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/limits.h> 46 #include <sys/lock.h> 47 #include <sys/mutex.h> 48 #include <sys/rwlock.h> 49 #include <sys/proc.h> 50 #include <sys/malloc.h> 51 #include <sys/unistd.h> 52 #include <sys/file.h> 53 #include <sys/filedesc.h> 54 #include <sys/filio.h> 55 #include <sys/fcntl.h> 56 #include <sys/kthread.h> 57 #include <sys/selinfo.h> 58 #include <sys/queue.h> 59 #include <sys/event.h> 60 #include <sys/eventvar.h> 61 #include <sys/poll.h> 62 #include <sys/protosw.h> 63 #include <sys/resourcevar.h> 64 #include <sys/sigio.h> 65 #include <sys/signalvar.h> 66 #include <sys/socket.h> 67 #include <sys/socketvar.h> 68 #include <sys/stat.h> 69 #include <sys/sysctl.h> 70 #include <sys/sysproto.h> 71 #include <sys/syscallsubr.h> 72 #include <sys/taskqueue.h> 73 #include <sys/uio.h> 74 #include <sys/user.h> 75 #ifdef KTRACE 76 #include <sys/ktrace.h> 77 #endif 78 #include <machine/atomic.h> 79 80 #include <vm/uma.h> 81 82 static MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system"); 83 84 /* 85 * This lock is used if multiple kq locks are required. This possibly 86 * should be made into a per proc lock. 87 */ 88 static struct mtx kq_global; 89 MTX_SYSINIT(kq_global, &kq_global, "kqueue order", MTX_DEF); 90 #define KQ_GLOBAL_LOCK(lck, haslck) do { \ 91 if (!haslck) \ 92 mtx_lock(lck); \ 93 haslck = 1; \ 94 } while (0) 95 #define KQ_GLOBAL_UNLOCK(lck, haslck) do { \ 96 if (haslck) \ 97 mtx_unlock(lck); \ 98 haslck = 0; \ 99 } while (0) 100 101 TASKQUEUE_DEFINE_THREAD(kqueue_ctx); 102 103 static int kevent_copyout(void *arg, struct kevent *kevp, int count); 104 static int kevent_copyin(void *arg, struct kevent *kevp, int count); 105 static int kqueue_register(struct kqueue *kq, struct kevent *kev, 106 struct thread *td, int mflag); 107 static int kqueue_acquire(struct file *fp, struct kqueue **kqp); 108 static void kqueue_release(struct kqueue *kq, int locked); 109 static void kqueue_destroy(struct kqueue *kq); 110 static void kqueue_drain(struct kqueue *kq, struct thread *td); 111 static int kqueue_expand(struct kqueue *kq, struct filterops *fops, 112 uintptr_t ident, int mflag); 113 static void kqueue_task(void *arg, int pending); 114 static int kqueue_scan(struct kqueue *kq, int maxevents, 115 struct kevent_copyops *k_ops, 116 const struct timespec *timeout, 117 struct kevent *keva, struct thread *td); 118 static void kqueue_wakeup(struct kqueue *kq); 119 static struct filterops *kqueue_fo_find(int filt); 120 static void kqueue_fo_release(int filt); 121 struct g_kevent_args; 122 static int kern_kevent_generic(struct thread *td, 123 struct g_kevent_args *uap, 124 struct kevent_copyops *k_ops, const char *struct_name); 125 126 static fo_ioctl_t kqueue_ioctl; 127 static fo_poll_t kqueue_poll; 128 static fo_kqfilter_t kqueue_kqfilter; 129 static fo_stat_t kqueue_stat; 130 static fo_close_t kqueue_close; 131 static fo_fill_kinfo_t kqueue_fill_kinfo; 132 133 static struct fileops kqueueops = { 134 .fo_read = invfo_rdwr, 135 .fo_write = invfo_rdwr, 136 .fo_truncate = invfo_truncate, 137 .fo_ioctl = kqueue_ioctl, 138 .fo_poll = kqueue_poll, 139 .fo_kqfilter = kqueue_kqfilter, 140 .fo_stat = kqueue_stat, 141 .fo_close = kqueue_close, 142 .fo_chmod = invfo_chmod, 143 .fo_chown = invfo_chown, 144 .fo_sendfile = invfo_sendfile, 145 .fo_fill_kinfo = kqueue_fill_kinfo, 146 }; 147 148 static int knote_attach(struct knote *kn, struct kqueue *kq); 149 static void knote_drop(struct knote *kn, struct thread *td); 150 static void knote_drop_detached(struct knote *kn, struct thread *td); 151 static void knote_enqueue(struct knote *kn); 152 static void knote_dequeue(struct knote *kn); 153 static void knote_init(void); 154 static struct knote *knote_alloc(int mflag); 155 static void knote_free(struct knote *kn); 156 157 static void filt_kqdetach(struct knote *kn); 158 static int filt_kqueue(struct knote *kn, long hint); 159 static int filt_procattach(struct knote *kn); 160 static void filt_procdetach(struct knote *kn); 161 static int filt_proc(struct knote *kn, long hint); 162 static int filt_fileattach(struct knote *kn); 163 static void filt_timerexpire(void *knx); 164 static int filt_timerattach(struct knote *kn); 165 static void filt_timerdetach(struct knote *kn); 166 static void filt_timerstart(struct knote *kn, sbintime_t to); 167 static void filt_timertouch(struct knote *kn, struct kevent *kev, 168 u_long type); 169 static int filt_timervalidate(struct knote *kn, sbintime_t *to); 170 static int filt_timer(struct knote *kn, long hint); 171 static int filt_userattach(struct knote *kn); 172 static void filt_userdetach(struct knote *kn); 173 static int filt_user(struct knote *kn, long hint); 174 static void filt_usertouch(struct knote *kn, struct kevent *kev, 175 u_long type); 176 177 static struct filterops file_filtops = { 178 .f_isfd = 1, 179 .f_attach = filt_fileattach, 180 }; 181 static struct filterops kqread_filtops = { 182 .f_isfd = 1, 183 .f_detach = filt_kqdetach, 184 .f_event = filt_kqueue, 185 }; 186 /* XXX - move to kern_proc.c? */ 187 static struct filterops proc_filtops = { 188 .f_isfd = 0, 189 .f_attach = filt_procattach, 190 .f_detach = filt_procdetach, 191 .f_event = filt_proc, 192 }; 193 static struct filterops timer_filtops = { 194 .f_isfd = 0, 195 .f_attach = filt_timerattach, 196 .f_detach = filt_timerdetach, 197 .f_event = filt_timer, 198 .f_touch = filt_timertouch, 199 }; 200 static struct filterops user_filtops = { 201 .f_attach = filt_userattach, 202 .f_detach = filt_userdetach, 203 .f_event = filt_user, 204 .f_touch = filt_usertouch, 205 }; 206 207 static uma_zone_t knote_zone; 208 static unsigned int kq_ncallouts = 0; 209 static unsigned int kq_calloutmax = 4 * 1024; 210 SYSCTL_UINT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW, 211 &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue"); 212 213 /* XXX - ensure not influx ? */ 214 #define KNOTE_ACTIVATE(kn, islock) do { \ 215 if ((islock)) \ 216 mtx_assert(&(kn)->kn_kq->kq_lock, MA_OWNED); \ 217 else \ 218 KQ_LOCK((kn)->kn_kq); \ 219 (kn)->kn_status |= KN_ACTIVE; \ 220 if (((kn)->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 221 knote_enqueue((kn)); \ 222 if (!(islock)) \ 223 KQ_UNLOCK((kn)->kn_kq); \ 224 } while(0) 225 #define KQ_LOCK(kq) do { \ 226 mtx_lock(&(kq)->kq_lock); \ 227 } while (0) 228 #define KQ_FLUX_WAKEUP(kq) do { \ 229 if (((kq)->kq_state & KQ_FLUXWAIT) == KQ_FLUXWAIT) { \ 230 (kq)->kq_state &= ~KQ_FLUXWAIT; \ 231 wakeup((kq)); \ 232 } \ 233 } while (0) 234 #define KQ_UNLOCK_FLUX(kq) do { \ 235 KQ_FLUX_WAKEUP(kq); \ 236 mtx_unlock(&(kq)->kq_lock); \ 237 } while (0) 238 #define KQ_UNLOCK(kq) do { \ 239 mtx_unlock(&(kq)->kq_lock); \ 240 } while (0) 241 #define KQ_OWNED(kq) do { \ 242 mtx_assert(&(kq)->kq_lock, MA_OWNED); \ 243 } while (0) 244 #define KQ_NOTOWNED(kq) do { \ 245 mtx_assert(&(kq)->kq_lock, MA_NOTOWNED); \ 246 } while (0) 247 248 static struct knlist * 249 kn_list_lock(struct knote *kn) 250 { 251 struct knlist *knl; 252 253 knl = kn->kn_knlist; 254 if (knl != NULL) 255 knl->kl_lock(knl->kl_lockarg); 256 return (knl); 257 } 258 259 static void 260 kn_list_unlock(struct knlist *knl) 261 { 262 bool do_free; 263 264 if (knl == NULL) 265 return; 266 do_free = knl->kl_autodestroy && knlist_empty(knl); 267 knl->kl_unlock(knl->kl_lockarg); 268 if (do_free) { 269 knlist_destroy(knl); 270 free(knl, M_KQUEUE); 271 } 272 } 273 274 static bool 275 kn_in_flux(struct knote *kn) 276 { 277 278 return (kn->kn_influx > 0); 279 } 280 281 static void 282 kn_enter_flux(struct knote *kn) 283 { 284 285 KQ_OWNED(kn->kn_kq); 286 MPASS(kn->kn_influx < INT_MAX); 287 kn->kn_influx++; 288 } 289 290 static bool 291 kn_leave_flux(struct knote *kn) 292 { 293 294 KQ_OWNED(kn->kn_kq); 295 MPASS(kn->kn_influx > 0); 296 kn->kn_influx--; 297 return (kn->kn_influx == 0); 298 } 299 300 #define KNL_ASSERT_LOCK(knl, islocked) do { \ 301 if (islocked) \ 302 KNL_ASSERT_LOCKED(knl); \ 303 else \ 304 KNL_ASSERT_UNLOCKED(knl); \ 305 } while (0) 306 #ifdef INVARIANTS 307 #define KNL_ASSERT_LOCKED(knl) do { \ 308 knl->kl_assert_lock((knl)->kl_lockarg, LA_LOCKED); \ 309 } while (0) 310 #define KNL_ASSERT_UNLOCKED(knl) do { \ 311 knl->kl_assert_lock((knl)->kl_lockarg, LA_UNLOCKED); \ 312 } while (0) 313 #else /* !INVARIANTS */ 314 #define KNL_ASSERT_LOCKED(knl) do {} while(0) 315 #define KNL_ASSERT_UNLOCKED(knl) do {} while (0) 316 #endif /* INVARIANTS */ 317 318 #ifndef KN_HASHSIZE 319 #define KN_HASHSIZE 64 /* XXX should be tunable */ 320 #endif 321 322 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 323 324 static int 325 filt_nullattach(struct knote *kn) 326 { 327 328 return (ENXIO); 329 }; 330 331 struct filterops null_filtops = { 332 .f_isfd = 0, 333 .f_attach = filt_nullattach, 334 }; 335 336 /* XXX - make SYSINIT to add these, and move into respective modules. */ 337 extern struct filterops sig_filtops; 338 extern struct filterops fs_filtops; 339 340 /* 341 * Table for for all system-defined filters. 342 */ 343 static struct mtx filterops_lock; 344 MTX_SYSINIT(kqueue_filterops, &filterops_lock, "protect sysfilt_ops", 345 MTX_DEF); 346 static struct { 347 struct filterops *for_fop; 348 int for_nolock; 349 int for_refcnt; 350 } sysfilt_ops[EVFILT_SYSCOUNT] = { 351 { &file_filtops, 1 }, /* EVFILT_READ */ 352 { &file_filtops, 1 }, /* EVFILT_WRITE */ 353 { &null_filtops }, /* EVFILT_AIO */ 354 { &file_filtops, 1 }, /* EVFILT_VNODE */ 355 { &proc_filtops, 1 }, /* EVFILT_PROC */ 356 { &sig_filtops, 1 }, /* EVFILT_SIGNAL */ 357 { &timer_filtops, 1 }, /* EVFILT_TIMER */ 358 { &file_filtops, 1 }, /* EVFILT_PROCDESC */ 359 { &fs_filtops, 1 }, /* EVFILT_FS */ 360 { &null_filtops }, /* EVFILT_LIO */ 361 { &user_filtops, 1 }, /* EVFILT_USER */ 362 { &null_filtops }, /* EVFILT_SENDFILE */ 363 { &file_filtops, 1 }, /* EVFILT_EMPTY */ 364 }; 365 366 /* 367 * Simple redirection for all cdevsw style objects to call their fo_kqfilter 368 * method. 369 */ 370 static int 371 filt_fileattach(struct knote *kn) 372 { 373 374 return (fo_kqfilter(kn->kn_fp, kn)); 375 } 376 377 /*ARGSUSED*/ 378 static int 379 kqueue_kqfilter(struct file *fp, struct knote *kn) 380 { 381 struct kqueue *kq = kn->kn_fp->f_data; 382 383 if (kn->kn_filter != EVFILT_READ) 384 return (EINVAL); 385 386 kn->kn_status |= KN_KQUEUE; 387 kn->kn_fop = &kqread_filtops; 388 knlist_add(&kq->kq_sel.si_note, kn, 0); 389 390 return (0); 391 } 392 393 static void 394 filt_kqdetach(struct knote *kn) 395 { 396 struct kqueue *kq = kn->kn_fp->f_data; 397 398 knlist_remove(&kq->kq_sel.si_note, kn, 0); 399 } 400 401 /*ARGSUSED*/ 402 static int 403 filt_kqueue(struct knote *kn, long hint) 404 { 405 struct kqueue *kq = kn->kn_fp->f_data; 406 407 kn->kn_data = kq->kq_count; 408 return (kn->kn_data > 0); 409 } 410 411 /* XXX - move to kern_proc.c? */ 412 static int 413 filt_procattach(struct knote *kn) 414 { 415 struct proc *p; 416 int error; 417 bool exiting, immediate; 418 419 exiting = immediate = false; 420 if (kn->kn_sfflags & NOTE_EXIT) 421 p = pfind_any(kn->kn_id); 422 else 423 p = pfind(kn->kn_id); 424 if (p == NULL) 425 return (ESRCH); 426 if (p->p_flag & P_WEXIT) 427 exiting = true; 428 429 if ((error = p_cansee(curthread, p))) { 430 PROC_UNLOCK(p); 431 return (error); 432 } 433 434 kn->kn_ptr.p_proc = p; 435 kn->kn_flags |= EV_CLEAR; /* automatically set */ 436 437 /* 438 * Internal flag indicating registration done by kernel for the 439 * purposes of getting a NOTE_CHILD notification. 440 */ 441 if (kn->kn_flags & EV_FLAG2) { 442 kn->kn_flags &= ~EV_FLAG2; 443 kn->kn_data = kn->kn_sdata; /* ppid */ 444 kn->kn_fflags = NOTE_CHILD; 445 kn->kn_sfflags &= ~(NOTE_EXIT | NOTE_EXEC | NOTE_FORK); 446 immediate = true; /* Force immediate activation of child note. */ 447 } 448 /* 449 * Internal flag indicating registration done by kernel (for other than 450 * NOTE_CHILD). 451 */ 452 if (kn->kn_flags & EV_FLAG1) { 453 kn->kn_flags &= ~EV_FLAG1; 454 } 455 456 knlist_add(p->p_klist, kn, 1); 457 458 /* 459 * Immediately activate any child notes or, in the case of a zombie 460 * target process, exit notes. The latter is necessary to handle the 461 * case where the target process, e.g. a child, dies before the kevent 462 * is registered. 463 */ 464 if (immediate || (exiting && filt_proc(kn, NOTE_EXIT))) 465 KNOTE_ACTIVATE(kn, 0); 466 467 PROC_UNLOCK(p); 468 469 return (0); 470 } 471 472 /* 473 * The knote may be attached to a different process, which may exit, 474 * leaving nothing for the knote to be attached to. So when the process 475 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 476 * it will be deleted when read out. However, as part of the knote deletion, 477 * this routine is called, so a check is needed to avoid actually performing 478 * a detach, because the original process does not exist any more. 479 */ 480 /* XXX - move to kern_proc.c? */ 481 static void 482 filt_procdetach(struct knote *kn) 483 { 484 485 knlist_remove(kn->kn_knlist, kn, 0); 486 kn->kn_ptr.p_proc = NULL; 487 } 488 489 /* XXX - move to kern_proc.c? */ 490 static int 491 filt_proc(struct knote *kn, long hint) 492 { 493 struct proc *p; 494 u_int event; 495 496 p = kn->kn_ptr.p_proc; 497 if (p == NULL) /* already activated, from attach filter */ 498 return (0); 499 500 /* Mask off extra data. */ 501 event = (u_int)hint & NOTE_PCTRLMASK; 502 503 /* If the user is interested in this event, record it. */ 504 if (kn->kn_sfflags & event) 505 kn->kn_fflags |= event; 506 507 /* Process is gone, so flag the event as finished. */ 508 if (event == NOTE_EXIT) { 509 kn->kn_flags |= EV_EOF | EV_ONESHOT; 510 kn->kn_ptr.p_proc = NULL; 511 if (kn->kn_fflags & NOTE_EXIT) 512 kn->kn_data = KW_EXITCODE(p->p_xexit, p->p_xsig); 513 if (kn->kn_fflags == 0) 514 kn->kn_flags |= EV_DROP; 515 return (1); 516 } 517 518 return (kn->kn_fflags != 0); 519 } 520 521 /* 522 * Called when the process forked. It mostly does the same as the 523 * knote(), activating all knotes registered to be activated when the 524 * process forked. Additionally, for each knote attached to the 525 * parent, check whether user wants to track the new process. If so 526 * attach a new knote to it, and immediately report an event with the 527 * child's pid. 528 */ 529 void 530 knote_fork(struct knlist *list, int pid) 531 { 532 struct kqueue *kq; 533 struct knote *kn; 534 struct kevent kev; 535 int error; 536 537 MPASS(list != NULL); 538 KNL_ASSERT_LOCKED(list); 539 if (SLIST_EMPTY(&list->kl_list)) 540 return; 541 542 memset(&kev, 0, sizeof(kev)); 543 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { 544 kq = kn->kn_kq; 545 KQ_LOCK(kq); 546 if (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0) { 547 KQ_UNLOCK(kq); 548 continue; 549 } 550 551 /* 552 * The same as knote(), activate the event. 553 */ 554 if ((kn->kn_sfflags & NOTE_TRACK) == 0) { 555 if (kn->kn_fop->f_event(kn, NOTE_FORK)) 556 KNOTE_ACTIVATE(kn, 1); 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, M_NOWAIT); 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, M_NOWAIT); 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 } 612 613 /* 614 * XXX: EVFILT_TIMER should perhaps live in kern_time.c beside the 615 * interval timer support code. 616 */ 617 618 #define NOTE_TIMER_PRECMASK \ 619 (NOTE_SECONDS | NOTE_MSECONDS | NOTE_USECONDS | NOTE_NSECONDS) 620 621 static sbintime_t 622 timer2sbintime(int64_t data, int flags) 623 { 624 int64_t secs; 625 626 /* 627 * Macros for converting to the fractional second portion of an 628 * sbintime_t using 64bit multiplication to improve precision. 629 */ 630 #define NS_TO_SBT(ns) (((ns) * (((uint64_t)1 << 63) / 500000000)) >> 32) 631 #define US_TO_SBT(us) (((us) * (((uint64_t)1 << 63) / 500000)) >> 32) 632 #define MS_TO_SBT(ms) (((ms) * (((uint64_t)1 << 63) / 500)) >> 32) 633 switch (flags & NOTE_TIMER_PRECMASK) { 634 case NOTE_SECONDS: 635 #ifdef __LP64__ 636 if (data > (SBT_MAX / SBT_1S)) 637 return (SBT_MAX); 638 #endif 639 return ((sbintime_t)data << 32); 640 case NOTE_MSECONDS: /* FALLTHROUGH */ 641 case 0: 642 if (data >= 1000) { 643 secs = data / 1000; 644 #ifdef __LP64__ 645 if (secs > (SBT_MAX / SBT_1S)) 646 return (SBT_MAX); 647 #endif 648 return (secs << 32 | MS_TO_SBT(data % 1000)); 649 } 650 return (MS_TO_SBT(data)); 651 case NOTE_USECONDS: 652 if (data >= 1000000) { 653 secs = data / 1000000; 654 #ifdef __LP64__ 655 if (secs > (SBT_MAX / SBT_1S)) 656 return (SBT_MAX); 657 #endif 658 return (secs << 32 | US_TO_SBT(data % 1000000)); 659 } 660 return (US_TO_SBT(data)); 661 case NOTE_NSECONDS: 662 if (data >= 1000000000) { 663 secs = data / 1000000000; 664 #ifdef __LP64__ 665 if (secs > (SBT_MAX / SBT_1S)) 666 return (SBT_MAX); 667 #endif 668 return (secs << 32 | NS_TO_SBT(data % 1000000000)); 669 } 670 return (NS_TO_SBT(data)); 671 default: 672 break; 673 } 674 return (-1); 675 } 676 677 struct kq_timer_cb_data { 678 struct callout c; 679 struct proc *p; 680 struct knote *kn; 681 int cpuid; 682 TAILQ_ENTRY(kq_timer_cb_data) link; 683 sbintime_t next; /* next timer event fires at */ 684 sbintime_t to; /* precalculated timer period, 0 for abs */ 685 }; 686 687 static void 688 kqtimer_sched_callout(struct kq_timer_cb_data *kc) 689 { 690 callout_reset_sbt_on(&kc->c, kc->next, 0, filt_timerexpire, kc->kn, 691 kc->cpuid, C_ABSOLUTE); 692 } 693 694 void 695 kqtimer_proc_continue(struct proc *p) 696 { 697 struct kq_timer_cb_data *kc, *kc1; 698 struct bintime bt; 699 sbintime_t now; 700 701 PROC_LOCK_ASSERT(p, MA_OWNED); 702 703 getboottimebin(&bt); 704 now = bttosbt(bt); 705 706 TAILQ_FOREACH_SAFE(kc, &p->p_kqtim_stop, link, kc1) { 707 TAILQ_REMOVE(&p->p_kqtim_stop, kc, link); 708 if (kc->next <= now) 709 filt_timerexpire(kc->kn); 710 else 711 kqtimer_sched_callout(kc); 712 } 713 } 714 715 static void 716 filt_timerexpire(void *knx) 717 { 718 struct knote *kn; 719 struct kq_timer_cb_data *kc; 720 struct proc *p; 721 sbintime_t now; 722 723 kn = knx; 724 kc = kn->kn_ptr.p_v; 725 726 if ((kn->kn_flags & EV_ONESHOT) != 0 || kc->to == 0) { 727 kn->kn_data++; 728 KNOTE_ACTIVATE(kn, 0); 729 return; 730 } 731 732 for (now = sbinuptime(); kc->next <= now; kc->next += kc->to) 733 kn->kn_data++; 734 KNOTE_ACTIVATE(kn, 0); /* XXX - handle locking */ 735 736 /* 737 * Initial check for stopped kc->p is racy. It is fine to 738 * miss the set of the stop flags, at worst we would schedule 739 * one more callout. On the other hand, it is not fine to not 740 * schedule when we we missed clearing of the flags, we 741 * recheck them under the lock and observe consistent state. 742 */ 743 p = kc->p; 744 if (P_SHOULDSTOP(p) || P_KILLED(p)) { 745 PROC_LOCK(p); 746 if (P_SHOULDSTOP(p) || P_KILLED(p)) { 747 TAILQ_INSERT_TAIL(&p->p_kqtim_stop, kc, link); 748 PROC_UNLOCK(p); 749 return; 750 } 751 PROC_UNLOCK(p); 752 } 753 kqtimer_sched_callout(kc); 754 } 755 756 /* 757 * data contains amount of time to sleep 758 */ 759 static int 760 filt_timervalidate(struct knote *kn, sbintime_t *to) 761 { 762 struct bintime bt; 763 sbintime_t sbt; 764 765 if (kn->kn_sdata < 0) 766 return (EINVAL); 767 if (kn->kn_sdata == 0 && (kn->kn_flags & EV_ONESHOT) == 0) 768 kn->kn_sdata = 1; 769 /* 770 * The only fflags values supported are the timer unit 771 * (precision) and the absolute time indicator. 772 */ 773 if ((kn->kn_sfflags & ~(NOTE_TIMER_PRECMASK | NOTE_ABSTIME)) != 0) 774 return (EINVAL); 775 776 *to = timer2sbintime(kn->kn_sdata, kn->kn_sfflags); 777 if ((kn->kn_sfflags & NOTE_ABSTIME) != 0) { 778 getboottimebin(&bt); 779 sbt = bttosbt(bt); 780 *to -= sbt; 781 } 782 if (*to < 0) 783 return (EINVAL); 784 return (0); 785 } 786 787 static int 788 filt_timerattach(struct knote *kn) 789 { 790 struct kq_timer_cb_data *kc; 791 sbintime_t to; 792 unsigned int ncallouts; 793 int error; 794 795 error = filt_timervalidate(kn, &to); 796 if (error != 0) 797 return (error); 798 799 do { 800 ncallouts = kq_ncallouts; 801 if (ncallouts >= kq_calloutmax) 802 return (ENOMEM); 803 } while (!atomic_cmpset_int(&kq_ncallouts, ncallouts, ncallouts + 1)); 804 805 if ((kn->kn_sfflags & NOTE_ABSTIME) == 0) 806 kn->kn_flags |= EV_CLEAR; /* automatically set */ 807 kn->kn_status &= ~KN_DETACHED; /* knlist_add clears it */ 808 kn->kn_ptr.p_v = kc = malloc(sizeof(*kc), M_KQUEUE, M_WAITOK); 809 kc->kn = kn; 810 kc->p = curproc; 811 kc->cpuid = PCPU_GET(cpuid); 812 callout_init(&kc->c, 1); 813 filt_timerstart(kn, to); 814 815 return (0); 816 } 817 818 static void 819 filt_timerstart(struct knote *kn, sbintime_t to) 820 { 821 struct kq_timer_cb_data *kc; 822 823 kc = kn->kn_ptr.p_v; 824 if ((kn->kn_sfflags & NOTE_ABSTIME) != 0) { 825 kc->next = to; 826 kc->to = 0; 827 } else { 828 kc->next = to + sbinuptime(); 829 kc->to = to; 830 } 831 kqtimer_sched_callout(kc); 832 } 833 834 static void 835 filt_timerdetach(struct knote *kn) 836 { 837 struct kq_timer_cb_data *kc; 838 unsigned int old __unused; 839 840 kc = kn->kn_ptr.p_v; 841 callout_drain(&kc->c); 842 free(kc, M_KQUEUE); 843 old = atomic_fetchadd_int(&kq_ncallouts, -1); 844 KASSERT(old > 0, ("Number of callouts cannot become negative")); 845 kn->kn_status |= KN_DETACHED; /* knlist_remove sets it */ 846 } 847 848 static void 849 filt_timertouch(struct knote *kn, struct kevent *kev, u_long type) 850 { 851 struct kq_timer_cb_data *kc; 852 struct kqueue *kq; 853 sbintime_t to; 854 int error; 855 856 switch (type) { 857 case EVENT_REGISTER: 858 /* Handle re-added timers that update data/fflags */ 859 if (kev->flags & EV_ADD) { 860 kc = kn->kn_ptr.p_v; 861 862 /* Drain any existing callout. */ 863 callout_drain(&kc->c); 864 865 /* Throw away any existing undelivered record 866 * of the timer expiration. This is done under 867 * the presumption that if a process is 868 * re-adding this timer with new parameters, 869 * it is no longer interested in what may have 870 * happened under the old parameters. If it is 871 * interested, it can wait for the expiration, 872 * delete the old timer definition, and then 873 * add the new one. 874 * 875 * This has to be done while the kq is locked: 876 * - if enqueued, dequeue 877 * - make it no longer active 878 * - clear the count of expiration events 879 */ 880 kq = kn->kn_kq; 881 KQ_LOCK(kq); 882 if (kn->kn_status & KN_QUEUED) 883 knote_dequeue(kn); 884 885 kn->kn_status &= ~KN_ACTIVE; 886 kn->kn_data = 0; 887 KQ_UNLOCK(kq); 888 889 /* Reschedule timer based on new data/fflags */ 890 kn->kn_sfflags = kev->fflags; 891 kn->kn_sdata = kev->data; 892 error = filt_timervalidate(kn, &to); 893 if (error != 0) { 894 kn->kn_flags |= EV_ERROR; 895 kn->kn_data = error; 896 } else 897 filt_timerstart(kn, to); 898 } 899 break; 900 901 case EVENT_PROCESS: 902 *kev = kn->kn_kevent; 903 if (kn->kn_flags & EV_CLEAR) { 904 kn->kn_data = 0; 905 kn->kn_fflags = 0; 906 } 907 break; 908 909 default: 910 panic("filt_timertouch() - invalid type (%ld)", type); 911 break; 912 } 913 } 914 915 static int 916 filt_timer(struct knote *kn, long hint) 917 { 918 919 return (kn->kn_data != 0); 920 } 921 922 static int 923 filt_userattach(struct knote *kn) 924 { 925 926 /* 927 * EVFILT_USER knotes are not attached to anything in the kernel. 928 */ 929 kn->kn_hook = NULL; 930 if (kn->kn_fflags & NOTE_TRIGGER) 931 kn->kn_hookid = 1; 932 else 933 kn->kn_hookid = 0; 934 return (0); 935 } 936 937 static void 938 filt_userdetach(__unused struct knote *kn) 939 { 940 941 /* 942 * EVFILT_USER knotes are not attached to anything in the kernel. 943 */ 944 } 945 946 static int 947 filt_user(struct knote *kn, __unused long hint) 948 { 949 950 return (kn->kn_hookid); 951 } 952 953 static void 954 filt_usertouch(struct knote *kn, struct kevent *kev, u_long type) 955 { 956 u_int ffctrl; 957 958 switch (type) { 959 case EVENT_REGISTER: 960 if (kev->fflags & NOTE_TRIGGER) 961 kn->kn_hookid = 1; 962 963 ffctrl = kev->fflags & NOTE_FFCTRLMASK; 964 kev->fflags &= NOTE_FFLAGSMASK; 965 switch (ffctrl) { 966 case NOTE_FFNOP: 967 break; 968 969 case NOTE_FFAND: 970 kn->kn_sfflags &= kev->fflags; 971 break; 972 973 case NOTE_FFOR: 974 kn->kn_sfflags |= kev->fflags; 975 break; 976 977 case NOTE_FFCOPY: 978 kn->kn_sfflags = kev->fflags; 979 break; 980 981 default: 982 /* XXX Return error? */ 983 break; 984 } 985 kn->kn_sdata = kev->data; 986 if (kev->flags & EV_CLEAR) { 987 kn->kn_hookid = 0; 988 kn->kn_data = 0; 989 kn->kn_fflags = 0; 990 } 991 break; 992 993 case EVENT_PROCESS: 994 *kev = kn->kn_kevent; 995 kev->fflags = kn->kn_sfflags; 996 kev->data = kn->kn_sdata; 997 if (kn->kn_flags & EV_CLEAR) { 998 kn->kn_hookid = 0; 999 kn->kn_data = 0; 1000 kn->kn_fflags = 0; 1001 } 1002 break; 1003 1004 default: 1005 panic("filt_usertouch() - invalid type (%ld)", type); 1006 break; 1007 } 1008 } 1009 1010 int 1011 sys_kqueue(struct thread *td, struct kqueue_args *uap) 1012 { 1013 1014 return (kern_kqueue(td, 0, NULL)); 1015 } 1016 1017 static void 1018 kqueue_init(struct kqueue *kq) 1019 { 1020 1021 mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF | MTX_DUPOK); 1022 TAILQ_INIT(&kq->kq_head); 1023 knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock); 1024 TASK_INIT(&kq->kq_task, 0, kqueue_task, kq); 1025 } 1026 1027 int 1028 kern_kqueue(struct thread *td, int flags, struct filecaps *fcaps) 1029 { 1030 struct filedesc *fdp; 1031 struct kqueue *kq; 1032 struct file *fp; 1033 struct ucred *cred; 1034 int fd, error; 1035 1036 fdp = td->td_proc->p_fd; 1037 cred = td->td_ucred; 1038 if (!chgkqcnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_KQUEUES))) 1039 return (ENOMEM); 1040 1041 error = falloc_caps(td, &fp, &fd, flags, fcaps); 1042 if (error != 0) { 1043 chgkqcnt(cred->cr_ruidinfo, -1, 0); 1044 return (error); 1045 } 1046 1047 /* An extra reference on `fp' has been held for us by falloc(). */ 1048 kq = malloc(sizeof *kq, M_KQUEUE, M_WAITOK | M_ZERO); 1049 kqueue_init(kq); 1050 kq->kq_fdp = fdp; 1051 kq->kq_cred = crhold(cred); 1052 1053 FILEDESC_XLOCK(fdp); 1054 TAILQ_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list); 1055 FILEDESC_XUNLOCK(fdp); 1056 1057 finit(fp, FREAD | FWRITE, DTYPE_KQUEUE, kq, &kqueueops); 1058 fdrop(fp, td); 1059 1060 td->td_retval[0] = fd; 1061 return (0); 1062 } 1063 1064 struct g_kevent_args { 1065 int fd; 1066 void *changelist; 1067 int nchanges; 1068 void *eventlist; 1069 int nevents; 1070 const struct timespec *timeout; 1071 }; 1072 1073 int 1074 sys_kevent(struct thread *td, struct kevent_args *uap) 1075 { 1076 struct kevent_copyops k_ops = { 1077 .arg = uap, 1078 .k_copyout = kevent_copyout, 1079 .k_copyin = kevent_copyin, 1080 .kevent_size = sizeof(struct kevent), 1081 }; 1082 struct g_kevent_args gk_args = { 1083 .fd = uap->fd, 1084 .changelist = uap->changelist, 1085 .nchanges = uap->nchanges, 1086 .eventlist = uap->eventlist, 1087 .nevents = uap->nevents, 1088 .timeout = uap->timeout, 1089 }; 1090 1091 return (kern_kevent_generic(td, &gk_args, &k_ops, "kevent")); 1092 } 1093 1094 static int 1095 kern_kevent_generic(struct thread *td, struct g_kevent_args *uap, 1096 struct kevent_copyops *k_ops, const char *struct_name) 1097 { 1098 struct timespec ts, *tsp; 1099 #ifdef KTRACE 1100 struct kevent *eventlist = uap->eventlist; 1101 #endif 1102 int error; 1103 1104 if (uap->timeout != NULL) { 1105 error = copyin(uap->timeout, &ts, sizeof(ts)); 1106 if (error) 1107 return (error); 1108 tsp = &ts; 1109 } else 1110 tsp = NULL; 1111 1112 #ifdef KTRACE 1113 if (KTRPOINT(td, KTR_STRUCT_ARRAY)) 1114 ktrstructarray(struct_name, UIO_USERSPACE, uap->changelist, 1115 uap->nchanges, k_ops->kevent_size); 1116 #endif 1117 1118 error = kern_kevent(td, uap->fd, uap->nchanges, uap->nevents, 1119 k_ops, tsp); 1120 1121 #ifdef KTRACE 1122 if (error == 0 && KTRPOINT(td, KTR_STRUCT_ARRAY)) 1123 ktrstructarray(struct_name, UIO_USERSPACE, eventlist, 1124 td->td_retval[0], k_ops->kevent_size); 1125 #endif 1126 1127 return (error); 1128 } 1129 1130 /* 1131 * Copy 'count' items into the destination list pointed to by uap->eventlist. 1132 */ 1133 static int 1134 kevent_copyout(void *arg, struct kevent *kevp, int count) 1135 { 1136 struct kevent_args *uap; 1137 int error; 1138 1139 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1140 uap = (struct kevent_args *)arg; 1141 1142 error = copyout(kevp, uap->eventlist, count * sizeof *kevp); 1143 if (error == 0) 1144 uap->eventlist += count; 1145 return (error); 1146 } 1147 1148 /* 1149 * Copy 'count' items from the list pointed to by uap->changelist. 1150 */ 1151 static int 1152 kevent_copyin(void *arg, struct kevent *kevp, int count) 1153 { 1154 struct kevent_args *uap; 1155 int error; 1156 1157 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1158 uap = (struct kevent_args *)arg; 1159 1160 error = copyin(uap->changelist, kevp, count * sizeof *kevp); 1161 if (error == 0) 1162 uap->changelist += count; 1163 return (error); 1164 } 1165 1166 #ifdef COMPAT_FREEBSD11 1167 static int 1168 kevent11_copyout(void *arg, struct kevent *kevp, int count) 1169 { 1170 struct freebsd11_kevent_args *uap; 1171 struct kevent_freebsd11 kev11; 1172 int error, i; 1173 1174 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1175 uap = (struct freebsd11_kevent_args *)arg; 1176 1177 for (i = 0; i < count; i++) { 1178 kev11.ident = kevp->ident; 1179 kev11.filter = kevp->filter; 1180 kev11.flags = kevp->flags; 1181 kev11.fflags = kevp->fflags; 1182 kev11.data = kevp->data; 1183 kev11.udata = kevp->udata; 1184 error = copyout(&kev11, uap->eventlist, sizeof(kev11)); 1185 if (error != 0) 1186 break; 1187 uap->eventlist++; 1188 kevp++; 1189 } 1190 return (error); 1191 } 1192 1193 /* 1194 * Copy 'count' items from the list pointed to by uap->changelist. 1195 */ 1196 static int 1197 kevent11_copyin(void *arg, struct kevent *kevp, int count) 1198 { 1199 struct freebsd11_kevent_args *uap; 1200 struct kevent_freebsd11 kev11; 1201 int error, i; 1202 1203 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1204 uap = (struct freebsd11_kevent_args *)arg; 1205 1206 for (i = 0; i < count; i++) { 1207 error = copyin(uap->changelist, &kev11, sizeof(kev11)); 1208 if (error != 0) 1209 break; 1210 kevp->ident = kev11.ident; 1211 kevp->filter = kev11.filter; 1212 kevp->flags = kev11.flags; 1213 kevp->fflags = kev11.fflags; 1214 kevp->data = (uintptr_t)kev11.data; 1215 kevp->udata = kev11.udata; 1216 bzero(&kevp->ext, sizeof(kevp->ext)); 1217 uap->changelist++; 1218 kevp++; 1219 } 1220 return (error); 1221 } 1222 1223 int 1224 freebsd11_kevent(struct thread *td, struct freebsd11_kevent_args *uap) 1225 { 1226 struct kevent_copyops k_ops = { 1227 .arg = uap, 1228 .k_copyout = kevent11_copyout, 1229 .k_copyin = kevent11_copyin, 1230 .kevent_size = sizeof(struct kevent_freebsd11), 1231 }; 1232 struct g_kevent_args gk_args = { 1233 .fd = uap->fd, 1234 .changelist = uap->changelist, 1235 .nchanges = uap->nchanges, 1236 .eventlist = uap->eventlist, 1237 .nevents = uap->nevents, 1238 .timeout = uap->timeout, 1239 }; 1240 1241 return (kern_kevent_generic(td, &gk_args, &k_ops, "kevent_freebsd11")); 1242 } 1243 #endif 1244 1245 int 1246 kern_kevent(struct thread *td, int fd, int nchanges, int nevents, 1247 struct kevent_copyops *k_ops, const struct timespec *timeout) 1248 { 1249 cap_rights_t rights; 1250 struct file *fp; 1251 int error; 1252 1253 cap_rights_init_zero(&rights); 1254 if (nchanges > 0) 1255 cap_rights_set_one(&rights, CAP_KQUEUE_CHANGE); 1256 if (nevents > 0) 1257 cap_rights_set_one(&rights, CAP_KQUEUE_EVENT); 1258 error = fget(td, fd, &rights, &fp); 1259 if (error != 0) 1260 return (error); 1261 1262 error = kern_kevent_fp(td, fp, nchanges, nevents, k_ops, timeout); 1263 fdrop(fp, td); 1264 1265 return (error); 1266 } 1267 1268 static int 1269 kqueue_kevent(struct kqueue *kq, struct thread *td, int nchanges, int nevents, 1270 struct kevent_copyops *k_ops, const struct timespec *timeout) 1271 { 1272 struct kevent keva[KQ_NEVENTS]; 1273 struct kevent *kevp, *changes; 1274 int i, n, nerrors, error; 1275 1276 nerrors = 0; 1277 while (nchanges > 0) { 1278 n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges; 1279 error = k_ops->k_copyin(k_ops->arg, keva, n); 1280 if (error) 1281 return (error); 1282 changes = keva; 1283 for (i = 0; i < n; i++) { 1284 kevp = &changes[i]; 1285 if (!kevp->filter) 1286 continue; 1287 kevp->flags &= ~EV_SYSFLAGS; 1288 error = kqueue_register(kq, kevp, td, M_WAITOK); 1289 if (error || (kevp->flags & EV_RECEIPT)) { 1290 if (nevents == 0) 1291 return (error); 1292 kevp->flags = EV_ERROR; 1293 kevp->data = error; 1294 (void)k_ops->k_copyout(k_ops->arg, kevp, 1); 1295 nevents--; 1296 nerrors++; 1297 } 1298 } 1299 nchanges -= n; 1300 } 1301 if (nerrors) { 1302 td->td_retval[0] = nerrors; 1303 return (0); 1304 } 1305 1306 return (kqueue_scan(kq, nevents, k_ops, timeout, keva, td)); 1307 } 1308 1309 int 1310 kern_kevent_fp(struct thread *td, struct file *fp, int nchanges, int nevents, 1311 struct kevent_copyops *k_ops, const struct timespec *timeout) 1312 { 1313 struct kqueue *kq; 1314 int error; 1315 1316 error = kqueue_acquire(fp, &kq); 1317 if (error != 0) 1318 return (error); 1319 error = kqueue_kevent(kq, td, nchanges, nevents, k_ops, timeout); 1320 kqueue_release(kq, 0); 1321 return (error); 1322 } 1323 1324 /* 1325 * Performs a kevent() call on a temporarily created kqueue. This can be 1326 * used to perform one-shot polling, similar to poll() and select(). 1327 */ 1328 int 1329 kern_kevent_anonymous(struct thread *td, int nevents, 1330 struct kevent_copyops *k_ops) 1331 { 1332 struct kqueue kq = {}; 1333 int error; 1334 1335 kqueue_init(&kq); 1336 kq.kq_refcnt = 1; 1337 error = kqueue_kevent(&kq, td, nevents, nevents, k_ops, NULL); 1338 kqueue_drain(&kq, td); 1339 kqueue_destroy(&kq); 1340 return (error); 1341 } 1342 1343 int 1344 kqueue_add_filteropts(int filt, struct filterops *filtops) 1345 { 1346 int error; 1347 1348 error = 0; 1349 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) { 1350 printf( 1351 "trying to add a filterop that is out of range: %d is beyond %d\n", 1352 ~filt, EVFILT_SYSCOUNT); 1353 return EINVAL; 1354 } 1355 mtx_lock(&filterops_lock); 1356 if (sysfilt_ops[~filt].for_fop != &null_filtops && 1357 sysfilt_ops[~filt].for_fop != NULL) 1358 error = EEXIST; 1359 else { 1360 sysfilt_ops[~filt].for_fop = filtops; 1361 sysfilt_ops[~filt].for_refcnt = 0; 1362 } 1363 mtx_unlock(&filterops_lock); 1364 1365 return (error); 1366 } 1367 1368 int 1369 kqueue_del_filteropts(int filt) 1370 { 1371 int error; 1372 1373 error = 0; 1374 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1375 return EINVAL; 1376 1377 mtx_lock(&filterops_lock); 1378 if (sysfilt_ops[~filt].for_fop == &null_filtops || 1379 sysfilt_ops[~filt].for_fop == NULL) 1380 error = EINVAL; 1381 else if (sysfilt_ops[~filt].for_refcnt != 0) 1382 error = EBUSY; 1383 else { 1384 sysfilt_ops[~filt].for_fop = &null_filtops; 1385 sysfilt_ops[~filt].for_refcnt = 0; 1386 } 1387 mtx_unlock(&filterops_lock); 1388 1389 return error; 1390 } 1391 1392 static struct filterops * 1393 kqueue_fo_find(int filt) 1394 { 1395 1396 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1397 return NULL; 1398 1399 if (sysfilt_ops[~filt].for_nolock) 1400 return sysfilt_ops[~filt].for_fop; 1401 1402 mtx_lock(&filterops_lock); 1403 sysfilt_ops[~filt].for_refcnt++; 1404 if (sysfilt_ops[~filt].for_fop == NULL) 1405 sysfilt_ops[~filt].for_fop = &null_filtops; 1406 mtx_unlock(&filterops_lock); 1407 1408 return sysfilt_ops[~filt].for_fop; 1409 } 1410 1411 static void 1412 kqueue_fo_release(int filt) 1413 { 1414 1415 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1416 return; 1417 1418 if (sysfilt_ops[~filt].for_nolock) 1419 return; 1420 1421 mtx_lock(&filterops_lock); 1422 KASSERT(sysfilt_ops[~filt].for_refcnt > 0, 1423 ("filter object refcount not valid on release")); 1424 sysfilt_ops[~filt].for_refcnt--; 1425 mtx_unlock(&filterops_lock); 1426 } 1427 1428 /* 1429 * A ref to kq (obtained via kqueue_acquire) must be held. 1430 */ 1431 static int 1432 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, 1433 int mflag) 1434 { 1435 struct filterops *fops; 1436 struct file *fp; 1437 struct knote *kn, *tkn; 1438 struct knlist *knl; 1439 int error, filt, event; 1440 int haskqglobal, filedesc_unlock; 1441 1442 if ((kev->flags & (EV_ENABLE | EV_DISABLE)) == (EV_ENABLE | EV_DISABLE)) 1443 return (EINVAL); 1444 1445 fp = NULL; 1446 kn = NULL; 1447 knl = NULL; 1448 error = 0; 1449 haskqglobal = 0; 1450 filedesc_unlock = 0; 1451 1452 filt = kev->filter; 1453 fops = kqueue_fo_find(filt); 1454 if (fops == NULL) 1455 return EINVAL; 1456 1457 if (kev->flags & EV_ADD) { 1458 /* 1459 * Prevent waiting with locks. Non-sleepable 1460 * allocation failures are handled in the loop, only 1461 * if the spare knote appears to be actually required. 1462 */ 1463 tkn = knote_alloc(mflag); 1464 } else { 1465 tkn = NULL; 1466 } 1467 1468 findkn: 1469 if (fops->f_isfd) { 1470 KASSERT(td != NULL, ("td is NULL")); 1471 if (kev->ident > INT_MAX) 1472 error = EBADF; 1473 else 1474 error = fget(td, kev->ident, &cap_event_rights, &fp); 1475 if (error) 1476 goto done; 1477 1478 if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops, 1479 kev->ident, M_NOWAIT) != 0) { 1480 /* try again */ 1481 fdrop(fp, td); 1482 fp = NULL; 1483 error = kqueue_expand(kq, fops, kev->ident, mflag); 1484 if (error) 1485 goto done; 1486 goto findkn; 1487 } 1488 1489 if (fp->f_type == DTYPE_KQUEUE) { 1490 /* 1491 * If we add some intelligence about what we are doing, 1492 * we should be able to support events on ourselves. 1493 * We need to know when we are doing this to prevent 1494 * getting both the knlist lock and the kq lock since 1495 * they are the same thing. 1496 */ 1497 if (fp->f_data == kq) { 1498 error = EINVAL; 1499 goto done; 1500 } 1501 1502 /* 1503 * Pre-lock the filedesc before the global 1504 * lock mutex, see the comment in 1505 * kqueue_close(). 1506 */ 1507 FILEDESC_XLOCK(td->td_proc->p_fd); 1508 filedesc_unlock = 1; 1509 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1510 } 1511 1512 KQ_LOCK(kq); 1513 if (kev->ident < kq->kq_knlistsize) { 1514 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link) 1515 if (kev->filter == kn->kn_filter) 1516 break; 1517 } 1518 } else { 1519 if ((kev->flags & EV_ADD) == EV_ADD) { 1520 error = kqueue_expand(kq, fops, kev->ident, mflag); 1521 if (error != 0) 1522 goto done; 1523 } 1524 1525 KQ_LOCK(kq); 1526 1527 /* 1528 * If possible, find an existing knote to use for this kevent. 1529 */ 1530 if (kev->filter == EVFILT_PROC && 1531 (kev->flags & (EV_FLAG1 | EV_FLAG2)) != 0) { 1532 /* This is an internal creation of a process tracking 1533 * note. Don't attempt to coalesce this with an 1534 * existing note. 1535 */ 1536 ; 1537 } else if (kq->kq_knhashmask != 0) { 1538 struct klist *list; 1539 1540 list = &kq->kq_knhash[ 1541 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)]; 1542 SLIST_FOREACH(kn, list, kn_link) 1543 if (kev->ident == kn->kn_id && 1544 kev->filter == kn->kn_filter) 1545 break; 1546 } 1547 } 1548 1549 /* knote is in the process of changing, wait for it to stabilize. */ 1550 if (kn != NULL && kn_in_flux(kn)) { 1551 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1552 if (filedesc_unlock) { 1553 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1554 filedesc_unlock = 0; 1555 } 1556 kq->kq_state |= KQ_FLUXWAIT; 1557 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0); 1558 if (fp != NULL) { 1559 fdrop(fp, td); 1560 fp = NULL; 1561 } 1562 goto findkn; 1563 } 1564 1565 /* 1566 * kn now contains the matching knote, or NULL if no match 1567 */ 1568 if (kn == NULL) { 1569 if (kev->flags & EV_ADD) { 1570 kn = tkn; 1571 tkn = NULL; 1572 if (kn == NULL) { 1573 KQ_UNLOCK(kq); 1574 error = ENOMEM; 1575 goto done; 1576 } 1577 kn->kn_fp = fp; 1578 kn->kn_kq = kq; 1579 kn->kn_fop = fops; 1580 /* 1581 * apply reference counts to knote structure, and 1582 * do not release it at the end of this routine. 1583 */ 1584 fops = NULL; 1585 fp = NULL; 1586 1587 kn->kn_sfflags = kev->fflags; 1588 kn->kn_sdata = kev->data; 1589 kev->fflags = 0; 1590 kev->data = 0; 1591 kn->kn_kevent = *kev; 1592 kn->kn_kevent.flags &= ~(EV_ADD | EV_DELETE | 1593 EV_ENABLE | EV_DISABLE | EV_FORCEONESHOT); 1594 kn->kn_status = KN_DETACHED; 1595 if ((kev->flags & EV_DISABLE) != 0) 1596 kn->kn_status |= KN_DISABLED; 1597 kn_enter_flux(kn); 1598 1599 error = knote_attach(kn, kq); 1600 KQ_UNLOCK(kq); 1601 if (error != 0) { 1602 tkn = kn; 1603 goto done; 1604 } 1605 1606 if ((error = kn->kn_fop->f_attach(kn)) != 0) { 1607 knote_drop_detached(kn, td); 1608 goto done; 1609 } 1610 knl = kn_list_lock(kn); 1611 goto done_ev_add; 1612 } else { 1613 /* No matching knote and the EV_ADD flag is not set. */ 1614 KQ_UNLOCK(kq); 1615 error = ENOENT; 1616 goto done; 1617 } 1618 } 1619 1620 if (kev->flags & EV_DELETE) { 1621 kn_enter_flux(kn); 1622 KQ_UNLOCK(kq); 1623 knote_drop(kn, td); 1624 goto done; 1625 } 1626 1627 if (kev->flags & EV_FORCEONESHOT) { 1628 kn->kn_flags |= EV_ONESHOT; 1629 KNOTE_ACTIVATE(kn, 1); 1630 } 1631 1632 if ((kev->flags & EV_ENABLE) != 0) 1633 kn->kn_status &= ~KN_DISABLED; 1634 else if ((kev->flags & EV_DISABLE) != 0) 1635 kn->kn_status |= KN_DISABLED; 1636 1637 /* 1638 * The user may change some filter values after the initial EV_ADD, 1639 * but doing so will not reset any filter which has already been 1640 * triggered. 1641 */ 1642 kn->kn_status |= KN_SCAN; 1643 kn_enter_flux(kn); 1644 KQ_UNLOCK(kq); 1645 knl = kn_list_lock(kn); 1646 kn->kn_kevent.udata = kev->udata; 1647 if (!fops->f_isfd && fops->f_touch != NULL) { 1648 fops->f_touch(kn, kev, EVENT_REGISTER); 1649 } else { 1650 kn->kn_sfflags = kev->fflags; 1651 kn->kn_sdata = kev->data; 1652 } 1653 1654 done_ev_add: 1655 /* 1656 * We can get here with kn->kn_knlist == NULL. This can happen when 1657 * the initial attach event decides that the event is "completed" 1658 * already, e.g., filt_procattach() is called on a zombie process. It 1659 * will call filt_proc() which will remove it from the list, and NULL 1660 * kn_knlist. 1661 * 1662 * KN_DISABLED will be stable while the knote is in flux, so the 1663 * unlocked read will not race with an update. 1664 */ 1665 if ((kn->kn_status & KN_DISABLED) == 0) 1666 event = kn->kn_fop->f_event(kn, 0); 1667 else 1668 event = 0; 1669 1670 KQ_LOCK(kq); 1671 if (event) 1672 kn->kn_status |= KN_ACTIVE; 1673 if ((kn->kn_status & (KN_ACTIVE | KN_DISABLED | KN_QUEUED)) == 1674 KN_ACTIVE) 1675 knote_enqueue(kn); 1676 kn->kn_status &= ~KN_SCAN; 1677 kn_leave_flux(kn); 1678 kn_list_unlock(knl); 1679 KQ_UNLOCK_FLUX(kq); 1680 1681 done: 1682 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1683 if (filedesc_unlock) 1684 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1685 if (fp != NULL) 1686 fdrop(fp, td); 1687 knote_free(tkn); 1688 if (fops != NULL) 1689 kqueue_fo_release(filt); 1690 return (error); 1691 } 1692 1693 static int 1694 kqueue_acquire(struct file *fp, struct kqueue **kqp) 1695 { 1696 int error; 1697 struct kqueue *kq; 1698 1699 error = 0; 1700 1701 kq = fp->f_data; 1702 if (fp->f_type != DTYPE_KQUEUE || kq == NULL) 1703 return (EBADF); 1704 *kqp = kq; 1705 KQ_LOCK(kq); 1706 if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) { 1707 KQ_UNLOCK(kq); 1708 return (EBADF); 1709 } 1710 kq->kq_refcnt++; 1711 KQ_UNLOCK(kq); 1712 1713 return error; 1714 } 1715 1716 static void 1717 kqueue_release(struct kqueue *kq, int locked) 1718 { 1719 if (locked) 1720 KQ_OWNED(kq); 1721 else 1722 KQ_LOCK(kq); 1723 kq->kq_refcnt--; 1724 if (kq->kq_refcnt == 1) 1725 wakeup(&kq->kq_refcnt); 1726 if (!locked) 1727 KQ_UNLOCK(kq); 1728 } 1729 1730 static void 1731 kqueue_schedtask(struct kqueue *kq) 1732 { 1733 1734 KQ_OWNED(kq); 1735 KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN), 1736 ("scheduling kqueue task while draining")); 1737 1738 if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) { 1739 taskqueue_enqueue(taskqueue_kqueue_ctx, &kq->kq_task); 1740 kq->kq_state |= KQ_TASKSCHED; 1741 } 1742 } 1743 1744 /* 1745 * Expand the kq to make sure we have storage for fops/ident pair. 1746 * 1747 * Return 0 on success (or no work necessary), return errno on failure. 1748 */ 1749 static int 1750 kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident, 1751 int mflag) 1752 { 1753 struct klist *list, *tmp_knhash, *to_free; 1754 u_long tmp_knhashmask; 1755 int error, fd, size; 1756 1757 KQ_NOTOWNED(kq); 1758 1759 error = 0; 1760 to_free = NULL; 1761 if (fops->f_isfd) { 1762 fd = ident; 1763 if (kq->kq_knlistsize <= fd) { 1764 size = kq->kq_knlistsize; 1765 while (size <= fd) 1766 size += KQEXTENT; 1767 list = malloc(size * sizeof(*list), M_KQUEUE, mflag); 1768 if (list == NULL) 1769 return ENOMEM; 1770 KQ_LOCK(kq); 1771 if ((kq->kq_state & KQ_CLOSING) != 0) { 1772 to_free = list; 1773 error = EBADF; 1774 } else if (kq->kq_knlistsize > fd) { 1775 to_free = list; 1776 } else { 1777 if (kq->kq_knlist != NULL) { 1778 bcopy(kq->kq_knlist, list, 1779 kq->kq_knlistsize * sizeof(*list)); 1780 to_free = kq->kq_knlist; 1781 kq->kq_knlist = NULL; 1782 } 1783 bzero((caddr_t)list + 1784 kq->kq_knlistsize * sizeof(*list), 1785 (size - kq->kq_knlistsize) * sizeof(*list)); 1786 kq->kq_knlistsize = size; 1787 kq->kq_knlist = list; 1788 } 1789 KQ_UNLOCK(kq); 1790 } 1791 } else { 1792 if (kq->kq_knhashmask == 0) { 1793 tmp_knhash = hashinit_flags(KN_HASHSIZE, M_KQUEUE, 1794 &tmp_knhashmask, (mflag & M_WAITOK) != 0 ? 1795 HASH_WAITOK : HASH_NOWAIT); 1796 if (tmp_knhash == NULL) 1797 return (ENOMEM); 1798 KQ_LOCK(kq); 1799 if ((kq->kq_state & KQ_CLOSING) != 0) { 1800 to_free = tmp_knhash; 1801 error = EBADF; 1802 } else if (kq->kq_knhashmask == 0) { 1803 kq->kq_knhash = tmp_knhash; 1804 kq->kq_knhashmask = tmp_knhashmask; 1805 } else { 1806 to_free = tmp_knhash; 1807 } 1808 KQ_UNLOCK(kq); 1809 } 1810 } 1811 free(to_free, M_KQUEUE); 1812 1813 KQ_NOTOWNED(kq); 1814 return (error); 1815 } 1816 1817 static void 1818 kqueue_task(void *arg, int pending) 1819 { 1820 struct kqueue *kq; 1821 int haskqglobal; 1822 1823 haskqglobal = 0; 1824 kq = arg; 1825 1826 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1827 KQ_LOCK(kq); 1828 1829 KNOTE_LOCKED(&kq->kq_sel.si_note, 0); 1830 1831 kq->kq_state &= ~KQ_TASKSCHED; 1832 if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) { 1833 wakeup(&kq->kq_state); 1834 } 1835 KQ_UNLOCK(kq); 1836 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1837 } 1838 1839 /* 1840 * Scan, update kn_data (if not ONESHOT), and copyout triggered events. 1841 * We treat KN_MARKER knotes as if they are in flux. 1842 */ 1843 static int 1844 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops, 1845 const struct timespec *tsp, struct kevent *keva, struct thread *td) 1846 { 1847 struct kevent *kevp; 1848 struct knote *kn, *marker; 1849 struct knlist *knl; 1850 sbintime_t asbt, rsbt; 1851 int count, error, haskqglobal, influx, nkev, touch; 1852 1853 count = maxevents; 1854 nkev = 0; 1855 error = 0; 1856 haskqglobal = 0; 1857 1858 if (maxevents == 0) 1859 goto done_nl; 1860 1861 rsbt = 0; 1862 if (tsp != NULL) { 1863 if (tsp->tv_sec < 0 || tsp->tv_nsec < 0 || 1864 tsp->tv_nsec >= 1000000000) { 1865 error = EINVAL; 1866 goto done_nl; 1867 } 1868 if (timespecisset(tsp)) { 1869 if (tsp->tv_sec <= INT32_MAX) { 1870 rsbt = tstosbt(*tsp); 1871 if (TIMESEL(&asbt, rsbt)) 1872 asbt += tc_tick_sbt; 1873 if (asbt <= SBT_MAX - rsbt) 1874 asbt += rsbt; 1875 else 1876 asbt = 0; 1877 rsbt >>= tc_precexp; 1878 } else 1879 asbt = 0; 1880 } else 1881 asbt = -1; 1882 } else 1883 asbt = 0; 1884 marker = knote_alloc(M_WAITOK); 1885 marker->kn_status = KN_MARKER; 1886 KQ_LOCK(kq); 1887 1888 retry: 1889 kevp = keva; 1890 if (kq->kq_count == 0) { 1891 if (asbt == -1) { 1892 error = EWOULDBLOCK; 1893 } else { 1894 kq->kq_state |= KQ_SLEEP; 1895 error = msleep_sbt(kq, &kq->kq_lock, PSOCK | PCATCH, 1896 "kqread", asbt, rsbt, C_ABSOLUTE); 1897 } 1898 if (error == 0) 1899 goto retry; 1900 /* don't restart after signals... */ 1901 if (error == ERESTART) 1902 error = EINTR; 1903 else if (error == EWOULDBLOCK) 1904 error = 0; 1905 goto done; 1906 } 1907 1908 TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); 1909 influx = 0; 1910 while (count) { 1911 KQ_OWNED(kq); 1912 kn = TAILQ_FIRST(&kq->kq_head); 1913 1914 if ((kn->kn_status == KN_MARKER && kn != marker) || 1915 kn_in_flux(kn)) { 1916 if (influx) { 1917 influx = 0; 1918 KQ_FLUX_WAKEUP(kq); 1919 } 1920 kq->kq_state |= KQ_FLUXWAIT; 1921 error = msleep(kq, &kq->kq_lock, PSOCK, 1922 "kqflxwt", 0); 1923 continue; 1924 } 1925 1926 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1927 if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) { 1928 kn->kn_status &= ~KN_QUEUED; 1929 kq->kq_count--; 1930 continue; 1931 } 1932 if (kn == marker) { 1933 KQ_FLUX_WAKEUP(kq); 1934 if (count == maxevents) 1935 goto retry; 1936 goto done; 1937 } 1938 KASSERT(!kn_in_flux(kn), 1939 ("knote %p is unexpectedly in flux", kn)); 1940 1941 if ((kn->kn_flags & EV_DROP) == EV_DROP) { 1942 kn->kn_status &= ~KN_QUEUED; 1943 kn_enter_flux(kn); 1944 kq->kq_count--; 1945 KQ_UNLOCK(kq); 1946 /* 1947 * We don't need to lock the list since we've 1948 * marked it as in flux. 1949 */ 1950 knote_drop(kn, td); 1951 KQ_LOCK(kq); 1952 continue; 1953 } else if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) { 1954 kn->kn_status &= ~KN_QUEUED; 1955 kn_enter_flux(kn); 1956 kq->kq_count--; 1957 KQ_UNLOCK(kq); 1958 /* 1959 * We don't need to lock the list since we've 1960 * marked the knote as being in flux. 1961 */ 1962 *kevp = kn->kn_kevent; 1963 knote_drop(kn, td); 1964 KQ_LOCK(kq); 1965 kn = NULL; 1966 } else { 1967 kn->kn_status |= KN_SCAN; 1968 kn_enter_flux(kn); 1969 KQ_UNLOCK(kq); 1970 if ((kn->kn_status & KN_KQUEUE) == KN_KQUEUE) 1971 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1972 knl = kn_list_lock(kn); 1973 if (kn->kn_fop->f_event(kn, 0) == 0) { 1974 KQ_LOCK(kq); 1975 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1976 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE | 1977 KN_SCAN); 1978 kn_leave_flux(kn); 1979 kq->kq_count--; 1980 kn_list_unlock(knl); 1981 influx = 1; 1982 continue; 1983 } 1984 touch = (!kn->kn_fop->f_isfd && 1985 kn->kn_fop->f_touch != NULL); 1986 if (touch) 1987 kn->kn_fop->f_touch(kn, kevp, EVENT_PROCESS); 1988 else 1989 *kevp = kn->kn_kevent; 1990 KQ_LOCK(kq); 1991 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1992 if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) { 1993 /* 1994 * Manually clear knotes who weren't 1995 * 'touch'ed. 1996 */ 1997 if (touch == 0 && kn->kn_flags & EV_CLEAR) { 1998 kn->kn_data = 0; 1999 kn->kn_fflags = 0; 2000 } 2001 if (kn->kn_flags & EV_DISPATCH) 2002 kn->kn_status |= KN_DISABLED; 2003 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 2004 kq->kq_count--; 2005 } else 2006 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2007 2008 kn->kn_status &= ~KN_SCAN; 2009 kn_leave_flux(kn); 2010 kn_list_unlock(knl); 2011 influx = 1; 2012 } 2013 2014 /* we are returning a copy to the user */ 2015 kevp++; 2016 nkev++; 2017 count--; 2018 2019 if (nkev == KQ_NEVENTS) { 2020 influx = 0; 2021 KQ_UNLOCK_FLUX(kq); 2022 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 2023 nkev = 0; 2024 kevp = keva; 2025 KQ_LOCK(kq); 2026 if (error) 2027 break; 2028 } 2029 } 2030 TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); 2031 done: 2032 KQ_OWNED(kq); 2033 KQ_UNLOCK_FLUX(kq); 2034 knote_free(marker); 2035 done_nl: 2036 KQ_NOTOWNED(kq); 2037 if (nkev != 0) 2038 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 2039 td->td_retval[0] = maxevents - count; 2040 return (error); 2041 } 2042 2043 /*ARGSUSED*/ 2044 static int 2045 kqueue_ioctl(struct file *fp, u_long cmd, void *data, 2046 struct ucred *active_cred, struct thread *td) 2047 { 2048 /* 2049 * Enabling sigio causes two major problems: 2050 * 1) infinite recursion: 2051 * Synopsys: kevent is being used to track signals and have FIOASYNC 2052 * set. On receipt of a signal this will cause a kqueue to recurse 2053 * into itself over and over. Sending the sigio causes the kqueue 2054 * to become ready, which in turn posts sigio again, forever. 2055 * Solution: this can be solved by setting a flag in the kqueue that 2056 * we have a SIGIO in progress. 2057 * 2) locking problems: 2058 * Synopsys: Kqueue is a leaf subsystem, but adding signalling puts 2059 * us above the proc and pgrp locks. 2060 * Solution: Post a signal using an async mechanism, being sure to 2061 * record a generation count in the delivery so that we do not deliver 2062 * a signal to the wrong process. 2063 * 2064 * Note, these two mechanisms are somewhat mutually exclusive! 2065 */ 2066 #if 0 2067 struct kqueue *kq; 2068 2069 kq = fp->f_data; 2070 switch (cmd) { 2071 case FIOASYNC: 2072 if (*(int *)data) { 2073 kq->kq_state |= KQ_ASYNC; 2074 } else { 2075 kq->kq_state &= ~KQ_ASYNC; 2076 } 2077 return (0); 2078 2079 case FIOSETOWN: 2080 return (fsetown(*(int *)data, &kq->kq_sigio)); 2081 2082 case FIOGETOWN: 2083 *(int *)data = fgetown(&kq->kq_sigio); 2084 return (0); 2085 } 2086 #endif 2087 2088 return (ENOTTY); 2089 } 2090 2091 /*ARGSUSED*/ 2092 static int 2093 kqueue_poll(struct file *fp, int events, struct ucred *active_cred, 2094 struct thread *td) 2095 { 2096 struct kqueue *kq; 2097 int revents = 0; 2098 int error; 2099 2100 if ((error = kqueue_acquire(fp, &kq))) 2101 return POLLERR; 2102 2103 KQ_LOCK(kq); 2104 if (events & (POLLIN | POLLRDNORM)) { 2105 if (kq->kq_count) { 2106 revents |= events & (POLLIN | POLLRDNORM); 2107 } else { 2108 selrecord(td, &kq->kq_sel); 2109 if (SEL_WAITING(&kq->kq_sel)) 2110 kq->kq_state |= KQ_SEL; 2111 } 2112 } 2113 kqueue_release(kq, 1); 2114 KQ_UNLOCK(kq); 2115 return (revents); 2116 } 2117 2118 /*ARGSUSED*/ 2119 static int 2120 kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred, 2121 struct thread *td) 2122 { 2123 2124 bzero((void *)st, sizeof *st); 2125 /* 2126 * We no longer return kq_count because the unlocked value is useless. 2127 * If you spent all this time getting the count, why not spend your 2128 * syscall better by calling kevent? 2129 * 2130 * XXX - This is needed for libc_r. 2131 */ 2132 st->st_mode = S_IFIFO; 2133 return (0); 2134 } 2135 2136 static void 2137 kqueue_drain(struct kqueue *kq, struct thread *td) 2138 { 2139 struct knote *kn; 2140 int i; 2141 2142 KQ_LOCK(kq); 2143 2144 KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING, 2145 ("kqueue already closing")); 2146 kq->kq_state |= KQ_CLOSING; 2147 if (kq->kq_refcnt > 1) 2148 msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0); 2149 2150 KASSERT(kq->kq_refcnt == 1, ("other refs are out there!")); 2151 2152 KASSERT(knlist_empty(&kq->kq_sel.si_note), 2153 ("kqueue's knlist not empty")); 2154 2155 for (i = 0; i < kq->kq_knlistsize; i++) { 2156 while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) { 2157 if (kn_in_flux(kn)) { 2158 kq->kq_state |= KQ_FLUXWAIT; 2159 msleep(kq, &kq->kq_lock, PSOCK, "kqclo1", 0); 2160 continue; 2161 } 2162 kn_enter_flux(kn); 2163 KQ_UNLOCK(kq); 2164 knote_drop(kn, td); 2165 KQ_LOCK(kq); 2166 } 2167 } 2168 if (kq->kq_knhashmask != 0) { 2169 for (i = 0; i <= kq->kq_knhashmask; i++) { 2170 while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) { 2171 if (kn_in_flux(kn)) { 2172 kq->kq_state |= KQ_FLUXWAIT; 2173 msleep(kq, &kq->kq_lock, PSOCK, 2174 "kqclo2", 0); 2175 continue; 2176 } 2177 kn_enter_flux(kn); 2178 KQ_UNLOCK(kq); 2179 knote_drop(kn, td); 2180 KQ_LOCK(kq); 2181 } 2182 } 2183 } 2184 2185 if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) { 2186 kq->kq_state |= KQ_TASKDRAIN; 2187 msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0); 2188 } 2189 2190 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2191 selwakeuppri(&kq->kq_sel, PSOCK); 2192 if (!SEL_WAITING(&kq->kq_sel)) 2193 kq->kq_state &= ~KQ_SEL; 2194 } 2195 2196 KQ_UNLOCK(kq); 2197 } 2198 2199 static void 2200 kqueue_destroy(struct kqueue *kq) 2201 { 2202 2203 KASSERT(kq->kq_fdp == NULL, 2204 ("kqueue still attached to a file descriptor")); 2205 seldrain(&kq->kq_sel); 2206 knlist_destroy(&kq->kq_sel.si_note); 2207 mtx_destroy(&kq->kq_lock); 2208 2209 if (kq->kq_knhash != NULL) 2210 free(kq->kq_knhash, M_KQUEUE); 2211 if (kq->kq_knlist != NULL) 2212 free(kq->kq_knlist, M_KQUEUE); 2213 2214 funsetown(&kq->kq_sigio); 2215 } 2216 2217 /*ARGSUSED*/ 2218 static int 2219 kqueue_close(struct file *fp, struct thread *td) 2220 { 2221 struct kqueue *kq = fp->f_data; 2222 struct filedesc *fdp; 2223 int error; 2224 int filedesc_unlock; 2225 2226 if ((error = kqueue_acquire(fp, &kq))) 2227 return error; 2228 kqueue_drain(kq, td); 2229 2230 /* 2231 * We could be called due to the knote_drop() doing fdrop(), 2232 * called from kqueue_register(). In this case the global 2233 * lock is owned, and filedesc sx is locked before, to not 2234 * take the sleepable lock after non-sleepable. 2235 */ 2236 fdp = kq->kq_fdp; 2237 kq->kq_fdp = NULL; 2238 if (!sx_xlocked(FILEDESC_LOCK(fdp))) { 2239 FILEDESC_XLOCK(fdp); 2240 filedesc_unlock = 1; 2241 } else 2242 filedesc_unlock = 0; 2243 TAILQ_REMOVE(&fdp->fd_kqlist, kq, kq_list); 2244 if (filedesc_unlock) 2245 FILEDESC_XUNLOCK(fdp); 2246 2247 kqueue_destroy(kq); 2248 chgkqcnt(kq->kq_cred->cr_ruidinfo, -1, 0); 2249 crfree(kq->kq_cred); 2250 free(kq, M_KQUEUE); 2251 fp->f_data = NULL; 2252 2253 return (0); 2254 } 2255 2256 static int 2257 kqueue_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 2258 { 2259 2260 kif->kf_type = KF_TYPE_KQUEUE; 2261 return (0); 2262 } 2263 2264 static void 2265 kqueue_wakeup(struct kqueue *kq) 2266 { 2267 KQ_OWNED(kq); 2268 2269 if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) { 2270 kq->kq_state &= ~KQ_SLEEP; 2271 wakeup(kq); 2272 } 2273 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2274 selwakeuppri(&kq->kq_sel, PSOCK); 2275 if (!SEL_WAITING(&kq->kq_sel)) 2276 kq->kq_state &= ~KQ_SEL; 2277 } 2278 if (!knlist_empty(&kq->kq_sel.si_note)) 2279 kqueue_schedtask(kq); 2280 if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) { 2281 pgsigio(&kq->kq_sigio, SIGIO, 0); 2282 } 2283 } 2284 2285 /* 2286 * Walk down a list of knotes, activating them if their event has triggered. 2287 * 2288 * There is a possibility to optimize in the case of one kq watching another. 2289 * Instead of scheduling a task to wake it up, you could pass enough state 2290 * down the chain to make up the parent kqueue. Make this code functional 2291 * first. 2292 */ 2293 void 2294 knote(struct knlist *list, long hint, int lockflags) 2295 { 2296 struct kqueue *kq; 2297 struct knote *kn, *tkn; 2298 int error; 2299 2300 if (list == NULL) 2301 return; 2302 2303 KNL_ASSERT_LOCK(list, lockflags & KNF_LISTLOCKED); 2304 2305 if ((lockflags & KNF_LISTLOCKED) == 0) 2306 list->kl_lock(list->kl_lockarg); 2307 2308 /* 2309 * If we unlock the list lock (and enter influx), we can 2310 * eliminate the kqueue scheduling, but this will introduce 2311 * four lock/unlock's for each knote to test. Also, marker 2312 * would be needed to keep iteration position, since filters 2313 * or other threads could remove events. 2314 */ 2315 SLIST_FOREACH_SAFE(kn, &list->kl_list, kn_selnext, tkn) { 2316 kq = kn->kn_kq; 2317 KQ_LOCK(kq); 2318 if (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0) { 2319 /* 2320 * Do not process the influx notes, except for 2321 * the influx coming from the kq unlock in the 2322 * kqueue_scan(). In the later case, we do 2323 * not interfere with the scan, since the code 2324 * fragment in kqueue_scan() locks the knlist, 2325 * and cannot proceed until we finished. 2326 */ 2327 KQ_UNLOCK(kq); 2328 } else if ((lockflags & KNF_NOKQLOCK) != 0) { 2329 kn_enter_flux(kn); 2330 KQ_UNLOCK(kq); 2331 error = kn->kn_fop->f_event(kn, hint); 2332 KQ_LOCK(kq); 2333 kn_leave_flux(kn); 2334 if (error) 2335 KNOTE_ACTIVATE(kn, 1); 2336 KQ_UNLOCK_FLUX(kq); 2337 } else { 2338 if (kn->kn_fop->f_event(kn, hint)) 2339 KNOTE_ACTIVATE(kn, 1); 2340 KQ_UNLOCK(kq); 2341 } 2342 } 2343 if ((lockflags & KNF_LISTLOCKED) == 0) 2344 list->kl_unlock(list->kl_lockarg); 2345 } 2346 2347 /* 2348 * add a knote to a knlist 2349 */ 2350 void 2351 knlist_add(struct knlist *knl, struct knote *kn, int islocked) 2352 { 2353 2354 KNL_ASSERT_LOCK(knl, islocked); 2355 KQ_NOTOWNED(kn->kn_kq); 2356 KASSERT(kn_in_flux(kn), ("knote %p not in flux", kn)); 2357 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2358 ("knote %p was not detached", kn)); 2359 if (!islocked) 2360 knl->kl_lock(knl->kl_lockarg); 2361 SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext); 2362 if (!islocked) 2363 knl->kl_unlock(knl->kl_lockarg); 2364 KQ_LOCK(kn->kn_kq); 2365 kn->kn_knlist = knl; 2366 kn->kn_status &= ~KN_DETACHED; 2367 KQ_UNLOCK(kn->kn_kq); 2368 } 2369 2370 static void 2371 knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked, 2372 int kqislocked) 2373 { 2374 2375 KASSERT(!kqislocked || knlislocked, ("kq locked w/o knl locked")); 2376 KNL_ASSERT_LOCK(knl, knlislocked); 2377 mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED); 2378 KASSERT(kqislocked || kn_in_flux(kn), ("knote %p not in flux", kn)); 2379 KASSERT((kn->kn_status & KN_DETACHED) == 0, 2380 ("knote %p was already detached", kn)); 2381 if (!knlislocked) 2382 knl->kl_lock(knl->kl_lockarg); 2383 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext); 2384 kn->kn_knlist = NULL; 2385 if (!knlislocked) 2386 kn_list_unlock(knl); 2387 if (!kqislocked) 2388 KQ_LOCK(kn->kn_kq); 2389 kn->kn_status |= KN_DETACHED; 2390 if (!kqislocked) 2391 KQ_UNLOCK(kn->kn_kq); 2392 } 2393 2394 /* 2395 * remove knote from the specified knlist 2396 */ 2397 void 2398 knlist_remove(struct knlist *knl, struct knote *kn, int islocked) 2399 { 2400 2401 knlist_remove_kq(knl, kn, islocked, 0); 2402 } 2403 2404 int 2405 knlist_empty(struct knlist *knl) 2406 { 2407 2408 KNL_ASSERT_LOCKED(knl); 2409 return (SLIST_EMPTY(&knl->kl_list)); 2410 } 2411 2412 static struct mtx knlist_lock; 2413 MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects", 2414 MTX_DEF); 2415 static void knlist_mtx_lock(void *arg); 2416 static void knlist_mtx_unlock(void *arg); 2417 2418 static void 2419 knlist_mtx_lock(void *arg) 2420 { 2421 2422 mtx_lock((struct mtx *)arg); 2423 } 2424 2425 static void 2426 knlist_mtx_unlock(void *arg) 2427 { 2428 2429 mtx_unlock((struct mtx *)arg); 2430 } 2431 2432 static void 2433 knlist_mtx_assert_lock(void *arg, int what) 2434 { 2435 2436 if (what == LA_LOCKED) 2437 mtx_assert((struct mtx *)arg, MA_OWNED); 2438 else 2439 mtx_assert((struct mtx *)arg, MA_NOTOWNED); 2440 } 2441 2442 static void 2443 knlist_rw_rlock(void *arg) 2444 { 2445 2446 rw_rlock((struct rwlock *)arg); 2447 } 2448 2449 static void 2450 knlist_rw_runlock(void *arg) 2451 { 2452 2453 rw_runlock((struct rwlock *)arg); 2454 } 2455 2456 static void 2457 knlist_rw_assert_lock(void *arg, int what) 2458 { 2459 2460 if (what == LA_LOCKED) 2461 rw_assert((struct rwlock *)arg, RA_LOCKED); 2462 else 2463 rw_assert((struct rwlock *)arg, RA_UNLOCKED); 2464 } 2465 2466 void 2467 knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *), 2468 void (*kl_unlock)(void *), 2469 void (*kl_assert_lock)(void *, int)) 2470 { 2471 2472 if (lock == NULL) 2473 knl->kl_lockarg = &knlist_lock; 2474 else 2475 knl->kl_lockarg = lock; 2476 2477 if (kl_lock == NULL) 2478 knl->kl_lock = knlist_mtx_lock; 2479 else 2480 knl->kl_lock = kl_lock; 2481 if (kl_unlock == NULL) 2482 knl->kl_unlock = knlist_mtx_unlock; 2483 else 2484 knl->kl_unlock = kl_unlock; 2485 if (kl_assert_lock == NULL) 2486 knl->kl_assert_lock = knlist_mtx_assert_lock; 2487 else 2488 knl->kl_assert_lock = kl_assert_lock; 2489 2490 knl->kl_autodestroy = 0; 2491 SLIST_INIT(&knl->kl_list); 2492 } 2493 2494 void 2495 knlist_init_mtx(struct knlist *knl, struct mtx *lock) 2496 { 2497 2498 knlist_init(knl, lock, NULL, NULL, NULL); 2499 } 2500 2501 struct knlist * 2502 knlist_alloc(struct mtx *lock) 2503 { 2504 struct knlist *knl; 2505 2506 knl = malloc(sizeof(struct knlist), M_KQUEUE, M_WAITOK); 2507 knlist_init_mtx(knl, lock); 2508 return (knl); 2509 } 2510 2511 void 2512 knlist_init_rw_reader(struct knlist *knl, struct rwlock *lock) 2513 { 2514 2515 knlist_init(knl, lock, knlist_rw_rlock, knlist_rw_runlock, 2516 knlist_rw_assert_lock); 2517 } 2518 2519 void 2520 knlist_destroy(struct knlist *knl) 2521 { 2522 2523 KASSERT(KNLIST_EMPTY(knl), 2524 ("destroying knlist %p with knotes on it", knl)); 2525 } 2526 2527 void 2528 knlist_detach(struct knlist *knl) 2529 { 2530 2531 KNL_ASSERT_LOCKED(knl); 2532 knl->kl_autodestroy = 1; 2533 if (knlist_empty(knl)) { 2534 knlist_destroy(knl); 2535 free(knl, M_KQUEUE); 2536 } 2537 } 2538 2539 /* 2540 * Even if we are locked, we may need to drop the lock to allow any influx 2541 * knotes time to "settle". 2542 */ 2543 void 2544 knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn) 2545 { 2546 struct knote *kn, *kn2; 2547 struct kqueue *kq; 2548 2549 KASSERT(!knl->kl_autodestroy, ("cleardel for autodestroy %p", knl)); 2550 if (islocked) 2551 KNL_ASSERT_LOCKED(knl); 2552 else { 2553 KNL_ASSERT_UNLOCKED(knl); 2554 again: /* need to reacquire lock since we have dropped it */ 2555 knl->kl_lock(knl->kl_lockarg); 2556 } 2557 2558 SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) { 2559 kq = kn->kn_kq; 2560 KQ_LOCK(kq); 2561 if (kn_in_flux(kn)) { 2562 KQ_UNLOCK(kq); 2563 continue; 2564 } 2565 knlist_remove_kq(knl, kn, 1, 1); 2566 if (killkn) { 2567 kn_enter_flux(kn); 2568 KQ_UNLOCK(kq); 2569 knote_drop_detached(kn, td); 2570 } else { 2571 /* Make sure cleared knotes disappear soon */ 2572 kn->kn_flags |= EV_EOF | EV_ONESHOT; 2573 KQ_UNLOCK(kq); 2574 } 2575 kq = NULL; 2576 } 2577 2578 if (!SLIST_EMPTY(&knl->kl_list)) { 2579 /* there are still in flux knotes remaining */ 2580 kn = SLIST_FIRST(&knl->kl_list); 2581 kq = kn->kn_kq; 2582 KQ_LOCK(kq); 2583 KASSERT(kn_in_flux(kn), ("knote removed w/o list lock")); 2584 knl->kl_unlock(knl->kl_lockarg); 2585 kq->kq_state |= KQ_FLUXWAIT; 2586 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0); 2587 kq = NULL; 2588 goto again; 2589 } 2590 2591 if (islocked) 2592 KNL_ASSERT_LOCKED(knl); 2593 else { 2594 knl->kl_unlock(knl->kl_lockarg); 2595 KNL_ASSERT_UNLOCKED(knl); 2596 } 2597 } 2598 2599 /* 2600 * Remove all knotes referencing a specified fd must be called with FILEDESC 2601 * lock. This prevents a race where a new fd comes along and occupies the 2602 * entry and we attach a knote to the fd. 2603 */ 2604 void 2605 knote_fdclose(struct thread *td, int fd) 2606 { 2607 struct filedesc *fdp = td->td_proc->p_fd; 2608 struct kqueue *kq; 2609 struct knote *kn; 2610 int influx; 2611 2612 FILEDESC_XLOCK_ASSERT(fdp); 2613 2614 /* 2615 * We shouldn't have to worry about new kevents appearing on fd 2616 * since filedesc is locked. 2617 */ 2618 TAILQ_FOREACH(kq, &fdp->fd_kqlist, kq_list) { 2619 KQ_LOCK(kq); 2620 2621 again: 2622 influx = 0; 2623 while (kq->kq_knlistsize > fd && 2624 (kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) { 2625 if (kn_in_flux(kn)) { 2626 /* someone else might be waiting on our knote */ 2627 if (influx) 2628 wakeup(kq); 2629 kq->kq_state |= KQ_FLUXWAIT; 2630 msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0); 2631 goto again; 2632 } 2633 kn_enter_flux(kn); 2634 KQ_UNLOCK(kq); 2635 influx = 1; 2636 knote_drop(kn, td); 2637 KQ_LOCK(kq); 2638 } 2639 KQ_UNLOCK_FLUX(kq); 2640 } 2641 } 2642 2643 static int 2644 knote_attach(struct knote *kn, struct kqueue *kq) 2645 { 2646 struct klist *list; 2647 2648 KASSERT(kn_in_flux(kn), ("knote %p not marked influx", kn)); 2649 KQ_OWNED(kq); 2650 2651 if ((kq->kq_state & KQ_CLOSING) != 0) 2652 return (EBADF); 2653 if (kn->kn_fop->f_isfd) { 2654 if (kn->kn_id >= kq->kq_knlistsize) 2655 return (ENOMEM); 2656 list = &kq->kq_knlist[kn->kn_id]; 2657 } else { 2658 if (kq->kq_knhash == NULL) 2659 return (ENOMEM); 2660 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2661 } 2662 SLIST_INSERT_HEAD(list, kn, kn_link); 2663 return (0); 2664 } 2665 2666 static void 2667 knote_drop(struct knote *kn, struct thread *td) 2668 { 2669 2670 if ((kn->kn_status & KN_DETACHED) == 0) 2671 kn->kn_fop->f_detach(kn); 2672 knote_drop_detached(kn, td); 2673 } 2674 2675 static void 2676 knote_drop_detached(struct knote *kn, struct thread *td) 2677 { 2678 struct kqueue *kq; 2679 struct klist *list; 2680 2681 kq = kn->kn_kq; 2682 2683 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2684 ("knote %p still attached", kn)); 2685 KQ_NOTOWNED(kq); 2686 2687 KQ_LOCK(kq); 2688 KASSERT(kn->kn_influx == 1, 2689 ("knote_drop called on %p with influx %d", kn, kn->kn_influx)); 2690 2691 if (kn->kn_fop->f_isfd) 2692 list = &kq->kq_knlist[kn->kn_id]; 2693 else 2694 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2695 2696 if (!SLIST_EMPTY(list)) 2697 SLIST_REMOVE(list, kn, knote, kn_link); 2698 if (kn->kn_status & KN_QUEUED) 2699 knote_dequeue(kn); 2700 KQ_UNLOCK_FLUX(kq); 2701 2702 if (kn->kn_fop->f_isfd) { 2703 fdrop(kn->kn_fp, td); 2704 kn->kn_fp = NULL; 2705 } 2706 kqueue_fo_release(kn->kn_kevent.filter); 2707 kn->kn_fop = NULL; 2708 knote_free(kn); 2709 } 2710 2711 static void 2712 knote_enqueue(struct knote *kn) 2713 { 2714 struct kqueue *kq = kn->kn_kq; 2715 2716 KQ_OWNED(kn->kn_kq); 2717 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 2718 2719 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2720 kn->kn_status |= KN_QUEUED; 2721 kq->kq_count++; 2722 kqueue_wakeup(kq); 2723 } 2724 2725 static void 2726 knote_dequeue(struct knote *kn) 2727 { 2728 struct kqueue *kq = kn->kn_kq; 2729 2730 KQ_OWNED(kn->kn_kq); 2731 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 2732 2733 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 2734 kn->kn_status &= ~KN_QUEUED; 2735 kq->kq_count--; 2736 } 2737 2738 static void 2739 knote_init(void) 2740 { 2741 2742 knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL, 2743 NULL, NULL, UMA_ALIGN_PTR, 0); 2744 } 2745 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL); 2746 2747 static struct knote * 2748 knote_alloc(int mflag) 2749 { 2750 2751 return (uma_zalloc(knote_zone, mflag | M_ZERO)); 2752 } 2753 2754 static void 2755 knote_free(struct knote *kn) 2756 { 2757 2758 uma_zfree(knote_zone, kn); 2759 } 2760 2761 /* 2762 * Register the kev w/ the kq specified by fd. 2763 */ 2764 int 2765 kqfd_register(int fd, struct kevent *kev, struct thread *td, int mflag) 2766 { 2767 struct kqueue *kq; 2768 struct file *fp; 2769 cap_rights_t rights; 2770 int error; 2771 2772 error = fget(td, fd, cap_rights_init_one(&rights, CAP_KQUEUE_CHANGE), 2773 &fp); 2774 if (error != 0) 2775 return (error); 2776 if ((error = kqueue_acquire(fp, &kq)) != 0) 2777 goto noacquire; 2778 2779 error = kqueue_register(kq, kev, td, mflag); 2780 kqueue_release(kq, 0); 2781 2782 noacquire: 2783 fdrop(fp, td); 2784 return (error); 2785 } 2786