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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/*
2 * Routines for driver control interface
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4 *
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 */
21
22#include <linux/threads.h>
23#include <linux/interrupt.h>
24#include <linux/module.h>
25#include <linux/slab.h>
26#include <linux/vmalloc.h>
27#include <linux/time.h>
28#include <linux/mm.h>
29#include <linux/sched/signal.h>
30#include <sound/core.h>
31#include <sound/minors.h>
32#include <sound/info.h>
33#include <sound/control.h>
34
35/* max number of user-defined controls */
36#define MAX_USER_CONTROLS 32
37#define MAX_CONTROL_COUNT 1028
38
39struct snd_kctl_ioctl {
40 struct list_head list; /* list of all ioctls */
41 snd_kctl_ioctl_func_t fioctl;
42};
43
44static DECLARE_RWSEM(snd_ioctl_rwsem);
45static LIST_HEAD(snd_control_ioctls);
46#ifdef CONFIG_COMPAT
47static LIST_HEAD(snd_control_compat_ioctls);
48#endif
49
50static int snd_ctl_open(struct inode *inode, struct file *file)
51{
52 unsigned long flags;
53 struct snd_card *card;
54 struct snd_ctl_file *ctl;
55 int i, err;
56
57 err = nonseekable_open(inode, file);
58 if (err < 0)
59 return err;
60
61 card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
62 if (!card) {
63 err = -ENODEV;
64 goto __error1;
65 }
66 err = snd_card_file_add(card, file);
67 if (err < 0) {
68 err = -ENODEV;
69 goto __error1;
70 }
71 if (!try_module_get(card->module)) {
72 err = -EFAULT;
73 goto __error2;
74 }
75 ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
76 if (ctl == NULL) {
77 err = -ENOMEM;
78 goto __error;
79 }
80 INIT_LIST_HEAD(&ctl->events);
81 init_waitqueue_head(&ctl->change_sleep);
82 spin_lock_init(&ctl->read_lock);
83 ctl->card = card;
84 for (i = 0; i < SND_CTL_SUBDEV_ITEMS; i++)
85 ctl->preferred_subdevice[i] = -1;
86 ctl->pid = get_pid(task_pid(current));
87 file->private_data = ctl;
88 write_lock_irqsave(&card->ctl_files_rwlock, flags);
89 list_add_tail(&ctl->list, &card->ctl_files);
90 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
91 snd_card_unref(card);
92 return 0;
93
94 __error:
95 module_put(card->module);
96 __error2:
97 snd_card_file_remove(card, file);
98 __error1:
99 if (card)
100 snd_card_unref(card);
101 return err;
102}
103
104static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
105{
106 unsigned long flags;
107 struct snd_kctl_event *cread;
108
109 spin_lock_irqsave(&ctl->read_lock, flags);
110 while (!list_empty(&ctl->events)) {
111 cread = snd_kctl_event(ctl->events.next);
112 list_del(&cread->list);
113 kfree(cread);
114 }
115 spin_unlock_irqrestore(&ctl->read_lock, flags);
116}
117
118static int snd_ctl_release(struct inode *inode, struct file *file)
119{
120 unsigned long flags;
121 struct snd_card *card;
122 struct snd_ctl_file *ctl;
123 struct snd_kcontrol *control;
124 unsigned int idx;
125
126 ctl = file->private_data;
127 file->private_data = NULL;
128 card = ctl->card;
129 write_lock_irqsave(&card->ctl_files_rwlock, flags);
130 list_del(&ctl->list);
131 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
132 down_write(&card->controls_rwsem);
133 list_for_each_entry(control, &card->controls, list)
134 for (idx = 0; idx < control->count; idx++)
135 if (control->vd[idx].owner == ctl)
136 control->vd[idx].owner = NULL;
137 up_write(&card->controls_rwsem);
138 snd_ctl_empty_read_queue(ctl);
139 put_pid(ctl->pid);
140 kfree(ctl);
141 module_put(card->module);
142 snd_card_file_remove(card, file);
143 return 0;
144}
145
146/**
147 * snd_ctl_notify - Send notification to user-space for a control change
148 * @card: the card to send notification
149 * @mask: the event mask, SNDRV_CTL_EVENT_*
150 * @id: the ctl element id to send notification
151 *
152 * This function adds an event record with the given id and mask, appends
153 * to the list and wakes up the user-space for notification. This can be
154 * called in the atomic context.
155 */
156void snd_ctl_notify(struct snd_card *card, unsigned int mask,
157 struct snd_ctl_elem_id *id)
158{
159 unsigned long flags;
160 struct snd_ctl_file *ctl;
161 struct snd_kctl_event *ev;
162
163 if (snd_BUG_ON(!card || !id))
164 return;
165 if (card->shutdown)
166 return;
167 read_lock(&card->ctl_files_rwlock);
168#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
169 card->mixer_oss_change_count++;
170#endif
171 list_for_each_entry(ctl, &card->ctl_files, list) {
172 if (!ctl->subscribed)
173 continue;
174 spin_lock_irqsave(&ctl->read_lock, flags);
175 list_for_each_entry(ev, &ctl->events, list) {
176 if (ev->id.numid == id->numid) {
177 ev->mask |= mask;
178 goto _found;
179 }
180 }
181 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
182 if (ev) {
183 ev->id = *id;
184 ev->mask = mask;
185 list_add_tail(&ev->list, &ctl->events);
186 } else {
187 dev_err(card->dev, "No memory available to allocate event\n");
188 }
189 _found:
190 wake_up(&ctl->change_sleep);
191 spin_unlock_irqrestore(&ctl->read_lock, flags);
192 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
193 }
194 read_unlock(&card->ctl_files_rwlock);
195}
196EXPORT_SYMBOL(snd_ctl_notify);
197
198/**
199 * snd_ctl_new - create a new control instance with some elements
200 * @kctl: the pointer to store new control instance
201 * @count: the number of elements in this control
202 * @access: the default access flags for elements in this control
203 * @file: given when locking these elements
204 *
205 * Allocates a memory object for a new control instance. The instance has
206 * elements as many as the given number (@count). Each element has given
207 * access permissions (@access). Each element is locked when @file is given.
208 *
209 * Return: 0 on success, error code on failure
210 */
211static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count,
212 unsigned int access, struct snd_ctl_file *file)
213{
214 unsigned int size;
215 unsigned int idx;
216
217 if (count == 0 || count > MAX_CONTROL_COUNT)
218 return -EINVAL;
219
220 size = sizeof(struct snd_kcontrol);
221 size += sizeof(struct snd_kcontrol_volatile) * count;
222
223 *kctl = kzalloc(size, GFP_KERNEL);
224 if (!*kctl)
225 return -ENOMEM;
226
227 for (idx = 0; idx < count; idx++) {
228 (*kctl)->vd[idx].access = access;
229 (*kctl)->vd[idx].owner = file;
230 }
231 (*kctl)->count = count;
232
233 return 0;
234}
235
236/**
237 * snd_ctl_new1 - create a control instance from the template
238 * @ncontrol: the initialization record
239 * @private_data: the private data to set
240 *
241 * Allocates a new struct snd_kcontrol instance and initialize from the given
242 * template. When the access field of ncontrol is 0, it's assumed as
243 * READWRITE access. When the count field is 0, it's assumes as one.
244 *
245 * Return: The pointer of the newly generated instance, or %NULL on failure.
246 */
247struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
248 void *private_data)
249{
250 struct snd_kcontrol *kctl;
251 unsigned int count;
252 unsigned int access;
253 int err;
254
255 if (snd_BUG_ON(!ncontrol || !ncontrol->info))
256 return NULL;
257
258 count = ncontrol->count;
259 if (count == 0)
260 count = 1;
261
262 access = ncontrol->access;
263 if (access == 0)
264 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
265 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
266 SNDRV_CTL_ELEM_ACCESS_VOLATILE |
267 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
268 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE |
269 SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND |
270 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK);
271
272 err = snd_ctl_new(&kctl, count, access, NULL);
273 if (err < 0)
274 return NULL;
275
276 /* The 'numid' member is decided when calling snd_ctl_add(). */
277 kctl->id.iface = ncontrol->iface;
278 kctl->id.device = ncontrol->device;
279 kctl->id.subdevice = ncontrol->subdevice;
280 if (ncontrol->name) {
281 strlcpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.name));
282 if (strcmp(ncontrol->name, kctl->id.name) != 0)
283 pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
284 ncontrol->name, kctl->id.name);
285 }
286 kctl->id.index = ncontrol->index;
287
288 kctl->info = ncontrol->info;
289 kctl->get = ncontrol->get;
290 kctl->put = ncontrol->put;
291 kctl->tlv.p = ncontrol->tlv.p;
292
293 kctl->private_value = ncontrol->private_value;
294 kctl->private_data = private_data;
295
296 return kctl;
297}
298EXPORT_SYMBOL(snd_ctl_new1);
299
300/**
301 * snd_ctl_free_one - release the control instance
302 * @kcontrol: the control instance
303 *
304 * Releases the control instance created via snd_ctl_new()
305 * or snd_ctl_new1().
306 * Don't call this after the control was added to the card.
307 */
308void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
309{
310 if (kcontrol) {
311 if (kcontrol->private_free)
312 kcontrol->private_free(kcontrol);
313 kfree(kcontrol);
314 }
315}
316EXPORT_SYMBOL(snd_ctl_free_one);
317
318static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
319 unsigned int count)
320{
321 struct snd_kcontrol *kctl;
322
323 /* Make sure that the ids assigned to the control do not wrap around */
324 if (card->last_numid >= UINT_MAX - count)
325 card->last_numid = 0;
326
327 list_for_each_entry(kctl, &card->controls, list) {
328 if (kctl->id.numid < card->last_numid + 1 + count &&
329 kctl->id.numid + kctl->count > card->last_numid + 1) {
330 card->last_numid = kctl->id.numid + kctl->count - 1;
331 return true;
332 }
333 }
334 return false;
335}
336
337static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
338{
339 unsigned int iter = 100000;
340
341 while (snd_ctl_remove_numid_conflict(card, count)) {
342 if (--iter == 0) {
343 /* this situation is very unlikely */
344 dev_err(card->dev, "unable to allocate new control numid\n");
345 return -ENOMEM;
346 }
347 }
348 return 0;
349}
350
351/**
352 * snd_ctl_add - add the control instance to the card
353 * @card: the card instance
354 * @kcontrol: the control instance to add
355 *
356 * Adds the control instance created via snd_ctl_new() or
357 * snd_ctl_new1() to the given card. Assigns also an unique
358 * numid used for fast search.
359 *
360 * It frees automatically the control which cannot be added.
361 *
362 * Return: Zero if successful, or a negative error code on failure.
363 *
364 */
365int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
366{
367 struct snd_ctl_elem_id id;
368 unsigned int idx;
369 unsigned int count;
370 int err = -EINVAL;
371
372 if (! kcontrol)
373 return err;
374 if (snd_BUG_ON(!card || !kcontrol->info))
375 goto error;
376 id = kcontrol->id;
377 if (id.index > UINT_MAX - kcontrol->count)
378 goto error;
379
380 down_write(&card->controls_rwsem);
381 if (snd_ctl_find_id(card, &id)) {
382 up_write(&card->controls_rwsem);
383 dev_err(card->dev, "control %i:%i:%i:%s:%i is already present\n",
384 id.iface,
385 id.device,
386 id.subdevice,
387 id.name,
388 id.index);
389 err = -EBUSY;
390 goto error;
391 }
392 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
393 up_write(&card->controls_rwsem);
394 err = -ENOMEM;
395 goto error;
396 }
397 list_add_tail(&kcontrol->list, &card->controls);
398 card->controls_count += kcontrol->count;
399 kcontrol->id.numid = card->last_numid + 1;
400 card->last_numid += kcontrol->count;
401 id = kcontrol->id;
402 count = kcontrol->count;
403 up_write(&card->controls_rwsem);
404 for (idx = 0; idx < count; idx++, id.index++, id.numid++)
405 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
406 return 0;
407
408 error:
409 snd_ctl_free_one(kcontrol);
410 return err;
411}
412EXPORT_SYMBOL(snd_ctl_add);
413
414/**
415 * snd_ctl_replace - replace the control instance of the card
416 * @card: the card instance
417 * @kcontrol: the control instance to replace
418 * @add_on_replace: add the control if not already added
419 *
420 * Replaces the given control. If the given control does not exist
421 * and the add_on_replace flag is set, the control is added. If the
422 * control exists, it is destroyed first.
423 *
424 * It frees automatically the control which cannot be added or replaced.
425 *
426 * Return: Zero if successful, or a negative error code on failure.
427 */
428int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
429 bool add_on_replace)
430{
431 struct snd_ctl_elem_id id;
432 unsigned int count;
433 unsigned int idx;
434 struct snd_kcontrol *old;
435 int ret;
436
437 if (!kcontrol)
438 return -EINVAL;
439 if (snd_BUG_ON(!card || !kcontrol->info)) {
440 ret = -EINVAL;
441 goto error;
442 }
443 id = kcontrol->id;
444 down_write(&card->controls_rwsem);
445 old = snd_ctl_find_id(card, &id);
446 if (!old) {
447 if (add_on_replace)
448 goto add;
449 up_write(&card->controls_rwsem);
450 ret = -EINVAL;
451 goto error;
452 }
453 ret = snd_ctl_remove(card, old);
454 if (ret < 0) {
455 up_write(&card->controls_rwsem);
456 goto error;
457 }
458add:
459 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
460 up_write(&card->controls_rwsem);
461 ret = -ENOMEM;
462 goto error;
463 }
464 list_add_tail(&kcontrol->list, &card->controls);
465 card->controls_count += kcontrol->count;
466 kcontrol->id.numid = card->last_numid + 1;
467 card->last_numid += kcontrol->count;
468 id = kcontrol->id;
469 count = kcontrol->count;
470 up_write(&card->controls_rwsem);
471 for (idx = 0; idx < count; idx++, id.index++, id.numid++)
472 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
473 return 0;
474
475error:
476 snd_ctl_free_one(kcontrol);
477 return ret;
478}
479EXPORT_SYMBOL(snd_ctl_replace);
480
481/**
482 * snd_ctl_remove - remove the control from the card and release it
483 * @card: the card instance
484 * @kcontrol: the control instance to remove
485 *
486 * Removes the control from the card and then releases the instance.
487 * You don't need to call snd_ctl_free_one(). You must be in
488 * the write lock - down_write(&card->controls_rwsem).
489 *
490 * Return: 0 if successful, or a negative error code on failure.
491 */
492int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
493{
494 struct snd_ctl_elem_id id;
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 id = kcontrol->id;
502 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
503 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
504 snd_ctl_free_one(kcontrol);
505 return 0;
506}
507EXPORT_SYMBOL(snd_ctl_remove);
508
509/**
510 * snd_ctl_remove_id - remove the control of the given id and release it
511 * @card: the card instance
512 * @id: the control id to remove
513 *
514 * Finds the control instance with the given id, removes it from the
515 * card list and releases it.
516 *
517 * Return: 0 if successful, or a negative error code on failure.
518 */
519int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
520{
521 struct snd_kcontrol *kctl;
522 int ret;
523
524 down_write(&card->controls_rwsem);
525 kctl = snd_ctl_find_id(card, id);
526 if (kctl == NULL) {
527 up_write(&card->controls_rwsem);
528 return -ENOENT;
529 }
530 ret = snd_ctl_remove(card, kctl);
531 up_write(&card->controls_rwsem);
532 return ret;
533}
534EXPORT_SYMBOL(snd_ctl_remove_id);
535
536/**
537 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
538 * @file: active control handle
539 * @id: the control id to remove
540 *
541 * Finds the control instance with the given id, removes it from the
542 * card list and releases it.
543 *
544 * Return: 0 if successful, or a negative error code on failure.
545 */
546static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
547 struct snd_ctl_elem_id *id)
548{
549 struct snd_card *card = file->card;
550 struct snd_kcontrol *kctl;
551 int idx, ret;
552
553 down_write(&card->controls_rwsem);
554 kctl = snd_ctl_find_id(card, id);
555 if (kctl == NULL) {
556 ret = -ENOENT;
557 goto error;
558 }
559 if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
560 ret = -EINVAL;
561 goto error;
562 }
563 for (idx = 0; idx < kctl->count; idx++)
564 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
565 ret = -EBUSY;
566 goto error;
567 }
568 ret = snd_ctl_remove(card, kctl);
569 if (ret < 0)
570 goto error;
571 card->user_ctl_count--;
572error:
573 up_write(&card->controls_rwsem);
574 return ret;
575}
576
577/**
578 * snd_ctl_activate_id - activate/inactivate the control of the given id
579 * @card: the card instance
580 * @id: the control id to activate/inactivate
581 * @active: non-zero to activate
582 *
583 * Finds the control instance with the given id, and activate or
584 * inactivate the control together with notification, if changed.
585 * The given ID data is filled with full information.
586 *
587 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
588 */
589int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
590 int active)
591{
592 struct snd_kcontrol *kctl;
593 struct snd_kcontrol_volatile *vd;
594 unsigned int index_offset;
595 int ret;
596
597 down_write(&card->controls_rwsem);
598 kctl = snd_ctl_find_id(card, id);
599 if (kctl == NULL) {
600 ret = -ENOENT;
601 goto unlock;
602 }
603 index_offset = snd_ctl_get_ioff(kctl, id);
604 vd = &kctl->vd[index_offset];
605 ret = 0;
606 if (active) {
607 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
608 goto unlock;
609 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
610 } else {
611 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
612 goto unlock;
613 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
614 }
615 snd_ctl_build_ioff(id, kctl, index_offset);
616 ret = 1;
617 unlock:
618 up_write(&card->controls_rwsem);
619 if (ret > 0)
620 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
621 return ret;
622}
623EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
624
625/**
626 * snd_ctl_rename_id - replace the id of a control on the card
627 * @card: the card instance
628 * @src_id: the old id
629 * @dst_id: the new id
630 *
631 * Finds the control with the old id from the card, and replaces the
632 * id with the new one.
633 *
634 * Return: Zero if successful, or a negative error code on failure.
635 */
636int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
637 struct snd_ctl_elem_id *dst_id)
638{
639 struct snd_kcontrol *kctl;
640
641 down_write(&card->controls_rwsem);
642 kctl = snd_ctl_find_id(card, src_id);
643 if (kctl == NULL) {
644 up_write(&card->controls_rwsem);
645 return -ENOENT;
646 }
647 kctl->id = *dst_id;
648 kctl->id.numid = card->last_numid + 1;
649 card->last_numid += kctl->count;
650 up_write(&card->controls_rwsem);
651 return 0;
652}
653EXPORT_SYMBOL(snd_ctl_rename_id);
654
655/**
656 * snd_ctl_find_numid - find the control instance with the given number-id
657 * @card: the card instance
658 * @numid: the number-id to search
659 *
660 * Finds the control instance with the given number-id from the card.
661 *
662 * The caller must down card->controls_rwsem before calling this function
663 * (if the race condition can happen).
664 *
665 * Return: The pointer of the instance if found, or %NULL if not.
666 *
667 */
668struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
669{
670 struct snd_kcontrol *kctl;
671
672 if (snd_BUG_ON(!card || !numid))
673 return NULL;
674 list_for_each_entry(kctl, &card->controls, list) {
675 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
676 return kctl;
677 }
678 return NULL;
679}
680EXPORT_SYMBOL(snd_ctl_find_numid);
681
682/**
683 * snd_ctl_find_id - find the control instance with the given id
684 * @card: the card instance
685 * @id: the id to search
686 *
687 * Finds the control instance with the given id from the card.
688 *
689 * The caller must down card->controls_rwsem before calling this function
690 * (if the race condition can happen).
691 *
692 * Return: The pointer of the instance if found, or %NULL if not.
693 *
694 */
695struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
696 struct snd_ctl_elem_id *id)
697{
698 struct snd_kcontrol *kctl;
699
700 if (snd_BUG_ON(!card || !id))
701 return NULL;
702 if (id->numid != 0)
703 return snd_ctl_find_numid(card, id->numid);
704 list_for_each_entry(kctl, &card->controls, list) {
705 if (kctl->id.iface != id->iface)
706 continue;
707 if (kctl->id.device != id->device)
708 continue;
709 if (kctl->id.subdevice != id->subdevice)
710 continue;
711 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
712 continue;
713 if (kctl->id.index > id->index)
714 continue;
715 if (kctl->id.index + kctl->count <= id->index)
716 continue;
717 return kctl;
718 }
719 return NULL;
720}
721EXPORT_SYMBOL(snd_ctl_find_id);
722
723static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
724 unsigned int cmd, void __user *arg)
725{
726 struct snd_ctl_card_info *info;
727
728 info = kzalloc(sizeof(*info), GFP_KERNEL);
729 if (! info)
730 return -ENOMEM;
731 down_read(&snd_ioctl_rwsem);
732 info->card = card->number;
733 strlcpy(info->id, card->id, sizeof(info->id));
734 strlcpy(info->driver, card->driver, sizeof(info->driver));
735 strlcpy(info->name, card->shortname, sizeof(info->name));
736 strlcpy(info->longname, card->longname, sizeof(info->longname));
737 strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
738 strlcpy(info->components, card->components, sizeof(info->components));
739 up_read(&snd_ioctl_rwsem);
740 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
741 kfree(info);
742 return -EFAULT;
743 }
744 kfree(info);
745 return 0;
746}
747
748static int snd_ctl_elem_list(struct snd_card *card,
749 struct snd_ctl_elem_list __user *_list)
750{
751 struct snd_ctl_elem_list list;
752 struct snd_kcontrol *kctl;
753 struct snd_ctl_elem_id id;
754 unsigned int offset, space, jidx;
755 int err = 0;
756
757 if (copy_from_user(&list, _list, sizeof(list)))
758 return -EFAULT;
759 offset = list.offset;
760 space = list.space;
761
762 down_read(&card->controls_rwsem);
763 list.count = card->controls_count;
764 list.used = 0;
765 if (space > 0) {
766 list_for_each_entry(kctl, &card->controls, list) {
767 if (offset >= kctl->count) {
768 offset -= kctl->count;
769 continue;
770 }
771 for (jidx = offset; jidx < kctl->count; jidx++) {
772 snd_ctl_build_ioff(&id, kctl, jidx);
773 if (copy_to_user(list.pids + list.used, &id,
774 sizeof(id))) {
775 err = -EFAULT;
776 goto out;
777 }
778 list.used++;
779 if (!--space)
780 goto out;
781 }
782 offset = 0;
783 }
784 }
785 out:
786 up_read(&card->controls_rwsem);
787 if (!err && copy_to_user(_list, &list, sizeof(list)))
788 err = -EFAULT;
789 return err;
790}
791
792static bool validate_element_member_dimension(struct snd_ctl_elem_info *info)
793{
794 unsigned int members;
795 unsigned int i;
796
797 if (info->dimen.d[0] == 0)
798 return true;
799
800 members = 1;
801 for (i = 0; i < ARRAY_SIZE(info->dimen.d); ++i) {
802 if (info->dimen.d[i] == 0)
803 break;
804 members *= info->dimen.d[i];
805
806 /*
807 * info->count should be validated in advance, to guarantee
808 * calculation soundness.
809 */
810 if (members > info->count)
811 return false;
812 }
813
814 for (++i; i < ARRAY_SIZE(info->dimen.d); ++i) {
815 if (info->dimen.d[i] > 0)
816 return false;
817 }
818
819 return members == info->count;
820}
821
822static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
823 struct snd_ctl_elem_info *info)
824{
825 struct snd_card *card = ctl->card;
826 struct snd_kcontrol *kctl;
827 struct snd_kcontrol_volatile *vd;
828 unsigned int index_offset;
829 int result;
830
831 down_read(&card->controls_rwsem);
832 kctl = snd_ctl_find_id(card, &info->id);
833 if (kctl == NULL) {
834 up_read(&card->controls_rwsem);
835 return -ENOENT;
836 }
837#ifdef CONFIG_SND_DEBUG
838 info->access = 0;
839#endif
840 result = kctl->info(kctl, info);
841 if (result >= 0) {
842 snd_BUG_ON(info->access);
843 index_offset = snd_ctl_get_ioff(kctl, &info->id);
844 vd = &kctl->vd[index_offset];
845 snd_ctl_build_ioff(&info->id, kctl, index_offset);
846 info->access = vd->access;
847 if (vd->owner) {
848 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
849 if (vd->owner == ctl)
850 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
851 info->owner = pid_vnr(vd->owner->pid);
852 } else {
853 info->owner = -1;
854 }
855 }
856 up_read(&card->controls_rwsem);
857 return result;
858}
859
860static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
861 struct snd_ctl_elem_info __user *_info)
862{
863 struct snd_ctl_elem_info info;
864 int result;
865
866 if (copy_from_user(&info, _info, sizeof(info)))
867 return -EFAULT;
868 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
869 if (result < 0)
870 return result;
871 result = snd_ctl_elem_info(ctl, &info);
872 if (result < 0)
873 return result;
874 if (copy_to_user(_info, &info, sizeof(info)))
875 return -EFAULT;
876 return result;
877}
878
879static int snd_ctl_elem_read(struct snd_card *card,
880 struct snd_ctl_elem_value *control)
881{
882 struct snd_kcontrol *kctl;
883 struct snd_kcontrol_volatile *vd;
884 unsigned int index_offset;
885
886 kctl = snd_ctl_find_id(card, &control->id);
887 if (kctl == NULL)
888 return -ENOENT;
889
890 index_offset = snd_ctl_get_ioff(kctl, &control->id);
891 vd = &kctl->vd[index_offset];
892 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_READ) || kctl->get == NULL)
893 return -EPERM;
894
895 snd_ctl_build_ioff(&control->id, kctl, index_offset);
896 return kctl->get(kctl, control);
897}
898
899static int snd_ctl_elem_read_user(struct snd_card *card,
900 struct snd_ctl_elem_value __user *_control)
901{
902 struct snd_ctl_elem_value *control;
903 int result;
904
905 control = memdup_user(_control, sizeof(*control));
906 if (IS_ERR(control))
907 return PTR_ERR(control);
908
909 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
910 if (result < 0)
911 goto error;
912
913 down_read(&card->controls_rwsem);
914 result = snd_ctl_elem_read(card, control);
915 up_read(&card->controls_rwsem);
916 if (result < 0)
917 goto error;
918
919 if (copy_to_user(_control, control, sizeof(*control)))
920 result = -EFAULT;
921 error:
922 kfree(control);
923 return result;
924}
925
926static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
927 struct snd_ctl_elem_value *control)
928{
929 struct snd_kcontrol *kctl;
930 struct snd_kcontrol_volatile *vd;
931 unsigned int index_offset;
932 int result;
933
934 kctl = snd_ctl_find_id(card, &control->id);
935 if (kctl == NULL)
936 return -ENOENT;
937
938 index_offset = snd_ctl_get_ioff(kctl, &control->id);
939 vd = &kctl->vd[index_offset];
940 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) || kctl->put == NULL ||
941 (file && vd->owner && vd->owner != file)) {
942 return -EPERM;
943 }
944
945 snd_ctl_build_ioff(&control->id, kctl, index_offset);
946 result = kctl->put(kctl, control);
947 if (result < 0)
948 return result;
949
950 if (result > 0) {
951 struct snd_ctl_elem_id id = control->id;
952 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
953 }
954
955 return 0;
956}
957
958static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
959 struct snd_ctl_elem_value __user *_control)
960{
961 struct snd_ctl_elem_value *control;
962 struct snd_card *card;
963 int result;
964
965 control = memdup_user(_control, sizeof(*control));
966 if (IS_ERR(control))
967 return PTR_ERR(control);
968
969 card = file->card;
970 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
971 if (result < 0)
972 goto error;
973
974 down_write(&card->controls_rwsem);
975 result = snd_ctl_elem_write(card, file, control);
976 up_write(&card->controls_rwsem);
977 if (result < 0)
978 goto error;
979
980 if (copy_to_user(_control, control, sizeof(*control)))
981 result = -EFAULT;
982 error:
983 kfree(control);
984 return result;
985}
986
987static int snd_ctl_elem_lock(struct snd_ctl_file *file,
988 struct snd_ctl_elem_id __user *_id)
989{
990 struct snd_card *card = file->card;
991 struct snd_ctl_elem_id id;
992 struct snd_kcontrol *kctl;
993 struct snd_kcontrol_volatile *vd;
994 int result;
995
996 if (copy_from_user(&id, _id, sizeof(id)))
997 return -EFAULT;
998 down_write(&card->controls_rwsem);
999 kctl = snd_ctl_find_id(card, &id);
1000 if (kctl == NULL) {
1001 result = -ENOENT;
1002 } else {
1003 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1004 if (vd->owner != NULL)
1005 result = -EBUSY;
1006 else {
1007 vd->owner = file;
1008 result = 0;
1009 }
1010 }
1011 up_write(&card->controls_rwsem);
1012 return result;
1013}
1014
1015static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
1016 struct snd_ctl_elem_id __user *_id)
1017{
1018 struct snd_card *card = file->card;
1019 struct snd_ctl_elem_id id;
1020 struct snd_kcontrol *kctl;
1021 struct snd_kcontrol_volatile *vd;
1022 int result;
1023
1024 if (copy_from_user(&id, _id, sizeof(id)))
1025 return -EFAULT;
1026 down_write(&card->controls_rwsem);
1027 kctl = snd_ctl_find_id(card, &id);
1028 if (kctl == NULL) {
1029 result = -ENOENT;
1030 } else {
1031 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1032 if (vd->owner == NULL)
1033 result = -EINVAL;
1034 else if (vd->owner != file)
1035 result = -EPERM;
1036 else {
1037 vd->owner = NULL;
1038 result = 0;
1039 }
1040 }
1041 up_write(&card->controls_rwsem);
1042 return result;
1043}
1044
1045struct user_element {
1046 struct snd_ctl_elem_info info;
1047 struct snd_card *card;
1048 char *elem_data; /* element data */
1049 unsigned long elem_data_size; /* size of element data in bytes */
1050 void *tlv_data; /* TLV data */
1051 unsigned long tlv_data_size; /* TLV data size */
1052 void *priv_data; /* private data (like strings for enumerated type) */
1053};
1054
1055static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1056 struct snd_ctl_elem_info *uinfo)
1057{
1058 struct user_element *ue = kcontrol->private_data;
1059 unsigned int offset;
1060
1061 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1062 *uinfo = ue->info;
1063 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1064
1065 return 0;
1066}
1067
1068static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1069 struct snd_ctl_elem_info *uinfo)
1070{
1071 struct user_element *ue = kcontrol->private_data;
1072 const char *names;
1073 unsigned int item;
1074 unsigned int offset;
1075
1076 item = uinfo->value.enumerated.item;
1077
1078 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1079 *uinfo = ue->info;
1080 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1081
1082 item = min(item, uinfo->value.enumerated.items - 1);
1083 uinfo->value.enumerated.item = item;
1084
1085 names = ue->priv_data;
1086 for (; item > 0; --item)
1087 names += strlen(names) + 1;
1088 strcpy(uinfo->value.enumerated.name, names);
1089
1090 return 0;
1091}
1092
1093static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1094 struct snd_ctl_elem_value *ucontrol)
1095{
1096 struct user_element *ue = kcontrol->private_data;
1097 unsigned int size = ue->elem_data_size;
1098 char *src = ue->elem_data +
1099 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1100
1101 memcpy(&ucontrol->value, src, size);
1102 return 0;
1103}
1104
1105static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1106 struct snd_ctl_elem_value *ucontrol)
1107{
1108 int change;
1109 struct user_element *ue = kcontrol->private_data;
1110 unsigned int size = ue->elem_data_size;
1111 char *dst = ue->elem_data +
1112 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1113
1114 change = memcmp(&ucontrol->value, dst, size) != 0;
1115 if (change)
1116 memcpy(dst, &ucontrol->value, size);
1117 return change;
1118}
1119
1120static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
1121 unsigned int size)
1122{
1123 struct user_element *ue = kctl->private_data;
1124 unsigned int *container;
1125 struct snd_ctl_elem_id id;
1126 unsigned int mask = 0;
1127 int i;
1128 int change;
1129
1130 if (size > 1024 * 128) /* sane value */
1131 return -EINVAL;
1132
1133 container = vmemdup_user(buf, size);
1134 if (IS_ERR(container))
1135 return PTR_ERR(container);
1136
1137 change = ue->tlv_data_size != size;
1138 if (!change)
1139 change = memcmp(ue->tlv_data, container, size) != 0;
1140 if (!change) {
1141 kvfree(container);
1142 return 0;
1143 }
1144
1145 if (ue->tlv_data == NULL) {
1146 /* Now TLV data is available. */
1147 for (i = 0; i < kctl->count; ++i)
1148 kctl->vd[i].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
1149 mask = SNDRV_CTL_EVENT_MASK_INFO;
1150 }
1151
1152 kvfree(ue->tlv_data);
1153 ue->tlv_data = container;
1154 ue->tlv_data_size = size;
1155
1156 mask |= SNDRV_CTL_EVENT_MASK_TLV;
1157 for (i = 0; i < kctl->count; ++i) {
1158 snd_ctl_build_ioff(&id, kctl, i);
1159 snd_ctl_notify(ue->card, mask, &id);
1160 }
1161
1162 return change;
1163}
1164
1165static int read_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
1166 unsigned int size)
1167{
1168 struct user_element *ue = kctl->private_data;
1169
1170 if (ue->tlv_data_size == 0 || ue->tlv_data == NULL)
1171 return -ENXIO;
1172
1173 if (size < ue->tlv_data_size)
1174 return -ENOSPC;
1175
1176 if (copy_to_user(buf, ue->tlv_data, ue->tlv_data_size))
1177 return -EFAULT;
1178
1179 return 0;
1180}
1181
1182static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kctl, int op_flag,
1183 unsigned int size, unsigned int __user *buf)
1184{
1185 if (op_flag == SNDRV_CTL_TLV_OP_WRITE)
1186 return replace_user_tlv(kctl, buf, size);
1187 else
1188 return read_user_tlv(kctl, buf, size);
1189}
1190
1191static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1192{
1193 char *names, *p;
1194 size_t buf_len, name_len;
1195 unsigned int i;
1196 const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1197
1198 if (ue->info.value.enumerated.names_length > 64 * 1024)
1199 return -EINVAL;
1200
1201 names = vmemdup_user((const void __user *)user_ptrval,
1202 ue->info.value.enumerated.names_length);
1203 if (IS_ERR(names))
1204 return PTR_ERR(names);
1205
1206 /* check that there are enough valid names */
1207 buf_len = ue->info.value.enumerated.names_length;
1208 p = names;
1209 for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1210 name_len = strnlen(p, buf_len);
1211 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1212 kvfree(names);
1213 return -EINVAL;
1214 }
1215 p += name_len + 1;
1216 buf_len -= name_len + 1;
1217 }
1218
1219 ue->priv_data = names;
1220 ue->info.value.enumerated.names_ptr = 0;
1221
1222 return 0;
1223}
1224
1225static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1226{
1227 struct user_element *ue = kcontrol->private_data;
1228
1229 kvfree(ue->tlv_data);
1230 kvfree(ue->priv_data);
1231 kfree(ue);
1232}
1233
1234static int snd_ctl_elem_add(struct snd_ctl_file *file,
1235 struct snd_ctl_elem_info *info, int replace)
1236{
1237 /* The capacity of struct snd_ctl_elem_value.value.*/
1238 static const unsigned int value_sizes[] = {
1239 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = sizeof(long),
1240 [SNDRV_CTL_ELEM_TYPE_INTEGER] = sizeof(long),
1241 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = sizeof(unsigned int),
1242 [SNDRV_CTL_ELEM_TYPE_BYTES] = sizeof(unsigned char),
1243 [SNDRV_CTL_ELEM_TYPE_IEC958] = sizeof(struct snd_aes_iec958),
1244 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long),
1245 };
1246 static const unsigned int max_value_counts[] = {
1247 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = 128,
1248 [SNDRV_CTL_ELEM_TYPE_INTEGER] = 128,
1249 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = 128,
1250 [SNDRV_CTL_ELEM_TYPE_BYTES] = 512,
1251 [SNDRV_CTL_ELEM_TYPE_IEC958] = 1,
1252 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64,
1253 };
1254 struct snd_card *card = file->card;
1255 struct snd_kcontrol *kctl;
1256 unsigned int count;
1257 unsigned int access;
1258 long private_size;
1259 struct user_element *ue;
1260 unsigned int offset;
1261 int err;
1262
1263 if (!*info->id.name)
1264 return -EINVAL;
1265 if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
1266 return -EINVAL;
1267
1268 /* Delete a control to replace them if needed. */
1269 if (replace) {
1270 info->id.numid = 0;
1271 err = snd_ctl_remove_user_ctl(file, &info->id);
1272 if (err)
1273 return err;
1274 }
1275
1276 /*
1277 * The number of userspace controls are counted control by control,
1278 * not element by element.
1279 */
1280 if (card->user_ctl_count + 1 > MAX_USER_CONTROLS)
1281 return -ENOMEM;
1282
1283 /* Check the number of elements for this userspace control. */
1284 count = info->owner;
1285 if (count == 0)
1286 count = 1;
1287
1288 /* Arrange access permissions if needed. */
1289 access = info->access;
1290 if (access == 0)
1291 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
1292 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
1293 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
1294 SNDRV_CTL_ELEM_ACCESS_TLV_WRITE);
1295
1296 /* In initial state, nothing is available as TLV container. */
1297 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
1298 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1299 access |= SNDRV_CTL_ELEM_ACCESS_USER;
1300
1301 /*
1302 * Check information and calculate the size of data specific to
1303 * this userspace control.
1304 */
1305 if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
1306 info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64)
1307 return -EINVAL;
1308 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED &&
1309 info->value.enumerated.items == 0)
1310 return -EINVAL;
1311 if (info->count < 1 ||
1312 info->count > max_value_counts[info->type])
1313 return -EINVAL;
1314 if (!validate_element_member_dimension(info))
1315 return -EINVAL;
1316 private_size = value_sizes[info->type] * info->count;
1317
1318 /*
1319 * Keep memory object for this userspace control. After passing this
1320 * code block, the instance should be freed by snd_ctl_free_one().
1321 *
1322 * Note that these elements in this control are locked.
1323 */
1324 err = snd_ctl_new(&kctl, count, access, file);
1325 if (err < 0)
1326 return err;
1327 memcpy(&kctl->id, &info->id, sizeof(kctl->id));
1328 kctl->private_data = kzalloc(sizeof(struct user_element) + private_size * count,
1329 GFP_KERNEL);
1330 if (kctl->private_data == NULL) {
1331 kfree(kctl);
1332 return -ENOMEM;
1333 }
1334 kctl->private_free = snd_ctl_elem_user_free;
1335
1336 /* Set private data for this userspace control. */
1337 ue = (struct user_element *)kctl->private_data;
1338 ue->card = card;
1339 ue->info = *info;
1340 ue->info.access = 0;
1341 ue->elem_data = (char *)ue + sizeof(*ue);
1342 ue->elem_data_size = private_size;
1343 if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1344 err = snd_ctl_elem_init_enum_names(ue);
1345 if (err < 0) {
1346 snd_ctl_free_one(kctl);
1347 return err;
1348 }
1349 }
1350
1351 /* Set callback functions. */
1352 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1353 kctl->info = snd_ctl_elem_user_enum_info;
1354 else
1355 kctl->info = snd_ctl_elem_user_info;
1356 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1357 kctl->get = snd_ctl_elem_user_get;
1358 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1359 kctl->put = snd_ctl_elem_user_put;
1360 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
1361 kctl->tlv.c = snd_ctl_elem_user_tlv;
1362
1363 /* This function manage to free the instance on failure. */
1364 err = snd_ctl_add(card, kctl);
1365 if (err < 0)
1366 return err;
1367 offset = snd_ctl_get_ioff(kctl, &info->id);
1368 snd_ctl_build_ioff(&info->id, kctl, offset);
1369 /*
1370 * Here we cannot fill any field for the number of elements added by
1371 * this operation because there're no specific fields. The usage of
1372 * 'owner' field for this purpose may cause any bugs to userspace
1373 * applications because the field originally means PID of a process
1374 * which locks the element.
1375 */
1376
1377 down_write(&card->controls_rwsem);
1378 card->user_ctl_count++;
1379 up_write(&card->controls_rwsem);
1380
1381 return 0;
1382}
1383
1384static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1385 struct snd_ctl_elem_info __user *_info, int replace)
1386{
1387 struct snd_ctl_elem_info info;
1388 int err;
1389
1390 if (copy_from_user(&info, _info, sizeof(info)))
1391 return -EFAULT;
1392 err = snd_ctl_elem_add(file, &info, replace);
1393 if (err < 0)
1394 return err;
1395 if (copy_to_user(_info, &info, sizeof(info))) {
1396 snd_ctl_remove_user_ctl(file, &info.id);
1397 return -EFAULT;
1398 }
1399
1400 return 0;
1401}
1402
1403static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1404 struct snd_ctl_elem_id __user *_id)
1405{
1406 struct snd_ctl_elem_id id;
1407
1408 if (copy_from_user(&id, _id, sizeof(id)))
1409 return -EFAULT;
1410 return snd_ctl_remove_user_ctl(file, &id);
1411}
1412
1413static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1414{
1415 int subscribe;
1416 if (get_user(subscribe, ptr))
1417 return -EFAULT;
1418 if (subscribe < 0) {
1419 subscribe = file->subscribed;
1420 if (put_user(subscribe, ptr))
1421 return -EFAULT;
1422 return 0;
1423 }
1424 if (subscribe) {
1425 file->subscribed = 1;
1426 return 0;
1427 } else if (file->subscribed) {
1428 snd_ctl_empty_read_queue(file);
1429 file->subscribed = 0;
1430 }
1431 return 0;
1432}
1433
1434static int call_tlv_handler(struct snd_ctl_file *file, int op_flag,
1435 struct snd_kcontrol *kctl,
1436 struct snd_ctl_elem_id *id,
1437 unsigned int __user *buf, unsigned int size)
1438{
1439 static const struct {
1440 int op;
1441 int perm;
1442 } pairs[] = {
1443 {SNDRV_CTL_TLV_OP_READ, SNDRV_CTL_ELEM_ACCESS_TLV_READ},
1444 {SNDRV_CTL_TLV_OP_WRITE, SNDRV_CTL_ELEM_ACCESS_TLV_WRITE},
1445 {SNDRV_CTL_TLV_OP_CMD, SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND},
1446 };
1447 struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
1448 int i;
1449
1450 /* Check support of the request for this element. */
1451 for (i = 0; i < ARRAY_SIZE(pairs); ++i) {
1452 if (op_flag == pairs[i].op && (vd->access & pairs[i].perm))
1453 break;
1454 }
1455 if (i == ARRAY_SIZE(pairs))
1456 return -ENXIO;
1457
1458 if (kctl->tlv.c == NULL)
1459 return -ENXIO;
1460
1461 /* When locked, this is unavailable. */
1462 if (vd->owner != NULL && vd->owner != file)
1463 return -EPERM;
1464
1465 return kctl->tlv.c(kctl, op_flag, size, buf);
1466}
1467
1468static int read_tlv_buf(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id,
1469 unsigned int __user *buf, unsigned int size)
1470{
1471 struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
1472 unsigned int len;
1473
1474 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ))
1475 return -ENXIO;
1476
1477 if (kctl->tlv.p == NULL)
1478 return -ENXIO;
1479
1480 len = sizeof(unsigned int) * 2 + kctl->tlv.p[1];
1481 if (size < len)
1482 return -ENOMEM;
1483
1484 if (copy_to_user(buf, kctl->tlv.p, len))
1485 return -EFAULT;
1486
1487 return 0;
1488}
1489
1490static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1491 struct snd_ctl_tlv __user *buf,
1492 int op_flag)
1493{
1494 struct snd_ctl_tlv header;
1495 unsigned int __user *container;
1496 unsigned int container_size;
1497 struct snd_kcontrol *kctl;
1498 struct snd_ctl_elem_id id;
1499 struct snd_kcontrol_volatile *vd;
1500
1501 if (copy_from_user(&header, buf, sizeof(header)))
1502 return -EFAULT;
1503
1504 /* In design of control core, numerical ID starts at 1. */
1505 if (header.numid == 0)
1506 return -EINVAL;
1507
1508 /* At least, container should include type and length fields. */
1509 if (header.length < sizeof(unsigned int) * 2)
1510 return -EINVAL;
1511 container_size = header.length;
1512 container = buf->tlv;
1513
1514 kctl = snd_ctl_find_numid(file->card, header.numid);
1515 if (kctl == NULL)
1516 return -ENOENT;
1517
1518 /* Calculate index of the element in this set. */
1519 id = kctl->id;
1520 snd_ctl_build_ioff(&id, kctl, header.numid - id.numid);
1521 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1522
1523 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1524 return call_tlv_handler(file, op_flag, kctl, &id, container,
1525 container_size);
1526 } else {
1527 if (op_flag == SNDRV_CTL_TLV_OP_READ) {
1528 return read_tlv_buf(kctl, &id, container,
1529 container_size);
1530 }
1531 }
1532
1533 /* Not supported. */
1534 return -ENXIO;
1535}
1536
1537static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1538{
1539 struct snd_ctl_file *ctl;
1540 struct snd_card *card;
1541 struct snd_kctl_ioctl *p;
1542 void __user *argp = (void __user *)arg;
1543 int __user *ip = argp;
1544 int err;
1545
1546 ctl = file->private_data;
1547 card = ctl->card;
1548 if (snd_BUG_ON(!card))
1549 return -ENXIO;
1550 switch (cmd) {
1551 case SNDRV_CTL_IOCTL_PVERSION:
1552 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1553 case SNDRV_CTL_IOCTL_CARD_INFO:
1554 return snd_ctl_card_info(card, ctl, cmd, argp);
1555 case SNDRV_CTL_IOCTL_ELEM_LIST:
1556 return snd_ctl_elem_list(card, argp);
1557 case SNDRV_CTL_IOCTL_ELEM_INFO:
1558 return snd_ctl_elem_info_user(ctl, argp);
1559 case SNDRV_CTL_IOCTL_ELEM_READ:
1560 return snd_ctl_elem_read_user(card, argp);
1561 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1562 return snd_ctl_elem_write_user(ctl, argp);
1563 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1564 return snd_ctl_elem_lock(ctl, argp);
1565 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1566 return snd_ctl_elem_unlock(ctl, argp);
1567 case SNDRV_CTL_IOCTL_ELEM_ADD:
1568 return snd_ctl_elem_add_user(ctl, argp, 0);
1569 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1570 return snd_ctl_elem_add_user(ctl, argp, 1);
1571 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1572 return snd_ctl_elem_remove(ctl, argp);
1573 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1574 return snd_ctl_subscribe_events(ctl, ip);
1575 case SNDRV_CTL_IOCTL_TLV_READ:
1576 down_read(&ctl->card->controls_rwsem);
1577 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
1578 up_read(&ctl->card->controls_rwsem);
1579 return err;
1580 case SNDRV_CTL_IOCTL_TLV_WRITE:
1581 down_write(&ctl->card->controls_rwsem);
1582 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
1583 up_write(&ctl->card->controls_rwsem);
1584 return err;
1585 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1586 down_write(&ctl->card->controls_rwsem);
1587 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
1588 up_write(&ctl->card->controls_rwsem);
1589 return err;
1590 case SNDRV_CTL_IOCTL_POWER:
1591 return -ENOPROTOOPT;
1592 case SNDRV_CTL_IOCTL_POWER_STATE:
1593#ifdef CONFIG_PM
1594 return put_user(card->power_state, ip) ? -EFAULT : 0;
1595#else
1596 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1597#endif
1598 }
1599 down_read(&snd_ioctl_rwsem);
1600 list_for_each_entry(p, &snd_control_ioctls, list) {
1601 err = p->fioctl(card, ctl, cmd, arg);
1602 if (err != -ENOIOCTLCMD) {
1603 up_read(&snd_ioctl_rwsem);
1604 return err;
1605 }
1606 }
1607 up_read(&snd_ioctl_rwsem);
1608 dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
1609 return -ENOTTY;
1610}
1611
1612static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1613 size_t count, loff_t * offset)
1614{
1615 struct snd_ctl_file *ctl;
1616 int err = 0;
1617 ssize_t result = 0;
1618
1619 ctl = file->private_data;
1620 if (snd_BUG_ON(!ctl || !ctl->card))
1621 return -ENXIO;
1622 if (!ctl->subscribed)
1623 return -EBADFD;
1624 if (count < sizeof(struct snd_ctl_event))
1625 return -EINVAL;
1626 spin_lock_irq(&ctl->read_lock);
1627 while (count >= sizeof(struct snd_ctl_event)) {
1628 struct snd_ctl_event ev;
1629 struct snd_kctl_event *kev;
1630 while (list_empty(&ctl->events)) {
1631 wait_queue_entry_t wait;
1632 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1633 err = -EAGAIN;
1634 goto __end_lock;
1635 }
1636 init_waitqueue_entry(&wait, current);
1637 add_wait_queue(&ctl->change_sleep, &wait);
1638 set_current_state(TASK_INTERRUPTIBLE);
1639 spin_unlock_irq(&ctl->read_lock);
1640 schedule();
1641 remove_wait_queue(&ctl->change_sleep, &wait);
1642 if (ctl->card->shutdown)
1643 return -ENODEV;
1644 if (signal_pending(current))
1645 return -ERESTARTSYS;
1646 spin_lock_irq(&ctl->read_lock);
1647 }
1648 kev = snd_kctl_event(ctl->events.next);
1649 ev.type = SNDRV_CTL_EVENT_ELEM;
1650 ev.data.elem.mask = kev->mask;
1651 ev.data.elem.id = kev->id;
1652 list_del(&kev->list);
1653 spin_unlock_irq(&ctl->read_lock);
1654 kfree(kev);
1655 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1656 err = -EFAULT;
1657 goto __end;
1658 }
1659 spin_lock_irq(&ctl->read_lock);
1660 buffer += sizeof(struct snd_ctl_event);
1661 count -= sizeof(struct snd_ctl_event);
1662 result += sizeof(struct snd_ctl_event);
1663 }
1664 __end_lock:
1665 spin_unlock_irq(&ctl->read_lock);
1666 __end:
1667 return result > 0 ? result : err;
1668}
1669
1670static __poll_t snd_ctl_poll(struct file *file, poll_table * wait)
1671{
1672 __poll_t mask;
1673 struct snd_ctl_file *ctl;
1674
1675 ctl = file->private_data;
1676 if (!ctl->subscribed)
1677 return 0;
1678 poll_wait(file, &ctl->change_sleep, wait);
1679
1680 mask = 0;
1681 if (!list_empty(&ctl->events))
1682 mask |= EPOLLIN | EPOLLRDNORM;
1683
1684 return mask;
1685}
1686
1687/*
1688 * register the device-specific control-ioctls.
1689 * called from each device manager like pcm.c, hwdep.c, etc.
1690 */
1691static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1692{
1693 struct snd_kctl_ioctl *pn;
1694
1695 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1696 if (pn == NULL)
1697 return -ENOMEM;
1698 pn->fioctl = fcn;
1699 down_write(&snd_ioctl_rwsem);
1700 list_add_tail(&pn->list, lists);
1701 up_write(&snd_ioctl_rwsem);
1702 return 0;
1703}
1704
1705/**
1706 * snd_ctl_register_ioctl - register the device-specific control-ioctls
1707 * @fcn: ioctl callback function
1708 *
1709 * called from each device manager like pcm.c, hwdep.c, etc.
1710 */
1711int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1712{
1713 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1714}
1715EXPORT_SYMBOL(snd_ctl_register_ioctl);
1716
1717#ifdef CONFIG_COMPAT
1718/**
1719 * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
1720 * control-ioctls
1721 * @fcn: ioctl callback function
1722 */
1723int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1724{
1725 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1726}
1727EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1728#endif
1729
1730/*
1731 * de-register the device-specific control-ioctls.
1732 */
1733static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1734 struct list_head *lists)
1735{
1736 struct snd_kctl_ioctl *p;
1737
1738 if (snd_BUG_ON(!fcn))
1739 return -EINVAL;
1740 down_write(&snd_ioctl_rwsem);
1741 list_for_each_entry(p, lists, list) {
1742 if (p->fioctl == fcn) {
1743 list_del(&p->list);
1744 up_write(&snd_ioctl_rwsem);
1745 kfree(p);
1746 return 0;
1747 }
1748 }
1749 up_write(&snd_ioctl_rwsem);
1750 snd_BUG();
1751 return -EINVAL;
1752}
1753
1754/**
1755 * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
1756 * @fcn: ioctl callback function to unregister
1757 */
1758int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1759{
1760 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1761}
1762EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1763
1764#ifdef CONFIG_COMPAT
1765/**
1766 * snd_ctl_unregister_ioctl - de-register the device-specific compat 32bit
1767 * control-ioctls
1768 * @fcn: ioctl callback function to unregister
1769 */
1770int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1771{
1772 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1773}
1774EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1775#endif
1776
1777static int snd_ctl_fasync(int fd, struct file * file, int on)
1778{
1779 struct snd_ctl_file *ctl;
1780
1781 ctl = file->private_data;
1782 return fasync_helper(fd, file, on, &ctl->fasync);
1783}
1784
1785/* return the preferred subdevice number if already assigned;
1786 * otherwise return -1
1787 */
1788int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
1789{
1790 struct snd_ctl_file *kctl;
1791 int subdevice = -1;
1792
1793 read_lock(&card->ctl_files_rwlock);
1794 list_for_each_entry(kctl, &card->ctl_files, list) {
1795 if (kctl->pid == task_pid(current)) {
1796 subdevice = kctl->preferred_subdevice[type];
1797 if (subdevice != -1)
1798 break;
1799 }
1800 }
1801 read_unlock(&card->ctl_files_rwlock);
1802 return subdevice;
1803}
1804EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);
1805
1806/*
1807 * ioctl32 compat
1808 */
1809#ifdef CONFIG_COMPAT
1810#include "control_compat.c"
1811#else
1812#define snd_ctl_ioctl_compat NULL
1813#endif
1814
1815/*
1816 * INIT PART
1817 */
1818
1819static const struct file_operations snd_ctl_f_ops =
1820{
1821 .owner = THIS_MODULE,
1822 .read = snd_ctl_read,
1823 .open = snd_ctl_open,
1824 .release = snd_ctl_release,
1825 .llseek = no_llseek,
1826 .poll = snd_ctl_poll,
1827 .unlocked_ioctl = snd_ctl_ioctl,
1828 .compat_ioctl = snd_ctl_ioctl_compat,
1829 .fasync = snd_ctl_fasync,
1830};
1831
1832/*
1833 * registration of the control device
1834 */
1835static int snd_ctl_dev_register(struct snd_device *device)
1836{
1837 struct snd_card *card = device->device_data;
1838
1839 return snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1840 &snd_ctl_f_ops, card, &card->ctl_dev);
1841}
1842
1843/*
1844 * disconnection of the control device
1845 */
1846static int snd_ctl_dev_disconnect(struct snd_device *device)
1847{
1848 struct snd_card *card = device->device_data;
1849 struct snd_ctl_file *ctl;
1850
1851 read_lock(&card->ctl_files_rwlock);
1852 list_for_each_entry(ctl, &card->ctl_files, list) {
1853 wake_up(&ctl->change_sleep);
1854 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1855 }
1856 read_unlock(&card->ctl_files_rwlock);
1857
1858 return snd_unregister_device(&card->ctl_dev);
1859}
1860
1861/*
1862 * free all controls
1863 */
1864static int snd_ctl_dev_free(struct snd_device *device)
1865{
1866 struct snd_card *card = device->device_data;
1867 struct snd_kcontrol *control;
1868
1869 down_write(&card->controls_rwsem);
1870 while (!list_empty(&card->controls)) {
1871 control = snd_kcontrol(card->controls.next);
1872 snd_ctl_remove(card, control);
1873 }
1874 up_write(&card->controls_rwsem);
1875 put_device(&card->ctl_dev);
1876 return 0;
1877}
1878
1879/*
1880 * create control core:
1881 * called from init.c
1882 */
1883int snd_ctl_create(struct snd_card *card)
1884{
1885 static struct snd_device_ops ops = {
1886 .dev_free = snd_ctl_dev_free,
1887 .dev_register = snd_ctl_dev_register,
1888 .dev_disconnect = snd_ctl_dev_disconnect,
1889 };
1890 int err;
1891
1892 if (snd_BUG_ON(!card))
1893 return -ENXIO;
1894 if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS))
1895 return -ENXIO;
1896
1897 snd_device_initialize(&card->ctl_dev, card);
1898 dev_set_name(&card->ctl_dev, "controlC%d", card->number);
1899
1900 err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1901 if (err < 0)
1902 put_device(&card->ctl_dev);
1903 return err;
1904}
1905
1906/*
1907 * Frequently used control callbacks/helpers
1908 */
1909
1910/**
1911 * snd_ctl_boolean_mono_info - Helper function for a standard boolean info
1912 * callback with a mono channel
1913 * @kcontrol: the kcontrol instance
1914 * @uinfo: info to store
1915 *
1916 * This is a function that can be used as info callback for a standard
1917 * boolean control with a single mono channel.
1918 */
1919int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1920 struct snd_ctl_elem_info *uinfo)
1921{
1922 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1923 uinfo->count = 1;
1924 uinfo->value.integer.min = 0;
1925 uinfo->value.integer.max = 1;
1926 return 0;
1927}
1928EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1929
1930/**
1931 * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info
1932 * callback with stereo two channels
1933 * @kcontrol: the kcontrol instance
1934 * @uinfo: info to store
1935 *
1936 * This is a function that can be used as info callback for a standard
1937 * boolean control with stereo two channels.
1938 */
1939int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1940 struct snd_ctl_elem_info *uinfo)
1941{
1942 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1943 uinfo->count = 2;
1944 uinfo->value.integer.min = 0;
1945 uinfo->value.integer.max = 1;
1946 return 0;
1947}
1948EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1949
1950/**
1951 * snd_ctl_enum_info - fills the info structure for an enumerated control
1952 * @info: the structure to be filled
1953 * @channels: the number of the control's channels; often one
1954 * @items: the number of control values; also the size of @names
1955 * @names: an array containing the names of all control values
1956 *
1957 * Sets all required fields in @info to their appropriate values.
1958 * If the control's accessibility is not the default (readable and writable),
1959 * the caller has to fill @info->access.
1960 *
1961 * Return: Zero.
1962 */
1963int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1964 unsigned int items, const char *const names[])
1965{
1966 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1967 info->count = channels;
1968 info->value.enumerated.items = items;
1969 if (!items)
1970 return 0;
1971 if (info->value.enumerated.item >= items)
1972 info->value.enumerated.item = items - 1;
1973 WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
1974 "ALSA: too long item name '%s'\n",
1975 names[info->value.enumerated.item]);
1976 strlcpy(info->value.enumerated.name,
1977 names[info->value.enumerated.item],
1978 sizeof(info->value.enumerated.name));
1979 return 0;
1980}
1981EXPORT_SYMBOL(snd_ctl_enum_info);