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_compat.h" 33 #include "opt_ktrace.h" 34 #include "opt_kqueue.h" 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/capsicum.h> 39 #include <sys/kernel.h> 40 #include <sys/lock.h> 41 #include <sys/mutex.h> 42 #include <sys/rwlock.h> 43 #include <sys/proc.h> 44 #include <sys/malloc.h> 45 #include <sys/unistd.h> 46 #include <sys/file.h> 47 #include <sys/filedesc.h> 48 #include <sys/filio.h> 49 #include <sys/fcntl.h> 50 #include <sys/kthread.h> 51 #include <sys/selinfo.h> 52 #include <sys/queue.h> 53 #include <sys/event.h> 54 #include <sys/eventvar.h> 55 #include <sys/poll.h> 56 #include <sys/protosw.h> 57 #include <sys/resourcevar.h> 58 #include <sys/sigio.h> 59 #include <sys/signalvar.h> 60 #include <sys/socket.h> 61 #include <sys/socketvar.h> 62 #include <sys/stat.h> 63 #include <sys/sysctl.h> 64 #include <sys/sysproto.h> 65 #include <sys/syscallsubr.h> 66 #include <sys/taskqueue.h> 67 #include <sys/uio.h> 68 #include <sys/user.h> 69 #ifdef KTRACE 70 #include <sys/ktrace.h> 71 #endif 72 #include <machine/atomic.h> 73 74 #include <vm/uma.h> 75 76 static MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system"); 77 78 /* 79 * This lock is used if multiple kq locks are required. This possibly 80 * should be made into a per proc lock. 81 */ 82 static struct mtx kq_global; 83 MTX_SYSINIT(kq_global, &kq_global, "kqueue order", MTX_DEF); 84 #define KQ_GLOBAL_LOCK(lck, haslck) do { \ 85 if (!haslck) \ 86 mtx_lock(lck); \ 87 haslck = 1; \ 88 } while (0) 89 #define KQ_GLOBAL_UNLOCK(lck, haslck) do { \ 90 if (haslck) \ 91 mtx_unlock(lck); \ 92 haslck = 0; \ 93 } while (0) 94 95 TASKQUEUE_DEFINE_THREAD(kqueue_ctx); 96 97 static int kevent_copyout(void *arg, struct kevent *kevp, int count); 98 static int kevent_copyin(void *arg, struct kevent *kevp, int count); 99 static int kqueue_register(struct kqueue *kq, struct kevent *kev, 100 struct thread *td, int waitok); 101 static int kqueue_acquire(struct file *fp, struct kqueue **kqp); 102 static void kqueue_release(struct kqueue *kq, int locked); 103 static void kqueue_destroy(struct kqueue *kq); 104 static void kqueue_drain(struct kqueue *kq, struct thread *td); 105 static int kqueue_expand(struct kqueue *kq, struct filterops *fops, 106 uintptr_t ident, int waitok); 107 static void kqueue_task(void *arg, int pending); 108 static int kqueue_scan(struct kqueue *kq, int maxevents, 109 struct kevent_copyops *k_ops, 110 const struct timespec *timeout, 111 struct kevent *keva, struct thread *td); 112 static void kqueue_wakeup(struct kqueue *kq); 113 static struct filterops *kqueue_fo_find(int filt); 114 static void kqueue_fo_release(int filt); 115 struct g_kevent_args; 116 static int kern_kevent_generic(struct thread *td, 117 struct g_kevent_args *uap, 118 struct kevent_copyops *k_ops); 119 120 static fo_ioctl_t kqueue_ioctl; 121 static fo_poll_t kqueue_poll; 122 static fo_kqfilter_t kqueue_kqfilter; 123 static fo_stat_t kqueue_stat; 124 static fo_close_t kqueue_close; 125 static fo_fill_kinfo_t kqueue_fill_kinfo; 126 127 static struct fileops kqueueops = { 128 .fo_read = invfo_rdwr, 129 .fo_write = invfo_rdwr, 130 .fo_truncate = invfo_truncate, 131 .fo_ioctl = kqueue_ioctl, 132 .fo_poll = kqueue_poll, 133 .fo_kqfilter = kqueue_kqfilter, 134 .fo_stat = kqueue_stat, 135 .fo_close = kqueue_close, 136 .fo_chmod = invfo_chmod, 137 .fo_chown = invfo_chown, 138 .fo_sendfile = invfo_sendfile, 139 .fo_fill_kinfo = kqueue_fill_kinfo, 140 }; 141 142 static int knote_attach(struct knote *kn, struct kqueue *kq); 143 static void knote_drop(struct knote *kn, struct thread *td); 144 static void knote_drop_detached(struct knote *kn, struct thread *td); 145 static void knote_enqueue(struct knote *kn); 146 static void knote_dequeue(struct knote *kn); 147 static void knote_init(void); 148 static struct knote *knote_alloc(int waitok); 149 static void knote_free(struct knote *kn); 150 151 static void filt_kqdetach(struct knote *kn); 152 static int filt_kqueue(struct knote *kn, long hint); 153 static int filt_procattach(struct knote *kn); 154 static void filt_procdetach(struct knote *kn); 155 static int filt_proc(struct knote *kn, long hint); 156 static int filt_fileattach(struct knote *kn); 157 static void filt_timerexpire(void *knx); 158 static int filt_timerattach(struct knote *kn); 159 static void filt_timerdetach(struct knote *kn); 160 static int filt_timer(struct knote *kn, long hint); 161 static int filt_userattach(struct knote *kn); 162 static void filt_userdetach(struct knote *kn); 163 static int filt_user(struct knote *kn, long hint); 164 static void filt_usertouch(struct knote *kn, struct kevent *kev, 165 u_long type); 166 167 static struct filterops file_filtops = { 168 .f_isfd = 1, 169 .f_attach = filt_fileattach, 170 }; 171 static struct filterops kqread_filtops = { 172 .f_isfd = 1, 173 .f_detach = filt_kqdetach, 174 .f_event = filt_kqueue, 175 }; 176 /* XXX - move to kern_proc.c? */ 177 static struct filterops proc_filtops = { 178 .f_isfd = 0, 179 .f_attach = filt_procattach, 180 .f_detach = filt_procdetach, 181 .f_event = filt_proc, 182 }; 183 static struct filterops timer_filtops = { 184 .f_isfd = 0, 185 .f_attach = filt_timerattach, 186 .f_detach = filt_timerdetach, 187 .f_event = filt_timer, 188 }; 189 static struct filterops user_filtops = { 190 .f_attach = filt_userattach, 191 .f_detach = filt_userdetach, 192 .f_event = filt_user, 193 .f_touch = filt_usertouch, 194 }; 195 196 static uma_zone_t knote_zone; 197 static unsigned int kq_ncallouts = 0; 198 static unsigned int kq_calloutmax = 4 * 1024; 199 SYSCTL_UINT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW, 200 &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue"); 201 202 /* XXX - ensure not influx ? */ 203 #define KNOTE_ACTIVATE(kn, islock) do { \ 204 if ((islock)) \ 205 mtx_assert(&(kn)->kn_kq->kq_lock, MA_OWNED); \ 206 else \ 207 KQ_LOCK((kn)->kn_kq); \ 208 (kn)->kn_status |= KN_ACTIVE; \ 209 if (((kn)->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 210 knote_enqueue((kn)); \ 211 if (!(islock)) \ 212 KQ_UNLOCK((kn)->kn_kq); \ 213 } while(0) 214 #define KQ_LOCK(kq) do { \ 215 mtx_lock(&(kq)->kq_lock); \ 216 } while (0) 217 #define KQ_FLUX_WAKEUP(kq) do { \ 218 if (((kq)->kq_state & KQ_FLUXWAIT) == KQ_FLUXWAIT) { \ 219 (kq)->kq_state &= ~KQ_FLUXWAIT; \ 220 wakeup((kq)); \ 221 } \ 222 } while (0) 223 #define KQ_UNLOCK_FLUX(kq) do { \ 224 KQ_FLUX_WAKEUP(kq); \ 225 mtx_unlock(&(kq)->kq_lock); \ 226 } while (0) 227 #define KQ_UNLOCK(kq) do { \ 228 mtx_unlock(&(kq)->kq_lock); \ 229 } while (0) 230 #define KQ_OWNED(kq) do { \ 231 mtx_assert(&(kq)->kq_lock, MA_OWNED); \ 232 } while (0) 233 #define KQ_NOTOWNED(kq) do { \ 234 mtx_assert(&(kq)->kq_lock, MA_NOTOWNED); \ 235 } while (0) 236 237 static struct knlist * 238 kn_list_lock(struct knote *kn) 239 { 240 struct knlist *knl; 241 242 knl = kn->kn_knlist; 243 if (knl != NULL) 244 knl->kl_lock(knl->kl_lockarg); 245 return (knl); 246 } 247 248 static void 249 kn_list_unlock(struct knlist *knl) 250 { 251 bool do_free; 252 253 if (knl == NULL) 254 return; 255 do_free = knl->kl_autodestroy && knlist_empty(knl); 256 knl->kl_unlock(knl->kl_lockarg); 257 if (do_free) { 258 knlist_destroy(knl); 259 free(knl, M_KQUEUE); 260 } 261 } 262 263 static bool 264 kn_in_flux(struct knote *kn) 265 { 266 267 return (kn->kn_influx > 0); 268 } 269 270 static void 271 kn_enter_flux(struct knote *kn) 272 { 273 274 KQ_OWNED(kn->kn_kq); 275 MPASS(kn->kn_influx < INT_MAX); 276 kn->kn_influx++; 277 } 278 279 static bool 280 kn_leave_flux(struct knote *kn) 281 { 282 283 KQ_OWNED(kn->kn_kq); 284 MPASS(kn->kn_influx > 0); 285 kn->kn_influx--; 286 return (kn->kn_influx == 0); 287 } 288 289 #define KNL_ASSERT_LOCK(knl, islocked) do { \ 290 if (islocked) \ 291 KNL_ASSERT_LOCKED(knl); \ 292 else \ 293 KNL_ASSERT_UNLOCKED(knl); \ 294 } while (0) 295 #ifdef INVARIANTS 296 #define KNL_ASSERT_LOCKED(knl) do { \ 297 knl->kl_assert_locked((knl)->kl_lockarg); \ 298 } while (0) 299 #define KNL_ASSERT_UNLOCKED(knl) do { \ 300 knl->kl_assert_unlocked((knl)->kl_lockarg); \ 301 } while (0) 302 #else /* !INVARIANTS */ 303 #define KNL_ASSERT_LOCKED(knl) do {} while(0) 304 #define KNL_ASSERT_UNLOCKED(knl) do {} while (0) 305 #endif /* INVARIANTS */ 306 307 #ifndef KN_HASHSIZE 308 #define KN_HASHSIZE 64 /* XXX should be tunable */ 309 #endif 310 311 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 312 313 static int 314 filt_nullattach(struct knote *kn) 315 { 316 317 return (ENXIO); 318 }; 319 320 struct filterops null_filtops = { 321 .f_isfd = 0, 322 .f_attach = filt_nullattach, 323 }; 324 325 /* XXX - make SYSINIT to add these, and move into respective modules. */ 326 extern struct filterops sig_filtops; 327 extern struct filterops fs_filtops; 328 329 /* 330 * Table for for all system-defined filters. 331 */ 332 static struct mtx filterops_lock; 333 MTX_SYSINIT(kqueue_filterops, &filterops_lock, "protect sysfilt_ops", 334 MTX_DEF); 335 static struct { 336 struct filterops *for_fop; 337 int for_nolock; 338 int for_refcnt; 339 } sysfilt_ops[EVFILT_SYSCOUNT] = { 340 { &file_filtops, 1 }, /* EVFILT_READ */ 341 { &file_filtops, 1 }, /* EVFILT_WRITE */ 342 { &null_filtops }, /* EVFILT_AIO */ 343 { &file_filtops, 1 }, /* EVFILT_VNODE */ 344 { &proc_filtops, 1 }, /* EVFILT_PROC */ 345 { &sig_filtops, 1 }, /* EVFILT_SIGNAL */ 346 { &timer_filtops, 1 }, /* EVFILT_TIMER */ 347 { &file_filtops, 1 }, /* EVFILT_PROCDESC */ 348 { &fs_filtops, 1 }, /* EVFILT_FS */ 349 { &null_filtops }, /* EVFILT_LIO */ 350 { &user_filtops, 1 }, /* EVFILT_USER */ 351 { &null_filtops }, /* EVFILT_SENDFILE */ 352 { &file_filtops, 1 }, /* EVFILT_EMPTY */ 353 }; 354 355 /* 356 * Simple redirection for all cdevsw style objects to call their fo_kqfilter 357 * method. 358 */ 359 static int 360 filt_fileattach(struct knote *kn) 361 { 362 363 return (fo_kqfilter(kn->kn_fp, kn)); 364 } 365 366 /*ARGSUSED*/ 367 static int 368 kqueue_kqfilter(struct file *fp, struct knote *kn) 369 { 370 struct kqueue *kq = kn->kn_fp->f_data; 371 372 if (kn->kn_filter != EVFILT_READ) 373 return (EINVAL); 374 375 kn->kn_status |= KN_KQUEUE; 376 kn->kn_fop = &kqread_filtops; 377 knlist_add(&kq->kq_sel.si_note, kn, 0); 378 379 return (0); 380 } 381 382 static void 383 filt_kqdetach(struct knote *kn) 384 { 385 struct kqueue *kq = kn->kn_fp->f_data; 386 387 knlist_remove(&kq->kq_sel.si_note, kn, 0); 388 } 389 390 /*ARGSUSED*/ 391 static int 392 filt_kqueue(struct knote *kn, long hint) 393 { 394 struct kqueue *kq = kn->kn_fp->f_data; 395 396 kn->kn_data = kq->kq_count; 397 return (kn->kn_data > 0); 398 } 399 400 /* XXX - move to kern_proc.c? */ 401 static int 402 filt_procattach(struct knote *kn) 403 { 404 struct proc *p; 405 int error; 406 bool exiting, immediate; 407 408 exiting = immediate = false; 409 if (kn->kn_sfflags & NOTE_EXIT) 410 p = pfind_any(kn->kn_id); 411 else 412 p = pfind(kn->kn_id); 413 if (p == NULL) 414 return (ESRCH); 415 if (p->p_flag & P_WEXIT) 416 exiting = true; 417 418 if ((error = p_cansee(curthread, p))) { 419 PROC_UNLOCK(p); 420 return (error); 421 } 422 423 kn->kn_ptr.p_proc = p; 424 kn->kn_flags |= EV_CLEAR; /* automatically set */ 425 426 /* 427 * Internal flag indicating registration done by kernel for the 428 * purposes of getting a NOTE_CHILD notification. 429 */ 430 if (kn->kn_flags & EV_FLAG2) { 431 kn->kn_flags &= ~EV_FLAG2; 432 kn->kn_data = kn->kn_sdata; /* ppid */ 433 kn->kn_fflags = NOTE_CHILD; 434 kn->kn_sfflags &= ~(NOTE_EXIT | NOTE_EXEC | NOTE_FORK); 435 immediate = true; /* Force immediate activation of child note. */ 436 } 437 /* 438 * Internal flag indicating registration done by kernel (for other than 439 * NOTE_CHILD). 440 */ 441 if (kn->kn_flags & EV_FLAG1) { 442 kn->kn_flags &= ~EV_FLAG1; 443 } 444 445 knlist_add(p->p_klist, kn, 1); 446 447 /* 448 * Immediately activate any child notes or, in the case of a zombie 449 * target process, exit notes. The latter is necessary to handle the 450 * case where the target process, e.g. a child, dies before the kevent 451 * is registered. 452 */ 453 if (immediate || (exiting && filt_proc(kn, NOTE_EXIT))) 454 KNOTE_ACTIVATE(kn, 0); 455 456 PROC_UNLOCK(p); 457 458 return (0); 459 } 460 461 /* 462 * The knote may be attached to a different process, which may exit, 463 * leaving nothing for the knote to be attached to. So when the process 464 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 465 * it will be deleted when read out. However, as part of the knote deletion, 466 * this routine is called, so a check is needed to avoid actually performing 467 * a detach, because the original process does not exist any more. 468 */ 469 /* XXX - move to kern_proc.c? */ 470 static void 471 filt_procdetach(struct knote *kn) 472 { 473 474 knlist_remove(kn->kn_knlist, kn, 0); 475 kn->kn_ptr.p_proc = NULL; 476 } 477 478 /* XXX - move to kern_proc.c? */ 479 static int 480 filt_proc(struct knote *kn, long hint) 481 { 482 struct proc *p; 483 u_int event; 484 485 p = kn->kn_ptr.p_proc; 486 if (p == NULL) /* already activated, from attach filter */ 487 return (0); 488 489 /* Mask off extra data. */ 490 event = (u_int)hint & NOTE_PCTRLMASK; 491 492 /* If the user is interested in this event, record it. */ 493 if (kn->kn_sfflags & event) 494 kn->kn_fflags |= event; 495 496 /* Process is gone, so flag the event as finished. */ 497 if (event == NOTE_EXIT) { 498 kn->kn_flags |= EV_EOF | EV_ONESHOT; 499 kn->kn_ptr.p_proc = NULL; 500 if (kn->kn_fflags & NOTE_EXIT) 501 kn->kn_data = KW_EXITCODE(p->p_xexit, p->p_xsig); 502 if (kn->kn_fflags == 0) 503 kn->kn_flags |= EV_DROP; 504 return (1); 505 } 506 507 return (kn->kn_fflags != 0); 508 } 509 510 /* 511 * Called when the process forked. It mostly does the same as the 512 * knote(), activating all knotes registered to be activated when the 513 * process forked. Additionally, for each knote attached to the 514 * parent, check whether user wants to track the new process. If so 515 * attach a new knote to it, and immediately report an event with the 516 * child's pid. 517 */ 518 void 519 knote_fork(struct knlist *list, int pid) 520 { 521 struct kqueue *kq; 522 struct knote *kn; 523 struct kevent kev; 524 int error; 525 526 if (list == NULL) 527 return; 528 list->kl_lock(list->kl_lockarg); 529 530 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { 531 kq = kn->kn_kq; 532 KQ_LOCK(kq); 533 if (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0) { 534 KQ_UNLOCK(kq); 535 continue; 536 } 537 538 /* 539 * The same as knote(), activate the event. 540 */ 541 if ((kn->kn_sfflags & NOTE_TRACK) == 0) { 542 kn->kn_status |= KN_HASKQLOCK; 543 if (kn->kn_fop->f_event(kn, NOTE_FORK)) 544 KNOTE_ACTIVATE(kn, 1); 545 kn->kn_status &= ~KN_HASKQLOCK; 546 KQ_UNLOCK(kq); 547 continue; 548 } 549 550 /* 551 * The NOTE_TRACK case. In addition to the activation 552 * of the event, we need to register new events to 553 * track the child. Drop the locks in preparation for 554 * the call to kqueue_register(). 555 */ 556 kn_enter_flux(kn); 557 KQ_UNLOCK(kq); 558 list->kl_unlock(list->kl_lockarg); 559 560 /* 561 * Activate existing knote and register tracking knotes with 562 * new process. 563 * 564 * First register a knote to get just the child notice. This 565 * must be a separate note from a potential NOTE_EXIT 566 * notification since both NOTE_CHILD and NOTE_EXIT are defined 567 * to use the data field (in conflicting ways). 568 */ 569 kev.ident = pid; 570 kev.filter = kn->kn_filter; 571 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_ONESHOT | 572 EV_FLAG2; 573 kev.fflags = kn->kn_sfflags; 574 kev.data = kn->kn_id; /* parent */ 575 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 576 error = kqueue_register(kq, &kev, NULL, 0); 577 if (error) 578 kn->kn_fflags |= NOTE_TRACKERR; 579 580 /* 581 * Then register another knote to track other potential events 582 * from the new process. 583 */ 584 kev.ident = pid; 585 kev.filter = kn->kn_filter; 586 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 587 kev.fflags = kn->kn_sfflags; 588 kev.data = kn->kn_id; /* parent */ 589 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 590 error = kqueue_register(kq, &kev, NULL, 0); 591 if (error) 592 kn->kn_fflags |= NOTE_TRACKERR; 593 if (kn->kn_fop->f_event(kn, NOTE_FORK)) 594 KNOTE_ACTIVATE(kn, 0); 595 KQ_LOCK(kq); 596 kn_leave_flux(kn); 597 KQ_UNLOCK_FLUX(kq); 598 list->kl_lock(list->kl_lockarg); 599 } 600 list->kl_unlock(list->kl_lockarg); 601 } 602 603 /* 604 * XXX: EVFILT_TIMER should perhaps live in kern_time.c beside the 605 * interval timer support code. 606 */ 607 608 #define NOTE_TIMER_PRECMASK \ 609 (NOTE_SECONDS | NOTE_MSECONDS | NOTE_USECONDS | NOTE_NSECONDS) 610 611 static sbintime_t 612 timer2sbintime(intptr_t data, int flags) 613 { 614 int64_t secs; 615 616 /* 617 * Macros for converting to the fractional second portion of an 618 * sbintime_t using 64bit multiplication to improve precision. 619 */ 620 #define NS_TO_SBT(ns) (((ns) * (((uint64_t)1 << 63) / 500000000)) >> 32) 621 #define US_TO_SBT(us) (((us) * (((uint64_t)1 << 63) / 500000)) >> 32) 622 #define MS_TO_SBT(ms) (((ms) * (((uint64_t)1 << 63) / 500)) >> 32) 623 switch (flags & NOTE_TIMER_PRECMASK) { 624 case NOTE_SECONDS: 625 #ifdef __LP64__ 626 if (data > (SBT_MAX / SBT_1S)) 627 return (SBT_MAX); 628 #endif 629 return ((sbintime_t)data << 32); 630 case NOTE_MSECONDS: /* FALLTHROUGH */ 631 case 0: 632 if (data >= 1000) { 633 secs = data / 1000; 634 #ifdef __LP64__ 635 if (secs > (SBT_MAX / SBT_1S)) 636 return (SBT_MAX); 637 #endif 638 return (secs << 32 | MS_TO_SBT(data % 1000)); 639 } 640 return (MS_TO_SBT(data)); 641 case NOTE_USECONDS: 642 if (data >= 1000000) { 643 secs = data / 1000000; 644 #ifdef __LP64__ 645 if (secs > (SBT_MAX / SBT_1S)) 646 return (SBT_MAX); 647 #endif 648 return (secs << 32 | US_TO_SBT(data % 1000000)); 649 } 650 return (US_TO_SBT(data)); 651 case NOTE_NSECONDS: 652 if (data >= 1000000000) { 653 secs = data / 1000000000; 654 #ifdef __LP64__ 655 if (secs > (SBT_MAX / SBT_1S)) 656 return (SBT_MAX); 657 #endif 658 return (secs << 32 | US_TO_SBT(data % 1000000000)); 659 } 660 return (NS_TO_SBT(data)); 661 default: 662 break; 663 } 664 return (-1); 665 } 666 667 struct kq_timer_cb_data { 668 struct callout c; 669 sbintime_t next; /* next timer event fires at */ 670 sbintime_t to; /* precalculated timer period, 0 for abs */ 671 }; 672 673 static void 674 filt_timerexpire(void *knx) 675 { 676 struct knote *kn; 677 struct kq_timer_cb_data *kc; 678 679 kn = knx; 680 kn->kn_data++; 681 KNOTE_ACTIVATE(kn, 0); /* XXX - handle locking */ 682 683 if ((kn->kn_flags & EV_ONESHOT) != 0) 684 return; 685 kc = kn->kn_ptr.p_v; 686 if (kc->to == 0) 687 return; 688 kc->next += kc->to; 689 callout_reset_sbt_on(&kc->c, kc->next, 0, filt_timerexpire, kn, 690 PCPU_GET(cpuid), C_ABSOLUTE); 691 } 692 693 /* 694 * data contains amount of time to sleep 695 */ 696 static int 697 filt_timerattach(struct knote *kn) 698 { 699 struct kq_timer_cb_data *kc; 700 struct bintime bt; 701 sbintime_t to, sbt; 702 unsigned int ncallouts; 703 704 if (kn->kn_sdata < 0) 705 return (EINVAL); 706 if (kn->kn_sdata == 0 && (kn->kn_flags & EV_ONESHOT) == 0) 707 kn->kn_sdata = 1; 708 /* Only precision unit are supported in flags so far */ 709 if ((kn->kn_sfflags & ~(NOTE_TIMER_PRECMASK | NOTE_ABSTIME)) != 0) 710 return (EINVAL); 711 712 to = timer2sbintime(kn->kn_sdata, kn->kn_sfflags); 713 if ((kn->kn_sfflags & NOTE_ABSTIME) != 0) { 714 getboottimebin(&bt); 715 sbt = bttosbt(bt); 716 to -= sbt; 717 } 718 if (to < 0) 719 return (EINVAL); 720 721 do { 722 ncallouts = kq_ncallouts; 723 if (ncallouts >= kq_calloutmax) 724 return (ENOMEM); 725 } while (!atomic_cmpset_int(&kq_ncallouts, ncallouts, ncallouts + 1)); 726 727 if ((kn->kn_sfflags & NOTE_ABSTIME) == 0) 728 kn->kn_flags |= EV_CLEAR; /* automatically set */ 729 kn->kn_status &= ~KN_DETACHED; /* knlist_add clears it */ 730 kn->kn_ptr.p_v = kc = malloc(sizeof(*kc), M_KQUEUE, M_WAITOK); 731 callout_init(&kc->c, 1); 732 if ((kn->kn_sfflags & NOTE_ABSTIME) != 0) { 733 kc->next = to; 734 kc->to = 0; 735 } else { 736 kc->next = to + sbinuptime(); 737 kc->to = to; 738 } 739 callout_reset_sbt_on(&kc->c, kc->next, 0, filt_timerexpire, kn, 740 PCPU_GET(cpuid), C_ABSOLUTE); 741 742 return (0); 743 } 744 745 static void 746 filt_timerdetach(struct knote *kn) 747 { 748 struct kq_timer_cb_data *kc; 749 unsigned int old; 750 751 kc = kn->kn_ptr.p_v; 752 callout_drain(&kc->c); 753 free(kc, M_KQUEUE); 754 old = atomic_fetchadd_int(&kq_ncallouts, -1); 755 KASSERT(old > 0, ("Number of callouts cannot become negative")); 756 kn->kn_status |= KN_DETACHED; /* knlist_remove sets it */ 757 } 758 759 static int 760 filt_timer(struct knote *kn, long hint) 761 { 762 763 return (kn->kn_data != 0); 764 } 765 766 static int 767 filt_userattach(struct knote *kn) 768 { 769 770 /* 771 * EVFILT_USER knotes are not attached to anything in the kernel. 772 */ 773 kn->kn_hook = NULL; 774 if (kn->kn_fflags & NOTE_TRIGGER) 775 kn->kn_hookid = 1; 776 else 777 kn->kn_hookid = 0; 778 return (0); 779 } 780 781 static void 782 filt_userdetach(__unused struct knote *kn) 783 { 784 785 /* 786 * EVFILT_USER knotes are not attached to anything in the kernel. 787 */ 788 } 789 790 static int 791 filt_user(struct knote *kn, __unused long hint) 792 { 793 794 return (kn->kn_hookid); 795 } 796 797 static void 798 filt_usertouch(struct knote *kn, struct kevent *kev, u_long type) 799 { 800 u_int ffctrl; 801 802 switch (type) { 803 case EVENT_REGISTER: 804 if (kev->fflags & NOTE_TRIGGER) 805 kn->kn_hookid = 1; 806 807 ffctrl = kev->fflags & NOTE_FFCTRLMASK; 808 kev->fflags &= NOTE_FFLAGSMASK; 809 switch (ffctrl) { 810 case NOTE_FFNOP: 811 break; 812 813 case NOTE_FFAND: 814 kn->kn_sfflags &= kev->fflags; 815 break; 816 817 case NOTE_FFOR: 818 kn->kn_sfflags |= kev->fflags; 819 break; 820 821 case NOTE_FFCOPY: 822 kn->kn_sfflags = kev->fflags; 823 break; 824 825 default: 826 /* XXX Return error? */ 827 break; 828 } 829 kn->kn_sdata = kev->data; 830 if (kev->flags & EV_CLEAR) { 831 kn->kn_hookid = 0; 832 kn->kn_data = 0; 833 kn->kn_fflags = 0; 834 } 835 break; 836 837 case EVENT_PROCESS: 838 *kev = kn->kn_kevent; 839 kev->fflags = kn->kn_sfflags; 840 kev->data = kn->kn_sdata; 841 if (kn->kn_flags & EV_CLEAR) { 842 kn->kn_hookid = 0; 843 kn->kn_data = 0; 844 kn->kn_fflags = 0; 845 } 846 break; 847 848 default: 849 panic("filt_usertouch() - invalid type (%ld)", type); 850 break; 851 } 852 } 853 854 int 855 sys_kqueue(struct thread *td, struct kqueue_args *uap) 856 { 857 858 return (kern_kqueue(td, 0, NULL)); 859 } 860 861 static void 862 kqueue_init(struct kqueue *kq) 863 { 864 865 mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF | MTX_DUPOK); 866 TAILQ_INIT(&kq->kq_head); 867 knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock); 868 TASK_INIT(&kq->kq_task, 0, kqueue_task, kq); 869 } 870 871 int 872 kern_kqueue(struct thread *td, int flags, struct filecaps *fcaps) 873 { 874 struct filedesc *fdp; 875 struct kqueue *kq; 876 struct file *fp; 877 struct ucred *cred; 878 int fd, error; 879 880 fdp = td->td_proc->p_fd; 881 cred = td->td_ucred; 882 if (!chgkqcnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_KQUEUES))) 883 return (ENOMEM); 884 885 error = falloc_caps(td, &fp, &fd, flags, fcaps); 886 if (error != 0) { 887 chgkqcnt(cred->cr_ruidinfo, -1, 0); 888 return (error); 889 } 890 891 /* An extra reference on `fp' has been held for us by falloc(). */ 892 kq = malloc(sizeof *kq, M_KQUEUE, M_WAITOK | M_ZERO); 893 kqueue_init(kq); 894 kq->kq_fdp = fdp; 895 kq->kq_cred = crhold(cred); 896 897 FILEDESC_XLOCK(fdp); 898 TAILQ_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list); 899 FILEDESC_XUNLOCK(fdp); 900 901 finit(fp, FREAD | FWRITE, DTYPE_KQUEUE, kq, &kqueueops); 902 fdrop(fp, td); 903 904 td->td_retval[0] = fd; 905 return (0); 906 } 907 908 #ifdef KTRACE 909 static size_t 910 kev_iovlen(int n, u_int kgio, size_t kevent_size) 911 { 912 913 if (n < 0 || n >= kgio / kevent_size) 914 return (kgio); 915 return (n * kevent_size); 916 } 917 #endif 918 919 struct g_kevent_args { 920 int fd; 921 void *changelist; 922 int nchanges; 923 void *eventlist; 924 int nevents; 925 const struct timespec *timeout; 926 }; 927 928 int 929 sys_kevent(struct thread *td, struct kevent_args *uap) 930 { 931 struct kevent_copyops k_ops = { 932 .arg = uap, 933 .k_copyout = kevent_copyout, 934 .k_copyin = kevent_copyin, 935 .kevent_size = sizeof(struct kevent), 936 }; 937 struct g_kevent_args gk_args = { 938 .fd = uap->fd, 939 .changelist = uap->changelist, 940 .nchanges = uap->nchanges, 941 .eventlist = uap->eventlist, 942 .nevents = uap->nevents, 943 .timeout = uap->timeout, 944 }; 945 946 return (kern_kevent_generic(td, &gk_args, &k_ops)); 947 } 948 949 static int 950 kern_kevent_generic(struct thread *td, struct g_kevent_args *uap, 951 struct kevent_copyops *k_ops) 952 { 953 struct timespec ts, *tsp; 954 int error; 955 #ifdef KTRACE 956 struct uio ktruio; 957 struct iovec ktriov; 958 struct uio *ktruioin = NULL; 959 struct uio *ktruioout = NULL; 960 u_int kgio; 961 #endif 962 963 if (uap->timeout != NULL) { 964 error = copyin(uap->timeout, &ts, sizeof(ts)); 965 if (error) 966 return (error); 967 tsp = &ts; 968 } else 969 tsp = NULL; 970 971 #ifdef KTRACE 972 if (KTRPOINT(td, KTR_GENIO)) { 973 kgio = ktr_geniosize; 974 ktriov.iov_base = uap->changelist; 975 ktriov.iov_len = kev_iovlen(uap->nchanges, kgio, 976 k_ops->kevent_size); 977 ktruio = (struct uio){ .uio_iov = &ktriov, .uio_iovcnt = 1, 978 .uio_segflg = UIO_USERSPACE, .uio_rw = UIO_READ, 979 .uio_td = td }; 980 ktruioin = cloneuio(&ktruio); 981 ktriov.iov_base = uap->eventlist; 982 ktriov.iov_len = kev_iovlen(uap->nevents, kgio, 983 k_ops->kevent_size); 984 ktriov.iov_len = uap->nevents * k_ops->kevent_size; 985 ktruioout = cloneuio(&ktruio); 986 } 987 #endif 988 989 error = kern_kevent(td, uap->fd, uap->nchanges, uap->nevents, 990 k_ops, tsp); 991 992 #ifdef KTRACE 993 if (ktruioin != NULL) { 994 ktruioin->uio_resid = kev_iovlen(uap->nchanges, kgio, 995 k_ops->kevent_size); 996 ktrgenio(uap->fd, UIO_WRITE, ktruioin, 0); 997 ktruioout->uio_resid = kev_iovlen(td->td_retval[0], kgio, 998 k_ops->kevent_size); 999 ktrgenio(uap->fd, UIO_READ, ktruioout, error); 1000 } 1001 #endif 1002 1003 return (error); 1004 } 1005 1006 /* 1007 * Copy 'count' items into the destination list pointed to by uap->eventlist. 1008 */ 1009 static int 1010 kevent_copyout(void *arg, struct kevent *kevp, int count) 1011 { 1012 struct kevent_args *uap; 1013 int error; 1014 1015 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1016 uap = (struct kevent_args *)arg; 1017 1018 error = copyout(kevp, uap->eventlist, count * sizeof *kevp); 1019 if (error == 0) 1020 uap->eventlist += count; 1021 return (error); 1022 } 1023 1024 /* 1025 * Copy 'count' items from the list pointed to by uap->changelist. 1026 */ 1027 static int 1028 kevent_copyin(void *arg, struct kevent *kevp, int count) 1029 { 1030 struct kevent_args *uap; 1031 int error; 1032 1033 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1034 uap = (struct kevent_args *)arg; 1035 1036 error = copyin(uap->changelist, kevp, count * sizeof *kevp); 1037 if (error == 0) 1038 uap->changelist += count; 1039 return (error); 1040 } 1041 1042 #ifdef COMPAT_FREEBSD11 1043 struct kevent_freebsd11 { 1044 __uintptr_t ident; /* identifier for this event */ 1045 short filter; /* filter for event */ 1046 unsigned short flags; 1047 unsigned int fflags; 1048 __intptr_t data; 1049 void *udata; /* opaque user data identifier */ 1050 }; 1051 1052 static int 1053 kevent11_copyout(void *arg, struct kevent *kevp, int count) 1054 { 1055 struct freebsd11_kevent_args *uap; 1056 struct kevent_freebsd11 kev11; 1057 int error, i; 1058 1059 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1060 uap = (struct freebsd11_kevent_args *)arg; 1061 1062 for (i = 0; i < count; i++) { 1063 kev11.ident = kevp->ident; 1064 kev11.filter = kevp->filter; 1065 kev11.flags = kevp->flags; 1066 kev11.fflags = kevp->fflags; 1067 kev11.data = kevp->data; 1068 kev11.udata = kevp->udata; 1069 error = copyout(&kev11, uap->eventlist, sizeof(kev11)); 1070 if (error != 0) 1071 break; 1072 uap->eventlist++; 1073 kevp++; 1074 } 1075 return (error); 1076 } 1077 1078 /* 1079 * Copy 'count' items from the list pointed to by uap->changelist. 1080 */ 1081 static int 1082 kevent11_copyin(void *arg, struct kevent *kevp, int count) 1083 { 1084 struct freebsd11_kevent_args *uap; 1085 struct kevent_freebsd11 kev11; 1086 int error, i; 1087 1088 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1089 uap = (struct freebsd11_kevent_args *)arg; 1090 1091 for (i = 0; i < count; i++) { 1092 error = copyin(uap->changelist, &kev11, sizeof(kev11)); 1093 if (error != 0) 1094 break; 1095 kevp->ident = kev11.ident; 1096 kevp->filter = kev11.filter; 1097 kevp->flags = kev11.flags; 1098 kevp->fflags = kev11.fflags; 1099 kevp->data = (uintptr_t)kev11.data; 1100 kevp->udata = kev11.udata; 1101 bzero(&kevp->ext, sizeof(kevp->ext)); 1102 uap->changelist++; 1103 kevp++; 1104 } 1105 return (error); 1106 } 1107 1108 int 1109 freebsd11_kevent(struct thread *td, struct freebsd11_kevent_args *uap) 1110 { 1111 struct kevent_copyops k_ops = { 1112 .arg = uap, 1113 .k_copyout = kevent11_copyout, 1114 .k_copyin = kevent11_copyin, 1115 .kevent_size = sizeof(struct kevent_freebsd11), 1116 }; 1117 struct g_kevent_args gk_args = { 1118 .fd = uap->fd, 1119 .changelist = uap->changelist, 1120 .nchanges = uap->nchanges, 1121 .eventlist = uap->eventlist, 1122 .nevents = uap->nevents, 1123 .timeout = uap->timeout, 1124 }; 1125 1126 return (kern_kevent_generic(td, &gk_args, &k_ops)); 1127 } 1128 #endif 1129 1130 int 1131 kern_kevent(struct thread *td, int fd, int nchanges, int nevents, 1132 struct kevent_copyops *k_ops, const struct timespec *timeout) 1133 { 1134 cap_rights_t rights; 1135 struct file *fp; 1136 int error; 1137 1138 cap_rights_init(&rights); 1139 if (nchanges > 0) 1140 cap_rights_set(&rights, CAP_KQUEUE_CHANGE); 1141 if (nevents > 0) 1142 cap_rights_set(&rights, CAP_KQUEUE_EVENT); 1143 error = fget(td, fd, &rights, &fp); 1144 if (error != 0) 1145 return (error); 1146 1147 error = kern_kevent_fp(td, fp, nchanges, nevents, k_ops, timeout); 1148 fdrop(fp, td); 1149 1150 return (error); 1151 } 1152 1153 static int 1154 kqueue_kevent(struct kqueue *kq, struct thread *td, int nchanges, int nevents, 1155 struct kevent_copyops *k_ops, const struct timespec *timeout) 1156 { 1157 struct kevent keva[KQ_NEVENTS]; 1158 struct kevent *kevp, *changes; 1159 int i, n, nerrors, error; 1160 1161 nerrors = 0; 1162 while (nchanges > 0) { 1163 n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges; 1164 error = k_ops->k_copyin(k_ops->arg, keva, n); 1165 if (error) 1166 return (error); 1167 changes = keva; 1168 for (i = 0; i < n; i++) { 1169 kevp = &changes[i]; 1170 if (!kevp->filter) 1171 continue; 1172 kevp->flags &= ~EV_SYSFLAGS; 1173 error = kqueue_register(kq, kevp, td, 1); 1174 if (error || (kevp->flags & EV_RECEIPT)) { 1175 if (nevents == 0) 1176 return (error); 1177 kevp->flags = EV_ERROR; 1178 kevp->data = error; 1179 (void)k_ops->k_copyout(k_ops->arg, kevp, 1); 1180 nevents--; 1181 nerrors++; 1182 } 1183 } 1184 nchanges -= n; 1185 } 1186 if (nerrors) { 1187 td->td_retval[0] = nerrors; 1188 return (0); 1189 } 1190 1191 return (kqueue_scan(kq, nevents, k_ops, timeout, keva, td)); 1192 } 1193 1194 int 1195 kern_kevent_fp(struct thread *td, struct file *fp, int nchanges, int nevents, 1196 struct kevent_copyops *k_ops, const struct timespec *timeout) 1197 { 1198 struct kqueue *kq; 1199 int error; 1200 1201 error = kqueue_acquire(fp, &kq); 1202 if (error != 0) 1203 return (error); 1204 error = kqueue_kevent(kq, td, nchanges, nevents, k_ops, timeout); 1205 kqueue_release(kq, 0); 1206 return (error); 1207 } 1208 1209 /* 1210 * Performs a kevent() call on a temporarily created kqueue. This can be 1211 * used to perform one-shot polling, similar to poll() and select(). 1212 */ 1213 int 1214 kern_kevent_anonymous(struct thread *td, int nevents, 1215 struct kevent_copyops *k_ops) 1216 { 1217 struct kqueue kq = {}; 1218 int error; 1219 1220 kqueue_init(&kq); 1221 kq.kq_refcnt = 1; 1222 error = kqueue_kevent(&kq, td, nevents, nevents, k_ops, NULL); 1223 kqueue_drain(&kq, td); 1224 kqueue_destroy(&kq); 1225 return (error); 1226 } 1227 1228 int 1229 kqueue_add_filteropts(int filt, struct filterops *filtops) 1230 { 1231 int error; 1232 1233 error = 0; 1234 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) { 1235 printf( 1236 "trying to add a filterop that is out of range: %d is beyond %d\n", 1237 ~filt, EVFILT_SYSCOUNT); 1238 return EINVAL; 1239 } 1240 mtx_lock(&filterops_lock); 1241 if (sysfilt_ops[~filt].for_fop != &null_filtops && 1242 sysfilt_ops[~filt].for_fop != NULL) 1243 error = EEXIST; 1244 else { 1245 sysfilt_ops[~filt].for_fop = filtops; 1246 sysfilt_ops[~filt].for_refcnt = 0; 1247 } 1248 mtx_unlock(&filterops_lock); 1249 1250 return (error); 1251 } 1252 1253 int 1254 kqueue_del_filteropts(int filt) 1255 { 1256 int error; 1257 1258 error = 0; 1259 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1260 return EINVAL; 1261 1262 mtx_lock(&filterops_lock); 1263 if (sysfilt_ops[~filt].for_fop == &null_filtops || 1264 sysfilt_ops[~filt].for_fop == NULL) 1265 error = EINVAL; 1266 else if (sysfilt_ops[~filt].for_refcnt != 0) 1267 error = EBUSY; 1268 else { 1269 sysfilt_ops[~filt].for_fop = &null_filtops; 1270 sysfilt_ops[~filt].for_refcnt = 0; 1271 } 1272 mtx_unlock(&filterops_lock); 1273 1274 return error; 1275 } 1276 1277 static struct filterops * 1278 kqueue_fo_find(int filt) 1279 { 1280 1281 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1282 return NULL; 1283 1284 if (sysfilt_ops[~filt].for_nolock) 1285 return sysfilt_ops[~filt].for_fop; 1286 1287 mtx_lock(&filterops_lock); 1288 sysfilt_ops[~filt].for_refcnt++; 1289 if (sysfilt_ops[~filt].for_fop == NULL) 1290 sysfilt_ops[~filt].for_fop = &null_filtops; 1291 mtx_unlock(&filterops_lock); 1292 1293 return sysfilt_ops[~filt].for_fop; 1294 } 1295 1296 static void 1297 kqueue_fo_release(int filt) 1298 { 1299 1300 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1301 return; 1302 1303 if (sysfilt_ops[~filt].for_nolock) 1304 return; 1305 1306 mtx_lock(&filterops_lock); 1307 KASSERT(sysfilt_ops[~filt].for_refcnt > 0, 1308 ("filter object refcount not valid on release")); 1309 sysfilt_ops[~filt].for_refcnt--; 1310 mtx_unlock(&filterops_lock); 1311 } 1312 1313 /* 1314 * A ref to kq (obtained via kqueue_acquire) must be held. waitok will 1315 * influence if memory allocation should wait. Make sure it is 0 if you 1316 * hold any mutexes. 1317 */ 1318 static int 1319 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, int waitok) 1320 { 1321 struct filterops *fops; 1322 struct file *fp; 1323 struct knote *kn, *tkn; 1324 struct knlist *knl; 1325 cap_rights_t rights; 1326 int error, filt, event; 1327 int haskqglobal, filedesc_unlock; 1328 1329 if ((kev->flags & (EV_ENABLE | EV_DISABLE)) == (EV_ENABLE | EV_DISABLE)) 1330 return (EINVAL); 1331 1332 fp = NULL; 1333 kn = NULL; 1334 knl = NULL; 1335 error = 0; 1336 haskqglobal = 0; 1337 filedesc_unlock = 0; 1338 1339 filt = kev->filter; 1340 fops = kqueue_fo_find(filt); 1341 if (fops == NULL) 1342 return EINVAL; 1343 1344 if (kev->flags & EV_ADD) { 1345 /* 1346 * Prevent waiting with locks. Non-sleepable 1347 * allocation failures are handled in the loop, only 1348 * if the spare knote appears to be actually required. 1349 */ 1350 tkn = knote_alloc(waitok); 1351 } else { 1352 tkn = NULL; 1353 } 1354 1355 findkn: 1356 if (fops->f_isfd) { 1357 KASSERT(td != NULL, ("td is NULL")); 1358 if (kev->ident > INT_MAX) 1359 error = EBADF; 1360 else 1361 error = fget(td, kev->ident, 1362 cap_rights_init(&rights, CAP_EVENT), &fp); 1363 if (error) 1364 goto done; 1365 1366 if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops, 1367 kev->ident, 0) != 0) { 1368 /* try again */ 1369 fdrop(fp, td); 1370 fp = NULL; 1371 error = kqueue_expand(kq, fops, kev->ident, waitok); 1372 if (error) 1373 goto done; 1374 goto findkn; 1375 } 1376 1377 if (fp->f_type == DTYPE_KQUEUE) { 1378 /* 1379 * If we add some intelligence about what we are doing, 1380 * we should be able to support events on ourselves. 1381 * We need to know when we are doing this to prevent 1382 * getting both the knlist lock and the kq lock since 1383 * they are the same thing. 1384 */ 1385 if (fp->f_data == kq) { 1386 error = EINVAL; 1387 goto done; 1388 } 1389 1390 /* 1391 * Pre-lock the filedesc before the global 1392 * lock mutex, see the comment in 1393 * kqueue_close(). 1394 */ 1395 FILEDESC_XLOCK(td->td_proc->p_fd); 1396 filedesc_unlock = 1; 1397 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1398 } 1399 1400 KQ_LOCK(kq); 1401 if (kev->ident < kq->kq_knlistsize) { 1402 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link) 1403 if (kev->filter == kn->kn_filter) 1404 break; 1405 } 1406 } else { 1407 if ((kev->flags & EV_ADD) == EV_ADD) 1408 kqueue_expand(kq, fops, kev->ident, waitok); 1409 1410 KQ_LOCK(kq); 1411 1412 /* 1413 * If possible, find an existing knote to use for this kevent. 1414 */ 1415 if (kev->filter == EVFILT_PROC && 1416 (kev->flags & (EV_FLAG1 | EV_FLAG2)) != 0) { 1417 /* This is an internal creation of a process tracking 1418 * note. Don't attempt to coalesce this with an 1419 * existing note. 1420 */ 1421 ; 1422 } else if (kq->kq_knhashmask != 0) { 1423 struct klist *list; 1424 1425 list = &kq->kq_knhash[ 1426 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)]; 1427 SLIST_FOREACH(kn, list, kn_link) 1428 if (kev->ident == kn->kn_id && 1429 kev->filter == kn->kn_filter) 1430 break; 1431 } 1432 } 1433 1434 /* knote is in the process of changing, wait for it to stabilize. */ 1435 if (kn != NULL && kn_in_flux(kn)) { 1436 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1437 if (filedesc_unlock) { 1438 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1439 filedesc_unlock = 0; 1440 } 1441 kq->kq_state |= KQ_FLUXWAIT; 1442 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0); 1443 if (fp != NULL) { 1444 fdrop(fp, td); 1445 fp = NULL; 1446 } 1447 goto findkn; 1448 } 1449 1450 /* 1451 * kn now contains the matching knote, or NULL if no match 1452 */ 1453 if (kn == NULL) { 1454 if (kev->flags & EV_ADD) { 1455 kn = tkn; 1456 tkn = NULL; 1457 if (kn == NULL) { 1458 KQ_UNLOCK(kq); 1459 error = ENOMEM; 1460 goto done; 1461 } 1462 kn->kn_fp = fp; 1463 kn->kn_kq = kq; 1464 kn->kn_fop = fops; 1465 /* 1466 * apply reference counts to knote structure, and 1467 * do not release it at the end of this routine. 1468 */ 1469 fops = NULL; 1470 fp = NULL; 1471 1472 kn->kn_sfflags = kev->fflags; 1473 kn->kn_sdata = kev->data; 1474 kev->fflags = 0; 1475 kev->data = 0; 1476 kn->kn_kevent = *kev; 1477 kn->kn_kevent.flags &= ~(EV_ADD | EV_DELETE | 1478 EV_ENABLE | EV_DISABLE | EV_FORCEONESHOT); 1479 kn->kn_status = KN_DETACHED; 1480 kn_enter_flux(kn); 1481 1482 error = knote_attach(kn, kq); 1483 KQ_UNLOCK(kq); 1484 if (error != 0) { 1485 tkn = kn; 1486 goto done; 1487 } 1488 1489 if ((error = kn->kn_fop->f_attach(kn)) != 0) { 1490 knote_drop_detached(kn, td); 1491 goto done; 1492 } 1493 knl = kn_list_lock(kn); 1494 goto done_ev_add; 1495 } else { 1496 /* No matching knote and the EV_ADD flag is not set. */ 1497 KQ_UNLOCK(kq); 1498 error = ENOENT; 1499 goto done; 1500 } 1501 } 1502 1503 if (kev->flags & EV_DELETE) { 1504 kn_enter_flux(kn); 1505 KQ_UNLOCK(kq); 1506 knote_drop(kn, td); 1507 goto done; 1508 } 1509 1510 if (kev->flags & EV_FORCEONESHOT) { 1511 kn->kn_flags |= EV_ONESHOT; 1512 KNOTE_ACTIVATE(kn, 1); 1513 } 1514 1515 /* 1516 * The user may change some filter values after the initial EV_ADD, 1517 * but doing so will not reset any filter which has already been 1518 * triggered. 1519 */ 1520 kn->kn_status |= KN_SCAN; 1521 kn_enter_flux(kn); 1522 KQ_UNLOCK(kq); 1523 knl = kn_list_lock(kn); 1524 kn->kn_kevent.udata = kev->udata; 1525 if (!fops->f_isfd && fops->f_touch != NULL) { 1526 fops->f_touch(kn, kev, EVENT_REGISTER); 1527 } else { 1528 kn->kn_sfflags = kev->fflags; 1529 kn->kn_sdata = kev->data; 1530 } 1531 1532 /* 1533 * We can get here with kn->kn_knlist == NULL. This can happen when 1534 * the initial attach event decides that the event is "completed" 1535 * already. i.e. filt_procattach is called on a zombie process. It 1536 * will call filt_proc which will remove it from the list, and NULL 1537 * kn_knlist. 1538 */ 1539 done_ev_add: 1540 if ((kev->flags & EV_ENABLE) != 0) 1541 kn->kn_status &= ~KN_DISABLED; 1542 else if ((kev->flags & EV_DISABLE) != 0) 1543 kn->kn_status |= KN_DISABLED; 1544 1545 if ((kn->kn_status & KN_DISABLED) == 0) 1546 event = kn->kn_fop->f_event(kn, 0); 1547 else 1548 event = 0; 1549 1550 KQ_LOCK(kq); 1551 if (event) 1552 kn->kn_status |= KN_ACTIVE; 1553 if ((kn->kn_status & (KN_ACTIVE | KN_DISABLED | KN_QUEUED)) == 1554 KN_ACTIVE) 1555 knote_enqueue(kn); 1556 kn->kn_status &= ~KN_SCAN; 1557 kn_leave_flux(kn); 1558 kn_list_unlock(knl); 1559 KQ_UNLOCK_FLUX(kq); 1560 1561 done: 1562 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1563 if (filedesc_unlock) 1564 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1565 if (fp != NULL) 1566 fdrop(fp, td); 1567 knote_free(tkn); 1568 if (fops != NULL) 1569 kqueue_fo_release(filt); 1570 return (error); 1571 } 1572 1573 static int 1574 kqueue_acquire(struct file *fp, struct kqueue **kqp) 1575 { 1576 int error; 1577 struct kqueue *kq; 1578 1579 error = 0; 1580 1581 kq = fp->f_data; 1582 if (fp->f_type != DTYPE_KQUEUE || kq == NULL) 1583 return (EBADF); 1584 *kqp = kq; 1585 KQ_LOCK(kq); 1586 if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) { 1587 KQ_UNLOCK(kq); 1588 return (EBADF); 1589 } 1590 kq->kq_refcnt++; 1591 KQ_UNLOCK(kq); 1592 1593 return error; 1594 } 1595 1596 static void 1597 kqueue_release(struct kqueue *kq, int locked) 1598 { 1599 if (locked) 1600 KQ_OWNED(kq); 1601 else 1602 KQ_LOCK(kq); 1603 kq->kq_refcnt--; 1604 if (kq->kq_refcnt == 1) 1605 wakeup(&kq->kq_refcnt); 1606 if (!locked) 1607 KQ_UNLOCK(kq); 1608 } 1609 1610 static void 1611 kqueue_schedtask(struct kqueue *kq) 1612 { 1613 1614 KQ_OWNED(kq); 1615 KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN), 1616 ("scheduling kqueue task while draining")); 1617 1618 if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) { 1619 taskqueue_enqueue(taskqueue_kqueue_ctx, &kq->kq_task); 1620 kq->kq_state |= KQ_TASKSCHED; 1621 } 1622 } 1623 1624 /* 1625 * Expand the kq to make sure we have storage for fops/ident pair. 1626 * 1627 * Return 0 on success (or no work necessary), return errno on failure. 1628 * 1629 * Not calling hashinit w/ waitok (proper malloc flag) should be safe. 1630 * If kqueue_register is called from a non-fd context, there usually/should 1631 * be no locks held. 1632 */ 1633 static int 1634 kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident, 1635 int waitok) 1636 { 1637 struct klist *list, *tmp_knhash, *to_free; 1638 u_long tmp_knhashmask; 1639 int size; 1640 int fd; 1641 int mflag = waitok ? M_WAITOK : M_NOWAIT; 1642 1643 KQ_NOTOWNED(kq); 1644 1645 to_free = NULL; 1646 if (fops->f_isfd) { 1647 fd = ident; 1648 if (kq->kq_knlistsize <= fd) { 1649 size = kq->kq_knlistsize; 1650 while (size <= fd) 1651 size += KQEXTENT; 1652 list = malloc(size * sizeof(*list), M_KQUEUE, mflag); 1653 if (list == NULL) 1654 return ENOMEM; 1655 KQ_LOCK(kq); 1656 if (kq->kq_knlistsize > fd) { 1657 to_free = list; 1658 list = NULL; 1659 } else { 1660 if (kq->kq_knlist != NULL) { 1661 bcopy(kq->kq_knlist, list, 1662 kq->kq_knlistsize * sizeof(*list)); 1663 to_free = kq->kq_knlist; 1664 kq->kq_knlist = NULL; 1665 } 1666 bzero((caddr_t)list + 1667 kq->kq_knlistsize * sizeof(*list), 1668 (size - kq->kq_knlistsize) * sizeof(*list)); 1669 kq->kq_knlistsize = size; 1670 kq->kq_knlist = list; 1671 } 1672 KQ_UNLOCK(kq); 1673 } 1674 } else { 1675 if (kq->kq_knhashmask == 0) { 1676 tmp_knhash = hashinit(KN_HASHSIZE, M_KQUEUE, 1677 &tmp_knhashmask); 1678 if (tmp_knhash == NULL) 1679 return ENOMEM; 1680 KQ_LOCK(kq); 1681 if (kq->kq_knhashmask == 0) { 1682 kq->kq_knhash = tmp_knhash; 1683 kq->kq_knhashmask = tmp_knhashmask; 1684 } else { 1685 to_free = tmp_knhash; 1686 } 1687 KQ_UNLOCK(kq); 1688 } 1689 } 1690 free(to_free, M_KQUEUE); 1691 1692 KQ_NOTOWNED(kq); 1693 return 0; 1694 } 1695 1696 static void 1697 kqueue_task(void *arg, int pending) 1698 { 1699 struct kqueue *kq; 1700 int haskqglobal; 1701 1702 haskqglobal = 0; 1703 kq = arg; 1704 1705 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1706 KQ_LOCK(kq); 1707 1708 KNOTE_LOCKED(&kq->kq_sel.si_note, 0); 1709 1710 kq->kq_state &= ~KQ_TASKSCHED; 1711 if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) { 1712 wakeup(&kq->kq_state); 1713 } 1714 KQ_UNLOCK(kq); 1715 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1716 } 1717 1718 /* 1719 * Scan, update kn_data (if not ONESHOT), and copyout triggered events. 1720 * We treat KN_MARKER knotes as if they are in flux. 1721 */ 1722 static int 1723 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops, 1724 const struct timespec *tsp, struct kevent *keva, struct thread *td) 1725 { 1726 struct kevent *kevp; 1727 struct knote *kn, *marker; 1728 struct knlist *knl; 1729 sbintime_t asbt, rsbt; 1730 int count, error, haskqglobal, influx, nkev, touch; 1731 1732 count = maxevents; 1733 nkev = 0; 1734 error = 0; 1735 haskqglobal = 0; 1736 1737 if (maxevents == 0) 1738 goto done_nl; 1739 1740 rsbt = 0; 1741 if (tsp != NULL) { 1742 if (tsp->tv_sec < 0 || tsp->tv_nsec < 0 || 1743 tsp->tv_nsec >= 1000000000) { 1744 error = EINVAL; 1745 goto done_nl; 1746 } 1747 if (timespecisset(tsp)) { 1748 if (tsp->tv_sec <= INT32_MAX) { 1749 rsbt = tstosbt(*tsp); 1750 if (TIMESEL(&asbt, rsbt)) 1751 asbt += tc_tick_sbt; 1752 if (asbt <= SBT_MAX - rsbt) 1753 asbt += rsbt; 1754 else 1755 asbt = 0; 1756 rsbt >>= tc_precexp; 1757 } else 1758 asbt = 0; 1759 } else 1760 asbt = -1; 1761 } else 1762 asbt = 0; 1763 marker = knote_alloc(1); 1764 marker->kn_status = KN_MARKER; 1765 KQ_LOCK(kq); 1766 1767 retry: 1768 kevp = keva; 1769 if (kq->kq_count == 0) { 1770 if (asbt == -1) { 1771 error = EWOULDBLOCK; 1772 } else { 1773 kq->kq_state |= KQ_SLEEP; 1774 error = msleep_sbt(kq, &kq->kq_lock, PSOCK | PCATCH, 1775 "kqread", asbt, rsbt, C_ABSOLUTE); 1776 } 1777 if (error == 0) 1778 goto retry; 1779 /* don't restart after signals... */ 1780 if (error == ERESTART) 1781 error = EINTR; 1782 else if (error == EWOULDBLOCK) 1783 error = 0; 1784 goto done; 1785 } 1786 1787 TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); 1788 influx = 0; 1789 while (count) { 1790 KQ_OWNED(kq); 1791 kn = TAILQ_FIRST(&kq->kq_head); 1792 1793 if ((kn->kn_status == KN_MARKER && kn != marker) || 1794 kn_in_flux(kn)) { 1795 if (influx) { 1796 influx = 0; 1797 KQ_FLUX_WAKEUP(kq); 1798 } 1799 kq->kq_state |= KQ_FLUXWAIT; 1800 error = msleep(kq, &kq->kq_lock, PSOCK, 1801 "kqflxwt", 0); 1802 continue; 1803 } 1804 1805 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1806 if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) { 1807 kn->kn_status &= ~KN_QUEUED; 1808 kq->kq_count--; 1809 continue; 1810 } 1811 if (kn == marker) { 1812 KQ_FLUX_WAKEUP(kq); 1813 if (count == maxevents) 1814 goto retry; 1815 goto done; 1816 } 1817 KASSERT(!kn_in_flux(kn), 1818 ("knote %p is unexpectedly in flux", kn)); 1819 1820 if ((kn->kn_flags & EV_DROP) == EV_DROP) { 1821 kn->kn_status &= ~KN_QUEUED; 1822 kn_enter_flux(kn); 1823 kq->kq_count--; 1824 KQ_UNLOCK(kq); 1825 /* 1826 * We don't need to lock the list since we've 1827 * marked it as in flux. 1828 */ 1829 knote_drop(kn, td); 1830 KQ_LOCK(kq); 1831 continue; 1832 } else if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) { 1833 kn->kn_status &= ~KN_QUEUED; 1834 kn_enter_flux(kn); 1835 kq->kq_count--; 1836 KQ_UNLOCK(kq); 1837 /* 1838 * We don't need to lock the list since we've 1839 * marked the knote as being in flux. 1840 */ 1841 *kevp = kn->kn_kevent; 1842 knote_drop(kn, td); 1843 KQ_LOCK(kq); 1844 kn = NULL; 1845 } else { 1846 kn->kn_status |= KN_SCAN; 1847 kn_enter_flux(kn); 1848 KQ_UNLOCK(kq); 1849 if ((kn->kn_status & KN_KQUEUE) == KN_KQUEUE) 1850 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1851 knl = kn_list_lock(kn); 1852 if (kn->kn_fop->f_event(kn, 0) == 0) { 1853 KQ_LOCK(kq); 1854 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1855 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE | 1856 KN_SCAN); 1857 kn_leave_flux(kn); 1858 kq->kq_count--; 1859 kn_list_unlock(knl); 1860 influx = 1; 1861 continue; 1862 } 1863 touch = (!kn->kn_fop->f_isfd && 1864 kn->kn_fop->f_touch != NULL); 1865 if (touch) 1866 kn->kn_fop->f_touch(kn, kevp, EVENT_PROCESS); 1867 else 1868 *kevp = kn->kn_kevent; 1869 KQ_LOCK(kq); 1870 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1871 if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) { 1872 /* 1873 * Manually clear knotes who weren't 1874 * 'touch'ed. 1875 */ 1876 if (touch == 0 && kn->kn_flags & EV_CLEAR) { 1877 kn->kn_data = 0; 1878 kn->kn_fflags = 0; 1879 } 1880 if (kn->kn_flags & EV_DISPATCH) 1881 kn->kn_status |= KN_DISABLED; 1882 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 1883 kq->kq_count--; 1884 } else 1885 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 1886 1887 kn->kn_status &= ~KN_SCAN; 1888 kn_leave_flux(kn); 1889 kn_list_unlock(knl); 1890 influx = 1; 1891 } 1892 1893 /* we are returning a copy to the user */ 1894 kevp++; 1895 nkev++; 1896 count--; 1897 1898 if (nkev == KQ_NEVENTS) { 1899 influx = 0; 1900 KQ_UNLOCK_FLUX(kq); 1901 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1902 nkev = 0; 1903 kevp = keva; 1904 KQ_LOCK(kq); 1905 if (error) 1906 break; 1907 } 1908 } 1909 TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); 1910 done: 1911 KQ_OWNED(kq); 1912 KQ_UNLOCK_FLUX(kq); 1913 knote_free(marker); 1914 done_nl: 1915 KQ_NOTOWNED(kq); 1916 if (nkev != 0) 1917 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1918 td->td_retval[0] = maxevents - count; 1919 return (error); 1920 } 1921 1922 /*ARGSUSED*/ 1923 static int 1924 kqueue_ioctl(struct file *fp, u_long cmd, void *data, 1925 struct ucred *active_cred, struct thread *td) 1926 { 1927 /* 1928 * Enabling sigio causes two major problems: 1929 * 1) infinite recursion: 1930 * Synopsys: kevent is being used to track signals and have FIOASYNC 1931 * set. On receipt of a signal this will cause a kqueue to recurse 1932 * into itself over and over. Sending the sigio causes the kqueue 1933 * to become ready, which in turn posts sigio again, forever. 1934 * Solution: this can be solved by setting a flag in the kqueue that 1935 * we have a SIGIO in progress. 1936 * 2) locking problems: 1937 * Synopsys: Kqueue is a leaf subsystem, but adding signalling puts 1938 * us above the proc and pgrp locks. 1939 * Solution: Post a signal using an async mechanism, being sure to 1940 * record a generation count in the delivery so that we do not deliver 1941 * a signal to the wrong process. 1942 * 1943 * Note, these two mechanisms are somewhat mutually exclusive! 1944 */ 1945 #if 0 1946 struct kqueue *kq; 1947 1948 kq = fp->f_data; 1949 switch (cmd) { 1950 case FIOASYNC: 1951 if (*(int *)data) { 1952 kq->kq_state |= KQ_ASYNC; 1953 } else { 1954 kq->kq_state &= ~KQ_ASYNC; 1955 } 1956 return (0); 1957 1958 case FIOSETOWN: 1959 return (fsetown(*(int *)data, &kq->kq_sigio)); 1960 1961 case FIOGETOWN: 1962 *(int *)data = fgetown(&kq->kq_sigio); 1963 return (0); 1964 } 1965 #endif 1966 1967 return (ENOTTY); 1968 } 1969 1970 /*ARGSUSED*/ 1971 static int 1972 kqueue_poll(struct file *fp, int events, struct ucred *active_cred, 1973 struct thread *td) 1974 { 1975 struct kqueue *kq; 1976 int revents = 0; 1977 int error; 1978 1979 if ((error = kqueue_acquire(fp, &kq))) 1980 return POLLERR; 1981 1982 KQ_LOCK(kq); 1983 if (events & (POLLIN | POLLRDNORM)) { 1984 if (kq->kq_count) { 1985 revents |= events & (POLLIN | POLLRDNORM); 1986 } else { 1987 selrecord(td, &kq->kq_sel); 1988 if (SEL_WAITING(&kq->kq_sel)) 1989 kq->kq_state |= KQ_SEL; 1990 } 1991 } 1992 kqueue_release(kq, 1); 1993 KQ_UNLOCK(kq); 1994 return (revents); 1995 } 1996 1997 /*ARGSUSED*/ 1998 static int 1999 kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred, 2000 struct thread *td) 2001 { 2002 2003 bzero((void *)st, sizeof *st); 2004 /* 2005 * We no longer return kq_count because the unlocked value is useless. 2006 * If you spent all this time getting the count, why not spend your 2007 * syscall better by calling kevent? 2008 * 2009 * XXX - This is needed for libc_r. 2010 */ 2011 st->st_mode = S_IFIFO; 2012 return (0); 2013 } 2014 2015 static void 2016 kqueue_drain(struct kqueue *kq, struct thread *td) 2017 { 2018 struct knote *kn; 2019 int i; 2020 2021 KQ_LOCK(kq); 2022 2023 KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING, 2024 ("kqueue already closing")); 2025 kq->kq_state |= KQ_CLOSING; 2026 if (kq->kq_refcnt > 1) 2027 msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0); 2028 2029 KASSERT(kq->kq_refcnt == 1, ("other refs are out there!")); 2030 2031 KASSERT(knlist_empty(&kq->kq_sel.si_note), 2032 ("kqueue's knlist not empty")); 2033 2034 for (i = 0; i < kq->kq_knlistsize; i++) { 2035 while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) { 2036 if (kn_in_flux(kn)) { 2037 kq->kq_state |= KQ_FLUXWAIT; 2038 msleep(kq, &kq->kq_lock, PSOCK, "kqclo1", 0); 2039 continue; 2040 } 2041 kn_enter_flux(kn); 2042 KQ_UNLOCK(kq); 2043 knote_drop(kn, td); 2044 KQ_LOCK(kq); 2045 } 2046 } 2047 if (kq->kq_knhashmask != 0) { 2048 for (i = 0; i <= kq->kq_knhashmask; i++) { 2049 while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) { 2050 if (kn_in_flux(kn)) { 2051 kq->kq_state |= KQ_FLUXWAIT; 2052 msleep(kq, &kq->kq_lock, PSOCK, 2053 "kqclo2", 0); 2054 continue; 2055 } 2056 kn_enter_flux(kn); 2057 KQ_UNLOCK(kq); 2058 knote_drop(kn, td); 2059 KQ_LOCK(kq); 2060 } 2061 } 2062 } 2063 2064 if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) { 2065 kq->kq_state |= KQ_TASKDRAIN; 2066 msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0); 2067 } 2068 2069 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2070 selwakeuppri(&kq->kq_sel, PSOCK); 2071 if (!SEL_WAITING(&kq->kq_sel)) 2072 kq->kq_state &= ~KQ_SEL; 2073 } 2074 2075 KQ_UNLOCK(kq); 2076 } 2077 2078 static void 2079 kqueue_destroy(struct kqueue *kq) 2080 { 2081 2082 KASSERT(kq->kq_fdp == NULL, 2083 ("kqueue still attached to a file descriptor")); 2084 seldrain(&kq->kq_sel); 2085 knlist_destroy(&kq->kq_sel.si_note); 2086 mtx_destroy(&kq->kq_lock); 2087 2088 if (kq->kq_knhash != NULL) 2089 free(kq->kq_knhash, M_KQUEUE); 2090 if (kq->kq_knlist != NULL) 2091 free(kq->kq_knlist, M_KQUEUE); 2092 2093 funsetown(&kq->kq_sigio); 2094 } 2095 2096 /*ARGSUSED*/ 2097 static int 2098 kqueue_close(struct file *fp, struct thread *td) 2099 { 2100 struct kqueue *kq = fp->f_data; 2101 struct filedesc *fdp; 2102 int error; 2103 int filedesc_unlock; 2104 2105 if ((error = kqueue_acquire(fp, &kq))) 2106 return error; 2107 kqueue_drain(kq, td); 2108 2109 /* 2110 * We could be called due to the knote_drop() doing fdrop(), 2111 * called from kqueue_register(). In this case the global 2112 * lock is owned, and filedesc sx is locked before, to not 2113 * take the sleepable lock after non-sleepable. 2114 */ 2115 fdp = kq->kq_fdp; 2116 kq->kq_fdp = NULL; 2117 if (!sx_xlocked(FILEDESC_LOCK(fdp))) { 2118 FILEDESC_XLOCK(fdp); 2119 filedesc_unlock = 1; 2120 } else 2121 filedesc_unlock = 0; 2122 TAILQ_REMOVE(&fdp->fd_kqlist, kq, kq_list); 2123 if (filedesc_unlock) 2124 FILEDESC_XUNLOCK(fdp); 2125 2126 kqueue_destroy(kq); 2127 chgkqcnt(kq->kq_cred->cr_ruidinfo, -1, 0); 2128 crfree(kq->kq_cred); 2129 free(kq, M_KQUEUE); 2130 fp->f_data = NULL; 2131 2132 return (0); 2133 } 2134 2135 static int 2136 kqueue_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 2137 { 2138 2139 kif->kf_type = KF_TYPE_KQUEUE; 2140 return (0); 2141 } 2142 2143 static void 2144 kqueue_wakeup(struct kqueue *kq) 2145 { 2146 KQ_OWNED(kq); 2147 2148 if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) { 2149 kq->kq_state &= ~KQ_SLEEP; 2150 wakeup(kq); 2151 } 2152 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2153 selwakeuppri(&kq->kq_sel, PSOCK); 2154 if (!SEL_WAITING(&kq->kq_sel)) 2155 kq->kq_state &= ~KQ_SEL; 2156 } 2157 if (!knlist_empty(&kq->kq_sel.si_note)) 2158 kqueue_schedtask(kq); 2159 if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) { 2160 pgsigio(&kq->kq_sigio, SIGIO, 0); 2161 } 2162 } 2163 2164 /* 2165 * Walk down a list of knotes, activating them if their event has triggered. 2166 * 2167 * There is a possibility to optimize in the case of one kq watching another. 2168 * Instead of scheduling a task to wake it up, you could pass enough state 2169 * down the chain to make up the parent kqueue. Make this code functional 2170 * first. 2171 */ 2172 void 2173 knote(struct knlist *list, long hint, int lockflags) 2174 { 2175 struct kqueue *kq; 2176 struct knote *kn, *tkn; 2177 int error; 2178 2179 if (list == NULL) 2180 return; 2181 2182 KNL_ASSERT_LOCK(list, lockflags & KNF_LISTLOCKED); 2183 2184 if ((lockflags & KNF_LISTLOCKED) == 0) 2185 list->kl_lock(list->kl_lockarg); 2186 2187 /* 2188 * If we unlock the list lock (and enter influx), we can 2189 * eliminate the kqueue scheduling, but this will introduce 2190 * four lock/unlock's for each knote to test. Also, marker 2191 * would be needed to keep iteration position, since filters 2192 * or other threads could remove events. 2193 */ 2194 SLIST_FOREACH_SAFE(kn, &list->kl_list, kn_selnext, tkn) { 2195 kq = kn->kn_kq; 2196 KQ_LOCK(kq); 2197 if (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0) { 2198 /* 2199 * Do not process the influx notes, except for 2200 * the influx coming from the kq unlock in the 2201 * kqueue_scan(). In the later case, we do 2202 * not interfere with the scan, since the code 2203 * fragment in kqueue_scan() locks the knlist, 2204 * and cannot proceed until we finished. 2205 */ 2206 KQ_UNLOCK(kq); 2207 } else if ((lockflags & KNF_NOKQLOCK) != 0) { 2208 kn_enter_flux(kn); 2209 KQ_UNLOCK(kq); 2210 error = kn->kn_fop->f_event(kn, hint); 2211 KQ_LOCK(kq); 2212 kn_leave_flux(kn); 2213 if (error) 2214 KNOTE_ACTIVATE(kn, 1); 2215 KQ_UNLOCK_FLUX(kq); 2216 } else { 2217 kn->kn_status |= KN_HASKQLOCK; 2218 if (kn->kn_fop->f_event(kn, hint)) 2219 KNOTE_ACTIVATE(kn, 1); 2220 kn->kn_status &= ~KN_HASKQLOCK; 2221 KQ_UNLOCK(kq); 2222 } 2223 } 2224 if ((lockflags & KNF_LISTLOCKED) == 0) 2225 list->kl_unlock(list->kl_lockarg); 2226 } 2227 2228 /* 2229 * add a knote to a knlist 2230 */ 2231 void 2232 knlist_add(struct knlist *knl, struct knote *kn, int islocked) 2233 { 2234 2235 KNL_ASSERT_LOCK(knl, islocked); 2236 KQ_NOTOWNED(kn->kn_kq); 2237 KASSERT(kn_in_flux(kn), ("knote %p not in flux", kn)); 2238 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2239 ("knote %p was not detached", kn)); 2240 if (!islocked) 2241 knl->kl_lock(knl->kl_lockarg); 2242 SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext); 2243 if (!islocked) 2244 knl->kl_unlock(knl->kl_lockarg); 2245 KQ_LOCK(kn->kn_kq); 2246 kn->kn_knlist = knl; 2247 kn->kn_status &= ~KN_DETACHED; 2248 KQ_UNLOCK(kn->kn_kq); 2249 } 2250 2251 static void 2252 knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked, 2253 int kqislocked) 2254 { 2255 2256 KASSERT(!kqislocked || knlislocked, ("kq locked w/o knl locked")); 2257 KNL_ASSERT_LOCK(knl, knlislocked); 2258 mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED); 2259 KASSERT(kqislocked || kn_in_flux(kn), ("knote %p not in flux", kn)); 2260 KASSERT((kn->kn_status & KN_DETACHED) == 0, 2261 ("knote %p was already detached", kn)); 2262 if (!knlislocked) 2263 knl->kl_lock(knl->kl_lockarg); 2264 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext); 2265 kn->kn_knlist = NULL; 2266 if (!knlislocked) 2267 kn_list_unlock(knl); 2268 if (!kqislocked) 2269 KQ_LOCK(kn->kn_kq); 2270 kn->kn_status |= KN_DETACHED; 2271 if (!kqislocked) 2272 KQ_UNLOCK(kn->kn_kq); 2273 } 2274 2275 /* 2276 * remove knote from the specified knlist 2277 */ 2278 void 2279 knlist_remove(struct knlist *knl, struct knote *kn, int islocked) 2280 { 2281 2282 knlist_remove_kq(knl, kn, islocked, 0); 2283 } 2284 2285 int 2286 knlist_empty(struct knlist *knl) 2287 { 2288 2289 KNL_ASSERT_LOCKED(knl); 2290 return (SLIST_EMPTY(&knl->kl_list)); 2291 } 2292 2293 static struct mtx knlist_lock; 2294 MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects", 2295 MTX_DEF); 2296 static void knlist_mtx_lock(void *arg); 2297 static void knlist_mtx_unlock(void *arg); 2298 2299 static void 2300 knlist_mtx_lock(void *arg) 2301 { 2302 2303 mtx_lock((struct mtx *)arg); 2304 } 2305 2306 static void 2307 knlist_mtx_unlock(void *arg) 2308 { 2309 2310 mtx_unlock((struct mtx *)arg); 2311 } 2312 2313 static void 2314 knlist_mtx_assert_locked(void *arg) 2315 { 2316 2317 mtx_assert((struct mtx *)arg, MA_OWNED); 2318 } 2319 2320 static void 2321 knlist_mtx_assert_unlocked(void *arg) 2322 { 2323 2324 mtx_assert((struct mtx *)arg, MA_NOTOWNED); 2325 } 2326 2327 static void 2328 knlist_rw_rlock(void *arg) 2329 { 2330 2331 rw_rlock((struct rwlock *)arg); 2332 } 2333 2334 static void 2335 knlist_rw_runlock(void *arg) 2336 { 2337 2338 rw_runlock((struct rwlock *)arg); 2339 } 2340 2341 static void 2342 knlist_rw_assert_locked(void *arg) 2343 { 2344 2345 rw_assert((struct rwlock *)arg, RA_LOCKED); 2346 } 2347 2348 static void 2349 knlist_rw_assert_unlocked(void *arg) 2350 { 2351 2352 rw_assert((struct rwlock *)arg, RA_UNLOCKED); 2353 } 2354 2355 void 2356 knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *), 2357 void (*kl_unlock)(void *), 2358 void (*kl_assert_locked)(void *), void (*kl_assert_unlocked)(void *)) 2359 { 2360 2361 if (lock == NULL) 2362 knl->kl_lockarg = &knlist_lock; 2363 else 2364 knl->kl_lockarg = lock; 2365 2366 if (kl_lock == NULL) 2367 knl->kl_lock = knlist_mtx_lock; 2368 else 2369 knl->kl_lock = kl_lock; 2370 if (kl_unlock == NULL) 2371 knl->kl_unlock = knlist_mtx_unlock; 2372 else 2373 knl->kl_unlock = kl_unlock; 2374 if (kl_assert_locked == NULL) 2375 knl->kl_assert_locked = knlist_mtx_assert_locked; 2376 else 2377 knl->kl_assert_locked = kl_assert_locked; 2378 if (kl_assert_unlocked == NULL) 2379 knl->kl_assert_unlocked = knlist_mtx_assert_unlocked; 2380 else 2381 knl->kl_assert_unlocked = kl_assert_unlocked; 2382 2383 knl->kl_autodestroy = 0; 2384 SLIST_INIT(&knl->kl_list); 2385 } 2386 2387 void 2388 knlist_init_mtx(struct knlist *knl, struct mtx *lock) 2389 { 2390 2391 knlist_init(knl, lock, NULL, NULL, NULL, NULL); 2392 } 2393 2394 struct knlist * 2395 knlist_alloc(struct mtx *lock) 2396 { 2397 struct knlist *knl; 2398 2399 knl = malloc(sizeof(struct knlist), M_KQUEUE, M_WAITOK); 2400 knlist_init_mtx(knl, lock); 2401 return (knl); 2402 } 2403 2404 void 2405 knlist_init_rw_reader(struct knlist *knl, struct rwlock *lock) 2406 { 2407 2408 knlist_init(knl, lock, knlist_rw_rlock, knlist_rw_runlock, 2409 knlist_rw_assert_locked, knlist_rw_assert_unlocked); 2410 } 2411 2412 void 2413 knlist_destroy(struct knlist *knl) 2414 { 2415 2416 KASSERT(KNLIST_EMPTY(knl), 2417 ("destroying knlist %p with knotes on it", knl)); 2418 } 2419 2420 void 2421 knlist_detach(struct knlist *knl) 2422 { 2423 2424 KNL_ASSERT_LOCKED(knl); 2425 knl->kl_autodestroy = 1; 2426 if (knlist_empty(knl)) { 2427 knlist_destroy(knl); 2428 free(knl, M_KQUEUE); 2429 } 2430 } 2431 2432 /* 2433 * Even if we are locked, we may need to drop the lock to allow any influx 2434 * knotes time to "settle". 2435 */ 2436 void 2437 knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn) 2438 { 2439 struct knote *kn, *kn2; 2440 struct kqueue *kq; 2441 2442 KASSERT(!knl->kl_autodestroy, ("cleardel for autodestroy %p", knl)); 2443 if (islocked) 2444 KNL_ASSERT_LOCKED(knl); 2445 else { 2446 KNL_ASSERT_UNLOCKED(knl); 2447 again: /* need to reacquire lock since we have dropped it */ 2448 knl->kl_lock(knl->kl_lockarg); 2449 } 2450 2451 SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) { 2452 kq = kn->kn_kq; 2453 KQ_LOCK(kq); 2454 if (kn_in_flux(kn)) { 2455 KQ_UNLOCK(kq); 2456 continue; 2457 } 2458 knlist_remove_kq(knl, kn, 1, 1); 2459 if (killkn) { 2460 kn_enter_flux(kn); 2461 KQ_UNLOCK(kq); 2462 knote_drop_detached(kn, td); 2463 } else { 2464 /* Make sure cleared knotes disappear soon */ 2465 kn->kn_flags |= EV_EOF | EV_ONESHOT; 2466 KQ_UNLOCK(kq); 2467 } 2468 kq = NULL; 2469 } 2470 2471 if (!SLIST_EMPTY(&knl->kl_list)) { 2472 /* there are still in flux knotes remaining */ 2473 kn = SLIST_FIRST(&knl->kl_list); 2474 kq = kn->kn_kq; 2475 KQ_LOCK(kq); 2476 KASSERT(kn_in_flux(kn), ("knote removed w/o list lock")); 2477 knl->kl_unlock(knl->kl_lockarg); 2478 kq->kq_state |= KQ_FLUXWAIT; 2479 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0); 2480 kq = NULL; 2481 goto again; 2482 } 2483 2484 if (islocked) 2485 KNL_ASSERT_LOCKED(knl); 2486 else { 2487 knl->kl_unlock(knl->kl_lockarg); 2488 KNL_ASSERT_UNLOCKED(knl); 2489 } 2490 } 2491 2492 /* 2493 * Remove all knotes referencing a specified fd must be called with FILEDESC 2494 * lock. This prevents a race where a new fd comes along and occupies the 2495 * entry and we attach a knote to the fd. 2496 */ 2497 void 2498 knote_fdclose(struct thread *td, int fd) 2499 { 2500 struct filedesc *fdp = td->td_proc->p_fd; 2501 struct kqueue *kq; 2502 struct knote *kn; 2503 int influx; 2504 2505 FILEDESC_XLOCK_ASSERT(fdp); 2506 2507 /* 2508 * We shouldn't have to worry about new kevents appearing on fd 2509 * since filedesc is locked. 2510 */ 2511 TAILQ_FOREACH(kq, &fdp->fd_kqlist, kq_list) { 2512 KQ_LOCK(kq); 2513 2514 again: 2515 influx = 0; 2516 while (kq->kq_knlistsize > fd && 2517 (kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) { 2518 if (kn_in_flux(kn)) { 2519 /* someone else might be waiting on our knote */ 2520 if (influx) 2521 wakeup(kq); 2522 kq->kq_state |= KQ_FLUXWAIT; 2523 msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0); 2524 goto again; 2525 } 2526 kn_enter_flux(kn); 2527 KQ_UNLOCK(kq); 2528 influx = 1; 2529 knote_drop(kn, td); 2530 KQ_LOCK(kq); 2531 } 2532 KQ_UNLOCK_FLUX(kq); 2533 } 2534 } 2535 2536 static int 2537 knote_attach(struct knote *kn, struct kqueue *kq) 2538 { 2539 struct klist *list; 2540 2541 KASSERT(kn_in_flux(kn), ("knote %p not marked influx", kn)); 2542 KQ_OWNED(kq); 2543 2544 if (kn->kn_fop->f_isfd) { 2545 if (kn->kn_id >= kq->kq_knlistsize) 2546 return (ENOMEM); 2547 list = &kq->kq_knlist[kn->kn_id]; 2548 } else { 2549 if (kq->kq_knhash == NULL) 2550 return (ENOMEM); 2551 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2552 } 2553 SLIST_INSERT_HEAD(list, kn, kn_link); 2554 return (0); 2555 } 2556 2557 static void 2558 knote_drop(struct knote *kn, struct thread *td) 2559 { 2560 2561 if ((kn->kn_status & KN_DETACHED) == 0) 2562 kn->kn_fop->f_detach(kn); 2563 knote_drop_detached(kn, td); 2564 } 2565 2566 static void 2567 knote_drop_detached(struct knote *kn, struct thread *td) 2568 { 2569 struct kqueue *kq; 2570 struct klist *list; 2571 2572 kq = kn->kn_kq; 2573 2574 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2575 ("knote %p still attached", kn)); 2576 KQ_NOTOWNED(kq); 2577 2578 KQ_LOCK(kq); 2579 KASSERT(kn->kn_influx == 1, 2580 ("knote_drop called on %p with influx %d", kn, kn->kn_influx)); 2581 2582 if (kn->kn_fop->f_isfd) 2583 list = &kq->kq_knlist[kn->kn_id]; 2584 else 2585 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2586 2587 if (!SLIST_EMPTY(list)) 2588 SLIST_REMOVE(list, kn, knote, kn_link); 2589 if (kn->kn_status & KN_QUEUED) 2590 knote_dequeue(kn); 2591 KQ_UNLOCK_FLUX(kq); 2592 2593 if (kn->kn_fop->f_isfd) { 2594 fdrop(kn->kn_fp, td); 2595 kn->kn_fp = NULL; 2596 } 2597 kqueue_fo_release(kn->kn_kevent.filter); 2598 kn->kn_fop = NULL; 2599 knote_free(kn); 2600 } 2601 2602 static void 2603 knote_enqueue(struct knote *kn) 2604 { 2605 struct kqueue *kq = kn->kn_kq; 2606 2607 KQ_OWNED(kn->kn_kq); 2608 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 2609 2610 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2611 kn->kn_status |= KN_QUEUED; 2612 kq->kq_count++; 2613 kqueue_wakeup(kq); 2614 } 2615 2616 static void 2617 knote_dequeue(struct knote *kn) 2618 { 2619 struct kqueue *kq = kn->kn_kq; 2620 2621 KQ_OWNED(kn->kn_kq); 2622 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 2623 2624 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 2625 kn->kn_status &= ~KN_QUEUED; 2626 kq->kq_count--; 2627 } 2628 2629 static void 2630 knote_init(void) 2631 { 2632 2633 knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL, 2634 NULL, NULL, UMA_ALIGN_PTR, 0); 2635 } 2636 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL); 2637 2638 static struct knote * 2639 knote_alloc(int waitok) 2640 { 2641 2642 return (uma_zalloc(knote_zone, (waitok ? M_WAITOK : M_NOWAIT) | 2643 M_ZERO)); 2644 } 2645 2646 static void 2647 knote_free(struct knote *kn) 2648 { 2649 2650 uma_zfree(knote_zone, kn); 2651 } 2652 2653 /* 2654 * Register the kev w/ the kq specified by fd. 2655 */ 2656 int 2657 kqfd_register(int fd, struct kevent *kev, struct thread *td, int waitok) 2658 { 2659 struct kqueue *kq; 2660 struct file *fp; 2661 cap_rights_t rights; 2662 int error; 2663 2664 error = fget(td, fd, cap_rights_init(&rights, CAP_KQUEUE_CHANGE), &fp); 2665 if (error != 0) 2666 return (error); 2667 if ((error = kqueue_acquire(fp, &kq)) != 0) 2668 goto noacquire; 2669 2670 error = kqueue_register(kq, kev, td, waitok); 2671 kqueue_release(kq, 0); 2672 2673 noacquire: 2674 fdrop(fp, td); 2675 return (error); 2676 } 2677