Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_sig.c
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1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/ctype.h> 46 #include <sys/systm.h> 47 #include <sys/signalvar.h> 48 #include <sys/vnode.h> 49 #include <sys/acct.h> 50 #include <sys/capsicum.h> 51 #include <sys/compressor.h> 52 #include <sys/condvar.h> 53 #include <sys/devctl.h> 54 #include <sys/event.h> 55 #include <sys/fcntl.h> 56 #include <sys/imgact.h> 57 #include <sys/kernel.h> 58 #include <sys/ktr.h> 59 #include <sys/ktrace.h> 60 #include <sys/limits.h> 61 #include <sys/lock.h> 62 #include <sys/malloc.h> 63 #include <sys/mutex.h> 64 #include <sys/refcount.h> 65 #include <sys/namei.h> 66 #include <sys/proc.h> 67 #include <sys/procdesc.h> 68 #include <sys/ptrace.h> 69 #include <sys/posix4.h> 70 #include <sys/racct.h> 71 #include <sys/resourcevar.h> 72 #include <sys/sdt.h> 73 #include <sys/sbuf.h> 74 #include <sys/sleepqueue.h> 75 #include <sys/smp.h> 76 #include <sys/stat.h> 77 #include <sys/sx.h> 78 #include <sys/syscallsubr.h> 79 #include <sys/sysctl.h> 80 #include <sys/sysent.h> 81 #include <sys/syslog.h> 82 #include <sys/sysproto.h> 83 #include <sys/timers.h> 84 #include <sys/unistd.h> 85 #include <sys/wait.h> 86 #include <vm/vm.h> 87 #include <vm/vm_extern.h> 88 #include <vm/uma.h> 89 90 #include <sys/jail.h> 91 92 #include <machine/cpu.h> 93 94 #include <security/audit/audit.h> 95 96 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 97 98 SDT_PROVIDER_DECLARE(proc); 99 SDT_PROBE_DEFINE3(proc, , , signal__send, 100 "struct thread *", "struct proc *", "int"); 101 SDT_PROBE_DEFINE2(proc, , , signal__clear, 102 "int", "ksiginfo_t *"); 103 SDT_PROBE_DEFINE3(proc, , , signal__discard, 104 "struct thread *", "struct proc *", "int"); 105 106 static int coredump(struct thread *); 107 static int killpg1(struct thread *td, int sig, int pgid, int all, 108 ksiginfo_t *ksi); 109 static int issignal(struct thread *td); 110 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 111 static int sigprop(int sig); 112 static void tdsigwakeup(struct thread *, int, sig_t, int); 113 static int sig_suspend_threads(struct thread *, struct proc *, int); 114 static int filt_sigattach(struct knote *kn); 115 static void filt_sigdetach(struct knote *kn); 116 static int filt_signal(struct knote *kn, long hint); 117 static struct thread *sigtd(struct proc *p, int sig, bool fast_sigblock); 118 static void sigqueue_start(void); 119 120 static uma_zone_t ksiginfo_zone = NULL; 121 struct filterops sig_filtops = { 122 .f_isfd = 0, 123 .f_attach = filt_sigattach, 124 .f_detach = filt_sigdetach, 125 .f_event = filt_signal, 126 }; 127 128 static int kern_logsigexit = 1; 129 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 130 &kern_logsigexit, 0, 131 "Log processes quitting on abnormal signals to syslog(3)"); 132 133 static int kern_forcesigexit = 1; 134 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 135 &kern_forcesigexit, 0, "Force trap signal to be handled"); 136 137 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 138 "POSIX real time signal"); 139 140 static int max_pending_per_proc = 128; 141 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 142 &max_pending_per_proc, 0, "Max pending signals per proc"); 143 144 static int preallocate_siginfo = 1024; 145 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 146 &preallocate_siginfo, 0, "Preallocated signal memory size"); 147 148 static int signal_overflow = 0; 149 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 150 &signal_overflow, 0, "Number of signals overflew"); 151 152 static int signal_alloc_fail = 0; 153 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 154 &signal_alloc_fail, 0, "signals failed to be allocated"); 155 156 static int kern_lognosys = 0; 157 SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 158 "Log invalid syscalls"); 159 160 __read_frequently bool sigfastblock_fetch_always = false; 161 SYSCTL_BOOL(_kern, OID_AUTO, sigfastblock_fetch_always, CTLFLAG_RWTUN, 162 &sigfastblock_fetch_always, 0, 163 "Fetch sigfastblock word on each syscall entry for proper " 164 "blocking semantic"); 165 166 static bool kern_sig_discard_ign = true; 167 SYSCTL_BOOL(_kern, OID_AUTO, sig_discard_ign, CTLFLAG_RWTUN, 168 &kern_sig_discard_ign, 0, 169 "Discard ignored signals on delivery, otherwise queue them to " 170 "the target queue"); 171 172 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 173 174 /* 175 * Policy -- Can ucred cr1 send SIGIO to process cr2? 176 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 177 * in the right situations. 178 */ 179 #define CANSIGIO(cr1, cr2) \ 180 ((cr1)->cr_uid == 0 || \ 181 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 182 (cr1)->cr_uid == (cr2)->cr_ruid || \ 183 (cr1)->cr_ruid == (cr2)->cr_uid || \ 184 (cr1)->cr_uid == (cr2)->cr_uid) 185 186 static int sugid_coredump; 187 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 188 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 189 190 static int capmode_coredump; 191 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 192 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 193 194 static int do_coredump = 1; 195 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 196 &do_coredump, 0, "Enable/Disable coredumps"); 197 198 static int set_core_nodump_flag = 0; 199 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 200 0, "Enable setting the NODUMP flag on coredump files"); 201 202 static int coredump_devctl = 0; 203 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 204 0, "Generate a devctl notification when processes coredump"); 205 206 /* 207 * Signal properties and actions. 208 * The array below categorizes the signals and their default actions 209 * according to the following properties: 210 */ 211 #define SIGPROP_KILL 0x01 /* terminates process by default */ 212 #define SIGPROP_CORE 0x02 /* ditto and coredumps */ 213 #define SIGPROP_STOP 0x04 /* suspend process */ 214 #define SIGPROP_TTYSTOP 0x08 /* ditto, from tty */ 215 #define SIGPROP_IGNORE 0x10 /* ignore by default */ 216 #define SIGPROP_CONT 0x20 /* continue if suspended */ 217 218 static int sigproptbl[NSIG] = { 219 [SIGHUP] = SIGPROP_KILL, 220 [SIGINT] = SIGPROP_KILL, 221 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE, 222 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE, 223 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE, 224 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE, 225 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE, 226 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE, 227 [SIGKILL] = SIGPROP_KILL, 228 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE, 229 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE, 230 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE, 231 [SIGPIPE] = SIGPROP_KILL, 232 [SIGALRM] = SIGPROP_KILL, 233 [SIGTERM] = SIGPROP_KILL, 234 [SIGURG] = SIGPROP_IGNORE, 235 [SIGSTOP] = SIGPROP_STOP, 236 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP, 237 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT, 238 [SIGCHLD] = SIGPROP_IGNORE, 239 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP, 240 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP, 241 [SIGIO] = SIGPROP_IGNORE, 242 [SIGXCPU] = SIGPROP_KILL, 243 [SIGXFSZ] = SIGPROP_KILL, 244 [SIGVTALRM] = SIGPROP_KILL, 245 [SIGPROF] = SIGPROP_KILL, 246 [SIGWINCH] = SIGPROP_IGNORE, 247 [SIGINFO] = SIGPROP_IGNORE, 248 [SIGUSR1] = SIGPROP_KILL, 249 [SIGUSR2] = SIGPROP_KILL, 250 }; 251 252 #define _SIG_FOREACH_ADVANCE(i, set) ({ \ 253 int __found; \ 254 for (;;) { \ 255 if (__bits != 0) { \ 256 int __sig = ffs(__bits); \ 257 __bits &= ~(1u << (__sig - 1)); \ 258 sig = __i * sizeof((set)->__bits[0]) * NBBY + __sig; \ 259 __found = 1; \ 260 break; \ 261 } \ 262 if (++__i == _SIG_WORDS) { \ 263 __found = 0; \ 264 break; \ 265 } \ 266 __bits = (set)->__bits[__i]; \ 267 } \ 268 __found != 0; \ 269 }) 270 271 #define SIG_FOREACH(i, set) \ 272 for (int32_t __i = -1, __bits = 0; \ 273 _SIG_FOREACH_ADVANCE(i, set); ) \ 274 275 sigset_t fastblock_mask; 276 277 static void 278 sigqueue_start(void) 279 { 280 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 281 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 282 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 283 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 284 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 285 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 286 SIGFILLSET(fastblock_mask); 287 SIG_CANTMASK(fastblock_mask); 288 } 289 290 ksiginfo_t * 291 ksiginfo_alloc(int wait) 292 { 293 int flags; 294 295 flags = M_ZERO; 296 if (! wait) 297 flags |= M_NOWAIT; 298 if (ksiginfo_zone != NULL) 299 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 300 return (NULL); 301 } 302 303 void 304 ksiginfo_free(ksiginfo_t *ksi) 305 { 306 uma_zfree(ksiginfo_zone, ksi); 307 } 308 309 static __inline int 310 ksiginfo_tryfree(ksiginfo_t *ksi) 311 { 312 if (!(ksi->ksi_flags & KSI_EXT)) { 313 uma_zfree(ksiginfo_zone, ksi); 314 return (1); 315 } 316 return (0); 317 } 318 319 void 320 sigqueue_init(sigqueue_t *list, struct proc *p) 321 { 322 SIGEMPTYSET(list->sq_signals); 323 SIGEMPTYSET(list->sq_kill); 324 SIGEMPTYSET(list->sq_ptrace); 325 TAILQ_INIT(&list->sq_list); 326 list->sq_proc = p; 327 list->sq_flags = SQ_INIT; 328 } 329 330 /* 331 * Get a signal's ksiginfo. 332 * Return: 333 * 0 - signal not found 334 * others - signal number 335 */ 336 static int 337 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 338 { 339 struct proc *p = sq->sq_proc; 340 struct ksiginfo *ksi, *next; 341 int count = 0; 342 343 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 344 345 if (!SIGISMEMBER(sq->sq_signals, signo)) 346 return (0); 347 348 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 349 count++; 350 SIGDELSET(sq->sq_ptrace, signo); 351 si->ksi_flags |= KSI_PTRACE; 352 } 353 if (SIGISMEMBER(sq->sq_kill, signo)) { 354 count++; 355 if (count == 1) 356 SIGDELSET(sq->sq_kill, signo); 357 } 358 359 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 360 if (ksi->ksi_signo == signo) { 361 if (count == 0) { 362 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 363 ksi->ksi_sigq = NULL; 364 ksiginfo_copy(ksi, si); 365 if (ksiginfo_tryfree(ksi) && p != NULL) 366 p->p_pendingcnt--; 367 } 368 if (++count > 1) 369 break; 370 } 371 } 372 373 if (count <= 1) 374 SIGDELSET(sq->sq_signals, signo); 375 si->ksi_signo = signo; 376 return (signo); 377 } 378 379 void 380 sigqueue_take(ksiginfo_t *ksi) 381 { 382 struct ksiginfo *kp; 383 struct proc *p; 384 sigqueue_t *sq; 385 386 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 387 return; 388 389 p = sq->sq_proc; 390 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 391 ksi->ksi_sigq = NULL; 392 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 393 p->p_pendingcnt--; 394 395 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 396 kp = TAILQ_NEXT(kp, ksi_link)) { 397 if (kp->ksi_signo == ksi->ksi_signo) 398 break; 399 } 400 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 401 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 402 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 403 } 404 405 static int 406 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 407 { 408 struct proc *p = sq->sq_proc; 409 struct ksiginfo *ksi; 410 int ret = 0; 411 412 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 413 414 /* 415 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 416 * for these signals. 417 */ 418 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 419 SIGADDSET(sq->sq_kill, signo); 420 goto out_set_bit; 421 } 422 423 /* directly insert the ksi, don't copy it */ 424 if (si->ksi_flags & KSI_INS) { 425 if (si->ksi_flags & KSI_HEAD) 426 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 427 else 428 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 429 si->ksi_sigq = sq; 430 goto out_set_bit; 431 } 432 433 if (__predict_false(ksiginfo_zone == NULL)) { 434 SIGADDSET(sq->sq_kill, signo); 435 goto out_set_bit; 436 } 437 438 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 439 signal_overflow++; 440 ret = EAGAIN; 441 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 442 signal_alloc_fail++; 443 ret = EAGAIN; 444 } else { 445 if (p != NULL) 446 p->p_pendingcnt++; 447 ksiginfo_copy(si, ksi); 448 ksi->ksi_signo = signo; 449 if (si->ksi_flags & KSI_HEAD) 450 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 451 else 452 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 453 ksi->ksi_sigq = sq; 454 } 455 456 if (ret != 0) { 457 if ((si->ksi_flags & KSI_PTRACE) != 0) { 458 SIGADDSET(sq->sq_ptrace, signo); 459 ret = 0; 460 goto out_set_bit; 461 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 462 (si->ksi_flags & KSI_SIGQ) == 0) { 463 SIGADDSET(sq->sq_kill, signo); 464 ret = 0; 465 goto out_set_bit; 466 } 467 return (ret); 468 } 469 470 out_set_bit: 471 SIGADDSET(sq->sq_signals, signo); 472 return (ret); 473 } 474 475 void 476 sigqueue_flush(sigqueue_t *sq) 477 { 478 struct proc *p = sq->sq_proc; 479 ksiginfo_t *ksi; 480 481 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 482 483 if (p != NULL) 484 PROC_LOCK_ASSERT(p, MA_OWNED); 485 486 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 487 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 488 ksi->ksi_sigq = NULL; 489 if (ksiginfo_tryfree(ksi) && p != NULL) 490 p->p_pendingcnt--; 491 } 492 493 SIGEMPTYSET(sq->sq_signals); 494 SIGEMPTYSET(sq->sq_kill); 495 SIGEMPTYSET(sq->sq_ptrace); 496 } 497 498 static void 499 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 500 { 501 sigset_t tmp; 502 struct proc *p1, *p2; 503 ksiginfo_t *ksi, *next; 504 505 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 506 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 507 p1 = src->sq_proc; 508 p2 = dst->sq_proc; 509 /* Move siginfo to target list */ 510 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 511 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 512 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 513 if (p1 != NULL) 514 p1->p_pendingcnt--; 515 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 516 ksi->ksi_sigq = dst; 517 if (p2 != NULL) 518 p2->p_pendingcnt++; 519 } 520 } 521 522 /* Move pending bits to target list */ 523 tmp = src->sq_kill; 524 SIGSETAND(tmp, *set); 525 SIGSETOR(dst->sq_kill, tmp); 526 SIGSETNAND(src->sq_kill, tmp); 527 528 tmp = src->sq_ptrace; 529 SIGSETAND(tmp, *set); 530 SIGSETOR(dst->sq_ptrace, tmp); 531 SIGSETNAND(src->sq_ptrace, tmp); 532 533 tmp = src->sq_signals; 534 SIGSETAND(tmp, *set); 535 SIGSETOR(dst->sq_signals, tmp); 536 SIGSETNAND(src->sq_signals, tmp); 537 } 538 539 #if 0 540 static void 541 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 542 { 543 sigset_t set; 544 545 SIGEMPTYSET(set); 546 SIGADDSET(set, signo); 547 sigqueue_move_set(src, dst, &set); 548 } 549 #endif 550 551 static void 552 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 553 { 554 struct proc *p = sq->sq_proc; 555 ksiginfo_t *ksi, *next; 556 557 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 558 559 /* Remove siginfo queue */ 560 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 561 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 562 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 563 ksi->ksi_sigq = NULL; 564 if (ksiginfo_tryfree(ksi) && p != NULL) 565 p->p_pendingcnt--; 566 } 567 } 568 SIGSETNAND(sq->sq_kill, *set); 569 SIGSETNAND(sq->sq_ptrace, *set); 570 SIGSETNAND(sq->sq_signals, *set); 571 } 572 573 void 574 sigqueue_delete(sigqueue_t *sq, int signo) 575 { 576 sigset_t set; 577 578 SIGEMPTYSET(set); 579 SIGADDSET(set, signo); 580 sigqueue_delete_set(sq, &set); 581 } 582 583 /* Remove a set of signals for a process */ 584 static void 585 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 586 { 587 sigqueue_t worklist; 588 struct thread *td0; 589 590 PROC_LOCK_ASSERT(p, MA_OWNED); 591 592 sigqueue_init(&worklist, NULL); 593 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 594 595 FOREACH_THREAD_IN_PROC(p, td0) 596 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 597 598 sigqueue_flush(&worklist); 599 } 600 601 void 602 sigqueue_delete_proc(struct proc *p, int signo) 603 { 604 sigset_t set; 605 606 SIGEMPTYSET(set); 607 SIGADDSET(set, signo); 608 sigqueue_delete_set_proc(p, &set); 609 } 610 611 static void 612 sigqueue_delete_stopmask_proc(struct proc *p) 613 { 614 sigset_t set; 615 616 SIGEMPTYSET(set); 617 SIGADDSET(set, SIGSTOP); 618 SIGADDSET(set, SIGTSTP); 619 SIGADDSET(set, SIGTTIN); 620 SIGADDSET(set, SIGTTOU); 621 sigqueue_delete_set_proc(p, &set); 622 } 623 624 /* 625 * Determine signal that should be delivered to thread td, the current 626 * thread, 0 if none. If there is a pending stop signal with default 627 * action, the process stops in issignal(). 628 */ 629 int 630 cursig(struct thread *td) 631 { 632 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 633 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 634 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 635 return (SIGPENDING(td) ? issignal(td) : 0); 636 } 637 638 /* 639 * Arrange for ast() to handle unmasked pending signals on return to user 640 * mode. This must be called whenever a signal is added to td_sigqueue or 641 * unmasked in td_sigmask. 642 */ 643 void 644 signotify(struct thread *td) 645 { 646 647 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 648 649 if (SIGPENDING(td)) { 650 thread_lock(td); 651 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 652 thread_unlock(td); 653 } 654 } 655 656 /* 657 * Returns 1 (true) if altstack is configured for the thread, and the 658 * passed stack bottom address falls into the altstack range. Handles 659 * the 43 compat special case where the alt stack size is zero. 660 */ 661 int 662 sigonstack(size_t sp) 663 { 664 struct thread *td; 665 666 td = curthread; 667 if ((td->td_pflags & TDP_ALTSTACK) == 0) 668 return (0); 669 #if defined(COMPAT_43) 670 if (SV_PROC_FLAG(td->td_proc, SV_AOUT) && td->td_sigstk.ss_size == 0) 671 return ((td->td_sigstk.ss_flags & SS_ONSTACK) != 0); 672 #endif 673 return (sp >= (size_t)td->td_sigstk.ss_sp && 674 sp < td->td_sigstk.ss_size + (size_t)td->td_sigstk.ss_sp); 675 } 676 677 static __inline int 678 sigprop(int sig) 679 { 680 681 if (sig > 0 && sig < nitems(sigproptbl)) 682 return (sigproptbl[sig]); 683 return (0); 684 } 685 686 static bool 687 sigact_flag_test(const struct sigaction *act, int flag) 688 { 689 690 /* 691 * SA_SIGINFO is reset when signal disposition is set to 692 * ignore or default. Other flags are kept according to user 693 * settings. 694 */ 695 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 696 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 697 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 698 } 699 700 /* 701 * kern_sigaction 702 * sigaction 703 * freebsd4_sigaction 704 * osigaction 705 */ 706 int 707 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 708 struct sigaction *oact, int flags) 709 { 710 struct sigacts *ps; 711 struct proc *p = td->td_proc; 712 713 if (!_SIG_VALID(sig)) 714 return (EINVAL); 715 if (act != NULL && act->sa_handler != SIG_DFL && 716 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 717 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 718 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 719 return (EINVAL); 720 721 PROC_LOCK(p); 722 ps = p->p_sigacts; 723 mtx_lock(&ps->ps_mtx); 724 if (oact) { 725 memset(oact, 0, sizeof(*oact)); 726 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 727 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 728 oact->sa_flags |= SA_ONSTACK; 729 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 730 oact->sa_flags |= SA_RESTART; 731 if (SIGISMEMBER(ps->ps_sigreset, sig)) 732 oact->sa_flags |= SA_RESETHAND; 733 if (SIGISMEMBER(ps->ps_signodefer, sig)) 734 oact->sa_flags |= SA_NODEFER; 735 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 736 oact->sa_flags |= SA_SIGINFO; 737 oact->sa_sigaction = 738 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 739 } else 740 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 741 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 742 oact->sa_flags |= SA_NOCLDSTOP; 743 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 744 oact->sa_flags |= SA_NOCLDWAIT; 745 } 746 if (act) { 747 if ((sig == SIGKILL || sig == SIGSTOP) && 748 act->sa_handler != SIG_DFL) { 749 mtx_unlock(&ps->ps_mtx); 750 PROC_UNLOCK(p); 751 return (EINVAL); 752 } 753 754 /* 755 * Change setting atomically. 756 */ 757 758 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 759 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 760 if (sigact_flag_test(act, SA_SIGINFO)) { 761 ps->ps_sigact[_SIG_IDX(sig)] = 762 (__sighandler_t *)act->sa_sigaction; 763 SIGADDSET(ps->ps_siginfo, sig); 764 } else { 765 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 766 SIGDELSET(ps->ps_siginfo, sig); 767 } 768 if (!sigact_flag_test(act, SA_RESTART)) 769 SIGADDSET(ps->ps_sigintr, sig); 770 else 771 SIGDELSET(ps->ps_sigintr, sig); 772 if (sigact_flag_test(act, SA_ONSTACK)) 773 SIGADDSET(ps->ps_sigonstack, sig); 774 else 775 SIGDELSET(ps->ps_sigonstack, sig); 776 if (sigact_flag_test(act, SA_RESETHAND)) 777 SIGADDSET(ps->ps_sigreset, sig); 778 else 779 SIGDELSET(ps->ps_sigreset, sig); 780 if (sigact_flag_test(act, SA_NODEFER)) 781 SIGADDSET(ps->ps_signodefer, sig); 782 else 783 SIGDELSET(ps->ps_signodefer, sig); 784 if (sig == SIGCHLD) { 785 if (act->sa_flags & SA_NOCLDSTOP) 786 ps->ps_flag |= PS_NOCLDSTOP; 787 else 788 ps->ps_flag &= ~PS_NOCLDSTOP; 789 if (act->sa_flags & SA_NOCLDWAIT) { 790 /* 791 * Paranoia: since SA_NOCLDWAIT is implemented 792 * by reparenting the dying child to PID 1 (and 793 * trust it to reap the zombie), PID 1 itself 794 * is forbidden to set SA_NOCLDWAIT. 795 */ 796 if (p->p_pid == 1) 797 ps->ps_flag &= ~PS_NOCLDWAIT; 798 else 799 ps->ps_flag |= PS_NOCLDWAIT; 800 } else 801 ps->ps_flag &= ~PS_NOCLDWAIT; 802 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 803 ps->ps_flag |= PS_CLDSIGIGN; 804 else 805 ps->ps_flag &= ~PS_CLDSIGIGN; 806 } 807 /* 808 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 809 * and for signals set to SIG_DFL where the default is to 810 * ignore. However, don't put SIGCONT in ps_sigignore, as we 811 * have to restart the process. 812 */ 813 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 814 (sigprop(sig) & SIGPROP_IGNORE && 815 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 816 /* never to be seen again */ 817 sigqueue_delete_proc(p, sig); 818 if (sig != SIGCONT) 819 /* easier in psignal */ 820 SIGADDSET(ps->ps_sigignore, sig); 821 SIGDELSET(ps->ps_sigcatch, sig); 822 } else { 823 SIGDELSET(ps->ps_sigignore, sig); 824 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 825 SIGDELSET(ps->ps_sigcatch, sig); 826 else 827 SIGADDSET(ps->ps_sigcatch, sig); 828 } 829 #ifdef COMPAT_FREEBSD4 830 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 831 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 832 (flags & KSA_FREEBSD4) == 0) 833 SIGDELSET(ps->ps_freebsd4, sig); 834 else 835 SIGADDSET(ps->ps_freebsd4, sig); 836 #endif 837 #ifdef COMPAT_43 838 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 839 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 840 (flags & KSA_OSIGSET) == 0) 841 SIGDELSET(ps->ps_osigset, sig); 842 else 843 SIGADDSET(ps->ps_osigset, sig); 844 #endif 845 } 846 mtx_unlock(&ps->ps_mtx); 847 PROC_UNLOCK(p); 848 return (0); 849 } 850 851 #ifndef _SYS_SYSPROTO_H_ 852 struct sigaction_args { 853 int sig; 854 struct sigaction *act; 855 struct sigaction *oact; 856 }; 857 #endif 858 int 859 sys_sigaction(struct thread *td, struct sigaction_args *uap) 860 { 861 struct sigaction act, oact; 862 struct sigaction *actp, *oactp; 863 int error; 864 865 actp = (uap->act != NULL) ? &act : NULL; 866 oactp = (uap->oact != NULL) ? &oact : NULL; 867 if (actp) { 868 error = copyin(uap->act, actp, sizeof(act)); 869 if (error) 870 return (error); 871 } 872 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 873 if (oactp && !error) 874 error = copyout(oactp, uap->oact, sizeof(oact)); 875 return (error); 876 } 877 878 #ifdef COMPAT_FREEBSD4 879 #ifndef _SYS_SYSPROTO_H_ 880 struct freebsd4_sigaction_args { 881 int sig; 882 struct sigaction *act; 883 struct sigaction *oact; 884 }; 885 #endif 886 int 887 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 888 { 889 struct sigaction act, oact; 890 struct sigaction *actp, *oactp; 891 int error; 892 893 actp = (uap->act != NULL) ? &act : NULL; 894 oactp = (uap->oact != NULL) ? &oact : NULL; 895 if (actp) { 896 error = copyin(uap->act, actp, sizeof(act)); 897 if (error) 898 return (error); 899 } 900 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 901 if (oactp && !error) 902 error = copyout(oactp, uap->oact, sizeof(oact)); 903 return (error); 904 } 905 #endif /* COMAPT_FREEBSD4 */ 906 907 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 908 #ifndef _SYS_SYSPROTO_H_ 909 struct osigaction_args { 910 int signum; 911 struct osigaction *nsa; 912 struct osigaction *osa; 913 }; 914 #endif 915 int 916 osigaction(struct thread *td, struct osigaction_args *uap) 917 { 918 struct osigaction sa; 919 struct sigaction nsa, osa; 920 struct sigaction *nsap, *osap; 921 int error; 922 923 if (uap->signum <= 0 || uap->signum >= ONSIG) 924 return (EINVAL); 925 926 nsap = (uap->nsa != NULL) ? &nsa : NULL; 927 osap = (uap->osa != NULL) ? &osa : NULL; 928 929 if (nsap) { 930 error = copyin(uap->nsa, &sa, sizeof(sa)); 931 if (error) 932 return (error); 933 nsap->sa_handler = sa.sa_handler; 934 nsap->sa_flags = sa.sa_flags; 935 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 936 } 937 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 938 if (osap && !error) { 939 sa.sa_handler = osap->sa_handler; 940 sa.sa_flags = osap->sa_flags; 941 SIG2OSIG(osap->sa_mask, sa.sa_mask); 942 error = copyout(&sa, uap->osa, sizeof(sa)); 943 } 944 return (error); 945 } 946 947 #if !defined(__i386__) 948 /* Avoid replicating the same stub everywhere */ 949 int 950 osigreturn(struct thread *td, struct osigreturn_args *uap) 951 { 952 953 return (nosys(td, (struct nosys_args *)uap)); 954 } 955 #endif 956 #endif /* COMPAT_43 */ 957 958 /* 959 * Initialize signal state for process 0; 960 * set to ignore signals that are ignored by default. 961 */ 962 void 963 siginit(struct proc *p) 964 { 965 int i; 966 struct sigacts *ps; 967 968 PROC_LOCK(p); 969 ps = p->p_sigacts; 970 mtx_lock(&ps->ps_mtx); 971 for (i = 1; i <= NSIG; i++) { 972 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 973 SIGADDSET(ps->ps_sigignore, i); 974 } 975 } 976 mtx_unlock(&ps->ps_mtx); 977 PROC_UNLOCK(p); 978 } 979 980 /* 981 * Reset specified signal to the default disposition. 982 */ 983 static void 984 sigdflt(struct sigacts *ps, int sig) 985 { 986 987 mtx_assert(&ps->ps_mtx, MA_OWNED); 988 SIGDELSET(ps->ps_sigcatch, sig); 989 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 990 SIGADDSET(ps->ps_sigignore, sig); 991 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 992 SIGDELSET(ps->ps_siginfo, sig); 993 } 994 995 /* 996 * Reset signals for an exec of the specified process. 997 */ 998 void 999 execsigs(struct proc *p) 1000 { 1001 sigset_t osigignore; 1002 struct sigacts *ps; 1003 int sig; 1004 struct thread *td; 1005 1006 /* 1007 * Reset caught signals. Held signals remain held 1008 * through td_sigmask (unless they were caught, 1009 * and are now ignored by default). 1010 */ 1011 PROC_LOCK_ASSERT(p, MA_OWNED); 1012 ps = p->p_sigacts; 1013 mtx_lock(&ps->ps_mtx); 1014 sig_drop_caught(p); 1015 1016 /* 1017 * As CloudABI processes cannot modify signal handlers, fully 1018 * reset all signals to their default behavior. Do ignore 1019 * SIGPIPE, as it would otherwise be impossible to recover from 1020 * writes to broken pipes and sockets. 1021 */ 1022 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 1023 osigignore = ps->ps_sigignore; 1024 SIG_FOREACH(sig, &osigignore) { 1025 if (sig != SIGPIPE) 1026 sigdflt(ps, sig); 1027 } 1028 SIGADDSET(ps->ps_sigignore, SIGPIPE); 1029 } 1030 1031 /* 1032 * Reset stack state to the user stack. 1033 * Clear set of signals caught on the signal stack. 1034 */ 1035 td = curthread; 1036 MPASS(td->td_proc == p); 1037 td->td_sigstk.ss_flags = SS_DISABLE; 1038 td->td_sigstk.ss_size = 0; 1039 td->td_sigstk.ss_sp = 0; 1040 td->td_pflags &= ~TDP_ALTSTACK; 1041 /* 1042 * Reset no zombies if child dies flag as Solaris does. 1043 */ 1044 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1045 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1046 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1047 mtx_unlock(&ps->ps_mtx); 1048 } 1049 1050 /* 1051 * kern_sigprocmask() 1052 * 1053 * Manipulate signal mask. 1054 */ 1055 int 1056 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1057 int flags) 1058 { 1059 sigset_t new_block, oset1; 1060 struct proc *p; 1061 int error; 1062 1063 p = td->td_proc; 1064 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1065 PROC_LOCK_ASSERT(p, MA_OWNED); 1066 else 1067 PROC_LOCK(p); 1068 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1069 ? MA_OWNED : MA_NOTOWNED); 1070 if (oset != NULL) 1071 *oset = td->td_sigmask; 1072 1073 error = 0; 1074 if (set != NULL) { 1075 switch (how) { 1076 case SIG_BLOCK: 1077 SIG_CANTMASK(*set); 1078 oset1 = td->td_sigmask; 1079 SIGSETOR(td->td_sigmask, *set); 1080 new_block = td->td_sigmask; 1081 SIGSETNAND(new_block, oset1); 1082 break; 1083 case SIG_UNBLOCK: 1084 SIGSETNAND(td->td_sigmask, *set); 1085 signotify(td); 1086 goto out; 1087 case SIG_SETMASK: 1088 SIG_CANTMASK(*set); 1089 oset1 = td->td_sigmask; 1090 if (flags & SIGPROCMASK_OLD) 1091 SIGSETLO(td->td_sigmask, *set); 1092 else 1093 td->td_sigmask = *set; 1094 new_block = td->td_sigmask; 1095 SIGSETNAND(new_block, oset1); 1096 signotify(td); 1097 break; 1098 default: 1099 error = EINVAL; 1100 goto out; 1101 } 1102 1103 /* 1104 * The new_block set contains signals that were not previously 1105 * blocked, but are blocked now. 1106 * 1107 * In case we block any signal that was not previously blocked 1108 * for td, and process has the signal pending, try to schedule 1109 * signal delivery to some thread that does not block the 1110 * signal, possibly waking it up. 1111 */ 1112 if (p->p_numthreads != 1) 1113 reschedule_signals(p, new_block, flags); 1114 } 1115 1116 out: 1117 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1118 PROC_UNLOCK(p); 1119 return (error); 1120 } 1121 1122 #ifndef _SYS_SYSPROTO_H_ 1123 struct sigprocmask_args { 1124 int how; 1125 const sigset_t *set; 1126 sigset_t *oset; 1127 }; 1128 #endif 1129 int 1130 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1131 { 1132 sigset_t set, oset; 1133 sigset_t *setp, *osetp; 1134 int error; 1135 1136 setp = (uap->set != NULL) ? &set : NULL; 1137 osetp = (uap->oset != NULL) ? &oset : NULL; 1138 if (setp) { 1139 error = copyin(uap->set, setp, sizeof(set)); 1140 if (error) 1141 return (error); 1142 } 1143 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1144 if (osetp && !error) { 1145 error = copyout(osetp, uap->oset, sizeof(oset)); 1146 } 1147 return (error); 1148 } 1149 1150 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1151 #ifndef _SYS_SYSPROTO_H_ 1152 struct osigprocmask_args { 1153 int how; 1154 osigset_t mask; 1155 }; 1156 #endif 1157 int 1158 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1159 { 1160 sigset_t set, oset; 1161 int error; 1162 1163 OSIG2SIG(uap->mask, set); 1164 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1165 SIG2OSIG(oset, td->td_retval[0]); 1166 return (error); 1167 } 1168 #endif /* COMPAT_43 */ 1169 1170 int 1171 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1172 { 1173 ksiginfo_t ksi; 1174 sigset_t set; 1175 int error; 1176 1177 error = copyin(uap->set, &set, sizeof(set)); 1178 if (error) { 1179 td->td_retval[0] = error; 1180 return (0); 1181 } 1182 1183 error = kern_sigtimedwait(td, set, &ksi, NULL); 1184 if (error) { 1185 /* 1186 * sigwait() function shall not return EINTR, but 1187 * the syscall does. Non-ancient libc provides the 1188 * wrapper which hides EINTR. Otherwise, EINTR return 1189 * is used by libthr to handle required cancellation 1190 * point in the sigwait(). 1191 */ 1192 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1193 return (ERESTART); 1194 td->td_retval[0] = error; 1195 return (0); 1196 } 1197 1198 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1199 td->td_retval[0] = error; 1200 return (0); 1201 } 1202 1203 int 1204 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1205 { 1206 struct timespec ts; 1207 struct timespec *timeout; 1208 sigset_t set; 1209 ksiginfo_t ksi; 1210 int error; 1211 1212 if (uap->timeout) { 1213 error = copyin(uap->timeout, &ts, sizeof(ts)); 1214 if (error) 1215 return (error); 1216 1217 timeout = &ts; 1218 } else 1219 timeout = NULL; 1220 1221 error = copyin(uap->set, &set, sizeof(set)); 1222 if (error) 1223 return (error); 1224 1225 error = kern_sigtimedwait(td, set, &ksi, timeout); 1226 if (error) 1227 return (error); 1228 1229 if (uap->info) 1230 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1231 1232 if (error == 0) 1233 td->td_retval[0] = ksi.ksi_signo; 1234 return (error); 1235 } 1236 1237 int 1238 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1239 { 1240 ksiginfo_t ksi; 1241 sigset_t set; 1242 int error; 1243 1244 error = copyin(uap->set, &set, sizeof(set)); 1245 if (error) 1246 return (error); 1247 1248 error = kern_sigtimedwait(td, set, &ksi, NULL); 1249 if (error) 1250 return (error); 1251 1252 if (uap->info) 1253 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1254 1255 if (error == 0) 1256 td->td_retval[0] = ksi.ksi_signo; 1257 return (error); 1258 } 1259 1260 static void 1261 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1262 { 1263 struct thread *thr; 1264 1265 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1266 if (thr == td) 1267 thr->td_si = *si; 1268 else 1269 thr->td_si.si_signo = 0; 1270 } 1271 } 1272 1273 int 1274 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1275 struct timespec *timeout) 1276 { 1277 struct sigacts *ps; 1278 sigset_t saved_mask, new_block; 1279 struct proc *p; 1280 int error, sig, timo, timevalid = 0; 1281 struct timespec rts, ets, ts; 1282 struct timeval tv; 1283 bool traced; 1284 1285 p = td->td_proc; 1286 error = 0; 1287 ets.tv_sec = 0; 1288 ets.tv_nsec = 0; 1289 traced = false; 1290 1291 /* Ensure the sigfastblock value is up to date. */ 1292 sigfastblock_fetch(td); 1293 1294 if (timeout != NULL) { 1295 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1296 timevalid = 1; 1297 getnanouptime(&rts); 1298 timespecadd(&rts, timeout, &ets); 1299 } 1300 } 1301 ksiginfo_init(ksi); 1302 /* Some signals can not be waited for. */ 1303 SIG_CANTMASK(waitset); 1304 ps = p->p_sigacts; 1305 PROC_LOCK(p); 1306 saved_mask = td->td_sigmask; 1307 SIGSETNAND(td->td_sigmask, waitset); 1308 if ((p->p_sysent->sv_flags & SV_SIG_DISCIGN) != 0 || 1309 !kern_sig_discard_ign) { 1310 thread_lock(td); 1311 td->td_flags |= TDF_SIGWAIT; 1312 thread_unlock(td); 1313 } 1314 for (;;) { 1315 mtx_lock(&ps->ps_mtx); 1316 sig = cursig(td); 1317 mtx_unlock(&ps->ps_mtx); 1318 KASSERT(sig >= 0, ("sig %d", sig)); 1319 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1320 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1321 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1322 error = 0; 1323 break; 1324 } 1325 } 1326 1327 if (error != 0) 1328 break; 1329 1330 /* 1331 * POSIX says this must be checked after looking for pending 1332 * signals. 1333 */ 1334 if (timeout != NULL) { 1335 if (!timevalid) { 1336 error = EINVAL; 1337 break; 1338 } 1339 getnanouptime(&rts); 1340 if (timespeccmp(&rts, &ets, >=)) { 1341 error = EAGAIN; 1342 break; 1343 } 1344 timespecsub(&ets, &rts, &ts); 1345 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1346 timo = tvtohz(&tv); 1347 } else { 1348 timo = 0; 1349 } 1350 1351 if (traced) { 1352 error = EINTR; 1353 break; 1354 } 1355 1356 error = msleep(&p->p_sigacts, &p->p_mtx, PPAUSE | PCATCH, 1357 "sigwait", timo); 1358 1359 /* The syscalls can not be restarted. */ 1360 if (error == ERESTART) 1361 error = EINTR; 1362 1363 /* We will calculate timeout by ourself. */ 1364 if (timeout != NULL && error == EAGAIN) 1365 error = 0; 1366 1367 /* 1368 * If PTRACE_SCE or PTRACE_SCX were set after 1369 * userspace entered the syscall, return spurious 1370 * EINTR after wait was done. Only do this as last 1371 * resort after rechecking for possible queued signals 1372 * and expired timeouts. 1373 */ 1374 if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0) 1375 traced = true; 1376 } 1377 thread_lock(td); 1378 td->td_flags &= ~TDF_SIGWAIT; 1379 thread_unlock(td); 1380 1381 new_block = saved_mask; 1382 SIGSETNAND(new_block, td->td_sigmask); 1383 td->td_sigmask = saved_mask; 1384 /* 1385 * Fewer signals can be delivered to us, reschedule signal 1386 * notification. 1387 */ 1388 if (p->p_numthreads != 1) 1389 reschedule_signals(p, new_block, 0); 1390 1391 if (error == 0) { 1392 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1393 1394 if (ksi->ksi_code == SI_TIMER) 1395 itimer_accept(p, ksi->ksi_timerid, ksi); 1396 1397 #ifdef KTRACE 1398 if (KTRPOINT(td, KTR_PSIG)) { 1399 sig_t action; 1400 1401 mtx_lock(&ps->ps_mtx); 1402 action = ps->ps_sigact[_SIG_IDX(sig)]; 1403 mtx_unlock(&ps->ps_mtx); 1404 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1405 } 1406 #endif 1407 if (sig == SIGKILL) { 1408 proc_td_siginfo_capture(td, &ksi->ksi_info); 1409 sigexit(td, sig); 1410 } 1411 } 1412 PROC_UNLOCK(p); 1413 return (error); 1414 } 1415 1416 #ifndef _SYS_SYSPROTO_H_ 1417 struct sigpending_args { 1418 sigset_t *set; 1419 }; 1420 #endif 1421 int 1422 sys_sigpending(struct thread *td, struct sigpending_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 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1432 } 1433 1434 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1435 #ifndef _SYS_SYSPROTO_H_ 1436 struct osigpending_args { 1437 int dummy; 1438 }; 1439 #endif 1440 int 1441 osigpending(struct thread *td, struct osigpending_args *uap) 1442 { 1443 struct proc *p = td->td_proc; 1444 sigset_t pending; 1445 1446 PROC_LOCK(p); 1447 pending = p->p_sigqueue.sq_signals; 1448 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1449 PROC_UNLOCK(p); 1450 SIG2OSIG(pending, td->td_retval[0]); 1451 return (0); 1452 } 1453 #endif /* COMPAT_43 */ 1454 1455 #if defined(COMPAT_43) 1456 /* 1457 * Generalized interface signal handler, 4.3-compatible. 1458 */ 1459 #ifndef _SYS_SYSPROTO_H_ 1460 struct osigvec_args { 1461 int signum; 1462 struct sigvec *nsv; 1463 struct sigvec *osv; 1464 }; 1465 #endif 1466 /* ARGSUSED */ 1467 int 1468 osigvec(struct thread *td, struct osigvec_args *uap) 1469 { 1470 struct sigvec vec; 1471 struct sigaction nsa, osa; 1472 struct sigaction *nsap, *osap; 1473 int error; 1474 1475 if (uap->signum <= 0 || uap->signum >= ONSIG) 1476 return (EINVAL); 1477 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1478 osap = (uap->osv != NULL) ? &osa : NULL; 1479 if (nsap) { 1480 error = copyin(uap->nsv, &vec, sizeof(vec)); 1481 if (error) 1482 return (error); 1483 nsap->sa_handler = vec.sv_handler; 1484 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1485 nsap->sa_flags = vec.sv_flags; 1486 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1487 } 1488 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1489 if (osap && !error) { 1490 vec.sv_handler = osap->sa_handler; 1491 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1492 vec.sv_flags = osap->sa_flags; 1493 vec.sv_flags &= ~SA_NOCLDWAIT; 1494 vec.sv_flags ^= SA_RESTART; 1495 error = copyout(&vec, uap->osv, sizeof(vec)); 1496 } 1497 return (error); 1498 } 1499 1500 #ifndef _SYS_SYSPROTO_H_ 1501 struct osigblock_args { 1502 int mask; 1503 }; 1504 #endif 1505 int 1506 osigblock(struct thread *td, struct osigblock_args *uap) 1507 { 1508 sigset_t set, oset; 1509 1510 OSIG2SIG(uap->mask, set); 1511 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1512 SIG2OSIG(oset, td->td_retval[0]); 1513 return (0); 1514 } 1515 1516 #ifndef _SYS_SYSPROTO_H_ 1517 struct osigsetmask_args { 1518 int mask; 1519 }; 1520 #endif 1521 int 1522 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1523 { 1524 sigset_t set, oset; 1525 1526 OSIG2SIG(uap->mask, set); 1527 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1528 SIG2OSIG(oset, td->td_retval[0]); 1529 return (0); 1530 } 1531 #endif /* COMPAT_43 */ 1532 1533 /* 1534 * Suspend calling thread until signal, providing mask to be set in the 1535 * meantime. 1536 */ 1537 #ifndef _SYS_SYSPROTO_H_ 1538 struct sigsuspend_args { 1539 const sigset_t *sigmask; 1540 }; 1541 #endif 1542 /* ARGSUSED */ 1543 int 1544 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1545 { 1546 sigset_t mask; 1547 int error; 1548 1549 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1550 if (error) 1551 return (error); 1552 return (kern_sigsuspend(td, mask)); 1553 } 1554 1555 int 1556 kern_sigsuspend(struct thread *td, sigset_t mask) 1557 { 1558 struct proc *p = td->td_proc; 1559 int has_sig, sig; 1560 1561 /* Ensure the sigfastblock value is up to date. */ 1562 sigfastblock_fetch(td); 1563 1564 /* 1565 * When returning from sigsuspend, we want 1566 * the old mask to be restored after the 1567 * signal handler has finished. Thus, we 1568 * save it here and mark the sigacts structure 1569 * to indicate this. 1570 */ 1571 PROC_LOCK(p); 1572 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1573 SIGPROCMASK_PROC_LOCKED); 1574 td->td_pflags |= TDP_OLDMASK; 1575 1576 /* 1577 * Process signals now. Otherwise, we can get spurious wakeup 1578 * due to signal entered process queue, but delivered to other 1579 * thread. But sigsuspend should return only on signal 1580 * delivery. 1581 */ 1582 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1583 for (has_sig = 0; !has_sig;) { 1584 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1585 0) == 0) 1586 /* void */; 1587 thread_suspend_check(0); 1588 mtx_lock(&p->p_sigacts->ps_mtx); 1589 while ((sig = cursig(td)) != 0) { 1590 KASSERT(sig >= 0, ("sig %d", sig)); 1591 has_sig += postsig(sig); 1592 } 1593 mtx_unlock(&p->p_sigacts->ps_mtx); 1594 1595 /* 1596 * If PTRACE_SCE or PTRACE_SCX were set after 1597 * userspace entered the syscall, return spurious 1598 * EINTR. 1599 */ 1600 if ((p->p_ptevents & PTRACE_SYSCALL) != 0) 1601 has_sig += 1; 1602 } 1603 PROC_UNLOCK(p); 1604 td->td_errno = EINTR; 1605 td->td_pflags |= TDP_NERRNO; 1606 return (EJUSTRETURN); 1607 } 1608 1609 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1610 /* 1611 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1612 * convention: libc stub passes mask, not pointer, to save a copyin. 1613 */ 1614 #ifndef _SYS_SYSPROTO_H_ 1615 struct osigsuspend_args { 1616 osigset_t mask; 1617 }; 1618 #endif 1619 /* ARGSUSED */ 1620 int 1621 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1622 { 1623 sigset_t mask; 1624 1625 OSIG2SIG(uap->mask, mask); 1626 return (kern_sigsuspend(td, mask)); 1627 } 1628 #endif /* COMPAT_43 */ 1629 1630 #if defined(COMPAT_43) 1631 #ifndef _SYS_SYSPROTO_H_ 1632 struct osigstack_args { 1633 struct sigstack *nss; 1634 struct sigstack *oss; 1635 }; 1636 #endif 1637 /* ARGSUSED */ 1638 int 1639 osigstack(struct thread *td, struct osigstack_args *uap) 1640 { 1641 struct sigstack nss, oss; 1642 int error = 0; 1643 1644 if (uap->nss != NULL) { 1645 error = copyin(uap->nss, &nss, sizeof(nss)); 1646 if (error) 1647 return (error); 1648 } 1649 oss.ss_sp = td->td_sigstk.ss_sp; 1650 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1651 if (uap->nss != NULL) { 1652 td->td_sigstk.ss_sp = nss.ss_sp; 1653 td->td_sigstk.ss_size = 0; 1654 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1655 td->td_pflags |= TDP_ALTSTACK; 1656 } 1657 if (uap->oss != NULL) 1658 error = copyout(&oss, uap->oss, sizeof(oss)); 1659 1660 return (error); 1661 } 1662 #endif /* COMPAT_43 */ 1663 1664 #ifndef _SYS_SYSPROTO_H_ 1665 struct sigaltstack_args { 1666 stack_t *ss; 1667 stack_t *oss; 1668 }; 1669 #endif 1670 /* ARGSUSED */ 1671 int 1672 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1673 { 1674 stack_t ss, oss; 1675 int error; 1676 1677 if (uap->ss != NULL) { 1678 error = copyin(uap->ss, &ss, sizeof(ss)); 1679 if (error) 1680 return (error); 1681 } 1682 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1683 (uap->oss != NULL) ? &oss : NULL); 1684 if (error) 1685 return (error); 1686 if (uap->oss != NULL) 1687 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1688 return (error); 1689 } 1690 1691 int 1692 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1693 { 1694 struct proc *p = td->td_proc; 1695 int oonstack; 1696 1697 oonstack = sigonstack(cpu_getstack(td)); 1698 1699 if (oss != NULL) { 1700 *oss = td->td_sigstk; 1701 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1702 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1703 } 1704 1705 if (ss != NULL) { 1706 if (oonstack) 1707 return (EPERM); 1708 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1709 return (EINVAL); 1710 if (!(ss->ss_flags & SS_DISABLE)) { 1711 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1712 return (ENOMEM); 1713 1714 td->td_sigstk = *ss; 1715 td->td_pflags |= TDP_ALTSTACK; 1716 } else { 1717 td->td_pflags &= ~TDP_ALTSTACK; 1718 } 1719 } 1720 return (0); 1721 } 1722 1723 struct killpg1_ctx { 1724 struct thread *td; 1725 ksiginfo_t *ksi; 1726 int sig; 1727 bool sent; 1728 bool found; 1729 int ret; 1730 }; 1731 1732 static void 1733 killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg) 1734 { 1735 int err; 1736 1737 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 || 1738 (notself && p == arg->td->td_proc) || p->p_state == PRS_NEW) 1739 return; 1740 PROC_LOCK(p); 1741 err = p_cansignal(arg->td, p, arg->sig); 1742 if (err == 0 && arg->sig != 0) 1743 pksignal(p, arg->sig, arg->ksi); 1744 PROC_UNLOCK(p); 1745 if (err != ESRCH) 1746 arg->found = true; 1747 if (err == 0) 1748 arg->sent = true; 1749 else if (arg->ret == 0 && err != ESRCH && err != EPERM) 1750 arg->ret = err; 1751 } 1752 1753 /* 1754 * Common code for kill process group/broadcast kill. 1755 * cp is calling process. 1756 */ 1757 static int 1758 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1759 { 1760 struct proc *p; 1761 struct pgrp *pgrp; 1762 struct killpg1_ctx arg; 1763 1764 arg.td = td; 1765 arg.ksi = ksi; 1766 arg.sig = sig; 1767 arg.sent = false; 1768 arg.found = false; 1769 arg.ret = 0; 1770 if (all) { 1771 /* 1772 * broadcast 1773 */ 1774 sx_slock(&allproc_lock); 1775 FOREACH_PROC_IN_SYSTEM(p) { 1776 killpg1_sendsig(p, true, &arg); 1777 } 1778 sx_sunlock(&allproc_lock); 1779 } else { 1780 sx_slock(&proctree_lock); 1781 if (pgid == 0) { 1782 /* 1783 * zero pgid means send to my process group. 1784 */ 1785 pgrp = td->td_proc->p_pgrp; 1786 PGRP_LOCK(pgrp); 1787 } else { 1788 pgrp = pgfind(pgid); 1789 if (pgrp == NULL) { 1790 sx_sunlock(&proctree_lock); 1791 return (ESRCH); 1792 } 1793 } 1794 sx_sunlock(&proctree_lock); 1795 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1796 killpg1_sendsig(p, false, &arg); 1797 } 1798 PGRP_UNLOCK(pgrp); 1799 } 1800 MPASS(arg.ret != 0 || arg.found || !arg.sent); 1801 if (arg.ret == 0 && !arg.sent) 1802 arg.ret = arg.found ? EPERM : ESRCH; 1803 return (arg.ret); 1804 } 1805 1806 #ifndef _SYS_SYSPROTO_H_ 1807 struct kill_args { 1808 int pid; 1809 int signum; 1810 }; 1811 #endif 1812 /* ARGSUSED */ 1813 int 1814 sys_kill(struct thread *td, struct kill_args *uap) 1815 { 1816 1817 return (kern_kill(td, uap->pid, uap->signum)); 1818 } 1819 1820 int 1821 kern_kill(struct thread *td, pid_t pid, int signum) 1822 { 1823 ksiginfo_t ksi; 1824 struct proc *p; 1825 int error; 1826 1827 /* 1828 * A process in capability mode can send signals only to himself. 1829 * The main rationale behind this is that abort(3) is implemented as 1830 * kill(getpid(), SIGABRT). 1831 */ 1832 if (IN_CAPABILITY_MODE(td) && pid != td->td_proc->p_pid) 1833 return (ECAPMODE); 1834 1835 AUDIT_ARG_SIGNUM(signum); 1836 AUDIT_ARG_PID(pid); 1837 if ((u_int)signum > _SIG_MAXSIG) 1838 return (EINVAL); 1839 1840 ksiginfo_init(&ksi); 1841 ksi.ksi_signo = signum; 1842 ksi.ksi_code = SI_USER; 1843 ksi.ksi_pid = td->td_proc->p_pid; 1844 ksi.ksi_uid = td->td_ucred->cr_ruid; 1845 1846 if (pid > 0) { 1847 /* kill single process */ 1848 if ((p = pfind_any(pid)) == NULL) 1849 return (ESRCH); 1850 AUDIT_ARG_PROCESS(p); 1851 error = p_cansignal(td, p, signum); 1852 if (error == 0 && signum) 1853 pksignal(p, signum, &ksi); 1854 PROC_UNLOCK(p); 1855 return (error); 1856 } 1857 switch (pid) { 1858 case -1: /* broadcast signal */ 1859 return (killpg1(td, signum, 0, 1, &ksi)); 1860 case 0: /* signal own process group */ 1861 return (killpg1(td, signum, 0, 0, &ksi)); 1862 default: /* negative explicit process group */ 1863 return (killpg1(td, signum, -pid, 0, &ksi)); 1864 } 1865 /* NOTREACHED */ 1866 } 1867 1868 int 1869 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1870 { 1871 struct proc *p; 1872 int error; 1873 1874 AUDIT_ARG_SIGNUM(uap->signum); 1875 AUDIT_ARG_FD(uap->fd); 1876 if ((u_int)uap->signum > _SIG_MAXSIG) 1877 return (EINVAL); 1878 1879 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1880 if (error) 1881 return (error); 1882 AUDIT_ARG_PROCESS(p); 1883 error = p_cansignal(td, p, uap->signum); 1884 if (error == 0 && uap->signum) 1885 kern_psignal(p, uap->signum); 1886 PROC_UNLOCK(p); 1887 return (error); 1888 } 1889 1890 #if defined(COMPAT_43) 1891 #ifndef _SYS_SYSPROTO_H_ 1892 struct okillpg_args { 1893 int pgid; 1894 int signum; 1895 }; 1896 #endif 1897 /* ARGSUSED */ 1898 int 1899 okillpg(struct thread *td, struct okillpg_args *uap) 1900 { 1901 ksiginfo_t ksi; 1902 1903 AUDIT_ARG_SIGNUM(uap->signum); 1904 AUDIT_ARG_PID(uap->pgid); 1905 if ((u_int)uap->signum > _SIG_MAXSIG) 1906 return (EINVAL); 1907 1908 ksiginfo_init(&ksi); 1909 ksi.ksi_signo = uap->signum; 1910 ksi.ksi_code = SI_USER; 1911 ksi.ksi_pid = td->td_proc->p_pid; 1912 ksi.ksi_uid = td->td_ucred->cr_ruid; 1913 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1914 } 1915 #endif /* COMPAT_43 */ 1916 1917 #ifndef _SYS_SYSPROTO_H_ 1918 struct sigqueue_args { 1919 pid_t pid; 1920 int signum; 1921 /* union sigval */ void *value; 1922 }; 1923 #endif 1924 int 1925 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1926 { 1927 union sigval sv; 1928 1929 sv.sival_ptr = uap->value; 1930 1931 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1932 } 1933 1934 int 1935 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1936 { 1937 ksiginfo_t ksi; 1938 struct proc *p; 1939 int error; 1940 1941 if ((u_int)signum > _SIG_MAXSIG) 1942 return (EINVAL); 1943 1944 /* 1945 * Specification says sigqueue can only send signal to 1946 * single process. 1947 */ 1948 if (pid <= 0) 1949 return (EINVAL); 1950 1951 if ((p = pfind_any(pid)) == NULL) 1952 return (ESRCH); 1953 error = p_cansignal(td, p, signum); 1954 if (error == 0 && signum != 0) { 1955 ksiginfo_init(&ksi); 1956 ksi.ksi_flags = KSI_SIGQ; 1957 ksi.ksi_signo = signum; 1958 ksi.ksi_code = SI_QUEUE; 1959 ksi.ksi_pid = td->td_proc->p_pid; 1960 ksi.ksi_uid = td->td_ucred->cr_ruid; 1961 ksi.ksi_value = *value; 1962 error = pksignal(p, ksi.ksi_signo, &ksi); 1963 } 1964 PROC_UNLOCK(p); 1965 return (error); 1966 } 1967 1968 /* 1969 * Send a signal to a process group. 1970 */ 1971 void 1972 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1973 { 1974 struct pgrp *pgrp; 1975 1976 if (pgid != 0) { 1977 sx_slock(&proctree_lock); 1978 pgrp = pgfind(pgid); 1979 sx_sunlock(&proctree_lock); 1980 if (pgrp != NULL) { 1981 pgsignal(pgrp, sig, 0, ksi); 1982 PGRP_UNLOCK(pgrp); 1983 } 1984 } 1985 } 1986 1987 /* 1988 * Send a signal to a process group. If checktty is 1, 1989 * limit to members which have a controlling terminal. 1990 */ 1991 void 1992 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1993 { 1994 struct proc *p; 1995 1996 if (pgrp) { 1997 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1998 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1999 PROC_LOCK(p); 2000 if (p->p_state == PRS_NORMAL && 2001 (checkctty == 0 || p->p_flag & P_CONTROLT)) 2002 pksignal(p, sig, ksi); 2003 PROC_UNLOCK(p); 2004 } 2005 } 2006 } 2007 2008 /* 2009 * Recalculate the signal mask and reset the signal disposition after 2010 * usermode frame for delivery is formed. Should be called after 2011 * mach-specific routine, because sysent->sv_sendsig() needs correct 2012 * ps_siginfo and signal mask. 2013 */ 2014 static void 2015 postsig_done(int sig, struct thread *td, struct sigacts *ps) 2016 { 2017 sigset_t mask; 2018 2019 mtx_assert(&ps->ps_mtx, MA_OWNED); 2020 td->td_ru.ru_nsignals++; 2021 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2022 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2023 SIGADDSET(mask, sig); 2024 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2025 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2026 if (SIGISMEMBER(ps->ps_sigreset, sig)) 2027 sigdflt(ps, sig); 2028 } 2029 2030 /* 2031 * Send a signal caused by a trap to the current thread. If it will be 2032 * caught immediately, deliver it with correct code. Otherwise, post it 2033 * normally. 2034 */ 2035 void 2036 trapsignal(struct thread *td, ksiginfo_t *ksi) 2037 { 2038 struct sigacts *ps; 2039 struct proc *p; 2040 sigset_t sigmask; 2041 int code, sig; 2042 2043 p = td->td_proc; 2044 sig = ksi->ksi_signo; 2045 code = ksi->ksi_code; 2046 KASSERT(_SIG_VALID(sig), ("invalid signal")); 2047 2048 sigfastblock_fetch(td); 2049 PROC_LOCK(p); 2050 ps = p->p_sigacts; 2051 mtx_lock(&ps->ps_mtx); 2052 sigmask = td->td_sigmask; 2053 if (td->td_sigblock_val != 0) 2054 SIGSETOR(sigmask, fastblock_mask); 2055 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 2056 !SIGISMEMBER(sigmask, sig)) { 2057 #ifdef KTRACE 2058 if (KTRPOINT(curthread, KTR_PSIG)) 2059 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 2060 &td->td_sigmask, code); 2061 #endif 2062 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 2063 ksi, &td->td_sigmask); 2064 postsig_done(sig, td, ps); 2065 mtx_unlock(&ps->ps_mtx); 2066 } else { 2067 /* 2068 * Avoid a possible infinite loop if the thread 2069 * masking the signal or process is ignoring the 2070 * signal. 2071 */ 2072 if (kern_forcesigexit && (SIGISMEMBER(sigmask, sig) || 2073 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2074 SIGDELSET(td->td_sigmask, sig); 2075 SIGDELSET(ps->ps_sigcatch, sig); 2076 SIGDELSET(ps->ps_sigignore, sig); 2077 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2078 td->td_pflags &= ~TDP_SIGFASTBLOCK; 2079 td->td_sigblock_val = 0; 2080 } 2081 mtx_unlock(&ps->ps_mtx); 2082 p->p_sig = sig; /* XXX to verify code */ 2083 tdsendsignal(p, td, sig, ksi); 2084 } 2085 PROC_UNLOCK(p); 2086 } 2087 2088 static struct thread * 2089 sigtd(struct proc *p, int sig, bool fast_sigblock) 2090 { 2091 struct thread *td, *signal_td; 2092 2093 PROC_LOCK_ASSERT(p, MA_OWNED); 2094 MPASS(!fast_sigblock || p == curproc); 2095 2096 /* 2097 * Check if current thread can handle the signal without 2098 * switching context to another thread. 2099 */ 2100 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig) && 2101 (!fast_sigblock || curthread->td_sigblock_val == 0)) 2102 return (curthread); 2103 signal_td = NULL; 2104 FOREACH_THREAD_IN_PROC(p, td) { 2105 if (!SIGISMEMBER(td->td_sigmask, sig) && (!fast_sigblock || 2106 td != curthread || td->td_sigblock_val == 0)) { 2107 signal_td = td; 2108 break; 2109 } 2110 } 2111 if (signal_td == NULL) 2112 signal_td = FIRST_THREAD_IN_PROC(p); 2113 return (signal_td); 2114 } 2115 2116 /* 2117 * Send the signal to the process. If the signal has an action, the action 2118 * is usually performed by the target process rather than the caller; we add 2119 * the signal to the set of pending signals for the process. 2120 * 2121 * Exceptions: 2122 * o When a stop signal is sent to a sleeping process that takes the 2123 * default action, the process is stopped without awakening it. 2124 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2125 * regardless of the signal action (eg, blocked or ignored). 2126 * 2127 * Other ignored signals are discarded immediately. 2128 * 2129 * NB: This function may be entered from the debugger via the "kill" DDB 2130 * command. There is little that can be done to mitigate the possibly messy 2131 * side effects of this unwise possibility. 2132 */ 2133 void 2134 kern_psignal(struct proc *p, int sig) 2135 { 2136 ksiginfo_t ksi; 2137 2138 ksiginfo_init(&ksi); 2139 ksi.ksi_signo = sig; 2140 ksi.ksi_code = SI_KERNEL; 2141 (void) tdsendsignal(p, NULL, sig, &ksi); 2142 } 2143 2144 int 2145 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2146 { 2147 2148 return (tdsendsignal(p, NULL, sig, ksi)); 2149 } 2150 2151 /* Utility function for finding a thread to send signal event to. */ 2152 int 2153 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2154 { 2155 struct thread *td; 2156 2157 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2158 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2159 if (td == NULL) 2160 return (ESRCH); 2161 *ttd = td; 2162 } else { 2163 *ttd = NULL; 2164 PROC_LOCK(p); 2165 } 2166 return (0); 2167 } 2168 2169 void 2170 tdsignal(struct thread *td, int sig) 2171 { 2172 ksiginfo_t ksi; 2173 2174 ksiginfo_init(&ksi); 2175 ksi.ksi_signo = sig; 2176 ksi.ksi_code = SI_KERNEL; 2177 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2178 } 2179 2180 void 2181 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2182 { 2183 2184 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2185 } 2186 2187 static int 2188 sig_sleepq_abort(struct thread *td, int intrval) 2189 { 2190 THREAD_LOCK_ASSERT(td, MA_OWNED); 2191 2192 if (intrval == 0 && (td->td_flags & TDF_SIGWAIT) == 0) { 2193 thread_unlock(td); 2194 return (0); 2195 } 2196 return (sleepq_abort(td, intrval)); 2197 } 2198 2199 int 2200 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2201 { 2202 sig_t action; 2203 sigqueue_t *sigqueue; 2204 int prop; 2205 struct sigacts *ps; 2206 int intrval; 2207 int ret = 0; 2208 int wakeup_swapper; 2209 2210 MPASS(td == NULL || p == td->td_proc); 2211 PROC_LOCK_ASSERT(p, MA_OWNED); 2212 2213 if (!_SIG_VALID(sig)) 2214 panic("%s(): invalid signal %d", __func__, sig); 2215 2216 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2217 2218 /* 2219 * IEEE Std 1003.1-2001: return success when killing a zombie. 2220 */ 2221 if (p->p_state == PRS_ZOMBIE) { 2222 if (ksi && (ksi->ksi_flags & KSI_INS)) 2223 ksiginfo_tryfree(ksi); 2224 return (ret); 2225 } 2226 2227 ps = p->p_sigacts; 2228 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2229 prop = sigprop(sig); 2230 2231 if (td == NULL) { 2232 td = sigtd(p, sig, false); 2233 sigqueue = &p->p_sigqueue; 2234 } else 2235 sigqueue = &td->td_sigqueue; 2236 2237 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2238 2239 /* 2240 * If the signal is being ignored, then we forget about it 2241 * immediately, except when the target process executes 2242 * sigwait(). (Note: we don't set SIGCONT in ps_sigignore, 2243 * and if it is set to SIG_IGN, action will be SIG_DFL here.) 2244 */ 2245 mtx_lock(&ps->ps_mtx); 2246 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2247 if (kern_sig_discard_ign && 2248 (p->p_sysent->sv_flags & SV_SIG_DISCIGN) == 0) { 2249 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2250 2251 mtx_unlock(&ps->ps_mtx); 2252 if (ksi && (ksi->ksi_flags & KSI_INS)) 2253 ksiginfo_tryfree(ksi); 2254 return (ret); 2255 } else { 2256 action = SIG_CATCH; 2257 intrval = 0; 2258 } 2259 } else { 2260 if (SIGISMEMBER(td->td_sigmask, sig)) 2261 action = SIG_HOLD; 2262 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2263 action = SIG_CATCH; 2264 else 2265 action = SIG_DFL; 2266 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2267 intrval = EINTR; 2268 else 2269 intrval = ERESTART; 2270 } 2271 mtx_unlock(&ps->ps_mtx); 2272 2273 if (prop & SIGPROP_CONT) 2274 sigqueue_delete_stopmask_proc(p); 2275 else if (prop & SIGPROP_STOP) { 2276 /* 2277 * If sending a tty stop signal to a member of an orphaned 2278 * process group, discard the signal here if the action 2279 * is default; don't stop the process below if sleeping, 2280 * and don't clear any pending SIGCONT. 2281 */ 2282 if ((prop & SIGPROP_TTYSTOP) != 0 && 2283 (p->p_pgrp->pg_flags & PGRP_ORPHANED) != 0 && 2284 action == SIG_DFL) { 2285 if (ksi && (ksi->ksi_flags & KSI_INS)) 2286 ksiginfo_tryfree(ksi); 2287 return (ret); 2288 } 2289 sigqueue_delete_proc(p, SIGCONT); 2290 if (p->p_flag & P_CONTINUED) { 2291 p->p_flag &= ~P_CONTINUED; 2292 PROC_LOCK(p->p_pptr); 2293 sigqueue_take(p->p_ksi); 2294 PROC_UNLOCK(p->p_pptr); 2295 } 2296 } 2297 2298 ret = sigqueue_add(sigqueue, sig, ksi); 2299 if (ret != 0) 2300 return (ret); 2301 signotify(td); 2302 /* 2303 * Defer further processing for signals which are held, 2304 * except that stopped processes must be continued by SIGCONT. 2305 */ 2306 if (action == SIG_HOLD && 2307 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2308 return (ret); 2309 2310 wakeup_swapper = 0; 2311 2312 /* 2313 * Some signals have a process-wide effect and a per-thread 2314 * component. Most processing occurs when the process next 2315 * tries to cross the user boundary, however there are some 2316 * times when processing needs to be done immediately, such as 2317 * waking up threads so that they can cross the user boundary. 2318 * We try to do the per-process part here. 2319 */ 2320 if (P_SHOULDSTOP(p)) { 2321 KASSERT(!(p->p_flag & P_WEXIT), 2322 ("signal to stopped but exiting process")); 2323 if (sig == SIGKILL) { 2324 /* 2325 * If traced process is already stopped, 2326 * then no further action is necessary. 2327 */ 2328 if (p->p_flag & P_TRACED) 2329 goto out; 2330 /* 2331 * SIGKILL sets process running. 2332 * It will die elsewhere. 2333 * All threads must be restarted. 2334 */ 2335 p->p_flag &= ~P_STOPPED_SIG; 2336 goto runfast; 2337 } 2338 2339 if (prop & SIGPROP_CONT) { 2340 /* 2341 * If traced process is already stopped, 2342 * then no further action is necessary. 2343 */ 2344 if (p->p_flag & P_TRACED) 2345 goto out; 2346 /* 2347 * If SIGCONT is default (or ignored), we continue the 2348 * process but don't leave the signal in sigqueue as 2349 * it has no further action. If SIGCONT is held, we 2350 * continue the process and leave the signal in 2351 * sigqueue. If the process catches SIGCONT, let it 2352 * handle the signal itself. If it isn't waiting on 2353 * an event, it goes back to run state. 2354 * Otherwise, process goes back to sleep state. 2355 */ 2356 p->p_flag &= ~P_STOPPED_SIG; 2357 PROC_SLOCK(p); 2358 if (p->p_numthreads == p->p_suspcount) { 2359 PROC_SUNLOCK(p); 2360 p->p_flag |= P_CONTINUED; 2361 p->p_xsig = SIGCONT; 2362 PROC_LOCK(p->p_pptr); 2363 childproc_continued(p); 2364 PROC_UNLOCK(p->p_pptr); 2365 PROC_SLOCK(p); 2366 } 2367 if (action == SIG_DFL) { 2368 thread_unsuspend(p); 2369 PROC_SUNLOCK(p); 2370 sigqueue_delete(sigqueue, sig); 2371 goto out_cont; 2372 } 2373 if (action == SIG_CATCH) { 2374 /* 2375 * The process wants to catch it so it needs 2376 * to run at least one thread, but which one? 2377 */ 2378 PROC_SUNLOCK(p); 2379 goto runfast; 2380 } 2381 /* 2382 * The signal is not ignored or caught. 2383 */ 2384 thread_unsuspend(p); 2385 PROC_SUNLOCK(p); 2386 goto out_cont; 2387 } 2388 2389 if (prop & SIGPROP_STOP) { 2390 /* 2391 * If traced process is already stopped, 2392 * then no further action is necessary. 2393 */ 2394 if (p->p_flag & P_TRACED) 2395 goto out; 2396 /* 2397 * Already stopped, don't need to stop again 2398 * (If we did the shell could get confused). 2399 * Just make sure the signal STOP bit set. 2400 */ 2401 p->p_flag |= P_STOPPED_SIG; 2402 sigqueue_delete(sigqueue, sig); 2403 goto out; 2404 } 2405 2406 /* 2407 * All other kinds of signals: 2408 * If a thread is sleeping interruptibly, simulate a 2409 * wakeup so that when it is continued it will be made 2410 * runnable and can look at the signal. However, don't make 2411 * the PROCESS runnable, leave it stopped. 2412 * It may run a bit until it hits a thread_suspend_check(). 2413 */ 2414 PROC_SLOCK(p); 2415 thread_lock(td); 2416 if (TD_CAN_ABORT(td)) 2417 wakeup_swapper = sig_sleepq_abort(td, intrval); 2418 else 2419 thread_unlock(td); 2420 PROC_SUNLOCK(p); 2421 goto out; 2422 /* 2423 * Mutexes are short lived. Threads waiting on them will 2424 * hit thread_suspend_check() soon. 2425 */ 2426 } else if (p->p_state == PRS_NORMAL) { 2427 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2428 tdsigwakeup(td, sig, action, intrval); 2429 goto out; 2430 } 2431 2432 MPASS(action == SIG_DFL); 2433 2434 if (prop & SIGPROP_STOP) { 2435 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2436 goto out; 2437 p->p_flag |= P_STOPPED_SIG; 2438 p->p_xsig = sig; 2439 PROC_SLOCK(p); 2440 wakeup_swapper = sig_suspend_threads(td, p, 1); 2441 if (p->p_numthreads == p->p_suspcount) { 2442 /* 2443 * only thread sending signal to another 2444 * process can reach here, if thread is sending 2445 * signal to its process, because thread does 2446 * not suspend itself here, p_numthreads 2447 * should never be equal to p_suspcount. 2448 */ 2449 thread_stopped(p); 2450 PROC_SUNLOCK(p); 2451 sigqueue_delete_proc(p, p->p_xsig); 2452 } else 2453 PROC_SUNLOCK(p); 2454 goto out; 2455 } 2456 } else { 2457 /* Not in "NORMAL" state. discard the signal. */ 2458 sigqueue_delete(sigqueue, sig); 2459 goto out; 2460 } 2461 2462 /* 2463 * The process is not stopped so we need to apply the signal to all the 2464 * running threads. 2465 */ 2466 runfast: 2467 tdsigwakeup(td, sig, action, intrval); 2468 PROC_SLOCK(p); 2469 thread_unsuspend(p); 2470 PROC_SUNLOCK(p); 2471 out_cont: 2472 itimer_proc_continue(p); 2473 kqtimer_proc_continue(p); 2474 out: 2475 /* If we jump here, proc slock should not be owned. */ 2476 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2477 if (wakeup_swapper) 2478 kick_proc0(); 2479 2480 return (ret); 2481 } 2482 2483 /* 2484 * The force of a signal has been directed against a single 2485 * thread. We need to see what we can do about knocking it 2486 * out of any sleep it may be in etc. 2487 */ 2488 static void 2489 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2490 { 2491 struct proc *p = td->td_proc; 2492 int prop, wakeup_swapper; 2493 2494 PROC_LOCK_ASSERT(p, MA_OWNED); 2495 prop = sigprop(sig); 2496 2497 PROC_SLOCK(p); 2498 thread_lock(td); 2499 /* 2500 * Bring the priority of a thread up if we want it to get 2501 * killed in this lifetime. Be careful to avoid bumping the 2502 * priority of the idle thread, since we still allow to signal 2503 * kernel processes. 2504 */ 2505 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2506 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2507 sched_prio(td, PUSER); 2508 if (TD_ON_SLEEPQ(td)) { 2509 /* 2510 * If thread is sleeping uninterruptibly 2511 * we can't interrupt the sleep... the signal will 2512 * be noticed when the process returns through 2513 * trap() or syscall(). 2514 */ 2515 if ((td->td_flags & TDF_SINTR) == 0) 2516 goto out; 2517 /* 2518 * If SIGCONT is default (or ignored) and process is 2519 * asleep, we are finished; the process should not 2520 * be awakened. 2521 */ 2522 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2523 thread_unlock(td); 2524 PROC_SUNLOCK(p); 2525 sigqueue_delete(&p->p_sigqueue, sig); 2526 /* 2527 * It may be on either list in this state. 2528 * Remove from both for now. 2529 */ 2530 sigqueue_delete(&td->td_sigqueue, sig); 2531 return; 2532 } 2533 2534 /* 2535 * Don't awaken a sleeping thread for SIGSTOP if the 2536 * STOP signal is deferred. 2537 */ 2538 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2539 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2540 goto out; 2541 2542 /* 2543 * Give low priority threads a better chance to run. 2544 */ 2545 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2546 sched_prio(td, PUSER); 2547 2548 wakeup_swapper = sig_sleepq_abort(td, intrval); 2549 PROC_SUNLOCK(p); 2550 if (wakeup_swapper) 2551 kick_proc0(); 2552 return; 2553 } 2554 2555 /* 2556 * Other states do nothing with the signal immediately, 2557 * other than kicking ourselves if we are running. 2558 * It will either never be noticed, or noticed very soon. 2559 */ 2560 #ifdef SMP 2561 if (TD_IS_RUNNING(td) && td != curthread) 2562 forward_signal(td); 2563 #endif 2564 2565 out: 2566 PROC_SUNLOCK(p); 2567 thread_unlock(td); 2568 } 2569 2570 static void 2571 ptrace_coredump(struct thread *td) 2572 { 2573 struct proc *p; 2574 struct thr_coredump_req *tcq; 2575 void *rl_cookie; 2576 2577 MPASS(td == curthread); 2578 p = td->td_proc; 2579 PROC_LOCK_ASSERT(p, MA_OWNED); 2580 if ((td->td_dbgflags & TDB_COREDUMPRQ) == 0) 2581 return; 2582 KASSERT((p->p_flag & P_STOPPED_TRACE) != 0, ("not stopped")); 2583 2584 tcq = td->td_coredump; 2585 KASSERT(tcq != NULL, ("td_coredump is NULL")); 2586 2587 if (p->p_sysent->sv_coredump == NULL) { 2588 tcq->tc_error = ENOSYS; 2589 goto wake; 2590 } 2591 2592 PROC_UNLOCK(p); 2593 rl_cookie = vn_rangelock_wlock(tcq->tc_vp, 0, OFF_MAX); 2594 2595 tcq->tc_error = p->p_sysent->sv_coredump(td, tcq->tc_vp, 2596 tcq->tc_limit, tcq->tc_flags); 2597 2598 vn_rangelock_unlock(tcq->tc_vp, rl_cookie); 2599 PROC_LOCK(p); 2600 wake: 2601 td->td_dbgflags &= ~TDB_COREDUMPRQ; 2602 td->td_coredump = NULL; 2603 wakeup(p); 2604 } 2605 2606 static int 2607 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2608 { 2609 struct thread *td2; 2610 int wakeup_swapper; 2611 2612 PROC_LOCK_ASSERT(p, MA_OWNED); 2613 PROC_SLOCK_ASSERT(p, MA_OWNED); 2614 MPASS(sending || td == curthread); 2615 2616 wakeup_swapper = 0; 2617 FOREACH_THREAD_IN_PROC(p, td2) { 2618 thread_lock(td2); 2619 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2620 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2621 (td2->td_flags & TDF_SINTR)) { 2622 if (td2->td_flags & TDF_SBDRY) { 2623 /* 2624 * Once a thread is asleep with 2625 * TDF_SBDRY and without TDF_SERESTART 2626 * or TDF_SEINTR set, it should never 2627 * become suspended due to this check. 2628 */ 2629 KASSERT(!TD_IS_SUSPENDED(td2), 2630 ("thread with deferred stops suspended")); 2631 if (TD_SBDRY_INTR(td2)) { 2632 wakeup_swapper |= sleepq_abort(td2, 2633 TD_SBDRY_ERRNO(td2)); 2634 continue; 2635 } 2636 } else if (!TD_IS_SUSPENDED(td2)) 2637 thread_suspend_one(td2); 2638 } else if (!TD_IS_SUSPENDED(td2)) { 2639 if (sending || td != td2) 2640 td2->td_flags |= TDF_ASTPENDING; 2641 #ifdef SMP 2642 if (TD_IS_RUNNING(td2) && td2 != td) 2643 forward_signal(td2); 2644 #endif 2645 } 2646 thread_unlock(td2); 2647 } 2648 return (wakeup_swapper); 2649 } 2650 2651 /* 2652 * Stop the process for an event deemed interesting to the debugger. If si is 2653 * non-NULL, this is a signal exchange; the new signal requested by the 2654 * debugger will be returned for handling. If si is NULL, this is some other 2655 * type of interesting event. The debugger may request a signal be delivered in 2656 * that case as well, however it will be deferred until it can be handled. 2657 */ 2658 int 2659 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2660 { 2661 struct proc *p = td->td_proc; 2662 struct thread *td2; 2663 ksiginfo_t ksi; 2664 2665 PROC_LOCK_ASSERT(p, MA_OWNED); 2666 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2667 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2668 &p->p_mtx.lock_object, "Stopping for traced signal"); 2669 2670 td->td_xsig = sig; 2671 2672 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2673 td->td_dbgflags |= TDB_XSIG; 2674 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2675 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2676 PROC_SLOCK(p); 2677 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2678 if (P_KILLED(p)) { 2679 /* 2680 * Ensure that, if we've been PT_KILLed, the 2681 * exit status reflects that. Another thread 2682 * may also be in ptracestop(), having just 2683 * received the SIGKILL, but this thread was 2684 * unsuspended first. 2685 */ 2686 td->td_dbgflags &= ~TDB_XSIG; 2687 td->td_xsig = SIGKILL; 2688 p->p_ptevents = 0; 2689 break; 2690 } 2691 if (p->p_flag & P_SINGLE_EXIT && 2692 !(td->td_dbgflags & TDB_EXIT)) { 2693 /* 2694 * Ignore ptrace stops except for thread exit 2695 * events when the process exits. 2696 */ 2697 td->td_dbgflags &= ~TDB_XSIG; 2698 PROC_SUNLOCK(p); 2699 return (0); 2700 } 2701 2702 /* 2703 * Make wait(2) work. Ensure that right after the 2704 * attach, the thread which was decided to become the 2705 * leader of attach gets reported to the waiter. 2706 * Otherwise, just avoid overwriting another thread's 2707 * assignment to p_xthread. If another thread has 2708 * already set p_xthread, the current thread will get 2709 * a chance to report itself upon the next iteration. 2710 */ 2711 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2712 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2713 p->p_xthread == NULL)) { 2714 p->p_xsig = sig; 2715 p->p_xthread = td; 2716 2717 /* 2718 * If we are on sleepqueue already, 2719 * let sleepqueue code decide if it 2720 * needs to go sleep after attach. 2721 */ 2722 if (td->td_wchan == NULL) 2723 td->td_dbgflags &= ~TDB_FSTP; 2724 2725 p->p_flag2 &= ~P2_PTRACE_FSTP; 2726 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2727 sig_suspend_threads(td, p, 0); 2728 } 2729 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2730 td->td_dbgflags &= ~TDB_STOPATFORK; 2731 } 2732 stopme: 2733 td->td_dbgflags |= TDB_SSWITCH; 2734 thread_suspend_switch(td, p); 2735 td->td_dbgflags &= ~TDB_SSWITCH; 2736 if ((td->td_dbgflags & TDB_COREDUMPRQ) != 0) { 2737 PROC_SUNLOCK(p); 2738 ptrace_coredump(td); 2739 PROC_SLOCK(p); 2740 goto stopme; 2741 } 2742 if (p->p_xthread == td) 2743 p->p_xthread = NULL; 2744 if (!(p->p_flag & P_TRACED)) 2745 break; 2746 if (td->td_dbgflags & TDB_SUSPEND) { 2747 if (p->p_flag & P_SINGLE_EXIT) 2748 break; 2749 goto stopme; 2750 } 2751 } 2752 PROC_SUNLOCK(p); 2753 } 2754 2755 if (si != NULL && sig == td->td_xsig) { 2756 /* Parent wants us to take the original signal unchanged. */ 2757 si->ksi_flags |= KSI_HEAD; 2758 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2759 si->ksi_signo = 0; 2760 } else if (td->td_xsig != 0) { 2761 /* 2762 * If parent wants us to take a new signal, then it will leave 2763 * it in td->td_xsig; otherwise we just look for signals again. 2764 */ 2765 ksiginfo_init(&ksi); 2766 ksi.ksi_signo = td->td_xsig; 2767 ksi.ksi_flags |= KSI_PTRACE; 2768 td2 = sigtd(p, td->td_xsig, false); 2769 tdsendsignal(p, td2, td->td_xsig, &ksi); 2770 if (td != td2) 2771 return (0); 2772 } 2773 2774 return (td->td_xsig); 2775 } 2776 2777 static void 2778 reschedule_signals(struct proc *p, sigset_t block, int flags) 2779 { 2780 struct sigacts *ps; 2781 struct thread *td; 2782 int sig; 2783 bool fastblk, pslocked; 2784 2785 PROC_LOCK_ASSERT(p, MA_OWNED); 2786 ps = p->p_sigacts; 2787 pslocked = (flags & SIGPROCMASK_PS_LOCKED) != 0; 2788 mtx_assert(&ps->ps_mtx, pslocked ? MA_OWNED : MA_NOTOWNED); 2789 if (SIGISEMPTY(p->p_siglist)) 2790 return; 2791 SIGSETAND(block, p->p_siglist); 2792 fastblk = (flags & SIGPROCMASK_FASTBLK) != 0; 2793 SIG_FOREACH(sig, &block) { 2794 td = sigtd(p, sig, fastblk); 2795 2796 /* 2797 * If sigtd() selected us despite sigfastblock is 2798 * blocking, do not activate AST or wake us, to avoid 2799 * loop in AST handler. 2800 */ 2801 if (fastblk && td == curthread) 2802 continue; 2803 2804 signotify(td); 2805 if (!pslocked) 2806 mtx_lock(&ps->ps_mtx); 2807 if (p->p_flag & P_TRACED || 2808 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2809 !SIGISMEMBER(td->td_sigmask, sig))) { 2810 tdsigwakeup(td, sig, SIG_CATCH, 2811 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2812 ERESTART)); 2813 } 2814 if (!pslocked) 2815 mtx_unlock(&ps->ps_mtx); 2816 } 2817 } 2818 2819 void 2820 tdsigcleanup(struct thread *td) 2821 { 2822 struct proc *p; 2823 sigset_t unblocked; 2824 2825 p = td->td_proc; 2826 PROC_LOCK_ASSERT(p, MA_OWNED); 2827 2828 sigqueue_flush(&td->td_sigqueue); 2829 if (p->p_numthreads == 1) 2830 return; 2831 2832 /* 2833 * Since we cannot handle signals, notify signal post code 2834 * about this by filling the sigmask. 2835 * 2836 * Also, if needed, wake up thread(s) that do not block the 2837 * same signals as the exiting thread, since the thread might 2838 * have been selected for delivery and woken up. 2839 */ 2840 SIGFILLSET(unblocked); 2841 SIGSETNAND(unblocked, td->td_sigmask); 2842 SIGFILLSET(td->td_sigmask); 2843 reschedule_signals(p, unblocked, 0); 2844 2845 } 2846 2847 static int 2848 sigdeferstop_curr_flags(int cflags) 2849 { 2850 2851 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2852 (cflags & TDF_SBDRY) != 0); 2853 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2854 } 2855 2856 /* 2857 * Defer the delivery of SIGSTOP for the current thread, according to 2858 * the requested mode. Returns previous flags, which must be restored 2859 * by sigallowstop(). 2860 * 2861 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2862 * cleared by the current thread, which allow the lock-less read-only 2863 * accesses below. 2864 */ 2865 int 2866 sigdeferstop_impl(int mode) 2867 { 2868 struct thread *td; 2869 int cflags, nflags; 2870 2871 td = curthread; 2872 cflags = sigdeferstop_curr_flags(td->td_flags); 2873 switch (mode) { 2874 case SIGDEFERSTOP_NOP: 2875 nflags = cflags; 2876 break; 2877 case SIGDEFERSTOP_OFF: 2878 nflags = 0; 2879 break; 2880 case SIGDEFERSTOP_SILENT: 2881 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2882 break; 2883 case SIGDEFERSTOP_EINTR: 2884 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2885 break; 2886 case SIGDEFERSTOP_ERESTART: 2887 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2888 break; 2889 default: 2890 panic("sigdeferstop: invalid mode %x", mode); 2891 break; 2892 } 2893 if (cflags == nflags) 2894 return (SIGDEFERSTOP_VAL_NCHG); 2895 thread_lock(td); 2896 td->td_flags = (td->td_flags & ~cflags) | nflags; 2897 thread_unlock(td); 2898 return (cflags); 2899 } 2900 2901 /* 2902 * Restores the STOP handling mode, typically permitting the delivery 2903 * of SIGSTOP for the current thread. This does not immediately 2904 * suspend if a stop was posted. Instead, the thread will suspend 2905 * either via ast() or a subsequent interruptible sleep. 2906 */ 2907 void 2908 sigallowstop_impl(int prev) 2909 { 2910 struct thread *td; 2911 int cflags; 2912 2913 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2914 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2915 ("sigallowstop: incorrect previous mode %x", prev)); 2916 td = curthread; 2917 cflags = sigdeferstop_curr_flags(td->td_flags); 2918 if (cflags != prev) { 2919 thread_lock(td); 2920 td->td_flags = (td->td_flags & ~cflags) | prev; 2921 thread_unlock(td); 2922 } 2923 } 2924 2925 enum sigstatus { 2926 SIGSTATUS_HANDLE, 2927 SIGSTATUS_HANDLED, 2928 SIGSTATUS_IGNORE, 2929 SIGSTATUS_SBDRY_STOP, 2930 }; 2931 2932 /* 2933 * The thread has signal "sig" pending. Figure out what to do with it: 2934 * 2935 * _HANDLE -> the caller should handle the signal 2936 * _HANDLED -> handled internally, reload pending signal set 2937 * _IGNORE -> ignored, remove from the set of pending signals and try the 2938 * next pending signal 2939 * _SBDRY_STOP -> the signal should stop the thread but this is not 2940 * permitted in the current context 2941 */ 2942 static enum sigstatus 2943 sigprocess(struct thread *td, int sig) 2944 { 2945 struct proc *p; 2946 struct sigacts *ps; 2947 struct sigqueue *queue; 2948 ksiginfo_t ksi; 2949 int prop; 2950 2951 KASSERT(_SIG_VALID(sig), ("%s: invalid signal %d", __func__, sig)); 2952 2953 p = td->td_proc; 2954 ps = p->p_sigacts; 2955 mtx_assert(&ps->ps_mtx, MA_OWNED); 2956 PROC_LOCK_ASSERT(p, MA_OWNED); 2957 2958 /* 2959 * We should allow pending but ignored signals below 2960 * only if there is sigwait() active, or P_TRACED was 2961 * on when they were posted. 2962 */ 2963 if (SIGISMEMBER(ps->ps_sigignore, sig) && 2964 (p->p_flag & P_TRACED) == 0 && 2965 (td->td_flags & TDF_SIGWAIT) == 0) { 2966 return (SIGSTATUS_IGNORE); 2967 } 2968 2969 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2970 /* 2971 * If traced, always stop. 2972 * Remove old signal from queue before the stop. 2973 * XXX shrug off debugger, it causes siginfo to 2974 * be thrown away. 2975 */ 2976 queue = &td->td_sigqueue; 2977 ksiginfo_init(&ksi); 2978 if (sigqueue_get(queue, sig, &ksi) == 0) { 2979 queue = &p->p_sigqueue; 2980 sigqueue_get(queue, sig, &ksi); 2981 } 2982 td->td_si = ksi.ksi_info; 2983 2984 mtx_unlock(&ps->ps_mtx); 2985 sig = ptracestop(td, sig, &ksi); 2986 mtx_lock(&ps->ps_mtx); 2987 2988 td->td_si.si_signo = 0; 2989 2990 /* 2991 * Keep looking if the debugger discarded or 2992 * replaced the signal. 2993 */ 2994 if (sig == 0) 2995 return (SIGSTATUS_HANDLED); 2996 2997 /* 2998 * If the signal became masked, re-queue it. 2999 */ 3000 if (SIGISMEMBER(td->td_sigmask, sig)) { 3001 ksi.ksi_flags |= KSI_HEAD; 3002 sigqueue_add(&p->p_sigqueue, sig, &ksi); 3003 return (SIGSTATUS_HANDLED); 3004 } 3005 3006 /* 3007 * If the traced bit got turned off, requeue the signal and 3008 * reload the set of pending signals. This ensures that p_sig* 3009 * and p_sigact are consistent. 3010 */ 3011 if ((p->p_flag & P_TRACED) == 0) { 3012 ksi.ksi_flags |= KSI_HEAD; 3013 sigqueue_add(queue, sig, &ksi); 3014 return (SIGSTATUS_HANDLED); 3015 } 3016 } 3017 3018 /* 3019 * Decide whether the signal should be returned. 3020 * Return the signal's number, or fall through 3021 * to clear it from the pending mask. 3022 */ 3023 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 3024 case (intptr_t)SIG_DFL: 3025 /* 3026 * Don't take default actions on system processes. 3027 */ 3028 if (p->p_pid <= 1) { 3029 #ifdef DIAGNOSTIC 3030 /* 3031 * Are you sure you want to ignore SIGSEGV 3032 * in init? XXX 3033 */ 3034 printf("Process (pid %lu) got signal %d\n", 3035 (u_long)p->p_pid, sig); 3036 #endif 3037 return (SIGSTATUS_IGNORE); 3038 } 3039 3040 /* 3041 * If there is a pending stop signal to process with 3042 * default action, stop here, then clear the signal. 3043 * Traced or exiting processes should ignore stops. 3044 * Additionally, a member of an orphaned process group 3045 * should ignore tty stops. 3046 */ 3047 prop = sigprop(sig); 3048 if (prop & SIGPROP_STOP) { 3049 mtx_unlock(&ps->ps_mtx); 3050 if ((p->p_flag & (P_TRACED | P_WEXIT | 3051 P_SINGLE_EXIT)) != 0 || ((p->p_pgrp-> 3052 pg_flags & PGRP_ORPHANED) != 0 && 3053 (prop & SIGPROP_TTYSTOP) != 0)) { 3054 mtx_lock(&ps->ps_mtx); 3055 return (SIGSTATUS_IGNORE); 3056 } 3057 if (TD_SBDRY_INTR(td)) { 3058 KASSERT((td->td_flags & TDF_SBDRY) != 0, 3059 ("lost TDF_SBDRY")); 3060 mtx_lock(&ps->ps_mtx); 3061 return (SIGSTATUS_SBDRY_STOP); 3062 } 3063 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 3064 &p->p_mtx.lock_object, "Catching SIGSTOP"); 3065 sigqueue_delete(&td->td_sigqueue, sig); 3066 sigqueue_delete(&p->p_sigqueue, sig); 3067 p->p_flag |= P_STOPPED_SIG; 3068 p->p_xsig = sig; 3069 PROC_SLOCK(p); 3070 sig_suspend_threads(td, p, 0); 3071 thread_suspend_switch(td, p); 3072 PROC_SUNLOCK(p); 3073 mtx_lock(&ps->ps_mtx); 3074 return (SIGSTATUS_HANDLED); 3075 } else if ((prop & SIGPROP_IGNORE) != 0 && 3076 (td->td_flags & TDF_SIGWAIT) == 0) { 3077 /* 3078 * Default action is to ignore; drop it if 3079 * not in kern_sigtimedwait(). 3080 */ 3081 return (SIGSTATUS_IGNORE); 3082 } else { 3083 return (SIGSTATUS_HANDLE); 3084 } 3085 3086 case (intptr_t)SIG_IGN: 3087 if ((td->td_flags & TDF_SIGWAIT) == 0) 3088 return (SIGSTATUS_IGNORE); 3089 else 3090 return (SIGSTATUS_HANDLE); 3091 3092 default: 3093 /* 3094 * This signal has an action, let postsig() process it. 3095 */ 3096 return (SIGSTATUS_HANDLE); 3097 } 3098 } 3099 3100 /* 3101 * If the current process has received a signal (should be caught or cause 3102 * termination, should interrupt current syscall), return the signal number. 3103 * Stop signals with default action are processed immediately, then cleared; 3104 * they aren't returned. This is checked after each entry to the system for 3105 * a syscall or trap (though this can usually be done without calling 3106 * issignal by checking the pending signal masks in cursig.) The normal call 3107 * sequence is 3108 * 3109 * while (sig = cursig(curthread)) 3110 * postsig(sig); 3111 */ 3112 static int 3113 issignal(struct thread *td) 3114 { 3115 struct proc *p; 3116 sigset_t sigpending; 3117 int sig; 3118 3119 p = td->td_proc; 3120 PROC_LOCK_ASSERT(p, MA_OWNED); 3121 3122 for (;;) { 3123 sigpending = td->td_sigqueue.sq_signals; 3124 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 3125 SIGSETNAND(sigpending, td->td_sigmask); 3126 3127 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 3128 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 3129 SIG_STOPSIGMASK(sigpending); 3130 if (SIGISEMPTY(sigpending)) /* no signal to send */ 3131 return (0); 3132 3133 /* 3134 * Do fast sigblock if requested by usermode. Since 3135 * we do know that there was a signal pending at this 3136 * point, set the FAST_SIGBLOCK_PEND as indicator for 3137 * usermode to perform a dummy call to 3138 * FAST_SIGBLOCK_UNBLOCK, which causes immediate 3139 * delivery of postponed pending signal. 3140 */ 3141 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 3142 if (td->td_sigblock_val != 0) 3143 SIGSETNAND(sigpending, fastblock_mask); 3144 if (SIGISEMPTY(sigpending)) { 3145 td->td_pflags |= TDP_SIGFASTPENDING; 3146 return (0); 3147 } 3148 } 3149 3150 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 3151 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 3152 SIGISMEMBER(sigpending, SIGSTOP)) { 3153 /* 3154 * If debugger just attached, always consume 3155 * SIGSTOP from ptrace(PT_ATTACH) first, to 3156 * execute the debugger attach ritual in 3157 * order. 3158 */ 3159 td->td_dbgflags |= TDB_FSTP; 3160 SIGEMPTYSET(sigpending); 3161 SIGADDSET(sigpending, SIGSTOP); 3162 } 3163 3164 SIG_FOREACH(sig, &sigpending) { 3165 switch (sigprocess(td, sig)) { 3166 case SIGSTATUS_HANDLE: 3167 return (sig); 3168 case SIGSTATUS_HANDLED: 3169 goto next; 3170 case SIGSTATUS_IGNORE: 3171 sigqueue_delete(&td->td_sigqueue, sig); 3172 sigqueue_delete(&p->p_sigqueue, sig); 3173 break; 3174 case SIGSTATUS_SBDRY_STOP: 3175 return (-1); 3176 } 3177 } 3178 next:; 3179 } 3180 } 3181 3182 void 3183 thread_stopped(struct proc *p) 3184 { 3185 int n; 3186 3187 PROC_LOCK_ASSERT(p, MA_OWNED); 3188 PROC_SLOCK_ASSERT(p, MA_OWNED); 3189 n = p->p_suspcount; 3190 if (p == curproc) 3191 n++; 3192 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 3193 PROC_SUNLOCK(p); 3194 p->p_flag &= ~P_WAITED; 3195 PROC_LOCK(p->p_pptr); 3196 childproc_stopped(p, (p->p_flag & P_TRACED) ? 3197 CLD_TRAPPED : CLD_STOPPED); 3198 PROC_UNLOCK(p->p_pptr); 3199 PROC_SLOCK(p); 3200 } 3201 } 3202 3203 /* 3204 * Take the action for the specified signal 3205 * from the current set of pending signals. 3206 */ 3207 int 3208 postsig(int sig) 3209 { 3210 struct thread *td; 3211 struct proc *p; 3212 struct sigacts *ps; 3213 sig_t action; 3214 ksiginfo_t ksi; 3215 sigset_t returnmask; 3216 3217 KASSERT(sig != 0, ("postsig")); 3218 3219 td = curthread; 3220 p = td->td_proc; 3221 PROC_LOCK_ASSERT(p, MA_OWNED); 3222 ps = p->p_sigacts; 3223 mtx_assert(&ps->ps_mtx, MA_OWNED); 3224 ksiginfo_init(&ksi); 3225 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3226 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3227 return (0); 3228 ksi.ksi_signo = sig; 3229 if (ksi.ksi_code == SI_TIMER) 3230 itimer_accept(p, ksi.ksi_timerid, &ksi); 3231 action = ps->ps_sigact[_SIG_IDX(sig)]; 3232 #ifdef KTRACE 3233 if (KTRPOINT(td, KTR_PSIG)) 3234 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3235 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3236 #endif 3237 3238 if (action == SIG_DFL) { 3239 /* 3240 * Default action, where the default is to kill 3241 * the process. (Other cases were ignored above.) 3242 */ 3243 mtx_unlock(&ps->ps_mtx); 3244 proc_td_siginfo_capture(td, &ksi.ksi_info); 3245 sigexit(td, sig); 3246 /* NOTREACHED */ 3247 } else { 3248 /* 3249 * If we get here, the signal must be caught. 3250 */ 3251 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3252 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3253 ("postsig action: blocked sig %d", sig)); 3254 3255 /* 3256 * Set the new mask value and also defer further 3257 * occurrences of this signal. 3258 * 3259 * Special case: user has done a sigsuspend. Here the 3260 * current mask is not of interest, but rather the 3261 * mask from before the sigsuspend is what we want 3262 * restored after the signal processing is completed. 3263 */ 3264 if (td->td_pflags & TDP_OLDMASK) { 3265 returnmask = td->td_oldsigmask; 3266 td->td_pflags &= ~TDP_OLDMASK; 3267 } else 3268 returnmask = td->td_sigmask; 3269 3270 if (p->p_sig == sig) { 3271 p->p_sig = 0; 3272 } 3273 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3274 postsig_done(sig, td, ps); 3275 } 3276 return (1); 3277 } 3278 3279 int 3280 sig_ast_checksusp(struct thread *td) 3281 { 3282 struct proc *p __diagused; 3283 int ret; 3284 3285 p = td->td_proc; 3286 PROC_LOCK_ASSERT(p, MA_OWNED); 3287 3288 if ((td->td_flags & TDF_NEEDSUSPCHK) == 0) 3289 return (0); 3290 3291 ret = thread_suspend_check(1); 3292 MPASS(ret == 0 || ret == EINTR || ret == ERESTART); 3293 return (ret); 3294 } 3295 3296 int 3297 sig_ast_needsigchk(struct thread *td) 3298 { 3299 struct proc *p; 3300 struct sigacts *ps; 3301 int ret, sig; 3302 3303 p = td->td_proc; 3304 PROC_LOCK_ASSERT(p, MA_OWNED); 3305 3306 if ((td->td_flags & TDF_NEEDSIGCHK) == 0) 3307 return (0); 3308 3309 ps = p->p_sigacts; 3310 mtx_lock(&ps->ps_mtx); 3311 sig = cursig(td); 3312 if (sig == -1) { 3313 mtx_unlock(&ps->ps_mtx); 3314 KASSERT((td->td_flags & TDF_SBDRY) != 0, ("lost TDF_SBDRY")); 3315 KASSERT(TD_SBDRY_INTR(td), 3316 ("lost TDF_SERESTART of TDF_SEINTR")); 3317 KASSERT((td->td_flags & (TDF_SEINTR | TDF_SERESTART)) != 3318 (TDF_SEINTR | TDF_SERESTART), 3319 ("both TDF_SEINTR and TDF_SERESTART")); 3320 ret = TD_SBDRY_ERRNO(td); 3321 } else if (sig != 0) { 3322 ret = SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : ERESTART; 3323 mtx_unlock(&ps->ps_mtx); 3324 } else { 3325 mtx_unlock(&ps->ps_mtx); 3326 ret = 0; 3327 } 3328 3329 /* 3330 * Do not go into sleep if this thread was the ptrace(2) 3331 * attach leader. cursig() consumed SIGSTOP from PT_ATTACH, 3332 * but we usually act on the signal by interrupting sleep, and 3333 * should do that here as well. 3334 */ 3335 if ((td->td_dbgflags & TDB_FSTP) != 0) { 3336 if (ret == 0) 3337 ret = EINTR; 3338 td->td_dbgflags &= ~TDB_FSTP; 3339 } 3340 3341 return (ret); 3342 } 3343 3344 int 3345 sig_intr(void) 3346 { 3347 struct thread *td; 3348 struct proc *p; 3349 int ret; 3350 3351 td = curthread; 3352 if ((td->td_flags & (TDF_NEEDSIGCHK | TDF_NEEDSUSPCHK)) == 0) 3353 return (0); 3354 3355 p = td->td_proc; 3356 3357 PROC_LOCK(p); 3358 ret = sig_ast_checksusp(td); 3359 if (ret == 0) 3360 ret = sig_ast_needsigchk(td); 3361 PROC_UNLOCK(p); 3362 return (ret); 3363 } 3364 3365 bool 3366 curproc_sigkilled(void) 3367 { 3368 struct thread *td; 3369 struct proc *p; 3370 struct sigacts *ps; 3371 bool res; 3372 3373 td = curthread; 3374 if ((td->td_flags & TDF_NEEDSIGCHK) == 0) 3375 return (false); 3376 3377 p = td->td_proc; 3378 PROC_LOCK(p); 3379 ps = p->p_sigacts; 3380 mtx_lock(&ps->ps_mtx); 3381 res = SIGISMEMBER(td->td_sigqueue.sq_signals, SIGKILL) || 3382 SIGISMEMBER(p->p_sigqueue.sq_signals, SIGKILL); 3383 mtx_unlock(&ps->ps_mtx); 3384 PROC_UNLOCK(p); 3385 return (res); 3386 } 3387 3388 void 3389 proc_wkilled(struct proc *p) 3390 { 3391 3392 PROC_LOCK_ASSERT(p, MA_OWNED); 3393 if ((p->p_flag & P_WKILLED) == 0) { 3394 p->p_flag |= P_WKILLED; 3395 /* 3396 * Notify swapper that there is a process to swap in. 3397 * The notification is racy, at worst it would take 10 3398 * seconds for the swapper process to notice. 3399 */ 3400 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3401 wakeup(&proc0); 3402 } 3403 } 3404 3405 /* 3406 * Kill the current process for stated reason. 3407 */ 3408 void 3409 killproc(struct proc *p, const char *why) 3410 { 3411 3412 PROC_LOCK_ASSERT(p, MA_OWNED); 3413 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3414 p->p_comm); 3415 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3416 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3417 p->p_ucred->cr_uid, why); 3418 proc_wkilled(p); 3419 kern_psignal(p, SIGKILL); 3420 } 3421 3422 /* 3423 * Force the current process to exit with the specified signal, dumping core 3424 * if appropriate. We bypass the normal tests for masked and caught signals, 3425 * allowing unrecoverable failures to terminate the process without changing 3426 * signal state. Mark the accounting record with the signal termination. 3427 * If dumping core, save the signal number for the debugger. Calls exit and 3428 * does not return. 3429 */ 3430 void 3431 sigexit(struct thread *td, int sig) 3432 { 3433 struct proc *p = td->td_proc; 3434 3435 PROC_LOCK_ASSERT(p, MA_OWNED); 3436 p->p_acflag |= AXSIG; 3437 /* 3438 * We must be single-threading to generate a core dump. This 3439 * ensures that the registers in the core file are up-to-date. 3440 * Also, the ELF dump handler assumes that the thread list doesn't 3441 * change out from under it. 3442 * 3443 * XXX If another thread attempts to single-thread before us 3444 * (e.g. via fork()), we won't get a dump at all. 3445 */ 3446 if ((sigprop(sig) & SIGPROP_CORE) && 3447 thread_single(p, SINGLE_NO_EXIT) == 0) { 3448 p->p_sig = sig; 3449 /* 3450 * Log signals which would cause core dumps 3451 * (Log as LOG_INFO to appease those who don't want 3452 * these messages.) 3453 * XXX : Todo, as well as euid, write out ruid too 3454 * Note that coredump() drops proc lock. 3455 */ 3456 if (coredump(td) == 0) 3457 sig |= WCOREFLAG; 3458 if (kern_logsigexit) 3459 log(LOG_INFO, 3460 "pid %d (%s), jid %d, uid %d: exited on " 3461 "signal %d%s\n", p->p_pid, p->p_comm, 3462 p->p_ucred->cr_prison->pr_id, 3463 td->td_ucred->cr_uid, 3464 sig &~ WCOREFLAG, 3465 sig & WCOREFLAG ? " (core dumped)" : ""); 3466 } else 3467 PROC_UNLOCK(p); 3468 exit1(td, 0, sig); 3469 /* NOTREACHED */ 3470 } 3471 3472 /* 3473 * Send queued SIGCHLD to parent when child process's state 3474 * is changed. 3475 */ 3476 static void 3477 sigparent(struct proc *p, int reason, int status) 3478 { 3479 PROC_LOCK_ASSERT(p, MA_OWNED); 3480 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3481 3482 if (p->p_ksi != NULL) { 3483 p->p_ksi->ksi_signo = SIGCHLD; 3484 p->p_ksi->ksi_code = reason; 3485 p->p_ksi->ksi_status = status; 3486 p->p_ksi->ksi_pid = p->p_pid; 3487 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3488 if (KSI_ONQ(p->p_ksi)) 3489 return; 3490 } 3491 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3492 } 3493 3494 static void 3495 childproc_jobstate(struct proc *p, int reason, int sig) 3496 { 3497 struct sigacts *ps; 3498 3499 PROC_LOCK_ASSERT(p, MA_OWNED); 3500 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3501 3502 /* 3503 * Wake up parent sleeping in kern_wait(), also send 3504 * SIGCHLD to parent, but SIGCHLD does not guarantee 3505 * that parent will awake, because parent may masked 3506 * the signal. 3507 */ 3508 p->p_pptr->p_flag |= P_STATCHILD; 3509 wakeup(p->p_pptr); 3510 3511 ps = p->p_pptr->p_sigacts; 3512 mtx_lock(&ps->ps_mtx); 3513 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3514 mtx_unlock(&ps->ps_mtx); 3515 sigparent(p, reason, sig); 3516 } else 3517 mtx_unlock(&ps->ps_mtx); 3518 } 3519 3520 void 3521 childproc_stopped(struct proc *p, int reason) 3522 { 3523 3524 childproc_jobstate(p, reason, p->p_xsig); 3525 } 3526 3527 void 3528 childproc_continued(struct proc *p) 3529 { 3530 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3531 } 3532 3533 void 3534 childproc_exited(struct proc *p) 3535 { 3536 int reason, status; 3537 3538 if (WCOREDUMP(p->p_xsig)) { 3539 reason = CLD_DUMPED; 3540 status = WTERMSIG(p->p_xsig); 3541 } else if (WIFSIGNALED(p->p_xsig)) { 3542 reason = CLD_KILLED; 3543 status = WTERMSIG(p->p_xsig); 3544 } else { 3545 reason = CLD_EXITED; 3546 status = p->p_xexit; 3547 } 3548 /* 3549 * XXX avoid calling wakeup(p->p_pptr), the work is 3550 * done in exit1(). 3551 */ 3552 sigparent(p, reason, status); 3553 } 3554 3555 #define MAX_NUM_CORE_FILES 100000 3556 #ifndef NUM_CORE_FILES 3557 #define NUM_CORE_FILES 5 3558 #endif 3559 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3560 static int num_cores = NUM_CORE_FILES; 3561 3562 static int 3563 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3564 { 3565 int error; 3566 int new_val; 3567 3568 new_val = num_cores; 3569 error = sysctl_handle_int(oidp, &new_val, 0, req); 3570 if (error != 0 || req->newptr == NULL) 3571 return (error); 3572 if (new_val > MAX_NUM_CORE_FILES) 3573 new_val = MAX_NUM_CORE_FILES; 3574 if (new_val < 0) 3575 new_val = 0; 3576 num_cores = new_val; 3577 return (0); 3578 } 3579 SYSCTL_PROC(_debug, OID_AUTO, ncores, 3580 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3581 sysctl_debug_num_cores_check, "I", 3582 "Maximum number of generated process corefiles while using index format"); 3583 3584 #define GZIP_SUFFIX ".gz" 3585 #define ZSTD_SUFFIX ".zst" 3586 3587 int compress_user_cores = 0; 3588 3589 static int 3590 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3591 { 3592 int error, val; 3593 3594 val = compress_user_cores; 3595 error = sysctl_handle_int(oidp, &val, 0, req); 3596 if (error != 0 || req->newptr == NULL) 3597 return (error); 3598 if (val != 0 && !compressor_avail(val)) 3599 return (EINVAL); 3600 compress_user_cores = val; 3601 return (error); 3602 } 3603 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, 3604 CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3605 sysctl_compress_user_cores, "I", 3606 "Enable compression of user corefiles (" 3607 __XSTRING(COMPRESS_GZIP) " = gzip, " 3608 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3609 3610 int compress_user_cores_level = 6; 3611 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3612 &compress_user_cores_level, 0, 3613 "Corefile compression level"); 3614 3615 /* 3616 * Protect the access to corefilename[] by allproc_lock. 3617 */ 3618 #define corefilename_lock allproc_lock 3619 3620 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3621 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3622 3623 static int 3624 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3625 { 3626 int error; 3627 3628 sx_xlock(&corefilename_lock); 3629 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3630 req); 3631 sx_xunlock(&corefilename_lock); 3632 3633 return (error); 3634 } 3635 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3636 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3637 "Process corefile name format string"); 3638 3639 static void 3640 vnode_close_locked(struct thread *td, struct vnode *vp) 3641 { 3642 3643 VOP_UNLOCK(vp); 3644 vn_close(vp, FWRITE, td->td_ucred, td); 3645 } 3646 3647 /* 3648 * If the core format has a %I in it, then we need to check 3649 * for existing corefiles before defining a name. 3650 * To do this we iterate over 0..ncores to find a 3651 * non-existing core file name to use. If all core files are 3652 * already used we choose the oldest one. 3653 */ 3654 static int 3655 corefile_open_last(struct thread *td, char *name, int indexpos, 3656 int indexlen, int ncores, struct vnode **vpp) 3657 { 3658 struct vnode *oldvp, *nextvp, *vp; 3659 struct vattr vattr; 3660 struct nameidata nd; 3661 int error, i, flags, oflags, cmode; 3662 char ch; 3663 struct timespec lasttime; 3664 3665 nextvp = oldvp = NULL; 3666 cmode = S_IRUSR | S_IWUSR; 3667 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3668 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3669 3670 for (i = 0; i < ncores; i++) { 3671 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3672 3673 ch = name[indexpos + indexlen]; 3674 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3675 i); 3676 name[indexpos + indexlen] = ch; 3677 3678 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3679 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3680 NULL); 3681 if (error != 0) 3682 break; 3683 3684 vp = nd.ni_vp; 3685 NDFREE(&nd, NDF_ONLY_PNBUF); 3686 if ((flags & O_CREAT) == O_CREAT) { 3687 nextvp = vp; 3688 break; 3689 } 3690 3691 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3692 if (error != 0) { 3693 vnode_close_locked(td, vp); 3694 break; 3695 } 3696 3697 if (oldvp == NULL || 3698 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3699 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3700 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3701 if (oldvp != NULL) 3702 vn_close(oldvp, FWRITE, td->td_ucred, td); 3703 oldvp = vp; 3704 VOP_UNLOCK(oldvp); 3705 lasttime = vattr.va_mtime; 3706 } else { 3707 vnode_close_locked(td, vp); 3708 } 3709 } 3710 3711 if (oldvp != NULL) { 3712 if (nextvp == NULL) { 3713 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3714 error = EFAULT; 3715 vn_close(oldvp, FWRITE, td->td_ucred, td); 3716 } else { 3717 nextvp = oldvp; 3718 error = vn_lock(nextvp, LK_EXCLUSIVE); 3719 if (error != 0) { 3720 vn_close(nextvp, FWRITE, td->td_ucred, 3721 td); 3722 nextvp = NULL; 3723 } 3724 } 3725 } else { 3726 vn_close(oldvp, FWRITE, td->td_ucred, td); 3727 } 3728 } 3729 if (error != 0) { 3730 if (nextvp != NULL) 3731 vnode_close_locked(td, oldvp); 3732 } else { 3733 *vpp = nextvp; 3734 } 3735 3736 return (error); 3737 } 3738 3739 /* 3740 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3741 * Expand the name described in corefilename, using name, uid, and pid 3742 * and open/create core file. 3743 * corefilename is a printf-like string, with three format specifiers: 3744 * %N name of process ("name") 3745 * %P process id (pid) 3746 * %U user id (uid) 3747 * For example, "%N.core" is the default; they can be disabled completely 3748 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3749 * This is controlled by the sysctl variable kern.corefile (see above). 3750 */ 3751 static int 3752 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3753 int compress, int signum, struct vnode **vpp, char **namep) 3754 { 3755 struct sbuf sb; 3756 struct nameidata nd; 3757 const char *format; 3758 char *hostname, *name; 3759 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3760 3761 hostname = NULL; 3762 format = corefilename; 3763 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3764 indexlen = 0; 3765 indexpos = -1; 3766 ncores = num_cores; 3767 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3768 sx_slock(&corefilename_lock); 3769 for (i = 0; format[i] != '\0'; i++) { 3770 switch (format[i]) { 3771 case '%': /* Format character */ 3772 i++; 3773 switch (format[i]) { 3774 case '%': 3775 sbuf_putc(&sb, '%'); 3776 break; 3777 case 'H': /* hostname */ 3778 if (hostname == NULL) { 3779 hostname = malloc(MAXHOSTNAMELEN, 3780 M_TEMP, M_WAITOK); 3781 } 3782 getcredhostname(td->td_ucred, hostname, 3783 MAXHOSTNAMELEN); 3784 sbuf_printf(&sb, "%s", hostname); 3785 break; 3786 case 'I': /* autoincrementing index */ 3787 if (indexpos != -1) { 3788 sbuf_printf(&sb, "%%I"); 3789 break; 3790 } 3791 3792 indexpos = sbuf_len(&sb); 3793 sbuf_printf(&sb, "%u", ncores - 1); 3794 indexlen = sbuf_len(&sb) - indexpos; 3795 break; 3796 case 'N': /* process name */ 3797 sbuf_printf(&sb, "%s", comm); 3798 break; 3799 case 'P': /* process id */ 3800 sbuf_printf(&sb, "%u", pid); 3801 break; 3802 case 'S': /* signal number */ 3803 sbuf_printf(&sb, "%i", signum); 3804 break; 3805 case 'U': /* user id */ 3806 sbuf_printf(&sb, "%u", uid); 3807 break; 3808 default: 3809 log(LOG_ERR, 3810 "Unknown format character %c in " 3811 "corename `%s'\n", format[i], format); 3812 break; 3813 } 3814 break; 3815 default: 3816 sbuf_putc(&sb, format[i]); 3817 break; 3818 } 3819 } 3820 sx_sunlock(&corefilename_lock); 3821 free(hostname, M_TEMP); 3822 if (compress == COMPRESS_GZIP) 3823 sbuf_printf(&sb, GZIP_SUFFIX); 3824 else if (compress == COMPRESS_ZSTD) 3825 sbuf_printf(&sb, ZSTD_SUFFIX); 3826 if (sbuf_error(&sb) != 0) { 3827 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3828 "long\n", (long)pid, comm, (u_long)uid); 3829 sbuf_delete(&sb); 3830 free(name, M_TEMP); 3831 return (ENOMEM); 3832 } 3833 sbuf_finish(&sb); 3834 sbuf_delete(&sb); 3835 3836 if (indexpos != -1) { 3837 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3838 vpp); 3839 if (error != 0) { 3840 log(LOG_ERR, 3841 "pid %d (%s), uid (%u): Path `%s' failed " 3842 "on initial open test, error = %d\n", 3843 pid, comm, uid, name, error); 3844 } 3845 } else { 3846 cmode = S_IRUSR | S_IWUSR; 3847 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3848 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3849 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3850 if ((td->td_proc->p_flag & P_SUGID) != 0) 3851 flags |= O_EXCL; 3852 3853 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3854 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3855 NULL); 3856 if (error == 0) { 3857 *vpp = nd.ni_vp; 3858 NDFREE(&nd, NDF_ONLY_PNBUF); 3859 } 3860 } 3861 3862 if (error != 0) { 3863 #ifdef AUDIT 3864 audit_proc_coredump(td, name, error); 3865 #endif 3866 free(name, M_TEMP); 3867 return (error); 3868 } 3869 *namep = name; 3870 return (0); 3871 } 3872 3873 /* 3874 * Dump a process' core. The main routine does some 3875 * policy checking, and creates the name of the coredump; 3876 * then it passes on a vnode and a size limit to the process-specific 3877 * coredump routine if there is one; if there _is not_ one, it returns 3878 * ENOSYS; otherwise it returns the error from the process-specific routine. 3879 */ 3880 3881 static int 3882 coredump(struct thread *td) 3883 { 3884 struct proc *p = td->td_proc; 3885 struct ucred *cred = td->td_ucred; 3886 struct vnode *vp; 3887 struct flock lf; 3888 struct vattr vattr; 3889 size_t fullpathsize; 3890 int error, error1, locked; 3891 char *name; /* name of corefile */ 3892 void *rl_cookie; 3893 off_t limit; 3894 char *fullpath, *freepath = NULL; 3895 struct sbuf *sb; 3896 3897 PROC_LOCK_ASSERT(p, MA_OWNED); 3898 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3899 3900 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3901 (p->p_flag2 & P2_NOTRACE) != 0) { 3902 PROC_UNLOCK(p); 3903 return (EFAULT); 3904 } 3905 3906 /* 3907 * Note that the bulk of limit checking is done after 3908 * the corefile is created. The exception is if the limit 3909 * for corefiles is 0, in which case we don't bother 3910 * creating the corefile at all. This layout means that 3911 * a corefile is truncated instead of not being created, 3912 * if it is larger than the limit. 3913 */ 3914 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3915 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3916 PROC_UNLOCK(p); 3917 return (EFBIG); 3918 } 3919 PROC_UNLOCK(p); 3920 3921 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3922 compress_user_cores, p->p_sig, &vp, &name); 3923 if (error != 0) 3924 return (error); 3925 3926 /* 3927 * Don't dump to non-regular files or files with links. 3928 * Do not dump into system files. Effective user must own the corefile. 3929 */ 3930 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3931 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 3932 vattr.va_uid != cred->cr_uid) { 3933 VOP_UNLOCK(vp); 3934 error = EFAULT; 3935 goto out; 3936 } 3937 3938 VOP_UNLOCK(vp); 3939 3940 /* Postpone other writers, including core dumps of other processes. */ 3941 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3942 3943 lf.l_whence = SEEK_SET; 3944 lf.l_start = 0; 3945 lf.l_len = 0; 3946 lf.l_type = F_WRLCK; 3947 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3948 3949 VATTR_NULL(&vattr); 3950 vattr.va_size = 0; 3951 if (set_core_nodump_flag) 3952 vattr.va_flags = UF_NODUMP; 3953 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3954 VOP_SETATTR(vp, &vattr, cred); 3955 VOP_UNLOCK(vp); 3956 PROC_LOCK(p); 3957 p->p_acflag |= ACORE; 3958 PROC_UNLOCK(p); 3959 3960 if (p->p_sysent->sv_coredump != NULL) { 3961 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3962 } else { 3963 error = ENOSYS; 3964 } 3965 3966 if (locked) { 3967 lf.l_type = F_UNLCK; 3968 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3969 } 3970 vn_rangelock_unlock(vp, rl_cookie); 3971 3972 /* 3973 * Notify the userland helper that a process triggered a core dump. 3974 * This allows the helper to run an automated debugging session. 3975 */ 3976 if (error != 0 || coredump_devctl == 0) 3977 goto out; 3978 sb = sbuf_new_auto(); 3979 if (vn_fullpath_global(p->p_textvp, &fullpath, &freepath) != 0) 3980 goto out2; 3981 sbuf_printf(sb, "comm=\""); 3982 devctl_safe_quote_sb(sb, fullpath); 3983 free(freepath, M_TEMP); 3984 sbuf_printf(sb, "\" core=\""); 3985 3986 /* 3987 * We can't lookup core file vp directly. When we're replacing a core, and 3988 * other random times, we flush the name cache, so it will fail. Instead, 3989 * if the path of the core is relative, add the current dir in front if it. 3990 */ 3991 if (name[0] != '/') { 3992 fullpathsize = MAXPATHLEN; 3993 freepath = malloc(fullpathsize, M_TEMP, M_WAITOK); 3994 if (vn_getcwd(freepath, &fullpath, &fullpathsize) != 0) { 3995 free(freepath, M_TEMP); 3996 goto out2; 3997 } 3998 devctl_safe_quote_sb(sb, fullpath); 3999 free(freepath, M_TEMP); 4000 sbuf_putc(sb, '/'); 4001 } 4002 devctl_safe_quote_sb(sb, name); 4003 sbuf_printf(sb, "\""); 4004 if (sbuf_finish(sb) == 0) 4005 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 4006 out2: 4007 sbuf_delete(sb); 4008 out: 4009 error1 = vn_close(vp, FWRITE, cred, td); 4010 if (error == 0) 4011 error = error1; 4012 #ifdef AUDIT 4013 audit_proc_coredump(td, name, error); 4014 #endif 4015 free(name, M_TEMP); 4016 return (error); 4017 } 4018 4019 /* 4020 * Nonexistent system call-- signal process (may want to handle it). Flag 4021 * error in case process won't see signal immediately (blocked or ignored). 4022 */ 4023 #ifndef _SYS_SYSPROTO_H_ 4024 struct nosys_args { 4025 int dummy; 4026 }; 4027 #endif 4028 /* ARGSUSED */ 4029 int 4030 nosys(struct thread *td, struct nosys_args *args) 4031 { 4032 struct proc *p; 4033 4034 p = td->td_proc; 4035 4036 PROC_LOCK(p); 4037 tdsignal(td, SIGSYS); 4038 PROC_UNLOCK(p); 4039 if (kern_lognosys == 1 || kern_lognosys == 3) { 4040 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 4041 td->td_sa.code); 4042 } 4043 if (kern_lognosys == 2 || kern_lognosys == 3 || 4044 (p->p_pid == 1 && (kern_lognosys & 3) == 0)) { 4045 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 4046 td->td_sa.code); 4047 } 4048 return (ENOSYS); 4049 } 4050 4051 /* 4052 * Send a SIGIO or SIGURG signal to a process or process group using stored 4053 * credentials rather than those of the current process. 4054 */ 4055 void 4056 pgsigio(struct sigio **sigiop, int sig, int checkctty) 4057 { 4058 ksiginfo_t ksi; 4059 struct sigio *sigio; 4060 4061 ksiginfo_init(&ksi); 4062 ksi.ksi_signo = sig; 4063 ksi.ksi_code = SI_KERNEL; 4064 4065 SIGIO_LOCK(); 4066 sigio = *sigiop; 4067 if (sigio == NULL) { 4068 SIGIO_UNLOCK(); 4069 return; 4070 } 4071 if (sigio->sio_pgid > 0) { 4072 PROC_LOCK(sigio->sio_proc); 4073 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 4074 kern_psignal(sigio->sio_proc, sig); 4075 PROC_UNLOCK(sigio->sio_proc); 4076 } else if (sigio->sio_pgid < 0) { 4077 struct proc *p; 4078 4079 PGRP_LOCK(sigio->sio_pgrp); 4080 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 4081 PROC_LOCK(p); 4082 if (p->p_state == PRS_NORMAL && 4083 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 4084 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 4085 kern_psignal(p, sig); 4086 PROC_UNLOCK(p); 4087 } 4088 PGRP_UNLOCK(sigio->sio_pgrp); 4089 } 4090 SIGIO_UNLOCK(); 4091 } 4092 4093 static int 4094 filt_sigattach(struct knote *kn) 4095 { 4096 struct proc *p = curproc; 4097 4098 kn->kn_ptr.p_proc = p; 4099 kn->kn_flags |= EV_CLEAR; /* automatically set */ 4100 4101 knlist_add(p->p_klist, kn, 0); 4102 4103 return (0); 4104 } 4105 4106 static void 4107 filt_sigdetach(struct knote *kn) 4108 { 4109 struct proc *p = kn->kn_ptr.p_proc; 4110 4111 knlist_remove(p->p_klist, kn, 0); 4112 } 4113 4114 /* 4115 * signal knotes are shared with proc knotes, so we apply a mask to 4116 * the hint in order to differentiate them from process hints. This 4117 * could be avoided by using a signal-specific knote list, but probably 4118 * isn't worth the trouble. 4119 */ 4120 static int 4121 filt_signal(struct knote *kn, long hint) 4122 { 4123 4124 if (hint & NOTE_SIGNAL) { 4125 hint &= ~NOTE_SIGNAL; 4126 4127 if (kn->kn_id == hint) 4128 kn->kn_data++; 4129 } 4130 return (kn->kn_data != 0); 4131 } 4132 4133 struct sigacts * 4134 sigacts_alloc(void) 4135 { 4136 struct sigacts *ps; 4137 4138 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 4139 refcount_init(&ps->ps_refcnt, 1); 4140 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 4141 return (ps); 4142 } 4143 4144 void 4145 sigacts_free(struct sigacts *ps) 4146 { 4147 4148 if (refcount_release(&ps->ps_refcnt) == 0) 4149 return; 4150 mtx_destroy(&ps->ps_mtx); 4151 free(ps, M_SUBPROC); 4152 } 4153 4154 struct sigacts * 4155 sigacts_hold(struct sigacts *ps) 4156 { 4157 4158 refcount_acquire(&ps->ps_refcnt); 4159 return (ps); 4160 } 4161 4162 void 4163 sigacts_copy(struct sigacts *dest, struct sigacts *src) 4164 { 4165 4166 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 4167 mtx_lock(&src->ps_mtx); 4168 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 4169 mtx_unlock(&src->ps_mtx); 4170 } 4171 4172 int 4173 sigacts_shared(struct sigacts *ps) 4174 { 4175 4176 return (ps->ps_refcnt > 1); 4177 } 4178 4179 void 4180 sig_drop_caught(struct proc *p) 4181 { 4182 int sig; 4183 struct sigacts *ps; 4184 4185 ps = p->p_sigacts; 4186 PROC_LOCK_ASSERT(p, MA_OWNED); 4187 mtx_assert(&ps->ps_mtx, MA_OWNED); 4188 SIG_FOREACH(sig, &ps->ps_sigcatch) { 4189 sigdflt(ps, sig); 4190 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 4191 sigqueue_delete_proc(p, sig); 4192 } 4193 } 4194 4195 static void 4196 sigfastblock_failed(struct thread *td, bool sendsig, bool write) 4197 { 4198 ksiginfo_t ksi; 4199 4200 /* 4201 * Prevent further fetches and SIGSEGVs, allowing thread to 4202 * issue syscalls despite corruption. 4203 */ 4204 sigfastblock_clear(td); 4205 4206 if (!sendsig) 4207 return; 4208 ksiginfo_init_trap(&ksi); 4209 ksi.ksi_signo = SIGSEGV; 4210 ksi.ksi_code = write ? SEGV_ACCERR : SEGV_MAPERR; 4211 ksi.ksi_addr = td->td_sigblock_ptr; 4212 trapsignal(td, &ksi); 4213 } 4214 4215 static bool 4216 sigfastblock_fetch_sig(struct thread *td, bool sendsig, uint32_t *valp) 4217 { 4218 uint32_t res; 4219 4220 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4221 return (true); 4222 if (fueword32((void *)td->td_sigblock_ptr, &res) == -1) { 4223 sigfastblock_failed(td, sendsig, false); 4224 return (false); 4225 } 4226 *valp = res; 4227 td->td_sigblock_val = res & ~SIGFASTBLOCK_FLAGS; 4228 return (true); 4229 } 4230 4231 static void 4232 sigfastblock_resched(struct thread *td, bool resched) 4233 { 4234 struct proc *p; 4235 4236 if (resched) { 4237 p = td->td_proc; 4238 PROC_LOCK(p); 4239 reschedule_signals(p, td->td_sigmask, 0); 4240 PROC_UNLOCK(p); 4241 } 4242 thread_lock(td); 4243 td->td_flags |= TDF_ASTPENDING | TDF_NEEDSIGCHK; 4244 thread_unlock(td); 4245 } 4246 4247 int 4248 sys_sigfastblock(struct thread *td, struct sigfastblock_args *uap) 4249 { 4250 struct proc *p; 4251 int error, res; 4252 uint32_t oldval; 4253 4254 error = 0; 4255 p = td->td_proc; 4256 switch (uap->cmd) { 4257 case SIGFASTBLOCK_SETPTR: 4258 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 4259 error = EBUSY; 4260 break; 4261 } 4262 if (((uintptr_t)(uap->ptr) & (sizeof(uint32_t) - 1)) != 0) { 4263 error = EINVAL; 4264 break; 4265 } 4266 td->td_pflags |= TDP_SIGFASTBLOCK; 4267 td->td_sigblock_ptr = uap->ptr; 4268 break; 4269 4270 case SIGFASTBLOCK_UNBLOCK: 4271 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4272 error = EINVAL; 4273 break; 4274 } 4275 4276 for (;;) { 4277 res = casueword32(td->td_sigblock_ptr, 4278 SIGFASTBLOCK_PEND, &oldval, 0); 4279 if (res == -1) { 4280 error = EFAULT; 4281 sigfastblock_failed(td, false, true); 4282 break; 4283 } 4284 if (res == 0) 4285 break; 4286 MPASS(res == 1); 4287 if (oldval != SIGFASTBLOCK_PEND) { 4288 error = EBUSY; 4289 break; 4290 } 4291 error = thread_check_susp(td, false); 4292 if (error != 0) 4293 break; 4294 } 4295 if (error != 0) 4296 break; 4297 4298 /* 4299 * td_sigblock_val is cleared there, but not on a 4300 * syscall exit. The end effect is that a single 4301 * interruptible sleep, while user sigblock word is 4302 * set, might return EINTR or ERESTART to usermode 4303 * without delivering signal. All further sleeps, 4304 * until userspace clears the word and does 4305 * sigfastblock(UNBLOCK), observe current word and no 4306 * longer get interrupted. It is slight 4307 * non-conformance, with alternative to have read the 4308 * sigblock word on each syscall entry. 4309 */ 4310 td->td_sigblock_val = 0; 4311 4312 /* 4313 * Rely on normal ast mechanism to deliver pending 4314 * signals to current thread. But notify others about 4315 * fake unblock. 4316 */ 4317 sigfastblock_resched(td, error == 0 && p->p_numthreads != 1); 4318 4319 break; 4320 4321 case SIGFASTBLOCK_UNSETPTR: 4322 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4323 error = EINVAL; 4324 break; 4325 } 4326 if (!sigfastblock_fetch_sig(td, false, &oldval)) { 4327 error = EFAULT; 4328 break; 4329 } 4330 if (oldval != 0 && oldval != SIGFASTBLOCK_PEND) { 4331 error = EBUSY; 4332 break; 4333 } 4334 sigfastblock_clear(td); 4335 break; 4336 4337 default: 4338 error = EINVAL; 4339 break; 4340 } 4341 return (error); 4342 } 4343 4344 void 4345 sigfastblock_clear(struct thread *td) 4346 { 4347 bool resched; 4348 4349 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4350 return; 4351 td->td_sigblock_val = 0; 4352 resched = (td->td_pflags & TDP_SIGFASTPENDING) != 0 || 4353 SIGPENDING(td); 4354 td->td_pflags &= ~(TDP_SIGFASTBLOCK | TDP_SIGFASTPENDING); 4355 sigfastblock_resched(td, resched); 4356 } 4357 4358 void 4359 sigfastblock_fetch(struct thread *td) 4360 { 4361 uint32_t val; 4362 4363 (void)sigfastblock_fetch_sig(td, true, &val); 4364 } 4365 4366 static void 4367 sigfastblock_setpend1(struct thread *td) 4368 { 4369 int res; 4370 uint32_t oldval; 4371 4372 if ((td->td_pflags & TDP_SIGFASTPENDING) == 0) 4373 return; 4374 res = fueword32((void *)td->td_sigblock_ptr, &oldval); 4375 if (res == -1) { 4376 sigfastblock_failed(td, true, false); 4377 return; 4378 } 4379 for (;;) { 4380 res = casueword32(td->td_sigblock_ptr, oldval, &oldval, 4381 oldval | SIGFASTBLOCK_PEND); 4382 if (res == -1) { 4383 sigfastblock_failed(td, true, true); 4384 return; 4385 } 4386 if (res == 0) { 4387 td->td_sigblock_val = oldval & ~SIGFASTBLOCK_FLAGS; 4388 td->td_pflags &= ~TDP_SIGFASTPENDING; 4389 break; 4390 } 4391 MPASS(res == 1); 4392 if (thread_check_susp(td, false) != 0) 4393 break; 4394 } 4395 } 4396 4397 void 4398 sigfastblock_setpend(struct thread *td, bool resched) 4399 { 4400 struct proc *p; 4401 4402 sigfastblock_setpend1(td); 4403 if (resched) { 4404 p = td->td_proc; 4405 PROC_LOCK(p); 4406 reschedule_signals(p, fastblock_mask, SIGPROCMASK_FASTBLK); 4407 PROC_UNLOCK(p); 4408 } 4409 }
Cache object: ab60c144317026c96ac87748c30da1b8
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