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 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 * 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(to > 0 || (kn->kn_flags & EV_ONESHOT) != 0 || 823 (kn->kn_sfflags & NOTE_ABSTIME) != 0, 824 ("%s: periodic timer has a calculated zero timeout", __func__)); 825 KASSERT(to >= 0, 826 ("%s: timer has a calculated negative timeout", __func__)); 827 828 if (atomic_fetchadd_int(&kq_ncallouts, 1) + 1 > kq_calloutmax) { 829 atomic_subtract_int(&kq_ncallouts, 1); 830 return (ENOMEM); 831 } 832 833 if ((kn->kn_sfflags & NOTE_ABSTIME) == 0) 834 kn->kn_flags |= EV_CLEAR; /* automatically set */ 835 kn->kn_status &= ~KN_DETACHED; /* knlist_add clears it */ 836 kn->kn_ptr.p_v = kc = malloc(sizeof(*kc), M_KQUEUE, M_WAITOK); 837 kc->kn = kn; 838 kc->p = curproc; 839 kc->cpuid = PCPU_GET(cpuid); 840 kc->flags = 0; 841 callout_init(&kc->c, 1); 842 filt_timerstart(kn, to); 843 844 return (0); 845 } 846 847 static void 848 filt_timerstart(struct knote *kn, sbintime_t to) 849 { 850 struct kq_timer_cb_data *kc; 851 852 kc = kn->kn_ptr.p_v; 853 if ((kn->kn_sfflags & NOTE_ABSTIME) != 0) { 854 kc->next = to; 855 kc->to = 0; 856 } else { 857 kc->next = to + sbinuptime(); 858 kc->to = to; 859 } 860 kqtimer_sched_callout(kc); 861 } 862 863 static void 864 filt_timerdetach(struct knote *kn) 865 { 866 struct kq_timer_cb_data *kc; 867 unsigned int old __unused; 868 bool pending; 869 870 kc = kn->kn_ptr.p_v; 871 do { 872 callout_drain(&kc->c); 873 874 /* 875 * kqtimer_proc_continue() might have rescheduled this callout. 876 * Double-check, using the process mutex as an interlock. 877 */ 878 PROC_LOCK(kc->p); 879 if ((kc->flags & KQ_TIMER_CB_ENQUEUED) != 0) { 880 kc->flags &= ~KQ_TIMER_CB_ENQUEUED; 881 TAILQ_REMOVE(&kc->p->p_kqtim_stop, kc, link); 882 } 883 pending = callout_pending(&kc->c); 884 PROC_UNLOCK(kc->p); 885 } while (pending); 886 free(kc, M_KQUEUE); 887 old = atomic_fetchadd_int(&kq_ncallouts, -1); 888 KASSERT(old > 0, ("Number of callouts cannot become negative")); 889 kn->kn_status |= KN_DETACHED; /* knlist_remove sets it */ 890 } 891 892 static void 893 filt_timertouch(struct knote *kn, struct kevent *kev, u_long type) 894 { 895 struct kq_timer_cb_data *kc; 896 struct kqueue *kq; 897 sbintime_t to; 898 int error; 899 900 switch (type) { 901 case EVENT_REGISTER: 902 /* Handle re-added timers that update data/fflags */ 903 if (kev->flags & EV_ADD) { 904 kc = kn->kn_ptr.p_v; 905 906 /* Drain any existing callout. */ 907 callout_drain(&kc->c); 908 909 /* Throw away any existing undelivered record 910 * of the timer expiration. This is done under 911 * the presumption that if a process is 912 * re-adding this timer with new parameters, 913 * it is no longer interested in what may have 914 * happened under the old parameters. If it is 915 * interested, it can wait for the expiration, 916 * delete the old timer definition, and then 917 * add the new one. 918 * 919 * This has to be done while the kq is locked: 920 * - if enqueued, dequeue 921 * - make it no longer active 922 * - clear the count of expiration events 923 */ 924 kq = kn->kn_kq; 925 KQ_LOCK(kq); 926 if (kn->kn_status & KN_QUEUED) 927 knote_dequeue(kn); 928 929 kn->kn_status &= ~KN_ACTIVE; 930 kn->kn_data = 0; 931 KQ_UNLOCK(kq); 932 933 /* Reschedule timer based on new data/fflags */ 934 kn->kn_sfflags = kev->fflags; 935 kn->kn_sdata = kev->data; 936 error = filt_timervalidate(kn, &to); 937 if (error != 0) { 938 kn->kn_flags |= EV_ERROR; 939 kn->kn_data = error; 940 } else 941 filt_timerstart(kn, to); 942 } 943 break; 944 945 case EVENT_PROCESS: 946 *kev = kn->kn_kevent; 947 if (kn->kn_flags & EV_CLEAR) { 948 kn->kn_data = 0; 949 kn->kn_fflags = 0; 950 } 951 break; 952 953 default: 954 panic("filt_timertouch() - invalid type (%ld)", type); 955 break; 956 } 957 } 958 959 static int 960 filt_timer(struct knote *kn, long hint) 961 { 962 963 return (kn->kn_data != 0); 964 } 965 966 static int 967 filt_userattach(struct knote *kn) 968 { 969 970 /* 971 * EVFILT_USER knotes are not attached to anything in the kernel. 972 */ 973 kn->kn_hook = NULL; 974 if (kn->kn_fflags & NOTE_TRIGGER) 975 kn->kn_hookid = 1; 976 else 977 kn->kn_hookid = 0; 978 return (0); 979 } 980 981 static void 982 filt_userdetach(__unused struct knote *kn) 983 { 984 985 /* 986 * EVFILT_USER knotes are not attached to anything in the kernel. 987 */ 988 } 989 990 static int 991 filt_user(struct knote *kn, __unused long hint) 992 { 993 994 return (kn->kn_hookid); 995 } 996 997 static void 998 filt_usertouch(struct knote *kn, struct kevent *kev, u_long type) 999 { 1000 u_int ffctrl; 1001 1002 switch (type) { 1003 case EVENT_REGISTER: 1004 if (kev->fflags & NOTE_TRIGGER) 1005 kn->kn_hookid = 1; 1006 1007 ffctrl = kev->fflags & NOTE_FFCTRLMASK; 1008 kev->fflags &= NOTE_FFLAGSMASK; 1009 switch (ffctrl) { 1010 case NOTE_FFNOP: 1011 break; 1012 1013 case NOTE_FFAND: 1014 kn->kn_sfflags &= kev->fflags; 1015 break; 1016 1017 case NOTE_FFOR: 1018 kn->kn_sfflags |= kev->fflags; 1019 break; 1020 1021 case NOTE_FFCOPY: 1022 kn->kn_sfflags = kev->fflags; 1023 break; 1024 1025 default: 1026 /* XXX Return error? */ 1027 break; 1028 } 1029 kn->kn_sdata = kev->data; 1030 if (kev->flags & EV_CLEAR) { 1031 kn->kn_hookid = 0; 1032 kn->kn_data = 0; 1033 kn->kn_fflags = 0; 1034 } 1035 break; 1036 1037 case EVENT_PROCESS: 1038 *kev = kn->kn_kevent; 1039 kev->fflags = kn->kn_sfflags; 1040 kev->data = kn->kn_sdata; 1041 if (kn->kn_flags & EV_CLEAR) { 1042 kn->kn_hookid = 0; 1043 kn->kn_data = 0; 1044 kn->kn_fflags = 0; 1045 } 1046 break; 1047 1048 default: 1049 panic("filt_usertouch() - invalid type (%ld)", type); 1050 break; 1051 } 1052 } 1053 1054 int 1055 sys_kqueue(struct thread *td, struct kqueue_args *uap) 1056 { 1057 1058 return (kern_kqueue(td, 0, NULL)); 1059 } 1060 1061 static void 1062 kqueue_init(struct kqueue *kq) 1063 { 1064 1065 mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF | MTX_DUPOK); 1066 TAILQ_INIT(&kq->kq_head); 1067 knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock); 1068 TASK_INIT(&kq->kq_task, 0, kqueue_task, kq); 1069 } 1070 1071 int 1072 kern_kqueue(struct thread *td, int flags, struct filecaps *fcaps) 1073 { 1074 struct filedesc *fdp; 1075 struct kqueue *kq; 1076 struct file *fp; 1077 struct ucred *cred; 1078 int fd, error; 1079 1080 fdp = td->td_proc->p_fd; 1081 cred = td->td_ucred; 1082 if (!chgkqcnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_KQUEUES))) 1083 return (ENOMEM); 1084 1085 error = falloc_caps(td, &fp, &fd, flags, fcaps); 1086 if (error != 0) { 1087 chgkqcnt(cred->cr_ruidinfo, -1, 0); 1088 return (error); 1089 } 1090 1091 /* An extra reference on `fp' has been held for us by falloc(). */ 1092 kq = malloc(sizeof *kq, M_KQUEUE, M_WAITOK | M_ZERO); 1093 kqueue_init(kq); 1094 kq->kq_fdp = fdp; 1095 kq->kq_cred = crhold(cred); 1096 1097 FILEDESC_XLOCK(fdp); 1098 TAILQ_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list); 1099 FILEDESC_XUNLOCK(fdp); 1100 1101 finit(fp, FREAD | FWRITE, DTYPE_KQUEUE, kq, &kqueueops); 1102 fdrop(fp, td); 1103 1104 td->td_retval[0] = fd; 1105 return (0); 1106 } 1107 1108 struct g_kevent_args { 1109 int fd; 1110 const void *changelist; 1111 int nchanges; 1112 void *eventlist; 1113 int nevents; 1114 const struct timespec *timeout; 1115 }; 1116 1117 int 1118 sys_kevent(struct thread *td, struct kevent_args *uap) 1119 { 1120 struct kevent_copyops k_ops = { 1121 .arg = uap, 1122 .k_copyout = kevent_copyout, 1123 .k_copyin = kevent_copyin, 1124 .kevent_size = sizeof(struct kevent), 1125 }; 1126 struct g_kevent_args gk_args = { 1127 .fd = uap->fd, 1128 .changelist = uap->changelist, 1129 .nchanges = uap->nchanges, 1130 .eventlist = uap->eventlist, 1131 .nevents = uap->nevents, 1132 .timeout = uap->timeout, 1133 }; 1134 1135 return (kern_kevent_generic(td, &gk_args, &k_ops, "kevent")); 1136 } 1137 1138 static int 1139 kern_kevent_generic(struct thread *td, struct g_kevent_args *uap, 1140 struct kevent_copyops *k_ops, const char *struct_name) 1141 { 1142 struct timespec ts, *tsp; 1143 #ifdef KTRACE 1144 struct kevent *eventlist = uap->eventlist; 1145 #endif 1146 int error; 1147 1148 if (uap->timeout != NULL) { 1149 error = copyin(uap->timeout, &ts, sizeof(ts)); 1150 if (error) 1151 return (error); 1152 tsp = &ts; 1153 } else 1154 tsp = NULL; 1155 1156 #ifdef KTRACE 1157 if (KTRPOINT(td, KTR_STRUCT_ARRAY)) 1158 ktrstructarray(struct_name, UIO_USERSPACE, uap->changelist, 1159 uap->nchanges, k_ops->kevent_size); 1160 #endif 1161 1162 error = kern_kevent(td, uap->fd, uap->nchanges, uap->nevents, 1163 k_ops, tsp); 1164 1165 #ifdef KTRACE 1166 if (error == 0 && KTRPOINT(td, KTR_STRUCT_ARRAY)) 1167 ktrstructarray(struct_name, UIO_USERSPACE, eventlist, 1168 td->td_retval[0], k_ops->kevent_size); 1169 #endif 1170 1171 return (error); 1172 } 1173 1174 /* 1175 * Copy 'count' items into the destination list pointed to by uap->eventlist. 1176 */ 1177 static int 1178 kevent_copyout(void *arg, struct kevent *kevp, int count) 1179 { 1180 struct kevent_args *uap; 1181 int error; 1182 1183 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1184 uap = (struct kevent_args *)arg; 1185 1186 error = copyout(kevp, uap->eventlist, count * sizeof *kevp); 1187 if (error == 0) 1188 uap->eventlist += count; 1189 return (error); 1190 } 1191 1192 /* 1193 * Copy 'count' items from the list pointed to by uap->changelist. 1194 */ 1195 static int 1196 kevent_copyin(void *arg, struct kevent *kevp, int count) 1197 { 1198 struct kevent_args *uap; 1199 int error; 1200 1201 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1202 uap = (struct kevent_args *)arg; 1203 1204 error = copyin(uap->changelist, kevp, count * sizeof *kevp); 1205 if (error == 0) 1206 uap->changelist += count; 1207 return (error); 1208 } 1209 1210 #ifdef COMPAT_FREEBSD11 1211 static int 1212 kevent11_copyout(void *arg, struct kevent *kevp, int count) 1213 { 1214 struct freebsd11_kevent_args *uap; 1215 struct freebsd11_kevent kev11; 1216 int error, i; 1217 1218 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1219 uap = (struct freebsd11_kevent_args *)arg; 1220 1221 for (i = 0; i < count; i++) { 1222 kev11.ident = kevp->ident; 1223 kev11.filter = kevp->filter; 1224 kev11.flags = kevp->flags; 1225 kev11.fflags = kevp->fflags; 1226 kev11.data = kevp->data; 1227 kev11.udata = kevp->udata; 1228 error = copyout(&kev11, uap->eventlist, sizeof(kev11)); 1229 if (error != 0) 1230 break; 1231 uap->eventlist++; 1232 kevp++; 1233 } 1234 return (error); 1235 } 1236 1237 /* 1238 * Copy 'count' items from the list pointed to by uap->changelist. 1239 */ 1240 static int 1241 kevent11_copyin(void *arg, struct kevent *kevp, int count) 1242 { 1243 struct freebsd11_kevent_args *uap; 1244 struct freebsd11_kevent kev11; 1245 int error, i; 1246 1247 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1248 uap = (struct freebsd11_kevent_args *)arg; 1249 1250 for (i = 0; i < count; i++) { 1251 error = copyin(uap->changelist, &kev11, sizeof(kev11)); 1252 if (error != 0) 1253 break; 1254 kevp->ident = kev11.ident; 1255 kevp->filter = kev11.filter; 1256 kevp->flags = kev11.flags; 1257 kevp->fflags = kev11.fflags; 1258 kevp->data = (uintptr_t)kev11.data; 1259 kevp->udata = kev11.udata; 1260 bzero(&kevp->ext, sizeof(kevp->ext)); 1261 uap->changelist++; 1262 kevp++; 1263 } 1264 return (error); 1265 } 1266 1267 int 1268 freebsd11_kevent(struct thread *td, struct freebsd11_kevent_args *uap) 1269 { 1270 struct kevent_copyops k_ops = { 1271 .arg = uap, 1272 .k_copyout = kevent11_copyout, 1273 .k_copyin = kevent11_copyin, 1274 .kevent_size = sizeof(struct freebsd11_kevent), 1275 }; 1276 struct g_kevent_args gk_args = { 1277 .fd = uap->fd, 1278 .changelist = uap->changelist, 1279 .nchanges = uap->nchanges, 1280 .eventlist = uap->eventlist, 1281 .nevents = uap->nevents, 1282 .timeout = uap->timeout, 1283 }; 1284 1285 return (kern_kevent_generic(td, &gk_args, &k_ops, "freebsd11_kevent")); 1286 } 1287 #endif 1288 1289 int 1290 kern_kevent(struct thread *td, int fd, int nchanges, int nevents, 1291 struct kevent_copyops *k_ops, const struct timespec *timeout) 1292 { 1293 cap_rights_t rights; 1294 struct file *fp; 1295 int error; 1296 1297 cap_rights_init_zero(&rights); 1298 if (nchanges > 0) 1299 cap_rights_set_one(&rights, CAP_KQUEUE_CHANGE); 1300 if (nevents > 0) 1301 cap_rights_set_one(&rights, CAP_KQUEUE_EVENT); 1302 error = fget(td, fd, &rights, &fp); 1303 if (error != 0) 1304 return (error); 1305 1306 error = kern_kevent_fp(td, fp, nchanges, nevents, k_ops, timeout); 1307 fdrop(fp, td); 1308 1309 return (error); 1310 } 1311 1312 static int 1313 kqueue_kevent(struct kqueue *kq, struct thread *td, int nchanges, int nevents, 1314 struct kevent_copyops *k_ops, const struct timespec *timeout) 1315 { 1316 struct kevent keva[KQ_NEVENTS]; 1317 struct kevent *kevp, *changes; 1318 int i, n, nerrors, error; 1319 1320 if (nchanges < 0) 1321 return (EINVAL); 1322 1323 nerrors = 0; 1324 while (nchanges > 0) { 1325 n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges; 1326 error = k_ops->k_copyin(k_ops->arg, keva, n); 1327 if (error) 1328 return (error); 1329 changes = keva; 1330 for (i = 0; i < n; i++) { 1331 kevp = &changes[i]; 1332 if (!kevp->filter) 1333 continue; 1334 kevp->flags &= ~EV_SYSFLAGS; 1335 error = kqueue_register(kq, kevp, td, M_WAITOK); 1336 if (error || (kevp->flags & EV_RECEIPT)) { 1337 if (nevents == 0) 1338 return (error); 1339 kevp->flags = EV_ERROR; 1340 kevp->data = error; 1341 (void)k_ops->k_copyout(k_ops->arg, kevp, 1); 1342 nevents--; 1343 nerrors++; 1344 } 1345 } 1346 nchanges -= n; 1347 } 1348 if (nerrors) { 1349 td->td_retval[0] = nerrors; 1350 return (0); 1351 } 1352 1353 return (kqueue_scan(kq, nevents, k_ops, timeout, keva, td)); 1354 } 1355 1356 int 1357 kern_kevent_fp(struct thread *td, struct file *fp, int nchanges, int nevents, 1358 struct kevent_copyops *k_ops, const struct timespec *timeout) 1359 { 1360 struct kqueue *kq; 1361 int error; 1362 1363 error = kqueue_acquire(fp, &kq); 1364 if (error != 0) 1365 return (error); 1366 error = kqueue_kevent(kq, td, nchanges, nevents, k_ops, timeout); 1367 kqueue_release(kq, 0); 1368 return (error); 1369 } 1370 1371 /* 1372 * Performs a kevent() call on a temporarily created kqueue. This can be 1373 * used to perform one-shot polling, similar to poll() and select(). 1374 */ 1375 int 1376 kern_kevent_anonymous(struct thread *td, int nevents, 1377 struct kevent_copyops *k_ops) 1378 { 1379 struct kqueue kq = {}; 1380 int error; 1381 1382 kqueue_init(&kq); 1383 kq.kq_refcnt = 1; 1384 error = kqueue_kevent(&kq, td, nevents, nevents, k_ops, NULL); 1385 kqueue_drain(&kq, td); 1386 kqueue_destroy(&kq); 1387 return (error); 1388 } 1389 1390 int 1391 kqueue_add_filteropts(int filt, struct filterops *filtops) 1392 { 1393 int error; 1394 1395 error = 0; 1396 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) { 1397 printf( 1398 "trying to add a filterop that is out of range: %d is beyond %d\n", 1399 ~filt, EVFILT_SYSCOUNT); 1400 return EINVAL; 1401 } 1402 mtx_lock(&filterops_lock); 1403 if (sysfilt_ops[~filt].for_fop != &null_filtops && 1404 sysfilt_ops[~filt].for_fop != NULL) 1405 error = EEXIST; 1406 else { 1407 sysfilt_ops[~filt].for_fop = filtops; 1408 sysfilt_ops[~filt].for_refcnt = 0; 1409 } 1410 mtx_unlock(&filterops_lock); 1411 1412 return (error); 1413 } 1414 1415 int 1416 kqueue_del_filteropts(int filt) 1417 { 1418 int error; 1419 1420 error = 0; 1421 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1422 return EINVAL; 1423 1424 mtx_lock(&filterops_lock); 1425 if (sysfilt_ops[~filt].for_fop == &null_filtops || 1426 sysfilt_ops[~filt].for_fop == NULL) 1427 error = EINVAL; 1428 else if (sysfilt_ops[~filt].for_refcnt != 0) 1429 error = EBUSY; 1430 else { 1431 sysfilt_ops[~filt].for_fop = &null_filtops; 1432 sysfilt_ops[~filt].for_refcnt = 0; 1433 } 1434 mtx_unlock(&filterops_lock); 1435 1436 return error; 1437 } 1438 1439 static struct filterops * 1440 kqueue_fo_find(int filt) 1441 { 1442 1443 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1444 return NULL; 1445 1446 if (sysfilt_ops[~filt].for_nolock) 1447 return sysfilt_ops[~filt].for_fop; 1448 1449 mtx_lock(&filterops_lock); 1450 sysfilt_ops[~filt].for_refcnt++; 1451 if (sysfilt_ops[~filt].for_fop == NULL) 1452 sysfilt_ops[~filt].for_fop = &null_filtops; 1453 mtx_unlock(&filterops_lock); 1454 1455 return sysfilt_ops[~filt].for_fop; 1456 } 1457 1458 static void 1459 kqueue_fo_release(int filt) 1460 { 1461 1462 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1463 return; 1464 1465 if (sysfilt_ops[~filt].for_nolock) 1466 return; 1467 1468 mtx_lock(&filterops_lock); 1469 KASSERT(sysfilt_ops[~filt].for_refcnt > 0, 1470 ("filter object refcount not valid on release")); 1471 sysfilt_ops[~filt].for_refcnt--; 1472 mtx_unlock(&filterops_lock); 1473 } 1474 1475 /* 1476 * A ref to kq (obtained via kqueue_acquire) must be held. 1477 */ 1478 static int 1479 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, 1480 int mflag) 1481 { 1482 struct filterops *fops; 1483 struct file *fp; 1484 struct knote *kn, *tkn; 1485 struct knlist *knl; 1486 int error, filt, event; 1487 int haskqglobal, filedesc_unlock; 1488 1489 if ((kev->flags & (EV_ENABLE | EV_DISABLE)) == (EV_ENABLE | EV_DISABLE)) 1490 return (EINVAL); 1491 1492 fp = NULL; 1493 kn = NULL; 1494 knl = NULL; 1495 error = 0; 1496 haskqglobal = 0; 1497 filedesc_unlock = 0; 1498 1499 filt = kev->filter; 1500 fops = kqueue_fo_find(filt); 1501 if (fops == NULL) 1502 return EINVAL; 1503 1504 if (kev->flags & EV_ADD) { 1505 /* Reject an invalid flag pair early */ 1506 if (kev->flags & EV_KEEPUDATA) { 1507 tkn = NULL; 1508 error = EINVAL; 1509 goto done; 1510 } 1511 1512 /* 1513 * Prevent waiting with locks. Non-sleepable 1514 * allocation failures are handled in the loop, only 1515 * if the spare knote appears to be actually required. 1516 */ 1517 tkn = knote_alloc(mflag); 1518 } else { 1519 tkn = NULL; 1520 } 1521 1522 findkn: 1523 if (fops->f_isfd) { 1524 KASSERT(td != NULL, ("td is NULL")); 1525 if (kev->ident > INT_MAX) 1526 error = EBADF; 1527 else 1528 error = fget(td, kev->ident, &cap_event_rights, &fp); 1529 if (error) 1530 goto done; 1531 1532 if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops, 1533 kev->ident, M_NOWAIT) != 0) { 1534 /* try again */ 1535 fdrop(fp, td); 1536 fp = NULL; 1537 error = kqueue_expand(kq, fops, kev->ident, mflag); 1538 if (error) 1539 goto done; 1540 goto findkn; 1541 } 1542 1543 if (fp->f_type == DTYPE_KQUEUE) { 1544 /* 1545 * If we add some intelligence about what we are doing, 1546 * we should be able to support events on ourselves. 1547 * We need to know when we are doing this to prevent 1548 * getting both the knlist lock and the kq lock since 1549 * they are the same thing. 1550 */ 1551 if (fp->f_data == kq) { 1552 error = EINVAL; 1553 goto done; 1554 } 1555 1556 /* 1557 * Pre-lock the filedesc before the global 1558 * lock mutex, see the comment in 1559 * kqueue_close(). 1560 */ 1561 FILEDESC_XLOCK(td->td_proc->p_fd); 1562 filedesc_unlock = 1; 1563 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1564 } 1565 1566 KQ_LOCK(kq); 1567 if (kev->ident < kq->kq_knlistsize) { 1568 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link) 1569 if (kev->filter == kn->kn_filter) 1570 break; 1571 } 1572 } else { 1573 if ((kev->flags & EV_ADD) == EV_ADD) { 1574 error = kqueue_expand(kq, fops, kev->ident, mflag); 1575 if (error != 0) 1576 goto done; 1577 } 1578 1579 KQ_LOCK(kq); 1580 1581 /* 1582 * If possible, find an existing knote to use for this kevent. 1583 */ 1584 if (kev->filter == EVFILT_PROC && 1585 (kev->flags & (EV_FLAG1 | EV_FLAG2)) != 0) { 1586 /* This is an internal creation of a process tracking 1587 * note. Don't attempt to coalesce this with an 1588 * existing note. 1589 */ 1590 ; 1591 } else if (kq->kq_knhashmask != 0) { 1592 struct klist *list; 1593 1594 list = &kq->kq_knhash[ 1595 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)]; 1596 SLIST_FOREACH(kn, list, kn_link) 1597 if (kev->ident == kn->kn_id && 1598 kev->filter == kn->kn_filter) 1599 break; 1600 } 1601 } 1602 1603 /* knote is in the process of changing, wait for it to stabilize. */ 1604 if (kn != NULL && kn_in_flux(kn)) { 1605 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1606 if (filedesc_unlock) { 1607 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1608 filedesc_unlock = 0; 1609 } 1610 kq->kq_state |= KQ_FLUXWAIT; 1611 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0); 1612 if (fp != NULL) { 1613 fdrop(fp, td); 1614 fp = NULL; 1615 } 1616 goto findkn; 1617 } 1618 1619 /* 1620 * kn now contains the matching knote, or NULL if no match 1621 */ 1622 if (kn == NULL) { 1623 if (kev->flags & EV_ADD) { 1624 kn = tkn; 1625 tkn = NULL; 1626 if (kn == NULL) { 1627 KQ_UNLOCK(kq); 1628 error = ENOMEM; 1629 goto done; 1630 } 1631 kn->kn_fp = fp; 1632 kn->kn_kq = kq; 1633 kn->kn_fop = fops; 1634 /* 1635 * apply reference counts to knote structure, and 1636 * do not release it at the end of this routine. 1637 */ 1638 fops = NULL; 1639 fp = NULL; 1640 1641 kn->kn_sfflags = kev->fflags; 1642 kn->kn_sdata = kev->data; 1643 kev->fflags = 0; 1644 kev->data = 0; 1645 kn->kn_kevent = *kev; 1646 kn->kn_kevent.flags &= ~(EV_ADD | EV_DELETE | 1647 EV_ENABLE | EV_DISABLE | EV_FORCEONESHOT); 1648 kn->kn_status = KN_DETACHED; 1649 if ((kev->flags & EV_DISABLE) != 0) 1650 kn->kn_status |= KN_DISABLED; 1651 kn_enter_flux(kn); 1652 1653 error = knote_attach(kn, kq); 1654 KQ_UNLOCK(kq); 1655 if (error != 0) { 1656 tkn = kn; 1657 goto done; 1658 } 1659 1660 if ((error = kn->kn_fop->f_attach(kn)) != 0) { 1661 knote_drop_detached(kn, td); 1662 goto done; 1663 } 1664 knl = kn_list_lock(kn); 1665 goto done_ev_add; 1666 } else { 1667 /* No matching knote and the EV_ADD flag is not set. */ 1668 KQ_UNLOCK(kq); 1669 error = ENOENT; 1670 goto done; 1671 } 1672 } 1673 1674 if (kev->flags & EV_DELETE) { 1675 kn_enter_flux(kn); 1676 KQ_UNLOCK(kq); 1677 knote_drop(kn, td); 1678 goto done; 1679 } 1680 1681 if (kev->flags & EV_FORCEONESHOT) { 1682 kn->kn_flags |= EV_ONESHOT; 1683 KNOTE_ACTIVATE(kn, 1); 1684 } 1685 1686 if ((kev->flags & EV_ENABLE) != 0) 1687 kn->kn_status &= ~KN_DISABLED; 1688 else if ((kev->flags & EV_DISABLE) != 0) 1689 kn->kn_status |= KN_DISABLED; 1690 1691 /* 1692 * The user may change some filter values after the initial EV_ADD, 1693 * but doing so will not reset any filter which has already been 1694 * triggered. 1695 */ 1696 kn->kn_status |= KN_SCAN; 1697 kn_enter_flux(kn); 1698 KQ_UNLOCK(kq); 1699 knl = kn_list_lock(kn); 1700 if ((kev->flags & EV_KEEPUDATA) == 0) 1701 kn->kn_kevent.udata = kev->udata; 1702 if (!fops->f_isfd && fops->f_touch != NULL) { 1703 fops->f_touch(kn, kev, EVENT_REGISTER); 1704 } else { 1705 kn->kn_sfflags = kev->fflags; 1706 kn->kn_sdata = kev->data; 1707 } 1708 1709 done_ev_add: 1710 /* 1711 * We can get here with kn->kn_knlist == NULL. This can happen when 1712 * the initial attach event decides that the event is "completed" 1713 * already, e.g., filt_procattach() is called on a zombie process. It 1714 * will call filt_proc() which will remove it from the list, and NULL 1715 * kn_knlist. 1716 * 1717 * KN_DISABLED will be stable while the knote is in flux, so the 1718 * unlocked read will not race with an update. 1719 */ 1720 if ((kn->kn_status & KN_DISABLED) == 0) 1721 event = kn->kn_fop->f_event(kn, 0); 1722 else 1723 event = 0; 1724 1725 KQ_LOCK(kq); 1726 if (event) 1727 kn->kn_status |= KN_ACTIVE; 1728 if ((kn->kn_status & (KN_ACTIVE | KN_DISABLED | KN_QUEUED)) == 1729 KN_ACTIVE) 1730 knote_enqueue(kn); 1731 kn->kn_status &= ~KN_SCAN; 1732 kn_leave_flux(kn); 1733 kn_list_unlock(knl); 1734 KQ_UNLOCK_FLUX(kq); 1735 1736 done: 1737 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1738 if (filedesc_unlock) 1739 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1740 if (fp != NULL) 1741 fdrop(fp, td); 1742 knote_free(tkn); 1743 if (fops != NULL) 1744 kqueue_fo_release(filt); 1745 return (error); 1746 } 1747 1748 static int 1749 kqueue_acquire(struct file *fp, struct kqueue **kqp) 1750 { 1751 int error; 1752 struct kqueue *kq; 1753 1754 error = 0; 1755 1756 kq = fp->f_data; 1757 if (fp->f_type != DTYPE_KQUEUE || kq == NULL) 1758 return (EBADF); 1759 *kqp = kq; 1760 KQ_LOCK(kq); 1761 if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) { 1762 KQ_UNLOCK(kq); 1763 return (EBADF); 1764 } 1765 kq->kq_refcnt++; 1766 KQ_UNLOCK(kq); 1767 1768 return error; 1769 } 1770 1771 static void 1772 kqueue_release(struct kqueue *kq, int locked) 1773 { 1774 if (locked) 1775 KQ_OWNED(kq); 1776 else 1777 KQ_LOCK(kq); 1778 kq->kq_refcnt--; 1779 if (kq->kq_refcnt == 1) 1780 wakeup(&kq->kq_refcnt); 1781 if (!locked) 1782 KQ_UNLOCK(kq); 1783 } 1784 1785 void 1786 kqueue_drain_schedtask(void) 1787 { 1788 taskqueue_quiesce(taskqueue_kqueue_ctx); 1789 } 1790 1791 static void 1792 kqueue_schedtask(struct kqueue *kq) 1793 { 1794 struct thread *td; 1795 1796 KQ_OWNED(kq); 1797 KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN), 1798 ("scheduling kqueue task while draining")); 1799 1800 if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) { 1801 taskqueue_enqueue(taskqueue_kqueue_ctx, &kq->kq_task); 1802 kq->kq_state |= KQ_TASKSCHED; 1803 td = curthread; 1804 thread_lock(td); 1805 td->td_flags |= TDF_ASTPENDING | TDF_KQTICKLED; 1806 thread_unlock(td); 1807 } 1808 } 1809 1810 /* 1811 * Expand the kq to make sure we have storage for fops/ident pair. 1812 * 1813 * Return 0 on success (or no work necessary), return errno on failure. 1814 */ 1815 static int 1816 kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident, 1817 int mflag) 1818 { 1819 struct klist *list, *tmp_knhash, *to_free; 1820 u_long tmp_knhashmask; 1821 int error, fd, size; 1822 1823 KQ_NOTOWNED(kq); 1824 1825 error = 0; 1826 to_free = NULL; 1827 if (fops->f_isfd) { 1828 fd = ident; 1829 if (kq->kq_knlistsize <= fd) { 1830 size = kq->kq_knlistsize; 1831 while (size <= fd) 1832 size += KQEXTENT; 1833 list = malloc(size * sizeof(*list), M_KQUEUE, mflag); 1834 if (list == NULL) 1835 return ENOMEM; 1836 KQ_LOCK(kq); 1837 if ((kq->kq_state & KQ_CLOSING) != 0) { 1838 to_free = list; 1839 error = EBADF; 1840 } else if (kq->kq_knlistsize > fd) { 1841 to_free = list; 1842 } else { 1843 if (kq->kq_knlist != NULL) { 1844 bcopy(kq->kq_knlist, list, 1845 kq->kq_knlistsize * sizeof(*list)); 1846 to_free = kq->kq_knlist; 1847 kq->kq_knlist = NULL; 1848 } 1849 bzero((caddr_t)list + 1850 kq->kq_knlistsize * sizeof(*list), 1851 (size - kq->kq_knlistsize) * sizeof(*list)); 1852 kq->kq_knlistsize = size; 1853 kq->kq_knlist = list; 1854 } 1855 KQ_UNLOCK(kq); 1856 } 1857 } else { 1858 if (kq->kq_knhashmask == 0) { 1859 tmp_knhash = hashinit_flags(KN_HASHSIZE, M_KQUEUE, 1860 &tmp_knhashmask, (mflag & M_WAITOK) != 0 ? 1861 HASH_WAITOK : HASH_NOWAIT); 1862 if (tmp_knhash == NULL) 1863 return (ENOMEM); 1864 KQ_LOCK(kq); 1865 if ((kq->kq_state & KQ_CLOSING) != 0) { 1866 to_free = tmp_knhash; 1867 error = EBADF; 1868 } else if (kq->kq_knhashmask == 0) { 1869 kq->kq_knhash = tmp_knhash; 1870 kq->kq_knhashmask = tmp_knhashmask; 1871 } else { 1872 to_free = tmp_knhash; 1873 } 1874 KQ_UNLOCK(kq); 1875 } 1876 } 1877 free(to_free, M_KQUEUE); 1878 1879 KQ_NOTOWNED(kq); 1880 return (error); 1881 } 1882 1883 static void 1884 kqueue_task(void *arg, int pending) 1885 { 1886 struct kqueue *kq; 1887 int haskqglobal; 1888 1889 haskqglobal = 0; 1890 kq = arg; 1891 1892 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1893 KQ_LOCK(kq); 1894 1895 KNOTE_LOCKED(&kq->kq_sel.si_note, 0); 1896 1897 kq->kq_state &= ~KQ_TASKSCHED; 1898 if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) { 1899 wakeup(&kq->kq_state); 1900 } 1901 KQ_UNLOCK(kq); 1902 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1903 } 1904 1905 /* 1906 * Scan, update kn_data (if not ONESHOT), and copyout triggered events. 1907 * We treat KN_MARKER knotes as if they are in flux. 1908 */ 1909 static int 1910 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops, 1911 const struct timespec *tsp, struct kevent *keva, struct thread *td) 1912 { 1913 struct kevent *kevp; 1914 struct knote *kn, *marker; 1915 struct knlist *knl; 1916 sbintime_t asbt, rsbt; 1917 int count, error, haskqglobal, influx, nkev, touch; 1918 1919 count = maxevents; 1920 nkev = 0; 1921 error = 0; 1922 haskqglobal = 0; 1923 1924 if (maxevents == 0) 1925 goto done_nl; 1926 if (maxevents < 0) { 1927 error = EINVAL; 1928 goto done_nl; 1929 } 1930 1931 rsbt = 0; 1932 if (tsp != NULL) { 1933 if (!timespecvalid_interval(tsp)) { 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 { 2191 2192 bzero((void *)st, sizeof *st); 2193 /* 2194 * We no longer return kq_count because the unlocked value is useless. 2195 * If you spent all this time getting the count, why not spend your 2196 * syscall better by calling kevent? 2197 * 2198 * XXX - This is needed for libc_r. 2199 */ 2200 st->st_mode = S_IFIFO; 2201 return (0); 2202 } 2203 2204 static void 2205 kqueue_drain(struct kqueue *kq, struct thread *td) 2206 { 2207 struct knote *kn; 2208 int i; 2209 2210 KQ_LOCK(kq); 2211 2212 KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING, 2213 ("kqueue already closing")); 2214 kq->kq_state |= KQ_CLOSING; 2215 if (kq->kq_refcnt > 1) 2216 msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0); 2217 2218 KASSERT(kq->kq_refcnt == 1, ("other refs are out there!")); 2219 2220 KASSERT(knlist_empty(&kq->kq_sel.si_note), 2221 ("kqueue's knlist not empty")); 2222 2223 for (i = 0; i < kq->kq_knlistsize; i++) { 2224 while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) { 2225 if (kn_in_flux(kn)) { 2226 kq->kq_state |= KQ_FLUXWAIT; 2227 msleep(kq, &kq->kq_lock, PSOCK, "kqclo1", 0); 2228 continue; 2229 } 2230 kn_enter_flux(kn); 2231 KQ_UNLOCK(kq); 2232 knote_drop(kn, td); 2233 KQ_LOCK(kq); 2234 } 2235 } 2236 if (kq->kq_knhashmask != 0) { 2237 for (i = 0; i <= kq->kq_knhashmask; i++) { 2238 while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) { 2239 if (kn_in_flux(kn)) { 2240 kq->kq_state |= KQ_FLUXWAIT; 2241 msleep(kq, &kq->kq_lock, PSOCK, 2242 "kqclo2", 0); 2243 continue; 2244 } 2245 kn_enter_flux(kn); 2246 KQ_UNLOCK(kq); 2247 knote_drop(kn, td); 2248 KQ_LOCK(kq); 2249 } 2250 } 2251 } 2252 2253 if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) { 2254 kq->kq_state |= KQ_TASKDRAIN; 2255 msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0); 2256 } 2257 2258 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2259 selwakeuppri(&kq->kq_sel, PSOCK); 2260 if (!SEL_WAITING(&kq->kq_sel)) 2261 kq->kq_state &= ~KQ_SEL; 2262 } 2263 2264 KQ_UNLOCK(kq); 2265 } 2266 2267 static void 2268 kqueue_destroy(struct kqueue *kq) 2269 { 2270 2271 KASSERT(kq->kq_fdp == NULL, 2272 ("kqueue still attached to a file descriptor")); 2273 seldrain(&kq->kq_sel); 2274 knlist_destroy(&kq->kq_sel.si_note); 2275 mtx_destroy(&kq->kq_lock); 2276 2277 if (kq->kq_knhash != NULL) 2278 free(kq->kq_knhash, M_KQUEUE); 2279 if (kq->kq_knlist != NULL) 2280 free(kq->kq_knlist, M_KQUEUE); 2281 2282 funsetown(&kq->kq_sigio); 2283 } 2284 2285 /*ARGSUSED*/ 2286 static int 2287 kqueue_close(struct file *fp, struct thread *td) 2288 { 2289 struct kqueue *kq = fp->f_data; 2290 struct filedesc *fdp; 2291 int error; 2292 int filedesc_unlock; 2293 2294 if ((error = kqueue_acquire(fp, &kq))) 2295 return error; 2296 kqueue_drain(kq, td); 2297 2298 /* 2299 * We could be called due to the knote_drop() doing fdrop(), 2300 * called from kqueue_register(). In this case the global 2301 * lock is owned, and filedesc sx is locked before, to not 2302 * take the sleepable lock after non-sleepable. 2303 */ 2304 fdp = kq->kq_fdp; 2305 kq->kq_fdp = NULL; 2306 if (!sx_xlocked(FILEDESC_LOCK(fdp))) { 2307 FILEDESC_XLOCK(fdp); 2308 filedesc_unlock = 1; 2309 } else 2310 filedesc_unlock = 0; 2311 TAILQ_REMOVE(&fdp->fd_kqlist, kq, kq_list); 2312 if (filedesc_unlock) 2313 FILEDESC_XUNLOCK(fdp); 2314 2315 kqueue_destroy(kq); 2316 chgkqcnt(kq->kq_cred->cr_ruidinfo, -1, 0); 2317 crfree(kq->kq_cred); 2318 free(kq, M_KQUEUE); 2319 fp->f_data = NULL; 2320 2321 return (0); 2322 } 2323 2324 static int 2325 kqueue_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 2326 { 2327 2328 kif->kf_type = KF_TYPE_KQUEUE; 2329 return (0); 2330 } 2331 2332 static void 2333 kqueue_wakeup(struct kqueue *kq) 2334 { 2335 KQ_OWNED(kq); 2336 2337 if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) { 2338 kq->kq_state &= ~KQ_SLEEP; 2339 wakeup(kq); 2340 } 2341 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2342 selwakeuppri(&kq->kq_sel, PSOCK); 2343 if (!SEL_WAITING(&kq->kq_sel)) 2344 kq->kq_state &= ~KQ_SEL; 2345 } 2346 if (!knlist_empty(&kq->kq_sel.si_note)) 2347 kqueue_schedtask(kq); 2348 if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) { 2349 pgsigio(&kq->kq_sigio, SIGIO, 0); 2350 } 2351 } 2352 2353 /* 2354 * Walk down a list of knotes, activating them if their event has triggered. 2355 * 2356 * There is a possibility to optimize in the case of one kq watching another. 2357 * Instead of scheduling a task to wake it up, you could pass enough state 2358 * down the chain to make up the parent kqueue. Make this code functional 2359 * first. 2360 */ 2361 void 2362 knote(struct knlist *list, long hint, int lockflags) 2363 { 2364 struct kqueue *kq; 2365 struct knote *kn, *tkn; 2366 int error; 2367 2368 if (list == NULL) 2369 return; 2370 2371 KNL_ASSERT_LOCK(list, lockflags & KNF_LISTLOCKED); 2372 2373 if ((lockflags & KNF_LISTLOCKED) == 0) 2374 list->kl_lock(list->kl_lockarg); 2375 2376 /* 2377 * If we unlock the list lock (and enter influx), we can 2378 * eliminate the kqueue scheduling, but this will introduce 2379 * four lock/unlock's for each knote to test. Also, marker 2380 * would be needed to keep iteration position, since filters 2381 * or other threads could remove events. 2382 */ 2383 SLIST_FOREACH_SAFE(kn, &list->kl_list, kn_selnext, tkn) { 2384 kq = kn->kn_kq; 2385 KQ_LOCK(kq); 2386 if (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0) { 2387 /* 2388 * Do not process the influx notes, except for 2389 * the influx coming from the kq unlock in the 2390 * kqueue_scan(). In the later case, we do 2391 * not interfere with the scan, since the code 2392 * fragment in kqueue_scan() locks the knlist, 2393 * and cannot proceed until we finished. 2394 */ 2395 KQ_UNLOCK(kq); 2396 } else if ((lockflags & KNF_NOKQLOCK) != 0) { 2397 kn_enter_flux(kn); 2398 KQ_UNLOCK(kq); 2399 error = kn->kn_fop->f_event(kn, hint); 2400 KQ_LOCK(kq); 2401 kn_leave_flux(kn); 2402 if (error) 2403 KNOTE_ACTIVATE(kn, 1); 2404 KQ_UNLOCK_FLUX(kq); 2405 } else { 2406 if (kn->kn_fop->f_event(kn, hint)) 2407 KNOTE_ACTIVATE(kn, 1); 2408 KQ_UNLOCK(kq); 2409 } 2410 } 2411 if ((lockflags & KNF_LISTLOCKED) == 0) 2412 list->kl_unlock(list->kl_lockarg); 2413 } 2414 2415 /* 2416 * add a knote to a knlist 2417 */ 2418 void 2419 knlist_add(struct knlist *knl, struct knote *kn, int islocked) 2420 { 2421 2422 KNL_ASSERT_LOCK(knl, islocked); 2423 KQ_NOTOWNED(kn->kn_kq); 2424 KASSERT(kn_in_flux(kn), ("knote %p not in flux", kn)); 2425 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2426 ("knote %p was not detached", kn)); 2427 if (!islocked) 2428 knl->kl_lock(knl->kl_lockarg); 2429 SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext); 2430 if (!islocked) 2431 knl->kl_unlock(knl->kl_lockarg); 2432 KQ_LOCK(kn->kn_kq); 2433 kn->kn_knlist = knl; 2434 kn->kn_status &= ~KN_DETACHED; 2435 KQ_UNLOCK(kn->kn_kq); 2436 } 2437 2438 static void 2439 knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked, 2440 int kqislocked) 2441 { 2442 2443 KASSERT(!kqislocked || knlislocked, ("kq locked w/o knl locked")); 2444 KNL_ASSERT_LOCK(knl, knlislocked); 2445 mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED); 2446 KASSERT(kqislocked || kn_in_flux(kn), ("knote %p not in flux", kn)); 2447 KASSERT((kn->kn_status & KN_DETACHED) == 0, 2448 ("knote %p was already detached", kn)); 2449 if (!knlislocked) 2450 knl->kl_lock(knl->kl_lockarg); 2451 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext); 2452 kn->kn_knlist = NULL; 2453 if (!knlislocked) 2454 kn_list_unlock(knl); 2455 if (!kqislocked) 2456 KQ_LOCK(kn->kn_kq); 2457 kn->kn_status |= KN_DETACHED; 2458 if (!kqislocked) 2459 KQ_UNLOCK(kn->kn_kq); 2460 } 2461 2462 /* 2463 * remove knote from the specified knlist 2464 */ 2465 void 2466 knlist_remove(struct knlist *knl, struct knote *kn, int islocked) 2467 { 2468 2469 knlist_remove_kq(knl, kn, islocked, 0); 2470 } 2471 2472 int 2473 knlist_empty(struct knlist *knl) 2474 { 2475 2476 KNL_ASSERT_LOCKED(knl); 2477 return (SLIST_EMPTY(&knl->kl_list)); 2478 } 2479 2480 static struct mtx knlist_lock; 2481 MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects", 2482 MTX_DEF); 2483 static void knlist_mtx_lock(void *arg); 2484 static void knlist_mtx_unlock(void *arg); 2485 2486 static void 2487 knlist_mtx_lock(void *arg) 2488 { 2489 2490 mtx_lock((struct mtx *)arg); 2491 } 2492 2493 static void 2494 knlist_mtx_unlock(void *arg) 2495 { 2496 2497 mtx_unlock((struct mtx *)arg); 2498 } 2499 2500 static void 2501 knlist_mtx_assert_lock(void *arg, int what) 2502 { 2503 2504 if (what == LA_LOCKED) 2505 mtx_assert((struct mtx *)arg, MA_OWNED); 2506 else 2507 mtx_assert((struct mtx *)arg, MA_NOTOWNED); 2508 } 2509 2510 static void 2511 knlist_rw_rlock(void *arg) 2512 { 2513 2514 rw_rlock((struct rwlock *)arg); 2515 } 2516 2517 static void 2518 knlist_rw_runlock(void *arg) 2519 { 2520 2521 rw_runlock((struct rwlock *)arg); 2522 } 2523 2524 static void 2525 knlist_rw_assert_lock(void *arg, int what) 2526 { 2527 2528 if (what == LA_LOCKED) 2529 rw_assert((struct rwlock *)arg, RA_LOCKED); 2530 else 2531 rw_assert((struct rwlock *)arg, RA_UNLOCKED); 2532 } 2533 2534 void 2535 knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *), 2536 void (*kl_unlock)(void *), 2537 void (*kl_assert_lock)(void *, int)) 2538 { 2539 2540 if (lock == NULL) 2541 knl->kl_lockarg = &knlist_lock; 2542 else 2543 knl->kl_lockarg = lock; 2544 2545 if (kl_lock == NULL) 2546 knl->kl_lock = knlist_mtx_lock; 2547 else 2548 knl->kl_lock = kl_lock; 2549 if (kl_unlock == NULL) 2550 knl->kl_unlock = knlist_mtx_unlock; 2551 else 2552 knl->kl_unlock = kl_unlock; 2553 if (kl_assert_lock == NULL) 2554 knl->kl_assert_lock = knlist_mtx_assert_lock; 2555 else 2556 knl->kl_assert_lock = kl_assert_lock; 2557 2558 knl->kl_autodestroy = 0; 2559 SLIST_INIT(&knl->kl_list); 2560 } 2561 2562 void 2563 knlist_init_mtx(struct knlist *knl, struct mtx *lock) 2564 { 2565 2566 knlist_init(knl, lock, NULL, NULL, NULL); 2567 } 2568 2569 struct knlist * 2570 knlist_alloc(struct mtx *lock) 2571 { 2572 struct knlist *knl; 2573 2574 knl = malloc(sizeof(struct knlist), M_KQUEUE, M_WAITOK); 2575 knlist_init_mtx(knl, lock); 2576 return (knl); 2577 } 2578 2579 void 2580 knlist_init_rw_reader(struct knlist *knl, struct rwlock *lock) 2581 { 2582 2583 knlist_init(knl, lock, knlist_rw_rlock, knlist_rw_runlock, 2584 knlist_rw_assert_lock); 2585 } 2586 2587 void 2588 knlist_destroy(struct knlist *knl) 2589 { 2590 2591 KASSERT(KNLIST_EMPTY(knl), 2592 ("destroying knlist %p with knotes on it", knl)); 2593 } 2594 2595 void 2596 knlist_detach(struct knlist *knl) 2597 { 2598 2599 KNL_ASSERT_LOCKED(knl); 2600 knl->kl_autodestroy = 1; 2601 if (knlist_empty(knl)) { 2602 knlist_destroy(knl); 2603 free(knl, M_KQUEUE); 2604 } 2605 } 2606 2607 /* 2608 * Even if we are locked, we may need to drop the lock to allow any influx 2609 * knotes time to "settle". 2610 */ 2611 void 2612 knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn) 2613 { 2614 struct knote *kn, *kn2; 2615 struct kqueue *kq; 2616 2617 KASSERT(!knl->kl_autodestroy, ("cleardel for autodestroy %p", knl)); 2618 if (islocked) 2619 KNL_ASSERT_LOCKED(knl); 2620 else { 2621 KNL_ASSERT_UNLOCKED(knl); 2622 again: /* need to reacquire lock since we have dropped it */ 2623 knl->kl_lock(knl->kl_lockarg); 2624 } 2625 2626 SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) { 2627 kq = kn->kn_kq; 2628 KQ_LOCK(kq); 2629 if (kn_in_flux(kn)) { 2630 KQ_UNLOCK(kq); 2631 continue; 2632 } 2633 knlist_remove_kq(knl, kn, 1, 1); 2634 if (killkn) { 2635 kn_enter_flux(kn); 2636 KQ_UNLOCK(kq); 2637 knote_drop_detached(kn, td); 2638 } else { 2639 /* Make sure cleared knotes disappear soon */ 2640 kn->kn_flags |= EV_EOF | EV_ONESHOT; 2641 KQ_UNLOCK(kq); 2642 } 2643 kq = NULL; 2644 } 2645 2646 if (!SLIST_EMPTY(&knl->kl_list)) { 2647 /* there are still in flux knotes remaining */ 2648 kn = SLIST_FIRST(&knl->kl_list); 2649 kq = kn->kn_kq; 2650 KQ_LOCK(kq); 2651 KASSERT(kn_in_flux(kn), ("knote removed w/o list lock")); 2652 knl->kl_unlock(knl->kl_lockarg); 2653 kq->kq_state |= KQ_FLUXWAIT; 2654 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0); 2655 kq = NULL; 2656 goto again; 2657 } 2658 2659 if (islocked) 2660 KNL_ASSERT_LOCKED(knl); 2661 else { 2662 knl->kl_unlock(knl->kl_lockarg); 2663 KNL_ASSERT_UNLOCKED(knl); 2664 } 2665 } 2666 2667 /* 2668 * Remove all knotes referencing a specified fd must be called with FILEDESC 2669 * lock. This prevents a race where a new fd comes along and occupies the 2670 * entry and we attach a knote to the fd. 2671 */ 2672 void 2673 knote_fdclose(struct thread *td, int fd) 2674 { 2675 struct filedesc *fdp = td->td_proc->p_fd; 2676 struct kqueue *kq; 2677 struct knote *kn; 2678 int influx; 2679 2680 FILEDESC_XLOCK_ASSERT(fdp); 2681 2682 /* 2683 * We shouldn't have to worry about new kevents appearing on fd 2684 * since filedesc is locked. 2685 */ 2686 TAILQ_FOREACH(kq, &fdp->fd_kqlist, kq_list) { 2687 KQ_LOCK(kq); 2688 2689 again: 2690 influx = 0; 2691 while (kq->kq_knlistsize > fd && 2692 (kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) { 2693 if (kn_in_flux(kn)) { 2694 /* someone else might be waiting on our knote */ 2695 if (influx) 2696 wakeup(kq); 2697 kq->kq_state |= KQ_FLUXWAIT; 2698 msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0); 2699 goto again; 2700 } 2701 kn_enter_flux(kn); 2702 KQ_UNLOCK(kq); 2703 influx = 1; 2704 knote_drop(kn, td); 2705 KQ_LOCK(kq); 2706 } 2707 KQ_UNLOCK_FLUX(kq); 2708 } 2709 } 2710 2711 static int 2712 knote_attach(struct knote *kn, struct kqueue *kq) 2713 { 2714 struct klist *list; 2715 2716 KASSERT(kn_in_flux(kn), ("knote %p not marked influx", kn)); 2717 KQ_OWNED(kq); 2718 2719 if ((kq->kq_state & KQ_CLOSING) != 0) 2720 return (EBADF); 2721 if (kn->kn_fop->f_isfd) { 2722 if (kn->kn_id >= kq->kq_knlistsize) 2723 return (ENOMEM); 2724 list = &kq->kq_knlist[kn->kn_id]; 2725 } else { 2726 if (kq->kq_knhash == NULL) 2727 return (ENOMEM); 2728 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2729 } 2730 SLIST_INSERT_HEAD(list, kn, kn_link); 2731 return (0); 2732 } 2733 2734 static void 2735 knote_drop(struct knote *kn, struct thread *td) 2736 { 2737 2738 if ((kn->kn_status & KN_DETACHED) == 0) 2739 kn->kn_fop->f_detach(kn); 2740 knote_drop_detached(kn, td); 2741 } 2742 2743 static void 2744 knote_drop_detached(struct knote *kn, struct thread *td) 2745 { 2746 struct kqueue *kq; 2747 struct klist *list; 2748 2749 kq = kn->kn_kq; 2750 2751 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2752 ("knote %p still attached", kn)); 2753 KQ_NOTOWNED(kq); 2754 2755 KQ_LOCK(kq); 2756 KASSERT(kn->kn_influx == 1, 2757 ("knote_drop called on %p with influx %d", kn, kn->kn_influx)); 2758 2759 if (kn->kn_fop->f_isfd) 2760 list = &kq->kq_knlist[kn->kn_id]; 2761 else 2762 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2763 2764 if (!SLIST_EMPTY(list)) 2765 SLIST_REMOVE(list, kn, knote, kn_link); 2766 if (kn->kn_status & KN_QUEUED) 2767 knote_dequeue(kn); 2768 KQ_UNLOCK_FLUX(kq); 2769 2770 if (kn->kn_fop->f_isfd) { 2771 fdrop(kn->kn_fp, td); 2772 kn->kn_fp = NULL; 2773 } 2774 kqueue_fo_release(kn->kn_kevent.filter); 2775 kn->kn_fop = NULL; 2776 knote_free(kn); 2777 } 2778 2779 static void 2780 knote_enqueue(struct knote *kn) 2781 { 2782 struct kqueue *kq = kn->kn_kq; 2783 2784 KQ_OWNED(kn->kn_kq); 2785 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 2786 2787 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2788 kn->kn_status |= KN_QUEUED; 2789 kq->kq_count++; 2790 kqueue_wakeup(kq); 2791 } 2792 2793 static void 2794 knote_dequeue(struct knote *kn) 2795 { 2796 struct kqueue *kq = kn->kn_kq; 2797 2798 KQ_OWNED(kn->kn_kq); 2799 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 2800 2801 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 2802 kn->kn_status &= ~KN_QUEUED; 2803 kq->kq_count--; 2804 } 2805 2806 static void 2807 knote_init(void) 2808 { 2809 2810 knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL, 2811 NULL, NULL, UMA_ALIGN_PTR, 0); 2812 } 2813 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL); 2814 2815 static struct knote * 2816 knote_alloc(int mflag) 2817 { 2818 2819 return (uma_zalloc(knote_zone, mflag | M_ZERO)); 2820 } 2821 2822 static void 2823 knote_free(struct knote *kn) 2824 { 2825 2826 uma_zfree(knote_zone, kn); 2827 } 2828 2829 /* 2830 * Register the kev w/ the kq specified by fd. 2831 */ 2832 int 2833 kqfd_register(int fd, struct kevent *kev, struct thread *td, int mflag) 2834 { 2835 struct kqueue *kq; 2836 struct file *fp; 2837 cap_rights_t rights; 2838 int error; 2839 2840 error = fget(td, fd, cap_rights_init_one(&rights, CAP_KQUEUE_CHANGE), 2841 &fp); 2842 if (error != 0) 2843 return (error); 2844 if ((error = kqueue_acquire(fp, &kq)) != 0) 2845 goto noacquire; 2846 2847 error = kqueue_register(kq, kev, td, mflag); 2848 kqueue_release(kq, 0); 2849 2850 noacquire: 2851 fdrop(fp, td); 2852 return (error); 2853 } 2854