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 sigset_t osigignore; 991 struct sigacts *ps; 992 int sig; 993 struct thread *td; 994 995 /* 996 * Reset caught signals. Held signals remain held 997 * through td_sigmask (unless they were caught, 998 * and are now ignored by default). 999 */ 1000 PROC_LOCK_ASSERT(p, MA_OWNED); 1001 ps = p->p_sigacts; 1002 mtx_lock(&ps->ps_mtx); 1003 sig_drop_caught(p); 1004 1005 /* 1006 * As CloudABI processes cannot modify signal handlers, fully 1007 * reset all signals to their default behavior. Do ignore 1008 * SIGPIPE, as it would otherwise be impossible to recover from 1009 * writes to broken pipes and sockets. 1010 */ 1011 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 1012 osigignore = ps->ps_sigignore; 1013 while (SIGNOTEMPTY(osigignore)) { 1014 sig = sig_ffs(&osigignore); 1015 SIGDELSET(osigignore, sig); 1016 if (sig != SIGPIPE) 1017 sigdflt(ps, sig); 1018 } 1019 SIGADDSET(ps->ps_sigignore, SIGPIPE); 1020 } 1021 1022 /* 1023 * Reset stack state to the user stack. 1024 * Clear set of signals caught on the signal stack. 1025 */ 1026 td = curthread; 1027 MPASS(td->td_proc == p); 1028 td->td_sigstk.ss_flags = SS_DISABLE; 1029 td->td_sigstk.ss_size = 0; 1030 td->td_sigstk.ss_sp = 0; 1031 td->td_pflags &= ~TDP_ALTSTACK; 1032 /* 1033 * Reset no zombies if child dies flag as Solaris does. 1034 */ 1035 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1036 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1037 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1038 mtx_unlock(&ps->ps_mtx); 1039 } 1040 1041 /* 1042 * kern_sigprocmask() 1043 * 1044 * Manipulate signal mask. 1045 */ 1046 int 1047 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1048 int flags) 1049 { 1050 sigset_t new_block, oset1; 1051 struct proc *p; 1052 int error; 1053 1054 p = td->td_proc; 1055 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1056 PROC_LOCK_ASSERT(p, MA_OWNED); 1057 else 1058 PROC_LOCK(p); 1059 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1060 ? MA_OWNED : MA_NOTOWNED); 1061 if (oset != NULL) 1062 *oset = td->td_sigmask; 1063 1064 error = 0; 1065 if (set != NULL) { 1066 switch (how) { 1067 case SIG_BLOCK: 1068 SIG_CANTMASK(*set); 1069 oset1 = td->td_sigmask; 1070 SIGSETOR(td->td_sigmask, *set); 1071 new_block = td->td_sigmask; 1072 SIGSETNAND(new_block, oset1); 1073 break; 1074 case SIG_UNBLOCK: 1075 SIGSETNAND(td->td_sigmask, *set); 1076 signotify(td); 1077 goto out; 1078 case SIG_SETMASK: 1079 SIG_CANTMASK(*set); 1080 oset1 = td->td_sigmask; 1081 if (flags & SIGPROCMASK_OLD) 1082 SIGSETLO(td->td_sigmask, *set); 1083 else 1084 td->td_sigmask = *set; 1085 new_block = td->td_sigmask; 1086 SIGSETNAND(new_block, oset1); 1087 signotify(td); 1088 break; 1089 default: 1090 error = EINVAL; 1091 goto out; 1092 } 1093 1094 /* 1095 * The new_block set contains signals that were not previously 1096 * blocked, but are blocked now. 1097 * 1098 * In case we block any signal that was not previously blocked 1099 * for td, and process has the signal pending, try to schedule 1100 * signal delivery to some thread that does not block the 1101 * signal, possibly waking it up. 1102 */ 1103 if (p->p_numthreads != 1) 1104 reschedule_signals(p, new_block, flags); 1105 } 1106 1107 out: 1108 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1109 PROC_UNLOCK(p); 1110 return (error); 1111 } 1112 1113 #ifndef _SYS_SYSPROTO_H_ 1114 struct sigprocmask_args { 1115 int how; 1116 const sigset_t *set; 1117 sigset_t *oset; 1118 }; 1119 #endif 1120 int 1121 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1122 { 1123 sigset_t set, oset; 1124 sigset_t *setp, *osetp; 1125 int error; 1126 1127 setp = (uap->set != NULL) ? &set : NULL; 1128 osetp = (uap->oset != NULL) ? &oset : NULL; 1129 if (setp) { 1130 error = copyin(uap->set, setp, sizeof(set)); 1131 if (error) 1132 return (error); 1133 } 1134 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1135 if (osetp && !error) { 1136 error = copyout(osetp, uap->oset, sizeof(oset)); 1137 } 1138 return (error); 1139 } 1140 1141 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1142 #ifndef _SYS_SYSPROTO_H_ 1143 struct osigprocmask_args { 1144 int how; 1145 osigset_t mask; 1146 }; 1147 #endif 1148 int 1149 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1150 { 1151 sigset_t set, oset; 1152 int error; 1153 1154 OSIG2SIG(uap->mask, set); 1155 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1156 SIG2OSIG(oset, td->td_retval[0]); 1157 return (error); 1158 } 1159 #endif /* COMPAT_43 */ 1160 1161 int 1162 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1163 { 1164 ksiginfo_t ksi; 1165 sigset_t set; 1166 int error; 1167 1168 error = copyin(uap->set, &set, sizeof(set)); 1169 if (error) { 1170 td->td_retval[0] = error; 1171 return (0); 1172 } 1173 1174 error = kern_sigtimedwait(td, set, &ksi, NULL); 1175 if (error) { 1176 /* 1177 * sigwait() function shall not return EINTR, but 1178 * the syscall does. Non-ancient libc provides the 1179 * wrapper which hides EINTR. Otherwise, EINTR return 1180 * is used by libthr to handle required cancellation 1181 * point in the sigwait(). 1182 */ 1183 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1184 return (ERESTART); 1185 td->td_retval[0] = error; 1186 return (0); 1187 } 1188 1189 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1190 td->td_retval[0] = error; 1191 return (0); 1192 } 1193 1194 int 1195 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1196 { 1197 struct timespec ts; 1198 struct timespec *timeout; 1199 sigset_t set; 1200 ksiginfo_t ksi; 1201 int error; 1202 1203 if (uap->timeout) { 1204 error = copyin(uap->timeout, &ts, sizeof(ts)); 1205 if (error) 1206 return (error); 1207 1208 timeout = &ts; 1209 } else 1210 timeout = NULL; 1211 1212 error = copyin(uap->set, &set, sizeof(set)); 1213 if (error) 1214 return (error); 1215 1216 error = kern_sigtimedwait(td, set, &ksi, timeout); 1217 if (error) 1218 return (error); 1219 1220 if (uap->info) 1221 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1222 1223 if (error == 0) 1224 td->td_retval[0] = ksi.ksi_signo; 1225 return (error); 1226 } 1227 1228 int 1229 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1230 { 1231 ksiginfo_t ksi; 1232 sigset_t set; 1233 int error; 1234 1235 error = copyin(uap->set, &set, sizeof(set)); 1236 if (error) 1237 return (error); 1238 1239 error = kern_sigtimedwait(td, set, &ksi, NULL); 1240 if (error) 1241 return (error); 1242 1243 if (uap->info) 1244 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1245 1246 if (error == 0) 1247 td->td_retval[0] = ksi.ksi_signo; 1248 return (error); 1249 } 1250 1251 static void 1252 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1253 { 1254 struct thread *thr; 1255 1256 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1257 if (thr == td) 1258 thr->td_si = *si; 1259 else 1260 thr->td_si.si_signo = 0; 1261 } 1262 } 1263 1264 int 1265 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1266 struct timespec *timeout) 1267 { 1268 struct sigacts *ps; 1269 sigset_t saved_mask, new_block; 1270 struct proc *p; 1271 int error, sig, timo, timevalid = 0; 1272 struct timespec rts, ets, ts; 1273 struct timeval tv; 1274 bool traced; 1275 1276 p = td->td_proc; 1277 error = 0; 1278 ets.tv_sec = 0; 1279 ets.tv_nsec = 0; 1280 traced = false; 1281 1282 /* Ensure the sigfastblock value is up to date. */ 1283 sigfastblock_fetch(td); 1284 1285 if (timeout != NULL) { 1286 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1287 timevalid = 1; 1288 getnanouptime(&rts); 1289 timespecadd(&rts, timeout, &ets); 1290 } 1291 } 1292 ksiginfo_init(ksi); 1293 /* Some signals can not be waited for. */ 1294 SIG_CANTMASK(waitset); 1295 ps = p->p_sigacts; 1296 PROC_LOCK(p); 1297 saved_mask = td->td_sigmask; 1298 SIGSETNAND(td->td_sigmask, waitset); 1299 if ((p->p_sysent->sv_flags & SV_SIG_DISCIGN) != 0 || 1300 !kern_sig_discard_ign) 1301 td->td_pflags2 |= TDP2_SIGWAIT; 1302 for (;;) { 1303 mtx_lock(&ps->ps_mtx); 1304 sig = cursig(td); 1305 mtx_unlock(&ps->ps_mtx); 1306 KASSERT(sig >= 0, ("sig %d", sig)); 1307 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1308 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1309 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1310 error = 0; 1311 break; 1312 } 1313 } 1314 1315 if (error != 0) 1316 break; 1317 1318 /* 1319 * POSIX says this must be checked after looking for pending 1320 * signals. 1321 */ 1322 if (timeout != NULL) { 1323 if (!timevalid) { 1324 error = EINVAL; 1325 break; 1326 } 1327 getnanouptime(&rts); 1328 if (timespeccmp(&rts, &ets, >=)) { 1329 error = EAGAIN; 1330 break; 1331 } 1332 timespecsub(&ets, &rts, &ts); 1333 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1334 timo = tvtohz(&tv); 1335 } else { 1336 timo = 0; 1337 } 1338 1339 if (traced) { 1340 error = EINTR; 1341 break; 1342 } 1343 1344 error = msleep(&p->p_sigacts, &p->p_mtx, PPAUSE | PCATCH, 1345 "sigwait", timo); 1346 1347 /* The syscalls can not be restarted. */ 1348 if (error == ERESTART) 1349 error = EINTR; 1350 1351 /* We will calculate timeout by ourself. */ 1352 if (timeout != NULL && error == EAGAIN) 1353 error = 0; 1354 1355 /* 1356 * If PTRACE_SCE or PTRACE_SCX were set after 1357 * userspace entered the syscall, return spurious 1358 * EINTR after wait was done. Only do this as last 1359 * resort after rechecking for possible queued signals 1360 * and expired timeouts. 1361 */ 1362 if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0) 1363 traced = true; 1364 } 1365 td->td_pflags2 &= ~TDP2_SIGWAIT; 1366 1367 new_block = saved_mask; 1368 SIGSETNAND(new_block, td->td_sigmask); 1369 td->td_sigmask = saved_mask; 1370 /* 1371 * Fewer signals can be delivered to us, reschedule signal 1372 * notification. 1373 */ 1374 if (p->p_numthreads != 1) 1375 reschedule_signals(p, new_block, 0); 1376 1377 if (error == 0) { 1378 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1379 1380 if (ksi->ksi_code == SI_TIMER) 1381 itimer_accept(p, ksi->ksi_timerid, ksi); 1382 1383 #ifdef KTRACE 1384 if (KTRPOINT(td, KTR_PSIG)) { 1385 sig_t action; 1386 1387 mtx_lock(&ps->ps_mtx); 1388 action = ps->ps_sigact[_SIG_IDX(sig)]; 1389 mtx_unlock(&ps->ps_mtx); 1390 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1391 } 1392 #endif 1393 if (sig == SIGKILL) { 1394 proc_td_siginfo_capture(td, &ksi->ksi_info); 1395 sigexit(td, sig); 1396 } 1397 } 1398 PROC_UNLOCK(p); 1399 return (error); 1400 } 1401 1402 #ifndef _SYS_SYSPROTO_H_ 1403 struct sigpending_args { 1404 sigset_t *set; 1405 }; 1406 #endif 1407 int 1408 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1409 { 1410 struct proc *p = td->td_proc; 1411 sigset_t pending; 1412 1413 PROC_LOCK(p); 1414 pending = p->p_sigqueue.sq_signals; 1415 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1416 PROC_UNLOCK(p); 1417 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1418 } 1419 1420 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1421 #ifndef _SYS_SYSPROTO_H_ 1422 struct osigpending_args { 1423 int dummy; 1424 }; 1425 #endif 1426 int 1427 osigpending(struct thread *td, struct osigpending_args *uap) 1428 { 1429 struct proc *p = td->td_proc; 1430 sigset_t pending; 1431 1432 PROC_LOCK(p); 1433 pending = p->p_sigqueue.sq_signals; 1434 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1435 PROC_UNLOCK(p); 1436 SIG2OSIG(pending, td->td_retval[0]); 1437 return (0); 1438 } 1439 #endif /* COMPAT_43 */ 1440 1441 #if defined(COMPAT_43) 1442 /* 1443 * Generalized interface signal handler, 4.3-compatible. 1444 */ 1445 #ifndef _SYS_SYSPROTO_H_ 1446 struct osigvec_args { 1447 int signum; 1448 struct sigvec *nsv; 1449 struct sigvec *osv; 1450 }; 1451 #endif 1452 /* ARGSUSED */ 1453 int 1454 osigvec(struct thread *td, struct osigvec_args *uap) 1455 { 1456 struct sigvec vec; 1457 struct sigaction nsa, osa; 1458 struct sigaction *nsap, *osap; 1459 int error; 1460 1461 if (uap->signum <= 0 || uap->signum >= ONSIG) 1462 return (EINVAL); 1463 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1464 osap = (uap->osv != NULL) ? &osa : NULL; 1465 if (nsap) { 1466 error = copyin(uap->nsv, &vec, sizeof(vec)); 1467 if (error) 1468 return (error); 1469 nsap->sa_handler = vec.sv_handler; 1470 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1471 nsap->sa_flags = vec.sv_flags; 1472 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1473 } 1474 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1475 if (osap && !error) { 1476 vec.sv_handler = osap->sa_handler; 1477 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1478 vec.sv_flags = osap->sa_flags; 1479 vec.sv_flags &= ~SA_NOCLDWAIT; 1480 vec.sv_flags ^= SA_RESTART; 1481 error = copyout(&vec, uap->osv, sizeof(vec)); 1482 } 1483 return (error); 1484 } 1485 1486 #ifndef _SYS_SYSPROTO_H_ 1487 struct osigblock_args { 1488 int mask; 1489 }; 1490 #endif 1491 int 1492 osigblock(struct thread *td, struct osigblock_args *uap) 1493 { 1494 sigset_t set, oset; 1495 1496 OSIG2SIG(uap->mask, set); 1497 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1498 SIG2OSIG(oset, td->td_retval[0]); 1499 return (0); 1500 } 1501 1502 #ifndef _SYS_SYSPROTO_H_ 1503 struct osigsetmask_args { 1504 int mask; 1505 }; 1506 #endif 1507 int 1508 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1509 { 1510 sigset_t set, oset; 1511 1512 OSIG2SIG(uap->mask, set); 1513 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1514 SIG2OSIG(oset, td->td_retval[0]); 1515 return (0); 1516 } 1517 #endif /* COMPAT_43 */ 1518 1519 /* 1520 * Suspend calling thread until signal, providing mask to be set in the 1521 * meantime. 1522 */ 1523 #ifndef _SYS_SYSPROTO_H_ 1524 struct sigsuspend_args { 1525 const sigset_t *sigmask; 1526 }; 1527 #endif 1528 /* ARGSUSED */ 1529 int 1530 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1531 { 1532 sigset_t mask; 1533 int error; 1534 1535 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1536 if (error) 1537 return (error); 1538 return (kern_sigsuspend(td, mask)); 1539 } 1540 1541 int 1542 kern_sigsuspend(struct thread *td, sigset_t mask) 1543 { 1544 struct proc *p = td->td_proc; 1545 int has_sig, sig; 1546 1547 /* Ensure the sigfastblock value is up to date. */ 1548 sigfastblock_fetch(td); 1549 1550 /* 1551 * When returning from sigsuspend, we want 1552 * the old mask to be restored after the 1553 * signal handler has finished. Thus, we 1554 * save it here and mark the sigacts structure 1555 * to indicate this. 1556 */ 1557 PROC_LOCK(p); 1558 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1559 SIGPROCMASK_PROC_LOCKED); 1560 td->td_pflags |= TDP_OLDMASK; 1561 1562 /* 1563 * Process signals now. Otherwise, we can get spurious wakeup 1564 * due to signal entered process queue, but delivered to other 1565 * thread. But sigsuspend should return only on signal 1566 * delivery. 1567 */ 1568 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1569 for (has_sig = 0; !has_sig;) { 1570 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1571 0) == 0) 1572 /* void */; 1573 thread_suspend_check(0); 1574 mtx_lock(&p->p_sigacts->ps_mtx); 1575 while ((sig = cursig(td)) != 0) { 1576 KASSERT(sig >= 0, ("sig %d", sig)); 1577 has_sig += postsig(sig); 1578 } 1579 mtx_unlock(&p->p_sigacts->ps_mtx); 1580 1581 /* 1582 * If PTRACE_SCE or PTRACE_SCX were set after 1583 * userspace entered the syscall, return spurious 1584 * EINTR. 1585 */ 1586 if ((p->p_ptevents & PTRACE_SYSCALL) != 0) 1587 has_sig += 1; 1588 } 1589 PROC_UNLOCK(p); 1590 td->td_errno = EINTR; 1591 td->td_pflags |= TDP_NERRNO; 1592 return (EJUSTRETURN); 1593 } 1594 1595 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1596 /* 1597 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1598 * convention: libc stub passes mask, not pointer, to save a copyin. 1599 */ 1600 #ifndef _SYS_SYSPROTO_H_ 1601 struct osigsuspend_args { 1602 osigset_t mask; 1603 }; 1604 #endif 1605 /* ARGSUSED */ 1606 int 1607 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1608 { 1609 sigset_t mask; 1610 1611 OSIG2SIG(uap->mask, mask); 1612 return (kern_sigsuspend(td, mask)); 1613 } 1614 #endif /* COMPAT_43 */ 1615 1616 #if defined(COMPAT_43) 1617 #ifndef _SYS_SYSPROTO_H_ 1618 struct osigstack_args { 1619 struct sigstack *nss; 1620 struct sigstack *oss; 1621 }; 1622 #endif 1623 /* ARGSUSED */ 1624 int 1625 osigstack(struct thread *td, struct osigstack_args *uap) 1626 { 1627 struct sigstack nss, oss; 1628 int error = 0; 1629 1630 if (uap->nss != NULL) { 1631 error = copyin(uap->nss, &nss, sizeof(nss)); 1632 if (error) 1633 return (error); 1634 } 1635 oss.ss_sp = td->td_sigstk.ss_sp; 1636 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1637 if (uap->nss != NULL) { 1638 td->td_sigstk.ss_sp = nss.ss_sp; 1639 td->td_sigstk.ss_size = 0; 1640 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1641 td->td_pflags |= TDP_ALTSTACK; 1642 } 1643 if (uap->oss != NULL) 1644 error = copyout(&oss, uap->oss, sizeof(oss)); 1645 1646 return (error); 1647 } 1648 #endif /* COMPAT_43 */ 1649 1650 #ifndef _SYS_SYSPROTO_H_ 1651 struct sigaltstack_args { 1652 stack_t *ss; 1653 stack_t *oss; 1654 }; 1655 #endif 1656 /* ARGSUSED */ 1657 int 1658 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1659 { 1660 stack_t ss, oss; 1661 int error; 1662 1663 if (uap->ss != NULL) { 1664 error = copyin(uap->ss, &ss, sizeof(ss)); 1665 if (error) 1666 return (error); 1667 } 1668 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1669 (uap->oss != NULL) ? &oss : NULL); 1670 if (error) 1671 return (error); 1672 if (uap->oss != NULL) 1673 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1674 return (error); 1675 } 1676 1677 int 1678 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1679 { 1680 struct proc *p = td->td_proc; 1681 int oonstack; 1682 1683 oonstack = sigonstack(cpu_getstack(td)); 1684 1685 if (oss != NULL) { 1686 *oss = td->td_sigstk; 1687 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1688 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1689 } 1690 1691 if (ss != NULL) { 1692 if (oonstack) 1693 return (EPERM); 1694 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1695 return (EINVAL); 1696 if (!(ss->ss_flags & SS_DISABLE)) { 1697 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1698 return (ENOMEM); 1699 1700 td->td_sigstk = *ss; 1701 td->td_pflags |= TDP_ALTSTACK; 1702 } else { 1703 td->td_pflags &= ~TDP_ALTSTACK; 1704 } 1705 } 1706 return (0); 1707 } 1708 1709 struct killpg1_ctx { 1710 struct thread *td; 1711 ksiginfo_t *ksi; 1712 int sig; 1713 bool sent; 1714 bool found; 1715 int ret; 1716 }; 1717 1718 static void 1719 killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg) 1720 { 1721 int err; 1722 1723 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 || 1724 (notself && p == arg->td->td_proc) || p->p_state == PRS_NEW) 1725 return; 1726 PROC_LOCK(p); 1727 err = p_cansignal(arg->td, p, arg->sig); 1728 if (err == 0 && arg->sig != 0) 1729 pksignal(p, arg->sig, arg->ksi); 1730 PROC_UNLOCK(p); 1731 if (err != ESRCH) 1732 arg->found = true; 1733 if (err == 0) 1734 arg->sent = true; 1735 else if (arg->ret == 0 && err != ESRCH && err != EPERM) 1736 arg->ret = err; 1737 } 1738 1739 /* 1740 * Common code for kill process group/broadcast kill. 1741 * cp is calling process. 1742 */ 1743 static int 1744 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1745 { 1746 struct proc *p; 1747 struct pgrp *pgrp; 1748 struct killpg1_ctx arg; 1749 1750 arg.td = td; 1751 arg.ksi = ksi; 1752 arg.sig = sig; 1753 arg.sent = false; 1754 arg.found = false; 1755 arg.ret = 0; 1756 if (all) { 1757 /* 1758 * broadcast 1759 */ 1760 sx_slock(&allproc_lock); 1761 FOREACH_PROC_IN_SYSTEM(p) { 1762 killpg1_sendsig(p, true, &arg); 1763 } 1764 sx_sunlock(&allproc_lock); 1765 } else { 1766 sx_slock(&proctree_lock); 1767 if (pgid == 0) { 1768 /* 1769 * zero pgid means send to my process group. 1770 */ 1771 pgrp = td->td_proc->p_pgrp; 1772 PGRP_LOCK(pgrp); 1773 } else { 1774 pgrp = pgfind(pgid); 1775 if (pgrp == NULL) { 1776 sx_sunlock(&proctree_lock); 1777 return (ESRCH); 1778 } 1779 } 1780 sx_sunlock(&proctree_lock); 1781 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1782 killpg1_sendsig(p, false, &arg); 1783 } 1784 PGRP_UNLOCK(pgrp); 1785 } 1786 MPASS(arg.ret != 0 || arg.found || !arg.sent); 1787 if (arg.ret == 0 && !arg.sent) 1788 arg.ret = arg.found ? EPERM : ESRCH; 1789 return (arg.ret); 1790 } 1791 1792 #ifndef _SYS_SYSPROTO_H_ 1793 struct kill_args { 1794 int pid; 1795 int signum; 1796 }; 1797 #endif 1798 /* ARGSUSED */ 1799 int 1800 sys_kill(struct thread *td, struct kill_args *uap) 1801 { 1802 1803 return (kern_kill(td, uap->pid, uap->signum)); 1804 } 1805 1806 int 1807 kern_kill(struct thread *td, pid_t pid, int signum) 1808 { 1809 ksiginfo_t ksi; 1810 struct proc *p; 1811 int error; 1812 1813 /* 1814 * A process in capability mode can send signals only to himself. 1815 * The main rationale behind this is that abort(3) is implemented as 1816 * kill(getpid(), SIGABRT). 1817 */ 1818 if (IN_CAPABILITY_MODE(td) && pid != td->td_proc->p_pid) 1819 return (ECAPMODE); 1820 1821 AUDIT_ARG_SIGNUM(signum); 1822 AUDIT_ARG_PID(pid); 1823 if ((u_int)signum > _SIG_MAXSIG) 1824 return (EINVAL); 1825 1826 ksiginfo_init(&ksi); 1827 ksi.ksi_signo = signum; 1828 ksi.ksi_code = SI_USER; 1829 ksi.ksi_pid = td->td_proc->p_pid; 1830 ksi.ksi_uid = td->td_ucred->cr_ruid; 1831 1832 if (pid > 0) { 1833 /* kill single process */ 1834 if ((p = pfind_any(pid)) == NULL) 1835 return (ESRCH); 1836 AUDIT_ARG_PROCESS(p); 1837 error = p_cansignal(td, p, signum); 1838 if (error == 0 && signum) 1839 pksignal(p, signum, &ksi); 1840 PROC_UNLOCK(p); 1841 return (error); 1842 } 1843 switch (pid) { 1844 case -1: /* broadcast signal */ 1845 return (killpg1(td, signum, 0, 1, &ksi)); 1846 case 0: /* signal own process group */ 1847 return (killpg1(td, signum, 0, 0, &ksi)); 1848 default: /* negative explicit process group */ 1849 return (killpg1(td, signum, -pid, 0, &ksi)); 1850 } 1851 /* NOTREACHED */ 1852 } 1853 1854 int 1855 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1856 { 1857 struct proc *p; 1858 int error; 1859 1860 AUDIT_ARG_SIGNUM(uap->signum); 1861 AUDIT_ARG_FD(uap->fd); 1862 if ((u_int)uap->signum > _SIG_MAXSIG) 1863 return (EINVAL); 1864 1865 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1866 if (error) 1867 return (error); 1868 AUDIT_ARG_PROCESS(p); 1869 error = p_cansignal(td, p, uap->signum); 1870 if (error == 0 && uap->signum) 1871 kern_psignal(p, uap->signum); 1872 PROC_UNLOCK(p); 1873 return (error); 1874 } 1875 1876 #if defined(COMPAT_43) 1877 #ifndef _SYS_SYSPROTO_H_ 1878 struct okillpg_args { 1879 int pgid; 1880 int signum; 1881 }; 1882 #endif 1883 /* ARGSUSED */ 1884 int 1885 okillpg(struct thread *td, struct okillpg_args *uap) 1886 { 1887 ksiginfo_t ksi; 1888 1889 AUDIT_ARG_SIGNUM(uap->signum); 1890 AUDIT_ARG_PID(uap->pgid); 1891 if ((u_int)uap->signum > _SIG_MAXSIG) 1892 return (EINVAL); 1893 1894 ksiginfo_init(&ksi); 1895 ksi.ksi_signo = uap->signum; 1896 ksi.ksi_code = SI_USER; 1897 ksi.ksi_pid = td->td_proc->p_pid; 1898 ksi.ksi_uid = td->td_ucred->cr_ruid; 1899 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1900 } 1901 #endif /* COMPAT_43 */ 1902 1903 #ifndef _SYS_SYSPROTO_H_ 1904 struct sigqueue_args { 1905 pid_t pid; 1906 int signum; 1907 /* union sigval */ void *value; 1908 }; 1909 #endif 1910 int 1911 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1912 { 1913 union sigval sv; 1914 1915 sv.sival_ptr = uap->value; 1916 1917 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1918 } 1919 1920 int 1921 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1922 { 1923 ksiginfo_t ksi; 1924 struct proc *p; 1925 int error; 1926 1927 if ((u_int)signum > _SIG_MAXSIG) 1928 return (EINVAL); 1929 1930 /* 1931 * Specification says sigqueue can only send signal to 1932 * single process. 1933 */ 1934 if (pid <= 0) 1935 return (EINVAL); 1936 1937 if ((p = pfind_any(pid)) == NULL) 1938 return (ESRCH); 1939 error = p_cansignal(td, p, signum); 1940 if (error == 0 && signum != 0) { 1941 ksiginfo_init(&ksi); 1942 ksi.ksi_flags = KSI_SIGQ; 1943 ksi.ksi_signo = signum; 1944 ksi.ksi_code = SI_QUEUE; 1945 ksi.ksi_pid = td->td_proc->p_pid; 1946 ksi.ksi_uid = td->td_ucred->cr_ruid; 1947 ksi.ksi_value = *value; 1948 error = pksignal(p, ksi.ksi_signo, &ksi); 1949 } 1950 PROC_UNLOCK(p); 1951 return (error); 1952 } 1953 1954 /* 1955 * Send a signal to a process group. 1956 */ 1957 void 1958 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1959 { 1960 struct pgrp *pgrp; 1961 1962 if (pgid != 0) { 1963 sx_slock(&proctree_lock); 1964 pgrp = pgfind(pgid); 1965 sx_sunlock(&proctree_lock); 1966 if (pgrp != NULL) { 1967 pgsignal(pgrp, sig, 0, ksi); 1968 PGRP_UNLOCK(pgrp); 1969 } 1970 } 1971 } 1972 1973 /* 1974 * Send a signal to a process group. If checktty is 1, 1975 * limit to members which have a controlling terminal. 1976 */ 1977 void 1978 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1979 { 1980 struct proc *p; 1981 1982 if (pgrp) { 1983 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1984 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1985 PROC_LOCK(p); 1986 if (p->p_state == PRS_NORMAL && 1987 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1988 pksignal(p, sig, ksi); 1989 PROC_UNLOCK(p); 1990 } 1991 } 1992 } 1993 1994 /* 1995 * Recalculate the signal mask and reset the signal disposition after 1996 * usermode frame for delivery is formed. Should be called after 1997 * mach-specific routine, because sysent->sv_sendsig() needs correct 1998 * ps_siginfo and signal mask. 1999 */ 2000 static void 2001 postsig_done(int sig, struct thread *td, struct sigacts *ps) 2002 { 2003 sigset_t mask; 2004 2005 mtx_assert(&ps->ps_mtx, MA_OWNED); 2006 td->td_ru.ru_nsignals++; 2007 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2008 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2009 SIGADDSET(mask, sig); 2010 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2011 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2012 if (SIGISMEMBER(ps->ps_sigreset, sig)) 2013 sigdflt(ps, sig); 2014 } 2015 2016 /* 2017 * Send a signal caused by a trap to the current thread. If it will be 2018 * caught immediately, deliver it with correct code. Otherwise, post it 2019 * normally. 2020 */ 2021 void 2022 trapsignal(struct thread *td, ksiginfo_t *ksi) 2023 { 2024 struct sigacts *ps; 2025 struct proc *p; 2026 sigset_t sigmask; 2027 int code, sig; 2028 2029 p = td->td_proc; 2030 sig = ksi->ksi_signo; 2031 code = ksi->ksi_code; 2032 KASSERT(_SIG_VALID(sig), ("invalid signal")); 2033 2034 sigfastblock_fetch(td); 2035 PROC_LOCK(p); 2036 ps = p->p_sigacts; 2037 mtx_lock(&ps->ps_mtx); 2038 sigmask = td->td_sigmask; 2039 if (td->td_sigblock_val != 0) 2040 SIGSETOR(sigmask, fastblock_mask); 2041 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 2042 !SIGISMEMBER(sigmask, sig)) { 2043 #ifdef KTRACE 2044 if (KTRPOINT(curthread, KTR_PSIG)) 2045 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 2046 &td->td_sigmask, code); 2047 #endif 2048 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 2049 ksi, &td->td_sigmask); 2050 postsig_done(sig, td, ps); 2051 mtx_unlock(&ps->ps_mtx); 2052 } else { 2053 /* 2054 * Avoid a possible infinite loop if the thread 2055 * masking the signal or process is ignoring the 2056 * signal. 2057 */ 2058 if (kern_forcesigexit && (SIGISMEMBER(sigmask, sig) || 2059 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2060 SIGDELSET(td->td_sigmask, sig); 2061 SIGDELSET(ps->ps_sigcatch, sig); 2062 SIGDELSET(ps->ps_sigignore, sig); 2063 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2064 td->td_pflags &= ~TDP_SIGFASTBLOCK; 2065 td->td_sigblock_val = 0; 2066 } 2067 mtx_unlock(&ps->ps_mtx); 2068 p->p_sig = sig; /* XXX to verify code */ 2069 tdsendsignal(p, td, sig, ksi); 2070 } 2071 PROC_UNLOCK(p); 2072 } 2073 2074 static struct thread * 2075 sigtd(struct proc *p, int sig, bool fast_sigblock) 2076 { 2077 struct thread *td, *signal_td; 2078 2079 PROC_LOCK_ASSERT(p, MA_OWNED); 2080 MPASS(!fast_sigblock || p == curproc); 2081 2082 /* 2083 * Check if current thread can handle the signal without 2084 * switching context to another thread. 2085 */ 2086 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig) && 2087 (!fast_sigblock || curthread->td_sigblock_val == 0)) 2088 return (curthread); 2089 signal_td = NULL; 2090 FOREACH_THREAD_IN_PROC(p, td) { 2091 if (!SIGISMEMBER(td->td_sigmask, sig) && (!fast_sigblock || 2092 td != curthread || td->td_sigblock_val == 0)) { 2093 signal_td = td; 2094 break; 2095 } 2096 } 2097 if (signal_td == NULL) 2098 signal_td = FIRST_THREAD_IN_PROC(p); 2099 return (signal_td); 2100 } 2101 2102 /* 2103 * Send the signal to the process. If the signal has an action, the action 2104 * is usually performed by the target process rather than the caller; we add 2105 * the signal to the set of pending signals for the process. 2106 * 2107 * Exceptions: 2108 * o When a stop signal is sent to a sleeping process that takes the 2109 * default action, the process is stopped without awakening it. 2110 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2111 * regardless of the signal action (eg, blocked or ignored). 2112 * 2113 * Other ignored signals are discarded immediately. 2114 * 2115 * NB: This function may be entered from the debugger via the "kill" DDB 2116 * command. There is little that can be done to mitigate the possibly messy 2117 * side effects of this unwise possibility. 2118 */ 2119 void 2120 kern_psignal(struct proc *p, int sig) 2121 { 2122 ksiginfo_t ksi; 2123 2124 ksiginfo_init(&ksi); 2125 ksi.ksi_signo = sig; 2126 ksi.ksi_code = SI_KERNEL; 2127 (void) tdsendsignal(p, NULL, sig, &ksi); 2128 } 2129 2130 int 2131 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2132 { 2133 2134 return (tdsendsignal(p, NULL, sig, ksi)); 2135 } 2136 2137 /* Utility function for finding a thread to send signal event to. */ 2138 int 2139 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2140 { 2141 struct thread *td; 2142 2143 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2144 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2145 if (td == NULL) 2146 return (ESRCH); 2147 *ttd = td; 2148 } else { 2149 *ttd = NULL; 2150 PROC_LOCK(p); 2151 } 2152 return (0); 2153 } 2154 2155 void 2156 tdsignal(struct thread *td, int sig) 2157 { 2158 ksiginfo_t ksi; 2159 2160 ksiginfo_init(&ksi); 2161 ksi.ksi_signo = sig; 2162 ksi.ksi_code = SI_KERNEL; 2163 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2164 } 2165 2166 void 2167 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2168 { 2169 2170 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2171 } 2172 2173 int 2174 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2175 { 2176 sig_t action; 2177 sigqueue_t *sigqueue; 2178 int prop; 2179 struct sigacts *ps; 2180 int intrval; 2181 int ret = 0; 2182 int wakeup_swapper; 2183 2184 MPASS(td == NULL || p == td->td_proc); 2185 PROC_LOCK_ASSERT(p, MA_OWNED); 2186 2187 if (!_SIG_VALID(sig)) 2188 panic("%s(): invalid signal %d", __func__, sig); 2189 2190 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2191 2192 /* 2193 * IEEE Std 1003.1-2001: return success when killing a zombie. 2194 */ 2195 if (p->p_state == PRS_ZOMBIE) { 2196 if (ksi && (ksi->ksi_flags & KSI_INS)) 2197 ksiginfo_tryfree(ksi); 2198 return (ret); 2199 } 2200 2201 ps = p->p_sigacts; 2202 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2203 prop = sigprop(sig); 2204 2205 if (td == NULL) { 2206 td = sigtd(p, sig, false); 2207 sigqueue = &p->p_sigqueue; 2208 } else 2209 sigqueue = &td->td_sigqueue; 2210 2211 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2212 2213 /* 2214 * If the signal is being ignored, then we forget about it 2215 * immediately, except when the target process executes 2216 * sigwait(). (Note: we don't set SIGCONT in ps_sigignore, 2217 * and if it is set to SIG_IGN, action will be SIG_DFL here.) 2218 */ 2219 mtx_lock(&ps->ps_mtx); 2220 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2221 if (kern_sig_discard_ign && 2222 (p->p_sysent->sv_flags & SV_SIG_DISCIGN) == 0) { 2223 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2224 2225 mtx_unlock(&ps->ps_mtx); 2226 if (ksi && (ksi->ksi_flags & KSI_INS)) 2227 ksiginfo_tryfree(ksi); 2228 return (ret); 2229 } else { 2230 action = SIG_CATCH; 2231 } 2232 } else 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 mtx_unlock(&ps->ps_mtx); 2243 2244 if (prop & SIGPROP_CONT) 2245 sigqueue_delete_stopmask_proc(p); 2246 else if (prop & SIGPROP_STOP) { 2247 /* 2248 * If sending a tty stop signal to a member of an orphaned 2249 * process group, discard the signal here if the action 2250 * is default; don't stop the process below if sleeping, 2251 * and don't clear any pending SIGCONT. 2252 */ 2253 if ((prop & SIGPROP_TTYSTOP) != 0 && 2254 (p->p_pgrp->pg_flags & PGRP_ORPHANED) != 0 && 2255 action == SIG_DFL) { 2256 if (ksi && (ksi->ksi_flags & KSI_INS)) 2257 ksiginfo_tryfree(ksi); 2258 return (ret); 2259 } 2260 sigqueue_delete_proc(p, SIGCONT); 2261 if (p->p_flag & P_CONTINUED) { 2262 p->p_flag &= ~P_CONTINUED; 2263 PROC_LOCK(p->p_pptr); 2264 sigqueue_take(p->p_ksi); 2265 PROC_UNLOCK(p->p_pptr); 2266 } 2267 } 2268 2269 ret = sigqueue_add(sigqueue, sig, ksi); 2270 if (ret != 0) 2271 return (ret); 2272 signotify(td); 2273 /* 2274 * Defer further processing for signals which are held, 2275 * except that stopped processes must be continued by SIGCONT. 2276 */ 2277 if (action == SIG_HOLD && 2278 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2279 return (ret); 2280 2281 wakeup_swapper = 0; 2282 2283 /* 2284 * Some signals have a process-wide effect and a per-thread 2285 * component. Most processing occurs when the process next 2286 * tries to cross the user boundary, however there are some 2287 * times when processing needs to be done immediately, such as 2288 * waking up threads so that they can cross the user boundary. 2289 * We try to do the per-process part here. 2290 */ 2291 if (P_SHOULDSTOP(p)) { 2292 KASSERT(!(p->p_flag & P_WEXIT), 2293 ("signal to stopped but exiting process")); 2294 if (sig == SIGKILL) { 2295 /* 2296 * If traced process is already stopped, 2297 * then no further action is necessary. 2298 */ 2299 if (p->p_flag & P_TRACED) 2300 goto out; 2301 /* 2302 * SIGKILL sets process running. 2303 * It will die elsewhere. 2304 * All threads must be restarted. 2305 */ 2306 p->p_flag &= ~P_STOPPED_SIG; 2307 goto runfast; 2308 } 2309 2310 if (prop & SIGPROP_CONT) { 2311 /* 2312 * If traced process is already stopped, 2313 * then no further action is necessary. 2314 */ 2315 if (p->p_flag & P_TRACED) 2316 goto out; 2317 /* 2318 * If SIGCONT is default (or ignored), we continue the 2319 * process but don't leave the signal in sigqueue as 2320 * it has no further action. If SIGCONT is held, we 2321 * continue the process and leave the signal in 2322 * sigqueue. If the process catches SIGCONT, let it 2323 * handle the signal itself. If it isn't waiting on 2324 * an event, it goes back to run state. 2325 * Otherwise, process goes back to sleep state. 2326 */ 2327 p->p_flag &= ~P_STOPPED_SIG; 2328 PROC_SLOCK(p); 2329 if (p->p_numthreads == p->p_suspcount) { 2330 PROC_SUNLOCK(p); 2331 p->p_flag |= P_CONTINUED; 2332 p->p_xsig = SIGCONT; 2333 PROC_LOCK(p->p_pptr); 2334 childproc_continued(p); 2335 PROC_UNLOCK(p->p_pptr); 2336 PROC_SLOCK(p); 2337 } 2338 if (action == SIG_DFL) { 2339 thread_unsuspend(p); 2340 PROC_SUNLOCK(p); 2341 sigqueue_delete(sigqueue, sig); 2342 goto out_cont; 2343 } 2344 if (action == SIG_CATCH) { 2345 /* 2346 * The process wants to catch it so it needs 2347 * to run at least one thread, but which one? 2348 */ 2349 PROC_SUNLOCK(p); 2350 goto runfast; 2351 } 2352 /* 2353 * The signal is not ignored or caught. 2354 */ 2355 thread_unsuspend(p); 2356 PROC_SUNLOCK(p); 2357 goto out_cont; 2358 } 2359 2360 if (prop & SIGPROP_STOP) { 2361 /* 2362 * If traced process is already stopped, 2363 * then no further action is necessary. 2364 */ 2365 if (p->p_flag & P_TRACED) 2366 goto out; 2367 /* 2368 * Already stopped, don't need to stop again 2369 * (If we did the shell could get confused). 2370 * Just make sure the signal STOP bit set. 2371 */ 2372 p->p_flag |= P_STOPPED_SIG; 2373 sigqueue_delete(sigqueue, sig); 2374 goto out; 2375 } 2376 2377 /* 2378 * All other kinds of signals: 2379 * If a thread is sleeping interruptibly, simulate a 2380 * wakeup so that when it is continued it will be made 2381 * runnable and can look at the signal. However, don't make 2382 * the PROCESS runnable, leave it stopped. 2383 * It may run a bit until it hits a thread_suspend_check(). 2384 */ 2385 PROC_SLOCK(p); 2386 thread_lock(td); 2387 if (TD_CAN_ABORT(td)) 2388 wakeup_swapper = sleepq_abort(td, intrval); 2389 else 2390 thread_unlock(td); 2391 PROC_SUNLOCK(p); 2392 goto out; 2393 /* 2394 * Mutexes are short lived. Threads waiting on them will 2395 * hit thread_suspend_check() soon. 2396 */ 2397 } else if (p->p_state == PRS_NORMAL) { 2398 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2399 tdsigwakeup(td, sig, action, intrval); 2400 goto out; 2401 } 2402 2403 MPASS(action == SIG_DFL); 2404 2405 if (prop & SIGPROP_STOP) { 2406 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2407 goto out; 2408 p->p_flag |= P_STOPPED_SIG; 2409 p->p_xsig = sig; 2410 PROC_SLOCK(p); 2411 wakeup_swapper = sig_suspend_threads(td, p, 1); 2412 if (p->p_numthreads == p->p_suspcount) { 2413 /* 2414 * only thread sending signal to another 2415 * process can reach here, if thread is sending 2416 * signal to its process, because thread does 2417 * not suspend itself here, p_numthreads 2418 * should never be equal to p_suspcount. 2419 */ 2420 thread_stopped(p); 2421 PROC_SUNLOCK(p); 2422 sigqueue_delete_proc(p, p->p_xsig); 2423 } else 2424 PROC_SUNLOCK(p); 2425 goto out; 2426 } 2427 } else { 2428 /* Not in "NORMAL" state. discard the signal. */ 2429 sigqueue_delete(sigqueue, sig); 2430 goto out; 2431 } 2432 2433 /* 2434 * The process is not stopped so we need to apply the signal to all the 2435 * running threads. 2436 */ 2437 runfast: 2438 tdsigwakeup(td, sig, action, intrval); 2439 PROC_SLOCK(p); 2440 thread_unsuspend(p); 2441 PROC_SUNLOCK(p); 2442 out_cont: 2443 itimer_proc_continue(p); 2444 kqtimer_proc_continue(p); 2445 out: 2446 /* If we jump here, proc slock should not be owned. */ 2447 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2448 if (wakeup_swapper) 2449 kick_proc0(); 2450 2451 return (ret); 2452 } 2453 2454 /* 2455 * The force of a signal has been directed against a single 2456 * thread. We need to see what we can do about knocking it 2457 * out of any sleep it may be in etc. 2458 */ 2459 static void 2460 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2461 { 2462 struct proc *p = td->td_proc; 2463 int prop, wakeup_swapper; 2464 2465 PROC_LOCK_ASSERT(p, MA_OWNED); 2466 prop = sigprop(sig); 2467 2468 PROC_SLOCK(p); 2469 thread_lock(td); 2470 /* 2471 * Bring the priority of a thread up if we want it to get 2472 * killed in this lifetime. Be careful to avoid bumping the 2473 * priority of the idle thread, since we still allow to signal 2474 * kernel processes. 2475 */ 2476 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2477 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2478 sched_prio(td, PUSER); 2479 if (TD_ON_SLEEPQ(td)) { 2480 /* 2481 * If thread is sleeping uninterruptibly 2482 * we can't interrupt the sleep... the signal will 2483 * be noticed when the process returns through 2484 * trap() or syscall(). 2485 */ 2486 if ((td->td_flags & TDF_SINTR) == 0) 2487 goto out; 2488 /* 2489 * If SIGCONT is default (or ignored) and process is 2490 * asleep, we are finished; the process should not 2491 * be awakened. 2492 */ 2493 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2494 thread_unlock(td); 2495 PROC_SUNLOCK(p); 2496 sigqueue_delete(&p->p_sigqueue, sig); 2497 /* 2498 * It may be on either list in this state. 2499 * Remove from both for now. 2500 */ 2501 sigqueue_delete(&td->td_sigqueue, sig); 2502 return; 2503 } 2504 2505 /* 2506 * Don't awaken a sleeping thread for SIGSTOP if the 2507 * STOP signal is deferred. 2508 */ 2509 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2510 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2511 goto out; 2512 2513 /* 2514 * Give low priority threads a better chance to run. 2515 */ 2516 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2517 sched_prio(td, PUSER); 2518 2519 wakeup_swapper = sleepq_abort(td, intrval); 2520 PROC_SUNLOCK(p); 2521 if (wakeup_swapper) 2522 kick_proc0(); 2523 return; 2524 } 2525 2526 /* 2527 * Other states do nothing with the signal immediately, 2528 * other than kicking ourselves if we are running. 2529 * It will either never be noticed, or noticed very soon. 2530 */ 2531 #ifdef SMP 2532 if (TD_IS_RUNNING(td) && td != curthread) 2533 forward_signal(td); 2534 #endif 2535 2536 out: 2537 PROC_SUNLOCK(p); 2538 thread_unlock(td); 2539 } 2540 2541 static void 2542 ptrace_coredump(struct thread *td) 2543 { 2544 struct proc *p; 2545 struct thr_coredump_req *tcq; 2546 void *rl_cookie; 2547 2548 MPASS(td == curthread); 2549 p = td->td_proc; 2550 PROC_LOCK_ASSERT(p, MA_OWNED); 2551 if ((td->td_dbgflags & TDB_COREDUMPRQ) == 0) 2552 return; 2553 KASSERT((p->p_flag & P_STOPPED_TRACE) != 0, ("not stopped")); 2554 2555 tcq = td->td_coredump; 2556 KASSERT(tcq != NULL, ("td_coredump is NULL")); 2557 2558 if (p->p_sysent->sv_coredump == NULL) { 2559 tcq->tc_error = ENOSYS; 2560 goto wake; 2561 } 2562 2563 PROC_UNLOCK(p); 2564 rl_cookie = vn_rangelock_wlock(tcq->tc_vp, 0, OFF_MAX); 2565 2566 tcq->tc_error = p->p_sysent->sv_coredump(td, tcq->tc_vp, 2567 tcq->tc_limit, tcq->tc_flags); 2568 2569 vn_rangelock_unlock(tcq->tc_vp, rl_cookie); 2570 PROC_LOCK(p); 2571 wake: 2572 td->td_dbgflags &= ~TDB_COREDUMPRQ; 2573 td->td_coredump = NULL; 2574 wakeup(p); 2575 } 2576 2577 static int 2578 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2579 { 2580 struct thread *td2; 2581 int wakeup_swapper; 2582 2583 PROC_LOCK_ASSERT(p, MA_OWNED); 2584 PROC_SLOCK_ASSERT(p, MA_OWNED); 2585 MPASS(sending || td == curthread); 2586 2587 wakeup_swapper = 0; 2588 FOREACH_THREAD_IN_PROC(p, td2) { 2589 thread_lock(td2); 2590 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2591 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2592 (td2->td_flags & TDF_SINTR)) { 2593 if (td2->td_flags & TDF_SBDRY) { 2594 /* 2595 * Once a thread is asleep with 2596 * TDF_SBDRY and without TDF_SERESTART 2597 * or TDF_SEINTR set, it should never 2598 * become suspended due to this check. 2599 */ 2600 KASSERT(!TD_IS_SUSPENDED(td2), 2601 ("thread with deferred stops suspended")); 2602 if (TD_SBDRY_INTR(td2)) { 2603 wakeup_swapper |= sleepq_abort(td2, 2604 TD_SBDRY_ERRNO(td2)); 2605 continue; 2606 } 2607 } else if (!TD_IS_SUSPENDED(td2)) 2608 thread_suspend_one(td2); 2609 } else if (!TD_IS_SUSPENDED(td2)) { 2610 if (sending || td != td2) 2611 td2->td_flags |= TDF_ASTPENDING; 2612 #ifdef SMP 2613 if (TD_IS_RUNNING(td2) && td2 != td) 2614 forward_signal(td2); 2615 #endif 2616 } 2617 thread_unlock(td2); 2618 } 2619 return (wakeup_swapper); 2620 } 2621 2622 /* 2623 * Stop the process for an event deemed interesting to the debugger. If si is 2624 * non-NULL, this is a signal exchange; the new signal requested by the 2625 * debugger will be returned for handling. If si is NULL, this is some other 2626 * type of interesting event. The debugger may request a signal be delivered in 2627 * that case as well, however it will be deferred until it can be handled. 2628 */ 2629 int 2630 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2631 { 2632 struct proc *p = td->td_proc; 2633 struct thread *td2; 2634 ksiginfo_t ksi; 2635 2636 PROC_LOCK_ASSERT(p, MA_OWNED); 2637 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2638 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2639 &p->p_mtx.lock_object, "Stopping for traced signal"); 2640 2641 td->td_xsig = sig; 2642 2643 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2644 td->td_dbgflags |= TDB_XSIG; 2645 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2646 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2647 PROC_SLOCK(p); 2648 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2649 if (P_KILLED(p)) { 2650 /* 2651 * Ensure that, if we've been PT_KILLed, the 2652 * exit status reflects that. Another thread 2653 * may also be in ptracestop(), having just 2654 * received the SIGKILL, but this thread was 2655 * unsuspended first. 2656 */ 2657 td->td_dbgflags &= ~TDB_XSIG; 2658 td->td_xsig = SIGKILL; 2659 p->p_ptevents = 0; 2660 break; 2661 } 2662 if (p->p_flag & P_SINGLE_EXIT && 2663 !(td->td_dbgflags & TDB_EXIT)) { 2664 /* 2665 * Ignore ptrace stops except for thread exit 2666 * events when the process exits. 2667 */ 2668 td->td_dbgflags &= ~TDB_XSIG; 2669 PROC_SUNLOCK(p); 2670 return (0); 2671 } 2672 2673 /* 2674 * Make wait(2) work. Ensure that right after the 2675 * attach, the thread which was decided to become the 2676 * leader of attach gets reported to the waiter. 2677 * Otherwise, just avoid overwriting another thread's 2678 * assignment to p_xthread. If another thread has 2679 * already set p_xthread, the current thread will get 2680 * a chance to report itself upon the next iteration. 2681 */ 2682 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2683 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2684 p->p_xthread == NULL)) { 2685 p->p_xsig = sig; 2686 p->p_xthread = td; 2687 2688 /* 2689 * If we are on sleepqueue already, 2690 * let sleepqueue code decide if it 2691 * needs to go sleep after attach. 2692 */ 2693 if (td->td_wchan == NULL) 2694 td->td_dbgflags &= ~TDB_FSTP; 2695 2696 p->p_flag2 &= ~P2_PTRACE_FSTP; 2697 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2698 sig_suspend_threads(td, p, 0); 2699 } 2700 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2701 td->td_dbgflags &= ~TDB_STOPATFORK; 2702 } 2703 stopme: 2704 td->td_dbgflags |= TDB_SSWITCH; 2705 thread_suspend_switch(td, p); 2706 td->td_dbgflags &= ~TDB_SSWITCH; 2707 if ((td->td_dbgflags & TDB_COREDUMPRQ) != 0) { 2708 PROC_SUNLOCK(p); 2709 ptrace_coredump(td); 2710 PROC_SLOCK(p); 2711 goto stopme; 2712 } 2713 if (p->p_xthread == td) 2714 p->p_xthread = NULL; 2715 if (!(p->p_flag & P_TRACED)) 2716 break; 2717 if (td->td_dbgflags & TDB_SUSPEND) { 2718 if (p->p_flag & P_SINGLE_EXIT) 2719 break; 2720 goto stopme; 2721 } 2722 } 2723 PROC_SUNLOCK(p); 2724 } 2725 2726 if (si != NULL && sig == td->td_xsig) { 2727 /* Parent wants us to take the original signal unchanged. */ 2728 si->ksi_flags |= KSI_HEAD; 2729 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2730 si->ksi_signo = 0; 2731 } else if (td->td_xsig != 0) { 2732 /* 2733 * If parent wants us to take a new signal, then it will leave 2734 * it in td->td_xsig; otherwise we just look for signals again. 2735 */ 2736 ksiginfo_init(&ksi); 2737 ksi.ksi_signo = td->td_xsig; 2738 ksi.ksi_flags |= KSI_PTRACE; 2739 td2 = sigtd(p, td->td_xsig, false); 2740 tdsendsignal(p, td2, td->td_xsig, &ksi); 2741 if (td != td2) 2742 return (0); 2743 } 2744 2745 return (td->td_xsig); 2746 } 2747 2748 static void 2749 reschedule_signals(struct proc *p, sigset_t block, int flags) 2750 { 2751 struct sigacts *ps; 2752 struct thread *td; 2753 int sig; 2754 bool fastblk, pslocked; 2755 2756 PROC_LOCK_ASSERT(p, MA_OWNED); 2757 ps = p->p_sigacts; 2758 pslocked = (flags & SIGPROCMASK_PS_LOCKED) != 0; 2759 mtx_assert(&ps->ps_mtx, pslocked ? MA_OWNED : MA_NOTOWNED); 2760 if (SIGISEMPTY(p->p_siglist)) 2761 return; 2762 SIGSETAND(block, p->p_siglist); 2763 fastblk = (flags & SIGPROCMASK_FASTBLK) != 0; 2764 while ((sig = sig_ffs(&block)) != 0) { 2765 SIGDELSET(block, sig); 2766 td = sigtd(p, sig, fastblk); 2767 2768 /* 2769 * If sigtd() selected us despite sigfastblock is 2770 * blocking, do not activate AST or wake us, to avoid 2771 * loop in AST handler. 2772 */ 2773 if (fastblk && td == curthread) 2774 continue; 2775 2776 signotify(td); 2777 if (!pslocked) 2778 mtx_lock(&ps->ps_mtx); 2779 if (p->p_flag & P_TRACED || 2780 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2781 !SIGISMEMBER(td->td_sigmask, sig))) { 2782 tdsigwakeup(td, sig, SIG_CATCH, 2783 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2784 ERESTART)); 2785 } 2786 if (!pslocked) 2787 mtx_unlock(&ps->ps_mtx); 2788 } 2789 } 2790 2791 void 2792 tdsigcleanup(struct thread *td) 2793 { 2794 struct proc *p; 2795 sigset_t unblocked; 2796 2797 p = td->td_proc; 2798 PROC_LOCK_ASSERT(p, MA_OWNED); 2799 2800 sigqueue_flush(&td->td_sigqueue); 2801 if (p->p_numthreads == 1) 2802 return; 2803 2804 /* 2805 * Since we cannot handle signals, notify signal post code 2806 * about this by filling the sigmask. 2807 * 2808 * Also, if needed, wake up thread(s) that do not block the 2809 * same signals as the exiting thread, since the thread might 2810 * have been selected for delivery and woken up. 2811 */ 2812 SIGFILLSET(unblocked); 2813 SIGSETNAND(unblocked, td->td_sigmask); 2814 SIGFILLSET(td->td_sigmask); 2815 reschedule_signals(p, unblocked, 0); 2816 2817 } 2818 2819 static int 2820 sigdeferstop_curr_flags(int cflags) 2821 { 2822 2823 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2824 (cflags & TDF_SBDRY) != 0); 2825 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2826 } 2827 2828 /* 2829 * Defer the delivery of SIGSTOP for the current thread, according to 2830 * the requested mode. Returns previous flags, which must be restored 2831 * by sigallowstop(). 2832 * 2833 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2834 * cleared by the current thread, which allow the lock-less read-only 2835 * accesses below. 2836 */ 2837 int 2838 sigdeferstop_impl(int mode) 2839 { 2840 struct thread *td; 2841 int cflags, nflags; 2842 2843 td = curthread; 2844 cflags = sigdeferstop_curr_flags(td->td_flags); 2845 switch (mode) { 2846 case SIGDEFERSTOP_NOP: 2847 nflags = cflags; 2848 break; 2849 case SIGDEFERSTOP_OFF: 2850 nflags = 0; 2851 break; 2852 case SIGDEFERSTOP_SILENT: 2853 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2854 break; 2855 case SIGDEFERSTOP_EINTR: 2856 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2857 break; 2858 case SIGDEFERSTOP_ERESTART: 2859 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2860 break; 2861 default: 2862 panic("sigdeferstop: invalid mode %x", mode); 2863 break; 2864 } 2865 if (cflags == nflags) 2866 return (SIGDEFERSTOP_VAL_NCHG); 2867 thread_lock(td); 2868 td->td_flags = (td->td_flags & ~cflags) | nflags; 2869 thread_unlock(td); 2870 return (cflags); 2871 } 2872 2873 /* 2874 * Restores the STOP handling mode, typically permitting the delivery 2875 * of SIGSTOP for the current thread. This does not immediately 2876 * suspend if a stop was posted. Instead, the thread will suspend 2877 * either via ast() or a subsequent interruptible sleep. 2878 */ 2879 void 2880 sigallowstop_impl(int prev) 2881 { 2882 struct thread *td; 2883 int cflags; 2884 2885 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2886 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2887 ("sigallowstop: incorrect previous mode %x", prev)); 2888 td = curthread; 2889 cflags = sigdeferstop_curr_flags(td->td_flags); 2890 if (cflags != prev) { 2891 thread_lock(td); 2892 td->td_flags = (td->td_flags & ~cflags) | prev; 2893 thread_unlock(td); 2894 } 2895 } 2896 2897 /* 2898 * If the current process has received a signal (should be caught or cause 2899 * termination, should interrupt current syscall), return the signal number. 2900 * Stop signals with default action are processed immediately, then cleared; 2901 * they aren't returned. This is checked after each entry to the system for 2902 * a syscall or trap (though this can usually be done without calling issignal 2903 * by checking the pending signal masks in cursig.) The normal call 2904 * sequence is 2905 * 2906 * while (sig = cursig(curthread)) 2907 * postsig(sig); 2908 */ 2909 static int 2910 issignal(struct thread *td) 2911 { 2912 struct proc *p; 2913 struct sigacts *ps; 2914 struct sigqueue *queue; 2915 sigset_t sigpending; 2916 ksiginfo_t ksi; 2917 int prop, sig; 2918 2919 p = td->td_proc; 2920 ps = p->p_sigacts; 2921 mtx_assert(&ps->ps_mtx, MA_OWNED); 2922 PROC_LOCK_ASSERT(p, MA_OWNED); 2923 for (;;) { 2924 sigpending = td->td_sigqueue.sq_signals; 2925 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2926 SIGSETNAND(sigpending, td->td_sigmask); 2927 2928 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2929 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2930 SIG_STOPSIGMASK(sigpending); 2931 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2932 return (0); 2933 2934 /* 2935 * Do fast sigblock if requested by usermode. Since 2936 * we do know that there was a signal pending at this 2937 * point, set the FAST_SIGBLOCK_PEND as indicator for 2938 * usermode to perform a dummy call to 2939 * FAST_SIGBLOCK_UNBLOCK, which causes immediate 2940 * delivery of postponed pending signal. 2941 */ 2942 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 2943 if (td->td_sigblock_val != 0) 2944 SIGSETNAND(sigpending, fastblock_mask); 2945 if (SIGISEMPTY(sigpending)) { 2946 td->td_pflags |= TDP_SIGFASTPENDING; 2947 return (0); 2948 } 2949 } 2950 2951 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2952 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2953 SIGISMEMBER(sigpending, SIGSTOP)) { 2954 /* 2955 * If debugger just attached, always consume 2956 * SIGSTOP from ptrace(PT_ATTACH) first, to 2957 * execute the debugger attach ritual in 2958 * order. 2959 */ 2960 sig = SIGSTOP; 2961 td->td_dbgflags |= TDB_FSTP; 2962 } else { 2963 sig = sig_ffs(&sigpending); 2964 } 2965 2966 /* 2967 * We should allow pending but ignored signals below 2968 * only if there is sigwait() active, or P_TRACED was 2969 * on when they were posted. 2970 */ 2971 if (SIGISMEMBER(ps->ps_sigignore, sig) && 2972 (p->p_flag & P_TRACED) == 0 && 2973 (td->td_pflags2 & TDP2_SIGWAIT) == 0) { 2974 sigqueue_delete(&td->td_sigqueue, sig); 2975 sigqueue_delete(&p->p_sigqueue, sig); 2976 continue; 2977 } 2978 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2979 /* 2980 * If traced, always stop. 2981 * Remove old signal from queue before the stop. 2982 * XXX shrug off debugger, it causes siginfo to 2983 * be thrown away. 2984 */ 2985 queue = &td->td_sigqueue; 2986 ksiginfo_init(&ksi); 2987 if (sigqueue_get(queue, sig, &ksi) == 0) { 2988 queue = &p->p_sigqueue; 2989 sigqueue_get(queue, sig, &ksi); 2990 } 2991 td->td_si = ksi.ksi_info; 2992 2993 mtx_unlock(&ps->ps_mtx); 2994 sig = ptracestop(td, sig, &ksi); 2995 mtx_lock(&ps->ps_mtx); 2996 2997 td->td_si.si_signo = 0; 2998 2999 /* 3000 * Keep looking if the debugger discarded or 3001 * replaced the signal. 3002 */ 3003 if (sig == 0) 3004 continue; 3005 3006 /* 3007 * If the signal became masked, re-queue it. 3008 */ 3009 if (SIGISMEMBER(td->td_sigmask, sig)) { 3010 ksi.ksi_flags |= KSI_HEAD; 3011 sigqueue_add(&p->p_sigqueue, sig, &ksi); 3012 continue; 3013 } 3014 3015 /* 3016 * If the traced bit got turned off, requeue 3017 * the signal and go back up to the top to 3018 * rescan signals. This ensures that p_sig* 3019 * and p_sigact are consistent. 3020 */ 3021 if ((p->p_flag & P_TRACED) == 0) { 3022 ksi.ksi_flags |= KSI_HEAD; 3023 sigqueue_add(queue, sig, &ksi); 3024 continue; 3025 } 3026 } 3027 3028 prop = sigprop(sig); 3029 3030 /* 3031 * Decide whether the signal should be returned. 3032 * Return the signal's number, or fall through 3033 * to clear it from the pending mask. 3034 */ 3035 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 3036 case (intptr_t)SIG_DFL: 3037 /* 3038 * Don't take default actions on system processes. 3039 */ 3040 if (p->p_pid <= 1) { 3041 #ifdef DIAGNOSTIC 3042 /* 3043 * Are you sure you want to ignore SIGSEGV 3044 * in init? XXX 3045 */ 3046 printf("Process (pid %lu) got signal %d\n", 3047 (u_long)p->p_pid, sig); 3048 #endif 3049 break; /* == ignore */ 3050 } 3051 /* 3052 * If there is a pending stop signal to process with 3053 * default action, stop here, then clear the signal. 3054 * Traced or exiting processes should ignore stops. 3055 * Additionally, a member of an orphaned process group 3056 * should ignore tty stops. 3057 */ 3058 if (prop & SIGPROP_STOP) { 3059 mtx_unlock(&ps->ps_mtx); 3060 if ((p->p_flag & (P_TRACED | P_WEXIT | 3061 P_SINGLE_EXIT)) != 0 || ((p->p_pgrp-> 3062 pg_flags & PGRP_ORPHANED) != 0 && 3063 (prop & SIGPROP_TTYSTOP) != 0)) { 3064 mtx_lock(&ps->ps_mtx); 3065 break; /* == ignore */ 3066 } 3067 if (TD_SBDRY_INTR(td)) { 3068 KASSERT((td->td_flags & TDF_SBDRY) != 0, 3069 ("lost TDF_SBDRY")); 3070 mtx_lock(&ps->ps_mtx); 3071 return (-1); 3072 } 3073 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 3074 &p->p_mtx.lock_object, "Catching SIGSTOP"); 3075 sigqueue_delete(&td->td_sigqueue, sig); 3076 sigqueue_delete(&p->p_sigqueue, sig); 3077 p->p_flag |= P_STOPPED_SIG; 3078 p->p_xsig = sig; 3079 PROC_SLOCK(p); 3080 sig_suspend_threads(td, p, 0); 3081 thread_suspend_switch(td, p); 3082 PROC_SUNLOCK(p); 3083 mtx_lock(&ps->ps_mtx); 3084 goto next; 3085 } else if ((prop & SIGPROP_IGNORE) != 0 && 3086 (td->td_pflags2 & TDP2_SIGWAIT) == 0) { 3087 /* 3088 * Default action is to ignore; drop it if 3089 * not in kern_sigtimedwait(). 3090 */ 3091 break; /* == ignore */ 3092 } else 3093 return (sig); 3094 /*NOTREACHED*/ 3095 3096 case (intptr_t)SIG_IGN: 3097 if ((td->td_pflags2 & TDP2_SIGWAIT) == 0) 3098 break; /* == ignore */ 3099 else 3100 return (sig); 3101 3102 default: 3103 /* 3104 * This signal has an action, let 3105 * postsig() process it. 3106 */ 3107 return (sig); 3108 } 3109 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 3110 sigqueue_delete(&p->p_sigqueue, sig); 3111 next:; 3112 } 3113 /* NOTREACHED */ 3114 } 3115 3116 void 3117 thread_stopped(struct proc *p) 3118 { 3119 int n; 3120 3121 PROC_LOCK_ASSERT(p, MA_OWNED); 3122 PROC_SLOCK_ASSERT(p, MA_OWNED); 3123 n = p->p_suspcount; 3124 if (p == curproc) 3125 n++; 3126 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 3127 PROC_SUNLOCK(p); 3128 p->p_flag &= ~P_WAITED; 3129 PROC_LOCK(p->p_pptr); 3130 childproc_stopped(p, (p->p_flag & P_TRACED) ? 3131 CLD_TRAPPED : CLD_STOPPED); 3132 PROC_UNLOCK(p->p_pptr); 3133 PROC_SLOCK(p); 3134 } 3135 } 3136 3137 /* 3138 * Take the action for the specified signal 3139 * from the current set of pending signals. 3140 */ 3141 int 3142 postsig(int sig) 3143 { 3144 struct thread *td; 3145 struct proc *p; 3146 struct sigacts *ps; 3147 sig_t action; 3148 ksiginfo_t ksi; 3149 sigset_t returnmask; 3150 3151 KASSERT(sig != 0, ("postsig")); 3152 3153 td = curthread; 3154 p = td->td_proc; 3155 PROC_LOCK_ASSERT(p, MA_OWNED); 3156 ps = p->p_sigacts; 3157 mtx_assert(&ps->ps_mtx, MA_OWNED); 3158 ksiginfo_init(&ksi); 3159 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3160 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3161 return (0); 3162 ksi.ksi_signo = sig; 3163 if (ksi.ksi_code == SI_TIMER) 3164 itimer_accept(p, ksi.ksi_timerid, &ksi); 3165 action = ps->ps_sigact[_SIG_IDX(sig)]; 3166 #ifdef KTRACE 3167 if (KTRPOINT(td, KTR_PSIG)) 3168 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3169 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3170 #endif 3171 3172 if (action == SIG_DFL) { 3173 /* 3174 * Default action, where the default is to kill 3175 * the process. (Other cases were ignored above.) 3176 */ 3177 mtx_unlock(&ps->ps_mtx); 3178 proc_td_siginfo_capture(td, &ksi.ksi_info); 3179 sigexit(td, sig); 3180 /* NOTREACHED */ 3181 } else { 3182 /* 3183 * If we get here, the signal must be caught. 3184 */ 3185 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3186 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3187 ("postsig action: blocked sig %d", sig)); 3188 3189 /* 3190 * Set the new mask value and also defer further 3191 * occurrences of this signal. 3192 * 3193 * Special case: user has done a sigsuspend. Here the 3194 * current mask is not of interest, but rather the 3195 * mask from before the sigsuspend is what we want 3196 * restored after the signal processing is completed. 3197 */ 3198 if (td->td_pflags & TDP_OLDMASK) { 3199 returnmask = td->td_oldsigmask; 3200 td->td_pflags &= ~TDP_OLDMASK; 3201 } else 3202 returnmask = td->td_sigmask; 3203 3204 if (p->p_sig == sig) { 3205 p->p_sig = 0; 3206 } 3207 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3208 postsig_done(sig, td, ps); 3209 } 3210 return (1); 3211 } 3212 3213 int 3214 sig_ast_checksusp(struct thread *td) 3215 { 3216 struct proc *p; 3217 int ret; 3218 3219 p = td->td_proc; 3220 PROC_LOCK_ASSERT(p, MA_OWNED); 3221 3222 if ((td->td_flags & TDF_NEEDSUSPCHK) == 0) 3223 return (0); 3224 3225 ret = thread_suspend_check(1); 3226 MPASS(ret == 0 || ret == EINTR || ret == ERESTART); 3227 return (ret); 3228 } 3229 3230 int 3231 sig_ast_needsigchk(struct thread *td) 3232 { 3233 struct proc *p; 3234 struct sigacts *ps; 3235 int ret, sig; 3236 3237 p = td->td_proc; 3238 PROC_LOCK_ASSERT(p, MA_OWNED); 3239 3240 if ((td->td_flags & TDF_NEEDSIGCHK) == 0) 3241 return (0); 3242 3243 ps = p->p_sigacts; 3244 mtx_lock(&ps->ps_mtx); 3245 sig = cursig(td); 3246 if (sig == -1) { 3247 mtx_unlock(&ps->ps_mtx); 3248 KASSERT((td->td_flags & TDF_SBDRY) != 0, ("lost TDF_SBDRY")); 3249 KASSERT(TD_SBDRY_INTR(td), 3250 ("lost TDF_SERESTART of TDF_SEINTR")); 3251 KASSERT((td->td_flags & (TDF_SEINTR | TDF_SERESTART)) != 3252 (TDF_SEINTR | TDF_SERESTART), 3253 ("both TDF_SEINTR and TDF_SERESTART")); 3254 ret = TD_SBDRY_ERRNO(td); 3255 } else if (sig != 0) { 3256 ret = SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : ERESTART; 3257 mtx_unlock(&ps->ps_mtx); 3258 } else { 3259 mtx_unlock(&ps->ps_mtx); 3260 ret = 0; 3261 } 3262 3263 /* 3264 * Do not go into sleep if this thread was the ptrace(2) 3265 * attach leader. cursig() consumed SIGSTOP from PT_ATTACH, 3266 * but we usually act on the signal by interrupting sleep, and 3267 * should do that here as well. 3268 */ 3269 if ((td->td_dbgflags & TDB_FSTP) != 0) { 3270 if (ret == 0) 3271 ret = EINTR; 3272 td->td_dbgflags &= ~TDB_FSTP; 3273 } 3274 3275 return (ret); 3276 } 3277 3278 int 3279 sig_intr(void) 3280 { 3281 struct thread *td; 3282 struct proc *p; 3283 int ret; 3284 3285 td = curthread; 3286 if ((td->td_flags & (TDF_NEEDSIGCHK | TDF_NEEDSUSPCHK)) == 0) 3287 return (0); 3288 3289 p = td->td_proc; 3290 3291 PROC_LOCK(p); 3292 ret = sig_ast_checksusp(td); 3293 if (ret == 0) 3294 ret = sig_ast_needsigchk(td); 3295 PROC_UNLOCK(p); 3296 return (ret); 3297 } 3298 3299 void 3300 proc_wkilled(struct proc *p) 3301 { 3302 3303 PROC_LOCK_ASSERT(p, MA_OWNED); 3304 if ((p->p_flag & P_WKILLED) == 0) { 3305 p->p_flag |= P_WKILLED; 3306 /* 3307 * Notify swapper that there is a process to swap in. 3308 * The notification is racy, at worst it would take 10 3309 * seconds for the swapper process to notice. 3310 */ 3311 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3312 wakeup(&proc0); 3313 } 3314 } 3315 3316 /* 3317 * Kill the current process for stated reason. 3318 */ 3319 void 3320 killproc(struct proc *p, const char *why) 3321 { 3322 3323 PROC_LOCK_ASSERT(p, MA_OWNED); 3324 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3325 p->p_comm); 3326 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3327 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3328 p->p_ucred->cr_uid, why); 3329 proc_wkilled(p); 3330 kern_psignal(p, SIGKILL); 3331 } 3332 3333 /* 3334 * Force the current process to exit with the specified signal, dumping core 3335 * if appropriate. We bypass the normal tests for masked and caught signals, 3336 * allowing unrecoverable failures to terminate the process without changing 3337 * signal state. Mark the accounting record with the signal termination. 3338 * If dumping core, save the signal number for the debugger. Calls exit and 3339 * does not return. 3340 */ 3341 void 3342 sigexit(struct thread *td, int sig) 3343 { 3344 struct proc *p = td->td_proc; 3345 3346 PROC_LOCK_ASSERT(p, MA_OWNED); 3347 p->p_acflag |= AXSIG; 3348 /* 3349 * We must be single-threading to generate a core dump. This 3350 * ensures that the registers in the core file are up-to-date. 3351 * Also, the ELF dump handler assumes that the thread list doesn't 3352 * change out from under it. 3353 * 3354 * XXX If another thread attempts to single-thread before us 3355 * (e.g. via fork()), we won't get a dump at all. 3356 */ 3357 if ((sigprop(sig) & SIGPROP_CORE) && 3358 thread_single(p, SINGLE_NO_EXIT) == 0) { 3359 p->p_sig = sig; 3360 /* 3361 * Log signals which would cause core dumps 3362 * (Log as LOG_INFO to appease those who don't want 3363 * these messages.) 3364 * XXX : Todo, as well as euid, write out ruid too 3365 * Note that coredump() drops proc lock. 3366 */ 3367 if (coredump(td) == 0) 3368 sig |= WCOREFLAG; 3369 if (kern_logsigexit) 3370 log(LOG_INFO, 3371 "pid %d (%s), jid %d, uid %d: exited on " 3372 "signal %d%s\n", p->p_pid, p->p_comm, 3373 p->p_ucred->cr_prison->pr_id, 3374 td->td_ucred->cr_uid, 3375 sig &~ WCOREFLAG, 3376 sig & WCOREFLAG ? " (core dumped)" : ""); 3377 } else 3378 PROC_UNLOCK(p); 3379 exit1(td, 0, sig); 3380 /* NOTREACHED */ 3381 } 3382 3383 /* 3384 * Send queued SIGCHLD to parent when child process's state 3385 * is changed. 3386 */ 3387 static void 3388 sigparent(struct proc *p, int reason, int status) 3389 { 3390 PROC_LOCK_ASSERT(p, MA_OWNED); 3391 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3392 3393 if (p->p_ksi != NULL) { 3394 p->p_ksi->ksi_signo = SIGCHLD; 3395 p->p_ksi->ksi_code = reason; 3396 p->p_ksi->ksi_status = status; 3397 p->p_ksi->ksi_pid = p->p_pid; 3398 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3399 if (KSI_ONQ(p->p_ksi)) 3400 return; 3401 } 3402 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3403 } 3404 3405 static void 3406 childproc_jobstate(struct proc *p, int reason, int sig) 3407 { 3408 struct sigacts *ps; 3409 3410 PROC_LOCK_ASSERT(p, MA_OWNED); 3411 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3412 3413 /* 3414 * Wake up parent sleeping in kern_wait(), also send 3415 * SIGCHLD to parent, but SIGCHLD does not guarantee 3416 * that parent will awake, because parent may masked 3417 * the signal. 3418 */ 3419 p->p_pptr->p_flag |= P_STATCHILD; 3420 wakeup(p->p_pptr); 3421 3422 ps = p->p_pptr->p_sigacts; 3423 mtx_lock(&ps->ps_mtx); 3424 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3425 mtx_unlock(&ps->ps_mtx); 3426 sigparent(p, reason, sig); 3427 } else 3428 mtx_unlock(&ps->ps_mtx); 3429 } 3430 3431 void 3432 childproc_stopped(struct proc *p, int reason) 3433 { 3434 3435 childproc_jobstate(p, reason, p->p_xsig); 3436 } 3437 3438 void 3439 childproc_continued(struct proc *p) 3440 { 3441 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3442 } 3443 3444 void 3445 childproc_exited(struct proc *p) 3446 { 3447 int reason, status; 3448 3449 if (WCOREDUMP(p->p_xsig)) { 3450 reason = CLD_DUMPED; 3451 status = WTERMSIG(p->p_xsig); 3452 } else if (WIFSIGNALED(p->p_xsig)) { 3453 reason = CLD_KILLED; 3454 status = WTERMSIG(p->p_xsig); 3455 } else { 3456 reason = CLD_EXITED; 3457 status = p->p_xexit; 3458 } 3459 /* 3460 * XXX avoid calling wakeup(p->p_pptr), the work is 3461 * done in exit1(). 3462 */ 3463 sigparent(p, reason, status); 3464 } 3465 3466 #define MAX_NUM_CORE_FILES 100000 3467 #ifndef NUM_CORE_FILES 3468 #define NUM_CORE_FILES 5 3469 #endif 3470 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3471 static int num_cores = NUM_CORE_FILES; 3472 3473 static int 3474 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3475 { 3476 int error; 3477 int new_val; 3478 3479 new_val = num_cores; 3480 error = sysctl_handle_int(oidp, &new_val, 0, req); 3481 if (error != 0 || req->newptr == NULL) 3482 return (error); 3483 if (new_val > MAX_NUM_CORE_FILES) 3484 new_val = MAX_NUM_CORE_FILES; 3485 if (new_val < 0) 3486 new_val = 0; 3487 num_cores = new_val; 3488 return (0); 3489 } 3490 SYSCTL_PROC(_debug, OID_AUTO, ncores, 3491 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3492 sysctl_debug_num_cores_check, "I", 3493 "Maximum number of generated process corefiles while using index format"); 3494 3495 #define GZIP_SUFFIX ".gz" 3496 #define ZSTD_SUFFIX ".zst" 3497 3498 int compress_user_cores = 0; 3499 3500 static int 3501 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3502 { 3503 int error, val; 3504 3505 val = compress_user_cores; 3506 error = sysctl_handle_int(oidp, &val, 0, req); 3507 if (error != 0 || req->newptr == NULL) 3508 return (error); 3509 if (val != 0 && !compressor_avail(val)) 3510 return (EINVAL); 3511 compress_user_cores = val; 3512 return (error); 3513 } 3514 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, 3515 CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3516 sysctl_compress_user_cores, "I", 3517 "Enable compression of user corefiles (" 3518 __XSTRING(COMPRESS_GZIP) " = gzip, " 3519 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3520 3521 int compress_user_cores_level = 6; 3522 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3523 &compress_user_cores_level, 0, 3524 "Corefile compression level"); 3525 3526 /* 3527 * Protect the access to corefilename[] by allproc_lock. 3528 */ 3529 #define corefilename_lock allproc_lock 3530 3531 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3532 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3533 3534 static int 3535 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3536 { 3537 int error; 3538 3539 sx_xlock(&corefilename_lock); 3540 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3541 req); 3542 sx_xunlock(&corefilename_lock); 3543 3544 return (error); 3545 } 3546 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3547 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3548 "Process corefile name format string"); 3549 3550 static void 3551 vnode_close_locked(struct thread *td, struct vnode *vp) 3552 { 3553 3554 VOP_UNLOCK(vp); 3555 vn_close(vp, FWRITE, td->td_ucred, td); 3556 } 3557 3558 /* 3559 * If the core format has a %I in it, then we need to check 3560 * for existing corefiles before defining a name. 3561 * To do this we iterate over 0..ncores to find a 3562 * non-existing core file name to use. If all core files are 3563 * already used we choose the oldest one. 3564 */ 3565 static int 3566 corefile_open_last(struct thread *td, char *name, int indexpos, 3567 int indexlen, int ncores, struct vnode **vpp) 3568 { 3569 struct vnode *oldvp, *nextvp, *vp; 3570 struct vattr vattr; 3571 struct nameidata nd; 3572 int error, i, flags, oflags, cmode; 3573 char ch; 3574 struct timespec lasttime; 3575 3576 nextvp = oldvp = NULL; 3577 cmode = S_IRUSR | S_IWUSR; 3578 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3579 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3580 3581 for (i = 0; i < ncores; i++) { 3582 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3583 3584 ch = name[indexpos + indexlen]; 3585 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3586 i); 3587 name[indexpos + indexlen] = ch; 3588 3589 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3590 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3591 NULL); 3592 if (error != 0) 3593 break; 3594 3595 vp = nd.ni_vp; 3596 NDFREE(&nd, NDF_ONLY_PNBUF); 3597 if ((flags & O_CREAT) == O_CREAT) { 3598 nextvp = vp; 3599 break; 3600 } 3601 3602 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3603 if (error != 0) { 3604 vnode_close_locked(td, vp); 3605 break; 3606 } 3607 3608 if (oldvp == NULL || 3609 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3610 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3611 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3612 if (oldvp != NULL) 3613 vn_close(oldvp, FWRITE, td->td_ucred, td); 3614 oldvp = vp; 3615 VOP_UNLOCK(oldvp); 3616 lasttime = vattr.va_mtime; 3617 } else { 3618 vnode_close_locked(td, vp); 3619 } 3620 } 3621 3622 if (oldvp != NULL) { 3623 if (nextvp == NULL) { 3624 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3625 error = EFAULT; 3626 vn_close(oldvp, FWRITE, td->td_ucred, td); 3627 } else { 3628 nextvp = oldvp; 3629 error = vn_lock(nextvp, LK_EXCLUSIVE); 3630 if (error != 0) { 3631 vn_close(nextvp, FWRITE, td->td_ucred, 3632 td); 3633 nextvp = NULL; 3634 } 3635 } 3636 } else { 3637 vn_close(oldvp, FWRITE, td->td_ucred, td); 3638 } 3639 } 3640 if (error != 0) { 3641 if (nextvp != NULL) 3642 vnode_close_locked(td, oldvp); 3643 } else { 3644 *vpp = nextvp; 3645 } 3646 3647 return (error); 3648 } 3649 3650 /* 3651 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3652 * Expand the name described in corefilename, using name, uid, and pid 3653 * and open/create core file. 3654 * corefilename is a printf-like string, with three format specifiers: 3655 * %N name of process ("name") 3656 * %P process id (pid) 3657 * %U user id (uid) 3658 * For example, "%N.core" is the default; they can be disabled completely 3659 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3660 * This is controlled by the sysctl variable kern.corefile (see above). 3661 */ 3662 static int 3663 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3664 int compress, int signum, struct vnode **vpp, char **namep) 3665 { 3666 struct sbuf sb; 3667 struct nameidata nd; 3668 const char *format; 3669 char *hostname, *name; 3670 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3671 3672 hostname = NULL; 3673 format = corefilename; 3674 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3675 indexlen = 0; 3676 indexpos = -1; 3677 ncores = num_cores; 3678 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3679 sx_slock(&corefilename_lock); 3680 for (i = 0; format[i] != '\0'; i++) { 3681 switch (format[i]) { 3682 case '%': /* Format character */ 3683 i++; 3684 switch (format[i]) { 3685 case '%': 3686 sbuf_putc(&sb, '%'); 3687 break; 3688 case 'H': /* hostname */ 3689 if (hostname == NULL) { 3690 hostname = malloc(MAXHOSTNAMELEN, 3691 M_TEMP, M_WAITOK); 3692 } 3693 getcredhostname(td->td_ucred, hostname, 3694 MAXHOSTNAMELEN); 3695 sbuf_printf(&sb, "%s", hostname); 3696 break; 3697 case 'I': /* autoincrementing index */ 3698 if (indexpos != -1) { 3699 sbuf_printf(&sb, "%%I"); 3700 break; 3701 } 3702 3703 indexpos = sbuf_len(&sb); 3704 sbuf_printf(&sb, "%u", ncores - 1); 3705 indexlen = sbuf_len(&sb) - indexpos; 3706 break; 3707 case 'N': /* process name */ 3708 sbuf_printf(&sb, "%s", comm); 3709 break; 3710 case 'P': /* process id */ 3711 sbuf_printf(&sb, "%u", pid); 3712 break; 3713 case 'S': /* signal number */ 3714 sbuf_printf(&sb, "%i", signum); 3715 break; 3716 case 'U': /* user id */ 3717 sbuf_printf(&sb, "%u", uid); 3718 break; 3719 default: 3720 log(LOG_ERR, 3721 "Unknown format character %c in " 3722 "corename `%s'\n", format[i], format); 3723 break; 3724 } 3725 break; 3726 default: 3727 sbuf_putc(&sb, format[i]); 3728 break; 3729 } 3730 } 3731 sx_sunlock(&corefilename_lock); 3732 free(hostname, M_TEMP); 3733 if (compress == COMPRESS_GZIP) 3734 sbuf_printf(&sb, GZIP_SUFFIX); 3735 else if (compress == COMPRESS_ZSTD) 3736 sbuf_printf(&sb, ZSTD_SUFFIX); 3737 if (sbuf_error(&sb) != 0) { 3738 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3739 "long\n", (long)pid, comm, (u_long)uid); 3740 sbuf_delete(&sb); 3741 free(name, M_TEMP); 3742 return (ENOMEM); 3743 } 3744 sbuf_finish(&sb); 3745 sbuf_delete(&sb); 3746 3747 if (indexpos != -1) { 3748 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3749 vpp); 3750 if (error != 0) { 3751 log(LOG_ERR, 3752 "pid %d (%s), uid (%u): Path `%s' failed " 3753 "on initial open test, error = %d\n", 3754 pid, comm, uid, name, error); 3755 } 3756 } else { 3757 cmode = S_IRUSR | S_IWUSR; 3758 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3759 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3760 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3761 if ((td->td_proc->p_flag & P_SUGID) != 0) 3762 flags |= O_EXCL; 3763 3764 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3765 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3766 NULL); 3767 if (error == 0) { 3768 *vpp = nd.ni_vp; 3769 NDFREE(&nd, NDF_ONLY_PNBUF); 3770 } 3771 } 3772 3773 if (error != 0) { 3774 #ifdef AUDIT 3775 audit_proc_coredump(td, name, error); 3776 #endif 3777 free(name, M_TEMP); 3778 return (error); 3779 } 3780 *namep = name; 3781 return (0); 3782 } 3783 3784 /* 3785 * Dump a process' core. The main routine does some 3786 * policy checking, and creates the name of the coredump; 3787 * then it passes on a vnode and a size limit to the process-specific 3788 * coredump routine if there is one; if there _is not_ one, it returns 3789 * ENOSYS; otherwise it returns the error from the process-specific routine. 3790 */ 3791 3792 static int 3793 coredump(struct thread *td) 3794 { 3795 struct proc *p = td->td_proc; 3796 struct ucred *cred = td->td_ucred; 3797 struct vnode *vp; 3798 struct flock lf; 3799 struct vattr vattr; 3800 size_t fullpathsize; 3801 int error, error1, locked; 3802 char *name; /* name of corefile */ 3803 void *rl_cookie; 3804 off_t limit; 3805 char *fullpath, *freepath = NULL; 3806 struct sbuf *sb; 3807 3808 PROC_LOCK_ASSERT(p, MA_OWNED); 3809 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3810 3811 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3812 (p->p_flag2 & P2_NOTRACE) != 0) { 3813 PROC_UNLOCK(p); 3814 return (EFAULT); 3815 } 3816 3817 /* 3818 * Note that the bulk of limit checking is done after 3819 * the corefile is created. The exception is if the limit 3820 * for corefiles is 0, in which case we don't bother 3821 * creating the corefile at all. This layout means that 3822 * a corefile is truncated instead of not being created, 3823 * if it is larger than the limit. 3824 */ 3825 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3826 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3827 PROC_UNLOCK(p); 3828 return (EFBIG); 3829 } 3830 PROC_UNLOCK(p); 3831 3832 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3833 compress_user_cores, p->p_sig, &vp, &name); 3834 if (error != 0) 3835 return (error); 3836 3837 /* 3838 * Don't dump to non-regular files or files with links. 3839 * Do not dump into system files. Effective user must own the corefile. 3840 */ 3841 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3842 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 3843 vattr.va_uid != cred->cr_uid) { 3844 VOP_UNLOCK(vp); 3845 error = EFAULT; 3846 goto out; 3847 } 3848 3849 VOP_UNLOCK(vp); 3850 3851 /* Postpone other writers, including core dumps of other processes. */ 3852 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3853 3854 lf.l_whence = SEEK_SET; 3855 lf.l_start = 0; 3856 lf.l_len = 0; 3857 lf.l_type = F_WRLCK; 3858 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3859 3860 VATTR_NULL(&vattr); 3861 vattr.va_size = 0; 3862 if (set_core_nodump_flag) 3863 vattr.va_flags = UF_NODUMP; 3864 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3865 VOP_SETATTR(vp, &vattr, cred); 3866 VOP_UNLOCK(vp); 3867 PROC_LOCK(p); 3868 p->p_acflag |= ACORE; 3869 PROC_UNLOCK(p); 3870 3871 if (p->p_sysent->sv_coredump != NULL) { 3872 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3873 } else { 3874 error = ENOSYS; 3875 } 3876 3877 if (locked) { 3878 lf.l_type = F_UNLCK; 3879 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3880 } 3881 vn_rangelock_unlock(vp, rl_cookie); 3882 3883 /* 3884 * Notify the userland helper that a process triggered a core dump. 3885 * This allows the helper to run an automated debugging session. 3886 */ 3887 if (error != 0 || coredump_devctl == 0) 3888 goto out; 3889 sb = sbuf_new_auto(); 3890 if (vn_fullpath_global(p->p_textvp, &fullpath, &freepath) != 0) 3891 goto out2; 3892 sbuf_printf(sb, "comm=\""); 3893 devctl_safe_quote_sb(sb, fullpath); 3894 free(freepath, M_TEMP); 3895 sbuf_printf(sb, "\" core=\""); 3896 3897 /* 3898 * We can't lookup core file vp directly. When we're replacing a core, and 3899 * other random times, we flush the name cache, so it will fail. Instead, 3900 * if the path of the core is relative, add the current dir in front if it. 3901 */ 3902 if (name[0] != '/') { 3903 fullpathsize = MAXPATHLEN; 3904 freepath = malloc(fullpathsize, M_TEMP, M_WAITOK); 3905 if (vn_getcwd(freepath, &fullpath, &fullpathsize) != 0) { 3906 free(freepath, M_TEMP); 3907 goto out2; 3908 } 3909 devctl_safe_quote_sb(sb, fullpath); 3910 free(freepath, M_TEMP); 3911 sbuf_putc(sb, '/'); 3912 } 3913 devctl_safe_quote_sb(sb, name); 3914 sbuf_printf(sb, "\""); 3915 if (sbuf_finish(sb) == 0) 3916 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 3917 out2: 3918 sbuf_delete(sb); 3919 out: 3920 error1 = vn_close(vp, FWRITE, cred, td); 3921 if (error == 0) 3922 error = error1; 3923 #ifdef AUDIT 3924 audit_proc_coredump(td, name, error); 3925 #endif 3926 free(name, M_TEMP); 3927 return (error); 3928 } 3929 3930 /* 3931 * Nonexistent system call-- signal process (may want to handle it). Flag 3932 * error in case process won't see signal immediately (blocked or ignored). 3933 */ 3934 #ifndef _SYS_SYSPROTO_H_ 3935 struct nosys_args { 3936 int dummy; 3937 }; 3938 #endif 3939 /* ARGSUSED */ 3940 int 3941 nosys(struct thread *td, struct nosys_args *args) 3942 { 3943 struct proc *p; 3944 3945 p = td->td_proc; 3946 3947 PROC_LOCK(p); 3948 tdsignal(td, SIGSYS); 3949 PROC_UNLOCK(p); 3950 if (kern_lognosys == 1 || kern_lognosys == 3) { 3951 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3952 td->td_sa.code); 3953 } 3954 if (kern_lognosys == 2 || kern_lognosys == 3 || 3955 (p->p_pid == 1 && (kern_lognosys & 3) == 0)) { 3956 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3957 td->td_sa.code); 3958 } 3959 return (ENOSYS); 3960 } 3961 3962 /* 3963 * Send a SIGIO or SIGURG signal to a process or process group using stored 3964 * credentials rather than those of the current process. 3965 */ 3966 void 3967 pgsigio(struct sigio **sigiop, int sig, int checkctty) 3968 { 3969 ksiginfo_t ksi; 3970 struct sigio *sigio; 3971 3972 ksiginfo_init(&ksi); 3973 ksi.ksi_signo = sig; 3974 ksi.ksi_code = SI_KERNEL; 3975 3976 SIGIO_LOCK(); 3977 sigio = *sigiop; 3978 if (sigio == NULL) { 3979 SIGIO_UNLOCK(); 3980 return; 3981 } 3982 if (sigio->sio_pgid > 0) { 3983 PROC_LOCK(sigio->sio_proc); 3984 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3985 kern_psignal(sigio->sio_proc, sig); 3986 PROC_UNLOCK(sigio->sio_proc); 3987 } else if (sigio->sio_pgid < 0) { 3988 struct proc *p; 3989 3990 PGRP_LOCK(sigio->sio_pgrp); 3991 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3992 PROC_LOCK(p); 3993 if (p->p_state == PRS_NORMAL && 3994 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3995 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3996 kern_psignal(p, sig); 3997 PROC_UNLOCK(p); 3998 } 3999 PGRP_UNLOCK(sigio->sio_pgrp); 4000 } 4001 SIGIO_UNLOCK(); 4002 } 4003 4004 static int 4005 filt_sigattach(struct knote *kn) 4006 { 4007 struct proc *p = curproc; 4008 4009 kn->kn_ptr.p_proc = p; 4010 kn->kn_flags |= EV_CLEAR; /* automatically set */ 4011 4012 knlist_add(p->p_klist, kn, 0); 4013 4014 return (0); 4015 } 4016 4017 static void 4018 filt_sigdetach(struct knote *kn) 4019 { 4020 struct proc *p = kn->kn_ptr.p_proc; 4021 4022 knlist_remove(p->p_klist, kn, 0); 4023 } 4024 4025 /* 4026 * signal knotes are shared with proc knotes, so we apply a mask to 4027 * the hint in order to differentiate them from process hints. This 4028 * could be avoided by using a signal-specific knote list, but probably 4029 * isn't worth the trouble. 4030 */ 4031 static int 4032 filt_signal(struct knote *kn, long hint) 4033 { 4034 4035 if (hint & NOTE_SIGNAL) { 4036 hint &= ~NOTE_SIGNAL; 4037 4038 if (kn->kn_id == hint) 4039 kn->kn_data++; 4040 } 4041 return (kn->kn_data != 0); 4042 } 4043 4044 struct sigacts * 4045 sigacts_alloc(void) 4046 { 4047 struct sigacts *ps; 4048 4049 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 4050 refcount_init(&ps->ps_refcnt, 1); 4051 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 4052 return (ps); 4053 } 4054 4055 void 4056 sigacts_free(struct sigacts *ps) 4057 { 4058 4059 if (refcount_release(&ps->ps_refcnt) == 0) 4060 return; 4061 mtx_destroy(&ps->ps_mtx); 4062 free(ps, M_SUBPROC); 4063 } 4064 4065 struct sigacts * 4066 sigacts_hold(struct sigacts *ps) 4067 { 4068 4069 refcount_acquire(&ps->ps_refcnt); 4070 return (ps); 4071 } 4072 4073 void 4074 sigacts_copy(struct sigacts *dest, struct sigacts *src) 4075 { 4076 4077 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 4078 mtx_lock(&src->ps_mtx); 4079 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 4080 mtx_unlock(&src->ps_mtx); 4081 } 4082 4083 int 4084 sigacts_shared(struct sigacts *ps) 4085 { 4086 4087 return (ps->ps_refcnt > 1); 4088 } 4089 4090 void 4091 sig_drop_caught(struct proc *p) 4092 { 4093 int sig; 4094 struct sigacts *ps; 4095 4096 ps = p->p_sigacts; 4097 PROC_LOCK_ASSERT(p, MA_OWNED); 4098 mtx_assert(&ps->ps_mtx, MA_OWNED); 4099 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 4100 sig = sig_ffs(&ps->ps_sigcatch); 4101 sigdflt(ps, sig); 4102 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 4103 sigqueue_delete_proc(p, sig); 4104 } 4105 } 4106 4107 static void 4108 sigfastblock_failed(struct thread *td, bool sendsig, bool write) 4109 { 4110 ksiginfo_t ksi; 4111 4112 /* 4113 * Prevent further fetches and SIGSEGVs, allowing thread to 4114 * issue syscalls despite corruption. 4115 */ 4116 sigfastblock_clear(td); 4117 4118 if (!sendsig) 4119 return; 4120 ksiginfo_init_trap(&ksi); 4121 ksi.ksi_signo = SIGSEGV; 4122 ksi.ksi_code = write ? SEGV_ACCERR : SEGV_MAPERR; 4123 ksi.ksi_addr = td->td_sigblock_ptr; 4124 trapsignal(td, &ksi); 4125 } 4126 4127 static bool 4128 sigfastblock_fetch_sig(struct thread *td, bool sendsig, uint32_t *valp) 4129 { 4130 uint32_t res; 4131 4132 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4133 return (true); 4134 if (fueword32((void *)td->td_sigblock_ptr, &res) == -1) { 4135 sigfastblock_failed(td, sendsig, false); 4136 return (false); 4137 } 4138 *valp = res; 4139 td->td_sigblock_val = res & ~SIGFASTBLOCK_FLAGS; 4140 return (true); 4141 } 4142 4143 static void 4144 sigfastblock_resched(struct thread *td, bool resched) 4145 { 4146 struct proc *p; 4147 4148 if (resched) { 4149 p = td->td_proc; 4150 PROC_LOCK(p); 4151 reschedule_signals(p, td->td_sigmask, 0); 4152 PROC_UNLOCK(p); 4153 } 4154 thread_lock(td); 4155 td->td_flags |= TDF_ASTPENDING | TDF_NEEDSIGCHK; 4156 thread_unlock(td); 4157 } 4158 4159 int 4160 sys_sigfastblock(struct thread *td, struct sigfastblock_args *uap) 4161 { 4162 struct proc *p; 4163 int error, res; 4164 uint32_t oldval; 4165 4166 error = 0; 4167 p = td->td_proc; 4168 switch (uap->cmd) { 4169 case SIGFASTBLOCK_SETPTR: 4170 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 4171 error = EBUSY; 4172 break; 4173 } 4174 if (((uintptr_t)(uap->ptr) & (sizeof(uint32_t) - 1)) != 0) { 4175 error = EINVAL; 4176 break; 4177 } 4178 td->td_pflags |= TDP_SIGFASTBLOCK; 4179 td->td_sigblock_ptr = uap->ptr; 4180 break; 4181 4182 case SIGFASTBLOCK_UNBLOCK: 4183 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4184 error = EINVAL; 4185 break; 4186 } 4187 4188 for (;;) { 4189 res = casueword32(td->td_sigblock_ptr, 4190 SIGFASTBLOCK_PEND, &oldval, 0); 4191 if (res == -1) { 4192 error = EFAULT; 4193 sigfastblock_failed(td, false, true); 4194 break; 4195 } 4196 if (res == 0) 4197 break; 4198 MPASS(res == 1); 4199 if (oldval != SIGFASTBLOCK_PEND) { 4200 error = EBUSY; 4201 break; 4202 } 4203 error = thread_check_susp(td, false); 4204 if (error != 0) 4205 break; 4206 } 4207 if (error != 0) 4208 break; 4209 4210 /* 4211 * td_sigblock_val is cleared there, but not on a 4212 * syscall exit. The end effect is that a single 4213 * interruptible sleep, while user sigblock word is 4214 * set, might return EINTR or ERESTART to usermode 4215 * without delivering signal. All further sleeps, 4216 * until userspace clears the word and does 4217 * sigfastblock(UNBLOCK), observe current word and no 4218 * longer get interrupted. It is slight 4219 * non-conformance, with alternative to have read the 4220 * sigblock word on each syscall entry. 4221 */ 4222 td->td_sigblock_val = 0; 4223 4224 /* 4225 * Rely on normal ast mechanism to deliver pending 4226 * signals to current thread. But notify others about 4227 * fake unblock. 4228 */ 4229 sigfastblock_resched(td, error == 0 && p->p_numthreads != 1); 4230 4231 break; 4232 4233 case SIGFASTBLOCK_UNSETPTR: 4234 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4235 error = EINVAL; 4236 break; 4237 } 4238 if (!sigfastblock_fetch_sig(td, false, &oldval)) { 4239 error = EFAULT; 4240 break; 4241 } 4242 if (oldval != 0 && oldval != SIGFASTBLOCK_PEND) { 4243 error = EBUSY; 4244 break; 4245 } 4246 sigfastblock_clear(td); 4247 break; 4248 4249 default: 4250 error = EINVAL; 4251 break; 4252 } 4253 return (error); 4254 } 4255 4256 void 4257 sigfastblock_clear(struct thread *td) 4258 { 4259 bool resched; 4260 4261 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4262 return; 4263 td->td_sigblock_val = 0; 4264 resched = (td->td_pflags & TDP_SIGFASTPENDING) != 0 || 4265 SIGPENDING(td); 4266 td->td_pflags &= ~(TDP_SIGFASTBLOCK | TDP_SIGFASTPENDING); 4267 sigfastblock_resched(td, resched); 4268 } 4269 4270 void 4271 sigfastblock_fetch(struct thread *td) 4272 { 4273 uint32_t val; 4274 4275 (void)sigfastblock_fetch_sig(td, true, &val); 4276 } 4277 4278 static void 4279 sigfastblock_setpend1(struct thread *td) 4280 { 4281 int res; 4282 uint32_t oldval; 4283 4284 if ((td->td_pflags & TDP_SIGFASTPENDING) == 0) 4285 return; 4286 res = fueword32((void *)td->td_sigblock_ptr, &oldval); 4287 if (res == -1) { 4288 sigfastblock_failed(td, true, false); 4289 return; 4290 } 4291 for (;;) { 4292 res = casueword32(td->td_sigblock_ptr, oldval, &oldval, 4293 oldval | SIGFASTBLOCK_PEND); 4294 if (res == -1) { 4295 sigfastblock_failed(td, true, true); 4296 return; 4297 } 4298 if (res == 0) { 4299 td->td_sigblock_val = oldval & ~SIGFASTBLOCK_FLAGS; 4300 td->td_pflags &= ~TDP_SIGFASTPENDING; 4301 break; 4302 } 4303 MPASS(res == 1); 4304 if (thread_check_susp(td, false) != 0) 4305 break; 4306 } 4307 } 4308 4309 void 4310 sigfastblock_setpend(struct thread *td, bool resched) 4311 { 4312 struct proc *p; 4313 4314 sigfastblock_setpend1(td); 4315 if (resched) { 4316 p = td->td_proc; 4317 PROC_LOCK(p); 4318 reschedule_signals(p, fastblock_mask, SIGPROCMASK_FASTBLK); 4319 PROC_UNLOCK(p); 4320 } 4321 } 4322