1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org> 5 * Copyright 2004 John-Mark Gurney <jmg@FreeBSD.org> 6 * Copyright (c) 2009 Apple, Inc. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include "opt_ktrace.h" 32 #include "opt_kqueue.h" 33 34 #ifdef COMPAT_FREEBSD11 35 #define _WANT_FREEBSD11_KEVENT 36 #endif 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/capsicum.h> 41 #include <sys/kernel.h> 42 #include <sys/limits.h> 43 #include <sys/lock.h> 44 #include <sys/mutex.h> 45 #include <sys/proc.h> 46 #include <sys/malloc.h> 47 #include <sys/unistd.h> 48 #include <sys/file.h> 49 #include <sys/filedesc.h> 50 #include <sys/filio.h> 51 #include <sys/fcntl.h> 52 #include <sys/imgact.h> 53 #include <sys/jail.h> 54 #include <sys/jaildesc.h> 55 #include <sys/kthread.h> 56 #include <sys/selinfo.h> 57 #include <sys/queue.h> 58 #include <sys/event.h> 59 #include <sys/eventvar.h> 60 #include <sys/poll.h> 61 #include <sys/protosw.h> 62 #include <sys/resourcevar.h> 63 #include <sys/sbuf.h> 64 #include <sys/sigio.h> 65 #include <sys/signalvar.h> 66 #include <sys/socket.h> 67 #include <sys/socketvar.h> 68 #include <sys/stat.h> 69 #include <sys/sysctl.h> 70 #include <sys/sysent.h> 71 #include <sys/sysproto.h> 72 #include <sys/syscallsubr.h> 73 #include <sys/taskqueue.h> 74 #include <sys/uio.h> 75 #include <sys/user.h> 76 #ifdef KTRACE 77 #include <sys/ktrace.h> 78 #endif 79 #include <machine/atomic.h> 80 #ifdef COMPAT_FREEBSD32 81 #include <compat/freebsd32/freebsd32.h> 82 #include <compat/freebsd32/freebsd32_util.h> 83 #endif 84 85 #include <vm/uma.h> 86 87 static MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system"); 88 89 /* 90 * This lock is used if multiple kq locks are required. This possibly 91 * should be made into a per proc lock. 92 */ 93 static struct mtx kq_global; 94 MTX_SYSINIT(kq_global, &kq_global, "kqueue order", MTX_DEF); 95 #define KQ_GLOBAL_LOCK(lck, haslck) do { \ 96 if (!haslck) \ 97 mtx_lock(lck); \ 98 haslck = 1; \ 99 } while (0) 100 #define KQ_GLOBAL_UNLOCK(lck, haslck) do { \ 101 if (haslck) \ 102 mtx_unlock(lck); \ 103 haslck = 0; \ 104 } while (0) 105 106 TASKQUEUE_DEFINE_THREAD(kqueue_ctx); 107 108 static int kevent_copyout(void *arg, struct kevent *kevp, int count); 109 static int kevent_copyin(void *arg, struct kevent *kevp, int count); 110 static int kqueue_register(struct kqueue *kq, struct kevent *kev, 111 struct thread *td, int mflag); 112 static int kqueue_acquire(struct file *fp, struct kqueue **kqp); 113 static void kqueue_release(struct kqueue *kq, int locked); 114 static void kqueue_destroy(struct kqueue *kq); 115 static void kqueue_drain(struct kqueue *kq, struct thread *td); 116 static int kqueue_expand(struct kqueue *kq, const struct filterops *fops, 117 uintptr_t ident, int mflag); 118 static void kqueue_task(void *arg, int pending); 119 static int kqueue_scan(struct kqueue *kq, int maxevents, 120 struct kevent_copyops *k_ops, 121 const struct timespec *timeout, 122 struct kevent *keva, struct thread *td); 123 static void kqueue_wakeup(struct kqueue *kq); 124 static const struct filterops *kqueue_fo_find(int filt); 125 static void kqueue_fo_release(int filt); 126 struct g_kevent_args; 127 static int kern_kevent_generic(struct thread *td, 128 struct g_kevent_args *uap, 129 struct kevent_copyops *k_ops, const char *struct_name); 130 131 static fo_ioctl_t kqueue_ioctl; 132 static fo_poll_t kqueue_poll; 133 static fo_kqfilter_t kqueue_kqfilter; 134 static fo_stat_t kqueue_stat; 135 static fo_close_t kqueue_close; 136 static fo_fill_kinfo_t kqueue_fill_kinfo; 137 static fo_fork_t kqueue_fork; 138 139 static const struct fileops kqueueops = { 140 .fo_read = invfo_rdwr, 141 .fo_write = invfo_rdwr, 142 .fo_truncate = invfo_truncate, 143 .fo_ioctl = kqueue_ioctl, 144 .fo_poll = kqueue_poll, 145 .fo_kqfilter = kqueue_kqfilter, 146 .fo_stat = kqueue_stat, 147 .fo_close = kqueue_close, 148 .fo_chmod = invfo_chmod, 149 .fo_chown = invfo_chown, 150 .fo_sendfile = invfo_sendfile, 151 .fo_cmp = file_kcmp_generic, 152 .fo_fork = kqueue_fork, 153 .fo_fill_kinfo = kqueue_fill_kinfo, 154 .fo_flags = DFLAG_FORK, 155 }; 156 157 static int knote_attach(struct knote *kn, struct kqueue *kq); 158 static void knote_drop(struct knote *kn, struct thread *td); 159 static void knote_drop_detached(struct knote *kn, struct thread *td); 160 static void knote_enqueue(struct knote *kn); 161 static void knote_dequeue(struct knote *kn); 162 static void knote_init(void *); 163 static struct knote *knote_alloc(int mflag); 164 static void knote_free(struct knote *kn); 165 166 static void filt_kqdetach(struct knote *kn); 167 static int filt_kqueue(struct knote *kn, long hint); 168 static int filt_procattach(struct knote *kn); 169 static void filt_procdetach(struct knote *kn); 170 static int filt_proc(struct knote *kn, long hint); 171 static int filt_jailattach(struct knote *kn); 172 static void filt_jaildetach(struct knote *kn); 173 static int filt_jail(struct knote *kn, long hint); 174 static int filt_fileattach(struct knote *kn); 175 static void filt_timerexpire(void *knx); 176 static void filt_timerexpire_l(struct knote *kn, bool proc_locked); 177 static int filt_timerattach(struct knote *kn); 178 static void filt_timerdetach(struct knote *kn); 179 static void filt_timerstart(struct knote *kn, sbintime_t to); 180 static void filt_timertouch(struct knote *kn, struct kevent *kev, 181 u_long type); 182 static int filt_timercopy(struct knote *kn, struct proc *p1); 183 static int filt_timervalidate(struct knote *kn, sbintime_t *to); 184 static int filt_timer(struct knote *kn, long hint); 185 static int filt_userattach(struct knote *kn); 186 static void filt_userdetach(struct knote *kn); 187 static int filt_user(struct knote *kn, long hint); 188 static void filt_usertouch(struct knote *kn, struct kevent *kev, 189 u_long type); 190 191 static const struct filterops file_filtops = { 192 .f_isfd = 1, 193 .f_attach = filt_fileattach, 194 .f_copy = knote_triv_copy, 195 }; 196 static const struct filterops kqread_filtops = { 197 .f_isfd = 1, 198 .f_detach = filt_kqdetach, 199 .f_event = filt_kqueue, 200 .f_copy = knote_triv_copy, 201 }; 202 /* XXX - move to kern_proc.c? */ 203 static const struct filterops proc_filtops = { 204 .f_isfd = 0, 205 .f_attach = filt_procattach, 206 .f_detach = filt_procdetach, 207 .f_event = filt_proc, 208 .f_copy = knote_triv_copy, 209 }; 210 static const struct filterops jail_filtops = { 211 .f_isfd = 0, 212 .f_attach = filt_jailattach, 213 .f_detach = filt_jaildetach, 214 .f_event = filt_jail, 215 .f_copy = knote_triv_copy, 216 }; 217 static const struct filterops timer_filtops = { 218 .f_isfd = 0, 219 .f_attach = filt_timerattach, 220 .f_detach = filt_timerdetach, 221 .f_event = filt_timer, 222 .f_touch = filt_timertouch, 223 .f_copy = filt_timercopy, 224 }; 225 static const struct filterops user_filtops = { 226 .f_attach = filt_userattach, 227 .f_detach = filt_userdetach, 228 .f_event = filt_user, 229 .f_touch = filt_usertouch, 230 .f_copy = knote_triv_copy, 231 }; 232 233 static uma_zone_t knote_zone; 234 static unsigned int __exclusive_cache_line kq_ncallouts; 235 static unsigned int kq_calloutmax = 4 * 1024; 236 SYSCTL_UINT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW, 237 &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue"); 238 239 /* XXX - ensure not influx ? */ 240 #define KNOTE_ACTIVATE(kn, islock) do { \ 241 if ((islock)) \ 242 mtx_assert(&(kn)->kn_kq->kq_lock, MA_OWNED); \ 243 else \ 244 KQ_LOCK((kn)->kn_kq); \ 245 (kn)->kn_status |= KN_ACTIVE; \ 246 if (((kn)->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 247 knote_enqueue((kn)); \ 248 if (!(islock)) \ 249 KQ_UNLOCK((kn)->kn_kq); \ 250 } while (0) 251 #define KQ_LOCK(kq) do { \ 252 mtx_lock(&(kq)->kq_lock); \ 253 } while (0) 254 #define KQ_FLUX_WAKEUP(kq) do { \ 255 if (((kq)->kq_state & KQ_FLUXWAIT) == KQ_FLUXWAIT) { \ 256 (kq)->kq_state &= ~KQ_FLUXWAIT; \ 257 wakeup((kq)); \ 258 } \ 259 } while (0) 260 #define KQ_FLUX_SLEEP_WMESG(kq, kn, flags, wmesg) do { \ 261 KASSERT((kn)->kn_kq == (kq), \ 262 ("%s: knote %p not on kqueue %p", __func__, kn, kq)); \ 263 (kq)->kq_state |= KQ_FLUXWAIT; \ 264 msleep((kq), &(kq)->kq_lock, PSOCK | (flags), (wmesg), 0); \ 265 } while (0) 266 #define KQ_FLUX_SLEEP(kq, kn, flags) \ 267 KQ_FLUX_SLEEP_WMESG(kq, kn, flags, "kqfluxwt") 268 #define KQ_UNLOCK_FLUX(kq) do { \ 269 KQ_FLUX_WAKEUP(kq); \ 270 mtx_unlock(&(kq)->kq_lock); \ 271 } while (0) 272 #define KQ_UNLOCK(kq) do { \ 273 mtx_unlock(&(kq)->kq_lock); \ 274 } while (0) 275 #define KQ_OWNED(kq) do { \ 276 mtx_assert(&(kq)->kq_lock, MA_OWNED); \ 277 } while (0) 278 #define KQ_NOTOWNED(kq) do { \ 279 mtx_assert(&(kq)->kq_lock, MA_NOTOWNED); \ 280 } while (0) 281 282 static struct knlist * 283 kn_list_lock(struct knote *kn) 284 { 285 struct knlist *knl; 286 287 knl = kn->kn_knlist; 288 if (knl != NULL) 289 knl->kl_lock(knl->kl_lockarg); 290 return (knl); 291 } 292 293 static void 294 kn_list_unlock(struct knlist *knl) 295 { 296 bool do_free; 297 298 if (knl == NULL) 299 return; 300 do_free = knl->kl_autodestroy && knlist_empty(knl); 301 knl->kl_unlock(knl->kl_lockarg); 302 if (do_free) { 303 knlist_destroy(knl); 304 free(knl, M_KQUEUE); 305 } 306 } 307 308 static bool 309 kn_in_flux(struct knote *kn) 310 { 311 312 return (kn->kn_influx > 0); 313 } 314 315 static void 316 kn_enter_flux(struct knote *kn) 317 { 318 319 KQ_OWNED(kn->kn_kq); 320 MPASS(kn->kn_influx < INT_MAX); 321 kn->kn_influx++; 322 } 323 324 static bool 325 kn_leave_flux(struct knote *kn) 326 { 327 328 KQ_OWNED(kn->kn_kq); 329 MPASS(kn->kn_influx > 0); 330 kn->kn_influx--; 331 return (kn->kn_influx == 0); 332 } 333 334 #define KNL_ASSERT_LOCK(knl, islocked) do { \ 335 if (islocked) \ 336 KNL_ASSERT_LOCKED(knl); \ 337 else \ 338 KNL_ASSERT_UNLOCKED(knl); \ 339 } while (0) 340 #ifdef INVARIANTS 341 #define KNL_ASSERT_LOCKED(knl) do { \ 342 knl->kl_assert_lock((knl)->kl_lockarg, LA_LOCKED); \ 343 } while (0) 344 #define KNL_ASSERT_UNLOCKED(knl) do { \ 345 knl->kl_assert_lock((knl)->kl_lockarg, LA_UNLOCKED); \ 346 } while (0) 347 #else /* !INVARIANTS */ 348 #define KNL_ASSERT_LOCKED(knl) do {} while (0) 349 #define KNL_ASSERT_UNLOCKED(knl) do {} while (0) 350 #endif /* INVARIANTS */ 351 352 #ifndef KN_HASHSIZE 353 #define KN_HASHSIZE 64 /* XXX should be tunable */ 354 #endif 355 356 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 357 358 static int 359 filt_nullattach(struct knote *kn) 360 { 361 362 return (ENXIO); 363 }; 364 365 static const struct filterops null_filtops = { 366 .f_isfd = 0, 367 .f_attach = filt_nullattach, 368 .f_copy = knote_triv_copy, 369 }; 370 371 /* XXX - make SYSINIT to add these, and move into respective modules. */ 372 extern const struct filterops sig_filtops; 373 extern const struct filterops fs_filtops; 374 375 /* 376 * Table for all system-defined filters. 377 */ 378 static struct mtx filterops_lock; 379 MTX_SYSINIT(kqueue_filterops, &filterops_lock, "protect sysfilt_ops", MTX_DEF); 380 static struct { 381 const struct filterops *for_fop; 382 int for_nolock; 383 int for_refcnt; 384 } sysfilt_ops[EVFILT_SYSCOUNT] = { 385 [~EVFILT_READ] = { &file_filtops, 1 }, 386 [~EVFILT_WRITE] = { &file_filtops, 1 }, 387 [~EVFILT_AIO] = { &null_filtops }, 388 [~EVFILT_VNODE] = { &file_filtops, 1 }, 389 [~EVFILT_PROC] = { &proc_filtops, 1 }, 390 [~EVFILT_SIGNAL] = { &sig_filtops, 1 }, 391 [~EVFILT_TIMER] = { &timer_filtops, 1 }, 392 [~EVFILT_PROCDESC] = { &file_filtops, 1 }, 393 [~EVFILT_FS] = { &fs_filtops, 1 }, 394 [~EVFILT_LIO] = { &null_filtops }, 395 [~EVFILT_USER] = { &user_filtops, 1 }, 396 [~EVFILT_SENDFILE] = { &null_filtops }, 397 [~EVFILT_EMPTY] = { &file_filtops, 1 }, 398 [~EVFILT_JAIL] = { &jail_filtops, 1 }, 399 [~EVFILT_JAILDESC] = { &file_filtops, 1 }, 400 }; 401 402 /* 403 * Simple redirection for all cdevsw style objects to call their fo_kqfilter 404 * method. 405 */ 406 static int 407 filt_fileattach(struct knote *kn) 408 { 409 410 return (fo_kqfilter(kn->kn_fp, kn)); 411 } 412 413 /*ARGSUSED*/ 414 static int 415 kqueue_kqfilter(struct file *fp, struct knote *kn) 416 { 417 struct kqueue *kq = kn->kn_fp->f_data; 418 419 if (kn->kn_filter != EVFILT_READ) 420 return (EINVAL); 421 422 kn->kn_status |= KN_KQUEUE; 423 kn->kn_fop = &kqread_filtops; 424 knlist_add(&kq->kq_sel.si_note, kn, 0); 425 426 return (0); 427 } 428 429 static void 430 filt_kqdetach(struct knote *kn) 431 { 432 struct kqueue *kq = kn->kn_fp->f_data; 433 434 knlist_remove(&kq->kq_sel.si_note, kn, 0); 435 } 436 437 /*ARGSUSED*/ 438 static int 439 filt_kqueue(struct knote *kn, long hint) 440 { 441 struct kqueue *kq = kn->kn_fp->f_data; 442 443 kn->kn_data = kq->kq_count; 444 return (kn->kn_data > 0); 445 } 446 447 /* XXX - move to kern_proc.c? */ 448 static int 449 filt_procattach(struct knote *kn) 450 { 451 struct proc *p; 452 int error; 453 bool exiting, immediate; 454 455 exiting = immediate = false; 456 if (kn->kn_sfflags & (NOTE_EXIT | NOTE_REAP)) 457 p = pfind_any(kn->kn_id); 458 else 459 p = pfind(kn->kn_id); 460 if (p == NULL) 461 return (ESRCH); 462 if (p->p_flag & P_WEXIT) 463 exiting = true; 464 465 if ((error = p_cansee(curthread, p))) { 466 PROC_UNLOCK(p); 467 return (error); 468 } 469 470 kn->kn_ptr.p_proc = p; 471 kn->kn_flags |= EV_CLEAR; /* automatically set */ 472 473 /* 474 * Internal flag indicating registration done by kernel for the 475 * purposes of getting a NOTE_CHILD notification. 476 */ 477 if (kn->kn_flags & EV_FLAG2) { 478 kn->kn_flags &= ~EV_FLAG2; 479 kn->kn_data = kn->kn_sdata; /* ppid */ 480 kn->kn_fflags = NOTE_CHILD; 481 kn->kn_sfflags &= ~NOTE_PCTRLMASK; 482 immediate = true; /* Force immediate activation of child note. */ 483 } 484 /* 485 * Internal flag indicating registration done by kernel (for other than 486 * NOTE_CHILD). 487 */ 488 if (kn->kn_flags & EV_FLAG1) { 489 kn->kn_flags &= ~EV_FLAG1; 490 } 491 492 knlist_add(p->p_klist, kn, 1); 493 494 /* 495 * Immediately activate any child notes or, in the case of a zombie 496 * target process, exit notes. The latter is necessary to handle the 497 * case where the target process, e.g. a child, dies before the kevent 498 * is registered. 499 */ 500 if (immediate || (exiting && filt_proc(kn, NOTE_EXIT))) 501 KNOTE_ACTIVATE(kn, 0); 502 503 PROC_UNLOCK(p); 504 505 return (0); 506 } 507 508 /* 509 * The knote may be attached to a different process, which may exit, 510 * leaving nothing for the knote to be attached to. So when the process 511 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 512 * it will be deleted when read out. However, as part of the knote deletion, 513 * this routine is called, so a check is needed to avoid actually performing 514 * a detach, because the original process does not exist any more. 515 */ 516 /* XXX - move to kern_proc.c? */ 517 static void 518 filt_procdetach(struct knote *kn) 519 { 520 521 knlist_remove(kn->kn_knlist, kn, 0); 522 kn->kn_ptr.p_proc = NULL; 523 } 524 525 /* XXX - move to kern_proc.c? */ 526 static int 527 filt_proc(struct knote *kn, long hint) 528 { 529 struct proc *p; 530 u_int event; 531 532 p = kn->kn_ptr.p_proc; 533 if (p == NULL) /* already activated, from attach filter */ 534 return (0); 535 536 /* Mask off extra data. */ 537 event = (u_int)hint & NOTE_PCTRLMASK; 538 539 /* If the user is interested in this event, record it. */ 540 if ((kn->kn_sfflags & event) != 0) 541 kn->kn_fflags |= kn->kn_sfflags & event; 542 543 /* Report exit status */ 544 if ((kn->kn_fflags & NOTE_EXIT) != 0) 545 kn->kn_data = KW_EXITCODE(p->p_xexit, p->p_xsig); 546 547 /* Process is gone, so flag the event as finished. */ 548 if ((event & NOTE_REAP) != 0 || 549 ((event & NOTE_EXIT) != 0 && (kn->kn_sfflags & NOTE_REAP) == 0)) { 550 kn->kn_flags |= EV_EOF | EV_ONESHOT; 551 kn->kn_ptr.p_proc = NULL; 552 if (kn->kn_fflags == 0) 553 kn->kn_flags |= EV_DROP; 554 return (1); 555 } 556 557 return (kn->kn_fflags != 0); 558 } 559 560 /* 561 * Called when the process forked. It mostly does the same as the 562 * knote(), activating all knotes registered to be activated when the 563 * process forked. Additionally, for each knote attached to the 564 * parent, check whether user wants to track the new process. If so 565 * attach a new knote to it, and immediately report an event with the 566 * child's pid. 567 */ 568 void 569 knote_fork(struct knlist *list, int pid) 570 { 571 struct kqueue *kq; 572 struct knote *kn; 573 struct kevent kev; 574 int error; 575 576 MPASS(list != NULL); 577 KNL_ASSERT_LOCKED(list); 578 if (SLIST_EMPTY(&list->kl_list)) 579 return; 580 581 memset(&kev, 0, sizeof(kev)); 582 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { 583 kq = kn->kn_kq; 584 KQ_LOCK(kq); 585 if (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0) { 586 KQ_UNLOCK(kq); 587 continue; 588 } 589 590 /* 591 * The same as knote(), activate the event. 592 */ 593 if ((kn->kn_sfflags & NOTE_TRACK) == 0) { 594 if (kn->kn_fop->f_event(kn, NOTE_FORK)) 595 KNOTE_ACTIVATE(kn, 1); 596 KQ_UNLOCK(kq); 597 continue; 598 } 599 600 /* 601 * The NOTE_TRACK case. In addition to the activation 602 * of the event, we need to register new events to 603 * track the child. Drop the locks in preparation for 604 * the call to kqueue_register(). 605 */ 606 kn_enter_flux(kn); 607 KQ_UNLOCK(kq); 608 list->kl_unlock(list->kl_lockarg); 609 610 /* 611 * Activate existing knote and register tracking knotes with 612 * new process. 613 * 614 * First register a knote to get just the child notice. This 615 * must be a separate note from a potential NOTE_EXIT 616 * notification since both NOTE_CHILD and NOTE_EXIT are defined 617 * to use the data field (in conflicting ways). 618 */ 619 kev.ident = pid; 620 kev.filter = kn->kn_filter; 621 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_ONESHOT | 622 EV_FLAG2; 623 kev.fflags = kn->kn_sfflags; 624 kev.data = kn->kn_id; /* parent */ 625 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 626 error = kqueue_register(kq, &kev, NULL, M_NOWAIT); 627 if (error) 628 kn->kn_fflags |= NOTE_TRACKERR; 629 630 /* 631 * Then register another knote to track other potential events 632 * from the new process. 633 */ 634 kev.ident = pid; 635 kev.filter = kn->kn_filter; 636 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 637 kev.fflags = kn->kn_sfflags; 638 kev.data = kn->kn_id; /* parent */ 639 kev.udata = kn->kn_kevent.udata;/* preserve udata */ 640 error = kqueue_register(kq, &kev, NULL, M_NOWAIT); 641 642 /* 643 * Serialize updates to the kn_kevent fields with threads 644 * scanning the queue. 645 */ 646 list->kl_lock(list->kl_lockarg); 647 if (error) 648 kn->kn_fflags |= NOTE_TRACKERR; 649 if (kn->kn_fop->f_event(kn, NOTE_FORK)) { 650 KQ_LOCK(kq); 651 KNOTE_ACTIVATE(kn, 1); 652 } else { 653 KQ_LOCK(kq); 654 } 655 kn_leave_flux(kn); 656 KQ_UNLOCK_FLUX(kq); 657 } 658 } 659 660 int 661 filt_jailattach(struct knote *kn) 662 { 663 struct prison *pr; 664 665 if (kn->kn_id == 0) { 666 /* Let jid=0 watch the current prison (including prison0). */ 667 pr = curthread->td_ucred->cr_prison; 668 mtx_lock(&pr->pr_mtx); 669 } else { 670 sx_slock(&allprison_lock); 671 pr = prison_find_child(curthread->td_ucred->cr_prison, 672 kn->kn_id); 673 sx_sunlock(&allprison_lock); 674 if (pr == NULL) 675 return (ENOENT); 676 if (!prison_isalive(pr)) { 677 mtx_unlock(&pr->pr_mtx); 678 return (ENOENT); 679 } 680 } 681 kn->kn_ptr.p_prison = pr; 682 kn->kn_flags |= EV_CLEAR; 683 knlist_add(pr->pr_klist, kn, 1); 684 mtx_unlock(&pr->pr_mtx); 685 return (0); 686 } 687 688 void 689 filt_jaildetach(struct knote *kn) 690 { 691 if (kn->kn_ptr.p_prison != NULL) { 692 knlist_remove(kn->kn_knlist, kn, 0); 693 kn->kn_ptr.p_prison = NULL; 694 } else 695 kn->kn_status |= KN_DETACHED; 696 } 697 698 int 699 filt_jail(struct knote *kn, long hint) 700 { 701 struct prison *pr; 702 u_int event; 703 704 pr = kn->kn_ptr.p_prison; 705 if (pr == NULL) /* already activated, from attach filter */ 706 return (0); 707 708 /* 709 * Mask off extra data. In the NOTE_JAIL_CHILD case, that's 710 * everything except the NOTE_JAIL_CHILD bit itself, since a 711 * JID is any positive integer. 712 */ 713 event = ((u_int)hint & NOTE_JAIL_CHILD) ? NOTE_JAIL_CHILD : 714 (u_int)hint & NOTE_JAIL_CTRLMASK; 715 716 /* If the user is interested in this event, record it. */ 717 if (kn->kn_sfflags & event) { 718 kn->kn_fflags |= event; 719 /* Report the created jail id or attached process id. */ 720 if (event == NOTE_JAIL_CHILD || event == NOTE_JAIL_ATTACH) { 721 if (kn->kn_data != 0) 722 kn->kn_fflags |= NOTE_JAIL_MULTI; 723 kn->kn_data = (kn->kn_fflags & NOTE_JAIL_MULTI) ? 0U : 724 (u_int)hint & ~event; 725 } 726 } 727 728 /* Prison is gone, so flag the event as finished. */ 729 if (event == NOTE_JAIL_REMOVE) { 730 kn->kn_flags |= EV_EOF | EV_ONESHOT; 731 kn->kn_ptr.p_prison = NULL; 732 if (kn->kn_fflags == 0) 733 kn->kn_flags |= EV_DROP; 734 return (1); 735 } 736 737 return (kn->kn_fflags != 0); 738 } 739 740 /* 741 * XXX: EVFILT_TIMER should perhaps live in kern_time.c beside the 742 * interval timer support code. 743 */ 744 745 #define NOTE_TIMER_PRECMASK \ 746 (NOTE_SECONDS | NOTE_MSECONDS | NOTE_USECONDS | NOTE_NSECONDS) 747 748 static sbintime_t 749 timer2sbintime(int64_t data, unsigned int flags) 750 { 751 int64_t secs; 752 753 /* 754 * Macros for converting to the fractional second portion of an 755 * sbintime_t using 64bit multiplication to improve precision. 756 */ 757 #define NS_TO_SBT(ns) (((ns) * (((uint64_t)1 << 63) / 500000000)) >> 32) 758 #define US_TO_SBT(us) (((us) * (((uint64_t)1 << 63) / 500000)) >> 32) 759 #define MS_TO_SBT(ms) (((ms) * (((uint64_t)1 << 63) / 500)) >> 32) 760 switch (flags & NOTE_TIMER_PRECMASK) { 761 case NOTE_SECONDS: 762 #ifdef __LP64__ 763 if (data > (SBT_MAX / SBT_1S)) 764 return (SBT_MAX); 765 #endif 766 return ((sbintime_t)data << 32); 767 case NOTE_MSECONDS: /* FALLTHROUGH */ 768 case 0: 769 if (data >= 1000) { 770 secs = data / 1000; 771 #ifdef __LP64__ 772 if (secs > (SBT_MAX / SBT_1S)) 773 return (SBT_MAX); 774 #endif 775 return (secs << 32 | MS_TO_SBT(data % 1000)); 776 } 777 return (MS_TO_SBT(data)); 778 case NOTE_USECONDS: 779 if (data >= 1000000) { 780 secs = data / 1000000; 781 #ifdef __LP64__ 782 if (secs > (SBT_MAX / SBT_1S)) 783 return (SBT_MAX); 784 #endif 785 return (secs << 32 | US_TO_SBT(data % 1000000)); 786 } 787 return (US_TO_SBT(data)); 788 case NOTE_NSECONDS: 789 if (data >= 1000000000) { 790 secs = data / 1000000000; 791 #ifdef __LP64__ 792 if (secs > (SBT_MAX / SBT_1S)) 793 return (SBT_MAX); 794 #endif 795 return (secs << 32 | NS_TO_SBT(data % 1000000000)); 796 } 797 return (NS_TO_SBT(data)); 798 default: 799 break; 800 } 801 return (-1); 802 } 803 804 struct kq_timer_cb_data { 805 struct callout c; 806 struct proc *p; 807 struct knote *kn; 808 int cpuid; 809 int flags; 810 TAILQ_ENTRY(kq_timer_cb_data) link; 811 sbintime_t next; /* next timer event fires at */ 812 sbintime_t to; /* precalculated timer period, 0 for abs */ 813 }; 814 815 #define KQ_TIMER_CB_ENQUEUED 0x01 816 817 static void 818 kqtimer_sched_callout(struct kq_timer_cb_data *kc) 819 { 820 callout_reset_sbt_on(&kc->c, kc->next, 0, filt_timerexpire, kc->kn, 821 kc->cpuid, C_ABSOLUTE); 822 } 823 824 void 825 kqtimer_proc_continue(struct proc *p) 826 { 827 struct kq_timer_cb_data *kc, *kc1; 828 sbintime_t now; 829 830 PROC_LOCK_ASSERT(p, MA_OWNED); 831 832 now = sbinuptime(); 833 TAILQ_FOREACH_SAFE(kc, &p->p_kqtim_stop, link, kc1) { 834 TAILQ_REMOVE(&p->p_kqtim_stop, kc, link); 835 kc->flags &= ~KQ_TIMER_CB_ENQUEUED; 836 if (kc->next <= now) 837 filt_timerexpire_l(kc->kn, true); 838 else 839 kqtimer_sched_callout(kc); 840 } 841 } 842 843 static void 844 filt_timerexpire_l(struct knote *kn, bool proc_locked) 845 { 846 struct kq_timer_cb_data *kc; 847 struct proc *p; 848 uint64_t delta; 849 sbintime_t now; 850 851 kc = kn->kn_ptr.p_v; 852 853 if ((kn->kn_flags & EV_ONESHOT) != 0 || kc->to == 0) { 854 kn->kn_data++; 855 KNOTE_ACTIVATE(kn, 0); 856 return; 857 } 858 859 now = sbinuptime(); 860 if (now >= kc->next) { 861 delta = (now - kc->next) / kc->to; 862 if (delta == 0) 863 delta = 1; 864 kn->kn_data += delta; 865 kc->next += delta * kc->to; 866 if (now >= kc->next) /* overflow */ 867 kc->next = now + kc->to; 868 KNOTE_ACTIVATE(kn, 0); /* XXX - handle locking */ 869 } 870 871 /* 872 * Initial check for stopped kc->p is racy. It is fine to 873 * miss the set of the stop flags, at worst we would schedule 874 * one more callout. On the other hand, it is not fine to not 875 * schedule when we we missed clearing of the flags, we 876 * recheck them under the lock and observe consistent state. 877 */ 878 p = kc->p; 879 if (P_SHOULDSTOP(p) || P_KILLED(p)) { 880 if (!proc_locked) 881 PROC_LOCK(p); 882 if (P_SHOULDSTOP(p) || P_KILLED(p)) { 883 if ((kc->flags & KQ_TIMER_CB_ENQUEUED) == 0) { 884 /* 885 * Insert into head so that 886 * kqtimer_proc_continue() does not 887 * iterate into us again. 888 */ 889 kc->flags |= KQ_TIMER_CB_ENQUEUED; 890 TAILQ_INSERT_HEAD(&p->p_kqtim_stop, kc, link); 891 } 892 if (!proc_locked) 893 PROC_UNLOCK(p); 894 return; 895 } 896 if (!proc_locked) 897 PROC_UNLOCK(p); 898 } 899 kqtimer_sched_callout(kc); 900 } 901 902 static void 903 filt_timerexpire(void *knx) 904 { 905 filt_timerexpire_l(knx, false); 906 } 907 908 /* 909 * data contains amount of time to sleep 910 */ 911 static int 912 filt_timervalidate(struct knote *kn, sbintime_t *to) 913 { 914 struct bintime bt; 915 sbintime_t sbt; 916 917 if (kn->kn_sdata < 0) 918 return (EINVAL); 919 if (kn->kn_sdata == 0 && (kn->kn_flags & EV_ONESHOT) == 0) 920 kn->kn_sdata = 1; 921 /* 922 * The only fflags values supported are the timer unit 923 * (precision) and the absolute time indicator. 924 */ 925 if ((kn->kn_sfflags & ~(NOTE_TIMER_PRECMASK | NOTE_ABSTIME)) != 0) 926 return (EINVAL); 927 928 *to = timer2sbintime(kn->kn_sdata, kn->kn_sfflags); 929 if (*to < 0) 930 return (EINVAL); 931 if ((kn->kn_sfflags & NOTE_ABSTIME) != 0) { 932 getboottimebin(&bt); 933 sbt = bttosbt(bt); 934 *to = MAX(0, *to - sbt); 935 } 936 return (0); 937 } 938 939 static int 940 filt_timerattach(struct knote *kn) 941 { 942 struct kq_timer_cb_data *kc; 943 sbintime_t to; 944 int error; 945 946 to = -1; 947 error = filt_timervalidate(kn, &to); 948 if (error != 0) 949 return (error); 950 KASSERT(to > 0 || (kn->kn_flags & EV_ONESHOT) != 0 || 951 (kn->kn_sfflags & NOTE_ABSTIME) != 0, 952 ("%s: periodic timer has a calculated zero timeout", __func__)); 953 KASSERT(to >= 0, 954 ("%s: timer has a calculated negative timeout", __func__)); 955 956 if (atomic_fetchadd_int(&kq_ncallouts, 1) + 1 > kq_calloutmax) { 957 atomic_subtract_int(&kq_ncallouts, 1); 958 return (ENOMEM); 959 } 960 961 if ((kn->kn_sfflags & NOTE_ABSTIME) == 0) 962 kn->kn_flags |= EV_CLEAR; /* automatically set */ 963 kn->kn_status &= ~KN_DETACHED; /* knlist_add clears it */ 964 kn->kn_ptr.p_v = kc = malloc(sizeof(*kc), M_KQUEUE, M_WAITOK); 965 kc->kn = kn; 966 kc->p = curproc; 967 kc->cpuid = PCPU_GET(cpuid); 968 kc->flags = 0; 969 callout_init(&kc->c, 1); 970 filt_timerstart(kn, to); 971 972 return (0); 973 } 974 975 static int 976 filt_timercopy(struct knote *kn, struct proc *p) 977 { 978 struct kq_timer_cb_data *kc_src, *kc; 979 980 if (atomic_fetchadd_int(&kq_ncallouts, 1) + 1 > kq_calloutmax) { 981 atomic_subtract_int(&kq_ncallouts, 1); 982 return (ENOMEM); 983 } 984 985 kn->kn_status &= ~KN_DETACHED; 986 kc_src = kn->kn_ptr.p_v; 987 kn->kn_ptr.p_v = kc = malloc(sizeof(*kc), M_KQUEUE, M_WAITOK); 988 kc->kn = kn; 989 kc->p = p; 990 kc->flags = kc_src->flags & ~KQ_TIMER_CB_ENQUEUED; 991 kc->next = kc_src->next; 992 kc->to = kc_src->to; 993 kc->cpuid = PCPU_GET(cpuid); 994 callout_init(&kc->c, 1); 995 kqtimer_sched_callout(kc); 996 return (0); 997 } 998 999 static void 1000 filt_timerstart(struct knote *kn, sbintime_t to) 1001 { 1002 struct kq_timer_cb_data *kc; 1003 1004 kc = kn->kn_ptr.p_v; 1005 if ((kn->kn_sfflags & NOTE_ABSTIME) != 0) { 1006 kc->next = to; 1007 kc->to = 0; 1008 } else { 1009 kc->next = to + sbinuptime(); 1010 kc->to = to; 1011 } 1012 kqtimer_sched_callout(kc); 1013 } 1014 1015 static void 1016 filt_timerdetach(struct knote *kn) 1017 { 1018 struct kq_timer_cb_data *kc; 1019 unsigned int old __unused; 1020 bool pending; 1021 1022 kc = kn->kn_ptr.p_v; 1023 do { 1024 callout_drain(&kc->c); 1025 1026 /* 1027 * kqtimer_proc_continue() might have rescheduled this callout. 1028 * Double-check, using the process mutex as an interlock. 1029 */ 1030 PROC_LOCK(kc->p); 1031 if ((kc->flags & KQ_TIMER_CB_ENQUEUED) != 0) { 1032 kc->flags &= ~KQ_TIMER_CB_ENQUEUED; 1033 TAILQ_REMOVE(&kc->p->p_kqtim_stop, kc, link); 1034 } 1035 pending = callout_pending(&kc->c); 1036 PROC_UNLOCK(kc->p); 1037 } while (pending); 1038 free(kc, M_KQUEUE); 1039 old = atomic_fetchadd_int(&kq_ncallouts, -1); 1040 KASSERT(old > 0, ("Number of callouts cannot become negative")); 1041 kn->kn_status |= KN_DETACHED; /* knlist_remove sets it */ 1042 } 1043 1044 static void 1045 filt_timertouch(struct knote *kn, struct kevent *kev, u_long type) 1046 { 1047 struct kq_timer_cb_data *kc; 1048 struct kqueue *kq; 1049 sbintime_t to; 1050 int error; 1051 1052 switch (type) { 1053 case EVENT_REGISTER: 1054 /* Handle re-added timers that update data/fflags */ 1055 if (kev->flags & EV_ADD) { 1056 kc = kn->kn_ptr.p_v; 1057 1058 /* Drain any existing callout. */ 1059 callout_drain(&kc->c); 1060 1061 /* Throw away any existing undelivered record 1062 * of the timer expiration. This is done under 1063 * the presumption that if a process is 1064 * re-adding this timer with new parameters, 1065 * it is no longer interested in what may have 1066 * happened under the old parameters. If it is 1067 * interested, it can wait for the expiration, 1068 * delete the old timer definition, and then 1069 * add the new one. 1070 * 1071 * This has to be done while the kq is locked: 1072 * - if enqueued, dequeue 1073 * - make it no longer active 1074 * - clear the count of expiration events 1075 */ 1076 kq = kn->kn_kq; 1077 KQ_LOCK(kq); 1078 if (kn->kn_status & KN_QUEUED) 1079 knote_dequeue(kn); 1080 1081 kn->kn_status &= ~KN_ACTIVE; 1082 kn->kn_data = 0; 1083 KQ_UNLOCK(kq); 1084 1085 /* Reschedule timer based on new data/fflags */ 1086 kn->kn_sfflags = kev->fflags; 1087 kn->kn_sdata = kev->data; 1088 error = filt_timervalidate(kn, &to); 1089 if (error != 0) { 1090 kn->kn_flags |= EV_ERROR; 1091 kn->kn_data = error; 1092 } else 1093 filt_timerstart(kn, to); 1094 } 1095 break; 1096 1097 case EVENT_PROCESS: 1098 *kev = kn->kn_kevent; 1099 if (kn->kn_flags & EV_CLEAR) { 1100 kn->kn_data = 0; 1101 kn->kn_fflags = 0; 1102 } 1103 break; 1104 1105 default: 1106 panic("filt_timertouch() - invalid type (%ld)", type); 1107 break; 1108 } 1109 } 1110 1111 static int 1112 filt_timer(struct knote *kn, long hint) 1113 { 1114 1115 return (kn->kn_data != 0); 1116 } 1117 1118 static int 1119 filt_userattach(struct knote *kn) 1120 { 1121 1122 /* 1123 * EVFILT_USER knotes are not attached to anything in the kernel. 1124 */ 1125 kn->kn_hook = NULL; 1126 if (kn->kn_fflags & NOTE_TRIGGER) 1127 kn->kn_hookid = 1; 1128 else 1129 kn->kn_hookid = 0; 1130 return (0); 1131 } 1132 1133 static void 1134 filt_userdetach(__unused struct knote *kn) 1135 { 1136 1137 /* 1138 * EVFILT_USER knotes are not attached to anything in the kernel. 1139 */ 1140 } 1141 1142 static int 1143 filt_user(struct knote *kn, __unused long hint) 1144 { 1145 1146 return (kn->kn_hookid); 1147 } 1148 1149 static void 1150 filt_usertouch(struct knote *kn, struct kevent *kev, u_long type) 1151 { 1152 u_int ffctrl; 1153 1154 switch (type) { 1155 case EVENT_REGISTER: 1156 if (kev->fflags & NOTE_TRIGGER) 1157 kn->kn_hookid = 1; 1158 1159 ffctrl = kev->fflags & NOTE_FFCTRLMASK; 1160 kev->fflags &= NOTE_FFLAGSMASK; 1161 switch (ffctrl) { 1162 case NOTE_FFNOP: 1163 break; 1164 1165 case NOTE_FFAND: 1166 kn->kn_sfflags &= kev->fflags; 1167 break; 1168 1169 case NOTE_FFOR: 1170 kn->kn_sfflags |= kev->fflags; 1171 break; 1172 1173 case NOTE_FFCOPY: 1174 kn->kn_sfflags = kev->fflags; 1175 break; 1176 1177 default: 1178 /* XXX Return error? */ 1179 break; 1180 } 1181 kn->kn_sdata = kev->data; 1182 if (kev->flags & EV_CLEAR) { 1183 kn->kn_hookid = 0; 1184 kn->kn_data = 0; 1185 kn->kn_fflags = 0; 1186 } 1187 break; 1188 1189 case EVENT_PROCESS: 1190 *kev = kn->kn_kevent; 1191 kev->fflags = kn->kn_sfflags; 1192 kev->data = kn->kn_sdata; 1193 if (kn->kn_flags & EV_CLEAR) { 1194 kn->kn_hookid = 0; 1195 kn->kn_data = 0; 1196 kn->kn_fflags = 0; 1197 } 1198 break; 1199 1200 default: 1201 panic("filt_usertouch() - invalid type (%ld)", type); 1202 break; 1203 } 1204 } 1205 1206 int 1207 sys_kqueue(struct thread *td, struct kqueue_args *uap) 1208 { 1209 1210 return (kern_kqueue(td, 0, false, NULL)); 1211 } 1212 1213 int 1214 sys_kqueuex(struct thread *td, struct kqueuex_args *uap) 1215 { 1216 int flags; 1217 1218 if ((uap->flags & ~(KQUEUE_CLOEXEC | KQUEUE_CPONFORK)) != 0) 1219 return (EINVAL); 1220 flags = 0; 1221 if ((uap->flags & KQUEUE_CLOEXEC) != 0) 1222 flags |= O_CLOEXEC; 1223 return (kern_kqueue(td, flags, (uap->flags & KQUEUE_CPONFORK) != 0, 1224 NULL)); 1225 } 1226 1227 static void 1228 kqueue_init(struct kqueue *kq, bool cponfork) 1229 { 1230 1231 mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF | MTX_DUPOK); 1232 TAILQ_INIT(&kq->kq_head); 1233 knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock); 1234 TASK_INIT(&kq->kq_task, 0, kqueue_task, kq); 1235 if (cponfork) 1236 kq->kq_state |= KQ_CPONFORK; 1237 } 1238 1239 static int 1240 kern_kqueue_alloc(struct thread *td, struct filedesc *fdp, int *fdip, 1241 struct file **fpp, int flags, struct filecaps *fcaps, bool cponfork, 1242 struct kqueue **kqp) 1243 { 1244 struct ucred *cred; 1245 struct kqueue *kq; 1246 int error; 1247 1248 cred = td->td_ucred; 1249 if (!chgkqcnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_KQUEUES))) 1250 return (ENOMEM); 1251 1252 error = fdip != NULL ? falloc_caps(td, fpp, fdip, flags, fcaps) : 1253 _falloc_noinstall(td, fpp, 1); 1254 if (error != 0) { 1255 chgkqcnt(cred->cr_ruidinfo, -1, 0); 1256 return (error); 1257 } 1258 1259 /* An extra reference on `fp' has been held for us by falloc(). */ 1260 kq = malloc(sizeof(*kq), M_KQUEUE, M_WAITOK | M_ZERO); 1261 kqueue_init(kq, cponfork); 1262 kq->kq_fdp = fdp; 1263 kq->kq_cred = crhold(cred); 1264 1265 if (fdip != NULL) 1266 FILEDESC_XLOCK(fdp); 1267 TAILQ_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list); 1268 if (fdip != NULL) 1269 FILEDESC_XUNLOCK(fdp); 1270 1271 finit(*fpp, FREAD | FWRITE, DTYPE_KQUEUE, kq, &kqueueops); 1272 *kqp = kq; 1273 return (0); 1274 } 1275 1276 int 1277 kern_kqueue(struct thread *td, int flags, bool cponfork, struct filecaps *fcaps) 1278 { 1279 struct kqueue *kq; 1280 struct file *fp; 1281 int fd, error; 1282 1283 error = kern_kqueue_alloc(td, td->td_proc->p_fd, &fd, &fp, flags, 1284 fcaps, cponfork, &kq); 1285 if (error != 0) 1286 return (error); 1287 1288 fdrop(fp, td); 1289 1290 td->td_retval[0] = fd; 1291 return (0); 1292 } 1293 1294 struct g_kevent_args { 1295 int fd; 1296 const void *changelist; 1297 int nchanges; 1298 void *eventlist; 1299 int nevents; 1300 const struct timespec *timeout; 1301 }; 1302 1303 int 1304 sys_kevent(struct thread *td, struct kevent_args *uap) 1305 { 1306 struct kevent_copyops k_ops = { 1307 .arg = uap, 1308 .k_copyout = kevent_copyout, 1309 .k_copyin = kevent_copyin, 1310 .kevent_size = sizeof(struct kevent), 1311 }; 1312 struct g_kevent_args gk_args = { 1313 .fd = uap->fd, 1314 .changelist = uap->changelist, 1315 .nchanges = uap->nchanges, 1316 .eventlist = uap->eventlist, 1317 .nevents = uap->nevents, 1318 .timeout = uap->timeout, 1319 }; 1320 1321 return (kern_kevent_generic(td, &gk_args, &k_ops, "kevent")); 1322 } 1323 1324 static int 1325 kern_kevent_generic(struct thread *td, struct g_kevent_args *uap, 1326 struct kevent_copyops *k_ops, const char *struct_name) 1327 { 1328 struct timespec ts, *tsp; 1329 #ifdef KTRACE 1330 struct kevent *eventlist = uap->eventlist; 1331 #endif 1332 int error; 1333 1334 if (uap->timeout != NULL) { 1335 error = copyin(uap->timeout, &ts, sizeof(ts)); 1336 if (error) 1337 return (error); 1338 tsp = &ts; 1339 } else 1340 tsp = NULL; 1341 1342 #ifdef KTRACE 1343 if (KTRPOINT(td, KTR_STRUCT_ARRAY)) 1344 ktrstructarray(struct_name, UIO_USERSPACE, uap->changelist, 1345 uap->nchanges, k_ops->kevent_size); 1346 #endif 1347 1348 error = kern_kevent(td, uap->fd, uap->nchanges, uap->nevents, 1349 k_ops, tsp); 1350 1351 #ifdef KTRACE 1352 if (error == 0 && KTRPOINT(td, KTR_STRUCT_ARRAY)) 1353 ktrstructarray(struct_name, UIO_USERSPACE, eventlist, 1354 td->td_retval[0], k_ops->kevent_size); 1355 #endif 1356 1357 return (error); 1358 } 1359 1360 /* 1361 * Copy 'count' items into the destination list pointed to by uap->eventlist. 1362 */ 1363 static int 1364 kevent_copyout(void *arg, struct kevent *kevp, int count) 1365 { 1366 struct kevent_args *uap; 1367 int error; 1368 1369 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1370 uap = (struct kevent_args *)arg; 1371 1372 error = copyout(kevp, uap->eventlist, count * sizeof *kevp); 1373 if (error == 0) 1374 uap->eventlist += count; 1375 return (error); 1376 } 1377 1378 /* 1379 * Copy 'count' items from the list pointed to by uap->changelist. 1380 */ 1381 static int 1382 kevent_copyin(void *arg, struct kevent *kevp, int count) 1383 { 1384 struct kevent_args *uap; 1385 int error; 1386 1387 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1388 uap = (struct kevent_args *)arg; 1389 1390 error = copyin(uap->changelist, kevp, count * sizeof *kevp); 1391 if (error == 0) 1392 uap->changelist += count; 1393 return (error); 1394 } 1395 1396 #ifdef COMPAT_FREEBSD11 1397 static int 1398 kevent11_copyout(void *arg, struct kevent *kevp, int count) 1399 { 1400 struct freebsd11_kevent_args *uap; 1401 struct freebsd11_kevent kev11; 1402 int error, i; 1403 1404 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1405 uap = (struct freebsd11_kevent_args *)arg; 1406 1407 for (i = 0; i < count; i++) { 1408 kev11.ident = kevp->ident; 1409 kev11.filter = kevp->filter; 1410 kev11.flags = kevp->flags; 1411 kev11.fflags = kevp->fflags; 1412 kev11.data = kevp->data; 1413 kev11.udata = kevp->udata; 1414 error = copyout(&kev11, uap->eventlist, sizeof(kev11)); 1415 if (error != 0) 1416 break; 1417 uap->eventlist++; 1418 kevp++; 1419 } 1420 return (error); 1421 } 1422 1423 /* 1424 * Copy 'count' items from the list pointed to by uap->changelist. 1425 */ 1426 static int 1427 kevent11_copyin(void *arg, struct kevent *kevp, int count) 1428 { 1429 struct freebsd11_kevent_args *uap; 1430 struct freebsd11_kevent kev11; 1431 int error, i; 1432 1433 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count)); 1434 uap = (struct freebsd11_kevent_args *)arg; 1435 1436 for (i = 0; i < count; i++) { 1437 error = copyin(uap->changelist, &kev11, sizeof(kev11)); 1438 if (error != 0) 1439 break; 1440 kevp->ident = kev11.ident; 1441 kevp->filter = kev11.filter; 1442 kevp->flags = kev11.flags; 1443 kevp->fflags = kev11.fflags; 1444 kevp->data = (uintptr_t)kev11.data; 1445 kevp->udata = kev11.udata; 1446 bzero(&kevp->ext, sizeof(kevp->ext)); 1447 uap->changelist++; 1448 kevp++; 1449 } 1450 return (error); 1451 } 1452 1453 int 1454 freebsd11_kevent(struct thread *td, struct freebsd11_kevent_args *uap) 1455 { 1456 struct kevent_copyops k_ops = { 1457 .arg = uap, 1458 .k_copyout = kevent11_copyout, 1459 .k_copyin = kevent11_copyin, 1460 .kevent_size = sizeof(struct freebsd11_kevent), 1461 }; 1462 struct g_kevent_args gk_args = { 1463 .fd = uap->fd, 1464 .changelist = uap->changelist, 1465 .nchanges = uap->nchanges, 1466 .eventlist = uap->eventlist, 1467 .nevents = uap->nevents, 1468 .timeout = uap->timeout, 1469 }; 1470 1471 return (kern_kevent_generic(td, &gk_args, &k_ops, "freebsd11_kevent")); 1472 } 1473 #endif 1474 1475 int 1476 kern_kevent(struct thread *td, int fd, int nchanges, int nevents, 1477 struct kevent_copyops *k_ops, const struct timespec *timeout) 1478 { 1479 cap_rights_t rights; 1480 struct file *fp; 1481 int error; 1482 1483 cap_rights_init_zero(&rights); 1484 if (nchanges > 0) 1485 cap_rights_set_one(&rights, CAP_KQUEUE_CHANGE); 1486 if (nevents > 0) 1487 cap_rights_set_one(&rights, CAP_KQUEUE_EVENT); 1488 error = fget(td, fd, &rights, &fp); 1489 if (error != 0) 1490 return (error); 1491 1492 error = kern_kevent_fp(td, fp, nchanges, nevents, k_ops, timeout); 1493 fdrop(fp, td); 1494 1495 return (error); 1496 } 1497 1498 static int 1499 kqueue_kevent(struct kqueue *kq, struct thread *td, int nchanges, int nevents, 1500 struct kevent_copyops *k_ops, const struct timespec *timeout) 1501 { 1502 struct kevent keva[KQ_NEVENTS]; 1503 struct kevent *kevp, *changes; 1504 int i, n, nerrors, error; 1505 1506 if (nchanges < 0) 1507 return (EINVAL); 1508 1509 nerrors = 0; 1510 while (nchanges > 0) { 1511 n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges; 1512 error = k_ops->k_copyin(k_ops->arg, keva, n); 1513 if (error) 1514 return (error); 1515 changes = keva; 1516 for (i = 0; i < n; i++) { 1517 kevp = &changes[i]; 1518 if (!kevp->filter) 1519 continue; 1520 kevp->flags &= ~EV_SYSFLAGS; 1521 error = kqueue_register(kq, kevp, td, M_WAITOK); 1522 if (error || (kevp->flags & EV_RECEIPT)) { 1523 if (nevents == 0) 1524 return (error); 1525 kevp->flags = EV_ERROR; 1526 kevp->data = error; 1527 (void)k_ops->k_copyout(k_ops->arg, kevp, 1); 1528 nevents--; 1529 nerrors++; 1530 } 1531 } 1532 nchanges -= n; 1533 } 1534 if (nerrors) { 1535 td->td_retval[0] = nerrors; 1536 return (0); 1537 } 1538 1539 return (kqueue_scan(kq, nevents, k_ops, timeout, keva, td)); 1540 } 1541 1542 int 1543 kern_kevent_fp(struct thread *td, struct file *fp, int nchanges, int nevents, 1544 struct kevent_copyops *k_ops, const struct timespec *timeout) 1545 { 1546 struct kqueue *kq; 1547 int error; 1548 1549 error = kqueue_acquire(fp, &kq); 1550 if (error != 0) 1551 return (error); 1552 error = kqueue_kevent(kq, td, nchanges, nevents, k_ops, timeout); 1553 kqueue_release(kq, 0); 1554 return (error); 1555 } 1556 1557 /* 1558 * Performs a kevent() call on a temporarily created kqueue. This can be 1559 * used to perform one-shot polling, similar to poll() and select(). 1560 */ 1561 int 1562 kern_kevent_anonymous(struct thread *td, int nevents, 1563 struct kevent_copyops *k_ops) 1564 { 1565 struct kqueue kq = {}; 1566 int error; 1567 1568 kqueue_init(&kq, false); 1569 kq.kq_refcnt = 1; 1570 error = kqueue_kevent(&kq, td, nevents, nevents, k_ops, NULL); 1571 kqueue_drain(&kq, td); 1572 kqueue_destroy(&kq); 1573 return (error); 1574 } 1575 1576 int 1577 kqueue_add_filteropts(int filt, const struct filterops *filtops) 1578 { 1579 int error; 1580 1581 error = 0; 1582 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) { 1583 printf( 1584 "trying to add a filterop that is out of range: %d is beyond %d\n", 1585 ~filt, EVFILT_SYSCOUNT); 1586 return EINVAL; 1587 } 1588 mtx_lock(&filterops_lock); 1589 if (sysfilt_ops[~filt].for_fop != &null_filtops && 1590 sysfilt_ops[~filt].for_fop != NULL) 1591 error = EEXIST; 1592 else { 1593 sysfilt_ops[~filt].for_fop = filtops; 1594 sysfilt_ops[~filt].for_refcnt = 0; 1595 } 1596 mtx_unlock(&filterops_lock); 1597 1598 return (error); 1599 } 1600 1601 int 1602 kqueue_del_filteropts(int filt) 1603 { 1604 int error; 1605 1606 error = 0; 1607 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1608 return EINVAL; 1609 1610 mtx_lock(&filterops_lock); 1611 if (sysfilt_ops[~filt].for_fop == &null_filtops || 1612 sysfilt_ops[~filt].for_fop == NULL) 1613 error = EINVAL; 1614 else if (sysfilt_ops[~filt].for_refcnt != 0) 1615 error = EBUSY; 1616 else { 1617 sysfilt_ops[~filt].for_fop = &null_filtops; 1618 sysfilt_ops[~filt].for_refcnt = 0; 1619 } 1620 mtx_unlock(&filterops_lock); 1621 1622 return error; 1623 } 1624 1625 static const struct filterops * 1626 kqueue_fo_find(int filt) 1627 { 1628 1629 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1630 return NULL; 1631 1632 if (sysfilt_ops[~filt].for_nolock) 1633 return sysfilt_ops[~filt].for_fop; 1634 1635 mtx_lock(&filterops_lock); 1636 sysfilt_ops[~filt].for_refcnt++; 1637 if (sysfilt_ops[~filt].for_fop == NULL) 1638 sysfilt_ops[~filt].for_fop = &null_filtops; 1639 mtx_unlock(&filterops_lock); 1640 1641 return sysfilt_ops[~filt].for_fop; 1642 } 1643 1644 static void 1645 kqueue_fo_release(int filt) 1646 { 1647 1648 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) 1649 return; 1650 1651 if (sysfilt_ops[~filt].for_nolock) 1652 return; 1653 1654 mtx_lock(&filterops_lock); 1655 KASSERT(sysfilt_ops[~filt].for_refcnt > 0, 1656 ("filter object %d refcount not valid on release", filt)); 1657 sysfilt_ops[~filt].for_refcnt--; 1658 mtx_unlock(&filterops_lock); 1659 } 1660 1661 /* 1662 * A ref to kq (obtained via kqueue_acquire) must be held. 1663 */ 1664 static int 1665 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, 1666 int mflag) 1667 { 1668 const struct filterops *fops; 1669 struct file *fp; 1670 struct knote *kn, *tkn; 1671 struct knlist *knl; 1672 int error, filt, event; 1673 int haskqglobal, filedesc_unlock; 1674 1675 if ((kev->flags & (EV_ENABLE | EV_DISABLE)) == (EV_ENABLE | EV_DISABLE)) 1676 return (EINVAL); 1677 1678 fp = NULL; 1679 kn = NULL; 1680 knl = NULL; 1681 error = 0; 1682 haskqglobal = 0; 1683 filedesc_unlock = 0; 1684 1685 filt = kev->filter; 1686 fops = kqueue_fo_find(filt); 1687 if (fops == NULL) 1688 return EINVAL; 1689 1690 if (kev->flags & EV_ADD) { 1691 /* Reject an invalid flag pair early */ 1692 if (kev->flags & EV_KEEPUDATA) { 1693 tkn = NULL; 1694 error = EINVAL; 1695 goto done; 1696 } 1697 1698 /* 1699 * Prevent waiting with locks. Non-sleepable 1700 * allocation failures are handled in the loop, only 1701 * if the spare knote appears to be actually required. 1702 */ 1703 tkn = knote_alloc(mflag); 1704 } else { 1705 tkn = NULL; 1706 } 1707 1708 findkn: 1709 if (fops->f_isfd) { 1710 KASSERT(td != NULL, ("td is NULL")); 1711 if (kev->ident > INT_MAX) 1712 error = EBADF; 1713 else 1714 error = fget(td, kev->ident, &cap_event_rights, &fp); 1715 if (error) 1716 goto done; 1717 1718 if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops, 1719 kev->ident, M_NOWAIT) != 0) { 1720 /* try again */ 1721 fdrop(fp, td); 1722 fp = NULL; 1723 error = kqueue_expand(kq, fops, kev->ident, mflag); 1724 if (error) 1725 goto done; 1726 goto findkn; 1727 } 1728 1729 if (fp->f_type == DTYPE_KQUEUE) { 1730 /* 1731 * If we add some intelligence about what we are doing, 1732 * we should be able to support events on ourselves. 1733 * We need to know when we are doing this to prevent 1734 * getting both the knlist lock and the kq lock since 1735 * they are the same thing. 1736 */ 1737 if (fp->f_data == kq) { 1738 error = EINVAL; 1739 goto done; 1740 } 1741 1742 /* 1743 * Pre-lock the filedesc before the global 1744 * lock mutex, see the comment in 1745 * kqueue_close(). 1746 */ 1747 FILEDESC_XLOCK(td->td_proc->p_fd); 1748 filedesc_unlock = 1; 1749 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 1750 } 1751 1752 KQ_LOCK(kq); 1753 if (kev->ident < kq->kq_knlistsize) { 1754 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link) { 1755 MPASS(kn->kn_kq == kq); 1756 if (kev->filter == kn->kn_filter) 1757 break; 1758 } 1759 } 1760 } else { 1761 if ((kev->flags & EV_ADD) == EV_ADD) { 1762 error = kqueue_expand(kq, fops, kev->ident, mflag); 1763 if (error != 0) 1764 goto done; 1765 } 1766 1767 KQ_LOCK(kq); 1768 1769 /* 1770 * If possible, find an existing knote to use for this kevent. 1771 */ 1772 if (kev->filter == EVFILT_PROC && 1773 (kev->flags & (EV_FLAG1 | EV_FLAG2)) != 0) { 1774 /* This is an internal creation of a process tracking 1775 * note. Don't attempt to coalesce this with an 1776 * existing note. 1777 */ 1778 ; 1779 } else if (kq->kq_knhashmask != 0) { 1780 struct klist *list; 1781 1782 list = &kq->kq_knhash[ 1783 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)]; 1784 SLIST_FOREACH(kn, list, kn_link) { 1785 MPASS(kn->kn_kq == kq); 1786 if (kev->ident == kn->kn_id && 1787 kev->filter == kn->kn_filter) 1788 break; 1789 } 1790 } 1791 } 1792 1793 /* knote is in the process of changing, wait for it to stabilize. */ 1794 if (kn != NULL && kn_in_flux(kn)) { 1795 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1796 if (filedesc_unlock) { 1797 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1798 filedesc_unlock = 0; 1799 } 1800 KQ_FLUX_SLEEP(kq, kn, PDROP); 1801 if (fp != NULL) { 1802 fdrop(fp, td); 1803 fp = NULL; 1804 } 1805 goto findkn; 1806 } 1807 1808 /* 1809 * kn now contains the matching knote, or NULL if no match 1810 */ 1811 if (kn == NULL) { 1812 if (kev->flags & EV_ADD) { 1813 kn = tkn; 1814 tkn = NULL; 1815 if (kn == NULL) { 1816 KQ_UNLOCK(kq); 1817 error = ENOMEM; 1818 goto done; 1819 } 1820 1821 /* 1822 * Now that the kqueue is locked, make sure the fd 1823 * didn't change out from under us. 1824 */ 1825 if (fops->f_isfd && 1826 fget_noref_unlocked(td->td_proc->p_fd, 1827 kev->ident) != fp) { 1828 KQ_UNLOCK(kq); 1829 tkn = kn; 1830 error = EBADF; 1831 goto done; 1832 } 1833 kn->kn_fp = fp; 1834 kn->kn_kq = kq; 1835 kn->kn_fop = fops; 1836 1837 kn->kn_sfflags = kev->fflags; 1838 kn->kn_sdata = kev->data; 1839 kev->fflags = 0; 1840 kev->data = 0; 1841 kn->kn_kevent = *kev; 1842 kn->kn_kevent.flags &= ~(EV_ADD | EV_DELETE | 1843 EV_ENABLE | EV_DISABLE | EV_FORCEONESHOT); 1844 kn->kn_status = KN_DETACHED; 1845 if ((kev->flags & EV_DISABLE) != 0) 1846 kn->kn_status |= KN_DISABLED; 1847 kn_enter_flux(kn); 1848 1849 error = knote_attach(kn, kq); 1850 KQ_UNLOCK(kq); 1851 if (error != 0) { 1852 tkn = kn; 1853 goto done; 1854 } 1855 1856 /* 1857 * We transfer ownership of fops/fp to the knote 1858 * structure and avoid releasing them at the end of 1859 * this routine, now that all of the remaining exit 1860 * paths will knote_drop() to release the reference 1861 * counts we held on them above. 1862 */ 1863 fops = NULL; 1864 fp = NULL; 1865 1866 if ((error = kn->kn_fop->f_attach(kn)) != 0) { 1867 knote_drop_detached(kn, td); 1868 goto done; 1869 } 1870 knl = kn_list_lock(kn); 1871 goto done_ev_add; 1872 } else { 1873 /* No matching knote and the EV_ADD flag is not set. */ 1874 KQ_UNLOCK(kq); 1875 error = ENOENT; 1876 goto done; 1877 } 1878 } 1879 1880 if (kev->flags & EV_DELETE) { 1881 kn_enter_flux(kn); 1882 KQ_UNLOCK(kq); 1883 knote_drop(kn, td); 1884 goto done; 1885 } 1886 1887 if (kev->flags & EV_FORCEONESHOT) { 1888 kn->kn_flags |= EV_ONESHOT; 1889 KNOTE_ACTIVATE(kn, 1); 1890 } 1891 1892 if ((kev->flags & EV_ENABLE) != 0) 1893 kn->kn_status &= ~KN_DISABLED; 1894 else if ((kev->flags & EV_DISABLE) != 0) 1895 kn->kn_status |= KN_DISABLED; 1896 1897 /* 1898 * The user may change some filter values after the initial EV_ADD, 1899 * but doing so will not reset any filter which has already been 1900 * triggered. 1901 */ 1902 kn->kn_status |= KN_SCAN; 1903 kn_enter_flux(kn); 1904 KQ_UNLOCK(kq); 1905 knl = kn_list_lock(kn); 1906 if ((kev->flags & EV_KEEPUDATA) == 0) 1907 kn->kn_kevent.udata = kev->udata; 1908 if (!fops->f_isfd && fops->f_touch != NULL) { 1909 fops->f_touch(kn, kev, EVENT_REGISTER); 1910 } else { 1911 kn->kn_sfflags = kev->fflags; 1912 kn->kn_sdata = kev->data; 1913 } 1914 1915 done_ev_add: 1916 /* 1917 * We can get here with kn->kn_knlist == NULL. This can happen when 1918 * the initial attach event decides that the event is "completed" 1919 * already, e.g., filt_procattach() is called on a zombie process. It 1920 * will call filt_proc() which will remove it from the list, and NULL 1921 * kn_knlist. 1922 * 1923 * KN_DISABLED will be stable while the knote is in flux, so the 1924 * unlocked read will not race with an update. 1925 */ 1926 if ((kn->kn_status & KN_DISABLED) == 0) 1927 event = kn->kn_fop->f_event(kn, 0); 1928 else 1929 event = 0; 1930 1931 KQ_LOCK(kq); 1932 if (event) 1933 kn->kn_status |= KN_ACTIVE; 1934 if ((kn->kn_status & (KN_ACTIVE | KN_DISABLED | KN_QUEUED)) == 1935 KN_ACTIVE) 1936 knote_enqueue(kn); 1937 kn->kn_status &= ~KN_SCAN; 1938 kn_leave_flux(kn); 1939 kn_list_unlock(knl); 1940 KQ_UNLOCK_FLUX(kq); 1941 1942 done: 1943 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 1944 if (filedesc_unlock) 1945 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1946 if (fp != NULL) 1947 fdrop(fp, td); 1948 knote_free(tkn); 1949 if (fops != NULL) 1950 kqueue_fo_release(filt); 1951 return (error); 1952 } 1953 1954 static int 1955 kqueue_acquire_ref(struct kqueue *kq) 1956 { 1957 KQ_LOCK(kq); 1958 if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) { 1959 KQ_UNLOCK(kq); 1960 return (EBADF); 1961 } 1962 kq->kq_refcnt++; 1963 KQ_UNLOCK(kq); 1964 return (0); 1965 } 1966 1967 static int 1968 kqueue_acquire(struct file *fp, struct kqueue **kqp) 1969 { 1970 struct kqueue *kq; 1971 int error; 1972 1973 kq = fp->f_data; 1974 if (fp->f_type != DTYPE_KQUEUE || kq == NULL) 1975 return (EINVAL); 1976 error = kqueue_acquire_ref(kq); 1977 if (error == 0) 1978 *kqp = kq; 1979 return (error); 1980 } 1981 1982 static void 1983 kqueue_release(struct kqueue *kq, int locked) 1984 { 1985 if (locked) 1986 KQ_OWNED(kq); 1987 else 1988 KQ_LOCK(kq); 1989 kq->kq_refcnt--; 1990 if (kq->kq_refcnt == 1) 1991 wakeup(&kq->kq_refcnt); 1992 if (!locked) 1993 KQ_UNLOCK(kq); 1994 } 1995 1996 static void 1997 ast_kqueue(struct thread *td, int tda __unused) 1998 { 1999 taskqueue_quiesce(taskqueue_kqueue_ctx); 2000 } 2001 2002 static void 2003 kqueue_schedtask(struct kqueue *kq) 2004 { 2005 KQ_OWNED(kq); 2006 KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN), 2007 ("scheduling kqueue task while draining")); 2008 2009 if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) { 2010 taskqueue_enqueue(taskqueue_kqueue_ctx, &kq->kq_task); 2011 kq->kq_state |= KQ_TASKSCHED; 2012 ast_sched(curthread, TDA_KQUEUE); 2013 } 2014 } 2015 2016 /* 2017 * Expand the kq to make sure we have storage for fops/ident pair. 2018 * 2019 * Return 0 on success (or no work necessary), return errno on failure. 2020 */ 2021 static int 2022 kqueue_expand(struct kqueue *kq, const struct filterops *fops, uintptr_t ident, 2023 int mflag) 2024 { 2025 struct klist *list, *tmp_knhash, *to_free; 2026 u_long tmp_knhashmask; 2027 int error, fd, size; 2028 2029 KQ_NOTOWNED(kq); 2030 2031 error = 0; 2032 to_free = NULL; 2033 if (fops->f_isfd) { 2034 fd = ident; 2035 size = atomic_load_int(&kq->kq_knlistsize); 2036 if (size <= fd) { 2037 do { 2038 size += KQEXTENT; 2039 } while (size <= fd); 2040 list = malloc(size * sizeof(*list), M_KQUEUE, mflag); 2041 if (list == NULL) 2042 return ENOMEM; 2043 KQ_LOCK(kq); 2044 if ((kq->kq_state & KQ_CLOSING) != 0) { 2045 to_free = list; 2046 error = EBADF; 2047 } else if (kq->kq_knlistsize >= size) { 2048 to_free = list; 2049 } else { 2050 if (kq->kq_knlist != NULL) { 2051 bcopy(kq->kq_knlist, list, 2052 kq->kq_knlistsize * sizeof(*list)); 2053 to_free = kq->kq_knlist; 2054 kq->kq_knlist = NULL; 2055 } 2056 bzero((caddr_t)list + 2057 kq->kq_knlistsize * sizeof(*list), 2058 (size - kq->kq_knlistsize) * sizeof(*list)); 2059 kq->kq_knlistsize = size; 2060 kq->kq_knlist = list; 2061 } 2062 MPASS(error != 0 || kq->kq_knlistsize > fd); 2063 KQ_UNLOCK(kq); 2064 } 2065 } else { 2066 if (kq->kq_knhashmask == 0) { 2067 tmp_knhash = hashinit_flags(KN_HASHSIZE, M_KQUEUE, 2068 &tmp_knhashmask, (mflag & M_WAITOK) != 0 ? 2069 HASH_WAITOK : HASH_NOWAIT); 2070 if (tmp_knhash == NULL) 2071 return (ENOMEM); 2072 KQ_LOCK(kq); 2073 if ((kq->kq_state & KQ_CLOSING) != 0) { 2074 to_free = tmp_knhash; 2075 error = EBADF; 2076 } else if (kq->kq_knhashmask == 0) { 2077 kq->kq_knhash = tmp_knhash; 2078 kq->kq_knhashmask = tmp_knhashmask; 2079 } else { 2080 to_free = tmp_knhash; 2081 } 2082 KQ_UNLOCK(kq); 2083 } 2084 } 2085 free(to_free, M_KQUEUE); 2086 2087 KQ_NOTOWNED(kq); 2088 return (error); 2089 } 2090 2091 static void 2092 kqueue_task(void *arg, int pending) 2093 { 2094 struct kqueue *kq; 2095 int haskqglobal; 2096 2097 haskqglobal = 0; 2098 kq = arg; 2099 2100 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 2101 KQ_LOCK(kq); 2102 2103 KNOTE_LOCKED(&kq->kq_sel.si_note, 0); 2104 2105 kq->kq_state &= ~KQ_TASKSCHED; 2106 if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) { 2107 wakeup(&kq->kq_state); 2108 } 2109 KQ_UNLOCK(kq); 2110 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 2111 } 2112 2113 /* 2114 * Scan, update kn_data (if not ONESHOT), and copyout triggered events. 2115 * We treat KN_MARKER knotes as if they are in flux. 2116 */ 2117 static int 2118 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops, 2119 const struct timespec *tsp, struct kevent *keva, struct thread *td) 2120 { 2121 struct kevent *kevp; 2122 struct knote *kn, marker; 2123 struct knlist *knl; 2124 sbintime_t asbt, rsbt; 2125 int count, error, haskqglobal, influx, nkev, touch; 2126 2127 count = maxevents; 2128 nkev = 0; 2129 error = 0; 2130 haskqglobal = 0; 2131 2132 if (maxevents == 0) 2133 goto done_nl; 2134 if (maxevents < 0) { 2135 error = EINVAL; 2136 goto done_nl; 2137 } 2138 2139 rsbt = 0; 2140 if (tsp != NULL) { 2141 if (!timespecvalid_interval(tsp)) { 2142 error = EINVAL; 2143 goto done_nl; 2144 } 2145 if (timespecisset(tsp)) { 2146 if (tsp->tv_sec <= INT32_MAX) { 2147 rsbt = tstosbt(*tsp); 2148 if (TIMESEL(&asbt, rsbt)) 2149 asbt += tc_tick_sbt; 2150 if (asbt <= SBT_MAX - rsbt) 2151 asbt += rsbt; 2152 else 2153 asbt = 0; 2154 rsbt >>= tc_precexp; 2155 } else 2156 asbt = 0; 2157 } else 2158 asbt = -1; 2159 } else 2160 asbt = 0; 2161 memset(&marker, 0, sizeof(marker)); 2162 marker.kn_status = KN_MARKER; 2163 marker.kn_kq = kq; 2164 KQ_LOCK(kq); 2165 2166 retry: 2167 kevp = keva; 2168 if (kq->kq_count == 0) { 2169 if (asbt == -1) { 2170 error = EWOULDBLOCK; 2171 } else { 2172 kq->kq_state |= KQ_SLEEP; 2173 error = msleep_sbt(kq, &kq->kq_lock, PSOCK | PCATCH, 2174 "kqread", asbt, rsbt, C_ABSOLUTE); 2175 } 2176 if (error == 0) 2177 goto retry; 2178 /* don't restart after signals... */ 2179 if (error == ERESTART) 2180 error = EINTR; 2181 else if (error == EWOULDBLOCK) 2182 error = 0; 2183 goto done; 2184 } 2185 2186 TAILQ_INSERT_TAIL(&kq->kq_head, &marker, kn_tqe); 2187 influx = 0; 2188 while (count) { 2189 KQ_OWNED(kq); 2190 kn = TAILQ_FIRST(&kq->kq_head); 2191 2192 if ((kn->kn_status == KN_MARKER && kn != &marker) || 2193 kn_in_flux(kn)) { 2194 if (influx) { 2195 influx = 0; 2196 KQ_FLUX_WAKEUP(kq); 2197 } 2198 KQ_FLUX_SLEEP(kq, kn, 0); 2199 continue; 2200 } 2201 2202 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 2203 if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) { 2204 kn->kn_status &= ~KN_QUEUED; 2205 kq->kq_count--; 2206 continue; 2207 } 2208 if (kn == &marker) { 2209 KQ_FLUX_WAKEUP(kq); 2210 if (count == maxevents) 2211 goto retry; 2212 goto done; 2213 } 2214 KASSERT(!kn_in_flux(kn), 2215 ("knote %p is unexpectedly in flux", kn)); 2216 2217 if ((kn->kn_flags & EV_DROP) == EV_DROP) { 2218 kn->kn_status &= ~KN_QUEUED; 2219 kn_enter_flux(kn); 2220 kq->kq_count--; 2221 KQ_UNLOCK(kq); 2222 /* 2223 * We don't need to lock the list since we've 2224 * marked it as in flux. 2225 */ 2226 knote_drop(kn, td); 2227 KQ_LOCK(kq); 2228 continue; 2229 } else if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) { 2230 kn->kn_status &= ~KN_QUEUED; 2231 kn_enter_flux(kn); 2232 kq->kq_count--; 2233 KQ_UNLOCK(kq); 2234 /* 2235 * We don't need to lock the list since we've 2236 * marked the knote as being in flux. 2237 */ 2238 *kevp = kn->kn_kevent; 2239 knote_drop(kn, td); 2240 KQ_LOCK(kq); 2241 kn = NULL; 2242 } else { 2243 kn->kn_status |= KN_SCAN; 2244 kn_enter_flux(kn); 2245 KQ_UNLOCK(kq); 2246 if ((kn->kn_status & KN_KQUEUE) == KN_KQUEUE) 2247 KQ_GLOBAL_LOCK(&kq_global, haskqglobal); 2248 knl = kn_list_lock(kn); 2249 if (kn->kn_fop->f_event(kn, 0) == 0) { 2250 KQ_LOCK(kq); 2251 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 2252 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE | 2253 KN_SCAN); 2254 kn_leave_flux(kn); 2255 kq->kq_count--; 2256 kn_list_unlock(knl); 2257 influx = 1; 2258 continue; 2259 } 2260 touch = (!kn->kn_fop->f_isfd && 2261 kn->kn_fop->f_touch != NULL); 2262 if (touch) 2263 kn->kn_fop->f_touch(kn, kevp, EVENT_PROCESS); 2264 else 2265 *kevp = kn->kn_kevent; 2266 KQ_LOCK(kq); 2267 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal); 2268 if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) { 2269 /* 2270 * Manually clear knotes who weren't 2271 * 'touch'ed. 2272 */ 2273 if (touch == 0 && kn->kn_flags & EV_CLEAR) { 2274 kn->kn_data = 0; 2275 kn->kn_fflags = 0; 2276 } 2277 if (kn->kn_flags & EV_DISPATCH) 2278 kn->kn_status |= KN_DISABLED; 2279 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 2280 kq->kq_count--; 2281 } else 2282 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2283 2284 kn->kn_status &= ~KN_SCAN; 2285 kn_leave_flux(kn); 2286 kn_list_unlock(knl); 2287 influx = 1; 2288 } 2289 2290 /* we are returning a copy to the user */ 2291 kevp++; 2292 nkev++; 2293 count--; 2294 2295 if (nkev == KQ_NEVENTS) { 2296 influx = 0; 2297 KQ_UNLOCK_FLUX(kq); 2298 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 2299 nkev = 0; 2300 kevp = keva; 2301 KQ_LOCK(kq); 2302 if (error) 2303 break; 2304 } 2305 } 2306 TAILQ_REMOVE(&kq->kq_head, &marker, kn_tqe); 2307 done: 2308 KQ_OWNED(kq); 2309 KQ_UNLOCK_FLUX(kq); 2310 done_nl: 2311 KQ_NOTOWNED(kq); 2312 if (nkev != 0) 2313 error = k_ops->k_copyout(k_ops->arg, keva, nkev); 2314 td->td_retval[0] = maxevents - count; 2315 return (error); 2316 } 2317 2318 /*ARGSUSED*/ 2319 static int 2320 kqueue_ioctl(struct file *fp, u_long cmd, void *data, 2321 struct ucred *active_cred, struct thread *td) 2322 { 2323 /* 2324 * Enabling sigio causes two major problems: 2325 * 1) infinite recursion: 2326 * Synopsys: kevent is being used to track signals and have FIOASYNC 2327 * set. On receipt of a signal this will cause a kqueue to recurse 2328 * into itself over and over. Sending the sigio causes the kqueue 2329 * to become ready, which in turn posts sigio again, forever. 2330 * Solution: this can be solved by setting a flag in the kqueue that 2331 * we have a SIGIO in progress. 2332 * 2) locking problems: 2333 * Synopsys: Kqueue is a leaf subsystem, but adding signalling puts 2334 * us above the proc and pgrp locks. 2335 * Solution: Post a signal using an async mechanism, being sure to 2336 * record a generation count in the delivery so that we do not deliver 2337 * a signal to the wrong process. 2338 * 2339 * Note, these two mechanisms are somewhat mutually exclusive! 2340 */ 2341 #if 0 2342 struct kqueue *kq; 2343 2344 kq = fp->f_data; 2345 switch (cmd) { 2346 case FIOASYNC: 2347 if (*(int *)data) { 2348 kq->kq_state |= KQ_ASYNC; 2349 } else { 2350 kq->kq_state &= ~KQ_ASYNC; 2351 } 2352 return (0); 2353 2354 case FIOSETOWN: 2355 return (fsetown(*(int *)data, &kq->kq_sigio)); 2356 2357 case FIOGETOWN: 2358 *(int *)data = fgetown(&kq->kq_sigio); 2359 return (0); 2360 } 2361 #endif 2362 2363 return (ENOTTY); 2364 } 2365 2366 /*ARGSUSED*/ 2367 static int 2368 kqueue_poll(struct file *fp, int events, struct ucred *active_cred, 2369 struct thread *td) 2370 { 2371 struct kqueue *kq; 2372 int revents = 0; 2373 int error; 2374 2375 if ((error = kqueue_acquire(fp, &kq))) 2376 return POLLERR; 2377 2378 KQ_LOCK(kq); 2379 if (events & (POLLIN | POLLRDNORM)) { 2380 if (kq->kq_count) { 2381 revents |= events & (POLLIN | POLLRDNORM); 2382 } else { 2383 selrecord(td, &kq->kq_sel); 2384 if (SEL_WAITING(&kq->kq_sel)) 2385 kq->kq_state |= KQ_SEL; 2386 } 2387 } 2388 kqueue_release(kq, 1); 2389 KQ_UNLOCK(kq); 2390 return (revents); 2391 } 2392 2393 /*ARGSUSED*/ 2394 static int 2395 kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred) 2396 { 2397 2398 bzero((void *)st, sizeof *st); 2399 /* 2400 * We no longer return kq_count because the unlocked value is useless. 2401 * If you spent all this time getting the count, why not spend your 2402 * syscall better by calling kevent? 2403 * 2404 * XXX - This is needed for libc_r. 2405 */ 2406 st->st_mode = S_IFIFO; 2407 return (0); 2408 } 2409 2410 static void 2411 kqueue_drain(struct kqueue *kq, struct thread *td) 2412 { 2413 struct knote *kn; 2414 int i; 2415 2416 KQ_LOCK(kq); 2417 2418 KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING, 2419 ("kqueue already closing")); 2420 kq->kq_state |= KQ_CLOSING; 2421 if (kq->kq_refcnt > 1) 2422 msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0); 2423 2424 KASSERT(kq->kq_refcnt == 1, ("other refs are out there!")); 2425 2426 KASSERT(knlist_empty(&kq->kq_sel.si_note), 2427 ("kqueue's knlist not empty")); 2428 2429 for (i = 0; i < kq->kq_knlistsize; i++) { 2430 while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) { 2431 if (kn_in_flux(kn)) { 2432 KQ_FLUX_SLEEP_WMESG(kq, kn, 0, "kqclo1"); 2433 continue; 2434 } 2435 kn_enter_flux(kn); 2436 KQ_UNLOCK(kq); 2437 knote_drop(kn, td); 2438 KQ_LOCK(kq); 2439 } 2440 } 2441 if (kq->kq_knhashmask != 0) { 2442 for (i = 0; i <= kq->kq_knhashmask; i++) { 2443 while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) { 2444 if (kn_in_flux(kn)) { 2445 KQ_FLUX_SLEEP_WMESG(kq, kn, 0, 2446 "kqclo2"); 2447 continue; 2448 } 2449 kn_enter_flux(kn); 2450 KQ_UNLOCK(kq); 2451 knote_drop(kn, td); 2452 KQ_LOCK(kq); 2453 } 2454 } 2455 } 2456 2457 if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) { 2458 kq->kq_state |= KQ_TASKDRAIN; 2459 msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0); 2460 } 2461 2462 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2463 selwakeuppri(&kq->kq_sel, PSOCK); 2464 if (!SEL_WAITING(&kq->kq_sel)) 2465 kq->kq_state &= ~KQ_SEL; 2466 } 2467 2468 KQ_UNLOCK(kq); 2469 } 2470 2471 static void 2472 kqueue_destroy(struct kqueue *kq) 2473 { 2474 2475 KASSERT(kq->kq_fdp == NULL, 2476 ("kqueue still attached to a file descriptor")); 2477 seldrain(&kq->kq_sel); 2478 knlist_destroy(&kq->kq_sel.si_note); 2479 mtx_destroy(&kq->kq_lock); 2480 2481 if (kq->kq_knhash != NULL) 2482 free(kq->kq_knhash, M_KQUEUE); 2483 if (kq->kq_knlist != NULL) 2484 free(kq->kq_knlist, M_KQUEUE); 2485 2486 funsetown(&kq->kq_sigio); 2487 } 2488 2489 /*ARGSUSED*/ 2490 static int 2491 kqueue_close(struct file *fp, struct thread *td) 2492 { 2493 struct kqueue *kq = fp->f_data; 2494 struct filedesc *fdp; 2495 int error; 2496 int filedesc_unlock; 2497 2498 if ((error = kqueue_acquire(fp, &kq))) 2499 return error; 2500 kqueue_drain(kq, td); 2501 2502 /* 2503 * We could be called due to the knote_drop() doing fdrop(), 2504 * called from kqueue_register(). In this case the global 2505 * lock is owned, and filedesc sx is locked before, to not 2506 * take the sleepable lock after non-sleepable. 2507 */ 2508 fdp = kq->kq_fdp; 2509 kq->kq_fdp = NULL; 2510 if (!sx_xlocked(FILEDESC_LOCK(fdp))) { 2511 FILEDESC_XLOCK(fdp); 2512 filedesc_unlock = 1; 2513 } else 2514 filedesc_unlock = 0; 2515 TAILQ_REMOVE(&fdp->fd_kqlist, kq, kq_list); 2516 if (filedesc_unlock) 2517 FILEDESC_XUNLOCK(fdp); 2518 2519 kqueue_destroy(kq); 2520 chgkqcnt(kq->kq_cred->cr_ruidinfo, -1, 0); 2521 crfree(kq->kq_cred); 2522 free(kq, M_KQUEUE); 2523 fp->f_data = NULL; 2524 2525 return (0); 2526 } 2527 2528 static int 2529 kqueue_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 2530 { 2531 struct kqueue *kq = fp->f_data; 2532 2533 kif->kf_type = KF_TYPE_KQUEUE; 2534 kif->kf_un.kf_kqueue.kf_kqueue_addr = (uintptr_t)kq; 2535 kif->kf_un.kf_kqueue.kf_kqueue_count = kq->kq_count; 2536 kif->kf_un.kf_kqueue.kf_kqueue_state = kq->kq_state; 2537 return (0); 2538 } 2539 2540 static void 2541 kqueue_wakeup(struct kqueue *kq) 2542 { 2543 KQ_OWNED(kq); 2544 2545 if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) { 2546 kq->kq_state &= ~KQ_SLEEP; 2547 wakeup(kq); 2548 } 2549 if ((kq->kq_state & KQ_SEL) == KQ_SEL) { 2550 selwakeuppri(&kq->kq_sel, PSOCK); 2551 if (!SEL_WAITING(&kq->kq_sel)) 2552 kq->kq_state &= ~KQ_SEL; 2553 } 2554 if (!knlist_empty(&kq->kq_sel.si_note)) 2555 kqueue_schedtask(kq); 2556 if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) { 2557 pgsigio(&kq->kq_sigio, SIGIO, 0); 2558 } 2559 } 2560 2561 /* 2562 * Walk down a list of knotes, activating them if their event has triggered. 2563 * 2564 * There is a possibility to optimize in the case of one kq watching another. 2565 * Instead of scheduling a task to wake it up, you could pass enough state 2566 * down the chain to make up the parent kqueue. Make this code functional 2567 * first. 2568 */ 2569 void 2570 knote(struct knlist *list, long hint, int lockflags) 2571 { 2572 struct kqueue *kq; 2573 struct knote *kn, *tkn; 2574 int error; 2575 2576 if (list == NULL) 2577 return; 2578 2579 KNL_ASSERT_LOCK(list, lockflags & KNF_LISTLOCKED); 2580 2581 if ((lockflags & KNF_LISTLOCKED) == 0) 2582 list->kl_lock(list->kl_lockarg); 2583 2584 /* 2585 * If we unlock the list lock (and enter influx), we can 2586 * eliminate the kqueue scheduling, but this will introduce 2587 * four lock/unlock's for each knote to test. Also, marker 2588 * would be needed to keep iteration position, since filters 2589 * or other threads could remove events. 2590 */ 2591 SLIST_FOREACH_SAFE(kn, &list->kl_list, kn_selnext, tkn) { 2592 kq = kn->kn_kq; 2593 KQ_LOCK(kq); 2594 if (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0) { 2595 /* 2596 * Do not process the influx notes, except for 2597 * the influx coming from the kq unlock in the 2598 * kqueue_scan(). In the later case, we do 2599 * not interfere with the scan, since the code 2600 * fragment in kqueue_scan() locks the knlist, 2601 * and cannot proceed until we finished. 2602 */ 2603 KQ_UNLOCK(kq); 2604 } else if ((lockflags & KNF_NOKQLOCK) != 0) { 2605 kn_enter_flux(kn); 2606 KQ_UNLOCK(kq); 2607 error = kn->kn_fop->f_event(kn, hint); 2608 KQ_LOCK(kq); 2609 kn_leave_flux(kn); 2610 if (error) 2611 KNOTE_ACTIVATE(kn, 1); 2612 KQ_UNLOCK_FLUX(kq); 2613 } else { 2614 if (kn->kn_fop->f_event(kn, hint)) 2615 KNOTE_ACTIVATE(kn, 1); 2616 KQ_UNLOCK(kq); 2617 } 2618 } 2619 if ((lockflags & KNF_LISTLOCKED) == 0) 2620 list->kl_unlock(list->kl_lockarg); 2621 } 2622 2623 /* 2624 * add a knote to a knlist 2625 */ 2626 void 2627 knlist_add(struct knlist *knl, struct knote *kn, int islocked) 2628 { 2629 2630 KNL_ASSERT_LOCK(knl, islocked); 2631 KQ_NOTOWNED(kn->kn_kq); 2632 KASSERT(kn_in_flux(kn), ("knote %p not in flux", kn)); 2633 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2634 ("knote %p was not detached", kn)); 2635 KASSERT(kn->kn_knlist == NULL, 2636 ("knote %p was already on knlist %p", kn, kn->kn_knlist)); 2637 if (!islocked) 2638 knl->kl_lock(knl->kl_lockarg); 2639 SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext); 2640 if (!islocked) 2641 knl->kl_unlock(knl->kl_lockarg); 2642 KQ_LOCK(kn->kn_kq); 2643 kn->kn_knlist = knl; 2644 kn->kn_status &= ~KN_DETACHED; 2645 KQ_UNLOCK(kn->kn_kq); 2646 } 2647 2648 static void 2649 knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked, 2650 int kqislocked) 2651 { 2652 2653 KASSERT(!kqislocked || knlislocked, ("kq locked w/o knl locked")); 2654 KNL_ASSERT_LOCK(knl, knlislocked); 2655 mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED); 2656 KASSERT(kqislocked || kn_in_flux(kn), ("knote %p not in flux", kn)); 2657 KASSERT((kn->kn_status & KN_DETACHED) == 0, 2658 ("knote %p was already detached", kn)); 2659 KASSERT(kn->kn_knlist == knl, 2660 ("knote %p was not on knlist %p", kn, knl)); 2661 if (!knlislocked) 2662 knl->kl_lock(knl->kl_lockarg); 2663 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext); 2664 kn->kn_knlist = NULL; 2665 if (!knlislocked) 2666 kn_list_unlock(knl); 2667 if (!kqislocked) 2668 KQ_LOCK(kn->kn_kq); 2669 kn->kn_status |= KN_DETACHED; 2670 if (!kqislocked) 2671 KQ_UNLOCK(kn->kn_kq); 2672 } 2673 2674 /* 2675 * remove knote from the specified knlist 2676 */ 2677 void 2678 knlist_remove(struct knlist *knl, struct knote *kn, int islocked) 2679 { 2680 2681 knlist_remove_kq(knl, kn, islocked, 0); 2682 } 2683 2684 int 2685 knlist_empty(struct knlist *knl) 2686 { 2687 2688 KNL_ASSERT_LOCKED(knl); 2689 return (SLIST_EMPTY(&knl->kl_list)); 2690 } 2691 2692 static struct mtx knlist_lock; 2693 MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects", 2694 MTX_DEF); 2695 static void knlist_mtx_lock(void *arg); 2696 static void knlist_mtx_unlock(void *arg); 2697 2698 static void 2699 knlist_mtx_lock(void *arg) 2700 { 2701 2702 mtx_lock((struct mtx *)arg); 2703 } 2704 2705 static void 2706 knlist_mtx_unlock(void *arg) 2707 { 2708 2709 mtx_unlock((struct mtx *)arg); 2710 } 2711 2712 static void 2713 knlist_mtx_assert_lock(void *arg, int what) 2714 { 2715 2716 if (what == LA_LOCKED) 2717 mtx_assert((struct mtx *)arg, MA_OWNED); 2718 else 2719 mtx_assert((struct mtx *)arg, MA_NOTOWNED); 2720 } 2721 2722 void 2723 knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *), 2724 void (*kl_unlock)(void *), 2725 void (*kl_assert_lock)(void *, int)) 2726 { 2727 2728 if (lock == NULL) 2729 knl->kl_lockarg = &knlist_lock; 2730 else 2731 knl->kl_lockarg = lock; 2732 2733 if (kl_lock == NULL) 2734 knl->kl_lock = knlist_mtx_lock; 2735 else 2736 knl->kl_lock = kl_lock; 2737 if (kl_unlock == NULL) 2738 knl->kl_unlock = knlist_mtx_unlock; 2739 else 2740 knl->kl_unlock = kl_unlock; 2741 if (kl_assert_lock == NULL) 2742 knl->kl_assert_lock = knlist_mtx_assert_lock; 2743 else 2744 knl->kl_assert_lock = kl_assert_lock; 2745 2746 knl->kl_autodestroy = 0; 2747 SLIST_INIT(&knl->kl_list); 2748 } 2749 2750 void 2751 knlist_init_mtx(struct knlist *knl, struct mtx *lock) 2752 { 2753 2754 knlist_init(knl, lock, NULL, NULL, NULL); 2755 } 2756 2757 struct knlist * 2758 knlist_alloc(struct mtx *lock) 2759 { 2760 struct knlist *knl; 2761 2762 knl = malloc(sizeof(struct knlist), M_KQUEUE, M_WAITOK); 2763 knlist_init_mtx(knl, lock); 2764 return (knl); 2765 } 2766 2767 void 2768 knlist_destroy(struct knlist *knl) 2769 { 2770 2771 KASSERT(KNLIST_EMPTY(knl), 2772 ("destroying knlist %p with knotes on it", knl)); 2773 } 2774 2775 void 2776 knlist_detach(struct knlist *knl) 2777 { 2778 2779 KNL_ASSERT_LOCKED(knl); 2780 knl->kl_autodestroy = 1; 2781 if (knlist_empty(knl)) { 2782 knlist_destroy(knl); 2783 free(knl, M_KQUEUE); 2784 } 2785 } 2786 2787 /* 2788 * Even if we are locked, we may need to drop the lock to allow any influx 2789 * knotes time to "settle". 2790 */ 2791 void 2792 knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn) 2793 { 2794 struct knote *kn, *kn2; 2795 struct kqueue *kq; 2796 bool dropped; 2797 2798 KASSERT(!knl->kl_autodestroy, ("cleardel for autodestroy %p", knl)); 2799 if (islocked) 2800 KNL_ASSERT_LOCKED(knl); 2801 else { 2802 KNL_ASSERT_UNLOCKED(knl); 2803 knl->kl_lock(knl->kl_lockarg); 2804 } 2805 2806 for (;;) { 2807 /* 2808 * Each pass removes as many knotes as we can before dropping 2809 * into FLUXWAIT. Active knotes are simply detached and either 2810 * freed or converted to one-shot, as the attached subject is 2811 * essentially disappearing. 2812 */ 2813 dropped = false; 2814 SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) { 2815 kq = kn->kn_kq; 2816 KQ_LOCK(kq); 2817 if (kn_in_flux(kn)) { 2818 KQ_UNLOCK(kq); 2819 continue; 2820 } 2821 knlist_remove_kq(knl, kn, 1, 1); 2822 if (killkn) { 2823 kn_enter_flux(kn); 2824 KQ_UNLOCK(kq); 2825 knl->kl_unlock(knl->kl_lockarg); 2826 knote_drop_detached(kn, td); 2827 knl->kl_lock(knl->kl_lockarg); 2828 dropped = true; 2829 break; 2830 } else { 2831 /* Make sure cleared knotes disappear soon */ 2832 kn->kn_flags |= EV_EOF | EV_ONESHOT; 2833 KQ_UNLOCK(kq); 2834 } 2835 kq = NULL; 2836 } 2837 if (dropped) 2838 continue; 2839 2840 if (SLIST_EMPTY(&knl->kl_list)) 2841 break; 2842 2843 /* there are still in flux knotes remaining */ 2844 kn = SLIST_FIRST(&knl->kl_list); 2845 kq = kn->kn_kq; 2846 KQ_LOCK(kq); 2847 KASSERT(kn_in_flux(kn), ("knote removed w/o list lock")); 2848 knl->kl_unlock(knl->kl_lockarg); 2849 KQ_FLUX_SLEEP_WMESG(kq, kn, PDROP, "kqkclr"); 2850 kq = NULL; 2851 knl->kl_lock(knl->kl_lockarg); 2852 } 2853 2854 if (islocked) 2855 KNL_ASSERT_LOCKED(knl); 2856 else { 2857 knl->kl_unlock(knl->kl_lockarg); 2858 KNL_ASSERT_UNLOCKED(knl); 2859 } 2860 } 2861 2862 /* 2863 * Remove all knotes referencing a specified fd must be called with FILEDESC 2864 * lock. This prevents a race where a new fd comes along and occupies the 2865 * entry and we attach a knote to the fd. 2866 */ 2867 void 2868 knote_fdclose(struct thread *td, int fd) 2869 { 2870 struct filedesc *fdp = td->td_proc->p_fd; 2871 struct kqueue *kq; 2872 struct knote *kn; 2873 2874 FILEDESC_XLOCK_ASSERT(fdp); 2875 2876 /* 2877 * We shouldn't have to worry about new kevents appearing on fd 2878 * since filedesc is locked. 2879 */ 2880 TAILQ_FOREACH(kq, &fdp->fd_kqlist, kq_list) { 2881 KQ_LOCK(kq); 2882 if (kq->kq_knlistsize <= fd || 2883 SLIST_EMPTY(&kq->kq_knlist[fd])) { 2884 KQ_UNLOCK(kq); 2885 continue; 2886 } 2887 2888 while ((kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) { 2889 if (kn_in_flux(kn)) { 2890 /* 2891 * Wait for this knote to stabilize, it could be 2892 * the case that it's in the process of being 2893 * dropped anyways. 2894 */ 2895 KQ_FLUX_SLEEP(kq, kn, 0); 2896 continue; 2897 } 2898 kn_enter_flux(kn); 2899 KQ_UNLOCK(kq); 2900 knote_drop(kn, td); 2901 KQ_LOCK(kq); 2902 } 2903 KQ_UNLOCK_FLUX(kq); 2904 } 2905 } 2906 2907 static int 2908 knote_attach(struct knote *kn, struct kqueue *kq) 2909 { 2910 struct klist *list; 2911 2912 KASSERT(kn_in_flux(kn), ("knote %p not marked influx", kn)); 2913 KQ_OWNED(kq); 2914 MPASS(kn->kn_kq == kq); 2915 2916 if ((kq->kq_state & KQ_CLOSING) != 0) 2917 return (EBADF); 2918 if (kn->kn_fop->f_isfd) { 2919 if (kn->kn_id >= kq->kq_knlistsize) 2920 return (ENOMEM); 2921 list = &kq->kq_knlist[kn->kn_id]; 2922 } else { 2923 if (kq->kq_knhash == NULL) 2924 return (ENOMEM); 2925 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2926 } 2927 SLIST_INSERT_HEAD(list, kn, kn_link); 2928 return (0); 2929 } 2930 2931 static void 2932 knote_drop(struct knote *kn, struct thread *td) 2933 { 2934 2935 if ((kn->kn_status & KN_DETACHED) == 0) 2936 kn->kn_fop->f_detach(kn); 2937 knote_drop_detached(kn, td); 2938 } 2939 2940 static void 2941 knote_drop_detached(struct knote *kn, struct thread *td) 2942 { 2943 struct kqueue *kq; 2944 struct klist *list; 2945 2946 kq = kn->kn_kq; 2947 2948 KASSERT((kn->kn_status & KN_DETACHED) != 0, 2949 ("knote %p still attached", kn)); 2950 KQ_NOTOWNED(kq); 2951 2952 KQ_LOCK(kq); 2953 for (;;) { 2954 KASSERT(kn->kn_influx >= 1, 2955 ("knote_drop called on %p with influx %d", 2956 kn, kn->kn_influx)); 2957 if (kn->kn_influx == 1) 2958 break; 2959 KQ_FLUX_SLEEP(kq, kn, 0); 2960 } 2961 2962 MPASS(kn->kn_kq == kq); 2963 if (kn->kn_fop->f_isfd) 2964 list = &kq->kq_knlist[kn->kn_id]; 2965 else 2966 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; 2967 2968 SLIST_REMOVE(list, kn, knote, kn_link); 2969 if (kn->kn_status & KN_QUEUED) 2970 knote_dequeue(kn); 2971 KQ_UNLOCK_FLUX(kq); 2972 2973 if (kn->kn_fop->f_isfd) { 2974 fdrop(kn->kn_fp, td); 2975 kn->kn_fp = NULL; 2976 } 2977 kqueue_fo_release(kn->kn_kevent.filter); 2978 kn->kn_fop = NULL; 2979 knote_free(kn); 2980 } 2981 2982 static void 2983 knote_enqueue(struct knote *kn) 2984 { 2985 struct kqueue *kq = kn->kn_kq; 2986 2987 KQ_OWNED(kn->kn_kq); 2988 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 2989 2990 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 2991 kn->kn_status |= KN_QUEUED; 2992 kq->kq_count++; 2993 kqueue_wakeup(kq); 2994 } 2995 2996 static void 2997 knote_dequeue(struct knote *kn) 2998 { 2999 struct kqueue *kq = kn->kn_kq; 3000 3001 KQ_OWNED(kn->kn_kq); 3002 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 3003 3004 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 3005 kn->kn_status &= ~KN_QUEUED; 3006 kq->kq_count--; 3007 } 3008 3009 static void 3010 knote_init(void *dummy __unused) 3011 { 3012 3013 knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL, 3014 NULL, NULL, UMA_ALIGN_PTR, 0); 3015 ast_register(TDA_KQUEUE, ASTR_ASTF_REQUIRED, 0, ast_kqueue); 3016 prison0.pr_klist = knlist_alloc(&prison0.pr_mtx); 3017 } 3018 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL); 3019 3020 static struct knote * 3021 knote_alloc(int mflag) 3022 { 3023 3024 return (uma_zalloc(knote_zone, mflag | M_ZERO)); 3025 } 3026 3027 static void 3028 knote_free(struct knote *kn) 3029 { 3030 3031 uma_zfree(knote_zone, kn); 3032 } 3033 3034 /* 3035 * Register the kev w/ the kq specified by fd. 3036 */ 3037 int 3038 kqfd_register(int fd, struct kevent *kev, struct thread *td, int mflag) 3039 { 3040 struct kqueue *kq; 3041 struct file *fp; 3042 cap_rights_t rights; 3043 int error; 3044 3045 error = fget(td, fd, cap_rights_init_one(&rights, CAP_KQUEUE_CHANGE), 3046 &fp); 3047 if (error != 0) 3048 return (error); 3049 if ((error = kqueue_acquire(fp, &kq)) != 0) 3050 goto noacquire; 3051 3052 error = kqueue_register(kq, kev, td, mflag); 3053 kqueue_release(kq, 0); 3054 3055 noacquire: 3056 fdrop(fp, td); 3057 return (error); 3058 } 3059 3060 static int 3061 kqueue_fork_alloc(struct filedesc *fdp, struct file *fp, struct file **fp1, 3062 struct thread *td) 3063 { 3064 struct kqueue *kq, *kq1; 3065 int error; 3066 3067 MPASS(fp->f_type == DTYPE_KQUEUE); 3068 kq = fp->f_data; 3069 if ((kq->kq_state & KQ_CPONFORK) == 0) 3070 return (EOPNOTSUPP); 3071 error = kqueue_acquire_ref(kq); 3072 if (error != 0) 3073 return (error); 3074 error = kern_kqueue_alloc(td, fdp, NULL, fp1, 0, NULL, true, &kq1); 3075 if (error == 0) { 3076 kq1->kq_forksrc = kq; 3077 (*fp1)->f_flag = fp->f_flag & (FREAD | FWRITE | FEXEC | 3078 O_CLOEXEC | O_CLOFORK); 3079 } else { 3080 kqueue_release(kq, 0); 3081 } 3082 return (error); 3083 } 3084 3085 static void 3086 kqueue_fork_copy_knote(struct kqueue *kq, struct kqueue *kq1, struct knote *kn, 3087 struct proc *p1, struct filedesc *fdp) 3088 { 3089 struct knote *kn1; 3090 struct knlist *knl; 3091 const struct filterops *fop; 3092 int error; 3093 bool enqueue; 3094 3095 KASSERT(kn->kn_influx != 0, 3096 ("%s: knote %p not in flux", __func__, kn)); 3097 KASSERT((kn->kn_status & KN_DETACHED) == 0, 3098 ("%s: knote %p not detached", __func__, kn)); 3099 KASSERT((kn->kn_status & KN_MARKER) == 0, 3100 ("%s: knote %p not detached", __func__, kn)); 3101 3102 if ((kn->kn_status & KN_KQUEUE) != 0) { 3103 /* 3104 * We cannot hold references to a kqueue outside of the process 3105 * itself, kqueue_close() does not handle this possibility. 3106 */ 3107 return; 3108 } 3109 fop = kn->kn_fop; 3110 if (fop->f_copy == NULL || (fop->f_isfd && 3111 ((unsigned int)fdp->fd_files->fdt_nfiles <= kn->kn_kevent.ident || 3112 fdp->fd_files->fdt_ofiles[kn->kn_kevent.ident].fde_file == NULL))) 3113 return; 3114 error = kqueue_expand(kq1, fop, kn->kn_kevent.ident, M_WAITOK); 3115 if (error != 0) 3116 return; 3117 3118 kn1 = knote_alloc(M_WAITOK); 3119 3120 knl = kn_list_lock(kn); 3121 KQ_LOCK(kq); 3122 *kn1 = *kn; 3123 KQ_UNLOCK(kq); 3124 kn_list_unlock(knl); 3125 kn1->kn_status = KN_DETACHED | (kn1->kn_status & KN_CPONFORK); 3126 kn1->kn_kq = kq1; 3127 kn1->kn_knlist = NULL; 3128 error = fop->f_copy(kn1, p1); 3129 if (error != 0) { 3130 knote_free(kn1); 3131 return; 3132 } 3133 (void)kqueue_fo_find(kn->kn_kevent.filter); 3134 if (fop->f_isfd && !fhold(kn1->kn_fp)) { 3135 fop->f_detach(kn1); 3136 kqueue_fo_release(kn->kn_kevent.filter); 3137 knote_free(kn1); 3138 return; 3139 } 3140 if (kn->kn_knlist != NULL) { 3141 knl = kn_list_lock(kn); 3142 knlist_add(kn->kn_knlist, kn1, 1); 3143 } else { 3144 knl = NULL; 3145 } 3146 enqueue = kn->kn_fop->f_event(kn1, 0) != 0; 3147 kn_list_unlock(knl); 3148 3149 KQ_LOCK(kq1); 3150 knote_attach(kn1, kq1); 3151 kn1->kn_influx = 0; 3152 if (enqueue && (kn1->kn_status & KN_QUEUED) == 0) 3153 knote_enqueue(kn1); 3154 KQ_UNLOCK(kq1); 3155 } 3156 3157 static void 3158 kqueue_fork_copy_list(struct klist *knlist, struct knote *marker, 3159 struct kqueue *kq, struct kqueue *kq1, struct proc *p1, 3160 struct filedesc *fdp) 3161 { 3162 struct knote *kn; 3163 3164 KQ_OWNED(kq); 3165 kn = SLIST_FIRST(knlist); 3166 while (kn != NULL) { 3167 MPASS(kn->kn_kq == kq); 3168 if ((kn->kn_status & (KN_DETACHED | KN_MARKER)) != 0 || 3169 (kn_in_flux(kn) && (kn->kn_status & KN_SCAN) == 0)) { 3170 kn = SLIST_NEXT(kn, kn_link); 3171 continue; 3172 } 3173 kn_enter_flux(kn); 3174 SLIST_INSERT_AFTER(kn, marker, kn_link); 3175 KQ_UNLOCK(kq); 3176 kqueue_fork_copy_knote(kq, kq1, kn, p1, fdp); 3177 KQ_LOCK(kq); 3178 kn_leave_flux(kn); 3179 kn = SLIST_NEXT(marker, kn_link); 3180 /* XXXKIB switch kn_link to LIST? */ 3181 SLIST_REMOVE(knlist, marker, knote, kn_link); 3182 } 3183 } 3184 3185 static int 3186 kqueue_fork_copy(struct filedesc *fdp, struct file *fp, struct file *fp1, 3187 struct proc *p1, struct thread *td) 3188 { 3189 struct kqueue *kq, *kq1; 3190 struct knote marker; 3191 int error, i; 3192 3193 error = 0; 3194 MPASS(fp == NULL); 3195 MPASS(fp1->f_type == DTYPE_KQUEUE); 3196 3197 kq1 = fp1->f_data; 3198 kq = kq1->kq_forksrc; 3199 memset(&marker, 0, sizeof(marker)); 3200 marker.kn_status = KN_MARKER; 3201 marker.kn_kq = kq; 3202 3203 KQ_LOCK(kq); 3204 for (i = 0; i < kq->kq_knlistsize; i++) { 3205 kqueue_fork_copy_list(&kq->kq_knlist[i], &marker, kq, kq1, 3206 p1, fdp); 3207 } 3208 if (kq->kq_knhashmask != 0) { 3209 for (i = 0; i <= kq->kq_knhashmask; i++) { 3210 kqueue_fork_copy_list(&kq->kq_knhash[i], &marker, kq, 3211 kq1, p1, fdp); 3212 } 3213 } 3214 kqueue_release(kq, 1); 3215 kq1->kq_forksrc = NULL; 3216 KQ_UNLOCK_FLUX(kq); 3217 return (error); 3218 } 3219 3220 static int 3221 kqueue_fork(struct filedesc *fdp, struct file *fp, struct file **fp1, 3222 struct proc *p1, struct thread *td) 3223 { 3224 if (*fp1 == NULL) 3225 return (kqueue_fork_alloc(fdp, fp, fp1, td)); 3226 return (kqueue_fork_copy(fdp, fp, *fp1, p1, td)); 3227 } 3228 3229 int 3230 knote_triv_copy(struct knote *kn __unused, struct proc *p1 __unused) 3231 { 3232 return (0); 3233 } 3234 3235 struct knote_status_export_bit { 3236 int kn_status_bit; 3237 int knt_status_bit; 3238 }; 3239 3240 #define ST(name) \ 3241 { .kn_status_bit = KN_##name, .knt_status_bit = KNOTE_STATUS_##name } 3242 static const struct knote_status_export_bit knote_status_export_bits[] = { 3243 ST(ACTIVE), 3244 ST(QUEUED), 3245 ST(DISABLED), 3246 ST(DETACHED), 3247 ST(KQUEUE), 3248 }; 3249 #undef ST 3250 3251 static int 3252 knote_status_export(int kn_status) 3253 { 3254 const struct knote_status_export_bit *b; 3255 unsigned i; 3256 int res; 3257 3258 res = 0; 3259 for (i = 0; i < nitems(knote_status_export_bits); i++) { 3260 b = &knote_status_export_bits[i]; 3261 if ((kn_status & b->kn_status_bit) != 0) 3262 res |= b->knt_status_bit; 3263 } 3264 return (res); 3265 } 3266 3267 static int 3268 kern_proc_kqueue_report_one(struct sbuf *s, struct proc *p, 3269 int kq_fd, struct kqueue *kq, struct knote *kn, bool compat32 __unused) 3270 { 3271 struct kinfo_knote kin; 3272 #ifdef COMPAT_FREEBSD32 3273 struct kinfo_knote32 kin32; 3274 #endif 3275 int error; 3276 3277 if (kn->kn_status == KN_MARKER) 3278 return (0); 3279 3280 memset(&kin, 0, sizeof(kin)); 3281 kin.knt_kq_fd = kq_fd; 3282 memcpy(&kin.knt_event, &kn->kn_kevent, sizeof(struct kevent)); 3283 kin.knt_status = knote_status_export(kn->kn_status); 3284 kn_enter_flux(kn); 3285 KQ_UNLOCK_FLUX(kq); 3286 if (kn->kn_fop->f_userdump != NULL) 3287 (void)kn->kn_fop->f_userdump(p, kn, &kin); 3288 #ifdef COMPAT_FREEBSD32 3289 if (compat32) { 3290 freebsd32_kinfo_knote_to_32(&kin, &kin32); 3291 error = sbuf_bcat(s, &kin32, sizeof(kin32)); 3292 } else 3293 #endif 3294 error = sbuf_bcat(s, &kin, sizeof(kin)); 3295 KQ_LOCK(kq); 3296 kn_leave_flux(kn); 3297 return (error); 3298 } 3299 3300 static int 3301 kern_proc_kqueue_report(struct sbuf *s, struct proc *p, int kq_fd, 3302 struct kqueue *kq, bool compat32) 3303 { 3304 struct knote *kn; 3305 int error, i; 3306 3307 error = 0; 3308 KQ_LOCK(kq); 3309 for (i = 0; i < kq->kq_knlistsize; i++) { 3310 SLIST_FOREACH(kn, &kq->kq_knlist[i], kn_link) { 3311 MPASS(kn->kn_kq == kq); 3312 error = kern_proc_kqueue_report_one(s, p, kq_fd, 3313 kq, kn, compat32); 3314 if (error != 0) 3315 goto out; 3316 } 3317 } 3318 if (kq->kq_knhashmask == 0) 3319 goto out; 3320 for (i = 0; i <= kq->kq_knhashmask; i++) { 3321 SLIST_FOREACH(kn, &kq->kq_knhash[i], kn_link) { 3322 MPASS(kn->kn_kq == kq); 3323 error = kern_proc_kqueue_report_one(s, p, kq_fd, 3324 kq, kn, compat32); 3325 if (error != 0) 3326 goto out; 3327 } 3328 } 3329 out: 3330 KQ_UNLOCK_FLUX(kq); 3331 return (error); 3332 } 3333 3334 struct kern_proc_kqueues_out1_cb_args { 3335 struct sbuf *s; 3336 bool compat32; 3337 }; 3338 3339 static int 3340 kern_proc_kqueues_out1_cb(struct proc *p, int fd, struct file *fp, void *arg) 3341 { 3342 struct kqueue *kq; 3343 struct kern_proc_kqueues_out1_cb_args *a; 3344 3345 if (fp->f_type != DTYPE_KQUEUE) 3346 return (0); 3347 a = arg; 3348 kq = fp->f_data; 3349 return (kern_proc_kqueue_report(a->s, p, fd, kq, a->compat32)); 3350 } 3351 3352 static int 3353 kern_proc_kqueues_out1(struct thread *td, struct proc *p, struct sbuf *s, 3354 bool compat32) 3355 { 3356 struct kern_proc_kqueues_out1_cb_args a; 3357 3358 a.s = s; 3359 a.compat32 = compat32; 3360 return (fget_remote_foreach(td, p, kern_proc_kqueues_out1_cb, &a)); 3361 } 3362 3363 struct kern_proc_kqueues_drain_ctx { 3364 struct sbuf *sb; 3365 size_t remaining; 3366 bool full; 3367 }; 3368 3369 static int 3370 kern_proc_kqueues_drain(void *arg, const char *data, int len) 3371 { 3372 struct kern_proc_kqueues_drain_ctx *c; 3373 size_t n; 3374 3375 c = arg; 3376 n = MIN((size_t)len, c->remaining); 3377 if (n != 0) { 3378 if (sbuf_bcat(c->sb, data, n) != 0) 3379 return (-ENOMEM); 3380 c->remaining -= n; 3381 } 3382 if (c->remaining == 0) { 3383 c->full = true; 3384 return (-ENOSPC); 3385 } 3386 return (len); 3387 } 3388 3389 int 3390 kern_proc_kqueues_out(struct proc *p, struct sbuf *sb, size_t maxlen, 3391 bool compat32) 3392 { 3393 struct kern_proc_kqueues_drain_ctx c; 3394 struct sbuf *s, sm; 3395 int error; 3396 3397 if (maxlen == -1) 3398 return (kern_proc_kqueues_out1(curthread, p, sb, compat32)); 3399 3400 c.sb = sb; 3401 c.remaining = maxlen; 3402 c.full = false; 3403 s = sbuf_new(&sm, NULL, PAGE_SIZE, SBUF_FIXEDLEN); 3404 sbuf_set_drain(s, kern_proc_kqueues_drain, &c); 3405 error = kern_proc_kqueues_out1(curthread, p, s, compat32); 3406 sbuf_finish(s); 3407 sbuf_delete(s); 3408 if (c.full) 3409 error = 0; 3410 return (error); 3411 } 3412 3413 static int 3414 sysctl_kern_proc_kqueue_one(struct thread *td, struct sbuf *s, struct proc *p, 3415 int kq_fd, bool compat32) 3416 { 3417 struct file *fp; 3418 struct kqueue *kq; 3419 int error; 3420 3421 error = fget_remote(td, p, kq_fd, NULL, NULL, &fp); 3422 if (error == 0) { 3423 if (fp->f_type != DTYPE_KQUEUE) { 3424 error = EINVAL; 3425 } else { 3426 kq = fp->f_data; 3427 error = kern_proc_kqueue_report(s, p, kq_fd, kq, 3428 compat32); 3429 } 3430 fdrop(fp, td); 3431 } 3432 return (error); 3433 } 3434 3435 static int 3436 sysctl_kern_proc_kqueue(SYSCTL_HANDLER_ARGS) 3437 { 3438 struct thread *td; 3439 struct proc *p; 3440 struct sbuf *s, sm; 3441 int error, error1, *name; 3442 bool compat32; 3443 3444 name = (int *)arg1; 3445 if ((u_int)arg2 > 2 || (u_int)arg2 == 0) 3446 return (EINVAL); 3447 3448 td = curthread; 3449 #ifdef COMPAT_FREEBSD32 3450 compat32 = SV_CURPROC_FLAG(SV_ILP32); 3451 #else 3452 compat32 = false; 3453 #endif 3454 3455 error = pget((pid_t)name[0], PGET_NOTWEXIT, &p); 3456 if (error != 0) 3457 return (error); 3458 3459 _PHOLD(p); 3460 execve_block_wait(td, p); 3461 error = p_candebug(td, p); 3462 if (error != 0) 3463 goto out1; 3464 PROC_UNLOCK(p); 3465 3466 s = sbuf_new_for_sysctl(&sm, NULL, 0, req); 3467 if (s == NULL) { 3468 error = ENOMEM; 3469 goto out; 3470 } 3471 sbuf_clear_flags(s, SBUF_INCLUDENUL); 3472 3473 if ((u_int)arg2 == 1) { 3474 error = kern_proc_kqueues_out1(td, p, s, compat32); 3475 } else { 3476 error = sysctl_kern_proc_kqueue_one(td, s, p, 3477 name[1] /* kq_fd */, compat32); 3478 } 3479 3480 error1 = sbuf_finish(s); 3481 if (error == 0) 3482 error = error1; 3483 sbuf_delete(s); 3484 3485 out: 3486 PROC_LOCK(p); 3487 out1: 3488 execve_unblock(td, p); 3489 _PRELE(p); 3490 PROC_UNLOCK(p); 3491 return (error); 3492 } 3493 3494 static SYSCTL_NODE(_kern_proc, KERN_PROC_KQUEUE, kq, 3495 CTLFLAG_RD | CTLFLAG_MPSAFE, 3496 sysctl_kern_proc_kqueue, "KQueue events"); 3497