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, timevalid = 0; 1262 sbintime_t sbt, precision, tsbt; 1263 struct timespec ts; 1264 bool traced; 1265 1266 p = td->td_proc; 1267 error = 0; 1268 traced = false; 1269 1270 /* Ensure the sigfastblock value is up to date. */ 1271 sigfastblock_fetch(td); 1272 1273 if (timeout != NULL) { 1274 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1275 timevalid = 1; 1276 ts = *timeout; 1277 if (ts.tv_sec < INT32_MAX / 2) { 1278 tsbt = tstosbt(ts); 1279 precision = tsbt; 1280 precision >>= tc_precexp; 1281 if (TIMESEL(&sbt, tsbt)) 1282 sbt += tc_tick_sbt; 1283 sbt += tsbt; 1284 } else 1285 precision = sbt = 0; 1286 } 1287 } else 1288 precision = sbt = 0; 1289 ksiginfo_init(ksi); 1290 /* Some signals can not be waited for. */ 1291 SIG_CANTMASK(waitset); 1292 ps = p->p_sigacts; 1293 PROC_LOCK(p); 1294 saved_mask = td->td_sigmask; 1295 SIGSETNAND(td->td_sigmask, waitset); 1296 if ((p->p_sysent->sv_flags & SV_SIG_DISCIGN) != 0 || 1297 !kern_sig_discard_ign) { 1298 thread_lock(td); 1299 td->td_flags |= TDF_SIGWAIT; 1300 thread_unlock(td); 1301 } 1302 for (;;) { 1303 mtx_lock(&ps->ps_mtx); 1304 sig = cursig(td); 1305 mtx_unlock(&ps->ps_mtx); 1306 KASSERT(sig >= 0, ("sig %d", sig)); 1307 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1308 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1309 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1310 error = 0; 1311 break; 1312 } 1313 } 1314 1315 if (error != 0) 1316 break; 1317 1318 /* 1319 * POSIX says this must be checked after looking for pending 1320 * signals. 1321 */ 1322 if (timeout != NULL && !timevalid) { 1323 error = EINVAL; 1324 break; 1325 } 1326 1327 if (traced) { 1328 error = EINTR; 1329 break; 1330 } 1331 1332 error = msleep_sbt(&p->p_sigacts, &p->p_mtx, PPAUSE | PCATCH, 1333 "sigwait", sbt, precision, C_ABSOLUTE); 1334 1335 /* The syscalls can not be restarted. */ 1336 if (error == ERESTART) 1337 error = EINTR; 1338 1339 /* 1340 * If PTRACE_SCE or PTRACE_SCX were set after 1341 * userspace entered the syscall, return spurious 1342 * EINTR after wait was done. Only do this as last 1343 * resort after rechecking for possible queued signals 1344 * and expired timeouts. 1345 */ 1346 if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0) 1347 traced = true; 1348 } 1349 thread_lock(td); 1350 td->td_flags &= ~TDF_SIGWAIT; 1351 thread_unlock(td); 1352 1353 new_block = saved_mask; 1354 SIGSETNAND(new_block, td->td_sigmask); 1355 td->td_sigmask = saved_mask; 1356 /* 1357 * Fewer signals can be delivered to us, reschedule signal 1358 * notification. 1359 */ 1360 if (p->p_numthreads != 1) 1361 reschedule_signals(p, new_block, 0); 1362 1363 if (error == 0) { 1364 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1365 1366 if (ksi->ksi_code == SI_TIMER) 1367 itimer_accept(p, ksi->ksi_timerid, ksi); 1368 1369 #ifdef KTRACE 1370 if (KTRPOINT(td, KTR_PSIG)) { 1371 sig_t action; 1372 1373 mtx_lock(&ps->ps_mtx); 1374 action = ps->ps_sigact[_SIG_IDX(sig)]; 1375 mtx_unlock(&ps->ps_mtx); 1376 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1377 } 1378 #endif 1379 if (sig == SIGKILL) { 1380 proc_td_siginfo_capture(td, &ksi->ksi_info); 1381 sigexit(td, sig); 1382 } 1383 } 1384 PROC_UNLOCK(p); 1385 return (error); 1386 } 1387 1388 #ifndef _SYS_SYSPROTO_H_ 1389 struct sigpending_args { 1390 sigset_t *set; 1391 }; 1392 #endif 1393 int 1394 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1395 { 1396 struct proc *p = td->td_proc; 1397 sigset_t pending; 1398 1399 PROC_LOCK(p); 1400 pending = p->p_sigqueue.sq_signals; 1401 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1402 PROC_UNLOCK(p); 1403 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1404 } 1405 1406 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1407 #ifndef _SYS_SYSPROTO_H_ 1408 struct osigpending_args { 1409 int dummy; 1410 }; 1411 #endif 1412 int 1413 osigpending(struct thread *td, struct osigpending_args *uap) 1414 { 1415 struct proc *p = td->td_proc; 1416 sigset_t pending; 1417 1418 PROC_LOCK(p); 1419 pending = p->p_sigqueue.sq_signals; 1420 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1421 PROC_UNLOCK(p); 1422 SIG2OSIG(pending, td->td_retval[0]); 1423 return (0); 1424 } 1425 #endif /* COMPAT_43 */ 1426 1427 #if defined(COMPAT_43) 1428 /* 1429 * Generalized interface signal handler, 4.3-compatible. 1430 */ 1431 #ifndef _SYS_SYSPROTO_H_ 1432 struct osigvec_args { 1433 int signum; 1434 struct sigvec *nsv; 1435 struct sigvec *osv; 1436 }; 1437 #endif 1438 /* ARGSUSED */ 1439 int 1440 osigvec(struct thread *td, struct osigvec_args *uap) 1441 { 1442 struct sigvec vec; 1443 struct sigaction nsa, osa; 1444 struct sigaction *nsap, *osap; 1445 int error; 1446 1447 if (uap->signum <= 0 || uap->signum >= ONSIG) 1448 return (EINVAL); 1449 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1450 osap = (uap->osv != NULL) ? &osa : NULL; 1451 if (nsap) { 1452 error = copyin(uap->nsv, &vec, sizeof(vec)); 1453 if (error) 1454 return (error); 1455 nsap->sa_handler = vec.sv_handler; 1456 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1457 nsap->sa_flags = vec.sv_flags; 1458 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1459 } 1460 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1461 if (osap && !error) { 1462 vec.sv_handler = osap->sa_handler; 1463 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1464 vec.sv_flags = osap->sa_flags; 1465 vec.sv_flags &= ~SA_NOCLDWAIT; 1466 vec.sv_flags ^= SA_RESTART; 1467 error = copyout(&vec, uap->osv, sizeof(vec)); 1468 } 1469 return (error); 1470 } 1471 1472 #ifndef _SYS_SYSPROTO_H_ 1473 struct osigblock_args { 1474 int mask; 1475 }; 1476 #endif 1477 int 1478 osigblock(struct thread *td, struct osigblock_args *uap) 1479 { 1480 sigset_t set, oset; 1481 1482 OSIG2SIG(uap->mask, set); 1483 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1484 SIG2OSIG(oset, td->td_retval[0]); 1485 return (0); 1486 } 1487 1488 #ifndef _SYS_SYSPROTO_H_ 1489 struct osigsetmask_args { 1490 int mask; 1491 }; 1492 #endif 1493 int 1494 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1495 { 1496 sigset_t set, oset; 1497 1498 OSIG2SIG(uap->mask, set); 1499 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1500 SIG2OSIG(oset, td->td_retval[0]); 1501 return (0); 1502 } 1503 #endif /* COMPAT_43 */ 1504 1505 /* 1506 * Suspend calling thread until signal, providing mask to be set in the 1507 * meantime. 1508 */ 1509 #ifndef _SYS_SYSPROTO_H_ 1510 struct sigsuspend_args { 1511 const sigset_t *sigmask; 1512 }; 1513 #endif 1514 /* ARGSUSED */ 1515 int 1516 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1517 { 1518 sigset_t mask; 1519 int error; 1520 1521 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1522 if (error) 1523 return (error); 1524 return (kern_sigsuspend(td, mask)); 1525 } 1526 1527 int 1528 kern_sigsuspend(struct thread *td, sigset_t mask) 1529 { 1530 struct proc *p = td->td_proc; 1531 int has_sig, sig; 1532 1533 /* Ensure the sigfastblock value is up to date. */ 1534 sigfastblock_fetch(td); 1535 1536 /* 1537 * When returning from sigsuspend, we want 1538 * the old mask to be restored after the 1539 * signal handler has finished. Thus, we 1540 * save it here and mark the sigacts structure 1541 * to indicate this. 1542 */ 1543 PROC_LOCK(p); 1544 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1545 SIGPROCMASK_PROC_LOCKED); 1546 td->td_pflags |= TDP_OLDMASK; 1547 1548 /* 1549 * Process signals now. Otherwise, we can get spurious wakeup 1550 * due to signal entered process queue, but delivered to other 1551 * thread. But sigsuspend should return only on signal 1552 * delivery. 1553 */ 1554 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1555 for (has_sig = 0; !has_sig;) { 1556 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1557 0) == 0) 1558 /* void */; 1559 thread_suspend_check(0); 1560 mtx_lock(&p->p_sigacts->ps_mtx); 1561 while ((sig = cursig(td)) != 0) { 1562 KASSERT(sig >= 0, ("sig %d", sig)); 1563 has_sig += postsig(sig); 1564 } 1565 mtx_unlock(&p->p_sigacts->ps_mtx); 1566 1567 /* 1568 * If PTRACE_SCE or PTRACE_SCX were set after 1569 * userspace entered the syscall, return spurious 1570 * EINTR. 1571 */ 1572 if ((p->p_ptevents & PTRACE_SYSCALL) != 0) 1573 has_sig += 1; 1574 } 1575 PROC_UNLOCK(p); 1576 td->td_errno = EINTR; 1577 td->td_pflags |= TDP_NERRNO; 1578 return (EJUSTRETURN); 1579 } 1580 1581 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1582 /* 1583 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1584 * convention: libc stub passes mask, not pointer, to save a copyin. 1585 */ 1586 #ifndef _SYS_SYSPROTO_H_ 1587 struct osigsuspend_args { 1588 osigset_t mask; 1589 }; 1590 #endif 1591 /* ARGSUSED */ 1592 int 1593 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1594 { 1595 sigset_t mask; 1596 1597 OSIG2SIG(uap->mask, mask); 1598 return (kern_sigsuspend(td, mask)); 1599 } 1600 #endif /* COMPAT_43 */ 1601 1602 #if defined(COMPAT_43) 1603 #ifndef _SYS_SYSPROTO_H_ 1604 struct osigstack_args { 1605 struct sigstack *nss; 1606 struct sigstack *oss; 1607 }; 1608 #endif 1609 /* ARGSUSED */ 1610 int 1611 osigstack(struct thread *td, struct osigstack_args *uap) 1612 { 1613 struct sigstack nss, oss; 1614 int error = 0; 1615 1616 if (uap->nss != NULL) { 1617 error = copyin(uap->nss, &nss, sizeof(nss)); 1618 if (error) 1619 return (error); 1620 } 1621 oss.ss_sp = td->td_sigstk.ss_sp; 1622 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1623 if (uap->nss != NULL) { 1624 td->td_sigstk.ss_sp = nss.ss_sp; 1625 td->td_sigstk.ss_size = 0; 1626 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1627 td->td_pflags |= TDP_ALTSTACK; 1628 } 1629 if (uap->oss != NULL) 1630 error = copyout(&oss, uap->oss, sizeof(oss)); 1631 1632 return (error); 1633 } 1634 #endif /* COMPAT_43 */ 1635 1636 #ifndef _SYS_SYSPROTO_H_ 1637 struct sigaltstack_args { 1638 stack_t *ss; 1639 stack_t *oss; 1640 }; 1641 #endif 1642 /* ARGSUSED */ 1643 int 1644 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1645 { 1646 stack_t ss, oss; 1647 int error; 1648 1649 if (uap->ss != NULL) { 1650 error = copyin(uap->ss, &ss, sizeof(ss)); 1651 if (error) 1652 return (error); 1653 } 1654 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1655 (uap->oss != NULL) ? &oss : NULL); 1656 if (error) 1657 return (error); 1658 if (uap->oss != NULL) 1659 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1660 return (error); 1661 } 1662 1663 int 1664 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1665 { 1666 struct proc *p = td->td_proc; 1667 int oonstack; 1668 1669 oonstack = sigonstack(cpu_getstack(td)); 1670 1671 if (oss != NULL) { 1672 *oss = td->td_sigstk; 1673 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1674 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1675 } 1676 1677 if (ss != NULL) { 1678 if (oonstack) 1679 return (EPERM); 1680 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1681 return (EINVAL); 1682 if (!(ss->ss_flags & SS_DISABLE)) { 1683 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1684 return (ENOMEM); 1685 1686 td->td_sigstk = *ss; 1687 td->td_pflags |= TDP_ALTSTACK; 1688 } else { 1689 td->td_pflags &= ~TDP_ALTSTACK; 1690 } 1691 } 1692 return (0); 1693 } 1694 1695 struct killpg1_ctx { 1696 struct thread *td; 1697 ksiginfo_t *ksi; 1698 int sig; 1699 bool sent; 1700 bool found; 1701 int ret; 1702 }; 1703 1704 static void 1705 killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg) 1706 { 1707 int err; 1708 1709 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 || 1710 (notself && p == arg->td->td_proc) || p->p_state == PRS_NEW) 1711 return; 1712 PROC_LOCK(p); 1713 err = p_cansignal(arg->td, p, arg->sig); 1714 if (err == 0 && arg->sig != 0) 1715 pksignal(p, arg->sig, arg->ksi); 1716 PROC_UNLOCK(p); 1717 if (err != ESRCH) 1718 arg->found = true; 1719 if (err == 0) 1720 arg->sent = true; 1721 else if (arg->ret == 0 && err != ESRCH && err != EPERM) 1722 arg->ret = err; 1723 } 1724 1725 /* 1726 * Common code for kill process group/broadcast kill. 1727 * cp is calling process. 1728 */ 1729 static int 1730 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1731 { 1732 struct proc *p; 1733 struct pgrp *pgrp; 1734 struct killpg1_ctx arg; 1735 1736 arg.td = td; 1737 arg.ksi = ksi; 1738 arg.sig = sig; 1739 arg.sent = false; 1740 arg.found = false; 1741 arg.ret = 0; 1742 if (all) { 1743 /* 1744 * broadcast 1745 */ 1746 sx_slock(&allproc_lock); 1747 FOREACH_PROC_IN_SYSTEM(p) { 1748 killpg1_sendsig(p, true, &arg); 1749 } 1750 sx_sunlock(&allproc_lock); 1751 } else { 1752 sx_slock(&proctree_lock); 1753 if (pgid == 0) { 1754 /* 1755 * zero pgid means send to my process group. 1756 */ 1757 pgrp = td->td_proc->p_pgrp; 1758 PGRP_LOCK(pgrp); 1759 } else { 1760 pgrp = pgfind(pgid); 1761 if (pgrp == NULL) { 1762 sx_sunlock(&proctree_lock); 1763 return (ESRCH); 1764 } 1765 } 1766 sx_sunlock(&proctree_lock); 1767 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1768 killpg1_sendsig(p, false, &arg); 1769 } 1770 PGRP_UNLOCK(pgrp); 1771 } 1772 MPASS(arg.ret != 0 || arg.found || !arg.sent); 1773 if (arg.ret == 0 && !arg.sent) 1774 arg.ret = arg.found ? EPERM : ESRCH; 1775 return (arg.ret); 1776 } 1777 1778 #ifndef _SYS_SYSPROTO_H_ 1779 struct kill_args { 1780 int pid; 1781 int signum; 1782 }; 1783 #endif 1784 /* ARGSUSED */ 1785 int 1786 sys_kill(struct thread *td, struct kill_args *uap) 1787 { 1788 1789 return (kern_kill(td, uap->pid, uap->signum)); 1790 } 1791 1792 int 1793 kern_kill(struct thread *td, pid_t pid, int signum) 1794 { 1795 ksiginfo_t ksi; 1796 struct proc *p; 1797 int error; 1798 1799 /* 1800 * A process in capability mode can send signals only to himself. 1801 * The main rationale behind this is that abort(3) is implemented as 1802 * kill(getpid(), SIGABRT). 1803 */ 1804 if (IN_CAPABILITY_MODE(td) && pid != td->td_proc->p_pid) 1805 return (ECAPMODE); 1806 1807 AUDIT_ARG_SIGNUM(signum); 1808 AUDIT_ARG_PID(pid); 1809 if ((u_int)signum > _SIG_MAXSIG) 1810 return (EINVAL); 1811 1812 ksiginfo_init(&ksi); 1813 ksi.ksi_signo = signum; 1814 ksi.ksi_code = SI_USER; 1815 ksi.ksi_pid = td->td_proc->p_pid; 1816 ksi.ksi_uid = td->td_ucred->cr_ruid; 1817 1818 if (pid > 0) { 1819 /* kill single process */ 1820 if ((p = pfind_any(pid)) == NULL) 1821 return (ESRCH); 1822 AUDIT_ARG_PROCESS(p); 1823 error = p_cansignal(td, p, signum); 1824 if (error == 0 && signum) 1825 pksignal(p, signum, &ksi); 1826 PROC_UNLOCK(p); 1827 return (error); 1828 } 1829 switch (pid) { 1830 case -1: /* broadcast signal */ 1831 return (killpg1(td, signum, 0, 1, &ksi)); 1832 case 0: /* signal own process group */ 1833 return (killpg1(td, signum, 0, 0, &ksi)); 1834 default: /* negative explicit process group */ 1835 return (killpg1(td, signum, -pid, 0, &ksi)); 1836 } 1837 /* NOTREACHED */ 1838 } 1839 1840 int 1841 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1842 { 1843 struct proc *p; 1844 int error; 1845 1846 AUDIT_ARG_SIGNUM(uap->signum); 1847 AUDIT_ARG_FD(uap->fd); 1848 if ((u_int)uap->signum > _SIG_MAXSIG) 1849 return (EINVAL); 1850 1851 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1852 if (error) 1853 return (error); 1854 AUDIT_ARG_PROCESS(p); 1855 error = p_cansignal(td, p, uap->signum); 1856 if (error == 0 && uap->signum) 1857 kern_psignal(p, uap->signum); 1858 PROC_UNLOCK(p); 1859 return (error); 1860 } 1861 1862 #if defined(COMPAT_43) 1863 #ifndef _SYS_SYSPROTO_H_ 1864 struct okillpg_args { 1865 int pgid; 1866 int signum; 1867 }; 1868 #endif 1869 /* ARGSUSED */ 1870 int 1871 okillpg(struct thread *td, struct okillpg_args *uap) 1872 { 1873 ksiginfo_t ksi; 1874 1875 AUDIT_ARG_SIGNUM(uap->signum); 1876 AUDIT_ARG_PID(uap->pgid); 1877 if ((u_int)uap->signum > _SIG_MAXSIG) 1878 return (EINVAL); 1879 1880 ksiginfo_init(&ksi); 1881 ksi.ksi_signo = uap->signum; 1882 ksi.ksi_code = SI_USER; 1883 ksi.ksi_pid = td->td_proc->p_pid; 1884 ksi.ksi_uid = td->td_ucred->cr_ruid; 1885 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1886 } 1887 #endif /* COMPAT_43 */ 1888 1889 #ifndef _SYS_SYSPROTO_H_ 1890 struct sigqueue_args { 1891 pid_t pid; 1892 int signum; 1893 /* union sigval */ void *value; 1894 }; 1895 #endif 1896 int 1897 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1898 { 1899 union sigval sv; 1900 1901 sv.sival_ptr = uap->value; 1902 1903 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1904 } 1905 1906 int 1907 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1908 { 1909 ksiginfo_t ksi; 1910 struct proc *p; 1911 int error; 1912 1913 if ((u_int)signum > _SIG_MAXSIG) 1914 return (EINVAL); 1915 1916 /* 1917 * Specification says sigqueue can only send signal to 1918 * single process. 1919 */ 1920 if (pid <= 0) 1921 return (EINVAL); 1922 1923 if ((p = pfind_any(pid)) == NULL) 1924 return (ESRCH); 1925 error = p_cansignal(td, p, signum); 1926 if (error == 0 && signum != 0) { 1927 ksiginfo_init(&ksi); 1928 ksi.ksi_flags = KSI_SIGQ; 1929 ksi.ksi_signo = signum; 1930 ksi.ksi_code = SI_QUEUE; 1931 ksi.ksi_pid = td->td_proc->p_pid; 1932 ksi.ksi_uid = td->td_ucred->cr_ruid; 1933 ksi.ksi_value = *value; 1934 error = pksignal(p, ksi.ksi_signo, &ksi); 1935 } 1936 PROC_UNLOCK(p); 1937 return (error); 1938 } 1939 1940 /* 1941 * Send a signal to a process group. 1942 */ 1943 void 1944 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1945 { 1946 struct pgrp *pgrp; 1947 1948 if (pgid != 0) { 1949 sx_slock(&proctree_lock); 1950 pgrp = pgfind(pgid); 1951 sx_sunlock(&proctree_lock); 1952 if (pgrp != NULL) { 1953 pgsignal(pgrp, sig, 0, ksi); 1954 PGRP_UNLOCK(pgrp); 1955 } 1956 } 1957 } 1958 1959 /* 1960 * Send a signal to a process group. If checktty is 1, 1961 * limit to members which have a controlling terminal. 1962 */ 1963 void 1964 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1965 { 1966 struct proc *p; 1967 1968 if (pgrp) { 1969 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1970 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1971 PROC_LOCK(p); 1972 if (p->p_state == PRS_NORMAL && 1973 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1974 pksignal(p, sig, ksi); 1975 PROC_UNLOCK(p); 1976 } 1977 } 1978 } 1979 1980 /* 1981 * Recalculate the signal mask and reset the signal disposition after 1982 * usermode frame for delivery is formed. Should be called after 1983 * mach-specific routine, because sysent->sv_sendsig() needs correct 1984 * ps_siginfo and signal mask. 1985 */ 1986 static void 1987 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1988 { 1989 sigset_t mask; 1990 1991 mtx_assert(&ps->ps_mtx, MA_OWNED); 1992 td->td_ru.ru_nsignals++; 1993 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1994 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1995 SIGADDSET(mask, sig); 1996 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1997 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1998 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1999 sigdflt(ps, sig); 2000 } 2001 2002 /* 2003 * Send a signal caused by a trap to the current thread. If it will be 2004 * caught immediately, deliver it with correct code. Otherwise, post it 2005 * normally. 2006 */ 2007 void 2008 trapsignal(struct thread *td, ksiginfo_t *ksi) 2009 { 2010 struct sigacts *ps; 2011 struct proc *p; 2012 sigset_t sigmask; 2013 int sig; 2014 2015 p = td->td_proc; 2016 sig = ksi->ksi_signo; 2017 KASSERT(_SIG_VALID(sig), ("invalid signal")); 2018 2019 sigfastblock_fetch(td); 2020 PROC_LOCK(p); 2021 ps = p->p_sigacts; 2022 mtx_lock(&ps->ps_mtx); 2023 sigmask = td->td_sigmask; 2024 if (td->td_sigblock_val != 0) 2025 SIGSETOR(sigmask, fastblock_mask); 2026 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 2027 !SIGISMEMBER(sigmask, sig)) { 2028 #ifdef KTRACE 2029 if (KTRPOINT(curthread, KTR_PSIG)) 2030 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 2031 &td->td_sigmask, ksi->ksi_code); 2032 #endif 2033 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 2034 ksi, &td->td_sigmask); 2035 postsig_done(sig, td, ps); 2036 mtx_unlock(&ps->ps_mtx); 2037 } else { 2038 /* 2039 * Avoid a possible infinite loop if the thread 2040 * masking the signal or process is ignoring the 2041 * signal. 2042 */ 2043 if (kern_forcesigexit && (SIGISMEMBER(sigmask, sig) || 2044 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2045 SIGDELSET(td->td_sigmask, sig); 2046 SIGDELSET(ps->ps_sigcatch, sig); 2047 SIGDELSET(ps->ps_sigignore, sig); 2048 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2049 td->td_pflags &= ~TDP_SIGFASTBLOCK; 2050 td->td_sigblock_val = 0; 2051 } 2052 mtx_unlock(&ps->ps_mtx); 2053 p->p_sig = sig; /* XXX to verify code */ 2054 tdsendsignal(p, td, sig, ksi); 2055 } 2056 PROC_UNLOCK(p); 2057 } 2058 2059 static struct thread * 2060 sigtd(struct proc *p, int sig, bool fast_sigblock) 2061 { 2062 struct thread *td, *signal_td; 2063 2064 PROC_LOCK_ASSERT(p, MA_OWNED); 2065 MPASS(!fast_sigblock || p == curproc); 2066 2067 /* 2068 * Check if current thread can handle the signal without 2069 * switching context to another thread. 2070 */ 2071 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig) && 2072 (!fast_sigblock || curthread->td_sigblock_val == 0)) 2073 return (curthread); 2074 signal_td = NULL; 2075 FOREACH_THREAD_IN_PROC(p, td) { 2076 if (!SIGISMEMBER(td->td_sigmask, sig) && (!fast_sigblock || 2077 td != curthread || td->td_sigblock_val == 0)) { 2078 signal_td = td; 2079 break; 2080 } 2081 } 2082 if (signal_td == NULL) 2083 signal_td = FIRST_THREAD_IN_PROC(p); 2084 return (signal_td); 2085 } 2086 2087 /* 2088 * Send the signal to the process. If the signal has an action, the action 2089 * is usually performed by the target process rather than the caller; we add 2090 * the signal to the set of pending signals for the process. 2091 * 2092 * Exceptions: 2093 * o When a stop signal is sent to a sleeping process that takes the 2094 * default action, the process is stopped without awakening it. 2095 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2096 * regardless of the signal action (eg, blocked or ignored). 2097 * 2098 * Other ignored signals are discarded immediately. 2099 * 2100 * NB: This function may be entered from the debugger via the "kill" DDB 2101 * command. There is little that can be done to mitigate the possibly messy 2102 * side effects of this unwise possibility. 2103 */ 2104 void 2105 kern_psignal(struct proc *p, int sig) 2106 { 2107 ksiginfo_t ksi; 2108 2109 ksiginfo_init(&ksi); 2110 ksi.ksi_signo = sig; 2111 ksi.ksi_code = SI_KERNEL; 2112 (void) tdsendsignal(p, NULL, sig, &ksi); 2113 } 2114 2115 int 2116 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2117 { 2118 2119 return (tdsendsignal(p, NULL, sig, ksi)); 2120 } 2121 2122 /* Utility function for finding a thread to send signal event to. */ 2123 int 2124 sigev_findtd(struct proc *p, struct sigevent *sigev, struct thread **ttd) 2125 { 2126 struct thread *td; 2127 2128 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2129 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2130 if (td == NULL) 2131 return (ESRCH); 2132 *ttd = td; 2133 } else { 2134 *ttd = NULL; 2135 PROC_LOCK(p); 2136 } 2137 return (0); 2138 } 2139 2140 void 2141 tdsignal(struct thread *td, int sig) 2142 { 2143 ksiginfo_t ksi; 2144 2145 ksiginfo_init(&ksi); 2146 ksi.ksi_signo = sig; 2147 ksi.ksi_code = SI_KERNEL; 2148 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2149 } 2150 2151 void 2152 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2153 { 2154 2155 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2156 } 2157 2158 static int 2159 sig_sleepq_abort(struct thread *td, int intrval) 2160 { 2161 THREAD_LOCK_ASSERT(td, MA_OWNED); 2162 2163 if (intrval == 0 && (td->td_flags & TDF_SIGWAIT) == 0) { 2164 thread_unlock(td); 2165 return (0); 2166 } 2167 return (sleepq_abort(td, intrval)); 2168 } 2169 2170 int 2171 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2172 { 2173 sig_t action; 2174 sigqueue_t *sigqueue; 2175 int prop; 2176 struct sigacts *ps; 2177 int intrval; 2178 int ret = 0; 2179 int wakeup_swapper; 2180 2181 MPASS(td == NULL || p == td->td_proc); 2182 PROC_LOCK_ASSERT(p, MA_OWNED); 2183 2184 if (!_SIG_VALID(sig)) 2185 panic("%s(): invalid signal %d", __func__, sig); 2186 2187 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2188 2189 /* 2190 * IEEE Std 1003.1-2001: return success when killing a zombie. 2191 */ 2192 if (p->p_state == PRS_ZOMBIE) { 2193 if (ksi && (ksi->ksi_flags & KSI_INS)) 2194 ksiginfo_tryfree(ksi); 2195 return (ret); 2196 } 2197 2198 ps = p->p_sigacts; 2199 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2200 prop = sigprop(sig); 2201 2202 if (td == NULL) { 2203 td = sigtd(p, sig, false); 2204 sigqueue = &p->p_sigqueue; 2205 } else 2206 sigqueue = &td->td_sigqueue; 2207 2208 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2209 2210 /* 2211 * If the signal is being ignored, then we forget about it 2212 * immediately, except when the target process executes 2213 * sigwait(). (Note: we don't set SIGCONT in ps_sigignore, 2214 * and if it is set to SIG_IGN, action will be SIG_DFL here.) 2215 */ 2216 mtx_lock(&ps->ps_mtx); 2217 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2218 if (kern_sig_discard_ign && 2219 (p->p_sysent->sv_flags & SV_SIG_DISCIGN) == 0) { 2220 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2221 2222 mtx_unlock(&ps->ps_mtx); 2223 if (ksi && (ksi->ksi_flags & KSI_INS)) 2224 ksiginfo_tryfree(ksi); 2225 return (ret); 2226 } else { 2227 action = SIG_CATCH; 2228 intrval = 0; 2229 } 2230 } else { 2231 if (SIGISMEMBER(td->td_sigmask, sig)) 2232 action = SIG_HOLD; 2233 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2234 action = SIG_CATCH; 2235 else 2236 action = SIG_DFL; 2237 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2238 intrval = EINTR; 2239 else 2240 intrval = ERESTART; 2241 } 2242 mtx_unlock(&ps->ps_mtx); 2243 2244 if (prop & SIGPROP_CONT) 2245 sigqueue_delete_stopmask_proc(p); 2246 else if (prop & SIGPROP_STOP) { 2247 /* 2248 * If sending a tty stop signal to a member of an orphaned 2249 * process group, discard the signal here if the action 2250 * is default; don't stop the process below if sleeping, 2251 * and don't clear any pending SIGCONT. 2252 */ 2253 if ((prop & SIGPROP_TTYSTOP) != 0 && 2254 (p->p_pgrp->pg_flags & PGRP_ORPHANED) != 0 && 2255 action == SIG_DFL) { 2256 if (ksi && (ksi->ksi_flags & KSI_INS)) 2257 ksiginfo_tryfree(ksi); 2258 return (ret); 2259 } 2260 sigqueue_delete_proc(p, SIGCONT); 2261 if (p->p_flag & P_CONTINUED) { 2262 p->p_flag &= ~P_CONTINUED; 2263 PROC_LOCK(p->p_pptr); 2264 sigqueue_take(p->p_ksi); 2265 PROC_UNLOCK(p->p_pptr); 2266 } 2267 } 2268 2269 ret = sigqueue_add(sigqueue, sig, ksi); 2270 if (ret != 0) 2271 return (ret); 2272 signotify(td); 2273 /* 2274 * Defer further processing for signals which are held, 2275 * except that stopped processes must be continued by SIGCONT. 2276 */ 2277 if (action == SIG_HOLD && 2278 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2279 return (ret); 2280 2281 wakeup_swapper = 0; 2282 2283 /* 2284 * Some signals have a process-wide effect and a per-thread 2285 * component. Most processing occurs when the process next 2286 * tries to cross the user boundary, however there are some 2287 * times when processing needs to be done immediately, such as 2288 * waking up threads so that they can cross the user boundary. 2289 * We try to do the per-process part here. 2290 */ 2291 if (P_SHOULDSTOP(p)) { 2292 KASSERT(!(p->p_flag & P_WEXIT), 2293 ("signal to stopped but exiting process")); 2294 if (sig == SIGKILL) { 2295 /* 2296 * If traced process is already stopped, 2297 * then no further action is necessary. 2298 */ 2299 if (p->p_flag & P_TRACED) 2300 goto out; 2301 /* 2302 * SIGKILL sets process running. 2303 * It will die elsewhere. 2304 * All threads must be restarted. 2305 */ 2306 p->p_flag &= ~P_STOPPED_SIG; 2307 goto runfast; 2308 } 2309 2310 if (prop & SIGPROP_CONT) { 2311 /* 2312 * If traced process is already stopped, 2313 * then no further action is necessary. 2314 */ 2315 if (p->p_flag & P_TRACED) 2316 goto out; 2317 /* 2318 * If SIGCONT is default (or ignored), we continue the 2319 * process but don't leave the signal in sigqueue as 2320 * it has no further action. If SIGCONT is held, we 2321 * continue the process and leave the signal in 2322 * sigqueue. If the process catches SIGCONT, let it 2323 * handle the signal itself. If it isn't waiting on 2324 * an event, it goes back to run state. 2325 * Otherwise, process goes back to sleep state. 2326 */ 2327 p->p_flag &= ~P_STOPPED_SIG; 2328 PROC_SLOCK(p); 2329 if (p->p_numthreads == p->p_suspcount) { 2330 PROC_SUNLOCK(p); 2331 p->p_flag |= P_CONTINUED; 2332 p->p_xsig = SIGCONT; 2333 PROC_LOCK(p->p_pptr); 2334 childproc_continued(p); 2335 PROC_UNLOCK(p->p_pptr); 2336 PROC_SLOCK(p); 2337 } 2338 if (action == SIG_DFL) { 2339 thread_unsuspend(p); 2340 PROC_SUNLOCK(p); 2341 sigqueue_delete(sigqueue, sig); 2342 goto out_cont; 2343 } 2344 if (action == SIG_CATCH) { 2345 /* 2346 * The process wants to catch it so it needs 2347 * to run at least one thread, but which one? 2348 */ 2349 PROC_SUNLOCK(p); 2350 goto runfast; 2351 } 2352 /* 2353 * The signal is not ignored or caught. 2354 */ 2355 thread_unsuspend(p); 2356 PROC_SUNLOCK(p); 2357 goto out_cont; 2358 } 2359 2360 if (prop & SIGPROP_STOP) { 2361 /* 2362 * If traced process is already stopped, 2363 * then no further action is necessary. 2364 */ 2365 if (p->p_flag & P_TRACED) 2366 goto out; 2367 /* 2368 * Already stopped, don't need to stop again 2369 * (If we did the shell could get confused). 2370 * Just make sure the signal STOP bit set. 2371 */ 2372 p->p_flag |= P_STOPPED_SIG; 2373 sigqueue_delete(sigqueue, sig); 2374 goto out; 2375 } 2376 2377 /* 2378 * All other kinds of signals: 2379 * If a thread is sleeping interruptibly, simulate a 2380 * wakeup so that when it is continued it will be made 2381 * runnable and can look at the signal. However, don't make 2382 * the PROCESS runnable, leave it stopped. 2383 * It may run a bit until it hits a thread_suspend_check(). 2384 */ 2385 PROC_SLOCK(p); 2386 thread_lock(td); 2387 if (TD_CAN_ABORT(td)) 2388 wakeup_swapper = sig_sleepq_abort(td, intrval); 2389 else 2390 thread_unlock(td); 2391 PROC_SUNLOCK(p); 2392 goto out; 2393 /* 2394 * Mutexes are short lived. Threads waiting on them will 2395 * hit thread_suspend_check() soon. 2396 */ 2397 } else if (p->p_state == PRS_NORMAL) { 2398 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2399 tdsigwakeup(td, sig, action, intrval); 2400 goto out; 2401 } 2402 2403 MPASS(action == SIG_DFL); 2404 2405 if (prop & SIGPROP_STOP) { 2406 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2407 goto out; 2408 p->p_flag |= P_STOPPED_SIG; 2409 p->p_xsig = sig; 2410 PROC_SLOCK(p); 2411 wakeup_swapper = sig_suspend_threads(td, p, 1); 2412 if (p->p_numthreads == p->p_suspcount) { 2413 /* 2414 * only thread sending signal to another 2415 * process can reach here, if thread is sending 2416 * signal to its process, because thread does 2417 * not suspend itself here, p_numthreads 2418 * should never be equal to p_suspcount. 2419 */ 2420 thread_stopped(p); 2421 PROC_SUNLOCK(p); 2422 sigqueue_delete_proc(p, p->p_xsig); 2423 } else 2424 PROC_SUNLOCK(p); 2425 goto out; 2426 } 2427 } else { 2428 /* Not in "NORMAL" state. discard the signal. */ 2429 sigqueue_delete(sigqueue, sig); 2430 goto out; 2431 } 2432 2433 /* 2434 * The process is not stopped so we need to apply the signal to all the 2435 * running threads. 2436 */ 2437 runfast: 2438 tdsigwakeup(td, sig, action, intrval); 2439 PROC_SLOCK(p); 2440 thread_unsuspend(p); 2441 PROC_SUNLOCK(p); 2442 out_cont: 2443 itimer_proc_continue(p); 2444 kqtimer_proc_continue(p); 2445 out: 2446 /* If we jump here, proc slock should not be owned. */ 2447 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2448 if (wakeup_swapper) 2449 kick_proc0(); 2450 2451 return (ret); 2452 } 2453 2454 /* 2455 * The force of a signal has been directed against a single 2456 * thread. We need to see what we can do about knocking it 2457 * out of any sleep it may be in etc. 2458 */ 2459 static void 2460 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2461 { 2462 struct proc *p = td->td_proc; 2463 int prop, wakeup_swapper; 2464 2465 PROC_LOCK_ASSERT(p, MA_OWNED); 2466 prop = sigprop(sig); 2467 2468 PROC_SLOCK(p); 2469 thread_lock(td); 2470 /* 2471 * Bring the priority of a thread up if we want it to get 2472 * killed in this lifetime. Be careful to avoid bumping the 2473 * priority of the idle thread, since we still allow to signal 2474 * kernel processes. 2475 */ 2476 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2477 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2478 sched_prio(td, PUSER); 2479 if (TD_ON_SLEEPQ(td)) { 2480 /* 2481 * If thread is sleeping uninterruptibly 2482 * we can't interrupt the sleep... the signal will 2483 * be noticed when the process returns through 2484 * trap() or syscall(). 2485 */ 2486 if ((td->td_flags & TDF_SINTR) == 0) 2487 goto out; 2488 /* 2489 * If SIGCONT is default (or ignored) and process is 2490 * asleep, we are finished; the process should not 2491 * be awakened. 2492 */ 2493 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2494 thread_unlock(td); 2495 PROC_SUNLOCK(p); 2496 sigqueue_delete(&p->p_sigqueue, sig); 2497 /* 2498 * It may be on either list in this state. 2499 * Remove from both for now. 2500 */ 2501 sigqueue_delete(&td->td_sigqueue, sig); 2502 return; 2503 } 2504 2505 /* 2506 * Don't awaken a sleeping thread for SIGSTOP if the 2507 * STOP signal is deferred. 2508 */ 2509 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2510 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2511 goto out; 2512 2513 /* 2514 * Give low priority threads a better chance to run. 2515 */ 2516 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2517 sched_prio(td, PUSER); 2518 2519 wakeup_swapper = sig_sleepq_abort(td, intrval); 2520 PROC_SUNLOCK(p); 2521 if (wakeup_swapper) 2522 kick_proc0(); 2523 return; 2524 } 2525 2526 /* 2527 * Other states do nothing with the signal immediately, 2528 * other than kicking ourselves if we are running. 2529 * It will either never be noticed, or noticed very soon. 2530 */ 2531 #ifdef SMP 2532 if (TD_IS_RUNNING(td) && td != curthread) 2533 forward_signal(td); 2534 #endif 2535 2536 out: 2537 PROC_SUNLOCK(p); 2538 thread_unlock(td); 2539 } 2540 2541 static void 2542 ptrace_coredump(struct thread *td) 2543 { 2544 struct proc *p; 2545 struct thr_coredump_req *tcq; 2546 void *rl_cookie; 2547 2548 MPASS(td == curthread); 2549 p = td->td_proc; 2550 PROC_LOCK_ASSERT(p, MA_OWNED); 2551 if ((td->td_dbgflags & TDB_COREDUMPRQ) == 0) 2552 return; 2553 KASSERT((p->p_flag & P_STOPPED_TRACE) != 0, ("not stopped")); 2554 2555 tcq = td->td_coredump; 2556 KASSERT(tcq != NULL, ("td_coredump is NULL")); 2557 2558 if (p->p_sysent->sv_coredump == NULL) { 2559 tcq->tc_error = ENOSYS; 2560 goto wake; 2561 } 2562 2563 PROC_UNLOCK(p); 2564 rl_cookie = vn_rangelock_wlock(tcq->tc_vp, 0, OFF_MAX); 2565 2566 tcq->tc_error = p->p_sysent->sv_coredump(td, tcq->tc_vp, 2567 tcq->tc_limit, tcq->tc_flags); 2568 2569 vn_rangelock_unlock(tcq->tc_vp, rl_cookie); 2570 PROC_LOCK(p); 2571 wake: 2572 td->td_dbgflags &= ~TDB_COREDUMPRQ; 2573 td->td_coredump = NULL; 2574 wakeup(p); 2575 } 2576 2577 static int 2578 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2579 { 2580 struct thread *td2; 2581 int wakeup_swapper; 2582 2583 PROC_LOCK_ASSERT(p, MA_OWNED); 2584 PROC_SLOCK_ASSERT(p, MA_OWNED); 2585 MPASS(sending || td == curthread); 2586 2587 wakeup_swapper = 0; 2588 FOREACH_THREAD_IN_PROC(p, td2) { 2589 thread_lock(td2); 2590 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2591 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2592 (td2->td_flags & TDF_SINTR)) { 2593 if (td2->td_flags & TDF_SBDRY) { 2594 /* 2595 * Once a thread is asleep with 2596 * TDF_SBDRY and without TDF_SERESTART 2597 * or TDF_SEINTR set, it should never 2598 * become suspended due to this check. 2599 */ 2600 KASSERT(!TD_IS_SUSPENDED(td2), 2601 ("thread with deferred stops suspended")); 2602 if (TD_SBDRY_INTR(td2)) { 2603 wakeup_swapper |= sleepq_abort(td2, 2604 TD_SBDRY_ERRNO(td2)); 2605 continue; 2606 } 2607 } else if (!TD_IS_SUSPENDED(td2)) 2608 thread_suspend_one(td2); 2609 } else if (!TD_IS_SUSPENDED(td2)) { 2610 if (sending || td != td2) 2611 td2->td_flags |= TDF_ASTPENDING; 2612 #ifdef SMP 2613 if (TD_IS_RUNNING(td2) && td2 != td) 2614 forward_signal(td2); 2615 #endif 2616 } 2617 thread_unlock(td2); 2618 } 2619 return (wakeup_swapper); 2620 } 2621 2622 /* 2623 * Stop the process for an event deemed interesting to the debugger. If si is 2624 * non-NULL, this is a signal exchange; the new signal requested by the 2625 * debugger will be returned for handling. If si is NULL, this is some other 2626 * type of interesting event. The debugger may request a signal be delivered in 2627 * that case as well, however it will be deferred until it can be handled. 2628 */ 2629 int 2630 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2631 { 2632 struct proc *p = td->td_proc; 2633 struct thread *td2; 2634 ksiginfo_t ksi; 2635 2636 PROC_LOCK_ASSERT(p, MA_OWNED); 2637 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2638 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2639 &p->p_mtx.lock_object, "Stopping for traced signal"); 2640 2641 td->td_xsig = sig; 2642 2643 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2644 td->td_dbgflags |= TDB_XSIG; 2645 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2646 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2647 PROC_SLOCK(p); 2648 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2649 if (P_KILLED(p)) { 2650 /* 2651 * Ensure that, if we've been PT_KILLed, the 2652 * exit status reflects that. Another thread 2653 * may also be in ptracestop(), having just 2654 * received the SIGKILL, but this thread was 2655 * unsuspended first. 2656 */ 2657 td->td_dbgflags &= ~TDB_XSIG; 2658 td->td_xsig = SIGKILL; 2659 p->p_ptevents = 0; 2660 break; 2661 } 2662 if (p->p_flag & P_SINGLE_EXIT && 2663 !(td->td_dbgflags & TDB_EXIT)) { 2664 /* 2665 * Ignore ptrace stops except for thread exit 2666 * events when the process exits. 2667 */ 2668 td->td_dbgflags &= ~TDB_XSIG; 2669 PROC_SUNLOCK(p); 2670 return (0); 2671 } 2672 2673 /* 2674 * Make wait(2) work. Ensure that right after the 2675 * attach, the thread which was decided to become the 2676 * leader of attach gets reported to the waiter. 2677 * Otherwise, just avoid overwriting another thread's 2678 * assignment to p_xthread. If another thread has 2679 * already set p_xthread, the current thread will get 2680 * a chance to report itself upon the next iteration. 2681 */ 2682 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2683 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2684 p->p_xthread == NULL)) { 2685 p->p_xsig = sig; 2686 p->p_xthread = td; 2687 2688 /* 2689 * If we are on sleepqueue already, 2690 * let sleepqueue code decide if it 2691 * needs to go sleep after attach. 2692 */ 2693 if (td->td_wchan == NULL) 2694 td->td_dbgflags &= ~TDB_FSTP; 2695 2696 p->p_flag2 &= ~P2_PTRACE_FSTP; 2697 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2698 sig_suspend_threads(td, p, 0); 2699 } 2700 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2701 td->td_dbgflags &= ~TDB_STOPATFORK; 2702 } 2703 stopme: 2704 td->td_dbgflags |= TDB_SSWITCH; 2705 thread_suspend_switch(td, p); 2706 td->td_dbgflags &= ~TDB_SSWITCH; 2707 if ((td->td_dbgflags & TDB_COREDUMPRQ) != 0) { 2708 PROC_SUNLOCK(p); 2709 ptrace_coredump(td); 2710 PROC_SLOCK(p); 2711 goto stopme; 2712 } 2713 if (p->p_xthread == td) 2714 p->p_xthread = NULL; 2715 if (!(p->p_flag & P_TRACED)) 2716 break; 2717 if (td->td_dbgflags & TDB_SUSPEND) { 2718 if (p->p_flag & P_SINGLE_EXIT) 2719 break; 2720 goto stopme; 2721 } 2722 } 2723 PROC_SUNLOCK(p); 2724 } 2725 2726 if (si != NULL && sig == td->td_xsig) { 2727 /* Parent wants us to take the original signal unchanged. */ 2728 si->ksi_flags |= KSI_HEAD; 2729 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2730 si->ksi_signo = 0; 2731 } else if (td->td_xsig != 0) { 2732 /* 2733 * If parent wants us to take a new signal, then it will leave 2734 * it in td->td_xsig; otherwise we just look for signals again. 2735 */ 2736 ksiginfo_init(&ksi); 2737 ksi.ksi_signo = td->td_xsig; 2738 ksi.ksi_flags |= KSI_PTRACE; 2739 td2 = sigtd(p, td->td_xsig, false); 2740 tdsendsignal(p, td2, td->td_xsig, &ksi); 2741 if (td != td2) 2742 return (0); 2743 } 2744 2745 return (td->td_xsig); 2746 } 2747 2748 static void 2749 reschedule_signals(struct proc *p, sigset_t block, int flags) 2750 { 2751 struct sigacts *ps; 2752 struct thread *td; 2753 int sig; 2754 bool fastblk, pslocked; 2755 2756 PROC_LOCK_ASSERT(p, MA_OWNED); 2757 ps = p->p_sigacts; 2758 pslocked = (flags & SIGPROCMASK_PS_LOCKED) != 0; 2759 mtx_assert(&ps->ps_mtx, pslocked ? MA_OWNED : MA_NOTOWNED); 2760 if (SIGISEMPTY(p->p_siglist)) 2761 return; 2762 SIGSETAND(block, p->p_siglist); 2763 fastblk = (flags & SIGPROCMASK_FASTBLK) != 0; 2764 SIG_FOREACH(sig, &block) { 2765 td = sigtd(p, sig, fastblk); 2766 2767 /* 2768 * If sigtd() selected us despite sigfastblock is 2769 * blocking, do not activate AST or wake us, to avoid 2770 * loop in AST handler. 2771 */ 2772 if (fastblk && td == curthread) 2773 continue; 2774 2775 signotify(td); 2776 if (!pslocked) 2777 mtx_lock(&ps->ps_mtx); 2778 if (p->p_flag & P_TRACED || 2779 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2780 !SIGISMEMBER(td->td_sigmask, sig))) { 2781 tdsigwakeup(td, sig, SIG_CATCH, 2782 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2783 ERESTART)); 2784 } 2785 if (!pslocked) 2786 mtx_unlock(&ps->ps_mtx); 2787 } 2788 } 2789 2790 void 2791 tdsigcleanup(struct thread *td) 2792 { 2793 struct proc *p; 2794 sigset_t unblocked; 2795 2796 p = td->td_proc; 2797 PROC_LOCK_ASSERT(p, MA_OWNED); 2798 2799 sigqueue_flush(&td->td_sigqueue); 2800 if (p->p_numthreads == 1) 2801 return; 2802 2803 /* 2804 * Since we cannot handle signals, notify signal post code 2805 * about this by filling the sigmask. 2806 * 2807 * Also, if needed, wake up thread(s) that do not block the 2808 * same signals as the exiting thread, since the thread might 2809 * have been selected for delivery and woken up. 2810 */ 2811 SIGFILLSET(unblocked); 2812 SIGSETNAND(unblocked, td->td_sigmask); 2813 SIGFILLSET(td->td_sigmask); 2814 reschedule_signals(p, unblocked, 0); 2815 2816 } 2817 2818 static int 2819 sigdeferstop_curr_flags(int cflags) 2820 { 2821 2822 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2823 (cflags & TDF_SBDRY) != 0); 2824 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2825 } 2826 2827 /* 2828 * Defer the delivery of SIGSTOP for the current thread, according to 2829 * the requested mode. Returns previous flags, which must be restored 2830 * by sigallowstop(). 2831 * 2832 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2833 * cleared by the current thread, which allow the lock-less read-only 2834 * accesses below. 2835 */ 2836 int 2837 sigdeferstop_impl(int mode) 2838 { 2839 struct thread *td; 2840 int cflags, nflags; 2841 2842 td = curthread; 2843 cflags = sigdeferstop_curr_flags(td->td_flags); 2844 switch (mode) { 2845 case SIGDEFERSTOP_NOP: 2846 nflags = cflags; 2847 break; 2848 case SIGDEFERSTOP_OFF: 2849 nflags = 0; 2850 break; 2851 case SIGDEFERSTOP_SILENT: 2852 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2853 break; 2854 case SIGDEFERSTOP_EINTR: 2855 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2856 break; 2857 case SIGDEFERSTOP_ERESTART: 2858 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2859 break; 2860 default: 2861 panic("sigdeferstop: invalid mode %x", mode); 2862 break; 2863 } 2864 if (cflags == nflags) 2865 return (SIGDEFERSTOP_VAL_NCHG); 2866 thread_lock(td); 2867 td->td_flags = (td->td_flags & ~cflags) | nflags; 2868 thread_unlock(td); 2869 return (cflags); 2870 } 2871 2872 /* 2873 * Restores the STOP handling mode, typically permitting the delivery 2874 * of SIGSTOP for the current thread. This does not immediately 2875 * suspend if a stop was posted. Instead, the thread will suspend 2876 * either via ast() or a subsequent interruptible sleep. 2877 */ 2878 void 2879 sigallowstop_impl(int prev) 2880 { 2881 struct thread *td; 2882 int cflags; 2883 2884 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2885 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2886 ("sigallowstop: incorrect previous mode %x", prev)); 2887 td = curthread; 2888 cflags = sigdeferstop_curr_flags(td->td_flags); 2889 if (cflags != prev) { 2890 thread_lock(td); 2891 td->td_flags = (td->td_flags & ~cflags) | prev; 2892 thread_unlock(td); 2893 } 2894 } 2895 2896 enum sigstatus { 2897 SIGSTATUS_HANDLE, 2898 SIGSTATUS_HANDLED, 2899 SIGSTATUS_IGNORE, 2900 SIGSTATUS_SBDRY_STOP, 2901 }; 2902 2903 /* 2904 * The thread has signal "sig" pending. Figure out what to do with it: 2905 * 2906 * _HANDLE -> the caller should handle the signal 2907 * _HANDLED -> handled internally, reload pending signal set 2908 * _IGNORE -> ignored, remove from the set of pending signals and try the 2909 * next pending signal 2910 * _SBDRY_STOP -> the signal should stop the thread but this is not 2911 * permitted in the current context 2912 */ 2913 static enum sigstatus 2914 sigprocess(struct thread *td, int sig) 2915 { 2916 struct proc *p; 2917 struct sigacts *ps; 2918 struct sigqueue *queue; 2919 ksiginfo_t ksi; 2920 int prop; 2921 2922 KASSERT(_SIG_VALID(sig), ("%s: invalid signal %d", __func__, sig)); 2923 2924 p = td->td_proc; 2925 ps = p->p_sigacts; 2926 mtx_assert(&ps->ps_mtx, MA_OWNED); 2927 PROC_LOCK_ASSERT(p, MA_OWNED); 2928 2929 /* 2930 * We should allow pending but ignored signals below 2931 * if there is sigwait() active, or P_TRACED was 2932 * on when they were posted. 2933 */ 2934 if (SIGISMEMBER(ps->ps_sigignore, sig) && 2935 (p->p_flag & P_TRACED) == 0 && 2936 (td->td_flags & TDF_SIGWAIT) == 0) { 2937 return (SIGSTATUS_IGNORE); 2938 } 2939 2940 /* 2941 * If the process is going to single-thread mode to prepare 2942 * for exit, there is no sense in delivering any signal 2943 * to usermode. Another important consequence is that 2944 * msleep(..., PCATCH, ...) now is only interruptible by a 2945 * suspend request. 2946 */ 2947 if ((p->p_flag2 & P2_WEXIT) != 0) 2948 return (SIGSTATUS_IGNORE); 2949 2950 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2951 /* 2952 * If traced, always stop. 2953 * Remove old signal from queue before the stop. 2954 * XXX shrug off debugger, it causes siginfo to 2955 * be thrown away. 2956 */ 2957 queue = &td->td_sigqueue; 2958 ksiginfo_init(&ksi); 2959 if (sigqueue_get(queue, sig, &ksi) == 0) { 2960 queue = &p->p_sigqueue; 2961 sigqueue_get(queue, sig, &ksi); 2962 } 2963 td->td_si = ksi.ksi_info; 2964 2965 mtx_unlock(&ps->ps_mtx); 2966 sig = ptracestop(td, sig, &ksi); 2967 mtx_lock(&ps->ps_mtx); 2968 2969 td->td_si.si_signo = 0; 2970 2971 /* 2972 * Keep looking if the debugger discarded or 2973 * replaced the signal. 2974 */ 2975 if (sig == 0) 2976 return (SIGSTATUS_HANDLED); 2977 2978 /* 2979 * If the signal became masked, re-queue it. 2980 */ 2981 if (SIGISMEMBER(td->td_sigmask, sig)) { 2982 ksi.ksi_flags |= KSI_HEAD; 2983 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2984 return (SIGSTATUS_HANDLED); 2985 } 2986 2987 /* 2988 * If the traced bit got turned off, requeue the signal and 2989 * reload the set of pending signals. This ensures that p_sig* 2990 * and p_sigact are consistent. 2991 */ 2992 if ((p->p_flag & P_TRACED) == 0) { 2993 if ((ksi.ksi_flags & KSI_PTRACE) == 0) { 2994 ksi.ksi_flags |= KSI_HEAD; 2995 sigqueue_add(queue, sig, &ksi); 2996 } 2997 return (SIGSTATUS_HANDLED); 2998 } 2999 } 3000 3001 /* 3002 * Decide whether the signal should be returned. 3003 * Return the signal's number, or fall through 3004 * to clear it from the pending mask. 3005 */ 3006 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 3007 case (intptr_t)SIG_DFL: 3008 /* 3009 * Don't take default actions on system processes. 3010 */ 3011 if (p->p_pid <= 1) { 3012 #ifdef DIAGNOSTIC 3013 /* 3014 * Are you sure you want to ignore SIGSEGV 3015 * in init? XXX 3016 */ 3017 printf("Process (pid %lu) got signal %d\n", 3018 (u_long)p->p_pid, sig); 3019 #endif 3020 return (SIGSTATUS_IGNORE); 3021 } 3022 3023 /* 3024 * If there is a pending stop signal to process with 3025 * default action, stop here, then clear the signal. 3026 * Traced or exiting processes should ignore stops. 3027 * Additionally, a member of an orphaned process group 3028 * should ignore tty stops. 3029 */ 3030 prop = sigprop(sig); 3031 if (prop & SIGPROP_STOP) { 3032 mtx_unlock(&ps->ps_mtx); 3033 if ((p->p_flag & (P_TRACED | P_WEXIT | 3034 P_SINGLE_EXIT)) != 0 || ((p->p_pgrp-> 3035 pg_flags & PGRP_ORPHANED) != 0 && 3036 (prop & SIGPROP_TTYSTOP) != 0)) { 3037 mtx_lock(&ps->ps_mtx); 3038 return (SIGSTATUS_IGNORE); 3039 } 3040 if (TD_SBDRY_INTR(td)) { 3041 KASSERT((td->td_flags & TDF_SBDRY) != 0, 3042 ("lost TDF_SBDRY")); 3043 mtx_lock(&ps->ps_mtx); 3044 return (SIGSTATUS_SBDRY_STOP); 3045 } 3046 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 3047 &p->p_mtx.lock_object, "Catching SIGSTOP"); 3048 sigqueue_delete(&td->td_sigqueue, sig); 3049 sigqueue_delete(&p->p_sigqueue, sig); 3050 p->p_flag |= P_STOPPED_SIG; 3051 p->p_xsig = sig; 3052 PROC_SLOCK(p); 3053 sig_suspend_threads(td, p, 0); 3054 thread_suspend_switch(td, p); 3055 PROC_SUNLOCK(p); 3056 mtx_lock(&ps->ps_mtx); 3057 return (SIGSTATUS_HANDLED); 3058 } else if ((prop & SIGPROP_IGNORE) != 0 && 3059 (td->td_flags & TDF_SIGWAIT) == 0) { 3060 /* 3061 * Default action is to ignore; drop it if 3062 * not in kern_sigtimedwait(). 3063 */ 3064 return (SIGSTATUS_IGNORE); 3065 } else { 3066 return (SIGSTATUS_HANDLE); 3067 } 3068 3069 case (intptr_t)SIG_IGN: 3070 if ((td->td_flags & TDF_SIGWAIT) == 0) 3071 return (SIGSTATUS_IGNORE); 3072 else 3073 return (SIGSTATUS_HANDLE); 3074 3075 default: 3076 /* 3077 * This signal has an action, let postsig() process it. 3078 */ 3079 return (SIGSTATUS_HANDLE); 3080 } 3081 } 3082 3083 /* 3084 * If the current process has received a signal (should be caught or cause 3085 * termination, should interrupt current syscall), return the signal number. 3086 * Stop signals with default action are processed immediately, then cleared; 3087 * they aren't returned. This is checked after each entry to the system for 3088 * a syscall or trap (though this can usually be done without calling 3089 * issignal by checking the pending signal masks in cursig.) The normal call 3090 * sequence is 3091 * 3092 * while (sig = cursig(curthread)) 3093 * postsig(sig); 3094 */ 3095 static int 3096 issignal(struct thread *td) 3097 { 3098 struct proc *p; 3099 sigset_t sigpending; 3100 int sig; 3101 3102 p = td->td_proc; 3103 PROC_LOCK_ASSERT(p, MA_OWNED); 3104 3105 for (;;) { 3106 sigpending = td->td_sigqueue.sq_signals; 3107 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 3108 SIGSETNAND(sigpending, td->td_sigmask); 3109 3110 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 3111 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 3112 SIG_STOPSIGMASK(sigpending); 3113 if (SIGISEMPTY(sigpending)) /* no signal to send */ 3114 return (0); 3115 3116 /* 3117 * Do fast sigblock if requested by usermode. Since 3118 * we do know that there was a signal pending at this 3119 * point, set the FAST_SIGBLOCK_PEND as indicator for 3120 * usermode to perform a dummy call to 3121 * FAST_SIGBLOCK_UNBLOCK, which causes immediate 3122 * delivery of postponed pending signal. 3123 */ 3124 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 3125 if (td->td_sigblock_val != 0) 3126 SIGSETNAND(sigpending, fastblock_mask); 3127 if (SIGISEMPTY(sigpending)) { 3128 td->td_pflags |= TDP_SIGFASTPENDING; 3129 return (0); 3130 } 3131 } 3132 3133 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 3134 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 3135 SIGISMEMBER(sigpending, SIGSTOP)) { 3136 /* 3137 * If debugger just attached, always consume 3138 * SIGSTOP from ptrace(PT_ATTACH) first, to 3139 * execute the debugger attach ritual in 3140 * order. 3141 */ 3142 td->td_dbgflags |= TDB_FSTP; 3143 SIGEMPTYSET(sigpending); 3144 SIGADDSET(sigpending, SIGSTOP); 3145 } 3146 3147 SIG_FOREACH(sig, &sigpending) { 3148 switch (sigprocess(td, sig)) { 3149 case SIGSTATUS_HANDLE: 3150 return (sig); 3151 case SIGSTATUS_HANDLED: 3152 goto next; 3153 case SIGSTATUS_IGNORE: 3154 sigqueue_delete(&td->td_sigqueue, sig); 3155 sigqueue_delete(&p->p_sigqueue, sig); 3156 break; 3157 case SIGSTATUS_SBDRY_STOP: 3158 return (-1); 3159 } 3160 } 3161 next:; 3162 } 3163 } 3164 3165 void 3166 thread_stopped(struct proc *p) 3167 { 3168 int n; 3169 3170 PROC_LOCK_ASSERT(p, MA_OWNED); 3171 PROC_SLOCK_ASSERT(p, MA_OWNED); 3172 n = p->p_suspcount; 3173 if (p == curproc) 3174 n++; 3175 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 3176 PROC_SUNLOCK(p); 3177 p->p_flag &= ~P_WAITED; 3178 PROC_LOCK(p->p_pptr); 3179 childproc_stopped(p, (p->p_flag & P_TRACED) ? 3180 CLD_TRAPPED : CLD_STOPPED); 3181 PROC_UNLOCK(p->p_pptr); 3182 PROC_SLOCK(p); 3183 } 3184 } 3185 3186 /* 3187 * Take the action for the specified signal 3188 * from the current set of pending signals. 3189 */ 3190 int 3191 postsig(int sig) 3192 { 3193 struct thread *td; 3194 struct proc *p; 3195 struct sigacts *ps; 3196 sig_t action; 3197 ksiginfo_t ksi; 3198 sigset_t returnmask; 3199 3200 KASSERT(sig != 0, ("postsig")); 3201 3202 td = curthread; 3203 p = td->td_proc; 3204 PROC_LOCK_ASSERT(p, MA_OWNED); 3205 ps = p->p_sigacts; 3206 mtx_assert(&ps->ps_mtx, MA_OWNED); 3207 ksiginfo_init(&ksi); 3208 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3209 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3210 return (0); 3211 ksi.ksi_signo = sig; 3212 if (ksi.ksi_code == SI_TIMER) 3213 itimer_accept(p, ksi.ksi_timerid, &ksi); 3214 action = ps->ps_sigact[_SIG_IDX(sig)]; 3215 #ifdef KTRACE 3216 if (KTRPOINT(td, KTR_PSIG)) 3217 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3218 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3219 #endif 3220 3221 if (action == SIG_DFL) { 3222 /* 3223 * Default action, where the default is to kill 3224 * the process. (Other cases were ignored above.) 3225 */ 3226 mtx_unlock(&ps->ps_mtx); 3227 proc_td_siginfo_capture(td, &ksi.ksi_info); 3228 sigexit(td, sig); 3229 /* NOTREACHED */ 3230 } else { 3231 /* 3232 * If we get here, the signal must be caught. 3233 */ 3234 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3235 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3236 ("postsig action: blocked sig %d", sig)); 3237 3238 /* 3239 * Set the new mask value and also defer further 3240 * occurrences of this signal. 3241 * 3242 * Special case: user has done a sigsuspend. Here the 3243 * current mask is not of interest, but rather the 3244 * mask from before the sigsuspend is what we want 3245 * restored after the signal processing is completed. 3246 */ 3247 if (td->td_pflags & TDP_OLDMASK) { 3248 returnmask = td->td_oldsigmask; 3249 td->td_pflags &= ~TDP_OLDMASK; 3250 } else 3251 returnmask = td->td_sigmask; 3252 3253 if (p->p_sig == sig) { 3254 p->p_sig = 0; 3255 } 3256 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3257 postsig_done(sig, td, ps); 3258 } 3259 return (1); 3260 } 3261 3262 int 3263 sig_ast_checksusp(struct thread *td) 3264 { 3265 struct proc *p __diagused; 3266 int ret; 3267 3268 p = td->td_proc; 3269 PROC_LOCK_ASSERT(p, MA_OWNED); 3270 3271 if ((td->td_flags & TDF_NEEDSUSPCHK) == 0) 3272 return (0); 3273 3274 ret = thread_suspend_check(1); 3275 MPASS(ret == 0 || ret == EINTR || ret == ERESTART); 3276 return (ret); 3277 } 3278 3279 int 3280 sig_ast_needsigchk(struct thread *td) 3281 { 3282 struct proc *p; 3283 struct sigacts *ps; 3284 int ret, sig; 3285 3286 p = td->td_proc; 3287 PROC_LOCK_ASSERT(p, MA_OWNED); 3288 3289 if ((td->td_flags & TDF_NEEDSIGCHK) == 0) 3290 return (0); 3291 3292 ps = p->p_sigacts; 3293 mtx_lock(&ps->ps_mtx); 3294 sig = cursig(td); 3295 if (sig == -1) { 3296 mtx_unlock(&ps->ps_mtx); 3297 KASSERT((td->td_flags & TDF_SBDRY) != 0, ("lost TDF_SBDRY")); 3298 KASSERT(TD_SBDRY_INTR(td), 3299 ("lost TDF_SERESTART of TDF_SEINTR")); 3300 KASSERT((td->td_flags & (TDF_SEINTR | TDF_SERESTART)) != 3301 (TDF_SEINTR | TDF_SERESTART), 3302 ("both TDF_SEINTR and TDF_SERESTART")); 3303 ret = TD_SBDRY_ERRNO(td); 3304 } else if (sig != 0) { 3305 ret = SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : ERESTART; 3306 mtx_unlock(&ps->ps_mtx); 3307 } else { 3308 mtx_unlock(&ps->ps_mtx); 3309 ret = 0; 3310 } 3311 3312 /* 3313 * Do not go into sleep if this thread was the ptrace(2) 3314 * attach leader. cursig() consumed SIGSTOP from PT_ATTACH, 3315 * but we usually act on the signal by interrupting sleep, and 3316 * should do that here as well. 3317 */ 3318 if ((td->td_dbgflags & TDB_FSTP) != 0) { 3319 if (ret == 0) 3320 ret = EINTR; 3321 td->td_dbgflags &= ~TDB_FSTP; 3322 } 3323 3324 return (ret); 3325 } 3326 3327 int 3328 sig_intr(void) 3329 { 3330 struct thread *td; 3331 struct proc *p; 3332 int ret; 3333 3334 td = curthread; 3335 if ((td->td_flags & (TDF_NEEDSIGCHK | TDF_NEEDSUSPCHK)) == 0) 3336 return (0); 3337 3338 p = td->td_proc; 3339 3340 PROC_LOCK(p); 3341 ret = sig_ast_checksusp(td); 3342 if (ret == 0) 3343 ret = sig_ast_needsigchk(td); 3344 PROC_UNLOCK(p); 3345 return (ret); 3346 } 3347 3348 bool 3349 curproc_sigkilled(void) 3350 { 3351 struct thread *td; 3352 struct proc *p; 3353 struct sigacts *ps; 3354 bool res; 3355 3356 td = curthread; 3357 if ((td->td_flags & TDF_NEEDSIGCHK) == 0) 3358 return (false); 3359 3360 p = td->td_proc; 3361 PROC_LOCK(p); 3362 ps = p->p_sigacts; 3363 mtx_lock(&ps->ps_mtx); 3364 res = SIGISMEMBER(td->td_sigqueue.sq_signals, SIGKILL) || 3365 SIGISMEMBER(p->p_sigqueue.sq_signals, SIGKILL); 3366 mtx_unlock(&ps->ps_mtx); 3367 PROC_UNLOCK(p); 3368 return (res); 3369 } 3370 3371 void 3372 proc_wkilled(struct proc *p) 3373 { 3374 3375 PROC_LOCK_ASSERT(p, MA_OWNED); 3376 if ((p->p_flag & P_WKILLED) == 0) { 3377 p->p_flag |= P_WKILLED; 3378 /* 3379 * Notify swapper that there is a process to swap in. 3380 * The notification is racy, at worst it would take 10 3381 * seconds for the swapper process to notice. 3382 */ 3383 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3384 wakeup(&proc0); 3385 } 3386 } 3387 3388 /* 3389 * Kill the current process for stated reason. 3390 */ 3391 void 3392 killproc(struct proc *p, const char *why) 3393 { 3394 3395 PROC_LOCK_ASSERT(p, MA_OWNED); 3396 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3397 p->p_comm); 3398 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3399 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3400 p->p_ucred->cr_uid, why); 3401 proc_wkilled(p); 3402 kern_psignal(p, SIGKILL); 3403 } 3404 3405 /* 3406 * Force the current process to exit with the specified signal, dumping core 3407 * if appropriate. We bypass the normal tests for masked and caught signals, 3408 * allowing unrecoverable failures to terminate the process without changing 3409 * signal state. Mark the accounting record with the signal termination. 3410 * If dumping core, save the signal number for the debugger. Calls exit and 3411 * does not return. 3412 */ 3413 void 3414 sigexit(struct thread *td, int sig) 3415 { 3416 struct proc *p = td->td_proc; 3417 3418 PROC_LOCK_ASSERT(p, MA_OWNED); 3419 proc_set_p2_wexit(p); 3420 3421 p->p_acflag |= AXSIG; 3422 /* 3423 * We must be single-threading to generate a core dump. This 3424 * ensures that the registers in the core file are up-to-date. 3425 * Also, the ELF dump handler assumes that the thread list doesn't 3426 * change out from under it. 3427 * 3428 * XXX If another thread attempts to single-thread before us 3429 * (e.g. via fork()), we won't get a dump at all. 3430 */ 3431 if ((sigprop(sig) & SIGPROP_CORE) && 3432 thread_single(p, SINGLE_NO_EXIT) == 0) { 3433 p->p_sig = sig; 3434 /* 3435 * Log signals which would cause core dumps 3436 * (Log as LOG_INFO to appease those who don't want 3437 * these messages.) 3438 * XXX : Todo, as well as euid, write out ruid too 3439 * Note that coredump() drops proc lock. 3440 */ 3441 if (coredump(td) == 0) 3442 sig |= WCOREFLAG; 3443 if (kern_logsigexit) 3444 log(LOG_INFO, 3445 "pid %d (%s), jid %d, uid %d: exited on " 3446 "signal %d%s\n", p->p_pid, p->p_comm, 3447 p->p_ucred->cr_prison->pr_id, 3448 td->td_ucred->cr_uid, 3449 sig &~ WCOREFLAG, 3450 sig & WCOREFLAG ? " (core dumped)" : ""); 3451 } else 3452 PROC_UNLOCK(p); 3453 exit1(td, 0, sig); 3454 /* NOTREACHED */ 3455 } 3456 3457 /* 3458 * Send queued SIGCHLD to parent when child process's state 3459 * is changed. 3460 */ 3461 static void 3462 sigparent(struct proc *p, int reason, int status) 3463 { 3464 PROC_LOCK_ASSERT(p, MA_OWNED); 3465 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3466 3467 if (p->p_ksi != NULL) { 3468 p->p_ksi->ksi_signo = SIGCHLD; 3469 p->p_ksi->ksi_code = reason; 3470 p->p_ksi->ksi_status = status; 3471 p->p_ksi->ksi_pid = p->p_pid; 3472 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3473 if (KSI_ONQ(p->p_ksi)) 3474 return; 3475 } 3476 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3477 } 3478 3479 static void 3480 childproc_jobstate(struct proc *p, int reason, int sig) 3481 { 3482 struct sigacts *ps; 3483 3484 PROC_LOCK_ASSERT(p, MA_OWNED); 3485 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3486 3487 /* 3488 * Wake up parent sleeping in kern_wait(), also send 3489 * SIGCHLD to parent, but SIGCHLD does not guarantee 3490 * that parent will awake, because parent may masked 3491 * the signal. 3492 */ 3493 p->p_pptr->p_flag |= P_STATCHILD; 3494 wakeup(p->p_pptr); 3495 3496 ps = p->p_pptr->p_sigacts; 3497 mtx_lock(&ps->ps_mtx); 3498 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3499 mtx_unlock(&ps->ps_mtx); 3500 sigparent(p, reason, sig); 3501 } else 3502 mtx_unlock(&ps->ps_mtx); 3503 } 3504 3505 void 3506 childproc_stopped(struct proc *p, int reason) 3507 { 3508 3509 childproc_jobstate(p, reason, p->p_xsig); 3510 } 3511 3512 void 3513 childproc_continued(struct proc *p) 3514 { 3515 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3516 } 3517 3518 void 3519 childproc_exited(struct proc *p) 3520 { 3521 int reason, status; 3522 3523 if (WCOREDUMP(p->p_xsig)) { 3524 reason = CLD_DUMPED; 3525 status = WTERMSIG(p->p_xsig); 3526 } else if (WIFSIGNALED(p->p_xsig)) { 3527 reason = CLD_KILLED; 3528 status = WTERMSIG(p->p_xsig); 3529 } else { 3530 reason = CLD_EXITED; 3531 status = p->p_xexit; 3532 } 3533 /* 3534 * XXX avoid calling wakeup(p->p_pptr), the work is 3535 * done in exit1(). 3536 */ 3537 sigparent(p, reason, status); 3538 } 3539 3540 #define MAX_NUM_CORE_FILES 100000 3541 #ifndef NUM_CORE_FILES 3542 #define NUM_CORE_FILES 5 3543 #endif 3544 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3545 static int num_cores = NUM_CORE_FILES; 3546 3547 static int 3548 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3549 { 3550 int error; 3551 int new_val; 3552 3553 new_val = num_cores; 3554 error = sysctl_handle_int(oidp, &new_val, 0, req); 3555 if (error != 0 || req->newptr == NULL) 3556 return (error); 3557 if (new_val > MAX_NUM_CORE_FILES) 3558 new_val = MAX_NUM_CORE_FILES; 3559 if (new_val < 0) 3560 new_val = 0; 3561 num_cores = new_val; 3562 return (0); 3563 } 3564 SYSCTL_PROC(_debug, OID_AUTO, ncores, 3565 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, sizeof(int), 3566 sysctl_debug_num_cores_check, "I", 3567 "Maximum number of generated process corefiles while using index format"); 3568 3569 #define GZIP_SUFFIX ".gz" 3570 #define ZSTD_SUFFIX ".zst" 3571 3572 int compress_user_cores = 0; 3573 3574 static int 3575 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3576 { 3577 int error, val; 3578 3579 val = compress_user_cores; 3580 error = sysctl_handle_int(oidp, &val, 0, req); 3581 if (error != 0 || req->newptr == NULL) 3582 return (error); 3583 if (val != 0 && !compressor_avail(val)) 3584 return (EINVAL); 3585 compress_user_cores = val; 3586 return (error); 3587 } 3588 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, 3589 CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3590 sysctl_compress_user_cores, "I", 3591 "Enable compression of user corefiles (" 3592 __XSTRING(COMPRESS_GZIP) " = gzip, " 3593 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3594 3595 int compress_user_cores_level = 6; 3596 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3597 &compress_user_cores_level, 0, 3598 "Corefile compression level"); 3599 3600 /* 3601 * Protect the access to corefilename[] by allproc_lock. 3602 */ 3603 #define corefilename_lock allproc_lock 3604 3605 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3606 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3607 3608 static int 3609 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3610 { 3611 int error; 3612 3613 sx_xlock(&corefilename_lock); 3614 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3615 req); 3616 sx_xunlock(&corefilename_lock); 3617 3618 return (error); 3619 } 3620 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3621 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3622 "Process corefile name format string"); 3623 3624 static void 3625 vnode_close_locked(struct thread *td, struct vnode *vp) 3626 { 3627 3628 VOP_UNLOCK(vp); 3629 vn_close(vp, FWRITE, td->td_ucred, td); 3630 } 3631 3632 /* 3633 * If the core format has a %I in it, then we need to check 3634 * for existing corefiles before defining a name. 3635 * To do this we iterate over 0..ncores to find a 3636 * non-existing core file name to use. If all core files are 3637 * already used we choose the oldest one. 3638 */ 3639 static int 3640 corefile_open_last(struct thread *td, char *name, int indexpos, 3641 int indexlen, int ncores, struct vnode **vpp) 3642 { 3643 struct vnode *oldvp, *nextvp, *vp; 3644 struct vattr vattr; 3645 struct nameidata nd; 3646 int error, i, flags, oflags, cmode; 3647 char ch; 3648 struct timespec lasttime; 3649 3650 nextvp = oldvp = NULL; 3651 cmode = S_IRUSR | S_IWUSR; 3652 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3653 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3654 3655 for (i = 0; i < ncores; i++) { 3656 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3657 3658 ch = name[indexpos + indexlen]; 3659 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3660 i); 3661 name[indexpos + indexlen] = ch; 3662 3663 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name); 3664 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3665 NULL); 3666 if (error != 0) 3667 break; 3668 3669 vp = nd.ni_vp; 3670 NDFREE_PNBUF(&nd); 3671 if ((flags & O_CREAT) == O_CREAT) { 3672 nextvp = vp; 3673 break; 3674 } 3675 3676 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3677 if (error != 0) { 3678 vnode_close_locked(td, vp); 3679 break; 3680 } 3681 3682 if (oldvp == NULL || 3683 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3684 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3685 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3686 if (oldvp != NULL) 3687 vn_close(oldvp, FWRITE, td->td_ucred, td); 3688 oldvp = vp; 3689 VOP_UNLOCK(oldvp); 3690 lasttime = vattr.va_mtime; 3691 } else { 3692 vnode_close_locked(td, vp); 3693 } 3694 } 3695 3696 if (oldvp != NULL) { 3697 if (nextvp == NULL) { 3698 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3699 error = EFAULT; 3700 vn_close(oldvp, FWRITE, td->td_ucred, td); 3701 } else { 3702 nextvp = oldvp; 3703 error = vn_lock(nextvp, LK_EXCLUSIVE); 3704 if (error != 0) { 3705 vn_close(nextvp, FWRITE, td->td_ucred, 3706 td); 3707 nextvp = NULL; 3708 } 3709 } 3710 } else { 3711 vn_close(oldvp, FWRITE, td->td_ucred, td); 3712 } 3713 } 3714 if (error != 0) { 3715 if (nextvp != NULL) 3716 vnode_close_locked(td, oldvp); 3717 } else { 3718 *vpp = nextvp; 3719 } 3720 3721 return (error); 3722 } 3723 3724 /* 3725 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3726 * Expand the name described in corefilename, using name, uid, and pid 3727 * and open/create core file. 3728 * corefilename is a printf-like string, with three format specifiers: 3729 * %N name of process ("name") 3730 * %P process id (pid) 3731 * %U user id (uid) 3732 * For example, "%N.core" is the default; they can be disabled completely 3733 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3734 * This is controlled by the sysctl variable kern.corefile (see above). 3735 */ 3736 static int 3737 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3738 int compress, int signum, struct vnode **vpp, char **namep) 3739 { 3740 struct sbuf sb; 3741 struct nameidata nd; 3742 const char *format; 3743 char *hostname, *name; 3744 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3745 3746 hostname = NULL; 3747 format = corefilename; 3748 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3749 indexlen = 0; 3750 indexpos = -1; 3751 ncores = num_cores; 3752 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3753 sx_slock(&corefilename_lock); 3754 for (i = 0; format[i] != '\0'; i++) { 3755 switch (format[i]) { 3756 case '%': /* Format character */ 3757 i++; 3758 switch (format[i]) { 3759 case '%': 3760 sbuf_putc(&sb, '%'); 3761 break; 3762 case 'H': /* hostname */ 3763 if (hostname == NULL) { 3764 hostname = malloc(MAXHOSTNAMELEN, 3765 M_TEMP, M_WAITOK); 3766 } 3767 getcredhostname(td->td_ucred, hostname, 3768 MAXHOSTNAMELEN); 3769 sbuf_printf(&sb, "%s", hostname); 3770 break; 3771 case 'I': /* autoincrementing index */ 3772 if (indexpos != -1) { 3773 sbuf_printf(&sb, "%%I"); 3774 break; 3775 } 3776 3777 indexpos = sbuf_len(&sb); 3778 sbuf_printf(&sb, "%u", ncores - 1); 3779 indexlen = sbuf_len(&sb) - indexpos; 3780 break; 3781 case 'N': /* process name */ 3782 sbuf_printf(&sb, "%s", comm); 3783 break; 3784 case 'P': /* process id */ 3785 sbuf_printf(&sb, "%u", pid); 3786 break; 3787 case 'S': /* signal number */ 3788 sbuf_printf(&sb, "%i", signum); 3789 break; 3790 case 'U': /* user id */ 3791 sbuf_printf(&sb, "%u", uid); 3792 break; 3793 default: 3794 log(LOG_ERR, 3795 "Unknown format character %c in " 3796 "corename `%s'\n", format[i], format); 3797 break; 3798 } 3799 break; 3800 default: 3801 sbuf_putc(&sb, format[i]); 3802 break; 3803 } 3804 } 3805 sx_sunlock(&corefilename_lock); 3806 free(hostname, M_TEMP); 3807 if (compress == COMPRESS_GZIP) 3808 sbuf_printf(&sb, GZIP_SUFFIX); 3809 else if (compress == COMPRESS_ZSTD) 3810 sbuf_printf(&sb, ZSTD_SUFFIX); 3811 if (sbuf_error(&sb) != 0) { 3812 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3813 "long\n", (long)pid, comm, (u_long)uid); 3814 sbuf_delete(&sb); 3815 free(name, M_TEMP); 3816 return (ENOMEM); 3817 } 3818 sbuf_finish(&sb); 3819 sbuf_delete(&sb); 3820 3821 if (indexpos != -1) { 3822 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3823 vpp); 3824 if (error != 0) { 3825 log(LOG_ERR, 3826 "pid %d (%s), uid (%u): Path `%s' failed " 3827 "on initial open test, error = %d\n", 3828 pid, comm, uid, name, error); 3829 } 3830 } else { 3831 cmode = S_IRUSR | S_IWUSR; 3832 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3833 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3834 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3835 if ((td->td_proc->p_flag & P_SUGID) != 0) 3836 flags |= O_EXCL; 3837 3838 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name); 3839 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3840 NULL); 3841 if (error == 0) { 3842 *vpp = nd.ni_vp; 3843 NDFREE_PNBUF(&nd); 3844 } 3845 } 3846 3847 if (error != 0) { 3848 #ifdef AUDIT 3849 audit_proc_coredump(td, name, error); 3850 #endif 3851 free(name, M_TEMP); 3852 return (error); 3853 } 3854 *namep = name; 3855 return (0); 3856 } 3857 3858 /* 3859 * Dump a process' core. The main routine does some 3860 * policy checking, and creates the name of the coredump; 3861 * then it passes on a vnode and a size limit to the process-specific 3862 * coredump routine if there is one; if there _is not_ one, it returns 3863 * ENOSYS; otherwise it returns the error from the process-specific routine. 3864 */ 3865 3866 static int 3867 coredump(struct thread *td) 3868 { 3869 struct proc *p = td->td_proc; 3870 struct ucred *cred = td->td_ucred; 3871 struct vnode *vp; 3872 struct flock lf; 3873 struct vattr vattr; 3874 size_t fullpathsize; 3875 int error, error1, locked; 3876 char *name; /* name of corefile */ 3877 void *rl_cookie; 3878 off_t limit; 3879 char *fullpath, *freepath = NULL; 3880 struct sbuf *sb; 3881 3882 PROC_LOCK_ASSERT(p, MA_OWNED); 3883 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3884 3885 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3886 (p->p_flag2 & P2_NOTRACE) != 0) { 3887 PROC_UNLOCK(p); 3888 return (EFAULT); 3889 } 3890 3891 /* 3892 * Note that the bulk of limit checking is done after 3893 * the corefile is created. The exception is if the limit 3894 * for corefiles is 0, in which case we don't bother 3895 * creating the corefile at all. This layout means that 3896 * a corefile is truncated instead of not being created, 3897 * if it is larger than the limit. 3898 */ 3899 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3900 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3901 PROC_UNLOCK(p); 3902 return (EFBIG); 3903 } 3904 PROC_UNLOCK(p); 3905 3906 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3907 compress_user_cores, p->p_sig, &vp, &name); 3908 if (error != 0) 3909 return (error); 3910 3911 /* 3912 * Don't dump to non-regular files or files with links. 3913 * Do not dump into system files. Effective user must own the corefile. 3914 */ 3915 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3916 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 3917 vattr.va_uid != cred->cr_uid) { 3918 VOP_UNLOCK(vp); 3919 error = EFAULT; 3920 goto out; 3921 } 3922 3923 VOP_UNLOCK(vp); 3924 3925 /* Postpone other writers, including core dumps of other processes. */ 3926 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3927 3928 lf.l_whence = SEEK_SET; 3929 lf.l_start = 0; 3930 lf.l_len = 0; 3931 lf.l_type = F_WRLCK; 3932 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3933 3934 VATTR_NULL(&vattr); 3935 vattr.va_size = 0; 3936 if (set_core_nodump_flag) 3937 vattr.va_flags = UF_NODUMP; 3938 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3939 VOP_SETATTR(vp, &vattr, cred); 3940 VOP_UNLOCK(vp); 3941 PROC_LOCK(p); 3942 p->p_acflag |= ACORE; 3943 PROC_UNLOCK(p); 3944 3945 if (p->p_sysent->sv_coredump != NULL) { 3946 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3947 } else { 3948 error = ENOSYS; 3949 } 3950 3951 if (locked) { 3952 lf.l_type = F_UNLCK; 3953 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3954 } 3955 vn_rangelock_unlock(vp, rl_cookie); 3956 3957 /* 3958 * Notify the userland helper that a process triggered a core dump. 3959 * This allows the helper to run an automated debugging session. 3960 */ 3961 if (error != 0 || coredump_devctl == 0) 3962 goto out; 3963 sb = sbuf_new_auto(); 3964 if (vn_fullpath_global(p->p_textvp, &fullpath, &freepath) != 0) 3965 goto out2; 3966 sbuf_printf(sb, "comm=\""); 3967 devctl_safe_quote_sb(sb, fullpath); 3968 free(freepath, M_TEMP); 3969 sbuf_printf(sb, "\" core=\""); 3970 3971 /* 3972 * We can't lookup core file vp directly. When we're replacing a core, and 3973 * other random times, we flush the name cache, so it will fail. Instead, 3974 * if the path of the core is relative, add the current dir in front if it. 3975 */ 3976 if (name[0] != '/') { 3977 fullpathsize = MAXPATHLEN; 3978 freepath = malloc(fullpathsize, M_TEMP, M_WAITOK); 3979 if (vn_getcwd(freepath, &fullpath, &fullpathsize) != 0) { 3980 free(freepath, M_TEMP); 3981 goto out2; 3982 } 3983 devctl_safe_quote_sb(sb, fullpath); 3984 free(freepath, M_TEMP); 3985 sbuf_putc(sb, '/'); 3986 } 3987 devctl_safe_quote_sb(sb, name); 3988 sbuf_printf(sb, "\""); 3989 if (sbuf_finish(sb) == 0) 3990 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 3991 out2: 3992 sbuf_delete(sb); 3993 out: 3994 error1 = vn_close(vp, FWRITE, cred, td); 3995 if (error == 0) 3996 error = error1; 3997 #ifdef AUDIT 3998 audit_proc_coredump(td, name, error); 3999 #endif 4000 free(name, M_TEMP); 4001 return (error); 4002 } 4003 4004 /* 4005 * Nonexistent system call-- signal process (may want to handle it). Flag 4006 * error in case process won't see signal immediately (blocked or ignored). 4007 */ 4008 #ifndef _SYS_SYSPROTO_H_ 4009 struct nosys_args { 4010 int dummy; 4011 }; 4012 #endif 4013 /* ARGSUSED */ 4014 int 4015 nosys(struct thread *td, struct nosys_args *args) 4016 { 4017 struct proc *p; 4018 4019 p = td->td_proc; 4020 4021 PROC_LOCK(p); 4022 tdsignal(td, SIGSYS); 4023 PROC_UNLOCK(p); 4024 if (kern_lognosys == 1 || kern_lognosys == 3) { 4025 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 4026 td->td_sa.code); 4027 } 4028 if (kern_lognosys == 2 || kern_lognosys == 3 || 4029 (p->p_pid == 1 && (kern_lognosys & 3) == 0)) { 4030 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 4031 td->td_sa.code); 4032 } 4033 return (ENOSYS); 4034 } 4035 4036 /* 4037 * Send a SIGIO or SIGURG signal to a process or process group using stored 4038 * credentials rather than those of the current process. 4039 */ 4040 void 4041 pgsigio(struct sigio **sigiop, int sig, int checkctty) 4042 { 4043 ksiginfo_t ksi; 4044 struct sigio *sigio; 4045 4046 ksiginfo_init(&ksi); 4047 ksi.ksi_signo = sig; 4048 ksi.ksi_code = SI_KERNEL; 4049 4050 SIGIO_LOCK(); 4051 sigio = *sigiop; 4052 if (sigio == NULL) { 4053 SIGIO_UNLOCK(); 4054 return; 4055 } 4056 if (sigio->sio_pgid > 0) { 4057 PROC_LOCK(sigio->sio_proc); 4058 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 4059 kern_psignal(sigio->sio_proc, sig); 4060 PROC_UNLOCK(sigio->sio_proc); 4061 } else if (sigio->sio_pgid < 0) { 4062 struct proc *p; 4063 4064 PGRP_LOCK(sigio->sio_pgrp); 4065 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 4066 PROC_LOCK(p); 4067 if (p->p_state == PRS_NORMAL && 4068 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 4069 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 4070 kern_psignal(p, sig); 4071 PROC_UNLOCK(p); 4072 } 4073 PGRP_UNLOCK(sigio->sio_pgrp); 4074 } 4075 SIGIO_UNLOCK(); 4076 } 4077 4078 static int 4079 filt_sigattach(struct knote *kn) 4080 { 4081 struct proc *p = curproc; 4082 4083 kn->kn_ptr.p_proc = p; 4084 kn->kn_flags |= EV_CLEAR; /* automatically set */ 4085 4086 knlist_add(p->p_klist, kn, 0); 4087 4088 return (0); 4089 } 4090 4091 static void 4092 filt_sigdetach(struct knote *kn) 4093 { 4094 struct proc *p = kn->kn_ptr.p_proc; 4095 4096 knlist_remove(p->p_klist, kn, 0); 4097 } 4098 4099 /* 4100 * signal knotes are shared with proc knotes, so we apply a mask to 4101 * the hint in order to differentiate them from process hints. This 4102 * could be avoided by using a signal-specific knote list, but probably 4103 * isn't worth the trouble. 4104 */ 4105 static int 4106 filt_signal(struct knote *kn, long hint) 4107 { 4108 4109 if (hint & NOTE_SIGNAL) { 4110 hint &= ~NOTE_SIGNAL; 4111 4112 if (kn->kn_id == hint) 4113 kn->kn_data++; 4114 } 4115 return (kn->kn_data != 0); 4116 } 4117 4118 struct sigacts * 4119 sigacts_alloc(void) 4120 { 4121 struct sigacts *ps; 4122 4123 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 4124 refcount_init(&ps->ps_refcnt, 1); 4125 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 4126 return (ps); 4127 } 4128 4129 void 4130 sigacts_free(struct sigacts *ps) 4131 { 4132 4133 if (refcount_release(&ps->ps_refcnt) == 0) 4134 return; 4135 mtx_destroy(&ps->ps_mtx); 4136 free(ps, M_SUBPROC); 4137 } 4138 4139 struct sigacts * 4140 sigacts_hold(struct sigacts *ps) 4141 { 4142 4143 refcount_acquire(&ps->ps_refcnt); 4144 return (ps); 4145 } 4146 4147 void 4148 sigacts_copy(struct sigacts *dest, struct sigacts *src) 4149 { 4150 4151 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 4152 mtx_lock(&src->ps_mtx); 4153 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 4154 mtx_unlock(&src->ps_mtx); 4155 } 4156 4157 int 4158 sigacts_shared(struct sigacts *ps) 4159 { 4160 4161 return (ps->ps_refcnt > 1); 4162 } 4163 4164 void 4165 sig_drop_caught(struct proc *p) 4166 { 4167 int sig; 4168 struct sigacts *ps; 4169 4170 ps = p->p_sigacts; 4171 PROC_LOCK_ASSERT(p, MA_OWNED); 4172 mtx_assert(&ps->ps_mtx, MA_OWNED); 4173 SIG_FOREACH(sig, &ps->ps_sigcatch) { 4174 sigdflt(ps, sig); 4175 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 4176 sigqueue_delete_proc(p, sig); 4177 } 4178 } 4179 4180 static void 4181 sigfastblock_failed(struct thread *td, bool sendsig, bool write) 4182 { 4183 ksiginfo_t ksi; 4184 4185 /* 4186 * Prevent further fetches and SIGSEGVs, allowing thread to 4187 * issue syscalls despite corruption. 4188 */ 4189 sigfastblock_clear(td); 4190 4191 if (!sendsig) 4192 return; 4193 ksiginfo_init_trap(&ksi); 4194 ksi.ksi_signo = SIGSEGV; 4195 ksi.ksi_code = write ? SEGV_ACCERR : SEGV_MAPERR; 4196 ksi.ksi_addr = td->td_sigblock_ptr; 4197 trapsignal(td, &ksi); 4198 } 4199 4200 static bool 4201 sigfastblock_fetch_sig(struct thread *td, bool sendsig, uint32_t *valp) 4202 { 4203 uint32_t res; 4204 4205 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4206 return (true); 4207 if (fueword32((void *)td->td_sigblock_ptr, &res) == -1) { 4208 sigfastblock_failed(td, sendsig, false); 4209 return (false); 4210 } 4211 *valp = res; 4212 td->td_sigblock_val = res & ~SIGFASTBLOCK_FLAGS; 4213 return (true); 4214 } 4215 4216 static void 4217 sigfastblock_resched(struct thread *td, bool resched) 4218 { 4219 struct proc *p; 4220 4221 if (resched) { 4222 p = td->td_proc; 4223 PROC_LOCK(p); 4224 reschedule_signals(p, td->td_sigmask, 0); 4225 PROC_UNLOCK(p); 4226 } 4227 thread_lock(td); 4228 td->td_flags |= TDF_ASTPENDING | TDF_NEEDSIGCHK; 4229 thread_unlock(td); 4230 } 4231 4232 int 4233 sys_sigfastblock(struct thread *td, struct sigfastblock_args *uap) 4234 { 4235 struct proc *p; 4236 int error, res; 4237 uint32_t oldval; 4238 4239 error = 0; 4240 p = td->td_proc; 4241 switch (uap->cmd) { 4242 case SIGFASTBLOCK_SETPTR: 4243 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 4244 error = EBUSY; 4245 break; 4246 } 4247 if (((uintptr_t)(uap->ptr) & (sizeof(uint32_t) - 1)) != 0) { 4248 error = EINVAL; 4249 break; 4250 } 4251 td->td_pflags |= TDP_SIGFASTBLOCK; 4252 td->td_sigblock_ptr = uap->ptr; 4253 break; 4254 4255 case SIGFASTBLOCK_UNBLOCK: 4256 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4257 error = EINVAL; 4258 break; 4259 } 4260 4261 for (;;) { 4262 res = casueword32(td->td_sigblock_ptr, 4263 SIGFASTBLOCK_PEND, &oldval, 0); 4264 if (res == -1) { 4265 error = EFAULT; 4266 sigfastblock_failed(td, false, true); 4267 break; 4268 } 4269 if (res == 0) 4270 break; 4271 MPASS(res == 1); 4272 if (oldval != SIGFASTBLOCK_PEND) { 4273 error = EBUSY; 4274 break; 4275 } 4276 error = thread_check_susp(td, false); 4277 if (error != 0) 4278 break; 4279 } 4280 if (error != 0) 4281 break; 4282 4283 /* 4284 * td_sigblock_val is cleared there, but not on a 4285 * syscall exit. The end effect is that a single 4286 * interruptible sleep, while user sigblock word is 4287 * set, might return EINTR or ERESTART to usermode 4288 * without delivering signal. All further sleeps, 4289 * until userspace clears the word and does 4290 * sigfastblock(UNBLOCK), observe current word and no 4291 * longer get interrupted. It is slight 4292 * non-conformance, with alternative to have read the 4293 * sigblock word on each syscall entry. 4294 */ 4295 td->td_sigblock_val = 0; 4296 4297 /* 4298 * Rely on normal ast mechanism to deliver pending 4299 * signals to current thread. But notify others about 4300 * fake unblock. 4301 */ 4302 sigfastblock_resched(td, error == 0 && p->p_numthreads != 1); 4303 4304 break; 4305 4306 case SIGFASTBLOCK_UNSETPTR: 4307 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4308 error = EINVAL; 4309 break; 4310 } 4311 if (!sigfastblock_fetch_sig(td, false, &oldval)) { 4312 error = EFAULT; 4313 break; 4314 } 4315 if (oldval != 0 && oldval != SIGFASTBLOCK_PEND) { 4316 error = EBUSY; 4317 break; 4318 } 4319 sigfastblock_clear(td); 4320 break; 4321 4322 default: 4323 error = EINVAL; 4324 break; 4325 } 4326 return (error); 4327 } 4328 4329 void 4330 sigfastblock_clear(struct thread *td) 4331 { 4332 bool resched; 4333 4334 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4335 return; 4336 td->td_sigblock_val = 0; 4337 resched = (td->td_pflags & TDP_SIGFASTPENDING) != 0 || 4338 SIGPENDING(td); 4339 td->td_pflags &= ~(TDP_SIGFASTBLOCK | TDP_SIGFASTPENDING); 4340 sigfastblock_resched(td, resched); 4341 } 4342 4343 void 4344 sigfastblock_fetch(struct thread *td) 4345 { 4346 uint32_t val; 4347 4348 (void)sigfastblock_fetch_sig(td, true, &val); 4349 } 4350 4351 static void 4352 sigfastblock_setpend1(struct thread *td) 4353 { 4354 int res; 4355 uint32_t oldval; 4356 4357 if ((td->td_pflags & TDP_SIGFASTPENDING) == 0) 4358 return; 4359 res = fueword32((void *)td->td_sigblock_ptr, &oldval); 4360 if (res == -1) { 4361 sigfastblock_failed(td, true, false); 4362 return; 4363 } 4364 for (;;) { 4365 res = casueword32(td->td_sigblock_ptr, oldval, &oldval, 4366 oldval | SIGFASTBLOCK_PEND); 4367 if (res == -1) { 4368 sigfastblock_failed(td, true, true); 4369 return; 4370 } 4371 if (res == 0) { 4372 td->td_sigblock_val = oldval & ~SIGFASTBLOCK_FLAGS; 4373 td->td_pflags &= ~TDP_SIGFASTPENDING; 4374 break; 4375 } 4376 MPASS(res == 1); 4377 if (thread_check_susp(td, false) != 0) 4378 break; 4379 } 4380 } 4381 4382 void 4383 sigfastblock_setpend(struct thread *td, bool resched) 4384 { 4385 struct proc *p; 4386 4387 sigfastblock_setpend1(td); 4388 if (resched) { 4389 p = td->td_proc; 4390 PROC_LOCK(p); 4391 reschedule_signals(p, fastblock_mask, SIGPROCMASK_FASTBLK); 4392 PROC_UNLOCK(p); 4393 } 4394 } 4395