Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_event.c
Version:
- FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
SearchContext: - none - 3 - 10
1 /*- 2 * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org> 3 * Copyright 2004 John-Mark Gurney <jmg@FreeBSD.org> 4 * Copyright (c) 2009 Apple, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD: releng/11.1/sys/kern/kern_event.c 320290 2017-06-23 18:57:56Z kib $"); 31 32 #include "opt_ktrace.h" 33 #include "opt_kqueue.h" 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/capsicum.h> 38 #include <sys/kernel.h> 39 #include <sys/lock.h> 40 #include <sys/mutex.h> 41 #include <sys/rwlock.h> 42 #include <sys/proc.h> 43 #include <sys/malloc.h> 44 #include <sys/unistd.h> 45 #include <sys/file.h> 46 #include <sys/filedesc.h> 47 #include <sys/filio.h> 48 #include <sys/fcntl.h> 49 #include <sys/kthread.h> 50 #include <sys/selinfo.h> 51 #include <sys/queue.h> 52 #include <sys/event.h> 53 #include <sys/eventvar.h> 54 #include <sys/poll.h> 55 #include <sys/protosw.h> 56 #include <sys/resourcevar.h> 57 #include <sys/sigio.h> 58 #include <sys/signalvar.h> 59 #include <sys/socket.h> 60 #include <sys/socketvar.h> 61 #include <sys/stat.h> 62 #include <sys/sysctl.h> 63 #include <sys/sysproto.h> 64 #include <sys/syscallsubr.h> 65 #include <sys/taskqueue.h> 66 #include <sys/uio.h> 67 #include <sys/user.h> 68 #ifdef KTRACE 69 #include <sys/ktrace.h> 70 #endif 71 #include <machine/atomic.h> 72 73 #include <vm/uma.h> 74 75 static MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system"); 76 77 /* 78 * This lock is used if multiple kq locks are required. This possibly 79 * should be made into a per proc lock. 80 */ 81 static struct mtx kq_global; 82 MTX_SYSINIT(kq_global, &kq_global, "kqueue order", MTX_DEF); 83 #define KQ_GLOBAL_LOCK(lck, haslck) do { \ 84 if (!haslck) \ 85 mtx_lock(lck); \ 86 haslck = 1; \ 87 } while (0) 88 #define KQ_GLOBAL_UNLOCK(lck, haslck) do { \ 89 if (haslck) \ 90 mtx_unlock(lck); \ 91 haslck = 0; \ 92 } while (0) 93 94 TASKQUEUE_DEFINE_THREAD(kqueue_ctx); 95 96 static int kevent_copyout(void *arg, struct kevent *kevp, int count); 97 static int kevent_copyin(void *arg, struct kevent *kevp, int count); 98 static int kqueue_register(struct kqueue *kq, struct kevent *kev, 99 struct thread *td, int waitok); 100 static int kqueue_acquire(struct file *fp, struct kqueue **kqp); 101 static void kqueue_release(struct kqueue *kq, int locked); 102 static void kqueue_destroy(struct kqueue *kq); 103 static void kqueue_drain(struct kqueue *kq, struct thread *td); 104 static int kqueue_expand(struct kqueue *kq, struct filterops *fops, 105 uintptr_t ident, int waitok); 106 static void kqueue_task(void *arg, int pending); 107 static int kqueue_scan(struct kqueue *kq, int maxevents, 108 struct kevent_copyops *k_ops, 109 const struct timespec *timeout, 110 struct kevent *keva, struct thread *td); 111 static void kqueue_wakeup(struct kqueue *kq); 112 static struct filterops *kqueue_fo_find(int filt); 113 static void kqueue_fo_release(int filt); 114 115 static fo_ioctl_t kqueue_ioctl; 116 static fo_poll_t kqueue_poll; 117 static fo_kqfilter_t kqueue_kqfilter; 118 static fo_stat_t kqueue_stat; 119 static fo_close_t kqueue_close; 120 static fo_fill_kinfo_t kqueue_fill_kinfo; 121 122 static struct fileops kqueueops = { 123 .fo_read = invfo_rdwr, 124 .fo_write = invfo_rdwr, 125 .fo_truncate = invfo_truncate, 126 .fo_ioctl = kqueue_ioctl, 127 .fo_poll = kqueue_poll, 128 .fo_kqfilter = kqueue_kqfilter, 129 .fo_stat = kqueue_stat, 130 .fo_close = kqueue_close, 131 .fo_chmod = invfo_chmod, 132 .fo_chown = invfo_chown, 133 .fo_sendfile = invfo_sendfile, 134 .fo_fill_kinfo = kqueue_fill_kinfo, 135 }; 136 137 static int knote_attach(struct knote *kn, struct kqueue *kq); 138 static void knote_drop(struct knote *kn, struct thread *td); 139 static void knote_enqueue(struct knote *kn); 140 static void knote_dequeue(struct knote *kn); 141 static void knote_init(void); 142 static struct knote *knote_alloc(int waitok); 143 static void knote_free(struct knote *kn); 144 145 static void filt_kqdetach(struct knote *kn); 146 static int filt_kqueue(struct knote *kn, long hint); 147 static int filt_procattach(struct knote *kn); 148 static void filt_procdetach(struct knote *kn); 149 static int filt_proc(struct knote *kn, long hint); 150 static int filt_fileattach(struct knote *kn); 151 static void filt_timerexpire(void *knx); 152 static int filt_timerattach(struct knote *kn); 153 static void filt_timerdetach(struct knote *kn); 154 static int filt_timer(struct knote *kn, long hint); 155 static int filt_userattach(struct knote *kn); 156 static void filt_userdetach(struct knote *kn); 157 static int filt_user(struct knote *kn, long hint); 158 static void filt_usertouch(struct knote *kn, struct kevent *kev, 159 u_long type); 160 161 static struct filterops file_filtops = { 162 .f_isfd = 1, 163 .f_attach = filt_fileattach, 164 }; 165 static struct filterops kqread_filtops = { 166 .f_isfd = 1, 167 .f_detach = filt_kqdetach, 168 .f_event = filt_kqueue, 169 }; 170 /* XXX - move to kern_proc.c? */ 171 static struct filterops proc_filtops = { 172 .f_isfd = 0, 173 .f_attach = filt_procattach, 174 .f_detach = filt_procdetach, 175 .f_event = filt_proc, 176 }; 177 static struct filterops timer_filtops = { 178 .f_isfd = 0, 179 .f_attach = filt_timerattach, 180 .f_detach = filt_timerdetach, 181 .f_event = filt_timer, 182 }; 183 static struct filterops user_filtops = { 184 .f_attach = filt_userattach, 185 .f_detach = filt_userdetach, 186 .f_event = filt_user, 187 .f_touch = filt_usertouch, 188 }; 189 190 static uma_zone_t knote_zone; 191 static unsigned int kq_ncallouts = 0; 192 static unsigned int kq_calloutmax = 4 * 1024; 193 SYSCTL_UINT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW, 194 &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue"); 195 196 /* XXX - ensure not KN_INFLUX?? */ 197 #define KNOTE_ACTIVATE(kn, islock) do { \ 198 if ((islock)) \ 199 mtx_assert(&(kn)->kn_kq->kq_lock, MA_OWNED); \ 200 else \ 201 KQ_LOCK((kn)->kn_kq); \ 202 (kn)->kn_status |= KN_ACTIVE; \ 203 if (((kn)->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 204 knote_enqueue((kn)); \ 205 if (!(islock)) \ 206 KQ_UNLOCK((kn)->kn_kq); \ 207 } while(0) 208 #define KQ_LOCK(kq) do { \ 209 mtx_lock(&(kq)->kq_lock); \ 210 } while (0) 211 #define KQ_FLUX_WAKEUP(kq) do { \ 212 if (((kq)->kq_state & KQ_FLUXWAIT) == KQ_FLUXWAIT) { \ 213 (kq)->kq_state &= ~KQ_FLUXWAIT; \ 214 wakeup((kq)); \ 215 } \ 216 } while (0) 217 #define KQ_UNLOCK_FLUX(kq) do { \ 218 KQ_FLUX_WAKEUP(kq); \ 219 mtx_unlock(&(kq)->kq_lock); \ 220 } while (0) 221 #define KQ_UNLOCK(kq) do { \ 222 mtx_unlock(&(kq)->kq_lock); \ 223 } while (0) 224 #define KQ_OWNED(kq) do { \ 225 mtx_assert(&(kq)->kq_lock, MA_OWNED); \ 226 } while (0) 227 #define KQ_NOTOWNED(kq) do { \ 228 mtx_assert(&(kq)->kq_lock, MA_NOTOWNED); \ 229 } while (0) 230 231 static struct knlist * 232 kn_list_lock(struct knote *kn) 233 { 234 struct knlist *knl; 235 236 knl = kn->kn_knlist; 237 if (knl != NULL) 238 knl->kl_lock(knl->kl_lockarg); 239 return (knl); 240 } 241 242 static void 243 kn_list_unlock(struct knlist *knl) 244 { 245 bool do_free; 246 247 if (knl == NULL) 248 return; 249 do_free = knl->kl_autodestroy && knlist_empty(knl); 250 knl->kl_unlock(knl->kl_lockarg); 251 if (do_free) { 252 knlist_destroy(knl); 253 free(knl, M_KQUEUE); 254 } 255 } 256 257 #define KNL_ASSERT_LOCK(knl, islocked) do { \ 258 if (islocked) \ 259 KNL_ASSERT_LOCKED(knl); \ 260 else \ 261 KNL_ASSERT_UNLOCKED(knl); \ 262 } while (0) 263 #ifdef INVARIANTS 264 #define KNL_ASSERT_LOCKED(knl) do { \ 265 knl->kl_assert_locked((knl)->kl_lockarg); \ 266 } while (0) 267 #define KNL_ASSERT_UNLOCKED(knl) do { \ 268 knl->kl_assert_unlocked((knl)->kl_lockarg); \ 269 } while (0) 270 #else /* !INVARIANTS */ 271 #define KNL_ASSERT_LOCKED(knl) do {} while(0) 272 #define KNL_ASSERT_UNLOCKED(knl) do {} while (0) 273 #endif /* INVARIANTS */ 274 275 #ifndef KN_HASHSIZE 276 #define KN_HASHSIZE 64 /* XXX should be tunable */ 277 #endif 278 279 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 280 281 static int 282 filt_nullattach(struct knote *kn) 283 { 284 285 return (ENXIO); 286 }; 287 288 struct filterops null_filtops = { 289 .f_isfd = 0, 290 .f_attach = filt_nullattach, 291 }; 292 293 /* XXX - make SYSINIT to add these, and move into respective modules. */ 294 extern struct filterops sig_filtops; 295 extern struct filterops fs_filtops; 296 297 /* 298 * Table for for all system-defined filters. 299 */ 300 static struct mtx filterops_lock; 301 MTX_SYSINIT(kqueue_filterops, &filterops_lock, "protect sysfilt_ops", 302 MTX_DEF); 303 static struct { 304 struct filterops *for_fop; 305 int for_nolock; 306 int for_refcnt; 307 } sysfilt_ops[EVFILT_SYSCOUNT] = { 308 { &file_filtops, 1 }, /* EVFILT_READ */ 309 { &file_filtops, 1 }, /* EVFILT_WRITE */ 310 { &null_filtops }, /* EVFILT_AIO */ 311 { &file_filtops, 1 }, /* EVFILT_VNODE */ 312 { &proc_filtops, 1 }, /* EVFILT_PROC */ 313 { &sig_filtops, 1 }, /* EVFILT_SIGNAL */ 314 { &timer_filtops, 1 }, /* EVFILT_TIMER */ 315 { &file_filtops, 1 }, /* EVFILT_PROCDESC */ 316 { &fs_filtops, 1 }, /* EVFILT_FS */ 317 { &null_filtops }, /* EVFILT_LIO */ 318 { &user_filtops, 1 }, /* EVFILT_USER */ 319 { &null_filtops }, /* EVFILT_SENDFILE */ 320 }; 321 322 /* 323 * Simple redirection for all cdevsw style objects to call their fo_kqfilter 324 * method. 325 */ 326 static int 327 filt_fileattach(struct knote *kn) 328 { 329 330 return (fo_kqfilter(kn->kn_fp, kn)); 331 } 332 333 /*ARGSUSED*/ 334 static int 335 kqueue_kqfilter(struct file *fp, struct knote *kn) 336 { 337 struct kqueue *kq = kn->kn_fp->f_data; 338 339 if (kn->kn_filter != EVFILT_READ) 340 return (EINVAL); 341 342 kn->kn_status |= KN_KQUEUE; 343 kn->kn_fop = &kqread_filtops; 344 knlist_add(&kq->kq_sel.si_note, kn, 0); 345 346 return (0); 347 } 348 349 static void 350 filt_kqdetach(struct knote *kn) 351 { 352 struct kqueue *kq = kn->kn_fp->f_data; 353 354 knlist_remove(&kq->kq_sel.si_note, kn, 0); 355 } 356 357 /*ARGSUSED*/ 358 static int 359 filt_kqueue(struct knote *kn, long hint) 360 { 361 struct kqueue *kq = kn->kn_fp->f_data; 362 363 kn->kn_data = kq->kq_count; 364 return (kn->kn_data > 0); 365 } 366 367 /* XXX - move to kern_proc.c? */ 368 static int 369 filt_procattach(struct knote *kn) 370 { 371 struct proc *p; 372 int error; 373 bool exiting, immediate; 374 375 exiting = immediate = false; 376 p = pfind(kn->kn_id); 377 if (p == NULL && (kn->kn_sfflags & NOTE_EXIT)) { 378 p = zpfind(kn->kn_id); 379 exiting = true; 380 } else if (p != NULL && (p->p_flag & P_WEXIT)) { 381 exiting = true; 382 } 383 384 if (p == NULL) 385 return (ESRCH); 386 if ((error = p_cansee(curthread, p))) { 387 PROC_UNLOCK(p); 388 return (error); 389 } 390 391 kn->kn_ptr.p_proc = p; 392 kn->kn_flags |= EV_CLEAR; /* automatically set */ 393 394 /* 395 * Internal flag indicating registration done by kernel for the 396 * purposes of getting a NOTE_CHILD notification. 397 */ 398 if (kn->kn_flags & EV_FLAG2) { 399 kn->kn_flags &= ~EV_FLAG2; 400 kn->kn_data = kn->kn_sdata; /* ppid */ 401 kn->kn_fflags = NOTE_CHILD; 402 kn->kn_sfflags &= ~(NOTE_EXIT | NOTE_EXEC | NOTE_FORK); 403 immediate = true; /* Force immediate activation of child note. */ 404 } 405 /* 406 * Internal flag indicating registration done by kernel (for other than 407 * NOTE_CHILD). 408 */ 409 if (kn->kn_flags & EV_FLAG1) { 410 kn->kn_flags &= ~EV_FLAG1; 411 } 412 413 knlist_add(p->p_klist, kn, 1); 414 415 /* 416 * Immediately activate any child notes or, in the case of a zombie 417 * target process, exit notes. The latter is necessary to handle the 418 * case where the target process, e.g. a child, dies before the kevent 419 * is registered. 420 */ 421 if (immediate || (exiting && filt_proc(kn, NOTE_EXIT))) 422 KNOTE_ACTIVATE(kn, 0); 423 424 PROC_UNLOCK(p); 425 426 return (0); 427 } 428 429 /* 430 * The knote may be attached to a different process, which may exit, 431 * leaving nothing for the knote to be attached to. So when the process 432 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 433 * it will be deleted when read out. However, as part of the knote deletion, 434 * this routine is called, so a check is needed to avoid actually performing 435 * a detach, because the original process does not exist any more. 436 */ 437 /* XXX - move to kern_proc.c? */ 438 static void 439 filt_procdetach(struct knote *kn) 440 { 441 442 knlist_remove(kn->kn_knlist, kn, 0); 443 kn->kn_ptr.p_proc = NULL; 444 } 445 446 /* XXX - move to kern_proc.c? */ 447 static int 448 filt_proc(struct knote *kn, long hint) 449 { 450 struct proc *p; 451 u_int event; 452 453 p = kn->kn_ptr.p_proc; 454 if (p == NULL) /* already activated, from attach filter */ 455 return (0); 456 457 /* Mask off extra data. */ 458 event = (u_int)hint & NOTE_PCTRLMASK; 459 460 /* If the user is interested in this event, record it. */ 461 if (kn->kn_sfflags & event) 462 kn->kn_fflags |= event; 463 464 /* Process is gone, so flag the event as finished. */ 465 if (event == NOTE_EXIT) { 466 kn->kn_flags |= EV_EOF | EV_ONESHOT; 467 kn->kn_ptr.p_proc = NULL; 468 if (kn->kn_fflags & NOTE_EXIT) 469 kn->kn_data = KW_EXITCODE(p->p_xexit, p->p_xsig); 470 if (kn->kn_fflags == 0) 471 kn->kn_flags |= EV_DROP; 472 return (1); 473 } 474 475 return (kn->kn_fflags != 0); 476 } 477 478 /* 479 * Called when the process forked. It mostly does the same as the 480 * knote(), activating all knotes registered to be activated when the 481 * process forked. Additionally, for each knote attached to the 482 * parent, check whether user wants to track the new process. If so 483 * attach a new knote to it, and immediately report an event with the 484 * child's pid. 485 */ 486 void 487 knote_fork(struct knlist *list, int pid) 488 { 489 struct kqueue *kq; 490 struct knote *kn; 491 struct kevent kev; 492 int error; 493 494 if (list == NULL) 495 return; 496 list->kl_lock(list->kl_lockarg); 497 498 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { 499 kq = kn->kn_kq; 500 KQ_LOCK(kq); 501 if ((kn->kn_status & (KN_INFLUX | KN_SCAN)) == KN_INFLUX) { 502 KQ_UNLOCK(kq); 503 continue; 504 } 505 506 /* 507 * The same as knote(), activate the event. 508 */ 509 if ((kn->kn_sfflags & NOTE_TRACK) == 0) { 510 kn->kn_status |= KN_HASKQLOCK; 511 if (kn->kn_fop->f_event(kn, NOTE_FORK)) 512 KNOTE_ACTIVATE(kn, 1); 513 kn->kn_status &= ~KN_HASKQLOCK; 514 KQ_UNLOCK(kq); 515 continue; 516 } 517 518 /* 519 * The NOTE_TRACK case. In addition to the activation 520 * of the event, we need to register new events to 521 * track the child. Drop the locks in preparation for 522 * the call to kqueue_register(). 523 */ 524 kn->kn_status |= KN_INFLUX; 525 KQ_UNLOCK(kq); 526 list->kl_unlock(list->kl_lockarg); 527 528 /* 529 * Activate existing knote and register tracking knotes with 530 * new process. 531 * 532 * First register a knote to get just the child notice. This 533 * must be a separate note from a potential NOTE_EXIT 534 * notification since both NOTE_CHILD and NOTE_EXIT are defined 535 * to use the data field (in conflicting ways). 536 */ 537 kev.ident = pid; 538 kev.filter = kn->kn_filter; 539 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_ONESHOT | 540 EV_FLAG2; 541 kev.fflags = kn->kn_sfflags; 542 kev.data = kn->kn_id; /* parent */ 543 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 544 error = kqueue_register(kq, &kev, NULL, 0); 545 if (error) 546 kn->kn_fflags |= NOTE_TRACKERR; 547 548 /* 549 * Then register another knote to track other potential events 550 * from the new process. 551 */ 552 kev.ident = pid; 553 kev.filter = kn->kn_filter; 554 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 555 kev.fflags = kn->kn_sfflags; 556 kev.data = kn->kn_id; /* parent */ 557 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 558 error = kqueue_register(kq, &kev, NULL, 0); 559 if (error) 560 kn->kn_fflags |= NOTE_TRACKERR; 561 if (kn->kn_fop->f_event(kn, NOTE_FORK)) 562 KNOTE_ACTIVATE(kn, 0); 563 KQ_LOCK(kq); 564 kn->kn_status &= ~KN_INFLUX; 565 KQ_UNLOCK_FLUX(kq); 566 list->kl_lock(list->kl_lockarg); 567 } 568 list->kl_unlock(list->kl_lockarg); 569 } 570 571 /* 572 * XXX: EVFILT_TIMER should perhaps live in kern_time.c beside the 573 * interval timer support code. 574 */ 575 576 #define NOTE_TIMER_PRECMASK \ 577 (NOTE_SECONDS | NOTE_MSECONDS | NOTE_USECONDS | NOTE_NSECONDS) 578 579 static sbintime_t 580 timer2sbintime(intptr_t data, int flags) 581 { 582 int64_t secs; 583 584 /* 585 * Macros for converting to the fractional second portion of an 586 * sbintime_t using 64bit multiplication to improve precision. 587 */ 588 #define NS_TO_SBT(ns) (((ns) * (((uint64_t)1 << 63) / 500000000)) >> 32) 589 #define US_TO_SBT(us) (((us) * (((uint64_t)1 << 63) / 500000)) >> 32) 590 #define MS_TO_SBT(ms) (((ms) * (((uint64_t)1 << 63) / 500)) >> 32) 591 switch (flags & NOTE_TIMER_PRECMASK) { 592 case NOTE_SECONDS: 593 #ifdef __LP64__ 594 if (data > (SBT_MAX / SBT_1S)) 595 return (SBT_MAX); 596 #endif 597 return ((sbintime_t)data << 32); 598 case NOTE_MSECONDS: /* FALLTHROUGH */ 599 case 0: 600 if (data >= 1000) { 601 secs = data / 1000; 602 #ifdef __LP64__ 603 if (secs > (SBT_MAX / SBT_1S)) 604 return (SBT_MAX); 605 #endif 606 return (secs << 32 | MS_TO_SBT(data % 1000)); 607 } 608 return (MS_TO_SBT(data)); 609 case NOTE_USECONDS: 610 if (data >= 1000000) { 611 secs = data / 1000000; 612 #ifdef __LP64__ 613 if (secs > (SBT_MAX / SBT_1S)) 614 return (SBT_MAX); 615 #endif 616 return (secs << 32 | US_TO_SBT(data % 1000000)); 617 } 618 return (US_TO_SBT(data)); 619 case NOTE_NSECONDS: 620 if (data >= 1000000000) { 621 secs = data / 1000000000; 622 #ifdef __LP64__ 623 if (secs > (SBT_MAX / SBT_1S)) 624 return (SBT_MAX); 625 #endif 626 return (secs << 32 | US_TO_SBT(data % 1000000000)); 627 } 628 return (NS_TO_SBT(data)); 629 default: 630 break; 631 } 632 return (-1); 633 } 634 635 struct kq_timer_cb_data { 636 struct callout c; 637 sbintime_t next; /* next timer event fires at */ 638 sbintime_t to; /* precalculated timer period */ 639 }; 640 641 static void 642 filt_timerexpire(void *knx) 643 { 644 struct knote *kn; 645 struct kq_timer_cb_data *kc; 646 647 kn = knx; 648 kn->kn_data++; 649 KNOTE_ACTIVATE(kn, 0); /* XXX - handle locking */ 650 651 if ((kn->kn_flags & EV_ONESHOT) != 0) 652 return; 653 654 kc = kn->kn_ptr.p_v; 655 kc->next += kc->to; 656 callout_reset_sbt_on(&kc->c, kc->next, 0, filt_timerexpire, kn, 657 PCPU_GET(cpuid), C_ABSOLUTE); 658 } 659 660 /* 661 * data contains amount of time to sleep 662 */ 663 static int 664 filt_timerattach(struct knote *kn) 665 { 666 struct kq_timer_cb_data *kc; 667 sbintime_t to; 668 unsigned int ncallouts; 669 670 if (kn->kn_sdata < 0) 671 return (EINVAL); 672 if (kn->kn_sdata == 0 && (kn->kn_flags & EV_ONESHOT) == 0) 673 kn->kn_sdata = 1; 674 /* Only precision unit are supported in flags so far */ 675 if ((kn->kn_sfflags & ~NOTE_TIMER_PRECMASK) != 0) 676 return (EINVAL); 677 678 to = timer2sbintime(kn->kn_sdata, kn->kn_sfflags); 679 if (to < 0) 680 return (EINVAL); 681 682 do { 683 ncallouts = kq_ncallouts; 684 if (ncallouts >= kq_calloutmax) 685 return (ENOMEM); 686 } while (!atomic_cmpset_int(&kq_ncallouts, ncallouts, ncallouts + 1)); 687 688 kn->kn_flags |= EV_CLEAR; /* automatically set */ 689 kn->kn_status &= ~KN_DETACHED; /* knlist_add clears it */ 690 kn->kn_ptr.p_v = kc = malloc(sizeof(*kc), M_KQUEUE, M_WAITOK); 691 callout_init(&kc->c, 1); 692 kc->next = to + sbinuptime(); 693 kc->to = to; 694 callout_reset_sbt_on(&kc->c, kc->next, 0, filt_timerexpire, kn, 695 PCPU_GET(cpuid), C_ABSOLUTE); 696 697 return (0); 698 } 699 700 static void 701 filt_timerdetach(struct knote *kn) 702 { 703 struct kq_timer_cb_data *kc; 704 unsigned int old; 705 706 kc = kn->kn_ptr.p_v; 707 callout_drain(&kc->c); 708 free(kc, M_KQUEUE); 709 old = atomic_fetchadd_int(&kq_ncallouts, -1); 710 KASSERT(old > 0, ("Number of callouts cannot become negative")); 711 kn->kn_status |= KN_DETACHED; /* knlist_remove sets it */ 712 } 713 714 static int 715 filt_timer(struct knote *kn, long hint) 716 { 717 718 return (kn->kn_data != 0); 719 } 720 721 static int 722 filt_userattach(struct knote *kn) 723 { 724 725 /* 726 * EVFILT_USER knotes are not attached to anything in the kernel. 727 */ 728 kn->kn_hook = NULL; 729 if (kn->kn_fflags & NOTE_TRIGGER) 730 kn->kn_hookid = 1; 731 else 732 kn->kn_hookid = 0; 733 return (0); 734 } 735 736 static void 737 filt_userdetach(__unused struct knote *kn) 738 { 739 740 /* 741 * EVFILT_USER knotes are not attached to anything in the kernel. 742 */ 743 } 744 745 static int 746 filt_user(struct knote *kn, __unused long hint) 747 { 748 749 return (kn->kn_hookid); 750 } 751 752 static void 753 filt_usertouch(struct knote *kn, struct kevent *kev, u_long type) 754 { 755 u_int ffctrl; 756 757 switch (type) { 758 case EVENT_REGISTER: 759 if (kev->fflags & NOTE_TRIGGER) 760 kn->kn_hookid = 1; 761 762 ffctrl = kev->fflags & NOTE_FFCTRLMASK; 763 kev->fflags &= NOTE_FFLAGSMASK; 764 switch (ffctrl) { 765 case NOTE_FFNOP: 766 break; 767 768 case NOTE_FFAND: 769 kn->kn_sfflags &= kev->fflags; 770 break; 771 772 case NOTE_FFOR: 773 kn->kn_sfflags |= kev->fflags; 774 break; 775 776 case NOTE_FFCOPY: 777 kn->kn_sfflags = kev->fflags; 778 break; 779 780 default: 781 /* XXX Return error? */ 782 break; 783 } 784 kn->kn_sdata = kev->data; 785 if (kev->flags & EV_CLEAR) { 786 kn->kn_hookid = 0; 787 kn->kn_data = 0; 788 kn->kn_fflags = 0; 789 } 790 break; 791 792 case EVENT_PROCESS: 793 *kev = kn->kn_kevent; 794 kev->fflags = kn->kn_sfflags; 795 kev->data = kn->kn_sdata; 796 if (kn->kn_flags & EV_CLEAR) { 797 kn->kn_hookid = 0; 798 kn->kn_data = 0; 799 kn->kn_fflags = 0; 800 } 801 break; 802 803 default: 804 panic("filt_usertouch() - invalid type (%ld)", type); 805 break; 806 } 807 } 808 809 int 810 sys_kqueue(struct thread *td, struct kqueue_args *uap) 811 { 812 813 return (kern_kqueue(td, 0, NULL)); 814 } 815 816 static void 817 kqueue_init(struct kqueue *kq) 818 { 819 820 mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF | MTX_DUPOK); 821 TAILQ_INIT(&kq->kq_head); 822 knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock); 823 TASK_INIT(&kq->kq_task, 0, kqueue_task, kq); 824 } 825 826 int 827 kern_kqueue(struct thread *td, int flags, struct filecaps *fcaps) 828 { 829 struct filedesc *fdp; 830 struct kqueue *kq; 831 struct file *fp; 832 struct ucred *cred; 833 int fd, error; 834 835 fdp = td->td_proc->p_fd; 836 cred = td->td_ucred; 837 if (!chgkqcnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_KQUEUES))) 838 return (ENOMEM); 839 840 error = falloc_caps(td, &fp, &fd, flags, fcaps); 841 if (error != 0) { 842 chgkqcnt(cred->cr_ruidinfo, -1, 0); 843 return (error); 844 } 845 846 /* An extra reference on `fp' has been held for us by falloc(). */ 847 kq = malloc(sizeof *kq, M_KQUEUE, M_WAITOK | M_ZERO); 848 kqueue_init(kq); 849 kq->kq_fdp = fdp; 850 kq->kq_cred = crhold(cred); 851 852 FILEDESC_XLOCK(fdp); 853 TAILQ_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list); 854 FILEDESC_XUNLOCK(fdp); 855 856 finit(fp, FREAD | FWRITE, DTYPE_KQUEUE, kq, &kqueueops); 857 fdrop(fp, td); 858 859 td->td_retval[0] = fd; 860 return (0); 861 } 862 863 #ifdef KTRACE 864 static size_t 865 kev_iovlen(int n, u_int kgio) 866 { 867 868 if (n < 0 || n >= kgio / sizeof(struct kevent)) 869 return (kgio); 870 return (n * sizeof(struct kevent)); 871 } 872 #endif 873 874 #ifndef _SYS_SYSPROTO_H_ 875 struct kevent_args { 876 int fd; 877 const struct kevent *changelist; 878 int nchanges; 879 struct kevent *eventlist; 880 int nevents; 881 const struct timespec *timeout; 882 }; 883 #endif 884 int 885 sys_kevent(struct thread *td, struct kevent_args *uap) 886 { 887 struct timespec ts, *tsp; 888 struct kevent_copyops k_ops = { 889 .arg = uap, 890 .k_copyout = kevent_copyout, 891 .k_copyin = kevent_copyin, 892 }; 893 int error; 894 #ifdef KTRACE 895 struct uio ktruio; 896 struct iovec ktriov; 897 struct uio *ktruioin = NULL; 898 struct uio *ktruioout = NULL; 899 u_int kgio; 900 #endif 901 902 if (uap->timeout != NULL) { 903 error = copyin(uap->timeout, &ts, sizeof(ts)); 904 if (error) 905 return (error); 906 tsp = &ts; 907 } else 908 tsp = NULL; 909 910 #ifdef KTRACE 911 if (KTRPOINT(td, KTR_GENIO)) { 912 kgio = ktr_geniosize; 913 ktriov.iov_base = uap->changelist; 914 ktriov.iov_len = kev_iovlen(uap->nchanges, kgio); 915 ktruio = (struct uio){ .uio_iov = &ktriov, .uio_iovcnt = 1, 916 .uio_segflg = UIO_USERSPACE, .uio_rw = UIO_READ, 917 .uio_td = td }; 918 ktruioin = cloneuio(&ktruio); 919 ktriov.iov_base = uap->eventlist; 920 ktriov.iov_len = kev_iovlen(uap->nevents, kgio); 921 ktriov.iov_len = uap->nevents * sizeof(struct kevent); 922 ktruioout = cloneuio(&ktruio); 923 } 924 #endif 925 926 error = kern_kevent(td, uap->fd, uap->nchanges, uap->nevents, 927 &k_ops, tsp); 928 929 #ifdef KTRACE 930 if (ktruioin != NULL) { 931 ktruioin->uio_resid = kev_iovlen(uap->nchanges, kgio); 932 ktrgenio(uap->fd, UIO_WRITE, ktruioin, 0); 933 ktruioout->uio_resid = kev_iovlen(td->td_retval[0], kgio); 934 ktrgenio(uap->fd, UIO_READ, ktruioout, error); 935 } 936 #endif 937 938 return (error); 939 } 940 941 /* 942 * Copy 'count' items into the destination list pointed to by uap->eventlist. 943 */ 944 static int 945 kevent_copyout(void *arg, struct kevent *kevp, int count) 946 { 947 struct kevent_args *uap; 948 int error; 949 950 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 951 uap = (struct kevent_args *)arg; 952 953 error = copyout(kevp, uap->eventlist, count * sizeof *kevp); 954 if (error == 0) 955 uap->eventlist += count; 956 return (error); 957 } 958 959 /* 960 * Copy 'count' items from the list pointed to by uap->changelist. 961 */ 962 static int 963 kevent_copyin(void *arg, struct kevent *kevp, int count) 964 { 965 struct kevent_args *uap; 966 int error; 967 968 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 969 uap = (struct kevent_args *)arg; 970 971 error = copyin(uap->changelist, kevp, count * sizeof *kevp); 972 if (error == 0) 973 uap->changelist += count; 974 return (error); 975 } 976 977 int 978 kern_kevent(struct thread *td, int fd, int nchanges, int nevents, 979 struct kevent_copyops *k_ops, const struct timespec *timeout) 980 { 981 cap_rights_t rights; 982 struct file *fp; 983 int error; 984 985 cap_rights_init(&rights); 986 if (nchanges > 0) 987 cap_rights_set(&rights, CAP_KQUEUE_CHANGE); 988 if (nevents > 0) 989 cap_rights_set(&rights, CAP_KQUEUE_EVENT); 990 error = fget(td, fd, &rights, &fp); 991 if (error != 0) 992 return (error); 993 994 error = kern_kevent_fp(td, fp, nchanges, nevents, k_ops, timeout); 995 fdrop(fp, td); 996 997 return (error); 998 } 999 1000 static int 1001 kqueue_kevent(struct kqueue *kq, struct thread *td, int nchanges, int nevents, 1002 struct kevent_copyops *k_ops, const struct timespec *timeout) 1003 { 1004 struct kevent keva[KQ_NEVENTS]; 1005 struct kevent *kevp, *changes; 1006 int i, n, nerrors, error; 1007 1008 nerrors = 0; 1009 while (nchanges > 0) { 1010 n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges; 1011 error = k_ops->k_copyin(k_ops->arg, keva, n); 1012 if (error) 1013 return (error); 1014 changes = keva; 1015 for (i = 0; i < n; i++) { 1016 kevp = &changes[i]; 1017 if (!kevp->filter) 1018 continue; 1019 kevp->flags &= ~EV_SYSFLAGS; 1020 error = kqueue_register(kq, kevp, td, 1); 1021 if (error || (kevp->flags & EV_RECEIPT)) { 1022 if (nevents == 0) 1023 return (error); 1024 kevp->flags = EV_ERROR; 1025 kevp->data = error; 1026 (void)k_ops->k_copyout(k_ops->arg, kevp, 1); 1027 nevents--; 1028 nerrors++; 1029 } 1030 } 1031 nchanges -= n; 1032 } 1033 if (nerrors) { 1034 td->td_retval[0] = nerrors; 1035 return (0); 1036 } 1037 1038 return (kqueue_scan(kq, nevents, k_ops, timeout, keva, td)); 1039 } 1040 1041 int 1042 kern_kevent_fp(struct thread *td, struct file *fp, int nchanges, int nevents, 1043 struct kevent_copyops *k_ops, const struct timespec *timeout) 1044 { 1045 struct kqueue *kq; 1046 int error; 1047 1048 error = kqueue_acquire(fp, &kq); 1049 if (error != 0) 1050 return (error); 1051 error = kqueue_kevent(kq, td, nchanges, nevents, k_ops, timeout); 1052 kqueue_release(kq, 0); 1053 return (error); 1054 } 1055 1056 /* 1057 * Performs a kevent() call on a temporarily created kqueue. This can be 1058 * used to perform one-shot polling, similar to poll() and select(). 1059 */ 1060 int 1061 kern_kevent_anonymous(struct thread *td, int nevents, 1062 struct kevent_copyops *k_ops) 1063 { 1064 struct kqueue kq = {}; 1065 int error; 1066 1067 kqueue_init(&kq); 1068 kq.kq_refcnt = 1; 1069 error = kqueue_kevent(&kq, td, nevents, nevents, k_ops, NULL); 1070 kqueue_drain(&kq, td); 1071 kqueue_destroy(&kq); 1072 return (error); 1073 } 1074 1075 int 1076 kqueue_add_filteropts(int filt, struct filterops *filtops) 1077 { 1078 int error; 1079 1080 error = 0; 1081 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) { 1082 printf( 1083 "trying to add a filterop that is out of range: %d is beyond %d\n", 1084 ~filt, EVFILT_SYSCOUNT); 1085 return EINVAL; 1086 } 1087 mtx_lock(&filterops_lock); 1088 if (sysfilt_ops[~filt].for_fop != &null_filtops && 1089 sysfilt_ops[~filt].for_fop != NULL) 1090 error = EEXIST; 1091 else { 1092 sysfilt_ops[~filt].for_fop = filtops; 1093 sysfilt_ops[~filt].for_refcnt = 0; 1094 } 1095 mtx_unlock(&filterops_lock); 1096 1097 return (error); 1098 } 1099 1100 int 1101 kqueue_del_filteropts(int filt) 1102 { 1103 int error; 1104 1105 error = 0; 1106 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1107 return EINVAL; 1108 1109 mtx_lock(&filterops_lock); 1110 if (sysfilt_ops[~filt].for_fop == &null_filtops || 1111 sysfilt_ops[~filt].for_fop == NULL) 1112 error = EINVAL; 1113 else if (sysfilt_ops[~filt].for_refcnt != 0) 1114 error = EBUSY; 1115 else { 1116 sysfilt_ops[~filt].for_fop = &null_filtops; 1117 sysfilt_ops[~filt].for_refcnt = 0; 1118 } 1119 mtx_unlock(&filterops_lock); 1120 1121 return error; 1122 } 1123 1124 static struct filterops * 1125 kqueue_fo_find(int filt) 1126 { 1127 1128 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1129 return NULL; 1130 1131 if (sysfilt_ops[~filt].for_nolock) 1132 return sysfilt_ops[~filt].for_fop; 1133 1134 mtx_lock(&filterops_lock); 1135 sysfilt_ops[~filt].for_refcnt++; 1136 if (sysfilt_ops[~filt].for_fop == NULL) 1137 sysfilt_ops[~filt].for_fop = &null_filtops; 1138 mtx_unlock(&filterops_lock); 1139 1140 return sysfilt_ops[~filt].for_fop; 1141 } 1142 1143 static void 1144 kqueue_fo_release(int filt) 1145 { 1146 1147 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1148 return; 1149 1150 if (sysfilt_ops[~filt].for_nolock) 1151 return; 1152 1153 mtx_lock(&filterops_lock); 1154 KASSERT(sysfilt_ops[~filt].for_refcnt > 0, 1155 ("filter object refcount not valid on release")); 1156 sysfilt_ops[~filt].for_refcnt--; 1157 mtx_unlock(&filterops_lock); 1158 } 1159 1160 /* 1161 * A ref to kq (obtained via kqueue_acquire) must be held. waitok will 1162 * influence if memory allocation should wait. Make sure it is 0 if you 1163 * hold any mutexes. 1164 */ 1165 static int 1166 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, int waitok) 1167 { 1168 struct filterops *fops; 1169 struct file *fp; 1170 struct knote *kn, *tkn; 1171 struct knlist *knl; 1172 cap_rights_t rights; 1173 int error, filt, event; 1174 int haskqglobal, filedesc_unlock; 1175 1176 if ((kev->flags & (EV_ENABLE | EV_DISABLE)) == (EV_ENABLE | EV_DISABLE)) 1177 return (EINVAL); 1178 1179 fp = NULL; 1180 kn = NULL; 1181 knl = NULL; 1182 error = 0; 1183 haskqglobal = 0; 1184 filedesc_unlock = 0; 1185 1186 filt = kev->filter; 1187 fops = kqueue_fo_find(filt); 1188 if (fops == NULL) 1189 return EINVAL; 1190 1191 if (kev->flags & EV_ADD) { 1192 /* 1193 * Prevent waiting with locks. Non-sleepable 1194 * allocation failures are handled in the loop, only 1195 * if the spare knote appears to be actually required. 1196 */ 1197 tkn = knote_alloc(waitok); 1198 } else { 1199 tkn = NULL; 1200 } 1201 1202 findkn: 1203 if (fops->f_isfd) { 1204 KASSERT(td != NULL, ("td is NULL")); 1205 if (kev->ident > INT_MAX) 1206 error = EBADF; 1207 else 1208 error = fget(td, kev->ident, 1209 cap_rights_init(&rights, CAP_EVENT), &fp); 1210 if (error) 1211 goto done; 1212 1213 if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops, 1214 kev->ident, 0) != 0) { 1215 /* try again */ 1216 fdrop(fp, td); 1217 fp = NULL; 1218 error = kqueue_expand(kq, fops, kev->ident, waitok); 1219 if (error) 1220 goto done; 1221 goto findkn; 1222 } 1223 1224 if (fp->f_type == DTYPE_KQUEUE) { 1225 /* 1226 * If we add some intelligence about what we are doing, 1227 * we should be able to support events on ourselves. 1228 * We need to know when we are doing this to prevent 1229 * getting both the knlist lock and the kq lock since 1230 * they are the same thing. 1231 */ 1232 if (fp->f_data == kq) { 1233 error = EINVAL; 1234 goto done; 1235 } 1236 1237 /* 1238 * Pre-lock the filedesc before the global 1239 * lock mutex, see the comment in 1240 * kqueue_close(). 1241 */ 1242 FILEDESC_XLOCK(td->td_proc->p_fd); 1243 filedesc_unlock = 1; 1244 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1245 } 1246 1247 KQ_LOCK(kq); 1248 if (kev->ident < kq->kq_knlistsize) { 1249 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link) 1250 if (kev->filter == kn->kn_filter) 1251 break; 1252 } 1253 } else { 1254 if ((kev->flags & EV_ADD) == EV_ADD) 1255 kqueue_expand(kq, fops, kev->ident, waitok); 1256 1257 KQ_LOCK(kq); 1258 1259 /* 1260 * If possible, find an existing knote to use for this kevent. 1261 */ 1262 if (kev->filter == EVFILT_PROC && 1263 (kev->flags & (EV_FLAG1 | EV_FLAG2)) != 0) { 1264 /* This is an internal creation of a process tracking 1265 * note. Don't attempt to coalesce this with an 1266 * existing note. 1267 */ 1268 ; 1269 } else if (kq->kq_knhashmask != 0) { 1270 struct klist *list; 1271 1272 list = &kq->kq_knhash[ 1273 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)]; 1274 SLIST_FOREACH(kn, list, kn_link) 1275 if (kev->ident == kn->kn_id && 1276 kev->filter == kn->kn_filter) 1277 break; 1278 } 1279 } 1280 1281 /* knote is in the process of changing, wait for it to stabilize. */ 1282 if (kn != NULL && (kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1283 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1284 if (filedesc_unlock) { 1285 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1286 filedesc_unlock = 0; 1287 } 1288 kq->kq_state |= KQ_FLUXWAIT; 1289 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0); 1290 if (fp != NULL) { 1291 fdrop(fp, td); 1292 fp = NULL; 1293 } 1294 goto findkn; 1295 } 1296 1297 /* 1298 * kn now contains the matching knote, or NULL if no match 1299 */ 1300 if (kn == NULL) { 1301 if (kev->flags & EV_ADD) { 1302 kn = tkn; 1303 tkn = NULL; 1304 if (kn == NULL) { 1305 KQ_UNLOCK(kq); 1306 error = ENOMEM; 1307 goto done; 1308 } 1309 kn->kn_fp = fp; 1310 kn->kn_kq = kq; 1311 kn->kn_fop = fops; 1312 /* 1313 * apply reference counts to knote structure, and 1314 * do not release it at the end of this routine. 1315 */ 1316 fops = NULL; 1317 fp = NULL; 1318 1319 kn->kn_sfflags = kev->fflags; 1320 kn->kn_sdata = kev->data; 1321 kev->fflags = 0; 1322 kev->data = 0; 1323 kn->kn_kevent = *kev; 1324 kn->kn_kevent.flags &= ~(EV_ADD | EV_DELETE | 1325 EV_ENABLE | EV_DISABLE | EV_FORCEONESHOT); 1326 kn->kn_status = KN_INFLUX|KN_DETACHED; 1327 1328 error = knote_attach(kn, kq); 1329 KQ_UNLOCK(kq); 1330 if (error != 0) { 1331 tkn = kn; 1332 goto done; 1333 } 1334 1335 if ((error = kn->kn_fop->f_attach(kn)) != 0) { 1336 knote_drop(kn, td); 1337 goto done; 1338 } 1339 knl = kn_list_lock(kn); 1340 goto done_ev_add; 1341 } else { 1342 /* No matching knote and the EV_ADD flag is not set. */ 1343 KQ_UNLOCK(kq); 1344 error = ENOENT; 1345 goto done; 1346 } 1347 } 1348 1349 if (kev->flags & EV_DELETE) { 1350 kn->kn_status |= KN_INFLUX; 1351 KQ_UNLOCK(kq); 1352 if (!(kn->kn_status & KN_DETACHED)) 1353 kn->kn_fop->f_detach(kn); 1354 knote_drop(kn, td); 1355 goto done; 1356 } 1357 1358 if (kev->flags & EV_FORCEONESHOT) { 1359 kn->kn_flags |= EV_ONESHOT; 1360 KNOTE_ACTIVATE(kn, 1); 1361 } 1362 1363 /* 1364 * The user may change some filter values after the initial EV_ADD, 1365 * but doing so will not reset any filter which has already been 1366 * triggered. 1367 */ 1368 kn->kn_status |= KN_INFLUX | KN_SCAN; 1369 KQ_UNLOCK(kq); 1370 knl = kn_list_lock(kn); 1371 kn->kn_kevent.udata = kev->udata; 1372 if (!fops->f_isfd && fops->f_touch != NULL) { 1373 fops->f_touch(kn, kev, EVENT_REGISTER); 1374 } else { 1375 kn->kn_sfflags = kev->fflags; 1376 kn->kn_sdata = kev->data; 1377 } 1378 1379 /* 1380 * We can get here with kn->kn_knlist == NULL. This can happen when 1381 * the initial attach event decides that the event is "completed" 1382 * already. i.e. filt_procattach is called on a zombie process. It 1383 * will call filt_proc which will remove it from the list, and NULL 1384 * kn_knlist. 1385 */ 1386 done_ev_add: 1387 if ((kev->flags & EV_ENABLE) != 0) 1388 kn->kn_status &= ~KN_DISABLED; 1389 else if ((kev->flags & EV_DISABLE) != 0) 1390 kn->kn_status |= KN_DISABLED; 1391 1392 if ((kn->kn_status & KN_DISABLED) == 0) 1393 event = kn->kn_fop->f_event(kn, 0); 1394 else 1395 event = 0; 1396 1397 KQ_LOCK(kq); 1398 if (event) 1399 kn->kn_status |= KN_ACTIVE; 1400 if ((kn->kn_status & (KN_ACTIVE | KN_DISABLED | KN_QUEUED)) == 1401 KN_ACTIVE) 1402 knote_enqueue(kn); 1403 kn->kn_status &= ~(KN_INFLUX | KN_SCAN); 1404 kn_list_unlock(knl); 1405 KQ_UNLOCK_FLUX(kq); 1406 1407 done: 1408 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1409 if (filedesc_unlock) 1410 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1411 if (fp != NULL) 1412 fdrop(fp, td); 1413 knote_free(tkn); 1414 if (fops != NULL) 1415 kqueue_fo_release(filt); 1416 return (error); 1417 } 1418 1419 static int 1420 kqueue_acquire(struct file *fp, struct kqueue **kqp) 1421 { 1422 int error; 1423 struct kqueue *kq; 1424 1425 error = 0; 1426 1427 kq = fp->f_data; 1428 if (fp->f_type != DTYPE_KQUEUE || kq == NULL) 1429 return (EBADF); 1430 *kqp = kq; 1431 KQ_LOCK(kq); 1432 if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) { 1433 KQ_UNLOCK(kq); 1434 return (EBADF); 1435 } 1436 kq->kq_refcnt++; 1437 KQ_UNLOCK(kq); 1438 1439 return error; 1440 } 1441 1442 static void 1443 kqueue_release(struct kqueue *kq, int locked) 1444 { 1445 if (locked) 1446 KQ_OWNED(kq); 1447 else 1448 KQ_LOCK(kq); 1449 kq->kq_refcnt--; 1450 if (kq->kq_refcnt == 1) 1451 wakeup(&kq->kq_refcnt); 1452 if (!locked) 1453 KQ_UNLOCK(kq); 1454 } 1455 1456 static void 1457 kqueue_schedtask(struct kqueue *kq) 1458 { 1459 1460 KQ_OWNED(kq); 1461 KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN), 1462 ("scheduling kqueue task while draining")); 1463 1464 if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) { 1465 taskqueue_enqueue(taskqueue_kqueue_ctx, &kq->kq_task); 1466 kq->kq_state |= KQ_TASKSCHED; 1467 } 1468 } 1469 1470 /* 1471 * Expand the kq to make sure we have storage for fops/ident pair. 1472 * 1473 * Return 0 on success (or no work necessary), return errno on failure. 1474 * 1475 * Not calling hashinit w/ waitok (proper malloc flag) should be safe. 1476 * If kqueue_register is called from a non-fd context, there usually/should 1477 * be no locks held. 1478 */ 1479 static int 1480 kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident, 1481 int waitok) 1482 { 1483 struct klist *list, *tmp_knhash, *to_free; 1484 u_long tmp_knhashmask; 1485 int size; 1486 int fd; 1487 int mflag = waitok ? M_WAITOK : M_NOWAIT; 1488 1489 KQ_NOTOWNED(kq); 1490 1491 to_free = NULL; 1492 if (fops->f_isfd) { 1493 fd = ident; 1494 if (kq->kq_knlistsize <= fd) { 1495 size = kq->kq_knlistsize; 1496 while (size <= fd) 1497 size += KQEXTENT; 1498 list = malloc(size * sizeof(*list), M_KQUEUE, mflag); 1499 if (list == NULL) 1500 return ENOMEM; 1501 KQ_LOCK(kq); 1502 if (kq->kq_knlistsize > fd) { 1503 to_free = list; 1504 list = NULL; 1505 } else { 1506 if (kq->kq_knlist != NULL) { 1507 bcopy(kq->kq_knlist, list, 1508 kq->kq_knlistsize * sizeof(*list)); 1509 to_free = kq->kq_knlist; 1510 kq->kq_knlist = NULL; 1511 } 1512 bzero((caddr_t)list + 1513 kq->kq_knlistsize * sizeof(*list), 1514 (size - kq->kq_knlistsize) * sizeof(*list)); 1515 kq->kq_knlistsize = size; 1516 kq->kq_knlist = list; 1517 } 1518 KQ_UNLOCK(kq); 1519 } 1520 } else { 1521 if (kq->kq_knhashmask == 0) { 1522 tmp_knhash = hashinit(KN_HASHSIZE, M_KQUEUE, 1523 &tmp_knhashmask); 1524 if (tmp_knhash == NULL) 1525 return ENOMEM; 1526 KQ_LOCK(kq); 1527 if (kq->kq_knhashmask == 0) { 1528 kq->kq_knhash = tmp_knhash; 1529 kq->kq_knhashmask = tmp_knhashmask; 1530 } else { 1531 to_free = tmp_knhash; 1532 } 1533 KQ_UNLOCK(kq); 1534 } 1535 } 1536 free(to_free, M_KQUEUE); 1537 1538 KQ_NOTOWNED(kq); 1539 return 0; 1540 } 1541 1542 static void 1543 kqueue_task(void *arg, int pending) 1544 { 1545 struct kqueue *kq; 1546 int haskqglobal; 1547 1548 haskqglobal = 0; 1549 kq = arg; 1550 1551 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1552 KQ_LOCK(kq); 1553 1554 KNOTE_LOCKED(&kq->kq_sel.si_note, 0); 1555 1556 kq->kq_state &= ~KQ_TASKSCHED; 1557 if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) { 1558 wakeup(&kq->kq_state); 1559 } 1560 KQ_UNLOCK(kq); 1561 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1562 } 1563 1564 /* 1565 * Scan, update kn_data (if not ONESHOT), and copyout triggered events. 1566 * We treat KN_MARKER knotes as if they are INFLUX. 1567 */ 1568 static int 1569 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops, 1570 const struct timespec *tsp, struct kevent *keva, struct thread *td) 1571 { 1572 struct kevent *kevp; 1573 struct knote *kn, *marker; 1574 struct knlist *knl; 1575 sbintime_t asbt, rsbt; 1576 int count, error, haskqglobal, influx, nkev, touch; 1577 1578 count = maxevents; 1579 nkev = 0; 1580 error = 0; 1581 haskqglobal = 0; 1582 1583 if (maxevents == 0) 1584 goto done_nl; 1585 1586 rsbt = 0; 1587 if (tsp != NULL) { 1588 if (tsp->tv_sec < 0 || tsp->tv_nsec < 0 || 1589 tsp->tv_nsec >= 1000000000) { 1590 error = EINVAL; 1591 goto done_nl; 1592 } 1593 if (timespecisset(tsp)) { 1594 if (tsp->tv_sec <= INT32_MAX) { 1595 rsbt = tstosbt(*tsp); 1596 if (TIMESEL(&asbt, rsbt)) 1597 asbt += tc_tick_sbt; 1598 if (asbt <= SBT_MAX - rsbt) 1599 asbt += rsbt; 1600 else 1601 asbt = 0; 1602 rsbt >>= tc_precexp; 1603 } else 1604 asbt = 0; 1605 } else 1606 asbt = -1; 1607 } else 1608 asbt = 0; 1609 marker = knote_alloc(1); 1610 marker->kn_status = KN_MARKER; 1611 KQ_LOCK(kq); 1612 1613 retry: 1614 kevp = keva; 1615 if (kq->kq_count == 0) { 1616 if (asbt == -1) { 1617 error = EWOULDBLOCK; 1618 } else { 1619 kq->kq_state |= KQ_SLEEP; 1620 error = msleep_sbt(kq, &kq->kq_lock, PSOCK | PCATCH, 1621 "kqread", asbt, rsbt, C_ABSOLUTE); 1622 } 1623 if (error == 0) 1624 goto retry; 1625 /* don't restart after signals... */ 1626 if (error == ERESTART) 1627 error = EINTR; 1628 else if (error == EWOULDBLOCK) 1629 error = 0; 1630 goto done; 1631 } 1632 1633 TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); 1634 influx = 0; 1635 while (count) { 1636 KQ_OWNED(kq); 1637 kn = TAILQ_FIRST(&kq->kq_head); 1638 1639 if ((kn->kn_status == KN_MARKER && kn != marker) || 1640 (kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1641 if (influx) { 1642 influx = 0; 1643 KQ_FLUX_WAKEUP(kq); 1644 } 1645 kq->kq_state |= KQ_FLUXWAIT; 1646 error = msleep(kq, &kq->kq_lock, PSOCK, 1647 "kqflxwt", 0); 1648 continue; 1649 } 1650 1651 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1652 if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) { 1653 kn->kn_status &= ~KN_QUEUED; 1654 kq->kq_count--; 1655 continue; 1656 } 1657 if (kn == marker) { 1658 KQ_FLUX_WAKEUP(kq); 1659 if (count == maxevents) 1660 goto retry; 1661 goto done; 1662 } 1663 KASSERT((kn->kn_status & KN_INFLUX) == 0, 1664 ("KN_INFLUX set when not suppose to be")); 1665 1666 if ((kn->kn_flags & EV_DROP) == EV_DROP) { 1667 kn->kn_status &= ~KN_QUEUED; 1668 kn->kn_status |= KN_INFLUX; 1669 kq->kq_count--; 1670 KQ_UNLOCK(kq); 1671 /* 1672 * We don't need to lock the list since we've marked 1673 * it _INFLUX. 1674 */ 1675 if (!(kn->kn_status & KN_DETACHED)) 1676 kn->kn_fop->f_detach(kn); 1677 knote_drop(kn, td); 1678 KQ_LOCK(kq); 1679 continue; 1680 } else if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) { 1681 kn->kn_status &= ~KN_QUEUED; 1682 kn->kn_status |= KN_INFLUX; 1683 kq->kq_count--; 1684 KQ_UNLOCK(kq); 1685 /* 1686 * We don't need to lock the list since we've marked 1687 * it _INFLUX. 1688 */ 1689 *kevp = kn->kn_kevent; 1690 if (!(kn->kn_status & KN_DETACHED)) 1691 kn->kn_fop->f_detach(kn); 1692 knote_drop(kn, td); 1693 KQ_LOCK(kq); 1694 kn = NULL; 1695 } else { 1696 kn->kn_status |= KN_INFLUX | KN_SCAN; 1697 KQ_UNLOCK(kq); 1698 if ((kn->kn_status & KN_KQUEUE) == KN_KQUEUE) 1699 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1700 knl = kn_list_lock(kn); 1701 if (kn->kn_fop->f_event(kn, 0) == 0) { 1702 KQ_LOCK(kq); 1703 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1704 kn->kn_status &= 1705 ~(KN_QUEUED | KN_ACTIVE | KN_INFLUX | 1706 KN_SCAN); 1707 kq->kq_count--; 1708 kn_list_unlock(knl); 1709 influx = 1; 1710 continue; 1711 } 1712 touch = (!kn->kn_fop->f_isfd && 1713 kn->kn_fop->f_touch != NULL); 1714 if (touch) 1715 kn->kn_fop->f_touch(kn, kevp, EVENT_PROCESS); 1716 else 1717 *kevp = kn->kn_kevent; 1718 KQ_LOCK(kq); 1719 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1720 if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) { 1721 /* 1722 * Manually clear knotes who weren't 1723 * 'touch'ed. 1724 */ 1725 if (touch == 0 && kn->kn_flags & EV_CLEAR) { 1726 kn->kn_data = 0; 1727 kn->kn_fflags = 0; 1728 } 1729 if (kn->kn_flags & EV_DISPATCH) 1730 kn->kn_status |= KN_DISABLED; 1731 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 1732 kq->kq_count--; 1733 } else 1734 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 1735 1736 kn->kn_status &= ~(KN_INFLUX | KN_SCAN); 1737 kn_list_unlock(knl); 1738 influx = 1; 1739 } 1740 1741 /* we are returning a copy to the user */ 1742 kevp++; 1743 nkev++; 1744 count--; 1745 1746 if (nkev == KQ_NEVENTS) { 1747 influx = 0; 1748 KQ_UNLOCK_FLUX(kq); 1749 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1750 nkev = 0; 1751 kevp = keva; 1752 KQ_LOCK(kq); 1753 if (error) 1754 break; 1755 } 1756 } 1757 TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); 1758 done: 1759 KQ_OWNED(kq); 1760 KQ_UNLOCK_FLUX(kq); 1761 knote_free(marker); 1762 done_nl: 1763 KQ_NOTOWNED(kq); 1764 if (nkev != 0) 1765 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1766 td->td_retval[0] = maxevents - count; 1767 return (error); 1768 } 1769 1770 /*ARGSUSED*/ 1771 static int 1772 kqueue_ioctl(struct file *fp, u_long cmd, void *data, 1773 struct ucred *active_cred, struct thread *td) 1774 { 1775 /* 1776 * Enabling sigio causes two major problems: 1777 * 1) infinite recursion: 1778 * Synopsys: kevent is being used to track signals and have FIOASYNC 1779 * set. On receipt of a signal this will cause a kqueue to recurse 1780 * into itself over and over. Sending the sigio causes the kqueue 1781 * to become ready, which in turn posts sigio again, forever. 1782 * Solution: this can be solved by setting a flag in the kqueue that 1783 * we have a SIGIO in progress. 1784 * 2) locking problems: 1785 * Synopsys: Kqueue is a leaf subsystem, but adding signalling puts 1786 * us above the proc and pgrp locks. 1787 * Solution: Post a signal using an async mechanism, being sure to 1788 * record a generation count in the delivery so that we do not deliver 1789 * a signal to the wrong process. 1790 * 1791 * Note, these two mechanisms are somewhat mutually exclusive! 1792 */ 1793 #if 0 1794 struct kqueue *kq; 1795 1796 kq = fp->f_data; 1797 switch (cmd) { 1798 case FIOASYNC: 1799 if (*(int *)data) { 1800 kq->kq_state |= KQ_ASYNC; 1801 } else { 1802 kq->kq_state &= ~KQ_ASYNC; 1803 } 1804 return (0); 1805 1806 case FIOSETOWN: 1807 return (fsetown(*(int *)data, &kq->kq_sigio)); 1808 1809 case FIOGETOWN: 1810 *(int *)data = fgetown(&kq->kq_sigio); 1811 return (0); 1812 } 1813 #endif 1814 1815 return (ENOTTY); 1816 } 1817 1818 /*ARGSUSED*/ 1819 static int 1820 kqueue_poll(struct file *fp, int events, struct ucred *active_cred, 1821 struct thread *td) 1822 { 1823 struct kqueue *kq; 1824 int revents = 0; 1825 int error; 1826 1827 if ((error = kqueue_acquire(fp, &kq))) 1828 return POLLERR; 1829 1830 KQ_LOCK(kq); 1831 if (events & (POLLIN | POLLRDNORM)) { 1832 if (kq->kq_count) { 1833 revents |= events & (POLLIN | POLLRDNORM); 1834 } else { 1835 selrecord(td, &kq->kq_sel); 1836 if (SEL_WAITING(&kq->kq_sel)) 1837 kq->kq_state |= KQ_SEL; 1838 } 1839 } 1840 kqueue_release(kq, 1); 1841 KQ_UNLOCK(kq); 1842 return (revents); 1843 } 1844 1845 /*ARGSUSED*/ 1846 static int 1847 kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred, 1848 struct thread *td) 1849 { 1850 1851 bzero((void *)st, sizeof *st); 1852 /* 1853 * We no longer return kq_count because the unlocked value is useless. 1854 * If you spent all this time getting the count, why not spend your 1855 * syscall better by calling kevent? 1856 * 1857 * XXX - This is needed for libc_r. 1858 */ 1859 st->st_mode = S_IFIFO; 1860 return (0); 1861 } 1862 1863 static void 1864 kqueue_drain(struct kqueue *kq, struct thread *td) 1865 { 1866 struct knote *kn; 1867 int i; 1868 1869 KQ_LOCK(kq); 1870 1871 KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING, 1872 ("kqueue already closing")); 1873 kq->kq_state |= KQ_CLOSING; 1874 if (kq->kq_refcnt > 1) 1875 msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0); 1876 1877 KASSERT(kq->kq_refcnt == 1, ("other refs are out there!")); 1878 1879 KASSERT(knlist_empty(&kq->kq_sel.si_note), 1880 ("kqueue's knlist not empty")); 1881 1882 for (i = 0; i < kq->kq_knlistsize; i++) { 1883 while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) { 1884 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1885 kq->kq_state |= KQ_FLUXWAIT; 1886 msleep(kq, &kq->kq_lock, PSOCK, "kqclo1", 0); 1887 continue; 1888 } 1889 kn->kn_status |= KN_INFLUX; 1890 KQ_UNLOCK(kq); 1891 if (!(kn->kn_status & KN_DETACHED)) 1892 kn->kn_fop->f_detach(kn); 1893 knote_drop(kn, td); 1894 KQ_LOCK(kq); 1895 } 1896 } 1897 if (kq->kq_knhashmask != 0) { 1898 for (i = 0; i <= kq->kq_knhashmask; i++) { 1899 while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) { 1900 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1901 kq->kq_state |= KQ_FLUXWAIT; 1902 msleep(kq, &kq->kq_lock, PSOCK, 1903 "kqclo2", 0); 1904 continue; 1905 } 1906 kn->kn_status |= KN_INFLUX; 1907 KQ_UNLOCK(kq); 1908 if (!(kn->kn_status & KN_DETACHED)) 1909 kn->kn_fop->f_detach(kn); 1910 knote_drop(kn, td); 1911 KQ_LOCK(kq); 1912 } 1913 } 1914 } 1915 1916 if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) { 1917 kq->kq_state |= KQ_TASKDRAIN; 1918 msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0); 1919 } 1920 1921 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 1922 selwakeuppri(&kq->kq_sel, PSOCK); 1923 if (!SEL_WAITING(&kq->kq_sel)) 1924 kq->kq_state &= ~KQ_SEL; 1925 } 1926 1927 KQ_UNLOCK(kq); 1928 } 1929 1930 static void 1931 kqueue_destroy(struct kqueue *kq) 1932 { 1933 1934 KASSERT(kq->kq_fdp == NULL, 1935 ("kqueue still attached to a file descriptor")); 1936 seldrain(&kq->kq_sel); 1937 knlist_destroy(&kq->kq_sel.si_note); 1938 mtx_destroy(&kq->kq_lock); 1939 1940 if (kq->kq_knhash != NULL) 1941 free(kq->kq_knhash, M_KQUEUE); 1942 if (kq->kq_knlist != NULL) 1943 free(kq->kq_knlist, M_KQUEUE); 1944 1945 funsetown(&kq->kq_sigio); 1946 } 1947 1948 /*ARGSUSED*/ 1949 static int 1950 kqueue_close(struct file *fp, struct thread *td) 1951 { 1952 struct kqueue *kq = fp->f_data; 1953 struct filedesc *fdp; 1954 int error; 1955 int filedesc_unlock; 1956 1957 if ((error = kqueue_acquire(fp, &kq))) 1958 return error; 1959 kqueue_drain(kq, td); 1960 1961 /* 1962 * We could be called due to the knote_drop() doing fdrop(), 1963 * called from kqueue_register(). In this case the global 1964 * lock is owned, and filedesc sx is locked before, to not 1965 * take the sleepable lock after non-sleepable. 1966 */ 1967 fdp = kq->kq_fdp; 1968 kq->kq_fdp = NULL; 1969 if (!sx_xlocked(FILEDESC_LOCK(fdp))) { 1970 FILEDESC_XLOCK(fdp); 1971 filedesc_unlock = 1; 1972 } else 1973 filedesc_unlock = 0; 1974 TAILQ_REMOVE(&fdp->fd_kqlist, kq, kq_list); 1975 if (filedesc_unlock) 1976 FILEDESC_XUNLOCK(fdp); 1977 1978 kqueue_destroy(kq); 1979 chgkqcnt(kq->kq_cred->cr_ruidinfo, -1, 0); 1980 crfree(kq->kq_cred); 1981 free(kq, M_KQUEUE); 1982 fp->f_data = NULL; 1983 1984 return (0); 1985 } 1986 1987 static int 1988 kqueue_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 1989 { 1990 1991 kif->kf_type = KF_TYPE_KQUEUE; 1992 return (0); 1993 } 1994 1995 static void 1996 kqueue_wakeup(struct kqueue *kq) 1997 { 1998 KQ_OWNED(kq); 1999 2000 if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) { 2001 kq->kq_state &= ~KQ_SLEEP; 2002 wakeup(kq); 2003 } 2004 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2005 selwakeuppri(&kq->kq_sel, PSOCK); 2006 if (!SEL_WAITING(&kq->kq_sel)) 2007 kq->kq_state &= ~KQ_SEL; 2008 } 2009 if (!knlist_empty(&kq->kq_sel.si_note)) 2010 kqueue_schedtask(kq); 2011 if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) { 2012 pgsigio(&kq->kq_sigio, SIGIO, 0); 2013 } 2014 } 2015 2016 /* 2017 * Walk down a list of knotes, activating them if their event has triggered. 2018 * 2019 * There is a possibility to optimize in the case of one kq watching another. 2020 * Instead of scheduling a task to wake it up, you could pass enough state 2021 * down the chain to make up the parent kqueue. Make this code functional 2022 * first. 2023 */ 2024 void 2025 knote(struct knlist *list, long hint, int lockflags) 2026 { 2027 struct kqueue *kq; 2028 struct knote *kn, *tkn; 2029 int error; 2030 bool own_influx; 2031 2032 if (list == NULL) 2033 return; 2034 2035 KNL_ASSERT_LOCK(list, lockflags & KNF_LISTLOCKED); 2036 2037 if ((lockflags & KNF_LISTLOCKED) == 0) 2038 list->kl_lock(list->kl_lockarg); 2039 2040 /* 2041 * If we unlock the list lock (and set KN_INFLUX), we can 2042 * eliminate the kqueue scheduling, but this will introduce 2043 * four lock/unlock's for each knote to test. Also, marker 2044 * would be needed to keep iteration position, since filters 2045 * or other threads could remove events. 2046 */ 2047 SLIST_FOREACH_SAFE(kn, &list->kl_list, kn_selnext, tkn) { 2048 kq = kn->kn_kq; 2049 KQ_LOCK(kq); 2050 if ((kn->kn_status & (KN_INFLUX | KN_SCAN)) == KN_INFLUX) { 2051 /* 2052 * Do not process the influx notes, except for 2053 * the influx coming from the kq unlock in the 2054 * kqueue_scan(). In the later case, we do 2055 * not interfere with the scan, since the code 2056 * fragment in kqueue_scan() locks the knlist, 2057 * and cannot proceed until we finished. 2058 */ 2059 KQ_UNLOCK(kq); 2060 } else if ((lockflags & KNF_NOKQLOCK) != 0) { 2061 own_influx = (kn->kn_status & KN_INFLUX) == 0; 2062 if (own_influx) 2063 kn->kn_status |= KN_INFLUX; 2064 KQ_UNLOCK(kq); 2065 error = kn->kn_fop->f_event(kn, hint); 2066 KQ_LOCK(kq); 2067 if (own_influx) 2068 kn->kn_status &= ~KN_INFLUX; 2069 if (error) 2070 KNOTE_ACTIVATE(kn, 1); 2071 KQ_UNLOCK_FLUX(kq); 2072 } else { 2073 kn->kn_status |= KN_HASKQLOCK; 2074 if (kn->kn_fop->f_event(kn, hint)) 2075 KNOTE_ACTIVATE(kn, 1); 2076 kn->kn_status &= ~KN_HASKQLOCK; 2077 KQ_UNLOCK(kq); 2078 } 2079 } 2080 if ((lockflags & KNF_LISTLOCKED) == 0) 2081 list->kl_unlock(list->kl_lockarg); 2082 } 2083 2084 /* 2085 * add a knote to a knlist 2086 */ 2087 void 2088 knlist_add(struct knlist *knl, struct knote *kn, int islocked) 2089 { 2090 KNL_ASSERT_LOCK(knl, islocked); 2091 KQ_NOTOWNED(kn->kn_kq); 2092 KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) == 2093 (KN_INFLUX|KN_DETACHED), ("knote not KN_INFLUX and KN_DETACHED")); 2094 if (!islocked) 2095 knl->kl_lock(knl->kl_lockarg); 2096 SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext); 2097 if (!islocked) 2098 knl->kl_unlock(knl->kl_lockarg); 2099 KQ_LOCK(kn->kn_kq); 2100 kn->kn_knlist = knl; 2101 kn->kn_status &= ~KN_DETACHED; 2102 KQ_UNLOCK(kn->kn_kq); 2103 } 2104 2105 static void 2106 knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked, 2107 int kqislocked) 2108 { 2109 KASSERT(!(!!kqislocked && !knlislocked), ("kq locked w/o knl locked")); 2110 KNL_ASSERT_LOCK(knl, knlislocked); 2111 mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED); 2112 if (!kqislocked) 2113 KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) == KN_INFLUX, 2114 ("knlist_remove called w/o knote being KN_INFLUX or already removed")); 2115 if (!knlislocked) 2116 knl->kl_lock(knl->kl_lockarg); 2117 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext); 2118 kn->kn_knlist = NULL; 2119 if (!knlislocked) 2120 kn_list_unlock(knl); 2121 if (!kqislocked) 2122 KQ_LOCK(kn->kn_kq); 2123 kn->kn_status |= KN_DETACHED; 2124 if (!kqislocked) 2125 KQ_UNLOCK(kn->kn_kq); 2126 } 2127 2128 /* 2129 * remove knote from the specified knlist 2130 */ 2131 void 2132 knlist_remove(struct knlist *knl, struct knote *kn, int islocked) 2133 { 2134 2135 knlist_remove_kq(knl, kn, islocked, 0); 2136 } 2137 2138 int 2139 knlist_empty(struct knlist *knl) 2140 { 2141 2142 KNL_ASSERT_LOCKED(knl); 2143 return (SLIST_EMPTY(&knl->kl_list)); 2144 } 2145 2146 static struct mtx knlist_lock; 2147 MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects", 2148 MTX_DEF); 2149 static void knlist_mtx_lock(void *arg); 2150 static void knlist_mtx_unlock(void *arg); 2151 2152 static void 2153 knlist_mtx_lock(void *arg) 2154 { 2155 2156 mtx_lock((struct mtx *)arg); 2157 } 2158 2159 static void 2160 knlist_mtx_unlock(void *arg) 2161 { 2162 2163 mtx_unlock((struct mtx *)arg); 2164 } 2165 2166 static void 2167 knlist_mtx_assert_locked(void *arg) 2168 { 2169 2170 mtx_assert((struct mtx *)arg, MA_OWNED); 2171 } 2172 2173 static void 2174 knlist_mtx_assert_unlocked(void *arg) 2175 { 2176 2177 mtx_assert((struct mtx *)arg, MA_NOTOWNED); 2178 } 2179 2180 static void 2181 knlist_rw_rlock(void *arg) 2182 { 2183 2184 rw_rlock((struct rwlock *)arg); 2185 } 2186 2187 static void 2188 knlist_rw_runlock(void *arg) 2189 { 2190 2191 rw_runlock((struct rwlock *)arg); 2192 } 2193 2194 static void 2195 knlist_rw_assert_locked(void *arg) 2196 { 2197 2198 rw_assert((struct rwlock *)arg, RA_LOCKED); 2199 } 2200 2201 static void 2202 knlist_rw_assert_unlocked(void *arg) 2203 { 2204 2205 rw_assert((struct rwlock *)arg, RA_UNLOCKED); 2206 } 2207 2208 void 2209 knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *), 2210 void (*kl_unlock)(void *), 2211 void (*kl_assert_locked)(void *), void (*kl_assert_unlocked)(void *)) 2212 { 2213 2214 if (lock == NULL) 2215 knl->kl_lockarg = &knlist_lock; 2216 else 2217 knl->kl_lockarg = lock; 2218 2219 if (kl_lock == NULL) 2220 knl->kl_lock = knlist_mtx_lock; 2221 else 2222 knl->kl_lock = kl_lock; 2223 if (kl_unlock == NULL) 2224 knl->kl_unlock = knlist_mtx_unlock; 2225 else 2226 knl->kl_unlock = kl_unlock; 2227 if (kl_assert_locked == NULL) 2228 knl->kl_assert_locked = knlist_mtx_assert_locked; 2229 else 2230 knl->kl_assert_locked = kl_assert_locked; 2231 if (kl_assert_unlocked == NULL) 2232 knl->kl_assert_unlocked = knlist_mtx_assert_unlocked; 2233 else 2234 knl->kl_assert_unlocked = kl_assert_unlocked; 2235 2236 knl->kl_autodestroy = 0; 2237 SLIST_INIT(&knl->kl_list); 2238 } 2239 2240 void 2241 knlist_init_mtx(struct knlist *knl, struct mtx *lock) 2242 { 2243 2244 knlist_init(knl, lock, NULL, NULL, NULL, NULL); 2245 } 2246 2247 struct knlist * 2248 knlist_alloc(struct mtx *lock) 2249 { 2250 struct knlist *knl; 2251 2252 knl = malloc(sizeof(struct knlist), M_KQUEUE, M_WAITOK); 2253 knlist_init_mtx(knl, lock); 2254 return (knl); 2255 } 2256 2257 void 2258 knlist_init_rw_reader(struct knlist *knl, struct rwlock *lock) 2259 { 2260 2261 knlist_init(knl, lock, knlist_rw_rlock, knlist_rw_runlock, 2262 knlist_rw_assert_locked, knlist_rw_assert_unlocked); 2263 } 2264 2265 void 2266 knlist_destroy(struct knlist *knl) 2267 { 2268 2269 KASSERT(KNLIST_EMPTY(knl), 2270 ("destroying knlist %p with knotes on it", knl)); 2271 } 2272 2273 void 2274 knlist_detach(struct knlist *knl) 2275 { 2276 2277 KNL_ASSERT_LOCKED(knl); 2278 knl->kl_autodestroy = 1; 2279 if (knlist_empty(knl)) { 2280 knlist_destroy(knl); 2281 free(knl, M_KQUEUE); 2282 } 2283 } 2284 2285 /* 2286 * Even if we are locked, we may need to drop the lock to allow any influx 2287 * knotes time to "settle". 2288 */ 2289 void 2290 knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn) 2291 { 2292 struct knote *kn, *kn2; 2293 struct kqueue *kq; 2294 2295 KASSERT(!knl->kl_autodestroy, ("cleardel for autodestroy %p", knl)); 2296 if (islocked) 2297 KNL_ASSERT_LOCKED(knl); 2298 else { 2299 KNL_ASSERT_UNLOCKED(knl); 2300 again: /* need to reacquire lock since we have dropped it */ 2301 knl->kl_lock(knl->kl_lockarg); 2302 } 2303 2304 SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) { 2305 kq = kn->kn_kq; 2306 KQ_LOCK(kq); 2307 if ((kn->kn_status & KN_INFLUX)) { 2308 KQ_UNLOCK(kq); 2309 continue; 2310 } 2311 knlist_remove_kq(knl, kn, 1, 1); 2312 if (killkn) { 2313 kn->kn_status |= KN_INFLUX | KN_DETACHED; 2314 KQ_UNLOCK(kq); 2315 knote_drop(kn, td); 2316 } else { 2317 /* Make sure cleared knotes disappear soon */ 2318 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 2319 KQ_UNLOCK(kq); 2320 } 2321 kq = NULL; 2322 } 2323 2324 if (!SLIST_EMPTY(&knl->kl_list)) { 2325 /* there are still KN_INFLUX remaining */ 2326 kn = SLIST_FIRST(&knl->kl_list); 2327 kq = kn->kn_kq; 2328 KQ_LOCK(kq); 2329 KASSERT(kn->kn_status & KN_INFLUX, 2330 ("knote removed w/o list lock")); 2331 knl->kl_unlock(knl->kl_lockarg); 2332 kq->kq_state |= KQ_FLUXWAIT; 2333 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0); 2334 kq = NULL; 2335 goto again; 2336 } 2337 2338 if (islocked) 2339 KNL_ASSERT_LOCKED(knl); 2340 else { 2341 knl->kl_unlock(knl->kl_lockarg); 2342 KNL_ASSERT_UNLOCKED(knl); 2343 } 2344 } 2345 2346 /* 2347 * Remove all knotes referencing a specified fd must be called with FILEDESC 2348 * lock. This prevents a race where a new fd comes along and occupies the 2349 * entry and we attach a knote to the fd. 2350 */ 2351 void 2352 knote_fdclose(struct thread *td, int fd) 2353 { 2354 struct filedesc *fdp = td->td_proc->p_fd; 2355 struct kqueue *kq; 2356 struct knote *kn; 2357 int influx; 2358 2359 FILEDESC_XLOCK_ASSERT(fdp); 2360 2361 /* 2362 * We shouldn't have to worry about new kevents appearing on fd 2363 * since filedesc is locked. 2364 */ 2365 TAILQ_FOREACH(kq, &fdp->fd_kqlist, kq_list) { 2366 KQ_LOCK(kq); 2367 2368 again: 2369 influx = 0; 2370 while (kq->kq_knlistsize > fd && 2371 (kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) { 2372 if (kn->kn_status & KN_INFLUX) { 2373 /* someone else might be waiting on our knote */ 2374 if (influx) 2375 wakeup(kq); 2376 kq->kq_state |= KQ_FLUXWAIT; 2377 msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0); 2378 goto again; 2379 } 2380 kn->kn_status |= KN_INFLUX; 2381 KQ_UNLOCK(kq); 2382 if (!(kn->kn_status & KN_DETACHED)) 2383 kn->kn_fop->f_detach(kn); 2384 knote_drop(kn, td); 2385 influx = 1; 2386 KQ_LOCK(kq); 2387 } 2388 KQ_UNLOCK_FLUX(kq); 2389 } 2390 } 2391 2392 static int 2393 knote_attach(struct knote *kn, struct kqueue *kq) 2394 { 2395 struct klist *list; 2396 2397 KASSERT(kn->kn_status & KN_INFLUX, ("knote not marked INFLUX")); 2398 KQ_OWNED(kq); 2399 2400 if (kn->kn_fop->f_isfd) { 2401 if (kn->kn_id >= kq->kq_knlistsize) 2402 return (ENOMEM); 2403 list = &kq->kq_knlist[kn->kn_id]; 2404 } else { 2405 if (kq->kq_knhash == NULL) 2406 return (ENOMEM); 2407 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2408 } 2409 SLIST_INSERT_HEAD(list, kn, kn_link); 2410 return (0); 2411 } 2412 2413 /* 2414 * knote must already have been detached using the f_detach method. 2415 * no lock need to be held, it is assumed that the KN_INFLUX flag is set 2416 * to prevent other removal. 2417 */ 2418 static void 2419 knote_drop(struct knote *kn, struct thread *td) 2420 { 2421 struct kqueue *kq; 2422 struct klist *list; 2423 2424 kq = kn->kn_kq; 2425 2426 KQ_NOTOWNED(kq); 2427 KASSERT((kn->kn_status & KN_INFLUX) == KN_INFLUX, 2428 ("knote_drop called without KN_INFLUX set in kn_status")); 2429 2430 KQ_LOCK(kq); 2431 if (kn->kn_fop->f_isfd) 2432 list = &kq->kq_knlist[kn->kn_id]; 2433 else 2434 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2435 2436 if (!SLIST_EMPTY(list)) 2437 SLIST_REMOVE(list, kn, knote, kn_link); 2438 if (kn->kn_status & KN_QUEUED) 2439 knote_dequeue(kn); 2440 KQ_UNLOCK_FLUX(kq); 2441 2442 if (kn->kn_fop->f_isfd) { 2443 fdrop(kn->kn_fp, td); 2444 kn->kn_fp = NULL; 2445 } 2446 kqueue_fo_release(kn->kn_kevent.filter); 2447 kn->kn_fop = NULL; 2448 knote_free(kn); 2449 } 2450 2451 static void 2452 knote_enqueue(struct knote *kn) 2453 { 2454 struct kqueue *kq = kn->kn_kq; 2455 2456 KQ_OWNED(kn->kn_kq); 2457 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 2458 2459 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2460 kn->kn_status |= KN_QUEUED; 2461 kq->kq_count++; 2462 kqueue_wakeup(kq); 2463 } 2464 2465 static void 2466 knote_dequeue(struct knote *kn) 2467 { 2468 struct kqueue *kq = kn->kn_kq; 2469 2470 KQ_OWNED(kn->kn_kq); 2471 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 2472 2473 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 2474 kn->kn_status &= ~KN_QUEUED; 2475 kq->kq_count--; 2476 } 2477 2478 static void 2479 knote_init(void) 2480 { 2481 2482 knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL, 2483 NULL, NULL, UMA_ALIGN_PTR, 0); 2484 } 2485 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL); 2486 2487 static struct knote * 2488 knote_alloc(int waitok) 2489 { 2490 2491 return (uma_zalloc(knote_zone, (waitok ? M_WAITOK : M_NOWAIT) | 2492 M_ZERO)); 2493 } 2494 2495 static void 2496 knote_free(struct knote *kn) 2497 { 2498 2499 uma_zfree(knote_zone, kn); 2500 } 2501 2502 /* 2503 * Register the kev w/ the kq specified by fd. 2504 */ 2505 int 2506 kqfd_register(int fd, struct kevent *kev, struct thread *td, int waitok) 2507 { 2508 struct kqueue *kq; 2509 struct file *fp; 2510 cap_rights_t rights; 2511 int error; 2512 2513 error = fget(td, fd, cap_rights_init(&rights, CAP_KQUEUE_CHANGE), &fp); 2514 if (error != 0) 2515 return (error); 2516 if ((error = kqueue_acquire(fp, &kq)) != 0) 2517 goto noacquire; 2518 2519 error = kqueue_register(kq, kev, td, waitok); 2520 kqueue_release(kq, 0); 2521 2522 noacquire: 2523 fdrop(fp, td); 2524 return (error); 2525 }
Cache object: a044f53490a28a794bd8c1c114850870
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]