1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/ctype.h> 46 #include <sys/systm.h> 47 #include <sys/signalvar.h> 48 #include <sys/vnode.h> 49 #include <sys/acct.h> 50 #include <sys/capsicum.h> 51 #include <sys/compressor.h> 52 #include <sys/condvar.h> 53 #include <sys/devctl.h> 54 #include <sys/event.h> 55 #include <sys/fcntl.h> 56 #include <sys/imgact.h> 57 #include <sys/kernel.h> 58 #include <sys/ktr.h> 59 #include <sys/ktrace.h> 60 #include <sys/limits.h> 61 #include <sys/lock.h> 62 #include <sys/malloc.h> 63 #include <sys/mutex.h> 64 #include <sys/refcount.h> 65 #include <sys/namei.h> 66 #include <sys/proc.h> 67 #include <sys/procdesc.h> 68 #include <sys/ptrace.h> 69 #include <sys/posix4.h> 70 #include <sys/racct.h> 71 #include <sys/resourcevar.h> 72 #include <sys/sdt.h> 73 #include <sys/sbuf.h> 74 #include <sys/sleepqueue.h> 75 #include <sys/smp.h> 76 #include <sys/stat.h> 77 #include <sys/sx.h> 78 #include <sys/syscallsubr.h> 79 #include <sys/sysctl.h> 80 #include <sys/sysent.h> 81 #include <sys/syslog.h> 82 #include <sys/sysproto.h> 83 #include <sys/timers.h> 84 #include <sys/unistd.h> 85 #include <sys/wait.h> 86 #include <vm/vm.h> 87 #include <vm/vm_extern.h> 88 #include <vm/uma.h> 89 90 #include <sys/jail.h> 91 92 #include <machine/cpu.h> 93 94 #include <security/audit/audit.h> 95 96 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 97 98 SDT_PROVIDER_DECLARE(proc); 99 SDT_PROBE_DEFINE3(proc, , , signal__send, 100 "struct thread *", "struct proc *", "int"); 101 SDT_PROBE_DEFINE2(proc, , , signal__clear, 102 "int", "ksiginfo_t *"); 103 SDT_PROBE_DEFINE3(proc, , , signal__discard, 104 "struct thread *", "struct proc *", "int"); 105 106 static int coredump(struct thread *); 107 static int killpg1(struct thread *td, int sig, int pgid, int all, 108 ksiginfo_t *ksi); 109 static int issignal(struct thread *td); 110 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 111 static int sigprop(int sig); 112 static void tdsigwakeup(struct thread *, int, sig_t, int); 113 static int sig_suspend_threads(struct thread *, struct proc *, int); 114 static int filt_sigattach(struct knote *kn); 115 static void filt_sigdetach(struct knote *kn); 116 static int filt_signal(struct knote *kn, long hint); 117 static struct thread *sigtd(struct proc *p, int sig, bool fast_sigblock); 118 static void sigqueue_start(void); 119 120 static uma_zone_t ksiginfo_zone = NULL; 121 struct filterops sig_filtops = { 122 .f_isfd = 0, 123 .f_attach = filt_sigattach, 124 .f_detach = filt_sigdetach, 125 .f_event = filt_signal, 126 }; 127 128 static int kern_logsigexit = 1; 129 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 130 &kern_logsigexit, 0, 131 "Log processes quitting on abnormal signals to syslog(3)"); 132 133 static int kern_forcesigexit = 1; 134 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 135 &kern_forcesigexit, 0, "Force trap signal to be handled"); 136 137 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 138 "POSIX real time signal"); 139 140 static int max_pending_per_proc = 128; 141 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 142 &max_pending_per_proc, 0, "Max pending signals per proc"); 143 144 static int preallocate_siginfo = 1024; 145 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 146 &preallocate_siginfo, 0, "Preallocated signal memory size"); 147 148 static int signal_overflow = 0; 149 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 150 &signal_overflow, 0, "Number of signals overflew"); 151 152 static int signal_alloc_fail = 0; 153 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 154 &signal_alloc_fail, 0, "signals failed to be allocated"); 155 156 static int kern_lognosys = 0; 157 SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 158 "Log invalid syscalls"); 159 160 __read_frequently bool sigfastblock_fetch_always = false; 161 SYSCTL_BOOL(_kern, OID_AUTO, sigfastblock_fetch_always, CTLFLAG_RWTUN, 162 &sigfastblock_fetch_always, 0, 163 "Fetch sigfastblock word on each syscall entry for proper " 164 "blocking semantic"); 165 166 static bool kern_sig_discard_ign = true; 167 SYSCTL_BOOL(_kern, OID_AUTO, sig_discard_ign, CTLFLAG_RWTUN, 168 &kern_sig_discard_ign, 0, 169 "Discard ignored signals on delivery, otherwise queue them to " 170 "the target queue"); 171 172 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 173 174 /* 175 * Policy -- Can ucred cr1 send SIGIO to process cr2? 176 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 177 * in the right situations. 178 */ 179 #define CANSIGIO(cr1, cr2) \ 180 ((cr1)->cr_uid == 0 || \ 181 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 182 (cr1)->cr_uid == (cr2)->cr_ruid || \ 183 (cr1)->cr_ruid == (cr2)->cr_uid || \ 184 (cr1)->cr_uid == (cr2)->cr_uid) 185 186 static int sugid_coredump; 187 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 188 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 189 190 static int capmode_coredump; 191 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 192 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 193 194 static int do_coredump = 1; 195 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 196 &do_coredump, 0, "Enable/Disable coredumps"); 197 198 static int set_core_nodump_flag = 0; 199 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 200 0, "Enable setting the NODUMP flag on coredump files"); 201 202 static int coredump_devctl = 0; 203 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 204 0, "Generate a devctl notification when processes coredump"); 205 206 /* 207 * Signal properties and actions. 208 * The array below categorizes the signals and their default actions 209 * according to the following properties: 210 */ 211 #define SIGPROP_KILL 0x01 /* terminates process by default */ 212 #define SIGPROP_CORE 0x02 /* ditto and coredumps */ 213 #define SIGPROP_STOP 0x04 /* suspend process */ 214 #define SIGPROP_TTYSTOP 0x08 /* ditto, from tty */ 215 #define SIGPROP_IGNORE 0x10 /* ignore by default */ 216 #define SIGPROP_CONT 0x20 /* continue if suspended */ 217 218 static int sigproptbl[NSIG] = { 219 [SIGHUP] = SIGPROP_KILL, 220 [SIGINT] = SIGPROP_KILL, 221 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE, 222 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE, 223 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE, 224 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE, 225 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE, 226 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE, 227 [SIGKILL] = SIGPROP_KILL, 228 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE, 229 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE, 230 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE, 231 [SIGPIPE] = SIGPROP_KILL, 232 [SIGALRM] = SIGPROP_KILL, 233 [SIGTERM] = SIGPROP_KILL, 234 [SIGURG] = SIGPROP_IGNORE, 235 [SIGSTOP] = SIGPROP_STOP, 236 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP, 237 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT, 238 [SIGCHLD] = SIGPROP_IGNORE, 239 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP, 240 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP, 241 [SIGIO] = SIGPROP_IGNORE, 242 [SIGXCPU] = SIGPROP_KILL, 243 [SIGXFSZ] = SIGPROP_KILL, 244 [SIGVTALRM] = SIGPROP_KILL, 245 [SIGPROF] = SIGPROP_KILL, 246 [SIGWINCH] = SIGPROP_IGNORE, 247 [SIGINFO] = SIGPROP_IGNORE, 248 [SIGUSR1] = SIGPROP_KILL, 249 [SIGUSR2] = SIGPROP_KILL, 250 }; 251 252 #define _SIG_FOREACH_ADVANCE(i, set) ({ \ 253 int __found; \ 254 for (;;) { \ 255 if (__bits != 0) { \ 256 int __sig = ffs(__bits); \ 257 __bits &= ~(1u << (__sig - 1)); \ 258 sig = __i * sizeof((set)->__bits[0]) * NBBY + __sig; \ 259 __found = 1; \ 260 break; \ 261 } \ 262 if (++__i == _SIG_WORDS) { \ 263 __found = 0; \ 264 break; \ 265 } \ 266 __bits = (set)->__bits[__i]; \ 267 } \ 268 __found != 0; \ 269 }) 270 271 #define SIG_FOREACH(i, set) \ 272 for (int32_t __i = -1, __bits = 0; \ 273 _SIG_FOREACH_ADVANCE(i, set); ) \ 274 275 sigset_t fastblock_mask; 276 277 static void 278 sigqueue_start(void) 279 { 280 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 281 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 282 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 283 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 284 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 285 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 286 SIGFILLSET(fastblock_mask); 287 SIG_CANTMASK(fastblock_mask); 288 } 289 290 ksiginfo_t * 291 ksiginfo_alloc(int wait) 292 { 293 int flags; 294 295 flags = M_ZERO | (wait ? M_WAITOK : M_NOWAIT); 296 if (ksiginfo_zone != NULL) 297 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 298 return (NULL); 299 } 300 301 void 302 ksiginfo_free(ksiginfo_t *ksi) 303 { 304 uma_zfree(ksiginfo_zone, ksi); 305 } 306 307 static __inline int 308 ksiginfo_tryfree(ksiginfo_t *ksi) 309 { 310 if (!(ksi->ksi_flags & KSI_EXT)) { 311 uma_zfree(ksiginfo_zone, ksi); 312 return (1); 313 } 314 return (0); 315 } 316 317 void 318 sigqueue_init(sigqueue_t *list, struct proc *p) 319 { 320 SIGEMPTYSET(list->sq_signals); 321 SIGEMPTYSET(list->sq_kill); 322 SIGEMPTYSET(list->sq_ptrace); 323 TAILQ_INIT(&list->sq_list); 324 list->sq_proc = p; 325 list->sq_flags = SQ_INIT; 326 } 327 328 /* 329 * Get a signal's ksiginfo. 330 * Return: 331 * 0 - signal not found 332 * others - signal number 333 */ 334 static int 335 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 336 { 337 struct proc *p = sq->sq_proc; 338 struct ksiginfo *ksi, *next; 339 int count = 0; 340 341 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 342 343 if (!SIGISMEMBER(sq->sq_signals, signo)) 344 return (0); 345 346 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 347 count++; 348 SIGDELSET(sq->sq_ptrace, signo); 349 si->ksi_flags |= KSI_PTRACE; 350 } 351 if (SIGISMEMBER(sq->sq_kill, signo)) { 352 count++; 353 if (count == 1) 354 SIGDELSET(sq->sq_kill, signo); 355 } 356 357 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 358 if (ksi->ksi_signo == signo) { 359 if (count == 0) { 360 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 361 ksi->ksi_sigq = NULL; 362 ksiginfo_copy(ksi, si); 363 if (ksiginfo_tryfree(ksi) && p != NULL) 364 p->p_pendingcnt--; 365 } 366 if (++count > 1) 367 break; 368 } 369 } 370 371 if (count <= 1) 372 SIGDELSET(sq->sq_signals, signo); 373 si->ksi_signo = signo; 374 return (signo); 375 } 376 377 void 378 sigqueue_take(ksiginfo_t *ksi) 379 { 380 struct ksiginfo *kp; 381 struct proc *p; 382 sigqueue_t *sq; 383 384 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 385 return; 386 387 p = sq->sq_proc; 388 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 389 ksi->ksi_sigq = NULL; 390 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 391 p->p_pendingcnt--; 392 393 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 394 kp = TAILQ_NEXT(kp, ksi_link)) { 395 if (kp->ksi_signo == ksi->ksi_signo) 396 break; 397 } 398 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 399 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 400 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 401 } 402 403 static int 404 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 405 { 406 struct proc *p = sq->sq_proc; 407 struct ksiginfo *ksi; 408 int ret = 0; 409 410 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 411 412 /* 413 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 414 * for these signals. 415 */ 416 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 417 SIGADDSET(sq->sq_kill, signo); 418 goto out_set_bit; 419 } 420 421 /* directly insert the ksi, don't copy it */ 422 if (si->ksi_flags & KSI_INS) { 423 if (si->ksi_flags & KSI_HEAD) 424 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 425 else 426 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 427 si->ksi_sigq = sq; 428 goto out_set_bit; 429 } 430 431 if (__predict_false(ksiginfo_zone == NULL)) { 432 SIGADDSET(sq->sq_kill, signo); 433 goto out_set_bit; 434 } 435 436 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 437 signal_overflow++; 438 ret = EAGAIN; 439 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 440 signal_alloc_fail++; 441 ret = EAGAIN; 442 } else { 443 if (p != NULL) 444 p->p_pendingcnt++; 445 ksiginfo_copy(si, ksi); 446 ksi->ksi_signo = signo; 447 if (si->ksi_flags & KSI_HEAD) 448 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 449 else 450 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 451 ksi->ksi_sigq = sq; 452 } 453 454 if (ret != 0) { 455 if ((si->ksi_flags & KSI_PTRACE) != 0) { 456 SIGADDSET(sq->sq_ptrace, signo); 457 ret = 0; 458 goto out_set_bit; 459 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 460 (si->ksi_flags & KSI_SIGQ) == 0) { 461 SIGADDSET(sq->sq_kill, signo); 462 ret = 0; 463 goto out_set_bit; 464 } 465 return (ret); 466 } 467 468 out_set_bit: 469 SIGADDSET(sq->sq_signals, signo); 470 return (ret); 471 } 472 473 void 474 sigqueue_flush(sigqueue_t *sq) 475 { 476 struct proc *p = sq->sq_proc; 477 ksiginfo_t *ksi; 478 479 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 480 481 if (p != NULL) 482 PROC_LOCK_ASSERT(p, MA_OWNED); 483 484 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 485 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 486 ksi->ksi_sigq = NULL; 487 if (ksiginfo_tryfree(ksi) && p != NULL) 488 p->p_pendingcnt--; 489 } 490 491 SIGEMPTYSET(sq->sq_signals); 492 SIGEMPTYSET(sq->sq_kill); 493 SIGEMPTYSET(sq->sq_ptrace); 494 } 495 496 static void 497 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 498 { 499 sigset_t tmp; 500 struct proc *p1, *p2; 501 ksiginfo_t *ksi, *next; 502 503 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 504 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 505 p1 = src->sq_proc; 506 p2 = dst->sq_proc; 507 /* Move siginfo to target list */ 508 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 509 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 510 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 511 if (p1 != NULL) 512 p1->p_pendingcnt--; 513 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 514 ksi->ksi_sigq = dst; 515 if (p2 != NULL) 516 p2->p_pendingcnt++; 517 } 518 } 519 520 /* Move pending bits to target list */ 521 tmp = src->sq_kill; 522 SIGSETAND(tmp, *set); 523 SIGSETOR(dst->sq_kill, tmp); 524 SIGSETNAND(src->sq_kill, tmp); 525 526 tmp = src->sq_ptrace; 527 SIGSETAND(tmp, *set); 528 SIGSETOR(dst->sq_ptrace, tmp); 529 SIGSETNAND(src->sq_ptrace, tmp); 530 531 tmp = src->sq_signals; 532 SIGSETAND(tmp, *set); 533 SIGSETOR(dst->sq_signals, tmp); 534 SIGSETNAND(src->sq_signals, tmp); 535 } 536 537 #if 0 538 static void 539 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 540 { 541 sigset_t set; 542 543 SIGEMPTYSET(set); 544 SIGADDSET(set, signo); 545 sigqueue_move_set(src, dst, &set); 546 } 547 #endif 548 549 static void 550 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 551 { 552 struct proc *p = sq->sq_proc; 553 ksiginfo_t *ksi, *next; 554 555 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 556 557 /* Remove siginfo queue */ 558 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 559 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 560 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 561 ksi->ksi_sigq = NULL; 562 if (ksiginfo_tryfree(ksi) && p != NULL) 563 p->p_pendingcnt--; 564 } 565 } 566 SIGSETNAND(sq->sq_kill, *set); 567 SIGSETNAND(sq->sq_ptrace, *set); 568 SIGSETNAND(sq->sq_signals, *set); 569 } 570 571 void 572 sigqueue_delete(sigqueue_t *sq, int signo) 573 { 574 sigset_t set; 575 576 SIGEMPTYSET(set); 577 SIGADDSET(set, signo); 578 sigqueue_delete_set(sq, &set); 579 } 580 581 /* Remove a set of signals for a process */ 582 static void 583 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 584 { 585 sigqueue_t worklist; 586 struct thread *td0; 587 588 PROC_LOCK_ASSERT(p, MA_OWNED); 589 590 sigqueue_init(&worklist, NULL); 591 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 592 593 FOREACH_THREAD_IN_PROC(p, td0) 594 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 595 596 sigqueue_flush(&worklist); 597 } 598 599 void 600 sigqueue_delete_proc(struct proc *p, int signo) 601 { 602 sigset_t set; 603 604 SIGEMPTYSET(set); 605 SIGADDSET(set, signo); 606 sigqueue_delete_set_proc(p, &set); 607 } 608 609 static void 610 sigqueue_delete_stopmask_proc(struct proc *p) 611 { 612 sigset_t set; 613 614 SIGEMPTYSET(set); 615 SIGADDSET(set, SIGSTOP); 616 SIGADDSET(set, SIGTSTP); 617 SIGADDSET(set, SIGTTIN); 618 SIGADDSET(set, SIGTTOU); 619 sigqueue_delete_set_proc(p, &set); 620 } 621 622 /* 623 * Determine signal that should be delivered to thread td, the current 624 * thread, 0 if none. If there is a pending stop signal with default 625 * action, the process stops in issignal(). 626 */ 627 int 628 cursig(struct thread *td) 629 { 630 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 631 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 632 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 633 return (SIGPENDING(td) ? issignal(td) : 0); 634 } 635 636 /* 637 * Arrange for ast() to handle unmasked pending signals on return to user 638 * mode. This must be called whenever a signal is added to td_sigqueue or 639 * unmasked in td_sigmask. 640 */ 641 void 642 signotify(struct thread *td) 643 { 644 645 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 646 647 if (SIGPENDING(td)) { 648 thread_lock(td); 649 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 650 thread_unlock(td); 651 } 652 } 653 654 /* 655 * Returns 1 (true) if altstack is configured for the thread, and the 656 * passed stack bottom address falls into the altstack range. Handles 657 * the 43 compat special case where the alt stack size is zero. 658 */ 659 int 660 sigonstack(size_t sp) 661 { 662 struct thread *td; 663 664 td = curthread; 665 if ((td->td_pflags & TDP_ALTSTACK) == 0) 666 return (0); 667 #if defined(COMPAT_43) 668 if (SV_PROC_FLAG(td->td_proc, SV_AOUT) && td->td_sigstk.ss_size == 0) 669 return ((td->td_sigstk.ss_flags & SS_ONSTACK) != 0); 670 #endif 671 return (sp >= (size_t)td->td_sigstk.ss_sp && 672 sp < td->td_sigstk.ss_size + (size_t)td->td_sigstk.ss_sp); 673 } 674 675 static __inline int 676 sigprop(int sig) 677 { 678 679 if (sig > 0 && sig < nitems(sigproptbl)) 680 return (sigproptbl[sig]); 681 return (0); 682 } 683 684 static bool 685 sigact_flag_test(const struct sigaction *act, int flag) 686 { 687 688 /* 689 * SA_SIGINFO is reset when signal disposition is set to 690 * ignore or default. Other flags are kept according to user 691 * settings. 692 */ 693 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 694 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 695 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 696 } 697 698 /* 699 * kern_sigaction 700 * sigaction 701 * freebsd4_sigaction 702 * osigaction 703 */ 704 int 705 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 706 struct sigaction *oact, int flags) 707 { 708 struct sigacts *ps; 709 struct proc *p = td->td_proc; 710 711 if (!_SIG_VALID(sig)) 712 return (EINVAL); 713 if (act != NULL && act->sa_handler != SIG_DFL && 714 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 715 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 716 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 717 return (EINVAL); 718 719 PROC_LOCK(p); 720 ps = p->p_sigacts; 721 mtx_lock(&ps->ps_mtx); 722 if (oact) { 723 memset(oact, 0, sizeof(*oact)); 724 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 725 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 726 oact->sa_flags |= SA_ONSTACK; 727 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 728 oact->sa_flags |= SA_RESTART; 729 if (SIGISMEMBER(ps->ps_sigreset, sig)) 730 oact->sa_flags |= SA_RESETHAND; 731 if (SIGISMEMBER(ps->ps_signodefer, sig)) 732 oact->sa_flags |= SA_NODEFER; 733 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 734 oact->sa_flags |= SA_SIGINFO; 735 oact->sa_sigaction = 736 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 737 } else 738 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 739 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 740 oact->sa_flags |= SA_NOCLDSTOP; 741 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 742 oact->sa_flags |= SA_NOCLDWAIT; 743 } 744 if (act) { 745 if ((sig == SIGKILL || sig == SIGSTOP) && 746 act->sa_handler != SIG_DFL) { 747 mtx_unlock(&ps->ps_mtx); 748 PROC_UNLOCK(p); 749 return (EINVAL); 750 } 751 752 /* 753 * Change setting atomically. 754 */ 755 756 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 757 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 758 if (sigact_flag_test(act, SA_SIGINFO)) { 759 ps->ps_sigact[_SIG_IDX(sig)] = 760 (__sighandler_t *)act->sa_sigaction; 761 SIGADDSET(ps->ps_siginfo, sig); 762 } else { 763 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 764 SIGDELSET(ps->ps_siginfo, sig); 765 } 766 if (!sigact_flag_test(act, SA_RESTART)) 767 SIGADDSET(ps->ps_sigintr, sig); 768 else 769 SIGDELSET(ps->ps_sigintr, sig); 770 if (sigact_flag_test(act, SA_ONSTACK)) 771 SIGADDSET(ps->ps_sigonstack, sig); 772 else 773 SIGDELSET(ps->ps_sigonstack, sig); 774 if (sigact_flag_test(act, SA_RESETHAND)) 775 SIGADDSET(ps->ps_sigreset, sig); 776 else 777 SIGDELSET(ps->ps_sigreset, sig); 778 if (sigact_flag_test(act, SA_NODEFER)) 779 SIGADDSET(ps->ps_signodefer, sig); 780 else 781 SIGDELSET(ps->ps_signodefer, sig); 782 if (sig == SIGCHLD) { 783 if (act->sa_flags & SA_NOCLDSTOP) 784 ps->ps_flag |= PS_NOCLDSTOP; 785 else 786 ps->ps_flag &= ~PS_NOCLDSTOP; 787 if (act->sa_flags & SA_NOCLDWAIT) { 788 /* 789 * Paranoia: since SA_NOCLDWAIT is implemented 790 * by reparenting the dying child to PID 1 (and 791 * trust it to reap the zombie), PID 1 itself 792 * is forbidden to set SA_NOCLDWAIT. 793 */ 794 if (p->p_pid == 1) 795 ps->ps_flag &= ~PS_NOCLDWAIT; 796 else 797 ps->ps_flag |= PS_NOCLDWAIT; 798 } else 799 ps->ps_flag &= ~PS_NOCLDWAIT; 800 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 801 ps->ps_flag |= PS_CLDSIGIGN; 802 else 803 ps->ps_flag &= ~PS_CLDSIGIGN; 804 } 805 /* 806 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 807 * and for signals set to SIG_DFL where the default is to 808 * ignore. However, don't put SIGCONT in ps_sigignore, as we 809 * have to restart the process. 810 */ 811 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 812 (sigprop(sig) & SIGPROP_IGNORE && 813 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 814 /* never to be seen again */ 815 sigqueue_delete_proc(p, sig); 816 if (sig != SIGCONT) 817 /* easier in psignal */ 818 SIGADDSET(ps->ps_sigignore, sig); 819 SIGDELSET(ps->ps_sigcatch, sig); 820 } else { 821 SIGDELSET(ps->ps_sigignore, sig); 822 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 823 SIGDELSET(ps->ps_sigcatch, sig); 824 else 825 SIGADDSET(ps->ps_sigcatch, sig); 826 } 827 #ifdef COMPAT_FREEBSD4 828 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 829 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 830 (flags & KSA_FREEBSD4) == 0) 831 SIGDELSET(ps->ps_freebsd4, sig); 832 else 833 SIGADDSET(ps->ps_freebsd4, sig); 834 #endif 835 #ifdef COMPAT_43 836 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 837 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 838 (flags & KSA_OSIGSET) == 0) 839 SIGDELSET(ps->ps_osigset, sig); 840 else 841 SIGADDSET(ps->ps_osigset, sig); 842 #endif 843 } 844 mtx_unlock(&ps->ps_mtx); 845 PROC_UNLOCK(p); 846 return (0); 847 } 848 849 #ifndef _SYS_SYSPROTO_H_ 850 struct sigaction_args { 851 int sig; 852 struct sigaction *act; 853 struct sigaction *oact; 854 }; 855 #endif 856 int 857 sys_sigaction(struct thread *td, struct sigaction_args *uap) 858 { 859 struct sigaction act, oact; 860 struct sigaction *actp, *oactp; 861 int error; 862 863 actp = (uap->act != NULL) ? &act : NULL; 864 oactp = (uap->oact != NULL) ? &oact : NULL; 865 if (actp) { 866 error = copyin(uap->act, actp, sizeof(act)); 867 if (error) 868 return (error); 869 } 870 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 871 if (oactp && !error) 872 error = copyout(oactp, uap->oact, sizeof(oact)); 873 return (error); 874 } 875 876 #ifdef COMPAT_FREEBSD4 877 #ifndef _SYS_SYSPROTO_H_ 878 struct freebsd4_sigaction_args { 879 int sig; 880 struct sigaction *act; 881 struct sigaction *oact; 882 }; 883 #endif 884 int 885 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 886 { 887 struct sigaction act, oact; 888 struct sigaction *actp, *oactp; 889 int error; 890 891 actp = (uap->act != NULL) ? &act : NULL; 892 oactp = (uap->oact != NULL) ? &oact : NULL; 893 if (actp) { 894 error = copyin(uap->act, actp, sizeof(act)); 895 if (error) 896 return (error); 897 } 898 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 899 if (oactp && !error) 900 error = copyout(oactp, uap->oact, sizeof(oact)); 901 return (error); 902 } 903 #endif /* COMAPT_FREEBSD4 */ 904 905 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 906 #ifndef _SYS_SYSPROTO_H_ 907 struct osigaction_args { 908 int signum; 909 struct osigaction *nsa; 910 struct osigaction *osa; 911 }; 912 #endif 913 int 914 osigaction(struct thread *td, struct osigaction_args *uap) 915 { 916 struct osigaction sa; 917 struct sigaction nsa, osa; 918 struct sigaction *nsap, *osap; 919 int error; 920 921 if (uap->signum <= 0 || uap->signum >= ONSIG) 922 return (EINVAL); 923 924 nsap = (uap->nsa != NULL) ? &nsa : NULL; 925 osap = (uap->osa != NULL) ? &osa : NULL; 926 927 if (nsap) { 928 error = copyin(uap->nsa, &sa, sizeof(sa)); 929 if (error) 930 return (error); 931 nsap->sa_handler = sa.sa_handler; 932 nsap->sa_flags = sa.sa_flags; 933 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 934 } 935 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 936 if (osap && !error) { 937 sa.sa_handler = osap->sa_handler; 938 sa.sa_flags = osap->sa_flags; 939 SIG2OSIG(osap->sa_mask, sa.sa_mask); 940 error = copyout(&sa, uap->osa, sizeof(sa)); 941 } 942 return (error); 943 } 944 945 #if !defined(__i386__) 946 /* Avoid replicating the same stub everywhere */ 947 int 948 osigreturn(struct thread *td, struct osigreturn_args *uap) 949 { 950 951 return (nosys(td, (struct nosys_args *)uap)); 952 } 953 #endif 954 #endif /* COMPAT_43 */ 955 956 /* 957 * Initialize signal state for process 0; 958 * set to ignore signals that are ignored by default. 959 */ 960 void 961 siginit(struct proc *p) 962 { 963 int i; 964 struct sigacts *ps; 965 966 PROC_LOCK(p); 967 ps = p->p_sigacts; 968 mtx_lock(&ps->ps_mtx); 969 for (i = 1; i <= NSIG; i++) { 970 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 971 SIGADDSET(ps->ps_sigignore, i); 972 } 973 } 974 mtx_unlock(&ps->ps_mtx); 975 PROC_UNLOCK(p); 976 } 977 978 /* 979 * Reset specified signal to the default disposition. 980 */ 981 static void 982 sigdflt(struct sigacts *ps, int sig) 983 { 984 985 mtx_assert(&ps->ps_mtx, MA_OWNED); 986 SIGDELSET(ps->ps_sigcatch, sig); 987 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 988 SIGADDSET(ps->ps_sigignore, sig); 989 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 990 SIGDELSET(ps->ps_siginfo, sig); 991 } 992 993 /* 994 * Reset signals for an exec of the specified process. 995 */ 996 void 997 execsigs(struct proc *p) 998 { 999 struct sigacts *ps; 1000 struct thread *td; 1001 1002 /* 1003 * Reset caught signals. Held signals remain held 1004 * through td_sigmask (unless they were caught, 1005 * and are now ignored by default). 1006 */ 1007 PROC_LOCK_ASSERT(p, MA_OWNED); 1008 ps = p->p_sigacts; 1009 mtx_lock(&ps->ps_mtx); 1010 sig_drop_caught(p); 1011 1012 /* 1013 * Reset stack state to the user stack. 1014 * Clear set of signals caught on the signal stack. 1015 */ 1016 td = curthread; 1017 MPASS(td->td_proc == p); 1018 td->td_sigstk.ss_flags = SS_DISABLE; 1019 td->td_sigstk.ss_size = 0; 1020 td->td_sigstk.ss_sp = 0; 1021 td->td_pflags &= ~TDP_ALTSTACK; 1022 /* 1023 * Reset no zombies if child dies flag as Solaris does. 1024 */ 1025 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1026 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1027 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1028 mtx_unlock(&ps->ps_mtx); 1029 } 1030 1031 /* 1032 * kern_sigprocmask() 1033 * 1034 * Manipulate signal mask. 1035 */ 1036 int 1037 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1038 int flags) 1039 { 1040 sigset_t new_block, oset1; 1041 struct proc *p; 1042 int error; 1043 1044 p = td->td_proc; 1045 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1046 PROC_LOCK_ASSERT(p, MA_OWNED); 1047 else 1048 PROC_LOCK(p); 1049 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1050 ? MA_OWNED : MA_NOTOWNED); 1051 if (oset != NULL) 1052 *oset = td->td_sigmask; 1053 1054 error = 0; 1055 if (set != NULL) { 1056 switch (how) { 1057 case SIG_BLOCK: 1058 SIG_CANTMASK(*set); 1059 oset1 = td->td_sigmask; 1060 SIGSETOR(td->td_sigmask, *set); 1061 new_block = td->td_sigmask; 1062 SIGSETNAND(new_block, oset1); 1063 break; 1064 case SIG_UNBLOCK: 1065 SIGSETNAND(td->td_sigmask, *set); 1066 signotify(td); 1067 goto out; 1068 case SIG_SETMASK: 1069 SIG_CANTMASK(*set); 1070 oset1 = td->td_sigmask; 1071 if (flags & SIGPROCMASK_OLD) 1072 SIGSETLO(td->td_sigmask, *set); 1073 else 1074 td->td_sigmask = *set; 1075 new_block = td->td_sigmask; 1076 SIGSETNAND(new_block, oset1); 1077 signotify(td); 1078 break; 1079 default: 1080 error = EINVAL; 1081 goto out; 1082 } 1083 1084 /* 1085 * The new_block set contains signals that were not previously 1086 * blocked, but are blocked now. 1087 * 1088 * In case we block any signal that was not previously blocked 1089 * for td, and process has the signal pending, try to schedule 1090 * signal delivery to some thread that does not block the 1091 * signal, possibly waking it up. 1092 */ 1093 if (p->p_numthreads != 1) 1094 reschedule_signals(p, new_block, flags); 1095 } 1096 1097 out: 1098 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1099 PROC_UNLOCK(p); 1100 return (error); 1101 } 1102 1103 #ifndef _SYS_SYSPROTO_H_ 1104 struct sigprocmask_args { 1105 int how; 1106 const sigset_t *set; 1107 sigset_t *oset; 1108 }; 1109 #endif 1110 int 1111 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1112 { 1113 sigset_t set, oset; 1114 sigset_t *setp, *osetp; 1115 int error; 1116 1117 setp = (uap->set != NULL) ? &set : NULL; 1118 osetp = (uap->oset != NULL) ? &oset : NULL; 1119 if (setp) { 1120 error = copyin(uap->set, setp, sizeof(set)); 1121 if (error) 1122 return (error); 1123 } 1124 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1125 if (osetp && !error) { 1126 error = copyout(osetp, uap->oset, sizeof(oset)); 1127 } 1128 return (error); 1129 } 1130 1131 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1132 #ifndef _SYS_SYSPROTO_H_ 1133 struct osigprocmask_args { 1134 int how; 1135 osigset_t mask; 1136 }; 1137 #endif 1138 int 1139 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1140 { 1141 sigset_t set, oset; 1142 int error; 1143 1144 OSIG2SIG(uap->mask, set); 1145 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1146 SIG2OSIG(oset, td->td_retval[0]); 1147 return (error); 1148 } 1149 #endif /* COMPAT_43 */ 1150 1151 int 1152 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1153 { 1154 ksiginfo_t ksi; 1155 sigset_t set; 1156 int error; 1157 1158 error = copyin(uap->set, &set, sizeof(set)); 1159 if (error) { 1160 td->td_retval[0] = error; 1161 return (0); 1162 } 1163 1164 error = kern_sigtimedwait(td, set, &ksi, NULL); 1165 if (error) { 1166 /* 1167 * sigwait() function shall not return EINTR, but 1168 * the syscall does. Non-ancient libc provides the 1169 * wrapper which hides EINTR. Otherwise, EINTR return 1170 * is used by libthr to handle required cancellation 1171 * point in the sigwait(). 1172 */ 1173 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1174 return (ERESTART); 1175 td->td_retval[0] = error; 1176 return (0); 1177 } 1178 1179 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1180 td->td_retval[0] = error; 1181 return (0); 1182 } 1183 1184 int 1185 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1186 { 1187 struct timespec ts; 1188 struct timespec *timeout; 1189 sigset_t set; 1190 ksiginfo_t ksi; 1191 int error; 1192 1193 if (uap->timeout) { 1194 error = copyin(uap->timeout, &ts, sizeof(ts)); 1195 if (error) 1196 return (error); 1197 1198 timeout = &ts; 1199 } else 1200 timeout = NULL; 1201 1202 error = copyin(uap->set, &set, sizeof(set)); 1203 if (error) 1204 return (error); 1205 1206 error = kern_sigtimedwait(td, set, &ksi, timeout); 1207 if (error) 1208 return (error); 1209 1210 if (uap->info) 1211 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1212 1213 if (error == 0) 1214 td->td_retval[0] = ksi.ksi_signo; 1215 return (error); 1216 } 1217 1218 int 1219 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1220 { 1221 ksiginfo_t ksi; 1222 sigset_t set; 1223 int error; 1224 1225 error = copyin(uap->set, &set, sizeof(set)); 1226 if (error) 1227 return (error); 1228 1229 error = kern_sigtimedwait(td, set, &ksi, NULL); 1230 if (error) 1231 return (error); 1232 1233 if (uap->info) 1234 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1235 1236 if (error == 0) 1237 td->td_retval[0] = ksi.ksi_signo; 1238 return (error); 1239 } 1240 1241 static void 1242 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1243 { 1244 struct thread *thr; 1245 1246 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1247 if (thr == td) 1248 thr->td_si = *si; 1249 else 1250 thr->td_si.si_signo = 0; 1251 } 1252 } 1253 1254 int 1255 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1256 struct timespec *timeout) 1257 { 1258 struct sigacts *ps; 1259 sigset_t saved_mask, new_block; 1260 struct proc *p; 1261 int error, sig, timo, timevalid = 0; 1262 struct timespec rts, ets, ts; 1263 struct timeval tv; 1264 bool traced; 1265 1266 p = td->td_proc; 1267 error = 0; 1268 ets.tv_sec = 0; 1269 ets.tv_nsec = 0; 1270 traced = false; 1271 1272 /* Ensure the sigfastblock value is up to date. */ 1273 sigfastblock_fetch(td); 1274 1275 if (timeout != NULL) { 1276 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1277 timevalid = 1; 1278 getnanouptime(&rts); 1279 timespecadd(&rts, timeout, &ets); 1280 } 1281 } 1282 ksiginfo_init(ksi); 1283 /* Some signals can not be waited for. */ 1284 SIG_CANTMASK(waitset); 1285 ps = p->p_sigacts; 1286 PROC_LOCK(p); 1287 saved_mask = td->td_sigmask; 1288 SIGSETNAND(td->td_sigmask, waitset); 1289 if ((p->p_sysent->sv_flags & SV_SIG_DISCIGN) != 0 || 1290 !kern_sig_discard_ign) { 1291 thread_lock(td); 1292 td->td_flags |= TDF_SIGWAIT; 1293 thread_unlock(td); 1294 } 1295 for (;;) { 1296 mtx_lock(&ps->ps_mtx); 1297 sig = cursig(td); 1298 mtx_unlock(&ps->ps_mtx); 1299 KASSERT(sig >= 0, ("sig %d", sig)); 1300 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1301 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1302 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1303 error = 0; 1304 break; 1305 } 1306 } 1307 1308 if (error != 0) 1309 break; 1310 1311 /* 1312 * POSIX says this must be checked after looking for pending 1313 * signals. 1314 */ 1315 if (timeout != NULL) { 1316 if (!timevalid) { 1317 error = EINVAL; 1318 break; 1319 } 1320 getnanouptime(&rts); 1321 if (timespeccmp(&rts, &ets, >=)) { 1322 error = EAGAIN; 1323 break; 1324 } 1325 timespecsub(&ets, &rts, &ts); 1326 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1327 timo = tvtohz(&tv); 1328 } else { 1329 timo = 0; 1330 } 1331 1332 if (traced) { 1333 error = EINTR; 1334 break; 1335 } 1336 1337 error = msleep(&p->p_sigacts, &p->p_mtx, PPAUSE | PCATCH, 1338 "sigwait", timo); 1339 1340 /* The syscalls can not be restarted. */ 1341 if (error == ERESTART) 1342 error = EINTR; 1343 1344 /* We will calculate timeout by ourself. */ 1345 if (timeout != NULL && error == EAGAIN) 1346 error = 0; 1347 1348 /* 1349 * If PTRACE_SCE or PTRACE_SCX were set after 1350 * userspace entered the syscall, return spurious 1351 * EINTR after wait was done. Only do this as last 1352 * resort after rechecking for possible queued signals 1353 * and expired timeouts. 1354 */ 1355 if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0) 1356 traced = true; 1357 } 1358 thread_lock(td); 1359 td->td_flags &= ~TDF_SIGWAIT; 1360 thread_unlock(td); 1361 1362 new_block = saved_mask; 1363 SIGSETNAND(new_block, td->td_sigmask); 1364 td->td_sigmask = saved_mask; 1365 /* 1366 * Fewer signals can be delivered to us, reschedule signal 1367 * notification. 1368 */ 1369 if (p->p_numthreads != 1) 1370 reschedule_signals(p, new_block, 0); 1371 1372 if (error == 0) { 1373 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1374 1375 if (ksi->ksi_code == SI_TIMER) 1376 itimer_accept(p, ksi->ksi_timerid, ksi); 1377 1378 #ifdef KTRACE 1379 if (KTRPOINT(td, KTR_PSIG)) { 1380 sig_t action; 1381 1382 mtx_lock(&ps->ps_mtx); 1383 action = ps->ps_sigact[_SIG_IDX(sig)]; 1384 mtx_unlock(&ps->ps_mtx); 1385 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1386 } 1387 #endif 1388 if (sig == SIGKILL) { 1389 proc_td_siginfo_capture(td, &ksi->ksi_info); 1390 sigexit(td, sig); 1391 } 1392 } 1393 PROC_UNLOCK(p); 1394 return (error); 1395 } 1396 1397 #ifndef _SYS_SYSPROTO_H_ 1398 struct sigpending_args { 1399 sigset_t *set; 1400 }; 1401 #endif 1402 int 1403 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1404 { 1405 struct proc *p = td->td_proc; 1406 sigset_t pending; 1407 1408 PROC_LOCK(p); 1409 pending = p->p_sigqueue.sq_signals; 1410 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1411 PROC_UNLOCK(p); 1412 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1413 } 1414 1415 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1416 #ifndef _SYS_SYSPROTO_H_ 1417 struct osigpending_args { 1418 int dummy; 1419 }; 1420 #endif 1421 int 1422 osigpending(struct thread *td, struct osigpending_args *uap) 1423 { 1424 struct proc *p = td->td_proc; 1425 sigset_t pending; 1426 1427 PROC_LOCK(p); 1428 pending = p->p_sigqueue.sq_signals; 1429 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1430 PROC_UNLOCK(p); 1431 SIG2OSIG(pending, td->td_retval[0]); 1432 return (0); 1433 } 1434 #endif /* COMPAT_43 */ 1435 1436 #if defined(COMPAT_43) 1437 /* 1438 * Generalized interface signal handler, 4.3-compatible. 1439 */ 1440 #ifndef _SYS_SYSPROTO_H_ 1441 struct osigvec_args { 1442 int signum; 1443 struct sigvec *nsv; 1444 struct sigvec *osv; 1445 }; 1446 #endif 1447 /* ARGSUSED */ 1448 int 1449 osigvec(struct thread *td, struct osigvec_args *uap) 1450 { 1451 struct sigvec vec; 1452 struct sigaction nsa, osa; 1453 struct sigaction *nsap, *osap; 1454 int error; 1455 1456 if (uap->signum <= 0 || uap->signum >= ONSIG) 1457 return (EINVAL); 1458 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1459 osap = (uap->osv != NULL) ? &osa : NULL; 1460 if (nsap) { 1461 error = copyin(uap->nsv, &vec, sizeof(vec)); 1462 if (error) 1463 return (error); 1464 nsap->sa_handler = vec.sv_handler; 1465 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1466 nsap->sa_flags = vec.sv_flags; 1467 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1468 } 1469 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1470 if (osap && !error) { 1471 vec.sv_handler = osap->sa_handler; 1472 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1473 vec.sv_flags = osap->sa_flags; 1474 vec.sv_flags &= ~SA_NOCLDWAIT; 1475 vec.sv_flags ^= SA_RESTART; 1476 error = copyout(&vec, uap->osv, sizeof(vec)); 1477 } 1478 return (error); 1479 } 1480 1481 #ifndef _SYS_SYSPROTO_H_ 1482 struct osigblock_args { 1483 int mask; 1484 }; 1485 #endif 1486 int 1487 osigblock(struct thread *td, struct osigblock_args *uap) 1488 { 1489 sigset_t set, oset; 1490 1491 OSIG2SIG(uap->mask, set); 1492 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1493 SIG2OSIG(oset, td->td_retval[0]); 1494 return (0); 1495 } 1496 1497 #ifndef _SYS_SYSPROTO_H_ 1498 struct osigsetmask_args { 1499 int mask; 1500 }; 1501 #endif 1502 int 1503 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1504 { 1505 sigset_t set, oset; 1506 1507 OSIG2SIG(uap->mask, set); 1508 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1509 SIG2OSIG(oset, td->td_retval[0]); 1510 return (0); 1511 } 1512 #endif /* COMPAT_43 */ 1513 1514 /* 1515 * Suspend calling thread until signal, providing mask to be set in the 1516 * meantime. 1517 */ 1518 #ifndef _SYS_SYSPROTO_H_ 1519 struct sigsuspend_args { 1520 const sigset_t *sigmask; 1521 }; 1522 #endif 1523 /* ARGSUSED */ 1524 int 1525 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1526 { 1527 sigset_t mask; 1528 int error; 1529 1530 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1531 if (error) 1532 return (error); 1533 return (kern_sigsuspend(td, mask)); 1534 } 1535 1536 int 1537 kern_sigsuspend(struct thread *td, sigset_t mask) 1538 { 1539 struct proc *p = td->td_proc; 1540 int has_sig, sig; 1541 1542 /* Ensure the sigfastblock value is up to date. */ 1543 sigfastblock_fetch(td); 1544 1545 /* 1546 * When returning from sigsuspend, we want 1547 * the old mask to be restored after the 1548 * signal handler has finished. Thus, we 1549 * save it here and mark the sigacts structure 1550 * to indicate this. 1551 */ 1552 PROC_LOCK(p); 1553 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1554 SIGPROCMASK_PROC_LOCKED); 1555 td->td_pflags |= TDP_OLDMASK; 1556 1557 /* 1558 * Process signals now. Otherwise, we can get spurious wakeup 1559 * due to signal entered process queue, but delivered to other 1560 * thread. But sigsuspend should return only on signal 1561 * delivery. 1562 */ 1563 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1564 for (has_sig = 0; !has_sig;) { 1565 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1566 0) == 0) 1567 /* void */; 1568 thread_suspend_check(0); 1569 mtx_lock(&p->p_sigacts->ps_mtx); 1570 while ((sig = cursig(td)) != 0) { 1571 KASSERT(sig >= 0, ("sig %d", sig)); 1572 has_sig += postsig(sig); 1573 } 1574 mtx_unlock(&p->p_sigacts->ps_mtx); 1575 1576 /* 1577 * If PTRACE_SCE or PTRACE_SCX were set after 1578 * userspace entered the syscall, return spurious 1579 * EINTR. 1580 */ 1581 if ((p->p_ptevents & PTRACE_SYSCALL) != 0) 1582 has_sig += 1; 1583 } 1584 PROC_UNLOCK(p); 1585 td->td_errno = EINTR; 1586 td->td_pflags |= TDP_NERRNO; 1587 return (EJUSTRETURN); 1588 } 1589 1590 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1591 /* 1592 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1593 * convention: libc stub passes mask, not pointer, to save a copyin. 1594 */ 1595 #ifndef _SYS_SYSPROTO_H_ 1596 struct osigsuspend_args { 1597 osigset_t mask; 1598 }; 1599 #endif 1600 /* ARGSUSED */ 1601 int 1602 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1603 { 1604 sigset_t mask; 1605 1606 OSIG2SIG(uap->mask, mask); 1607 return (kern_sigsuspend(td, mask)); 1608 } 1609 #endif /* COMPAT_43 */ 1610 1611 #if defined(COMPAT_43) 1612 #ifndef _SYS_SYSPROTO_H_ 1613 struct osigstack_args { 1614 struct sigstack *nss; 1615 struct sigstack *oss; 1616 }; 1617 #endif 1618 /* ARGSUSED */ 1619 int 1620 osigstack(struct thread *td, struct osigstack_args *uap) 1621 { 1622 struct sigstack nss, oss; 1623 int error = 0; 1624 1625 if (uap->nss != NULL) { 1626 error = copyin(uap->nss, &nss, sizeof(nss)); 1627 if (error) 1628 return (error); 1629 } 1630 oss.ss_sp = td->td_sigstk.ss_sp; 1631 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1632 if (uap->nss != NULL) { 1633 td->td_sigstk.ss_sp = nss.ss_sp; 1634 td->td_sigstk.ss_size = 0; 1635 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1636 td->td_pflags |= TDP_ALTSTACK; 1637 } 1638 if (uap->oss != NULL) 1639 error = copyout(&oss, uap->oss, sizeof(oss)); 1640 1641 return (error); 1642 } 1643 #endif /* COMPAT_43 */ 1644 1645 #ifndef _SYS_SYSPROTO_H_ 1646 struct sigaltstack_args { 1647 stack_t *ss; 1648 stack_t *oss; 1649 }; 1650 #endif 1651 /* ARGSUSED */ 1652 int 1653 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1654 { 1655 stack_t ss, oss; 1656 int error; 1657 1658 if (uap->ss != NULL) { 1659 error = copyin(uap->ss, &ss, sizeof(ss)); 1660 if (error) 1661 return (error); 1662 } 1663 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1664 (uap->oss != NULL) ? &oss : NULL); 1665 if (error) 1666 return (error); 1667 if (uap->oss != NULL) 1668 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1669 return (error); 1670 } 1671 1672 int 1673 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1674 { 1675 struct proc *p = td->td_proc; 1676 int oonstack; 1677 1678 oonstack = sigonstack(cpu_getstack(td)); 1679 1680 if (oss != NULL) { 1681 *oss = td->td_sigstk; 1682 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1683 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1684 } 1685 1686 if (ss != NULL) { 1687 if (oonstack) 1688 return (EPERM); 1689 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1690 return (EINVAL); 1691 if (!(ss->ss_flags & SS_DISABLE)) { 1692 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1693 return (ENOMEM); 1694 1695 td->td_sigstk = *ss; 1696 td->td_pflags |= TDP_ALTSTACK; 1697 } else { 1698 td->td_pflags &= ~TDP_ALTSTACK; 1699 } 1700 } 1701 return (0); 1702 } 1703 1704 struct killpg1_ctx { 1705 struct thread *td; 1706 ksiginfo_t *ksi; 1707 int sig; 1708 bool sent; 1709 bool found; 1710 int ret; 1711 }; 1712 1713 static void 1714 killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg) 1715 { 1716 int err; 1717 1718 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 || 1719 (notself && p == arg->td->td_proc) || p->p_state == PRS_NEW) 1720 return; 1721 PROC_LOCK(p); 1722 err = p_cansignal(arg->td, p, arg->sig); 1723 if (err == 0 && arg->sig != 0) 1724 pksignal(p, arg->sig, arg->ksi); 1725 PROC_UNLOCK(p); 1726 if (err != ESRCH) 1727 arg->found = true; 1728 if (err == 0) 1729 arg->sent = true; 1730 else if (arg->ret == 0 && err != ESRCH && err != EPERM) 1731 arg->ret = err; 1732 } 1733 1734 /* 1735 * Common code for kill process group/broadcast kill. 1736 * cp is calling process. 1737 */ 1738 static int 1739 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1740 { 1741 struct proc *p; 1742 struct pgrp *pgrp; 1743 struct killpg1_ctx arg; 1744 1745 arg.td = td; 1746 arg.ksi = ksi; 1747 arg.sig = sig; 1748 arg.sent = false; 1749 arg.found = false; 1750 arg.ret = 0; 1751 if (all) { 1752 /* 1753 * broadcast 1754 */ 1755 sx_slock(&allproc_lock); 1756 FOREACH_PROC_IN_SYSTEM(p) { 1757 killpg1_sendsig(p, true, &arg); 1758 } 1759 sx_sunlock(&allproc_lock); 1760 } else { 1761 sx_slock(&proctree_lock); 1762 if (pgid == 0) { 1763 /* 1764 * zero pgid means send to my process group. 1765 */ 1766 pgrp = td->td_proc->p_pgrp; 1767 PGRP_LOCK(pgrp); 1768 } else { 1769 pgrp = pgfind(pgid); 1770 if (pgrp == NULL) { 1771 sx_sunlock(&proctree_lock); 1772 return (ESRCH); 1773 } 1774 } 1775 sx_sunlock(&proctree_lock); 1776 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1777 killpg1_sendsig(p, false, &arg); 1778 } 1779 PGRP_UNLOCK(pgrp); 1780 } 1781 MPASS(arg.ret != 0 || arg.found || !arg.sent); 1782 if (arg.ret == 0 && !arg.sent) 1783 arg.ret = arg.found ? EPERM : ESRCH; 1784 return (arg.ret); 1785 } 1786 1787 #ifndef _SYS_SYSPROTO_H_ 1788 struct kill_args { 1789 int pid; 1790 int signum; 1791 }; 1792 #endif 1793 /* ARGSUSED */ 1794 int 1795 sys_kill(struct thread *td, struct kill_args *uap) 1796 { 1797 1798 return (kern_kill(td, uap->pid, uap->signum)); 1799 } 1800 1801 int 1802 kern_kill(struct thread *td, pid_t pid, int signum) 1803 { 1804 ksiginfo_t ksi; 1805 struct proc *p; 1806 int error; 1807 1808 /* 1809 * A process in capability mode can send signals only to himself. 1810 * The main rationale behind this is that abort(3) is implemented as 1811 * kill(getpid(), SIGABRT). 1812 */ 1813 if (IN_CAPABILITY_MODE(td) && pid != td->td_proc->p_pid) 1814 return (ECAPMODE); 1815 1816 AUDIT_ARG_SIGNUM(signum); 1817 AUDIT_ARG_PID(pid); 1818 if ((u_int)signum > _SIG_MAXSIG) 1819 return (EINVAL); 1820 1821 ksiginfo_init(&ksi); 1822 ksi.ksi_signo = signum; 1823 ksi.ksi_code = SI_USER; 1824 ksi.ksi_pid = td->td_proc->p_pid; 1825 ksi.ksi_uid = td->td_ucred->cr_ruid; 1826 1827 if (pid > 0) { 1828 /* kill single process */ 1829 if ((p = pfind_any(pid)) == NULL) 1830 return (ESRCH); 1831 AUDIT_ARG_PROCESS(p); 1832 error = p_cansignal(td, p, signum); 1833 if (error == 0 && signum) 1834 pksignal(p, signum, &ksi); 1835 PROC_UNLOCK(p); 1836 return (error); 1837 } 1838 switch (pid) { 1839 case -1: /* broadcast signal */ 1840 return (killpg1(td, signum, 0, 1, &ksi)); 1841 case 0: /* signal own process group */ 1842 return (killpg1(td, signum, 0, 0, &ksi)); 1843 default: /* negative explicit process group */ 1844 return (killpg1(td, signum, -pid, 0, &ksi)); 1845 } 1846 /* NOTREACHED */ 1847 } 1848 1849 int 1850 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1851 { 1852 struct proc *p; 1853 int error; 1854 1855 AUDIT_ARG_SIGNUM(uap->signum); 1856 AUDIT_ARG_FD(uap->fd); 1857 if ((u_int)uap->signum > _SIG_MAXSIG) 1858 return (EINVAL); 1859 1860 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1861 if (error) 1862 return (error); 1863 AUDIT_ARG_PROCESS(p); 1864 error = p_cansignal(td, p, uap->signum); 1865 if (error == 0 && uap->signum) 1866 kern_psignal(p, uap->signum); 1867 PROC_UNLOCK(p); 1868 return (error); 1869 } 1870 1871 #if defined(COMPAT_43) 1872 #ifndef _SYS_SYSPROTO_H_ 1873 struct okillpg_args { 1874 int pgid; 1875 int signum; 1876 }; 1877 #endif 1878 /* ARGSUSED */ 1879 int 1880 okillpg(struct thread *td, struct okillpg_args *uap) 1881 { 1882 ksiginfo_t ksi; 1883 1884 AUDIT_ARG_SIGNUM(uap->signum); 1885 AUDIT_ARG_PID(uap->pgid); 1886 if ((u_int)uap->signum > _SIG_MAXSIG) 1887 return (EINVAL); 1888 1889 ksiginfo_init(&ksi); 1890 ksi.ksi_signo = uap->signum; 1891 ksi.ksi_code = SI_USER; 1892 ksi.ksi_pid = td->td_proc->p_pid; 1893 ksi.ksi_uid = td->td_ucred->cr_ruid; 1894 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1895 } 1896 #endif /* COMPAT_43 */ 1897 1898 #ifndef _SYS_SYSPROTO_H_ 1899 struct sigqueue_args { 1900 pid_t pid; 1901 int signum; 1902 /* union sigval */ void *value; 1903 }; 1904 #endif 1905 int 1906 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1907 { 1908 union sigval sv; 1909 1910 sv.sival_ptr = uap->value; 1911 1912 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1913 } 1914 1915 int 1916 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1917 { 1918 ksiginfo_t ksi; 1919 struct proc *p; 1920 int error; 1921 1922 if ((u_int)signum > _SIG_MAXSIG) 1923 return (EINVAL); 1924 1925 /* 1926 * Specification says sigqueue can only send signal to 1927 * single process. 1928 */ 1929 if (pid <= 0) 1930 return (EINVAL); 1931 1932 if ((p = pfind_any(pid)) == NULL) 1933 return (ESRCH); 1934 error = p_cansignal(td, p, signum); 1935 if (error == 0 && signum != 0) { 1936 ksiginfo_init(&ksi); 1937 ksi.ksi_flags = KSI_SIGQ; 1938 ksi.ksi_signo = signum; 1939 ksi.ksi_code = SI_QUEUE; 1940 ksi.ksi_pid = td->td_proc->p_pid; 1941 ksi.ksi_uid = td->td_ucred->cr_ruid; 1942 ksi.ksi_value = *value; 1943 error = pksignal(p, ksi.ksi_signo, &ksi); 1944 } 1945 PROC_UNLOCK(p); 1946 return (error); 1947 } 1948 1949 /* 1950 * Send a signal to a process group. 1951 */ 1952 void 1953 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1954 { 1955 struct pgrp *pgrp; 1956 1957 if (pgid != 0) { 1958 sx_slock(&proctree_lock); 1959 pgrp = pgfind(pgid); 1960 sx_sunlock(&proctree_lock); 1961 if (pgrp != NULL) { 1962 pgsignal(pgrp, sig, 0, ksi); 1963 PGRP_UNLOCK(pgrp); 1964 } 1965 } 1966 } 1967 1968 /* 1969 * Send a signal to a process group. If checktty is 1, 1970 * limit to members which have a controlling terminal. 1971 */ 1972 void 1973 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1974 { 1975 struct proc *p; 1976 1977 if (pgrp) { 1978 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1979 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1980 PROC_LOCK(p); 1981 if (p->p_state == PRS_NORMAL && 1982 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1983 pksignal(p, sig, ksi); 1984 PROC_UNLOCK(p); 1985 } 1986 } 1987 } 1988 1989 /* 1990 * Recalculate the signal mask and reset the signal disposition after 1991 * usermode frame for delivery is formed. Should be called after 1992 * mach-specific routine, because sysent->sv_sendsig() needs correct 1993 * ps_siginfo and signal mask. 1994 */ 1995 static void 1996 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1997 { 1998 sigset_t mask; 1999 2000 mtx_assert(&ps->ps_mtx, MA_OWNED); 2001 td->td_ru.ru_nsignals++; 2002 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2003 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2004 SIGADDSET(mask, sig); 2005 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2006 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2007 if (SIGISMEMBER(ps->ps_sigreset, sig)) 2008 sigdflt(ps, sig); 2009 } 2010 2011 /* 2012 * Send a signal caused by a trap to the current thread. If it will be 2013 * caught immediately, deliver it with correct code. Otherwise, post it 2014 * normally. 2015 */ 2016 void 2017 trapsignal(struct thread *td, ksiginfo_t *ksi) 2018 { 2019 struct sigacts *ps; 2020 struct proc *p; 2021 sigset_t sigmask; 2022 int code, sig; 2023 2024 p = td->td_proc; 2025 sig = ksi->ksi_signo; 2026 code = ksi->ksi_code; 2027 KASSERT(_SIG_VALID(sig), ("invalid signal")); 2028 2029 sigfastblock_fetch(td); 2030 PROC_LOCK(p); 2031 ps = p->p_sigacts; 2032 mtx_lock(&ps->ps_mtx); 2033 sigmask = td->td_sigmask; 2034 if (td->td_sigblock_val != 0) 2035 SIGSETOR(sigmask, fastblock_mask); 2036 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 2037 !SIGISMEMBER(sigmask, sig)) { 2038 #ifdef KTRACE 2039 if (KTRPOINT(curthread, KTR_PSIG)) 2040 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 2041 &td->td_sigmask, code); 2042 #endif 2043 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 2044 ksi, &td->td_sigmask); 2045 postsig_done(sig, td, ps); 2046 mtx_unlock(&ps->ps_mtx); 2047 } else { 2048 /* 2049 * Avoid a possible infinite loop if the thread 2050 * masking the signal or process is ignoring the 2051 * signal. 2052 */ 2053 if (kern_forcesigexit && (SIGISMEMBER(sigmask, sig) || 2054 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2055 SIGDELSET(td->td_sigmask, sig); 2056 SIGDELSET(ps->ps_sigcatch, sig); 2057 SIGDELSET(ps->ps_sigignore, sig); 2058 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2059 td->td_pflags &= ~TDP_SIGFASTBLOCK; 2060 td->td_sigblock_val = 0; 2061 } 2062 mtx_unlock(&ps->ps_mtx); 2063 p->p_sig = sig; /* XXX to verify code */ 2064 tdsendsignal(p, td, sig, ksi); 2065 } 2066 PROC_UNLOCK(p); 2067 } 2068 2069 static struct thread * 2070 sigtd(struct proc *p, int sig, bool fast_sigblock) 2071 { 2072 struct thread *td, *signal_td; 2073 2074 PROC_LOCK_ASSERT(p, MA_OWNED); 2075 MPASS(!fast_sigblock || p == curproc); 2076 2077 /* 2078 * Check if current thread can handle the signal without 2079 * switching context to another thread. 2080 */ 2081 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig) && 2082 (!fast_sigblock || curthread->td_sigblock_val == 0)) 2083 return (curthread); 2084 signal_td = NULL; 2085 FOREACH_THREAD_IN_PROC(p, td) { 2086 if (!SIGISMEMBER(td->td_sigmask, sig) && (!fast_sigblock || 2087 td != curthread || td->td_sigblock_val == 0)) { 2088 signal_td = td; 2089 break; 2090 } 2091 } 2092 if (signal_td == NULL) 2093 signal_td = FIRST_THREAD_IN_PROC(p); 2094 return (signal_td); 2095 } 2096 2097 /* 2098 * Send the signal to the process. If the signal has an action, the action 2099 * is usually performed by the target process rather than the caller; we add 2100 * the signal to the set of pending signals for the process. 2101 * 2102 * Exceptions: 2103 * o When a stop signal is sent to a sleeping process that takes the 2104 * default action, the process is stopped without awakening it. 2105 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2106 * regardless of the signal action (eg, blocked or ignored). 2107 * 2108 * Other ignored signals are discarded immediately. 2109 * 2110 * NB: This function may be entered from the debugger via the "kill" DDB 2111 * command. There is little that can be done to mitigate the possibly messy 2112 * side effects of this unwise possibility. 2113 */ 2114 void 2115 kern_psignal(struct proc *p, int sig) 2116 { 2117 ksiginfo_t ksi; 2118 2119 ksiginfo_init(&ksi); 2120 ksi.ksi_signo = sig; 2121 ksi.ksi_code = SI_KERNEL; 2122 (void) tdsendsignal(p, NULL, sig, &ksi); 2123 } 2124 2125 int 2126 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2127 { 2128 2129 return (tdsendsignal(p, NULL, sig, ksi)); 2130 } 2131 2132 /* Utility function for finding a thread to send signal event to. */ 2133 int 2134 sigev_findtd(struct proc *p, struct sigevent *sigev, struct thread **ttd) 2135 { 2136 struct thread *td; 2137 2138 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2139 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2140 if (td == NULL) 2141 return (ESRCH); 2142 *ttd = td; 2143 } else { 2144 *ttd = NULL; 2145 PROC_LOCK(p); 2146 } 2147 return (0); 2148 } 2149 2150 void 2151 tdsignal(struct thread *td, int sig) 2152 { 2153 ksiginfo_t ksi; 2154 2155 ksiginfo_init(&ksi); 2156 ksi.ksi_signo = sig; 2157 ksi.ksi_code = SI_KERNEL; 2158 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2159 } 2160 2161 void 2162 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2163 { 2164 2165 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2166 } 2167 2168 static int 2169 sig_sleepq_abort(struct thread *td, int intrval) 2170 { 2171 THREAD_LOCK_ASSERT(td, MA_OWNED); 2172 2173 if (intrval == 0 && (td->td_flags & TDF_SIGWAIT) == 0) { 2174 thread_unlock(td); 2175 return (0); 2176 } 2177 return (sleepq_abort(td, intrval)); 2178 } 2179 2180 int 2181 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2182 { 2183 sig_t action; 2184 sigqueue_t *sigqueue; 2185 int prop; 2186 struct sigacts *ps; 2187 int intrval; 2188 int ret = 0; 2189 int wakeup_swapper; 2190 2191 MPASS(td == NULL || p == td->td_proc); 2192 PROC_LOCK_ASSERT(p, MA_OWNED); 2193 2194 if (!_SIG_VALID(sig)) 2195 panic("%s(): invalid signal %d", __func__, sig); 2196 2197 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2198 2199 /* 2200 * IEEE Std 1003.1-2001: return success when killing a zombie. 2201 */ 2202 if (p->p_state == PRS_ZOMBIE) { 2203 if (ksi && (ksi->ksi_flags & KSI_INS)) 2204 ksiginfo_tryfree(ksi); 2205 return (ret); 2206 } 2207 2208 ps = p->p_sigacts; 2209 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2210 prop = sigprop(sig); 2211 2212 if (td == NULL) { 2213 td = sigtd(p, sig, false); 2214 sigqueue = &p->p_sigqueue; 2215 } else 2216 sigqueue = &td->td_sigqueue; 2217 2218 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2219 2220 /* 2221 * If the signal is being ignored, then we forget about it 2222 * immediately, except when the target process executes 2223 * sigwait(). (Note: we don't set SIGCONT in ps_sigignore, 2224 * and if it is set to SIG_IGN, action will be SIG_DFL here.) 2225 */ 2226 mtx_lock(&ps->ps_mtx); 2227 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2228 if (kern_sig_discard_ign && 2229 (p->p_sysent->sv_flags & SV_SIG_DISCIGN) == 0) { 2230 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2231 2232 mtx_unlock(&ps->ps_mtx); 2233 if (ksi && (ksi->ksi_flags & KSI_INS)) 2234 ksiginfo_tryfree(ksi); 2235 return (ret); 2236 } else { 2237 action = SIG_CATCH; 2238 intrval = 0; 2239 } 2240 } else { 2241 if (SIGISMEMBER(td->td_sigmask, sig)) 2242 action = SIG_HOLD; 2243 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2244 action = SIG_CATCH; 2245 else 2246 action = SIG_DFL; 2247 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2248 intrval = EINTR; 2249 else 2250 intrval = ERESTART; 2251 } 2252 mtx_unlock(&ps->ps_mtx); 2253 2254 if (prop & SIGPROP_CONT) 2255 sigqueue_delete_stopmask_proc(p); 2256 else if (prop & SIGPROP_STOP) { 2257 /* 2258 * If sending a tty stop signal to a member of an orphaned 2259 * process group, discard the signal here if the action 2260 * is default; don't stop the process below if sleeping, 2261 * and don't clear any pending SIGCONT. 2262 */ 2263 if ((prop & SIGPROP_TTYSTOP) != 0 && 2264 (p->p_pgrp->pg_flags & PGRP_ORPHANED) != 0 && 2265 action == SIG_DFL) { 2266 if (ksi && (ksi->ksi_flags & KSI_INS)) 2267 ksiginfo_tryfree(ksi); 2268 return (ret); 2269 } 2270 sigqueue_delete_proc(p, SIGCONT); 2271 if (p->p_flag & P_CONTINUED) { 2272 p->p_flag &= ~P_CONTINUED; 2273 PROC_LOCK(p->p_pptr); 2274 sigqueue_take(p->p_ksi); 2275 PROC_UNLOCK(p->p_pptr); 2276 } 2277 } 2278 2279 ret = sigqueue_add(sigqueue, sig, ksi); 2280 if (ret != 0) 2281 return (ret); 2282 signotify(td); 2283 /* 2284 * Defer further processing for signals which are held, 2285 * except that stopped processes must be continued by SIGCONT. 2286 */ 2287 if (action == SIG_HOLD && 2288 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2289 return (ret); 2290 2291 wakeup_swapper = 0; 2292 2293 /* 2294 * Some signals have a process-wide effect and a per-thread 2295 * component. Most processing occurs when the process next 2296 * tries to cross the user boundary, however there are some 2297 * times when processing needs to be done immediately, such as 2298 * waking up threads so that they can cross the user boundary. 2299 * We try to do the per-process part here. 2300 */ 2301 if (P_SHOULDSTOP(p)) { 2302 KASSERT(!(p->p_flag & P_WEXIT), 2303 ("signal to stopped but exiting process")); 2304 if (sig == SIGKILL) { 2305 /* 2306 * If traced process is already stopped, 2307 * then no further action is necessary. 2308 */ 2309 if (p->p_flag & P_TRACED) 2310 goto out; 2311 /* 2312 * SIGKILL sets process running. 2313 * It will die elsewhere. 2314 * All threads must be restarted. 2315 */ 2316 p->p_flag &= ~P_STOPPED_SIG; 2317 goto runfast; 2318 } 2319 2320 if (prop & SIGPROP_CONT) { 2321 /* 2322 * If traced process is already stopped, 2323 * then no further action is necessary. 2324 */ 2325 if (p->p_flag & P_TRACED) 2326 goto out; 2327 /* 2328 * If SIGCONT is default (or ignored), we continue the 2329 * process but don't leave the signal in sigqueue as 2330 * it has no further action. If SIGCONT is held, we 2331 * continue the process and leave the signal in 2332 * sigqueue. If the process catches SIGCONT, let it 2333 * handle the signal itself. If it isn't waiting on 2334 * an event, it goes back to run state. 2335 * Otherwise, process goes back to sleep state. 2336 */ 2337 p->p_flag &= ~P_STOPPED_SIG; 2338 PROC_SLOCK(p); 2339 if (p->p_numthreads == p->p_suspcount) { 2340 PROC_SUNLOCK(p); 2341 p->p_flag |= P_CONTINUED; 2342 p->p_xsig = SIGCONT; 2343 PROC_LOCK(p->p_pptr); 2344 childproc_continued(p); 2345 PROC_UNLOCK(p->p_pptr); 2346 PROC_SLOCK(p); 2347 } 2348 if (action == SIG_DFL) { 2349 thread_unsuspend(p); 2350 PROC_SUNLOCK(p); 2351 sigqueue_delete(sigqueue, sig); 2352 goto out_cont; 2353 } 2354 if (action == SIG_CATCH) { 2355 /* 2356 * The process wants to catch it so it needs 2357 * to run at least one thread, but which one? 2358 */ 2359 PROC_SUNLOCK(p); 2360 goto runfast; 2361 } 2362 /* 2363 * The signal is not ignored or caught. 2364 */ 2365 thread_unsuspend(p); 2366 PROC_SUNLOCK(p); 2367 goto out_cont; 2368 } 2369 2370 if (prop & SIGPROP_STOP) { 2371 /* 2372 * If traced process is already stopped, 2373 * then no further action is necessary. 2374 */ 2375 if (p->p_flag & P_TRACED) 2376 goto out; 2377 /* 2378 * Already stopped, don't need to stop again 2379 * (If we did the shell could get confused). 2380 * Just make sure the signal STOP bit set. 2381 */ 2382 p->p_flag |= P_STOPPED_SIG; 2383 sigqueue_delete(sigqueue, sig); 2384 goto out; 2385 } 2386 2387 /* 2388 * All other kinds of signals: 2389 * If a thread is sleeping interruptibly, simulate a 2390 * wakeup so that when it is continued it will be made 2391 * runnable and can look at the signal. However, don't make 2392 * the PROCESS runnable, leave it stopped. 2393 * It may run a bit until it hits a thread_suspend_check(). 2394 */ 2395 PROC_SLOCK(p); 2396 thread_lock(td); 2397 if (TD_CAN_ABORT(td)) 2398 wakeup_swapper = sig_sleepq_abort(td, intrval); 2399 else 2400 thread_unlock(td); 2401 PROC_SUNLOCK(p); 2402 goto out; 2403 /* 2404 * Mutexes are short lived. Threads waiting on them will 2405 * hit thread_suspend_check() soon. 2406 */ 2407 } else if (p->p_state == PRS_NORMAL) { 2408 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2409 tdsigwakeup(td, sig, action, intrval); 2410 goto out; 2411 } 2412 2413 MPASS(action == SIG_DFL); 2414 2415 if (prop & SIGPROP_STOP) { 2416 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2417 goto out; 2418 p->p_flag |= P_STOPPED_SIG; 2419 p->p_xsig = sig; 2420 PROC_SLOCK(p); 2421 wakeup_swapper = sig_suspend_threads(td, p, 1); 2422 if (p->p_numthreads == p->p_suspcount) { 2423 /* 2424 * only thread sending signal to another 2425 * process can reach here, if thread is sending 2426 * signal to its process, because thread does 2427 * not suspend itself here, p_numthreads 2428 * should never be equal to p_suspcount. 2429 */ 2430 thread_stopped(p); 2431 PROC_SUNLOCK(p); 2432 sigqueue_delete_proc(p, p->p_xsig); 2433 } else 2434 PROC_SUNLOCK(p); 2435 goto out; 2436 } 2437 } else { 2438 /* Not in "NORMAL" state. discard the signal. */ 2439 sigqueue_delete(sigqueue, sig); 2440 goto out; 2441 } 2442 2443 /* 2444 * The process is not stopped so we need to apply the signal to all the 2445 * running threads. 2446 */ 2447 runfast: 2448 tdsigwakeup(td, sig, action, intrval); 2449 PROC_SLOCK(p); 2450 thread_unsuspend(p); 2451 PROC_SUNLOCK(p); 2452 out_cont: 2453 itimer_proc_continue(p); 2454 kqtimer_proc_continue(p); 2455 out: 2456 /* If we jump here, proc slock should not be owned. */ 2457 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2458 if (wakeup_swapper) 2459 kick_proc0(); 2460 2461 return (ret); 2462 } 2463 2464 /* 2465 * The force of a signal has been directed against a single 2466 * thread. We need to see what we can do about knocking it 2467 * out of any sleep it may be in etc. 2468 */ 2469 static void 2470 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2471 { 2472 struct proc *p = td->td_proc; 2473 int prop, wakeup_swapper; 2474 2475 PROC_LOCK_ASSERT(p, MA_OWNED); 2476 prop = sigprop(sig); 2477 2478 PROC_SLOCK(p); 2479 thread_lock(td); 2480 /* 2481 * Bring the priority of a thread up if we want it to get 2482 * killed in this lifetime. Be careful to avoid bumping the 2483 * priority of the idle thread, since we still allow to signal 2484 * kernel processes. 2485 */ 2486 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2487 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2488 sched_prio(td, PUSER); 2489 if (TD_ON_SLEEPQ(td)) { 2490 /* 2491 * If thread is sleeping uninterruptibly 2492 * we can't interrupt the sleep... the signal will 2493 * be noticed when the process returns through 2494 * trap() or syscall(). 2495 */ 2496 if ((td->td_flags & TDF_SINTR) == 0) 2497 goto out; 2498 /* 2499 * If SIGCONT is default (or ignored) and process is 2500 * asleep, we are finished; the process should not 2501 * be awakened. 2502 */ 2503 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2504 thread_unlock(td); 2505 PROC_SUNLOCK(p); 2506 sigqueue_delete(&p->p_sigqueue, sig); 2507 /* 2508 * It may be on either list in this state. 2509 * Remove from both for now. 2510 */ 2511 sigqueue_delete(&td->td_sigqueue, sig); 2512 return; 2513 } 2514 2515 /* 2516 * Don't awaken a sleeping thread for SIGSTOP if the 2517 * STOP signal is deferred. 2518 */ 2519 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2520 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2521 goto out; 2522 2523 /* 2524 * Give low priority threads a better chance to run. 2525 */ 2526 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2527 sched_prio(td, PUSER); 2528 2529 wakeup_swapper = sig_sleepq_abort(td, intrval); 2530 PROC_SUNLOCK(p); 2531 if (wakeup_swapper) 2532 kick_proc0(); 2533 return; 2534 } 2535 2536 /* 2537 * Other states do nothing with the signal immediately, 2538 * other than kicking ourselves if we are running. 2539 * It will either never be noticed, or noticed very soon. 2540 */ 2541 #ifdef SMP 2542 if (TD_IS_RUNNING(td) && td != curthread) 2543 forward_signal(td); 2544 #endif 2545 2546 out: 2547 PROC_SUNLOCK(p); 2548 thread_unlock(td); 2549 } 2550 2551 static void 2552 ptrace_coredump(struct thread *td) 2553 { 2554 struct proc *p; 2555 struct thr_coredump_req *tcq; 2556 void *rl_cookie; 2557 2558 MPASS(td == curthread); 2559 p = td->td_proc; 2560 PROC_LOCK_ASSERT(p, MA_OWNED); 2561 if ((td->td_dbgflags & TDB_COREDUMPRQ) == 0) 2562 return; 2563 KASSERT((p->p_flag & P_STOPPED_TRACE) != 0, ("not stopped")); 2564 2565 tcq = td->td_coredump; 2566 KASSERT(tcq != NULL, ("td_coredump is NULL")); 2567 2568 if (p->p_sysent->sv_coredump == NULL) { 2569 tcq->tc_error = ENOSYS; 2570 goto wake; 2571 } 2572 2573 PROC_UNLOCK(p); 2574 rl_cookie = vn_rangelock_wlock(tcq->tc_vp, 0, OFF_MAX); 2575 2576 tcq->tc_error = p->p_sysent->sv_coredump(td, tcq->tc_vp, 2577 tcq->tc_limit, tcq->tc_flags); 2578 2579 vn_rangelock_unlock(tcq->tc_vp, rl_cookie); 2580 PROC_LOCK(p); 2581 wake: 2582 td->td_dbgflags &= ~TDB_COREDUMPRQ; 2583 td->td_coredump = NULL; 2584 wakeup(p); 2585 } 2586 2587 static int 2588 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2589 { 2590 struct thread *td2; 2591 int wakeup_swapper; 2592 2593 PROC_LOCK_ASSERT(p, MA_OWNED); 2594 PROC_SLOCK_ASSERT(p, MA_OWNED); 2595 MPASS(sending || td == curthread); 2596 2597 wakeup_swapper = 0; 2598 FOREACH_THREAD_IN_PROC(p, td2) { 2599 thread_lock(td2); 2600 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2601 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2602 (td2->td_flags & TDF_SINTR)) { 2603 if (td2->td_flags & TDF_SBDRY) { 2604 /* 2605 * Once a thread is asleep with 2606 * TDF_SBDRY and without TDF_SERESTART 2607 * or TDF_SEINTR set, it should never 2608 * become suspended due to this check. 2609 */ 2610 KASSERT(!TD_IS_SUSPENDED(td2), 2611 ("thread with deferred stops suspended")); 2612 if (TD_SBDRY_INTR(td2)) { 2613 wakeup_swapper |= sleepq_abort(td2, 2614 TD_SBDRY_ERRNO(td2)); 2615 continue; 2616 } 2617 } else if (!TD_IS_SUSPENDED(td2)) 2618 thread_suspend_one(td2); 2619 } else if (!TD_IS_SUSPENDED(td2)) { 2620 if (sending || td != td2) 2621 td2->td_flags |= TDF_ASTPENDING; 2622 #ifdef SMP 2623 if (TD_IS_RUNNING(td2) && td2 != td) 2624 forward_signal(td2); 2625 #endif 2626 } 2627 thread_unlock(td2); 2628 } 2629 return (wakeup_swapper); 2630 } 2631 2632 /* 2633 * Stop the process for an event deemed interesting to the debugger. If si is 2634 * non-NULL, this is a signal exchange; the new signal requested by the 2635 * debugger will be returned for handling. If si is NULL, this is some other 2636 * type of interesting event. The debugger may request a signal be delivered in 2637 * that case as well, however it will be deferred until it can be handled. 2638 */ 2639 int 2640 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2641 { 2642 struct proc *p = td->td_proc; 2643 struct thread *td2; 2644 ksiginfo_t ksi; 2645 2646 PROC_LOCK_ASSERT(p, MA_OWNED); 2647 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2648 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2649 &p->p_mtx.lock_object, "Stopping for traced signal"); 2650 2651 td->td_xsig = sig; 2652 2653 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2654 td->td_dbgflags |= TDB_XSIG; 2655 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2656 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2657 PROC_SLOCK(p); 2658 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2659 if (P_KILLED(p)) { 2660 /* 2661 * Ensure that, if we've been PT_KILLed, the 2662 * exit status reflects that. Another thread 2663 * may also be in ptracestop(), having just 2664 * received the SIGKILL, but this thread was 2665 * unsuspended first. 2666 */ 2667 td->td_dbgflags &= ~TDB_XSIG; 2668 td->td_xsig = SIGKILL; 2669 p->p_ptevents = 0; 2670 break; 2671 } 2672 if (p->p_flag & P_SINGLE_EXIT && 2673 !(td->td_dbgflags & TDB_EXIT)) { 2674 /* 2675 * Ignore ptrace stops except for thread exit 2676 * events when the process exits. 2677 */ 2678 td->td_dbgflags &= ~TDB_XSIG; 2679 PROC_SUNLOCK(p); 2680 return (0); 2681 } 2682 2683 /* 2684 * Make wait(2) work. Ensure that right after the 2685 * attach, the thread which was decided to become the 2686 * leader of attach gets reported to the waiter. 2687 * Otherwise, just avoid overwriting another thread's 2688 * assignment to p_xthread. If another thread has 2689 * already set p_xthread, the current thread will get 2690 * a chance to report itself upon the next iteration. 2691 */ 2692 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2693 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2694 p->p_xthread == NULL)) { 2695 p->p_xsig = sig; 2696 p->p_xthread = td; 2697 2698 /* 2699 * If we are on sleepqueue already, 2700 * let sleepqueue code decide if it 2701 * needs to go sleep after attach. 2702 */ 2703 if (td->td_wchan == NULL) 2704 td->td_dbgflags &= ~TDB_FSTP; 2705 2706 p->p_flag2 &= ~P2_PTRACE_FSTP; 2707 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2708 sig_suspend_threads(td, p, 0); 2709 } 2710 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2711 td->td_dbgflags &= ~TDB_STOPATFORK; 2712 } 2713 stopme: 2714 td->td_dbgflags |= TDB_SSWITCH; 2715 thread_suspend_switch(td, p); 2716 td->td_dbgflags &= ~TDB_SSWITCH; 2717 if ((td->td_dbgflags & TDB_COREDUMPRQ) != 0) { 2718 PROC_SUNLOCK(p); 2719 ptrace_coredump(td); 2720 PROC_SLOCK(p); 2721 goto stopme; 2722 } 2723 if (p->p_xthread == td) 2724 p->p_xthread = NULL; 2725 if (!(p->p_flag & P_TRACED)) 2726 break; 2727 if (td->td_dbgflags & TDB_SUSPEND) { 2728 if (p->p_flag & P_SINGLE_EXIT) 2729 break; 2730 goto stopme; 2731 } 2732 } 2733 PROC_SUNLOCK(p); 2734 } 2735 2736 if (si != NULL && sig == td->td_xsig) { 2737 /* Parent wants us to take the original signal unchanged. */ 2738 si->ksi_flags |= KSI_HEAD; 2739 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2740 si->ksi_signo = 0; 2741 } else if (td->td_xsig != 0) { 2742 /* 2743 * If parent wants us to take a new signal, then it will leave 2744 * it in td->td_xsig; otherwise we just look for signals again. 2745 */ 2746 ksiginfo_init(&ksi); 2747 ksi.ksi_signo = td->td_xsig; 2748 ksi.ksi_flags |= KSI_PTRACE; 2749 td2 = sigtd(p, td->td_xsig, false); 2750 tdsendsignal(p, td2, td->td_xsig, &ksi); 2751 if (td != td2) 2752 return (0); 2753 } 2754 2755 return (td->td_xsig); 2756 } 2757 2758 static void 2759 reschedule_signals(struct proc *p, sigset_t block, int flags) 2760 { 2761 struct sigacts *ps; 2762 struct thread *td; 2763 int sig; 2764 bool fastblk, pslocked; 2765 2766 PROC_LOCK_ASSERT(p, MA_OWNED); 2767 ps = p->p_sigacts; 2768 pslocked = (flags & SIGPROCMASK_PS_LOCKED) != 0; 2769 mtx_assert(&ps->ps_mtx, pslocked ? MA_OWNED : MA_NOTOWNED); 2770 if (SIGISEMPTY(p->p_siglist)) 2771 return; 2772 SIGSETAND(block, p->p_siglist); 2773 fastblk = (flags & SIGPROCMASK_FASTBLK) != 0; 2774 SIG_FOREACH(sig, &block) { 2775 td = sigtd(p, sig, fastblk); 2776 2777 /* 2778 * If sigtd() selected us despite sigfastblock is 2779 * blocking, do not activate AST or wake us, to avoid 2780 * loop in AST handler. 2781 */ 2782 if (fastblk && td == curthread) 2783 continue; 2784 2785 signotify(td); 2786 if (!pslocked) 2787 mtx_lock(&ps->ps_mtx); 2788 if (p->p_flag & P_TRACED || 2789 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2790 !SIGISMEMBER(td->td_sigmask, sig))) { 2791 tdsigwakeup(td, sig, SIG_CATCH, 2792 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2793 ERESTART)); 2794 } 2795 if (!pslocked) 2796 mtx_unlock(&ps->ps_mtx); 2797 } 2798 } 2799 2800 void 2801 tdsigcleanup(struct thread *td) 2802 { 2803 struct proc *p; 2804 sigset_t unblocked; 2805 2806 p = td->td_proc; 2807 PROC_LOCK_ASSERT(p, MA_OWNED); 2808 2809 sigqueue_flush(&td->td_sigqueue); 2810 if (p->p_numthreads == 1) 2811 return; 2812 2813 /* 2814 * Since we cannot handle signals, notify signal post code 2815 * about this by filling the sigmask. 2816 * 2817 * Also, if needed, wake up thread(s) that do not block the 2818 * same signals as the exiting thread, since the thread might 2819 * have been selected for delivery and woken up. 2820 */ 2821 SIGFILLSET(unblocked); 2822 SIGSETNAND(unblocked, td->td_sigmask); 2823 SIGFILLSET(td->td_sigmask); 2824 reschedule_signals(p, unblocked, 0); 2825 2826 } 2827 2828 static int 2829 sigdeferstop_curr_flags(int cflags) 2830 { 2831 2832 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2833 (cflags & TDF_SBDRY) != 0); 2834 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2835 } 2836 2837 /* 2838 * Defer the delivery of SIGSTOP for the current thread, according to 2839 * the requested mode. Returns previous flags, which must be restored 2840 * by sigallowstop(). 2841 * 2842 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2843 * cleared by the current thread, which allow the lock-less read-only 2844 * accesses below. 2845 */ 2846 int 2847 sigdeferstop_impl(int mode) 2848 { 2849 struct thread *td; 2850 int cflags, nflags; 2851 2852 td = curthread; 2853 cflags = sigdeferstop_curr_flags(td->td_flags); 2854 switch (mode) { 2855 case SIGDEFERSTOP_NOP: 2856 nflags = cflags; 2857 break; 2858 case SIGDEFERSTOP_OFF: 2859 nflags = 0; 2860 break; 2861 case SIGDEFERSTOP_SILENT: 2862 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2863 break; 2864 case SIGDEFERSTOP_EINTR: 2865 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2866 break; 2867 case SIGDEFERSTOP_ERESTART: 2868 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2869 break; 2870 default: 2871 panic("sigdeferstop: invalid mode %x", mode); 2872 break; 2873 } 2874 if (cflags == nflags) 2875 return (SIGDEFERSTOP_VAL_NCHG); 2876 thread_lock(td); 2877 td->td_flags = (td->td_flags & ~cflags) | nflags; 2878 thread_unlock(td); 2879 return (cflags); 2880 } 2881 2882 /* 2883 * Restores the STOP handling mode, typically permitting the delivery 2884 * of SIGSTOP for the current thread. This does not immediately 2885 * suspend if a stop was posted. Instead, the thread will suspend 2886 * either via ast() or a subsequent interruptible sleep. 2887 */ 2888 void 2889 sigallowstop_impl(int prev) 2890 { 2891 struct thread *td; 2892 int cflags; 2893 2894 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2895 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2896 ("sigallowstop: incorrect previous mode %x", prev)); 2897 td = curthread; 2898 cflags = sigdeferstop_curr_flags(td->td_flags); 2899 if (cflags != prev) { 2900 thread_lock(td); 2901 td->td_flags = (td->td_flags & ~cflags) | prev; 2902 thread_unlock(td); 2903 } 2904 } 2905 2906 enum sigstatus { 2907 SIGSTATUS_HANDLE, 2908 SIGSTATUS_HANDLED, 2909 SIGSTATUS_IGNORE, 2910 SIGSTATUS_SBDRY_STOP, 2911 }; 2912 2913 /* 2914 * The thread has signal "sig" pending. Figure out what to do with it: 2915 * 2916 * _HANDLE -> the caller should handle the signal 2917 * _HANDLED -> handled internally, reload pending signal set 2918 * _IGNORE -> ignored, remove from the set of pending signals and try the 2919 * next pending signal 2920 * _SBDRY_STOP -> the signal should stop the thread but this is not 2921 * permitted in the current context 2922 */ 2923 static enum sigstatus 2924 sigprocess(struct thread *td, int sig) 2925 { 2926 struct proc *p; 2927 struct sigacts *ps; 2928 struct sigqueue *queue; 2929 ksiginfo_t ksi; 2930 int prop; 2931 2932 KASSERT(_SIG_VALID(sig), ("%s: invalid signal %d", __func__, sig)); 2933 2934 p = td->td_proc; 2935 ps = p->p_sigacts; 2936 mtx_assert(&ps->ps_mtx, MA_OWNED); 2937 PROC_LOCK_ASSERT(p, MA_OWNED); 2938 2939 /* 2940 * We should allow pending but ignored signals below 2941 * only if there is sigwait() active, or P_TRACED was 2942 * on when they were posted. 2943 */ 2944 if (SIGISMEMBER(ps->ps_sigignore, sig) && 2945 (p->p_flag & P_TRACED) == 0 && 2946 (td->td_flags & TDF_SIGWAIT) == 0) { 2947 return (SIGSTATUS_IGNORE); 2948 } 2949 2950 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2951 /* 2952 * If traced, always stop. 2953 * Remove old signal from queue before the stop. 2954 * XXX shrug off debugger, it causes siginfo to 2955 * be thrown away. 2956 */ 2957 queue = &td->td_sigqueue; 2958 ksiginfo_init(&ksi); 2959 if (sigqueue_get(queue, sig, &ksi) == 0) { 2960 queue = &p->p_sigqueue; 2961 sigqueue_get(queue, sig, &ksi); 2962 } 2963 td->td_si = ksi.ksi_info; 2964 2965 mtx_unlock(&ps->ps_mtx); 2966 sig = ptracestop(td, sig, &ksi); 2967 mtx_lock(&ps->ps_mtx); 2968 2969 td->td_si.si_signo = 0; 2970 2971 /* 2972 * Keep looking if the debugger discarded or 2973 * replaced the signal. 2974 */ 2975 if (sig == 0) 2976 return (SIGSTATUS_HANDLED); 2977 2978 /* 2979 * If the signal became masked, re-queue it. 2980 */ 2981 if (SIGISMEMBER(td->td_sigmask, sig)) { 2982 ksi.ksi_flags |= KSI_HEAD; 2983 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2984 return (SIGSTATUS_HANDLED); 2985 } 2986 2987 /* 2988 * If the traced bit got turned off, requeue the signal and 2989 * reload the set of pending signals. This ensures that p_sig* 2990 * and p_sigact are consistent. 2991 */ 2992 if ((p->p_flag & P_TRACED) == 0) { 2993 if ((ksi.ksi_flags & KSI_PTRACE) == 0) { 2994 ksi.ksi_flags |= KSI_HEAD; 2995 sigqueue_add(queue, sig, &ksi); 2996 } 2997 return (SIGSTATUS_HANDLED); 2998 } 2999 } 3000 3001 /* 3002 * Decide whether the signal should be returned. 3003 * Return the signal's number, or fall through 3004 * to clear it from the pending mask. 3005 */ 3006 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 3007 case (intptr_t)SIG_DFL: 3008 /* 3009 * Don't take default actions on system processes. 3010 */ 3011 if (p->p_pid <= 1) { 3012 #ifdef DIAGNOSTIC 3013 /* 3014 * Are you sure you want to ignore SIGSEGV 3015 * in init? XXX 3016 */ 3017 printf("Process (pid %lu) got signal %d\n", 3018 (u_long)p->p_pid, sig); 3019 #endif 3020 return (SIGSTATUS_IGNORE); 3021 } 3022 3023 /* 3024 * If there is a pending stop signal to process with 3025 * default action, stop here, then clear the signal. 3026 * Traced or exiting processes should ignore stops. 3027 * Additionally, a member of an orphaned process group 3028 * should ignore tty stops. 3029 */ 3030 prop = sigprop(sig); 3031 if (prop & SIGPROP_STOP) { 3032 mtx_unlock(&ps->ps_mtx); 3033 if ((p->p_flag & (P_TRACED | P_WEXIT | 3034 P_SINGLE_EXIT)) != 0 || ((p->p_pgrp-> 3035 pg_flags & PGRP_ORPHANED) != 0 && 3036 (prop & SIGPROP_TTYSTOP) != 0)) { 3037 mtx_lock(&ps->ps_mtx); 3038 return (SIGSTATUS_IGNORE); 3039 } 3040 if (TD_SBDRY_INTR(td)) { 3041 KASSERT((td->td_flags & TDF_SBDRY) != 0, 3042 ("lost TDF_SBDRY")); 3043 mtx_lock(&ps->ps_mtx); 3044 return (SIGSTATUS_SBDRY_STOP); 3045 } 3046 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 3047 &p->p_mtx.lock_object, "Catching SIGSTOP"); 3048 sigqueue_delete(&td->td_sigqueue, sig); 3049 sigqueue_delete(&p->p_sigqueue, sig); 3050 p->p_flag |= P_STOPPED_SIG; 3051 p->p_xsig = sig; 3052 PROC_SLOCK(p); 3053 sig_suspend_threads(td, p, 0); 3054 thread_suspend_switch(td, p); 3055 PROC_SUNLOCK(p); 3056 mtx_lock(&ps->ps_mtx); 3057 return (SIGSTATUS_HANDLED); 3058 } else if ((prop & SIGPROP_IGNORE) != 0 && 3059 (td->td_flags & TDF_SIGWAIT) == 0) { 3060 /* 3061 * Default action is to ignore; drop it if 3062 * not in kern_sigtimedwait(). 3063 */ 3064 return (SIGSTATUS_IGNORE); 3065 } else { 3066 return (SIGSTATUS_HANDLE); 3067 } 3068 3069 case (intptr_t)SIG_IGN: 3070 if ((td->td_flags & TDF_SIGWAIT) == 0) 3071 return (SIGSTATUS_IGNORE); 3072 else 3073 return (SIGSTATUS_HANDLE); 3074 3075 default: 3076 /* 3077 * This signal has an action, let postsig() process it. 3078 */ 3079 return (SIGSTATUS_HANDLE); 3080 } 3081 } 3082 3083 /* 3084 * If the current process has received a signal (should be caught or cause 3085 * termination, should interrupt current syscall), return the signal number. 3086 * Stop signals with default action are processed immediately, then cleared; 3087 * they aren't returned. This is checked after each entry to the system for 3088 * a syscall or trap (though this can usually be done without calling 3089 * issignal by checking the pending signal masks in cursig.) The normal call 3090 * sequence is 3091 * 3092 * while (sig = cursig(curthread)) 3093 * postsig(sig); 3094 */ 3095 static int 3096 issignal(struct thread *td) 3097 { 3098 struct proc *p; 3099 sigset_t sigpending; 3100 int sig; 3101 3102 p = td->td_proc; 3103 PROC_LOCK_ASSERT(p, MA_OWNED); 3104 3105 for (;;) { 3106 sigpending = td->td_sigqueue.sq_signals; 3107 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 3108 SIGSETNAND(sigpending, td->td_sigmask); 3109 3110 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 3111 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 3112 SIG_STOPSIGMASK(sigpending); 3113 if (SIGISEMPTY(sigpending)) /* no signal to send */ 3114 return (0); 3115 3116 /* 3117 * Do fast sigblock if requested by usermode. Since 3118 * we do know that there was a signal pending at this 3119 * point, set the FAST_SIGBLOCK_PEND as indicator for 3120 * usermode to perform a dummy call to 3121 * FAST_SIGBLOCK_UNBLOCK, which causes immediate 3122 * delivery of postponed pending signal. 3123 */ 3124 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 3125 if (td->td_sigblock_val != 0) 3126 SIGSETNAND(sigpending, fastblock_mask); 3127 if (SIGISEMPTY(sigpending)) { 3128 td->td_pflags |= TDP_SIGFASTPENDING; 3129 return (0); 3130 } 3131 } 3132 3133 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 3134 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 3135 SIGISMEMBER(sigpending, SIGSTOP)) { 3136 /* 3137 * If debugger just attached, always consume 3138 * SIGSTOP from ptrace(PT_ATTACH) first, to 3139 * execute the debugger attach ritual in 3140 * order. 3141 */ 3142 td->td_dbgflags |= TDB_FSTP; 3143 SIGEMPTYSET(sigpending); 3144 SIGADDSET(sigpending, SIGSTOP); 3145 } 3146 3147 SIG_FOREACH(sig, &sigpending) { 3148 switch (sigprocess(td, sig)) { 3149 case SIGSTATUS_HANDLE: 3150 return (sig); 3151 case SIGSTATUS_HANDLED: 3152 goto next; 3153 case SIGSTATUS_IGNORE: 3154 sigqueue_delete(&td->td_sigqueue, sig); 3155 sigqueue_delete(&p->p_sigqueue, sig); 3156 break; 3157 case SIGSTATUS_SBDRY_STOP: 3158 return (-1); 3159 } 3160 } 3161 next:; 3162 } 3163 } 3164 3165 void 3166 thread_stopped(struct proc *p) 3167 { 3168 int n; 3169 3170 PROC_LOCK_ASSERT(p, MA_OWNED); 3171 PROC_SLOCK_ASSERT(p, MA_OWNED); 3172 n = p->p_suspcount; 3173 if (p == curproc) 3174 n++; 3175 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 3176 PROC_SUNLOCK(p); 3177 p->p_flag &= ~P_WAITED; 3178 PROC_LOCK(p->p_pptr); 3179 childproc_stopped(p, (p->p_flag & P_TRACED) ? 3180 CLD_TRAPPED : CLD_STOPPED); 3181 PROC_UNLOCK(p->p_pptr); 3182 PROC_SLOCK(p); 3183 } 3184 } 3185 3186 /* 3187 * Take the action for the specified signal 3188 * from the current set of pending signals. 3189 */ 3190 int 3191 postsig(int sig) 3192 { 3193 struct thread *td; 3194 struct proc *p; 3195 struct sigacts *ps; 3196 sig_t action; 3197 ksiginfo_t ksi; 3198 sigset_t returnmask; 3199 3200 KASSERT(sig != 0, ("postsig")); 3201 3202 td = curthread; 3203 p = td->td_proc; 3204 PROC_LOCK_ASSERT(p, MA_OWNED); 3205 ps = p->p_sigacts; 3206 mtx_assert(&ps->ps_mtx, MA_OWNED); 3207 ksiginfo_init(&ksi); 3208 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3209 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3210 return (0); 3211 ksi.ksi_signo = sig; 3212 if (ksi.ksi_code == SI_TIMER) 3213 itimer_accept(p, ksi.ksi_timerid, &ksi); 3214 action = ps->ps_sigact[_SIG_IDX(sig)]; 3215 #ifdef KTRACE 3216 if (KTRPOINT(td, KTR_PSIG)) 3217 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3218 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3219 #endif 3220 3221 if (action == SIG_DFL) { 3222 /* 3223 * Default action, where the default is to kill 3224 * the process. (Other cases were ignored above.) 3225 */ 3226 mtx_unlock(&ps->ps_mtx); 3227 proc_td_siginfo_capture(td, &ksi.ksi_info); 3228 sigexit(td, sig); 3229 /* NOTREACHED */ 3230 } else { 3231 /* 3232 * If we get here, the signal must be caught. 3233 */ 3234 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3235 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3236 ("postsig action: blocked sig %d", sig)); 3237 3238 /* 3239 * Set the new mask value and also defer further 3240 * occurrences of this signal. 3241 * 3242 * Special case: user has done a sigsuspend. Here the 3243 * current mask is not of interest, but rather the 3244 * mask from before the sigsuspend is what we want 3245 * restored after the signal processing is completed. 3246 */ 3247 if (td->td_pflags & TDP_OLDMASK) { 3248 returnmask = td->td_oldsigmask; 3249 td->td_pflags &= ~TDP_OLDMASK; 3250 } else 3251 returnmask = td->td_sigmask; 3252 3253 if (p->p_sig == sig) { 3254 p->p_sig = 0; 3255 } 3256 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3257 postsig_done(sig, td, ps); 3258 } 3259 return (1); 3260 } 3261 3262 int 3263 sig_ast_checksusp(struct thread *td) 3264 { 3265 struct proc *p __diagused; 3266 int ret; 3267 3268 p = td->td_proc; 3269 PROC_LOCK_ASSERT(p, MA_OWNED); 3270 3271 if ((td->td_flags & TDF_NEEDSUSPCHK) == 0) 3272 return (0); 3273 3274 ret = thread_suspend_check(1); 3275 MPASS(ret == 0 || ret == EINTR || ret == ERESTART); 3276 return (ret); 3277 } 3278 3279 int 3280 sig_ast_needsigchk(struct thread *td) 3281 { 3282 struct proc *p; 3283 struct sigacts *ps; 3284 int ret, sig; 3285 3286 p = td->td_proc; 3287 PROC_LOCK_ASSERT(p, MA_OWNED); 3288 3289 if ((td->td_flags & TDF_NEEDSIGCHK) == 0) 3290 return (0); 3291 3292 ps = p->p_sigacts; 3293 mtx_lock(&ps->ps_mtx); 3294 sig = cursig(td); 3295 if (sig == -1) { 3296 mtx_unlock(&ps->ps_mtx); 3297 KASSERT((td->td_flags & TDF_SBDRY) != 0, ("lost TDF_SBDRY")); 3298 KASSERT(TD_SBDRY_INTR(td), 3299 ("lost TDF_SERESTART of TDF_SEINTR")); 3300 KASSERT((td->td_flags & (TDF_SEINTR | TDF_SERESTART)) != 3301 (TDF_SEINTR | TDF_SERESTART), 3302 ("both TDF_SEINTR and TDF_SERESTART")); 3303 ret = TD_SBDRY_ERRNO(td); 3304 } else if (sig != 0) { 3305 ret = SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : ERESTART; 3306 mtx_unlock(&ps->ps_mtx); 3307 } else { 3308 mtx_unlock(&ps->ps_mtx); 3309 ret = 0; 3310 } 3311 3312 /* 3313 * Do not go into sleep if this thread was the ptrace(2) 3314 * attach leader. cursig() consumed SIGSTOP from PT_ATTACH, 3315 * but we usually act on the signal by interrupting sleep, and 3316 * should do that here as well. 3317 */ 3318 if ((td->td_dbgflags & TDB_FSTP) != 0) { 3319 if (ret == 0) 3320 ret = EINTR; 3321 td->td_dbgflags &= ~TDB_FSTP; 3322 } 3323 3324 return (ret); 3325 } 3326 3327 int 3328 sig_intr(void) 3329 { 3330 struct thread *td; 3331 struct proc *p; 3332 int ret; 3333 3334 td = curthread; 3335 if ((td->td_flags & (TDF_NEEDSIGCHK | TDF_NEEDSUSPCHK)) == 0) 3336 return (0); 3337 3338 p = td->td_proc; 3339 3340 PROC_LOCK(p); 3341 ret = sig_ast_checksusp(td); 3342 if (ret == 0) 3343 ret = sig_ast_needsigchk(td); 3344 PROC_UNLOCK(p); 3345 return (ret); 3346 } 3347 3348 bool 3349 curproc_sigkilled(void) 3350 { 3351 struct thread *td; 3352 struct proc *p; 3353 struct sigacts *ps; 3354 bool res; 3355 3356 td = curthread; 3357 if ((td->td_flags & TDF_NEEDSIGCHK) == 0) 3358 return (false); 3359 3360 p = td->td_proc; 3361 PROC_LOCK(p); 3362 ps = p->p_sigacts; 3363 mtx_lock(&ps->ps_mtx); 3364 res = SIGISMEMBER(td->td_sigqueue.sq_signals, SIGKILL) || 3365 SIGISMEMBER(p->p_sigqueue.sq_signals, SIGKILL); 3366 mtx_unlock(&ps->ps_mtx); 3367 PROC_UNLOCK(p); 3368 return (res); 3369 } 3370 3371 void 3372 proc_wkilled(struct proc *p) 3373 { 3374 3375 PROC_LOCK_ASSERT(p, MA_OWNED); 3376 if ((p->p_flag & P_WKILLED) == 0) { 3377 p->p_flag |= P_WKILLED; 3378 /* 3379 * Notify swapper that there is a process to swap in. 3380 * The notification is racy, at worst it would take 10 3381 * seconds for the swapper process to notice. 3382 */ 3383 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3384 wakeup(&proc0); 3385 } 3386 } 3387 3388 /* 3389 * Kill the current process for stated reason. 3390 */ 3391 void 3392 killproc(struct proc *p, const char *why) 3393 { 3394 3395 PROC_LOCK_ASSERT(p, MA_OWNED); 3396 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3397 p->p_comm); 3398 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3399 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3400 p->p_ucred->cr_uid, why); 3401 proc_wkilled(p); 3402 kern_psignal(p, SIGKILL); 3403 } 3404 3405 /* 3406 * Force the current process to exit with the specified signal, dumping core 3407 * if appropriate. We bypass the normal tests for masked and caught signals, 3408 * allowing unrecoverable failures to terminate the process without changing 3409 * signal state. Mark the accounting record with the signal termination. 3410 * If dumping core, save the signal number for the debugger. Calls exit and 3411 * does not return. 3412 */ 3413 void 3414 sigexit(struct thread *td, int sig) 3415 { 3416 struct proc *p = td->td_proc; 3417 3418 PROC_LOCK_ASSERT(p, MA_OWNED); 3419 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_PNBUF(&nd); 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_PNBUF(&nd); 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