1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org> 5 * Copyright 2004 John-Mark Gurney <jmg@FreeBSD.org> 6 * Copyright (c) 2009 Apple, Inc. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/cdefs.h> 32 #include "opt_ktrace.h" 33 #include "opt_kqueue.h" 34 35 #ifdef COMPAT_FREEBSD11 36 #define _WANT_FREEBSD11_KEVENT 37 #endif 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/capsicum.h> 42 #include <sys/kernel.h> 43 #include <sys/limits.h> 44 #include <sys/lock.h> 45 #include <sys/mutex.h> 46 #include <sys/proc.h> 47 #include <sys/malloc.h> 48 #include <sys/unistd.h> 49 #include <sys/file.h> 50 #include <sys/filedesc.h> 51 #include <sys/filio.h> 52 #include <sys/fcntl.h> 53 #include <sys/jail.h> 54 #include <sys/jaildesc.h> 55 #include <sys/kthread.h> 56 #include <sys/selinfo.h> 57 #include <sys/queue.h> 58 #include <sys/event.h> 59 #include <sys/eventvar.h> 60 #include <sys/poll.h> 61 #include <sys/protosw.h> 62 #include <sys/resourcevar.h> 63 #include <sys/sbuf.h> 64 #include <sys/sigio.h> 65 #include <sys/signalvar.h> 66 #include <sys/socket.h> 67 #include <sys/socketvar.h> 68 #include <sys/stat.h> 69 #include <sys/sysctl.h> 70 #include <sys/sysent.h> 71 #include <sys/sysproto.h> 72 #include <sys/syscallsubr.h> 73 #include <sys/taskqueue.h> 74 #include <sys/uio.h> 75 #include <sys/user.h> 76 #ifdef KTRACE 77 #include <sys/ktrace.h> 78 #endif 79 #include <machine/atomic.h> 80 #ifdef COMPAT_FREEBSD32 81 #include <compat/freebsd32/freebsd32.h> 82 #include <compat/freebsd32/freebsd32_util.h> 83 #endif 84 85 #include <vm/uma.h> 86 87 static MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system"); 88 89 /* 90 * This lock is used if multiple kq locks are required. This possibly 91 * should be made into a per proc lock. 92 */ 93 static struct mtx kq_global; 94 MTX_SYSINIT(kq_global, &kq_global, "kqueue order", MTX_DEF); 95 #define KQ_GLOBAL_LOCK(lck, haslck) do { \ 96 if (!haslck) \ 97 mtx_lock(lck); \ 98 haslck = 1; \ 99 } while (0) 100 #define KQ_GLOBAL_UNLOCK(lck, haslck) do { \ 101 if (haslck) \ 102 mtx_unlock(lck); \ 103 haslck = 0; \ 104 } while (0) 105 106 TASKQUEUE_DEFINE_THREAD(kqueue_ctx); 107 108 static int kevent_copyout(void *arg, struct kevent *kevp, int count); 109 static int kevent_copyin(void *arg, struct kevent *kevp, int count); 110 static int kqueue_register(struct kqueue *kq, struct kevent *kev, 111 struct thread *td, int mflag); 112 static int kqueue_acquire(struct file *fp, struct kqueue **kqp); 113 static void kqueue_release(struct kqueue *kq, int locked); 114 static void kqueue_destroy(struct kqueue *kq); 115 static void kqueue_drain(struct kqueue *kq, struct thread *td); 116 static int kqueue_expand(struct kqueue *kq, const struct filterops *fops, 117 uintptr_t ident, int mflag); 118 static void kqueue_task(void *arg, int pending); 119 static int kqueue_scan(struct kqueue *kq, int maxevents, 120 struct kevent_copyops *k_ops, 121 const struct timespec *timeout, 122 struct kevent *keva, struct thread *td); 123 static void kqueue_wakeup(struct kqueue *kq); 124 static const struct filterops *kqueue_fo_find(int filt); 125 static void kqueue_fo_release(int filt); 126 struct g_kevent_args; 127 static int kern_kevent_generic(struct thread *td, 128 struct g_kevent_args *uap, 129 struct kevent_copyops *k_ops, const char *struct_name); 130 131 static fo_ioctl_t kqueue_ioctl; 132 static fo_poll_t kqueue_poll; 133 static fo_kqfilter_t kqueue_kqfilter; 134 static fo_stat_t kqueue_stat; 135 static fo_close_t kqueue_close; 136 static fo_fill_kinfo_t kqueue_fill_kinfo; 137 static fo_fork_t kqueue_fork; 138 139 static const struct fileops kqueueops = { 140 .fo_read = invfo_rdwr, 141 .fo_write = invfo_rdwr, 142 .fo_truncate = invfo_truncate, 143 .fo_ioctl = kqueue_ioctl, 144 .fo_poll = kqueue_poll, 145 .fo_kqfilter = kqueue_kqfilter, 146 .fo_stat = kqueue_stat, 147 .fo_close = kqueue_close, 148 .fo_chmod = invfo_chmod, 149 .fo_chown = invfo_chown, 150 .fo_sendfile = invfo_sendfile, 151 .fo_cmp = file_kcmp_generic, 152 .fo_fork = kqueue_fork, 153 .fo_fill_kinfo = kqueue_fill_kinfo, 154 .fo_flags = DFLAG_FORK, 155 }; 156 157 static int knote_attach(struct knote *kn, struct kqueue *kq); 158 static void knote_drop(struct knote *kn, struct thread *td); 159 static void knote_drop_detached(struct knote *kn, struct thread *td); 160 static void knote_enqueue(struct knote *kn); 161 static void knote_dequeue(struct knote *kn); 162 static void knote_init(void *); 163 static struct knote *knote_alloc(int mflag); 164 static void knote_free(struct knote *kn); 165 166 static void filt_kqdetach(struct knote *kn); 167 static int filt_kqueue(struct knote *kn, long hint); 168 static int filt_procattach(struct knote *kn); 169 static void filt_procdetach(struct knote *kn); 170 static int filt_proc(struct knote *kn, long hint); 171 static int filt_jailattach(struct knote *kn); 172 static void filt_jaildetach(struct knote *kn); 173 static int filt_jail(struct knote *kn, long hint); 174 static int filt_fileattach(struct knote *kn); 175 static void filt_timerexpire(void *knx); 176 static void filt_timerexpire_l(struct knote *kn, bool proc_locked); 177 static int filt_timerattach(struct knote *kn); 178 static void filt_timerdetach(struct knote *kn); 179 static void filt_timerstart(struct knote *kn, sbintime_t to); 180 static void filt_timertouch(struct knote *kn, struct kevent *kev, 181 u_long type); 182 static int filt_timercopy(struct knote *kn, struct proc *p1); 183 static int filt_timervalidate(struct knote *kn, sbintime_t *to); 184 static int filt_timer(struct knote *kn, long hint); 185 static int filt_userattach(struct knote *kn); 186 static void filt_userdetach(struct knote *kn); 187 static int filt_user(struct knote *kn, long hint); 188 static void filt_usertouch(struct knote *kn, struct kevent *kev, 189 u_long type); 190 191 static const struct filterops file_filtops = { 192 .f_isfd = 1, 193 .f_attach = filt_fileattach, 194 .f_copy = knote_triv_copy, 195 }; 196 static const struct filterops kqread_filtops = { 197 .f_isfd = 1, 198 .f_detach = filt_kqdetach, 199 .f_event = filt_kqueue, 200 .f_copy = knote_triv_copy, 201 }; 202 /* XXX - move to kern_proc.c? */ 203 static const struct filterops proc_filtops = { 204 .f_isfd = 0, 205 .f_attach = filt_procattach, 206 .f_detach = filt_procdetach, 207 .f_event = filt_proc, 208 .f_copy = knote_triv_copy, 209 }; 210 static const struct filterops jail_filtops = { 211 .f_isfd = 0, 212 .f_attach = filt_jailattach, 213 .f_detach = filt_jaildetach, 214 .f_event = filt_jail, 215 .f_copy = knote_triv_copy, 216 }; 217 static const struct filterops timer_filtops = { 218 .f_isfd = 0, 219 .f_attach = filt_timerattach, 220 .f_detach = filt_timerdetach, 221 .f_event = filt_timer, 222 .f_touch = filt_timertouch, 223 .f_copy = filt_timercopy, 224 }; 225 static const struct filterops user_filtops = { 226 .f_attach = filt_userattach, 227 .f_detach = filt_userdetach, 228 .f_event = filt_user, 229 .f_touch = filt_usertouch, 230 .f_copy = knote_triv_copy, 231 }; 232 233 static uma_zone_t knote_zone; 234 static unsigned int __exclusive_cache_line kq_ncallouts; 235 static unsigned int kq_calloutmax = 4 * 1024; 236 SYSCTL_UINT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW, 237 &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue"); 238 239 /* XXX - ensure not influx ? */ 240 #define KNOTE_ACTIVATE(kn, islock) do { \ 241 if ((islock)) \ 242 mtx_assert(&(kn)->kn_kq->kq_lock, MA_OWNED); \ 243 else \ 244 KQ_LOCK((kn)->kn_kq); \ 245 (kn)->kn_status |= KN_ACTIVE; \ 246 if (((kn)->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 247 knote_enqueue((kn)); \ 248 if (!(islock)) \ 249 KQ_UNLOCK((kn)->kn_kq); \ 250 } while (0) 251 #define KQ_LOCK(kq) do { \ 252 mtx_lock(&(kq)->kq_lock); \ 253 } while (0) 254 #define KQ_FLUX_WAKEUP(kq) do { \ 255 if (((kq)->kq_state & KQ_FLUXWAIT) == KQ_FLUXWAIT) { \ 256 (kq)->kq_state &= ~KQ_FLUXWAIT; \ 257 wakeup((kq)); \ 258 } \ 259 } while (0) 260 #define KQ_UNLOCK_FLUX(kq) do { \ 261 KQ_FLUX_WAKEUP(kq); \ 262 mtx_unlock(&(kq)->kq_lock); \ 263 } while (0) 264 #define KQ_UNLOCK(kq) do { \ 265 mtx_unlock(&(kq)->kq_lock); \ 266 } while (0) 267 #define KQ_OWNED(kq) do { \ 268 mtx_assert(&(kq)->kq_lock, MA_OWNED); \ 269 } while (0) 270 #define KQ_NOTOWNED(kq) do { \ 271 mtx_assert(&(kq)->kq_lock, MA_NOTOWNED); \ 272 } while (0) 273 274 static struct knlist * 275 kn_list_lock(struct knote *kn) 276 { 277 struct knlist *knl; 278 279 knl = kn->kn_knlist; 280 if (knl != NULL) 281 knl->kl_lock(knl->kl_lockarg); 282 return (knl); 283 } 284 285 static void 286 kn_list_unlock(struct knlist *knl) 287 { 288 bool do_free; 289 290 if (knl == NULL) 291 return; 292 do_free = knl->kl_autodestroy && knlist_empty(knl); 293 knl->kl_unlock(knl->kl_lockarg); 294 if (do_free) { 295 knlist_destroy(knl); 296 free(knl, M_KQUEUE); 297 } 298 } 299 300 static bool 301 kn_in_flux(struct knote *kn) 302 { 303 304 return (kn->kn_influx > 0); 305 } 306 307 static void 308 kn_enter_flux(struct knote *kn) 309 { 310 311 KQ_OWNED(kn->kn_kq); 312 MPASS(kn->kn_influx < INT_MAX); 313 kn->kn_influx++; 314 } 315 316 static bool 317 kn_leave_flux(struct knote *kn) 318 { 319 320 KQ_OWNED(kn->kn_kq); 321 MPASS(kn->kn_influx > 0); 322 kn->kn_influx--; 323 return (kn->kn_influx == 0); 324 } 325 326 #define KNL_ASSERT_LOCK(knl, islocked) do { \ 327 if (islocked) \ 328 KNL_ASSERT_LOCKED(knl); \ 329 else \ 330 KNL_ASSERT_UNLOCKED(knl); \ 331 } while (0) 332 #ifdef INVARIANTS 333 #define KNL_ASSERT_LOCKED(knl) do { \ 334 knl->kl_assert_lock((knl)->kl_lockarg, LA_LOCKED); \ 335 } while (0) 336 #define KNL_ASSERT_UNLOCKED(knl) do { \ 337 knl->kl_assert_lock((knl)->kl_lockarg, LA_UNLOCKED); \ 338 } while (0) 339 #else /* !INVARIANTS */ 340 #define KNL_ASSERT_LOCKED(knl) do {} while (0) 341 #define KNL_ASSERT_UNLOCKED(knl) do {} while (0) 342 #endif /* INVARIANTS */ 343 344 #ifndef KN_HASHSIZE 345 #define KN_HASHSIZE 64 /* XXX should be tunable */ 346 #endif 347 348 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 349 350 static int 351 filt_nullattach(struct knote *kn) 352 { 353 354 return (ENXIO); 355 }; 356 357 static const struct filterops null_filtops = { 358 .f_isfd = 0, 359 .f_attach = filt_nullattach, 360 .f_copy = knote_triv_copy, 361 }; 362 363 /* XXX - make SYSINIT to add these, and move into respective modules. */ 364 extern const struct filterops sig_filtops; 365 extern const struct filterops fs_filtops; 366 367 /* 368 * Table for all system-defined filters. 369 */ 370 static struct mtx filterops_lock; 371 MTX_SYSINIT(kqueue_filterops, &filterops_lock, "protect sysfilt_ops", MTX_DEF); 372 static struct { 373 const struct filterops *for_fop; 374 int for_nolock; 375 int for_refcnt; 376 } sysfilt_ops[EVFILT_SYSCOUNT] = { 377 [~EVFILT_READ] = { &file_filtops, 1 }, 378 [~EVFILT_WRITE] = { &file_filtops, 1 }, 379 [~EVFILT_AIO] = { &null_filtops }, 380 [~EVFILT_VNODE] = { &file_filtops, 1 }, 381 [~EVFILT_PROC] = { &proc_filtops, 1 }, 382 [~EVFILT_SIGNAL] = { &sig_filtops, 1 }, 383 [~EVFILT_TIMER] = { &timer_filtops, 1 }, 384 [~EVFILT_PROCDESC] = { &file_filtops, 1 }, 385 [~EVFILT_FS] = { &fs_filtops, 1 }, 386 [~EVFILT_LIO] = { &null_filtops }, 387 [~EVFILT_USER] = { &user_filtops, 1 }, 388 [~EVFILT_SENDFILE] = { &null_filtops }, 389 [~EVFILT_EMPTY] = { &file_filtops, 1 }, 390 [~EVFILT_JAIL] = { &jail_filtops, 1 }, 391 [~EVFILT_JAILDESC] = { &file_filtops, 1 }, 392 }; 393 394 /* 395 * Simple redirection for all cdevsw style objects to call their fo_kqfilter 396 * method. 397 */ 398 static int 399 filt_fileattach(struct knote *kn) 400 { 401 402 return (fo_kqfilter(kn->kn_fp, kn)); 403 } 404 405 /*ARGSUSED*/ 406 static int 407 kqueue_kqfilter(struct file *fp, struct knote *kn) 408 { 409 struct kqueue *kq = kn->kn_fp->f_data; 410 411 if (kn->kn_filter != EVFILT_READ) 412 return (EINVAL); 413 414 kn->kn_status |= KN_KQUEUE; 415 kn->kn_fop = &kqread_filtops; 416 knlist_add(&kq->kq_sel.si_note, kn, 0); 417 418 return (0); 419 } 420 421 static void 422 filt_kqdetach(struct knote *kn) 423 { 424 struct kqueue *kq = kn->kn_fp->f_data; 425 426 knlist_remove(&kq->kq_sel.si_note, kn, 0); 427 } 428 429 /*ARGSUSED*/ 430 static int 431 filt_kqueue(struct knote *kn, long hint) 432 { 433 struct kqueue *kq = kn->kn_fp->f_data; 434 435 kn->kn_data = kq->kq_count; 436 return (kn->kn_data > 0); 437 } 438 439 /* XXX - move to kern_proc.c? */ 440 static int 441 filt_procattach(struct knote *kn) 442 { 443 struct proc *p; 444 int error; 445 bool exiting, immediate; 446 447 exiting = immediate = false; 448 if (kn->kn_sfflags & NOTE_EXIT) 449 p = pfind_any(kn->kn_id); 450 else 451 p = pfind(kn->kn_id); 452 if (p == NULL) 453 return (ESRCH); 454 if (p->p_flag & P_WEXIT) 455 exiting = true; 456 457 if ((error = p_cansee(curthread, p))) { 458 PROC_UNLOCK(p); 459 return (error); 460 } 461 462 kn->kn_ptr.p_proc = p; 463 kn->kn_flags |= EV_CLEAR; /* automatically set */ 464 465 /* 466 * Internal flag indicating registration done by kernel for the 467 * purposes of getting a NOTE_CHILD notification. 468 */ 469 if (kn->kn_flags & EV_FLAG2) { 470 kn->kn_flags &= ~EV_FLAG2; 471 kn->kn_data = kn->kn_sdata; /* ppid */ 472 kn->kn_fflags = NOTE_CHILD; 473 kn->kn_sfflags &= ~(NOTE_EXIT | NOTE_EXEC | NOTE_FORK); 474 immediate = true; /* Force immediate activation of child note. */ 475 } 476 /* 477 * Internal flag indicating registration done by kernel (for other than 478 * NOTE_CHILD). 479 */ 480 if (kn->kn_flags & EV_FLAG1) { 481 kn->kn_flags &= ~EV_FLAG1; 482 } 483 484 knlist_add(p->p_klist, kn, 1); 485 486 /* 487 * Immediately activate any child notes or, in the case of a zombie 488 * target process, exit notes. The latter is necessary to handle the 489 * case where the target process, e.g. a child, dies before the kevent 490 * is registered. 491 */ 492 if (immediate || (exiting && filt_proc(kn, NOTE_EXIT))) 493 KNOTE_ACTIVATE(kn, 0); 494 495 PROC_UNLOCK(p); 496 497 return (0); 498 } 499 500 /* 501 * The knote may be attached to a different process, which may exit, 502 * leaving nothing for the knote to be attached to. So when the process 503 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 504 * it will be deleted when read out. However, as part of the knote deletion, 505 * this routine is called, so a check is needed to avoid actually performing 506 * a detach, because the original process does not exist any more. 507 */ 508 /* XXX - move to kern_proc.c? */ 509 static void 510 filt_procdetach(struct knote *kn) 511 { 512 513 knlist_remove(kn->kn_knlist, kn, 0); 514 kn->kn_ptr.p_proc = NULL; 515 } 516 517 /* XXX - move to kern_proc.c? */ 518 static int 519 filt_proc(struct knote *kn, long hint) 520 { 521 struct proc *p; 522 u_int event; 523 524 p = kn->kn_ptr.p_proc; 525 if (p == NULL) /* already activated, from attach filter */ 526 return (0); 527 528 /* Mask off extra data. */ 529 event = (u_int)hint & NOTE_PCTRLMASK; 530 531 /* If the user is interested in this event, record it. */ 532 if (kn->kn_sfflags & event) 533 kn->kn_fflags |= event; 534 535 /* Process is gone, so flag the event as finished. */ 536 if (event == NOTE_EXIT) { 537 kn->kn_flags |= EV_EOF | EV_ONESHOT; 538 kn->kn_ptr.p_proc = NULL; 539 if (kn->kn_fflags & NOTE_EXIT) 540 kn->kn_data = KW_EXITCODE(p->p_xexit, p->p_xsig); 541 if (kn->kn_fflags == 0) 542 kn->kn_flags |= EV_DROP; 543 return (1); 544 } 545 546 return (kn->kn_fflags != 0); 547 } 548 549 /* 550 * Called when the process forked. It mostly does the same as the 551 * knote(), activating all knotes registered to be activated when the 552 * process forked. Additionally, for each knote attached to the 553 * parent, check whether user wants to track the new process. If so 554 * attach a new knote to it, and immediately report an event with the 555 * child's pid. 556 */ 557 void 558 knote_fork(struct knlist *list, int pid) 559 { 560 struct kqueue *kq; 561 struct knote *kn; 562 struct kevent kev; 563 int error; 564 565 MPASS(list != NULL); 566 KNL_ASSERT_LOCKED(list); 567 if (SLIST_EMPTY(&list->kl_list)) 568 return; 569 570 memset(&kev, 0, sizeof(kev)); 571 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { 572 kq = kn->kn_kq; 573 KQ_LOCK(kq); 574 if (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0) { 575 KQ_UNLOCK(kq); 576 continue; 577 } 578 579 /* 580 * The same as knote(), activate the event. 581 */ 582 if ((kn->kn_sfflags & NOTE_TRACK) == 0) { 583 if (kn->kn_fop->f_event(kn, NOTE_FORK)) 584 KNOTE_ACTIVATE(kn, 1); 585 KQ_UNLOCK(kq); 586 continue; 587 } 588 589 /* 590 * The NOTE_TRACK case. In addition to the activation 591 * of the event, we need to register new events to 592 * track the child. Drop the locks in preparation for 593 * the call to kqueue_register(). 594 */ 595 kn_enter_flux(kn); 596 KQ_UNLOCK(kq); 597 list->kl_unlock(list->kl_lockarg); 598 599 /* 600 * Activate existing knote and register tracking knotes with 601 * new process. 602 * 603 * First register a knote to get just the child notice. This 604 * must be a separate note from a potential NOTE_EXIT 605 * notification since both NOTE_CHILD and NOTE_EXIT are defined 606 * to use the data field (in conflicting ways). 607 */ 608 kev.ident = pid; 609 kev.filter = kn->kn_filter; 610 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_ONESHOT | 611 EV_FLAG2; 612 kev.fflags = kn->kn_sfflags; 613 kev.data = kn->kn_id; /* parent */ 614 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 615 error = kqueue_register(kq, &kev, NULL, M_NOWAIT); 616 if (error) 617 kn->kn_fflags |= NOTE_TRACKERR; 618 619 /* 620 * Then register another knote to track other potential events 621 * from the new process. 622 */ 623 kev.ident = pid; 624 kev.filter = kn->kn_filter; 625 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 626 kev.fflags = kn->kn_sfflags; 627 kev.data = kn->kn_id; /* parent */ 628 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 629 error = kqueue_register(kq, &kev, NULL, M_NOWAIT); 630 631 /* 632 * Serialize updates to the kn_kevent fields with threads 633 * scanning the queue. 634 */ 635 list->kl_lock(list->kl_lockarg); 636 if (error) 637 kn->kn_fflags |= NOTE_TRACKERR; 638 if (kn->kn_fop->f_event(kn, NOTE_FORK)) { 639 KQ_LOCK(kq); 640 KNOTE_ACTIVATE(kn, 1); 641 } else { 642 KQ_LOCK(kq); 643 } 644 kn_leave_flux(kn); 645 KQ_UNLOCK_FLUX(kq); 646 } 647 } 648 649 int 650 filt_jailattach(struct knote *kn) 651 { 652 struct prison *pr; 653 654 if (kn->kn_id == 0) { 655 /* Let jid=0 watch the current prison (including prison0). */ 656 pr = curthread->td_ucred->cr_prison; 657 mtx_lock(&pr->pr_mtx); 658 } else { 659 sx_slock(&allprison_lock); 660 pr = prison_find_child(curthread->td_ucred->cr_prison, 661 kn->kn_id); 662 sx_sunlock(&allprison_lock); 663 if (pr == NULL) 664 return (ENOENT); 665 if (!prison_isalive(pr)) { 666 mtx_unlock(&pr->pr_mtx); 667 return (ENOENT); 668 } 669 } 670 kn->kn_ptr.p_prison = pr; 671 kn->kn_flags |= EV_CLEAR; 672 knlist_add(pr->pr_klist, kn, 1); 673 mtx_unlock(&pr->pr_mtx); 674 return (0); 675 } 676 677 void 678 filt_jaildetach(struct knote *kn) 679 { 680 if (kn->kn_ptr.p_prison != NULL) { 681 knlist_remove(kn->kn_knlist, kn, 0); 682 kn->kn_ptr.p_prison = NULL; 683 } else 684 kn->kn_status |= KN_DETACHED; 685 } 686 687 int 688 filt_jail(struct knote *kn, long hint) 689 { 690 struct prison *pr; 691 u_int event; 692 693 pr = kn->kn_ptr.p_prison; 694 if (pr == NULL) /* already activated, from attach filter */ 695 return (0); 696 697 /* 698 * Mask off extra data. In the NOTE_JAIL_CHILD case, that's 699 * everything except the NOTE_JAIL_CHILD bit itself, since a 700 * JID is any positive integer. 701 */ 702 event = ((u_int)hint & NOTE_JAIL_CHILD) ? NOTE_JAIL_CHILD : 703 (u_int)hint & NOTE_JAIL_CTRLMASK; 704 705 /* If the user is interested in this event, record it. */ 706 if (kn->kn_sfflags & event) { 707 kn->kn_fflags |= event; 708 /* Report the created jail id or attached process id. */ 709 if (event == NOTE_JAIL_CHILD || event == NOTE_JAIL_ATTACH) { 710 if (kn->kn_data != 0) 711 kn->kn_fflags |= NOTE_JAIL_MULTI; 712 kn->kn_data = (kn->kn_fflags & NOTE_JAIL_MULTI) ? 0U : 713 (u_int)hint & ~event; 714 } 715 } 716 717 /* Prison is gone, so flag the event as finished. */ 718 if (event == NOTE_JAIL_REMOVE) { 719 kn->kn_flags |= EV_EOF | EV_ONESHOT; 720 kn->kn_ptr.p_prison = NULL; 721 if (kn->kn_fflags == 0) 722 kn->kn_flags |= EV_DROP; 723 return (1); 724 } 725 726 return (kn->kn_fflags != 0); 727 } 728 729 /* 730 * XXX: EVFILT_TIMER should perhaps live in kern_time.c beside the 731 * interval timer support code. 732 */ 733 734 #define NOTE_TIMER_PRECMASK \ 735 (NOTE_SECONDS | NOTE_MSECONDS | NOTE_USECONDS | NOTE_NSECONDS) 736 737 static sbintime_t 738 timer2sbintime(int64_t data, int flags) 739 { 740 int64_t secs; 741 742 /* 743 * Macros for converting to the fractional second portion of an 744 * sbintime_t using 64bit multiplication to improve precision. 745 */ 746 #define NS_TO_SBT(ns) (((ns) * (((uint64_t)1 << 63) / 500000000)) >> 32) 747 #define US_TO_SBT(us) (((us) * (((uint64_t)1 << 63) / 500000)) >> 32) 748 #define MS_TO_SBT(ms) (((ms) * (((uint64_t)1 << 63) / 500)) >> 32) 749 switch (flags & NOTE_TIMER_PRECMASK) { 750 case NOTE_SECONDS: 751 #ifdef __LP64__ 752 if (data > (SBT_MAX / SBT_1S)) 753 return (SBT_MAX); 754 #endif 755 return ((sbintime_t)data << 32); 756 case NOTE_MSECONDS: /* FALLTHROUGH */ 757 case 0: 758 if (data >= 1000) { 759 secs = data / 1000; 760 #ifdef __LP64__ 761 if (secs > (SBT_MAX / SBT_1S)) 762 return (SBT_MAX); 763 #endif 764 return (secs << 32 | MS_TO_SBT(data % 1000)); 765 } 766 return (MS_TO_SBT(data)); 767 case NOTE_USECONDS: 768 if (data >= 1000000) { 769 secs = data / 1000000; 770 #ifdef __LP64__ 771 if (secs > (SBT_MAX / SBT_1S)) 772 return (SBT_MAX); 773 #endif 774 return (secs << 32 | US_TO_SBT(data % 1000000)); 775 } 776 return (US_TO_SBT(data)); 777 case NOTE_NSECONDS: 778 if (data >= 1000000000) { 779 secs = data / 1000000000; 780 #ifdef __LP64__ 781 if (secs > (SBT_MAX / SBT_1S)) 782 return (SBT_MAX); 783 #endif 784 return (secs << 32 | NS_TO_SBT(data % 1000000000)); 785 } 786 return (NS_TO_SBT(data)); 787 default: 788 break; 789 } 790 return (-1); 791 } 792 793 struct kq_timer_cb_data { 794 struct callout c; 795 struct proc *p; 796 struct knote *kn; 797 int cpuid; 798 int flags; 799 TAILQ_ENTRY(kq_timer_cb_data) link; 800 sbintime_t next; /* next timer event fires at */ 801 sbintime_t to; /* precalculated timer period, 0 for abs */ 802 }; 803 804 #define KQ_TIMER_CB_ENQUEUED 0x01 805 806 static void 807 kqtimer_sched_callout(struct kq_timer_cb_data *kc) 808 { 809 callout_reset_sbt_on(&kc->c, kc->next, 0, filt_timerexpire, kc->kn, 810 kc->cpuid, C_ABSOLUTE); 811 } 812 813 void 814 kqtimer_proc_continue(struct proc *p) 815 { 816 struct kq_timer_cb_data *kc, *kc1; 817 sbintime_t now; 818 819 PROC_LOCK_ASSERT(p, MA_OWNED); 820 821 now = sbinuptime(); 822 TAILQ_FOREACH_SAFE(kc, &p->p_kqtim_stop, link, kc1) { 823 TAILQ_REMOVE(&p->p_kqtim_stop, kc, link); 824 kc->flags &= ~KQ_TIMER_CB_ENQUEUED; 825 if (kc->next <= now) 826 filt_timerexpire_l(kc->kn, true); 827 else 828 kqtimer_sched_callout(kc); 829 } 830 } 831 832 static void 833 filt_timerexpire_l(struct knote *kn, bool proc_locked) 834 { 835 struct kq_timer_cb_data *kc; 836 struct proc *p; 837 uint64_t delta; 838 sbintime_t now; 839 840 kc = kn->kn_ptr.p_v; 841 842 if ((kn->kn_flags & EV_ONESHOT) != 0 || kc->to == 0) { 843 kn->kn_data++; 844 KNOTE_ACTIVATE(kn, 0); 845 return; 846 } 847 848 now = sbinuptime(); 849 if (now >= kc->next) { 850 delta = (now - kc->next) / kc->to; 851 if (delta == 0) 852 delta = 1; 853 kn->kn_data += delta; 854 kc->next += delta * kc->to; 855 if (now >= kc->next) /* overflow */ 856 kc->next = now + kc->to; 857 KNOTE_ACTIVATE(kn, 0); /* XXX - handle locking */ 858 } 859 860 /* 861 * Initial check for stopped kc->p is racy. It is fine to 862 * miss the set of the stop flags, at worst we would schedule 863 * one more callout. On the other hand, it is not fine to not 864 * schedule when we we missed clearing of the flags, we 865 * recheck them under the lock and observe consistent state. 866 */ 867 p = kc->p; 868 if (P_SHOULDSTOP(p) || P_KILLED(p)) { 869 if (!proc_locked) 870 PROC_LOCK(p); 871 if (P_SHOULDSTOP(p) || P_KILLED(p)) { 872 if ((kc->flags & KQ_TIMER_CB_ENQUEUED) == 0) { 873 /* 874 * Insert into head so that 875 * kqtimer_proc_continue() does not 876 * iterate into us again. 877 */ 878 kc->flags |= KQ_TIMER_CB_ENQUEUED; 879 TAILQ_INSERT_HEAD(&p->p_kqtim_stop, kc, link); 880 } 881 if (!proc_locked) 882 PROC_UNLOCK(p); 883 return; 884 } 885 if (!proc_locked) 886 PROC_UNLOCK(p); 887 } 888 kqtimer_sched_callout(kc); 889 } 890 891 static void 892 filt_timerexpire(void *knx) 893 { 894 filt_timerexpire_l(knx, false); 895 } 896 897 /* 898 * data contains amount of time to sleep 899 */ 900 static int 901 filt_timervalidate(struct knote *kn, sbintime_t *to) 902 { 903 struct bintime bt; 904 sbintime_t sbt; 905 906 if (kn->kn_sdata < 0) 907 return (EINVAL); 908 if (kn->kn_sdata == 0 && (kn->kn_flags & EV_ONESHOT) == 0) 909 kn->kn_sdata = 1; 910 /* 911 * The only fflags values supported are the timer unit 912 * (precision) and the absolute time indicator. 913 */ 914 if ((kn->kn_sfflags & ~(NOTE_TIMER_PRECMASK | NOTE_ABSTIME)) != 0) 915 return (EINVAL); 916 917 *to = timer2sbintime(kn->kn_sdata, kn->kn_sfflags); 918 if (*to < 0) 919 return (EINVAL); 920 if ((kn->kn_sfflags & NOTE_ABSTIME) != 0) { 921 getboottimebin(&bt); 922 sbt = bttosbt(bt); 923 *to = MAX(0, *to - sbt); 924 } 925 return (0); 926 } 927 928 static int 929 filt_timerattach(struct knote *kn) 930 { 931 struct kq_timer_cb_data *kc; 932 sbintime_t to; 933 int error; 934 935 to = -1; 936 error = filt_timervalidate(kn, &to); 937 if (error != 0) 938 return (error); 939 KASSERT(to > 0 || (kn->kn_flags & EV_ONESHOT) != 0 || 940 (kn->kn_sfflags & NOTE_ABSTIME) != 0, 941 ("%s: periodic timer has a calculated zero timeout", __func__)); 942 KASSERT(to >= 0, 943 ("%s: timer has a calculated negative timeout", __func__)); 944 945 if (atomic_fetchadd_int(&kq_ncallouts, 1) + 1 > kq_calloutmax) { 946 atomic_subtract_int(&kq_ncallouts, 1); 947 return (ENOMEM); 948 } 949 950 if ((kn->kn_sfflags & NOTE_ABSTIME) == 0) 951 kn->kn_flags |= EV_CLEAR; /* automatically set */ 952 kn->kn_status &= ~KN_DETACHED; /* knlist_add clears it */ 953 kn->kn_ptr.p_v = kc = malloc(sizeof(*kc), M_KQUEUE, M_WAITOK); 954 kc->kn = kn; 955 kc->p = curproc; 956 kc->cpuid = PCPU_GET(cpuid); 957 kc->flags = 0; 958 callout_init(&kc->c, 1); 959 filt_timerstart(kn, to); 960 961 return (0); 962 } 963 964 static int 965 filt_timercopy(struct knote *kn, struct proc *p) 966 { 967 struct kq_timer_cb_data *kc_src, *kc; 968 969 if (atomic_fetchadd_int(&kq_ncallouts, 1) + 1 > kq_calloutmax) { 970 atomic_subtract_int(&kq_ncallouts, 1); 971 return (ENOMEM); 972 } 973 974 kn->kn_status &= ~KN_DETACHED; 975 kc_src = kn->kn_ptr.p_v; 976 kn->kn_ptr.p_v = kc = malloc(sizeof(*kc), M_KQUEUE, M_WAITOK); 977 kc->kn = kn; 978 kc->p = p; 979 kc->flags = kc_src->flags & ~KQ_TIMER_CB_ENQUEUED; 980 kc->next = kc_src->next; 981 kc->to = kc_src->to; 982 kc->cpuid = PCPU_GET(cpuid); 983 callout_init(&kc->c, 1); 984 kqtimer_sched_callout(kc); 985 return (0); 986 } 987 988 static void 989 filt_timerstart(struct knote *kn, sbintime_t to) 990 { 991 struct kq_timer_cb_data *kc; 992 993 kc = kn->kn_ptr.p_v; 994 if ((kn->kn_sfflags & NOTE_ABSTIME) != 0) { 995 kc->next = to; 996 kc->to = 0; 997 } else { 998 kc->next = to + sbinuptime(); 999 kc->to = to; 1000 } 1001 kqtimer_sched_callout(kc); 1002 } 1003 1004 static void 1005 filt_timerdetach(struct knote *kn) 1006 { 1007 struct kq_timer_cb_data *kc; 1008 unsigned int old __unused; 1009 bool pending; 1010 1011 kc = kn->kn_ptr.p_v; 1012 do { 1013 callout_drain(&kc->c); 1014 1015 /* 1016 * kqtimer_proc_continue() might have rescheduled this callout. 1017 * Double-check, using the process mutex as an interlock. 1018 */ 1019 PROC_LOCK(kc->p); 1020 if ((kc->flags & KQ_TIMER_CB_ENQUEUED) != 0) { 1021 kc->flags &= ~KQ_TIMER_CB_ENQUEUED; 1022 TAILQ_REMOVE(&kc->p->p_kqtim_stop, kc, link); 1023 } 1024 pending = callout_pending(&kc->c); 1025 PROC_UNLOCK(kc->p); 1026 } while (pending); 1027 free(kc, M_KQUEUE); 1028 old = atomic_fetchadd_int(&kq_ncallouts, -1); 1029 KASSERT(old > 0, ("Number of callouts cannot become negative")); 1030 kn->kn_status |= KN_DETACHED; /* knlist_remove sets it */ 1031 } 1032 1033 static void 1034 filt_timertouch(struct knote *kn, struct kevent *kev, u_long type) 1035 { 1036 struct kq_timer_cb_data *kc; 1037 struct kqueue *kq; 1038 sbintime_t to; 1039 int error; 1040 1041 switch (type) { 1042 case EVENT_REGISTER: 1043 /* Handle re-added timers that update data/fflags */ 1044 if (kev->flags & EV_ADD) { 1045 kc = kn->kn_ptr.p_v; 1046 1047 /* Drain any existing callout. */ 1048 callout_drain(&kc->c); 1049 1050 /* Throw away any existing undelivered record 1051 * of the timer expiration. This is done under 1052 * the presumption that if a process is 1053 * re-adding this timer with new parameters, 1054 * it is no longer interested in what may have 1055 * happened under the old parameters. If it is 1056 * interested, it can wait for the expiration, 1057 * delete the old timer definition, and then 1058 * add the new one. 1059 * 1060 * This has to be done while the kq is locked: 1061 * - if enqueued, dequeue 1062 * - make it no longer active 1063 * - clear the count of expiration events 1064 */ 1065 kq = kn->kn_kq; 1066 KQ_LOCK(kq); 1067 if (kn->kn_status & KN_QUEUED) 1068 knote_dequeue(kn); 1069 1070 kn->kn_status &= ~KN_ACTIVE; 1071 kn->kn_data = 0; 1072 KQ_UNLOCK(kq); 1073 1074 /* Reschedule timer based on new data/fflags */ 1075 kn->kn_sfflags = kev->fflags; 1076 kn->kn_sdata = kev->data; 1077 error = filt_timervalidate(kn, &to); 1078 if (error != 0) { 1079 kn->kn_flags |= EV_ERROR; 1080 kn->kn_data = error; 1081 } else 1082 filt_timerstart(kn, to); 1083 } 1084 break; 1085 1086 case EVENT_PROCESS: 1087 *kev = kn->kn_kevent; 1088 if (kn->kn_flags & EV_CLEAR) { 1089 kn->kn_data = 0; 1090 kn->kn_fflags = 0; 1091 } 1092 break; 1093 1094 default: 1095 panic("filt_timertouch() - invalid type (%ld)", type); 1096 break; 1097 } 1098 } 1099 1100 static int 1101 filt_timer(struct knote *kn, long hint) 1102 { 1103 1104 return (kn->kn_data != 0); 1105 } 1106 1107 static int 1108 filt_userattach(struct knote *kn) 1109 { 1110 1111 /* 1112 * EVFILT_USER knotes are not attached to anything in the kernel. 1113 */ 1114 kn->kn_hook = NULL; 1115 if (kn->kn_fflags & NOTE_TRIGGER) 1116 kn->kn_hookid = 1; 1117 else 1118 kn->kn_hookid = 0; 1119 return (0); 1120 } 1121 1122 static void 1123 filt_userdetach(__unused struct knote *kn) 1124 { 1125 1126 /* 1127 * EVFILT_USER knotes are not attached to anything in the kernel. 1128 */ 1129 } 1130 1131 static int 1132 filt_user(struct knote *kn, __unused long hint) 1133 { 1134 1135 return (kn->kn_hookid); 1136 } 1137 1138 static void 1139 filt_usertouch(struct knote *kn, struct kevent *kev, u_long type) 1140 { 1141 u_int ffctrl; 1142 1143 switch (type) { 1144 case EVENT_REGISTER: 1145 if (kev->fflags & NOTE_TRIGGER) 1146 kn->kn_hookid = 1; 1147 1148 ffctrl = kev->fflags & NOTE_FFCTRLMASK; 1149 kev->fflags &= NOTE_FFLAGSMASK; 1150 switch (ffctrl) { 1151 case NOTE_FFNOP: 1152 break; 1153 1154 case NOTE_FFAND: 1155 kn->kn_sfflags &= kev->fflags; 1156 break; 1157 1158 case NOTE_FFOR: 1159 kn->kn_sfflags |= kev->fflags; 1160 break; 1161 1162 case NOTE_FFCOPY: 1163 kn->kn_sfflags = kev->fflags; 1164 break; 1165 1166 default: 1167 /* XXX Return error? */ 1168 break; 1169 } 1170 kn->kn_sdata = kev->data; 1171 if (kev->flags & EV_CLEAR) { 1172 kn->kn_hookid = 0; 1173 kn->kn_data = 0; 1174 kn->kn_fflags = 0; 1175 } 1176 break; 1177 1178 case EVENT_PROCESS: 1179 *kev = kn->kn_kevent; 1180 kev->fflags = kn->kn_sfflags; 1181 kev->data = kn->kn_sdata; 1182 if (kn->kn_flags & EV_CLEAR) { 1183 kn->kn_hookid = 0; 1184 kn->kn_data = 0; 1185 kn->kn_fflags = 0; 1186 } 1187 break; 1188 1189 default: 1190 panic("filt_usertouch() - invalid type (%ld)", type); 1191 break; 1192 } 1193 } 1194 1195 int 1196 sys_kqueue(struct thread *td, struct kqueue_args *uap) 1197 { 1198 1199 return (kern_kqueue(td, 0, false, NULL)); 1200 } 1201 1202 int 1203 sys_kqueuex(struct thread *td, struct kqueuex_args *uap) 1204 { 1205 int flags; 1206 1207 if ((uap->flags & ~(KQUEUE_CLOEXEC | KQUEUE_CPONFORK)) != 0) 1208 return (EINVAL); 1209 flags = 0; 1210 if ((uap->flags & KQUEUE_CLOEXEC) != 0) 1211 flags |= O_CLOEXEC; 1212 return (kern_kqueue(td, flags, (uap->flags & KQUEUE_CPONFORK) != 0, 1213 NULL)); 1214 } 1215 1216 static void 1217 kqueue_init(struct kqueue *kq, bool cponfork) 1218 { 1219 1220 mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF | MTX_DUPOK); 1221 TAILQ_INIT(&kq->kq_head); 1222 knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock); 1223 TASK_INIT(&kq->kq_task, 0, kqueue_task, kq); 1224 if (cponfork) 1225 kq->kq_state |= KQ_CPONFORK; 1226 } 1227 1228 static int 1229 kern_kqueue_alloc(struct thread *td, struct filedesc *fdp, int *fdip, 1230 struct file **fpp, int flags, struct filecaps *fcaps, bool cponfork, 1231 struct kqueue **kqp) 1232 { 1233 struct ucred *cred; 1234 struct kqueue *kq; 1235 int error; 1236 1237 cred = td->td_ucred; 1238 if (!chgkqcnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_KQUEUES))) 1239 return (ENOMEM); 1240 1241 error = fdip != NULL ? falloc_caps(td, fpp, fdip, flags, fcaps) : 1242 _falloc_noinstall(td, fpp, 1); 1243 if (error != 0) { 1244 chgkqcnt(cred->cr_ruidinfo, -1, 0); 1245 return (error); 1246 } 1247 1248 /* An extra reference on `fp' has been held for us by falloc(). */ 1249 kq = malloc(sizeof(*kq), M_KQUEUE, M_WAITOK | M_ZERO); 1250 kqueue_init(kq, cponfork); 1251 kq->kq_fdp = fdp; 1252 kq->kq_cred = crhold(cred); 1253 1254 if (fdip != NULL) 1255 FILEDESC_XLOCK(fdp); 1256 TAILQ_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list); 1257 if (fdip != NULL) 1258 FILEDESC_XUNLOCK(fdp); 1259 1260 finit(*fpp, FREAD | FWRITE, DTYPE_KQUEUE, kq, &kqueueops); 1261 *kqp = kq; 1262 return (0); 1263 } 1264 1265 int 1266 kern_kqueue(struct thread *td, int flags, bool cponfork, struct filecaps *fcaps) 1267 { 1268 struct kqueue *kq; 1269 struct file *fp; 1270 int fd, error; 1271 1272 error = kern_kqueue_alloc(td, td->td_proc->p_fd, &fd, &fp, flags, 1273 fcaps, cponfork, &kq); 1274 if (error != 0) 1275 return (error); 1276 1277 fdrop(fp, td); 1278 1279 td->td_retval[0] = fd; 1280 return (0); 1281 } 1282 1283 struct g_kevent_args { 1284 int fd; 1285 const void *changelist; 1286 int nchanges; 1287 void *eventlist; 1288 int nevents; 1289 const struct timespec *timeout; 1290 }; 1291 1292 int 1293 sys_kevent(struct thread *td, struct kevent_args *uap) 1294 { 1295 struct kevent_copyops k_ops = { 1296 .arg = uap, 1297 .k_copyout = kevent_copyout, 1298 .k_copyin = kevent_copyin, 1299 .kevent_size = sizeof(struct kevent), 1300 }; 1301 struct g_kevent_args gk_args = { 1302 .fd = uap->fd, 1303 .changelist = uap->changelist, 1304 .nchanges = uap->nchanges, 1305 .eventlist = uap->eventlist, 1306 .nevents = uap->nevents, 1307 .timeout = uap->timeout, 1308 }; 1309 1310 return (kern_kevent_generic(td, &gk_args, &k_ops, "kevent")); 1311 } 1312 1313 static int 1314 kern_kevent_generic(struct thread *td, struct g_kevent_args *uap, 1315 struct kevent_copyops *k_ops, const char *struct_name) 1316 { 1317 struct timespec ts, *tsp; 1318 #ifdef KTRACE 1319 struct kevent *eventlist = uap->eventlist; 1320 #endif 1321 int error; 1322 1323 if (uap->timeout != NULL) { 1324 error = copyin(uap->timeout, &ts, sizeof(ts)); 1325 if (error) 1326 return (error); 1327 tsp = &ts; 1328 } else 1329 tsp = NULL; 1330 1331 #ifdef KTRACE 1332 if (KTRPOINT(td, KTR_STRUCT_ARRAY)) 1333 ktrstructarray(struct_name, UIO_USERSPACE, uap->changelist, 1334 uap->nchanges, k_ops->kevent_size); 1335 #endif 1336 1337 error = kern_kevent(td, uap->fd, uap->nchanges, uap->nevents, 1338 k_ops, tsp); 1339 1340 #ifdef KTRACE 1341 if (error == 0 && KTRPOINT(td, KTR_STRUCT_ARRAY)) 1342 ktrstructarray(struct_name, UIO_USERSPACE, eventlist, 1343 td->td_retval[0], k_ops->kevent_size); 1344 #endif 1345 1346 return (error); 1347 } 1348 1349 /* 1350 * Copy 'count' items into the destination list pointed to by uap->eventlist. 1351 */ 1352 static int 1353 kevent_copyout(void *arg, struct kevent *kevp, int count) 1354 { 1355 struct kevent_args *uap; 1356 int error; 1357 1358 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1359 uap = (struct kevent_args *)arg; 1360 1361 error = copyout(kevp, uap->eventlist, count * sizeof *kevp); 1362 if (error == 0) 1363 uap->eventlist += count; 1364 return (error); 1365 } 1366 1367 /* 1368 * Copy 'count' items from the list pointed to by uap->changelist. 1369 */ 1370 static int 1371 kevent_copyin(void *arg, struct kevent *kevp, int count) 1372 { 1373 struct kevent_args *uap; 1374 int error; 1375 1376 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1377 uap = (struct kevent_args *)arg; 1378 1379 error = copyin(uap->changelist, kevp, count * sizeof *kevp); 1380 if (error == 0) 1381 uap->changelist += count; 1382 return (error); 1383 } 1384 1385 #ifdef COMPAT_FREEBSD11 1386 static int 1387 kevent11_copyout(void *arg, struct kevent *kevp, int count) 1388 { 1389 struct freebsd11_kevent_args *uap; 1390 struct freebsd11_kevent kev11; 1391 int error, i; 1392 1393 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1394 uap = (struct freebsd11_kevent_args *)arg; 1395 1396 for (i = 0; i < count; i++) { 1397 kev11.ident = kevp->ident; 1398 kev11.filter = kevp->filter; 1399 kev11.flags = kevp->flags; 1400 kev11.fflags = kevp->fflags; 1401 kev11.data = kevp->data; 1402 kev11.udata = kevp->udata; 1403 error = copyout(&kev11, uap->eventlist, sizeof(kev11)); 1404 if (error != 0) 1405 break; 1406 uap->eventlist++; 1407 kevp++; 1408 } 1409 return (error); 1410 } 1411 1412 /* 1413 * Copy 'count' items from the list pointed to by uap->changelist. 1414 */ 1415 static int 1416 kevent11_copyin(void *arg, struct kevent *kevp, int count) 1417 { 1418 struct freebsd11_kevent_args *uap; 1419 struct freebsd11_kevent kev11; 1420 int error, i; 1421 1422 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1423 uap = (struct freebsd11_kevent_args *)arg; 1424 1425 for (i = 0; i < count; i++) { 1426 error = copyin(uap->changelist, &kev11, sizeof(kev11)); 1427 if (error != 0) 1428 break; 1429 kevp->ident = kev11.ident; 1430 kevp->filter = kev11.filter; 1431 kevp->flags = kev11.flags; 1432 kevp->fflags = kev11.fflags; 1433 kevp->data = (uintptr_t)kev11.data; 1434 kevp->udata = kev11.udata; 1435 bzero(&kevp->ext, sizeof(kevp->ext)); 1436 uap->changelist++; 1437 kevp++; 1438 } 1439 return (error); 1440 } 1441 1442 int 1443 freebsd11_kevent(struct thread *td, struct freebsd11_kevent_args *uap) 1444 { 1445 struct kevent_copyops k_ops = { 1446 .arg = uap, 1447 .k_copyout = kevent11_copyout, 1448 .k_copyin = kevent11_copyin, 1449 .kevent_size = sizeof(struct freebsd11_kevent), 1450 }; 1451 struct g_kevent_args gk_args = { 1452 .fd = uap->fd, 1453 .changelist = uap->changelist, 1454 .nchanges = uap->nchanges, 1455 .eventlist = uap->eventlist, 1456 .nevents = uap->nevents, 1457 .timeout = uap->timeout, 1458 }; 1459 1460 return (kern_kevent_generic(td, &gk_args, &k_ops, "freebsd11_kevent")); 1461 } 1462 #endif 1463 1464 int 1465 kern_kevent(struct thread *td, int fd, int nchanges, int nevents, 1466 struct kevent_copyops *k_ops, const struct timespec *timeout) 1467 { 1468 cap_rights_t rights; 1469 struct file *fp; 1470 int error; 1471 1472 cap_rights_init_zero(&rights); 1473 if (nchanges > 0) 1474 cap_rights_set_one(&rights, CAP_KQUEUE_CHANGE); 1475 if (nevents > 0) 1476 cap_rights_set_one(&rights, CAP_KQUEUE_EVENT); 1477 error = fget(td, fd, &rights, &fp); 1478 if (error != 0) 1479 return (error); 1480 1481 error = kern_kevent_fp(td, fp, nchanges, nevents, k_ops, timeout); 1482 fdrop(fp, td); 1483 1484 return (error); 1485 } 1486 1487 static int 1488 kqueue_kevent(struct kqueue *kq, struct thread *td, int nchanges, int nevents, 1489 struct kevent_copyops *k_ops, const struct timespec *timeout) 1490 { 1491 struct kevent keva[KQ_NEVENTS]; 1492 struct kevent *kevp, *changes; 1493 int i, n, nerrors, error; 1494 1495 if (nchanges < 0) 1496 return (EINVAL); 1497 1498 nerrors = 0; 1499 while (nchanges > 0) { 1500 n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges; 1501 error = k_ops->k_copyin(k_ops->arg, keva, n); 1502 if (error) 1503 return (error); 1504 changes = keva; 1505 for (i = 0; i < n; i++) { 1506 kevp = &changes[i]; 1507 if (!kevp->filter) 1508 continue; 1509 kevp->flags &= ~EV_SYSFLAGS; 1510 error = kqueue_register(kq, kevp, td, M_WAITOK); 1511 if (error || (kevp->flags & EV_RECEIPT)) { 1512 if (nevents == 0) 1513 return (error); 1514 kevp->flags = EV_ERROR; 1515 kevp->data = error; 1516 (void)k_ops->k_copyout(k_ops->arg, kevp, 1); 1517 nevents--; 1518 nerrors++; 1519 } 1520 } 1521 nchanges -= n; 1522 } 1523 if (nerrors) { 1524 td->td_retval[0] = nerrors; 1525 return (0); 1526 } 1527 1528 return (kqueue_scan(kq, nevents, k_ops, timeout, keva, td)); 1529 } 1530 1531 int 1532 kern_kevent_fp(struct thread *td, struct file *fp, int nchanges, int nevents, 1533 struct kevent_copyops *k_ops, const struct timespec *timeout) 1534 { 1535 struct kqueue *kq; 1536 int error; 1537 1538 error = kqueue_acquire(fp, &kq); 1539 if (error != 0) 1540 return (error); 1541 error = kqueue_kevent(kq, td, nchanges, nevents, k_ops, timeout); 1542 kqueue_release(kq, 0); 1543 return (error); 1544 } 1545 1546 /* 1547 * Performs a kevent() call on a temporarily created kqueue. This can be 1548 * used to perform one-shot polling, similar to poll() and select(). 1549 */ 1550 int 1551 kern_kevent_anonymous(struct thread *td, int nevents, 1552 struct kevent_copyops *k_ops) 1553 { 1554 struct kqueue kq = {}; 1555 int error; 1556 1557 kqueue_init(&kq, false); 1558 kq.kq_refcnt = 1; 1559 error = kqueue_kevent(&kq, td, nevents, nevents, k_ops, NULL); 1560 kqueue_drain(&kq, td); 1561 kqueue_destroy(&kq); 1562 return (error); 1563 } 1564 1565 int 1566 kqueue_add_filteropts(int filt, const struct filterops *filtops) 1567 { 1568 int error; 1569 1570 error = 0; 1571 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) { 1572 printf( 1573 "trying to add a filterop that is out of range: %d is beyond %d\n", 1574 ~filt, EVFILT_SYSCOUNT); 1575 return EINVAL; 1576 } 1577 mtx_lock(&filterops_lock); 1578 if (sysfilt_ops[~filt].for_fop != &null_filtops && 1579 sysfilt_ops[~filt].for_fop != NULL) 1580 error = EEXIST; 1581 else { 1582 sysfilt_ops[~filt].for_fop = filtops; 1583 sysfilt_ops[~filt].for_refcnt = 0; 1584 } 1585 mtx_unlock(&filterops_lock); 1586 1587 return (error); 1588 } 1589 1590 int 1591 kqueue_del_filteropts(int filt) 1592 { 1593 int error; 1594 1595 error = 0; 1596 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1597 return EINVAL; 1598 1599 mtx_lock(&filterops_lock); 1600 if (sysfilt_ops[~filt].for_fop == &null_filtops || 1601 sysfilt_ops[~filt].for_fop == NULL) 1602 error = EINVAL; 1603 else if (sysfilt_ops[~filt].for_refcnt != 0) 1604 error = EBUSY; 1605 else { 1606 sysfilt_ops[~filt].for_fop = &null_filtops; 1607 sysfilt_ops[~filt].for_refcnt = 0; 1608 } 1609 mtx_unlock(&filterops_lock); 1610 1611 return error; 1612 } 1613 1614 static const struct filterops * 1615 kqueue_fo_find(int filt) 1616 { 1617 1618 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1619 return NULL; 1620 1621 if (sysfilt_ops[~filt].for_nolock) 1622 return sysfilt_ops[~filt].for_fop; 1623 1624 mtx_lock(&filterops_lock); 1625 sysfilt_ops[~filt].for_refcnt++; 1626 if (sysfilt_ops[~filt].for_fop == NULL) 1627 sysfilt_ops[~filt].for_fop = &null_filtops; 1628 mtx_unlock(&filterops_lock); 1629 1630 return sysfilt_ops[~filt].for_fop; 1631 } 1632 1633 static void 1634 kqueue_fo_release(int filt) 1635 { 1636 1637 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1638 return; 1639 1640 if (sysfilt_ops[~filt].for_nolock) 1641 return; 1642 1643 mtx_lock(&filterops_lock); 1644 KASSERT(sysfilt_ops[~filt].for_refcnt > 0, 1645 ("filter object %d refcount not valid on release", filt)); 1646 sysfilt_ops[~filt].for_refcnt--; 1647 mtx_unlock(&filterops_lock); 1648 } 1649 1650 /* 1651 * A ref to kq (obtained via kqueue_acquire) must be held. 1652 */ 1653 static int 1654 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, 1655 int mflag) 1656 { 1657 const struct filterops *fops; 1658 struct file *fp; 1659 struct knote *kn, *tkn; 1660 struct knlist *knl; 1661 int error, filt, event; 1662 int haskqglobal, filedesc_unlock; 1663 1664 if ((kev->flags & (EV_ENABLE | EV_DISABLE)) == (EV_ENABLE | EV_DISABLE)) 1665 return (EINVAL); 1666 1667 fp = NULL; 1668 kn = NULL; 1669 knl = NULL; 1670 error = 0; 1671 haskqglobal = 0; 1672 filedesc_unlock = 0; 1673 1674 filt = kev->filter; 1675 fops = kqueue_fo_find(filt); 1676 if (fops == NULL) 1677 return EINVAL; 1678 1679 if (kev->flags & EV_ADD) { 1680 /* Reject an invalid flag pair early */ 1681 if (kev->flags & EV_KEEPUDATA) { 1682 tkn = NULL; 1683 error = EINVAL; 1684 goto done; 1685 } 1686 1687 /* 1688 * Prevent waiting with locks. Non-sleepable 1689 * allocation failures are handled in the loop, only 1690 * if the spare knote appears to be actually required. 1691 */ 1692 tkn = knote_alloc(mflag); 1693 } else { 1694 tkn = NULL; 1695 } 1696 1697 findkn: 1698 if (fops->f_isfd) { 1699 KASSERT(td != NULL, ("td is NULL")); 1700 if (kev->ident > INT_MAX) 1701 error = EBADF; 1702 else 1703 error = fget(td, kev->ident, &cap_event_rights, &fp); 1704 if (error) 1705 goto done; 1706 1707 if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops, 1708 kev->ident, M_NOWAIT) != 0) { 1709 /* try again */ 1710 fdrop(fp, td); 1711 fp = NULL; 1712 error = kqueue_expand(kq, fops, kev->ident, mflag); 1713 if (error) 1714 goto done; 1715 goto findkn; 1716 } 1717 1718 if (fp->f_type == DTYPE_KQUEUE) { 1719 /* 1720 * If we add some intelligence about what we are doing, 1721 * we should be able to support events on ourselves. 1722 * We need to know when we are doing this to prevent 1723 * getting both the knlist lock and the kq lock since 1724 * they are the same thing. 1725 */ 1726 if (fp->f_data == kq) { 1727 error = EINVAL; 1728 goto done; 1729 } 1730 1731 /* 1732 * Pre-lock the filedesc before the global 1733 * lock mutex, see the comment in 1734 * kqueue_close(). 1735 */ 1736 FILEDESC_XLOCK(td->td_proc->p_fd); 1737 filedesc_unlock = 1; 1738 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1739 } 1740 1741 KQ_LOCK(kq); 1742 if (kev->ident < kq->kq_knlistsize) { 1743 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link) 1744 if (kev->filter == kn->kn_filter) 1745 break; 1746 } 1747 } else { 1748 if ((kev->flags & EV_ADD) == EV_ADD) { 1749 error = kqueue_expand(kq, fops, kev->ident, mflag); 1750 if (error != 0) 1751 goto done; 1752 } 1753 1754 KQ_LOCK(kq); 1755 1756 /* 1757 * If possible, find an existing knote to use for this kevent. 1758 */ 1759 if (kev->filter == EVFILT_PROC && 1760 (kev->flags & (EV_FLAG1 | EV_FLAG2)) != 0) { 1761 /* This is an internal creation of a process tracking 1762 * note. Don't attempt to coalesce this with an 1763 * existing note. 1764 */ 1765 ; 1766 } else if (kq->kq_knhashmask != 0) { 1767 struct klist *list; 1768 1769 list = &kq->kq_knhash[ 1770 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)]; 1771 SLIST_FOREACH(kn, list, kn_link) 1772 if (kev->ident == kn->kn_id && 1773 kev->filter == kn->kn_filter) 1774 break; 1775 } 1776 } 1777 1778 /* knote is in the process of changing, wait for it to stabilize. */ 1779 if (kn != NULL && kn_in_flux(kn)) { 1780 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1781 if (filedesc_unlock) { 1782 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1783 filedesc_unlock = 0; 1784 } 1785 kq->kq_state |= KQ_FLUXWAIT; 1786 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0); 1787 if (fp != NULL) { 1788 fdrop(fp, td); 1789 fp = NULL; 1790 } 1791 goto findkn; 1792 } 1793 1794 /* 1795 * kn now contains the matching knote, or NULL if no match 1796 */ 1797 if (kn == NULL) { 1798 if (kev->flags & EV_ADD) { 1799 kn = tkn; 1800 tkn = NULL; 1801 if (kn == NULL) { 1802 KQ_UNLOCK(kq); 1803 error = ENOMEM; 1804 goto done; 1805 } 1806 kn->kn_fp = fp; 1807 kn->kn_kq = kq; 1808 kn->kn_fop = fops; 1809 /* 1810 * apply reference counts to knote structure, and 1811 * do not release it at the end of this routine. 1812 */ 1813 fops = NULL; 1814 fp = NULL; 1815 1816 kn->kn_sfflags = kev->fflags; 1817 kn->kn_sdata = kev->data; 1818 kev->fflags = 0; 1819 kev->data = 0; 1820 kn->kn_kevent = *kev; 1821 kn->kn_kevent.flags &= ~(EV_ADD | EV_DELETE | 1822 EV_ENABLE | EV_DISABLE | EV_FORCEONESHOT); 1823 kn->kn_status = KN_DETACHED; 1824 if ((kev->flags & EV_DISABLE) != 0) 1825 kn->kn_status |= KN_DISABLED; 1826 kn_enter_flux(kn); 1827 1828 error = knote_attach(kn, kq); 1829 KQ_UNLOCK(kq); 1830 if (error != 0) { 1831 tkn = kn; 1832 goto done; 1833 } 1834 1835 if ((error = kn->kn_fop->f_attach(kn)) != 0) { 1836 knote_drop_detached(kn, td); 1837 goto done; 1838 } 1839 knl = kn_list_lock(kn); 1840 goto done_ev_add; 1841 } else { 1842 /* No matching knote and the EV_ADD flag is not set. */ 1843 KQ_UNLOCK(kq); 1844 error = ENOENT; 1845 goto done; 1846 } 1847 } 1848 1849 if (kev->flags & EV_DELETE) { 1850 kn_enter_flux(kn); 1851 KQ_UNLOCK(kq); 1852 knote_drop(kn, td); 1853 goto done; 1854 } 1855 1856 if (kev->flags & EV_FORCEONESHOT) { 1857 kn->kn_flags |= EV_ONESHOT; 1858 KNOTE_ACTIVATE(kn, 1); 1859 } 1860 1861 if ((kev->flags & EV_ENABLE) != 0) 1862 kn->kn_status &= ~KN_DISABLED; 1863 else if ((kev->flags & EV_DISABLE) != 0) 1864 kn->kn_status |= KN_DISABLED; 1865 1866 /* 1867 * The user may change some filter values after the initial EV_ADD, 1868 * but doing so will not reset any filter which has already been 1869 * triggered. 1870 */ 1871 kn->kn_status |= KN_SCAN; 1872 kn_enter_flux(kn); 1873 KQ_UNLOCK(kq); 1874 knl = kn_list_lock(kn); 1875 if ((kev->flags & EV_KEEPUDATA) == 0) 1876 kn->kn_kevent.udata = kev->udata; 1877 if (!fops->f_isfd && fops->f_touch != NULL) { 1878 fops->f_touch(kn, kev, EVENT_REGISTER); 1879 } else { 1880 kn->kn_sfflags = kev->fflags; 1881 kn->kn_sdata = kev->data; 1882 } 1883 1884 done_ev_add: 1885 /* 1886 * We can get here with kn->kn_knlist == NULL. This can happen when 1887 * the initial attach event decides that the event is "completed" 1888 * already, e.g., filt_procattach() is called on a zombie process. It 1889 * will call filt_proc() which will remove it from the list, and NULL 1890 * kn_knlist. 1891 * 1892 * KN_DISABLED will be stable while the knote is in flux, so the 1893 * unlocked read will not race with an update. 1894 */ 1895 if ((kn->kn_status & KN_DISABLED) == 0) 1896 event = kn->kn_fop->f_event(kn, 0); 1897 else 1898 event = 0; 1899 1900 KQ_LOCK(kq); 1901 if (event) 1902 kn->kn_status |= KN_ACTIVE; 1903 if ((kn->kn_status & (KN_ACTIVE | KN_DISABLED | KN_QUEUED)) == 1904 KN_ACTIVE) 1905 knote_enqueue(kn); 1906 kn->kn_status &= ~KN_SCAN; 1907 kn_leave_flux(kn); 1908 kn_list_unlock(knl); 1909 KQ_UNLOCK_FLUX(kq); 1910 1911 done: 1912 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1913 if (filedesc_unlock) 1914 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1915 if (fp != NULL) 1916 fdrop(fp, td); 1917 knote_free(tkn); 1918 if (fops != NULL) 1919 kqueue_fo_release(filt); 1920 return (error); 1921 } 1922 1923 static int 1924 kqueue_acquire_ref(struct kqueue *kq) 1925 { 1926 KQ_LOCK(kq); 1927 if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) { 1928 KQ_UNLOCK(kq); 1929 return (EBADF); 1930 } 1931 kq->kq_refcnt++; 1932 KQ_UNLOCK(kq); 1933 return (0); 1934 } 1935 1936 static int 1937 kqueue_acquire(struct file *fp, struct kqueue **kqp) 1938 { 1939 struct kqueue *kq; 1940 int error; 1941 1942 kq = fp->f_data; 1943 if (fp->f_type != DTYPE_KQUEUE || kq == NULL) 1944 return (EINVAL); 1945 error = kqueue_acquire_ref(kq); 1946 if (error == 0) 1947 *kqp = kq; 1948 return (error); 1949 } 1950 1951 static void 1952 kqueue_release(struct kqueue *kq, int locked) 1953 { 1954 if (locked) 1955 KQ_OWNED(kq); 1956 else 1957 KQ_LOCK(kq); 1958 kq->kq_refcnt--; 1959 if (kq->kq_refcnt == 1) 1960 wakeup(&kq->kq_refcnt); 1961 if (!locked) 1962 KQ_UNLOCK(kq); 1963 } 1964 1965 static void 1966 ast_kqueue(struct thread *td, int tda __unused) 1967 { 1968 taskqueue_quiesce(taskqueue_kqueue_ctx); 1969 } 1970 1971 static void 1972 kqueue_schedtask(struct kqueue *kq) 1973 { 1974 KQ_OWNED(kq); 1975 KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN), 1976 ("scheduling kqueue task while draining")); 1977 1978 if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) { 1979 taskqueue_enqueue(taskqueue_kqueue_ctx, &kq->kq_task); 1980 kq->kq_state |= KQ_TASKSCHED; 1981 ast_sched(curthread, TDA_KQUEUE); 1982 } 1983 } 1984 1985 /* 1986 * Expand the kq to make sure we have storage for fops/ident pair. 1987 * 1988 * Return 0 on success (or no work necessary), return errno on failure. 1989 */ 1990 static int 1991 kqueue_expand(struct kqueue *kq, const struct filterops *fops, uintptr_t ident, 1992 int mflag) 1993 { 1994 struct klist *list, *tmp_knhash, *to_free; 1995 u_long tmp_knhashmask; 1996 int error, fd, size; 1997 1998 KQ_NOTOWNED(kq); 1999 2000 error = 0; 2001 to_free = NULL; 2002 if (fops->f_isfd) { 2003 fd = ident; 2004 if (kq->kq_knlistsize <= fd) { 2005 size = kq->kq_knlistsize; 2006 while (size <= fd) 2007 size += KQEXTENT; 2008 list = malloc(size * sizeof(*list), M_KQUEUE, mflag); 2009 if (list == NULL) 2010 return ENOMEM; 2011 KQ_LOCK(kq); 2012 if ((kq->kq_state & KQ_CLOSING) != 0) { 2013 to_free = list; 2014 error = EBADF; 2015 } else if (kq->kq_knlistsize > fd) { 2016 to_free = list; 2017 } else { 2018 if (kq->kq_knlist != NULL) { 2019 bcopy(kq->kq_knlist, list, 2020 kq->kq_knlistsize * sizeof(*list)); 2021 to_free = kq->kq_knlist; 2022 kq->kq_knlist = NULL; 2023 } 2024 bzero((caddr_t)list + 2025 kq->kq_knlistsize * sizeof(*list), 2026 (size - kq->kq_knlistsize) * sizeof(*list)); 2027 kq->kq_knlistsize = size; 2028 kq->kq_knlist = list; 2029 } 2030 KQ_UNLOCK(kq); 2031 } 2032 } else { 2033 if (kq->kq_knhashmask == 0) { 2034 tmp_knhash = hashinit_flags(KN_HASHSIZE, M_KQUEUE, 2035 &tmp_knhashmask, (mflag & M_WAITOK) != 0 ? 2036 HASH_WAITOK : HASH_NOWAIT); 2037 if (tmp_knhash == NULL) 2038 return (ENOMEM); 2039 KQ_LOCK(kq); 2040 if ((kq->kq_state & KQ_CLOSING) != 0) { 2041 to_free = tmp_knhash; 2042 error = EBADF; 2043 } else if (kq->kq_knhashmask == 0) { 2044 kq->kq_knhash = tmp_knhash; 2045 kq->kq_knhashmask = tmp_knhashmask; 2046 } else { 2047 to_free = tmp_knhash; 2048 } 2049 KQ_UNLOCK(kq); 2050 } 2051 } 2052 free(to_free, M_KQUEUE); 2053 2054 KQ_NOTOWNED(kq); 2055 return (error); 2056 } 2057 2058 static void 2059 kqueue_task(void *arg, int pending) 2060 { 2061 struct kqueue *kq; 2062 int haskqglobal; 2063 2064 haskqglobal = 0; 2065 kq = arg; 2066 2067 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 2068 KQ_LOCK(kq); 2069 2070 KNOTE_LOCKED(&kq->kq_sel.si_note, 0); 2071 2072 kq->kq_state &= ~KQ_TASKSCHED; 2073 if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) { 2074 wakeup(&kq->kq_state); 2075 } 2076 KQ_UNLOCK(kq); 2077 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 2078 } 2079 2080 /* 2081 * Scan, update kn_data (if not ONESHOT), and copyout triggered events. 2082 * We treat KN_MARKER knotes as if they are in flux. 2083 */ 2084 static int 2085 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops, 2086 const struct timespec *tsp, struct kevent *keva, struct thread *td) 2087 { 2088 struct kevent *kevp; 2089 struct knote *kn, *marker; 2090 struct knlist *knl; 2091 sbintime_t asbt, rsbt; 2092 int count, error, haskqglobal, influx, nkev, touch; 2093 2094 count = maxevents; 2095 nkev = 0; 2096 error = 0; 2097 haskqglobal = 0; 2098 2099 if (maxevents == 0) 2100 goto done_nl; 2101 if (maxevents < 0) { 2102 error = EINVAL; 2103 goto done_nl; 2104 } 2105 2106 rsbt = 0; 2107 if (tsp != NULL) { 2108 if (!timespecvalid_interval(tsp)) { 2109 error = EINVAL; 2110 goto done_nl; 2111 } 2112 if (timespecisset(tsp)) { 2113 if (tsp->tv_sec <= INT32_MAX) { 2114 rsbt = tstosbt(*tsp); 2115 if (TIMESEL(&asbt, rsbt)) 2116 asbt += tc_tick_sbt; 2117 if (asbt <= SBT_MAX - rsbt) 2118 asbt += rsbt; 2119 else 2120 asbt = 0; 2121 rsbt >>= tc_precexp; 2122 } else 2123 asbt = 0; 2124 } else 2125 asbt = -1; 2126 } else 2127 asbt = 0; 2128 marker = knote_alloc(M_WAITOK); 2129 marker->kn_status = KN_MARKER; 2130 KQ_LOCK(kq); 2131 2132 retry: 2133 kevp = keva; 2134 if (kq->kq_count == 0) { 2135 if (asbt == -1) { 2136 error = EWOULDBLOCK; 2137 } else { 2138 kq->kq_state |= KQ_SLEEP; 2139 error = msleep_sbt(kq, &kq->kq_lock, PSOCK | PCATCH, 2140 "kqread", asbt, rsbt, C_ABSOLUTE); 2141 } 2142 if (error == 0) 2143 goto retry; 2144 /* don't restart after signals... */ 2145 if (error == ERESTART) 2146 error = EINTR; 2147 else if (error == EWOULDBLOCK) 2148 error = 0; 2149 goto done; 2150 } 2151 2152 TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); 2153 influx = 0; 2154 while (count) { 2155 KQ_OWNED(kq); 2156 kn = TAILQ_FIRST(&kq->kq_head); 2157 2158 if ((kn->kn_status == KN_MARKER && kn != marker) || 2159 kn_in_flux(kn)) { 2160 if (influx) { 2161 influx = 0; 2162 KQ_FLUX_WAKEUP(kq); 2163 } 2164 kq->kq_state |= KQ_FLUXWAIT; 2165 error = msleep(kq, &kq->kq_lock, PSOCK, 2166 "kqflxwt", 0); 2167 continue; 2168 } 2169 2170 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 2171 if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) { 2172 kn->kn_status &= ~KN_QUEUED; 2173 kq->kq_count--; 2174 continue; 2175 } 2176 if (kn == marker) { 2177 KQ_FLUX_WAKEUP(kq); 2178 if (count == maxevents) 2179 goto retry; 2180 goto done; 2181 } 2182 KASSERT(!kn_in_flux(kn), 2183 ("knote %p is unexpectedly in flux", kn)); 2184 2185 if ((kn->kn_flags & EV_DROP) == EV_DROP) { 2186 kn->kn_status &= ~KN_QUEUED; 2187 kn_enter_flux(kn); 2188 kq->kq_count--; 2189 KQ_UNLOCK(kq); 2190 /* 2191 * We don't need to lock the list since we've 2192 * marked it as in flux. 2193 */ 2194 knote_drop(kn, td); 2195 KQ_LOCK(kq); 2196 continue; 2197 } else if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) { 2198 kn->kn_status &= ~KN_QUEUED; 2199 kn_enter_flux(kn); 2200 kq->kq_count--; 2201 KQ_UNLOCK(kq); 2202 /* 2203 * We don't need to lock the list since we've 2204 * marked the knote as being in flux. 2205 */ 2206 *kevp = kn->kn_kevent; 2207 knote_drop(kn, td); 2208 KQ_LOCK(kq); 2209 kn = NULL; 2210 } else { 2211 kn->kn_status |= KN_SCAN; 2212 kn_enter_flux(kn); 2213 KQ_UNLOCK(kq); 2214 if ((kn->kn_status & KN_KQUEUE) == KN_KQUEUE) 2215 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 2216 knl = kn_list_lock(kn); 2217 if (kn->kn_fop->f_event(kn, 0) == 0) { 2218 KQ_LOCK(kq); 2219 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 2220 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE | 2221 KN_SCAN); 2222 kn_leave_flux(kn); 2223 kq->kq_count--; 2224 kn_list_unlock(knl); 2225 influx = 1; 2226 continue; 2227 } 2228 touch = (!kn->kn_fop->f_isfd && 2229 kn->kn_fop->f_touch != NULL); 2230 if (touch) 2231 kn->kn_fop->f_touch(kn, kevp, EVENT_PROCESS); 2232 else 2233 *kevp = kn->kn_kevent; 2234 KQ_LOCK(kq); 2235 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 2236 if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) { 2237 /* 2238 * Manually clear knotes who weren't 2239 * 'touch'ed. 2240 */ 2241 if (touch == 0 && kn->kn_flags & EV_CLEAR) { 2242 kn->kn_data = 0; 2243 kn->kn_fflags = 0; 2244 } 2245 if (kn->kn_flags & EV_DISPATCH) 2246 kn->kn_status |= KN_DISABLED; 2247 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 2248 kq->kq_count--; 2249 } else 2250 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2251 2252 kn->kn_status &= ~KN_SCAN; 2253 kn_leave_flux(kn); 2254 kn_list_unlock(knl); 2255 influx = 1; 2256 } 2257 2258 /* we are returning a copy to the user */ 2259 kevp++; 2260 nkev++; 2261 count--; 2262 2263 if (nkev == KQ_NEVENTS) { 2264 influx = 0; 2265 KQ_UNLOCK_FLUX(kq); 2266 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 2267 nkev = 0; 2268 kevp = keva; 2269 KQ_LOCK(kq); 2270 if (error) 2271 break; 2272 } 2273 } 2274 TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); 2275 done: 2276 KQ_OWNED(kq); 2277 KQ_UNLOCK_FLUX(kq); 2278 knote_free(marker); 2279 done_nl: 2280 KQ_NOTOWNED(kq); 2281 if (nkev != 0) 2282 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 2283 td->td_retval[0] = maxevents - count; 2284 return (error); 2285 } 2286 2287 /*ARGSUSED*/ 2288 static int 2289 kqueue_ioctl(struct file *fp, u_long cmd, void *data, 2290 struct ucred *active_cred, struct thread *td) 2291 { 2292 /* 2293 * Enabling sigio causes two major problems: 2294 * 1) infinite recursion: 2295 * Synopsys: kevent is being used to track signals and have FIOASYNC 2296 * set. On receipt of a signal this will cause a kqueue to recurse 2297 * into itself over and over. Sending the sigio causes the kqueue 2298 * to become ready, which in turn posts sigio again, forever. 2299 * Solution: this can be solved by setting a flag in the kqueue that 2300 * we have a SIGIO in progress. 2301 * 2) locking problems: 2302 * Synopsys: Kqueue is a leaf subsystem, but adding signalling puts 2303 * us above the proc and pgrp locks. 2304 * Solution: Post a signal using an async mechanism, being sure to 2305 * record a generation count in the delivery so that we do not deliver 2306 * a signal to the wrong process. 2307 * 2308 * Note, these two mechanisms are somewhat mutually exclusive! 2309 */ 2310 #if 0 2311 struct kqueue *kq; 2312 2313 kq = fp->f_data; 2314 switch (cmd) { 2315 case FIOASYNC: 2316 if (*(int *)data) { 2317 kq->kq_state |= KQ_ASYNC; 2318 } else { 2319 kq->kq_state &= ~KQ_ASYNC; 2320 } 2321 return (0); 2322 2323 case FIOSETOWN: 2324 return (fsetown(*(int *)data, &kq->kq_sigio)); 2325 2326 case FIOGETOWN: 2327 *(int *)data = fgetown(&kq->kq_sigio); 2328 return (0); 2329 } 2330 #endif 2331 2332 return (ENOTTY); 2333 } 2334 2335 /*ARGSUSED*/ 2336 static int 2337 kqueue_poll(struct file *fp, int events, struct ucred *active_cred, 2338 struct thread *td) 2339 { 2340 struct kqueue *kq; 2341 int revents = 0; 2342 int error; 2343 2344 if ((error = kqueue_acquire(fp, &kq))) 2345 return POLLERR; 2346 2347 KQ_LOCK(kq); 2348 if (events & (POLLIN | POLLRDNORM)) { 2349 if (kq->kq_count) { 2350 revents |= events & (POLLIN | POLLRDNORM); 2351 } else { 2352 selrecord(td, &kq->kq_sel); 2353 if (SEL_WAITING(&kq->kq_sel)) 2354 kq->kq_state |= KQ_SEL; 2355 } 2356 } 2357 kqueue_release(kq, 1); 2358 KQ_UNLOCK(kq); 2359 return (revents); 2360 } 2361 2362 /*ARGSUSED*/ 2363 static int 2364 kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred) 2365 { 2366 2367 bzero((void *)st, sizeof *st); 2368 /* 2369 * We no longer return kq_count because the unlocked value is useless. 2370 * If you spent all this time getting the count, why not spend your 2371 * syscall better by calling kevent? 2372 * 2373 * XXX - This is needed for libc_r. 2374 */ 2375 st->st_mode = S_IFIFO; 2376 return (0); 2377 } 2378 2379 static void 2380 kqueue_drain(struct kqueue *kq, struct thread *td) 2381 { 2382 struct knote *kn; 2383 int i; 2384 2385 KQ_LOCK(kq); 2386 2387 KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING, 2388 ("kqueue already closing")); 2389 kq->kq_state |= KQ_CLOSING; 2390 if (kq->kq_refcnt > 1) 2391 msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0); 2392 2393 KASSERT(kq->kq_refcnt == 1, ("other refs are out there!")); 2394 2395 KASSERT(knlist_empty(&kq->kq_sel.si_note), 2396 ("kqueue's knlist not empty")); 2397 2398 for (i = 0; i < kq->kq_knlistsize; i++) { 2399 while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) { 2400 if (kn_in_flux(kn)) { 2401 kq->kq_state |= KQ_FLUXWAIT; 2402 msleep(kq, &kq->kq_lock, PSOCK, "kqclo1", 0); 2403 continue; 2404 } 2405 kn_enter_flux(kn); 2406 KQ_UNLOCK(kq); 2407 knote_drop(kn, td); 2408 KQ_LOCK(kq); 2409 } 2410 } 2411 if (kq->kq_knhashmask != 0) { 2412 for (i = 0; i <= kq->kq_knhashmask; i++) { 2413 while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) { 2414 if (kn_in_flux(kn)) { 2415 kq->kq_state |= KQ_FLUXWAIT; 2416 msleep(kq, &kq->kq_lock, PSOCK, 2417 "kqclo2", 0); 2418 continue; 2419 } 2420 kn_enter_flux(kn); 2421 KQ_UNLOCK(kq); 2422 knote_drop(kn, td); 2423 KQ_LOCK(kq); 2424 } 2425 } 2426 } 2427 2428 if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) { 2429 kq->kq_state |= KQ_TASKDRAIN; 2430 msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0); 2431 } 2432 2433 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2434 selwakeuppri(&kq->kq_sel, PSOCK); 2435 if (!SEL_WAITING(&kq->kq_sel)) 2436 kq->kq_state &= ~KQ_SEL; 2437 } 2438 2439 KQ_UNLOCK(kq); 2440 } 2441 2442 static void 2443 kqueue_destroy(struct kqueue *kq) 2444 { 2445 2446 KASSERT(kq->kq_fdp == NULL, 2447 ("kqueue still attached to a file descriptor")); 2448 seldrain(&kq->kq_sel); 2449 knlist_destroy(&kq->kq_sel.si_note); 2450 mtx_destroy(&kq->kq_lock); 2451 2452 if (kq->kq_knhash != NULL) 2453 free(kq->kq_knhash, M_KQUEUE); 2454 if (kq->kq_knlist != NULL) 2455 free(kq->kq_knlist, M_KQUEUE); 2456 2457 funsetown(&kq->kq_sigio); 2458 } 2459 2460 /*ARGSUSED*/ 2461 static int 2462 kqueue_close(struct file *fp, struct thread *td) 2463 { 2464 struct kqueue *kq = fp->f_data; 2465 struct filedesc *fdp; 2466 int error; 2467 int filedesc_unlock; 2468 2469 if ((error = kqueue_acquire(fp, &kq))) 2470 return error; 2471 kqueue_drain(kq, td); 2472 2473 /* 2474 * We could be called due to the knote_drop() doing fdrop(), 2475 * called from kqueue_register(). In this case the global 2476 * lock is owned, and filedesc sx is locked before, to not 2477 * take the sleepable lock after non-sleepable. 2478 */ 2479 fdp = kq->kq_fdp; 2480 kq->kq_fdp = NULL; 2481 if (!sx_xlocked(FILEDESC_LOCK(fdp))) { 2482 FILEDESC_XLOCK(fdp); 2483 filedesc_unlock = 1; 2484 } else 2485 filedesc_unlock = 0; 2486 TAILQ_REMOVE(&fdp->fd_kqlist, kq, kq_list); 2487 if (filedesc_unlock) 2488 FILEDESC_XUNLOCK(fdp); 2489 2490 kqueue_destroy(kq); 2491 chgkqcnt(kq->kq_cred->cr_ruidinfo, -1, 0); 2492 crfree(kq->kq_cred); 2493 free(kq, M_KQUEUE); 2494 fp->f_data = NULL; 2495 2496 return (0); 2497 } 2498 2499 static int 2500 kqueue_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 2501 { 2502 struct kqueue *kq = fp->f_data; 2503 2504 kif->kf_type = KF_TYPE_KQUEUE; 2505 kif->kf_un.kf_kqueue.kf_kqueue_addr = (uintptr_t)kq; 2506 kif->kf_un.kf_kqueue.kf_kqueue_count = kq->kq_count; 2507 kif->kf_un.kf_kqueue.kf_kqueue_state = kq->kq_state; 2508 return (0); 2509 } 2510 2511 static void 2512 kqueue_wakeup(struct kqueue *kq) 2513 { 2514 KQ_OWNED(kq); 2515 2516 if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) { 2517 kq->kq_state &= ~KQ_SLEEP; 2518 wakeup(kq); 2519 } 2520 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2521 selwakeuppri(&kq->kq_sel, PSOCK); 2522 if (!SEL_WAITING(&kq->kq_sel)) 2523 kq->kq_state &= ~KQ_SEL; 2524 } 2525 if (!knlist_empty(&kq->kq_sel.si_note)) 2526 kqueue_schedtask(kq); 2527 if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) { 2528 pgsigio(&kq->kq_sigio, SIGIO, 0); 2529 } 2530 } 2531 2532 /* 2533 * Walk down a list of knotes, activating them if their event has triggered. 2534 * 2535 * There is a possibility to optimize in the case of one kq watching another. 2536 * Instead of scheduling a task to wake it up, you could pass enough state 2537 * down the chain to make up the parent kqueue. Make this code functional 2538 * first. 2539 */ 2540 void 2541 knote(struct knlist *list, long hint, int lockflags) 2542 { 2543 struct kqueue *kq; 2544 struct knote *kn, *tkn; 2545 int error; 2546 2547 if (list == NULL) 2548 return; 2549 2550 KNL_ASSERT_LOCK(list, lockflags & KNF_LISTLOCKED); 2551 2552 if ((lockflags & KNF_LISTLOCKED) == 0) 2553 list->kl_lock(list->kl_lockarg); 2554 2555 /* 2556 * If we unlock the list lock (and enter influx), we can 2557 * eliminate the kqueue scheduling, but this will introduce 2558 * four lock/unlock's for each knote to test. Also, marker 2559 * would be needed to keep iteration position, since filters 2560 * or other threads could remove events. 2561 */ 2562 SLIST_FOREACH_SAFE(kn, &list->kl_list, kn_selnext, tkn) { 2563 kq = kn->kn_kq; 2564 KQ_LOCK(kq); 2565 if (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0) { 2566 /* 2567 * Do not process the influx notes, except for 2568 * the influx coming from the kq unlock in the 2569 * kqueue_scan(). In the later case, we do 2570 * not interfere with the scan, since the code 2571 * fragment in kqueue_scan() locks the knlist, 2572 * and cannot proceed until we finished. 2573 */ 2574 KQ_UNLOCK(kq); 2575 } else if ((lockflags & KNF_NOKQLOCK) != 0) { 2576 kn_enter_flux(kn); 2577 KQ_UNLOCK(kq); 2578 error = kn->kn_fop->f_event(kn, hint); 2579 KQ_LOCK(kq); 2580 kn_leave_flux(kn); 2581 if (error) 2582 KNOTE_ACTIVATE(kn, 1); 2583 KQ_UNLOCK_FLUX(kq); 2584 } else { 2585 if (kn->kn_fop->f_event(kn, hint)) 2586 KNOTE_ACTIVATE(kn, 1); 2587 KQ_UNLOCK(kq); 2588 } 2589 } 2590 if ((lockflags & KNF_LISTLOCKED) == 0) 2591 list->kl_unlock(list->kl_lockarg); 2592 } 2593 2594 /* 2595 * add a knote to a knlist 2596 */ 2597 void 2598 knlist_add(struct knlist *knl, struct knote *kn, int islocked) 2599 { 2600 2601 KNL_ASSERT_LOCK(knl, islocked); 2602 KQ_NOTOWNED(kn->kn_kq); 2603 KASSERT(kn_in_flux(kn), ("knote %p not in flux", kn)); 2604 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2605 ("knote %p was not detached", kn)); 2606 if (!islocked) 2607 knl->kl_lock(knl->kl_lockarg); 2608 SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext); 2609 if (!islocked) 2610 knl->kl_unlock(knl->kl_lockarg); 2611 KQ_LOCK(kn->kn_kq); 2612 kn->kn_knlist = knl; 2613 kn->kn_status &= ~KN_DETACHED; 2614 KQ_UNLOCK(kn->kn_kq); 2615 } 2616 2617 static void 2618 knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked, 2619 int kqislocked) 2620 { 2621 2622 KASSERT(!kqislocked || knlislocked, ("kq locked w/o knl locked")); 2623 KNL_ASSERT_LOCK(knl, knlislocked); 2624 mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED); 2625 KASSERT(kqislocked || kn_in_flux(kn), ("knote %p not in flux", kn)); 2626 KASSERT((kn->kn_status & KN_DETACHED) == 0, 2627 ("knote %p was already detached", kn)); 2628 if (!knlislocked) 2629 knl->kl_lock(knl->kl_lockarg); 2630 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext); 2631 kn->kn_knlist = NULL; 2632 if (!knlislocked) 2633 kn_list_unlock(knl); 2634 if (!kqislocked) 2635 KQ_LOCK(kn->kn_kq); 2636 kn->kn_status |= KN_DETACHED; 2637 if (!kqislocked) 2638 KQ_UNLOCK(kn->kn_kq); 2639 } 2640 2641 /* 2642 * remove knote from the specified knlist 2643 */ 2644 void 2645 knlist_remove(struct knlist *knl, struct knote *kn, int islocked) 2646 { 2647 2648 knlist_remove_kq(knl, kn, islocked, 0); 2649 } 2650 2651 int 2652 knlist_empty(struct knlist *knl) 2653 { 2654 2655 KNL_ASSERT_LOCKED(knl); 2656 return (SLIST_EMPTY(&knl->kl_list)); 2657 } 2658 2659 static struct mtx knlist_lock; 2660 MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects", 2661 MTX_DEF); 2662 static void knlist_mtx_lock(void *arg); 2663 static void knlist_mtx_unlock(void *arg); 2664 2665 static void 2666 knlist_mtx_lock(void *arg) 2667 { 2668 2669 mtx_lock((struct mtx *)arg); 2670 } 2671 2672 static void 2673 knlist_mtx_unlock(void *arg) 2674 { 2675 2676 mtx_unlock((struct mtx *)arg); 2677 } 2678 2679 static void 2680 knlist_mtx_assert_lock(void *arg, int what) 2681 { 2682 2683 if (what == LA_LOCKED) 2684 mtx_assert((struct mtx *)arg, MA_OWNED); 2685 else 2686 mtx_assert((struct mtx *)arg, MA_NOTOWNED); 2687 } 2688 2689 void 2690 knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *), 2691 void (*kl_unlock)(void *), 2692 void (*kl_assert_lock)(void *, int)) 2693 { 2694 2695 if (lock == NULL) 2696 knl->kl_lockarg = &knlist_lock; 2697 else 2698 knl->kl_lockarg = lock; 2699 2700 if (kl_lock == NULL) 2701 knl->kl_lock = knlist_mtx_lock; 2702 else 2703 knl->kl_lock = kl_lock; 2704 if (kl_unlock == NULL) 2705 knl->kl_unlock = knlist_mtx_unlock; 2706 else 2707 knl->kl_unlock = kl_unlock; 2708 if (kl_assert_lock == NULL) 2709 knl->kl_assert_lock = knlist_mtx_assert_lock; 2710 else 2711 knl->kl_assert_lock = kl_assert_lock; 2712 2713 knl->kl_autodestroy = 0; 2714 SLIST_INIT(&knl->kl_list); 2715 } 2716 2717 void 2718 knlist_init_mtx(struct knlist *knl, struct mtx *lock) 2719 { 2720 2721 knlist_init(knl, lock, NULL, NULL, NULL); 2722 } 2723 2724 struct knlist * 2725 knlist_alloc(struct mtx *lock) 2726 { 2727 struct knlist *knl; 2728 2729 knl = malloc(sizeof(struct knlist), M_KQUEUE, M_WAITOK); 2730 knlist_init_mtx(knl, lock); 2731 return (knl); 2732 } 2733 2734 void 2735 knlist_destroy(struct knlist *knl) 2736 { 2737 2738 KASSERT(KNLIST_EMPTY(knl), 2739 ("destroying knlist %p with knotes on it", knl)); 2740 } 2741 2742 void 2743 knlist_detach(struct knlist *knl) 2744 { 2745 2746 KNL_ASSERT_LOCKED(knl); 2747 knl->kl_autodestroy = 1; 2748 if (knlist_empty(knl)) { 2749 knlist_destroy(knl); 2750 free(knl, M_KQUEUE); 2751 } 2752 } 2753 2754 /* 2755 * Even if we are locked, we may need to drop the lock to allow any influx 2756 * knotes time to "settle". 2757 */ 2758 void 2759 knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn) 2760 { 2761 struct knote *kn, *kn2; 2762 struct kqueue *kq; 2763 2764 KASSERT(!knl->kl_autodestroy, ("cleardel for autodestroy %p", knl)); 2765 if (islocked) 2766 KNL_ASSERT_LOCKED(knl); 2767 else { 2768 KNL_ASSERT_UNLOCKED(knl); 2769 again: /* need to reacquire lock since we have dropped it */ 2770 knl->kl_lock(knl->kl_lockarg); 2771 } 2772 2773 SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) { 2774 kq = kn->kn_kq; 2775 KQ_LOCK(kq); 2776 if (kn_in_flux(kn)) { 2777 KQ_UNLOCK(kq); 2778 continue; 2779 } 2780 knlist_remove_kq(knl, kn, 1, 1); 2781 if (killkn) { 2782 kn_enter_flux(kn); 2783 KQ_UNLOCK(kq); 2784 knote_drop_detached(kn, td); 2785 } else { 2786 /* Make sure cleared knotes disappear soon */ 2787 kn->kn_flags |= EV_EOF | EV_ONESHOT; 2788 KQ_UNLOCK(kq); 2789 } 2790 kq = NULL; 2791 } 2792 2793 if (!SLIST_EMPTY(&knl->kl_list)) { 2794 /* there are still in flux knotes remaining */ 2795 kn = SLIST_FIRST(&knl->kl_list); 2796 kq = kn->kn_kq; 2797 KQ_LOCK(kq); 2798 KASSERT(kn_in_flux(kn), ("knote removed w/o list lock")); 2799 knl->kl_unlock(knl->kl_lockarg); 2800 kq->kq_state |= KQ_FLUXWAIT; 2801 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0); 2802 kq = NULL; 2803 goto again; 2804 } 2805 2806 if (islocked) 2807 KNL_ASSERT_LOCKED(knl); 2808 else { 2809 knl->kl_unlock(knl->kl_lockarg); 2810 KNL_ASSERT_UNLOCKED(knl); 2811 } 2812 } 2813 2814 /* 2815 * Remove all knotes referencing a specified fd must be called with FILEDESC 2816 * lock. This prevents a race where a new fd comes along and occupies the 2817 * entry and we attach a knote to the fd. 2818 */ 2819 void 2820 knote_fdclose(struct thread *td, int fd) 2821 { 2822 struct filedesc *fdp = td->td_proc->p_fd; 2823 struct kqueue *kq; 2824 struct knote *kn; 2825 int influx; 2826 2827 FILEDESC_XLOCK_ASSERT(fdp); 2828 2829 /* 2830 * We shouldn't have to worry about new kevents appearing on fd 2831 * since filedesc is locked. 2832 */ 2833 TAILQ_FOREACH(kq, &fdp->fd_kqlist, kq_list) { 2834 KQ_LOCK(kq); 2835 2836 again: 2837 influx = 0; 2838 while (kq->kq_knlistsize > fd && 2839 (kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) { 2840 if (kn_in_flux(kn)) { 2841 /* someone else might be waiting on our knote */ 2842 if (influx) 2843 wakeup(kq); 2844 kq->kq_state |= KQ_FLUXWAIT; 2845 msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0); 2846 goto again; 2847 } 2848 kn_enter_flux(kn); 2849 KQ_UNLOCK(kq); 2850 influx = 1; 2851 knote_drop(kn, td); 2852 KQ_LOCK(kq); 2853 } 2854 KQ_UNLOCK_FLUX(kq); 2855 } 2856 } 2857 2858 static int 2859 knote_attach(struct knote *kn, struct kqueue *kq) 2860 { 2861 struct klist *list; 2862 2863 KASSERT(kn_in_flux(kn), ("knote %p not marked influx", kn)); 2864 KQ_OWNED(kq); 2865 2866 if ((kq->kq_state & KQ_CLOSING) != 0) 2867 return (EBADF); 2868 if (kn->kn_fop->f_isfd) { 2869 if (kn->kn_id >= kq->kq_knlistsize) 2870 return (ENOMEM); 2871 list = &kq->kq_knlist[kn->kn_id]; 2872 } else { 2873 if (kq->kq_knhash == NULL) 2874 return (ENOMEM); 2875 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2876 } 2877 SLIST_INSERT_HEAD(list, kn, kn_link); 2878 return (0); 2879 } 2880 2881 static void 2882 knote_drop(struct knote *kn, struct thread *td) 2883 { 2884 2885 if ((kn->kn_status & KN_DETACHED) == 0) 2886 kn->kn_fop->f_detach(kn); 2887 knote_drop_detached(kn, td); 2888 } 2889 2890 static void 2891 knote_drop_detached(struct knote *kn, struct thread *td) 2892 { 2893 struct kqueue *kq; 2894 struct klist *list; 2895 2896 kq = kn->kn_kq; 2897 2898 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2899 ("knote %p still attached", kn)); 2900 KQ_NOTOWNED(kq); 2901 2902 KQ_LOCK(kq); 2903 for (;;) { 2904 KASSERT(kn->kn_influx >= 1, 2905 ("knote_drop called on %p with influx %d", 2906 kn, kn->kn_influx)); 2907 if (kn->kn_influx == 1) 2908 break; 2909 kq->kq_state |= KQ_FLUXWAIT; 2910 msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0); 2911 } 2912 2913 if (kn->kn_fop->f_isfd) 2914 list = &kq->kq_knlist[kn->kn_id]; 2915 else 2916 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2917 2918 if (!SLIST_EMPTY(list)) 2919 SLIST_REMOVE(list, kn, knote, kn_link); 2920 if (kn->kn_status & KN_QUEUED) 2921 knote_dequeue(kn); 2922 KQ_UNLOCK_FLUX(kq); 2923 2924 if (kn->kn_fop->f_isfd) { 2925 fdrop(kn->kn_fp, td); 2926 kn->kn_fp = NULL; 2927 } 2928 kqueue_fo_release(kn->kn_kevent.filter); 2929 kn->kn_fop = NULL; 2930 knote_free(kn); 2931 } 2932 2933 static void 2934 knote_enqueue(struct knote *kn) 2935 { 2936 struct kqueue *kq = kn->kn_kq; 2937 2938 KQ_OWNED(kn->kn_kq); 2939 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 2940 2941 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2942 kn->kn_status |= KN_QUEUED; 2943 kq->kq_count++; 2944 kqueue_wakeup(kq); 2945 } 2946 2947 static void 2948 knote_dequeue(struct knote *kn) 2949 { 2950 struct kqueue *kq = kn->kn_kq; 2951 2952 KQ_OWNED(kn->kn_kq); 2953 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 2954 2955 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 2956 kn->kn_status &= ~KN_QUEUED; 2957 kq->kq_count--; 2958 } 2959 2960 static void 2961 knote_init(void *dummy __unused) 2962 { 2963 2964 knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL, 2965 NULL, NULL, UMA_ALIGN_PTR, 0); 2966 ast_register(TDA_KQUEUE, ASTR_ASTF_REQUIRED, 0, ast_kqueue); 2967 prison0.pr_klist = knlist_alloc(&prison0.pr_mtx); 2968 } 2969 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL); 2970 2971 static struct knote * 2972 knote_alloc(int mflag) 2973 { 2974 2975 return (uma_zalloc(knote_zone, mflag | M_ZERO)); 2976 } 2977 2978 static void 2979 knote_free(struct knote *kn) 2980 { 2981 2982 uma_zfree(knote_zone, kn); 2983 } 2984 2985 /* 2986 * Register the kev w/ the kq specified by fd. 2987 */ 2988 int 2989 kqfd_register(int fd, struct kevent *kev, struct thread *td, int mflag) 2990 { 2991 struct kqueue *kq; 2992 struct file *fp; 2993 cap_rights_t rights; 2994 int error; 2995 2996 error = fget(td, fd, cap_rights_init_one(&rights, CAP_KQUEUE_CHANGE), 2997 &fp); 2998 if (error != 0) 2999 return (error); 3000 if ((error = kqueue_acquire(fp, &kq)) != 0) 3001 goto noacquire; 3002 3003 error = kqueue_register(kq, kev, td, mflag); 3004 kqueue_release(kq, 0); 3005 3006 noacquire: 3007 fdrop(fp, td); 3008 return (error); 3009 } 3010 3011 static int 3012 kqueue_fork_alloc(struct filedesc *fdp, struct file *fp, struct file **fp1, 3013 struct thread *td) 3014 { 3015 struct kqueue *kq, *kq1; 3016 int error; 3017 3018 MPASS(fp->f_type == DTYPE_KQUEUE); 3019 kq = fp->f_data; 3020 if ((kq->kq_state & KQ_CPONFORK) == 0) 3021 return (EOPNOTSUPP); 3022 error = kqueue_acquire_ref(kq); 3023 if (error != 0) 3024 return (error); 3025 error = kern_kqueue_alloc(td, fdp, NULL, fp1, 0, NULL, true, &kq1); 3026 if (error == 0) { 3027 kq1->kq_forksrc = kq; 3028 (*fp1)->f_flag = fp->f_flag & (FREAD | FWRITE | FEXEC | 3029 O_CLOEXEC | O_CLOFORK); 3030 } else { 3031 kqueue_release(kq, 0); 3032 } 3033 return (error); 3034 } 3035 3036 static void 3037 kqueue_fork_copy_knote(struct kqueue *kq1, struct knote *kn, struct proc *p1, 3038 struct filedesc *fdp) 3039 { 3040 struct knote *kn1; 3041 const struct filterops *fop; 3042 int error; 3043 3044 fop = kn->kn_fop; 3045 if (fop->f_copy == NULL || (fop->f_isfd && 3046 fdp->fd_files->fdt_ofiles[kn->kn_kevent.ident].fde_file == NULL)) 3047 return; 3048 error = kqueue_expand(kq1, fop, kn->kn_kevent.ident, M_WAITOK); 3049 if (error != 0) 3050 return; 3051 3052 kn1 = knote_alloc(M_WAITOK); 3053 *kn1 = *kn; 3054 kn1->kn_status |= KN_DETACHED; 3055 kn1->kn_status &= ~KN_QUEUED; 3056 kn1->kn_kq = kq1; 3057 error = fop->f_copy(kn1, p1); 3058 if (error != 0) { 3059 knote_free(kn1); 3060 return; 3061 } 3062 (void)kqueue_fo_find(kn->kn_kevent.filter); 3063 if (fop->f_isfd && !fhold(kn1->kn_fp)) { 3064 fop->f_detach(kn1); 3065 kqueue_fo_release(kn->kn_kevent.filter); 3066 knote_free(kn1); 3067 return; 3068 } 3069 if (kn->kn_knlist != NULL) 3070 knlist_add(kn->kn_knlist, kn1, 0); 3071 KQ_LOCK(kq1); 3072 knote_attach(kn1, kq1); 3073 kn1->kn_influx = 0; 3074 if ((kn->kn_status & KN_QUEUED) != 0) 3075 knote_enqueue(kn1); 3076 KQ_UNLOCK(kq1); 3077 } 3078 3079 static void 3080 kqueue_fork_copy_list(struct klist *knlist, struct knote *marker, 3081 struct kqueue *kq, struct kqueue *kq1, struct proc *p1, 3082 struct filedesc *fdp) 3083 { 3084 struct knote *kn; 3085 3086 KQ_OWNED(kq); 3087 kn = SLIST_FIRST(knlist); 3088 while (kn != NULL) { 3089 if ((kn->kn_status & KN_DETACHED) != 0 || 3090 (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0)) { 3091 kn = SLIST_NEXT(kn, kn_link); 3092 continue; 3093 } 3094 kn_enter_flux(kn); 3095 SLIST_INSERT_AFTER(kn, marker, kn_link); 3096 KQ_UNLOCK(kq); 3097 kqueue_fork_copy_knote(kq1, kn, p1, fdp); 3098 KQ_LOCK(kq); 3099 kn_leave_flux(kn); 3100 kn = SLIST_NEXT(marker, kn_link); 3101 /* XXXKIB switch kn_link to LIST? */ 3102 SLIST_REMOVE(knlist, marker, knote, kn_link); 3103 } 3104 } 3105 3106 static int 3107 kqueue_fork_copy(struct filedesc *fdp, struct file *fp, struct file *fp1, 3108 struct proc *p1, struct thread *td) 3109 { 3110 struct kqueue *kq, *kq1; 3111 struct knote *marker; 3112 int error, i; 3113 3114 error = 0; 3115 MPASS(fp == NULL); 3116 MPASS(fp1->f_type == DTYPE_KQUEUE); 3117 3118 kq1 = fp1->f_data; 3119 kq = kq1->kq_forksrc; 3120 marker = knote_alloc(M_WAITOK); 3121 marker->kn_status = KN_MARKER; 3122 3123 KQ_LOCK(kq); 3124 for (i = 0; i < kq->kq_knlistsize; i++) { 3125 kqueue_fork_copy_list(&kq->kq_knlist[i], marker, kq, kq1, 3126 p1, fdp); 3127 } 3128 if (kq->kq_knhashmask != 0) { 3129 for (i = 0; i <= kq->kq_knhashmask; i++) { 3130 kqueue_fork_copy_list(&kq->kq_knhash[i], marker, kq, 3131 kq1, p1, fdp); 3132 } 3133 } 3134 kqueue_release(kq, 1); 3135 kq1->kq_forksrc = NULL; 3136 KQ_UNLOCK(kq); 3137 3138 knote_free(marker); 3139 return (error); 3140 } 3141 3142 static int 3143 kqueue_fork(struct filedesc *fdp, struct file *fp, struct file **fp1, 3144 struct proc *p1, struct thread *td) 3145 { 3146 if (*fp1 == NULL) 3147 return (kqueue_fork_alloc(fdp, fp, fp1, td)); 3148 return (kqueue_fork_copy(fdp, fp, *fp1, p1, td)); 3149 } 3150 3151 int 3152 knote_triv_copy(struct knote *kn __unused, struct proc *p1 __unused) 3153 { 3154 return (0); 3155 } 3156 3157 struct knote_status_export_bit { 3158 int kn_status_bit; 3159 int knt_status_bit; 3160 }; 3161 3162 #define ST(name) \ 3163 { .kn_status_bit = KN_##name, .knt_status_bit = KNOTE_STATUS_##name } 3164 static const struct knote_status_export_bit knote_status_export_bits[] = { 3165 ST(ACTIVE), 3166 ST(QUEUED), 3167 ST(DISABLED), 3168 ST(DETACHED), 3169 ST(KQUEUE), 3170 }; 3171 #undef ST 3172 3173 static int 3174 knote_status_export(int kn_status) 3175 { 3176 const struct knote_status_export_bit *b; 3177 unsigned i; 3178 int res; 3179 3180 res = 0; 3181 for (i = 0; i < nitems(knote_status_export_bits); i++) { 3182 b = &knote_status_export_bits[i]; 3183 if ((kn_status & b->kn_status_bit) != 0) 3184 res |= b->knt_status_bit; 3185 } 3186 return (res); 3187 } 3188 3189 static int 3190 kern_proc_kqueue_report_one(struct sbuf *s, struct proc *p, 3191 int kq_fd, struct kqueue *kq, struct knote *kn, bool compat32 __unused) 3192 { 3193 struct kinfo_knote kin; 3194 #ifdef COMPAT_FREEBSD32 3195 struct kinfo_knote32 kin32; 3196 #endif 3197 int error; 3198 3199 if (kn->kn_status == KN_MARKER) 3200 return (0); 3201 3202 memset(&kin, 0, sizeof(kin)); 3203 kin.knt_kq_fd = kq_fd; 3204 memcpy(&kin.knt_event, &kn->kn_kevent, sizeof(struct kevent)); 3205 kin.knt_status = knote_status_export(kn->kn_status); 3206 kn_enter_flux(kn); 3207 KQ_UNLOCK_FLUX(kq); 3208 if (kn->kn_fop->f_userdump != NULL) 3209 (void)kn->kn_fop->f_userdump(p, kn, &kin); 3210 #ifdef COMPAT_FREEBSD32 3211 if (compat32) { 3212 freebsd32_kinfo_knote_to_32(&kin, &kin32); 3213 error = sbuf_bcat(s, &kin32, sizeof(kin32)); 3214 } else 3215 #endif 3216 error = sbuf_bcat(s, &kin, sizeof(kin)); 3217 KQ_LOCK(kq); 3218 kn_leave_flux(kn); 3219 return (error); 3220 } 3221 3222 static int 3223 kern_proc_kqueue_report(struct sbuf *s, struct proc *p, int kq_fd, 3224 struct kqueue *kq, bool compat32) 3225 { 3226 struct knote *kn; 3227 int error, i; 3228 3229 error = 0; 3230 KQ_LOCK(kq); 3231 for (i = 0; i < kq->kq_knlistsize; i++) { 3232 SLIST_FOREACH(kn, &kq->kq_knlist[i], kn_link) { 3233 error = kern_proc_kqueue_report_one(s, p, kq_fd, 3234 kq, kn, compat32); 3235 if (error != 0) 3236 goto out; 3237 } 3238 } 3239 if (kq->kq_knhashmask == 0) 3240 goto out; 3241 for (i = 0; i <= kq->kq_knhashmask; i++) { 3242 SLIST_FOREACH(kn, &kq->kq_knhash[i], kn_link) { 3243 error = kern_proc_kqueue_report_one(s, p, kq_fd, 3244 kq, kn, compat32); 3245 if (error != 0) 3246 goto out; 3247 } 3248 } 3249 out: 3250 KQ_UNLOCK_FLUX(kq); 3251 return (error); 3252 } 3253 3254 struct kern_proc_kqueues_out1_cb_args { 3255 struct sbuf *s; 3256 bool compat32; 3257 }; 3258 3259 static int 3260 kern_proc_kqueues_out1_cb(struct proc *p, int fd, struct file *fp, void *arg) 3261 { 3262 struct kqueue *kq; 3263 struct kern_proc_kqueues_out1_cb_args *a; 3264 3265 if (fp->f_type != DTYPE_KQUEUE) 3266 return (0); 3267 a = arg; 3268 kq = fp->f_data; 3269 return (kern_proc_kqueue_report(a->s, p, fd, kq, a->compat32)); 3270 } 3271 3272 static int 3273 kern_proc_kqueues_out1(struct thread *td, struct proc *p, struct sbuf *s, 3274 bool compat32) 3275 { 3276 struct kern_proc_kqueues_out1_cb_args a; 3277 3278 a.s = s; 3279 a.compat32 = compat32; 3280 return (fget_remote_foreach(td, p, kern_proc_kqueues_out1_cb, &a)); 3281 } 3282 3283 int 3284 kern_proc_kqueues_out(struct proc *p, struct sbuf *sb, size_t maxlen, 3285 bool compat32) 3286 { 3287 struct sbuf *s, sm; 3288 size_t sb_len; 3289 int error; 3290 3291 if (maxlen == -1 || maxlen == 0) 3292 sb_len = 128; 3293 else 3294 sb_len = maxlen; 3295 s = sbuf_new(&sm, NULL, sb_len, maxlen == -1 ? SBUF_AUTOEXTEND : 3296 SBUF_FIXEDLEN); 3297 error = kern_proc_kqueues_out1(curthread, p, s, compat32); 3298 sbuf_finish(s); 3299 if (error == 0) { 3300 sbuf_bcat(sb, sbuf_data(s), MIN(sbuf_len(s), maxlen == -1 ? 3301 SIZE_T_MAX : maxlen)); 3302 } 3303 sbuf_delete(s); 3304 return (error); 3305 } 3306 3307 static int 3308 sysctl_kern_proc_kqueue_one(struct thread *td, struct sbuf *s, struct proc *p, 3309 int kq_fd, bool compat32) 3310 { 3311 struct file *fp; 3312 struct kqueue *kq; 3313 int error; 3314 3315 error = fget_remote(td, p, kq_fd, &fp); 3316 if (error == 0) { 3317 if (fp->f_type != DTYPE_KQUEUE) { 3318 error = EINVAL; 3319 } else { 3320 kq = fp->f_data; 3321 error = kern_proc_kqueue_report(s, p, kq_fd, kq, 3322 compat32); 3323 } 3324 fdrop(fp, td); 3325 } 3326 return (error); 3327 } 3328 3329 static int 3330 sysctl_kern_proc_kqueue(SYSCTL_HANDLER_ARGS) 3331 { 3332 struct thread *td; 3333 struct proc *p; 3334 struct sbuf *s, sm; 3335 int error, error1, *name; 3336 bool compat32; 3337 3338 name = (int *)arg1; 3339 if ((u_int)arg2 > 2 || (u_int)arg2 == 0) 3340 return (EINVAL); 3341 3342 error = pget((pid_t)name[0], PGET_HOLD | PGET_CANDEBUG, &p); 3343 if (error != 0) 3344 return (error); 3345 3346 td = curthread; 3347 #ifdef COMPAT_FREEBSD32 3348 compat32 = SV_CURPROC_FLAG(SV_ILP32); 3349 #else 3350 compat32 = false; 3351 #endif 3352 3353 s = sbuf_new_for_sysctl(&sm, NULL, 0, req); 3354 if (s == NULL) { 3355 error = ENOMEM; 3356 goto out; 3357 } 3358 sbuf_clear_flags(s, SBUF_INCLUDENUL); 3359 3360 if ((u_int)arg2 == 1) { 3361 error = kern_proc_kqueues_out1(td, p, s, compat32); 3362 } else { 3363 error = sysctl_kern_proc_kqueue_one(td, s, p, 3364 name[1] /* kq_fd */, compat32); 3365 } 3366 3367 error1 = sbuf_finish(s); 3368 if (error == 0) 3369 error = error1; 3370 sbuf_delete(s); 3371 3372 out: 3373 PRELE(p); 3374 return (error); 3375 } 3376 3377 static SYSCTL_NODE(_kern_proc, KERN_PROC_KQUEUE, kq, 3378 CTLFLAG_RD | CTLFLAG_MPSAFE, 3379 sysctl_kern_proc_kqueue, "KQueue events"); 3380