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 * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org> 3 * Copyright 2004 John-Mark Gurney <jmg@FreeBSD.org> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD: releng/8.0/sys/kern/kern_event.c 195148 2009-06-28 21:49:43Z stas $"); 30 31 #include "opt_ktrace.h" 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/kernel.h> 36 #include <sys/lock.h> 37 #include <sys/mutex.h> 38 #include <sys/proc.h> 39 #include <sys/malloc.h> 40 #include <sys/unistd.h> 41 #include <sys/file.h> 42 #include <sys/filedesc.h> 43 #include <sys/filio.h> 44 #include <sys/fcntl.h> 45 #include <sys/kthread.h> 46 #include <sys/selinfo.h> 47 #include <sys/queue.h> 48 #include <sys/event.h> 49 #include <sys/eventvar.h> 50 #include <sys/poll.h> 51 #include <sys/protosw.h> 52 #include <sys/sigio.h> 53 #include <sys/signalvar.h> 54 #include <sys/socket.h> 55 #include <sys/socketvar.h> 56 #include <sys/stat.h> 57 #include <sys/sysctl.h> 58 #include <sys/sysproto.h> 59 #include <sys/syscallsubr.h> 60 #include <sys/taskqueue.h> 61 #include <sys/uio.h> 62 #ifdef KTRACE 63 #include <sys/ktrace.h> 64 #endif 65 66 #include <vm/uma.h> 67 68 static MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system"); 69 70 /* 71 * This lock is used if multiple kq locks are required. This possibly 72 * should be made into a per proc lock. 73 */ 74 static struct mtx kq_global; 75 MTX_SYSINIT(kq_global, &kq_global, "kqueue order", MTX_DEF); 76 #define KQ_GLOBAL_LOCK(lck, haslck) do { \ 77 if (!haslck) \ 78 mtx_lock(lck); \ 79 haslck = 1; \ 80 } while (0) 81 #define KQ_GLOBAL_UNLOCK(lck, haslck) do { \ 82 if (haslck) \ 83 mtx_unlock(lck); \ 84 haslck = 0; \ 85 } while (0) 86 87 TASKQUEUE_DEFINE_THREAD(kqueue); 88 89 static int kevent_copyout(void *arg, struct kevent *kevp, int count); 90 static int kevent_copyin(void *arg, struct kevent *kevp, int count); 91 static int kqueue_register(struct kqueue *kq, struct kevent *kev, 92 struct thread *td, int waitok); 93 static int kqueue_acquire(struct file *fp, struct kqueue **kqp); 94 static void kqueue_release(struct kqueue *kq, int locked); 95 static int kqueue_expand(struct kqueue *kq, struct filterops *fops, 96 uintptr_t ident, int waitok); 97 static void kqueue_task(void *arg, int pending); 98 static int kqueue_scan(struct kqueue *kq, int maxevents, 99 struct kevent_copyops *k_ops, 100 const struct timespec *timeout, 101 struct kevent *keva, struct thread *td); 102 static void kqueue_wakeup(struct kqueue *kq); 103 static struct filterops *kqueue_fo_find(int filt); 104 static void kqueue_fo_release(int filt); 105 106 static fo_rdwr_t kqueue_read; 107 static fo_rdwr_t kqueue_write; 108 static fo_truncate_t kqueue_truncate; 109 static fo_ioctl_t kqueue_ioctl; 110 static fo_poll_t kqueue_poll; 111 static fo_kqfilter_t kqueue_kqfilter; 112 static fo_stat_t kqueue_stat; 113 static fo_close_t kqueue_close; 114 115 static struct fileops kqueueops = { 116 .fo_read = kqueue_read, 117 .fo_write = kqueue_write, 118 .fo_truncate = kqueue_truncate, 119 .fo_ioctl = kqueue_ioctl, 120 .fo_poll = kqueue_poll, 121 .fo_kqfilter = kqueue_kqfilter, 122 .fo_stat = kqueue_stat, 123 .fo_close = kqueue_close, 124 }; 125 126 static int knote_attach(struct knote *kn, struct kqueue *kq); 127 static void knote_drop(struct knote *kn, struct thread *td); 128 static void knote_enqueue(struct knote *kn); 129 static void knote_dequeue(struct knote *kn); 130 static void knote_init(void); 131 static struct knote *knote_alloc(int waitok); 132 static void knote_free(struct knote *kn); 133 134 static void filt_kqdetach(struct knote *kn); 135 static int filt_kqueue(struct knote *kn, long hint); 136 static int filt_procattach(struct knote *kn); 137 static void filt_procdetach(struct knote *kn); 138 static int filt_proc(struct knote *kn, long hint); 139 static int filt_fileattach(struct knote *kn); 140 static void filt_timerexpire(void *knx); 141 static int filt_timerattach(struct knote *kn); 142 static void filt_timerdetach(struct knote *kn); 143 static int filt_timer(struct knote *kn, long hint); 144 145 static struct filterops file_filtops = 146 { 1, filt_fileattach, NULL, NULL }; 147 static struct filterops kqread_filtops = 148 { 1, NULL, filt_kqdetach, filt_kqueue }; 149 /* XXX - move to kern_proc.c? */ 150 static struct filterops proc_filtops = 151 { 0, filt_procattach, filt_procdetach, filt_proc }; 152 static struct filterops timer_filtops = 153 { 0, filt_timerattach, filt_timerdetach, filt_timer }; 154 155 static uma_zone_t knote_zone; 156 static int kq_ncallouts = 0; 157 static int kq_calloutmax = (4 * 1024); 158 SYSCTL_INT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW, 159 &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue"); 160 161 /* XXX - ensure not KN_INFLUX?? */ 162 #define KNOTE_ACTIVATE(kn, islock) do { \ 163 if ((islock)) \ 164 mtx_assert(&(kn)->kn_kq->kq_lock, MA_OWNED); \ 165 else \ 166 KQ_LOCK((kn)->kn_kq); \ 167 (kn)->kn_status |= KN_ACTIVE; \ 168 if (((kn)->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 169 knote_enqueue((kn)); \ 170 if (!(islock)) \ 171 KQ_UNLOCK((kn)->kn_kq); \ 172 } while(0) 173 #define KQ_LOCK(kq) do { \ 174 mtx_lock(&(kq)->kq_lock); \ 175 } while (0) 176 #define KQ_FLUX_WAKEUP(kq) do { \ 177 if (((kq)->kq_state & KQ_FLUXWAIT) == KQ_FLUXWAIT) { \ 178 (kq)->kq_state &= ~KQ_FLUXWAIT; \ 179 wakeup((kq)); \ 180 } \ 181 } while (0) 182 #define KQ_UNLOCK_FLUX(kq) do { \ 183 KQ_FLUX_WAKEUP(kq); \ 184 mtx_unlock(&(kq)->kq_lock); \ 185 } while (0) 186 #define KQ_UNLOCK(kq) do { \ 187 mtx_unlock(&(kq)->kq_lock); \ 188 } while (0) 189 #define KQ_OWNED(kq) do { \ 190 mtx_assert(&(kq)->kq_lock, MA_OWNED); \ 191 } while (0) 192 #define KQ_NOTOWNED(kq) do { \ 193 mtx_assert(&(kq)->kq_lock, MA_NOTOWNED); \ 194 } while (0) 195 #define KN_LIST_LOCK(kn) do { \ 196 if (kn->kn_knlist != NULL) \ 197 kn->kn_knlist->kl_lock(kn->kn_knlist->kl_lockarg); \ 198 } while (0) 199 #define KN_LIST_UNLOCK(kn) do { \ 200 if (kn->kn_knlist != NULL) \ 201 kn->kn_knlist->kl_unlock(kn->kn_knlist->kl_lockarg); \ 202 } while (0) 203 #define KNL_ASSERT_LOCK(knl, islocked) do { \ 204 if (islocked) \ 205 KNL_ASSERT_LOCKED(knl); \ 206 else \ 207 KNL_ASSERT_UNLOCKED(knl); \ 208 } while (0) 209 #ifdef INVARIANTS 210 #define KNL_ASSERT_LOCKED(knl) do { \ 211 knl->kl_assert_locked((knl)->kl_lockarg); \ 212 } while (0) 213 #define KNL_ASSERT_UNLOCKED(knl) do { \ 214 knl->kl_assert_unlocked((knl)->kl_lockarg); \ 215 } while (0) 216 #else /* !INVARIANTS */ 217 #define KNL_ASSERT_LOCKED(knl) do {} while(0) 218 #define KNL_ASSERT_UNLOCKED(knl) do {} while (0) 219 #endif /* INVARIANTS */ 220 221 #define KN_HASHSIZE 64 /* XXX should be tunable */ 222 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 223 224 static int 225 filt_nullattach(struct knote *kn) 226 { 227 228 return (ENXIO); 229 }; 230 231 struct filterops null_filtops = 232 { 0, filt_nullattach, NULL, NULL }; 233 234 /* XXX - make SYSINIT to add these, and move into respective modules. */ 235 extern struct filterops sig_filtops; 236 extern struct filterops fs_filtops; 237 238 /* 239 * Table for for all system-defined filters. 240 */ 241 static struct mtx filterops_lock; 242 MTX_SYSINIT(kqueue_filterops, &filterops_lock, "protect sysfilt_ops", 243 MTX_DEF); 244 static struct { 245 struct filterops *for_fop; 246 int for_refcnt; 247 } sysfilt_ops[EVFILT_SYSCOUNT] = { 248 { &file_filtops }, /* EVFILT_READ */ 249 { &file_filtops }, /* EVFILT_WRITE */ 250 { &null_filtops }, /* EVFILT_AIO */ 251 { &file_filtops }, /* EVFILT_VNODE */ 252 { &proc_filtops }, /* EVFILT_PROC */ 253 { &sig_filtops }, /* EVFILT_SIGNAL */ 254 { &timer_filtops }, /* EVFILT_TIMER */ 255 { &file_filtops }, /* EVFILT_NETDEV */ 256 { &fs_filtops }, /* EVFILT_FS */ 257 { &null_filtops }, /* EVFILT_LIO */ 258 }; 259 260 /* 261 * Simple redirection for all cdevsw style objects to call their fo_kqfilter 262 * method. 263 */ 264 static int 265 filt_fileattach(struct knote *kn) 266 { 267 268 return (fo_kqfilter(kn->kn_fp, kn)); 269 } 270 271 /*ARGSUSED*/ 272 static int 273 kqueue_kqfilter(struct file *fp, struct knote *kn) 274 { 275 struct kqueue *kq = kn->kn_fp->f_data; 276 277 if (kn->kn_filter != EVFILT_READ) 278 return (EINVAL); 279 280 kn->kn_status |= KN_KQUEUE; 281 kn->kn_fop = &kqread_filtops; 282 knlist_add(&kq->kq_sel.si_note, kn, 0); 283 284 return (0); 285 } 286 287 static void 288 filt_kqdetach(struct knote *kn) 289 { 290 struct kqueue *kq = kn->kn_fp->f_data; 291 292 knlist_remove(&kq->kq_sel.si_note, kn, 0); 293 } 294 295 /*ARGSUSED*/ 296 static int 297 filt_kqueue(struct knote *kn, long hint) 298 { 299 struct kqueue *kq = kn->kn_fp->f_data; 300 301 kn->kn_data = kq->kq_count; 302 return (kn->kn_data > 0); 303 } 304 305 /* XXX - move to kern_proc.c? */ 306 static int 307 filt_procattach(struct knote *kn) 308 { 309 struct proc *p; 310 int immediate; 311 int error; 312 313 immediate = 0; 314 p = pfind(kn->kn_id); 315 if (p == NULL && (kn->kn_sfflags & NOTE_EXIT)) { 316 p = zpfind(kn->kn_id); 317 immediate = 1; 318 } else if (p != NULL && (p->p_flag & P_WEXIT)) { 319 immediate = 1; 320 } 321 322 if (p == NULL) 323 return (ESRCH); 324 if ((error = p_cansee(curthread, p))) 325 return (error); 326 327 kn->kn_ptr.p_proc = p; 328 kn->kn_flags |= EV_CLEAR; /* automatically set */ 329 330 /* 331 * internal flag indicating registration done by kernel 332 */ 333 if (kn->kn_flags & EV_FLAG1) { 334 kn->kn_data = kn->kn_sdata; /* ppid */ 335 kn->kn_fflags = NOTE_CHILD; 336 kn->kn_flags &= ~EV_FLAG1; 337 } 338 339 if (immediate == 0) 340 knlist_add(&p->p_klist, kn, 1); 341 342 /* 343 * Immediately activate any exit notes if the target process is a 344 * zombie. This is necessary to handle the case where the target 345 * process, e.g. a child, dies before the kevent is registered. 346 */ 347 if (immediate && filt_proc(kn, NOTE_EXIT)) 348 KNOTE_ACTIVATE(kn, 0); 349 350 PROC_UNLOCK(p); 351 352 return (0); 353 } 354 355 /* 356 * The knote may be attached to a different process, which may exit, 357 * leaving nothing for the knote to be attached to. So when the process 358 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 359 * it will be deleted when read out. However, as part of the knote deletion, 360 * this routine is called, so a check is needed to avoid actually performing 361 * a detach, because the original process does not exist any more. 362 */ 363 /* XXX - move to kern_proc.c? */ 364 static void 365 filt_procdetach(struct knote *kn) 366 { 367 struct proc *p; 368 369 p = kn->kn_ptr.p_proc; 370 knlist_remove(&p->p_klist, kn, 0); 371 kn->kn_ptr.p_proc = NULL; 372 } 373 374 /* XXX - move to kern_proc.c? */ 375 static int 376 filt_proc(struct knote *kn, long hint) 377 { 378 struct proc *p = kn->kn_ptr.p_proc; 379 u_int event; 380 381 /* 382 * mask off extra data 383 */ 384 event = (u_int)hint & NOTE_PCTRLMASK; 385 386 /* 387 * if the user is interested in this event, record it. 388 */ 389 if (kn->kn_sfflags & event) 390 kn->kn_fflags |= event; 391 392 /* 393 * process is gone, so flag the event as finished. 394 */ 395 if (event == NOTE_EXIT) { 396 if (!(kn->kn_status & KN_DETACHED)) 397 knlist_remove_inevent(&p->p_klist, kn); 398 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 399 kn->kn_data = p->p_xstat; 400 kn->kn_ptr.p_proc = NULL; 401 return (1); 402 } 403 404 return (kn->kn_fflags != 0); 405 } 406 407 /* 408 * Called when the process forked. It mostly does the same as the 409 * knote(), activating all knotes registered to be activated when the 410 * process forked. Additionally, for each knote attached to the 411 * parent, check whether user wants to track the new process. If so 412 * attach a new knote to it, and immediately report an event with the 413 * child's pid. 414 */ 415 void 416 knote_fork(struct knlist *list, int pid) 417 { 418 struct kqueue *kq; 419 struct knote *kn; 420 struct kevent kev; 421 int error; 422 423 if (list == NULL) 424 return; 425 list->kl_lock(list->kl_lockarg); 426 427 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { 428 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) 429 continue; 430 kq = kn->kn_kq; 431 KQ_LOCK(kq); 432 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 433 KQ_UNLOCK(kq); 434 continue; 435 } 436 437 /* 438 * The same as knote(), activate the event. 439 */ 440 if ((kn->kn_sfflags & NOTE_TRACK) == 0) { 441 kn->kn_status |= KN_HASKQLOCK; 442 if (kn->kn_fop->f_event(kn, NOTE_FORK | pid)) 443 KNOTE_ACTIVATE(kn, 1); 444 kn->kn_status &= ~KN_HASKQLOCK; 445 KQ_UNLOCK(kq); 446 continue; 447 } 448 449 /* 450 * The NOTE_TRACK case. In addition to the activation 451 * of the event, we need to register new event to 452 * track the child. Drop the locks in preparation for 453 * the call to kqueue_register(). 454 */ 455 kn->kn_status |= KN_INFLUX; 456 KQ_UNLOCK(kq); 457 list->kl_unlock(list->kl_lockarg); 458 459 /* 460 * Activate existing knote and register a knote with 461 * new process. 462 */ 463 kev.ident = pid; 464 kev.filter = kn->kn_filter; 465 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 466 kev.fflags = kn->kn_sfflags; 467 kev.data = kn->kn_id; /* parent */ 468 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 469 error = kqueue_register(kq, &kev, NULL, 0); 470 if (kn->kn_fop->f_event(kn, NOTE_FORK | pid)) 471 KNOTE_ACTIVATE(kn, 0); 472 if (error) 473 kn->kn_fflags |= NOTE_TRACKERR; 474 KQ_LOCK(kq); 475 kn->kn_status &= ~KN_INFLUX; 476 KQ_UNLOCK_FLUX(kq); 477 list->kl_lock(list->kl_lockarg); 478 } 479 list->kl_unlock(list->kl_lockarg); 480 } 481 482 static int 483 timertoticks(intptr_t data) 484 { 485 struct timeval tv; 486 int tticks; 487 488 tv.tv_sec = data / 1000; 489 tv.tv_usec = (data % 1000) * 1000; 490 tticks = tvtohz(&tv); 491 492 return tticks; 493 } 494 495 /* XXX - move to kern_timeout.c? */ 496 static void 497 filt_timerexpire(void *knx) 498 { 499 struct knote *kn = knx; 500 struct callout *calloutp; 501 502 kn->kn_data++; 503 KNOTE_ACTIVATE(kn, 0); /* XXX - handle locking */ 504 505 if ((kn->kn_flags & EV_ONESHOT) != EV_ONESHOT) { 506 calloutp = (struct callout *)kn->kn_hook; 507 callout_reset_curcpu(calloutp, timertoticks(kn->kn_sdata), 508 filt_timerexpire, kn); 509 } 510 } 511 512 /* 513 * data contains amount of time to sleep, in milliseconds 514 */ 515 /* XXX - move to kern_timeout.c? */ 516 static int 517 filt_timerattach(struct knote *kn) 518 { 519 struct callout *calloutp; 520 521 atomic_add_int(&kq_ncallouts, 1); 522 523 if (kq_ncallouts >= kq_calloutmax) { 524 atomic_add_int(&kq_ncallouts, -1); 525 return (ENOMEM); 526 } 527 528 kn->kn_flags |= EV_CLEAR; /* automatically set */ 529 kn->kn_status &= ~KN_DETACHED; /* knlist_add usually sets it */ 530 calloutp = malloc(sizeof(*calloutp), M_KQUEUE, M_WAITOK); 531 callout_init(calloutp, CALLOUT_MPSAFE); 532 kn->kn_hook = calloutp; 533 callout_reset_curcpu(calloutp, timertoticks(kn->kn_sdata), 534 filt_timerexpire, kn); 535 536 return (0); 537 } 538 539 /* XXX - move to kern_timeout.c? */ 540 static void 541 filt_timerdetach(struct knote *kn) 542 { 543 struct callout *calloutp; 544 545 calloutp = (struct callout *)kn->kn_hook; 546 callout_drain(calloutp); 547 free(calloutp, M_KQUEUE); 548 atomic_add_int(&kq_ncallouts, -1); 549 kn->kn_status |= KN_DETACHED; /* knlist_remove usually clears it */ 550 } 551 552 /* XXX - move to kern_timeout.c? */ 553 static int 554 filt_timer(struct knote *kn, long hint) 555 { 556 557 return (kn->kn_data != 0); 558 } 559 560 int 561 kqueue(struct thread *td, struct kqueue_args *uap) 562 { 563 struct filedesc *fdp; 564 struct kqueue *kq; 565 struct file *fp; 566 int fd, error; 567 568 fdp = td->td_proc->p_fd; 569 error = falloc(td, &fp, &fd); 570 if (error) 571 goto done2; 572 573 /* An extra reference on `nfp' has been held for us by falloc(). */ 574 kq = malloc(sizeof *kq, M_KQUEUE, M_WAITOK | M_ZERO); 575 mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF|MTX_DUPOK); 576 TAILQ_INIT(&kq->kq_head); 577 kq->kq_fdp = fdp; 578 knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock); 579 TASK_INIT(&kq->kq_task, 0, kqueue_task, kq); 580 581 FILEDESC_XLOCK(fdp); 582 SLIST_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list); 583 FILEDESC_XUNLOCK(fdp); 584 585 finit(fp, FREAD | FWRITE, DTYPE_KQUEUE, kq, &kqueueops); 586 fdrop(fp, td); 587 588 td->td_retval[0] = fd; 589 done2: 590 return (error); 591 } 592 593 #ifndef _SYS_SYSPROTO_H_ 594 struct kevent_args { 595 int fd; 596 const struct kevent *changelist; 597 int nchanges; 598 struct kevent *eventlist; 599 int nevents; 600 const struct timespec *timeout; 601 }; 602 #endif 603 int 604 kevent(struct thread *td, struct kevent_args *uap) 605 { 606 struct timespec ts, *tsp; 607 struct kevent_copyops k_ops = { uap, 608 kevent_copyout, 609 kevent_copyin}; 610 int error; 611 #ifdef KTRACE 612 struct uio ktruio; 613 struct iovec ktriov; 614 struct uio *ktruioin = NULL; 615 struct uio *ktruioout = NULL; 616 #endif 617 618 if (uap->timeout != NULL) { 619 error = copyin(uap->timeout, &ts, sizeof(ts)); 620 if (error) 621 return (error); 622 tsp = &ts; 623 } else 624 tsp = NULL; 625 626 #ifdef KTRACE 627 if (KTRPOINT(td, KTR_GENIO)) { 628 ktriov.iov_base = uap->changelist; 629 ktriov.iov_len = uap->nchanges * sizeof(struct kevent); 630 ktruio = (struct uio){ .uio_iov = &ktriov, .uio_iovcnt = 1, 631 .uio_segflg = UIO_USERSPACE, .uio_rw = UIO_READ, 632 .uio_td = td }; 633 ktruioin = cloneuio(&ktruio); 634 ktriov.iov_base = uap->eventlist; 635 ktriov.iov_len = uap->nevents * sizeof(struct kevent); 636 ktruioout = cloneuio(&ktruio); 637 } 638 #endif 639 640 error = kern_kevent(td, uap->fd, uap->nchanges, uap->nevents, 641 &k_ops, tsp); 642 643 #ifdef KTRACE 644 if (ktruioin != NULL) { 645 ktruioin->uio_resid = uap->nchanges * sizeof(struct kevent); 646 ktrgenio(uap->fd, UIO_WRITE, ktruioin, 0); 647 ktruioout->uio_resid = td->td_retval[0] * sizeof(struct kevent); 648 ktrgenio(uap->fd, UIO_READ, ktruioout, error); 649 } 650 #endif 651 652 return (error); 653 } 654 655 /* 656 * Copy 'count' items into the destination list pointed to by uap->eventlist. 657 */ 658 static int 659 kevent_copyout(void *arg, struct kevent *kevp, int count) 660 { 661 struct kevent_args *uap; 662 int error; 663 664 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 665 uap = (struct kevent_args *)arg; 666 667 error = copyout(kevp, uap->eventlist, count * sizeof *kevp); 668 if (error == 0) 669 uap->eventlist += count; 670 return (error); 671 } 672 673 /* 674 * Copy 'count' items from the list pointed to by uap->changelist. 675 */ 676 static int 677 kevent_copyin(void *arg, struct kevent *kevp, int count) 678 { 679 struct kevent_args *uap; 680 int error; 681 682 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 683 uap = (struct kevent_args *)arg; 684 685 error = copyin(uap->changelist, kevp, count * sizeof *kevp); 686 if (error == 0) 687 uap->changelist += count; 688 return (error); 689 } 690 691 int 692 kern_kevent(struct thread *td, int fd, int nchanges, int nevents, 693 struct kevent_copyops *k_ops, const struct timespec *timeout) 694 { 695 struct kevent keva[KQ_NEVENTS]; 696 struct kevent *kevp, *changes; 697 struct kqueue *kq; 698 struct file *fp; 699 int i, n, nerrors, error; 700 701 if ((error = fget(td, fd, &fp)) != 0) 702 return (error); 703 if ((error = kqueue_acquire(fp, &kq)) != 0) 704 goto done_norel; 705 706 nerrors = 0; 707 708 while (nchanges > 0) { 709 n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges; 710 error = k_ops->k_copyin(k_ops->arg, keva, n); 711 if (error) 712 goto done; 713 changes = keva; 714 for (i = 0; i < n; i++) { 715 kevp = &changes[i]; 716 if (!kevp->filter) 717 continue; 718 kevp->flags &= ~EV_SYSFLAGS; 719 error = kqueue_register(kq, kevp, td, 1); 720 if (error) { 721 if (nevents != 0) { 722 kevp->flags = EV_ERROR; 723 kevp->data = error; 724 (void) k_ops->k_copyout(k_ops->arg, 725 kevp, 1); 726 nevents--; 727 nerrors++; 728 } else { 729 goto done; 730 } 731 } 732 } 733 nchanges -= n; 734 } 735 if (nerrors) { 736 td->td_retval[0] = nerrors; 737 error = 0; 738 goto done; 739 } 740 741 error = kqueue_scan(kq, nevents, k_ops, timeout, keva, td); 742 done: 743 kqueue_release(kq, 0); 744 done_norel: 745 fdrop(fp, td); 746 return (error); 747 } 748 749 int 750 kqueue_add_filteropts(int filt, struct filterops *filtops) 751 { 752 int error; 753 754 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) { 755 printf( 756 "trying to add a filterop that is out of range: %d is beyond %d\n", 757 ~filt, EVFILT_SYSCOUNT); 758 return EINVAL; 759 } 760 mtx_lock(&filterops_lock); 761 if (sysfilt_ops[~filt].for_fop != &null_filtops && 762 sysfilt_ops[~filt].for_fop != NULL) 763 error = EEXIST; 764 else { 765 sysfilt_ops[~filt].for_fop = filtops; 766 sysfilt_ops[~filt].for_refcnt = 0; 767 } 768 mtx_unlock(&filterops_lock); 769 770 return (0); 771 } 772 773 int 774 kqueue_del_filteropts(int filt) 775 { 776 int error; 777 778 error = 0; 779 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 780 return EINVAL; 781 782 mtx_lock(&filterops_lock); 783 if (sysfilt_ops[~filt].for_fop == &null_filtops || 784 sysfilt_ops[~filt].for_fop == NULL) 785 error = EINVAL; 786 else if (sysfilt_ops[~filt].for_refcnt != 0) 787 error = EBUSY; 788 else { 789 sysfilt_ops[~filt].for_fop = &null_filtops; 790 sysfilt_ops[~filt].for_refcnt = 0; 791 } 792 mtx_unlock(&filterops_lock); 793 794 return error; 795 } 796 797 static struct filterops * 798 kqueue_fo_find(int filt) 799 { 800 801 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 802 return NULL; 803 804 mtx_lock(&filterops_lock); 805 sysfilt_ops[~filt].for_refcnt++; 806 if (sysfilt_ops[~filt].for_fop == NULL) 807 sysfilt_ops[~filt].for_fop = &null_filtops; 808 mtx_unlock(&filterops_lock); 809 810 return sysfilt_ops[~filt].for_fop; 811 } 812 813 static void 814 kqueue_fo_release(int filt) 815 { 816 817 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 818 return; 819 820 mtx_lock(&filterops_lock); 821 KASSERT(sysfilt_ops[~filt].for_refcnt > 0, 822 ("filter object refcount not valid on release")); 823 sysfilt_ops[~filt].for_refcnt--; 824 mtx_unlock(&filterops_lock); 825 } 826 827 /* 828 * A ref to kq (obtained via kqueue_acquire) must be held. waitok will 829 * influence if memory allocation should wait. Make sure it is 0 if you 830 * hold any mutexes. 831 */ 832 static int 833 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, int waitok) 834 { 835 struct filterops *fops; 836 struct file *fp; 837 struct knote *kn, *tkn; 838 int error, filt, event; 839 int haskqglobal; 840 841 fp = NULL; 842 kn = NULL; 843 error = 0; 844 haskqglobal = 0; 845 846 filt = kev->filter; 847 fops = kqueue_fo_find(filt); 848 if (fops == NULL) 849 return EINVAL; 850 851 tkn = knote_alloc(waitok); /* prevent waiting with locks */ 852 853 findkn: 854 if (fops->f_isfd) { 855 KASSERT(td != NULL, ("td is NULL")); 856 error = fget(td, kev->ident, &fp); 857 if (error) 858 goto done; 859 860 if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops, 861 kev->ident, 0) != 0) { 862 /* try again */ 863 fdrop(fp, td); 864 fp = NULL; 865 error = kqueue_expand(kq, fops, kev->ident, waitok); 866 if (error) 867 goto done; 868 goto findkn; 869 } 870 871 if (fp->f_type == DTYPE_KQUEUE) { 872 /* 873 * if we add some inteligence about what we are doing, 874 * we should be able to support events on ourselves. 875 * We need to know when we are doing this to prevent 876 * getting both the knlist lock and the kq lock since 877 * they are the same thing. 878 */ 879 if (fp->f_data == kq) { 880 error = EINVAL; 881 goto done; 882 } 883 884 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 885 } 886 887 KQ_LOCK(kq); 888 if (kev->ident < kq->kq_knlistsize) { 889 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link) 890 if (kev->filter == kn->kn_filter) 891 break; 892 } 893 } else { 894 if ((kev->flags & EV_ADD) == EV_ADD) 895 kqueue_expand(kq, fops, kev->ident, waitok); 896 897 KQ_LOCK(kq); 898 if (kq->kq_knhashmask != 0) { 899 struct klist *list; 900 901 list = &kq->kq_knhash[ 902 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)]; 903 SLIST_FOREACH(kn, list, kn_link) 904 if (kev->ident == kn->kn_id && 905 kev->filter == kn->kn_filter) 906 break; 907 } 908 } 909 910 /* knote is in the process of changing, wait for it to stablize. */ 911 if (kn != NULL && (kn->kn_status & KN_INFLUX) == KN_INFLUX) { 912 if (fp != NULL) { 913 fdrop(fp, td); 914 fp = NULL; 915 } 916 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 917 kq->kq_state |= KQ_FLUXWAIT; 918 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0); 919 goto findkn; 920 } 921 922 if (kn == NULL && ((kev->flags & EV_ADD) == 0)) { 923 KQ_UNLOCK(kq); 924 error = ENOENT; 925 goto done; 926 } 927 928 /* 929 * kn now contains the matching knote, or NULL if no match 930 */ 931 if (kev->flags & EV_ADD) { 932 if (kn == NULL) { 933 kn = tkn; 934 tkn = NULL; 935 if (kn == NULL) { 936 KQ_UNLOCK(kq); 937 error = ENOMEM; 938 goto done; 939 } 940 kn->kn_fp = fp; 941 kn->kn_kq = kq; 942 kn->kn_fop = fops; 943 /* 944 * apply reference counts to knote structure, and 945 * do not release it at the end of this routine. 946 */ 947 fops = NULL; 948 fp = NULL; 949 950 kn->kn_sfflags = kev->fflags; 951 kn->kn_sdata = kev->data; 952 kev->fflags = 0; 953 kev->data = 0; 954 kn->kn_kevent = *kev; 955 kn->kn_kevent.flags &= ~(EV_ADD | EV_DELETE | 956 EV_ENABLE | EV_DISABLE); 957 kn->kn_status = KN_INFLUX|KN_DETACHED; 958 959 error = knote_attach(kn, kq); 960 KQ_UNLOCK(kq); 961 if (error != 0) { 962 tkn = kn; 963 goto done; 964 } 965 966 if ((error = kn->kn_fop->f_attach(kn)) != 0) { 967 knote_drop(kn, td); 968 goto done; 969 } 970 KN_LIST_LOCK(kn); 971 } else { 972 /* 973 * The user may change some filter values after the 974 * initial EV_ADD, but doing so will not reset any 975 * filter which has already been triggered. 976 */ 977 kn->kn_status |= KN_INFLUX; 978 KQ_UNLOCK(kq); 979 KN_LIST_LOCK(kn); 980 kn->kn_sfflags = kev->fflags; 981 kn->kn_sdata = kev->data; 982 kn->kn_kevent.udata = kev->udata; 983 } 984 985 /* 986 * We can get here with kn->kn_knlist == NULL. 987 * This can happen when the initial attach event decides that 988 * the event is "completed" already. i.e. filt_procattach 989 * is called on a zombie process. It will call filt_proc 990 * which will remove it from the list, and NULL kn_knlist. 991 */ 992 event = kn->kn_fop->f_event(kn, 0); 993 KQ_LOCK(kq); 994 if (event) 995 KNOTE_ACTIVATE(kn, 1); 996 kn->kn_status &= ~KN_INFLUX; 997 KN_LIST_UNLOCK(kn); 998 } else if (kev->flags & EV_DELETE) { 999 kn->kn_status |= KN_INFLUX; 1000 KQ_UNLOCK(kq); 1001 if (!(kn->kn_status & KN_DETACHED)) 1002 kn->kn_fop->f_detach(kn); 1003 knote_drop(kn, td); 1004 goto done; 1005 } 1006 1007 if ((kev->flags & EV_DISABLE) && 1008 ((kn->kn_status & KN_DISABLED) == 0)) { 1009 kn->kn_status |= KN_DISABLED; 1010 } 1011 1012 if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) { 1013 kn->kn_status &= ~KN_DISABLED; 1014 if ((kn->kn_status & KN_ACTIVE) && 1015 ((kn->kn_status & KN_QUEUED) == 0)) 1016 knote_enqueue(kn); 1017 } 1018 KQ_UNLOCK_FLUX(kq); 1019 1020 done: 1021 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1022 if (fp != NULL) 1023 fdrop(fp, td); 1024 if (tkn != NULL) 1025 knote_free(tkn); 1026 if (fops != NULL) 1027 kqueue_fo_release(filt); 1028 return (error); 1029 } 1030 1031 static int 1032 kqueue_acquire(struct file *fp, struct kqueue **kqp) 1033 { 1034 int error; 1035 struct kqueue *kq; 1036 1037 error = 0; 1038 1039 kq = fp->f_data; 1040 if (fp->f_type != DTYPE_KQUEUE || kq == NULL) 1041 return (EBADF); 1042 *kqp = kq; 1043 KQ_LOCK(kq); 1044 if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) { 1045 KQ_UNLOCK(kq); 1046 return (EBADF); 1047 } 1048 kq->kq_refcnt++; 1049 KQ_UNLOCK(kq); 1050 1051 return error; 1052 } 1053 1054 static void 1055 kqueue_release(struct kqueue *kq, int locked) 1056 { 1057 if (locked) 1058 KQ_OWNED(kq); 1059 else 1060 KQ_LOCK(kq); 1061 kq->kq_refcnt--; 1062 if (kq->kq_refcnt == 1) 1063 wakeup(&kq->kq_refcnt); 1064 if (!locked) 1065 KQ_UNLOCK(kq); 1066 } 1067 1068 static void 1069 kqueue_schedtask(struct kqueue *kq) 1070 { 1071 1072 KQ_OWNED(kq); 1073 KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN), 1074 ("scheduling kqueue task while draining")); 1075 1076 if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) { 1077 taskqueue_enqueue(taskqueue_kqueue, &kq->kq_task); 1078 kq->kq_state |= KQ_TASKSCHED; 1079 } 1080 } 1081 1082 /* 1083 * Expand the kq to make sure we have storage for fops/ident pair. 1084 * 1085 * Return 0 on success (or no work necessary), return errno on failure. 1086 * 1087 * Not calling hashinit w/ waitok (proper malloc flag) should be safe. 1088 * If kqueue_register is called from a non-fd context, there usually/should 1089 * be no locks held. 1090 */ 1091 static int 1092 kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident, 1093 int waitok) 1094 { 1095 struct klist *list, *tmp_knhash; 1096 u_long tmp_knhashmask; 1097 int size; 1098 int fd; 1099 int mflag = waitok ? M_WAITOK : M_NOWAIT; 1100 1101 KQ_NOTOWNED(kq); 1102 1103 if (fops->f_isfd) { 1104 fd = ident; 1105 if (kq->kq_knlistsize <= fd) { 1106 size = kq->kq_knlistsize; 1107 while (size <= fd) 1108 size += KQEXTENT; 1109 list = malloc(size * sizeof list, M_KQUEUE, mflag); 1110 if (list == NULL) 1111 return ENOMEM; 1112 KQ_LOCK(kq); 1113 if (kq->kq_knlistsize > fd) { 1114 free(list, M_KQUEUE); 1115 list = NULL; 1116 } else { 1117 if (kq->kq_knlist != NULL) { 1118 bcopy(kq->kq_knlist, list, 1119 kq->kq_knlistsize * sizeof list); 1120 free(kq->kq_knlist, M_KQUEUE); 1121 kq->kq_knlist = NULL; 1122 } 1123 bzero((caddr_t)list + 1124 kq->kq_knlistsize * sizeof list, 1125 (size - kq->kq_knlistsize) * sizeof list); 1126 kq->kq_knlistsize = size; 1127 kq->kq_knlist = list; 1128 } 1129 KQ_UNLOCK(kq); 1130 } 1131 } else { 1132 if (kq->kq_knhashmask == 0) { 1133 tmp_knhash = hashinit(KN_HASHSIZE, M_KQUEUE, 1134 &tmp_knhashmask); 1135 if (tmp_knhash == NULL) 1136 return ENOMEM; 1137 KQ_LOCK(kq); 1138 if (kq->kq_knhashmask == 0) { 1139 kq->kq_knhash = tmp_knhash; 1140 kq->kq_knhashmask = tmp_knhashmask; 1141 } else { 1142 free(tmp_knhash, M_KQUEUE); 1143 } 1144 KQ_UNLOCK(kq); 1145 } 1146 } 1147 1148 KQ_NOTOWNED(kq); 1149 return 0; 1150 } 1151 1152 static void 1153 kqueue_task(void *arg, int pending) 1154 { 1155 struct kqueue *kq; 1156 int haskqglobal; 1157 1158 haskqglobal = 0; 1159 kq = arg; 1160 1161 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1162 KQ_LOCK(kq); 1163 1164 KNOTE_LOCKED(&kq->kq_sel.si_note, 0); 1165 1166 kq->kq_state &= ~KQ_TASKSCHED; 1167 if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) { 1168 wakeup(&kq->kq_state); 1169 } 1170 KQ_UNLOCK(kq); 1171 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1172 } 1173 1174 /* 1175 * Scan, update kn_data (if not ONESHOT), and copyout triggered events. 1176 * We treat KN_MARKER knotes as if they are INFLUX. 1177 */ 1178 static int 1179 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops, 1180 const struct timespec *tsp, struct kevent *keva, struct thread *td) 1181 { 1182 struct kevent *kevp; 1183 struct timeval atv, rtv, ttv; 1184 struct knote *kn, *marker; 1185 int count, timeout, nkev, error, influx; 1186 int haskqglobal; 1187 1188 count = maxevents; 1189 nkev = 0; 1190 error = 0; 1191 haskqglobal = 0; 1192 1193 if (maxevents == 0) 1194 goto done_nl; 1195 1196 if (tsp != NULL) { 1197 TIMESPEC_TO_TIMEVAL(&atv, tsp); 1198 if (itimerfix(&atv)) { 1199 error = EINVAL; 1200 goto done_nl; 1201 } 1202 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) 1203 timeout = -1; 1204 else 1205 timeout = atv.tv_sec > 24 * 60 * 60 ? 1206 24 * 60 * 60 * hz : tvtohz(&atv); 1207 getmicrouptime(&rtv); 1208 timevaladd(&atv, &rtv); 1209 } else { 1210 atv.tv_sec = 0; 1211 atv.tv_usec = 0; 1212 timeout = 0; 1213 } 1214 marker = knote_alloc(1); 1215 if (marker == NULL) { 1216 error = ENOMEM; 1217 goto done_nl; 1218 } 1219 marker->kn_status = KN_MARKER; 1220 KQ_LOCK(kq); 1221 goto start; 1222 1223 retry: 1224 if (atv.tv_sec || atv.tv_usec) { 1225 getmicrouptime(&rtv); 1226 if (timevalcmp(&rtv, &atv, >=)) 1227 goto done; 1228 ttv = atv; 1229 timevalsub(&ttv, &rtv); 1230 timeout = ttv.tv_sec > 24 * 60 * 60 ? 1231 24 * 60 * 60 * hz : tvtohz(&ttv); 1232 } 1233 1234 start: 1235 kevp = keva; 1236 if (kq->kq_count == 0) { 1237 if (timeout < 0) { 1238 error = EWOULDBLOCK; 1239 } else { 1240 kq->kq_state |= KQ_SLEEP; 1241 error = msleep(kq, &kq->kq_lock, PSOCK | PCATCH, 1242 "kqread", timeout); 1243 } 1244 if (error == 0) 1245 goto retry; 1246 /* don't restart after signals... */ 1247 if (error == ERESTART) 1248 error = EINTR; 1249 else if (error == EWOULDBLOCK) 1250 error = 0; 1251 goto done; 1252 } 1253 1254 TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); 1255 influx = 0; 1256 while (count) { 1257 KQ_OWNED(kq); 1258 kn = TAILQ_FIRST(&kq->kq_head); 1259 1260 if ((kn->kn_status == KN_MARKER && kn != marker) || 1261 (kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1262 if (influx) { 1263 influx = 0; 1264 KQ_FLUX_WAKEUP(kq); 1265 } 1266 kq->kq_state |= KQ_FLUXWAIT; 1267 error = msleep(kq, &kq->kq_lock, PSOCK, 1268 "kqflxwt", 0); 1269 continue; 1270 } 1271 1272 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1273 if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) { 1274 kn->kn_status &= ~KN_QUEUED; 1275 kq->kq_count--; 1276 continue; 1277 } 1278 if (kn == marker) { 1279 KQ_FLUX_WAKEUP(kq); 1280 if (count == maxevents) 1281 goto retry; 1282 goto done; 1283 } 1284 KASSERT((kn->kn_status & KN_INFLUX) == 0, 1285 ("KN_INFLUX set when not suppose to be")); 1286 1287 if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) { 1288 kn->kn_status &= ~KN_QUEUED; 1289 kn->kn_status |= KN_INFLUX; 1290 kq->kq_count--; 1291 KQ_UNLOCK(kq); 1292 /* 1293 * We don't need to lock the list since we've marked 1294 * it _INFLUX. 1295 */ 1296 *kevp = kn->kn_kevent; 1297 if (!(kn->kn_status & KN_DETACHED)) 1298 kn->kn_fop->f_detach(kn); 1299 knote_drop(kn, td); 1300 KQ_LOCK(kq); 1301 kn = NULL; 1302 } else { 1303 kn->kn_status |= KN_INFLUX; 1304 KQ_UNLOCK(kq); 1305 if ((kn->kn_status & KN_KQUEUE) == KN_KQUEUE) 1306 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1307 KN_LIST_LOCK(kn); 1308 if (kn->kn_fop->f_event(kn, 0) == 0) { 1309 KQ_LOCK(kq); 1310 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1311 kn->kn_status &= 1312 ~(KN_QUEUED | KN_ACTIVE | KN_INFLUX); 1313 kq->kq_count--; 1314 KN_LIST_UNLOCK(kn); 1315 influx = 1; 1316 continue; 1317 } 1318 *kevp = kn->kn_kevent; 1319 KQ_LOCK(kq); 1320 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1321 if (kn->kn_flags & EV_CLEAR) { 1322 kn->kn_data = 0; 1323 kn->kn_fflags = 0; 1324 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 1325 kq->kq_count--; 1326 } else 1327 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 1328 1329 kn->kn_status &= ~(KN_INFLUX); 1330 KN_LIST_UNLOCK(kn); 1331 influx = 1; 1332 } 1333 1334 /* we are returning a copy to the user */ 1335 kevp++; 1336 nkev++; 1337 count--; 1338 1339 if (nkev == KQ_NEVENTS) { 1340 influx = 0; 1341 KQ_UNLOCK_FLUX(kq); 1342 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1343 nkev = 0; 1344 kevp = keva; 1345 KQ_LOCK(kq); 1346 if (error) 1347 break; 1348 } 1349 } 1350 TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); 1351 done: 1352 KQ_OWNED(kq); 1353 KQ_UNLOCK_FLUX(kq); 1354 knote_free(marker); 1355 done_nl: 1356 KQ_NOTOWNED(kq); 1357 if (nkev != 0) 1358 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1359 td->td_retval[0] = maxevents - count; 1360 return (error); 1361 } 1362 1363 /* 1364 * XXX 1365 * This could be expanded to call kqueue_scan, if desired. 1366 */ 1367 /*ARGSUSED*/ 1368 static int 1369 kqueue_read(struct file *fp, struct uio *uio, struct ucred *active_cred, 1370 int flags, struct thread *td) 1371 { 1372 return (ENXIO); 1373 } 1374 1375 /*ARGSUSED*/ 1376 static int 1377 kqueue_write(struct file *fp, struct uio *uio, struct ucred *active_cred, 1378 int flags, struct thread *td) 1379 { 1380 return (ENXIO); 1381 } 1382 1383 /*ARGSUSED*/ 1384 static int 1385 kqueue_truncate(struct file *fp, off_t length, struct ucred *active_cred, 1386 struct thread *td) 1387 { 1388 1389 return (EINVAL); 1390 } 1391 1392 /*ARGSUSED*/ 1393 static int 1394 kqueue_ioctl(struct file *fp, u_long cmd, void *data, 1395 struct ucred *active_cred, struct thread *td) 1396 { 1397 /* 1398 * Enabling sigio causes two major problems: 1399 * 1) infinite recursion: 1400 * Synopsys: kevent is being used to track signals and have FIOASYNC 1401 * set. On receipt of a signal this will cause a kqueue to recurse 1402 * into itself over and over. Sending the sigio causes the kqueue 1403 * to become ready, which in turn posts sigio again, forever. 1404 * Solution: this can be solved by setting a flag in the kqueue that 1405 * we have a SIGIO in progress. 1406 * 2) locking problems: 1407 * Synopsys: Kqueue is a leaf subsystem, but adding signalling puts 1408 * us above the proc and pgrp locks. 1409 * Solution: Post a signal using an async mechanism, being sure to 1410 * record a generation count in the delivery so that we do not deliver 1411 * a signal to the wrong process. 1412 * 1413 * Note, these two mechanisms are somewhat mutually exclusive! 1414 */ 1415 #if 0 1416 struct kqueue *kq; 1417 1418 kq = fp->f_data; 1419 switch (cmd) { 1420 case FIOASYNC: 1421 if (*(int *)data) { 1422 kq->kq_state |= KQ_ASYNC; 1423 } else { 1424 kq->kq_state &= ~KQ_ASYNC; 1425 } 1426 return (0); 1427 1428 case FIOSETOWN: 1429 return (fsetown(*(int *)data, &kq->kq_sigio)); 1430 1431 case FIOGETOWN: 1432 *(int *)data = fgetown(&kq->kq_sigio); 1433 return (0); 1434 } 1435 #endif 1436 1437 return (ENOTTY); 1438 } 1439 1440 /*ARGSUSED*/ 1441 static int 1442 kqueue_poll(struct file *fp, int events, struct ucred *active_cred, 1443 struct thread *td) 1444 { 1445 struct kqueue *kq; 1446 int revents = 0; 1447 int error; 1448 1449 if ((error = kqueue_acquire(fp, &kq))) 1450 return POLLERR; 1451 1452 KQ_LOCK(kq); 1453 if (events & (POLLIN | POLLRDNORM)) { 1454 if (kq->kq_count) { 1455 revents |= events & (POLLIN | POLLRDNORM); 1456 } else { 1457 selrecord(td, &kq->kq_sel); 1458 if (SEL_WAITING(&kq->kq_sel)) 1459 kq->kq_state |= KQ_SEL; 1460 } 1461 } 1462 kqueue_release(kq, 1); 1463 KQ_UNLOCK(kq); 1464 return (revents); 1465 } 1466 1467 /*ARGSUSED*/ 1468 static int 1469 kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred, 1470 struct thread *td) 1471 { 1472 1473 bzero((void *)st, sizeof *st); 1474 /* 1475 * We no longer return kq_count because the unlocked value is useless. 1476 * If you spent all this time getting the count, why not spend your 1477 * syscall better by calling kevent? 1478 * 1479 * XXX - This is needed for libc_r. 1480 */ 1481 st->st_mode = S_IFIFO; 1482 return (0); 1483 } 1484 1485 /*ARGSUSED*/ 1486 static int 1487 kqueue_close(struct file *fp, struct thread *td) 1488 { 1489 struct kqueue *kq = fp->f_data; 1490 struct filedesc *fdp; 1491 struct knote *kn; 1492 int i; 1493 int error; 1494 1495 if ((error = kqueue_acquire(fp, &kq))) 1496 return error; 1497 1498 KQ_LOCK(kq); 1499 1500 KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING, 1501 ("kqueue already closing")); 1502 kq->kq_state |= KQ_CLOSING; 1503 if (kq->kq_refcnt > 1) 1504 msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0); 1505 1506 KASSERT(kq->kq_refcnt == 1, ("other refs are out there!")); 1507 fdp = kq->kq_fdp; 1508 1509 KASSERT(knlist_empty(&kq->kq_sel.si_note), 1510 ("kqueue's knlist not empty")); 1511 1512 for (i = 0; i < kq->kq_knlistsize; i++) { 1513 while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) { 1514 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1515 kq->kq_state |= KQ_FLUXWAIT; 1516 msleep(kq, &kq->kq_lock, PSOCK, "kqclo1", 0); 1517 continue; 1518 } 1519 kn->kn_status |= KN_INFLUX; 1520 KQ_UNLOCK(kq); 1521 if (!(kn->kn_status & KN_DETACHED)) 1522 kn->kn_fop->f_detach(kn); 1523 knote_drop(kn, td); 1524 KQ_LOCK(kq); 1525 } 1526 } 1527 if (kq->kq_knhashmask != 0) { 1528 for (i = 0; i <= kq->kq_knhashmask; i++) { 1529 while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) { 1530 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1531 kq->kq_state |= KQ_FLUXWAIT; 1532 msleep(kq, &kq->kq_lock, PSOCK, 1533 "kqclo2", 0); 1534 continue; 1535 } 1536 kn->kn_status |= KN_INFLUX; 1537 KQ_UNLOCK(kq); 1538 if (!(kn->kn_status & KN_DETACHED)) 1539 kn->kn_fop->f_detach(kn); 1540 knote_drop(kn, td); 1541 KQ_LOCK(kq); 1542 } 1543 } 1544 } 1545 1546 if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) { 1547 kq->kq_state |= KQ_TASKDRAIN; 1548 msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0); 1549 } 1550 1551 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 1552 selwakeuppri(&kq->kq_sel, PSOCK); 1553 if (!SEL_WAITING(&kq->kq_sel)) 1554 kq->kq_state &= ~KQ_SEL; 1555 } 1556 1557 KQ_UNLOCK(kq); 1558 1559 FILEDESC_XLOCK(fdp); 1560 SLIST_REMOVE(&fdp->fd_kqlist, kq, kqueue, kq_list); 1561 FILEDESC_XUNLOCK(fdp); 1562 1563 knlist_destroy(&kq->kq_sel.si_note); 1564 mtx_destroy(&kq->kq_lock); 1565 kq->kq_fdp = NULL; 1566 1567 if (kq->kq_knhash != NULL) 1568 free(kq->kq_knhash, M_KQUEUE); 1569 if (kq->kq_knlist != NULL) 1570 free(kq->kq_knlist, M_KQUEUE); 1571 1572 funsetown(&kq->kq_sigio); 1573 free(kq, M_KQUEUE); 1574 fp->f_data = NULL; 1575 1576 return (0); 1577 } 1578 1579 static void 1580 kqueue_wakeup(struct kqueue *kq) 1581 { 1582 KQ_OWNED(kq); 1583 1584 if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) { 1585 kq->kq_state &= ~KQ_SLEEP; 1586 wakeup(kq); 1587 } 1588 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 1589 selwakeuppri(&kq->kq_sel, PSOCK); 1590 if (!SEL_WAITING(&kq->kq_sel)) 1591 kq->kq_state &= ~KQ_SEL; 1592 } 1593 if (!knlist_empty(&kq->kq_sel.si_note)) 1594 kqueue_schedtask(kq); 1595 if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) { 1596 pgsigio(&kq->kq_sigio, SIGIO, 0); 1597 } 1598 } 1599 1600 /* 1601 * Walk down a list of knotes, activating them if their event has triggered. 1602 * 1603 * There is a possibility to optimize in the case of one kq watching another. 1604 * Instead of scheduling a task to wake it up, you could pass enough state 1605 * down the chain to make up the parent kqueue. Make this code functional 1606 * first. 1607 */ 1608 void 1609 knote(struct knlist *list, long hint, int lockflags) 1610 { 1611 struct kqueue *kq; 1612 struct knote *kn; 1613 int error; 1614 1615 if (list == NULL) 1616 return; 1617 1618 KNL_ASSERT_LOCK(list, lockflags & KNF_LISTLOCKED); 1619 1620 if ((lockflags & KNF_LISTLOCKED) == 0) 1621 list->kl_lock(list->kl_lockarg); 1622 1623 /* 1624 * If we unlock the list lock (and set KN_INFLUX), we can eliminate 1625 * the kqueue scheduling, but this will introduce four 1626 * lock/unlock's for each knote to test. If we do, continue to use 1627 * SLIST_FOREACH, SLIST_FOREACH_SAFE is not safe in our case, it is 1628 * only safe if you want to remove the current item, which we are 1629 * not doing. 1630 */ 1631 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { 1632 kq = kn->kn_kq; 1633 if ((kn->kn_status & KN_INFLUX) != KN_INFLUX) { 1634 KQ_LOCK(kq); 1635 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1636 KQ_UNLOCK(kq); 1637 } else if ((lockflags & KNF_NOKQLOCK) != 0) { 1638 kn->kn_status |= KN_INFLUX; 1639 KQ_UNLOCK(kq); 1640 error = kn->kn_fop->f_event(kn, hint); 1641 KQ_LOCK(kq); 1642 kn->kn_status &= ~KN_INFLUX; 1643 if (error) 1644 KNOTE_ACTIVATE(kn, 1); 1645 KQ_UNLOCK_FLUX(kq); 1646 } else { 1647 kn->kn_status |= KN_HASKQLOCK; 1648 if (kn->kn_fop->f_event(kn, hint)) 1649 KNOTE_ACTIVATE(kn, 1); 1650 kn->kn_status &= ~KN_HASKQLOCK; 1651 KQ_UNLOCK(kq); 1652 } 1653 } 1654 kq = NULL; 1655 } 1656 if ((lockflags & KNF_LISTLOCKED) == 0) 1657 list->kl_unlock(list->kl_lockarg); 1658 } 1659 1660 /* 1661 * add a knote to a knlist 1662 */ 1663 void 1664 knlist_add(struct knlist *knl, struct knote *kn, int islocked) 1665 { 1666 KNL_ASSERT_LOCK(knl, islocked); 1667 KQ_NOTOWNED(kn->kn_kq); 1668 KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) == 1669 (KN_INFLUX|KN_DETACHED), ("knote not KN_INFLUX and KN_DETACHED")); 1670 if (!islocked) 1671 knl->kl_lock(knl->kl_lockarg); 1672 SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext); 1673 if (!islocked) 1674 knl->kl_unlock(knl->kl_lockarg); 1675 KQ_LOCK(kn->kn_kq); 1676 kn->kn_knlist = knl; 1677 kn->kn_status &= ~KN_DETACHED; 1678 KQ_UNLOCK(kn->kn_kq); 1679 } 1680 1681 static void 1682 knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked, int kqislocked) 1683 { 1684 KASSERT(!(!!kqislocked && !knlislocked), ("kq locked w/o knl locked")); 1685 KNL_ASSERT_LOCK(knl, knlislocked); 1686 mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED); 1687 if (!kqislocked) 1688 KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) == KN_INFLUX, 1689 ("knlist_remove called w/o knote being KN_INFLUX or already removed")); 1690 if (!knlislocked) 1691 knl->kl_lock(knl->kl_lockarg); 1692 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext); 1693 kn->kn_knlist = NULL; 1694 if (!knlislocked) 1695 knl->kl_unlock(knl->kl_lockarg); 1696 if (!kqislocked) 1697 KQ_LOCK(kn->kn_kq); 1698 kn->kn_status |= KN_DETACHED; 1699 if (!kqislocked) 1700 KQ_UNLOCK(kn->kn_kq); 1701 } 1702 1703 /* 1704 * remove all knotes from a specified klist 1705 */ 1706 void 1707 knlist_remove(struct knlist *knl, struct knote *kn, int islocked) 1708 { 1709 1710 knlist_remove_kq(knl, kn, islocked, 0); 1711 } 1712 1713 /* 1714 * remove knote from a specified klist while in f_event handler. 1715 */ 1716 void 1717 knlist_remove_inevent(struct knlist *knl, struct knote *kn) 1718 { 1719 1720 knlist_remove_kq(knl, kn, 1, 1721 (kn->kn_status & KN_HASKQLOCK) == KN_HASKQLOCK); 1722 } 1723 1724 int 1725 knlist_empty(struct knlist *knl) 1726 { 1727 KNL_ASSERT_LOCKED(knl); 1728 return SLIST_EMPTY(&knl->kl_list); 1729 } 1730 1731 static struct mtx knlist_lock; 1732 MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects", 1733 MTX_DEF); 1734 static void knlist_mtx_lock(void *arg); 1735 static void knlist_mtx_unlock(void *arg); 1736 1737 static void 1738 knlist_mtx_lock(void *arg) 1739 { 1740 mtx_lock((struct mtx *)arg); 1741 } 1742 1743 static void 1744 knlist_mtx_unlock(void *arg) 1745 { 1746 mtx_unlock((struct mtx *)arg); 1747 } 1748 1749 static void 1750 knlist_mtx_assert_locked(void *arg) 1751 { 1752 mtx_assert((struct mtx *)arg, MA_OWNED); 1753 } 1754 1755 static void 1756 knlist_mtx_assert_unlocked(void *arg) 1757 { 1758 mtx_assert((struct mtx *)arg, MA_NOTOWNED); 1759 } 1760 1761 void 1762 knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *), 1763 void (*kl_unlock)(void *), 1764 void (*kl_assert_locked)(void *), void (*kl_assert_unlocked)(void *)) 1765 { 1766 1767 if (lock == NULL) 1768 knl->kl_lockarg = &knlist_lock; 1769 else 1770 knl->kl_lockarg = lock; 1771 1772 if (kl_lock == NULL) 1773 knl->kl_lock = knlist_mtx_lock; 1774 else 1775 knl->kl_lock = kl_lock; 1776 if (kl_unlock == NULL) 1777 knl->kl_unlock = knlist_mtx_unlock; 1778 else 1779 knl->kl_unlock = kl_unlock; 1780 if (kl_assert_locked == NULL) 1781 knl->kl_assert_locked = knlist_mtx_assert_locked; 1782 else 1783 knl->kl_assert_locked = kl_assert_locked; 1784 if (kl_assert_unlocked == NULL) 1785 knl->kl_assert_unlocked = knlist_mtx_assert_unlocked; 1786 else 1787 knl->kl_assert_unlocked = kl_assert_unlocked; 1788 1789 SLIST_INIT(&knl->kl_list); 1790 } 1791 1792 void 1793 knlist_init_mtx(struct knlist *knl, struct mtx *lock) 1794 { 1795 1796 knlist_init(knl, lock, NULL, NULL, NULL, NULL); 1797 } 1798 1799 void 1800 knlist_destroy(struct knlist *knl) 1801 { 1802 1803 #ifdef INVARIANTS 1804 /* 1805 * if we run across this error, we need to find the offending 1806 * driver and have it call knlist_clear. 1807 */ 1808 if (!SLIST_EMPTY(&knl->kl_list)) 1809 printf("WARNING: destroying knlist w/ knotes on it!\n"); 1810 #endif 1811 1812 knl->kl_lockarg = knl->kl_lock = knl->kl_unlock = NULL; 1813 SLIST_INIT(&knl->kl_list); 1814 } 1815 1816 /* 1817 * Even if we are locked, we may need to drop the lock to allow any influx 1818 * knotes time to "settle". 1819 */ 1820 void 1821 knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn) 1822 { 1823 struct knote *kn, *kn2; 1824 struct kqueue *kq; 1825 1826 if (islocked) 1827 KNL_ASSERT_LOCKED(knl); 1828 else { 1829 KNL_ASSERT_UNLOCKED(knl); 1830 again: /* need to reacquire lock since we have dropped it */ 1831 knl->kl_lock(knl->kl_lockarg); 1832 } 1833 1834 SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) { 1835 kq = kn->kn_kq; 1836 KQ_LOCK(kq); 1837 if ((kn->kn_status & KN_INFLUX)) { 1838 KQ_UNLOCK(kq); 1839 continue; 1840 } 1841 knlist_remove_kq(knl, kn, 1, 1); 1842 if (killkn) { 1843 kn->kn_status |= KN_INFLUX | KN_DETACHED; 1844 KQ_UNLOCK(kq); 1845 knote_drop(kn, td); 1846 } else { 1847 /* Make sure cleared knotes disappear soon */ 1848 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 1849 KQ_UNLOCK(kq); 1850 } 1851 kq = NULL; 1852 } 1853 1854 if (!SLIST_EMPTY(&knl->kl_list)) { 1855 /* there are still KN_INFLUX remaining */ 1856 kn = SLIST_FIRST(&knl->kl_list); 1857 kq = kn->kn_kq; 1858 KQ_LOCK(kq); 1859 KASSERT(kn->kn_status & KN_INFLUX, 1860 ("knote removed w/o list lock")); 1861 knl->kl_unlock(knl->kl_lockarg); 1862 kq->kq_state |= KQ_FLUXWAIT; 1863 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0); 1864 kq = NULL; 1865 goto again; 1866 } 1867 1868 if (islocked) 1869 KNL_ASSERT_LOCKED(knl); 1870 else { 1871 knl->kl_unlock(knl->kl_lockarg); 1872 KNL_ASSERT_UNLOCKED(knl); 1873 } 1874 } 1875 1876 /* 1877 * Remove all knotes referencing a specified fd must be called with FILEDESC 1878 * lock. This prevents a race where a new fd comes along and occupies the 1879 * entry and we attach a knote to the fd. 1880 */ 1881 void 1882 knote_fdclose(struct thread *td, int fd) 1883 { 1884 struct filedesc *fdp = td->td_proc->p_fd; 1885 struct kqueue *kq; 1886 struct knote *kn; 1887 int influx; 1888 1889 FILEDESC_XLOCK_ASSERT(fdp); 1890 1891 /* 1892 * We shouldn't have to worry about new kevents appearing on fd 1893 * since filedesc is locked. 1894 */ 1895 SLIST_FOREACH(kq, &fdp->fd_kqlist, kq_list) { 1896 KQ_LOCK(kq); 1897 1898 again: 1899 influx = 0; 1900 while (kq->kq_knlistsize > fd && 1901 (kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) { 1902 if (kn->kn_status & KN_INFLUX) { 1903 /* someone else might be waiting on our knote */ 1904 if (influx) 1905 wakeup(kq); 1906 kq->kq_state |= KQ_FLUXWAIT; 1907 msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0); 1908 goto again; 1909 } 1910 kn->kn_status |= KN_INFLUX; 1911 KQ_UNLOCK(kq); 1912 if (!(kn->kn_status & KN_DETACHED)) 1913 kn->kn_fop->f_detach(kn); 1914 knote_drop(kn, td); 1915 influx = 1; 1916 KQ_LOCK(kq); 1917 } 1918 KQ_UNLOCK_FLUX(kq); 1919 } 1920 } 1921 1922 static int 1923 knote_attach(struct knote *kn, struct kqueue *kq) 1924 { 1925 struct klist *list; 1926 1927 KASSERT(kn->kn_status & KN_INFLUX, ("knote not marked INFLUX")); 1928 KQ_OWNED(kq); 1929 1930 if (kn->kn_fop->f_isfd) { 1931 if (kn->kn_id >= kq->kq_knlistsize) 1932 return ENOMEM; 1933 list = &kq->kq_knlist[kn->kn_id]; 1934 } else { 1935 if (kq->kq_knhash == NULL) 1936 return ENOMEM; 1937 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 1938 } 1939 1940 SLIST_INSERT_HEAD(list, kn, kn_link); 1941 1942 return 0; 1943 } 1944 1945 /* 1946 * knote must already have been detached using the f_detach method. 1947 * no lock need to be held, it is assumed that the KN_INFLUX flag is set 1948 * to prevent other removal. 1949 */ 1950 static void 1951 knote_drop(struct knote *kn, struct thread *td) 1952 { 1953 struct kqueue *kq; 1954 struct klist *list; 1955 1956 kq = kn->kn_kq; 1957 1958 KQ_NOTOWNED(kq); 1959 KASSERT((kn->kn_status & KN_INFLUX) == KN_INFLUX, 1960 ("knote_drop called without KN_INFLUX set in kn_status")); 1961 1962 KQ_LOCK(kq); 1963 if (kn->kn_fop->f_isfd) 1964 list = &kq->kq_knlist[kn->kn_id]; 1965 else 1966 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 1967 1968 if (!SLIST_EMPTY(list)) 1969 SLIST_REMOVE(list, kn, knote, kn_link); 1970 if (kn->kn_status & KN_QUEUED) 1971 knote_dequeue(kn); 1972 KQ_UNLOCK_FLUX(kq); 1973 1974 if (kn->kn_fop->f_isfd) { 1975 fdrop(kn->kn_fp, td); 1976 kn->kn_fp = NULL; 1977 } 1978 kqueue_fo_release(kn->kn_kevent.filter); 1979 kn->kn_fop = NULL; 1980 knote_free(kn); 1981 } 1982 1983 static void 1984 knote_enqueue(struct knote *kn) 1985 { 1986 struct kqueue *kq = kn->kn_kq; 1987 1988 KQ_OWNED(kn->kn_kq); 1989 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 1990 1991 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 1992 kn->kn_status |= KN_QUEUED; 1993 kq->kq_count++; 1994 kqueue_wakeup(kq); 1995 } 1996 1997 static void 1998 knote_dequeue(struct knote *kn) 1999 { 2000 struct kqueue *kq = kn->kn_kq; 2001 2002 KQ_OWNED(kn->kn_kq); 2003 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 2004 2005 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 2006 kn->kn_status &= ~KN_QUEUED; 2007 kq->kq_count--; 2008 } 2009 2010 static void 2011 knote_init(void) 2012 { 2013 2014 knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL, 2015 NULL, NULL, UMA_ALIGN_PTR, 0); 2016 } 2017 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL); 2018 2019 static struct knote * 2020 knote_alloc(int waitok) 2021 { 2022 return ((struct knote *)uma_zalloc(knote_zone, 2023 (waitok ? M_WAITOK : M_NOWAIT)|M_ZERO)); 2024 } 2025 2026 static void 2027 knote_free(struct knote *kn) 2028 { 2029 if (kn != NULL) 2030 uma_zfree(knote_zone, kn); 2031 } 2032 2033 /* 2034 * Register the kev w/ the kq specified by fd. 2035 */ 2036 int 2037 kqfd_register(int fd, struct kevent *kev, struct thread *td, int waitok) 2038 { 2039 struct kqueue *kq; 2040 struct file *fp; 2041 int error; 2042 2043 if ((error = fget(td, fd, &fp)) != 0) 2044 return (error); 2045 if ((error = kqueue_acquire(fp, &kq)) != 0) 2046 goto noacquire; 2047 2048 error = kqueue_register(kq, kev, td, waitok); 2049 2050 kqueue_release(kq, 0); 2051 2052 noacquire: 2053 fdrop(fp, td); 2054 2055 return error; 2056 }
Cache object: 9957aec882b81058d0bae5da063f7985
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