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_capsicum.h" 43 #include "opt_ktrace.h" 44 45 #include <sys/param.h> 46 #include <sys/capsicum.h> 47 #include <sys/ctype.h> 48 #include <sys/systm.h> 49 #include <sys/signalvar.h> 50 #include <sys/vnode.h> 51 #include <sys/acct.h> 52 #include <sys/capsicum.h> 53 #include <sys/compressor.h> 54 #include <sys/condvar.h> 55 #include <sys/devctl.h> 56 #include <sys/event.h> 57 #include <sys/fcntl.h> 58 #include <sys/imgact.h> 59 #include <sys/kernel.h> 60 #include <sys/ktr.h> 61 #include <sys/ktrace.h> 62 #include <sys/limits.h> 63 #include <sys/lock.h> 64 #include <sys/malloc.h> 65 #include <sys/mutex.h> 66 #include <sys/refcount.h> 67 #include <sys/namei.h> 68 #include <sys/proc.h> 69 #include <sys/procdesc.h> 70 #include <sys/ptrace.h> 71 #include <sys/posix4.h> 72 #include <sys/racct.h> 73 #include <sys/resourcevar.h> 74 #include <sys/sdt.h> 75 #include <sys/sbuf.h> 76 #include <sys/sleepqueue.h> 77 #include <sys/smp.h> 78 #include <sys/stat.h> 79 #include <sys/sx.h> 80 #include <sys/syscall.h> 81 #include <sys/syscallsubr.h> 82 #include <sys/sysctl.h> 83 #include <sys/sysent.h> 84 #include <sys/syslog.h> 85 #include <sys/sysproto.h> 86 #include <sys/timers.h> 87 #include <sys/unistd.h> 88 #include <sys/vmmeter.h> 89 #include <sys/wait.h> 90 #include <vm/vm.h> 91 #include <vm/vm_extern.h> 92 #include <vm/uma.h> 93 94 #include <sys/jail.h> 95 96 #include <machine/cpu.h> 97 98 #include <security/audit/audit.h> 99 100 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 101 102 SDT_PROVIDER_DECLARE(proc); 103 SDT_PROBE_DEFINE3(proc, , , signal__send, 104 "struct thread *", "struct proc *", "int"); 105 SDT_PROBE_DEFINE2(proc, , , signal__clear, 106 "int", "ksiginfo_t *"); 107 SDT_PROBE_DEFINE3(proc, , , signal__discard, 108 "struct thread *", "struct proc *", "int"); 109 110 static int coredump(struct thread *); 111 static int killpg1(struct thread *td, int sig, int pgid, int all, 112 ksiginfo_t *ksi); 113 static int issignal(struct thread *td); 114 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 115 static int sigprop(int sig); 116 static void tdsigwakeup(struct thread *, int, sig_t, int); 117 static int sig_suspend_threads(struct thread *, struct proc *, int); 118 static int filt_sigattach(struct knote *kn); 119 static void filt_sigdetach(struct knote *kn); 120 static int filt_signal(struct knote *kn, long hint); 121 static struct thread *sigtd(struct proc *p, int sig, bool fast_sigblock); 122 static void sigqueue_start(void); 123 124 static uma_zone_t ksiginfo_zone = NULL; 125 struct filterops sig_filtops = { 126 .f_isfd = 0, 127 .f_attach = filt_sigattach, 128 .f_detach = filt_sigdetach, 129 .f_event = filt_signal, 130 }; 131 132 static int kern_logsigexit = 1; 133 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 134 &kern_logsigexit, 0, 135 "Log processes quitting on abnormal signals to syslog(3)"); 136 137 static int kern_forcesigexit = 1; 138 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 139 &kern_forcesigexit, 0, "Force trap signal to be handled"); 140 141 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 142 "POSIX real time signal"); 143 144 static int max_pending_per_proc = 128; 145 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 146 &max_pending_per_proc, 0, "Max pending signals per proc"); 147 148 static int preallocate_siginfo = 1024; 149 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 150 &preallocate_siginfo, 0, "Preallocated signal memory size"); 151 152 static int signal_overflow = 0; 153 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 154 &signal_overflow, 0, "Number of signals overflew"); 155 156 static int signal_alloc_fail = 0; 157 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 158 &signal_alloc_fail, 0, "signals failed to be allocated"); 159 160 static int kern_lognosys = 0; 161 SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 162 "Log invalid syscalls"); 163 164 __read_frequently bool sigfastblock_fetch_always = false; 165 SYSCTL_BOOL(_kern, OID_AUTO, sigfastblock_fetch_always, CTLFLAG_RWTUN, 166 &sigfastblock_fetch_always, 0, 167 "Fetch sigfastblock word on each syscall entry for proper " 168 "blocking semantic"); 169 170 static bool kern_sig_discard_ign = true; 171 SYSCTL_BOOL(_kern, OID_AUTO, sig_discard_ign, CTLFLAG_RWTUN, 172 &kern_sig_discard_ign, 0, 173 "Discard ignored signals on delivery, otherwise queue them to " 174 "the target queue"); 175 176 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 177 178 /* 179 * Policy -- Can ucred cr1 send SIGIO to process cr2? 180 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 181 * in the right situations. 182 */ 183 #define CANSIGIO(cr1, cr2) \ 184 ((cr1)->cr_uid == 0 || \ 185 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 186 (cr1)->cr_uid == (cr2)->cr_ruid || \ 187 (cr1)->cr_ruid == (cr2)->cr_uid || \ 188 (cr1)->cr_uid == (cr2)->cr_uid) 189 190 static int sugid_coredump; 191 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 192 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 193 194 static int capmode_coredump; 195 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 196 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 197 198 static int do_coredump = 1; 199 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 200 &do_coredump, 0, "Enable/Disable coredumps"); 201 202 static int set_core_nodump_flag = 0; 203 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 204 0, "Enable setting the NODUMP flag on coredump files"); 205 206 static int coredump_devctl = 0; 207 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 208 0, "Generate a devctl notification when processes coredump"); 209 210 /* 211 * Signal properties and actions. 212 * The array below categorizes the signals and their default actions 213 * according to the following properties: 214 */ 215 #define SIGPROP_KILL 0x01 /* terminates process by default */ 216 #define SIGPROP_CORE 0x02 /* ditto and coredumps */ 217 #define SIGPROP_STOP 0x04 /* suspend process */ 218 #define SIGPROP_TTYSTOP 0x08 /* ditto, from tty */ 219 #define SIGPROP_IGNORE 0x10 /* ignore by default */ 220 #define SIGPROP_CONT 0x20 /* continue if suspended */ 221 222 static int sigproptbl[NSIG] = { 223 [SIGHUP] = SIGPROP_KILL, 224 [SIGINT] = SIGPROP_KILL, 225 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE, 226 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE, 227 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE, 228 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE, 229 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE, 230 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE, 231 [SIGKILL] = SIGPROP_KILL, 232 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE, 233 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE, 234 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE, 235 [SIGPIPE] = SIGPROP_KILL, 236 [SIGALRM] = SIGPROP_KILL, 237 [SIGTERM] = SIGPROP_KILL, 238 [SIGURG] = SIGPROP_IGNORE, 239 [SIGSTOP] = SIGPROP_STOP, 240 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP, 241 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT, 242 [SIGCHLD] = SIGPROP_IGNORE, 243 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP, 244 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP, 245 [SIGIO] = SIGPROP_IGNORE, 246 [SIGXCPU] = SIGPROP_KILL, 247 [SIGXFSZ] = SIGPROP_KILL, 248 [SIGVTALRM] = SIGPROP_KILL, 249 [SIGPROF] = SIGPROP_KILL, 250 [SIGWINCH] = SIGPROP_IGNORE, 251 [SIGINFO] = SIGPROP_IGNORE, 252 [SIGUSR1] = SIGPROP_KILL, 253 [SIGUSR2] = SIGPROP_KILL, 254 }; 255 256 #define _SIG_FOREACH_ADVANCE(i, set) ({ \ 257 int __found; \ 258 for (;;) { \ 259 if (__bits != 0) { \ 260 int __sig = ffs(__bits); \ 261 __bits &= ~(1u << (__sig - 1)); \ 262 sig = __i * sizeof((set)->__bits[0]) * NBBY + __sig; \ 263 __found = 1; \ 264 break; \ 265 } \ 266 if (++__i == _SIG_WORDS) { \ 267 __found = 0; \ 268 break; \ 269 } \ 270 __bits = (set)->__bits[__i]; \ 271 } \ 272 __found != 0; \ 273 }) 274 275 #define SIG_FOREACH(i, set) \ 276 for (int32_t __i = -1, __bits = 0; \ 277 _SIG_FOREACH_ADVANCE(i, set); ) \ 278 279 sigset_t fastblock_mask; 280 281 static void 282 sigqueue_start(void) 283 { 284 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 285 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 286 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 287 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 288 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 289 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 290 SIGFILLSET(fastblock_mask); 291 SIG_CANTMASK(fastblock_mask); 292 } 293 294 ksiginfo_t * 295 ksiginfo_alloc(int mwait) 296 { 297 MPASS(mwait == M_WAITOK || mwait == M_NOWAIT); 298 299 if (ksiginfo_zone == NULL) 300 return (NULL); 301 return (uma_zalloc(ksiginfo_zone, mwait | M_ZERO)); 302 } 303 304 void 305 ksiginfo_free(ksiginfo_t *ksi) 306 { 307 uma_zfree(ksiginfo_zone, ksi); 308 } 309 310 static __inline bool 311 ksiginfo_tryfree(ksiginfo_t *ksi) 312 { 313 if ((ksi->ksi_flags & KSI_EXT) == 0) { 314 uma_zfree(ksiginfo_zone, ksi); 315 return (true); 316 } 317 return (false); 318 } 319 320 void 321 sigqueue_init(sigqueue_t *list, struct proc *p) 322 { 323 SIGEMPTYSET(list->sq_signals); 324 SIGEMPTYSET(list->sq_kill); 325 SIGEMPTYSET(list->sq_ptrace); 326 TAILQ_INIT(&list->sq_list); 327 list->sq_proc = p; 328 list->sq_flags = SQ_INIT; 329 } 330 331 /* 332 * Get a signal's ksiginfo. 333 * Return: 334 * 0 - signal not found 335 * others - signal number 336 */ 337 static int 338 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 339 { 340 struct proc *p = sq->sq_proc; 341 struct ksiginfo *ksi, *next; 342 int count = 0; 343 344 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 345 346 if (!SIGISMEMBER(sq->sq_signals, signo)) 347 return (0); 348 349 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 350 count++; 351 SIGDELSET(sq->sq_ptrace, signo); 352 si->ksi_flags |= KSI_PTRACE; 353 } 354 if (SIGISMEMBER(sq->sq_kill, signo)) { 355 count++; 356 if (count == 1) 357 SIGDELSET(sq->sq_kill, signo); 358 } 359 360 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 361 if (ksi->ksi_signo == signo) { 362 if (count == 0) { 363 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 364 ksi->ksi_sigq = NULL; 365 ksiginfo_copy(ksi, si); 366 if (ksiginfo_tryfree(ksi) && p != NULL) 367 p->p_pendingcnt--; 368 } 369 if (++count > 1) 370 break; 371 } 372 } 373 374 if (count <= 1) 375 SIGDELSET(sq->sq_signals, signo); 376 si->ksi_signo = signo; 377 return (signo); 378 } 379 380 void 381 sigqueue_take(ksiginfo_t *ksi) 382 { 383 struct ksiginfo *kp; 384 struct proc *p; 385 sigqueue_t *sq; 386 387 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 388 return; 389 390 p = sq->sq_proc; 391 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 392 ksi->ksi_sigq = NULL; 393 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 394 p->p_pendingcnt--; 395 396 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 397 kp = TAILQ_NEXT(kp, ksi_link)) { 398 if (kp->ksi_signo == ksi->ksi_signo) 399 break; 400 } 401 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 402 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 403 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 404 } 405 406 static int 407 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 408 { 409 struct proc *p = sq->sq_proc; 410 struct ksiginfo *ksi; 411 int ret = 0; 412 413 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 414 415 /* 416 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 417 * for these signals. 418 */ 419 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 420 SIGADDSET(sq->sq_kill, signo); 421 goto out_set_bit; 422 } 423 424 /* directly insert the ksi, don't copy it */ 425 if (si->ksi_flags & KSI_INS) { 426 if (si->ksi_flags & KSI_HEAD) 427 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 428 else 429 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 430 si->ksi_sigq = sq; 431 goto out_set_bit; 432 } 433 434 if (__predict_false(ksiginfo_zone == NULL)) { 435 SIGADDSET(sq->sq_kill, signo); 436 goto out_set_bit; 437 } 438 439 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 440 signal_overflow++; 441 ret = EAGAIN; 442 } else if ((ksi = ksiginfo_alloc(M_NOWAIT)) == NULL) { 443 signal_alloc_fail++; 444 ret = EAGAIN; 445 } else { 446 if (p != NULL) 447 p->p_pendingcnt++; 448 ksiginfo_copy(si, ksi); 449 ksi->ksi_signo = signo; 450 if (si->ksi_flags & KSI_HEAD) 451 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 452 else 453 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 454 ksi->ksi_sigq = sq; 455 } 456 457 if (ret != 0) { 458 if ((si->ksi_flags & KSI_PTRACE) != 0) { 459 SIGADDSET(sq->sq_ptrace, signo); 460 ret = 0; 461 goto out_set_bit; 462 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 463 (si->ksi_flags & KSI_SIGQ) == 0) { 464 SIGADDSET(sq->sq_kill, signo); 465 ret = 0; 466 goto out_set_bit; 467 } 468 return (ret); 469 } 470 471 out_set_bit: 472 SIGADDSET(sq->sq_signals, signo); 473 return (ret); 474 } 475 476 void 477 sigqueue_flush(sigqueue_t *sq) 478 { 479 struct proc *p = sq->sq_proc; 480 ksiginfo_t *ksi; 481 482 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 483 484 if (p != NULL) 485 PROC_LOCK_ASSERT(p, MA_OWNED); 486 487 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 488 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 489 ksi->ksi_sigq = NULL; 490 if (ksiginfo_tryfree(ksi) && p != NULL) 491 p->p_pendingcnt--; 492 } 493 494 SIGEMPTYSET(sq->sq_signals); 495 SIGEMPTYSET(sq->sq_kill); 496 SIGEMPTYSET(sq->sq_ptrace); 497 } 498 499 static void 500 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 501 { 502 sigset_t tmp; 503 struct proc *p1, *p2; 504 ksiginfo_t *ksi, *next; 505 506 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 507 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 508 p1 = src->sq_proc; 509 p2 = dst->sq_proc; 510 /* Move siginfo to target list */ 511 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 512 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 513 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 514 if (p1 != NULL) 515 p1->p_pendingcnt--; 516 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 517 ksi->ksi_sigq = dst; 518 if (p2 != NULL) 519 p2->p_pendingcnt++; 520 } 521 } 522 523 /* Move pending bits to target list */ 524 tmp = src->sq_kill; 525 SIGSETAND(tmp, *set); 526 SIGSETOR(dst->sq_kill, tmp); 527 SIGSETNAND(src->sq_kill, tmp); 528 529 tmp = src->sq_ptrace; 530 SIGSETAND(tmp, *set); 531 SIGSETOR(dst->sq_ptrace, tmp); 532 SIGSETNAND(src->sq_ptrace, tmp); 533 534 tmp = src->sq_signals; 535 SIGSETAND(tmp, *set); 536 SIGSETOR(dst->sq_signals, tmp); 537 SIGSETNAND(src->sq_signals, tmp); 538 } 539 540 #if 0 541 static void 542 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 543 { 544 sigset_t set; 545 546 SIGEMPTYSET(set); 547 SIGADDSET(set, signo); 548 sigqueue_move_set(src, dst, &set); 549 } 550 #endif 551 552 static void 553 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 554 { 555 struct proc *p = sq->sq_proc; 556 ksiginfo_t *ksi, *next; 557 558 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 559 560 /* Remove siginfo queue */ 561 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 562 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 563 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 564 ksi->ksi_sigq = NULL; 565 if (ksiginfo_tryfree(ksi) && p != NULL) 566 p->p_pendingcnt--; 567 } 568 } 569 SIGSETNAND(sq->sq_kill, *set); 570 SIGSETNAND(sq->sq_ptrace, *set); 571 SIGSETNAND(sq->sq_signals, *set); 572 } 573 574 void 575 sigqueue_delete(sigqueue_t *sq, int signo) 576 { 577 sigset_t set; 578 579 SIGEMPTYSET(set); 580 SIGADDSET(set, signo); 581 sigqueue_delete_set(sq, &set); 582 } 583 584 /* Remove a set of signals for a process */ 585 static void 586 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 587 { 588 sigqueue_t worklist; 589 struct thread *td0; 590 591 PROC_LOCK_ASSERT(p, MA_OWNED); 592 593 sigqueue_init(&worklist, NULL); 594 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 595 596 FOREACH_THREAD_IN_PROC(p, td0) 597 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 598 599 sigqueue_flush(&worklist); 600 } 601 602 void 603 sigqueue_delete_proc(struct proc *p, int signo) 604 { 605 sigset_t set; 606 607 SIGEMPTYSET(set); 608 SIGADDSET(set, signo); 609 sigqueue_delete_set_proc(p, &set); 610 } 611 612 static void 613 sigqueue_delete_stopmask_proc(struct proc *p) 614 { 615 sigset_t set; 616 617 SIGEMPTYSET(set); 618 SIGADDSET(set, SIGSTOP); 619 SIGADDSET(set, SIGTSTP); 620 SIGADDSET(set, SIGTTIN); 621 SIGADDSET(set, SIGTTOU); 622 sigqueue_delete_set_proc(p, &set); 623 } 624 625 /* 626 * Determine signal that should be delivered to thread td, the current 627 * thread, 0 if none. If there is a pending stop signal with default 628 * action, the process stops in issignal(). 629 */ 630 int 631 cursig(struct thread *td) 632 { 633 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 634 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 635 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 636 return (SIGPENDING(td) ? issignal(td) : 0); 637 } 638 639 /* 640 * Arrange for ast() to handle unmasked pending signals on return to user 641 * mode. This must be called whenever a signal is added to td_sigqueue or 642 * unmasked in td_sigmask. 643 */ 644 void 645 signotify(struct thread *td) 646 { 647 648 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 649 650 if (SIGPENDING(td)) { 651 thread_lock(td); 652 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 653 thread_unlock(td); 654 } 655 } 656 657 /* 658 * Returns 1 (true) if altstack is configured for the thread, and the 659 * passed stack bottom address falls into the altstack range. Handles 660 * the 43 compat special case where the alt stack size is zero. 661 */ 662 int 663 sigonstack(size_t sp) 664 { 665 struct thread *td; 666 667 td = curthread; 668 if ((td->td_pflags & TDP_ALTSTACK) == 0) 669 return (0); 670 #if defined(COMPAT_43) 671 if (SV_PROC_FLAG(td->td_proc, SV_AOUT) && td->td_sigstk.ss_size == 0) 672 return ((td->td_sigstk.ss_flags & SS_ONSTACK) != 0); 673 #endif 674 return (sp >= (size_t)td->td_sigstk.ss_sp && 675 sp < td->td_sigstk.ss_size + (size_t)td->td_sigstk.ss_sp); 676 } 677 678 static __inline int 679 sigprop(int sig) 680 { 681 682 if (sig > 0 && sig < nitems(sigproptbl)) 683 return (sigproptbl[sig]); 684 return (0); 685 } 686 687 static bool 688 sigact_flag_test(const struct sigaction *act, int flag) 689 { 690 691 /* 692 * SA_SIGINFO is reset when signal disposition is set to 693 * ignore or default. Other flags are kept according to user 694 * settings. 695 */ 696 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 697 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 698 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 699 } 700 701 /* 702 * kern_sigaction 703 * sigaction 704 * freebsd4_sigaction 705 * osigaction 706 */ 707 int 708 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 709 struct sigaction *oact, int flags) 710 { 711 struct sigacts *ps; 712 struct proc *p = td->td_proc; 713 714 if (!_SIG_VALID(sig)) 715 return (EINVAL); 716 if (act != NULL && act->sa_handler != SIG_DFL && 717 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 718 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 719 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 720 return (EINVAL); 721 722 PROC_LOCK(p); 723 ps = p->p_sigacts; 724 mtx_lock(&ps->ps_mtx); 725 if (oact) { 726 memset(oact, 0, sizeof(*oact)); 727 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 728 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 729 oact->sa_flags |= SA_ONSTACK; 730 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 731 oact->sa_flags |= SA_RESTART; 732 if (SIGISMEMBER(ps->ps_sigreset, sig)) 733 oact->sa_flags |= SA_RESETHAND; 734 if (SIGISMEMBER(ps->ps_signodefer, sig)) 735 oact->sa_flags |= SA_NODEFER; 736 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 737 oact->sa_flags |= SA_SIGINFO; 738 oact->sa_sigaction = 739 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 740 } else 741 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 742 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 743 oact->sa_flags |= SA_NOCLDSTOP; 744 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 745 oact->sa_flags |= SA_NOCLDWAIT; 746 } 747 if (act) { 748 if ((sig == SIGKILL || sig == SIGSTOP) && 749 act->sa_handler != SIG_DFL) { 750 mtx_unlock(&ps->ps_mtx); 751 PROC_UNLOCK(p); 752 return (EINVAL); 753 } 754 755 /* 756 * Change setting atomically. 757 */ 758 759 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 760 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 761 if (sigact_flag_test(act, SA_SIGINFO)) { 762 ps->ps_sigact[_SIG_IDX(sig)] = 763 (__sighandler_t *)act->sa_sigaction; 764 SIGADDSET(ps->ps_siginfo, sig); 765 } else { 766 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 767 SIGDELSET(ps->ps_siginfo, sig); 768 } 769 if (!sigact_flag_test(act, SA_RESTART)) 770 SIGADDSET(ps->ps_sigintr, sig); 771 else 772 SIGDELSET(ps->ps_sigintr, sig); 773 if (sigact_flag_test(act, SA_ONSTACK)) 774 SIGADDSET(ps->ps_sigonstack, sig); 775 else 776 SIGDELSET(ps->ps_sigonstack, sig); 777 if (sigact_flag_test(act, SA_RESETHAND)) 778 SIGADDSET(ps->ps_sigreset, sig); 779 else 780 SIGDELSET(ps->ps_sigreset, sig); 781 if (sigact_flag_test(act, SA_NODEFER)) 782 SIGADDSET(ps->ps_signodefer, sig); 783 else 784 SIGDELSET(ps->ps_signodefer, sig); 785 if (sig == SIGCHLD) { 786 if (act->sa_flags & SA_NOCLDSTOP) 787 ps->ps_flag |= PS_NOCLDSTOP; 788 else 789 ps->ps_flag &= ~PS_NOCLDSTOP; 790 if (act->sa_flags & SA_NOCLDWAIT) { 791 /* 792 * Paranoia: since SA_NOCLDWAIT is implemented 793 * by reparenting the dying child to PID 1 (and 794 * trust it to reap the zombie), PID 1 itself 795 * is forbidden to set SA_NOCLDWAIT. 796 */ 797 if (p->p_pid == 1) 798 ps->ps_flag &= ~PS_NOCLDWAIT; 799 else 800 ps->ps_flag |= PS_NOCLDWAIT; 801 } else 802 ps->ps_flag &= ~PS_NOCLDWAIT; 803 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 804 ps->ps_flag |= PS_CLDSIGIGN; 805 else 806 ps->ps_flag &= ~PS_CLDSIGIGN; 807 } 808 /* 809 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 810 * and for signals set to SIG_DFL where the default is to 811 * ignore. However, don't put SIGCONT in ps_sigignore, as we 812 * have to restart the process. 813 */ 814 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 815 (sigprop(sig) & SIGPROP_IGNORE && 816 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 817 /* never to be seen again */ 818 sigqueue_delete_proc(p, sig); 819 if (sig != SIGCONT) 820 /* easier in psignal */ 821 SIGADDSET(ps->ps_sigignore, sig); 822 SIGDELSET(ps->ps_sigcatch, sig); 823 } else { 824 SIGDELSET(ps->ps_sigignore, sig); 825 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 826 SIGDELSET(ps->ps_sigcatch, sig); 827 else 828 SIGADDSET(ps->ps_sigcatch, sig); 829 } 830 #ifdef COMPAT_FREEBSD4 831 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 832 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 833 (flags & KSA_FREEBSD4) == 0) 834 SIGDELSET(ps->ps_freebsd4, sig); 835 else 836 SIGADDSET(ps->ps_freebsd4, sig); 837 #endif 838 #ifdef COMPAT_43 839 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 840 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 841 (flags & KSA_OSIGSET) == 0) 842 SIGDELSET(ps->ps_osigset, sig); 843 else 844 SIGADDSET(ps->ps_osigset, sig); 845 #endif 846 } 847 mtx_unlock(&ps->ps_mtx); 848 PROC_UNLOCK(p); 849 return (0); 850 } 851 852 #ifndef _SYS_SYSPROTO_H_ 853 struct sigaction_args { 854 int sig; 855 struct sigaction *act; 856 struct sigaction *oact; 857 }; 858 #endif 859 int 860 sys_sigaction(struct thread *td, struct sigaction_args *uap) 861 { 862 struct sigaction act, oact; 863 struct sigaction *actp, *oactp; 864 int error; 865 866 actp = (uap->act != NULL) ? &act : NULL; 867 oactp = (uap->oact != NULL) ? &oact : NULL; 868 if (actp) { 869 error = copyin(uap->act, actp, sizeof(act)); 870 if (error) 871 return (error); 872 } 873 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 874 if (oactp && !error) 875 error = copyout(oactp, uap->oact, sizeof(oact)); 876 return (error); 877 } 878 879 #ifdef COMPAT_FREEBSD4 880 #ifndef _SYS_SYSPROTO_H_ 881 struct freebsd4_sigaction_args { 882 int sig; 883 struct sigaction *act; 884 struct sigaction *oact; 885 }; 886 #endif 887 int 888 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 889 { 890 struct sigaction act, oact; 891 struct sigaction *actp, *oactp; 892 int error; 893 894 actp = (uap->act != NULL) ? &act : NULL; 895 oactp = (uap->oact != NULL) ? &oact : NULL; 896 if (actp) { 897 error = copyin(uap->act, actp, sizeof(act)); 898 if (error) 899 return (error); 900 } 901 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 902 if (oactp && !error) 903 error = copyout(oactp, uap->oact, sizeof(oact)); 904 return (error); 905 } 906 #endif /* COMAPT_FREEBSD4 */ 907 908 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 909 #ifndef _SYS_SYSPROTO_H_ 910 struct osigaction_args { 911 int signum; 912 struct osigaction *nsa; 913 struct osigaction *osa; 914 }; 915 #endif 916 int 917 osigaction(struct thread *td, struct osigaction_args *uap) 918 { 919 struct osigaction sa; 920 struct sigaction nsa, osa; 921 struct sigaction *nsap, *osap; 922 int error; 923 924 if (uap->signum <= 0 || uap->signum >= ONSIG) 925 return (EINVAL); 926 927 nsap = (uap->nsa != NULL) ? &nsa : NULL; 928 osap = (uap->osa != NULL) ? &osa : NULL; 929 930 if (nsap) { 931 error = copyin(uap->nsa, &sa, sizeof(sa)); 932 if (error) 933 return (error); 934 nsap->sa_handler = sa.sa_handler; 935 nsap->sa_flags = sa.sa_flags; 936 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 937 } 938 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 939 if (osap && !error) { 940 sa.sa_handler = osap->sa_handler; 941 sa.sa_flags = osap->sa_flags; 942 SIG2OSIG(osap->sa_mask, sa.sa_mask); 943 error = copyout(&sa, uap->osa, sizeof(sa)); 944 } 945 return (error); 946 } 947 948 #if !defined(__i386__) 949 /* Avoid replicating the same stub everywhere */ 950 int 951 osigreturn(struct thread *td, struct osigreturn_args *uap) 952 { 953 954 return (nosys(td, (struct nosys_args *)uap)); 955 } 956 #endif 957 #endif /* COMPAT_43 */ 958 959 /* 960 * Initialize signal state for process 0; 961 * set to ignore signals that are ignored by default. 962 */ 963 void 964 siginit(struct proc *p) 965 { 966 int i; 967 struct sigacts *ps; 968 969 PROC_LOCK(p); 970 ps = p->p_sigacts; 971 mtx_lock(&ps->ps_mtx); 972 for (i = 1; i <= NSIG; i++) { 973 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 974 SIGADDSET(ps->ps_sigignore, i); 975 } 976 } 977 mtx_unlock(&ps->ps_mtx); 978 PROC_UNLOCK(p); 979 } 980 981 /* 982 * Reset specified signal to the default disposition. 983 */ 984 static void 985 sigdflt(struct sigacts *ps, int sig) 986 { 987 988 mtx_assert(&ps->ps_mtx, MA_OWNED); 989 SIGDELSET(ps->ps_sigcatch, sig); 990 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 991 SIGADDSET(ps->ps_sigignore, sig); 992 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 993 SIGDELSET(ps->ps_siginfo, sig); 994 } 995 996 /* 997 * Reset signals for an exec of the specified process. 998 */ 999 void 1000 execsigs(struct proc *p) 1001 { 1002 sigset_t osigignore; 1003 struct sigacts *ps; 1004 int sig; 1005 struct thread *td; 1006 1007 /* 1008 * Reset caught signals. Held signals remain held 1009 * through td_sigmask (unless they were caught, 1010 * and are now ignored by default). 1011 */ 1012 PROC_LOCK_ASSERT(p, MA_OWNED); 1013 ps = p->p_sigacts; 1014 mtx_lock(&ps->ps_mtx); 1015 sig_drop_caught(p); 1016 1017 /* 1018 * As CloudABI processes cannot modify signal handlers, fully 1019 * reset all signals to their default behavior. Do ignore 1020 * SIGPIPE, as it would otherwise be impossible to recover from 1021 * writes to broken pipes and sockets. 1022 */ 1023 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 1024 osigignore = ps->ps_sigignore; 1025 SIG_FOREACH(sig, &osigignore) { 1026 if (sig != SIGPIPE) 1027 sigdflt(ps, sig); 1028 } 1029 SIGADDSET(ps->ps_sigignore, SIGPIPE); 1030 } 1031 1032 /* 1033 * Reset stack state to the user stack. 1034 * Clear set of signals caught on the signal stack. 1035 */ 1036 td = curthread; 1037 MPASS(td->td_proc == p); 1038 td->td_sigstk.ss_flags = SS_DISABLE; 1039 td->td_sigstk.ss_size = 0; 1040 td->td_sigstk.ss_sp = 0; 1041 td->td_pflags &= ~TDP_ALTSTACK; 1042 /* 1043 * Reset no zombies if child dies flag as Solaris does. 1044 */ 1045 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1046 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1047 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1048 mtx_unlock(&ps->ps_mtx); 1049 } 1050 1051 /* 1052 * kern_sigprocmask() 1053 * 1054 * Manipulate signal mask. 1055 */ 1056 int 1057 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1058 int flags) 1059 { 1060 sigset_t new_block, oset1; 1061 struct proc *p; 1062 int error; 1063 1064 p = td->td_proc; 1065 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1066 PROC_LOCK_ASSERT(p, MA_OWNED); 1067 else 1068 PROC_LOCK(p); 1069 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1070 ? MA_OWNED : MA_NOTOWNED); 1071 if (oset != NULL) 1072 *oset = td->td_sigmask; 1073 1074 error = 0; 1075 if (set != NULL) { 1076 switch (how) { 1077 case SIG_BLOCK: 1078 SIG_CANTMASK(*set); 1079 oset1 = td->td_sigmask; 1080 SIGSETOR(td->td_sigmask, *set); 1081 new_block = td->td_sigmask; 1082 SIGSETNAND(new_block, oset1); 1083 break; 1084 case SIG_UNBLOCK: 1085 SIGSETNAND(td->td_sigmask, *set); 1086 signotify(td); 1087 goto out; 1088 case SIG_SETMASK: 1089 SIG_CANTMASK(*set); 1090 oset1 = td->td_sigmask; 1091 if (flags & SIGPROCMASK_OLD) 1092 SIGSETLO(td->td_sigmask, *set); 1093 else 1094 td->td_sigmask = *set; 1095 new_block = td->td_sigmask; 1096 SIGSETNAND(new_block, oset1); 1097 signotify(td); 1098 break; 1099 default: 1100 error = EINVAL; 1101 goto out; 1102 } 1103 1104 /* 1105 * The new_block set contains signals that were not previously 1106 * blocked, but are blocked now. 1107 * 1108 * In case we block any signal that was not previously blocked 1109 * for td, and process has the signal pending, try to schedule 1110 * signal delivery to some thread that does not block the 1111 * signal, possibly waking it up. 1112 */ 1113 if (p->p_numthreads != 1) 1114 reschedule_signals(p, new_block, flags); 1115 } 1116 1117 out: 1118 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1119 PROC_UNLOCK(p); 1120 return (error); 1121 } 1122 1123 #ifndef _SYS_SYSPROTO_H_ 1124 struct sigprocmask_args { 1125 int how; 1126 const sigset_t *set; 1127 sigset_t *oset; 1128 }; 1129 #endif 1130 int 1131 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1132 { 1133 sigset_t set, oset; 1134 sigset_t *setp, *osetp; 1135 int error; 1136 1137 setp = (uap->set != NULL) ? &set : NULL; 1138 osetp = (uap->oset != NULL) ? &oset : NULL; 1139 if (setp) { 1140 error = copyin(uap->set, setp, sizeof(set)); 1141 if (error) 1142 return (error); 1143 } 1144 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1145 if (osetp && !error) { 1146 error = copyout(osetp, uap->oset, sizeof(oset)); 1147 } 1148 return (error); 1149 } 1150 1151 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1152 #ifndef _SYS_SYSPROTO_H_ 1153 struct osigprocmask_args { 1154 int how; 1155 osigset_t mask; 1156 }; 1157 #endif 1158 int 1159 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1160 { 1161 sigset_t set, oset; 1162 int error; 1163 1164 OSIG2SIG(uap->mask, set); 1165 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1166 SIG2OSIG(oset, td->td_retval[0]); 1167 return (error); 1168 } 1169 #endif /* COMPAT_43 */ 1170 1171 int 1172 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1173 { 1174 ksiginfo_t ksi; 1175 sigset_t set; 1176 int error; 1177 1178 error = copyin(uap->set, &set, sizeof(set)); 1179 if (error) { 1180 td->td_retval[0] = error; 1181 return (0); 1182 } 1183 1184 error = kern_sigtimedwait(td, set, &ksi, NULL); 1185 if (error) { 1186 /* 1187 * sigwait() function shall not return EINTR, but 1188 * the syscall does. Non-ancient libc provides the 1189 * wrapper which hides EINTR. Otherwise, EINTR return 1190 * is used by libthr to handle required cancellation 1191 * point in the sigwait(). 1192 */ 1193 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1194 return (ERESTART); 1195 td->td_retval[0] = error; 1196 return (0); 1197 } 1198 1199 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1200 td->td_retval[0] = error; 1201 return (0); 1202 } 1203 1204 int 1205 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1206 { 1207 struct timespec ts; 1208 struct timespec *timeout; 1209 sigset_t set; 1210 ksiginfo_t ksi; 1211 int error; 1212 1213 if (uap->timeout) { 1214 error = copyin(uap->timeout, &ts, sizeof(ts)); 1215 if (error) 1216 return (error); 1217 1218 timeout = &ts; 1219 } else 1220 timeout = NULL; 1221 1222 error = copyin(uap->set, &set, sizeof(set)); 1223 if (error) 1224 return (error); 1225 1226 error = kern_sigtimedwait(td, set, &ksi, timeout); 1227 if (error) 1228 return (error); 1229 1230 if (uap->info) 1231 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1232 1233 if (error == 0) 1234 td->td_retval[0] = ksi.ksi_signo; 1235 return (error); 1236 } 1237 1238 int 1239 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1240 { 1241 ksiginfo_t ksi; 1242 sigset_t set; 1243 int error; 1244 1245 error = copyin(uap->set, &set, sizeof(set)); 1246 if (error) 1247 return (error); 1248 1249 error = kern_sigtimedwait(td, set, &ksi, NULL); 1250 if (error) 1251 return (error); 1252 1253 if (uap->info) 1254 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1255 1256 if (error == 0) 1257 td->td_retval[0] = ksi.ksi_signo; 1258 return (error); 1259 } 1260 1261 static void 1262 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1263 { 1264 struct thread *thr; 1265 1266 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1267 if (thr == td) 1268 thr->td_si = *si; 1269 else 1270 thr->td_si.si_signo = 0; 1271 } 1272 } 1273 1274 int 1275 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1276 struct timespec *timeout) 1277 { 1278 struct sigacts *ps; 1279 sigset_t saved_mask, new_block; 1280 struct proc *p; 1281 int error, sig, timevalid = 0; 1282 sbintime_t sbt, precision, tsbt; 1283 struct timespec ts; 1284 bool traced; 1285 1286 p = td->td_proc; 1287 error = 0; 1288 traced = false; 1289 1290 /* Ensure the sigfastblock value is up to date. */ 1291 sigfastblock_fetch(td); 1292 1293 if (timeout != NULL) { 1294 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1295 timevalid = 1; 1296 ts = *timeout; 1297 if (ts.tv_sec < INT32_MAX / 2) { 1298 tsbt = tstosbt(ts); 1299 precision = tsbt; 1300 precision >>= tc_precexp; 1301 if (TIMESEL(&sbt, tsbt)) 1302 sbt += tc_tick_sbt; 1303 sbt += tsbt; 1304 } else 1305 precision = sbt = 0; 1306 } 1307 } else 1308 precision = sbt = 0; 1309 ksiginfo_init(ksi); 1310 /* Some signals can not be waited for. */ 1311 SIG_CANTMASK(waitset); 1312 ps = p->p_sigacts; 1313 PROC_LOCK(p); 1314 saved_mask = td->td_sigmask; 1315 SIGSETNAND(td->td_sigmask, waitset); 1316 if ((p->p_sysent->sv_flags & SV_SIG_DISCIGN) != 0 || 1317 !kern_sig_discard_ign) { 1318 thread_lock(td); 1319 td->td_flags |= TDF_SIGWAIT; 1320 thread_unlock(td); 1321 } 1322 for (;;) { 1323 mtx_lock(&ps->ps_mtx); 1324 sig = cursig(td); 1325 mtx_unlock(&ps->ps_mtx); 1326 KASSERT(sig >= 0, ("sig %d", sig)); 1327 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1328 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1329 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1330 error = 0; 1331 break; 1332 } 1333 } 1334 1335 if (error != 0) 1336 break; 1337 1338 /* 1339 * POSIX says this must be checked after looking for pending 1340 * signals. 1341 */ 1342 if (timeout != NULL && !timevalid) { 1343 error = EINVAL; 1344 break; 1345 } 1346 1347 if (traced) { 1348 error = EINTR; 1349 break; 1350 } 1351 1352 error = msleep_sbt(&p->p_sigacts, &p->p_mtx, PPAUSE | PCATCH, 1353 "sigwait", sbt, precision, C_ABSOLUTE); 1354 1355 /* The syscalls can not be restarted. */ 1356 if (error == ERESTART) 1357 error = EINTR; 1358 1359 /* 1360 * If PTRACE_SCE or PTRACE_SCX were set after 1361 * userspace entered the syscall, return spurious 1362 * EINTR after wait was done. Only do this as last 1363 * resort after rechecking for possible queued signals 1364 * and expired timeouts. 1365 */ 1366 if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0) 1367 traced = true; 1368 } 1369 thread_lock(td); 1370 td->td_flags &= ~TDF_SIGWAIT; 1371 thread_unlock(td); 1372 1373 new_block = saved_mask; 1374 SIGSETNAND(new_block, td->td_sigmask); 1375 td->td_sigmask = saved_mask; 1376 /* 1377 * Fewer signals can be delivered to us, reschedule signal 1378 * notification. 1379 */ 1380 if (p->p_numthreads != 1) 1381 reschedule_signals(p, new_block, 0); 1382 1383 if (error == 0) { 1384 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1385 1386 if (ksi->ksi_code == SI_TIMER) 1387 itimer_accept(p, ksi->ksi_timerid, ksi); 1388 1389 #ifdef KTRACE 1390 if (KTRPOINT(td, KTR_PSIG)) { 1391 sig_t action; 1392 1393 mtx_lock(&ps->ps_mtx); 1394 action = ps->ps_sigact[_SIG_IDX(sig)]; 1395 mtx_unlock(&ps->ps_mtx); 1396 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1397 } 1398 #endif 1399 if (sig == SIGKILL) { 1400 proc_td_siginfo_capture(td, &ksi->ksi_info); 1401 sigexit(td, sig); 1402 } 1403 } 1404 PROC_UNLOCK(p); 1405 return (error); 1406 } 1407 1408 #ifndef _SYS_SYSPROTO_H_ 1409 struct sigpending_args { 1410 sigset_t *set; 1411 }; 1412 #endif 1413 int 1414 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1415 { 1416 struct proc *p = td->td_proc; 1417 sigset_t pending; 1418 1419 PROC_LOCK(p); 1420 pending = p->p_sigqueue.sq_signals; 1421 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1422 PROC_UNLOCK(p); 1423 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1424 } 1425 1426 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1427 #ifndef _SYS_SYSPROTO_H_ 1428 struct osigpending_args { 1429 int dummy; 1430 }; 1431 #endif 1432 int 1433 osigpending(struct thread *td, struct osigpending_args *uap) 1434 { 1435 struct proc *p = td->td_proc; 1436 sigset_t pending; 1437 1438 PROC_LOCK(p); 1439 pending = p->p_sigqueue.sq_signals; 1440 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1441 PROC_UNLOCK(p); 1442 SIG2OSIG(pending, td->td_retval[0]); 1443 return (0); 1444 } 1445 #endif /* COMPAT_43 */ 1446 1447 #if defined(COMPAT_43) 1448 /* 1449 * Generalized interface signal handler, 4.3-compatible. 1450 */ 1451 #ifndef _SYS_SYSPROTO_H_ 1452 struct osigvec_args { 1453 int signum; 1454 struct sigvec *nsv; 1455 struct sigvec *osv; 1456 }; 1457 #endif 1458 /* ARGSUSED */ 1459 int 1460 osigvec(struct thread *td, struct osigvec_args *uap) 1461 { 1462 struct sigvec vec; 1463 struct sigaction nsa, osa; 1464 struct sigaction *nsap, *osap; 1465 int error; 1466 1467 if (uap->signum <= 0 || uap->signum >= ONSIG) 1468 return (EINVAL); 1469 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1470 osap = (uap->osv != NULL) ? &osa : NULL; 1471 if (nsap) { 1472 error = copyin(uap->nsv, &vec, sizeof(vec)); 1473 if (error) 1474 return (error); 1475 nsap->sa_handler = vec.sv_handler; 1476 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1477 nsap->sa_flags = vec.sv_flags; 1478 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1479 } 1480 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1481 if (osap && !error) { 1482 vec.sv_handler = osap->sa_handler; 1483 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1484 vec.sv_flags = osap->sa_flags; 1485 vec.sv_flags &= ~SA_NOCLDWAIT; 1486 vec.sv_flags ^= SA_RESTART; 1487 error = copyout(&vec, uap->osv, sizeof(vec)); 1488 } 1489 return (error); 1490 } 1491 1492 #ifndef _SYS_SYSPROTO_H_ 1493 struct osigblock_args { 1494 int mask; 1495 }; 1496 #endif 1497 int 1498 osigblock(struct thread *td, struct osigblock_args *uap) 1499 { 1500 sigset_t set, oset; 1501 1502 OSIG2SIG(uap->mask, set); 1503 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1504 SIG2OSIG(oset, td->td_retval[0]); 1505 return (0); 1506 } 1507 1508 #ifndef _SYS_SYSPROTO_H_ 1509 struct osigsetmask_args { 1510 int mask; 1511 }; 1512 #endif 1513 int 1514 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1515 { 1516 sigset_t set, oset; 1517 1518 OSIG2SIG(uap->mask, set); 1519 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1520 SIG2OSIG(oset, td->td_retval[0]); 1521 return (0); 1522 } 1523 #endif /* COMPAT_43 */ 1524 1525 /* 1526 * Suspend calling thread until signal, providing mask to be set in the 1527 * meantime. 1528 */ 1529 #ifndef _SYS_SYSPROTO_H_ 1530 struct sigsuspend_args { 1531 const sigset_t *sigmask; 1532 }; 1533 #endif 1534 /* ARGSUSED */ 1535 int 1536 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1537 { 1538 sigset_t mask; 1539 int error; 1540 1541 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1542 if (error) 1543 return (error); 1544 return (kern_sigsuspend(td, mask)); 1545 } 1546 1547 int 1548 kern_sigsuspend(struct thread *td, sigset_t mask) 1549 { 1550 struct proc *p = td->td_proc; 1551 int has_sig, sig; 1552 1553 /* Ensure the sigfastblock value is up to date. */ 1554 sigfastblock_fetch(td); 1555 1556 /* 1557 * When returning from sigsuspend, we want 1558 * the old mask to be restored after the 1559 * signal handler has finished. Thus, we 1560 * save it here and mark the sigacts structure 1561 * to indicate this. 1562 */ 1563 PROC_LOCK(p); 1564 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1565 SIGPROCMASK_PROC_LOCKED); 1566 td->td_pflags |= TDP_OLDMASK; 1567 1568 /* 1569 * Process signals now. Otherwise, we can get spurious wakeup 1570 * due to signal entered process queue, but delivered to other 1571 * thread. But sigsuspend should return only on signal 1572 * delivery. 1573 */ 1574 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1575 for (has_sig = 0; !has_sig;) { 1576 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1577 0) == 0) 1578 /* void */; 1579 thread_suspend_check(0); 1580 mtx_lock(&p->p_sigacts->ps_mtx); 1581 while ((sig = cursig(td)) != 0) { 1582 KASSERT(sig >= 0, ("sig %d", sig)); 1583 has_sig += postsig(sig); 1584 } 1585 mtx_unlock(&p->p_sigacts->ps_mtx); 1586 1587 /* 1588 * If PTRACE_SCE or PTRACE_SCX were set after 1589 * userspace entered the syscall, return spurious 1590 * EINTR. 1591 */ 1592 if ((p->p_ptevents & PTRACE_SYSCALL) != 0) 1593 has_sig += 1; 1594 } 1595 PROC_UNLOCK(p); 1596 td->td_errno = EINTR; 1597 td->td_pflags |= TDP_NERRNO; 1598 return (EJUSTRETURN); 1599 } 1600 1601 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1602 /* 1603 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1604 * convention: libc stub passes mask, not pointer, to save a copyin. 1605 */ 1606 #ifndef _SYS_SYSPROTO_H_ 1607 struct osigsuspend_args { 1608 osigset_t mask; 1609 }; 1610 #endif 1611 /* ARGSUSED */ 1612 int 1613 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1614 { 1615 sigset_t mask; 1616 1617 OSIG2SIG(uap->mask, mask); 1618 return (kern_sigsuspend(td, mask)); 1619 } 1620 #endif /* COMPAT_43 */ 1621 1622 #if defined(COMPAT_43) 1623 #ifndef _SYS_SYSPROTO_H_ 1624 struct osigstack_args { 1625 struct sigstack *nss; 1626 struct sigstack *oss; 1627 }; 1628 #endif 1629 /* ARGSUSED */ 1630 int 1631 osigstack(struct thread *td, struct osigstack_args *uap) 1632 { 1633 struct sigstack nss, oss; 1634 int error = 0; 1635 1636 if (uap->nss != NULL) { 1637 error = copyin(uap->nss, &nss, sizeof(nss)); 1638 if (error) 1639 return (error); 1640 } 1641 oss.ss_sp = td->td_sigstk.ss_sp; 1642 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1643 if (uap->nss != NULL) { 1644 td->td_sigstk.ss_sp = nss.ss_sp; 1645 td->td_sigstk.ss_size = 0; 1646 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1647 td->td_pflags |= TDP_ALTSTACK; 1648 } 1649 if (uap->oss != NULL) 1650 error = copyout(&oss, uap->oss, sizeof(oss)); 1651 1652 return (error); 1653 } 1654 #endif /* COMPAT_43 */ 1655 1656 #ifndef _SYS_SYSPROTO_H_ 1657 struct sigaltstack_args { 1658 stack_t *ss; 1659 stack_t *oss; 1660 }; 1661 #endif 1662 /* ARGSUSED */ 1663 int 1664 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1665 { 1666 stack_t ss, oss; 1667 int error; 1668 1669 if (uap->ss != NULL) { 1670 error = copyin(uap->ss, &ss, sizeof(ss)); 1671 if (error) 1672 return (error); 1673 } 1674 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1675 (uap->oss != NULL) ? &oss : NULL); 1676 if (error) 1677 return (error); 1678 if (uap->oss != NULL) 1679 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1680 return (error); 1681 } 1682 1683 int 1684 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1685 { 1686 struct proc *p = td->td_proc; 1687 int oonstack; 1688 1689 oonstack = sigonstack(cpu_getstack(td)); 1690 1691 if (oss != NULL) { 1692 *oss = td->td_sigstk; 1693 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1694 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1695 } 1696 1697 if (ss != NULL) { 1698 if (oonstack) 1699 return (EPERM); 1700 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1701 return (EINVAL); 1702 if (!(ss->ss_flags & SS_DISABLE)) { 1703 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1704 return (ENOMEM); 1705 1706 td->td_sigstk = *ss; 1707 td->td_pflags |= TDP_ALTSTACK; 1708 } else { 1709 td->td_pflags &= ~TDP_ALTSTACK; 1710 } 1711 } 1712 return (0); 1713 } 1714 1715 struct killpg1_ctx { 1716 struct thread *td; 1717 ksiginfo_t *ksi; 1718 int sig; 1719 bool sent; 1720 bool found; 1721 int ret; 1722 }; 1723 1724 static void 1725 killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg) 1726 { 1727 int err; 1728 1729 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 || 1730 (notself && p == arg->td->td_proc) || p->p_state == PRS_NEW) 1731 return; 1732 PROC_LOCK(p); 1733 err = p_cansignal(arg->td, p, arg->sig); 1734 if (err == 0 && arg->sig != 0) 1735 pksignal(p, arg->sig, arg->ksi); 1736 PROC_UNLOCK(p); 1737 if (err != ESRCH) 1738 arg->found = true; 1739 if (err == 0) 1740 arg->sent = true; 1741 else if (arg->ret == 0 && err != ESRCH && err != EPERM) 1742 arg->ret = err; 1743 } 1744 1745 /* 1746 * Common code for kill process group/broadcast kill. 1747 * cp is calling process. 1748 */ 1749 static int 1750 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1751 { 1752 struct proc *p; 1753 struct pgrp *pgrp; 1754 struct killpg1_ctx arg; 1755 1756 arg.td = td; 1757 arg.ksi = ksi; 1758 arg.sig = sig; 1759 arg.sent = false; 1760 arg.found = false; 1761 arg.ret = 0; 1762 if (all) { 1763 /* 1764 * broadcast 1765 */ 1766 sx_slock(&allproc_lock); 1767 FOREACH_PROC_IN_SYSTEM(p) { 1768 killpg1_sendsig(p, true, &arg); 1769 } 1770 sx_sunlock(&allproc_lock); 1771 } else { 1772 sx_slock(&proctree_lock); 1773 if (pgid == 0) { 1774 /* 1775 * zero pgid means send to my process group. 1776 */ 1777 pgrp = td->td_proc->p_pgrp; 1778 PGRP_LOCK(pgrp); 1779 } else { 1780 pgrp = pgfind(pgid); 1781 if (pgrp == NULL) { 1782 sx_sunlock(&proctree_lock); 1783 return (ESRCH); 1784 } 1785 } 1786 sx_sunlock(&proctree_lock); 1787 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1788 killpg1_sendsig(p, false, &arg); 1789 } 1790 PGRP_UNLOCK(pgrp); 1791 } 1792 MPASS(arg.ret != 0 || arg.found || !arg.sent); 1793 if (arg.ret == 0 && !arg.sent) 1794 arg.ret = arg.found ? EPERM : ESRCH; 1795 return (arg.ret); 1796 } 1797 1798 #ifndef _SYS_SYSPROTO_H_ 1799 struct kill_args { 1800 int pid; 1801 int signum; 1802 }; 1803 #endif 1804 /* ARGSUSED */ 1805 int 1806 sys_kill(struct thread *td, struct kill_args *uap) 1807 { 1808 1809 return (kern_kill(td, uap->pid, uap->signum)); 1810 } 1811 1812 int 1813 kern_kill(struct thread *td, pid_t pid, int signum) 1814 { 1815 ksiginfo_t ksi; 1816 struct proc *p; 1817 int error; 1818 1819 /* 1820 * A process in capability mode can send signals only to himself. 1821 * The main rationale behind this is that abort(3) is implemented as 1822 * kill(getpid(), SIGABRT). 1823 */ 1824 if (IN_CAPABILITY_MODE(td) && pid != td->td_proc->p_pid) 1825 return (ECAPMODE); 1826 1827 AUDIT_ARG_SIGNUM(signum); 1828 AUDIT_ARG_PID(pid); 1829 if ((u_int)signum > _SIG_MAXSIG) 1830 return (EINVAL); 1831 1832 ksiginfo_init(&ksi); 1833 ksi.ksi_signo = signum; 1834 ksi.ksi_code = SI_USER; 1835 ksi.ksi_pid = td->td_proc->p_pid; 1836 ksi.ksi_uid = td->td_ucred->cr_ruid; 1837 1838 if (pid > 0) { 1839 /* kill single process */ 1840 if ((p = pfind_any(pid)) == NULL) 1841 return (ESRCH); 1842 AUDIT_ARG_PROCESS(p); 1843 error = p_cansignal(td, p, signum); 1844 if (error == 0 && signum) 1845 pksignal(p, signum, &ksi); 1846 PROC_UNLOCK(p); 1847 return (error); 1848 } 1849 switch (pid) { 1850 case -1: /* broadcast signal */ 1851 return (killpg1(td, signum, 0, 1, &ksi)); 1852 case 0: /* signal own process group */ 1853 return (killpg1(td, signum, 0, 0, &ksi)); 1854 default: /* negative explicit process group */ 1855 return (killpg1(td, signum, -pid, 0, &ksi)); 1856 } 1857 /* NOTREACHED */ 1858 } 1859 1860 int 1861 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1862 { 1863 struct proc *p; 1864 int error; 1865 1866 AUDIT_ARG_SIGNUM(uap->signum); 1867 AUDIT_ARG_FD(uap->fd); 1868 if ((u_int)uap->signum > _SIG_MAXSIG) 1869 return (EINVAL); 1870 1871 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1872 if (error) 1873 return (error); 1874 AUDIT_ARG_PROCESS(p); 1875 error = p_cansignal(td, p, uap->signum); 1876 if (error == 0 && uap->signum) 1877 kern_psignal(p, uap->signum); 1878 PROC_UNLOCK(p); 1879 return (error); 1880 } 1881 1882 #if defined(COMPAT_43) 1883 #ifndef _SYS_SYSPROTO_H_ 1884 struct okillpg_args { 1885 int pgid; 1886 int signum; 1887 }; 1888 #endif 1889 /* ARGSUSED */ 1890 int 1891 okillpg(struct thread *td, struct okillpg_args *uap) 1892 { 1893 ksiginfo_t ksi; 1894 1895 AUDIT_ARG_SIGNUM(uap->signum); 1896 AUDIT_ARG_PID(uap->pgid); 1897 if ((u_int)uap->signum > _SIG_MAXSIG) 1898 return (EINVAL); 1899 1900 ksiginfo_init(&ksi); 1901 ksi.ksi_signo = uap->signum; 1902 ksi.ksi_code = SI_USER; 1903 ksi.ksi_pid = td->td_proc->p_pid; 1904 ksi.ksi_uid = td->td_ucred->cr_ruid; 1905 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1906 } 1907 #endif /* COMPAT_43 */ 1908 1909 #ifndef _SYS_SYSPROTO_H_ 1910 struct sigqueue_args { 1911 pid_t pid; 1912 int signum; 1913 /* union sigval */ void *value; 1914 }; 1915 #endif 1916 int 1917 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1918 { 1919 union sigval sv; 1920 1921 sv.sival_ptr = uap->value; 1922 1923 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1924 } 1925 1926 int 1927 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1928 { 1929 ksiginfo_t ksi; 1930 struct proc *p; 1931 int error; 1932 1933 if ((u_int)signum > _SIG_MAXSIG) 1934 return (EINVAL); 1935 1936 /* 1937 * Specification says sigqueue can only send signal to 1938 * single process. 1939 */ 1940 if (pid <= 0) 1941 return (EINVAL); 1942 1943 if ((p = pfind_any(pid)) == NULL) 1944 return (ESRCH); 1945 error = p_cansignal(td, p, signum); 1946 if (error == 0 && signum != 0) { 1947 ksiginfo_init(&ksi); 1948 ksi.ksi_flags = KSI_SIGQ; 1949 ksi.ksi_signo = signum; 1950 ksi.ksi_code = SI_QUEUE; 1951 ksi.ksi_pid = td->td_proc->p_pid; 1952 ksi.ksi_uid = td->td_ucred->cr_ruid; 1953 ksi.ksi_value = *value; 1954 error = pksignal(p, ksi.ksi_signo, &ksi); 1955 } 1956 PROC_UNLOCK(p); 1957 return (error); 1958 } 1959 1960 /* 1961 * Send a signal to a process group. 1962 */ 1963 void 1964 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1965 { 1966 struct pgrp *pgrp; 1967 1968 if (pgid != 0) { 1969 sx_slock(&proctree_lock); 1970 pgrp = pgfind(pgid); 1971 sx_sunlock(&proctree_lock); 1972 if (pgrp != NULL) { 1973 pgsignal(pgrp, sig, 0, ksi); 1974 PGRP_UNLOCK(pgrp); 1975 } 1976 } 1977 } 1978 1979 /* 1980 * Send a signal to a process group. If checktty is 1, 1981 * limit to members which have a controlling terminal. 1982 */ 1983 void 1984 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1985 { 1986 struct proc *p; 1987 1988 if (pgrp) { 1989 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1990 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1991 PROC_LOCK(p); 1992 if (p->p_state == PRS_NORMAL && 1993 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1994 pksignal(p, sig, ksi); 1995 PROC_UNLOCK(p); 1996 } 1997 } 1998 } 1999 2000 /* 2001 * Recalculate the signal mask and reset the signal disposition after 2002 * usermode frame for delivery is formed. Should be called after 2003 * mach-specific routine, because sysent->sv_sendsig() needs correct 2004 * ps_siginfo and signal mask. 2005 */ 2006 static void 2007 postsig_done(int sig, struct thread *td, struct sigacts *ps) 2008 { 2009 sigset_t mask; 2010 2011 mtx_assert(&ps->ps_mtx, MA_OWNED); 2012 td->td_ru.ru_nsignals++; 2013 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2014 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2015 SIGADDSET(mask, sig); 2016 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2017 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2018 if (SIGISMEMBER(ps->ps_sigreset, sig)) 2019 sigdflt(ps, sig); 2020 } 2021 2022 /* 2023 * Send a signal caused by a trap to the current thread. If it will be 2024 * caught immediately, deliver it with correct code. Otherwise, post it 2025 * normally. 2026 */ 2027 void 2028 trapsignal(struct thread *td, ksiginfo_t *ksi) 2029 { 2030 struct sigacts *ps; 2031 struct proc *p; 2032 sigset_t sigmask; 2033 int code, sig; 2034 2035 p = td->td_proc; 2036 sig = ksi->ksi_signo; 2037 code = ksi->ksi_code; 2038 KASSERT(_SIG_VALID(sig), ("invalid signal")); 2039 2040 sigfastblock_fetch(td); 2041 PROC_LOCK(p); 2042 ps = p->p_sigacts; 2043 mtx_lock(&ps->ps_mtx); 2044 sigmask = td->td_sigmask; 2045 if (td->td_sigblock_val != 0) 2046 SIGSETOR(sigmask, fastblock_mask); 2047 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 2048 !SIGISMEMBER(sigmask, sig)) { 2049 #ifdef KTRACE 2050 if (KTRPOINT(curthread, KTR_PSIG)) 2051 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 2052 &td->td_sigmask, code); 2053 #endif 2054 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 2055 ksi, &td->td_sigmask); 2056 postsig_done(sig, td, ps); 2057 mtx_unlock(&ps->ps_mtx); 2058 } else { 2059 /* 2060 * Avoid a possible infinite loop if the thread 2061 * masking the signal or process is ignoring the 2062 * signal. 2063 */ 2064 if (kern_forcesigexit && (SIGISMEMBER(sigmask, sig) || 2065 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2066 SIGDELSET(td->td_sigmask, sig); 2067 SIGDELSET(ps->ps_sigcatch, sig); 2068 SIGDELSET(ps->ps_sigignore, sig); 2069 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2070 td->td_pflags &= ~TDP_SIGFASTBLOCK; 2071 td->td_sigblock_val = 0; 2072 } 2073 mtx_unlock(&ps->ps_mtx); 2074 p->p_sig = sig; /* XXX to verify code */ 2075 tdsendsignal(p, td, sig, ksi); 2076 } 2077 PROC_UNLOCK(p); 2078 } 2079 2080 static struct thread * 2081 sigtd(struct proc *p, int sig, bool fast_sigblock) 2082 { 2083 struct thread *td, *signal_td; 2084 2085 PROC_LOCK_ASSERT(p, MA_OWNED); 2086 MPASS(!fast_sigblock || p == curproc); 2087 2088 /* 2089 * Check if current thread can handle the signal without 2090 * switching context to another thread. 2091 */ 2092 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig) && 2093 (!fast_sigblock || curthread->td_sigblock_val == 0)) 2094 return (curthread); 2095 signal_td = NULL; 2096 FOREACH_THREAD_IN_PROC(p, td) { 2097 if (!SIGISMEMBER(td->td_sigmask, sig) && (!fast_sigblock || 2098 td != curthread || td->td_sigblock_val == 0)) { 2099 signal_td = td; 2100 break; 2101 } 2102 } 2103 if (signal_td == NULL) 2104 signal_td = FIRST_THREAD_IN_PROC(p); 2105 return (signal_td); 2106 } 2107 2108 /* 2109 * Send the signal to the process. If the signal has an action, the action 2110 * is usually performed by the target process rather than the caller; we add 2111 * the signal to the set of pending signals for the process. 2112 * 2113 * Exceptions: 2114 * o When a stop signal is sent to a sleeping process that takes the 2115 * default action, the process is stopped without awakening it. 2116 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2117 * regardless of the signal action (eg, blocked or ignored). 2118 * 2119 * Other ignored signals are discarded immediately. 2120 * 2121 * NB: This function may be entered from the debugger via the "kill" DDB 2122 * command. There is little that can be done to mitigate the possibly messy 2123 * side effects of this unwise possibility. 2124 */ 2125 void 2126 kern_psignal(struct proc *p, int sig) 2127 { 2128 ksiginfo_t ksi; 2129 2130 ksiginfo_init(&ksi); 2131 ksi.ksi_signo = sig; 2132 ksi.ksi_code = SI_KERNEL; 2133 (void) tdsendsignal(p, NULL, sig, &ksi); 2134 } 2135 2136 int 2137 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2138 { 2139 2140 return (tdsendsignal(p, NULL, sig, ksi)); 2141 } 2142 2143 /* Utility function for finding a thread to send signal event to. */ 2144 int 2145 sigev_findtd(struct proc *p, struct sigevent *sigev, struct thread **ttd) 2146 { 2147 struct thread *td; 2148 2149 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2150 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2151 if (td == NULL) 2152 return (ESRCH); 2153 *ttd = td; 2154 } else { 2155 *ttd = NULL; 2156 PROC_LOCK(p); 2157 } 2158 return (0); 2159 } 2160 2161 void 2162 tdsignal(struct thread *td, int sig) 2163 { 2164 ksiginfo_t ksi; 2165 2166 ksiginfo_init(&ksi); 2167 ksi.ksi_signo = sig; 2168 ksi.ksi_code = SI_KERNEL; 2169 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2170 } 2171 2172 void 2173 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2174 { 2175 2176 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2177 } 2178 2179 static int 2180 sig_sleepq_abort(struct thread *td, int intrval) 2181 { 2182 THREAD_LOCK_ASSERT(td, MA_OWNED); 2183 2184 if (intrval == 0 && (td->td_flags & TDF_SIGWAIT) == 0) { 2185 thread_unlock(td); 2186 return (0); 2187 } 2188 return (sleepq_abort(td, intrval)); 2189 } 2190 2191 int 2192 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2193 { 2194 sig_t action; 2195 sigqueue_t *sigqueue; 2196 int prop; 2197 struct sigacts *ps; 2198 int intrval; 2199 int ret = 0; 2200 int wakeup_swapper; 2201 2202 MPASS(td == NULL || p == td->td_proc); 2203 PROC_LOCK_ASSERT(p, MA_OWNED); 2204 2205 if (!_SIG_VALID(sig)) 2206 panic("%s(): invalid signal %d", __func__, sig); 2207 2208 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2209 2210 /* 2211 * IEEE Std 1003.1-2001: return success when killing a zombie. 2212 */ 2213 if (p->p_state == PRS_ZOMBIE) { 2214 if (ksi != NULL && (ksi->ksi_flags & KSI_INS) != 0) 2215 ksiginfo_tryfree(ksi); 2216 return (ret); 2217 } 2218 2219 ps = p->p_sigacts; 2220 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2221 prop = sigprop(sig); 2222 2223 if (td == NULL) { 2224 td = sigtd(p, sig, false); 2225 sigqueue = &p->p_sigqueue; 2226 } else 2227 sigqueue = &td->td_sigqueue; 2228 2229 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2230 2231 /* 2232 * If the signal is being ignored, then we forget about it 2233 * immediately, except when the target process executes 2234 * sigwait(). (Note: we don't set SIGCONT in ps_sigignore, 2235 * and if it is set to SIG_IGN, action will be SIG_DFL here.) 2236 */ 2237 mtx_lock(&ps->ps_mtx); 2238 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2239 if (kern_sig_discard_ign && 2240 (p->p_sysent->sv_flags & SV_SIG_DISCIGN) == 0) { 2241 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2242 2243 mtx_unlock(&ps->ps_mtx); 2244 if (ksi != NULL && (ksi->ksi_flags & KSI_INS) != 0) 2245 ksiginfo_tryfree(ksi); 2246 return (ret); 2247 } else { 2248 action = SIG_CATCH; 2249 intrval = 0; 2250 } 2251 } else { 2252 if (SIGISMEMBER(td->td_sigmask, sig)) 2253 action = SIG_HOLD; 2254 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2255 action = SIG_CATCH; 2256 else 2257 action = SIG_DFL; 2258 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2259 intrval = EINTR; 2260 else 2261 intrval = ERESTART; 2262 } 2263 mtx_unlock(&ps->ps_mtx); 2264 2265 if (prop & SIGPROP_CONT) 2266 sigqueue_delete_stopmask_proc(p); 2267 else if (prop & SIGPROP_STOP) { 2268 /* 2269 * If sending a tty stop signal to a member of an orphaned 2270 * process group, discard the signal here if the action 2271 * is default; don't stop the process below if sleeping, 2272 * and don't clear any pending SIGCONT. 2273 */ 2274 if ((prop & SIGPROP_TTYSTOP) != 0 && 2275 (p->p_pgrp->pg_flags & PGRP_ORPHANED) != 0 && 2276 action == SIG_DFL) { 2277 if (ksi != NULL && (ksi->ksi_flags & KSI_INS) != 0) 2278 ksiginfo_tryfree(ksi); 2279 return (ret); 2280 } 2281 sigqueue_delete_proc(p, SIGCONT); 2282 if (p->p_flag & P_CONTINUED) { 2283 p->p_flag &= ~P_CONTINUED; 2284 PROC_LOCK(p->p_pptr); 2285 sigqueue_take(p->p_ksi); 2286 PROC_UNLOCK(p->p_pptr); 2287 } 2288 } 2289 2290 ret = sigqueue_add(sigqueue, sig, ksi); 2291 if (ret != 0) 2292 return (ret); 2293 signotify(td); 2294 /* 2295 * Defer further processing for signals which are held, 2296 * except that stopped processes must be continued by SIGCONT. 2297 */ 2298 if (action == SIG_HOLD && 2299 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2300 return (ret); 2301 2302 wakeup_swapper = 0; 2303 2304 /* 2305 * Some signals have a process-wide effect and a per-thread 2306 * component. Most processing occurs when the process next 2307 * tries to cross the user boundary, however there are some 2308 * times when processing needs to be done immediately, such as 2309 * waking up threads so that they can cross the user boundary. 2310 * We try to do the per-process part here. 2311 */ 2312 if (P_SHOULDSTOP(p)) { 2313 KASSERT(!(p->p_flag & P_WEXIT), 2314 ("signal to stopped but exiting process")); 2315 if (sig == SIGKILL) { 2316 /* 2317 * If traced process is already stopped, 2318 * then no further action is necessary. 2319 */ 2320 if (p->p_flag & P_TRACED) 2321 goto out; 2322 /* 2323 * SIGKILL sets process running. 2324 * It will die elsewhere. 2325 * All threads must be restarted. 2326 */ 2327 p->p_flag &= ~P_STOPPED_SIG; 2328 goto runfast; 2329 } 2330 2331 if (prop & SIGPROP_CONT) { 2332 /* 2333 * If traced process is already stopped, 2334 * then no further action is necessary. 2335 */ 2336 if (p->p_flag & P_TRACED) 2337 goto out; 2338 /* 2339 * If SIGCONT is default (or ignored), we continue the 2340 * process but don't leave the signal in sigqueue as 2341 * it has no further action. If SIGCONT is held, we 2342 * continue the process and leave the signal in 2343 * sigqueue. If the process catches SIGCONT, let it 2344 * handle the signal itself. If it isn't waiting on 2345 * an event, it goes back to run state. 2346 * Otherwise, process goes back to sleep state. 2347 */ 2348 p->p_flag &= ~P_STOPPED_SIG; 2349 PROC_SLOCK(p); 2350 if (p->p_numthreads == p->p_suspcount) { 2351 PROC_SUNLOCK(p); 2352 p->p_flag |= P_CONTINUED; 2353 p->p_xsig = SIGCONT; 2354 PROC_LOCK(p->p_pptr); 2355 childproc_continued(p); 2356 PROC_UNLOCK(p->p_pptr); 2357 PROC_SLOCK(p); 2358 } 2359 if (action == SIG_DFL) { 2360 thread_unsuspend(p); 2361 PROC_SUNLOCK(p); 2362 sigqueue_delete(sigqueue, sig); 2363 goto out_cont; 2364 } 2365 if (action == SIG_CATCH) { 2366 /* 2367 * The process wants to catch it so it needs 2368 * to run at least one thread, but which one? 2369 */ 2370 PROC_SUNLOCK(p); 2371 goto runfast; 2372 } 2373 /* 2374 * The signal is not ignored or caught. 2375 */ 2376 thread_unsuspend(p); 2377 PROC_SUNLOCK(p); 2378 goto out_cont; 2379 } 2380 2381 if (prop & SIGPROP_STOP) { 2382 /* 2383 * If traced process is already stopped, 2384 * then no further action is necessary. 2385 */ 2386 if (p->p_flag & P_TRACED) 2387 goto out; 2388 /* 2389 * Already stopped, don't need to stop again 2390 * (If we did the shell could get confused). 2391 * Just make sure the signal STOP bit set. 2392 */ 2393 p->p_flag |= P_STOPPED_SIG; 2394 sigqueue_delete(sigqueue, sig); 2395 goto out; 2396 } 2397 2398 /* 2399 * All other kinds of signals: 2400 * If a thread is sleeping interruptibly, simulate a 2401 * wakeup so that when it is continued it will be made 2402 * runnable and can look at the signal. However, don't make 2403 * the PROCESS runnable, leave it stopped. 2404 * It may run a bit until it hits a thread_suspend_check(). 2405 */ 2406 PROC_SLOCK(p); 2407 thread_lock(td); 2408 if (TD_CAN_ABORT(td)) 2409 wakeup_swapper = sig_sleepq_abort(td, intrval); 2410 else 2411 thread_unlock(td); 2412 PROC_SUNLOCK(p); 2413 goto out; 2414 /* 2415 * Mutexes are short lived. Threads waiting on them will 2416 * hit thread_suspend_check() soon. 2417 */ 2418 } else if (p->p_state == PRS_NORMAL) { 2419 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2420 tdsigwakeup(td, sig, action, intrval); 2421 goto out; 2422 } 2423 2424 MPASS(action == SIG_DFL); 2425 2426 if (prop & SIGPROP_STOP) { 2427 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2428 goto out; 2429 p->p_flag |= P_STOPPED_SIG; 2430 p->p_xsig = sig; 2431 PROC_SLOCK(p); 2432 wakeup_swapper = sig_suspend_threads(td, p, 1); 2433 if (p->p_numthreads == p->p_suspcount) { 2434 /* 2435 * only thread sending signal to another 2436 * process can reach here, if thread is sending 2437 * signal to its process, because thread does 2438 * not suspend itself here, p_numthreads 2439 * should never be equal to p_suspcount. 2440 */ 2441 thread_stopped(p); 2442 PROC_SUNLOCK(p); 2443 sigqueue_delete_proc(p, p->p_xsig); 2444 } else 2445 PROC_SUNLOCK(p); 2446 goto out; 2447 } 2448 } else { 2449 /* Not in "NORMAL" state. discard the signal. */ 2450 sigqueue_delete(sigqueue, sig); 2451 goto out; 2452 } 2453 2454 /* 2455 * The process is not stopped so we need to apply the signal to all the 2456 * running threads. 2457 */ 2458 runfast: 2459 tdsigwakeup(td, sig, action, intrval); 2460 PROC_SLOCK(p); 2461 thread_unsuspend(p); 2462 PROC_SUNLOCK(p); 2463 out_cont: 2464 itimer_proc_continue(p); 2465 kqtimer_proc_continue(p); 2466 out: 2467 /* If we jump here, proc slock should not be owned. */ 2468 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2469 if (wakeup_swapper) 2470 kick_proc0(); 2471 2472 return (ret); 2473 } 2474 2475 /* 2476 * The force of a signal has been directed against a single 2477 * thread. We need to see what we can do about knocking it 2478 * out of any sleep it may be in etc. 2479 */ 2480 static void 2481 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2482 { 2483 struct proc *p = td->td_proc; 2484 int prop, wakeup_swapper; 2485 2486 PROC_LOCK_ASSERT(p, MA_OWNED); 2487 prop = sigprop(sig); 2488 2489 PROC_SLOCK(p); 2490 thread_lock(td); 2491 /* 2492 * Bring the priority of a thread up if we want it to get 2493 * killed in this lifetime. Be careful to avoid bumping the 2494 * priority of the idle thread, since we still allow to signal 2495 * kernel processes. 2496 */ 2497 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2498 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2499 sched_prio(td, PUSER); 2500 if (TD_ON_SLEEPQ(td)) { 2501 /* 2502 * If thread is sleeping uninterruptibly 2503 * we can't interrupt the sleep... the signal will 2504 * be noticed when the process returns through 2505 * trap() or syscall(). 2506 */ 2507 if ((td->td_flags & TDF_SINTR) == 0) 2508 goto out; 2509 /* 2510 * If SIGCONT is default (or ignored) and process is 2511 * asleep, we are finished; the process should not 2512 * be awakened. 2513 */ 2514 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2515 thread_unlock(td); 2516 PROC_SUNLOCK(p); 2517 sigqueue_delete(&p->p_sigqueue, sig); 2518 /* 2519 * It may be on either list in this state. 2520 * Remove from both for now. 2521 */ 2522 sigqueue_delete(&td->td_sigqueue, sig); 2523 return; 2524 } 2525 2526 /* 2527 * Don't awaken a sleeping thread for SIGSTOP if the 2528 * STOP signal is deferred. 2529 */ 2530 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2531 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2532 goto out; 2533 2534 /* 2535 * Give low priority threads a better chance to run. 2536 */ 2537 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2538 sched_prio(td, PUSER); 2539 2540 wakeup_swapper = sig_sleepq_abort(td, intrval); 2541 PROC_SUNLOCK(p); 2542 if (wakeup_swapper) 2543 kick_proc0(); 2544 return; 2545 } 2546 2547 /* 2548 * Other states do nothing with the signal immediately, 2549 * other than kicking ourselves if we are running. 2550 * It will either never be noticed, or noticed very soon. 2551 */ 2552 #ifdef SMP 2553 if (TD_IS_RUNNING(td) && td != curthread) 2554 forward_signal(td); 2555 #endif 2556 2557 out: 2558 PROC_SUNLOCK(p); 2559 thread_unlock(td); 2560 } 2561 2562 static void 2563 ptrace_coredumpreq(struct thread *td, struct proc *p, 2564 struct thr_coredump_req *tcq) 2565 { 2566 void *rl_cookie; 2567 2568 if (p->p_sysent->sv_coredump == NULL) { 2569 tcq->tc_error = ENOSYS; 2570 return; 2571 } 2572 2573 rl_cookie = vn_rangelock_wlock(tcq->tc_vp, 0, OFF_MAX); 2574 tcq->tc_error = p->p_sysent->sv_coredump(td, tcq->tc_vp, 2575 tcq->tc_limit, tcq->tc_flags); 2576 vn_rangelock_unlock(tcq->tc_vp, rl_cookie); 2577 } 2578 2579 static void 2580 ptrace_syscallreq(struct thread *td, struct proc *p, 2581 struct thr_syscall_req *tsr) 2582 { 2583 struct sysentvec *sv; 2584 struct sysent *se; 2585 register_t rv_saved[2]; 2586 int error, nerror; 2587 int sc; 2588 bool audited, sy_thr_static; 2589 2590 sv = p->p_sysent; 2591 if (sv->sv_table == NULL || sv->sv_size < tsr->ts_sa.code) { 2592 tsr->ts_ret.sr_error = ENOSYS; 2593 return; 2594 } 2595 2596 sc = tsr->ts_sa.code; 2597 if (sc == SYS_syscall || sc == SYS___syscall) { 2598 sc = tsr->ts_sa.args[0]; 2599 memmove(&tsr->ts_sa.args[0], &tsr->ts_sa.args[1], 2600 sizeof(register_t) * (tsr->ts_nargs - 1)); 2601 } 2602 2603 tsr->ts_sa.callp = se = &sv->sv_table[sc]; 2604 2605 VM_CNT_INC(v_syscall); 2606 td->td_pticks = 0; 2607 if (__predict_false(td->td_cowgen != atomic_load_int( 2608 &td->td_proc->p_cowgen))) 2609 thread_cow_update(td); 2610 2611 #ifdef CAPABILITY_MODE 2612 if (IN_CAPABILITY_MODE(td) && (se->sy_flags & SYF_CAPENABLED) == 0) { 2613 tsr->ts_ret.sr_error = ECAPMODE; 2614 return; 2615 } 2616 #endif 2617 2618 sy_thr_static = (se->sy_thrcnt & SY_THR_STATIC) != 0; 2619 audited = AUDIT_SYSCALL_ENTER(sc, td) != 0; 2620 2621 if (!sy_thr_static) { 2622 error = syscall_thread_enter(td, se); 2623 if (error != 0) { 2624 tsr->ts_ret.sr_error = error; 2625 return; 2626 } 2627 } 2628 2629 rv_saved[0] = td->td_retval[0]; 2630 rv_saved[1] = td->td_retval[1]; 2631 nerror = td->td_errno; 2632 td->td_retval[0] = 0; 2633 td->td_retval[1] = 0; 2634 2635 #ifdef KDTRACE_HOOKS 2636 if (se->sy_entry != 0) 2637 (*systrace_probe_func)(&tsr->ts_sa, SYSTRACE_ENTRY, 0); 2638 #endif 2639 tsr->ts_ret.sr_error = se->sy_call(td, tsr->ts_sa.args); 2640 #ifdef KDTRACE_HOOKS 2641 if (se->sy_return != 0) 2642 (*systrace_probe_func)(&tsr->ts_sa, SYSTRACE_RETURN, 2643 tsr->ts_ret.sr_error != 0 ? -1 : td->td_retval[0]); 2644 #endif 2645 2646 tsr->ts_ret.sr_retval[0] = td->td_retval[0]; 2647 tsr->ts_ret.sr_retval[1] = td->td_retval[1]; 2648 td->td_retval[0] = rv_saved[0]; 2649 td->td_retval[1] = rv_saved[1]; 2650 td->td_errno = nerror; 2651 2652 if (audited) 2653 AUDIT_SYSCALL_EXIT(error, td); 2654 if (!sy_thr_static) 2655 syscall_thread_exit(td, se); 2656 } 2657 2658 static void 2659 ptrace_remotereq(struct thread *td, int flag) 2660 { 2661 struct proc *p; 2662 2663 MPASS(td == curthread); 2664 p = td->td_proc; 2665 PROC_LOCK_ASSERT(p, MA_OWNED); 2666 if ((td->td_dbgflags & flag) == 0) 2667 return; 2668 KASSERT((p->p_flag & P_STOPPED_TRACE) != 0, ("not stopped")); 2669 KASSERT(td->td_remotereq != NULL, ("td_remotereq is NULL")); 2670 2671 PROC_UNLOCK(p); 2672 switch (flag) { 2673 case TDB_COREDUMPREQ: 2674 ptrace_coredumpreq(td, p, td->td_remotereq); 2675 break; 2676 case TDB_SCREMOTEREQ: 2677 ptrace_syscallreq(td, p, td->td_remotereq); 2678 break; 2679 default: 2680 __unreachable(); 2681 } 2682 PROC_LOCK(p); 2683 2684 MPASS((td->td_dbgflags & flag) != 0); 2685 td->td_dbgflags &= ~flag; 2686 td->td_remotereq = NULL; 2687 wakeup(p); 2688 } 2689 2690 static int 2691 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2692 { 2693 struct thread *td2; 2694 int wakeup_swapper; 2695 2696 PROC_LOCK_ASSERT(p, MA_OWNED); 2697 PROC_SLOCK_ASSERT(p, MA_OWNED); 2698 MPASS(sending || td == curthread); 2699 2700 wakeup_swapper = 0; 2701 FOREACH_THREAD_IN_PROC(p, td2) { 2702 thread_lock(td2); 2703 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2704 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2705 (td2->td_flags & TDF_SINTR)) { 2706 if (td2->td_flags & TDF_SBDRY) { 2707 /* 2708 * Once a thread is asleep with 2709 * TDF_SBDRY and without TDF_SERESTART 2710 * or TDF_SEINTR set, it should never 2711 * become suspended due to this check. 2712 */ 2713 KASSERT(!TD_IS_SUSPENDED(td2), 2714 ("thread with deferred stops suspended")); 2715 if (TD_SBDRY_INTR(td2)) { 2716 wakeup_swapper |= sleepq_abort(td2, 2717 TD_SBDRY_ERRNO(td2)); 2718 continue; 2719 } 2720 } else if (!TD_IS_SUSPENDED(td2)) 2721 thread_suspend_one(td2); 2722 } else if (!TD_IS_SUSPENDED(td2)) { 2723 if (sending || td != td2) 2724 td2->td_flags |= TDF_ASTPENDING; 2725 #ifdef SMP 2726 if (TD_IS_RUNNING(td2) && td2 != td) 2727 forward_signal(td2); 2728 #endif 2729 } 2730 thread_unlock(td2); 2731 } 2732 return (wakeup_swapper); 2733 } 2734 2735 /* 2736 * Stop the process for an event deemed interesting to the debugger. If si is 2737 * non-NULL, this is a signal exchange; the new signal requested by the 2738 * debugger will be returned for handling. If si is NULL, this is some other 2739 * type of interesting event. The debugger may request a signal be delivered in 2740 * that case as well, however it will be deferred until it can be handled. 2741 */ 2742 int 2743 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2744 { 2745 struct proc *p = td->td_proc; 2746 struct thread *td2; 2747 ksiginfo_t ksi; 2748 2749 PROC_LOCK_ASSERT(p, MA_OWNED); 2750 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2751 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2752 &p->p_mtx.lock_object, "Stopping for traced signal"); 2753 2754 td->td_xsig = sig; 2755 2756 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2757 td->td_dbgflags |= TDB_XSIG; 2758 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2759 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2760 PROC_SLOCK(p); 2761 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2762 if (P_KILLED(p)) { 2763 /* 2764 * Ensure that, if we've been PT_KILLed, the 2765 * exit status reflects that. Another thread 2766 * may also be in ptracestop(), having just 2767 * received the SIGKILL, but this thread was 2768 * unsuspended first. 2769 */ 2770 td->td_dbgflags &= ~TDB_XSIG; 2771 td->td_xsig = SIGKILL; 2772 p->p_ptevents = 0; 2773 break; 2774 } 2775 if (p->p_flag & P_SINGLE_EXIT && 2776 !(td->td_dbgflags & TDB_EXIT)) { 2777 /* 2778 * Ignore ptrace stops except for thread exit 2779 * events when the process exits. 2780 */ 2781 td->td_dbgflags &= ~TDB_XSIG; 2782 PROC_SUNLOCK(p); 2783 return (0); 2784 } 2785 2786 /* 2787 * Make wait(2) work. Ensure that right after the 2788 * attach, the thread which was decided to become the 2789 * leader of attach gets reported to the waiter. 2790 * Otherwise, just avoid overwriting another thread's 2791 * assignment to p_xthread. If another thread has 2792 * already set p_xthread, the current thread will get 2793 * a chance to report itself upon the next iteration. 2794 */ 2795 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2796 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2797 p->p_xthread == NULL)) { 2798 p->p_xsig = sig; 2799 p->p_xthread = td; 2800 2801 /* 2802 * If we are on sleepqueue already, 2803 * let sleepqueue code decide if it 2804 * needs to go sleep after attach. 2805 */ 2806 if (td->td_wchan == NULL) 2807 td->td_dbgflags &= ~TDB_FSTP; 2808 2809 p->p_flag2 &= ~P2_PTRACE_FSTP; 2810 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2811 sig_suspend_threads(td, p, 0); 2812 } 2813 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2814 td->td_dbgflags &= ~TDB_STOPATFORK; 2815 } 2816 stopme: 2817 td->td_dbgflags |= TDB_SSWITCH; 2818 thread_suspend_switch(td, p); 2819 td->td_dbgflags &= ~TDB_SSWITCH; 2820 if ((td->td_dbgflags & (TDB_COREDUMPREQ | 2821 TDB_SCREMOTEREQ)) != 0) { 2822 MPASS((td->td_dbgflags & (TDB_COREDUMPREQ | 2823 TDB_SCREMOTEREQ)) != 2824 (TDB_COREDUMPREQ | TDB_SCREMOTEREQ)); 2825 PROC_SUNLOCK(p); 2826 ptrace_remotereq(td, td->td_dbgflags & 2827 (TDB_COREDUMPREQ | TDB_SCREMOTEREQ)); 2828 PROC_SLOCK(p); 2829 goto stopme; 2830 } 2831 if (p->p_xthread == td) 2832 p->p_xthread = NULL; 2833 if (!(p->p_flag & P_TRACED)) 2834 break; 2835 if (td->td_dbgflags & TDB_SUSPEND) { 2836 if (p->p_flag & P_SINGLE_EXIT) 2837 break; 2838 goto stopme; 2839 } 2840 } 2841 PROC_SUNLOCK(p); 2842 } 2843 2844 if (si != NULL && sig == td->td_xsig) { 2845 /* Parent wants us to take the original signal unchanged. */ 2846 si->ksi_flags |= KSI_HEAD; 2847 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2848 si->ksi_signo = 0; 2849 } else if (td->td_xsig != 0) { 2850 /* 2851 * If parent wants us to take a new signal, then it will leave 2852 * it in td->td_xsig; otherwise we just look for signals again. 2853 */ 2854 ksiginfo_init(&ksi); 2855 ksi.ksi_signo = td->td_xsig; 2856 ksi.ksi_flags |= KSI_PTRACE; 2857 td2 = sigtd(p, td->td_xsig, false); 2858 tdsendsignal(p, td2, td->td_xsig, &ksi); 2859 if (td != td2) 2860 return (0); 2861 } 2862 2863 return (td->td_xsig); 2864 } 2865 2866 static void 2867 reschedule_signals(struct proc *p, sigset_t block, int flags) 2868 { 2869 struct sigacts *ps; 2870 struct thread *td; 2871 int sig; 2872 bool fastblk, pslocked; 2873 2874 PROC_LOCK_ASSERT(p, MA_OWNED); 2875 ps = p->p_sigacts; 2876 pslocked = (flags & SIGPROCMASK_PS_LOCKED) != 0; 2877 mtx_assert(&ps->ps_mtx, pslocked ? MA_OWNED : MA_NOTOWNED); 2878 if (SIGISEMPTY(p->p_siglist)) 2879 return; 2880 SIGSETAND(block, p->p_siglist); 2881 fastblk = (flags & SIGPROCMASK_FASTBLK) != 0; 2882 SIG_FOREACH(sig, &block) { 2883 td = sigtd(p, sig, fastblk); 2884 2885 /* 2886 * If sigtd() selected us despite sigfastblock is 2887 * blocking, do not activate AST or wake us, to avoid 2888 * loop in AST handler. 2889 */ 2890 if (fastblk && td == curthread) 2891 continue; 2892 2893 signotify(td); 2894 if (!pslocked) 2895 mtx_lock(&ps->ps_mtx); 2896 if (p->p_flag & P_TRACED || 2897 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2898 !SIGISMEMBER(td->td_sigmask, sig))) { 2899 tdsigwakeup(td, sig, SIG_CATCH, 2900 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2901 ERESTART)); 2902 } 2903 if (!pslocked) 2904 mtx_unlock(&ps->ps_mtx); 2905 } 2906 } 2907 2908 void 2909 tdsigcleanup(struct thread *td) 2910 { 2911 struct proc *p; 2912 sigset_t unblocked; 2913 2914 p = td->td_proc; 2915 PROC_LOCK_ASSERT(p, MA_OWNED); 2916 2917 sigqueue_flush(&td->td_sigqueue); 2918 if (p->p_numthreads == 1) 2919 return; 2920 2921 /* 2922 * Since we cannot handle signals, notify signal post code 2923 * about this by filling the sigmask. 2924 * 2925 * Also, if needed, wake up thread(s) that do not block the 2926 * same signals as the exiting thread, since the thread might 2927 * have been selected for delivery and woken up. 2928 */ 2929 SIGFILLSET(unblocked); 2930 SIGSETNAND(unblocked, td->td_sigmask); 2931 SIGFILLSET(td->td_sigmask); 2932 reschedule_signals(p, unblocked, 0); 2933 2934 } 2935 2936 static int 2937 sigdeferstop_curr_flags(int cflags) 2938 { 2939 2940 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2941 (cflags & TDF_SBDRY) != 0); 2942 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2943 } 2944 2945 /* 2946 * Defer the delivery of SIGSTOP for the current thread, according to 2947 * the requested mode. Returns previous flags, which must be restored 2948 * by sigallowstop(). 2949 * 2950 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2951 * cleared by the current thread, which allow the lock-less read-only 2952 * accesses below. 2953 */ 2954 int 2955 sigdeferstop_impl(int mode) 2956 { 2957 struct thread *td; 2958 int cflags, nflags; 2959 2960 td = curthread; 2961 cflags = sigdeferstop_curr_flags(td->td_flags); 2962 switch (mode) { 2963 case SIGDEFERSTOP_NOP: 2964 nflags = cflags; 2965 break; 2966 case SIGDEFERSTOP_OFF: 2967 nflags = 0; 2968 break; 2969 case SIGDEFERSTOP_SILENT: 2970 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2971 break; 2972 case SIGDEFERSTOP_EINTR: 2973 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2974 break; 2975 case SIGDEFERSTOP_ERESTART: 2976 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2977 break; 2978 default: 2979 panic("sigdeferstop: invalid mode %x", mode); 2980 break; 2981 } 2982 if (cflags == nflags) 2983 return (SIGDEFERSTOP_VAL_NCHG); 2984 thread_lock(td); 2985 td->td_flags = (td->td_flags & ~cflags) | nflags; 2986 thread_unlock(td); 2987 return (cflags); 2988 } 2989 2990 /* 2991 * Restores the STOP handling mode, typically permitting the delivery 2992 * of SIGSTOP for the current thread. This does not immediately 2993 * suspend if a stop was posted. Instead, the thread will suspend 2994 * either via ast() or a subsequent interruptible sleep. 2995 */ 2996 void 2997 sigallowstop_impl(int prev) 2998 { 2999 struct thread *td; 3000 int cflags; 3001 3002 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 3003 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 3004 ("sigallowstop: incorrect previous mode %x", prev)); 3005 td = curthread; 3006 cflags = sigdeferstop_curr_flags(td->td_flags); 3007 if (cflags != prev) { 3008 thread_lock(td); 3009 td->td_flags = (td->td_flags & ~cflags) | prev; 3010 thread_unlock(td); 3011 } 3012 } 3013 3014 enum sigstatus { 3015 SIGSTATUS_HANDLE, 3016 SIGSTATUS_HANDLED, 3017 SIGSTATUS_IGNORE, 3018 SIGSTATUS_SBDRY_STOP, 3019 }; 3020 3021 /* 3022 * The thread has signal "sig" pending. Figure out what to do with it: 3023 * 3024 * _HANDLE -> the caller should handle the signal 3025 * _HANDLED -> handled internally, reload pending signal set 3026 * _IGNORE -> ignored, remove from the set of pending signals and try the 3027 * next pending signal 3028 * _SBDRY_STOP -> the signal should stop the thread but this is not 3029 * permitted in the current context 3030 */ 3031 static enum sigstatus 3032 sigprocess(struct thread *td, int sig) 3033 { 3034 struct proc *p; 3035 struct sigacts *ps; 3036 struct sigqueue *queue; 3037 ksiginfo_t ksi; 3038 int prop; 3039 3040 KASSERT(_SIG_VALID(sig), ("%s: invalid signal %d", __func__, sig)); 3041 3042 p = td->td_proc; 3043 ps = p->p_sigacts; 3044 mtx_assert(&ps->ps_mtx, MA_OWNED); 3045 PROC_LOCK_ASSERT(p, MA_OWNED); 3046 3047 /* 3048 * We should allow pending but ignored signals below 3049 * if there is sigwait() active, or P_TRACED was 3050 * on when they were posted. 3051 */ 3052 if (SIGISMEMBER(ps->ps_sigignore, sig) && 3053 (p->p_flag & P_TRACED) == 0 && 3054 (td->td_flags & TDF_SIGWAIT) == 0) { 3055 return (SIGSTATUS_IGNORE); 3056 } 3057 3058 /* 3059 * If the process is going to single-thread mode to prepare 3060 * for exit, there is no sense in delivering any signal 3061 * to usermode. Another important consequence is that 3062 * msleep(..., PCATCH, ...) now is only interruptible by a 3063 * suspend request. 3064 */ 3065 if ((p->p_flag2 & P2_WEXIT) != 0) 3066 return (SIGSTATUS_IGNORE); 3067 3068 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 3069 /* 3070 * If traced, always stop. 3071 * Remove old signal from queue before the stop. 3072 * XXX shrug off debugger, it causes siginfo to 3073 * be thrown away. 3074 */ 3075 queue = &td->td_sigqueue; 3076 ksiginfo_init(&ksi); 3077 if (sigqueue_get(queue, sig, &ksi) == 0) { 3078 queue = &p->p_sigqueue; 3079 sigqueue_get(queue, sig, &ksi); 3080 } 3081 td->td_si = ksi.ksi_info; 3082 3083 mtx_unlock(&ps->ps_mtx); 3084 sig = ptracestop(td, sig, &ksi); 3085 mtx_lock(&ps->ps_mtx); 3086 3087 td->td_si.si_signo = 0; 3088 3089 /* 3090 * Keep looking if the debugger discarded or 3091 * replaced the signal. 3092 */ 3093 if (sig == 0) 3094 return (SIGSTATUS_HANDLED); 3095 3096 /* 3097 * If the signal became masked, re-queue it. 3098 */ 3099 if (SIGISMEMBER(td->td_sigmask, sig)) { 3100 ksi.ksi_flags |= KSI_HEAD; 3101 sigqueue_add(&p->p_sigqueue, sig, &ksi); 3102 return (SIGSTATUS_HANDLED); 3103 } 3104 3105 /* 3106 * If the traced bit got turned off, requeue the signal and 3107 * reload the set of pending signals. This ensures that p_sig* 3108 * and p_sigact are consistent. 3109 */ 3110 if ((p->p_flag & P_TRACED) == 0) { 3111 if ((ksi.ksi_flags & KSI_PTRACE) == 0) { 3112 ksi.ksi_flags |= KSI_HEAD; 3113 sigqueue_add(queue, sig, &ksi); 3114 } 3115 return (SIGSTATUS_HANDLED); 3116 } 3117 } 3118 3119 /* 3120 * Decide whether the signal should be returned. 3121 * Return the signal's number, or fall through 3122 * to clear it from the pending mask. 3123 */ 3124 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 3125 case (intptr_t)SIG_DFL: 3126 /* 3127 * Don't take default actions on system processes. 3128 */ 3129 if (p->p_pid <= 1) { 3130 #ifdef DIAGNOSTIC 3131 /* 3132 * Are you sure you want to ignore SIGSEGV 3133 * in init? XXX 3134 */ 3135 printf("Process (pid %lu) got signal %d\n", 3136 (u_long)p->p_pid, sig); 3137 #endif 3138 return (SIGSTATUS_IGNORE); 3139 } 3140 3141 /* 3142 * If there is a pending stop signal to process with 3143 * default action, stop here, then clear the signal. 3144 * Traced or exiting processes should ignore stops. 3145 * Additionally, a member of an orphaned process group 3146 * should ignore tty stops. 3147 */ 3148 prop = sigprop(sig); 3149 if (prop & SIGPROP_STOP) { 3150 mtx_unlock(&ps->ps_mtx); 3151 if ((p->p_flag & (P_TRACED | P_WEXIT | 3152 P_SINGLE_EXIT)) != 0 || ((p->p_pgrp-> 3153 pg_flags & PGRP_ORPHANED) != 0 && 3154 (prop & SIGPROP_TTYSTOP) != 0)) { 3155 mtx_lock(&ps->ps_mtx); 3156 return (SIGSTATUS_IGNORE); 3157 } 3158 if (TD_SBDRY_INTR(td)) { 3159 KASSERT((td->td_flags & TDF_SBDRY) != 0, 3160 ("lost TDF_SBDRY")); 3161 mtx_lock(&ps->ps_mtx); 3162 return (SIGSTATUS_SBDRY_STOP); 3163 } 3164 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 3165 &p->p_mtx.lock_object, "Catching SIGSTOP"); 3166 sigqueue_delete(&td->td_sigqueue, sig); 3167 sigqueue_delete(&p->p_sigqueue, sig); 3168 p->p_flag |= P_STOPPED_SIG; 3169 p->p_xsig = sig; 3170 PROC_SLOCK(p); 3171 sig_suspend_threads(td, p, 0); 3172 thread_suspend_switch(td, p); 3173 PROC_SUNLOCK(p); 3174 mtx_lock(&ps->ps_mtx); 3175 return (SIGSTATUS_HANDLED); 3176 } else if ((prop & SIGPROP_IGNORE) != 0 && 3177 (td->td_flags & TDF_SIGWAIT) == 0) { 3178 /* 3179 * Default action is to ignore; drop it if 3180 * not in kern_sigtimedwait(). 3181 */ 3182 return (SIGSTATUS_IGNORE); 3183 } else { 3184 return (SIGSTATUS_HANDLE); 3185 } 3186 3187 case (intptr_t)SIG_IGN: 3188 if ((td->td_flags & TDF_SIGWAIT) == 0) 3189 return (SIGSTATUS_IGNORE); 3190 else 3191 return (SIGSTATUS_HANDLE); 3192 3193 default: 3194 /* 3195 * This signal has an action, let postsig() process it. 3196 */ 3197 return (SIGSTATUS_HANDLE); 3198 } 3199 } 3200 3201 /* 3202 * If the current process has received a signal (should be caught or cause 3203 * termination, should interrupt current syscall), return the signal number. 3204 * Stop signals with default action are processed immediately, then cleared; 3205 * they aren't returned. This is checked after each entry to the system for 3206 * a syscall or trap (though this can usually be done without calling 3207 * issignal by checking the pending signal masks in cursig.) The normal call 3208 * sequence is 3209 * 3210 * while (sig = cursig(curthread)) 3211 * postsig(sig); 3212 */ 3213 static int 3214 issignal(struct thread *td) 3215 { 3216 struct proc *p; 3217 sigset_t sigpending; 3218 int sig; 3219 3220 p = td->td_proc; 3221 PROC_LOCK_ASSERT(p, MA_OWNED); 3222 3223 for (;;) { 3224 sigpending = td->td_sigqueue.sq_signals; 3225 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 3226 SIGSETNAND(sigpending, td->td_sigmask); 3227 3228 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 3229 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 3230 SIG_STOPSIGMASK(sigpending); 3231 if (SIGISEMPTY(sigpending)) /* no signal to send */ 3232 return (0); 3233 3234 /* 3235 * Do fast sigblock if requested by usermode. Since 3236 * we do know that there was a signal pending at this 3237 * point, set the FAST_SIGBLOCK_PEND as indicator for 3238 * usermode to perform a dummy call to 3239 * FAST_SIGBLOCK_UNBLOCK, which causes immediate 3240 * delivery of postponed pending signal. 3241 */ 3242 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 3243 if (td->td_sigblock_val != 0) 3244 SIGSETNAND(sigpending, fastblock_mask); 3245 if (SIGISEMPTY(sigpending)) { 3246 td->td_pflags |= TDP_SIGFASTPENDING; 3247 return (0); 3248 } 3249 } 3250 3251 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 3252 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 3253 SIGISMEMBER(sigpending, SIGSTOP)) { 3254 /* 3255 * If debugger just attached, always consume 3256 * SIGSTOP from ptrace(PT_ATTACH) first, to 3257 * execute the debugger attach ritual in 3258 * order. 3259 */ 3260 td->td_dbgflags |= TDB_FSTP; 3261 SIGEMPTYSET(sigpending); 3262 SIGADDSET(sigpending, SIGSTOP); 3263 } 3264 3265 SIG_FOREACH(sig, &sigpending) { 3266 switch (sigprocess(td, sig)) { 3267 case SIGSTATUS_HANDLE: 3268 return (sig); 3269 case SIGSTATUS_HANDLED: 3270 goto next; 3271 case SIGSTATUS_IGNORE: 3272 sigqueue_delete(&td->td_sigqueue, sig); 3273 sigqueue_delete(&p->p_sigqueue, sig); 3274 break; 3275 case SIGSTATUS_SBDRY_STOP: 3276 return (-1); 3277 } 3278 } 3279 next:; 3280 } 3281 } 3282 3283 void 3284 thread_stopped(struct proc *p) 3285 { 3286 int n; 3287 3288 PROC_LOCK_ASSERT(p, MA_OWNED); 3289 PROC_SLOCK_ASSERT(p, MA_OWNED); 3290 n = p->p_suspcount; 3291 if (p == curproc) 3292 n++; 3293 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 3294 PROC_SUNLOCK(p); 3295 p->p_flag &= ~P_WAITED; 3296 PROC_LOCK(p->p_pptr); 3297 childproc_stopped(p, (p->p_flag & P_TRACED) ? 3298 CLD_TRAPPED : CLD_STOPPED); 3299 PROC_UNLOCK(p->p_pptr); 3300 PROC_SLOCK(p); 3301 } 3302 } 3303 3304 /* 3305 * Take the action for the specified signal 3306 * from the current set of pending signals. 3307 */ 3308 int 3309 postsig(int sig) 3310 { 3311 struct thread *td; 3312 struct proc *p; 3313 struct sigacts *ps; 3314 sig_t action; 3315 ksiginfo_t ksi; 3316 sigset_t returnmask; 3317 3318 KASSERT(sig != 0, ("postsig")); 3319 3320 td = curthread; 3321 p = td->td_proc; 3322 PROC_LOCK_ASSERT(p, MA_OWNED); 3323 ps = p->p_sigacts; 3324 mtx_assert(&ps->ps_mtx, MA_OWNED); 3325 ksiginfo_init(&ksi); 3326 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3327 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3328 return (0); 3329 ksi.ksi_signo = sig; 3330 if (ksi.ksi_code == SI_TIMER) 3331 itimer_accept(p, ksi.ksi_timerid, &ksi); 3332 action = ps->ps_sigact[_SIG_IDX(sig)]; 3333 #ifdef KTRACE 3334 if (KTRPOINT(td, KTR_PSIG)) 3335 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3336 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3337 #endif 3338 3339 if (action == SIG_DFL) { 3340 /* 3341 * Default action, where the default is to kill 3342 * the process. (Other cases were ignored above.) 3343 */ 3344 mtx_unlock(&ps->ps_mtx); 3345 proc_td_siginfo_capture(td, &ksi.ksi_info); 3346 sigexit(td, sig); 3347 /* NOTREACHED */ 3348 } else { 3349 /* 3350 * If we get here, the signal must be caught. 3351 */ 3352 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3353 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3354 ("postsig action: blocked sig %d", sig)); 3355 3356 /* 3357 * Set the new mask value and also defer further 3358 * occurrences of this signal. 3359 * 3360 * Special case: user has done a sigsuspend. Here the 3361 * current mask is not of interest, but rather the 3362 * mask from before the sigsuspend is what we want 3363 * restored after the signal processing is completed. 3364 */ 3365 if (td->td_pflags & TDP_OLDMASK) { 3366 returnmask = td->td_oldsigmask; 3367 td->td_pflags &= ~TDP_OLDMASK; 3368 } else 3369 returnmask = td->td_sigmask; 3370 3371 if (p->p_sig == sig) { 3372 p->p_sig = 0; 3373 } 3374 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3375 postsig_done(sig, td, ps); 3376 } 3377 return (1); 3378 } 3379 3380 int 3381 sig_ast_checksusp(struct thread *td) 3382 { 3383 struct proc *p __diagused; 3384 int ret; 3385 3386 p = td->td_proc; 3387 PROC_LOCK_ASSERT(p, MA_OWNED); 3388 3389 if ((td->td_flags & TDF_NEEDSUSPCHK) == 0) 3390 return (0); 3391 3392 ret = thread_suspend_check(1); 3393 MPASS(ret == 0 || ret == EINTR || ret == ERESTART); 3394 return (ret); 3395 } 3396 3397 int 3398 sig_ast_needsigchk(struct thread *td) 3399 { 3400 struct proc *p; 3401 struct sigacts *ps; 3402 int ret, sig; 3403 3404 p = td->td_proc; 3405 PROC_LOCK_ASSERT(p, MA_OWNED); 3406 3407 if ((td->td_flags & TDF_NEEDSIGCHK) == 0) 3408 return (0); 3409 3410 ps = p->p_sigacts; 3411 mtx_lock(&ps->ps_mtx); 3412 sig = cursig(td); 3413 if (sig == -1) { 3414 mtx_unlock(&ps->ps_mtx); 3415 KASSERT((td->td_flags & TDF_SBDRY) != 0, ("lost TDF_SBDRY")); 3416 KASSERT(TD_SBDRY_INTR(td), 3417 ("lost TDF_SERESTART of TDF_SEINTR")); 3418 KASSERT((td->td_flags & (TDF_SEINTR | TDF_SERESTART)) != 3419 (TDF_SEINTR | TDF_SERESTART), 3420 ("both TDF_SEINTR and TDF_SERESTART")); 3421 ret = TD_SBDRY_ERRNO(td); 3422 } else if (sig != 0) { 3423 ret = SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : ERESTART; 3424 mtx_unlock(&ps->ps_mtx); 3425 } else { 3426 mtx_unlock(&ps->ps_mtx); 3427 ret = 0; 3428 } 3429 3430 /* 3431 * Do not go into sleep if this thread was the ptrace(2) 3432 * attach leader. cursig() consumed SIGSTOP from PT_ATTACH, 3433 * but we usually act on the signal by interrupting sleep, and 3434 * should do that here as well. 3435 */ 3436 if ((td->td_dbgflags & TDB_FSTP) != 0) { 3437 if (ret == 0) 3438 ret = EINTR; 3439 td->td_dbgflags &= ~TDB_FSTP; 3440 } 3441 3442 return (ret); 3443 } 3444 3445 int 3446 sig_intr(void) 3447 { 3448 struct thread *td; 3449 struct proc *p; 3450 int ret; 3451 3452 td = curthread; 3453 if ((td->td_flags & (TDF_NEEDSIGCHK | TDF_NEEDSUSPCHK)) == 0) 3454 return (0); 3455 3456 p = td->td_proc; 3457 3458 PROC_LOCK(p); 3459 ret = sig_ast_checksusp(td); 3460 if (ret == 0) 3461 ret = sig_ast_needsigchk(td); 3462 PROC_UNLOCK(p); 3463 return (ret); 3464 } 3465 3466 bool 3467 curproc_sigkilled(void) 3468 { 3469 struct thread *td; 3470 struct proc *p; 3471 struct sigacts *ps; 3472 bool res; 3473 3474 td = curthread; 3475 if ((td->td_flags & TDF_NEEDSIGCHK) == 0) 3476 return (false); 3477 3478 p = td->td_proc; 3479 PROC_LOCK(p); 3480 ps = p->p_sigacts; 3481 mtx_lock(&ps->ps_mtx); 3482 res = SIGISMEMBER(td->td_sigqueue.sq_signals, SIGKILL) || 3483 SIGISMEMBER(p->p_sigqueue.sq_signals, SIGKILL); 3484 mtx_unlock(&ps->ps_mtx); 3485 PROC_UNLOCK(p); 3486 return (res); 3487 } 3488 3489 void 3490 proc_wkilled(struct proc *p) 3491 { 3492 3493 PROC_LOCK_ASSERT(p, MA_OWNED); 3494 if ((p->p_flag & P_WKILLED) == 0) { 3495 p->p_flag |= P_WKILLED; 3496 /* 3497 * Notify swapper that there is a process to swap in. 3498 * The notification is racy, at worst it would take 10 3499 * seconds for the swapper process to notice. 3500 */ 3501 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3502 wakeup(&proc0); 3503 } 3504 } 3505 3506 /* 3507 * Kill the current process for stated reason. 3508 */ 3509 void 3510 killproc(struct proc *p, const char *why) 3511 { 3512 3513 PROC_LOCK_ASSERT(p, MA_OWNED); 3514 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3515 p->p_comm); 3516 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3517 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3518 p->p_ucred->cr_uid, why); 3519 proc_wkilled(p); 3520 kern_psignal(p, SIGKILL); 3521 } 3522 3523 /* 3524 * Force the current process to exit with the specified signal, dumping core 3525 * if appropriate. We bypass the normal tests for masked and caught signals, 3526 * allowing unrecoverable failures to terminate the process without changing 3527 * signal state. Mark the accounting record with the signal termination. 3528 * If dumping core, save the signal number for the debugger. Calls exit and 3529 * does not return. 3530 */ 3531 void 3532 sigexit(struct thread *td, int sig) 3533 { 3534 struct proc *p = td->td_proc; 3535 3536 PROC_LOCK_ASSERT(p, MA_OWNED); 3537 proc_set_p2_wexit(p); 3538 3539 p->p_acflag |= AXSIG; 3540 /* 3541 * We must be single-threading to generate a core dump. This 3542 * ensures that the registers in the core file are up-to-date. 3543 * Also, the ELF dump handler assumes that the thread list doesn't 3544 * change out from under it. 3545 * 3546 * XXX If another thread attempts to single-thread before us 3547 * (e.g. via fork()), we won't get a dump at all. 3548 */ 3549 if ((sigprop(sig) & SIGPROP_CORE) && 3550 thread_single(p, SINGLE_NO_EXIT) == 0) { 3551 p->p_sig = sig; 3552 /* 3553 * Log signals which would cause core dumps 3554 * (Log as LOG_INFO to appease those who don't want 3555 * these messages.) 3556 * XXX : Todo, as well as euid, write out ruid too 3557 * Note that coredump() drops proc lock. 3558 */ 3559 if (coredump(td) == 0) 3560 sig |= WCOREFLAG; 3561 if (kern_logsigexit) 3562 log(LOG_INFO, 3563 "pid %d (%s), jid %d, uid %d: exited on " 3564 "signal %d%s\n", p->p_pid, p->p_comm, 3565 p->p_ucred->cr_prison->pr_id, 3566 td->td_ucred->cr_uid, 3567 sig &~ WCOREFLAG, 3568 sig & WCOREFLAG ? " (core dumped)" : ""); 3569 } else 3570 PROC_UNLOCK(p); 3571 exit1(td, 0, sig); 3572 /* NOTREACHED */ 3573 } 3574 3575 /* 3576 * Send queued SIGCHLD to parent when child process's state 3577 * is changed. 3578 */ 3579 static void 3580 sigparent(struct proc *p, int reason, int status) 3581 { 3582 PROC_LOCK_ASSERT(p, MA_OWNED); 3583 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3584 3585 if (p->p_ksi != NULL) { 3586 p->p_ksi->ksi_signo = SIGCHLD; 3587 p->p_ksi->ksi_code = reason; 3588 p->p_ksi->ksi_status = status; 3589 p->p_ksi->ksi_pid = p->p_pid; 3590 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3591 if (KSI_ONQ(p->p_ksi)) 3592 return; 3593 } 3594 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3595 } 3596 3597 static void 3598 childproc_jobstate(struct proc *p, int reason, int sig) 3599 { 3600 struct sigacts *ps; 3601 3602 PROC_LOCK_ASSERT(p, MA_OWNED); 3603 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3604 3605 /* 3606 * Wake up parent sleeping in kern_wait(), also send 3607 * SIGCHLD to parent, but SIGCHLD does not guarantee 3608 * that parent will awake, because parent may masked 3609 * the signal. 3610 */ 3611 p->p_pptr->p_flag |= P_STATCHILD; 3612 wakeup(p->p_pptr); 3613 3614 ps = p->p_pptr->p_sigacts; 3615 mtx_lock(&ps->ps_mtx); 3616 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3617 mtx_unlock(&ps->ps_mtx); 3618 sigparent(p, reason, sig); 3619 } else 3620 mtx_unlock(&ps->ps_mtx); 3621 } 3622 3623 void 3624 childproc_stopped(struct proc *p, int reason) 3625 { 3626 3627 childproc_jobstate(p, reason, p->p_xsig); 3628 } 3629 3630 void 3631 childproc_continued(struct proc *p) 3632 { 3633 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3634 } 3635 3636 void 3637 childproc_exited(struct proc *p) 3638 { 3639 int reason, status; 3640 3641 if (WCOREDUMP(p->p_xsig)) { 3642 reason = CLD_DUMPED; 3643 status = WTERMSIG(p->p_xsig); 3644 } else if (WIFSIGNALED(p->p_xsig)) { 3645 reason = CLD_KILLED; 3646 status = WTERMSIG(p->p_xsig); 3647 } else { 3648 reason = CLD_EXITED; 3649 status = p->p_xexit; 3650 } 3651 /* 3652 * XXX avoid calling wakeup(p->p_pptr), the work is 3653 * done in exit1(). 3654 */ 3655 sigparent(p, reason, status); 3656 } 3657 3658 #define MAX_NUM_CORE_FILES 100000 3659 #ifndef NUM_CORE_FILES 3660 #define NUM_CORE_FILES 5 3661 #endif 3662 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3663 static int num_cores = NUM_CORE_FILES; 3664 3665 static int 3666 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3667 { 3668 int error; 3669 int new_val; 3670 3671 new_val = num_cores; 3672 error = sysctl_handle_int(oidp, &new_val, 0, req); 3673 if (error != 0 || req->newptr == NULL) 3674 return (error); 3675 if (new_val > MAX_NUM_CORE_FILES) 3676 new_val = MAX_NUM_CORE_FILES; 3677 if (new_val < 0) 3678 new_val = 0; 3679 num_cores = new_val; 3680 return (0); 3681 } 3682 SYSCTL_PROC(_debug, OID_AUTO, ncores, 3683 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, sizeof(int), 3684 sysctl_debug_num_cores_check, "I", 3685 "Maximum number of generated process corefiles while using index format"); 3686 3687 #define GZIP_SUFFIX ".gz" 3688 #define ZSTD_SUFFIX ".zst" 3689 3690 int compress_user_cores = 0; 3691 3692 static int 3693 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3694 { 3695 int error, val; 3696 3697 val = compress_user_cores; 3698 error = sysctl_handle_int(oidp, &val, 0, req); 3699 if (error != 0 || req->newptr == NULL) 3700 return (error); 3701 if (val != 0 && !compressor_avail(val)) 3702 return (EINVAL); 3703 compress_user_cores = val; 3704 return (error); 3705 } 3706 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, 3707 CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3708 sysctl_compress_user_cores, "I", 3709 "Enable compression of user corefiles (" 3710 __XSTRING(COMPRESS_GZIP) " = gzip, " 3711 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3712 3713 int compress_user_cores_level = 6; 3714 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3715 &compress_user_cores_level, 0, 3716 "Corefile compression level"); 3717 3718 /* 3719 * Protect the access to corefilename[] by allproc_lock. 3720 */ 3721 #define corefilename_lock allproc_lock 3722 3723 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3724 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3725 3726 static int 3727 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3728 { 3729 int error; 3730 3731 sx_xlock(&corefilename_lock); 3732 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3733 req); 3734 sx_xunlock(&corefilename_lock); 3735 3736 return (error); 3737 } 3738 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3739 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3740 "Process corefile name format string"); 3741 3742 static void 3743 vnode_close_locked(struct thread *td, struct vnode *vp) 3744 { 3745 3746 VOP_UNLOCK(vp); 3747 vn_close(vp, FWRITE, td->td_ucred, td); 3748 } 3749 3750 /* 3751 * If the core format has a %I in it, then we need to check 3752 * for existing corefiles before defining a name. 3753 * To do this we iterate over 0..ncores to find a 3754 * non-existing core file name to use. If all core files are 3755 * already used we choose the oldest one. 3756 */ 3757 static int 3758 corefile_open_last(struct thread *td, char *name, int indexpos, 3759 int indexlen, int ncores, struct vnode **vpp) 3760 { 3761 struct vnode *oldvp, *nextvp, *vp; 3762 struct vattr vattr; 3763 struct nameidata nd; 3764 int error, i, flags, oflags, cmode; 3765 char ch; 3766 struct timespec lasttime; 3767 3768 nextvp = oldvp = NULL; 3769 cmode = S_IRUSR | S_IWUSR; 3770 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3771 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3772 3773 for (i = 0; i < ncores; i++) { 3774 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3775 3776 ch = name[indexpos + indexlen]; 3777 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3778 i); 3779 name[indexpos + indexlen] = ch; 3780 3781 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3782 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3783 NULL); 3784 if (error != 0) 3785 break; 3786 3787 vp = nd.ni_vp; 3788 NDFREE(&nd, NDF_ONLY_PNBUF); 3789 if ((flags & O_CREAT) == O_CREAT) { 3790 nextvp = vp; 3791 break; 3792 } 3793 3794 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3795 if (error != 0) { 3796 vnode_close_locked(td, vp); 3797 break; 3798 } 3799 3800 if (oldvp == NULL || 3801 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3802 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3803 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3804 if (oldvp != NULL) 3805 vn_close(oldvp, FWRITE, td->td_ucred, td); 3806 oldvp = vp; 3807 VOP_UNLOCK(oldvp); 3808 lasttime = vattr.va_mtime; 3809 } else { 3810 vnode_close_locked(td, vp); 3811 } 3812 } 3813 3814 if (oldvp != NULL) { 3815 if (nextvp == NULL) { 3816 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3817 error = EFAULT; 3818 vn_close(oldvp, FWRITE, td->td_ucred, td); 3819 } else { 3820 nextvp = oldvp; 3821 error = vn_lock(nextvp, LK_EXCLUSIVE); 3822 if (error != 0) { 3823 vn_close(nextvp, FWRITE, td->td_ucred, 3824 td); 3825 nextvp = NULL; 3826 } 3827 } 3828 } else { 3829 vn_close(oldvp, FWRITE, td->td_ucred, td); 3830 } 3831 } 3832 if (error != 0) { 3833 if (nextvp != NULL) 3834 vnode_close_locked(td, oldvp); 3835 } else { 3836 *vpp = nextvp; 3837 } 3838 3839 return (error); 3840 } 3841 3842 /* 3843 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3844 * Expand the name described in corefilename, using name, uid, and pid 3845 * and open/create core file. 3846 * corefilename is a printf-like string, with three format specifiers: 3847 * %N name of process ("name") 3848 * %P process id (pid) 3849 * %U user id (uid) 3850 * For example, "%N.core" is the default; they can be disabled completely 3851 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3852 * This is controlled by the sysctl variable kern.corefile (see above). 3853 */ 3854 static int 3855 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3856 int compress, int signum, struct vnode **vpp, char **namep) 3857 { 3858 struct sbuf sb; 3859 struct nameidata nd; 3860 const char *format; 3861 char *hostname, *name; 3862 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3863 3864 hostname = NULL; 3865 format = corefilename; 3866 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3867 indexlen = 0; 3868 indexpos = -1; 3869 ncores = num_cores; 3870 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3871 sx_slock(&corefilename_lock); 3872 for (i = 0; format[i] != '\0'; i++) { 3873 switch (format[i]) { 3874 case '%': /* Format character */ 3875 i++; 3876 switch (format[i]) { 3877 case '%': 3878 sbuf_putc(&sb, '%'); 3879 break; 3880 case 'H': /* hostname */ 3881 if (hostname == NULL) { 3882 hostname = malloc(MAXHOSTNAMELEN, 3883 M_TEMP, M_WAITOK); 3884 } 3885 getcredhostname(td->td_ucred, hostname, 3886 MAXHOSTNAMELEN); 3887 sbuf_printf(&sb, "%s", hostname); 3888 break; 3889 case 'I': /* autoincrementing index */ 3890 if (indexpos != -1) { 3891 sbuf_printf(&sb, "%%I"); 3892 break; 3893 } 3894 3895 indexpos = sbuf_len(&sb); 3896 sbuf_printf(&sb, "%u", ncores - 1); 3897 indexlen = sbuf_len(&sb) - indexpos; 3898 break; 3899 case 'N': /* process name */ 3900 sbuf_printf(&sb, "%s", comm); 3901 break; 3902 case 'P': /* process id */ 3903 sbuf_printf(&sb, "%u", pid); 3904 break; 3905 case 'S': /* signal number */ 3906 sbuf_printf(&sb, "%i", signum); 3907 break; 3908 case 'U': /* user id */ 3909 sbuf_printf(&sb, "%u", uid); 3910 break; 3911 default: 3912 log(LOG_ERR, 3913 "Unknown format character %c in " 3914 "corename `%s'\n", format[i], format); 3915 break; 3916 } 3917 break; 3918 default: 3919 sbuf_putc(&sb, format[i]); 3920 break; 3921 } 3922 } 3923 sx_sunlock(&corefilename_lock); 3924 free(hostname, M_TEMP); 3925 if (compress == COMPRESS_GZIP) 3926 sbuf_printf(&sb, GZIP_SUFFIX); 3927 else if (compress == COMPRESS_ZSTD) 3928 sbuf_printf(&sb, ZSTD_SUFFIX); 3929 if (sbuf_error(&sb) != 0) { 3930 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3931 "long\n", (long)pid, comm, (u_long)uid); 3932 sbuf_delete(&sb); 3933 free(name, M_TEMP); 3934 return (ENOMEM); 3935 } 3936 sbuf_finish(&sb); 3937 sbuf_delete(&sb); 3938 3939 if (indexpos != -1) { 3940 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3941 vpp); 3942 if (error != 0) { 3943 log(LOG_ERR, 3944 "pid %d (%s), uid (%u): Path `%s' failed " 3945 "on initial open test, error = %d\n", 3946 pid, comm, uid, name, error); 3947 } 3948 } else { 3949 cmode = S_IRUSR | S_IWUSR; 3950 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3951 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3952 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3953 if ((td->td_proc->p_flag & P_SUGID) != 0) 3954 flags |= O_EXCL; 3955 3956 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3957 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3958 NULL); 3959 if (error == 0) { 3960 *vpp = nd.ni_vp; 3961 NDFREE(&nd, NDF_ONLY_PNBUF); 3962 } 3963 } 3964 3965 if (error != 0) { 3966 #ifdef AUDIT 3967 audit_proc_coredump(td, name, error); 3968 #endif 3969 free(name, M_TEMP); 3970 return (error); 3971 } 3972 *namep = name; 3973 return (0); 3974 } 3975 3976 /* 3977 * Dump a process' core. The main routine does some 3978 * policy checking, and creates the name of the coredump; 3979 * then it passes on a vnode and a size limit to the process-specific 3980 * coredump routine if there is one; if there _is not_ one, it returns 3981 * ENOSYS; otherwise it returns the error from the process-specific routine. 3982 */ 3983 3984 static int 3985 coredump(struct thread *td) 3986 { 3987 struct proc *p = td->td_proc; 3988 struct ucred *cred = td->td_ucred; 3989 struct vnode *vp; 3990 struct flock lf; 3991 struct vattr vattr; 3992 size_t fullpathsize; 3993 int error, error1, locked; 3994 char *name; /* name of corefile */ 3995 void *rl_cookie; 3996 off_t limit; 3997 char *fullpath, *freepath = NULL; 3998 struct sbuf *sb; 3999 4000 PROC_LOCK_ASSERT(p, MA_OWNED); 4001 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 4002 4003 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 4004 (p->p_flag2 & P2_NOTRACE) != 0) { 4005 PROC_UNLOCK(p); 4006 return (EFAULT); 4007 } 4008 4009 /* 4010 * Note that the bulk of limit checking is done after 4011 * the corefile is created. The exception is if the limit 4012 * for corefiles is 0, in which case we don't bother 4013 * creating the corefile at all. This layout means that 4014 * a corefile is truncated instead of not being created, 4015 * if it is larger than the limit. 4016 */ 4017 limit = (off_t)lim_cur(td, RLIMIT_CORE); 4018 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 4019 PROC_UNLOCK(p); 4020 return (EFBIG); 4021 } 4022 PROC_UNLOCK(p); 4023 4024 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 4025 compress_user_cores, p->p_sig, &vp, &name); 4026 if (error != 0) 4027 return (error); 4028 4029 /* 4030 * Don't dump to non-regular files or files with links. 4031 * Do not dump into system files. Effective user must own the corefile. 4032 */ 4033 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 4034 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 4035 vattr.va_uid != cred->cr_uid) { 4036 VOP_UNLOCK(vp); 4037 error = EFAULT; 4038 goto out; 4039 } 4040 4041 VOP_UNLOCK(vp); 4042 4043 /* Postpone other writers, including core dumps of other processes. */ 4044 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 4045 4046 lf.l_whence = SEEK_SET; 4047 lf.l_start = 0; 4048 lf.l_len = 0; 4049 lf.l_type = F_WRLCK; 4050 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 4051 4052 VATTR_NULL(&vattr); 4053 vattr.va_size = 0; 4054 if (set_core_nodump_flag) 4055 vattr.va_flags = UF_NODUMP; 4056 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4057 VOP_SETATTR(vp, &vattr, cred); 4058 VOP_UNLOCK(vp); 4059 PROC_LOCK(p); 4060 p->p_acflag |= ACORE; 4061 PROC_UNLOCK(p); 4062 4063 if (p->p_sysent->sv_coredump != NULL) { 4064 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 4065 } else { 4066 error = ENOSYS; 4067 } 4068 4069 if (locked) { 4070 lf.l_type = F_UNLCK; 4071 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 4072 } 4073 vn_rangelock_unlock(vp, rl_cookie); 4074 4075 /* 4076 * Notify the userland helper that a process triggered a core dump. 4077 * This allows the helper to run an automated debugging session. 4078 */ 4079 if (error != 0 || coredump_devctl == 0) 4080 goto out; 4081 sb = sbuf_new_auto(); 4082 if (vn_fullpath_global(p->p_textvp, &fullpath, &freepath) != 0) 4083 goto out2; 4084 sbuf_printf(sb, "comm=\""); 4085 devctl_safe_quote_sb(sb, fullpath); 4086 free(freepath, M_TEMP); 4087 sbuf_printf(sb, "\" core=\""); 4088 4089 /* 4090 * We can't lookup core file vp directly. When we're replacing a core, and 4091 * other random times, we flush the name cache, so it will fail. Instead, 4092 * if the path of the core is relative, add the current dir in front if it. 4093 */ 4094 if (name[0] != '/') { 4095 fullpathsize = MAXPATHLEN; 4096 freepath = malloc(fullpathsize, M_TEMP, M_WAITOK); 4097 if (vn_getcwd(freepath, &fullpath, &fullpathsize) != 0) { 4098 free(freepath, M_TEMP); 4099 goto out2; 4100 } 4101 devctl_safe_quote_sb(sb, fullpath); 4102 free(freepath, M_TEMP); 4103 sbuf_putc(sb, '/'); 4104 } 4105 devctl_safe_quote_sb(sb, name); 4106 sbuf_printf(sb, "\""); 4107 if (sbuf_finish(sb) == 0) 4108 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 4109 out2: 4110 sbuf_delete(sb); 4111 out: 4112 error1 = vn_close(vp, FWRITE, cred, td); 4113 if (error == 0) 4114 error = error1; 4115 #ifdef AUDIT 4116 audit_proc_coredump(td, name, error); 4117 #endif 4118 free(name, M_TEMP); 4119 return (error); 4120 } 4121 4122 /* 4123 * Nonexistent system call-- signal process (may want to handle it). Flag 4124 * error in case process won't see signal immediately (blocked or ignored). 4125 */ 4126 #ifndef _SYS_SYSPROTO_H_ 4127 struct nosys_args { 4128 int dummy; 4129 }; 4130 #endif 4131 /* ARGSUSED */ 4132 int 4133 nosys(struct thread *td, struct nosys_args *args) 4134 { 4135 struct proc *p; 4136 4137 p = td->td_proc; 4138 4139 PROC_LOCK(p); 4140 tdsignal(td, SIGSYS); 4141 PROC_UNLOCK(p); 4142 if (kern_lognosys == 1 || kern_lognosys == 3) { 4143 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 4144 td->td_sa.code); 4145 } 4146 if (kern_lognosys == 2 || kern_lognosys == 3 || 4147 (p->p_pid == 1 && (kern_lognosys & 3) == 0)) { 4148 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 4149 td->td_sa.code); 4150 } 4151 return (ENOSYS); 4152 } 4153 4154 /* 4155 * Send a SIGIO or SIGURG signal to a process or process group using stored 4156 * credentials rather than those of the current process. 4157 */ 4158 void 4159 pgsigio(struct sigio **sigiop, int sig, int checkctty) 4160 { 4161 ksiginfo_t ksi; 4162 struct sigio *sigio; 4163 4164 ksiginfo_init(&ksi); 4165 ksi.ksi_signo = sig; 4166 ksi.ksi_code = SI_KERNEL; 4167 4168 SIGIO_LOCK(); 4169 sigio = *sigiop; 4170 if (sigio == NULL) { 4171 SIGIO_UNLOCK(); 4172 return; 4173 } 4174 if (sigio->sio_pgid > 0) { 4175 PROC_LOCK(sigio->sio_proc); 4176 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 4177 kern_psignal(sigio->sio_proc, sig); 4178 PROC_UNLOCK(sigio->sio_proc); 4179 } else if (sigio->sio_pgid < 0) { 4180 struct proc *p; 4181 4182 PGRP_LOCK(sigio->sio_pgrp); 4183 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 4184 PROC_LOCK(p); 4185 if (p->p_state == PRS_NORMAL && 4186 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 4187 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 4188 kern_psignal(p, sig); 4189 PROC_UNLOCK(p); 4190 } 4191 PGRP_UNLOCK(sigio->sio_pgrp); 4192 } 4193 SIGIO_UNLOCK(); 4194 } 4195 4196 static int 4197 filt_sigattach(struct knote *kn) 4198 { 4199 struct proc *p = curproc; 4200 4201 kn->kn_ptr.p_proc = p; 4202 kn->kn_flags |= EV_CLEAR; /* automatically set */ 4203 4204 knlist_add(p->p_klist, kn, 0); 4205 4206 return (0); 4207 } 4208 4209 static void 4210 filt_sigdetach(struct knote *kn) 4211 { 4212 struct proc *p = kn->kn_ptr.p_proc; 4213 4214 knlist_remove(p->p_klist, kn, 0); 4215 } 4216 4217 /* 4218 * signal knotes are shared with proc knotes, so we apply a mask to 4219 * the hint in order to differentiate them from process hints. This 4220 * could be avoided by using a signal-specific knote list, but probably 4221 * isn't worth the trouble. 4222 */ 4223 static int 4224 filt_signal(struct knote *kn, long hint) 4225 { 4226 4227 if (hint & NOTE_SIGNAL) { 4228 hint &= ~NOTE_SIGNAL; 4229 4230 if (kn->kn_id == hint) 4231 kn->kn_data++; 4232 } 4233 return (kn->kn_data != 0); 4234 } 4235 4236 struct sigacts * 4237 sigacts_alloc(void) 4238 { 4239 struct sigacts *ps; 4240 4241 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 4242 refcount_init(&ps->ps_refcnt, 1); 4243 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 4244 return (ps); 4245 } 4246 4247 void 4248 sigacts_free(struct sigacts *ps) 4249 { 4250 4251 if (refcount_release(&ps->ps_refcnt) == 0) 4252 return; 4253 mtx_destroy(&ps->ps_mtx); 4254 free(ps, M_SUBPROC); 4255 } 4256 4257 struct sigacts * 4258 sigacts_hold(struct sigacts *ps) 4259 { 4260 4261 refcount_acquire(&ps->ps_refcnt); 4262 return (ps); 4263 } 4264 4265 void 4266 sigacts_copy(struct sigacts *dest, struct sigacts *src) 4267 { 4268 4269 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 4270 mtx_lock(&src->ps_mtx); 4271 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 4272 mtx_unlock(&src->ps_mtx); 4273 } 4274 4275 int 4276 sigacts_shared(struct sigacts *ps) 4277 { 4278 4279 return (ps->ps_refcnt > 1); 4280 } 4281 4282 void 4283 sig_drop_caught(struct proc *p) 4284 { 4285 int sig; 4286 struct sigacts *ps; 4287 4288 ps = p->p_sigacts; 4289 PROC_LOCK_ASSERT(p, MA_OWNED); 4290 mtx_assert(&ps->ps_mtx, MA_OWNED); 4291 SIG_FOREACH(sig, &ps->ps_sigcatch) { 4292 sigdflt(ps, sig); 4293 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 4294 sigqueue_delete_proc(p, sig); 4295 } 4296 } 4297 4298 static void 4299 sigfastblock_failed(struct thread *td, bool sendsig, bool write) 4300 { 4301 ksiginfo_t ksi; 4302 4303 /* 4304 * Prevent further fetches and SIGSEGVs, allowing thread to 4305 * issue syscalls despite corruption. 4306 */ 4307 sigfastblock_clear(td); 4308 4309 if (!sendsig) 4310 return; 4311 ksiginfo_init_trap(&ksi); 4312 ksi.ksi_signo = SIGSEGV; 4313 ksi.ksi_code = write ? SEGV_ACCERR : SEGV_MAPERR; 4314 ksi.ksi_addr = td->td_sigblock_ptr; 4315 trapsignal(td, &ksi); 4316 } 4317 4318 static bool 4319 sigfastblock_fetch_sig(struct thread *td, bool sendsig, uint32_t *valp) 4320 { 4321 uint32_t res; 4322 4323 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4324 return (true); 4325 if (fueword32((void *)td->td_sigblock_ptr, &res) == -1) { 4326 sigfastblock_failed(td, sendsig, false); 4327 return (false); 4328 } 4329 *valp = res; 4330 td->td_sigblock_val = res & ~SIGFASTBLOCK_FLAGS; 4331 return (true); 4332 } 4333 4334 static void 4335 sigfastblock_resched(struct thread *td, bool resched) 4336 { 4337 struct proc *p; 4338 4339 if (resched) { 4340 p = td->td_proc; 4341 PROC_LOCK(p); 4342 reschedule_signals(p, td->td_sigmask, 0); 4343 PROC_UNLOCK(p); 4344 } 4345 thread_lock(td); 4346 td->td_flags |= TDF_ASTPENDING | TDF_NEEDSIGCHK; 4347 thread_unlock(td); 4348 } 4349 4350 int 4351 sys_sigfastblock(struct thread *td, struct sigfastblock_args *uap) 4352 { 4353 struct proc *p; 4354 int error, res; 4355 uint32_t oldval; 4356 4357 error = 0; 4358 p = td->td_proc; 4359 switch (uap->cmd) { 4360 case SIGFASTBLOCK_SETPTR: 4361 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 4362 error = EBUSY; 4363 break; 4364 } 4365 if (((uintptr_t)(uap->ptr) & (sizeof(uint32_t) - 1)) != 0) { 4366 error = EINVAL; 4367 break; 4368 } 4369 td->td_pflags |= TDP_SIGFASTBLOCK; 4370 td->td_sigblock_ptr = uap->ptr; 4371 break; 4372 4373 case SIGFASTBLOCK_UNBLOCK: 4374 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4375 error = EINVAL; 4376 break; 4377 } 4378 4379 for (;;) { 4380 res = casueword32(td->td_sigblock_ptr, 4381 SIGFASTBLOCK_PEND, &oldval, 0); 4382 if (res == -1) { 4383 error = EFAULT; 4384 sigfastblock_failed(td, false, true); 4385 break; 4386 } 4387 if (res == 0) 4388 break; 4389 MPASS(res == 1); 4390 if (oldval != SIGFASTBLOCK_PEND) { 4391 error = EBUSY; 4392 break; 4393 } 4394 error = thread_check_susp(td, false); 4395 if (error != 0) 4396 break; 4397 } 4398 if (error != 0) 4399 break; 4400 4401 /* 4402 * td_sigblock_val is cleared there, but not on a 4403 * syscall exit. The end effect is that a single 4404 * interruptible sleep, while user sigblock word is 4405 * set, might return EINTR or ERESTART to usermode 4406 * without delivering signal. All further sleeps, 4407 * until userspace clears the word and does 4408 * sigfastblock(UNBLOCK), observe current word and no 4409 * longer get interrupted. It is slight 4410 * non-conformance, with alternative to have read the 4411 * sigblock word on each syscall entry. 4412 */ 4413 td->td_sigblock_val = 0; 4414 4415 /* 4416 * Rely on normal ast mechanism to deliver pending 4417 * signals to current thread. But notify others about 4418 * fake unblock. 4419 */ 4420 sigfastblock_resched(td, error == 0 && p->p_numthreads != 1); 4421 4422 break; 4423 4424 case SIGFASTBLOCK_UNSETPTR: 4425 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4426 error = EINVAL; 4427 break; 4428 } 4429 if (!sigfastblock_fetch_sig(td, false, &oldval)) { 4430 error = EFAULT; 4431 break; 4432 } 4433 if (oldval != 0 && oldval != SIGFASTBLOCK_PEND) { 4434 error = EBUSY; 4435 break; 4436 } 4437 sigfastblock_clear(td); 4438 break; 4439 4440 default: 4441 error = EINVAL; 4442 break; 4443 } 4444 return (error); 4445 } 4446 4447 void 4448 sigfastblock_clear(struct thread *td) 4449 { 4450 bool resched; 4451 4452 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4453 return; 4454 td->td_sigblock_val = 0; 4455 resched = (td->td_pflags & TDP_SIGFASTPENDING) != 0 || 4456 SIGPENDING(td); 4457 td->td_pflags &= ~(TDP_SIGFASTBLOCK | TDP_SIGFASTPENDING); 4458 sigfastblock_resched(td, resched); 4459 } 4460 4461 void 4462 sigfastblock_fetch(struct thread *td) 4463 { 4464 uint32_t val; 4465 4466 (void)sigfastblock_fetch_sig(td, true, &val); 4467 } 4468 4469 static void 4470 sigfastblock_setpend1(struct thread *td) 4471 { 4472 int res; 4473 uint32_t oldval; 4474 4475 if ((td->td_pflags & TDP_SIGFASTPENDING) == 0) 4476 return; 4477 res = fueword32((void *)td->td_sigblock_ptr, &oldval); 4478 if (res == -1) { 4479 sigfastblock_failed(td, true, false); 4480 return; 4481 } 4482 for (;;) { 4483 res = casueword32(td->td_sigblock_ptr, oldval, &oldval, 4484 oldval | SIGFASTBLOCK_PEND); 4485 if (res == -1) { 4486 sigfastblock_failed(td, true, true); 4487 return; 4488 } 4489 if (res == 0) { 4490 td->td_sigblock_val = oldval & ~SIGFASTBLOCK_FLAGS; 4491 td->td_pflags &= ~TDP_SIGFASTPENDING; 4492 break; 4493 } 4494 MPASS(res == 1); 4495 if (thread_check_susp(td, false) != 0) 4496 break; 4497 } 4498 } 4499 4500 void 4501 sigfastblock_setpend(struct thread *td, bool resched) 4502 { 4503 struct proc *p; 4504 4505 sigfastblock_setpend1(td); 4506 if (resched) { 4507 p = td->td_proc; 4508 PROC_LOCK(p); 4509 reschedule_signals(p, fastblock_mask, SIGPROCMASK_FASTBLK); 4510 PROC_UNLOCK(p); 4511 } 4512 }
Cache object: 3352f2259d6a6eb0f2d14cf04c650a1b
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