1 /*- 2 * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org> 3 * Copyright 2004 John-Mark Gurney <jmg@FreeBSD.org> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include <sys/param.h> 32 #include <sys/systm.h> 33 #include <sys/kernel.h> 34 #include <sys/lock.h> 35 #include <sys/mutex.h> 36 #include <sys/proc.h> 37 #include <sys/malloc.h> 38 #include <sys/unistd.h> 39 #include <sys/file.h> 40 #include <sys/filedesc.h> 41 #include <sys/filio.h> 42 #include <sys/fcntl.h> 43 #include <sys/kthread.h> 44 #include <sys/selinfo.h> 45 #include <sys/queue.h> 46 #include <sys/event.h> 47 #include <sys/eventvar.h> 48 #include <sys/poll.h> 49 #include <sys/protosw.h> 50 #include <sys/sigio.h> 51 #include <sys/signalvar.h> 52 #include <sys/socket.h> 53 #include <sys/socketvar.h> 54 #include <sys/stat.h> 55 #include <sys/sysctl.h> 56 #include <sys/sysproto.h> 57 #include <sys/syscallsubr.h> 58 #include <sys/taskqueue.h> 59 #include <sys/uio.h> 60 61 #include <vm/uma.h> 62 63 static MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system"); 64 65 /* 66 * This lock is used if multiple kq locks are required. This possibly 67 * should be made into a per proc lock. 68 */ 69 static struct mtx kq_global; 70 MTX_SYSINIT(kq_global, &kq_global, "kqueue order", MTX_DEF); 71 #define KQ_GLOBAL_LOCK(lck, haslck) do { \ 72 if (!haslck) \ 73 mtx_lock(lck); \ 74 haslck = 1; \ 75 } while (0) 76 #define KQ_GLOBAL_UNLOCK(lck, haslck) do { \ 77 if (haslck) \ 78 mtx_unlock(lck); \ 79 haslck = 0; \ 80 } while (0) 81 82 TASKQUEUE_DEFINE_THREAD(kqueue); 83 84 static int kevent_copyout(void *arg, struct kevent *kevp, int count); 85 static int kevent_copyin(void *arg, struct kevent *kevp, int count); 86 static int kqueue_aquire(struct file *fp, struct kqueue **kqp); 87 static void kqueue_release(struct kqueue *kq, int locked); 88 static int kqueue_expand(struct kqueue *kq, struct filterops *fops, 89 uintptr_t ident, int waitok); 90 static void kqueue_task(void *arg, int pending); 91 static int kqueue_scan(struct kqueue *kq, int maxevents, 92 struct kevent_copyops *k_ops, 93 const struct timespec *timeout, 94 struct kevent *keva, struct thread *td); 95 static void kqueue_wakeup(struct kqueue *kq); 96 static struct filterops *kqueue_fo_find(int filt); 97 static void kqueue_fo_release(int filt); 98 99 static fo_rdwr_t kqueue_read; 100 static fo_rdwr_t kqueue_write; 101 static fo_ioctl_t kqueue_ioctl; 102 static fo_poll_t kqueue_poll; 103 static fo_kqfilter_t kqueue_kqfilter; 104 static fo_stat_t kqueue_stat; 105 static fo_close_t kqueue_close; 106 107 static struct fileops kqueueops = { 108 .fo_read = kqueue_read, 109 .fo_write = kqueue_write, 110 .fo_ioctl = kqueue_ioctl, 111 .fo_poll = kqueue_poll, 112 .fo_kqfilter = kqueue_kqfilter, 113 .fo_stat = kqueue_stat, 114 .fo_close = kqueue_close, 115 }; 116 117 static int knote_attach(struct knote *kn, struct kqueue *kq); 118 static void knote_drop(struct knote *kn, struct thread *td); 119 static void knote_enqueue(struct knote *kn); 120 static void knote_dequeue(struct knote *kn); 121 static void knote_init(void); 122 static struct knote *knote_alloc(int waitok); 123 static void knote_free(struct knote *kn); 124 125 static void filt_kqdetach(struct knote *kn); 126 static int filt_kqueue(struct knote *kn, long hint); 127 static int filt_procattach(struct knote *kn); 128 static void filt_procdetach(struct knote *kn); 129 static int filt_proc(struct knote *kn, long hint); 130 static int filt_fileattach(struct knote *kn); 131 static void filt_timerexpire(void *knx); 132 static int filt_timerattach(struct knote *kn); 133 static void filt_timerdetach(struct knote *kn); 134 static int filt_timer(struct knote *kn, long hint); 135 136 static struct filterops file_filtops = 137 { 1, filt_fileattach, NULL, NULL }; 138 static struct filterops kqread_filtops = 139 { 1, NULL, filt_kqdetach, filt_kqueue }; 140 /* XXX - move to kern_proc.c? */ 141 static struct filterops proc_filtops = 142 { 0, filt_procattach, filt_procdetach, filt_proc }; 143 static struct filterops timer_filtops = 144 { 0, filt_timerattach, filt_timerdetach, filt_timer }; 145 146 static uma_zone_t knote_zone; 147 static int kq_ncallouts = 0; 148 static int kq_calloutmax = (4 * 1024); 149 SYSCTL_INT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW, 150 &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue"); 151 152 /* XXX - ensure not KN_INFLUX?? */ 153 #define KNOTE_ACTIVATE(kn, islock) do { \ 154 if ((islock)) \ 155 mtx_assert(&(kn)->kn_kq->kq_lock, MA_OWNED); \ 156 else \ 157 KQ_LOCK((kn)->kn_kq); \ 158 (kn)->kn_status |= KN_ACTIVE; \ 159 if (((kn)->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 160 knote_enqueue((kn)); \ 161 if (!(islock)) \ 162 KQ_UNLOCK((kn)->kn_kq); \ 163 } while(0) 164 #define KQ_LOCK(kq) do { \ 165 mtx_lock(&(kq)->kq_lock); \ 166 } while (0) 167 #define KQ_FLUX_WAKEUP(kq) do { \ 168 if (((kq)->kq_state & KQ_FLUXWAIT) == KQ_FLUXWAIT) { \ 169 (kq)->kq_state &= ~KQ_FLUXWAIT; \ 170 wakeup((kq)); \ 171 } \ 172 } while (0) 173 #define KQ_UNLOCK_FLUX(kq) do { \ 174 KQ_FLUX_WAKEUP(kq); \ 175 mtx_unlock(&(kq)->kq_lock); \ 176 } while (0) 177 #define KQ_UNLOCK(kq) do { \ 178 mtx_unlock(&(kq)->kq_lock); \ 179 } while (0) 180 #define KQ_OWNED(kq) do { \ 181 mtx_assert(&(kq)->kq_lock, MA_OWNED); \ 182 } while (0) 183 #define KQ_NOTOWNED(kq) do { \ 184 mtx_assert(&(kq)->kq_lock, MA_NOTOWNED); \ 185 } while (0) 186 #define KN_LIST_LOCK(kn) do { \ 187 if (kn->kn_knlist != NULL) \ 188 mtx_lock(kn->kn_knlist->kl_lock); \ 189 } while (0) 190 #define KN_LIST_UNLOCK(kn) do { \ 191 if (kn->kn_knlist != NULL) \ 192 mtx_unlock(kn->kn_knlist->kl_lock); \ 193 } while (0) 194 195 #define KN_HASHSIZE 64 /* XXX should be tunable */ 196 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 197 198 static int 199 filt_nullattach(struct knote *kn) 200 { 201 202 return (ENXIO); 203 }; 204 205 struct filterops null_filtops = 206 { 0, filt_nullattach, NULL, NULL }; 207 208 /* XXX - make SYSINIT to add these, and move into respective modules. */ 209 extern struct filterops sig_filtops; 210 extern struct filterops fs_filtops; 211 212 /* 213 * Table for for all system-defined filters. 214 */ 215 static struct mtx filterops_lock; 216 MTX_SYSINIT(kqueue_filterops, &filterops_lock, "protect sysfilt_ops", 217 MTX_DEF); 218 static struct { 219 struct filterops *for_fop; 220 int for_refcnt; 221 } sysfilt_ops[EVFILT_SYSCOUNT] = { 222 { &file_filtops }, /* EVFILT_READ */ 223 { &file_filtops }, /* EVFILT_WRITE */ 224 { &null_filtops }, /* EVFILT_AIO */ 225 { &file_filtops }, /* EVFILT_VNODE */ 226 { &proc_filtops }, /* EVFILT_PROC */ 227 { &sig_filtops }, /* EVFILT_SIGNAL */ 228 { &timer_filtops }, /* EVFILT_TIMER */ 229 { &file_filtops }, /* EVFILT_NETDEV */ 230 { &fs_filtops }, /* EVFILT_FS */ 231 }; 232 233 /* 234 * Simple redirection for all cdevsw style objects to call their fo_kqfilter 235 * method. 236 */ 237 static int 238 filt_fileattach(struct knote *kn) 239 { 240 241 return (fo_kqfilter(kn->kn_fp, kn)); 242 } 243 244 /*ARGSUSED*/ 245 static int 246 kqueue_kqfilter(struct file *fp, struct knote *kn) 247 { 248 struct kqueue *kq = kn->kn_fp->f_data; 249 250 if (kn->kn_filter != EVFILT_READ) 251 return (EINVAL); 252 253 kn->kn_status |= KN_KQUEUE; 254 kn->kn_fop = &kqread_filtops; 255 knlist_add(&kq->kq_sel.si_note, kn, 0); 256 257 return (0); 258 } 259 260 static void 261 filt_kqdetach(struct knote *kn) 262 { 263 struct kqueue *kq = kn->kn_fp->f_data; 264 265 knlist_remove(&kq->kq_sel.si_note, kn, 0); 266 } 267 268 /*ARGSUSED*/ 269 static int 270 filt_kqueue(struct knote *kn, long hint) 271 { 272 struct kqueue *kq = kn->kn_fp->f_data; 273 274 kn->kn_data = kq->kq_count; 275 return (kn->kn_data > 0); 276 } 277 278 /* XXX - move to kern_proc.c? */ 279 static int 280 filt_procattach(struct knote *kn) 281 { 282 struct proc *p; 283 int immediate; 284 int error; 285 286 immediate = 0; 287 p = pfind(kn->kn_id); 288 if (p == NULL && (kn->kn_sfflags & NOTE_EXIT)) { 289 p = zpfind(kn->kn_id); 290 immediate = 1; 291 } else if (p != NULL && (p->p_flag & P_WEXIT)) { 292 immediate = 1; 293 } 294 295 if (p == NULL) 296 return (ESRCH); 297 if ((error = p_cansee(curthread, p))) 298 return (error); 299 300 kn->kn_ptr.p_proc = p; 301 kn->kn_flags |= EV_CLEAR; /* automatically set */ 302 303 /* 304 * internal flag indicating registration done by kernel 305 */ 306 if (kn->kn_flags & EV_FLAG1) { 307 kn->kn_data = kn->kn_sdata; /* ppid */ 308 kn->kn_fflags = NOTE_CHILD; 309 kn->kn_flags &= ~EV_FLAG1; 310 } 311 312 if (immediate == 0) 313 knlist_add(&p->p_klist, kn, 1); 314 315 /* 316 * Immediately activate any exit notes if the target process is a 317 * zombie. This is necessary to handle the case where the target 318 * process, e.g. a child, dies before the kevent is registered. 319 */ 320 if (immediate && filt_proc(kn, NOTE_EXIT)) 321 KNOTE_ACTIVATE(kn, 0); 322 323 PROC_UNLOCK(p); 324 325 return (0); 326 } 327 328 /* 329 * The knote may be attached to a different process, which may exit, 330 * leaving nothing for the knote to be attached to. So when the process 331 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 332 * it will be deleted when read out. However, as part of the knote deletion, 333 * this routine is called, so a check is needed to avoid actually performing 334 * a detach, because the original process does not exist any more. 335 */ 336 /* XXX - move to kern_proc.c? */ 337 static void 338 filt_procdetach(struct knote *kn) 339 { 340 struct proc *p; 341 342 p = kn->kn_ptr.p_proc; 343 knlist_remove(&p->p_klist, kn, 0); 344 kn->kn_ptr.p_proc = NULL; 345 } 346 347 /* XXX - move to kern_proc.c? */ 348 static int 349 filt_proc(struct knote *kn, long hint) 350 { 351 struct proc *p = kn->kn_ptr.p_proc; 352 u_int event; 353 354 /* 355 * mask off extra data 356 */ 357 event = (u_int)hint & NOTE_PCTRLMASK; 358 359 /* 360 * if the user is interested in this event, record it. 361 */ 362 if (kn->kn_sfflags & event) 363 kn->kn_fflags |= event; 364 365 /* 366 * process is gone, so flag the event as finished. 367 */ 368 if (event == NOTE_EXIT) { 369 if (!(kn->kn_status & KN_DETACHED)) 370 knlist_remove_inevent(&p->p_klist, kn); 371 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 372 kn->kn_ptr.p_proc = NULL; 373 return (1); 374 } 375 376 /* 377 * process forked, and user wants to track the new process, 378 * so attach a new knote to it, and immediately report an 379 * event with the parent's pid. 380 */ 381 if ((event == NOTE_FORK) && (kn->kn_sfflags & NOTE_TRACK)) { 382 struct kevent kev; 383 int error; 384 385 /* 386 * register knote with new process. 387 */ 388 kev.ident = hint & NOTE_PDATAMASK; /* pid */ 389 kev.filter = kn->kn_filter; 390 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 391 kev.fflags = kn->kn_sfflags; 392 kev.data = kn->kn_id; /* parent */ 393 kev.udata = kn->kn_kevent.udata; /* preserve udata */ 394 error = kqueue_register(kn->kn_kq, &kev, NULL, 0); 395 if (error) 396 kn->kn_fflags |= NOTE_TRACKERR; 397 } 398 399 return (kn->kn_fflags != 0); 400 } 401 402 static int 403 timertoticks(intptr_t data) 404 { 405 struct timeval tv; 406 int tticks; 407 408 tv.tv_sec = data / 1000; 409 tv.tv_usec = (data % 1000) * 1000; 410 tticks = tvtohz(&tv); 411 412 return tticks; 413 } 414 415 /* XXX - move to kern_timeout.c? */ 416 static void 417 filt_timerexpire(void *knx) 418 { 419 struct knote *kn = knx; 420 struct callout *calloutp; 421 422 kn->kn_data++; 423 KNOTE_ACTIVATE(kn, 0); /* XXX - handle locking */ 424 425 if ((kn->kn_flags & EV_ONESHOT) != EV_ONESHOT) { 426 calloutp = (struct callout *)kn->kn_hook; 427 callout_reset(calloutp, timertoticks(kn->kn_sdata), 428 filt_timerexpire, kn); 429 } 430 } 431 432 /* 433 * data contains amount of time to sleep, in milliseconds 434 */ 435 /* XXX - move to kern_timeout.c? */ 436 static int 437 filt_timerattach(struct knote *kn) 438 { 439 struct callout *calloutp; 440 441 atomic_add_int(&kq_ncallouts, 1); 442 443 if (kq_ncallouts >= kq_calloutmax) { 444 atomic_add_int(&kq_ncallouts, -1); 445 return (ENOMEM); 446 } 447 448 kn->kn_flags |= EV_CLEAR; /* automatically set */ 449 kn->kn_status &= ~KN_DETACHED; /* knlist_add usually sets it */ 450 MALLOC(calloutp, struct callout *, sizeof(*calloutp), 451 M_KQUEUE, M_WAITOK); 452 callout_init(calloutp, CALLOUT_MPSAFE); 453 kn->kn_hook = calloutp; 454 callout_reset(calloutp, timertoticks(kn->kn_sdata), filt_timerexpire, 455 kn); 456 457 return (0); 458 } 459 460 /* XXX - move to kern_timeout.c? */ 461 static void 462 filt_timerdetach(struct knote *kn) 463 { 464 struct callout *calloutp; 465 466 calloutp = (struct callout *)kn->kn_hook; 467 callout_drain(calloutp); 468 FREE(calloutp, M_KQUEUE); 469 atomic_add_int(&kq_ncallouts, -1); 470 kn->kn_status |= KN_DETACHED; /* knlist_remove usually clears it */ 471 } 472 473 /* XXX - move to kern_timeout.c? */ 474 static int 475 filt_timer(struct knote *kn, long hint) 476 { 477 478 return (kn->kn_data != 0); 479 } 480 481 /* 482 * MPSAFE 483 */ 484 int 485 kqueue(struct thread *td, struct kqueue_args *uap) 486 { 487 struct filedesc *fdp; 488 struct kqueue *kq; 489 struct file *fp; 490 int fd, error; 491 492 fdp = td->td_proc->p_fd; 493 error = falloc(td, &fp, &fd); 494 if (error) 495 goto done2; 496 497 /* An extra reference on `nfp' has been held for us by falloc(). */ 498 kq = malloc(sizeof *kq, M_KQUEUE, M_WAITOK | M_ZERO); 499 mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF|MTX_DUPOK); 500 TAILQ_INIT(&kq->kq_head); 501 kq->kq_fdp = fdp; 502 knlist_init(&kq->kq_sel.si_note, &kq->kq_lock); 503 TASK_INIT(&kq->kq_task, 0, kqueue_task, kq); 504 505 FILEDESC_LOCK_FAST(fdp); 506 SLIST_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list); 507 FILEDESC_UNLOCK_FAST(fdp); 508 509 FILE_LOCK(fp); 510 fp->f_flag = FREAD | FWRITE; 511 fp->f_type = DTYPE_KQUEUE; 512 fp->f_ops = &kqueueops; 513 fp->f_data = kq; 514 FILE_UNLOCK(fp); 515 fdrop(fp, td); 516 517 td->td_retval[0] = fd; 518 done2: 519 return (error); 520 } 521 522 #ifndef _SYS_SYSPROTO_H_ 523 struct kevent_args { 524 int fd; 525 const struct kevent *changelist; 526 int nchanges; 527 struct kevent *eventlist; 528 int nevents; 529 const struct timespec *timeout; 530 }; 531 #endif 532 /* 533 * MPSAFE 534 */ 535 int 536 kevent(struct thread *td, struct kevent_args *uap) 537 { 538 struct timespec ts, *tsp; 539 struct kevent_copyops k_ops = { uap, 540 kevent_copyout, 541 kevent_copyin}; 542 int error; 543 544 if (uap->timeout != NULL) { 545 error = copyin(uap->timeout, &ts, sizeof(ts)); 546 if (error) 547 return (error); 548 tsp = &ts; 549 } else 550 tsp = NULL; 551 552 return (kern_kevent(td, uap->fd, uap->nchanges, uap->nevents, 553 &k_ops, tsp)); 554 } 555 556 /* 557 * Copy 'count' items into the destination list pointed to by uap->eventlist. 558 */ 559 static int 560 kevent_copyout(void *arg, struct kevent *kevp, int count) 561 { 562 struct kevent_args *uap; 563 int error; 564 565 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 566 uap = (struct kevent_args *)arg; 567 568 error = copyout(kevp, uap->eventlist, count * sizeof *kevp); 569 if (error == 0) 570 uap->eventlist += count; 571 return (error); 572 } 573 574 /* 575 * Copy 'count' items from the list pointed to by uap->changelist. 576 */ 577 static int 578 kevent_copyin(void *arg, struct kevent *kevp, int count) 579 { 580 struct kevent_args *uap; 581 int error; 582 583 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 584 uap = (struct kevent_args *)arg; 585 586 error = copyin(uap->changelist, kevp, count * sizeof *kevp); 587 if (error == 0) 588 uap->changelist += count; 589 return (error); 590 } 591 592 int 593 kern_kevent(struct thread *td, int fd, int nchanges, int nevents, 594 struct kevent_copyops *k_ops, const struct timespec *timeout) 595 { 596 struct kevent keva[KQ_NEVENTS]; 597 struct kevent *kevp, *changes; 598 struct kqueue *kq; 599 struct file *fp; 600 int i, n, nerrors, error; 601 602 if ((error = fget(td, fd, &fp)) != 0) 603 return (error); 604 if ((error = kqueue_aquire(fp, &kq)) != 0) 605 goto done_norel; 606 607 nerrors = 0; 608 609 while (nchanges > 0) { 610 n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges; 611 error = k_ops->k_copyin(k_ops->arg, keva, n); 612 if (error) 613 goto done; 614 changes = keva; 615 for (i = 0; i < n; i++) { 616 kevp = &changes[i]; 617 kevp->flags &= ~EV_SYSFLAGS; 618 error = kqueue_register(kq, kevp, td, 1); 619 if (error) { 620 if (nevents != 0) { 621 kevp->flags = EV_ERROR; 622 kevp->data = error; 623 (void) k_ops->k_copyout(k_ops->arg, 624 kevp, 1); 625 nevents--; 626 nerrors++; 627 } else { 628 goto done; 629 } 630 } 631 } 632 nchanges -= n; 633 } 634 if (nerrors) { 635 td->td_retval[0] = nerrors; 636 error = 0; 637 goto done; 638 } 639 640 error = kqueue_scan(kq, nevents, k_ops, timeout, keva, td); 641 done: 642 kqueue_release(kq, 0); 643 done_norel: 644 if (fp != NULL) 645 fdrop(fp, td); 646 return (error); 647 } 648 649 int 650 kqueue_add_filteropts(int filt, struct filterops *filtops) 651 { 652 int error; 653 654 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) { 655 printf( 656 "trying to add a filterop that is out of range: %d is beyond %d\n", 657 ~filt, EVFILT_SYSCOUNT); 658 return EINVAL; 659 } 660 mtx_lock(&filterops_lock); 661 if (sysfilt_ops[~filt].for_fop != &null_filtops && 662 sysfilt_ops[~filt].for_fop != NULL) 663 error = EEXIST; 664 else { 665 sysfilt_ops[~filt].for_fop = filtops; 666 sysfilt_ops[~filt].for_refcnt = 0; 667 } 668 mtx_unlock(&filterops_lock); 669 670 return (0); 671 } 672 673 int 674 kqueue_del_filteropts(int filt) 675 { 676 int error; 677 678 error = 0; 679 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 680 return EINVAL; 681 682 mtx_lock(&filterops_lock); 683 if (sysfilt_ops[~filt].for_fop == &null_filtops || 684 sysfilt_ops[~filt].for_fop == NULL) 685 error = EINVAL; 686 else if (sysfilt_ops[~filt].for_refcnt != 0) 687 error = EBUSY; 688 else { 689 sysfilt_ops[~filt].for_fop = &null_filtops; 690 sysfilt_ops[~filt].for_refcnt = 0; 691 } 692 mtx_unlock(&filterops_lock); 693 694 return error; 695 } 696 697 static struct filterops * 698 kqueue_fo_find(int filt) 699 { 700 701 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 702 return NULL; 703 704 mtx_lock(&filterops_lock); 705 sysfilt_ops[~filt].for_refcnt++; 706 if (sysfilt_ops[~filt].for_fop == NULL) 707 sysfilt_ops[~filt].for_fop = &null_filtops; 708 mtx_unlock(&filterops_lock); 709 710 return sysfilt_ops[~filt].for_fop; 711 } 712 713 static void 714 kqueue_fo_release(int filt) 715 { 716 717 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 718 return; 719 720 mtx_lock(&filterops_lock); 721 KASSERT(sysfilt_ops[~filt].for_refcnt > 0, 722 ("filter object refcount not valid on release")); 723 sysfilt_ops[~filt].for_refcnt--; 724 mtx_unlock(&filterops_lock); 725 } 726 727 /* 728 * A ref to kq (obtained via kqueue_aquire) should be held. waitok will 729 * influence if memory allocation should wait. Make sure it is 0 if you 730 * hold any mutexes. 731 */ 732 int 733 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, int waitok) 734 { 735 struct filedesc *fdp; 736 struct filterops *fops; 737 struct file *fp; 738 struct knote *kn, *tkn; 739 int error, filt, event; 740 int haskqglobal; 741 int fd; 742 743 fdp = NULL; 744 fp = NULL; 745 kn = NULL; 746 error = 0; 747 haskqglobal = 0; 748 749 filt = kev->filter; 750 fops = kqueue_fo_find(filt); 751 if (fops == NULL) 752 return EINVAL; 753 754 tkn = knote_alloc(waitok); /* prevent waiting with locks */ 755 756 findkn: 757 if (fops->f_isfd) { 758 KASSERT(td != NULL, ("td is NULL")); 759 fdp = td->td_proc->p_fd; 760 FILEDESC_LOCK(fdp); 761 /* validate descriptor */ 762 fd = kev->ident; 763 if (fd < 0 || fd >= fdp->fd_nfiles || 764 (fp = fdp->fd_ofiles[fd]) == NULL) { 765 FILEDESC_UNLOCK(fdp); 766 error = EBADF; 767 goto done; 768 } 769 fhold(fp); 770 771 if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops, 772 kev->ident, 0) != 0) { 773 /* unlock and try again */ 774 FILEDESC_UNLOCK(fdp); 775 fdrop(fp, td); 776 fp = NULL; 777 error = kqueue_expand(kq, fops, kev->ident, waitok); 778 if (error) 779 goto done; 780 goto findkn; 781 } 782 783 if (fp->f_type == DTYPE_KQUEUE) { 784 /* 785 * if we add some inteligence about what we are doing, 786 * we should be able to support events on ourselves. 787 * We need to know when we are doing this to prevent 788 * getting both the knlist lock and the kq lock since 789 * they are the same thing. 790 */ 791 if (fp->f_data == kq) { 792 FILEDESC_UNLOCK(fdp); 793 error = EINVAL; 794 goto done_noglobal; 795 } 796 797 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 798 } 799 800 FILEDESC_UNLOCK(fdp); 801 KQ_LOCK(kq); 802 if (kev->ident < kq->kq_knlistsize) { 803 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link) 804 if (kev->filter == kn->kn_filter) 805 break; 806 } 807 } else { 808 if ((kev->flags & EV_ADD) == EV_ADD) 809 kqueue_expand(kq, fops, kev->ident, waitok); 810 811 KQ_LOCK(kq); 812 if (kq->kq_knhashmask != 0) { 813 struct klist *list; 814 815 list = &kq->kq_knhash[ 816 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)]; 817 SLIST_FOREACH(kn, list, kn_link) 818 if (kev->ident == kn->kn_id && 819 kev->filter == kn->kn_filter) 820 break; 821 } 822 } 823 824 /* knote is in the process of changing, wait for it to stablize. */ 825 if (kn != NULL && (kn->kn_status & KN_INFLUX) == KN_INFLUX) { 826 if (fp != NULL) { 827 fdrop(fp, td); 828 fp = NULL; 829 } 830 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 831 kq->kq_state |= KQ_FLUXWAIT; 832 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0); 833 goto findkn; 834 } 835 836 if (kn == NULL && ((kev->flags & EV_ADD) == 0)) { 837 KQ_UNLOCK(kq); 838 error = ENOENT; 839 goto done; 840 } 841 842 /* 843 * kn now contains the matching knote, or NULL if no match 844 */ 845 if (kev->flags & EV_ADD) { 846 if (kn == NULL) { 847 kn = tkn; 848 tkn = NULL; 849 if (kn == NULL) { 850 error = ENOMEM; 851 goto done; 852 } 853 kn->kn_fp = fp; 854 kn->kn_kq = kq; 855 kn->kn_fop = fops; 856 /* 857 * apply reference counts to knote structure, and 858 * do not release it at the end of this routine. 859 */ 860 fops = NULL; 861 fp = NULL; 862 863 kn->kn_sfflags = kev->fflags; 864 kn->kn_sdata = kev->data; 865 kev->fflags = 0; 866 kev->data = 0; 867 kn->kn_kevent = *kev; 868 kn->kn_status = KN_INFLUX|KN_DETACHED; 869 870 error = knote_attach(kn, kq); 871 KQ_UNLOCK(kq); 872 if (error != 0) { 873 tkn = kn; 874 goto done; 875 } 876 877 if ((error = kn->kn_fop->f_attach(kn)) != 0) { 878 knote_drop(kn, td); 879 goto done; 880 } 881 KN_LIST_LOCK(kn); 882 } else { 883 /* 884 * The user may change some filter values after the 885 * initial EV_ADD, but doing so will not reset any 886 * filter which has already been triggered. 887 */ 888 kn->kn_status |= KN_INFLUX; 889 KQ_UNLOCK(kq); 890 KN_LIST_LOCK(kn); 891 kn->kn_sfflags = kev->fflags; 892 kn->kn_sdata = kev->data; 893 kn->kn_kevent.udata = kev->udata; 894 } 895 896 /* 897 * We can get here with kn->kn_knlist == NULL. 898 * This can happen when the initial attach event decides that 899 * the event is "completed" already. i.e. filt_procattach 900 * is called on a zombie process. It will call filt_proc 901 * which will remove it from the list, and NULL kn_knlist. 902 */ 903 event = kn->kn_fop->f_event(kn, 0); 904 KN_LIST_UNLOCK(kn); 905 KQ_LOCK(kq); 906 if (event) 907 KNOTE_ACTIVATE(kn, 1); 908 kn->kn_status &= ~KN_INFLUX; 909 } else if (kev->flags & EV_DELETE) { 910 kn->kn_status |= KN_INFLUX; 911 KQ_UNLOCK(kq); 912 if (!(kn->kn_status & KN_DETACHED)) 913 kn->kn_fop->f_detach(kn); 914 knote_drop(kn, td); 915 goto done; 916 } 917 918 if ((kev->flags & EV_DISABLE) && 919 ((kn->kn_status & KN_DISABLED) == 0)) { 920 kn->kn_status |= KN_DISABLED; 921 } 922 923 if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) { 924 kn->kn_status &= ~KN_DISABLED; 925 if ((kn->kn_status & KN_ACTIVE) && 926 ((kn->kn_status & KN_QUEUED) == 0)) 927 knote_enqueue(kn); 928 } 929 KQ_UNLOCK_FLUX(kq); 930 931 done: 932 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 933 done_noglobal: 934 if (fp != NULL) 935 fdrop(fp, td); 936 if (tkn != NULL) 937 knote_free(tkn); 938 if (fops != NULL) 939 kqueue_fo_release(filt); 940 return (error); 941 } 942 943 static int 944 kqueue_aquire(struct file *fp, struct kqueue **kqp) 945 { 946 int error; 947 struct kqueue *kq; 948 949 error = 0; 950 951 FILE_LOCK(fp); 952 do { 953 kq = fp->f_data; 954 if (fp->f_type != DTYPE_KQUEUE || kq == NULL) { 955 error = EBADF; 956 break; 957 } 958 *kqp = kq; 959 KQ_LOCK(kq); 960 if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) { 961 KQ_UNLOCK(kq); 962 error = EBADF; 963 break; 964 } 965 kq->kq_refcnt++; 966 KQ_UNLOCK(kq); 967 } while (0); 968 FILE_UNLOCK(fp); 969 970 return error; 971 } 972 973 static void 974 kqueue_release(struct kqueue *kq, int locked) 975 { 976 if (locked) 977 KQ_OWNED(kq); 978 else 979 KQ_LOCK(kq); 980 kq->kq_refcnt--; 981 if (kq->kq_refcnt == 1) 982 wakeup(&kq->kq_refcnt); 983 if (!locked) 984 KQ_UNLOCK(kq); 985 } 986 987 static void 988 kqueue_schedtask(struct kqueue *kq) 989 { 990 991 KQ_OWNED(kq); 992 KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN), 993 ("scheduling kqueue task while draining")); 994 995 if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) { 996 taskqueue_enqueue(taskqueue_kqueue, &kq->kq_task); 997 kq->kq_state |= KQ_TASKSCHED; 998 } 999 } 1000 1001 /* 1002 * Expand the kq to make sure we have storage for fops/ident pair. 1003 * 1004 * Return 0 on success (or no work necessary), return errno on failure. 1005 * 1006 * Not calling hashinit w/ waitok (proper malloc flag) should be safe. 1007 * If kqueue_register is called from a non-fd context, there usually/should 1008 * be no locks held. 1009 */ 1010 static int 1011 kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident, 1012 int waitok) 1013 { 1014 struct klist *list, *tmp_knhash; 1015 u_long tmp_knhashmask; 1016 int size; 1017 int fd; 1018 int mflag = waitok ? M_WAITOK : M_NOWAIT; 1019 1020 KQ_NOTOWNED(kq); 1021 1022 if (fops->f_isfd) { 1023 fd = ident; 1024 if (kq->kq_knlistsize <= fd) { 1025 size = kq->kq_knlistsize; 1026 while (size <= fd) 1027 size += KQEXTENT; 1028 MALLOC(list, struct klist *, 1029 size * sizeof list, M_KQUEUE, mflag); 1030 if (list == NULL) 1031 return ENOMEM; 1032 KQ_LOCK(kq); 1033 if (kq->kq_knlistsize > fd) { 1034 FREE(list, M_KQUEUE); 1035 list = NULL; 1036 } else { 1037 if (kq->kq_knlist != NULL) { 1038 bcopy(kq->kq_knlist, list, 1039 kq->kq_knlistsize * sizeof list); 1040 FREE(kq->kq_knlist, M_KQUEUE); 1041 kq->kq_knlist = NULL; 1042 } 1043 bzero((caddr_t)list + 1044 kq->kq_knlistsize * sizeof list, 1045 (size - kq->kq_knlistsize) * sizeof list); 1046 kq->kq_knlistsize = size; 1047 kq->kq_knlist = list; 1048 } 1049 KQ_UNLOCK(kq); 1050 } 1051 } else { 1052 if (kq->kq_knhashmask == 0) { 1053 tmp_knhash = hashinit(KN_HASHSIZE, M_KQUEUE, 1054 &tmp_knhashmask); 1055 if (tmp_knhash == NULL) 1056 return ENOMEM; 1057 KQ_LOCK(kq); 1058 if (kq->kq_knhashmask == 0) { 1059 kq->kq_knhash = tmp_knhash; 1060 kq->kq_knhashmask = tmp_knhashmask; 1061 } else { 1062 free(tmp_knhash, M_KQUEUE); 1063 } 1064 KQ_UNLOCK(kq); 1065 } 1066 } 1067 1068 KQ_NOTOWNED(kq); 1069 return 0; 1070 } 1071 1072 static void 1073 kqueue_task(void *arg, int pending) 1074 { 1075 struct kqueue *kq; 1076 int haskqglobal; 1077 1078 haskqglobal = 0; 1079 kq = arg; 1080 1081 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1082 KQ_LOCK(kq); 1083 1084 KNOTE_LOCKED(&kq->kq_sel.si_note, 0); 1085 1086 kq->kq_state &= ~KQ_TASKSCHED; 1087 if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) { 1088 wakeup(&kq->kq_state); 1089 } 1090 KQ_UNLOCK(kq); 1091 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1092 } 1093 1094 /* 1095 * Scan, update kn_data (if not ONESHOT), and copyout triggered events. 1096 * We treat KN_MARKER knotes as if they are INFLUX. 1097 */ 1098 static int 1099 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops, 1100 const struct timespec *tsp, struct kevent *keva, struct thread *td) 1101 { 1102 struct kevent *kevp; 1103 struct timeval atv, rtv, ttv; 1104 struct knote *kn, *marker; 1105 int count, timeout, nkev, error; 1106 int haskqglobal; 1107 1108 count = maxevents; 1109 nkev = 0; 1110 error = 0; 1111 haskqglobal = 0; 1112 1113 if (maxevents == 0) 1114 goto done_nl; 1115 1116 if (tsp != NULL) { 1117 TIMESPEC_TO_TIMEVAL(&atv, tsp); 1118 if (itimerfix(&atv)) { 1119 error = EINVAL; 1120 goto done_nl; 1121 } 1122 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) 1123 timeout = -1; 1124 else 1125 timeout = atv.tv_sec > 24 * 60 * 60 ? 1126 24 * 60 * 60 * hz : tvtohz(&atv); 1127 getmicrouptime(&rtv); 1128 timevaladd(&atv, &rtv); 1129 } else { 1130 atv.tv_sec = 0; 1131 atv.tv_usec = 0; 1132 timeout = 0; 1133 } 1134 marker = knote_alloc(1); 1135 if (marker == NULL) { 1136 error = ENOMEM; 1137 goto done_nl; 1138 } 1139 marker->kn_status = KN_MARKER; 1140 KQ_LOCK(kq); 1141 goto start; 1142 1143 retry: 1144 if (atv.tv_sec || atv.tv_usec) { 1145 getmicrouptime(&rtv); 1146 if (timevalcmp(&rtv, &atv, >=)) 1147 goto done; 1148 ttv = atv; 1149 timevalsub(&ttv, &rtv); 1150 timeout = ttv.tv_sec > 24 * 60 * 60 ? 1151 24 * 60 * 60 * hz : tvtohz(&ttv); 1152 } 1153 1154 start: 1155 kevp = keva; 1156 if (kq->kq_count == 0) { 1157 if (timeout < 0) { 1158 error = EWOULDBLOCK; 1159 } else { 1160 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1161 kq->kq_state |= KQ_SLEEP; 1162 error = msleep(kq, &kq->kq_lock, PSOCK | PCATCH, 1163 "kqread", timeout); 1164 } 1165 if (error == 0) 1166 goto retry; 1167 /* don't restart after signals... */ 1168 if (error == ERESTART) 1169 error = EINTR; 1170 else if (error == EWOULDBLOCK) 1171 error = 0; 1172 goto done; 1173 } 1174 1175 TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); 1176 while (count) { 1177 KQ_OWNED(kq); 1178 kn = TAILQ_FIRST(&kq->kq_head); 1179 1180 if ((kn->kn_status == KN_MARKER && kn != marker) || 1181 (kn->kn_status & KN_INFLUX) == KN_INFLUX) { 1182 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1183 kq->kq_state |= KQ_FLUXWAIT; 1184 error = msleep(kq, &kq->kq_lock, PSOCK, 1185 "kqflxwt", 0); 1186 continue; 1187 } 1188 1189 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1190 if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) { 1191 kn->kn_status &= ~KN_QUEUED; 1192 kq->kq_count--; 1193 continue; 1194 } 1195 if (kn == marker) { 1196 KQ_FLUX_WAKEUP(kq); 1197 if (count == maxevents) 1198 goto retry; 1199 goto done; 1200 } 1201 KASSERT((kn->kn_status & KN_INFLUX) == 0, 1202 ("KN_INFLUX set when not suppose to be")); 1203 1204 if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) { 1205 kn->kn_status &= ~KN_QUEUED; 1206 kn->kn_status |= KN_INFLUX; 1207 kq->kq_count--; 1208 KQ_UNLOCK(kq); 1209 /* 1210 * We don't need to lock the list since we've marked 1211 * it _INFLUX. 1212 */ 1213 *kevp = kn->kn_kevent; 1214 if (!(kn->kn_status & KN_DETACHED)) 1215 kn->kn_fop->f_detach(kn); 1216 knote_drop(kn, td); 1217 KQ_LOCK(kq); 1218 kn = NULL; 1219 } else { 1220 kn->kn_status |= KN_INFLUX; 1221 KQ_UNLOCK(kq); 1222 if ((kn->kn_status & KN_KQUEUE) == KN_KQUEUE) 1223 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1224 KN_LIST_LOCK(kn); 1225 if (kn->kn_fop->f_event(kn, 0) == 0) { 1226 KN_LIST_UNLOCK(kn); 1227 KQ_LOCK(kq); 1228 kn->kn_status &= 1229 ~(KN_QUEUED | KN_ACTIVE | KN_INFLUX); 1230 kq->kq_count--; 1231 continue; 1232 } 1233 *kevp = kn->kn_kevent; 1234 KQ_LOCK(kq); 1235 if (kn->kn_flags & EV_CLEAR) { 1236 kn->kn_data = 0; 1237 kn->kn_fflags = 0; 1238 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 1239 kq->kq_count--; 1240 } else 1241 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 1242 KN_LIST_UNLOCK(kn); 1243 kn->kn_status &= ~(KN_INFLUX); 1244 } 1245 1246 /* we are returning a copy to the user */ 1247 kevp++; 1248 nkev++; 1249 count--; 1250 1251 if (nkev == KQ_NEVENTS) { 1252 KQ_UNLOCK_FLUX(kq); 1253 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1254 nkev = 0; 1255 kevp = keva; 1256 KQ_LOCK(kq); 1257 if (error) 1258 break; 1259 } 1260 } 1261 TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); 1262 done: 1263 KQ_OWNED(kq); 1264 KQ_UNLOCK_FLUX(kq); 1265 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1266 knote_free(marker); 1267 done_nl: 1268 KQ_NOTOWNED(kq); 1269 if (nkev != 0) 1270 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 1271 td->td_retval[0] = maxevents - count; 1272 return (error); 1273 } 1274 1275 /* 1276 * XXX 1277 * This could be expanded to call kqueue_scan, if desired. 1278 */ 1279 /*ARGSUSED*/ 1280 static int 1281 kqueue_read(struct file *fp, struct uio *uio, struct ucred *active_cred, 1282 int flags, struct thread *td) 1283 { 1284 return (ENXIO); 1285 } 1286 1287 /*ARGSUSED*/ 1288 static int 1289 kqueue_write(struct file *fp, struct uio *uio, struct ucred *active_cred, 1290 int flags, struct thread *td) 1291 { 1292 return (ENXIO); 1293 } 1294 1295 /*ARGSUSED*/ 1296 static int 1297 kqueue_ioctl(struct file *fp, u_long cmd, void *data, 1298 struct ucred *active_cred, struct thread *td) 1299 { 1300 /* 1301 * Enabling sigio causes two major problems: 1302 * 1) infinite recursion: 1303 * Synopsys: kevent is being used to track signals and have FIOASYNC 1304 * set. On receipt of a signal this will cause a kqueue to recurse 1305 * into itself over and over. Sending the sigio causes the kqueue 1306 * to become ready, which in turn posts sigio again, forever. 1307 * Solution: this can be solved by setting a flag in the kqueue that 1308 * we have a SIGIO in progress. 1309 * 2) locking problems: 1310 * Synopsys: Kqueue is a leaf subsystem, but adding signalling puts 1311 * us above the proc and pgrp locks. 1312 * Solution: Post a signal using an async mechanism, being sure to 1313 * record a generation count in the delivery so that we do not deliver 1314 * a signal to the wrong process. 1315 * 1316 * Note, these two mechanisms are somewhat mutually exclusive! 1317 */ 1318 #if 0 1319 struct kqueue *kq; 1320 1321 kq = fp->f_data; 1322 switch (cmd) { 1323 case FIOASYNC: 1324 if (*(int *)data) { 1325 kq->kq_state |= KQ_ASYNC; 1326 } else { 1327 kq->kq_state &= ~KQ_ASYNC; 1328 } 1329 return (0); 1330 1331 case FIOSETOWN: 1332 return (fsetown(*(int *)data, &kq->kq_sigio)); 1333 1334 case FIOGETOWN: 1335 *(int *)data = fgetown(&kq->kq_sigio); 1336 return (0); 1337 } 1338 #endif 1339 1340 return (ENOTTY); 1341 } 1342 1343 /*ARGSUSED*/ 1344 static int 1345 kqueue_poll(struct file *fp, int events, struct ucred *active_cred, 1346 struct thread *td) 1347 { 1348 struct kqueue *kq; 1349 int revents = 0; 1350 int error; 1351 1352 if ((error = kqueue_aquire(fp, &kq))) 1353 return POLLERR; 1354 1355 KQ_LOCK(kq); 1356 if (events & (POLLIN | POLLRDNORM)) { 1357 if (kq->kq_count) { 1358 revents |= events & (POLLIN | POLLRDNORM); 1359 } else { 1360 selrecord(td, &kq->kq_sel); 1361 kq->kq_state |= KQ_SEL; 1362 } 1363 } 1364 kqueue_release(kq, 1); 1365 KQ_UNLOCK(kq); 1366 return (revents); 1367 } 1368 1369 /*ARGSUSED*/ 1370 static int 1371 kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred, 1372 struct thread *td) 1373 { 1374 1375 bzero((void *)st, sizeof *st); 1376 /* 1377 * We no longer return kq_count because the unlocked value is useless. 1378 * If you spent all this time getting the count, why not spend your 1379 * syscall better by calling kevent? 1380 * 1381 * XXX - This is needed for libc_r. 1382 */ 1383 st->st_mode = S_IFIFO; 1384 return (0); 1385 } 1386 1387 /*ARGSUSED*/ 1388 static int 1389 kqueue_close(struct file *fp, struct thread *td) 1390 { 1391 struct kqueue *kq = fp->f_data; 1392 struct filedesc *fdp; 1393 struct knote *kn; 1394 int i; 1395 int error; 1396 1397 if ((error = kqueue_aquire(fp, &kq))) 1398 return error; 1399 1400 KQ_LOCK(kq); 1401 1402 KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING, 1403 ("kqueue already closing")); 1404 kq->kq_state |= KQ_CLOSING; 1405 if (kq->kq_refcnt > 1) 1406 msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0); 1407 1408 KASSERT(kq->kq_refcnt == 1, ("other refs are out there!")); 1409 fdp = kq->kq_fdp; 1410 1411 KASSERT(knlist_empty(&kq->kq_sel.si_note), 1412 ("kqueue's knlist not empty")); 1413 1414 for (i = 0; i < kq->kq_knlistsize; i++) { 1415 while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) { 1416 KASSERT((kn->kn_status & KN_INFLUX) == 0, 1417 ("KN_INFLUX set when not suppose to be")); 1418 kn->kn_status |= KN_INFLUX; 1419 KQ_UNLOCK(kq); 1420 if (!(kn->kn_status & KN_DETACHED)) 1421 kn->kn_fop->f_detach(kn); 1422 knote_drop(kn, td); 1423 KQ_LOCK(kq); 1424 } 1425 } 1426 if (kq->kq_knhashmask != 0) { 1427 for (i = 0; i <= kq->kq_knhashmask; i++) { 1428 while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) { 1429 KASSERT((kn->kn_status & KN_INFLUX) == 0, 1430 ("KN_INFLUX set when not suppose to be")); 1431 kn->kn_status |= KN_INFLUX; 1432 KQ_UNLOCK(kq); 1433 if (!(kn->kn_status & KN_DETACHED)) 1434 kn->kn_fop->f_detach(kn); 1435 knote_drop(kn, td); 1436 KQ_LOCK(kq); 1437 } 1438 } 1439 } 1440 1441 if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) { 1442 kq->kq_state |= KQ_TASKDRAIN; 1443 msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0); 1444 } 1445 1446 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 1447 kq->kq_state &= ~KQ_SEL; 1448 selwakeuppri(&kq->kq_sel, PSOCK); 1449 } 1450 1451 KQ_UNLOCK(kq); 1452 1453 FILEDESC_LOCK_FAST(fdp); 1454 SLIST_REMOVE(&fdp->fd_kqlist, kq, kqueue, kq_list); 1455 FILEDESC_UNLOCK_FAST(fdp); 1456 1457 knlist_destroy(&kq->kq_sel.si_note); 1458 mtx_destroy(&kq->kq_lock); 1459 kq->kq_fdp = NULL; 1460 1461 if (kq->kq_knhash != NULL) 1462 free(kq->kq_knhash, M_KQUEUE); 1463 if (kq->kq_knlist != NULL) 1464 free(kq->kq_knlist, M_KQUEUE); 1465 1466 funsetown(&kq->kq_sigio); 1467 free(kq, M_KQUEUE); 1468 fp->f_data = NULL; 1469 1470 return (0); 1471 } 1472 1473 static void 1474 kqueue_wakeup(struct kqueue *kq) 1475 { 1476 KQ_OWNED(kq); 1477 1478 if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) { 1479 kq->kq_state &= ~KQ_SLEEP; 1480 wakeup(kq); 1481 } 1482 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 1483 kq->kq_state &= ~KQ_SEL; 1484 selwakeuppri(&kq->kq_sel, PSOCK); 1485 } 1486 if (!knlist_empty(&kq->kq_sel.si_note)) 1487 kqueue_schedtask(kq); 1488 if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) { 1489 pgsigio(&kq->kq_sigio, SIGIO, 0); 1490 } 1491 } 1492 1493 /* 1494 * Walk down a list of knotes, activating them if their event has triggered. 1495 * 1496 * There is a possibility to optimize in the case of one kq watching another. 1497 * Instead of scheduling a task to wake it up, you could pass enough state 1498 * down the chain to make up the parent kqueue. Make this code functional 1499 * first. 1500 */ 1501 void 1502 knote(struct knlist *list, long hint, int islocked) 1503 { 1504 struct kqueue *kq; 1505 struct knote *kn; 1506 1507 if (list == NULL) 1508 return; 1509 1510 mtx_assert(list->kl_lock, islocked ? MA_OWNED : MA_NOTOWNED); 1511 if (!islocked) 1512 mtx_lock(list->kl_lock); 1513 /* 1514 * If we unlock the list lock (and set KN_INFLUX), we can eliminate 1515 * the kqueue scheduling, but this will introduce four 1516 * lock/unlock's for each knote to test. If we do, continue to use 1517 * SLIST_FOREACH, SLIST_FOREACH_SAFE is not safe in our case, it is 1518 * only safe if you want to remove the current item, which we are 1519 * not doing. 1520 */ 1521 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { 1522 kq = kn->kn_kq; 1523 if ((kn->kn_status & KN_INFLUX) != KN_INFLUX) { 1524 KQ_LOCK(kq); 1525 if ((kn->kn_status & KN_INFLUX) != KN_INFLUX) { 1526 kn->kn_status |= KN_HASKQLOCK; 1527 if (kn->kn_fop->f_event(kn, hint)) 1528 KNOTE_ACTIVATE(kn, 1); 1529 kn->kn_status &= ~KN_HASKQLOCK; 1530 } 1531 KQ_UNLOCK(kq); 1532 } 1533 kq = NULL; 1534 } 1535 if (!islocked) 1536 mtx_unlock(list->kl_lock); 1537 } 1538 1539 /* 1540 * add a knote to a knlist 1541 */ 1542 void 1543 knlist_add(struct knlist *knl, struct knote *kn, int islocked) 1544 { 1545 mtx_assert(knl->kl_lock, islocked ? MA_OWNED : MA_NOTOWNED); 1546 KQ_NOTOWNED(kn->kn_kq); 1547 KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) == 1548 (KN_INFLUX|KN_DETACHED), ("knote not KN_INFLUX and KN_DETACHED")); 1549 if (!islocked) 1550 mtx_lock(knl->kl_lock); 1551 SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext); 1552 if (!islocked) 1553 mtx_unlock(knl->kl_lock); 1554 KQ_LOCK(kn->kn_kq); 1555 kn->kn_knlist = knl; 1556 kn->kn_status &= ~KN_DETACHED; 1557 KQ_UNLOCK(kn->kn_kq); 1558 } 1559 1560 static void 1561 knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked, int kqislocked) 1562 { 1563 KASSERT(!(!!kqislocked && !knlislocked), ("kq locked w/o knl locked")); 1564 mtx_assert(knl->kl_lock, knlislocked ? MA_OWNED : MA_NOTOWNED); 1565 mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED); 1566 if (!kqislocked) 1567 KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) == KN_INFLUX, 1568 ("knlist_remove called w/o knote being KN_INFLUX or already removed")); 1569 if (!knlislocked) 1570 mtx_lock(knl->kl_lock); 1571 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext); 1572 kn->kn_knlist = NULL; 1573 if (!knlislocked) 1574 mtx_unlock(knl->kl_lock); 1575 if (!kqislocked) 1576 KQ_LOCK(kn->kn_kq); 1577 kn->kn_status |= KN_DETACHED; 1578 if (!kqislocked) 1579 KQ_UNLOCK(kn->kn_kq); 1580 } 1581 1582 /* 1583 * remove all knotes from a specified klist 1584 */ 1585 void 1586 knlist_remove(struct knlist *knl, struct knote *kn, int islocked) 1587 { 1588 1589 knlist_remove_kq(knl, kn, islocked, 0); 1590 } 1591 1592 /* 1593 * remove knote from a specified klist while in f_event handler. 1594 */ 1595 void 1596 knlist_remove_inevent(struct knlist *knl, struct knote *kn) 1597 { 1598 1599 knlist_remove_kq(knl, kn, 1, 1600 (kn->kn_status & KN_HASKQLOCK) == KN_HASKQLOCK); 1601 } 1602 1603 int 1604 knlist_empty(struct knlist *knl) 1605 { 1606 1607 mtx_assert(knl->kl_lock, MA_OWNED); 1608 return SLIST_EMPTY(&knl->kl_list); 1609 } 1610 1611 static struct mtx knlist_lock; 1612 MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects", 1613 MTX_DEF); 1614 1615 void 1616 knlist_init(struct knlist *knl, struct mtx *mtx) 1617 { 1618 1619 if (mtx == NULL) 1620 knl->kl_lock = &knlist_lock; 1621 else 1622 knl->kl_lock = mtx; 1623 1624 SLIST_INIT(&knl->kl_list); 1625 } 1626 1627 void 1628 knlist_destroy(struct knlist *knl) 1629 { 1630 1631 #ifdef INVARIANTS 1632 /* 1633 * if we run across this error, we need to find the offending 1634 * driver and have it call knlist_clear. 1635 */ 1636 if (!SLIST_EMPTY(&knl->kl_list)) 1637 printf("WARNING: destroying knlist w/ knotes on it!\n"); 1638 #endif 1639 1640 knl->kl_lock = NULL; 1641 SLIST_INIT(&knl->kl_list); 1642 } 1643 1644 /* 1645 * Even if we are locked, we may need to drop the lock to allow any influx 1646 * knotes time to "settle". 1647 */ 1648 void 1649 knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn) 1650 { 1651 struct knote *kn; 1652 struct kqueue *kq; 1653 1654 if (islocked) 1655 mtx_assert(knl->kl_lock, MA_OWNED); 1656 else { 1657 mtx_assert(knl->kl_lock, MA_NOTOWNED); 1658 again: /* need to reaquire lock since we have dropped it */ 1659 mtx_lock(knl->kl_lock); 1660 } 1661 1662 SLIST_FOREACH(kn, &knl->kl_list, kn_selnext) { 1663 kq = kn->kn_kq; 1664 KQ_LOCK(kq); 1665 if ((kn->kn_status & KN_INFLUX)) { 1666 KQ_UNLOCK(kq); 1667 continue; 1668 } 1669 knlist_remove_kq(knl, kn, 1, 1); 1670 if (killkn) { 1671 kn->kn_status |= KN_INFLUX | KN_DETACHED; 1672 KQ_UNLOCK(kq); 1673 knote_drop(kn, td); 1674 } else { 1675 /* Make sure cleared knotes disappear soon */ 1676 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 1677 KQ_UNLOCK(kq); 1678 } 1679 kq = NULL; 1680 } 1681 1682 if (!SLIST_EMPTY(&knl->kl_list)) { 1683 /* there are still KN_INFLUX remaining */ 1684 kn = SLIST_FIRST(&knl->kl_list); 1685 kq = kn->kn_kq; 1686 KQ_LOCK(kq); 1687 KASSERT(kn->kn_status & KN_INFLUX, 1688 ("knote removed w/o list lock")); 1689 mtx_unlock(knl->kl_lock); 1690 kq->kq_state |= KQ_FLUXWAIT; 1691 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0); 1692 kq = NULL; 1693 goto again; 1694 } 1695 1696 if (islocked) 1697 mtx_assert(knl->kl_lock, MA_OWNED); 1698 else { 1699 mtx_unlock(knl->kl_lock); 1700 mtx_assert(knl->kl_lock, MA_NOTOWNED); 1701 } 1702 } 1703 1704 /* 1705 * remove all knotes referencing a specified fd 1706 * must be called with FILEDESC lock. This prevents a race where a new fd 1707 * comes along and occupies the entry and we attach a knote to the fd. 1708 */ 1709 void 1710 knote_fdclose(struct thread *td, int fd) 1711 { 1712 struct filedesc *fdp = td->td_proc->p_fd; 1713 struct kqueue *kq; 1714 struct knote *kn; 1715 int influx; 1716 1717 FILEDESC_LOCK_ASSERT(fdp, MA_OWNED); 1718 1719 /* 1720 * We shouldn't have to worry about new kevents appearing on fd 1721 * since filedesc is locked. 1722 */ 1723 SLIST_FOREACH(kq, &fdp->fd_kqlist, kq_list) { 1724 KQ_LOCK(kq); 1725 1726 again: 1727 influx = 0; 1728 while (kq->kq_knlistsize > fd && 1729 (kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) { 1730 if (kn->kn_status & KN_INFLUX) { 1731 /* someone else might be waiting on our knote */ 1732 if (influx) 1733 wakeup(kq); 1734 kq->kq_state |= KQ_FLUXWAIT; 1735 msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0); 1736 goto again; 1737 } 1738 kn->kn_status |= KN_INFLUX; 1739 KQ_UNLOCK(kq); 1740 if (!(kn->kn_status & KN_DETACHED)) 1741 kn->kn_fop->f_detach(kn); 1742 knote_drop(kn, td); 1743 influx = 1; 1744 KQ_LOCK(kq); 1745 } 1746 KQ_UNLOCK_FLUX(kq); 1747 } 1748 } 1749 1750 static int 1751 knote_attach(struct knote *kn, struct kqueue *kq) 1752 { 1753 struct klist *list; 1754 1755 KASSERT(kn->kn_status & KN_INFLUX, ("knote not marked INFLUX")); 1756 KQ_OWNED(kq); 1757 1758 if (kn->kn_fop->f_isfd) { 1759 if (kn->kn_id >= kq->kq_knlistsize) 1760 return ENOMEM; 1761 list = &kq->kq_knlist[kn->kn_id]; 1762 } else { 1763 if (kq->kq_knhash == NULL) 1764 return ENOMEM; 1765 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 1766 } 1767 1768 SLIST_INSERT_HEAD(list, kn, kn_link); 1769 1770 return 0; 1771 } 1772 1773 /* 1774 * knote must already have been detatched using the f_detach method. 1775 * no lock need to be held, it is assumed that the KN_INFLUX flag is set 1776 * to prevent other removal. 1777 */ 1778 static void 1779 knote_drop(struct knote *kn, struct thread *td) 1780 { 1781 struct kqueue *kq; 1782 struct klist *list; 1783 1784 kq = kn->kn_kq; 1785 1786 KQ_NOTOWNED(kq); 1787 KASSERT((kn->kn_status & KN_INFLUX) == KN_INFLUX, 1788 ("knote_drop called without KN_INFLUX set in kn_status")); 1789 1790 KQ_LOCK(kq); 1791 if (kn->kn_fop->f_isfd) 1792 list = &kq->kq_knlist[kn->kn_id]; 1793 else 1794 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 1795 1796 SLIST_REMOVE(list, kn, knote, kn_link); 1797 if (kn->kn_status & KN_QUEUED) 1798 knote_dequeue(kn); 1799 KQ_UNLOCK_FLUX(kq); 1800 1801 if (kn->kn_fop->f_isfd) { 1802 fdrop(kn->kn_fp, td); 1803 kn->kn_fp = NULL; 1804 } 1805 kqueue_fo_release(kn->kn_kevent.filter); 1806 kn->kn_fop = NULL; 1807 knote_free(kn); 1808 } 1809 1810 static void 1811 knote_enqueue(struct knote *kn) 1812 { 1813 struct kqueue *kq = kn->kn_kq; 1814 1815 KQ_OWNED(kn->kn_kq); 1816 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 1817 1818 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 1819 kn->kn_status |= KN_QUEUED; 1820 kq->kq_count++; 1821 kqueue_wakeup(kq); 1822 } 1823 1824 static void 1825 knote_dequeue(struct knote *kn) 1826 { 1827 struct kqueue *kq = kn->kn_kq; 1828 1829 KQ_OWNED(kn->kn_kq); 1830 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 1831 1832 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1833 kn->kn_status &= ~KN_QUEUED; 1834 kq->kq_count--; 1835 } 1836 1837 static void 1838 knote_init(void) 1839 { 1840 1841 knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL, 1842 NULL, NULL, UMA_ALIGN_PTR, 0); 1843 } 1844 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL) 1845 1846 static struct knote * 1847 knote_alloc(int waitok) 1848 { 1849 return ((struct knote *)uma_zalloc(knote_zone, 1850 (waitok ? M_WAITOK : M_NOWAIT)|M_ZERO)); 1851 } 1852 1853 static void 1854 knote_free(struct knote *kn) 1855 { 1856 if (kn != NULL) 1857 uma_zfree(knote_zone, kn); 1858 } 1859