1 /* $OpenBSD: kern_event.c,v 1.72 2016/05/13 19:05:07 tedu Exp $ */ 2 3 /*- 4 * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org> 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 * $FreeBSD: src/sys/kern/kern_event.c,v 1.22 2001/02/23 20:32:42 jlemon Exp $ 29 */ 30 31 #include <sys/param.h> 32 #include <sys/systm.h> 33 #include <sys/kernel.h> 34 #include <sys/proc.h> 35 #include <sys/pledge.h> 36 #include <sys/malloc.h> 37 #include <sys/unistd.h> 38 #include <sys/file.h> 39 #include <sys/filedesc.h> 40 #include <sys/fcntl.h> 41 #include <sys/selinfo.h> 42 #include <sys/queue.h> 43 #include <sys/event.h> 44 #include <sys/eventvar.h> 45 #include <sys/ktrace.h> 46 #include <sys/pool.h> 47 #include <sys/protosw.h> 48 #include <sys/socket.h> 49 #include <sys/socketvar.h> 50 #include <sys/stat.h> 51 #include <sys/uio.h> 52 #include <sys/mount.h> 53 #include <sys/poll.h> 54 #include <sys/syscallargs.h> 55 #include <sys/timeout.h> 56 57 int kqueue_scan(struct kqueue *kq, int maxevents, 58 struct kevent *ulistp, const struct timespec *timeout, 59 struct proc *p, int *retval); 60 61 int kqueue_read(struct file *fp, off_t *poff, struct uio *uio, 62 struct ucred *cred); 63 int kqueue_write(struct file *fp, off_t *poff, struct uio *uio, 64 struct ucred *cred); 65 int kqueue_ioctl(struct file *fp, u_long com, caddr_t data, 66 struct proc *p); 67 int kqueue_poll(struct file *fp, int events, struct proc *p); 68 int kqueue_kqfilter(struct file *fp, struct knote *kn); 69 int kqueue_stat(struct file *fp, struct stat *st, struct proc *p); 70 int kqueue_close(struct file *fp, struct proc *p); 71 void kqueue_wakeup(struct kqueue *kq); 72 73 struct fileops kqueueops = { 74 kqueue_read, 75 kqueue_write, 76 kqueue_ioctl, 77 kqueue_poll, 78 kqueue_kqfilter, 79 kqueue_stat, 80 kqueue_close 81 }; 82 83 void knote_attach(struct knote *kn, struct filedesc *fdp); 84 void knote_drop(struct knote *kn, struct proc *p, struct filedesc *fdp); 85 void knote_enqueue(struct knote *kn); 86 void knote_dequeue(struct knote *kn); 87 #define knote_alloc() ((struct knote *)pool_get(&knote_pool, PR_WAITOK)) 88 #define knote_free(kn) pool_put(&knote_pool, (kn)) 89 90 void filt_kqdetach(struct knote *kn); 91 int filt_kqueue(struct knote *kn, long hint); 92 int filt_procattach(struct knote *kn); 93 void filt_procdetach(struct knote *kn); 94 int filt_proc(struct knote *kn, long hint); 95 int filt_fileattach(struct knote *kn); 96 void filt_timerexpire(void *knx); 97 int filt_timerattach(struct knote *kn); 98 void filt_timerdetach(struct knote *kn); 99 int filt_timer(struct knote *kn, long hint); 100 void filt_seltruedetach(struct knote *kn); 101 102 struct filterops kqread_filtops = 103 { 1, NULL, filt_kqdetach, filt_kqueue }; 104 struct filterops proc_filtops = 105 { 0, filt_procattach, filt_procdetach, filt_proc }; 106 struct filterops file_filtops = 107 { 1, filt_fileattach, NULL, NULL }; 108 struct filterops timer_filtops = 109 { 0, filt_timerattach, filt_timerdetach, filt_timer }; 110 111 struct pool knote_pool; 112 struct pool kqueue_pool; 113 int kq_ntimeouts = 0; 114 int kq_timeoutmax = (4 * 1024); 115 116 #define KNOTE_ACTIVATE(kn) do { \ 117 kn->kn_status |= KN_ACTIVE; \ 118 if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 119 knote_enqueue(kn); \ 120 } while(0) 121 122 #define KN_HASHSIZE 64 /* XXX should be tunable */ 123 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 124 125 extern struct filterops sig_filtops; 126 #ifdef notyet 127 extern struct filterops aio_filtops; 128 #endif 129 130 /* 131 * Table for for all system-defined filters. 132 */ 133 struct filterops *sysfilt_ops[] = { 134 &file_filtops, /* EVFILT_READ */ 135 &file_filtops, /* EVFILT_WRITE */ 136 NULL, /*&aio_filtops,*/ /* EVFILT_AIO */ 137 &file_filtops, /* EVFILT_VNODE */ 138 &proc_filtops, /* EVFILT_PROC */ 139 &sig_filtops, /* EVFILT_SIGNAL */ 140 &timer_filtops, /* EVFILT_TIMER */ 141 }; 142 143 void KQREF(struct kqueue *); 144 void KQRELE(struct kqueue *); 145 146 void 147 KQREF(struct kqueue *kq) 148 { 149 ++kq->kq_refs; 150 } 151 152 void 153 KQRELE(struct kqueue *kq) 154 { 155 if (--kq->kq_refs == 0) { 156 pool_put(&kqueue_pool, kq); 157 } 158 } 159 160 void kqueue_init(void); 161 162 void 163 kqueue_init(void) 164 { 165 166 pool_init(&kqueue_pool, sizeof(struct kqueue), 0, 0, PR_WAITOK, 167 "kqueuepl", NULL); 168 pool_init(&knote_pool, sizeof(struct knote), 0, 0, PR_WAITOK, 169 "knotepl", NULL); 170 } 171 172 int 173 filt_fileattach(struct knote *kn) 174 { 175 struct file *fp = kn->kn_fp; 176 177 return fp->f_ops->fo_kqfilter(fp, kn); 178 } 179 180 int 181 kqueue_kqfilter(struct file *fp, struct knote *kn) 182 { 183 struct kqueue *kq = kn->kn_fp->f_data; 184 185 if (kn->kn_filter != EVFILT_READ) 186 return (EINVAL); 187 188 kn->kn_fop = &kqread_filtops; 189 SLIST_INSERT_HEAD(&kq->kq_sel.si_note, kn, kn_selnext); 190 return (0); 191 } 192 193 void 194 filt_kqdetach(struct knote *kn) 195 { 196 struct kqueue *kq = kn->kn_fp->f_data; 197 198 SLIST_REMOVE(&kq->kq_sel.si_note, kn, knote, kn_selnext); 199 } 200 201 int 202 filt_kqueue(struct knote *kn, long hint) 203 { 204 struct kqueue *kq = kn->kn_fp->f_data; 205 206 kn->kn_data = kq->kq_count; 207 return (kn->kn_data > 0); 208 } 209 210 int 211 filt_procattach(struct knote *kn) 212 { 213 struct process *pr; 214 215 if ((curproc->p_p->ps_flags & PS_PLEDGE) && 216 (curproc->p_p->ps_pledge & PLEDGE_PROC) == 0) 217 return pledge_fail(curproc, EPERM, PLEDGE_PROC); 218 219 pr = prfind(kn->kn_id); 220 if (pr == NULL) 221 return (ESRCH); 222 223 /* exiting processes can't be specified */ 224 if (pr->ps_flags & PS_EXITING) 225 return (ESRCH); 226 227 kn->kn_ptr.p_process = pr; 228 kn->kn_flags |= EV_CLEAR; /* automatically set */ 229 230 /* 231 * internal flag indicating registration done by kernel 232 */ 233 if (kn->kn_flags & EV_FLAG1) { 234 kn->kn_data = kn->kn_sdata; /* ppid */ 235 kn->kn_fflags = NOTE_CHILD; 236 kn->kn_flags &= ~EV_FLAG1; 237 } 238 239 /* XXX lock the proc here while adding to the list? */ 240 SLIST_INSERT_HEAD(&pr->ps_klist, kn, kn_selnext); 241 242 return (0); 243 } 244 245 /* 246 * The knote may be attached to a different process, which may exit, 247 * leaving nothing for the knote to be attached to. So when the process 248 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 249 * it will be deleted when read out. However, as part of the knote deletion, 250 * this routine is called, so a check is needed to avoid actually performing 251 * a detach, because the original process does not exist any more. 252 */ 253 void 254 filt_procdetach(struct knote *kn) 255 { 256 struct process *pr = kn->kn_ptr.p_process; 257 258 if (kn->kn_status & KN_DETACHED) 259 return; 260 261 /* XXX locking? this might modify another process. */ 262 SLIST_REMOVE(&pr->ps_klist, kn, knote, kn_selnext); 263 } 264 265 int 266 filt_proc(struct knote *kn, long hint) 267 { 268 u_int event; 269 270 /* 271 * mask off extra data 272 */ 273 event = (u_int)hint & NOTE_PCTRLMASK; 274 275 /* 276 * if the user is interested in this event, record it. 277 */ 278 if (kn->kn_sfflags & event) 279 kn->kn_fflags |= event; 280 281 /* 282 * process is gone, so flag the event as finished and remove it 283 * from the process's klist 284 */ 285 if (event == NOTE_EXIT) { 286 struct process *pr = kn->kn_ptr.p_process; 287 288 kn->kn_status |= KN_DETACHED; 289 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 290 kn->kn_data = pr->ps_mainproc->p_xstat; 291 SLIST_REMOVE(&pr->ps_klist, kn, knote, kn_selnext); 292 return (1); 293 } 294 295 /* 296 * process forked, and user wants to track the new process, 297 * so attach a new knote to it, and immediately report an 298 * event with the parent's pid. 299 */ 300 if ((event == NOTE_FORK) && (kn->kn_sfflags & NOTE_TRACK)) { 301 struct kevent kev; 302 int error; 303 304 /* 305 * register knote with new process. 306 */ 307 kev.ident = hint & NOTE_PDATAMASK; /* pid */ 308 kev.filter = kn->kn_filter; 309 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 310 kev.fflags = kn->kn_sfflags; 311 kev.data = kn->kn_id; /* parent */ 312 kev.udata = kn->kn_kevent.udata; /* preserve udata */ 313 error = kqueue_register(kn->kn_kq, &kev, NULL); 314 if (error) 315 kn->kn_fflags |= NOTE_TRACKERR; 316 } 317 318 return (kn->kn_fflags != 0); 319 } 320 321 static void 322 filt_timer_timeout_add(struct knote *kn) 323 { 324 struct timeval tv; 325 int tticks; 326 327 tv.tv_sec = kn->kn_sdata / 1000; 328 tv.tv_usec = (kn->kn_sdata % 1000) * 1000; 329 tticks = tvtohz(&tv); 330 timeout_add(kn->kn_hook, tticks ? tticks : 1); 331 } 332 333 void 334 filt_timerexpire(void *knx) 335 { 336 struct knote *kn = knx; 337 338 kn->kn_data++; 339 KNOTE_ACTIVATE(kn); 340 341 if ((kn->kn_flags & EV_ONESHOT) == 0) 342 filt_timer_timeout_add(kn); 343 } 344 345 346 /* 347 * data contains amount of time to sleep, in milliseconds 348 */ 349 int 350 filt_timerattach(struct knote *kn) 351 { 352 struct timeout *to; 353 354 if (kq_ntimeouts > kq_timeoutmax) 355 return (ENOMEM); 356 kq_ntimeouts++; 357 358 kn->kn_flags |= EV_CLEAR; /* automatically set */ 359 to = malloc(sizeof(*to), M_KEVENT, M_WAITOK); 360 timeout_set(to, filt_timerexpire, kn); 361 kn->kn_hook = to; 362 filt_timer_timeout_add(kn); 363 364 return (0); 365 } 366 367 void 368 filt_timerdetach(struct knote *kn) 369 { 370 struct timeout *to; 371 372 to = (struct timeout *)kn->kn_hook; 373 timeout_del(to); 374 free(to, M_KEVENT, sizeof(*to)); 375 kq_ntimeouts--; 376 } 377 378 int 379 filt_timer(struct knote *kn, long hint) 380 { 381 return (kn->kn_data != 0); 382 } 383 384 385 /* 386 * filt_seltrue: 387 * 388 * This filter "event" routine simulates seltrue(). 389 */ 390 int 391 filt_seltrue(struct knote *kn, long hint) 392 { 393 394 /* 395 * We don't know how much data can be read/written, 396 * but we know that it *can* be. This is about as 397 * good as select/poll does as well. 398 */ 399 kn->kn_data = 0; 400 return (1); 401 } 402 403 /* 404 * This provides full kqfilter entry for device switch tables, which 405 * has same effect as filter using filt_seltrue() as filter method. 406 */ 407 void 408 filt_seltruedetach(struct knote *kn) 409 { 410 /* Nothing to do */ 411 } 412 413 const struct filterops seltrue_filtops = 414 { 1, NULL, filt_seltruedetach, filt_seltrue }; 415 416 int 417 seltrue_kqfilter(dev_t dev, struct knote *kn) 418 { 419 switch (kn->kn_filter) { 420 case EVFILT_READ: 421 case EVFILT_WRITE: 422 kn->kn_fop = &seltrue_filtops; 423 break; 424 default: 425 return (EINVAL); 426 } 427 428 /* Nothing more to do */ 429 return (0); 430 } 431 432 int 433 sys_kqueue(struct proc *p, void *v, register_t *retval) 434 { 435 struct filedesc *fdp = p->p_fd; 436 struct kqueue *kq; 437 struct file *fp; 438 int fd, error; 439 440 fdplock(fdp); 441 error = falloc(p, &fp, &fd); 442 fdpunlock(fdp); 443 if (error) 444 return (error); 445 fp->f_flag = FREAD | FWRITE; 446 fp->f_type = DTYPE_KQUEUE; 447 fp->f_ops = &kqueueops; 448 kq = pool_get(&kqueue_pool, PR_WAITOK|PR_ZERO); 449 TAILQ_INIT(&kq->kq_head); 450 fp->f_data = kq; 451 KQREF(kq); 452 *retval = fd; 453 if (fdp->fd_knlistsize < 0) 454 fdp->fd_knlistsize = 0; /* this process has a kq */ 455 kq->kq_fdp = fdp; 456 FILE_SET_MATURE(fp, p); 457 return (0); 458 } 459 460 int 461 sys_kevent(struct proc *p, void *v, register_t *retval) 462 { 463 struct filedesc* fdp = p->p_fd; 464 struct sys_kevent_args /* { 465 syscallarg(int) fd; 466 syscallarg(const struct kevent *) changelist; 467 syscallarg(int) nchanges; 468 syscallarg(struct kevent *) eventlist; 469 syscallarg(int) nevents; 470 syscallarg(const struct timespec *) timeout; 471 } */ *uap = v; 472 struct kevent *kevp; 473 struct kqueue *kq; 474 struct file *fp; 475 struct timespec ts; 476 int i, n, nerrors, error; 477 478 if ((fp = fd_getfile(fdp, SCARG(uap, fd))) == NULL || 479 (fp->f_type != DTYPE_KQUEUE)) 480 return (EBADF); 481 482 FREF(fp); 483 484 if (SCARG(uap, timeout) != NULL) { 485 error = copyin(SCARG(uap, timeout), &ts, sizeof(ts)); 486 if (error) 487 goto done; 488 #ifdef KTRACE 489 if (KTRPOINT(p, KTR_STRUCT)) 490 ktrreltimespec(p, &ts); 491 #endif 492 SCARG(uap, timeout) = &ts; 493 } 494 495 kq = fp->f_data; 496 nerrors = 0; 497 498 while (SCARG(uap, nchanges) > 0) { 499 n = SCARG(uap, nchanges) > KQ_NEVENTS ? 500 KQ_NEVENTS : SCARG(uap, nchanges); 501 error = copyin(SCARG(uap, changelist), kq->kq_kev, 502 n * sizeof(struct kevent)); 503 if (error) 504 goto done; 505 #ifdef KTRACE 506 if (KTRPOINT(p, KTR_STRUCT)) 507 ktrevent(p, kq->kq_kev, n); 508 #endif 509 for (i = 0; i < n; i++) { 510 kevp = &kq->kq_kev[i]; 511 kevp->flags &= ~EV_SYSFLAGS; 512 error = kqueue_register(kq, kevp, p); 513 if (error) { 514 if (SCARG(uap, nevents) != 0) { 515 kevp->flags = EV_ERROR; 516 kevp->data = error; 517 copyout(kevp, SCARG(uap, eventlist), 518 sizeof(*kevp)); 519 SCARG(uap, eventlist)++; 520 SCARG(uap, nevents)--; 521 nerrors++; 522 } else { 523 goto done; 524 } 525 } 526 } 527 SCARG(uap, nchanges) -= n; 528 SCARG(uap, changelist) += n; 529 } 530 if (nerrors) { 531 *retval = nerrors; 532 error = 0; 533 goto done; 534 } 535 536 KQREF(kq); 537 FRELE(fp, p); 538 error = kqueue_scan(kq, SCARG(uap, nevents), SCARG(uap, eventlist), 539 SCARG(uap, timeout), p, &n); 540 KQRELE(kq); 541 *retval = n; 542 return (error); 543 544 done: 545 FRELE(fp, p); 546 return (error); 547 } 548 549 int 550 kqueue_register(struct kqueue *kq, struct kevent *kev, struct proc *p) 551 { 552 struct filedesc *fdp = kq->kq_fdp; 553 struct filterops *fops = NULL; 554 struct file *fp = NULL; 555 struct knote *kn = NULL; 556 int s, error = 0; 557 558 if (kev->filter < 0) { 559 if (kev->filter + EVFILT_SYSCOUNT < 0) 560 return (EINVAL); 561 fops = sysfilt_ops[~kev->filter]; /* to 0-base index */ 562 } 563 564 if (fops == NULL) { 565 /* 566 * XXX 567 * filter attach routine is responsible for ensuring that 568 * the identifier can be attached to it. 569 */ 570 return (EINVAL); 571 } 572 573 if (fops->f_isfd) { 574 /* validate descriptor */ 575 if ((fp = fd_getfile(fdp, kev->ident)) == NULL) 576 return (EBADF); 577 FREF(fp); 578 579 if (kev->ident < fdp->fd_knlistsize) { 580 SLIST_FOREACH(kn, &fdp->fd_knlist[kev->ident], kn_link) { 581 if (kq == kn->kn_kq && 582 kev->filter == kn->kn_filter) 583 break; 584 } 585 } 586 } else { 587 if (fdp->fd_knhashmask != 0) { 588 struct klist *list; 589 590 list = &fdp->fd_knhash[ 591 KN_HASH((u_long)kev->ident, fdp->fd_knhashmask)]; 592 SLIST_FOREACH(kn, list, kn_link) { 593 if (kev->ident == kn->kn_id && 594 kq == kn->kn_kq && 595 kev->filter == kn->kn_filter) 596 break; 597 } 598 } 599 } 600 601 if (kn == NULL && ((kev->flags & EV_ADD) == 0)) { 602 error = ENOENT; 603 goto done; 604 } 605 606 /* 607 * kn now contains the matching knote, or NULL if no match 608 */ 609 if (kev->flags & EV_ADD) { 610 611 if (kn == NULL) { 612 kn = knote_alloc(); 613 if (kn == NULL) { 614 error = ENOMEM; 615 goto done; 616 } 617 kn->kn_fp = fp; 618 kn->kn_kq = kq; 619 kn->kn_fop = fops; 620 621 /* 622 * apply reference count to knote structure, and 623 * do not release it at the end of this routine. 624 */ 625 fp = NULL; 626 627 kn->kn_sfflags = kev->fflags; 628 kn->kn_sdata = kev->data; 629 kev->fflags = 0; 630 kev->data = 0; 631 kn->kn_kevent = *kev; 632 633 knote_attach(kn, fdp); 634 if ((error = fops->f_attach(kn)) != 0) { 635 knote_drop(kn, p, fdp); 636 goto done; 637 } 638 } else { 639 /* 640 * The user may change some filter values after the 641 * initial EV_ADD, but doing so will not reset any 642 * filters which have already been triggered. 643 */ 644 kn->kn_sfflags = kev->fflags; 645 kn->kn_sdata = kev->data; 646 kn->kn_kevent.udata = kev->udata; 647 } 648 649 s = splhigh(); 650 if (kn->kn_fop->f_event(kn, 0)) 651 KNOTE_ACTIVATE(kn); 652 splx(s); 653 654 } else if (kev->flags & EV_DELETE) { 655 kn->kn_fop->f_detach(kn); 656 knote_drop(kn, p, p->p_fd); 657 goto done; 658 } 659 660 if ((kev->flags & EV_DISABLE) && 661 ((kn->kn_status & KN_DISABLED) == 0)) { 662 s = splhigh(); 663 kn->kn_status |= KN_DISABLED; 664 splx(s); 665 } 666 667 if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) { 668 s = splhigh(); 669 kn->kn_status &= ~KN_DISABLED; 670 if ((kn->kn_status & KN_ACTIVE) && 671 ((kn->kn_status & KN_QUEUED) == 0)) 672 knote_enqueue(kn); 673 splx(s); 674 } 675 676 done: 677 if (fp != NULL) 678 FRELE(fp, p); 679 return (error); 680 } 681 682 int 683 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent *ulistp, 684 const struct timespec *tsp, struct proc *p, int *retval) 685 { 686 struct kevent *kevp; 687 struct timeval atv, rtv, ttv; 688 struct knote *kn, marker; 689 int s, count, timeout, nkev = 0, error = 0; 690 691 count = maxevents; 692 if (count == 0) 693 goto done; 694 695 if (tsp != NULL) { 696 TIMESPEC_TO_TIMEVAL(&atv, tsp); 697 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) { 698 /* No timeout, just poll */ 699 timeout = -1; 700 goto start; 701 } 702 if (itimerfix(&atv)) { 703 error = EINVAL; 704 goto done; 705 } 706 707 timeout = atv.tv_sec > 24 * 60 * 60 ? 708 24 * 60 * 60 * hz : tvtohz(&atv); 709 710 getmicrouptime(&rtv); 711 timeradd(&atv, &rtv, &atv); 712 } else { 713 atv.tv_sec = 0; 714 atv.tv_usec = 0; 715 timeout = 0; 716 } 717 goto start; 718 719 retry: 720 if (atv.tv_sec || atv.tv_usec) { 721 getmicrouptime(&rtv); 722 if (timercmp(&rtv, &atv, >=)) 723 goto done; 724 ttv = atv; 725 timersub(&ttv, &rtv, &ttv); 726 timeout = ttv.tv_sec > 24 * 60 * 60 ? 727 24 * 60 * 60 * hz : tvtohz(&ttv); 728 } 729 730 start: 731 if (kq->kq_state & KQ_DYING) { 732 error = EBADF; 733 goto done; 734 } 735 736 kevp = kq->kq_kev; 737 s = splhigh(); 738 if (kq->kq_count == 0) { 739 if (timeout < 0) { 740 error = EWOULDBLOCK; 741 } else { 742 kq->kq_state |= KQ_SLEEP; 743 error = tsleep(kq, PSOCK | PCATCH, "kqread", timeout); 744 } 745 splx(s); 746 if (error == 0) 747 goto retry; 748 /* don't restart after signals... */ 749 if (error == ERESTART) 750 error = EINTR; 751 else if (error == EWOULDBLOCK) 752 error = 0; 753 goto done; 754 } 755 756 TAILQ_INSERT_TAIL(&kq->kq_head, &marker, kn_tqe); 757 while (count) { 758 kn = TAILQ_FIRST(&kq->kq_head); 759 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 760 if (kn == &marker) { 761 splx(s); 762 if (count == maxevents) 763 goto retry; 764 goto done; 765 } 766 if (kn->kn_status & KN_DISABLED) { 767 kn->kn_status &= ~KN_QUEUED; 768 kq->kq_count--; 769 continue; 770 } 771 if ((kn->kn_flags & EV_ONESHOT) == 0 && 772 kn->kn_fop->f_event(kn, 0) == 0) { 773 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 774 kq->kq_count--; 775 continue; 776 } 777 *kevp = kn->kn_kevent; 778 kevp++; 779 nkev++; 780 if (kn->kn_flags & EV_ONESHOT) { 781 kn->kn_status &= ~KN_QUEUED; 782 kq->kq_count--; 783 splx(s); 784 kn->kn_fop->f_detach(kn); 785 knote_drop(kn, p, p->p_fd); 786 s = splhigh(); 787 } else if (kn->kn_flags & EV_CLEAR) { 788 kn->kn_data = 0; 789 kn->kn_fflags = 0; 790 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 791 kq->kq_count--; 792 } else { 793 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 794 } 795 count--; 796 if (nkev == KQ_NEVENTS) { 797 splx(s); 798 #ifdef KTRACE 799 if (KTRPOINT(p, KTR_STRUCT)) 800 ktrevent(p, kq->kq_kev, nkev); 801 #endif 802 error = copyout(kq->kq_kev, ulistp, 803 sizeof(struct kevent) * nkev); 804 ulistp += nkev; 805 nkev = 0; 806 kevp = kq->kq_kev; 807 s = splhigh(); 808 if (error) 809 break; 810 } 811 } 812 TAILQ_REMOVE(&kq->kq_head, &marker, kn_tqe); 813 splx(s); 814 done: 815 if (nkev != 0) { 816 #ifdef KTRACE 817 if (KTRPOINT(p, KTR_STRUCT)) 818 ktrevent(p, kq->kq_kev, nkev); 819 #endif 820 error = copyout(kq->kq_kev, ulistp, 821 sizeof(struct kevent) * nkev); 822 } 823 *retval = maxevents - count; 824 return (error); 825 } 826 827 /* 828 * XXX 829 * This could be expanded to call kqueue_scan, if desired. 830 */ 831 int 832 kqueue_read(struct file *fp, off_t *poff, struct uio *uio, struct ucred *cred) 833 { 834 return (ENXIO); 835 } 836 837 int 838 kqueue_write(struct file *fp, off_t *poff, struct uio *uio, struct ucred *cred) 839 840 { 841 return (ENXIO); 842 } 843 844 int 845 kqueue_ioctl(struct file *fp, u_long com, caddr_t data, struct proc *p) 846 { 847 return (ENOTTY); 848 } 849 850 int 851 kqueue_poll(struct file *fp, int events, struct proc *p) 852 { 853 struct kqueue *kq = (struct kqueue *)fp->f_data; 854 int revents = 0; 855 int s = splhigh(); 856 857 if (events & (POLLIN | POLLRDNORM)) { 858 if (kq->kq_count) { 859 revents |= events & (POLLIN | POLLRDNORM); 860 } else { 861 selrecord(p, &kq->kq_sel); 862 kq->kq_state |= KQ_SEL; 863 } 864 } 865 splx(s); 866 return (revents); 867 } 868 869 int 870 kqueue_stat(struct file *fp, struct stat *st, struct proc *p) 871 { 872 struct kqueue *kq = fp->f_data; 873 874 memset(st, 0, sizeof(*st)); 875 st->st_size = kq->kq_count; 876 st->st_blksize = sizeof(struct kevent); 877 st->st_mode = S_IFIFO; 878 return (0); 879 } 880 881 int 882 kqueue_close(struct file *fp, struct proc *p) 883 { 884 struct kqueue *kq = fp->f_data; 885 struct filedesc *fdp = p->p_fd; 886 struct knote **knp, *kn, *kn0; 887 int i; 888 889 for (i = 0; i < fdp->fd_knlistsize; i++) { 890 knp = &SLIST_FIRST(&fdp->fd_knlist[i]); 891 kn = *knp; 892 while (kn != NULL) { 893 kn0 = SLIST_NEXT(kn, kn_link); 894 if (kq == kn->kn_kq) { 895 kn->kn_fop->f_detach(kn); 896 FRELE(kn->kn_fp, p); 897 knote_free(kn); 898 *knp = kn0; 899 } else { 900 knp = &SLIST_NEXT(kn, kn_link); 901 } 902 kn = kn0; 903 } 904 } 905 if (fdp->fd_knhashmask != 0) { 906 for (i = 0; i < fdp->fd_knhashmask + 1; i++) { 907 knp = &SLIST_FIRST(&fdp->fd_knhash[i]); 908 kn = *knp; 909 while (kn != NULL) { 910 kn0 = SLIST_NEXT(kn, kn_link); 911 if (kq == kn->kn_kq) { 912 kn->kn_fop->f_detach(kn); 913 /* XXX non-fd release of kn->kn_ptr */ 914 knote_free(kn); 915 *knp = kn0; 916 } else { 917 knp = &SLIST_NEXT(kn, kn_link); 918 } 919 kn = kn0; 920 } 921 } 922 } 923 fp->f_data = NULL; 924 925 kq->kq_state |= KQ_DYING; 926 kqueue_wakeup(kq); 927 KQRELE(kq); 928 929 return (0); 930 } 931 932 void 933 kqueue_wakeup(struct kqueue *kq) 934 { 935 936 if (kq->kq_state & KQ_SLEEP) { 937 kq->kq_state &= ~KQ_SLEEP; 938 wakeup(kq); 939 } 940 if (kq->kq_state & KQ_SEL) { 941 kq->kq_state &= ~KQ_SEL; 942 selwakeup(&kq->kq_sel); 943 } else 944 KNOTE(&kq->kq_sel.si_note, 0); 945 } 946 947 /* 948 * activate one knote. 949 */ 950 void 951 knote_activate(struct knote *kn) 952 { 953 KNOTE_ACTIVATE(kn); 954 } 955 956 /* 957 * walk down a list of knotes, activating them if their event has triggered. 958 */ 959 void 960 knote(struct klist *list, long hint) 961 { 962 struct knote *kn, *kn0; 963 964 SLIST_FOREACH_SAFE(kn, list, kn_selnext, kn0) 965 if (kn->kn_fop->f_event(kn, hint)) 966 KNOTE_ACTIVATE(kn); 967 } 968 969 /* 970 * remove all knotes from a specified klist 971 */ 972 void 973 knote_remove(struct proc *p, struct klist *list) 974 { 975 struct knote *kn; 976 977 while ((kn = SLIST_FIRST(list)) != NULL) { 978 kn->kn_fop->f_detach(kn); 979 knote_drop(kn, p, p->p_fd); 980 } 981 } 982 983 /* 984 * remove all knotes referencing a specified fd 985 */ 986 void 987 knote_fdclose(struct proc *p, int fd) 988 { 989 struct filedesc *fdp = p->p_fd; 990 struct klist *list = &fdp->fd_knlist[fd]; 991 992 knote_remove(p, list); 993 } 994 995 /* 996 * handle a process exiting, including the triggering of NOTE_EXIT notes 997 * XXX this could be more efficient, doing a single pass down the klist 998 */ 999 void 1000 knote_processexit(struct proc *p) 1001 { 1002 struct process *pr = p->p_p; 1003 1004 KNOTE(&pr->ps_klist, NOTE_EXIT); 1005 1006 /* remove other knotes hanging off the process */ 1007 knote_remove(p, &pr->ps_klist); 1008 } 1009 1010 void 1011 knote_attach(struct knote *kn, struct filedesc *fdp) 1012 { 1013 struct klist *list; 1014 int size; 1015 1016 if (!kn->kn_fop->f_isfd) { 1017 if (fdp->fd_knhashmask == 0) 1018 fdp->fd_knhash = hashinit(KN_HASHSIZE, M_TEMP, 1019 M_WAITOK, &fdp->fd_knhashmask); 1020 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; 1021 goto done; 1022 } 1023 1024 if (fdp->fd_knlistsize <= kn->kn_id) { 1025 size = fdp->fd_knlistsize; 1026 while (size <= kn->kn_id) 1027 size += KQEXTENT; 1028 list = mallocarray(size, sizeof(struct klist), M_TEMP, 1029 M_WAITOK); 1030 memcpy(list, fdp->fd_knlist, 1031 fdp->fd_knlistsize * sizeof(struct klist)); 1032 memset(&list[fdp->fd_knlistsize], 0, 1033 (size - fdp->fd_knlistsize) * sizeof(struct klist)); 1034 free(fdp->fd_knlist, M_TEMP, 1035 fdp->fd_knlistsize * sizeof(struct klist)); 1036 fdp->fd_knlistsize = size; 1037 fdp->fd_knlist = list; 1038 } 1039 list = &fdp->fd_knlist[kn->kn_id]; 1040 done: 1041 SLIST_INSERT_HEAD(list, kn, kn_link); 1042 kn->kn_status = 0; 1043 } 1044 1045 /* 1046 * should be called at spl == 0, since we don't want to hold spl 1047 * while calling FRELE and knote_free. 1048 */ 1049 void 1050 knote_drop(struct knote *kn, struct proc *p, struct filedesc *fdp) 1051 { 1052 struct klist *list; 1053 1054 if (kn->kn_fop->f_isfd) 1055 list = &fdp->fd_knlist[kn->kn_id]; 1056 else 1057 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; 1058 1059 SLIST_REMOVE(list, kn, knote, kn_link); 1060 if (kn->kn_status & KN_QUEUED) 1061 knote_dequeue(kn); 1062 if (kn->kn_fop->f_isfd) 1063 FRELE(kn->kn_fp, p); 1064 knote_free(kn); 1065 } 1066 1067 1068 void 1069 knote_enqueue(struct knote *kn) 1070 { 1071 struct kqueue *kq = kn->kn_kq; 1072 int s = splhigh(); 1073 1074 KASSERT((kn->kn_status & KN_QUEUED) == 0); 1075 1076 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 1077 kn->kn_status |= KN_QUEUED; 1078 kq->kq_count++; 1079 splx(s); 1080 kqueue_wakeup(kq); 1081 } 1082 1083 void 1084 knote_dequeue(struct knote *kn) 1085 { 1086 struct kqueue *kq = kn->kn_kq; 1087 int s = splhigh(); 1088 1089 KASSERT(kn->kn_status & KN_QUEUED); 1090 1091 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1092 kn->kn_status &= ~KN_QUEUED; 1093 kq->kq_count--; 1094 splx(s); 1095 } 1096 1097 void 1098 klist_invalidate(struct klist *list) 1099 { 1100 struct knote *kn; 1101 1102 SLIST_FOREACH(kn, list, kn_selnext) { 1103 kn->kn_status |= KN_DETACHED; 1104 kn->kn_flags |= EV_EOF | EV_ONESHOT; 1105 } 1106 } 1107