1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org> 5 * Copyright 2004 John-Mark Gurney <jmg@FreeBSD.org> 6 * Copyright (c) 2009 Apple, Inc. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 34 #include "opt_ktrace.h" 35 #include "opt_kqueue.h" 36 37 #ifdef COMPAT_FREEBSD11 38 #define _WANT_FREEBSD11_KEVENT 39 #endif 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/capsicum.h> 44 #include <sys/kernel.h> 45 #include <sys/limits.h> 46 #include <sys/lock.h> 47 #include <sys/mutex.h> 48 #include <sys/rwlock.h> 49 #include <sys/proc.h> 50 #include <sys/malloc.h> 51 #include <sys/unistd.h> 52 #include <sys/file.h> 53 #include <sys/filedesc.h> 54 #include <sys/filio.h> 55 #include <sys/fcntl.h> 56 #include <sys/kthread.h> 57 #include <sys/selinfo.h> 58 #include <sys/queue.h> 59 #include <sys/event.h> 60 #include <sys/eventvar.h> 61 #include <sys/poll.h> 62 #include <sys/protosw.h> 63 #include <sys/resourcevar.h> 64 #include <sys/sigio.h> 65 #include <sys/signalvar.h> 66 #include <sys/socket.h> 67 #include <sys/socketvar.h> 68 #include <sys/stat.h> 69 #include <sys/sysctl.h> 70 #include <sys/sysproto.h> 71 #include <sys/syscallsubr.h> 72 #include <sys/taskqueue.h> 73 #include <sys/uio.h> 74 #include <sys/user.h> 75 #ifdef KTRACE 76 #include <sys/ktrace.h> 77 #endif 78 #include <machine/atomic.h> 79 80 #include <vm/uma.h> 81 82 static MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system"); 83 84 /* 85 * This lock is used if multiple kq locks are required. This possibly 86 * should be made into a per proc lock. 87 */ 88 static struct mtx kq_global; 89 MTX_SYSINIT(kq_global, &kq_global, "kqueue order", MTX_DEF); 90 #define KQ_GLOBAL_LOCK(lck, haslck) do { \ 91 if (!haslck) \ 92 mtx_lock(lck); \ 93 haslck = 1; \ 94 } while (0) 95 #define KQ_GLOBAL_UNLOCK(lck, haslck) do { \ 96 if (haslck) \ 97 mtx_unlock(lck); \ 98 haslck = 0; \ 99 } while (0) 100 101 TASKQUEUE_DEFINE_THREAD(kqueue_ctx); 102 103 static int kevent_copyout(void *arg, struct kevent *kevp, int count); 104 static int kevent_copyin(void *arg, struct kevent *kevp, int count); 105 static int kqueue_register(struct kqueue *kq, struct kevent *kev, 106 struct thread *td, int mflag); 107 static int kqueue_acquire(struct file *fp, struct kqueue **kqp); 108 static void kqueue_release(struct kqueue *kq, int locked); 109 static void kqueue_destroy(struct kqueue *kq); 110 static void kqueue_drain(struct kqueue *kq, struct thread *td); 111 static int kqueue_expand(struct kqueue *kq, struct filterops *fops, 112 uintptr_t ident, int mflag); 113 static void kqueue_task(void *arg, int pending); 114 static int kqueue_scan(struct kqueue *kq, int maxevents, 115 struct kevent_copyops *k_ops, 116 const struct timespec *timeout, 117 struct kevent *keva, struct thread *td); 118 static void kqueue_wakeup(struct kqueue *kq); 119 static struct filterops *kqueue_fo_find(int filt); 120 static void kqueue_fo_release(int filt); 121 struct g_kevent_args; 122 static int kern_kevent_generic(struct thread *td, 123 struct g_kevent_args *uap, 124 struct kevent_copyops *k_ops, const char *struct_name); 125 126 static fo_ioctl_t kqueue_ioctl; 127 static fo_poll_t kqueue_poll; 128 static fo_kqfilter_t kqueue_kqfilter; 129 static fo_stat_t kqueue_stat; 130 static fo_close_t kqueue_close; 131 static fo_fill_kinfo_t kqueue_fill_kinfo; 132 133 static struct fileops kqueueops = { 134 .fo_read = invfo_rdwr, 135 .fo_write = invfo_rdwr, 136 .fo_truncate = invfo_truncate, 137 .fo_ioctl = kqueue_ioctl, 138 .fo_poll = kqueue_poll, 139 .fo_kqfilter = kqueue_kqfilter, 140 .fo_stat = kqueue_stat, 141 .fo_close = kqueue_close, 142 .fo_chmod = invfo_chmod, 143 .fo_chown = invfo_chown, 144 .fo_sendfile = invfo_sendfile, 145 .fo_fill_kinfo = kqueue_fill_kinfo, 146 }; 147 148 static int knote_attach(struct knote *kn, struct kqueue *kq); 149 static void knote_drop(struct knote *kn, struct thread *td); 150 static void knote_drop_detached(struct knote *kn, struct thread *td); 151 static void knote_enqueue(struct knote *kn); 152 static void knote_dequeue(struct knote *kn); 153 static void knote_init(void); 154 static struct knote *knote_alloc(int mflag); 155 static void knote_free(struct knote *kn); 156 157 static void filt_kqdetach(struct knote *kn); 158 static int filt_kqueue(struct knote *kn, long hint); 159 static int filt_procattach(struct knote *kn); 160 static void filt_procdetach(struct knote *kn); 161 static int filt_proc(struct knote *kn, long hint); 162 static int filt_fileattach(struct knote *kn); 163 static void filt_timerexpire(void *knx); 164 static void filt_timerexpire_l(struct knote *kn, bool proc_locked); 165 static int filt_timerattach(struct knote *kn); 166 static void filt_timerdetach(struct knote *kn); 167 static void filt_timerstart(struct knote *kn, sbintime_t to); 168 static void filt_timertouch(struct knote *kn, struct kevent *kev, 169 u_long type); 170 static int filt_timervalidate(struct knote *kn, sbintime_t *to); 171 static int filt_timer(struct knote *kn, long hint); 172 static int filt_userattach(struct knote *kn); 173 static void filt_userdetach(struct knote *kn); 174 static int filt_user(struct knote *kn, long hint); 175 static void filt_usertouch(struct knote *kn, struct kevent *kev, 176 u_long type); 177 178 static struct filterops file_filtops = { 179 .f_isfd = 1, 180 .f_attach = filt_fileattach, 181 }; 182 static struct filterops kqread_filtops = { 183 .f_isfd = 1, 184 .f_detach = filt_kqdetach, 185 .f_event = filt_kqueue, 186 }; 187 /* XXX - move to kern_proc.c? */ 188 static struct filterops proc_filtops = { 189 .f_isfd = 0, 190 .f_attach = filt_procattach, 191 .f_detach = filt_procdetach, 192 .f_event = filt_proc, 193 }; 194 static struct filterops timer_filtops = { 195 .f_isfd = 0, 196 .f_attach = filt_timerattach, 197 .f_detach = filt_timerdetach, 198 .f_event = filt_timer, 199 .f_touch = filt_timertouch, 200 }; 201 static struct filterops user_filtops = { 202 .f_attach = filt_userattach, 203 .f_detach = filt_userdetach, 204 .f_event = filt_user, 205 .f_touch = filt_usertouch, 206 }; 207 208 static uma_zone_t knote_zone; 209 static unsigned int __exclusive_cache_line kq_ncallouts; 210 static unsigned int kq_calloutmax = 4 * 1024; 211 SYSCTL_UINT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW, 212 &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue"); 213 214 /* XXX - ensure not influx ? */ 215 #define KNOTE_ACTIVATE(kn, islock) do { \ 216 if ((islock)) \ 217 mtx_assert(&(kn)->kn_kq->kq_lock, MA_OWNED); \ 218 else \ 219 KQ_LOCK((kn)->kn_kq); \ 220 (kn)->kn_status |= KN_ACTIVE; \ 221 if (((kn)->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 222 knote_enqueue((kn)); \ 223 if (!(islock)) \ 224 KQ_UNLOCK((kn)->kn_kq); \ 225 } while (0) 226 #define KQ_LOCK(kq) do { \ 227 mtx_lock(&(kq)->kq_lock); \ 228 } while (0) 229 #define KQ_FLUX_WAKEUP(kq) do { \ 230 if (((kq)->kq_state & KQ_FLUXWAIT) == KQ_FLUXWAIT) { \ 231 (kq)->kq_state &= ~KQ_FLUXWAIT; \ 232 wakeup((kq)); \ 233 } \ 234 } while (0) 235 #define KQ_UNLOCK_FLUX(kq) do { \ 236 KQ_FLUX_WAKEUP(kq); \ 237 mtx_unlock(&(kq)->kq_lock); \ 238 } while (0) 239 #define KQ_UNLOCK(kq) do { \ 240 mtx_unlock(&(kq)->kq_lock); \ 241 } while (0) 242 #define KQ_OWNED(kq) do { \ 243 mtx_assert(&(kq)->kq_lock, MA_OWNED); \ 244 } while (0) 245 #define KQ_NOTOWNED(kq) do { \ 246 mtx_assert(&(kq)->kq_lock, MA_NOTOWNED); \ 247 } while (0) 248 249 static struct knlist * 250 kn_list_lock(struct knote *kn) 251 { 252 struct knlist *knl; 253 254 knl = kn->kn_knlist; 255 if (knl != NULL) 256 knl->kl_lock(knl->kl_lockarg); 257 return (knl); 258 } 259 260 static void 261 kn_list_unlock(struct knlist *knl) 262 { 263 bool do_free; 264 265 if (knl == NULL) 266 return; 267 do_free = knl->kl_autodestroy && knlist_empty(knl); 268 knl->kl_unlock(knl->kl_lockarg); 269 if (do_free) { 270 knlist_destroy(knl); 271 free(knl, M_KQUEUE); 272 } 273 } 274 275 static bool 276 kn_in_flux(struct knote *kn) 277 { 278 279 return (kn->kn_influx > 0); 280 } 281 282 static void 283 kn_enter_flux(struct knote *kn) 284 { 285 286 KQ_OWNED(kn->kn_kq); 287 MPASS(kn->kn_influx < INT_MAX); 288 kn->kn_influx++; 289 } 290 291 static bool 292 kn_leave_flux(struct knote *kn) 293 { 294 295 KQ_OWNED(kn->kn_kq); 296 MPASS(kn->kn_influx > 0); 297 kn->kn_influx--; 298 return (kn->kn_influx == 0); 299 } 300 301 #define KNL_ASSERT_LOCK(knl, islocked) do { \ 302 if (islocked) \ 303 KNL_ASSERT_LOCKED(knl); \ 304 else \ 305 KNL_ASSERT_UNLOCKED(knl); \ 306 } while (0) 307 #ifdef INVARIANTS 308 #define KNL_ASSERT_LOCKED(knl) do { \ 309 knl->kl_assert_lock((knl)->kl_lockarg, LA_LOCKED); \ 310 } while (0) 311 #define KNL_ASSERT_UNLOCKED(knl) do { \ 312 knl->kl_assert_lock((knl)->kl_lockarg, LA_UNLOCKED); \ 313 } while (0) 314 #else /* !INVARIANTS */ 315 #define KNL_ASSERT_LOCKED(knl) do {} while (0) 316 #define KNL_ASSERT_UNLOCKED(knl) do {} while (0) 317 #endif /* INVARIANTS */ 318 319 #ifndef KN_HASHSIZE 320 #define KN_HASHSIZE 64 /* XXX should be tunable */ 321 #endif 322 323 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 324 325 static int 326 filt_nullattach(struct knote *kn) 327 { 328 329 return (ENXIO); 330 }; 331 332 struct filterops null_filtops = { 333 .f_isfd = 0, 334 .f_attach = filt_nullattach, 335 }; 336 337 /* XXX - make SYSINIT to add these, and move into respective modules. */ 338 extern struct filterops sig_filtops; 339 extern struct filterops fs_filtops; 340 341 /* 342 * Table for for all system-defined filters. 343 */ 344 static struct mtx filterops_lock; 345 MTX_SYSINIT(kqueue_filterops, &filterops_lock, "protect sysfilt_ops", 346 MTX_DEF); 347 static struct { 348 struct filterops *for_fop; 349 int for_nolock; 350 int for_refcnt; 351 } sysfilt_ops[EVFILT_SYSCOUNT] = { 352 { &file_filtops, 1 }, /* EVFILT_READ */ 353 { &file_filtops, 1 }, /* EVFILT_WRITE */ 354 { &null_filtops }, /* EVFILT_AIO */ 355 { &file_filtops, 1 }, /* EVFILT_VNODE */ 356 { &proc_filtops, 1 }, /* EVFILT_PROC */ 357 { &sig_filtops, 1 }, /* EVFILT_SIGNAL */ 358 { &timer_filtops, 1 }, /* EVFILT_TIMER */ 359 { &file_filtops, 1 }, /* EVFILT_PROCDESC */ 360 { &fs_filtops, 1 }, /* EVFILT_FS */ 361 { &null_filtops }, /* EVFILT_LIO */ 362 { &user_filtops, 1 }, /* EVFILT_USER */ 363 { &null_filtops }, /* EVFILT_SENDFILE */ 364 { &file_filtops, 1 }, /* EVFILT_EMPTY */ 365 }; 366 367 /* 368 * Simple redirection for all cdevsw style objects to call their fo_kqfilter 369 * method. 370 */ 371 static int 372 filt_fileattach(struct knote *kn) 373 { 374 375 return (fo_kqfilter(kn->kn_fp, kn)); 376 } 377 378 /*ARGSUSED*/ 379 static int 380 kqueue_kqfilter(struct file *fp, struct knote *kn) 381 { 382 struct kqueue *kq = kn->kn_fp->f_data; 383 384 if (kn->kn_filter != EVFILT_READ) 385 return (EINVAL); 386 387 kn->kn_status |= KN_KQUEUE; 388 kn->kn_fop = &kqread_filtops; 389 knlist_add(&kq->kq_sel.si_note, kn, 0); 390 391 return (0); 392 } 393 394 static void 395 filt_kqdetach(struct knote *kn) 396 { 397 struct kqueue *kq = kn->kn_fp->f_data; 398 399 knlist_remove(&kq->kq_sel.si_note, kn, 0); 400 } 401 402 /*ARGSUSED*/ 403 static int 404 filt_kqueue(struct knote *kn, long hint) 405 { 406 struct kqueue *kq = kn->kn_fp->f_data; 407 408 kn->kn_data = kq->kq_count; 409 return (kn->kn_data > 0); 410 } 411 412 /* XXX - move to kern_proc.c? */ 413 static int 414 filt_procattach(struct knote *kn) 415 { 416 struct proc *p; 417 int error; 418 bool exiting, immediate; 419 420 exiting = immediate = false; 421 if (kn->kn_sfflags & NOTE_EXIT) 422 p = pfind_any(kn->kn_id); 423 else 424 p = pfind(kn->kn_id); 425 if (p == NULL) 426 return (ESRCH); 427 if (p->p_flag & P_WEXIT) 428 exiting = true; 429 430 if ((error = p_cansee(curthread, p))) { 431 PROC_UNLOCK(p); 432 return (error); 433 } 434 435 kn->kn_ptr.p_proc = p; 436 kn->kn_flags |= EV_CLEAR; /* automatically set */ 437 438 /* 439 * Internal flag indicating registration done by kernel for the 440 * purposes of getting a NOTE_CHILD notification. 441 */ 442 if (kn->kn_flags & EV_FLAG2) { 443 kn->kn_flags &= ~EV_FLAG2; 444 kn->kn_data = kn->kn_sdata; /* ppid */ 445 kn->kn_fflags = NOTE_CHILD; 446 kn->kn_sfflags &= ~(NOTE_EXIT | NOTE_EXEC | NOTE_FORK); 447 immediate = true; /* Force immediate activation of child note. */ 448 } 449 /* 450 * Internal flag indicating registration done by kernel (for other than 451 * NOTE_CHILD). 452 */ 453 if (kn->kn_flags & EV_FLAG1) { 454 kn->kn_flags &= ~EV_FLAG1; 455 } 456 457 knlist_add(p->p_klist, kn, 1); 458 459 /* 460 * Immediately activate any child notes or, in the case of a zombie 461 * target process, exit notes. The latter is necessary to handle the 462 * case where the target process, e.g. a child, dies before the kevent 463 * is registered. 464 */ 465 if (immediate || (exiting && filt_proc(kn, NOTE_EXIT))) 466 KNOTE_ACTIVATE(kn, 0); 467 468 PROC_UNLOCK(p); 469 470 return (0); 471 } 472 473 /* 474 * The knote may be attached to a different process, which may exit, 475 * leaving nothing for the knote to be attached to. So when the process 476 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 477 * it will be deleted when read out. However, as part of the knote deletion, 478 * this routine is called, so a check is needed to avoid actually performing 479 * a detach, because the original process does not exist any more. 480 */ 481 /* XXX - move to kern_proc.c? */ 482 static void 483 filt_procdetach(struct knote *kn) 484 { 485 486 knlist_remove(kn->kn_knlist, kn, 0); 487 kn->kn_ptr.p_proc = NULL; 488 } 489 490 /* XXX - move to kern_proc.c? */ 491 static int 492 filt_proc(struct knote *kn, long hint) 493 { 494 struct proc *p; 495 u_int event; 496 497 p = kn->kn_ptr.p_proc; 498 if (p == NULL) /* already activated, from attach filter */ 499 return (0); 500 501 /* Mask off extra data. */ 502 event = (u_int)hint & NOTE_PCTRLMASK; 503 504 /* If the user is interested in this event, record it. */ 505 if (kn->kn_sfflags & event) 506 kn->kn_fflags |= event; 507 508 /* Process is gone, so flag the event as finished. */ 509 if (event == NOTE_EXIT) { 510 kn->kn_flags |= EV_EOF | EV_ONESHOT; 511 kn->kn_ptr.p_proc = NULL; 512 if (kn->kn_fflags & NOTE_EXIT) 513 kn->kn_data = KW_EXITCODE(p->p_xexit, p->p_xsig); 514 if (kn->kn_fflags == 0) 515 kn->kn_flags |= EV_DROP; 516 return (1); 517 } 518 519 return (kn->kn_fflags != 0); 520 } 521 522 /* 523 * Called when the process forked. It mostly does the same as the 524 * knote(), activating all knotes registered to be activated when the 525 * process forked. Additionally, for each knote attached to the 526 * parent, check whether user wants to track the new process. If so 527 * attach a new knote to it, and immediately report an event with the 528 * child's pid. 529 */ 530 void 531 knote_fork(struct knlist *list, int pid) 532 { 533 struct kqueue *kq; 534 struct knote *kn; 535 struct kevent kev; 536 int error; 537 538 MPASS(list != NULL); 539 KNL_ASSERT_LOCKED(list); 540 if (SLIST_EMPTY(&list->kl_list)) 541 return; 542 543 memset(&kev, 0, sizeof(kev)); 544 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { 545 kq = kn->kn_kq; 546 KQ_LOCK(kq); 547 if (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0) { 548 KQ_UNLOCK(kq); 549 continue; 550 } 551 552 /* 553 * The same as knote(), activate the event. 554 */ 555 if ((kn->kn_sfflags & NOTE_TRACK) == 0) { 556 if (kn->kn_fop->f_event(kn, NOTE_FORK)) 557 KNOTE_ACTIVATE(kn, 1); 558 KQ_UNLOCK(kq); 559 continue; 560 } 561 562 /* 563 * The NOTE_TRACK case. In addition to the activation 564 * of the event, we need to register new events to 565 * track the child. Drop the locks in preparation for 566 * the call to kqueue_register(). 567 */ 568 kn_enter_flux(kn); 569 KQ_UNLOCK(kq); 570 list->kl_unlock(list->kl_lockarg); 571 572 /* 573 * Activate existing knote and register tracking knotes with 574 * new process. 575 * 576 * First register a knote to get just the child notice. This 577 * must be a separate note from a potential NOTE_EXIT 578 * notification since both NOTE_CHILD and NOTE_EXIT are defined 579 * to use the data field (in conflicting ways). 580 */ 581 kev.ident = pid; 582 kev.filter = kn->kn_filter; 583 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_ONESHOT | 584 EV_FLAG2; 585 kev.fflags = kn->kn_sfflags; 586 kev.data = kn->kn_id; /* parent */ 587 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 588 error = kqueue_register(kq, &kev, NULL, M_NOWAIT); 589 if (error) 590 kn->kn_fflags |= NOTE_TRACKERR; 591 592 /* 593 * Then register another knote to track other potential events 594 * from the new process. 595 */ 596 kev.ident = pid; 597 kev.filter = kn->kn_filter; 598 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 599 kev.fflags = kn->kn_sfflags; 600 kev.data = kn->kn_id; /* parent */ 601 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 602 error = kqueue_register(kq, &kev, NULL, M_NOWAIT); 603 if (error) 604 kn->kn_fflags |= NOTE_TRACKERR; 605 if (kn->kn_fop->f_event(kn, NOTE_FORK)) 606 KNOTE_ACTIVATE(kn, 0); 607 list->kl_lock(list->kl_lockarg); 608 KQ_LOCK(kq); 609 kn_leave_flux(kn); 610 KQ_UNLOCK_FLUX(kq); 611 } 612 } 613 614 /* 615 * XXX: EVFILT_TIMER should perhaps live in kern_time.c beside the 616 * interval timer support code. 617 */ 618 619 #define NOTE_TIMER_PRECMASK \ 620 (NOTE_SECONDS | NOTE_MSECONDS | NOTE_USECONDS | NOTE_NSECONDS) 621 622 static sbintime_t 623 timer2sbintime(int64_t data, int flags) 624 { 625 int64_t secs; 626 627 /* 628 * Macros for converting to the fractional second portion of an 629 * sbintime_t using 64bit multiplication to improve precision. 630 */ 631 #define NS_TO_SBT(ns) (((ns) * (((uint64_t)1 << 63) / 500000000)) >> 32) 632 #define US_TO_SBT(us) (((us) * (((uint64_t)1 << 63) / 500000)) >> 32) 633 #define MS_TO_SBT(ms) (((ms) * (((uint64_t)1 << 63) / 500)) >> 32) 634 switch (flags & NOTE_TIMER_PRECMASK) { 635 case NOTE_SECONDS: 636 #ifdef __LP64__ 637 if (data > (SBT_MAX / SBT_1S)) 638 return (SBT_MAX); 639 #endif 640 return ((sbintime_t)data << 32); 641 case NOTE_MSECONDS: /* FALLTHROUGH */ 642 case 0: 643 if (data >= 1000) { 644 secs = data / 1000; 645 #ifdef __LP64__ 646 if (secs > (SBT_MAX / SBT_1S)) 647 return (SBT_MAX); 648 #endif 649 return (secs << 32 | MS_TO_SBT(data % 1000)); 650 } 651 return (MS_TO_SBT(data)); 652 case NOTE_USECONDS: 653 if (data >= 1000000) { 654 secs = data / 1000000; 655 #ifdef __LP64__ 656 if (secs > (SBT_MAX / SBT_1S)) 657 return (SBT_MAX); 658 #endif 659 return (secs << 32 | US_TO_SBT(data % 1000000)); 660 } 661 return (US_TO_SBT(data)); 662 case NOTE_NSECONDS: 663 if (data >= 1000000000) { 664 secs = data / 1000000000; 665 #ifdef __LP64__ 666 if (secs > (SBT_MAX / SBT_1S)) 667 return (SBT_MAX); 668 #endif 669 return (secs << 32 | NS_TO_SBT(data % 1000000000)); 670 } 671 return (NS_TO_SBT(data)); 672 default: 673 break; 674 } 675 return (-1); 676 } 677 678 struct kq_timer_cb_data { 679 struct callout c; 680 struct proc *p; 681 struct knote *kn; 682 int cpuid; 683 int flags; 684 TAILQ_ENTRY(kq_timer_cb_data) link; 685 sbintime_t next; /* next timer event fires at */ 686 sbintime_t to; /* precalculated timer period, 0 for abs */ 687 }; 688 689 #define KQ_TIMER_CB_ENQUEUED 0x01 690 691 static void 692 kqtimer_sched_callout(struct kq_timer_cb_data *kc) 693 { 694 callout_reset_sbt_on(&kc->c, kc->next, 0, filt_timerexpire, kc->kn, 695 kc->cpuid, C_ABSOLUTE); 696 } 697 698 void 699 kqtimer_proc_continue(struct proc *p) 700 { 701 struct kq_timer_cb_data *kc, *kc1; 702 struct bintime bt; 703 sbintime_t now; 704 705 PROC_LOCK_ASSERT(p, MA_OWNED); 706 707 getboottimebin(&bt); 708 now = bttosbt(bt); 709 710 TAILQ_FOREACH_SAFE(kc, &p->p_kqtim_stop, link, kc1) { 711 TAILQ_REMOVE(&p->p_kqtim_stop, kc, link); 712 kc->flags &= ~KQ_TIMER_CB_ENQUEUED; 713 if (kc->next <= now) 714 filt_timerexpire_l(kc->kn, true); 715 else 716 kqtimer_sched_callout(kc); 717 } 718 } 719 720 static void 721 filt_timerexpire_l(struct knote *kn, bool proc_locked) 722 { 723 struct kq_timer_cb_data *kc; 724 struct proc *p; 725 uint64_t delta; 726 sbintime_t now; 727 728 kc = kn->kn_ptr.p_v; 729 730 if ((kn->kn_flags & EV_ONESHOT) != 0 || kc->to == 0) { 731 kn->kn_data++; 732 KNOTE_ACTIVATE(kn, 0); 733 return; 734 } 735 736 now = sbinuptime(); 737 if (now >= kc->next) { 738 delta = (now - kc->next) / kc->to; 739 if (delta == 0) 740 delta = 1; 741 kn->kn_data += delta; 742 kc->next += (delta + 1) * kc->to; 743 if (now >= kc->next) /* overflow */ 744 kc->next = now + kc->to; 745 KNOTE_ACTIVATE(kn, 0); /* XXX - handle locking */ 746 } 747 748 /* 749 * Initial check for stopped kc->p is racy. It is fine to 750 * miss the set of the stop flags, at worst we would schedule 751 * one more callout. On the other hand, it is not fine to not 752 * schedule when we we missed clearing of the flags, we 753 * recheck them under the lock and observe consistent state. 754 */ 755 p = kc->p; 756 if (P_SHOULDSTOP(p) || P_KILLED(p)) { 757 if (!proc_locked) 758 PROC_LOCK(p); 759 if (P_SHOULDSTOP(p) || P_KILLED(p)) { 760 if ((kc->flags & KQ_TIMER_CB_ENQUEUED) == 0) { 761 kc->flags |= KQ_TIMER_CB_ENQUEUED; 762 TAILQ_INSERT_TAIL(&p->p_kqtim_stop, kc, link); 763 } 764 if (!proc_locked) 765 PROC_UNLOCK(p); 766 return; 767 } 768 if (!proc_locked) 769 PROC_UNLOCK(p); 770 } 771 kqtimer_sched_callout(kc); 772 } 773 774 static void 775 filt_timerexpire(void *knx) 776 { 777 filt_timerexpire_l(knx, false); 778 } 779 780 /* 781 * data contains amount of time to sleep 782 */ 783 static int 784 filt_timervalidate(struct knote *kn, sbintime_t *to) 785 { 786 struct bintime bt; 787 sbintime_t sbt; 788 789 if (kn->kn_sdata < 0) 790 return (EINVAL); 791 if (kn->kn_sdata == 0 && (kn->kn_flags & EV_ONESHOT) == 0) 792 kn->kn_sdata = 1; 793 /* 794 * The only fflags values supported are the timer unit 795 * (precision) and the absolute time indicator. 796 */ 797 if ((kn->kn_sfflags & ~(NOTE_TIMER_PRECMASK | NOTE_ABSTIME)) != 0) 798 return (EINVAL); 799 800 *to = timer2sbintime(kn->kn_sdata, kn->kn_sfflags); 801 if (*to < 0) 802 return (EINVAL); 803 if ((kn->kn_sfflags & NOTE_ABSTIME) != 0) { 804 getboottimebin(&bt); 805 sbt = bttosbt(bt); 806 *to = MAX(0, *to - sbt); 807 } 808 return (0); 809 } 810 811 static int 812 filt_timerattach(struct knote *kn) 813 { 814 struct kq_timer_cb_data *kc; 815 sbintime_t to; 816 int error; 817 818 to = -1; 819 error = filt_timervalidate(kn, &to); 820 if (error != 0) 821 return (error); 822 KASSERT((kn->kn_flags & EV_ONESHOT) != 0 || to > 0, 823 ("%s: periodic timer has a calculated zero timeout", __func__)); 824 KASSERT(to >= 0, 825 ("%s: timer has a calculated negative timeout", __func__)); 826 827 if (atomic_fetchadd_int(&kq_ncallouts, 1) + 1 > kq_calloutmax) { 828 atomic_subtract_int(&kq_ncallouts, 1); 829 return (ENOMEM); 830 } 831 832 if ((kn->kn_sfflags & NOTE_ABSTIME) == 0) 833 kn->kn_flags |= EV_CLEAR; /* automatically set */ 834 kn->kn_status &= ~KN_DETACHED; /* knlist_add clears it */ 835 kn->kn_ptr.p_v = kc = malloc(sizeof(*kc), M_KQUEUE, M_WAITOK); 836 kc->kn = kn; 837 kc->p = curproc; 838 kc->cpuid = PCPU_GET(cpuid); 839 kc->flags = 0; 840 callout_init(&kc->c, 1); 841 filt_timerstart(kn, to); 842 843 return (0); 844 } 845 846 static void 847 filt_timerstart(struct knote *kn, sbintime_t to) 848 { 849 struct kq_timer_cb_data *kc; 850 851 kc = kn->kn_ptr.p_v; 852 if ((kn->kn_sfflags & NOTE_ABSTIME) != 0) { 853 kc->next = to; 854 kc->to = 0; 855 } else { 856 kc->next = to + sbinuptime(); 857 kc->to = to; 858 } 859 kqtimer_sched_callout(kc); 860 } 861 862 static void 863 filt_timerdetach(struct knote *kn) 864 { 865 struct kq_timer_cb_data *kc; 866 unsigned int old __unused; 867 bool pending; 868 869 kc = kn->kn_ptr.p_v; 870 do { 871 callout_drain(&kc->c); 872 873 /* 874 * kqtimer_proc_continue() might have rescheduled this callout. 875 * Double-check, using the process mutex as an interlock. 876 */ 877 PROC_LOCK(kc->p); 878 if ((kc->flags & KQ_TIMER_CB_ENQUEUED) != 0) { 879 kc->flags &= ~KQ_TIMER_CB_ENQUEUED; 880 TAILQ_REMOVE(&kc->p->p_kqtim_stop, kc, link); 881 } 882 pending = callout_pending(&kc->c); 883 PROC_UNLOCK(kc->p); 884 } while (pending); 885 free(kc, M_KQUEUE); 886 old = atomic_fetchadd_int(&kq_ncallouts, -1); 887 KASSERT(old > 0, ("Number of callouts cannot become negative")); 888 kn->kn_status |= KN_DETACHED; /* knlist_remove sets it */ 889 } 890 891 static void 892 filt_timertouch(struct knote *kn, struct kevent *kev, u_long type) 893 { 894 struct kq_timer_cb_data *kc; 895 struct kqueue *kq; 896 sbintime_t to; 897 int error; 898 899 switch (type) { 900 case EVENT_REGISTER: 901 /* Handle re-added timers that update data/fflags */ 902 if (kev->flags & EV_ADD) { 903 kc = kn->kn_ptr.p_v; 904 905 /* Drain any existing callout. */ 906 callout_drain(&kc->c); 907 908 /* Throw away any existing undelivered record 909 * of the timer expiration. This is done under 910 * the presumption that if a process is 911 * re-adding this timer with new parameters, 912 * it is no longer interested in what may have 913 * happened under the old parameters. If it is 914 * interested, it can wait for the expiration, 915 * delete the old timer definition, and then 916 * add the new one. 917 * 918 * This has to be done while the kq is locked: 919 * - if enqueued, dequeue 920 * - make it no longer active 921 * - clear the count of expiration events 922 */ 923 kq = kn->kn_kq; 924 KQ_LOCK(kq); 925 if (kn->kn_status & KN_QUEUED) 926 knote_dequeue(kn); 927 928 kn->kn_status &= ~KN_ACTIVE; 929 kn->kn_data = 0; 930 KQ_UNLOCK(kq); 931 932 /* Reschedule timer based on new data/fflags */ 933 kn->kn_sfflags = kev->fflags; 934 kn->kn_sdata = kev->data; 935 error = filt_timervalidate(kn, &to); 936 if (error != 0) { 937 kn->kn_flags |= EV_ERROR; 938 kn->kn_data = error; 939 } else 940 filt_timerstart(kn, to); 941 } 942 break; 943 944 case EVENT_PROCESS: 945 *kev = kn->kn_kevent; 946 if (kn->kn_flags & EV_CLEAR) { 947 kn->kn_data = 0; 948 kn->kn_fflags = 0; 949 } 950 break; 951 952 default: 953 panic("filt_timertouch() - invalid type (%ld)", type); 954 break; 955 } 956 } 957 958 static int 959 filt_timer(struct knote *kn, long hint) 960 { 961 962 return (kn->kn_data != 0); 963 } 964 965 static int 966 filt_userattach(struct knote *kn) 967 { 968 969 /* 970 * EVFILT_USER knotes are not attached to anything in the kernel. 971 */ 972 kn->kn_hook = NULL; 973 if (kn->kn_fflags & NOTE_TRIGGER) 974 kn->kn_hookid = 1; 975 else 976 kn->kn_hookid = 0; 977 return (0); 978 } 979 980 static void 981 filt_userdetach(__unused struct knote *kn) 982 { 983 984 /* 985 * EVFILT_USER knotes are not attached to anything in the kernel. 986 */ 987 } 988 989 static int 990 filt_user(struct knote *kn, __unused long hint) 991 { 992 993 return (kn->kn_hookid); 994 } 995 996 static void 997 filt_usertouch(struct knote *kn, struct kevent *kev, u_long type) 998 { 999 u_int ffctrl; 1000 1001 switch (type) { 1002 case EVENT_REGISTER: 1003 if (kev->fflags & NOTE_TRIGGER) 1004 kn->kn_hookid = 1; 1005 1006 ffctrl = kev->fflags & NOTE_FFCTRLMASK; 1007 kev->fflags &= NOTE_FFLAGSMASK; 1008 switch (ffctrl) { 1009 case NOTE_FFNOP: 1010 break; 1011 1012 case NOTE_FFAND: 1013 kn->kn_sfflags &= kev->fflags; 1014 break; 1015 1016 case NOTE_FFOR: 1017 kn->kn_sfflags |= kev->fflags; 1018 break; 1019 1020 case NOTE_FFCOPY: 1021 kn->kn_sfflags = kev->fflags; 1022 break; 1023 1024 default: 1025 /* XXX Return error? */ 1026 break; 1027 } 1028 kn->kn_sdata = kev->data; 1029 if (kev->flags & EV_CLEAR) { 1030 kn->kn_hookid = 0; 1031 kn->kn_data = 0; 1032 kn->kn_fflags = 0; 1033 } 1034 break; 1035 1036 case EVENT_PROCESS: 1037 *kev = kn->kn_kevent; 1038 kev->fflags = kn->kn_sfflags; 1039 kev->data = kn->kn_sdata; 1040 if (kn->kn_flags & EV_CLEAR) { 1041 kn->kn_hookid = 0; 1042 kn->kn_data = 0; 1043 kn->kn_fflags = 0; 1044 } 1045 break; 1046 1047 default: 1048 panic("filt_usertouch() - invalid type (%ld)", type); 1049 break; 1050 } 1051 } 1052 1053 int 1054 sys_kqueue(struct thread *td, struct kqueue_args *uap) 1055 { 1056 1057 return (kern_kqueue(td, 0, NULL)); 1058 } 1059 1060 static void 1061 kqueue_init(struct kqueue *kq) 1062 { 1063 1064 mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF | MTX_DUPOK); 1065 TAILQ_INIT(&kq->kq_head); 1066 knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock); 1067 TASK_INIT(&kq->kq_task, 0, kqueue_task, kq); 1068 } 1069 1070 int 1071 kern_kqueue(struct thread *td, int flags, struct filecaps *fcaps) 1072 { 1073 struct filedesc *fdp; 1074 struct kqueue *kq; 1075 struct file *fp; 1076 struct ucred *cred; 1077 int fd, error; 1078 1079 fdp = td->td_proc->p_fd; 1080 cred = td->td_ucred; 1081 if (!chgkqcnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_KQUEUES))) 1082 return (ENOMEM); 1083 1084 error = falloc_caps(td, &fp, &fd, flags, fcaps); 1085 if (error != 0) { 1086 chgkqcnt(cred->cr_ruidinfo, -1, 0); 1087 return (error); 1088 } 1089 1090 /* An extra reference on `fp' has been held for us by falloc(). */ 1091 kq = malloc(sizeof *kq, M_KQUEUE, M_WAITOK | M_ZERO); 1092 kqueue_init(kq); 1093 kq->kq_fdp = fdp; 1094 kq->kq_cred = crhold(cred); 1095 1096 FILEDESC_XLOCK(fdp); 1097 TAILQ_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list); 1098 FILEDESC_XUNLOCK(fdp); 1099 1100 finit(fp, FREAD | FWRITE, DTYPE_KQUEUE, kq, &kqueueops); 1101 fdrop(fp, td); 1102 1103 td->td_retval[0] = fd; 1104 return (0); 1105 } 1106 1107 struct g_kevent_args { 1108 int fd; 1109 void *changelist; 1110 int nchanges; 1111 void *eventlist; 1112 int nevents; 1113 const struct timespec *timeout; 1114 }; 1115 1116 int 1117 sys_kevent(struct thread *td, struct kevent_args *uap) 1118 { 1119 struct kevent_copyops k_ops = { 1120 .arg = uap, 1121 .k_copyout = kevent_copyout, 1122 .k_copyin = kevent_copyin, 1123 .kevent_size = sizeof(struct kevent), 1124 }; 1125 struct g_kevent_args gk_args = { 1126 .fd = uap->fd, 1127 .changelist = uap->changelist, 1128 .nchanges = uap->nchanges, 1129 .eventlist = uap->eventlist, 1130 .nevents = uap->nevents, 1131 .timeout = uap->timeout, 1132 }; 1133 1134 return (kern_kevent_generic(td, &gk_args, &k_ops, "kevent")); 1135 } 1136 1137 static int 1138 kern_kevent_generic(struct thread *td, struct g_kevent_args *uap, 1139 struct kevent_copyops *k_ops, const char *struct_name) 1140 { 1141 struct timespec ts, *tsp; 1142 #ifdef KTRACE 1143 struct kevent *eventlist = uap->eventlist; 1144 #endif 1145 int error; 1146 1147 if (uap->timeout != NULL) { 1148 error = copyin(uap->timeout, &ts, sizeof(ts)); 1149 if (error) 1150 return (error); 1151 tsp = &ts; 1152 } else 1153 tsp = NULL; 1154 1155 #ifdef KTRACE 1156 if (KTRPOINT(td, KTR_STRUCT_ARRAY)) 1157 ktrstructarray(struct_name, UIO_USERSPACE, uap->changelist, 1158 uap->nchanges, k_ops->kevent_size); 1159 #endif 1160 1161 error = kern_kevent(td, uap->fd, uap->nchanges, uap->nevents, 1162 k_ops, tsp); 1163 1164 #ifdef KTRACE 1165 if (error == 0 && KTRPOINT(td, KTR_STRUCT_ARRAY)) 1166 ktrstructarray(struct_name, UIO_USERSPACE, eventlist, 1167 td->td_retval[0], k_ops->kevent_size); 1168 #endif 1169 1170 return (error); 1171 } 1172 1173 /* 1174 * Copy 'count' items into the destination list pointed to by uap->eventlist. 1175 */ 1176 static int 1177 kevent_copyout(void *arg, struct kevent *kevp, int count) 1178 { 1179 struct kevent_args *uap; 1180 int error; 1181 1182 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1183 uap = (struct kevent_args *)arg; 1184 1185 error = copyout(kevp, uap->eventlist, count * sizeof *kevp); 1186 if (error == 0) 1187 uap->eventlist += count; 1188 return (error); 1189 } 1190 1191 /* 1192 * Copy 'count' items from the list pointed to by uap->changelist. 1193 */ 1194 static int 1195 kevent_copyin(void *arg, struct kevent *kevp, int count) 1196 { 1197 struct kevent_args *uap; 1198 int error; 1199 1200 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1201 uap = (struct kevent_args *)arg; 1202 1203 error = copyin(uap->changelist, kevp, count * sizeof *kevp); 1204 if (error == 0) 1205 uap->changelist += count; 1206 return (error); 1207 } 1208 1209 #ifdef COMPAT_FREEBSD11 1210 static int 1211 kevent11_copyout(void *arg, struct kevent *kevp, int count) 1212 { 1213 struct freebsd11_kevent_args *uap; 1214 struct kevent_freebsd11 kev11; 1215 int error, i; 1216 1217 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1218 uap = (struct freebsd11_kevent_args *)arg; 1219 1220 for (i = 0; i < count; i++) { 1221 kev11.ident = kevp->ident; 1222 kev11.filter = kevp->filter; 1223 kev11.flags = kevp->flags; 1224 kev11.fflags = kevp->fflags; 1225 kev11.data = kevp->data; 1226 kev11.udata = kevp->udata; 1227 error = copyout(&kev11, uap->eventlist, sizeof(kev11)); 1228 if (error != 0) 1229 break; 1230 uap->eventlist++; 1231 kevp++; 1232 } 1233 return (error); 1234 } 1235 1236 /* 1237 * Copy 'count' items from the list pointed to by uap->changelist. 1238 */ 1239 static int 1240 kevent11_copyin(void *arg, struct kevent *kevp, int count) 1241 { 1242 struct freebsd11_kevent_args *uap; 1243 struct kevent_freebsd11 kev11; 1244 int error, i; 1245 1246 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1247 uap = (struct freebsd11_kevent_args *)arg; 1248 1249 for (i = 0; i < count; i++) { 1250 error = copyin(uap->changelist, &kev11, sizeof(kev11)); 1251 if (error != 0) 1252 break; 1253 kevp->ident = kev11.ident; 1254 kevp->filter = kev11.filter; 1255 kevp->flags = kev11.flags; 1256 kevp->fflags = kev11.fflags; 1257 kevp->data = (uintptr_t)kev11.data; 1258 kevp->udata = kev11.udata; 1259 bzero(&kevp->ext, sizeof(kevp->ext)); 1260 uap->changelist++; 1261 kevp++; 1262 } 1263 return (error); 1264 } 1265 1266 int 1267 freebsd11_kevent(struct thread *td, struct freebsd11_kevent_args *uap) 1268 { 1269 struct kevent_copyops k_ops = { 1270 .arg = uap, 1271 .k_copyout = kevent11_copyout, 1272 .k_copyin = kevent11_copyin, 1273 .kevent_size = sizeof(struct kevent_freebsd11), 1274 }; 1275 struct g_kevent_args gk_args = { 1276 .fd = uap->fd, 1277 .changelist = uap->changelist, 1278 .nchanges = uap->nchanges, 1279 .eventlist = uap->eventlist, 1280 .nevents = uap->nevents, 1281 .timeout = uap->timeout, 1282 }; 1283 1284 return (kern_kevent_generic(td, &gk_args, &k_ops, "kevent_freebsd11")); 1285 } 1286 #endif 1287 1288 int 1289 kern_kevent(struct thread *td, int fd, int nchanges, int nevents, 1290 struct kevent_copyops *k_ops, const struct timespec *timeout) 1291 { 1292 cap_rights_t rights; 1293 struct file *fp; 1294 int error; 1295 1296 cap_rights_init_zero(&rights); 1297 if (nchanges > 0) 1298 cap_rights_set_one(&rights, CAP_KQUEUE_CHANGE); 1299 if (nevents > 0) 1300 cap_rights_set_one(&rights, CAP_KQUEUE_EVENT); 1301 error = fget(td, fd, &rights, &fp); 1302 if (error != 0) 1303 return (error); 1304 1305 error = kern_kevent_fp(td, fp, nchanges, nevents, k_ops, timeout); 1306 fdrop(fp, td); 1307 1308 return (error); 1309 } 1310 1311 static int 1312 kqueue_kevent(struct kqueue *kq, struct thread *td, int nchanges, int nevents, 1313 struct kevent_copyops *k_ops, const struct timespec *timeout) 1314 { 1315 struct kevent keva[KQ_NEVENTS]; 1316 struct kevent *kevp, *changes; 1317 int i, n, nerrors, error; 1318 1319 if (nchanges < 0) 1320 return (EINVAL); 1321 1322 nerrors = 0; 1323 while (nchanges > 0) { 1324 n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges; 1325 error = k_ops->k_copyin(k_ops->arg, keva, n); 1326 if (error) 1327 return (error); 1328 changes = keva; 1329 for (i = 0; i < n; i++) { 1330 kevp = &changes[i]; 1331 if (!kevp->filter) 1332 continue; 1333 kevp->flags &= ~EV_SYSFLAGS; 1334 error = kqueue_register(kq, kevp, td, M_WAITOK); 1335 if (error || (kevp->flags & EV_RECEIPT)) { 1336 if (nevents == 0) 1337 return (error); 1338 kevp->flags = EV_ERROR; 1339 kevp->data = error; 1340 (void)k_ops->k_copyout(k_ops->arg, kevp, 1); 1341 nevents--; 1342 nerrors++; 1343 } 1344 } 1345 nchanges -= n; 1346 } 1347 if (nerrors) { 1348 td->td_retval[0] = nerrors; 1349 return (0); 1350 } 1351 1352 return (kqueue_scan(kq, nevents, k_ops, timeout, keva, td)); 1353 } 1354 1355 int 1356 kern_kevent_fp(struct thread *td, struct file *fp, int nchanges, int nevents, 1357 struct kevent_copyops *k_ops, const struct timespec *timeout) 1358 { 1359 struct kqueue *kq; 1360 int error; 1361 1362 error = kqueue_acquire(fp, &kq); 1363 if (error != 0) 1364 return (error); 1365 error = kqueue_kevent(kq, td, nchanges, nevents, k_ops, timeout); 1366 kqueue_release(kq, 0); 1367 return (error); 1368 } 1369 1370 /* 1371 * Performs a kevent() call on a temporarily created kqueue. This can be 1372 * used to perform one-shot polling, similar to poll() and select(). 1373 */ 1374 int 1375 kern_kevent_anonymous(struct thread *td, int nevents, 1376 struct kevent_copyops *k_ops) 1377 { 1378 struct kqueue kq = {}; 1379 int error; 1380 1381 kqueue_init(&kq); 1382 kq.kq_refcnt = 1; 1383 error = kqueue_kevent(&kq, td, nevents, nevents, k_ops, NULL); 1384 kqueue_drain(&kq, td); 1385 kqueue_destroy(&kq); 1386 return (error); 1387 } 1388 1389 int 1390 kqueue_add_filteropts(int filt, struct filterops *filtops) 1391 { 1392 int error; 1393 1394 error = 0; 1395 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) { 1396 printf( 1397 "trying to add a filterop that is out of range: %d is beyond %d\n", 1398 ~filt, EVFILT_SYSCOUNT); 1399 return EINVAL; 1400 } 1401 mtx_lock(&filterops_lock); 1402 if (sysfilt_ops[~filt].for_fop != &null_filtops && 1403 sysfilt_ops[~filt].for_fop != NULL) 1404 error = EEXIST; 1405 else { 1406 sysfilt_ops[~filt].for_fop = filtops; 1407 sysfilt_ops[~filt].for_refcnt = 0; 1408 } 1409 mtx_unlock(&filterops_lock); 1410 1411 return (error); 1412 } 1413 1414 int 1415 kqueue_del_filteropts(int filt) 1416 { 1417 int error; 1418 1419 error = 0; 1420 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1421 return EINVAL; 1422 1423 mtx_lock(&filterops_lock); 1424 if (sysfilt_ops[~filt].for_fop == &null_filtops || 1425 sysfilt_ops[~filt].for_fop == NULL) 1426 error = EINVAL; 1427 else if (sysfilt_ops[~filt].for_refcnt != 0) 1428 error = EBUSY; 1429 else { 1430 sysfilt_ops[~filt].for_fop = &null_filtops; 1431 sysfilt_ops[~filt].for_refcnt = 0; 1432 } 1433 mtx_unlock(&filterops_lock); 1434 1435 return error; 1436 } 1437 1438 static struct filterops * 1439 kqueue_fo_find(int filt) 1440 { 1441 1442 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1443 return NULL; 1444 1445 if (sysfilt_ops[~filt].for_nolock) 1446 return sysfilt_ops[~filt].for_fop; 1447 1448 mtx_lock(&filterops_lock); 1449 sysfilt_ops[~filt].for_refcnt++; 1450 if (sysfilt_ops[~filt].for_fop == NULL) 1451 sysfilt_ops[~filt].for_fop = &null_filtops; 1452 mtx_unlock(&filterops_lock); 1453 1454 return sysfilt_ops[~filt].for_fop; 1455 } 1456 1457 static void 1458 kqueue_fo_release(int filt) 1459 { 1460 1461 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1462 return; 1463 1464 if (sysfilt_ops[~filt].for_nolock) 1465 return; 1466 1467 mtx_lock(&filterops_lock); 1468 KASSERT(sysfilt_ops[~filt].for_refcnt > 0, 1469 ("filter object refcount not valid on release")); 1470 sysfilt_ops[~filt].for_refcnt--; 1471 mtx_unlock(&filterops_lock); 1472 } 1473 1474 /* 1475 * A ref to kq (obtained via kqueue_acquire) must be held. 1476 */ 1477 static int 1478 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, 1479 int mflag) 1480 { 1481 struct filterops *fops; 1482 struct file *fp; 1483 struct knote *kn, *tkn; 1484 struct knlist *knl; 1485 int error, filt, event; 1486 int haskqglobal, filedesc_unlock; 1487 1488 if ((kev->flags & (EV_ENABLE | EV_DISABLE)) == (EV_ENABLE | EV_DISABLE)) 1489 return (EINVAL); 1490 1491 fp = NULL; 1492 kn = NULL; 1493 knl = NULL; 1494 error = 0; 1495 haskqglobal = 0; 1496 filedesc_unlock = 0; 1497 1498 filt = kev->filter; 1499 fops = kqueue_fo_find(filt); 1500 if (fops == NULL) 1501 return EINVAL; 1502 1503 if (kev->flags & EV_ADD) { 1504 /* Reject an invalid flag pair early */ 1505 if (kev->flags & EV_KEEPUDATA) { 1506 tkn = NULL; 1507 error = EINVAL; 1508 goto done; 1509 } 1510 1511 /* 1512 * Prevent waiting with locks. Non-sleepable 1513 * allocation failures are handled in the loop, only 1514 * if the spare knote appears to be actually required. 1515 */ 1516 tkn = knote_alloc(mflag); 1517 } else { 1518 tkn = NULL; 1519 } 1520 1521 findkn: 1522 if (fops->f_isfd) { 1523 KASSERT(td != NULL, ("td is NULL")); 1524 if (kev->ident > INT_MAX) 1525 error = EBADF; 1526 else 1527 error = fget(td, kev->ident, &cap_event_rights, &fp); 1528 if (error) 1529 goto done; 1530 1531 if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops, 1532 kev->ident, M_NOWAIT) != 0) { 1533 /* try again */ 1534 fdrop(fp, td); 1535 fp = NULL; 1536 error = kqueue_expand(kq, fops, kev->ident, mflag); 1537 if (error) 1538 goto done; 1539 goto findkn; 1540 } 1541 1542 if (fp->f_type == DTYPE_KQUEUE) { 1543 /* 1544 * If we add some intelligence about what we are doing, 1545 * we should be able to support events on ourselves. 1546 * We need to know when we are doing this to prevent 1547 * getting both the knlist lock and the kq lock since 1548 * they are the same thing. 1549 */ 1550 if (fp->f_data == kq) { 1551 error = EINVAL; 1552 goto done; 1553 } 1554 1555 /* 1556 * Pre-lock the filedesc before the global 1557 * lock mutex, see the comment in 1558 * kqueue_close(). 1559 */ 1560 FILEDESC_XLOCK(td->td_proc->p_fd); 1561 filedesc_unlock = 1; 1562 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1563 } 1564 1565 KQ_LOCK(kq); 1566 if (kev->ident < kq->kq_knlistsize) { 1567 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link) 1568 if (kev->filter == kn->kn_filter) 1569 break; 1570 } 1571 } else { 1572 if ((kev->flags & EV_ADD) == EV_ADD) { 1573 error = kqueue_expand(kq, fops, kev->ident, mflag); 1574 if (error != 0) 1575 goto done; 1576 } 1577 1578 KQ_LOCK(kq); 1579 1580 /* 1581 * If possible, find an existing knote to use for this kevent. 1582 */ 1583 if (kev->filter == EVFILT_PROC && 1584 (kev->flags & (EV_FLAG1 | EV_FLAG2)) != 0) { 1585 /* This is an internal creation of a process tracking 1586 * note. Don't attempt to coalesce this with an 1587 * existing note. 1588 */ 1589 ; 1590 } else if (kq->kq_knhashmask != 0) { 1591 struct klist *list; 1592 1593 list = &kq->kq_knhash[ 1594 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)]; 1595 SLIST_FOREACH(kn, list, kn_link) 1596 if (kev->ident == kn->kn_id && 1597 kev->filter == kn->kn_filter) 1598 break; 1599 } 1600 } 1601 1602 /* knote is in the process of changing, wait for it to stabilize. */ 1603 if (kn != NULL && kn_in_flux(kn)) { 1604 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1605 if (filedesc_unlock) { 1606 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1607 filedesc_unlock = 0; 1608 } 1609 kq->kq_state |= KQ_FLUXWAIT; 1610 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0); 1611 if (fp != NULL) { 1612 fdrop(fp, td); 1613 fp = NULL; 1614 } 1615 goto findkn; 1616 } 1617 1618 /* 1619 * kn now contains the matching knote, or NULL if no match 1620 */ 1621 if (kn == NULL) { 1622 if (kev->flags & EV_ADD) { 1623 kn = tkn; 1624 tkn = NULL; 1625 if (kn == NULL) { 1626 KQ_UNLOCK(kq); 1627 error = ENOMEM; 1628 goto done; 1629 } 1630 kn->kn_fp = fp; 1631 kn->kn_kq = kq; 1632 kn->kn_fop = fops; 1633 /* 1634 * apply reference counts to knote structure, and 1635 * do not release it at the end of this routine. 1636 */ 1637 fops = NULL; 1638 fp = NULL; 1639 1640 kn->kn_sfflags = kev->fflags; 1641 kn->kn_sdata = kev->data; 1642 kev->fflags = 0; 1643 kev->data = 0; 1644 kn->kn_kevent = *kev; 1645 kn->kn_kevent.flags &= ~(EV_ADD | EV_DELETE | 1646 EV_ENABLE | EV_DISABLE | EV_FORCEONESHOT); 1647 kn->kn_status = KN_DETACHED; 1648 if ((kev->flags & EV_DISABLE) != 0) 1649 kn->kn_status |= KN_DISABLED; 1650 kn_enter_flux(kn); 1651 1652 error = knote_attach(kn, kq); 1653 KQ_UNLOCK(kq); 1654 if (error != 0) { 1655 tkn = kn; 1656 goto done; 1657 } 1658 1659 if ((error = kn->kn_fop->f_attach(kn)) != 0) { 1660 knote_drop_detached(kn, td); 1661 goto done; 1662 } 1663 knl = kn_list_lock(kn); 1664 goto done_ev_add; 1665 } else { 1666 /* No matching knote and the EV_ADD flag is not set. */ 1667 KQ_UNLOCK(kq); 1668 error = ENOENT; 1669 goto done; 1670 } 1671 } 1672 1673 if (kev->flags & EV_DELETE) { 1674 kn_enter_flux(kn); 1675 KQ_UNLOCK(kq); 1676 knote_drop(kn, td); 1677 goto done; 1678 } 1679 1680 if (kev->flags & EV_FORCEONESHOT) { 1681 kn->kn_flags |= EV_ONESHOT; 1682 KNOTE_ACTIVATE(kn, 1); 1683 } 1684 1685 if ((kev->flags & EV_ENABLE) != 0) 1686 kn->kn_status &= ~KN_DISABLED; 1687 else if ((kev->flags & EV_DISABLE) != 0) 1688 kn->kn_status |= KN_DISABLED; 1689 1690 /* 1691 * The user may change some filter values after the initial EV_ADD, 1692 * but doing so will not reset any filter which has already been 1693 * triggered. 1694 */ 1695 kn->kn_status |= KN_SCAN; 1696 kn_enter_flux(kn); 1697 KQ_UNLOCK(kq); 1698 knl = kn_list_lock(kn); 1699 if ((kev->flags & EV_KEEPUDATA) == 0) 1700 kn->kn_kevent.udata = kev->udata; 1701 if (!fops->f_isfd && fops->f_touch != NULL) { 1702 fops->f_touch(kn, kev, EVENT_REGISTER); 1703 } else { 1704 kn->kn_sfflags = kev->fflags; 1705 kn->kn_sdata = kev->data; 1706 } 1707 1708 done_ev_add: 1709 /* 1710 * We can get here with kn->kn_knlist == NULL. This can happen when 1711 * the initial attach event decides that the event is "completed" 1712 * already, e.g., filt_procattach() is called on a zombie process. It 1713 * will call filt_proc() which will remove it from the list, and NULL 1714 * kn_knlist. 1715 * 1716 * KN_DISABLED will be stable while the knote is in flux, so the 1717 * unlocked read will not race with an update. 1718 */ 1719 if ((kn->kn_status & KN_DISABLED) == 0) 1720 event = kn->kn_fop->f_event(kn, 0); 1721 else 1722 event = 0; 1723 1724 KQ_LOCK(kq); 1725 if (event) 1726 kn->kn_status |= KN_ACTIVE; 1727 if ((kn->kn_status & (KN_ACTIVE | KN_DISABLED | KN_QUEUED)) == 1728 KN_ACTIVE) 1729 knote_enqueue(kn); 1730 kn->kn_status &= ~KN_SCAN; 1731 kn_leave_flux(kn); 1732 kn_list_unlock(knl); 1733 KQ_UNLOCK_FLUX(kq); 1734 1735 done: 1736 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1737 if (filedesc_unlock) 1738 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1739 if (fp != NULL) 1740 fdrop(fp, td); 1741 knote_free(tkn); 1742 if (fops != NULL) 1743 kqueue_fo_release(filt); 1744 return (error); 1745 } 1746 1747 static int 1748 kqueue_acquire(struct file *fp, struct kqueue **kqp) 1749 { 1750 int error; 1751 struct kqueue *kq; 1752 1753 error = 0; 1754 1755 kq = fp->f_data; 1756 if (fp->f_type != DTYPE_KQUEUE || kq == NULL) 1757 return (EBADF); 1758 *kqp = kq; 1759 KQ_LOCK(kq); 1760 if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) { 1761 KQ_UNLOCK(kq); 1762 return (EBADF); 1763 } 1764 kq->kq_refcnt++; 1765 KQ_UNLOCK(kq); 1766 1767 return error; 1768 } 1769 1770 static void 1771 kqueue_release(struct kqueue *kq, int locked) 1772 { 1773 if (locked) 1774 KQ_OWNED(kq); 1775 else 1776 KQ_LOCK(kq); 1777 kq->kq_refcnt--; 1778 if (kq->kq_refcnt == 1) 1779 wakeup(&kq->kq_refcnt); 1780 if (!locked) 1781 KQ_UNLOCK(kq); 1782 } 1783 1784 void 1785 kqueue_drain_schedtask(void) 1786 { 1787 taskqueue_quiesce(taskqueue_kqueue_ctx); 1788 } 1789 1790 static void 1791 kqueue_schedtask(struct kqueue *kq) 1792 { 1793 struct thread *td; 1794 1795 KQ_OWNED(kq); 1796 KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN), 1797 ("scheduling kqueue task while draining")); 1798 1799 if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) { 1800 taskqueue_enqueue(taskqueue_kqueue_ctx, &kq->kq_task); 1801 kq->kq_state |= KQ_TASKSCHED; 1802 td = curthread; 1803 thread_lock(td); 1804 td->td_flags |= TDF_ASTPENDING | TDF_KQTICKLED; 1805 thread_unlock(td); 1806 } 1807 } 1808 1809 /* 1810 * Expand the kq to make sure we have storage for fops/ident pair. 1811 * 1812 * Return 0 on success (or no work necessary), return errno on failure. 1813 */ 1814 static int 1815 kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident, 1816 int mflag) 1817 { 1818 struct klist *list, *tmp_knhash, *to_free; 1819 u_long tmp_knhashmask; 1820 int error, fd, size; 1821 1822 KQ_NOTOWNED(kq); 1823 1824 error = 0; 1825 to_free = NULL; 1826 if (fops->f_isfd) { 1827 fd = ident; 1828 if (kq->kq_knlistsize <= fd) { 1829 size = kq->kq_knlistsize; 1830 while (size <= fd) 1831 size += KQEXTENT; 1832 list = malloc(size * sizeof(*list), M_KQUEUE, mflag); 1833 if (list == NULL) 1834 return ENOMEM; 1835 KQ_LOCK(kq); 1836 if ((kq->kq_state & KQ_CLOSING) != 0) { 1837 to_free = list; 1838 error = EBADF; 1839 } else if (kq->kq_knlistsize > fd) { 1840 to_free = list; 1841 } else { 1842 if (kq->kq_knlist != NULL) { 1843 bcopy(kq->kq_knlist, list, 1844 kq->kq_knlistsize * sizeof(*list)); 1845 to_free = kq->kq_knlist; 1846 kq->kq_knlist = NULL; 1847 } 1848 bzero((caddr_t)list + 1849 kq->kq_knlistsize * sizeof(*list), 1850 (size - kq->kq_knlistsize) * sizeof(*list)); 1851 kq->kq_knlistsize = size; 1852 kq->kq_knlist = list; 1853 } 1854 KQ_UNLOCK(kq); 1855 } 1856 } else { 1857 if (kq->kq_knhashmask == 0) { 1858 tmp_knhash = hashinit_flags(KN_HASHSIZE, M_KQUEUE, 1859 &tmp_knhashmask, (mflag & M_WAITOK) != 0 ? 1860 HASH_WAITOK : HASH_NOWAIT); 1861 if (tmp_knhash == NULL) 1862 return (ENOMEM); 1863 KQ_LOCK(kq); 1864 if ((kq->kq_state & KQ_CLOSING) != 0) { 1865 to_free = tmp_knhash; 1866 error = EBADF; 1867 } else if (kq->kq_knhashmask == 0) { 1868 kq->kq_knhash = tmp_knhash; 1869 kq->kq_knhashmask = tmp_knhashmask; 1870 } else { 1871 to_free = tmp_knhash; 1872 } 1873 KQ_UNLOCK(kq); 1874 } 1875 } 1876 free(to_free, M_KQUEUE); 1877 1878 KQ_NOTOWNED(kq); 1879 return (error); 1880 } 1881 1882 static void 1883 kqueue_task(void *arg, int pending) 1884 { 1885 struct kqueue *kq; 1886 int haskqglobal; 1887 1888 haskqglobal = 0; 1889 kq = arg; 1890 1891 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1892 KQ_LOCK(kq); 1893 1894 KNOTE_LOCKED(&kq->kq_sel.si_note, 0); 1895 1896 kq->kq_state &= ~KQ_TASKSCHED; 1897 if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) { 1898 wakeup(&kq->kq_state); 1899 } 1900 KQ_UNLOCK(kq); 1901 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1902 } 1903 1904 /* 1905 * Scan, update kn_data (if not ONESHOT), and copyout triggered events. 1906 * We treat KN_MARKER knotes as if they are in flux. 1907 */ 1908 static int 1909 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops, 1910 const struct timespec *tsp, struct kevent *keva, struct thread *td) 1911 { 1912 struct kevent *kevp; 1913 struct knote *kn, *marker; 1914 struct knlist *knl; 1915 sbintime_t asbt, rsbt; 1916 int count, error, haskqglobal, influx, nkev, touch; 1917 1918 count = maxevents; 1919 nkev = 0; 1920 error = 0; 1921 haskqglobal = 0; 1922 1923 if (maxevents == 0) 1924 goto done_nl; 1925 if (maxevents < 0) { 1926 error = EINVAL; 1927 goto done_nl; 1928 } 1929 1930 rsbt = 0; 1931 if (tsp != NULL) { 1932 if (tsp->tv_sec < 0 || tsp->tv_nsec < 0 || 1933 tsp->tv_nsec >= 1000000000) { 1934 error = EINVAL; 1935 goto done_nl; 1936 } 1937 if (timespecisset(tsp)) { 1938 if (tsp->tv_sec <= INT32_MAX) { 1939 rsbt = tstosbt(*tsp); 1940 if (TIMESEL(&asbt, rsbt)) 1941 asbt += tc_tick_sbt; 1942 if (asbt <= SBT_MAX - rsbt) 1943 asbt += rsbt; 1944 else 1945 asbt = 0; 1946 rsbt >>= tc_precexp; 1947 } else 1948 asbt = 0; 1949 } else 1950 asbt = -1; 1951 } else 1952 asbt = 0; 1953 marker = knote_alloc(M_WAITOK); 1954 marker->kn_status = KN_MARKER; 1955 KQ_LOCK(kq); 1956 1957 retry: 1958 kevp = keva; 1959 if (kq->kq_count == 0) { 1960 if (asbt == -1) { 1961 error = EWOULDBLOCK; 1962 } else { 1963 kq->kq_state |= KQ_SLEEP; 1964 error = msleep_sbt(kq, &kq->kq_lock, PSOCK | PCATCH, 1965 "kqread", asbt, rsbt, C_ABSOLUTE); 1966 } 1967 if (error == 0) 1968 goto retry; 1969 /* don't restart after signals... */ 1970 if (error == ERESTART) 1971 error = EINTR; 1972 else if (error == EWOULDBLOCK) 1973 error = 0; 1974 goto done; 1975 } 1976 1977 TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); 1978 influx = 0; 1979 while (count) { 1980 KQ_OWNED(kq); 1981 kn = TAILQ_FIRST(&kq->kq_head); 1982 1983 if ((kn->kn_status == KN_MARKER && kn != marker) || 1984 kn_in_flux(kn)) { 1985 if (influx) { 1986 influx = 0; 1987 KQ_FLUX_WAKEUP(kq); 1988 } 1989 kq->kq_state |= KQ_FLUXWAIT; 1990 error = msleep(kq, &kq->kq_lock, PSOCK, 1991 "kqflxwt", 0); 1992 continue; 1993 } 1994 1995 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1996 if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) { 1997 kn->kn_status &= ~KN_QUEUED; 1998 kq->kq_count--; 1999 continue; 2000 } 2001 if (kn == marker) { 2002 KQ_FLUX_WAKEUP(kq); 2003 if (count == maxevents) 2004 goto retry; 2005 goto done; 2006 } 2007 KASSERT(!kn_in_flux(kn), 2008 ("knote %p is unexpectedly in flux", kn)); 2009 2010 if ((kn->kn_flags & EV_DROP) == EV_DROP) { 2011 kn->kn_status &= ~KN_QUEUED; 2012 kn_enter_flux(kn); 2013 kq->kq_count--; 2014 KQ_UNLOCK(kq); 2015 /* 2016 * We don't need to lock the list since we've 2017 * marked it as in flux. 2018 */ 2019 knote_drop(kn, td); 2020 KQ_LOCK(kq); 2021 continue; 2022 } else if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) { 2023 kn->kn_status &= ~KN_QUEUED; 2024 kn_enter_flux(kn); 2025 kq->kq_count--; 2026 KQ_UNLOCK(kq); 2027 /* 2028 * We don't need to lock the list since we've 2029 * marked the knote as being in flux. 2030 */ 2031 *kevp = kn->kn_kevent; 2032 knote_drop(kn, td); 2033 KQ_LOCK(kq); 2034 kn = NULL; 2035 } else { 2036 kn->kn_status |= KN_SCAN; 2037 kn_enter_flux(kn); 2038 KQ_UNLOCK(kq); 2039 if ((kn->kn_status & KN_KQUEUE) == KN_KQUEUE) 2040 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 2041 knl = kn_list_lock(kn); 2042 if (kn->kn_fop->f_event(kn, 0) == 0) { 2043 KQ_LOCK(kq); 2044 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 2045 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE | 2046 KN_SCAN); 2047 kn_leave_flux(kn); 2048 kq->kq_count--; 2049 kn_list_unlock(knl); 2050 influx = 1; 2051 continue; 2052 } 2053 touch = (!kn->kn_fop->f_isfd && 2054 kn->kn_fop->f_touch != NULL); 2055 if (touch) 2056 kn->kn_fop->f_touch(kn, kevp, EVENT_PROCESS); 2057 else 2058 *kevp = kn->kn_kevent; 2059 KQ_LOCK(kq); 2060 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 2061 if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) { 2062 /* 2063 * Manually clear knotes who weren't 2064 * 'touch'ed. 2065 */ 2066 if (touch == 0 && kn->kn_flags & EV_CLEAR) { 2067 kn->kn_data = 0; 2068 kn->kn_fflags = 0; 2069 } 2070 if (kn->kn_flags & EV_DISPATCH) 2071 kn->kn_status |= KN_DISABLED; 2072 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 2073 kq->kq_count--; 2074 } else 2075 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2076 2077 kn->kn_status &= ~KN_SCAN; 2078 kn_leave_flux(kn); 2079 kn_list_unlock(knl); 2080 influx = 1; 2081 } 2082 2083 /* we are returning a copy to the user */ 2084 kevp++; 2085 nkev++; 2086 count--; 2087 2088 if (nkev == KQ_NEVENTS) { 2089 influx = 0; 2090 KQ_UNLOCK_FLUX(kq); 2091 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 2092 nkev = 0; 2093 kevp = keva; 2094 KQ_LOCK(kq); 2095 if (error) 2096 break; 2097 } 2098 } 2099 TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); 2100 done: 2101 KQ_OWNED(kq); 2102 KQ_UNLOCK_FLUX(kq); 2103 knote_free(marker); 2104 done_nl: 2105 KQ_NOTOWNED(kq); 2106 if (nkev != 0) 2107 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 2108 td->td_retval[0] = maxevents - count; 2109 return (error); 2110 } 2111 2112 /*ARGSUSED*/ 2113 static int 2114 kqueue_ioctl(struct file *fp, u_long cmd, void *data, 2115 struct ucred *active_cred, struct thread *td) 2116 { 2117 /* 2118 * Enabling sigio causes two major problems: 2119 * 1) infinite recursion: 2120 * Synopsys: kevent is being used to track signals and have FIOASYNC 2121 * set. On receipt of a signal this will cause a kqueue to recurse 2122 * into itself over and over. Sending the sigio causes the kqueue 2123 * to become ready, which in turn posts sigio again, forever. 2124 * Solution: this can be solved by setting a flag in the kqueue that 2125 * we have a SIGIO in progress. 2126 * 2) locking problems: 2127 * Synopsys: Kqueue is a leaf subsystem, but adding signalling puts 2128 * us above the proc and pgrp locks. 2129 * Solution: Post a signal using an async mechanism, being sure to 2130 * record a generation count in the delivery so that we do not deliver 2131 * a signal to the wrong process. 2132 * 2133 * Note, these two mechanisms are somewhat mutually exclusive! 2134 */ 2135 #if 0 2136 struct kqueue *kq; 2137 2138 kq = fp->f_data; 2139 switch (cmd) { 2140 case FIOASYNC: 2141 if (*(int *)data) { 2142 kq->kq_state |= KQ_ASYNC; 2143 } else { 2144 kq->kq_state &= ~KQ_ASYNC; 2145 } 2146 return (0); 2147 2148 case FIOSETOWN: 2149 return (fsetown(*(int *)data, &kq->kq_sigio)); 2150 2151 case FIOGETOWN: 2152 *(int *)data = fgetown(&kq->kq_sigio); 2153 return (0); 2154 } 2155 #endif 2156 2157 return (ENOTTY); 2158 } 2159 2160 /*ARGSUSED*/ 2161 static int 2162 kqueue_poll(struct file *fp, int events, struct ucred *active_cred, 2163 struct thread *td) 2164 { 2165 struct kqueue *kq; 2166 int revents = 0; 2167 int error; 2168 2169 if ((error = kqueue_acquire(fp, &kq))) 2170 return POLLERR; 2171 2172 KQ_LOCK(kq); 2173 if (events & (POLLIN | POLLRDNORM)) { 2174 if (kq->kq_count) { 2175 revents |= events & (POLLIN | POLLRDNORM); 2176 } else { 2177 selrecord(td, &kq->kq_sel); 2178 if (SEL_WAITING(&kq->kq_sel)) 2179 kq->kq_state |= KQ_SEL; 2180 } 2181 } 2182 kqueue_release(kq, 1); 2183 KQ_UNLOCK(kq); 2184 return (revents); 2185 } 2186 2187 /*ARGSUSED*/ 2188 static int 2189 kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred, 2190 struct thread *td) 2191 { 2192 2193 bzero((void *)st, sizeof *st); 2194 /* 2195 * We no longer return kq_count because the unlocked value is useless. 2196 * If you spent all this time getting the count, why not spend your 2197 * syscall better by calling kevent? 2198 * 2199 * XXX - This is needed for libc_r. 2200 */ 2201 st->st_mode = S_IFIFO; 2202 return (0); 2203 } 2204 2205 static void 2206 kqueue_drain(struct kqueue *kq, struct thread *td) 2207 { 2208 struct knote *kn; 2209 int i; 2210 2211 KQ_LOCK(kq); 2212 2213 KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING, 2214 ("kqueue already closing")); 2215 kq->kq_state |= KQ_CLOSING; 2216 if (kq->kq_refcnt > 1) 2217 msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0); 2218 2219 KASSERT(kq->kq_refcnt == 1, ("other refs are out there!")); 2220 2221 KASSERT(knlist_empty(&kq->kq_sel.si_note), 2222 ("kqueue's knlist not empty")); 2223 2224 for (i = 0; i < kq->kq_knlistsize; i++) { 2225 while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) { 2226 if (kn_in_flux(kn)) { 2227 kq->kq_state |= KQ_FLUXWAIT; 2228 msleep(kq, &kq->kq_lock, PSOCK, "kqclo1", 0); 2229 continue; 2230 } 2231 kn_enter_flux(kn); 2232 KQ_UNLOCK(kq); 2233 knote_drop(kn, td); 2234 KQ_LOCK(kq); 2235 } 2236 } 2237 if (kq->kq_knhashmask != 0) { 2238 for (i = 0; i <= kq->kq_knhashmask; i++) { 2239 while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) { 2240 if (kn_in_flux(kn)) { 2241 kq->kq_state |= KQ_FLUXWAIT; 2242 msleep(kq, &kq->kq_lock, PSOCK, 2243 "kqclo2", 0); 2244 continue; 2245 } 2246 kn_enter_flux(kn); 2247 KQ_UNLOCK(kq); 2248 knote_drop(kn, td); 2249 KQ_LOCK(kq); 2250 } 2251 } 2252 } 2253 2254 if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) { 2255 kq->kq_state |= KQ_TASKDRAIN; 2256 msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0); 2257 } 2258 2259 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2260 selwakeuppri(&kq->kq_sel, PSOCK); 2261 if (!SEL_WAITING(&kq->kq_sel)) 2262 kq->kq_state &= ~KQ_SEL; 2263 } 2264 2265 KQ_UNLOCK(kq); 2266 } 2267 2268 static void 2269 kqueue_destroy(struct kqueue *kq) 2270 { 2271 2272 KASSERT(kq->kq_fdp == NULL, 2273 ("kqueue still attached to a file descriptor")); 2274 seldrain(&kq->kq_sel); 2275 knlist_destroy(&kq->kq_sel.si_note); 2276 mtx_destroy(&kq->kq_lock); 2277 2278 if (kq->kq_knhash != NULL) 2279 free(kq->kq_knhash, M_KQUEUE); 2280 if (kq->kq_knlist != NULL) 2281 free(kq->kq_knlist, M_KQUEUE); 2282 2283 funsetown(&kq->kq_sigio); 2284 } 2285 2286 /*ARGSUSED*/ 2287 static int 2288 kqueue_close(struct file *fp, struct thread *td) 2289 { 2290 struct kqueue *kq = fp->f_data; 2291 struct filedesc *fdp; 2292 int error; 2293 int filedesc_unlock; 2294 2295 if ((error = kqueue_acquire(fp, &kq))) 2296 return error; 2297 kqueue_drain(kq, td); 2298 2299 /* 2300 * We could be called due to the knote_drop() doing fdrop(), 2301 * called from kqueue_register(). In this case the global 2302 * lock is owned, and filedesc sx is locked before, to not 2303 * take the sleepable lock after non-sleepable. 2304 */ 2305 fdp = kq->kq_fdp; 2306 kq->kq_fdp = NULL; 2307 if (!sx_xlocked(FILEDESC_LOCK(fdp))) { 2308 FILEDESC_XLOCK(fdp); 2309 filedesc_unlock = 1; 2310 } else 2311 filedesc_unlock = 0; 2312 TAILQ_REMOVE(&fdp->fd_kqlist, kq, kq_list); 2313 if (filedesc_unlock) 2314 FILEDESC_XUNLOCK(fdp); 2315 2316 kqueue_destroy(kq); 2317 chgkqcnt(kq->kq_cred->cr_ruidinfo, -1, 0); 2318 crfree(kq->kq_cred); 2319 free(kq, M_KQUEUE); 2320 fp->f_data = NULL; 2321 2322 return (0); 2323 } 2324 2325 static int 2326 kqueue_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 2327 { 2328 2329 kif->kf_type = KF_TYPE_KQUEUE; 2330 return (0); 2331 } 2332 2333 static void 2334 kqueue_wakeup(struct kqueue *kq) 2335 { 2336 KQ_OWNED(kq); 2337 2338 if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) { 2339 kq->kq_state &= ~KQ_SLEEP; 2340 wakeup(kq); 2341 } 2342 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2343 selwakeuppri(&kq->kq_sel, PSOCK); 2344 if (!SEL_WAITING(&kq->kq_sel)) 2345 kq->kq_state &= ~KQ_SEL; 2346 } 2347 if (!knlist_empty(&kq->kq_sel.si_note)) 2348 kqueue_schedtask(kq); 2349 if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) { 2350 pgsigio(&kq->kq_sigio, SIGIO, 0); 2351 } 2352 } 2353 2354 /* 2355 * Walk down a list of knotes, activating them if their event has triggered. 2356 * 2357 * There is a possibility to optimize in the case of one kq watching another. 2358 * Instead of scheduling a task to wake it up, you could pass enough state 2359 * down the chain to make up the parent kqueue. Make this code functional 2360 * first. 2361 */ 2362 void 2363 knote(struct knlist *list, long hint, int lockflags) 2364 { 2365 struct kqueue *kq; 2366 struct knote *kn, *tkn; 2367 int error; 2368 2369 if (list == NULL) 2370 return; 2371 2372 KNL_ASSERT_LOCK(list, lockflags & KNF_LISTLOCKED); 2373 2374 if ((lockflags & KNF_LISTLOCKED) == 0) 2375 list->kl_lock(list->kl_lockarg); 2376 2377 /* 2378 * If we unlock the list lock (and enter influx), we can 2379 * eliminate the kqueue scheduling, but this will introduce 2380 * four lock/unlock's for each knote to test. Also, marker 2381 * would be needed to keep iteration position, since filters 2382 * or other threads could remove events. 2383 */ 2384 SLIST_FOREACH_SAFE(kn, &list->kl_list, kn_selnext, tkn) { 2385 kq = kn->kn_kq; 2386 KQ_LOCK(kq); 2387 if (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0) { 2388 /* 2389 * Do not process the influx notes, except for 2390 * the influx coming from the kq unlock in the 2391 * kqueue_scan(). In the later case, we do 2392 * not interfere with the scan, since the code 2393 * fragment in kqueue_scan() locks the knlist, 2394 * and cannot proceed until we finished. 2395 */ 2396 KQ_UNLOCK(kq); 2397 } else if ((lockflags & KNF_NOKQLOCK) != 0) { 2398 kn_enter_flux(kn); 2399 KQ_UNLOCK(kq); 2400 error = kn->kn_fop->f_event(kn, hint); 2401 KQ_LOCK(kq); 2402 kn_leave_flux(kn); 2403 if (error) 2404 KNOTE_ACTIVATE(kn, 1); 2405 KQ_UNLOCK_FLUX(kq); 2406 } else { 2407 if (kn->kn_fop->f_event(kn, hint)) 2408 KNOTE_ACTIVATE(kn, 1); 2409 KQ_UNLOCK(kq); 2410 } 2411 } 2412 if ((lockflags & KNF_LISTLOCKED) == 0) 2413 list->kl_unlock(list->kl_lockarg); 2414 } 2415 2416 /* 2417 * add a knote to a knlist 2418 */ 2419 void 2420 knlist_add(struct knlist *knl, struct knote *kn, int islocked) 2421 { 2422 2423 KNL_ASSERT_LOCK(knl, islocked); 2424 KQ_NOTOWNED(kn->kn_kq); 2425 KASSERT(kn_in_flux(kn), ("knote %p not in flux", kn)); 2426 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2427 ("knote %p was not detached", kn)); 2428 if (!islocked) 2429 knl->kl_lock(knl->kl_lockarg); 2430 SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext); 2431 if (!islocked) 2432 knl->kl_unlock(knl->kl_lockarg); 2433 KQ_LOCK(kn->kn_kq); 2434 kn->kn_knlist = knl; 2435 kn->kn_status &= ~KN_DETACHED; 2436 KQ_UNLOCK(kn->kn_kq); 2437 } 2438 2439 static void 2440 knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked, 2441 int kqislocked) 2442 { 2443 2444 KASSERT(!kqislocked || knlislocked, ("kq locked w/o knl locked")); 2445 KNL_ASSERT_LOCK(knl, knlislocked); 2446 mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED); 2447 KASSERT(kqislocked || kn_in_flux(kn), ("knote %p not in flux", kn)); 2448 KASSERT((kn->kn_status & KN_DETACHED) == 0, 2449 ("knote %p was already detached", kn)); 2450 if (!knlislocked) 2451 knl->kl_lock(knl->kl_lockarg); 2452 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext); 2453 kn->kn_knlist = NULL; 2454 if (!knlislocked) 2455 kn_list_unlock(knl); 2456 if (!kqislocked) 2457 KQ_LOCK(kn->kn_kq); 2458 kn->kn_status |= KN_DETACHED; 2459 if (!kqislocked) 2460 KQ_UNLOCK(kn->kn_kq); 2461 } 2462 2463 /* 2464 * remove knote from the specified knlist 2465 */ 2466 void 2467 knlist_remove(struct knlist *knl, struct knote *kn, int islocked) 2468 { 2469 2470 knlist_remove_kq(knl, kn, islocked, 0); 2471 } 2472 2473 int 2474 knlist_empty(struct knlist *knl) 2475 { 2476 2477 KNL_ASSERT_LOCKED(knl); 2478 return (SLIST_EMPTY(&knl->kl_list)); 2479 } 2480 2481 static struct mtx knlist_lock; 2482 MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects", 2483 MTX_DEF); 2484 static void knlist_mtx_lock(void *arg); 2485 static void knlist_mtx_unlock(void *arg); 2486 2487 static void 2488 knlist_mtx_lock(void *arg) 2489 { 2490 2491 mtx_lock((struct mtx *)arg); 2492 } 2493 2494 static void 2495 knlist_mtx_unlock(void *arg) 2496 { 2497 2498 mtx_unlock((struct mtx *)arg); 2499 } 2500 2501 static void 2502 knlist_mtx_assert_lock(void *arg, int what) 2503 { 2504 2505 if (what == LA_LOCKED) 2506 mtx_assert((struct mtx *)arg, MA_OWNED); 2507 else 2508 mtx_assert((struct mtx *)arg, MA_NOTOWNED); 2509 } 2510 2511 static void 2512 knlist_rw_rlock(void *arg) 2513 { 2514 2515 rw_rlock((struct rwlock *)arg); 2516 } 2517 2518 static void 2519 knlist_rw_runlock(void *arg) 2520 { 2521 2522 rw_runlock((struct rwlock *)arg); 2523 } 2524 2525 static void 2526 knlist_rw_assert_lock(void *arg, int what) 2527 { 2528 2529 if (what == LA_LOCKED) 2530 rw_assert((struct rwlock *)arg, RA_LOCKED); 2531 else 2532 rw_assert((struct rwlock *)arg, RA_UNLOCKED); 2533 } 2534 2535 void 2536 knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *), 2537 void (*kl_unlock)(void *), 2538 void (*kl_assert_lock)(void *, int)) 2539 { 2540 2541 if (lock == NULL) 2542 knl->kl_lockarg = &knlist_lock; 2543 else 2544 knl->kl_lockarg = lock; 2545 2546 if (kl_lock == NULL) 2547 knl->kl_lock = knlist_mtx_lock; 2548 else 2549 knl->kl_lock = kl_lock; 2550 if (kl_unlock == NULL) 2551 knl->kl_unlock = knlist_mtx_unlock; 2552 else 2553 knl->kl_unlock = kl_unlock; 2554 if (kl_assert_lock == NULL) 2555 knl->kl_assert_lock = knlist_mtx_assert_lock; 2556 else 2557 knl->kl_assert_lock = kl_assert_lock; 2558 2559 knl->kl_autodestroy = 0; 2560 SLIST_INIT(&knl->kl_list); 2561 } 2562 2563 void 2564 knlist_init_mtx(struct knlist *knl, struct mtx *lock) 2565 { 2566 2567 knlist_init(knl, lock, NULL, NULL, NULL); 2568 } 2569 2570 struct knlist * 2571 knlist_alloc(struct mtx *lock) 2572 { 2573 struct knlist *knl; 2574 2575 knl = malloc(sizeof(struct knlist), M_KQUEUE, M_WAITOK); 2576 knlist_init_mtx(knl, lock); 2577 return (knl); 2578 } 2579 2580 void 2581 knlist_init_rw_reader(struct knlist *knl, struct rwlock *lock) 2582 { 2583 2584 knlist_init(knl, lock, knlist_rw_rlock, knlist_rw_runlock, 2585 knlist_rw_assert_lock); 2586 } 2587 2588 void 2589 knlist_destroy(struct knlist *knl) 2590 { 2591 2592 KASSERT(KNLIST_EMPTY(knl), 2593 ("destroying knlist %p with knotes on it", knl)); 2594 } 2595 2596 void 2597 knlist_detach(struct knlist *knl) 2598 { 2599 2600 KNL_ASSERT_LOCKED(knl); 2601 knl->kl_autodestroy = 1; 2602 if (knlist_empty(knl)) { 2603 knlist_destroy(knl); 2604 free(knl, M_KQUEUE); 2605 } 2606 } 2607 2608 /* 2609 * Even if we are locked, we may need to drop the lock to allow any influx 2610 * knotes time to "settle". 2611 */ 2612 void 2613 knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn) 2614 { 2615 struct knote *kn, *kn2; 2616 struct kqueue *kq; 2617 2618 KASSERT(!knl->kl_autodestroy, ("cleardel for autodestroy %p", knl)); 2619 if (islocked) 2620 KNL_ASSERT_LOCKED(knl); 2621 else { 2622 KNL_ASSERT_UNLOCKED(knl); 2623 again: /* need to reacquire lock since we have dropped it */ 2624 knl->kl_lock(knl->kl_lockarg); 2625 } 2626 2627 SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) { 2628 kq = kn->kn_kq; 2629 KQ_LOCK(kq); 2630 if (kn_in_flux(kn)) { 2631 KQ_UNLOCK(kq); 2632 continue; 2633 } 2634 knlist_remove_kq(knl, kn, 1, 1); 2635 if (killkn) { 2636 kn_enter_flux(kn); 2637 KQ_UNLOCK(kq); 2638 knote_drop_detached(kn, td); 2639 } else { 2640 /* Make sure cleared knotes disappear soon */ 2641 kn->kn_flags |= EV_EOF | EV_ONESHOT; 2642 KQ_UNLOCK(kq); 2643 } 2644 kq = NULL; 2645 } 2646 2647 if (!SLIST_EMPTY(&knl->kl_list)) { 2648 /* there are still in flux knotes remaining */ 2649 kn = SLIST_FIRST(&knl->kl_list); 2650 kq = kn->kn_kq; 2651 KQ_LOCK(kq); 2652 KASSERT(kn_in_flux(kn), ("knote removed w/o list lock")); 2653 knl->kl_unlock(knl->kl_lockarg); 2654 kq->kq_state |= KQ_FLUXWAIT; 2655 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0); 2656 kq = NULL; 2657 goto again; 2658 } 2659 2660 if (islocked) 2661 KNL_ASSERT_LOCKED(knl); 2662 else { 2663 knl->kl_unlock(knl->kl_lockarg); 2664 KNL_ASSERT_UNLOCKED(knl); 2665 } 2666 } 2667 2668 /* 2669 * Remove all knotes referencing a specified fd must be called with FILEDESC 2670 * lock. This prevents a race where a new fd comes along and occupies the 2671 * entry and we attach a knote to the fd. 2672 */ 2673 void 2674 knote_fdclose(struct thread *td, int fd) 2675 { 2676 struct filedesc *fdp = td->td_proc->p_fd; 2677 struct kqueue *kq; 2678 struct knote *kn; 2679 int influx; 2680 2681 FILEDESC_XLOCK_ASSERT(fdp); 2682 2683 /* 2684 * We shouldn't have to worry about new kevents appearing on fd 2685 * since filedesc is locked. 2686 */ 2687 TAILQ_FOREACH(kq, &fdp->fd_kqlist, kq_list) { 2688 KQ_LOCK(kq); 2689 2690 again: 2691 influx = 0; 2692 while (kq->kq_knlistsize > fd && 2693 (kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) { 2694 if (kn_in_flux(kn)) { 2695 /* someone else might be waiting on our knote */ 2696 if (influx) 2697 wakeup(kq); 2698 kq->kq_state |= KQ_FLUXWAIT; 2699 msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0); 2700 goto again; 2701 } 2702 kn_enter_flux(kn); 2703 KQ_UNLOCK(kq); 2704 influx = 1; 2705 knote_drop(kn, td); 2706 KQ_LOCK(kq); 2707 } 2708 KQ_UNLOCK_FLUX(kq); 2709 } 2710 } 2711 2712 static int 2713 knote_attach(struct knote *kn, struct kqueue *kq) 2714 { 2715 struct klist *list; 2716 2717 KASSERT(kn_in_flux(kn), ("knote %p not marked influx", kn)); 2718 KQ_OWNED(kq); 2719 2720 if ((kq->kq_state & KQ_CLOSING) != 0) 2721 return (EBADF); 2722 if (kn->kn_fop->f_isfd) { 2723 if (kn->kn_id >= kq->kq_knlistsize) 2724 return (ENOMEM); 2725 list = &kq->kq_knlist[kn->kn_id]; 2726 } else { 2727 if (kq->kq_knhash == NULL) 2728 return (ENOMEM); 2729 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2730 } 2731 SLIST_INSERT_HEAD(list, kn, kn_link); 2732 return (0); 2733 } 2734 2735 static void 2736 knote_drop(struct knote *kn, struct thread *td) 2737 { 2738 2739 if ((kn->kn_status & KN_DETACHED) == 0) 2740 kn->kn_fop->f_detach(kn); 2741 knote_drop_detached(kn, td); 2742 } 2743 2744 static void 2745 knote_drop_detached(struct knote *kn, struct thread *td) 2746 { 2747 struct kqueue *kq; 2748 struct klist *list; 2749 2750 kq = kn->kn_kq; 2751 2752 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2753 ("knote %p still attached", kn)); 2754 KQ_NOTOWNED(kq); 2755 2756 KQ_LOCK(kq); 2757 KASSERT(kn->kn_influx == 1, 2758 ("knote_drop called on %p with influx %d", kn, kn->kn_influx)); 2759 2760 if (kn->kn_fop->f_isfd) 2761 list = &kq->kq_knlist[kn->kn_id]; 2762 else 2763 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2764 2765 if (!SLIST_EMPTY(list)) 2766 SLIST_REMOVE(list, kn, knote, kn_link); 2767 if (kn->kn_status & KN_QUEUED) 2768 knote_dequeue(kn); 2769 KQ_UNLOCK_FLUX(kq); 2770 2771 if (kn->kn_fop->f_isfd) { 2772 fdrop(kn->kn_fp, td); 2773 kn->kn_fp = NULL; 2774 } 2775 kqueue_fo_release(kn->kn_kevent.filter); 2776 kn->kn_fop = NULL; 2777 knote_free(kn); 2778 } 2779 2780 static void 2781 knote_enqueue(struct knote *kn) 2782 { 2783 struct kqueue *kq = kn->kn_kq; 2784 2785 KQ_OWNED(kn->kn_kq); 2786 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 2787 2788 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2789 kn->kn_status |= KN_QUEUED; 2790 kq->kq_count++; 2791 kqueue_wakeup(kq); 2792 } 2793 2794 static void 2795 knote_dequeue(struct knote *kn) 2796 { 2797 struct kqueue *kq = kn->kn_kq; 2798 2799 KQ_OWNED(kn->kn_kq); 2800 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 2801 2802 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 2803 kn->kn_status &= ~KN_QUEUED; 2804 kq->kq_count--; 2805 } 2806 2807 static void 2808 knote_init(void) 2809 { 2810 2811 knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL, 2812 NULL, NULL, UMA_ALIGN_PTR, 0); 2813 } 2814 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL); 2815 2816 static struct knote * 2817 knote_alloc(int mflag) 2818 { 2819 2820 return (uma_zalloc(knote_zone, mflag | M_ZERO)); 2821 } 2822 2823 static void 2824 knote_free(struct knote *kn) 2825 { 2826 2827 uma_zfree(knote_zone, kn); 2828 } 2829 2830 /* 2831 * Register the kev w/ the kq specified by fd. 2832 */ 2833 int 2834 kqfd_register(int fd, struct kevent *kev, struct thread *td, int mflag) 2835 { 2836 struct kqueue *kq; 2837 struct file *fp; 2838 cap_rights_t rights; 2839 int error; 2840 2841 error = fget(td, fd, cap_rights_init_one(&rights, CAP_KQUEUE_CHANGE), 2842 &fp); 2843 if (error != 0) 2844 return (error); 2845 if ((error = kqueue_acquire(fp, &kq)) != 0) 2846 goto noacquire; 2847 2848 error = kqueue_register(kq, kev, td, mflag); 2849 kqueue_release(kq, 0); 2850 2851 noacquire: 2852 fdrop(fp, td); 2853 return (error); 2854 } 2855