1 /* $NetBSD: kern_event.c,v 1.86 2016/04/04 20:47:57 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 2008, 2009 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Andrew Doran. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /*- 33 * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org> 34 * All rights reserved. 35 * 36 * Redistribution and use in source and binary forms, with or without 37 * modification, are permitted provided that the following conditions 38 * are met: 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 45 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 46 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 47 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 48 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 49 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 50 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 51 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 52 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 53 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 54 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 55 * SUCH DAMAGE. 56 * 57 * FreeBSD: src/sys/kern/kern_event.c,v 1.27 2001/07/05 17:10:44 rwatson Exp 58 */ 59 60 #include <sys/cdefs.h> 61 __KERNEL_RCSID(0, "$NetBSD: kern_event.c,v 1.86 2016/04/04 20:47:57 christos Exp $"); 62 63 #include <sys/param.h> 64 #include <sys/systm.h> 65 #include <sys/kernel.h> 66 #include <sys/wait.h> 67 #include <sys/proc.h> 68 #include <sys/file.h> 69 #include <sys/select.h> 70 #include <sys/queue.h> 71 #include <sys/event.h> 72 #include <sys/eventvar.h> 73 #include <sys/poll.h> 74 #include <sys/kmem.h> 75 #include <sys/stat.h> 76 #include <sys/filedesc.h> 77 #include <sys/syscallargs.h> 78 #include <sys/kauth.h> 79 #include <sys/conf.h> 80 #include <sys/atomic.h> 81 82 static int kqueue_scan(file_t *, size_t, struct kevent *, 83 const struct timespec *, register_t *, 84 const struct kevent_ops *, struct kevent *, 85 size_t); 86 static int kqueue_ioctl(file_t *, u_long, void *); 87 static int kqueue_fcntl(file_t *, u_int, void *); 88 static int kqueue_poll(file_t *, int); 89 static int kqueue_kqfilter(file_t *, struct knote *); 90 static int kqueue_stat(file_t *, struct stat *); 91 static int kqueue_close(file_t *); 92 static int kqueue_register(struct kqueue *, struct kevent *); 93 static void kqueue_doclose(struct kqueue *, struct klist *, int); 94 95 static void knote_detach(struct knote *, filedesc_t *fdp, bool); 96 static void knote_enqueue(struct knote *); 97 static void knote_activate(struct knote *); 98 99 static void filt_kqdetach(struct knote *); 100 static int filt_kqueue(struct knote *, long hint); 101 static int filt_procattach(struct knote *); 102 static void filt_procdetach(struct knote *); 103 static int filt_proc(struct knote *, long hint); 104 static int filt_fileattach(struct knote *); 105 static void filt_timerexpire(void *x); 106 static int filt_timerattach(struct knote *); 107 static void filt_timerdetach(struct knote *); 108 static int filt_timer(struct knote *, long hint); 109 110 static const struct fileops kqueueops = { 111 .fo_read = (void *)enxio, 112 .fo_write = (void *)enxio, 113 .fo_ioctl = kqueue_ioctl, 114 .fo_fcntl = kqueue_fcntl, 115 .fo_poll = kqueue_poll, 116 .fo_stat = kqueue_stat, 117 .fo_close = kqueue_close, 118 .fo_kqfilter = kqueue_kqfilter, 119 .fo_restart = fnullop_restart, 120 }; 121 122 static const struct filterops kqread_filtops = 123 { 1, NULL, filt_kqdetach, filt_kqueue }; 124 static const struct filterops proc_filtops = 125 { 0, filt_procattach, filt_procdetach, filt_proc }; 126 static const struct filterops file_filtops = 127 { 1, filt_fileattach, NULL, NULL }; 128 static const struct filterops timer_filtops = 129 { 0, filt_timerattach, filt_timerdetach, filt_timer }; 130 131 static u_int kq_ncallouts = 0; 132 static int kq_calloutmax = (4 * 1024); 133 134 #define KN_HASHSIZE 64 /* XXX should be tunable */ 135 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 136 137 extern const struct filterops sig_filtops; 138 139 /* 140 * Table for for all system-defined filters. 141 * These should be listed in the numeric order of the EVFILT_* defines. 142 * If filtops is NULL, the filter isn't implemented in NetBSD. 143 * End of list is when name is NULL. 144 * 145 * Note that 'refcnt' is meaningless for built-in filters. 146 */ 147 struct kfilter { 148 const char *name; /* name of filter */ 149 uint32_t filter; /* id of filter */ 150 unsigned refcnt; /* reference count */ 151 const struct filterops *filtops;/* operations for filter */ 152 size_t namelen; /* length of name string */ 153 }; 154 155 /* System defined filters */ 156 static struct kfilter sys_kfilters[] = { 157 { "EVFILT_READ", EVFILT_READ, 0, &file_filtops, 0 }, 158 { "EVFILT_WRITE", EVFILT_WRITE, 0, &file_filtops, 0, }, 159 { "EVFILT_AIO", EVFILT_AIO, 0, NULL, 0 }, 160 { "EVFILT_VNODE", EVFILT_VNODE, 0, &file_filtops, 0 }, 161 { "EVFILT_PROC", EVFILT_PROC, 0, &proc_filtops, 0 }, 162 { "EVFILT_SIGNAL", EVFILT_SIGNAL, 0, &sig_filtops, 0 }, 163 { "EVFILT_TIMER", EVFILT_TIMER, 0, &timer_filtops, 0 }, 164 { NULL, 0, 0, NULL, 0 }, 165 }; 166 167 /* User defined kfilters */ 168 static struct kfilter *user_kfilters; /* array */ 169 static int user_kfilterc; /* current offset */ 170 static int user_kfiltermaxc; /* max size so far */ 171 static size_t user_kfiltersz; /* size of allocated memory */ 172 173 /* Locks */ 174 static krwlock_t kqueue_filter_lock; /* lock on filter lists */ 175 static kmutex_t kqueue_misc_lock; /* miscellaneous */ 176 177 static kauth_listener_t kqueue_listener; 178 179 static int 180 kqueue_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie, 181 void *arg0, void *arg1, void *arg2, void *arg3) 182 { 183 struct proc *p; 184 int result; 185 186 result = KAUTH_RESULT_DEFER; 187 p = arg0; 188 189 if (action != KAUTH_PROCESS_KEVENT_FILTER) 190 return result; 191 192 if ((kauth_cred_getuid(p->p_cred) != kauth_cred_getuid(cred) || 193 ISSET(p->p_flag, PK_SUGID))) 194 return result; 195 196 result = KAUTH_RESULT_ALLOW; 197 198 return result; 199 } 200 201 /* 202 * Initialize the kqueue subsystem. 203 */ 204 void 205 kqueue_init(void) 206 { 207 208 rw_init(&kqueue_filter_lock); 209 mutex_init(&kqueue_misc_lock, MUTEX_DEFAULT, IPL_NONE); 210 211 kqueue_listener = kauth_listen_scope(KAUTH_SCOPE_PROCESS, 212 kqueue_listener_cb, NULL); 213 } 214 215 /* 216 * Find kfilter entry by name, or NULL if not found. 217 */ 218 static struct kfilter * 219 kfilter_byname_sys(const char *name) 220 { 221 int i; 222 223 KASSERT(rw_lock_held(&kqueue_filter_lock)); 224 225 for (i = 0; sys_kfilters[i].name != NULL; i++) { 226 if (strcmp(name, sys_kfilters[i].name) == 0) 227 return &sys_kfilters[i]; 228 } 229 return NULL; 230 } 231 232 static struct kfilter * 233 kfilter_byname_user(const char *name) 234 { 235 int i; 236 237 KASSERT(rw_lock_held(&kqueue_filter_lock)); 238 239 /* user filter slots have a NULL name if previously deregistered */ 240 for (i = 0; i < user_kfilterc ; i++) { 241 if (user_kfilters[i].name != NULL && 242 strcmp(name, user_kfilters[i].name) == 0) 243 return &user_kfilters[i]; 244 } 245 return NULL; 246 } 247 248 static struct kfilter * 249 kfilter_byname(const char *name) 250 { 251 struct kfilter *kfilter; 252 253 KASSERT(rw_lock_held(&kqueue_filter_lock)); 254 255 if ((kfilter = kfilter_byname_sys(name)) != NULL) 256 return kfilter; 257 258 return kfilter_byname_user(name); 259 } 260 261 /* 262 * Find kfilter entry by filter id, or NULL if not found. 263 * Assumes entries are indexed in filter id order, for speed. 264 */ 265 static struct kfilter * 266 kfilter_byfilter(uint32_t filter) 267 { 268 struct kfilter *kfilter; 269 270 KASSERT(rw_lock_held(&kqueue_filter_lock)); 271 272 if (filter < EVFILT_SYSCOUNT) /* it's a system filter */ 273 kfilter = &sys_kfilters[filter]; 274 else if (user_kfilters != NULL && 275 filter < EVFILT_SYSCOUNT + user_kfilterc) 276 /* it's a user filter */ 277 kfilter = &user_kfilters[filter - EVFILT_SYSCOUNT]; 278 else 279 return (NULL); /* out of range */ 280 KASSERT(kfilter->filter == filter); /* sanity check! */ 281 return (kfilter); 282 } 283 284 /* 285 * Register a new kfilter. Stores the entry in user_kfilters. 286 * Returns 0 if operation succeeded, or an appropriate errno(2) otherwise. 287 * If retfilter != NULL, the new filterid is returned in it. 288 */ 289 int 290 kfilter_register(const char *name, const struct filterops *filtops, 291 int *retfilter) 292 { 293 struct kfilter *kfilter; 294 size_t len; 295 int i; 296 297 if (name == NULL || name[0] == '\0' || filtops == NULL) 298 return (EINVAL); /* invalid args */ 299 300 rw_enter(&kqueue_filter_lock, RW_WRITER); 301 if (kfilter_byname(name) != NULL) { 302 rw_exit(&kqueue_filter_lock); 303 return (EEXIST); /* already exists */ 304 } 305 if (user_kfilterc > 0xffffffff - EVFILT_SYSCOUNT) { 306 rw_exit(&kqueue_filter_lock); 307 return (EINVAL); /* too many */ 308 } 309 310 for (i = 0; i < user_kfilterc; i++) { 311 kfilter = &user_kfilters[i]; 312 if (kfilter->name == NULL) { 313 /* Previously deregistered slot. Reuse. */ 314 goto reuse; 315 } 316 } 317 318 /* check if need to grow user_kfilters */ 319 if (user_kfilterc + 1 > user_kfiltermaxc) { 320 /* Grow in KFILTER_EXTENT chunks. */ 321 user_kfiltermaxc += KFILTER_EXTENT; 322 len = user_kfiltermaxc * sizeof(*kfilter); 323 kfilter = kmem_alloc(len, KM_SLEEP); 324 memset((char *)kfilter + user_kfiltersz, 0, len - user_kfiltersz); 325 if (user_kfilters != NULL) { 326 memcpy(kfilter, user_kfilters, user_kfiltersz); 327 kmem_free(user_kfilters, user_kfiltersz); 328 } 329 user_kfiltersz = len; 330 user_kfilters = kfilter; 331 } 332 /* Adding new slot */ 333 kfilter = &user_kfilters[user_kfilterc++]; 334 reuse: 335 kfilter->namelen = strlen(name) + 1; 336 kfilter->name = kmem_alloc(kfilter->namelen, KM_SLEEP); 337 memcpy(__UNCONST(kfilter->name), name, kfilter->namelen); 338 339 kfilter->filter = (kfilter - user_kfilters) + EVFILT_SYSCOUNT; 340 341 kfilter->filtops = kmem_alloc(sizeof(*filtops), KM_SLEEP); 342 memcpy(__UNCONST(kfilter->filtops), filtops, sizeof(*filtops)); 343 344 if (retfilter != NULL) 345 *retfilter = kfilter->filter; 346 rw_exit(&kqueue_filter_lock); 347 348 return (0); 349 } 350 351 /* 352 * Unregister a kfilter previously registered with kfilter_register. 353 * This retains the filter id, but clears the name and frees filtops (filter 354 * operations), so that the number isn't reused during a boot. 355 * Returns 0 if operation succeeded, or an appropriate errno(2) otherwise. 356 */ 357 int 358 kfilter_unregister(const char *name) 359 { 360 struct kfilter *kfilter; 361 362 if (name == NULL || name[0] == '\0') 363 return (EINVAL); /* invalid name */ 364 365 rw_enter(&kqueue_filter_lock, RW_WRITER); 366 if (kfilter_byname_sys(name) != NULL) { 367 rw_exit(&kqueue_filter_lock); 368 return (EINVAL); /* can't detach system filters */ 369 } 370 371 kfilter = kfilter_byname_user(name); 372 if (kfilter == NULL) { 373 rw_exit(&kqueue_filter_lock); 374 return (ENOENT); 375 } 376 if (kfilter->refcnt != 0) { 377 rw_exit(&kqueue_filter_lock); 378 return (EBUSY); 379 } 380 381 /* Cast away const (but we know it's safe. */ 382 kmem_free(__UNCONST(kfilter->name), kfilter->namelen); 383 kfilter->name = NULL; /* mark as `not implemented' */ 384 385 if (kfilter->filtops != NULL) { 386 /* Cast away const (but we know it's safe. */ 387 kmem_free(__UNCONST(kfilter->filtops), 388 sizeof(*kfilter->filtops)); 389 kfilter->filtops = NULL; /* mark as `not implemented' */ 390 } 391 rw_exit(&kqueue_filter_lock); 392 393 return (0); 394 } 395 396 397 /* 398 * Filter attach method for EVFILT_READ and EVFILT_WRITE on normal file 399 * descriptors. Calls fileops kqfilter method for given file descriptor. 400 */ 401 static int 402 filt_fileattach(struct knote *kn) 403 { 404 file_t *fp; 405 406 fp = kn->kn_obj; 407 408 return (*fp->f_ops->fo_kqfilter)(fp, kn); 409 } 410 411 /* 412 * Filter detach method for EVFILT_READ on kqueue descriptor. 413 */ 414 static void 415 filt_kqdetach(struct knote *kn) 416 { 417 struct kqueue *kq; 418 419 kq = ((file_t *)kn->kn_obj)->f_kqueue; 420 421 mutex_spin_enter(&kq->kq_lock); 422 SLIST_REMOVE(&kq->kq_sel.sel_klist, kn, knote, kn_selnext); 423 mutex_spin_exit(&kq->kq_lock); 424 } 425 426 /* 427 * Filter event method for EVFILT_READ on kqueue descriptor. 428 */ 429 /*ARGSUSED*/ 430 static int 431 filt_kqueue(struct knote *kn, long hint) 432 { 433 struct kqueue *kq; 434 int rv; 435 436 kq = ((file_t *)kn->kn_obj)->f_kqueue; 437 438 if (hint != NOTE_SUBMIT) 439 mutex_spin_enter(&kq->kq_lock); 440 kn->kn_data = kq->kq_count; 441 rv = (kn->kn_data > 0); 442 if (hint != NOTE_SUBMIT) 443 mutex_spin_exit(&kq->kq_lock); 444 445 return rv; 446 } 447 448 /* 449 * Filter attach method for EVFILT_PROC. 450 */ 451 static int 452 filt_procattach(struct knote *kn) 453 { 454 struct proc *p; 455 struct lwp *curl; 456 457 curl = curlwp; 458 459 mutex_enter(proc_lock); 460 if (kn->kn_flags & EV_FLAG1) { 461 /* 462 * NOTE_TRACK attaches to the child process too early 463 * for proc_find, so do a raw look up and check the state 464 * explicitly. 465 */ 466 p = proc_find_raw(kn->kn_id); 467 if (p != NULL && p->p_stat != SIDL) 468 p = NULL; 469 } else { 470 p = proc_find(kn->kn_id); 471 } 472 473 if (p == NULL) { 474 mutex_exit(proc_lock); 475 return ESRCH; 476 } 477 478 /* 479 * Fail if it's not owned by you, or the last exec gave us 480 * setuid/setgid privs (unless you're root). 481 */ 482 mutex_enter(p->p_lock); 483 mutex_exit(proc_lock); 484 if (kauth_authorize_process(curl->l_cred, KAUTH_PROCESS_KEVENT_FILTER, 485 p, NULL, NULL, NULL) != 0) { 486 mutex_exit(p->p_lock); 487 return EACCES; 488 } 489 490 kn->kn_obj = p; 491 kn->kn_flags |= EV_CLEAR; /* automatically set */ 492 493 /* 494 * internal flag indicating registration done by kernel 495 */ 496 if (kn->kn_flags & EV_FLAG1) { 497 kn->kn_data = kn->kn_sdata; /* ppid */ 498 kn->kn_fflags = NOTE_CHILD; 499 kn->kn_flags &= ~EV_FLAG1; 500 } 501 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 502 mutex_exit(p->p_lock); 503 504 return 0; 505 } 506 507 /* 508 * Filter detach method for EVFILT_PROC. 509 * 510 * The knote may be attached to a different process, which may exit, 511 * leaving nothing for the knote to be attached to. So when the process 512 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 513 * it will be deleted when read out. However, as part of the knote deletion, 514 * this routine is called, so a check is needed to avoid actually performing 515 * a detach, because the original process might not exist any more. 516 */ 517 static void 518 filt_procdetach(struct knote *kn) 519 { 520 struct proc *p; 521 522 if (kn->kn_status & KN_DETACHED) 523 return; 524 525 p = kn->kn_obj; 526 527 mutex_enter(p->p_lock); 528 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 529 mutex_exit(p->p_lock); 530 } 531 532 /* 533 * Filter event method for EVFILT_PROC. 534 */ 535 static int 536 filt_proc(struct knote *kn, long hint) 537 { 538 u_int event, fflag; 539 struct kevent kev; 540 struct kqueue *kq; 541 int error; 542 543 event = (u_int)hint & NOTE_PCTRLMASK; 544 kq = kn->kn_kq; 545 fflag = 0; 546 547 /* If the user is interested in this event, record it. */ 548 if (kn->kn_sfflags & event) 549 fflag |= event; 550 551 if (event == NOTE_EXIT) { 552 struct proc *p = kn->kn_obj; 553 554 if (p != NULL) 555 kn->kn_data = P_WAITSTATUS(p); 556 /* 557 * Process is gone, so flag the event as finished. 558 * 559 * Detach the knote from watched process and mark 560 * it as such. We can't leave this to kqueue_scan(), 561 * since the process might not exist by then. And we 562 * have to do this now, since psignal KNOTE() is called 563 * also for zombies and we might end up reading freed 564 * memory if the kevent would already be picked up 565 * and knote g/c'ed. 566 */ 567 filt_procdetach(kn); 568 569 mutex_spin_enter(&kq->kq_lock); 570 kn->kn_status |= KN_DETACHED; 571 /* Mark as ONESHOT, so that the knote it g/c'ed when read */ 572 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 573 kn->kn_fflags |= fflag; 574 mutex_spin_exit(&kq->kq_lock); 575 576 return 1; 577 } 578 579 mutex_spin_enter(&kq->kq_lock); 580 if ((event == NOTE_FORK) && (kn->kn_sfflags & NOTE_TRACK)) { 581 /* 582 * Process forked, and user wants to track the new process, 583 * so attach a new knote to it, and immediately report an 584 * event with the parent's pid. Register knote with new 585 * process. 586 */ 587 kev.ident = hint & NOTE_PDATAMASK; /* pid */ 588 kev.filter = kn->kn_filter; 589 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 590 kev.fflags = kn->kn_sfflags; 591 kev.data = kn->kn_id; /* parent */ 592 kev.udata = kn->kn_kevent.udata; /* preserve udata */ 593 mutex_spin_exit(&kq->kq_lock); 594 error = kqueue_register(kq, &kev); 595 mutex_spin_enter(&kq->kq_lock); 596 if (error != 0) 597 kn->kn_fflags |= NOTE_TRACKERR; 598 } 599 kn->kn_fflags |= fflag; 600 fflag = kn->kn_fflags; 601 mutex_spin_exit(&kq->kq_lock); 602 603 return fflag != 0; 604 } 605 606 static void 607 filt_timerexpire(void *knx) 608 { 609 struct knote *kn = knx; 610 int tticks; 611 612 mutex_enter(&kqueue_misc_lock); 613 kn->kn_data++; 614 knote_activate(kn); 615 if ((kn->kn_flags & EV_ONESHOT) == 0) { 616 tticks = mstohz(kn->kn_sdata); 617 if (tticks <= 0) 618 tticks = 1; 619 callout_schedule((callout_t *)kn->kn_hook, tticks); 620 } 621 mutex_exit(&kqueue_misc_lock); 622 } 623 624 /* 625 * data contains amount of time to sleep, in milliseconds 626 */ 627 static int 628 filt_timerattach(struct knote *kn) 629 { 630 callout_t *calloutp; 631 struct kqueue *kq; 632 int tticks; 633 634 tticks = mstohz(kn->kn_sdata); 635 636 /* if the supplied value is under our resolution, use 1 tick */ 637 if (tticks == 0) { 638 if (kn->kn_sdata == 0) 639 return EINVAL; 640 tticks = 1; 641 } 642 643 if (atomic_inc_uint_nv(&kq_ncallouts) >= kq_calloutmax || 644 (calloutp = kmem_alloc(sizeof(*calloutp), KM_NOSLEEP)) == NULL) { 645 atomic_dec_uint(&kq_ncallouts); 646 return ENOMEM; 647 } 648 callout_init(calloutp, CALLOUT_MPSAFE); 649 650 kq = kn->kn_kq; 651 mutex_spin_enter(&kq->kq_lock); 652 kn->kn_flags |= EV_CLEAR; /* automatically set */ 653 kn->kn_hook = calloutp; 654 mutex_spin_exit(&kq->kq_lock); 655 656 callout_reset(calloutp, tticks, filt_timerexpire, kn); 657 658 return (0); 659 } 660 661 static void 662 filt_timerdetach(struct knote *kn) 663 { 664 callout_t *calloutp; 665 666 calloutp = (callout_t *)kn->kn_hook; 667 callout_halt(calloutp, NULL); 668 callout_destroy(calloutp); 669 kmem_free(calloutp, sizeof(*calloutp)); 670 atomic_dec_uint(&kq_ncallouts); 671 } 672 673 static int 674 filt_timer(struct knote *kn, long hint) 675 { 676 int rv; 677 678 mutex_enter(&kqueue_misc_lock); 679 rv = (kn->kn_data != 0); 680 mutex_exit(&kqueue_misc_lock); 681 682 return rv; 683 } 684 685 /* 686 * filt_seltrue: 687 * 688 * This filter "event" routine simulates seltrue(). 689 */ 690 int 691 filt_seltrue(struct knote *kn, long hint) 692 { 693 694 /* 695 * We don't know how much data can be read/written, 696 * but we know that it *can* be. This is about as 697 * good as select/poll does as well. 698 */ 699 kn->kn_data = 0; 700 return (1); 701 } 702 703 /* 704 * This provides full kqfilter entry for device switch tables, which 705 * has same effect as filter using filt_seltrue() as filter method. 706 */ 707 static void 708 filt_seltruedetach(struct knote *kn) 709 { 710 /* Nothing to do */ 711 } 712 713 const struct filterops seltrue_filtops = 714 { 1, NULL, filt_seltruedetach, filt_seltrue }; 715 716 int 717 seltrue_kqfilter(dev_t dev, struct knote *kn) 718 { 719 switch (kn->kn_filter) { 720 case EVFILT_READ: 721 case EVFILT_WRITE: 722 kn->kn_fop = &seltrue_filtops; 723 break; 724 default: 725 return (EINVAL); 726 } 727 728 /* Nothing more to do */ 729 return (0); 730 } 731 732 /* 733 * kqueue(2) system call. 734 */ 735 static int 736 kqueue1(struct lwp *l, int flags, register_t *retval) 737 { 738 struct kqueue *kq; 739 file_t *fp; 740 int fd, error; 741 742 if ((error = fd_allocfile(&fp, &fd)) != 0) 743 return error; 744 fp->f_flag = FREAD | FWRITE | (flags & (FNONBLOCK|FNOSIGPIPE)); 745 fp->f_type = DTYPE_KQUEUE; 746 fp->f_ops = &kqueueops; 747 kq = kmem_zalloc(sizeof(*kq), KM_SLEEP); 748 mutex_init(&kq->kq_lock, MUTEX_DEFAULT, IPL_SCHED); 749 cv_init(&kq->kq_cv, "kqueue"); 750 selinit(&kq->kq_sel); 751 TAILQ_INIT(&kq->kq_head); 752 fp->f_kqueue = kq; 753 *retval = fd; 754 kq->kq_fdp = curlwp->l_fd; 755 fd_set_exclose(l, fd, (flags & O_CLOEXEC) != 0); 756 fd_affix(curproc, fp, fd); 757 return error; 758 } 759 760 /* 761 * kqueue(2) system call. 762 */ 763 int 764 sys_kqueue(struct lwp *l, const void *v, register_t *retval) 765 { 766 return kqueue1(l, 0, retval); 767 } 768 769 int 770 sys_kqueue1(struct lwp *l, const struct sys_kqueue1_args *uap, 771 register_t *retval) 772 { 773 /* { 774 syscallarg(int) flags; 775 } */ 776 return kqueue1(l, SCARG(uap, flags), retval); 777 } 778 779 /* 780 * kevent(2) system call. 781 */ 782 int 783 kevent_fetch_changes(void *ctx, const struct kevent *changelist, 784 struct kevent *changes, size_t index, int n) 785 { 786 787 return copyin(changelist + index, changes, n * sizeof(*changes)); 788 } 789 790 int 791 kevent_put_events(void *ctx, struct kevent *events, 792 struct kevent *eventlist, size_t index, int n) 793 { 794 795 return copyout(events, eventlist + index, n * sizeof(*events)); 796 } 797 798 static const struct kevent_ops kevent_native_ops = { 799 .keo_private = NULL, 800 .keo_fetch_timeout = copyin, 801 .keo_fetch_changes = kevent_fetch_changes, 802 .keo_put_events = kevent_put_events, 803 }; 804 805 int 806 sys___kevent50(struct lwp *l, const struct sys___kevent50_args *uap, 807 register_t *retval) 808 { 809 /* { 810 syscallarg(int) fd; 811 syscallarg(const struct kevent *) changelist; 812 syscallarg(size_t) nchanges; 813 syscallarg(struct kevent *) eventlist; 814 syscallarg(size_t) nevents; 815 syscallarg(const struct timespec *) timeout; 816 } */ 817 818 return kevent1(retval, SCARG(uap, fd), SCARG(uap, changelist), 819 SCARG(uap, nchanges), SCARG(uap, eventlist), SCARG(uap, nevents), 820 SCARG(uap, timeout), &kevent_native_ops); 821 } 822 823 int 824 kevent1(register_t *retval, int fd, 825 const struct kevent *changelist, size_t nchanges, 826 struct kevent *eventlist, size_t nevents, 827 const struct timespec *timeout, 828 const struct kevent_ops *keops) 829 { 830 struct kevent *kevp; 831 struct kqueue *kq; 832 struct timespec ts; 833 size_t i, n, ichange; 834 int nerrors, error; 835 struct kevent kevbuf[KQ_NEVENTS]; /* approx 300 bytes on 64-bit */ 836 file_t *fp; 837 838 /* check that we're dealing with a kq */ 839 fp = fd_getfile(fd); 840 if (fp == NULL) 841 return (EBADF); 842 843 if (fp->f_type != DTYPE_KQUEUE) { 844 fd_putfile(fd); 845 return (EBADF); 846 } 847 848 if (timeout != NULL) { 849 error = (*keops->keo_fetch_timeout)(timeout, &ts, sizeof(ts)); 850 if (error) 851 goto done; 852 timeout = &ts; 853 } 854 855 kq = fp->f_kqueue; 856 nerrors = 0; 857 ichange = 0; 858 859 /* traverse list of events to register */ 860 while (nchanges > 0) { 861 n = MIN(nchanges, __arraycount(kevbuf)); 862 error = (*keops->keo_fetch_changes)(keops->keo_private, 863 changelist, kevbuf, ichange, n); 864 if (error) 865 goto done; 866 for (i = 0; i < n; i++) { 867 kevp = &kevbuf[i]; 868 kevp->flags &= ~EV_SYSFLAGS; 869 /* register each knote */ 870 error = kqueue_register(kq, kevp); 871 if (error || (kevp->flags & EV_RECEIPT)) { 872 if (nevents != 0) { 873 kevp->flags = EV_ERROR; 874 kevp->data = error; 875 error = (*keops->keo_put_events) 876 (keops->keo_private, kevp, 877 eventlist, nerrors, 1); 878 if (error) 879 goto done; 880 nevents--; 881 nerrors++; 882 } else { 883 goto done; 884 } 885 } 886 } 887 nchanges -= n; /* update the results */ 888 ichange += n; 889 } 890 if (nerrors) { 891 *retval = nerrors; 892 error = 0; 893 goto done; 894 } 895 896 /* actually scan through the events */ 897 error = kqueue_scan(fp, nevents, eventlist, timeout, retval, keops, 898 kevbuf, __arraycount(kevbuf)); 899 done: 900 fd_putfile(fd); 901 return (error); 902 } 903 904 /* 905 * Register a given kevent kev onto the kqueue 906 */ 907 static int 908 kqueue_register(struct kqueue *kq, struct kevent *kev) 909 { 910 struct kfilter *kfilter; 911 filedesc_t *fdp; 912 file_t *fp; 913 fdfile_t *ff; 914 struct knote *kn, *newkn; 915 struct klist *list; 916 int error, fd, rv; 917 918 fdp = kq->kq_fdp; 919 fp = NULL; 920 kn = NULL; 921 error = 0; 922 fd = 0; 923 924 newkn = kmem_zalloc(sizeof(*newkn), KM_SLEEP); 925 926 rw_enter(&kqueue_filter_lock, RW_READER); 927 kfilter = kfilter_byfilter(kev->filter); 928 if (kfilter == NULL || kfilter->filtops == NULL) { 929 /* filter not found nor implemented */ 930 rw_exit(&kqueue_filter_lock); 931 kmem_free(newkn, sizeof(*newkn)); 932 return (EINVAL); 933 } 934 935 /* search if knote already exists */ 936 if (kfilter->filtops->f_isfd) { 937 /* monitoring a file descriptor */ 938 fd = kev->ident; 939 if ((fp = fd_getfile(fd)) == NULL) { 940 rw_exit(&kqueue_filter_lock); 941 kmem_free(newkn, sizeof(*newkn)); 942 return EBADF; 943 } 944 mutex_enter(&fdp->fd_lock); 945 ff = fdp->fd_dt->dt_ff[fd]; 946 if (fd <= fdp->fd_lastkqfile) { 947 SLIST_FOREACH(kn, &ff->ff_knlist, kn_link) { 948 if (kq == kn->kn_kq && 949 kev->filter == kn->kn_filter) 950 break; 951 } 952 } 953 } else { 954 /* 955 * not monitoring a file descriptor, so 956 * lookup knotes in internal hash table 957 */ 958 mutex_enter(&fdp->fd_lock); 959 if (fdp->fd_knhashmask != 0) { 960 list = &fdp->fd_knhash[ 961 KN_HASH((u_long)kev->ident, fdp->fd_knhashmask)]; 962 SLIST_FOREACH(kn, list, kn_link) { 963 if (kev->ident == kn->kn_id && 964 kq == kn->kn_kq && 965 kev->filter == kn->kn_filter) 966 break; 967 } 968 } 969 } 970 971 /* 972 * kn now contains the matching knote, or NULL if no match 973 */ 974 if (kev->flags & EV_ADD) { 975 if (kn == NULL) { 976 /* create new knote */ 977 kn = newkn; 978 newkn = NULL; 979 kn->kn_obj = fp; 980 kn->kn_id = kev->ident; 981 kn->kn_kq = kq; 982 kn->kn_fop = kfilter->filtops; 983 kn->kn_kfilter = kfilter; 984 kn->kn_sfflags = kev->fflags; 985 kn->kn_sdata = kev->data; 986 kev->fflags = 0; 987 kev->data = 0; 988 kn->kn_kevent = *kev; 989 990 KASSERT(kn->kn_fop != NULL); 991 /* 992 * apply reference count to knote structure, and 993 * do not release it at the end of this routine. 994 */ 995 fp = NULL; 996 997 if (!kn->kn_fop->f_isfd) { 998 /* 999 * If knote is not on an fd, store on 1000 * internal hash table. 1001 */ 1002 if (fdp->fd_knhashmask == 0) { 1003 /* XXXAD can block with fd_lock held */ 1004 fdp->fd_knhash = hashinit(KN_HASHSIZE, 1005 HASH_LIST, true, 1006 &fdp->fd_knhashmask); 1007 } 1008 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, 1009 fdp->fd_knhashmask)]; 1010 } else { 1011 /* Otherwise, knote is on an fd. */ 1012 list = (struct klist *) 1013 &fdp->fd_dt->dt_ff[kn->kn_id]->ff_knlist; 1014 if ((int)kn->kn_id > fdp->fd_lastkqfile) 1015 fdp->fd_lastkqfile = kn->kn_id; 1016 } 1017 SLIST_INSERT_HEAD(list, kn, kn_link); 1018 1019 KERNEL_LOCK(1, NULL); /* XXXSMP */ 1020 error = (*kfilter->filtops->f_attach)(kn); 1021 KERNEL_UNLOCK_ONE(NULL); /* XXXSMP */ 1022 if (error != 0) { 1023 #ifdef DIAGNOSTIC 1024 printf("%s: event not supported for file type" 1025 " %d\n", __func__, fp ? fp->f_type : -1); 1026 #endif 1027 /* knote_detach() drops fdp->fd_lock */ 1028 knote_detach(kn, fdp, false); 1029 goto done; 1030 } 1031 atomic_inc_uint(&kfilter->refcnt); 1032 } else { 1033 /* 1034 * The user may change some filter values after the 1035 * initial EV_ADD, but doing so will not reset any 1036 * filter which have already been triggered. 1037 */ 1038 kn->kn_sfflags = kev->fflags; 1039 kn->kn_sdata = kev->data; 1040 kn->kn_kevent.udata = kev->udata; 1041 } 1042 /* 1043 * We can get here if we are trying to attach 1044 * an event to a file descriptor that does not 1045 * support events, and the attach routine is 1046 * broken and does not return an error. 1047 */ 1048 KASSERT(kn->kn_fop != NULL); 1049 KASSERT(kn->kn_fop->f_event != NULL); 1050 KERNEL_LOCK(1, NULL); /* XXXSMP */ 1051 rv = (*kn->kn_fop->f_event)(kn, 0); 1052 KERNEL_UNLOCK_ONE(NULL); /* XXXSMP */ 1053 if (rv) 1054 knote_activate(kn); 1055 } else { 1056 if (kn == NULL) { 1057 error = ENOENT; 1058 mutex_exit(&fdp->fd_lock); 1059 goto done; 1060 } 1061 if (kev->flags & EV_DELETE) { 1062 /* knote_detach() drops fdp->fd_lock */ 1063 knote_detach(kn, fdp, true); 1064 goto done; 1065 } 1066 } 1067 1068 /* disable knote */ 1069 if ((kev->flags & EV_DISABLE)) { 1070 mutex_spin_enter(&kq->kq_lock); 1071 if ((kn->kn_status & KN_DISABLED) == 0) 1072 kn->kn_status |= KN_DISABLED; 1073 mutex_spin_exit(&kq->kq_lock); 1074 } 1075 1076 /* enable knote */ 1077 if ((kev->flags & EV_ENABLE)) { 1078 knote_enqueue(kn); 1079 } 1080 mutex_exit(&fdp->fd_lock); 1081 done: 1082 rw_exit(&kqueue_filter_lock); 1083 if (newkn != NULL) 1084 kmem_free(newkn, sizeof(*newkn)); 1085 if (fp != NULL) 1086 fd_putfile(fd); 1087 return (error); 1088 } 1089 1090 #if defined(DEBUG) 1091 static void 1092 kq_check(struct kqueue *kq) 1093 { 1094 const struct knote *kn; 1095 int count; 1096 int nmarker; 1097 1098 KASSERT(mutex_owned(&kq->kq_lock)); 1099 KASSERT(kq->kq_count >= 0); 1100 1101 count = 0; 1102 nmarker = 0; 1103 TAILQ_FOREACH(kn, &kq->kq_head, kn_tqe) { 1104 if ((kn->kn_status & (KN_MARKER | KN_QUEUED)) == 0) { 1105 panic("%s: kq=%p kn=%p inconsist 1", __func__, kq, kn); 1106 } 1107 if ((kn->kn_status & KN_MARKER) == 0) { 1108 if (kn->kn_kq != kq) { 1109 panic("%s: kq=%p kn=%p inconsist 2", 1110 __func__, kq, kn); 1111 } 1112 if ((kn->kn_status & KN_ACTIVE) == 0) { 1113 panic("%s: kq=%p kn=%p: not active", 1114 __func__, kq, kn); 1115 } 1116 count++; 1117 if (count > kq->kq_count) { 1118 goto bad; 1119 } 1120 } else { 1121 nmarker++; 1122 #if 0 1123 if (nmarker > 10000) { 1124 panic("%s: kq=%p too many markers: %d != %d, " 1125 "nmarker=%d", 1126 __func__, kq, kq->kq_count, count, nmarker); 1127 } 1128 #endif 1129 } 1130 } 1131 if (kq->kq_count != count) { 1132 bad: 1133 panic("%s: kq=%p inconsist 3: %d != %d, nmarker=%d", 1134 __func__, kq, kq->kq_count, count, nmarker); 1135 } 1136 } 1137 #else /* defined(DEBUG) */ 1138 #define kq_check(a) /* nothing */ 1139 #endif /* defined(DEBUG) */ 1140 1141 /* 1142 * Scan through the list of events on fp (for a maximum of maxevents), 1143 * returning the results in to ulistp. Timeout is determined by tsp; if 1144 * NULL, wait indefinitely, if 0 valued, perform a poll, otherwise wait 1145 * as appropriate. 1146 */ 1147 static int 1148 kqueue_scan(file_t *fp, size_t maxevents, struct kevent *ulistp, 1149 const struct timespec *tsp, register_t *retval, 1150 const struct kevent_ops *keops, struct kevent *kevbuf, 1151 size_t kevcnt) 1152 { 1153 struct kqueue *kq; 1154 struct kevent *kevp; 1155 struct timespec ats, sleepts; 1156 struct knote *kn, *marker, morker; 1157 size_t count, nkev, nevents; 1158 int timeout, error, rv; 1159 filedesc_t *fdp; 1160 1161 fdp = curlwp->l_fd; 1162 kq = fp->f_kqueue; 1163 count = maxevents; 1164 nkev = nevents = error = 0; 1165 if (count == 0) { 1166 *retval = 0; 1167 return 0; 1168 } 1169 1170 if (tsp) { /* timeout supplied */ 1171 ats = *tsp; 1172 if (inittimeleft(&ats, &sleepts) == -1) { 1173 *retval = maxevents; 1174 return EINVAL; 1175 } 1176 timeout = tstohz(&ats); 1177 if (timeout <= 0) 1178 timeout = -1; /* do poll */ 1179 } else { 1180 /* no timeout, wait forever */ 1181 timeout = 0; 1182 } 1183 1184 memset(&morker, 0, sizeof(morker)); 1185 marker = &morker; 1186 marker->kn_status = KN_MARKER; 1187 mutex_spin_enter(&kq->kq_lock); 1188 retry: 1189 kevp = kevbuf; 1190 if (kq->kq_count == 0) { 1191 if (timeout >= 0) { 1192 error = cv_timedwait_sig(&kq->kq_cv, 1193 &kq->kq_lock, timeout); 1194 if (error == 0) { 1195 if (tsp == NULL || (timeout = 1196 gettimeleft(&ats, &sleepts)) > 0) 1197 goto retry; 1198 } else { 1199 /* don't restart after signals... */ 1200 if (error == ERESTART) 1201 error = EINTR; 1202 if (error == EWOULDBLOCK) 1203 error = 0; 1204 } 1205 } 1206 } else { 1207 /* mark end of knote list */ 1208 TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); 1209 1210 while (count != 0) { 1211 kn = TAILQ_FIRST(&kq->kq_head); /* get next knote */ 1212 while ((kn->kn_status & KN_MARKER) != 0) { 1213 if (kn == marker) { 1214 /* it's our marker, stop */ 1215 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1216 if (count < maxevents || (tsp != NULL && 1217 (timeout = gettimeleft(&ats, 1218 &sleepts)) <= 0)) 1219 goto done; 1220 goto retry; 1221 } 1222 /* someone else's marker. */ 1223 kn = TAILQ_NEXT(kn, kn_tqe); 1224 } 1225 kq_check(kq); 1226 kq->kq_count--; 1227 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1228 kn->kn_status &= ~KN_QUEUED; 1229 kn->kn_status |= KN_BUSY; 1230 kq_check(kq); 1231 if (kn->kn_status & KN_DISABLED) { 1232 kn->kn_status &= ~KN_BUSY; 1233 /* don't want disabled events */ 1234 continue; 1235 } 1236 if ((kn->kn_flags & EV_ONESHOT) == 0) { 1237 mutex_spin_exit(&kq->kq_lock); 1238 KASSERT(kn->kn_fop != NULL); 1239 KASSERT(kn->kn_fop->f_event != NULL); 1240 KERNEL_LOCK(1, NULL); /* XXXSMP */ 1241 rv = (*kn->kn_fop->f_event)(kn, 0); 1242 KERNEL_UNLOCK_ONE(NULL); /* XXXSMP */ 1243 mutex_spin_enter(&kq->kq_lock); 1244 /* Re-poll if note was re-enqueued. */ 1245 if ((kn->kn_status & KN_QUEUED) != 0) { 1246 kn->kn_status &= ~KN_BUSY; 1247 continue; 1248 } 1249 if (rv == 0) { 1250 /* 1251 * non-ONESHOT event that hasn't 1252 * triggered again, so de-queue. 1253 */ 1254 kn->kn_status &= ~(KN_ACTIVE|KN_BUSY); 1255 continue; 1256 } 1257 } 1258 /* XXXAD should be got from f_event if !oneshot. */ 1259 *kevp++ = kn->kn_kevent; 1260 nkev++; 1261 if (kn->kn_flags & EV_ONESHOT) { 1262 /* delete ONESHOT events after retrieval */ 1263 mutex_spin_exit(&kq->kq_lock); 1264 mutex_enter(&fdp->fd_lock); 1265 kn->kn_status &= ~KN_BUSY; 1266 knote_detach(kn, fdp, true); 1267 mutex_spin_enter(&kq->kq_lock); 1268 } else if (kn->kn_flags & EV_CLEAR) { 1269 /* clear state after retrieval */ 1270 kn->kn_data = 0; 1271 kn->kn_fflags = 0; 1272 kn->kn_status &= ~(KN_QUEUED|KN_ACTIVE|KN_BUSY); 1273 } else if (kn->kn_flags & EV_DISPATCH) { 1274 kn->kn_status |= KN_DISABLED; 1275 kn->kn_status &= ~(KN_QUEUED|KN_ACTIVE|KN_BUSY); 1276 } else { 1277 /* add event back on list */ 1278 kq_check(kq); 1279 kn->kn_status |= KN_QUEUED; 1280 kn->kn_status &= ~KN_BUSY; 1281 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 1282 kq->kq_count++; 1283 kq_check(kq); 1284 } 1285 if (nkev == kevcnt) { 1286 /* do copyouts in kevcnt chunks */ 1287 mutex_spin_exit(&kq->kq_lock); 1288 error = (*keops->keo_put_events) 1289 (keops->keo_private, 1290 kevbuf, ulistp, nevents, nkev); 1291 mutex_spin_enter(&kq->kq_lock); 1292 nevents += nkev; 1293 nkev = 0; 1294 kevp = kevbuf; 1295 } 1296 count--; 1297 if (error != 0 || count == 0) { 1298 /* remove marker */ 1299 TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); 1300 break; 1301 } 1302 } 1303 } 1304 done: 1305 mutex_spin_exit(&kq->kq_lock); 1306 if (nkev != 0) { 1307 /* copyout remaining events */ 1308 error = (*keops->keo_put_events)(keops->keo_private, 1309 kevbuf, ulistp, nevents, nkev); 1310 } 1311 *retval = maxevents - count; 1312 1313 return error; 1314 } 1315 1316 /* 1317 * fileops ioctl method for a kqueue descriptor. 1318 * 1319 * Two ioctls are currently supported. They both use struct kfilter_mapping: 1320 * KFILTER_BYNAME find name for filter, and return result in 1321 * name, which is of size len. 1322 * KFILTER_BYFILTER find filter for name. len is ignored. 1323 */ 1324 /*ARGSUSED*/ 1325 static int 1326 kqueue_ioctl(file_t *fp, u_long com, void *data) 1327 { 1328 struct kfilter_mapping *km; 1329 const struct kfilter *kfilter; 1330 char *name; 1331 int error; 1332 1333 km = data; 1334 error = 0; 1335 name = kmem_alloc(KFILTER_MAXNAME, KM_SLEEP); 1336 1337 switch (com) { 1338 case KFILTER_BYFILTER: /* convert filter -> name */ 1339 rw_enter(&kqueue_filter_lock, RW_READER); 1340 kfilter = kfilter_byfilter(km->filter); 1341 if (kfilter != NULL) { 1342 strlcpy(name, kfilter->name, KFILTER_MAXNAME); 1343 rw_exit(&kqueue_filter_lock); 1344 error = copyoutstr(name, km->name, km->len, NULL); 1345 } else { 1346 rw_exit(&kqueue_filter_lock); 1347 error = ENOENT; 1348 } 1349 break; 1350 1351 case KFILTER_BYNAME: /* convert name -> filter */ 1352 error = copyinstr(km->name, name, KFILTER_MAXNAME, NULL); 1353 if (error) { 1354 break; 1355 } 1356 rw_enter(&kqueue_filter_lock, RW_READER); 1357 kfilter = kfilter_byname(name); 1358 if (kfilter != NULL) 1359 km->filter = kfilter->filter; 1360 else 1361 error = ENOENT; 1362 rw_exit(&kqueue_filter_lock); 1363 break; 1364 1365 default: 1366 error = ENOTTY; 1367 break; 1368 1369 } 1370 kmem_free(name, KFILTER_MAXNAME); 1371 return (error); 1372 } 1373 1374 /* 1375 * fileops fcntl method for a kqueue descriptor. 1376 */ 1377 static int 1378 kqueue_fcntl(file_t *fp, u_int com, void *data) 1379 { 1380 1381 return (ENOTTY); 1382 } 1383 1384 /* 1385 * fileops poll method for a kqueue descriptor. 1386 * Determine if kqueue has events pending. 1387 */ 1388 static int 1389 kqueue_poll(file_t *fp, int events) 1390 { 1391 struct kqueue *kq; 1392 int revents; 1393 1394 kq = fp->f_kqueue; 1395 1396 revents = 0; 1397 if (events & (POLLIN | POLLRDNORM)) { 1398 mutex_spin_enter(&kq->kq_lock); 1399 if (kq->kq_count != 0) { 1400 revents |= events & (POLLIN | POLLRDNORM); 1401 } else { 1402 selrecord(curlwp, &kq->kq_sel); 1403 } 1404 kq_check(kq); 1405 mutex_spin_exit(&kq->kq_lock); 1406 } 1407 1408 return revents; 1409 } 1410 1411 /* 1412 * fileops stat method for a kqueue descriptor. 1413 * Returns dummy info, with st_size being number of events pending. 1414 */ 1415 static int 1416 kqueue_stat(file_t *fp, struct stat *st) 1417 { 1418 struct kqueue *kq; 1419 1420 kq = fp->f_kqueue; 1421 1422 memset(st, 0, sizeof(*st)); 1423 st->st_size = kq->kq_count; 1424 st->st_blksize = sizeof(struct kevent); 1425 st->st_mode = S_IFIFO; 1426 1427 return 0; 1428 } 1429 1430 static void 1431 kqueue_doclose(struct kqueue *kq, struct klist *list, int fd) 1432 { 1433 struct knote *kn; 1434 filedesc_t *fdp; 1435 1436 fdp = kq->kq_fdp; 1437 1438 KASSERT(mutex_owned(&fdp->fd_lock)); 1439 1440 for (kn = SLIST_FIRST(list); kn != NULL;) { 1441 if (kq != kn->kn_kq) { 1442 kn = SLIST_NEXT(kn, kn_link); 1443 continue; 1444 } 1445 knote_detach(kn, fdp, true); 1446 mutex_enter(&fdp->fd_lock); 1447 kn = SLIST_FIRST(list); 1448 } 1449 } 1450 1451 1452 /* 1453 * fileops close method for a kqueue descriptor. 1454 */ 1455 static int 1456 kqueue_close(file_t *fp) 1457 { 1458 struct kqueue *kq; 1459 filedesc_t *fdp; 1460 fdfile_t *ff; 1461 int i; 1462 1463 kq = fp->f_kqueue; 1464 fp->f_kqueue = NULL; 1465 fp->f_type = 0; 1466 fdp = curlwp->l_fd; 1467 1468 mutex_enter(&fdp->fd_lock); 1469 for (i = 0; i <= fdp->fd_lastkqfile; i++) { 1470 if ((ff = fdp->fd_dt->dt_ff[i]) == NULL) 1471 continue; 1472 kqueue_doclose(kq, (struct klist *)&ff->ff_knlist, i); 1473 } 1474 if (fdp->fd_knhashmask != 0) { 1475 for (i = 0; i < fdp->fd_knhashmask + 1; i++) { 1476 kqueue_doclose(kq, &fdp->fd_knhash[i], -1); 1477 } 1478 } 1479 mutex_exit(&fdp->fd_lock); 1480 1481 KASSERT(kq->kq_count == 0); 1482 mutex_destroy(&kq->kq_lock); 1483 cv_destroy(&kq->kq_cv); 1484 seldestroy(&kq->kq_sel); 1485 kmem_free(kq, sizeof(*kq)); 1486 1487 return (0); 1488 } 1489 1490 /* 1491 * struct fileops kqfilter method for a kqueue descriptor. 1492 * Event triggered when monitored kqueue changes. 1493 */ 1494 static int 1495 kqueue_kqfilter(file_t *fp, struct knote *kn) 1496 { 1497 struct kqueue *kq; 1498 1499 kq = ((file_t *)kn->kn_obj)->f_kqueue; 1500 1501 KASSERT(fp == kn->kn_obj); 1502 1503 if (kn->kn_filter != EVFILT_READ) 1504 return 1; 1505 1506 kn->kn_fop = &kqread_filtops; 1507 mutex_enter(&kq->kq_lock); 1508 SLIST_INSERT_HEAD(&kq->kq_sel.sel_klist, kn, kn_selnext); 1509 mutex_exit(&kq->kq_lock); 1510 1511 return 0; 1512 } 1513 1514 1515 /* 1516 * Walk down a list of knotes, activating them if their event has 1517 * triggered. The caller's object lock (e.g. device driver lock) 1518 * must be held. 1519 */ 1520 void 1521 knote(struct klist *list, long hint) 1522 { 1523 struct knote *kn, *tmpkn; 1524 1525 SLIST_FOREACH_SAFE(kn, list, kn_selnext, tmpkn) { 1526 KASSERT(kn->kn_fop != NULL); 1527 KASSERT(kn->kn_fop->f_event != NULL); 1528 if ((*kn->kn_fop->f_event)(kn, hint)) 1529 knote_activate(kn); 1530 } 1531 } 1532 1533 /* 1534 * Remove all knotes referencing a specified fd 1535 */ 1536 void 1537 knote_fdclose(int fd) 1538 { 1539 struct klist *list; 1540 struct knote *kn; 1541 filedesc_t *fdp; 1542 1543 fdp = curlwp->l_fd; 1544 list = (struct klist *)&fdp->fd_dt->dt_ff[fd]->ff_knlist; 1545 mutex_enter(&fdp->fd_lock); 1546 while ((kn = SLIST_FIRST(list)) != NULL) { 1547 knote_detach(kn, fdp, true); 1548 mutex_enter(&fdp->fd_lock); 1549 } 1550 mutex_exit(&fdp->fd_lock); 1551 } 1552 1553 /* 1554 * Drop knote. Called with fdp->fd_lock held, and will drop before 1555 * returning. 1556 */ 1557 static void 1558 knote_detach(struct knote *kn, filedesc_t *fdp, bool dofop) 1559 { 1560 struct klist *list; 1561 struct kqueue *kq; 1562 1563 kq = kn->kn_kq; 1564 1565 KASSERT((kn->kn_status & KN_MARKER) == 0); 1566 KASSERT(mutex_owned(&fdp->fd_lock)); 1567 1568 KASSERT(kn->kn_fop != NULL); 1569 /* Remove from monitored object. */ 1570 if (dofop) { 1571 KASSERT(kn->kn_fop->f_detach != NULL); 1572 KERNEL_LOCK(1, NULL); /* XXXSMP */ 1573 (*kn->kn_fop->f_detach)(kn); 1574 KERNEL_UNLOCK_ONE(NULL); /* XXXSMP */ 1575 } 1576 1577 /* Remove from descriptor table. */ 1578 if (kn->kn_fop->f_isfd) 1579 list = (struct klist *)&fdp->fd_dt->dt_ff[kn->kn_id]->ff_knlist; 1580 else 1581 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; 1582 1583 SLIST_REMOVE(list, kn, knote, kn_link); 1584 1585 /* Remove from kqueue. */ 1586 again: 1587 mutex_spin_enter(&kq->kq_lock); 1588 if ((kn->kn_status & KN_QUEUED) != 0) { 1589 kq_check(kq); 1590 kq->kq_count--; 1591 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 1592 kn->kn_status &= ~KN_QUEUED; 1593 kq_check(kq); 1594 } else if (kn->kn_status & KN_BUSY) { 1595 mutex_spin_exit(&kq->kq_lock); 1596 goto again; 1597 } 1598 mutex_spin_exit(&kq->kq_lock); 1599 1600 mutex_exit(&fdp->fd_lock); 1601 if (kn->kn_fop->f_isfd) 1602 fd_putfile(kn->kn_id); 1603 atomic_dec_uint(&kn->kn_kfilter->refcnt); 1604 kmem_free(kn, sizeof(*kn)); 1605 } 1606 1607 /* 1608 * Queue new event for knote. 1609 */ 1610 static void 1611 knote_enqueue(struct knote *kn) 1612 { 1613 struct kqueue *kq; 1614 1615 KASSERT((kn->kn_status & KN_MARKER) == 0); 1616 1617 kq = kn->kn_kq; 1618 1619 mutex_spin_enter(&kq->kq_lock); 1620 if ((kn->kn_status & KN_DISABLED) != 0) { 1621 kn->kn_status &= ~KN_DISABLED; 1622 } 1623 if ((kn->kn_status & (KN_ACTIVE | KN_QUEUED)) == KN_ACTIVE) { 1624 kq_check(kq); 1625 kn->kn_status |= KN_QUEUED; 1626 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 1627 kq->kq_count++; 1628 kq_check(kq); 1629 cv_broadcast(&kq->kq_cv); 1630 selnotify(&kq->kq_sel, 0, NOTE_SUBMIT); 1631 } 1632 mutex_spin_exit(&kq->kq_lock); 1633 } 1634 /* 1635 * Queue new event for knote. 1636 */ 1637 static void 1638 knote_activate(struct knote *kn) 1639 { 1640 struct kqueue *kq; 1641 1642 KASSERT((kn->kn_status & KN_MARKER) == 0); 1643 1644 kq = kn->kn_kq; 1645 1646 mutex_spin_enter(&kq->kq_lock); 1647 kn->kn_status |= KN_ACTIVE; 1648 if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) { 1649 kq_check(kq); 1650 kn->kn_status |= KN_QUEUED; 1651 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 1652 kq->kq_count++; 1653 kq_check(kq); 1654 cv_broadcast(&kq->kq_cv); 1655 selnotify(&kq->kq_sel, 0, NOTE_SUBMIT); 1656 } 1657 mutex_spin_exit(&kq->kq_lock); 1658 } 1659