SUNLOCK(p); 2477 sigqueue_delete(&p->p_sigqueue, sig); 2478 /* 2479 * It may be on either list in this state. 2480 * Remove from both for now. 2481 */ 2482 sigqueue_delete(&td->td_sigqueue, sig); 2483 return; 2484 } 2485 2486 /* 2487 * Don't awaken a sleeping thread for SIGSTOP if the 2488 * STOP signal is deferred. 2489 */ 2490 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2491 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2492 goto out; 2493 2494 /* 2495 * Give low priority threads a better chance to run. 2496 */ 2497 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2498 sched_prio(td, PUSER); 2499 2500 wakeup_swapper = sleepq_abort(td, intrval); 2501 PROC_SUNLOCK(p); 2502 if (wakeup_swapper) 2503 kick_proc0(); 2504 return; 2505 } 2506 2507 /* 2508 * Other states do nothing with the signal immediately, 2509 * other than kicking ourselves if we are running. 2510 * It will either never be noticed, or noticed very soon. 2511 */ 2512 #ifdef SMP 2513 if (TD_IS_RUNNING(td) && td != curthread) 2514 forward_signal(td); 2515 #endif 2516 2517 out: 2518 PROC_SUNLOCK(p); 2519 thread_unlock(td); 2520 } 2521 2522 static void 2523 ptrace_coredump(struct thread *td) 2524 { 2525 struct proc *p; 2526 struct thr_coredump_req *tcq; 2527 void *rl_cookie; 2528 2529 MPASS(td == curthread); 2530 p = td->td_proc; 2531 PROC_LOCK_ASSERT(p, MA_OWNED); 2532 if ((td->td_dbgflags & TDB_COREDUMPRQ) == 0) 2533 return; 2534 KASSERT((p->p_flag & P_STOPPED_TRACE) != 0, ("not stopped")); 2535 2536 tcq = td->td_coredump; 2537 KASSERT(tcq != NULL, ("td_coredump is NULL")); 2538 2539 if (p->p_sysent->sv_coredump == NULL) { 2540 tcq->tc_error = ENOSYS; 2541 goto wake; 2542 } 2543 2544 PROC_UNLOCK(p); 2545 rl_cookie = vn_rangelock_wlock(tcq->tc_vp, 0, OFF_MAX); 2546 2547 tcq->tc_error = p->p_sysent->sv_coredump(td, tcq->tc_vp, 2548 tcq->tc_limit, tcq->tc_flags); 2549 2550 vn_rangelock_unlock(tcq->tc_vp, rl_cookie); 2551 PROC_LOCK(p); 2552 wake: 2553 td->td_dbgflags &= ~TDB_COREDUMPRQ; 2554 td->td_coredump = NULL; 2555 wakeup(p); 2556 } 2557 2558 static int 2559 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2560 { 2561 struct thread *td2; 2562 int wakeup_swapper; 2563 2564 PROC_LOCK_ASSERT(p, MA_OWNED); 2565 PROC_SLOCK_ASSERT(p, MA_OWNED); 2566 MPASS(sending || td == curthread); 2567 2568 wakeup_swapper = 0; 2569 FOREACH_THREAD_IN_PROC(p, td2) { 2570 thread_lock(td2); 2571 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2572 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2573 (td2->td_flags & TDF_SINTR)) { 2574 if (td2->td_flags & TDF_SBDRY) { 2575 /* 2576 * Once a thread is asleep with 2577 * TDF_SBDRY and without TDF_SERESTART 2578 * or TDF_SEINTR set, it should never 2579 * become suspended due to this check. 2580 */ 2581 KASSERT(!TD_IS_SUSPENDED(td2), 2582 ("thread with deferred stops suspended")); 2583 if (TD_SBDRY_INTR(td2)) { 2584 wakeup_swapper |= sleepq_abort(td2, 2585 TD_SBDRY_ERRNO(td2)); 2586 continue; 2587 } 2588 } else if (!TD_IS_SUSPENDED(td2)) 2589 thread_suspend_one(td2); 2590 } else if (!TD_IS_SUSPENDED(td2)) { 2591 if (sending || td != td2) 2592 td2->td_flags |= TDF_ASTPENDING; 2593 #ifdef SMP 2594 if (TD_IS_RUNNING(td2) && td2 != td) 2595 forward_signal(td2); 2596 #endif 2597 } 2598 thread_unlock(td2); 2599 } 2600 return (wakeup_swapper); 2601 } 2602 2603 /* 2604 * Stop the process for an event deemed interesting to the debugger. If si is 2605 * non-NULL, this is a signal exchange; the new signal requested by the 2606 * debugger will be returned for handling. If si is NULL, this is some other 2607 * type of interesting event. The debugger may request a signal be delivered in 2608 * that case as well, however it will be deferred until it can be handled. 2609 */ 2610 int 2611 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2612 { 2613 struct proc *p = td->td_proc; 2614 struct thread *td2; 2615 ksiginfo_t ksi; 2616 2617 PROC_LOCK_ASSERT(p, MA_OWNED); 2618 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2619 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2620 &p->p_mtx.lock_object, "Stopping for traced signal"); 2621 2622 td->td_xsig = sig; 2623 2624 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2625 td->td_dbgflags |= TDB_XSIG; 2626 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2627 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2628 PROC_SLOCK(p); 2629 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2630 if (P_KILLED(p)) { 2631 /* 2632 * Ensure that, if we've been PT_KILLed, the 2633 * exit status reflects that. Another thread 2634 * may also be in ptracestop(), having just 2635 * received the SIGKILL, but this thread was 2636 * unsuspended first. 2637 */ 2638 td->td_dbgflags &= ~TDB_XSIG; 2639 td->td_xsig = SIGKILL; 2640 p->p_ptevents = 0; 2641 break; 2642 } 2643 if (p->p_flag & P_SINGLE_EXIT && 2644 !(td->td_dbgflags & TDB_EXIT)) { 2645 /* 2646 * Ignore ptrace stops except for thread exit 2647 * events when the process exits. 2648 */ 2649 td->td_dbgflags &= ~TDB_XSIG; 2650 PROC_SUNLOCK(p); 2651 return (0); 2652 } 2653 2654 /* 2655 * Make wait(2) work. Ensure that right after the 2656 * attach, the thread which was decided to become the 2657 * leader of attach gets reported to the waiter. 2658 * Otherwise, just avoid overwriting another thread's 2659 * assignment to p_xthread. If another thread has 2660 * already set p_xthread, the current thread will get 2661 * a chance to report itself upon the next iteration. 2662 */ 2663 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2664 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2665 p->p_xthread == NULL)) { 2666 p->p_xsig = sig; 2667 p->p_xthread = td; 2668 2669 /* 2670 * If we are on sleepqueue already, 2671 * let sleepqueue code decide if it 2672 * needs to go sleep after attach. 2673 */ 2674 if (td->td_wchan == NULL) 2675 td->td_dbgflags &= ~TDB_FSTP; 2676 2677 p->p_flag2 &= ~P2_PTRACE_FSTP; 2678 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2679 sig_suspend_threads(td, p, 0); 2680 } 2681 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2682 td->td_dbgflags &= ~TDB_STOPATFORK; 2683 } 2684 stopme: 2685 td->td_dbgflags |= TDB_SSWITCH; 2686 thread_suspend_switch(td, p); 2687 td->td_dbgflags &= ~TDB_SSWITCH; 2688 if ((td->td_dbgflags & TDB_COREDUMPRQ) != 0) { 2689 PROC_SUNLOCK(p); 2690 ptrace_coredump(td); 2691 PROC_SLOCK(p); 2692 goto stopme; 2693 } 2694 if (p->p_xthread == td) 2695 p->p_xthread = NULL; 2696 if (!(p->p_flag & P_TRACED)) 2697 break; 2698 if (td->td_dbgflags & TDB_SUSPEND) { 2699 if (p->p_flag & P_SINGLE_EXIT) 2700 break; 2701 goto stopme; 2702 } 2703 } 2704 PROC_SUNLOCK(p); 2705 } 2706 2707 if (si != NULL && sig == td->td_xsig) { 2708 /* Parent wants us to take the original signal unchanged. */ 2709 si->ksi_flags |= KSI_HEAD; 2710 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2711 si->ksi_signo = 0; 2712 } else if (td->td_xsig != 0) { 2713 /* 2714 * If parent wants us to take a new signal, then it will leave 2715 * it in td->td_xsig; otherwise we just look for signals again. 2716 */ 2717 ksiginfo_init(&ksi); 2718 ksi.ksi_signo = td->td_xsig; 2719 ksi.ksi_flags |= KSI_PTRACE; 2720 td2 = sigtd(p, td->td_xsig, false); 2721 tdsendsignal(p, td2, td->td_xsig, &ksi); 2722 if (td != td2) 2723 return (0); 2724 } 2725 2726 return (td->td_xsig); 2727 } 2728 2729 static void 2730 reschedule_signals(struct proc *p, sigset_t block, int flags) 2731 { 2732 struct sigacts *ps; 2733 struct thread *td; 2734 int sig; 2735 bool fastblk, pslocked; 2736 2737 PROC_LOCK_ASSERT(p, MA_OWNED); 2738 ps = p->p_sigacts; 2739 pslocked = (flags & SIGPROCMASK_PS_LOCKED) != 0; 2740 mtx_assert(&ps->ps_mtx, pslocked ? MA_OWNED : MA_NOTOWNED); 2741 if (SIGISEMPTY(p->p_siglist)) 2742 return; 2743 SIGSETAND(block, p->p_siglist); 2744 fastblk = (flags & SIGPROCMASK_FASTBLK) != 0; 2745 while ((sig = sig_ffs(&block)) != 0) { 2746 SIGDELSET(block, sig); 2747 td = sigtd(p, sig, fastblk); 2748 2749 /* 2750 * If sigtd() selected us despite sigfastblock is 2751 * blocking, do not activate AST or wake us, to avoid 2752 * loop in AST handler. 2753 */ 2754 if (fastblk && td == curthread) 2755 continue; 2756 2757 signotify(td); 2758 if (!pslocked) 2759 mtx_lock(&ps->ps_mtx); 2760 if (p->p_flag & P_TRACED || 2761 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2762 !SIGISMEMBER(td->td_sigmask, sig))) { 2763 tdsigwakeup(td, sig, SIG_CATCH, 2764 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2765 ERESTART)); 2766 } 2767 if (!pslocked) 2768 mtx_unlock(&ps->ps_mtx); 2769 } 2770 } 2771 2772 void 2773 tdsigcleanup(struct thread *td) 2774 { 2775 struct proc *p; 2776 sigset_t unblocked; 2777 2778 p = td->td_proc; 2779 PROC_LOCK_ASSERT(p, MA_OWNED); 2780 2781 sigqueue_flush(&td->td_sigqueue); 2782 if (p->p_numthreads == 1) 2783 return; 2784 2785 /* 2786 * Since we cannot handle signals, notify signal post code 2787 * about this by filling the sigmask. 2788 * 2789 * Also, if needed, wake up thread(s) that do not block the 2790 * same signals as the exiting thread, since the thread might 2791 * have been selected for delivery and woken up. 2792 */ 2793 SIGFILLSET(unblocked); 2794 SIGSETNAND(unblocked, td->td_sigmask); 2795 SIGFILLSET(td->td_sigmask); 2796 reschedule_signals(p, unblocked, 0); 2797 2798 } 2799 2800 static int 2801 sigdeferstop_curr_flags(int cflags) 2802 { 2803 2804 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2805 (cflags & TDF_SBDRY) != 0); 2806 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2807 } 2808 2809 /* 2810 * Defer the delivery of SIGSTOP for the current thread, according to 2811 * the requested mode. Returns previous flags, which must be restored 2812 * by sigallowstop(). 2813 * 2814 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2815 * cleared by the current thread, which allow the lock-less read-only 2816 * accesses below. 2817 */ 2818 int 2819 sigdeferstop_impl(int mode) 2820 { 2821 struct thread *td; 2822 int cflags, nflags; 2823 2824 td = curthread; 2825 cflags = sigdeferstop_curr_flags(td->td_flags); 2826 switch (mode) { 2827 case SIGDEFERSTOP_NOP: 2828 nflags = cflags; 2829 break; 2830 case SIGDEFERSTOP_OFF: 2831 nflags = 0; 2832 break; 2833 case SIGDEFERSTOP_SILENT: 2834 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2835 break; 2836 case SIGDEFERSTOP_EINTR: 2837 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2838 break; 2839 case SIGDEFERSTOP_ERESTART: 2840 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2841 break; 2842 default: 2843 panic("sigdeferstop: invalid mode %x", mode); 2844 break; 2845 } 2846 if (cflags == nflags) 2847 return (SIGDEFERSTOP_VAL_NCHG); 2848 thread_lock(td); 2849 td->td_flags = (td->td_flags & ~cflags) | nflags; 2850 thread_unlock(td); 2851 return (cflags); 2852 } 2853 2854 /* 2855 * Restores the STOP handling mode, typically permitting the delivery 2856 * of SIGSTOP for the current thread. This does not immediately 2857 * suspend if a stop was posted. Instead, the thread will suspend 2858 * either via ast() or a subsequent interruptible sleep. 2859 */ 2860 void 2861 sigallowstop_impl(int prev) 2862 { 2863 struct thread *td; 2864 int cflags; 2865 2866 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2867 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2868 ("sigallowstop: incorrect previous mode %x", prev)); 2869 td = curthread; 2870 cflags = sigdeferstop_curr_flags(td->td_flags); 2871 if (cflags != prev) { 2872 thread_lock(td); 2873 td->td_flags = (td->td_flags & ~cflags) | prev; 2874 thread_unlock(td); 2875 } 2876 } 2877 2878 /* 2879 * If the current process has received a signal (should be caught or cause 2880 * termination, should interrupt current syscall), return the signal number. 2881 * Stop signals with default action are processed immediately, then cleared; 2882 * they aren't returned. This is checked after each entry to the system for 2883 * a syscall or trap (though this can usually be done without calling issignal 2884 * by checking the pending signal masks in cursig.) The normal call 2885 * sequence is 2886 * 2887 * while (sig = cursig(curthread)) 2888 * postsig(sig); 2889 */ 2890 static int 2891 issignal(struct thread *td) 2892 { 2893 struct proc *p; 2894 struct sigacts *ps; 2895 struct sigqueue *queue; 2896 sigset_t sigpending; 2897 ksiginfo_t ksi; 2898 int prop, sig; 2899 2900 p = td->td_proc; 2901 ps = p->p_sigacts; 2902 mtx_assert(&ps->ps_mtx, MA_OWNED); 2903 PROC_LOCK_ASSERT(p, MA_OWNED); 2904 for (;;) { 2905 sigpending = td->td_sigqueue.sq_signals; 2906 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2907 SIGSETNAND(sigpending, td->td_sigmask); 2908 2909 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2910 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2911 SIG_STOPSIGMASK(sigpending); 2912 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2913 return (0); 2914 2915 /* 2916 * Do fast sigblock if requested by usermode. Since 2917 * we do know that there was a signal pending at this 2918 * point, set the FAST_SIGBLOCK_PEND as indicator for 2919 * usermode to perform a dummy call to 2920 * FAST_SIGBLOCK_UNBLOCK, which causes immediate 2921 * delivery of postponed pending signal. 2922 */ 2923 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 2924 if (td->td_sigblock_val != 0) 2925 SIGSETNAND(sigpending, fastblock_mask); 2926 if (SIGISEMPTY(sigpending)) { 2927 td->td_pflags |= TDP_SIGFASTPENDING; 2928 return (0); 2929 } 2930 } 2931 2932 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2933 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2934 SIGISMEMBER(sigpending, SIGSTOP)) { 2935 /* 2936 * If debugger just attached, always consume 2937 * SIGSTOP from ptrace(PT_ATTACH) first, to 2938 * execute the debugger attach ritual in 2939 * order. 2940 */ 2941 sig = SIGSTOP; 2942 td->td_dbgflags |= TDB_FSTP; 2943 } else { 2944 sig = sig_ffs(&sigpending); 2945 } 2946 2947 /* 2948 * We should allow pending but ignored signals below 2949 * only if there is sigwait() active, or P_TRACED was 2950 * on when they were posted. 2951 */ 2952 if (SIGISMEMBER(ps->ps_sigignore, sig) && 2953 (p->p_flag & P_TRACED) == 0 && 2954 (td->td_pflags2 & TDP2_SIGWAIT) == 0) { 2955 sigqueue_delete(&td->td_sigqueue, sig); 2956 sigqueue_delete(&p->p_sigqueue, sig); 2957 continue; 2958 } 2959 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2960 /* 2961 * If traced, always stop. 2962 * Remove old signal from queue before the stop. 2963 * XXX shrug off debugger, it causes siginfo to 2964 * be thrown away. 2965 */ 2966 queue = &td->td_sigqueue; 2967 ksiginfo_init(&ksi); 2968 if (sigqueue_get(queue, sig, &ksi) == 0) { 2969 queue = &p->p_sigqueue; 2970 sigqueue_get(queue, sig, &ksi); 2971 } 2972 td->td_si = ksi.ksi_info; 2973 2974 mtx_unlock(&ps->ps_mtx); 2975 sig = ptracestop(td, sig, &ksi); 2976 mtx_lock(&ps->ps_mtx); 2977 2978 td->td_si.si_signo = 0; 2979 2980 /* 2981 * Keep looking if the debugger discarded or 2982 * replaced the signal. 2983 */ 2984 if (sig == 0) 2985 continue; 2986 2987 /* 2988 * If the signal became masked, re-queue it. 2989 */ 2990 if (SIGISMEMBER(td->td_sigmask, sig)) { 2991 ksi.ksi_flags |= KSI_HEAD; 2992 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2993 continue; 2994 } 2995 2996 /* 2997 * If the traced bit got turned off, requeue 2998 * the signal and go back up to the top to 2999 * rescan signals. This ensures that p_sig* 3000 * and p_sigact are consistent. 3001 */ 3002 if ((p->p_flag & P_TRACED) == 0) { 3003 ksi.ksi_flags |= KSI_HEAD; 3004 sigqueue_add(queue, sig, &ksi); 3005 continue; 3006 } 3007 } 3008 3009 prop = sigprop(sig); 3010 3011 /* 3012 * Decide whether the signal should be returned. 3013 * Return the signal's number, or fall through 3014 * to clear it from the pending mask. 3015 */ 3016 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 3017 case (intptr_t)SIG_DFL: 3018 /* 3019 * Don't take default actions on system processes. 3020 */ 3021 if (p->p_pid <= 1) { 3022 #ifdef DIAGNOSTIC 3023 /* 3024 * Are you sure you want to ignore SIGSEGV 3025 * in init? XXX 3026 */ 3027 printf("Process (pid %lu) got signal %d\n", 3028 (u_long)p->p_pid, sig); 3029 #endif 3030 break; /* == ignore */ 3031 } 3032 /* 3033 * If there is a pending stop signal to process with 3034 * default action, stop here, then clear the signal. 3035 * Traced or exiting processes should ignore stops. 3036 * Additionally, a member of an orphaned process group 3037 * should ignore tty stops. 3038 */ 3039 if (prop & SIGPROP_STOP) { 3040 mtx_unlock(&ps->ps_mtx); 3041 if ((p->p_flag & (P_TRACED | P_WEXIT | 3042 P_SINGLE_EXIT)) != 0 || ((p->p_pgrp-> 3043 pg_flags & PGRP_ORPHANED) != 0 && 3044 (prop & SIGPROP_TTYSTOP) != 0)) { 3045 mtx_lock(&ps->ps_mtx); 3046 break; /* == ignore */ 3047 } 3048 if (TD_SBDRY_INTR(td)) { 3049 KASSERT((td->td_flags & TDF_SBDRY) != 0, 3050 ("lost TDF_SBDRY")); 3051 mtx_lock(&ps->ps_mtx); 3052 return (-1); 3053 } 3054 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 3055 &p->p_mtx.lock_object, "Catching SIGSTOP"); 3056 sigqueue_delete(&td->td_sigqueue, sig); 3057 sigqueue_delete(&p->p_sigqueue, sig); 3058 p->p_flag |= P_STOPPED_SIG; 3059 p->p_xsig = sig; 3060 PROC_SLOCK(p); 3061 sig_suspend_threads(td, p, 0); 3062 thread_suspend_switch(td, p); 3063 PROC_SUNLOCK(p); 3064 mtx_lock(&ps->ps_mtx); 3065 goto next; 3066 } else if ((prop & SIGPROP_IGNORE) != 0 && 3067 (td->td_pflags2 & TDP2_SIGWAIT) == 0) { 3068 /* 3069 * Default action is to ignore; drop it if 3070 * not in kern_sigtimedwait(). 3071 */ 3072 break; /* == ignore */ 3073 } else 3074 return (sig); 3075 /*NOTREACHED*/ 3076 3077 case (intptr_t)SIG_IGN: 3078 if ((td->td_pflags2 & TDP2_SIGWAIT) == 0) 3079 break; /* == ignore */ 3080 else 3081 return (sig); 3082 3083 default: 3084 /* 3085 * This signal has an action, let 3086 * postsig() process it. 3087 */ 3088 return (sig); 3089 } 3090 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 3091 sigqueue_delete(&p->p_sigqueue, sig); 3092 next:; 3093 } 3094 /* NOTREACHED */ 3095 } 3096 3097 void 3098 thread_stopped(struct proc *p) 3099 { 3100 int n; 3101 3102 PROC_LOCK_ASSERT(p, MA_OWNED); 3103 PROC_SLOCK_ASSERT(p, MA_OWNED); 3104 n = p->p_suspcount; 3105 if (p == curproc) 3106 n++; 3107 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 3108 PROC_SUNLOCK(p); 3109 p->p_flag &= ~P_WAITED; 3110 PROC_LOCK(p->p_pptr); 3111 childproc_stopped(p, (p->p_flag & P_TRACED) ? 3112 CLD_TRAPPED : CLD_STOPPED); 3113 PROC_UNLOCK(p->p_pptr); 3114 PROC_SLOCK(p); 3115 } 3116 } 3117 3118 /* 3119 * Take the action for the specified signal 3120 * from the current set of pending signals. 3121 */ 3122 int 3123 postsig(int sig) 3124 { 3125 struct thread *td; 3126 struct proc *p; 3127 struct sigacts *ps; 3128 sig_t action; 3129 ksiginfo_t ksi; 3130 sigset_t returnmask; 3131 3132 KASSERT(sig != 0, ("postsig")); 3133 3134 td = curthread; 3135 p = td->td_proc; 3136 PROC_LOCK_ASSERT(p, MA_OWNED); 3137 ps = p->p_sigacts; 3138 mtx_assert(&ps->ps_mtx, MA_OWNED); 3139 ksiginfo_init(&ksi); 3140 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3141 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3142 return (0); 3143 ksi.ksi_signo = sig; 3144 if (ksi.ksi_code == SI_TIMER) 3145 itimer_accept(p, ksi.ksi_timerid, &ksi); 3146 action = ps->ps_sigact[_SIG_IDX(sig)]; 3147 #ifdef KTRACE 3148 if (KTRPOINT(td, KTR_PSIG)) 3149 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3150 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3151 #endif 3152 3153 if (action == SIG_DFL) { 3154 /* 3155 * Default action, where the default is to kill 3156 * the process. (Other cases were ignored above.) 3157 */ 3158 mtx_unlock(&ps->ps_mtx); 3159 proc_td_siginfo_capture(td, &ksi.ksi_info); 3160 sigexit(td, sig); 3161 /* NOTREACHED */ 3162 } else { 3163 /* 3164 * If we get here, the signal must be caught. 3165 */ 3166 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3167 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3168 ("postsig action: blocked sig %d", sig)); 3169 3170 /* 3171 * Set the new mask value and also defer further 3172 * occurrences of this signal. 3173 * 3174 * Special case: user has done a sigsuspend. Here the 3175 * current mask is not of interest, but rather the 3176 * mask from before the sigsuspend is what we want 3177 * restored after the signal processing is completed. 3178 */ 3179 if (td->td_pflags & TDP_OLDMASK) { 3180 returnmask = td->td_oldsigmask; 3181 td->td_pflags &= ~TDP_OLDMASK; 3182 } else 3183 returnmask = td->td_sigmask; 3184 3185 if (p->p_sig == sig) { 3186 p->p_sig = 0; 3187 } 3188 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3189 postsig_done(sig, td, ps); 3190 } 3191 return (1); 3192 } 3193 3194 int 3195 sig_ast_checksusp(struct thread *td) 3196 { 3197 struct proc *p; 3198 int ret; 3199 3200 p = td->td_proc; 3201 PROC_LOCK_ASSERT(p, MA_OWNED); 3202 3203 if ((td->td_flags & TDF_NEEDSUSPCHK) == 0) 3204 return (0); 3205 3206 ret = thread_suspend_check(1); 3207 MPASS(ret == 0 || ret == EINTR || ret == ERESTART); 3208 return (ret); 3209 } 3210 3211 int 3212 sig_ast_needsigchk(struct thread *td) 3213 { 3214 struct proc *p; 3215 struct sigacts *ps; 3216 int ret, sig; 3217 3218 p = td->td_proc; 3219 PROC_LOCK_ASSERT(p, MA_OWNED); 3220 3221 if ((td->td_flags & TDF_NEEDSIGCHK) == 0) 3222 return (0); 3223 3224 ps = p->p_sigacts; 3225 mtx_lock(&ps->ps_mtx); 3226 sig = cursig(td); 3227 if (sig == -1) { 3228 mtx_unlock(&ps->ps_mtx); 3229 KASSERT((td->td_flags & TDF_SBDRY) != 0, ("lost TDF_SBDRY")); 3230 KASSERT(TD_SBDRY_INTR(td), 3231 ("lost TDF_SERESTART of TDF_SEINTR")); 3232 KASSERT((td->td_flags & (TDF_SEINTR | TDF_SERESTART)) != 3233 (TDF_SEINTR | TDF_SERESTART), 3234 ("both TDF_SEINTR and TDF_SERESTART")); 3235 ret = TD_SBDRY_ERRNO(td); 3236 } else if (sig != 0) { 3237 ret = SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : ERESTART; 3238 mtx_unlock(&ps->ps_mtx); 3239 } else { 3240 mtx_unlock(&ps->ps_mtx); 3241 ret = 0; 3242 } 3243 3244 /* 3245 * Do not go into sleep if this thread was the ptrace(2) 3246 * attach leader. cursig() consumed SIGSTOP from PT_ATTACH, 3247 * but we usually act on the signal by interrupting sleep, and 3248 * should do that here as well. 3249 */ 3250 if ((td->td_dbgflags & TDB_FSTP) != 0) { 3251 if (ret == 0) 3252 ret = EINTR; 3253 td->td_dbgflags &= ~TDB_FSTP; 3254 } 3255 3256 return (ret); 3257 } 3258 3259 int 3260 sig_intr(void) 3261 { 3262 struct thread *td; 3263 struct proc *p; 3264 int ret; 3265 3266 td = curthread; 3267 if ((td->td_flags & (TDF_NEEDSIGCHK | TDF_NEEDSUSPCHK)) == 0) 3268 return (0); 3269 3270 p = td->td_proc; 3271 3272 PROC_LOCK(p); 3273 ret = sig_ast_checksusp(td); 3274 if (ret == 0) 3275 ret = sig_ast_needsigchk(td); 3276 PROC_UNLOCK(p); 3277 return (ret); 3278 } 3279 3280 void 3281 proc_wkilled(struct proc *p) 3282 { 3283 3284 PROC_LOCK_ASSERT(p, MA_OWNED); 3285 if ((p->p_flag & P_WKILLED) == 0) { 3286 p->p_flag |= P_WKILLED; 3287 /* 3288 * Notify swapper that there is a process to swap in. 3289 * The notification is racy, at worst it would take 10 3290 * seconds for the swapper process to notice. 3291 */ 3292 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3293 wakeup(&proc0); 3294 } 3295 } 3296 3297 /* 3298 * Kill the current process for stated reason. 3299 */ 3300 void 3301 killproc(struct proc *p, const char *why) 3302 { 3303 3304 PROC_LOCK_ASSERT(p, MA_OWNED); 3305 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3306 p->p_comm); 3307 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3308 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3309 p->p_ucred->cr_uid, why); 3310 proc_wkilled(p); 3311 kern_psignal(p, SIGKILL); 3312 } 3313 3314 /* 3315 * Force the current process to exit with the specified signal, dumping core 3316 * if appropriate. We bypass the normal tests for masked and caught signals, 3317 * allowing unrecoverable failures to terminate the process without changing 3318 * signal state. Mark the accounting record with the signal termination. 3319 * If dumping core, save the signal number for the debugger. Calls exit and 3320 * does not return. 3321 */ 3322 void 3323 sigexit(struct thread *td, int sig) 3324 { 3325 struct proc *p = td->td_proc; 3326 3327 PROC_LOCK_ASSERT(p, MA_OWNED); 3328 p->p_acflag |= AXSIG; 3329 /* 3330 * We must be single-threading to generate a core dump. This 3331 * ensures that the registers in the core file are up-to-date. 3332 * Also, the ELF dump handler assumes that the thread list doesn't 3333 * change out from under it. 3334 * 3335 * XXX If another thread attempts to single-thread before us 3336 * (e.g. via fork()), we won't get a dump at all. 3337 */ 3338 if ((sigprop(sig) & SIGPROP_CORE) && 3339 thread_single(p, SINGLE_NO_EXIT) == 0) { 3340 p->p_sig = sig; 3341 /* 3342 * Log signals which would cause core dumps 3343 * (Log as LOG_INFO to appease those who don't want 3344 * these messages.) 3345 * XXX : Todo, as well as euid, write out ruid too 3346 * Note that coredump() drops proc lock. 3347 */ 3348 if (coredump(td) == 0) 3349 sig |= WCOREFLAG; 3350 if (kern_logsigexit) 3351 log(LOG_INFO, 3352 "pid %d (%s), jid %d, uid %d: exited on " 3353 "signal %d%s\n", p->p_pid, p->p_comm, 3354 p->p_ucred->cr_prison->pr_id, 3355 td->td_ucred->cr_uid, 3356 sig &~ WCOREFLAG, 3357 sig & WCOREFLAG ? " (core dumped)" : ""); 3358 } else 3359 PROC_UNLOCK(p); 3360 exit1(td, 0, sig); 3361 /* NOTREACHED */ 3362 } 3363 3364 /* 3365 * Send queued SIGCHLD to parent when child process's state 3366 * is changed. 3367 */ 3368 static void 3369 sigparent(struct proc *p, int reason, int status) 3370 { 3371 PROC_LOCK_ASSERT(p, MA_OWNED); 3372 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3373 3374 if (p->p_ksi != NULL) { 3375 p->p_ksi->ksi_signo = SIGCHLD; 3376 p->p_ksi->ksi_code = reason; 3377 p->p_ksi->ksi_status = status; 3378 p->p_ksi->ksi_pid = p->p_pid; 3379 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3380 if (KSI_ONQ(p->p_ksi)) 3381 return; 3382 } 3383 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3384 } 3385 3386 static void 3387 childproc_jobstate(struct proc *p, int reason, int sig) 3388 { 3389 struct sigacts *ps; 3390 3391 PROC_LOCK_ASSERT(p, MA_OWNED); 3392 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3393 3394 /* 3395 * Wake up parent sleeping in kern_wait(), also send 3396 * SIGCHLD to parent, but SIGCHLD does not guarantee 3397 * that parent will awake, because parent may masked 3398 * the signal. 3399 */ 3400 p->p_pptr->p_flag |= P_STATCHILD; 3401 wakeup(p->p_pptr); 3402 3403 ps = p->p_pptr->p_sigacts; 3404 mtx_lock(&ps->ps_mtx); 3405 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3406 mtx_unlock(&ps->ps_mtx); 3407 sigparent(p, reason, sig); 3408 } else 3409 mtx_unlock(&ps->ps_mtx); 3410 } 3411 3412 void 3413 childproc_stopped(struct proc *p, int reason) 3414 { 3415 3416 childproc_jobstate(p, reason, p->p_xsig); 3417 } 3418 3419 void 3420 childproc_continued(struct proc *p) 3421 { 3422 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3423 } 3424 3425 void 3426 childproc_exited(struct proc *p) 3427 { 3428 int reason, status; 3429 3430 if (WCOREDUMP(p->p_xsig)) { 3431 reason = CLD_DUMPED; 3432 status = WTERMSIG(p->p_xsig); 3433 } else if (WIFSIGNALED(p->p_xsig)) { 3434 reason = CLD_KILLED; 3435 status = WTERMSIG(p->p_xsig); 3436 } else { 3437 reason = CLD_EXITED; 3438 status = p->p_xexit; 3439 } 3440 /* 3441 * XXX avoid calling wakeup(p->p_pptr), the work is 3442 * done in exit1(). 3443 */ 3444 sigparent(p, reason, status); 3445 } 3446 3447 #define MAX_NUM_CORE_FILES 100000 3448 #ifndef NUM_CORE_FILES 3449 #define NUM_CORE_FILES 5 3450 #endif 3451 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3452 static int num_cores = NUM_CORE_FILES; 3453 3454 static int 3455 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3456 { 3457 int error; 3458 int new_val; 3459 3460 new_val = num_cores; 3461 error = sysctl_handle_int(oidp, &new_val, 0, req); 3462 if (error != 0 || req->newptr == NULL) 3463 return (error); 3464 if (new_val > MAX_NUM_CORE_FILES) 3465 new_val = MAX_NUM_CORE_FILES; 3466 if (new_val < 0) 3467 new_val = 0; 3468 num_cores = new_val; 3469 return (0); 3470 } 3471 SYSCTL_PROC(_debug, OID_AUTO, ncores, 3472 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3473 sysctl_debug_num_cores_check, "I", 3474 "Maximum number of generated process corefiles while using index format"); 3475 3476 #define GZIP_SUFFIX ".gz" 3477 #define ZSTD_SUFFIX ".zst" 3478 3479 int compress_user_cores = 0; 3480 3481 static int 3482 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3483 { 3484 int error, val; 3485 3486 val = compress_user_cores; 3487 error = sysctl_handle_int(oidp, &val, 0, req); 3488 if (error != 0 || req->newptr == NULL) 3489 return (error); 3490 if (val != 0 && !compressor_avail(val)) 3491 return (EINVAL); 3492 compress_user_cores = val; 3493 return (error); 3494 } 3495 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, 3496 CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3497 sysctl_compress_user_cores, "I", 3498 "Enable compression of user corefiles (" 3499 __XSTRING(COMPRESS_GZIP) " = gzip, " 3500 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3501 3502 int compress_user_cores_level = 6; 3503 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3504 &compress_user_cores_level, 0, 3505 "Corefile compression level"); 3506 3507 /* 3508 * Protect the access to corefilename[] by allproc_lock. 3509 */ 3510 #define corefilename_lock allproc_lock 3511 3512 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3513 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3514 3515 static int 3516 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3517 { 3518 int error; 3519 3520 sx_xlock(&corefilename_lock); 3521 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3522 req); 3523 sx_xunlock(&corefilename_lock); 3524 3525 return (error); 3526 } 3527 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3528 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3529 "Process corefile name format string"); 3530 3531 static void 3532 vnode_close_locked(struct thread *td, struct vnode *vp) 3533 { 3534 3535 VOP_UNLOCK(vp); 3536 vn_close(vp, FWRITE, td->td_ucred, td); 3537 } 3538 3539 /* 3540 * If the core format has a %I in it, then we need to check 3541 * for existing corefiles before defining a name. 3542 * To do this we iterate over 0..ncores to find a 3543 * non-existing core file name to use. If all core files are 3544 * already used we choose the oldest one. 3545 */ 3546 static int 3547 corefile_open_last(struct thread *td, char *name, int indexpos, 3548 int indexlen, int ncores, struct vnode **vpp) 3549 { 3550 struct vnode *oldvp, *nextvp, *vp; 3551 struct vattr vattr; 3552 struct nameidata nd; 3553 int error, i, flags, oflags, cmode; 3554 char ch; 3555 struct timespec lasttime; 3556 3557 nextvp = oldvp = NULL; 3558 cmode = S_IRUSR | S_IWUSR; 3559 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3560 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3561 3562 for (i = 0; i < ncores; i++) { 3563 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3564 3565 ch = name[indexpos + indexlen]; 3566 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3567 i); 3568 name[indexpos + indexlen] = ch; 3569 3570 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3571 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3572 NULL); 3573 if (error != 0) 3574 break; 3575 3576 vp = nd.ni_vp; 3577 NDFREE(&nd, NDF_ONLY_PNBUF); 3578 if ((flags & O_CREAT) == O_CREAT) { 3579 nextvp = vp; 3580 break; 3581 } 3582 3583 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3584 if (error != 0) { 3585 vnode_close_locked(td, vp); 3586 break; 3587 } 3588 3589 if (oldvp == NULL || 3590 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3591 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3592 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3593 if (oldvp != NULL) 3594 vn_close(oldvp, FWRITE, td->td_ucred, td); 3595 oldvp = vp; 3596 VOP_UNLOCK(oldvp); 3597 lasttime = vattr.va_mtime; 3598 } else { 3599 vnode_close_locked(td, vp); 3600 } 3601 } 3602 3603 if (oldvp != NULL) { 3604 if (nextvp == NULL) { 3605 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3606 error = EFAULT; 3607 vn_close(oldvp, FWRITE, td->td_ucred, td); 3608 } else { 3609 nextvp = oldvp; 3610 error = vn_lock(nextvp, LK_EXCLUSIVE); 3611 if (error != 0) { 3612 vn_close(nextvp, FWRITE, td->td_ucred, 3613 td); 3614 nextvp = NULL; 3615 } 3616 } 3617 } else { 3618 vn_close(oldvp, FWRITE, td->td_ucred, td); 3619 } 3620 } 3621 if (error != 0) { 3622 if (nextvp != NULL) 3623 vnode_close_locked(td, oldvp); 3624 } else { 3625 *vpp = nextvp; 3626 } 3627 3628 return (error); 3629 } 3630 3631 /* 3632 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3633 * Expand the name described in corefilename, using name, uid, and pid 3634 * and open/create core file. 3635 * corefilename is a printf-like string, with three format specifiers: 3636 * %N name of process ("name") 3637 * %P process id (pid) 3638 * %U user id (uid) 3639 * For example, "%N.core" is the default; they can be disabled completely 3640 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3641 * This is controlled by the sysctl variable kern.corefile (see above). 3642 */ 3643 static int 3644 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3645 int compress, int signum, struct vnode **vpp, char **namep) 3646 { 3647 struct sbuf sb; 3648 struct nameidata nd; 3649 const char *format; 3650 char *hostname, *name; 3651 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3652 3653 hostname = NULL; 3654 format = corefilename; 3655 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3656 indexlen = 0; 3657 indexpos = -1; 3658 ncores = num_cores; 3659 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3660 sx_slock(&corefilename_lock); 3661 for (i = 0; format[i] != '\0'; i++) { 3662 switch (format[i]) { 3663 case '%': /* Format character */ 3664 i++; 3665 switch (format[i]) { 3666 case '%': 3667 sbuf_putc(&sb, '%'); 3668 break; 3669 case 'H': /* hostname */ 3670 if (hostname == NULL) { 3671 hostname = malloc(MAXHOSTNAMELEN, 3672 M_TEMP, M_WAITOK); 3673 } 3674 getcredhostname(td->td_ucred, hostname, 3675 MAXHOSTNAMELEN); 3676 sbuf_printf(&sb, "%s", hostname); 3677 break; 3678 case 'I': /* autoincrementing index */ 3679 if (indexpos != -1) { 3680 sbuf_printf(&sb, "%%I"); 3681 break; 3682 } 3683 3684 indexpos = sbuf_len(&sb); 3685 sbuf_printf(&sb, "%u", ncores - 1); 3686 indexlen = sbuf_len(&sb) - indexpos; 3687 break; 3688 case 'N': /* process name */ 3689 sbuf_printf(&sb, "%s", comm); 3690 break; 3691 case 'P': /* process id */ 3692 sbuf_printf(&sb, "%u", pid); 3693 break; 3694 case 'S': /* signal number */ 3695 sbuf_printf(&sb, "%i", signum); 3696 break; 3697 case 'U': /* user id */ 3698 sbuf_printf(&sb, "%u", uid); 3699 break; 3700 default: 3701 log(LOG_ERR, 3702 "Unknown format character %c in " 3703 "corename `%s'\n", format[i], format); 3704 break; 3705 } 3706 break; 3707 default: 3708 sbuf_putc(&sb, format[i]); 3709 break; 3710 } 3711 } 3712 sx_sunlock(&corefilename_lock); 3713 free(hostname, M_TEMP); 3714 if (compress == COMPRESS_GZIP) 3715 sbuf_printf(&sb, GZIP_SUFFIX); 3716 else if (compress == COMPRESS_ZSTD) 3717 sbuf_printf(&sb, ZSTD_SUFFIX); 3718 if (sbuf_error(&sb) != 0) { 3719 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3720 "long\n", (long)pid, comm, (u_long)uid); 3721 sbuf_delete(&sb); 3722 free(name, M_TEMP); 3723 return (ENOMEM); 3724 } 3725 sbuf_finish(&sb); 3726 sbuf_delete(&sb); 3727 3728 if (indexpos != -1) { 3729 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3730 vpp); 3731 if (error != 0) { 3732 log(LOG_ERR, 3733 "pid %d (%s), uid (%u): Path `%s' failed " 3734 "on initial open test, error = %d\n", 3735 pid, comm, uid, name, error); 3736 } 3737 } else { 3738 cmode = S_IRUSR | S_IWUSR; 3739 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3740 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3741 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3742 if ((td->td_proc->p_flag & P_SUGID) != 0) 3743 flags |= O_EXCL; 3744 3745 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3746 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3747 NULL); 3748 if (error == 0) { 3749 *vpp = nd.ni_vp; 3750 NDFREE(&nd, NDF_ONLY_PNBUF); 3751 } 3752 } 3753 3754 if (error != 0) { 3755 #ifdef AUDIT 3756 audit_proc_coredump(td, name, error); 3757 #endif 3758 free(name, M_TEMP); 3759 return (error); 3760 } 3761 *namep = name; 3762 return (0); 3763 } 3764 3765 /* 3766 * Dump a process' core. The main routine does some 3767 * policy checking, and creates the name of the coredump; 3768 * then it passes on a vnode and a size limit to the process-specific 3769 * coredump routine if there is one; if there _is not_ one, it returns 3770 * ENOSYS; otherwise it returns the error from the process-specific routine. 3771 */ 3772 3773 static int 3774 coredump(struct thread *td) 3775 { 3776 struct proc *p = td->td_proc; 3777 struct ucred *cred = td->td_ucred; 3778 struct vnode *vp; 3779 struct flock lf; 3780 struct vattr vattr; 3781 size_t fullpathsize; 3782 int error, error1, locked; 3783 char *name; /* name of corefile */ 3784 void *rl_cookie; 3785 off_t limit; 3786 char *fullpath, *freepath = NULL; 3787 struct sbuf *sb; 3788 3789 PROC_LOCK_ASSERT(p, MA_OWNED); 3790 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3791 3792 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3793 (p->p_flag2 & P2_NOTRACE) != 0) { 3794 PROC_UNLOCK(p); 3795 return (EFAULT); 3796 } 3797 3798 /* 3799 * Note that the bulk of limit checking is done after 3800 * the corefile is created. The exception is if the limit 3801 * for corefiles is 0, in which case we don't bother 3802 * creating the corefile at all. This layout means that 3803 * a corefile is truncated instead of not being created, 3804 * if it is larger than the limit. 3805 */ 3806 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3807 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3808 PROC_UNLOCK(p); 3809 return (EFBIG); 3810 } 3811 PROC_UNLOCK(p); 3812 3813 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3814 compress_user_cores, p->p_sig, &vp, &name); 3815 if (error != 0) 3816 return (error); 3817 3818 /* 3819 * Don't dump to non-regular files or files with links. 3820 * Do not dump into system files. Effective user must own the corefile. 3821 */ 3822 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3823 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 3824 vattr.va_uid != cred->cr_uid) { 3825 VOP_UNLOCK(vp); 3826 error = EFAULT; 3827 goto out; 3828 } 3829 3830 VOP_UNLOCK(vp); 3831 3832 /* Postpone other writers, including core dumps of other processes. */ 3833 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3834 3835 lf.l_whence = SEEK_SET; 3836 lf.l_start = 0; 3837 lf.l_len = 0; 3838 lf.l_type = F_WRLCK; 3839 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3840 3841 VATTR_NULL(&vattr); 3842 vattr.va_size = 0; 3843 if (set_core_nodump_flag) 3844 vattr.va_flags = UF_NODUMP; 3845 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3846 VOP_SETATTR(vp, &vattr, cred); 3847 VOP_UNLOCK(vp); 3848 PROC_LOCK(p); 3849 p->p_acflag |= ACORE; 3850 PROC_UNLOCK(p); 3851 3852 if (p->p_sysent->sv_coredump != NULL) { 3853 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3854 } else { 3855 error = ENOSYS; 3856 } 3857 3858 if (locked) { 3859 lf.l_type = F_UNLCK; 3860 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3861 } 3862 vn_rangelock_unlock(vp, rl_cookie); 3863 3864 /* 3865 * Notify the userland helper that a process triggered a core dump. 3866 * This allows the helper to run an automated debugging session. 3867 */ 3868 if (error != 0 || coredump_devctl == 0) 3869 goto out; 3870 sb = sbuf_new_auto(); 3871 if (vn_fullpath_global(p->p_textvp, &fullpath, &freepath) != 0) 3872 goto out2; 3873 sbuf_printf(sb, "comm=\""); 3874 devctl_safe_quote_sb(sb, fullpath); 3875 free(freepath, M_TEMP); 3876 sbuf_printf(sb, "\" core=\""); 3877 3878 /* 3879 * We can't lookup core file vp directly. When we're replacing a core, and 3880 * other random times, we flush the name cache, so it will fail. Instead, 3881 * if the path of the core is relative, add the current dir in front if it. 3882 */ 3883 if (name[0] != '/') { 3884 fullpathsize = MAXPATHLEN; 3885 freepath = malloc(fullpathsize, M_TEMP, M_WAITOK); 3886 if (vn_getcwd(freepath, &fullpath, &fullpathsize) != 0) { 3887 free(freepath, M_TEMP); 3888 goto out2; 3889 } 3890 devctl_safe_quote_sb(sb, fullpath); 3891 free(freepath, M_TEMP); 3892 sbuf_putc(sb, '/'); 3893 } 3894 devctl_safe_quote_sb(sb, name); 3895 sbuf_printf(sb, "\""); 3896 if (sbuf_finish(sb) == 0) 3897 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 3898 out2: 3899 sbuf_delete(sb); 3900 out: 3901 error1 = vn_close(vp, FWRITE, cred, td); 3902 if (error == 0) 3903 error = error1; 3904 #ifdef AUDIT 3905 audit_proc_coredump(td, name, error); 3906 #endif 3907 free(name, M_TEMP); 3908 return (error); 3909 } 3910 3911 /* 3912 * Nonexistent system call-- signal process (may want to handle it). Flag 3913 * error in case process won't see signal immediately (blocked or ignored). 3914 */ 3915 #ifndef _SYS_SYSPROTO_H_ 3916 struct nosys_args { 3917 int dummy; 3918 }; 3919 #endif 3920 /* ARGSUSED */ 3921 int 3922 nosys(struct thread *td, struct nosys_args *args) 3923 { 3924 struct proc *p; 3925 3926 p = td->td_proc; 3927 3928 PROC_LOCK(p); 3929 tdsignal(td, SIGSYS); 3930 PROC_UNLOCK(p); 3931 if (kern_lognosys == 1 || kern_lognosys == 3) { 3932 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3933 td->td_sa.code); 3934 } 3935 if (kern_lognosys == 2 || kern_lognosys == 3 || 3936 (p->p_pid == 1 && (kern_lognosys & 3) == 0)) { 3937 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3938 td->td_sa.code); 3939 } 3940 return (ENOSYS); 3941 } 3942 3943 /* 3944 * Send a SIGIO or SIGURG signal to a process or process group using stored 3945 * credentials rather than those of the current process. 3946 */ 3947 void 3948 pgsigio(struct sigio **sigiop, int sig, int checkctty) 3949 { 3950 ksiginfo_t ksi; 3951 struct sigio *sigio; 3952 3953 ksiginfo_init(&ksi); 3954 ksi.ksi_signo = sig; 3955 ksi.ksi_code = SI_KERNEL; 3956 3957 SIGIO_LOCK(); 3958 sigio = *sigiop; 3959 if (sigio == NULL) { 3960 SIGIO_UNLOCK(); 3961 return; 3962 } 3963 if (sigio->sio_pgid > 0) { 3964 PROC_LOCK(sigio->sio_proc); 3965 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3966 kern_psignal(sigio->sio_proc, sig); 3967 PROC_UNLOCK(sigio->sio_proc); 3968 } else if (sigio->sio_pgid < 0) { 3969 struct proc *p; 3970 3971 PGRP_LOCK(sigio->sio_pgrp); 3972 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3973 PROC_LOCK(p); 3974 if (p->p_state == PRS_NORMAL && 3975 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3976 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3977 kern_psignal(p, sig); 3978 PROC_UNLOCK(p); 3979 } 3980 PGRP_UNLOCK(sigio->sio_pgrp); 3981 } 3982 SIGIO_UNLOCK(); 3983 } 3984 3985 static int 3986 filt_sigattach(struct knote *kn) 3987 { 3988 struct proc *p = curproc; 3989 3990 kn->kn_ptr.p_proc = p; 3991 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3992 3993 knlist_add(p->p_klist, kn, 0); 3994 3995 return (0); 3996 } 3997 3998 static void 3999 filt_sigdetach(struct knote *kn) 4000 { 4001 struct proc *p = kn->kn_ptr.p_proc; 4002 4003 knlist_remove(p->p_klist, kn, 0); 4004 } 4005 4006 /* 4007 * signal knotes are shared with proc knotes, so we apply a mask to 4008 * the hint in order to differentiate them from process hints. This 4009 * could be avoided by using a signal-specific knote list, but probably 4010 * isn't worth the trouble. 4011 */ 4012 static int 4013 filt_signal(struct knote *kn, long hint) 4014 { 4015 4016 if (hint & NOTE_SIGNAL) { 4017 hint &= ~NOTE_SIGNAL; 4018 4019 if (kn->kn_id == hint) 4020 kn->kn_data++; 4021 } 4022 return (kn->kn_data != 0); 4023 } 4024 4025 struct sigacts * 4026 sigacts_alloc(void) 4027 { 4028 struct sigacts *ps; 4029 4030 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 4031 refcount_init(&ps->ps_refcnt, 1); 4032 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 4033 return (ps); 4034 } 4035 4036 void 4037 sigacts_free(struct sigacts *ps) 4038 { 4039 4040 if (refcount_release(&ps->ps_refcnt) == 0) 4041 return; 4042 mtx_destroy(&ps->ps_mtx); 4043 free(ps, M_SUBPROC); 4044 } 4045 4046 struct sigacts * 4047 sigacts_hold(struct sigacts *ps) 4048 { 4049 4050 refcount_acquire(&ps->ps_refcnt); 4051 return (ps); 4052 } 4053 4054 void 4055 sigacts_copy(struct sigacts *dest, struct sigacts *src) 4056 { 4057 4058 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 4059 mtx_lock(&src->ps_mtx); 4060 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 4061 mtx_unlock(&src->ps_mtx); 4062 } 4063 4064 int 4065 sigacts_shared(struct sigacts *ps) 4066 { 4067 4068 return (ps->ps_refcnt > 1); 4069 } 4070 4071 void 4072 sig_drop_caught(struct proc *p) 4073 { 4074 int sig; 4075 struct sigacts *ps; 4076 4077 ps = p->p_sigacts; 4078 PROC_LOCK_ASSERT(p, MA_OWNED); 4079 mtx_assert(&ps->ps_mtx, MA_OWNED); 4080 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 4081 sig = sig_ffs(&ps->ps_sigcatch); 4082 sigdflt(ps, sig); 4083 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 4084 sigqueue_delete_proc(p, sig); 4085 } 4086 } 4087 4088 static void 4089 sigfastblock_failed(struct thread *td, bool sendsig, bool write) 4090 { 4091 ksiginfo_t ksi; 4092 4093 /* 4094 * Prevent further fetches and SIGSEGVs, allowing thread to 4095 * issue syscalls despite corruption. 4096 */ 4097 sigfastblock_clear(td); 4098 4099 if (!sendsig) 4100 return; 4101 ksiginfo_init_trap(&ksi); 4102 ksi.ksi_signo = SIGSEGV; 4103 ksi.ksi_code = write ? SEGV_ACCERR : SEGV_MAPERR; 4104 ksi.ksi_addr = td->td_sigblock_ptr; 4105 trapsignal(td, &ksi); 4106 } 4107 4108 static bool 4109 sigfastblock_fetch_sig(struct thread *td, bool sendsig, uint32_t *valp) 4110 { 4111 uint32_t res; 4112 4113 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4114 return (true); 4115 if (fueword32((void *)td->td_sigblock_ptr, &res) == -1) { 4116 sigfastblock_failed(td, sendsig, false); 4117 return (false); 4118 } 4119 *valp = res; 4120 td->td_sigblock_val = res & ~SIGFASTBLOCK_FLAGS; 4121 return (true); 4122 } 4123 4124 static void 4125 sigfastblock_resched(struct thread *td, bool resched) 4126 { 4127 struct proc *p; 4128 4129 if (resched) { 4130 p = td->td_proc; 4131 PROC_LOCK(p); 4132 reschedule_signals(p, td->td_sigmask, 0); 4133 PROC_UNLOCK(p); 4134 } 4135 thread_lock(td); 4136 td->td_flags |= TDF_ASTPENDING | TDF_NEEDSIGCHK; 4137 thread_unlock(td); 4138 } 4139 4140 int 4141 sys_sigfastblock(struct thread *td, struct sigfastblock_args *uap) 4142 { 4143 struct proc *p; 4144 int error, res; 4145 uint32_t oldval; 4146 4147 error = 0; 4148 p = td->td_proc; 4149 switch (uap->cmd) { 4150 case SIGFASTBLOCK_SETPTR: 4151 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 4152 error = EBUSY; 4153 break; 4154 } 4155 if (((uintptr_t)(uap->ptr) & (sizeof(uint32_t) - 1)) != 0) { 4156 error = EINVAL; 4157 break; 4158 } 4159 td->td_pflags |= TDP_SIGFASTBLOCK; 4160 td->td_sigblock_ptr = uap->ptr; 4161 break; 4162 4163 case SIGFASTBLOCK_UNBLOCK: 4164 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4165 error = EINVAL; 4166 break; 4167 } 4168 4169 for (;;) { 4170 res = casueword32(td->td_sigblock_ptr, 4171 SIGFASTBLOCK_PEND, &oldval, 0); 4172 if (res == -1) { 4173 error = EFAULT; 4174 sigfastblock_failed(td, false, true); 4175 break; 4176 } 4177 if (res == 0) 4178 break; 4179 MPASS(res == 1); 4180 if (oldval != SIGFASTBLOCK_PEND) { 4181 error = EBUSY; 4182 break; 4183 } 4184 error = thread_check_susp(td, false); 4185 if (error != 0) 4186 break; 4187 } 4188 if (error != 0) 4189 break; 4190 4191 /* 4192 * td_sigblock_val is cleared there, but not on a 4193 * syscall exit. The end effect is that a single 4194 * interruptible sleep, while user sigblock word is 4195 * set, might return EINTR or ERESTART to usermode 4196 * without delivering signal. All further sleeps, 4197 * until userspace clears the word and does 4198 * sigfastblock(UNBLOCK), observe current word and no 4199 * longer get interrupted. It is slight 4200 * non-conformance, with alternative to have read the 4201 * sigblock word on each syscall entry. 4202 */ 4203 td->td_sigblock_val = 0; 4204 4205 /* 4206 * Rely on normal ast mechanism to deliver pending 4207 * signals to current thread. But notify others about 4208 * fake unblock. 4209 */ 4210 sigfastblock_resched(td, error == 0 && p->p_numthreads != 1); 4211 4212 break; 4213 4214 case SIGFASTBLOCK_UNSETPTR: 4215 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4216 error = EINVAL; 4217 break; 4218 } 4219 if (!sigfastblock_fetch_sig(td, false, &oldval)) { 4220 error = EFAULT; 4221 break; 4222 } 4223 if (oldval != 0 && oldval != SIGFASTBLOCK_PEND) { 4224 error = EBUSY; 4225 break; 4226 } 4227 sigfastblock_clear(td); 4228 break; 4229 4230 default: 4231 error = EINVAL; 4232 break; 4233 } 4234 return (error); 4235 } 4236 4237 void 4238 sigfastblock_clear(struct thread *td) 4239 { 4240 bool resched; 4241 4242 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4243 return; 4244 td->td_sigblock_val = 0; 4245 resched = (td->td_pflags & TDP_SIGFASTPENDING) != 0 || 4246 SIGPENDING(td); 4247 td->td_pflags &= ~(TDP_SIGFASTBLOCK | TDP_SIGFASTPENDING); 4248 sigfastblock_resched(td, resched); 4249 } 4250 4251 void 4252 sigfastblock_fetch(struct thread *td) 4253 { 4254 uint32_t val; 4255 4256 (void)sigfastblock_fetch_sig(td, true, &val); 4257 } 4258 4259 static void 4260 sigfastblock_setpend1(struct thread *td) 4261 { 4262 int res; 4263 uint32_t oldval; 4264 4265 if ((td->td_pflags & TDP_SIGFASTPENDING) == 0) 4266 return; 4267 res = fueword32((void *)td->td_sigblock_ptr, &oldval); 4268 if (res == -1) { 4269 sigfastblock_failed(td, true, false); 4270 return; 4271 } 4272 for (;;) { 4273 res = casueword32(td->td_sigblock_ptr, oldval, &oldval, 4274 oldval | SIGFASTBLOCK_PEND); 4275 if (res == -1) { 4276 sigfastblock_failed(td, true, true); 4277 return; 4278 } 4279 if (res == 0) { 4280 td->td_sigblock_val = oldval & ~SIGFASTBLOCK_FLAGS; 4281 td->td_pflags &= ~TDP_SIGFASTPENDING; 4282 break; 4283 } 4284 MPASS(res == 1); 4285 if (thread_check_susp(td, false) != 0) 4286 break; 4287 } 4288 } 4289 4290 void 4291 sigfastblock_setpend(struct thread *td, bool resched) 4292 { 4293 struct proc *p; 4294 4295 sigfastblock_setpend1(td); 4296 if (resched) { 4297 p = td->td_proc; 4298 PROC_LOCK(p); 4299 reschedule_signals(p, fastblock_mask, SIGPROCMASK_FASTBLK); 4300 PROC_UNLOCK(p); 4301 } 4302 } 4303