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; 538 539 memset(&kev, 0, sizeof(kev)); 540 list->kl_lock(list->kl_lockarg); 541 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { 542 kq = kn->kn_kq; 543 KQ_LOCK(kq); 544 if (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0) { 545 KQ_UNLOCK(kq); 546 continue; 547 } 548 549 /* 550 * The same as knote(), activate the event. 551 */ 552 if ((kn->kn_sfflags & NOTE_TRACK) == 0) { 553 if (kn->kn_fop->f_event(kn, NOTE_FORK)) 554 KNOTE_ACTIVATE(kn, 1); 555 KQ_UNLOCK(kq); 556 continue; 557 } 558 559 /* 560 * The NOTE_TRACK case. In addition to the activation 561 * of the event, we need to register new events to 562 * track the child. Drop the locks in preparation for 563 * the call to kqueue_register(). 564 */ 565 kn_enter_flux(kn); 566 KQ_UNLOCK(kq); 567 list->kl_unlock(list->kl_lockarg); 568 569 /* 570 * Activate existing knote and register tracking knotes with 571 * new process. 572 * 573 * First register a knote to get just the child notice. This 574 * must be a separate note from a potential NOTE_EXIT 575 * notification since both NOTE_CHILD and NOTE_EXIT are defined 576 * to use the data field (in conflicting ways). 577 */ 578 kev.ident = pid; 579 kev.filter = kn->kn_filter; 580 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_ONESHOT | 581 EV_FLAG2; 582 kev.fflags = kn->kn_sfflags; 583 kev.data = kn->kn_id; /* parent */ 584 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 585 error = kqueue_register(kq, &kev, NULL, 0); 586 if (error) 587 kn->kn_fflags |= NOTE_TRACKERR; 588 589 /* 590 * Then register another knote to track other potential events 591 * from the new process. 592 */ 593 kev.ident = pid; 594 kev.filter = kn->kn_filter; 595 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 596 kev.fflags = kn->kn_sfflags; 597 kev.data = kn->kn_id; /* parent */ 598 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 599 error = kqueue_register(kq, &kev, NULL, 0); 600 if (error) 601 kn->kn_fflags |= NOTE_TRACKERR; 602 if (kn->kn_fop->f_event(kn, NOTE_FORK)) 603 KNOTE_ACTIVATE(kn, 0); 604 list->kl_lock(list->kl_lockarg); 605 KQ_LOCK(kq); 606 kn_leave_flux(kn); 607 KQ_UNLOCK_FLUX(kq); 608 } 609 list->kl_unlock(list->kl_lockarg); 610 } 611 612 /* 613 * XXX: EVFILT_TIMER should perhaps live in kern_time.c beside the 614 * interval timer support code. 615 */ 616 617 #define NOTE_TIMER_PRECMASK \ 618 (NOTE_SECONDS | NOTE_MSECONDS | NOTE_USECONDS | NOTE_NSECONDS) 619 620 static sbintime_t 621 timer2sbintime(intptr_t data, int flags) 622 { 623 int64_t secs; 624 625 /* 626 * Macros for converting to the fractional second portion of an 627 * sbintime_t using 64bit multiplication to improve precision. 628 */ 629 #define NS_TO_SBT(ns) (((ns) * (((uint64_t)1 << 63) / 500000000)) >> 32) 630 #define US_TO_SBT(us) (((us) * (((uint64_t)1 << 63) / 500000)) >> 32) 631 #define MS_TO_SBT(ms) (((ms) * (((uint64_t)1 << 63) / 500)) >> 32) 632 switch (flags & NOTE_TIMER_PRECMASK) { 633 case NOTE_SECONDS: 634 #ifdef __LP64__ 635 if (data > (SBT_MAX / SBT_1S)) 636 return (SBT_MAX); 637 #endif 638 return ((sbintime_t)data << 32); 639 case NOTE_MSECONDS: /* FALLTHROUGH */ 640 case 0: 641 if (data >= 1000) { 642 secs = data / 1000; 643 #ifdef __LP64__ 644 if (secs > (SBT_MAX / SBT_1S)) 645 return (SBT_MAX); 646 #endif 647 return (secs << 32 | MS_TO_SBT(data % 1000)); 648 } 649 return (MS_TO_SBT(data)); 650 case NOTE_USECONDS: 651 if (data >= 1000000) { 652 secs = data / 1000000; 653 #ifdef __LP64__ 654 if (secs > (SBT_MAX / SBT_1S)) 655 return (SBT_MAX); 656 #endif 657 return (secs << 32 | US_TO_SBT(data % 1000000)); 658 } 659 return (US_TO_SBT(data)); 660 case NOTE_NSECONDS: 661 if (data >= 1000000000) { 662 secs = data / 1000000000; 663 #ifdef __LP64__ 664 if (secs > (SBT_MAX / SBT_1S)) 665 return (SBT_MAX); 666 #endif 667 return (secs << 32 | US_TO_SBT(data % 1000000000)); 668 } 669 return (NS_TO_SBT(data)); 670 default: 671 break; 672 } 673 return (-1); 674 } 675 676 struct kq_timer_cb_data { 677 struct callout c; 678 sbintime_t next; /* next timer event fires at */ 679 sbintime_t to; /* precalculated timer period, 0 for abs */ 680 }; 681 682 static void 683 filt_timerexpire(void *knx) 684 { 685 struct knote *kn; 686 struct kq_timer_cb_data *kc; 687 688 kn = knx; 689 kn->kn_data++; 690 KNOTE_ACTIVATE(kn, 0); /* XXX - handle locking */ 691 692 if ((kn->kn_flags & EV_ONESHOT) != 0) 693 return; 694 kc = kn->kn_ptr.p_v; 695 if (kc->to == 0) 696 return; 697 kc->next += kc->to; 698 callout_reset_sbt_on(&kc->c, kc->next, 0, filt_timerexpire, kn, 699 PCPU_GET(cpuid), C_ABSOLUTE); 700 } 701 702 /* 703 * data contains amount of time to sleep 704 */ 705 static int 706 filt_timervalidate(struct knote *kn, sbintime_t *to) 707 { 708 struct bintime bt; 709 sbintime_t sbt; 710 711 if (kn->kn_sdata < 0) 712 return (EINVAL); 713 if (kn->kn_sdata == 0 && (kn->kn_flags & EV_ONESHOT) == 0) 714 kn->kn_sdata = 1; 715 /* 716 * The only fflags values supported are the timer unit 717 * (precision) and the absolute time indicator. 718 */ 719 if ((kn->kn_sfflags & ~(NOTE_TIMER_PRECMASK | NOTE_ABSTIME)) != 0) 720 return (EINVAL); 721 722 *to = timer2sbintime(kn->kn_sdata, kn->kn_sfflags); 723 if ((kn->kn_sfflags & NOTE_ABSTIME) != 0) { 724 getboottimebin(&bt); 725 sbt = bttosbt(bt); 726 *to -= sbt; 727 } 728 if (*to < 0) 729 return (EINVAL); 730 return (0); 731 } 732 733 static int 734 filt_timerattach(struct knote *kn) 735 { 736 struct kq_timer_cb_data *kc; 737 sbintime_t to; 738 unsigned int ncallouts; 739 int error; 740 741 error = filt_timervalidate(kn, &to); 742 if (error != 0) 743 return (error); 744 745 do { 746 ncallouts = kq_ncallouts; 747 if (ncallouts >= kq_calloutmax) 748 return (ENOMEM); 749 } while (!atomic_cmpset_int(&kq_ncallouts, ncallouts, ncallouts + 1)); 750 751 if ((kn->kn_sfflags & NOTE_ABSTIME) == 0) 752 kn->kn_flags |= EV_CLEAR; /* automatically set */ 753 kn->kn_status &= ~KN_DETACHED; /* knlist_add clears it */ 754 kn->kn_ptr.p_v = kc = malloc(sizeof(*kc), M_KQUEUE, M_WAITOK); 755 callout_init(&kc->c, 1); 756 filt_timerstart(kn, to); 757 758 return (0); 759 } 760 761 static void 762 filt_timerstart(struct knote *kn, sbintime_t to) 763 { 764 struct kq_timer_cb_data *kc; 765 766 kc = kn->kn_ptr.p_v; 767 if ((kn->kn_sfflags & NOTE_ABSTIME) != 0) { 768 kc->next = to; 769 kc->to = 0; 770 } else { 771 kc->next = to + sbinuptime(); 772 kc->to = to; 773 } 774 callout_reset_sbt_on(&kc->c, kc->next, 0, filt_timerexpire, kn, 775 PCPU_GET(cpuid), C_ABSOLUTE); 776 } 777 778 static void 779 filt_timerdetach(struct knote *kn) 780 { 781 struct kq_timer_cb_data *kc; 782 unsigned int old __unused; 783 784 kc = kn->kn_ptr.p_v; 785 callout_drain(&kc->c); 786 free(kc, M_KQUEUE); 787 old = atomic_fetchadd_int(&kq_ncallouts, -1); 788 KASSERT(old > 0, ("Number of callouts cannot become negative")); 789 kn->kn_status |= KN_DETACHED; /* knlist_remove sets it */ 790 } 791 792 static void 793 filt_timertouch(struct knote *kn, struct kevent *kev, u_long type) 794 { 795 struct kq_timer_cb_data *kc; 796 struct kqueue *kq; 797 sbintime_t to; 798 int error; 799 800 switch (type) { 801 case EVENT_REGISTER: 802 /* Handle re-added timers that update data/fflags */ 803 if (kev->flags & EV_ADD) { 804 kc = kn->kn_ptr.p_v; 805 806 /* Drain any existing callout. */ 807 callout_drain(&kc->c); 808 809 /* Throw away any existing undelivered record 810 * of the timer expiration. This is done under 811 * the presumption that if a process is 812 * re-adding this timer with new parameters, 813 * it is no longer interested in what may have 814 * happened under the old parameters. If it is 815 * interested, it can wait for the expiration, 816 * delete the old timer definition, and then 817 * add the new one. 818 * 819 * This has to be done while the kq is locked: 820 * - if enqueued, dequeue 821 * - make it no longer active 822 * - clear the count of expiration events 823 */ 824 kq = kn->kn_kq; 825 KQ_LOCK(kq); 826 if (kn->kn_status & KN_QUEUED) 827 knote_dequeue(kn); 828 829 kn->kn_status &= ~KN_ACTIVE; 830 kn->kn_data = 0; 831 KQ_UNLOCK(kq); 832 833 /* Reschedule timer based on new data/fflags */ 834 kn->kn_sfflags = kev->fflags; 835 kn->kn_sdata = kev->data; 836 error = filt_timervalidate(kn, &to); 837 if (error != 0) { 838 kn->kn_flags |= EV_ERROR; 839 kn->kn_data = error; 840 } else 841 filt_timerstart(kn, to); 842 } 843 break; 844 845 case EVENT_PROCESS: 846 *kev = kn->kn_kevent; 847 if (kn->kn_flags & EV_CLEAR) { 848 kn->kn_data = 0; 849 kn->kn_fflags = 0; 850 } 851 break; 852 853 default: 854 panic("filt_timertouch() - invalid type (%ld)", type); 855 break; 856 } 857 } 858 859 static int 860 filt_timer(struct knote *kn, long hint) 861 { 862 863 return (kn->kn_data != 0); 864 } 865 866 static int 867 filt_userattach(struct knote *kn) 868 { 869 870 /* 871 * EVFILT_USER knotes are not attached to anything in the kernel. 872 */ 873 kn->kn_hook = NULL; 874 if (kn->kn_fflags & NOTE_TRIGGER) 875 kn->kn_hookid = 1; 876 else 877 kn->kn_hookid = 0; 878 return (0); 879 } 880 881 static void 882 filt_userdetach(__unused struct knote *kn) 883 { 884 885 /* 886 * EVFILT_USER knotes are not attached to anything in the kernel. 887 */ 888 } 889 890 static int 891 filt_user(struct knote *kn, __unused long hint) 892 { 893 894 return (kn->kn_hookid); 895 } 896 897 static void 898 filt_usertouch(struct knote *kn, struct kevent *kev, u_long type) 899 { 900 u_int ffctrl; 901 902 switch (type) { 903 case EVENT_REGISTER: 904 if (kev->fflags & NOTE_TRIGGER) 905 kn->kn_hookid = 1; 906 907 ffctrl = kev->fflags & NOTE_FFCTRLMASK; 908 kev->fflags &= NOTE_FFLAGSMASK; 909 switch (ffctrl) { 910 case NOTE_FFNOP: 911 break; 912 913 case NOTE_FFAND: 914 kn->kn_sfflags &= kev->fflags; 915 break; 916 917 case NOTE_FFOR: 918 kn->kn_sfflags |= kev->fflags; 919 break; 920 921 case NOTE_FFCOPY: 922 kn->kn_sfflags = kev->fflags; 923 break; 924 925 default: 926 /* XXX Return error? */ 927 break; 928 } 929 kn->kn_sdata = kev->data; 930 if (kev->flags & EV_CLEAR) { 931 kn->kn_hookid = 0; 932 kn->kn_data = 0; 933 kn->kn_fflags = 0; 934 } 935 break; 936 937 case EVENT_PROCESS: 938 *kev = kn->kn_kevent; 939 kev->fflags = kn->kn_sfflags; 940 kev->data = kn->kn_sdata; 941 if (kn->kn_flags & EV_CLEAR) { 942 kn->kn_hookid = 0; 943 kn->kn_data = 0; 944 kn->kn_fflags = 0; 945 } 946 break; 947 948 default: 949 panic("filt_usertouch() - invalid type (%ld)", type); 950 break; 951 } 952 } 953 954 int 955 sys_kqueue(struct thread *td, struct kqueue_args *uap) 956 { 957 958 return (kern_kqueue(td, 0, NULL)); 959 } 960 961 static void 962 kqueue_init(struct kqueue *kq) 963 { 964 965 mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF | MTX_DUPOK); 966 TAILQ_INIT(&kq->kq_head); 967 knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock); 968 TASK_INIT(&kq->kq_task, 0, kqueue_task, kq); 969 } 970 971 int 972 kern_kqueue(struct thread *td, int flags, struct filecaps *fcaps) 973 { 974 struct filedesc *fdp; 975 struct kqueue *kq; 976 struct file *fp; 977 struct ucred *cred; 978 int fd, error; 979 980 fdp = td->td_proc->p_fd; 981 cred = td->td_ucred; 982 if (!chgkqcnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_KQUEUES))) 983 return (ENOMEM); 984 985 error = falloc_caps(td, &fp, &fd, flags, fcaps); 986 if (error != 0) { 987 chgkqcnt(cred->cr_ruidinfo, -1, 0); 988 return (error); 989 } 990 991 /* An extra reference on `fp' has been held for us by falloc(). */ 992 kq = malloc(sizeof *kq, M_KQUEUE, M_WAITOK | M_ZERO); 993 kqueue_init(kq); 994 kq->kq_fdp = fdp; 995 kq->kq_cred = crhold(cred); 996 997 FILEDESC_XLOCK(fdp); 998 TAILQ_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list); 999 FILEDESC_XUNLOCK(fdp); 1000 1001 finit(fp, FREAD | FWRITE, DTYPE_KQUEUE, kq, &kqueueops); 1002 fdrop(fp, td); 1003 1004 td->td_retval[0] = fd; 1005 return (0); 1006 } 1007 1008 struct g_kevent_args { 1009 int fd; 1010 void *changelist; 1011 int nchanges; 1012 void *eventlist; 1013 int nevents; 1014 const struct timespec *timeout; 1015 }; 1016 1017 int 1018 sys_kevent(struct thread *td, struct kevent_args *uap) 1019 { 1020 struct kevent_copyops k_ops = { 1021 .arg = uap, 1022 .k_copyout = kevent_copyout, 1023 .k_copyin = kevent_copyin, 1024 .kevent_size = sizeof(struct kevent), 1025 }; 1026 struct g_kevent_args gk_args = { 1027 .fd = uap->fd, 1028 .changelist = uap->changelist, 1029 .nchanges = uap->nchanges, 1030 .eventlist = uap->eventlist, 1031 .nevents = uap->nevents, 1032 .timeout = uap->timeout, 1033 }; 1034 1035 return (kern_kevent_generic(td, &gk_args, &k_ops, "kevent")); 1036 } 1037 1038 static int 1039 kern_kevent_generic(struct thread *td, struct g_kevent_args *uap, 1040 struct kevent_copyops *k_ops, const char *struct_name) 1041 { 1042 struct timespec ts, *tsp; 1043 #ifdef KTRACE 1044 struct kevent *eventlist = uap->eventlist; 1045 #endif 1046 int error; 1047 1048 if (uap->timeout != NULL) { 1049 error = copyin(uap->timeout, &ts, sizeof(ts)); 1050 if (error) 1051 return (error); 1052 tsp = &ts; 1053 } else 1054 tsp = NULL; 1055 1056 #ifdef KTRACE 1057 if (KTRPOINT(td, KTR_STRUCT_ARRAY)) 1058 ktrstructarray(struct_name, UIO_USERSPACE, uap->changelist, 1059 uap->nchanges, k_ops->kevent_size); 1060 #endif 1061 1062 error = kern_kevent(td, uap->fd, uap->nchanges, uap->nevents, 1063 k_ops, tsp); 1064 1065 #ifdef KTRACE 1066 if (error == 0 && KTRPOINT(td, KTR_STRUCT_ARRAY)) 1067 ktrstructarray(struct_name, UIO_USERSPACE, eventlist, 1068 td->td_retval[0], k_ops->kevent_size); 1069 #endif 1070 1071 return (error); 1072 } 1073 1074 /* 1075 * Copy 'count' items into the destination list pointed to by uap->eventlist. 1076 */ 1077 static int 1078 kevent_copyout(void *arg, struct kevent *kevp, int count) 1079 { 1080 struct kevent_args *uap; 1081 int error; 1082 1083 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1084 uap = (struct kevent_args *)arg; 1085 1086 error = copyout(kevp, uap->eventlist, count * sizeof *kevp); 1087 if (error == 0) 1088 uap->eventlist += count; 1089 return (error); 1090 } 1091 1092 /* 1093 * Copy 'count' items from the list pointed to by uap->changelist. 1094 */ 1095 static int 1096 kevent_copyin(void *arg, struct kevent *kevp, int count) 1097 { 1098 struct kevent_args *uap; 1099 int error; 1100 1101 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1102 uap = (struct kevent_args *)arg; 1103 1104 error = copyin(uap->changelist, kevp, count * sizeof *kevp); 1105 if (error == 0) 1106 uap->changelist += count; 1107 return (error); 1108 } 1109 1110 #ifdef COMPAT_FREEBSD11 1111 static int 1112 kevent11_copyout(void *arg, struct kevent *kevp, int count) 1113 { 1114 struct freebsd11_kevent_args *uap; 1115 struct kevent_freebsd11 kev11; 1116 int error, i; 1117 1118 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1119 uap = (struct freebsd11_kevent_args *)arg; 1120 1121 for (i = 0; i < count; i++) { 1122 kev11.ident = kevp->ident; 1123 kev11.filter = kevp->filter; 1124 kev11.flags = kevp->flags; 1125 kev11.fflags = kevp->fflags; 1126 kev11.data = kevp->data; 1127 kev11.udata = kevp->udata; 1128 error = copyout(&kev11, uap->eventlist, sizeof(kev11)); 1129 if (error != 0) 1130 break; 1131 uap->eventlist++; 1132 kevp++; 1133 } 1134 return (error); 1135 } 1136 1137 /* 1138 * Copy 'count' items from the list pointed to by uap->changelist. 1139 */ 1140 static int 1141 kevent11_copyin(void *arg, struct kevent *kevp, int count) 1142 { 1143 struct freebsd11_kevent_args *uap; 1144 struct kevent_freebsd11 kev11; 1145 int error, i; 1146 1147 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1148 uap = (struct freebsd11_kevent_args *)arg; 1149 1150 for (i = 0; i < count; i++) { 1151 error = copyin(uap->changelist, &kev11, sizeof(kev11)); 1152 if (error != 0) 1153 break; 1154 kevp->ident = kev11.ident; 1155 kevp->filter = kev11.filter; 1156 kevp->flags = kev11.flags; 1157 kevp->fflags = kev11.fflags; 1158 kevp->data = (uintptr_t)kev11.data; 1159 kevp->udata = kev11.udata; 1160 bzero(&kevp->ext, sizeof(kevp->ext)); 1161 uap->changelist++; 1162 kevp++; 1163 } 1164 return (error); 1165 } 1166 1167 int 1168 freebsd11_kevent(struct thread *td, struct freebsd11_kevent_args *uap) 1169 { 1170 struct kevent_copyops k_ops = { 1171 .arg = uap, 1172 .k_copyout = kevent11_copyout, 1173 .k_copyin = kevent11_copyin, 1174 .kevent_size = sizeof(struct kevent_freebsd11), 1175 }; 1176 struct g_kevent_args gk_args = { 1177 .fd = uap->fd, 1178 .changelist = uap->changelist, 1179 .nchanges = uap->nchanges, 1180 .eventlist = uap->eventlist, 1181 .nevents = uap->nevents, 1182 .timeout = uap->timeout, 1183 }; 1184 1185 return (kern_kevent_generic(td, &gk_args, &k_ops, "kevent_freebsd11")); 1186 } 1187 #endif 1188 1189 int 1190 kern_kevent(struct thread *td, int fd, int nchanges, int nevents, 1191 struct kevent_copyops *k_ops, const struct timespec *timeout) 1192 { 1193 cap_rights_t rights; 1194 struct file *fp; 1195 int error; 1196 1197 cap_rights_init(&rights); 1198 if (nchanges > 0) 1199 cap_rights_set(&rights, CAP_KQUEUE_CHANGE); 1200 if (nevents > 0) 1201 cap_rights_set(&rights, CAP_KQUEUE_EVENT); 1202 error = fget(td, fd, &rights, &fp); 1203 if (error != 0) 1204 return (error); 1205 1206 error = kern_kevent_fp(td, fp, nchanges, nevents, k_ops, timeout); 1207 fdrop(fp, td); 1208 1209 return (error); 1210 } 1211 1212 static int 1213 kqueue_kevent(struct kqueue *kq, struct thread *td, int nchanges, int nevents, 1214 struct kevent_copyops *k_ops, const struct timespec *timeout) 1215 { 1216 struct kevent keva[KQ_NEVENTS]; 1217 struct kevent *kevp, *changes; 1218 int i, n, nerrors, error; 1219 1220 nerrors = 0; 1221 while (nchanges > 0) { 1222 n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges; 1223 error = k_ops->k_copyin(k_ops->arg, keva, n); 1224 if (error) 1225 return (error); 1226 changes = keva; 1227 for (i = 0; i < n; i++) { 1228 kevp = &changes[i]; 1229 if (!kevp->filter) 1230 continue; 1231 kevp->flags &= ~EV_SYSFLAGS; 1232 error = kqueue_register(kq, kevp, td, 1); 1233 if (error || (kevp->flags & EV_RECEIPT)) { 1234 if (nevents == 0) 1235 return (error); 1236 kevp->flags = EV_ERROR; 1237 kevp->data = error; 1238 (void)k_ops->k_copyout(k_ops->arg, kevp, 1); 1239 nevents--; 1240 nerrors++; 1241 } 1242 } 1243 nchanges -= n; 1244 } 1245 if (nerrors) { 1246 td->td_retval[0] = nerrors; 1247 return (0); 1248 } 1249 1250 return (kqueue_scan(kq, nevents, k_ops, timeout, keva, td)); 1251 } 1252 1253 int 1254 kern_kevent_fp(struct thread *td, struct file *fp, int nchanges, int nevents, 1255 struct kevent_copyops *k_ops, const struct timespec *timeout) 1256 { 1257 struct kqueue *kq; 1258 int error; 1259 1260 error = kqueue_acquire(fp, &kq); 1261 if (error != 0) 1262 return (error); 1263 error = kqueue_kevent(kq, td, nchanges, nevents, k_ops, timeout); 1264 kqueue_release(kq, 0); 1265 return (error); 1266 } 1267 1268 /* 1269 * Performs a kevent() call on a temporarily created kqueue. This can be 1270 * used to perform one-shot polling, similar to poll() and select(). 1271 */ 1272 int 1273 kern_kevent_anonymous(struct thread *td, int nevents, 1274 struct kevent_copyops *k_ops) 1275 { 1276 struct kqueue kq = {}; 1277 int error; 1278 1279 kqueue_init(&kq); 1280 kq.kq_refcnt = 1; 1281 error = kqueue_kevent(&kq, td, nevents, nevents, k_ops, NULL); 1282 kqueue_drain(&kq, td); 1283 kqueue_destroy(&kq); 1284 return (error); 1285 } 1286 1287 int 1288 kqueue_add_filteropts(int filt, struct filterops *filtops) 1289 { 1290 int error; 1291 1292 error = 0; 1293 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) { 1294 printf( 1295 "trying to add a filterop that is out of range: %d is beyond %d\n", 1296 ~filt, EVFILT_SYSCOUNT); 1297 return EINVAL; 1298 } 1299 mtx_lock(&filterops_lock); 1300 if (sysfilt_ops[~filt].for_fop != &null_filtops && 1301 sysfilt_ops[~filt].for_fop != NULL) 1302 error = EEXIST; 1303 else { 1304 sysfilt_ops[~filt].for_fop = filtops; 1305 sysfilt_ops[~filt].for_refcnt = 0; 1306 } 1307 mtx_unlock(&filterops_lock); 1308 1309 return (error); 1310 } 1311 1312 int 1313 kqueue_del_filteropts(int filt) 1314 { 1315 int error; 1316 1317 error = 0; 1318 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1319 return EINVAL; 1320 1321 mtx_lock(&filterops_lock); 1322 if (sysfilt_ops[~filt].for_fop == &null_filtops || 1323 sysfilt_ops[~filt].for_fop == NULL) 1324 error = EINVAL; 1325 else if (sysfilt_ops[~filt].for_refcnt != 0) 1326 error = EBUSY; 1327 else { 1328 sysfilt_ops[~filt].for_fop = &null_filtops; 1329 sysfilt_ops[~filt].for_refcnt = 0; 1330 } 1331 mtx_unlock(&filterops_lock); 1332 1333 return error; 1334 } 1335 1336 static struct filterops * 1337 kqueue_fo_find(int filt) 1338 { 1339 1340 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1341 return NULL; 1342 1343 if (sysfilt_ops[~filt].for_nolock) 1344 return sysfilt_ops[~filt].for_fop; 1345 1346 mtx_lock(&filterops_lock); 1347 sysfilt_ops[~filt].for_refcnt++; 1348 if (sysfilt_ops[~filt].for_fop == NULL) 1349 sysfilt_ops[~filt].for_fop = &null_filtops; 1350 mtx_unlock(&filterops_lock); 1351 1352 return sysfilt_ops[~filt].for_fop; 1353 } 1354 1355 static void 1356 kqueue_fo_release(int filt) 1357 { 1358 1359 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1360 return; 1361 1362 if (sysfilt_ops[~filt].for_nolock) 1363 return; 1364 1365 mtx_lock(&filterops_lock); 1366 KASSERT(sysfilt_ops[~filt].for_refcnt > 0, 1367 ("filter object refcount not valid on release")); 1368 sysfilt_ops[~filt].for_refcnt--; 1369 mtx_unlock(&filterops_lock); 1370 } 1371 1372 /* 1373 * A ref to kq (obtained via kqueue_acquire) must be held. waitok will 1374 * influence if memory allocation should wait. Make sure it is 0 if you 1375 * hold any mutexes. 1376 */ 1377 static int 1378 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, int waitok) 1379 { 1380 struct filterops *fops; 1381 struct file *fp; 1382 struct knote *kn, *tkn; 1383 struct knlist *knl; 1384 int error, filt, event; 1385 int haskqglobal, filedesc_unlock; 1386 1387 if ((kev->flags & (EV_ENABLE | EV_DISABLE)) == (EV_ENABLE | EV_DISABLE)) 1388 return (EINVAL); 1389 1390 fp = NULL; 1391 kn = NULL; 1392 knl = NULL; 1393 error = 0; 1394 haskqglobal = 0; 1395 filedesc_unlock = 0; 1396 1397 filt = kev->filter; 1398 fops = kqueue_fo_find(filt); 1399 if (fops == NULL) 1400 return EINVAL; 1401 1402 if (kev->flags & EV_ADD) { 1403 /* 1404 * Prevent waiting with locks. Non-sleepable 1405 * allocation failures are handled in the loop, only 1406 * if the spare knote appears to be actually required. 1407 */ 1408 tkn = knote_alloc(waitok); 1409 } else { 1410 tkn = NULL; 1411 } 1412 1413 findkn: 1414 if (fops->f_isfd) { 1415 KASSERT(td != NULL, ("td is NULL")); 1416 if (kev->ident > INT_MAX) 1417 error = EBADF; 1418 else 1419 error = fget(td, kev->ident, &cap_event_rights, &fp); 1420 if (error) 1421 goto done; 1422 1423 if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops, 1424 kev->ident, 0) != 0) { 1425 /* try again */ 1426 fdrop(fp, td); 1427 fp = NULL; 1428 error = kqueue_expand(kq, fops, kev->ident, waitok); 1429 if (error) 1430 goto done; 1431 goto findkn; 1432 } 1433 1434 if (fp->f_type == DTYPE_KQUEUE) { 1435 /* 1436 * If we add some intelligence about what we are doing, 1437 * we should be able to support events on ourselves. 1438 * We need to know when we are doing this to prevent 1439 * getting both the knlist lock and the kq lock since 1440 * they are the same thing. 1441 */ 1442 if (fp->f_data == kq) { 1443 error = EINVAL; 1444 goto done; 1445 } 1446 1447 /* 1448 * Pre-lock the filedesc before the global 1449 * lock mutex, see the comment in 1450 * kqueue_close(). 1451 */ 1452 FILEDESC_XLOCK(td->td_proc->p_fd); 1453 filedesc_unlock = 1; 1454 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1455 } 1456 1457 KQ_LOCK(kq); 1458 if (kev->ident < kq->kq_knlistsize) { 1459 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link) 1460 if (kev->filter == kn->kn_filter) 1461 break; 1462 } 1463 } else { 1464 if ((kev->flags & EV_ADD) == EV_ADD) { 1465 error = kqueue_expand(kq, fops, kev->ident, waitok); 1466 if (error != 0) 1467 goto done; 1468 } 1469 1470 KQ_LOCK(kq); 1471 1472 /* 1473 * If possible, find an existing knote to use for this kevent. 1474 */ 1475 if (kev->filter == EVFILT_PROC && 1476 (kev->flags & (EV_FLAG1 | EV_FLAG2)) != 0) { 1477 /* This is an internal creation of a process tracking 1478 * note. Don't attempt to coalesce this with an 1479 * existing note. 1480 */ 1481 ; 1482 } else if (kq->kq_knhashmask != 0) { 1483 struct klist *list; 1484 1485 list = &kq->kq_knhash[ 1486 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)]; 1487 SLIST_FOREACH(kn, list, kn_link) 1488 if (kev->ident == kn->kn_id && 1489 kev->filter == kn->kn_filter) 1490 break; 1491 } 1492 } 1493 1494 /* knote is in the process of changing, wait for it to stabilize. */ 1495 if (kn != NULL && kn_in_flux(kn)) { 1496 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1497 if (filedesc_unlock) { 1498 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1499 filedesc_unlock = 0; 1500 } 1501 kq->kq_state |= KQ_FLUXWAIT; 1502 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0); 1503 if (fp != NULL) { 1504 fdrop(fp, td); 1505 fp = NULL; 1506 } 1507 goto findkn; 1508 } 1509 1510 /* 1511 * kn now contains the matching knote, or NULL if no match 1512 */ 1513 if (kn == NULL) { 1514 if (kev->flags & EV_ADD) { 1515 kn = tkn; 1516 tkn = NULL; 1517 if (kn == NULL) { 1518 KQ_UNLOCK(kq); 1519 error = ENOMEM; 1520 goto done; 1521 } 1522 kn->kn_fp = fp; 1523 kn->kn_kq = kq; 1524 kn->kn_fop = fops; 1525 /* 1526 * apply reference counts to knote structure, and 1527 * do not release it at the end of this routine. 1528 */ 1529 fops = NULL; 1530 fp = NULL; 1531 1532 kn->kn_sfflags = kev->fflags; 1533 kn->kn_sdata = kev->data; 1534 kev->fflags = 0; 1535 kev->data = 0; 1536 kn->kn_kevent = *kev; 1537 kn->kn_kevent.flags &= ~(EV_ADD | EV_DELETE | 1538 EV_ENABLE | EV_DISABLE | EV_FORCEONESHOT); 1539 kn->kn_status = KN_DETACHED; 1540 if ((kev->flags & EV_DISABLE) != 0) 1541 kn->kn_status |= KN_DISABLED; 1542 kn_enter_flux(kn); 1543 1544 error = knote_attach(kn, kq); 1545 KQ_UNLOCK(kq); 1546 if (error != 0) { 1547 tkn = kn; 1548 goto done; 1549 } 1550 1551 if ((error = kn->kn_fop->f_attach(kn)) != 0) { 1552 knote_drop_detached(kn, td); 1553 goto done; 1554 } 1555 knl = kn_list_lock(kn); 1556 goto done_ev_add; 1557 } else { 1558 /* No matching knote and the EV_ADD flag is not set. */ 1559 KQ_UNLOCK(kq); 1560 error = ENOENT; 1561 goto done; 1562 } 1563 } 1564 1565 if (kev->flags & EV_DELETE) { 1566 kn_enter_flux(kn); 1567 KQ_UNLOCK(kq); 1568 knote_drop(kn, td); 1569 goto done; 1570 } 1571 1572 if (kev->flags & EV_FORCEONESHOT) { 1573 kn->kn_flags |= EV_ONESHOT; 1574 KNOTE_ACTIVATE(kn, 1); 1575 } 1576 1577 if ((kev->flags & EV_ENABLE) != 0) 1578 kn->kn_status &= ~KN_DISABLED; 1579 else if ((kev->flags & EV_DISABLE) != 0) 1580 kn->kn_status |= KN_DISABLED; 1581 1582 /* 1583 * The user may change some filter values after the initial EV_ADD, 1584 * but doing so will not reset any filter which has already been 1585 * triggered. 1586 */ 1587 kn->kn_status |= KN_SCAN; 1588 kn_enter_flux(kn); 1589 KQ_UNLOCK(kq); 1590 knl = kn_list_lock(kn); 1591 kn->kn_kevent.udata = kev->udata; 1592 if (!fops->f_isfd && fops->f_touch != NULL) { 1593 fops->f_touch(kn, kev, EVENT_REGISTER); 1594 } else { 1595 kn->kn_sfflags = kev->fflags; 1596 kn->kn_sdata = kev->data; 1597 } 1598 1599 done_ev_add: 1600 /* 1601 * We can get here with kn->kn_knlist == NULL. This can happen when 1602 * the initial attach event decides that the event is "completed" 1603 * already, e.g., filt_procattach() is called on a zombie process. It 1604 * will call filt_proc() which will remove it from the list, and NULL 1605 * kn_knlist. 1606 * 1607 * KN_DISABLED will be stable while the knote is in flux, so the 1608 * unlocked read will not race with an update. 1609 */ 1610 if ((kn->kn_status & KN_DISABLED) == 0) 1611 event = kn->kn_fop->f_event(kn, 0); 1612 else 1613 event = 0; 1614 1615 KQ_LOCK(kq); 1616 if (event) 1617 kn->kn_status |= KN_ACTIVE; 1618 if ((kn->kn_status & (KN_ACTIVE | KN_DISABLED | KN_QUEUED)) == 1619 KN_ACTIVE) 1620 knote_enqueue(kn); 1621 kn->kn_status &= ~KN_SCAN; 1622 kn_leave_flux(kn); 1623 kn_list_unlock(knl); 1624 KQ_UNLOCK_FLUX(kq); 1625 1626 done: 1627 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1628 if (filedesc_unlock) 1629 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1630 if (fp != NULL) 1631 fdrop(fp, td); 1632 knote_free(tkn); 1633 if (fops != NULL) 1634 kqueue_fo_release(filt); 1635 return (error); 1636 } 1637 1638 static int 1639 kqueue_acquire(struct file *fp, struct kqueue **kqp) 1640 { 1641 int error; 1642 struct kqueue *kq; 1643 1644 error = 0; 1645 1646 kq = fp->f_data; 1647 if (fp->f_type != DTYPE_KQUEUE || kq == NULL) 1648 return (EBADF); 1649 *kqp = kq; 1650 KQ_LOCK(kq); 1651 if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) { 1652 KQ_UNLOCK(kq); 1653 return (EBADF); 1654 } 1655 kq->kq_refcnt++; 1656 KQ_UNLOCK(kq); 1657 1658 return error; 1659 } 1660 1661 static void 1662 kqueue_release(struct kqueue *kq, int locked) 1663 { 1664 if (locked) 1665 KQ_OWNED(kq); 1666 else 1667 KQ_LOCK(kq); 1668 kq->kq_refcnt--; 1669 if (kq->kq_refcnt == 1) 1670 wakeup(&kq->kq_refcnt); 1671 if (!locked) 1672 KQ_UNLOCK(kq); 1673 } 1674 1675 static void 1676 kqueue_schedtask(struct kqueue *kq) 1677 { 1678 1679 KQ_OWNED(kq); 1680 KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN), 1681 ("scheduling kqueue task while draining")); 1682 1683 if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) { 1684 taskqueue_enqueue(taskqueue_kqueue_ctx, &kq->kq_task); 1685 kq->kq_state |= KQ_TASKSCHED; 1686 } 1687 } 1688 1689 /* 1690 * Expand the kq to make sure we have storage for fops/ident pair. 1691 * 1692 * Return 0 on success (or no work necessary), return errno on failure. 1693 */ 1694 static int 1695 kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident, 1696 int waitok) 1697 { 1698 struct klist *list, *tmp_knhash, *to_free; 1699 u_long tmp_knhashmask; 1700 int error, fd, size; 1701 int mflag = waitok ? M_WAITOK : M_NOWAIT; 1702 1703 KQ_NOTOWNED(kq); 1704 1705 error = 0; 1706 to_free = NULL; 1707 if (fops->f_isfd) { 1708 fd = ident; 1709 if (kq->kq_knlistsize <= fd) { 1710 size = kq->kq_knlistsize; 1711 while (size <= fd) 1712 size += KQEXTENT; 1713 list = malloc(size * sizeof(*list), M_KQUEUE, mflag); 1714 if (list == NULL) 1715 return ENOMEM; 1716 KQ_LOCK(kq); 1717 if ((kq->kq_state & KQ_CLOSING) != 0) { 1718 to_free = list; 1719 error = EBADF; 1720 } else if (kq->kq_knlistsize > fd) { 1721 to_free = list; 1722 } else { 1723 if (kq->kq_knlist != NULL) { 1724 bcopy(kq->kq_knlist, list, 1725 kq->kq_knlistsize * sizeof(*list)); 1726 to_free = kq->kq_knlist; 1727 kq->kq_knlist = NULL; 1728 } 1729 bzero((caddr_t)list + 1730 kq->kq_knlistsize * sizeof(*list), 1731 (size - kq->kq_knlistsize) * sizeof(*list)); 1732 kq->kq_knlistsize = size; 1733 kq->kq_knlist = list; 1734 } 1735 KQ_UNLOCK(kq); 1736 } 1737 } else { 1738 if (kq->kq_knhashmask == 0) { 1739 tmp_knhash = hashinit_flags(KN_HASHSIZE, M_KQUEUE, 1740 &tmp_knhashmask, 1741 waitok ? HASH_WAITOK : HASH_NOWAIT); 1742 if (tmp_knhash == NULL) 1743 return (ENOMEM); 1744 KQ_LOCK(kq); 1745 if ((kq->kq_state & KQ_CLOSING) != 0) { 1746 to_free = tmp_knhash; 1747 error = EBADF; 1748 } else if (kq->kq_knhashmask == 0) { 1749 kq->kq_knhash = tmp_knhash; 1750 kq->kq_knhashmask = tmp_knhashmask; 1751 } else { 1752 to_free = tmp_knhash; 1753 } 1754 KQ_UNLOCK(kq); 1755 } 1756 } 1757 free(to_free, M_KQUEUE); 1758 1759 KQ_NOTOWNED(kq); 1760 return (error); 1761 } 1762 1763 static void 1764 kqueue_task(void *arg, int pending) 1765 { 1766 struct kqueue *kq; 1767 int haskqglobal; 1768 1769 haskqglobal = 0; 1770 kq = arg; 1771 1772 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1773 KQ_LOCK(kq); 1774 1775 KNOTE_LOCKED(&kq->kq_sel.si_note, 0); 1776 1777 kq->kq_state &= ~KQ_TASKSCHED; 1778 if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) { 1779 wakeup(&kq->kq_state); 1780 } 1781 KQ_UNLOCK(kq); 1782 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1783 } 1784 1785 /* 1786 * Scan, update kn_data (if not ONESHOT), and copyout triggered events. 1787 * We treat KN_MARKER knotes as if they are in flux. 1788 */ 1789 static int 1790 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops, 1791 const struct timespec *tsp, struct kevent *keva, struct thread *td) 1792 { 1793 struct kevent *kevp; 1794 struct knote *kn, *marker; 1795 struct knlist *knl; 1796 sbintime_t asbt, rsbt; 1797 int count, error, haskqglobal, influx, nkev, touch; 1798 1799 count = maxevents; 1800 nkev = 0; 1801 error = 0; 1802 haskqglobal = 0; 1803 1804 if (maxevents == 0) 1805 goto done_nl; 1806 1807 rsbt = 0; 1808 if (tsp != NULL) { 1809 if (tsp->tv_sec < 0 || tsp->tv_nsec < 0 || 1810 tsp->tv_nsec >= 1000000000) { 1811 error = EINVAL; 1812 goto done_nl; 1813 } 1814 if (timespecisset(tsp)) { 1815 if (tsp->tv_sec <= INT32_MAX) { 1816 rsbt = tstosbt(*tsp); 1817 if (TIMESEL(&asbt, rsbt)) 1818 asbt += tc_tick_sbt; 1819 if (asbt <= SBT_MAX - rsbt) 1820 asbt += rsbt; 1821 else 1822 asbt = 0; 1823 rsbt >>= tc_precexp; 1824 } else 1825 asbt = 0; 1826 } else 1827 asbt = -1; 1828 } else 1829 asbt = 0; 1830 marker = knote_alloc(1); 1831 marker->kn_status = KN_MARKER; 1832 KQ_LOCK(kq); 1833 1834 retry: 1835 kevp = keva; 1836 if (kq->kq_count == 0) { 1837 if (asbt == -1) { 1838 error = EWOULDBLOCK; 1839 } else { 1840 kq->kq_state |= KQ_SLEEP; 1841 error = msleep_sbt(kq, &kq->kq_lock, PSOCK | PCATCH, 1842 "kqread", asbt, rsbt, C_ABSOLUTE); 1843 } 1844 if (error == 0) 1845 goto retry; 1846 /* don't restart after signals... */ 1847 if (error == ERESTART) 1848 error = EINTR; 1849 else if (error == EWOULDBLOCK) 1850 error = 0; 1851 goto done; 1852 } 1853 1854 TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); 1855 influx = 0; 1856 while (count) { 1857 KQ_OWNED(kq); 1858 kn = TAILQ_FIRST(&kq->kq_head); 1859 1860 if ((kn->kn_status == KN_MARKER && kn != marker) || 1861 kn_in_flux(kn)) { 1862 if (influx) { 1863 influx = 0; 1864 KQ_FLUX_WAKEUP(kq); 1865 } 1866 kq->kq_state |= KQ_FLUXWAIT; 1867 error = msleep(kq, &kq->kq_lock, PSOCK, 1868 "kqflxwt", 0); 1869 continue; 1870 } 1871 1872 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1873 if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) { 1874 kn->kn_status &= ~KN_QUEUED; 1875 kq->kq_count--; 1876 continue; 1877 } 1878 if (kn == marker) { 1879 KQ_FLUX_WAKEUP(kq); 1880 if (count == maxevents) 1881 goto retry; 1882 goto done; 1883 } 1884 KASSERT(!kn_in_flux(kn), 1885 ("knote %p is unexpectedly in flux", kn)); 1886 1887 if ((kn->kn_flags & EV_DROP) == EV_DROP) { 1888 kn->kn_status &= ~KN_QUEUED; 1889 kn_enter_flux(kn); 1890 kq->kq_count--; 1891 KQ_UNLOCK(kq); 1892 /* 1893 * We don't need to lock the list since we've 1894 * marked it as in flux. 1895 */ 1896 knote_drop(kn, td); 1897 KQ_LOCK(kq); 1898 continue; 1899 } else if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) { 1900 kn->kn_status &= ~KN_QUEUED; 1901 kn_enter_flux(kn); 1902 kq->kq_count--; 1903 KQ_UNLOCK(kq); 1904 /* 1905 * We don't need to lock the list since we've 1906 * marked the knote as being in flux. 1907 */ 1908 *kevp = kn->kn_kevent; 1909 knote_drop(kn, td); 1910 KQ_LOCK(kq); 1911 kn = NULL; 1912 } else { 1913 kn->kn_status |= KN_SCAN; 1914 kn_enter_flux(kn); 1915 KQ_UNLOCK(kq); 1916 if ((kn->kn_status & KN_KQUEUE) == KN_KQUEUE) 1917 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1918 knl = kn_list_lock(kn); 1919 if (kn->kn_fop->f_event(kn, 0) == 0) { 1920 KQ_LOCK(kq); 1921 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1922 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE | 1923 KN_SCAN); 1924 kn_leave_flux(kn); 1925 kq->kq_count--; 1926 kn_list_unlock(knl); 1927 influx = 1; 1928 continue; 1929 } 1930 touch = (!kn->kn_fop->f_isfd && 1931 kn->kn_fop->f_touch != NULL); 1932 if (touch) 1933 kn->kn_fop->f_touch(kn, kevp, EVENT_PROCESS); 1934 else 1935 *kevp = kn->kn_kevent; 1936 KQ_LOCK(kq); 1937 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1938 if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) { 1939 /* 1940 * Manually clear knotes who weren't 1941 * 'touch'ed. 1942 */ 1943 if (touch == 0 && kn->kn_flags & EV_CLEAR) { 1944 kn->kn_data = 0; 1945 kn->kn_fflags = 0; 1946 } 1947 if (kn->kn_flags & EV_DISPATCH) 1948 kn->kn_status |= KN_DISABLED; 1949 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 1950 kq->kq_count--; 1951 } else 1952 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 1953 1954 kn->kn_status &= ~KN_SCAN; 1955 kn_leave_flux(kn); 1956 kn_list_unlock(knl); 1957 influx = 1; 1958 } 1959 1960 /* we are returning a copy to the user */ 1961 kevp++; 1962 nkev++; 1963 count--; 1964 1965 if (nkev == KQ_NEVENTS) { 1966 influx = 0; 1967 KQ_UNLOCK_FLUX(kq); 1968 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1969 nkev = 0; 1970 kevp = keva; 1971 KQ_LOCK(kq); 1972 if (error) 1973 break; 1974 } 1975 } 1976 TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); 1977 done: 1978 KQ_OWNED(kq); 1979 KQ_UNLOCK_FLUX(kq); 1980 knote_free(marker); 1981 done_nl: 1982 KQ_NOTOWNED(kq); 1983 if (nkev != 0) 1984 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1985 td->td_retval[0] = maxevents - count; 1986 return (error); 1987 } 1988 1989 /*ARGSUSED*/ 1990 static int 1991 kqueue_ioctl(struct file *fp, u_long cmd, void *data, 1992 struct ucred *active_cred, struct thread *td) 1993 { 1994 /* 1995 * Enabling sigio causes two major problems: 1996 * 1) infinite recursion: 1997 * Synopsys: kevent is being used to track signals and have FIOASYNC 1998 * set. On receipt of a signal this will cause a kqueue to recurse 1999 * into itself over and over. Sending the sigio causes the kqueue 2000 * to become ready, which in turn posts sigio again, forever. 2001 * Solution: this can be solved by setting a flag in the kqueue that 2002 * we have a SIGIO in progress. 2003 * 2) locking problems: 2004 * Synopsys: Kqueue is a leaf subsystem, but adding signalling puts 2005 * us above the proc and pgrp locks. 2006 * Solution: Post a signal using an async mechanism, being sure to 2007 * record a generation count in the delivery so that we do not deliver 2008 * a signal to the wrong process. 2009 * 2010 * Note, these two mechanisms are somewhat mutually exclusive! 2011 */ 2012 #if 0 2013 struct kqueue *kq; 2014 2015 kq = fp->f_data; 2016 switch (cmd) { 2017 case FIOASYNC: 2018 if (*(int *)data) { 2019 kq->kq_state |= KQ_ASYNC; 2020 } else { 2021 kq->kq_state &= ~KQ_ASYNC; 2022 } 2023 return (0); 2024 2025 case FIOSETOWN: 2026 return (fsetown(*(int *)data, &kq->kq_sigio)); 2027 2028 case FIOGETOWN: 2029 *(int *)data = fgetown(&kq->kq_sigio); 2030 return (0); 2031 } 2032 #endif 2033 2034 return (ENOTTY); 2035 } 2036 2037 /*ARGSUSED*/ 2038 static int 2039 kqueue_poll(struct file *fp, int events, struct ucred *active_cred, 2040 struct thread *td) 2041 { 2042 struct kqueue *kq; 2043 int revents = 0; 2044 int error; 2045 2046 if ((error = kqueue_acquire(fp, &kq))) 2047 return POLLERR; 2048 2049 KQ_LOCK(kq); 2050 if (events & (POLLIN | POLLRDNORM)) { 2051 if (kq->kq_count) { 2052 revents |= events & (POLLIN | POLLRDNORM); 2053 } else { 2054 selrecord(td, &kq->kq_sel); 2055 if (SEL_WAITING(&kq->kq_sel)) 2056 kq->kq_state |= KQ_SEL; 2057 } 2058 } 2059 kqueue_release(kq, 1); 2060 KQ_UNLOCK(kq); 2061 return (revents); 2062 } 2063 2064 /*ARGSUSED*/ 2065 static int 2066 kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred, 2067 struct thread *td) 2068 { 2069 2070 bzero((void *)st, sizeof *st); 2071 /* 2072 * We no longer return kq_count because the unlocked value is useless. 2073 * If you spent all this time getting the count, why not spend your 2074 * syscall better by calling kevent? 2075 * 2076 * XXX - This is needed for libc_r. 2077 */ 2078 st->st_mode = S_IFIFO; 2079 return (0); 2080 } 2081 2082 static void 2083 kqueue_drain(struct kqueue *kq, struct thread *td) 2084 { 2085 struct knote *kn; 2086 int i; 2087 2088 KQ_LOCK(kq); 2089 2090 KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING, 2091 ("kqueue already closing")); 2092 kq->kq_state |= KQ_CLOSING; 2093 if (kq->kq_refcnt > 1) 2094 msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0); 2095 2096 KASSERT(kq->kq_refcnt == 1, ("other refs are out there!")); 2097 2098 KASSERT(knlist_empty(&kq->kq_sel.si_note), 2099 ("kqueue's knlist not empty")); 2100 2101 for (i = 0; i < kq->kq_knlistsize; i++) { 2102 while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) { 2103 if (kn_in_flux(kn)) { 2104 kq->kq_state |= KQ_FLUXWAIT; 2105 msleep(kq, &kq->kq_lock, PSOCK, "kqclo1", 0); 2106 continue; 2107 } 2108 kn_enter_flux(kn); 2109 KQ_UNLOCK(kq); 2110 knote_drop(kn, td); 2111 KQ_LOCK(kq); 2112 } 2113 } 2114 if (kq->kq_knhashmask != 0) { 2115 for (i = 0; i <= kq->kq_knhashmask; i++) { 2116 while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) { 2117 if (kn_in_flux(kn)) { 2118 kq->kq_state |= KQ_FLUXWAIT; 2119 msleep(kq, &kq->kq_lock, PSOCK, 2120 "kqclo2", 0); 2121 continue; 2122 } 2123 kn_enter_flux(kn); 2124 KQ_UNLOCK(kq); 2125 knote_drop(kn, td); 2126 KQ_LOCK(kq); 2127 } 2128 } 2129 } 2130 2131 if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) { 2132 kq->kq_state |= KQ_TASKDRAIN; 2133 msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0); 2134 } 2135 2136 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2137 selwakeuppri(&kq->kq_sel, PSOCK); 2138 if (!SEL_WAITING(&kq->kq_sel)) 2139 kq->kq_state &= ~KQ_SEL; 2140 } 2141 2142 KQ_UNLOCK(kq); 2143 } 2144 2145 static void 2146 kqueue_destroy(struct kqueue *kq) 2147 { 2148 2149 KASSERT(kq->kq_fdp == NULL, 2150 ("kqueue still attached to a file descriptor")); 2151 seldrain(&kq->kq_sel); 2152 knlist_destroy(&kq->kq_sel.si_note); 2153 mtx_destroy(&kq->kq_lock); 2154 2155 if (kq->kq_knhash != NULL) 2156 free(kq->kq_knhash, M_KQUEUE); 2157 if (kq->kq_knlist != NULL) 2158 free(kq->kq_knlist, M_KQUEUE); 2159 2160 funsetown(&kq->kq_sigio); 2161 } 2162 2163 /*ARGSUSED*/ 2164 static int 2165 kqueue_close(struct file *fp, struct thread *td) 2166 { 2167 struct kqueue *kq = fp->f_data; 2168 struct filedesc *fdp; 2169 int error; 2170 int filedesc_unlock; 2171 2172 if ((error = kqueue_acquire(fp, &kq))) 2173 return error; 2174 kqueue_drain(kq, td); 2175 2176 /* 2177 * We could be called due to the knote_drop() doing fdrop(), 2178 * called from kqueue_register(). In this case the global 2179 * lock is owned, and filedesc sx is locked before, to not 2180 * take the sleepable lock after non-sleepable. 2181 */ 2182 fdp = kq->kq_fdp; 2183 kq->kq_fdp = NULL; 2184 if (!sx_xlocked(FILEDESC_LOCK(fdp))) { 2185 FILEDESC_XLOCK(fdp); 2186 filedesc_unlock = 1; 2187 } else 2188 filedesc_unlock = 0; 2189 TAILQ_REMOVE(&fdp->fd_kqlist, kq, kq_list); 2190 if (filedesc_unlock) 2191 FILEDESC_XUNLOCK(fdp); 2192 2193 kqueue_destroy(kq); 2194 chgkqcnt(kq->kq_cred->cr_ruidinfo, -1, 0); 2195 crfree(kq->kq_cred); 2196 free(kq, M_KQUEUE); 2197 fp->f_data = NULL; 2198 2199 return (0); 2200 } 2201 2202 static int 2203 kqueue_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 2204 { 2205 2206 kif->kf_type = KF_TYPE_KQUEUE; 2207 return (0); 2208 } 2209 2210 static void 2211 kqueue_wakeup(struct kqueue *kq) 2212 { 2213 KQ_OWNED(kq); 2214 2215 if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) { 2216 kq->kq_state &= ~KQ_SLEEP; 2217 wakeup(kq); 2218 } 2219 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2220 selwakeuppri(&kq->kq_sel, PSOCK); 2221 if (!SEL_WAITING(&kq->kq_sel)) 2222 kq->kq_state &= ~KQ_SEL; 2223 } 2224 if (!knlist_empty(&kq->kq_sel.si_note)) 2225 kqueue_schedtask(kq); 2226 if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) { 2227 pgsigio(&kq->kq_sigio, SIGIO, 0); 2228 } 2229 } 2230 2231 /* 2232 * Walk down a list of knotes, activating them if their event has triggered. 2233 * 2234 * There is a possibility to optimize in the case of one kq watching another. 2235 * Instead of scheduling a task to wake it up, you could pass enough state 2236 * down the chain to make up the parent kqueue. Make this code functional 2237 * first. 2238 */ 2239 void 2240 knote(struct knlist *list, long hint, int lockflags) 2241 { 2242 struct kqueue *kq; 2243 struct knote *kn, *tkn; 2244 int error; 2245 2246 if (list == NULL) 2247 return; 2248 2249 KNL_ASSERT_LOCK(list, lockflags & KNF_LISTLOCKED); 2250 2251 if ((lockflags & KNF_LISTLOCKED) == 0) 2252 list->kl_lock(list->kl_lockarg); 2253 2254 /* 2255 * If we unlock the list lock (and enter influx), we can 2256 * eliminate the kqueue scheduling, but this will introduce 2257 * four lock/unlock's for each knote to test. Also, marker 2258 * would be needed to keep iteration position, since filters 2259 * or other threads could remove events. 2260 */ 2261 SLIST_FOREACH_SAFE(kn, &list->kl_list, kn_selnext, tkn) { 2262 kq = kn->kn_kq; 2263 KQ_LOCK(kq); 2264 if (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0) { 2265 /* 2266 * Do not process the influx notes, except for 2267 * the influx coming from the kq unlock in the 2268 * kqueue_scan(). In the later case, we do 2269 * not interfere with the scan, since the code 2270 * fragment in kqueue_scan() locks the knlist, 2271 * and cannot proceed until we finished. 2272 */ 2273 KQ_UNLOCK(kq); 2274 } else if ((lockflags & KNF_NOKQLOCK) != 0) { 2275 kn_enter_flux(kn); 2276 KQ_UNLOCK(kq); 2277 error = kn->kn_fop->f_event(kn, hint); 2278 KQ_LOCK(kq); 2279 kn_leave_flux(kn); 2280 if (error) 2281 KNOTE_ACTIVATE(kn, 1); 2282 KQ_UNLOCK_FLUX(kq); 2283 } else { 2284 if (kn->kn_fop->f_event(kn, hint)) 2285 KNOTE_ACTIVATE(kn, 1); 2286 KQ_UNLOCK(kq); 2287 } 2288 } 2289 if ((lockflags & KNF_LISTLOCKED) == 0) 2290 list->kl_unlock(list->kl_lockarg); 2291 } 2292 2293 /* 2294 * add a knote to a knlist 2295 */ 2296 void 2297 knlist_add(struct knlist *knl, struct knote *kn, int islocked) 2298 { 2299 2300 KNL_ASSERT_LOCK(knl, islocked); 2301 KQ_NOTOWNED(kn->kn_kq); 2302 KASSERT(kn_in_flux(kn), ("knote %p not in flux", kn)); 2303 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2304 ("knote %p was not detached", kn)); 2305 if (!islocked) 2306 knl->kl_lock(knl->kl_lockarg); 2307 SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext); 2308 if (!islocked) 2309 knl->kl_unlock(knl->kl_lockarg); 2310 KQ_LOCK(kn->kn_kq); 2311 kn->kn_knlist = knl; 2312 kn->kn_status &= ~KN_DETACHED; 2313 KQ_UNLOCK(kn->kn_kq); 2314 } 2315 2316 static void 2317 knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked, 2318 int kqislocked) 2319 { 2320 2321 KASSERT(!kqislocked || knlislocked, ("kq locked w/o knl locked")); 2322 KNL_ASSERT_LOCK(knl, knlislocked); 2323 mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED); 2324 KASSERT(kqislocked || kn_in_flux(kn), ("knote %p not in flux", kn)); 2325 KASSERT((kn->kn_status & KN_DETACHED) == 0, 2326 ("knote %p was already detached", kn)); 2327 if (!knlislocked) 2328 knl->kl_lock(knl->kl_lockarg); 2329 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext); 2330 kn->kn_knlist = NULL; 2331 if (!knlislocked) 2332 kn_list_unlock(knl); 2333 if (!kqislocked) 2334 KQ_LOCK(kn->kn_kq); 2335 kn->kn_status |= KN_DETACHED; 2336 if (!kqislocked) 2337 KQ_UNLOCK(kn->kn_kq); 2338 } 2339 2340 /* 2341 * remove knote from the specified knlist 2342 */ 2343 void 2344 knlist_remove(struct knlist *knl, struct knote *kn, int islocked) 2345 { 2346 2347 knlist_remove_kq(knl, kn, islocked, 0); 2348 } 2349 2350 int 2351 knlist_empty(struct knlist *knl) 2352 { 2353 2354 KNL_ASSERT_LOCKED(knl); 2355 return (SLIST_EMPTY(&knl->kl_list)); 2356 } 2357 2358 static struct mtx knlist_lock; 2359 MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects", 2360 MTX_DEF); 2361 static void knlist_mtx_lock(void *arg); 2362 static void knlist_mtx_unlock(void *arg); 2363 2364 static void 2365 knlist_mtx_lock(void *arg) 2366 { 2367 2368 mtx_lock((struct mtx *)arg); 2369 } 2370 2371 static void 2372 knlist_mtx_unlock(void *arg) 2373 { 2374 2375 mtx_unlock((struct mtx *)arg); 2376 } 2377 2378 static void 2379 knlist_mtx_assert_locked(void *arg) 2380 { 2381 2382 mtx_assert((struct mtx *)arg, MA_OWNED); 2383 } 2384 2385 static void 2386 knlist_mtx_assert_unlocked(void *arg) 2387 { 2388 2389 mtx_assert((struct mtx *)arg, MA_NOTOWNED); 2390 } 2391 2392 static void 2393 knlist_rw_rlock(void *arg) 2394 { 2395 2396 rw_rlock((struct rwlock *)arg); 2397 } 2398 2399 static void 2400 knlist_rw_runlock(void *arg) 2401 { 2402 2403 rw_runlock((struct rwlock *)arg); 2404 } 2405 2406 static void 2407 knlist_rw_assert_locked(void *arg) 2408 { 2409 2410 rw_assert((struct rwlock *)arg, RA_LOCKED); 2411 } 2412 2413 static void 2414 knlist_rw_assert_unlocked(void *arg) 2415 { 2416 2417 rw_assert((struct rwlock *)arg, RA_UNLOCKED); 2418 } 2419 2420 void 2421 knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *), 2422 void (*kl_unlock)(void *), 2423 void (*kl_assert_locked)(void *), void (*kl_assert_unlocked)(void *)) 2424 { 2425 2426 if (lock == NULL) 2427 knl->kl_lockarg = &knlist_lock; 2428 else 2429 knl->kl_lockarg = lock; 2430 2431 if (kl_lock == NULL) 2432 knl->kl_lock = knlist_mtx_lock; 2433 else 2434 knl->kl_lock = kl_lock; 2435 if (kl_unlock == NULL) 2436 knl->kl_unlock = knlist_mtx_unlock; 2437 else 2438 knl->kl_unlock = kl_unlock; 2439 if (kl_assert_locked == NULL) 2440 knl->kl_assert_locked = knlist_mtx_assert_locked; 2441 else 2442 knl->kl_assert_locked = kl_assert_locked; 2443 if (kl_assert_unlocked == NULL) 2444 knl->kl_assert_unlocked = knlist_mtx_assert_unlocked; 2445 else 2446 knl->kl_assert_unlocked = kl_assert_unlocked; 2447 2448 knl->kl_autodestroy = 0; 2449 SLIST_INIT(&knl->kl_list); 2450 } 2451 2452 void 2453 knlist_init_mtx(struct knlist *knl, struct mtx *lock) 2454 { 2455 2456 knlist_init(knl, lock, NULL, NULL, NULL, NULL); 2457 } 2458 2459 struct knlist * 2460 knlist_alloc(struct mtx *lock) 2461 { 2462 struct knlist *knl; 2463 2464 knl = malloc(sizeof(struct knlist), M_KQUEUE, M_WAITOK); 2465 knlist_init_mtx(knl, lock); 2466 return (knl); 2467 } 2468 2469 void 2470 knlist_init_rw_reader(struct knlist *knl, struct rwlock *lock) 2471 { 2472 2473 knlist_init(knl, lock, knlist_rw_rlock, knlist_rw_runlock, 2474 knlist_rw_assert_locked, knlist_rw_assert_unlocked); 2475 } 2476 2477 void 2478 knlist_destroy(struct knlist *knl) 2479 { 2480 2481 KASSERT(KNLIST_EMPTY(knl), 2482 ("destroying knlist %p with knotes on it", knl)); 2483 } 2484 2485 void 2486 knlist_detach(struct knlist *knl) 2487 { 2488 2489 KNL_ASSERT_LOCKED(knl); 2490 knl->kl_autodestroy = 1; 2491 if (knlist_empty(knl)) { 2492 knlist_destroy(knl); 2493 free(knl, M_KQUEUE); 2494 } 2495 } 2496 2497 /* 2498 * Even if we are locked, we may need to drop the lock to allow any influx 2499 * knotes time to "settle". 2500 */ 2501 void 2502 knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn) 2503 { 2504 struct knote *kn, *kn2; 2505 struct kqueue *kq; 2506 2507 KASSERT(!knl->kl_autodestroy, ("cleardel for autodestroy %p", knl)); 2508 if (islocked) 2509 KNL_ASSERT_LOCKED(knl); 2510 else { 2511 KNL_ASSERT_UNLOCKED(knl); 2512 again: /* need to reacquire lock since we have dropped it */ 2513 knl->kl_lock(knl->kl_lockarg); 2514 } 2515 2516 SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) { 2517 kq = kn->kn_kq; 2518 KQ_LOCK(kq); 2519 if (kn_in_flux(kn)) { 2520 KQ_UNLOCK(kq); 2521 continue; 2522 } 2523 knlist_remove_kq(knl, kn, 1, 1); 2524 if (killkn) { 2525 kn_enter_flux(kn); 2526 KQ_UNLOCK(kq); 2527 knote_drop_detached(kn, td); 2528 } else { 2529 /* Make sure cleared knotes disappear soon */ 2530 kn->kn_flags |= EV_EOF | EV_ONESHOT; 2531 KQ_UNLOCK(kq); 2532 } 2533 kq = NULL; 2534 } 2535 2536 if (!SLIST_EMPTY(&knl->kl_list)) { 2537 /* there are still in flux knotes remaining */ 2538 kn = SLIST_FIRST(&knl->kl_list); 2539 kq = kn->kn_kq; 2540 KQ_LOCK(kq); 2541 KASSERT(kn_in_flux(kn), ("knote removed w/o list lock")); 2542 knl->kl_unlock(knl->kl_lockarg); 2543 kq->kq_state |= KQ_FLUXWAIT; 2544 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0); 2545 kq = NULL; 2546 goto again; 2547 } 2548 2549 if (islocked) 2550 KNL_ASSERT_LOCKED(knl); 2551 else { 2552 knl->kl_unlock(knl->kl_lockarg); 2553 KNL_ASSERT_UNLOCKED(knl); 2554 } 2555 } 2556 2557 /* 2558 * Remove all knotes referencing a specified fd must be called with FILEDESC 2559 * lock. This prevents a race where a new fd comes along and occupies the 2560 * entry and we attach a knote to the fd. 2561 */ 2562 void 2563 knote_fdclose(struct thread *td, int fd) 2564 { 2565 struct filedesc *fdp = td->td_proc->p_fd; 2566 struct kqueue *kq; 2567 struct knote *kn; 2568 int influx; 2569 2570 FILEDESC_XLOCK_ASSERT(fdp); 2571 2572 /* 2573 * We shouldn't have to worry about new kevents appearing on fd 2574 * since filedesc is locked. 2575 */ 2576 TAILQ_FOREACH(kq, &fdp->fd_kqlist, kq_list) { 2577 KQ_LOCK(kq); 2578 2579 again: 2580 influx = 0; 2581 while (kq->kq_knlistsize > fd && 2582 (kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) { 2583 if (kn_in_flux(kn)) { 2584 /* someone else might be waiting on our knote */ 2585 if (influx) 2586 wakeup(kq); 2587 kq->kq_state |= KQ_FLUXWAIT; 2588 msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0); 2589 goto again; 2590 } 2591 kn_enter_flux(kn); 2592 KQ_UNLOCK(kq); 2593 influx = 1; 2594 knote_drop(kn, td); 2595 KQ_LOCK(kq); 2596 } 2597 KQ_UNLOCK_FLUX(kq); 2598 } 2599 } 2600 2601 static int 2602 knote_attach(struct knote *kn, struct kqueue *kq) 2603 { 2604 struct klist *list; 2605 2606 KASSERT(kn_in_flux(kn), ("knote %p not marked influx", kn)); 2607 KQ_OWNED(kq); 2608 2609 if ((kq->kq_state & KQ_CLOSING) != 0) 2610 return (EBADF); 2611 if (kn->kn_fop->f_isfd) { 2612 if (kn->kn_id >= kq->kq_knlistsize) 2613 return (ENOMEM); 2614 list = &kq->kq_knlist[kn->kn_id]; 2615 } else { 2616 if (kq->kq_knhash == NULL) 2617 return (ENOMEM); 2618 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2619 } 2620 SLIST_INSERT_HEAD(list, kn, kn_link); 2621 return (0); 2622 } 2623 2624 static void 2625 knote_drop(struct knote *kn, struct thread *td) 2626 { 2627 2628 if ((kn->kn_status & KN_DETACHED) == 0) 2629 kn->kn_fop->f_detach(kn); 2630 knote_drop_detached(kn, td); 2631 } 2632 2633 static void 2634 knote_drop_detached(struct knote *kn, struct thread *td) 2635 { 2636 struct kqueue *kq; 2637 struct klist *list; 2638 2639 kq = kn->kn_kq; 2640 2641 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2642 ("knote %p still attached", kn)); 2643 KQ_NOTOWNED(kq); 2644 2645 KQ_LOCK(kq); 2646 KASSERT(kn->kn_influx == 1, 2647 ("knote_drop called on %p with influx %d", kn, kn->kn_influx)); 2648 2649 if (kn->kn_fop->f_isfd) 2650 list = &kq->kq_knlist[kn->kn_id]; 2651 else 2652 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2653 2654 if (!SLIST_EMPTY(list)) 2655 SLIST_REMOVE(list, kn, knote, kn_link); 2656 if (kn->kn_status & KN_QUEUED) 2657 knote_dequeue(kn); 2658 KQ_UNLOCK_FLUX(kq); 2659 2660 if (kn->kn_fop->f_isfd) { 2661 fdrop(kn->kn_fp, td); 2662 kn->kn_fp = NULL; 2663 } 2664 kqueue_fo_release(kn->kn_kevent.filter); 2665 kn->kn_fop = NULL; 2666 knote_free(kn); 2667 } 2668 2669 static void 2670 knote_enqueue(struct knote *kn) 2671 { 2672 struct kqueue *kq = kn->kn_kq; 2673 2674 KQ_OWNED(kn->kn_kq); 2675 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 2676 2677 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2678 kn->kn_status |= KN_QUEUED; 2679 kq->kq_count++; 2680 kqueue_wakeup(kq); 2681 } 2682 2683 static void 2684 knote_dequeue(struct knote *kn) 2685 { 2686 struct kqueue *kq = kn->kn_kq; 2687 2688 KQ_OWNED(kn->kn_kq); 2689 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 2690 2691 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 2692 kn->kn_status &= ~KN_QUEUED; 2693 kq->kq_count--; 2694 } 2695 2696 static void 2697 knote_init(void) 2698 { 2699 2700 knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL, 2701 NULL, NULL, UMA_ALIGN_PTR, 0); 2702 } 2703 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL); 2704 2705 static struct knote * 2706 knote_alloc(int waitok) 2707 { 2708 2709 return (uma_zalloc(knote_zone, (waitok ? M_WAITOK : M_NOWAIT) | 2710 M_ZERO)); 2711 } 2712 2713 static void 2714 knote_free(struct knote *kn) 2715 { 2716 2717 uma_zfree(knote_zone, kn); 2718 } 2719 2720 /* 2721 * Register the kev w/ the kq specified by fd. 2722 */ 2723 int 2724 kqfd_register(int fd, struct kevent *kev, struct thread *td, int waitok) 2725 { 2726 struct kqueue *kq; 2727 struct file *fp; 2728 cap_rights_t rights; 2729 int error; 2730 2731 error = fget(td, fd, cap_rights_init(&rights, CAP_KQUEUE_CHANGE), &fp); 2732 if (error != 0) 2733 return (error); 2734 if ((error = kqueue_acquire(fp, &kq)) != 0) 2735 goto noacquire; 2736 2737 error = kqueue_register(kq, kev, td, waitok); 2738 kqueue_release(kq, 0); 2739 2740 noacquire: 2741 fdrop(fp, td); 2742 return (error); 2743 } 2744