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 thread_lock(td); 1283 td->td_flags |= TDF_SIGWAIT; 1284 thread_unlock(td); 1285 } 1286 for (;;) { 1287 mtx_lock(&ps->ps_mtx); 1288 sig = cursig(td); 1289 mtx_unlock(&ps->ps_mtx); 1290 KASSERT(sig >= 0, ("sig %d", sig)); 1291 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1292 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1293 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1294 error = 0; 1295 break; 1296 } 1297 } 1298 1299 if (error != 0) 1300 break; 1301 1302 /* 1303 * POSIX says this must be checked after looking for pending 1304 * signals. 1305 */ 1306 if (timeout != NULL) { 1307 if (!timevalid) { 1308 error = EINVAL; 1309 break; 1310 } 1311 getnanouptime(&rts); 1312 if (timespeccmp(&rts, &ets, >=)) { 1313 error = EAGAIN; 1314 break; 1315 } 1316 timespecsub(&ets, &rts, &ts); 1317 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1318 timo = tvtohz(&tv); 1319 } else { 1320 timo = 0; 1321 } 1322 1323 if (traced) { 1324 error = EINTR; 1325 break; 1326 } 1327 1328 error = msleep(&p->p_sigacts, &p->p_mtx, PPAUSE | PCATCH, 1329 "sigwait", timo); 1330 1331 /* The syscalls can not be restarted. */ 1332 if (error == ERESTART) 1333 error = EINTR; 1334 1335 /* We will calculate timeout by ourself. */ 1336 if (timeout != NULL && error == EAGAIN) 1337 error = 0; 1338 1339 /* 1340 * If PTRACE_SCE or PTRACE_SCX were set after 1341 * userspace entered the syscall, return spurious 1342 * EINTR after wait was done. Only do this as last 1343 * resort after rechecking for possible queued signals 1344 * and expired timeouts. 1345 */ 1346 if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0) 1347 traced = true; 1348 } 1349 thread_lock(td); 1350 td->td_flags &= ~TDF_SIGWAIT; 1351 thread_unlock(td); 1352 1353 new_block = saved_mask; 1354 SIGSETNAND(new_block, td->td_sigmask); 1355 td->td_sigmask = saved_mask; 1356 /* 1357 * Fewer signals can be delivered to us, reschedule signal 1358 * notification. 1359 */ 1360 if (p->p_numthreads != 1) 1361 reschedule_signals(p, new_block, 0); 1362 1363 if (error == 0) { 1364 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1365 1366 if (ksi->ksi_code == SI_TIMER) 1367 itimer_accept(p, ksi->ksi_timerid, ksi); 1368 1369 #ifdef KTRACE 1370 if (KTRPOINT(td, KTR_PSIG)) { 1371 sig_t action; 1372 1373 mtx_lock(&ps->ps_mtx); 1374 action = ps->ps_sigact[_SIG_IDX(sig)]; 1375 mtx_unlock(&ps->ps_mtx); 1376 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1377 } 1378 #endif 1379 if (sig == SIGKILL) { 1380 proc_td_siginfo_capture(td, &ksi->ksi_info); 1381 sigexit(td, sig); 1382 } 1383 } 1384 PROC_UNLOCK(p); 1385 return (error); 1386 } 1387 1388 #ifndef _SYS_SYSPROTO_H_ 1389 struct sigpending_args { 1390 sigset_t *set; 1391 }; 1392 #endif 1393 int 1394 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1395 { 1396 struct proc *p = td->td_proc; 1397 sigset_t pending; 1398 1399 PROC_LOCK(p); 1400 pending = p->p_sigqueue.sq_signals; 1401 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1402 PROC_UNLOCK(p); 1403 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1404 } 1405 1406 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1407 #ifndef _SYS_SYSPROTO_H_ 1408 struct osigpending_args { 1409 int dummy; 1410 }; 1411 #endif 1412 int 1413 osigpending(struct thread *td, struct osigpending_args *uap) 1414 { 1415 struct proc *p = td->td_proc; 1416 sigset_t pending; 1417 1418 PROC_LOCK(p); 1419 pending = p->p_sigqueue.sq_signals; 1420 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1421 PROC_UNLOCK(p); 1422 SIG2OSIG(pending, td->td_retval[0]); 1423 return (0); 1424 } 1425 #endif /* COMPAT_43 */ 1426 1427 #if defined(COMPAT_43) 1428 /* 1429 * Generalized interface signal handler, 4.3-compatible. 1430 */ 1431 #ifndef _SYS_SYSPROTO_H_ 1432 struct osigvec_args { 1433 int signum; 1434 struct sigvec *nsv; 1435 struct sigvec *osv; 1436 }; 1437 #endif 1438 /* ARGSUSED */ 1439 int 1440 osigvec(struct thread *td, struct osigvec_args *uap) 1441 { 1442 struct sigvec vec; 1443 struct sigaction nsa, osa; 1444 struct sigaction *nsap, *osap; 1445 int error; 1446 1447 if (uap->signum <= 0 || uap->signum >= ONSIG) 1448 return (EINVAL); 1449 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1450 osap = (uap->osv != NULL) ? &osa : NULL; 1451 if (nsap) { 1452 error = copyin(uap->nsv, &vec, sizeof(vec)); 1453 if (error) 1454 return (error); 1455 nsap->sa_handler = vec.sv_handler; 1456 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1457 nsap->sa_flags = vec.sv_flags; 1458 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1459 } 1460 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1461 if (osap && !error) { 1462 vec.sv_handler = osap->sa_handler; 1463 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1464 vec.sv_flags = osap->sa_flags; 1465 vec.sv_flags &= ~SA_NOCLDWAIT; 1466 vec.sv_flags ^= SA_RESTART; 1467 error = copyout(&vec, uap->osv, sizeof(vec)); 1468 } 1469 return (error); 1470 } 1471 1472 #ifndef _SYS_SYSPROTO_H_ 1473 struct osigblock_args { 1474 int mask; 1475 }; 1476 #endif 1477 int 1478 osigblock(struct thread *td, struct osigblock_args *uap) 1479 { 1480 sigset_t set, oset; 1481 1482 OSIG2SIG(uap->mask, set); 1483 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1484 SIG2OSIG(oset, td->td_retval[0]); 1485 return (0); 1486 } 1487 1488 #ifndef _SYS_SYSPROTO_H_ 1489 struct osigsetmask_args { 1490 int mask; 1491 }; 1492 #endif 1493 int 1494 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1495 { 1496 sigset_t set, oset; 1497 1498 OSIG2SIG(uap->mask, set); 1499 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1500 SIG2OSIG(oset, td->td_retval[0]); 1501 return (0); 1502 } 1503 #endif /* COMPAT_43 */ 1504 1505 /* 1506 * Suspend calling thread until signal, providing mask to be set in the 1507 * meantime. 1508 */ 1509 #ifndef _SYS_SYSPROTO_H_ 1510 struct sigsuspend_args { 1511 const sigset_t *sigmask; 1512 }; 1513 #endif 1514 /* ARGSUSED */ 1515 int 1516 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1517 { 1518 sigset_t mask; 1519 int error; 1520 1521 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1522 if (error) 1523 return (error); 1524 return (kern_sigsuspend(td, mask)); 1525 } 1526 1527 int 1528 kern_sigsuspend(struct thread *td, sigset_t mask) 1529 { 1530 struct proc *p = td->td_proc; 1531 int has_sig, sig; 1532 1533 /* Ensure the sigfastblock value is up to date. */ 1534 sigfastblock_fetch(td); 1535 1536 /* 1537 * When returning from sigsuspend, we want 1538 * the old mask to be restored after the 1539 * signal handler has finished. Thus, we 1540 * save it here and mark the sigacts structure 1541 * to indicate this. 1542 */ 1543 PROC_LOCK(p); 1544 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1545 SIGPROCMASK_PROC_LOCKED); 1546 td->td_pflags |= TDP_OLDMASK; 1547 1548 /* 1549 * Process signals now. Otherwise, we can get spurious wakeup 1550 * due to signal entered process queue, but delivered to other 1551 * thread. But sigsuspend should return only on signal 1552 * delivery. 1553 */ 1554 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1555 for (has_sig = 0; !has_sig;) { 1556 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1557 0) == 0) 1558 /* void */; 1559 thread_suspend_check(0); 1560 mtx_lock(&p->p_sigacts->ps_mtx); 1561 while ((sig = cursig(td)) != 0) { 1562 KASSERT(sig >= 0, ("sig %d", sig)); 1563 has_sig += postsig(sig); 1564 } 1565 mtx_unlock(&p->p_sigacts->ps_mtx); 1566 1567 /* 1568 * If PTRACE_SCE or PTRACE_SCX were set after 1569 * userspace entered the syscall, return spurious 1570 * EINTR. 1571 */ 1572 if ((p->p_ptevents & PTRACE_SYSCALL) != 0) 1573 has_sig += 1; 1574 } 1575 PROC_UNLOCK(p); 1576 td->td_errno = EINTR; 1577 td->td_pflags |= TDP_NERRNO; 1578 return (EJUSTRETURN); 1579 } 1580 1581 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1582 /* 1583 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1584 * convention: libc stub passes mask, not pointer, to save a copyin. 1585 */ 1586 #ifndef _SYS_SYSPROTO_H_ 1587 struct osigsuspend_args { 1588 osigset_t mask; 1589 }; 1590 #endif 1591 /* ARGSUSED */ 1592 int 1593 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1594 { 1595 sigset_t mask; 1596 1597 OSIG2SIG(uap->mask, mask); 1598 return (kern_sigsuspend(td, mask)); 1599 } 1600 #endif /* COMPAT_43 */ 1601 1602 #if defined(COMPAT_43) 1603 #ifndef _SYS_SYSPROTO_H_ 1604 struct osigstack_args { 1605 struct sigstack *nss; 1606 struct sigstack *oss; 1607 }; 1608 #endif 1609 /* ARGSUSED */ 1610 int 1611 osigstack(struct thread *td, struct osigstack_args *uap) 1612 { 1613 struct sigstack nss, oss; 1614 int error = 0; 1615 1616 if (uap->nss != NULL) { 1617 error = copyin(uap->nss, &nss, sizeof(nss)); 1618 if (error) 1619 return (error); 1620 } 1621 oss.ss_sp = td->td_sigstk.ss_sp; 1622 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1623 if (uap->nss != NULL) { 1624 td->td_sigstk.ss_sp = nss.ss_sp; 1625 td->td_sigstk.ss_size = 0; 1626 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1627 td->td_pflags |= TDP_ALTSTACK; 1628 } 1629 if (uap->oss != NULL) 1630 error = copyout(&oss, uap->oss, sizeof(oss)); 1631 1632 return (error); 1633 } 1634 #endif /* COMPAT_43 */ 1635 1636 #ifndef _SYS_SYSPROTO_H_ 1637 struct sigaltstack_args { 1638 stack_t *ss; 1639 stack_t *oss; 1640 }; 1641 #endif 1642 /* ARGSUSED */ 1643 int 1644 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1645 { 1646 stack_t ss, oss; 1647 int error; 1648 1649 if (uap->ss != NULL) { 1650 error = copyin(uap->ss, &ss, sizeof(ss)); 1651 if (error) 1652 return (error); 1653 } 1654 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1655 (uap->oss != NULL) ? &oss : NULL); 1656 if (error) 1657 return (error); 1658 if (uap->oss != NULL) 1659 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1660 return (error); 1661 } 1662 1663 int 1664 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1665 { 1666 struct proc *p = td->td_proc; 1667 int oonstack; 1668 1669 oonstack = sigonstack(cpu_getstack(td)); 1670 1671 if (oss != NULL) { 1672 *oss = td->td_sigstk; 1673 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1674 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1675 } 1676 1677 if (ss != NULL) { 1678 if (oonstack) 1679 return (EPERM); 1680 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1681 return (EINVAL); 1682 if (!(ss->ss_flags & SS_DISABLE)) { 1683 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1684 return (ENOMEM); 1685 1686 td->td_sigstk = *ss; 1687 td->td_pflags |= TDP_ALTSTACK; 1688 } else { 1689 td->td_pflags &= ~TDP_ALTSTACK; 1690 } 1691 } 1692 return (0); 1693 } 1694 1695 struct killpg1_ctx { 1696 struct thread *td; 1697 ksiginfo_t *ksi; 1698 int sig; 1699 bool sent; 1700 bool found; 1701 int ret; 1702 }; 1703 1704 static void 1705 killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg) 1706 { 1707 int err; 1708 1709 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 || 1710 (notself && p == arg->td->td_proc) || p->p_state == PRS_NEW) 1711 return; 1712 PROC_LOCK(p); 1713 err = p_cansignal(arg->td, p, arg->sig); 1714 if (err == 0 && arg->sig != 0) 1715 pksignal(p, arg->sig, arg->ksi); 1716 PROC_UNLOCK(p); 1717 if (err != ESRCH) 1718 arg->found = true; 1719 if (err == 0) 1720 arg->sent = true; 1721 else if (arg->ret == 0 && err != ESRCH && err != EPERM) 1722 arg->ret = err; 1723 } 1724 1725 /* 1726 * Common code for kill process group/broadcast kill. 1727 * cp is calling process. 1728 */ 1729 static int 1730 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1731 { 1732 struct proc *p; 1733 struct pgrp *pgrp; 1734 struct killpg1_ctx arg; 1735 1736 arg.td = td; 1737 arg.ksi = ksi; 1738 arg.sig = sig; 1739 arg.sent = false; 1740 arg.found = false; 1741 arg.ret = 0; 1742 if (all) { 1743 /* 1744 * broadcast 1745 */ 1746 sx_slock(&allproc_lock); 1747 FOREACH_PROC_IN_SYSTEM(p) { 1748 killpg1_sendsig(p, true, &arg); 1749 } 1750 sx_sunlock(&allproc_lock); 1751 } else { 1752 sx_slock(&proctree_lock); 1753 if (pgid == 0) { 1754 /* 1755 * zero pgid means send to my process group. 1756 */ 1757 pgrp = td->td_proc->p_pgrp; 1758 PGRP_LOCK(pgrp); 1759 } else { 1760 pgrp = pgfind(pgid); 1761 if (pgrp == NULL) { 1762 sx_sunlock(&proctree_lock); 1763 return (ESRCH); 1764 } 1765 } 1766 sx_sunlock(&proctree_lock); 1767 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1768 killpg1_sendsig(p, false, &arg); 1769 } 1770 PGRP_UNLOCK(pgrp); 1771 } 1772 MPASS(arg.ret != 0 || arg.found || !arg.sent); 1773 if (arg.ret == 0 && !arg.sent) 1774 arg.ret = arg.found ? EPERM : ESRCH; 1775 return (arg.ret); 1776 } 1777 1778 #ifndef _SYS_SYSPROTO_H_ 1779 struct kill_args { 1780 int pid; 1781 int signum; 1782 }; 1783 #endif 1784 /* ARGSUSED */ 1785 int 1786 sys_kill(struct thread *td, struct kill_args *uap) 1787 { 1788 1789 return (kern_kill(td, uap->pid, uap->signum)); 1790 } 1791 1792 int 1793 kern_kill(struct thread *td, pid_t pid, int signum) 1794 { 1795 ksiginfo_t ksi; 1796 struct proc *p; 1797 int error; 1798 1799 /* 1800 * A process in capability mode can send signals only to himself. 1801 * The main rationale behind this is that abort(3) is implemented as 1802 * kill(getpid(), SIGABRT). 1803 */ 1804 if (IN_CAPABILITY_MODE(td) && pid != td->td_proc->p_pid) 1805 return (ECAPMODE); 1806 1807 AUDIT_ARG_SIGNUM(signum); 1808 AUDIT_ARG_PID(pid); 1809 if ((u_int)signum > _SIG_MAXSIG) 1810 return (EINVAL); 1811 1812 ksiginfo_init(&ksi); 1813 ksi.ksi_signo = signum; 1814 ksi.ksi_code = SI_USER; 1815 ksi.ksi_pid = td->td_proc->p_pid; 1816 ksi.ksi_uid = td->td_ucred->cr_ruid; 1817 1818 if (pid > 0) { 1819 /* kill single process */ 1820 if ((p = pfind_any(pid)) == NULL) 1821 return (ESRCH); 1822 AUDIT_ARG_PROCESS(p); 1823 error = p_cansignal(td, p, signum); 1824 if (error == 0 && signum) 1825 pksignal(p, signum, &ksi); 1826 PROC_UNLOCK(p); 1827 return (error); 1828 } 1829 switch (pid) { 1830 case -1: /* broadcast signal */ 1831 return (killpg1(td, signum, 0, 1, &ksi)); 1832 case 0: /* signal own process group */ 1833 return (killpg1(td, signum, 0, 0, &ksi)); 1834 default: /* negative explicit process group */ 1835 return (killpg1(td, signum, -pid, 0, &ksi)); 1836 } 1837 /* NOTREACHED */ 1838 } 1839 1840 int 1841 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1842 { 1843 struct proc *p; 1844 int error; 1845 1846 AUDIT_ARG_SIGNUM(uap->signum); 1847 AUDIT_ARG_FD(uap->fd); 1848 if ((u_int)uap->signum > _SIG_MAXSIG) 1849 return (EINVAL); 1850 1851 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1852 if (error) 1853 return (error); 1854 AUDIT_ARG_PROCESS(p); 1855 error = p_cansignal(td, p, uap->signum); 1856 if (error == 0 && uap->signum) 1857 kern_psignal(p, uap->signum); 1858 PROC_UNLOCK(p); 1859 return (error); 1860 } 1861 1862 #if defined(COMPAT_43) 1863 #ifndef _SYS_SYSPROTO_H_ 1864 struct okillpg_args { 1865 int pgid; 1866 int signum; 1867 }; 1868 #endif 1869 /* ARGSUSED */ 1870 int 1871 okillpg(struct thread *td, struct okillpg_args *uap) 1872 { 1873 ksiginfo_t ksi; 1874 1875 AUDIT_ARG_SIGNUM(uap->signum); 1876 AUDIT_ARG_PID(uap->pgid); 1877 if ((u_int)uap->signum > _SIG_MAXSIG) 1878 return (EINVAL); 1879 1880 ksiginfo_init(&ksi); 1881 ksi.ksi_signo = uap->signum; 1882 ksi.ksi_code = SI_USER; 1883 ksi.ksi_pid = td->td_proc->p_pid; 1884 ksi.ksi_uid = td->td_ucred->cr_ruid; 1885 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1886 } 1887 #endif /* COMPAT_43 */ 1888 1889 #ifndef _SYS_SYSPROTO_H_ 1890 struct sigqueue_args { 1891 pid_t pid; 1892 int signum; 1893 /* union sigval */ void *value; 1894 }; 1895 #endif 1896 int 1897 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1898 { 1899 union sigval sv; 1900 1901 sv.sival_ptr = uap->value; 1902 1903 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1904 } 1905 1906 int 1907 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1908 { 1909 ksiginfo_t ksi; 1910 struct proc *p; 1911 int error; 1912 1913 if ((u_int)signum > _SIG_MAXSIG) 1914 return (EINVAL); 1915 1916 /* 1917 * Specification says sigqueue can only send signal to 1918 * single process. 1919 */ 1920 if (pid <= 0) 1921 return (EINVAL); 1922 1923 if ((p = pfind_any(pid)) == NULL) 1924 return (ESRCH); 1925 error = p_cansignal(td, p, signum); 1926 if (error == 0 && signum != 0) { 1927 ksiginfo_init(&ksi); 1928 ksi.ksi_flags = KSI_SIGQ; 1929 ksi.ksi_signo = signum; 1930 ksi.ksi_code = SI_QUEUE; 1931 ksi.ksi_pid = td->td_proc->p_pid; 1932 ksi.ksi_uid = td->td_ucred->cr_ruid; 1933 ksi.ksi_value = *value; 1934 error = pksignal(p, ksi.ksi_signo, &ksi); 1935 } 1936 PROC_UNLOCK(p); 1937 return (error); 1938 } 1939 1940 /* 1941 * Send a signal to a process group. 1942 */ 1943 void 1944 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1945 { 1946 struct pgrp *pgrp; 1947 1948 if (pgid != 0) { 1949 sx_slock(&proctree_lock); 1950 pgrp = pgfind(pgid); 1951 sx_sunlock(&proctree_lock); 1952 if (pgrp != NULL) { 1953 pgsignal(pgrp, sig, 0, ksi); 1954 PGRP_UNLOCK(pgrp); 1955 } 1956 } 1957 } 1958 1959 /* 1960 * Send a signal to a process group. If checktty is 1, 1961 * limit to members which have a controlling terminal. 1962 */ 1963 void 1964 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1965 { 1966 struct proc *p; 1967 1968 if (pgrp) { 1969 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1970 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1971 PROC_LOCK(p); 1972 if (p->p_state == PRS_NORMAL && 1973 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1974 pksignal(p, sig, ksi); 1975 PROC_UNLOCK(p); 1976 } 1977 } 1978 } 1979 1980 /* 1981 * Recalculate the signal mask and reset the signal disposition after 1982 * usermode frame for delivery is formed. Should be called after 1983 * mach-specific routine, because sysent->sv_sendsig() needs correct 1984 * ps_siginfo and signal mask. 1985 */ 1986 static void 1987 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1988 { 1989 sigset_t mask; 1990 1991 mtx_assert(&ps->ps_mtx, MA_OWNED); 1992 td->td_ru.ru_nsignals++; 1993 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1994 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1995 SIGADDSET(mask, sig); 1996 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1997 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1998 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1999 sigdflt(ps, sig); 2000 } 2001 2002 /* 2003 * Send a signal caused by a trap to the current thread. If it will be 2004 * caught immediately, deliver it with correct code. Otherwise, post it 2005 * normally. 2006 */ 2007 void 2008 trapsignal(struct thread *td, ksiginfo_t *ksi) 2009 { 2010 struct sigacts *ps; 2011 struct proc *p; 2012 sigset_t sigmask; 2013 int code, sig; 2014 2015 p = td->td_proc; 2016 sig = ksi->ksi_signo; 2017 code = ksi->ksi_code; 2018 KASSERT(_SIG_VALID(sig), ("invalid signal")); 2019 2020 sigfastblock_fetch(td); 2021 PROC_LOCK(p); 2022 ps = p->p_sigacts; 2023 mtx_lock(&ps->ps_mtx); 2024 sigmask = td->td_sigmask; 2025 if (td->td_sigblock_val != 0) 2026 SIGSETOR(sigmask, fastblock_mask); 2027 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 2028 !SIGISMEMBER(sigmask, sig)) { 2029 #ifdef KTRACE 2030 if (KTRPOINT(curthread, KTR_PSIG)) 2031 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 2032 &td->td_sigmask, code); 2033 #endif 2034 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 2035 ksi, &td->td_sigmask); 2036 postsig_done(sig, td, ps); 2037 mtx_unlock(&ps->ps_mtx); 2038 } else { 2039 /* 2040 * Avoid a possible infinite loop if the thread 2041 * masking the signal or process is ignoring the 2042 * signal. 2043 */ 2044 if (kern_forcesigexit && (SIGISMEMBER(sigmask, sig) || 2045 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2046 SIGDELSET(td->td_sigmask, sig); 2047 SIGDELSET(ps->ps_sigcatch, sig); 2048 SIGDELSET(ps->ps_sigignore, sig); 2049 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2050 td->td_pflags &= ~TDP_SIGFASTBLOCK; 2051 td->td_sigblock_val = 0; 2052 } 2053 mtx_unlock(&ps->ps_mtx); 2054 p->p_sig = sig; /* XXX to verify code */ 2055 tdsendsignal(p, td, sig, ksi); 2056 } 2057 PROC_UNLOCK(p); 2058 } 2059 2060 static struct thread * 2061 sigtd(struct proc *p, int sig, bool fast_sigblock) 2062 { 2063 struct thread *td, *signal_td; 2064 2065 PROC_LOCK_ASSERT(p, MA_OWNED); 2066 MPASS(!fast_sigblock || p == curproc); 2067 2068 /* 2069 * Check if current thread can handle the signal without 2070 * switching context to another thread. 2071 */ 2072 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig) && 2073 (!fast_sigblock || curthread->td_sigblock_val == 0)) 2074 return (curthread); 2075 signal_td = NULL; 2076 FOREACH_THREAD_IN_PROC(p, td) { 2077 if (!SIGISMEMBER(td->td_sigmask, sig) && (!fast_sigblock || 2078 td != curthread || td->td_sigblock_val == 0)) { 2079 signal_td = td; 2080 break; 2081 } 2082 } 2083 if (signal_td == NULL) 2084 signal_td = FIRST_THREAD_IN_PROC(p); 2085 return (signal_td); 2086 } 2087 2088 /* 2089 * Send the signal to the process. If the signal has an action, the action 2090 * is usually performed by the target process rather than the caller; we add 2091 * the signal to the set of pending signals for the process. 2092 * 2093 * Exceptions: 2094 * o When a stop signal is sent to a sleeping process that takes the 2095 * default action, the process is stopped without awakening it. 2096 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2097 * regardless of the signal action (eg, blocked or ignored). 2098 * 2099 * Other ignored signals are discarded immediately. 2100 * 2101 * NB: This function may be entered from the debugger via the "kill" DDB 2102 * command. There is little that can be done to mitigate the possibly messy 2103 * side effects of this unwise possibility. 2104 */ 2105 void 2106 kern_psignal(struct proc *p, int sig) 2107 { 2108 ksiginfo_t ksi; 2109 2110 ksiginfo_init(&ksi); 2111 ksi.ksi_signo = sig; 2112 ksi.ksi_code = SI_KERNEL; 2113 (void) tdsendsignal(p, NULL, sig, &ksi); 2114 } 2115 2116 int 2117 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2118 { 2119 2120 return (tdsendsignal(p, NULL, sig, ksi)); 2121 } 2122 2123 /* Utility function for finding a thread to send signal event to. */ 2124 int 2125 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2126 { 2127 struct thread *td; 2128 2129 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2130 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2131 if (td == NULL) 2132 return (ESRCH); 2133 *ttd = td; 2134 } else { 2135 *ttd = NULL; 2136 PROC_LOCK(p); 2137 } 2138 return (0); 2139 } 2140 2141 void 2142 tdsignal(struct thread *td, int sig) 2143 { 2144 ksiginfo_t ksi; 2145 2146 ksiginfo_init(&ksi); 2147 ksi.ksi_signo = sig; 2148 ksi.ksi_code = SI_KERNEL; 2149 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2150 } 2151 2152 void 2153 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2154 { 2155 2156 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2157 } 2158 2159 static int 2160 sig_sleepq_abort(struct thread *td, int intrval) 2161 { 2162 THREAD_LOCK_ASSERT(td, MA_OWNED); 2163 2164 if (intrval == 0 && (td->td_flags & TDF_SIGWAIT) == 0) { 2165 thread_unlock(td); 2166 return (0); 2167 } 2168 return (sleepq_abort(td, intrval)); 2169 } 2170 2171 int 2172 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2173 { 2174 sig_t action; 2175 sigqueue_t *sigqueue; 2176 int prop; 2177 struct sigacts *ps; 2178 int intrval; 2179 int ret = 0; 2180 int wakeup_swapper; 2181 2182 MPASS(td == NULL || p == td->td_proc); 2183 PROC_LOCK_ASSERT(p, MA_OWNED); 2184 2185 if (!_SIG_VALID(sig)) 2186 panic("%s(): invalid signal %d", __func__, sig); 2187 2188 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2189 2190 /* 2191 * IEEE Std 1003.1-2001: return success when killing a zombie. 2192 */ 2193 if (p->p_state == PRS_ZOMBIE) { 2194 if (ksi && (ksi->ksi_flags & KSI_INS)) 2195 ksiginfo_tryfree(ksi); 2196 return (ret); 2197 } 2198 2199 ps = p->p_sigacts; 2200 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2201 prop = sigprop(sig); 2202 2203 if (td == NULL) { 2204 td = sigtd(p, sig, false); 2205 sigqueue = &p->p_sigqueue; 2206 } else 2207 sigqueue = &td->td_sigqueue; 2208 2209 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2210 2211 /* 2212 * If the signal is being ignored, then we forget about it 2213 * immediately, except when the target process executes 2214 * sigwait(). (Note: we don't set SIGCONT in ps_sigignore, 2215 * and if it is set to SIG_IGN, action will be SIG_DFL here.) 2216 */ 2217 mtx_lock(&ps->ps_mtx); 2218 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2219 if (kern_sig_discard_ign && 2220 (p->p_sysent->sv_flags & SV_SIG_DISCIGN) == 0) { 2221 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2222 2223 mtx_unlock(&ps->ps_mtx); 2224 if (ksi && (ksi->ksi_flags & KSI_INS)) 2225 ksiginfo_tryfree(ksi); 2226 return (ret); 2227 } else { 2228 action = SIG_CATCH; 2229 intrval = 0; 2230 } 2231 } else { 2232 if (SIGISMEMBER(td->td_sigmask, sig)) 2233 action = SIG_HOLD; 2234 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2235 action = SIG_CATCH; 2236 else 2237 action = SIG_DFL; 2238 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2239 intrval = EINTR; 2240 else 2241 intrval = ERESTART; 2242 } 2243 mtx_unlock(&ps->ps_mtx); 2244 2245 if (prop & SIGPROP_CONT) 2246 sigqueue_delete_stopmask_proc(p); 2247 else if (prop & SIGPROP_STOP) { 2248 /* 2249 * If sending a tty stop signal to a member of an orphaned 2250 * process group, discard the signal here if the action 2251 * is default; don't stop the process below if sleeping, 2252 * and don't clear any pending SIGCONT. 2253 */ 2254 if ((prop & SIGPROP_TTYSTOP) != 0 && 2255 (p->p_pgrp->pg_flags & PGRP_ORPHANED) != 0 && 2256 action == SIG_DFL) { 2257 if (ksi && (ksi->ksi_flags & KSI_INS)) 2258 ksiginfo_tryfree(ksi); 2259 return (ret); 2260 } 2261 sigqueue_delete_proc(p, SIGCONT); 2262 if (p->p_flag & P_CONTINUED) { 2263 p->p_flag &= ~P_CONTINUED; 2264 PROC_LOCK(p->p_pptr); 2265 sigqueue_take(p->p_ksi); 2266 PROC_UNLOCK(p->p_pptr); 2267 } 2268 } 2269 2270 ret = sigqueue_add(sigqueue, sig, ksi); 2271 if (ret != 0) 2272 return (ret); 2273 signotify(td); 2274 /* 2275 * Defer further processing for signals which are held, 2276 * except that stopped processes must be continued by SIGCONT. 2277 */ 2278 if (action == SIG_HOLD && 2279 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2280 return (ret); 2281 2282 wakeup_swapper = 0; 2283 2284 /* 2285 * Some signals have a process-wide effect and a per-thread 2286 * component. Most processing occurs when the process next 2287 * tries to cross the user boundary, however there are some 2288 * times when processing needs to be done immediately, such as 2289 * waking up threads so that they can cross the user boundary. 2290 * We try to do the per-process part here. 2291 */ 2292 if (P_SHOULDSTOP(p)) { 2293 KASSERT(!(p->p_flag & P_WEXIT), 2294 ("signal to stopped but exiting process")); 2295 if (sig == SIGKILL) { 2296 /* 2297 * If traced process is already stopped, 2298 * then no further action is necessary. 2299 */ 2300 if (p->p_flag & P_TRACED) 2301 goto out; 2302 /* 2303 * SIGKILL sets process running. 2304 * It will die elsewhere. 2305 * All threads must be restarted. 2306 */ 2307 p->p_flag &= ~P_STOPPED_SIG; 2308 goto runfast; 2309 } 2310 2311 if (prop & SIGPROP_CONT) { 2312 /* 2313 * If traced process is already stopped, 2314 * then no further action is necessary. 2315 */ 2316 if (p->p_flag & P_TRACED) 2317 goto out; 2318 /* 2319 * If SIGCONT is default (or ignored), we continue the 2320 * process but don't leave the signal in sigqueue as 2321 * it has no further action. If SIGCONT is held, we 2322 * continue the process and leave the signal in 2323 * sigqueue. If the process catches SIGCONT, let it 2324 * handle the signal itself. If it isn't waiting on 2325 * an event, it goes back to run state. 2326 * Otherwise, process goes back to sleep state. 2327 */ 2328 p->p_flag &= ~P_STOPPED_SIG; 2329 PROC_SLOCK(p); 2330 if (p->p_numthreads == p->p_suspcount) { 2331 PROC_SUNLOCK(p); 2332 p->p_flag |= P_CONTINUED; 2333 p->p_xsig = SIGCONT; 2334 PROC_LOCK(p->p_pptr); 2335 childproc_continued(p); 2336 PROC_UNLOCK(p->p_pptr); 2337 PROC_SLOCK(p); 2338 } 2339 if (action == SIG_DFL) { 2340 thread_unsuspend(p); 2341 PROC_SUNLOCK(p); 2342 sigqueue_delete(sigqueue, sig); 2343 goto out_cont; 2344 } 2345 if (action == SIG_CATCH) { 2346 /* 2347 * The process wants to catch it so it needs 2348 * to run at least one thread, but which one? 2349 */ 2350 PROC_SUNLOCK(p); 2351 goto runfast; 2352 } 2353 /* 2354 * The signal is not ignored or caught. 2355 */ 2356 thread_unsuspend(p); 2357 PROC_SUNLOCK(p); 2358 goto out_cont; 2359 } 2360 2361 if (prop & SIGPROP_STOP) { 2362 /* 2363 * If traced process is already stopped, 2364 * then no further action is necessary. 2365 */ 2366 if (p->p_flag & P_TRACED) 2367 goto out; 2368 /* 2369 * Already stopped, don't need to stop again 2370 * (If we did the shell could get confused). 2371 * Just make sure the signal STOP bit set. 2372 */ 2373 p->p_flag |= P_STOPPED_SIG; 2374 sigqueue_delete(sigqueue, sig); 2375 goto out; 2376 } 2377 2378 /* 2379 * All other kinds of signals: 2380 * If a thread is sleeping interruptibly, simulate a 2381 * wakeup so that when it is continued it will be made 2382 * runnable and can look at the signal. However, don't make 2383 * the PROCESS runnable, leave it stopped. 2384 * It may run a bit until it hits a thread_suspend_check(). 2385 */ 2386 PROC_SLOCK(p); 2387 thread_lock(td); 2388 if (TD_CAN_ABORT(td)) 2389 wakeup_swapper = sig_sleepq_abort(td, intrval); 2390 else 2391 thread_unlock(td); 2392 PROC_SUNLOCK(p); 2393 goto out; 2394 /* 2395 * Mutexes are short lived. Threads waiting on them will 2396 * hit thread_suspend_check() soon. 2397 */ 2398 } else if (p->p_state == PRS_NORMAL) { 2399 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2400 tdsigwakeup(td, sig, action, intrval); 2401 goto out; 2402 } 2403 2404 MPASS(action == SIG_DFL); 2405 2406 if (prop & SIGPROP_STOP) { 2407 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2408 goto out; 2409 p->p_flag |= P_STOPPED_SIG; 2410 p->p_xsig = sig; 2411 PROC_SLOCK(p); 2412 wakeup_swapper = sig_suspend_threads(td, p, 1); 2413 if (p->p_numthreads == p->p_suspcount) { 2414 /* 2415 * only thread sending signal to another 2416 * process can reach here, if thread is sending 2417 * signal to its process, because thread does 2418 * not suspend itself here, p_numthreads 2419 * should never be equal to p_suspcount. 2420 */ 2421 thread_stopped(p); 2422 PROC_SUNLOCK(p); 2423 sigqueue_delete_proc(p, p->p_xsig); 2424 } else 2425 PROC_SUNLOCK(p); 2426 goto out; 2427 } 2428 } else { 2429 /* Not in "NORMAL" state. discard the signal. */ 2430 sigqueue_delete(sigqueue, sig); 2431 goto out; 2432 } 2433 2434 /* 2435 * The process is not stopped so we need to apply the signal to all the 2436 * running threads. 2437 */ 2438 runfast: 2439 tdsigwakeup(td, sig, action, intrval); 2440 PROC_SLOCK(p); 2441 thread_unsuspend(p); 2442 PROC_SUNLOCK(p); 2443 out_cont: 2444 itimer_proc_continue(p); 2445 kqtimer_proc_continue(p); 2446 out: 2447 /* If we jump here, proc slock should not be owned. */ 2448 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2449 if (wakeup_swapper) 2450 kick_proc0(); 2451 2452 return (ret); 2453 } 2454 2455 /* 2456 * The force of a signal has been directed against a single 2457 * thread. We need to see what we can do about knocking it 2458 * out of any sleep it may be in etc. 2459 */ 2460 static void 2461 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2462 { 2463 struct proc *p = td->td_proc; 2464 int prop, wakeup_swapper; 2465 2466 PROC_LOCK_ASSERT(p, MA_OWNED); 2467 prop = sigprop(sig); 2468 2469 PROC_SLOCK(p); 2470 thread_lock(td); 2471 /* 2472 * Bring the priority of a thread up if we want it to get 2473 * killed in this lifetime. Be careful to avoid bumping the 2474 * priority of the idle thread, since we still allow to signal 2475 * kernel processes. 2476 */ 2477 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2478 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2479 sched_prio(td, PUSER); 2480 if (TD_ON_SLEEPQ(td)) { 2481 /* 2482 * If thread is sleeping uninterruptibly 2483 * we can't interrupt the sleep... the signal will 2484 * be noticed when the process returns through 2485 * trap() or syscall(). 2486 */ 2487 if ((td->td_flags & TDF_SINTR) == 0) 2488 goto out; 2489 /* 2490 * If SIGCONT is default (or ignored) and process is 2491 * asleep, we are finished; the process should not 2492 * be awakened. 2493 */ 2494 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2495 thread_unlock(td); 2496 PROC_SUNLOCK(p); 2497 sigqueue_delete(&p->p_sigqueue, sig); 2498 /* 2499 * It may be on either list in this state. 2500 * Remove from both for now. 2501 */ 2502 sigqueue_delete(&td->td_sigqueue, sig); 2503 return; 2504 } 2505 2506 /* 2507 * Don't awaken a sleeping thread for SIGSTOP if the 2508 * STOP signal is deferred. 2509 */ 2510 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2511 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2512 goto out; 2513 2514 /* 2515 * Give low priority threads a better chance to run. 2516 */ 2517 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2518 sched_prio(td, PUSER); 2519 2520 wakeup_swapper = sig_sleepq_abort(td, intrval); 2521 PROC_SUNLOCK(p); 2522 if (wakeup_swapper) 2523 kick_proc0(); 2524 return; 2525 } 2526 2527 /* 2528 * Other states do nothing with the signal immediately, 2529 * other than kicking ourselves if we are running. 2530 * It will either never be noticed, or noticed very soon. 2531 */ 2532 #ifdef SMP 2533 if (TD_IS_RUNNING(td) && td != curthread) 2534 forward_signal(td); 2535 #endif 2536 2537 out: 2538 PROC_SUNLOCK(p); 2539 thread_unlock(td); 2540 } 2541 2542 static void 2543 ptrace_coredump(struct thread *td) 2544 { 2545 struct proc *p; 2546 struct thr_coredump_req *tcq; 2547 void *rl_cookie; 2548 2549 MPASS(td == curthread); 2550 p = td->td_proc; 2551 PROC_LOCK_ASSERT(p, MA_OWNED); 2552 if ((td->td_dbgflags & TDB_COREDUMPRQ) == 0) 2553 return; 2554 KASSERT((p->p_flag & P_STOPPED_TRACE) != 0, ("not stopped")); 2555 2556 tcq = td->td_coredump; 2557 KASSERT(tcq != NULL, ("td_coredump is NULL")); 2558 2559 if (p->p_sysent->sv_coredump == NULL) { 2560 tcq->tc_error = ENOSYS; 2561 goto wake; 2562 } 2563 2564 PROC_UNLOCK(p); 2565 rl_cookie = vn_rangelock_wlock(tcq->tc_vp, 0, OFF_MAX); 2566 2567 tcq->tc_error = p->p_sysent->sv_coredump(td, tcq->tc_vp, 2568 tcq->tc_limit, tcq->tc_flags); 2569 2570 vn_rangelock_unlock(tcq->tc_vp, rl_cookie); 2571 PROC_LOCK(p); 2572 wake: 2573 td->td_dbgflags &= ~TDB_COREDUMPRQ; 2574 td->td_coredump = NULL; 2575 wakeup(p); 2576 } 2577 2578 static int 2579 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2580 { 2581 struct thread *td2; 2582 int wakeup_swapper; 2583 2584 PROC_LOCK_ASSERT(p, MA_OWNED); 2585 PROC_SLOCK_ASSERT(p, MA_OWNED); 2586 MPASS(sending || td == curthread); 2587 2588 wakeup_swapper = 0; 2589 FOREACH_THREAD_IN_PROC(p, td2) { 2590 thread_lock(td2); 2591 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2592 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2593 (td2->td_flags & TDF_SINTR)) { 2594 if (td2->td_flags & TDF_SBDRY) { 2595 /* 2596 * Once a thread is asleep with 2597 * TDF_SBDRY and without TDF_SERESTART 2598 * or TDF_SEINTR set, it should never 2599 * become suspended due to this check. 2600 */ 2601 KASSERT(!TD_IS_SUSPENDED(td2), 2602 ("thread with deferred stops suspended")); 2603 if (TD_SBDRY_INTR(td2)) { 2604 wakeup_swapper |= sleepq_abort(td2, 2605 TD_SBDRY_ERRNO(td2)); 2606 continue; 2607 } 2608 } else if (!TD_IS_SUSPENDED(td2)) 2609 thread_suspend_one(td2); 2610 } else if (!TD_IS_SUSPENDED(td2)) { 2611 if (sending || td != td2) 2612 td2->td_flags |= TDF_ASTPENDING; 2613 #ifdef SMP 2614 if (TD_IS_RUNNING(td2) && td2 != td) 2615 forward_signal(td2); 2616 #endif 2617 } 2618 thread_unlock(td2); 2619 } 2620 return (wakeup_swapper); 2621 } 2622 2623 /* 2624 * Stop the process for an event deemed interesting to the debugger. If si is 2625 * non-NULL, this is a signal exchange; the new signal requested by the 2626 * debugger will be returned for handling. If si is NULL, this is some other 2627 * type of interesting event. The debugger may request a signal be delivered in 2628 * that case as well, however it will be deferred until it can be handled. 2629 */ 2630 int 2631 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2632 { 2633 struct proc *p = td->td_proc; 2634 struct thread *td2; 2635 ksiginfo_t ksi; 2636 2637 PROC_LOCK_ASSERT(p, MA_OWNED); 2638 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2639 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2640 &p->p_mtx.lock_object, "Stopping for traced signal"); 2641 2642 td->td_xsig = sig; 2643 2644 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2645 td->td_dbgflags |= TDB_XSIG; 2646 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2647 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2648 PROC_SLOCK(p); 2649 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2650 if (P_KILLED(p)) { 2651 /* 2652 * Ensure that, if we've been PT_KILLed, the 2653 * exit status reflects that. Another thread 2654 * may also be in ptracestop(), having just 2655 * received the SIGKILL, but this thread was 2656 * unsuspended first. 2657 */ 2658 td->td_dbgflags &= ~TDB_XSIG; 2659 td->td_xsig = SIGKILL; 2660 p->p_ptevents = 0; 2661 break; 2662 } 2663 if (p->p_flag & P_SINGLE_EXIT && 2664 !(td->td_dbgflags & TDB_EXIT)) { 2665 /* 2666 * Ignore ptrace stops except for thread exit 2667 * events when the process exits. 2668 */ 2669 td->td_dbgflags &= ~TDB_XSIG; 2670 PROC_SUNLOCK(p); 2671 return (0); 2672 } 2673 2674 /* 2675 * Make wait(2) work. Ensure that right after the 2676 * attach, the thread which was decided to become the 2677 * leader of attach gets reported to the waiter. 2678 * Otherwise, just avoid overwriting another thread's 2679 * assignment to p_xthread. If another thread has 2680 * already set p_xthread, the current thread will get 2681 * a chance to report itself upon the next iteration. 2682 */ 2683 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2684 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2685 p->p_xthread == NULL)) { 2686 p->p_xsig = sig; 2687 p->p_xthread = td; 2688 2689 /* 2690 * If we are on sleepqueue already, 2691 * let sleepqueue code decide if it 2692 * needs to go sleep after attach. 2693 */ 2694 if (td->td_wchan == NULL) 2695 td->td_dbgflags &= ~TDB_FSTP; 2696 2697 p->p_flag2 &= ~P2_PTRACE_FSTP; 2698 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2699 sig_suspend_threads(td, p, 0); 2700 } 2701 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2702 td->td_dbgflags &= ~TDB_STOPATFORK; 2703 } 2704 stopme: 2705 td->td_dbgflags |= TDB_SSWITCH; 2706 thread_suspend_switch(td, p); 2707 td->td_dbgflags &= ~TDB_SSWITCH; 2708 if ((td->td_dbgflags & TDB_COREDUMPRQ) != 0) { 2709 PROC_SUNLOCK(p); 2710 ptrace_coredump(td); 2711 PROC_SLOCK(p); 2712 goto stopme; 2713 } 2714 if (p->p_xthread == td) 2715 p->p_xthread = NULL; 2716 if (!(p->p_flag & P_TRACED)) 2717 break; 2718 if (td->td_dbgflags & TDB_SUSPEND) { 2719 if (p->p_flag & P_SINGLE_EXIT) 2720 break; 2721 goto stopme; 2722 } 2723 } 2724 PROC_SUNLOCK(p); 2725 } 2726 2727 if (si != NULL && sig == td->td_xsig) { 2728 /* Parent wants us to take the original signal unchanged. */ 2729 si->ksi_flags |= KSI_HEAD; 2730 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2731 si->ksi_signo = 0; 2732 } else if (td->td_xsig != 0) { 2733 /* 2734 * If parent wants us to take a new signal, then it will leave 2735 * it in td->td_xsig; otherwise we just look for signals again. 2736 */ 2737 ksiginfo_init(&ksi); 2738 ksi.ksi_signo = td->td_xsig; 2739 ksi.ksi_flags |= KSI_PTRACE; 2740 td2 = sigtd(p, td->td_xsig, false); 2741 tdsendsignal(p, td2, td->td_xsig, &ksi); 2742 if (td != td2) 2743 return (0); 2744 } 2745 2746 return (td->td_xsig); 2747 } 2748 2749 static void 2750 reschedule_signals(struct proc *p, sigset_t block, int flags) 2751 { 2752 struct sigacts *ps; 2753 struct thread *td; 2754 int sig; 2755 bool fastblk, pslocked; 2756 2757 PROC_LOCK_ASSERT(p, MA_OWNED); 2758 ps = p->p_sigacts; 2759 pslocked = (flags & SIGPROCMASK_PS_LOCKED) != 0; 2760 mtx_assert(&ps->ps_mtx, pslocked ? MA_OWNED : MA_NOTOWNED); 2761 if (SIGISEMPTY(p->p_siglist)) 2762 return; 2763 SIGSETAND(block, p->p_siglist); 2764 fastblk = (flags & SIGPROCMASK_FASTBLK) != 0; 2765 while ((sig = sig_ffs(&block)) != 0) { 2766 SIGDELSET(block, sig); 2767 td = sigtd(p, sig, fastblk); 2768 2769 /* 2770 * If sigtd() selected us despite sigfastblock is 2771 * blocking, do not activate AST or wake us, to avoid 2772 * loop in AST handler. 2773 */ 2774 if (fastblk && td == curthread) 2775 continue; 2776 2777 signotify(td); 2778 if (!pslocked) 2779 mtx_lock(&ps->ps_mtx); 2780 if (p->p_flag & P_TRACED || 2781 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2782 !SIGISMEMBER(td->td_sigmask, sig))) { 2783 tdsigwakeup(td, sig, SIG_CATCH, 2784 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2785 ERESTART)); 2786 } 2787 if (!pslocked) 2788 mtx_unlock(&ps->ps_mtx); 2789 } 2790 } 2791 2792 void 2793 tdsigcleanup(struct thread *td) 2794 { 2795 struct proc *p; 2796 sigset_t unblocked; 2797 2798 p = td->td_proc; 2799 PROC_LOCK_ASSERT(p, MA_OWNED); 2800 2801 sigqueue_flush(&td->td_sigqueue); 2802 if (p->p_numthreads == 1) 2803 return; 2804 2805 /* 2806 * Since we cannot handle signals, notify signal post code 2807 * about this by filling the sigmask. 2808 * 2809 * Also, if needed, wake up thread(s) that do not block the 2810 * same signals as the exiting thread, since the thread might 2811 * have been selected for delivery and woken up. 2812 */ 2813 SIGFILLSET(unblocked); 2814 SIGSETNAND(unblocked, td->td_sigmask); 2815 SIGFILLSET(td->td_sigmask); 2816 reschedule_signals(p, unblocked, 0); 2817 2818 } 2819 2820 static int 2821 sigdeferstop_curr_flags(int cflags) 2822 { 2823 2824 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2825 (cflags & TDF_SBDRY) != 0); 2826 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2827 } 2828 2829 /* 2830 * Defer the delivery of SIGSTOP for the current thread, according to 2831 * the requested mode. Returns previous flags, which must be restored 2832 * by sigallowstop(). 2833 * 2834 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2835 * cleared by the current thread, which allow the lock-less read-only 2836 * accesses below. 2837 */ 2838 int 2839 sigdeferstop_impl(int mode) 2840 { 2841 struct thread *td; 2842 int cflags, nflags; 2843 2844 td = curthread; 2845 cflags = sigdeferstop_curr_flags(td->td_flags); 2846 switch (mode) { 2847 case SIGDEFERSTOP_NOP: 2848 nflags = cflags; 2849 break; 2850 case SIGDEFERSTOP_OFF: 2851 nflags = 0; 2852 break; 2853 case SIGDEFERSTOP_SILENT: 2854 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2855 break; 2856 case SIGDEFERSTOP_EINTR: 2857 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2858 break; 2859 case SIGDEFERSTOP_ERESTART: 2860 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2861 break; 2862 default: 2863 panic("sigdeferstop: invalid mode %x", mode); 2864 break; 2865 } 2866 if (cflags == nflags) 2867 return (SIGDEFERSTOP_VAL_NCHG); 2868 thread_lock(td); 2869 td->td_flags = (td->td_flags & ~cflags) | nflags; 2870 thread_unlock(td); 2871 return (cflags); 2872 } 2873 2874 /* 2875 * Restores the STOP handling mode, typically permitting the delivery 2876 * of SIGSTOP for the current thread. This does not immediately 2877 * suspend if a stop was posted. Instead, the thread will suspend 2878 * either via ast() or a subsequent interruptible sleep. 2879 */ 2880 void 2881 sigallowstop_impl(int prev) 2882 { 2883 struct thread *td; 2884 int cflags; 2885 2886 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2887 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2888 ("sigallowstop: incorrect previous mode %x", prev)); 2889 td = curthread; 2890 cflags = sigdeferstop_curr_flags(td->td_flags); 2891 if (cflags != prev) { 2892 thread_lock(td); 2893 td->td_flags = (td->td_flags & ~cflags) | prev; 2894 thread_unlock(td); 2895 } 2896 } 2897 2898 /* 2899 * If the current process has received a signal (should be caught or cause 2900 * termination, should interrupt current syscall), return the signal number. 2901 * Stop signals with default action are processed immediately, then cleared; 2902 * they aren't returned. This is checked after each entry to the system for 2903 * a syscall or trap (though this can usually be done without calling issignal 2904 * by checking the pending signal masks in cursig.) The normal call 2905 * sequence is 2906 * 2907 * while (sig = cursig(curthread)) 2908 * postsig(sig); 2909 */ 2910 static int 2911 issignal(struct thread *td) 2912 { 2913 struct proc *p; 2914 struct sigacts *ps; 2915 struct sigqueue *queue; 2916 sigset_t sigpending; 2917 ksiginfo_t ksi; 2918 int prop, sig; 2919 2920 p = td->td_proc; 2921 ps = p->p_sigacts; 2922 mtx_assert(&ps->ps_mtx, MA_OWNED); 2923 PROC_LOCK_ASSERT(p, MA_OWNED); 2924 for (;;) { 2925 sigpending = td->td_sigqueue.sq_signals; 2926 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2927 SIGSETNAND(sigpending, td->td_sigmask); 2928 2929 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2930 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2931 SIG_STOPSIGMASK(sigpending); 2932 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2933 return (0); 2934 2935 /* 2936 * Do fast sigblock if requested by usermode. Since 2937 * we do know that there was a signal pending at this 2938 * point, set the FAST_SIGBLOCK_PEND as indicator for 2939 * usermode to perform a dummy call to 2940 * FAST_SIGBLOCK_UNBLOCK, which causes immediate 2941 * delivery of postponed pending signal. 2942 */ 2943 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 2944 if (td->td_sigblock_val != 0) 2945 SIGSETNAND(sigpending, fastblock_mask); 2946 if (SIGISEMPTY(sigpending)) { 2947 td->td_pflags |= TDP_SIGFASTPENDING; 2948 return (0); 2949 } 2950 } 2951 2952 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2953 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2954 SIGISMEMBER(sigpending, SIGSTOP)) { 2955 /* 2956 * If debugger just attached, always consume 2957 * SIGSTOP from ptrace(PT_ATTACH) first, to 2958 * execute the debugger attach ritual in 2959 * order. 2960 */ 2961 sig = SIGSTOP; 2962 td->td_dbgflags |= TDB_FSTP; 2963 } else { 2964 sig = sig_ffs(&sigpending); 2965 } 2966 2967 /* 2968 * We should allow pending but ignored signals below 2969 * only if there is sigwait() active, or P_TRACED was 2970 * on when they were posted. 2971 */ 2972 if (SIGISMEMBER(ps->ps_sigignore, sig) && 2973 (p->p_flag & P_TRACED) == 0 && 2974 (td->td_flags & TDF_SIGWAIT) == 0) { 2975 sigqueue_delete(&td->td_sigqueue, sig); 2976 sigqueue_delete(&p->p_sigqueue, sig); 2977 continue; 2978 } 2979 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2980 /* 2981 * If traced, always stop. 2982 * Remove old signal from queue before the stop. 2983 * XXX shrug off debugger, it causes siginfo to 2984 * be thrown away. 2985 */ 2986 queue = &td->td_sigqueue; 2987 ksiginfo_init(&ksi); 2988 if (sigqueue_get(queue, sig, &ksi) == 0) { 2989 queue = &p->p_sigqueue; 2990 sigqueue_get(queue, sig, &ksi); 2991 } 2992 td->td_si = ksi.ksi_info; 2993 2994 mtx_unlock(&ps->ps_mtx); 2995 sig = ptracestop(td, sig, &ksi); 2996 mtx_lock(&ps->ps_mtx); 2997 2998 td->td_si.si_signo = 0; 2999 3000 /* 3001 * Keep looking if the debugger discarded or 3002 * replaced the signal. 3003 */ 3004 if (sig == 0) 3005 continue; 3006 3007 /* 3008 * If the signal became masked, re-queue it. 3009 */ 3010 if (SIGISMEMBER(td->td_sigmask, sig)) { 3011 ksi.ksi_flags |= KSI_HEAD; 3012 sigqueue_add(&p->p_sigqueue, sig, &ksi); 3013 continue; 3014 } 3015 3016 /* 3017 * If the traced bit got turned off, requeue 3018 * the signal and go back up to the top to 3019 * rescan signals. This ensures that p_sig* 3020 * and p_sigact are consistent. 3021 */ 3022 if ((p->p_flag & P_TRACED) == 0) { 3023 ksi.ksi_flags |= KSI_HEAD; 3024 sigqueue_add(queue, sig, &ksi); 3025 continue; 3026 } 3027 } 3028 3029 prop = sigprop(sig); 3030 3031 /* 3032 * Decide whether the signal should be returned. 3033 * Return the signal's number, or fall through 3034 * to clear it from the pending mask. 3035 */ 3036 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 3037 case (intptr_t)SIG_DFL: 3038 /* 3039 * Don't take default actions on system processes. 3040 */ 3041 if (p->p_pid <= 1) { 3042 #ifdef DIAGNOSTIC 3043 /* 3044 * Are you sure you want to ignore SIGSEGV 3045 * in init? XXX 3046 */ 3047 printf("Process (pid %lu) got signal %d\n", 3048 (u_long)p->p_pid, sig); 3049 #endif 3050 break; /* == ignore */ 3051 } 3052 /* 3053 * If there is a pending stop signal to process with 3054 * default action, stop here, then clear the signal. 3055 * Traced or exiting processes should ignore stops. 3056 * Additionally, a member of an orphaned process group 3057 * should ignore tty stops. 3058 */ 3059 if (prop & SIGPROP_STOP) { 3060 mtx_unlock(&ps->ps_mtx); 3061 if ((p->p_flag & (P_TRACED | P_WEXIT | 3062 P_SINGLE_EXIT)) != 0 || ((p->p_pgrp-> 3063 pg_flags & PGRP_ORPHANED) != 0 && 3064 (prop & SIGPROP_TTYSTOP) != 0)) { 3065 mtx_lock(&ps->ps_mtx); 3066 break; /* == ignore */ 3067 } 3068 if (TD_SBDRY_INTR(td)) { 3069 KASSERT((td->td_flags & TDF_SBDRY) != 0, 3070 ("lost TDF_SBDRY")); 3071 mtx_lock(&ps->ps_mtx); 3072 return (-1); 3073 } 3074 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 3075 &p->p_mtx.lock_object, "Catching SIGSTOP"); 3076 sigqueue_delete(&td->td_sigqueue, sig); 3077 sigqueue_delete(&p->p_sigqueue, sig); 3078 p->p_flag |= P_STOPPED_SIG; 3079 p->p_xsig = sig; 3080 PROC_SLOCK(p); 3081 sig_suspend_threads(td, p, 0); 3082 thread_suspend_switch(td, p); 3083 PROC_SUNLOCK(p); 3084 mtx_lock(&ps->ps_mtx); 3085 goto next; 3086 } else if ((prop & SIGPROP_IGNORE) != 0 && 3087 (td->td_flags & TDF_SIGWAIT) == 0) { 3088 /* 3089 * Default action is to ignore; drop it if 3090 * not in kern_sigtimedwait(). 3091 */ 3092 break; /* == ignore */ 3093 } else 3094 return (sig); 3095 /*NOTREACHED*/ 3096 3097 case (intptr_t)SIG_IGN: 3098 if ((td->td_flags & TDF_SIGWAIT) == 0) 3099 break; /* == ignore */ 3100 else 3101 return (sig); 3102 3103 default: 3104 /* 3105 * This signal has an action, let 3106 * postsig() process it. 3107 */ 3108 return (sig); 3109 } 3110 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 3111 sigqueue_delete(&p->p_sigqueue, sig); 3112 next:; 3113 } 3114 /* NOTREACHED */ 3115 } 3116 3117 void 3118 thread_stopped(struct proc *p) 3119 { 3120 int n; 3121 3122 PROC_LOCK_ASSERT(p, MA_OWNED); 3123 PROC_SLOCK_ASSERT(p, MA_OWNED); 3124 n = p->p_suspcount; 3125 if (p == curproc) 3126 n++; 3127 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 3128 PROC_SUNLOCK(p); 3129 p->p_flag &= ~P_WAITED; 3130 PROC_LOCK(p->p_pptr); 3131 childproc_stopped(p, (p->p_flag & P_TRACED) ? 3132 CLD_TRAPPED : CLD_STOPPED); 3133 PROC_UNLOCK(p->p_pptr); 3134 PROC_SLOCK(p); 3135 } 3136 } 3137 3138 /* 3139 * Take the action for the specified signal 3140 * from the current set of pending signals. 3141 */ 3142 int 3143 postsig(int sig) 3144 { 3145 struct thread *td; 3146 struct proc *p; 3147 struct sigacts *ps; 3148 sig_t action; 3149 ksiginfo_t ksi; 3150 sigset_t returnmask; 3151 3152 KASSERT(sig != 0, ("postsig")); 3153 3154 td = curthread; 3155 p = td->td_proc; 3156 PROC_LOCK_ASSERT(p, MA_OWNED); 3157 ps = p->p_sigacts; 3158 mtx_assert(&ps->ps_mtx, MA_OWNED); 3159 ksiginfo_init(&ksi); 3160 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3161 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3162 return (0); 3163 ksi.ksi_signo = sig; 3164 if (ksi.ksi_code == SI_TIMER) 3165 itimer_accept(p, ksi.ksi_timerid, &ksi); 3166 action = ps->ps_sigact[_SIG_IDX(sig)]; 3167 #ifdef KTRACE 3168 if (KTRPOINT(td, KTR_PSIG)) 3169 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3170 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3171 #endif 3172 3173 if (action == SIG_DFL) { 3174 /* 3175 * Default action, where the default is to kill 3176 * the process. (Other cases were ignored above.) 3177 */ 3178 mtx_unlock(&ps->ps_mtx); 3179 proc_td_siginfo_capture(td, &ksi.ksi_info); 3180 sigexit(td, sig); 3181 /* NOTREACHED */ 3182 } else { 3183 /* 3184 * If we get here, the signal must be caught. 3185 */ 3186 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3187 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3188 ("postsig action: blocked sig %d", sig)); 3189 3190 /* 3191 * Set the new mask value and also defer further 3192 * occurrences of this signal. 3193 * 3194 * Special case: user has done a sigsuspend. Here the 3195 * current mask is not of interest, but rather the 3196 * mask from before the sigsuspend is what we want 3197 * restored after the signal processing is completed. 3198 */ 3199 if (td->td_pflags & TDP_OLDMASK) { 3200 returnmask = td->td_oldsigmask; 3201 td->td_pflags &= ~TDP_OLDMASK; 3202 } else 3203 returnmask = td->td_sigmask; 3204 3205 if (p->p_sig == sig) { 3206 p->p_sig = 0; 3207 } 3208 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3209 postsig_done(sig, td, ps); 3210 } 3211 return (1); 3212 } 3213 3214 int 3215 sig_ast_checksusp(struct thread *td) 3216 { 3217 struct proc *p; 3218 int ret; 3219 3220 p = td->td_proc; 3221 PROC_LOCK_ASSERT(p, MA_OWNED); 3222 3223 if ((td->td_flags & TDF_NEEDSUSPCHK) == 0) 3224 return (0); 3225 3226 ret = thread_suspend_check(1); 3227 MPASS(ret == 0 || ret == EINTR || ret == ERESTART); 3228 return (ret); 3229 } 3230 3231 int 3232 sig_ast_needsigchk(struct thread *td) 3233 { 3234 struct proc *p; 3235 struct sigacts *ps; 3236 int ret, sig; 3237 3238 p = td->td_proc; 3239 PROC_LOCK_ASSERT(p, MA_OWNED); 3240 3241 if ((td->td_flags & TDF_NEEDSIGCHK) == 0) 3242 return (0); 3243 3244 ps = p->p_sigacts; 3245 mtx_lock(&ps->ps_mtx); 3246 sig = cursig(td); 3247 if (sig == -1) { 3248 mtx_unlock(&ps->ps_mtx); 3249 KASSERT((td->td_flags & TDF_SBDRY) != 0, ("lost TDF_SBDRY")); 3250 KASSERT(TD_SBDRY_INTR(td), 3251 ("lost TDF_SERESTART of TDF_SEINTR")); 3252 KASSERT((td->td_flags & (TDF_SEINTR | TDF_SERESTART)) != 3253 (TDF_SEINTR | TDF_SERESTART), 3254 ("both TDF_SEINTR and TDF_SERESTART")); 3255 ret = TD_SBDRY_ERRNO(td); 3256 } else if (sig != 0) { 3257 ret = SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : ERESTART; 3258 mtx_unlock(&ps->ps_mtx); 3259 } else { 3260 mtx_unlock(&ps->ps_mtx); 3261 ret = 0; 3262 } 3263 3264 /* 3265 * Do not go into sleep if this thread was the ptrace(2) 3266 * attach leader. cursig() consumed SIGSTOP from PT_ATTACH, 3267 * but we usually act on the signal by interrupting sleep, and 3268 * should do that here as well. 3269 */ 3270 if ((td->td_dbgflags & TDB_FSTP) != 0) { 3271 if (ret == 0) 3272 ret = EINTR; 3273 td->td_dbgflags &= ~TDB_FSTP; 3274 } 3275 3276 return (ret); 3277 } 3278 3279 int 3280 sig_intr(void) 3281 { 3282 struct thread *td; 3283 struct proc *p; 3284 int ret; 3285 3286 td = curthread; 3287 if ((td->td_flags & (TDF_NEEDSIGCHK | TDF_NEEDSUSPCHK)) == 0) 3288 return (0); 3289 3290 p = td->td_proc; 3291 3292 PROC_LOCK(p); 3293 ret = sig_ast_checksusp(td); 3294 if (ret == 0) 3295 ret = sig_ast_needsigchk(td); 3296 PROC_UNLOCK(p); 3297 return (ret); 3298 } 3299 3300 void 3301 proc_wkilled(struct proc *p) 3302 { 3303 3304 PROC_LOCK_ASSERT(p, MA_OWNED); 3305 if ((p->p_flag & P_WKILLED) == 0) { 3306 p->p_flag |= P_WKILLED; 3307 /* 3308 * Notify swapper that there is a process to swap in. 3309 * The notification is racy, at worst it would take 10 3310 * seconds for the swapper process to notice. 3311 */ 3312 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3313 wakeup(&proc0); 3314 } 3315 } 3316 3317 /* 3318 * Kill the current process for stated reason. 3319 */ 3320 void 3321 killproc(struct proc *p, const char *why) 3322 { 3323 3324 PROC_LOCK_ASSERT(p, MA_OWNED); 3325 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3326 p->p_comm); 3327 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3328 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3329 p->p_ucred->cr_uid, why); 3330 proc_wkilled(p); 3331 kern_psignal(p, SIGKILL); 3332 } 3333 3334 /* 3335 * Force the current process to exit with the specified signal, dumping core 3336 * if appropriate. We bypass the normal tests for masked and caught signals, 3337 * allowing unrecoverable failures to terminate the process without changing 3338 * signal state. Mark the accounting record with the signal termination. 3339 * If dumping core, save the signal number for the debugger. Calls exit and 3340 * does not return. 3341 */ 3342 void 3343 sigexit(struct thread *td, int sig) 3344 { 3345 struct proc *p = td->td_proc; 3346 3347 PROC_LOCK_ASSERT(p, MA_OWNED); 3348 p->p_acflag |= AXSIG; 3349 /* 3350 * We must be single-threading to generate a core dump. This 3351 * ensures that the registers in the core file are up-to-date. 3352 * Also, the ELF dump handler assumes that the thread list doesn't 3353 * change out from under it. 3354 * 3355 * XXX If another thread attempts to single-thread before us 3356 * (e.g. via fork()), we won't get a dump at all. 3357 */ 3358 if ((sigprop(sig) & SIGPROP_CORE) && 3359 thread_single(p, SINGLE_NO_EXIT) == 0) { 3360 p->p_sig = sig; 3361 /* 3362 * Log signals which would cause core dumps 3363 * (Log as LOG_INFO to appease those who don't want 3364 * these messages.) 3365 * XXX : Todo, as well as euid, write out ruid too 3366 * Note that coredump() drops proc lock. 3367 */ 3368 if (coredump(td) == 0) 3369 sig |= WCOREFLAG; 3370 if (kern_logsigexit) 3371 log(LOG_INFO, 3372 "pid %d (%s), jid %d, uid %d: exited on " 3373 "signal %d%s\n", p->p_pid, p->p_comm, 3374 p->p_ucred->cr_prison->pr_id, 3375 td->td_ucred->cr_uid, 3376 sig &~ WCOREFLAG, 3377 sig & WCOREFLAG ? " (core dumped)" : ""); 3378 } else 3379 PROC_UNLOCK(p); 3380 exit1(td, 0, sig); 3381 /* NOTREACHED */ 3382 } 3383 3384 /* 3385 * Send queued SIGCHLD to parent when child process's state 3386 * is changed. 3387 */ 3388 static void 3389 sigparent(struct proc *p, int reason, int status) 3390 { 3391 PROC_LOCK_ASSERT(p, MA_OWNED); 3392 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3393 3394 if (p->p_ksi != NULL) { 3395 p->p_ksi->ksi_signo = SIGCHLD; 3396 p->p_ksi->ksi_code = reason; 3397 p->p_ksi->ksi_status = status; 3398 p->p_ksi->ksi_pid = p->p_pid; 3399 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3400 if (KSI_ONQ(p->p_ksi)) 3401 return; 3402 } 3403 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3404 } 3405 3406 static void 3407 childproc_jobstate(struct proc *p, int reason, int sig) 3408 { 3409 struct sigacts *ps; 3410 3411 PROC_LOCK_ASSERT(p, MA_OWNED); 3412 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3413 3414 /* 3415 * Wake up parent sleeping in kern_wait(), also send 3416 * SIGCHLD to parent, but SIGCHLD does not guarantee 3417 * that parent will awake, because parent may masked 3418 * the signal. 3419 */ 3420 p->p_pptr->p_flag |= P_STATCHILD; 3421 wakeup(p->p_pptr); 3422 3423 ps = p->p_pptr->p_sigacts; 3424 mtx_lock(&ps->ps_mtx); 3425 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3426 mtx_unlock(&ps->ps_mtx); 3427 sigparent(p, reason, sig); 3428 } else 3429 mtx_unlock(&ps->ps_mtx); 3430 } 3431 3432 void 3433 childproc_stopped(struct proc *p, int reason) 3434 { 3435 3436 childproc_jobstate(p, reason, p->p_xsig); 3437 } 3438 3439 void 3440 childproc_continued(struct proc *p) 3441 { 3442 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3443 } 3444 3445 void 3446 childproc_exited(struct proc *p) 3447 { 3448 int reason, status; 3449 3450 if (WCOREDUMP(p->p_xsig)) { 3451 reason = CLD_DUMPED; 3452 status = WTERMSIG(p->p_xsig); 3453 } else if (WIFSIGNALED(p->p_xsig)) { 3454 reason = CLD_KILLED; 3455 status = WTERMSIG(p->p_xsig); 3456 } else { 3457 reason = CLD_EXITED; 3458 status = p->p_xexit; 3459 } 3460 /* 3461 * XXX avoid calling wakeup(p->p_pptr), the work is 3462 * done in exit1(). 3463 */ 3464 sigparent(p, reason, status); 3465 } 3466 3467 #define MAX_NUM_CORE_FILES 100000 3468 #ifndef NUM_CORE_FILES 3469 #define NUM_CORE_FILES 5 3470 #endif 3471 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3472 static int num_cores = NUM_CORE_FILES; 3473 3474 static int 3475 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3476 { 3477 int error; 3478 int new_val; 3479 3480 new_val = num_cores; 3481 error = sysctl_handle_int(oidp, &new_val, 0, req); 3482 if (error != 0 || req->newptr == NULL) 3483 return (error); 3484 if (new_val > MAX_NUM_CORE_FILES) 3485 new_val = MAX_NUM_CORE_FILES; 3486 if (new_val < 0) 3487 new_val = 0; 3488 num_cores = new_val; 3489 return (0); 3490 } 3491 SYSCTL_PROC(_debug, OID_AUTO, ncores, 3492 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3493 sysctl_debug_num_cores_check, "I", 3494 "Maximum number of generated process corefiles while using index format"); 3495 3496 #define GZIP_SUFFIX ".gz" 3497 #define ZSTD_SUFFIX ".zst" 3498 3499 int compress_user_cores = 0; 3500 3501 static int 3502 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3503 { 3504 int error, val; 3505 3506 val = compress_user_cores; 3507 error = sysctl_handle_int(oidp, &val, 0, req); 3508 if (error != 0 || req->newptr == NULL) 3509 return (error); 3510 if (val != 0 && !compressor_avail(val)) 3511 return (EINVAL); 3512 compress_user_cores = val; 3513 return (error); 3514 } 3515 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, 3516 CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3517 sysctl_compress_user_cores, "I", 3518 "Enable compression of user corefiles (" 3519 __XSTRING(COMPRESS_GZIP) " = gzip, " 3520 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3521 3522 int compress_user_cores_level = 6; 3523 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3524 &compress_user_cores_level, 0, 3525 "Corefile compression level"); 3526 3527 /* 3528 * Protect the access to corefilename[] by allproc_lock. 3529 */ 3530 #define corefilename_lock allproc_lock 3531 3532 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3533 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3534 3535 static int 3536 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3537 { 3538 int error; 3539 3540 sx_xlock(&corefilename_lock); 3541 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3542 req); 3543 sx_xunlock(&corefilename_lock); 3544 3545 return (error); 3546 } 3547 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3548 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3549 "Process corefile name format string"); 3550 3551 static void 3552 vnode_close_locked(struct thread *td, struct vnode *vp) 3553 { 3554 3555 VOP_UNLOCK(vp); 3556 vn_close(vp, FWRITE, td->td_ucred, td); 3557 } 3558 3559 /* 3560 * If the core format has a %I in it, then we need to check 3561 * for existing corefiles before defining a name. 3562 * To do this we iterate over 0..ncores to find a 3563 * non-existing core file name to use. If all core files are 3564 * already used we choose the oldest one. 3565 */ 3566 static int 3567 corefile_open_last(struct thread *td, char *name, int indexpos, 3568 int indexlen, int ncores, struct vnode **vpp) 3569 { 3570 struct vnode *oldvp, *nextvp, *vp; 3571 struct vattr vattr; 3572 struct nameidata nd; 3573 int error, i, flags, oflags, cmode; 3574 char ch; 3575 struct timespec lasttime; 3576 3577 nextvp = oldvp = NULL; 3578 cmode = S_IRUSR | S_IWUSR; 3579 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3580 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3581 3582 for (i = 0; i < ncores; i++) { 3583 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3584 3585 ch = name[indexpos + indexlen]; 3586 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3587 i); 3588 name[indexpos + indexlen] = ch; 3589 3590 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3591 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3592 NULL); 3593 if (error != 0) 3594 break; 3595 3596 vp = nd.ni_vp; 3597 NDFREE(&nd, NDF_ONLY_PNBUF); 3598 if ((flags & O_CREAT) == O_CREAT) { 3599 nextvp = vp; 3600 break; 3601 } 3602 3603 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3604 if (error != 0) { 3605 vnode_close_locked(td, vp); 3606 break; 3607 } 3608 3609 if (oldvp == NULL || 3610 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3611 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3612 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3613 if (oldvp != NULL) 3614 vn_close(oldvp, FWRITE, td->td_ucred, td); 3615 oldvp = vp; 3616 VOP_UNLOCK(oldvp); 3617 lasttime = vattr.va_mtime; 3618 } else { 3619 vnode_close_locked(td, vp); 3620 } 3621 } 3622 3623 if (oldvp != NULL) { 3624 if (nextvp == NULL) { 3625 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3626 error = EFAULT; 3627 vn_close(oldvp, FWRITE, td->td_ucred, td); 3628 } else { 3629 nextvp = oldvp; 3630 error = vn_lock(nextvp, LK_EXCLUSIVE); 3631 if (error != 0) { 3632 vn_close(nextvp, FWRITE, td->td_ucred, 3633 td); 3634 nextvp = NULL; 3635 } 3636 } 3637 } else { 3638 vn_close(oldvp, FWRITE, td->td_ucred, td); 3639 } 3640 } 3641 if (error != 0) { 3642 if (nextvp != NULL) 3643 vnode_close_locked(td, oldvp); 3644 } else { 3645 *vpp = nextvp; 3646 } 3647 3648 return (error); 3649 } 3650 3651 /* 3652 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3653 * Expand the name described in corefilename, using name, uid, and pid 3654 * and open/create core file. 3655 * corefilename is a printf-like string, with three format specifiers: 3656 * %N name of process ("name") 3657 * %P process id (pid) 3658 * %U user id (uid) 3659 * For example, "%N.core" is the default; they can be disabled completely 3660 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3661 * This is controlled by the sysctl variable kern.corefile (see above). 3662 */ 3663 static int 3664 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3665 int compress, int signum, struct vnode **vpp, char **namep) 3666 { 3667 struct sbuf sb; 3668 struct nameidata nd; 3669 const char *format; 3670 char *hostname, *name; 3671 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3672 3673 hostname = NULL; 3674 format = corefilename; 3675 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3676 indexlen = 0; 3677 indexpos = -1; 3678 ncores = num_cores; 3679 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3680 sx_slock(&corefilename_lock); 3681 for (i = 0; format[i] != '\0'; i++) { 3682 switch (format[i]) { 3683 case '%': /* Format character */ 3684 i++; 3685 switch (format[i]) { 3686 case '%': 3687 sbuf_putc(&sb, '%'); 3688 break; 3689 case 'H': /* hostname */ 3690 if (hostname == NULL) { 3691 hostname = malloc(MAXHOSTNAMELEN, 3692 M_TEMP, M_WAITOK); 3693 } 3694 getcredhostname(td->td_ucred, hostname, 3695 MAXHOSTNAMELEN); 3696 sbuf_printf(&sb, "%s", hostname); 3697 break; 3698 case 'I': /* autoincrementing index */ 3699 if (indexpos != -1) { 3700 sbuf_printf(&sb, "%%I"); 3701 break; 3702 } 3703 3704 indexpos = sbuf_len(&sb); 3705 sbuf_printf(&sb, "%u", ncores - 1); 3706 indexlen = sbuf_len(&sb) - indexpos; 3707 break; 3708 case 'N': /* process name */ 3709 sbuf_printf(&sb, "%s", comm); 3710 break; 3711 case 'P': /* process id */ 3712 sbuf_printf(&sb, "%u", pid); 3713 break; 3714 case 'S': /* signal number */ 3715 sbuf_printf(&sb, "%i", signum); 3716 break; 3717 case 'U': /* user id */ 3718 sbuf_printf(&sb, "%u", uid); 3719 break; 3720 default: 3721 log(LOG_ERR, 3722 "Unknown format character %c in " 3723 "corename `%s'\n", format[i], format); 3724 break; 3725 } 3726 break; 3727 default: 3728 sbuf_putc(&sb, format[i]); 3729 break; 3730 } 3731 } 3732 sx_sunlock(&corefilename_lock); 3733 free(hostname, M_TEMP); 3734 if (compress == COMPRESS_GZIP) 3735 sbuf_printf(&sb, GZIP_SUFFIX); 3736 else if (compress == COMPRESS_ZSTD) 3737 sbuf_printf(&sb, ZSTD_SUFFIX); 3738 if (sbuf_error(&sb) != 0) { 3739 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3740 "long\n", (long)pid, comm, (u_long)uid); 3741 sbuf_delete(&sb); 3742 free(name, M_TEMP); 3743 return (ENOMEM); 3744 } 3745 sbuf_finish(&sb); 3746 sbuf_delete(&sb); 3747 3748 if (indexpos != -1) { 3749 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3750 vpp); 3751 if (error != 0) { 3752 log(LOG_ERR, 3753 "pid %d (%s), uid (%u): Path `%s' failed " 3754 "on initial open test, error = %d\n", 3755 pid, comm, uid, name, error); 3756 } 3757 } else { 3758 cmode = S_IRUSR | S_IWUSR; 3759 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3760 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3761 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3762 if ((td->td_proc->p_flag & P_SUGID) != 0) 3763 flags |= O_EXCL; 3764 3765 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3766 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3767 NULL); 3768 if (error == 0) { 3769 *vpp = nd.ni_vp; 3770 NDFREE(&nd, NDF_ONLY_PNBUF); 3771 } 3772 } 3773 3774 if (error != 0) { 3775 #ifdef AUDIT 3776 audit_proc_coredump(td, name, error); 3777 #endif 3778 free(name, M_TEMP); 3779 return (error); 3780 } 3781 *namep = name; 3782 return (0); 3783 } 3784 3785 /* 3786 * Dump a process' core. The main routine does some 3787 * policy checking, and creates the name of the coredump; 3788 * then it passes on a vnode and a size limit to the process-specific 3789 * coredump routine if there is one; if there _is not_ one, it returns 3790 * ENOSYS; otherwise it returns the error from the process-specific routine. 3791 */ 3792 3793 static int 3794 coredump(struct thread *td) 3795 { 3796 struct proc *p = td->td_proc; 3797 struct ucred *cred = td->td_ucred; 3798 struct vnode *vp; 3799 struct flock lf; 3800 struct vattr vattr; 3801 size_t fullpathsize; 3802 int error, error1, locked; 3803 char *name; /* name of corefile */ 3804 void *rl_cookie; 3805 off_t limit; 3806 char *fullpath, *freepath = NULL; 3807 struct sbuf *sb; 3808 3809 PROC_LOCK_ASSERT(p, MA_OWNED); 3810 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3811 3812 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3813 (p->p_flag2 & P2_NOTRACE) != 0) { 3814 PROC_UNLOCK(p); 3815 return (EFAULT); 3816 } 3817 3818 /* 3819 * Note that the bulk of limit checking is done after 3820 * the corefile is created. The exception is if the limit 3821 * for corefiles is 0, in which case we don't bother 3822 * creating the corefile at all. This layout means that 3823 * a corefile is truncated instead of not being created, 3824 * if it is larger than the limit. 3825 */ 3826 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3827 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3828 PROC_UNLOCK(p); 3829 return (EFBIG); 3830 } 3831 PROC_UNLOCK(p); 3832 3833 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3834 compress_user_cores, p->p_sig, &vp, &name); 3835 if (error != 0) 3836 return (error); 3837 3838 /* 3839 * Don't dump to non-regular files or files with links. 3840 * Do not dump into system files. Effective user must own the corefile. 3841 */ 3842 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3843 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 3844 vattr.va_uid != cred->cr_uid) { 3845 VOP_UNLOCK(vp); 3846 error = EFAULT; 3847 goto out; 3848 } 3849 3850 VOP_UNLOCK(vp); 3851 3852 /* Postpone other writers, including core dumps of other processes. */ 3853 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3854 3855 lf.l_whence = SEEK_SET; 3856 lf.l_start = 0; 3857 lf.l_len = 0; 3858 lf.l_type = F_WRLCK; 3859 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3860 3861 VATTR_NULL(&vattr); 3862 vattr.va_size = 0; 3863 if (set_core_nodump_flag) 3864 vattr.va_flags = UF_NODUMP; 3865 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3866 VOP_SETATTR(vp, &vattr, cred); 3867 VOP_UNLOCK(vp); 3868 PROC_LOCK(p); 3869 p->p_acflag |= ACORE; 3870 PROC_UNLOCK(p); 3871 3872 if (p->p_sysent->sv_coredump != NULL) { 3873 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3874 } else { 3875 error = ENOSYS; 3876 } 3877 3878 if (locked) { 3879 lf.l_type = F_UNLCK; 3880 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3881 } 3882 vn_rangelock_unlock(vp, rl_cookie); 3883 3884 /* 3885 * Notify the userland helper that a process triggered a core dump. 3886 * This allows the helper to run an automated debugging session. 3887 */ 3888 if (error != 0 || coredump_devctl == 0) 3889 goto out; 3890 sb = sbuf_new_auto(); 3891 if (vn_fullpath_global(p->p_textvp, &fullpath, &freepath) != 0) 3892 goto out2; 3893 sbuf_printf(sb, "comm=\""); 3894 devctl_safe_quote_sb(sb, fullpath); 3895 free(freepath, M_TEMP); 3896 sbuf_printf(sb, "\" core=\""); 3897 3898 /* 3899 * We can't lookup core file vp directly. When we're replacing a core, and 3900 * other random times, we flush the name cache, so it will fail. Instead, 3901 * if the path of the core is relative, add the current dir in front if it. 3902 */ 3903 if (name[0] != '/') { 3904 fullpathsize = MAXPATHLEN; 3905 freepath = malloc(fullpathsize, M_TEMP, M_WAITOK); 3906 if (vn_getcwd(freepath, &fullpath, &fullpathsize) != 0) { 3907 free(freepath, M_TEMP); 3908 goto out2; 3909 } 3910 devctl_safe_quote_sb(sb, fullpath); 3911 free(freepath, M_TEMP); 3912 sbuf_putc(sb, '/'); 3913 } 3914 devctl_safe_quote_sb(sb, name); 3915 sbuf_printf(sb, "\""); 3916 if (sbuf_finish(sb) == 0) 3917 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 3918 out2: 3919 sbuf_delete(sb); 3920 out: 3921 error1 = vn_close(vp, FWRITE, cred, td); 3922 if (error == 0) 3923 error = error1; 3924 #ifdef AUDIT 3925 audit_proc_coredump(td, name, error); 3926 #endif 3927 free(name, M_TEMP); 3928 return (error); 3929 } 3930 3931 /* 3932 * Nonexistent system call-- signal process (may want to handle it). Flag 3933 * error in case process won't see signal immediately (blocked or ignored). 3934 */ 3935 #ifndef _SYS_SYSPROTO_H_ 3936 struct nosys_args { 3937 int dummy; 3938 }; 3939 #endif 3940 /* ARGSUSED */ 3941 int 3942 nosys(struct thread *td, struct nosys_args *args) 3943 { 3944 struct proc *p; 3945 3946 p = td->td_proc; 3947 3948 PROC_LOCK(p); 3949 tdsignal(td, SIGSYS); 3950 PROC_UNLOCK(p); 3951 if (kern_lognosys == 1 || kern_lognosys == 3) { 3952 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3953 td->td_sa.code); 3954 } 3955 if (kern_lognosys == 2 || kern_lognosys == 3 || 3956 (p->p_pid == 1 && (kern_lognosys & 3) == 0)) { 3957 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3958 td->td_sa.code); 3959 } 3960 return (ENOSYS); 3961 } 3962 3963 /* 3964 * Send a SIGIO or SIGURG signal to a process or process group using stored 3965 * credentials rather than those of the current process. 3966 */ 3967 void 3968 pgsigio(struct sigio **sigiop, int sig, int checkctty) 3969 { 3970 ksiginfo_t ksi; 3971 struct sigio *sigio; 3972 3973 ksiginfo_init(&ksi); 3974 ksi.ksi_signo = sig; 3975 ksi.ksi_code = SI_KERNEL; 3976 3977 SIGIO_LOCK(); 3978 sigio = *sigiop; 3979 if (sigio == NULL) { 3980 SIGIO_UNLOCK(); 3981 return; 3982 } 3983 if (sigio->sio_pgid > 0) { 3984 PROC_LOCK(sigio->sio_proc); 3985 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3986 kern_psignal(sigio->sio_proc, sig); 3987 PROC_UNLOCK(sigio->sio_proc); 3988 } else if (sigio->sio_pgid < 0) { 3989 struct proc *p; 3990 3991 PGRP_LOCK(sigio->sio_pgrp); 3992 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3993 PROC_LOCK(p); 3994 if (p->p_state == PRS_NORMAL && 3995 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3996 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3997 kern_psignal(p, sig); 3998 PROC_UNLOCK(p); 3999 } 4000 PGRP_UNLOCK(sigio->sio_pgrp); 4001 } 4002 SIGIO_UNLOCK(); 4003 } 4004 4005 static int 4006 filt_sigattach(struct knote *kn) 4007 { 4008 struct proc *p = curproc; 4009 4010 kn->kn_ptr.p_proc = p; 4011 kn->kn_flags |= EV_CLEAR; /* automatically set */ 4012 4013 knlist_add(p->p_klist, kn, 0); 4014 4015 return (0); 4016 } 4017 4018 static void 4019 filt_sigdetach(struct knote *kn) 4020 { 4021 struct proc *p = kn->kn_ptr.p_proc; 4022 4023 knlist_remove(p->p_klist, kn, 0); 4024 } 4025 4026 /* 4027 * signal knotes are shared with proc knotes, so we apply a mask to 4028 * the hint in order to differentiate them from process hints. This 4029 * could be avoided by using a signal-specific knote list, but probably 4030 * isn't worth the trouble. 4031 */ 4032 static int 4033 filt_signal(struct knote *kn, long hint) 4034 { 4035 4036 if (hint & NOTE_SIGNAL) { 4037 hint &= ~NOTE_SIGNAL; 4038 4039 if (kn->kn_id == hint) 4040 kn->kn_data++; 4041 } 4042 return (kn->kn_data != 0); 4043 } 4044 4045 struct sigacts * 4046 sigacts_alloc(void) 4047 { 4048 struct sigacts *ps; 4049 4050 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 4051 refcount_init(&ps->ps_refcnt, 1); 4052 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 4053 return (ps); 4054 } 4055 4056 void 4057 sigacts_free(struct sigacts *ps) 4058 { 4059 4060 if (refcount_release(&ps->ps_refcnt) == 0) 4061 return; 4062 mtx_destroy(&ps->ps_mtx); 4063 free(ps, M_SUBPROC); 4064 } 4065 4066 struct sigacts * 4067 sigacts_hold(struct sigacts *ps) 4068 { 4069 4070 refcount_acquire(&ps->ps_refcnt); 4071 return (ps); 4072 } 4073 4074 void 4075 sigacts_copy(struct sigacts *dest, struct sigacts *src) 4076 { 4077 4078 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 4079 mtx_lock(&src->ps_mtx); 4080 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 4081 mtx_unlock(&src->ps_mtx); 4082 } 4083 4084 int 4085 sigacts_shared(struct sigacts *ps) 4086 { 4087 4088 return (ps->ps_refcnt > 1); 4089 } 4090 4091 void 4092 sig_drop_caught(struct proc *p) 4093 { 4094 int sig; 4095 struct sigacts *ps; 4096 4097 ps = p->p_sigacts; 4098 PROC_LOCK_ASSERT(p, MA_OWNED); 4099 mtx_assert(&ps->ps_mtx, MA_OWNED); 4100 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 4101 sig = sig_ffs(&ps->ps_sigcatch); 4102 sigdflt(ps, sig); 4103 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 4104 sigqueue_delete_proc(p, sig); 4105 } 4106 } 4107 4108 static void 4109 sigfastblock_failed(struct thread *td, bool sendsig, bool write) 4110 { 4111 ksiginfo_t ksi; 4112 4113 /* 4114 * Prevent further fetches and SIGSEGVs, allowing thread to 4115 * issue syscalls despite corruption. 4116 */ 4117 sigfastblock_clear(td); 4118 4119 if (!sendsig) 4120 return; 4121 ksiginfo_init_trap(&ksi); 4122 ksi.ksi_signo = SIGSEGV; 4123 ksi.ksi_code = write ? SEGV_ACCERR : SEGV_MAPERR; 4124 ksi.ksi_addr = td->td_sigblock_ptr; 4125 trapsignal(td, &ksi); 4126 } 4127 4128 static bool 4129 sigfastblock_fetch_sig(struct thread *td, bool sendsig, uint32_t *valp) 4130 { 4131 uint32_t res; 4132 4133 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4134 return (true); 4135 if (fueword32((void *)td->td_sigblock_ptr, &res) == -1) { 4136 sigfastblock_failed(td, sendsig, false); 4137 return (false); 4138 } 4139 *valp = res; 4140 td->td_sigblock_val = res & ~SIGFASTBLOCK_FLAGS; 4141 return (true); 4142 } 4143 4144 static void 4145 sigfastblock_resched(struct thread *td, bool resched) 4146 { 4147 struct proc *p; 4148 4149 if (resched) { 4150 p = td->td_proc; 4151 PROC_LOCK(p); 4152 reschedule_signals(p, td->td_sigmask, 0); 4153 PROC_UNLOCK(p); 4154 } 4155 thread_lock(td); 4156 td->td_flags |= TDF_ASTPENDING | TDF_NEEDSIGCHK; 4157 thread_unlock(td); 4158 } 4159 4160 int 4161 sys_sigfastblock(struct thread *td, struct sigfastblock_args *uap) 4162 { 4163 struct proc *p; 4164 int error, res; 4165 uint32_t oldval; 4166 4167 error = 0; 4168 p = td->td_proc; 4169 switch (uap->cmd) { 4170 case SIGFASTBLOCK_SETPTR: 4171 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 4172 error = EBUSY; 4173 break; 4174 } 4175 if (((uintptr_t)(uap->ptr) & (sizeof(uint32_t) - 1)) != 0) { 4176 error = EINVAL; 4177 break; 4178 } 4179 td->td_pflags |= TDP_SIGFASTBLOCK; 4180 td->td_sigblock_ptr = uap->ptr; 4181 break; 4182 4183 case SIGFASTBLOCK_UNBLOCK: 4184 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4185 error = EINVAL; 4186 break; 4187 } 4188 4189 for (;;) { 4190 res = casueword32(td->td_sigblock_ptr, 4191 SIGFASTBLOCK_PEND, &oldval, 0); 4192 if (res == -1) { 4193 error = EFAULT; 4194 sigfastblock_failed(td, false, true); 4195 break; 4196 } 4197 if (res == 0) 4198 break; 4199 MPASS(res == 1); 4200 if (oldval != SIGFASTBLOCK_PEND) { 4201 error = EBUSY; 4202 break; 4203 } 4204 error = thread_check_susp(td, false); 4205 if (error != 0) 4206 break; 4207 } 4208 if (error != 0) 4209 break; 4210 4211 /* 4212 * td_sigblock_val is cleared there, but not on a 4213 * syscall exit. The end effect is that a single 4214 * interruptible sleep, while user sigblock word is 4215 * set, might return EINTR or ERESTART to usermode 4216 * without delivering signal. All further sleeps, 4217 * until userspace clears the word and does 4218 * sigfastblock(UNBLOCK), observe current word and no 4219 * longer get interrupted. It is slight 4220 * non-conformance, with alternative to have read the 4221 * sigblock word on each syscall entry. 4222 */ 4223 td->td_sigblock_val = 0; 4224 4225 /* 4226 * Rely on normal ast mechanism to deliver pending 4227 * signals to current thread. But notify others about 4228 * fake unblock. 4229 */ 4230 sigfastblock_resched(td, error == 0 && p->p_numthreads != 1); 4231 4232 break; 4233 4234 case SIGFASTBLOCK_UNSETPTR: 4235 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4236 error = EINVAL; 4237 break; 4238 } 4239 if (!sigfastblock_fetch_sig(td, false, &oldval)) { 4240 error = EFAULT; 4241 break; 4242 } 4243 if (oldval != 0 && oldval != SIGFASTBLOCK_PEND) { 4244 error = EBUSY; 4245 break; 4246 } 4247 sigfastblock_clear(td); 4248 break; 4249 4250 default: 4251 error = EINVAL; 4252 break; 4253 } 4254 return (error); 4255 } 4256 4257 void 4258 sigfastblock_clear(struct thread *td) 4259 { 4260 bool resched; 4261 4262 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4263 return; 4264 td->td_sigblock_val = 0; 4265 resched = (td->td_pflags & TDP_SIGFASTPENDING) != 0 || 4266 SIGPENDING(td); 4267 td->td_pflags &= ~(TDP_SIGFASTBLOCK | TDP_SIGFASTPENDING); 4268 sigfastblock_resched(td, resched); 4269 } 4270 4271 void 4272 sigfastblock_fetch(struct thread *td) 4273 { 4274 uint32_t val; 4275 4276 (void)sigfastblock_fetch_sig(td, true, &val); 4277 } 4278 4279 static void 4280 sigfastblock_setpend1(struct thread *td) 4281 { 4282 int res; 4283 uint32_t oldval; 4284 4285 if ((td->td_pflags & TDP_SIGFASTPENDING) == 0) 4286 return; 4287 res = fueword32((void *)td->td_sigblock_ptr, &oldval); 4288 if (res == -1) { 4289 sigfastblock_failed(td, true, false); 4290 return; 4291 } 4292 for (;;) { 4293 res = casueword32(td->td_sigblock_ptr, oldval, &oldval, 4294 oldval | SIGFASTBLOCK_PEND); 4295 if (res == -1) { 4296 sigfastblock_failed(td, true, true); 4297 return; 4298 } 4299 if (res == 0) { 4300 td->td_sigblock_val = oldval & ~SIGFASTBLOCK_FLAGS; 4301 td->td_pflags &= ~TDP_SIGFASTPENDING; 4302 break; 4303 } 4304 MPASS(res == 1); 4305 if (thread_check_susp(td, false) != 0) 4306 break; 4307 } 4308 } 4309 4310 void 4311 sigfastblock_setpend(struct thread *td, bool resched) 4312 { 4313 struct proc *p; 4314 4315 sigfastblock_setpend1(td); 4316 if (resched) { 4317 p = td->td_proc; 4318 PROC_LOCK(p); 4319 reschedule_signals(p, fastblock_mask, SIGPROCMASK_FASTBLK); 4320 PROC_UNLOCK(p); 4321 } 4322 } 4323