Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_event.c
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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: releng/12.0/sys/kern/kern_event.c 341159 2018-11-28 18:06:16Z markj $"); 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 kn->kn_status |= KN_HASKQLOCK; 554 if (kn->kn_fop->f_event(kn, NOTE_FORK)) 555 KNOTE_ACTIVATE(kn, 1); 556 kn->kn_status &= ~KN_HASKQLOCK; 557 KQ_UNLOCK(kq); 558 continue; 559 } 560 561 /* 562 * The NOTE_TRACK case. In addition to the activation 563 * of the event, we need to register new events to 564 * track the child. Drop the locks in preparation for 565 * the call to kqueue_register(). 566 */ 567 kn_enter_flux(kn); 568 KQ_UNLOCK(kq); 569 list->kl_unlock(list->kl_lockarg); 570 571 /* 572 * Activate existing knote and register tracking knotes with 573 * new process. 574 * 575 * First register a knote to get just the child notice. This 576 * must be a separate note from a potential NOTE_EXIT 577 * notification since both NOTE_CHILD and NOTE_EXIT are defined 578 * to use the data field (in conflicting ways). 579 */ 580 kev.ident = pid; 581 kev.filter = kn->kn_filter; 582 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_ONESHOT | 583 EV_FLAG2; 584 kev.fflags = kn->kn_sfflags; 585 kev.data = kn->kn_id; /* parent */ 586 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 587 error = kqueue_register(kq, &kev, NULL, 0); 588 if (error) 589 kn->kn_fflags |= NOTE_TRACKERR; 590 591 /* 592 * Then register another knote to track other potential events 593 * from the new process. 594 */ 595 kev.ident = pid; 596 kev.filter = kn->kn_filter; 597 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 598 kev.fflags = kn->kn_sfflags; 599 kev.data = kn->kn_id; /* parent */ 600 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 601 error = kqueue_register(kq, &kev, NULL, 0); 602 if (error) 603 kn->kn_fflags |= NOTE_TRACKERR; 604 if (kn->kn_fop->f_event(kn, NOTE_FORK)) 605 KNOTE_ACTIVATE(kn, 0); 606 list->kl_lock(list->kl_lockarg); 607 KQ_LOCK(kq); 608 kn_leave_flux(kn); 609 KQ_UNLOCK_FLUX(kq); 610 } 611 list->kl_unlock(list->kl_lockarg); 612 } 613 614 /* 615 * XXX: EVFILT_TIMER should perhaps live in kern_time.c beside the 616 * interval timer support code. 617 */ 618 619 #define NOTE_TIMER_PRECMASK \ 620 (NOTE_SECONDS | NOTE_MSECONDS | NOTE_USECONDS | NOTE_NSECONDS) 621 622 static sbintime_t 623 timer2sbintime(intptr_t data, int flags) 624 { 625 int64_t secs; 626 627 /* 628 * Macros for converting to the fractional second portion of an 629 * sbintime_t using 64bit multiplication to improve precision. 630 */ 631 #define NS_TO_SBT(ns) (((ns) * (((uint64_t)1 << 63) / 500000000)) >> 32) 632 #define US_TO_SBT(us) (((us) * (((uint64_t)1 << 63) / 500000)) >> 32) 633 #define MS_TO_SBT(ms) (((ms) * (((uint64_t)1 << 63) / 500)) >> 32) 634 switch (flags & NOTE_TIMER_PRECMASK) { 635 case NOTE_SECONDS: 636 #ifdef __LP64__ 637 if (data > (SBT_MAX / SBT_1S)) 638 return (SBT_MAX); 639 #endif 640 return ((sbintime_t)data << 32); 641 case NOTE_MSECONDS: /* FALLTHROUGH */ 642 case 0: 643 if (data >= 1000) { 644 secs = data / 1000; 645 #ifdef __LP64__ 646 if (secs > (SBT_MAX / SBT_1S)) 647 return (SBT_MAX); 648 #endif 649 return (secs << 32 | MS_TO_SBT(data % 1000)); 650 } 651 return (MS_TO_SBT(data)); 652 case NOTE_USECONDS: 653 if (data >= 1000000) { 654 secs = data / 1000000; 655 #ifdef __LP64__ 656 if (secs > (SBT_MAX / SBT_1S)) 657 return (SBT_MAX); 658 #endif 659 return (secs << 32 | US_TO_SBT(data % 1000000)); 660 } 661 return (US_TO_SBT(data)); 662 case NOTE_NSECONDS: 663 if (data >= 1000000000) { 664 secs = data / 1000000000; 665 #ifdef __LP64__ 666 if (secs > (SBT_MAX / SBT_1S)) 667 return (SBT_MAX); 668 #endif 669 return (secs << 32 | US_TO_SBT(data % 1000000000)); 670 } 671 return (NS_TO_SBT(data)); 672 default: 673 break; 674 } 675 return (-1); 676 } 677 678 struct kq_timer_cb_data { 679 struct callout c; 680 sbintime_t next; /* next timer event fires at */ 681 sbintime_t to; /* precalculated timer period, 0 for abs */ 682 }; 683 684 static void 685 filt_timerexpire(void *knx) 686 { 687 struct knote *kn; 688 struct kq_timer_cb_data *kc; 689 690 kn = knx; 691 kn->kn_data++; 692 KNOTE_ACTIVATE(kn, 0); /* XXX - handle locking */ 693 694 if ((kn->kn_flags & EV_ONESHOT) != 0) 695 return; 696 kc = kn->kn_ptr.p_v; 697 if (kc->to == 0) 698 return; 699 kc->next += kc->to; 700 callout_reset_sbt_on(&kc->c, kc->next, 0, filt_timerexpire, kn, 701 PCPU_GET(cpuid), C_ABSOLUTE); 702 } 703 704 /* 705 * data contains amount of time to sleep 706 */ 707 static int 708 filt_timervalidate(struct knote *kn, sbintime_t *to) 709 { 710 struct bintime bt; 711 sbintime_t sbt; 712 713 if (kn->kn_sdata < 0) 714 return (EINVAL); 715 if (kn->kn_sdata == 0 && (kn->kn_flags & EV_ONESHOT) == 0) 716 kn->kn_sdata = 1; 717 /* 718 * The only fflags values supported are the timer unit 719 * (precision) and the absolute time indicator. 720 */ 721 if ((kn->kn_sfflags & ~(NOTE_TIMER_PRECMASK | NOTE_ABSTIME)) != 0) 722 return (EINVAL); 723 724 *to = timer2sbintime(kn->kn_sdata, kn->kn_sfflags); 725 if ((kn->kn_sfflags & NOTE_ABSTIME) != 0) { 726 getboottimebin(&bt); 727 sbt = bttosbt(bt); 728 *to -= sbt; 729 } 730 if (*to < 0) 731 return (EINVAL); 732 return (0); 733 } 734 735 static int 736 filt_timerattach(struct knote *kn) 737 { 738 struct kq_timer_cb_data *kc; 739 sbintime_t to; 740 unsigned int ncallouts; 741 int error; 742 743 error = filt_timervalidate(kn, &to); 744 if (error != 0) 745 return (error); 746 747 do { 748 ncallouts = kq_ncallouts; 749 if (ncallouts >= kq_calloutmax) 750 return (ENOMEM); 751 } while (!atomic_cmpset_int(&kq_ncallouts, ncallouts, ncallouts + 1)); 752 753 if ((kn->kn_sfflags & NOTE_ABSTIME) == 0) 754 kn->kn_flags |= EV_CLEAR; /* automatically set */ 755 kn->kn_status &= ~KN_DETACHED; /* knlist_add clears it */ 756 kn->kn_ptr.p_v = kc = malloc(sizeof(*kc), M_KQUEUE, M_WAITOK); 757 callout_init(&kc->c, 1); 758 filt_timerstart(kn, to); 759 760 return (0); 761 } 762 763 static void 764 filt_timerstart(struct knote *kn, sbintime_t to) 765 { 766 struct kq_timer_cb_data *kc; 767 768 kc = kn->kn_ptr.p_v; 769 if ((kn->kn_sfflags & NOTE_ABSTIME) != 0) { 770 kc->next = to; 771 kc->to = 0; 772 } else { 773 kc->next = to + sbinuptime(); 774 kc->to = to; 775 } 776 callout_reset_sbt_on(&kc->c, kc->next, 0, filt_timerexpire, kn, 777 PCPU_GET(cpuid), C_ABSOLUTE); 778 } 779 780 static void 781 filt_timerdetach(struct knote *kn) 782 { 783 struct kq_timer_cb_data *kc; 784 unsigned int old __unused; 785 786 kc = kn->kn_ptr.p_v; 787 callout_drain(&kc->c); 788 free(kc, M_KQUEUE); 789 old = atomic_fetchadd_int(&kq_ncallouts, -1); 790 KASSERT(old > 0, ("Number of callouts cannot become negative")); 791 kn->kn_status |= KN_DETACHED; /* knlist_remove sets it */ 792 } 793 794 static void 795 filt_timertouch(struct knote *kn, struct kevent *kev, u_long type) 796 { 797 struct kq_timer_cb_data *kc; 798 struct kqueue *kq; 799 sbintime_t to; 800 int error; 801 802 switch (type) { 803 case EVENT_REGISTER: 804 /* Handle re-added timers that update data/fflags */ 805 if (kev->flags & EV_ADD) { 806 kc = kn->kn_ptr.p_v; 807 808 /* Drain any existing callout. */ 809 callout_drain(&kc->c); 810 811 /* Throw away any existing undelivered record 812 * of the timer expiration. This is done under 813 * the presumption that if a process is 814 * re-adding this timer with new parameters, 815 * it is no longer interested in what may have 816 * happened under the old parameters. If it is 817 * interested, it can wait for the expiration, 818 * delete the old timer definition, and then 819 * add the new one. 820 * 821 * This has to be done while the kq is locked: 822 * - if enqueued, dequeue 823 * - make it no longer active 824 * - clear the count of expiration events 825 */ 826 kq = kn->kn_kq; 827 KQ_LOCK(kq); 828 if (kn->kn_status & KN_QUEUED) 829 knote_dequeue(kn); 830 831 kn->kn_status &= ~KN_ACTIVE; 832 kn->kn_data = 0; 833 KQ_UNLOCK(kq); 834 835 /* Reschedule timer based on new data/fflags */ 836 kn->kn_sfflags = kev->fflags; 837 kn->kn_sdata = kev->data; 838 error = filt_timervalidate(kn, &to); 839 if (error != 0) { 840 kn->kn_flags |= EV_ERROR; 841 kn->kn_data = error; 842 } else 843 filt_timerstart(kn, to); 844 } 845 break; 846 847 case EVENT_PROCESS: 848 *kev = kn->kn_kevent; 849 if (kn->kn_flags & EV_CLEAR) { 850 kn->kn_data = 0; 851 kn->kn_fflags = 0; 852 } 853 break; 854 855 default: 856 panic("filt_timertouch() - invalid type (%ld)", type); 857 break; 858 } 859 } 860 861 static int 862 filt_timer(struct knote *kn, long hint) 863 { 864 865 return (kn->kn_data != 0); 866 } 867 868 static int 869 filt_userattach(struct knote *kn) 870 { 871 872 /* 873 * EVFILT_USER knotes are not attached to anything in the kernel. 874 */ 875 kn->kn_hook = NULL; 876 if (kn->kn_fflags & NOTE_TRIGGER) 877 kn->kn_hookid = 1; 878 else 879 kn->kn_hookid = 0; 880 return (0); 881 } 882 883 static void 884 filt_userdetach(__unused struct knote *kn) 885 { 886 887 /* 888 * EVFILT_USER knotes are not attached to anything in the kernel. 889 */ 890 } 891 892 static int 893 filt_user(struct knote *kn, __unused long hint) 894 { 895 896 return (kn->kn_hookid); 897 } 898 899 static void 900 filt_usertouch(struct knote *kn, struct kevent *kev, u_long type) 901 { 902 u_int ffctrl; 903 904 switch (type) { 905 case EVENT_REGISTER: 906 if (kev->fflags & NOTE_TRIGGER) 907 kn->kn_hookid = 1; 908 909 ffctrl = kev->fflags & NOTE_FFCTRLMASK; 910 kev->fflags &= NOTE_FFLAGSMASK; 911 switch (ffctrl) { 912 case NOTE_FFNOP: 913 break; 914 915 case NOTE_FFAND: 916 kn->kn_sfflags &= kev->fflags; 917 break; 918 919 case NOTE_FFOR: 920 kn->kn_sfflags |= kev->fflags; 921 break; 922 923 case NOTE_FFCOPY: 924 kn->kn_sfflags = kev->fflags; 925 break; 926 927 default: 928 /* XXX Return error? */ 929 break; 930 } 931 kn->kn_sdata = kev->data; 932 if (kev->flags & EV_CLEAR) { 933 kn->kn_hookid = 0; 934 kn->kn_data = 0; 935 kn->kn_fflags = 0; 936 } 937 break; 938 939 case EVENT_PROCESS: 940 *kev = kn->kn_kevent; 941 kev->fflags = kn->kn_sfflags; 942 kev->data = kn->kn_sdata; 943 if (kn->kn_flags & EV_CLEAR) { 944 kn->kn_hookid = 0; 945 kn->kn_data = 0; 946 kn->kn_fflags = 0; 947 } 948 break; 949 950 default: 951 panic("filt_usertouch() - invalid type (%ld)", type); 952 break; 953 } 954 } 955 956 int 957 sys_kqueue(struct thread *td, struct kqueue_args *uap) 958 { 959 960 return (kern_kqueue(td, 0, NULL)); 961 } 962 963 static void 964 kqueue_init(struct kqueue *kq) 965 { 966 967 mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF | MTX_DUPOK); 968 TAILQ_INIT(&kq->kq_head); 969 knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock); 970 TASK_INIT(&kq->kq_task, 0, kqueue_task, kq); 971 } 972 973 int 974 kern_kqueue(struct thread *td, int flags, struct filecaps *fcaps) 975 { 976 struct filedesc *fdp; 977 struct kqueue *kq; 978 struct file *fp; 979 struct ucred *cred; 980 int fd, error; 981 982 fdp = td->td_proc->p_fd; 983 cred = td->td_ucred; 984 if (!chgkqcnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_KQUEUES))) 985 return (ENOMEM); 986 987 error = falloc_caps(td, &fp, &fd, flags, fcaps); 988 if (error != 0) { 989 chgkqcnt(cred->cr_ruidinfo, -1, 0); 990 return (error); 991 } 992 993 /* An extra reference on `fp' has been held for us by falloc(). */ 994 kq = malloc(sizeof *kq, M_KQUEUE, M_WAITOK | M_ZERO); 995 kqueue_init(kq); 996 kq->kq_fdp = fdp; 997 kq->kq_cred = crhold(cred); 998 999 FILEDESC_XLOCK(fdp); 1000 TAILQ_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list); 1001 FILEDESC_XUNLOCK(fdp); 1002 1003 finit(fp, FREAD | FWRITE, DTYPE_KQUEUE, kq, &kqueueops); 1004 fdrop(fp, td); 1005 1006 td->td_retval[0] = fd; 1007 return (0); 1008 } 1009 1010 struct g_kevent_args { 1011 int fd; 1012 void *changelist; 1013 int nchanges; 1014 void *eventlist; 1015 int nevents; 1016 const struct timespec *timeout; 1017 }; 1018 1019 int 1020 sys_kevent(struct thread *td, struct kevent_args *uap) 1021 { 1022 struct kevent_copyops k_ops = { 1023 .arg = uap, 1024 .k_copyout = kevent_copyout, 1025 .k_copyin = kevent_copyin, 1026 .kevent_size = sizeof(struct kevent), 1027 }; 1028 struct g_kevent_args gk_args = { 1029 .fd = uap->fd, 1030 .changelist = uap->changelist, 1031 .nchanges = uap->nchanges, 1032 .eventlist = uap->eventlist, 1033 .nevents = uap->nevents, 1034 .timeout = uap->timeout, 1035 }; 1036 1037 return (kern_kevent_generic(td, &gk_args, &k_ops, "kevent")); 1038 } 1039 1040 static int 1041 kern_kevent_generic(struct thread *td, struct g_kevent_args *uap, 1042 struct kevent_copyops *k_ops, const char *struct_name) 1043 { 1044 struct timespec ts, *tsp; 1045 #ifdef KTRACE 1046 struct kevent *eventlist = uap->eventlist; 1047 #endif 1048 int error; 1049 1050 if (uap->timeout != NULL) { 1051 error = copyin(uap->timeout, &ts, sizeof(ts)); 1052 if (error) 1053 return (error); 1054 tsp = &ts; 1055 } else 1056 tsp = NULL; 1057 1058 #ifdef KTRACE 1059 if (KTRPOINT(td, KTR_STRUCT_ARRAY)) 1060 ktrstructarray(struct_name, UIO_USERSPACE, uap->changelist, 1061 uap->nchanges, k_ops->kevent_size); 1062 #endif 1063 1064 error = kern_kevent(td, uap->fd, uap->nchanges, uap->nevents, 1065 k_ops, tsp); 1066 1067 #ifdef KTRACE 1068 if (error == 0 && KTRPOINT(td, KTR_STRUCT_ARRAY)) 1069 ktrstructarray(struct_name, UIO_USERSPACE, eventlist, 1070 td->td_retval[0], k_ops->kevent_size); 1071 #endif 1072 1073 return (error); 1074 } 1075 1076 /* 1077 * Copy 'count' items into the destination list pointed to by uap->eventlist. 1078 */ 1079 static int 1080 kevent_copyout(void *arg, struct kevent *kevp, int count) 1081 { 1082 struct kevent_args *uap; 1083 int error; 1084 1085 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1086 uap = (struct kevent_args *)arg; 1087 1088 error = copyout(kevp, uap->eventlist, count * sizeof *kevp); 1089 if (error == 0) 1090 uap->eventlist += count; 1091 return (error); 1092 } 1093 1094 /* 1095 * Copy 'count' items from the list pointed to by uap->changelist. 1096 */ 1097 static int 1098 kevent_copyin(void *arg, struct kevent *kevp, int count) 1099 { 1100 struct kevent_args *uap; 1101 int error; 1102 1103 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1104 uap = (struct kevent_args *)arg; 1105 1106 error = copyin(uap->changelist, kevp, count * sizeof *kevp); 1107 if (error == 0) 1108 uap->changelist += count; 1109 return (error); 1110 } 1111 1112 #ifdef COMPAT_FREEBSD11 1113 static int 1114 kevent11_copyout(void *arg, struct kevent *kevp, int count) 1115 { 1116 struct freebsd11_kevent_args *uap; 1117 struct kevent_freebsd11 kev11; 1118 int error, i; 1119 1120 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1121 uap = (struct freebsd11_kevent_args *)arg; 1122 1123 for (i = 0; i < count; i++) { 1124 kev11.ident = kevp->ident; 1125 kev11.filter = kevp->filter; 1126 kev11.flags = kevp->flags; 1127 kev11.fflags = kevp->fflags; 1128 kev11.data = kevp->data; 1129 kev11.udata = kevp->udata; 1130 error = copyout(&kev11, uap->eventlist, sizeof(kev11)); 1131 if (error != 0) 1132 break; 1133 uap->eventlist++; 1134 kevp++; 1135 } 1136 return (error); 1137 } 1138 1139 /* 1140 * Copy 'count' items from the list pointed to by uap->changelist. 1141 */ 1142 static int 1143 kevent11_copyin(void *arg, struct kevent *kevp, int count) 1144 { 1145 struct freebsd11_kevent_args *uap; 1146 struct kevent_freebsd11 kev11; 1147 int error, i; 1148 1149 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1150 uap = (struct freebsd11_kevent_args *)arg; 1151 1152 for (i = 0; i < count; i++) { 1153 error = copyin(uap->changelist, &kev11, sizeof(kev11)); 1154 if (error != 0) 1155 break; 1156 kevp->ident = kev11.ident; 1157 kevp->filter = kev11.filter; 1158 kevp->flags = kev11.flags; 1159 kevp->fflags = kev11.fflags; 1160 kevp->data = (uintptr_t)kev11.data; 1161 kevp->udata = kev11.udata; 1162 bzero(&kevp->ext, sizeof(kevp->ext)); 1163 uap->changelist++; 1164 kevp++; 1165 } 1166 return (error); 1167 } 1168 1169 int 1170 freebsd11_kevent(struct thread *td, struct freebsd11_kevent_args *uap) 1171 { 1172 struct kevent_copyops k_ops = { 1173 .arg = uap, 1174 .k_copyout = kevent11_copyout, 1175 .k_copyin = kevent11_copyin, 1176 .kevent_size = sizeof(struct kevent_freebsd11), 1177 }; 1178 struct g_kevent_args gk_args = { 1179 .fd = uap->fd, 1180 .changelist = uap->changelist, 1181 .nchanges = uap->nchanges, 1182 .eventlist = uap->eventlist, 1183 .nevents = uap->nevents, 1184 .timeout = uap->timeout, 1185 }; 1186 1187 return (kern_kevent_generic(td, &gk_args, &k_ops, "kevent_freebsd11")); 1188 } 1189 #endif 1190 1191 int 1192 kern_kevent(struct thread *td, int fd, int nchanges, int nevents, 1193 struct kevent_copyops *k_ops, const struct timespec *timeout) 1194 { 1195 cap_rights_t rights; 1196 struct file *fp; 1197 int error; 1198 1199 cap_rights_init(&rights); 1200 if (nchanges > 0) 1201 cap_rights_set(&rights, CAP_KQUEUE_CHANGE); 1202 if (nevents > 0) 1203 cap_rights_set(&rights, CAP_KQUEUE_EVENT); 1204 error = fget(td, fd, &rights, &fp); 1205 if (error != 0) 1206 return (error); 1207 1208 error = kern_kevent_fp(td, fp, nchanges, nevents, k_ops, timeout); 1209 fdrop(fp, td); 1210 1211 return (error); 1212 } 1213 1214 static int 1215 kqueue_kevent(struct kqueue *kq, struct thread *td, int nchanges, int nevents, 1216 struct kevent_copyops *k_ops, const struct timespec *timeout) 1217 { 1218 struct kevent keva[KQ_NEVENTS]; 1219 struct kevent *kevp, *changes; 1220 int i, n, nerrors, error; 1221 1222 nerrors = 0; 1223 while (nchanges > 0) { 1224 n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges; 1225 error = k_ops->k_copyin(k_ops->arg, keva, n); 1226 if (error) 1227 return (error); 1228 changes = keva; 1229 for (i = 0; i < n; i++) { 1230 kevp = &changes[i]; 1231 if (!kevp->filter) 1232 continue; 1233 kevp->flags &= ~EV_SYSFLAGS; 1234 error = kqueue_register(kq, kevp, td, 1); 1235 if (error || (kevp->flags & EV_RECEIPT)) { 1236 if (nevents == 0) 1237 return (error); 1238 kevp->flags = EV_ERROR; 1239 kevp->data = error; 1240 (void)k_ops->k_copyout(k_ops->arg, kevp, 1); 1241 nevents--; 1242 nerrors++; 1243 } 1244 } 1245 nchanges -= n; 1246 } 1247 if (nerrors) { 1248 td->td_retval[0] = nerrors; 1249 return (0); 1250 } 1251 1252 return (kqueue_scan(kq, nevents, k_ops, timeout, keva, td)); 1253 } 1254 1255 int 1256 kern_kevent_fp(struct thread *td, struct file *fp, int nchanges, int nevents, 1257 struct kevent_copyops *k_ops, const struct timespec *timeout) 1258 { 1259 struct kqueue *kq; 1260 int error; 1261 1262 error = kqueue_acquire(fp, &kq); 1263 if (error != 0) 1264 return (error); 1265 error = kqueue_kevent(kq, td, nchanges, nevents, k_ops, timeout); 1266 kqueue_release(kq, 0); 1267 return (error); 1268 } 1269 1270 /* 1271 * Performs a kevent() call on a temporarily created kqueue. This can be 1272 * used to perform one-shot polling, similar to poll() and select(). 1273 */ 1274 int 1275 kern_kevent_anonymous(struct thread *td, int nevents, 1276 struct kevent_copyops *k_ops) 1277 { 1278 struct kqueue kq = {}; 1279 int error; 1280 1281 kqueue_init(&kq); 1282 kq.kq_refcnt = 1; 1283 error = kqueue_kevent(&kq, td, nevents, nevents, k_ops, NULL); 1284 kqueue_drain(&kq, td); 1285 kqueue_destroy(&kq); 1286 return (error); 1287 } 1288 1289 int 1290 kqueue_add_filteropts(int filt, struct filterops *filtops) 1291 { 1292 int error; 1293 1294 error = 0; 1295 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) { 1296 printf( 1297 "trying to add a filterop that is out of range: %d is beyond %d\n", 1298 ~filt, EVFILT_SYSCOUNT); 1299 return EINVAL; 1300 } 1301 mtx_lock(&filterops_lock); 1302 if (sysfilt_ops[~filt].for_fop != &null_filtops && 1303 sysfilt_ops[~filt].for_fop != NULL) 1304 error = EEXIST; 1305 else { 1306 sysfilt_ops[~filt].for_fop = filtops; 1307 sysfilt_ops[~filt].for_refcnt = 0; 1308 } 1309 mtx_unlock(&filterops_lock); 1310 1311 return (error); 1312 } 1313 1314 int 1315 kqueue_del_filteropts(int filt) 1316 { 1317 int error; 1318 1319 error = 0; 1320 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1321 return EINVAL; 1322 1323 mtx_lock(&filterops_lock); 1324 if (sysfilt_ops[~filt].for_fop == &null_filtops || 1325 sysfilt_ops[~filt].for_fop == NULL) 1326 error = EINVAL; 1327 else if (sysfilt_ops[~filt].for_refcnt != 0) 1328 error = EBUSY; 1329 else { 1330 sysfilt_ops[~filt].for_fop = &null_filtops; 1331 sysfilt_ops[~filt].for_refcnt = 0; 1332 } 1333 mtx_unlock(&filterops_lock); 1334 1335 return error; 1336 } 1337 1338 static struct filterops * 1339 kqueue_fo_find(int filt) 1340 { 1341 1342 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1343 return NULL; 1344 1345 if (sysfilt_ops[~filt].for_nolock) 1346 return sysfilt_ops[~filt].for_fop; 1347 1348 mtx_lock(&filterops_lock); 1349 sysfilt_ops[~filt].for_refcnt++; 1350 if (sysfilt_ops[~filt].for_fop == NULL) 1351 sysfilt_ops[~filt].for_fop = &null_filtops; 1352 mtx_unlock(&filterops_lock); 1353 1354 return sysfilt_ops[~filt].for_fop; 1355 } 1356 1357 static void 1358 kqueue_fo_release(int filt) 1359 { 1360 1361 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1362 return; 1363 1364 if (sysfilt_ops[~filt].for_nolock) 1365 return; 1366 1367 mtx_lock(&filterops_lock); 1368 KASSERT(sysfilt_ops[~filt].for_refcnt > 0, 1369 ("filter object refcount not valid on release")); 1370 sysfilt_ops[~filt].for_refcnt--; 1371 mtx_unlock(&filterops_lock); 1372 } 1373 1374 /* 1375 * A ref to kq (obtained via kqueue_acquire) must be held. waitok will 1376 * influence if memory allocation should wait. Make sure it is 0 if you 1377 * hold any mutexes. 1378 */ 1379 static int 1380 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, int waitok) 1381 { 1382 struct filterops *fops; 1383 struct file *fp; 1384 struct knote *kn, *tkn; 1385 struct knlist *knl; 1386 int error, filt, event; 1387 int haskqglobal, filedesc_unlock; 1388 1389 if ((kev->flags & (EV_ENABLE | EV_DISABLE)) == (EV_ENABLE | EV_DISABLE)) 1390 return (EINVAL); 1391 1392 fp = NULL; 1393 kn = NULL; 1394 knl = NULL; 1395 error = 0; 1396 haskqglobal = 0; 1397 filedesc_unlock = 0; 1398 1399 filt = kev->filter; 1400 fops = kqueue_fo_find(filt); 1401 if (fops == NULL) 1402 return EINVAL; 1403 1404 if (kev->flags & EV_ADD) { 1405 /* 1406 * Prevent waiting with locks. Non-sleepable 1407 * allocation failures are handled in the loop, only 1408 * if the spare knote appears to be actually required. 1409 */ 1410 tkn = knote_alloc(waitok); 1411 } else { 1412 tkn = NULL; 1413 } 1414 1415 findkn: 1416 if (fops->f_isfd) { 1417 KASSERT(td != NULL, ("td is NULL")); 1418 if (kev->ident > INT_MAX) 1419 error = EBADF; 1420 else 1421 error = fget(td, kev->ident, &cap_event_rights, &fp); 1422 if (error) 1423 goto done; 1424 1425 if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops, 1426 kev->ident, 0) != 0) { 1427 /* try again */ 1428 fdrop(fp, td); 1429 fp = NULL; 1430 error = kqueue_expand(kq, fops, kev->ident, waitok); 1431 if (error) 1432 goto done; 1433 goto findkn; 1434 } 1435 1436 if (fp->f_type == DTYPE_KQUEUE) { 1437 /* 1438 * If we add some intelligence about what we are doing, 1439 * we should be able to support events on ourselves. 1440 * We need to know when we are doing this to prevent 1441 * getting both the knlist lock and the kq lock since 1442 * they are the same thing. 1443 */ 1444 if (fp->f_data == kq) { 1445 error = EINVAL; 1446 goto done; 1447 } 1448 1449 /* 1450 * Pre-lock the filedesc before the global 1451 * lock mutex, see the comment in 1452 * kqueue_close(). 1453 */ 1454 FILEDESC_XLOCK(td->td_proc->p_fd); 1455 filedesc_unlock = 1; 1456 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1457 } 1458 1459 KQ_LOCK(kq); 1460 if (kev->ident < kq->kq_knlistsize) { 1461 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link) 1462 if (kev->filter == kn->kn_filter) 1463 break; 1464 } 1465 } else { 1466 if ((kev->flags & EV_ADD) == EV_ADD) { 1467 error = kqueue_expand(kq, fops, kev->ident, waitok); 1468 if (error != 0) 1469 goto done; 1470 } 1471 1472 KQ_LOCK(kq); 1473 1474 /* 1475 * If possible, find an existing knote to use for this kevent. 1476 */ 1477 if (kev->filter == EVFILT_PROC && 1478 (kev->flags & (EV_FLAG1 | EV_FLAG2)) != 0) { 1479 /* This is an internal creation of a process tracking 1480 * note. Don't attempt to coalesce this with an 1481 * existing note. 1482 */ 1483 ; 1484 } else if (kq->kq_knhashmask != 0) { 1485 struct klist *list; 1486 1487 list = &kq->kq_knhash[ 1488 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)]; 1489 SLIST_FOREACH(kn, list, kn_link) 1490 if (kev->ident == kn->kn_id && 1491 kev->filter == kn->kn_filter) 1492 break; 1493 } 1494 } 1495 1496 /* knote is in the process of changing, wait for it to stabilize. */ 1497 if (kn != NULL && kn_in_flux(kn)) { 1498 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1499 if (filedesc_unlock) { 1500 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1501 filedesc_unlock = 0; 1502 } 1503 kq->kq_state |= KQ_FLUXWAIT; 1504 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0); 1505 if (fp != NULL) { 1506 fdrop(fp, td); 1507 fp = NULL; 1508 } 1509 goto findkn; 1510 } 1511 1512 /* 1513 * kn now contains the matching knote, or NULL if no match 1514 */ 1515 if (kn == NULL) { 1516 if (kev->flags & EV_ADD) { 1517 kn = tkn; 1518 tkn = NULL; 1519 if (kn == NULL) { 1520 KQ_UNLOCK(kq); 1521 error = ENOMEM; 1522 goto done; 1523 } 1524 kn->kn_fp = fp; 1525 kn->kn_kq = kq; 1526 kn->kn_fop = fops; 1527 /* 1528 * apply reference counts to knote structure, and 1529 * do not release it at the end of this routine. 1530 */ 1531 fops = NULL; 1532 fp = NULL; 1533 1534 kn->kn_sfflags = kev->fflags; 1535 kn->kn_sdata = kev->data; 1536 kev->fflags = 0; 1537 kev->data = 0; 1538 kn->kn_kevent = *kev; 1539 kn->kn_kevent.flags &= ~(EV_ADD | EV_DELETE | 1540 EV_ENABLE | EV_DISABLE | EV_FORCEONESHOT); 1541 kn->kn_status = KN_DETACHED; 1542 if ((kev->flags & EV_DISABLE) != 0) 1543 kn->kn_status |= KN_DISABLED; 1544 kn_enter_flux(kn); 1545 1546 error = knote_attach(kn, kq); 1547 KQ_UNLOCK(kq); 1548 if (error != 0) { 1549 tkn = kn; 1550 goto done; 1551 } 1552 1553 if ((error = kn->kn_fop->f_attach(kn)) != 0) { 1554 knote_drop_detached(kn, td); 1555 goto done; 1556 } 1557 knl = kn_list_lock(kn); 1558 goto done_ev_add; 1559 } else { 1560 /* No matching knote and the EV_ADD flag is not set. */ 1561 KQ_UNLOCK(kq); 1562 error = ENOENT; 1563 goto done; 1564 } 1565 } 1566 1567 if (kev->flags & EV_DELETE) { 1568 kn_enter_flux(kn); 1569 KQ_UNLOCK(kq); 1570 knote_drop(kn, td); 1571 goto done; 1572 } 1573 1574 if (kev->flags & EV_FORCEONESHOT) { 1575 kn->kn_flags |= EV_ONESHOT; 1576 KNOTE_ACTIVATE(kn, 1); 1577 } 1578 1579 if ((kev->flags & EV_ENABLE) != 0) 1580 kn->kn_status &= ~KN_DISABLED; 1581 else if ((kev->flags & EV_DISABLE) != 0) 1582 kn->kn_status |= KN_DISABLED; 1583 1584 /* 1585 * The user may change some filter values after the initial EV_ADD, 1586 * but doing so will not reset any filter which has already been 1587 * triggered. 1588 */ 1589 kn->kn_status |= KN_SCAN; 1590 kn_enter_flux(kn); 1591 KQ_UNLOCK(kq); 1592 knl = kn_list_lock(kn); 1593 kn->kn_kevent.udata = kev->udata; 1594 if (!fops->f_isfd && fops->f_touch != NULL) { 1595 fops->f_touch(kn, kev, EVENT_REGISTER); 1596 } else { 1597 kn->kn_sfflags = kev->fflags; 1598 kn->kn_sdata = kev->data; 1599 } 1600 1601 done_ev_add: 1602 /* 1603 * We can get here with kn->kn_knlist == NULL. This can happen when 1604 * the initial attach event decides that the event is "completed" 1605 * already, e.g., filt_procattach() is called on a zombie process. It 1606 * will call filt_proc() which will remove it from the list, and NULL 1607 * kn_knlist. 1608 * 1609 * KN_DISABLED will be stable while the knote is in flux, so the 1610 * unlocked read will not race with an update. 1611 */ 1612 if ((kn->kn_status & KN_DISABLED) == 0) 1613 event = kn->kn_fop->f_event(kn, 0); 1614 else 1615 event = 0; 1616 1617 KQ_LOCK(kq); 1618 if (event) 1619 kn->kn_status |= KN_ACTIVE; 1620 if ((kn->kn_status & (KN_ACTIVE | KN_DISABLED | KN_QUEUED)) == 1621 KN_ACTIVE) 1622 knote_enqueue(kn); 1623 kn->kn_status &= ~KN_SCAN; 1624 kn_leave_flux(kn); 1625 kn_list_unlock(knl); 1626 KQ_UNLOCK_FLUX(kq); 1627 1628 done: 1629 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1630 if (filedesc_unlock) 1631 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1632 if (fp != NULL) 1633 fdrop(fp, td); 1634 knote_free(tkn); 1635 if (fops != NULL) 1636 kqueue_fo_release(filt); 1637 return (error); 1638 } 1639 1640 static int 1641 kqueue_acquire(struct file *fp, struct kqueue **kqp) 1642 { 1643 int error; 1644 struct kqueue *kq; 1645 1646 error = 0; 1647 1648 kq = fp->f_data; 1649 if (fp->f_type != DTYPE_KQUEUE || kq == NULL) 1650 return (EBADF); 1651 *kqp = kq; 1652 KQ_LOCK(kq); 1653 if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) { 1654 KQ_UNLOCK(kq); 1655 return (EBADF); 1656 } 1657 kq->kq_refcnt++; 1658 KQ_UNLOCK(kq); 1659 1660 return error; 1661 } 1662 1663 static void 1664 kqueue_release(struct kqueue *kq, int locked) 1665 { 1666 if (locked) 1667 KQ_OWNED(kq); 1668 else 1669 KQ_LOCK(kq); 1670 kq->kq_refcnt--; 1671 if (kq->kq_refcnt == 1) 1672 wakeup(&kq->kq_refcnt); 1673 if (!locked) 1674 KQ_UNLOCK(kq); 1675 } 1676 1677 static void 1678 kqueue_schedtask(struct kqueue *kq) 1679 { 1680 1681 KQ_OWNED(kq); 1682 KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN), 1683 ("scheduling kqueue task while draining")); 1684 1685 if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) { 1686 taskqueue_enqueue(taskqueue_kqueue_ctx, &kq->kq_task); 1687 kq->kq_state |= KQ_TASKSCHED; 1688 } 1689 } 1690 1691 /* 1692 * Expand the kq to make sure we have storage for fops/ident pair. 1693 * 1694 * Return 0 on success (or no work necessary), return errno on failure. 1695 * 1696 * Not calling hashinit w/ waitok (proper malloc flag) should be safe. 1697 * If kqueue_register is called from a non-fd context, there usually/should 1698 * be no locks held. 1699 */ 1700 static int 1701 kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident, 1702 int waitok) 1703 { 1704 struct klist *list, *tmp_knhash, *to_free; 1705 u_long tmp_knhashmask; 1706 int error, fd, size; 1707 int mflag = waitok ? M_WAITOK : M_NOWAIT; 1708 1709 KQ_NOTOWNED(kq); 1710 1711 error = 0; 1712 to_free = NULL; 1713 if (fops->f_isfd) { 1714 fd = ident; 1715 if (kq->kq_knlistsize <= fd) { 1716 size = kq->kq_knlistsize; 1717 while (size <= fd) 1718 size += KQEXTENT; 1719 list = malloc(size * sizeof(*list), M_KQUEUE, mflag); 1720 if (list == NULL) 1721 return ENOMEM; 1722 KQ_LOCK(kq); 1723 if ((kq->kq_state & KQ_CLOSING) != 0) { 1724 to_free = list; 1725 error = EBADF; 1726 } else if (kq->kq_knlistsize > fd) { 1727 to_free = list; 1728 } else { 1729 if (kq->kq_knlist != NULL) { 1730 bcopy(kq->kq_knlist, list, 1731 kq->kq_knlistsize * sizeof(*list)); 1732 to_free = kq->kq_knlist; 1733 kq->kq_knlist = NULL; 1734 } 1735 bzero((caddr_t)list + 1736 kq->kq_knlistsize * sizeof(*list), 1737 (size - kq->kq_knlistsize) * sizeof(*list)); 1738 kq->kq_knlistsize = size; 1739 kq->kq_knlist = list; 1740 } 1741 KQ_UNLOCK(kq); 1742 } 1743 } else { 1744 if (kq->kq_knhashmask == 0) { 1745 tmp_knhash = hashinit(KN_HASHSIZE, M_KQUEUE, 1746 &tmp_knhashmask); 1747 if (tmp_knhash == NULL) 1748 return (ENOMEM); 1749 KQ_LOCK(kq); 1750 if ((kq->kq_state & KQ_CLOSING) != 0) { 1751 to_free = tmp_knhash; 1752 error = EBADF; 1753 } else if (kq->kq_knhashmask == 0) { 1754 kq->kq_knhash = tmp_knhash; 1755 kq->kq_knhashmask = tmp_knhashmask; 1756 } else { 1757 to_free = tmp_knhash; 1758 } 1759 KQ_UNLOCK(kq); 1760 } 1761 } 1762 free(to_free, M_KQUEUE); 1763 1764 KQ_NOTOWNED(kq); 1765 return (error); 1766 } 1767 1768 static void 1769 kqueue_task(void *arg, int pending) 1770 { 1771 struct kqueue *kq; 1772 int haskqglobal; 1773 1774 haskqglobal = 0; 1775 kq = arg; 1776 1777 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1778 KQ_LOCK(kq); 1779 1780 KNOTE_LOCKED(&kq->kq_sel.si_note, 0); 1781 1782 kq->kq_state &= ~KQ_TASKSCHED; 1783 if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) { 1784 wakeup(&kq->kq_state); 1785 } 1786 KQ_UNLOCK(kq); 1787 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1788 } 1789 1790 /* 1791 * Scan, update kn_data (if not ONESHOT), and copyout triggered events. 1792 * We treat KN_MARKER knotes as if they are in flux. 1793 */ 1794 static int 1795 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops, 1796 const struct timespec *tsp, struct kevent *keva, struct thread *td) 1797 { 1798 struct kevent *kevp; 1799 struct knote *kn, *marker; 1800 struct knlist *knl; 1801 sbintime_t asbt, rsbt; 1802 int count, error, haskqglobal, influx, nkev, touch; 1803 1804 count = maxevents; 1805 nkev = 0; 1806 error = 0; 1807 haskqglobal = 0; 1808 1809 if (maxevents == 0) 1810 goto done_nl; 1811 1812 rsbt = 0; 1813 if (tsp != NULL) { 1814 if (tsp->tv_sec < 0 || tsp->tv_nsec < 0 || 1815 tsp->tv_nsec >= 1000000000) { 1816 error = EINVAL; 1817 goto done_nl; 1818 } 1819 if (timespecisset(tsp)) { 1820 if (tsp->tv_sec <= INT32_MAX) { 1821 rsbt = tstosbt(*tsp); 1822 if (TIMESEL(&asbt, rsbt)) 1823 asbt += tc_tick_sbt; 1824 if (asbt <= SBT_MAX - rsbt) 1825 asbt += rsbt; 1826 else 1827 asbt = 0; 1828 rsbt >>= tc_precexp; 1829 } else 1830 asbt = 0; 1831 } else 1832 asbt = -1; 1833 } else 1834 asbt = 0; 1835 marker = knote_alloc(1); 1836 marker->kn_status = KN_MARKER; 1837 KQ_LOCK(kq); 1838 1839 retry: 1840 kevp = keva; 1841 if (kq->kq_count == 0) { 1842 if (asbt == -1) { 1843 error = EWOULDBLOCK; 1844 } else { 1845 kq->kq_state |= KQ_SLEEP; 1846 error = msleep_sbt(kq, &kq->kq_lock, PSOCK | PCATCH, 1847 "kqread", asbt, rsbt, C_ABSOLUTE); 1848 } 1849 if (error == 0) 1850 goto retry; 1851 /* don't restart after signals... */ 1852 if (error == ERESTART) 1853 error = EINTR; 1854 else if (error == EWOULDBLOCK) 1855 error = 0; 1856 goto done; 1857 } 1858 1859 TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); 1860 influx = 0; 1861 while (count) { 1862 KQ_OWNED(kq); 1863 kn = TAILQ_FIRST(&kq->kq_head); 1864 1865 if ((kn->kn_status == KN_MARKER && kn != marker) || 1866 kn_in_flux(kn)) { 1867 if (influx) { 1868 influx = 0; 1869 KQ_FLUX_WAKEUP(kq); 1870 } 1871 kq->kq_state |= KQ_FLUXWAIT; 1872 error = msleep(kq, &kq->kq_lock, PSOCK, 1873 "kqflxwt", 0); 1874 continue; 1875 } 1876 1877 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1878 if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) { 1879 kn->kn_status &= ~KN_QUEUED; 1880 kq->kq_count--; 1881 continue; 1882 } 1883 if (kn == marker) { 1884 KQ_FLUX_WAKEUP(kq); 1885 if (count == maxevents) 1886 goto retry; 1887 goto done; 1888 } 1889 KASSERT(!kn_in_flux(kn), 1890 ("knote %p is unexpectedly in flux", kn)); 1891 1892 if ((kn->kn_flags & EV_DROP) == EV_DROP) { 1893 kn->kn_status &= ~KN_QUEUED; 1894 kn_enter_flux(kn); 1895 kq->kq_count--; 1896 KQ_UNLOCK(kq); 1897 /* 1898 * We don't need to lock the list since we've 1899 * marked it as in flux. 1900 */ 1901 knote_drop(kn, td); 1902 KQ_LOCK(kq); 1903 continue; 1904 } else if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) { 1905 kn->kn_status &= ~KN_QUEUED; 1906 kn_enter_flux(kn); 1907 kq->kq_count--; 1908 KQ_UNLOCK(kq); 1909 /* 1910 * We don't need to lock the list since we've 1911 * marked the knote as being in flux. 1912 */ 1913 *kevp = kn->kn_kevent; 1914 knote_drop(kn, td); 1915 KQ_LOCK(kq); 1916 kn = NULL; 1917 } else { 1918 kn->kn_status |= KN_SCAN; 1919 kn_enter_flux(kn); 1920 KQ_UNLOCK(kq); 1921 if ((kn->kn_status & KN_KQUEUE) == KN_KQUEUE) 1922 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1923 knl = kn_list_lock(kn); 1924 if (kn->kn_fop->f_event(kn, 0) == 0) { 1925 KQ_LOCK(kq); 1926 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1927 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE | 1928 KN_SCAN); 1929 kn_leave_flux(kn); 1930 kq->kq_count--; 1931 kn_list_unlock(knl); 1932 influx = 1; 1933 continue; 1934 } 1935 touch = (!kn->kn_fop->f_isfd && 1936 kn->kn_fop->f_touch != NULL); 1937 if (touch) 1938 kn->kn_fop->f_touch(kn, kevp, EVENT_PROCESS); 1939 else 1940 *kevp = kn->kn_kevent; 1941 KQ_LOCK(kq); 1942 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1943 if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) { 1944 /* 1945 * Manually clear knotes who weren't 1946 * 'touch'ed. 1947 */ 1948 if (touch == 0 && kn->kn_flags & EV_CLEAR) { 1949 kn->kn_data = 0; 1950 kn->kn_fflags = 0; 1951 } 1952 if (kn->kn_flags & EV_DISPATCH) 1953 kn->kn_status |= KN_DISABLED; 1954 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 1955 kq->kq_count--; 1956 } else 1957 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 1958 1959 kn->kn_status &= ~KN_SCAN; 1960 kn_leave_flux(kn); 1961 kn_list_unlock(knl); 1962 influx = 1; 1963 } 1964 1965 /* we are returning a copy to the user */ 1966 kevp++; 1967 nkev++; 1968 count--; 1969 1970 if (nkev == KQ_NEVENTS) { 1971 influx = 0; 1972 KQ_UNLOCK_FLUX(kq); 1973 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1974 nkev = 0; 1975 kevp = keva; 1976 KQ_LOCK(kq); 1977 if (error) 1978 break; 1979 } 1980 } 1981 TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); 1982 done: 1983 KQ_OWNED(kq); 1984 KQ_UNLOCK_FLUX(kq); 1985 knote_free(marker); 1986 done_nl: 1987 KQ_NOTOWNED(kq); 1988 if (nkev != 0) 1989 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1990 td->td_retval[0] = maxevents - count; 1991 return (error); 1992 } 1993 1994 /*ARGSUSED*/ 1995 static int 1996 kqueue_ioctl(struct file *fp, u_long cmd, void *data, 1997 struct ucred *active_cred, struct thread *td) 1998 { 1999 /* 2000 * Enabling sigio causes two major problems: 2001 * 1) infinite recursion: 2002 * Synopsys: kevent is being used to track signals and have FIOASYNC 2003 * set. On receipt of a signal this will cause a kqueue to recurse 2004 * into itself over and over. Sending the sigio causes the kqueue 2005 * to become ready, which in turn posts sigio again, forever. 2006 * Solution: this can be solved by setting a flag in the kqueue that 2007 * we have a SIGIO in progress. 2008 * 2) locking problems: 2009 * Synopsys: Kqueue is a leaf subsystem, but adding signalling puts 2010 * us above the proc and pgrp locks. 2011 * Solution: Post a signal using an async mechanism, being sure to 2012 * record a generation count in the delivery so that we do not deliver 2013 * a signal to the wrong process. 2014 * 2015 * Note, these two mechanisms are somewhat mutually exclusive! 2016 */ 2017 #if 0 2018 struct kqueue *kq; 2019 2020 kq = fp->f_data; 2021 switch (cmd) { 2022 case FIOASYNC: 2023 if (*(int *)data) { 2024 kq->kq_state |= KQ_ASYNC; 2025 } else { 2026 kq->kq_state &= ~KQ_ASYNC; 2027 } 2028 return (0); 2029 2030 case FIOSETOWN: 2031 return (fsetown(*(int *)data, &kq->kq_sigio)); 2032 2033 case FIOGETOWN: 2034 *(int *)data = fgetown(&kq->kq_sigio); 2035 return (0); 2036 } 2037 #endif 2038 2039 return (ENOTTY); 2040 } 2041 2042 /*ARGSUSED*/ 2043 static int 2044 kqueue_poll(struct file *fp, int events, struct ucred *active_cred, 2045 struct thread *td) 2046 { 2047 struct kqueue *kq; 2048 int revents = 0; 2049 int error; 2050 2051 if ((error = kqueue_acquire(fp, &kq))) 2052 return POLLERR; 2053 2054 KQ_LOCK(kq); 2055 if (events & (POLLIN | POLLRDNORM)) { 2056 if (kq->kq_count) { 2057 revents |= events & (POLLIN | POLLRDNORM); 2058 } else { 2059 selrecord(td, &kq->kq_sel); 2060 if (SEL_WAITING(&kq->kq_sel)) 2061 kq->kq_state |= KQ_SEL; 2062 } 2063 } 2064 kqueue_release(kq, 1); 2065 KQ_UNLOCK(kq); 2066 return (revents); 2067 } 2068 2069 /*ARGSUSED*/ 2070 static int 2071 kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred, 2072 struct thread *td) 2073 { 2074 2075 bzero((void *)st, sizeof *st); 2076 /* 2077 * We no longer return kq_count because the unlocked value is useless. 2078 * If you spent all this time getting the count, why not spend your 2079 * syscall better by calling kevent? 2080 * 2081 * XXX - This is needed for libc_r. 2082 */ 2083 st->st_mode = S_IFIFO; 2084 return (0); 2085 } 2086 2087 static void 2088 kqueue_drain(struct kqueue *kq, struct thread *td) 2089 { 2090 struct knote *kn; 2091 int i; 2092 2093 KQ_LOCK(kq); 2094 2095 KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING, 2096 ("kqueue already closing")); 2097 kq->kq_state |= KQ_CLOSING; 2098 if (kq->kq_refcnt > 1) 2099 msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0); 2100 2101 KASSERT(kq->kq_refcnt == 1, ("other refs are out there!")); 2102 2103 KASSERT(knlist_empty(&kq->kq_sel.si_note), 2104 ("kqueue's knlist not empty")); 2105 2106 for (i = 0; i < kq->kq_knlistsize; i++) { 2107 while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) { 2108 if (kn_in_flux(kn)) { 2109 kq->kq_state |= KQ_FLUXWAIT; 2110 msleep(kq, &kq->kq_lock, PSOCK, "kqclo1", 0); 2111 continue; 2112 } 2113 kn_enter_flux(kn); 2114 KQ_UNLOCK(kq); 2115 knote_drop(kn, td); 2116 KQ_LOCK(kq); 2117 } 2118 } 2119 if (kq->kq_knhashmask != 0) { 2120 for (i = 0; i <= kq->kq_knhashmask; i++) { 2121 while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) { 2122 if (kn_in_flux(kn)) { 2123 kq->kq_state |= KQ_FLUXWAIT; 2124 msleep(kq, &kq->kq_lock, PSOCK, 2125 "kqclo2", 0); 2126 continue; 2127 } 2128 kn_enter_flux(kn); 2129 KQ_UNLOCK(kq); 2130 knote_drop(kn, td); 2131 KQ_LOCK(kq); 2132 } 2133 } 2134 } 2135 2136 if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) { 2137 kq->kq_state |= KQ_TASKDRAIN; 2138 msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0); 2139 } 2140 2141 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2142 selwakeuppri(&kq->kq_sel, PSOCK); 2143 if (!SEL_WAITING(&kq->kq_sel)) 2144 kq->kq_state &= ~KQ_SEL; 2145 } 2146 2147 KQ_UNLOCK(kq); 2148 } 2149 2150 static void 2151 kqueue_destroy(struct kqueue *kq) 2152 { 2153 2154 KASSERT(kq->kq_fdp == NULL, 2155 ("kqueue still attached to a file descriptor")); 2156 seldrain(&kq->kq_sel); 2157 knlist_destroy(&kq->kq_sel.si_note); 2158 mtx_destroy(&kq->kq_lock); 2159 2160 if (kq->kq_knhash != NULL) 2161 free(kq->kq_knhash, M_KQUEUE); 2162 if (kq->kq_knlist != NULL) 2163 free(kq->kq_knlist, M_KQUEUE); 2164 2165 funsetown(&kq->kq_sigio); 2166 } 2167 2168 /*ARGSUSED*/ 2169 static int 2170 kqueue_close(struct file *fp, struct thread *td) 2171 { 2172 struct kqueue *kq = fp->f_data; 2173 struct filedesc *fdp; 2174 int error; 2175 int filedesc_unlock; 2176 2177 if ((error = kqueue_acquire(fp, &kq))) 2178 return error; 2179 kqueue_drain(kq, td); 2180 2181 /* 2182 * We could be called due to the knote_drop() doing fdrop(), 2183 * called from kqueue_register(). In this case the global 2184 * lock is owned, and filedesc sx is locked before, to not 2185 * take the sleepable lock after non-sleepable. 2186 */ 2187 fdp = kq->kq_fdp; 2188 kq->kq_fdp = NULL; 2189 if (!sx_xlocked(FILEDESC_LOCK(fdp))) { 2190 FILEDESC_XLOCK(fdp); 2191 filedesc_unlock = 1; 2192 } else 2193 filedesc_unlock = 0; 2194 TAILQ_REMOVE(&fdp->fd_kqlist, kq, kq_list); 2195 if (filedesc_unlock) 2196 FILEDESC_XUNLOCK(fdp); 2197 2198 kqueue_destroy(kq); 2199 chgkqcnt(kq->kq_cred->cr_ruidinfo, -1, 0); 2200 crfree(kq->kq_cred); 2201 free(kq, M_KQUEUE); 2202 fp->f_data = NULL; 2203 2204 return (0); 2205 } 2206 2207 static int 2208 kqueue_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 2209 { 2210 2211 kif->kf_type = KF_TYPE_KQUEUE; 2212 return (0); 2213 } 2214 2215 static void 2216 kqueue_wakeup(struct kqueue *kq) 2217 { 2218 KQ_OWNED(kq); 2219 2220 if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) { 2221 kq->kq_state &= ~KQ_SLEEP; 2222 wakeup(kq); 2223 } 2224 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2225 selwakeuppri(&kq->kq_sel, PSOCK); 2226 if (!SEL_WAITING(&kq->kq_sel)) 2227 kq->kq_state &= ~KQ_SEL; 2228 } 2229 if (!knlist_empty(&kq->kq_sel.si_note)) 2230 kqueue_schedtask(kq); 2231 if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) { 2232 pgsigio(&kq->kq_sigio, SIGIO, 0); 2233 } 2234 } 2235 2236 /* 2237 * Walk down a list of knotes, activating them if their event has triggered. 2238 * 2239 * There is a possibility to optimize in the case of one kq watching another. 2240 * Instead of scheduling a task to wake it up, you could pass enough state 2241 * down the chain to make up the parent kqueue. Make this code functional 2242 * first. 2243 */ 2244 void 2245 knote(struct knlist *list, long hint, int lockflags) 2246 { 2247 struct kqueue *kq; 2248 struct knote *kn, *tkn; 2249 int error; 2250 2251 if (list == NULL) 2252 return; 2253 2254 KNL_ASSERT_LOCK(list, lockflags & KNF_LISTLOCKED); 2255 2256 if ((lockflags & KNF_LISTLOCKED) == 0) 2257 list->kl_lock(list->kl_lockarg); 2258 2259 /* 2260 * If we unlock the list lock (and enter influx), we can 2261 * eliminate the kqueue scheduling, but this will introduce 2262 * four lock/unlock's for each knote to test. Also, marker 2263 * would be needed to keep iteration position, since filters 2264 * or other threads could remove events. 2265 */ 2266 SLIST_FOREACH_SAFE(kn, &list->kl_list, kn_selnext, tkn) { 2267 kq = kn->kn_kq; 2268 KQ_LOCK(kq); 2269 if (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0) { 2270 /* 2271 * Do not process the influx notes, except for 2272 * the influx coming from the kq unlock in the 2273 * kqueue_scan(). In the later case, we do 2274 * not interfere with the scan, since the code 2275 * fragment in kqueue_scan() locks the knlist, 2276 * and cannot proceed until we finished. 2277 */ 2278 KQ_UNLOCK(kq); 2279 } else if ((lockflags & KNF_NOKQLOCK) != 0) { 2280 kn_enter_flux(kn); 2281 KQ_UNLOCK(kq); 2282 error = kn->kn_fop->f_event(kn, hint); 2283 KQ_LOCK(kq); 2284 kn_leave_flux(kn); 2285 if (error) 2286 KNOTE_ACTIVATE(kn, 1); 2287 KQ_UNLOCK_FLUX(kq); 2288 } else { 2289 kn->kn_status |= KN_HASKQLOCK; 2290 if (kn->kn_fop->f_event(kn, hint)) 2291 KNOTE_ACTIVATE(kn, 1); 2292 kn->kn_status &= ~KN_HASKQLOCK; 2293 KQ_UNLOCK(kq); 2294 } 2295 } 2296 if ((lockflags & KNF_LISTLOCKED) == 0) 2297 list->kl_unlock(list->kl_lockarg); 2298 } 2299 2300 /* 2301 * add a knote to a knlist 2302 */ 2303 void 2304 knlist_add(struct knlist *knl, struct knote *kn, int islocked) 2305 { 2306 2307 KNL_ASSERT_LOCK(knl, islocked); 2308 KQ_NOTOWNED(kn->kn_kq); 2309 KASSERT(kn_in_flux(kn), ("knote %p not in flux", kn)); 2310 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2311 ("knote %p was not detached", kn)); 2312 if (!islocked) 2313 knl->kl_lock(knl->kl_lockarg); 2314 SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext); 2315 if (!islocked) 2316 knl->kl_unlock(knl->kl_lockarg); 2317 KQ_LOCK(kn->kn_kq); 2318 kn->kn_knlist = knl; 2319 kn->kn_status &= ~KN_DETACHED; 2320 KQ_UNLOCK(kn->kn_kq); 2321 } 2322 2323 static void 2324 knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked, 2325 int kqislocked) 2326 { 2327 2328 KASSERT(!kqislocked || knlislocked, ("kq locked w/o knl locked")); 2329 KNL_ASSERT_LOCK(knl, knlislocked); 2330 mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED); 2331 KASSERT(kqislocked || kn_in_flux(kn), ("knote %p not in flux", kn)); 2332 KASSERT((kn->kn_status & KN_DETACHED) == 0, 2333 ("knote %p was already detached", kn)); 2334 if (!knlislocked) 2335 knl->kl_lock(knl->kl_lockarg); 2336 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext); 2337 kn->kn_knlist = NULL; 2338 if (!knlislocked) 2339 kn_list_unlock(knl); 2340 if (!kqislocked) 2341 KQ_LOCK(kn->kn_kq); 2342 kn->kn_status |= KN_DETACHED; 2343 if (!kqislocked) 2344 KQ_UNLOCK(kn->kn_kq); 2345 } 2346 2347 /* 2348 * remove knote from the specified knlist 2349 */ 2350 void 2351 knlist_remove(struct knlist *knl, struct knote *kn, int islocked) 2352 { 2353 2354 knlist_remove_kq(knl, kn, islocked, 0); 2355 } 2356 2357 int 2358 knlist_empty(struct knlist *knl) 2359 { 2360 2361 KNL_ASSERT_LOCKED(knl); 2362 return (SLIST_EMPTY(&knl->kl_list)); 2363 } 2364 2365 static struct mtx knlist_lock; 2366 MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects", 2367 MTX_DEF); 2368 static void knlist_mtx_lock(void *arg); 2369 static void knlist_mtx_unlock(void *arg); 2370 2371 static void 2372 knlist_mtx_lock(void *arg) 2373 { 2374 2375 mtx_lock((struct mtx *)arg); 2376 } 2377 2378 static void 2379 knlist_mtx_unlock(void *arg) 2380 { 2381 2382 mtx_unlock((struct mtx *)arg); 2383 } 2384 2385 static void 2386 knlist_mtx_assert_locked(void *arg) 2387 { 2388 2389 mtx_assert((struct mtx *)arg, MA_OWNED); 2390 } 2391 2392 static void 2393 knlist_mtx_assert_unlocked(void *arg) 2394 { 2395 2396 mtx_assert((struct mtx *)arg, MA_NOTOWNED); 2397 } 2398 2399 static void 2400 knlist_rw_rlock(void *arg) 2401 { 2402 2403 rw_rlock((struct rwlock *)arg); 2404 } 2405 2406 static void 2407 knlist_rw_runlock(void *arg) 2408 { 2409 2410 rw_runlock((struct rwlock *)arg); 2411 } 2412 2413 static void 2414 knlist_rw_assert_locked(void *arg) 2415 { 2416 2417 rw_assert((struct rwlock *)arg, RA_LOCKED); 2418 } 2419 2420 static void 2421 knlist_rw_assert_unlocked(void *arg) 2422 { 2423 2424 rw_assert((struct rwlock *)arg, RA_UNLOCKED); 2425 } 2426 2427 void 2428 knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *), 2429 void (*kl_unlock)(void *), 2430 void (*kl_assert_locked)(void *), void (*kl_assert_unlocked)(void *)) 2431 { 2432 2433 if (lock == NULL) 2434 knl->kl_lockarg = &knlist_lock; 2435 else 2436 knl->kl_lockarg = lock; 2437 2438 if (kl_lock == NULL) 2439 knl->kl_lock = knlist_mtx_lock; 2440 else 2441 knl->kl_lock = kl_lock; 2442 if (kl_unlock == NULL) 2443 knl->kl_unlock = knlist_mtx_unlock; 2444 else 2445 knl->kl_unlock = kl_unlock; 2446 if (kl_assert_locked == NULL) 2447 knl->kl_assert_locked = knlist_mtx_assert_locked; 2448 else 2449 knl->kl_assert_locked = kl_assert_locked; 2450 if (kl_assert_unlocked == NULL) 2451 knl->kl_assert_unlocked = knlist_mtx_assert_unlocked; 2452 else 2453 knl->kl_assert_unlocked = kl_assert_unlocked; 2454 2455 knl->kl_autodestroy = 0; 2456 SLIST_INIT(&knl->kl_list); 2457 } 2458 2459 void 2460 knlist_init_mtx(struct knlist *knl, struct mtx *lock) 2461 { 2462 2463 knlist_init(knl, lock, NULL, NULL, NULL, NULL); 2464 } 2465 2466 struct knlist * 2467 knlist_alloc(struct mtx *lock) 2468 { 2469 struct knlist *knl; 2470 2471 knl = malloc(sizeof(struct knlist), M_KQUEUE, M_WAITOK); 2472 knlist_init_mtx(knl, lock); 2473 return (knl); 2474 } 2475 2476 void 2477 knlist_init_rw_reader(struct knlist *knl, struct rwlock *lock) 2478 { 2479 2480 knlist_init(knl, lock, knlist_rw_rlock, knlist_rw_runlock, 2481 knlist_rw_assert_locked, knlist_rw_assert_unlocked); 2482 } 2483 2484 void 2485 knlist_destroy(struct knlist *knl) 2486 { 2487 2488 KASSERT(KNLIST_EMPTY(knl), 2489 ("destroying knlist %p with knotes on it", knl)); 2490 } 2491 2492 void 2493 knlist_detach(struct knlist *knl) 2494 { 2495 2496 KNL_ASSERT_LOCKED(knl); 2497 knl->kl_autodestroy = 1; 2498 if (knlist_empty(knl)) { 2499 knlist_destroy(knl); 2500 free(knl, M_KQUEUE); 2501 } 2502 } 2503 2504 /* 2505 * Even if we are locked, we may need to drop the lock to allow any influx 2506 * knotes time to "settle". 2507 */ 2508 void 2509 knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn) 2510 { 2511 struct knote *kn, *kn2; 2512 struct kqueue *kq; 2513 2514 KASSERT(!knl->kl_autodestroy, ("cleardel for autodestroy %p", knl)); 2515 if (islocked) 2516 KNL_ASSERT_LOCKED(knl); 2517 else { 2518 KNL_ASSERT_UNLOCKED(knl); 2519 again: /* need to reacquire lock since we have dropped it */ 2520 knl->kl_lock(knl->kl_lockarg); 2521 } 2522 2523 SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) { 2524 kq = kn->kn_kq; 2525 KQ_LOCK(kq); 2526 if (kn_in_flux(kn)) { 2527 KQ_UNLOCK(kq); 2528 continue; 2529 } 2530 knlist_remove_kq(knl, kn, 1, 1); 2531 if (killkn) { 2532 kn_enter_flux(kn); 2533 KQ_UNLOCK(kq); 2534 knote_drop_detached(kn, td); 2535 } else { 2536 /* Make sure cleared knotes disappear soon */ 2537 kn->kn_flags |= EV_EOF | EV_ONESHOT; 2538 KQ_UNLOCK(kq); 2539 } 2540 kq = NULL; 2541 } 2542 2543 if (!SLIST_EMPTY(&knl->kl_list)) { 2544 /* there are still in flux knotes remaining */ 2545 kn = SLIST_FIRST(&knl->kl_list); 2546 kq = kn->kn_kq; 2547 KQ_LOCK(kq); 2548 KASSERT(kn_in_flux(kn), ("knote removed w/o list lock")); 2549 knl->kl_unlock(knl->kl_lockarg); 2550 kq->kq_state |= KQ_FLUXWAIT; 2551 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0); 2552 kq = NULL; 2553 goto again; 2554 } 2555 2556 if (islocked) 2557 KNL_ASSERT_LOCKED(knl); 2558 else { 2559 knl->kl_unlock(knl->kl_lockarg); 2560 KNL_ASSERT_UNLOCKED(knl); 2561 } 2562 } 2563 2564 /* 2565 * Remove all knotes referencing a specified fd must be called with FILEDESC 2566 * lock. This prevents a race where a new fd comes along and occupies the 2567 * entry and we attach a knote to the fd. 2568 */ 2569 void 2570 knote_fdclose(struct thread *td, int fd) 2571 { 2572 struct filedesc *fdp = td->td_proc->p_fd; 2573 struct kqueue *kq; 2574 struct knote *kn; 2575 int influx; 2576 2577 FILEDESC_XLOCK_ASSERT(fdp); 2578 2579 /* 2580 * We shouldn't have to worry about new kevents appearing on fd 2581 * since filedesc is locked. 2582 */ 2583 TAILQ_FOREACH(kq, &fdp->fd_kqlist, kq_list) { 2584 KQ_LOCK(kq); 2585 2586 again: 2587 influx = 0; 2588 while (kq->kq_knlistsize > fd && 2589 (kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) { 2590 if (kn_in_flux(kn)) { 2591 /* someone else might be waiting on our knote */ 2592 if (influx) 2593 wakeup(kq); 2594 kq->kq_state |= KQ_FLUXWAIT; 2595 msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0); 2596 goto again; 2597 } 2598 kn_enter_flux(kn); 2599 KQ_UNLOCK(kq); 2600 influx = 1; 2601 knote_drop(kn, td); 2602 KQ_LOCK(kq); 2603 } 2604 KQ_UNLOCK_FLUX(kq); 2605 } 2606 } 2607 2608 static int 2609 knote_attach(struct knote *kn, struct kqueue *kq) 2610 { 2611 struct klist *list; 2612 2613 KASSERT(kn_in_flux(kn), ("knote %p not marked influx", kn)); 2614 KQ_OWNED(kq); 2615 2616 if ((kq->kq_state & KQ_CLOSING) != 0) 2617 return (EBADF); 2618 if (kn->kn_fop->f_isfd) { 2619 if (kn->kn_id >= kq->kq_knlistsize) 2620 return (ENOMEM); 2621 list = &kq->kq_knlist[kn->kn_id]; 2622 } else { 2623 if (kq->kq_knhash == NULL) 2624 return (ENOMEM); 2625 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2626 } 2627 SLIST_INSERT_HEAD(list, kn, kn_link); 2628 return (0); 2629 } 2630 2631 static void 2632 knote_drop(struct knote *kn, struct thread *td) 2633 { 2634 2635 if ((kn->kn_status & KN_DETACHED) == 0) 2636 kn->kn_fop->f_detach(kn); 2637 knote_drop_detached(kn, td); 2638 } 2639 2640 static void 2641 knote_drop_detached(struct knote *kn, struct thread *td) 2642 { 2643 struct kqueue *kq; 2644 struct klist *list; 2645 2646 kq = kn->kn_kq; 2647 2648 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2649 ("knote %p still attached", kn)); 2650 KQ_NOTOWNED(kq); 2651 2652 KQ_LOCK(kq); 2653 KASSERT(kn->kn_influx == 1, 2654 ("knote_drop called on %p with influx %d", kn, kn->kn_influx)); 2655 2656 if (kn->kn_fop->f_isfd) 2657 list = &kq->kq_knlist[kn->kn_id]; 2658 else 2659 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2660 2661 if (!SLIST_EMPTY(list)) 2662 SLIST_REMOVE(list, kn, knote, kn_link); 2663 if (kn->kn_status & KN_QUEUED) 2664 knote_dequeue(kn); 2665 KQ_UNLOCK_FLUX(kq); 2666 2667 if (kn->kn_fop->f_isfd) { 2668 fdrop(kn->kn_fp, td); 2669 kn->kn_fp = NULL; 2670 } 2671 kqueue_fo_release(kn->kn_kevent.filter); 2672 kn->kn_fop = NULL; 2673 knote_free(kn); 2674 } 2675 2676 static void 2677 knote_enqueue(struct knote *kn) 2678 { 2679 struct kqueue *kq = kn->kn_kq; 2680 2681 KQ_OWNED(kn->kn_kq); 2682 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 2683 2684 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2685 kn->kn_status |= KN_QUEUED; 2686 kq->kq_count++; 2687 kqueue_wakeup(kq); 2688 } 2689 2690 static void 2691 knote_dequeue(struct knote *kn) 2692 { 2693 struct kqueue *kq = kn->kn_kq; 2694 2695 KQ_OWNED(kn->kn_kq); 2696 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 2697 2698 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 2699 kn->kn_status &= ~KN_QUEUED; 2700 kq->kq_count--; 2701 } 2702 2703 static void 2704 knote_init(void) 2705 { 2706 2707 knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL, 2708 NULL, NULL, UMA_ALIGN_PTR, 0); 2709 } 2710 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL); 2711 2712 static struct knote * 2713 knote_alloc(int waitok) 2714 { 2715 2716 return (uma_zalloc(knote_zone, (waitok ? M_WAITOK : M_NOWAIT) | 2717 M_ZERO)); 2718 } 2719 2720 static void 2721 knote_free(struct knote *kn) 2722 { 2723 2724 uma_zfree(knote_zone, kn); 2725 } 2726 2727 /* 2728 * Register the kev w/ the kq specified by fd. 2729 */ 2730 int 2731 kqfd_register(int fd, struct kevent *kev, struct thread *td, int waitok) 2732 { 2733 struct kqueue *kq; 2734 struct file *fp; 2735 cap_rights_t rights; 2736 int error; 2737 2738 error = fget(td, fd, cap_rights_init(&rights, CAP_KQUEUE_CHANGE), &fp); 2739 if (error != 0) 2740 return (error); 2741 if ((error = kqueue_acquire(fp, &kq)) != 0) 2742 goto noacquire; 2743 2744 error = kqueue_register(kq, kev, td, waitok); 2745 kqueue_release(kq, 0); 2746 2747 noacquire: 2748 fdrop(fp, td); 2749 return (error); 2750 }
Cache object: d6a94a06cb6bf058d019303c73e48a9c
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