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 */ 217 218 static int sigproptbl[NSIG] = { 219 [SIGHUP] = SIGPROP_KILL, 220 [SIGINT] = SIGPROP_KILL, 221 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE, 222 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE, 223 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE, 224 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE, 225 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE, 226 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE, 227 [SIGKILL] = SIGPROP_KILL, 228 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE, 229 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE, 230 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE, 231 [SIGPIPE] = SIGPROP_KILL, 232 [SIGALRM] = SIGPROP_KILL, 233 [SIGTERM] = SIGPROP_KILL, 234 [SIGURG] = SIGPROP_IGNORE, 235 [SIGSTOP] = SIGPROP_STOP, 236 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP, 237 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT, 238 [SIGCHLD] = SIGPROP_IGNORE, 239 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP, 240 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP, 241 [SIGIO] = SIGPROP_IGNORE, 242 [SIGXCPU] = SIGPROP_KILL, 243 [SIGXFSZ] = SIGPROP_KILL, 244 [SIGVTALRM] = SIGPROP_KILL, 245 [SIGPROF] = SIGPROP_KILL, 246 [SIGWINCH] = SIGPROP_IGNORE, 247 [SIGINFO] = SIGPROP_IGNORE, 248 [SIGUSR1] = SIGPROP_KILL, 249 [SIGUSR2] = SIGPROP_KILL, 250 }; 251 252 #define _SIG_FOREACH_ADVANCE(i, set) ({ \ 253 int __found; \ 254 for (;;) { \ 255 if (__bits != 0) { \ 256 int __sig = ffs(__bits); \ 257 __bits &= ~(1u << (__sig - 1)); \ 258 sig = __i * sizeof((set)->__bits[0]) * NBBY + __sig; \ 259 __found = 1; \ 260 break; \ 261 } \ 262 if (++__i == _SIG_WORDS) { \ 263 __found = 0; \ 264 break; \ 265 } \ 266 __bits = (set)->__bits[__i]; \ 267 } \ 268 __found != 0; \ 269 }) 270 271 #define SIG_FOREACH(i, set) \ 272 for (int32_t __i = -1, __bits = 0; \ 273 _SIG_FOREACH_ADVANCE(i, set); ) \ 274 275 sigset_t fastblock_mask; 276 277 static void 278 sigqueue_start(void) 279 { 280 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 281 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 282 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 283 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 284 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 285 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 286 SIGFILLSET(fastblock_mask); 287 SIG_CANTMASK(fastblock_mask); 288 } 289 290 ksiginfo_t * 291 ksiginfo_alloc(int wait) 292 { 293 int flags; 294 295 flags = M_ZERO | (wait ? M_WAITOK : M_NOWAIT); 296 if (ksiginfo_zone != NULL) 297 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 298 return (NULL); 299 } 300 301 void 302 ksiginfo_free(ksiginfo_t *ksi) 303 { 304 uma_zfree(ksiginfo_zone, ksi); 305 } 306 307 static __inline int 308 ksiginfo_tryfree(ksiginfo_t *ksi) 309 { 310 if (!(ksi->ksi_flags & KSI_EXT)) { 311 uma_zfree(ksiginfo_zone, ksi); 312 return (1); 313 } 314 return (0); 315 } 316 317 void 318 sigqueue_init(sigqueue_t *list, struct proc *p) 319 { 320 SIGEMPTYSET(list->sq_signals); 321 SIGEMPTYSET(list->sq_kill); 322 SIGEMPTYSET(list->sq_ptrace); 323 TAILQ_INIT(&list->sq_list); 324 list->sq_proc = p; 325 list->sq_flags = SQ_INIT; 326 } 327 328 /* 329 * Get a signal's ksiginfo. 330 * Return: 331 * 0 - signal not found 332 * others - signal number 333 */ 334 static int 335 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 336 { 337 struct proc *p = sq->sq_proc; 338 struct ksiginfo *ksi, *next; 339 int count = 0; 340 341 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 342 343 if (!SIGISMEMBER(sq->sq_signals, signo)) 344 return (0); 345 346 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 347 count++; 348 SIGDELSET(sq->sq_ptrace, signo); 349 si->ksi_flags |= KSI_PTRACE; 350 } 351 if (SIGISMEMBER(sq->sq_kill, signo)) { 352 count++; 353 if (count == 1) 354 SIGDELSET(sq->sq_kill, signo); 355 } 356 357 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 358 if (ksi->ksi_signo == signo) { 359 if (count == 0) { 360 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 361 ksi->ksi_sigq = NULL; 362 ksiginfo_copy(ksi, si); 363 if (ksiginfo_tryfree(ksi) && p != NULL) 364 p->p_pendingcnt--; 365 } 366 if (++count > 1) 367 break; 368 } 369 } 370 371 if (count <= 1) 372 SIGDELSET(sq->sq_signals, signo); 373 si->ksi_signo = signo; 374 return (signo); 375 } 376 377 void 378 sigqueue_take(ksiginfo_t *ksi) 379 { 380 struct ksiginfo *kp; 381 struct proc *p; 382 sigqueue_t *sq; 383 384 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 385 return; 386 387 p = sq->sq_proc; 388 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 389 ksi->ksi_sigq = NULL; 390 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 391 p->p_pendingcnt--; 392 393 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 394 kp = TAILQ_NEXT(kp, ksi_link)) { 395 if (kp->ksi_signo == ksi->ksi_signo) 396 break; 397 } 398 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 399 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 400 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 401 } 402 403 static int 404 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 405 { 406 struct proc *p = sq->sq_proc; 407 struct ksiginfo *ksi; 408 int ret = 0; 409 410 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 411 412 /* 413 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 414 * for these signals. 415 */ 416 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 417 SIGADDSET(sq->sq_kill, signo); 418 goto out_set_bit; 419 } 420 421 /* directly insert the ksi, don't copy it */ 422 if (si->ksi_flags & KSI_INS) { 423 if (si->ksi_flags & KSI_HEAD) 424 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 425 else 426 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 427 si->ksi_sigq = sq; 428 goto out_set_bit; 429 } 430 431 if (__predict_false(ksiginfo_zone == NULL)) { 432 SIGADDSET(sq->sq_kill, signo); 433 goto out_set_bit; 434 } 435 436 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 437 signal_overflow++; 438 ret = EAGAIN; 439 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 440 signal_alloc_fail++; 441 ret = EAGAIN; 442 } else { 443 if (p != NULL) 444 p->p_pendingcnt++; 445 ksiginfo_copy(si, ksi); 446 ksi->ksi_signo = signo; 447 if (si->ksi_flags & KSI_HEAD) 448 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 449 else 450 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 451 ksi->ksi_sigq = sq; 452 } 453 454 if (ret != 0) { 455 if ((si->ksi_flags & KSI_PTRACE) != 0) { 456 SIGADDSET(sq->sq_ptrace, signo); 457 ret = 0; 458 goto out_set_bit; 459 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 460 (si->ksi_flags & KSI_SIGQ) == 0) { 461 SIGADDSET(sq->sq_kill, signo); 462 ret = 0; 463 goto out_set_bit; 464 } 465 return (ret); 466 } 467 468 out_set_bit: 469 SIGADDSET(sq->sq_signals, signo); 470 return (ret); 471 } 472 473 void 474 sigqueue_flush(sigqueue_t *sq) 475 { 476 struct proc *p = sq->sq_proc; 477 ksiginfo_t *ksi; 478 479 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 480 481 if (p != NULL) 482 PROC_LOCK_ASSERT(p, MA_OWNED); 483 484 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 485 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 486 ksi->ksi_sigq = NULL; 487 if (ksiginfo_tryfree(ksi) && p != NULL) 488 p->p_pendingcnt--; 489 } 490 491 SIGEMPTYSET(sq->sq_signals); 492 SIGEMPTYSET(sq->sq_kill); 493 SIGEMPTYSET(sq->sq_ptrace); 494 } 495 496 static void 497 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 498 { 499 sigset_t tmp; 500 struct proc *p1, *p2; 501 ksiginfo_t *ksi, *next; 502 503 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 504 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 505 p1 = src->sq_proc; 506 p2 = dst->sq_proc; 507 /* Move siginfo to target list */ 508 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 509 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 510 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 511 if (p1 != NULL) 512 p1->p_pendingcnt--; 513 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 514 ksi->ksi_sigq = dst; 515 if (p2 != NULL) 516 p2->p_pendingcnt++; 517 } 518 } 519 520 /* Move pending bits to target list */ 521 tmp = src->sq_kill; 522 SIGSETAND(tmp, *set); 523 SIGSETOR(dst->sq_kill, tmp); 524 SIGSETNAND(src->sq_kill, tmp); 525 526 tmp = src->sq_ptrace; 527 SIGSETAND(tmp, *set); 528 SIGSETOR(dst->sq_ptrace, tmp); 529 SIGSETNAND(src->sq_ptrace, tmp); 530 531 tmp = src->sq_signals; 532 SIGSETAND(tmp, *set); 533 SIGSETOR(dst->sq_signals, tmp); 534 SIGSETNAND(src->sq_signals, tmp); 535 } 536 537 #if 0 538 static void 539 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 540 { 541 sigset_t set; 542 543 SIGEMPTYSET(set); 544 SIGADDSET(set, signo); 545 sigqueue_move_set(src, dst, &set); 546 } 547 #endif 548 549 static void 550 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 551 { 552 struct proc *p = sq->sq_proc; 553 ksiginfo_t *ksi, *next; 554 555 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 556 557 /* Remove siginfo queue */ 558 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 559 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 560 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 561 ksi->ksi_sigq = NULL; 562 if (ksiginfo_tryfree(ksi) && p != NULL) 563 p->p_pendingcnt--; 564 } 565 } 566 SIGSETNAND(sq->sq_kill, *set); 567 SIGSETNAND(sq->sq_ptrace, *set); 568 SIGSETNAND(sq->sq_signals, *set); 569 } 570 571 void 572 sigqueue_delete(sigqueue_t *sq, int signo) 573 { 574 sigset_t set; 575 576 SIGEMPTYSET(set); 577 SIGADDSET(set, signo); 578 sigqueue_delete_set(sq, &set); 579 } 580 581 /* Remove a set of signals for a process */ 582 static void 583 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 584 { 585 sigqueue_t worklist; 586 struct thread *td0; 587 588 PROC_LOCK_ASSERT(p, MA_OWNED); 589 590 sigqueue_init(&worklist, NULL); 591 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 592 593 FOREACH_THREAD_IN_PROC(p, td0) 594 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 595 596 sigqueue_flush(&worklist); 597 } 598 599 void 600 sigqueue_delete_proc(struct proc *p, int signo) 601 { 602 sigset_t set; 603 604 SIGEMPTYSET(set); 605 SIGADDSET(set, signo); 606 sigqueue_delete_set_proc(p, &set); 607 } 608 609 static void 610 sigqueue_delete_stopmask_proc(struct proc *p) 611 { 612 sigset_t set; 613 614 SIGEMPTYSET(set); 615 SIGADDSET(set, SIGSTOP); 616 SIGADDSET(set, SIGTSTP); 617 SIGADDSET(set, SIGTTIN); 618 SIGADDSET(set, SIGTTOU); 619 sigqueue_delete_set_proc(p, &set); 620 } 621 622 /* 623 * Determine signal that should be delivered to thread td, the current 624 * thread, 0 if none. If there is a pending stop signal with default 625 * action, the process stops in issignal(). 626 */ 627 int 628 cursig(struct thread *td) 629 { 630 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 631 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 632 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 633 return (SIGPENDING(td) ? issignal(td) : 0); 634 } 635 636 /* 637 * Arrange for ast() to handle unmasked pending signals on return to user 638 * mode. This must be called whenever a signal is added to td_sigqueue or 639 * unmasked in td_sigmask. 640 */ 641 void 642 signotify(struct thread *td) 643 { 644 645 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 646 647 if (SIGPENDING(td)) { 648 thread_lock(td); 649 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 650 thread_unlock(td); 651 } 652 } 653 654 /* 655 * Returns 1 (true) if altstack is configured for the thread, and the 656 * passed stack bottom address falls into the altstack range. Handles 657 * the 43 compat special case where the alt stack size is zero. 658 */ 659 int 660 sigonstack(size_t sp) 661 { 662 struct thread *td; 663 664 td = curthread; 665 if ((td->td_pflags & TDP_ALTSTACK) == 0) 666 return (0); 667 #if defined(COMPAT_43) 668 if (SV_PROC_FLAG(td->td_proc, SV_AOUT) && td->td_sigstk.ss_size == 0) 669 return ((td->td_sigstk.ss_flags & SS_ONSTACK) != 0); 670 #endif 671 return (sp >= (size_t)td->td_sigstk.ss_sp && 672 sp < td->td_sigstk.ss_size + (size_t)td->td_sigstk.ss_sp); 673 } 674 675 static __inline int 676 sigprop(int sig) 677 { 678 679 if (sig > 0 && sig < nitems(sigproptbl)) 680 return (sigproptbl[sig]); 681 return (0); 682 } 683 684 static bool 685 sigact_flag_test(const struct sigaction *act, int flag) 686 { 687 688 /* 689 * SA_SIGINFO is reset when signal disposition is set to 690 * ignore or default. Other flags are kept according to user 691 * settings. 692 */ 693 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 694 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 695 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 696 } 697 698 /* 699 * kern_sigaction 700 * sigaction 701 * freebsd4_sigaction 702 * osigaction 703 */ 704 int 705 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 706 struct sigaction *oact, int flags) 707 { 708 struct sigacts *ps; 709 struct proc *p = td->td_proc; 710 711 if (!_SIG_VALID(sig)) 712 return (EINVAL); 713 if (act != NULL && act->sa_handler != SIG_DFL && 714 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 715 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 716 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 717 return (EINVAL); 718 719 PROC_LOCK(p); 720 ps = p->p_sigacts; 721 mtx_lock(&ps->ps_mtx); 722 if (oact) { 723 memset(oact, 0, sizeof(*oact)); 724 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 725 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 726 oact->sa_flags |= SA_ONSTACK; 727 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 728 oact->sa_flags |= SA_RESTART; 729 if (SIGISMEMBER(ps->ps_sigreset, sig)) 730 oact->sa_flags |= SA_RESETHAND; 731 if (SIGISMEMBER(ps->ps_signodefer, sig)) 732 oact->sa_flags |= SA_NODEFER; 733 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 734 oact->sa_flags |= SA_SIGINFO; 735 oact->sa_sigaction = 736 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 737 } else 738 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 739 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 740 oact->sa_flags |= SA_NOCLDSTOP; 741 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 742 oact->sa_flags |= SA_NOCLDWAIT; 743 } 744 if (act) { 745 if ((sig == SIGKILL || sig == SIGSTOP) && 746 act->sa_handler != SIG_DFL) { 747 mtx_unlock(&ps->ps_mtx); 748 PROC_UNLOCK(p); 749 return (EINVAL); 750 } 751 752 /* 753 * Change setting atomically. 754 */ 755 756 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 757 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 758 if (sigact_flag_test(act, SA_SIGINFO)) { 759 ps->ps_sigact[_SIG_IDX(sig)] = 760 (__sighandler_t *)act->sa_sigaction; 761 SIGADDSET(ps->ps_siginfo, sig); 762 } else { 763 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 764 SIGDELSET(ps->ps_siginfo, sig); 765 } 766 if (!sigact_flag_test(act, SA_RESTART)) 767 SIGADDSET(ps->ps_sigintr, sig); 768 else 769 SIGDELSET(ps->ps_sigintr, sig); 770 if (sigact_flag_test(act, SA_ONSTACK)) 771 SIGADDSET(ps->ps_sigonstack, sig); 772 else 773 SIGDELSET(ps->ps_sigonstack, sig); 774 if (sigact_flag_test(act, SA_RESETHAND)) 775 SIGADDSET(ps->ps_sigreset, sig); 776 else 777 SIGDELSET(ps->ps_sigreset, sig); 778 if (sigact_flag_test(act, SA_NODEFER)) 779 SIGADDSET(ps->ps_signodefer, sig); 780 else 781 SIGDELSET(ps->ps_signodefer, sig); 782 if (sig == SIGCHLD) { 783 if (act->sa_flags & SA_NOCLDSTOP) 784 ps->ps_flag |= PS_NOCLDSTOP; 785 else 786 ps->ps_flag &= ~PS_NOCLDSTOP; 787 if (act->sa_flags & SA_NOCLDWAIT) { 788 /* 789 * Paranoia: since SA_NOCLDWAIT is implemented 790 * by reparenting the dying child to PID 1 (and 791 * trust it to reap the zombie), PID 1 itself 792 * is forbidden to set SA_NOCLDWAIT. 793 */ 794 if (p->p_pid == 1) 795 ps->ps_flag &= ~PS_NOCLDWAIT; 796 else 797 ps->ps_flag |= PS_NOCLDWAIT; 798 } else 799 ps->ps_flag &= ~PS_NOCLDWAIT; 800 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 801 ps->ps_flag |= PS_CLDSIGIGN; 802 else 803 ps->ps_flag &= ~PS_CLDSIGIGN; 804 } 805 /* 806 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 807 * and for signals set to SIG_DFL where the default is to 808 * ignore. However, don't put SIGCONT in ps_sigignore, as we 809 * have to restart the process. 810 */ 811 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 812 (sigprop(sig) & SIGPROP_IGNORE && 813 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 814 /* never to be seen again */ 815 sigqueue_delete_proc(p, sig); 816 if (sig != SIGCONT) 817 /* easier in psignal */ 818 SIGADDSET(ps->ps_sigignore, sig); 819 SIGDELSET(ps->ps_sigcatch, sig); 820 } else { 821 SIGDELSET(ps->ps_sigignore, sig); 822 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 823 SIGDELSET(ps->ps_sigcatch, sig); 824 else 825 SIGADDSET(ps->ps_sigcatch, sig); 826 } 827 #ifdef COMPAT_FREEBSD4 828 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 829 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 830 (flags & KSA_FREEBSD4) == 0) 831 SIGDELSET(ps->ps_freebsd4, sig); 832 else 833 SIGADDSET(ps->ps_freebsd4, sig); 834 #endif 835 #ifdef COMPAT_43 836 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 837 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 838 (flags & KSA_OSIGSET) == 0) 839 SIGDELSET(ps->ps_osigset, sig); 840 else 841 SIGADDSET(ps->ps_osigset, sig); 842 #endif 843 } 844 mtx_unlock(&ps->ps_mtx); 845 PROC_UNLOCK(p); 846 return (0); 847 } 848 849 #ifndef _SYS_SYSPROTO_H_ 850 struct sigaction_args { 851 int sig; 852 struct sigaction *act; 853 struct sigaction *oact; 854 }; 855 #endif 856 int 857 sys_sigaction(struct thread *td, struct sigaction_args *uap) 858 { 859 struct sigaction act, oact; 860 struct sigaction *actp, *oactp; 861 int error; 862 863 actp = (uap->act != NULL) ? &act : NULL; 864 oactp = (uap->oact != NULL) ? &oact : NULL; 865 if (actp) { 866 error = copyin(uap->act, actp, sizeof(act)); 867 if (error) 868 return (error); 869 } 870 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 871 if (oactp && !error) 872 error = copyout(oactp, uap->oact, sizeof(oact)); 873 return (error); 874 } 875 876 #ifdef COMPAT_FREEBSD4 877 #ifndef _SYS_SYSPROTO_H_ 878 struct freebsd4_sigaction_args { 879 int sig; 880 struct sigaction *act; 881 struct sigaction *oact; 882 }; 883 #endif 884 int 885 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 886 { 887 struct sigaction act, oact; 888 struct sigaction *actp, *oactp; 889 int error; 890 891 actp = (uap->act != NULL) ? &act : NULL; 892 oactp = (uap->oact != NULL) ? &oact : NULL; 893 if (actp) { 894 error = copyin(uap->act, actp, sizeof(act)); 895 if (error) 896 return (error); 897 } 898 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 899 if (oactp && !error) 900 error = copyout(oactp, uap->oact, sizeof(oact)); 901 return (error); 902 } 903 #endif /* COMAPT_FREEBSD4 */ 904 905 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 906 #ifndef _SYS_SYSPROTO_H_ 907 struct osigaction_args { 908 int signum; 909 struct osigaction *nsa; 910 struct osigaction *osa; 911 }; 912 #endif 913 int 914 osigaction(struct thread *td, struct osigaction_args *uap) 915 { 916 struct osigaction sa; 917 struct sigaction nsa, osa; 918 struct sigaction *nsap, *osap; 919 int error; 920 921 if (uap->signum <= 0 || uap->signum >= ONSIG) 922 return (EINVAL); 923 924 nsap = (uap->nsa != NULL) ? &nsa : NULL; 925 osap = (uap->osa != NULL) ? &osa : NULL; 926 927 if (nsap) { 928 error = copyin(uap->nsa, &sa, sizeof(sa)); 929 if (error) 930 return (error); 931 nsap->sa_handler = sa.sa_handler; 932 nsap->sa_flags = sa.sa_flags; 933 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 934 } 935 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 936 if (osap && !error) { 937 sa.sa_handler = osap->sa_handler; 938 sa.sa_flags = osap->sa_flags; 939 SIG2OSIG(osap->sa_mask, sa.sa_mask); 940 error = copyout(&sa, uap->osa, sizeof(sa)); 941 } 942 return (error); 943 } 944 945 #if !defined(__i386__) 946 /* Avoid replicating the same stub everywhere */ 947 int 948 osigreturn(struct thread *td, struct osigreturn_args *uap) 949 { 950 951 return (nosys(td, (struct nosys_args *)uap)); 952 } 953 #endif 954 #endif /* COMPAT_43 */ 955 956 /* 957 * Initialize signal state for process 0; 958 * set to ignore signals that are ignored by default. 959 */ 960 void 961 siginit(struct proc *p) 962 { 963 int i; 964 struct sigacts *ps; 965 966 PROC_LOCK(p); 967 ps = p->p_sigacts; 968 mtx_lock(&ps->ps_mtx); 969 for (i = 1; i <= NSIG; i++) { 970 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 971 SIGADDSET(ps->ps_sigignore, i); 972 } 973 } 974 mtx_unlock(&ps->ps_mtx); 975 PROC_UNLOCK(p); 976 } 977 978 /* 979 * Reset specified signal to the default disposition. 980 */ 981 static void 982 sigdflt(struct sigacts *ps, int sig) 983 { 984 985 mtx_assert(&ps->ps_mtx, MA_OWNED); 986 SIGDELSET(ps->ps_sigcatch, sig); 987 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 988 SIGADDSET(ps->ps_sigignore, sig); 989 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 990 SIGDELSET(ps->ps_siginfo, sig); 991 } 992 993 /* 994 * Reset signals for an exec of the specified process. 995 */ 996 void 997 execsigs(struct proc *p) 998 { 999 struct sigacts *ps; 1000 struct thread *td; 1001 1002 /* 1003 * Reset caught signals. Held signals remain held 1004 * through td_sigmask (unless they were caught, 1005 * and are now ignored by default). 1006 */ 1007 PROC_LOCK_ASSERT(p, MA_OWNED); 1008 ps = p->p_sigacts; 1009 mtx_lock(&ps->ps_mtx); 1010 sig_drop_caught(p); 1011 1012 /* 1013 * Reset stack state to the user stack. 1014 * Clear set of signals caught on the signal stack. 1015 */ 1016 td = curthread; 1017 MPASS(td->td_proc == p); 1018 td->td_sigstk.ss_flags = SS_DISABLE; 1019 td->td_sigstk.ss_size = 0; 1020 td->td_sigstk.ss_sp = 0; 1021 td->td_pflags &= ~TDP_ALTSTACK; 1022 /* 1023 * Reset no zombies if child dies flag as Solaris does. 1024 */ 1025 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1026 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1027 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1028 mtx_unlock(&ps->ps_mtx); 1029 } 1030 1031 /* 1032 * kern_sigprocmask() 1033 * 1034 * Manipulate signal mask. 1035 */ 1036 int 1037 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1038 int flags) 1039 { 1040 sigset_t new_block, oset1; 1041 struct proc *p; 1042 int error; 1043 1044 p = td->td_proc; 1045 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1046 PROC_LOCK_ASSERT(p, MA_OWNED); 1047 else 1048 PROC_LOCK(p); 1049 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1050 ? MA_OWNED : MA_NOTOWNED); 1051 if (oset != NULL) 1052 *oset = td->td_sigmask; 1053 1054 error = 0; 1055 if (set != NULL) { 1056 switch (how) { 1057 case SIG_BLOCK: 1058 SIG_CANTMASK(*set); 1059 oset1 = td->td_sigmask; 1060 SIGSETOR(td->td_sigmask, *set); 1061 new_block = td->td_sigmask; 1062 SIGSETNAND(new_block, oset1); 1063 break; 1064 case SIG_UNBLOCK: 1065 SIGSETNAND(td->td_sigmask, *set); 1066 signotify(td); 1067 goto out; 1068 case SIG_SETMASK: 1069 SIG_CANTMASK(*set); 1070 oset1 = td->td_sigmask; 1071 if (flags & SIGPROCMASK_OLD) 1072 SIGSETLO(td->td_sigmask, *set); 1073 else 1074 td->td_sigmask = *set; 1075 new_block = td->td_sigmask; 1076 SIGSETNAND(new_block, oset1); 1077 signotify(td); 1078 break; 1079 default: 1080 error = EINVAL; 1081 goto out; 1082 } 1083 1084 /* 1085 * The new_block set contains signals that were not previously 1086 * blocked, but are blocked now. 1087 * 1088 * In case we block any signal that was not previously blocked 1089 * for td, and process has the signal pending, try to schedule 1090 * signal delivery to some thread that does not block the 1091 * signal, possibly waking it up. 1092 */ 1093 if (p->p_numthreads != 1) 1094 reschedule_signals(p, new_block, flags); 1095 } 1096 1097 out: 1098 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1099 PROC_UNLOCK(p); 1100 return (error); 1101 } 1102 1103 #ifndef _SYS_SYSPROTO_H_ 1104 struct sigprocmask_args { 1105 int how; 1106 const sigset_t *set; 1107 sigset_t *oset; 1108 }; 1109 #endif 1110 int 1111 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1112 { 1113 sigset_t set, oset; 1114 sigset_t *setp, *osetp; 1115 int error; 1116 1117 setp = (uap->set != NULL) ? &set : NULL; 1118 osetp = (uap->oset != NULL) ? &oset : NULL; 1119 if (setp) { 1120 error = copyin(uap->set, setp, sizeof(set)); 1121 if (error) 1122 return (error); 1123 } 1124 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1125 if (osetp && !error) { 1126 error = copyout(osetp, uap->oset, sizeof(oset)); 1127 } 1128 return (error); 1129 } 1130 1131 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1132 #ifndef _SYS_SYSPROTO_H_ 1133 struct osigprocmask_args { 1134 int how; 1135 osigset_t mask; 1136 }; 1137 #endif 1138 int 1139 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1140 { 1141 sigset_t set, oset; 1142 int error; 1143 1144 OSIG2SIG(uap->mask, set); 1145 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1146 SIG2OSIG(oset, td->td_retval[0]); 1147 return (error); 1148 } 1149 #endif /* COMPAT_43 */ 1150 1151 int 1152 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1153 { 1154 ksiginfo_t ksi; 1155 sigset_t set; 1156 int error; 1157 1158 error = copyin(uap->set, &set, sizeof(set)); 1159 if (error) { 1160 td->td_retval[0] = error; 1161 return (0); 1162 } 1163 1164 error = kern_sigtimedwait(td, set, &ksi, NULL); 1165 if (error) { 1166 /* 1167 * sigwait() function shall not return EINTR, but 1168 * the syscall does. Non-ancient libc provides the 1169 * wrapper which hides EINTR. Otherwise, EINTR return 1170 * is used by libthr to handle required cancellation 1171 * point in the sigwait(). 1172 */ 1173 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1174 return (ERESTART); 1175 td->td_retval[0] = error; 1176 return (0); 1177 } 1178 1179 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1180 td->td_retval[0] = error; 1181 return (0); 1182 } 1183 1184 int 1185 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1186 { 1187 struct timespec ts; 1188 struct timespec *timeout; 1189 sigset_t set; 1190 ksiginfo_t ksi; 1191 int error; 1192 1193 if (uap->timeout) { 1194 error = copyin(uap->timeout, &ts, sizeof(ts)); 1195 if (error) 1196 return (error); 1197 1198 timeout = &ts; 1199 } else 1200 timeout = NULL; 1201 1202 error = copyin(uap->set, &set, sizeof(set)); 1203 if (error) 1204 return (error); 1205 1206 error = kern_sigtimedwait(td, set, &ksi, timeout); 1207 if (error) 1208 return (error); 1209 1210 if (uap->info) 1211 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1212 1213 if (error == 0) 1214 td->td_retval[0] = ksi.ksi_signo; 1215 return (error); 1216 } 1217 1218 int 1219 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1220 { 1221 ksiginfo_t ksi; 1222 sigset_t set; 1223 int error; 1224 1225 error = copyin(uap->set, &set, sizeof(set)); 1226 if (error) 1227 return (error); 1228 1229 error = kern_sigtimedwait(td, set, &ksi, NULL); 1230 if (error) 1231 return (error); 1232 1233 if (uap->info) 1234 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1235 1236 if (error == 0) 1237 td->td_retval[0] = ksi.ksi_signo; 1238 return (error); 1239 } 1240 1241 static void 1242 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1243 { 1244 struct thread *thr; 1245 1246 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1247 if (thr == td) 1248 thr->td_si = *si; 1249 else 1250 thr->td_si.si_signo = 0; 1251 } 1252 } 1253 1254 int 1255 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1256 struct timespec *timeout) 1257 { 1258 struct sigacts *ps; 1259 sigset_t saved_mask, new_block; 1260 struct proc *p; 1261 int error, sig, timo, timevalid = 0; 1262 struct timespec rts, ets, ts; 1263 struct timeval tv; 1264 bool traced; 1265 1266 p = td->td_proc; 1267 error = 0; 1268 ets.tv_sec = 0; 1269 ets.tv_nsec = 0; 1270 traced = false; 1271 1272 /* Ensure the sigfastblock value is up to date. */ 1273 sigfastblock_fetch(td); 1274 1275 if (timeout != NULL) { 1276 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1277 timevalid = 1; 1278 getnanouptime(&rts); 1279 timespecadd(&rts, timeout, &ets); 1280 } 1281 } 1282 ksiginfo_init(ksi); 1283 /* Some signals can not be waited for. */ 1284 SIG_CANTMASK(waitset); 1285 ps = p->p_sigacts; 1286 PROC_LOCK(p); 1287 saved_mask = td->td_sigmask; 1288 SIGSETNAND(td->td_sigmask, waitset); 1289 if ((p->p_sysent->sv_flags & SV_SIG_DISCIGN) != 0 || 1290 !kern_sig_discard_ign) { 1291 thread_lock(td); 1292 td->td_flags |= TDF_SIGWAIT; 1293 thread_unlock(td); 1294 } 1295 for (;;) { 1296 mtx_lock(&ps->ps_mtx); 1297 sig = cursig(td); 1298 mtx_unlock(&ps->ps_mtx); 1299 KASSERT(sig >= 0, ("sig %d", sig)); 1300 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1301 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1302 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1303 error = 0; 1304 break; 1305 } 1306 } 1307 1308 if (error != 0) 1309 break; 1310 1311 /* 1312 * POSIX says this must be checked after looking for pending 1313 * signals. 1314 */ 1315 if (timeout != NULL) { 1316 if (!timevalid) { 1317 error = EINVAL; 1318 break; 1319 } 1320 getnanouptime(&rts); 1321 if (timespeccmp(&rts, &ets, >=)) { 1322 error = EAGAIN; 1323 break; 1324 } 1325 timespecsub(&ets, &rts, &ts); 1326 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1327 timo = tvtohz(&tv); 1328 } else { 1329 timo = 0; 1330 } 1331 1332 if (traced) { 1333 error = EINTR; 1334 break; 1335 } 1336 1337 error = msleep(&p->p_sigacts, &p->p_mtx, PPAUSE | PCATCH, 1338 "sigwait", timo); 1339 1340 /* The syscalls can not be restarted. */ 1341 if (error == ERESTART) 1342 error = EINTR; 1343 1344 /* We will calculate timeout by ourself. */ 1345 if (timeout != NULL && error == EAGAIN) 1346 error = 0; 1347 1348 /* 1349 * If PTRACE_SCE or PTRACE_SCX were set after 1350 * userspace entered the syscall, return spurious 1351 * EINTR after wait was done. Only do this as last 1352 * resort after rechecking for possible queued signals 1353 * and expired timeouts. 1354 */ 1355 if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0) 1356 traced = true; 1357 } 1358 thread_lock(td); 1359 td->td_flags &= ~TDF_SIGWAIT; 1360 thread_unlock(td); 1361 1362 new_block = saved_mask; 1363 SIGSETNAND(new_block, td->td_sigmask); 1364 td->td_sigmask = saved_mask; 1365 /* 1366 * Fewer signals can be delivered to us, reschedule signal 1367 * notification. 1368 */ 1369 if (p->p_numthreads != 1) 1370 reschedule_signals(p, new_block, 0); 1371 1372 if (error == 0) { 1373 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1374 1375 if (ksi->ksi_code == SI_TIMER) 1376 itimer_accept(p, ksi->ksi_timerid, ksi); 1377 1378 #ifdef KTRACE 1379 if (KTRPOINT(td, KTR_PSIG)) { 1380 sig_t action; 1381 1382 mtx_lock(&ps->ps_mtx); 1383 action = ps->ps_sigact[_SIG_IDX(sig)]; 1384 mtx_unlock(&ps->ps_mtx); 1385 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1386 } 1387 #endif 1388 if (sig == SIGKILL) { 1389 proc_td_siginfo_capture(td, &ksi->ksi_info); 1390 sigexit(td, sig); 1391 } 1392 } 1393 PROC_UNLOCK(p); 1394 return (error); 1395 } 1396 1397 #ifndef _SYS_SYSPROTO_H_ 1398 struct sigpending_args { 1399 sigset_t *set; 1400 }; 1401 #endif 1402 int 1403 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1404 { 1405 struct proc *p = td->td_proc; 1406 sigset_t pending; 1407 1408 PROC_LOCK(p); 1409 pending = p->p_sigqueue.sq_signals; 1410 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1411 PROC_UNLOCK(p); 1412 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1413 } 1414 1415 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1416 #ifndef _SYS_SYSPROTO_H_ 1417 struct osigpending_args { 1418 int dummy; 1419 }; 1420 #endif 1421 int 1422 osigpending(struct thread *td, struct osigpending_args *uap) 1423 { 1424 struct proc *p = td->td_proc; 1425 sigset_t pending; 1426 1427 PROC_LOCK(p); 1428 pending = p->p_sigqueue.sq_signals; 1429 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1430 PROC_UNLOCK(p); 1431 SIG2OSIG(pending, td->td_retval[0]); 1432 return (0); 1433 } 1434 #endif /* COMPAT_43 */ 1435 1436 #if defined(COMPAT_43) 1437 /* 1438 * Generalized interface signal handler, 4.3-compatible. 1439 */ 1440 #ifndef _SYS_SYSPROTO_H_ 1441 struct osigvec_args { 1442 int signum; 1443 struct sigvec *nsv; 1444 struct sigvec *osv; 1445 }; 1446 #endif 1447 /* ARGSUSED */ 1448 int 1449 osigvec(struct thread *td, struct osigvec_args *uap) 1450 { 1451 struct sigvec vec; 1452 struct sigaction nsa, osa; 1453 struct sigaction *nsap, *osap; 1454 int error; 1455 1456 if (uap->signum <= 0 || uap->signum >= ONSIG) 1457 return (EINVAL); 1458 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1459 osap = (uap->osv != NULL) ? &osa : NULL; 1460 if (nsap) { 1461 error = copyin(uap->nsv, &vec, sizeof(vec)); 1462 if (error) 1463 return (error); 1464 nsap->sa_handler = vec.sv_handler; 1465 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1466 nsap->sa_flags = vec.sv_flags; 1467 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1468 } 1469 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1470 if (osap && !error) { 1471 vec.sv_handler = osap->sa_handler; 1472 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1473 vec.sv_flags = osap->sa_flags; 1474 vec.sv_flags &= ~SA_NOCLDWAIT; 1475 vec.sv_flags ^= SA_RESTART; 1476 error = copyout(&vec, uap->osv, sizeof(vec)); 1477 } 1478 return (error); 1479 } 1480 1481 #ifndef _SYS_SYSPROTO_H_ 1482 struct osigblock_args { 1483 int mask; 1484 }; 1485 #endif 1486 int 1487 osigblock(struct thread *td, struct osigblock_args *uap) 1488 { 1489 sigset_t set, oset; 1490 1491 OSIG2SIG(uap->mask, set); 1492 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1493 SIG2OSIG(oset, td->td_retval[0]); 1494 return (0); 1495 } 1496 1497 #ifndef _SYS_SYSPROTO_H_ 1498 struct osigsetmask_args { 1499 int mask; 1500 }; 1501 #endif 1502 int 1503 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1504 { 1505 sigset_t set, oset; 1506 1507 OSIG2SIG(uap->mask, set); 1508 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1509 SIG2OSIG(oset, td->td_retval[0]); 1510 return (0); 1511 } 1512 #endif /* COMPAT_43 */ 1513 1514 /* 1515 * Suspend calling thread until signal, providing mask to be set in the 1516 * meantime. 1517 */ 1518 #ifndef _SYS_SYSPROTO_H_ 1519 struct sigsuspend_args { 1520 const sigset_t *sigmask; 1521 }; 1522 #endif 1523 /* ARGSUSED */ 1524 int 1525 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1526 { 1527 sigset_t mask; 1528 int error; 1529 1530 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1531 if (error) 1532 return (error); 1533 return (kern_sigsuspend(td, mask)); 1534 } 1535 1536 int 1537 kern_sigsuspend(struct thread *td, sigset_t mask) 1538 { 1539 struct proc *p = td->td_proc; 1540 int has_sig, sig; 1541 1542 /* Ensure the sigfastblock value is up to date. */ 1543 sigfastblock_fetch(td); 1544 1545 /* 1546 * When returning from sigsuspend, we want 1547 * the old mask to be restored after the 1548 * signal handler has finished. Thus, we 1549 * save it here and mark the sigacts structure 1550 * to indicate this. 1551 */ 1552 PROC_LOCK(p); 1553 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1554 SIGPROCMASK_PROC_LOCKED); 1555 td->td_pflags |= TDP_OLDMASK; 1556 1557 /* 1558 * Process signals now. Otherwise, we can get spurious wakeup 1559 * due to signal entered process queue, but delivered to other 1560 * thread. But sigsuspend should return only on signal 1561 * delivery. 1562 */ 1563 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1564 for (has_sig = 0; !has_sig;) { 1565 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1566 0) == 0) 1567 /* void */; 1568 thread_suspend_check(0); 1569 mtx_lock(&p->p_sigacts->ps_mtx); 1570 while ((sig = cursig(td)) != 0) { 1571 KASSERT(sig >= 0, ("sig %d", sig)); 1572 has_sig += postsig(sig); 1573 } 1574 mtx_unlock(&p->p_sigacts->ps_mtx); 1575 1576 /* 1577 * If PTRACE_SCE or PTRACE_SCX were set after 1578 * userspace entered the syscall, return spurious 1579 * EINTR. 1580 */ 1581 if ((p->p_ptevents & PTRACE_SYSCALL) != 0) 1582 has_sig += 1; 1583 } 1584 PROC_UNLOCK(p); 1585 td->td_errno = EINTR; 1586 td->td_pflags |= TDP_NERRNO; 1587 return (EJUSTRETURN); 1588 } 1589 1590 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1591 /* 1592 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1593 * convention: libc stub passes mask, not pointer, to save a copyin. 1594 */ 1595 #ifndef _SYS_SYSPROTO_H_ 1596 struct osigsuspend_args { 1597 osigset_t mask; 1598 }; 1599 #endif 1600 /* ARGSUSED */ 1601 int 1602 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1603 { 1604 sigset_t mask; 1605 1606 OSIG2SIG(uap->mask, mask); 1607 return (kern_sigsuspend(td, mask)); 1608 } 1609 #endif /* COMPAT_43 */ 1610 1611 #if defined(COMPAT_43) 1612 #ifndef _SYS_SYSPROTO_H_ 1613 struct osigstack_args { 1614 struct sigstack *nss; 1615 struct sigstack *oss; 1616 }; 1617 #endif 1618 /* ARGSUSED */ 1619 int 1620 osigstack(struct thread *td, struct osigstack_args *uap) 1621 { 1622 struct sigstack nss, oss; 1623 int error = 0; 1624 1625 if (uap->nss != NULL) { 1626 error = copyin(uap->nss, &nss, sizeof(nss)); 1627 if (error) 1628 return (error); 1629 } 1630 oss.ss_sp = td->td_sigstk.ss_sp; 1631 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1632 if (uap->nss != NULL) { 1633 td->td_sigstk.ss_sp = nss.ss_sp; 1634 td->td_sigstk.ss_size = 0; 1635 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1636 td->td_pflags |= TDP_ALTSTACK; 1637 } 1638 if (uap->oss != NULL) 1639 error = copyout(&oss, uap->oss, sizeof(oss)); 1640 1641 return (error); 1642 } 1643 #endif /* COMPAT_43 */ 1644 1645 #ifndef _SYS_SYSPROTO_H_ 1646 struct sigaltstack_args { 1647 stack_t *ss; 1648 stack_t *oss; 1649 }; 1650 #endif 1651 /* ARGSUSED */ 1652 int 1653 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1654 { 1655 stack_t ss, oss; 1656 int error; 1657 1658 if (uap->ss != NULL) { 1659 error = copyin(uap->ss, &ss, sizeof(ss)); 1660 if (error) 1661 return (error); 1662 } 1663 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1664 (uap->oss != NULL) ? &oss : NULL); 1665 if (error) 1666 return (error); 1667 if (uap->oss != NULL) 1668 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1669 return (error); 1670 } 1671 1672 int 1673 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1674 { 1675 struct proc *p = td->td_proc; 1676 int oonstack; 1677 1678 oonstack = sigonstack(cpu_getstack(td)); 1679 1680 if (oss != NULL) { 1681 *oss = td->td_sigstk; 1682 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1683 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1684 } 1685 1686 if (ss != NULL) { 1687 if (oonstack) 1688 return (EPERM); 1689 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1690 return (EINVAL); 1691 if (!(ss->ss_flags & SS_DISABLE)) { 1692 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1693 return (ENOMEM); 1694 1695 td->td_sigstk = *ss; 1696 td->td_pflags |= TDP_ALTSTACK; 1697 } else { 1698 td->td_pflags &= ~TDP_ALTSTACK; 1699 } 1700 } 1701 return (0); 1702 } 1703 1704 struct killpg1_ctx { 1705 struct thread *td; 1706 ksiginfo_t *ksi; 1707 int sig; 1708 bool sent; 1709 bool found; 1710 int ret; 1711 }; 1712 1713 static void 1714 killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg) 1715 { 1716 int err; 1717 1718 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 || 1719 (notself && p == arg->td->td_proc) || p->p_state == PRS_NEW) 1720 return; 1721 PROC_LOCK(p); 1722 err = p_cansignal(arg->td, p, arg->sig); 1723 if (err == 0 && arg->sig != 0) 1724 pksignal(p, arg->sig, arg->ksi); 1725 PROC_UNLOCK(p); 1726 if (err != ESRCH) 1727 arg->found = true; 1728 if (err == 0) 1729 arg->sent = true; 1730 else if (arg->ret == 0 && err != ESRCH && err != EPERM) 1731 arg->ret = err; 1732 } 1733 1734 /* 1735 * Common code for kill process group/broadcast kill. 1736 * cp is calling process. 1737 */ 1738 static int 1739 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1740 { 1741 struct proc *p; 1742 struct pgrp *pgrp; 1743 struct killpg1_ctx arg; 1744 1745 arg.td = td; 1746 arg.ksi = ksi; 1747 arg.sig = sig; 1748 arg.sent = false; 1749 arg.found = false; 1750 arg.ret = 0; 1751 if (all) { 1752 /* 1753 * broadcast 1754 */ 1755 sx_slock(&allproc_lock); 1756 FOREACH_PROC_IN_SYSTEM(p) { 1757 killpg1_sendsig(p, true, &arg); 1758 } 1759 sx_sunlock(&allproc_lock); 1760 } else { 1761 sx_slock(&proctree_lock); 1762 if (pgid == 0) { 1763 /* 1764 * zero pgid means send to my process group. 1765 */ 1766 pgrp = td->td_proc->p_pgrp; 1767 PGRP_LOCK(pgrp); 1768 } else { 1769 pgrp = pgfind(pgid); 1770 if (pgrp == NULL) { 1771 sx_sunlock(&proctree_lock); 1772 return (ESRCH); 1773 } 1774 } 1775 sx_sunlock(&proctree_lock); 1776 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1777 killpg1_sendsig(p, false, &arg); 1778 } 1779 PGRP_UNLOCK(pgrp); 1780 } 1781 MPASS(arg.ret != 0 || arg.found || !arg.sent); 1782 if (arg.ret == 0 && !arg.sent) 1783 arg.ret = arg.found ? EPERM : ESRCH; 1784 return (arg.ret); 1785 } 1786 1787 #ifndef _SYS_SYSPROTO_H_ 1788 struct kill_args { 1789 int pid; 1790 int signum; 1791 }; 1792 #endif 1793 /* ARGSUSED */ 1794 int 1795 sys_kill(struct thread *td, struct kill_args *uap) 1796 { 1797 1798 return (kern_kill(td, uap->pid, uap->signum)); 1799 } 1800 1801 int 1802 kern_kill(struct thread *td, pid_t pid, int signum) 1803 { 1804 ksiginfo_t ksi; 1805 struct proc *p; 1806 int error; 1807 1808 /* 1809 * A process in capability mode can send signals only to himself. 1810 * The main rationale behind this is that abort(3) is implemented as 1811 * kill(getpid(), SIGABRT). 1812 */ 1813 if (IN_CAPABILITY_MODE(td) && pid != td->td_proc->p_pid) 1814 return (ECAPMODE); 1815 1816 AUDIT_ARG_SIGNUM(signum); 1817 AUDIT_ARG_PID(pid); 1818 if ((u_int)signum > _SIG_MAXSIG) 1819 return (EINVAL); 1820 1821 ksiginfo_init(&ksi); 1822 ksi.ksi_signo = signum; 1823 ksi.ksi_code = SI_USER; 1824 ksi.ksi_pid = td->td_proc->p_pid; 1825 ksi.ksi_uid = td->td_ucred->cr_ruid; 1826 1827 if (pid > 0) { 1828 /* kill single process */ 1829 if ((p = pfind_any(pid)) == NULL) 1830 return (ESRCH); 1831 AUDIT_ARG_PROCESS(p); 1832 error = p_cansignal(td, p, signum); 1833 if (error == 0 && signum) 1834 pksignal(p, signum, &ksi); 1835 PROC_UNLOCK(p); 1836 return (error); 1837 } 1838 switch (pid) { 1839 case -1: /* broadcast signal */ 1840 return (killpg1(td, signum, 0, 1, &ksi)); 1841 case 0: /* signal own process group */ 1842 return (killpg1(td, signum, 0, 0, &ksi)); 1843 default: /* negative explicit process group */ 1844 return (killpg1(td, signum, -pid, 0, &ksi)); 1845 } 1846 /* NOTREACHED */ 1847 } 1848 1849 int 1850 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1851 { 1852 struct proc *p; 1853 int error; 1854 1855 AUDIT_ARG_SIGNUM(uap->signum); 1856 AUDIT_ARG_FD(uap->fd); 1857 if ((u_int)uap->signum > _SIG_MAXSIG) 1858 return (EINVAL); 1859 1860 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1861 if (error) 1862 return (error); 1863 AUDIT_ARG_PROCESS(p); 1864 error = p_cansignal(td, p, uap->signum); 1865 if (error == 0 && uap->signum) 1866 kern_psignal(p, uap->signum); 1867 PROC_UNLOCK(p); 1868 return (error); 1869 } 1870 1871 #if defined(COMPAT_43) 1872 #ifndef _SYS_SYSPROTO_H_ 1873 struct okillpg_args { 1874 int pgid; 1875 int signum; 1876 }; 1877 #endif 1878 /* ARGSUSED */ 1879 int 1880 okillpg(struct thread *td, struct okillpg_args *uap) 1881 { 1882 ksiginfo_t ksi; 1883 1884 AUDIT_ARG_SIGNUM(uap->signum); 1885 AUDIT_ARG_PID(uap->pgid); 1886 if ((u_int)uap->signum > _SIG_MAXSIG) 1887 return (EINVAL); 1888 1889 ksiginfo_init(&ksi); 1890 ksi.ksi_signo = uap->signum; 1891 ksi.ksi_code = SI_USER; 1892 ksi.ksi_pid = td->td_proc->p_pid; 1893 ksi.ksi_uid = td->td_ucred->cr_ruid; 1894 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1895 } 1896 #endif /* COMPAT_43 */ 1897 1898 #ifndef _SYS_SYSPROTO_H_ 1899 struct sigqueue_args { 1900 pid_t pid; 1901 int signum; 1902 /* union sigval */ void *value; 1903 }; 1904 #endif 1905 int 1906 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1907 { 1908 union sigval sv; 1909 1910 sv.sival_ptr = uap->value; 1911 1912 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1913 } 1914 1915 int 1916 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1917 { 1918 ksiginfo_t ksi; 1919 struct proc *p; 1920 int error; 1921 1922 if ((u_int)signum > _SIG_MAXSIG) 1923 return (EINVAL); 1924 1925 /* 1926 * Specification says sigqueue can only send signal to 1927 * single process. 1928 */ 1929 if (pid <= 0) 1930 return (EINVAL); 1931 1932 if ((p = pfind_any(pid)) == NULL) 1933 return (ESRCH); 1934 error = p_cansignal(td, p, signum); 1935 if (error == 0 && signum != 0) { 1936 ksiginfo_init(&ksi); 1937 ksi.ksi_flags = KSI_SIGQ; 1938 ksi.ksi_signo = signum; 1939 ksi.ksi_code = SI_QUEUE; 1940 ksi.ksi_pid = td->td_proc->p_pid; 1941 ksi.ksi_uid = td->td_ucred->cr_ruid; 1942 ksi.ksi_value = *value; 1943 error = pksignal(p, ksi.ksi_signo, &ksi); 1944 } 1945 PROC_UNLOCK(p); 1946 return (error); 1947 } 1948 1949 /* 1950 * Send a signal to a process group. 1951 */ 1952 void 1953 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1954 { 1955 struct pgrp *pgrp; 1956 1957 if (pgid != 0) { 1958 sx_slock(&proctree_lock); 1959 pgrp = pgfind(pgid); 1960 sx_sunlock(&proctree_lock); 1961 if (pgrp != NULL) { 1962 pgsignal(pgrp, sig, 0, ksi); 1963 PGRP_UNLOCK(pgrp); 1964 } 1965 } 1966 } 1967 1968 /* 1969 * Send a signal to a process group. If checktty is 1, 1970 * limit to members which have a controlling terminal. 1971 */ 1972 void 1973 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1974 { 1975 struct proc *p; 1976 1977 if (pgrp) { 1978 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1979 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1980 PROC_LOCK(p); 1981 if (p->p_state == PRS_NORMAL && 1982 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1983 pksignal(p, sig, ksi); 1984 PROC_UNLOCK(p); 1985 } 1986 } 1987 } 1988 1989 /* 1990 * Recalculate the signal mask and reset the signal disposition after 1991 * usermode frame for delivery is formed. Should be called after 1992 * mach-specific routine, because sysent->sv_sendsig() needs correct 1993 * ps_siginfo and signal mask. 1994 */ 1995 static void 1996 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1997 { 1998 sigset_t mask; 1999 2000 mtx_assert(&ps->ps_mtx, MA_OWNED); 2001 td->td_ru.ru_nsignals++; 2002 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2003 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2004 SIGADDSET(mask, sig); 2005 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2006 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2007 if (SIGISMEMBER(ps->ps_sigreset, sig)) 2008 sigdflt(ps, sig); 2009 } 2010 2011 /* 2012 * Send a signal caused by a trap to the current thread. If it will be 2013 * caught immediately, deliver it with correct code. Otherwise, post it 2014 * normally. 2015 */ 2016 void 2017 trapsignal(struct thread *td, ksiginfo_t *ksi) 2018 { 2019 struct sigacts *ps; 2020 struct proc *p; 2021 sigset_t sigmask; 2022 int sig; 2023 2024 p = td->td_proc; 2025 sig = ksi->ksi_signo; 2026 KASSERT(_SIG_VALID(sig), ("invalid signal")); 2027 2028 sigfastblock_fetch(td); 2029 PROC_LOCK(p); 2030 ps = p->p_sigacts; 2031 mtx_lock(&ps->ps_mtx); 2032 sigmask = td->td_sigmask; 2033 if (td->td_sigblock_val != 0) 2034 SIGSETOR(sigmask, fastblock_mask); 2035 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 2036 !SIGISMEMBER(sigmask, sig)) { 2037 #ifdef KTRACE 2038 if (KTRPOINT(curthread, KTR_PSIG)) 2039 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 2040 &td->td_sigmask, ksi->ksi_code); 2041 #endif 2042 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 2043 ksi, &td->td_sigmask); 2044 postsig_done(sig, td, ps); 2045 mtx_unlock(&ps->ps_mtx); 2046 } else { 2047 /* 2048 * Avoid a possible infinite loop if the thread 2049 * masking the signal or process is ignoring the 2050 * signal. 2051 */ 2052 if (kern_forcesigexit && (SIGISMEMBER(sigmask, sig) || 2053 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2054 SIGDELSET(td->td_sigmask, sig); 2055 SIGDELSET(ps->ps_sigcatch, sig); 2056 SIGDELSET(ps->ps_sigignore, sig); 2057 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2058 td->td_pflags &= ~TDP_SIGFASTBLOCK; 2059 td->td_sigblock_val = 0; 2060 } 2061 mtx_unlock(&ps->ps_mtx); 2062 p->p_sig = sig; /* XXX to verify code */ 2063 tdsendsignal(p, td, sig, ksi); 2064 } 2065 PROC_UNLOCK(p); 2066 } 2067 2068 static struct thread * 2069 sigtd(struct proc *p, int sig, bool fast_sigblock) 2070 { 2071 struct thread *td, *signal_td; 2072 2073 PROC_LOCK_ASSERT(p, MA_OWNED); 2074 MPASS(!fast_sigblock || p == curproc); 2075 2076 /* 2077 * Check if current thread can handle the signal without 2078 * switching context to another thread. 2079 */ 2080 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig) && 2081 (!fast_sigblock || curthread->td_sigblock_val == 0)) 2082 return (curthread); 2083 signal_td = NULL; 2084 FOREACH_THREAD_IN_PROC(p, td) { 2085 if (!SIGISMEMBER(td->td_sigmask, sig) && (!fast_sigblock || 2086 td != curthread || td->td_sigblock_val == 0)) { 2087 signal_td = td; 2088 break; 2089 } 2090 } 2091 if (signal_td == NULL) 2092 signal_td = FIRST_THREAD_IN_PROC(p); 2093 return (signal_td); 2094 } 2095 2096 /* 2097 * Send the signal to the process. If the signal has an action, the action 2098 * is usually performed by the target process rather than the caller; we add 2099 * the signal to the set of pending signals for the process. 2100 * 2101 * Exceptions: 2102 * o When a stop signal is sent to a sleeping process that takes the 2103 * default action, the process is stopped without awakening it. 2104 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2105 * regardless of the signal action (eg, blocked or ignored). 2106 * 2107 * Other ignored signals are discarded immediately. 2108 * 2109 * NB: This function may be entered from the debugger via the "kill" DDB 2110 * command. There is little that can be done to mitigate the possibly messy 2111 * side effects of this unwise possibility. 2112 */ 2113 void 2114 kern_psignal(struct proc *p, int sig) 2115 { 2116 ksiginfo_t ksi; 2117 2118 ksiginfo_init(&ksi); 2119 ksi.ksi_signo = sig; 2120 ksi.ksi_code = SI_KERNEL; 2121 (void) tdsendsignal(p, NULL, sig, &ksi); 2122 } 2123 2124 int 2125 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2126 { 2127 2128 return (tdsendsignal(p, NULL, sig, ksi)); 2129 } 2130 2131 /* Utility function for finding a thread to send signal event to. */ 2132 int 2133 sigev_findtd(struct proc *p, struct sigevent *sigev, struct thread **ttd) 2134 { 2135 struct thread *td; 2136 2137 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2138 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2139 if (td == NULL) 2140 return (ESRCH); 2141 *ttd = td; 2142 } else { 2143 *ttd = NULL; 2144 PROC_LOCK(p); 2145 } 2146 return (0); 2147 } 2148 2149 void 2150 tdsignal(struct thread *td, int sig) 2151 { 2152 ksiginfo_t ksi; 2153 2154 ksiginfo_init(&ksi); 2155 ksi.ksi_signo = sig; 2156 ksi.ksi_code = SI_KERNEL; 2157 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2158 } 2159 2160 void 2161 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2162 { 2163 2164 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2165 } 2166 2167 static int 2168 sig_sleepq_abort(struct thread *td, int intrval) 2169 { 2170 THREAD_LOCK_ASSERT(td, MA_OWNED); 2171 2172 if (intrval == 0 && (td->td_flags & TDF_SIGWAIT) == 0) { 2173 thread_unlock(td); 2174 return (0); 2175 } 2176 return (sleepq_abort(td, intrval)); 2177 } 2178 2179 int 2180 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2181 { 2182 sig_t action; 2183 sigqueue_t *sigqueue; 2184 int prop; 2185 struct sigacts *ps; 2186 int intrval; 2187 int ret = 0; 2188 int wakeup_swapper; 2189 2190 MPASS(td == NULL || p == td->td_proc); 2191 PROC_LOCK_ASSERT(p, MA_OWNED); 2192 2193 if (!_SIG_VALID(sig)) 2194 panic("%s(): invalid signal %d", __func__, sig); 2195 2196 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2197 2198 /* 2199 * IEEE Std 1003.1-2001: return success when killing a zombie. 2200 */ 2201 if (p->p_state == PRS_ZOMBIE) { 2202 if (ksi && (ksi->ksi_flags & KSI_INS)) 2203 ksiginfo_tryfree(ksi); 2204 return (ret); 2205 } 2206 2207 ps = p->p_sigacts; 2208 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2209 prop = sigprop(sig); 2210 2211 if (td == NULL) { 2212 td = sigtd(p, sig, false); 2213 sigqueue = &p->p_sigqueue; 2214 } else 2215 sigqueue = &td->td_sigqueue; 2216 2217 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2218 2219 /* 2220 * If the signal is being ignored, then we forget about it 2221 * immediately, except when the target process executes 2222 * sigwait(). (Note: we don't set SIGCONT in ps_sigignore, 2223 * and if it is set to SIG_IGN, action will be SIG_DFL here.) 2224 */ 2225 mtx_lock(&ps->ps_mtx); 2226 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2227 if (kern_sig_discard_ign && 2228 (p->p_sysent->sv_flags & SV_SIG_DISCIGN) == 0) { 2229 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2230 2231 mtx_unlock(&ps->ps_mtx); 2232 if (ksi && (ksi->ksi_flags & KSI_INS)) 2233 ksiginfo_tryfree(ksi); 2234 return (ret); 2235 } else { 2236 action = SIG_CATCH; 2237 intrval = 0; 2238 } 2239 } else { 2240 if (SIGISMEMBER(td->td_sigmask, sig)) 2241 action = SIG_HOLD; 2242 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2243 action = SIG_CATCH; 2244 else 2245 action = SIG_DFL; 2246 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2247 intrval = EINTR; 2248 else 2249 intrval = ERESTART; 2250 } 2251 mtx_unlock(&ps->ps_mtx); 2252 2253 if (prop & SIGPROP_CONT) 2254 sigqueue_delete_stopmask_proc(p); 2255 else if (prop & SIGPROP_STOP) { 2256 /* 2257 * If sending a tty stop signal to a member of an orphaned 2258 * process group, discard the signal here if the action 2259 * is default; don't stop the process below if sleeping, 2260 * and don't clear any pending SIGCONT. 2261 */ 2262 if ((prop & SIGPROP_TTYSTOP) != 0 && 2263 (p->p_pgrp->pg_flags & PGRP_ORPHANED) != 0 && 2264 action == SIG_DFL) { 2265 if (ksi && (ksi->ksi_flags & KSI_INS)) 2266 ksiginfo_tryfree(ksi); 2267 return (ret); 2268 } 2269 sigqueue_delete_proc(p, SIGCONT); 2270 if (p->p_flag & P_CONTINUED) { 2271 p->p_flag &= ~P_CONTINUED; 2272 PROC_LOCK(p->p_pptr); 2273 sigqueue_take(p->p_ksi); 2274 PROC_UNLOCK(p->p_pptr); 2275 } 2276 } 2277 2278 ret = sigqueue_add(sigqueue, sig, ksi); 2279 if (ret != 0) 2280 return (ret); 2281 signotify(td); 2282 /* 2283 * Defer further processing for signals which are held, 2284 * except that stopped processes must be continued by SIGCONT. 2285 */ 2286 if (action == SIG_HOLD && 2287 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2288 return (ret); 2289 2290 wakeup_swapper = 0; 2291 2292 /* 2293 * Some signals have a process-wide effect and a per-thread 2294 * component. Most processing occurs when the process next 2295 * tries to cross the user boundary, however there are some 2296 * times when processing needs to be done immediately, such as 2297 * waking up threads so that they can cross the user boundary. 2298 * We try to do the per-process part here. 2299 */ 2300 if (P_SHOULDSTOP(p)) { 2301 KASSERT(!(p->p_flag & P_WEXIT), 2302 ("signal to stopped but exiting process")); 2303 if (sig == SIGKILL) { 2304 /* 2305 * If traced process is already stopped, 2306 * then no further action is necessary. 2307 */ 2308 if (p->p_flag & P_TRACED) 2309 goto out; 2310 /* 2311 * SIGKILL sets process running. 2312 * It will die elsewhere. 2313 * All threads must be restarted. 2314 */ 2315 p->p_flag &= ~P_STOPPED_SIG; 2316 goto runfast; 2317 } 2318 2319 if (prop & SIGPROP_CONT) { 2320 /* 2321 * If traced process is already stopped, 2322 * then no further action is necessary. 2323 */ 2324 if (p->p_flag & P_TRACED) 2325 goto out; 2326 /* 2327 * If SIGCONT is default (or ignored), we continue the 2328 * process but don't leave the signal in sigqueue as 2329 * it has no further action. If SIGCONT is held, we 2330 * continue the process and leave the signal in 2331 * sigqueue. If the process catches SIGCONT, let it 2332 * handle the signal itself. If it isn't waiting on 2333 * an event, it goes back to run state. 2334 * Otherwise, process goes back to sleep state. 2335 */ 2336 p->p_flag &= ~P_STOPPED_SIG; 2337 PROC_SLOCK(p); 2338 if (p->p_numthreads == p->p_suspcount) { 2339 PROC_SUNLOCK(p); 2340 p->p_flag |= P_CONTINUED; 2341 p->p_xsig = SIGCONT; 2342 PROC_LOCK(p->p_pptr); 2343 childproc_continued(p); 2344 PROC_UNLOCK(p->p_pptr); 2345 PROC_SLOCK(p); 2346 } 2347 if (action == SIG_DFL) { 2348 thread_unsuspend(p); 2349 PROC_SUNLOCK(p); 2350 sigqueue_delete(sigqueue, sig); 2351 goto out_cont; 2352 } 2353 if (action == SIG_CATCH) { 2354 /* 2355 * The process wants to catch it so it needs 2356 * to run at least one thread, but which one? 2357 */ 2358 PROC_SUNLOCK(p); 2359 goto runfast; 2360 } 2361 /* 2362 * The signal is not ignored or caught. 2363 */ 2364 thread_unsuspend(p); 2365 PROC_SUNLOCK(p); 2366 goto out_cont; 2367 } 2368 2369 if (prop & SIGPROP_STOP) { 2370 /* 2371 * If traced process is already stopped, 2372 * then no further action is necessary. 2373 */ 2374 if (p->p_flag & P_TRACED) 2375 goto out; 2376 /* 2377 * Already stopped, don't need to stop again 2378 * (If we did the shell could get confused). 2379 * Just make sure the signal STOP bit set. 2380 */ 2381 p->p_flag |= P_STOPPED_SIG; 2382 sigqueue_delete(sigqueue, sig); 2383 goto out; 2384 } 2385 2386 /* 2387 * All other kinds of signals: 2388 * If a thread is sleeping interruptibly, simulate a 2389 * wakeup so that when it is continued it will be made 2390 * runnable and can look at the signal. However, don't make 2391 * the PROCESS runnable, leave it stopped. 2392 * It may run a bit until it hits a thread_suspend_check(). 2393 */ 2394 PROC_SLOCK(p); 2395 thread_lock(td); 2396 if (TD_CAN_ABORT(td)) 2397 wakeup_swapper = sig_sleepq_abort(td, intrval); 2398 else 2399 thread_unlock(td); 2400 PROC_SUNLOCK(p); 2401 goto out; 2402 /* 2403 * Mutexes are short lived. Threads waiting on them will 2404 * hit thread_suspend_check() soon. 2405 */ 2406 } else if (p->p_state == PRS_NORMAL) { 2407 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2408 tdsigwakeup(td, sig, action, intrval); 2409 goto out; 2410 } 2411 2412 MPASS(action == SIG_DFL); 2413 2414 if (prop & SIGPROP_STOP) { 2415 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2416 goto out; 2417 p->p_flag |= P_STOPPED_SIG; 2418 p->p_xsig = sig; 2419 PROC_SLOCK(p); 2420 wakeup_swapper = sig_suspend_threads(td, p, 1); 2421 if (p->p_numthreads == p->p_suspcount) { 2422 /* 2423 * only thread sending signal to another 2424 * process can reach here, if thread is sending 2425 * signal to its process, because thread does 2426 * not suspend itself here, p_numthreads 2427 * should never be equal to p_suspcount. 2428 */ 2429 thread_stopped(p); 2430 PROC_SUNLOCK(p); 2431 sigqueue_delete_proc(p, p->p_xsig); 2432 } else 2433 PROC_SUNLOCK(p); 2434 goto out; 2435 } 2436 } else { 2437 /* Not in "NORMAL" state. discard the signal. */ 2438 sigqueue_delete(sigqueue, sig); 2439 goto out; 2440 } 2441 2442 /* 2443 * The process is not stopped so we need to apply the signal to all the 2444 * running threads. 2445 */ 2446 runfast: 2447 tdsigwakeup(td, sig, action, intrval); 2448 PROC_SLOCK(p); 2449 thread_unsuspend(p); 2450 PROC_SUNLOCK(p); 2451 out_cont: 2452 itimer_proc_continue(p); 2453 kqtimer_proc_continue(p); 2454 out: 2455 /* If we jump here, proc slock should not be owned. */ 2456 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2457 if (wakeup_swapper) 2458 kick_proc0(); 2459 2460 return (ret); 2461 } 2462 2463 /* 2464 * The force of a signal has been directed against a single 2465 * thread. We need to see what we can do about knocking it 2466 * out of any sleep it may be in etc. 2467 */ 2468 static void 2469 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2470 { 2471 struct proc *p = td->td_proc; 2472 int prop, wakeup_swapper; 2473 2474 PROC_LOCK_ASSERT(p, MA_OWNED); 2475 prop = sigprop(sig); 2476 2477 PROC_SLOCK(p); 2478 thread_lock(td); 2479 /* 2480 * Bring the priority of a thread up if we want it to get 2481 * killed in this lifetime. Be careful to avoid bumping the 2482 * priority of the idle thread, since we still allow to signal 2483 * kernel processes. 2484 */ 2485 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2486 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2487 sched_prio(td, PUSER); 2488 if (TD_ON_SLEEPQ(td)) { 2489 /* 2490 * If thread is sleeping uninterruptibly 2491 * we can't interrupt the sleep... the signal will 2492 * be noticed when the process returns through 2493 * trap() or syscall(). 2494 */ 2495 if ((td->td_flags & TDF_SINTR) == 0) 2496 goto out; 2497 /* 2498 * If SIGCONT is default (or ignored) and process is 2499 * asleep, we are finished; the process should not 2500 * be awakened. 2501 */ 2502 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2503 thread_unlock(td); 2504 PROC_SUNLOCK(p); 2505 sigqueue_delete(&p->p_sigqueue, sig); 2506 /* 2507 * It may be on either list in this state. 2508 * Remove from both for now. 2509 */ 2510 sigqueue_delete(&td->td_sigqueue, sig); 2511 return; 2512 } 2513 2514 /* 2515 * Don't awaken a sleeping thread for SIGSTOP if the 2516 * STOP signal is deferred. 2517 */ 2518 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2519 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2520 goto out; 2521 2522 /* 2523 * Give low priority threads a better chance to run. 2524 */ 2525 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2526 sched_prio(td, PUSER); 2527 2528 wakeup_swapper = sig_sleepq_abort(td, intrval); 2529 PROC_SUNLOCK(p); 2530 if (wakeup_swapper) 2531 kick_proc0(); 2532 return; 2533 } 2534 2535 /* 2536 * Other states do nothing with the signal immediately, 2537 * other than kicking ourselves if we are running. 2538 * It will either never be noticed, or noticed very soon. 2539 */ 2540 #ifdef SMP 2541 if (TD_IS_RUNNING(td) && td != curthread) 2542 forward_signal(td); 2543 #endif 2544 2545 out: 2546 PROC_SUNLOCK(p); 2547 thread_unlock(td); 2548 } 2549 2550 static void 2551 ptrace_coredump(struct thread *td) 2552 { 2553 struct proc *p; 2554 struct thr_coredump_req *tcq; 2555 void *rl_cookie; 2556 2557 MPASS(td == curthread); 2558 p = td->td_proc; 2559 PROC_LOCK_ASSERT(p, MA_OWNED); 2560 if ((td->td_dbgflags & TDB_COREDUMPRQ) == 0) 2561 return; 2562 KASSERT((p->p_flag & P_STOPPED_TRACE) != 0, ("not stopped")); 2563 2564 tcq = td->td_coredump; 2565 KASSERT(tcq != NULL, ("td_coredump is NULL")); 2566 2567 if (p->p_sysent->sv_coredump == NULL) { 2568 tcq->tc_error = ENOSYS; 2569 goto wake; 2570 } 2571 2572 PROC_UNLOCK(p); 2573 rl_cookie = vn_rangelock_wlock(tcq->tc_vp, 0, OFF_MAX); 2574 2575 tcq->tc_error = p->p_sysent->sv_coredump(td, tcq->tc_vp, 2576 tcq->tc_limit, tcq->tc_flags); 2577 2578 vn_rangelock_unlock(tcq->tc_vp, rl_cookie); 2579 PROC_LOCK(p); 2580 wake: 2581 td->td_dbgflags &= ~TDB_COREDUMPRQ; 2582 td->td_coredump = NULL; 2583 wakeup(p); 2584 } 2585 2586 static int 2587 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2588 { 2589 struct thread *td2; 2590 int wakeup_swapper; 2591 2592 PROC_LOCK_ASSERT(p, MA_OWNED); 2593 PROC_SLOCK_ASSERT(p, MA_OWNED); 2594 MPASS(sending || td == curthread); 2595 2596 wakeup_swapper = 0; 2597 FOREACH_THREAD_IN_PROC(p, td2) { 2598 thread_lock(td2); 2599 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2600 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2601 (td2->td_flags & TDF_SINTR)) { 2602 if (td2->td_flags & TDF_SBDRY) { 2603 /* 2604 * Once a thread is asleep with 2605 * TDF_SBDRY and without TDF_SERESTART 2606 * or TDF_SEINTR set, it should never 2607 * become suspended due to this check. 2608 */ 2609 KASSERT(!TD_IS_SUSPENDED(td2), 2610 ("thread with deferred stops suspended")); 2611 if (TD_SBDRY_INTR(td2)) { 2612 wakeup_swapper |= sleepq_abort(td2, 2613 TD_SBDRY_ERRNO(td2)); 2614 continue; 2615 } 2616 } else if (!TD_IS_SUSPENDED(td2)) 2617 thread_suspend_one(td2); 2618 } else if (!TD_IS_SUSPENDED(td2)) { 2619 if (sending || td != td2) 2620 td2->td_flags |= TDF_ASTPENDING; 2621 #ifdef SMP 2622 if (TD_IS_RUNNING(td2) && td2 != td) 2623 forward_signal(td2); 2624 #endif 2625 } 2626 thread_unlock(td2); 2627 } 2628 return (wakeup_swapper); 2629 } 2630 2631 /* 2632 * Stop the process for an event deemed interesting to the debugger. If si is 2633 * non-NULL, this is a signal exchange; the new signal requested by the 2634 * debugger will be returned for handling. If si is NULL, this is some other 2635 * type of interesting event. The debugger may request a signal be delivered in 2636 * that case as well, however it will be deferred until it can be handled. 2637 */ 2638 int 2639 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2640 { 2641 struct proc *p = td->td_proc; 2642 struct thread *td2; 2643 ksiginfo_t ksi; 2644 2645 PROC_LOCK_ASSERT(p, MA_OWNED); 2646 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2647 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2648 &p->p_mtx.lock_object, "Stopping for traced signal"); 2649 2650 td->td_xsig = sig; 2651 2652 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2653 td->td_dbgflags |= TDB_XSIG; 2654 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2655 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2656 PROC_SLOCK(p); 2657 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2658 if (P_KILLED(p)) { 2659 /* 2660 * Ensure that, if we've been PT_KILLed, the 2661 * exit status reflects that. Another thread 2662 * may also be in ptracestop(), having just 2663 * received the SIGKILL, but this thread was 2664 * unsuspended first. 2665 */ 2666 td->td_dbgflags &= ~TDB_XSIG; 2667 td->td_xsig = SIGKILL; 2668 p->p_ptevents = 0; 2669 break; 2670 } 2671 if (p->p_flag & P_SINGLE_EXIT && 2672 !(td->td_dbgflags & TDB_EXIT)) { 2673 /* 2674 * Ignore ptrace stops except for thread exit 2675 * events when the process exits. 2676 */ 2677 td->td_dbgflags &= ~TDB_XSIG; 2678 PROC_SUNLOCK(p); 2679 return (0); 2680 } 2681 2682 /* 2683 * Make wait(2) work. Ensure that right after the 2684 * attach, the thread which was decided to become the 2685 * leader of attach gets reported to the waiter. 2686 * Otherwise, just avoid overwriting another thread's 2687 * assignment to p_xthread. If another thread has 2688 * already set p_xthread, the current thread will get 2689 * a chance to report itself upon the next iteration. 2690 */ 2691 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2692 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2693 p->p_xthread == NULL)) { 2694 p->p_xsig = sig; 2695 p->p_xthread = td; 2696 2697 /* 2698 * If we are on sleepqueue already, 2699 * let sleepqueue code decide if it 2700 * needs to go sleep after attach. 2701 */ 2702 if (td->td_wchan == NULL) 2703 td->td_dbgflags &= ~TDB_FSTP; 2704 2705 p->p_flag2 &= ~P2_PTRACE_FSTP; 2706 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2707 sig_suspend_threads(td, p, 0); 2708 } 2709 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2710 td->td_dbgflags &= ~TDB_STOPATFORK; 2711 } 2712 stopme: 2713 td->td_dbgflags |= TDB_SSWITCH; 2714 thread_suspend_switch(td, p); 2715 td->td_dbgflags &= ~TDB_SSWITCH; 2716 if ((td->td_dbgflags & TDB_COREDUMPRQ) != 0) { 2717 PROC_SUNLOCK(p); 2718 ptrace_coredump(td); 2719 PROC_SLOCK(p); 2720 goto stopme; 2721 } 2722 if (p->p_xthread == td) 2723 p->p_xthread = NULL; 2724 if (!(p->p_flag & P_TRACED)) 2725 break; 2726 if (td->td_dbgflags & TDB_SUSPEND) { 2727 if (p->p_flag & P_SINGLE_EXIT) 2728 break; 2729 goto stopme; 2730 } 2731 } 2732 PROC_SUNLOCK(p); 2733 } 2734 2735 if (si != NULL && sig == td->td_xsig) { 2736 /* Parent wants us to take the original signal unchanged. */ 2737 si->ksi_flags |= KSI_HEAD; 2738 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2739 si->ksi_signo = 0; 2740 } else if (td->td_xsig != 0) { 2741 /* 2742 * If parent wants us to take a new signal, then it will leave 2743 * it in td->td_xsig; otherwise we just look for signals again. 2744 */ 2745 ksiginfo_init(&ksi); 2746 ksi.ksi_signo = td->td_xsig; 2747 ksi.ksi_flags |= KSI_PTRACE; 2748 td2 = sigtd(p, td->td_xsig, false); 2749 tdsendsignal(p, td2, td->td_xsig, &ksi); 2750 if (td != td2) 2751 return (0); 2752 } 2753 2754 return (td->td_xsig); 2755 } 2756 2757 static void 2758 reschedule_signals(struct proc *p, sigset_t block, int flags) 2759 { 2760 struct sigacts *ps; 2761 struct thread *td; 2762 int sig; 2763 bool fastblk, pslocked; 2764 2765 PROC_LOCK_ASSERT(p, MA_OWNED); 2766 ps = p->p_sigacts; 2767 pslocked = (flags & SIGPROCMASK_PS_LOCKED) != 0; 2768 mtx_assert(&ps->ps_mtx, pslocked ? MA_OWNED : MA_NOTOWNED); 2769 if (SIGISEMPTY(p->p_siglist)) 2770 return; 2771 SIGSETAND(block, p->p_siglist); 2772 fastblk = (flags & SIGPROCMASK_FASTBLK) != 0; 2773 SIG_FOREACH(sig, &block) { 2774 td = sigtd(p, sig, fastblk); 2775 2776 /* 2777 * If sigtd() selected us despite sigfastblock is 2778 * blocking, do not activate AST or wake us, to avoid 2779 * loop in AST handler. 2780 */ 2781 if (fastblk && td == curthread) 2782 continue; 2783 2784 signotify(td); 2785 if (!pslocked) 2786 mtx_lock(&ps->ps_mtx); 2787 if (p->p_flag & P_TRACED || 2788 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2789 !SIGISMEMBER(td->td_sigmask, sig))) { 2790 tdsigwakeup(td, sig, SIG_CATCH, 2791 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2792 ERESTART)); 2793 } 2794 if (!pslocked) 2795 mtx_unlock(&ps->ps_mtx); 2796 } 2797 } 2798 2799 void 2800 tdsigcleanup(struct thread *td) 2801 { 2802 struct proc *p; 2803 sigset_t unblocked; 2804 2805 p = td->td_proc; 2806 PROC_LOCK_ASSERT(p, MA_OWNED); 2807 2808 sigqueue_flush(&td->td_sigqueue); 2809 if (p->p_numthreads == 1) 2810 return; 2811 2812 /* 2813 * Since we cannot handle signals, notify signal post code 2814 * about this by filling the sigmask. 2815 * 2816 * Also, if needed, wake up thread(s) that do not block the 2817 * same signals as the exiting thread, since the thread might 2818 * have been selected for delivery and woken up. 2819 */ 2820 SIGFILLSET(unblocked); 2821 SIGSETNAND(unblocked, td->td_sigmask); 2822 SIGFILLSET(td->td_sigmask); 2823 reschedule_signals(p, unblocked, 0); 2824 2825 } 2826 2827 static int 2828 sigdeferstop_curr_flags(int cflags) 2829 { 2830 2831 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2832 (cflags & TDF_SBDRY) != 0); 2833 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2834 } 2835 2836 /* 2837 * Defer the delivery of SIGSTOP for the current thread, according to 2838 * the requested mode. Returns previous flags, which must be restored 2839 * by sigallowstop(). 2840 * 2841 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2842 * cleared by the current thread, which allow the lock-less read-only 2843 * accesses below. 2844 */ 2845 int 2846 sigdeferstop_impl(int mode) 2847 { 2848 struct thread *td; 2849 int cflags, nflags; 2850 2851 td = curthread; 2852 cflags = sigdeferstop_curr_flags(td->td_flags); 2853 switch (mode) { 2854 case SIGDEFERSTOP_NOP: 2855 nflags = cflags; 2856 break; 2857 case SIGDEFERSTOP_OFF: 2858 nflags = 0; 2859 break; 2860 case SIGDEFERSTOP_SILENT: 2861 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2862 break; 2863 case SIGDEFERSTOP_EINTR: 2864 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2865 break; 2866 case SIGDEFERSTOP_ERESTART: 2867 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2868 break; 2869 default: 2870 panic("sigdeferstop: invalid mode %x", mode); 2871 break; 2872 } 2873 if (cflags == nflags) 2874 return (SIGDEFERSTOP_VAL_NCHG); 2875 thread_lock(td); 2876 td->td_flags = (td->td_flags & ~cflags) | nflags; 2877 thread_unlock(td); 2878 return (cflags); 2879 } 2880 2881 /* 2882 * Restores the STOP handling mode, typically permitting the delivery 2883 * of SIGSTOP for the current thread. This does not immediately 2884 * suspend if a stop was posted. Instead, the thread will suspend 2885 * either via ast() or a subsequent interruptible sleep. 2886 */ 2887 void 2888 sigallowstop_impl(int prev) 2889 { 2890 struct thread *td; 2891 int cflags; 2892 2893 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2894 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2895 ("sigallowstop: incorrect previous mode %x", prev)); 2896 td = curthread; 2897 cflags = sigdeferstop_curr_flags(td->td_flags); 2898 if (cflags != prev) { 2899 thread_lock(td); 2900 td->td_flags = (td->td_flags & ~cflags) | prev; 2901 thread_unlock(td); 2902 } 2903 } 2904 2905 enum sigstatus { 2906 SIGSTATUS_HANDLE, 2907 SIGSTATUS_HANDLED, 2908 SIGSTATUS_IGNORE, 2909 SIGSTATUS_SBDRY_STOP, 2910 }; 2911 2912 /* 2913 * The thread has signal "sig" pending. Figure out what to do with it: 2914 * 2915 * _HANDLE -> the caller should handle the signal 2916 * _HANDLED -> handled internally, reload pending signal set 2917 * _IGNORE -> ignored, remove from the set of pending signals and try the 2918 * next pending signal 2919 * _SBDRY_STOP -> the signal should stop the thread but this is not 2920 * permitted in the current context 2921 */ 2922 static enum sigstatus 2923 sigprocess(struct thread *td, int sig) 2924 { 2925 struct proc *p; 2926 struct sigacts *ps; 2927 struct sigqueue *queue; 2928 ksiginfo_t ksi; 2929 int prop; 2930 2931 KASSERT(_SIG_VALID(sig), ("%s: invalid signal %d", __func__, sig)); 2932 2933 p = td->td_proc; 2934 ps = p->p_sigacts; 2935 mtx_assert(&ps->ps_mtx, MA_OWNED); 2936 PROC_LOCK_ASSERT(p, MA_OWNED); 2937 2938 /* 2939 * We should allow pending but ignored signals below 2940 * only if there is sigwait() active, or P_TRACED was 2941 * on when they were posted. 2942 */ 2943 if (SIGISMEMBER(ps->ps_sigignore, sig) && 2944 (p->p_flag & P_TRACED) == 0 && 2945 (td->td_flags & TDF_SIGWAIT) == 0) { 2946 return (SIGSTATUS_IGNORE); 2947 } 2948 2949 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2950 /* 2951 * If traced, always stop. 2952 * Remove old signal from queue before the stop. 2953 * XXX shrug off debugger, it causes siginfo to 2954 * be thrown away. 2955 */ 2956 queue = &td->td_sigqueue; 2957 ksiginfo_init(&ksi); 2958 if (sigqueue_get(queue, sig, &ksi) == 0) { 2959 queue = &p->p_sigqueue; 2960 sigqueue_get(queue, sig, &ksi); 2961 } 2962 td->td_si = ksi.ksi_info; 2963 2964 mtx_unlock(&ps->ps_mtx); 2965 sig = ptracestop(td, sig, &ksi); 2966 mtx_lock(&ps->ps_mtx); 2967 2968 td->td_si.si_signo = 0; 2969 2970 /* 2971 * Keep looking if the debugger discarded or 2972 * replaced the signal. 2973 */ 2974 if (sig == 0) 2975 return (SIGSTATUS_HANDLED); 2976 2977 /* 2978 * If the signal became masked, re-queue it. 2979 */ 2980 if (SIGISMEMBER(td->td_sigmask, sig)) { 2981 ksi.ksi_flags |= KSI_HEAD; 2982 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2983 return (SIGSTATUS_HANDLED); 2984 } 2985 2986 /* 2987 * If the traced bit got turned off, requeue the signal and 2988 * reload the set of pending signals. This ensures that p_sig* 2989 * and p_sigact are consistent. 2990 */ 2991 if ((p->p_flag & P_TRACED) == 0) { 2992 if ((ksi.ksi_flags & KSI_PTRACE) == 0) { 2993 ksi.ksi_flags |= KSI_HEAD; 2994 sigqueue_add(queue, sig, &ksi); 2995 } 2996 return (SIGSTATUS_HANDLED); 2997 } 2998 } 2999 3000 /* 3001 * Decide whether the signal should be returned. 3002 * Return the signal's number, or fall through 3003 * to clear it from the pending mask. 3004 */ 3005 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 3006 case (intptr_t)SIG_DFL: 3007 /* 3008 * Don't take default actions on system processes. 3009 */ 3010 if (p->p_pid <= 1) { 3011 #ifdef DIAGNOSTIC 3012 /* 3013 * Are you sure you want to ignore SIGSEGV 3014 * in init? XXX 3015 */ 3016 printf("Process (pid %lu) got signal %d\n", 3017 (u_long)p->p_pid, sig); 3018 #endif 3019 return (SIGSTATUS_IGNORE); 3020 } 3021 3022 /* 3023 * If there is a pending stop signal to process with 3024 * default action, stop here, then clear the signal. 3025 * Traced or exiting processes should ignore stops. 3026 * Additionally, a member of an orphaned process group 3027 * should ignore tty stops. 3028 */ 3029 prop = sigprop(sig); 3030 if (prop & SIGPROP_STOP) { 3031 mtx_unlock(&ps->ps_mtx); 3032 if ((p->p_flag & (P_TRACED | P_WEXIT | 3033 P_SINGLE_EXIT)) != 0 || ((p->p_pgrp-> 3034 pg_flags & PGRP_ORPHANED) != 0 && 3035 (prop & SIGPROP_TTYSTOP) != 0)) { 3036 mtx_lock(&ps->ps_mtx); 3037 return (SIGSTATUS_IGNORE); 3038 } 3039 if (TD_SBDRY_INTR(td)) { 3040 KASSERT((td->td_flags & TDF_SBDRY) != 0, 3041 ("lost TDF_SBDRY")); 3042 mtx_lock(&ps->ps_mtx); 3043 return (SIGSTATUS_SBDRY_STOP); 3044 } 3045 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 3046 &p->p_mtx.lock_object, "Catching SIGSTOP"); 3047 sigqueue_delete(&td->td_sigqueue, sig); 3048 sigqueue_delete(&p->p_sigqueue, sig); 3049 p->p_flag |= P_STOPPED_SIG; 3050 p->p_xsig = sig; 3051 PROC_SLOCK(p); 3052 sig_suspend_threads(td, p, 0); 3053 thread_suspend_switch(td, p); 3054 PROC_SUNLOCK(p); 3055 mtx_lock(&ps->ps_mtx); 3056 return (SIGSTATUS_HANDLED); 3057 } else if ((prop & SIGPROP_IGNORE) != 0 && 3058 (td->td_flags & TDF_SIGWAIT) == 0) { 3059 /* 3060 * Default action is to ignore; drop it if 3061 * not in kern_sigtimedwait(). 3062 */ 3063 return (SIGSTATUS_IGNORE); 3064 } else { 3065 return (SIGSTATUS_HANDLE); 3066 } 3067 3068 case (intptr_t)SIG_IGN: 3069 if ((td->td_flags & TDF_SIGWAIT) == 0) 3070 return (SIGSTATUS_IGNORE); 3071 else 3072 return (SIGSTATUS_HANDLE); 3073 3074 default: 3075 /* 3076 * This signal has an action, let postsig() process it. 3077 */ 3078 return (SIGSTATUS_HANDLE); 3079 } 3080 } 3081 3082 /* 3083 * If the current process has received a signal (should be caught or cause 3084 * termination, should interrupt current syscall), return the signal number. 3085 * Stop signals with default action are processed immediately, then cleared; 3086 * they aren't returned. This is checked after each entry to the system for 3087 * a syscall or trap (though this can usually be done without calling 3088 * issignal by checking the pending signal masks in cursig.) The normal call 3089 * sequence is 3090 * 3091 * while (sig = cursig(curthread)) 3092 * postsig(sig); 3093 */ 3094 static int 3095 issignal(struct thread *td) 3096 { 3097 struct proc *p; 3098 sigset_t sigpending; 3099 int sig; 3100 3101 p = td->td_proc; 3102 PROC_LOCK_ASSERT(p, MA_OWNED); 3103 3104 for (;;) { 3105 sigpending = td->td_sigqueue.sq_signals; 3106 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 3107 SIGSETNAND(sigpending, td->td_sigmask); 3108 3109 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 3110 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 3111 SIG_STOPSIGMASK(sigpending); 3112 if (SIGISEMPTY(sigpending)) /* no signal to send */ 3113 return (0); 3114 3115 /* 3116 * Do fast sigblock if requested by usermode. Since 3117 * we do know that there was a signal pending at this 3118 * point, set the FAST_SIGBLOCK_PEND as indicator for 3119 * usermode to perform a dummy call to 3120 * FAST_SIGBLOCK_UNBLOCK, which causes immediate 3121 * delivery of postponed pending signal. 3122 */ 3123 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 3124 if (td->td_sigblock_val != 0) 3125 SIGSETNAND(sigpending, fastblock_mask); 3126 if (SIGISEMPTY(sigpending)) { 3127 td->td_pflags |= TDP_SIGFASTPENDING; 3128 return (0); 3129 } 3130 } 3131 3132 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 3133 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 3134 SIGISMEMBER(sigpending, SIGSTOP)) { 3135 /* 3136 * If debugger just attached, always consume 3137 * SIGSTOP from ptrace(PT_ATTACH) first, to 3138 * execute the debugger attach ritual in 3139 * order. 3140 */ 3141 td->td_dbgflags |= TDB_FSTP; 3142 SIGEMPTYSET(sigpending); 3143 SIGADDSET(sigpending, SIGSTOP); 3144 } 3145 3146 SIG_FOREACH(sig, &sigpending) { 3147 switch (sigprocess(td, sig)) { 3148 case SIGSTATUS_HANDLE: 3149 return (sig); 3150 case SIGSTATUS_HANDLED: 3151 goto next; 3152 case SIGSTATUS_IGNORE: 3153 sigqueue_delete(&td->td_sigqueue, sig); 3154 sigqueue_delete(&p->p_sigqueue, sig); 3155 break; 3156 case SIGSTATUS_SBDRY_STOP: 3157 return (-1); 3158 } 3159 } 3160 next:; 3161 } 3162 } 3163 3164 void 3165 thread_stopped(struct proc *p) 3166 { 3167 int n; 3168 3169 PROC_LOCK_ASSERT(p, MA_OWNED); 3170 PROC_SLOCK_ASSERT(p, MA_OWNED); 3171 n = p->p_suspcount; 3172 if (p == curproc) 3173 n++; 3174 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 3175 PROC_SUNLOCK(p); 3176 p->p_flag &= ~P_WAITED; 3177 PROC_LOCK(p->p_pptr); 3178 childproc_stopped(p, (p->p_flag & P_TRACED) ? 3179 CLD_TRAPPED : CLD_STOPPED); 3180 PROC_UNLOCK(p->p_pptr); 3181 PROC_SLOCK(p); 3182 } 3183 } 3184 3185 /* 3186 * Take the action for the specified signal 3187 * from the current set of pending signals. 3188 */ 3189 int 3190 postsig(int sig) 3191 { 3192 struct thread *td; 3193 struct proc *p; 3194 struct sigacts *ps; 3195 sig_t action; 3196 ksiginfo_t ksi; 3197 sigset_t returnmask; 3198 3199 KASSERT(sig != 0, ("postsig")); 3200 3201 td = curthread; 3202 p = td->td_proc; 3203 PROC_LOCK_ASSERT(p, MA_OWNED); 3204 ps = p->p_sigacts; 3205 mtx_assert(&ps->ps_mtx, MA_OWNED); 3206 ksiginfo_init(&ksi); 3207 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3208 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3209 return (0); 3210 ksi.ksi_signo = sig; 3211 if (ksi.ksi_code == SI_TIMER) 3212 itimer_accept(p, ksi.ksi_timerid, &ksi); 3213 action = ps->ps_sigact[_SIG_IDX(sig)]; 3214 #ifdef KTRACE 3215 if (KTRPOINT(td, KTR_PSIG)) 3216 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3217 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3218 #endif 3219 3220 if (action == SIG_DFL) { 3221 /* 3222 * Default action, where the default is to kill 3223 * the process. (Other cases were ignored above.) 3224 */ 3225 mtx_unlock(&ps->ps_mtx); 3226 proc_td_siginfo_capture(td, &ksi.ksi_info); 3227 sigexit(td, sig); 3228 /* NOTREACHED */ 3229 } else { 3230 /* 3231 * If we get here, the signal must be caught. 3232 */ 3233 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3234 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3235 ("postsig action: blocked sig %d", sig)); 3236 3237 /* 3238 * Set the new mask value and also defer further 3239 * occurrences of this signal. 3240 * 3241 * Special case: user has done a sigsuspend. Here the 3242 * current mask is not of interest, but rather the 3243 * mask from before the sigsuspend is what we want 3244 * restored after the signal processing is completed. 3245 */ 3246 if (td->td_pflags & TDP_OLDMASK) { 3247 returnmask = td->td_oldsigmask; 3248 td->td_pflags &= ~TDP_OLDMASK; 3249 } else 3250 returnmask = td->td_sigmask; 3251 3252 if (p->p_sig == sig) { 3253 p->p_sig = 0; 3254 } 3255 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3256 postsig_done(sig, td, ps); 3257 } 3258 return (1); 3259 } 3260 3261 int 3262 sig_ast_checksusp(struct thread *td) 3263 { 3264 struct proc *p __diagused; 3265 int ret; 3266 3267 p = td->td_proc; 3268 PROC_LOCK_ASSERT(p, MA_OWNED); 3269 3270 if ((td->td_flags & TDF_NEEDSUSPCHK) == 0) 3271 return (0); 3272 3273 ret = thread_suspend_check(1); 3274 MPASS(ret == 0 || ret == EINTR || ret == ERESTART); 3275 return (ret); 3276 } 3277 3278 int 3279 sig_ast_needsigchk(struct thread *td) 3280 { 3281 struct proc *p; 3282 struct sigacts *ps; 3283 int ret, sig; 3284 3285 p = td->td_proc; 3286 PROC_LOCK_ASSERT(p, MA_OWNED); 3287 3288 if ((td->td_flags & TDF_NEEDSIGCHK) == 0) 3289 return (0); 3290 3291 ps = p->p_sigacts; 3292 mtx_lock(&ps->ps_mtx); 3293 sig = cursig(td); 3294 if (sig == -1) { 3295 mtx_unlock(&ps->ps_mtx); 3296 KASSERT((td->td_flags & TDF_SBDRY) != 0, ("lost TDF_SBDRY")); 3297 KASSERT(TD_SBDRY_INTR(td), 3298 ("lost TDF_SERESTART of TDF_SEINTR")); 3299 KASSERT((td->td_flags & (TDF_SEINTR | TDF_SERESTART)) != 3300 (TDF_SEINTR | TDF_SERESTART), 3301 ("both TDF_SEINTR and TDF_SERESTART")); 3302 ret = TD_SBDRY_ERRNO(td); 3303 } else if (sig != 0) { 3304 ret = SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : ERESTART; 3305 mtx_unlock(&ps->ps_mtx); 3306 } else { 3307 mtx_unlock(&ps->ps_mtx); 3308 ret = 0; 3309 } 3310 3311 /* 3312 * Do not go into sleep if this thread was the ptrace(2) 3313 * attach leader. cursig() consumed SIGSTOP from PT_ATTACH, 3314 * but we usually act on the signal by interrupting sleep, and 3315 * should do that here as well. 3316 */ 3317 if ((td->td_dbgflags & TDB_FSTP) != 0) { 3318 if (ret == 0) 3319 ret = EINTR; 3320 td->td_dbgflags &= ~TDB_FSTP; 3321 } 3322 3323 return (ret); 3324 } 3325 3326 int 3327 sig_intr(void) 3328 { 3329 struct thread *td; 3330 struct proc *p; 3331 int ret; 3332 3333 td = curthread; 3334 if ((td->td_flags & (TDF_NEEDSIGCHK | TDF_NEEDSUSPCHK)) == 0) 3335 return (0); 3336 3337 p = td->td_proc; 3338 3339 PROC_LOCK(p); 3340 ret = sig_ast_checksusp(td); 3341 if (ret == 0) 3342 ret = sig_ast_needsigchk(td); 3343 PROC_UNLOCK(p); 3344 return (ret); 3345 } 3346 3347 bool 3348 curproc_sigkilled(void) 3349 { 3350 struct thread *td; 3351 struct proc *p; 3352 struct sigacts *ps; 3353 bool res; 3354 3355 td = curthread; 3356 if ((td->td_flags & TDF_NEEDSIGCHK) == 0) 3357 return (false); 3358 3359 p = td->td_proc; 3360 PROC_LOCK(p); 3361 ps = p->p_sigacts; 3362 mtx_lock(&ps->ps_mtx); 3363 res = SIGISMEMBER(td->td_sigqueue.sq_signals, SIGKILL) || 3364 SIGISMEMBER(p->p_sigqueue.sq_signals, SIGKILL); 3365 mtx_unlock(&ps->ps_mtx); 3366 PROC_UNLOCK(p); 3367 return (res); 3368 } 3369 3370 void 3371 proc_wkilled(struct proc *p) 3372 { 3373 3374 PROC_LOCK_ASSERT(p, MA_OWNED); 3375 if ((p->p_flag & P_WKILLED) == 0) { 3376 p->p_flag |= P_WKILLED; 3377 /* 3378 * Notify swapper that there is a process to swap in. 3379 * The notification is racy, at worst it would take 10 3380 * seconds for the swapper process to notice. 3381 */ 3382 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3383 wakeup(&proc0); 3384 } 3385 } 3386 3387 /* 3388 * Kill the current process for stated reason. 3389 */ 3390 void 3391 killproc(struct proc *p, const char *why) 3392 { 3393 3394 PROC_LOCK_ASSERT(p, MA_OWNED); 3395 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3396 p->p_comm); 3397 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3398 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3399 p->p_ucred->cr_uid, why); 3400 proc_wkilled(p); 3401 kern_psignal(p, SIGKILL); 3402 } 3403 3404 /* 3405 * Force the current process to exit with the specified signal, dumping core 3406 * if appropriate. We bypass the normal tests for masked and caught signals, 3407 * allowing unrecoverable failures to terminate the process without changing 3408 * signal state. Mark the accounting record with the signal termination. 3409 * If dumping core, save the signal number for the debugger. Calls exit and 3410 * does not return. 3411 */ 3412 void 3413 sigexit(struct thread *td, int sig) 3414 { 3415 struct proc *p = td->td_proc; 3416 3417 PROC_LOCK_ASSERT(p, MA_OWNED); 3418 p->p_acflag |= AXSIG; 3419 /* 3420 * We must be single-threading to generate a core dump. This 3421 * ensures that the registers in the core file are up-to-date. 3422 * Also, the ELF dump handler assumes that the thread list doesn't 3423 * change out from under it. 3424 * 3425 * XXX If another thread attempts to single-thread before us 3426 * (e.g. via fork()), we won't get a dump at all. 3427 */ 3428 if ((sigprop(sig) & SIGPROP_CORE) && 3429 thread_single(p, SINGLE_NO_EXIT) == 0) { 3430 p->p_sig = sig; 3431 /* 3432 * Log signals which would cause core dumps 3433 * (Log as LOG_INFO to appease those who don't want 3434 * these messages.) 3435 * XXX : Todo, as well as euid, write out ruid too 3436 * Note that coredump() drops proc lock. 3437 */ 3438 if (coredump(td) == 0) 3439 sig |= WCOREFLAG; 3440 if (kern_logsigexit) 3441 log(LOG_INFO, 3442 "pid %d (%s), jid %d, uid %d: exited on " 3443 "signal %d%s\n", p->p_pid, p->p_comm, 3444 p->p_ucred->cr_prison->pr_id, 3445 td->td_ucred->cr_uid, 3446 sig &~ WCOREFLAG, 3447 sig & WCOREFLAG ? " (core dumped)" : ""); 3448 } else 3449 PROC_UNLOCK(p); 3450 exit1(td, 0, sig); 3451 /* NOTREACHED */ 3452 } 3453 3454 /* 3455 * Send queued SIGCHLD to parent when child process's state 3456 * is changed. 3457 */ 3458 static void 3459 sigparent(struct proc *p, int reason, int status) 3460 { 3461 PROC_LOCK_ASSERT(p, MA_OWNED); 3462 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3463 3464 if (p->p_ksi != NULL) { 3465 p->p_ksi->ksi_signo = SIGCHLD; 3466 p->p_ksi->ksi_code = reason; 3467 p->p_ksi->ksi_status = status; 3468 p->p_ksi->ksi_pid = p->p_pid; 3469 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3470 if (KSI_ONQ(p->p_ksi)) 3471 return; 3472 } 3473 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3474 } 3475 3476 static void 3477 childproc_jobstate(struct proc *p, int reason, int sig) 3478 { 3479 struct sigacts *ps; 3480 3481 PROC_LOCK_ASSERT(p, MA_OWNED); 3482 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3483 3484 /* 3485 * Wake up parent sleeping in kern_wait(), also send 3486 * SIGCHLD to parent, but SIGCHLD does not guarantee 3487 * that parent will awake, because parent may masked 3488 * the signal. 3489 */ 3490 p->p_pptr->p_flag |= P_STATCHILD; 3491 wakeup(p->p_pptr); 3492 3493 ps = p->p_pptr->p_sigacts; 3494 mtx_lock(&ps->ps_mtx); 3495 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3496 mtx_unlock(&ps->ps_mtx); 3497 sigparent(p, reason, sig); 3498 } else 3499 mtx_unlock(&ps->ps_mtx); 3500 } 3501 3502 void 3503 childproc_stopped(struct proc *p, int reason) 3504 { 3505 3506 childproc_jobstate(p, reason, p->p_xsig); 3507 } 3508 3509 void 3510 childproc_continued(struct proc *p) 3511 { 3512 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3513 } 3514 3515 void 3516 childproc_exited(struct proc *p) 3517 { 3518 int reason, status; 3519 3520 if (WCOREDUMP(p->p_xsig)) { 3521 reason = CLD_DUMPED; 3522 status = WTERMSIG(p->p_xsig); 3523 } else if (WIFSIGNALED(p->p_xsig)) { 3524 reason = CLD_KILLED; 3525 status = WTERMSIG(p->p_xsig); 3526 } else { 3527 reason = CLD_EXITED; 3528 status = p->p_xexit; 3529 } 3530 /* 3531 * XXX avoid calling wakeup(p->p_pptr), the work is 3532 * done in exit1(). 3533 */ 3534 sigparent(p, reason, status); 3535 } 3536 3537 #define MAX_NUM_CORE_FILES 100000 3538 #ifndef NUM_CORE_FILES 3539 #define NUM_CORE_FILES 5 3540 #endif 3541 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3542 static int num_cores = NUM_CORE_FILES; 3543 3544 static int 3545 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3546 { 3547 int error; 3548 int new_val; 3549 3550 new_val = num_cores; 3551 error = sysctl_handle_int(oidp, &new_val, 0, req); 3552 if (error != 0 || req->newptr == NULL) 3553 return (error); 3554 if (new_val > MAX_NUM_CORE_FILES) 3555 new_val = MAX_NUM_CORE_FILES; 3556 if (new_val < 0) 3557 new_val = 0; 3558 num_cores = new_val; 3559 return (0); 3560 } 3561 SYSCTL_PROC(_debug, OID_AUTO, ncores, 3562 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, sizeof(int), 3563 sysctl_debug_num_cores_check, "I", 3564 "Maximum number of generated process corefiles while using index format"); 3565 3566 #define GZIP_SUFFIX ".gz" 3567 #define ZSTD_SUFFIX ".zst" 3568 3569 int compress_user_cores = 0; 3570 3571 static int 3572 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3573 { 3574 int error, val; 3575 3576 val = compress_user_cores; 3577 error = sysctl_handle_int(oidp, &val, 0, req); 3578 if (error != 0 || req->newptr == NULL) 3579 return (error); 3580 if (val != 0 && !compressor_avail(val)) 3581 return (EINVAL); 3582 compress_user_cores = val; 3583 return (error); 3584 } 3585 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, 3586 CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3587 sysctl_compress_user_cores, "I", 3588 "Enable compression of user corefiles (" 3589 __XSTRING(COMPRESS_GZIP) " = gzip, " 3590 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3591 3592 int compress_user_cores_level = 6; 3593 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3594 &compress_user_cores_level, 0, 3595 "Corefile compression level"); 3596 3597 /* 3598 * Protect the access to corefilename[] by allproc_lock. 3599 */ 3600 #define corefilename_lock allproc_lock 3601 3602 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3603 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3604 3605 static int 3606 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3607 { 3608 int error; 3609 3610 sx_xlock(&corefilename_lock); 3611 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3612 req); 3613 sx_xunlock(&corefilename_lock); 3614 3615 return (error); 3616 } 3617 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3618 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3619 "Process corefile name format string"); 3620 3621 static void 3622 vnode_close_locked(struct thread *td, struct vnode *vp) 3623 { 3624 3625 VOP_UNLOCK(vp); 3626 vn_close(vp, FWRITE, td->td_ucred, td); 3627 } 3628 3629 /* 3630 * If the core format has a %I in it, then we need to check 3631 * for existing corefiles before defining a name. 3632 * To do this we iterate over 0..ncores to find a 3633 * non-existing core file name to use. If all core files are 3634 * already used we choose the oldest one. 3635 */ 3636 static int 3637 corefile_open_last(struct thread *td, char *name, int indexpos, 3638 int indexlen, int ncores, struct vnode **vpp) 3639 { 3640 struct vnode *oldvp, *nextvp, *vp; 3641 struct vattr vattr; 3642 struct nameidata nd; 3643 int error, i, flags, oflags, cmode; 3644 char ch; 3645 struct timespec lasttime; 3646 3647 nextvp = oldvp = NULL; 3648 cmode = S_IRUSR | S_IWUSR; 3649 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3650 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3651 3652 for (i = 0; i < ncores; i++) { 3653 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3654 3655 ch = name[indexpos + indexlen]; 3656 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3657 i); 3658 name[indexpos + indexlen] = ch; 3659 3660 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name); 3661 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3662 NULL); 3663 if (error != 0) 3664 break; 3665 3666 vp = nd.ni_vp; 3667 NDFREE_PNBUF(&nd); 3668 if ((flags & O_CREAT) == O_CREAT) { 3669 nextvp = vp; 3670 break; 3671 } 3672 3673 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3674 if (error != 0) { 3675 vnode_close_locked(td, vp); 3676 break; 3677 } 3678 3679 if (oldvp == NULL || 3680 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3681 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3682 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3683 if (oldvp != NULL) 3684 vn_close(oldvp, FWRITE, td->td_ucred, td); 3685 oldvp = vp; 3686 VOP_UNLOCK(oldvp); 3687 lasttime = vattr.va_mtime; 3688 } else { 3689 vnode_close_locked(td, vp); 3690 } 3691 } 3692 3693 if (oldvp != NULL) { 3694 if (nextvp == NULL) { 3695 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3696 error = EFAULT; 3697 vn_close(oldvp, FWRITE, td->td_ucred, td); 3698 } else { 3699 nextvp = oldvp; 3700 error = vn_lock(nextvp, LK_EXCLUSIVE); 3701 if (error != 0) { 3702 vn_close(nextvp, FWRITE, td->td_ucred, 3703 td); 3704 nextvp = NULL; 3705 } 3706 } 3707 } else { 3708 vn_close(oldvp, FWRITE, td->td_ucred, td); 3709 } 3710 } 3711 if (error != 0) { 3712 if (nextvp != NULL) 3713 vnode_close_locked(td, oldvp); 3714 } else { 3715 *vpp = nextvp; 3716 } 3717 3718 return (error); 3719 } 3720 3721 /* 3722 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3723 * Expand the name described in corefilename, using name, uid, and pid 3724 * and open/create core file. 3725 * corefilename is a printf-like string, with three format specifiers: 3726 * %N name of process ("name") 3727 * %P process id (pid) 3728 * %U user id (uid) 3729 * For example, "%N.core" is the default; they can be disabled completely 3730 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3731 * This is controlled by the sysctl variable kern.corefile (see above). 3732 */ 3733 static int 3734 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3735 int compress, int signum, struct vnode **vpp, char **namep) 3736 { 3737 struct sbuf sb; 3738 struct nameidata nd; 3739 const char *format; 3740 char *hostname, *name; 3741 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3742 3743 hostname = NULL; 3744 format = corefilename; 3745 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3746 indexlen = 0; 3747 indexpos = -1; 3748 ncores = num_cores; 3749 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3750 sx_slock(&corefilename_lock); 3751 for (i = 0; format[i] != '\0'; i++) { 3752 switch (format[i]) { 3753 case '%': /* Format character */ 3754 i++; 3755 switch (format[i]) { 3756 case '%': 3757 sbuf_putc(&sb, '%'); 3758 break; 3759 case 'H': /* hostname */ 3760 if (hostname == NULL) { 3761 hostname = malloc(MAXHOSTNAMELEN, 3762 M_TEMP, M_WAITOK); 3763 } 3764 getcredhostname(td->td_ucred, hostname, 3765 MAXHOSTNAMELEN); 3766 sbuf_printf(&sb, "%s", hostname); 3767 break; 3768 case 'I': /* autoincrementing index */ 3769 if (indexpos != -1) { 3770 sbuf_printf(&sb, "%%I"); 3771 break; 3772 } 3773 3774 indexpos = sbuf_len(&sb); 3775 sbuf_printf(&sb, "%u", ncores - 1); 3776 indexlen = sbuf_len(&sb) - indexpos; 3777 break; 3778 case 'N': /* process name */ 3779 sbuf_printf(&sb, "%s", comm); 3780 break; 3781 case 'P': /* process id */ 3782 sbuf_printf(&sb, "%u", pid); 3783 break; 3784 case 'S': /* signal number */ 3785 sbuf_printf(&sb, "%i", signum); 3786 break; 3787 case 'U': /* user id */ 3788 sbuf_printf(&sb, "%u", uid); 3789 break; 3790 default: 3791 log(LOG_ERR, 3792 "Unknown format character %c in " 3793 "corename `%s'\n", format[i], format); 3794 break; 3795 } 3796 break; 3797 default: 3798 sbuf_putc(&sb, format[i]); 3799 break; 3800 } 3801 } 3802 sx_sunlock(&corefilename_lock); 3803 free(hostname, M_TEMP); 3804 if (compress == COMPRESS_GZIP) 3805 sbuf_printf(&sb, GZIP_SUFFIX); 3806 else if (compress == COMPRESS_ZSTD) 3807 sbuf_printf(&sb, ZSTD_SUFFIX); 3808 if (sbuf_error(&sb) != 0) { 3809 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3810 "long\n", (long)pid, comm, (u_long)uid); 3811 sbuf_delete(&sb); 3812 free(name, M_TEMP); 3813 return (ENOMEM); 3814 } 3815 sbuf_finish(&sb); 3816 sbuf_delete(&sb); 3817 3818 if (indexpos != -1) { 3819 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3820 vpp); 3821 if (error != 0) { 3822 log(LOG_ERR, 3823 "pid %d (%s), uid (%u): Path `%s' failed " 3824 "on initial open test, error = %d\n", 3825 pid, comm, uid, name, error); 3826 } 3827 } else { 3828 cmode = S_IRUSR | S_IWUSR; 3829 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3830 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3831 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3832 if ((td->td_proc->p_flag & P_SUGID) != 0) 3833 flags |= O_EXCL; 3834 3835 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name); 3836 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3837 NULL); 3838 if (error == 0) { 3839 *vpp = nd.ni_vp; 3840 NDFREE_PNBUF(&nd); 3841 } 3842 } 3843 3844 if (error != 0) { 3845 #ifdef AUDIT 3846 audit_proc_coredump(td, name, error); 3847 #endif 3848 free(name, M_TEMP); 3849 return (error); 3850 } 3851 *namep = name; 3852 return (0); 3853 } 3854 3855 /* 3856 * Dump a process' core. The main routine does some 3857 * policy checking, and creates the name of the coredump; 3858 * then it passes on a vnode and a size limit to the process-specific 3859 * coredump routine if there is one; if there _is not_ one, it returns 3860 * ENOSYS; otherwise it returns the error from the process-specific routine. 3861 */ 3862 3863 static int 3864 coredump(struct thread *td) 3865 { 3866 struct proc *p = td->td_proc; 3867 struct ucred *cred = td->td_ucred; 3868 struct vnode *vp; 3869 struct flock lf; 3870 struct vattr vattr; 3871 size_t fullpathsize; 3872 int error, error1, locked; 3873 char *name; /* name of corefile */ 3874 void *rl_cookie; 3875 off_t limit; 3876 char *fullpath, *freepath = NULL; 3877 struct sbuf *sb; 3878 3879 PROC_LOCK_ASSERT(p, MA_OWNED); 3880 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3881 3882 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3883 (p->p_flag2 & P2_NOTRACE) != 0) { 3884 PROC_UNLOCK(p); 3885 return (EFAULT); 3886 } 3887 3888 /* 3889 * Note that the bulk of limit checking is done after 3890 * the corefile is created. The exception is if the limit 3891 * for corefiles is 0, in which case we don't bother 3892 * creating the corefile at all. This layout means that 3893 * a corefile is truncated instead of not being created, 3894 * if it is larger than the limit. 3895 */ 3896 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3897 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3898 PROC_UNLOCK(p); 3899 return (EFBIG); 3900 } 3901 PROC_UNLOCK(p); 3902 3903 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3904 compress_user_cores, p->p_sig, &vp, &name); 3905 if (error != 0) 3906 return (error); 3907 3908 /* 3909 * Don't dump to non-regular files or files with links. 3910 * Do not dump into system files. Effective user must own the corefile. 3911 */ 3912 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3913 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 3914 vattr.va_uid != cred->cr_uid) { 3915 VOP_UNLOCK(vp); 3916 error = EFAULT; 3917 goto out; 3918 } 3919 3920 VOP_UNLOCK(vp); 3921 3922 /* Postpone other writers, including core dumps of other processes. */ 3923 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3924 3925 lf.l_whence = SEEK_SET; 3926 lf.l_start = 0; 3927 lf.l_len = 0; 3928 lf.l_type = F_WRLCK; 3929 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3930 3931 VATTR_NULL(&vattr); 3932 vattr.va_size = 0; 3933 if (set_core_nodump_flag) 3934 vattr.va_flags = UF_NODUMP; 3935 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3936 VOP_SETATTR(vp, &vattr, cred); 3937 VOP_UNLOCK(vp); 3938 PROC_LOCK(p); 3939 p->p_acflag |= ACORE; 3940 PROC_UNLOCK(p); 3941 3942 if (p->p_sysent->sv_coredump != NULL) { 3943 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3944 } else { 3945 error = ENOSYS; 3946 } 3947 3948 if (locked) { 3949 lf.l_type = F_UNLCK; 3950 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3951 } 3952 vn_rangelock_unlock(vp, rl_cookie); 3953 3954 /* 3955 * Notify the userland helper that a process triggered a core dump. 3956 * This allows the helper to run an automated debugging session. 3957 */ 3958 if (error != 0 || coredump_devctl == 0) 3959 goto out; 3960 sb = sbuf_new_auto(); 3961 if (vn_fullpath_global(p->p_textvp, &fullpath, &freepath) != 0) 3962 goto out2; 3963 sbuf_printf(sb, "comm=\""); 3964 devctl_safe_quote_sb(sb, fullpath); 3965 free(freepath, M_TEMP); 3966 sbuf_printf(sb, "\" core=\""); 3967 3968 /* 3969 * We can't lookup core file vp directly. When we're replacing a core, and 3970 * other random times, we flush the name cache, so it will fail. Instead, 3971 * if the path of the core is relative, add the current dir in front if it. 3972 */ 3973 if (name[0] != '/') { 3974 fullpathsize = MAXPATHLEN; 3975 freepath = malloc(fullpathsize, M_TEMP, M_WAITOK); 3976 if (vn_getcwd(freepath, &fullpath, &fullpathsize) != 0) { 3977 free(freepath, M_TEMP); 3978 goto out2; 3979 } 3980 devctl_safe_quote_sb(sb, fullpath); 3981 free(freepath, M_TEMP); 3982 sbuf_putc(sb, '/'); 3983 } 3984 devctl_safe_quote_sb(sb, name); 3985 sbuf_printf(sb, "\""); 3986 if (sbuf_finish(sb) == 0) 3987 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 3988 out2: 3989 sbuf_delete(sb); 3990 out: 3991 error1 = vn_close(vp, FWRITE, cred, td); 3992 if (error == 0) 3993 error = error1; 3994 #ifdef AUDIT 3995 audit_proc_coredump(td, name, error); 3996 #endif 3997 free(name, M_TEMP); 3998 return (error); 3999 } 4000 4001 /* 4002 * Nonexistent system call-- signal process (may want to handle it). Flag 4003 * error in case process won't see signal immediately (blocked or ignored). 4004 */ 4005 #ifndef _SYS_SYSPROTO_H_ 4006 struct nosys_args { 4007 int dummy; 4008 }; 4009 #endif 4010 /* ARGSUSED */ 4011 int 4012 nosys(struct thread *td, struct nosys_args *args) 4013 { 4014 struct proc *p; 4015 4016 p = td->td_proc; 4017 4018 PROC_LOCK(p); 4019 tdsignal(td, SIGSYS); 4020 PROC_UNLOCK(p); 4021 if (kern_lognosys == 1 || kern_lognosys == 3) { 4022 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 4023 td->td_sa.code); 4024 } 4025 if (kern_lognosys == 2 || kern_lognosys == 3 || 4026 (p->p_pid == 1 && (kern_lognosys & 3) == 0)) { 4027 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 4028 td->td_sa.code); 4029 } 4030 return (ENOSYS); 4031 } 4032 4033 /* 4034 * Send a SIGIO or SIGURG signal to a process or process group using stored 4035 * credentials rather than those of the current process. 4036 */ 4037 void 4038 pgsigio(struct sigio **sigiop, int sig, int checkctty) 4039 { 4040 ksiginfo_t ksi; 4041 struct sigio *sigio; 4042 4043 ksiginfo_init(&ksi); 4044 ksi.ksi_signo = sig; 4045 ksi.ksi_code = SI_KERNEL; 4046 4047 SIGIO_LOCK(); 4048 sigio = *sigiop; 4049 if (sigio == NULL) { 4050 SIGIO_UNLOCK(); 4051 return; 4052 } 4053 if (sigio->sio_pgid > 0) { 4054 PROC_LOCK(sigio->sio_proc); 4055 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 4056 kern_psignal(sigio->sio_proc, sig); 4057 PROC_UNLOCK(sigio->sio_proc); 4058 } else if (sigio->sio_pgid < 0) { 4059 struct proc *p; 4060 4061 PGRP_LOCK(sigio->sio_pgrp); 4062 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 4063 PROC_LOCK(p); 4064 if (p->p_state == PRS_NORMAL && 4065 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 4066 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 4067 kern_psignal(p, sig); 4068 PROC_UNLOCK(p); 4069 } 4070 PGRP_UNLOCK(sigio->sio_pgrp); 4071 } 4072 SIGIO_UNLOCK(); 4073 } 4074 4075 static int 4076 filt_sigattach(struct knote *kn) 4077 { 4078 struct proc *p = curproc; 4079 4080 kn->kn_ptr.p_proc = p; 4081 kn->kn_flags |= EV_CLEAR; /* automatically set */ 4082 4083 knlist_add(p->p_klist, kn, 0); 4084 4085 return (0); 4086 } 4087 4088 static void 4089 filt_sigdetach(struct knote *kn) 4090 { 4091 struct proc *p = kn->kn_ptr.p_proc; 4092 4093 knlist_remove(p->p_klist, kn, 0); 4094 } 4095 4096 /* 4097 * signal knotes are shared with proc knotes, so we apply a mask to 4098 * the hint in order to differentiate them from process hints. This 4099 * could be avoided by using a signal-specific knote list, but probably 4100 * isn't worth the trouble. 4101 */ 4102 static int 4103 filt_signal(struct knote *kn, long hint) 4104 { 4105 4106 if (hint & NOTE_SIGNAL) { 4107 hint &= ~NOTE_SIGNAL; 4108 4109 if (kn->kn_id == hint) 4110 kn->kn_data++; 4111 } 4112 return (kn->kn_data != 0); 4113 } 4114 4115 struct sigacts * 4116 sigacts_alloc(void) 4117 { 4118 struct sigacts *ps; 4119 4120 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 4121 refcount_init(&ps->ps_refcnt, 1); 4122 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 4123 return (ps); 4124 } 4125 4126 void 4127 sigacts_free(struct sigacts *ps) 4128 { 4129 4130 if (refcount_release(&ps->ps_refcnt) == 0) 4131 return; 4132 mtx_destroy(&ps->ps_mtx); 4133 free(ps, M_SUBPROC); 4134 } 4135 4136 struct sigacts * 4137 sigacts_hold(struct sigacts *ps) 4138 { 4139 4140 refcount_acquire(&ps->ps_refcnt); 4141 return (ps); 4142 } 4143 4144 void 4145 sigacts_copy(struct sigacts *dest, struct sigacts *src) 4146 { 4147 4148 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 4149 mtx_lock(&src->ps_mtx); 4150 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 4151 mtx_unlock(&src->ps_mtx); 4152 } 4153 4154 int 4155 sigacts_shared(struct sigacts *ps) 4156 { 4157 4158 return (ps->ps_refcnt > 1); 4159 } 4160 4161 void 4162 sig_drop_caught(struct proc *p) 4163 { 4164 int sig; 4165 struct sigacts *ps; 4166 4167 ps = p->p_sigacts; 4168 PROC_LOCK_ASSERT(p, MA_OWNED); 4169 mtx_assert(&ps->ps_mtx, MA_OWNED); 4170 SIG_FOREACH(sig, &ps->ps_sigcatch) { 4171 sigdflt(ps, sig); 4172 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 4173 sigqueue_delete_proc(p, sig); 4174 } 4175 } 4176 4177 static void 4178 sigfastblock_failed(struct thread *td, bool sendsig, bool write) 4179 { 4180 ksiginfo_t ksi; 4181 4182 /* 4183 * Prevent further fetches and SIGSEGVs, allowing thread to 4184 * issue syscalls despite corruption. 4185 */ 4186 sigfastblock_clear(td); 4187 4188 if (!sendsig) 4189 return; 4190 ksiginfo_init_trap(&ksi); 4191 ksi.ksi_signo = SIGSEGV; 4192 ksi.ksi_code = write ? SEGV_ACCERR : SEGV_MAPERR; 4193 ksi.ksi_addr = td->td_sigblock_ptr; 4194 trapsignal(td, &ksi); 4195 } 4196 4197 static bool 4198 sigfastblock_fetch_sig(struct thread *td, bool sendsig, uint32_t *valp) 4199 { 4200 uint32_t res; 4201 4202 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4203 return (true); 4204 if (fueword32((void *)td->td_sigblock_ptr, &res) == -1) { 4205 sigfastblock_failed(td, sendsig, false); 4206 return (false); 4207 } 4208 *valp = res; 4209 td->td_sigblock_val = res & ~SIGFASTBLOCK_FLAGS; 4210 return (true); 4211 } 4212 4213 static void 4214 sigfastblock_resched(struct thread *td, bool resched) 4215 { 4216 struct proc *p; 4217 4218 if (resched) { 4219 p = td->td_proc; 4220 PROC_LOCK(p); 4221 reschedule_signals(p, td->td_sigmask, 0); 4222 PROC_UNLOCK(p); 4223 } 4224 thread_lock(td); 4225 td->td_flags |= TDF_ASTPENDING | TDF_NEEDSIGCHK; 4226 thread_unlock(td); 4227 } 4228 4229 int 4230 sys_sigfastblock(struct thread *td, struct sigfastblock_args *uap) 4231 { 4232 struct proc *p; 4233 int error, res; 4234 uint32_t oldval; 4235 4236 error = 0; 4237 p = td->td_proc; 4238 switch (uap->cmd) { 4239 case SIGFASTBLOCK_SETPTR: 4240 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 4241 error = EBUSY; 4242 break; 4243 } 4244 if (((uintptr_t)(uap->ptr) & (sizeof(uint32_t) - 1)) != 0) { 4245 error = EINVAL; 4246 break; 4247 } 4248 td->td_pflags |= TDP_SIGFASTBLOCK; 4249 td->td_sigblock_ptr = uap->ptr; 4250 break; 4251 4252 case SIGFASTBLOCK_UNBLOCK: 4253 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4254 error = EINVAL; 4255 break; 4256 } 4257 4258 for (;;) { 4259 res = casueword32(td->td_sigblock_ptr, 4260 SIGFASTBLOCK_PEND, &oldval, 0); 4261 if (res == -1) { 4262 error = EFAULT; 4263 sigfastblock_failed(td, false, true); 4264 break; 4265 } 4266 if (res == 0) 4267 break; 4268 MPASS(res == 1); 4269 if (oldval != SIGFASTBLOCK_PEND) { 4270 error = EBUSY; 4271 break; 4272 } 4273 error = thread_check_susp(td, false); 4274 if (error != 0) 4275 break; 4276 } 4277 if (error != 0) 4278 break; 4279 4280 /* 4281 * td_sigblock_val is cleared there, but not on a 4282 * syscall exit. The end effect is that a single 4283 * interruptible sleep, while user sigblock word is 4284 * set, might return EINTR or ERESTART to usermode 4285 * without delivering signal. All further sleeps, 4286 * until userspace clears the word and does 4287 * sigfastblock(UNBLOCK), observe current word and no 4288 * longer get interrupted. It is slight 4289 * non-conformance, with alternative to have read the 4290 * sigblock word on each syscall entry. 4291 */ 4292 td->td_sigblock_val = 0; 4293 4294 /* 4295 * Rely on normal ast mechanism to deliver pending 4296 * signals to current thread. But notify others about 4297 * fake unblock. 4298 */ 4299 sigfastblock_resched(td, error == 0 && p->p_numthreads != 1); 4300 4301 break; 4302 4303 case SIGFASTBLOCK_UNSETPTR: 4304 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4305 error = EINVAL; 4306 break; 4307 } 4308 if (!sigfastblock_fetch_sig(td, false, &oldval)) { 4309 error = EFAULT; 4310 break; 4311 } 4312 if (oldval != 0 && oldval != SIGFASTBLOCK_PEND) { 4313 error = EBUSY; 4314 break; 4315 } 4316 sigfastblock_clear(td); 4317 break; 4318 4319 default: 4320 error = EINVAL; 4321 break; 4322 } 4323 return (error); 4324 } 4325 4326 void 4327 sigfastblock_clear(struct thread *td) 4328 { 4329 bool resched; 4330 4331 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4332 return; 4333 td->td_sigblock_val = 0; 4334 resched = (td->td_pflags & TDP_SIGFASTPENDING) != 0 || 4335 SIGPENDING(td); 4336 td->td_pflags &= ~(TDP_SIGFASTBLOCK | TDP_SIGFASTPENDING); 4337 sigfastblock_resched(td, resched); 4338 } 4339 4340 void 4341 sigfastblock_fetch(struct thread *td) 4342 { 4343 uint32_t val; 4344 4345 (void)sigfastblock_fetch_sig(td, true, &val); 4346 } 4347 4348 static void 4349 sigfastblock_setpend1(struct thread *td) 4350 { 4351 int res; 4352 uint32_t oldval; 4353 4354 if ((td->td_pflags & TDP_SIGFASTPENDING) == 0) 4355 return; 4356 res = fueword32((void *)td->td_sigblock_ptr, &oldval); 4357 if (res == -1) { 4358 sigfastblock_failed(td, true, false); 4359 return; 4360 } 4361 for (;;) { 4362 res = casueword32(td->td_sigblock_ptr, oldval, &oldval, 4363 oldval | SIGFASTBLOCK_PEND); 4364 if (res == -1) { 4365 sigfastblock_failed(td, true, true); 4366 return; 4367 } 4368 if (res == 0) { 4369 td->td_sigblock_val = oldval & ~SIGFASTBLOCK_FLAGS; 4370 td->td_pflags &= ~TDP_SIGFASTPENDING; 4371 break; 4372 } 4373 MPASS(res == 1); 4374 if (thread_check_susp(td, false) != 0) 4375 break; 4376 } 4377 } 4378 4379 void 4380 sigfastblock_setpend(struct thread *td, bool resched) 4381 { 4382 struct proc *p; 4383 4384 sigfastblock_setpend1(td); 4385 if (resched) { 4386 p = td->td_proc; 4387 PROC_LOCK(p); 4388 reschedule_signals(p, fastblock_mask, SIGPROCMASK_FASTBLK); 4389 PROC_UNLOCK(p); 4390 } 4391 } 4392