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