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