1 /* $NetBSD: kern_event.c,v 1.43 2007/12/05 17:19:57 pooka Exp $ */ 2 3 /*- 4 * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD: src/sys/kern/kern_event.c,v 1.27 2001/07/05 17:10:44 rwatson Exp $ 29 */ 30 31 #include <sys/cdefs.h> 32 __KERNEL_RCSID(0, "$NetBSD: kern_event.c,v 1.43 2007/12/05 17:19:57 pooka Exp $"); 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/kernel.h> 37 #include <sys/proc.h> 38 #include <sys/malloc.h> 39 #include <sys/unistd.h> 40 #include <sys/file.h> 41 #include <sys/fcntl.h> 42 #include <sys/select.h> 43 #include <sys/queue.h> 44 #include <sys/event.h> 45 #include <sys/eventvar.h> 46 #include <sys/poll.h> 47 #include <sys/pool.h> 48 #include <sys/protosw.h> 49 #include <sys/socket.h> 50 #include <sys/socketvar.h> 51 #include <sys/stat.h> 52 #include <sys/uio.h> 53 #include <sys/mount.h> 54 #include <sys/filedesc.h> 55 #include <sys/syscallargs.h> 56 #include <sys/kauth.h> 57 #include <sys/conf.h> 58 59 static void kqueue_wakeup(struct kqueue *kq); 60 61 static int kqueue_scan(struct file *, size_t, struct kevent *, 62 const struct timespec *, struct lwp *, register_t *, 63 const struct kevent_ops *); 64 static int kqueue_read(struct file *fp, off_t *offset, struct uio *uio, 65 kauth_cred_t cred, int flags); 66 static int kqueue_write(struct file *fp, off_t *offset, struct uio *uio, 67 kauth_cred_t cred, int flags); 68 static int kqueue_ioctl(struct file *fp, u_long com, void *data, 69 struct lwp *l); 70 static int kqueue_fcntl(struct file *fp, u_int com, void *data, 71 struct lwp *l); 72 static int kqueue_poll(struct file *fp, int events, struct lwp *l); 73 static int kqueue_kqfilter(struct file *fp, struct knote *kn); 74 static int kqueue_stat(struct file *fp, struct stat *sp, struct lwp *l); 75 static int kqueue_close(struct file *fp, struct lwp *l); 76 77 static const struct fileops kqueueops = { 78 kqueue_read, kqueue_write, kqueue_ioctl, kqueue_fcntl, kqueue_poll, 79 kqueue_stat, kqueue_close, kqueue_kqfilter 80 }; 81 82 static void knote_attach(struct knote *kn, struct filedesc *fdp); 83 static void knote_drop(struct knote *kn, struct lwp *l, 84 struct filedesc *fdp); 85 static void knote_enqueue(struct knote *kn); 86 static void knote_dequeue(struct knote *kn); 87 88 static void filt_kqdetach(struct knote *kn); 89 static int filt_kqueue(struct knote *kn, long hint); 90 static int filt_procattach(struct knote *kn); 91 static void filt_procdetach(struct knote *kn); 92 static int filt_proc(struct knote *kn, long hint); 93 static int filt_fileattach(struct knote *kn); 94 static void filt_timerexpire(void *knx); 95 static int filt_timerattach(struct knote *kn); 96 static void filt_timerdetach(struct knote *kn); 97 static int filt_timer(struct knote *kn, long hint); 98 99 static const struct filterops kqread_filtops = 100 { 1, NULL, filt_kqdetach, filt_kqueue }; 101 static const struct filterops proc_filtops = 102 { 0, filt_procattach, filt_procdetach, filt_proc }; 103 static const struct filterops file_filtops = 104 { 1, filt_fileattach, NULL, NULL }; 105 static const struct filterops timer_filtops = 106 { 0, filt_timerattach, filt_timerdetach, filt_timer }; 107 108 static POOL_INIT(kqueue_pool, sizeof(struct kqueue), 0, 0, 0, "kqueuepl", NULL, 109 IPL_VM); 110 static POOL_INIT(knote_pool, sizeof(struct knote), 0, 0, 0, "knotepl", NULL, 111 IPL_VM); 112 static int kq_ncallouts = 0; 113 static int kq_calloutmax = (4 * 1024); 114 115 MALLOC_DEFINE(M_KEVENT, "kevent", "kevents/knotes"); 116 117 #define KNOTE_ACTIVATE(kn) \ 118 do { \ 119 kn->kn_status |= KN_ACTIVE; \ 120 if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 121 knote_enqueue(kn); \ 122 } while(0) 123 124 #define KN_HASHSIZE 64 /* XXX should be tunable */ 125 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 126 127 extern const struct filterops sig_filtops; 128 129 /* 130 * Table for for all system-defined filters. 131 * These should be listed in the numeric order of the EVFILT_* defines. 132 * If filtops is NULL, the filter isn't implemented in NetBSD. 133 * End of list is when name is NULL. 134 */ 135 struct kfilter { 136 const char *name; /* name of filter */ 137 uint32_t filter; /* id of filter */ 138 const struct filterops *filtops;/* operations for filter */ 139 }; 140 141 /* System defined filters */ 142 static const struct kfilter sys_kfilters[] = { 143 { "EVFILT_READ", EVFILT_READ, &file_filtops }, 144 { "EVFILT_WRITE", EVFILT_WRITE, &file_filtops }, 145 { "EVFILT_AIO", EVFILT_AIO, NULL }, 146 { "EVFILT_VNODE", EVFILT_VNODE, &file_filtops }, 147 { "EVFILT_PROC", EVFILT_PROC, &proc_filtops }, 148 { "EVFILT_SIGNAL", EVFILT_SIGNAL, &sig_filtops }, 149 { "EVFILT_TIMER", EVFILT_TIMER, &timer_filtops }, 150 { NULL, 0, NULL }, /* end of list */ 151 }; 152 153 /* User defined kfilters */ 154 static struct kfilter *user_kfilters; /* array */ 155 static int user_kfilterc; /* current offset */ 156 static int user_kfiltermaxc; /* max size so far */ 157 158 /* 159 * Find kfilter entry by name, or NULL if not found. 160 */ 161 static const struct kfilter * 162 kfilter_byname_sys(const char *name) 163 { 164 int i; 165 166 for (i = 0; sys_kfilters[i].name != NULL; i++) { 167 if (strcmp(name, sys_kfilters[i].name) == 0) 168 return (&sys_kfilters[i]); 169 } 170 return (NULL); 171 } 172 173 static struct kfilter * 174 kfilter_byname_user(const char *name) 175 { 176 int i; 177 178 /* user filter slots have a NULL name if previously deregistered */ 179 for (i = 0; i < user_kfilterc ; i++) { 180 if (user_kfilters[i].name != NULL && 181 strcmp(name, user_kfilters[i].name) == 0) 182 return (&user_kfilters[i]); 183 } 184 return (NULL); 185 } 186 187 static const struct kfilter * 188 kfilter_byname(const char *name) 189 { 190 const struct kfilter *kfilter; 191 192 if ((kfilter = kfilter_byname_sys(name)) != NULL) 193 return (kfilter); 194 195 return (kfilter_byname_user(name)); 196 } 197 198 /* 199 * Find kfilter entry by filter id, or NULL if not found. 200 * Assumes entries are indexed in filter id order, for speed. 201 */ 202 static const struct kfilter * 203 kfilter_byfilter(uint32_t filter) 204 { 205 const struct kfilter *kfilter; 206 207 if (filter < EVFILT_SYSCOUNT) /* it's a system filter */ 208 kfilter = &sys_kfilters[filter]; 209 else if (user_kfilters != NULL && 210 filter < EVFILT_SYSCOUNT + user_kfilterc) 211 /* it's a user filter */ 212 kfilter = &user_kfilters[filter - EVFILT_SYSCOUNT]; 213 else 214 return (NULL); /* out of range */ 215 KASSERT(kfilter->filter == filter); /* sanity check! */ 216 return (kfilter); 217 } 218 219 /* 220 * Register a new kfilter. Stores the entry in user_kfilters. 221 * Returns 0 if operation succeeded, or an appropriate errno(2) otherwise. 222 * If retfilter != NULL, the new filterid is returned in it. 223 */ 224 int 225 kfilter_register(const char *name, const struct filterops *filtops, 226 int *retfilter) 227 { 228 struct kfilter *kfilter; 229 void *space; 230 int len; 231 int i; 232 233 if (name == NULL || name[0] == '\0' || filtops == NULL) 234 return (EINVAL); /* invalid args */ 235 if (kfilter_byname(name) != NULL) 236 return (EEXIST); /* already exists */ 237 if (user_kfilterc > 0xffffffff - EVFILT_SYSCOUNT) 238 return (EINVAL); /* too many */ 239 240 for (i = 0; i < user_kfilterc; i++) { 241 kfilter = &user_kfilters[i]; 242 if (kfilter->name == NULL) { 243 /* Previously deregistered slot. Reuse. */ 244 goto reuse; 245 } 246 } 247 248 /* check if need to grow user_kfilters */ 249 if (user_kfilterc + 1 > user_kfiltermaxc) { 250 /* 251 * Grow in KFILTER_EXTENT chunks. Use malloc(9), because we 252 * want to traverse user_kfilters as an array. 253 */ 254 user_kfiltermaxc += KFILTER_EXTENT; 255 kfilter = malloc(user_kfiltermaxc * sizeof(struct filter *), 256 M_KEVENT, M_WAITOK); 257 258 /* copy existing user_kfilters */ 259 if (user_kfilters != NULL) 260 memcpy((void *)kfilter, (void *)user_kfilters, 261 user_kfilterc * sizeof(struct kfilter *)); 262 /* zero new sections */ 263 memset((char *)kfilter + 264 user_kfilterc * sizeof(struct kfilter *), 0, 265 (user_kfiltermaxc - user_kfilterc) * 266 sizeof(struct kfilter *)); 267 /* switch to new kfilter */ 268 if (user_kfilters != NULL) 269 free(user_kfilters, M_KEVENT); 270 user_kfilters = kfilter; 271 } 272 /* Adding new slot */ 273 kfilter = &user_kfilters[user_kfilterc++]; 274 reuse: 275 len = strlen(name) + 1; /* copy name */ 276 space = malloc(len, M_KEVENT, M_WAITOK); 277 memcpy(space, name, len); 278 kfilter->name = space; 279 280 kfilter->filter = (kfilter - user_kfilters) + EVFILT_SYSCOUNT; 281 282 len = sizeof(struct filterops); /* copy filtops */ 283 space = malloc(len, M_KEVENT, M_WAITOK); 284 memcpy(space, filtops, len); 285 kfilter->filtops = space; 286 287 if (retfilter != NULL) 288 *retfilter = kfilter->filter; 289 return (0); 290 } 291 292 /* 293 * Unregister a kfilter previously registered with kfilter_register. 294 * This retains the filter id, but clears the name and frees filtops (filter 295 * operations), so that the number isn't reused during a boot. 296 * Returns 0 if operation succeeded, or an appropriate errno(2) otherwise. 297 */ 298 int 299 kfilter_unregister(const char *name) 300 { 301 struct kfilter *kfilter; 302 303 if (name == NULL || name[0] == '\0') 304 return (EINVAL); /* invalid name */ 305 306 if (kfilter_byname_sys(name) != NULL) 307 return (EINVAL); /* can't detach system filters */ 308 309 kfilter = kfilter_byname_user(name); 310 if (kfilter == NULL) /* not found */ 311 return (ENOENT); 312 313 /* XXXUNCONST Cast away const (but we know it's safe. */ 314 free(__UNCONST(kfilter->name), M_KEVENT); 315 kfilter->name = NULL; /* mark as `not implemented' */ 316 317 if (kfilter->filtops != NULL) { 318 /* XXXUNCONST Cast away const (but we know it's safe. */ 319 free(__UNCONST(kfilter->filtops), M_KEVENT); 320 kfilter->filtops = NULL; /* mark as `not implemented' */ 321 } 322 return (0); 323 } 324 325 326 /* 327 * Filter attach method for EVFILT_READ and EVFILT_WRITE on normal file 328 * descriptors. Calls struct fileops kqfilter method for given file descriptor. 329 */ 330 static int 331 filt_fileattach(struct knote *kn) 332 { 333 struct file *fp; 334 335 fp = kn->kn_fp; 336 return ((*fp->f_ops->fo_kqfilter)(fp, kn)); 337 } 338 339 /* 340 * Filter detach method for EVFILT_READ on kqueue descriptor. 341 */ 342 static void 343 filt_kqdetach(struct knote *kn) 344 { 345 struct kqueue *kq; 346 347 kq = (struct kqueue *)kn->kn_fp->f_data; 348 SLIST_REMOVE(&kq->kq_sel.sel_klist, kn, knote, kn_selnext); 349 } 350 351 /* 352 * Filter event method for EVFILT_READ on kqueue descriptor. 353 */ 354 /*ARGSUSED*/ 355 static int 356 filt_kqueue(struct knote *kn, long hint) 357 { 358 struct kqueue *kq; 359 360 kq = (struct kqueue *)kn->kn_fp->f_data; 361 kn->kn_data = kq->kq_count; 362 return (kn->kn_data > 0); 363 } 364 365 /* 366 * Filter attach method for EVFILT_PROC. 367 */ 368 static int 369 filt_procattach(struct knote *kn) 370 { 371 struct proc *p, *curp; 372 struct lwp *curl; 373 374 curl = curlwp; 375 curp = curl->l_proc; 376 377 p = pfind(kn->kn_id); 378 if (p == NULL) 379 return (ESRCH); 380 381 /* 382 * Fail if it's not owned by you, or the last exec gave us 383 * setuid/setgid privs (unless you're root). 384 */ 385 if ((kauth_cred_getuid(p->p_cred) != kauth_cred_getuid(curl->l_cred) || 386 (p->p_flag & PK_SUGID)) && kauth_authorize_generic(curl->l_cred, 387 KAUTH_GENERIC_ISSUSER, NULL) != 0) 388 return (EACCES); 389 390 kn->kn_ptr.p_proc = p; 391 kn->kn_flags |= EV_CLEAR; /* automatically set */ 392 393 /* 394 * internal flag indicating registration done by kernel 395 */ 396 if (kn->kn_flags & EV_FLAG1) { 397 kn->kn_data = kn->kn_sdata; /* ppid */ 398 kn->kn_fflags = NOTE_CHILD; 399 kn->kn_flags &= ~EV_FLAG1; 400 } 401 402 /* XXXSMP lock the process? */ 403 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 404 405 return (0); 406 } 407 408 /* 409 * Filter detach method for EVFILT_PROC. 410 * 411 * The knote may be attached to a different process, which may exit, 412 * leaving nothing for the knote to be attached to. So when the process 413 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 414 * it will be deleted when read out. However, as part of the knote deletion, 415 * this routine is called, so a check is needed to avoid actually performing 416 * a detach, because the original process might not exist any more. 417 */ 418 static void 419 filt_procdetach(struct knote *kn) 420 { 421 struct proc *p; 422 423 if (kn->kn_status & KN_DETACHED) 424 return; 425 426 p = kn->kn_ptr.p_proc; 427 428 /* XXXSMP lock the process? */ 429 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 430 } 431 432 /* 433 * Filter event method for EVFILT_PROC. 434 */ 435 static int 436 filt_proc(struct knote *kn, long hint) 437 { 438 u_int event; 439 440 /* 441 * mask off extra data 442 */ 443 event = (u_int)hint & NOTE_PCTRLMASK; 444 445 /* 446 * if the user is interested in this event, record it. 447 */ 448 if (kn->kn_sfflags & event) 449 kn->kn_fflags |= event; 450 451 /* 452 * process is gone, so flag the event as finished. 453 */ 454 if (event == NOTE_EXIT) { 455 /* 456 * Detach the knote from watched process and mark 457 * it as such. We can't leave this to kqueue_scan(), 458 * since the process might not exist by then. And we 459 * have to do this now, since psignal KNOTE() is called 460 * also for zombies and we might end up reading freed 461 * memory if the kevent would already be picked up 462 * and knote g/c'ed. 463 */ 464 kn->kn_fop->f_detach(kn); 465 kn->kn_status |= KN_DETACHED; 466 467 /* Mark as ONESHOT, so that the knote it g/c'ed when read */ 468 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 469 return (1); 470 } 471 472 /* 473 * process forked, and user wants to track the new process, 474 * so attach a new knote to it, and immediately report an 475 * event with the parent's pid. 476 */ 477 if ((event == NOTE_FORK) && (kn->kn_sfflags & NOTE_TRACK)) { 478 struct kevent kev; 479 int error; 480 481 /* 482 * register knote with new process. 483 */ 484 kev.ident = hint & NOTE_PDATAMASK; /* pid */ 485 kev.filter = kn->kn_filter; 486 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 487 kev.fflags = kn->kn_sfflags; 488 kev.data = kn->kn_id; /* parent */ 489 kev.udata = kn->kn_kevent.udata; /* preserve udata */ 490 error = kqueue_register(kn->kn_kq, &kev, NULL); 491 if (error) 492 kn->kn_fflags |= NOTE_TRACKERR; 493 } 494 495 return (kn->kn_fflags != 0); 496 } 497 498 static void 499 filt_timerexpire(void *knx) 500 { 501 struct knote *kn = knx; 502 int tticks; 503 504 kn->kn_data++; 505 KNOTE_ACTIVATE(kn); 506 507 if ((kn->kn_flags & EV_ONESHOT) == 0) { 508 tticks = mstohz(kn->kn_sdata); 509 callout_schedule((callout_t *)kn->kn_hook, tticks); 510 } 511 } 512 513 /* 514 * data contains amount of time to sleep, in milliseconds 515 */ 516 static int 517 filt_timerattach(struct knote *kn) 518 { 519 callout_t *calloutp; 520 int tticks; 521 522 if (kq_ncallouts >= kq_calloutmax) 523 return (ENOMEM); 524 kq_ncallouts++; 525 526 tticks = mstohz(kn->kn_sdata); 527 528 /* if the supplied value is under our resolution, use 1 tick */ 529 if (tticks == 0) { 530 if (kn->kn_sdata == 0) 531 return (EINVAL); 532 tticks = 1; 533 } 534 535 kn->kn_flags |= EV_CLEAR; /* automatically set */ 536 MALLOC(calloutp, callout_t *, sizeof(*calloutp), 537 M_KEVENT, 0); 538 callout_init(calloutp, 0); 539 callout_reset(calloutp, tticks, filt_timerexpire, kn); 540 kn->kn_hook = calloutp; 541 542 return (0); 543 } 544 545 static void 546 filt_timerdetach(struct knote *kn) 547 { 548 callout_t *calloutp; 549 550 calloutp = (callout_t *)kn->kn_hook; 551 callout_stop(calloutp); 552 callout_destroy(calloutp); 553 FREE(calloutp, M_KEVENT); 554 kq_ncallouts--; 555 } 556 557 static int 558 filt_timer(struct knote *kn, long hint) 559 { 560 return (kn->kn_data != 0); 561 } 562 563 /* 564 * filt_seltrue: 565 * 566 * This filter "event" routine simulates seltrue(). 567 */ 568 int 569 filt_seltrue(struct knote *kn, long hint) 570 { 571 572 /* 573 * We don't know how much data can be read/written, 574 * but we know that it *can* be. This is about as 575 * good as select/poll does as well. 576 */ 577 kn->kn_data = 0; 578 return (1); 579 } 580 581 /* 582 * This provides full kqfilter entry for device switch tables, which 583 * has same effect as filter using filt_seltrue() as filter method. 584 */ 585 static void 586 filt_seltruedetach(struct knote *kn) 587 { 588 /* Nothing to do */ 589 } 590 591 const struct filterops seltrue_filtops = 592 { 1, NULL, filt_seltruedetach, filt_seltrue }; 593 594 int 595 seltrue_kqfilter(dev_t dev, struct knote *kn) 596 { 597 switch (kn->kn_filter) { 598 case EVFILT_READ: 599 case EVFILT_WRITE: 600 kn->kn_fop = &seltrue_filtops; 601 break; 602 default: 603 return (EINVAL); 604 } 605 606 /* Nothing more to do */ 607 return (0); 608 } 609 610 /* 611 * kqueue(2) system call. 612 */ 613 int 614 sys_kqueue(struct lwp *l, void *v, register_t *retval) 615 { 616 struct filedesc *fdp; 617 struct kqueue *kq; 618 struct file *fp; 619 int fd, error; 620 621 fdp = l->l_proc->p_fd; 622 error = falloc(l, &fp, &fd); /* setup a new file descriptor */ 623 if (error) 624 return (error); 625 fp->f_flag = FREAD | FWRITE; 626 fp->f_type = DTYPE_KQUEUE; 627 fp->f_ops = &kqueueops; 628 kq = pool_get(&kqueue_pool, PR_WAITOK); 629 memset((char *)kq, 0, sizeof(struct kqueue)); 630 simple_lock_init(&kq->kq_lock); 631 TAILQ_INIT(&kq->kq_head); 632 fp->f_data = (void *)kq; /* store the kqueue with the fp */ 633 *retval = fd; 634 if (fdp->fd_knlistsize < 0) 635 fdp->fd_knlistsize = 0; /* this process has a kq */ 636 kq->kq_fdp = fdp; 637 FILE_SET_MATURE(fp); 638 FILE_UNUSE(fp, l); /* falloc() does FILE_USE() */ 639 return (error); 640 } 641 642 /* 643 * kevent(2) system call. 644 */ 645 static int 646 kevent_fetch_changes(void *private, const struct kevent *changelist, 647 struct kevent *changes, size_t index, int n) 648 { 649 return copyin(changelist + index, changes, n * sizeof(*changes)); 650 } 651 652 static int 653 kevent_put_events(void *private, struct kevent *events, 654 struct kevent *eventlist, size_t index, int n) 655 { 656 return copyout(events, eventlist + index, n * sizeof(*events)); 657 } 658 659 static const struct kevent_ops kevent_native_ops = { 660 keo_private: NULL, 661 keo_fetch_timeout: copyin, 662 keo_fetch_changes: kevent_fetch_changes, 663 keo_put_events: kevent_put_events, 664 }; 665 666 int 667 sys_kevent(struct lwp *l, void *v, register_t *retval) 668 { 669 struct sys_kevent_args /* { 670 syscallarg(int) fd; 671 syscallarg(const struct kevent *) changelist; 672 syscallarg(size_t) nchanges; 673 syscallarg(struct kevent *) eventlist; 674 syscallarg(size_t) nevents; 675 syscallarg(const struct timespec *) timeout; 676 } */ *uap = v; 677 678 return kevent1(l, retval, SCARG(uap, fd), SCARG(uap, changelist), 679 SCARG(uap, nchanges), SCARG(uap, eventlist), SCARG(uap, nevents), 680 SCARG(uap, timeout), &kevent_native_ops); 681 } 682 683 int 684 kevent1(struct lwp *l, register_t *retval, int fd, 685 const struct kevent *changelist, size_t nchanges, struct kevent *eventlist, 686 size_t nevents, const struct timespec *timeout, 687 const struct kevent_ops *keops) 688 { 689 struct kevent *kevp; 690 struct kqueue *kq; 691 struct file *fp; 692 struct timespec ts; 693 struct proc *p; 694 size_t i, n, ichange; 695 int nerrors, error; 696 697 p = l->l_proc; 698 /* check that we're dealing with a kq */ 699 fp = fd_getfile(p->p_fd, fd); 700 if (fp == NULL) 701 return (EBADF); 702 703 if (fp->f_type != DTYPE_KQUEUE) { 704 mutex_exit(&fp->f_lock); 705 return (EBADF); 706 } 707 708 FILE_USE(fp); 709 710 if (timeout != NULL) { 711 error = (*keops->keo_fetch_timeout)(timeout, &ts, sizeof(ts)); 712 if (error) 713 goto done; 714 timeout = &ts; 715 } 716 717 kq = (struct kqueue *)fp->f_data; 718 nerrors = 0; 719 ichange = 0; 720 721 /* traverse list of events to register */ 722 while (nchanges > 0) { 723 /* copyin a maximum of KQ_EVENTS at each pass */ 724 n = MIN(nchanges, KQ_NEVENTS); 725 error = (*keops->keo_fetch_changes)(keops->keo_private, 726 changelist, kq->kq_kev, ichange, n); 727 if (error) 728 goto done; 729 for (i = 0; i < n; i++) { 730 kevp = &kq->kq_kev[i]; 731 kevp->flags &= ~EV_SYSFLAGS; 732 /* register each knote */ 733 error = kqueue_register(kq, kevp, l); 734 if (error) { 735 if (nevents != 0) { 736 kevp->flags = EV_ERROR; 737 kevp->data = error; 738 error = (*keops->keo_put_events) 739 (keops->keo_private, kevp, 740 eventlist, nerrors, 1); 741 if (error) 742 goto done; 743 nevents--; 744 nerrors++; 745 } else { 746 goto done; 747 } 748 } 749 } 750 nchanges -= n; /* update the results */ 751 ichange += n; 752 } 753 if (nerrors) { 754 *retval = nerrors; 755 error = 0; 756 goto done; 757 } 758 759 /* actually scan through the events */ 760 error = kqueue_scan(fp, nevents, eventlist, timeout, l, retval, keops); 761 done: 762 FILE_UNUSE(fp, l); 763 return (error); 764 } 765 766 /* 767 * Register a given kevent kev onto the kqueue 768 */ 769 int 770 kqueue_register(struct kqueue *kq, struct kevent *kev, struct lwp *l) 771 { 772 const struct kfilter *kfilter; 773 struct filedesc *fdp; 774 struct file *fp; 775 struct knote *kn; 776 int s, error; 777 778 fdp = kq->kq_fdp; 779 fp = NULL; 780 kn = NULL; 781 error = 0; 782 kfilter = kfilter_byfilter(kev->filter); 783 if (kfilter == NULL || kfilter->filtops == NULL) { 784 /* filter not found nor implemented */ 785 return (EINVAL); 786 } 787 788 /* search if knote already exists */ 789 if (kfilter->filtops->f_isfd) { 790 /* monitoring a file descriptor */ 791 if ((fp = fd_getfile(fdp, kev->ident)) == NULL) 792 return (EBADF); /* validate descriptor */ 793 FILE_USE(fp); 794 795 if (kev->ident < fdp->fd_knlistsize) { 796 SLIST_FOREACH(kn, &fdp->fd_knlist[kev->ident], kn_link) 797 if (kq == kn->kn_kq && 798 kev->filter == kn->kn_filter) 799 break; 800 } 801 } else { 802 /* 803 * not monitoring a file descriptor, so 804 * lookup knotes in internal hash table 805 */ 806 if (fdp->fd_knhashmask != 0) { 807 struct klist *list; 808 809 list = &fdp->fd_knhash[ 810 KN_HASH((u_long)kev->ident, fdp->fd_knhashmask)]; 811 SLIST_FOREACH(kn, list, kn_link) 812 if (kev->ident == kn->kn_id && 813 kq == kn->kn_kq && 814 kev->filter == kn->kn_filter) 815 break; 816 } 817 } 818 819 if (kn == NULL && ((kev->flags & EV_ADD) == 0)) { 820 error = ENOENT; /* filter not found */ 821 goto done; 822 } 823 824 /* 825 * kn now contains the matching knote, or NULL if no match 826 */ 827 if (kev->flags & EV_ADD) { 828 /* add knote */ 829 830 if (kn == NULL) { 831 /* create new knote */ 832 kn = pool_get(&knote_pool, PR_WAITOK); 833 if (kn == NULL) { 834 error = ENOMEM; 835 goto done; 836 } 837 kn->kn_fp = fp; 838 kn->kn_kq = kq; 839 kn->kn_fop = kfilter->filtops; 840 841 /* 842 * apply reference count to knote structure, and 843 * do not release it at the end of this routine. 844 */ 845 fp = NULL; 846 847 kn->kn_sfflags = kev->fflags; 848 kn->kn_sdata = kev->data; 849 kev->fflags = 0; 850 kev->data = 0; 851 kn->kn_kevent = *kev; 852 853 knote_attach(kn, fdp); 854 if ((error = kfilter->filtops->f_attach(kn)) != 0) { 855 knote_drop(kn, l, fdp); 856 goto done; 857 } 858 } else { 859 /* modify existing knote */ 860 861 /* 862 * The user may change some filter values after the 863 * initial EV_ADD, but doing so will not reset any 864 * filter which have already been triggered. 865 */ 866 kn->kn_sfflags = kev->fflags; 867 kn->kn_sdata = kev->data; 868 kn->kn_kevent.udata = kev->udata; 869 } 870 871 s = splsched(); 872 if (kn->kn_fop->f_event(kn, 0)) 873 KNOTE_ACTIVATE(kn); 874 splx(s); 875 876 } else if (kev->flags & EV_DELETE) { /* delete knote */ 877 kn->kn_fop->f_detach(kn); 878 knote_drop(kn, l, fdp); 879 goto done; 880 } 881 882 /* disable knote */ 883 if ((kev->flags & EV_DISABLE) && 884 ((kn->kn_status & KN_DISABLED) == 0)) { 885 s = splsched(); 886 kn->kn_status |= KN_DISABLED; 887 splx(s); 888 } 889 890 /* enable knote */ 891 if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) { 892 s = splsched(); 893 kn->kn_status &= ~KN_DISABLED; 894 if ((kn->kn_status & KN_ACTIVE) && 895 ((kn->kn_status & KN_QUEUED) == 0)) 896 knote_enqueue(kn); 897 splx(s); 898 } 899 900 done: 901 if (fp != NULL) 902 FILE_UNUSE(fp, l); 903 return (error); 904 } 905 906 /* 907 * Scan through the list of events on fp (for a maximum of maxevents), 908 * returning the results in to ulistp. Timeout is determined by tsp; if 909 * NULL, wait indefinitely, if 0 valued, perform a poll, otherwise wait 910 * as appropriate. 911 */ 912 static int 913 kqueue_scan(struct file *fp, size_t maxevents, struct kevent *ulistp, 914 const struct timespec *tsp, struct lwp *l, register_t *retval, 915 const struct kevent_ops *keops) 916 { 917 struct proc *p = l->l_proc; 918 struct kqueue *kq; 919 struct kevent *kevp; 920 struct timeval atv, sleeptv; 921 struct knote *kn, *marker=NULL; 922 size_t count, nkev, nevents; 923 int s, timeout, error; 924 925 kq = (struct kqueue *)fp->f_data; 926 count = maxevents; 927 nkev = nevents = error = 0; 928 if (count == 0) 929 goto done; 930 931 if (tsp) { /* timeout supplied */ 932 TIMESPEC_TO_TIMEVAL(&atv, tsp); 933 if (inittimeleft(&atv, &sleeptv) == -1) { 934 error = EINVAL; 935 goto done; 936 } 937 timeout = tvtohz(&atv); 938 if (timeout <= 0) 939 timeout = -1; /* do poll */ 940 } else { 941 /* no timeout, wait forever */ 942 timeout = 0; 943 } 944 945 MALLOC(marker, struct knote *, sizeof(*marker), M_KEVENT, M_WAITOK); 946 memset(marker, 0, sizeof(*marker)); 947 948 goto start; 949 950 retry: 951 if (tsp && (timeout = gettimeleft(&atv, &sleeptv)) <= 0) { 952 goto done; 953 } 954 955 start: 956 kevp = kq->kq_kev; 957 s = splsched(); 958 simple_lock(&kq->kq_lock); 959 if (kq->kq_count == 0) { 960 if (timeout < 0) { 961 error = EWOULDBLOCK; 962 simple_unlock(&kq->kq_lock); 963 } else { 964 kq->kq_state |= KQ_SLEEP; 965 error = ltsleep(kq, PSOCK | PCATCH | PNORELOCK, 966 "kqread", timeout, &kq->kq_lock); 967 } 968 splx(s); 969 if (error == 0) 970 goto retry; 971 /* don't restart after signals... */ 972 if (error == ERESTART) 973 error = EINTR; 974 else if (error == EWOULDBLOCK) 975 error = 0; 976 goto done; 977 } 978 979 /* mark end of knote list */ 980 TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); 981 simple_unlock(&kq->kq_lock); 982 983 while (count) { /* while user wants data ... */ 984 simple_lock(&kq->kq_lock); 985 kn = TAILQ_FIRST(&kq->kq_head); /* get next knote */ 986 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 987 if (kn == marker) { /* if it's our marker, stop */ 988 /* What if it's some else's marker? */ 989 simple_unlock(&kq->kq_lock); 990 splx(s); 991 if (count == maxevents) 992 goto retry; 993 goto done; 994 } 995 kq->kq_count--; 996 simple_unlock(&kq->kq_lock); 997 998 if (kn->kn_status & KN_DISABLED) { 999 /* don't want disabled events */ 1000 kn->kn_status &= ~KN_QUEUED; 1001 continue; 1002 } 1003 if ((kn->kn_flags & EV_ONESHOT) == 0 && 1004 kn->kn_fop->f_event(kn, 0) == 0) { 1005 /* 1006 * non-ONESHOT event that hasn't 1007 * triggered again, so de-queue. 1008 */ 1009 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 1010 continue; 1011 } 1012 *kevp = kn->kn_kevent; 1013 kevp++; 1014 nkev++; 1015 if (kn->kn_flags & EV_ONESHOT) { 1016 /* delete ONESHOT events after retrieval */ 1017 kn->kn_status &= ~KN_QUEUED; 1018 splx(s); 1019 kn->kn_fop->f_detach(kn); 1020 knote_drop(kn, l, p->p_fd); 1021 s = splsched(); 1022 } else if (kn->kn_flags & EV_CLEAR) { 1023 /* clear state after retrieval */ 1024 kn->kn_data = 0; 1025 kn->kn_fflags = 0; 1026 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 1027 } else { 1028 /* add event back on list */ 1029 simple_lock(&kq->kq_lock); 1030 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 1031 kq->kq_count++; 1032 simple_unlock(&kq->kq_lock); 1033 } 1034 count--; 1035 if (nkev == KQ_NEVENTS) { 1036 /* do copyouts in KQ_NEVENTS chunks */ 1037 splx(s); 1038 error = (*keops->keo_put_events)(keops->keo_private, 1039 &kq->kq_kev[0], ulistp, nevents, nkev); 1040 nevents += nkev; 1041 nkev = 0; 1042 kevp = kq->kq_kev; 1043 s = splsched(); 1044 if (error) 1045 break; 1046 } 1047 } 1048 1049 /* remove marker */ 1050 simple_lock(&kq->kq_lock); 1051 TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); 1052 simple_unlock(&kq->kq_lock); 1053 splx(s); 1054 done: 1055 if (marker) 1056 FREE(marker, M_KEVENT); 1057 1058 if (nkev != 0) 1059 /* copyout remaining events */ 1060 error = (*keops->keo_put_events)(keops->keo_private, 1061 &kq->kq_kev[0], ulistp, nevents, nkev); 1062 *retval = maxevents - count; 1063 1064 return (error); 1065 } 1066 1067 /* 1068 * struct fileops read method for a kqueue descriptor. 1069 * Not implemented. 1070 * XXX: This could be expanded to call kqueue_scan, if desired. 1071 */ 1072 /*ARGSUSED*/ 1073 static int 1074 kqueue_read(struct file *fp, off_t *offset, struct uio *uio, kauth_cred_t cred, 1075 int flags) 1076 { 1077 1078 return (ENXIO); 1079 } 1080 1081 /* 1082 * struct fileops write method for a kqueue descriptor. 1083 * Not implemented. 1084 */ 1085 /*ARGSUSED*/ 1086 static int 1087 kqueue_write(struct file *fp, off_t *offset, struct uio *uio, kauth_cred_t cred, 1088 int flags) 1089 { 1090 1091 return (ENXIO); 1092 } 1093 1094 /* 1095 * struct fileops ioctl method for a kqueue descriptor. 1096 * 1097 * Two ioctls are currently supported. They both use struct kfilter_mapping: 1098 * KFILTER_BYNAME find name for filter, and return result in 1099 * name, which is of size len. 1100 * KFILTER_BYFILTER find filter for name. len is ignored. 1101 */ 1102 /*ARGSUSED*/ 1103 static int 1104 kqueue_ioctl(struct file *fp, u_long com, void *data, struct lwp *l) 1105 { 1106 struct kfilter_mapping *km; 1107 const struct kfilter *kfilter; 1108 char *name; 1109 int error; 1110 1111 km = (struct kfilter_mapping *)data; 1112 error = 0; 1113 1114 switch (com) { 1115 case KFILTER_BYFILTER: /* convert filter -> name */ 1116 kfilter = kfilter_byfilter(km->filter); 1117 if (kfilter != NULL) 1118 error = copyoutstr(kfilter->name, km->name, km->len, 1119 NULL); 1120 else 1121 error = ENOENT; 1122 break; 1123 1124 case KFILTER_BYNAME: /* convert name -> filter */ 1125 MALLOC(name, char *, KFILTER_MAXNAME, M_KEVENT, M_WAITOK); 1126 error = copyinstr(km->name, name, KFILTER_MAXNAME, NULL); 1127 if (error) { 1128 FREE(name, M_KEVENT); 1129 break; 1130 } 1131 kfilter = kfilter_byname(name); 1132 if (kfilter != NULL) 1133 km->filter = kfilter->filter; 1134 else 1135 error = ENOENT; 1136 FREE(name, M_KEVENT); 1137 break; 1138 1139 default: 1140 error = ENOTTY; 1141 1142 } 1143 return (error); 1144 } 1145 1146 /* 1147 * struct fileops fcntl method for a kqueue descriptor. 1148 * Not implemented. 1149 */ 1150 /*ARGSUSED*/ 1151 static int 1152 kqueue_fcntl(struct file *fp, u_int com, void *data, struct lwp *l) 1153 { 1154 1155 return (ENOTTY); 1156 } 1157 1158 /* 1159 * struct fileops poll method for a kqueue descriptor. 1160 * Determine if kqueue has events pending. 1161 */ 1162 static int 1163 kqueue_poll(struct file *fp, int events, struct lwp *l) 1164 { 1165 struct kqueue *kq; 1166 int revents; 1167 1168 kq = (struct kqueue *)fp->f_data; 1169 revents = 0; 1170 if (events & (POLLIN | POLLRDNORM)) { 1171 if (kq->kq_count) { 1172 revents |= events & (POLLIN | POLLRDNORM); 1173 } else { 1174 selrecord(l, &kq->kq_sel); 1175 } 1176 } 1177 return (revents); 1178 } 1179 1180 /* 1181 * struct fileops stat method for a kqueue descriptor. 1182 * Returns dummy info, with st_size being number of events pending. 1183 */ 1184 static int 1185 kqueue_stat(struct file *fp, struct stat *st, struct lwp *l) 1186 { 1187 struct kqueue *kq; 1188 1189 kq = (struct kqueue *)fp->f_data; 1190 memset((void *)st, 0, sizeof(*st)); 1191 st->st_size = kq->kq_count; 1192 st->st_blksize = sizeof(struct kevent); 1193 st->st_mode = S_IFIFO; 1194 return (0); 1195 } 1196 1197 /* 1198 * struct fileops close method for a kqueue descriptor. 1199 * Cleans up kqueue. 1200 */ 1201 static int 1202 kqueue_close(struct file *fp, struct lwp *l) 1203 { 1204 struct proc *p = l->l_proc; 1205 struct kqueue *kq; 1206 struct filedesc *fdp; 1207 struct knote **knp, *kn, *kn0; 1208 int i; 1209 1210 kq = (struct kqueue *)fp->f_data; 1211 fdp = p->p_fd; 1212 for (i = 0; i < fdp->fd_knlistsize; i++) { 1213 knp = &SLIST_FIRST(&fdp->fd_knlist[i]); 1214 kn = *knp; 1215 while (kn != NULL) { 1216 kn0 = SLIST_NEXT(kn, kn_link); 1217 if (kq == kn->kn_kq) { 1218 kn->kn_fop->f_detach(kn); 1219 FILE_UNUSE(kn->kn_fp, l); 1220 pool_put(&knote_pool, kn); 1221 *knp = kn0; 1222 } else { 1223 knp = &SLIST_NEXT(kn, kn_link); 1224 } 1225 kn = kn0; 1226 } 1227 } 1228 if (fdp->fd_knhashmask != 0) { 1229 for (i = 0; i < fdp->fd_knhashmask + 1; i++) { 1230 knp = &SLIST_FIRST(&fdp->fd_knhash[i]); 1231 kn = *knp; 1232 while (kn != NULL) { 1233 kn0 = SLIST_NEXT(kn, kn_link); 1234 if (kq == kn->kn_kq) { 1235 kn->kn_fop->f_detach(kn); 1236 /* XXX non-fd release of kn->kn_ptr */ 1237 pool_put(&knote_pool, kn); 1238 *knp = kn0; 1239 } else { 1240 knp = &SLIST_NEXT(kn, kn_link); 1241 } 1242 kn = kn0; 1243 } 1244 } 1245 } 1246 pool_put(&kqueue_pool, kq); 1247 fp->f_data = NULL; 1248 1249 return (0); 1250 } 1251 1252 /* 1253 * wakeup a kqueue 1254 */ 1255 static void 1256 kqueue_wakeup(struct kqueue *kq) 1257 { 1258 int s; 1259 1260 s = splsched(); 1261 simple_lock(&kq->kq_lock); 1262 if (kq->kq_state & KQ_SLEEP) { /* if currently sleeping ... */ 1263 kq->kq_state &= ~KQ_SLEEP; 1264 wakeup(kq); /* ... wakeup */ 1265 } 1266 1267 /* Notify select/poll and kevent. */ 1268 selnotify(&kq->kq_sel, 0); 1269 simple_unlock(&kq->kq_lock); 1270 splx(s); 1271 } 1272 1273 /* 1274 * struct fileops kqfilter method for a kqueue descriptor. 1275 * Event triggered when monitored kqueue changes. 1276 */ 1277 /*ARGSUSED*/ 1278 static int 1279 kqueue_kqfilter(struct file *fp, struct knote *kn) 1280 { 1281 struct kqueue *kq; 1282 1283 KASSERT(fp == kn->kn_fp); 1284 kq = (struct kqueue *)kn->kn_fp->f_data; 1285 if (kn->kn_filter != EVFILT_READ) 1286 return (1); 1287 kn->kn_fop = &kqread_filtops; 1288 SLIST_INSERT_HEAD(&kq->kq_sel.sel_klist, kn, kn_selnext); 1289 return (0); 1290 } 1291 1292 1293 /* 1294 * Walk down a list of knotes, activating them if their event has triggered. 1295 */ 1296 void 1297 knote(struct klist *list, long hint) 1298 { 1299 struct knote *kn; 1300 1301 SLIST_FOREACH(kn, list, kn_selnext) 1302 if (kn->kn_fop->f_event(kn, hint)) 1303 KNOTE_ACTIVATE(kn); 1304 } 1305 1306 /* 1307 * Remove all knotes from a specified klist 1308 */ 1309 void 1310 knote_remove(struct lwp *l, struct klist *list) 1311 { 1312 struct knote *kn; 1313 1314 while ((kn = SLIST_FIRST(list)) != NULL) { 1315 kn->kn_fop->f_detach(kn); 1316 knote_drop(kn, l, l->l_proc->p_fd); 1317 } 1318 } 1319 1320 /* 1321 * Remove all knotes referencing a specified fd 1322 */ 1323 void 1324 knote_fdclose(struct lwp *l, int fd) 1325 { 1326 struct filedesc *fdp; 1327 struct klist *list; 1328 1329 fdp = l->l_proc->p_fd; 1330 list = &fdp->fd_knlist[fd]; 1331 knote_remove(l, list); 1332 } 1333 1334 /* 1335 * Attach a new knote to a file descriptor 1336 */ 1337 static void 1338 knote_attach(struct knote *kn, struct filedesc *fdp) 1339 { 1340 struct klist *list; 1341 int size; 1342 1343 if (! kn->kn_fop->f_isfd) { 1344 /* if knote is not on an fd, store on internal hash table */ 1345 if (fdp->fd_knhashmask == 0) 1346 fdp->fd_knhash = hashinit(KN_HASHSIZE, HASH_LIST, 1347 M_KEVENT, M_WAITOK, &fdp->fd_knhashmask); 1348 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; 1349 goto done; 1350 } 1351 1352 /* 1353 * otherwise, knote is on an fd. 1354 * knotes are stored in fd_knlist indexed by kn->kn_id. 1355 */ 1356 if (fdp->fd_knlistsize <= kn->kn_id) { 1357 /* expand list, it's too small */ 1358 size = fdp->fd_knlistsize; 1359 while (size <= kn->kn_id) { 1360 /* grow in KQ_EXTENT chunks */ 1361 size += KQ_EXTENT; 1362 } 1363 list = malloc(size * sizeof(struct klist *), M_KEVENT,M_WAITOK); 1364 if (fdp->fd_knlist) { 1365 /* copy existing knlist */ 1366 memcpy((void *)list, (void *)fdp->fd_knlist, 1367 fdp->fd_knlistsize * sizeof(struct klist *)); 1368 } 1369 /* 1370 * Zero new memory. Stylistically, SLIST_INIT() should be 1371 * used here, but that does same thing as the memset() anyway. 1372 */ 1373 memset(&list[fdp->fd_knlistsize], 0, 1374 (size - fdp->fd_knlistsize) * sizeof(struct klist *)); 1375 1376 /* switch to new knlist */ 1377 if (fdp->fd_knlist != NULL) 1378 free(fdp->fd_knlist, M_KEVENT); 1379 fdp->fd_knlistsize = size; 1380 fdp->fd_knlist = list; 1381 } 1382 1383 /* get list head for this fd */ 1384 list = &fdp->fd_knlist[kn->kn_id]; 1385 done: 1386 /* add new knote */ 1387 SLIST_INSERT_HEAD(list, kn, kn_link); 1388 kn->kn_status = 0; 1389 } 1390 1391 /* 1392 * Drop knote. 1393 * Should be called at spl == 0, since we don't want to hold spl 1394 * while calling FILE_UNUSE and free. 1395 */ 1396 static void 1397 knote_drop(struct knote *kn, struct lwp *l, struct filedesc *fdp) 1398 { 1399 struct klist *list; 1400 1401 if (kn->kn_fop->f_isfd) 1402 list = &fdp->fd_knlist[kn->kn_id]; 1403 else 1404 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; 1405 1406 SLIST_REMOVE(list, kn, knote, kn_link); 1407 if (kn->kn_status & KN_QUEUED) 1408 knote_dequeue(kn); 1409 if (kn->kn_fop->f_isfd) 1410 FILE_UNUSE(kn->kn_fp, l); 1411 pool_put(&knote_pool, kn); 1412 } 1413 1414 1415 /* 1416 * Queue new event for knote. 1417 */ 1418 static void 1419 knote_enqueue(struct knote *kn) 1420 { 1421 struct kqueue *kq; 1422 int s; 1423 1424 kq = kn->kn_kq; 1425 KASSERT((kn->kn_status & KN_QUEUED) == 0); 1426 1427 s = splsched(); 1428 simple_lock(&kq->kq_lock); 1429 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 1430 kn->kn_status |= KN_QUEUED; 1431 kq->kq_count++; 1432 simple_unlock(&kq->kq_lock); 1433 splx(s); 1434 kqueue_wakeup(kq); 1435 } 1436 1437 /* 1438 * Dequeue event for knote. 1439 */ 1440 static void 1441 knote_dequeue(struct knote *kn) 1442 { 1443 struct kqueue *kq; 1444 int s; 1445 1446 KASSERT(kn->kn_status & KN_QUEUED); 1447 kq = kn->kn_kq; 1448 1449 s = splsched(); 1450 simple_lock(&kq->kq_lock); 1451 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1452 kn->kn_status &= ~KN_QUEUED; 1453 kq->kq_count--; 1454 simple_unlock(&kq->kq_lock); 1455 splx(s); 1456 } 1457