Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_event.c
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1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org> 5 * Copyright 2004 John-Mark Gurney <jmg@FreeBSD.org> 6 * Copyright (c) 2009 Apple, Inc. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 34 #include "opt_ktrace.h" 35 #include "opt_kqueue.h" 36 37 #ifdef COMPAT_FREEBSD11 38 #define _WANT_FREEBSD11_KEVENT 39 #endif 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/capsicum.h> 44 #include <sys/kernel.h> 45 #include <sys/limits.h> 46 #include <sys/lock.h> 47 #include <sys/mutex.h> 48 #include <sys/rwlock.h> 49 #include <sys/proc.h> 50 #include <sys/malloc.h> 51 #include <sys/unistd.h> 52 #include <sys/file.h> 53 #include <sys/filedesc.h> 54 #include <sys/filio.h> 55 #include <sys/fcntl.h> 56 #include <sys/kthread.h> 57 #include <sys/selinfo.h> 58 #include <sys/queue.h> 59 #include <sys/event.h> 60 #include <sys/eventvar.h> 61 #include <sys/poll.h> 62 #include <sys/protosw.h> 63 #include <sys/resourcevar.h> 64 #include <sys/sigio.h> 65 #include <sys/signalvar.h> 66 #include <sys/socket.h> 67 #include <sys/socketvar.h> 68 #include <sys/stat.h> 69 #include <sys/sysctl.h> 70 #include <sys/sysproto.h> 71 #include <sys/syscallsubr.h> 72 #include <sys/taskqueue.h> 73 #include <sys/uio.h> 74 #include <sys/user.h> 75 #ifdef KTRACE 76 #include <sys/ktrace.h> 77 #endif 78 #include <machine/atomic.h> 79 80 #include <vm/uma.h> 81 82 static MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system"); 83 84 /* 85 * This lock is used if multiple kq locks are required. This possibly 86 * should be made into a per proc lock. 87 */ 88 static struct mtx kq_global; 89 MTX_SYSINIT(kq_global, &kq_global, "kqueue order", MTX_DEF); 90 #define KQ_GLOBAL_LOCK(lck, haslck) do { \ 91 if (!haslck) \ 92 mtx_lock(lck); \ 93 haslck = 1; \ 94 } while (0) 95 #define KQ_GLOBAL_UNLOCK(lck, haslck) do { \ 96 if (haslck) \ 97 mtx_unlock(lck); \ 98 haslck = 0; \ 99 } while (0) 100 101 TASKQUEUE_DEFINE_THREAD(kqueue_ctx); 102 103 static int kevent_copyout(void *arg, struct kevent *kevp, int count); 104 static int kevent_copyin(void *arg, struct kevent *kevp, int count); 105 static int kqueue_register(struct kqueue *kq, struct kevent *kev, 106 struct thread *td, int mflag); 107 static int kqueue_acquire(struct file *fp, struct kqueue **kqp); 108 static void kqueue_release(struct kqueue *kq, int locked); 109 static void kqueue_destroy(struct kqueue *kq); 110 static void kqueue_drain(struct kqueue *kq, struct thread *td); 111 static int kqueue_expand(struct kqueue *kq, struct filterops *fops, 112 uintptr_t ident, int mflag); 113 static void kqueue_task(void *arg, int pending); 114 static int kqueue_scan(struct kqueue *kq, int maxevents, 115 struct kevent_copyops *k_ops, 116 const struct timespec *timeout, 117 struct kevent *keva, struct thread *td); 118 static void kqueue_wakeup(struct kqueue *kq); 119 static struct filterops *kqueue_fo_find(int filt); 120 static void kqueue_fo_release(int filt); 121 struct g_kevent_args; 122 static int kern_kevent_generic(struct thread *td, 123 struct g_kevent_args *uap, 124 struct kevent_copyops *k_ops, const char *struct_name); 125 126 static fo_ioctl_t kqueue_ioctl; 127 static fo_poll_t kqueue_poll; 128 static fo_kqfilter_t kqueue_kqfilter; 129 static fo_stat_t kqueue_stat; 130 static fo_close_t kqueue_close; 131 static fo_fill_kinfo_t kqueue_fill_kinfo; 132 133 static struct fileops kqueueops = { 134 .fo_read = invfo_rdwr, 135 .fo_write = invfo_rdwr, 136 .fo_truncate = invfo_truncate, 137 .fo_ioctl = kqueue_ioctl, 138 .fo_poll = kqueue_poll, 139 .fo_kqfilter = kqueue_kqfilter, 140 .fo_stat = kqueue_stat, 141 .fo_close = kqueue_close, 142 .fo_chmod = invfo_chmod, 143 .fo_chown = invfo_chown, 144 .fo_sendfile = invfo_sendfile, 145 .fo_fill_kinfo = kqueue_fill_kinfo, 146 }; 147 148 static int knote_attach(struct knote *kn, struct kqueue *kq); 149 static void knote_drop(struct knote *kn, struct thread *td); 150 static void knote_drop_detached(struct knote *kn, struct thread *td); 151 static void knote_enqueue(struct knote *kn); 152 static void knote_dequeue(struct knote *kn); 153 static void knote_init(void); 154 static struct knote *knote_alloc(int mflag); 155 static void knote_free(struct knote *kn); 156 157 static void filt_kqdetach(struct knote *kn); 158 static int filt_kqueue(struct knote *kn, long hint); 159 static int filt_procattach(struct knote *kn); 160 static void filt_procdetach(struct knote *kn); 161 static int filt_proc(struct knote *kn, long hint); 162 static int filt_fileattach(struct knote *kn); 163 static void filt_timerexpire(void *knx); 164 static void filt_timerexpire_l(struct knote *kn, bool proc_locked); 165 static int filt_timerattach(struct knote *kn); 166 static void filt_timerdetach(struct knote *kn); 167 static void filt_timerstart(struct knote *kn, sbintime_t to); 168 static void filt_timertouch(struct knote *kn, struct kevent *kev, 169 u_long type); 170 static int filt_timervalidate(struct knote *kn, sbintime_t *to); 171 static int filt_timer(struct knote *kn, long hint); 172 static int filt_userattach(struct knote *kn); 173 static void filt_userdetach(struct knote *kn); 174 static int filt_user(struct knote *kn, long hint); 175 static void filt_usertouch(struct knote *kn, struct kevent *kev, 176 u_long type); 177 178 static struct filterops file_filtops = { 179 .f_isfd = 1, 180 .f_attach = filt_fileattach, 181 }; 182 static struct filterops kqread_filtops = { 183 .f_isfd = 1, 184 .f_detach = filt_kqdetach, 185 .f_event = filt_kqueue, 186 }; 187 /* XXX - move to kern_proc.c? */ 188 static struct filterops proc_filtops = { 189 .f_isfd = 0, 190 .f_attach = filt_procattach, 191 .f_detach = filt_procdetach, 192 .f_event = filt_proc, 193 }; 194 static struct filterops timer_filtops = { 195 .f_isfd = 0, 196 .f_attach = filt_timerattach, 197 .f_detach = filt_timerdetach, 198 .f_event = filt_timer, 199 .f_touch = filt_timertouch, 200 }; 201 static struct filterops user_filtops = { 202 .f_attach = filt_userattach, 203 .f_detach = filt_userdetach, 204 .f_event = filt_user, 205 .f_touch = filt_usertouch, 206 }; 207 208 static uma_zone_t knote_zone; 209 static unsigned int __exclusive_cache_line kq_ncallouts; 210 static unsigned int kq_calloutmax = 4 * 1024; 211 SYSCTL_UINT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW, 212 &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue"); 213 214 /* XXX - ensure not influx ? */ 215 #define KNOTE_ACTIVATE(kn, islock) do { \ 216 if ((islock)) \ 217 mtx_assert(&(kn)->kn_kq->kq_lock, MA_OWNED); \ 218 else \ 219 KQ_LOCK((kn)->kn_kq); \ 220 (kn)->kn_status |= KN_ACTIVE; \ 221 if (((kn)->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 222 knote_enqueue((kn)); \ 223 if (!(islock)) \ 224 KQ_UNLOCK((kn)->kn_kq); \ 225 } while(0) 226 #define KQ_LOCK(kq) do { \ 227 mtx_lock(&(kq)->kq_lock); \ 228 } while (0) 229 #define KQ_FLUX_WAKEUP(kq) do { \ 230 if (((kq)->kq_state & KQ_FLUXWAIT) == KQ_FLUXWAIT) { \ 231 (kq)->kq_state &= ~KQ_FLUXWAIT; \ 232 wakeup((kq)); \ 233 } \ 234 } while (0) 235 #define KQ_UNLOCK_FLUX(kq) do { \ 236 KQ_FLUX_WAKEUP(kq); \ 237 mtx_unlock(&(kq)->kq_lock); \ 238 } while (0) 239 #define KQ_UNLOCK(kq) do { \ 240 mtx_unlock(&(kq)->kq_lock); \ 241 } while (0) 242 #define KQ_OWNED(kq) do { \ 243 mtx_assert(&(kq)->kq_lock, MA_OWNED); \ 244 } while (0) 245 #define KQ_NOTOWNED(kq) do { \ 246 mtx_assert(&(kq)->kq_lock, MA_NOTOWNED); \ 247 } while (0) 248 249 static struct knlist * 250 kn_list_lock(struct knote *kn) 251 { 252 struct knlist *knl; 253 254 knl = kn->kn_knlist; 255 if (knl != NULL) 256 knl->kl_lock(knl->kl_lockarg); 257 return (knl); 258 } 259 260 static void 261 kn_list_unlock(struct knlist *knl) 262 { 263 bool do_free; 264 265 if (knl == NULL) 266 return; 267 do_free = knl->kl_autodestroy && knlist_empty(knl); 268 knl->kl_unlock(knl->kl_lockarg); 269 if (do_free) { 270 knlist_destroy(knl); 271 free(knl, M_KQUEUE); 272 } 273 } 274 275 static bool 276 kn_in_flux(struct knote *kn) 277 { 278 279 return (kn->kn_influx > 0); 280 } 281 282 static void 283 kn_enter_flux(struct knote *kn) 284 { 285 286 KQ_OWNED(kn->kn_kq); 287 MPASS(kn->kn_influx < INT_MAX); 288 kn->kn_influx++; 289 } 290 291 static bool 292 kn_leave_flux(struct knote *kn) 293 { 294 295 KQ_OWNED(kn->kn_kq); 296 MPASS(kn->kn_influx > 0); 297 kn->kn_influx--; 298 return (kn->kn_influx == 0); 299 } 300 301 #define KNL_ASSERT_LOCK(knl, islocked) do { \ 302 if (islocked) \ 303 KNL_ASSERT_LOCKED(knl); \ 304 else \ 305 KNL_ASSERT_UNLOCKED(knl); \ 306 } while (0) 307 #ifdef INVARIANTS 308 #define KNL_ASSERT_LOCKED(knl) do { \ 309 knl->kl_assert_lock((knl)->kl_lockarg, LA_LOCKED); \ 310 } while (0) 311 #define KNL_ASSERT_UNLOCKED(knl) do { \ 312 knl->kl_assert_lock((knl)->kl_lockarg, LA_UNLOCKED); \ 313 } while (0) 314 #else /* !INVARIANTS */ 315 #define KNL_ASSERT_LOCKED(knl) do {} while(0) 316 #define KNL_ASSERT_UNLOCKED(knl) do {} while (0) 317 #endif /* INVARIANTS */ 318 319 #ifndef KN_HASHSIZE 320 #define KN_HASHSIZE 64 /* XXX should be tunable */ 321 #endif 322 323 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 324 325 static int 326 filt_nullattach(struct knote *kn) 327 { 328 329 return (ENXIO); 330 }; 331 332 struct filterops null_filtops = { 333 .f_isfd = 0, 334 .f_attach = filt_nullattach, 335 }; 336 337 /* XXX - make SYSINIT to add these, and move into respective modules. */ 338 extern struct filterops sig_filtops; 339 extern struct filterops fs_filtops; 340 341 /* 342 * Table for for all system-defined filters. 343 */ 344 static struct mtx filterops_lock; 345 MTX_SYSINIT(kqueue_filterops, &filterops_lock, "protect sysfilt_ops", 346 MTX_DEF); 347 static struct { 348 struct filterops *for_fop; 349 int for_nolock; 350 int for_refcnt; 351 } sysfilt_ops[EVFILT_SYSCOUNT] = { 352 { &file_filtops, 1 }, /* EVFILT_READ */ 353 { &file_filtops, 1 }, /* EVFILT_WRITE */ 354 { &null_filtops }, /* EVFILT_AIO */ 355 { &file_filtops, 1 }, /* EVFILT_VNODE */ 356 { &proc_filtops, 1 }, /* EVFILT_PROC */ 357 { &sig_filtops, 1 }, /* EVFILT_SIGNAL */ 358 { &timer_filtops, 1 }, /* EVFILT_TIMER */ 359 { &file_filtops, 1 }, /* EVFILT_PROCDESC */ 360 { &fs_filtops, 1 }, /* EVFILT_FS */ 361 { &null_filtops }, /* EVFILT_LIO */ 362 { &user_filtops, 1 }, /* EVFILT_USER */ 363 { &null_filtops }, /* EVFILT_SENDFILE */ 364 { &file_filtops, 1 }, /* EVFILT_EMPTY */ 365 }; 366 367 /* 368 * Simple redirection for all cdevsw style objects to call their fo_kqfilter 369 * method. 370 */ 371 static int 372 filt_fileattach(struct knote *kn) 373 { 374 375 return (fo_kqfilter(kn->kn_fp, kn)); 376 } 377 378 /*ARGSUSED*/ 379 static int 380 kqueue_kqfilter(struct file *fp, struct knote *kn) 381 { 382 struct kqueue *kq = kn->kn_fp->f_data; 383 384 if (kn->kn_filter != EVFILT_READ) 385 return (EINVAL); 386 387 kn->kn_status |= KN_KQUEUE; 388 kn->kn_fop = &kqread_filtops; 389 knlist_add(&kq->kq_sel.si_note, kn, 0); 390 391 return (0); 392 } 393 394 static void 395 filt_kqdetach(struct knote *kn) 396 { 397 struct kqueue *kq = kn->kn_fp->f_data; 398 399 knlist_remove(&kq->kq_sel.si_note, kn, 0); 400 } 401 402 /*ARGSUSED*/ 403 static int 404 filt_kqueue(struct knote *kn, long hint) 405 { 406 struct kqueue *kq = kn->kn_fp->f_data; 407 408 kn->kn_data = kq->kq_count; 409 return (kn->kn_data > 0); 410 } 411 412 /* XXX - move to kern_proc.c? */ 413 static int 414 filt_procattach(struct knote *kn) 415 { 416 struct proc *p; 417 int error; 418 bool exiting, immediate; 419 420 exiting = immediate = false; 421 if (kn->kn_sfflags & NOTE_EXIT) 422 p = pfind_any(kn->kn_id); 423 else 424 p = pfind(kn->kn_id); 425 if (p == NULL) 426 return (ESRCH); 427 if (p->p_flag & P_WEXIT) 428 exiting = true; 429 430 if ((error = p_cansee(curthread, p))) { 431 PROC_UNLOCK(p); 432 return (error); 433 } 434 435 kn->kn_ptr.p_proc = p; 436 kn->kn_flags |= EV_CLEAR; /* automatically set */ 437 438 /* 439 * Internal flag indicating registration done by kernel for the 440 * purposes of getting a NOTE_CHILD notification. 441 */ 442 if (kn->kn_flags & EV_FLAG2) { 443 kn->kn_flags &= ~EV_FLAG2; 444 kn->kn_data = kn->kn_sdata; /* ppid */ 445 kn->kn_fflags = NOTE_CHILD; 446 kn->kn_sfflags &= ~(NOTE_EXIT | NOTE_EXEC | NOTE_FORK); 447 immediate = true; /* Force immediate activation of child note. */ 448 } 449 /* 450 * Internal flag indicating registration done by kernel (for other than 451 * NOTE_CHILD). 452 */ 453 if (kn->kn_flags & EV_FLAG1) { 454 kn->kn_flags &= ~EV_FLAG1; 455 } 456 457 knlist_add(p->p_klist, kn, 1); 458 459 /* 460 * Immediately activate any child notes or, in the case of a zombie 461 * target process, exit notes. The latter is necessary to handle the 462 * case where the target process, e.g. a child, dies before the kevent 463 * is registered. 464 */ 465 if (immediate || (exiting && filt_proc(kn, NOTE_EXIT))) 466 KNOTE_ACTIVATE(kn, 0); 467 468 PROC_UNLOCK(p); 469 470 return (0); 471 } 472 473 /* 474 * The knote may be attached to a different process, which may exit, 475 * leaving nothing for the knote to be attached to. So when the process 476 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 477 * it will be deleted when read out. However, as part of the knote deletion, 478 * this routine is called, so a check is needed to avoid actually performing 479 * a detach, because the original process does not exist any more. 480 */ 481 /* XXX - move to kern_proc.c? */ 482 static void 483 filt_procdetach(struct knote *kn) 484 { 485 486 knlist_remove(kn->kn_knlist, kn, 0); 487 kn->kn_ptr.p_proc = NULL; 488 } 489 490 /* XXX - move to kern_proc.c? */ 491 static int 492 filt_proc(struct knote *kn, long hint) 493 { 494 struct proc *p; 495 u_int event; 496 497 p = kn->kn_ptr.p_proc; 498 if (p == NULL) /* already activated, from attach filter */ 499 return (0); 500 501 /* Mask off extra data. */ 502 event = (u_int)hint & NOTE_PCTRLMASK; 503 504 /* If the user is interested in this event, record it. */ 505 if (kn->kn_sfflags & event) 506 kn->kn_fflags |= event; 507 508 /* Process is gone, so flag the event as finished. */ 509 if (event == NOTE_EXIT) { 510 kn->kn_flags |= EV_EOF | EV_ONESHOT; 511 kn->kn_ptr.p_proc = NULL; 512 if (kn->kn_fflags & NOTE_EXIT) 513 kn->kn_data = KW_EXITCODE(p->p_xexit, p->p_xsig); 514 if (kn->kn_fflags == 0) 515 kn->kn_flags |= EV_DROP; 516 return (1); 517 } 518 519 return (kn->kn_fflags != 0); 520 } 521 522 /* 523 * Called when the process forked. It mostly does the same as the 524 * knote(), activating all knotes registered to be activated when the 525 * process forked. Additionally, for each knote attached to the 526 * parent, check whether user wants to track the new process. If so 527 * attach a new knote to it, and immediately report an event with the 528 * child's pid. 529 */ 530 void 531 knote_fork(struct knlist *list, int pid) 532 { 533 struct kqueue *kq; 534 struct knote *kn; 535 struct kevent kev; 536 int error; 537 538 MPASS(list != NULL); 539 KNL_ASSERT_LOCKED(list); 540 if (SLIST_EMPTY(&list->kl_list)) 541 return; 542 543 memset(&kev, 0, sizeof(kev)); 544 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { 545 kq = kn->kn_kq; 546 KQ_LOCK(kq); 547 if (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0) { 548 KQ_UNLOCK(kq); 549 continue; 550 } 551 552 /* 553 * The same as knote(), activate the event. 554 */ 555 if ((kn->kn_sfflags & NOTE_TRACK) == 0) { 556 if (kn->kn_fop->f_event(kn, NOTE_FORK)) 557 KNOTE_ACTIVATE(kn, 1); 558 KQ_UNLOCK(kq); 559 continue; 560 } 561 562 /* 563 * The NOTE_TRACK case. In addition to the activation 564 * of the event, we need to register new events to 565 * track the child. Drop the locks in preparation for 566 * the call to kqueue_register(). 567 */ 568 kn_enter_flux(kn); 569 KQ_UNLOCK(kq); 570 list->kl_unlock(list->kl_lockarg); 571 572 /* 573 * Activate existing knote and register tracking knotes with 574 * new process. 575 * 576 * First register a knote to get just the child notice. This 577 * must be a separate note from a potential NOTE_EXIT 578 * notification since both NOTE_CHILD and NOTE_EXIT are defined 579 * to use the data field (in conflicting ways). 580 */ 581 kev.ident = pid; 582 kev.filter = kn->kn_filter; 583 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_ONESHOT | 584 EV_FLAG2; 585 kev.fflags = kn->kn_sfflags; 586 kev.data = kn->kn_id; /* parent */ 587 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 588 error = kqueue_register(kq, &kev, NULL, M_NOWAIT); 589 if (error) 590 kn->kn_fflags |= NOTE_TRACKERR; 591 592 /* 593 * Then register another knote to track other potential events 594 * from the new process. 595 */ 596 kev.ident = pid; 597 kev.filter = kn->kn_filter; 598 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 599 kev.fflags = kn->kn_sfflags; 600 kev.data = kn->kn_id; /* parent */ 601 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 602 error = kqueue_register(kq, &kev, NULL, M_NOWAIT); 603 if (error) 604 kn->kn_fflags |= NOTE_TRACKERR; 605 if (kn->kn_fop->f_event(kn, NOTE_FORK)) 606 KNOTE_ACTIVATE(kn, 0); 607 list->kl_lock(list->kl_lockarg); 608 KQ_LOCK(kq); 609 kn_leave_flux(kn); 610 KQ_UNLOCK_FLUX(kq); 611 } 612 } 613 614 /* 615 * XXX: EVFILT_TIMER should perhaps live in kern_time.c beside the 616 * interval timer support code. 617 */ 618 619 #define NOTE_TIMER_PRECMASK \ 620 (NOTE_SECONDS | NOTE_MSECONDS | NOTE_USECONDS | NOTE_NSECONDS) 621 622 static sbintime_t 623 timer2sbintime(int64_t data, int flags) 624 { 625 int64_t secs; 626 627 /* 628 * Macros for converting to the fractional second portion of an 629 * sbintime_t using 64bit multiplication to improve precision. 630 */ 631 #define NS_TO_SBT(ns) (((ns) * (((uint64_t)1 << 63) / 500000000)) >> 32) 632 #define US_TO_SBT(us) (((us) * (((uint64_t)1 << 63) / 500000)) >> 32) 633 #define MS_TO_SBT(ms) (((ms) * (((uint64_t)1 << 63) / 500)) >> 32) 634 switch (flags & NOTE_TIMER_PRECMASK) { 635 case NOTE_SECONDS: 636 #ifdef __LP64__ 637 if (data > (SBT_MAX / SBT_1S)) 638 return (SBT_MAX); 639 #endif 640 return ((sbintime_t)data << 32); 641 case NOTE_MSECONDS: /* FALLTHROUGH */ 642 case 0: 643 if (data >= 1000) { 644 secs = data / 1000; 645 #ifdef __LP64__ 646 if (secs > (SBT_MAX / SBT_1S)) 647 return (SBT_MAX); 648 #endif 649 return (secs << 32 | MS_TO_SBT(data % 1000)); 650 } 651 return (MS_TO_SBT(data)); 652 case NOTE_USECONDS: 653 if (data >= 1000000) { 654 secs = data / 1000000; 655 #ifdef __LP64__ 656 if (secs > (SBT_MAX / SBT_1S)) 657 return (SBT_MAX); 658 #endif 659 return (secs << 32 | US_TO_SBT(data % 1000000)); 660 } 661 return (US_TO_SBT(data)); 662 case NOTE_NSECONDS: 663 if (data >= 1000000000) { 664 secs = data / 1000000000; 665 #ifdef __LP64__ 666 if (secs > (SBT_MAX / SBT_1S)) 667 return (SBT_MAX); 668 #endif 669 return (secs << 32 | NS_TO_SBT(data % 1000000000)); 670 } 671 return (NS_TO_SBT(data)); 672 default: 673 break; 674 } 675 return (-1); 676 } 677 678 struct kq_timer_cb_data { 679 struct callout c; 680 struct proc *p; 681 struct knote *kn; 682 int cpuid; 683 int flags; 684 TAILQ_ENTRY(kq_timer_cb_data) link; 685 sbintime_t next; /* next timer event fires at */ 686 sbintime_t to; /* precalculated timer period, 0 for abs */ 687 }; 688 689 #define KQ_TIMER_CB_ENQUEUED 0x01 690 691 static void 692 kqtimer_sched_callout(struct kq_timer_cb_data *kc) 693 { 694 callout_reset_sbt_on(&kc->c, kc->next, 0, filt_timerexpire, kc->kn, 695 kc->cpuid, C_ABSOLUTE); 696 } 697 698 void 699 kqtimer_proc_continue(struct proc *p) 700 { 701 struct kq_timer_cb_data *kc, *kc1; 702 struct bintime bt; 703 sbintime_t now; 704 705 PROC_LOCK_ASSERT(p, MA_OWNED); 706 707 getboottimebin(&bt); 708 now = bttosbt(bt); 709 710 TAILQ_FOREACH_SAFE(kc, &p->p_kqtim_stop, link, kc1) { 711 TAILQ_REMOVE(&p->p_kqtim_stop, kc, link); 712 kc->flags &= ~KQ_TIMER_CB_ENQUEUED; 713 if (kc->next <= now) 714 filt_timerexpire_l(kc->kn, true); 715 else 716 kqtimer_sched_callout(kc); 717 } 718 } 719 720 static void 721 filt_timerexpire_l(struct knote *kn, bool proc_locked) 722 { 723 struct kq_timer_cb_data *kc; 724 struct proc *p; 725 uint64_t delta; 726 sbintime_t now; 727 728 kc = kn->kn_ptr.p_v; 729 730 if ((kn->kn_flags & EV_ONESHOT) != 0 || kc->to == 0) { 731 kn->kn_data++; 732 KNOTE_ACTIVATE(kn, 0); 733 return; 734 } 735 736 now = sbinuptime(); 737 if (now >= kc->next) { 738 delta = (now - kc->next) / kc->to; 739 if (delta == 0) 740 delta = 1; 741 kn->kn_data += delta; 742 kc->next += (delta + 1) * kc->to; 743 if (now >= kc->next) /* overflow */ 744 kc->next = now + kc->to; 745 KNOTE_ACTIVATE(kn, 0); /* XXX - handle locking */ 746 } 747 748 /* 749 * Initial check for stopped kc->p is racy. It is fine to 750 * miss the set of the stop flags, at worst we would schedule 751 * one more callout. On the other hand, it is not fine to not 752 * schedule when we we missed clearing of the flags, we 753 * recheck them under the lock and observe consistent state. 754 */ 755 p = kc->p; 756 if (P_SHOULDSTOP(p) || P_KILLED(p)) { 757 if (!proc_locked) 758 PROC_LOCK(p); 759 if (P_SHOULDSTOP(p) || P_KILLED(p)) { 760 if ((kc->flags & KQ_TIMER_CB_ENQUEUED) == 0) { 761 kc->flags |= KQ_TIMER_CB_ENQUEUED; 762 TAILQ_INSERT_TAIL(&p->p_kqtim_stop, kc, link); 763 } 764 if (!proc_locked) 765 PROC_UNLOCK(p); 766 return; 767 } 768 if (!proc_locked) 769 PROC_UNLOCK(p); 770 } 771 kqtimer_sched_callout(kc); 772 } 773 774 static void 775 filt_timerexpire(void *knx) 776 { 777 filt_timerexpire_l(knx, false); 778 } 779 780 /* 781 * data contains amount of time to sleep 782 */ 783 static int 784 filt_timervalidate(struct knote *kn, sbintime_t *to) 785 { 786 struct bintime bt; 787 sbintime_t sbt; 788 789 if (kn->kn_sdata < 0) 790 return (EINVAL); 791 if (kn->kn_sdata == 0 && (kn->kn_flags & EV_ONESHOT) == 0) 792 kn->kn_sdata = 1; 793 /* 794 * The only fflags values supported are the timer unit 795 * (precision) and the absolute time indicator. 796 */ 797 if ((kn->kn_sfflags & ~(NOTE_TIMER_PRECMASK | NOTE_ABSTIME)) != 0) 798 return (EINVAL); 799 800 *to = timer2sbintime(kn->kn_sdata, kn->kn_sfflags); 801 if (*to < 0) 802 return (EINVAL); 803 if ((kn->kn_sfflags & NOTE_ABSTIME) != 0) { 804 getboottimebin(&bt); 805 sbt = bttosbt(bt); 806 *to = MAX(0, *to - sbt); 807 } 808 return (0); 809 } 810 811 static int 812 filt_timerattach(struct knote *kn) 813 { 814 struct kq_timer_cb_data *kc; 815 sbintime_t to; 816 int error; 817 818 to = -1; 819 error = filt_timervalidate(kn, &to); 820 if (error != 0) 821 return (error); 822 KASSERT(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 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 kevent_freebsd11 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 kevent_freebsd11 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 kevent_freebsd11), 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, "kevent_freebsd11")); 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 /* 1506 * Prevent waiting with locks. Non-sleepable 1507 * allocation failures are handled in the loop, only 1508 * if the spare knote appears to be actually required. 1509 */ 1510 tkn = knote_alloc(mflag); 1511 } else { 1512 tkn = NULL; 1513 } 1514 1515 findkn: 1516 if (fops->f_isfd) { 1517 KASSERT(td != NULL, ("td is NULL")); 1518 if (kev->ident > INT_MAX) 1519 error = EBADF; 1520 else 1521 error = fget(td, kev->ident, &cap_event_rights, &fp); 1522 if (error) 1523 goto done; 1524 1525 if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops, 1526 kev->ident, M_NOWAIT) != 0) { 1527 /* try again */ 1528 fdrop(fp, td); 1529 fp = NULL; 1530 error = kqueue_expand(kq, fops, kev->ident, mflag); 1531 if (error) 1532 goto done; 1533 goto findkn; 1534 } 1535 1536 if (fp->f_type == DTYPE_KQUEUE) { 1537 /* 1538 * If we add some intelligence about what we are doing, 1539 * we should be able to support events on ourselves. 1540 * We need to know when we are doing this to prevent 1541 * getting both the knlist lock and the kq lock since 1542 * they are the same thing. 1543 */ 1544 if (fp->f_data == kq) { 1545 error = EINVAL; 1546 goto done; 1547 } 1548 1549 /* 1550 * Pre-lock the filedesc before the global 1551 * lock mutex, see the comment in 1552 * kqueue_close(). 1553 */ 1554 FILEDESC_XLOCK(td->td_proc->p_fd); 1555 filedesc_unlock = 1; 1556 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1557 } 1558 1559 KQ_LOCK(kq); 1560 if (kev->ident < kq->kq_knlistsize) { 1561 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link) 1562 if (kev->filter == kn->kn_filter) 1563 break; 1564 } 1565 } else { 1566 if ((kev->flags & EV_ADD) == EV_ADD) { 1567 error = kqueue_expand(kq, fops, kev->ident, mflag); 1568 if (error != 0) 1569 goto done; 1570 } 1571 1572 KQ_LOCK(kq); 1573 1574 /* 1575 * If possible, find an existing knote to use for this kevent. 1576 */ 1577 if (kev->filter == EVFILT_PROC && 1578 (kev->flags & (EV_FLAG1 | EV_FLAG2)) != 0) { 1579 /* This is an internal creation of a process tracking 1580 * note. Don't attempt to coalesce this with an 1581 * existing note. 1582 */ 1583 ; 1584 } else if (kq->kq_knhashmask != 0) { 1585 struct klist *list; 1586 1587 list = &kq->kq_knhash[ 1588 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)]; 1589 SLIST_FOREACH(kn, list, kn_link) 1590 if (kev->ident == kn->kn_id && 1591 kev->filter == kn->kn_filter) 1592 break; 1593 } 1594 } 1595 1596 /* knote is in the process of changing, wait for it to stabilize. */ 1597 if (kn != NULL && kn_in_flux(kn)) { 1598 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1599 if (filedesc_unlock) { 1600 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1601 filedesc_unlock = 0; 1602 } 1603 kq->kq_state |= KQ_FLUXWAIT; 1604 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0); 1605 if (fp != NULL) { 1606 fdrop(fp, td); 1607 fp = NULL; 1608 } 1609 goto findkn; 1610 } 1611 1612 /* 1613 * kn now contains the matching knote, or NULL if no match 1614 */ 1615 if (kn == NULL) { 1616 if (kev->flags & EV_ADD) { 1617 kn = tkn; 1618 tkn = NULL; 1619 if (kn == NULL) { 1620 KQ_UNLOCK(kq); 1621 error = ENOMEM; 1622 goto done; 1623 } 1624 kn->kn_fp = fp; 1625 kn->kn_kq = kq; 1626 kn->kn_fop = fops; 1627 /* 1628 * apply reference counts to knote structure, and 1629 * do not release it at the end of this routine. 1630 */ 1631 fops = NULL; 1632 fp = NULL; 1633 1634 kn->kn_sfflags = kev->fflags; 1635 kn->kn_sdata = kev->data; 1636 kev->fflags = 0; 1637 kev->data = 0; 1638 kn->kn_kevent = *kev; 1639 kn->kn_kevent.flags &= ~(EV_ADD | EV_DELETE | 1640 EV_ENABLE | EV_DISABLE | EV_FORCEONESHOT); 1641 kn->kn_status = KN_DETACHED; 1642 if ((kev->flags & EV_DISABLE) != 0) 1643 kn->kn_status |= KN_DISABLED; 1644 kn_enter_flux(kn); 1645 1646 error = knote_attach(kn, kq); 1647 KQ_UNLOCK(kq); 1648 if (error != 0) { 1649 tkn = kn; 1650 goto done; 1651 } 1652 1653 if ((error = kn->kn_fop->f_attach(kn)) != 0) { 1654 knote_drop_detached(kn, td); 1655 goto done; 1656 } 1657 knl = kn_list_lock(kn); 1658 goto done_ev_add; 1659 } else { 1660 /* No matching knote and the EV_ADD flag is not set. */ 1661 KQ_UNLOCK(kq); 1662 error = ENOENT; 1663 goto done; 1664 } 1665 } 1666 1667 if (kev->flags & EV_DELETE) { 1668 kn_enter_flux(kn); 1669 KQ_UNLOCK(kq); 1670 knote_drop(kn, td); 1671 goto done; 1672 } 1673 1674 if (kev->flags & EV_FORCEONESHOT) { 1675 kn->kn_flags |= EV_ONESHOT; 1676 KNOTE_ACTIVATE(kn, 1); 1677 } 1678 1679 if ((kev->flags & EV_ENABLE) != 0) 1680 kn->kn_status &= ~KN_DISABLED; 1681 else if ((kev->flags & EV_DISABLE) != 0) 1682 kn->kn_status |= KN_DISABLED; 1683 1684 /* 1685 * The user may change some filter values after the initial EV_ADD, 1686 * but doing so will not reset any filter which has already been 1687 * triggered. 1688 */ 1689 kn->kn_status |= KN_SCAN; 1690 kn_enter_flux(kn); 1691 KQ_UNLOCK(kq); 1692 knl = kn_list_lock(kn); 1693 kn->kn_kevent.udata = kev->udata; 1694 if (!fops->f_isfd && fops->f_touch != NULL) { 1695 fops->f_touch(kn, kev, EVENT_REGISTER); 1696 } else { 1697 kn->kn_sfflags = kev->fflags; 1698 kn->kn_sdata = kev->data; 1699 } 1700 1701 done_ev_add: 1702 /* 1703 * We can get here with kn->kn_knlist == NULL. This can happen when 1704 * the initial attach event decides that the event is "completed" 1705 * already, e.g., filt_procattach() is called on a zombie process. It 1706 * will call filt_proc() which will remove it from the list, and NULL 1707 * kn_knlist. 1708 * 1709 * KN_DISABLED will be stable while the knote is in flux, so the 1710 * unlocked read will not race with an update. 1711 */ 1712 if ((kn->kn_status & KN_DISABLED) == 0) 1713 event = kn->kn_fop->f_event(kn, 0); 1714 else 1715 event = 0; 1716 1717 KQ_LOCK(kq); 1718 if (event) 1719 kn->kn_status |= KN_ACTIVE; 1720 if ((kn->kn_status & (KN_ACTIVE | KN_DISABLED | KN_QUEUED)) == 1721 KN_ACTIVE) 1722 knote_enqueue(kn); 1723 kn->kn_status &= ~KN_SCAN; 1724 kn_leave_flux(kn); 1725 kn_list_unlock(knl); 1726 KQ_UNLOCK_FLUX(kq); 1727 1728 done: 1729 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1730 if (filedesc_unlock) 1731 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1732 if (fp != NULL) 1733 fdrop(fp, td); 1734 knote_free(tkn); 1735 if (fops != NULL) 1736 kqueue_fo_release(filt); 1737 return (error); 1738 } 1739 1740 static int 1741 kqueue_acquire(struct file *fp, struct kqueue **kqp) 1742 { 1743 int error; 1744 struct kqueue *kq; 1745 1746 error = 0; 1747 1748 kq = fp->f_data; 1749 if (fp->f_type != DTYPE_KQUEUE || kq == NULL) 1750 return (EBADF); 1751 *kqp = kq; 1752 KQ_LOCK(kq); 1753 if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) { 1754 KQ_UNLOCK(kq); 1755 return (EBADF); 1756 } 1757 kq->kq_refcnt++; 1758 KQ_UNLOCK(kq); 1759 1760 return error; 1761 } 1762 1763 static void 1764 kqueue_release(struct kqueue *kq, int locked) 1765 { 1766 if (locked) 1767 KQ_OWNED(kq); 1768 else 1769 KQ_LOCK(kq); 1770 kq->kq_refcnt--; 1771 if (kq->kq_refcnt == 1) 1772 wakeup(&kq->kq_refcnt); 1773 if (!locked) 1774 KQ_UNLOCK(kq); 1775 } 1776 1777 void 1778 kqueue_drain_schedtask(void) 1779 { 1780 taskqueue_quiesce(taskqueue_kqueue_ctx); 1781 } 1782 1783 static void 1784 kqueue_schedtask(struct kqueue *kq) 1785 { 1786 struct thread *td; 1787 1788 KQ_OWNED(kq); 1789 KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN), 1790 ("scheduling kqueue task while draining")); 1791 1792 if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) { 1793 taskqueue_enqueue(taskqueue_kqueue_ctx, &kq->kq_task); 1794 kq->kq_state |= KQ_TASKSCHED; 1795 td = curthread; 1796 thread_lock(td); 1797 td->td_flags |= TDF_ASTPENDING | TDF_KQTICKLED; 1798 thread_unlock(td); 1799 } 1800 } 1801 1802 /* 1803 * Expand the kq to make sure we have storage for fops/ident pair. 1804 * 1805 * Return 0 on success (or no work necessary), return errno on failure. 1806 */ 1807 static int 1808 kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident, 1809 int mflag) 1810 { 1811 struct klist *list, *tmp_knhash, *to_free; 1812 u_long tmp_knhashmask; 1813 int error, fd, size; 1814 1815 KQ_NOTOWNED(kq); 1816 1817 error = 0; 1818 to_free = NULL; 1819 if (fops->f_isfd) { 1820 fd = ident; 1821 if (kq->kq_knlistsize <= fd) { 1822 size = kq->kq_knlistsize; 1823 while (size <= fd) 1824 size += KQEXTENT; 1825 list = malloc(size * sizeof(*list), M_KQUEUE, mflag); 1826 if (list == NULL) 1827 return ENOMEM; 1828 KQ_LOCK(kq); 1829 if ((kq->kq_state & KQ_CLOSING) != 0) { 1830 to_free = list; 1831 error = EBADF; 1832 } else if (kq->kq_knlistsize > fd) { 1833 to_free = list; 1834 } else { 1835 if (kq->kq_knlist != NULL) { 1836 bcopy(kq->kq_knlist, list, 1837 kq->kq_knlistsize * sizeof(*list)); 1838 to_free = kq->kq_knlist; 1839 kq->kq_knlist = NULL; 1840 } 1841 bzero((caddr_t)list + 1842 kq->kq_knlistsize * sizeof(*list), 1843 (size - kq->kq_knlistsize) * sizeof(*list)); 1844 kq->kq_knlistsize = size; 1845 kq->kq_knlist = list; 1846 } 1847 KQ_UNLOCK(kq); 1848 } 1849 } else { 1850 if (kq->kq_knhashmask == 0) { 1851 tmp_knhash = hashinit_flags(KN_HASHSIZE, M_KQUEUE, 1852 &tmp_knhashmask, (mflag & M_WAITOK) != 0 ? 1853 HASH_WAITOK : HASH_NOWAIT); 1854 if (tmp_knhash == NULL) 1855 return (ENOMEM); 1856 KQ_LOCK(kq); 1857 if ((kq->kq_state & KQ_CLOSING) != 0) { 1858 to_free = tmp_knhash; 1859 error = EBADF; 1860 } else if (kq->kq_knhashmask == 0) { 1861 kq->kq_knhash = tmp_knhash; 1862 kq->kq_knhashmask = tmp_knhashmask; 1863 } else { 1864 to_free = tmp_knhash; 1865 } 1866 KQ_UNLOCK(kq); 1867 } 1868 } 1869 free(to_free, M_KQUEUE); 1870 1871 KQ_NOTOWNED(kq); 1872 return (error); 1873 } 1874 1875 static void 1876 kqueue_task(void *arg, int pending) 1877 { 1878 struct kqueue *kq; 1879 int haskqglobal; 1880 1881 haskqglobal = 0; 1882 kq = arg; 1883 1884 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1885 KQ_LOCK(kq); 1886 1887 KNOTE_LOCKED(&kq->kq_sel.si_note, 0); 1888 1889 kq->kq_state &= ~KQ_TASKSCHED; 1890 if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) { 1891 wakeup(&kq->kq_state); 1892 } 1893 KQ_UNLOCK(kq); 1894 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1895 } 1896 1897 /* 1898 * Scan, update kn_data (if not ONESHOT), and copyout triggered events. 1899 * We treat KN_MARKER knotes as if they are in flux. 1900 */ 1901 static int 1902 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops, 1903 const struct timespec *tsp, struct kevent *keva, struct thread *td) 1904 { 1905 struct kevent *kevp; 1906 struct knote *kn, *marker; 1907 struct knlist *knl; 1908 sbintime_t asbt, rsbt; 1909 int count, error, haskqglobal, influx, nkev, touch; 1910 1911 count = maxevents; 1912 nkev = 0; 1913 error = 0; 1914 haskqglobal = 0; 1915 1916 if (maxevents == 0) 1917 goto done_nl; 1918 if (maxevents < 0) { 1919 error = EINVAL; 1920 goto done_nl; 1921 } 1922 1923 rsbt = 0; 1924 if (tsp != NULL) { 1925 if (tsp->tv_sec < 0 || tsp->tv_nsec < 0 || 1926 tsp->tv_nsec >= 1000000000) { 1927 error = EINVAL; 1928 goto done_nl; 1929 } 1930 if (timespecisset(tsp)) { 1931 if (tsp->tv_sec <= INT32_MAX) { 1932 rsbt = tstosbt(*tsp); 1933 if (TIMESEL(&asbt, rsbt)) 1934 asbt += tc_tick_sbt; 1935 if (asbt <= SBT_MAX - rsbt) 1936 asbt += rsbt; 1937 else 1938 asbt = 0; 1939 rsbt >>= tc_precexp; 1940 } else 1941 asbt = 0; 1942 } else 1943 asbt = -1; 1944 } else 1945 asbt = 0; 1946 marker = knote_alloc(M_WAITOK); 1947 marker->kn_status = KN_MARKER; 1948 KQ_LOCK(kq); 1949 1950 retry: 1951 kevp = keva; 1952 if (kq->kq_count == 0) { 1953 if (asbt == -1) { 1954 error = EWOULDBLOCK; 1955 } else { 1956 kq->kq_state |= KQ_SLEEP; 1957 error = msleep_sbt(kq, &kq->kq_lock, PSOCK | PCATCH, 1958 "kqread", asbt, rsbt, C_ABSOLUTE); 1959 } 1960 if (error == 0) 1961 goto retry; 1962 /* don't restart after signals... */ 1963 if (error == ERESTART) 1964 error = EINTR; 1965 else if (error == EWOULDBLOCK) 1966 error = 0; 1967 goto done; 1968 } 1969 1970 TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); 1971 influx = 0; 1972 while (count) { 1973 KQ_OWNED(kq); 1974 kn = TAILQ_FIRST(&kq->kq_head); 1975 1976 if ((kn->kn_status == KN_MARKER && kn != marker) || 1977 kn_in_flux(kn)) { 1978 if (influx) { 1979 influx = 0; 1980 KQ_FLUX_WAKEUP(kq); 1981 } 1982 kq->kq_state |= KQ_FLUXWAIT; 1983 error = msleep(kq, &kq->kq_lock, PSOCK, 1984 "kqflxwt", 0); 1985 continue; 1986 } 1987 1988 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1989 if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) { 1990 kn->kn_status &= ~KN_QUEUED; 1991 kq->kq_count--; 1992 continue; 1993 } 1994 if (kn == marker) { 1995 KQ_FLUX_WAKEUP(kq); 1996 if (count == maxevents) 1997 goto retry; 1998 goto done; 1999 } 2000 KASSERT(!kn_in_flux(kn), 2001 ("knote %p is unexpectedly in flux", kn)); 2002 2003 if ((kn->kn_flags & EV_DROP) == EV_DROP) { 2004 kn->kn_status &= ~KN_QUEUED; 2005 kn_enter_flux(kn); 2006 kq->kq_count--; 2007 KQ_UNLOCK(kq); 2008 /* 2009 * We don't need to lock the list since we've 2010 * marked it as in flux. 2011 */ 2012 knote_drop(kn, td); 2013 KQ_LOCK(kq); 2014 continue; 2015 } else if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) { 2016 kn->kn_status &= ~KN_QUEUED; 2017 kn_enter_flux(kn); 2018 kq->kq_count--; 2019 KQ_UNLOCK(kq); 2020 /* 2021 * We don't need to lock the list since we've 2022 * marked the knote as being in flux. 2023 */ 2024 *kevp = kn->kn_kevent; 2025 knote_drop(kn, td); 2026 KQ_LOCK(kq); 2027 kn = NULL; 2028 } else { 2029 kn->kn_status |= KN_SCAN; 2030 kn_enter_flux(kn); 2031 KQ_UNLOCK(kq); 2032 if ((kn->kn_status & KN_KQUEUE) == KN_KQUEUE) 2033 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 2034 knl = kn_list_lock(kn); 2035 if (kn->kn_fop->f_event(kn, 0) == 0) { 2036 KQ_LOCK(kq); 2037 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 2038 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE | 2039 KN_SCAN); 2040 kn_leave_flux(kn); 2041 kq->kq_count--; 2042 kn_list_unlock(knl); 2043 influx = 1; 2044 continue; 2045 } 2046 touch = (!kn->kn_fop->f_isfd && 2047 kn->kn_fop->f_touch != NULL); 2048 if (touch) 2049 kn->kn_fop->f_touch(kn, kevp, EVENT_PROCESS); 2050 else 2051 *kevp = kn->kn_kevent; 2052 KQ_LOCK(kq); 2053 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 2054 if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) { 2055 /* 2056 * Manually clear knotes who weren't 2057 * 'touch'ed. 2058 */ 2059 if (touch == 0 && kn->kn_flags & EV_CLEAR) { 2060 kn->kn_data = 0; 2061 kn->kn_fflags = 0; 2062 } 2063 if (kn->kn_flags & EV_DISPATCH) 2064 kn->kn_status |= KN_DISABLED; 2065 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 2066 kq->kq_count--; 2067 } else 2068 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2069 2070 kn->kn_status &= ~KN_SCAN; 2071 kn_leave_flux(kn); 2072 kn_list_unlock(knl); 2073 influx = 1; 2074 } 2075 2076 /* we are returning a copy to the user */ 2077 kevp++; 2078 nkev++; 2079 count--; 2080 2081 if (nkev == KQ_NEVENTS) { 2082 influx = 0; 2083 KQ_UNLOCK_FLUX(kq); 2084 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 2085 nkev = 0; 2086 kevp = keva; 2087 KQ_LOCK(kq); 2088 if (error) 2089 break; 2090 } 2091 } 2092 TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); 2093 done: 2094 KQ_OWNED(kq); 2095 KQ_UNLOCK_FLUX(kq); 2096 knote_free(marker); 2097 done_nl: 2098 KQ_NOTOWNED(kq); 2099 if (nkev != 0) 2100 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 2101 td->td_retval[0] = maxevents - count; 2102 return (error); 2103 } 2104 2105 /*ARGSUSED*/ 2106 static int 2107 kqueue_ioctl(struct file *fp, u_long cmd, void *data, 2108 struct ucred *active_cred, struct thread *td) 2109 { 2110 /* 2111 * Enabling sigio causes two major problems: 2112 * 1) infinite recursion: 2113 * Synopsys: kevent is being used to track signals and have FIOASYNC 2114 * set. On receipt of a signal this will cause a kqueue to recurse 2115 * into itself over and over. Sending the sigio causes the kqueue 2116 * to become ready, which in turn posts sigio again, forever. 2117 * Solution: this can be solved by setting a flag in the kqueue that 2118 * we have a SIGIO in progress. 2119 * 2) locking problems: 2120 * Synopsys: Kqueue is a leaf subsystem, but adding signalling puts 2121 * us above the proc and pgrp locks. 2122 * Solution: Post a signal using an async mechanism, being sure to 2123 * record a generation count in the delivery so that we do not deliver 2124 * a signal to the wrong process. 2125 * 2126 * Note, these two mechanisms are somewhat mutually exclusive! 2127 */ 2128 #if 0 2129 struct kqueue *kq; 2130 2131 kq = fp->f_data; 2132 switch (cmd) { 2133 case FIOASYNC: 2134 if (*(int *)data) { 2135 kq->kq_state |= KQ_ASYNC; 2136 } else { 2137 kq->kq_state &= ~KQ_ASYNC; 2138 } 2139 return (0); 2140 2141 case FIOSETOWN: 2142 return (fsetown(*(int *)data, &kq->kq_sigio)); 2143 2144 case FIOGETOWN: 2145 *(int *)data = fgetown(&kq->kq_sigio); 2146 return (0); 2147 } 2148 #endif 2149 2150 return (ENOTTY); 2151 } 2152 2153 /*ARGSUSED*/ 2154 static int 2155 kqueue_poll(struct file *fp, int events, struct ucred *active_cred, 2156 struct thread *td) 2157 { 2158 struct kqueue *kq; 2159 int revents = 0; 2160 int error; 2161 2162 if ((error = kqueue_acquire(fp, &kq))) 2163 return POLLERR; 2164 2165 KQ_LOCK(kq); 2166 if (events & (POLLIN | POLLRDNORM)) { 2167 if (kq->kq_count) { 2168 revents |= events & (POLLIN | POLLRDNORM); 2169 } else { 2170 selrecord(td, &kq->kq_sel); 2171 if (SEL_WAITING(&kq->kq_sel)) 2172 kq->kq_state |= KQ_SEL; 2173 } 2174 } 2175 kqueue_release(kq, 1); 2176 KQ_UNLOCK(kq); 2177 return (revents); 2178 } 2179 2180 /*ARGSUSED*/ 2181 static int 2182 kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred, 2183 struct thread *td) 2184 { 2185 2186 bzero((void *)st, sizeof *st); 2187 /* 2188 * We no longer return kq_count because the unlocked value is useless. 2189 * If you spent all this time getting the count, why not spend your 2190 * syscall better by calling kevent? 2191 * 2192 * XXX - This is needed for libc_r. 2193 */ 2194 st->st_mode = S_IFIFO; 2195 return (0); 2196 } 2197 2198 static void 2199 kqueue_drain(struct kqueue *kq, struct thread *td) 2200 { 2201 struct knote *kn; 2202 int i; 2203 2204 KQ_LOCK(kq); 2205 2206 KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING, 2207 ("kqueue already closing")); 2208 kq->kq_state |= KQ_CLOSING; 2209 if (kq->kq_refcnt > 1) 2210 msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0); 2211 2212 KASSERT(kq->kq_refcnt == 1, ("other refs are out there!")); 2213 2214 KASSERT(knlist_empty(&kq->kq_sel.si_note), 2215 ("kqueue's knlist not empty")); 2216 2217 for (i = 0; i < kq->kq_knlistsize; i++) { 2218 while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) { 2219 if (kn_in_flux(kn)) { 2220 kq->kq_state |= KQ_FLUXWAIT; 2221 msleep(kq, &kq->kq_lock, PSOCK, "kqclo1", 0); 2222 continue; 2223 } 2224 kn_enter_flux(kn); 2225 KQ_UNLOCK(kq); 2226 knote_drop(kn, td); 2227 KQ_LOCK(kq); 2228 } 2229 } 2230 if (kq->kq_knhashmask != 0) { 2231 for (i = 0; i <= kq->kq_knhashmask; i++) { 2232 while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) { 2233 if (kn_in_flux(kn)) { 2234 kq->kq_state |= KQ_FLUXWAIT; 2235 msleep(kq, &kq->kq_lock, PSOCK, 2236 "kqclo2", 0); 2237 continue; 2238 } 2239 kn_enter_flux(kn); 2240 KQ_UNLOCK(kq); 2241 knote_drop(kn, td); 2242 KQ_LOCK(kq); 2243 } 2244 } 2245 } 2246 2247 if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) { 2248 kq->kq_state |= KQ_TASKDRAIN; 2249 msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0); 2250 } 2251 2252 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2253 selwakeuppri(&kq->kq_sel, PSOCK); 2254 if (!SEL_WAITING(&kq->kq_sel)) 2255 kq->kq_state &= ~KQ_SEL; 2256 } 2257 2258 KQ_UNLOCK(kq); 2259 } 2260 2261 static void 2262 kqueue_destroy(struct kqueue *kq) 2263 { 2264 2265 KASSERT(kq->kq_fdp == NULL, 2266 ("kqueue still attached to a file descriptor")); 2267 seldrain(&kq->kq_sel); 2268 knlist_destroy(&kq->kq_sel.si_note); 2269 mtx_destroy(&kq->kq_lock); 2270 2271 if (kq->kq_knhash != NULL) 2272 free(kq->kq_knhash, M_KQUEUE); 2273 if (kq->kq_knlist != NULL) 2274 free(kq->kq_knlist, M_KQUEUE); 2275 2276 funsetown(&kq->kq_sigio); 2277 } 2278 2279 /*ARGSUSED*/ 2280 static int 2281 kqueue_close(struct file *fp, struct thread *td) 2282 { 2283 struct kqueue *kq = fp->f_data; 2284 struct filedesc *fdp; 2285 int error; 2286 int filedesc_unlock; 2287 2288 if ((error = kqueue_acquire(fp, &kq))) 2289 return error; 2290 kqueue_drain(kq, td); 2291 2292 /* 2293 * We could be called due to the knote_drop() doing fdrop(), 2294 * called from kqueue_register(). In this case the global 2295 * lock is owned, and filedesc sx is locked before, to not 2296 * take the sleepable lock after non-sleepable. 2297 */ 2298 fdp = kq->kq_fdp; 2299 kq->kq_fdp = NULL; 2300 if (!sx_xlocked(FILEDESC_LOCK(fdp))) { 2301 FILEDESC_XLOCK(fdp); 2302 filedesc_unlock = 1; 2303 } else 2304 filedesc_unlock = 0; 2305 TAILQ_REMOVE(&fdp->fd_kqlist, kq, kq_list); 2306 if (filedesc_unlock) 2307 FILEDESC_XUNLOCK(fdp); 2308 2309 kqueue_destroy(kq); 2310 chgkqcnt(kq->kq_cred->cr_ruidinfo, -1, 0); 2311 crfree(kq->kq_cred); 2312 free(kq, M_KQUEUE); 2313 fp->f_data = NULL; 2314 2315 return (0); 2316 } 2317 2318 static int 2319 kqueue_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 2320 { 2321 2322 kif->kf_type = KF_TYPE_KQUEUE; 2323 return (0); 2324 } 2325 2326 static void 2327 kqueue_wakeup(struct kqueue *kq) 2328 { 2329 KQ_OWNED(kq); 2330 2331 if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) { 2332 kq->kq_state &= ~KQ_SLEEP; 2333 wakeup(kq); 2334 } 2335 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2336 selwakeuppri(&kq->kq_sel, PSOCK); 2337 if (!SEL_WAITING(&kq->kq_sel)) 2338 kq->kq_state &= ~KQ_SEL; 2339 } 2340 if (!knlist_empty(&kq->kq_sel.si_note)) 2341 kqueue_schedtask(kq); 2342 if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) { 2343 pgsigio(&kq->kq_sigio, SIGIO, 0); 2344 } 2345 } 2346 2347 /* 2348 * Walk down a list of knotes, activating them if their event has triggered. 2349 * 2350 * There is a possibility to optimize in the case of one kq watching another. 2351 * Instead of scheduling a task to wake it up, you could pass enough state 2352 * down the chain to make up the parent kqueue. Make this code functional 2353 * first. 2354 */ 2355 void 2356 knote(struct knlist *list, long hint, int lockflags) 2357 { 2358 struct kqueue *kq; 2359 struct knote *kn, *tkn; 2360 int error; 2361 2362 if (list == NULL) 2363 return; 2364 2365 KNL_ASSERT_LOCK(list, lockflags & KNF_LISTLOCKED); 2366 2367 if ((lockflags & KNF_LISTLOCKED) == 0) 2368 list->kl_lock(list->kl_lockarg); 2369 2370 /* 2371 * If we unlock the list lock (and enter influx), we can 2372 * eliminate the kqueue scheduling, but this will introduce 2373 * four lock/unlock's for each knote to test. Also, marker 2374 * would be needed to keep iteration position, since filters 2375 * or other threads could remove events. 2376 */ 2377 SLIST_FOREACH_SAFE(kn, &list->kl_list, kn_selnext, tkn) { 2378 kq = kn->kn_kq; 2379 KQ_LOCK(kq); 2380 if (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0) { 2381 /* 2382 * Do not process the influx notes, except for 2383 * the influx coming from the kq unlock in the 2384 * kqueue_scan(). In the later case, we do 2385 * not interfere with the scan, since the code 2386 * fragment in kqueue_scan() locks the knlist, 2387 * and cannot proceed until we finished. 2388 */ 2389 KQ_UNLOCK(kq); 2390 } else if ((lockflags & KNF_NOKQLOCK) != 0) { 2391 kn_enter_flux(kn); 2392 KQ_UNLOCK(kq); 2393 error = kn->kn_fop->f_event(kn, hint); 2394 KQ_LOCK(kq); 2395 kn_leave_flux(kn); 2396 if (error) 2397 KNOTE_ACTIVATE(kn, 1); 2398 KQ_UNLOCK_FLUX(kq); 2399 } else { 2400 if (kn->kn_fop->f_event(kn, hint)) 2401 KNOTE_ACTIVATE(kn, 1); 2402 KQ_UNLOCK(kq); 2403 } 2404 } 2405 if ((lockflags & KNF_LISTLOCKED) == 0) 2406 list->kl_unlock(list->kl_lockarg); 2407 } 2408 2409 /* 2410 * add a knote to a knlist 2411 */ 2412 void 2413 knlist_add(struct knlist *knl, struct knote *kn, int islocked) 2414 { 2415 2416 KNL_ASSERT_LOCK(knl, islocked); 2417 KQ_NOTOWNED(kn->kn_kq); 2418 KASSERT(kn_in_flux(kn), ("knote %p not in flux", kn)); 2419 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2420 ("knote %p was not detached", kn)); 2421 if (!islocked) 2422 knl->kl_lock(knl->kl_lockarg); 2423 SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext); 2424 if (!islocked) 2425 knl->kl_unlock(knl->kl_lockarg); 2426 KQ_LOCK(kn->kn_kq); 2427 kn->kn_knlist = knl; 2428 kn->kn_status &= ~KN_DETACHED; 2429 KQ_UNLOCK(kn->kn_kq); 2430 } 2431 2432 static void 2433 knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked, 2434 int kqislocked) 2435 { 2436 2437 KASSERT(!kqislocked || knlislocked, ("kq locked w/o knl locked")); 2438 KNL_ASSERT_LOCK(knl, knlislocked); 2439 mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED); 2440 KASSERT(kqislocked || kn_in_flux(kn), ("knote %p not in flux", kn)); 2441 KASSERT((kn->kn_status & KN_DETACHED) == 0, 2442 ("knote %p was already detached", kn)); 2443 if (!knlislocked) 2444 knl->kl_lock(knl->kl_lockarg); 2445 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext); 2446 kn->kn_knlist = NULL; 2447 if (!knlislocked) 2448 kn_list_unlock(knl); 2449 if (!kqislocked) 2450 KQ_LOCK(kn->kn_kq); 2451 kn->kn_status |= KN_DETACHED; 2452 if (!kqislocked) 2453 KQ_UNLOCK(kn->kn_kq); 2454 } 2455 2456 /* 2457 * remove knote from the specified knlist 2458 */ 2459 void 2460 knlist_remove(struct knlist *knl, struct knote *kn, int islocked) 2461 { 2462 2463 knlist_remove_kq(knl, kn, islocked, 0); 2464 } 2465 2466 int 2467 knlist_empty(struct knlist *knl) 2468 { 2469 2470 KNL_ASSERT_LOCKED(knl); 2471 return (SLIST_EMPTY(&knl->kl_list)); 2472 } 2473 2474 static struct mtx knlist_lock; 2475 MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects", 2476 MTX_DEF); 2477 static void knlist_mtx_lock(void *arg); 2478 static void knlist_mtx_unlock(void *arg); 2479 2480 static void 2481 knlist_mtx_lock(void *arg) 2482 { 2483 2484 mtx_lock((struct mtx *)arg); 2485 } 2486 2487 static void 2488 knlist_mtx_unlock(void *arg) 2489 { 2490 2491 mtx_unlock((struct mtx *)arg); 2492 } 2493 2494 static void 2495 knlist_mtx_assert_lock(void *arg, int what) 2496 { 2497 2498 if (what == LA_LOCKED) 2499 mtx_assert((struct mtx *)arg, MA_OWNED); 2500 else 2501 mtx_assert((struct mtx *)arg, MA_NOTOWNED); 2502 } 2503 2504 static void 2505 knlist_rw_rlock(void *arg) 2506 { 2507 2508 rw_rlock((struct rwlock *)arg); 2509 } 2510 2511 static void 2512 knlist_rw_runlock(void *arg) 2513 { 2514 2515 rw_runlock((struct rwlock *)arg); 2516 } 2517 2518 static void 2519 knlist_rw_assert_lock(void *arg, int what) 2520 { 2521 2522 if (what == LA_LOCKED) 2523 rw_assert((struct rwlock *)arg, RA_LOCKED); 2524 else 2525 rw_assert((struct rwlock *)arg, RA_UNLOCKED); 2526 } 2527 2528 void 2529 knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *), 2530 void (*kl_unlock)(void *), 2531 void (*kl_assert_lock)(void *, int)) 2532 { 2533 2534 if (lock == NULL) 2535 knl->kl_lockarg = &knlist_lock; 2536 else 2537 knl->kl_lockarg = lock; 2538 2539 if (kl_lock == NULL) 2540 knl->kl_lock = knlist_mtx_lock; 2541 else 2542 knl->kl_lock = kl_lock; 2543 if (kl_unlock == NULL) 2544 knl->kl_unlock = knlist_mtx_unlock; 2545 else 2546 knl->kl_unlock = kl_unlock; 2547 if (kl_assert_lock == NULL) 2548 knl->kl_assert_lock = knlist_mtx_assert_lock; 2549 else 2550 knl->kl_assert_lock = kl_assert_lock; 2551 2552 knl->kl_autodestroy = 0; 2553 SLIST_INIT(&knl->kl_list); 2554 } 2555 2556 void 2557 knlist_init_mtx(struct knlist *knl, struct mtx *lock) 2558 { 2559 2560 knlist_init(knl, lock, NULL, NULL, NULL); 2561 } 2562 2563 struct knlist * 2564 knlist_alloc(struct mtx *lock) 2565 { 2566 struct knlist *knl; 2567 2568 knl = malloc(sizeof(struct knlist), M_KQUEUE, M_WAITOK); 2569 knlist_init_mtx(knl, lock); 2570 return (knl); 2571 } 2572 2573 void 2574 knlist_init_rw_reader(struct knlist *knl, struct rwlock *lock) 2575 { 2576 2577 knlist_init(knl, lock, knlist_rw_rlock, knlist_rw_runlock, 2578 knlist_rw_assert_lock); 2579 } 2580 2581 void 2582 knlist_destroy(struct knlist *knl) 2583 { 2584 2585 KASSERT(KNLIST_EMPTY(knl), 2586 ("destroying knlist %p with knotes on it", knl)); 2587 } 2588 2589 void 2590 knlist_detach(struct knlist *knl) 2591 { 2592 2593 KNL_ASSERT_LOCKED(knl); 2594 knl->kl_autodestroy = 1; 2595 if (knlist_empty(knl)) { 2596 knlist_destroy(knl); 2597 free(knl, M_KQUEUE); 2598 } 2599 } 2600 2601 /* 2602 * Even if we are locked, we may need to drop the lock to allow any influx 2603 * knotes time to "settle". 2604 */ 2605 void 2606 knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn) 2607 { 2608 struct knote *kn, *kn2; 2609 struct kqueue *kq; 2610 2611 KASSERT(!knl->kl_autodestroy, ("cleardel for autodestroy %p", knl)); 2612 if (islocked) 2613 KNL_ASSERT_LOCKED(knl); 2614 else { 2615 KNL_ASSERT_UNLOCKED(knl); 2616 again: /* need to reacquire lock since we have dropped it */ 2617 knl->kl_lock(knl->kl_lockarg); 2618 } 2619 2620 SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) { 2621 kq = kn->kn_kq; 2622 KQ_LOCK(kq); 2623 if (kn_in_flux(kn)) { 2624 KQ_UNLOCK(kq); 2625 continue; 2626 } 2627 knlist_remove_kq(knl, kn, 1, 1); 2628 if (killkn) { 2629 kn_enter_flux(kn); 2630 KQ_UNLOCK(kq); 2631 knote_drop_detached(kn, td); 2632 } else { 2633 /* Make sure cleared knotes disappear soon */ 2634 kn->kn_flags |= EV_EOF | EV_ONESHOT; 2635 KQ_UNLOCK(kq); 2636 } 2637 kq = NULL; 2638 } 2639 2640 if (!SLIST_EMPTY(&knl->kl_list)) { 2641 /* there are still in flux knotes remaining */ 2642 kn = SLIST_FIRST(&knl->kl_list); 2643 kq = kn->kn_kq; 2644 KQ_LOCK(kq); 2645 KASSERT(kn_in_flux(kn), ("knote removed w/o list lock")); 2646 knl->kl_unlock(knl->kl_lockarg); 2647 kq->kq_state |= KQ_FLUXWAIT; 2648 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0); 2649 kq = NULL; 2650 goto again; 2651 } 2652 2653 if (islocked) 2654 KNL_ASSERT_LOCKED(knl); 2655 else { 2656 knl->kl_unlock(knl->kl_lockarg); 2657 KNL_ASSERT_UNLOCKED(knl); 2658 } 2659 } 2660 2661 /* 2662 * Remove all knotes referencing a specified fd must be called with FILEDESC 2663 * lock. This prevents a race where a new fd comes along and occupies the 2664 * entry and we attach a knote to the fd. 2665 */ 2666 void 2667 knote_fdclose(struct thread *td, int fd) 2668 { 2669 struct filedesc *fdp = td->td_proc->p_fd; 2670 struct kqueue *kq; 2671 struct knote *kn; 2672 int influx; 2673 2674 FILEDESC_XLOCK_ASSERT(fdp); 2675 2676 /* 2677 * We shouldn't have to worry about new kevents appearing on fd 2678 * since filedesc is locked. 2679 */ 2680 TAILQ_FOREACH(kq, &fdp->fd_kqlist, kq_list) { 2681 KQ_LOCK(kq); 2682 2683 again: 2684 influx = 0; 2685 while (kq->kq_knlistsize > fd && 2686 (kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) { 2687 if (kn_in_flux(kn)) { 2688 /* someone else might be waiting on our knote */ 2689 if (influx) 2690 wakeup(kq); 2691 kq->kq_state |= KQ_FLUXWAIT; 2692 msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0); 2693 goto again; 2694 } 2695 kn_enter_flux(kn); 2696 KQ_UNLOCK(kq); 2697 influx = 1; 2698 knote_drop(kn, td); 2699 KQ_LOCK(kq); 2700 } 2701 KQ_UNLOCK_FLUX(kq); 2702 } 2703 } 2704 2705 static int 2706 knote_attach(struct knote *kn, struct kqueue *kq) 2707 { 2708 struct klist *list; 2709 2710 KASSERT(kn_in_flux(kn), ("knote %p not marked influx", kn)); 2711 KQ_OWNED(kq); 2712 2713 if ((kq->kq_state & KQ_CLOSING) != 0) 2714 return (EBADF); 2715 if (kn->kn_fop->f_isfd) { 2716 if (kn->kn_id >= kq->kq_knlistsize) 2717 return (ENOMEM); 2718 list = &kq->kq_knlist[kn->kn_id]; 2719 } else { 2720 if (kq->kq_knhash == NULL) 2721 return (ENOMEM); 2722 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2723 } 2724 SLIST_INSERT_HEAD(list, kn, kn_link); 2725 return (0); 2726 } 2727 2728 static void 2729 knote_drop(struct knote *kn, struct thread *td) 2730 { 2731 2732 if ((kn->kn_status & KN_DETACHED) == 0) 2733 kn->kn_fop->f_detach(kn); 2734 knote_drop_detached(kn, td); 2735 } 2736 2737 static void 2738 knote_drop_detached(struct knote *kn, struct thread *td) 2739 { 2740 struct kqueue *kq; 2741 struct klist *list; 2742 2743 kq = kn->kn_kq; 2744 2745 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2746 ("knote %p still attached", kn)); 2747 KQ_NOTOWNED(kq); 2748 2749 KQ_LOCK(kq); 2750 KASSERT(kn->kn_influx == 1, 2751 ("knote_drop called on %p with influx %d", kn, kn->kn_influx)); 2752 2753 if (kn->kn_fop->f_isfd) 2754 list = &kq->kq_knlist[kn->kn_id]; 2755 else 2756 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2757 2758 if (!SLIST_EMPTY(list)) 2759 SLIST_REMOVE(list, kn, knote, kn_link); 2760 if (kn->kn_status & KN_QUEUED) 2761 knote_dequeue(kn); 2762 KQ_UNLOCK_FLUX(kq); 2763 2764 if (kn->kn_fop->f_isfd) { 2765 fdrop(kn->kn_fp, td); 2766 kn->kn_fp = NULL; 2767 } 2768 kqueue_fo_release(kn->kn_kevent.filter); 2769 kn->kn_fop = NULL; 2770 knote_free(kn); 2771 } 2772 2773 static void 2774 knote_enqueue(struct knote *kn) 2775 { 2776 struct kqueue *kq = kn->kn_kq; 2777 2778 KQ_OWNED(kn->kn_kq); 2779 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 2780 2781 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2782 kn->kn_status |= KN_QUEUED; 2783 kq->kq_count++; 2784 kqueue_wakeup(kq); 2785 } 2786 2787 static void 2788 knote_dequeue(struct knote *kn) 2789 { 2790 struct kqueue *kq = kn->kn_kq; 2791 2792 KQ_OWNED(kn->kn_kq); 2793 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 2794 2795 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 2796 kn->kn_status &= ~KN_QUEUED; 2797 kq->kq_count--; 2798 } 2799 2800 static void 2801 knote_init(void) 2802 { 2803 2804 knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL, 2805 NULL, NULL, UMA_ALIGN_PTR, 0); 2806 } 2807 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL); 2808 2809 static struct knote * 2810 knote_alloc(int mflag) 2811 { 2812 2813 return (uma_zalloc(knote_zone, mflag | M_ZERO)); 2814 } 2815 2816 static void 2817 knote_free(struct knote *kn) 2818 { 2819 2820 uma_zfree(knote_zone, kn); 2821 } 2822 2823 /* 2824 * Register the kev w/ the kq specified by fd. 2825 */ 2826 int 2827 kqfd_register(int fd, struct kevent *kev, struct thread *td, int mflag) 2828 { 2829 struct kqueue *kq; 2830 struct file *fp; 2831 cap_rights_t rights; 2832 int error; 2833 2834 error = fget(td, fd, cap_rights_init_one(&rights, CAP_KQUEUE_CHANGE), 2835 &fp); 2836 if (error != 0) 2837 return (error); 2838 if ((error = kqueue_acquire(fp, &kq)) != 0) 2839 goto noacquire; 2840 2841 error = kqueue_register(kq, kev, td, mflag); 2842 kqueue_release(kq, 0); 2843 2844 noacquire: 2845 fdrop(fp, td); 2846 return (error); 2847 }
Cache object: fd8213d5c4e272cb3c50542a0bf6470c
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