control.c 49.8 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>
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#include <linux/sched/signal.h>
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#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) {
564 565
			ret = -EBUSY;
			goto error;
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		}
	ret = snd_ctl_remove(card, kctl);
568 569 570
	if (ret < 0)
		goto error;
	card->user_ctl_count--;
571
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.
584
 * The given ID data is filled with full information.
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 *
586
 * 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;
	}
602
	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;
	}
614
	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.
 *
633
 * Return: Zero if successful, or a negative error code on failure.
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 */
635 636
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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{
638
	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;
}
652 653
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).
663 664 665
 *
 * Return: The pointer of the instance if found, or %NULL if not.
 *
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 */
667
struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
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{
669
	struct snd_kcontrol *kctl;
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671 672
	if (snd_BUG_ON(!card || !numid))
		return NULL;
673
	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;
}
679 680
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).
690 691 692
 *
 * Return: The pointer of the instance if found, or %NULL if not.
 *
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 */
694 695
struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
				     struct snd_ctl_elem_id *id)
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{
697
	struct snd_kcontrol *kctl;
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699 700
	if (snd_BUG_ON(!card || !id))
		return NULL;
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	if (id->numid != 0)
		return snd_ctl_find_numid(card, id->numid);
703
	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;
}
720 721
EXPORT_SYMBOL(snd_ctl_find_id);

722
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)
{
725
	struct snd_ctl_card_info *info;
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727
	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);
739
	if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
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		kfree(info);
		return -EFAULT;
	}
	kfree(info);
	return 0;
}

747 748
static int snd_ctl_elem_list(struct snd_card *card,
			     struct snd_ctl_elem_list __user *_list)
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{
750 751
	struct snd_ctl_elem_list list;
	struct snd_kcontrol *kctl;
752
	struct snd_ctl_elem_id id;
753
	unsigned int offset, space, jidx;
754
	int err = 0;
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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;
763 764 765
	down_read(&card->controls_rwsem);
	list.count = card->controls_count;
	list.used = 0;
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	if (space > 0) {
767 768 769 770 771 772 773 774 775 776 777 778
		list_for_each_entry(kctl, &card->controls, list) {
			if (offset >= kctl->count) {
				offset -= kctl->count;
				continue;
			}
			for (jidx = offset; jidx < kctl->count; jidx++) {
				snd_ctl_build_ioff(&id, kctl, jidx);
				if (copy_to_user(list.pids + list.used, &id,
						 sizeof(id))) {
					err = -EFAULT;
					goto out;
				}
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				list.used++;
780 781
				if (!--space)
					goto out;
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			}
			offset = 0;
		}
	}
786 787 788 789 790
 out:
	up_read(&card->controls_rwsem);
	if (!err && copy_to_user(_list, &list, sizeof(list)))
		err = -EFAULT;
	return err;
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}

793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822
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;
}

823 824
static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
			     struct snd_ctl_elem_info *info)
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{
826 827 828
	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) {
843
		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;
852
			info->owner = pid_vnr(vd->owner->pid);
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		} else {
			info->owner = -1;
		}
	}
	up_read(&card->controls_rwsem);
	return result;
}

861 862
static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
				  struct snd_ctl_elem_info __user *_info)
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{
864
	struct snd_ctl_elem_info info;
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	int result;

	if (copy_from_user(&info, _info, sizeof(info)))
		return -EFAULT;
869
	snd_power_lock(ctl->card);
870
	result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
871 872 873
	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;
}

880 881
static int snd_ctl_elem_read(struct snd_card *card,
			     struct snd_ctl_elem_value *control)
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{
883 884
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
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	unsigned int index_offset;
886
	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];
895 896 897 898 899 900
		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;
}

906 907
static int snd_ctl_elem_read_user(struct snd_card *card,
				  struct snd_ctl_elem_value __user *_control)
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{
909
	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);

916
	snd_power_lock(card);
917
	result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
918 919 920
	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;
}

928 929
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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{
931 932
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
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	unsigned int index_offset;
934
	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];
943 944 945 946
		if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
		    kctl->put == NULL ||
		    (file && vd->owner && vd->owner != file)) {
			result = -EPERM;
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		} else {
948 949 950 951
			snd_ctl_build_ioff(&control->id, kctl, index_offset);
			result = kctl->put(kctl, control);
		}
		if (result > 0) {
952
			struct snd_ctl_elem_id id = control->id;
953
			up_read(&card->controls_rwsem);
954
			snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
955
			return 0;
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		}
	}
	up_read(&card->controls_rwsem);
	return result;
}

962 963
static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
				   struct snd_ctl_elem_value __user *_control)
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{
965
	struct snd_ctl_elem_value *control;
966
	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);

973 974
	card = file->card;
	snd_power_lock(card);
975
	result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
976 977 978
	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;
}

986 987
static int snd_ctl_elem_lock(struct snd_ctl_file *file,
			     struct snd_ctl_elem_id __user *_id)
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{
989 990 991 992
	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;
}

1014 1015
static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
			       struct snd_ctl_elem_id __user *_id)
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{
1017 1018 1019 1020
	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 {
1045
	struct snd_ctl_elem_info info;
1046
	struct snd_card *card;
1047
	char *elem_data;		/* element data */
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	unsigned long elem_data_size;	/* size of element data in bytes */
1049 1050
	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) */
};

1054 1055
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;
1058
	unsigned int offset;
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1060
	offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
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	*uinfo = ue->info;
1062 1063
	snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);

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	return 0;
}

1067 1068 1069 1070 1071 1072
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;
1073
	unsigned int offset;
1074 1075 1076

	item = uinfo->value.enumerated.item;

1077
	offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1078
	*uinfo = ue->info;
1079
	snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091

	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;
}

1092 1093
static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
				 struct snd_ctl_elem_value *ucontrol)
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{
	struct user_element *ue = kcontrol->private_data;
1096 1097 1098
	unsigned int size = ue->elem_data_size;
	char *src = ue->elem_data +
			snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
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1100
	mutex_lock(&ue->card->user_ctl_lock);
1101
	memcpy(&ucontrol->value, src, size);
1102
	mutex_unlock(&ue->card->user_ctl_lock);
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	return 0;
}

1106 1107
static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
				 struct snd_ctl_elem_value *ucontrol)
L
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1108 1109 1110
{
	int change;
	struct user_element *ue = kcontrol->private_data;
1111 1112 1113
	unsigned int size = ue->elem_data_size;
	char *dst = ue->elem_data +
			snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1114 1115

	mutex_lock(&ue->card->user_ctl_lock);
1116
	change = memcmp(&ucontrol->value, dst, size) != 0;
L
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1117
	if (change)
1118
		memcpy(dst, &ucontrol->value, size);
1119
	mutex_unlock(&ue->card->user_ctl_lock);
L
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1120 1121 1122
	return change;
}

1123 1124 1125 1126 1127 1128 1129 1130 1131
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;

1132
	if (op_flag == SNDRV_CTL_TLV_OP_WRITE) {
1133 1134
		if (size > 1024 * 128)	/* sane value */
			return -EINVAL;
L
Li Zefan 已提交
1135 1136 1137 1138

		new_data = memdup_user(tlv, size);
		if (IS_ERR(new_data))
			return PTR_ERR(new_data);
1139
		mutex_lock(&ue->card->user_ctl_lock);
1140 1141 1142 1143 1144 1145
		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;
1146
		mutex_unlock(&ue->card->user_ctl_lock);
1147
	} else {
1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158
		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;
		}
1159
		if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1160 1161 1162 1163 1164
			ret = -EFAULT;
err_unlock:
		mutex_unlock(&ue->card->user_ctl_lock);
		if (ret)
			return ret;
1165 1166 1167 1168
	}
	return change;
}

1169 1170 1171 1172 1173
static int snd_ctl_elem_init_enum_names(struct user_element *ue)
{
	char *names, *p;
	size_t buf_len, name_len;
	unsigned int i;
1174
	const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1175 1176 1177 1178

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

1179
	names = memdup_user((const void __user *)user_ptrval,
1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202
		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;
}

1203
static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
L
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1204
{
1205
	struct user_element *ue = kcontrol->private_data;
1206 1207 1208

	kfree(ue->tlv_data);
	kfree(ue->priv_data);
1209
	kfree(ue);
L
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1210 1211
}

1212 1213
static int snd_ctl_elem_add(struct snd_ctl_file *file,
			    struct snd_ctl_elem_info *info, int replace)
L
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1214
{
1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231
	/* 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,
	};
1232
	struct snd_card *card = file->card;
1233 1234
	struct snd_kcontrol *kctl;
	unsigned int count;
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1235 1236 1237
	unsigned int access;
	long private_size;
	struct user_element *ue;
1238
	unsigned int offset;
1239
	int err;
1240

1241 1242 1243 1244
	if (!*info->id.name)
		return -EINVAL;
	if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
		return -EINVAL;
1245

1246
	/* Delete a control to replace them if needed. */
1247
	if (replace) {
1248
		info->id.numid = 0;
1249 1250 1251
		err = snd_ctl_remove_user_ctl(file, &info->id);
		if (err)
			return err;
L
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1252
	}
1253

1254 1255 1256 1257 1258
	/*
	 * The number of userspace controls are counted control by control,
	 * not element by element.
	 */
	if (card->user_ctl_count + 1 > MAX_USER_CONTROLS)
1259 1260
		return -ENOMEM;

1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273
	/* 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)
1274
		access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1275
	access |= SNDRV_CTL_ELEM_ACCESS_USER;
1276

1277 1278 1279 1280
	/*
	 * Check information and calculate the size of data specific to
	 * this userspace control.
	 */
1281 1282
	if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
	    info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64)
L
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1283
		return -EINVAL;
1284 1285 1286 1287 1288 1289
	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;
1290 1291
	if (!validate_element_member_dimension(info))
		return -EINVAL;
1292
	private_size = value_sizes[info->type] * info->count;
1293 1294 1295 1296 1297 1298 1299 1300 1301 1302

	/*
	 * 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;
1303
	memcpy(&kctl->id, &info->id, sizeof(kctl->id));
1304
	kctl->private_data = kzalloc(sizeof(struct user_element) + private_size * count,
1305 1306 1307
				     GFP_KERNEL);
	if (kctl->private_data == NULL) {
		kfree(kctl);
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1308
		return -ENOMEM;
1309 1310 1311 1312 1313
	}
	kctl->private_free = snd_ctl_elem_user_free;

	/* Set private data for this userspace control. */
	ue = (struct user_element *)kctl->private_data;
1314
	ue->card = card;
L
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1315
	ue->info = *info;
1316
	ue->info.access = 0;
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1317 1318
	ue->elem_data = (char *)ue + sizeof(*ue);
	ue->elem_data_size = private_size;
1319 1320 1321
	if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
		err = snd_ctl_elem_init_enum_names(ue);
		if (err < 0) {
1322
			snd_ctl_free_one(kctl);
1323 1324 1325
			return err;
		}
	}
1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340

	/* 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);
1341
	if (err < 0)
L
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1342
		return err;
1343 1344 1345 1346 1347 1348 1349 1350 1351
	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.
	 */
L
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1352 1353 1354 1355 1356 1357 1358 1359

	down_write(&card->controls_rwsem);
	card->user_ctl_count++;
	up_write(&card->controls_rwsem);

	return 0;
}

1360 1361
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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1362
{
1363
	struct snd_ctl_elem_info info;
1364 1365
	int err;

L
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1366 1367
	if (copy_from_user(&info, _info, sizeof(info)))
		return -EFAULT;
1368 1369 1370 1371 1372 1373 1374 1375 1376
	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;
L
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1377 1378
}

1379 1380
static int snd_ctl_elem_remove(struct snd_ctl_file *file,
			       struct snd_ctl_elem_id __user *_id)
L
Linus Torvalds 已提交
1381
{
1382
	struct snd_ctl_elem_id id;
L
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1383 1384 1385

	if (copy_from_user(&id, _id, sizeof(id)))
		return -EFAULT;
1386
	return snd_ctl_remove_user_ctl(file, &id);
L
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1387 1388
}

1389
static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
L
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1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409
{
	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;
}

1410 1411 1412
static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
                             struct snd_ctl_tlv __user *_tlv,
                             int op_flag)
1413
{
1414
	struct snd_card *card = file->card;
1415 1416
	struct snd_ctl_tlv tlv;
	struct snd_kcontrol *kctl;
1417
	struct snd_kcontrol_volatile *vd;
1418 1419 1420 1421 1422
	unsigned int len;
	int err = 0;

	if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
		return -EFAULT;
1423
	if (tlv.length < sizeof(unsigned int) * 2)
1424
		return -EINVAL;
1425 1426
	if (!tlv.numid)
		return -EINVAL;
1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437
	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];
1438 1439 1440 1441 1442 1443
	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)) {
1444 1445 1446 1447
	    	err = -ENXIO;
	    	goto __kctl_end;
	}
	if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1448
		if (vd->owner != NULL && vd->owner != file) {
1449 1450 1451
			err = -EPERM;
			goto __kctl_end;
		}
1452
		err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1453
		if (err > 0) {
1454
			struct snd_ctl_elem_id id = kctl->id;
1455
			up_read(&card->controls_rwsem);
1456
			snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &id);
1457 1458 1459
			return 0;
		}
	} else {
1460
		if (op_flag != SNDRV_CTL_TLV_OP_READ) {
1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471
			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;
	}
1472
      __kctl_end:
1473 1474
	up_read(&card->controls_rwsem);
	return err;
1475 1476
}

L
Linus Torvalds 已提交
1477 1478
static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
1479 1480 1481
	struct snd_ctl_file *ctl;
	struct snd_card *card;
	struct snd_kctl_ioctl *p;
L
Linus Torvalds 已提交
1482 1483 1484 1485 1486 1487
	void __user *argp = (void __user *)arg;
	int __user *ip = argp;
	int err;

	ctl = file->private_data;
	card = ctl->card;
1488 1489
	if (snd_BUG_ON(!card))
		return -ENXIO;
L
Linus Torvalds 已提交
1490 1491 1492 1493 1494 1495
	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:
1496
		return snd_ctl_elem_list(card, argp);
L
Linus Torvalds 已提交
1497 1498 1499
	case SNDRV_CTL_IOCTL_ELEM_INFO:
		return snd_ctl_elem_info_user(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_READ:
1500
		return snd_ctl_elem_read_user(card, argp);
L
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1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514
	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);
1515
	case SNDRV_CTL_IOCTL_TLV_READ:
1516
		return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
1517
	case SNDRV_CTL_IOCTL_TLV_WRITE:
1518
		return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
1519
	case SNDRV_CTL_IOCTL_TLV_COMMAND:
1520
		return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
L
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1521
	case SNDRV_CTL_IOCTL_POWER:
T
Takashi Iwai 已提交
1522
		return -ENOPROTOOPT;
L
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1523 1524 1525 1526 1527 1528 1529 1530
	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);
1531
	list_for_each_entry(p, &snd_control_ioctls, list) {
L
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1532 1533 1534 1535 1536 1537 1538
		err = p->fioctl(card, ctl, cmd, arg);
		if (err != -ENOIOCTLCMD) {
			up_read(&snd_ioctl_rwsem);
			return err;
		}
	}
	up_read(&snd_ioctl_rwsem);
1539
	dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
L
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1540 1541 1542
	return -ENOTTY;
}

1543 1544
static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
			    size_t count, loff_t * offset)
L
Linus Torvalds 已提交
1545
{
1546
	struct snd_ctl_file *ctl;
L
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1547 1548 1549 1550
	int err = 0;
	ssize_t result = 0;

	ctl = file->private_data;
1551 1552
	if (snd_BUG_ON(!ctl || !ctl->card))
		return -ENXIO;
L
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1553 1554
	if (!ctl->subscribed)
		return -EBADFD;
1555
	if (count < sizeof(struct snd_ctl_event))
L
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1556 1557
		return -EINVAL;
	spin_lock_irq(&ctl->read_lock);
1558 1559 1560
	while (count >= sizeof(struct snd_ctl_event)) {
		struct snd_ctl_event ev;
		struct snd_kctl_event *kev;
L
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1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572
		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);
1573 1574
			if (ctl->card->shutdown)
				return -ENODEV;
L
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1575
			if (signal_pending(current))
1576
				return -ERESTARTSYS;
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1577 1578 1579 1580 1581 1582 1583 1584 1585
			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);
1586
		if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
L
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1587 1588 1589 1590
			err = -EFAULT;
			goto __end;
		}
		spin_lock_irq(&ctl->read_lock);
1591 1592 1593
		buffer += sizeof(struct snd_ctl_event);
		count -= sizeof(struct snd_ctl_event);
		result += sizeof(struct snd_ctl_event);
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1594 1595 1596 1597 1598 1599 1600 1601 1602 1603
	}
      __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;
1604
	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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{
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	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);
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	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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{
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	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,
	};
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	int err;
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	if (snd_BUG_ON(!card))
		return -ENXIO;
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	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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}
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/*
1838
 * Frequently used control callbacks/helpers
1839
 */
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/**
 * 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.
 */
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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);

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/**
 * 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.
 */
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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);
1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890

/**
 * 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.
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 *
 * Return: Zero.
1893 1894 1895 1896 1897 1898 1899
 */
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;
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	if (!items)
		return 0;
1902 1903
	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);