1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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 __FBSDID("$FreeBSD$"); 33 34 #include "opt_ktrace.h" 35 #include "opt_kqueue.h" 36 37 #ifdef COMPAT_FREEBSD11 38 #define _WANT_FREEBSD11_KEVENT 39 #endif 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/capsicum.h> 44 #include <sys/kernel.h> 45 #include <sys/lock.h> 46 #include <sys/mutex.h> 47 #include <sys/rwlock.h> 48 #include <sys/proc.h> 49 #include <sys/malloc.h> 50 #include <sys/unistd.h> 51 #include <sys/file.h> 52 #include <sys/filedesc.h> 53 #include <sys/filio.h> 54 #include <sys/fcntl.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/sigio.h> 64 #include <sys/signalvar.h> 65 #include <sys/socket.h> 66 #include <sys/socketvar.h> 67 #include <sys/stat.h> 68 #include <sys/sysctl.h> 69 #include <sys/sysproto.h> 70 #include <sys/syscallsubr.h> 71 #include <sys/taskqueue.h> 72 #include <sys/uio.h> 73 #include <sys/user.h> 74 #ifdef KTRACE 75 #include <sys/ktrace.h> 76 #endif 77 #include <machine/atomic.h> 78 79 #include <vm/uma.h> 80 81 static MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system"); 82 83 /* 84 * This lock is used if multiple kq locks are required. This possibly 85 * should be made into a per proc lock. 86 */ 87 static struct mtx kq_global; 88 MTX_SYSINIT(kq_global, &kq_global, "kqueue order", MTX_DEF); 89 #define KQ_GLOBAL_LOCK(lck, haslck) do { \ 90 if (!haslck) \ 91 mtx_lock(lck); \ 92 haslck = 1; \ 93 } while (0) 94 #define KQ_GLOBAL_UNLOCK(lck, haslck) do { \ 95 if (haslck) \ 96 mtx_unlock(lck); \ 97 haslck = 0; \ 98 } while (0) 99 100 TASKQUEUE_DEFINE_THREAD(kqueue_ctx); 101 102 static int kevent_copyout(void *arg, struct kevent *kevp, int count); 103 static int kevent_copyin(void *arg, struct kevent *kevp, int count); 104 static int kqueue_register(struct kqueue *kq, struct kevent *kev, 105 struct thread *td, int waitok); 106 static int kqueue_acquire(struct file *fp, struct kqueue **kqp); 107 static void kqueue_release(struct kqueue *kq, int locked); 108 static void kqueue_destroy(struct kqueue *kq); 109 static void kqueue_drain(struct kqueue *kq, struct thread *td); 110 static int kqueue_expand(struct kqueue *kq, struct filterops *fops, 111 uintptr_t ident, int waitok); 112 static void kqueue_task(void *arg, int pending); 113 static int kqueue_scan(struct kqueue *kq, int maxevents, 114 struct kevent_copyops *k_ops, 115 const struct timespec *timeout, 116 struct kevent *keva, struct thread *td); 117 static void kqueue_wakeup(struct kqueue *kq); 118 static struct filterops *kqueue_fo_find(int filt); 119 static void kqueue_fo_release(int filt); 120 struct g_kevent_args; 121 static int kern_kevent_generic(struct thread *td, 122 struct g_kevent_args *uap, 123 struct kevent_copyops *k_ops, const char *struct_name); 124 125 static fo_ioctl_t kqueue_ioctl; 126 static fo_poll_t kqueue_poll; 127 static fo_kqfilter_t kqueue_kqfilter; 128 static fo_stat_t kqueue_stat; 129 static fo_close_t kqueue_close; 130 static fo_fill_kinfo_t kqueue_fill_kinfo; 131 132 static struct fileops kqueueops = { 133 .fo_read = invfo_rdwr, 134 .fo_write = invfo_rdwr, 135 .fo_truncate = invfo_truncate, 136 .fo_ioctl = kqueue_ioctl, 137 .fo_poll = kqueue_poll, 138 .fo_kqfilter = kqueue_kqfilter, 139 .fo_stat = kqueue_stat, 140 .fo_close = kqueue_close, 141 .fo_chmod = invfo_chmod, 142 .fo_chown = invfo_chown, 143 .fo_sendfile = invfo_sendfile, 144 .fo_fill_kinfo = kqueue_fill_kinfo, 145 }; 146 147 static int knote_attach(struct knote *kn, struct kqueue *kq); 148 static void knote_drop(struct knote *kn, struct thread *td); 149 static void knote_drop_detached(struct knote *kn, struct thread *td); 150 static void knote_enqueue(struct knote *kn); 151 static void knote_dequeue(struct knote *kn); 152 static void knote_init(void); 153 static struct knote *knote_alloc(int waitok); 154 static void knote_free(struct knote *kn); 155 156 static void filt_kqdetach(struct knote *kn); 157 static int filt_kqueue(struct knote *kn, long hint); 158 static int filt_procattach(struct knote *kn); 159 static void filt_procdetach(struct knote *kn); 160 static int filt_proc(struct knote *kn, long hint); 161 static int filt_fileattach(struct knote *kn); 162 static void filt_timerexpire(void *knx); 163 static int filt_timerattach(struct knote *kn); 164 static void filt_timerdetach(struct knote *kn); 165 static void filt_timerstart(struct knote *kn, sbintime_t to); 166 static void filt_timertouch(struct knote *kn, struct kevent *kev, 167 u_long type); 168 static int filt_timervalidate(struct knote *kn, sbintime_t *to); 169 static int filt_timer(struct knote *kn, long hint); 170 static int filt_userattach(struct knote *kn); 171 static void filt_userdetach(struct knote *kn); 172 static int filt_user(struct knote *kn, long hint); 173 static void filt_usertouch(struct knote *kn, struct kevent *kev, 174 u_long type); 175 176 static struct filterops file_filtops = { 177 .f_isfd = 1, 178 .f_attach = filt_fileattach, 179 }; 180 static struct filterops kqread_filtops = { 181 .f_isfd = 1, 182 .f_detach = filt_kqdetach, 183 .f_event = filt_kqueue, 184 }; 185 /* XXX - move to kern_proc.c? */ 186 static struct filterops proc_filtops = { 187 .f_isfd = 0, 188 .f_attach = filt_procattach, 189 .f_detach = filt_procdetach, 190 .f_event = filt_proc, 191 }; 192 static struct filterops timer_filtops = { 193 .f_isfd = 0, 194 .f_attach = filt_timerattach, 195 .f_detach = filt_timerdetach, 196 .f_event = filt_timer, 197 .f_touch = filt_timertouch, 198 }; 199 static struct filterops user_filtops = { 200 .f_attach = filt_userattach, 201 .f_detach = filt_userdetach, 202 .f_event = filt_user, 203 .f_touch = filt_usertouch, 204 }; 205 206 static uma_zone_t knote_zone; 207 static unsigned int kq_ncallouts = 0; 208 static unsigned int kq_calloutmax = 4 * 1024; 209 SYSCTL_UINT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW, 210 &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue"); 211 212 /* XXX - ensure not influx ? */ 213 #define KNOTE_ACTIVATE(kn, islock) do { \ 214 if ((islock)) \ 215 mtx_assert(&(kn)->kn_kq->kq_lock, MA_OWNED); \ 216 else \ 217 KQ_LOCK((kn)->kn_kq); \ 218 (kn)->kn_status |= KN_ACTIVE; \ 219 if (((kn)->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 220 knote_enqueue((kn)); \ 221 if (!(islock)) \ 222 KQ_UNLOCK((kn)->kn_kq); \ 223 } while(0) 224 #define KQ_LOCK(kq) do { \ 225 mtx_lock(&(kq)->kq_lock); \ 226 } while (0) 227 #define KQ_FLUX_WAKEUP(kq) do { \ 228 if (((kq)->kq_state & KQ_FLUXWAIT) == KQ_FLUXWAIT) { \ 229 (kq)->kq_state &= ~KQ_FLUXWAIT; \ 230 wakeup((kq)); \ 231 } \ 232 } while (0) 233 #define KQ_UNLOCK_FLUX(kq) do { \ 234 KQ_FLUX_WAKEUP(kq); \ 235 mtx_unlock(&(kq)->kq_lock); \ 236 } while (0) 237 #define KQ_UNLOCK(kq) do { \ 238 mtx_unlock(&(kq)->kq_lock); \ 239 } while (0) 240 #define KQ_OWNED(kq) do { \ 241 mtx_assert(&(kq)->kq_lock, MA_OWNED); \ 242 } while (0) 243 #define KQ_NOTOWNED(kq) do { \ 244 mtx_assert(&(kq)->kq_lock, MA_NOTOWNED); \ 245 } while (0) 246 247 static struct knlist * 248 kn_list_lock(struct knote *kn) 249 { 250 struct knlist *knl; 251 252 knl = kn->kn_knlist; 253 if (knl != NULL) 254 knl->kl_lock(knl->kl_lockarg); 255 return (knl); 256 } 257 258 static void 259 kn_list_unlock(struct knlist *knl) 260 { 261 bool do_free; 262 263 if (knl == NULL) 264 return; 265 do_free = knl->kl_autodestroy && knlist_empty(knl); 266 knl->kl_unlock(knl->kl_lockarg); 267 if (do_free) { 268 knlist_destroy(knl); 269 free(knl, M_KQUEUE); 270 } 271 } 272 273 static bool 274 kn_in_flux(struct knote *kn) 275 { 276 277 return (kn->kn_influx > 0); 278 } 279 280 static void 281 kn_enter_flux(struct knote *kn) 282 { 283 284 KQ_OWNED(kn->kn_kq); 285 MPASS(kn->kn_influx < INT_MAX); 286 kn->kn_influx++; 287 } 288 289 static bool 290 kn_leave_flux(struct knote *kn) 291 { 292 293 KQ_OWNED(kn->kn_kq); 294 MPASS(kn->kn_influx > 0); 295 kn->kn_influx--; 296 return (kn->kn_influx == 0); 297 } 298 299 #define KNL_ASSERT_LOCK(knl, islocked) do { \ 300 if (islocked) \ 301 KNL_ASSERT_LOCKED(knl); \ 302 else \ 303 KNL_ASSERT_UNLOCKED(knl); \ 304 } while (0) 305 #ifdef INVARIANTS 306 #define KNL_ASSERT_LOCKED(knl) do { \ 307 knl->kl_assert_locked((knl)->kl_lockarg); \ 308 } while (0) 309 #define KNL_ASSERT_UNLOCKED(knl) do { \ 310 knl->kl_assert_unlocked((knl)->kl_lockarg); \ 311 } while (0) 312 #else /* !INVARIANTS */ 313 #define KNL_ASSERT_LOCKED(knl) do {} while(0) 314 #define KNL_ASSERT_UNLOCKED(knl) do {} while (0) 315 #endif /* INVARIANTS */ 316 317 #ifndef KN_HASHSIZE 318 #define KN_HASHSIZE 64 /* XXX should be tunable */ 319 #endif 320 321 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 322 323 static int 324 filt_nullattach(struct knote *kn) 325 { 326 327 return (ENXIO); 328 }; 329 330 struct filterops null_filtops = { 331 .f_isfd = 0, 332 .f_attach = filt_nullattach, 333 }; 334 335 /* XXX - make SYSINIT to add these, and move into respective modules. */ 336 extern struct filterops sig_filtops; 337 extern struct filterops fs_filtops; 338 339 /* 340 * Table for for all system-defined filters. 341 */ 342 static struct mtx filterops_lock; 343 MTX_SYSINIT(kqueue_filterops, &filterops_lock, "protect sysfilt_ops", 344 MTX_DEF); 345 static struct { 346 struct filterops *for_fop; 347 int for_nolock; 348 int for_refcnt; 349 } sysfilt_ops[EVFILT_SYSCOUNT] = { 350 { &file_filtops, 1 }, /* EVFILT_READ */ 351 { &file_filtops, 1 }, /* EVFILT_WRITE */ 352 { &null_filtops }, /* EVFILT_AIO */ 353 { &file_filtops, 1 }, /* EVFILT_VNODE */ 354 { &proc_filtops, 1 }, /* EVFILT_PROC */ 355 { &sig_filtops, 1 }, /* EVFILT_SIGNAL */ 356 { &timer_filtops, 1 }, /* EVFILT_TIMER */ 357 { &file_filtops, 1 }, /* EVFILT_PROCDESC */ 358 { &fs_filtops, 1 }, /* EVFILT_FS */ 359 { &null_filtops }, /* EVFILT_LIO */ 360 { &user_filtops, 1 }, /* EVFILT_USER */ 361 { &null_filtops }, /* EVFILT_SENDFILE */ 362 { &file_filtops, 1 }, /* EVFILT_EMPTY */ 363 }; 364 365 /* 366 * Simple redirection for all cdevsw style objects to call their fo_kqfilter 367 * method. 368 */ 369 static int 370 filt_fileattach(struct knote *kn) 371 { 372 373 return (fo_kqfilter(kn->kn_fp, kn)); 374 } 375 376 /*ARGSUSED*/ 377 static int 378 kqueue_kqfilter(struct file *fp, struct knote *kn) 379 { 380 struct kqueue *kq = kn->kn_fp->f_data; 381 382 if (kn->kn_filter != EVFILT_READ) 383 return (EINVAL); 384 385 kn->kn_status |= KN_KQUEUE; 386 kn->kn_fop = &kqread_filtops; 387 knlist_add(&kq->kq_sel.si_note, kn, 0); 388 389 return (0); 390 } 391 392 static void 393 filt_kqdetach(struct knote *kn) 394 { 395 struct kqueue *kq = kn->kn_fp->f_data; 396 397 knlist_remove(&kq->kq_sel.si_note, kn, 0); 398 } 399 400 /*ARGSUSED*/ 401 static int 402 filt_kqueue(struct knote *kn, long hint) 403 { 404 struct kqueue *kq = kn->kn_fp->f_data; 405 406 kn->kn_data = kq->kq_count; 407 return (kn->kn_data > 0); 408 } 409 410 /* XXX - move to kern_proc.c? */ 411 static int 412 filt_procattach(struct knote *kn) 413 { 414 struct proc *p; 415 int error; 416 bool exiting, immediate; 417 418 exiting = immediate = false; 419 if (kn->kn_sfflags & NOTE_EXIT) 420 p = pfind_any(kn->kn_id); 421 else 422 p = pfind(kn->kn_id); 423 if (p == NULL) 424 return (ESRCH); 425 if (p->p_flag & P_WEXIT) 426 exiting = true; 427 428 if ((error = p_cansee(curthread, p))) { 429 PROC_UNLOCK(p); 430 return (error); 431 } 432 433 kn->kn_ptr.p_proc = p; 434 kn->kn_flags |= EV_CLEAR; /* automatically set */ 435 436 /* 437 * Internal flag indicating registration done by kernel for the 438 * purposes of getting a NOTE_CHILD notification. 439 */ 440 if (kn->kn_flags & EV_FLAG2) { 441 kn->kn_flags &= ~EV_FLAG2; 442 kn->kn_data = kn->kn_sdata; /* ppid */ 443 kn->kn_fflags = NOTE_CHILD; 444 kn->kn_sfflags &= ~(NOTE_EXIT | NOTE_EXEC | NOTE_FORK); 445 immediate = true; /* Force immediate activation of child note. */ 446 } 447 /* 448 * Internal flag indicating registration done by kernel (for other than 449 * NOTE_CHILD). 450 */ 451 if (kn->kn_flags & EV_FLAG1) { 452 kn->kn_flags &= ~EV_FLAG1; 453 } 454 455 knlist_add(p->p_klist, kn, 1); 456 457 /* 458 * Immediately activate any child notes or, in the case of a zombie 459 * target process, exit notes. The latter is necessary to handle the 460 * case where the target process, e.g. a child, dies before the kevent 461 * is registered. 462 */ 463 if (immediate || (exiting && filt_proc(kn, NOTE_EXIT))) 464 KNOTE_ACTIVATE(kn, 0); 465 466 PROC_UNLOCK(p); 467 468 return (0); 469 } 470 471 /* 472 * The knote may be attached to a different process, which may exit, 473 * leaving nothing for the knote to be attached to. So when the process 474 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 475 * it will be deleted when read out. However, as part of the knote deletion, 476 * this routine is called, so a check is needed to avoid actually performing 477 * a detach, because the original process does not exist any more. 478 */ 479 /* XXX - move to kern_proc.c? */ 480 static void 481 filt_procdetach(struct knote *kn) 482 { 483 484 knlist_remove(kn->kn_knlist, kn, 0); 485 kn->kn_ptr.p_proc = NULL; 486 } 487 488 /* XXX - move to kern_proc.c? */ 489 static int 490 filt_proc(struct knote *kn, long hint) 491 { 492 struct proc *p; 493 u_int event; 494 495 p = kn->kn_ptr.p_proc; 496 if (p == NULL) /* already activated, from attach filter */ 497 return (0); 498 499 /* Mask off extra data. */ 500 event = (u_int)hint & NOTE_PCTRLMASK; 501 502 /* If the user is interested in this event, record it. */ 503 if (kn->kn_sfflags & event) 504 kn->kn_fflags |= event; 505 506 /* Process is gone, so flag the event as finished. */ 507 if (event == NOTE_EXIT) { 508 kn->kn_flags |= EV_EOF | EV_ONESHOT; 509 kn->kn_ptr.p_proc = NULL; 510 if (kn->kn_fflags & NOTE_EXIT) 511 kn->kn_data = KW_EXITCODE(p->p_xexit, p->p_xsig); 512 if (kn->kn_fflags == 0) 513 kn->kn_flags |= EV_DROP; 514 return (1); 515 } 516 517 return (kn->kn_fflags != 0); 518 } 519 520 /* 521 * Called when the process forked. It mostly does the same as the 522 * knote(), activating all knotes registered to be activated when the 523 * process forked. Additionally, for each knote attached to the 524 * parent, check whether user wants to track the new process. If so 525 * attach a new knote to it, and immediately report an event with the 526 * child's pid. 527 */ 528 void 529 knote_fork(struct knlist *list, int pid) 530 { 531 struct kqueue *kq; 532 struct knote *kn; 533 struct kevent kev; 534 int error; 535 536 if (list == NULL) 537 return; 538 list->kl_lock(list->kl_lockarg); 539 540 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { 541 kq = kn->kn_kq; 542 KQ_LOCK(kq); 543 if (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0) { 544 KQ_UNLOCK(kq); 545 continue; 546 } 547 548 /* 549 * The same as knote(), activate the event. 550 */ 551 if ((kn->kn_sfflags & NOTE_TRACK) == 0) { 552 if (kn->kn_fop->f_event(kn, NOTE_FORK)) 553 KNOTE_ACTIVATE(kn, 1); 554 KQ_UNLOCK(kq); 555 continue; 556 } 557 558 /* 559 * The NOTE_TRACK case. In addition to the activation 560 * of the event, we need to register new events to 561 * track the child. Drop the locks in preparation for 562 * the call to kqueue_register(). 563 */ 564 kn_enter_flux(kn); 565 KQ_UNLOCK(kq); 566 list->kl_unlock(list->kl_lockarg); 567 568 /* 569 * Activate existing knote and register tracking knotes with 570 * new process. 571 * 572 * First register a knote to get just the child notice. This 573 * must be a separate note from a potential NOTE_EXIT 574 * notification since both NOTE_CHILD and NOTE_EXIT are defined 575 * to use the data field (in conflicting ways). 576 */ 577 kev.ident = pid; 578 kev.filter = kn->kn_filter; 579 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_ONESHOT | 580 EV_FLAG2; 581 kev.fflags = kn->kn_sfflags; 582 kev.data = kn->kn_id; /* parent */ 583 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 584 error = kqueue_register(kq, &kev, NULL, 0); 585 if (error) 586 kn->kn_fflags |= NOTE_TRACKERR; 587 588 /* 589 * Then register another knote to track other potential events 590 * from the new process. 591 */ 592 kev.ident = pid; 593 kev.filter = kn->kn_filter; 594 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 595 kev.fflags = kn->kn_sfflags; 596 kev.data = kn->kn_id; /* parent */ 597 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 598 error = kqueue_register(kq, &kev, NULL, 0); 599 if (error) 600 kn->kn_fflags |= NOTE_TRACKERR; 601 if (kn->kn_fop->f_event(kn, NOTE_FORK)) 602 KNOTE_ACTIVATE(kn, 0); 603 list->kl_lock(list->kl_lockarg); 604 KQ_LOCK(kq); 605 kn_leave_flux(kn); 606 KQ_UNLOCK_FLUX(kq); 607 } 608 list->kl_unlock(list->kl_lockarg); 609 } 610 611 /* 612 * XXX: EVFILT_TIMER should perhaps live in kern_time.c beside the 613 * interval timer support code. 614 */ 615 616 #define NOTE_TIMER_PRECMASK \ 617 (NOTE_SECONDS | NOTE_MSECONDS | NOTE_USECONDS | NOTE_NSECONDS) 618 619 static sbintime_t 620 timer2sbintime(intptr_t data, int flags) 621 { 622 int64_t secs; 623 624 /* 625 * Macros for converting to the fractional second portion of an 626 * sbintime_t using 64bit multiplication to improve precision. 627 */ 628 #define NS_TO_SBT(ns) (((ns) * (((uint64_t)1 << 63) / 500000000)) >> 32) 629 #define US_TO_SBT(us) (((us) * (((uint64_t)1 << 63) / 500000)) >> 32) 630 #define MS_TO_SBT(ms) (((ms) * (((uint64_t)1 << 63) / 500)) >> 32) 631 switch (flags & NOTE_TIMER_PRECMASK) { 632 case NOTE_SECONDS: 633 #ifdef __LP64__ 634 if (data > (SBT_MAX / SBT_1S)) 635 return (SBT_MAX); 636 #endif 637 return ((sbintime_t)data << 32); 638 case NOTE_MSECONDS: /* FALLTHROUGH */ 639 case 0: 640 if (data >= 1000) { 641 secs = data / 1000; 642 #ifdef __LP64__ 643 if (secs > (SBT_MAX / SBT_1S)) 644 return (SBT_MAX); 645 #endif 646 return (secs << 32 | MS_TO_SBT(data % 1000)); 647 } 648 return (MS_TO_SBT(data)); 649 case NOTE_USECONDS: 650 if (data >= 1000000) { 651 secs = data / 1000000; 652 #ifdef __LP64__ 653 if (secs > (SBT_MAX / SBT_1S)) 654 return (SBT_MAX); 655 #endif 656 return (secs << 32 | US_TO_SBT(data % 1000000)); 657 } 658 return (US_TO_SBT(data)); 659 case NOTE_NSECONDS: 660 if (data >= 1000000000) { 661 secs = data / 1000000000; 662 #ifdef __LP64__ 663 if (secs > (SBT_MAX / SBT_1S)) 664 return (SBT_MAX); 665 #endif 666 return (secs << 32 | US_TO_SBT(data % 1000000000)); 667 } 668 return (NS_TO_SBT(data)); 669 default: 670 break; 671 } 672 return (-1); 673 } 674 675 struct kq_timer_cb_data { 676 struct callout c; 677 sbintime_t next; /* next timer event fires at */ 678 sbintime_t to; /* precalculated timer period, 0 for abs */ 679 }; 680 681 static void 682 filt_timerexpire(void *knx) 683 { 684 struct knote *kn; 685 struct kq_timer_cb_data *kc; 686 687 kn = knx; 688 kn->kn_data++; 689 KNOTE_ACTIVATE(kn, 0); /* XXX - handle locking */ 690 691 if ((kn->kn_flags & EV_ONESHOT) != 0) 692 return; 693 kc = kn->kn_ptr.p_v; 694 if (kc->to == 0) 695 return; 696 kc->next += kc->to; 697 callout_reset_sbt_on(&kc->c, kc->next, 0, filt_timerexpire, kn, 698 PCPU_GET(cpuid), C_ABSOLUTE); 699 } 700 701 /* 702 * data contains amount of time to sleep 703 */ 704 static int 705 filt_timervalidate(struct knote *kn, sbintime_t *to) 706 { 707 struct bintime bt; 708 sbintime_t sbt; 709 710 if (kn->kn_sdata < 0) 711 return (EINVAL); 712 if (kn->kn_sdata == 0 && (kn->kn_flags & EV_ONESHOT) == 0) 713 kn->kn_sdata = 1; 714 /* 715 * The only fflags values supported are the timer unit 716 * (precision) and the absolute time indicator. 717 */ 718 if ((kn->kn_sfflags & ~(NOTE_TIMER_PRECMASK | NOTE_ABSTIME)) != 0) 719 return (EINVAL); 720 721 *to = timer2sbintime(kn->kn_sdata, kn->kn_sfflags); 722 if ((kn->kn_sfflags & NOTE_ABSTIME) != 0) { 723 getboottimebin(&bt); 724 sbt = bttosbt(bt); 725 *to -= sbt; 726 } 727 if (*to < 0) 728 return (EINVAL); 729 return (0); 730 } 731 732 static int 733 filt_timerattach(struct knote *kn) 734 { 735 struct kq_timer_cb_data *kc; 736 sbintime_t to; 737 unsigned int ncallouts; 738 int error; 739 740 error = filt_timervalidate(kn, &to); 741 if (error != 0) 742 return (error); 743 744 do { 745 ncallouts = kq_ncallouts; 746 if (ncallouts >= kq_calloutmax) 747 return (ENOMEM); 748 } while (!atomic_cmpset_int(&kq_ncallouts, ncallouts, ncallouts + 1)); 749 750 if ((kn->kn_sfflags & NOTE_ABSTIME) == 0) 751 kn->kn_flags |= EV_CLEAR; /* automatically set */ 752 kn->kn_status &= ~KN_DETACHED; /* knlist_add clears it */ 753 kn->kn_ptr.p_v = kc = malloc(sizeof(*kc), M_KQUEUE, M_WAITOK); 754 callout_init(&kc->c, 1); 755 filt_timerstart(kn, to); 756 757 return (0); 758 } 759 760 static void 761 filt_timerstart(struct knote *kn, sbintime_t to) 762 { 763 struct kq_timer_cb_data *kc; 764 765 kc = kn->kn_ptr.p_v; 766 if ((kn->kn_sfflags & NOTE_ABSTIME) != 0) { 767 kc->next = to; 768 kc->to = 0; 769 } else { 770 kc->next = to + sbinuptime(); 771 kc->to = to; 772 } 773 callout_reset_sbt_on(&kc->c, kc->next, 0, filt_timerexpire, kn, 774 PCPU_GET(cpuid), C_ABSOLUTE); 775 } 776 777 static void 778 filt_timerdetach(struct knote *kn) 779 { 780 struct kq_timer_cb_data *kc; 781 unsigned int old __unused; 782 783 kc = kn->kn_ptr.p_v; 784 callout_drain(&kc->c); 785 free(kc, M_KQUEUE); 786 old = atomic_fetchadd_int(&kq_ncallouts, -1); 787 KASSERT(old > 0, ("Number of callouts cannot become negative")); 788 kn->kn_status |= KN_DETACHED; /* knlist_remove sets it */ 789 } 790 791 static void 792 filt_timertouch(struct knote *kn, struct kevent *kev, u_long type) 793 { 794 struct kq_timer_cb_data *kc; 795 struct kqueue *kq; 796 sbintime_t to; 797 int error; 798 799 switch (type) { 800 case EVENT_REGISTER: 801 /* Handle re-added timers that update data/fflags */ 802 if (kev->flags & EV_ADD) { 803 kc = kn->kn_ptr.p_v; 804 805 /* Drain any existing callout. */ 806 callout_drain(&kc->c); 807 808 /* Throw away any existing undelivered record 809 * of the timer expiration. This is done under 810 * the presumption that if a process is 811 * re-adding this timer with new parameters, 812 * it is no longer interested in what may have 813 * happened under the old parameters. If it is 814 * interested, it can wait for the expiration, 815 * delete the old timer definition, and then 816 * add the new one. 817 * 818 * This has to be done while the kq is locked: 819 * - if enqueued, dequeue 820 * - make it no longer active 821 * - clear the count of expiration events 822 */ 823 kq = kn->kn_kq; 824 KQ_LOCK(kq); 825 if (kn->kn_status & KN_QUEUED) 826 knote_dequeue(kn); 827 828 kn->kn_status &= ~KN_ACTIVE; 829 kn->kn_data = 0; 830 KQ_UNLOCK(kq); 831 832 /* Reschedule timer based on new data/fflags */ 833 kn->kn_sfflags = kev->fflags; 834 kn->kn_sdata = kev->data; 835 error = filt_timervalidate(kn, &to); 836 if (error != 0) { 837 kn->kn_flags |= EV_ERROR; 838 kn->kn_data = error; 839 } else 840 filt_timerstart(kn, to); 841 } 842 break; 843 844 case EVENT_PROCESS: 845 *kev = kn->kn_kevent; 846 if (kn->kn_flags & EV_CLEAR) { 847 kn->kn_data = 0; 848 kn->kn_fflags = 0; 849 } 850 break; 851 852 default: 853 panic("filt_timertouch() - invalid type (%ld)", type); 854 break; 855 } 856 } 857 858 static int 859 filt_timer(struct knote *kn, long hint) 860 { 861 862 return (kn->kn_data != 0); 863 } 864 865 static int 866 filt_userattach(struct knote *kn) 867 { 868 869 /* 870 * EVFILT_USER knotes are not attached to anything in the kernel. 871 */ 872 kn->kn_hook = NULL; 873 if (kn->kn_fflags & NOTE_TRIGGER) 874 kn->kn_hookid = 1; 875 else 876 kn->kn_hookid = 0; 877 return (0); 878 } 879 880 static void 881 filt_userdetach(__unused struct knote *kn) 882 { 883 884 /* 885 * EVFILT_USER knotes are not attached to anything in the kernel. 886 */ 887 } 888 889 static int 890 filt_user(struct knote *kn, __unused long hint) 891 { 892 893 return (kn->kn_hookid); 894 } 895 896 static void 897 filt_usertouch(struct knote *kn, struct kevent *kev, u_long type) 898 { 899 u_int ffctrl; 900 901 switch (type) { 902 case EVENT_REGISTER: 903 if (kev->fflags & NOTE_TRIGGER) 904 kn->kn_hookid = 1; 905 906 ffctrl = kev->fflags & NOTE_FFCTRLMASK; 907 kev->fflags &= NOTE_FFLAGSMASK; 908 switch (ffctrl) { 909 case NOTE_FFNOP: 910 break; 911 912 case NOTE_FFAND: 913 kn->kn_sfflags &= kev->fflags; 914 break; 915 916 case NOTE_FFOR: 917 kn->kn_sfflags |= kev->fflags; 918 break; 919 920 case NOTE_FFCOPY: 921 kn->kn_sfflags = kev->fflags; 922 break; 923 924 default: 925 /* XXX Return error? */ 926 break; 927 } 928 kn->kn_sdata = kev->data; 929 if (kev->flags & EV_CLEAR) { 930 kn->kn_hookid = 0; 931 kn->kn_data = 0; 932 kn->kn_fflags = 0; 933 } 934 break; 935 936 case EVENT_PROCESS: 937 *kev = kn->kn_kevent; 938 kev->fflags = kn->kn_sfflags; 939 kev->data = kn->kn_sdata; 940 if (kn->kn_flags & EV_CLEAR) { 941 kn->kn_hookid = 0; 942 kn->kn_data = 0; 943 kn->kn_fflags = 0; 944 } 945 break; 946 947 default: 948 panic("filt_usertouch() - invalid type (%ld)", type); 949 break; 950 } 951 } 952 953 int 954 sys_kqueue(struct thread *td, struct kqueue_args *uap) 955 { 956 957 return (kern_kqueue(td, 0, NULL)); 958 } 959 960 static void 961 kqueue_init(struct kqueue *kq) 962 { 963 964 mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF | MTX_DUPOK); 965 TAILQ_INIT(&kq->kq_head); 966 knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock); 967 TASK_INIT(&kq->kq_task, 0, kqueue_task, kq); 968 } 969 970 int 971 kern_kqueue(struct thread *td, int flags, struct filecaps *fcaps) 972 { 973 struct filedesc *fdp; 974 struct kqueue *kq; 975 struct file *fp; 976 struct ucred *cred; 977 int fd, error; 978 979 fdp = td->td_proc->p_fd; 980 cred = td->td_ucred; 981 if (!chgkqcnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_KQUEUES))) 982 return (ENOMEM); 983 984 error = falloc_caps(td, &fp, &fd, flags, fcaps); 985 if (error != 0) { 986 chgkqcnt(cred->cr_ruidinfo, -1, 0); 987 return (error); 988 } 989 990 /* An extra reference on `fp' has been held for us by falloc(). */ 991 kq = malloc(sizeof *kq, M_KQUEUE, M_WAITOK | M_ZERO); 992 kqueue_init(kq); 993 kq->kq_fdp = fdp; 994 kq->kq_cred = crhold(cred); 995 996 FILEDESC_XLOCK(fdp); 997 TAILQ_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list); 998 FILEDESC_XUNLOCK(fdp); 999 1000 finit(fp, FREAD | FWRITE, DTYPE_KQUEUE, kq, &kqueueops); 1001 fdrop(fp, td); 1002 1003 td->td_retval[0] = fd; 1004 return (0); 1005 } 1006 1007 struct g_kevent_args { 1008 int fd; 1009 void *changelist; 1010 int nchanges; 1011 void *eventlist; 1012 int nevents; 1013 const struct timespec *timeout; 1014 }; 1015 1016 int 1017 sys_kevent(struct thread *td, struct kevent_args *uap) 1018 { 1019 struct kevent_copyops k_ops = { 1020 .arg = uap, 1021 .k_copyout = kevent_copyout, 1022 .k_copyin = kevent_copyin, 1023 .kevent_size = sizeof(struct kevent), 1024 }; 1025 struct g_kevent_args gk_args = { 1026 .fd = uap->fd, 1027 .changelist = uap->changelist, 1028 .nchanges = uap->nchanges, 1029 .eventlist = uap->eventlist, 1030 .nevents = uap->nevents, 1031 .timeout = uap->timeout, 1032 }; 1033 1034 return (kern_kevent_generic(td, &gk_args, &k_ops, "kevent")); 1035 } 1036 1037 static int 1038 kern_kevent_generic(struct thread *td, struct g_kevent_args *uap, 1039 struct kevent_copyops *k_ops, const char *struct_name) 1040 { 1041 struct timespec ts, *tsp; 1042 #ifdef KTRACE 1043 struct kevent *eventlist = uap->eventlist; 1044 #endif 1045 int error; 1046 1047 if (uap->timeout != NULL) { 1048 error = copyin(uap->timeout, &ts, sizeof(ts)); 1049 if (error) 1050 return (error); 1051 tsp = &ts; 1052 } else 1053 tsp = NULL; 1054 1055 #ifdef KTRACE 1056 if (KTRPOINT(td, KTR_STRUCT_ARRAY)) 1057 ktrstructarray(struct_name, UIO_USERSPACE, uap->changelist, 1058 uap->nchanges, k_ops->kevent_size); 1059 #endif 1060 1061 error = kern_kevent(td, uap->fd, uap->nchanges, uap->nevents, 1062 k_ops, tsp); 1063 1064 #ifdef KTRACE 1065 if (error == 0 && KTRPOINT(td, KTR_STRUCT_ARRAY)) 1066 ktrstructarray(struct_name, UIO_USERSPACE, eventlist, 1067 td->td_retval[0], k_ops->kevent_size); 1068 #endif 1069 1070 return (error); 1071 } 1072 1073 /* 1074 * Copy 'count' items into the destination list pointed to by uap->eventlist. 1075 */ 1076 static int 1077 kevent_copyout(void *arg, struct kevent *kevp, int count) 1078 { 1079 struct kevent_args *uap; 1080 int error; 1081 1082 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1083 uap = (struct kevent_args *)arg; 1084 1085 error = copyout(kevp, uap->eventlist, count * sizeof *kevp); 1086 if (error == 0) 1087 uap->eventlist += count; 1088 return (error); 1089 } 1090 1091 /* 1092 * Copy 'count' items from the list pointed to by uap->changelist. 1093 */ 1094 static int 1095 kevent_copyin(void *arg, struct kevent *kevp, int count) 1096 { 1097 struct kevent_args *uap; 1098 int error; 1099 1100 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1101 uap = (struct kevent_args *)arg; 1102 1103 error = copyin(uap->changelist, kevp, count * sizeof *kevp); 1104 if (error == 0) 1105 uap->changelist += count; 1106 return (error); 1107 } 1108 1109 #ifdef COMPAT_FREEBSD11 1110 static int 1111 kevent11_copyout(void *arg, struct kevent *kevp, int count) 1112 { 1113 struct freebsd11_kevent_args *uap; 1114 struct kevent_freebsd11 kev11; 1115 int error, i; 1116 1117 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1118 uap = (struct freebsd11_kevent_args *)arg; 1119 1120 for (i = 0; i < count; i++) { 1121 kev11.ident = kevp->ident; 1122 kev11.filter = kevp->filter; 1123 kev11.flags = kevp->flags; 1124 kev11.fflags = kevp->fflags; 1125 kev11.data = kevp->data; 1126 kev11.udata = kevp->udata; 1127 error = copyout(&kev11, uap->eventlist, sizeof(kev11)); 1128 if (error != 0) 1129 break; 1130 uap->eventlist++; 1131 kevp++; 1132 } 1133 return (error); 1134 } 1135 1136 /* 1137 * Copy 'count' items from the list pointed to by uap->changelist. 1138 */ 1139 static int 1140 kevent11_copyin(void *arg, struct kevent *kevp, int count) 1141 { 1142 struct freebsd11_kevent_args *uap; 1143 struct kevent_freebsd11 kev11; 1144 int error, i; 1145 1146 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1147 uap = (struct freebsd11_kevent_args *)arg; 1148 1149 for (i = 0; i < count; i++) { 1150 error = copyin(uap->changelist, &kev11, sizeof(kev11)); 1151 if (error != 0) 1152 break; 1153 kevp->ident = kev11.ident; 1154 kevp->filter = kev11.filter; 1155 kevp->flags = kev11.flags; 1156 kevp->fflags = kev11.fflags; 1157 kevp->data = (uintptr_t)kev11.data; 1158 kevp->udata = kev11.udata; 1159 bzero(&kevp->ext, sizeof(kevp->ext)); 1160 uap->changelist++; 1161 kevp++; 1162 } 1163 return (error); 1164 } 1165 1166 int 1167 freebsd11_kevent(struct thread *td, struct freebsd11_kevent_args *uap) 1168 { 1169 struct kevent_copyops k_ops = { 1170 .arg = uap, 1171 .k_copyout = kevent11_copyout, 1172 .k_copyin = kevent11_copyin, 1173 .kevent_size = sizeof(struct kevent_freebsd11), 1174 }; 1175 struct g_kevent_args gk_args = { 1176 .fd = uap->fd, 1177 .changelist = uap->changelist, 1178 .nchanges = uap->nchanges, 1179 .eventlist = uap->eventlist, 1180 .nevents = uap->nevents, 1181 .timeout = uap->timeout, 1182 }; 1183 1184 return (kern_kevent_generic(td, &gk_args, &k_ops, "kevent_freebsd11")); 1185 } 1186 #endif 1187 1188 int 1189 kern_kevent(struct thread *td, int fd, int nchanges, int nevents, 1190 struct kevent_copyops *k_ops, const struct timespec *timeout) 1191 { 1192 cap_rights_t rights; 1193 struct file *fp; 1194 int error; 1195 1196 cap_rights_init(&rights); 1197 if (nchanges > 0) 1198 cap_rights_set(&rights, CAP_KQUEUE_CHANGE); 1199 if (nevents > 0) 1200 cap_rights_set(&rights, CAP_KQUEUE_EVENT); 1201 error = fget(td, fd, &rights, &fp); 1202 if (error != 0) 1203 return (error); 1204 1205 error = kern_kevent_fp(td, fp, nchanges, nevents, k_ops, timeout); 1206 fdrop(fp, td); 1207 1208 return (error); 1209 } 1210 1211 static int 1212 kqueue_kevent(struct kqueue *kq, struct thread *td, int nchanges, int nevents, 1213 struct kevent_copyops *k_ops, const struct timespec *timeout) 1214 { 1215 struct kevent keva[KQ_NEVENTS]; 1216 struct kevent *kevp, *changes; 1217 int i, n, nerrors, error; 1218 1219 nerrors = 0; 1220 while (nchanges > 0) { 1221 n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges; 1222 error = k_ops->k_copyin(k_ops->arg, keva, n); 1223 if (error) 1224 return (error); 1225 changes = keva; 1226 for (i = 0; i < n; i++) { 1227 kevp = &changes[i]; 1228 if (!kevp->filter) 1229 continue; 1230 kevp->flags &= ~EV_SYSFLAGS; 1231 error = kqueue_register(kq, kevp, td, 1); 1232 if (error || (kevp->flags & EV_RECEIPT)) { 1233 if (nevents == 0) 1234 return (error); 1235 kevp->flags = EV_ERROR; 1236 kevp->data = error; 1237 (void)k_ops->k_copyout(k_ops->arg, kevp, 1); 1238 nevents--; 1239 nerrors++; 1240 } 1241 } 1242 nchanges -= n; 1243 } 1244 if (nerrors) { 1245 td->td_retval[0] = nerrors; 1246 return (0); 1247 } 1248 1249 return (kqueue_scan(kq, nevents, k_ops, timeout, keva, td)); 1250 } 1251 1252 int 1253 kern_kevent_fp(struct thread *td, struct file *fp, int nchanges, int nevents, 1254 struct kevent_copyops *k_ops, const struct timespec *timeout) 1255 { 1256 struct kqueue *kq; 1257 int error; 1258 1259 error = kqueue_acquire(fp, &kq); 1260 if (error != 0) 1261 return (error); 1262 error = kqueue_kevent(kq, td, nchanges, nevents, k_ops, timeout); 1263 kqueue_release(kq, 0); 1264 return (error); 1265 } 1266 1267 /* 1268 * Performs a kevent() call on a temporarily created kqueue. This can be 1269 * used to perform one-shot polling, similar to poll() and select(). 1270 */ 1271 int 1272 kern_kevent_anonymous(struct thread *td, int nevents, 1273 struct kevent_copyops *k_ops) 1274 { 1275 struct kqueue kq = {}; 1276 int error; 1277 1278 kqueue_init(&kq); 1279 kq.kq_refcnt = 1; 1280 error = kqueue_kevent(&kq, td, nevents, nevents, k_ops, NULL); 1281 kqueue_drain(&kq, td); 1282 kqueue_destroy(&kq); 1283 return (error); 1284 } 1285 1286 int 1287 kqueue_add_filteropts(int filt, struct filterops *filtops) 1288 { 1289 int error; 1290 1291 error = 0; 1292 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) { 1293 printf( 1294 "trying to add a filterop that is out of range: %d is beyond %d\n", 1295 ~filt, EVFILT_SYSCOUNT); 1296 return EINVAL; 1297 } 1298 mtx_lock(&filterops_lock); 1299 if (sysfilt_ops[~filt].for_fop != &null_filtops && 1300 sysfilt_ops[~filt].for_fop != NULL) 1301 error = EEXIST; 1302 else { 1303 sysfilt_ops[~filt].for_fop = filtops; 1304 sysfilt_ops[~filt].for_refcnt = 0; 1305 } 1306 mtx_unlock(&filterops_lock); 1307 1308 return (error); 1309 } 1310 1311 int 1312 kqueue_del_filteropts(int filt) 1313 { 1314 int error; 1315 1316 error = 0; 1317 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1318 return EINVAL; 1319 1320 mtx_lock(&filterops_lock); 1321 if (sysfilt_ops[~filt].for_fop == &null_filtops || 1322 sysfilt_ops[~filt].for_fop == NULL) 1323 error = EINVAL; 1324 else if (sysfilt_ops[~filt].for_refcnt != 0) 1325 error = EBUSY; 1326 else { 1327 sysfilt_ops[~filt].for_fop = &null_filtops; 1328 sysfilt_ops[~filt].for_refcnt = 0; 1329 } 1330 mtx_unlock(&filterops_lock); 1331 1332 return error; 1333 } 1334 1335 static struct filterops * 1336 kqueue_fo_find(int filt) 1337 { 1338 1339 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1340 return NULL; 1341 1342 if (sysfilt_ops[~filt].for_nolock) 1343 return sysfilt_ops[~filt].for_fop; 1344 1345 mtx_lock(&filterops_lock); 1346 sysfilt_ops[~filt].for_refcnt++; 1347 if (sysfilt_ops[~filt].for_fop == NULL) 1348 sysfilt_ops[~filt].for_fop = &null_filtops; 1349 mtx_unlock(&filterops_lock); 1350 1351 return sysfilt_ops[~filt].for_fop; 1352 } 1353 1354 static void 1355 kqueue_fo_release(int filt) 1356 { 1357 1358 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1359 return; 1360 1361 if (sysfilt_ops[~filt].for_nolock) 1362 return; 1363 1364 mtx_lock(&filterops_lock); 1365 KASSERT(sysfilt_ops[~filt].for_refcnt > 0, 1366 ("filter object refcount not valid on release")); 1367 sysfilt_ops[~filt].for_refcnt--; 1368 mtx_unlock(&filterops_lock); 1369 } 1370 1371 /* 1372 * A ref to kq (obtained via kqueue_acquire) must be held. waitok will 1373 * influence if memory allocation should wait. Make sure it is 0 if you 1374 * hold any mutexes. 1375 */ 1376 static int 1377 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, int waitok) 1378 { 1379 struct filterops *fops; 1380 struct file *fp; 1381 struct knote *kn, *tkn; 1382 struct knlist *knl; 1383 int error, filt, event; 1384 int haskqglobal, filedesc_unlock; 1385 1386 if ((kev->flags & (EV_ENABLE | EV_DISABLE)) == (EV_ENABLE | EV_DISABLE)) 1387 return (EINVAL); 1388 1389 fp = NULL; 1390 kn = NULL; 1391 knl = NULL; 1392 error = 0; 1393 haskqglobal = 0; 1394 filedesc_unlock = 0; 1395 1396 filt = kev->filter; 1397 fops = kqueue_fo_find(filt); 1398 if (fops == NULL) 1399 return EINVAL; 1400 1401 if (kev->flags & EV_ADD) { 1402 /* 1403 * Prevent waiting with locks. Non-sleepable 1404 * allocation failures are handled in the loop, only 1405 * if the spare knote appears to be actually required. 1406 */ 1407 tkn = knote_alloc(waitok); 1408 } else { 1409 tkn = NULL; 1410 } 1411 1412 findkn: 1413 if (fops->f_isfd) { 1414 KASSERT(td != NULL, ("td is NULL")); 1415 if (kev->ident > INT_MAX) 1416 error = EBADF; 1417 else 1418 error = fget(td, kev->ident, &cap_event_rights, &fp); 1419 if (error) 1420 goto done; 1421 1422 if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops, 1423 kev->ident, 0) != 0) { 1424 /* try again */ 1425 fdrop(fp, td); 1426 fp = NULL; 1427 error = kqueue_expand(kq, fops, kev->ident, waitok); 1428 if (error) 1429 goto done; 1430 goto findkn; 1431 } 1432 1433 if (fp->f_type == DTYPE_KQUEUE) { 1434 /* 1435 * If we add some intelligence about what we are doing, 1436 * we should be able to support events on ourselves. 1437 * We need to know when we are doing this to prevent 1438 * getting both the knlist lock and the kq lock since 1439 * they are the same thing. 1440 */ 1441 if (fp->f_data == kq) { 1442 error = EINVAL; 1443 goto done; 1444 } 1445 1446 /* 1447 * Pre-lock the filedesc before the global 1448 * lock mutex, see the comment in 1449 * kqueue_close(). 1450 */ 1451 FILEDESC_XLOCK(td->td_proc->p_fd); 1452 filedesc_unlock = 1; 1453 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1454 } 1455 1456 KQ_LOCK(kq); 1457 if (kev->ident < kq->kq_knlistsize) { 1458 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link) 1459 if (kev->filter == kn->kn_filter) 1460 break; 1461 } 1462 } else { 1463 if ((kev->flags & EV_ADD) == EV_ADD) { 1464 error = kqueue_expand(kq, fops, kev->ident, waitok); 1465 if (error != 0) 1466 goto done; 1467 } 1468 1469 KQ_LOCK(kq); 1470 1471 /* 1472 * If possible, find an existing knote to use for this kevent. 1473 */ 1474 if (kev->filter == EVFILT_PROC && 1475 (kev->flags & (EV_FLAG1 | EV_FLAG2)) != 0) { 1476 /* This is an internal creation of a process tracking 1477 * note. Don't attempt to coalesce this with an 1478 * existing note. 1479 */ 1480 ; 1481 } else if (kq->kq_knhashmask != 0) { 1482 struct klist *list; 1483 1484 list = &kq->kq_knhash[ 1485 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)]; 1486 SLIST_FOREACH(kn, list, kn_link) 1487 if (kev->ident == kn->kn_id && 1488 kev->filter == kn->kn_filter) 1489 break; 1490 } 1491 } 1492 1493 /* knote is in the process of changing, wait for it to stabilize. */ 1494 if (kn != NULL && kn_in_flux(kn)) { 1495 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1496 if (filedesc_unlock) { 1497 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1498 filedesc_unlock = 0; 1499 } 1500 kq->kq_state |= KQ_FLUXWAIT; 1501 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0); 1502 if (fp != NULL) { 1503 fdrop(fp, td); 1504 fp = NULL; 1505 } 1506 goto findkn; 1507 } 1508 1509 /* 1510 * kn now contains the matching knote, or NULL if no match 1511 */ 1512 if (kn == NULL) { 1513 if (kev->flags & EV_ADD) { 1514 kn = tkn; 1515 tkn = NULL; 1516 if (kn == NULL) { 1517 KQ_UNLOCK(kq); 1518 error = ENOMEM; 1519 goto done; 1520 } 1521 kn->kn_fp = fp; 1522 kn->kn_kq = kq; 1523 kn->kn_fop = fops; 1524 /* 1525 * apply reference counts to knote structure, and 1526 * do not release it at the end of this routine. 1527 */ 1528 fops = NULL; 1529 fp = NULL; 1530 1531 kn->kn_sfflags = kev->fflags; 1532 kn->kn_sdata = kev->data; 1533 kev->fflags = 0; 1534 kev->data = 0; 1535 kn->kn_kevent = *kev; 1536 kn->kn_kevent.flags &= ~(EV_ADD | EV_DELETE | 1537 EV_ENABLE | EV_DISABLE | EV_FORCEONESHOT); 1538 kn->kn_status = KN_DETACHED; 1539 if ((kev->flags & EV_DISABLE) != 0) 1540 kn->kn_status |= KN_DISABLED; 1541 kn_enter_flux(kn); 1542 1543 error = knote_attach(kn, kq); 1544 KQ_UNLOCK(kq); 1545 if (error != 0) { 1546 tkn = kn; 1547 goto done; 1548 } 1549 1550 if ((error = kn->kn_fop->f_attach(kn)) != 0) { 1551 knote_drop_detached(kn, td); 1552 goto done; 1553 } 1554 knl = kn_list_lock(kn); 1555 goto done_ev_add; 1556 } else { 1557 /* No matching knote and the EV_ADD flag is not set. */ 1558 KQ_UNLOCK(kq); 1559 error = ENOENT; 1560 goto done; 1561 } 1562 } 1563 1564 if (kev->flags & EV_DELETE) { 1565 kn_enter_flux(kn); 1566 KQ_UNLOCK(kq); 1567 knote_drop(kn, td); 1568 goto done; 1569 } 1570 1571 if (kev->flags & EV_FORCEONESHOT) { 1572 kn->kn_flags |= EV_ONESHOT; 1573 KNOTE_ACTIVATE(kn, 1); 1574 } 1575 1576 if ((kev->flags & EV_ENABLE) != 0) 1577 kn->kn_status &= ~KN_DISABLED; 1578 else if ((kev->flags & EV_DISABLE) != 0) 1579 kn->kn_status |= KN_DISABLED; 1580 1581 /* 1582 * The user may change some filter values after the initial EV_ADD, 1583 * but doing so will not reset any filter which has already been 1584 * triggered. 1585 */ 1586 kn->kn_status |= KN_SCAN; 1587 kn_enter_flux(kn); 1588 KQ_UNLOCK(kq); 1589 knl = kn_list_lock(kn); 1590 kn->kn_kevent.udata = kev->udata; 1591 if (!fops->f_isfd && fops->f_touch != NULL) { 1592 fops->f_touch(kn, kev, EVENT_REGISTER); 1593 } else { 1594 kn->kn_sfflags = kev->fflags; 1595 kn->kn_sdata = kev->data; 1596 } 1597 1598 done_ev_add: 1599 /* 1600 * We can get here with kn->kn_knlist == NULL. This can happen when 1601 * the initial attach event decides that the event is "completed" 1602 * already, e.g., filt_procattach() is called on a zombie process. It 1603 * will call filt_proc() which will remove it from the list, and NULL 1604 * kn_knlist. 1605 * 1606 * KN_DISABLED will be stable while the knote is in flux, so the 1607 * unlocked read will not race with an update. 1608 */ 1609 if ((kn->kn_status & KN_DISABLED) == 0) 1610 event = kn->kn_fop->f_event(kn, 0); 1611 else 1612 event = 0; 1613 1614 KQ_LOCK(kq); 1615 if (event) 1616 kn->kn_status |= KN_ACTIVE; 1617 if ((kn->kn_status & (KN_ACTIVE | KN_DISABLED | KN_QUEUED)) == 1618 KN_ACTIVE) 1619 knote_enqueue(kn); 1620 kn->kn_status &= ~KN_SCAN; 1621 kn_leave_flux(kn); 1622 kn_list_unlock(knl); 1623 KQ_UNLOCK_FLUX(kq); 1624 1625 done: 1626 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1627 if (filedesc_unlock) 1628 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1629 if (fp != NULL) 1630 fdrop(fp, td); 1631 knote_free(tkn); 1632 if (fops != NULL) 1633 kqueue_fo_release(filt); 1634 return (error); 1635 } 1636 1637 static int 1638 kqueue_acquire(struct file *fp, struct kqueue **kqp) 1639 { 1640 int error; 1641 struct kqueue *kq; 1642 1643 error = 0; 1644 1645 kq = fp->f_data; 1646 if (fp->f_type != DTYPE_KQUEUE || kq == NULL) 1647 return (EBADF); 1648 *kqp = kq; 1649 KQ_LOCK(kq); 1650 if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) { 1651 KQ_UNLOCK(kq); 1652 return (EBADF); 1653 } 1654 kq->kq_refcnt++; 1655 KQ_UNLOCK(kq); 1656 1657 return error; 1658 } 1659 1660 static void 1661 kqueue_release(struct kqueue *kq, int locked) 1662 { 1663 if (locked) 1664 KQ_OWNED(kq); 1665 else 1666 KQ_LOCK(kq); 1667 kq->kq_refcnt--; 1668 if (kq->kq_refcnt == 1) 1669 wakeup(&kq->kq_refcnt); 1670 if (!locked) 1671 KQ_UNLOCK(kq); 1672 } 1673 1674 static void 1675 kqueue_schedtask(struct kqueue *kq) 1676 { 1677 1678 KQ_OWNED(kq); 1679 KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN), 1680 ("scheduling kqueue task while draining")); 1681 1682 if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) { 1683 taskqueue_enqueue(taskqueue_kqueue_ctx, &kq->kq_task); 1684 kq->kq_state |= KQ_TASKSCHED; 1685 } 1686 } 1687 1688 /* 1689 * Expand the kq to make sure we have storage for fops/ident pair. 1690 * 1691 * Return 0 on success (or no work necessary), return errno on failure. 1692 */ 1693 static int 1694 kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident, 1695 int waitok) 1696 { 1697 struct klist *list, *tmp_knhash, *to_free; 1698 u_long tmp_knhashmask; 1699 int error, fd, size; 1700 int mflag = waitok ? M_WAITOK : M_NOWAIT; 1701 1702 KQ_NOTOWNED(kq); 1703 1704 error = 0; 1705 to_free = NULL; 1706 if (fops->f_isfd) { 1707 fd = ident; 1708 if (kq->kq_knlistsize <= fd) { 1709 size = kq->kq_knlistsize; 1710 while (size <= fd) 1711 size += KQEXTENT; 1712 list = malloc(size * sizeof(*list), M_KQUEUE, mflag); 1713 if (list == NULL) 1714 return ENOMEM; 1715 KQ_LOCK(kq); 1716 if ((kq->kq_state & KQ_CLOSING) != 0) { 1717 to_free = list; 1718 error = EBADF; 1719 } else if (kq->kq_knlistsize > fd) { 1720 to_free = list; 1721 } else { 1722 if (kq->kq_knlist != NULL) { 1723 bcopy(kq->kq_knlist, list, 1724 kq->kq_knlistsize * sizeof(*list)); 1725 to_free = kq->kq_knlist; 1726 kq->kq_knlist = NULL; 1727 } 1728 bzero((caddr_t)list + 1729 kq->kq_knlistsize * sizeof(*list), 1730 (size - kq->kq_knlistsize) * sizeof(*list)); 1731 kq->kq_knlistsize = size; 1732 kq->kq_knlist = list; 1733 } 1734 KQ_UNLOCK(kq); 1735 } 1736 } else { 1737 if (kq->kq_knhashmask == 0) { 1738 tmp_knhash = hashinit_flags(KN_HASHSIZE, M_KQUEUE, 1739 &tmp_knhashmask, 1740 waitok ? HASH_WAITOK : HASH_NOWAIT); 1741 if (tmp_knhash == NULL) 1742 return (ENOMEM); 1743 KQ_LOCK(kq); 1744 if ((kq->kq_state & KQ_CLOSING) != 0) { 1745 to_free = tmp_knhash; 1746 error = EBADF; 1747 } else if (kq->kq_knhashmask == 0) { 1748 kq->kq_knhash = tmp_knhash; 1749 kq->kq_knhashmask = tmp_knhashmask; 1750 } else { 1751 to_free = tmp_knhash; 1752 } 1753 KQ_UNLOCK(kq); 1754 } 1755 } 1756 free(to_free, M_KQUEUE); 1757 1758 KQ_NOTOWNED(kq); 1759 return (error); 1760 } 1761 1762 static void 1763 kqueue_task(void *arg, int pending) 1764 { 1765 struct kqueue *kq; 1766 int haskqglobal; 1767 1768 haskqglobal = 0; 1769 kq = arg; 1770 1771 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1772 KQ_LOCK(kq); 1773 1774 KNOTE_LOCKED(&kq->kq_sel.si_note, 0); 1775 1776 kq->kq_state &= ~KQ_TASKSCHED; 1777 if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) { 1778 wakeup(&kq->kq_state); 1779 } 1780 KQ_UNLOCK(kq); 1781 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1782 } 1783 1784 /* 1785 * Scan, update kn_data (if not ONESHOT), and copyout triggered events. 1786 * We treat KN_MARKER knotes as if they are in flux. 1787 */ 1788 static int 1789 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops, 1790 const struct timespec *tsp, struct kevent *keva, struct thread *td) 1791 { 1792 struct kevent *kevp; 1793 struct knote *kn, *marker; 1794 struct knlist *knl; 1795 sbintime_t asbt, rsbt; 1796 int count, error, haskqglobal, influx, nkev, touch; 1797 1798 count = maxevents; 1799 nkev = 0; 1800 error = 0; 1801 haskqglobal = 0; 1802 1803 if (maxevents == 0) 1804 goto done_nl; 1805 1806 rsbt = 0; 1807 if (tsp != NULL) { 1808 if (tsp->tv_sec < 0 || tsp->tv_nsec < 0 || 1809 tsp->tv_nsec >= 1000000000) { 1810 error = EINVAL; 1811 goto done_nl; 1812 } 1813 if (timespecisset(tsp)) { 1814 if (tsp->tv_sec <= INT32_MAX) { 1815 rsbt = tstosbt(*tsp); 1816 if (TIMESEL(&asbt, rsbt)) 1817 asbt += tc_tick_sbt; 1818 if (asbt <= SBT_MAX - rsbt) 1819 asbt += rsbt; 1820 else 1821 asbt = 0; 1822 rsbt >>= tc_precexp; 1823 } else 1824 asbt = 0; 1825 } else 1826 asbt = -1; 1827 } else 1828 asbt = 0; 1829 marker = knote_alloc(1); 1830 marker->kn_status = KN_MARKER; 1831 KQ_LOCK(kq); 1832 1833 retry: 1834 kevp = keva; 1835 if (kq->kq_count == 0) { 1836 if (asbt == -1) { 1837 error = EWOULDBLOCK; 1838 } else { 1839 kq->kq_state |= KQ_SLEEP; 1840 error = msleep_sbt(kq, &kq->kq_lock, PSOCK | PCATCH, 1841 "kqread", asbt, rsbt, C_ABSOLUTE); 1842 } 1843 if (error == 0) 1844 goto retry; 1845 /* don't restart after signals... */ 1846 if (error == ERESTART) 1847 error = EINTR; 1848 else if (error == EWOULDBLOCK) 1849 error = 0; 1850 goto done; 1851 } 1852 1853 TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); 1854 influx = 0; 1855 while (count) { 1856 KQ_OWNED(kq); 1857 kn = TAILQ_FIRST(&kq->kq_head); 1858 1859 if ((kn->kn_status == KN_MARKER && kn != marker) || 1860 kn_in_flux(kn)) { 1861 if (influx) { 1862 influx = 0; 1863 KQ_FLUX_WAKEUP(kq); 1864 } 1865 kq->kq_state |= KQ_FLUXWAIT; 1866 error = msleep(kq, &kq->kq_lock, PSOCK, 1867 "kqflxwt", 0); 1868 continue; 1869 } 1870 1871 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1872 if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) { 1873 kn->kn_status &= ~KN_QUEUED; 1874 kq->kq_count--; 1875 continue; 1876 } 1877 if (kn == marker) { 1878 KQ_FLUX_WAKEUP(kq); 1879 if (count == maxevents) 1880 goto retry; 1881 goto done; 1882 } 1883 KASSERT(!kn_in_flux(kn), 1884 ("knote %p is unexpectedly in flux", kn)); 1885 1886 if ((kn->kn_flags & EV_DROP) == EV_DROP) { 1887 kn->kn_status &= ~KN_QUEUED; 1888 kn_enter_flux(kn); 1889 kq->kq_count--; 1890 KQ_UNLOCK(kq); 1891 /* 1892 * We don't need to lock the list since we've 1893 * marked it as in flux. 1894 */ 1895 knote_drop(kn, td); 1896 KQ_LOCK(kq); 1897 continue; 1898 } else if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) { 1899 kn->kn_status &= ~KN_QUEUED; 1900 kn_enter_flux(kn); 1901 kq->kq_count--; 1902 KQ_UNLOCK(kq); 1903 /* 1904 * We don't need to lock the list since we've 1905 * marked the knote as being in flux. 1906 */ 1907 *kevp = kn->kn_kevent; 1908 knote_drop(kn, td); 1909 KQ_LOCK(kq); 1910 kn = NULL; 1911 } else { 1912 kn->kn_status |= KN_SCAN; 1913 kn_enter_flux(kn); 1914 KQ_UNLOCK(kq); 1915 if ((kn->kn_status & KN_KQUEUE) == KN_KQUEUE) 1916 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1917 knl = kn_list_lock(kn); 1918 if (kn->kn_fop->f_event(kn, 0) == 0) { 1919 KQ_LOCK(kq); 1920 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1921 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE | 1922 KN_SCAN); 1923 kn_leave_flux(kn); 1924 kq->kq_count--; 1925 kn_list_unlock(knl); 1926 influx = 1; 1927 continue; 1928 } 1929 touch = (!kn->kn_fop->f_isfd && 1930 kn->kn_fop->f_touch != NULL); 1931 if (touch) 1932 kn->kn_fop->f_touch(kn, kevp, EVENT_PROCESS); 1933 else 1934 *kevp = kn->kn_kevent; 1935 KQ_LOCK(kq); 1936 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1937 if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) { 1938 /* 1939 * Manually clear knotes who weren't 1940 * 'touch'ed. 1941 */ 1942 if (touch == 0 && kn->kn_flags & EV_CLEAR) { 1943 kn->kn_data = 0; 1944 kn->kn_fflags = 0; 1945 } 1946 if (kn->kn_flags & EV_DISPATCH) 1947 kn->kn_status |= KN_DISABLED; 1948 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 1949 kq->kq_count--; 1950 } else 1951 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 1952 1953 kn->kn_status &= ~KN_SCAN; 1954 kn_leave_flux(kn); 1955 kn_list_unlock(knl); 1956 influx = 1; 1957 } 1958 1959 /* we are returning a copy to the user */ 1960 kevp++; 1961 nkev++; 1962 count--; 1963 1964 if (nkev == KQ_NEVENTS) { 1965 influx = 0; 1966 KQ_UNLOCK_FLUX(kq); 1967 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1968 nkev = 0; 1969 kevp = keva; 1970 KQ_LOCK(kq); 1971 if (error) 1972 break; 1973 } 1974 } 1975 TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); 1976 done: 1977 KQ_OWNED(kq); 1978 KQ_UNLOCK_FLUX(kq); 1979 knote_free(marker); 1980 done_nl: 1981 KQ_NOTOWNED(kq); 1982 if (nkev != 0) 1983 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1984 td->td_retval[0] = maxevents - count; 1985 return (error); 1986 } 1987 1988 /*ARGSUSED*/ 1989 static int 1990 kqueue_ioctl(struct file *fp, u_long cmd, void *data, 1991 struct ucred *active_cred, struct thread *td) 1992 { 1993 /* 1994 * Enabling sigio causes two major problems: 1995 * 1) infinite recursion: 1996 * Synopsys: kevent is being used to track signals and have FIOASYNC 1997 * set. On receipt of a signal this will cause a kqueue to recurse 1998 * into itself over and over. Sending the sigio causes the kqueue 1999 * to become ready, which in turn posts sigio again, forever. 2000 * Solution: this can be solved by setting a flag in the kqueue that 2001 * we have a SIGIO in progress. 2002 * 2) locking problems: 2003 * Synopsys: Kqueue is a leaf subsystem, but adding signalling puts 2004 * us above the proc and pgrp locks. 2005 * Solution: Post a signal using an async mechanism, being sure to 2006 * record a generation count in the delivery so that we do not deliver 2007 * a signal to the wrong process. 2008 * 2009 * Note, these two mechanisms are somewhat mutually exclusive! 2010 */ 2011 #if 0 2012 struct kqueue *kq; 2013 2014 kq = fp->f_data; 2015 switch (cmd) { 2016 case FIOASYNC: 2017 if (*(int *)data) { 2018 kq->kq_state |= KQ_ASYNC; 2019 } else { 2020 kq->kq_state &= ~KQ_ASYNC; 2021 } 2022 return (0); 2023 2024 case FIOSETOWN: 2025 return (fsetown(*(int *)data, &kq->kq_sigio)); 2026 2027 case FIOGETOWN: 2028 *(int *)data = fgetown(&kq->kq_sigio); 2029 return (0); 2030 } 2031 #endif 2032 2033 return (ENOTTY); 2034 } 2035 2036 /*ARGSUSED*/ 2037 static int 2038 kqueue_poll(struct file *fp, int events, struct ucred *active_cred, 2039 struct thread *td) 2040 { 2041 struct kqueue *kq; 2042 int revents = 0; 2043 int error; 2044 2045 if ((error = kqueue_acquire(fp, &kq))) 2046 return POLLERR; 2047 2048 KQ_LOCK(kq); 2049 if (events & (POLLIN | POLLRDNORM)) { 2050 if (kq->kq_count) { 2051 revents |= events & (POLLIN | POLLRDNORM); 2052 } else { 2053 selrecord(td, &kq->kq_sel); 2054 if (SEL_WAITING(&kq->kq_sel)) 2055 kq->kq_state |= KQ_SEL; 2056 } 2057 } 2058 kqueue_release(kq, 1); 2059 KQ_UNLOCK(kq); 2060 return (revents); 2061 } 2062 2063 /*ARGSUSED*/ 2064 static int 2065 kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred, 2066 struct thread *td) 2067 { 2068 2069 bzero((void *)st, sizeof *st); 2070 /* 2071 * We no longer return kq_count because the unlocked value is useless. 2072 * If you spent all this time getting the count, why not spend your 2073 * syscall better by calling kevent? 2074 * 2075 * XXX - This is needed for libc_r. 2076 */ 2077 st->st_mode = S_IFIFO; 2078 return (0); 2079 } 2080 2081 static void 2082 kqueue_drain(struct kqueue *kq, struct thread *td) 2083 { 2084 struct knote *kn; 2085 int i; 2086 2087 KQ_LOCK(kq); 2088 2089 KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING, 2090 ("kqueue already closing")); 2091 kq->kq_state |= KQ_CLOSING; 2092 if (kq->kq_refcnt > 1) 2093 msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0); 2094 2095 KASSERT(kq->kq_refcnt == 1, ("other refs are out there!")); 2096 2097 KASSERT(knlist_empty(&kq->kq_sel.si_note), 2098 ("kqueue's knlist not empty")); 2099 2100 for (i = 0; i < kq->kq_knlistsize; i++) { 2101 while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) { 2102 if (kn_in_flux(kn)) { 2103 kq->kq_state |= KQ_FLUXWAIT; 2104 msleep(kq, &kq->kq_lock, PSOCK, "kqclo1", 0); 2105 continue; 2106 } 2107 kn_enter_flux(kn); 2108 KQ_UNLOCK(kq); 2109 knote_drop(kn, td); 2110 KQ_LOCK(kq); 2111 } 2112 } 2113 if (kq->kq_knhashmask != 0) { 2114 for (i = 0; i <= kq->kq_knhashmask; i++) { 2115 while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) { 2116 if (kn_in_flux(kn)) { 2117 kq->kq_state |= KQ_FLUXWAIT; 2118 msleep(kq, &kq->kq_lock, PSOCK, 2119 "kqclo2", 0); 2120 continue; 2121 } 2122 kn_enter_flux(kn); 2123 KQ_UNLOCK(kq); 2124 knote_drop(kn, td); 2125 KQ_LOCK(kq); 2126 } 2127 } 2128 } 2129 2130 if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) { 2131 kq->kq_state |= KQ_TASKDRAIN; 2132 msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0); 2133 } 2134 2135 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2136 selwakeuppri(&kq->kq_sel, PSOCK); 2137 if (!SEL_WAITING(&kq->kq_sel)) 2138 kq->kq_state &= ~KQ_SEL; 2139 } 2140 2141 KQ_UNLOCK(kq); 2142 } 2143 2144 static void 2145 kqueue_destroy(struct kqueue *kq) 2146 { 2147 2148 KASSERT(kq->kq_fdp == NULL, 2149 ("kqueue still attached to a file descriptor")); 2150 seldrain(&kq->kq_sel); 2151 knlist_destroy(&kq->kq_sel.si_note); 2152 mtx_destroy(&kq->kq_lock); 2153 2154 if (kq->kq_knhash != NULL) 2155 free(kq->kq_knhash, M_KQUEUE); 2156 if (kq->kq_knlist != NULL) 2157 free(kq->kq_knlist, M_KQUEUE); 2158 2159 funsetown(&kq->kq_sigio); 2160 } 2161 2162 /*ARGSUSED*/ 2163 static int 2164 kqueue_close(struct file *fp, struct thread *td) 2165 { 2166 struct kqueue *kq = fp->f_data; 2167 struct filedesc *fdp; 2168 int error; 2169 int filedesc_unlock; 2170 2171 if ((error = kqueue_acquire(fp, &kq))) 2172 return error; 2173 kqueue_drain(kq, td); 2174 2175 /* 2176 * We could be called due to the knote_drop() doing fdrop(), 2177 * called from kqueue_register(). In this case the global 2178 * lock is owned, and filedesc sx is locked before, to not 2179 * take the sleepable lock after non-sleepable. 2180 */ 2181 fdp = kq->kq_fdp; 2182 kq->kq_fdp = NULL; 2183 if (!sx_xlocked(FILEDESC_LOCK(fdp))) { 2184 FILEDESC_XLOCK(fdp); 2185 filedesc_unlock = 1; 2186 } else 2187 filedesc_unlock = 0; 2188 TAILQ_REMOVE(&fdp->fd_kqlist, kq, kq_list); 2189 if (filedesc_unlock) 2190 FILEDESC_XUNLOCK(fdp); 2191 2192 kqueue_destroy(kq); 2193 chgkqcnt(kq->kq_cred->cr_ruidinfo, -1, 0); 2194 crfree(kq->kq_cred); 2195 free(kq, M_KQUEUE); 2196 fp->f_data = NULL; 2197 2198 return (0); 2199 } 2200 2201 static int 2202 kqueue_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 2203 { 2204 2205 kif->kf_type = KF_TYPE_KQUEUE; 2206 return (0); 2207 } 2208 2209 static void 2210 kqueue_wakeup(struct kqueue *kq) 2211 { 2212 KQ_OWNED(kq); 2213 2214 if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) { 2215 kq->kq_state &= ~KQ_SLEEP; 2216 wakeup(kq); 2217 } 2218 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2219 selwakeuppri(&kq->kq_sel, PSOCK); 2220 if (!SEL_WAITING(&kq->kq_sel)) 2221 kq->kq_state &= ~KQ_SEL; 2222 } 2223 if (!knlist_empty(&kq->kq_sel.si_note)) 2224 kqueue_schedtask(kq); 2225 if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) { 2226 pgsigio(&kq->kq_sigio, SIGIO, 0); 2227 } 2228 } 2229 2230 /* 2231 * Walk down a list of knotes, activating them if their event has triggered. 2232 * 2233 * There is a possibility to optimize in the case of one kq watching another. 2234 * Instead of scheduling a task to wake it up, you could pass enough state 2235 * down the chain to make up the parent kqueue. Make this code functional 2236 * first. 2237 */ 2238 void 2239 knote(struct knlist *list, long hint, int lockflags) 2240 { 2241 struct kqueue *kq; 2242 struct knote *kn, *tkn; 2243 int error; 2244 2245 if (list == NULL) 2246 return; 2247 2248 KNL_ASSERT_LOCK(list, lockflags & KNF_LISTLOCKED); 2249 2250 if ((lockflags & KNF_LISTLOCKED) == 0) 2251 list->kl_lock(list->kl_lockarg); 2252 2253 /* 2254 * If we unlock the list lock (and enter influx), we can 2255 * eliminate the kqueue scheduling, but this will introduce 2256 * four lock/unlock's for each knote to test. Also, marker 2257 * would be needed to keep iteration position, since filters 2258 * or other threads could remove events. 2259 */ 2260 SLIST_FOREACH_SAFE(kn, &list->kl_list, kn_selnext, tkn) { 2261 kq = kn->kn_kq; 2262 KQ_LOCK(kq); 2263 if (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0) { 2264 /* 2265 * Do not process the influx notes, except for 2266 * the influx coming from the kq unlock in the 2267 * kqueue_scan(). In the later case, we do 2268 * not interfere with the scan, since the code 2269 * fragment in kqueue_scan() locks the knlist, 2270 * and cannot proceed until we finished. 2271 */ 2272 KQ_UNLOCK(kq); 2273 } else if ((lockflags & KNF_NOKQLOCK) != 0) { 2274 kn_enter_flux(kn); 2275 KQ_UNLOCK(kq); 2276 error = kn->kn_fop->f_event(kn, hint); 2277 KQ_LOCK(kq); 2278 kn_leave_flux(kn); 2279 if (error) 2280 KNOTE_ACTIVATE(kn, 1); 2281 KQ_UNLOCK_FLUX(kq); 2282 } else { 2283 if (kn->kn_fop->f_event(kn, hint)) 2284 KNOTE_ACTIVATE(kn, 1); 2285 KQ_UNLOCK(kq); 2286 } 2287 } 2288 if ((lockflags & KNF_LISTLOCKED) == 0) 2289 list->kl_unlock(list->kl_lockarg); 2290 } 2291 2292 /* 2293 * add a knote to a knlist 2294 */ 2295 void 2296 knlist_add(struct knlist *knl, struct knote *kn, int islocked) 2297 { 2298 2299 KNL_ASSERT_LOCK(knl, islocked); 2300 KQ_NOTOWNED(kn->kn_kq); 2301 KASSERT(kn_in_flux(kn), ("knote %p not in flux", kn)); 2302 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2303 ("knote %p was not detached", kn)); 2304 if (!islocked) 2305 knl->kl_lock(knl->kl_lockarg); 2306 SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext); 2307 if (!islocked) 2308 knl->kl_unlock(knl->kl_lockarg); 2309 KQ_LOCK(kn->kn_kq); 2310 kn->kn_knlist = knl; 2311 kn->kn_status &= ~KN_DETACHED; 2312 KQ_UNLOCK(kn->kn_kq); 2313 } 2314 2315 static void 2316 knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked, 2317 int kqislocked) 2318 { 2319 2320 KASSERT(!kqislocked || knlislocked, ("kq locked w/o knl locked")); 2321 KNL_ASSERT_LOCK(knl, knlislocked); 2322 mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED); 2323 KASSERT(kqislocked || kn_in_flux(kn), ("knote %p not in flux", kn)); 2324 KASSERT((kn->kn_status & KN_DETACHED) == 0, 2325 ("knote %p was already detached", kn)); 2326 if (!knlislocked) 2327 knl->kl_lock(knl->kl_lockarg); 2328 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext); 2329 kn->kn_knlist = NULL; 2330 if (!knlislocked) 2331 kn_list_unlock(knl); 2332 if (!kqislocked) 2333 KQ_LOCK(kn->kn_kq); 2334 kn->kn_status |= KN_DETACHED; 2335 if (!kqislocked) 2336 KQ_UNLOCK(kn->kn_kq); 2337 } 2338 2339 /* 2340 * remove knote from the specified knlist 2341 */ 2342 void 2343 knlist_remove(struct knlist *knl, struct knote *kn, int islocked) 2344 { 2345 2346 knlist_remove_kq(knl, kn, islocked, 0); 2347 } 2348 2349 int 2350 knlist_empty(struct knlist *knl) 2351 { 2352 2353 KNL_ASSERT_LOCKED(knl); 2354 return (SLIST_EMPTY(&knl->kl_list)); 2355 } 2356 2357 static struct mtx knlist_lock; 2358 MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects", 2359 MTX_DEF); 2360 static void knlist_mtx_lock(void *arg); 2361 static void knlist_mtx_unlock(void *arg); 2362 2363 static void 2364 knlist_mtx_lock(void *arg) 2365 { 2366 2367 mtx_lock((struct mtx *)arg); 2368 } 2369 2370 static void 2371 knlist_mtx_unlock(void *arg) 2372 { 2373 2374 mtx_unlock((struct mtx *)arg); 2375 } 2376 2377 static void 2378 knlist_mtx_assert_locked(void *arg) 2379 { 2380 2381 mtx_assert((struct mtx *)arg, MA_OWNED); 2382 } 2383 2384 static void 2385 knlist_mtx_assert_unlocked(void *arg) 2386 { 2387 2388 mtx_assert((struct mtx *)arg, MA_NOTOWNED); 2389 } 2390 2391 static void 2392 knlist_rw_rlock(void *arg) 2393 { 2394 2395 rw_rlock((struct rwlock *)arg); 2396 } 2397 2398 static void 2399 knlist_rw_runlock(void *arg) 2400 { 2401 2402 rw_runlock((struct rwlock *)arg); 2403 } 2404 2405 static void 2406 knlist_rw_assert_locked(void *arg) 2407 { 2408 2409 rw_assert((struct rwlock *)arg, RA_LOCKED); 2410 } 2411 2412 static void 2413 knlist_rw_assert_unlocked(void *arg) 2414 { 2415 2416 rw_assert((struct rwlock *)arg, RA_UNLOCKED); 2417 } 2418 2419 void 2420 knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *), 2421 void (*kl_unlock)(void *), 2422 void (*kl_assert_locked)(void *), void (*kl_assert_unlocked)(void *)) 2423 { 2424 2425 if (lock == NULL) 2426 knl->kl_lockarg = &knlist_lock; 2427 else 2428 knl->kl_lockarg = lock; 2429 2430 if (kl_lock == NULL) 2431 knl->kl_lock = knlist_mtx_lock; 2432 else 2433 knl->kl_lock = kl_lock; 2434 if (kl_unlock == NULL) 2435 knl->kl_unlock = knlist_mtx_unlock; 2436 else 2437 knl->kl_unlock = kl_unlock; 2438 if (kl_assert_locked == NULL) 2439 knl->kl_assert_locked = knlist_mtx_assert_locked; 2440 else 2441 knl->kl_assert_locked = kl_assert_locked; 2442 if (kl_assert_unlocked == NULL) 2443 knl->kl_assert_unlocked = knlist_mtx_assert_unlocked; 2444 else 2445 knl->kl_assert_unlocked = kl_assert_unlocked; 2446 2447 knl->kl_autodestroy = 0; 2448 SLIST_INIT(&knl->kl_list); 2449 } 2450 2451 void 2452 knlist_init_mtx(struct knlist *knl, struct mtx *lock) 2453 { 2454 2455 knlist_init(knl, lock, NULL, NULL, NULL, NULL); 2456 } 2457 2458 struct knlist * 2459 knlist_alloc(struct mtx *lock) 2460 { 2461 struct knlist *knl; 2462 2463 knl = malloc(sizeof(struct knlist), M_KQUEUE, M_WAITOK); 2464 knlist_init_mtx(knl, lock); 2465 return (knl); 2466 } 2467 2468 void 2469 knlist_init_rw_reader(struct knlist *knl, struct rwlock *lock) 2470 { 2471 2472 knlist_init(knl, lock, knlist_rw_rlock, knlist_rw_runlock, 2473 knlist_rw_assert_locked, knlist_rw_assert_unlocked); 2474 } 2475 2476 void 2477 knlist_destroy(struct knlist *knl) 2478 { 2479 2480 KASSERT(KNLIST_EMPTY(knl), 2481 ("destroying knlist %p with knotes on it", knl)); 2482 } 2483 2484 void 2485 knlist_detach(struct knlist *knl) 2486 { 2487 2488 KNL_ASSERT_LOCKED(knl); 2489 knl->kl_autodestroy = 1; 2490 if (knlist_empty(knl)) { 2491 knlist_destroy(knl); 2492 free(knl, M_KQUEUE); 2493 } 2494 } 2495 2496 /* 2497 * Even if we are locked, we may need to drop the lock to allow any influx 2498 * knotes time to "settle". 2499 */ 2500 void 2501 knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn) 2502 { 2503 struct knote *kn, *kn2; 2504 struct kqueue *kq; 2505 2506 KASSERT(!knl->kl_autodestroy, ("cleardel for autodestroy %p", knl)); 2507 if (islocked) 2508 KNL_ASSERT_LOCKED(knl); 2509 else { 2510 KNL_ASSERT_UNLOCKED(knl); 2511 again: /* need to reacquire lock since we have dropped it */ 2512 knl->kl_lock(knl->kl_lockarg); 2513 } 2514 2515 SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) { 2516 kq = kn->kn_kq; 2517 KQ_LOCK(kq); 2518 if (kn_in_flux(kn)) { 2519 KQ_UNLOCK(kq); 2520 continue; 2521 } 2522 knlist_remove_kq(knl, kn, 1, 1); 2523 if (killkn) { 2524 kn_enter_flux(kn); 2525 KQ_UNLOCK(kq); 2526 knote_drop_detached(kn, td); 2527 } else { 2528 /* Make sure cleared knotes disappear soon */ 2529 kn->kn_flags |= EV_EOF | EV_ONESHOT; 2530 KQ_UNLOCK(kq); 2531 } 2532 kq = NULL; 2533 } 2534 2535 if (!SLIST_EMPTY(&knl->kl_list)) { 2536 /* there are still in flux knotes remaining */ 2537 kn = SLIST_FIRST(&knl->kl_list); 2538 kq = kn->kn_kq; 2539 KQ_LOCK(kq); 2540 KASSERT(kn_in_flux(kn), ("knote removed w/o list lock")); 2541 knl->kl_unlock(knl->kl_lockarg); 2542 kq->kq_state |= KQ_FLUXWAIT; 2543 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0); 2544 kq = NULL; 2545 goto again; 2546 } 2547 2548 if (islocked) 2549 KNL_ASSERT_LOCKED(knl); 2550 else { 2551 knl->kl_unlock(knl->kl_lockarg); 2552 KNL_ASSERT_UNLOCKED(knl); 2553 } 2554 } 2555 2556 /* 2557 * Remove all knotes referencing a specified fd must be called with FILEDESC 2558 * lock. This prevents a race where a new fd comes along and occupies the 2559 * entry and we attach a knote to the fd. 2560 */ 2561 void 2562 knote_fdclose(struct thread *td, int fd) 2563 { 2564 struct filedesc *fdp = td->td_proc->p_fd; 2565 struct kqueue *kq; 2566 struct knote *kn; 2567 int influx; 2568 2569 FILEDESC_XLOCK_ASSERT(fdp); 2570 2571 /* 2572 * We shouldn't have to worry about new kevents appearing on fd 2573 * since filedesc is locked. 2574 */ 2575 TAILQ_FOREACH(kq, &fdp->fd_kqlist, kq_list) { 2576 KQ_LOCK(kq); 2577 2578 again: 2579 influx = 0; 2580 while (kq->kq_knlistsize > fd && 2581 (kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) { 2582 if (kn_in_flux(kn)) { 2583 /* someone else might be waiting on our knote */ 2584 if (influx) 2585 wakeup(kq); 2586 kq->kq_state |= KQ_FLUXWAIT; 2587 msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0); 2588 goto again; 2589 } 2590 kn_enter_flux(kn); 2591 KQ_UNLOCK(kq); 2592 influx = 1; 2593 knote_drop(kn, td); 2594 KQ_LOCK(kq); 2595 } 2596 KQ_UNLOCK_FLUX(kq); 2597 } 2598 } 2599 2600 static int 2601 knote_attach(struct knote *kn, struct kqueue *kq) 2602 { 2603 struct klist *list; 2604 2605 KASSERT(kn_in_flux(kn), ("knote %p not marked influx", kn)); 2606 KQ_OWNED(kq); 2607 2608 if ((kq->kq_state & KQ_CLOSING) != 0) 2609 return (EBADF); 2610 if (kn->kn_fop->f_isfd) { 2611 if (kn->kn_id >= kq->kq_knlistsize) 2612 return (ENOMEM); 2613 list = &kq->kq_knlist[kn->kn_id]; 2614 } else { 2615 if (kq->kq_knhash == NULL) 2616 return (ENOMEM); 2617 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2618 } 2619 SLIST_INSERT_HEAD(list, kn, kn_link); 2620 return (0); 2621 } 2622 2623 static void 2624 knote_drop(struct knote *kn, struct thread *td) 2625 { 2626 2627 if ((kn->kn_status & KN_DETACHED) == 0) 2628 kn->kn_fop->f_detach(kn); 2629 knote_drop_detached(kn, td); 2630 } 2631 2632 static void 2633 knote_drop_detached(struct knote *kn, struct thread *td) 2634 { 2635 struct kqueue *kq; 2636 struct klist *list; 2637 2638 kq = kn->kn_kq; 2639 2640 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2641 ("knote %p still attached", kn)); 2642 KQ_NOTOWNED(kq); 2643 2644 KQ_LOCK(kq); 2645 KASSERT(kn->kn_influx == 1, 2646 ("knote_drop called on %p with influx %d", kn, kn->kn_influx)); 2647 2648 if (kn->kn_fop->f_isfd) 2649 list = &kq->kq_knlist[kn->kn_id]; 2650 else 2651 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2652 2653 if (!SLIST_EMPTY(list)) 2654 SLIST_REMOVE(list, kn, knote, kn_link); 2655 if (kn->kn_status & KN_QUEUED) 2656 knote_dequeue(kn); 2657 KQ_UNLOCK_FLUX(kq); 2658 2659 if (kn->kn_fop->f_isfd) { 2660 fdrop(kn->kn_fp, td); 2661 kn->kn_fp = NULL; 2662 } 2663 kqueue_fo_release(kn->kn_kevent.filter); 2664 kn->kn_fop = NULL; 2665 knote_free(kn); 2666 } 2667 2668 static void 2669 knote_enqueue(struct knote *kn) 2670 { 2671 struct kqueue *kq = kn->kn_kq; 2672 2673 KQ_OWNED(kn->kn_kq); 2674 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 2675 2676 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2677 kn->kn_status |= KN_QUEUED; 2678 kq->kq_count++; 2679 kqueue_wakeup(kq); 2680 } 2681 2682 static void 2683 knote_dequeue(struct knote *kn) 2684 { 2685 struct kqueue *kq = kn->kn_kq; 2686 2687 KQ_OWNED(kn->kn_kq); 2688 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 2689 2690 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 2691 kn->kn_status &= ~KN_QUEUED; 2692 kq->kq_count--; 2693 } 2694 2695 static void 2696 knote_init(void) 2697 { 2698 2699 knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL, 2700 NULL, NULL, UMA_ALIGN_PTR, 0); 2701 } 2702 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL); 2703 2704 static struct knote * 2705 knote_alloc(int waitok) 2706 { 2707 2708 return (uma_zalloc(knote_zone, (waitok ? M_WAITOK : M_NOWAIT) | 2709 M_ZERO)); 2710 } 2711 2712 static void 2713 knote_free(struct knote *kn) 2714 { 2715 2716 uma_zfree(knote_zone, kn); 2717 } 2718 2719 /* 2720 * Register the kev w/ the kq specified by fd. 2721 */ 2722 int 2723 kqfd_register(int fd, struct kevent *kev, struct thread *td, int waitok) 2724 { 2725 struct kqueue *kq; 2726 struct file *fp; 2727 cap_rights_t rights; 2728 int error; 2729 2730 error = fget(td, fd, cap_rights_init(&rights, CAP_KQUEUE_CHANGE), &fp); 2731 if (error != 0) 2732 return (error); 2733 if ((error = kqueue_acquire(fp, &kq)) != 0) 2734 goto noacquire; 2735 2736 error = kqueue_register(kq, kev, td, waitok); 2737 kqueue_release(kq, 0); 2738 2739 noacquire: 2740 fdrop(fp, td); 2741 return (error); 2742 } 2743