1 /*- 2 * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 #include <sys/param.h> 30 #include <sys/systm.h> 31 #include <sys/kernel.h> 32 #include <sys/lock.h> 33 #include <sys/mutex.h> 34 #include <sys/proc.h> 35 #include <sys/malloc.h> 36 #include <sys/unistd.h> 37 #include <sys/file.h> 38 #include <sys/fcntl.h> 39 #include <sys/selinfo.h> 40 #include <sys/queue.h> 41 #include <sys/event.h> 42 #include <sys/eventvar.h> 43 #include <sys/poll.h> 44 #include <sys/protosw.h> 45 #include <sys/socket.h> 46 #include <sys/socketvar.h> 47 #include <sys/stat.h> 48 #include <sys/sysproto.h> 49 #include <sys/uio.h> 50 51 #include <vm/vm_zone.h> 52 53 static int kqueue_scan(struct file *fp, int maxevents, 54 struct kevent *ulistp, const struct timespec *timeout, 55 struct proc *p); 56 static int kqueue_read(struct file *fp, struct uio *uio, 57 struct ucred *cred, int flags, struct proc *p); 58 static int kqueue_write(struct file *fp, struct uio *uio, 59 struct ucred *cred, int flags, struct proc *p); 60 static int kqueue_ioctl(struct file *fp, u_long com, caddr_t data, 61 struct proc *p); 62 static int kqueue_poll(struct file *fp, int events, struct ucred *cred, 63 struct proc *p); 64 static int kqueue_kqfilter(struct file *fp, struct knote *kn); 65 static int kqueue_stat(struct file *fp, struct stat *st, struct proc *p); 66 static int kqueue_close(struct file *fp, struct proc *p); 67 static void kqueue_wakeup(struct kqueue *kq); 68 69 static struct fileops kqueueops = { 70 kqueue_read, 71 kqueue_write, 72 kqueue_ioctl, 73 kqueue_poll, 74 kqueue_kqfilter, 75 kqueue_stat, 76 kqueue_close 77 }; 78 79 static void knote_attach(struct knote *kn, struct filedesc *fdp); 80 static void knote_drop(struct knote *kn, struct proc *p); 81 static void knote_enqueue(struct knote *kn); 82 static void knote_dequeue(struct knote *kn); 83 static void knote_init(void); 84 static struct knote *knote_alloc(void); 85 static void knote_free(struct knote *kn); 86 87 static void filt_kqdetach(struct knote *kn); 88 static int filt_kqueue(struct knote *kn, long hint); 89 static int filt_procattach(struct knote *kn); 90 static void filt_procdetach(struct knote *kn); 91 static int filt_proc(struct knote *kn, long hint); 92 static int filt_fileattach(struct knote *kn); 93 94 static struct filterops kqread_filtops = 95 { 1, NULL, filt_kqdetach, filt_kqueue }; 96 static struct filterops proc_filtops = 97 { 0, filt_procattach, filt_procdetach, filt_proc }; 98 static struct filterops file_filtops = 99 { 1, filt_fileattach, NULL, NULL }; 100 101 static vm_zone_t knote_zone; 102 103 #define KNOTE_ACTIVATE(kn) do { \ 104 kn->kn_status |= KN_ACTIVE; \ 105 if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 106 knote_enqueue(kn); \ 107 } while(0) 108 109 #define KN_HASHSIZE 64 /* XXX should be tunable */ 110 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 111 112 extern struct filterops aio_filtops; 113 extern struct filterops sig_filtops; 114 115 /* 116 * Table for for all system-defined filters. 117 */ 118 static struct filterops *sysfilt_ops[] = { 119 &file_filtops, /* EVFILT_READ */ 120 &file_filtops, /* EVFILT_WRITE */ 121 &aio_filtops, /* EVFILT_AIO */ 122 &file_filtops, /* EVFILT_VNODE */ 123 &proc_filtops, /* EVFILT_PROC */ 124 &sig_filtops, /* EVFILT_SIGNAL */ 125 }; 126 127 static int 128 filt_fileattach(struct knote *kn) 129 { 130 131 return (fo_kqfilter(kn->kn_fp, kn)); 132 } 133 134 /*ARGSUSED*/ 135 static int 136 kqueue_kqfilter(struct file *fp, struct knote *kn) 137 { 138 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; 139 140 if (kn->kn_filter != EVFILT_READ) 141 return (1); 142 143 kn->kn_fop = &kqread_filtops; 144 SLIST_INSERT_HEAD(&kq->kq_sel.si_note, kn, kn_selnext); 145 return (0); 146 } 147 148 static void 149 filt_kqdetach(struct knote *kn) 150 { 151 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; 152 153 SLIST_REMOVE(&kq->kq_sel.si_note, kn, knote, kn_selnext); 154 } 155 156 /*ARGSUSED*/ 157 static int 158 filt_kqueue(struct knote *kn, long hint) 159 { 160 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; 161 162 kn->kn_data = kq->kq_count; 163 return (kn->kn_data > 0); 164 } 165 166 static int 167 filt_procattach(struct knote *kn) 168 { 169 struct proc *p; 170 int error; 171 172 p = pfind(kn->kn_id); 173 if (p == NULL) 174 return (ESRCH); 175 if ((error = p_can(curproc, p, P_CAN_SEE, NULL))) { 176 PROC_UNLOCK(p); 177 return (error); 178 } 179 180 kn->kn_ptr.p_proc = p; 181 kn->kn_flags |= EV_CLEAR; /* automatically set */ 182 183 /* 184 * internal flag indicating registration done by kernel 185 */ 186 if (kn->kn_flags & EV_FLAG1) { 187 kn->kn_data = kn->kn_sdata; /* ppid */ 188 kn->kn_fflags = NOTE_CHILD; 189 kn->kn_flags &= ~EV_FLAG1; 190 } 191 192 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 193 PROC_UNLOCK(p); 194 195 return (0); 196 } 197 198 /* 199 * The knote may be attached to a different process, which may exit, 200 * leaving nothing for the knote to be attached to. So when the process 201 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 202 * it will be deleted when read out. However, as part of the knote deletion, 203 * this routine is called, so a check is needed to avoid actually performing 204 * a detach, because the original process does not exist any more. 205 */ 206 static void 207 filt_procdetach(struct knote *kn) 208 { 209 struct proc *p = kn->kn_ptr.p_proc; 210 211 if (kn->kn_status & KN_DETACHED) 212 return; 213 214 PROC_LOCK(p); 215 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 216 PROC_UNLOCK(p); 217 } 218 219 static int 220 filt_proc(struct knote *kn, long hint) 221 { 222 u_int event; 223 224 /* 225 * mask off extra data 226 */ 227 event = (u_int)hint & NOTE_PCTRLMASK; 228 229 /* 230 * if the user is interested in this event, record it. 231 */ 232 if (kn->kn_sfflags & event) 233 kn->kn_fflags |= event; 234 235 /* 236 * process is gone, so flag the event as finished. 237 */ 238 if (event == NOTE_EXIT) { 239 kn->kn_status |= KN_DETACHED; 240 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 241 return (1); 242 } 243 244 /* 245 * process forked, and user wants to track the new process, 246 * so attach a new knote to it, and immediately report an 247 * event with the parent's pid. 248 */ 249 if ((event == NOTE_FORK) && (kn->kn_sfflags & NOTE_TRACK)) { 250 struct kevent kev; 251 int error; 252 253 /* 254 * register knote with new process. 255 */ 256 kev.ident = hint & NOTE_PDATAMASK; /* pid */ 257 kev.filter = kn->kn_filter; 258 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 259 kev.fflags = kn->kn_sfflags; 260 kev.data = kn->kn_id; /* parent */ 261 kev.udata = kn->kn_kevent.udata; /* preserve udata */ 262 error = kqueue_register(kn->kn_kq, &kev, NULL); 263 if (error) 264 kn->kn_fflags |= NOTE_TRACKERR; 265 } 266 267 return (kn->kn_fflags != 0); 268 } 269 270 int 271 kqueue(struct proc *p, struct kqueue_args *uap) 272 { 273 struct filedesc *fdp = p->p_fd; 274 struct kqueue *kq; 275 struct file *fp; 276 int fd, error; 277 278 error = falloc(p, &fp, &fd); 279 if (error) 280 return (error); 281 fp->f_flag = FREAD | FWRITE; 282 fp->f_type = DTYPE_KQUEUE; 283 fp->f_ops = &kqueueops; 284 kq = malloc(sizeof(struct kqueue), M_TEMP, M_WAITOK | M_ZERO); 285 TAILQ_INIT(&kq->kq_head); 286 fp->f_data = (caddr_t)kq; 287 p->p_retval[0] = fd; 288 if (fdp->fd_knlistsize < 0) 289 fdp->fd_knlistsize = 0; /* this process has a kq */ 290 kq->kq_fdp = fdp; 291 return (error); 292 } 293 294 #ifndef _SYS_SYSPROTO_H_ 295 struct kevent_args { 296 int fd; 297 const struct kevent *changelist; 298 int nchanges; 299 struct kevent *eventlist; 300 int nevents; 301 const struct timespec *timeout; 302 }; 303 #endif 304 int 305 kevent(struct proc *p, struct kevent_args *uap) 306 { 307 struct filedesc* fdp = p->p_fd; 308 struct kevent *kevp; 309 struct kqueue *kq; 310 struct file *fp = NULL; 311 struct timespec ts; 312 int i, n, nerrors, error; 313 314 if (((u_int)uap->fd) >= fdp->fd_nfiles || 315 (fp = fdp->fd_ofiles[uap->fd]) == NULL || 316 (fp->f_type != DTYPE_KQUEUE)) 317 return (EBADF); 318 319 fhold(fp); 320 321 if (uap->timeout != NULL) { 322 error = copyin(uap->timeout, &ts, sizeof(ts)); 323 if (error) 324 goto done; 325 uap->timeout = &ts; 326 } 327 328 kq = (struct kqueue *)fp->f_data; 329 nerrors = 0; 330 331 while (uap->nchanges > 0) { 332 n = uap->nchanges > KQ_NEVENTS ? KQ_NEVENTS : uap->nchanges; 333 error = copyin(uap->changelist, kq->kq_kev, 334 n * sizeof(struct kevent)); 335 if (error) 336 goto done; 337 for (i = 0; i < n; i++) { 338 kevp = &kq->kq_kev[i]; 339 kevp->flags &= ~EV_SYSFLAGS; 340 error = kqueue_register(kq, kevp, p); 341 if (error) { 342 if (uap->nevents != 0) { 343 kevp->flags = EV_ERROR; 344 kevp->data = error; 345 (void) copyout((caddr_t)kevp, 346 (caddr_t)uap->eventlist, 347 sizeof(*kevp)); 348 uap->eventlist++; 349 uap->nevents--; 350 nerrors++; 351 } else { 352 goto done; 353 } 354 } 355 } 356 uap->nchanges -= n; 357 uap->changelist += n; 358 } 359 if (nerrors) { 360 p->p_retval[0] = nerrors; 361 error = 0; 362 goto done; 363 } 364 365 error = kqueue_scan(fp, uap->nevents, uap->eventlist, uap->timeout, p); 366 done: 367 if (fp != NULL) 368 fdrop(fp, p); 369 return (error); 370 } 371 372 int 373 kqueue_register(struct kqueue *kq, struct kevent *kev, struct proc *p) 374 { 375 struct filedesc *fdp = kq->kq_fdp; 376 struct filterops *fops; 377 struct file *fp = NULL; 378 struct knote *kn = NULL; 379 int s, error = 0; 380 381 if (kev->filter < 0) { 382 if (kev->filter + EVFILT_SYSCOUNT < 0) 383 return (EINVAL); 384 fops = sysfilt_ops[~kev->filter]; /* to 0-base index */ 385 } else { 386 /* 387 * XXX 388 * filter attach routine is responsible for insuring that 389 * the identifier can be attached to it. 390 */ 391 printf("unknown filter: %d\n", kev->filter); 392 return (EINVAL); 393 } 394 395 if (fops->f_isfd) { 396 /* validate descriptor */ 397 if ((u_int)kev->ident >= fdp->fd_nfiles || 398 (fp = fdp->fd_ofiles[kev->ident]) == NULL) 399 return (EBADF); 400 fhold(fp); 401 402 if (kev->ident < fdp->fd_knlistsize) { 403 SLIST_FOREACH(kn, &fdp->fd_knlist[kev->ident], kn_link) 404 if (kq == kn->kn_kq && 405 kev->filter == kn->kn_filter) 406 break; 407 } 408 } else { 409 if (fdp->fd_knhashmask != 0) { 410 struct klist *list; 411 412 list = &fdp->fd_knhash[ 413 KN_HASH((u_long)kev->ident, fdp->fd_knhashmask)]; 414 SLIST_FOREACH(kn, list, kn_link) 415 if (kev->ident == kn->kn_id && 416 kq == kn->kn_kq && 417 kev->filter == kn->kn_filter) 418 break; 419 } 420 } 421 422 if (kn == NULL && ((kev->flags & EV_ADD) == 0)) { 423 error = ENOENT; 424 goto done; 425 } 426 427 /* 428 * kn now contains the matching knote, or NULL if no match 429 */ 430 if (kev->flags & EV_ADD) { 431 432 if (kn == NULL) { 433 kn = knote_alloc(); 434 if (kn == NULL) { 435 error = ENOMEM; 436 goto done; 437 } 438 kn->kn_fp = fp; 439 kn->kn_kq = kq; 440 kn->kn_fop = fops; 441 442 /* 443 * apply reference count to knote structure, and 444 * do not release it at the end of this routine. 445 */ 446 fp = NULL; 447 448 kn->kn_sfflags = kev->fflags; 449 kn->kn_sdata = kev->data; 450 kev->fflags = 0; 451 kev->data = 0; 452 kn->kn_kevent = *kev; 453 454 knote_attach(kn, fdp); 455 if ((error = fops->f_attach(kn)) != 0) { 456 knote_drop(kn, p); 457 goto done; 458 } 459 } else { 460 /* 461 * The user may change some filter values after the 462 * initial EV_ADD, but doing so will not reset any 463 * filter which have already been triggered. 464 */ 465 kn->kn_sfflags = kev->fflags; 466 kn->kn_sdata = kev->data; 467 kn->kn_kevent.udata = kev->udata; 468 } 469 470 s = splhigh(); 471 if (kn->kn_fop->f_event(kn, 0)) 472 KNOTE_ACTIVATE(kn); 473 splx(s); 474 475 } else if (kev->flags & EV_DELETE) { 476 kn->kn_fop->f_detach(kn); 477 knote_drop(kn, p); 478 goto done; 479 } 480 481 if ((kev->flags & EV_DISABLE) && 482 ((kn->kn_status & KN_DISABLED) == 0)) { 483 s = splhigh(); 484 kn->kn_status |= KN_DISABLED; 485 splx(s); 486 } 487 488 if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) { 489 s = splhigh(); 490 kn->kn_status &= ~KN_DISABLED; 491 if ((kn->kn_status & KN_ACTIVE) && 492 ((kn->kn_status & KN_QUEUED) == 0)) 493 knote_enqueue(kn); 494 splx(s); 495 } 496 497 done: 498 if (fp != NULL) 499 fdrop(fp, p); 500 return (error); 501 } 502 503 static int 504 kqueue_scan(struct file *fp, int maxevents, struct kevent *ulistp, 505 const struct timespec *tsp, struct proc *p) 506 { 507 struct kqueue *kq = (struct kqueue *)fp->f_data; 508 struct kevent *kevp; 509 struct timeval atv, rtv, ttv; 510 struct knote *kn, marker; 511 int s, count, timeout, nkev = 0, error = 0; 512 513 count = maxevents; 514 if (count == 0) 515 goto done; 516 517 if (tsp != NULL) { 518 TIMESPEC_TO_TIMEVAL(&atv, tsp); 519 if (itimerfix(&atv)) { 520 error = EINVAL; 521 goto done; 522 } 523 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) 524 timeout = -1; 525 else 526 timeout = atv.tv_sec > 24 * 60 * 60 ? 527 24 * 60 * 60 * hz : tvtohz(&atv); 528 getmicrouptime(&rtv); 529 timevaladd(&atv, &rtv); 530 } else { 531 atv.tv_sec = 0; 532 atv.tv_usec = 0; 533 timeout = 0; 534 } 535 goto start; 536 537 retry: 538 if (atv.tv_sec || atv.tv_usec) { 539 getmicrouptime(&rtv); 540 if (timevalcmp(&rtv, &atv, >=)) 541 goto done; 542 ttv = atv; 543 timevalsub(&ttv, &rtv); 544 timeout = ttv.tv_sec > 24 * 60 * 60 ? 545 24 * 60 * 60 * hz : tvtohz(&ttv); 546 } 547 548 start: 549 kevp = kq->kq_kev; 550 s = splhigh(); 551 if (kq->kq_count == 0) { 552 if (timeout < 0) { 553 error = EWOULDBLOCK; 554 } else { 555 kq->kq_state |= KQ_SLEEP; 556 error = tsleep(kq, PSOCK | PCATCH, "kqread", timeout); 557 } 558 splx(s); 559 if (error == 0) 560 goto retry; 561 /* don't restart after signals... */ 562 if (error == ERESTART) 563 error = EINTR; 564 else if (error == EWOULDBLOCK) 565 error = 0; 566 goto done; 567 } 568 569 TAILQ_INSERT_TAIL(&kq->kq_head, &marker, kn_tqe); 570 while (count) { 571 kn = TAILQ_FIRST(&kq->kq_head); 572 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 573 if (kn == &marker) { 574 splx(s); 575 if (count == maxevents) 576 goto retry; 577 goto done; 578 } 579 if (kn->kn_status & KN_DISABLED) { 580 kn->kn_status &= ~KN_QUEUED; 581 kq->kq_count--; 582 continue; 583 } 584 if ((kn->kn_flags & EV_ONESHOT) == 0 && 585 kn->kn_fop->f_event(kn, 0) == 0) { 586 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 587 kq->kq_count--; 588 continue; 589 } 590 *kevp = kn->kn_kevent; 591 kevp++; 592 nkev++; 593 if (kn->kn_flags & EV_ONESHOT) { 594 kn->kn_status &= ~KN_QUEUED; 595 kq->kq_count--; 596 splx(s); 597 kn->kn_fop->f_detach(kn); 598 knote_drop(kn, p); 599 s = splhigh(); 600 } else if (kn->kn_flags & EV_CLEAR) { 601 kn->kn_data = 0; 602 kn->kn_fflags = 0; 603 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 604 kq->kq_count--; 605 } else { 606 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 607 } 608 count--; 609 if (nkev == KQ_NEVENTS) { 610 splx(s); 611 error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp, 612 sizeof(struct kevent) * nkev); 613 ulistp += nkev; 614 nkev = 0; 615 kevp = kq->kq_kev; 616 s = splhigh(); 617 if (error) 618 break; 619 } 620 } 621 TAILQ_REMOVE(&kq->kq_head, &marker, kn_tqe); 622 splx(s); 623 done: 624 if (nkev != 0) 625 error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp, 626 sizeof(struct kevent) * nkev); 627 p->p_retval[0] = maxevents - count; 628 return (error); 629 } 630 631 /* 632 * XXX 633 * This could be expanded to call kqueue_scan, if desired. 634 */ 635 /*ARGSUSED*/ 636 static int 637 kqueue_read(struct file *fp, struct uio *uio, struct ucred *cred, 638 int flags, struct proc *p) 639 { 640 return (ENXIO); 641 } 642 643 /*ARGSUSED*/ 644 static int 645 kqueue_write(struct file *fp, struct uio *uio, struct ucred *cred, 646 int flags, struct proc *p) 647 { 648 return (ENXIO); 649 } 650 651 /*ARGSUSED*/ 652 static int 653 kqueue_ioctl(struct file *fp, u_long com, caddr_t data, struct proc *p) 654 { 655 return (ENOTTY); 656 } 657 658 /*ARGSUSED*/ 659 static int 660 kqueue_poll(struct file *fp, int events, struct ucred *cred, struct proc *p) 661 { 662 struct kqueue *kq = (struct kqueue *)fp->f_data; 663 int revents = 0; 664 int s = splnet(); 665 666 if (events & (POLLIN | POLLRDNORM)) { 667 if (kq->kq_count) { 668 revents |= events & (POLLIN | POLLRDNORM); 669 } else { 670 selrecord(p, &kq->kq_sel); 671 kq->kq_state |= KQ_SEL; 672 } 673 } 674 splx(s); 675 return (revents); 676 } 677 678 /*ARGSUSED*/ 679 static int 680 kqueue_stat(struct file *fp, struct stat *st, struct proc *p) 681 { 682 struct kqueue *kq = (struct kqueue *)fp->f_data; 683 684 bzero((void *)st, sizeof(*st)); 685 st->st_size = kq->kq_count; 686 st->st_blksize = sizeof(struct kevent); 687 st->st_mode = S_IFIFO; 688 return (0); 689 } 690 691 /*ARGSUSED*/ 692 static int 693 kqueue_close(struct file *fp, struct proc *p) 694 { 695 struct kqueue *kq = (struct kqueue *)fp->f_data; 696 struct filedesc *fdp = p->p_fd; 697 struct knote **knp, *kn, *kn0; 698 int i; 699 700 for (i = 0; i < fdp->fd_knlistsize; i++) { 701 knp = &SLIST_FIRST(&fdp->fd_knlist[i]); 702 kn = *knp; 703 while (kn != NULL) { 704 kn0 = SLIST_NEXT(kn, kn_link); 705 if (kq == kn->kn_kq) { 706 kn->kn_fop->f_detach(kn); 707 fdrop(kn->kn_fp, p); 708 knote_free(kn); 709 *knp = kn0; 710 } else { 711 knp = &SLIST_NEXT(kn, kn_link); 712 } 713 kn = kn0; 714 } 715 } 716 if (fdp->fd_knhashmask != 0) { 717 for (i = 0; i < fdp->fd_knhashmask + 1; i++) { 718 knp = &SLIST_FIRST(&fdp->fd_knhash[i]); 719 kn = *knp; 720 while (kn != NULL) { 721 kn0 = SLIST_NEXT(kn, kn_link); 722 if (kq == kn->kn_kq) { 723 kn->kn_fop->f_detach(kn); 724 /* XXX non-fd release of kn->kn_ptr */ 725 knote_free(kn); 726 *knp = kn0; 727 } else { 728 knp = &SLIST_NEXT(kn, kn_link); 729 } 730 kn = kn0; 731 } 732 } 733 } 734 free(kq, M_TEMP); 735 fp->f_data = NULL; 736 737 return (0); 738 } 739 740 static void 741 kqueue_wakeup(struct kqueue *kq) 742 { 743 744 if (kq->kq_state & KQ_SLEEP) { 745 kq->kq_state &= ~KQ_SLEEP; 746 wakeup(kq); 747 } 748 if (kq->kq_state & KQ_SEL) { 749 kq->kq_state &= ~KQ_SEL; 750 selwakeup(&kq->kq_sel); 751 } 752 KNOTE(&kq->kq_sel.si_note, 0); 753 } 754 755 /* 756 * walk down a list of knotes, activating them if their event has triggered. 757 */ 758 void 759 knote(struct klist *list, long hint) 760 { 761 struct knote *kn; 762 763 SLIST_FOREACH(kn, list, kn_selnext) 764 if (kn->kn_fop->f_event(kn, hint)) 765 KNOTE_ACTIVATE(kn); 766 } 767 768 /* 769 * remove all knotes from a specified klist 770 */ 771 void 772 knote_remove(struct proc *p, struct klist *list) 773 { 774 struct knote *kn; 775 776 while ((kn = SLIST_FIRST(list)) != NULL) { 777 kn->kn_fop->f_detach(kn); 778 knote_drop(kn, p); 779 } 780 } 781 782 /* 783 * remove all knotes referencing a specified fd 784 */ 785 void 786 knote_fdclose(struct proc *p, int fd) 787 { 788 struct filedesc *fdp = p->p_fd; 789 struct klist *list = &fdp->fd_knlist[fd]; 790 791 knote_remove(p, list); 792 } 793 794 static void 795 knote_attach(struct knote *kn, struct filedesc *fdp) 796 { 797 struct klist *list; 798 int size; 799 800 if (! kn->kn_fop->f_isfd) { 801 if (fdp->fd_knhashmask == 0) 802 fdp->fd_knhash = hashinit(KN_HASHSIZE, M_TEMP, 803 &fdp->fd_knhashmask); 804 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; 805 goto done; 806 } 807 808 if (fdp->fd_knlistsize <= kn->kn_id) { 809 size = fdp->fd_knlistsize; 810 while (size <= kn->kn_id) 811 size += KQEXTENT; 812 MALLOC(list, struct klist *, 813 size * sizeof(struct klist *), M_TEMP, M_WAITOK); 814 bcopy((caddr_t)fdp->fd_knlist, (caddr_t)list, 815 fdp->fd_knlistsize * sizeof(struct klist *)); 816 bzero((caddr_t)list + 817 fdp->fd_knlistsize * sizeof(struct klist *), 818 (size - fdp->fd_knlistsize) * sizeof(struct klist *)); 819 if (fdp->fd_knlist != NULL) 820 FREE(fdp->fd_knlist, M_TEMP); 821 fdp->fd_knlistsize = size; 822 fdp->fd_knlist = list; 823 } 824 list = &fdp->fd_knlist[kn->kn_id]; 825 done: 826 SLIST_INSERT_HEAD(list, kn, kn_link); 827 kn->kn_status = 0; 828 } 829 830 /* 831 * should be called at spl == 0, since we don't want to hold spl 832 * while calling fdrop and free. 833 */ 834 static void 835 knote_drop(struct knote *kn, struct proc *p) 836 { 837 struct filedesc *fdp = p->p_fd; 838 struct klist *list; 839 840 if (kn->kn_fop->f_isfd) 841 list = &fdp->fd_knlist[kn->kn_id]; 842 else 843 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; 844 845 SLIST_REMOVE(list, kn, knote, kn_link); 846 if (kn->kn_status & KN_QUEUED) 847 knote_dequeue(kn); 848 if (kn->kn_fop->f_isfd) 849 fdrop(kn->kn_fp, p); 850 knote_free(kn); 851 } 852 853 854 static void 855 knote_enqueue(struct knote *kn) 856 { 857 struct kqueue *kq = kn->kn_kq; 858 int s = splhigh(); 859 860 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 861 862 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 863 kn->kn_status |= KN_QUEUED; 864 kq->kq_count++; 865 splx(s); 866 kqueue_wakeup(kq); 867 } 868 869 static void 870 knote_dequeue(struct knote *kn) 871 { 872 struct kqueue *kq = kn->kn_kq; 873 int s = splhigh(); 874 875 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 876 877 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 878 kn->kn_status &= ~KN_QUEUED; 879 kq->kq_count--; 880 splx(s); 881 } 882 883 static void 884 knote_init(void) 885 { 886 knote_zone = zinit("KNOTE", sizeof(struct knote), 0, 0, 1); 887 } 888 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL) 889 890 static struct knote * 891 knote_alloc(void) 892 { 893 return ((struct knote *)zalloc(knote_zone)); 894 } 895 896 static void 897 knote_free(struct knote *kn) 898 { 899 zfree(knote_zone, kn); 900 } 901