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 kq_ncallouts = 0; 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 ((kn->kn_sfflags & NOTE_ABSTIME) != 0) { 802 getboottimebin(&bt); 803 sbt = bttosbt(bt); 804 *to -= sbt; 805 } 806 if (*to < 0) 807 return (EINVAL); 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 unsigned int ncallouts; 817 int error; 818 819 error = filt_timervalidate(kn, &to); 820 if (error != 0) 821 return (error); 822 823 do { 824 ncallouts = kq_ncallouts; 825 if (ncallouts >= kq_calloutmax) 826 return (ENOMEM); 827 } while (!atomic_cmpset_int(&kq_ncallouts, ncallouts, ncallouts + 1)); 828 829 if ((kn->kn_sfflags & NOTE_ABSTIME) == 0) 830 kn->kn_flags |= EV_CLEAR; /* automatically set */ 831 kn->kn_status &= ~KN_DETACHED; /* knlist_add clears it */ 832 kn->kn_ptr.p_v = kc = malloc(sizeof(*kc), M_KQUEUE, M_WAITOK); 833 kc->kn = kn; 834 kc->p = curproc; 835 kc->cpuid = PCPU_GET(cpuid); 836 kc->flags = 0; 837 callout_init(&kc->c, 1); 838 filt_timerstart(kn, to); 839 840 return (0); 841 } 842 843 static void 844 filt_timerstart(struct knote *kn, sbintime_t to) 845 { 846 struct kq_timer_cb_data *kc; 847 848 kc = kn->kn_ptr.p_v; 849 if ((kn->kn_sfflags & NOTE_ABSTIME) != 0) { 850 kc->next = to; 851 kc->to = 0; 852 } else { 853 kc->next = to + sbinuptime(); 854 kc->to = to; 855 } 856 kqtimer_sched_callout(kc); 857 } 858 859 static void 860 filt_timerdetach(struct knote *kn) 861 { 862 struct kq_timer_cb_data *kc; 863 unsigned int old __unused; 864 865 kc = kn->kn_ptr.p_v; 866 callout_drain(&kc->c); 867 if ((kc->flags & KQ_TIMER_CB_ENQUEUED) != 0) { 868 PROC_LOCK(kc->p); 869 TAILQ_REMOVE(&kc->p->p_kqtim_stop, kc, link); 870 PROC_UNLOCK(kc->p); 871 } 872 free(kc, M_KQUEUE); 873 old = atomic_fetchadd_int(&kq_ncallouts, -1); 874 KASSERT(old > 0, ("Number of callouts cannot become negative")); 875 kn->kn_status |= KN_DETACHED; /* knlist_remove sets it */ 876 } 877 878 static void 879 filt_timertouch(struct knote *kn, struct kevent *kev, u_long type) 880 { 881 struct kq_timer_cb_data *kc; 882 struct kqueue *kq; 883 sbintime_t to; 884 int error; 885 886 switch (type) { 887 case EVENT_REGISTER: 888 /* Handle re-added timers that update data/fflags */ 889 if (kev->flags & EV_ADD) { 890 kc = kn->kn_ptr.p_v; 891 892 /* Drain any existing callout. */ 893 callout_drain(&kc->c); 894 895 /* Throw away any existing undelivered record 896 * of the timer expiration. This is done under 897 * the presumption that if a process is 898 * re-adding this timer with new parameters, 899 * it is no longer interested in what may have 900 * happened under the old parameters. If it is 901 * interested, it can wait for the expiration, 902 * delete the old timer definition, and then 903 * add the new one. 904 * 905 * This has to be done while the kq is locked: 906 * - if enqueued, dequeue 907 * - make it no longer active 908 * - clear the count of expiration events 909 */ 910 kq = kn->kn_kq; 911 KQ_LOCK(kq); 912 if (kn->kn_status & KN_QUEUED) 913 knote_dequeue(kn); 914 915 kn->kn_status &= ~KN_ACTIVE; 916 kn->kn_data = 0; 917 KQ_UNLOCK(kq); 918 919 /* Reschedule timer based on new data/fflags */ 920 kn->kn_sfflags = kev->fflags; 921 kn->kn_sdata = kev->data; 922 error = filt_timervalidate(kn, &to); 923 if (error != 0) { 924 kn->kn_flags |= EV_ERROR; 925 kn->kn_data = error; 926 } else 927 filt_timerstart(kn, to); 928 } 929 break; 930 931 case EVENT_PROCESS: 932 *kev = kn->kn_kevent; 933 if (kn->kn_flags & EV_CLEAR) { 934 kn->kn_data = 0; 935 kn->kn_fflags = 0; 936 } 937 break; 938 939 default: 940 panic("filt_timertouch() - invalid type (%ld)", type); 941 break; 942 } 943 } 944 945 static int 946 filt_timer(struct knote *kn, long hint) 947 { 948 949 return (kn->kn_data != 0); 950 } 951 952 static int 953 filt_userattach(struct knote *kn) 954 { 955 956 /* 957 * EVFILT_USER knotes are not attached to anything in the kernel. 958 */ 959 kn->kn_hook = NULL; 960 if (kn->kn_fflags & NOTE_TRIGGER) 961 kn->kn_hookid = 1; 962 else 963 kn->kn_hookid = 0; 964 return (0); 965 } 966 967 static void 968 filt_userdetach(__unused struct knote *kn) 969 { 970 971 /* 972 * EVFILT_USER knotes are not attached to anything in the kernel. 973 */ 974 } 975 976 static int 977 filt_user(struct knote *kn, __unused long hint) 978 { 979 980 return (kn->kn_hookid); 981 } 982 983 static void 984 filt_usertouch(struct knote *kn, struct kevent *kev, u_long type) 985 { 986 u_int ffctrl; 987 988 switch (type) { 989 case EVENT_REGISTER: 990 if (kev->fflags & NOTE_TRIGGER) 991 kn->kn_hookid = 1; 992 993 ffctrl = kev->fflags & NOTE_FFCTRLMASK; 994 kev->fflags &= NOTE_FFLAGSMASK; 995 switch (ffctrl) { 996 case NOTE_FFNOP: 997 break; 998 999 case NOTE_FFAND: 1000 kn->kn_sfflags &= kev->fflags; 1001 break; 1002 1003 case NOTE_FFOR: 1004 kn->kn_sfflags |= kev->fflags; 1005 break; 1006 1007 case NOTE_FFCOPY: 1008 kn->kn_sfflags = kev->fflags; 1009 break; 1010 1011 default: 1012 /* XXX Return error? */ 1013 break; 1014 } 1015 kn->kn_sdata = kev->data; 1016 if (kev->flags & EV_CLEAR) { 1017 kn->kn_hookid = 0; 1018 kn->kn_data = 0; 1019 kn->kn_fflags = 0; 1020 } 1021 break; 1022 1023 case EVENT_PROCESS: 1024 *kev = kn->kn_kevent; 1025 kev->fflags = kn->kn_sfflags; 1026 kev->data = kn->kn_sdata; 1027 if (kn->kn_flags & EV_CLEAR) { 1028 kn->kn_hookid = 0; 1029 kn->kn_data = 0; 1030 kn->kn_fflags = 0; 1031 } 1032 break; 1033 1034 default: 1035 panic("filt_usertouch() - invalid type (%ld)", type); 1036 break; 1037 } 1038 } 1039 1040 int 1041 sys_kqueue(struct thread *td, struct kqueue_args *uap) 1042 { 1043 1044 return (kern_kqueue(td, 0, NULL)); 1045 } 1046 1047 static void 1048 kqueue_init(struct kqueue *kq) 1049 { 1050 1051 mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF | MTX_DUPOK); 1052 TAILQ_INIT(&kq->kq_head); 1053 knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock); 1054 TASK_INIT(&kq->kq_task, 0, kqueue_task, kq); 1055 } 1056 1057 int 1058 kern_kqueue(struct thread *td, int flags, struct filecaps *fcaps) 1059 { 1060 struct filedesc *fdp; 1061 struct kqueue *kq; 1062 struct file *fp; 1063 struct ucred *cred; 1064 int fd, error; 1065 1066 fdp = td->td_proc->p_fd; 1067 cred = td->td_ucred; 1068 if (!chgkqcnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_KQUEUES))) 1069 return (ENOMEM); 1070 1071 error = falloc_caps(td, &fp, &fd, flags, fcaps); 1072 if (error != 0) { 1073 chgkqcnt(cred->cr_ruidinfo, -1, 0); 1074 return (error); 1075 } 1076 1077 /* An extra reference on `fp' has been held for us by falloc(). */ 1078 kq = malloc(sizeof *kq, M_KQUEUE, M_WAITOK | M_ZERO); 1079 kqueue_init(kq); 1080 kq->kq_fdp = fdp; 1081 kq->kq_cred = crhold(cred); 1082 1083 FILEDESC_XLOCK(fdp); 1084 TAILQ_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list); 1085 FILEDESC_XUNLOCK(fdp); 1086 1087 finit(fp, FREAD | FWRITE, DTYPE_KQUEUE, kq, &kqueueops); 1088 fdrop(fp, td); 1089 1090 td->td_retval[0] = fd; 1091 return (0); 1092 } 1093 1094 struct g_kevent_args { 1095 int fd; 1096 void *changelist; 1097 int nchanges; 1098 void *eventlist; 1099 int nevents; 1100 const struct timespec *timeout; 1101 }; 1102 1103 int 1104 sys_kevent(struct thread *td, struct kevent_args *uap) 1105 { 1106 struct kevent_copyops k_ops = { 1107 .arg = uap, 1108 .k_copyout = kevent_copyout, 1109 .k_copyin = kevent_copyin, 1110 .kevent_size = sizeof(struct kevent), 1111 }; 1112 struct g_kevent_args gk_args = { 1113 .fd = uap->fd, 1114 .changelist = uap->changelist, 1115 .nchanges = uap->nchanges, 1116 .eventlist = uap->eventlist, 1117 .nevents = uap->nevents, 1118 .timeout = uap->timeout, 1119 }; 1120 1121 return (kern_kevent_generic(td, &gk_args, &k_ops, "kevent")); 1122 } 1123 1124 static int 1125 kern_kevent_generic(struct thread *td, struct g_kevent_args *uap, 1126 struct kevent_copyops *k_ops, const char *struct_name) 1127 { 1128 struct timespec ts, *tsp; 1129 #ifdef KTRACE 1130 struct kevent *eventlist = uap->eventlist; 1131 #endif 1132 int error; 1133 1134 if (uap->timeout != NULL) { 1135 error = copyin(uap->timeout, &ts, sizeof(ts)); 1136 if (error) 1137 return (error); 1138 tsp = &ts; 1139 } else 1140 tsp = NULL; 1141 1142 #ifdef KTRACE 1143 if (KTRPOINT(td, KTR_STRUCT_ARRAY)) 1144 ktrstructarray(struct_name, UIO_USERSPACE, uap->changelist, 1145 uap->nchanges, k_ops->kevent_size); 1146 #endif 1147 1148 error = kern_kevent(td, uap->fd, uap->nchanges, uap->nevents, 1149 k_ops, tsp); 1150 1151 #ifdef KTRACE 1152 if (error == 0 && KTRPOINT(td, KTR_STRUCT_ARRAY)) 1153 ktrstructarray(struct_name, UIO_USERSPACE, eventlist, 1154 td->td_retval[0], k_ops->kevent_size); 1155 #endif 1156 1157 return (error); 1158 } 1159 1160 /* 1161 * Copy 'count' items into the destination list pointed to by uap->eventlist. 1162 */ 1163 static int 1164 kevent_copyout(void *arg, struct kevent *kevp, int count) 1165 { 1166 struct kevent_args *uap; 1167 int error; 1168 1169 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1170 uap = (struct kevent_args *)arg; 1171 1172 error = copyout(kevp, uap->eventlist, count * sizeof *kevp); 1173 if (error == 0) 1174 uap->eventlist += count; 1175 return (error); 1176 } 1177 1178 /* 1179 * Copy 'count' items from the list pointed to by uap->changelist. 1180 */ 1181 static int 1182 kevent_copyin(void *arg, struct kevent *kevp, int count) 1183 { 1184 struct kevent_args *uap; 1185 int error; 1186 1187 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1188 uap = (struct kevent_args *)arg; 1189 1190 error = copyin(uap->changelist, kevp, count * sizeof *kevp); 1191 if (error == 0) 1192 uap->changelist += count; 1193 return (error); 1194 } 1195 1196 #ifdef COMPAT_FREEBSD11 1197 static int 1198 kevent11_copyout(void *arg, struct kevent *kevp, int count) 1199 { 1200 struct freebsd11_kevent_args *uap; 1201 struct kevent_freebsd11 kev11; 1202 int error, i; 1203 1204 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1205 uap = (struct freebsd11_kevent_args *)arg; 1206 1207 for (i = 0; i < count; i++) { 1208 kev11.ident = kevp->ident; 1209 kev11.filter = kevp->filter; 1210 kev11.flags = kevp->flags; 1211 kev11.fflags = kevp->fflags; 1212 kev11.data = kevp->data; 1213 kev11.udata = kevp->udata; 1214 error = copyout(&kev11, uap->eventlist, sizeof(kev11)); 1215 if (error != 0) 1216 break; 1217 uap->eventlist++; 1218 kevp++; 1219 } 1220 return (error); 1221 } 1222 1223 /* 1224 * Copy 'count' items from the list pointed to by uap->changelist. 1225 */ 1226 static int 1227 kevent11_copyin(void *arg, struct kevent *kevp, int count) 1228 { 1229 struct freebsd11_kevent_args *uap; 1230 struct kevent_freebsd11 kev11; 1231 int error, i; 1232 1233 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1234 uap = (struct freebsd11_kevent_args *)arg; 1235 1236 for (i = 0; i < count; i++) { 1237 error = copyin(uap->changelist, &kev11, sizeof(kev11)); 1238 if (error != 0) 1239 break; 1240 kevp->ident = kev11.ident; 1241 kevp->filter = kev11.filter; 1242 kevp->flags = kev11.flags; 1243 kevp->fflags = kev11.fflags; 1244 kevp->data = (uintptr_t)kev11.data; 1245 kevp->udata = kev11.udata; 1246 bzero(&kevp->ext, sizeof(kevp->ext)); 1247 uap->changelist++; 1248 kevp++; 1249 } 1250 return (error); 1251 } 1252 1253 int 1254 freebsd11_kevent(struct thread *td, struct freebsd11_kevent_args *uap) 1255 { 1256 struct kevent_copyops k_ops = { 1257 .arg = uap, 1258 .k_copyout = kevent11_copyout, 1259 .k_copyin = kevent11_copyin, 1260 .kevent_size = sizeof(struct kevent_freebsd11), 1261 }; 1262 struct g_kevent_args gk_args = { 1263 .fd = uap->fd, 1264 .changelist = uap->changelist, 1265 .nchanges = uap->nchanges, 1266 .eventlist = uap->eventlist, 1267 .nevents = uap->nevents, 1268 .timeout = uap->timeout, 1269 }; 1270 1271 return (kern_kevent_generic(td, &gk_args, &k_ops, "kevent_freebsd11")); 1272 } 1273 #endif 1274 1275 int 1276 kern_kevent(struct thread *td, int fd, int nchanges, int nevents, 1277 struct kevent_copyops *k_ops, const struct timespec *timeout) 1278 { 1279 cap_rights_t rights; 1280 struct file *fp; 1281 int error; 1282 1283 cap_rights_init_zero(&rights); 1284 if (nchanges > 0) 1285 cap_rights_set_one(&rights, CAP_KQUEUE_CHANGE); 1286 if (nevents > 0) 1287 cap_rights_set_one(&rights, CAP_KQUEUE_EVENT); 1288 error = fget(td, fd, &rights, &fp); 1289 if (error != 0) 1290 return (error); 1291 1292 error = kern_kevent_fp(td, fp, nchanges, nevents, k_ops, timeout); 1293 fdrop(fp, td); 1294 1295 return (error); 1296 } 1297 1298 static int 1299 kqueue_kevent(struct kqueue *kq, struct thread *td, int nchanges, int nevents, 1300 struct kevent_copyops *k_ops, const struct timespec *timeout) 1301 { 1302 struct kevent keva[KQ_NEVENTS]; 1303 struct kevent *kevp, *changes; 1304 int i, n, nerrors, error; 1305 1306 if (nchanges < 0) 1307 return (EINVAL); 1308 1309 nerrors = 0; 1310 while (nchanges > 0) { 1311 n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges; 1312 error = k_ops->k_copyin(k_ops->arg, keva, n); 1313 if (error) 1314 return (error); 1315 changes = keva; 1316 for (i = 0; i < n; i++) { 1317 kevp = &changes[i]; 1318 if (!kevp->filter) 1319 continue; 1320 kevp->flags &= ~EV_SYSFLAGS; 1321 error = kqueue_register(kq, kevp, td, M_WAITOK); 1322 if (error || (kevp->flags & EV_RECEIPT)) { 1323 if (nevents == 0) 1324 return (error); 1325 kevp->flags = EV_ERROR; 1326 kevp->data = error; 1327 (void)k_ops->k_copyout(k_ops->arg, kevp, 1); 1328 nevents--; 1329 nerrors++; 1330 } 1331 } 1332 nchanges -= n; 1333 } 1334 if (nerrors) { 1335 td->td_retval[0] = nerrors; 1336 return (0); 1337 } 1338 1339 return (kqueue_scan(kq, nevents, k_ops, timeout, keva, td)); 1340 } 1341 1342 int 1343 kern_kevent_fp(struct thread *td, struct file *fp, int nchanges, int nevents, 1344 struct kevent_copyops *k_ops, const struct timespec *timeout) 1345 { 1346 struct kqueue *kq; 1347 int error; 1348 1349 error = kqueue_acquire(fp, &kq); 1350 if (error != 0) 1351 return (error); 1352 error = kqueue_kevent(kq, td, nchanges, nevents, k_ops, timeout); 1353 kqueue_release(kq, 0); 1354 return (error); 1355 } 1356 1357 /* 1358 * Performs a kevent() call on a temporarily created kqueue. This can be 1359 * used to perform one-shot polling, similar to poll() and select(). 1360 */ 1361 int 1362 kern_kevent_anonymous(struct thread *td, int nevents, 1363 struct kevent_copyops *k_ops) 1364 { 1365 struct kqueue kq = {}; 1366 int error; 1367 1368 kqueue_init(&kq); 1369 kq.kq_refcnt = 1; 1370 error = kqueue_kevent(&kq, td, nevents, nevents, k_ops, NULL); 1371 kqueue_drain(&kq, td); 1372 kqueue_destroy(&kq); 1373 return (error); 1374 } 1375 1376 int 1377 kqueue_add_filteropts(int filt, struct filterops *filtops) 1378 { 1379 int error; 1380 1381 error = 0; 1382 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) { 1383 printf( 1384 "trying to add a filterop that is out of range: %d is beyond %d\n", 1385 ~filt, EVFILT_SYSCOUNT); 1386 return EINVAL; 1387 } 1388 mtx_lock(&filterops_lock); 1389 if (sysfilt_ops[~filt].for_fop != &null_filtops && 1390 sysfilt_ops[~filt].for_fop != NULL) 1391 error = EEXIST; 1392 else { 1393 sysfilt_ops[~filt].for_fop = filtops; 1394 sysfilt_ops[~filt].for_refcnt = 0; 1395 } 1396 mtx_unlock(&filterops_lock); 1397 1398 return (error); 1399 } 1400 1401 int 1402 kqueue_del_filteropts(int filt) 1403 { 1404 int error; 1405 1406 error = 0; 1407 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1408 return EINVAL; 1409 1410 mtx_lock(&filterops_lock); 1411 if (sysfilt_ops[~filt].for_fop == &null_filtops || 1412 sysfilt_ops[~filt].for_fop == NULL) 1413 error = EINVAL; 1414 else if (sysfilt_ops[~filt].for_refcnt != 0) 1415 error = EBUSY; 1416 else { 1417 sysfilt_ops[~filt].for_fop = &null_filtops; 1418 sysfilt_ops[~filt].for_refcnt = 0; 1419 } 1420 mtx_unlock(&filterops_lock); 1421 1422 return error; 1423 } 1424 1425 static struct filterops * 1426 kqueue_fo_find(int filt) 1427 { 1428 1429 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1430 return NULL; 1431 1432 if (sysfilt_ops[~filt].for_nolock) 1433 return sysfilt_ops[~filt].for_fop; 1434 1435 mtx_lock(&filterops_lock); 1436 sysfilt_ops[~filt].for_refcnt++; 1437 if (sysfilt_ops[~filt].for_fop == NULL) 1438 sysfilt_ops[~filt].for_fop = &null_filtops; 1439 mtx_unlock(&filterops_lock); 1440 1441 return sysfilt_ops[~filt].for_fop; 1442 } 1443 1444 static void 1445 kqueue_fo_release(int filt) 1446 { 1447 1448 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1449 return; 1450 1451 if (sysfilt_ops[~filt].for_nolock) 1452 return; 1453 1454 mtx_lock(&filterops_lock); 1455 KASSERT(sysfilt_ops[~filt].for_refcnt > 0, 1456 ("filter object refcount not valid on release")); 1457 sysfilt_ops[~filt].for_refcnt--; 1458 mtx_unlock(&filterops_lock); 1459 } 1460 1461 /* 1462 * A ref to kq (obtained via kqueue_acquire) must be held. 1463 */ 1464 static int 1465 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, 1466 int mflag) 1467 { 1468 struct filterops *fops; 1469 struct file *fp; 1470 struct knote *kn, *tkn; 1471 struct knlist *knl; 1472 int error, filt, event; 1473 int haskqglobal, filedesc_unlock; 1474 1475 if ((kev->flags & (EV_ENABLE | EV_DISABLE)) == (EV_ENABLE | EV_DISABLE)) 1476 return (EINVAL); 1477 1478 fp = NULL; 1479 kn = NULL; 1480 knl = NULL; 1481 error = 0; 1482 haskqglobal = 0; 1483 filedesc_unlock = 0; 1484 1485 filt = kev->filter; 1486 fops = kqueue_fo_find(filt); 1487 if (fops == NULL) 1488 return EINVAL; 1489 1490 if (kev->flags & EV_ADD) { 1491 /* 1492 * Prevent waiting with locks. Non-sleepable 1493 * allocation failures are handled in the loop, only 1494 * if the spare knote appears to be actually required. 1495 */ 1496 tkn = knote_alloc(mflag); 1497 } else { 1498 tkn = NULL; 1499 } 1500 1501 findkn: 1502 if (fops->f_isfd) { 1503 KASSERT(td != NULL, ("td is NULL")); 1504 if (kev->ident > INT_MAX) 1505 error = EBADF; 1506 else 1507 error = fget(td, kev->ident, &cap_event_rights, &fp); 1508 if (error) 1509 goto done; 1510 1511 if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops, 1512 kev->ident, M_NOWAIT) != 0) { 1513 /* try again */ 1514 fdrop(fp, td); 1515 fp = NULL; 1516 error = kqueue_expand(kq, fops, kev->ident, mflag); 1517 if (error) 1518 goto done; 1519 goto findkn; 1520 } 1521 1522 if (fp->f_type == DTYPE_KQUEUE) { 1523 /* 1524 * If we add some intelligence about what we are doing, 1525 * we should be able to support events on ourselves. 1526 * We need to know when we are doing this to prevent 1527 * getting both the knlist lock and the kq lock since 1528 * they are the same thing. 1529 */ 1530 if (fp->f_data == kq) { 1531 error = EINVAL; 1532 goto done; 1533 } 1534 1535 /* 1536 * Pre-lock the filedesc before the global 1537 * lock mutex, see the comment in 1538 * kqueue_close(). 1539 */ 1540 FILEDESC_XLOCK(td->td_proc->p_fd); 1541 filedesc_unlock = 1; 1542 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1543 } 1544 1545 KQ_LOCK(kq); 1546 if (kev->ident < kq->kq_knlistsize) { 1547 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link) 1548 if (kev->filter == kn->kn_filter) 1549 break; 1550 } 1551 } else { 1552 if ((kev->flags & EV_ADD) == EV_ADD) { 1553 error = kqueue_expand(kq, fops, kev->ident, mflag); 1554 if (error != 0) 1555 goto done; 1556 } 1557 1558 KQ_LOCK(kq); 1559 1560 /* 1561 * If possible, find an existing knote to use for this kevent. 1562 */ 1563 if (kev->filter == EVFILT_PROC && 1564 (kev->flags & (EV_FLAG1 | EV_FLAG2)) != 0) { 1565 /* This is an internal creation of a process tracking 1566 * note. Don't attempt to coalesce this with an 1567 * existing note. 1568 */ 1569 ; 1570 } else if (kq->kq_knhashmask != 0) { 1571 struct klist *list; 1572 1573 list = &kq->kq_knhash[ 1574 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)]; 1575 SLIST_FOREACH(kn, list, kn_link) 1576 if (kev->ident == kn->kn_id && 1577 kev->filter == kn->kn_filter) 1578 break; 1579 } 1580 } 1581 1582 /* knote is in the process of changing, wait for it to stabilize. */ 1583 if (kn != NULL && kn_in_flux(kn)) { 1584 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1585 if (filedesc_unlock) { 1586 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1587 filedesc_unlock = 0; 1588 } 1589 kq->kq_state |= KQ_FLUXWAIT; 1590 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0); 1591 if (fp != NULL) { 1592 fdrop(fp, td); 1593 fp = NULL; 1594 } 1595 goto findkn; 1596 } 1597 1598 /* 1599 * kn now contains the matching knote, or NULL if no match 1600 */ 1601 if (kn == NULL) { 1602 if (kev->flags & EV_ADD) { 1603 kn = tkn; 1604 tkn = NULL; 1605 if (kn == NULL) { 1606 KQ_UNLOCK(kq); 1607 error = ENOMEM; 1608 goto done; 1609 } 1610 kn->kn_fp = fp; 1611 kn->kn_kq = kq; 1612 kn->kn_fop = fops; 1613 /* 1614 * apply reference counts to knote structure, and 1615 * do not release it at the end of this routine. 1616 */ 1617 fops = NULL; 1618 fp = NULL; 1619 1620 kn->kn_sfflags = kev->fflags; 1621 kn->kn_sdata = kev->data; 1622 kev->fflags = 0; 1623 kev->data = 0; 1624 kn->kn_kevent = *kev; 1625 kn->kn_kevent.flags &= ~(EV_ADD | EV_DELETE | 1626 EV_ENABLE | EV_DISABLE | EV_FORCEONESHOT); 1627 kn->kn_status = KN_DETACHED; 1628 if ((kev->flags & EV_DISABLE) != 0) 1629 kn->kn_status |= KN_DISABLED; 1630 kn_enter_flux(kn); 1631 1632 error = knote_attach(kn, kq); 1633 KQ_UNLOCK(kq); 1634 if (error != 0) { 1635 tkn = kn; 1636 goto done; 1637 } 1638 1639 if ((error = kn->kn_fop->f_attach(kn)) != 0) { 1640 knote_drop_detached(kn, td); 1641 goto done; 1642 } 1643 knl = kn_list_lock(kn); 1644 goto done_ev_add; 1645 } else { 1646 /* No matching knote and the EV_ADD flag is not set. */ 1647 KQ_UNLOCK(kq); 1648 error = ENOENT; 1649 goto done; 1650 } 1651 } 1652 1653 if (kev->flags & EV_DELETE) { 1654 kn_enter_flux(kn); 1655 KQ_UNLOCK(kq); 1656 knote_drop(kn, td); 1657 goto done; 1658 } 1659 1660 if (kev->flags & EV_FORCEONESHOT) { 1661 kn->kn_flags |= EV_ONESHOT; 1662 KNOTE_ACTIVATE(kn, 1); 1663 } 1664 1665 if ((kev->flags & EV_ENABLE) != 0) 1666 kn->kn_status &= ~KN_DISABLED; 1667 else if ((kev->flags & EV_DISABLE) != 0) 1668 kn->kn_status |= KN_DISABLED; 1669 1670 /* 1671 * The user may change some filter values after the initial EV_ADD, 1672 * but doing so will not reset any filter which has already been 1673 * triggered. 1674 */ 1675 kn->kn_status |= KN_SCAN; 1676 kn_enter_flux(kn); 1677 KQ_UNLOCK(kq); 1678 knl = kn_list_lock(kn); 1679 kn->kn_kevent.udata = kev->udata; 1680 if (!fops->f_isfd && fops->f_touch != NULL) { 1681 fops->f_touch(kn, kev, EVENT_REGISTER); 1682 } else { 1683 kn->kn_sfflags = kev->fflags; 1684 kn->kn_sdata = kev->data; 1685 } 1686 1687 done_ev_add: 1688 /* 1689 * We can get here with kn->kn_knlist == NULL. This can happen when 1690 * the initial attach event decides that the event is "completed" 1691 * already, e.g., filt_procattach() is called on a zombie process. It 1692 * will call filt_proc() which will remove it from the list, and NULL 1693 * kn_knlist. 1694 * 1695 * KN_DISABLED will be stable while the knote is in flux, so the 1696 * unlocked read will not race with an update. 1697 */ 1698 if ((kn->kn_status & KN_DISABLED) == 0) 1699 event = kn->kn_fop->f_event(kn, 0); 1700 else 1701 event = 0; 1702 1703 KQ_LOCK(kq); 1704 if (event) 1705 kn->kn_status |= KN_ACTIVE; 1706 if ((kn->kn_status & (KN_ACTIVE | KN_DISABLED | KN_QUEUED)) == 1707 KN_ACTIVE) 1708 knote_enqueue(kn); 1709 kn->kn_status &= ~KN_SCAN; 1710 kn_leave_flux(kn); 1711 kn_list_unlock(knl); 1712 KQ_UNLOCK_FLUX(kq); 1713 1714 done: 1715 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1716 if (filedesc_unlock) 1717 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1718 if (fp != NULL) 1719 fdrop(fp, td); 1720 knote_free(tkn); 1721 if (fops != NULL) 1722 kqueue_fo_release(filt); 1723 return (error); 1724 } 1725 1726 static int 1727 kqueue_acquire(struct file *fp, struct kqueue **kqp) 1728 { 1729 int error; 1730 struct kqueue *kq; 1731 1732 error = 0; 1733 1734 kq = fp->f_data; 1735 if (fp->f_type != DTYPE_KQUEUE || kq == NULL) 1736 return (EBADF); 1737 *kqp = kq; 1738 KQ_LOCK(kq); 1739 if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) { 1740 KQ_UNLOCK(kq); 1741 return (EBADF); 1742 } 1743 kq->kq_refcnt++; 1744 KQ_UNLOCK(kq); 1745 1746 return error; 1747 } 1748 1749 static void 1750 kqueue_release(struct kqueue *kq, int locked) 1751 { 1752 if (locked) 1753 KQ_OWNED(kq); 1754 else 1755 KQ_LOCK(kq); 1756 kq->kq_refcnt--; 1757 if (kq->kq_refcnt == 1) 1758 wakeup(&kq->kq_refcnt); 1759 if (!locked) 1760 KQ_UNLOCK(kq); 1761 } 1762 1763 static void 1764 kqueue_schedtask(struct kqueue *kq) 1765 { 1766 1767 KQ_OWNED(kq); 1768 KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN), 1769 ("scheduling kqueue task while draining")); 1770 1771 if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) { 1772 taskqueue_enqueue(taskqueue_kqueue_ctx, &kq->kq_task); 1773 kq->kq_state |= KQ_TASKSCHED; 1774 } 1775 } 1776 1777 /* 1778 * Expand the kq to make sure we have storage for fops/ident pair. 1779 * 1780 * Return 0 on success (or no work necessary), return errno on failure. 1781 */ 1782 static int 1783 kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident, 1784 int mflag) 1785 { 1786 struct klist *list, *tmp_knhash, *to_free; 1787 u_long tmp_knhashmask; 1788 int error, fd, size; 1789 1790 KQ_NOTOWNED(kq); 1791 1792 error = 0; 1793 to_free = NULL; 1794 if (fops->f_isfd) { 1795 fd = ident; 1796 if (kq->kq_knlistsize <= fd) { 1797 size = kq->kq_knlistsize; 1798 while (size <= fd) 1799 size += KQEXTENT; 1800 list = malloc(size * sizeof(*list), M_KQUEUE, mflag); 1801 if (list == NULL) 1802 return ENOMEM; 1803 KQ_LOCK(kq); 1804 if ((kq->kq_state & KQ_CLOSING) != 0) { 1805 to_free = list; 1806 error = EBADF; 1807 } else if (kq->kq_knlistsize > fd) { 1808 to_free = list; 1809 } else { 1810 if (kq->kq_knlist != NULL) { 1811 bcopy(kq->kq_knlist, list, 1812 kq->kq_knlistsize * sizeof(*list)); 1813 to_free = kq->kq_knlist; 1814 kq->kq_knlist = NULL; 1815 } 1816 bzero((caddr_t)list + 1817 kq->kq_knlistsize * sizeof(*list), 1818 (size - kq->kq_knlistsize) * sizeof(*list)); 1819 kq->kq_knlistsize = size; 1820 kq->kq_knlist = list; 1821 } 1822 KQ_UNLOCK(kq); 1823 } 1824 } else { 1825 if (kq->kq_knhashmask == 0) { 1826 tmp_knhash = hashinit_flags(KN_HASHSIZE, M_KQUEUE, 1827 &tmp_knhashmask, (mflag & M_WAITOK) != 0 ? 1828 HASH_WAITOK : HASH_NOWAIT); 1829 if (tmp_knhash == NULL) 1830 return (ENOMEM); 1831 KQ_LOCK(kq); 1832 if ((kq->kq_state & KQ_CLOSING) != 0) { 1833 to_free = tmp_knhash; 1834 error = EBADF; 1835 } else if (kq->kq_knhashmask == 0) { 1836 kq->kq_knhash = tmp_knhash; 1837 kq->kq_knhashmask = tmp_knhashmask; 1838 } else { 1839 to_free = tmp_knhash; 1840 } 1841 KQ_UNLOCK(kq); 1842 } 1843 } 1844 free(to_free, M_KQUEUE); 1845 1846 KQ_NOTOWNED(kq); 1847 return (error); 1848 } 1849 1850 static void 1851 kqueue_task(void *arg, int pending) 1852 { 1853 struct kqueue *kq; 1854 int haskqglobal; 1855 1856 haskqglobal = 0; 1857 kq = arg; 1858 1859 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1860 KQ_LOCK(kq); 1861 1862 KNOTE_LOCKED(&kq->kq_sel.si_note, 0); 1863 1864 kq->kq_state &= ~KQ_TASKSCHED; 1865 if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) { 1866 wakeup(&kq->kq_state); 1867 } 1868 KQ_UNLOCK(kq); 1869 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1870 } 1871 1872 /* 1873 * Scan, update kn_data (if not ONESHOT), and copyout triggered events. 1874 * We treat KN_MARKER knotes as if they are in flux. 1875 */ 1876 static int 1877 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops, 1878 const struct timespec *tsp, struct kevent *keva, struct thread *td) 1879 { 1880 struct kevent *kevp; 1881 struct knote *kn, *marker; 1882 struct knlist *knl; 1883 sbintime_t asbt, rsbt; 1884 int count, error, haskqglobal, influx, nkev, touch; 1885 1886 count = maxevents; 1887 nkev = 0; 1888 error = 0; 1889 haskqglobal = 0; 1890 1891 if (maxevents == 0) 1892 goto done_nl; 1893 if (maxevents < 0) { 1894 error = EINVAL; 1895 goto done_nl; 1896 } 1897 1898 rsbt = 0; 1899 if (tsp != NULL) { 1900 if (tsp->tv_sec < 0 || tsp->tv_nsec < 0 || 1901 tsp->tv_nsec >= 1000000000) { 1902 error = EINVAL; 1903 goto done_nl; 1904 } 1905 if (timespecisset(tsp)) { 1906 if (tsp->tv_sec <= INT32_MAX) { 1907 rsbt = tstosbt(*tsp); 1908 if (TIMESEL(&asbt, rsbt)) 1909 asbt += tc_tick_sbt; 1910 if (asbt <= SBT_MAX - rsbt) 1911 asbt += rsbt; 1912 else 1913 asbt = 0; 1914 rsbt >>= tc_precexp; 1915 } else 1916 asbt = 0; 1917 } else 1918 asbt = -1; 1919 } else 1920 asbt = 0; 1921 marker = knote_alloc(M_WAITOK); 1922 marker->kn_status = KN_MARKER; 1923 KQ_LOCK(kq); 1924 1925 retry: 1926 kevp = keva; 1927 if (kq->kq_count == 0) { 1928 if (asbt == -1) { 1929 error = EWOULDBLOCK; 1930 } else { 1931 kq->kq_state |= KQ_SLEEP; 1932 error = msleep_sbt(kq, &kq->kq_lock, PSOCK | PCATCH, 1933 "kqread", asbt, rsbt, C_ABSOLUTE); 1934 } 1935 if (error == 0) 1936 goto retry; 1937 /* don't restart after signals... */ 1938 if (error == ERESTART) 1939 error = EINTR; 1940 else if (error == EWOULDBLOCK) 1941 error = 0; 1942 goto done; 1943 } 1944 1945 TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); 1946 influx = 0; 1947 while (count) { 1948 KQ_OWNED(kq); 1949 kn = TAILQ_FIRST(&kq->kq_head); 1950 1951 if ((kn->kn_status == KN_MARKER && kn != marker) || 1952 kn_in_flux(kn)) { 1953 if (influx) { 1954 influx = 0; 1955 KQ_FLUX_WAKEUP(kq); 1956 } 1957 kq->kq_state |= KQ_FLUXWAIT; 1958 error = msleep(kq, &kq->kq_lock, PSOCK, 1959 "kqflxwt", 0); 1960 continue; 1961 } 1962 1963 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1964 if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) { 1965 kn->kn_status &= ~KN_QUEUED; 1966 kq->kq_count--; 1967 continue; 1968 } 1969 if (kn == marker) { 1970 KQ_FLUX_WAKEUP(kq); 1971 if (count == maxevents) 1972 goto retry; 1973 goto done; 1974 } 1975 KASSERT(!kn_in_flux(kn), 1976 ("knote %p is unexpectedly in flux", kn)); 1977 1978 if ((kn->kn_flags & EV_DROP) == EV_DROP) { 1979 kn->kn_status &= ~KN_QUEUED; 1980 kn_enter_flux(kn); 1981 kq->kq_count--; 1982 KQ_UNLOCK(kq); 1983 /* 1984 * We don't need to lock the list since we've 1985 * marked it as in flux. 1986 */ 1987 knote_drop(kn, td); 1988 KQ_LOCK(kq); 1989 continue; 1990 } else if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) { 1991 kn->kn_status &= ~KN_QUEUED; 1992 kn_enter_flux(kn); 1993 kq->kq_count--; 1994 KQ_UNLOCK(kq); 1995 /* 1996 * We don't need to lock the list since we've 1997 * marked the knote as being in flux. 1998 */ 1999 *kevp = kn->kn_kevent; 2000 knote_drop(kn, td); 2001 KQ_LOCK(kq); 2002 kn = NULL; 2003 } else { 2004 kn->kn_status |= KN_SCAN; 2005 kn_enter_flux(kn); 2006 KQ_UNLOCK(kq); 2007 if ((kn->kn_status & KN_KQUEUE) == KN_KQUEUE) 2008 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 2009 knl = kn_list_lock(kn); 2010 if (kn->kn_fop->f_event(kn, 0) == 0) { 2011 KQ_LOCK(kq); 2012 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 2013 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE | 2014 KN_SCAN); 2015 kn_leave_flux(kn); 2016 kq->kq_count--; 2017 kn_list_unlock(knl); 2018 influx = 1; 2019 continue; 2020 } 2021 touch = (!kn->kn_fop->f_isfd && 2022 kn->kn_fop->f_touch != NULL); 2023 if (touch) 2024 kn->kn_fop->f_touch(kn, kevp, EVENT_PROCESS); 2025 else 2026 *kevp = kn->kn_kevent; 2027 KQ_LOCK(kq); 2028 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 2029 if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) { 2030 /* 2031 * Manually clear knotes who weren't 2032 * 'touch'ed. 2033 */ 2034 if (touch == 0 && kn->kn_flags & EV_CLEAR) { 2035 kn->kn_data = 0; 2036 kn->kn_fflags = 0; 2037 } 2038 if (kn->kn_flags & EV_DISPATCH) 2039 kn->kn_status |= KN_DISABLED; 2040 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 2041 kq->kq_count--; 2042 } else 2043 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2044 2045 kn->kn_status &= ~KN_SCAN; 2046 kn_leave_flux(kn); 2047 kn_list_unlock(knl); 2048 influx = 1; 2049 } 2050 2051 /* we are returning a copy to the user */ 2052 kevp++; 2053 nkev++; 2054 count--; 2055 2056 if (nkev == KQ_NEVENTS) { 2057 influx = 0; 2058 KQ_UNLOCK_FLUX(kq); 2059 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 2060 nkev = 0; 2061 kevp = keva; 2062 KQ_LOCK(kq); 2063 if (error) 2064 break; 2065 } 2066 } 2067 TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); 2068 done: 2069 KQ_OWNED(kq); 2070 KQ_UNLOCK_FLUX(kq); 2071 knote_free(marker); 2072 done_nl: 2073 KQ_NOTOWNED(kq); 2074 if (nkev != 0) 2075 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 2076 td->td_retval[0] = maxevents - count; 2077 return (error); 2078 } 2079 2080 /*ARGSUSED*/ 2081 static int 2082 kqueue_ioctl(struct file *fp, u_long cmd, void *data, 2083 struct ucred *active_cred, struct thread *td) 2084 { 2085 /* 2086 * Enabling sigio causes two major problems: 2087 * 1) infinite recursion: 2088 * Synopsys: kevent is being used to track signals and have FIOASYNC 2089 * set. On receipt of a signal this will cause a kqueue to recurse 2090 * into itself over and over. Sending the sigio causes the kqueue 2091 * to become ready, which in turn posts sigio again, forever. 2092 * Solution: this can be solved by setting a flag in the kqueue that 2093 * we have a SIGIO in progress. 2094 * 2) locking problems: 2095 * Synopsys: Kqueue is a leaf subsystem, but adding signalling puts 2096 * us above the proc and pgrp locks. 2097 * Solution: Post a signal using an async mechanism, being sure to 2098 * record a generation count in the delivery so that we do not deliver 2099 * a signal to the wrong process. 2100 * 2101 * Note, these two mechanisms are somewhat mutually exclusive! 2102 */ 2103 #if 0 2104 struct kqueue *kq; 2105 2106 kq = fp->f_data; 2107 switch (cmd) { 2108 case FIOASYNC: 2109 if (*(int *)data) { 2110 kq->kq_state |= KQ_ASYNC; 2111 } else { 2112 kq->kq_state &= ~KQ_ASYNC; 2113 } 2114 return (0); 2115 2116 case FIOSETOWN: 2117 return (fsetown(*(int *)data, &kq->kq_sigio)); 2118 2119 case FIOGETOWN: 2120 *(int *)data = fgetown(&kq->kq_sigio); 2121 return (0); 2122 } 2123 #endif 2124 2125 return (ENOTTY); 2126 } 2127 2128 /*ARGSUSED*/ 2129 static int 2130 kqueue_poll(struct file *fp, int events, struct ucred *active_cred, 2131 struct thread *td) 2132 { 2133 struct kqueue *kq; 2134 int revents = 0; 2135 int error; 2136 2137 if ((error = kqueue_acquire(fp, &kq))) 2138 return POLLERR; 2139 2140 KQ_LOCK(kq); 2141 if (events & (POLLIN | POLLRDNORM)) { 2142 if (kq->kq_count) { 2143 revents |= events & (POLLIN | POLLRDNORM); 2144 } else { 2145 selrecord(td, &kq->kq_sel); 2146 if (SEL_WAITING(&kq->kq_sel)) 2147 kq->kq_state |= KQ_SEL; 2148 } 2149 } 2150 kqueue_release(kq, 1); 2151 KQ_UNLOCK(kq); 2152 return (revents); 2153 } 2154 2155 /*ARGSUSED*/ 2156 static int 2157 kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred, 2158 struct thread *td) 2159 { 2160 2161 bzero((void *)st, sizeof *st); 2162 /* 2163 * We no longer return kq_count because the unlocked value is useless. 2164 * If you spent all this time getting the count, why not spend your 2165 * syscall better by calling kevent? 2166 * 2167 * XXX - This is needed for libc_r. 2168 */ 2169 st->st_mode = S_IFIFO; 2170 return (0); 2171 } 2172 2173 static void 2174 kqueue_drain(struct kqueue *kq, struct thread *td) 2175 { 2176 struct knote *kn; 2177 int i; 2178 2179 KQ_LOCK(kq); 2180 2181 KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING, 2182 ("kqueue already closing")); 2183 kq->kq_state |= KQ_CLOSING; 2184 if (kq->kq_refcnt > 1) 2185 msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0); 2186 2187 KASSERT(kq->kq_refcnt == 1, ("other refs are out there!")); 2188 2189 KASSERT(knlist_empty(&kq->kq_sel.si_note), 2190 ("kqueue's knlist not empty")); 2191 2192 for (i = 0; i < kq->kq_knlistsize; i++) { 2193 while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) { 2194 if (kn_in_flux(kn)) { 2195 kq->kq_state |= KQ_FLUXWAIT; 2196 msleep(kq, &kq->kq_lock, PSOCK, "kqclo1", 0); 2197 continue; 2198 } 2199 kn_enter_flux(kn); 2200 KQ_UNLOCK(kq); 2201 knote_drop(kn, td); 2202 KQ_LOCK(kq); 2203 } 2204 } 2205 if (kq->kq_knhashmask != 0) { 2206 for (i = 0; i <= kq->kq_knhashmask; i++) { 2207 while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) { 2208 if (kn_in_flux(kn)) { 2209 kq->kq_state |= KQ_FLUXWAIT; 2210 msleep(kq, &kq->kq_lock, PSOCK, 2211 "kqclo2", 0); 2212 continue; 2213 } 2214 kn_enter_flux(kn); 2215 KQ_UNLOCK(kq); 2216 knote_drop(kn, td); 2217 KQ_LOCK(kq); 2218 } 2219 } 2220 } 2221 2222 if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) { 2223 kq->kq_state |= KQ_TASKDRAIN; 2224 msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0); 2225 } 2226 2227 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2228 selwakeuppri(&kq->kq_sel, PSOCK); 2229 if (!SEL_WAITING(&kq->kq_sel)) 2230 kq->kq_state &= ~KQ_SEL; 2231 } 2232 2233 KQ_UNLOCK(kq); 2234 } 2235 2236 static void 2237 kqueue_destroy(struct kqueue *kq) 2238 { 2239 2240 KASSERT(kq->kq_fdp == NULL, 2241 ("kqueue still attached to a file descriptor")); 2242 seldrain(&kq->kq_sel); 2243 knlist_destroy(&kq->kq_sel.si_note); 2244 mtx_destroy(&kq->kq_lock); 2245 2246 if (kq->kq_knhash != NULL) 2247 free(kq->kq_knhash, M_KQUEUE); 2248 if (kq->kq_knlist != NULL) 2249 free(kq->kq_knlist, M_KQUEUE); 2250 2251 funsetown(&kq->kq_sigio); 2252 } 2253 2254 /*ARGSUSED*/ 2255 static int 2256 kqueue_close(struct file *fp, struct thread *td) 2257 { 2258 struct kqueue *kq = fp->f_data; 2259 struct filedesc *fdp; 2260 int error; 2261 int filedesc_unlock; 2262 2263 if ((error = kqueue_acquire(fp, &kq))) 2264 return error; 2265 kqueue_drain(kq, td); 2266 2267 /* 2268 * We could be called due to the knote_drop() doing fdrop(), 2269 * called from kqueue_register(). In this case the global 2270 * lock is owned, and filedesc sx is locked before, to not 2271 * take the sleepable lock after non-sleepable. 2272 */ 2273 fdp = kq->kq_fdp; 2274 kq->kq_fdp = NULL; 2275 if (!sx_xlocked(FILEDESC_LOCK(fdp))) { 2276 FILEDESC_XLOCK(fdp); 2277 filedesc_unlock = 1; 2278 } else 2279 filedesc_unlock = 0; 2280 TAILQ_REMOVE(&fdp->fd_kqlist, kq, kq_list); 2281 if (filedesc_unlock) 2282 FILEDESC_XUNLOCK(fdp); 2283 2284 kqueue_destroy(kq); 2285 chgkqcnt(kq->kq_cred->cr_ruidinfo, -1, 0); 2286 crfree(kq->kq_cred); 2287 free(kq, M_KQUEUE); 2288 fp->f_data = NULL; 2289 2290 return (0); 2291 } 2292 2293 static int 2294 kqueue_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 2295 { 2296 2297 kif->kf_type = KF_TYPE_KQUEUE; 2298 return (0); 2299 } 2300 2301 static void 2302 kqueue_wakeup(struct kqueue *kq) 2303 { 2304 KQ_OWNED(kq); 2305 2306 if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) { 2307 kq->kq_state &= ~KQ_SLEEP; 2308 wakeup(kq); 2309 } 2310 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2311 selwakeuppri(&kq->kq_sel, PSOCK); 2312 if (!SEL_WAITING(&kq->kq_sel)) 2313 kq->kq_state &= ~KQ_SEL; 2314 } 2315 if (!knlist_empty(&kq->kq_sel.si_note)) 2316 kqueue_schedtask(kq); 2317 if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) { 2318 pgsigio(&kq->kq_sigio, SIGIO, 0); 2319 } 2320 } 2321 2322 /* 2323 * Walk down a list of knotes, activating them if their event has triggered. 2324 * 2325 * There is a possibility to optimize in the case of one kq watching another. 2326 * Instead of scheduling a task to wake it up, you could pass enough state 2327 * down the chain to make up the parent kqueue. Make this code functional 2328 * first. 2329 */ 2330 void 2331 knote(struct knlist *list, long hint, int lockflags) 2332 { 2333 struct kqueue *kq; 2334 struct knote *kn, *tkn; 2335 int error; 2336 2337 if (list == NULL) 2338 return; 2339 2340 KNL_ASSERT_LOCK(list, lockflags & KNF_LISTLOCKED); 2341 2342 if ((lockflags & KNF_LISTLOCKED) == 0) 2343 list->kl_lock(list->kl_lockarg); 2344 2345 /* 2346 * If we unlock the list lock (and enter influx), we can 2347 * eliminate the kqueue scheduling, but this will introduce 2348 * four lock/unlock's for each knote to test. Also, marker 2349 * would be needed to keep iteration position, since filters 2350 * or other threads could remove events. 2351 */ 2352 SLIST_FOREACH_SAFE(kn, &list->kl_list, kn_selnext, tkn) { 2353 kq = kn->kn_kq; 2354 KQ_LOCK(kq); 2355 if (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0) { 2356 /* 2357 * Do not process the influx notes, except for 2358 * the influx coming from the kq unlock in the 2359 * kqueue_scan(). In the later case, we do 2360 * not interfere with the scan, since the code 2361 * fragment in kqueue_scan() locks the knlist, 2362 * and cannot proceed until we finished. 2363 */ 2364 KQ_UNLOCK(kq); 2365 } else if ((lockflags & KNF_NOKQLOCK) != 0) { 2366 kn_enter_flux(kn); 2367 KQ_UNLOCK(kq); 2368 error = kn->kn_fop->f_event(kn, hint); 2369 KQ_LOCK(kq); 2370 kn_leave_flux(kn); 2371 if (error) 2372 KNOTE_ACTIVATE(kn, 1); 2373 KQ_UNLOCK_FLUX(kq); 2374 } else { 2375 if (kn->kn_fop->f_event(kn, hint)) 2376 KNOTE_ACTIVATE(kn, 1); 2377 KQ_UNLOCK(kq); 2378 } 2379 } 2380 if ((lockflags & KNF_LISTLOCKED) == 0) 2381 list->kl_unlock(list->kl_lockarg); 2382 } 2383 2384 /* 2385 * add a knote to a knlist 2386 */ 2387 void 2388 knlist_add(struct knlist *knl, struct knote *kn, int islocked) 2389 { 2390 2391 KNL_ASSERT_LOCK(knl, islocked); 2392 KQ_NOTOWNED(kn->kn_kq); 2393 KASSERT(kn_in_flux(kn), ("knote %p not in flux", kn)); 2394 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2395 ("knote %p was not detached", kn)); 2396 if (!islocked) 2397 knl->kl_lock(knl->kl_lockarg); 2398 SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext); 2399 if (!islocked) 2400 knl->kl_unlock(knl->kl_lockarg); 2401 KQ_LOCK(kn->kn_kq); 2402 kn->kn_knlist = knl; 2403 kn->kn_status &= ~KN_DETACHED; 2404 KQ_UNLOCK(kn->kn_kq); 2405 } 2406 2407 static void 2408 knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked, 2409 int kqislocked) 2410 { 2411 2412 KASSERT(!kqislocked || knlislocked, ("kq locked w/o knl locked")); 2413 KNL_ASSERT_LOCK(knl, knlislocked); 2414 mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED); 2415 KASSERT(kqislocked || kn_in_flux(kn), ("knote %p not in flux", kn)); 2416 KASSERT((kn->kn_status & KN_DETACHED) == 0, 2417 ("knote %p was already detached", kn)); 2418 if (!knlislocked) 2419 knl->kl_lock(knl->kl_lockarg); 2420 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext); 2421 kn->kn_knlist = NULL; 2422 if (!knlislocked) 2423 kn_list_unlock(knl); 2424 if (!kqislocked) 2425 KQ_LOCK(kn->kn_kq); 2426 kn->kn_status |= KN_DETACHED; 2427 if (!kqislocked) 2428 KQ_UNLOCK(kn->kn_kq); 2429 } 2430 2431 /* 2432 * remove knote from the specified knlist 2433 */ 2434 void 2435 knlist_remove(struct knlist *knl, struct knote *kn, int islocked) 2436 { 2437 2438 knlist_remove_kq(knl, kn, islocked, 0); 2439 } 2440 2441 int 2442 knlist_empty(struct knlist *knl) 2443 { 2444 2445 KNL_ASSERT_LOCKED(knl); 2446 return (SLIST_EMPTY(&knl->kl_list)); 2447 } 2448 2449 static struct mtx knlist_lock; 2450 MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects", 2451 MTX_DEF); 2452 static void knlist_mtx_lock(void *arg); 2453 static void knlist_mtx_unlock(void *arg); 2454 2455 static void 2456 knlist_mtx_lock(void *arg) 2457 { 2458 2459 mtx_lock((struct mtx *)arg); 2460 } 2461 2462 static void 2463 knlist_mtx_unlock(void *arg) 2464 { 2465 2466 mtx_unlock((struct mtx *)arg); 2467 } 2468 2469 static void 2470 knlist_mtx_assert_lock(void *arg, int what) 2471 { 2472 2473 if (what == LA_LOCKED) 2474 mtx_assert((struct mtx *)arg, MA_OWNED); 2475 else 2476 mtx_assert((struct mtx *)arg, MA_NOTOWNED); 2477 } 2478 2479 static void 2480 knlist_rw_rlock(void *arg) 2481 { 2482 2483 rw_rlock((struct rwlock *)arg); 2484 } 2485 2486 static void 2487 knlist_rw_runlock(void *arg) 2488 { 2489 2490 rw_runlock((struct rwlock *)arg); 2491 } 2492 2493 static void 2494 knlist_rw_assert_lock(void *arg, int what) 2495 { 2496 2497 if (what == LA_LOCKED) 2498 rw_assert((struct rwlock *)arg, RA_LOCKED); 2499 else 2500 rw_assert((struct rwlock *)arg, RA_UNLOCKED); 2501 } 2502 2503 void 2504 knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *), 2505 void (*kl_unlock)(void *), 2506 void (*kl_assert_lock)(void *, int)) 2507 { 2508 2509 if (lock == NULL) 2510 knl->kl_lockarg = &knlist_lock; 2511 else 2512 knl->kl_lockarg = lock; 2513 2514 if (kl_lock == NULL) 2515 knl->kl_lock = knlist_mtx_lock; 2516 else 2517 knl->kl_lock = kl_lock; 2518 if (kl_unlock == NULL) 2519 knl->kl_unlock = knlist_mtx_unlock; 2520 else 2521 knl->kl_unlock = kl_unlock; 2522 if (kl_assert_lock == NULL) 2523 knl->kl_assert_lock = knlist_mtx_assert_lock; 2524 else 2525 knl->kl_assert_lock = kl_assert_lock; 2526 2527 knl->kl_autodestroy = 0; 2528 SLIST_INIT(&knl->kl_list); 2529 } 2530 2531 void 2532 knlist_init_mtx(struct knlist *knl, struct mtx *lock) 2533 { 2534 2535 knlist_init(knl, lock, NULL, NULL, NULL); 2536 } 2537 2538 struct knlist * 2539 knlist_alloc(struct mtx *lock) 2540 { 2541 struct knlist *knl; 2542 2543 knl = malloc(sizeof(struct knlist), M_KQUEUE, M_WAITOK); 2544 knlist_init_mtx(knl, lock); 2545 return (knl); 2546 } 2547 2548 void 2549 knlist_init_rw_reader(struct knlist *knl, struct rwlock *lock) 2550 { 2551 2552 knlist_init(knl, lock, knlist_rw_rlock, knlist_rw_runlock, 2553 knlist_rw_assert_lock); 2554 } 2555 2556 void 2557 knlist_destroy(struct knlist *knl) 2558 { 2559 2560 KASSERT(KNLIST_EMPTY(knl), 2561 ("destroying knlist %p with knotes on it", knl)); 2562 } 2563 2564 void 2565 knlist_detach(struct knlist *knl) 2566 { 2567 2568 KNL_ASSERT_LOCKED(knl); 2569 knl->kl_autodestroy = 1; 2570 if (knlist_empty(knl)) { 2571 knlist_destroy(knl); 2572 free(knl, M_KQUEUE); 2573 } 2574 } 2575 2576 /* 2577 * Even if we are locked, we may need to drop the lock to allow any influx 2578 * knotes time to "settle". 2579 */ 2580 void 2581 knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn) 2582 { 2583 struct knote *kn, *kn2; 2584 struct kqueue *kq; 2585 2586 KASSERT(!knl->kl_autodestroy, ("cleardel for autodestroy %p", knl)); 2587 if (islocked) 2588 KNL_ASSERT_LOCKED(knl); 2589 else { 2590 KNL_ASSERT_UNLOCKED(knl); 2591 again: /* need to reacquire lock since we have dropped it */ 2592 knl->kl_lock(knl->kl_lockarg); 2593 } 2594 2595 SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) { 2596 kq = kn->kn_kq; 2597 KQ_LOCK(kq); 2598 if (kn_in_flux(kn)) { 2599 KQ_UNLOCK(kq); 2600 continue; 2601 } 2602 knlist_remove_kq(knl, kn, 1, 1); 2603 if (killkn) { 2604 kn_enter_flux(kn); 2605 KQ_UNLOCK(kq); 2606 knote_drop_detached(kn, td); 2607 } else { 2608 /* Make sure cleared knotes disappear soon */ 2609 kn->kn_flags |= EV_EOF | EV_ONESHOT; 2610 KQ_UNLOCK(kq); 2611 } 2612 kq = NULL; 2613 } 2614 2615 if (!SLIST_EMPTY(&knl->kl_list)) { 2616 /* there are still in flux knotes remaining */ 2617 kn = SLIST_FIRST(&knl->kl_list); 2618 kq = kn->kn_kq; 2619 KQ_LOCK(kq); 2620 KASSERT(kn_in_flux(kn), ("knote removed w/o list lock")); 2621 knl->kl_unlock(knl->kl_lockarg); 2622 kq->kq_state |= KQ_FLUXWAIT; 2623 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0); 2624 kq = NULL; 2625 goto again; 2626 } 2627 2628 if (islocked) 2629 KNL_ASSERT_LOCKED(knl); 2630 else { 2631 knl->kl_unlock(knl->kl_lockarg); 2632 KNL_ASSERT_UNLOCKED(knl); 2633 } 2634 } 2635 2636 /* 2637 * Remove all knotes referencing a specified fd must be called with FILEDESC 2638 * lock. This prevents a race where a new fd comes along and occupies the 2639 * entry and we attach a knote to the fd. 2640 */ 2641 void 2642 knote_fdclose(struct thread *td, int fd) 2643 { 2644 struct filedesc *fdp = td->td_proc->p_fd; 2645 struct kqueue *kq; 2646 struct knote *kn; 2647 int influx; 2648 2649 FILEDESC_XLOCK_ASSERT(fdp); 2650 2651 /* 2652 * We shouldn't have to worry about new kevents appearing on fd 2653 * since filedesc is locked. 2654 */ 2655 TAILQ_FOREACH(kq, &fdp->fd_kqlist, kq_list) { 2656 KQ_LOCK(kq); 2657 2658 again: 2659 influx = 0; 2660 while (kq->kq_knlistsize > fd && 2661 (kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) { 2662 if (kn_in_flux(kn)) { 2663 /* someone else might be waiting on our knote */ 2664 if (influx) 2665 wakeup(kq); 2666 kq->kq_state |= KQ_FLUXWAIT; 2667 msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0); 2668 goto again; 2669 } 2670 kn_enter_flux(kn); 2671 KQ_UNLOCK(kq); 2672 influx = 1; 2673 knote_drop(kn, td); 2674 KQ_LOCK(kq); 2675 } 2676 KQ_UNLOCK_FLUX(kq); 2677 } 2678 } 2679 2680 static int 2681 knote_attach(struct knote *kn, struct kqueue *kq) 2682 { 2683 struct klist *list; 2684 2685 KASSERT(kn_in_flux(kn), ("knote %p not marked influx", kn)); 2686 KQ_OWNED(kq); 2687 2688 if ((kq->kq_state & KQ_CLOSING) != 0) 2689 return (EBADF); 2690 if (kn->kn_fop->f_isfd) { 2691 if (kn->kn_id >= kq->kq_knlistsize) 2692 return (ENOMEM); 2693 list = &kq->kq_knlist[kn->kn_id]; 2694 } else { 2695 if (kq->kq_knhash == NULL) 2696 return (ENOMEM); 2697 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2698 } 2699 SLIST_INSERT_HEAD(list, kn, kn_link); 2700 return (0); 2701 } 2702 2703 static void 2704 knote_drop(struct knote *kn, struct thread *td) 2705 { 2706 2707 if ((kn->kn_status & KN_DETACHED) == 0) 2708 kn->kn_fop->f_detach(kn); 2709 knote_drop_detached(kn, td); 2710 } 2711 2712 static void 2713 knote_drop_detached(struct knote *kn, struct thread *td) 2714 { 2715 struct kqueue *kq; 2716 struct klist *list; 2717 2718 kq = kn->kn_kq; 2719 2720 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2721 ("knote %p still attached", kn)); 2722 KQ_NOTOWNED(kq); 2723 2724 KQ_LOCK(kq); 2725 KASSERT(kn->kn_influx == 1, 2726 ("knote_drop called on %p with influx %d", kn, kn->kn_influx)); 2727 2728 if (kn->kn_fop->f_isfd) 2729 list = &kq->kq_knlist[kn->kn_id]; 2730 else 2731 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2732 2733 if (!SLIST_EMPTY(list)) 2734 SLIST_REMOVE(list, kn, knote, kn_link); 2735 if (kn->kn_status & KN_QUEUED) 2736 knote_dequeue(kn); 2737 KQ_UNLOCK_FLUX(kq); 2738 2739 if (kn->kn_fop->f_isfd) { 2740 fdrop(kn->kn_fp, td); 2741 kn->kn_fp = NULL; 2742 } 2743 kqueue_fo_release(kn->kn_kevent.filter); 2744 kn->kn_fop = NULL; 2745 knote_free(kn); 2746 } 2747 2748 static void 2749 knote_enqueue(struct knote *kn) 2750 { 2751 struct kqueue *kq = kn->kn_kq; 2752 2753 KQ_OWNED(kn->kn_kq); 2754 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 2755 2756 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2757 kn->kn_status |= KN_QUEUED; 2758 kq->kq_count++; 2759 kqueue_wakeup(kq); 2760 } 2761 2762 static void 2763 knote_dequeue(struct knote *kn) 2764 { 2765 struct kqueue *kq = kn->kn_kq; 2766 2767 KQ_OWNED(kn->kn_kq); 2768 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 2769 2770 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 2771 kn->kn_status &= ~KN_QUEUED; 2772 kq->kq_count--; 2773 } 2774 2775 static void 2776 knote_init(void) 2777 { 2778 2779 knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL, 2780 NULL, NULL, UMA_ALIGN_PTR, 0); 2781 } 2782 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL); 2783 2784 static struct knote * 2785 knote_alloc(int mflag) 2786 { 2787 2788 return (uma_zalloc(knote_zone, mflag | M_ZERO)); 2789 } 2790 2791 static void 2792 knote_free(struct knote *kn) 2793 { 2794 2795 uma_zfree(knote_zone, kn); 2796 } 2797 2798 /* 2799 * Register the kev w/ the kq specified by fd. 2800 */ 2801 int 2802 kqfd_register(int fd, struct kevent *kev, struct thread *td, int mflag) 2803 { 2804 struct kqueue *kq; 2805 struct file *fp; 2806 cap_rights_t rights; 2807 int error; 2808 2809 error = fget(td, fd, cap_rights_init_one(&rights, CAP_KQUEUE_CHANGE), 2810 &fp); 2811 if (error != 0) 2812 return (error); 2813 if ((error = kqueue_acquire(fp, &kq)) != 0) 2814 goto noacquire; 2815 2816 error = kqueue_register(kq, kev, td, mflag); 2817 kqueue_release(kq, 0); 2818 2819 noacquire: 2820 fdrop(fp, td); 2821 return (error); 2822 } 2823