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; 296 if (! wait) 297 flags |= M_NOWAIT; 298 if (ksiginfo_zone != NULL) 299 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 300 return (NULL); 301 } 302 303 void 304 ksiginfo_free(ksiginfo_t *ksi) 305 { 306 uma_zfree(ksiginfo_zone, ksi); 307 } 308 309 static __inline int 310 ksiginfo_tryfree(ksiginfo_t *ksi) 311 { 312 if (!(ksi->ksi_flags & KSI_EXT)) { 313 uma_zfree(ksiginfo_zone, ksi); 314 return (1); 315 } 316 return (0); 317 } 318 319 void 320 sigqueue_init(sigqueue_t *list, struct proc *p) 321 { 322 SIGEMPTYSET(list->sq_signals); 323 SIGEMPTYSET(list->sq_kill); 324 SIGEMPTYSET(list->sq_ptrace); 325 TAILQ_INIT(&list->sq_list); 326 list->sq_proc = p; 327 list->sq_flags = SQ_INIT; 328 } 329 330 /* 331 * Get a signal's ksiginfo. 332 * Return: 333 * 0 - signal not found 334 * others - signal number 335 */ 336 static int 337 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 338 { 339 struct proc *p = sq->sq_proc; 340 struct ksiginfo *ksi, *next; 341 int count = 0; 342 343 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 344 345 if (!SIGISMEMBER(sq->sq_signals, signo)) 346 return (0); 347 348 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 349 count++; 350 SIGDELSET(sq->sq_ptrace, signo); 351 si->ksi_flags |= KSI_PTRACE; 352 } 353 if (SIGISMEMBER(sq->sq_kill, signo)) { 354 count++; 355 if (count == 1) 356 SIGDELSET(sq->sq_kill, signo); 357 } 358 359 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 360 if (ksi->ksi_signo == signo) { 361 if (count == 0) { 362 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 363 ksi->ksi_sigq = NULL; 364 ksiginfo_copy(ksi, si); 365 if (ksiginfo_tryfree(ksi) && p != NULL) 366 p->p_pendingcnt--; 367 } 368 if (++count > 1) 369 break; 370 } 371 } 372 373 if (count <= 1) 374 SIGDELSET(sq->sq_signals, signo); 375 si->ksi_signo = signo; 376 return (signo); 377 } 378 379 void 380 sigqueue_take(ksiginfo_t *ksi) 381 { 382 struct ksiginfo *kp; 383 struct proc *p; 384 sigqueue_t *sq; 385 386 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 387 return; 388 389 p = sq->sq_proc; 390 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 391 ksi->ksi_sigq = NULL; 392 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 393 p->p_pendingcnt--; 394 395 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 396 kp = TAILQ_NEXT(kp, ksi_link)) { 397 if (kp->ksi_signo == ksi->ksi_signo) 398 break; 399 } 400 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 401 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 402 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 403 } 404 405 static int 406 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 407 { 408 struct proc *p = sq->sq_proc; 409 struct ksiginfo *ksi; 410 int ret = 0; 411 412 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 413 414 /* 415 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 416 * for these signals. 417 */ 418 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 419 SIGADDSET(sq->sq_kill, signo); 420 goto out_set_bit; 421 } 422 423 /* directly insert the ksi, don't copy it */ 424 if (si->ksi_flags & KSI_INS) { 425 if (si->ksi_flags & KSI_HEAD) 426 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 427 else 428 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 429 si->ksi_sigq = sq; 430 goto out_set_bit; 431 } 432 433 if (__predict_false(ksiginfo_zone == NULL)) { 434 SIGADDSET(sq->sq_kill, signo); 435 goto out_set_bit; 436 } 437 438 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 439 signal_overflow++; 440 ret = EAGAIN; 441 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 442 signal_alloc_fail++; 443 ret = EAGAIN; 444 } else { 445 if (p != NULL) 446 p->p_pendingcnt++; 447 ksiginfo_copy(si, ksi); 448 ksi->ksi_signo = signo; 449 if (si->ksi_flags & KSI_HEAD) 450 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 451 else 452 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 453 ksi->ksi_sigq = sq; 454 } 455 456 if (ret != 0) { 457 if ((si->ksi_flags & KSI_PTRACE) != 0) { 458 SIGADDSET(sq->sq_ptrace, signo); 459 ret = 0; 460 goto out_set_bit; 461 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 462 (si->ksi_flags & KSI_SIGQ) == 0) { 463 SIGADDSET(sq->sq_kill, signo); 464 ret = 0; 465 goto out_set_bit; 466 } 467 return (ret); 468 } 469 470 out_set_bit: 471 SIGADDSET(sq->sq_signals, signo); 472 return (ret); 473 } 474 475 void 476 sigqueue_flush(sigqueue_t *sq) 477 { 478 struct proc *p = sq->sq_proc; 479 ksiginfo_t *ksi; 480 481 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 482 483 if (p != NULL) 484 PROC_LOCK_ASSERT(p, MA_OWNED); 485 486 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 487 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 488 ksi->ksi_sigq = NULL; 489 if (ksiginfo_tryfree(ksi) && p != NULL) 490 p->p_pendingcnt--; 491 } 492 493 SIGEMPTYSET(sq->sq_signals); 494 SIGEMPTYSET(sq->sq_kill); 495 SIGEMPTYSET(sq->sq_ptrace); 496 } 497 498 static void 499 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 500 { 501 sigset_t tmp; 502 struct proc *p1, *p2; 503 ksiginfo_t *ksi, *next; 504 505 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 506 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 507 p1 = src->sq_proc; 508 p2 = dst->sq_proc; 509 /* Move siginfo to target list */ 510 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 511 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 512 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 513 if (p1 != NULL) 514 p1->p_pendingcnt--; 515 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 516 ksi->ksi_sigq = dst; 517 if (p2 != NULL) 518 p2->p_pendingcnt++; 519 } 520 } 521 522 /* Move pending bits to target list */ 523 tmp = src->sq_kill; 524 SIGSETAND(tmp, *set); 525 SIGSETOR(dst->sq_kill, tmp); 526 SIGSETNAND(src->sq_kill, tmp); 527 528 tmp = src->sq_ptrace; 529 SIGSETAND(tmp, *set); 530 SIGSETOR(dst->sq_ptrace, tmp); 531 SIGSETNAND(src->sq_ptrace, tmp); 532 533 tmp = src->sq_signals; 534 SIGSETAND(tmp, *set); 535 SIGSETOR(dst->sq_signals, tmp); 536 SIGSETNAND(src->sq_signals, tmp); 537 } 538 539 #if 0 540 static void 541 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 542 { 543 sigset_t set; 544 545 SIGEMPTYSET(set); 546 SIGADDSET(set, signo); 547 sigqueue_move_set(src, dst, &set); 548 } 549 #endif 550 551 static void 552 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 553 { 554 struct proc *p = sq->sq_proc; 555 ksiginfo_t *ksi, *next; 556 557 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 558 559 /* Remove siginfo queue */ 560 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 561 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 562 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 563 ksi->ksi_sigq = NULL; 564 if (ksiginfo_tryfree(ksi) && p != NULL) 565 p->p_pendingcnt--; 566 } 567 } 568 SIGSETNAND(sq->sq_kill, *set); 569 SIGSETNAND(sq->sq_ptrace, *set); 570 SIGSETNAND(sq->sq_signals, *set); 571 } 572 573 void 574 sigqueue_delete(sigqueue_t *sq, int signo) 575 { 576 sigset_t set; 577 578 SIGEMPTYSET(set); 579 SIGADDSET(set, signo); 580 sigqueue_delete_set(sq, &set); 581 } 582 583 /* Remove a set of signals for a process */ 584 static void 585 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 586 { 587 sigqueue_t worklist; 588 struct thread *td0; 589 590 PROC_LOCK_ASSERT(p, MA_OWNED); 591 592 sigqueue_init(&worklist, NULL); 593 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 594 595 FOREACH_THREAD_IN_PROC(p, td0) 596 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 597 598 sigqueue_flush(&worklist); 599 } 600 601 void 602 sigqueue_delete_proc(struct proc *p, int signo) 603 { 604 sigset_t set; 605 606 SIGEMPTYSET(set); 607 SIGADDSET(set, signo); 608 sigqueue_delete_set_proc(p, &set); 609 } 610 611 static void 612 sigqueue_delete_stopmask_proc(struct proc *p) 613 { 614 sigset_t set; 615 616 SIGEMPTYSET(set); 617 SIGADDSET(set, SIGSTOP); 618 SIGADDSET(set, SIGTSTP); 619 SIGADDSET(set, SIGTTIN); 620 SIGADDSET(set, SIGTTOU); 621 sigqueue_delete_set_proc(p, &set); 622 } 623 624 /* 625 * Determine signal that should be delivered to thread td, the current 626 * thread, 0 if none. If there is a pending stop signal with default 627 * action, the process stops in issignal(). 628 */ 629 int 630 cursig(struct thread *td) 631 { 632 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 633 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 634 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 635 return (SIGPENDING(td) ? issignal(td) : 0); 636 } 637 638 /* 639 * Arrange for ast() to handle unmasked pending signals on return to user 640 * mode. This must be called whenever a signal is added to td_sigqueue or 641 * unmasked in td_sigmask. 642 */ 643 void 644 signotify(struct thread *td) 645 { 646 647 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 648 649 if (SIGPENDING(td)) { 650 thread_lock(td); 651 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 652 thread_unlock(td); 653 } 654 } 655 656 /* 657 * Returns 1 (true) if altstack is configured for the thread, and the 658 * passed stack bottom address falls into the altstack range. Handles 659 * the 43 compat special case where the alt stack size is zero. 660 */ 661 int 662 sigonstack(size_t sp) 663 { 664 struct thread *td; 665 666 td = curthread; 667 if ((td->td_pflags & TDP_ALTSTACK) == 0) 668 return (0); 669 #if defined(COMPAT_43) 670 if (SV_PROC_FLAG(td->td_proc, SV_AOUT) && td->td_sigstk.ss_size == 0) 671 return ((td->td_sigstk.ss_flags & SS_ONSTACK) != 0); 672 #endif 673 return (sp >= (size_t)td->td_sigstk.ss_sp && 674 sp < td->td_sigstk.ss_size + (size_t)td->td_sigstk.ss_sp); 675 } 676 677 static __inline int 678 sigprop(int sig) 679 { 680 681 if (sig > 0 && sig < nitems(sigproptbl)) 682 return (sigproptbl[sig]); 683 return (0); 684 } 685 686 static bool 687 sigact_flag_test(const struct sigaction *act, int flag) 688 { 689 690 /* 691 * SA_SIGINFO is reset when signal disposition is set to 692 * ignore or default. Other flags are kept according to user 693 * settings. 694 */ 695 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 696 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 697 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 698 } 699 700 /* 701 * kern_sigaction 702 * sigaction 703 * freebsd4_sigaction 704 * osigaction 705 */ 706 int 707 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 708 struct sigaction *oact, int flags) 709 { 710 struct sigacts *ps; 711 struct proc *p = td->td_proc; 712 713 if (!_SIG_VALID(sig)) 714 return (EINVAL); 715 if (act != NULL && act->sa_handler != SIG_DFL && 716 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 717 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 718 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 719 return (EINVAL); 720 721 PROC_LOCK(p); 722 ps = p->p_sigacts; 723 mtx_lock(&ps->ps_mtx); 724 if (oact) { 725 memset(oact, 0, sizeof(*oact)); 726 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 727 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 728 oact->sa_flags |= SA_ONSTACK; 729 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 730 oact->sa_flags |= SA_RESTART; 731 if (SIGISMEMBER(ps->ps_sigreset, sig)) 732 oact->sa_flags |= SA_RESETHAND; 733 if (SIGISMEMBER(ps->ps_signodefer, sig)) 734 oact->sa_flags |= SA_NODEFER; 735 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 736 oact->sa_flags |= SA_SIGINFO; 737 oact->sa_sigaction = 738 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 739 } else 740 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 741 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 742 oact->sa_flags |= SA_NOCLDSTOP; 743 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 744 oact->sa_flags |= SA_NOCLDWAIT; 745 } 746 if (act) { 747 if ((sig == SIGKILL || sig == SIGSTOP) && 748 act->sa_handler != SIG_DFL) { 749 mtx_unlock(&ps->ps_mtx); 750 PROC_UNLOCK(p); 751 return (EINVAL); 752 } 753 754 /* 755 * Change setting atomically. 756 */ 757 758 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 759 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 760 if (sigact_flag_test(act, SA_SIGINFO)) { 761 ps->ps_sigact[_SIG_IDX(sig)] = 762 (__sighandler_t *)act->sa_sigaction; 763 SIGADDSET(ps->ps_siginfo, sig); 764 } else { 765 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 766 SIGDELSET(ps->ps_siginfo, sig); 767 } 768 if (!sigact_flag_test(act, SA_RESTART)) 769 SIGADDSET(ps->ps_sigintr, sig); 770 else 771 SIGDELSET(ps->ps_sigintr, sig); 772 if (sigact_flag_test(act, SA_ONSTACK)) 773 SIGADDSET(ps->ps_sigonstack, sig); 774 else 775 SIGDELSET(ps->ps_sigonstack, sig); 776 if (sigact_flag_test(act, SA_RESETHAND)) 777 SIGADDSET(ps->ps_sigreset, sig); 778 else 779 SIGDELSET(ps->ps_sigreset, sig); 780 if (sigact_flag_test(act, SA_NODEFER)) 781 SIGADDSET(ps->ps_signodefer, sig); 782 else 783 SIGDELSET(ps->ps_signodefer, sig); 784 if (sig == SIGCHLD) { 785 if (act->sa_flags & SA_NOCLDSTOP) 786 ps->ps_flag |= PS_NOCLDSTOP; 787 else 788 ps->ps_flag &= ~PS_NOCLDSTOP; 789 if (act->sa_flags & SA_NOCLDWAIT) { 790 /* 791 * Paranoia: since SA_NOCLDWAIT is implemented 792 * by reparenting the dying child to PID 1 (and 793 * trust it to reap the zombie), PID 1 itself 794 * is forbidden to set SA_NOCLDWAIT. 795 */ 796 if (p->p_pid == 1) 797 ps->ps_flag &= ~PS_NOCLDWAIT; 798 else 799 ps->ps_flag |= PS_NOCLDWAIT; 800 } else 801 ps->ps_flag &= ~PS_NOCLDWAIT; 802 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 803 ps->ps_flag |= PS_CLDSIGIGN; 804 else 805 ps->ps_flag &= ~PS_CLDSIGIGN; 806 } 807 /* 808 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 809 * and for signals set to SIG_DFL where the default is to 810 * ignore. However, don't put SIGCONT in ps_sigignore, as we 811 * have to restart the process. 812 */ 813 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 814 (sigprop(sig) & SIGPROP_IGNORE && 815 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 816 /* never to be seen again */ 817 sigqueue_delete_proc(p, sig); 818 if (sig != SIGCONT) 819 /* easier in psignal */ 820 SIGADDSET(ps->ps_sigignore, sig); 821 SIGDELSET(ps->ps_sigcatch, sig); 822 } else { 823 SIGDELSET(ps->ps_sigignore, sig); 824 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 825 SIGDELSET(ps->ps_sigcatch, sig); 826 else 827 SIGADDSET(ps->ps_sigcatch, sig); 828 } 829 #ifdef COMPAT_FREEBSD4 830 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 831 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 832 (flags & KSA_FREEBSD4) == 0) 833 SIGDELSET(ps->ps_freebsd4, sig); 834 else 835 SIGADDSET(ps->ps_freebsd4, sig); 836 #endif 837 #ifdef COMPAT_43 838 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 839 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 840 (flags & KSA_OSIGSET) == 0) 841 SIGDELSET(ps->ps_osigset, sig); 842 else 843 SIGADDSET(ps->ps_osigset, sig); 844 #endif 845 } 846 mtx_unlock(&ps->ps_mtx); 847 PROC_UNLOCK(p); 848 return (0); 849 } 850 851 #ifndef _SYS_SYSPROTO_H_ 852 struct sigaction_args { 853 int sig; 854 struct sigaction *act; 855 struct sigaction *oact; 856 }; 857 #endif 858 int 859 sys_sigaction(struct thread *td, struct sigaction_args *uap) 860 { 861 struct sigaction act, oact; 862 struct sigaction *actp, *oactp; 863 int error; 864 865 actp = (uap->act != NULL) ? &act : NULL; 866 oactp = (uap->oact != NULL) ? &oact : NULL; 867 if (actp) { 868 error = copyin(uap->act, actp, sizeof(act)); 869 if (error) 870 return (error); 871 } 872 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 873 if (oactp && !error) 874 error = copyout(oactp, uap->oact, sizeof(oact)); 875 return (error); 876 } 877 878 #ifdef COMPAT_FREEBSD4 879 #ifndef _SYS_SYSPROTO_H_ 880 struct freebsd4_sigaction_args { 881 int sig; 882 struct sigaction *act; 883 struct sigaction *oact; 884 }; 885 #endif 886 int 887 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 888 { 889 struct sigaction act, oact; 890 struct sigaction *actp, *oactp; 891 int error; 892 893 actp = (uap->act != NULL) ? &act : NULL; 894 oactp = (uap->oact != NULL) ? &oact : NULL; 895 if (actp) { 896 error = copyin(uap->act, actp, sizeof(act)); 897 if (error) 898 return (error); 899 } 900 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 901 if (oactp && !error) 902 error = copyout(oactp, uap->oact, sizeof(oact)); 903 return (error); 904 } 905 #endif /* COMAPT_FREEBSD4 */ 906 907 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 908 #ifndef _SYS_SYSPROTO_H_ 909 struct osigaction_args { 910 int signum; 911 struct osigaction *nsa; 912 struct osigaction *osa; 913 }; 914 #endif 915 int 916 osigaction(struct thread *td, struct osigaction_args *uap) 917 { 918 struct osigaction sa; 919 struct sigaction nsa, osa; 920 struct sigaction *nsap, *osap; 921 int error; 922 923 if (uap->signum <= 0 || uap->signum >= ONSIG) 924 return (EINVAL); 925 926 nsap = (uap->nsa != NULL) ? &nsa : NULL; 927 osap = (uap->osa != NULL) ? &osa : NULL; 928 929 if (nsap) { 930 error = copyin(uap->nsa, &sa, sizeof(sa)); 931 if (error) 932 return (error); 933 nsap->sa_handler = sa.sa_handler; 934 nsap->sa_flags = sa.sa_flags; 935 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 936 } 937 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 938 if (osap && !error) { 939 sa.sa_handler = osap->sa_handler; 940 sa.sa_flags = osap->sa_flags; 941 SIG2OSIG(osap->sa_mask, sa.sa_mask); 942 error = copyout(&sa, uap->osa, sizeof(sa)); 943 } 944 return (error); 945 } 946 947 #if !defined(__i386__) 948 /* Avoid replicating the same stub everywhere */ 949 int 950 osigreturn(struct thread *td, struct osigreturn_args *uap) 951 { 952 953 return (nosys(td, (struct nosys_args *)uap)); 954 } 955 #endif 956 #endif /* COMPAT_43 */ 957 958 /* 959 * Initialize signal state for process 0; 960 * set to ignore signals that are ignored by default. 961 */ 962 void 963 siginit(struct proc *p) 964 { 965 int i; 966 struct sigacts *ps; 967 968 PROC_LOCK(p); 969 ps = p->p_sigacts; 970 mtx_lock(&ps->ps_mtx); 971 for (i = 1; i <= NSIG; i++) { 972 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 973 SIGADDSET(ps->ps_sigignore, i); 974 } 975 } 976 mtx_unlock(&ps->ps_mtx); 977 PROC_UNLOCK(p); 978 } 979 980 /* 981 * Reset specified signal to the default disposition. 982 */ 983 static void 984 sigdflt(struct sigacts *ps, int sig) 985 { 986 987 mtx_assert(&ps->ps_mtx, MA_OWNED); 988 SIGDELSET(ps->ps_sigcatch, sig); 989 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 990 SIGADDSET(ps->ps_sigignore, sig); 991 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 992 SIGDELSET(ps->ps_siginfo, sig); 993 } 994 995 /* 996 * Reset signals for an exec of the specified process. 997 */ 998 void 999 execsigs(struct proc *p) 1000 { 1001 struct sigacts *ps; 1002 struct thread *td; 1003 1004 /* 1005 * Reset caught signals. Held signals remain held 1006 * through td_sigmask (unless they were caught, 1007 * and are now ignored by default). 1008 */ 1009 PROC_LOCK_ASSERT(p, MA_OWNED); 1010 ps = p->p_sigacts; 1011 mtx_lock(&ps->ps_mtx); 1012 sig_drop_caught(p); 1013 1014 /* 1015 * Reset stack state to the user stack. 1016 * Clear set of signals caught on the signal stack. 1017 */ 1018 td = curthread; 1019 MPASS(td->td_proc == p); 1020 td->td_sigstk.ss_flags = SS_DISABLE; 1021 td->td_sigstk.ss_size = 0; 1022 td->td_sigstk.ss_sp = 0; 1023 td->td_pflags &= ~TDP_ALTSTACK; 1024 /* 1025 * Reset no zombies if child dies flag as Solaris does. 1026 */ 1027 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1028 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1029 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1030 mtx_unlock(&ps->ps_mtx); 1031 } 1032 1033 /* 1034 * kern_sigprocmask() 1035 * 1036 * Manipulate signal mask. 1037 */ 1038 int 1039 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1040 int flags) 1041 { 1042 sigset_t new_block, oset1; 1043 struct proc *p; 1044 int error; 1045 1046 p = td->td_proc; 1047 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1048 PROC_LOCK_ASSERT(p, MA_OWNED); 1049 else 1050 PROC_LOCK(p); 1051 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1052 ? MA_OWNED : MA_NOTOWNED); 1053 if (oset != NULL) 1054 *oset = td->td_sigmask; 1055 1056 error = 0; 1057 if (set != NULL) { 1058 switch (how) { 1059 case SIG_BLOCK: 1060 SIG_CANTMASK(*set); 1061 oset1 = td->td_sigmask; 1062 SIGSETOR(td->td_sigmask, *set); 1063 new_block = td->td_sigmask; 1064 SIGSETNAND(new_block, oset1); 1065 break; 1066 case SIG_UNBLOCK: 1067 SIGSETNAND(td->td_sigmask, *set); 1068 signotify(td); 1069 goto out; 1070 case SIG_SETMASK: 1071 SIG_CANTMASK(*set); 1072 oset1 = td->td_sigmask; 1073 if (flags & SIGPROCMASK_OLD) 1074 SIGSETLO(td->td_sigmask, *set); 1075 else 1076 td->td_sigmask = *set; 1077 new_block = td->td_sigmask; 1078 SIGSETNAND(new_block, oset1); 1079 signotify(td); 1080 break; 1081 default: 1082 error = EINVAL; 1083 goto out; 1084 } 1085 1086 /* 1087 * The new_block set contains signals that were not previously 1088 * blocked, but are blocked now. 1089 * 1090 * In case we block any signal that was not previously blocked 1091 * for td, and process has the signal pending, try to schedule 1092 * signal delivery to some thread that does not block the 1093 * signal, possibly waking it up. 1094 */ 1095 if (p->p_numthreads != 1) 1096 reschedule_signals(p, new_block, flags); 1097 } 1098 1099 out: 1100 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1101 PROC_UNLOCK(p); 1102 return (error); 1103 } 1104 1105 #ifndef _SYS_SYSPROTO_H_ 1106 struct sigprocmask_args { 1107 int how; 1108 const sigset_t *set; 1109 sigset_t *oset; 1110 }; 1111 #endif 1112 int 1113 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1114 { 1115 sigset_t set, oset; 1116 sigset_t *setp, *osetp; 1117 int error; 1118 1119 setp = (uap->set != NULL) ? &set : NULL; 1120 osetp = (uap->oset != NULL) ? &oset : NULL; 1121 if (setp) { 1122 error = copyin(uap->set, setp, sizeof(set)); 1123 if (error) 1124 return (error); 1125 } 1126 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1127 if (osetp && !error) { 1128 error = copyout(osetp, uap->oset, sizeof(oset)); 1129 } 1130 return (error); 1131 } 1132 1133 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1134 #ifndef _SYS_SYSPROTO_H_ 1135 struct osigprocmask_args { 1136 int how; 1137 osigset_t mask; 1138 }; 1139 #endif 1140 int 1141 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1142 { 1143 sigset_t set, oset; 1144 int error; 1145 1146 OSIG2SIG(uap->mask, set); 1147 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1148 SIG2OSIG(oset, td->td_retval[0]); 1149 return (error); 1150 } 1151 #endif /* COMPAT_43 */ 1152 1153 int 1154 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1155 { 1156 ksiginfo_t ksi; 1157 sigset_t set; 1158 int error; 1159 1160 error = copyin(uap->set, &set, sizeof(set)); 1161 if (error) { 1162 td->td_retval[0] = error; 1163 return (0); 1164 } 1165 1166 error = kern_sigtimedwait(td, set, &ksi, NULL); 1167 if (error) { 1168 /* 1169 * sigwait() function shall not return EINTR, but 1170 * the syscall does. Non-ancient libc provides the 1171 * wrapper which hides EINTR. Otherwise, EINTR return 1172 * is used by libthr to handle required cancellation 1173 * point in the sigwait(). 1174 */ 1175 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1176 return (ERESTART); 1177 td->td_retval[0] = error; 1178 return (0); 1179 } 1180 1181 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1182 td->td_retval[0] = error; 1183 return (0); 1184 } 1185 1186 int 1187 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1188 { 1189 struct timespec ts; 1190 struct timespec *timeout; 1191 sigset_t set; 1192 ksiginfo_t ksi; 1193 int error; 1194 1195 if (uap->timeout) { 1196 error = copyin(uap->timeout, &ts, sizeof(ts)); 1197 if (error) 1198 return (error); 1199 1200 timeout = &ts; 1201 } else 1202 timeout = NULL; 1203 1204 error = copyin(uap->set, &set, sizeof(set)); 1205 if (error) 1206 return (error); 1207 1208 error = kern_sigtimedwait(td, set, &ksi, timeout); 1209 if (error) 1210 return (error); 1211 1212 if (uap->info) 1213 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1214 1215 if (error == 0) 1216 td->td_retval[0] = ksi.ksi_signo; 1217 return (error); 1218 } 1219 1220 int 1221 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1222 { 1223 ksiginfo_t ksi; 1224 sigset_t set; 1225 int error; 1226 1227 error = copyin(uap->set, &set, sizeof(set)); 1228 if (error) 1229 return (error); 1230 1231 error = kern_sigtimedwait(td, set, &ksi, NULL); 1232 if (error) 1233 return (error); 1234 1235 if (uap->info) 1236 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1237 1238 if (error == 0) 1239 td->td_retval[0] = ksi.ksi_signo; 1240 return (error); 1241 } 1242 1243 static void 1244 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1245 { 1246 struct thread *thr; 1247 1248 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1249 if (thr == td) 1250 thr->td_si = *si; 1251 else 1252 thr->td_si.si_signo = 0; 1253 } 1254 } 1255 1256 int 1257 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1258 struct timespec *timeout) 1259 { 1260 struct sigacts *ps; 1261 sigset_t saved_mask, new_block; 1262 struct proc *p; 1263 int error, sig, timo, timevalid = 0; 1264 struct timespec rts, ets, ts; 1265 struct timeval tv; 1266 bool traced; 1267 1268 p = td->td_proc; 1269 error = 0; 1270 ets.tv_sec = 0; 1271 ets.tv_nsec = 0; 1272 traced = false; 1273 1274 /* Ensure the sigfastblock value is up to date. */ 1275 sigfastblock_fetch(td); 1276 1277 if (timeout != NULL) { 1278 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1279 timevalid = 1; 1280 getnanouptime(&rts); 1281 timespecadd(&rts, timeout, &ets); 1282 } 1283 } 1284 ksiginfo_init(ksi); 1285 /* Some signals can not be waited for. */ 1286 SIG_CANTMASK(waitset); 1287 ps = p->p_sigacts; 1288 PROC_LOCK(p); 1289 saved_mask = td->td_sigmask; 1290 SIGSETNAND(td->td_sigmask, waitset); 1291 if ((p->p_sysent->sv_flags & SV_SIG_DISCIGN) != 0 || 1292 !kern_sig_discard_ign) { 1293 thread_lock(td); 1294 td->td_flags |= TDF_SIGWAIT; 1295 thread_unlock(td); 1296 } 1297 for (;;) { 1298 mtx_lock(&ps->ps_mtx); 1299 sig = cursig(td); 1300 mtx_unlock(&ps->ps_mtx); 1301 KASSERT(sig >= 0, ("sig %d", sig)); 1302 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1303 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1304 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1305 error = 0; 1306 break; 1307 } 1308 } 1309 1310 if (error != 0) 1311 break; 1312 1313 /* 1314 * POSIX says this must be checked after looking for pending 1315 * signals. 1316 */ 1317 if (timeout != NULL) { 1318 if (!timevalid) { 1319 error = EINVAL; 1320 break; 1321 } 1322 getnanouptime(&rts); 1323 if (timespeccmp(&rts, &ets, >=)) { 1324 error = EAGAIN; 1325 break; 1326 } 1327 timespecsub(&ets, &rts, &ts); 1328 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1329 timo = tvtohz(&tv); 1330 } else { 1331 timo = 0; 1332 } 1333 1334 if (traced) { 1335 error = EINTR; 1336 break; 1337 } 1338 1339 error = msleep(&p->p_sigacts, &p->p_mtx, PPAUSE | PCATCH, 1340 "sigwait", timo); 1341 1342 /* The syscalls can not be restarted. */ 1343 if (error == ERESTART) 1344 error = EINTR; 1345 1346 /* We will calculate timeout by ourself. */ 1347 if (timeout != NULL && error == EAGAIN) 1348 error = 0; 1349 1350 /* 1351 * If PTRACE_SCE or PTRACE_SCX were set after 1352 * userspace entered the syscall, return spurious 1353 * EINTR after wait was done. Only do this as last 1354 * resort after rechecking for possible queued signals 1355 * and expired timeouts. 1356 */ 1357 if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0) 1358 traced = true; 1359 } 1360 thread_lock(td); 1361 td->td_flags &= ~TDF_SIGWAIT; 1362 thread_unlock(td); 1363 1364 new_block = saved_mask; 1365 SIGSETNAND(new_block, td->td_sigmask); 1366 td->td_sigmask = saved_mask; 1367 /* 1368 * Fewer signals can be delivered to us, reschedule signal 1369 * notification. 1370 */ 1371 if (p->p_numthreads != 1) 1372 reschedule_signals(p, new_block, 0); 1373 1374 if (error == 0) { 1375 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1376 1377 if (ksi->ksi_code == SI_TIMER) 1378 itimer_accept(p, ksi->ksi_timerid, ksi); 1379 1380 #ifdef KTRACE 1381 if (KTRPOINT(td, KTR_PSIG)) { 1382 sig_t action; 1383 1384 mtx_lock(&ps->ps_mtx); 1385 action = ps->ps_sigact[_SIG_IDX(sig)]; 1386 mtx_unlock(&ps->ps_mtx); 1387 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1388 } 1389 #endif 1390 if (sig == SIGKILL) { 1391 proc_td_siginfo_capture(td, &ksi->ksi_info); 1392 sigexit(td, sig); 1393 } 1394 } 1395 PROC_UNLOCK(p); 1396 return (error); 1397 } 1398 1399 #ifndef _SYS_SYSPROTO_H_ 1400 struct sigpending_args { 1401 sigset_t *set; 1402 }; 1403 #endif 1404 int 1405 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1406 { 1407 struct proc *p = td->td_proc; 1408 sigset_t pending; 1409 1410 PROC_LOCK(p); 1411 pending = p->p_sigqueue.sq_signals; 1412 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1413 PROC_UNLOCK(p); 1414 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1415 } 1416 1417 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1418 #ifndef _SYS_SYSPROTO_H_ 1419 struct osigpending_args { 1420 int dummy; 1421 }; 1422 #endif 1423 int 1424 osigpending(struct thread *td, struct osigpending_args *uap) 1425 { 1426 struct proc *p = td->td_proc; 1427 sigset_t pending; 1428 1429 PROC_LOCK(p); 1430 pending = p->p_sigqueue.sq_signals; 1431 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1432 PROC_UNLOCK(p); 1433 SIG2OSIG(pending, td->td_retval[0]); 1434 return (0); 1435 } 1436 #endif /* COMPAT_43 */ 1437 1438 #if defined(COMPAT_43) 1439 /* 1440 * Generalized interface signal handler, 4.3-compatible. 1441 */ 1442 #ifndef _SYS_SYSPROTO_H_ 1443 struct osigvec_args { 1444 int signum; 1445 struct sigvec *nsv; 1446 struct sigvec *osv; 1447 }; 1448 #endif 1449 /* ARGSUSED */ 1450 int 1451 osigvec(struct thread *td, struct osigvec_args *uap) 1452 { 1453 struct sigvec vec; 1454 struct sigaction nsa, osa; 1455 struct sigaction *nsap, *osap; 1456 int error; 1457 1458 if (uap->signum <= 0 || uap->signum >= ONSIG) 1459 return (EINVAL); 1460 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1461 osap = (uap->osv != NULL) ? &osa : NULL; 1462 if (nsap) { 1463 error = copyin(uap->nsv, &vec, sizeof(vec)); 1464 if (error) 1465 return (error); 1466 nsap->sa_handler = vec.sv_handler; 1467 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1468 nsap->sa_flags = vec.sv_flags; 1469 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1470 } 1471 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1472 if (osap && !error) { 1473 vec.sv_handler = osap->sa_handler; 1474 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1475 vec.sv_flags = osap->sa_flags; 1476 vec.sv_flags &= ~SA_NOCLDWAIT; 1477 vec.sv_flags ^= SA_RESTART; 1478 error = copyout(&vec, uap->osv, sizeof(vec)); 1479 } 1480 return (error); 1481 } 1482 1483 #ifndef _SYS_SYSPROTO_H_ 1484 struct osigblock_args { 1485 int mask; 1486 }; 1487 #endif 1488 int 1489 osigblock(struct thread *td, struct osigblock_args *uap) 1490 { 1491 sigset_t set, oset; 1492 1493 OSIG2SIG(uap->mask, set); 1494 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1495 SIG2OSIG(oset, td->td_retval[0]); 1496 return (0); 1497 } 1498 1499 #ifndef _SYS_SYSPROTO_H_ 1500 struct osigsetmask_args { 1501 int mask; 1502 }; 1503 #endif 1504 int 1505 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1506 { 1507 sigset_t set, oset; 1508 1509 OSIG2SIG(uap->mask, set); 1510 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1511 SIG2OSIG(oset, td->td_retval[0]); 1512 return (0); 1513 } 1514 #endif /* COMPAT_43 */ 1515 1516 /* 1517 * Suspend calling thread until signal, providing mask to be set in the 1518 * meantime. 1519 */ 1520 #ifndef _SYS_SYSPROTO_H_ 1521 struct sigsuspend_args { 1522 const sigset_t *sigmask; 1523 }; 1524 #endif 1525 /* ARGSUSED */ 1526 int 1527 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1528 { 1529 sigset_t mask; 1530 int error; 1531 1532 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1533 if (error) 1534 return (error); 1535 return (kern_sigsuspend(td, mask)); 1536 } 1537 1538 int 1539 kern_sigsuspend(struct thread *td, sigset_t mask) 1540 { 1541 struct proc *p = td->td_proc; 1542 int has_sig, sig; 1543 1544 /* Ensure the sigfastblock value is up to date. */ 1545 sigfastblock_fetch(td); 1546 1547 /* 1548 * When returning from sigsuspend, we want 1549 * the old mask to be restored after the 1550 * signal handler has finished. Thus, we 1551 * save it here and mark the sigacts structure 1552 * to indicate this. 1553 */ 1554 PROC_LOCK(p); 1555 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1556 SIGPROCMASK_PROC_LOCKED); 1557 td->td_pflags |= TDP_OLDMASK; 1558 1559 /* 1560 * Process signals now. Otherwise, we can get spurious wakeup 1561 * due to signal entered process queue, but delivered to other 1562 * thread. But sigsuspend should return only on signal 1563 * delivery. 1564 */ 1565 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1566 for (has_sig = 0; !has_sig;) { 1567 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1568 0) == 0) 1569 /* void */; 1570 thread_suspend_check(0); 1571 mtx_lock(&p->p_sigacts->ps_mtx); 1572 while ((sig = cursig(td)) != 0) { 1573 KASSERT(sig >= 0, ("sig %d", sig)); 1574 has_sig += postsig(sig); 1575 } 1576 mtx_unlock(&p->p_sigacts->ps_mtx); 1577 1578 /* 1579 * If PTRACE_SCE or PTRACE_SCX were set after 1580 * userspace entered the syscall, return spurious 1581 * EINTR. 1582 */ 1583 if ((p->p_ptevents & PTRACE_SYSCALL) != 0) 1584 has_sig += 1; 1585 } 1586 PROC_UNLOCK(p); 1587 td->td_errno = EINTR; 1588 td->td_pflags |= TDP_NERRNO; 1589 return (EJUSTRETURN); 1590 } 1591 1592 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1593 /* 1594 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1595 * convention: libc stub passes mask, not pointer, to save a copyin. 1596 */ 1597 #ifndef _SYS_SYSPROTO_H_ 1598 struct osigsuspend_args { 1599 osigset_t mask; 1600 }; 1601 #endif 1602 /* ARGSUSED */ 1603 int 1604 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1605 { 1606 sigset_t mask; 1607 1608 OSIG2SIG(uap->mask, mask); 1609 return (kern_sigsuspend(td, mask)); 1610 } 1611 #endif /* COMPAT_43 */ 1612 1613 #if defined(COMPAT_43) 1614 #ifndef _SYS_SYSPROTO_H_ 1615 struct osigstack_args { 1616 struct sigstack *nss; 1617 struct sigstack *oss; 1618 }; 1619 #endif 1620 /* ARGSUSED */ 1621 int 1622 osigstack(struct thread *td, struct osigstack_args *uap) 1623 { 1624 struct sigstack nss, oss; 1625 int error = 0; 1626 1627 if (uap->nss != NULL) { 1628 error = copyin(uap->nss, &nss, sizeof(nss)); 1629 if (error) 1630 return (error); 1631 } 1632 oss.ss_sp = td->td_sigstk.ss_sp; 1633 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1634 if (uap->nss != NULL) { 1635 td->td_sigstk.ss_sp = nss.ss_sp; 1636 td->td_sigstk.ss_size = 0; 1637 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1638 td->td_pflags |= TDP_ALTSTACK; 1639 } 1640 if (uap->oss != NULL) 1641 error = copyout(&oss, uap->oss, sizeof(oss)); 1642 1643 return (error); 1644 } 1645 #endif /* COMPAT_43 */ 1646 1647 #ifndef _SYS_SYSPROTO_H_ 1648 struct sigaltstack_args { 1649 stack_t *ss; 1650 stack_t *oss; 1651 }; 1652 #endif 1653 /* ARGSUSED */ 1654 int 1655 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1656 { 1657 stack_t ss, oss; 1658 int error; 1659 1660 if (uap->ss != NULL) { 1661 error = copyin(uap->ss, &ss, sizeof(ss)); 1662 if (error) 1663 return (error); 1664 } 1665 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1666 (uap->oss != NULL) ? &oss : NULL); 1667 if (error) 1668 return (error); 1669 if (uap->oss != NULL) 1670 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1671 return (error); 1672 } 1673 1674 int 1675 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1676 { 1677 struct proc *p = td->td_proc; 1678 int oonstack; 1679 1680 oonstack = sigonstack(cpu_getstack(td)); 1681 1682 if (oss != NULL) { 1683 *oss = td->td_sigstk; 1684 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1685 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1686 } 1687 1688 if (ss != NULL) { 1689 if (oonstack) 1690 return (EPERM); 1691 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1692 return (EINVAL); 1693 if (!(ss->ss_flags & SS_DISABLE)) { 1694 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1695 return (ENOMEM); 1696 1697 td->td_sigstk = *ss; 1698 td->td_pflags |= TDP_ALTSTACK; 1699 } else { 1700 td->td_pflags &= ~TDP_ALTSTACK; 1701 } 1702 } 1703 return (0); 1704 } 1705 1706 struct killpg1_ctx { 1707 struct thread *td; 1708 ksiginfo_t *ksi; 1709 int sig; 1710 bool sent; 1711 bool found; 1712 int ret; 1713 }; 1714 1715 static void 1716 killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg) 1717 { 1718 int err; 1719 1720 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 || 1721 (notself && p == arg->td->td_proc) || p->p_state == PRS_NEW) 1722 return; 1723 PROC_LOCK(p); 1724 err = p_cansignal(arg->td, p, arg->sig); 1725 if (err == 0 && arg->sig != 0) 1726 pksignal(p, arg->sig, arg->ksi); 1727 PROC_UNLOCK(p); 1728 if (err != ESRCH) 1729 arg->found = true; 1730 if (err == 0) 1731 arg->sent = true; 1732 else if (arg->ret == 0 && err != ESRCH && err != EPERM) 1733 arg->ret = err; 1734 } 1735 1736 /* 1737 * Common code for kill process group/broadcast kill. 1738 * cp is calling process. 1739 */ 1740 static int 1741 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1742 { 1743 struct proc *p; 1744 struct pgrp *pgrp; 1745 struct killpg1_ctx arg; 1746 1747 arg.td = td; 1748 arg.ksi = ksi; 1749 arg.sig = sig; 1750 arg.sent = false; 1751 arg.found = false; 1752 arg.ret = 0; 1753 if (all) { 1754 /* 1755 * broadcast 1756 */ 1757 sx_slock(&allproc_lock); 1758 FOREACH_PROC_IN_SYSTEM(p) { 1759 killpg1_sendsig(p, true, &arg); 1760 } 1761 sx_sunlock(&allproc_lock); 1762 } else { 1763 sx_slock(&proctree_lock); 1764 if (pgid == 0) { 1765 /* 1766 * zero pgid means send to my process group. 1767 */ 1768 pgrp = td->td_proc->p_pgrp; 1769 PGRP_LOCK(pgrp); 1770 } else { 1771 pgrp = pgfind(pgid); 1772 if (pgrp == NULL) { 1773 sx_sunlock(&proctree_lock); 1774 return (ESRCH); 1775 } 1776 } 1777 sx_sunlock(&proctree_lock); 1778 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1779 killpg1_sendsig(p, false, &arg); 1780 } 1781 PGRP_UNLOCK(pgrp); 1782 } 1783 MPASS(arg.ret != 0 || arg.found || !arg.sent); 1784 if (arg.ret == 0 && !arg.sent) 1785 arg.ret = arg.found ? EPERM : ESRCH; 1786 return (arg.ret); 1787 } 1788 1789 #ifndef _SYS_SYSPROTO_H_ 1790 struct kill_args { 1791 int pid; 1792 int signum; 1793 }; 1794 #endif 1795 /* ARGSUSED */ 1796 int 1797 sys_kill(struct thread *td, struct kill_args *uap) 1798 { 1799 1800 return (kern_kill(td, uap->pid, uap->signum)); 1801 } 1802 1803 int 1804 kern_kill(struct thread *td, pid_t pid, int signum) 1805 { 1806 ksiginfo_t ksi; 1807 struct proc *p; 1808 int error; 1809 1810 /* 1811 * A process in capability mode can send signals only to himself. 1812 * The main rationale behind this is that abort(3) is implemented as 1813 * kill(getpid(), SIGABRT). 1814 */ 1815 if (IN_CAPABILITY_MODE(td) && pid != td->td_proc->p_pid) 1816 return (ECAPMODE); 1817 1818 AUDIT_ARG_SIGNUM(signum); 1819 AUDIT_ARG_PID(pid); 1820 if ((u_int)signum > _SIG_MAXSIG) 1821 return (EINVAL); 1822 1823 ksiginfo_init(&ksi); 1824 ksi.ksi_signo = signum; 1825 ksi.ksi_code = SI_USER; 1826 ksi.ksi_pid = td->td_proc->p_pid; 1827 ksi.ksi_uid = td->td_ucred->cr_ruid; 1828 1829 if (pid > 0) { 1830 /* kill single process */ 1831 if ((p = pfind_any(pid)) == NULL) 1832 return (ESRCH); 1833 AUDIT_ARG_PROCESS(p); 1834 error = p_cansignal(td, p, signum); 1835 if (error == 0 && signum) 1836 pksignal(p, signum, &ksi); 1837 PROC_UNLOCK(p); 1838 return (error); 1839 } 1840 switch (pid) { 1841 case -1: /* broadcast signal */ 1842 return (killpg1(td, signum, 0, 1, &ksi)); 1843 case 0: /* signal own process group */ 1844 return (killpg1(td, signum, 0, 0, &ksi)); 1845 default: /* negative explicit process group */ 1846 return (killpg1(td, signum, -pid, 0, &ksi)); 1847 } 1848 /* NOTREACHED */ 1849 } 1850 1851 int 1852 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1853 { 1854 struct proc *p; 1855 int error; 1856 1857 AUDIT_ARG_SIGNUM(uap->signum); 1858 AUDIT_ARG_FD(uap->fd); 1859 if ((u_int)uap->signum > _SIG_MAXSIG) 1860 return (EINVAL); 1861 1862 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1863 if (error) 1864 return (error); 1865 AUDIT_ARG_PROCESS(p); 1866 error = p_cansignal(td, p, uap->signum); 1867 if (error == 0 && uap->signum) 1868 kern_psignal(p, uap->signum); 1869 PROC_UNLOCK(p); 1870 return (error); 1871 } 1872 1873 #if defined(COMPAT_43) 1874 #ifndef _SYS_SYSPROTO_H_ 1875 struct okillpg_args { 1876 int pgid; 1877 int signum; 1878 }; 1879 #endif 1880 /* ARGSUSED */ 1881 int 1882 okillpg(struct thread *td, struct okillpg_args *uap) 1883 { 1884 ksiginfo_t ksi; 1885 1886 AUDIT_ARG_SIGNUM(uap->signum); 1887 AUDIT_ARG_PID(uap->pgid); 1888 if ((u_int)uap->signum > _SIG_MAXSIG) 1889 return (EINVAL); 1890 1891 ksiginfo_init(&ksi); 1892 ksi.ksi_signo = uap->signum; 1893 ksi.ksi_code = SI_USER; 1894 ksi.ksi_pid = td->td_proc->p_pid; 1895 ksi.ksi_uid = td->td_ucred->cr_ruid; 1896 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1897 } 1898 #endif /* COMPAT_43 */ 1899 1900 #ifndef _SYS_SYSPROTO_H_ 1901 struct sigqueue_args { 1902 pid_t pid; 1903 int signum; 1904 /* union sigval */ void *value; 1905 }; 1906 #endif 1907 int 1908 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1909 { 1910 union sigval sv; 1911 1912 sv.sival_ptr = uap->value; 1913 1914 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1915 } 1916 1917 int 1918 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1919 { 1920 ksiginfo_t ksi; 1921 struct proc *p; 1922 int error; 1923 1924 if ((u_int)signum > _SIG_MAXSIG) 1925 return (EINVAL); 1926 1927 /* 1928 * Specification says sigqueue can only send signal to 1929 * single process. 1930 */ 1931 if (pid <= 0) 1932 return (EINVAL); 1933 1934 if ((p = pfind_any(pid)) == NULL) 1935 return (ESRCH); 1936 error = p_cansignal(td, p, signum); 1937 if (error == 0 && signum != 0) { 1938 ksiginfo_init(&ksi); 1939 ksi.ksi_flags = KSI_SIGQ; 1940 ksi.ksi_signo = signum; 1941 ksi.ksi_code = SI_QUEUE; 1942 ksi.ksi_pid = td->td_proc->p_pid; 1943 ksi.ksi_uid = td->td_ucred->cr_ruid; 1944 ksi.ksi_value = *value; 1945 error = pksignal(p, ksi.ksi_signo, &ksi); 1946 } 1947 PROC_UNLOCK(p); 1948 return (error); 1949 } 1950 1951 /* 1952 * Send a signal to a process group. 1953 */ 1954 void 1955 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1956 { 1957 struct pgrp *pgrp; 1958 1959 if (pgid != 0) { 1960 sx_slock(&proctree_lock); 1961 pgrp = pgfind(pgid); 1962 sx_sunlock(&proctree_lock); 1963 if (pgrp != NULL) { 1964 pgsignal(pgrp, sig, 0, ksi); 1965 PGRP_UNLOCK(pgrp); 1966 } 1967 } 1968 } 1969 1970 /* 1971 * Send a signal to a process group. If checktty is 1, 1972 * limit to members which have a controlling terminal. 1973 */ 1974 void 1975 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1976 { 1977 struct proc *p; 1978 1979 if (pgrp) { 1980 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1981 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1982 PROC_LOCK(p); 1983 if (p->p_state == PRS_NORMAL && 1984 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1985 pksignal(p, sig, ksi); 1986 PROC_UNLOCK(p); 1987 } 1988 } 1989 } 1990 1991 /* 1992 * Recalculate the signal mask and reset the signal disposition after 1993 * usermode frame for delivery is formed. Should be called after 1994 * mach-specific routine, because sysent->sv_sendsig() needs correct 1995 * ps_siginfo and signal mask. 1996 */ 1997 static void 1998 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1999 { 2000 sigset_t mask; 2001 2002 mtx_assert(&ps->ps_mtx, MA_OWNED); 2003 td->td_ru.ru_nsignals++; 2004 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2005 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2006 SIGADDSET(mask, sig); 2007 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2008 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2009 if (SIGISMEMBER(ps->ps_sigreset, sig)) 2010 sigdflt(ps, sig); 2011 } 2012 2013 /* 2014 * Send a signal caused by a trap to the current thread. If it will be 2015 * caught immediately, deliver it with correct code. Otherwise, post it 2016 * normally. 2017 */ 2018 void 2019 trapsignal(struct thread *td, ksiginfo_t *ksi) 2020 { 2021 struct sigacts *ps; 2022 struct proc *p; 2023 sigset_t sigmask; 2024 int code, sig; 2025 2026 p = td->td_proc; 2027 sig = ksi->ksi_signo; 2028 code = ksi->ksi_code; 2029 KASSERT(_SIG_VALID(sig), ("invalid signal")); 2030 2031 sigfastblock_fetch(td); 2032 PROC_LOCK(p); 2033 ps = p->p_sigacts; 2034 mtx_lock(&ps->ps_mtx); 2035 sigmask = td->td_sigmask; 2036 if (td->td_sigblock_val != 0) 2037 SIGSETOR(sigmask, fastblock_mask); 2038 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 2039 !SIGISMEMBER(sigmask, sig)) { 2040 #ifdef KTRACE 2041 if (KTRPOINT(curthread, KTR_PSIG)) 2042 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 2043 &td->td_sigmask, code); 2044 #endif 2045 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 2046 ksi, &td->td_sigmask); 2047 postsig_done(sig, td, ps); 2048 mtx_unlock(&ps->ps_mtx); 2049 } else { 2050 /* 2051 * Avoid a possible infinite loop if the thread 2052 * masking the signal or process is ignoring the 2053 * signal. 2054 */ 2055 if (kern_forcesigexit && (SIGISMEMBER(sigmask, sig) || 2056 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2057 SIGDELSET(td->td_sigmask, sig); 2058 SIGDELSET(ps->ps_sigcatch, sig); 2059 SIGDELSET(ps->ps_sigignore, sig); 2060 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2061 td->td_pflags &= ~TDP_SIGFASTBLOCK; 2062 td->td_sigblock_val = 0; 2063 } 2064 mtx_unlock(&ps->ps_mtx); 2065 p->p_sig = sig; /* XXX to verify code */ 2066 tdsendsignal(p, td, sig, ksi); 2067 } 2068 PROC_UNLOCK(p); 2069 } 2070 2071 static struct thread * 2072 sigtd(struct proc *p, int sig, bool fast_sigblock) 2073 { 2074 struct thread *td, *signal_td; 2075 2076 PROC_LOCK_ASSERT(p, MA_OWNED); 2077 MPASS(!fast_sigblock || p == curproc); 2078 2079 /* 2080 * Check if current thread can handle the signal without 2081 * switching context to another thread. 2082 */ 2083 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig) && 2084 (!fast_sigblock || curthread->td_sigblock_val == 0)) 2085 return (curthread); 2086 signal_td = NULL; 2087 FOREACH_THREAD_IN_PROC(p, td) { 2088 if (!SIGISMEMBER(td->td_sigmask, sig) && (!fast_sigblock || 2089 td != curthread || td->td_sigblock_val == 0)) { 2090 signal_td = td; 2091 break; 2092 } 2093 } 2094 if (signal_td == NULL) 2095 signal_td = FIRST_THREAD_IN_PROC(p); 2096 return (signal_td); 2097 } 2098 2099 /* 2100 * Send the signal to the process. If the signal has an action, the action 2101 * is usually performed by the target process rather than the caller; we add 2102 * the signal to the set of pending signals for the process. 2103 * 2104 * Exceptions: 2105 * o When a stop signal is sent to a sleeping process that takes the 2106 * default action, the process is stopped without awakening it. 2107 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2108 * regardless of the signal action (eg, blocked or ignored). 2109 * 2110 * Other ignored signals are discarded immediately. 2111 * 2112 * NB: This function may be entered from the debugger via the "kill" DDB 2113 * command. There is little that can be done to mitigate the possibly messy 2114 * side effects of this unwise possibility. 2115 */ 2116 void 2117 kern_psignal(struct proc *p, int sig) 2118 { 2119 ksiginfo_t ksi; 2120 2121 ksiginfo_init(&ksi); 2122 ksi.ksi_signo = sig; 2123 ksi.ksi_code = SI_KERNEL; 2124 (void) tdsendsignal(p, NULL, sig, &ksi); 2125 } 2126 2127 int 2128 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2129 { 2130 2131 return (tdsendsignal(p, NULL, sig, ksi)); 2132 } 2133 2134 /* Utility function for finding a thread to send signal event to. */ 2135 int 2136 sigev_findtd(struct proc *p, struct sigevent *sigev, struct thread **ttd) 2137 { 2138 struct thread *td; 2139 2140 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2141 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2142 if (td == NULL) 2143 return (ESRCH); 2144 *ttd = td; 2145 } else { 2146 *ttd = NULL; 2147 PROC_LOCK(p); 2148 } 2149 return (0); 2150 } 2151 2152 void 2153 tdsignal(struct thread *td, int sig) 2154 { 2155 ksiginfo_t ksi; 2156 2157 ksiginfo_init(&ksi); 2158 ksi.ksi_signo = sig; 2159 ksi.ksi_code = SI_KERNEL; 2160 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2161 } 2162 2163 void 2164 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2165 { 2166 2167 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2168 } 2169 2170 static int 2171 sig_sleepq_abort(struct thread *td, int intrval) 2172 { 2173 THREAD_LOCK_ASSERT(td, MA_OWNED); 2174 2175 if (intrval == 0 && (td->td_flags & TDF_SIGWAIT) == 0) { 2176 thread_unlock(td); 2177 return (0); 2178 } 2179 return (sleepq_abort(td, intrval)); 2180 } 2181 2182 int 2183 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2184 { 2185 sig_t action; 2186 sigqueue_t *sigqueue; 2187 int prop; 2188 struct sigacts *ps; 2189 int intrval; 2190 int ret = 0; 2191 int wakeup_swapper; 2192 2193 MPASS(td == NULL || p == td->td_proc); 2194 PROC_LOCK_ASSERT(p, MA_OWNED); 2195 2196 if (!_SIG_VALID(sig)) 2197 panic("%s(): invalid signal %d", __func__, sig); 2198 2199 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2200 2201 /* 2202 * IEEE Std 1003.1-2001: return success when killing a zombie. 2203 */ 2204 if (p->p_state == PRS_ZOMBIE) { 2205 if (ksi && (ksi->ksi_flags & KSI_INS)) 2206 ksiginfo_tryfree(ksi); 2207 return (ret); 2208 } 2209 2210 ps = p->p_sigacts; 2211 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2212 prop = sigprop(sig); 2213 2214 if (td == NULL) { 2215 td = sigtd(p, sig, false); 2216 sigqueue = &p->p_sigqueue; 2217 } else 2218 sigqueue = &td->td_sigqueue; 2219 2220 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2221 2222 /* 2223 * If the signal is being ignored, then we forget about it 2224 * immediately, except when the target process executes 2225 * sigwait(). (Note: we don't set SIGCONT in ps_sigignore, 2226 * and if it is set to SIG_IGN, action will be SIG_DFL here.) 2227 */ 2228 mtx_lock(&ps->ps_mtx); 2229 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2230 if (kern_sig_discard_ign && 2231 (p->p_sysent->sv_flags & SV_SIG_DISCIGN) == 0) { 2232 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2233 2234 mtx_unlock(&ps->ps_mtx); 2235 if (ksi && (ksi->ksi_flags & KSI_INS)) 2236 ksiginfo_tryfree(ksi); 2237 return (ret); 2238 } else { 2239 action = SIG_CATCH; 2240 intrval = 0; 2241 } 2242 } else { 2243 if (SIGISMEMBER(td->td_sigmask, sig)) 2244 action = SIG_HOLD; 2245 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2246 action = SIG_CATCH; 2247 else 2248 action = SIG_DFL; 2249 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2250 intrval = EINTR; 2251 else 2252 intrval = ERESTART; 2253 } 2254 mtx_unlock(&ps->ps_mtx); 2255 2256 if (prop & SIGPROP_CONT) 2257 sigqueue_delete_stopmask_proc(p); 2258 else if (prop & SIGPROP_STOP) { 2259 /* 2260 * If sending a tty stop signal to a member of an orphaned 2261 * process group, discard the signal here if the action 2262 * is default; don't stop the process below if sleeping, 2263 * and don't clear any pending SIGCONT. 2264 */ 2265 if ((prop & SIGPROP_TTYSTOP) != 0 && 2266 (p->p_pgrp->pg_flags & PGRP_ORPHANED) != 0 && 2267 action == SIG_DFL) { 2268 if (ksi && (ksi->ksi_flags & KSI_INS)) 2269 ksiginfo_tryfree(ksi); 2270 return (ret); 2271 } 2272 sigqueue_delete_proc(p, SIGCONT); 2273 if (p->p_flag & P_CONTINUED) { 2274 p->p_flag &= ~P_CONTINUED; 2275 PROC_LOCK(p->p_pptr); 2276 sigqueue_take(p->p_ksi); 2277 PROC_UNLOCK(p->p_pptr); 2278 } 2279 } 2280 2281 ret = sigqueue_add(sigqueue, sig, ksi); 2282 if (ret != 0) 2283 return (ret); 2284 signotify(td); 2285 /* 2286 * Defer further processing for signals which are held, 2287 * except that stopped processes must be continued by SIGCONT. 2288 */ 2289 if (action == SIG_HOLD && 2290 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2291 return (ret); 2292 2293 wakeup_swapper = 0; 2294 2295 /* 2296 * Some signals have a process-wide effect and a per-thread 2297 * component. Most processing occurs when the process next 2298 * tries to cross the user boundary, however there are some 2299 * times when processing needs to be done immediately, such as 2300 * waking up threads so that they can cross the user boundary. 2301 * We try to do the per-process part here. 2302 */ 2303 if (P_SHOULDSTOP(p)) { 2304 KASSERT(!(p->p_flag & P_WEXIT), 2305 ("signal to stopped but exiting process")); 2306 if (sig == SIGKILL) { 2307 /* 2308 * If traced process is already stopped, 2309 * then no further action is necessary. 2310 */ 2311 if (p->p_flag & P_TRACED) 2312 goto out; 2313 /* 2314 * SIGKILL sets process running. 2315 * It will die elsewhere. 2316 * All threads must be restarted. 2317 */ 2318 p->p_flag &= ~P_STOPPED_SIG; 2319 goto runfast; 2320 } 2321 2322 if (prop & SIGPROP_CONT) { 2323 /* 2324 * If traced process is already stopped, 2325 * then no further action is necessary. 2326 */ 2327 if (p->p_flag & P_TRACED) 2328 goto out; 2329 /* 2330 * If SIGCONT is default (or ignored), we continue the 2331 * process but don't leave the signal in sigqueue as 2332 * it has no further action. If SIGCONT is held, we 2333 * continue the process and leave the signal in 2334 * sigqueue. If the process catches SIGCONT, let it 2335 * handle the signal itself. If it isn't waiting on 2336 * an event, it goes back to run state. 2337 * Otherwise, process goes back to sleep state. 2338 */ 2339 p->p_flag &= ~P_STOPPED_SIG; 2340 PROC_SLOCK(p); 2341 if (p->p_numthreads == p->p_suspcount) { 2342 PROC_SUNLOCK(p); 2343 p->p_flag |= P_CONTINUED; 2344 p->p_xsig = SIGCONT; 2345 PROC_LOCK(p->p_pptr); 2346 childproc_continued(p); 2347 PROC_UNLOCK(p->p_pptr); 2348 PROC_SLOCK(p); 2349 } 2350 if (action == SIG_DFL) { 2351 thread_unsuspend(p); 2352 PROC_SUNLOCK(p); 2353 sigqueue_delete(sigqueue, sig); 2354 goto out_cont; 2355 } 2356 if (action == SIG_CATCH) { 2357 /* 2358 * The process wants to catch it so it needs 2359 * to run at least one thread, but which one? 2360 */ 2361 PROC_SUNLOCK(p); 2362 goto runfast; 2363 } 2364 /* 2365 * The signal is not ignored or caught. 2366 */ 2367 thread_unsuspend(p); 2368 PROC_SUNLOCK(p); 2369 goto out_cont; 2370 } 2371 2372 if (prop & SIGPROP_STOP) { 2373 /* 2374 * If traced process is already stopped, 2375 * then no further action is necessary. 2376 */ 2377 if (p->p_flag & P_TRACED) 2378 goto out; 2379 /* 2380 * Already stopped, don't need to stop again 2381 * (If we did the shell could get confused). 2382 * Just make sure the signal STOP bit set. 2383 */ 2384 p->p_flag |= P_STOPPED_SIG; 2385 sigqueue_delete(sigqueue, sig); 2386 goto out; 2387 } 2388 2389 /* 2390 * All other kinds of signals: 2391 * If a thread is sleeping interruptibly, simulate a 2392 * wakeup so that when it is continued it will be made 2393 * runnable and can look at the signal. However, don't make 2394 * the PROCESS runnable, leave it stopped. 2395 * It may run a bit until it hits a thread_suspend_check(). 2396 */ 2397 PROC_SLOCK(p); 2398 thread_lock(td); 2399 if (TD_CAN_ABORT(td)) 2400 wakeup_swapper = sig_sleepq_abort(td, intrval); 2401 else 2402 thread_unlock(td); 2403 PROC_SUNLOCK(p); 2404 goto out; 2405 /* 2406 * Mutexes are short lived. Threads waiting on them will 2407 * hit thread_suspend_check() soon. 2408 */ 2409 } else if (p->p_state == PRS_NORMAL) { 2410 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2411 tdsigwakeup(td, sig, action, intrval); 2412 goto out; 2413 } 2414 2415 MPASS(action == SIG_DFL); 2416 2417 if (prop & SIGPROP_STOP) { 2418 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2419 goto out; 2420 p->p_flag |= P_STOPPED_SIG; 2421 p->p_xsig = sig; 2422 PROC_SLOCK(p); 2423 wakeup_swapper = sig_suspend_threads(td, p, 1); 2424 if (p->p_numthreads == p->p_suspcount) { 2425 /* 2426 * only thread sending signal to another 2427 * process can reach here, if thread is sending 2428 * signal to its process, because thread does 2429 * not suspend itself here, p_numthreads 2430 * should never be equal to p_suspcount. 2431 */ 2432 thread_stopped(p); 2433 PROC_SUNLOCK(p); 2434 sigqueue_delete_proc(p, p->p_xsig); 2435 } else 2436 PROC_SUNLOCK(p); 2437 goto out; 2438 } 2439 } else { 2440 /* Not in "NORMAL" state. discard the signal. */ 2441 sigqueue_delete(sigqueue, sig); 2442 goto out; 2443 } 2444 2445 /* 2446 * The process is not stopped so we need to apply the signal to all the 2447 * running threads. 2448 */ 2449 runfast: 2450 tdsigwakeup(td, sig, action, intrval); 2451 PROC_SLOCK(p); 2452 thread_unsuspend(p); 2453 PROC_SUNLOCK(p); 2454 out_cont: 2455 itimer_proc_continue(p); 2456 kqtimer_proc_continue(p); 2457 out: 2458 /* If we jump here, proc slock should not be owned. */ 2459 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2460 if (wakeup_swapper) 2461 kick_proc0(); 2462 2463 return (ret); 2464 } 2465 2466 /* 2467 * The force of a signal has been directed against a single 2468 * thread. We need to see what we can do about knocking it 2469 * out of any sleep it may be in etc. 2470 */ 2471 static void 2472 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2473 { 2474 struct proc *p = td->td_proc; 2475 int prop, wakeup_swapper; 2476 2477 PROC_LOCK_ASSERT(p, MA_OWNED); 2478 prop = sigprop(sig); 2479 2480 PROC_SLOCK(p); 2481 thread_lock(td); 2482 /* 2483 * Bring the priority of a thread up if we want it to get 2484 * killed in this lifetime. Be careful to avoid bumping the 2485 * priority of the idle thread, since we still allow to signal 2486 * kernel processes. 2487 */ 2488 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2489 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2490 sched_prio(td, PUSER); 2491 if (TD_ON_SLEEPQ(td)) { 2492 /* 2493 * If thread is sleeping uninterruptibly 2494 * we can't interrupt the sleep... the signal will 2495 * be noticed when the process returns through 2496 * trap() or syscall(). 2497 */ 2498 if ((td->td_flags & TDF_SINTR) == 0) 2499 goto out; 2500 /* 2501 * If SIGCONT is default (or ignored) and process is 2502 * asleep, we are finished; the process should not 2503 * be awakened. 2504 */ 2505 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2506 thread_unlock(td); 2507 PROC_SUNLOCK(p); 2508 sigqueue_delete(&p->p_sigqueue, sig); 2509 /* 2510 * It may be on either list in this state. 2511 * Remove from both for now. 2512 */ 2513 sigqueue_delete(&td->td_sigqueue, sig); 2514 return; 2515 } 2516 2517 /* 2518 * Don't awaken a sleeping thread for SIGSTOP if the 2519 * STOP signal is deferred. 2520 */ 2521 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2522 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2523 goto out; 2524 2525 /* 2526 * Give low priority threads a better chance to run. 2527 */ 2528 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2529 sched_prio(td, PUSER); 2530 2531 wakeup_swapper = sig_sleepq_abort(td, intrval); 2532 PROC_SUNLOCK(p); 2533 if (wakeup_swapper) 2534 kick_proc0(); 2535 return; 2536 } 2537 2538 /* 2539 * Other states do nothing with the signal immediately, 2540 * other than kicking ourselves if we are running. 2541 * It will either never be noticed, or noticed very soon. 2542 */ 2543 #ifdef SMP 2544 if (TD_IS_RUNNING(td) && td != curthread) 2545 forward_signal(td); 2546 #endif 2547 2548 out: 2549 PROC_SUNLOCK(p); 2550 thread_unlock(td); 2551 } 2552 2553 static void 2554 ptrace_coredump(struct thread *td) 2555 { 2556 struct proc *p; 2557 struct thr_coredump_req *tcq; 2558 void *rl_cookie; 2559 2560 MPASS(td == curthread); 2561 p = td->td_proc; 2562 PROC_LOCK_ASSERT(p, MA_OWNED); 2563 if ((td->td_dbgflags & TDB_COREDUMPRQ) == 0) 2564 return; 2565 KASSERT((p->p_flag & P_STOPPED_TRACE) != 0, ("not stopped")); 2566 2567 tcq = td->td_coredump; 2568 KASSERT(tcq != NULL, ("td_coredump is NULL")); 2569 2570 if (p->p_sysent->sv_coredump == NULL) { 2571 tcq->tc_error = ENOSYS; 2572 goto wake; 2573 } 2574 2575 PROC_UNLOCK(p); 2576 rl_cookie = vn_rangelock_wlock(tcq->tc_vp, 0, OFF_MAX); 2577 2578 tcq->tc_error = p->p_sysent->sv_coredump(td, tcq->tc_vp, 2579 tcq->tc_limit, tcq->tc_flags); 2580 2581 vn_rangelock_unlock(tcq->tc_vp, rl_cookie); 2582 PROC_LOCK(p); 2583 wake: 2584 td->td_dbgflags &= ~TDB_COREDUMPRQ; 2585 td->td_coredump = NULL; 2586 wakeup(p); 2587 } 2588 2589 static int 2590 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2591 { 2592 struct thread *td2; 2593 int wakeup_swapper; 2594 2595 PROC_LOCK_ASSERT(p, MA_OWNED); 2596 PROC_SLOCK_ASSERT(p, MA_OWNED); 2597 MPASS(sending || td == curthread); 2598 2599 wakeup_swapper = 0; 2600 FOREACH_THREAD_IN_PROC(p, td2) { 2601 thread_lock(td2); 2602 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2603 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2604 (td2->td_flags & TDF_SINTR)) { 2605 if (td2->td_flags & TDF_SBDRY) { 2606 /* 2607 * Once a thread is asleep with 2608 * TDF_SBDRY and without TDF_SERESTART 2609 * or TDF_SEINTR set, it should never 2610 * become suspended due to this check. 2611 */ 2612 KASSERT(!TD_IS_SUSPENDED(td2), 2613 ("thread with deferred stops suspended")); 2614 if (TD_SBDRY_INTR(td2)) { 2615 wakeup_swapper |= sleepq_abort(td2, 2616 TD_SBDRY_ERRNO(td2)); 2617 continue; 2618 } 2619 } else if (!TD_IS_SUSPENDED(td2)) 2620 thread_suspend_one(td2); 2621 } else if (!TD_IS_SUSPENDED(td2)) { 2622 if (sending || td != td2) 2623 td2->td_flags |= TDF_ASTPENDING; 2624 #ifdef SMP 2625 if (TD_IS_RUNNING(td2) && td2 != td) 2626 forward_signal(td2); 2627 #endif 2628 } 2629 thread_unlock(td2); 2630 } 2631 return (wakeup_swapper); 2632 } 2633 2634 /* 2635 * Stop the process for an event deemed interesting to the debugger. If si is 2636 * non-NULL, this is a signal exchange; the new signal requested by the 2637 * debugger will be returned for handling. If si is NULL, this is some other 2638 * type of interesting event. The debugger may request a signal be delivered in 2639 * that case as well, however it will be deferred until it can be handled. 2640 */ 2641 int 2642 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2643 { 2644 struct proc *p = td->td_proc; 2645 struct thread *td2; 2646 ksiginfo_t ksi; 2647 2648 PROC_LOCK_ASSERT(p, MA_OWNED); 2649 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2650 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2651 &p->p_mtx.lock_object, "Stopping for traced signal"); 2652 2653 td->td_xsig = sig; 2654 2655 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2656 td->td_dbgflags |= TDB_XSIG; 2657 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2658 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2659 PROC_SLOCK(p); 2660 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2661 if (P_KILLED(p)) { 2662 /* 2663 * Ensure that, if we've been PT_KILLed, the 2664 * exit status reflects that. Another thread 2665 * may also be in ptracestop(), having just 2666 * received the SIGKILL, but this thread was 2667 * unsuspended first. 2668 */ 2669 td->td_dbgflags &= ~TDB_XSIG; 2670 td->td_xsig = SIGKILL; 2671 p->p_ptevents = 0; 2672 break; 2673 } 2674 if (p->p_flag & P_SINGLE_EXIT && 2675 !(td->td_dbgflags & TDB_EXIT)) { 2676 /* 2677 * Ignore ptrace stops except for thread exit 2678 * events when the process exits. 2679 */ 2680 td->td_dbgflags &= ~TDB_XSIG; 2681 PROC_SUNLOCK(p); 2682 return (0); 2683 } 2684 2685 /* 2686 * Make wait(2) work. Ensure that right after the 2687 * attach, the thread which was decided to become the 2688 * leader of attach gets reported to the waiter. 2689 * Otherwise, just avoid overwriting another thread's 2690 * assignment to p_xthread. If another thread has 2691 * already set p_xthread, the current thread will get 2692 * a chance to report itself upon the next iteration. 2693 */ 2694 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2695 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2696 p->p_xthread == NULL)) { 2697 p->p_xsig = sig; 2698 p->p_xthread = td; 2699 2700 /* 2701 * If we are on sleepqueue already, 2702 * let sleepqueue code decide if it 2703 * needs to go sleep after attach. 2704 */ 2705 if (td->td_wchan == NULL) 2706 td->td_dbgflags &= ~TDB_FSTP; 2707 2708 p->p_flag2 &= ~P2_PTRACE_FSTP; 2709 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2710 sig_suspend_threads(td, p, 0); 2711 } 2712 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2713 td->td_dbgflags &= ~TDB_STOPATFORK; 2714 } 2715 stopme: 2716 td->td_dbgflags |= TDB_SSWITCH; 2717 thread_suspend_switch(td, p); 2718 td->td_dbgflags &= ~TDB_SSWITCH; 2719 if ((td->td_dbgflags & TDB_COREDUMPRQ) != 0) { 2720 PROC_SUNLOCK(p); 2721 ptrace_coredump(td); 2722 PROC_SLOCK(p); 2723 goto stopme; 2724 } 2725 if (p->p_xthread == td) 2726 p->p_xthread = NULL; 2727 if (!(p->p_flag & P_TRACED)) 2728 break; 2729 if (td->td_dbgflags & TDB_SUSPEND) { 2730 if (p->p_flag & P_SINGLE_EXIT) 2731 break; 2732 goto stopme; 2733 } 2734 } 2735 PROC_SUNLOCK(p); 2736 } 2737 2738 if (si != NULL && sig == td->td_xsig) { 2739 /* Parent wants us to take the original signal unchanged. */ 2740 si->ksi_flags |= KSI_HEAD; 2741 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2742 si->ksi_signo = 0; 2743 } else if (td->td_xsig != 0) { 2744 /* 2745 * If parent wants us to take a new signal, then it will leave 2746 * it in td->td_xsig; otherwise we just look for signals again. 2747 */ 2748 ksiginfo_init(&ksi); 2749 ksi.ksi_signo = td->td_xsig; 2750 ksi.ksi_flags |= KSI_PTRACE; 2751 td2 = sigtd(p, td->td_xsig, false); 2752 tdsendsignal(p, td2, td->td_xsig, &ksi); 2753 if (td != td2) 2754 return (0); 2755 } 2756 2757 return (td->td_xsig); 2758 } 2759 2760 static void 2761 reschedule_signals(struct proc *p, sigset_t block, int flags) 2762 { 2763 struct sigacts *ps; 2764 struct thread *td; 2765 int sig; 2766 bool fastblk, pslocked; 2767 2768 PROC_LOCK_ASSERT(p, MA_OWNED); 2769 ps = p->p_sigacts; 2770 pslocked = (flags & SIGPROCMASK_PS_LOCKED) != 0; 2771 mtx_assert(&ps->ps_mtx, pslocked ? MA_OWNED : MA_NOTOWNED); 2772 if (SIGISEMPTY(p->p_siglist)) 2773 return; 2774 SIGSETAND(block, p->p_siglist); 2775 fastblk = (flags & SIGPROCMASK_FASTBLK) != 0; 2776 SIG_FOREACH(sig, &block) { 2777 td = sigtd(p, sig, fastblk); 2778 2779 /* 2780 * If sigtd() selected us despite sigfastblock is 2781 * blocking, do not activate AST or wake us, to avoid 2782 * loop in AST handler. 2783 */ 2784 if (fastblk && td == curthread) 2785 continue; 2786 2787 signotify(td); 2788 if (!pslocked) 2789 mtx_lock(&ps->ps_mtx); 2790 if (p->p_flag & P_TRACED || 2791 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2792 !SIGISMEMBER(td->td_sigmask, sig))) { 2793 tdsigwakeup(td, sig, SIG_CATCH, 2794 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2795 ERESTART)); 2796 } 2797 if (!pslocked) 2798 mtx_unlock(&ps->ps_mtx); 2799 } 2800 } 2801 2802 void 2803 tdsigcleanup(struct thread *td) 2804 { 2805 struct proc *p; 2806 sigset_t unblocked; 2807 2808 p = td->td_proc; 2809 PROC_LOCK_ASSERT(p, MA_OWNED); 2810 2811 sigqueue_flush(&td->td_sigqueue); 2812 if (p->p_numthreads == 1) 2813 return; 2814 2815 /* 2816 * Since we cannot handle signals, notify signal post code 2817 * about this by filling the sigmask. 2818 * 2819 * Also, if needed, wake up thread(s) that do not block the 2820 * same signals as the exiting thread, since the thread might 2821 * have been selected for delivery and woken up. 2822 */ 2823 SIGFILLSET(unblocked); 2824 SIGSETNAND(unblocked, td->td_sigmask); 2825 SIGFILLSET(td->td_sigmask); 2826 reschedule_signals(p, unblocked, 0); 2827 2828 } 2829 2830 static int 2831 sigdeferstop_curr_flags(int cflags) 2832 { 2833 2834 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2835 (cflags & TDF_SBDRY) != 0); 2836 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2837 } 2838 2839 /* 2840 * Defer the delivery of SIGSTOP for the current thread, according to 2841 * the requested mode. Returns previous flags, which must be restored 2842 * by sigallowstop(). 2843 * 2844 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2845 * cleared by the current thread, which allow the lock-less read-only 2846 * accesses below. 2847 */ 2848 int 2849 sigdeferstop_impl(int mode) 2850 { 2851 struct thread *td; 2852 int cflags, nflags; 2853 2854 td = curthread; 2855 cflags = sigdeferstop_curr_flags(td->td_flags); 2856 switch (mode) { 2857 case SIGDEFERSTOP_NOP: 2858 nflags = cflags; 2859 break; 2860 case SIGDEFERSTOP_OFF: 2861 nflags = 0; 2862 break; 2863 case SIGDEFERSTOP_SILENT: 2864 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2865 break; 2866 case SIGDEFERSTOP_EINTR: 2867 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2868 break; 2869 case SIGDEFERSTOP_ERESTART: 2870 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2871 break; 2872 default: 2873 panic("sigdeferstop: invalid mode %x", mode); 2874 break; 2875 } 2876 if (cflags == nflags) 2877 return (SIGDEFERSTOP_VAL_NCHG); 2878 thread_lock(td); 2879 td->td_flags = (td->td_flags & ~cflags) | nflags; 2880 thread_unlock(td); 2881 return (cflags); 2882 } 2883 2884 /* 2885 * Restores the STOP handling mode, typically permitting the delivery 2886 * of SIGSTOP for the current thread. This does not immediately 2887 * suspend if a stop was posted. Instead, the thread will suspend 2888 * either via ast() or a subsequent interruptible sleep. 2889 */ 2890 void 2891 sigallowstop_impl(int prev) 2892 { 2893 struct thread *td; 2894 int cflags; 2895 2896 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2897 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2898 ("sigallowstop: incorrect previous mode %x", prev)); 2899 td = curthread; 2900 cflags = sigdeferstop_curr_flags(td->td_flags); 2901 if (cflags != prev) { 2902 thread_lock(td); 2903 td->td_flags = (td->td_flags & ~cflags) | prev; 2904 thread_unlock(td); 2905 } 2906 } 2907 2908 enum sigstatus { 2909 SIGSTATUS_HANDLE, 2910 SIGSTATUS_HANDLED, 2911 SIGSTATUS_IGNORE, 2912 SIGSTATUS_SBDRY_STOP, 2913 }; 2914 2915 /* 2916 * The thread has signal "sig" pending. Figure out what to do with it: 2917 * 2918 * _HANDLE -> the caller should handle the signal 2919 * _HANDLED -> handled internally, reload pending signal set 2920 * _IGNORE -> ignored, remove from the set of pending signals and try the 2921 * next pending signal 2922 * _SBDRY_STOP -> the signal should stop the thread but this is not 2923 * permitted in the current context 2924 */ 2925 static enum sigstatus 2926 sigprocess(struct thread *td, int sig) 2927 { 2928 struct proc *p; 2929 struct sigacts *ps; 2930 struct sigqueue *queue; 2931 ksiginfo_t ksi; 2932 int prop; 2933 2934 KASSERT(_SIG_VALID(sig), ("%s: invalid signal %d", __func__, sig)); 2935 2936 p = td->td_proc; 2937 ps = p->p_sigacts; 2938 mtx_assert(&ps->ps_mtx, MA_OWNED); 2939 PROC_LOCK_ASSERT(p, MA_OWNED); 2940 2941 /* 2942 * We should allow pending but ignored signals below 2943 * only if there is sigwait() active, or P_TRACED was 2944 * on when they were posted. 2945 */ 2946 if (SIGISMEMBER(ps->ps_sigignore, sig) && 2947 (p->p_flag & P_TRACED) == 0 && 2948 (td->td_flags & TDF_SIGWAIT) == 0) { 2949 return (SIGSTATUS_IGNORE); 2950 } 2951 2952 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2953 /* 2954 * If traced, always stop. 2955 * Remove old signal from queue before the stop. 2956 * XXX shrug off debugger, it causes siginfo to 2957 * be thrown away. 2958 */ 2959 queue = &td->td_sigqueue; 2960 ksiginfo_init(&ksi); 2961 if (sigqueue_get(queue, sig, &ksi) == 0) { 2962 queue = &p->p_sigqueue; 2963 sigqueue_get(queue, sig, &ksi); 2964 } 2965 td->td_si = ksi.ksi_info; 2966 2967 mtx_unlock(&ps->ps_mtx); 2968 sig = ptracestop(td, sig, &ksi); 2969 mtx_lock(&ps->ps_mtx); 2970 2971 td->td_si.si_signo = 0; 2972 2973 /* 2974 * Keep looking if the debugger discarded or 2975 * replaced the signal. 2976 */ 2977 if (sig == 0) 2978 return (SIGSTATUS_HANDLED); 2979 2980 /* 2981 * If the signal became masked, re-queue it. 2982 */ 2983 if (SIGISMEMBER(td->td_sigmask, sig)) { 2984 ksi.ksi_flags |= KSI_HEAD; 2985 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2986 return (SIGSTATUS_HANDLED); 2987 } 2988 2989 /* 2990 * If the traced bit got turned off, requeue the signal and 2991 * reload the set of pending signals. This ensures that p_sig* 2992 * and p_sigact are consistent. 2993 */ 2994 if ((p->p_flag & P_TRACED) == 0) { 2995 ksi.ksi_flags |= KSI_HEAD; 2996 sigqueue_add(queue, sig, &ksi); 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 p->p_acflag |= AXSIG; 3420 /* 3421 * We must be single-threading to generate a core dump. This 3422 * ensures that the registers in the core file are up-to-date. 3423 * Also, the ELF dump handler assumes that the thread list doesn't 3424 * change out from under it. 3425 * 3426 * XXX If another thread attempts to single-thread before us 3427 * (e.g. via fork()), we won't get a dump at all. 3428 */ 3429 if ((sigprop(sig) & SIGPROP_CORE) && 3430 thread_single(p, SINGLE_NO_EXIT) == 0) { 3431 p->p_sig = sig; 3432 /* 3433 * Log signals which would cause core dumps 3434 * (Log as LOG_INFO to appease those who don't want 3435 * these messages.) 3436 * XXX : Todo, as well as euid, write out ruid too 3437 * Note that coredump() drops proc lock. 3438 */ 3439 if (coredump(td) == 0) 3440 sig |= WCOREFLAG; 3441 if (kern_logsigexit) 3442 log(LOG_INFO, 3443 "pid %d (%s), jid %d, uid %d: exited on " 3444 "signal %d%s\n", p->p_pid, p->p_comm, 3445 p->p_ucred->cr_prison->pr_id, 3446 td->td_ucred->cr_uid, 3447 sig &~ WCOREFLAG, 3448 sig & WCOREFLAG ? " (core dumped)" : ""); 3449 } else 3450 PROC_UNLOCK(p); 3451 exit1(td, 0, sig); 3452 /* NOTREACHED */ 3453 } 3454 3455 /* 3456 * Send queued SIGCHLD to parent when child process's state 3457 * is changed. 3458 */ 3459 static void 3460 sigparent(struct proc *p, int reason, int status) 3461 { 3462 PROC_LOCK_ASSERT(p, MA_OWNED); 3463 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3464 3465 if (p->p_ksi != NULL) { 3466 p->p_ksi->ksi_signo = SIGCHLD; 3467 p->p_ksi->ksi_code = reason; 3468 p->p_ksi->ksi_status = status; 3469 p->p_ksi->ksi_pid = p->p_pid; 3470 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3471 if (KSI_ONQ(p->p_ksi)) 3472 return; 3473 } 3474 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3475 } 3476 3477 static void 3478 childproc_jobstate(struct proc *p, int reason, int sig) 3479 { 3480 struct sigacts *ps; 3481 3482 PROC_LOCK_ASSERT(p, MA_OWNED); 3483 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3484 3485 /* 3486 * Wake up parent sleeping in kern_wait(), also send 3487 * SIGCHLD to parent, but SIGCHLD does not guarantee 3488 * that parent will awake, because parent may masked 3489 * the signal. 3490 */ 3491 p->p_pptr->p_flag |= P_STATCHILD; 3492 wakeup(p->p_pptr); 3493 3494 ps = p->p_pptr->p_sigacts; 3495 mtx_lock(&ps->ps_mtx); 3496 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3497 mtx_unlock(&ps->ps_mtx); 3498 sigparent(p, reason, sig); 3499 } else 3500 mtx_unlock(&ps->ps_mtx); 3501 } 3502 3503 void 3504 childproc_stopped(struct proc *p, int reason) 3505 { 3506 3507 childproc_jobstate(p, reason, p->p_xsig); 3508 } 3509 3510 void 3511 childproc_continued(struct proc *p) 3512 { 3513 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3514 } 3515 3516 void 3517 childproc_exited(struct proc *p) 3518 { 3519 int reason, status; 3520 3521 if (WCOREDUMP(p->p_xsig)) { 3522 reason = CLD_DUMPED; 3523 status = WTERMSIG(p->p_xsig); 3524 } else if (WIFSIGNALED(p->p_xsig)) { 3525 reason = CLD_KILLED; 3526 status = WTERMSIG(p->p_xsig); 3527 } else { 3528 reason = CLD_EXITED; 3529 status = p->p_xexit; 3530 } 3531 /* 3532 * XXX avoid calling wakeup(p->p_pptr), the work is 3533 * done in exit1(). 3534 */ 3535 sigparent(p, reason, status); 3536 } 3537 3538 #define MAX_NUM_CORE_FILES 100000 3539 #ifndef NUM_CORE_FILES 3540 #define NUM_CORE_FILES 5 3541 #endif 3542 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3543 static int num_cores = NUM_CORE_FILES; 3544 3545 static int 3546 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3547 { 3548 int error; 3549 int new_val; 3550 3551 new_val = num_cores; 3552 error = sysctl_handle_int(oidp, &new_val, 0, req); 3553 if (error != 0 || req->newptr == NULL) 3554 return (error); 3555 if (new_val > MAX_NUM_CORE_FILES) 3556 new_val = MAX_NUM_CORE_FILES; 3557 if (new_val < 0) 3558 new_val = 0; 3559 num_cores = new_val; 3560 return (0); 3561 } 3562 SYSCTL_PROC(_debug, OID_AUTO, ncores, 3563 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, sizeof(int), 3564 sysctl_debug_num_cores_check, "I", 3565 "Maximum number of generated process corefiles while using index format"); 3566 3567 #define GZIP_SUFFIX ".gz" 3568 #define ZSTD_SUFFIX ".zst" 3569 3570 int compress_user_cores = 0; 3571 3572 static int 3573 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3574 { 3575 int error, val; 3576 3577 val = compress_user_cores; 3578 error = sysctl_handle_int(oidp, &val, 0, req); 3579 if (error != 0 || req->newptr == NULL) 3580 return (error); 3581 if (val != 0 && !compressor_avail(val)) 3582 return (EINVAL); 3583 compress_user_cores = val; 3584 return (error); 3585 } 3586 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, 3587 CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3588 sysctl_compress_user_cores, "I", 3589 "Enable compression of user corefiles (" 3590 __XSTRING(COMPRESS_GZIP) " = gzip, " 3591 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3592 3593 int compress_user_cores_level = 6; 3594 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3595 &compress_user_cores_level, 0, 3596 "Corefile compression level"); 3597 3598 /* 3599 * Protect the access to corefilename[] by allproc_lock. 3600 */ 3601 #define corefilename_lock allproc_lock 3602 3603 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3604 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3605 3606 static int 3607 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3608 { 3609 int error; 3610 3611 sx_xlock(&corefilename_lock); 3612 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3613 req); 3614 sx_xunlock(&corefilename_lock); 3615 3616 return (error); 3617 } 3618 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3619 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3620 "Process corefile name format string"); 3621 3622 static void 3623 vnode_close_locked(struct thread *td, struct vnode *vp) 3624 { 3625 3626 VOP_UNLOCK(vp); 3627 vn_close(vp, FWRITE, td->td_ucred, td); 3628 } 3629 3630 /* 3631 * If the core format has a %I in it, then we need to check 3632 * for existing corefiles before defining a name. 3633 * To do this we iterate over 0..ncores to find a 3634 * non-existing core file name to use. If all core files are 3635 * already used we choose the oldest one. 3636 */ 3637 static int 3638 corefile_open_last(struct thread *td, char *name, int indexpos, 3639 int indexlen, int ncores, struct vnode **vpp) 3640 { 3641 struct vnode *oldvp, *nextvp, *vp; 3642 struct vattr vattr; 3643 struct nameidata nd; 3644 int error, i, flags, oflags, cmode; 3645 char ch; 3646 struct timespec lasttime; 3647 3648 nextvp = oldvp = NULL; 3649 cmode = S_IRUSR | S_IWUSR; 3650 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3651 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3652 3653 for (i = 0; i < ncores; i++) { 3654 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3655 3656 ch = name[indexpos + indexlen]; 3657 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3658 i); 3659 name[indexpos + indexlen] = ch; 3660 3661 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name); 3662 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3663 NULL); 3664 if (error != 0) 3665 break; 3666 3667 vp = nd.ni_vp; 3668 NDFREE(&nd, NDF_ONLY_PNBUF); 3669 if ((flags & O_CREAT) == O_CREAT) { 3670 nextvp = vp; 3671 break; 3672 } 3673 3674 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3675 if (error != 0) { 3676 vnode_close_locked(td, vp); 3677 break; 3678 } 3679 3680 if (oldvp == NULL || 3681 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3682 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3683 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3684 if (oldvp != NULL) 3685 vn_close(oldvp, FWRITE, td->td_ucred, td); 3686 oldvp = vp; 3687 VOP_UNLOCK(oldvp); 3688 lasttime = vattr.va_mtime; 3689 } else { 3690 vnode_close_locked(td, vp); 3691 } 3692 } 3693 3694 if (oldvp != NULL) { 3695 if (nextvp == NULL) { 3696 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3697 error = EFAULT; 3698 vn_close(oldvp, FWRITE, td->td_ucred, td); 3699 } else { 3700 nextvp = oldvp; 3701 error = vn_lock(nextvp, LK_EXCLUSIVE); 3702 if (error != 0) { 3703 vn_close(nextvp, FWRITE, td->td_ucred, 3704 td); 3705 nextvp = NULL; 3706 } 3707 } 3708 } else { 3709 vn_close(oldvp, FWRITE, td->td_ucred, td); 3710 } 3711 } 3712 if (error != 0) { 3713 if (nextvp != NULL) 3714 vnode_close_locked(td, oldvp); 3715 } else { 3716 *vpp = nextvp; 3717 } 3718 3719 return (error); 3720 } 3721 3722 /* 3723 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3724 * Expand the name described in corefilename, using name, uid, and pid 3725 * and open/create core file. 3726 * corefilename is a printf-like string, with three format specifiers: 3727 * %N name of process ("name") 3728 * %P process id (pid) 3729 * %U user id (uid) 3730 * For example, "%N.core" is the default; they can be disabled completely 3731 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3732 * This is controlled by the sysctl variable kern.corefile (see above). 3733 */ 3734 static int 3735 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3736 int compress, int signum, struct vnode **vpp, char **namep) 3737 { 3738 struct sbuf sb; 3739 struct nameidata nd; 3740 const char *format; 3741 char *hostname, *name; 3742 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3743 3744 hostname = NULL; 3745 format = corefilename; 3746 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3747 indexlen = 0; 3748 indexpos = -1; 3749 ncores = num_cores; 3750 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3751 sx_slock(&corefilename_lock); 3752 for (i = 0; format[i] != '\0'; i++) { 3753 switch (format[i]) { 3754 case '%': /* Format character */ 3755 i++; 3756 switch (format[i]) { 3757 case '%': 3758 sbuf_putc(&sb, '%'); 3759 break; 3760 case 'H': /* hostname */ 3761 if (hostname == NULL) { 3762 hostname = malloc(MAXHOSTNAMELEN, 3763 M_TEMP, M_WAITOK); 3764 } 3765 getcredhostname(td->td_ucred, hostname, 3766 MAXHOSTNAMELEN); 3767 sbuf_printf(&sb, "%s", hostname); 3768 break; 3769 case 'I': /* autoincrementing index */ 3770 if (indexpos != -1) { 3771 sbuf_printf(&sb, "%%I"); 3772 break; 3773 } 3774 3775 indexpos = sbuf_len(&sb); 3776 sbuf_printf(&sb, "%u", ncores - 1); 3777 indexlen = sbuf_len(&sb) - indexpos; 3778 break; 3779 case 'N': /* process name */ 3780 sbuf_printf(&sb, "%s", comm); 3781 break; 3782 case 'P': /* process id */ 3783 sbuf_printf(&sb, "%u", pid); 3784 break; 3785 case 'S': /* signal number */ 3786 sbuf_printf(&sb, "%i", signum); 3787 break; 3788 case 'U': /* user id */ 3789 sbuf_printf(&sb, "%u", uid); 3790 break; 3791 default: 3792 log(LOG_ERR, 3793 "Unknown format character %c in " 3794 "corename `%s'\n", format[i], format); 3795 break; 3796 } 3797 break; 3798 default: 3799 sbuf_putc(&sb, format[i]); 3800 break; 3801 } 3802 } 3803 sx_sunlock(&corefilename_lock); 3804 free(hostname, M_TEMP); 3805 if (compress == COMPRESS_GZIP) 3806 sbuf_printf(&sb, GZIP_SUFFIX); 3807 else if (compress == COMPRESS_ZSTD) 3808 sbuf_printf(&sb, ZSTD_SUFFIX); 3809 if (sbuf_error(&sb) != 0) { 3810 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3811 "long\n", (long)pid, comm, (u_long)uid); 3812 sbuf_delete(&sb); 3813 free(name, M_TEMP); 3814 return (ENOMEM); 3815 } 3816 sbuf_finish(&sb); 3817 sbuf_delete(&sb); 3818 3819 if (indexpos != -1) { 3820 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3821 vpp); 3822 if (error != 0) { 3823 log(LOG_ERR, 3824 "pid %d (%s), uid (%u): Path `%s' failed " 3825 "on initial open test, error = %d\n", 3826 pid, comm, uid, name, error); 3827 } 3828 } else { 3829 cmode = S_IRUSR | S_IWUSR; 3830 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3831 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3832 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3833 if ((td->td_proc->p_flag & P_SUGID) != 0) 3834 flags |= O_EXCL; 3835 3836 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name); 3837 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3838 NULL); 3839 if (error == 0) { 3840 *vpp = nd.ni_vp; 3841 NDFREE(&nd, NDF_ONLY_PNBUF); 3842 } 3843 } 3844 3845 if (error != 0) { 3846 #ifdef AUDIT 3847 audit_proc_coredump(td, name, error); 3848 #endif 3849 free(name, M_TEMP); 3850 return (error); 3851 } 3852 *namep = name; 3853 return (0); 3854 } 3855 3856 /* 3857 * Dump a process' core. The main routine does some 3858 * policy checking, and creates the name of the coredump; 3859 * then it passes on a vnode and a size limit to the process-specific 3860 * coredump routine if there is one; if there _is not_ one, it returns 3861 * ENOSYS; otherwise it returns the error from the process-specific routine. 3862 */ 3863 3864 static int 3865 coredump(struct thread *td) 3866 { 3867 struct proc *p = td->td_proc; 3868 struct ucred *cred = td->td_ucred; 3869 struct vnode *vp; 3870 struct flock lf; 3871 struct vattr vattr; 3872 size_t fullpathsize; 3873 int error, error1, locked; 3874 char *name; /* name of corefile */ 3875 void *rl_cookie; 3876 off_t limit; 3877 char *fullpath, *freepath = NULL; 3878 struct sbuf *sb; 3879 3880 PROC_LOCK_ASSERT(p, MA_OWNED); 3881 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3882 3883 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3884 (p->p_flag2 & P2_NOTRACE) != 0) { 3885 PROC_UNLOCK(p); 3886 return (EFAULT); 3887 } 3888 3889 /* 3890 * Note that the bulk of limit checking is done after 3891 * the corefile is created. The exception is if the limit 3892 * for corefiles is 0, in which case we don't bother 3893 * creating the corefile at all. This layout means that 3894 * a corefile is truncated instead of not being created, 3895 * if it is larger than the limit. 3896 */ 3897 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3898 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3899 PROC_UNLOCK(p); 3900 return (EFBIG); 3901 } 3902 PROC_UNLOCK(p); 3903 3904 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3905 compress_user_cores, p->p_sig, &vp, &name); 3906 if (error != 0) 3907 return (error); 3908 3909 /* 3910 * Don't dump to non-regular files or files with links. 3911 * Do not dump into system files. Effective user must own the corefile. 3912 */ 3913 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3914 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 3915 vattr.va_uid != cred->cr_uid) { 3916 VOP_UNLOCK(vp); 3917 error = EFAULT; 3918 goto out; 3919 } 3920 3921 VOP_UNLOCK(vp); 3922 3923 /* Postpone other writers, including core dumps of other processes. */ 3924 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3925 3926 lf.l_whence = SEEK_SET; 3927 lf.l_start = 0; 3928 lf.l_len = 0; 3929 lf.l_type = F_WRLCK; 3930 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3931 3932 VATTR_NULL(&vattr); 3933 vattr.va_size = 0; 3934 if (set_core_nodump_flag) 3935 vattr.va_flags = UF_NODUMP; 3936 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3937 VOP_SETATTR(vp, &vattr, cred); 3938 VOP_UNLOCK(vp); 3939 PROC_LOCK(p); 3940 p->p_acflag |= ACORE; 3941 PROC_UNLOCK(p); 3942 3943 if (p->p_sysent->sv_coredump != NULL) { 3944 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3945 } else { 3946 error = ENOSYS; 3947 } 3948 3949 if (locked) { 3950 lf.l_type = F_UNLCK; 3951 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3952 } 3953 vn_rangelock_unlock(vp, rl_cookie); 3954 3955 /* 3956 * Notify the userland helper that a process triggered a core dump. 3957 * This allows the helper to run an automated debugging session. 3958 */ 3959 if (error != 0 || coredump_devctl == 0) 3960 goto out; 3961 sb = sbuf_new_auto(); 3962 if (vn_fullpath_global(p->p_textvp, &fullpath, &freepath) != 0) 3963 goto out2; 3964 sbuf_printf(sb, "comm=\""); 3965 devctl_safe_quote_sb(sb, fullpath); 3966 free(freepath, M_TEMP); 3967 sbuf_printf(sb, "\" core=\""); 3968 3969 /* 3970 * We can't lookup core file vp directly. When we're replacing a core, and 3971 * other random times, we flush the name cache, so it will fail. Instead, 3972 * if the path of the core is relative, add the current dir in front if it. 3973 */ 3974 if (name[0] != '/') { 3975 fullpathsize = MAXPATHLEN; 3976 freepath = malloc(fullpathsize, M_TEMP, M_WAITOK); 3977 if (vn_getcwd(freepath, &fullpath, &fullpathsize) != 0) { 3978 free(freepath, M_TEMP); 3979 goto out2; 3980 } 3981 devctl_safe_quote_sb(sb, fullpath); 3982 free(freepath, M_TEMP); 3983 sbuf_putc(sb, '/'); 3984 } 3985 devctl_safe_quote_sb(sb, name); 3986 sbuf_printf(sb, "\""); 3987 if (sbuf_finish(sb) == 0) 3988 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 3989 out2: 3990 sbuf_delete(sb); 3991 out: 3992 error1 = vn_close(vp, FWRITE, cred, td); 3993 if (error == 0) 3994 error = error1; 3995 #ifdef AUDIT 3996 audit_proc_coredump(td, name, error); 3997 #endif 3998 free(name, M_TEMP); 3999 return (error); 4000 } 4001 4002 /* 4003 * Nonexistent system call-- signal process (may want to handle it). Flag 4004 * error in case process won't see signal immediately (blocked or ignored). 4005 */ 4006 #ifndef _SYS_SYSPROTO_H_ 4007 struct nosys_args { 4008 int dummy; 4009 }; 4010 #endif 4011 /* ARGSUSED */ 4012 int 4013 nosys(struct thread *td, struct nosys_args *args) 4014 { 4015 struct proc *p; 4016 4017 p = td->td_proc; 4018 4019 PROC_LOCK(p); 4020 tdsignal(td, SIGSYS); 4021 PROC_UNLOCK(p); 4022 if (kern_lognosys == 1 || kern_lognosys == 3) { 4023 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 4024 td->td_sa.code); 4025 } 4026 if (kern_lognosys == 2 || kern_lognosys == 3 || 4027 (p->p_pid == 1 && (kern_lognosys & 3) == 0)) { 4028 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 4029 td->td_sa.code); 4030 } 4031 return (ENOSYS); 4032 } 4033 4034 /* 4035 * Send a SIGIO or SIGURG signal to a process or process group using stored 4036 * credentials rather than those of the current process. 4037 */ 4038 void 4039 pgsigio(struct sigio **sigiop, int sig, int checkctty) 4040 { 4041 ksiginfo_t ksi; 4042 struct sigio *sigio; 4043 4044 ksiginfo_init(&ksi); 4045 ksi.ksi_signo = sig; 4046 ksi.ksi_code = SI_KERNEL; 4047 4048 SIGIO_LOCK(); 4049 sigio = *sigiop; 4050 if (sigio == NULL) { 4051 SIGIO_UNLOCK(); 4052 return; 4053 } 4054 if (sigio->sio_pgid > 0) { 4055 PROC_LOCK(sigio->sio_proc); 4056 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 4057 kern_psignal(sigio->sio_proc, sig); 4058 PROC_UNLOCK(sigio->sio_proc); 4059 } else if (sigio->sio_pgid < 0) { 4060 struct proc *p; 4061 4062 PGRP_LOCK(sigio->sio_pgrp); 4063 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 4064 PROC_LOCK(p); 4065 if (p->p_state == PRS_NORMAL && 4066 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 4067 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 4068 kern_psignal(p, sig); 4069 PROC_UNLOCK(p); 4070 } 4071 PGRP_UNLOCK(sigio->sio_pgrp); 4072 } 4073 SIGIO_UNLOCK(); 4074 } 4075 4076 static int 4077 filt_sigattach(struct knote *kn) 4078 { 4079 struct proc *p = curproc; 4080 4081 kn->kn_ptr.p_proc = p; 4082 kn->kn_flags |= EV_CLEAR; /* automatically set */ 4083 4084 knlist_add(p->p_klist, kn, 0); 4085 4086 return (0); 4087 } 4088 4089 static void 4090 filt_sigdetach(struct knote *kn) 4091 { 4092 struct proc *p = kn->kn_ptr.p_proc; 4093 4094 knlist_remove(p->p_klist, kn, 0); 4095 } 4096 4097 /* 4098 * signal knotes are shared with proc knotes, so we apply a mask to 4099 * the hint in order to differentiate them from process hints. This 4100 * could be avoided by using a signal-specific knote list, but probably 4101 * isn't worth the trouble. 4102 */ 4103 static int 4104 filt_signal(struct knote *kn, long hint) 4105 { 4106 4107 if (hint & NOTE_SIGNAL) { 4108 hint &= ~NOTE_SIGNAL; 4109 4110 if (kn->kn_id == hint) 4111 kn->kn_data++; 4112 } 4113 return (kn->kn_data != 0); 4114 } 4115 4116 struct sigacts * 4117 sigacts_alloc(void) 4118 { 4119 struct sigacts *ps; 4120 4121 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 4122 refcount_init(&ps->ps_refcnt, 1); 4123 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 4124 return (ps); 4125 } 4126 4127 void 4128 sigacts_free(struct sigacts *ps) 4129 { 4130 4131 if (refcount_release(&ps->ps_refcnt) == 0) 4132 return; 4133 mtx_destroy(&ps->ps_mtx); 4134 free(ps, M_SUBPROC); 4135 } 4136 4137 struct sigacts * 4138 sigacts_hold(struct sigacts *ps) 4139 { 4140 4141 refcount_acquire(&ps->ps_refcnt); 4142 return (ps); 4143 } 4144 4145 void 4146 sigacts_copy(struct sigacts *dest, struct sigacts *src) 4147 { 4148 4149 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 4150 mtx_lock(&src->ps_mtx); 4151 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 4152 mtx_unlock(&src->ps_mtx); 4153 } 4154 4155 int 4156 sigacts_shared(struct sigacts *ps) 4157 { 4158 4159 return (ps->ps_refcnt > 1); 4160 } 4161 4162 void 4163 sig_drop_caught(struct proc *p) 4164 { 4165 int sig; 4166 struct sigacts *ps; 4167 4168 ps = p->p_sigacts; 4169 PROC_LOCK_ASSERT(p, MA_OWNED); 4170 mtx_assert(&ps->ps_mtx, MA_OWNED); 4171 SIG_FOREACH(sig, &ps->ps_sigcatch) { 4172 sigdflt(ps, sig); 4173 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 4174 sigqueue_delete_proc(p, sig); 4175 } 4176 } 4177 4178 static void 4179 sigfastblock_failed(struct thread *td, bool sendsig, bool write) 4180 { 4181 ksiginfo_t ksi; 4182 4183 /* 4184 * Prevent further fetches and SIGSEGVs, allowing thread to 4185 * issue syscalls despite corruption. 4186 */ 4187 sigfastblock_clear(td); 4188 4189 if (!sendsig) 4190 return; 4191 ksiginfo_init_trap(&ksi); 4192 ksi.ksi_signo = SIGSEGV; 4193 ksi.ksi_code = write ? SEGV_ACCERR : SEGV_MAPERR; 4194 ksi.ksi_addr = td->td_sigblock_ptr; 4195 trapsignal(td, &ksi); 4196 } 4197 4198 static bool 4199 sigfastblock_fetch_sig(struct thread *td, bool sendsig, uint32_t *valp) 4200 { 4201 uint32_t res; 4202 4203 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4204 return (true); 4205 if (fueword32((void *)td->td_sigblock_ptr, &res) == -1) { 4206 sigfastblock_failed(td, sendsig, false); 4207 return (false); 4208 } 4209 *valp = res; 4210 td->td_sigblock_val = res & ~SIGFASTBLOCK_FLAGS; 4211 return (true); 4212 } 4213 4214 static void 4215 sigfastblock_resched(struct thread *td, bool resched) 4216 { 4217 struct proc *p; 4218 4219 if (resched) { 4220 p = td->td_proc; 4221 PROC_LOCK(p); 4222 reschedule_signals(p, td->td_sigmask, 0); 4223 PROC_UNLOCK(p); 4224 } 4225 thread_lock(td); 4226 td->td_flags |= TDF_ASTPENDING | TDF_NEEDSIGCHK; 4227 thread_unlock(td); 4228 } 4229 4230 int 4231 sys_sigfastblock(struct thread *td, struct sigfastblock_args *uap) 4232 { 4233 struct proc *p; 4234 int error, res; 4235 uint32_t oldval; 4236 4237 error = 0; 4238 p = td->td_proc; 4239 switch (uap->cmd) { 4240 case SIGFASTBLOCK_SETPTR: 4241 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 4242 error = EBUSY; 4243 break; 4244 } 4245 if (((uintptr_t)(uap->ptr) & (sizeof(uint32_t) - 1)) != 0) { 4246 error = EINVAL; 4247 break; 4248 } 4249 td->td_pflags |= TDP_SIGFASTBLOCK; 4250 td->td_sigblock_ptr = uap->ptr; 4251 break; 4252 4253 case SIGFASTBLOCK_UNBLOCK: 4254 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4255 error = EINVAL; 4256 break; 4257 } 4258 4259 for (;;) { 4260 res = casueword32(td->td_sigblock_ptr, 4261 SIGFASTBLOCK_PEND, &oldval, 0); 4262 if (res == -1) { 4263 error = EFAULT; 4264 sigfastblock_failed(td, false, true); 4265 break; 4266 } 4267 if (res == 0) 4268 break; 4269 MPASS(res == 1); 4270 if (oldval != SIGFASTBLOCK_PEND) { 4271 error = EBUSY; 4272 break; 4273 } 4274 error = thread_check_susp(td, false); 4275 if (error != 0) 4276 break; 4277 } 4278 if (error != 0) 4279 break; 4280 4281 /* 4282 * td_sigblock_val is cleared there, but not on a 4283 * syscall exit. The end effect is that a single 4284 * interruptible sleep, while user sigblock word is 4285 * set, might return EINTR or ERESTART to usermode 4286 * without delivering signal. All further sleeps, 4287 * until userspace clears the word and does 4288 * sigfastblock(UNBLOCK), observe current word and no 4289 * longer get interrupted. It is slight 4290 * non-conformance, with alternative to have read the 4291 * sigblock word on each syscall entry. 4292 */ 4293 td->td_sigblock_val = 0; 4294 4295 /* 4296 * Rely on normal ast mechanism to deliver pending 4297 * signals to current thread. But notify others about 4298 * fake unblock. 4299 */ 4300 sigfastblock_resched(td, error == 0 && p->p_numthreads != 1); 4301 4302 break; 4303 4304 case SIGFASTBLOCK_UNSETPTR: 4305 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4306 error = EINVAL; 4307 break; 4308 } 4309 if (!sigfastblock_fetch_sig(td, false, &oldval)) { 4310 error = EFAULT; 4311 break; 4312 } 4313 if (oldval != 0 && oldval != SIGFASTBLOCK_PEND) { 4314 error = EBUSY; 4315 break; 4316 } 4317 sigfastblock_clear(td); 4318 break; 4319 4320 default: 4321 error = EINVAL; 4322 break; 4323 } 4324 return (error); 4325 } 4326 4327 void 4328 sigfastblock_clear(struct thread *td) 4329 { 4330 bool resched; 4331 4332 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4333 return; 4334 td->td_sigblock_val = 0; 4335 resched = (td->td_pflags & TDP_SIGFASTPENDING) != 0 || 4336 SIGPENDING(td); 4337 td->td_pflags &= ~(TDP_SIGFASTBLOCK | TDP_SIGFASTPENDING); 4338 sigfastblock_resched(td, resched); 4339 } 4340 4341 void 4342 sigfastblock_fetch(struct thread *td) 4343 { 4344 uint32_t val; 4345 4346 (void)sigfastblock_fetch_sig(td, true, &val); 4347 } 4348 4349 static void 4350 sigfastblock_setpend1(struct thread *td) 4351 { 4352 int res; 4353 uint32_t oldval; 4354 4355 if ((td->td_pflags & TDP_SIGFASTPENDING) == 0) 4356 return; 4357 res = fueword32((void *)td->td_sigblock_ptr, &oldval); 4358 if (res == -1) { 4359 sigfastblock_failed(td, true, false); 4360 return; 4361 } 4362 for (;;) { 4363 res = casueword32(td->td_sigblock_ptr, oldval, &oldval, 4364 oldval | SIGFASTBLOCK_PEND); 4365 if (res == -1) { 4366 sigfastblock_failed(td, true, true); 4367 return; 4368 } 4369 if (res == 0) { 4370 td->td_sigblock_val = oldval & ~SIGFASTBLOCK_FLAGS; 4371 td->td_pflags &= ~TDP_SIGFASTPENDING; 4372 break; 4373 } 4374 MPASS(res == 1); 4375 if (thread_check_susp(td, false) != 0) 4376 break; 4377 } 4378 } 4379 4380 void 4381 sigfastblock_setpend(struct thread *td, bool resched) 4382 { 4383 struct proc *p; 4384 4385 sigfastblock_setpend1(td); 4386 if (resched) { 4387 p = td->td_proc; 4388 PROC_LOCK(p); 4389 reschedule_signals(p, fastblock_mask, SIGPROCMASK_FASTBLK); 4390 PROC_UNLOCK(p); 4391 } 4392 } 4393