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