1 | /* $NetBSD: kern_event.c,v 1.88 2016/07/14 18:16:51 christos Exp $ */ |
2 | |
3 | /*- |
4 | * Copyright (c) 2008, 2009 The NetBSD Foundation, Inc. |
5 | * All rights reserved. |
6 | * |
7 | * This code is derived from software contributed to The NetBSD Foundation |
8 | * by Andrew Doran. |
9 | * |
10 | * Redistribution and use in source and binary forms, with or without |
11 | * modification, are permitted provided that the following conditions |
12 | * are met: |
13 | * 1. Redistributions of source code must retain the above copyright |
14 | * notice, this list of conditions and the following disclaimer. |
15 | * 2. Redistributions in binary form must reproduce the above copyright |
16 | * notice, this list of conditions and the following disclaimer in the |
17 | * documentation and/or other materials provided with the distribution. |
18 | * |
19 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
21 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
23 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
29 | * POSSIBILITY OF SUCH DAMAGE. |
30 | */ |
31 | |
32 | /*- |
33 | * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org> |
34 | * All rights reserved. |
35 | * |
36 | * Redistribution and use in source and binary forms, with or without |
37 | * modification, are permitted provided that the following conditions |
38 | * are met: |
39 | * 1. Redistributions of source code must retain the above copyright |
40 | * notice, this list of conditions and the following disclaimer. |
41 | * 2. Redistributions in binary form must reproduce the above copyright |
42 | * notice, this list of conditions and the following disclaimer in the |
43 | * documentation and/or other materials provided with the distribution. |
44 | * |
45 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
46 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
47 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
48 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
49 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
50 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
51 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
52 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
53 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
54 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
55 | * SUCH DAMAGE. |
56 | * |
57 | * FreeBSD: src/sys/kern/kern_event.c,v 1.27 2001/07/05 17:10:44 rwatson Exp |
58 | */ |
59 | |
60 | #include <sys/cdefs.h> |
61 | __KERNEL_RCSID(0, "$NetBSD: kern_event.c,v 1.88 2016/07/14 18:16:51 christos Exp $" ); |
62 | |
63 | #include <sys/param.h> |
64 | #include <sys/systm.h> |
65 | #include <sys/kernel.h> |
66 | #include <sys/wait.h> |
67 | #include <sys/proc.h> |
68 | #include <sys/file.h> |
69 | #include <sys/select.h> |
70 | #include <sys/queue.h> |
71 | #include <sys/event.h> |
72 | #include <sys/eventvar.h> |
73 | #include <sys/poll.h> |
74 | #include <sys/kmem.h> |
75 | #include <sys/stat.h> |
76 | #include <sys/filedesc.h> |
77 | #include <sys/syscallargs.h> |
78 | #include <sys/kauth.h> |
79 | #include <sys/conf.h> |
80 | #include <sys/atomic.h> |
81 | |
82 | static int kqueue_scan(file_t *, size_t, struct kevent *, |
83 | const struct timespec *, register_t *, |
84 | const struct kevent_ops *, struct kevent *, |
85 | size_t); |
86 | static int kqueue_ioctl(file_t *, u_long, void *); |
87 | static int kqueue_fcntl(file_t *, u_int, void *); |
88 | static int kqueue_poll(file_t *, int); |
89 | static int kqueue_kqfilter(file_t *, struct knote *); |
90 | static int kqueue_stat(file_t *, struct stat *); |
91 | static int kqueue_close(file_t *); |
92 | static int kqueue_register(struct kqueue *, struct kevent *); |
93 | static void kqueue_doclose(struct kqueue *, struct klist *, int); |
94 | |
95 | static void knote_detach(struct knote *, filedesc_t *fdp, bool); |
96 | static void knote_enqueue(struct knote *); |
97 | static void knote_activate(struct knote *); |
98 | |
99 | static void filt_kqdetach(struct knote *); |
100 | static int filt_kqueue(struct knote *, long hint); |
101 | static int filt_procattach(struct knote *); |
102 | static void filt_procdetach(struct knote *); |
103 | static int filt_proc(struct knote *, long hint); |
104 | static int filt_fileattach(struct knote *); |
105 | static void filt_timerexpire(void *x); |
106 | static int filt_timerattach(struct knote *); |
107 | static void filt_timerdetach(struct knote *); |
108 | static int filt_timer(struct knote *, long hint); |
109 | |
110 | static const struct fileops kqueueops = { |
111 | .fo_read = (void *)enxio, |
112 | .fo_write = (void *)enxio, |
113 | .fo_ioctl = kqueue_ioctl, |
114 | .fo_fcntl = kqueue_fcntl, |
115 | .fo_poll = kqueue_poll, |
116 | .fo_stat = kqueue_stat, |
117 | .fo_close = kqueue_close, |
118 | .fo_kqfilter = kqueue_kqfilter, |
119 | .fo_restart = fnullop_restart, |
120 | }; |
121 | |
122 | static const struct filterops kqread_filtops = |
123 | { 1, NULL, filt_kqdetach, filt_kqueue }; |
124 | static const struct filterops proc_filtops = |
125 | { 0, filt_procattach, filt_procdetach, filt_proc }; |
126 | static const struct filterops file_filtops = |
127 | { 1, filt_fileattach, NULL, NULL }; |
128 | static const struct filterops timer_filtops = |
129 | { 0, filt_timerattach, filt_timerdetach, filt_timer }; |
130 | |
131 | static u_int kq_ncallouts = 0; |
132 | static int kq_calloutmax = (4 * 1024); |
133 | |
134 | #define KN_HASHSIZE 64 /* XXX should be tunable */ |
135 | #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) |
136 | |
137 | extern const struct filterops sig_filtops; |
138 | |
139 | /* |
140 | * Table for for all system-defined filters. |
141 | * These should be listed in the numeric order of the EVFILT_* defines. |
142 | * If filtops is NULL, the filter isn't implemented in NetBSD. |
143 | * End of list is when name is NULL. |
144 | * |
145 | * Note that 'refcnt' is meaningless for built-in filters. |
146 | */ |
147 | struct kfilter { |
148 | const char *name; /* name of filter */ |
149 | uint32_t filter; /* id of filter */ |
150 | unsigned refcnt; /* reference count */ |
151 | const struct filterops *filtops;/* operations for filter */ |
152 | size_t namelen; /* length of name string */ |
153 | }; |
154 | |
155 | /* System defined filters */ |
156 | static struct kfilter sys_kfilters[] = { |
157 | { "EVFILT_READ" , EVFILT_READ, 0, &file_filtops, 0 }, |
158 | { "EVFILT_WRITE" , EVFILT_WRITE, 0, &file_filtops, 0, }, |
159 | { "EVFILT_AIO" , EVFILT_AIO, 0, NULL, 0 }, |
160 | { "EVFILT_VNODE" , EVFILT_VNODE, 0, &file_filtops, 0 }, |
161 | { "EVFILT_PROC" , EVFILT_PROC, 0, &proc_filtops, 0 }, |
162 | { "EVFILT_SIGNAL" , EVFILT_SIGNAL, 0, &sig_filtops, 0 }, |
163 | { "EVFILT_TIMER" , EVFILT_TIMER, 0, &timer_filtops, 0 }, |
164 | { NULL, 0, 0, NULL, 0 }, |
165 | }; |
166 | |
167 | /* User defined kfilters */ |
168 | static struct kfilter *user_kfilters; /* array */ |
169 | static int user_kfilterc; /* current offset */ |
170 | static int user_kfiltermaxc; /* max size so far */ |
171 | static size_t user_kfiltersz; /* size of allocated memory */ |
172 | |
173 | /* Locks */ |
174 | static krwlock_t kqueue_filter_lock; /* lock on filter lists */ |
175 | static kmutex_t kqueue_misc_lock; /* miscellaneous */ |
176 | |
177 | static kauth_listener_t kqueue_listener; |
178 | |
179 | static int |
180 | kqueue_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie, |
181 | void *arg0, void *arg1, void *arg2, void *arg3) |
182 | { |
183 | struct proc *p; |
184 | int result; |
185 | |
186 | result = KAUTH_RESULT_DEFER; |
187 | p = arg0; |
188 | |
189 | if (action != KAUTH_PROCESS_KEVENT_FILTER) |
190 | return result; |
191 | |
192 | if ((kauth_cred_getuid(p->p_cred) != kauth_cred_getuid(cred) || |
193 | ISSET(p->p_flag, PK_SUGID))) |
194 | return result; |
195 | |
196 | result = KAUTH_RESULT_ALLOW; |
197 | |
198 | return result; |
199 | } |
200 | |
201 | /* |
202 | * Initialize the kqueue subsystem. |
203 | */ |
204 | void |
205 | kqueue_init(void) |
206 | { |
207 | |
208 | rw_init(&kqueue_filter_lock); |
209 | mutex_init(&kqueue_misc_lock, MUTEX_DEFAULT, IPL_NONE); |
210 | |
211 | kqueue_listener = kauth_listen_scope(KAUTH_SCOPE_PROCESS, |
212 | kqueue_listener_cb, NULL); |
213 | } |
214 | |
215 | /* |
216 | * Find kfilter entry by name, or NULL if not found. |
217 | */ |
218 | static struct kfilter * |
219 | kfilter_byname_sys(const char *name) |
220 | { |
221 | int i; |
222 | |
223 | KASSERT(rw_lock_held(&kqueue_filter_lock)); |
224 | |
225 | for (i = 0; sys_kfilters[i].name != NULL; i++) { |
226 | if (strcmp(name, sys_kfilters[i].name) == 0) |
227 | return &sys_kfilters[i]; |
228 | } |
229 | return NULL; |
230 | } |
231 | |
232 | static struct kfilter * |
233 | kfilter_byname_user(const char *name) |
234 | { |
235 | int i; |
236 | |
237 | KASSERT(rw_lock_held(&kqueue_filter_lock)); |
238 | |
239 | /* user filter slots have a NULL name if previously deregistered */ |
240 | for (i = 0; i < user_kfilterc ; i++) { |
241 | if (user_kfilters[i].name != NULL && |
242 | strcmp(name, user_kfilters[i].name) == 0) |
243 | return &user_kfilters[i]; |
244 | } |
245 | return NULL; |
246 | } |
247 | |
248 | static struct kfilter * |
249 | kfilter_byname(const char *name) |
250 | { |
251 | struct kfilter *kfilter; |
252 | |
253 | KASSERT(rw_lock_held(&kqueue_filter_lock)); |
254 | |
255 | if ((kfilter = kfilter_byname_sys(name)) != NULL) |
256 | return kfilter; |
257 | |
258 | return kfilter_byname_user(name); |
259 | } |
260 | |
261 | /* |
262 | * Find kfilter entry by filter id, or NULL if not found. |
263 | * Assumes entries are indexed in filter id order, for speed. |
264 | */ |
265 | static struct kfilter * |
266 | kfilter_byfilter(uint32_t filter) |
267 | { |
268 | struct kfilter *kfilter; |
269 | |
270 | KASSERT(rw_lock_held(&kqueue_filter_lock)); |
271 | |
272 | if (filter < EVFILT_SYSCOUNT) /* it's a system filter */ |
273 | kfilter = &sys_kfilters[filter]; |
274 | else if (user_kfilters != NULL && |
275 | filter < EVFILT_SYSCOUNT + user_kfilterc) |
276 | /* it's a user filter */ |
277 | kfilter = &user_kfilters[filter - EVFILT_SYSCOUNT]; |
278 | else |
279 | return (NULL); /* out of range */ |
280 | KASSERT(kfilter->filter == filter); /* sanity check! */ |
281 | return (kfilter); |
282 | } |
283 | |
284 | /* |
285 | * Register a new kfilter. Stores the entry in user_kfilters. |
286 | * Returns 0 if operation succeeded, or an appropriate errno(2) otherwise. |
287 | * If retfilter != NULL, the new filterid is returned in it. |
288 | */ |
289 | int |
290 | kfilter_register(const char *name, const struct filterops *filtops, |
291 | int *retfilter) |
292 | { |
293 | struct kfilter *kfilter; |
294 | size_t len; |
295 | int i; |
296 | |
297 | if (name == NULL || name[0] == '\0' || filtops == NULL) |
298 | return (EINVAL); /* invalid args */ |
299 | |
300 | rw_enter(&kqueue_filter_lock, RW_WRITER); |
301 | if (kfilter_byname(name) != NULL) { |
302 | rw_exit(&kqueue_filter_lock); |
303 | return (EEXIST); /* already exists */ |
304 | } |
305 | if (user_kfilterc > 0xffffffff - EVFILT_SYSCOUNT) { |
306 | rw_exit(&kqueue_filter_lock); |
307 | return (EINVAL); /* too many */ |
308 | } |
309 | |
310 | for (i = 0; i < user_kfilterc; i++) { |
311 | kfilter = &user_kfilters[i]; |
312 | if (kfilter->name == NULL) { |
313 | /* Previously deregistered slot. Reuse. */ |
314 | goto reuse; |
315 | } |
316 | } |
317 | |
318 | /* check if need to grow user_kfilters */ |
319 | if (user_kfilterc + 1 > user_kfiltermaxc) { |
320 | /* Grow in KFILTER_EXTENT chunks. */ |
321 | user_kfiltermaxc += KFILTER_EXTENT; |
322 | len = user_kfiltermaxc * sizeof(*kfilter); |
323 | kfilter = kmem_alloc(len, KM_SLEEP); |
324 | memset((char *)kfilter + user_kfiltersz, 0, len - user_kfiltersz); |
325 | if (user_kfilters != NULL) { |
326 | memcpy(kfilter, user_kfilters, user_kfiltersz); |
327 | kmem_free(user_kfilters, user_kfiltersz); |
328 | } |
329 | user_kfiltersz = len; |
330 | user_kfilters = kfilter; |
331 | } |
332 | /* Adding new slot */ |
333 | kfilter = &user_kfilters[user_kfilterc++]; |
334 | reuse: |
335 | kfilter->namelen = strlen(name) + 1; |
336 | kfilter->name = kmem_alloc(kfilter->namelen, KM_SLEEP); |
337 | memcpy(__UNCONST(kfilter->name), name, kfilter->namelen); |
338 | |
339 | kfilter->filter = (kfilter - user_kfilters) + EVFILT_SYSCOUNT; |
340 | |
341 | kfilter->filtops = kmem_alloc(sizeof(*filtops), KM_SLEEP); |
342 | memcpy(__UNCONST(kfilter->filtops), filtops, sizeof(*filtops)); |
343 | |
344 | if (retfilter != NULL) |
345 | *retfilter = kfilter->filter; |
346 | rw_exit(&kqueue_filter_lock); |
347 | |
348 | return (0); |
349 | } |
350 | |
351 | /* |
352 | * Unregister a kfilter previously registered with kfilter_register. |
353 | * This retains the filter id, but clears the name and frees filtops (filter |
354 | * operations), so that the number isn't reused during a boot. |
355 | * Returns 0 if operation succeeded, or an appropriate errno(2) otherwise. |
356 | */ |
357 | int |
358 | kfilter_unregister(const char *name) |
359 | { |
360 | struct kfilter *kfilter; |
361 | |
362 | if (name == NULL || name[0] == '\0') |
363 | return (EINVAL); /* invalid name */ |
364 | |
365 | rw_enter(&kqueue_filter_lock, RW_WRITER); |
366 | if (kfilter_byname_sys(name) != NULL) { |
367 | rw_exit(&kqueue_filter_lock); |
368 | return (EINVAL); /* can't detach system filters */ |
369 | } |
370 | |
371 | kfilter = kfilter_byname_user(name); |
372 | if (kfilter == NULL) { |
373 | rw_exit(&kqueue_filter_lock); |
374 | return (ENOENT); |
375 | } |
376 | if (kfilter->refcnt != 0) { |
377 | rw_exit(&kqueue_filter_lock); |
378 | return (EBUSY); |
379 | } |
380 | |
381 | /* Cast away const (but we know it's safe. */ |
382 | kmem_free(__UNCONST(kfilter->name), kfilter->namelen); |
383 | kfilter->name = NULL; /* mark as `not implemented' */ |
384 | |
385 | if (kfilter->filtops != NULL) { |
386 | /* Cast away const (but we know it's safe. */ |
387 | kmem_free(__UNCONST(kfilter->filtops), |
388 | sizeof(*kfilter->filtops)); |
389 | kfilter->filtops = NULL; /* mark as `not implemented' */ |
390 | } |
391 | rw_exit(&kqueue_filter_lock); |
392 | |
393 | return (0); |
394 | } |
395 | |
396 | |
397 | /* |
398 | * Filter attach method for EVFILT_READ and EVFILT_WRITE on normal file |
399 | * descriptors. Calls fileops kqfilter method for given file descriptor. |
400 | */ |
401 | static int |
402 | filt_fileattach(struct knote *kn) |
403 | { |
404 | file_t *fp; |
405 | |
406 | fp = kn->kn_obj; |
407 | |
408 | return (*fp->f_ops->fo_kqfilter)(fp, kn); |
409 | } |
410 | |
411 | /* |
412 | * Filter detach method for EVFILT_READ on kqueue descriptor. |
413 | */ |
414 | static void |
415 | filt_kqdetach(struct knote *kn) |
416 | { |
417 | struct kqueue *kq; |
418 | |
419 | kq = ((file_t *)kn->kn_obj)->f_kqueue; |
420 | |
421 | mutex_spin_enter(&kq->kq_lock); |
422 | SLIST_REMOVE(&kq->kq_sel.sel_klist, kn, knote, kn_selnext); |
423 | mutex_spin_exit(&kq->kq_lock); |
424 | } |
425 | |
426 | /* |
427 | * Filter event method for EVFILT_READ on kqueue descriptor. |
428 | */ |
429 | /*ARGSUSED*/ |
430 | static int |
431 | filt_kqueue(struct knote *kn, long hint) |
432 | { |
433 | struct kqueue *kq; |
434 | int rv; |
435 | |
436 | kq = ((file_t *)kn->kn_obj)->f_kqueue; |
437 | |
438 | if (hint != NOTE_SUBMIT) |
439 | mutex_spin_enter(&kq->kq_lock); |
440 | kn->kn_data = kq->kq_count; |
441 | rv = (kn->kn_data > 0); |
442 | if (hint != NOTE_SUBMIT) |
443 | mutex_spin_exit(&kq->kq_lock); |
444 | |
445 | return rv; |
446 | } |
447 | |
448 | /* |
449 | * Filter attach method for EVFILT_PROC. |
450 | */ |
451 | static int |
452 | filt_procattach(struct knote *kn) |
453 | { |
454 | struct proc *p; |
455 | struct lwp *curl; |
456 | |
457 | curl = curlwp; |
458 | |
459 | mutex_enter(proc_lock); |
460 | if (kn->kn_flags & EV_FLAG1) { |
461 | /* |
462 | * NOTE_TRACK attaches to the child process too early |
463 | * for proc_find, so do a raw look up and check the state |
464 | * explicitly. |
465 | */ |
466 | p = proc_find_raw(kn->kn_id); |
467 | if (p != NULL && p->p_stat != SIDL) |
468 | p = NULL; |
469 | } else { |
470 | p = proc_find(kn->kn_id); |
471 | } |
472 | |
473 | if (p == NULL) { |
474 | mutex_exit(proc_lock); |
475 | return ESRCH; |
476 | } |
477 | |
478 | /* |
479 | * Fail if it's not owned by you, or the last exec gave us |
480 | * setuid/setgid privs (unless you're root). |
481 | */ |
482 | mutex_enter(p->p_lock); |
483 | mutex_exit(proc_lock); |
484 | if (kauth_authorize_process(curl->l_cred, KAUTH_PROCESS_KEVENT_FILTER, |
485 | p, NULL, NULL, NULL) != 0) { |
486 | mutex_exit(p->p_lock); |
487 | return EACCES; |
488 | } |
489 | |
490 | kn->kn_obj = p; |
491 | kn->kn_flags |= EV_CLEAR; /* automatically set */ |
492 | |
493 | /* |
494 | * internal flag indicating registration done by kernel |
495 | */ |
496 | if (kn->kn_flags & EV_FLAG1) { |
497 | kn->kn_data = kn->kn_sdata; /* ppid */ |
498 | kn->kn_fflags = NOTE_CHILD; |
499 | kn->kn_flags &= ~EV_FLAG1; |
500 | } |
501 | SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); |
502 | mutex_exit(p->p_lock); |
503 | |
504 | return 0; |
505 | } |
506 | |
507 | /* |
508 | * Filter detach method for EVFILT_PROC. |
509 | * |
510 | * The knote may be attached to a different process, which may exit, |
511 | * leaving nothing for the knote to be attached to. So when the process |
512 | * exits, the knote is marked as DETACHED and also flagged as ONESHOT so |
513 | * it will be deleted when read out. However, as part of the knote deletion, |
514 | * this routine is called, so a check is needed to avoid actually performing |
515 | * a detach, because the original process might not exist any more. |
516 | */ |
517 | static void |
518 | filt_procdetach(struct knote *kn) |
519 | { |
520 | struct proc *p; |
521 | |
522 | if (kn->kn_status & KN_DETACHED) |
523 | return; |
524 | |
525 | p = kn->kn_obj; |
526 | |
527 | mutex_enter(p->p_lock); |
528 | SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); |
529 | mutex_exit(p->p_lock); |
530 | } |
531 | |
532 | /* |
533 | * Filter event method for EVFILT_PROC. |
534 | */ |
535 | static int |
536 | filt_proc(struct knote *kn, long hint) |
537 | { |
538 | u_int event, fflag; |
539 | struct kevent kev; |
540 | struct kqueue *kq; |
541 | int error; |
542 | |
543 | event = (u_int)hint & NOTE_PCTRLMASK; |
544 | kq = kn->kn_kq; |
545 | fflag = 0; |
546 | |
547 | /* If the user is interested in this event, record it. */ |
548 | if (kn->kn_sfflags & event) |
549 | fflag |= event; |
550 | |
551 | if (event == NOTE_EXIT) { |
552 | struct proc *p = kn->kn_obj; |
553 | |
554 | if (p != NULL) |
555 | kn->kn_data = P_WAITSTATUS(p); |
556 | /* |
557 | * Process is gone, so flag the event as finished. |
558 | * |
559 | * Detach the knote from watched process and mark |
560 | * it as such. We can't leave this to kqueue_scan(), |
561 | * since the process might not exist by then. And we |
562 | * have to do this now, since psignal KNOTE() is called |
563 | * also for zombies and we might end up reading freed |
564 | * memory if the kevent would already be picked up |
565 | * and knote g/c'ed. |
566 | */ |
567 | filt_procdetach(kn); |
568 | |
569 | mutex_spin_enter(&kq->kq_lock); |
570 | kn->kn_status |= KN_DETACHED; |
571 | /* Mark as ONESHOT, so that the knote it g/c'ed when read */ |
572 | kn->kn_flags |= (EV_EOF | EV_ONESHOT); |
573 | kn->kn_fflags |= fflag; |
574 | mutex_spin_exit(&kq->kq_lock); |
575 | |
576 | return 1; |
577 | } |
578 | |
579 | mutex_spin_enter(&kq->kq_lock); |
580 | if ((event == NOTE_FORK) && (kn->kn_sfflags & NOTE_TRACK)) { |
581 | /* |
582 | * Process forked, and user wants to track the new process, |
583 | * so attach a new knote to it, and immediately report an |
584 | * event with the parent's pid. Register knote with new |
585 | * process. |
586 | */ |
587 | kev.ident = hint & NOTE_PDATAMASK; /* pid */ |
588 | kev.filter = kn->kn_filter; |
589 | kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; |
590 | kev.fflags = kn->kn_sfflags; |
591 | kev.data = kn->kn_id; /* parent */ |
592 | kev.udata = kn->kn_kevent.udata; /* preserve udata */ |
593 | mutex_spin_exit(&kq->kq_lock); |
594 | error = kqueue_register(kq, &kev); |
595 | mutex_spin_enter(&kq->kq_lock); |
596 | if (error != 0) |
597 | kn->kn_fflags |= NOTE_TRACKERR; |
598 | } |
599 | kn->kn_fflags |= fflag; |
600 | fflag = kn->kn_fflags; |
601 | mutex_spin_exit(&kq->kq_lock); |
602 | |
603 | return fflag != 0; |
604 | } |
605 | |
606 | static void |
607 | filt_timerexpire(void *knx) |
608 | { |
609 | struct knote *kn = knx; |
610 | int tticks; |
611 | |
612 | mutex_enter(&kqueue_misc_lock); |
613 | kn->kn_data++; |
614 | knote_activate(kn); |
615 | if ((kn->kn_flags & EV_ONESHOT) == 0) { |
616 | tticks = mstohz(kn->kn_sdata); |
617 | if (tticks <= 0) |
618 | tticks = 1; |
619 | callout_schedule((callout_t *)kn->kn_hook, tticks); |
620 | } |
621 | mutex_exit(&kqueue_misc_lock); |
622 | } |
623 | |
624 | /* |
625 | * data contains amount of time to sleep, in milliseconds |
626 | */ |
627 | static int |
628 | filt_timerattach(struct knote *kn) |
629 | { |
630 | callout_t *calloutp; |
631 | struct kqueue *kq; |
632 | int tticks; |
633 | |
634 | tticks = mstohz(kn->kn_sdata); |
635 | |
636 | /* if the supplied value is under our resolution, use 1 tick */ |
637 | if (tticks == 0) { |
638 | if (kn->kn_sdata == 0) |
639 | return EINVAL; |
640 | tticks = 1; |
641 | } |
642 | |
643 | if (atomic_inc_uint_nv(&kq_ncallouts) >= kq_calloutmax || |
644 | (calloutp = kmem_alloc(sizeof(*calloutp), KM_NOSLEEP)) == NULL) { |
645 | atomic_dec_uint(&kq_ncallouts); |
646 | return ENOMEM; |
647 | } |
648 | callout_init(calloutp, CALLOUT_MPSAFE); |
649 | |
650 | kq = kn->kn_kq; |
651 | mutex_spin_enter(&kq->kq_lock); |
652 | kn->kn_flags |= EV_CLEAR; /* automatically set */ |
653 | kn->kn_hook = calloutp; |
654 | mutex_spin_exit(&kq->kq_lock); |
655 | |
656 | callout_reset(calloutp, tticks, filt_timerexpire, kn); |
657 | |
658 | return (0); |
659 | } |
660 | |
661 | static void |
662 | filt_timerdetach(struct knote *kn) |
663 | { |
664 | callout_t *calloutp; |
665 | |
666 | calloutp = (callout_t *)kn->kn_hook; |
667 | callout_halt(calloutp, NULL); |
668 | callout_destroy(calloutp); |
669 | kmem_free(calloutp, sizeof(*calloutp)); |
670 | atomic_dec_uint(&kq_ncallouts); |
671 | } |
672 | |
673 | static int |
674 | filt_timer(struct knote *kn, long hint) |
675 | { |
676 | int rv; |
677 | |
678 | mutex_enter(&kqueue_misc_lock); |
679 | rv = (kn->kn_data != 0); |
680 | mutex_exit(&kqueue_misc_lock); |
681 | |
682 | return rv; |
683 | } |
684 | |
685 | /* |
686 | * filt_seltrue: |
687 | * |
688 | * This filter "event" routine simulates seltrue(). |
689 | */ |
690 | int |
691 | filt_seltrue(struct knote *kn, long hint) |
692 | { |
693 | |
694 | /* |
695 | * We don't know how much data can be read/written, |
696 | * but we know that it *can* be. This is about as |
697 | * good as select/poll does as well. |
698 | */ |
699 | kn->kn_data = 0; |
700 | return (1); |
701 | } |
702 | |
703 | /* |
704 | * This provides full kqfilter entry for device switch tables, which |
705 | * has same effect as filter using filt_seltrue() as filter method. |
706 | */ |
707 | static void |
708 | filt_seltruedetach(struct knote *kn) |
709 | { |
710 | /* Nothing to do */ |
711 | } |
712 | |
713 | const struct filterops seltrue_filtops = |
714 | { 1, NULL, filt_seltruedetach, filt_seltrue }; |
715 | |
716 | int |
717 | seltrue_kqfilter(dev_t dev, struct knote *kn) |
718 | { |
719 | switch (kn->kn_filter) { |
720 | case EVFILT_READ: |
721 | case EVFILT_WRITE: |
722 | kn->kn_fop = &seltrue_filtops; |
723 | break; |
724 | default: |
725 | return (EINVAL); |
726 | } |
727 | |
728 | /* Nothing more to do */ |
729 | return (0); |
730 | } |
731 | |
732 | /* |
733 | * kqueue(2) system call. |
734 | */ |
735 | static int |
736 | kqueue1(struct lwp *l, int flags, register_t *retval) |
737 | { |
738 | struct kqueue *kq; |
739 | file_t *fp; |
740 | int fd, error; |
741 | |
742 | if ((error = fd_allocfile(&fp, &fd)) != 0) |
743 | return error; |
744 | fp->f_flag = FREAD | FWRITE | (flags & (FNONBLOCK|FNOSIGPIPE)); |
745 | fp->f_type = DTYPE_KQUEUE; |
746 | fp->f_ops = &kqueueops; |
747 | kq = kmem_zalloc(sizeof(*kq), KM_SLEEP); |
748 | mutex_init(&kq->kq_lock, MUTEX_DEFAULT, IPL_SCHED); |
749 | cv_init(&kq->kq_cv, "kqueue" ); |
750 | selinit(&kq->kq_sel); |
751 | TAILQ_INIT(&kq->kq_head); |
752 | fp->f_kqueue = kq; |
753 | *retval = fd; |
754 | kq->kq_fdp = curlwp->l_fd; |
755 | fd_set_exclose(l, fd, (flags & O_CLOEXEC) != 0); |
756 | fd_affix(curproc, fp, fd); |
757 | return error; |
758 | } |
759 | |
760 | /* |
761 | * kqueue(2) system call. |
762 | */ |
763 | int |
764 | sys_kqueue(struct lwp *l, const void *v, register_t *retval) |
765 | { |
766 | return kqueue1(l, 0, retval); |
767 | } |
768 | |
769 | int |
770 | sys_kqueue1(struct lwp *l, const struct sys_kqueue1_args *uap, |
771 | register_t *retval) |
772 | { |
773 | /* { |
774 | syscallarg(int) flags; |
775 | } */ |
776 | return kqueue1(l, SCARG(uap, flags), retval); |
777 | } |
778 | |
779 | /* |
780 | * kevent(2) system call. |
781 | */ |
782 | int |
783 | kevent_fetch_changes(void *ctx, const struct kevent *changelist, |
784 | struct kevent *changes, size_t index, int n) |
785 | { |
786 | |
787 | return copyin(changelist + index, changes, n * sizeof(*changes)); |
788 | } |
789 | |
790 | int |
791 | kevent_put_events(void *ctx, struct kevent *events, |
792 | struct kevent *eventlist, size_t index, int n) |
793 | { |
794 | |
795 | return copyout(events, eventlist + index, n * sizeof(*events)); |
796 | } |
797 | |
798 | static const struct kevent_ops kevent_native_ops = { |
799 | .keo_private = NULL, |
800 | .keo_fetch_timeout = copyin, |
801 | .keo_fetch_changes = kevent_fetch_changes, |
802 | .keo_put_events = kevent_put_events, |
803 | }; |
804 | |
805 | int |
806 | sys___kevent50(struct lwp *l, const struct sys___kevent50_args *uap, |
807 | register_t *retval) |
808 | { |
809 | /* { |
810 | syscallarg(int) fd; |
811 | syscallarg(const struct kevent *) changelist; |
812 | syscallarg(size_t) nchanges; |
813 | syscallarg(struct kevent *) eventlist; |
814 | syscallarg(size_t) nevents; |
815 | syscallarg(const struct timespec *) timeout; |
816 | } */ |
817 | |
818 | return kevent1(retval, SCARG(uap, fd), SCARG(uap, changelist), |
819 | SCARG(uap, nchanges), SCARG(uap, eventlist), SCARG(uap, nevents), |
820 | SCARG(uap, timeout), &kevent_native_ops); |
821 | } |
822 | |
823 | int |
824 | kevent1(register_t *retval, int fd, |
825 | const struct kevent *changelist, size_t nchanges, |
826 | struct kevent *eventlist, size_t nevents, |
827 | const struct timespec *timeout, |
828 | const struct kevent_ops *keops) |
829 | { |
830 | struct kevent *kevp; |
831 | struct kqueue *kq; |
832 | struct timespec ts; |
833 | size_t i, n, ichange; |
834 | int nerrors, error; |
835 | struct kevent kevbuf[KQ_NEVENTS]; /* approx 300 bytes on 64-bit */ |
836 | file_t *fp; |
837 | |
838 | /* check that we're dealing with a kq */ |
839 | fp = fd_getfile(fd); |
840 | if (fp == NULL) |
841 | return (EBADF); |
842 | |
843 | if (fp->f_type != DTYPE_KQUEUE) { |
844 | fd_putfile(fd); |
845 | return (EBADF); |
846 | } |
847 | |
848 | if (timeout != NULL) { |
849 | error = (*keops->keo_fetch_timeout)(timeout, &ts, sizeof(ts)); |
850 | if (error) |
851 | goto done; |
852 | timeout = &ts; |
853 | } |
854 | |
855 | kq = fp->f_kqueue; |
856 | nerrors = 0; |
857 | ichange = 0; |
858 | |
859 | /* traverse list of events to register */ |
860 | while (nchanges > 0) { |
861 | n = MIN(nchanges, __arraycount(kevbuf)); |
862 | error = (*keops->keo_fetch_changes)(keops->keo_private, |
863 | changelist, kevbuf, ichange, n); |
864 | if (error) |
865 | goto done; |
866 | for (i = 0; i < n; i++) { |
867 | kevp = &kevbuf[i]; |
868 | kevp->flags &= ~EV_SYSFLAGS; |
869 | /* register each knote */ |
870 | error = kqueue_register(kq, kevp); |
871 | if (error || (kevp->flags & EV_RECEIPT)) { |
872 | if (nevents != 0) { |
873 | kevp->flags = EV_ERROR; |
874 | kevp->data = error; |
875 | error = (*keops->keo_put_events) |
876 | (keops->keo_private, kevp, |
877 | eventlist, nerrors, 1); |
878 | if (error) |
879 | goto done; |
880 | nevents--; |
881 | nerrors++; |
882 | } else { |
883 | goto done; |
884 | } |
885 | } |
886 | } |
887 | nchanges -= n; /* update the results */ |
888 | ichange += n; |
889 | } |
890 | if (nerrors) { |
891 | *retval = nerrors; |
892 | error = 0; |
893 | goto done; |
894 | } |
895 | |
896 | /* actually scan through the events */ |
897 | error = kqueue_scan(fp, nevents, eventlist, timeout, retval, keops, |
898 | kevbuf, __arraycount(kevbuf)); |
899 | done: |
900 | fd_putfile(fd); |
901 | return (error); |
902 | } |
903 | |
904 | /* |
905 | * Register a given kevent kev onto the kqueue |
906 | */ |
907 | static int |
908 | kqueue_register(struct kqueue *kq, struct kevent *kev) |
909 | { |
910 | struct kfilter *kfilter; |
911 | filedesc_t *fdp; |
912 | file_t *fp; |
913 | fdfile_t *ff; |
914 | struct knote *kn, *newkn; |
915 | struct klist *list; |
916 | int error, fd, rv; |
917 | |
918 | fdp = kq->kq_fdp; |
919 | fp = NULL; |
920 | kn = NULL; |
921 | error = 0; |
922 | fd = 0; |
923 | |
924 | newkn = kmem_zalloc(sizeof(*newkn), KM_SLEEP); |
925 | |
926 | rw_enter(&kqueue_filter_lock, RW_READER); |
927 | kfilter = kfilter_byfilter(kev->filter); |
928 | if (kfilter == NULL || kfilter->filtops == NULL) { |
929 | /* filter not found nor implemented */ |
930 | rw_exit(&kqueue_filter_lock); |
931 | kmem_free(newkn, sizeof(*newkn)); |
932 | return (EINVAL); |
933 | } |
934 | |
935 | /* search if knote already exists */ |
936 | if (kfilter->filtops->f_isfd) { |
937 | /* monitoring a file descriptor */ |
938 | /* validate descriptor */ |
939 | if (kev->ident > INT_MAX |
940 | || (fp = fd_getfile(fd = kev->ident)) == NULL) { |
941 | rw_exit(&kqueue_filter_lock); |
942 | kmem_free(newkn, sizeof(*newkn)); |
943 | return EBADF; |
944 | } |
945 | mutex_enter(&fdp->fd_lock); |
946 | ff = fdp->fd_dt->dt_ff[fd]; |
947 | if (fd <= fdp->fd_lastkqfile) { |
948 | SLIST_FOREACH(kn, &ff->ff_knlist, kn_link) { |
949 | if (kq == kn->kn_kq && |
950 | kev->filter == kn->kn_filter) |
951 | break; |
952 | } |
953 | } |
954 | } else { |
955 | /* |
956 | * not monitoring a file descriptor, so |
957 | * lookup knotes in internal hash table |
958 | */ |
959 | mutex_enter(&fdp->fd_lock); |
960 | if (fdp->fd_knhashmask != 0) { |
961 | list = &fdp->fd_knhash[ |
962 | KN_HASH((u_long)kev->ident, fdp->fd_knhashmask)]; |
963 | SLIST_FOREACH(kn, list, kn_link) { |
964 | if (kev->ident == kn->kn_id && |
965 | kq == kn->kn_kq && |
966 | kev->filter == kn->kn_filter) |
967 | break; |
968 | } |
969 | } |
970 | } |
971 | |
972 | /* |
973 | * kn now contains the matching knote, or NULL if no match |
974 | */ |
975 | if (kev->flags & EV_ADD) { |
976 | if (kn == NULL) { |
977 | /* create new knote */ |
978 | kn = newkn; |
979 | newkn = NULL; |
980 | kn->kn_obj = fp; |
981 | kn->kn_id = kev->ident; |
982 | kn->kn_kq = kq; |
983 | kn->kn_fop = kfilter->filtops; |
984 | kn->kn_kfilter = kfilter; |
985 | kn->kn_sfflags = kev->fflags; |
986 | kn->kn_sdata = kev->data; |
987 | kev->fflags = 0; |
988 | kev->data = 0; |
989 | kn->kn_kevent = *kev; |
990 | |
991 | KASSERT(kn->kn_fop != NULL); |
992 | /* |
993 | * apply reference count to knote structure, and |
994 | * do not release it at the end of this routine. |
995 | */ |
996 | fp = NULL; |
997 | |
998 | if (!kn->kn_fop->f_isfd) { |
999 | /* |
1000 | * If knote is not on an fd, store on |
1001 | * internal hash table. |
1002 | */ |
1003 | if (fdp->fd_knhashmask == 0) { |
1004 | /* XXXAD can block with fd_lock held */ |
1005 | fdp->fd_knhash = hashinit(KN_HASHSIZE, |
1006 | HASH_LIST, true, |
1007 | &fdp->fd_knhashmask); |
1008 | } |
1009 | list = &fdp->fd_knhash[KN_HASH(kn->kn_id, |
1010 | fdp->fd_knhashmask)]; |
1011 | } else { |
1012 | /* Otherwise, knote is on an fd. */ |
1013 | list = (struct klist *) |
1014 | &fdp->fd_dt->dt_ff[kn->kn_id]->ff_knlist; |
1015 | if ((int)kn->kn_id > fdp->fd_lastkqfile) |
1016 | fdp->fd_lastkqfile = kn->kn_id; |
1017 | } |
1018 | SLIST_INSERT_HEAD(list, kn, kn_link); |
1019 | |
1020 | KERNEL_LOCK(1, NULL); /* XXXSMP */ |
1021 | error = (*kfilter->filtops->f_attach)(kn); |
1022 | KERNEL_UNLOCK_ONE(NULL); /* XXXSMP */ |
1023 | if (error != 0) { |
1024 | #ifdef DIAGNOSTIC |
1025 | printf("%s: event not supported for file type" |
1026 | " %d\n" , __func__, fp ? fp->f_type : -1); |
1027 | #endif |
1028 | /* knote_detach() drops fdp->fd_lock */ |
1029 | knote_detach(kn, fdp, false); |
1030 | goto done; |
1031 | } |
1032 | atomic_inc_uint(&kfilter->refcnt); |
1033 | } else { |
1034 | /* |
1035 | * The user may change some filter values after the |
1036 | * initial EV_ADD, but doing so will not reset any |
1037 | * filter which have already been triggered. |
1038 | */ |
1039 | kn->kn_sfflags = kev->fflags; |
1040 | kn->kn_sdata = kev->data; |
1041 | kn->kn_kevent.udata = kev->udata; |
1042 | } |
1043 | /* |
1044 | * We can get here if we are trying to attach |
1045 | * an event to a file descriptor that does not |
1046 | * support events, and the attach routine is |
1047 | * broken and does not return an error. |
1048 | */ |
1049 | KASSERT(kn->kn_fop != NULL); |
1050 | KASSERT(kn->kn_fop->f_event != NULL); |
1051 | KERNEL_LOCK(1, NULL); /* XXXSMP */ |
1052 | rv = (*kn->kn_fop->f_event)(kn, 0); |
1053 | KERNEL_UNLOCK_ONE(NULL); /* XXXSMP */ |
1054 | if (rv) |
1055 | knote_activate(kn); |
1056 | } else { |
1057 | if (kn == NULL) { |
1058 | error = ENOENT; |
1059 | mutex_exit(&fdp->fd_lock); |
1060 | goto done; |
1061 | } |
1062 | if (kev->flags & EV_DELETE) { |
1063 | /* knote_detach() drops fdp->fd_lock */ |
1064 | knote_detach(kn, fdp, true); |
1065 | goto done; |
1066 | } |
1067 | } |
1068 | |
1069 | /* disable knote */ |
1070 | if ((kev->flags & EV_DISABLE)) { |
1071 | mutex_spin_enter(&kq->kq_lock); |
1072 | if ((kn->kn_status & KN_DISABLED) == 0) |
1073 | kn->kn_status |= KN_DISABLED; |
1074 | mutex_spin_exit(&kq->kq_lock); |
1075 | } |
1076 | |
1077 | /* enable knote */ |
1078 | if ((kev->flags & EV_ENABLE)) { |
1079 | knote_enqueue(kn); |
1080 | } |
1081 | mutex_exit(&fdp->fd_lock); |
1082 | done: |
1083 | rw_exit(&kqueue_filter_lock); |
1084 | if (newkn != NULL) |
1085 | kmem_free(newkn, sizeof(*newkn)); |
1086 | if (fp != NULL) |
1087 | fd_putfile(fd); |
1088 | return (error); |
1089 | } |
1090 | |
1091 | #if defined(DEBUG) |
1092 | static void |
1093 | kq_check(struct kqueue *kq) |
1094 | { |
1095 | const struct knote *kn; |
1096 | int count; |
1097 | int nmarker; |
1098 | |
1099 | KASSERT(mutex_owned(&kq->kq_lock)); |
1100 | KASSERT(kq->kq_count >= 0); |
1101 | |
1102 | count = 0; |
1103 | nmarker = 0; |
1104 | TAILQ_FOREACH(kn, &kq->kq_head, kn_tqe) { |
1105 | if ((kn->kn_status & (KN_MARKER | KN_QUEUED)) == 0) { |
1106 | panic("%s: kq=%p kn=%p inconsist 1" , __func__, kq, kn); |
1107 | } |
1108 | if ((kn->kn_status & KN_MARKER) == 0) { |
1109 | if (kn->kn_kq != kq) { |
1110 | panic("%s: kq=%p kn=%p inconsist 2" , |
1111 | __func__, kq, kn); |
1112 | } |
1113 | if ((kn->kn_status & KN_ACTIVE) == 0) { |
1114 | panic("%s: kq=%p kn=%p: not active" , |
1115 | __func__, kq, kn); |
1116 | } |
1117 | count++; |
1118 | if (count > kq->kq_count) { |
1119 | goto bad; |
1120 | } |
1121 | } else { |
1122 | nmarker++; |
1123 | #if 0 |
1124 | if (nmarker > 10000) { |
1125 | panic("%s: kq=%p too many markers: %d != %d, " |
1126 | "nmarker=%d" , |
1127 | __func__, kq, kq->kq_count, count, nmarker); |
1128 | } |
1129 | #endif |
1130 | } |
1131 | } |
1132 | if (kq->kq_count != count) { |
1133 | bad: |
1134 | panic("%s: kq=%p inconsist 3: %d != %d, nmarker=%d" , |
1135 | __func__, kq, kq->kq_count, count, nmarker); |
1136 | } |
1137 | } |
1138 | #else /* defined(DEBUG) */ |
1139 | #define kq_check(a) /* nothing */ |
1140 | #endif /* defined(DEBUG) */ |
1141 | |
1142 | /* |
1143 | * Scan through the list of events on fp (for a maximum of maxevents), |
1144 | * returning the results in to ulistp. Timeout is determined by tsp; if |
1145 | * NULL, wait indefinitely, if 0 valued, perform a poll, otherwise wait |
1146 | * as appropriate. |
1147 | */ |
1148 | static int |
1149 | kqueue_scan(file_t *fp, size_t maxevents, struct kevent *ulistp, |
1150 | const struct timespec *tsp, register_t *retval, |
1151 | const struct kevent_ops *keops, struct kevent *kevbuf, |
1152 | size_t kevcnt) |
1153 | { |
1154 | struct kqueue *kq; |
1155 | struct kevent *kevp; |
1156 | struct timespec ats, sleepts; |
1157 | struct knote *kn, *marker, morker; |
1158 | size_t count, nkev, nevents; |
1159 | int timeout, error, rv; |
1160 | filedesc_t *fdp; |
1161 | |
1162 | fdp = curlwp->l_fd; |
1163 | kq = fp->f_kqueue; |
1164 | count = maxevents; |
1165 | nkev = nevents = error = 0; |
1166 | if (count == 0) { |
1167 | *retval = 0; |
1168 | return 0; |
1169 | } |
1170 | |
1171 | if (tsp) { /* timeout supplied */ |
1172 | ats = *tsp; |
1173 | if (inittimeleft(&ats, &sleepts) == -1) { |
1174 | *retval = maxevents; |
1175 | return EINVAL; |
1176 | } |
1177 | timeout = tstohz(&ats); |
1178 | if (timeout <= 0) |
1179 | timeout = -1; /* do poll */ |
1180 | } else { |
1181 | /* no timeout, wait forever */ |
1182 | timeout = 0; |
1183 | } |
1184 | |
1185 | memset(&morker, 0, sizeof(morker)); |
1186 | marker = &morker; |
1187 | marker->kn_status = KN_MARKER; |
1188 | mutex_spin_enter(&kq->kq_lock); |
1189 | retry: |
1190 | kevp = kevbuf; |
1191 | if (kq->kq_count == 0) { |
1192 | if (timeout >= 0) { |
1193 | error = cv_timedwait_sig(&kq->kq_cv, |
1194 | &kq->kq_lock, timeout); |
1195 | if (error == 0) { |
1196 | if (tsp == NULL || (timeout = |
1197 | gettimeleft(&ats, &sleepts)) > 0) |
1198 | goto retry; |
1199 | } else { |
1200 | /* don't restart after signals... */ |
1201 | if (error == ERESTART) |
1202 | error = EINTR; |
1203 | if (error == EWOULDBLOCK) |
1204 | error = 0; |
1205 | } |
1206 | } |
1207 | } else { |
1208 | /* mark end of knote list */ |
1209 | TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); |
1210 | |
1211 | while (count != 0) { |
1212 | kn = TAILQ_FIRST(&kq->kq_head); /* get next knote */ |
1213 | while ((kn->kn_status & KN_MARKER) != 0) { |
1214 | if (kn == marker) { |
1215 | /* it's our marker, stop */ |
1216 | TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); |
1217 | if (count < maxevents || (tsp != NULL && |
1218 | (timeout = gettimeleft(&ats, |
1219 | &sleepts)) <= 0)) |
1220 | goto done; |
1221 | goto retry; |
1222 | } |
1223 | /* someone else's marker. */ |
1224 | kn = TAILQ_NEXT(kn, kn_tqe); |
1225 | } |
1226 | kq_check(kq); |
1227 | kq->kq_count--; |
1228 | TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); |
1229 | kn->kn_status &= ~KN_QUEUED; |
1230 | kn->kn_status |= KN_BUSY; |
1231 | kq_check(kq); |
1232 | if (kn->kn_status & KN_DISABLED) { |
1233 | kn->kn_status &= ~KN_BUSY; |
1234 | /* don't want disabled events */ |
1235 | continue; |
1236 | } |
1237 | if ((kn->kn_flags & EV_ONESHOT) == 0) { |
1238 | mutex_spin_exit(&kq->kq_lock); |
1239 | KASSERT(kn->kn_fop != NULL); |
1240 | KASSERT(kn->kn_fop->f_event != NULL); |
1241 | KERNEL_LOCK(1, NULL); /* XXXSMP */ |
1242 | rv = (*kn->kn_fop->f_event)(kn, 0); |
1243 | KERNEL_UNLOCK_ONE(NULL); /* XXXSMP */ |
1244 | mutex_spin_enter(&kq->kq_lock); |
1245 | /* Re-poll if note was re-enqueued. */ |
1246 | if ((kn->kn_status & KN_QUEUED) != 0) { |
1247 | kn->kn_status &= ~KN_BUSY; |
1248 | continue; |
1249 | } |
1250 | if (rv == 0) { |
1251 | /* |
1252 | * non-ONESHOT event that hasn't |
1253 | * triggered again, so de-queue. |
1254 | */ |
1255 | kn->kn_status &= ~(KN_ACTIVE|KN_BUSY); |
1256 | continue; |
1257 | } |
1258 | } |
1259 | /* XXXAD should be got from f_event if !oneshot. */ |
1260 | *kevp++ = kn->kn_kevent; |
1261 | nkev++; |
1262 | if (kn->kn_flags & EV_ONESHOT) { |
1263 | /* delete ONESHOT events after retrieval */ |
1264 | mutex_spin_exit(&kq->kq_lock); |
1265 | mutex_enter(&fdp->fd_lock); |
1266 | kn->kn_status &= ~KN_BUSY; |
1267 | knote_detach(kn, fdp, true); |
1268 | mutex_spin_enter(&kq->kq_lock); |
1269 | } else if (kn->kn_flags & EV_CLEAR) { |
1270 | /* clear state after retrieval */ |
1271 | kn->kn_data = 0; |
1272 | kn->kn_fflags = 0; |
1273 | kn->kn_status &= ~(KN_QUEUED|KN_ACTIVE|KN_BUSY); |
1274 | } else if (kn->kn_flags & EV_DISPATCH) { |
1275 | kn->kn_status |= KN_DISABLED; |
1276 | kn->kn_status &= ~(KN_QUEUED|KN_ACTIVE|KN_BUSY); |
1277 | } else { |
1278 | /* add event back on list */ |
1279 | kq_check(kq); |
1280 | kn->kn_status |= KN_QUEUED; |
1281 | kn->kn_status &= ~KN_BUSY; |
1282 | TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); |
1283 | kq->kq_count++; |
1284 | kq_check(kq); |
1285 | } |
1286 | if (nkev == kevcnt) { |
1287 | /* do copyouts in kevcnt chunks */ |
1288 | mutex_spin_exit(&kq->kq_lock); |
1289 | error = (*keops->keo_put_events) |
1290 | (keops->keo_private, |
1291 | kevbuf, ulistp, nevents, nkev); |
1292 | mutex_spin_enter(&kq->kq_lock); |
1293 | nevents += nkev; |
1294 | nkev = 0; |
1295 | kevp = kevbuf; |
1296 | } |
1297 | count--; |
1298 | if (error != 0 || count == 0) { |
1299 | /* remove marker */ |
1300 | TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); |
1301 | break; |
1302 | } |
1303 | } |
1304 | } |
1305 | done: |
1306 | mutex_spin_exit(&kq->kq_lock); |
1307 | if (nkev != 0) { |
1308 | /* copyout remaining events */ |
1309 | error = (*keops->keo_put_events)(keops->keo_private, |
1310 | kevbuf, ulistp, nevents, nkev); |
1311 | } |
1312 | *retval = maxevents - count; |
1313 | |
1314 | return error; |
1315 | } |
1316 | |
1317 | /* |
1318 | * fileops ioctl method for a kqueue descriptor. |
1319 | * |
1320 | * Two ioctls are currently supported. They both use struct kfilter_mapping: |
1321 | * KFILTER_BYNAME find name for filter, and return result in |
1322 | * name, which is of size len. |
1323 | * KFILTER_BYFILTER find filter for name. len is ignored. |
1324 | */ |
1325 | /*ARGSUSED*/ |
1326 | static int |
1327 | kqueue_ioctl(file_t *fp, u_long com, void *data) |
1328 | { |
1329 | struct kfilter_mapping *km; |
1330 | const struct kfilter *kfilter; |
1331 | char *name; |
1332 | int error; |
1333 | |
1334 | km = data; |
1335 | error = 0; |
1336 | name = kmem_alloc(KFILTER_MAXNAME, KM_SLEEP); |
1337 | |
1338 | switch (com) { |
1339 | case KFILTER_BYFILTER: /* convert filter -> name */ |
1340 | rw_enter(&kqueue_filter_lock, RW_READER); |
1341 | kfilter = kfilter_byfilter(km->filter); |
1342 | if (kfilter != NULL) { |
1343 | strlcpy(name, kfilter->name, KFILTER_MAXNAME); |
1344 | rw_exit(&kqueue_filter_lock); |
1345 | error = copyoutstr(name, km->name, km->len, NULL); |
1346 | } else { |
1347 | rw_exit(&kqueue_filter_lock); |
1348 | error = ENOENT; |
1349 | } |
1350 | break; |
1351 | |
1352 | case KFILTER_BYNAME: /* convert name -> filter */ |
1353 | error = copyinstr(km->name, name, KFILTER_MAXNAME, NULL); |
1354 | if (error) { |
1355 | break; |
1356 | } |
1357 | rw_enter(&kqueue_filter_lock, RW_READER); |
1358 | kfilter = kfilter_byname(name); |
1359 | if (kfilter != NULL) |
1360 | km->filter = kfilter->filter; |
1361 | else |
1362 | error = ENOENT; |
1363 | rw_exit(&kqueue_filter_lock); |
1364 | break; |
1365 | |
1366 | default: |
1367 | error = ENOTTY; |
1368 | break; |
1369 | |
1370 | } |
1371 | kmem_free(name, KFILTER_MAXNAME); |
1372 | return (error); |
1373 | } |
1374 | |
1375 | /* |
1376 | * fileops fcntl method for a kqueue descriptor. |
1377 | */ |
1378 | static int |
1379 | kqueue_fcntl(file_t *fp, u_int com, void *data) |
1380 | { |
1381 | |
1382 | return (ENOTTY); |
1383 | } |
1384 | |
1385 | /* |
1386 | * fileops poll method for a kqueue descriptor. |
1387 | * Determine if kqueue has events pending. |
1388 | */ |
1389 | static int |
1390 | kqueue_poll(file_t *fp, int events) |
1391 | { |
1392 | struct kqueue *kq; |
1393 | int revents; |
1394 | |
1395 | kq = fp->f_kqueue; |
1396 | |
1397 | revents = 0; |
1398 | if (events & (POLLIN | POLLRDNORM)) { |
1399 | mutex_spin_enter(&kq->kq_lock); |
1400 | if (kq->kq_count != 0) { |
1401 | revents |= events & (POLLIN | POLLRDNORM); |
1402 | } else { |
1403 | selrecord(curlwp, &kq->kq_sel); |
1404 | } |
1405 | kq_check(kq); |
1406 | mutex_spin_exit(&kq->kq_lock); |
1407 | } |
1408 | |
1409 | return revents; |
1410 | } |
1411 | |
1412 | /* |
1413 | * fileops stat method for a kqueue descriptor. |
1414 | * Returns dummy info, with st_size being number of events pending. |
1415 | */ |
1416 | static int |
1417 | kqueue_stat(file_t *fp, struct stat *st) |
1418 | { |
1419 | struct kqueue *kq; |
1420 | |
1421 | kq = fp->f_kqueue; |
1422 | |
1423 | memset(st, 0, sizeof(*st)); |
1424 | st->st_size = kq->kq_count; |
1425 | st->st_blksize = sizeof(struct kevent); |
1426 | st->st_mode = S_IFIFO; |
1427 | |
1428 | return 0; |
1429 | } |
1430 | |
1431 | static void |
1432 | kqueue_doclose(struct kqueue *kq, struct klist *list, int fd) |
1433 | { |
1434 | struct knote *kn; |
1435 | filedesc_t *fdp; |
1436 | |
1437 | fdp = kq->kq_fdp; |
1438 | |
1439 | KASSERT(mutex_owned(&fdp->fd_lock)); |
1440 | |
1441 | for (kn = SLIST_FIRST(list); kn != NULL;) { |
1442 | if (kq != kn->kn_kq) { |
1443 | kn = SLIST_NEXT(kn, kn_link); |
1444 | continue; |
1445 | } |
1446 | knote_detach(kn, fdp, true); |
1447 | mutex_enter(&fdp->fd_lock); |
1448 | kn = SLIST_FIRST(list); |
1449 | } |
1450 | } |
1451 | |
1452 | |
1453 | /* |
1454 | * fileops close method for a kqueue descriptor. |
1455 | */ |
1456 | static int |
1457 | kqueue_close(file_t *fp) |
1458 | { |
1459 | struct kqueue *kq; |
1460 | filedesc_t *fdp; |
1461 | fdfile_t *ff; |
1462 | int i; |
1463 | |
1464 | kq = fp->f_kqueue; |
1465 | fp->f_kqueue = NULL; |
1466 | fp->f_type = 0; |
1467 | fdp = curlwp->l_fd; |
1468 | |
1469 | mutex_enter(&fdp->fd_lock); |
1470 | for (i = 0; i <= fdp->fd_lastkqfile; i++) { |
1471 | if ((ff = fdp->fd_dt->dt_ff[i]) == NULL) |
1472 | continue; |
1473 | kqueue_doclose(kq, (struct klist *)&ff->ff_knlist, i); |
1474 | } |
1475 | if (fdp->fd_knhashmask != 0) { |
1476 | for (i = 0; i < fdp->fd_knhashmask + 1; i++) { |
1477 | kqueue_doclose(kq, &fdp->fd_knhash[i], -1); |
1478 | } |
1479 | } |
1480 | mutex_exit(&fdp->fd_lock); |
1481 | |
1482 | KASSERT(kq->kq_count == 0); |
1483 | mutex_destroy(&kq->kq_lock); |
1484 | cv_destroy(&kq->kq_cv); |
1485 | seldestroy(&kq->kq_sel); |
1486 | kmem_free(kq, sizeof(*kq)); |
1487 | |
1488 | return (0); |
1489 | } |
1490 | |
1491 | /* |
1492 | * struct fileops kqfilter method for a kqueue descriptor. |
1493 | * Event triggered when monitored kqueue changes. |
1494 | */ |
1495 | static int |
1496 | kqueue_kqfilter(file_t *fp, struct knote *kn) |
1497 | { |
1498 | struct kqueue *kq; |
1499 | |
1500 | kq = ((file_t *)kn->kn_obj)->f_kqueue; |
1501 | |
1502 | KASSERT(fp == kn->kn_obj); |
1503 | |
1504 | if (kn->kn_filter != EVFILT_READ) |
1505 | return 1; |
1506 | |
1507 | kn->kn_fop = &kqread_filtops; |
1508 | mutex_enter(&kq->kq_lock); |
1509 | SLIST_INSERT_HEAD(&kq->kq_sel.sel_klist, kn, kn_selnext); |
1510 | mutex_exit(&kq->kq_lock); |
1511 | |
1512 | return 0; |
1513 | } |
1514 | |
1515 | |
1516 | /* |
1517 | * Walk down a list of knotes, activating them if their event has |
1518 | * triggered. The caller's object lock (e.g. device driver lock) |
1519 | * must be held. |
1520 | */ |
1521 | void |
1522 | knote(struct klist *list, long hint) |
1523 | { |
1524 | struct knote *kn, *tmpkn; |
1525 | |
1526 | SLIST_FOREACH_SAFE(kn, list, kn_selnext, tmpkn) { |
1527 | KASSERT(kn->kn_fop != NULL); |
1528 | KASSERT(kn->kn_fop->f_event != NULL); |
1529 | if ((*kn->kn_fop->f_event)(kn, hint)) |
1530 | knote_activate(kn); |
1531 | } |
1532 | } |
1533 | |
1534 | /* |
1535 | * Remove all knotes referencing a specified fd |
1536 | */ |
1537 | void |
1538 | knote_fdclose(int fd) |
1539 | { |
1540 | struct klist *list; |
1541 | struct knote *kn; |
1542 | filedesc_t *fdp; |
1543 | |
1544 | fdp = curlwp->l_fd; |
1545 | list = (struct klist *)&fdp->fd_dt->dt_ff[fd]->ff_knlist; |
1546 | mutex_enter(&fdp->fd_lock); |
1547 | while ((kn = SLIST_FIRST(list)) != NULL) { |
1548 | knote_detach(kn, fdp, true); |
1549 | mutex_enter(&fdp->fd_lock); |
1550 | } |
1551 | mutex_exit(&fdp->fd_lock); |
1552 | } |
1553 | |
1554 | /* |
1555 | * Drop knote. Called with fdp->fd_lock held, and will drop before |
1556 | * returning. |
1557 | */ |
1558 | static void |
1559 | knote_detach(struct knote *kn, filedesc_t *fdp, bool dofop) |
1560 | { |
1561 | struct klist *list; |
1562 | struct kqueue *kq; |
1563 | |
1564 | kq = kn->kn_kq; |
1565 | |
1566 | KASSERT((kn->kn_status & KN_MARKER) == 0); |
1567 | KASSERT(mutex_owned(&fdp->fd_lock)); |
1568 | |
1569 | KASSERT(kn->kn_fop != NULL); |
1570 | /* Remove from monitored object. */ |
1571 | if (dofop) { |
1572 | KASSERT(kn->kn_fop->f_detach != NULL); |
1573 | KERNEL_LOCK(1, NULL); /* XXXSMP */ |
1574 | (*kn->kn_fop->f_detach)(kn); |
1575 | KERNEL_UNLOCK_ONE(NULL); /* XXXSMP */ |
1576 | } |
1577 | |
1578 | /* Remove from descriptor table. */ |
1579 | if (kn->kn_fop->f_isfd) |
1580 | list = (struct klist *)&fdp->fd_dt->dt_ff[kn->kn_id]->ff_knlist; |
1581 | else |
1582 | list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; |
1583 | |
1584 | SLIST_REMOVE(list, kn, knote, kn_link); |
1585 | |
1586 | /* Remove from kqueue. */ |
1587 | again: |
1588 | mutex_spin_enter(&kq->kq_lock); |
1589 | if ((kn->kn_status & KN_QUEUED) != 0) { |
1590 | kq_check(kq); |
1591 | kq->kq_count--; |
1592 | TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); |
1593 | kn->kn_status &= ~KN_QUEUED; |
1594 | kq_check(kq); |
1595 | } else if (kn->kn_status & KN_BUSY) { |
1596 | mutex_spin_exit(&kq->kq_lock); |
1597 | goto again; |
1598 | } |
1599 | mutex_spin_exit(&kq->kq_lock); |
1600 | |
1601 | mutex_exit(&fdp->fd_lock); |
1602 | if (kn->kn_fop->f_isfd) |
1603 | fd_putfile(kn->kn_id); |
1604 | atomic_dec_uint(&kn->kn_kfilter->refcnt); |
1605 | kmem_free(kn, sizeof(*kn)); |
1606 | } |
1607 | |
1608 | /* |
1609 | * Queue new event for knote. |
1610 | */ |
1611 | static void |
1612 | knote_enqueue(struct knote *kn) |
1613 | { |
1614 | struct kqueue *kq; |
1615 | |
1616 | KASSERT((kn->kn_status & KN_MARKER) == 0); |
1617 | |
1618 | kq = kn->kn_kq; |
1619 | |
1620 | mutex_spin_enter(&kq->kq_lock); |
1621 | if ((kn->kn_status & KN_DISABLED) != 0) { |
1622 | kn->kn_status &= ~KN_DISABLED; |
1623 | } |
1624 | if ((kn->kn_status & (KN_ACTIVE | KN_QUEUED)) == KN_ACTIVE) { |
1625 | kq_check(kq); |
1626 | kn->kn_status |= KN_QUEUED; |
1627 | TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); |
1628 | kq->kq_count++; |
1629 | kq_check(kq); |
1630 | cv_broadcast(&kq->kq_cv); |
1631 | selnotify(&kq->kq_sel, 0, NOTE_SUBMIT); |
1632 | } |
1633 | mutex_spin_exit(&kq->kq_lock); |
1634 | } |
1635 | /* |
1636 | * Queue new event for knote. |
1637 | */ |
1638 | static void |
1639 | knote_activate(struct knote *kn) |
1640 | { |
1641 | struct kqueue *kq; |
1642 | |
1643 | KASSERT((kn->kn_status & KN_MARKER) == 0); |
1644 | |
1645 | kq = kn->kn_kq; |
1646 | |
1647 | mutex_spin_enter(&kq->kq_lock); |
1648 | kn->kn_status |= KN_ACTIVE; |
1649 | if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) { |
1650 | kq_check(kq); |
1651 | kn->kn_status |= KN_QUEUED; |
1652 | TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); |
1653 | kq->kq_count++; |
1654 | kq_check(kq); |
1655 | cv_broadcast(&kq->kq_cv); |
1656 | selnotify(&kq->kq_sel, 0, NOTE_SUBMIT); |
1657 | } |
1658 | mutex_spin_exit(&kq->kq_lock); |
1659 | } |
1660 | |