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/proc.h> 41 #include <sys/malloc.h> 42 #include <sys/unistd.h> 43 #include <sys/file.h> 44 #include <sys/filedesc.h> 45 #include <sys/filio.h> 46 #include <sys/fcntl.h> 47 #include <sys/kthread.h> 48 #include <sys/selinfo.h> 49 #include <sys/queue.h> 50 #include <sys/event.h> 51 #include <sys/eventvar.h> 52 #include <sys/poll.h> 53 #include <sys/protosw.h> 54 #include <sys/sigio.h> 55 #include <sys/signalvar.h> 56 #include <sys/socket.h> 57 #include <sys/socketvar.h> 58 #include <sys/stat.h> 59 #include <sys/sysctl.h> 60 #include <sys/sysproto.h> 61 #include <sys/syscallsubr.h> 62 #include <sys/taskqueue.h> 63 #include <sys/uio.h> 64 #ifdef KTRACE 65 #include <sys/ktrace.h> 66 #endif 67 68 #include <vm/uma.h> 69 70 static MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system"); 71 72 /* 73 * This lock is used if multiple kq locks are required. This possibly 74 * should be made into a per proc lock. 75 */ 76 static struct mtx kq_global; 77 MTX_SYSINIT(kq_global, &kq_global, "kqueue order", MTX_DEF); 78 #define KQ_GLOBAL_LOCK(lck, haslck) do { \ 79 if (!haslck) \ 80 mtx_lock(lck); \ 81 haslck = 1; \ 82 } while (0) 83 #define KQ_GLOBAL_UNLOCK(lck, haslck) do { \ 84 if (haslck) \ 85 mtx_unlock(lck); \ 86 haslck = 0; \ 87 } while (0) 88 89 TASKQUEUE_DEFINE_THREAD(kqueue); 90 91 static int kevent_copyout(void *arg, struct kevent *kevp, int count); 92 static int kevent_copyin(void *arg, struct kevent *kevp, int count); 93 static int kqueue_register(struct kqueue *kq, struct kevent *kev, 94 struct thread *td, int waitok); 95 static int kqueue_acquire(struct file *fp, struct kqueue **kqp); 96 static void kqueue_release(struct kqueue *kq, int locked); 97 static int kqueue_expand(struct kqueue *kq, struct filterops *fops, 98 uintptr_t ident, int waitok); 99 static void kqueue_task(void *arg, int pending); 100 static int kqueue_scan(struct kqueue *kq, int maxevents, 101 struct kevent_copyops *k_ops, 102 const struct timespec *timeout, 103 struct kevent *keva, struct thread *td); 104 static void kqueue_wakeup(struct kqueue *kq); 105 static struct filterops *kqueue_fo_find(int filt); 106 static void kqueue_fo_release(int filt); 107 108 static fo_rdwr_t kqueue_read; 109 static fo_rdwr_t kqueue_write; 110 static fo_truncate_t kqueue_truncate; 111 static fo_ioctl_t kqueue_ioctl; 112 static fo_poll_t kqueue_poll; 113 static fo_kqfilter_t kqueue_kqfilter; 114 static fo_stat_t kqueue_stat; 115 static fo_close_t kqueue_close; 116 117 static struct fileops kqueueops = { 118 .fo_read = kqueue_read, 119 .fo_write = kqueue_write, 120 .fo_truncate = kqueue_truncate, 121 .fo_ioctl = kqueue_ioctl, 122 .fo_poll = kqueue_poll, 123 .fo_kqfilter = kqueue_kqfilter, 124 .fo_stat = kqueue_stat, 125 .fo_close = kqueue_close, 126 .fo_chmod = invfo_chmod, 127 .fo_chown = invfo_chown, 128 }; 129 130 static int knote_attach(struct knote *kn, struct kqueue *kq); 131 static void knote_drop(struct knote *kn, struct thread *td); 132 static void knote_enqueue(struct knote *kn); 133 static void knote_dequeue(struct knote *kn); 134 static void knote_init(void); 135 static struct knote *knote_alloc(int waitok); 136 static void knote_free(struct knote *kn); 137 138 static void filt_kqdetach(struct knote *kn); 139 static int filt_kqueue(struct knote *kn, long hint); 140 static int filt_procattach(struct knote *kn); 141 static void filt_procdetach(struct knote *kn); 142 static int filt_proc(struct knote *kn, long hint); 143 static int filt_fileattach(struct knote *kn); 144 static void filt_timerexpire(void *knx); 145 static int filt_timerattach(struct knote *kn); 146 static void filt_timerdetach(struct knote *kn); 147 static int filt_timer(struct knote *kn, long hint); 148 static int filt_userattach(struct knote *kn); 149 static void filt_userdetach(struct knote *kn); 150 static int filt_user(struct knote *kn, long hint); 151 static void filt_usertouch(struct knote *kn, struct kevent *kev, 152 u_long type); 153 154 static struct filterops file_filtops = { 155 .f_isfd = 1, 156 .f_attach = filt_fileattach, 157 }; 158 static struct filterops kqread_filtops = { 159 .f_isfd = 1, 160 .f_detach = filt_kqdetach, 161 .f_event = filt_kqueue, 162 }; 163 /* XXX - move to kern_proc.c? */ 164 static struct filterops proc_filtops = { 165 .f_isfd = 0, 166 .f_attach = filt_procattach, 167 .f_detach = filt_procdetach, 168 .f_event = filt_proc, 169 }; 170 static struct filterops timer_filtops = { 171 .f_isfd = 0, 172 .f_attach = filt_timerattach, 173 .f_detach = filt_timerdetach, 174 .f_event = filt_timer, 175 }; 176 static struct filterops user_filtops = { 177 .f_attach = filt_userattach, 178 .f_detach = filt_userdetach, 179 .f_event = filt_user, 180 .f_touch = filt_usertouch, 181 }; 182 183 static uma_zone_t knote_zone; 184 static int kq_ncallouts = 0; 185 static int kq_calloutmax = (4 * 1024); 186 SYSCTL_INT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW, 187 &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue"); 188 189 /* XXX - ensure not KN_INFLUX?? */ 190 #define KNOTE_ACTIVATE(kn, islock) do { \ 191 if ((islock)) \ 192 mtx_assert(&(kn)->kn_kq->kq_lock, MA_OWNED); \ 193 else \ 194 KQ_LOCK((kn)->kn_kq); \ 195 (kn)->kn_status |= KN_ACTIVE; \ 196 if (((kn)->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 197 knote_enqueue((kn)); \ 198 if (!(islock)) \ 199 KQ_UNLOCK((kn)->kn_kq); \ 200 } while(0) 201 #define KQ_LOCK(kq) do { \ 202 mtx_lock(&(kq)->kq_lock); \ 203 } while (0) 204 #define KQ_FLUX_WAKEUP(kq) do { \ 205 if (((kq)->kq_state & KQ_FLUXWAIT) == KQ_FLUXWAIT) { \ 206 (kq)->kq_state &= ~KQ_FLUXWAIT; \ 207 wakeup((kq)); \ 208 } \ 209 } while (0) 210 #define KQ_UNLOCK_FLUX(kq) do { \ 211 KQ_FLUX_WAKEUP(kq); \ 212 mtx_unlock(&(kq)->kq_lock); \ 213 } while (0) 214 #define KQ_UNLOCK(kq) do { \ 215 mtx_unlock(&(kq)->kq_lock); \ 216 } while (0) 217 #define KQ_OWNED(kq) do { \ 218 mtx_assert(&(kq)->kq_lock, MA_OWNED); \ 219 } while (0) 220 #define KQ_NOTOWNED(kq) do { \ 221 mtx_assert(&(kq)->kq_lock, MA_NOTOWNED); \ 222 } while (0) 223 #define KN_LIST_LOCK(kn) do { \ 224 if (kn->kn_knlist != NULL) \ 225 kn->kn_knlist->kl_lock(kn->kn_knlist->kl_lockarg); \ 226 } while (0) 227 #define KN_LIST_UNLOCK(kn) do { \ 228 if (kn->kn_knlist != NULL) \ 229 kn->kn_knlist->kl_unlock(kn->kn_knlist->kl_lockarg); \ 230 } while (0) 231 #define KNL_ASSERT_LOCK(knl, islocked) do { \ 232 if (islocked) \ 233 KNL_ASSERT_LOCKED(knl); \ 234 else \ 235 KNL_ASSERT_UNLOCKED(knl); \ 236 } while (0) 237 #ifdef INVARIANTS 238 #define KNL_ASSERT_LOCKED(knl) do { \ 239 knl->kl_assert_locked((knl)->kl_lockarg); \ 240 } while (0) 241 #define KNL_ASSERT_UNLOCKED(knl) do { \ 242 knl->kl_assert_unlocked((knl)->kl_lockarg); \ 243 } while (0) 244 #else /* !INVARIANTS */ 245 #define KNL_ASSERT_LOCKED(knl) do {} while(0) 246 #define KNL_ASSERT_UNLOCKED(knl) do {} while (0) 247 #endif /* INVARIANTS */ 248 249 #define KN_HASHSIZE 64 /* XXX should be tunable */ 250 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 251 252 static int 253 filt_nullattach(struct knote *kn) 254 { 255 256 return (ENXIO); 257 }; 258 259 struct filterops null_filtops = { 260 .f_isfd = 0, 261 .f_attach = filt_nullattach, 262 }; 263 264 /* XXX - make SYSINIT to add these, and move into respective modules. */ 265 extern struct filterops sig_filtops; 266 extern struct filterops fs_filtops; 267 268 /* 269 * Table for for all system-defined filters. 270 */ 271 static struct mtx filterops_lock; 272 MTX_SYSINIT(kqueue_filterops, &filterops_lock, "protect sysfilt_ops", 273 MTX_DEF); 274 static struct { 275 struct filterops *for_fop; 276 int for_refcnt; 277 } sysfilt_ops[EVFILT_SYSCOUNT] = { 278 { &file_filtops }, /* EVFILT_READ */ 279 { &file_filtops }, /* EVFILT_WRITE */ 280 { &null_filtops }, /* EVFILT_AIO */ 281 { &file_filtops }, /* EVFILT_VNODE */ 282 { &proc_filtops }, /* EVFILT_PROC */ 283 { &sig_filtops }, /* EVFILT_SIGNAL */ 284 { &timer_filtops }, /* EVFILT_TIMER */ 285 { &null_filtops }, /* former EVFILT_NETDEV */ 286 { &fs_filtops }, /* EVFILT_FS */ 287 { &null_filtops }, /* EVFILT_LIO */ 288 { &user_filtops }, /* EVFILT_USER */ 289 }; 290 291 /* 292 * Simple redirection for all cdevsw style objects to call their fo_kqfilter 293 * method. 294 */ 295 static int 296 filt_fileattach(struct knote *kn) 297 { 298 299 return (fo_kqfilter(kn->kn_fp, kn)); 300 } 301 302 /*ARGSUSED*/ 303 static int 304 kqueue_kqfilter(struct file *fp, struct knote *kn) 305 { 306 struct kqueue *kq = kn->kn_fp->f_data; 307 308 if (kn->kn_filter != EVFILT_READ) 309 return (EINVAL); 310 311 kn->kn_status |= KN_KQUEUE; 312 kn->kn_fop = &kqread_filtops; 313 knlist_add(&kq->kq_sel.si_note, kn, 0); 314 315 return (0); 316 } 317 318 static void 319 filt_kqdetach(struct knote *kn) 320 { 321 struct kqueue *kq = kn->kn_fp->f_data; 322 323 knlist_remove(&kq->kq_sel.si_note, kn, 0); 324 } 325 326 /*ARGSUSED*/ 327 static int 328 filt_kqueue(struct knote *kn, long hint) 329 { 330 struct kqueue *kq = kn->kn_fp->f_data; 331 332 kn->kn_data = kq->kq_count; 333 return (kn->kn_data > 0); 334 } 335 336 /* XXX - move to kern_proc.c? */ 337 static int 338 filt_procattach(struct knote *kn) 339 { 340 struct proc *p; 341 int immediate; 342 int error; 343 344 immediate = 0; 345 p = pfind(kn->kn_id); 346 if (p == NULL && (kn->kn_sfflags & NOTE_EXIT)) { 347 p = zpfind(kn->kn_id); 348 immediate = 1; 349 } else if (p != NULL && (p->p_flag & P_WEXIT)) { 350 immediate = 1; 351 } 352 353 if (p == NULL) 354 return (ESRCH); 355 if ((error = p_cansee(curthread, p))) { 356 PROC_UNLOCK(p); 357 return (error); 358 } 359 360 kn->kn_ptr.p_proc = p; 361 kn->kn_flags |= EV_CLEAR; /* automatically set */ 362 363 /* 364 * internal flag indicating registration done by kernel 365 */ 366 if (kn->kn_flags & EV_FLAG1) { 367 kn->kn_data = kn->kn_sdata; /* ppid */ 368 kn->kn_fflags = NOTE_CHILD; 369 kn->kn_flags &= ~EV_FLAG1; 370 } 371 372 if (immediate == 0) 373 knlist_add(&p->p_klist, kn, 1); 374 375 /* 376 * Immediately activate any exit notes if the target process is a 377 * zombie. This is necessary to handle the case where the target 378 * process, e.g. a child, dies before the kevent is registered. 379 */ 380 if (immediate && filt_proc(kn, NOTE_EXIT)) 381 KNOTE_ACTIVATE(kn, 0); 382 383 PROC_UNLOCK(p); 384 385 return (0); 386 } 387 388 /* 389 * The knote may be attached to a different process, which may exit, 390 * leaving nothing for the knote to be attached to. So when the process 391 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 392 * it will be deleted when read out. However, as part of the knote deletion, 393 * this routine is called, so a check is needed to avoid actually performing 394 * a detach, because the original process does not exist any more. 395 */ 396 /* XXX - move to kern_proc.c? */ 397 static void 398 filt_procdetach(struct knote *kn) 399 { 400 struct proc *p; 401 402 p = kn->kn_ptr.p_proc; 403 knlist_remove(&p->p_klist, kn, 0); 404 kn->kn_ptr.p_proc = NULL; 405 } 406 407 /* XXX - move to kern_proc.c? */ 408 static int 409 filt_proc(struct knote *kn, long hint) 410 { 411 struct proc *p = kn->kn_ptr.p_proc; 412 u_int event; 413 414 /* 415 * mask off extra data 416 */ 417 event = (u_int)hint & NOTE_PCTRLMASK; 418 419 /* 420 * if the user is interested in this event, record it. 421 */ 422 if (kn->kn_sfflags & event) 423 kn->kn_fflags |= event; 424 425 /* 426 * process is gone, so flag the event as finished. 427 */ 428 if (event == NOTE_EXIT) { 429 if (!(kn->kn_status & KN_DETACHED)) 430 knlist_remove_inevent(&p->p_klist, kn); 431 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 432 kn->kn_data = p->p_xstat; 433 kn->kn_ptr.p_proc = NULL; 434 return (1); 435 } 436 437 return (kn->kn_fflags != 0); 438 } 439 440 /* 441 * Called when the process forked. It mostly does the same as the 442 * knote(), activating all knotes registered to be activated when the 443 * process forked. Additionally, for each knote attached to the 444 * parent, check whether user wants to track the new process. If so 445 * attach a new knote to it, and immediately report an event with the 446 * child's pid. 447 */ 448 void 449 knote_fork(struct knlist *list, int pid) 450 { 451 struct kqueue *kq; 452 struct knote *kn; 453 struct kevent kev; 454 int error; 455 456 if (list == NULL) 457 return; 458 list->kl_lock(list->kl_lockarg); 459 460 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { 461 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) 462 continue; 463 kq = kn->kn_kq; 464 KQ_LOCK(kq); 465 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 466 KQ_UNLOCK(kq); 467 continue; 468 } 469 470 /* 471 * The same as knote(), activate the event. 472 */ 473 if ((kn->kn_sfflags & NOTE_TRACK) == 0) { 474 kn->kn_status |= KN_HASKQLOCK; 475 if (kn->kn_fop->f_event(kn, NOTE_FORK | pid)) 476 KNOTE_ACTIVATE(kn, 1); 477 kn->kn_status &= ~KN_HASKQLOCK; 478 KQ_UNLOCK(kq); 479 continue; 480 } 481 482 /* 483 * The NOTE_TRACK case. In addition to the activation 484 * of the event, we need to register new event to 485 * track the child. Drop the locks in preparation for 486 * the call to kqueue_register(). 487 */ 488 kn->kn_status |= KN_INFLUX; 489 KQ_UNLOCK(kq); 490 list->kl_unlock(list->kl_lockarg); 491 492 /* 493 * Activate existing knote and register a knote with 494 * new process. 495 */ 496 kev.ident = pid; 497 kev.filter = kn->kn_filter; 498 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 499 kev.fflags = kn->kn_sfflags; 500 kev.data = kn->kn_id; /* parent */ 501 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 502 error = kqueue_register(kq, &kev, NULL, 0); 503 if (kn->kn_fop->f_event(kn, NOTE_FORK | pid)) 504 KNOTE_ACTIVATE(kn, 0); 505 if (error) 506 kn->kn_fflags |= NOTE_TRACKERR; 507 KQ_LOCK(kq); 508 kn->kn_status &= ~KN_INFLUX; 509 KQ_UNLOCK_FLUX(kq); 510 list->kl_lock(list->kl_lockarg); 511 } 512 list->kl_unlock(list->kl_lockarg); 513 } 514 515 static int 516 timertoticks(intptr_t data) 517 { 518 struct timeval tv; 519 int tticks; 520 521 tv.tv_sec = data / 1000; 522 tv.tv_usec = (data % 1000) * 1000; 523 tticks = tvtohz(&tv); 524 525 return tticks; 526 } 527 528 /* XXX - move to kern_timeout.c? */ 529 static void 530 filt_timerexpire(void *knx) 531 { 532 struct knote *kn = knx; 533 struct callout *calloutp; 534 535 kn->kn_data++; 536 KNOTE_ACTIVATE(kn, 0); /* XXX - handle locking */ 537 538 if ((kn->kn_flags & EV_ONESHOT) != EV_ONESHOT) { 539 calloutp = (struct callout *)kn->kn_hook; 540 callout_reset_curcpu(calloutp, timertoticks(kn->kn_sdata), 541 filt_timerexpire, kn); 542 } 543 } 544 545 /* 546 * data contains amount of time to sleep, in milliseconds 547 */ 548 /* XXX - move to kern_timeout.c? */ 549 static int 550 filt_timerattach(struct knote *kn) 551 { 552 struct callout *calloutp; 553 554 atomic_add_int(&kq_ncallouts, 1); 555 556 if (kq_ncallouts >= kq_calloutmax) { 557 atomic_add_int(&kq_ncallouts, -1); 558 return (ENOMEM); 559 } 560 561 kn->kn_flags |= EV_CLEAR; /* automatically set */ 562 kn->kn_status &= ~KN_DETACHED; /* knlist_add usually sets it */ 563 calloutp = malloc(sizeof(*calloutp), M_KQUEUE, M_WAITOK); 564 callout_init(calloutp, CALLOUT_MPSAFE); 565 kn->kn_hook = calloutp; 566 callout_reset_curcpu(calloutp, timertoticks(kn->kn_sdata), 567 filt_timerexpire, kn); 568 569 return (0); 570 } 571 572 /* XXX - move to kern_timeout.c? */ 573 static void 574 filt_timerdetach(struct knote *kn) 575 { 576 struct callout *calloutp; 577 578 calloutp = (struct callout *)kn->kn_hook; 579 callout_drain(calloutp); 580 free(calloutp, M_KQUEUE); 581 atomic_add_int(&kq_ncallouts, -1); 582 kn->kn_status |= KN_DETACHED; /* knlist_remove usually clears it */ 583 } 584 585 /* XXX - move to kern_timeout.c? */ 586 static int 587 filt_timer(struct knote *kn, long hint) 588 { 589 590 return (kn->kn_data != 0); 591 } 592 593 static int 594 filt_userattach(struct knote *kn) 595 { 596 597 /* 598 * EVFILT_USER knotes are not attached to anything in the kernel. 599 */ 600 kn->kn_hook = NULL; 601 if (kn->kn_fflags & NOTE_TRIGGER) 602 kn->kn_hookid = 1; 603 else 604 kn->kn_hookid = 0; 605 return (0); 606 } 607 608 static void 609 filt_userdetach(__unused struct knote *kn) 610 { 611 612 /* 613 * EVFILT_USER knotes are not attached to anything in the kernel. 614 */ 615 } 616 617 static int 618 filt_user(struct knote *kn, __unused long hint) 619 { 620 621 return (kn->kn_hookid); 622 } 623 624 static void 625 filt_usertouch(struct knote *kn, struct kevent *kev, u_long type) 626 { 627 u_int ffctrl; 628 629 switch (type) { 630 case EVENT_REGISTER: 631 if (kev->fflags & NOTE_TRIGGER) 632 kn->kn_hookid = 1; 633 634 ffctrl = kev->fflags & NOTE_FFCTRLMASK; 635 kev->fflags &= NOTE_FFLAGSMASK; 636 switch (ffctrl) { 637 case NOTE_FFNOP: 638 break; 639 640 case NOTE_FFAND: 641 kn->kn_sfflags &= kev->fflags; 642 break; 643 644 case NOTE_FFOR: 645 kn->kn_sfflags |= kev->fflags; 646 break; 647 648 case NOTE_FFCOPY: 649 kn->kn_sfflags = kev->fflags; 650 break; 651 652 default: 653 /* XXX Return error? */ 654 break; 655 } 656 kn->kn_sdata = kev->data; 657 if (kev->flags & EV_CLEAR) { 658 kn->kn_hookid = 0; 659 kn->kn_data = 0; 660 kn->kn_fflags = 0; 661 } 662 break; 663 664 case EVENT_PROCESS: 665 *kev = kn->kn_kevent; 666 kev->fflags = kn->kn_sfflags; 667 kev->data = kn->kn_sdata; 668 if (kn->kn_flags & EV_CLEAR) { 669 kn->kn_hookid = 0; 670 kn->kn_data = 0; 671 kn->kn_fflags = 0; 672 } 673 break; 674 675 default: 676 panic("filt_usertouch() - invalid type (%ld)", type); 677 break; 678 } 679 } 680 681 int 682 sys_kqueue(struct thread *td, struct kqueue_args *uap) 683 { 684 struct filedesc *fdp; 685 struct kqueue *kq; 686 struct file *fp; 687 int fd, error; 688 689 fdp = td->td_proc->p_fd; 690 error = falloc(td, &fp, &fd, 0); 691 if (error) 692 goto done2; 693 694 /* An extra reference on `nfp' has been held for us by falloc(). */ 695 kq = malloc(sizeof *kq, M_KQUEUE, M_WAITOK | M_ZERO); 696 mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF|MTX_DUPOK); 697 TAILQ_INIT(&kq->kq_head); 698 kq->kq_fdp = fdp; 699 knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock); 700 TASK_INIT(&kq->kq_task, 0, kqueue_task, kq); 701 702 FILEDESC_XLOCK(fdp); 703 SLIST_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list); 704 FILEDESC_XUNLOCK(fdp); 705 706 finit(fp, FREAD | FWRITE, DTYPE_KQUEUE, kq, &kqueueops); 707 fdrop(fp, td); 708 709 td->td_retval[0] = fd; 710 done2: 711 return (error); 712 } 713 714 #ifndef _SYS_SYSPROTO_H_ 715 struct kevent_args { 716 int fd; 717 const struct kevent *changelist; 718 int nchanges; 719 struct kevent *eventlist; 720 int nevents; 721 const struct timespec *timeout; 722 }; 723 #endif 724 int 725 sys_kevent(struct thread *td, struct kevent_args *uap) 726 { 727 struct timespec ts, *tsp; 728 struct kevent_copyops k_ops = { uap, 729 kevent_copyout, 730 kevent_copyin}; 731 int error; 732 #ifdef KTRACE 733 struct uio ktruio; 734 struct iovec ktriov; 735 struct uio *ktruioin = NULL; 736 struct uio *ktruioout = NULL; 737 #endif 738 739 if (uap->timeout != NULL) { 740 error = copyin(uap->timeout, &ts, sizeof(ts)); 741 if (error) 742 return (error); 743 tsp = &ts; 744 } else 745 tsp = NULL; 746 747 #ifdef KTRACE 748 if (KTRPOINT(td, KTR_GENIO)) { 749 ktriov.iov_base = uap->changelist; 750 ktriov.iov_len = uap->nchanges * sizeof(struct kevent); 751 ktruio = (struct uio){ .uio_iov = &ktriov, .uio_iovcnt = 1, 752 .uio_segflg = UIO_USERSPACE, .uio_rw = UIO_READ, 753 .uio_td = td }; 754 ktruioin = cloneuio(&ktruio); 755 ktriov.iov_base = uap->eventlist; 756 ktriov.iov_len = uap->nevents * sizeof(struct kevent); 757 ktruioout = cloneuio(&ktruio); 758 } 759 #endif 760 761 error = kern_kevent(td, uap->fd, uap->nchanges, uap->nevents, 762 &k_ops, tsp); 763 764 #ifdef KTRACE 765 if (ktruioin != NULL) { 766 ktruioin->uio_resid = uap->nchanges * sizeof(struct kevent); 767 ktrgenio(uap->fd, UIO_WRITE, ktruioin, 0); 768 ktruioout->uio_resid = td->td_retval[0] * sizeof(struct kevent); 769 ktrgenio(uap->fd, UIO_READ, ktruioout, error); 770 } 771 #endif 772 773 return (error); 774 } 775 776 /* 777 * Copy 'count' items into the destination list pointed to by uap->eventlist. 778 */ 779 static int 780 kevent_copyout(void *arg, struct kevent *kevp, int count) 781 { 782 struct kevent_args *uap; 783 int error; 784 785 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 786 uap = (struct kevent_args *)arg; 787 788 error = copyout(kevp, uap->eventlist, count * sizeof *kevp); 789 if (error == 0) 790 uap->eventlist += count; 791 return (error); 792 } 793 794 /* 795 * Copy 'count' items from the list pointed to by uap->changelist. 796 */ 797 static int 798 kevent_copyin(void *arg, struct kevent *kevp, int count) 799 { 800 struct kevent_args *uap; 801 int error; 802 803 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 804 uap = (struct kevent_args *)arg; 805 806 error = copyin(uap->changelist, kevp, count * sizeof *kevp); 807 if (error == 0) 808 uap->changelist += count; 809 return (error); 810 } 811 812 int 813 kern_kevent(struct thread *td, int fd, int nchanges, int nevents, 814 struct kevent_copyops *k_ops, const struct timespec *timeout) 815 { 816 struct kevent keva[KQ_NEVENTS]; 817 struct kevent *kevp, *changes; 818 struct kqueue *kq; 819 struct file *fp; 820 int i, n, nerrors, error; 821 822 if ((error = fget(td, fd, CAP_POST_EVENT, &fp)) != 0) 823 return (error); 824 if ((error = kqueue_acquire(fp, &kq)) != 0) 825 goto done_norel; 826 827 nerrors = 0; 828 829 while (nchanges > 0) { 830 n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges; 831 error = k_ops->k_copyin(k_ops->arg, keva, n); 832 if (error) 833 goto done; 834 changes = keva; 835 for (i = 0; i < n; i++) { 836 kevp = &changes[i]; 837 if (!kevp->filter) 838 continue; 839 kevp->flags &= ~EV_SYSFLAGS; 840 error = kqueue_register(kq, kevp, td, 1); 841 if (error || (kevp->flags & EV_RECEIPT)) { 842 if (nevents != 0) { 843 kevp->flags = EV_ERROR; 844 kevp->data = error; 845 (void) k_ops->k_copyout(k_ops->arg, 846 kevp, 1); 847 nevents--; 848 nerrors++; 849 } else { 850 goto done; 851 } 852 } 853 } 854 nchanges -= n; 855 } 856 if (nerrors) { 857 td->td_retval[0] = nerrors; 858 error = 0; 859 goto done; 860 } 861 862 error = kqueue_scan(kq, nevents, k_ops, timeout, keva, td); 863 done: 864 kqueue_release(kq, 0); 865 done_norel: 866 fdrop(fp, td); 867 return (error); 868 } 869 870 int 871 kqueue_add_filteropts(int filt, struct filterops *filtops) 872 { 873 int error; 874 875 error = 0; 876 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) { 877 printf( 878 "trying to add a filterop that is out of range: %d is beyond %d\n", 879 ~filt, EVFILT_SYSCOUNT); 880 return EINVAL; 881 } 882 mtx_lock(&filterops_lock); 883 if (sysfilt_ops[~filt].for_fop != &null_filtops && 884 sysfilt_ops[~filt].for_fop != NULL) 885 error = EEXIST; 886 else { 887 sysfilt_ops[~filt].for_fop = filtops; 888 sysfilt_ops[~filt].for_refcnt = 0; 889 } 890 mtx_unlock(&filterops_lock); 891 892 return (error); 893 } 894 895 int 896 kqueue_del_filteropts(int filt) 897 { 898 int error; 899 900 error = 0; 901 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 902 return EINVAL; 903 904 mtx_lock(&filterops_lock); 905 if (sysfilt_ops[~filt].for_fop == &null_filtops || 906 sysfilt_ops[~filt].for_fop == NULL) 907 error = EINVAL; 908 else if (sysfilt_ops[~filt].for_refcnt != 0) 909 error = EBUSY; 910 else { 911 sysfilt_ops[~filt].for_fop = &null_filtops; 912 sysfilt_ops[~filt].for_refcnt = 0; 913 } 914 mtx_unlock(&filterops_lock); 915 916 return error; 917 } 918 919 static struct filterops * 920 kqueue_fo_find(int filt) 921 { 922 923 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 924 return NULL; 925 926 mtx_lock(&filterops_lock); 927 sysfilt_ops[~filt].for_refcnt++; 928 if (sysfilt_ops[~filt].for_fop == NULL) 929 sysfilt_ops[~filt].for_fop = &null_filtops; 930 mtx_unlock(&filterops_lock); 931 932 return sysfilt_ops[~filt].for_fop; 933 } 934 935 static void 936 kqueue_fo_release(int filt) 937 { 938 939 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 940 return; 941 942 mtx_lock(&filterops_lock); 943 KASSERT(sysfilt_ops[~filt].for_refcnt > 0, 944 ("filter object refcount not valid on release")); 945 sysfilt_ops[~filt].for_refcnt--; 946 mtx_unlock(&filterops_lock); 947 } 948 949 /* 950 * A ref to kq (obtained via kqueue_acquire) must be held. waitok will 951 * influence if memory allocation should wait. Make sure it is 0 if you 952 * hold any mutexes. 953 */ 954 static int 955 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, int waitok) 956 { 957 struct filterops *fops; 958 struct file *fp; 959 struct knote *kn, *tkn; 960 int error, filt, event; 961 int haskqglobal; 962 963 fp = NULL; 964 kn = NULL; 965 error = 0; 966 haskqglobal = 0; 967 968 filt = kev->filter; 969 fops = kqueue_fo_find(filt); 970 if (fops == NULL) 971 return EINVAL; 972 973 tkn = knote_alloc(waitok); /* prevent waiting with locks */ 974 975 findkn: 976 if (fops->f_isfd) { 977 KASSERT(td != NULL, ("td is NULL")); 978 error = fget(td, kev->ident, CAP_POLL_EVENT, &fp); 979 if (error) 980 goto done; 981 982 if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops, 983 kev->ident, 0) != 0) { 984 /* try again */ 985 fdrop(fp, td); 986 fp = NULL; 987 error = kqueue_expand(kq, fops, kev->ident, waitok); 988 if (error) 989 goto done; 990 goto findkn; 991 } 992 993 if (fp->f_type == DTYPE_KQUEUE) { 994 /* 995 * if we add some inteligence about what we are doing, 996 * we should be able to support events on ourselves. 997 * We need to know when we are doing this to prevent 998 * getting both the knlist lock and the kq lock since 999 * they are the same thing. 1000 */ 1001 if (fp->f_data == kq) { 1002 error = EINVAL; 1003 goto done; 1004 } 1005 1006 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1007 } 1008 1009 KQ_LOCK(kq); 1010 if (kev->ident < kq->kq_knlistsize) { 1011 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link) 1012 if (kev->filter == kn->kn_filter) 1013 break; 1014 } 1015 } else { 1016 if ((kev->flags & EV_ADD) == EV_ADD) 1017 kqueue_expand(kq, fops, kev->ident, waitok); 1018 1019 KQ_LOCK(kq); 1020 if (kq->kq_knhashmask != 0) { 1021 struct klist *list; 1022 1023 list = &kq->kq_knhash[ 1024 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)]; 1025 SLIST_FOREACH(kn, list, kn_link) 1026 if (kev->ident == kn->kn_id && 1027 kev->filter == kn->kn_filter) 1028 break; 1029 } 1030 } 1031 1032 /* knote is in the process of changing, wait for it to stablize. */ 1033 if (kn != NULL && (kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1034 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1035 kq->kq_state |= KQ_FLUXWAIT; 1036 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0); 1037 if (fp != NULL) { 1038 fdrop(fp, td); 1039 fp = NULL; 1040 } 1041 goto findkn; 1042 } 1043 1044 /* 1045 * kn now contains the matching knote, or NULL if no match 1046 */ 1047 if (kn == NULL) { 1048 if (kev->flags & EV_ADD) { 1049 kn = tkn; 1050 tkn = NULL; 1051 if (kn == NULL) { 1052 KQ_UNLOCK(kq); 1053 error = ENOMEM; 1054 goto done; 1055 } 1056 kn->kn_fp = fp; 1057 kn->kn_kq = kq; 1058 kn->kn_fop = fops; 1059 /* 1060 * apply reference counts to knote structure, and 1061 * do not release it at the end of this routine. 1062 */ 1063 fops = NULL; 1064 fp = NULL; 1065 1066 kn->kn_sfflags = kev->fflags; 1067 kn->kn_sdata = kev->data; 1068 kev->fflags = 0; 1069 kev->data = 0; 1070 kn->kn_kevent = *kev; 1071 kn->kn_kevent.flags &= ~(EV_ADD | EV_DELETE | 1072 EV_ENABLE | EV_DISABLE); 1073 kn->kn_status = KN_INFLUX|KN_DETACHED; 1074 1075 error = knote_attach(kn, kq); 1076 KQ_UNLOCK(kq); 1077 if (error != 0) { 1078 tkn = kn; 1079 goto done; 1080 } 1081 1082 if ((error = kn->kn_fop->f_attach(kn)) != 0) { 1083 knote_drop(kn, td); 1084 goto done; 1085 } 1086 KN_LIST_LOCK(kn); 1087 goto done_ev_add; 1088 } else { 1089 /* No matching knote and the EV_ADD flag is not set. */ 1090 KQ_UNLOCK(kq); 1091 error = ENOENT; 1092 goto done; 1093 } 1094 } 1095 1096 if (kev->flags & EV_DELETE) { 1097 kn->kn_status |= KN_INFLUX; 1098 KQ_UNLOCK(kq); 1099 if (!(kn->kn_status & KN_DETACHED)) 1100 kn->kn_fop->f_detach(kn); 1101 knote_drop(kn, td); 1102 goto done; 1103 } 1104 1105 /* 1106 * The user may change some filter values after the initial EV_ADD, 1107 * but doing so will not reset any filter which has already been 1108 * triggered. 1109 */ 1110 kn->kn_status |= KN_INFLUX; 1111 KQ_UNLOCK(kq); 1112 KN_LIST_LOCK(kn); 1113 kn->kn_kevent.udata = kev->udata; 1114 if (!fops->f_isfd && fops->f_touch != NULL) { 1115 fops->f_touch(kn, kev, EVENT_REGISTER); 1116 } else { 1117 kn->kn_sfflags = kev->fflags; 1118 kn->kn_sdata = kev->data; 1119 } 1120 1121 /* 1122 * We can get here with kn->kn_knlist == NULL. This can happen when 1123 * the initial attach event decides that the event is "completed" 1124 * already. i.e. filt_procattach is called on a zombie process. It 1125 * will call filt_proc which will remove it from the list, and NULL 1126 * kn_knlist. 1127 */ 1128 done_ev_add: 1129 event = kn->kn_fop->f_event(kn, 0); 1130 KQ_LOCK(kq); 1131 if (event) 1132 KNOTE_ACTIVATE(kn, 1); 1133 kn->kn_status &= ~KN_INFLUX; 1134 KN_LIST_UNLOCK(kn); 1135 1136 if ((kev->flags & EV_DISABLE) && 1137 ((kn->kn_status & KN_DISABLED) == 0)) { 1138 kn->kn_status |= KN_DISABLED; 1139 } 1140 1141 if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) { 1142 kn->kn_status &= ~KN_DISABLED; 1143 if ((kn->kn_status & KN_ACTIVE) && 1144 ((kn->kn_status & KN_QUEUED) == 0)) 1145 knote_enqueue(kn); 1146 } 1147 KQ_UNLOCK_FLUX(kq); 1148 1149 done: 1150 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1151 if (fp != NULL) 1152 fdrop(fp, td); 1153 if (tkn != NULL) 1154 knote_free(tkn); 1155 if (fops != NULL) 1156 kqueue_fo_release(filt); 1157 return (error); 1158 } 1159 1160 static int 1161 kqueue_acquire(struct file *fp, struct kqueue **kqp) 1162 { 1163 int error; 1164 struct kqueue *kq; 1165 1166 error = 0; 1167 1168 kq = fp->f_data; 1169 if (fp->f_type != DTYPE_KQUEUE || kq == NULL) 1170 return (EBADF); 1171 *kqp = kq; 1172 KQ_LOCK(kq); 1173 if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) { 1174 KQ_UNLOCK(kq); 1175 return (EBADF); 1176 } 1177 kq->kq_refcnt++; 1178 KQ_UNLOCK(kq); 1179 1180 return error; 1181 } 1182 1183 static void 1184 kqueue_release(struct kqueue *kq, int locked) 1185 { 1186 if (locked) 1187 KQ_OWNED(kq); 1188 else 1189 KQ_LOCK(kq); 1190 kq->kq_refcnt--; 1191 if (kq->kq_refcnt == 1) 1192 wakeup(&kq->kq_refcnt); 1193 if (!locked) 1194 KQ_UNLOCK(kq); 1195 } 1196 1197 static void 1198 kqueue_schedtask(struct kqueue *kq) 1199 { 1200 1201 KQ_OWNED(kq); 1202 KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN), 1203 ("scheduling kqueue task while draining")); 1204 1205 if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) { 1206 taskqueue_enqueue(taskqueue_kqueue, &kq->kq_task); 1207 kq->kq_state |= KQ_TASKSCHED; 1208 } 1209 } 1210 1211 /* 1212 * Expand the kq to make sure we have storage for fops/ident pair. 1213 * 1214 * Return 0 on success (or no work necessary), return errno on failure. 1215 * 1216 * Not calling hashinit w/ waitok (proper malloc flag) should be safe. 1217 * If kqueue_register is called from a non-fd context, there usually/should 1218 * be no locks held. 1219 */ 1220 static int 1221 kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident, 1222 int waitok) 1223 { 1224 struct klist *list, *tmp_knhash, *to_free; 1225 u_long tmp_knhashmask; 1226 int size; 1227 int fd; 1228 int mflag = waitok ? M_WAITOK : M_NOWAIT; 1229 1230 KQ_NOTOWNED(kq); 1231 1232 to_free = NULL; 1233 if (fops->f_isfd) { 1234 fd = ident; 1235 if (kq->kq_knlistsize <= fd) { 1236 size = kq->kq_knlistsize; 1237 while (size <= fd) 1238 size += KQEXTENT; 1239 list = malloc(size * sizeof(*list), M_KQUEUE, mflag); 1240 if (list == NULL) 1241 return ENOMEM; 1242 KQ_LOCK(kq); 1243 if (kq->kq_knlistsize > fd) { 1244 to_free = list; 1245 list = NULL; 1246 } else { 1247 if (kq->kq_knlist != NULL) { 1248 bcopy(kq->kq_knlist, list, 1249 kq->kq_knlistsize * sizeof(*list)); 1250 to_free = kq->kq_knlist; 1251 kq->kq_knlist = NULL; 1252 } 1253 bzero((caddr_t)list + 1254 kq->kq_knlistsize * sizeof(*list), 1255 (size - kq->kq_knlistsize) * sizeof(*list)); 1256 kq->kq_knlistsize = size; 1257 kq->kq_knlist = list; 1258 } 1259 KQ_UNLOCK(kq); 1260 } 1261 } else { 1262 if (kq->kq_knhashmask == 0) { 1263 tmp_knhash = hashinit(KN_HASHSIZE, M_KQUEUE, 1264 &tmp_knhashmask); 1265 if (tmp_knhash == NULL) 1266 return ENOMEM; 1267 KQ_LOCK(kq); 1268 if (kq->kq_knhashmask == 0) { 1269 kq->kq_knhash = tmp_knhash; 1270 kq->kq_knhashmask = tmp_knhashmask; 1271 } else { 1272 to_free = tmp_knhash; 1273 } 1274 KQ_UNLOCK(kq); 1275 } 1276 } 1277 free(to_free, M_KQUEUE); 1278 1279 KQ_NOTOWNED(kq); 1280 return 0; 1281 } 1282 1283 static void 1284 kqueue_task(void *arg, int pending) 1285 { 1286 struct kqueue *kq; 1287 int haskqglobal; 1288 1289 haskqglobal = 0; 1290 kq = arg; 1291 1292 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1293 KQ_LOCK(kq); 1294 1295 KNOTE_LOCKED(&kq->kq_sel.si_note, 0); 1296 1297 kq->kq_state &= ~KQ_TASKSCHED; 1298 if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) { 1299 wakeup(&kq->kq_state); 1300 } 1301 KQ_UNLOCK(kq); 1302 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1303 } 1304 1305 /* 1306 * Scan, update kn_data (if not ONESHOT), and copyout triggered events. 1307 * We treat KN_MARKER knotes as if they are INFLUX. 1308 */ 1309 static int 1310 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops, 1311 const struct timespec *tsp, struct kevent *keva, struct thread *td) 1312 { 1313 struct kevent *kevp; 1314 struct timeval atv, rtv, ttv; 1315 struct knote *kn, *marker; 1316 int count, timeout, nkev, error, influx; 1317 int haskqglobal, touch; 1318 1319 count = maxevents; 1320 nkev = 0; 1321 error = 0; 1322 haskqglobal = 0; 1323 1324 if (maxevents == 0) 1325 goto done_nl; 1326 1327 if (tsp != NULL) { 1328 TIMESPEC_TO_TIMEVAL(&atv, tsp); 1329 if (itimerfix(&atv)) { 1330 error = EINVAL; 1331 goto done_nl; 1332 } 1333 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) 1334 timeout = -1; 1335 else 1336 timeout = atv.tv_sec > 24 * 60 * 60 ? 1337 24 * 60 * 60 * hz : tvtohz(&atv); 1338 getmicrouptime(&rtv); 1339 timevaladd(&atv, &rtv); 1340 } else { 1341 atv.tv_sec = 0; 1342 atv.tv_usec = 0; 1343 timeout = 0; 1344 } 1345 marker = knote_alloc(1); 1346 if (marker == NULL) { 1347 error = ENOMEM; 1348 goto done_nl; 1349 } 1350 marker->kn_status = KN_MARKER; 1351 KQ_LOCK(kq); 1352 goto start; 1353 1354 retry: 1355 if (atv.tv_sec || atv.tv_usec) { 1356 getmicrouptime(&rtv); 1357 if (timevalcmp(&rtv, &atv, >=)) 1358 goto done; 1359 ttv = atv; 1360 timevalsub(&ttv, &rtv); 1361 timeout = ttv.tv_sec > 24 * 60 * 60 ? 1362 24 * 60 * 60 * hz : tvtohz(&ttv); 1363 } 1364 1365 start: 1366 kevp = keva; 1367 if (kq->kq_count == 0) { 1368 if (timeout < 0) { 1369 error = EWOULDBLOCK; 1370 } else { 1371 kq->kq_state |= KQ_SLEEP; 1372 error = msleep(kq, &kq->kq_lock, PSOCK | PCATCH, 1373 "kqread", timeout); 1374 } 1375 if (error == 0) 1376 goto retry; 1377 /* don't restart after signals... */ 1378 if (error == ERESTART) 1379 error = EINTR; 1380 else if (error == EWOULDBLOCK) 1381 error = 0; 1382 goto done; 1383 } 1384 1385 TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); 1386 influx = 0; 1387 while (count) { 1388 KQ_OWNED(kq); 1389 kn = TAILQ_FIRST(&kq->kq_head); 1390 1391 if ((kn->kn_status == KN_MARKER && kn != marker) || 1392 (kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1393 if (influx) { 1394 influx = 0; 1395 KQ_FLUX_WAKEUP(kq); 1396 } 1397 kq->kq_state |= KQ_FLUXWAIT; 1398 error = msleep(kq, &kq->kq_lock, PSOCK, 1399 "kqflxwt", 0); 1400 continue; 1401 } 1402 1403 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1404 if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) { 1405 kn->kn_status &= ~KN_QUEUED; 1406 kq->kq_count--; 1407 continue; 1408 } 1409 if (kn == marker) { 1410 KQ_FLUX_WAKEUP(kq); 1411 if (count == maxevents) 1412 goto retry; 1413 goto done; 1414 } 1415 KASSERT((kn->kn_status & KN_INFLUX) == 0, 1416 ("KN_INFLUX set when not suppose to be")); 1417 1418 if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) { 1419 kn->kn_status &= ~KN_QUEUED; 1420 kn->kn_status |= KN_INFLUX; 1421 kq->kq_count--; 1422 KQ_UNLOCK(kq); 1423 /* 1424 * We don't need to lock the list since we've marked 1425 * it _INFLUX. 1426 */ 1427 *kevp = kn->kn_kevent; 1428 if (!(kn->kn_status & KN_DETACHED)) 1429 kn->kn_fop->f_detach(kn); 1430 knote_drop(kn, td); 1431 KQ_LOCK(kq); 1432 kn = NULL; 1433 } else { 1434 kn->kn_status |= KN_INFLUX; 1435 KQ_UNLOCK(kq); 1436 if ((kn->kn_status & KN_KQUEUE) == KN_KQUEUE) 1437 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1438 KN_LIST_LOCK(kn); 1439 if (kn->kn_fop->f_event(kn, 0) == 0) { 1440 KQ_LOCK(kq); 1441 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1442 kn->kn_status &= 1443 ~(KN_QUEUED | KN_ACTIVE | KN_INFLUX); 1444 kq->kq_count--; 1445 KN_LIST_UNLOCK(kn); 1446 influx = 1; 1447 continue; 1448 } 1449 touch = (!kn->kn_fop->f_isfd && 1450 kn->kn_fop->f_touch != NULL); 1451 if (touch) 1452 kn->kn_fop->f_touch(kn, kevp, EVENT_PROCESS); 1453 else 1454 *kevp = kn->kn_kevent; 1455 KQ_LOCK(kq); 1456 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1457 if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) { 1458 /* 1459 * Manually clear knotes who weren't 1460 * 'touch'ed. 1461 */ 1462 if (touch == 0 && kn->kn_flags & EV_CLEAR) { 1463 kn->kn_data = 0; 1464 kn->kn_fflags = 0; 1465 } 1466 if (kn->kn_flags & EV_DISPATCH) 1467 kn->kn_status |= KN_DISABLED; 1468 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 1469 kq->kq_count--; 1470 } else 1471 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 1472 1473 kn->kn_status &= ~(KN_INFLUX); 1474 KN_LIST_UNLOCK(kn); 1475 influx = 1; 1476 } 1477 1478 /* we are returning a copy to the user */ 1479 kevp++; 1480 nkev++; 1481 count--; 1482 1483 if (nkev == KQ_NEVENTS) { 1484 influx = 0; 1485 KQ_UNLOCK_FLUX(kq); 1486 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1487 nkev = 0; 1488 kevp = keva; 1489 KQ_LOCK(kq); 1490 if (error) 1491 break; 1492 } 1493 } 1494 TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); 1495 done: 1496 KQ_OWNED(kq); 1497 KQ_UNLOCK_FLUX(kq); 1498 knote_free(marker); 1499 done_nl: 1500 KQ_NOTOWNED(kq); 1501 if (nkev != 0) 1502 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1503 td->td_retval[0] = maxevents - count; 1504 return (error); 1505 } 1506 1507 /* 1508 * XXX 1509 * This could be expanded to call kqueue_scan, if desired. 1510 */ 1511 /*ARGSUSED*/ 1512 static int 1513 kqueue_read(struct file *fp, struct uio *uio, struct ucred *active_cred, 1514 int flags, struct thread *td) 1515 { 1516 return (ENXIO); 1517 } 1518 1519 /*ARGSUSED*/ 1520 static int 1521 kqueue_write(struct file *fp, struct uio *uio, struct ucred *active_cred, 1522 int flags, struct thread *td) 1523 { 1524 return (ENXIO); 1525 } 1526 1527 /*ARGSUSED*/ 1528 static int 1529 kqueue_truncate(struct file *fp, off_t length, struct ucred *active_cred, 1530 struct thread *td) 1531 { 1532 1533 return (EINVAL); 1534 } 1535 1536 /*ARGSUSED*/ 1537 static int 1538 kqueue_ioctl(struct file *fp, u_long cmd, void *data, 1539 struct ucred *active_cred, struct thread *td) 1540 { 1541 /* 1542 * Enabling sigio causes two major problems: 1543 * 1) infinite recursion: 1544 * Synopsys: kevent is being used to track signals and have FIOASYNC 1545 * set. On receipt of a signal this will cause a kqueue to recurse 1546 * into itself over and over. Sending the sigio causes the kqueue 1547 * to become ready, which in turn posts sigio again, forever. 1548 * Solution: this can be solved by setting a flag in the kqueue that 1549 * we have a SIGIO in progress. 1550 * 2) locking problems: 1551 * Synopsys: Kqueue is a leaf subsystem, but adding signalling puts 1552 * us above the proc and pgrp locks. 1553 * Solution: Post a signal using an async mechanism, being sure to 1554 * record a generation count in the delivery so that we do not deliver 1555 * a signal to the wrong process. 1556 * 1557 * Note, these two mechanisms are somewhat mutually exclusive! 1558 */ 1559 #if 0 1560 struct kqueue *kq; 1561 1562 kq = fp->f_data; 1563 switch (cmd) { 1564 case FIOASYNC: 1565 if (*(int *)data) { 1566 kq->kq_state |= KQ_ASYNC; 1567 } else { 1568 kq->kq_state &= ~KQ_ASYNC; 1569 } 1570 return (0); 1571 1572 case FIOSETOWN: 1573 return (fsetown(*(int *)data, &kq->kq_sigio)); 1574 1575 case FIOGETOWN: 1576 *(int *)data = fgetown(&kq->kq_sigio); 1577 return (0); 1578 } 1579 #endif 1580 1581 return (ENOTTY); 1582 } 1583 1584 /*ARGSUSED*/ 1585 static int 1586 kqueue_poll(struct file *fp, int events, struct ucred *active_cred, 1587 struct thread *td) 1588 { 1589 struct kqueue *kq; 1590 int revents = 0; 1591 int error; 1592 1593 if ((error = kqueue_acquire(fp, &kq))) 1594 return POLLERR; 1595 1596 KQ_LOCK(kq); 1597 if (events & (POLLIN | POLLRDNORM)) { 1598 if (kq->kq_count) { 1599 revents |= events & (POLLIN | POLLRDNORM); 1600 } else { 1601 selrecord(td, &kq->kq_sel); 1602 if (SEL_WAITING(&kq->kq_sel)) 1603 kq->kq_state |= KQ_SEL; 1604 } 1605 } 1606 kqueue_release(kq, 1); 1607 KQ_UNLOCK(kq); 1608 return (revents); 1609 } 1610 1611 /*ARGSUSED*/ 1612 static int 1613 kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred, 1614 struct thread *td) 1615 { 1616 1617 bzero((void *)st, sizeof *st); 1618 /* 1619 * We no longer return kq_count because the unlocked value is useless. 1620 * If you spent all this time getting the count, why not spend your 1621 * syscall better by calling kevent? 1622 * 1623 * XXX - This is needed for libc_r. 1624 */ 1625 st->st_mode = S_IFIFO; 1626 return (0); 1627 } 1628 1629 /*ARGSUSED*/ 1630 static int 1631 kqueue_close(struct file *fp, struct thread *td) 1632 { 1633 struct kqueue *kq = fp->f_data; 1634 struct filedesc *fdp; 1635 struct knote *kn; 1636 int i; 1637 int error; 1638 1639 if ((error = kqueue_acquire(fp, &kq))) 1640 return error; 1641 1642 KQ_LOCK(kq); 1643 1644 KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING, 1645 ("kqueue already closing")); 1646 kq->kq_state |= KQ_CLOSING; 1647 if (kq->kq_refcnt > 1) 1648 msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0); 1649 1650 KASSERT(kq->kq_refcnt == 1, ("other refs are out there!")); 1651 fdp = kq->kq_fdp; 1652 1653 KASSERT(knlist_empty(&kq->kq_sel.si_note), 1654 ("kqueue's knlist not empty")); 1655 1656 for (i = 0; i < kq->kq_knlistsize; i++) { 1657 while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) { 1658 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1659 kq->kq_state |= KQ_FLUXWAIT; 1660 msleep(kq, &kq->kq_lock, PSOCK, "kqclo1", 0); 1661 continue; 1662 } 1663 kn->kn_status |= KN_INFLUX; 1664 KQ_UNLOCK(kq); 1665 if (!(kn->kn_status & KN_DETACHED)) 1666 kn->kn_fop->f_detach(kn); 1667 knote_drop(kn, td); 1668 KQ_LOCK(kq); 1669 } 1670 } 1671 if (kq->kq_knhashmask != 0) { 1672 for (i = 0; i <= kq->kq_knhashmask; i++) { 1673 while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) { 1674 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1675 kq->kq_state |= KQ_FLUXWAIT; 1676 msleep(kq, &kq->kq_lock, PSOCK, 1677 "kqclo2", 0); 1678 continue; 1679 } 1680 kn->kn_status |= KN_INFLUX; 1681 KQ_UNLOCK(kq); 1682 if (!(kn->kn_status & KN_DETACHED)) 1683 kn->kn_fop->f_detach(kn); 1684 knote_drop(kn, td); 1685 KQ_LOCK(kq); 1686 } 1687 } 1688 } 1689 1690 if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) { 1691 kq->kq_state |= KQ_TASKDRAIN; 1692 msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0); 1693 } 1694 1695 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 1696 selwakeuppri(&kq->kq_sel, PSOCK); 1697 if (!SEL_WAITING(&kq->kq_sel)) 1698 kq->kq_state &= ~KQ_SEL; 1699 } 1700 1701 KQ_UNLOCK(kq); 1702 1703 FILEDESC_XLOCK(fdp); 1704 SLIST_REMOVE(&fdp->fd_kqlist, kq, kqueue, kq_list); 1705 FILEDESC_XUNLOCK(fdp); 1706 1707 seldrain(&kq->kq_sel); 1708 knlist_destroy(&kq->kq_sel.si_note); 1709 mtx_destroy(&kq->kq_lock); 1710 kq->kq_fdp = NULL; 1711 1712 if (kq->kq_knhash != NULL) 1713 free(kq->kq_knhash, M_KQUEUE); 1714 if (kq->kq_knlist != NULL) 1715 free(kq->kq_knlist, M_KQUEUE); 1716 1717 funsetown(&kq->kq_sigio); 1718 free(kq, M_KQUEUE); 1719 fp->f_data = NULL; 1720 1721 return (0); 1722 } 1723 1724 static void 1725 kqueue_wakeup(struct kqueue *kq) 1726 { 1727 KQ_OWNED(kq); 1728 1729 if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) { 1730 kq->kq_state &= ~KQ_SLEEP; 1731 wakeup(kq); 1732 } 1733 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 1734 selwakeuppri(&kq->kq_sel, PSOCK); 1735 if (!SEL_WAITING(&kq->kq_sel)) 1736 kq->kq_state &= ~KQ_SEL; 1737 } 1738 if (!knlist_empty(&kq->kq_sel.si_note)) 1739 kqueue_schedtask(kq); 1740 if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) { 1741 pgsigio(&kq->kq_sigio, SIGIO, 0); 1742 } 1743 } 1744 1745 /* 1746 * Walk down a list of knotes, activating them if their event has triggered. 1747 * 1748 * There is a possibility to optimize in the case of one kq watching another. 1749 * Instead of scheduling a task to wake it up, you could pass enough state 1750 * down the chain to make up the parent kqueue. Make this code functional 1751 * first. 1752 */ 1753 void 1754 knote(struct knlist *list, long hint, int lockflags) 1755 { 1756 struct kqueue *kq; 1757 struct knote *kn; 1758 int error; 1759 1760 if (list == NULL) 1761 return; 1762 1763 KNL_ASSERT_LOCK(list, lockflags & KNF_LISTLOCKED); 1764 1765 if ((lockflags & KNF_LISTLOCKED) == 0) 1766 list->kl_lock(list->kl_lockarg); 1767 1768 /* 1769 * If we unlock the list lock (and set KN_INFLUX), we can eliminate 1770 * the kqueue scheduling, but this will introduce four 1771 * lock/unlock's for each knote to test. If we do, continue to use 1772 * SLIST_FOREACH, SLIST_FOREACH_SAFE is not safe in our case, it is 1773 * only safe if you want to remove the current item, which we are 1774 * not doing. 1775 */ 1776 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { 1777 kq = kn->kn_kq; 1778 if ((kn->kn_status & KN_INFLUX) != KN_INFLUX) { 1779 KQ_LOCK(kq); 1780 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1781 KQ_UNLOCK(kq); 1782 } else if ((lockflags & KNF_NOKQLOCK) != 0) { 1783 kn->kn_status |= KN_INFLUX; 1784 KQ_UNLOCK(kq); 1785 error = kn->kn_fop->f_event(kn, hint); 1786 KQ_LOCK(kq); 1787 kn->kn_status &= ~KN_INFLUX; 1788 if (error) 1789 KNOTE_ACTIVATE(kn, 1); 1790 KQ_UNLOCK_FLUX(kq); 1791 } else { 1792 kn->kn_status |= KN_HASKQLOCK; 1793 if (kn->kn_fop->f_event(kn, hint)) 1794 KNOTE_ACTIVATE(kn, 1); 1795 kn->kn_status &= ~KN_HASKQLOCK; 1796 KQ_UNLOCK(kq); 1797 } 1798 } 1799 kq = NULL; 1800 } 1801 if ((lockflags & KNF_LISTLOCKED) == 0) 1802 list->kl_unlock(list->kl_lockarg); 1803 } 1804 1805 /* 1806 * add a knote to a knlist 1807 */ 1808 void 1809 knlist_add(struct knlist *knl, struct knote *kn, int islocked) 1810 { 1811 KNL_ASSERT_LOCK(knl, islocked); 1812 KQ_NOTOWNED(kn->kn_kq); 1813 KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) == 1814 (KN_INFLUX|KN_DETACHED), ("knote not KN_INFLUX and KN_DETACHED")); 1815 if (!islocked) 1816 knl->kl_lock(knl->kl_lockarg); 1817 SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext); 1818 if (!islocked) 1819 knl->kl_unlock(knl->kl_lockarg); 1820 KQ_LOCK(kn->kn_kq); 1821 kn->kn_knlist = knl; 1822 kn->kn_status &= ~KN_DETACHED; 1823 KQ_UNLOCK(kn->kn_kq); 1824 } 1825 1826 static void 1827 knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked, int kqislocked) 1828 { 1829 KASSERT(!(!!kqislocked && !knlislocked), ("kq locked w/o knl locked")); 1830 KNL_ASSERT_LOCK(knl, knlislocked); 1831 mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED); 1832 if (!kqislocked) 1833 KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) == KN_INFLUX, 1834 ("knlist_remove called w/o knote being KN_INFLUX or already removed")); 1835 if (!knlislocked) 1836 knl->kl_lock(knl->kl_lockarg); 1837 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext); 1838 kn->kn_knlist = NULL; 1839 if (!knlislocked) 1840 knl->kl_unlock(knl->kl_lockarg); 1841 if (!kqislocked) 1842 KQ_LOCK(kn->kn_kq); 1843 kn->kn_status |= KN_DETACHED; 1844 if (!kqislocked) 1845 KQ_UNLOCK(kn->kn_kq); 1846 } 1847 1848 /* 1849 * remove all knotes from a specified klist 1850 */ 1851 void 1852 knlist_remove(struct knlist *knl, struct knote *kn, int islocked) 1853 { 1854 1855 knlist_remove_kq(knl, kn, islocked, 0); 1856 } 1857 1858 /* 1859 * remove knote from a specified klist while in f_event handler. 1860 */ 1861 void 1862 knlist_remove_inevent(struct knlist *knl, struct knote *kn) 1863 { 1864 1865 knlist_remove_kq(knl, kn, 1, 1866 (kn->kn_status & KN_HASKQLOCK) == KN_HASKQLOCK); 1867 } 1868 1869 int 1870 knlist_empty(struct knlist *knl) 1871 { 1872 KNL_ASSERT_LOCKED(knl); 1873 return SLIST_EMPTY(&knl->kl_list); 1874 } 1875 1876 static struct mtx knlist_lock; 1877 MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects", 1878 MTX_DEF); 1879 static void knlist_mtx_lock(void *arg); 1880 static void knlist_mtx_unlock(void *arg); 1881 1882 static void 1883 knlist_mtx_lock(void *arg) 1884 { 1885 mtx_lock((struct mtx *)arg); 1886 } 1887 1888 static void 1889 knlist_mtx_unlock(void *arg) 1890 { 1891 mtx_unlock((struct mtx *)arg); 1892 } 1893 1894 static void 1895 knlist_mtx_assert_locked(void *arg) 1896 { 1897 mtx_assert((struct mtx *)arg, MA_OWNED); 1898 } 1899 1900 static void 1901 knlist_mtx_assert_unlocked(void *arg) 1902 { 1903 mtx_assert((struct mtx *)arg, MA_NOTOWNED); 1904 } 1905 1906 void 1907 knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *), 1908 void (*kl_unlock)(void *), 1909 void (*kl_assert_locked)(void *), void (*kl_assert_unlocked)(void *)) 1910 { 1911 1912 if (lock == NULL) 1913 knl->kl_lockarg = &knlist_lock; 1914 else 1915 knl->kl_lockarg = lock; 1916 1917 if (kl_lock == NULL) 1918 knl->kl_lock = knlist_mtx_lock; 1919 else 1920 knl->kl_lock = kl_lock; 1921 if (kl_unlock == NULL) 1922 knl->kl_unlock = knlist_mtx_unlock; 1923 else 1924 knl->kl_unlock = kl_unlock; 1925 if (kl_assert_locked == NULL) 1926 knl->kl_assert_locked = knlist_mtx_assert_locked; 1927 else 1928 knl->kl_assert_locked = kl_assert_locked; 1929 if (kl_assert_unlocked == NULL) 1930 knl->kl_assert_unlocked = knlist_mtx_assert_unlocked; 1931 else 1932 knl->kl_assert_unlocked = kl_assert_unlocked; 1933 1934 SLIST_INIT(&knl->kl_list); 1935 } 1936 1937 void 1938 knlist_init_mtx(struct knlist *knl, struct mtx *lock) 1939 { 1940 1941 knlist_init(knl, lock, NULL, NULL, NULL, NULL); 1942 } 1943 1944 void 1945 knlist_destroy(struct knlist *knl) 1946 { 1947 1948 #ifdef INVARIANTS 1949 /* 1950 * if we run across this error, we need to find the offending 1951 * driver and have it call knlist_clear. 1952 */ 1953 if (!SLIST_EMPTY(&knl->kl_list)) 1954 printf("WARNING: destroying knlist w/ knotes on it!\n"); 1955 #endif 1956 1957 knl->kl_lockarg = knl->kl_lock = knl->kl_unlock = NULL; 1958 SLIST_INIT(&knl->kl_list); 1959 } 1960 1961 /* 1962 * Even if we are locked, we may need to drop the lock to allow any influx 1963 * knotes time to "settle". 1964 */ 1965 void 1966 knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn) 1967 { 1968 struct knote *kn, *kn2; 1969 struct kqueue *kq; 1970 1971 if (islocked) 1972 KNL_ASSERT_LOCKED(knl); 1973 else { 1974 KNL_ASSERT_UNLOCKED(knl); 1975 again: /* need to reacquire lock since we have dropped it */ 1976 knl->kl_lock(knl->kl_lockarg); 1977 } 1978 1979 SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) { 1980 kq = kn->kn_kq; 1981 KQ_LOCK(kq); 1982 if ((kn->kn_status & KN_INFLUX)) { 1983 KQ_UNLOCK(kq); 1984 continue; 1985 } 1986 knlist_remove_kq(knl, kn, 1, 1); 1987 if (killkn) { 1988 kn->kn_status |= KN_INFLUX | KN_DETACHED; 1989 KQ_UNLOCK(kq); 1990 knote_drop(kn, td); 1991 } else { 1992 /* Make sure cleared knotes disappear soon */ 1993 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 1994 KQ_UNLOCK(kq); 1995 } 1996 kq = NULL; 1997 } 1998 1999 if (!SLIST_EMPTY(&knl->kl_list)) { 2000 /* there are still KN_INFLUX remaining */ 2001 kn = SLIST_FIRST(&knl->kl_list); 2002 kq = kn->kn_kq; 2003 KQ_LOCK(kq); 2004 KASSERT(kn->kn_status & KN_INFLUX, 2005 ("knote removed w/o list lock")); 2006 knl->kl_unlock(knl->kl_lockarg); 2007 kq->kq_state |= KQ_FLUXWAIT; 2008 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0); 2009 kq = NULL; 2010 goto again; 2011 } 2012 2013 if (islocked) 2014 KNL_ASSERT_LOCKED(knl); 2015 else { 2016 knl->kl_unlock(knl->kl_lockarg); 2017 KNL_ASSERT_UNLOCKED(knl); 2018 } 2019 } 2020 2021 /* 2022 * Remove all knotes referencing a specified fd must be called with FILEDESC 2023 * lock. This prevents a race where a new fd comes along and occupies the 2024 * entry and we attach a knote to the fd. 2025 */ 2026 void 2027 knote_fdclose(struct thread *td, int fd) 2028 { 2029 struct filedesc *fdp = td->td_proc->p_fd; 2030 struct kqueue *kq; 2031 struct knote *kn; 2032 int influx; 2033 2034 FILEDESC_XLOCK_ASSERT(fdp); 2035 2036 /* 2037 * We shouldn't have to worry about new kevents appearing on fd 2038 * since filedesc is locked. 2039 */ 2040 SLIST_FOREACH(kq, &fdp->fd_kqlist, kq_list) { 2041 KQ_LOCK(kq); 2042 2043 again: 2044 influx = 0; 2045 while (kq->kq_knlistsize > fd && 2046 (kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) { 2047 if (kn->kn_status & KN_INFLUX) { 2048 /* someone else might be waiting on our knote */ 2049 if (influx) 2050 wakeup(kq); 2051 kq->kq_state |= KQ_FLUXWAIT; 2052 msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0); 2053 goto again; 2054 } 2055 kn->kn_status |= KN_INFLUX; 2056 KQ_UNLOCK(kq); 2057 if (!(kn->kn_status & KN_DETACHED)) 2058 kn->kn_fop->f_detach(kn); 2059 knote_drop(kn, td); 2060 influx = 1; 2061 KQ_LOCK(kq); 2062 } 2063 KQ_UNLOCK_FLUX(kq); 2064 } 2065 } 2066 2067 static int 2068 knote_attach(struct knote *kn, struct kqueue *kq) 2069 { 2070 struct klist *list; 2071 2072 KASSERT(kn->kn_status & KN_INFLUX, ("knote not marked INFLUX")); 2073 KQ_OWNED(kq); 2074 2075 if (kn->kn_fop->f_isfd) { 2076 if (kn->kn_id >= kq->kq_knlistsize) 2077 return ENOMEM; 2078 list = &kq->kq_knlist[kn->kn_id]; 2079 } else { 2080 if (kq->kq_knhash == NULL) 2081 return ENOMEM; 2082 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2083 } 2084 2085 SLIST_INSERT_HEAD(list, kn, kn_link); 2086 2087 return 0; 2088 } 2089 2090 /* 2091 * knote must already have been detached using the f_detach method. 2092 * no lock need to be held, it is assumed that the KN_INFLUX flag is set 2093 * to prevent other removal. 2094 */ 2095 static void 2096 knote_drop(struct knote *kn, struct thread *td) 2097 { 2098 struct kqueue *kq; 2099 struct klist *list; 2100 2101 kq = kn->kn_kq; 2102 2103 KQ_NOTOWNED(kq); 2104 KASSERT((kn->kn_status & KN_INFLUX) == KN_INFLUX, 2105 ("knote_drop called without KN_INFLUX set in kn_status")); 2106 2107 KQ_LOCK(kq); 2108 if (kn->kn_fop->f_isfd) 2109 list = &kq->kq_knlist[kn->kn_id]; 2110 else 2111 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2112 2113 if (!SLIST_EMPTY(list)) 2114 SLIST_REMOVE(list, kn, knote, kn_link); 2115 if (kn->kn_status & KN_QUEUED) 2116 knote_dequeue(kn); 2117 KQ_UNLOCK_FLUX(kq); 2118 2119 if (kn->kn_fop->f_isfd) { 2120 fdrop(kn->kn_fp, td); 2121 kn->kn_fp = NULL; 2122 } 2123 kqueue_fo_release(kn->kn_kevent.filter); 2124 kn->kn_fop = NULL; 2125 knote_free(kn); 2126 } 2127 2128 static void 2129 knote_enqueue(struct knote *kn) 2130 { 2131 struct kqueue *kq = kn->kn_kq; 2132 2133 KQ_OWNED(kn->kn_kq); 2134 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 2135 2136 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2137 kn->kn_status |= KN_QUEUED; 2138 kq->kq_count++; 2139 kqueue_wakeup(kq); 2140 } 2141 2142 static void 2143 knote_dequeue(struct knote *kn) 2144 { 2145 struct kqueue *kq = kn->kn_kq; 2146 2147 KQ_OWNED(kn->kn_kq); 2148 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 2149 2150 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 2151 kn->kn_status &= ~KN_QUEUED; 2152 kq->kq_count--; 2153 } 2154 2155 static void 2156 knote_init(void) 2157 { 2158 2159 knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL, 2160 NULL, NULL, UMA_ALIGN_PTR, 0); 2161 } 2162 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL); 2163 2164 static struct knote * 2165 knote_alloc(int waitok) 2166 { 2167 return ((struct knote *)uma_zalloc(knote_zone, 2168 (waitok ? M_WAITOK : M_NOWAIT)|M_ZERO)); 2169 } 2170 2171 static void 2172 knote_free(struct knote *kn) 2173 { 2174 if (kn != NULL) 2175 uma_zfree(knote_zone, kn); 2176 } 2177 2178 /* 2179 * Register the kev w/ the kq specified by fd. 2180 */ 2181 int 2182 kqfd_register(int fd, struct kevent *kev, struct thread *td, int waitok) 2183 { 2184 struct kqueue *kq; 2185 struct file *fp; 2186 int error; 2187 2188 if ((error = fget(td, fd, CAP_POST_EVENT, &fp)) != 0) 2189 return (error); 2190 if ((error = kqueue_acquire(fp, &kq)) != 0) 2191 goto noacquire; 2192 2193 error = kqueue_register(kq, kev, td, waitok); 2194 2195 kqueue_release(kq, 0); 2196 2197 noacquire: 2198 fdrop(fp, td); 2199 2200 return error; 2201 } 2202