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