1 /* $OpenBSD: kern_event.c,v 1.102 2019/05/01 06:22:39 dlg 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 *, struct uio *, int); 62 int kqueue_write(struct file *, struct uio *, int); 63 int kqueue_ioctl(struct file *fp, u_long com, caddr_t data, 64 struct proc *p); 65 int kqueue_poll(struct file *fp, int events, struct proc *p); 66 int kqueue_kqfilter(struct file *fp, struct knote *kn); 67 int kqueue_stat(struct file *fp, struct stat *st, struct proc *p); 68 int kqueue_close(struct file *fp, struct proc *p); 69 void kqueue_wakeup(struct kqueue *kq); 70 71 struct fileops kqueueops = { 72 .fo_read = kqueue_read, 73 .fo_write = kqueue_write, 74 .fo_ioctl = kqueue_ioctl, 75 .fo_poll = kqueue_poll, 76 .fo_kqfilter = kqueue_kqfilter, 77 .fo_stat = kqueue_stat, 78 .fo_close = kqueue_close 79 }; 80 81 void knote_attach(struct knote *kn); 82 void knote_drop(struct knote *kn, struct proc *p); 83 void knote_enqueue(struct knote *kn); 84 void knote_dequeue(struct knote *kn); 85 #define knote_alloc() ((struct knote *)pool_get(&knote_pool, PR_WAITOK)) 86 #define knote_free(kn) pool_put(&knote_pool, (kn)) 87 88 void filt_kqdetach(struct knote *kn); 89 int filt_kqueue(struct knote *kn, long hint); 90 int filt_procattach(struct knote *kn); 91 void filt_procdetach(struct knote *kn); 92 int filt_proc(struct knote *kn, long hint); 93 int filt_fileattach(struct knote *kn); 94 void filt_timerexpire(void *knx); 95 int filt_timerattach(struct knote *kn); 96 void filt_timerdetach(struct knote *kn); 97 int filt_timer(struct knote *kn, long hint); 98 void filt_seltruedetach(struct knote *kn); 99 100 struct filterops kqread_filtops = 101 { 1, NULL, filt_kqdetach, filt_kqueue }; 102 struct filterops proc_filtops = 103 { 0, filt_procattach, filt_procdetach, filt_proc }; 104 struct filterops file_filtops = 105 { 1, filt_fileattach, NULL, NULL }; 106 struct filterops timer_filtops = 107 { 0, filt_timerattach, filt_timerdetach, filt_timer }; 108 109 struct pool knote_pool; 110 struct pool kqueue_pool; 111 int kq_ntimeouts = 0; 112 int kq_timeoutmax = (4 * 1024); 113 114 #define KNOTE_ACTIVATE(kn) do { \ 115 kn->kn_status |= KN_ACTIVE; \ 116 if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 117 knote_enqueue(kn); \ 118 } while(0) 119 120 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 121 122 extern struct filterops sig_filtops; 123 #ifdef notyet 124 extern struct filterops aio_filtops; 125 #endif 126 127 /* 128 * Table for for all system-defined filters. 129 */ 130 struct filterops *sysfilt_ops[] = { 131 &file_filtops, /* EVFILT_READ */ 132 &file_filtops, /* EVFILT_WRITE */ 133 NULL, /*&aio_filtops,*/ /* EVFILT_AIO */ 134 &file_filtops, /* EVFILT_VNODE */ 135 &proc_filtops, /* EVFILT_PROC */ 136 &sig_filtops, /* EVFILT_SIGNAL */ 137 &timer_filtops, /* EVFILT_TIMER */ 138 &file_filtops, /* EVFILT_DEVICE */ 139 }; 140 141 void KQREF(struct kqueue *); 142 void KQRELE(struct kqueue *); 143 144 void 145 KQREF(struct kqueue *kq) 146 { 147 ++kq->kq_refs; 148 } 149 150 void 151 KQRELE(struct kqueue *kq) 152 { 153 if (--kq->kq_refs > 0) 154 return; 155 156 LIST_REMOVE(kq, kq_next); 157 free(kq->kq_knlist, M_TEMP, kq->kq_knlistsize * sizeof(struct klist)); 158 hashfree(kq->kq_knhash, KN_HASHSIZE, M_TEMP); 159 pool_put(&kqueue_pool, kq); 160 } 161 162 void kqueue_init(void); 163 164 void 165 kqueue_init(void) 166 { 167 168 pool_init(&kqueue_pool, sizeof(struct kqueue), 0, IPL_NONE, PR_WAITOK, 169 "kqueuepl", NULL); 170 pool_init(&knote_pool, sizeof(struct knote), 0, IPL_NONE, PR_WAITOK, 171 "knotepl", NULL); 172 } 173 174 int 175 filt_fileattach(struct knote *kn) 176 { 177 struct file *fp = kn->kn_fp; 178 179 return fp->f_ops->fo_kqfilter(fp, kn); 180 } 181 182 int 183 kqueue_kqfilter(struct file *fp, struct knote *kn) 184 { 185 struct kqueue *kq = kn->kn_fp->f_data; 186 187 if (kn->kn_filter != EVFILT_READ) 188 return (EINVAL); 189 190 kn->kn_fop = &kqread_filtops; 191 SLIST_INSERT_HEAD(&kq->kq_sel.si_note, kn, kn_selnext); 192 return (0); 193 } 194 195 void 196 filt_kqdetach(struct knote *kn) 197 { 198 struct kqueue *kq = kn->kn_fp->f_data; 199 200 SLIST_REMOVE(&kq->kq_sel.si_note, kn, knote, kn_selnext); 201 } 202 203 int 204 filt_kqueue(struct knote *kn, long hint) 205 { 206 struct kqueue *kq = kn->kn_fp->f_data; 207 208 kn->kn_data = kq->kq_count; 209 return (kn->kn_data > 0); 210 } 211 212 int 213 filt_procattach(struct knote *kn) 214 { 215 struct process *pr; 216 217 if ((curproc->p_p->ps_flags & PS_PLEDGE) && 218 (curproc->p_p->ps_pledge & PLEDGE_PROC) == 0) 219 return pledge_fail(curproc, EPERM, PLEDGE_PROC); 220 221 if (kn->kn_id > PID_MAX) 222 return ESRCH; 223 224 pr = prfind(kn->kn_id); 225 if (pr == NULL) 226 return (ESRCH); 227 228 /* exiting processes can't be specified */ 229 if (pr->ps_flags & PS_EXITING) 230 return (ESRCH); 231 232 kn->kn_ptr.p_process = pr; 233 kn->kn_flags |= EV_CLEAR; /* automatically set */ 234 235 /* 236 * internal flag indicating registration done by kernel 237 */ 238 if (kn->kn_flags & EV_FLAG1) { 239 kn->kn_data = kn->kn_sdata; /* ppid */ 240 kn->kn_fflags = NOTE_CHILD; 241 kn->kn_flags &= ~EV_FLAG1; 242 } 243 244 /* XXX lock the proc here while adding to the list? */ 245 SLIST_INSERT_HEAD(&pr->ps_klist, kn, kn_selnext); 246 247 return (0); 248 } 249 250 /* 251 * The knote may be attached to a different process, which may exit, 252 * leaving nothing for the knote to be attached to. So when the process 253 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 254 * it will be deleted when read out. However, as part of the knote deletion, 255 * this routine is called, so a check is needed to avoid actually performing 256 * a detach, because the original process does not exist any more. 257 */ 258 void 259 filt_procdetach(struct knote *kn) 260 { 261 struct process *pr = kn->kn_ptr.p_process; 262 263 if (kn->kn_status & KN_DETACHED) 264 return; 265 266 /* XXX locking? this might modify another process. */ 267 SLIST_REMOVE(&pr->ps_klist, kn, knote, kn_selnext); 268 } 269 270 int 271 filt_proc(struct knote *kn, long hint) 272 { 273 u_int event; 274 275 /* 276 * mask off extra data 277 */ 278 event = (u_int)hint & NOTE_PCTRLMASK; 279 280 /* 281 * if the user is interested in this event, record it. 282 */ 283 if (kn->kn_sfflags & event) 284 kn->kn_fflags |= event; 285 286 /* 287 * process is gone, so flag the event as finished and remove it 288 * from the process's klist 289 */ 290 if (event == NOTE_EXIT) { 291 struct process *pr = kn->kn_ptr.p_process; 292 293 kn->kn_status |= KN_DETACHED; 294 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 295 kn->kn_data = pr->ps_mainproc->p_xstat; 296 SLIST_REMOVE(&pr->ps_klist, kn, knote, kn_selnext); 297 return (1); 298 } 299 300 /* 301 * process forked, and user wants to track the new process, 302 * so attach a new knote to it, and immediately report an 303 * event with the parent's pid. 304 */ 305 if ((event == NOTE_FORK) && (kn->kn_sfflags & NOTE_TRACK)) { 306 struct kevent kev; 307 int error; 308 309 /* 310 * register knote with new process. 311 */ 312 memset(&kev, 0, sizeof(kev)); 313 kev.ident = hint & NOTE_PDATAMASK; /* pid */ 314 kev.filter = kn->kn_filter; 315 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 316 kev.fflags = kn->kn_sfflags; 317 kev.data = kn->kn_id; /* parent */ 318 kev.udata = kn->kn_kevent.udata; /* preserve udata */ 319 error = kqueue_register(kn->kn_kq, &kev, NULL); 320 if (error) 321 kn->kn_fflags |= NOTE_TRACKERR; 322 } 323 324 return (kn->kn_fflags != 0); 325 } 326 327 static void 328 filt_timer_timeout_add(struct knote *kn) 329 { 330 struct timeval tv; 331 struct timeout *to = kn->kn_hook; 332 int tticks; 333 334 tv.tv_sec = kn->kn_sdata / 1000; 335 tv.tv_usec = (kn->kn_sdata % 1000) * 1000; 336 tticks = tvtohz(&tv); 337 /* Remove extra tick from tvtohz() if timeout has fired before. */ 338 if (timeout_triggered(to)) 339 tticks--; 340 timeout_add(to, (tticks > 0) ? tticks : 1); 341 } 342 343 void 344 filt_timerexpire(void *knx) 345 { 346 struct knote *kn = knx; 347 348 kn->kn_data++; 349 KNOTE_ACTIVATE(kn); 350 351 if ((kn->kn_flags & EV_ONESHOT) == 0) 352 filt_timer_timeout_add(kn); 353 } 354 355 356 /* 357 * data contains amount of time to sleep, in milliseconds 358 */ 359 int 360 filt_timerattach(struct knote *kn) 361 { 362 struct timeout *to; 363 364 if (kq_ntimeouts > kq_timeoutmax) 365 return (ENOMEM); 366 kq_ntimeouts++; 367 368 kn->kn_flags |= EV_CLEAR; /* automatically set */ 369 to = malloc(sizeof(*to), M_KEVENT, M_WAITOK); 370 timeout_set(to, filt_timerexpire, kn); 371 kn->kn_hook = to; 372 filt_timer_timeout_add(kn); 373 374 return (0); 375 } 376 377 void 378 filt_timerdetach(struct knote *kn) 379 { 380 struct timeout *to; 381 382 to = (struct timeout *)kn->kn_hook; 383 timeout_del(to); 384 free(to, M_KEVENT, sizeof(*to)); 385 kq_ntimeouts--; 386 } 387 388 int 389 filt_timer(struct knote *kn, long hint) 390 { 391 return (kn->kn_data != 0); 392 } 393 394 395 /* 396 * filt_seltrue: 397 * 398 * This filter "event" routine simulates seltrue(). 399 */ 400 int 401 filt_seltrue(struct knote *kn, long hint) 402 { 403 404 /* 405 * We don't know how much data can be read/written, 406 * but we know that it *can* be. This is about as 407 * good as select/poll does as well. 408 */ 409 kn->kn_data = 0; 410 return (1); 411 } 412 413 /* 414 * This provides full kqfilter entry for device switch tables, which 415 * has same effect as filter using filt_seltrue() as filter method. 416 */ 417 void 418 filt_seltruedetach(struct knote *kn) 419 { 420 /* Nothing to do */ 421 } 422 423 const struct filterops seltrue_filtops = 424 { 1, NULL, filt_seltruedetach, filt_seltrue }; 425 426 int 427 seltrue_kqfilter(dev_t dev, struct knote *kn) 428 { 429 switch (kn->kn_filter) { 430 case EVFILT_READ: 431 case EVFILT_WRITE: 432 kn->kn_fop = &seltrue_filtops; 433 break; 434 default: 435 return (EINVAL); 436 } 437 438 /* Nothing more to do */ 439 return (0); 440 } 441 442 int 443 sys_kqueue(struct proc *p, void *v, register_t *retval) 444 { 445 struct filedesc *fdp = p->p_fd; 446 struct kqueue *kq; 447 struct file *fp; 448 int fd, error; 449 450 fdplock(fdp); 451 error = falloc(p, &fp, &fd); 452 if (error) 453 goto out; 454 fp->f_flag = FREAD | FWRITE; 455 fp->f_type = DTYPE_KQUEUE; 456 fp->f_ops = &kqueueops; 457 kq = pool_get(&kqueue_pool, PR_WAITOK|PR_ZERO); 458 TAILQ_INIT(&kq->kq_head); 459 fp->f_data = kq; 460 KQREF(kq); 461 *retval = fd; 462 kq->kq_fdp = fdp; 463 LIST_INSERT_HEAD(&p->p_p->ps_kqlist, kq, kq_next); 464 fdinsert(fdp, fd, 0, fp); 465 FRELE(fp, p); 466 out: 467 fdpunlock(fdp); 468 return (error); 469 } 470 471 int 472 sys_kevent(struct proc *p, void *v, register_t *retval) 473 { 474 struct filedesc* fdp = p->p_fd; 475 struct sys_kevent_args /* { 476 syscallarg(int) fd; 477 syscallarg(const struct kevent *) changelist; 478 syscallarg(int) nchanges; 479 syscallarg(struct kevent *) eventlist; 480 syscallarg(int) nevents; 481 syscallarg(const struct timespec *) timeout; 482 } */ *uap = v; 483 struct kevent *kevp; 484 struct kqueue *kq; 485 struct file *fp; 486 struct timespec ts; 487 int i, n, nerrors, error; 488 struct kevent kev[KQ_NEVENTS]; 489 490 if ((fp = fd_getfile(fdp, SCARG(uap, fd))) == NULL) 491 return (EBADF); 492 493 if (fp->f_type != DTYPE_KQUEUE) { 494 error = EBADF; 495 goto done; 496 } 497 498 if (SCARG(uap, timeout) != NULL) { 499 error = copyin(SCARG(uap, timeout), &ts, sizeof(ts)); 500 if (error) 501 goto done; 502 #ifdef KTRACE 503 if (KTRPOINT(p, KTR_STRUCT)) 504 ktrreltimespec(p, &ts); 505 #endif 506 SCARG(uap, timeout) = &ts; 507 } 508 509 kq = fp->f_data; 510 nerrors = 0; 511 512 while (SCARG(uap, nchanges) > 0) { 513 n = SCARG(uap, nchanges) > KQ_NEVENTS ? 514 KQ_NEVENTS : SCARG(uap, nchanges); 515 error = copyin(SCARG(uap, changelist), kev, 516 n * sizeof(struct kevent)); 517 if (error) 518 goto done; 519 #ifdef KTRACE 520 if (KTRPOINT(p, KTR_STRUCT)) 521 ktrevent(p, kev, n); 522 #endif 523 for (i = 0; i < n; i++) { 524 kevp = &kev[i]; 525 kevp->flags &= ~EV_SYSFLAGS; 526 error = kqueue_register(kq, kevp, p); 527 if (error || (kevp->flags & EV_RECEIPT)) { 528 if (SCARG(uap, nevents) != 0) { 529 kevp->flags = EV_ERROR; 530 kevp->data = error; 531 copyout(kevp, SCARG(uap, eventlist), 532 sizeof(*kevp)); 533 SCARG(uap, eventlist)++; 534 SCARG(uap, nevents)--; 535 nerrors++; 536 } else { 537 goto done; 538 } 539 } 540 } 541 SCARG(uap, nchanges) -= n; 542 SCARG(uap, changelist) += n; 543 } 544 if (nerrors) { 545 *retval = nerrors; 546 error = 0; 547 goto done; 548 } 549 550 KQREF(kq); 551 FRELE(fp, p); 552 error = kqueue_scan(kq, SCARG(uap, nevents), SCARG(uap, eventlist), 553 SCARG(uap, timeout), p, &n); 554 KQRELE(kq); 555 *retval = n; 556 return (error); 557 558 done: 559 FRELE(fp, p); 560 return (error); 561 } 562 563 int 564 kqueue_register(struct kqueue *kq, struct kevent *kev, struct proc *p) 565 { 566 struct filedesc *fdp = kq->kq_fdp; 567 struct filterops *fops = NULL; 568 struct file *fp = NULL; 569 struct knote *kn = NULL; 570 int s, error = 0; 571 572 if (kev->filter < 0) { 573 if (kev->filter + EVFILT_SYSCOUNT < 0) 574 return (EINVAL); 575 fops = sysfilt_ops[~kev->filter]; /* to 0-base index */ 576 } 577 578 if (fops == NULL) { 579 /* 580 * XXX 581 * filter attach routine is responsible for ensuring that 582 * the identifier can be attached to it. 583 */ 584 return (EINVAL); 585 } 586 587 if (fops->f_isfd) { 588 /* validate descriptor */ 589 if (kev->ident > INT_MAX) 590 return (EBADF); 591 if ((fp = fd_getfile(fdp, kev->ident)) == NULL) 592 return (EBADF); 593 594 if (kev->ident < kq->kq_knlistsize) { 595 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link) { 596 if (kev->filter == kn->kn_filter) 597 break; 598 } 599 } 600 } else { 601 if (kq->kq_knhashmask != 0) { 602 struct klist *list; 603 604 list = &kq->kq_knhash[ 605 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)]; 606 SLIST_FOREACH(kn, list, kn_link) { 607 if (kev->ident == kn->kn_id && 608 kev->filter == kn->kn_filter) 609 break; 610 } 611 } 612 } 613 614 if (kn == NULL && ((kev->flags & EV_ADD) == 0)) { 615 error = ENOENT; 616 goto done; 617 } 618 619 /* 620 * kn now contains the matching knote, or NULL if no match 621 */ 622 if (kev->flags & EV_ADD) { 623 624 if (kn == NULL) { 625 kn = knote_alloc(); 626 if (kn == NULL) { 627 error = ENOMEM; 628 goto done; 629 } 630 kn->kn_fp = fp; 631 kn->kn_kq = kq; 632 kn->kn_fop = fops; 633 634 /* 635 * apply reference count to knote structure, and 636 * do not release it at the end of this routine. 637 */ 638 fp = NULL; 639 640 kn->kn_sfflags = kev->fflags; 641 kn->kn_sdata = kev->data; 642 kev->fflags = 0; 643 kev->data = 0; 644 kn->kn_kevent = *kev; 645 646 knote_attach(kn); 647 if ((error = fops->f_attach(kn)) != 0) { 648 knote_drop(kn, p); 649 goto done; 650 } 651 } else { 652 /* 653 * The user may change some filter values after the 654 * initial EV_ADD, but doing so will not reset any 655 * filters which have already been triggered. 656 */ 657 kn->kn_sfflags = kev->fflags; 658 kn->kn_sdata = kev->data; 659 kn->kn_kevent.udata = kev->udata; 660 } 661 662 s = splhigh(); 663 if (kn->kn_fop->f_event(kn, 0)) 664 KNOTE_ACTIVATE(kn); 665 splx(s); 666 667 } else if (kev->flags & EV_DELETE) { 668 kn->kn_fop->f_detach(kn); 669 knote_drop(kn, p); 670 goto done; 671 } 672 673 if ((kev->flags & EV_DISABLE) && 674 ((kn->kn_status & KN_DISABLED) == 0)) { 675 s = splhigh(); 676 kn->kn_status |= KN_DISABLED; 677 splx(s); 678 } 679 680 if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) { 681 s = splhigh(); 682 kn->kn_status &= ~KN_DISABLED; 683 if (kn->kn_fop->f_event(kn, 0)) 684 kn->kn_status |= KN_ACTIVE; 685 if ((kn->kn_status & KN_ACTIVE) && 686 ((kn->kn_status & KN_QUEUED) == 0)) 687 knote_enqueue(kn); 688 splx(s); 689 } 690 691 done: 692 if (fp != NULL) 693 FRELE(fp, p); 694 return (error); 695 } 696 697 int 698 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent *ulistp, 699 const struct timespec *tsp, struct proc *p, int *retval) 700 { 701 struct kevent *kevp; 702 struct timespec ats, rts, tts; 703 struct knote *kn, marker; 704 int s, count, timeout, nkev = 0, error = 0; 705 struct kevent kev[KQ_NEVENTS]; 706 707 count = maxevents; 708 if (count == 0) 709 goto done; 710 711 if (tsp != NULL) { 712 ats = *tsp; 713 if (!timespecisset(&ats)) { 714 /* No timeout, just poll */ 715 timeout = -1; 716 goto start; 717 } 718 if (timespecfix(&ats)) { 719 error = EINVAL; 720 goto done; 721 } 722 723 timeout = ats.tv_sec > 24 * 60 * 60 ? 724 24 * 60 * 60 * hz : tstohz(&ats); 725 726 getnanouptime(&rts); 727 timespecadd(&ats, &rts, &ats); 728 } else { 729 timespecclear(&ats); 730 timeout = 0; 731 } 732 goto start; 733 734 retry: 735 if (timespecisset(&ats)) { 736 getnanouptime(&rts); 737 if (timespeccmp(&rts, &ats, >=)) 738 goto done; 739 tts = ats; 740 timespecsub(&tts, &rts, &tts); 741 timeout = tts.tv_sec > 24 * 60 * 60 ? 742 24 * 60 * 60 * hz : tstohz(&tts); 743 } 744 745 start: 746 if (kq->kq_state & KQ_DYING) { 747 error = EBADF; 748 goto done; 749 } 750 751 kevp = &kev[0]; 752 s = splhigh(); 753 if (kq->kq_count == 0) { 754 if (timeout < 0) { 755 error = EWOULDBLOCK; 756 } else { 757 kq->kq_state |= KQ_SLEEP; 758 error = tsleep(kq, PSOCK | PCATCH, "kqread", timeout); 759 } 760 splx(s); 761 if (error == 0) 762 goto retry; 763 /* don't restart after signals... */ 764 if (error == ERESTART) 765 error = EINTR; 766 else if (error == EWOULDBLOCK) 767 error = 0; 768 goto done; 769 } 770 771 TAILQ_INSERT_TAIL(&kq->kq_head, &marker, kn_tqe); 772 while (count) { 773 kn = TAILQ_FIRST(&kq->kq_head); 774 if (kn == &marker) { 775 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 776 splx(s); 777 if (count == maxevents) 778 goto retry; 779 goto done; 780 } 781 782 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 783 kq->kq_count--; 784 785 if (kn->kn_status & KN_DISABLED) { 786 kn->kn_status &= ~KN_QUEUED; 787 continue; 788 } 789 if ((kn->kn_flags & EV_ONESHOT) == 0 && 790 kn->kn_fop->f_event(kn, 0) == 0) { 791 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 792 continue; 793 } 794 *kevp = kn->kn_kevent; 795 kevp++; 796 nkev++; 797 if (kn->kn_flags & EV_ONESHOT) { 798 kn->kn_status &= ~KN_QUEUED; 799 splx(s); 800 kn->kn_fop->f_detach(kn); 801 knote_drop(kn, p); 802 s = splhigh(); 803 } else if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) { 804 if (kn->kn_flags & EV_CLEAR) { 805 kn->kn_data = 0; 806 kn->kn_fflags = 0; 807 } 808 if (kn->kn_flags & EV_DISPATCH) 809 kn->kn_status |= KN_DISABLED; 810 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 811 } else { 812 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 813 kq->kq_count++; 814 } 815 count--; 816 if (nkev == KQ_NEVENTS) { 817 splx(s); 818 #ifdef KTRACE 819 if (KTRPOINT(p, KTR_STRUCT)) 820 ktrevent(p, kev, nkev); 821 #endif 822 error = copyout(kev, ulistp, 823 sizeof(struct kevent) * nkev); 824 ulistp += nkev; 825 nkev = 0; 826 kevp = &kev[0]; 827 s = splhigh(); 828 if (error) 829 break; 830 } 831 } 832 TAILQ_REMOVE(&kq->kq_head, &marker, kn_tqe); 833 splx(s); 834 done: 835 if (nkev != 0) { 836 #ifdef KTRACE 837 if (KTRPOINT(p, KTR_STRUCT)) 838 ktrevent(p, kev, nkev); 839 #endif 840 error = copyout(kev, ulistp, 841 sizeof(struct kevent) * nkev); 842 } 843 *retval = maxevents - count; 844 return (error); 845 } 846 847 /* 848 * XXX 849 * This could be expanded to call kqueue_scan, if desired. 850 */ 851 int 852 kqueue_read(struct file *fp, struct uio *uio, int fflags) 853 { 854 return (ENXIO); 855 } 856 857 int 858 kqueue_write(struct file *fp, struct uio *uio, int fflags) 859 { 860 return (ENXIO); 861 } 862 863 int 864 kqueue_ioctl(struct file *fp, u_long com, caddr_t data, struct proc *p) 865 { 866 return (ENOTTY); 867 } 868 869 int 870 kqueue_poll(struct file *fp, int events, struct proc *p) 871 { 872 struct kqueue *kq = (struct kqueue *)fp->f_data; 873 int revents = 0; 874 int s = splhigh(); 875 876 if (events & (POLLIN | POLLRDNORM)) { 877 if (kq->kq_count) { 878 revents |= events & (POLLIN | POLLRDNORM); 879 } else { 880 selrecord(p, &kq->kq_sel); 881 kq->kq_state |= KQ_SEL; 882 } 883 } 884 splx(s); 885 return (revents); 886 } 887 888 int 889 kqueue_stat(struct file *fp, struct stat *st, struct proc *p) 890 { 891 struct kqueue *kq = fp->f_data; 892 893 memset(st, 0, sizeof(*st)); 894 st->st_size = kq->kq_count; 895 st->st_blksize = sizeof(struct kevent); 896 st->st_mode = S_IFIFO; 897 return (0); 898 } 899 900 int 901 kqueue_close(struct file *fp, struct proc *p) 902 { 903 struct kqueue *kq = fp->f_data; 904 int i; 905 906 KERNEL_LOCK(); 907 908 for (i = 0; i < kq->kq_knlistsize; i++) 909 knote_remove(p, &kq->kq_knlist[i]); 910 if (kq->kq_knhashmask != 0) { 911 for (i = 0; i < kq->kq_knhashmask + 1; i++) 912 knote_remove(p, &kq->kq_knhash[i]); 913 } 914 fp->f_data = NULL; 915 916 kq->kq_state |= KQ_DYING; 917 kqueue_wakeup(kq); 918 KQRELE(kq); 919 920 KERNEL_UNLOCK(); 921 922 return (0); 923 } 924 925 void 926 kqueue_wakeup(struct kqueue *kq) 927 { 928 929 if (kq->kq_state & KQ_SLEEP) { 930 kq->kq_state &= ~KQ_SLEEP; 931 wakeup(kq); 932 } 933 if (kq->kq_state & KQ_SEL) { 934 kq->kq_state &= ~KQ_SEL; 935 selwakeup(&kq->kq_sel); 936 } else 937 KNOTE(&kq->kq_sel.si_note, 0); 938 } 939 940 /* 941 * activate one knote. 942 */ 943 void 944 knote_activate(struct knote *kn) 945 { 946 KNOTE_ACTIVATE(kn); 947 } 948 949 /* 950 * walk down a list of knotes, activating them if their event has triggered. 951 */ 952 void 953 knote(struct klist *list, long hint) 954 { 955 struct knote *kn, *kn0; 956 957 SLIST_FOREACH_SAFE(kn, list, kn_selnext, kn0) 958 if (kn->kn_fop->f_event(kn, hint)) 959 KNOTE_ACTIVATE(kn); 960 } 961 962 /* 963 * remove all knotes from a specified klist 964 */ 965 void 966 knote_remove(struct proc *p, struct klist *list) 967 { 968 struct knote *kn; 969 970 while ((kn = SLIST_FIRST(list)) != NULL) { 971 kn->kn_fop->f_detach(kn); 972 knote_drop(kn, p); 973 } 974 } 975 976 /* 977 * remove all knotes referencing a specified fd 978 */ 979 void 980 knote_fdclose(struct proc *p, int fd) 981 { 982 struct kqueue *kq; 983 struct klist *list; 984 985 LIST_FOREACH(kq, &p->p_p->ps_kqlist, kq_next) { 986 if (fd >= kq->kq_knlistsize) 987 continue; 988 989 list = &kq->kq_knlist[fd]; 990 knote_remove(p, list); 991 } 992 } 993 994 /* 995 * handle a process exiting, including the triggering of NOTE_EXIT notes 996 * XXX this could be more efficient, doing a single pass down the klist 997 */ 998 void 999 knote_processexit(struct proc *p) 1000 { 1001 struct process *pr = p->p_p; 1002 1003 KNOTE(&pr->ps_klist, NOTE_EXIT); 1004 1005 /* remove other knotes hanging off the process */ 1006 knote_remove(p, &pr->ps_klist); 1007 } 1008 1009 void 1010 knote_attach(struct knote *kn) 1011 { 1012 struct kqueue *kq = kn->kn_kq; 1013 struct klist *list; 1014 int size; 1015 1016 if (!kn->kn_fop->f_isfd) { 1017 if (kq->kq_knhashmask == 0) 1018 kq->kq_knhash = hashinit(KN_HASHSIZE, M_TEMP, 1019 M_WAITOK, &kq->kq_knhashmask); 1020 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 1021 goto done; 1022 } 1023 1024 if (kq->kq_knlistsize <= kn->kn_id) { 1025 size = kq->kq_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, kq->kq_knlist, 1031 kq->kq_knlistsize * sizeof(struct klist)); 1032 memset(&list[kq->kq_knlistsize], 0, 1033 (size - kq->kq_knlistsize) * sizeof(struct klist)); 1034 free(kq->kq_knlist, M_TEMP, 1035 kq->kq_knlistsize * sizeof(struct klist)); 1036 kq->kq_knlistsize = size; 1037 kq->kq_knlist = list; 1038 } 1039 list = &kq->kq_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) 1051 { 1052 struct kqueue *kq = kn->kn_kq; 1053 struct klist *list; 1054 1055 if (kn->kn_fop->f_isfd) 1056 list = &kq->kq_knlist[kn->kn_id]; 1057 else 1058 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 1059 1060 SLIST_REMOVE(list, kn, knote, kn_link); 1061 if (kn->kn_status & KN_QUEUED) 1062 knote_dequeue(kn); 1063 if (kn->kn_fop->f_isfd) 1064 FRELE(kn->kn_fp, p); 1065 knote_free(kn); 1066 } 1067 1068 1069 void 1070 knote_enqueue(struct knote *kn) 1071 { 1072 struct kqueue *kq = kn->kn_kq; 1073 int s = splhigh(); 1074 1075 KASSERT((kn->kn_status & KN_QUEUED) == 0); 1076 KERNEL_ASSERT_LOCKED(); 1077 1078 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 1079 kn->kn_status |= KN_QUEUED; 1080 kq->kq_count++; 1081 splx(s); 1082 kqueue_wakeup(kq); 1083 } 1084 1085 void 1086 knote_dequeue(struct knote *kn) 1087 { 1088 struct kqueue *kq = kn->kn_kq; 1089 int s = splhigh(); 1090 1091 KASSERT(kn->kn_status & KN_QUEUED); 1092 KERNEL_ASSERT_LOCKED(); 1093 1094 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1095 kn->kn_status &= ~KN_QUEUED; 1096 kq->kq_count--; 1097 splx(s); 1098 } 1099 1100 void 1101 klist_invalidate(struct klist *list) 1102 { 1103 struct knote *kn; 1104 1105 SLIST_FOREACH(kn, list, kn_selnext) { 1106 kn->kn_status |= KN_DETACHED; 1107 kn->kn_flags |= EV_EOF | EV_ONESHOT; 1108 } 1109 } 1110