control.c 50.3 KB
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/*
 *  Routines for driver control interface
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 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
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 *
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#include <linux/threads.h>
#include <linux/interrupt.h>
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#include <linux/module.h>
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#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/time.h>
#include <sound/core.h>
#include <sound/minors.h>
#include <sound/info.h>
#include <sound/control.h>

/* max number of user-defined controls */
#define MAX_USER_CONTROLS	32
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#define MAX_CONTROL_COUNT	1028
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struct snd_kctl_ioctl {
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	struct list_head list;		/* list of all ioctls */
	snd_kctl_ioctl_func_t fioctl;
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};
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static DECLARE_RWSEM(snd_ioctl_rwsem);
static LIST_HEAD(snd_control_ioctls);
#ifdef CONFIG_COMPAT
static LIST_HEAD(snd_control_compat_ioctls);
#endif

static int snd_ctl_open(struct inode *inode, struct file *file)
{
	unsigned long flags;
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	struct snd_card *card;
	struct snd_ctl_file *ctl;
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	int i, err;
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	err = nonseekable_open(inode, file);
	if (err < 0)
		return err;

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	card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
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	if (!card) {
		err = -ENODEV;
		goto __error1;
	}
	err = snd_card_file_add(card, file);
	if (err < 0) {
		err = -ENODEV;
		goto __error1;
	}
	if (!try_module_get(card->module)) {
		err = -EFAULT;
		goto __error2;
	}
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	ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
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	if (ctl == NULL) {
		err = -ENOMEM;
		goto __error;
	}
	INIT_LIST_HEAD(&ctl->events);
	init_waitqueue_head(&ctl->change_sleep);
	spin_lock_init(&ctl->read_lock);
	ctl->card = card;
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	for (i = 0; i < SND_CTL_SUBDEV_ITEMS; i++)
		ctl->preferred_subdevice[i] = -1;
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	ctl->pid = get_pid(task_pid(current));
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	file->private_data = ctl;
	write_lock_irqsave(&card->ctl_files_rwlock, flags);
	list_add_tail(&ctl->list, &card->ctl_files);
	write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
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	snd_card_unref(card);
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	return 0;

      __error:
	module_put(card->module);
      __error2:
	snd_card_file_remove(card, file);
      __error1:
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	if (card)
		snd_card_unref(card);
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      	return err;
}

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static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
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{
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	unsigned long flags;
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	struct snd_kctl_event *cread;
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	spin_lock_irqsave(&ctl->read_lock, flags);
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	while (!list_empty(&ctl->events)) {
		cread = snd_kctl_event(ctl->events.next);
		list_del(&cread->list);
		kfree(cread);
	}
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	spin_unlock_irqrestore(&ctl->read_lock, flags);
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}

static int snd_ctl_release(struct inode *inode, struct file *file)
{
	unsigned long flags;
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	struct snd_card *card;
	struct snd_ctl_file *ctl;
	struct snd_kcontrol *control;
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	unsigned int idx;

	ctl = file->private_data;
	file->private_data = NULL;
	card = ctl->card;
	write_lock_irqsave(&card->ctl_files_rwlock, flags);
	list_del(&ctl->list);
	write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
	down_write(&card->controls_rwsem);
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	list_for_each_entry(control, &card->controls, list)
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		for (idx = 0; idx < control->count; idx++)
			if (control->vd[idx].owner == ctl)
				control->vd[idx].owner = NULL;
	up_write(&card->controls_rwsem);
	snd_ctl_empty_read_queue(ctl);
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	put_pid(ctl->pid);
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	kfree(ctl);
	module_put(card->module);
	snd_card_file_remove(card, file);
	return 0;
}

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/**
 * snd_ctl_notify - Send notification to user-space for a control change
 * @card: the card to send notification
 * @mask: the event mask, SNDRV_CTL_EVENT_*
 * @id: the ctl element id to send notification
 *
 * This function adds an event record with the given id and mask, appends
 * to the list and wakes up the user-space for notification.  This can be
 * called in the atomic context.
 */
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void snd_ctl_notify(struct snd_card *card, unsigned int mask,
		    struct snd_ctl_elem_id *id)
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{
	unsigned long flags;
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	struct snd_ctl_file *ctl;
	struct snd_kctl_event *ev;
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	if (snd_BUG_ON(!card || !id))
		return;
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	if (card->shutdown)
		return;
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	read_lock(&card->ctl_files_rwlock);
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#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
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	card->mixer_oss_change_count++;
#endif
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	list_for_each_entry(ctl, &card->ctl_files, list) {
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		if (!ctl->subscribed)
			continue;
		spin_lock_irqsave(&ctl->read_lock, flags);
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		list_for_each_entry(ev, &ctl->events, list) {
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			if (ev->id.numid == id->numid) {
				ev->mask |= mask;
				goto _found;
			}
		}
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		ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
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		if (ev) {
			ev->id = *id;
			ev->mask = mask;
			list_add_tail(&ev->list, &ctl->events);
		} else {
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			dev_err(card->dev, "No memory available to allocate event\n");
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		}
	_found:
		wake_up(&ctl->change_sleep);
		spin_unlock_irqrestore(&ctl->read_lock, flags);
		kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
	}
	read_unlock(&card->ctl_files_rwlock);
}
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EXPORT_SYMBOL(snd_ctl_notify);

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/**
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 * snd_ctl_new - create a new control instance with some elements
 * @kctl: the pointer to store new control instance
 * @count: the number of elements in this control
 * @access: the default access flags for elements in this control
 * @file: given when locking these elements
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 *
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 * Allocates a memory object for a new control instance. The instance has
 * elements as many as the given number (@count). Each element has given
 * access permissions (@access). Each element is locked when @file is given.
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 *
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 * Return: 0 on success, error code on failure
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 */
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static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count,
		       unsigned int access, struct snd_ctl_file *file)
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{
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	unsigned int size;
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	unsigned int idx;
	
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	if (count == 0 || count > MAX_CONTROL_COUNT)
		return -EINVAL;
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	size  = sizeof(struct snd_kcontrol);
	size += sizeof(struct snd_kcontrol_volatile) * count;
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	*kctl = kzalloc(size, GFP_KERNEL);
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	if (!*kctl)
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		return -ENOMEM;

	for (idx = 0; idx < count; idx++) {
		(*kctl)->vd[idx].access = access;
		(*kctl)->vd[idx].owner = file;
	}
	(*kctl)->count = count;

	return 0;
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}

/**
 * snd_ctl_new1 - create a control instance from the template
 * @ncontrol: the initialization record
 * @private_data: the private data to set
 *
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 * Allocates a new struct snd_kcontrol instance and initialize from the given 
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 * template.  When the access field of ncontrol is 0, it's assumed as
 * READWRITE access. When the count field is 0, it's assumes as one.
 *
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 * Return: The pointer of the newly generated instance, or %NULL on failure.
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 */
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struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
				  void *private_data)
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{
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	struct snd_kcontrol *kctl;
	unsigned int count;
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	unsigned int access;
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	int err;
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	if (snd_BUG_ON(!ncontrol || !ncontrol->info))
		return NULL;
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	count = ncontrol->count;
	if (count == 0)
		count = 1;

	access = ncontrol->access;
	if (access == 0)
		access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
	access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
		   SNDRV_CTL_ELEM_ACCESS_VOLATILE |
		   SNDRV_CTL_ELEM_ACCESS_INACTIVE |
		   SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE |
		   SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND |
		   SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK);

	err = snd_ctl_new(&kctl, count, access, NULL);
	if (err < 0)
		return NULL;

	/* The 'numid' member is decided when calling snd_ctl_add(). */
	kctl->id.iface = ncontrol->iface;
	kctl->id.device = ncontrol->device;
	kctl->id.subdevice = ncontrol->subdevice;
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	if (ncontrol->name) {
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		strlcpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.name));
		if (strcmp(ncontrol->name, kctl->id.name) != 0)
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			pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
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				ncontrol->name, kctl->id.name);
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	}
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	kctl->id.index = ncontrol->index;

	kctl->info = ncontrol->info;
	kctl->get = ncontrol->get;
	kctl->put = ncontrol->put;
	kctl->tlv.p = ncontrol->tlv.p;

	kctl->private_value = ncontrol->private_value;
	kctl->private_data = private_data;

	return kctl;
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}
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EXPORT_SYMBOL(snd_ctl_new1);

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/**
 * snd_ctl_free_one - release the control instance
 * @kcontrol: the control instance
 *
 * Releases the control instance created via snd_ctl_new()
 * or snd_ctl_new1().
 * Don't call this after the control was added to the card.
 */
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void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
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{
	if (kcontrol) {
		if (kcontrol->private_free)
			kcontrol->private_free(kcontrol);
		kfree(kcontrol);
	}
}
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EXPORT_SYMBOL(snd_ctl_free_one);

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static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
					  unsigned int count)
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{
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	struct snd_kcontrol *kctl;
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	/* Make sure that the ids assigned to the control do not wrap around */
	if (card->last_numid >= UINT_MAX - count)
		card->last_numid = 0;

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	list_for_each_entry(kctl, &card->controls, list) {
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		if (kctl->id.numid < card->last_numid + 1 + count &&
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		    kctl->id.numid + kctl->count > card->last_numid + 1) {
		    	card->last_numid = kctl->id.numid + kctl->count - 1;
			return true;
		}
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	}
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	return false;
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}

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static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
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{
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	unsigned int iter = 100000;
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	while (snd_ctl_remove_numid_conflict(card, count)) {
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		if (--iter == 0) {
			/* this situation is very unlikely */
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			dev_err(card->dev, "unable to allocate new control numid\n");
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			return -ENOMEM;
		}
	}
	return 0;
}

/**
 * snd_ctl_add - add the control instance to the card
 * @card: the card instance
 * @kcontrol: the control instance to add
 *
 * Adds the control instance created via snd_ctl_new() or
 * snd_ctl_new1() to the given card. Assigns also an unique
 * numid used for fast search.
 *
 * It frees automatically the control which cannot be added.
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 *
 * Return: Zero if successful, or a negative error code on failure.
 *
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 */
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int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
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{
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	struct snd_ctl_elem_id id;
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	unsigned int idx;
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	unsigned int count;
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	int err = -EINVAL;
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	if (! kcontrol)
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		return err;
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	if (snd_BUG_ON(!card || !kcontrol->info))
		goto error;
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	id = kcontrol->id;
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	if (id.index > UINT_MAX - kcontrol->count)
		goto error;

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	down_write(&card->controls_rwsem);
	if (snd_ctl_find_id(card, &id)) {
		up_write(&card->controls_rwsem);
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		dev_err(card->dev, "control %i:%i:%i:%s:%i is already present\n",
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					id.iface,
					id.device,
					id.subdevice,
					id.name,
					id.index);
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		err = -EBUSY;
		goto error;
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	}
	if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
		up_write(&card->controls_rwsem);
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		err = -ENOMEM;
		goto error;
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	}
	list_add_tail(&kcontrol->list, &card->controls);
	card->controls_count += kcontrol->count;
	kcontrol->id.numid = card->last_numid + 1;
	card->last_numid += kcontrol->count;
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	id = kcontrol->id;
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	count = kcontrol->count;
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	up_write(&card->controls_rwsem);
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	for (idx = 0; idx < count; idx++, id.index++, id.numid++)
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		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
	return 0;
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 error:
	snd_ctl_free_one(kcontrol);
	return err;
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}
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EXPORT_SYMBOL(snd_ctl_add);

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/**
 * snd_ctl_replace - replace the control instance of the card
 * @card: the card instance
 * @kcontrol: the control instance to replace
 * @add_on_replace: add the control if not already added
 *
 * Replaces the given control.  If the given control does not exist
 * and the add_on_replace flag is set, the control is added.  If the
 * control exists, it is destroyed first.
 *
 * It frees automatically the control which cannot be added or replaced.
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 *
 * Return: Zero if successful, or a negative error code on failure.
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 */
int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
		    bool add_on_replace)
{
	struct snd_ctl_elem_id id;
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	unsigned int count;
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	unsigned int idx;
	struct snd_kcontrol *old;
	int ret;

	if (!kcontrol)
		return -EINVAL;
	if (snd_BUG_ON(!card || !kcontrol->info)) {
		ret = -EINVAL;
		goto error;
	}
	id = kcontrol->id;
	down_write(&card->controls_rwsem);
	old = snd_ctl_find_id(card, &id);
	if (!old) {
		if (add_on_replace)
			goto add;
		up_write(&card->controls_rwsem);
		ret = -EINVAL;
		goto error;
	}
	ret = snd_ctl_remove(card, old);
	if (ret < 0) {
		up_write(&card->controls_rwsem);
		goto error;
	}
add:
	if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
		up_write(&card->controls_rwsem);
		ret = -ENOMEM;
		goto error;
	}
	list_add_tail(&kcontrol->list, &card->controls);
	card->controls_count += kcontrol->count;
	kcontrol->id.numid = card->last_numid + 1;
	card->last_numid += kcontrol->count;
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	id = kcontrol->id;
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	count = kcontrol->count;
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	up_write(&card->controls_rwsem);
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	for (idx = 0; idx < count; idx++, id.index++, id.numid++)
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		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
	return 0;

error:
	snd_ctl_free_one(kcontrol);
	return ret;
}
EXPORT_SYMBOL(snd_ctl_replace);

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/**
 * snd_ctl_remove - remove the control from the card and release it
 * @card: the card instance
 * @kcontrol: the control instance to remove
 *
 * Removes the control from the card and then releases the instance.
 * You don't need to call snd_ctl_free_one(). You must be in
 * the write lock - down_write(&card->controls_rwsem).
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 *
 * Return: 0 if successful, or a negative error code on failure.
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 */
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int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
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{
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	struct snd_ctl_elem_id id;
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	unsigned int idx;

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	if (snd_BUG_ON(!card || !kcontrol))
		return -EINVAL;
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	list_del(&kcontrol->list);
	card->controls_count -= kcontrol->count;
	id = kcontrol->id;
	for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
	snd_ctl_free_one(kcontrol);
	return 0;
}
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EXPORT_SYMBOL(snd_ctl_remove);

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/**
 * snd_ctl_remove_id - remove the control of the given id and release it
 * @card: the card instance
 * @id: the control id to remove
 *
 * Finds the control instance with the given id, removes it from the
 * card list and releases it.
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 *
 * Return: 0 if successful, or a negative error code on failure.
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 */
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int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
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{
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	struct snd_kcontrol *kctl;
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	int ret;

	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, id);
	if (kctl == NULL) {
		up_write(&card->controls_rwsem);
		return -ENOENT;
	}
	ret = snd_ctl_remove(card, kctl);
	up_write(&card->controls_rwsem);
	return ret;
}
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EXPORT_SYMBOL(snd_ctl_remove_id);

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/**
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 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
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 * @file: active control handle
 * @id: the control id to remove
 *
 * Finds the control instance with the given id, removes it from the
 * card list and releases it.
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 *
 * Return: 0 if successful, or a negative error code on failure.
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 */
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static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
				   struct snd_ctl_elem_id *id)
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{
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	struct snd_card *card = file->card;
	struct snd_kcontrol *kctl;
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	int idx, ret;

	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, id);
	if (kctl == NULL) {
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		ret = -ENOENT;
		goto error;
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	}
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	if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
		ret = -EINVAL;
		goto error;
	}
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	for (idx = 0; idx < kctl->count; idx++)
		if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
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			ret = -EBUSY;
			goto error;
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		}
	ret = snd_ctl_remove(card, kctl);
567 568 569
	if (ret < 0)
		goto error;
	card->user_ctl_count--;
570
error:
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	up_write(&card->controls_rwsem);
	return ret;
}

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/**
 * snd_ctl_activate_id - activate/inactivate the control of the given id
 * @card: the card instance
 * @id: the control id to activate/inactivate
 * @active: non-zero to activate
 *
 * Finds the control instance with the given id, and activate or
 * inactivate the control together with notification, if changed.
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 * The given ID data is filled with full information.
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 *
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 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
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 */
int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
			int active)
{
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
	unsigned int index_offset;
	int ret;

	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, id);
	if (kctl == NULL) {
		ret = -ENOENT;
		goto unlock;
	}
601
	index_offset = snd_ctl_get_ioff(kctl, id);
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	vd = &kctl->vd[index_offset];
	ret = 0;
	if (active) {
		if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
			goto unlock;
		vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
	} else {
		if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
			goto unlock;
		vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
	}
613
	snd_ctl_build_ioff(id, kctl, index_offset);
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	ret = 1;
 unlock:
	up_write(&card->controls_rwsem);
	if (ret > 0)
		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
	return ret;
}
EXPORT_SYMBOL_GPL(snd_ctl_activate_id);

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/**
 * snd_ctl_rename_id - replace the id of a control on the card
 * @card: the card instance
 * @src_id: the old id
 * @dst_id: the new id
 *
 * Finds the control with the old id from the card, and replaces the
 * id with the new one.
 *
632
 * Return: Zero if successful, or a negative error code on failure.
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 */
634 635
int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
		      struct snd_ctl_elem_id *dst_id)
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{
637
	struct snd_kcontrol *kctl;
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	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, src_id);
	if (kctl == NULL) {
		up_write(&card->controls_rwsem);
		return -ENOENT;
	}
	kctl->id = *dst_id;
	kctl->id.numid = card->last_numid + 1;
	card->last_numid += kctl->count;
	up_write(&card->controls_rwsem);
	return 0;
}
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EXPORT_SYMBOL(snd_ctl_rename_id);

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/**
 * snd_ctl_find_numid - find the control instance with the given number-id
 * @card: the card instance
 * @numid: the number-id to search
 *
 * Finds the control instance with the given number-id from the card.
 *
 * The caller must down card->controls_rwsem before calling this function
 * (if the race condition can happen).
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 *
 * Return: The pointer of the instance if found, or %NULL if not.
 *
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 */
666
struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
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{
668
	struct snd_kcontrol *kctl;
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	if (snd_BUG_ON(!card || !numid))
		return NULL;
672
	list_for_each_entry(kctl, &card->controls, list) {
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		if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
			return kctl;
	}
	return NULL;
}
678 679
EXPORT_SYMBOL(snd_ctl_find_numid);

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/**
 * snd_ctl_find_id - find the control instance with the given id
 * @card: the card instance
 * @id: the id to search
 *
 * Finds the control instance with the given id from the card.
 *
 * The caller must down card->controls_rwsem before calling this function
 * (if the race condition can happen).
689 690 691
 *
 * Return: The pointer of the instance if found, or %NULL if not.
 *
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 */
693 694
struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
				     struct snd_ctl_elem_id *id)
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{
696
	struct snd_kcontrol *kctl;
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698 699
	if (snd_BUG_ON(!card || !id))
		return NULL;
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	if (id->numid != 0)
		return snd_ctl_find_numid(card, id->numid);
702
	list_for_each_entry(kctl, &card->controls, list) {
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		if (kctl->id.iface != id->iface)
			continue;
		if (kctl->id.device != id->device)
			continue;
		if (kctl->id.subdevice != id->subdevice)
			continue;
		if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
			continue;
		if (kctl->id.index > id->index)
			continue;
		if (kctl->id.index + kctl->count <= id->index)
			continue;
		return kctl;
	}
	return NULL;
}
719 720
EXPORT_SYMBOL(snd_ctl_find_id);

721
static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
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			     unsigned int cmd, void __user *arg)
{
724
	struct snd_ctl_card_info *info;
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726
	info = kzalloc(sizeof(*info), GFP_KERNEL);
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	if (! info)
		return -ENOMEM;
	down_read(&snd_ioctl_rwsem);
	info->card = card->number;
	strlcpy(info->id, card->id, sizeof(info->id));
	strlcpy(info->driver, card->driver, sizeof(info->driver));
	strlcpy(info->name, card->shortname, sizeof(info->name));
	strlcpy(info->longname, card->longname, sizeof(info->longname));
	strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
	strlcpy(info->components, card->components, sizeof(info->components));
	up_read(&snd_ioctl_rwsem);
738
	if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
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		kfree(info);
		return -EFAULT;
	}
	kfree(info);
	return 0;
}

746 747
static int snd_ctl_elem_list(struct snd_card *card,
			     struct snd_ctl_elem_list __user *_list)
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{
	struct list_head *plist;
750 751 752
	struct snd_ctl_elem_list list;
	struct snd_kcontrol *kctl;
	struct snd_ctl_elem_id *dst, *id;
753
	unsigned int offset, space, jidx;
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	if (copy_from_user(&list, _list, sizeof(list)))
		return -EFAULT;
	offset = list.offset;
	space = list.space;
	/* try limit maximum space */
	if (space > 16384)
		return -ENOMEM;
	if (space > 0) {
		/* allocate temporary buffer for atomic operation */
764
		dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
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		if (dst == NULL)
			return -ENOMEM;
		down_read(&card->controls_rwsem);
		list.count = card->controls_count;
		plist = card->controls.next;
		while (plist != &card->controls) {
			if (offset == 0)
				break;
			kctl = snd_kcontrol(plist);
			if (offset < kctl->count)
				break;
			offset -= kctl->count;
			plist = plist->next;
		}
		list.used = 0;
		id = dst;
		while (space > 0 && plist != &card->controls) {
			kctl = snd_kcontrol(plist);
			for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
				snd_ctl_build_ioff(id, kctl, jidx);
				id++;
				space--;
				list.used++;
			}
			plist = plist->next;
			offset = 0;
		}
		up_read(&card->controls_rwsem);
793 794 795
		if (list.used > 0 &&
		    copy_to_user(list.pids, dst,
				 list.used * sizeof(struct snd_ctl_elem_id))) {
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			vfree(dst);
			return -EFAULT;
		}
		vfree(dst);
	} else {
		down_read(&card->controls_rwsem);
		list.count = card->controls_count;
		up_read(&card->controls_rwsem);
	}
	if (copy_to_user(_list, &list, sizeof(list)))
		return -EFAULT;
	return 0;
}

810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839
static bool validate_element_member_dimension(struct snd_ctl_elem_info *info)
{
	unsigned int members;
	unsigned int i;

	if (info->dimen.d[0] == 0)
		return true;

	members = 1;
	for (i = 0; i < ARRAY_SIZE(info->dimen.d); ++i) {
		if (info->dimen.d[i] == 0)
			break;
		members *= info->dimen.d[i];

		/*
		 * info->count should be validated in advance, to guarantee
		 * calculation soundness.
		 */
		if (members > info->count)
			return false;
	}

	for (++i; i < ARRAY_SIZE(info->dimen.d); ++i) {
		if (info->dimen.d[i] > 0)
			return false;
	}

	return members == info->count;
}

840 841
static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
			     struct snd_ctl_elem_info *info)
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{
843 844 845
	struct snd_card *card = ctl->card;
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
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	unsigned int index_offset;
	int result;
	
	down_read(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &info->id);
	if (kctl == NULL) {
		up_read(&card->controls_rwsem);
		return -ENOENT;
	}
#ifdef CONFIG_SND_DEBUG
	info->access = 0;
#endif
	result = kctl->info(kctl, info);
	if (result >= 0) {
860
		snd_BUG_ON(info->access);
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		index_offset = snd_ctl_get_ioff(kctl, &info->id);
		vd = &kctl->vd[index_offset];
		snd_ctl_build_ioff(&info->id, kctl, index_offset);
		info->access = vd->access;
		if (vd->owner) {
			info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
			if (vd->owner == ctl)
				info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
869
			info->owner = pid_vnr(vd->owner->pid);
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		} else {
			info->owner = -1;
		}
	}
	up_read(&card->controls_rwsem);
	return result;
}

878 879
static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
				  struct snd_ctl_elem_info __user *_info)
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{
881
	struct snd_ctl_elem_info info;
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	int result;

	if (copy_from_user(&info, _info, sizeof(info)))
		return -EFAULT;
886
	snd_power_lock(ctl->card);
887
	result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
888 889 890
	if (result >= 0)
		result = snd_ctl_elem_info(ctl, &info);
	snd_power_unlock(ctl->card);
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	if (result >= 0)
		if (copy_to_user(_info, &info, sizeof(info)))
			return -EFAULT;
	return result;
}

897 898
static int snd_ctl_elem_read(struct snd_card *card,
			     struct snd_ctl_elem_value *control)
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{
900 901
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
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	unsigned int index_offset;
903
	int result;
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	down_read(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &control->id);
	if (kctl == NULL) {
		result = -ENOENT;
	} else {
		index_offset = snd_ctl_get_ioff(kctl, &control->id);
		vd = &kctl->vd[index_offset];
912 913 914 915 916 917
		if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
		    kctl->get != NULL) {
			snd_ctl_build_ioff(&control->id, kctl, index_offset);
			result = kctl->get(kctl, control);
		} else
			result = -EPERM;
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	}
	up_read(&card->controls_rwsem);
	return result;
}

923 924
static int snd_ctl_elem_read_user(struct snd_card *card,
				  struct snd_ctl_elem_value __user *_control)
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{
926
	struct snd_ctl_elem_value *control;
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	int result;
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	control = memdup_user(_control, sizeof(*control));
	if (IS_ERR(control))
		return PTR_ERR(control);

933
	snd_power_lock(card);
934
	result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
935 936 937
	if (result >= 0)
		result = snd_ctl_elem_read(card, control);
	snd_power_unlock(card);
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	if (result >= 0)
		if (copy_to_user(_control, control, sizeof(*control)))
			result = -EFAULT;
	kfree(control);
	return result;
}

945 946
static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
			      struct snd_ctl_elem_value *control)
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{
948 949
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
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	unsigned int index_offset;
951
	int result;
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	down_read(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &control->id);
	if (kctl == NULL) {
		result = -ENOENT;
	} else {
		index_offset = snd_ctl_get_ioff(kctl, &control->id);
		vd = &kctl->vd[index_offset];
960 961 962 963
		if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
		    kctl->put == NULL ||
		    (file && vd->owner && vd->owner != file)) {
			result = -EPERM;
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		} else {
965 966 967 968
			snd_ctl_build_ioff(&control->id, kctl, index_offset);
			result = kctl->put(kctl, control);
		}
		if (result > 0) {
969
			struct snd_ctl_elem_id id = control->id;
970
			up_read(&card->controls_rwsem);
971
			snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
972
			return 0;
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		}
	}
	up_read(&card->controls_rwsem);
	return result;
}

979 980
static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
				   struct snd_ctl_elem_value __user *_control)
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{
982
	struct snd_ctl_elem_value *control;
983
	struct snd_card *card;
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	int result;

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	control = memdup_user(_control, sizeof(*control));
	if (IS_ERR(control))
		return PTR_ERR(control);

990 991
	card = file->card;
	snd_power_lock(card);
992
	result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
993 994 995
	if (result >= 0)
		result = snd_ctl_elem_write(card, file, control);
	snd_power_unlock(card);
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	if (result >= 0)
		if (copy_to_user(_control, control, sizeof(*control)))
			result = -EFAULT;
	kfree(control);
	return result;
}

1003 1004
static int snd_ctl_elem_lock(struct snd_ctl_file *file,
			     struct snd_ctl_elem_id __user *_id)
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{
1006 1007 1008 1009
	struct snd_card *card = file->card;
	struct snd_ctl_elem_id id;
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
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	int result;
	
	if (copy_from_user(&id, _id, sizeof(id)))
		return -EFAULT;
	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &id);
	if (kctl == NULL) {
		result = -ENOENT;
	} else {
		vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
		if (vd->owner != NULL)
			result = -EBUSY;
		else {
			vd->owner = file;
			result = 0;
		}
	}
	up_write(&card->controls_rwsem);
	return result;
}

1031 1032
static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
			       struct snd_ctl_elem_id __user *_id)
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{
1034 1035 1036 1037
	struct snd_card *card = file->card;
	struct snd_ctl_elem_id id;
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
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	int result;
	
	if (copy_from_user(&id, _id, sizeof(id)))
		return -EFAULT;
	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &id);
	if (kctl == NULL) {
		result = -ENOENT;
	} else {
		vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
		if (vd->owner == NULL)
			result = -EINVAL;
		else if (vd->owner != file)
			result = -EPERM;
		else {
			vd->owner = NULL;
			result = 0;
		}
	}
	up_write(&card->controls_rwsem);
	return result;
}

struct user_element {
1062
	struct snd_ctl_elem_info info;
1063
	struct snd_card *card;
1064
	char *elem_data;		/* element data */
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	unsigned long elem_data_size;	/* size of element data in bytes */
1066 1067
	void *tlv_data;			/* TLV data */
	unsigned long tlv_data_size;	/* TLV data size */
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	void *priv_data;		/* private data (like strings for enumerated type) */
};

1071 1072
static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
				  struct snd_ctl_elem_info *uinfo)
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{
	struct user_element *ue = kcontrol->private_data;
1075
	unsigned int offset;
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1077
	offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
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	*uinfo = ue->info;
1079 1080
	snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);

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	return 0;
}

1084 1085 1086 1087 1088 1089
static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
				       struct snd_ctl_elem_info *uinfo)
{
	struct user_element *ue = kcontrol->private_data;
	const char *names;
	unsigned int item;
1090
	unsigned int offset;
1091 1092 1093

	item = uinfo->value.enumerated.item;

1094
	offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1095
	*uinfo = ue->info;
1096
	snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108

	item = min(item, uinfo->value.enumerated.items - 1);
	uinfo->value.enumerated.item = item;

	names = ue->priv_data;
	for (; item > 0; --item)
		names += strlen(names) + 1;
	strcpy(uinfo->value.enumerated.name, names);

	return 0;
}

1109 1110
static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
				 struct snd_ctl_elem_value *ucontrol)
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1111 1112
{
	struct user_element *ue = kcontrol->private_data;
1113 1114 1115
	unsigned int size = ue->elem_data_size;
	char *src = ue->elem_data +
			snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
L
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1117
	mutex_lock(&ue->card->user_ctl_lock);
1118
	memcpy(&ucontrol->value, src, size);
1119
	mutex_unlock(&ue->card->user_ctl_lock);
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1120 1121 1122
	return 0;
}

1123 1124
static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
				 struct snd_ctl_elem_value *ucontrol)
L
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1125 1126 1127
{
	int change;
	struct user_element *ue = kcontrol->private_data;
1128 1129 1130
	unsigned int size = ue->elem_data_size;
	char *dst = ue->elem_data +
			snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1131 1132

	mutex_lock(&ue->card->user_ctl_lock);
1133
	change = memcmp(&ucontrol->value, dst, size) != 0;
L
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1134
	if (change)
1135
		memcpy(dst, &ucontrol->value, size);
1136
	mutex_unlock(&ue->card->user_ctl_lock);
L
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1137 1138 1139
	return change;
}

1140 1141 1142 1143 1144 1145 1146 1147 1148
static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
				 int op_flag,
				 unsigned int size,
				 unsigned int __user *tlv)
{
	struct user_element *ue = kcontrol->private_data;
	int change = 0;
	void *new_data;

1149
	if (op_flag == SNDRV_CTL_TLV_OP_WRITE) {
1150 1151
		if (size > 1024 * 128)	/* sane value */
			return -EINVAL;
L
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1152 1153 1154 1155

		new_data = memdup_user(tlv, size);
		if (IS_ERR(new_data))
			return PTR_ERR(new_data);
1156
		mutex_lock(&ue->card->user_ctl_lock);
1157 1158 1159 1160 1161 1162
		change = ue->tlv_data_size != size;
		if (!change)
			change = memcmp(ue->tlv_data, new_data, size);
		kfree(ue->tlv_data);
		ue->tlv_data = new_data;
		ue->tlv_data_size = size;
1163
		mutex_unlock(&ue->card->user_ctl_lock);
1164
	} else {
1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175
		int ret = 0;

		mutex_lock(&ue->card->user_ctl_lock);
		if (!ue->tlv_data_size || !ue->tlv_data) {
			ret = -ENXIO;
			goto err_unlock;
		}
		if (size < ue->tlv_data_size) {
			ret = -ENOSPC;
			goto err_unlock;
		}
1176
		if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1177 1178 1179 1180 1181
			ret = -EFAULT;
err_unlock:
		mutex_unlock(&ue->card->user_ctl_lock);
		if (ret)
			return ret;
1182 1183 1184 1185
	}
	return change;
}

1186 1187 1188 1189 1190
static int snd_ctl_elem_init_enum_names(struct user_element *ue)
{
	char *names, *p;
	size_t buf_len, name_len;
	unsigned int i;
1191
	const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1192 1193 1194 1195

	if (ue->info.value.enumerated.names_length > 64 * 1024)
		return -EINVAL;

1196
	names = memdup_user((const void __user *)user_ptrval,
1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219
		ue->info.value.enumerated.names_length);
	if (IS_ERR(names))
		return PTR_ERR(names);

	/* check that there are enough valid names */
	buf_len = ue->info.value.enumerated.names_length;
	p = names;
	for (i = 0; i < ue->info.value.enumerated.items; ++i) {
		name_len = strnlen(p, buf_len);
		if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
			kfree(names);
			return -EINVAL;
		}
		p += name_len + 1;
		buf_len -= name_len + 1;
	}

	ue->priv_data = names;
	ue->info.value.enumerated.names_ptr = 0;

	return 0;
}

1220
static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
L
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{
1222
	struct user_element *ue = kcontrol->private_data;
1223 1224 1225

	kfree(ue->tlv_data);
	kfree(ue->priv_data);
1226
	kfree(ue);
L
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1227 1228
}

1229 1230
static int snd_ctl_elem_add(struct snd_ctl_file *file,
			    struct snd_ctl_elem_info *info, int replace)
L
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{
1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248
	/* The capacity of struct snd_ctl_elem_value.value.*/
	static const unsigned int value_sizes[] = {
		[SNDRV_CTL_ELEM_TYPE_BOOLEAN]	= sizeof(long),
		[SNDRV_CTL_ELEM_TYPE_INTEGER]	= sizeof(long),
		[SNDRV_CTL_ELEM_TYPE_ENUMERATED] = sizeof(unsigned int),
		[SNDRV_CTL_ELEM_TYPE_BYTES]	= sizeof(unsigned char),
		[SNDRV_CTL_ELEM_TYPE_IEC958]	= sizeof(struct snd_aes_iec958),
		[SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long),
	};
	static const unsigned int max_value_counts[] = {
		[SNDRV_CTL_ELEM_TYPE_BOOLEAN]	= 128,
		[SNDRV_CTL_ELEM_TYPE_INTEGER]	= 128,
		[SNDRV_CTL_ELEM_TYPE_ENUMERATED] = 128,
		[SNDRV_CTL_ELEM_TYPE_BYTES]	= 512,
		[SNDRV_CTL_ELEM_TYPE_IEC958]	= 1,
		[SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64,
	};
1249
	struct snd_card *card = file->card;
1250 1251
	struct snd_kcontrol *kctl;
	unsigned int count;
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1252 1253 1254
	unsigned int access;
	long private_size;
	struct user_element *ue;
1255
	unsigned int offset;
1256
	int err;
1257

1258 1259 1260 1261
	if (!*info->id.name)
		return -EINVAL;
	if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
		return -EINVAL;
1262

1263
	/* Delete a control to replace them if needed. */
1264
	if (replace) {
1265
		info->id.numid = 0;
1266 1267 1268
		err = snd_ctl_remove_user_ctl(file, &info->id);
		if (err)
			return err;
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1269
	}
1270

1271 1272 1273 1274 1275
	/*
	 * The number of userspace controls are counted control by control,
	 * not element by element.
	 */
	if (card->user_ctl_count + 1 > MAX_USER_CONTROLS)
1276 1277
		return -ENOMEM;

1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290
	/* Check the number of elements for this userspace control. */
	count = info->owner;
	if (count == 0)
		count = 1;

	/* Arrange access permissions if needed. */
	access = info->access;
	if (access == 0)
		access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
	access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
		   SNDRV_CTL_ELEM_ACCESS_INACTIVE |
		   SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE);
	if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE)
1291
		access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1292
	access |= SNDRV_CTL_ELEM_ACCESS_USER;
1293

1294 1295 1296 1297
	/*
	 * Check information and calculate the size of data specific to
	 * this userspace control.
	 */
1298 1299
	if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
	    info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64)
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		return -EINVAL;
1301 1302 1303 1304 1305 1306
	if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED &&
	    info->value.enumerated.items == 0)
		return -EINVAL;
	if (info->count < 1 ||
	    info->count > max_value_counts[info->type])
		return -EINVAL;
1307 1308
	if (!validate_element_member_dimension(info))
		return -EINVAL;
1309
	private_size = value_sizes[info->type] * info->count;
1310 1311 1312 1313 1314 1315 1316 1317 1318 1319

	/*
	 * Keep memory object for this userspace control. After passing this
	 * code block, the instance should be freed by snd_ctl_free_one().
	 *
	 * Note that these elements in this control are locked.
	 */
	err = snd_ctl_new(&kctl, count, access, file);
	if (err < 0)
		return err;
1320
	memcpy(&kctl->id, &info->id, sizeof(kctl->id));
1321
	kctl->private_data = kzalloc(sizeof(struct user_element) + private_size * count,
1322 1323 1324
				     GFP_KERNEL);
	if (kctl->private_data == NULL) {
		kfree(kctl);
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		return -ENOMEM;
1326 1327 1328 1329 1330
	}
	kctl->private_free = snd_ctl_elem_user_free;

	/* Set private data for this userspace control. */
	ue = (struct user_element *)kctl->private_data;
1331
	ue->card = card;
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1332
	ue->info = *info;
1333
	ue->info.access = 0;
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	ue->elem_data = (char *)ue + sizeof(*ue);
	ue->elem_data_size = private_size;
1336 1337 1338
	if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
		err = snd_ctl_elem_init_enum_names(ue);
		if (err < 0) {
1339
			snd_ctl_free_one(kctl);
1340 1341 1342
			return err;
		}
	}
1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357

	/* Set callback functions. */
	if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
		kctl->info = snd_ctl_elem_user_enum_info;
	else
		kctl->info = snd_ctl_elem_user_info;
	if (access & SNDRV_CTL_ELEM_ACCESS_READ)
		kctl->get = snd_ctl_elem_user_get;
	if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
		kctl->put = snd_ctl_elem_user_put;
	if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE)
		kctl->tlv.c = snd_ctl_elem_user_tlv;

	/* This function manage to free the instance on failure. */
	err = snd_ctl_add(card, kctl);
1358
	if (err < 0)
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		return err;
1360 1361 1362 1363 1364 1365 1366 1367 1368
	offset = snd_ctl_get_ioff(kctl, &info->id);
	snd_ctl_build_ioff(&info->id, kctl, offset);
	/*
	 * Here we cannot fill any field for the number of elements added by
	 * this operation because there're no specific fields. The usage of
	 * 'owner' field for this purpose may cause any bugs to userspace
	 * applications because the field originally means PID of a process
	 * which locks the element.
	 */
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	down_write(&card->controls_rwsem);
	card->user_ctl_count++;
	up_write(&card->controls_rwsem);

	return 0;
}

1377 1378
static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
				 struct snd_ctl_elem_info __user *_info, int replace)
L
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1379
{
1380
	struct snd_ctl_elem_info info;
1381 1382
	int err;

L
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1383 1384
	if (copy_from_user(&info, _info, sizeof(info)))
		return -EFAULT;
1385 1386 1387 1388 1389 1390 1391 1392 1393
	err = snd_ctl_elem_add(file, &info, replace);
	if (err < 0)
		return err;
	if (copy_to_user(_info, &info, sizeof(info))) {
		snd_ctl_remove_user_ctl(file, &info.id);
		return -EFAULT;
	}

	return 0;
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}

1396 1397
static int snd_ctl_elem_remove(struct snd_ctl_file *file,
			       struct snd_ctl_elem_id __user *_id)
L
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1398
{
1399
	struct snd_ctl_elem_id id;
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	if (copy_from_user(&id, _id, sizeof(id)))
		return -EFAULT;
1403
	return snd_ctl_remove_user_ctl(file, &id);
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}

1406
static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
L
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{
	int subscribe;
	if (get_user(subscribe, ptr))
		return -EFAULT;
	if (subscribe < 0) {
		subscribe = file->subscribed;
		if (put_user(subscribe, ptr))
			return -EFAULT;
		return 0;
	}
	if (subscribe) {
		file->subscribed = 1;
		return 0;
	} else if (file->subscribed) {
		snd_ctl_empty_read_queue(file);
		file->subscribed = 0;
	}
	return 0;
}

1427 1428 1429
static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
                             struct snd_ctl_tlv __user *_tlv,
                             int op_flag)
1430
{
1431
	struct snd_card *card = file->card;
1432 1433
	struct snd_ctl_tlv tlv;
	struct snd_kcontrol *kctl;
1434
	struct snd_kcontrol_volatile *vd;
1435 1436 1437 1438 1439
	unsigned int len;
	int err = 0;

	if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
		return -EFAULT;
1440
	if (tlv.length < sizeof(unsigned int) * 2)
1441
		return -EINVAL;
1442 1443
	if (!tlv.numid)
		return -EINVAL;
1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454
	down_read(&card->controls_rwsem);
	kctl = snd_ctl_find_numid(card, tlv.numid);
	if (kctl == NULL) {
		err = -ENOENT;
		goto __kctl_end;
	}
	if (kctl->tlv.p == NULL) {
		err = -ENXIO;
		goto __kctl_end;
	}
	vd = &kctl->vd[tlv.numid - kctl->id.numid];
1455 1456 1457 1458 1459 1460
	if ((op_flag == SNDRV_CTL_TLV_OP_READ &&
	     (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
	    (op_flag == SNDRV_CTL_TLV_OP_WRITE &&
	     (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
	    (op_flag == SNDRV_CTL_TLV_OP_CMD &&
	     (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1461 1462 1463 1464
	    	err = -ENXIO;
	    	goto __kctl_end;
	}
	if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1465
		if (vd->owner != NULL && vd->owner != file) {
1466 1467 1468
			err = -EPERM;
			goto __kctl_end;
		}
1469
		err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1470
		if (err > 0) {
1471
			struct snd_ctl_elem_id id = kctl->id;
1472
			up_read(&card->controls_rwsem);
1473
			snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &id);
1474 1475 1476
			return 0;
		}
	} else {
1477
		if (op_flag != SNDRV_CTL_TLV_OP_READ) {
1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488
			err = -ENXIO;
			goto __kctl_end;
		}
		len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
		if (tlv.length < len) {
			err = -ENOMEM;
			goto __kctl_end;
		}
		if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
			err = -EFAULT;
	}
1489
      __kctl_end:
1490 1491
	up_read(&card->controls_rwsem);
	return err;
1492 1493
}

L
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1494 1495
static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
1496 1497 1498
	struct snd_ctl_file *ctl;
	struct snd_card *card;
	struct snd_kctl_ioctl *p;
L
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1499 1500 1501 1502 1503 1504
	void __user *argp = (void __user *)arg;
	int __user *ip = argp;
	int err;

	ctl = file->private_data;
	card = ctl->card;
1505 1506
	if (snd_BUG_ON(!card))
		return -ENXIO;
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1507 1508 1509 1510 1511 1512
	switch (cmd) {
	case SNDRV_CTL_IOCTL_PVERSION:
		return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
	case SNDRV_CTL_IOCTL_CARD_INFO:
		return snd_ctl_card_info(card, ctl, cmd, argp);
	case SNDRV_CTL_IOCTL_ELEM_LIST:
1513
		return snd_ctl_elem_list(card, argp);
L
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1514 1515 1516
	case SNDRV_CTL_IOCTL_ELEM_INFO:
		return snd_ctl_elem_info_user(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_READ:
1517
		return snd_ctl_elem_read_user(card, argp);
L
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1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531
	case SNDRV_CTL_IOCTL_ELEM_WRITE:
		return snd_ctl_elem_write_user(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_LOCK:
		return snd_ctl_elem_lock(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
		return snd_ctl_elem_unlock(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_ADD:
		return snd_ctl_elem_add_user(ctl, argp, 0);
	case SNDRV_CTL_IOCTL_ELEM_REPLACE:
		return snd_ctl_elem_add_user(ctl, argp, 1);
	case SNDRV_CTL_IOCTL_ELEM_REMOVE:
		return snd_ctl_elem_remove(ctl, argp);
	case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
		return snd_ctl_subscribe_events(ctl, ip);
1532
	case SNDRV_CTL_IOCTL_TLV_READ:
1533
		return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
1534
	case SNDRV_CTL_IOCTL_TLV_WRITE:
1535
		return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
1536
	case SNDRV_CTL_IOCTL_TLV_COMMAND:
1537
		return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
L
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1538
	case SNDRV_CTL_IOCTL_POWER:
T
Takashi Iwai 已提交
1539
		return -ENOPROTOOPT;
L
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1540 1541 1542 1543 1544 1545 1546 1547
	case SNDRV_CTL_IOCTL_POWER_STATE:
#ifdef CONFIG_PM
		return put_user(card->power_state, ip) ? -EFAULT : 0;
#else
		return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
#endif
	}
	down_read(&snd_ioctl_rwsem);
1548
	list_for_each_entry(p, &snd_control_ioctls, list) {
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1549 1550 1551 1552 1553 1554 1555
		err = p->fioctl(card, ctl, cmd, arg);
		if (err != -ENOIOCTLCMD) {
			up_read(&snd_ioctl_rwsem);
			return err;
		}
	}
	up_read(&snd_ioctl_rwsem);
1556
	dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
L
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1557 1558 1559
	return -ENOTTY;
}

1560 1561
static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
			    size_t count, loff_t * offset)
L
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1562
{
1563
	struct snd_ctl_file *ctl;
L
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1564 1565 1566 1567
	int err = 0;
	ssize_t result = 0;

	ctl = file->private_data;
1568 1569
	if (snd_BUG_ON(!ctl || !ctl->card))
		return -ENXIO;
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1570 1571
	if (!ctl->subscribed)
		return -EBADFD;
1572
	if (count < sizeof(struct snd_ctl_event))
L
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1573 1574
		return -EINVAL;
	spin_lock_irq(&ctl->read_lock);
1575 1576 1577
	while (count >= sizeof(struct snd_ctl_event)) {
		struct snd_ctl_event ev;
		struct snd_kctl_event *kev;
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1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589
		while (list_empty(&ctl->events)) {
			wait_queue_t wait;
			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
				err = -EAGAIN;
				goto __end_lock;
			}
			init_waitqueue_entry(&wait, current);
			add_wait_queue(&ctl->change_sleep, &wait);
			set_current_state(TASK_INTERRUPTIBLE);
			spin_unlock_irq(&ctl->read_lock);
			schedule();
			remove_wait_queue(&ctl->change_sleep, &wait);
1590 1591
			if (ctl->card->shutdown)
				return -ENODEV;
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1592
			if (signal_pending(current))
1593
				return -ERESTARTSYS;
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1594 1595 1596 1597 1598 1599 1600 1601 1602
			spin_lock_irq(&ctl->read_lock);
		}
		kev = snd_kctl_event(ctl->events.next);
		ev.type = SNDRV_CTL_EVENT_ELEM;
		ev.data.elem.mask = kev->mask;
		ev.data.elem.id = kev->id;
		list_del(&kev->list);
		spin_unlock_irq(&ctl->read_lock);
		kfree(kev);
1603
		if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
L
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			err = -EFAULT;
			goto __end;
		}
		spin_lock_irq(&ctl->read_lock);
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		buffer += sizeof(struct snd_ctl_event);
		count -= sizeof(struct snd_ctl_event);
		result += sizeof(struct snd_ctl_event);
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	}
      __end_lock:
	spin_unlock_irq(&ctl->read_lock);
      __end:
      	return result > 0 ? result : err;
}

static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
{
	unsigned int mask;
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	struct snd_ctl_file *ctl;
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	ctl = file->private_data;
	if (!ctl->subscribed)
		return 0;
	poll_wait(file, &ctl->change_sleep, wait);

	mask = 0;
	if (!list_empty(&ctl->events))
		mask |= POLLIN | POLLRDNORM;

	return mask;
}

/*
 * register the device-specific control-ioctls.
 * called from each device manager like pcm.c, hwdep.c, etc.
 */
static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
{
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	struct snd_kctl_ioctl *pn;
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	pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
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	if (pn == NULL)
		return -ENOMEM;
	pn->fioctl = fcn;
	down_write(&snd_ioctl_rwsem);
	list_add_tail(&pn->list, lists);
	up_write(&snd_ioctl_rwsem);
	return 0;
}

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/**
 * snd_ctl_register_ioctl - register the device-specific control-ioctls
 * @fcn: ioctl callback function
 *
 * called from each device manager like pcm.c, hwdep.c, etc.
 */
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int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
{
	return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
}
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EXPORT_SYMBOL(snd_ctl_register_ioctl);

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#ifdef CONFIG_COMPAT
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/**
 * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
 * control-ioctls
 * @fcn: ioctl callback function
 */
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int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
{
	return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
}
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EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
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#endif

/*
 * de-register the device-specific control-ioctls.
 */
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static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
				     struct list_head *lists)
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{
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	struct snd_kctl_ioctl *p;
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	if (snd_BUG_ON(!fcn))
		return -EINVAL;
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	down_write(&snd_ioctl_rwsem);
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	list_for_each_entry(p, lists, list) {
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		if (p->fioctl == fcn) {
			list_del(&p->list);
			up_write(&snd_ioctl_rwsem);
			kfree(p);
			return 0;
		}
	}
	up_write(&snd_ioctl_rwsem);
	snd_BUG();
	return -EINVAL;
}

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/**
 * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
 * @fcn: ioctl callback function to unregister
 */
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int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
{
	return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
}
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EXPORT_SYMBOL(snd_ctl_unregister_ioctl);

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#ifdef CONFIG_COMPAT
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/**
 * snd_ctl_unregister_ioctl - de-register the device-specific compat 32bit
 * control-ioctls
 * @fcn: ioctl callback function to unregister
 */
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int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
{
	return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
}
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EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
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#endif

static int snd_ctl_fasync(int fd, struct file * file, int on)
{
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	struct snd_ctl_file *ctl;
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	ctl = file->private_data;
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	return fasync_helper(fd, file, on, &ctl->fasync);
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}

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/* return the preferred subdevice number if already assigned;
 * otherwise return -1
 */
int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
{
	struct snd_ctl_file *kctl;
	int subdevice = -1;

	read_lock(&card->ctl_files_rwlock);
	list_for_each_entry(kctl, &card->ctl_files, list) {
		if (kctl->pid == task_pid(current)) {
			subdevice = kctl->preferred_subdevice[type];
			if (subdevice != -1)
				break;
		}
	}
	read_unlock(&card->ctl_files_rwlock);
	return subdevice;
}
EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);

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/*
 * ioctl32 compat
 */
#ifdef CONFIG_COMPAT
#include "control_compat.c"
#else
#define snd_ctl_ioctl_compat	NULL
#endif

/*
 *  INIT PART
 */

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static const struct file_operations snd_ctl_f_ops =
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{
	.owner =	THIS_MODULE,
	.read =		snd_ctl_read,
	.open =		snd_ctl_open,
	.release =	snd_ctl_release,
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	.llseek =	no_llseek,
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	.poll =		snd_ctl_poll,
	.unlocked_ioctl =	snd_ctl_ioctl,
	.compat_ioctl =	snd_ctl_ioctl_compat,
	.fasync =	snd_ctl_fasync,
};

/*
 * registration of the control device
 */
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static int snd_ctl_dev_register(struct snd_device *device)
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{
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	struct snd_card *card = device->device_data;
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	return snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
				   &snd_ctl_f_ops, card, &card->ctl_dev);
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}

/*
 * disconnection of the control device
 */
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static int snd_ctl_dev_disconnect(struct snd_device *device)
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{
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	struct snd_card *card = device->device_data;
	struct snd_ctl_file *ctl;
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	read_lock(&card->ctl_files_rwlock);
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	list_for_each_entry(ctl, &card->ctl_files, list) {
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		wake_up(&ctl->change_sleep);
		kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
	}
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	read_unlock(&card->ctl_files_rwlock);
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	return snd_unregister_device(&card->ctl_dev);
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}

/*
 * free all controls
 */
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static int snd_ctl_dev_free(struct snd_device *device)
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{
1814 1815
	struct snd_card *card = device->device_data;
	struct snd_kcontrol *control;
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	down_write(&card->controls_rwsem);
	while (!list_empty(&card->controls)) {
		control = snd_kcontrol(card->controls.next);
		snd_ctl_remove(card, control);
	}
	up_write(&card->controls_rwsem);
1823
	put_device(&card->ctl_dev);
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	return 0;
}

/*
 * create control core:
 * called from init.c
 */
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int snd_ctl_create(struct snd_card *card)
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{
1833
	static struct snd_device_ops ops = {
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		.dev_free = snd_ctl_dev_free,
		.dev_register =	snd_ctl_dev_register,
		.dev_disconnect = snd_ctl_dev_disconnect,
	};
1838
	int err;
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	if (snd_BUG_ON(!card))
		return -ENXIO;
1842 1843 1844 1845 1846 1847 1848 1849 1850 1851
	if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS))
		return -ENXIO;

	snd_device_initialize(&card->ctl_dev, card);
	dev_set_name(&card->ctl_dev, "controlC%d", card->number);

	err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
	if (err < 0)
		put_device(&card->ctl_dev);
	return err;
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}
1853 1854

/*
1855
 * Frequently used control callbacks/helpers
1856
 */
1857 1858 1859 1860 1861 1862 1863 1864 1865 1866

/**
 * snd_ctl_boolean_mono_info - Helper function for a standard boolean info
 * callback with a mono channel
 * @kcontrol: the kcontrol instance
 * @uinfo: info to store
 *
 * This is a function that can be used as info callback for a standard
 * boolean control with a single mono channel.
 */
1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877
int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
			      struct snd_ctl_elem_info *uinfo)
{
	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
	uinfo->count = 1;
	uinfo->value.integer.min = 0;
	uinfo->value.integer.max = 1;
	return 0;
}
EXPORT_SYMBOL(snd_ctl_boolean_mono_info);

1878 1879 1880 1881 1882 1883 1884 1885 1886
/**
 * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info
 * callback with stereo two channels
 * @kcontrol: the kcontrol instance
 * @uinfo: info to store
 *
 * This is a function that can be used as info callback for a standard
 * boolean control with stereo two channels.
 */
1887 1888 1889 1890 1891 1892 1893 1894 1895 1896
int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
				struct snd_ctl_elem_info *uinfo)
{
	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
	uinfo->count = 2;
	uinfo->value.integer.min = 0;
	uinfo->value.integer.max = 1;
	return 0;
}
EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907

/**
 * snd_ctl_enum_info - fills the info structure for an enumerated control
 * @info: the structure to be filled
 * @channels: the number of the control's channels; often one
 * @items: the number of control values; also the size of @names
 * @names: an array containing the names of all control values
 *
 * Sets all required fields in @info to their appropriate values.
 * If the control's accessibility is not the default (readable and writable),
 * the caller has to fill @info->access.
1908 1909
 *
 * Return: Zero.
1910 1911 1912 1913 1914 1915 1916
 */
int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
		      unsigned int items, const char *const names[])
{
	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
	info->count = channels;
	info->value.enumerated.items = items;
1917 1918
	if (!items)
		return 0;
1919 1920
	if (info->value.enumerated.item >= items)
		info->value.enumerated.item = items - 1;
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	WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
	     "ALSA: too long item name '%s'\n",
	     names[info->value.enumerated.item]);
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	strlcpy(info->value.enumerated.name,
		names[info->value.enumerated.item],
		sizeof(info->value.enumerated.name));
	return 0;
}
EXPORT_SYMBOL(snd_ctl_enum_info);