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("$FreeBSD$"); 31 32 #include "opt_ktrace.h" 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/capability.h> 37 #include <sys/kernel.h> 38 #include <sys/lock.h> 39 #include <sys/mutex.h> 40 #include <sys/rwlock.h> 41 #include <sys/proc.h> 42 #include <sys/malloc.h> 43 #include <sys/unistd.h> 44 #include <sys/file.h> 45 #include <sys/filedesc.h> 46 #include <sys/filio.h> 47 #include <sys/fcntl.h> 48 #include <sys/kthread.h> 49 #include <sys/selinfo.h> 50 #include <sys/stdatomic.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/sigio.h> 57 #include <sys/signalvar.h> 58 #include <sys/socket.h> 59 #include <sys/socketvar.h> 60 #include <sys/stat.h> 61 #include <sys/sysctl.h> 62 #include <sys/sysproto.h> 63 #include <sys/syscallsubr.h> 64 #include <sys/taskqueue.h> 65 #include <sys/uio.h> 66 #ifdef KTRACE 67 #include <sys/ktrace.h> 68 #endif 69 70 #include <vm/uma.h> 71 72 static MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system"); 73 74 /* 75 * This lock is used if multiple kq locks are required. This possibly 76 * should be made into a per proc lock. 77 */ 78 static struct mtx kq_global; 79 MTX_SYSINIT(kq_global, &kq_global, "kqueue order", MTX_DEF); 80 #define KQ_GLOBAL_LOCK(lck, haslck) do { \ 81 if (!haslck) \ 82 mtx_lock(lck); \ 83 haslck = 1; \ 84 } while (0) 85 #define KQ_GLOBAL_UNLOCK(lck, haslck) do { \ 86 if (haslck) \ 87 mtx_unlock(lck); \ 88 haslck = 0; \ 89 } while (0) 90 91 TASKQUEUE_DEFINE_THREAD(kqueue); 92 93 static int kevent_copyout(void *arg, struct kevent *kevp, int count); 94 static int kevent_copyin(void *arg, struct kevent *kevp, int count); 95 static int kqueue_register(struct kqueue *kq, struct kevent *kev, 96 struct thread *td, int waitok); 97 static int kqueue_acquire(struct file *fp, struct kqueue **kqp); 98 static void kqueue_release(struct kqueue *kq, int locked); 99 static int kqueue_expand(struct kqueue *kq, struct filterops *fops, 100 uintptr_t ident, int waitok); 101 static void kqueue_task(void *arg, int pending); 102 static int kqueue_scan(struct kqueue *kq, int maxevents, 103 struct kevent_copyops *k_ops, 104 const struct timespec *timeout, 105 struct kevent *keva, struct thread *td); 106 static void kqueue_wakeup(struct kqueue *kq); 107 static struct filterops *kqueue_fo_find(int filt); 108 static void kqueue_fo_release(int filt); 109 110 static fo_rdwr_t kqueue_read; 111 static fo_rdwr_t kqueue_write; 112 static fo_truncate_t kqueue_truncate; 113 static fo_ioctl_t kqueue_ioctl; 114 static fo_poll_t kqueue_poll; 115 static fo_kqfilter_t kqueue_kqfilter; 116 static fo_stat_t kqueue_stat; 117 static fo_close_t kqueue_close; 118 119 static struct fileops kqueueops = { 120 .fo_read = kqueue_read, 121 .fo_write = kqueue_write, 122 .fo_truncate = kqueue_truncate, 123 .fo_ioctl = kqueue_ioctl, 124 .fo_poll = kqueue_poll, 125 .fo_kqfilter = kqueue_kqfilter, 126 .fo_stat = kqueue_stat, 127 .fo_close = kqueue_close, 128 .fo_chmod = invfo_chmod, 129 .fo_chown = invfo_chown, 130 }; 131 132 static int knote_attach(struct knote *kn, struct kqueue *kq); 133 static void knote_drop(struct knote *kn, struct thread *td); 134 static void knote_enqueue(struct knote *kn); 135 static void knote_dequeue(struct knote *kn); 136 static void knote_init(void); 137 static struct knote *knote_alloc(int waitok); 138 static void knote_free(struct knote *kn); 139 140 static void filt_kqdetach(struct knote *kn); 141 static int filt_kqueue(struct knote *kn, long hint); 142 static int filt_procattach(struct knote *kn); 143 static void filt_procdetach(struct knote *kn); 144 static int filt_proc(struct knote *kn, long hint); 145 static int filt_fileattach(struct knote *kn); 146 static void filt_timerexpire(void *knx); 147 static int filt_timerattach(struct knote *kn); 148 static void filt_timerdetach(struct knote *kn); 149 static int filt_timer(struct knote *kn, long hint); 150 static int filt_userattach(struct knote *kn); 151 static void filt_userdetach(struct knote *kn); 152 static int filt_user(struct knote *kn, long hint); 153 static void filt_usertouch(struct knote *kn, struct kevent *kev, 154 u_long type); 155 156 static struct filterops file_filtops = { 157 .f_isfd = 1, 158 .f_attach = filt_fileattach, 159 }; 160 static struct filterops kqread_filtops = { 161 .f_isfd = 1, 162 .f_detach = filt_kqdetach, 163 .f_event = filt_kqueue, 164 }; 165 /* XXX - move to kern_proc.c? */ 166 static struct filterops proc_filtops = { 167 .f_isfd = 0, 168 .f_attach = filt_procattach, 169 .f_detach = filt_procdetach, 170 .f_event = filt_proc, 171 }; 172 static struct filterops timer_filtops = { 173 .f_isfd = 0, 174 .f_attach = filt_timerattach, 175 .f_detach = filt_timerdetach, 176 .f_event = filt_timer, 177 }; 178 static struct filterops user_filtops = { 179 .f_attach = filt_userattach, 180 .f_detach = filt_userdetach, 181 .f_event = filt_user, 182 .f_touch = filt_usertouch, 183 }; 184 185 static uma_zone_t knote_zone; 186 static atomic_uint kq_ncallouts = ATOMIC_VAR_INIT(0); 187 static unsigned int kq_calloutmax = 4 * 1024; 188 SYSCTL_UINT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW, 189 &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue"); 190 191 /* XXX - ensure not KN_INFLUX?? */ 192 #define KNOTE_ACTIVATE(kn, islock) do { \ 193 if ((islock)) \ 194 mtx_assert(&(kn)->kn_kq->kq_lock, MA_OWNED); \ 195 else \ 196 KQ_LOCK((kn)->kn_kq); \ 197 (kn)->kn_status |= KN_ACTIVE; \ 198 if (((kn)->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 199 knote_enqueue((kn)); \ 200 if (!(islock)) \ 201 KQ_UNLOCK((kn)->kn_kq); \ 202 } while(0) 203 #define KQ_LOCK(kq) do { \ 204 mtx_lock(&(kq)->kq_lock); \ 205 } while (0) 206 #define KQ_FLUX_WAKEUP(kq) do { \ 207 if (((kq)->kq_state & KQ_FLUXWAIT) == KQ_FLUXWAIT) { \ 208 (kq)->kq_state &= ~KQ_FLUXWAIT; \ 209 wakeup((kq)); \ 210 } \ 211 } while (0) 212 #define KQ_UNLOCK_FLUX(kq) do { \ 213 KQ_FLUX_WAKEUP(kq); \ 214 mtx_unlock(&(kq)->kq_lock); \ 215 } while (0) 216 #define KQ_UNLOCK(kq) do { \ 217 mtx_unlock(&(kq)->kq_lock); \ 218 } while (0) 219 #define KQ_OWNED(kq) do { \ 220 mtx_assert(&(kq)->kq_lock, MA_OWNED); \ 221 } while (0) 222 #define KQ_NOTOWNED(kq) do { \ 223 mtx_assert(&(kq)->kq_lock, MA_NOTOWNED); \ 224 } while (0) 225 #define KN_LIST_LOCK(kn) do { \ 226 if (kn->kn_knlist != NULL) \ 227 kn->kn_knlist->kl_lock(kn->kn_knlist->kl_lockarg); \ 228 } while (0) 229 #define KN_LIST_UNLOCK(kn) do { \ 230 if (kn->kn_knlist != NULL) \ 231 kn->kn_knlist->kl_unlock(kn->kn_knlist->kl_lockarg); \ 232 } while (0) 233 #define KNL_ASSERT_LOCK(knl, islocked) do { \ 234 if (islocked) \ 235 KNL_ASSERT_LOCKED(knl); \ 236 else \ 237 KNL_ASSERT_UNLOCKED(knl); \ 238 } while (0) 239 #ifdef INVARIANTS 240 #define KNL_ASSERT_LOCKED(knl) do { \ 241 knl->kl_assert_locked((knl)->kl_lockarg); \ 242 } while (0) 243 #define KNL_ASSERT_UNLOCKED(knl) do { \ 244 knl->kl_assert_unlocked((knl)->kl_lockarg); \ 245 } while (0) 246 #else /* !INVARIANTS */ 247 #define KNL_ASSERT_LOCKED(knl) do {} while(0) 248 #define KNL_ASSERT_UNLOCKED(knl) do {} while (0) 249 #endif /* INVARIANTS */ 250 251 #define KN_HASHSIZE 64 /* XXX should be tunable */ 252 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 253 254 static int 255 filt_nullattach(struct knote *kn) 256 { 257 258 return (ENXIO); 259 }; 260 261 struct filterops null_filtops = { 262 .f_isfd = 0, 263 .f_attach = filt_nullattach, 264 }; 265 266 /* XXX - make SYSINIT to add these, and move into respective modules. */ 267 extern struct filterops sig_filtops; 268 extern struct filterops fs_filtops; 269 270 /* 271 * Table for for all system-defined filters. 272 */ 273 static struct mtx filterops_lock; 274 MTX_SYSINIT(kqueue_filterops, &filterops_lock, "protect sysfilt_ops", 275 MTX_DEF); 276 static struct { 277 struct filterops *for_fop; 278 int for_refcnt; 279 } sysfilt_ops[EVFILT_SYSCOUNT] = { 280 { &file_filtops }, /* EVFILT_READ */ 281 { &file_filtops }, /* EVFILT_WRITE */ 282 { &null_filtops }, /* EVFILT_AIO */ 283 { &file_filtops }, /* EVFILT_VNODE */ 284 { &proc_filtops }, /* EVFILT_PROC */ 285 { &sig_filtops }, /* EVFILT_SIGNAL */ 286 { &timer_filtops }, /* EVFILT_TIMER */ 287 { &null_filtops }, /* former EVFILT_NETDEV */ 288 { &fs_filtops }, /* EVFILT_FS */ 289 { &null_filtops }, /* EVFILT_LIO */ 290 { &user_filtops }, /* EVFILT_USER */ 291 }; 292 293 /* 294 * Simple redirection for all cdevsw style objects to call their fo_kqfilter 295 * method. 296 */ 297 static int 298 filt_fileattach(struct knote *kn) 299 { 300 301 return (fo_kqfilter(kn->kn_fp, kn)); 302 } 303 304 /*ARGSUSED*/ 305 static int 306 kqueue_kqfilter(struct file *fp, struct knote *kn) 307 { 308 struct kqueue *kq = kn->kn_fp->f_data; 309 310 if (kn->kn_filter != EVFILT_READ) 311 return (EINVAL); 312 313 kn->kn_status |= KN_KQUEUE; 314 kn->kn_fop = &kqread_filtops; 315 knlist_add(&kq->kq_sel.si_note, kn, 0); 316 317 return (0); 318 } 319 320 static void 321 filt_kqdetach(struct knote *kn) 322 { 323 struct kqueue *kq = kn->kn_fp->f_data; 324 325 knlist_remove(&kq->kq_sel.si_note, kn, 0); 326 } 327 328 /*ARGSUSED*/ 329 static int 330 filt_kqueue(struct knote *kn, long hint) 331 { 332 struct kqueue *kq = kn->kn_fp->f_data; 333 334 kn->kn_data = kq->kq_count; 335 return (kn->kn_data > 0); 336 } 337 338 /* XXX - move to kern_proc.c? */ 339 static int 340 filt_procattach(struct knote *kn) 341 { 342 struct proc *p; 343 int immediate; 344 int error; 345 346 immediate = 0; 347 p = pfind(kn->kn_id); 348 if (p == NULL && (kn->kn_sfflags & NOTE_EXIT)) { 349 p = zpfind(kn->kn_id); 350 immediate = 1; 351 } else if (p != NULL && (p->p_flag & P_WEXIT)) { 352 immediate = 1; 353 } 354 355 if (p == NULL) 356 return (ESRCH); 357 if ((error = p_cansee(curthread, p))) { 358 PROC_UNLOCK(p); 359 return (error); 360 } 361 362 kn->kn_ptr.p_proc = p; 363 kn->kn_flags |= EV_CLEAR; /* automatically set */ 364 365 /* 366 * internal flag indicating registration done by kernel 367 */ 368 if (kn->kn_flags & EV_FLAG1) { 369 kn->kn_data = kn->kn_sdata; /* ppid */ 370 kn->kn_fflags = NOTE_CHILD; 371 kn->kn_flags &= ~EV_FLAG1; 372 } 373 374 if (immediate == 0) 375 knlist_add(&p->p_klist, kn, 1); 376 377 /* 378 * Immediately activate any exit notes if the target process is a 379 * zombie. This is necessary to handle the case where the target 380 * process, e.g. a child, dies before the kevent is registered. 381 */ 382 if (immediate && filt_proc(kn, NOTE_EXIT)) 383 KNOTE_ACTIVATE(kn, 0); 384 385 PROC_UNLOCK(p); 386 387 return (0); 388 } 389 390 /* 391 * The knote may be attached to a different process, which may exit, 392 * leaving nothing for the knote to be attached to. So when the process 393 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 394 * it will be deleted when read out. However, as part of the knote deletion, 395 * this routine is called, so a check is needed to avoid actually performing 396 * a detach, because the original process does not exist any more. 397 */ 398 /* XXX - move to kern_proc.c? */ 399 static void 400 filt_procdetach(struct knote *kn) 401 { 402 struct proc *p; 403 404 p = kn->kn_ptr.p_proc; 405 knlist_remove(&p->p_klist, kn, 0); 406 kn->kn_ptr.p_proc = NULL; 407 } 408 409 /* XXX - move to kern_proc.c? */ 410 static int 411 filt_proc(struct knote *kn, long hint) 412 { 413 struct proc *p = kn->kn_ptr.p_proc; 414 u_int event; 415 416 /* 417 * mask off extra data 418 */ 419 event = (u_int)hint & NOTE_PCTRLMASK; 420 421 /* 422 * if the user is interested in this event, record it. 423 */ 424 if (kn->kn_sfflags & event) 425 kn->kn_fflags |= event; 426 427 /* 428 * process is gone, so flag the event as finished. 429 */ 430 if (event == NOTE_EXIT) { 431 if (!(kn->kn_status & KN_DETACHED)) 432 knlist_remove_inevent(&p->p_klist, kn); 433 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 434 kn->kn_ptr.p_proc = NULL; 435 if (kn->kn_fflags & NOTE_EXIT) 436 kn->kn_data = p->p_xstat; 437 if (kn->kn_fflags == 0) 438 kn->kn_flags |= EV_DROP; 439 return (1); 440 } 441 442 return (kn->kn_fflags != 0); 443 } 444 445 /* 446 * Called when the process forked. It mostly does the same as the 447 * knote(), activating all knotes registered to be activated when the 448 * process forked. Additionally, for each knote attached to the 449 * parent, check whether user wants to track the new process. If so 450 * attach a new knote to it, and immediately report an event with the 451 * child's pid. 452 */ 453 void 454 knote_fork(struct knlist *list, int pid) 455 { 456 struct kqueue *kq; 457 struct knote *kn; 458 struct kevent kev; 459 int error; 460 461 if (list == NULL) 462 return; 463 list->kl_lock(list->kl_lockarg); 464 465 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { 466 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) 467 continue; 468 kq = kn->kn_kq; 469 KQ_LOCK(kq); 470 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 471 KQ_UNLOCK(kq); 472 continue; 473 } 474 475 /* 476 * The same as knote(), activate the event. 477 */ 478 if ((kn->kn_sfflags & NOTE_TRACK) == 0) { 479 kn->kn_status |= KN_HASKQLOCK; 480 if (kn->kn_fop->f_event(kn, NOTE_FORK | pid)) 481 KNOTE_ACTIVATE(kn, 1); 482 kn->kn_status &= ~KN_HASKQLOCK; 483 KQ_UNLOCK(kq); 484 continue; 485 } 486 487 /* 488 * The NOTE_TRACK case. In addition to the activation 489 * of the event, we need to register new event to 490 * track the child. Drop the locks in preparation for 491 * the call to kqueue_register(). 492 */ 493 kn->kn_status |= KN_INFLUX; 494 KQ_UNLOCK(kq); 495 list->kl_unlock(list->kl_lockarg); 496 497 /* 498 * Activate existing knote and register a knote with 499 * new process. 500 */ 501 kev.ident = pid; 502 kev.filter = kn->kn_filter; 503 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 504 kev.fflags = kn->kn_sfflags; 505 kev.data = kn->kn_id; /* parent */ 506 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 507 error = kqueue_register(kq, &kev, NULL, 0); 508 if (kn->kn_fop->f_event(kn, NOTE_FORK | pid)) 509 KNOTE_ACTIVATE(kn, 0); 510 if (error) 511 kn->kn_fflags |= NOTE_TRACKERR; 512 KQ_LOCK(kq); 513 kn->kn_status &= ~KN_INFLUX; 514 KQ_UNLOCK_FLUX(kq); 515 list->kl_lock(list->kl_lockarg); 516 } 517 list->kl_unlock(list->kl_lockarg); 518 } 519 520 /* 521 * XXX: EVFILT_TIMER should perhaps live in kern_time.c beside the 522 * interval timer support code. 523 */ 524 static __inline sbintime_t 525 timer2sbintime(intptr_t data) 526 { 527 528 return (SBT_1MS * data); 529 } 530 531 static void 532 filt_timerexpire(void *knx) 533 { 534 struct callout *calloutp; 535 struct knote *kn; 536 537 kn = knx; 538 kn->kn_data++; 539 KNOTE_ACTIVATE(kn, 0); /* XXX - handle locking */ 540 541 if ((kn->kn_flags & EV_ONESHOT) != EV_ONESHOT) { 542 calloutp = (struct callout *)kn->kn_hook; 543 callout_reset_sbt_on(calloutp, 544 timer2sbintime(kn->kn_sdata), 0 /* 1ms? */, 545 filt_timerexpire, kn, PCPU_GET(cpuid), 0); 546 } 547 } 548 549 /* 550 * data contains amount of time to sleep, in milliseconds 551 */ 552 static int 553 filt_timerattach(struct knote *kn) 554 { 555 struct callout *calloutp; 556 unsigned int ncallouts; 557 558 ncallouts = atomic_load_explicit(&kq_ncallouts, memory_order_relaxed); 559 do { 560 if (ncallouts >= kq_calloutmax) 561 return (ENOMEM); 562 } while (!atomic_compare_exchange_weak_explicit(&kq_ncallouts, 563 &ncallouts, ncallouts + 1, memory_order_relaxed, 564 memory_order_relaxed)); 565 566 kn->kn_flags |= EV_CLEAR; /* automatically set */ 567 kn->kn_status &= ~KN_DETACHED; /* knlist_add usually sets it */ 568 calloutp = malloc(sizeof(*calloutp), M_KQUEUE, M_WAITOK); 569 callout_init(calloutp, CALLOUT_MPSAFE); 570 kn->kn_hook = calloutp; 571 callout_reset_sbt_on(calloutp, 572 timer2sbintime(kn->kn_sdata), 0 /* 1ms? */, 573 filt_timerexpire, kn, PCPU_GET(cpuid), 0); 574 575 return (0); 576 } 577 578 static void 579 filt_timerdetach(struct knote *kn) 580 { 581 struct callout *calloutp; 582 unsigned int old; 583 584 calloutp = (struct callout *)kn->kn_hook; 585 callout_drain(calloutp); 586 free(calloutp, M_KQUEUE); 587 old = atomic_fetch_sub_explicit(&kq_ncallouts, 1, memory_order_relaxed); 588 KASSERT(old > 0, ("Number of callouts cannot become negative")); 589 kn->kn_status |= KN_DETACHED; /* knlist_remove usually clears it */ 590 } 591 592 static int 593 filt_timer(struct knote *kn, long hint) 594 { 595 596 return (kn->kn_data != 0); 597 } 598 599 static int 600 filt_userattach(struct knote *kn) 601 { 602 603 /* 604 * EVFILT_USER knotes are not attached to anything in the kernel. 605 */ 606 kn->kn_hook = NULL; 607 if (kn->kn_fflags & NOTE_TRIGGER) 608 kn->kn_hookid = 1; 609 else 610 kn->kn_hookid = 0; 611 return (0); 612 } 613 614 static void 615 filt_userdetach(__unused struct knote *kn) 616 { 617 618 /* 619 * EVFILT_USER knotes are not attached to anything in the kernel. 620 */ 621 } 622 623 static int 624 filt_user(struct knote *kn, __unused long hint) 625 { 626 627 return (kn->kn_hookid); 628 } 629 630 static void 631 filt_usertouch(struct knote *kn, struct kevent *kev, u_long type) 632 { 633 u_int ffctrl; 634 635 switch (type) { 636 case EVENT_REGISTER: 637 if (kev->fflags & NOTE_TRIGGER) 638 kn->kn_hookid = 1; 639 640 ffctrl = kev->fflags & NOTE_FFCTRLMASK; 641 kev->fflags &= NOTE_FFLAGSMASK; 642 switch (ffctrl) { 643 case NOTE_FFNOP: 644 break; 645 646 case NOTE_FFAND: 647 kn->kn_sfflags &= kev->fflags; 648 break; 649 650 case NOTE_FFOR: 651 kn->kn_sfflags |= kev->fflags; 652 break; 653 654 case NOTE_FFCOPY: 655 kn->kn_sfflags = kev->fflags; 656 break; 657 658 default: 659 /* XXX Return error? */ 660 break; 661 } 662 kn->kn_sdata = kev->data; 663 if (kev->flags & EV_CLEAR) { 664 kn->kn_hookid = 0; 665 kn->kn_data = 0; 666 kn->kn_fflags = 0; 667 } 668 break; 669 670 case EVENT_PROCESS: 671 *kev = kn->kn_kevent; 672 kev->fflags = kn->kn_sfflags; 673 kev->data = kn->kn_sdata; 674 if (kn->kn_flags & EV_CLEAR) { 675 kn->kn_hookid = 0; 676 kn->kn_data = 0; 677 kn->kn_fflags = 0; 678 } 679 break; 680 681 default: 682 panic("filt_usertouch() - invalid type (%ld)", type); 683 break; 684 } 685 } 686 687 int 688 sys_kqueue(struct thread *td, struct kqueue_args *uap) 689 { 690 struct filedesc *fdp; 691 struct kqueue *kq; 692 struct file *fp; 693 int fd, error; 694 695 fdp = td->td_proc->p_fd; 696 error = falloc(td, &fp, &fd, 0); 697 if (error) 698 goto done2; 699 700 /* An extra reference on `fp' has been held for us by falloc(). */ 701 kq = malloc(sizeof *kq, M_KQUEUE, M_WAITOK | M_ZERO); 702 mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF|MTX_DUPOK); 703 TAILQ_INIT(&kq->kq_head); 704 kq->kq_fdp = fdp; 705 knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock); 706 TASK_INIT(&kq->kq_task, 0, kqueue_task, kq); 707 708 FILEDESC_XLOCK(fdp); 709 SLIST_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list); 710 FILEDESC_XUNLOCK(fdp); 711 712 finit(fp, FREAD | FWRITE, DTYPE_KQUEUE, kq, &kqueueops); 713 fdrop(fp, td); 714 715 td->td_retval[0] = fd; 716 done2: 717 return (error); 718 } 719 720 #ifndef _SYS_SYSPROTO_H_ 721 struct kevent_args { 722 int fd; 723 const struct kevent *changelist; 724 int nchanges; 725 struct kevent *eventlist; 726 int nevents; 727 const struct timespec *timeout; 728 }; 729 #endif 730 int 731 sys_kevent(struct thread *td, struct kevent_args *uap) 732 { 733 struct timespec ts, *tsp; 734 struct kevent_copyops k_ops = { uap, 735 kevent_copyout, 736 kevent_copyin}; 737 int error; 738 #ifdef KTRACE 739 struct uio ktruio; 740 struct iovec ktriov; 741 struct uio *ktruioin = NULL; 742 struct uio *ktruioout = NULL; 743 #endif 744 745 if (uap->timeout != NULL) { 746 error = copyin(uap->timeout, &ts, sizeof(ts)); 747 if (error) 748 return (error); 749 tsp = &ts; 750 } else 751 tsp = NULL; 752 753 #ifdef KTRACE 754 if (KTRPOINT(td, KTR_GENIO)) { 755 ktriov.iov_base = uap->changelist; 756 ktriov.iov_len = uap->nchanges * sizeof(struct kevent); 757 ktruio = (struct uio){ .uio_iov = &ktriov, .uio_iovcnt = 1, 758 .uio_segflg = UIO_USERSPACE, .uio_rw = UIO_READ, 759 .uio_td = td }; 760 ktruioin = cloneuio(&ktruio); 761 ktriov.iov_base = uap->eventlist; 762 ktriov.iov_len = uap->nevents * sizeof(struct kevent); 763 ktruioout = cloneuio(&ktruio); 764 } 765 #endif 766 767 error = kern_kevent(td, uap->fd, uap->nchanges, uap->nevents, 768 &k_ops, tsp); 769 770 #ifdef KTRACE 771 if (ktruioin != NULL) { 772 ktruioin->uio_resid = uap->nchanges * sizeof(struct kevent); 773 ktrgenio(uap->fd, UIO_WRITE, ktruioin, 0); 774 ktruioout->uio_resid = td->td_retval[0] * sizeof(struct kevent); 775 ktrgenio(uap->fd, UIO_READ, ktruioout, error); 776 } 777 #endif 778 779 return (error); 780 } 781 782 /* 783 * Copy 'count' items into the destination list pointed to by uap->eventlist. 784 */ 785 static int 786 kevent_copyout(void *arg, struct kevent *kevp, int count) 787 { 788 struct kevent_args *uap; 789 int error; 790 791 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 792 uap = (struct kevent_args *)arg; 793 794 error = copyout(kevp, uap->eventlist, count * sizeof *kevp); 795 if (error == 0) 796 uap->eventlist += count; 797 return (error); 798 } 799 800 /* 801 * Copy 'count' items from the list pointed to by uap->changelist. 802 */ 803 static int 804 kevent_copyin(void *arg, struct kevent *kevp, int count) 805 { 806 struct kevent_args *uap; 807 int error; 808 809 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 810 uap = (struct kevent_args *)arg; 811 812 error = copyin(uap->changelist, kevp, count * sizeof *kevp); 813 if (error == 0) 814 uap->changelist += count; 815 return (error); 816 } 817 818 int 819 kern_kevent(struct thread *td, int fd, int nchanges, int nevents, 820 struct kevent_copyops *k_ops, const struct timespec *timeout) 821 { 822 struct kevent keva[KQ_NEVENTS]; 823 struct kevent *kevp, *changes; 824 struct kqueue *kq; 825 struct file *fp; 826 int i, n, nerrors, error; 827 828 if ((error = fget(td, fd, CAP_POST_EVENT, &fp)) != 0) 829 return (error); 830 if ((error = kqueue_acquire(fp, &kq)) != 0) 831 goto done_norel; 832 833 nerrors = 0; 834 835 while (nchanges > 0) { 836 n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges; 837 error = k_ops->k_copyin(k_ops->arg, keva, n); 838 if (error) 839 goto done; 840 changes = keva; 841 for (i = 0; i < n; i++) { 842 kevp = &changes[i]; 843 if (!kevp->filter) 844 continue; 845 kevp->flags &= ~EV_SYSFLAGS; 846 error = kqueue_register(kq, kevp, td, 1); 847 if (error || (kevp->flags & EV_RECEIPT)) { 848 if (nevents != 0) { 849 kevp->flags = EV_ERROR; 850 kevp->data = error; 851 (void) k_ops->k_copyout(k_ops->arg, 852 kevp, 1); 853 nevents--; 854 nerrors++; 855 } else { 856 goto done; 857 } 858 } 859 } 860 nchanges -= n; 861 } 862 if (nerrors) { 863 td->td_retval[0] = nerrors; 864 error = 0; 865 goto done; 866 } 867 868 error = kqueue_scan(kq, nevents, k_ops, timeout, keva, td); 869 done: 870 kqueue_release(kq, 0); 871 done_norel: 872 fdrop(fp, td); 873 return (error); 874 } 875 876 int 877 kqueue_add_filteropts(int filt, struct filterops *filtops) 878 { 879 int error; 880 881 error = 0; 882 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) { 883 printf( 884 "trying to add a filterop that is out of range: %d is beyond %d\n", 885 ~filt, EVFILT_SYSCOUNT); 886 return EINVAL; 887 } 888 mtx_lock(&filterops_lock); 889 if (sysfilt_ops[~filt].for_fop != &null_filtops && 890 sysfilt_ops[~filt].for_fop != NULL) 891 error = EEXIST; 892 else { 893 sysfilt_ops[~filt].for_fop = filtops; 894 sysfilt_ops[~filt].for_refcnt = 0; 895 } 896 mtx_unlock(&filterops_lock); 897 898 return (error); 899 } 900 901 int 902 kqueue_del_filteropts(int filt) 903 { 904 int error; 905 906 error = 0; 907 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 908 return EINVAL; 909 910 mtx_lock(&filterops_lock); 911 if (sysfilt_ops[~filt].for_fop == &null_filtops || 912 sysfilt_ops[~filt].for_fop == NULL) 913 error = EINVAL; 914 else if (sysfilt_ops[~filt].for_refcnt != 0) 915 error = EBUSY; 916 else { 917 sysfilt_ops[~filt].for_fop = &null_filtops; 918 sysfilt_ops[~filt].for_refcnt = 0; 919 } 920 mtx_unlock(&filterops_lock); 921 922 return error; 923 } 924 925 static struct filterops * 926 kqueue_fo_find(int filt) 927 { 928 929 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 930 return NULL; 931 932 mtx_lock(&filterops_lock); 933 sysfilt_ops[~filt].for_refcnt++; 934 if (sysfilt_ops[~filt].for_fop == NULL) 935 sysfilt_ops[~filt].for_fop = &null_filtops; 936 mtx_unlock(&filterops_lock); 937 938 return sysfilt_ops[~filt].for_fop; 939 } 940 941 static void 942 kqueue_fo_release(int filt) 943 { 944 945 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 946 return; 947 948 mtx_lock(&filterops_lock); 949 KASSERT(sysfilt_ops[~filt].for_refcnt > 0, 950 ("filter object refcount not valid on release")); 951 sysfilt_ops[~filt].for_refcnt--; 952 mtx_unlock(&filterops_lock); 953 } 954 955 /* 956 * A ref to kq (obtained via kqueue_acquire) must be held. waitok will 957 * influence if memory allocation should wait. Make sure it is 0 if you 958 * hold any mutexes. 959 */ 960 static int 961 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, int waitok) 962 { 963 struct filterops *fops; 964 struct file *fp; 965 struct knote *kn, *tkn; 966 int error, filt, event; 967 int haskqglobal; 968 969 fp = NULL; 970 kn = NULL; 971 error = 0; 972 haskqglobal = 0; 973 974 filt = kev->filter; 975 fops = kqueue_fo_find(filt); 976 if (fops == NULL) 977 return EINVAL; 978 979 tkn = knote_alloc(waitok); /* prevent waiting with locks */ 980 981 findkn: 982 if (fops->f_isfd) { 983 KASSERT(td != NULL, ("td is NULL")); 984 error = fget(td, kev->ident, CAP_POLL_EVENT, &fp); 985 if (error) 986 goto done; 987 988 if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops, 989 kev->ident, 0) != 0) { 990 /* try again */ 991 fdrop(fp, td); 992 fp = NULL; 993 error = kqueue_expand(kq, fops, kev->ident, waitok); 994 if (error) 995 goto done; 996 goto findkn; 997 } 998 999 if (fp->f_type == DTYPE_KQUEUE) { 1000 /* 1001 * if we add some inteligence about what we are doing, 1002 * we should be able to support events on ourselves. 1003 * We need to know when we are doing this to prevent 1004 * getting both the knlist lock and the kq lock since 1005 * they are the same thing. 1006 */ 1007 if (fp->f_data == kq) { 1008 error = EINVAL; 1009 goto done; 1010 } 1011 1012 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1013 } 1014 1015 KQ_LOCK(kq); 1016 if (kev->ident < kq->kq_knlistsize) { 1017 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link) 1018 if (kev->filter == kn->kn_filter) 1019 break; 1020 } 1021 } else { 1022 if ((kev->flags & EV_ADD) == EV_ADD) 1023 kqueue_expand(kq, fops, kev->ident, waitok); 1024 1025 KQ_LOCK(kq); 1026 if (kq->kq_knhashmask != 0) { 1027 struct klist *list; 1028 1029 list = &kq->kq_knhash[ 1030 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)]; 1031 SLIST_FOREACH(kn, list, kn_link) 1032 if (kev->ident == kn->kn_id && 1033 kev->filter == kn->kn_filter) 1034 break; 1035 } 1036 } 1037 1038 /* knote is in the process of changing, wait for it to stablize. */ 1039 if (kn != NULL && (kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1040 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1041 kq->kq_state |= KQ_FLUXWAIT; 1042 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0); 1043 if (fp != NULL) { 1044 fdrop(fp, td); 1045 fp = NULL; 1046 } 1047 goto findkn; 1048 } 1049 1050 /* 1051 * kn now contains the matching knote, or NULL if no match 1052 */ 1053 if (kn == NULL) { 1054 if (kev->flags & EV_ADD) { 1055 kn = tkn; 1056 tkn = NULL; 1057 if (kn == NULL) { 1058 KQ_UNLOCK(kq); 1059 error = ENOMEM; 1060 goto done; 1061 } 1062 kn->kn_fp = fp; 1063 kn->kn_kq = kq; 1064 kn->kn_fop = fops; 1065 /* 1066 * apply reference counts to knote structure, and 1067 * do not release it at the end of this routine. 1068 */ 1069 fops = NULL; 1070 fp = NULL; 1071 1072 kn->kn_sfflags = kev->fflags; 1073 kn->kn_sdata = kev->data; 1074 kev->fflags = 0; 1075 kev->data = 0; 1076 kn->kn_kevent = *kev; 1077 kn->kn_kevent.flags &= ~(EV_ADD | EV_DELETE | 1078 EV_ENABLE | EV_DISABLE); 1079 kn->kn_status = KN_INFLUX|KN_DETACHED; 1080 1081 error = knote_attach(kn, kq); 1082 KQ_UNLOCK(kq); 1083 if (error != 0) { 1084 tkn = kn; 1085 goto done; 1086 } 1087 1088 if ((error = kn->kn_fop->f_attach(kn)) != 0) { 1089 knote_drop(kn, td); 1090 goto done; 1091 } 1092 KN_LIST_LOCK(kn); 1093 goto done_ev_add; 1094 } else { 1095 /* No matching knote and the EV_ADD flag is not set. */ 1096 KQ_UNLOCK(kq); 1097 error = ENOENT; 1098 goto done; 1099 } 1100 } 1101 1102 if (kev->flags & EV_DELETE) { 1103 kn->kn_status |= KN_INFLUX; 1104 KQ_UNLOCK(kq); 1105 if (!(kn->kn_status & KN_DETACHED)) 1106 kn->kn_fop->f_detach(kn); 1107 knote_drop(kn, td); 1108 goto done; 1109 } 1110 1111 /* 1112 * The user may change some filter values after the initial EV_ADD, 1113 * but doing so will not reset any filter which has already been 1114 * triggered. 1115 */ 1116 kn->kn_status |= KN_INFLUX; 1117 KQ_UNLOCK(kq); 1118 KN_LIST_LOCK(kn); 1119 kn->kn_kevent.udata = kev->udata; 1120 if (!fops->f_isfd && fops->f_touch != NULL) { 1121 fops->f_touch(kn, kev, EVENT_REGISTER); 1122 } else { 1123 kn->kn_sfflags = kev->fflags; 1124 kn->kn_sdata = kev->data; 1125 } 1126 1127 /* 1128 * We can get here with kn->kn_knlist == NULL. This can happen when 1129 * the initial attach event decides that the event is "completed" 1130 * already. i.e. filt_procattach is called on a zombie process. It 1131 * will call filt_proc which will remove it from the list, and NULL 1132 * kn_knlist. 1133 */ 1134 done_ev_add: 1135 event = kn->kn_fop->f_event(kn, 0); 1136 KQ_LOCK(kq); 1137 if (event) 1138 KNOTE_ACTIVATE(kn, 1); 1139 kn->kn_status &= ~KN_INFLUX; 1140 KN_LIST_UNLOCK(kn); 1141 1142 if ((kev->flags & EV_DISABLE) && 1143 ((kn->kn_status & KN_DISABLED) == 0)) { 1144 kn->kn_status |= KN_DISABLED; 1145 } 1146 1147 if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) { 1148 kn->kn_status &= ~KN_DISABLED; 1149 if ((kn->kn_status & KN_ACTIVE) && 1150 ((kn->kn_status & KN_QUEUED) == 0)) 1151 knote_enqueue(kn); 1152 } 1153 KQ_UNLOCK_FLUX(kq); 1154 1155 done: 1156 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1157 if (fp != NULL) 1158 fdrop(fp, td); 1159 if (tkn != NULL) 1160 knote_free(tkn); 1161 if (fops != NULL) 1162 kqueue_fo_release(filt); 1163 return (error); 1164 } 1165 1166 static int 1167 kqueue_acquire(struct file *fp, struct kqueue **kqp) 1168 { 1169 int error; 1170 struct kqueue *kq; 1171 1172 error = 0; 1173 1174 kq = fp->f_data; 1175 if (fp->f_type != DTYPE_KQUEUE || kq == NULL) 1176 return (EBADF); 1177 *kqp = kq; 1178 KQ_LOCK(kq); 1179 if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) { 1180 KQ_UNLOCK(kq); 1181 return (EBADF); 1182 } 1183 kq->kq_refcnt++; 1184 KQ_UNLOCK(kq); 1185 1186 return error; 1187 } 1188 1189 static void 1190 kqueue_release(struct kqueue *kq, int locked) 1191 { 1192 if (locked) 1193 KQ_OWNED(kq); 1194 else 1195 KQ_LOCK(kq); 1196 kq->kq_refcnt--; 1197 if (kq->kq_refcnt == 1) 1198 wakeup(&kq->kq_refcnt); 1199 if (!locked) 1200 KQ_UNLOCK(kq); 1201 } 1202 1203 static void 1204 kqueue_schedtask(struct kqueue *kq) 1205 { 1206 1207 KQ_OWNED(kq); 1208 KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN), 1209 ("scheduling kqueue task while draining")); 1210 1211 if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) { 1212 taskqueue_enqueue(taskqueue_kqueue, &kq->kq_task); 1213 kq->kq_state |= KQ_TASKSCHED; 1214 } 1215 } 1216 1217 /* 1218 * Expand the kq to make sure we have storage for fops/ident pair. 1219 * 1220 * Return 0 on success (or no work necessary), return errno on failure. 1221 * 1222 * Not calling hashinit w/ waitok (proper malloc flag) should be safe. 1223 * If kqueue_register is called from a non-fd context, there usually/should 1224 * be no locks held. 1225 */ 1226 static int 1227 kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident, 1228 int waitok) 1229 { 1230 struct klist *list, *tmp_knhash, *to_free; 1231 u_long tmp_knhashmask; 1232 int size; 1233 int fd; 1234 int mflag = waitok ? M_WAITOK : M_NOWAIT; 1235 1236 KQ_NOTOWNED(kq); 1237 1238 to_free = NULL; 1239 if (fops->f_isfd) { 1240 fd = ident; 1241 if (kq->kq_knlistsize <= fd) { 1242 size = kq->kq_knlistsize; 1243 while (size <= fd) 1244 size += KQEXTENT; 1245 list = malloc(size * sizeof(*list), M_KQUEUE, mflag); 1246 if (list == NULL) 1247 return ENOMEM; 1248 KQ_LOCK(kq); 1249 if (kq->kq_knlistsize > fd) { 1250 to_free = list; 1251 list = NULL; 1252 } else { 1253 if (kq->kq_knlist != NULL) { 1254 bcopy(kq->kq_knlist, list, 1255 kq->kq_knlistsize * sizeof(*list)); 1256 to_free = kq->kq_knlist; 1257 kq->kq_knlist = NULL; 1258 } 1259 bzero((caddr_t)list + 1260 kq->kq_knlistsize * sizeof(*list), 1261 (size - kq->kq_knlistsize) * sizeof(*list)); 1262 kq->kq_knlistsize = size; 1263 kq->kq_knlist = list; 1264 } 1265 KQ_UNLOCK(kq); 1266 } 1267 } else { 1268 if (kq->kq_knhashmask == 0) { 1269 tmp_knhash = hashinit(KN_HASHSIZE, M_KQUEUE, 1270 &tmp_knhashmask); 1271 if (tmp_knhash == NULL) 1272 return ENOMEM; 1273 KQ_LOCK(kq); 1274 if (kq->kq_knhashmask == 0) { 1275 kq->kq_knhash = tmp_knhash; 1276 kq->kq_knhashmask = tmp_knhashmask; 1277 } else { 1278 to_free = tmp_knhash; 1279 } 1280 KQ_UNLOCK(kq); 1281 } 1282 } 1283 free(to_free, M_KQUEUE); 1284 1285 KQ_NOTOWNED(kq); 1286 return 0; 1287 } 1288 1289 static void 1290 kqueue_task(void *arg, int pending) 1291 { 1292 struct kqueue *kq; 1293 int haskqglobal; 1294 1295 haskqglobal = 0; 1296 kq = arg; 1297 1298 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1299 KQ_LOCK(kq); 1300 1301 KNOTE_LOCKED(&kq->kq_sel.si_note, 0); 1302 1303 kq->kq_state &= ~KQ_TASKSCHED; 1304 if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) { 1305 wakeup(&kq->kq_state); 1306 } 1307 KQ_UNLOCK(kq); 1308 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1309 } 1310 1311 /* 1312 * Scan, update kn_data (if not ONESHOT), and copyout triggered events. 1313 * We treat KN_MARKER knotes as if they are INFLUX. 1314 */ 1315 static int 1316 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops, 1317 const struct timespec *tsp, struct kevent *keva, struct thread *td) 1318 { 1319 struct kevent *kevp; 1320 struct knote *kn, *marker; 1321 sbintime_t asbt, rsbt; 1322 int count, error, haskqglobal, influx, nkev, touch; 1323 1324 count = maxevents; 1325 nkev = 0; 1326 error = 0; 1327 haskqglobal = 0; 1328 1329 if (maxevents == 0) 1330 goto done_nl; 1331 1332 rsbt = 0; 1333 if (tsp != NULL) { 1334 if (tsp->tv_sec < 0 || tsp->tv_nsec < 0 || 1335 tsp->tv_nsec >= 1000000000) { 1336 error = EINVAL; 1337 goto done_nl; 1338 } 1339 if (timespecisset(tsp)) { 1340 if (tsp->tv_sec <= INT32_MAX) { 1341 rsbt = tstosbt(*tsp); 1342 if (TIMESEL(&asbt, rsbt)) 1343 asbt += tc_tick_sbt; 1344 if (asbt <= INT64_MAX - rsbt) 1345 asbt += rsbt; 1346 else 1347 asbt = 0; 1348 rsbt >>= tc_precexp; 1349 } else 1350 asbt = 0; 1351 } else 1352 asbt = -1; 1353 } else 1354 asbt = 0; 1355 marker = knote_alloc(1); 1356 if (marker == NULL) { 1357 error = ENOMEM; 1358 goto done_nl; 1359 } 1360 marker->kn_status = KN_MARKER; 1361 KQ_LOCK(kq); 1362 1363 retry: 1364 kevp = keva; 1365 if (kq->kq_count == 0) { 1366 if (asbt == -1) { 1367 error = EWOULDBLOCK; 1368 } else { 1369 kq->kq_state |= KQ_SLEEP; 1370 error = msleep_sbt(kq, &kq->kq_lock, PSOCK | PCATCH, 1371 "kqread", asbt, rsbt, C_ABSOLUTE); 1372 } 1373 if (error == 0) 1374 goto retry; 1375 /* don't restart after signals... */ 1376 if (error == ERESTART) 1377 error = EINTR; 1378 else if (error == EWOULDBLOCK) 1379 error = 0; 1380 goto done; 1381 } 1382 1383 TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); 1384 influx = 0; 1385 while (count) { 1386 KQ_OWNED(kq); 1387 kn = TAILQ_FIRST(&kq->kq_head); 1388 1389 if ((kn->kn_status == KN_MARKER && kn != marker) || 1390 (kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1391 if (influx) { 1392 influx = 0; 1393 KQ_FLUX_WAKEUP(kq); 1394 } 1395 kq->kq_state |= KQ_FLUXWAIT; 1396 error = msleep(kq, &kq->kq_lock, PSOCK, 1397 "kqflxwt", 0); 1398 continue; 1399 } 1400 1401 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1402 if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) { 1403 kn->kn_status &= ~KN_QUEUED; 1404 kq->kq_count--; 1405 continue; 1406 } 1407 if (kn == marker) { 1408 KQ_FLUX_WAKEUP(kq); 1409 if (count == maxevents) 1410 goto retry; 1411 goto done; 1412 } 1413 KASSERT((kn->kn_status & KN_INFLUX) == 0, 1414 ("KN_INFLUX set when not suppose to be")); 1415 1416 if ((kn->kn_flags & EV_DROP) == EV_DROP) { 1417 kn->kn_status &= ~KN_QUEUED; 1418 kn->kn_status |= KN_INFLUX; 1419 kq->kq_count--; 1420 KQ_UNLOCK(kq); 1421 /* 1422 * We don't need to lock the list since we've marked 1423 * it _INFLUX. 1424 */ 1425 if (!(kn->kn_status & KN_DETACHED)) 1426 kn->kn_fop->f_detach(kn); 1427 knote_drop(kn, td); 1428 KQ_LOCK(kq); 1429 continue; 1430 } else if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) { 1431 kn->kn_status &= ~KN_QUEUED; 1432 kn->kn_status |= KN_INFLUX; 1433 kq->kq_count--; 1434 KQ_UNLOCK(kq); 1435 /* 1436 * We don't need to lock the list since we've marked 1437 * it _INFLUX. 1438 */ 1439 *kevp = kn->kn_kevent; 1440 if (!(kn->kn_status & KN_DETACHED)) 1441 kn->kn_fop->f_detach(kn); 1442 knote_drop(kn, td); 1443 KQ_LOCK(kq); 1444 kn = NULL; 1445 } else { 1446 kn->kn_status |= KN_INFLUX; 1447 KQ_UNLOCK(kq); 1448 if ((kn->kn_status & KN_KQUEUE) == KN_KQUEUE) 1449 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1450 KN_LIST_LOCK(kn); 1451 if (kn->kn_fop->f_event(kn, 0) == 0) { 1452 KQ_LOCK(kq); 1453 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1454 kn->kn_status &= 1455 ~(KN_QUEUED | KN_ACTIVE | KN_INFLUX); 1456 kq->kq_count--; 1457 KN_LIST_UNLOCK(kn); 1458 influx = 1; 1459 continue; 1460 } 1461 touch = (!kn->kn_fop->f_isfd && 1462 kn->kn_fop->f_touch != NULL); 1463 if (touch) 1464 kn->kn_fop->f_touch(kn, kevp, EVENT_PROCESS); 1465 else 1466 *kevp = kn->kn_kevent; 1467 KQ_LOCK(kq); 1468 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1469 if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) { 1470 /* 1471 * Manually clear knotes who weren't 1472 * 'touch'ed. 1473 */ 1474 if (touch == 0 && kn->kn_flags & EV_CLEAR) { 1475 kn->kn_data = 0; 1476 kn->kn_fflags = 0; 1477 } 1478 if (kn->kn_flags & EV_DISPATCH) 1479 kn->kn_status |= KN_DISABLED; 1480 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 1481 kq->kq_count--; 1482 } else 1483 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 1484 1485 kn->kn_status &= ~(KN_INFLUX); 1486 KN_LIST_UNLOCK(kn); 1487 influx = 1; 1488 } 1489 1490 /* we are returning a copy to the user */ 1491 kevp++; 1492 nkev++; 1493 count--; 1494 1495 if (nkev == KQ_NEVENTS) { 1496 influx = 0; 1497 KQ_UNLOCK_FLUX(kq); 1498 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1499 nkev = 0; 1500 kevp = keva; 1501 KQ_LOCK(kq); 1502 if (error) 1503 break; 1504 } 1505 } 1506 TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); 1507 done: 1508 KQ_OWNED(kq); 1509 KQ_UNLOCK_FLUX(kq); 1510 knote_free(marker); 1511 done_nl: 1512 KQ_NOTOWNED(kq); 1513 if (nkev != 0) 1514 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1515 td->td_retval[0] = maxevents - count; 1516 return (error); 1517 } 1518 1519 /* 1520 * XXX 1521 * This could be expanded to call kqueue_scan, if desired. 1522 */ 1523 /*ARGSUSED*/ 1524 static int 1525 kqueue_read(struct file *fp, struct uio *uio, struct ucred *active_cred, 1526 int flags, struct thread *td) 1527 { 1528 return (ENXIO); 1529 } 1530 1531 /*ARGSUSED*/ 1532 static int 1533 kqueue_write(struct file *fp, struct uio *uio, struct ucred *active_cred, 1534 int flags, struct thread *td) 1535 { 1536 return (ENXIO); 1537 } 1538 1539 /*ARGSUSED*/ 1540 static int 1541 kqueue_truncate(struct file *fp, off_t length, struct ucred *active_cred, 1542 struct thread *td) 1543 { 1544 1545 return (EINVAL); 1546 } 1547 1548 /*ARGSUSED*/ 1549 static int 1550 kqueue_ioctl(struct file *fp, u_long cmd, void *data, 1551 struct ucred *active_cred, struct thread *td) 1552 { 1553 /* 1554 * Enabling sigio causes two major problems: 1555 * 1) infinite recursion: 1556 * Synopsys: kevent is being used to track signals and have FIOASYNC 1557 * set. On receipt of a signal this will cause a kqueue to recurse 1558 * into itself over and over. Sending the sigio causes the kqueue 1559 * to become ready, which in turn posts sigio again, forever. 1560 * Solution: this can be solved by setting a flag in the kqueue that 1561 * we have a SIGIO in progress. 1562 * 2) locking problems: 1563 * Synopsys: Kqueue is a leaf subsystem, but adding signalling puts 1564 * us above the proc and pgrp locks. 1565 * Solution: Post a signal using an async mechanism, being sure to 1566 * record a generation count in the delivery so that we do not deliver 1567 * a signal to the wrong process. 1568 * 1569 * Note, these two mechanisms are somewhat mutually exclusive! 1570 */ 1571 #if 0 1572 struct kqueue *kq; 1573 1574 kq = fp->f_data; 1575 switch (cmd) { 1576 case FIOASYNC: 1577 if (*(int *)data) { 1578 kq->kq_state |= KQ_ASYNC; 1579 } else { 1580 kq->kq_state &= ~KQ_ASYNC; 1581 } 1582 return (0); 1583 1584 case FIOSETOWN: 1585 return (fsetown(*(int *)data, &kq->kq_sigio)); 1586 1587 case FIOGETOWN: 1588 *(int *)data = fgetown(&kq->kq_sigio); 1589 return (0); 1590 } 1591 #endif 1592 1593 return (ENOTTY); 1594 } 1595 1596 /*ARGSUSED*/ 1597 static int 1598 kqueue_poll(struct file *fp, int events, struct ucred *active_cred, 1599 struct thread *td) 1600 { 1601 struct kqueue *kq; 1602 int revents = 0; 1603 int error; 1604 1605 if ((error = kqueue_acquire(fp, &kq))) 1606 return POLLERR; 1607 1608 KQ_LOCK(kq); 1609 if (events & (POLLIN | POLLRDNORM)) { 1610 if (kq->kq_count) { 1611 revents |= events & (POLLIN | POLLRDNORM); 1612 } else { 1613 selrecord(td, &kq->kq_sel); 1614 if (SEL_WAITING(&kq->kq_sel)) 1615 kq->kq_state |= KQ_SEL; 1616 } 1617 } 1618 kqueue_release(kq, 1); 1619 KQ_UNLOCK(kq); 1620 return (revents); 1621 } 1622 1623 /*ARGSUSED*/ 1624 static int 1625 kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred, 1626 struct thread *td) 1627 { 1628 1629 bzero((void *)st, sizeof *st); 1630 /* 1631 * We no longer return kq_count because the unlocked value is useless. 1632 * If you spent all this time getting the count, why not spend your 1633 * syscall better by calling kevent? 1634 * 1635 * XXX - This is needed for libc_r. 1636 */ 1637 st->st_mode = S_IFIFO; 1638 return (0); 1639 } 1640 1641 /*ARGSUSED*/ 1642 static int 1643 kqueue_close(struct file *fp, struct thread *td) 1644 { 1645 struct kqueue *kq = fp->f_data; 1646 struct filedesc *fdp; 1647 struct knote *kn; 1648 int i; 1649 int error; 1650 1651 if ((error = kqueue_acquire(fp, &kq))) 1652 return error; 1653 1654 KQ_LOCK(kq); 1655 1656 KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING, 1657 ("kqueue already closing")); 1658 kq->kq_state |= KQ_CLOSING; 1659 if (kq->kq_refcnt > 1) 1660 msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0); 1661 1662 KASSERT(kq->kq_refcnt == 1, ("other refs are out there!")); 1663 fdp = kq->kq_fdp; 1664 1665 KASSERT(knlist_empty(&kq->kq_sel.si_note), 1666 ("kqueue's knlist not empty")); 1667 1668 for (i = 0; i < kq->kq_knlistsize; i++) { 1669 while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) { 1670 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1671 kq->kq_state |= KQ_FLUXWAIT; 1672 msleep(kq, &kq->kq_lock, PSOCK, "kqclo1", 0); 1673 continue; 1674 } 1675 kn->kn_status |= KN_INFLUX; 1676 KQ_UNLOCK(kq); 1677 if (!(kn->kn_status & KN_DETACHED)) 1678 kn->kn_fop->f_detach(kn); 1679 knote_drop(kn, td); 1680 KQ_LOCK(kq); 1681 } 1682 } 1683 if (kq->kq_knhashmask != 0) { 1684 for (i = 0; i <= kq->kq_knhashmask; i++) { 1685 while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) { 1686 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1687 kq->kq_state |= KQ_FLUXWAIT; 1688 msleep(kq, &kq->kq_lock, PSOCK, 1689 "kqclo2", 0); 1690 continue; 1691 } 1692 kn->kn_status |= KN_INFLUX; 1693 KQ_UNLOCK(kq); 1694 if (!(kn->kn_status & KN_DETACHED)) 1695 kn->kn_fop->f_detach(kn); 1696 knote_drop(kn, td); 1697 KQ_LOCK(kq); 1698 } 1699 } 1700 } 1701 1702 if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) { 1703 kq->kq_state |= KQ_TASKDRAIN; 1704 msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0); 1705 } 1706 1707 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 1708 selwakeuppri(&kq->kq_sel, PSOCK); 1709 if (!SEL_WAITING(&kq->kq_sel)) 1710 kq->kq_state &= ~KQ_SEL; 1711 } 1712 1713 KQ_UNLOCK(kq); 1714 1715 FILEDESC_XLOCK(fdp); 1716 SLIST_REMOVE(&fdp->fd_kqlist, kq, kqueue, kq_list); 1717 FILEDESC_XUNLOCK(fdp); 1718 1719 seldrain(&kq->kq_sel); 1720 knlist_destroy(&kq->kq_sel.si_note); 1721 mtx_destroy(&kq->kq_lock); 1722 kq->kq_fdp = NULL; 1723 1724 if (kq->kq_knhash != NULL) 1725 free(kq->kq_knhash, M_KQUEUE); 1726 if (kq->kq_knlist != NULL) 1727 free(kq->kq_knlist, M_KQUEUE); 1728 1729 funsetown(&kq->kq_sigio); 1730 free(kq, M_KQUEUE); 1731 fp->f_data = NULL; 1732 1733 return (0); 1734 } 1735 1736 static void 1737 kqueue_wakeup(struct kqueue *kq) 1738 { 1739 KQ_OWNED(kq); 1740 1741 if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) { 1742 kq->kq_state &= ~KQ_SLEEP; 1743 wakeup(kq); 1744 } 1745 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 1746 selwakeuppri(&kq->kq_sel, PSOCK); 1747 if (!SEL_WAITING(&kq->kq_sel)) 1748 kq->kq_state &= ~KQ_SEL; 1749 } 1750 if (!knlist_empty(&kq->kq_sel.si_note)) 1751 kqueue_schedtask(kq); 1752 if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) { 1753 pgsigio(&kq->kq_sigio, SIGIO, 0); 1754 } 1755 } 1756 1757 /* 1758 * Walk down a list of knotes, activating them if their event has triggered. 1759 * 1760 * There is a possibility to optimize in the case of one kq watching another. 1761 * Instead of scheduling a task to wake it up, you could pass enough state 1762 * down the chain to make up the parent kqueue. Make this code functional 1763 * first. 1764 */ 1765 void 1766 knote(struct knlist *list, long hint, int lockflags) 1767 { 1768 struct kqueue *kq; 1769 struct knote *kn; 1770 int error; 1771 1772 if (list == NULL) 1773 return; 1774 1775 KNL_ASSERT_LOCK(list, lockflags & KNF_LISTLOCKED); 1776 1777 if ((lockflags & KNF_LISTLOCKED) == 0) 1778 list->kl_lock(list->kl_lockarg); 1779 1780 /* 1781 * If we unlock the list lock (and set KN_INFLUX), we can eliminate 1782 * the kqueue scheduling, but this will introduce four 1783 * lock/unlock's for each knote to test. If we do, continue to use 1784 * SLIST_FOREACH, SLIST_FOREACH_SAFE is not safe in our case, it is 1785 * only safe if you want to remove the current item, which we are 1786 * not doing. 1787 */ 1788 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { 1789 kq = kn->kn_kq; 1790 if ((kn->kn_status & KN_INFLUX) != KN_INFLUX) { 1791 KQ_LOCK(kq); 1792 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1793 KQ_UNLOCK(kq); 1794 } else if ((lockflags & KNF_NOKQLOCK) != 0) { 1795 kn->kn_status |= KN_INFLUX; 1796 KQ_UNLOCK(kq); 1797 error = kn->kn_fop->f_event(kn, hint); 1798 KQ_LOCK(kq); 1799 kn->kn_status &= ~KN_INFLUX; 1800 if (error) 1801 KNOTE_ACTIVATE(kn, 1); 1802 KQ_UNLOCK_FLUX(kq); 1803 } else { 1804 kn->kn_status |= KN_HASKQLOCK; 1805 if (kn->kn_fop->f_event(kn, hint)) 1806 KNOTE_ACTIVATE(kn, 1); 1807 kn->kn_status &= ~KN_HASKQLOCK; 1808 KQ_UNLOCK(kq); 1809 } 1810 } 1811 kq = NULL; 1812 } 1813 if ((lockflags & KNF_LISTLOCKED) == 0) 1814 list->kl_unlock(list->kl_lockarg); 1815 } 1816 1817 /* 1818 * add a knote to a knlist 1819 */ 1820 void 1821 knlist_add(struct knlist *knl, struct knote *kn, int islocked) 1822 { 1823 KNL_ASSERT_LOCK(knl, islocked); 1824 KQ_NOTOWNED(kn->kn_kq); 1825 KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) == 1826 (KN_INFLUX|KN_DETACHED), ("knote not KN_INFLUX and KN_DETACHED")); 1827 if (!islocked) 1828 knl->kl_lock(knl->kl_lockarg); 1829 SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext); 1830 if (!islocked) 1831 knl->kl_unlock(knl->kl_lockarg); 1832 KQ_LOCK(kn->kn_kq); 1833 kn->kn_knlist = knl; 1834 kn->kn_status &= ~KN_DETACHED; 1835 KQ_UNLOCK(kn->kn_kq); 1836 } 1837 1838 static void 1839 knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked, int kqislocked) 1840 { 1841 KASSERT(!(!!kqislocked && !knlislocked), ("kq locked w/o knl locked")); 1842 KNL_ASSERT_LOCK(knl, knlislocked); 1843 mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED); 1844 if (!kqislocked) 1845 KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) == KN_INFLUX, 1846 ("knlist_remove called w/o knote being KN_INFLUX or already removed")); 1847 if (!knlislocked) 1848 knl->kl_lock(knl->kl_lockarg); 1849 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext); 1850 kn->kn_knlist = NULL; 1851 if (!knlislocked) 1852 knl->kl_unlock(knl->kl_lockarg); 1853 if (!kqislocked) 1854 KQ_LOCK(kn->kn_kq); 1855 kn->kn_status |= KN_DETACHED; 1856 if (!kqislocked) 1857 KQ_UNLOCK(kn->kn_kq); 1858 } 1859 1860 /* 1861 * remove all knotes from a specified klist 1862 */ 1863 void 1864 knlist_remove(struct knlist *knl, struct knote *kn, int islocked) 1865 { 1866 1867 knlist_remove_kq(knl, kn, islocked, 0); 1868 } 1869 1870 /* 1871 * remove knote from a specified klist while in f_event handler. 1872 */ 1873 void 1874 knlist_remove_inevent(struct knlist *knl, struct knote *kn) 1875 { 1876 1877 knlist_remove_kq(knl, kn, 1, 1878 (kn->kn_status & KN_HASKQLOCK) == KN_HASKQLOCK); 1879 } 1880 1881 int 1882 knlist_empty(struct knlist *knl) 1883 { 1884 1885 KNL_ASSERT_LOCKED(knl); 1886 return SLIST_EMPTY(&knl->kl_list); 1887 } 1888 1889 static struct mtx knlist_lock; 1890 MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects", 1891 MTX_DEF); 1892 static void knlist_mtx_lock(void *arg); 1893 static void knlist_mtx_unlock(void *arg); 1894 1895 static void 1896 knlist_mtx_lock(void *arg) 1897 { 1898 1899 mtx_lock((struct mtx *)arg); 1900 } 1901 1902 static void 1903 knlist_mtx_unlock(void *arg) 1904 { 1905 1906 mtx_unlock((struct mtx *)arg); 1907 } 1908 1909 static void 1910 knlist_mtx_assert_locked(void *arg) 1911 { 1912 1913 mtx_assert((struct mtx *)arg, MA_OWNED); 1914 } 1915 1916 static void 1917 knlist_mtx_assert_unlocked(void *arg) 1918 { 1919 1920 mtx_assert((struct mtx *)arg, MA_NOTOWNED); 1921 } 1922 1923 static void 1924 knlist_rw_rlock(void *arg) 1925 { 1926 1927 rw_rlock((struct rwlock *)arg); 1928 } 1929 1930 static void 1931 knlist_rw_runlock(void *arg) 1932 { 1933 1934 rw_runlock((struct rwlock *)arg); 1935 } 1936 1937 static void 1938 knlist_rw_assert_locked(void *arg) 1939 { 1940 1941 rw_assert((struct rwlock *)arg, RA_LOCKED); 1942 } 1943 1944 static void 1945 knlist_rw_assert_unlocked(void *arg) 1946 { 1947 1948 rw_assert((struct rwlock *)arg, RA_UNLOCKED); 1949 } 1950 1951 void 1952 knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *), 1953 void (*kl_unlock)(void *), 1954 void (*kl_assert_locked)(void *), void (*kl_assert_unlocked)(void *)) 1955 { 1956 1957 if (lock == NULL) 1958 knl->kl_lockarg = &knlist_lock; 1959 else 1960 knl->kl_lockarg = lock; 1961 1962 if (kl_lock == NULL) 1963 knl->kl_lock = knlist_mtx_lock; 1964 else 1965 knl->kl_lock = kl_lock; 1966 if (kl_unlock == NULL) 1967 knl->kl_unlock = knlist_mtx_unlock; 1968 else 1969 knl->kl_unlock = kl_unlock; 1970 if (kl_assert_locked == NULL) 1971 knl->kl_assert_locked = knlist_mtx_assert_locked; 1972 else 1973 knl->kl_assert_locked = kl_assert_locked; 1974 if (kl_assert_unlocked == NULL) 1975 knl->kl_assert_unlocked = knlist_mtx_assert_unlocked; 1976 else 1977 knl->kl_assert_unlocked = kl_assert_unlocked; 1978 1979 SLIST_INIT(&knl->kl_list); 1980 } 1981 1982 void 1983 knlist_init_mtx(struct knlist *knl, struct mtx *lock) 1984 { 1985 1986 knlist_init(knl, lock, NULL, NULL, NULL, NULL); 1987 } 1988 1989 void 1990 knlist_init_rw_reader(struct knlist *knl, struct rwlock *lock) 1991 { 1992 1993 knlist_init(knl, lock, knlist_rw_rlock, knlist_rw_runlock, 1994 knlist_rw_assert_locked, knlist_rw_assert_unlocked); 1995 } 1996 1997 void 1998 knlist_destroy(struct knlist *knl) 1999 { 2000 2001 #ifdef INVARIANTS 2002 /* 2003 * if we run across this error, we need to find the offending 2004 * driver and have it call knlist_clear. 2005 */ 2006 if (!SLIST_EMPTY(&knl->kl_list)) 2007 printf("WARNING: destroying knlist w/ knotes on it!\n"); 2008 #endif 2009 2010 knl->kl_lockarg = knl->kl_lock = knl->kl_unlock = NULL; 2011 SLIST_INIT(&knl->kl_list); 2012 } 2013 2014 /* 2015 * Even if we are locked, we may need to drop the lock to allow any influx 2016 * knotes time to "settle". 2017 */ 2018 void 2019 knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn) 2020 { 2021 struct knote *kn, *kn2; 2022 struct kqueue *kq; 2023 2024 if (islocked) 2025 KNL_ASSERT_LOCKED(knl); 2026 else { 2027 KNL_ASSERT_UNLOCKED(knl); 2028 again: /* need to reacquire lock since we have dropped it */ 2029 knl->kl_lock(knl->kl_lockarg); 2030 } 2031 2032 SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) { 2033 kq = kn->kn_kq; 2034 KQ_LOCK(kq); 2035 if ((kn->kn_status & KN_INFLUX)) { 2036 KQ_UNLOCK(kq); 2037 continue; 2038 } 2039 knlist_remove_kq(knl, kn, 1, 1); 2040 if (killkn) { 2041 kn->kn_status |= KN_INFLUX | KN_DETACHED; 2042 KQ_UNLOCK(kq); 2043 knote_drop(kn, td); 2044 } else { 2045 /* Make sure cleared knotes disappear soon */ 2046 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 2047 KQ_UNLOCK(kq); 2048 } 2049 kq = NULL; 2050 } 2051 2052 if (!SLIST_EMPTY(&knl->kl_list)) { 2053 /* there are still KN_INFLUX remaining */ 2054 kn = SLIST_FIRST(&knl->kl_list); 2055 kq = kn->kn_kq; 2056 KQ_LOCK(kq); 2057 KASSERT(kn->kn_status & KN_INFLUX, 2058 ("knote removed w/o list lock")); 2059 knl->kl_unlock(knl->kl_lockarg); 2060 kq->kq_state |= KQ_FLUXWAIT; 2061 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0); 2062 kq = NULL; 2063 goto again; 2064 } 2065 2066 if (islocked) 2067 KNL_ASSERT_LOCKED(knl); 2068 else { 2069 knl->kl_unlock(knl->kl_lockarg); 2070 KNL_ASSERT_UNLOCKED(knl); 2071 } 2072 } 2073 2074 /* 2075 * Remove all knotes referencing a specified fd must be called with FILEDESC 2076 * lock. This prevents a race where a new fd comes along and occupies the 2077 * entry and we attach a knote to the fd. 2078 */ 2079 void 2080 knote_fdclose(struct thread *td, int fd) 2081 { 2082 struct filedesc *fdp = td->td_proc->p_fd; 2083 struct kqueue *kq; 2084 struct knote *kn; 2085 int influx; 2086 2087 FILEDESC_XLOCK_ASSERT(fdp); 2088 2089 /* 2090 * We shouldn't have to worry about new kevents appearing on fd 2091 * since filedesc is locked. 2092 */ 2093 SLIST_FOREACH(kq, &fdp->fd_kqlist, kq_list) { 2094 KQ_LOCK(kq); 2095 2096 again: 2097 influx = 0; 2098 while (kq->kq_knlistsize > fd && 2099 (kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) { 2100 if (kn->kn_status & KN_INFLUX) { 2101 /* someone else might be waiting on our knote */ 2102 if (influx) 2103 wakeup(kq); 2104 kq->kq_state |= KQ_FLUXWAIT; 2105 msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0); 2106 goto again; 2107 } 2108 kn->kn_status |= KN_INFLUX; 2109 KQ_UNLOCK(kq); 2110 if (!(kn->kn_status & KN_DETACHED)) 2111 kn->kn_fop->f_detach(kn); 2112 knote_drop(kn, td); 2113 influx = 1; 2114 KQ_LOCK(kq); 2115 } 2116 KQ_UNLOCK_FLUX(kq); 2117 } 2118 } 2119 2120 static int 2121 knote_attach(struct knote *kn, struct kqueue *kq) 2122 { 2123 struct klist *list; 2124 2125 KASSERT(kn->kn_status & KN_INFLUX, ("knote not marked INFLUX")); 2126 KQ_OWNED(kq); 2127 2128 if (kn->kn_fop->f_isfd) { 2129 if (kn->kn_id >= kq->kq_knlistsize) 2130 return ENOMEM; 2131 list = &kq->kq_knlist[kn->kn_id]; 2132 } else { 2133 if (kq->kq_knhash == NULL) 2134 return ENOMEM; 2135 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2136 } 2137 2138 SLIST_INSERT_HEAD(list, kn, kn_link); 2139 2140 return 0; 2141 } 2142 2143 /* 2144 * knote must already have been detached using the f_detach method. 2145 * no lock need to be held, it is assumed that the KN_INFLUX flag is set 2146 * to prevent other removal. 2147 */ 2148 static void 2149 knote_drop(struct knote *kn, struct thread *td) 2150 { 2151 struct kqueue *kq; 2152 struct klist *list; 2153 2154 kq = kn->kn_kq; 2155 2156 KQ_NOTOWNED(kq); 2157 KASSERT((kn->kn_status & KN_INFLUX) == KN_INFLUX, 2158 ("knote_drop called without KN_INFLUX set in kn_status")); 2159 2160 KQ_LOCK(kq); 2161 if (kn->kn_fop->f_isfd) 2162 list = &kq->kq_knlist[kn->kn_id]; 2163 else 2164 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2165 2166 if (!SLIST_EMPTY(list)) 2167 SLIST_REMOVE(list, kn, knote, kn_link); 2168 if (kn->kn_status & KN_QUEUED) 2169 knote_dequeue(kn); 2170 KQ_UNLOCK_FLUX(kq); 2171 2172 if (kn->kn_fop->f_isfd) { 2173 fdrop(kn->kn_fp, td); 2174 kn->kn_fp = NULL; 2175 } 2176 kqueue_fo_release(kn->kn_kevent.filter); 2177 kn->kn_fop = NULL; 2178 knote_free(kn); 2179 } 2180 2181 static void 2182 knote_enqueue(struct knote *kn) 2183 { 2184 struct kqueue *kq = kn->kn_kq; 2185 2186 KQ_OWNED(kn->kn_kq); 2187 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 2188 2189 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2190 kn->kn_status |= KN_QUEUED; 2191 kq->kq_count++; 2192 kqueue_wakeup(kq); 2193 } 2194 2195 static void 2196 knote_dequeue(struct knote *kn) 2197 { 2198 struct kqueue *kq = kn->kn_kq; 2199 2200 KQ_OWNED(kn->kn_kq); 2201 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 2202 2203 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 2204 kn->kn_status &= ~KN_QUEUED; 2205 kq->kq_count--; 2206 } 2207 2208 static void 2209 knote_init(void) 2210 { 2211 2212 knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL, 2213 NULL, NULL, UMA_ALIGN_PTR, 0); 2214 } 2215 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL); 2216 2217 static struct knote * 2218 knote_alloc(int waitok) 2219 { 2220 return ((struct knote *)uma_zalloc(knote_zone, 2221 (waitok ? M_WAITOK : M_NOWAIT)|M_ZERO)); 2222 } 2223 2224 static void 2225 knote_free(struct knote *kn) 2226 { 2227 if (kn != NULL) 2228 uma_zfree(knote_zone, kn); 2229 } 2230 2231 /* 2232 * Register the kev w/ the kq specified by fd. 2233 */ 2234 int 2235 kqfd_register(int fd, struct kevent *kev, struct thread *td, int waitok) 2236 { 2237 struct kqueue *kq; 2238 struct file *fp; 2239 int error; 2240 2241 if ((error = fget(td, fd, CAP_POST_EVENT, &fp)) != 0) 2242 return (error); 2243 if ((error = kqueue_acquire(fp, &kq)) != 0) 2244 goto noacquire; 2245 2246 error = kqueue_register(kq, kev, td, waitok); 2247 2248 kqueue_release(kq, 0); 2249 2250 noacquire: 2251 fdrop(fp, td); 2252 2253 return error; 2254 } 2255