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1/*
2 * Routines for driver control interface
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4 *
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 */
21
22#include <linux/threads.h>
23#include <linux/interrupt.h>
24#include <linux/module.h>
25#include <linux/slab.h>
26#include <linux/vmalloc.h>
27#include <linux/time.h>
28#include <sound/core.h>
29#include <sound/minors.h>
30#include <sound/info.h>
31#include <sound/control.h>
32
33/* max number of user-defined controls */
34#define MAX_USER_CONTROLS 32
35#define MAX_CONTROL_COUNT 1028
36
37struct snd_kctl_ioctl {
38 struct list_head list; /* list of all ioctls */
39 snd_kctl_ioctl_func_t fioctl;
40};
41
42static DECLARE_RWSEM(snd_ioctl_rwsem);
43static LIST_HEAD(snd_control_ioctls);
44#ifdef CONFIG_COMPAT
45static LIST_HEAD(snd_control_compat_ioctls);
46#endif
47
48static int snd_ctl_open(struct inode *inode, struct file *file)
49{
50 unsigned long flags;
51 struct snd_card *card;
52 struct snd_ctl_file *ctl;
53 int i, err;
54
55 err = nonseekable_open(inode, file);
56 if (err < 0)
57 return err;
58
59 card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
60 if (!card) {
61 err = -ENODEV;
62 goto __error1;
63 }
64 err = snd_card_file_add(card, file);
65 if (err < 0) {
66 err = -ENODEV;
67 goto __error1;
68 }
69 if (!try_module_get(card->module)) {
70 err = -EFAULT;
71 goto __error2;
72 }
73 ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
74 if (ctl == NULL) {
75 err = -ENOMEM;
76 goto __error;
77 }
78 INIT_LIST_HEAD(&ctl->events);
79 init_waitqueue_head(&ctl->change_sleep);
80 spin_lock_init(&ctl->read_lock);
81 ctl->card = card;
82 for (i = 0; i < SND_CTL_SUBDEV_ITEMS; i++)
83 ctl->preferred_subdevice[i] = -1;
84 ctl->pid = get_pid(task_pid(current));
85 file->private_data = ctl;
86 write_lock_irqsave(&card->ctl_files_rwlock, flags);
87 list_add_tail(&ctl->list, &card->ctl_files);
88 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
89 snd_card_unref(card);
90 return 0;
91
92 __error:
93 module_put(card->module);
94 __error2:
95 snd_card_file_remove(card, file);
96 __error1:
97 if (card)
98 snd_card_unref(card);
99 return err;
100}
101
102static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
103{
104 unsigned long flags;
105 struct snd_kctl_event *cread;
106
107 spin_lock_irqsave(&ctl->read_lock, flags);
108 while (!list_empty(&ctl->events)) {
109 cread = snd_kctl_event(ctl->events.next);
110 list_del(&cread->list);
111 kfree(cread);
112 }
113 spin_unlock_irqrestore(&ctl->read_lock, flags);
114}
115
116static int snd_ctl_release(struct inode *inode, struct file *file)
117{
118 unsigned long flags;
119 struct snd_card *card;
120 struct snd_ctl_file *ctl;
121 struct snd_kcontrol *control;
122 unsigned int idx;
123
124 ctl = file->private_data;
125 file->private_data = NULL;
126 card = ctl->card;
127 write_lock_irqsave(&card->ctl_files_rwlock, flags);
128 list_del(&ctl->list);
129 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
130 down_write(&card->controls_rwsem);
131 list_for_each_entry(control, &card->controls, list)
132 for (idx = 0; idx < control->count; idx++)
133 if (control->vd[idx].owner == ctl)
134 control->vd[idx].owner = NULL;
135 up_write(&card->controls_rwsem);
136 snd_ctl_empty_read_queue(ctl);
137 put_pid(ctl->pid);
138 kfree(ctl);
139 module_put(card->module);
140 snd_card_file_remove(card, file);
141 return 0;
142}
143
144/**
145 * snd_ctl_notify - Send notification to user-space for a control change
146 * @card: the card to send notification
147 * @mask: the event mask, SNDRV_CTL_EVENT_*
148 * @id: the ctl element id to send notification
149 *
150 * This function adds an event record with the given id and mask, appends
151 * to the list and wakes up the user-space for notification. This can be
152 * called in the atomic context.
153 */
154void snd_ctl_notify(struct snd_card *card, unsigned int mask,
155 struct snd_ctl_elem_id *id)
156{
157 unsigned long flags;
158 struct snd_ctl_file *ctl;
159 struct snd_kctl_event *ev;
160
161 if (snd_BUG_ON(!card || !id))
162 return;
163 read_lock(&card->ctl_files_rwlock);
164#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
165 card->mixer_oss_change_count++;
166#endif
167 list_for_each_entry(ctl, &card->ctl_files, list) {
168 if (!ctl->subscribed)
169 continue;
170 spin_lock_irqsave(&ctl->read_lock, flags);
171 list_for_each_entry(ev, &ctl->events, list) {
172 if (ev->id.numid == id->numid) {
173 ev->mask |= mask;
174 goto _found;
175 }
176 }
177 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
178 if (ev) {
179 ev->id = *id;
180 ev->mask = mask;
181 list_add_tail(&ev->list, &ctl->events);
182 } else {
183 dev_err(card->dev, "No memory available to allocate event\n");
184 }
185 _found:
186 wake_up(&ctl->change_sleep);
187 spin_unlock_irqrestore(&ctl->read_lock, flags);
188 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
189 }
190 read_unlock(&card->ctl_files_rwlock);
191}
192EXPORT_SYMBOL(snd_ctl_notify);
193
194/**
195 * snd_ctl_new - create a new control instance with some elements
196 * @kctl: the pointer to store new control instance
197 * @count: the number of elements in this control
198 * @access: the default access flags for elements in this control
199 * @file: given when locking these elements
200 *
201 * Allocates a memory object for a new control instance. The instance has
202 * elements as many as the given number (@count). Each element has given
203 * access permissions (@access). Each element is locked when @file is given.
204 *
205 * Return: 0 on success, error code on failure
206 */
207static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count,
208 unsigned int access, struct snd_ctl_file *file)
209{
210 unsigned int size;
211 unsigned int idx;
212
213 if (count == 0 || count > MAX_CONTROL_COUNT)
214 return -EINVAL;
215
216 size = sizeof(struct snd_kcontrol);
217 size += sizeof(struct snd_kcontrol_volatile) * count;
218
219 *kctl = kzalloc(size, GFP_KERNEL);
220 if (!*kctl)
221 return -ENOMEM;
222
223 for (idx = 0; idx < count; idx++) {
224 (*kctl)->vd[idx].access = access;
225 (*kctl)->vd[idx].owner = file;
226 }
227 (*kctl)->count = count;
228
229 return 0;
230}
231
232/**
233 * snd_ctl_new1 - create a control instance from the template
234 * @ncontrol: the initialization record
235 * @private_data: the private data to set
236 *
237 * Allocates a new struct snd_kcontrol instance and initialize from the given
238 * template. When the access field of ncontrol is 0, it's assumed as
239 * READWRITE access. When the count field is 0, it's assumes as one.
240 *
241 * Return: The pointer of the newly generated instance, or %NULL on failure.
242 */
243struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
244 void *private_data)
245{
246 struct snd_kcontrol *kctl;
247 unsigned int count;
248 unsigned int access;
249 int err;
250
251 if (snd_BUG_ON(!ncontrol || !ncontrol->info))
252 return NULL;
253
254 count = ncontrol->count;
255 if (count == 0)
256 count = 1;
257
258 access = ncontrol->access;
259 if (access == 0)
260 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
261 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
262 SNDRV_CTL_ELEM_ACCESS_VOLATILE |
263 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
264 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE |
265 SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND |
266 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK);
267
268 err = snd_ctl_new(&kctl, count, access, NULL);
269 if (err < 0)
270 return NULL;
271
272 /* The 'numid' member is decided when calling snd_ctl_add(). */
273 kctl->id.iface = ncontrol->iface;
274 kctl->id.device = ncontrol->device;
275 kctl->id.subdevice = ncontrol->subdevice;
276 if (ncontrol->name) {
277 strlcpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.name));
278 if (strcmp(ncontrol->name, kctl->id.name) != 0)
279 pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
280 ncontrol->name, kctl->id.name);
281 }
282 kctl->id.index = ncontrol->index;
283
284 kctl->info = ncontrol->info;
285 kctl->get = ncontrol->get;
286 kctl->put = ncontrol->put;
287 kctl->tlv.p = ncontrol->tlv.p;
288
289 kctl->private_value = ncontrol->private_value;
290 kctl->private_data = private_data;
291
292 return kctl;
293}
294EXPORT_SYMBOL(snd_ctl_new1);
295
296/**
297 * snd_ctl_free_one - release the control instance
298 * @kcontrol: the control instance
299 *
300 * Releases the control instance created via snd_ctl_new()
301 * or snd_ctl_new1().
302 * Don't call this after the control was added to the card.
303 */
304void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
305{
306 if (kcontrol) {
307 if (kcontrol->private_free)
308 kcontrol->private_free(kcontrol);
309 kfree(kcontrol);
310 }
311}
312EXPORT_SYMBOL(snd_ctl_free_one);
313
314static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
315 unsigned int count)
316{
317 struct snd_kcontrol *kctl;
318
319 /* Make sure that the ids assigned to the control do not wrap around */
320 if (card->last_numid >= UINT_MAX - count)
321 card->last_numid = 0;
322
323 list_for_each_entry(kctl, &card->controls, list) {
324 if (kctl->id.numid < card->last_numid + 1 + count &&
325 kctl->id.numid + kctl->count > card->last_numid + 1) {
326 card->last_numid = kctl->id.numid + kctl->count - 1;
327 return true;
328 }
329 }
330 return false;
331}
332
333static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
334{
335 unsigned int iter = 100000;
336
337 while (snd_ctl_remove_numid_conflict(card, count)) {
338 if (--iter == 0) {
339 /* this situation is very unlikely */
340 dev_err(card->dev, "unable to allocate new control numid\n");
341 return -ENOMEM;
342 }
343 }
344 return 0;
345}
346
347/**
348 * snd_ctl_add - add the control instance to the card
349 * @card: the card instance
350 * @kcontrol: the control instance to add
351 *
352 * Adds the control instance created via snd_ctl_new() or
353 * snd_ctl_new1() to the given card. Assigns also an unique
354 * numid used for fast search.
355 *
356 * It frees automatically the control which cannot be added.
357 *
358 * Return: Zero if successful, or a negative error code on failure.
359 *
360 */
361int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
362{
363 struct snd_ctl_elem_id id;
364 unsigned int idx;
365 unsigned int count;
366 int err = -EINVAL;
367
368 if (! kcontrol)
369 return err;
370 if (snd_BUG_ON(!card || !kcontrol->info))
371 goto error;
372 id = kcontrol->id;
373 if (id.index > UINT_MAX - kcontrol->count)
374 goto error;
375
376 down_write(&card->controls_rwsem);
377 if (snd_ctl_find_id(card, &id)) {
378 up_write(&card->controls_rwsem);
379 dev_err(card->dev, "control %i:%i:%i:%s:%i is already present\n",
380 id.iface,
381 id.device,
382 id.subdevice,
383 id.name,
384 id.index);
385 err = -EBUSY;
386 goto error;
387 }
388 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
389 up_write(&card->controls_rwsem);
390 err = -ENOMEM;
391 goto error;
392 }
393 list_add_tail(&kcontrol->list, &card->controls);
394 card->controls_count += kcontrol->count;
395 kcontrol->id.numid = card->last_numid + 1;
396 card->last_numid += kcontrol->count;
397 id = kcontrol->id;
398 count = kcontrol->count;
399 up_write(&card->controls_rwsem);
400 for (idx = 0; idx < count; idx++, id.index++, id.numid++)
401 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
402 return 0;
403
404 error:
405 snd_ctl_free_one(kcontrol);
406 return err;
407}
408EXPORT_SYMBOL(snd_ctl_add);
409
410/**
411 * snd_ctl_replace - replace the control instance of the card
412 * @card: the card instance
413 * @kcontrol: the control instance to replace
414 * @add_on_replace: add the control if not already added
415 *
416 * Replaces the given control. If the given control does not exist
417 * and the add_on_replace flag is set, the control is added. If the
418 * control exists, it is destroyed first.
419 *
420 * It frees automatically the control which cannot be added or replaced.
421 *
422 * Return: Zero if successful, or a negative error code on failure.
423 */
424int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
425 bool add_on_replace)
426{
427 struct snd_ctl_elem_id id;
428 unsigned int count;
429 unsigned int idx;
430 struct snd_kcontrol *old;
431 int ret;
432
433 if (!kcontrol)
434 return -EINVAL;
435 if (snd_BUG_ON(!card || !kcontrol->info)) {
436 ret = -EINVAL;
437 goto error;
438 }
439 id = kcontrol->id;
440 down_write(&card->controls_rwsem);
441 old = snd_ctl_find_id(card, &id);
442 if (!old) {
443 if (add_on_replace)
444 goto add;
445 up_write(&card->controls_rwsem);
446 ret = -EINVAL;
447 goto error;
448 }
449 ret = snd_ctl_remove(card, old);
450 if (ret < 0) {
451 up_write(&card->controls_rwsem);
452 goto error;
453 }
454add:
455 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
456 up_write(&card->controls_rwsem);
457 ret = -ENOMEM;
458 goto error;
459 }
460 list_add_tail(&kcontrol->list, &card->controls);
461 card->controls_count += kcontrol->count;
462 kcontrol->id.numid = card->last_numid + 1;
463 card->last_numid += kcontrol->count;
464 id = kcontrol->id;
465 count = kcontrol->count;
466 up_write(&card->controls_rwsem);
467 for (idx = 0; idx < count; idx++, id.index++, id.numid++)
468 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
469 return 0;
470
471error:
472 snd_ctl_free_one(kcontrol);
473 return ret;
474}
475EXPORT_SYMBOL(snd_ctl_replace);
476
477/**
478 * snd_ctl_remove - remove the control from the card and release it
479 * @card: the card instance
480 * @kcontrol: the control instance to remove
481 *
482 * Removes the control from the card and then releases the instance.
483 * You don't need to call snd_ctl_free_one(). You must be in
484 * the write lock - down_write(&card->controls_rwsem).
485 *
486 * Return: 0 if successful, or a negative error code on failure.
487 */
488int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
489{
490 struct snd_ctl_elem_id id;
491 unsigned int idx;
492
493 if (snd_BUG_ON(!card || !kcontrol))
494 return -EINVAL;
495 list_del(&kcontrol->list);
496 card->controls_count -= kcontrol->count;
497 id = kcontrol->id;
498 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
499 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
500 snd_ctl_free_one(kcontrol);
501 return 0;
502}
503EXPORT_SYMBOL(snd_ctl_remove);
504
505/**
506 * snd_ctl_remove_id - remove the control of the given id and release it
507 * @card: the card instance
508 * @id: the control id to remove
509 *
510 * Finds the control instance with the given id, removes it from the
511 * card list and releases it.
512 *
513 * Return: 0 if successful, or a negative error code on failure.
514 */
515int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
516{
517 struct snd_kcontrol *kctl;
518 int ret;
519
520 down_write(&card->controls_rwsem);
521 kctl = snd_ctl_find_id(card, id);
522 if (kctl == NULL) {
523 up_write(&card->controls_rwsem);
524 return -ENOENT;
525 }
526 ret = snd_ctl_remove(card, kctl);
527 up_write(&card->controls_rwsem);
528 return ret;
529}
530EXPORT_SYMBOL(snd_ctl_remove_id);
531
532/**
533 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
534 * @file: active control handle
535 * @id: the control id to remove
536 *
537 * Finds the control instance with the given id, removes it from the
538 * card list and releases it.
539 *
540 * Return: 0 if successful, or a negative error code on failure.
541 */
542static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
543 struct snd_ctl_elem_id *id)
544{
545 struct snd_card *card = file->card;
546 struct snd_kcontrol *kctl;
547 int idx, ret;
548
549 down_write(&card->controls_rwsem);
550 kctl = snd_ctl_find_id(card, id);
551 if (kctl == NULL) {
552 ret = -ENOENT;
553 goto error;
554 }
555 if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
556 ret = -EINVAL;
557 goto error;
558 }
559 for (idx = 0; idx < kctl->count; idx++)
560 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
561 ret = -EBUSY;
562 goto error;
563 }
564 ret = snd_ctl_remove(card, kctl);
565 if (ret < 0)
566 goto error;
567 card->user_ctl_count--;
568error:
569 up_write(&card->controls_rwsem);
570 return ret;
571}
572
573/**
574 * snd_ctl_activate_id - activate/inactivate the control of the given id
575 * @card: the card instance
576 * @id: the control id to activate/inactivate
577 * @active: non-zero to activate
578 *
579 * Finds the control instance with the given id, and activate or
580 * inactivate the control together with notification, if changed.
581 * The given ID data is filled with full information.
582 *
583 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
584 */
585int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
586 int active)
587{
588 struct snd_kcontrol *kctl;
589 struct snd_kcontrol_volatile *vd;
590 unsigned int index_offset;
591 int ret;
592
593 down_write(&card->controls_rwsem);
594 kctl = snd_ctl_find_id(card, id);
595 if (kctl == NULL) {
596 ret = -ENOENT;
597 goto unlock;
598 }
599 index_offset = snd_ctl_get_ioff(kctl, id);
600 vd = &kctl->vd[index_offset];
601 ret = 0;
602 if (active) {
603 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
604 goto unlock;
605 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
606 } else {
607 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
608 goto unlock;
609 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
610 }
611 snd_ctl_build_ioff(id, kctl, index_offset);
612 ret = 1;
613 unlock:
614 up_write(&card->controls_rwsem);
615 if (ret > 0)
616 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
617 return ret;
618}
619EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
620
621/**
622 * snd_ctl_rename_id - replace the id of a control on the card
623 * @card: the card instance
624 * @src_id: the old id
625 * @dst_id: the new id
626 *
627 * Finds the control with the old id from the card, and replaces the
628 * id with the new one.
629 *
630 * Return: Zero if successful, or a negative error code on failure.
631 */
632int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
633 struct snd_ctl_elem_id *dst_id)
634{
635 struct snd_kcontrol *kctl;
636
637 down_write(&card->controls_rwsem);
638 kctl = snd_ctl_find_id(card, src_id);
639 if (kctl == NULL) {
640 up_write(&card->controls_rwsem);
641 return -ENOENT;
642 }
643 kctl->id = *dst_id;
644 kctl->id.numid = card->last_numid + 1;
645 card->last_numid += kctl->count;
646 up_write(&card->controls_rwsem);
647 return 0;
648}
649EXPORT_SYMBOL(snd_ctl_rename_id);
650
651/**
652 * snd_ctl_find_numid - find the control instance with the given number-id
653 * @card: the card instance
654 * @numid: the number-id to search
655 *
656 * Finds the control instance with the given number-id from the card.
657 *
658 * The caller must down card->controls_rwsem before calling this function
659 * (if the race condition can happen).
660 *
661 * Return: The pointer of the instance if found, or %NULL if not.
662 *
663 */
664struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
665{
666 struct snd_kcontrol *kctl;
667
668 if (snd_BUG_ON(!card || !numid))
669 return NULL;
670 list_for_each_entry(kctl, &card->controls, list) {
671 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
672 return kctl;
673 }
674 return NULL;
675}
676EXPORT_SYMBOL(snd_ctl_find_numid);
677
678/**
679 * snd_ctl_find_id - find the control instance with the given id
680 * @card: the card instance
681 * @id: the id to search
682 *
683 * Finds the control instance with the given id from the card.
684 *
685 * The caller must down card->controls_rwsem before calling this function
686 * (if the race condition can happen).
687 *
688 * Return: The pointer of the instance if found, or %NULL if not.
689 *
690 */
691struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
692 struct snd_ctl_elem_id *id)
693{
694 struct snd_kcontrol *kctl;
695
696 if (snd_BUG_ON(!card || !id))
697 return NULL;
698 if (id->numid != 0)
699 return snd_ctl_find_numid(card, id->numid);
700 list_for_each_entry(kctl, &card->controls, list) {
701 if (kctl->id.iface != id->iface)
702 continue;
703 if (kctl->id.device != id->device)
704 continue;
705 if (kctl->id.subdevice != id->subdevice)
706 continue;
707 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
708 continue;
709 if (kctl->id.index > id->index)
710 continue;
711 if (kctl->id.index + kctl->count <= id->index)
712 continue;
713 return kctl;
714 }
715 return NULL;
716}
717EXPORT_SYMBOL(snd_ctl_find_id);
718
719static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
720 unsigned int cmd, void __user *arg)
721{
722 struct snd_ctl_card_info *info;
723
724 info = kzalloc(sizeof(*info), GFP_KERNEL);
725 if (! info)
726 return -ENOMEM;
727 down_read(&snd_ioctl_rwsem);
728 info->card = card->number;
729 strlcpy(info->id, card->id, sizeof(info->id));
730 strlcpy(info->driver, card->driver, sizeof(info->driver));
731 strlcpy(info->name, card->shortname, sizeof(info->name));
732 strlcpy(info->longname, card->longname, sizeof(info->longname));
733 strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
734 strlcpy(info->components, card->components, sizeof(info->components));
735 up_read(&snd_ioctl_rwsem);
736 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
737 kfree(info);
738 return -EFAULT;
739 }
740 kfree(info);
741 return 0;
742}
743
744static int snd_ctl_elem_list(struct snd_card *card,
745 struct snd_ctl_elem_list __user *_list)
746{
747 struct list_head *plist;
748 struct snd_ctl_elem_list list;
749 struct snd_kcontrol *kctl;
750 struct snd_ctl_elem_id *dst, *id;
751 unsigned int offset, space, jidx;
752
753 if (copy_from_user(&list, _list, sizeof(list)))
754 return -EFAULT;
755 offset = list.offset;
756 space = list.space;
757 /* try limit maximum space */
758 if (space > 16384)
759 return -ENOMEM;
760 if (space > 0) {
761 /* allocate temporary buffer for atomic operation */
762 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
763 if (dst == NULL)
764 return -ENOMEM;
765 down_read(&card->controls_rwsem);
766 list.count = card->controls_count;
767 plist = card->controls.next;
768 while (plist != &card->controls) {
769 if (offset == 0)
770 break;
771 kctl = snd_kcontrol(plist);
772 if (offset < kctl->count)
773 break;
774 offset -= kctl->count;
775 plist = plist->next;
776 }
777 list.used = 0;
778 id = dst;
779 while (space > 0 && plist != &card->controls) {
780 kctl = snd_kcontrol(plist);
781 for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
782 snd_ctl_build_ioff(id, kctl, jidx);
783 id++;
784 space--;
785 list.used++;
786 }
787 plist = plist->next;
788 offset = 0;
789 }
790 up_read(&card->controls_rwsem);
791 if (list.used > 0 &&
792 copy_to_user(list.pids, dst,
793 list.used * sizeof(struct snd_ctl_elem_id))) {
794 vfree(dst);
795 return -EFAULT;
796 }
797 vfree(dst);
798 } else {
799 down_read(&card->controls_rwsem);
800 list.count = card->controls_count;
801 up_read(&card->controls_rwsem);
802 }
803 if (copy_to_user(_list, &list, sizeof(list)))
804 return -EFAULT;
805 return 0;
806}
807
808static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
809 struct snd_ctl_elem_info *info)
810{
811 struct snd_card *card = ctl->card;
812 struct snd_kcontrol *kctl;
813 struct snd_kcontrol_volatile *vd;
814 unsigned int index_offset;
815 int result;
816
817 down_read(&card->controls_rwsem);
818 kctl = snd_ctl_find_id(card, &info->id);
819 if (kctl == NULL) {
820 up_read(&card->controls_rwsem);
821 return -ENOENT;
822 }
823#ifdef CONFIG_SND_DEBUG
824 info->access = 0;
825#endif
826 result = kctl->info(kctl, info);
827 if (result >= 0) {
828 snd_BUG_ON(info->access);
829 index_offset = snd_ctl_get_ioff(kctl, &info->id);
830 vd = &kctl->vd[index_offset];
831 snd_ctl_build_ioff(&info->id, kctl, index_offset);
832 info->access = vd->access;
833 if (vd->owner) {
834 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
835 if (vd->owner == ctl)
836 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
837 info->owner = pid_vnr(vd->owner->pid);
838 } else {
839 info->owner = -1;
840 }
841 }
842 up_read(&card->controls_rwsem);
843 return result;
844}
845
846static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
847 struct snd_ctl_elem_info __user *_info)
848{
849 struct snd_ctl_elem_info info;
850 int result;
851
852 if (copy_from_user(&info, _info, sizeof(info)))
853 return -EFAULT;
854 snd_power_lock(ctl->card);
855 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
856 if (result >= 0)
857 result = snd_ctl_elem_info(ctl, &info);
858 snd_power_unlock(ctl->card);
859 if (result >= 0)
860 if (copy_to_user(_info, &info, sizeof(info)))
861 return -EFAULT;
862 return result;
863}
864
865static int snd_ctl_elem_read(struct snd_card *card,
866 struct snd_ctl_elem_value *control)
867{
868 struct snd_kcontrol *kctl;
869 struct snd_kcontrol_volatile *vd;
870 unsigned int index_offset;
871 int result;
872
873 down_read(&card->controls_rwsem);
874 kctl = snd_ctl_find_id(card, &control->id);
875 if (kctl == NULL) {
876 result = -ENOENT;
877 } else {
878 index_offset = snd_ctl_get_ioff(kctl, &control->id);
879 vd = &kctl->vd[index_offset];
880 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
881 kctl->get != NULL) {
882 snd_ctl_build_ioff(&control->id, kctl, index_offset);
883 result = kctl->get(kctl, control);
884 } else
885 result = -EPERM;
886 }
887 up_read(&card->controls_rwsem);
888 return result;
889}
890
891static int snd_ctl_elem_read_user(struct snd_card *card,
892 struct snd_ctl_elem_value __user *_control)
893{
894 struct snd_ctl_elem_value *control;
895 int result;
896
897 control = memdup_user(_control, sizeof(*control));
898 if (IS_ERR(control))
899 return PTR_ERR(control);
900
901 snd_power_lock(card);
902 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
903 if (result >= 0)
904 result = snd_ctl_elem_read(card, control);
905 snd_power_unlock(card);
906 if (result >= 0)
907 if (copy_to_user(_control, control, sizeof(*control)))
908 result = -EFAULT;
909 kfree(control);
910 return result;
911}
912
913static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
914 struct snd_ctl_elem_value *control)
915{
916 struct snd_kcontrol *kctl;
917 struct snd_kcontrol_volatile *vd;
918 unsigned int index_offset;
919 int result;
920
921 down_read(&card->controls_rwsem);
922 kctl = snd_ctl_find_id(card, &control->id);
923 if (kctl == NULL) {
924 result = -ENOENT;
925 } else {
926 index_offset = snd_ctl_get_ioff(kctl, &control->id);
927 vd = &kctl->vd[index_offset];
928 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
929 kctl->put == NULL ||
930 (file && vd->owner && vd->owner != file)) {
931 result = -EPERM;
932 } else {
933 snd_ctl_build_ioff(&control->id, kctl, index_offset);
934 result = kctl->put(kctl, control);
935 }
936 if (result > 0) {
937 struct snd_ctl_elem_id id = control->id;
938 up_read(&card->controls_rwsem);
939 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
940 return 0;
941 }
942 }
943 up_read(&card->controls_rwsem);
944 return result;
945}
946
947static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
948 struct snd_ctl_elem_value __user *_control)
949{
950 struct snd_ctl_elem_value *control;
951 struct snd_card *card;
952 int result;
953
954 control = memdup_user(_control, sizeof(*control));
955 if (IS_ERR(control))
956 return PTR_ERR(control);
957
958 card = file->card;
959 snd_power_lock(card);
960 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
961 if (result >= 0)
962 result = snd_ctl_elem_write(card, file, control);
963 snd_power_unlock(card);
964 if (result >= 0)
965 if (copy_to_user(_control, control, sizeof(*control)))
966 result = -EFAULT;
967 kfree(control);
968 return result;
969}
970
971static int snd_ctl_elem_lock(struct snd_ctl_file *file,
972 struct snd_ctl_elem_id __user *_id)
973{
974 struct snd_card *card = file->card;
975 struct snd_ctl_elem_id id;
976 struct snd_kcontrol *kctl;
977 struct snd_kcontrol_volatile *vd;
978 int result;
979
980 if (copy_from_user(&id, _id, sizeof(id)))
981 return -EFAULT;
982 down_write(&card->controls_rwsem);
983 kctl = snd_ctl_find_id(card, &id);
984 if (kctl == NULL) {
985 result = -ENOENT;
986 } else {
987 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
988 if (vd->owner != NULL)
989 result = -EBUSY;
990 else {
991 vd->owner = file;
992 result = 0;
993 }
994 }
995 up_write(&card->controls_rwsem);
996 return result;
997}
998
999static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
1000 struct snd_ctl_elem_id __user *_id)
1001{
1002 struct snd_card *card = file->card;
1003 struct snd_ctl_elem_id id;
1004 struct snd_kcontrol *kctl;
1005 struct snd_kcontrol_volatile *vd;
1006 int result;
1007
1008 if (copy_from_user(&id, _id, sizeof(id)))
1009 return -EFAULT;
1010 down_write(&card->controls_rwsem);
1011 kctl = snd_ctl_find_id(card, &id);
1012 if (kctl == NULL) {
1013 result = -ENOENT;
1014 } else {
1015 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1016 if (vd->owner == NULL)
1017 result = -EINVAL;
1018 else if (vd->owner != file)
1019 result = -EPERM;
1020 else {
1021 vd->owner = NULL;
1022 result = 0;
1023 }
1024 }
1025 up_write(&card->controls_rwsem);
1026 return result;
1027}
1028
1029struct user_element {
1030 struct snd_ctl_elem_info info;
1031 struct snd_card *card;
1032 char *elem_data; /* element data */
1033 unsigned long elem_data_size; /* size of element data in bytes */
1034 void *tlv_data; /* TLV data */
1035 unsigned long tlv_data_size; /* TLV data size */
1036 void *priv_data; /* private data (like strings for enumerated type) */
1037};
1038
1039static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1040 struct snd_ctl_elem_info *uinfo)
1041{
1042 struct user_element *ue = kcontrol->private_data;
1043 unsigned int offset;
1044
1045 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1046 *uinfo = ue->info;
1047 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1048
1049 return 0;
1050}
1051
1052static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1053 struct snd_ctl_elem_info *uinfo)
1054{
1055 struct user_element *ue = kcontrol->private_data;
1056 const char *names;
1057 unsigned int item;
1058 unsigned int offset;
1059
1060 item = uinfo->value.enumerated.item;
1061
1062 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1063 *uinfo = ue->info;
1064 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1065
1066 item = min(item, uinfo->value.enumerated.items - 1);
1067 uinfo->value.enumerated.item = item;
1068
1069 names = ue->priv_data;
1070 for (; item > 0; --item)
1071 names += strlen(names) + 1;
1072 strcpy(uinfo->value.enumerated.name, names);
1073
1074 return 0;
1075}
1076
1077static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1078 struct snd_ctl_elem_value *ucontrol)
1079{
1080 struct user_element *ue = kcontrol->private_data;
1081 unsigned int size = ue->elem_data_size;
1082 char *src = ue->elem_data +
1083 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1084
1085 mutex_lock(&ue->card->user_ctl_lock);
1086 memcpy(&ucontrol->value, src, size);
1087 mutex_unlock(&ue->card->user_ctl_lock);
1088 return 0;
1089}
1090
1091static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1092 struct snd_ctl_elem_value *ucontrol)
1093{
1094 int change;
1095 struct user_element *ue = kcontrol->private_data;
1096 unsigned int size = ue->elem_data_size;
1097 char *dst = ue->elem_data +
1098 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1099
1100 mutex_lock(&ue->card->user_ctl_lock);
1101 change = memcmp(&ucontrol->value, dst, size) != 0;
1102 if (change)
1103 memcpy(dst, &ucontrol->value, size);
1104 mutex_unlock(&ue->card->user_ctl_lock);
1105 return change;
1106}
1107
1108static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1109 int op_flag,
1110 unsigned int size,
1111 unsigned int __user *tlv)
1112{
1113 struct user_element *ue = kcontrol->private_data;
1114 int change = 0;
1115 void *new_data;
1116
1117 if (op_flag == SNDRV_CTL_TLV_OP_WRITE) {
1118 if (size > 1024 * 128) /* sane value */
1119 return -EINVAL;
1120
1121 new_data = memdup_user(tlv, size);
1122 if (IS_ERR(new_data))
1123 return PTR_ERR(new_data);
1124 mutex_lock(&ue->card->user_ctl_lock);
1125 change = ue->tlv_data_size != size;
1126 if (!change)
1127 change = memcmp(ue->tlv_data, new_data, size);
1128 kfree(ue->tlv_data);
1129 ue->tlv_data = new_data;
1130 ue->tlv_data_size = size;
1131 mutex_unlock(&ue->card->user_ctl_lock);
1132 } else {
1133 int ret = 0;
1134
1135 mutex_lock(&ue->card->user_ctl_lock);
1136 if (!ue->tlv_data_size || !ue->tlv_data) {
1137 ret = -ENXIO;
1138 goto err_unlock;
1139 }
1140 if (size < ue->tlv_data_size) {
1141 ret = -ENOSPC;
1142 goto err_unlock;
1143 }
1144 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1145 ret = -EFAULT;
1146err_unlock:
1147 mutex_unlock(&ue->card->user_ctl_lock);
1148 if (ret)
1149 return ret;
1150 }
1151 return change;
1152}
1153
1154static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1155{
1156 char *names, *p;
1157 size_t buf_len, name_len;
1158 unsigned int i;
1159 const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1160
1161 if (ue->info.value.enumerated.names_length > 64 * 1024)
1162 return -EINVAL;
1163
1164 names = memdup_user((const void __user *)user_ptrval,
1165 ue->info.value.enumerated.names_length);
1166 if (IS_ERR(names))
1167 return PTR_ERR(names);
1168
1169 /* check that there are enough valid names */
1170 buf_len = ue->info.value.enumerated.names_length;
1171 p = names;
1172 for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1173 name_len = strnlen(p, buf_len);
1174 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1175 kfree(names);
1176 return -EINVAL;
1177 }
1178 p += name_len + 1;
1179 buf_len -= name_len + 1;
1180 }
1181
1182 ue->priv_data = names;
1183 ue->info.value.enumerated.names_ptr = 0;
1184
1185 return 0;
1186}
1187
1188static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1189{
1190 struct user_element *ue = kcontrol->private_data;
1191
1192 kfree(ue->tlv_data);
1193 kfree(ue->priv_data);
1194 kfree(ue);
1195}
1196
1197static int snd_ctl_elem_add(struct snd_ctl_file *file,
1198 struct snd_ctl_elem_info *info, int replace)
1199{
1200 /* The capacity of struct snd_ctl_elem_value.value.*/
1201 static const unsigned int value_sizes[] = {
1202 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = sizeof(long),
1203 [SNDRV_CTL_ELEM_TYPE_INTEGER] = sizeof(long),
1204 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = sizeof(unsigned int),
1205 [SNDRV_CTL_ELEM_TYPE_BYTES] = sizeof(unsigned char),
1206 [SNDRV_CTL_ELEM_TYPE_IEC958] = sizeof(struct snd_aes_iec958),
1207 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long),
1208 };
1209 static const unsigned int max_value_counts[] = {
1210 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = 128,
1211 [SNDRV_CTL_ELEM_TYPE_INTEGER] = 128,
1212 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = 128,
1213 [SNDRV_CTL_ELEM_TYPE_BYTES] = 512,
1214 [SNDRV_CTL_ELEM_TYPE_IEC958] = 1,
1215 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64,
1216 };
1217 struct snd_card *card = file->card;
1218 struct snd_kcontrol *kctl;
1219 unsigned int count;
1220 unsigned int access;
1221 long private_size;
1222 struct user_element *ue;
1223 unsigned int offset;
1224 int err;
1225
1226 if (!*info->id.name)
1227 return -EINVAL;
1228 if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
1229 return -EINVAL;
1230
1231 /* Delete a control to replace them if needed. */
1232 if (replace) {
1233 info->id.numid = 0;
1234 err = snd_ctl_remove_user_ctl(file, &info->id);
1235 if (err)
1236 return err;
1237 }
1238
1239 /*
1240 * The number of userspace controls are counted control by control,
1241 * not element by element.
1242 */
1243 if (card->user_ctl_count + 1 > MAX_USER_CONTROLS)
1244 return -ENOMEM;
1245
1246 /* Check the number of elements for this userspace control. */
1247 count = info->owner;
1248 if (count == 0)
1249 count = 1;
1250
1251 /* Arrange access permissions if needed. */
1252 access = info->access;
1253 if (access == 0)
1254 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
1255 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
1256 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
1257 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE);
1258 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE)
1259 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1260 access |= SNDRV_CTL_ELEM_ACCESS_USER;
1261
1262 /*
1263 * Check information and calculate the size of data specific to
1264 * this userspace control.
1265 */
1266 if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
1267 info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64)
1268 return -EINVAL;
1269 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED &&
1270 info->value.enumerated.items == 0)
1271 return -EINVAL;
1272 if (info->count < 1 ||
1273 info->count > max_value_counts[info->type])
1274 return -EINVAL;
1275 private_size = value_sizes[info->type] * info->count;
1276
1277 /*
1278 * Keep memory object for this userspace control. After passing this
1279 * code block, the instance should be freed by snd_ctl_free_one().
1280 *
1281 * Note that these elements in this control are locked.
1282 */
1283 err = snd_ctl_new(&kctl, count, access, file);
1284 if (err < 0)
1285 return err;
1286 memcpy(&kctl->id, &info->id, sizeof(kctl->id));
1287 kctl->private_data = kzalloc(sizeof(struct user_element) + private_size * count,
1288 GFP_KERNEL);
1289 if (kctl->private_data == NULL) {
1290 kfree(kctl);
1291 return -ENOMEM;
1292 }
1293 kctl->private_free = snd_ctl_elem_user_free;
1294
1295 /* Set private data for this userspace control. */
1296 ue = (struct user_element *)kctl->private_data;
1297 ue->card = card;
1298 ue->info = *info;
1299 ue->info.access = 0;
1300 ue->elem_data = (char *)ue + sizeof(*ue);
1301 ue->elem_data_size = private_size;
1302 if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1303 err = snd_ctl_elem_init_enum_names(ue);
1304 if (err < 0) {
1305 snd_ctl_free_one(kctl);
1306 return err;
1307 }
1308 }
1309
1310 /* Set callback functions. */
1311 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1312 kctl->info = snd_ctl_elem_user_enum_info;
1313 else
1314 kctl->info = snd_ctl_elem_user_info;
1315 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1316 kctl->get = snd_ctl_elem_user_get;
1317 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1318 kctl->put = snd_ctl_elem_user_put;
1319 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE)
1320 kctl->tlv.c = snd_ctl_elem_user_tlv;
1321
1322 /* This function manage to free the instance on failure. */
1323 err = snd_ctl_add(card, kctl);
1324 if (err < 0)
1325 return err;
1326 offset = snd_ctl_get_ioff(kctl, &info->id);
1327 snd_ctl_build_ioff(&info->id, kctl, offset);
1328 /*
1329 * Here we cannot fill any field for the number of elements added by
1330 * this operation because there're no specific fields. The usage of
1331 * 'owner' field for this purpose may cause any bugs to userspace
1332 * applications because the field originally means PID of a process
1333 * which locks the element.
1334 */
1335
1336 down_write(&card->controls_rwsem);
1337 card->user_ctl_count++;
1338 up_write(&card->controls_rwsem);
1339
1340 return 0;
1341}
1342
1343static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1344 struct snd_ctl_elem_info __user *_info, int replace)
1345{
1346 struct snd_ctl_elem_info info;
1347 int err;
1348
1349 if (copy_from_user(&info, _info, sizeof(info)))
1350 return -EFAULT;
1351 err = snd_ctl_elem_add(file, &info, replace);
1352 if (err < 0)
1353 return err;
1354 if (copy_to_user(_info, &info, sizeof(info))) {
1355 snd_ctl_remove_user_ctl(file, &info.id);
1356 return -EFAULT;
1357 }
1358
1359 return 0;
1360}
1361
1362static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1363 struct snd_ctl_elem_id __user *_id)
1364{
1365 struct snd_ctl_elem_id id;
1366
1367 if (copy_from_user(&id, _id, sizeof(id)))
1368 return -EFAULT;
1369 return snd_ctl_remove_user_ctl(file, &id);
1370}
1371
1372static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1373{
1374 int subscribe;
1375 if (get_user(subscribe, ptr))
1376 return -EFAULT;
1377 if (subscribe < 0) {
1378 subscribe = file->subscribed;
1379 if (put_user(subscribe, ptr))
1380 return -EFAULT;
1381 return 0;
1382 }
1383 if (subscribe) {
1384 file->subscribed = 1;
1385 return 0;
1386 } else if (file->subscribed) {
1387 snd_ctl_empty_read_queue(file);
1388 file->subscribed = 0;
1389 }
1390 return 0;
1391}
1392
1393static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1394 struct snd_ctl_tlv __user *_tlv,
1395 int op_flag)
1396{
1397 struct snd_card *card = file->card;
1398 struct snd_ctl_tlv tlv;
1399 struct snd_kcontrol *kctl;
1400 struct snd_kcontrol_volatile *vd;
1401 unsigned int len;
1402 int err = 0;
1403
1404 if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1405 return -EFAULT;
1406 if (tlv.length < sizeof(unsigned int) * 2)
1407 return -EINVAL;
1408 if (!tlv.numid)
1409 return -EINVAL;
1410 down_read(&card->controls_rwsem);
1411 kctl = snd_ctl_find_numid(card, tlv.numid);
1412 if (kctl == NULL) {
1413 err = -ENOENT;
1414 goto __kctl_end;
1415 }
1416 if (kctl->tlv.p == NULL) {
1417 err = -ENXIO;
1418 goto __kctl_end;
1419 }
1420 vd = &kctl->vd[tlv.numid - kctl->id.numid];
1421 if ((op_flag == SNDRV_CTL_TLV_OP_READ &&
1422 (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1423 (op_flag == SNDRV_CTL_TLV_OP_WRITE &&
1424 (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1425 (op_flag == SNDRV_CTL_TLV_OP_CMD &&
1426 (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1427 err = -ENXIO;
1428 goto __kctl_end;
1429 }
1430 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1431 if (vd->owner != NULL && vd->owner != file) {
1432 err = -EPERM;
1433 goto __kctl_end;
1434 }
1435 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1436 if (err > 0) {
1437 struct snd_ctl_elem_id id = kctl->id;
1438 up_read(&card->controls_rwsem);
1439 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &id);
1440 return 0;
1441 }
1442 } else {
1443 if (op_flag != SNDRV_CTL_TLV_OP_READ) {
1444 err = -ENXIO;
1445 goto __kctl_end;
1446 }
1447 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1448 if (tlv.length < len) {
1449 err = -ENOMEM;
1450 goto __kctl_end;
1451 }
1452 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1453 err = -EFAULT;
1454 }
1455 __kctl_end:
1456 up_read(&card->controls_rwsem);
1457 return err;
1458}
1459
1460static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1461{
1462 struct snd_ctl_file *ctl;
1463 struct snd_card *card;
1464 struct snd_kctl_ioctl *p;
1465 void __user *argp = (void __user *)arg;
1466 int __user *ip = argp;
1467 int err;
1468
1469 ctl = file->private_data;
1470 card = ctl->card;
1471 if (snd_BUG_ON(!card))
1472 return -ENXIO;
1473 switch (cmd) {
1474 case SNDRV_CTL_IOCTL_PVERSION:
1475 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1476 case SNDRV_CTL_IOCTL_CARD_INFO:
1477 return snd_ctl_card_info(card, ctl, cmd, argp);
1478 case SNDRV_CTL_IOCTL_ELEM_LIST:
1479 return snd_ctl_elem_list(card, argp);
1480 case SNDRV_CTL_IOCTL_ELEM_INFO:
1481 return snd_ctl_elem_info_user(ctl, argp);
1482 case SNDRV_CTL_IOCTL_ELEM_READ:
1483 return snd_ctl_elem_read_user(card, argp);
1484 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1485 return snd_ctl_elem_write_user(ctl, argp);
1486 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1487 return snd_ctl_elem_lock(ctl, argp);
1488 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1489 return snd_ctl_elem_unlock(ctl, argp);
1490 case SNDRV_CTL_IOCTL_ELEM_ADD:
1491 return snd_ctl_elem_add_user(ctl, argp, 0);
1492 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1493 return snd_ctl_elem_add_user(ctl, argp, 1);
1494 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1495 return snd_ctl_elem_remove(ctl, argp);
1496 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1497 return snd_ctl_subscribe_events(ctl, ip);
1498 case SNDRV_CTL_IOCTL_TLV_READ:
1499 return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
1500 case SNDRV_CTL_IOCTL_TLV_WRITE:
1501 return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
1502 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1503 return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
1504 case SNDRV_CTL_IOCTL_POWER:
1505 return -ENOPROTOOPT;
1506 case SNDRV_CTL_IOCTL_POWER_STATE:
1507#ifdef CONFIG_PM
1508 return put_user(card->power_state, ip) ? -EFAULT : 0;
1509#else
1510 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1511#endif
1512 }
1513 down_read(&snd_ioctl_rwsem);
1514 list_for_each_entry(p, &snd_control_ioctls, list) {
1515 err = p->fioctl(card, ctl, cmd, arg);
1516 if (err != -ENOIOCTLCMD) {
1517 up_read(&snd_ioctl_rwsem);
1518 return err;
1519 }
1520 }
1521 up_read(&snd_ioctl_rwsem);
1522 dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
1523 return -ENOTTY;
1524}
1525
1526static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1527 size_t count, loff_t * offset)
1528{
1529 struct snd_ctl_file *ctl;
1530 int err = 0;
1531 ssize_t result = 0;
1532
1533 ctl = file->private_data;
1534 if (snd_BUG_ON(!ctl || !ctl->card))
1535 return -ENXIO;
1536 if (!ctl->subscribed)
1537 return -EBADFD;
1538 if (count < sizeof(struct snd_ctl_event))
1539 return -EINVAL;
1540 spin_lock_irq(&ctl->read_lock);
1541 while (count >= sizeof(struct snd_ctl_event)) {
1542 struct snd_ctl_event ev;
1543 struct snd_kctl_event *kev;
1544 while (list_empty(&ctl->events)) {
1545 wait_queue_t wait;
1546 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1547 err = -EAGAIN;
1548 goto __end_lock;
1549 }
1550 init_waitqueue_entry(&wait, current);
1551 add_wait_queue(&ctl->change_sleep, &wait);
1552 set_current_state(TASK_INTERRUPTIBLE);
1553 spin_unlock_irq(&ctl->read_lock);
1554 schedule();
1555 remove_wait_queue(&ctl->change_sleep, &wait);
1556 if (ctl->card->shutdown)
1557 return -ENODEV;
1558 if (signal_pending(current))
1559 return -ERESTARTSYS;
1560 spin_lock_irq(&ctl->read_lock);
1561 }
1562 kev = snd_kctl_event(ctl->events.next);
1563 ev.type = SNDRV_CTL_EVENT_ELEM;
1564 ev.data.elem.mask = kev->mask;
1565 ev.data.elem.id = kev->id;
1566 list_del(&kev->list);
1567 spin_unlock_irq(&ctl->read_lock);
1568 kfree(kev);
1569 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1570 err = -EFAULT;
1571 goto __end;
1572 }
1573 spin_lock_irq(&ctl->read_lock);
1574 buffer += sizeof(struct snd_ctl_event);
1575 count -= sizeof(struct snd_ctl_event);
1576 result += sizeof(struct snd_ctl_event);
1577 }
1578 __end_lock:
1579 spin_unlock_irq(&ctl->read_lock);
1580 __end:
1581 return result > 0 ? result : err;
1582}
1583
1584static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1585{
1586 unsigned int mask;
1587 struct snd_ctl_file *ctl;
1588
1589 ctl = file->private_data;
1590 if (!ctl->subscribed)
1591 return 0;
1592 poll_wait(file, &ctl->change_sleep, wait);
1593
1594 mask = 0;
1595 if (!list_empty(&ctl->events))
1596 mask |= POLLIN | POLLRDNORM;
1597
1598 return mask;
1599}
1600
1601/*
1602 * register the device-specific control-ioctls.
1603 * called from each device manager like pcm.c, hwdep.c, etc.
1604 */
1605static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1606{
1607 struct snd_kctl_ioctl *pn;
1608
1609 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1610 if (pn == NULL)
1611 return -ENOMEM;
1612 pn->fioctl = fcn;
1613 down_write(&snd_ioctl_rwsem);
1614 list_add_tail(&pn->list, lists);
1615 up_write(&snd_ioctl_rwsem);
1616 return 0;
1617}
1618
1619/**
1620 * snd_ctl_register_ioctl - register the device-specific control-ioctls
1621 * @fcn: ioctl callback function
1622 *
1623 * called from each device manager like pcm.c, hwdep.c, etc.
1624 */
1625int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1626{
1627 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1628}
1629EXPORT_SYMBOL(snd_ctl_register_ioctl);
1630
1631#ifdef CONFIG_COMPAT
1632/**
1633 * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
1634 * control-ioctls
1635 * @fcn: ioctl callback function
1636 */
1637int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1638{
1639 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1640}
1641EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1642#endif
1643
1644/*
1645 * de-register the device-specific control-ioctls.
1646 */
1647static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1648 struct list_head *lists)
1649{
1650 struct snd_kctl_ioctl *p;
1651
1652 if (snd_BUG_ON(!fcn))
1653 return -EINVAL;
1654 down_write(&snd_ioctl_rwsem);
1655 list_for_each_entry(p, lists, list) {
1656 if (p->fioctl == fcn) {
1657 list_del(&p->list);
1658 up_write(&snd_ioctl_rwsem);
1659 kfree(p);
1660 return 0;
1661 }
1662 }
1663 up_write(&snd_ioctl_rwsem);
1664 snd_BUG();
1665 return -EINVAL;
1666}
1667
1668/**
1669 * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
1670 * @fcn: ioctl callback function to unregister
1671 */
1672int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1673{
1674 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1675}
1676EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1677
1678#ifdef CONFIG_COMPAT
1679/**
1680 * snd_ctl_unregister_ioctl - de-register the device-specific compat 32bit
1681 * control-ioctls
1682 * @fcn: ioctl callback function to unregister
1683 */
1684int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1685{
1686 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1687}
1688EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1689#endif
1690
1691static int snd_ctl_fasync(int fd, struct file * file, int on)
1692{
1693 struct snd_ctl_file *ctl;
1694
1695 ctl = file->private_data;
1696 return fasync_helper(fd, file, on, &ctl->fasync);
1697}
1698
1699/* return the preferred subdevice number if already assigned;
1700 * otherwise return -1
1701 */
1702int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
1703{
1704 struct snd_ctl_file *kctl;
1705 int subdevice = -1;
1706
1707 read_lock(&card->ctl_files_rwlock);
1708 list_for_each_entry(kctl, &card->ctl_files, list) {
1709 if (kctl->pid == task_pid(current)) {
1710 subdevice = kctl->preferred_subdevice[type];
1711 if (subdevice != -1)
1712 break;
1713 }
1714 }
1715 read_unlock(&card->ctl_files_rwlock);
1716 return subdevice;
1717}
1718EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);
1719
1720/*
1721 * ioctl32 compat
1722 */
1723#ifdef CONFIG_COMPAT
1724#include "control_compat.c"
1725#else
1726#define snd_ctl_ioctl_compat NULL
1727#endif
1728
1729/*
1730 * INIT PART
1731 */
1732
1733static const struct file_operations snd_ctl_f_ops =
1734{
1735 .owner = THIS_MODULE,
1736 .read = snd_ctl_read,
1737 .open = snd_ctl_open,
1738 .release = snd_ctl_release,
1739 .llseek = no_llseek,
1740 .poll = snd_ctl_poll,
1741 .unlocked_ioctl = snd_ctl_ioctl,
1742 .compat_ioctl = snd_ctl_ioctl_compat,
1743 .fasync = snd_ctl_fasync,
1744};
1745
1746/*
1747 * registration of the control device
1748 */
1749static int snd_ctl_dev_register(struct snd_device *device)
1750{
1751 struct snd_card *card = device->device_data;
1752
1753 return snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1754 &snd_ctl_f_ops, card, &card->ctl_dev);
1755}
1756
1757/*
1758 * disconnection of the control device
1759 */
1760static int snd_ctl_dev_disconnect(struct snd_device *device)
1761{
1762 struct snd_card *card = device->device_data;
1763 struct snd_ctl_file *ctl;
1764
1765 read_lock(&card->ctl_files_rwlock);
1766 list_for_each_entry(ctl, &card->ctl_files, list) {
1767 wake_up(&ctl->change_sleep);
1768 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1769 }
1770 read_unlock(&card->ctl_files_rwlock);
1771
1772 return snd_unregister_device(&card->ctl_dev);
1773}
1774
1775/*
1776 * free all controls
1777 */
1778static int snd_ctl_dev_free(struct snd_device *device)
1779{
1780 struct snd_card *card = device->device_data;
1781 struct snd_kcontrol *control;
1782
1783 down_write(&card->controls_rwsem);
1784 while (!list_empty(&card->controls)) {
1785 control = snd_kcontrol(card->controls.next);
1786 snd_ctl_remove(card, control);
1787 }
1788 up_write(&card->controls_rwsem);
1789 put_device(&card->ctl_dev);
1790 return 0;
1791}
1792
1793/*
1794 * create control core:
1795 * called from init.c
1796 */
1797int snd_ctl_create(struct snd_card *card)
1798{
1799 static struct snd_device_ops ops = {
1800 .dev_free = snd_ctl_dev_free,
1801 .dev_register = snd_ctl_dev_register,
1802 .dev_disconnect = snd_ctl_dev_disconnect,
1803 };
1804 int err;
1805
1806 if (snd_BUG_ON(!card))
1807 return -ENXIO;
1808 if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS))
1809 return -ENXIO;
1810
1811 snd_device_initialize(&card->ctl_dev, card);
1812 dev_set_name(&card->ctl_dev, "controlC%d", card->number);
1813
1814 err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1815 if (err < 0)
1816 put_device(&card->ctl_dev);
1817 return err;
1818}
1819
1820/*
1821 * Frequently used control callbacks/helpers
1822 */
1823
1824/**
1825 * snd_ctl_boolean_mono_info - Helper function for a standard boolean info
1826 * callback with a mono channel
1827 * @kcontrol: the kcontrol instance
1828 * @uinfo: info to store
1829 *
1830 * This is a function that can be used as info callback for a standard
1831 * boolean control with a single mono channel.
1832 */
1833int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1834 struct snd_ctl_elem_info *uinfo)
1835{
1836 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1837 uinfo->count = 1;
1838 uinfo->value.integer.min = 0;
1839 uinfo->value.integer.max = 1;
1840 return 0;
1841}
1842EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1843
1844/**
1845 * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info
1846 * callback with stereo two channels
1847 * @kcontrol: the kcontrol instance
1848 * @uinfo: info to store
1849 *
1850 * This is a function that can be used as info callback for a standard
1851 * boolean control with stereo two channels.
1852 */
1853int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1854 struct snd_ctl_elem_info *uinfo)
1855{
1856 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1857 uinfo->count = 2;
1858 uinfo->value.integer.min = 0;
1859 uinfo->value.integer.max = 1;
1860 return 0;
1861}
1862EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1863
1864/**
1865 * snd_ctl_enum_info - fills the info structure for an enumerated control
1866 * @info: the structure to be filled
1867 * @channels: the number of the control's channels; often one
1868 * @items: the number of control values; also the size of @names
1869 * @names: an array containing the names of all control values
1870 *
1871 * Sets all required fields in @info to their appropriate values.
1872 * If the control's accessibility is not the default (readable and writable),
1873 * the caller has to fill @info->access.
1874 *
1875 * Return: Zero.
1876 */
1877int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1878 unsigned int items, const char *const names[])
1879{
1880 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1881 info->count = channels;
1882 info->value.enumerated.items = items;
1883 if (!items)
1884 return 0;
1885 if (info->value.enumerated.item >= items)
1886 info->value.enumerated.item = items - 1;
1887 WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
1888 "ALSA: too long item name '%s'\n",
1889 names[info->value.enumerated.item]);
1890 strlcpy(info->value.enumerated.name,
1891 names[info->value.enumerated.item],
1892 sizeof(info->value.enumerated.name));
1893 return 0;
1894}
1895EXPORT_SYMBOL(snd_ctl_enum_info);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Routines for driver control interface
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7#include <linux/threads.h>
8#include <linux/interrupt.h>
9#include <linux/module.h>
10#include <linux/moduleparam.h>
11#include <linux/slab.h>
12#include <linux/vmalloc.h>
13#include <linux/time.h>
14#include <linux/mm.h>
15#include <linux/math64.h>
16#include <linux/sched/signal.h>
17#include <sound/core.h>
18#include <sound/minors.h>
19#include <sound/info.h>
20#include <sound/control.h>
21
22// Max allocation size for user controls.
23static int max_user_ctl_alloc_size = 8 * 1024 * 1024;
24module_param_named(max_user_ctl_alloc_size, max_user_ctl_alloc_size, int, 0444);
25MODULE_PARM_DESC(max_user_ctl_alloc_size, "Max allocation size for user controls");
26
27#define MAX_CONTROL_COUNT 1028
28
29struct snd_kctl_ioctl {
30 struct list_head list; /* list of all ioctls */
31 snd_kctl_ioctl_func_t fioctl;
32};
33
34static DECLARE_RWSEM(snd_ioctl_rwsem);
35static DECLARE_RWSEM(snd_ctl_layer_rwsem);
36static LIST_HEAD(snd_control_ioctls);
37#ifdef CONFIG_COMPAT
38static LIST_HEAD(snd_control_compat_ioctls);
39#endif
40static struct snd_ctl_layer_ops *snd_ctl_layer;
41
42static int snd_ctl_remove_locked(struct snd_card *card,
43 struct snd_kcontrol *kcontrol);
44
45static int snd_ctl_open(struct inode *inode, struct file *file)
46{
47 unsigned long flags;
48 struct snd_card *card;
49 struct snd_ctl_file *ctl;
50 int i, err;
51
52 err = stream_open(inode, file);
53 if (err < 0)
54 return err;
55
56 card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
57 if (!card) {
58 err = -ENODEV;
59 goto __error1;
60 }
61 err = snd_card_file_add(card, file);
62 if (err < 0) {
63 err = -ENODEV;
64 goto __error1;
65 }
66 if (!try_module_get(card->module)) {
67 err = -EFAULT;
68 goto __error2;
69 }
70 ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
71 if (ctl == NULL) {
72 err = -ENOMEM;
73 goto __error;
74 }
75 INIT_LIST_HEAD(&ctl->events);
76 init_waitqueue_head(&ctl->change_sleep);
77 spin_lock_init(&ctl->read_lock);
78 ctl->card = card;
79 for (i = 0; i < SND_CTL_SUBDEV_ITEMS; i++)
80 ctl->preferred_subdevice[i] = -1;
81 ctl->pid = get_pid(task_pid(current));
82 file->private_data = ctl;
83 write_lock_irqsave(&card->ctl_files_rwlock, flags);
84 list_add_tail(&ctl->list, &card->ctl_files);
85 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
86 snd_card_unref(card);
87 return 0;
88
89 __error:
90 module_put(card->module);
91 __error2:
92 snd_card_file_remove(card, file);
93 __error1:
94 if (card)
95 snd_card_unref(card);
96 return err;
97}
98
99static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
100{
101 unsigned long flags;
102 struct snd_kctl_event *cread;
103
104 spin_lock_irqsave(&ctl->read_lock, flags);
105 while (!list_empty(&ctl->events)) {
106 cread = snd_kctl_event(ctl->events.next);
107 list_del(&cread->list);
108 kfree(cread);
109 }
110 spin_unlock_irqrestore(&ctl->read_lock, flags);
111}
112
113static int snd_ctl_release(struct inode *inode, struct file *file)
114{
115 unsigned long flags;
116 struct snd_card *card;
117 struct snd_ctl_file *ctl;
118 struct snd_kcontrol *control;
119 unsigned int idx;
120
121 ctl = file->private_data;
122 file->private_data = NULL;
123 card = ctl->card;
124 write_lock_irqsave(&card->ctl_files_rwlock, flags);
125 list_del(&ctl->list);
126 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
127 down_write(&card->controls_rwsem);
128 list_for_each_entry(control, &card->controls, list)
129 for (idx = 0; idx < control->count; idx++)
130 if (control->vd[idx].owner == ctl)
131 control->vd[idx].owner = NULL;
132 up_write(&card->controls_rwsem);
133 snd_fasync_free(ctl->fasync);
134 snd_ctl_empty_read_queue(ctl);
135 put_pid(ctl->pid);
136 kfree(ctl);
137 module_put(card->module);
138 snd_card_file_remove(card, file);
139 return 0;
140}
141
142/**
143 * snd_ctl_notify - Send notification to user-space for a control change
144 * @card: the card to send notification
145 * @mask: the event mask, SNDRV_CTL_EVENT_*
146 * @id: the ctl element id to send notification
147 *
148 * This function adds an event record with the given id and mask, appends
149 * to the list and wakes up the user-space for notification. This can be
150 * called in the atomic context.
151 */
152void snd_ctl_notify(struct snd_card *card, unsigned int mask,
153 struct snd_ctl_elem_id *id)
154{
155 unsigned long flags;
156 struct snd_ctl_file *ctl;
157 struct snd_kctl_event *ev;
158
159 if (snd_BUG_ON(!card || !id))
160 return;
161 if (card->shutdown)
162 return;
163 read_lock_irqsave(&card->ctl_files_rwlock, flags);
164#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
165 card->mixer_oss_change_count++;
166#endif
167 list_for_each_entry(ctl, &card->ctl_files, list) {
168 if (!ctl->subscribed)
169 continue;
170 spin_lock(&ctl->read_lock);
171 list_for_each_entry(ev, &ctl->events, list) {
172 if (ev->id.numid == id->numid) {
173 ev->mask |= mask;
174 goto _found;
175 }
176 }
177 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
178 if (ev) {
179 ev->id = *id;
180 ev->mask = mask;
181 list_add_tail(&ev->list, &ctl->events);
182 } else {
183 dev_err(card->dev, "No memory available to allocate event\n");
184 }
185 _found:
186 wake_up(&ctl->change_sleep);
187 spin_unlock(&ctl->read_lock);
188 snd_kill_fasync(ctl->fasync, SIGIO, POLL_IN);
189 }
190 read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
191}
192EXPORT_SYMBOL(snd_ctl_notify);
193
194/**
195 * snd_ctl_notify_one - Send notification to user-space for a control change
196 * @card: the card to send notification
197 * @mask: the event mask, SNDRV_CTL_EVENT_*
198 * @kctl: the pointer with the control instance
199 * @ioff: the additional offset to the control index
200 *
201 * This function calls snd_ctl_notify() and does additional jobs
202 * like LED state changes.
203 */
204void snd_ctl_notify_one(struct snd_card *card, unsigned int mask,
205 struct snd_kcontrol *kctl, unsigned int ioff)
206{
207 struct snd_ctl_elem_id id = kctl->id;
208 struct snd_ctl_layer_ops *lops;
209
210 id.index += ioff;
211 id.numid += ioff;
212 snd_ctl_notify(card, mask, &id);
213 down_read(&snd_ctl_layer_rwsem);
214 for (lops = snd_ctl_layer; lops; lops = lops->next)
215 lops->lnotify(card, mask, kctl, ioff);
216 up_read(&snd_ctl_layer_rwsem);
217}
218EXPORT_SYMBOL(snd_ctl_notify_one);
219
220/**
221 * snd_ctl_new - create a new control instance with some elements
222 * @kctl: the pointer to store new control instance
223 * @count: the number of elements in this control
224 * @access: the default access flags for elements in this control
225 * @file: given when locking these elements
226 *
227 * Allocates a memory object for a new control instance. The instance has
228 * elements as many as the given number (@count). Each element has given
229 * access permissions (@access). Each element is locked when @file is given.
230 *
231 * Return: 0 on success, error code on failure
232 */
233static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count,
234 unsigned int access, struct snd_ctl_file *file)
235{
236 unsigned int idx;
237
238 if (count == 0 || count > MAX_CONTROL_COUNT)
239 return -EINVAL;
240
241 *kctl = kzalloc(struct_size(*kctl, vd, count), GFP_KERNEL);
242 if (!*kctl)
243 return -ENOMEM;
244
245 for (idx = 0; idx < count; idx++) {
246 (*kctl)->vd[idx].access = access;
247 (*kctl)->vd[idx].owner = file;
248 }
249 (*kctl)->count = count;
250
251 return 0;
252}
253
254/**
255 * snd_ctl_new1 - create a control instance from the template
256 * @ncontrol: the initialization record
257 * @private_data: the private data to set
258 *
259 * Allocates a new struct snd_kcontrol instance and initialize from the given
260 * template. When the access field of ncontrol is 0, it's assumed as
261 * READWRITE access. When the count field is 0, it's assumes as one.
262 *
263 * Return: The pointer of the newly generated instance, or %NULL on failure.
264 */
265struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
266 void *private_data)
267{
268 struct snd_kcontrol *kctl;
269 unsigned int count;
270 unsigned int access;
271 int err;
272
273 if (snd_BUG_ON(!ncontrol || !ncontrol->info))
274 return NULL;
275
276 count = ncontrol->count;
277 if (count == 0)
278 count = 1;
279
280 access = ncontrol->access;
281 if (access == 0)
282 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
283 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
284 SNDRV_CTL_ELEM_ACCESS_VOLATILE |
285 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
286 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE |
287 SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND |
288 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK |
289 SNDRV_CTL_ELEM_ACCESS_LED_MASK |
290 SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK);
291
292 err = snd_ctl_new(&kctl, count, access, NULL);
293 if (err < 0)
294 return NULL;
295
296 /* The 'numid' member is decided when calling snd_ctl_add(). */
297 kctl->id.iface = ncontrol->iface;
298 kctl->id.device = ncontrol->device;
299 kctl->id.subdevice = ncontrol->subdevice;
300 if (ncontrol->name) {
301 strscpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.name));
302 if (strcmp(ncontrol->name, kctl->id.name) != 0)
303 pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
304 ncontrol->name, kctl->id.name);
305 }
306 kctl->id.index = ncontrol->index;
307
308 kctl->info = ncontrol->info;
309 kctl->get = ncontrol->get;
310 kctl->put = ncontrol->put;
311 kctl->tlv.p = ncontrol->tlv.p;
312
313 kctl->private_value = ncontrol->private_value;
314 kctl->private_data = private_data;
315
316 return kctl;
317}
318EXPORT_SYMBOL(snd_ctl_new1);
319
320/**
321 * snd_ctl_free_one - release the control instance
322 * @kcontrol: the control instance
323 *
324 * Releases the control instance created via snd_ctl_new()
325 * or snd_ctl_new1().
326 * Don't call this after the control was added to the card.
327 */
328void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
329{
330 if (kcontrol) {
331 if (kcontrol->private_free)
332 kcontrol->private_free(kcontrol);
333 kfree(kcontrol);
334 }
335}
336EXPORT_SYMBOL(snd_ctl_free_one);
337
338static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
339 unsigned int count)
340{
341 struct snd_kcontrol *kctl;
342
343 /* Make sure that the ids assigned to the control do not wrap around */
344 if (card->last_numid >= UINT_MAX - count)
345 card->last_numid = 0;
346
347 list_for_each_entry(kctl, &card->controls, list) {
348 if (kctl->id.numid < card->last_numid + 1 + count &&
349 kctl->id.numid + kctl->count > card->last_numid + 1) {
350 card->last_numid = kctl->id.numid + kctl->count - 1;
351 return true;
352 }
353 }
354 return false;
355}
356
357static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
358{
359 unsigned int iter = 100000;
360
361 while (snd_ctl_remove_numid_conflict(card, count)) {
362 if (--iter == 0) {
363 /* this situation is very unlikely */
364 dev_err(card->dev, "unable to allocate new control numid\n");
365 return -ENOMEM;
366 }
367 }
368 return 0;
369}
370
371/* check whether the given id is contained in the given kctl */
372static bool elem_id_matches(const struct snd_kcontrol *kctl,
373 const struct snd_ctl_elem_id *id)
374{
375 return kctl->id.iface == id->iface &&
376 kctl->id.device == id->device &&
377 kctl->id.subdevice == id->subdevice &&
378 !strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)) &&
379 kctl->id.index <= id->index &&
380 kctl->id.index + kctl->count > id->index;
381}
382
383#ifdef CONFIG_SND_CTL_FAST_LOOKUP
384/* Compute a hash key for the corresponding ctl id
385 * It's for the name lookup, hence the numid is excluded.
386 * The hash key is bound in LONG_MAX to be used for Xarray key.
387 */
388#define MULTIPLIER 37
389static unsigned long get_ctl_id_hash(const struct snd_ctl_elem_id *id)
390{
391 int i;
392 unsigned long h;
393
394 h = id->iface;
395 h = MULTIPLIER * h + id->device;
396 h = MULTIPLIER * h + id->subdevice;
397 for (i = 0; i < SNDRV_CTL_ELEM_ID_NAME_MAXLEN && id->name[i]; i++)
398 h = MULTIPLIER * h + id->name[i];
399 h = MULTIPLIER * h + id->index;
400 h &= LONG_MAX;
401 return h;
402}
403
404/* add hash entries to numid and ctl xarray tables */
405static void add_hash_entries(struct snd_card *card,
406 struct snd_kcontrol *kcontrol)
407{
408 struct snd_ctl_elem_id id = kcontrol->id;
409 int i;
410
411 xa_store_range(&card->ctl_numids, kcontrol->id.numid,
412 kcontrol->id.numid + kcontrol->count - 1,
413 kcontrol, GFP_KERNEL);
414
415 for (i = 0; i < kcontrol->count; i++) {
416 id.index = kcontrol->id.index + i;
417 if (xa_insert(&card->ctl_hash, get_ctl_id_hash(&id),
418 kcontrol, GFP_KERNEL)) {
419 /* skip hash for this entry, noting we had collision */
420 card->ctl_hash_collision = true;
421 dev_dbg(card->dev, "ctl_hash collision %d:%s:%d\n",
422 id.iface, id.name, id.index);
423 }
424 }
425}
426
427/* remove hash entries that have been added */
428static void remove_hash_entries(struct snd_card *card,
429 struct snd_kcontrol *kcontrol)
430{
431 struct snd_ctl_elem_id id = kcontrol->id;
432 struct snd_kcontrol *matched;
433 unsigned long h;
434 int i;
435
436 for (i = 0; i < kcontrol->count; i++) {
437 xa_erase(&card->ctl_numids, id.numid);
438 h = get_ctl_id_hash(&id);
439 matched = xa_load(&card->ctl_hash, h);
440 if (matched && (matched == kcontrol ||
441 elem_id_matches(matched, &id)))
442 xa_erase(&card->ctl_hash, h);
443 id.index++;
444 id.numid++;
445 }
446}
447#else /* CONFIG_SND_CTL_FAST_LOOKUP */
448static inline void add_hash_entries(struct snd_card *card,
449 struct snd_kcontrol *kcontrol)
450{
451}
452static inline void remove_hash_entries(struct snd_card *card,
453 struct snd_kcontrol *kcontrol)
454{
455}
456#endif /* CONFIG_SND_CTL_FAST_LOOKUP */
457
458enum snd_ctl_add_mode {
459 CTL_ADD_EXCLUSIVE, CTL_REPLACE, CTL_ADD_ON_REPLACE,
460};
461
462/* add/replace a new kcontrol object; call with card->controls_rwsem locked */
463static int __snd_ctl_add_replace(struct snd_card *card,
464 struct snd_kcontrol *kcontrol,
465 enum snd_ctl_add_mode mode)
466{
467 struct snd_ctl_elem_id id;
468 unsigned int idx;
469 struct snd_kcontrol *old;
470 int err;
471
472 lockdep_assert_held_write(&card->controls_rwsem);
473
474 id = kcontrol->id;
475 if (id.index > UINT_MAX - kcontrol->count)
476 return -EINVAL;
477
478 old = snd_ctl_find_id_locked(card, &id);
479 if (!old) {
480 if (mode == CTL_REPLACE)
481 return -EINVAL;
482 } else {
483 if (mode == CTL_ADD_EXCLUSIVE) {
484 dev_err(card->dev,
485 "control %i:%i:%i:%s:%i is already present\n",
486 id.iface, id.device, id.subdevice, id.name,
487 id.index);
488 return -EBUSY;
489 }
490
491 err = snd_ctl_remove_locked(card, old);
492 if (err < 0)
493 return err;
494 }
495
496 if (snd_ctl_find_hole(card, kcontrol->count) < 0)
497 return -ENOMEM;
498
499 list_add_tail(&kcontrol->list, &card->controls);
500 card->controls_count += kcontrol->count;
501 kcontrol->id.numid = card->last_numid + 1;
502 card->last_numid += kcontrol->count;
503
504 add_hash_entries(card, kcontrol);
505
506 for (idx = 0; idx < kcontrol->count; idx++)
507 snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_ADD, kcontrol, idx);
508
509 return 0;
510}
511
512static int snd_ctl_add_replace(struct snd_card *card,
513 struct snd_kcontrol *kcontrol,
514 enum snd_ctl_add_mode mode)
515{
516 int err = -EINVAL;
517
518 if (! kcontrol)
519 return err;
520 if (snd_BUG_ON(!card || !kcontrol->info))
521 goto error;
522
523 down_write(&card->controls_rwsem);
524 err = __snd_ctl_add_replace(card, kcontrol, mode);
525 up_write(&card->controls_rwsem);
526 if (err < 0)
527 goto error;
528 return 0;
529
530 error:
531 snd_ctl_free_one(kcontrol);
532 return err;
533}
534
535/**
536 * snd_ctl_add - add the control instance to the card
537 * @card: the card instance
538 * @kcontrol: the control instance to add
539 *
540 * Adds the control instance created via snd_ctl_new() or
541 * snd_ctl_new1() to the given card. Assigns also an unique
542 * numid used for fast search.
543 *
544 * It frees automatically the control which cannot be added.
545 *
546 * Return: Zero if successful, or a negative error code on failure.
547 *
548 */
549int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
550{
551 return snd_ctl_add_replace(card, kcontrol, CTL_ADD_EXCLUSIVE);
552}
553EXPORT_SYMBOL(snd_ctl_add);
554
555/**
556 * snd_ctl_replace - replace the control instance of the card
557 * @card: the card instance
558 * @kcontrol: the control instance to replace
559 * @add_on_replace: add the control if not already added
560 *
561 * Replaces the given control. If the given control does not exist
562 * and the add_on_replace flag is set, the control is added. If the
563 * control exists, it is destroyed first.
564 *
565 * It frees automatically the control which cannot be added or replaced.
566 *
567 * Return: Zero if successful, or a negative error code on failure.
568 */
569int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
570 bool add_on_replace)
571{
572 return snd_ctl_add_replace(card, kcontrol,
573 add_on_replace ? CTL_ADD_ON_REPLACE : CTL_REPLACE);
574}
575EXPORT_SYMBOL(snd_ctl_replace);
576
577static int __snd_ctl_remove(struct snd_card *card,
578 struct snd_kcontrol *kcontrol,
579 bool remove_hash)
580{
581 unsigned int idx;
582
583 lockdep_assert_held_write(&card->controls_rwsem);
584
585 if (snd_BUG_ON(!card || !kcontrol))
586 return -EINVAL;
587 list_del(&kcontrol->list);
588
589 if (remove_hash)
590 remove_hash_entries(card, kcontrol);
591
592 card->controls_count -= kcontrol->count;
593 for (idx = 0; idx < kcontrol->count; idx++)
594 snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_REMOVE, kcontrol, idx);
595 snd_ctl_free_one(kcontrol);
596 return 0;
597}
598
599static inline int snd_ctl_remove_locked(struct snd_card *card,
600 struct snd_kcontrol *kcontrol)
601{
602 return __snd_ctl_remove(card, kcontrol, true);
603}
604
605/**
606 * snd_ctl_remove - remove the control from the card and release it
607 * @card: the card instance
608 * @kcontrol: the control instance to remove
609 *
610 * Removes the control from the card and then releases the instance.
611 * You don't need to call snd_ctl_free_one().
612 *
613 * Return: 0 if successful, or a negative error code on failure.
614 *
615 * Note that this function takes card->controls_rwsem lock internally.
616 */
617int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
618{
619 int ret;
620
621 down_write(&card->controls_rwsem);
622 ret = snd_ctl_remove_locked(card, kcontrol);
623 up_write(&card->controls_rwsem);
624 return ret;
625}
626EXPORT_SYMBOL(snd_ctl_remove);
627
628/**
629 * snd_ctl_remove_id - remove the control of the given id and release it
630 * @card: the card instance
631 * @id: the control id to remove
632 *
633 * Finds the control instance with the given id, removes it from the
634 * card list and releases it.
635 *
636 * Return: 0 if successful, or a negative error code on failure.
637 */
638int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
639{
640 struct snd_kcontrol *kctl;
641 int ret;
642
643 down_write(&card->controls_rwsem);
644 kctl = snd_ctl_find_id_locked(card, id);
645 if (kctl == NULL) {
646 up_write(&card->controls_rwsem);
647 return -ENOENT;
648 }
649 ret = snd_ctl_remove_locked(card, kctl);
650 up_write(&card->controls_rwsem);
651 return ret;
652}
653EXPORT_SYMBOL(snd_ctl_remove_id);
654
655/**
656 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
657 * @file: active control handle
658 * @id: the control id to remove
659 *
660 * Finds the control instance with the given id, removes it from the
661 * card list and releases it.
662 *
663 * Return: 0 if successful, or a negative error code on failure.
664 */
665static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
666 struct snd_ctl_elem_id *id)
667{
668 struct snd_card *card = file->card;
669 struct snd_kcontrol *kctl;
670 int idx, ret;
671
672 down_write(&card->controls_rwsem);
673 kctl = snd_ctl_find_id_locked(card, id);
674 if (kctl == NULL) {
675 ret = -ENOENT;
676 goto error;
677 }
678 if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
679 ret = -EINVAL;
680 goto error;
681 }
682 for (idx = 0; idx < kctl->count; idx++)
683 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
684 ret = -EBUSY;
685 goto error;
686 }
687 ret = snd_ctl_remove_locked(card, kctl);
688error:
689 up_write(&card->controls_rwsem);
690 return ret;
691}
692
693/**
694 * snd_ctl_activate_id - activate/inactivate the control of the given id
695 * @card: the card instance
696 * @id: the control id to activate/inactivate
697 * @active: non-zero to activate
698 *
699 * Finds the control instance with the given id, and activate or
700 * inactivate the control together with notification, if changed.
701 * The given ID data is filled with full information.
702 *
703 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
704 */
705int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
706 int active)
707{
708 struct snd_kcontrol *kctl;
709 struct snd_kcontrol_volatile *vd;
710 unsigned int index_offset;
711 int ret;
712
713 down_write(&card->controls_rwsem);
714 kctl = snd_ctl_find_id_locked(card, id);
715 if (kctl == NULL) {
716 ret = -ENOENT;
717 goto unlock;
718 }
719 index_offset = snd_ctl_get_ioff(kctl, id);
720 vd = &kctl->vd[index_offset];
721 ret = 0;
722 if (active) {
723 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
724 goto unlock;
725 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
726 } else {
727 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
728 goto unlock;
729 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
730 }
731 snd_ctl_build_ioff(id, kctl, index_offset);
732 downgrade_write(&card->controls_rwsem);
733 snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_INFO, kctl, index_offset);
734 up_read(&card->controls_rwsem);
735 return 1;
736
737 unlock:
738 up_write(&card->controls_rwsem);
739 return ret;
740}
741EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
742
743/**
744 * snd_ctl_rename_id - replace the id of a control on the card
745 * @card: the card instance
746 * @src_id: the old id
747 * @dst_id: the new id
748 *
749 * Finds the control with the old id from the card, and replaces the
750 * id with the new one.
751 *
752 * The function tries to keep the already assigned numid while replacing
753 * the rest.
754 *
755 * Note that this function should be used only in the card initialization
756 * phase. Calling after the card instantiation may cause issues with
757 * user-space expecting persistent numids.
758 *
759 * Return: Zero if successful, or a negative error code on failure.
760 */
761int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
762 struct snd_ctl_elem_id *dst_id)
763{
764 struct snd_kcontrol *kctl;
765 int saved_numid;
766
767 down_write(&card->controls_rwsem);
768 kctl = snd_ctl_find_id_locked(card, src_id);
769 if (kctl == NULL) {
770 up_write(&card->controls_rwsem);
771 return -ENOENT;
772 }
773 saved_numid = kctl->id.numid;
774 remove_hash_entries(card, kctl);
775 kctl->id = *dst_id;
776 kctl->id.numid = saved_numid;
777 add_hash_entries(card, kctl);
778 up_write(&card->controls_rwsem);
779 return 0;
780}
781EXPORT_SYMBOL(snd_ctl_rename_id);
782
783/**
784 * snd_ctl_rename - rename the control on the card
785 * @card: the card instance
786 * @kctl: the control to rename
787 * @name: the new name
788 *
789 * Renames the specified control on the card to the new name.
790 *
791 * Note that this function takes card->controls_rwsem lock internally.
792 */
793void snd_ctl_rename(struct snd_card *card, struct snd_kcontrol *kctl,
794 const char *name)
795{
796 down_write(&card->controls_rwsem);
797 remove_hash_entries(card, kctl);
798
799 if (strscpy(kctl->id.name, name, sizeof(kctl->id.name)) < 0)
800 pr_warn("ALSA: Renamed control new name '%s' truncated to '%s'\n",
801 name, kctl->id.name);
802
803 add_hash_entries(card, kctl);
804 up_write(&card->controls_rwsem);
805}
806EXPORT_SYMBOL(snd_ctl_rename);
807
808#ifndef CONFIG_SND_CTL_FAST_LOOKUP
809static struct snd_kcontrol *
810snd_ctl_find_numid_slow(struct snd_card *card, unsigned int numid)
811{
812 struct snd_kcontrol *kctl;
813
814 list_for_each_entry(kctl, &card->controls, list) {
815 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
816 return kctl;
817 }
818 return NULL;
819}
820#endif /* !CONFIG_SND_CTL_FAST_LOOKUP */
821
822/**
823 * snd_ctl_find_numid_locked - find the control instance with the given number-id
824 * @card: the card instance
825 * @numid: the number-id to search
826 *
827 * Finds the control instance with the given number-id from the card.
828 *
829 * The caller must down card->controls_rwsem before calling this function
830 * (if the race condition can happen).
831 *
832 * Return: The pointer of the instance if found, or %NULL if not.
833 */
834struct snd_kcontrol *
835snd_ctl_find_numid_locked(struct snd_card *card, unsigned int numid)
836{
837 if (snd_BUG_ON(!card || !numid))
838 return NULL;
839 lockdep_assert_held(&card->controls_rwsem);
840#ifdef CONFIG_SND_CTL_FAST_LOOKUP
841 return xa_load(&card->ctl_numids, numid);
842#else
843 return snd_ctl_find_numid_slow(card, numid);
844#endif
845}
846EXPORT_SYMBOL(snd_ctl_find_numid_locked);
847
848/**
849 * snd_ctl_find_numid - find the control instance with the given number-id
850 * @card: the card instance
851 * @numid: the number-id to search
852 *
853 * Finds the control instance with the given number-id from the card.
854 *
855 * Return: The pointer of the instance if found, or %NULL if not.
856 *
857 * Note that this function takes card->controls_rwsem lock internally.
858 */
859struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card,
860 unsigned int numid)
861{
862 struct snd_kcontrol *kctl;
863
864 down_read(&card->controls_rwsem);
865 kctl = snd_ctl_find_numid_locked(card, numid);
866 up_read(&card->controls_rwsem);
867 return kctl;
868}
869EXPORT_SYMBOL(snd_ctl_find_numid);
870
871/**
872 * snd_ctl_find_id_locked - find the control instance with the given id
873 * @card: the card instance
874 * @id: the id to search
875 *
876 * Finds the control instance with the given id from the card.
877 *
878 * The caller must down card->controls_rwsem before calling this function
879 * (if the race condition can happen).
880 *
881 * Return: The pointer of the instance if found, or %NULL if not.
882 */
883struct snd_kcontrol *snd_ctl_find_id_locked(struct snd_card *card,
884 const struct snd_ctl_elem_id *id)
885{
886 struct snd_kcontrol *kctl;
887
888 if (snd_BUG_ON(!card || !id))
889 return NULL;
890 lockdep_assert_held(&card->controls_rwsem);
891 if (id->numid != 0)
892 return snd_ctl_find_numid_locked(card, id->numid);
893#ifdef CONFIG_SND_CTL_FAST_LOOKUP
894 kctl = xa_load(&card->ctl_hash, get_ctl_id_hash(id));
895 if (kctl && elem_id_matches(kctl, id))
896 return kctl;
897 if (!card->ctl_hash_collision)
898 return NULL; /* we can rely on only hash table */
899#endif
900 /* no matching in hash table - try all as the last resort */
901 list_for_each_entry(kctl, &card->controls, list)
902 if (elem_id_matches(kctl, id))
903 return kctl;
904
905 return NULL;
906}
907EXPORT_SYMBOL(snd_ctl_find_id_locked);
908
909/**
910 * snd_ctl_find_id - find the control instance with the given id
911 * @card: the card instance
912 * @id: the id to search
913 *
914 * Finds the control instance with the given id from the card.
915 *
916 * Return: The pointer of the instance if found, or %NULL if not.
917 *
918 * Note that this function takes card->controls_rwsem lock internally.
919 */
920struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
921 const struct snd_ctl_elem_id *id)
922{
923 struct snd_kcontrol *kctl;
924
925 down_read(&card->controls_rwsem);
926 kctl = snd_ctl_find_id_locked(card, id);
927 up_read(&card->controls_rwsem);
928 return kctl;
929}
930EXPORT_SYMBOL(snd_ctl_find_id);
931
932static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
933 unsigned int cmd, void __user *arg)
934{
935 struct snd_ctl_card_info *info;
936
937 info = kzalloc(sizeof(*info), GFP_KERNEL);
938 if (! info)
939 return -ENOMEM;
940 down_read(&snd_ioctl_rwsem);
941 info->card = card->number;
942 strscpy(info->id, card->id, sizeof(info->id));
943 strscpy(info->driver, card->driver, sizeof(info->driver));
944 strscpy(info->name, card->shortname, sizeof(info->name));
945 strscpy(info->longname, card->longname, sizeof(info->longname));
946 strscpy(info->mixername, card->mixername, sizeof(info->mixername));
947 strscpy(info->components, card->components, sizeof(info->components));
948 up_read(&snd_ioctl_rwsem);
949 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
950 kfree(info);
951 return -EFAULT;
952 }
953 kfree(info);
954 return 0;
955}
956
957static int snd_ctl_elem_list(struct snd_card *card,
958 struct snd_ctl_elem_list *list)
959{
960 struct snd_kcontrol *kctl;
961 struct snd_ctl_elem_id id;
962 unsigned int offset, space, jidx;
963 int err = 0;
964
965 offset = list->offset;
966 space = list->space;
967
968 down_read(&card->controls_rwsem);
969 list->count = card->controls_count;
970 list->used = 0;
971 if (space > 0) {
972 list_for_each_entry(kctl, &card->controls, list) {
973 if (offset >= kctl->count) {
974 offset -= kctl->count;
975 continue;
976 }
977 for (jidx = offset; jidx < kctl->count; jidx++) {
978 snd_ctl_build_ioff(&id, kctl, jidx);
979 if (copy_to_user(list->pids + list->used, &id,
980 sizeof(id))) {
981 err = -EFAULT;
982 goto out;
983 }
984 list->used++;
985 if (!--space)
986 goto out;
987 }
988 offset = 0;
989 }
990 }
991 out:
992 up_read(&card->controls_rwsem);
993 return err;
994}
995
996static int snd_ctl_elem_list_user(struct snd_card *card,
997 struct snd_ctl_elem_list __user *_list)
998{
999 struct snd_ctl_elem_list list;
1000 int err;
1001
1002 if (copy_from_user(&list, _list, sizeof(list)))
1003 return -EFAULT;
1004 err = snd_ctl_elem_list(card, &list);
1005 if (err)
1006 return err;
1007 if (copy_to_user(_list, &list, sizeof(list)))
1008 return -EFAULT;
1009
1010 return 0;
1011}
1012
1013/* Check whether the given kctl info is valid */
1014static int snd_ctl_check_elem_info(struct snd_card *card,
1015 const struct snd_ctl_elem_info *info)
1016{
1017 static const unsigned int max_value_counts[] = {
1018 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = 128,
1019 [SNDRV_CTL_ELEM_TYPE_INTEGER] = 128,
1020 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = 128,
1021 [SNDRV_CTL_ELEM_TYPE_BYTES] = 512,
1022 [SNDRV_CTL_ELEM_TYPE_IEC958] = 1,
1023 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64,
1024 };
1025
1026 if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
1027 info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64) {
1028 if (card)
1029 dev_err(card->dev,
1030 "control %i:%i:%i:%s:%i: invalid type %d\n",
1031 info->id.iface, info->id.device,
1032 info->id.subdevice, info->id.name,
1033 info->id.index, info->type);
1034 return -EINVAL;
1035 }
1036 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED &&
1037 info->value.enumerated.items == 0) {
1038 if (card)
1039 dev_err(card->dev,
1040 "control %i:%i:%i:%s:%i: zero enum items\n",
1041 info->id.iface, info->id.device,
1042 info->id.subdevice, info->id.name,
1043 info->id.index);
1044 return -EINVAL;
1045 }
1046 if (info->count > max_value_counts[info->type]) {
1047 if (card)
1048 dev_err(card->dev,
1049 "control %i:%i:%i:%s:%i: invalid count %d\n",
1050 info->id.iface, info->id.device,
1051 info->id.subdevice, info->id.name,
1052 info->id.index, info->count);
1053 return -EINVAL;
1054 }
1055
1056 return 0;
1057}
1058
1059/* The capacity of struct snd_ctl_elem_value.value.*/
1060static const unsigned int value_sizes[] = {
1061 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = sizeof(long),
1062 [SNDRV_CTL_ELEM_TYPE_INTEGER] = sizeof(long),
1063 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = sizeof(unsigned int),
1064 [SNDRV_CTL_ELEM_TYPE_BYTES] = sizeof(unsigned char),
1065 [SNDRV_CTL_ELEM_TYPE_IEC958] = sizeof(struct snd_aes_iec958),
1066 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long),
1067};
1068
1069/* fill the remaining snd_ctl_elem_value data with the given pattern */
1070static void fill_remaining_elem_value(struct snd_ctl_elem_value *control,
1071 struct snd_ctl_elem_info *info,
1072 u32 pattern)
1073{
1074 size_t offset = value_sizes[info->type] * info->count;
1075
1076 offset = DIV_ROUND_UP(offset, sizeof(u32));
1077 memset32((u32 *)control->value.bytes.data + offset, pattern,
1078 sizeof(control->value) / sizeof(u32) - offset);
1079}
1080
1081/* check whether the given integer ctl value is valid */
1082static int sanity_check_int_value(struct snd_card *card,
1083 const struct snd_ctl_elem_value *control,
1084 const struct snd_ctl_elem_info *info,
1085 int i, bool print_error)
1086{
1087 long long lval, lmin, lmax, lstep;
1088 u64 rem;
1089
1090 switch (info->type) {
1091 default:
1092 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1093 lval = control->value.integer.value[i];
1094 lmin = 0;
1095 lmax = 1;
1096 lstep = 0;
1097 break;
1098 case SNDRV_CTL_ELEM_TYPE_INTEGER:
1099 lval = control->value.integer.value[i];
1100 lmin = info->value.integer.min;
1101 lmax = info->value.integer.max;
1102 lstep = info->value.integer.step;
1103 break;
1104 case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1105 lval = control->value.integer64.value[i];
1106 lmin = info->value.integer64.min;
1107 lmax = info->value.integer64.max;
1108 lstep = info->value.integer64.step;
1109 break;
1110 case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1111 lval = control->value.enumerated.item[i];
1112 lmin = 0;
1113 lmax = info->value.enumerated.items - 1;
1114 lstep = 0;
1115 break;
1116 }
1117
1118 if (lval < lmin || lval > lmax) {
1119 if (print_error)
1120 dev_err(card->dev,
1121 "control %i:%i:%i:%s:%i: value out of range %lld (%lld/%lld) at count %i\n",
1122 control->id.iface, control->id.device,
1123 control->id.subdevice, control->id.name,
1124 control->id.index, lval, lmin, lmax, i);
1125 return -EINVAL;
1126 }
1127 if (lstep) {
1128 div64_u64_rem(lval, lstep, &rem);
1129 if (rem) {
1130 if (print_error)
1131 dev_err(card->dev,
1132 "control %i:%i:%i:%s:%i: unaligned value %lld (step %lld) at count %i\n",
1133 control->id.iface, control->id.device,
1134 control->id.subdevice, control->id.name,
1135 control->id.index, lval, lstep, i);
1136 return -EINVAL;
1137 }
1138 }
1139
1140 return 0;
1141}
1142
1143/* check whether the all input values are valid for the given elem value */
1144static int sanity_check_input_values(struct snd_card *card,
1145 const struct snd_ctl_elem_value *control,
1146 const struct snd_ctl_elem_info *info,
1147 bool print_error)
1148{
1149 int i, ret;
1150
1151 switch (info->type) {
1152 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1153 case SNDRV_CTL_ELEM_TYPE_INTEGER:
1154 case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1155 case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1156 for (i = 0; i < info->count; i++) {
1157 ret = sanity_check_int_value(card, control, info, i,
1158 print_error);
1159 if (ret < 0)
1160 return ret;
1161 }
1162 break;
1163 default:
1164 break;
1165 }
1166
1167 return 0;
1168}
1169
1170/* perform sanity checks to the given snd_ctl_elem_value object */
1171static int sanity_check_elem_value(struct snd_card *card,
1172 const struct snd_ctl_elem_value *control,
1173 const struct snd_ctl_elem_info *info,
1174 u32 pattern)
1175{
1176 size_t offset;
1177 int ret;
1178 u32 *p;
1179
1180 ret = sanity_check_input_values(card, control, info, true);
1181 if (ret < 0)
1182 return ret;
1183
1184 /* check whether the remaining area kept untouched */
1185 offset = value_sizes[info->type] * info->count;
1186 offset = DIV_ROUND_UP(offset, sizeof(u32));
1187 p = (u32 *)control->value.bytes.data + offset;
1188 for (; offset < sizeof(control->value) / sizeof(u32); offset++, p++) {
1189 if (*p != pattern) {
1190 ret = -EINVAL;
1191 break;
1192 }
1193 *p = 0; /* clear the checked area */
1194 }
1195
1196 return ret;
1197}
1198
1199static int __snd_ctl_elem_info(struct snd_card *card,
1200 struct snd_kcontrol *kctl,
1201 struct snd_ctl_elem_info *info,
1202 struct snd_ctl_file *ctl)
1203{
1204 struct snd_kcontrol_volatile *vd;
1205 unsigned int index_offset;
1206 int result;
1207
1208#ifdef CONFIG_SND_DEBUG
1209 info->access = 0;
1210#endif
1211 result = snd_power_ref_and_wait(card);
1212 if (!result)
1213 result = kctl->info(kctl, info);
1214 snd_power_unref(card);
1215 if (result >= 0) {
1216 snd_BUG_ON(info->access);
1217 index_offset = snd_ctl_get_ioff(kctl, &info->id);
1218 vd = &kctl->vd[index_offset];
1219 snd_ctl_build_ioff(&info->id, kctl, index_offset);
1220 info->access = vd->access;
1221 if (vd->owner) {
1222 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
1223 if (vd->owner == ctl)
1224 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
1225 info->owner = pid_vnr(vd->owner->pid);
1226 } else {
1227 info->owner = -1;
1228 }
1229 if (!snd_ctl_skip_validation(info) &&
1230 snd_ctl_check_elem_info(card, info) < 0)
1231 result = -EINVAL;
1232 }
1233 return result;
1234}
1235
1236static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
1237 struct snd_ctl_elem_info *info)
1238{
1239 struct snd_card *card = ctl->card;
1240 struct snd_kcontrol *kctl;
1241 int result;
1242
1243 down_read(&card->controls_rwsem);
1244 kctl = snd_ctl_find_id_locked(card, &info->id);
1245 if (kctl == NULL)
1246 result = -ENOENT;
1247 else
1248 result = __snd_ctl_elem_info(card, kctl, info, ctl);
1249 up_read(&card->controls_rwsem);
1250 return result;
1251}
1252
1253static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
1254 struct snd_ctl_elem_info __user *_info)
1255{
1256 struct snd_ctl_elem_info info;
1257 int result;
1258
1259 if (copy_from_user(&info, _info, sizeof(info)))
1260 return -EFAULT;
1261 result = snd_ctl_elem_info(ctl, &info);
1262 if (result < 0)
1263 return result;
1264 /* drop internal access flags */
1265 info.access &= ~(SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK|
1266 SNDRV_CTL_ELEM_ACCESS_LED_MASK);
1267 if (copy_to_user(_info, &info, sizeof(info)))
1268 return -EFAULT;
1269 return result;
1270}
1271
1272static int snd_ctl_elem_read(struct snd_card *card,
1273 struct snd_ctl_elem_value *control)
1274{
1275 struct snd_kcontrol *kctl;
1276 struct snd_kcontrol_volatile *vd;
1277 unsigned int index_offset;
1278 struct snd_ctl_elem_info info;
1279 const u32 pattern = 0xdeadbeef;
1280 int ret;
1281
1282 down_read(&card->controls_rwsem);
1283 kctl = snd_ctl_find_id_locked(card, &control->id);
1284 if (kctl == NULL) {
1285 ret = -ENOENT;
1286 goto unlock;
1287 }
1288
1289 index_offset = snd_ctl_get_ioff(kctl, &control->id);
1290 vd = &kctl->vd[index_offset];
1291 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_READ) || kctl->get == NULL) {
1292 ret = -EPERM;
1293 goto unlock;
1294 }
1295
1296 snd_ctl_build_ioff(&control->id, kctl, index_offset);
1297
1298#ifdef CONFIG_SND_CTL_DEBUG
1299 /* info is needed only for validation */
1300 memset(&info, 0, sizeof(info));
1301 info.id = control->id;
1302 ret = __snd_ctl_elem_info(card, kctl, &info, NULL);
1303 if (ret < 0)
1304 goto unlock;
1305#endif
1306
1307 if (!snd_ctl_skip_validation(&info))
1308 fill_remaining_elem_value(control, &info, pattern);
1309 ret = snd_power_ref_and_wait(card);
1310 if (!ret)
1311 ret = kctl->get(kctl, control);
1312 snd_power_unref(card);
1313 if (ret < 0)
1314 goto unlock;
1315 if (!snd_ctl_skip_validation(&info) &&
1316 sanity_check_elem_value(card, control, &info, pattern) < 0) {
1317 dev_err(card->dev,
1318 "control %i:%i:%i:%s:%i: access overflow\n",
1319 control->id.iface, control->id.device,
1320 control->id.subdevice, control->id.name,
1321 control->id.index);
1322 ret = -EINVAL;
1323 goto unlock;
1324 }
1325unlock:
1326 up_read(&card->controls_rwsem);
1327 return ret;
1328}
1329
1330static int snd_ctl_elem_read_user(struct snd_card *card,
1331 struct snd_ctl_elem_value __user *_control)
1332{
1333 struct snd_ctl_elem_value *control;
1334 int result;
1335
1336 control = memdup_user(_control, sizeof(*control));
1337 if (IS_ERR(control))
1338 return PTR_ERR(control);
1339
1340 result = snd_ctl_elem_read(card, control);
1341 if (result < 0)
1342 goto error;
1343
1344 if (copy_to_user(_control, control, sizeof(*control)))
1345 result = -EFAULT;
1346 error:
1347 kfree(control);
1348 return result;
1349}
1350
1351static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
1352 struct snd_ctl_elem_value *control)
1353{
1354 struct snd_kcontrol *kctl;
1355 struct snd_kcontrol_volatile *vd;
1356 unsigned int index_offset;
1357 int result;
1358
1359 down_write(&card->controls_rwsem);
1360 kctl = snd_ctl_find_id_locked(card, &control->id);
1361 if (kctl == NULL) {
1362 up_write(&card->controls_rwsem);
1363 return -ENOENT;
1364 }
1365
1366 index_offset = snd_ctl_get_ioff(kctl, &control->id);
1367 vd = &kctl->vd[index_offset];
1368 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) || kctl->put == NULL ||
1369 (file && vd->owner && vd->owner != file)) {
1370 up_write(&card->controls_rwsem);
1371 return -EPERM;
1372 }
1373
1374 snd_ctl_build_ioff(&control->id, kctl, index_offset);
1375 result = snd_power_ref_and_wait(card);
1376 /* validate input values */
1377 if (IS_ENABLED(CONFIG_SND_CTL_INPUT_VALIDATION) && !result) {
1378 struct snd_ctl_elem_info info;
1379
1380 memset(&info, 0, sizeof(info));
1381 info.id = control->id;
1382 result = __snd_ctl_elem_info(card, kctl, &info, NULL);
1383 if (!result)
1384 result = sanity_check_input_values(card, control, &info,
1385 false);
1386 }
1387 if (!result)
1388 result = kctl->put(kctl, control);
1389 snd_power_unref(card);
1390 if (result < 0) {
1391 up_write(&card->controls_rwsem);
1392 return result;
1393 }
1394
1395 if (result > 0) {
1396 downgrade_write(&card->controls_rwsem);
1397 snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_VALUE, kctl, index_offset);
1398 up_read(&card->controls_rwsem);
1399 } else {
1400 up_write(&card->controls_rwsem);
1401 }
1402
1403 return 0;
1404}
1405
1406static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
1407 struct snd_ctl_elem_value __user *_control)
1408{
1409 struct snd_ctl_elem_value *control;
1410 struct snd_card *card;
1411 int result;
1412
1413 control = memdup_user(_control, sizeof(*control));
1414 if (IS_ERR(control))
1415 return PTR_ERR(control);
1416
1417 card = file->card;
1418 result = snd_ctl_elem_write(card, file, control);
1419 if (result < 0)
1420 goto error;
1421
1422 if (copy_to_user(_control, control, sizeof(*control)))
1423 result = -EFAULT;
1424 error:
1425 kfree(control);
1426 return result;
1427}
1428
1429static int snd_ctl_elem_lock(struct snd_ctl_file *file,
1430 struct snd_ctl_elem_id __user *_id)
1431{
1432 struct snd_card *card = file->card;
1433 struct snd_ctl_elem_id id;
1434 struct snd_kcontrol *kctl;
1435 struct snd_kcontrol_volatile *vd;
1436 int result;
1437
1438 if (copy_from_user(&id, _id, sizeof(id)))
1439 return -EFAULT;
1440 down_write(&card->controls_rwsem);
1441 kctl = snd_ctl_find_id_locked(card, &id);
1442 if (kctl == NULL) {
1443 result = -ENOENT;
1444 } else {
1445 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1446 if (vd->owner != NULL)
1447 result = -EBUSY;
1448 else {
1449 vd->owner = file;
1450 result = 0;
1451 }
1452 }
1453 up_write(&card->controls_rwsem);
1454 return result;
1455}
1456
1457static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
1458 struct snd_ctl_elem_id __user *_id)
1459{
1460 struct snd_card *card = file->card;
1461 struct snd_ctl_elem_id id;
1462 struct snd_kcontrol *kctl;
1463 struct snd_kcontrol_volatile *vd;
1464 int result;
1465
1466 if (copy_from_user(&id, _id, sizeof(id)))
1467 return -EFAULT;
1468 down_write(&card->controls_rwsem);
1469 kctl = snd_ctl_find_id_locked(card, &id);
1470 if (kctl == NULL) {
1471 result = -ENOENT;
1472 } else {
1473 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1474 if (vd->owner == NULL)
1475 result = -EINVAL;
1476 else if (vd->owner != file)
1477 result = -EPERM;
1478 else {
1479 vd->owner = NULL;
1480 result = 0;
1481 }
1482 }
1483 up_write(&card->controls_rwsem);
1484 return result;
1485}
1486
1487struct user_element {
1488 struct snd_ctl_elem_info info;
1489 struct snd_card *card;
1490 char *elem_data; /* element data */
1491 unsigned long elem_data_size; /* size of element data in bytes */
1492 void *tlv_data; /* TLV data */
1493 unsigned long tlv_data_size; /* TLV data size */
1494 void *priv_data; /* private data (like strings for enumerated type) */
1495};
1496
1497// check whether the addition (in bytes) of user ctl element may overflow the limit.
1498static bool check_user_elem_overflow(struct snd_card *card, ssize_t add)
1499{
1500 return (ssize_t)card->user_ctl_alloc_size + add > max_user_ctl_alloc_size;
1501}
1502
1503static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1504 struct snd_ctl_elem_info *uinfo)
1505{
1506 struct user_element *ue = kcontrol->private_data;
1507 unsigned int offset;
1508
1509 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1510 *uinfo = ue->info;
1511 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1512
1513 return 0;
1514}
1515
1516static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1517 struct snd_ctl_elem_info *uinfo)
1518{
1519 struct user_element *ue = kcontrol->private_data;
1520 const char *names;
1521 unsigned int item;
1522 unsigned int offset;
1523
1524 item = uinfo->value.enumerated.item;
1525
1526 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1527 *uinfo = ue->info;
1528 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1529
1530 item = min(item, uinfo->value.enumerated.items - 1);
1531 uinfo->value.enumerated.item = item;
1532
1533 names = ue->priv_data;
1534 for (; item > 0; --item)
1535 names += strlen(names) + 1;
1536 strcpy(uinfo->value.enumerated.name, names);
1537
1538 return 0;
1539}
1540
1541static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1542 struct snd_ctl_elem_value *ucontrol)
1543{
1544 struct user_element *ue = kcontrol->private_data;
1545 unsigned int size = ue->elem_data_size;
1546 char *src = ue->elem_data +
1547 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1548
1549 memcpy(&ucontrol->value, src, size);
1550 return 0;
1551}
1552
1553static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1554 struct snd_ctl_elem_value *ucontrol)
1555{
1556 int change;
1557 struct user_element *ue = kcontrol->private_data;
1558 unsigned int size = ue->elem_data_size;
1559 char *dst = ue->elem_data +
1560 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1561
1562 change = memcmp(&ucontrol->value, dst, size) != 0;
1563 if (change)
1564 memcpy(dst, &ucontrol->value, size);
1565 return change;
1566}
1567
1568/* called in controls_rwsem write lock */
1569static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
1570 unsigned int size)
1571{
1572 struct user_element *ue = kctl->private_data;
1573 unsigned int *container;
1574 unsigned int mask = 0;
1575 int i;
1576 int change;
1577
1578 lockdep_assert_held_write(&ue->card->controls_rwsem);
1579
1580 if (size > 1024 * 128) /* sane value */
1581 return -EINVAL;
1582
1583 // does the TLV size change cause overflow?
1584 if (check_user_elem_overflow(ue->card, (ssize_t)(size - ue->tlv_data_size)))
1585 return -ENOMEM;
1586
1587 container = vmemdup_user(buf, size);
1588 if (IS_ERR(container))
1589 return PTR_ERR(container);
1590
1591 change = ue->tlv_data_size != size;
1592 if (!change)
1593 change = memcmp(ue->tlv_data, container, size) != 0;
1594 if (!change) {
1595 kvfree(container);
1596 return 0;
1597 }
1598
1599 if (ue->tlv_data == NULL) {
1600 /* Now TLV data is available. */
1601 for (i = 0; i < kctl->count; ++i)
1602 kctl->vd[i].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
1603 mask = SNDRV_CTL_EVENT_MASK_INFO;
1604 } else {
1605 ue->card->user_ctl_alloc_size -= ue->tlv_data_size;
1606 ue->tlv_data_size = 0;
1607 kvfree(ue->tlv_data);
1608 }
1609
1610 ue->tlv_data = container;
1611 ue->tlv_data_size = size;
1612 // decremented at private_free.
1613 ue->card->user_ctl_alloc_size += size;
1614
1615 mask |= SNDRV_CTL_EVENT_MASK_TLV;
1616 for (i = 0; i < kctl->count; ++i)
1617 snd_ctl_notify_one(ue->card, mask, kctl, i);
1618
1619 return change;
1620}
1621
1622static int read_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
1623 unsigned int size)
1624{
1625 struct user_element *ue = kctl->private_data;
1626
1627 if (ue->tlv_data_size == 0 || ue->tlv_data == NULL)
1628 return -ENXIO;
1629
1630 if (size < ue->tlv_data_size)
1631 return -ENOSPC;
1632
1633 if (copy_to_user(buf, ue->tlv_data, ue->tlv_data_size))
1634 return -EFAULT;
1635
1636 return 0;
1637}
1638
1639static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kctl, int op_flag,
1640 unsigned int size, unsigned int __user *buf)
1641{
1642 if (op_flag == SNDRV_CTL_TLV_OP_WRITE)
1643 return replace_user_tlv(kctl, buf, size);
1644 else
1645 return read_user_tlv(kctl, buf, size);
1646}
1647
1648/* called in controls_rwsem write lock */
1649static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1650{
1651 char *names, *p;
1652 size_t buf_len, name_len;
1653 unsigned int i;
1654 const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1655
1656 lockdep_assert_held_write(&ue->card->controls_rwsem);
1657
1658 buf_len = ue->info.value.enumerated.names_length;
1659 if (buf_len > 64 * 1024)
1660 return -EINVAL;
1661
1662 if (check_user_elem_overflow(ue->card, buf_len))
1663 return -ENOMEM;
1664 names = vmemdup_user((const void __user *)user_ptrval, buf_len);
1665 if (IS_ERR(names))
1666 return PTR_ERR(names);
1667
1668 /* check that there are enough valid names */
1669 p = names;
1670 for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1671 name_len = strnlen(p, buf_len);
1672 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1673 kvfree(names);
1674 return -EINVAL;
1675 }
1676 p += name_len + 1;
1677 buf_len -= name_len + 1;
1678 }
1679
1680 ue->priv_data = names;
1681 ue->info.value.enumerated.names_ptr = 0;
1682 // increment the allocation size; decremented again at private_free.
1683 ue->card->user_ctl_alloc_size += ue->info.value.enumerated.names_length;
1684
1685 return 0;
1686}
1687
1688static size_t compute_user_elem_size(size_t size, unsigned int count)
1689{
1690 return sizeof(struct user_element) + size * count;
1691}
1692
1693static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1694{
1695 struct user_element *ue = kcontrol->private_data;
1696
1697 // decrement the allocation size.
1698 ue->card->user_ctl_alloc_size -= compute_user_elem_size(ue->elem_data_size, kcontrol->count);
1699 ue->card->user_ctl_alloc_size -= ue->tlv_data_size;
1700 if (ue->priv_data)
1701 ue->card->user_ctl_alloc_size -= ue->info.value.enumerated.names_length;
1702
1703 kvfree(ue->tlv_data);
1704 kvfree(ue->priv_data);
1705 kfree(ue);
1706}
1707
1708static int snd_ctl_elem_add(struct snd_ctl_file *file,
1709 struct snd_ctl_elem_info *info, int replace)
1710{
1711 struct snd_card *card = file->card;
1712 struct snd_kcontrol *kctl;
1713 unsigned int count;
1714 unsigned int access;
1715 long private_size;
1716 size_t alloc_size;
1717 struct user_element *ue;
1718 unsigned int offset;
1719 int err;
1720
1721 if (!*info->id.name)
1722 return -EINVAL;
1723 if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
1724 return -EINVAL;
1725
1726 /* Delete a control to replace them if needed. */
1727 if (replace) {
1728 info->id.numid = 0;
1729 err = snd_ctl_remove_user_ctl(file, &info->id);
1730 if (err)
1731 return err;
1732 }
1733
1734 /* Check the number of elements for this userspace control. */
1735 count = info->owner;
1736 if (count == 0)
1737 count = 1;
1738
1739 /* Arrange access permissions if needed. */
1740 access = info->access;
1741 if (access == 0)
1742 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
1743 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
1744 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
1745 SNDRV_CTL_ELEM_ACCESS_TLV_WRITE);
1746
1747 /* In initial state, nothing is available as TLV container. */
1748 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
1749 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1750 access |= SNDRV_CTL_ELEM_ACCESS_USER;
1751
1752 /*
1753 * Check information and calculate the size of data specific to
1754 * this userspace control.
1755 */
1756 /* pass NULL to card for suppressing error messages */
1757 err = snd_ctl_check_elem_info(NULL, info);
1758 if (err < 0)
1759 return err;
1760 /* user-space control doesn't allow zero-size data */
1761 if (info->count < 1)
1762 return -EINVAL;
1763 private_size = value_sizes[info->type] * info->count;
1764 alloc_size = compute_user_elem_size(private_size, count);
1765
1766 down_write(&card->controls_rwsem);
1767 if (check_user_elem_overflow(card, alloc_size)) {
1768 err = -ENOMEM;
1769 goto unlock;
1770 }
1771
1772 /*
1773 * Keep memory object for this userspace control. After passing this
1774 * code block, the instance should be freed by snd_ctl_free_one().
1775 *
1776 * Note that these elements in this control are locked.
1777 */
1778 err = snd_ctl_new(&kctl, count, access, file);
1779 if (err < 0)
1780 goto unlock;
1781 memcpy(&kctl->id, &info->id, sizeof(kctl->id));
1782 ue = kzalloc(alloc_size, GFP_KERNEL);
1783 if (!ue) {
1784 kfree(kctl);
1785 err = -ENOMEM;
1786 goto unlock;
1787 }
1788 kctl->private_data = ue;
1789 kctl->private_free = snd_ctl_elem_user_free;
1790
1791 // increment the allocated size; decremented again at private_free.
1792 card->user_ctl_alloc_size += alloc_size;
1793
1794 /* Set private data for this userspace control. */
1795 ue->card = card;
1796 ue->info = *info;
1797 ue->info.access = 0;
1798 ue->elem_data = (char *)ue + sizeof(*ue);
1799 ue->elem_data_size = private_size;
1800 if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1801 err = snd_ctl_elem_init_enum_names(ue);
1802 if (err < 0) {
1803 snd_ctl_free_one(kctl);
1804 goto unlock;
1805 }
1806 }
1807
1808 /* Set callback functions. */
1809 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1810 kctl->info = snd_ctl_elem_user_enum_info;
1811 else
1812 kctl->info = snd_ctl_elem_user_info;
1813 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1814 kctl->get = snd_ctl_elem_user_get;
1815 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1816 kctl->put = snd_ctl_elem_user_put;
1817 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
1818 kctl->tlv.c = snd_ctl_elem_user_tlv;
1819
1820 /* This function manage to free the instance on failure. */
1821 err = __snd_ctl_add_replace(card, kctl, CTL_ADD_EXCLUSIVE);
1822 if (err < 0) {
1823 snd_ctl_free_one(kctl);
1824 goto unlock;
1825 }
1826 offset = snd_ctl_get_ioff(kctl, &info->id);
1827 snd_ctl_build_ioff(&info->id, kctl, offset);
1828 /*
1829 * Here we cannot fill any field for the number of elements added by
1830 * this operation because there're no specific fields. The usage of
1831 * 'owner' field for this purpose may cause any bugs to userspace
1832 * applications because the field originally means PID of a process
1833 * which locks the element.
1834 */
1835 unlock:
1836 up_write(&card->controls_rwsem);
1837 return err;
1838}
1839
1840static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1841 struct snd_ctl_elem_info __user *_info, int replace)
1842{
1843 struct snd_ctl_elem_info info;
1844 int err;
1845
1846 if (copy_from_user(&info, _info, sizeof(info)))
1847 return -EFAULT;
1848 err = snd_ctl_elem_add(file, &info, replace);
1849 if (err < 0)
1850 return err;
1851 if (copy_to_user(_info, &info, sizeof(info))) {
1852 snd_ctl_remove_user_ctl(file, &info.id);
1853 return -EFAULT;
1854 }
1855
1856 return 0;
1857}
1858
1859static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1860 struct snd_ctl_elem_id __user *_id)
1861{
1862 struct snd_ctl_elem_id id;
1863
1864 if (copy_from_user(&id, _id, sizeof(id)))
1865 return -EFAULT;
1866 return snd_ctl_remove_user_ctl(file, &id);
1867}
1868
1869static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1870{
1871 int subscribe;
1872 if (get_user(subscribe, ptr))
1873 return -EFAULT;
1874 if (subscribe < 0) {
1875 subscribe = file->subscribed;
1876 if (put_user(subscribe, ptr))
1877 return -EFAULT;
1878 return 0;
1879 }
1880 if (subscribe) {
1881 file->subscribed = 1;
1882 return 0;
1883 } else if (file->subscribed) {
1884 snd_ctl_empty_read_queue(file);
1885 file->subscribed = 0;
1886 }
1887 return 0;
1888}
1889
1890static int call_tlv_handler(struct snd_ctl_file *file, int op_flag,
1891 struct snd_kcontrol *kctl,
1892 struct snd_ctl_elem_id *id,
1893 unsigned int __user *buf, unsigned int size)
1894{
1895 static const struct {
1896 int op;
1897 int perm;
1898 } pairs[] = {
1899 {SNDRV_CTL_TLV_OP_READ, SNDRV_CTL_ELEM_ACCESS_TLV_READ},
1900 {SNDRV_CTL_TLV_OP_WRITE, SNDRV_CTL_ELEM_ACCESS_TLV_WRITE},
1901 {SNDRV_CTL_TLV_OP_CMD, SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND},
1902 };
1903 struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
1904 int i, ret;
1905
1906 /* Check support of the request for this element. */
1907 for (i = 0; i < ARRAY_SIZE(pairs); ++i) {
1908 if (op_flag == pairs[i].op && (vd->access & pairs[i].perm))
1909 break;
1910 }
1911 if (i == ARRAY_SIZE(pairs))
1912 return -ENXIO;
1913
1914 if (kctl->tlv.c == NULL)
1915 return -ENXIO;
1916
1917 /* Write and command operations are not allowed for locked element. */
1918 if (op_flag != SNDRV_CTL_TLV_OP_READ &&
1919 vd->owner != NULL && vd->owner != file)
1920 return -EPERM;
1921
1922 ret = snd_power_ref_and_wait(file->card);
1923 if (!ret)
1924 ret = kctl->tlv.c(kctl, op_flag, size, buf);
1925 snd_power_unref(file->card);
1926 return ret;
1927}
1928
1929static int read_tlv_buf(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id,
1930 unsigned int __user *buf, unsigned int size)
1931{
1932 struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
1933 unsigned int len;
1934
1935 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ))
1936 return -ENXIO;
1937
1938 if (kctl->tlv.p == NULL)
1939 return -ENXIO;
1940
1941 len = sizeof(unsigned int) * 2 + kctl->tlv.p[1];
1942 if (size < len)
1943 return -ENOMEM;
1944
1945 if (copy_to_user(buf, kctl->tlv.p, len))
1946 return -EFAULT;
1947
1948 return 0;
1949}
1950
1951static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1952 struct snd_ctl_tlv __user *buf,
1953 int op_flag)
1954{
1955 struct snd_ctl_tlv header;
1956 unsigned int __user *container;
1957 unsigned int container_size;
1958 struct snd_kcontrol *kctl;
1959 struct snd_ctl_elem_id id;
1960 struct snd_kcontrol_volatile *vd;
1961
1962 lockdep_assert_held(&file->card->controls_rwsem);
1963
1964 if (copy_from_user(&header, buf, sizeof(header)))
1965 return -EFAULT;
1966
1967 /* In design of control core, numerical ID starts at 1. */
1968 if (header.numid == 0)
1969 return -EINVAL;
1970
1971 /* At least, container should include type and length fields. */
1972 if (header.length < sizeof(unsigned int) * 2)
1973 return -EINVAL;
1974 container_size = header.length;
1975 container = buf->tlv;
1976
1977 kctl = snd_ctl_find_numid_locked(file->card, header.numid);
1978 if (kctl == NULL)
1979 return -ENOENT;
1980
1981 /* Calculate index of the element in this set. */
1982 id = kctl->id;
1983 snd_ctl_build_ioff(&id, kctl, header.numid - id.numid);
1984 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1985
1986 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1987 return call_tlv_handler(file, op_flag, kctl, &id, container,
1988 container_size);
1989 } else {
1990 if (op_flag == SNDRV_CTL_TLV_OP_READ) {
1991 return read_tlv_buf(kctl, &id, container,
1992 container_size);
1993 }
1994 }
1995
1996 /* Not supported. */
1997 return -ENXIO;
1998}
1999
2000static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2001{
2002 struct snd_ctl_file *ctl;
2003 struct snd_card *card;
2004 struct snd_kctl_ioctl *p;
2005 void __user *argp = (void __user *)arg;
2006 int __user *ip = argp;
2007 int err;
2008
2009 ctl = file->private_data;
2010 card = ctl->card;
2011 if (snd_BUG_ON(!card))
2012 return -ENXIO;
2013 switch (cmd) {
2014 case SNDRV_CTL_IOCTL_PVERSION:
2015 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
2016 case SNDRV_CTL_IOCTL_CARD_INFO:
2017 return snd_ctl_card_info(card, ctl, cmd, argp);
2018 case SNDRV_CTL_IOCTL_ELEM_LIST:
2019 return snd_ctl_elem_list_user(card, argp);
2020 case SNDRV_CTL_IOCTL_ELEM_INFO:
2021 return snd_ctl_elem_info_user(ctl, argp);
2022 case SNDRV_CTL_IOCTL_ELEM_READ:
2023 return snd_ctl_elem_read_user(card, argp);
2024 case SNDRV_CTL_IOCTL_ELEM_WRITE:
2025 return snd_ctl_elem_write_user(ctl, argp);
2026 case SNDRV_CTL_IOCTL_ELEM_LOCK:
2027 return snd_ctl_elem_lock(ctl, argp);
2028 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
2029 return snd_ctl_elem_unlock(ctl, argp);
2030 case SNDRV_CTL_IOCTL_ELEM_ADD:
2031 return snd_ctl_elem_add_user(ctl, argp, 0);
2032 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
2033 return snd_ctl_elem_add_user(ctl, argp, 1);
2034 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
2035 return snd_ctl_elem_remove(ctl, argp);
2036 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
2037 return snd_ctl_subscribe_events(ctl, ip);
2038 case SNDRV_CTL_IOCTL_TLV_READ:
2039 down_read(&ctl->card->controls_rwsem);
2040 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
2041 up_read(&ctl->card->controls_rwsem);
2042 return err;
2043 case SNDRV_CTL_IOCTL_TLV_WRITE:
2044 down_write(&ctl->card->controls_rwsem);
2045 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
2046 up_write(&ctl->card->controls_rwsem);
2047 return err;
2048 case SNDRV_CTL_IOCTL_TLV_COMMAND:
2049 down_write(&ctl->card->controls_rwsem);
2050 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
2051 up_write(&ctl->card->controls_rwsem);
2052 return err;
2053 case SNDRV_CTL_IOCTL_POWER:
2054 return -ENOPROTOOPT;
2055 case SNDRV_CTL_IOCTL_POWER_STATE:
2056 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
2057 }
2058 down_read(&snd_ioctl_rwsem);
2059 list_for_each_entry(p, &snd_control_ioctls, list) {
2060 err = p->fioctl(card, ctl, cmd, arg);
2061 if (err != -ENOIOCTLCMD) {
2062 up_read(&snd_ioctl_rwsem);
2063 return err;
2064 }
2065 }
2066 up_read(&snd_ioctl_rwsem);
2067 dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
2068 return -ENOTTY;
2069}
2070
2071static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
2072 size_t count, loff_t * offset)
2073{
2074 struct snd_ctl_file *ctl;
2075 int err = 0;
2076 ssize_t result = 0;
2077
2078 ctl = file->private_data;
2079 if (snd_BUG_ON(!ctl || !ctl->card))
2080 return -ENXIO;
2081 if (!ctl->subscribed)
2082 return -EBADFD;
2083 if (count < sizeof(struct snd_ctl_event))
2084 return -EINVAL;
2085 spin_lock_irq(&ctl->read_lock);
2086 while (count >= sizeof(struct snd_ctl_event)) {
2087 struct snd_ctl_event ev;
2088 struct snd_kctl_event *kev;
2089 while (list_empty(&ctl->events)) {
2090 wait_queue_entry_t wait;
2091 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
2092 err = -EAGAIN;
2093 goto __end_lock;
2094 }
2095 init_waitqueue_entry(&wait, current);
2096 add_wait_queue(&ctl->change_sleep, &wait);
2097 set_current_state(TASK_INTERRUPTIBLE);
2098 spin_unlock_irq(&ctl->read_lock);
2099 schedule();
2100 remove_wait_queue(&ctl->change_sleep, &wait);
2101 if (ctl->card->shutdown)
2102 return -ENODEV;
2103 if (signal_pending(current))
2104 return -ERESTARTSYS;
2105 spin_lock_irq(&ctl->read_lock);
2106 }
2107 kev = snd_kctl_event(ctl->events.next);
2108 ev.type = SNDRV_CTL_EVENT_ELEM;
2109 ev.data.elem.mask = kev->mask;
2110 ev.data.elem.id = kev->id;
2111 list_del(&kev->list);
2112 spin_unlock_irq(&ctl->read_lock);
2113 kfree(kev);
2114 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
2115 err = -EFAULT;
2116 goto __end;
2117 }
2118 spin_lock_irq(&ctl->read_lock);
2119 buffer += sizeof(struct snd_ctl_event);
2120 count -= sizeof(struct snd_ctl_event);
2121 result += sizeof(struct snd_ctl_event);
2122 }
2123 __end_lock:
2124 spin_unlock_irq(&ctl->read_lock);
2125 __end:
2126 return result > 0 ? result : err;
2127}
2128
2129static __poll_t snd_ctl_poll(struct file *file, poll_table * wait)
2130{
2131 __poll_t mask;
2132 struct snd_ctl_file *ctl;
2133
2134 ctl = file->private_data;
2135 if (!ctl->subscribed)
2136 return 0;
2137 poll_wait(file, &ctl->change_sleep, wait);
2138
2139 mask = 0;
2140 if (!list_empty(&ctl->events))
2141 mask |= EPOLLIN | EPOLLRDNORM;
2142
2143 return mask;
2144}
2145
2146/*
2147 * register the device-specific control-ioctls.
2148 * called from each device manager like pcm.c, hwdep.c, etc.
2149 */
2150static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
2151{
2152 struct snd_kctl_ioctl *pn;
2153
2154 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
2155 if (pn == NULL)
2156 return -ENOMEM;
2157 pn->fioctl = fcn;
2158 down_write(&snd_ioctl_rwsem);
2159 list_add_tail(&pn->list, lists);
2160 up_write(&snd_ioctl_rwsem);
2161 return 0;
2162}
2163
2164/**
2165 * snd_ctl_register_ioctl - register the device-specific control-ioctls
2166 * @fcn: ioctl callback function
2167 *
2168 * called from each device manager like pcm.c, hwdep.c, etc.
2169 *
2170 * Return: zero if successful, or a negative error code
2171 */
2172int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
2173{
2174 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
2175}
2176EXPORT_SYMBOL(snd_ctl_register_ioctl);
2177
2178#ifdef CONFIG_COMPAT
2179/**
2180 * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
2181 * control-ioctls
2182 * @fcn: ioctl callback function
2183 *
2184 * Return: zero if successful, or a negative error code
2185 */
2186int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
2187{
2188 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
2189}
2190EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
2191#endif
2192
2193/*
2194 * de-register the device-specific control-ioctls.
2195 */
2196static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
2197 struct list_head *lists)
2198{
2199 struct snd_kctl_ioctl *p;
2200
2201 if (snd_BUG_ON(!fcn))
2202 return -EINVAL;
2203 down_write(&snd_ioctl_rwsem);
2204 list_for_each_entry(p, lists, list) {
2205 if (p->fioctl == fcn) {
2206 list_del(&p->list);
2207 up_write(&snd_ioctl_rwsem);
2208 kfree(p);
2209 return 0;
2210 }
2211 }
2212 up_write(&snd_ioctl_rwsem);
2213 snd_BUG();
2214 return -EINVAL;
2215}
2216
2217/**
2218 * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
2219 * @fcn: ioctl callback function to unregister
2220 *
2221 * Return: zero if successful, or a negative error code
2222 */
2223int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
2224{
2225 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
2226}
2227EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
2228
2229#ifdef CONFIG_COMPAT
2230/**
2231 * snd_ctl_unregister_ioctl_compat - de-register the device-specific compat
2232 * 32bit control-ioctls
2233 * @fcn: ioctl callback function to unregister
2234 *
2235 * Return: zero if successful, or a negative error code
2236 */
2237int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
2238{
2239 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
2240}
2241EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
2242#endif
2243
2244static int snd_ctl_fasync(int fd, struct file * file, int on)
2245{
2246 struct snd_ctl_file *ctl;
2247
2248 ctl = file->private_data;
2249 return snd_fasync_helper(fd, file, on, &ctl->fasync);
2250}
2251
2252/* return the preferred subdevice number if already assigned;
2253 * otherwise return -1
2254 */
2255int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
2256{
2257 struct snd_ctl_file *kctl;
2258 int subdevice = -1;
2259 unsigned long flags;
2260
2261 read_lock_irqsave(&card->ctl_files_rwlock, flags);
2262 list_for_each_entry(kctl, &card->ctl_files, list) {
2263 if (kctl->pid == task_pid(current)) {
2264 subdevice = kctl->preferred_subdevice[type];
2265 if (subdevice != -1)
2266 break;
2267 }
2268 }
2269 read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
2270 return subdevice;
2271}
2272EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);
2273
2274/*
2275 * ioctl32 compat
2276 */
2277#ifdef CONFIG_COMPAT
2278#include "control_compat.c"
2279#else
2280#define snd_ctl_ioctl_compat NULL
2281#endif
2282
2283/*
2284 * control layers (audio LED etc.)
2285 */
2286
2287/**
2288 * snd_ctl_request_layer - request to use the layer
2289 * @module_name: Name of the kernel module (NULL == build-in)
2290 *
2291 * Return: zero if successful, or an error code when the module cannot be loaded
2292 */
2293int snd_ctl_request_layer(const char *module_name)
2294{
2295 struct snd_ctl_layer_ops *lops;
2296
2297 if (module_name == NULL)
2298 return 0;
2299 down_read(&snd_ctl_layer_rwsem);
2300 for (lops = snd_ctl_layer; lops; lops = lops->next)
2301 if (strcmp(lops->module_name, module_name) == 0)
2302 break;
2303 up_read(&snd_ctl_layer_rwsem);
2304 if (lops)
2305 return 0;
2306 return request_module(module_name);
2307}
2308EXPORT_SYMBOL_GPL(snd_ctl_request_layer);
2309
2310/**
2311 * snd_ctl_register_layer - register new control layer
2312 * @lops: operation structure
2313 *
2314 * The new layer can track all control elements and do additional
2315 * operations on top (like audio LED handling).
2316 */
2317void snd_ctl_register_layer(struct snd_ctl_layer_ops *lops)
2318{
2319 struct snd_card *card;
2320 int card_number;
2321
2322 down_write(&snd_ctl_layer_rwsem);
2323 lops->next = snd_ctl_layer;
2324 snd_ctl_layer = lops;
2325 up_write(&snd_ctl_layer_rwsem);
2326 for (card_number = 0; card_number < SNDRV_CARDS; card_number++) {
2327 card = snd_card_ref(card_number);
2328 if (card) {
2329 down_read(&card->controls_rwsem);
2330 lops->lregister(card);
2331 up_read(&card->controls_rwsem);
2332 snd_card_unref(card);
2333 }
2334 }
2335}
2336EXPORT_SYMBOL_GPL(snd_ctl_register_layer);
2337
2338/**
2339 * snd_ctl_disconnect_layer - disconnect control layer
2340 * @lops: operation structure
2341 *
2342 * It is expected that the information about tracked cards
2343 * is freed before this call (the disconnect callback is
2344 * not called here).
2345 */
2346void snd_ctl_disconnect_layer(struct snd_ctl_layer_ops *lops)
2347{
2348 struct snd_ctl_layer_ops *lops2, *prev_lops2;
2349
2350 down_write(&snd_ctl_layer_rwsem);
2351 for (lops2 = snd_ctl_layer, prev_lops2 = NULL; lops2; lops2 = lops2->next) {
2352 if (lops2 == lops) {
2353 if (!prev_lops2)
2354 snd_ctl_layer = lops->next;
2355 else
2356 prev_lops2->next = lops->next;
2357 break;
2358 }
2359 prev_lops2 = lops2;
2360 }
2361 up_write(&snd_ctl_layer_rwsem);
2362}
2363EXPORT_SYMBOL_GPL(snd_ctl_disconnect_layer);
2364
2365/*
2366 * INIT PART
2367 */
2368
2369static const struct file_operations snd_ctl_f_ops =
2370{
2371 .owner = THIS_MODULE,
2372 .read = snd_ctl_read,
2373 .open = snd_ctl_open,
2374 .release = snd_ctl_release,
2375 .llseek = no_llseek,
2376 .poll = snd_ctl_poll,
2377 .unlocked_ioctl = snd_ctl_ioctl,
2378 .compat_ioctl = snd_ctl_ioctl_compat,
2379 .fasync = snd_ctl_fasync,
2380};
2381
2382/*
2383 * registration of the control device
2384 */
2385static int snd_ctl_dev_register(struct snd_device *device)
2386{
2387 struct snd_card *card = device->device_data;
2388 struct snd_ctl_layer_ops *lops;
2389 int err;
2390
2391 err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
2392 &snd_ctl_f_ops, card, card->ctl_dev);
2393 if (err < 0)
2394 return err;
2395 down_read(&card->controls_rwsem);
2396 down_read(&snd_ctl_layer_rwsem);
2397 for (lops = snd_ctl_layer; lops; lops = lops->next)
2398 lops->lregister(card);
2399 up_read(&snd_ctl_layer_rwsem);
2400 up_read(&card->controls_rwsem);
2401 return 0;
2402}
2403
2404/*
2405 * disconnection of the control device
2406 */
2407static int snd_ctl_dev_disconnect(struct snd_device *device)
2408{
2409 struct snd_card *card = device->device_data;
2410 struct snd_ctl_file *ctl;
2411 struct snd_ctl_layer_ops *lops;
2412 unsigned long flags;
2413
2414 read_lock_irqsave(&card->ctl_files_rwlock, flags);
2415 list_for_each_entry(ctl, &card->ctl_files, list) {
2416 wake_up(&ctl->change_sleep);
2417 snd_kill_fasync(ctl->fasync, SIGIO, POLL_ERR);
2418 }
2419 read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
2420
2421 down_read(&card->controls_rwsem);
2422 down_read(&snd_ctl_layer_rwsem);
2423 for (lops = snd_ctl_layer; lops; lops = lops->next)
2424 lops->ldisconnect(card);
2425 up_read(&snd_ctl_layer_rwsem);
2426 up_read(&card->controls_rwsem);
2427
2428 return snd_unregister_device(card->ctl_dev);
2429}
2430
2431/*
2432 * free all controls
2433 */
2434static int snd_ctl_dev_free(struct snd_device *device)
2435{
2436 struct snd_card *card = device->device_data;
2437 struct snd_kcontrol *control;
2438
2439 down_write(&card->controls_rwsem);
2440 while (!list_empty(&card->controls)) {
2441 control = snd_kcontrol(card->controls.next);
2442 __snd_ctl_remove(card, control, false);
2443 }
2444
2445#ifdef CONFIG_SND_CTL_FAST_LOOKUP
2446 xa_destroy(&card->ctl_numids);
2447 xa_destroy(&card->ctl_hash);
2448#endif
2449 up_write(&card->controls_rwsem);
2450 put_device(card->ctl_dev);
2451 return 0;
2452}
2453
2454/*
2455 * create control core:
2456 * called from init.c
2457 */
2458int snd_ctl_create(struct snd_card *card)
2459{
2460 static const struct snd_device_ops ops = {
2461 .dev_free = snd_ctl_dev_free,
2462 .dev_register = snd_ctl_dev_register,
2463 .dev_disconnect = snd_ctl_dev_disconnect,
2464 };
2465 int err;
2466
2467 if (snd_BUG_ON(!card))
2468 return -ENXIO;
2469 if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS))
2470 return -ENXIO;
2471
2472 err = snd_device_alloc(&card->ctl_dev, card);
2473 if (err < 0)
2474 return err;
2475 dev_set_name(card->ctl_dev, "controlC%d", card->number);
2476
2477 err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
2478 if (err < 0)
2479 put_device(card->ctl_dev);
2480 return err;
2481}
2482
2483/*
2484 * Frequently used control callbacks/helpers
2485 */
2486
2487/**
2488 * snd_ctl_boolean_mono_info - Helper function for a standard boolean info
2489 * callback with a mono channel
2490 * @kcontrol: the kcontrol instance
2491 * @uinfo: info to store
2492 *
2493 * This is a function that can be used as info callback for a standard
2494 * boolean control with a single mono channel.
2495 *
2496 * Return: Zero (always successful)
2497 */
2498int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
2499 struct snd_ctl_elem_info *uinfo)
2500{
2501 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
2502 uinfo->count = 1;
2503 uinfo->value.integer.min = 0;
2504 uinfo->value.integer.max = 1;
2505 return 0;
2506}
2507EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
2508
2509/**
2510 * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info
2511 * callback with stereo two channels
2512 * @kcontrol: the kcontrol instance
2513 * @uinfo: info to store
2514 *
2515 * This is a function that can be used as info callback for a standard
2516 * boolean control with stereo two channels.
2517 *
2518 * Return: Zero (always successful)
2519 */
2520int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
2521 struct snd_ctl_elem_info *uinfo)
2522{
2523 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
2524 uinfo->count = 2;
2525 uinfo->value.integer.min = 0;
2526 uinfo->value.integer.max = 1;
2527 return 0;
2528}
2529EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
2530
2531/**
2532 * snd_ctl_enum_info - fills the info structure for an enumerated control
2533 * @info: the structure to be filled
2534 * @channels: the number of the control's channels; often one
2535 * @items: the number of control values; also the size of @names
2536 * @names: an array containing the names of all control values
2537 *
2538 * Sets all required fields in @info to their appropriate values.
2539 * If the control's accessibility is not the default (readable and writable),
2540 * the caller has to fill @info->access.
2541 *
2542 * Return: Zero (always successful)
2543 */
2544int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
2545 unsigned int items, const char *const names[])
2546{
2547 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
2548 info->count = channels;
2549 info->value.enumerated.items = items;
2550 if (!items)
2551 return 0;
2552 if (info->value.enumerated.item >= items)
2553 info->value.enumerated.item = items - 1;
2554 WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
2555 "ALSA: too long item name '%s'\n",
2556 names[info->value.enumerated.item]);
2557 strscpy(info->value.enumerated.name,
2558 names[info->value.enumerated.item],
2559 sizeof(info->value.enumerated.name));
2560 return 0;
2561}
2562EXPORT_SYMBOL(snd_ctl_enum_info);