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/kernel.h> 37 #include <sys/lock.h> 38 #include <sys/mutex.h> 39 #include <sys/proc.h> 40 #include <sys/malloc.h> 41 #include <sys/unistd.h> 42 #include <sys/file.h> 43 #include <sys/filedesc.h> 44 #include <sys/filio.h> 45 #include <sys/fcntl.h> 46 #include <sys/kthread.h> 47 #include <sys/selinfo.h> 48 #include <sys/queue.h> 49 #include <sys/event.h> 50 #include <sys/eventvar.h> 51 #include <sys/poll.h> 52 #include <sys/protosw.h> 53 #include <sys/sigio.h> 54 #include <sys/signalvar.h> 55 #include <sys/socket.h> 56 #include <sys/socketvar.h> 57 #include <sys/stat.h> 58 #include <sys/sysctl.h> 59 #include <sys/sysproto.h> 60 #include <sys/syscallsubr.h> 61 #include <sys/taskqueue.h> 62 #include <sys/uio.h> 63 #ifdef KTRACE 64 #include <sys/ktrace.h> 65 #endif 66 67 #include <vm/uma.h> 68 69 static MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system"); 70 71 /* 72 * This lock is used if multiple kq locks are required. This possibly 73 * should be made into a per proc lock. 74 */ 75 static struct mtx kq_global; 76 MTX_SYSINIT(kq_global, &kq_global, "kqueue order", MTX_DEF); 77 #define KQ_GLOBAL_LOCK(lck, haslck) do { \ 78 if (!haslck) \ 79 mtx_lock(lck); \ 80 haslck = 1; \ 81 } while (0) 82 #define KQ_GLOBAL_UNLOCK(lck, haslck) do { \ 83 if (haslck) \ 84 mtx_unlock(lck); \ 85 haslck = 0; \ 86 } while (0) 87 88 TASKQUEUE_DEFINE_THREAD(kqueue); 89 90 static int kevent_copyout(void *arg, struct kevent *kevp, int count); 91 static int kevent_copyin(void *arg, struct kevent *kevp, int count); 92 static int kqueue_register(struct kqueue *kq, struct kevent *kev, 93 struct thread *td, int waitok); 94 static int kqueue_acquire(struct file *fp, struct kqueue **kqp); 95 static void kqueue_release(struct kqueue *kq, int locked); 96 static int kqueue_expand(struct kqueue *kq, struct filterops *fops, 97 uintptr_t ident, int waitok); 98 static void kqueue_task(void *arg, int pending); 99 static int kqueue_scan(struct kqueue *kq, int maxevents, 100 struct kevent_copyops *k_ops, 101 const struct timespec *timeout, 102 struct kevent *keva, struct thread *td); 103 static void kqueue_wakeup(struct kqueue *kq); 104 static struct filterops *kqueue_fo_find(int filt); 105 static void kqueue_fo_release(int filt); 106 107 static fo_rdwr_t kqueue_read; 108 static fo_rdwr_t kqueue_write; 109 static fo_truncate_t kqueue_truncate; 110 static fo_ioctl_t kqueue_ioctl; 111 static fo_poll_t kqueue_poll; 112 static fo_kqfilter_t kqueue_kqfilter; 113 static fo_stat_t kqueue_stat; 114 static fo_close_t kqueue_close; 115 116 static struct fileops kqueueops = { 117 .fo_read = kqueue_read, 118 .fo_write = kqueue_write, 119 .fo_truncate = kqueue_truncate, 120 .fo_ioctl = kqueue_ioctl, 121 .fo_poll = kqueue_poll, 122 .fo_kqfilter = kqueue_kqfilter, 123 .fo_stat = kqueue_stat, 124 .fo_close = kqueue_close, 125 }; 126 127 static int knote_attach(struct knote *kn, struct kqueue *kq); 128 static void knote_drop(struct knote *kn, struct thread *td); 129 static void knote_enqueue(struct knote *kn); 130 static void knote_dequeue(struct knote *kn); 131 static void knote_init(void); 132 static struct knote *knote_alloc(int waitok); 133 static void knote_free(struct knote *kn); 134 135 static void filt_kqdetach(struct knote *kn); 136 static int filt_kqueue(struct knote *kn, long hint); 137 static int filt_procattach(struct knote *kn); 138 static void filt_procdetach(struct knote *kn); 139 static int filt_proc(struct knote *kn, long hint); 140 static int filt_fileattach(struct knote *kn); 141 static void filt_timerexpire(void *knx); 142 static int filt_timerattach(struct knote *kn); 143 static void filt_timerdetach(struct knote *kn); 144 static int filt_timer(struct knote *kn, long hint); 145 static int filt_userattach(struct knote *kn); 146 static void filt_userdetach(struct knote *kn); 147 static int filt_user(struct knote *kn, long hint); 148 static void filt_usertouch(struct knote *kn, struct kevent *kev, 149 u_long type); 150 151 static struct filterops file_filtops = { 152 .f_isfd = 1, 153 .f_attach = filt_fileattach, 154 }; 155 static struct filterops kqread_filtops = { 156 .f_isfd = 1, 157 .f_detach = filt_kqdetach, 158 .f_event = filt_kqueue, 159 }; 160 /* XXX - move to kern_proc.c? */ 161 static struct filterops proc_filtops = { 162 .f_isfd = 0, 163 .f_attach = filt_procattach, 164 .f_detach = filt_procdetach, 165 .f_event = filt_proc, 166 }; 167 static struct filterops timer_filtops = { 168 .f_isfd = 0, 169 .f_attach = filt_timerattach, 170 .f_detach = filt_timerdetach, 171 .f_event = filt_timer, 172 }; 173 static struct filterops user_filtops = { 174 .f_attach = filt_userattach, 175 .f_detach = filt_userdetach, 176 .f_event = filt_user, 177 .f_touch = filt_usertouch, 178 }; 179 180 static uma_zone_t knote_zone; 181 static int kq_ncallouts = 0; 182 static int kq_calloutmax = (4 * 1024); 183 SYSCTL_INT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW, 184 &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue"); 185 186 /* XXX - ensure not KN_INFLUX?? */ 187 #define KNOTE_ACTIVATE(kn, islock) do { \ 188 if ((islock)) \ 189 mtx_assert(&(kn)->kn_kq->kq_lock, MA_OWNED); \ 190 else \ 191 KQ_LOCK((kn)->kn_kq); \ 192 (kn)->kn_status |= KN_ACTIVE; \ 193 if (((kn)->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 194 knote_enqueue((kn)); \ 195 if (!(islock)) \ 196 KQ_UNLOCK((kn)->kn_kq); \ 197 } while(0) 198 #define KQ_LOCK(kq) do { \ 199 mtx_lock(&(kq)->kq_lock); \ 200 } while (0) 201 #define KQ_FLUX_WAKEUP(kq) do { \ 202 if (((kq)->kq_state & KQ_FLUXWAIT) == KQ_FLUXWAIT) { \ 203 (kq)->kq_state &= ~KQ_FLUXWAIT; \ 204 wakeup((kq)); \ 205 } \ 206 } while (0) 207 #define KQ_UNLOCK_FLUX(kq) do { \ 208 KQ_FLUX_WAKEUP(kq); \ 209 mtx_unlock(&(kq)->kq_lock); \ 210 } while (0) 211 #define KQ_UNLOCK(kq) do { \ 212 mtx_unlock(&(kq)->kq_lock); \ 213 } while (0) 214 #define KQ_OWNED(kq) do { \ 215 mtx_assert(&(kq)->kq_lock, MA_OWNED); \ 216 } while (0) 217 #define KQ_NOTOWNED(kq) do { \ 218 mtx_assert(&(kq)->kq_lock, MA_NOTOWNED); \ 219 } while (0) 220 #define KN_LIST_LOCK(kn) do { \ 221 if (kn->kn_knlist != NULL) \ 222 kn->kn_knlist->kl_lock(kn->kn_knlist->kl_lockarg); \ 223 } while (0) 224 #define KN_LIST_UNLOCK(kn) do { \ 225 if (kn->kn_knlist != NULL) \ 226 kn->kn_knlist->kl_unlock(kn->kn_knlist->kl_lockarg); \ 227 } while (0) 228 #define KNL_ASSERT_LOCK(knl, islocked) do { \ 229 if (islocked) \ 230 KNL_ASSERT_LOCKED(knl); \ 231 else \ 232 KNL_ASSERT_UNLOCKED(knl); \ 233 } while (0) 234 #ifdef INVARIANTS 235 #define KNL_ASSERT_LOCKED(knl) do { \ 236 knl->kl_assert_locked((knl)->kl_lockarg); \ 237 } while (0) 238 #define KNL_ASSERT_UNLOCKED(knl) do { \ 239 knl->kl_assert_unlocked((knl)->kl_lockarg); \ 240 } while (0) 241 #else /* !INVARIANTS */ 242 #define KNL_ASSERT_LOCKED(knl) do {} while(0) 243 #define KNL_ASSERT_UNLOCKED(knl) do {} while (0) 244 #endif /* INVARIANTS */ 245 246 #define KN_HASHSIZE 64 /* XXX should be tunable */ 247 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 248 249 static int 250 filt_nullattach(struct knote *kn) 251 { 252 253 return (ENXIO); 254 }; 255 256 struct filterops null_filtops = { 257 .f_isfd = 0, 258 .f_attach = filt_nullattach, 259 }; 260 261 /* XXX - make SYSINIT to add these, and move into respective modules. */ 262 extern struct filterops sig_filtops; 263 extern struct filterops fs_filtops; 264 265 /* 266 * Table for for all system-defined filters. 267 */ 268 static struct mtx filterops_lock; 269 MTX_SYSINIT(kqueue_filterops, &filterops_lock, "protect sysfilt_ops", 270 MTX_DEF); 271 static struct { 272 struct filterops *for_fop; 273 int for_refcnt; 274 } sysfilt_ops[EVFILT_SYSCOUNT] = { 275 { &file_filtops }, /* EVFILT_READ */ 276 { &file_filtops }, /* EVFILT_WRITE */ 277 { &null_filtops }, /* EVFILT_AIO */ 278 { &file_filtops }, /* EVFILT_VNODE */ 279 { &proc_filtops }, /* EVFILT_PROC */ 280 { &sig_filtops }, /* EVFILT_SIGNAL */ 281 { &timer_filtops }, /* EVFILT_TIMER */ 282 { &null_filtops }, /* former EVFILT_NETDEV */ 283 { &fs_filtops }, /* EVFILT_FS */ 284 { &null_filtops }, /* EVFILT_LIO */ 285 { &user_filtops }, /* EVFILT_USER */ 286 }; 287 288 /* 289 * Simple redirection for all cdevsw style objects to call their fo_kqfilter 290 * method. 291 */ 292 static int 293 filt_fileattach(struct knote *kn) 294 { 295 296 return (fo_kqfilter(kn->kn_fp, kn)); 297 } 298 299 /*ARGSUSED*/ 300 static int 301 kqueue_kqfilter(struct file *fp, struct knote *kn) 302 { 303 struct kqueue *kq = kn->kn_fp->f_data; 304 305 if (kn->kn_filter != EVFILT_READ) 306 return (EINVAL); 307 308 kn->kn_status |= KN_KQUEUE; 309 kn->kn_fop = &kqread_filtops; 310 knlist_add(&kq->kq_sel.si_note, kn, 0); 311 312 return (0); 313 } 314 315 static void 316 filt_kqdetach(struct knote *kn) 317 { 318 struct kqueue *kq = kn->kn_fp->f_data; 319 320 knlist_remove(&kq->kq_sel.si_note, kn, 0); 321 } 322 323 /*ARGSUSED*/ 324 static int 325 filt_kqueue(struct knote *kn, long hint) 326 { 327 struct kqueue *kq = kn->kn_fp->f_data; 328 329 kn->kn_data = kq->kq_count; 330 return (kn->kn_data > 0); 331 } 332 333 /* XXX - move to kern_proc.c? */ 334 static int 335 filt_procattach(struct knote *kn) 336 { 337 struct proc *p; 338 int immediate; 339 int error; 340 341 immediate = 0; 342 p = pfind(kn->kn_id); 343 if (p == NULL && (kn->kn_sfflags & NOTE_EXIT)) { 344 p = zpfind(kn->kn_id); 345 immediate = 1; 346 } else if (p != NULL && (p->p_flag & P_WEXIT)) { 347 immediate = 1; 348 } 349 350 if (p == NULL) 351 return (ESRCH); 352 if ((error = p_cansee(curthread, p))) { 353 PROC_UNLOCK(p); 354 return (error); 355 } 356 357 kn->kn_ptr.p_proc = p; 358 kn->kn_flags |= EV_CLEAR; /* automatically set */ 359 360 /* 361 * internal flag indicating registration done by kernel 362 */ 363 if (kn->kn_flags & EV_FLAG1) { 364 kn->kn_data = kn->kn_sdata; /* ppid */ 365 kn->kn_fflags = NOTE_CHILD; 366 kn->kn_flags &= ~EV_FLAG1; 367 } 368 369 if (immediate == 0) 370 knlist_add(&p->p_klist, kn, 1); 371 372 /* 373 * Immediately activate any exit notes if the target process is a 374 * zombie. This is necessary to handle the case where the target 375 * process, e.g. a child, dies before the kevent is registered. 376 */ 377 if (immediate && filt_proc(kn, NOTE_EXIT)) 378 KNOTE_ACTIVATE(kn, 0); 379 380 PROC_UNLOCK(p); 381 382 return (0); 383 } 384 385 /* 386 * The knote may be attached to a different process, which may exit, 387 * leaving nothing for the knote to be attached to. So when the process 388 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 389 * it will be deleted when read out. However, as part of the knote deletion, 390 * this routine is called, so a check is needed to avoid actually performing 391 * a detach, because the original process does not exist any more. 392 */ 393 /* XXX - move to kern_proc.c? */ 394 static void 395 filt_procdetach(struct knote *kn) 396 { 397 struct proc *p; 398 399 p = kn->kn_ptr.p_proc; 400 knlist_remove(&p->p_klist, kn, 0); 401 kn->kn_ptr.p_proc = NULL; 402 } 403 404 /* XXX - move to kern_proc.c? */ 405 static int 406 filt_proc(struct knote *kn, long hint) 407 { 408 struct proc *p = kn->kn_ptr.p_proc; 409 u_int event; 410 411 /* 412 * mask off extra data 413 */ 414 event = (u_int)hint & NOTE_PCTRLMASK; 415 416 /* 417 * if the user is interested in this event, record it. 418 */ 419 if (kn->kn_sfflags & event) 420 kn->kn_fflags |= event; 421 422 /* 423 * process is gone, so flag the event as finished. 424 */ 425 if (event == NOTE_EXIT) { 426 if (!(kn->kn_status & KN_DETACHED)) 427 knlist_remove_inevent(&p->p_klist, kn); 428 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 429 kn->kn_data = p->p_xstat; 430 kn->kn_ptr.p_proc = NULL; 431 return (1); 432 } 433 434 return (kn->kn_fflags != 0); 435 } 436 437 /* 438 * Called when the process forked. It mostly does the same as the 439 * knote(), activating all knotes registered to be activated when the 440 * process forked. Additionally, for each knote attached to the 441 * parent, check whether user wants to track the new process. If so 442 * attach a new knote to it, and immediately report an event with the 443 * child's pid. 444 */ 445 void 446 knote_fork(struct knlist *list, int pid) 447 { 448 struct kqueue *kq; 449 struct knote *kn; 450 struct kevent kev; 451 int error; 452 453 if (list == NULL) 454 return; 455 list->kl_lock(list->kl_lockarg); 456 457 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { 458 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) 459 continue; 460 kq = kn->kn_kq; 461 KQ_LOCK(kq); 462 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 463 KQ_UNLOCK(kq); 464 continue; 465 } 466 467 /* 468 * The same as knote(), activate the event. 469 */ 470 if ((kn->kn_sfflags & NOTE_TRACK) == 0) { 471 kn->kn_status |= KN_HASKQLOCK; 472 if (kn->kn_fop->f_event(kn, NOTE_FORK | pid)) 473 KNOTE_ACTIVATE(kn, 1); 474 kn->kn_status &= ~KN_HASKQLOCK; 475 KQ_UNLOCK(kq); 476 continue; 477 } 478 479 /* 480 * The NOTE_TRACK case. In addition to the activation 481 * of the event, we need to register new event to 482 * track the child. Drop the locks in preparation for 483 * the call to kqueue_register(). 484 */ 485 kn->kn_status |= KN_INFLUX; 486 KQ_UNLOCK(kq); 487 list->kl_unlock(list->kl_lockarg); 488 489 /* 490 * Activate existing knote and register a knote with 491 * new process. 492 */ 493 kev.ident = pid; 494 kev.filter = kn->kn_filter; 495 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 496 kev.fflags = kn->kn_sfflags; 497 kev.data = kn->kn_id; /* parent */ 498 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 499 error = kqueue_register(kq, &kev, NULL, 0); 500 if (kn->kn_fop->f_event(kn, NOTE_FORK | pid)) 501 KNOTE_ACTIVATE(kn, 0); 502 if (error) 503 kn->kn_fflags |= NOTE_TRACKERR; 504 KQ_LOCK(kq); 505 kn->kn_status &= ~KN_INFLUX; 506 KQ_UNLOCK_FLUX(kq); 507 list->kl_lock(list->kl_lockarg); 508 } 509 list->kl_unlock(list->kl_lockarg); 510 } 511 512 static int 513 timertoticks(intptr_t data) 514 { 515 struct timeval tv; 516 int tticks; 517 518 tv.tv_sec = data / 1000; 519 tv.tv_usec = (data % 1000) * 1000; 520 tticks = tvtohz(&tv); 521 522 return tticks; 523 } 524 525 /* XXX - move to kern_timeout.c? */ 526 static void 527 filt_timerexpire(void *knx) 528 { 529 struct knote *kn = knx; 530 struct callout *calloutp; 531 532 kn->kn_data++; 533 KNOTE_ACTIVATE(kn, 0); /* XXX - handle locking */ 534 535 if ((kn->kn_flags & EV_ONESHOT) != EV_ONESHOT) { 536 calloutp = (struct callout *)kn->kn_hook; 537 callout_reset_curcpu(calloutp, timertoticks(kn->kn_sdata), 538 filt_timerexpire, kn); 539 } 540 } 541 542 /* 543 * data contains amount of time to sleep, in milliseconds 544 */ 545 /* XXX - move to kern_timeout.c? */ 546 static int 547 filt_timerattach(struct knote *kn) 548 { 549 struct callout *calloutp; 550 551 atomic_add_int(&kq_ncallouts, 1); 552 553 if (kq_ncallouts >= kq_calloutmax) { 554 atomic_add_int(&kq_ncallouts, -1); 555 return (ENOMEM); 556 } 557 558 kn->kn_flags |= EV_CLEAR; /* automatically set */ 559 kn->kn_status &= ~KN_DETACHED; /* knlist_add usually sets it */ 560 calloutp = malloc(sizeof(*calloutp), M_KQUEUE, M_WAITOK); 561 callout_init(calloutp, CALLOUT_MPSAFE); 562 kn->kn_hook = calloutp; 563 callout_reset_curcpu(calloutp, timertoticks(kn->kn_sdata), 564 filt_timerexpire, kn); 565 566 return (0); 567 } 568 569 /* XXX - move to kern_timeout.c? */ 570 static void 571 filt_timerdetach(struct knote *kn) 572 { 573 struct callout *calloutp; 574 575 calloutp = (struct callout *)kn->kn_hook; 576 callout_drain(calloutp); 577 free(calloutp, M_KQUEUE); 578 atomic_add_int(&kq_ncallouts, -1); 579 kn->kn_status |= KN_DETACHED; /* knlist_remove usually clears it */ 580 } 581 582 /* XXX - move to kern_timeout.c? */ 583 static int 584 filt_timer(struct knote *kn, long hint) 585 { 586 587 return (kn->kn_data != 0); 588 } 589 590 static int 591 filt_userattach(struct knote *kn) 592 { 593 594 /* 595 * EVFILT_USER knotes are not attached to anything in the kernel. 596 */ 597 kn->kn_hook = NULL; 598 if (kn->kn_fflags & NOTE_TRIGGER) 599 kn->kn_hookid = 1; 600 else 601 kn->kn_hookid = 0; 602 return (0); 603 } 604 605 static void 606 filt_userdetach(__unused struct knote *kn) 607 { 608 609 /* 610 * EVFILT_USER knotes are not attached to anything in the kernel. 611 */ 612 } 613 614 static int 615 filt_user(struct knote *kn, __unused long hint) 616 { 617 618 return (kn->kn_hookid); 619 } 620 621 static void 622 filt_usertouch(struct knote *kn, struct kevent *kev, u_long type) 623 { 624 u_int ffctrl; 625 626 switch (type) { 627 case EVENT_REGISTER: 628 if (kev->fflags & NOTE_TRIGGER) 629 kn->kn_hookid = 1; 630 631 ffctrl = kev->fflags & NOTE_FFCTRLMASK; 632 kev->fflags &= NOTE_FFLAGSMASK; 633 switch (ffctrl) { 634 case NOTE_FFNOP: 635 break; 636 637 case NOTE_FFAND: 638 kn->kn_sfflags &= kev->fflags; 639 break; 640 641 case NOTE_FFOR: 642 kn->kn_sfflags |= kev->fflags; 643 break; 644 645 case NOTE_FFCOPY: 646 kn->kn_sfflags = kev->fflags; 647 break; 648 649 default: 650 /* XXX Return error? */ 651 break; 652 } 653 kn->kn_sdata = kev->data; 654 if (kev->flags & EV_CLEAR) { 655 kn->kn_hookid = 0; 656 kn->kn_data = 0; 657 kn->kn_fflags = 0; 658 } 659 break; 660 661 case EVENT_PROCESS: 662 *kev = kn->kn_kevent; 663 kev->fflags = kn->kn_sfflags; 664 kev->data = kn->kn_sdata; 665 if (kn->kn_flags & EV_CLEAR) { 666 kn->kn_hookid = 0; 667 kn->kn_data = 0; 668 kn->kn_fflags = 0; 669 } 670 break; 671 672 default: 673 panic("filt_usertouch() - invalid type (%ld)", type); 674 break; 675 } 676 } 677 678 int 679 kqueue(struct thread *td, struct kqueue_args *uap) 680 { 681 struct filedesc *fdp; 682 struct kqueue *kq; 683 struct file *fp; 684 int fd, error; 685 686 fdp = td->td_proc->p_fd; 687 error = falloc(td, &fp, &fd, 0); 688 if (error) 689 goto done2; 690 691 /* An extra reference on `nfp' has been held for us by falloc(). */ 692 kq = malloc(sizeof *kq, M_KQUEUE, M_WAITOK | M_ZERO); 693 mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF|MTX_DUPOK); 694 TAILQ_INIT(&kq->kq_head); 695 kq->kq_fdp = fdp; 696 knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock); 697 TASK_INIT(&kq->kq_task, 0, kqueue_task, kq); 698 699 FILEDESC_XLOCK(fdp); 700 SLIST_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list); 701 FILEDESC_XUNLOCK(fdp); 702 703 finit(fp, FREAD | FWRITE, DTYPE_KQUEUE, kq, &kqueueops); 704 fdrop(fp, td); 705 706 td->td_retval[0] = fd; 707 done2: 708 return (error); 709 } 710 711 #ifndef _SYS_SYSPROTO_H_ 712 struct kevent_args { 713 int fd; 714 const struct kevent *changelist; 715 int nchanges; 716 struct kevent *eventlist; 717 int nevents; 718 const struct timespec *timeout; 719 }; 720 #endif 721 int 722 kevent(struct thread *td, struct kevent_args *uap) 723 { 724 struct timespec ts, *tsp; 725 struct kevent_copyops k_ops = { uap, 726 kevent_copyout, 727 kevent_copyin}; 728 int error; 729 #ifdef KTRACE 730 struct uio ktruio; 731 struct iovec ktriov; 732 struct uio *ktruioin = NULL; 733 struct uio *ktruioout = NULL; 734 #endif 735 736 if (uap->timeout != NULL) { 737 error = copyin(uap->timeout, &ts, sizeof(ts)); 738 if (error) 739 return (error); 740 tsp = &ts; 741 } else 742 tsp = NULL; 743 744 #ifdef KTRACE 745 if (KTRPOINT(td, KTR_GENIO)) { 746 ktriov.iov_base = uap->changelist; 747 ktriov.iov_len = uap->nchanges * sizeof(struct kevent); 748 ktruio = (struct uio){ .uio_iov = &ktriov, .uio_iovcnt = 1, 749 .uio_segflg = UIO_USERSPACE, .uio_rw = UIO_READ, 750 .uio_td = td }; 751 ktruioin = cloneuio(&ktruio); 752 ktriov.iov_base = uap->eventlist; 753 ktriov.iov_len = uap->nevents * sizeof(struct kevent); 754 ktruioout = cloneuio(&ktruio); 755 } 756 #endif 757 758 error = kern_kevent(td, uap->fd, uap->nchanges, uap->nevents, 759 &k_ops, tsp); 760 761 #ifdef KTRACE 762 if (ktruioin != NULL) { 763 ktruioin->uio_resid = uap->nchanges * sizeof(struct kevent); 764 ktrgenio(uap->fd, UIO_WRITE, ktruioin, 0); 765 ktruioout->uio_resid = td->td_retval[0] * sizeof(struct kevent); 766 ktrgenio(uap->fd, UIO_READ, ktruioout, error); 767 } 768 #endif 769 770 return (error); 771 } 772 773 /* 774 * Copy 'count' items into the destination list pointed to by uap->eventlist. 775 */ 776 static int 777 kevent_copyout(void *arg, struct kevent *kevp, int count) 778 { 779 struct kevent_args *uap; 780 int error; 781 782 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 783 uap = (struct kevent_args *)arg; 784 785 error = copyout(kevp, uap->eventlist, count * sizeof *kevp); 786 if (error == 0) 787 uap->eventlist += count; 788 return (error); 789 } 790 791 /* 792 * Copy 'count' items from the list pointed to by uap->changelist. 793 */ 794 static int 795 kevent_copyin(void *arg, struct kevent *kevp, int count) 796 { 797 struct kevent_args *uap; 798 int error; 799 800 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 801 uap = (struct kevent_args *)arg; 802 803 error = copyin(uap->changelist, kevp, count * sizeof *kevp); 804 if (error == 0) 805 uap->changelist += count; 806 return (error); 807 } 808 809 int 810 kern_kevent(struct thread *td, int fd, int nchanges, int nevents, 811 struct kevent_copyops *k_ops, const struct timespec *timeout) 812 { 813 struct kevent keva[KQ_NEVENTS]; 814 struct kevent *kevp, *changes; 815 struct kqueue *kq; 816 struct file *fp; 817 int i, n, nerrors, error; 818 819 if ((error = fget(td, fd, &fp)) != 0) 820 return (error); 821 if ((error = kqueue_acquire(fp, &kq)) != 0) 822 goto done_norel; 823 824 nerrors = 0; 825 826 while (nchanges > 0) { 827 n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges; 828 error = k_ops->k_copyin(k_ops->arg, keva, n); 829 if (error) 830 goto done; 831 changes = keva; 832 for (i = 0; i < n; i++) { 833 kevp = &changes[i]; 834 if (!kevp->filter) 835 continue; 836 kevp->flags &= ~EV_SYSFLAGS; 837 error = kqueue_register(kq, kevp, td, 1); 838 if (error || (kevp->flags & EV_RECEIPT)) { 839 if (nevents != 0) { 840 kevp->flags = EV_ERROR; 841 kevp->data = error; 842 (void) k_ops->k_copyout(k_ops->arg, 843 kevp, 1); 844 nevents--; 845 nerrors++; 846 } else { 847 goto done; 848 } 849 } 850 } 851 nchanges -= n; 852 } 853 if (nerrors) { 854 td->td_retval[0] = nerrors; 855 error = 0; 856 goto done; 857 } 858 859 error = kqueue_scan(kq, nevents, k_ops, timeout, keva, td); 860 done: 861 kqueue_release(kq, 0); 862 done_norel: 863 fdrop(fp, td); 864 return (error); 865 } 866 867 int 868 kqueue_add_filteropts(int filt, struct filterops *filtops) 869 { 870 int error; 871 872 error = 0; 873 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) { 874 printf( 875 "trying to add a filterop that is out of range: %d is beyond %d\n", 876 ~filt, EVFILT_SYSCOUNT); 877 return EINVAL; 878 } 879 mtx_lock(&filterops_lock); 880 if (sysfilt_ops[~filt].for_fop != &null_filtops && 881 sysfilt_ops[~filt].for_fop != NULL) 882 error = EEXIST; 883 else { 884 sysfilt_ops[~filt].for_fop = filtops; 885 sysfilt_ops[~filt].for_refcnt = 0; 886 } 887 mtx_unlock(&filterops_lock); 888 889 return (error); 890 } 891 892 int 893 kqueue_del_filteropts(int filt) 894 { 895 int error; 896 897 error = 0; 898 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 899 return EINVAL; 900 901 mtx_lock(&filterops_lock); 902 if (sysfilt_ops[~filt].for_fop == &null_filtops || 903 sysfilt_ops[~filt].for_fop == NULL) 904 error = EINVAL; 905 else if (sysfilt_ops[~filt].for_refcnt != 0) 906 error = EBUSY; 907 else { 908 sysfilt_ops[~filt].for_fop = &null_filtops; 909 sysfilt_ops[~filt].for_refcnt = 0; 910 } 911 mtx_unlock(&filterops_lock); 912 913 return error; 914 } 915 916 static struct filterops * 917 kqueue_fo_find(int filt) 918 { 919 920 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 921 return NULL; 922 923 mtx_lock(&filterops_lock); 924 sysfilt_ops[~filt].for_refcnt++; 925 if (sysfilt_ops[~filt].for_fop == NULL) 926 sysfilt_ops[~filt].for_fop = &null_filtops; 927 mtx_unlock(&filterops_lock); 928 929 return sysfilt_ops[~filt].for_fop; 930 } 931 932 static void 933 kqueue_fo_release(int filt) 934 { 935 936 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 937 return; 938 939 mtx_lock(&filterops_lock); 940 KASSERT(sysfilt_ops[~filt].for_refcnt > 0, 941 ("filter object refcount not valid on release")); 942 sysfilt_ops[~filt].for_refcnt--; 943 mtx_unlock(&filterops_lock); 944 } 945 946 /* 947 * A ref to kq (obtained via kqueue_acquire) must be held. waitok will 948 * influence if memory allocation should wait. Make sure it is 0 if you 949 * hold any mutexes. 950 */ 951 static int 952 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, int waitok) 953 { 954 struct filterops *fops; 955 struct file *fp; 956 struct knote *kn, *tkn; 957 int error, filt, event; 958 int haskqglobal; 959 960 fp = NULL; 961 kn = NULL; 962 error = 0; 963 haskqglobal = 0; 964 965 filt = kev->filter; 966 fops = kqueue_fo_find(filt); 967 if (fops == NULL) 968 return EINVAL; 969 970 tkn = knote_alloc(waitok); /* prevent waiting with locks */ 971 972 findkn: 973 if (fops->f_isfd) { 974 KASSERT(td != NULL, ("td is NULL")); 975 error = fget(td, kev->ident, &fp); 976 if (error) 977 goto done; 978 979 if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops, 980 kev->ident, 0) != 0) { 981 /* try again */ 982 fdrop(fp, td); 983 fp = NULL; 984 error = kqueue_expand(kq, fops, kev->ident, waitok); 985 if (error) 986 goto done; 987 goto findkn; 988 } 989 990 if (fp->f_type == DTYPE_KQUEUE) { 991 /* 992 * if we add some inteligence about what we are doing, 993 * we should be able to support events on ourselves. 994 * We need to know when we are doing this to prevent 995 * getting both the knlist lock and the kq lock since 996 * they are the same thing. 997 */ 998 if (fp->f_data == kq) { 999 error = EINVAL; 1000 goto done; 1001 } 1002 1003 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1004 } 1005 1006 KQ_LOCK(kq); 1007 if (kev->ident < kq->kq_knlistsize) { 1008 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link) 1009 if (kev->filter == kn->kn_filter) 1010 break; 1011 } 1012 } else { 1013 if ((kev->flags & EV_ADD) == EV_ADD) 1014 kqueue_expand(kq, fops, kev->ident, waitok); 1015 1016 KQ_LOCK(kq); 1017 if (kq->kq_knhashmask != 0) { 1018 struct klist *list; 1019 1020 list = &kq->kq_knhash[ 1021 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)]; 1022 SLIST_FOREACH(kn, list, kn_link) 1023 if (kev->ident == kn->kn_id && 1024 kev->filter == kn->kn_filter) 1025 break; 1026 } 1027 } 1028 1029 /* knote is in the process of changing, wait for it to stablize. */ 1030 if (kn != NULL && (kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1031 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1032 kq->kq_state |= KQ_FLUXWAIT; 1033 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0); 1034 if (fp != NULL) { 1035 fdrop(fp, td); 1036 fp = NULL; 1037 } 1038 goto findkn; 1039 } 1040 1041 /* 1042 * kn now contains the matching knote, or NULL if no match 1043 */ 1044 if (kn == NULL) { 1045 if (kev->flags & EV_ADD) { 1046 kn = tkn; 1047 tkn = NULL; 1048 if (kn == NULL) { 1049 KQ_UNLOCK(kq); 1050 error = ENOMEM; 1051 goto done; 1052 } 1053 kn->kn_fp = fp; 1054 kn->kn_kq = kq; 1055 kn->kn_fop = fops; 1056 /* 1057 * apply reference counts to knote structure, and 1058 * do not release it at the end of this routine. 1059 */ 1060 fops = NULL; 1061 fp = NULL; 1062 1063 kn->kn_sfflags = kev->fflags; 1064 kn->kn_sdata = kev->data; 1065 kev->fflags = 0; 1066 kev->data = 0; 1067 kn->kn_kevent = *kev; 1068 kn->kn_kevent.flags &= ~(EV_ADD | EV_DELETE | 1069 EV_ENABLE | EV_DISABLE); 1070 kn->kn_status = KN_INFLUX|KN_DETACHED; 1071 1072 error = knote_attach(kn, kq); 1073 KQ_UNLOCK(kq); 1074 if (error != 0) { 1075 tkn = kn; 1076 goto done; 1077 } 1078 1079 if ((error = kn->kn_fop->f_attach(kn)) != 0) { 1080 knote_drop(kn, td); 1081 goto done; 1082 } 1083 KN_LIST_LOCK(kn); 1084 goto done_ev_add; 1085 } else { 1086 /* No matching knote and the EV_ADD flag is not set. */ 1087 KQ_UNLOCK(kq); 1088 error = ENOENT; 1089 goto done; 1090 } 1091 } 1092 1093 if (kev->flags & EV_DELETE) { 1094 kn->kn_status |= KN_INFLUX; 1095 KQ_UNLOCK(kq); 1096 if (!(kn->kn_status & KN_DETACHED)) 1097 kn->kn_fop->f_detach(kn); 1098 knote_drop(kn, td); 1099 goto done; 1100 } 1101 1102 /* 1103 * The user may change some filter values after the initial EV_ADD, 1104 * but doing so will not reset any filter which has already been 1105 * triggered. 1106 */ 1107 kn->kn_status |= KN_INFLUX; 1108 KQ_UNLOCK(kq); 1109 KN_LIST_LOCK(kn); 1110 kn->kn_kevent.udata = kev->udata; 1111 if (!fops->f_isfd && fops->f_touch != NULL) { 1112 fops->f_touch(kn, kev, EVENT_REGISTER); 1113 } else { 1114 kn->kn_sfflags = kev->fflags; 1115 kn->kn_sdata = kev->data; 1116 } 1117 1118 /* 1119 * We can get here with kn->kn_knlist == NULL. This can happen when 1120 * the initial attach event decides that the event is "completed" 1121 * already. i.e. filt_procattach is called on a zombie process. It 1122 * will call filt_proc which will remove it from the list, and NULL 1123 * kn_knlist. 1124 */ 1125 done_ev_add: 1126 event = kn->kn_fop->f_event(kn, 0); 1127 KQ_LOCK(kq); 1128 if (event) 1129 KNOTE_ACTIVATE(kn, 1); 1130 kn->kn_status &= ~KN_INFLUX; 1131 KN_LIST_UNLOCK(kn); 1132 1133 if ((kev->flags & EV_DISABLE) && 1134 ((kn->kn_status & KN_DISABLED) == 0)) { 1135 kn->kn_status |= KN_DISABLED; 1136 } 1137 1138 if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) { 1139 kn->kn_status &= ~KN_DISABLED; 1140 if ((kn->kn_status & KN_ACTIVE) && 1141 ((kn->kn_status & KN_QUEUED) == 0)) 1142 knote_enqueue(kn); 1143 } 1144 KQ_UNLOCK_FLUX(kq); 1145 1146 done: 1147 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1148 if (fp != NULL) 1149 fdrop(fp, td); 1150 if (tkn != NULL) 1151 knote_free(tkn); 1152 if (fops != NULL) 1153 kqueue_fo_release(filt); 1154 return (error); 1155 } 1156 1157 static int 1158 kqueue_acquire(struct file *fp, struct kqueue **kqp) 1159 { 1160 int error; 1161 struct kqueue *kq; 1162 1163 error = 0; 1164 1165 kq = fp->f_data; 1166 if (fp->f_type != DTYPE_KQUEUE || kq == NULL) 1167 return (EBADF); 1168 *kqp = kq; 1169 KQ_LOCK(kq); 1170 if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) { 1171 KQ_UNLOCK(kq); 1172 return (EBADF); 1173 } 1174 kq->kq_refcnt++; 1175 KQ_UNLOCK(kq); 1176 1177 return error; 1178 } 1179 1180 static void 1181 kqueue_release(struct kqueue *kq, int locked) 1182 { 1183 if (locked) 1184 KQ_OWNED(kq); 1185 else 1186 KQ_LOCK(kq); 1187 kq->kq_refcnt--; 1188 if (kq->kq_refcnt == 1) 1189 wakeup(&kq->kq_refcnt); 1190 if (!locked) 1191 KQ_UNLOCK(kq); 1192 } 1193 1194 static void 1195 kqueue_schedtask(struct kqueue *kq) 1196 { 1197 1198 KQ_OWNED(kq); 1199 KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN), 1200 ("scheduling kqueue task while draining")); 1201 1202 if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) { 1203 taskqueue_enqueue(taskqueue_kqueue, &kq->kq_task); 1204 kq->kq_state |= KQ_TASKSCHED; 1205 } 1206 } 1207 1208 /* 1209 * Expand the kq to make sure we have storage for fops/ident pair. 1210 * 1211 * Return 0 on success (or no work necessary), return errno on failure. 1212 * 1213 * Not calling hashinit w/ waitok (proper malloc flag) should be safe. 1214 * If kqueue_register is called from a non-fd context, there usually/should 1215 * be no locks held. 1216 */ 1217 static int 1218 kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident, 1219 int waitok) 1220 { 1221 struct klist *list, *tmp_knhash, *to_free; 1222 u_long tmp_knhashmask; 1223 int size; 1224 int fd; 1225 int mflag = waitok ? M_WAITOK : M_NOWAIT; 1226 1227 KQ_NOTOWNED(kq); 1228 1229 to_free = NULL; 1230 if (fops->f_isfd) { 1231 fd = ident; 1232 if (kq->kq_knlistsize <= fd) { 1233 size = kq->kq_knlistsize; 1234 while (size <= fd) 1235 size += KQEXTENT; 1236 list = malloc(size * sizeof(*list), M_KQUEUE, mflag); 1237 if (list == NULL) 1238 return ENOMEM; 1239 KQ_LOCK(kq); 1240 if (kq->kq_knlistsize > fd) { 1241 to_free = list; 1242 list = NULL; 1243 } else { 1244 if (kq->kq_knlist != NULL) { 1245 bcopy(kq->kq_knlist, list, 1246 kq->kq_knlistsize * sizeof(*list)); 1247 to_free = kq->kq_knlist; 1248 kq->kq_knlist = NULL; 1249 } 1250 bzero((caddr_t)list + 1251 kq->kq_knlistsize * sizeof(*list), 1252 (size - kq->kq_knlistsize) * sizeof(*list)); 1253 kq->kq_knlistsize = size; 1254 kq->kq_knlist = list; 1255 } 1256 KQ_UNLOCK(kq); 1257 } 1258 } else { 1259 if (kq->kq_knhashmask == 0) { 1260 tmp_knhash = hashinit(KN_HASHSIZE, M_KQUEUE, 1261 &tmp_knhashmask); 1262 if (tmp_knhash == NULL) 1263 return ENOMEM; 1264 KQ_LOCK(kq); 1265 if (kq->kq_knhashmask == 0) { 1266 kq->kq_knhash = tmp_knhash; 1267 kq->kq_knhashmask = tmp_knhashmask; 1268 } else { 1269 to_free = tmp_knhash; 1270 } 1271 KQ_UNLOCK(kq); 1272 } 1273 } 1274 free(to_free, M_KQUEUE); 1275 1276 KQ_NOTOWNED(kq); 1277 return 0; 1278 } 1279 1280 static void 1281 kqueue_task(void *arg, int pending) 1282 { 1283 struct kqueue *kq; 1284 int haskqglobal; 1285 1286 haskqglobal = 0; 1287 kq = arg; 1288 1289 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1290 KQ_LOCK(kq); 1291 1292 KNOTE_LOCKED(&kq->kq_sel.si_note, 0); 1293 1294 kq->kq_state &= ~KQ_TASKSCHED; 1295 if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) { 1296 wakeup(&kq->kq_state); 1297 } 1298 KQ_UNLOCK(kq); 1299 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1300 } 1301 1302 /* 1303 * Scan, update kn_data (if not ONESHOT), and copyout triggered events. 1304 * We treat KN_MARKER knotes as if they are INFLUX. 1305 */ 1306 static int 1307 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops, 1308 const struct timespec *tsp, struct kevent *keva, struct thread *td) 1309 { 1310 struct kevent *kevp; 1311 struct timeval atv, rtv, ttv; 1312 struct knote *kn, *marker; 1313 int count, timeout, nkev, error, influx; 1314 int haskqglobal, touch; 1315 1316 count = maxevents; 1317 nkev = 0; 1318 error = 0; 1319 haskqglobal = 0; 1320 1321 if (maxevents == 0) 1322 goto done_nl; 1323 1324 if (tsp != NULL) { 1325 TIMESPEC_TO_TIMEVAL(&atv, tsp); 1326 if (itimerfix(&atv)) { 1327 error = EINVAL; 1328 goto done_nl; 1329 } 1330 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) 1331 timeout = -1; 1332 else 1333 timeout = atv.tv_sec > 24 * 60 * 60 ? 1334 24 * 60 * 60 * hz : tvtohz(&atv); 1335 getmicrouptime(&rtv); 1336 timevaladd(&atv, &rtv); 1337 } else { 1338 atv.tv_sec = 0; 1339 atv.tv_usec = 0; 1340 timeout = 0; 1341 } 1342 marker = knote_alloc(1); 1343 if (marker == NULL) { 1344 error = ENOMEM; 1345 goto done_nl; 1346 } 1347 marker->kn_status = KN_MARKER; 1348 KQ_LOCK(kq); 1349 goto start; 1350 1351 retry: 1352 if (atv.tv_sec || atv.tv_usec) { 1353 getmicrouptime(&rtv); 1354 if (timevalcmp(&rtv, &atv, >=)) 1355 goto done; 1356 ttv = atv; 1357 timevalsub(&ttv, &rtv); 1358 timeout = ttv.tv_sec > 24 * 60 * 60 ? 1359 24 * 60 * 60 * hz : tvtohz(&ttv); 1360 } 1361 1362 start: 1363 kevp = keva; 1364 if (kq->kq_count == 0) { 1365 if (timeout < 0) { 1366 error = EWOULDBLOCK; 1367 } else { 1368 kq->kq_state |= KQ_SLEEP; 1369 error = msleep(kq, &kq->kq_lock, PSOCK | PCATCH, 1370 "kqread", timeout); 1371 } 1372 if (error == 0) 1373 goto retry; 1374 /* don't restart after signals... */ 1375 if (error == ERESTART) 1376 error = EINTR; 1377 else if (error == EWOULDBLOCK) 1378 error = 0; 1379 goto done; 1380 } 1381 1382 TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); 1383 influx = 0; 1384 while (count) { 1385 KQ_OWNED(kq); 1386 kn = TAILQ_FIRST(&kq->kq_head); 1387 1388 if ((kn->kn_status == KN_MARKER && kn != marker) || 1389 (kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1390 if (influx) { 1391 influx = 0; 1392 KQ_FLUX_WAKEUP(kq); 1393 } 1394 kq->kq_state |= KQ_FLUXWAIT; 1395 error = msleep(kq, &kq->kq_lock, PSOCK, 1396 "kqflxwt", 0); 1397 continue; 1398 } 1399 1400 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1401 if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) { 1402 kn->kn_status &= ~KN_QUEUED; 1403 kq->kq_count--; 1404 continue; 1405 } 1406 if (kn == marker) { 1407 KQ_FLUX_WAKEUP(kq); 1408 if (count == maxevents) 1409 goto retry; 1410 goto done; 1411 } 1412 KASSERT((kn->kn_status & KN_INFLUX) == 0, 1413 ("KN_INFLUX set when not suppose to be")); 1414 1415 if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) { 1416 kn->kn_status &= ~KN_QUEUED; 1417 kn->kn_status |= KN_INFLUX; 1418 kq->kq_count--; 1419 KQ_UNLOCK(kq); 1420 /* 1421 * We don't need to lock the list since we've marked 1422 * it _INFLUX. 1423 */ 1424 *kevp = kn->kn_kevent; 1425 if (!(kn->kn_status & KN_DETACHED)) 1426 kn->kn_fop->f_detach(kn); 1427 knote_drop(kn, td); 1428 KQ_LOCK(kq); 1429 kn = NULL; 1430 } else { 1431 kn->kn_status |= KN_INFLUX; 1432 KQ_UNLOCK(kq); 1433 if ((kn->kn_status & KN_KQUEUE) == KN_KQUEUE) 1434 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1435 KN_LIST_LOCK(kn); 1436 if (kn->kn_fop->f_event(kn, 0) == 0) { 1437 KQ_LOCK(kq); 1438 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1439 kn->kn_status &= 1440 ~(KN_QUEUED | KN_ACTIVE | KN_INFLUX); 1441 kq->kq_count--; 1442 KN_LIST_UNLOCK(kn); 1443 influx = 1; 1444 continue; 1445 } 1446 touch = (!kn->kn_fop->f_isfd && 1447 kn->kn_fop->f_touch != NULL); 1448 if (touch) 1449 kn->kn_fop->f_touch(kn, kevp, EVENT_PROCESS); 1450 else 1451 *kevp = kn->kn_kevent; 1452 KQ_LOCK(kq); 1453 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1454 if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) { 1455 /* 1456 * Manually clear knotes who weren't 1457 * 'touch'ed. 1458 */ 1459 if (touch == 0 && kn->kn_flags & EV_CLEAR) { 1460 kn->kn_data = 0; 1461 kn->kn_fflags = 0; 1462 } 1463 if (kn->kn_flags & EV_DISPATCH) 1464 kn->kn_status |= KN_DISABLED; 1465 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 1466 kq->kq_count--; 1467 } else 1468 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 1469 1470 kn->kn_status &= ~(KN_INFLUX); 1471 KN_LIST_UNLOCK(kn); 1472 influx = 1; 1473 } 1474 1475 /* we are returning a copy to the user */ 1476 kevp++; 1477 nkev++; 1478 count--; 1479 1480 if (nkev == KQ_NEVENTS) { 1481 influx = 0; 1482 KQ_UNLOCK_FLUX(kq); 1483 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1484 nkev = 0; 1485 kevp = keva; 1486 KQ_LOCK(kq); 1487 if (error) 1488 break; 1489 } 1490 } 1491 TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); 1492 done: 1493 KQ_OWNED(kq); 1494 KQ_UNLOCK_FLUX(kq); 1495 knote_free(marker); 1496 done_nl: 1497 KQ_NOTOWNED(kq); 1498 if (nkev != 0) 1499 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1500 td->td_retval[0] = maxevents - count; 1501 return (error); 1502 } 1503 1504 /* 1505 * XXX 1506 * This could be expanded to call kqueue_scan, if desired. 1507 */ 1508 /*ARGSUSED*/ 1509 static int 1510 kqueue_read(struct file *fp, struct uio *uio, struct ucred *active_cred, 1511 int flags, struct thread *td) 1512 { 1513 return (ENXIO); 1514 } 1515 1516 /*ARGSUSED*/ 1517 static int 1518 kqueue_write(struct file *fp, struct uio *uio, struct ucred *active_cred, 1519 int flags, struct thread *td) 1520 { 1521 return (ENXIO); 1522 } 1523 1524 /*ARGSUSED*/ 1525 static int 1526 kqueue_truncate(struct file *fp, off_t length, struct ucred *active_cred, 1527 struct thread *td) 1528 { 1529 1530 return (EINVAL); 1531 } 1532 1533 /*ARGSUSED*/ 1534 static int 1535 kqueue_ioctl(struct file *fp, u_long cmd, void *data, 1536 struct ucred *active_cred, struct thread *td) 1537 { 1538 /* 1539 * Enabling sigio causes two major problems: 1540 * 1) infinite recursion: 1541 * Synopsys: kevent is being used to track signals and have FIOASYNC 1542 * set. On receipt of a signal this will cause a kqueue to recurse 1543 * into itself over and over. Sending the sigio causes the kqueue 1544 * to become ready, which in turn posts sigio again, forever. 1545 * Solution: this can be solved by setting a flag in the kqueue that 1546 * we have a SIGIO in progress. 1547 * 2) locking problems: 1548 * Synopsys: Kqueue is a leaf subsystem, but adding signalling puts 1549 * us above the proc and pgrp locks. 1550 * Solution: Post a signal using an async mechanism, being sure to 1551 * record a generation count in the delivery so that we do not deliver 1552 * a signal to the wrong process. 1553 * 1554 * Note, these two mechanisms are somewhat mutually exclusive! 1555 */ 1556 #if 0 1557 struct kqueue *kq; 1558 1559 kq = fp->f_data; 1560 switch (cmd) { 1561 case FIOASYNC: 1562 if (*(int *)data) { 1563 kq->kq_state |= KQ_ASYNC; 1564 } else { 1565 kq->kq_state &= ~KQ_ASYNC; 1566 } 1567 return (0); 1568 1569 case FIOSETOWN: 1570 return (fsetown(*(int *)data, &kq->kq_sigio)); 1571 1572 case FIOGETOWN: 1573 *(int *)data = fgetown(&kq->kq_sigio); 1574 return (0); 1575 } 1576 #endif 1577 1578 return (ENOTTY); 1579 } 1580 1581 /*ARGSUSED*/ 1582 static int 1583 kqueue_poll(struct file *fp, int events, struct ucred *active_cred, 1584 struct thread *td) 1585 { 1586 struct kqueue *kq; 1587 int revents = 0; 1588 int error; 1589 1590 if ((error = kqueue_acquire(fp, &kq))) 1591 return POLLERR; 1592 1593 KQ_LOCK(kq); 1594 if (events & (POLLIN | POLLRDNORM)) { 1595 if (kq->kq_count) { 1596 revents |= events & (POLLIN | POLLRDNORM); 1597 } else { 1598 selrecord(td, &kq->kq_sel); 1599 if (SEL_WAITING(&kq->kq_sel)) 1600 kq->kq_state |= KQ_SEL; 1601 } 1602 } 1603 kqueue_release(kq, 1); 1604 KQ_UNLOCK(kq); 1605 return (revents); 1606 } 1607 1608 /*ARGSUSED*/ 1609 static int 1610 kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred, 1611 struct thread *td) 1612 { 1613 1614 bzero((void *)st, sizeof *st); 1615 /* 1616 * We no longer return kq_count because the unlocked value is useless. 1617 * If you spent all this time getting the count, why not spend your 1618 * syscall better by calling kevent? 1619 * 1620 * XXX - This is needed for libc_r. 1621 */ 1622 st->st_mode = S_IFIFO; 1623 return (0); 1624 } 1625 1626 /*ARGSUSED*/ 1627 static int 1628 kqueue_close(struct file *fp, struct thread *td) 1629 { 1630 struct kqueue *kq = fp->f_data; 1631 struct filedesc *fdp; 1632 struct knote *kn; 1633 int i; 1634 int error; 1635 1636 if ((error = kqueue_acquire(fp, &kq))) 1637 return error; 1638 1639 KQ_LOCK(kq); 1640 1641 KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING, 1642 ("kqueue already closing")); 1643 kq->kq_state |= KQ_CLOSING; 1644 if (kq->kq_refcnt > 1) 1645 msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0); 1646 1647 KASSERT(kq->kq_refcnt == 1, ("other refs are out there!")); 1648 fdp = kq->kq_fdp; 1649 1650 KASSERT(knlist_empty(&kq->kq_sel.si_note), 1651 ("kqueue's knlist not empty")); 1652 1653 for (i = 0; i < kq->kq_knlistsize; i++) { 1654 while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) { 1655 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1656 kq->kq_state |= KQ_FLUXWAIT; 1657 msleep(kq, &kq->kq_lock, PSOCK, "kqclo1", 0); 1658 continue; 1659 } 1660 kn->kn_status |= KN_INFLUX; 1661 KQ_UNLOCK(kq); 1662 if (!(kn->kn_status & KN_DETACHED)) 1663 kn->kn_fop->f_detach(kn); 1664 knote_drop(kn, td); 1665 KQ_LOCK(kq); 1666 } 1667 } 1668 if (kq->kq_knhashmask != 0) { 1669 for (i = 0; i <= kq->kq_knhashmask; i++) { 1670 while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) { 1671 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1672 kq->kq_state |= KQ_FLUXWAIT; 1673 msleep(kq, &kq->kq_lock, PSOCK, 1674 "kqclo2", 0); 1675 continue; 1676 } 1677 kn->kn_status |= KN_INFLUX; 1678 KQ_UNLOCK(kq); 1679 if (!(kn->kn_status & KN_DETACHED)) 1680 kn->kn_fop->f_detach(kn); 1681 knote_drop(kn, td); 1682 KQ_LOCK(kq); 1683 } 1684 } 1685 } 1686 1687 if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) { 1688 kq->kq_state |= KQ_TASKDRAIN; 1689 msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0); 1690 } 1691 1692 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 1693 selwakeuppri(&kq->kq_sel, PSOCK); 1694 if (!SEL_WAITING(&kq->kq_sel)) 1695 kq->kq_state &= ~KQ_SEL; 1696 } 1697 1698 KQ_UNLOCK(kq); 1699 1700 FILEDESC_XLOCK(fdp); 1701 SLIST_REMOVE(&fdp->fd_kqlist, kq, kqueue, kq_list); 1702 FILEDESC_XUNLOCK(fdp); 1703 1704 knlist_destroy(&kq->kq_sel.si_note); 1705 mtx_destroy(&kq->kq_lock); 1706 kq->kq_fdp = NULL; 1707 1708 if (kq->kq_knhash != NULL) 1709 free(kq->kq_knhash, M_KQUEUE); 1710 if (kq->kq_knlist != NULL) 1711 free(kq->kq_knlist, M_KQUEUE); 1712 1713 funsetown(&kq->kq_sigio); 1714 free(kq, M_KQUEUE); 1715 fp->f_data = NULL; 1716 1717 return (0); 1718 } 1719 1720 static void 1721 kqueue_wakeup(struct kqueue *kq) 1722 { 1723 KQ_OWNED(kq); 1724 1725 if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) { 1726 kq->kq_state &= ~KQ_SLEEP; 1727 wakeup(kq); 1728 } 1729 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 1730 selwakeuppri(&kq->kq_sel, PSOCK); 1731 if (!SEL_WAITING(&kq->kq_sel)) 1732 kq->kq_state &= ~KQ_SEL; 1733 } 1734 if (!knlist_empty(&kq->kq_sel.si_note)) 1735 kqueue_schedtask(kq); 1736 if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) { 1737 pgsigio(&kq->kq_sigio, SIGIO, 0); 1738 } 1739 } 1740 1741 /* 1742 * Walk down a list of knotes, activating them if their event has triggered. 1743 * 1744 * There is a possibility to optimize in the case of one kq watching another. 1745 * Instead of scheduling a task to wake it up, you could pass enough state 1746 * down the chain to make up the parent kqueue. Make this code functional 1747 * first. 1748 */ 1749 void 1750 knote(struct knlist *list, long hint, int lockflags) 1751 { 1752 struct kqueue *kq; 1753 struct knote *kn; 1754 int error; 1755 1756 if (list == NULL) 1757 return; 1758 1759 KNL_ASSERT_LOCK(list, lockflags & KNF_LISTLOCKED); 1760 1761 if ((lockflags & KNF_LISTLOCKED) == 0) 1762 list->kl_lock(list->kl_lockarg); 1763 1764 /* 1765 * If we unlock the list lock (and set KN_INFLUX), we can eliminate 1766 * the kqueue scheduling, but this will introduce four 1767 * lock/unlock's for each knote to test. If we do, continue to use 1768 * SLIST_FOREACH, SLIST_FOREACH_SAFE is not safe in our case, it is 1769 * only safe if you want to remove the current item, which we are 1770 * not doing. 1771 */ 1772 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { 1773 kq = kn->kn_kq; 1774 if ((kn->kn_status & KN_INFLUX) != KN_INFLUX) { 1775 KQ_LOCK(kq); 1776 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1777 KQ_UNLOCK(kq); 1778 } else if ((lockflags & KNF_NOKQLOCK) != 0) { 1779 kn->kn_status |= KN_INFLUX; 1780 KQ_UNLOCK(kq); 1781 error = kn->kn_fop->f_event(kn, hint); 1782 KQ_LOCK(kq); 1783 kn->kn_status &= ~KN_INFLUX; 1784 if (error) 1785 KNOTE_ACTIVATE(kn, 1); 1786 KQ_UNLOCK_FLUX(kq); 1787 } else { 1788 kn->kn_status |= KN_HASKQLOCK; 1789 if (kn->kn_fop->f_event(kn, hint)) 1790 KNOTE_ACTIVATE(kn, 1); 1791 kn->kn_status &= ~KN_HASKQLOCK; 1792 KQ_UNLOCK(kq); 1793 } 1794 } 1795 kq = NULL; 1796 } 1797 if ((lockflags & KNF_LISTLOCKED) == 0) 1798 list->kl_unlock(list->kl_lockarg); 1799 } 1800 1801 /* 1802 * add a knote to a knlist 1803 */ 1804 void 1805 knlist_add(struct knlist *knl, struct knote *kn, int islocked) 1806 { 1807 KNL_ASSERT_LOCK(knl, islocked); 1808 KQ_NOTOWNED(kn->kn_kq); 1809 KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) == 1810 (KN_INFLUX|KN_DETACHED), ("knote not KN_INFLUX and KN_DETACHED")); 1811 if (!islocked) 1812 knl->kl_lock(knl->kl_lockarg); 1813 SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext); 1814 if (!islocked) 1815 knl->kl_unlock(knl->kl_lockarg); 1816 KQ_LOCK(kn->kn_kq); 1817 kn->kn_knlist = knl; 1818 kn->kn_status &= ~KN_DETACHED; 1819 KQ_UNLOCK(kn->kn_kq); 1820 } 1821 1822 static void 1823 knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked, int kqislocked) 1824 { 1825 KASSERT(!(!!kqislocked && !knlislocked), ("kq locked w/o knl locked")); 1826 KNL_ASSERT_LOCK(knl, knlislocked); 1827 mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED); 1828 if (!kqislocked) 1829 KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) == KN_INFLUX, 1830 ("knlist_remove called w/o knote being KN_INFLUX or already removed")); 1831 if (!knlislocked) 1832 knl->kl_lock(knl->kl_lockarg); 1833 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext); 1834 kn->kn_knlist = NULL; 1835 if (!knlislocked) 1836 knl->kl_unlock(knl->kl_lockarg); 1837 if (!kqislocked) 1838 KQ_LOCK(kn->kn_kq); 1839 kn->kn_status |= KN_DETACHED; 1840 if (!kqislocked) 1841 KQ_UNLOCK(kn->kn_kq); 1842 } 1843 1844 /* 1845 * remove all knotes from a specified klist 1846 */ 1847 void 1848 knlist_remove(struct knlist *knl, struct knote *kn, int islocked) 1849 { 1850 1851 knlist_remove_kq(knl, kn, islocked, 0); 1852 } 1853 1854 /* 1855 * remove knote from a specified klist while in f_event handler. 1856 */ 1857 void 1858 knlist_remove_inevent(struct knlist *knl, struct knote *kn) 1859 { 1860 1861 knlist_remove_kq(knl, kn, 1, 1862 (kn->kn_status & KN_HASKQLOCK) == KN_HASKQLOCK); 1863 } 1864 1865 int 1866 knlist_empty(struct knlist *knl) 1867 { 1868 KNL_ASSERT_LOCKED(knl); 1869 return SLIST_EMPTY(&knl->kl_list); 1870 } 1871 1872 static struct mtx knlist_lock; 1873 MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects", 1874 MTX_DEF); 1875 static void knlist_mtx_lock(void *arg); 1876 static void knlist_mtx_unlock(void *arg); 1877 1878 static void 1879 knlist_mtx_lock(void *arg) 1880 { 1881 mtx_lock((struct mtx *)arg); 1882 } 1883 1884 static void 1885 knlist_mtx_unlock(void *arg) 1886 { 1887 mtx_unlock((struct mtx *)arg); 1888 } 1889 1890 static void 1891 knlist_mtx_assert_locked(void *arg) 1892 { 1893 mtx_assert((struct mtx *)arg, MA_OWNED); 1894 } 1895 1896 static void 1897 knlist_mtx_assert_unlocked(void *arg) 1898 { 1899 mtx_assert((struct mtx *)arg, MA_NOTOWNED); 1900 } 1901 1902 void 1903 knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *), 1904 void (*kl_unlock)(void *), 1905 void (*kl_assert_locked)(void *), void (*kl_assert_unlocked)(void *)) 1906 { 1907 1908 if (lock == NULL) 1909 knl->kl_lockarg = &knlist_lock; 1910 else 1911 knl->kl_lockarg = lock; 1912 1913 if (kl_lock == NULL) 1914 knl->kl_lock = knlist_mtx_lock; 1915 else 1916 knl->kl_lock = kl_lock; 1917 if (kl_unlock == NULL) 1918 knl->kl_unlock = knlist_mtx_unlock; 1919 else 1920 knl->kl_unlock = kl_unlock; 1921 if (kl_assert_locked == NULL) 1922 knl->kl_assert_locked = knlist_mtx_assert_locked; 1923 else 1924 knl->kl_assert_locked = kl_assert_locked; 1925 if (kl_assert_unlocked == NULL) 1926 knl->kl_assert_unlocked = knlist_mtx_assert_unlocked; 1927 else 1928 knl->kl_assert_unlocked = kl_assert_unlocked; 1929 1930 SLIST_INIT(&knl->kl_list); 1931 } 1932 1933 void 1934 knlist_init_mtx(struct knlist *knl, struct mtx *lock) 1935 { 1936 1937 knlist_init(knl, lock, NULL, NULL, NULL, NULL); 1938 } 1939 1940 void 1941 knlist_destroy(struct knlist *knl) 1942 { 1943 1944 #ifdef INVARIANTS 1945 /* 1946 * if we run across this error, we need to find the offending 1947 * driver and have it call knlist_clear. 1948 */ 1949 if (!SLIST_EMPTY(&knl->kl_list)) 1950 printf("WARNING: destroying knlist w/ knotes on it!\n"); 1951 #endif 1952 1953 knl->kl_lockarg = knl->kl_lock = knl->kl_unlock = NULL; 1954 SLIST_INIT(&knl->kl_list); 1955 } 1956 1957 /* 1958 * Even if we are locked, we may need to drop the lock to allow any influx 1959 * knotes time to "settle". 1960 */ 1961 void 1962 knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn) 1963 { 1964 struct knote *kn, *kn2; 1965 struct kqueue *kq; 1966 1967 if (islocked) 1968 KNL_ASSERT_LOCKED(knl); 1969 else { 1970 KNL_ASSERT_UNLOCKED(knl); 1971 again: /* need to reacquire lock since we have dropped it */ 1972 knl->kl_lock(knl->kl_lockarg); 1973 } 1974 1975 SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) { 1976 kq = kn->kn_kq; 1977 KQ_LOCK(kq); 1978 if ((kn->kn_status & KN_INFLUX)) { 1979 KQ_UNLOCK(kq); 1980 continue; 1981 } 1982 knlist_remove_kq(knl, kn, 1, 1); 1983 if (killkn) { 1984 kn->kn_status |= KN_INFLUX | KN_DETACHED; 1985 KQ_UNLOCK(kq); 1986 knote_drop(kn, td); 1987 } else { 1988 /* Make sure cleared knotes disappear soon */ 1989 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 1990 KQ_UNLOCK(kq); 1991 } 1992 kq = NULL; 1993 } 1994 1995 if (!SLIST_EMPTY(&knl->kl_list)) { 1996 /* there are still KN_INFLUX remaining */ 1997 kn = SLIST_FIRST(&knl->kl_list); 1998 kq = kn->kn_kq; 1999 KQ_LOCK(kq); 2000 KASSERT(kn->kn_status & KN_INFLUX, 2001 ("knote removed w/o list lock")); 2002 knl->kl_unlock(knl->kl_lockarg); 2003 kq->kq_state |= KQ_FLUXWAIT; 2004 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0); 2005 kq = NULL; 2006 goto again; 2007 } 2008 2009 if (islocked) 2010 KNL_ASSERT_LOCKED(knl); 2011 else { 2012 knl->kl_unlock(knl->kl_lockarg); 2013 KNL_ASSERT_UNLOCKED(knl); 2014 } 2015 } 2016 2017 /* 2018 * Remove all knotes referencing a specified fd must be called with FILEDESC 2019 * lock. This prevents a race where a new fd comes along and occupies the 2020 * entry and we attach a knote to the fd. 2021 */ 2022 void 2023 knote_fdclose(struct thread *td, int fd) 2024 { 2025 struct filedesc *fdp = td->td_proc->p_fd; 2026 struct kqueue *kq; 2027 struct knote *kn; 2028 int influx; 2029 2030 FILEDESC_XLOCK_ASSERT(fdp); 2031 2032 /* 2033 * We shouldn't have to worry about new kevents appearing on fd 2034 * since filedesc is locked. 2035 */ 2036 SLIST_FOREACH(kq, &fdp->fd_kqlist, kq_list) { 2037 KQ_LOCK(kq); 2038 2039 again: 2040 influx = 0; 2041 while (kq->kq_knlistsize > fd && 2042 (kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) { 2043 if (kn->kn_status & KN_INFLUX) { 2044 /* someone else might be waiting on our knote */ 2045 if (influx) 2046 wakeup(kq); 2047 kq->kq_state |= KQ_FLUXWAIT; 2048 msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0); 2049 goto again; 2050 } 2051 kn->kn_status |= KN_INFLUX; 2052 KQ_UNLOCK(kq); 2053 if (!(kn->kn_status & KN_DETACHED)) 2054 kn->kn_fop->f_detach(kn); 2055 knote_drop(kn, td); 2056 influx = 1; 2057 KQ_LOCK(kq); 2058 } 2059 KQ_UNLOCK_FLUX(kq); 2060 } 2061 } 2062 2063 static int 2064 knote_attach(struct knote *kn, struct kqueue *kq) 2065 { 2066 struct klist *list; 2067 2068 KASSERT(kn->kn_status & KN_INFLUX, ("knote not marked INFLUX")); 2069 KQ_OWNED(kq); 2070 2071 if (kn->kn_fop->f_isfd) { 2072 if (kn->kn_id >= kq->kq_knlistsize) 2073 return ENOMEM; 2074 list = &kq->kq_knlist[kn->kn_id]; 2075 } else { 2076 if (kq->kq_knhash == NULL) 2077 return ENOMEM; 2078 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2079 } 2080 2081 SLIST_INSERT_HEAD(list, kn, kn_link); 2082 2083 return 0; 2084 } 2085 2086 /* 2087 * knote must already have been detached using the f_detach method. 2088 * no lock need to be held, it is assumed that the KN_INFLUX flag is set 2089 * to prevent other removal. 2090 */ 2091 static void 2092 knote_drop(struct knote *kn, struct thread *td) 2093 { 2094 struct kqueue *kq; 2095 struct klist *list; 2096 2097 kq = kn->kn_kq; 2098 2099 KQ_NOTOWNED(kq); 2100 KASSERT((kn->kn_status & KN_INFLUX) == KN_INFLUX, 2101 ("knote_drop called without KN_INFLUX set in kn_status")); 2102 2103 KQ_LOCK(kq); 2104 if (kn->kn_fop->f_isfd) 2105 list = &kq->kq_knlist[kn->kn_id]; 2106 else 2107 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2108 2109 if (!SLIST_EMPTY(list)) 2110 SLIST_REMOVE(list, kn, knote, kn_link); 2111 if (kn->kn_status & KN_QUEUED) 2112 knote_dequeue(kn); 2113 KQ_UNLOCK_FLUX(kq); 2114 2115 if (kn->kn_fop->f_isfd) { 2116 fdrop(kn->kn_fp, td); 2117 kn->kn_fp = NULL; 2118 } 2119 kqueue_fo_release(kn->kn_kevent.filter); 2120 kn->kn_fop = NULL; 2121 knote_free(kn); 2122 } 2123 2124 static void 2125 knote_enqueue(struct knote *kn) 2126 { 2127 struct kqueue *kq = kn->kn_kq; 2128 2129 KQ_OWNED(kn->kn_kq); 2130 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 2131 2132 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2133 kn->kn_status |= KN_QUEUED; 2134 kq->kq_count++; 2135 kqueue_wakeup(kq); 2136 } 2137 2138 static void 2139 knote_dequeue(struct knote *kn) 2140 { 2141 struct kqueue *kq = kn->kn_kq; 2142 2143 KQ_OWNED(kn->kn_kq); 2144 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 2145 2146 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 2147 kn->kn_status &= ~KN_QUEUED; 2148 kq->kq_count--; 2149 } 2150 2151 static void 2152 knote_init(void) 2153 { 2154 2155 knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL, 2156 NULL, NULL, UMA_ALIGN_PTR, 0); 2157 } 2158 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL); 2159 2160 static struct knote * 2161 knote_alloc(int waitok) 2162 { 2163 return ((struct knote *)uma_zalloc(knote_zone, 2164 (waitok ? M_WAITOK : M_NOWAIT)|M_ZERO)); 2165 } 2166 2167 static void 2168 knote_free(struct knote *kn) 2169 { 2170 if (kn != NULL) 2171 uma_zfree(knote_zone, kn); 2172 } 2173 2174 /* 2175 * Register the kev w/ the kq specified by fd. 2176 */ 2177 int 2178 kqfd_register(int fd, struct kevent *kev, struct thread *td, int waitok) 2179 { 2180 struct kqueue *kq; 2181 struct file *fp; 2182 int error; 2183 2184 if ((error = fget(td, fd, &fp)) != 0) 2185 return (error); 2186 if ((error = kqueue_acquire(fp, &kq)) != 0) 2187 goto noacquire; 2188 2189 error = kqueue_register(kq, kev, td, waitok); 2190 2191 kqueue_release(kq, 0); 2192 2193 noacquire: 2194 fdrop(fp, td); 2195 2196 return error; 2197 } 2198