1 /*- 2 * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org> 3 * Copyright 2004 John-Mark Gurney <jmg@FreeBSD.org> 4 * Copyright (c) 2009 Apple, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include "opt_ktrace.h" 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/capability.h> 37 #include <sys/kernel.h> 38 #include <sys/lock.h> 39 #include <sys/mutex.h> 40 #include <sys/rwlock.h> 41 #include <sys/proc.h> 42 #include <sys/malloc.h> 43 #include <sys/unistd.h> 44 #include <sys/file.h> 45 #include <sys/filedesc.h> 46 #include <sys/filio.h> 47 #include <sys/fcntl.h> 48 #include <sys/kthread.h> 49 #include <sys/selinfo.h> 50 #include <sys/stdatomic.h> 51 #include <sys/queue.h> 52 #include <sys/event.h> 53 #include <sys/eventvar.h> 54 #include <sys/poll.h> 55 #include <sys/protosw.h> 56 #include <sys/sigio.h> 57 #include <sys/signalvar.h> 58 #include <sys/socket.h> 59 #include <sys/socketvar.h> 60 #include <sys/stat.h> 61 #include <sys/sysctl.h> 62 #include <sys/sysproto.h> 63 #include <sys/syscallsubr.h> 64 #include <sys/taskqueue.h> 65 #include <sys/uio.h> 66 #ifdef KTRACE 67 #include <sys/ktrace.h> 68 #endif 69 70 #include <vm/uma.h> 71 72 static MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system"); 73 74 /* 75 * This lock is used if multiple kq locks are required. This possibly 76 * should be made into a per proc lock. 77 */ 78 static struct mtx kq_global; 79 MTX_SYSINIT(kq_global, &kq_global, "kqueue order", MTX_DEF); 80 #define KQ_GLOBAL_LOCK(lck, haslck) do { \ 81 if (!haslck) \ 82 mtx_lock(lck); \ 83 haslck = 1; \ 84 } while (0) 85 #define KQ_GLOBAL_UNLOCK(lck, haslck) do { \ 86 if (haslck) \ 87 mtx_unlock(lck); \ 88 haslck = 0; \ 89 } while (0) 90 91 TASKQUEUE_DEFINE_THREAD(kqueue); 92 93 static int kevent_copyout(void *arg, struct kevent *kevp, int count); 94 static int kevent_copyin(void *arg, struct kevent *kevp, int count); 95 static int kqueue_register(struct kqueue *kq, struct kevent *kev, 96 struct thread *td, int waitok); 97 static int kqueue_acquire(struct file *fp, struct kqueue **kqp); 98 static void kqueue_release(struct kqueue *kq, int locked); 99 static int kqueue_expand(struct kqueue *kq, struct filterops *fops, 100 uintptr_t ident, int waitok); 101 static void kqueue_task(void *arg, int pending); 102 static int kqueue_scan(struct kqueue *kq, int maxevents, 103 struct kevent_copyops *k_ops, 104 const struct timespec *timeout, 105 struct kevent *keva, struct thread *td); 106 static void kqueue_wakeup(struct kqueue *kq); 107 static struct filterops *kqueue_fo_find(int filt); 108 static void kqueue_fo_release(int filt); 109 110 static fo_rdwr_t kqueue_read; 111 static fo_rdwr_t kqueue_write; 112 static fo_truncate_t kqueue_truncate; 113 static fo_ioctl_t kqueue_ioctl; 114 static fo_poll_t kqueue_poll; 115 static fo_kqfilter_t kqueue_kqfilter; 116 static fo_stat_t kqueue_stat; 117 static fo_close_t kqueue_close; 118 119 static struct fileops kqueueops = { 120 .fo_read = kqueue_read, 121 .fo_write = kqueue_write, 122 .fo_truncate = kqueue_truncate, 123 .fo_ioctl = kqueue_ioctl, 124 .fo_poll = kqueue_poll, 125 .fo_kqfilter = kqueue_kqfilter, 126 .fo_stat = kqueue_stat, 127 .fo_close = kqueue_close, 128 .fo_chmod = invfo_chmod, 129 .fo_chown = invfo_chown, 130 .fo_sendfile = invfo_sendfile, 131 }; 132 133 static int knote_attach(struct knote *kn, struct kqueue *kq); 134 static void knote_drop(struct knote *kn, struct thread *td); 135 static void knote_enqueue(struct knote *kn); 136 static void knote_dequeue(struct knote *kn); 137 static void knote_init(void); 138 static struct knote *knote_alloc(int waitok); 139 static void knote_free(struct knote *kn); 140 141 static void filt_kqdetach(struct knote *kn); 142 static int filt_kqueue(struct knote *kn, long hint); 143 static int filt_procattach(struct knote *kn); 144 static void filt_procdetach(struct knote *kn); 145 static int filt_proc(struct knote *kn, long hint); 146 static int filt_fileattach(struct knote *kn); 147 static void filt_timerexpire(void *knx); 148 static int filt_timerattach(struct knote *kn); 149 static void filt_timerdetach(struct knote *kn); 150 static int filt_timer(struct knote *kn, long hint); 151 static int filt_userattach(struct knote *kn); 152 static void filt_userdetach(struct knote *kn); 153 static int filt_user(struct knote *kn, long hint); 154 static void filt_usertouch(struct knote *kn, struct kevent *kev, 155 u_long type); 156 157 static struct filterops file_filtops = { 158 .f_isfd = 1, 159 .f_attach = filt_fileattach, 160 }; 161 static struct filterops kqread_filtops = { 162 .f_isfd = 1, 163 .f_detach = filt_kqdetach, 164 .f_event = filt_kqueue, 165 }; 166 /* XXX - move to kern_proc.c? */ 167 static struct filterops proc_filtops = { 168 .f_isfd = 0, 169 .f_attach = filt_procattach, 170 .f_detach = filt_procdetach, 171 .f_event = filt_proc, 172 }; 173 static struct filterops timer_filtops = { 174 .f_isfd = 0, 175 .f_attach = filt_timerattach, 176 .f_detach = filt_timerdetach, 177 .f_event = filt_timer, 178 }; 179 static struct filterops user_filtops = { 180 .f_attach = filt_userattach, 181 .f_detach = filt_userdetach, 182 .f_event = filt_user, 183 .f_touch = filt_usertouch, 184 }; 185 186 static uma_zone_t knote_zone; 187 static atomic_uint kq_ncallouts = ATOMIC_VAR_INIT(0); 188 static unsigned int kq_calloutmax = 4 * 1024; 189 SYSCTL_UINT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW, 190 &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue"); 191 192 /* XXX - ensure not KN_INFLUX?? */ 193 #define KNOTE_ACTIVATE(kn, islock) do { \ 194 if ((islock)) \ 195 mtx_assert(&(kn)->kn_kq->kq_lock, MA_OWNED); \ 196 else \ 197 KQ_LOCK((kn)->kn_kq); \ 198 (kn)->kn_status |= KN_ACTIVE; \ 199 if (((kn)->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 200 knote_enqueue((kn)); \ 201 if (!(islock)) \ 202 KQ_UNLOCK((kn)->kn_kq); \ 203 } while(0) 204 #define KQ_LOCK(kq) do { \ 205 mtx_lock(&(kq)->kq_lock); \ 206 } while (0) 207 #define KQ_FLUX_WAKEUP(kq) do { \ 208 if (((kq)->kq_state & KQ_FLUXWAIT) == KQ_FLUXWAIT) { \ 209 (kq)->kq_state &= ~KQ_FLUXWAIT; \ 210 wakeup((kq)); \ 211 } \ 212 } while (0) 213 #define KQ_UNLOCK_FLUX(kq) do { \ 214 KQ_FLUX_WAKEUP(kq); \ 215 mtx_unlock(&(kq)->kq_lock); \ 216 } while (0) 217 #define KQ_UNLOCK(kq) do { \ 218 mtx_unlock(&(kq)->kq_lock); \ 219 } while (0) 220 #define KQ_OWNED(kq) do { \ 221 mtx_assert(&(kq)->kq_lock, MA_OWNED); \ 222 } while (0) 223 #define KQ_NOTOWNED(kq) do { \ 224 mtx_assert(&(kq)->kq_lock, MA_NOTOWNED); \ 225 } while (0) 226 #define KN_LIST_LOCK(kn) do { \ 227 if (kn->kn_knlist != NULL) \ 228 kn->kn_knlist->kl_lock(kn->kn_knlist->kl_lockarg); \ 229 } while (0) 230 #define KN_LIST_UNLOCK(kn) do { \ 231 if (kn->kn_knlist != NULL) \ 232 kn->kn_knlist->kl_unlock(kn->kn_knlist->kl_lockarg); \ 233 } while (0) 234 #define KNL_ASSERT_LOCK(knl, islocked) do { \ 235 if (islocked) \ 236 KNL_ASSERT_LOCKED(knl); \ 237 else \ 238 KNL_ASSERT_UNLOCKED(knl); \ 239 } while (0) 240 #ifdef INVARIANTS 241 #define KNL_ASSERT_LOCKED(knl) do { \ 242 knl->kl_assert_locked((knl)->kl_lockarg); \ 243 } while (0) 244 #define KNL_ASSERT_UNLOCKED(knl) do { \ 245 knl->kl_assert_unlocked((knl)->kl_lockarg); \ 246 } while (0) 247 #else /* !INVARIANTS */ 248 #define KNL_ASSERT_LOCKED(knl) do {} while(0) 249 #define KNL_ASSERT_UNLOCKED(knl) do {} while (0) 250 #endif /* INVARIANTS */ 251 252 #define KN_HASHSIZE 64 /* XXX should be tunable */ 253 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 254 255 static int 256 filt_nullattach(struct knote *kn) 257 { 258 259 return (ENXIO); 260 }; 261 262 struct filterops null_filtops = { 263 .f_isfd = 0, 264 .f_attach = filt_nullattach, 265 }; 266 267 /* XXX - make SYSINIT to add these, and move into respective modules. */ 268 extern struct filterops sig_filtops; 269 extern struct filterops fs_filtops; 270 271 /* 272 * Table for for all system-defined filters. 273 */ 274 static struct mtx filterops_lock; 275 MTX_SYSINIT(kqueue_filterops, &filterops_lock, "protect sysfilt_ops", 276 MTX_DEF); 277 static struct { 278 struct filterops *for_fop; 279 int for_refcnt; 280 } sysfilt_ops[EVFILT_SYSCOUNT] = { 281 { &file_filtops }, /* EVFILT_READ */ 282 { &file_filtops }, /* EVFILT_WRITE */ 283 { &null_filtops }, /* EVFILT_AIO */ 284 { &file_filtops }, /* EVFILT_VNODE */ 285 { &proc_filtops }, /* EVFILT_PROC */ 286 { &sig_filtops }, /* EVFILT_SIGNAL */ 287 { &timer_filtops }, /* EVFILT_TIMER */ 288 { &null_filtops }, /* former EVFILT_NETDEV */ 289 { &fs_filtops }, /* EVFILT_FS */ 290 { &null_filtops }, /* EVFILT_LIO */ 291 { &user_filtops }, /* EVFILT_USER */ 292 }; 293 294 /* 295 * Simple redirection for all cdevsw style objects to call their fo_kqfilter 296 * method. 297 */ 298 static int 299 filt_fileattach(struct knote *kn) 300 { 301 302 return (fo_kqfilter(kn->kn_fp, kn)); 303 } 304 305 /*ARGSUSED*/ 306 static int 307 kqueue_kqfilter(struct file *fp, struct knote *kn) 308 { 309 struct kqueue *kq = kn->kn_fp->f_data; 310 311 if (kn->kn_filter != EVFILT_READ) 312 return (EINVAL); 313 314 kn->kn_status |= KN_KQUEUE; 315 kn->kn_fop = &kqread_filtops; 316 knlist_add(&kq->kq_sel.si_note, kn, 0); 317 318 return (0); 319 } 320 321 static void 322 filt_kqdetach(struct knote *kn) 323 { 324 struct kqueue *kq = kn->kn_fp->f_data; 325 326 knlist_remove(&kq->kq_sel.si_note, kn, 0); 327 } 328 329 /*ARGSUSED*/ 330 static int 331 filt_kqueue(struct knote *kn, long hint) 332 { 333 struct kqueue *kq = kn->kn_fp->f_data; 334 335 kn->kn_data = kq->kq_count; 336 return (kn->kn_data > 0); 337 } 338 339 /* XXX - move to kern_proc.c? */ 340 static int 341 filt_procattach(struct knote *kn) 342 { 343 struct proc *p; 344 int immediate; 345 int error; 346 347 immediate = 0; 348 p = pfind(kn->kn_id); 349 if (p == NULL && (kn->kn_sfflags & NOTE_EXIT)) { 350 p = zpfind(kn->kn_id); 351 immediate = 1; 352 } else if (p != NULL && (p->p_flag & P_WEXIT)) { 353 immediate = 1; 354 } 355 356 if (p == NULL) 357 return (ESRCH); 358 if ((error = p_cansee(curthread, p))) { 359 PROC_UNLOCK(p); 360 return (error); 361 } 362 363 kn->kn_ptr.p_proc = p; 364 kn->kn_flags |= EV_CLEAR; /* automatically set */ 365 366 /* 367 * internal flag indicating registration done by kernel 368 */ 369 if (kn->kn_flags & EV_FLAG1) { 370 kn->kn_data = kn->kn_sdata; /* ppid */ 371 kn->kn_fflags = NOTE_CHILD; 372 kn->kn_flags &= ~EV_FLAG1; 373 } 374 375 if (immediate == 0) 376 knlist_add(&p->p_klist, kn, 1); 377 378 /* 379 * Immediately activate any exit notes if the target process is a 380 * zombie. This is necessary to handle the case where the target 381 * process, e.g. a child, dies before the kevent is registered. 382 */ 383 if (immediate && filt_proc(kn, NOTE_EXIT)) 384 KNOTE_ACTIVATE(kn, 0); 385 386 PROC_UNLOCK(p); 387 388 return (0); 389 } 390 391 /* 392 * The knote may be attached to a different process, which may exit, 393 * leaving nothing for the knote to be attached to. So when the process 394 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 395 * it will be deleted when read out. However, as part of the knote deletion, 396 * this routine is called, so a check is needed to avoid actually performing 397 * a detach, because the original process does not exist any more. 398 */ 399 /* XXX - move to kern_proc.c? */ 400 static void 401 filt_procdetach(struct knote *kn) 402 { 403 struct proc *p; 404 405 p = kn->kn_ptr.p_proc; 406 knlist_remove(&p->p_klist, kn, 0); 407 kn->kn_ptr.p_proc = NULL; 408 } 409 410 /* XXX - move to kern_proc.c? */ 411 static int 412 filt_proc(struct knote *kn, long hint) 413 { 414 struct proc *p = kn->kn_ptr.p_proc; 415 u_int event; 416 417 /* 418 * mask off extra data 419 */ 420 event = (u_int)hint & NOTE_PCTRLMASK; 421 422 /* 423 * if the user is interested in this event, record it. 424 */ 425 if (kn->kn_sfflags & event) 426 kn->kn_fflags |= event; 427 428 /* 429 * process is gone, so flag the event as finished. 430 */ 431 if (event == NOTE_EXIT) { 432 if (!(kn->kn_status & KN_DETACHED)) 433 knlist_remove_inevent(&p->p_klist, kn); 434 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 435 kn->kn_ptr.p_proc = NULL; 436 if (kn->kn_fflags & NOTE_EXIT) 437 kn->kn_data = p->p_xstat; 438 if (kn->kn_fflags == 0) 439 kn->kn_flags |= EV_DROP; 440 return (1); 441 } 442 443 return (kn->kn_fflags != 0); 444 } 445 446 /* 447 * Called when the process forked. It mostly does the same as the 448 * knote(), activating all knotes registered to be activated when the 449 * process forked. Additionally, for each knote attached to the 450 * parent, check whether user wants to track the new process. If so 451 * attach a new knote to it, and immediately report an event with the 452 * child's pid. 453 */ 454 void 455 knote_fork(struct knlist *list, int pid) 456 { 457 struct kqueue *kq; 458 struct knote *kn; 459 struct kevent kev; 460 int error; 461 462 if (list == NULL) 463 return; 464 list->kl_lock(list->kl_lockarg); 465 466 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { 467 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) 468 continue; 469 kq = kn->kn_kq; 470 KQ_LOCK(kq); 471 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 472 KQ_UNLOCK(kq); 473 continue; 474 } 475 476 /* 477 * The same as knote(), activate the event. 478 */ 479 if ((kn->kn_sfflags & NOTE_TRACK) == 0) { 480 kn->kn_status |= KN_HASKQLOCK; 481 if (kn->kn_fop->f_event(kn, NOTE_FORK)) 482 KNOTE_ACTIVATE(kn, 1); 483 kn->kn_status &= ~KN_HASKQLOCK; 484 KQ_UNLOCK(kq); 485 continue; 486 } 487 488 /* 489 * The NOTE_TRACK case. In addition to the activation 490 * of the event, we need to register new event to 491 * track the child. Drop the locks in preparation for 492 * the call to kqueue_register(). 493 */ 494 kn->kn_status |= KN_INFLUX; 495 KQ_UNLOCK(kq); 496 list->kl_unlock(list->kl_lockarg); 497 498 /* 499 * Activate existing knote and register a knote with 500 * new process. 501 */ 502 kev.ident = pid; 503 kev.filter = kn->kn_filter; 504 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 505 kev.fflags = kn->kn_sfflags; 506 kev.data = kn->kn_id; /* parent */ 507 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 508 error = kqueue_register(kq, &kev, NULL, 0); 509 if (error) 510 kn->kn_fflags |= NOTE_TRACKERR; 511 if (kn->kn_fop->f_event(kn, NOTE_FORK)) 512 KNOTE_ACTIVATE(kn, 0); 513 KQ_LOCK(kq); 514 kn->kn_status &= ~KN_INFLUX; 515 KQ_UNLOCK_FLUX(kq); 516 list->kl_lock(list->kl_lockarg); 517 } 518 list->kl_unlock(list->kl_lockarg); 519 } 520 521 /* 522 * XXX: EVFILT_TIMER should perhaps live in kern_time.c beside the 523 * interval timer support code. 524 */ 525 static __inline sbintime_t 526 timer2sbintime(intptr_t data) 527 { 528 529 return (SBT_1MS * data); 530 } 531 532 static void 533 filt_timerexpire(void *knx) 534 { 535 struct callout *calloutp; 536 struct knote *kn; 537 538 kn = knx; 539 kn->kn_data++; 540 KNOTE_ACTIVATE(kn, 0); /* XXX - handle locking */ 541 542 if ((kn->kn_flags & EV_ONESHOT) != EV_ONESHOT) { 543 calloutp = (struct callout *)kn->kn_hook; 544 callout_reset_sbt_on(calloutp, 545 timer2sbintime(kn->kn_sdata), 0 /* 1ms? */, 546 filt_timerexpire, kn, PCPU_GET(cpuid), 0); 547 } 548 } 549 550 /* 551 * data contains amount of time to sleep, in milliseconds 552 */ 553 static int 554 filt_timerattach(struct knote *kn) 555 { 556 struct callout *calloutp; 557 sbintime_t to; 558 unsigned int ncallouts; 559 560 if ((intptr_t)kn->kn_sdata < 0) 561 return (EINVAL); 562 if ((intptr_t)kn->kn_sdata == 0 && (kn->kn_flags & EV_ONESHOT) == 0) 563 kn->kn_sdata = 1; 564 to = timer2sbintime(kn->kn_sdata); 565 if (to < 0) 566 return (EINVAL); 567 568 ncallouts = atomic_load_explicit(&kq_ncallouts, memory_order_relaxed); 569 do { 570 if (ncallouts >= kq_calloutmax) 571 return (ENOMEM); 572 } while (!atomic_compare_exchange_weak_explicit(&kq_ncallouts, 573 &ncallouts, ncallouts + 1, memory_order_relaxed, 574 memory_order_relaxed)); 575 576 kn->kn_flags |= EV_CLEAR; /* automatically set */ 577 kn->kn_status &= ~KN_DETACHED; /* knlist_add clears it */ 578 calloutp = malloc(sizeof(*calloutp), M_KQUEUE, M_WAITOK); 579 callout_init(calloutp, CALLOUT_MPSAFE); 580 kn->kn_hook = calloutp; 581 callout_reset_sbt_on(calloutp, to, 0 /* 1ms? */, 582 filt_timerexpire, kn, PCPU_GET(cpuid), 0); 583 584 return (0); 585 } 586 587 static void 588 filt_timerdetach(struct knote *kn) 589 { 590 struct callout *calloutp; 591 unsigned int old; 592 593 calloutp = (struct callout *)kn->kn_hook; 594 callout_drain(calloutp); 595 free(calloutp, M_KQUEUE); 596 old = atomic_fetch_sub_explicit(&kq_ncallouts, 1, memory_order_relaxed); 597 KASSERT(old > 0, ("Number of callouts cannot become negative")); 598 kn->kn_status |= KN_DETACHED; /* knlist_remove sets it */ 599 } 600 601 static int 602 filt_timer(struct knote *kn, long hint) 603 { 604 605 return (kn->kn_data != 0); 606 } 607 608 static int 609 filt_userattach(struct knote *kn) 610 { 611 612 /* 613 * EVFILT_USER knotes are not attached to anything in the kernel. 614 */ 615 kn->kn_hook = NULL; 616 if (kn->kn_fflags & NOTE_TRIGGER) 617 kn->kn_hookid = 1; 618 else 619 kn->kn_hookid = 0; 620 return (0); 621 } 622 623 static void 624 filt_userdetach(__unused struct knote *kn) 625 { 626 627 /* 628 * EVFILT_USER knotes are not attached to anything in the kernel. 629 */ 630 } 631 632 static int 633 filt_user(struct knote *kn, __unused long hint) 634 { 635 636 return (kn->kn_hookid); 637 } 638 639 static void 640 filt_usertouch(struct knote *kn, struct kevent *kev, u_long type) 641 { 642 u_int ffctrl; 643 644 switch (type) { 645 case EVENT_REGISTER: 646 if (kev->fflags & NOTE_TRIGGER) 647 kn->kn_hookid = 1; 648 649 ffctrl = kev->fflags & NOTE_FFCTRLMASK; 650 kev->fflags &= NOTE_FFLAGSMASK; 651 switch (ffctrl) { 652 case NOTE_FFNOP: 653 break; 654 655 case NOTE_FFAND: 656 kn->kn_sfflags &= kev->fflags; 657 break; 658 659 case NOTE_FFOR: 660 kn->kn_sfflags |= kev->fflags; 661 break; 662 663 case NOTE_FFCOPY: 664 kn->kn_sfflags = kev->fflags; 665 break; 666 667 default: 668 /* XXX Return error? */ 669 break; 670 } 671 kn->kn_sdata = kev->data; 672 if (kev->flags & EV_CLEAR) { 673 kn->kn_hookid = 0; 674 kn->kn_data = 0; 675 kn->kn_fflags = 0; 676 } 677 break; 678 679 case EVENT_PROCESS: 680 *kev = kn->kn_kevent; 681 kev->fflags = kn->kn_sfflags; 682 kev->data = kn->kn_sdata; 683 if (kn->kn_flags & EV_CLEAR) { 684 kn->kn_hookid = 0; 685 kn->kn_data = 0; 686 kn->kn_fflags = 0; 687 } 688 break; 689 690 default: 691 panic("filt_usertouch() - invalid type (%ld)", type); 692 break; 693 } 694 } 695 696 int 697 sys_kqueue(struct thread *td, struct kqueue_args *uap) 698 { 699 struct filedesc *fdp; 700 struct kqueue *kq; 701 struct file *fp; 702 int fd, error; 703 704 fdp = td->td_proc->p_fd; 705 error = falloc(td, &fp, &fd, 0); 706 if (error) 707 goto done2; 708 709 /* An extra reference on `fp' has been held for us by falloc(). */ 710 kq = malloc(sizeof *kq, M_KQUEUE, M_WAITOK | M_ZERO); 711 mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF|MTX_DUPOK); 712 TAILQ_INIT(&kq->kq_head); 713 kq->kq_fdp = fdp; 714 knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock); 715 TASK_INIT(&kq->kq_task, 0, kqueue_task, kq); 716 717 FILEDESC_XLOCK(fdp); 718 TAILQ_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list); 719 FILEDESC_XUNLOCK(fdp); 720 721 finit(fp, FREAD | FWRITE, DTYPE_KQUEUE, kq, &kqueueops); 722 fdrop(fp, td); 723 724 td->td_retval[0] = fd; 725 done2: 726 return (error); 727 } 728 729 #ifndef _SYS_SYSPROTO_H_ 730 struct kevent_args { 731 int fd; 732 const struct kevent *changelist; 733 int nchanges; 734 struct kevent *eventlist; 735 int nevents; 736 const struct timespec *timeout; 737 }; 738 #endif 739 int 740 sys_kevent(struct thread *td, struct kevent_args *uap) 741 { 742 struct timespec ts, *tsp; 743 struct kevent_copyops k_ops = { uap, 744 kevent_copyout, 745 kevent_copyin}; 746 int error; 747 #ifdef KTRACE 748 struct uio ktruio; 749 struct iovec ktriov; 750 struct uio *ktruioin = NULL; 751 struct uio *ktruioout = NULL; 752 #endif 753 754 if (uap->timeout != NULL) { 755 error = copyin(uap->timeout, &ts, sizeof(ts)); 756 if (error) 757 return (error); 758 tsp = &ts; 759 } else 760 tsp = NULL; 761 762 #ifdef KTRACE 763 if (KTRPOINT(td, KTR_GENIO)) { 764 ktriov.iov_base = uap->changelist; 765 ktriov.iov_len = uap->nchanges * sizeof(struct kevent); 766 ktruio = (struct uio){ .uio_iov = &ktriov, .uio_iovcnt = 1, 767 .uio_segflg = UIO_USERSPACE, .uio_rw = UIO_READ, 768 .uio_td = td }; 769 ktruioin = cloneuio(&ktruio); 770 ktriov.iov_base = uap->eventlist; 771 ktriov.iov_len = uap->nevents * sizeof(struct kevent); 772 ktruioout = cloneuio(&ktruio); 773 } 774 #endif 775 776 error = kern_kevent(td, uap->fd, uap->nchanges, uap->nevents, 777 &k_ops, tsp); 778 779 #ifdef KTRACE 780 if (ktruioin != NULL) { 781 ktruioin->uio_resid = uap->nchanges * sizeof(struct kevent); 782 ktrgenio(uap->fd, UIO_WRITE, ktruioin, 0); 783 ktruioout->uio_resid = td->td_retval[0] * sizeof(struct kevent); 784 ktrgenio(uap->fd, UIO_READ, ktruioout, error); 785 } 786 #endif 787 788 return (error); 789 } 790 791 /* 792 * Copy 'count' items into the destination list pointed to by uap->eventlist. 793 */ 794 static int 795 kevent_copyout(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 = copyout(kevp, uap->eventlist, count * sizeof *kevp); 804 if (error == 0) 805 uap->eventlist += count; 806 return (error); 807 } 808 809 /* 810 * Copy 'count' items from the list pointed to by uap->changelist. 811 */ 812 static int 813 kevent_copyin(void *arg, struct kevent *kevp, int count) 814 { 815 struct kevent_args *uap; 816 int error; 817 818 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 819 uap = (struct kevent_args *)arg; 820 821 error = copyin(uap->changelist, kevp, count * sizeof *kevp); 822 if (error == 0) 823 uap->changelist += count; 824 return (error); 825 } 826 827 int 828 kern_kevent(struct thread *td, int fd, int nchanges, int nevents, 829 struct kevent_copyops *k_ops, const struct timespec *timeout) 830 { 831 struct kevent keva[KQ_NEVENTS]; 832 struct kevent *kevp, *changes; 833 struct kqueue *kq; 834 struct file *fp; 835 cap_rights_t rights; 836 int i, n, nerrors, error; 837 838 error = fget(td, fd, cap_rights_init(&rights, CAP_POST_EVENT), &fp); 839 if (error != 0) 840 return (error); 841 if ((error = kqueue_acquire(fp, &kq)) != 0) 842 goto done_norel; 843 844 nerrors = 0; 845 846 while (nchanges > 0) { 847 n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges; 848 error = k_ops->k_copyin(k_ops->arg, keva, n); 849 if (error) 850 goto done; 851 changes = keva; 852 for (i = 0; i < n; i++) { 853 kevp = &changes[i]; 854 if (!kevp->filter) 855 continue; 856 kevp->flags &= ~EV_SYSFLAGS; 857 error = kqueue_register(kq, kevp, td, 1); 858 if (error || (kevp->flags & EV_RECEIPT)) { 859 if (nevents != 0) { 860 kevp->flags = EV_ERROR; 861 kevp->data = error; 862 (void) k_ops->k_copyout(k_ops->arg, 863 kevp, 1); 864 nevents--; 865 nerrors++; 866 } else { 867 goto done; 868 } 869 } 870 } 871 nchanges -= n; 872 } 873 if (nerrors) { 874 td->td_retval[0] = nerrors; 875 error = 0; 876 goto done; 877 } 878 879 error = kqueue_scan(kq, nevents, k_ops, timeout, keva, td); 880 done: 881 kqueue_release(kq, 0); 882 done_norel: 883 fdrop(fp, td); 884 return (error); 885 } 886 887 int 888 kqueue_add_filteropts(int filt, struct filterops *filtops) 889 { 890 int error; 891 892 error = 0; 893 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) { 894 printf( 895 "trying to add a filterop that is out of range: %d is beyond %d\n", 896 ~filt, EVFILT_SYSCOUNT); 897 return EINVAL; 898 } 899 mtx_lock(&filterops_lock); 900 if (sysfilt_ops[~filt].for_fop != &null_filtops && 901 sysfilt_ops[~filt].for_fop != NULL) 902 error = EEXIST; 903 else { 904 sysfilt_ops[~filt].for_fop = filtops; 905 sysfilt_ops[~filt].for_refcnt = 0; 906 } 907 mtx_unlock(&filterops_lock); 908 909 return (error); 910 } 911 912 int 913 kqueue_del_filteropts(int filt) 914 { 915 int error; 916 917 error = 0; 918 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 919 return EINVAL; 920 921 mtx_lock(&filterops_lock); 922 if (sysfilt_ops[~filt].for_fop == &null_filtops || 923 sysfilt_ops[~filt].for_fop == NULL) 924 error = EINVAL; 925 else if (sysfilt_ops[~filt].for_refcnt != 0) 926 error = EBUSY; 927 else { 928 sysfilt_ops[~filt].for_fop = &null_filtops; 929 sysfilt_ops[~filt].for_refcnt = 0; 930 } 931 mtx_unlock(&filterops_lock); 932 933 return error; 934 } 935 936 static struct filterops * 937 kqueue_fo_find(int filt) 938 { 939 940 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 941 return NULL; 942 943 mtx_lock(&filterops_lock); 944 sysfilt_ops[~filt].for_refcnt++; 945 if (sysfilt_ops[~filt].for_fop == NULL) 946 sysfilt_ops[~filt].for_fop = &null_filtops; 947 mtx_unlock(&filterops_lock); 948 949 return sysfilt_ops[~filt].for_fop; 950 } 951 952 static void 953 kqueue_fo_release(int filt) 954 { 955 956 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 957 return; 958 959 mtx_lock(&filterops_lock); 960 KASSERT(sysfilt_ops[~filt].for_refcnt > 0, 961 ("filter object refcount not valid on release")); 962 sysfilt_ops[~filt].for_refcnt--; 963 mtx_unlock(&filterops_lock); 964 } 965 966 /* 967 * A ref to kq (obtained via kqueue_acquire) must be held. waitok will 968 * influence if memory allocation should wait. Make sure it is 0 if you 969 * hold any mutexes. 970 */ 971 static int 972 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, int waitok) 973 { 974 struct filterops *fops; 975 struct file *fp; 976 struct knote *kn, *tkn; 977 cap_rights_t rights; 978 int error, filt, event; 979 int haskqglobal, filedesc_unlock; 980 981 fp = NULL; 982 kn = NULL; 983 error = 0; 984 haskqglobal = 0; 985 filedesc_unlock = 0; 986 987 filt = kev->filter; 988 fops = kqueue_fo_find(filt); 989 if (fops == NULL) 990 return EINVAL; 991 992 tkn = knote_alloc(waitok); /* prevent waiting with locks */ 993 994 findkn: 995 if (fops->f_isfd) { 996 KASSERT(td != NULL, ("td is NULL")); 997 error = fget(td, kev->ident, 998 cap_rights_init(&rights, CAP_POLL_EVENT), &fp); 999 if (error) 1000 goto done; 1001 1002 if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops, 1003 kev->ident, 0) != 0) { 1004 /* try again */ 1005 fdrop(fp, td); 1006 fp = NULL; 1007 error = kqueue_expand(kq, fops, kev->ident, waitok); 1008 if (error) 1009 goto done; 1010 goto findkn; 1011 } 1012 1013 if (fp->f_type == DTYPE_KQUEUE) { 1014 /* 1015 * if we add some inteligence about what we are doing, 1016 * we should be able to support events on ourselves. 1017 * We need to know when we are doing this to prevent 1018 * getting both the knlist lock and the kq lock since 1019 * they are the same thing. 1020 */ 1021 if (fp->f_data == kq) { 1022 error = EINVAL; 1023 goto done; 1024 } 1025 1026 /* 1027 * Pre-lock the filedesc before the global 1028 * lock mutex, see the comment in 1029 * kqueue_close(). 1030 */ 1031 FILEDESC_XLOCK(td->td_proc->p_fd); 1032 filedesc_unlock = 1; 1033 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1034 } 1035 1036 KQ_LOCK(kq); 1037 if (kev->ident < kq->kq_knlistsize) { 1038 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link) 1039 if (kev->filter == kn->kn_filter) 1040 break; 1041 } 1042 } else { 1043 if ((kev->flags & EV_ADD) == EV_ADD) 1044 kqueue_expand(kq, fops, kev->ident, waitok); 1045 1046 KQ_LOCK(kq); 1047 if (kq->kq_knhashmask != 0) { 1048 struct klist *list; 1049 1050 list = &kq->kq_knhash[ 1051 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)]; 1052 SLIST_FOREACH(kn, list, kn_link) 1053 if (kev->ident == kn->kn_id && 1054 kev->filter == kn->kn_filter) 1055 break; 1056 } 1057 } 1058 1059 /* knote is in the process of changing, wait for it to stablize. */ 1060 if (kn != NULL && (kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1061 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1062 if (filedesc_unlock) { 1063 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1064 filedesc_unlock = 0; 1065 } 1066 kq->kq_state |= KQ_FLUXWAIT; 1067 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0); 1068 if (fp != NULL) { 1069 fdrop(fp, td); 1070 fp = NULL; 1071 } 1072 goto findkn; 1073 } 1074 1075 /* 1076 * kn now contains the matching knote, or NULL if no match 1077 */ 1078 if (kn == NULL) { 1079 if (kev->flags & EV_ADD) { 1080 kn = tkn; 1081 tkn = NULL; 1082 if (kn == NULL) { 1083 KQ_UNLOCK(kq); 1084 error = ENOMEM; 1085 goto done; 1086 } 1087 kn->kn_fp = fp; 1088 kn->kn_kq = kq; 1089 kn->kn_fop = fops; 1090 /* 1091 * apply reference counts to knote structure, and 1092 * do not release it at the end of this routine. 1093 */ 1094 fops = NULL; 1095 fp = NULL; 1096 1097 kn->kn_sfflags = kev->fflags; 1098 kn->kn_sdata = kev->data; 1099 kev->fflags = 0; 1100 kev->data = 0; 1101 kn->kn_kevent = *kev; 1102 kn->kn_kevent.flags &= ~(EV_ADD | EV_DELETE | 1103 EV_ENABLE | EV_DISABLE); 1104 kn->kn_status = KN_INFLUX|KN_DETACHED; 1105 1106 error = knote_attach(kn, kq); 1107 KQ_UNLOCK(kq); 1108 if (error != 0) { 1109 tkn = kn; 1110 goto done; 1111 } 1112 1113 if ((error = kn->kn_fop->f_attach(kn)) != 0) { 1114 knote_drop(kn, td); 1115 goto done; 1116 } 1117 KN_LIST_LOCK(kn); 1118 goto done_ev_add; 1119 } else { 1120 /* No matching knote and the EV_ADD flag is not set. */ 1121 KQ_UNLOCK(kq); 1122 error = ENOENT; 1123 goto done; 1124 } 1125 } 1126 1127 if (kev->flags & EV_DELETE) { 1128 kn->kn_status |= KN_INFLUX; 1129 KQ_UNLOCK(kq); 1130 if (!(kn->kn_status & KN_DETACHED)) 1131 kn->kn_fop->f_detach(kn); 1132 knote_drop(kn, td); 1133 goto done; 1134 } 1135 1136 /* 1137 * The user may change some filter values after the initial EV_ADD, 1138 * but doing so will not reset any filter which has already been 1139 * triggered. 1140 */ 1141 kn->kn_status |= KN_INFLUX; 1142 KQ_UNLOCK(kq); 1143 KN_LIST_LOCK(kn); 1144 kn->kn_kevent.udata = kev->udata; 1145 if (!fops->f_isfd && fops->f_touch != NULL) { 1146 fops->f_touch(kn, kev, EVENT_REGISTER); 1147 } else { 1148 kn->kn_sfflags = kev->fflags; 1149 kn->kn_sdata = kev->data; 1150 } 1151 1152 /* 1153 * We can get here with kn->kn_knlist == NULL. This can happen when 1154 * the initial attach event decides that the event is "completed" 1155 * already. i.e. filt_procattach is called on a zombie process. It 1156 * will call filt_proc which will remove it from the list, and NULL 1157 * kn_knlist. 1158 */ 1159 done_ev_add: 1160 event = kn->kn_fop->f_event(kn, 0); 1161 KQ_LOCK(kq); 1162 if (event) 1163 KNOTE_ACTIVATE(kn, 1); 1164 kn->kn_status &= ~KN_INFLUX; 1165 KN_LIST_UNLOCK(kn); 1166 1167 if ((kev->flags & EV_DISABLE) && 1168 ((kn->kn_status & KN_DISABLED) == 0)) { 1169 kn->kn_status |= KN_DISABLED; 1170 } 1171 1172 if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) { 1173 kn->kn_status &= ~KN_DISABLED; 1174 if ((kn->kn_status & KN_ACTIVE) && 1175 ((kn->kn_status & KN_QUEUED) == 0)) 1176 knote_enqueue(kn); 1177 } 1178 KQ_UNLOCK_FLUX(kq); 1179 1180 done: 1181 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1182 if (filedesc_unlock) 1183 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1184 if (fp != NULL) 1185 fdrop(fp, td); 1186 if (tkn != NULL) 1187 knote_free(tkn); 1188 if (fops != NULL) 1189 kqueue_fo_release(filt); 1190 return (error); 1191 } 1192 1193 static int 1194 kqueue_acquire(struct file *fp, struct kqueue **kqp) 1195 { 1196 int error; 1197 struct kqueue *kq; 1198 1199 error = 0; 1200 1201 kq = fp->f_data; 1202 if (fp->f_type != DTYPE_KQUEUE || kq == NULL) 1203 return (EBADF); 1204 *kqp = kq; 1205 KQ_LOCK(kq); 1206 if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) { 1207 KQ_UNLOCK(kq); 1208 return (EBADF); 1209 } 1210 kq->kq_refcnt++; 1211 KQ_UNLOCK(kq); 1212 1213 return error; 1214 } 1215 1216 static void 1217 kqueue_release(struct kqueue *kq, int locked) 1218 { 1219 if (locked) 1220 KQ_OWNED(kq); 1221 else 1222 KQ_LOCK(kq); 1223 kq->kq_refcnt--; 1224 if (kq->kq_refcnt == 1) 1225 wakeup(&kq->kq_refcnt); 1226 if (!locked) 1227 KQ_UNLOCK(kq); 1228 } 1229 1230 static void 1231 kqueue_schedtask(struct kqueue *kq) 1232 { 1233 1234 KQ_OWNED(kq); 1235 KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN), 1236 ("scheduling kqueue task while draining")); 1237 1238 if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) { 1239 taskqueue_enqueue(taskqueue_kqueue, &kq->kq_task); 1240 kq->kq_state |= KQ_TASKSCHED; 1241 } 1242 } 1243 1244 /* 1245 * Expand the kq to make sure we have storage for fops/ident pair. 1246 * 1247 * Return 0 on success (or no work necessary), return errno on failure. 1248 * 1249 * Not calling hashinit w/ waitok (proper malloc flag) should be safe. 1250 * If kqueue_register is called from a non-fd context, there usually/should 1251 * be no locks held. 1252 */ 1253 static int 1254 kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident, 1255 int waitok) 1256 { 1257 struct klist *list, *tmp_knhash, *to_free; 1258 u_long tmp_knhashmask; 1259 int size; 1260 int fd; 1261 int mflag = waitok ? M_WAITOK : M_NOWAIT; 1262 1263 KQ_NOTOWNED(kq); 1264 1265 to_free = NULL; 1266 if (fops->f_isfd) { 1267 fd = ident; 1268 if (kq->kq_knlistsize <= fd) { 1269 size = kq->kq_knlistsize; 1270 while (size <= fd) 1271 size += KQEXTENT; 1272 list = malloc(size * sizeof(*list), M_KQUEUE, mflag); 1273 if (list == NULL) 1274 return ENOMEM; 1275 KQ_LOCK(kq); 1276 if (kq->kq_knlistsize > fd) { 1277 to_free = list; 1278 list = NULL; 1279 } else { 1280 if (kq->kq_knlist != NULL) { 1281 bcopy(kq->kq_knlist, list, 1282 kq->kq_knlistsize * sizeof(*list)); 1283 to_free = kq->kq_knlist; 1284 kq->kq_knlist = NULL; 1285 } 1286 bzero((caddr_t)list + 1287 kq->kq_knlistsize * sizeof(*list), 1288 (size - kq->kq_knlistsize) * sizeof(*list)); 1289 kq->kq_knlistsize = size; 1290 kq->kq_knlist = list; 1291 } 1292 KQ_UNLOCK(kq); 1293 } 1294 } else { 1295 if (kq->kq_knhashmask == 0) { 1296 tmp_knhash = hashinit(KN_HASHSIZE, M_KQUEUE, 1297 &tmp_knhashmask); 1298 if (tmp_knhash == NULL) 1299 return ENOMEM; 1300 KQ_LOCK(kq); 1301 if (kq->kq_knhashmask == 0) { 1302 kq->kq_knhash = tmp_knhash; 1303 kq->kq_knhashmask = tmp_knhashmask; 1304 } else { 1305 to_free = tmp_knhash; 1306 } 1307 KQ_UNLOCK(kq); 1308 } 1309 } 1310 free(to_free, M_KQUEUE); 1311 1312 KQ_NOTOWNED(kq); 1313 return 0; 1314 } 1315 1316 static void 1317 kqueue_task(void *arg, int pending) 1318 { 1319 struct kqueue *kq; 1320 int haskqglobal; 1321 1322 haskqglobal = 0; 1323 kq = arg; 1324 1325 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1326 KQ_LOCK(kq); 1327 1328 KNOTE_LOCKED(&kq->kq_sel.si_note, 0); 1329 1330 kq->kq_state &= ~KQ_TASKSCHED; 1331 if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) { 1332 wakeup(&kq->kq_state); 1333 } 1334 KQ_UNLOCK(kq); 1335 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1336 } 1337 1338 /* 1339 * Scan, update kn_data (if not ONESHOT), and copyout triggered events. 1340 * We treat KN_MARKER knotes as if they are INFLUX. 1341 */ 1342 static int 1343 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops, 1344 const struct timespec *tsp, struct kevent *keva, struct thread *td) 1345 { 1346 struct kevent *kevp; 1347 struct knote *kn, *marker; 1348 sbintime_t asbt, rsbt; 1349 int count, error, haskqglobal, influx, nkev, touch; 1350 1351 count = maxevents; 1352 nkev = 0; 1353 error = 0; 1354 haskqglobal = 0; 1355 1356 if (maxevents == 0) 1357 goto done_nl; 1358 1359 rsbt = 0; 1360 if (tsp != NULL) { 1361 if (tsp->tv_sec < 0 || tsp->tv_nsec < 0 || 1362 tsp->tv_nsec >= 1000000000) { 1363 error = EINVAL; 1364 goto done_nl; 1365 } 1366 if (timespecisset(tsp)) { 1367 if (tsp->tv_sec <= INT32_MAX) { 1368 rsbt = tstosbt(*tsp); 1369 if (TIMESEL(&asbt, rsbt)) 1370 asbt += tc_tick_sbt; 1371 if (asbt <= INT64_MAX - rsbt) 1372 asbt += rsbt; 1373 else 1374 asbt = 0; 1375 rsbt >>= tc_precexp; 1376 } else 1377 asbt = 0; 1378 } else 1379 asbt = -1; 1380 } else 1381 asbt = 0; 1382 marker = knote_alloc(1); 1383 if (marker == NULL) { 1384 error = ENOMEM; 1385 goto done_nl; 1386 } 1387 marker->kn_status = KN_MARKER; 1388 KQ_LOCK(kq); 1389 1390 retry: 1391 kevp = keva; 1392 if (kq->kq_count == 0) { 1393 if (asbt == -1) { 1394 error = EWOULDBLOCK; 1395 } else { 1396 kq->kq_state |= KQ_SLEEP; 1397 error = msleep_sbt(kq, &kq->kq_lock, PSOCK | PCATCH, 1398 "kqread", asbt, rsbt, C_ABSOLUTE); 1399 } 1400 if (error == 0) 1401 goto retry; 1402 /* don't restart after signals... */ 1403 if (error == ERESTART) 1404 error = EINTR; 1405 else if (error == EWOULDBLOCK) 1406 error = 0; 1407 goto done; 1408 } 1409 1410 TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); 1411 influx = 0; 1412 while (count) { 1413 KQ_OWNED(kq); 1414 kn = TAILQ_FIRST(&kq->kq_head); 1415 1416 if ((kn->kn_status == KN_MARKER && kn != marker) || 1417 (kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1418 if (influx) { 1419 influx = 0; 1420 KQ_FLUX_WAKEUP(kq); 1421 } 1422 kq->kq_state |= KQ_FLUXWAIT; 1423 error = msleep(kq, &kq->kq_lock, PSOCK, 1424 "kqflxwt", 0); 1425 continue; 1426 } 1427 1428 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1429 if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) { 1430 kn->kn_status &= ~KN_QUEUED; 1431 kq->kq_count--; 1432 continue; 1433 } 1434 if (kn == marker) { 1435 KQ_FLUX_WAKEUP(kq); 1436 if (count == maxevents) 1437 goto retry; 1438 goto done; 1439 } 1440 KASSERT((kn->kn_status & KN_INFLUX) == 0, 1441 ("KN_INFLUX set when not suppose to be")); 1442 1443 if ((kn->kn_flags & EV_DROP) == EV_DROP) { 1444 kn->kn_status &= ~KN_QUEUED; 1445 kn->kn_status |= KN_INFLUX; 1446 kq->kq_count--; 1447 KQ_UNLOCK(kq); 1448 /* 1449 * We don't need to lock the list since we've marked 1450 * it _INFLUX. 1451 */ 1452 if (!(kn->kn_status & KN_DETACHED)) 1453 kn->kn_fop->f_detach(kn); 1454 knote_drop(kn, td); 1455 KQ_LOCK(kq); 1456 continue; 1457 } else if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) { 1458 kn->kn_status &= ~KN_QUEUED; 1459 kn->kn_status |= KN_INFLUX; 1460 kq->kq_count--; 1461 KQ_UNLOCK(kq); 1462 /* 1463 * We don't need to lock the list since we've marked 1464 * it _INFLUX. 1465 */ 1466 *kevp = kn->kn_kevent; 1467 if (!(kn->kn_status & KN_DETACHED)) 1468 kn->kn_fop->f_detach(kn); 1469 knote_drop(kn, td); 1470 KQ_LOCK(kq); 1471 kn = NULL; 1472 } else { 1473 kn->kn_status |= KN_INFLUX; 1474 KQ_UNLOCK(kq); 1475 if ((kn->kn_status & KN_KQUEUE) == KN_KQUEUE) 1476 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1477 KN_LIST_LOCK(kn); 1478 if (kn->kn_fop->f_event(kn, 0) == 0) { 1479 KQ_LOCK(kq); 1480 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1481 kn->kn_status &= 1482 ~(KN_QUEUED | KN_ACTIVE | KN_INFLUX); 1483 kq->kq_count--; 1484 KN_LIST_UNLOCK(kn); 1485 influx = 1; 1486 continue; 1487 } 1488 touch = (!kn->kn_fop->f_isfd && 1489 kn->kn_fop->f_touch != NULL); 1490 if (touch) 1491 kn->kn_fop->f_touch(kn, kevp, EVENT_PROCESS); 1492 else 1493 *kevp = kn->kn_kevent; 1494 KQ_LOCK(kq); 1495 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1496 if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) { 1497 /* 1498 * Manually clear knotes who weren't 1499 * 'touch'ed. 1500 */ 1501 if (touch == 0 && kn->kn_flags & EV_CLEAR) { 1502 kn->kn_data = 0; 1503 kn->kn_fflags = 0; 1504 } 1505 if (kn->kn_flags & EV_DISPATCH) 1506 kn->kn_status |= KN_DISABLED; 1507 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 1508 kq->kq_count--; 1509 } else 1510 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 1511 1512 kn->kn_status &= ~(KN_INFLUX); 1513 KN_LIST_UNLOCK(kn); 1514 influx = 1; 1515 } 1516 1517 /* we are returning a copy to the user */ 1518 kevp++; 1519 nkev++; 1520 count--; 1521 1522 if (nkev == KQ_NEVENTS) { 1523 influx = 0; 1524 KQ_UNLOCK_FLUX(kq); 1525 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1526 nkev = 0; 1527 kevp = keva; 1528 KQ_LOCK(kq); 1529 if (error) 1530 break; 1531 } 1532 } 1533 TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); 1534 done: 1535 KQ_OWNED(kq); 1536 KQ_UNLOCK_FLUX(kq); 1537 knote_free(marker); 1538 done_nl: 1539 KQ_NOTOWNED(kq); 1540 if (nkev != 0) 1541 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1542 td->td_retval[0] = maxevents - count; 1543 return (error); 1544 } 1545 1546 /* 1547 * XXX 1548 * This could be expanded to call kqueue_scan, if desired. 1549 */ 1550 /*ARGSUSED*/ 1551 static int 1552 kqueue_read(struct file *fp, struct uio *uio, struct ucred *active_cred, 1553 int flags, struct thread *td) 1554 { 1555 return (ENXIO); 1556 } 1557 1558 /*ARGSUSED*/ 1559 static int 1560 kqueue_write(struct file *fp, struct uio *uio, struct ucred *active_cred, 1561 int flags, struct thread *td) 1562 { 1563 return (ENXIO); 1564 } 1565 1566 /*ARGSUSED*/ 1567 static int 1568 kqueue_truncate(struct file *fp, off_t length, struct ucred *active_cred, 1569 struct thread *td) 1570 { 1571 1572 return (EINVAL); 1573 } 1574 1575 /*ARGSUSED*/ 1576 static int 1577 kqueue_ioctl(struct file *fp, u_long cmd, void *data, 1578 struct ucred *active_cred, struct thread *td) 1579 { 1580 /* 1581 * Enabling sigio causes two major problems: 1582 * 1) infinite recursion: 1583 * Synopsys: kevent is being used to track signals and have FIOASYNC 1584 * set. On receipt of a signal this will cause a kqueue to recurse 1585 * into itself over and over. Sending the sigio causes the kqueue 1586 * to become ready, which in turn posts sigio again, forever. 1587 * Solution: this can be solved by setting a flag in the kqueue that 1588 * we have a SIGIO in progress. 1589 * 2) locking problems: 1590 * Synopsys: Kqueue is a leaf subsystem, but adding signalling puts 1591 * us above the proc and pgrp locks. 1592 * Solution: Post a signal using an async mechanism, being sure to 1593 * record a generation count in the delivery so that we do not deliver 1594 * a signal to the wrong process. 1595 * 1596 * Note, these two mechanisms are somewhat mutually exclusive! 1597 */ 1598 #if 0 1599 struct kqueue *kq; 1600 1601 kq = fp->f_data; 1602 switch (cmd) { 1603 case FIOASYNC: 1604 if (*(int *)data) { 1605 kq->kq_state |= KQ_ASYNC; 1606 } else { 1607 kq->kq_state &= ~KQ_ASYNC; 1608 } 1609 return (0); 1610 1611 case FIOSETOWN: 1612 return (fsetown(*(int *)data, &kq->kq_sigio)); 1613 1614 case FIOGETOWN: 1615 *(int *)data = fgetown(&kq->kq_sigio); 1616 return (0); 1617 } 1618 #endif 1619 1620 return (ENOTTY); 1621 } 1622 1623 /*ARGSUSED*/ 1624 static int 1625 kqueue_poll(struct file *fp, int events, struct ucred *active_cred, 1626 struct thread *td) 1627 { 1628 struct kqueue *kq; 1629 int revents = 0; 1630 int error; 1631 1632 if ((error = kqueue_acquire(fp, &kq))) 1633 return POLLERR; 1634 1635 KQ_LOCK(kq); 1636 if (events & (POLLIN | POLLRDNORM)) { 1637 if (kq->kq_count) { 1638 revents |= events & (POLLIN | POLLRDNORM); 1639 } else { 1640 selrecord(td, &kq->kq_sel); 1641 if (SEL_WAITING(&kq->kq_sel)) 1642 kq->kq_state |= KQ_SEL; 1643 } 1644 } 1645 kqueue_release(kq, 1); 1646 KQ_UNLOCK(kq); 1647 return (revents); 1648 } 1649 1650 /*ARGSUSED*/ 1651 static int 1652 kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred, 1653 struct thread *td) 1654 { 1655 1656 bzero((void *)st, sizeof *st); 1657 /* 1658 * We no longer return kq_count because the unlocked value is useless. 1659 * If you spent all this time getting the count, why not spend your 1660 * syscall better by calling kevent? 1661 * 1662 * XXX - This is needed for libc_r. 1663 */ 1664 st->st_mode = S_IFIFO; 1665 return (0); 1666 } 1667 1668 /*ARGSUSED*/ 1669 static int 1670 kqueue_close(struct file *fp, struct thread *td) 1671 { 1672 struct kqueue *kq = fp->f_data; 1673 struct filedesc *fdp; 1674 struct knote *kn; 1675 int i; 1676 int error; 1677 int filedesc_unlock; 1678 1679 if ((error = kqueue_acquire(fp, &kq))) 1680 return error; 1681 1682 filedesc_unlock = 0; 1683 KQ_LOCK(kq); 1684 1685 KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING, 1686 ("kqueue already closing")); 1687 kq->kq_state |= KQ_CLOSING; 1688 if (kq->kq_refcnt > 1) 1689 msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0); 1690 1691 KASSERT(kq->kq_refcnt == 1, ("other refs are out there!")); 1692 fdp = kq->kq_fdp; 1693 1694 KASSERT(knlist_empty(&kq->kq_sel.si_note), 1695 ("kqueue's knlist not empty")); 1696 1697 for (i = 0; i < kq->kq_knlistsize; i++) { 1698 while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) { 1699 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1700 kq->kq_state |= KQ_FLUXWAIT; 1701 msleep(kq, &kq->kq_lock, PSOCK, "kqclo1", 0); 1702 continue; 1703 } 1704 kn->kn_status |= KN_INFLUX; 1705 KQ_UNLOCK(kq); 1706 if (!(kn->kn_status & KN_DETACHED)) 1707 kn->kn_fop->f_detach(kn); 1708 knote_drop(kn, td); 1709 KQ_LOCK(kq); 1710 } 1711 } 1712 if (kq->kq_knhashmask != 0) { 1713 for (i = 0; i <= kq->kq_knhashmask; i++) { 1714 while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) { 1715 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1716 kq->kq_state |= KQ_FLUXWAIT; 1717 msleep(kq, &kq->kq_lock, PSOCK, 1718 "kqclo2", 0); 1719 continue; 1720 } 1721 kn->kn_status |= KN_INFLUX; 1722 KQ_UNLOCK(kq); 1723 if (!(kn->kn_status & KN_DETACHED)) 1724 kn->kn_fop->f_detach(kn); 1725 knote_drop(kn, td); 1726 KQ_LOCK(kq); 1727 } 1728 } 1729 } 1730 1731 if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) { 1732 kq->kq_state |= KQ_TASKDRAIN; 1733 msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0); 1734 } 1735 1736 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 1737 selwakeuppri(&kq->kq_sel, PSOCK); 1738 if (!SEL_WAITING(&kq->kq_sel)) 1739 kq->kq_state &= ~KQ_SEL; 1740 } 1741 1742 KQ_UNLOCK(kq); 1743 1744 /* 1745 * We could be called due to the knote_drop() doing fdrop(), 1746 * called from kqueue_register(). In this case the global 1747 * lock is owned, and filedesc sx is locked before, to not 1748 * take the sleepable lock after non-sleepable. 1749 */ 1750 if (!sx_xlocked(FILEDESC_LOCK(fdp))) { 1751 FILEDESC_XLOCK(fdp); 1752 filedesc_unlock = 1; 1753 } else 1754 filedesc_unlock = 0; 1755 TAILQ_REMOVE(&fdp->fd_kqlist, kq, kq_list); 1756 if (filedesc_unlock) 1757 FILEDESC_XUNLOCK(fdp); 1758 1759 seldrain(&kq->kq_sel); 1760 knlist_destroy(&kq->kq_sel.si_note); 1761 mtx_destroy(&kq->kq_lock); 1762 kq->kq_fdp = NULL; 1763 1764 if (kq->kq_knhash != NULL) 1765 free(kq->kq_knhash, M_KQUEUE); 1766 if (kq->kq_knlist != NULL) 1767 free(kq->kq_knlist, M_KQUEUE); 1768 1769 funsetown(&kq->kq_sigio); 1770 free(kq, M_KQUEUE); 1771 fp->f_data = NULL; 1772 1773 return (0); 1774 } 1775 1776 static void 1777 kqueue_wakeup(struct kqueue *kq) 1778 { 1779 KQ_OWNED(kq); 1780 1781 if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) { 1782 kq->kq_state &= ~KQ_SLEEP; 1783 wakeup(kq); 1784 } 1785 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 1786 selwakeuppri(&kq->kq_sel, PSOCK); 1787 if (!SEL_WAITING(&kq->kq_sel)) 1788 kq->kq_state &= ~KQ_SEL; 1789 } 1790 if (!knlist_empty(&kq->kq_sel.si_note)) 1791 kqueue_schedtask(kq); 1792 if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) { 1793 pgsigio(&kq->kq_sigio, SIGIO, 0); 1794 } 1795 } 1796 1797 /* 1798 * Walk down a list of knotes, activating them if their event has triggered. 1799 * 1800 * There is a possibility to optimize in the case of one kq watching another. 1801 * Instead of scheduling a task to wake it up, you could pass enough state 1802 * down the chain to make up the parent kqueue. Make this code functional 1803 * first. 1804 */ 1805 void 1806 knote(struct knlist *list, long hint, int lockflags) 1807 { 1808 struct kqueue *kq; 1809 struct knote *kn; 1810 int error; 1811 1812 if (list == NULL) 1813 return; 1814 1815 KNL_ASSERT_LOCK(list, lockflags & KNF_LISTLOCKED); 1816 1817 if ((lockflags & KNF_LISTLOCKED) == 0) 1818 list->kl_lock(list->kl_lockarg); 1819 1820 /* 1821 * If we unlock the list lock (and set KN_INFLUX), we can eliminate 1822 * the kqueue scheduling, but this will introduce four 1823 * lock/unlock's for each knote to test. If we do, continue to use 1824 * SLIST_FOREACH, SLIST_FOREACH_SAFE is not safe in our case, it is 1825 * only safe if you want to remove the current item, which we are 1826 * not doing. 1827 */ 1828 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { 1829 kq = kn->kn_kq; 1830 if ((kn->kn_status & KN_INFLUX) != KN_INFLUX) { 1831 KQ_LOCK(kq); 1832 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1833 KQ_UNLOCK(kq); 1834 } else if ((lockflags & KNF_NOKQLOCK) != 0) { 1835 kn->kn_status |= KN_INFLUX; 1836 KQ_UNLOCK(kq); 1837 error = kn->kn_fop->f_event(kn, hint); 1838 KQ_LOCK(kq); 1839 kn->kn_status &= ~KN_INFLUX; 1840 if (error) 1841 KNOTE_ACTIVATE(kn, 1); 1842 KQ_UNLOCK_FLUX(kq); 1843 } else { 1844 kn->kn_status |= KN_HASKQLOCK; 1845 if (kn->kn_fop->f_event(kn, hint)) 1846 KNOTE_ACTIVATE(kn, 1); 1847 kn->kn_status &= ~KN_HASKQLOCK; 1848 KQ_UNLOCK(kq); 1849 } 1850 } 1851 kq = NULL; 1852 } 1853 if ((lockflags & KNF_LISTLOCKED) == 0) 1854 list->kl_unlock(list->kl_lockarg); 1855 } 1856 1857 /* 1858 * add a knote to a knlist 1859 */ 1860 void 1861 knlist_add(struct knlist *knl, struct knote *kn, int islocked) 1862 { 1863 KNL_ASSERT_LOCK(knl, islocked); 1864 KQ_NOTOWNED(kn->kn_kq); 1865 KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) == 1866 (KN_INFLUX|KN_DETACHED), ("knote not KN_INFLUX and KN_DETACHED")); 1867 if (!islocked) 1868 knl->kl_lock(knl->kl_lockarg); 1869 SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext); 1870 if (!islocked) 1871 knl->kl_unlock(knl->kl_lockarg); 1872 KQ_LOCK(kn->kn_kq); 1873 kn->kn_knlist = knl; 1874 kn->kn_status &= ~KN_DETACHED; 1875 KQ_UNLOCK(kn->kn_kq); 1876 } 1877 1878 static void 1879 knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked, int kqislocked) 1880 { 1881 KASSERT(!(!!kqislocked && !knlislocked), ("kq locked w/o knl locked")); 1882 KNL_ASSERT_LOCK(knl, knlislocked); 1883 mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED); 1884 if (!kqislocked) 1885 KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) == KN_INFLUX, 1886 ("knlist_remove called w/o knote being KN_INFLUX or already removed")); 1887 if (!knlislocked) 1888 knl->kl_lock(knl->kl_lockarg); 1889 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext); 1890 kn->kn_knlist = NULL; 1891 if (!knlislocked) 1892 knl->kl_unlock(knl->kl_lockarg); 1893 if (!kqislocked) 1894 KQ_LOCK(kn->kn_kq); 1895 kn->kn_status |= KN_DETACHED; 1896 if (!kqislocked) 1897 KQ_UNLOCK(kn->kn_kq); 1898 } 1899 1900 /* 1901 * remove knote from the specified knlist 1902 */ 1903 void 1904 knlist_remove(struct knlist *knl, struct knote *kn, int islocked) 1905 { 1906 1907 knlist_remove_kq(knl, kn, islocked, 0); 1908 } 1909 1910 /* 1911 * remove knote from the specified knlist while in f_event handler. 1912 */ 1913 void 1914 knlist_remove_inevent(struct knlist *knl, struct knote *kn) 1915 { 1916 1917 knlist_remove_kq(knl, kn, 1, 1918 (kn->kn_status & KN_HASKQLOCK) == KN_HASKQLOCK); 1919 } 1920 1921 int 1922 knlist_empty(struct knlist *knl) 1923 { 1924 1925 KNL_ASSERT_LOCKED(knl); 1926 return SLIST_EMPTY(&knl->kl_list); 1927 } 1928 1929 static struct mtx knlist_lock; 1930 MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects", 1931 MTX_DEF); 1932 static void knlist_mtx_lock(void *arg); 1933 static void knlist_mtx_unlock(void *arg); 1934 1935 static void 1936 knlist_mtx_lock(void *arg) 1937 { 1938 1939 mtx_lock((struct mtx *)arg); 1940 } 1941 1942 static void 1943 knlist_mtx_unlock(void *arg) 1944 { 1945 1946 mtx_unlock((struct mtx *)arg); 1947 } 1948 1949 static void 1950 knlist_mtx_assert_locked(void *arg) 1951 { 1952 1953 mtx_assert((struct mtx *)arg, MA_OWNED); 1954 } 1955 1956 static void 1957 knlist_mtx_assert_unlocked(void *arg) 1958 { 1959 1960 mtx_assert((struct mtx *)arg, MA_NOTOWNED); 1961 } 1962 1963 static void 1964 knlist_rw_rlock(void *arg) 1965 { 1966 1967 rw_rlock((struct rwlock *)arg); 1968 } 1969 1970 static void 1971 knlist_rw_runlock(void *arg) 1972 { 1973 1974 rw_runlock((struct rwlock *)arg); 1975 } 1976 1977 static void 1978 knlist_rw_assert_locked(void *arg) 1979 { 1980 1981 rw_assert((struct rwlock *)arg, RA_LOCKED); 1982 } 1983 1984 static void 1985 knlist_rw_assert_unlocked(void *arg) 1986 { 1987 1988 rw_assert((struct rwlock *)arg, RA_UNLOCKED); 1989 } 1990 1991 void 1992 knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *), 1993 void (*kl_unlock)(void *), 1994 void (*kl_assert_locked)(void *), void (*kl_assert_unlocked)(void *)) 1995 { 1996 1997 if (lock == NULL) 1998 knl->kl_lockarg = &knlist_lock; 1999 else 2000 knl->kl_lockarg = lock; 2001 2002 if (kl_lock == NULL) 2003 knl->kl_lock = knlist_mtx_lock; 2004 else 2005 knl->kl_lock = kl_lock; 2006 if (kl_unlock == NULL) 2007 knl->kl_unlock = knlist_mtx_unlock; 2008 else 2009 knl->kl_unlock = kl_unlock; 2010 if (kl_assert_locked == NULL) 2011 knl->kl_assert_locked = knlist_mtx_assert_locked; 2012 else 2013 knl->kl_assert_locked = kl_assert_locked; 2014 if (kl_assert_unlocked == NULL) 2015 knl->kl_assert_unlocked = knlist_mtx_assert_unlocked; 2016 else 2017 knl->kl_assert_unlocked = kl_assert_unlocked; 2018 2019 SLIST_INIT(&knl->kl_list); 2020 } 2021 2022 void 2023 knlist_init_mtx(struct knlist *knl, struct mtx *lock) 2024 { 2025 2026 knlist_init(knl, lock, NULL, NULL, NULL, NULL); 2027 } 2028 2029 void 2030 knlist_init_rw_reader(struct knlist *knl, struct rwlock *lock) 2031 { 2032 2033 knlist_init(knl, lock, knlist_rw_rlock, knlist_rw_runlock, 2034 knlist_rw_assert_locked, knlist_rw_assert_unlocked); 2035 } 2036 2037 void 2038 knlist_destroy(struct knlist *knl) 2039 { 2040 2041 #ifdef INVARIANTS 2042 /* 2043 * if we run across this error, we need to find the offending 2044 * driver and have it call knlist_clear or knlist_delete. 2045 */ 2046 if (!SLIST_EMPTY(&knl->kl_list)) 2047 printf("WARNING: destroying knlist w/ knotes on it!\n"); 2048 #endif 2049 2050 knl->kl_lockarg = knl->kl_lock = knl->kl_unlock = NULL; 2051 SLIST_INIT(&knl->kl_list); 2052 } 2053 2054 /* 2055 * Even if we are locked, we may need to drop the lock to allow any influx 2056 * knotes time to "settle". 2057 */ 2058 void 2059 knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn) 2060 { 2061 struct knote *kn, *kn2; 2062 struct kqueue *kq; 2063 2064 if (islocked) 2065 KNL_ASSERT_LOCKED(knl); 2066 else { 2067 KNL_ASSERT_UNLOCKED(knl); 2068 again: /* need to reacquire lock since we have dropped it */ 2069 knl->kl_lock(knl->kl_lockarg); 2070 } 2071 2072 SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) { 2073 kq = kn->kn_kq; 2074 KQ_LOCK(kq); 2075 if ((kn->kn_status & KN_INFLUX)) { 2076 KQ_UNLOCK(kq); 2077 continue; 2078 } 2079 knlist_remove_kq(knl, kn, 1, 1); 2080 if (killkn) { 2081 kn->kn_status |= KN_INFLUX | KN_DETACHED; 2082 KQ_UNLOCK(kq); 2083 knote_drop(kn, td); 2084 } else { 2085 /* Make sure cleared knotes disappear soon */ 2086 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 2087 KQ_UNLOCK(kq); 2088 } 2089 kq = NULL; 2090 } 2091 2092 if (!SLIST_EMPTY(&knl->kl_list)) { 2093 /* there are still KN_INFLUX remaining */ 2094 kn = SLIST_FIRST(&knl->kl_list); 2095 kq = kn->kn_kq; 2096 KQ_LOCK(kq); 2097 KASSERT(kn->kn_status & KN_INFLUX, 2098 ("knote removed w/o list lock")); 2099 knl->kl_unlock(knl->kl_lockarg); 2100 kq->kq_state |= KQ_FLUXWAIT; 2101 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0); 2102 kq = NULL; 2103 goto again; 2104 } 2105 2106 if (islocked) 2107 KNL_ASSERT_LOCKED(knl); 2108 else { 2109 knl->kl_unlock(knl->kl_lockarg); 2110 KNL_ASSERT_UNLOCKED(knl); 2111 } 2112 } 2113 2114 /* 2115 * Remove all knotes referencing a specified fd must be called with FILEDESC 2116 * lock. This prevents a race where a new fd comes along and occupies the 2117 * entry and we attach a knote to the fd. 2118 */ 2119 void 2120 knote_fdclose(struct thread *td, int fd) 2121 { 2122 struct filedesc *fdp = td->td_proc->p_fd; 2123 struct kqueue *kq; 2124 struct knote *kn; 2125 int influx; 2126 2127 FILEDESC_XLOCK_ASSERT(fdp); 2128 2129 /* 2130 * We shouldn't have to worry about new kevents appearing on fd 2131 * since filedesc is locked. 2132 */ 2133 TAILQ_FOREACH(kq, &fdp->fd_kqlist, kq_list) { 2134 KQ_LOCK(kq); 2135 2136 again: 2137 influx = 0; 2138 while (kq->kq_knlistsize > fd && 2139 (kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) { 2140 if (kn->kn_status & KN_INFLUX) { 2141 /* someone else might be waiting on our knote */ 2142 if (influx) 2143 wakeup(kq); 2144 kq->kq_state |= KQ_FLUXWAIT; 2145 msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0); 2146 goto again; 2147 } 2148 kn->kn_status |= KN_INFLUX; 2149 KQ_UNLOCK(kq); 2150 if (!(kn->kn_status & KN_DETACHED)) 2151 kn->kn_fop->f_detach(kn); 2152 knote_drop(kn, td); 2153 influx = 1; 2154 KQ_LOCK(kq); 2155 } 2156 KQ_UNLOCK_FLUX(kq); 2157 } 2158 } 2159 2160 static int 2161 knote_attach(struct knote *kn, struct kqueue *kq) 2162 { 2163 struct klist *list; 2164 2165 KASSERT(kn->kn_status & KN_INFLUX, ("knote not marked INFLUX")); 2166 KQ_OWNED(kq); 2167 2168 if (kn->kn_fop->f_isfd) { 2169 if (kn->kn_id >= kq->kq_knlistsize) 2170 return ENOMEM; 2171 list = &kq->kq_knlist[kn->kn_id]; 2172 } else { 2173 if (kq->kq_knhash == NULL) 2174 return ENOMEM; 2175 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2176 } 2177 2178 SLIST_INSERT_HEAD(list, kn, kn_link); 2179 2180 return 0; 2181 } 2182 2183 /* 2184 * knote must already have been detached using the f_detach method. 2185 * no lock need to be held, it is assumed that the KN_INFLUX flag is set 2186 * to prevent other removal. 2187 */ 2188 static void 2189 knote_drop(struct knote *kn, struct thread *td) 2190 { 2191 struct kqueue *kq; 2192 struct klist *list; 2193 2194 kq = kn->kn_kq; 2195 2196 KQ_NOTOWNED(kq); 2197 KASSERT((kn->kn_status & KN_INFLUX) == KN_INFLUX, 2198 ("knote_drop called without KN_INFLUX set in kn_status")); 2199 2200 KQ_LOCK(kq); 2201 if (kn->kn_fop->f_isfd) 2202 list = &kq->kq_knlist[kn->kn_id]; 2203 else 2204 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2205 2206 if (!SLIST_EMPTY(list)) 2207 SLIST_REMOVE(list, kn, knote, kn_link); 2208 if (kn->kn_status & KN_QUEUED) 2209 knote_dequeue(kn); 2210 KQ_UNLOCK_FLUX(kq); 2211 2212 if (kn->kn_fop->f_isfd) { 2213 fdrop(kn->kn_fp, td); 2214 kn->kn_fp = NULL; 2215 } 2216 kqueue_fo_release(kn->kn_kevent.filter); 2217 kn->kn_fop = NULL; 2218 knote_free(kn); 2219 } 2220 2221 static void 2222 knote_enqueue(struct knote *kn) 2223 { 2224 struct kqueue *kq = kn->kn_kq; 2225 2226 KQ_OWNED(kn->kn_kq); 2227 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 2228 2229 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2230 kn->kn_status |= KN_QUEUED; 2231 kq->kq_count++; 2232 kqueue_wakeup(kq); 2233 } 2234 2235 static void 2236 knote_dequeue(struct knote *kn) 2237 { 2238 struct kqueue *kq = kn->kn_kq; 2239 2240 KQ_OWNED(kn->kn_kq); 2241 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 2242 2243 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 2244 kn->kn_status &= ~KN_QUEUED; 2245 kq->kq_count--; 2246 } 2247 2248 static void 2249 knote_init(void) 2250 { 2251 2252 knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL, 2253 NULL, NULL, UMA_ALIGN_PTR, 0); 2254 } 2255 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL); 2256 2257 static struct knote * 2258 knote_alloc(int waitok) 2259 { 2260 return ((struct knote *)uma_zalloc(knote_zone, 2261 (waitok ? M_WAITOK : M_NOWAIT)|M_ZERO)); 2262 } 2263 2264 static void 2265 knote_free(struct knote *kn) 2266 { 2267 if (kn != NULL) 2268 uma_zfree(knote_zone, kn); 2269 } 2270 2271 /* 2272 * Register the kev w/ the kq specified by fd. 2273 */ 2274 int 2275 kqfd_register(int fd, struct kevent *kev, struct thread *td, int waitok) 2276 { 2277 struct kqueue *kq; 2278 struct file *fp; 2279 cap_rights_t rights; 2280 int error; 2281 2282 error = fget(td, fd, cap_rights_init(&rights, CAP_POST_EVENT), &fp); 2283 if (error != 0) 2284 return (error); 2285 if ((error = kqueue_acquire(fp, &kq)) != 0) 2286 goto noacquire; 2287 2288 error = kqueue_register(kq, kev, td, waitok); 2289 2290 kqueue_release(kq, 0); 2291 2292 noacquire: 2293 fdrop(fp, td); 2294 2295 return error; 2296 } 2297