1 files changed, 208 insertions, 123 deletions

diff --git a/sound/core/control.c b/sound/core/control.c
index 35324a8e83c8..196a6fe100ca 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -192,36 +192,41 @@ void snd_ctl_notify(struct snd_card *card, unsigned int mask,
 EXPORT_SYMBOL(snd_ctl_notify);
 
 /**
- * snd_ctl_new - create a control instance from the template
- * @control: the control template
- * @access: the default control access
+ * 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
  *
- * Allocates a new struct snd_kcontrol instance and copies the given template 
- * to the new instance. It does not copy volatile data (access).
+ * 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.
  *
- * Return: The pointer of the new instance, or %NULL on failure.
+ * Return: 0 on success, error code on failure
  */
-static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
-					unsigned int access)
+static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count,
+		       unsigned int access, struct snd_ctl_file *file)
 {
-	struct snd_kcontrol *kctl;
+	unsigned int size;
 	unsigned int idx;
 	
-	if (snd_BUG_ON(!control || !control->count))
-		return NULL;
+	if (count == 0 || count > MAX_CONTROL_COUNT)
+		return -EINVAL;
 
-	if (control->count > MAX_CONTROL_COUNT)
-		return NULL;
+	size  = sizeof(struct snd_kcontrol);
+	size += sizeof(struct snd_kcontrol_volatile) * count;
 
-	kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
-	if (kctl == NULL) {
-		pr_err("ALSA: Cannot allocate control instance\n");
-		return NULL;
+	*kctl = kzalloc(size, GFP_KERNEL);
+	if (!*kctl)
+		return -ENOMEM;
+
+	for (idx = 0; idx < count; idx++) {
+		(*kctl)->vd[idx].access = access;
+		(*kctl)->vd[idx].owner = file;
 	}
-	*kctl = *control;
-	for (idx = 0; idx < kctl->count; idx++)
-		kctl->vd[idx].access = access;
-	return kctl;
+	(*kctl)->count = count;
+
+	return 0;
 }
 
 /**
@@ -238,37 +243,53 @@ static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 				  void *private_data)
 {
-	struct snd_kcontrol kctl;
+	struct snd_kcontrol *kctl;
+	unsigned int count;
 	unsigned int access;
+	int err;
 	
 	if (snd_BUG_ON(!ncontrol || !ncontrol->info))
 		return NULL;
-	memset(&kctl, 0, sizeof(kctl));
-	kctl.id.iface = ncontrol->iface;
-	kctl.id.device = ncontrol->device;
-	kctl.id.subdevice = ncontrol->subdevice;
+
+	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;
 	if (ncontrol->name) {
-		strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
-		if (strcmp(ncontrol->name, kctl.id.name) != 0)
+		strlcpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.name));
+		if (strcmp(ncontrol->name, kctl->id.name) != 0)
 			pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
-				ncontrol->name, kctl.id.name);
+				ncontrol->name, kctl->id.name);
 	}
-	kctl.id.index = ncontrol->index;
-	kctl.count = ncontrol->count ? ncontrol->count : 1;
-	access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
-		 (ncontrol->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));
-	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 snd_ctl_new(&kctl, access);
+	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;
 }
 EXPORT_SYMBOL(snd_ctl_new1);
 
@@ -557,6 +578,7 @@ error:
  *
  * Finds the control instance with the given id, and activate or
  * inactivate the control together with notification, if changed.
+ * The given ID data is filled with full information.
  *
  * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
  */
@@ -586,6 +608,7 @@ int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
 			goto unlock;
 		vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 	}
+	snd_ctl_build_ioff(id, kctl, index_offset);
 	ret = 1;
  unlock:
 	up_write(&card->controls_rwsem);
@@ -1006,7 +1029,7 @@ static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 struct user_element {
 	struct snd_ctl_elem_info info;
 	struct snd_card *card;
-	void *elem_data;		/* element data */
+	char *elem_data;		/* element data */
 	unsigned long elem_data_size;	/* size of element data in bytes */
 	void *tlv_data;			/* TLV data */
 	unsigned long tlv_data_size;	/* TLV data size */
@@ -1017,8 +1040,12 @@ static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
 				  struct snd_ctl_elem_info *uinfo)
 {
 	struct user_element *ue = kcontrol->private_data;
+	unsigned int offset;
 
+	offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
 	*uinfo = ue->info;
+	snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
+
 	return 0;
 }
 
@@ -1028,10 +1055,13 @@ static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
 	struct user_element *ue = kcontrol->private_data;
 	const char *names;
 	unsigned int item;
+	unsigned int offset;
 
 	item = uinfo->value.enumerated.item;
 
+	offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
 	*uinfo = ue->info;
+	snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
 
 	item = min(item, uinfo->value.enumerated.items - 1);
 	uinfo->value.enumerated.item = item;
@@ -1048,9 +1078,12 @@ static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
 				 struct snd_ctl_elem_value *ucontrol)
 {
 	struct user_element *ue = kcontrol->private_data;
+	unsigned int size = ue->elem_data_size;
+	char *src = ue->elem_data +
+			snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
 
 	mutex_lock(&ue->card->user_ctl_lock);
-	memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
+	memcpy(&ucontrol->value, src, size);
 	mutex_unlock(&ue->card->user_ctl_lock);
 	return 0;
 }
@@ -1060,11 +1093,14 @@ static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
 {
 	int change;
 	struct user_element *ue = kcontrol->private_data;
+	unsigned int size = ue->elem_data_size;
+	char *dst = ue->elem_data +
+			snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
 
 	mutex_lock(&ue->card->user_ctl_lock);
-	change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
+	change = memcmp(&ucontrol->value, dst, size) != 0;
 	if (change)
-		memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
+		memcpy(dst, &ucontrol->value, size);
 	mutex_unlock(&ue->card->user_ctl_lock);
 	return change;
 }
@@ -1078,7 +1114,7 @@ static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
 	int change = 0;
 	void *new_data;
 
-	if (op_flag > 0) {
+	if (op_flag == SNDRV_CTL_TLV_OP_WRITE) {
 		if (size > 1024 * 128)	/* sane value */
 			return -EINVAL;
 
@@ -1161,80 +1197,103 @@ static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
 static int snd_ctl_elem_add(struct snd_ctl_file *file,
 			    struct snd_ctl_elem_info *info, int replace)
 {
+	/* 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,
+	};
 	struct snd_card *card = file->card;
-	struct snd_kcontrol kctl, *_kctl;
+	struct snd_kcontrol *kctl;
+	unsigned int count;
 	unsigned int access;
 	long private_size;
 	struct user_element *ue;
-	int idx, err;
+	unsigned int offset;
+	int err;
 
-	if (info->count < 1)
+	if (!*info->id.name)
+		return -EINVAL;
+	if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
 		return -EINVAL;
-	access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
-		(info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
-				 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
-				 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
-	info->id.numid = 0;
-	memset(&kctl, 0, sizeof(kctl));
 
+	/* Delete a control to replace them if needed. */
 	if (replace) {
+		info->id.numid = 0;
 		err = snd_ctl_remove_user_ctl(file, &info->id);
 		if (err)
 			return err;
 	}
 
-	if (card->user_ctl_count >= MAX_USER_CONTROLS)
+	/*
+	 * The number of userspace controls are counted control by control,
+	 * not element by element.
+	 */
+	if (card->user_ctl_count + 1 > MAX_USER_CONTROLS)
 		return -ENOMEM;
 
-	memcpy(&kctl.id, &info->id, sizeof(info->id));
-	kctl.count = info->owner ? info->owner : 1;
-	access |= SNDRV_CTL_ELEM_ACCESS_USER;
-	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;
+	/* 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)
 		access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
-	}
-	switch (info->type) {
-	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
-	case SNDRV_CTL_ELEM_TYPE_INTEGER:
-		private_size = sizeof(long);
-		if (info->count > 128)
-			return -EINVAL;
-		break;
-	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
-		private_size = sizeof(long long);
-		if (info->count > 64)
-			return -EINVAL;
-		break;
-	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
-		private_size = sizeof(unsigned int);
-		if (info->count > 128 || info->value.enumerated.items == 0)
-			return -EINVAL;
-		break;
-	case SNDRV_CTL_ELEM_TYPE_BYTES:
-		private_size = sizeof(unsigned char);
-		if (info->count > 512)
-			return -EINVAL;
-		break;
-	case SNDRV_CTL_ELEM_TYPE_IEC958:
-		private_size = sizeof(struct snd_aes_iec958);
-		if (info->count != 1)
-			return -EINVAL;
-		break;
-	default:
+	access |= SNDRV_CTL_ELEM_ACCESS_USER;
+
+	/*
+	 * Check information and calculate the size of data specific to
+	 * this userspace control.
+	 */
+	if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
+	    info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64)
 		return -EINVAL;
-	}
-	private_size *= info->count;
-	ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
-	if (ue == NULL)
+	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;
+	private_size = value_sizes[info->type] * info->count;
+
+	/*
+	 * 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;
+	memcpy(&kctl->id, &info->id, sizeof(kctl->id));
+	kctl->private_data = kzalloc(sizeof(struct user_element) + private_size * count,
+				     GFP_KERNEL);
+	if (kctl->private_data == NULL) {
+		kfree(kctl);
 		return -ENOMEM;
+	}
+	kctl->private_free = snd_ctl_elem_user_free;
+
+	/* Set private data for this userspace control. */
+	ue = (struct user_element *)kctl->private_data;
 	ue->card = card;
 	ue->info = *info;
 	ue->info.access = 0;
@@ -1243,23 +1302,36 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file,
 	if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
 		err = snd_ctl_elem_init_enum_names(ue);
 		if (err < 0) {
-			kfree(ue);
+			snd_ctl_free_one(kctl);
 			return err;
 		}
 	}
-	kctl.private_free = snd_ctl_elem_user_free;
-	_kctl = snd_ctl_new(&kctl, access);
-	if (_kctl == NULL) {
-		kfree(ue->priv_data);
-		kfree(ue);
-		return -ENOMEM;
-	}
-	_kctl->private_data = ue;
-	for (idx = 0; idx < _kctl->count; idx++)
-		_kctl->vd[idx].owner = file;
-	err = snd_ctl_add(card, _kctl);
+
+	/* 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);
 	if (err < 0)
 		return err;
+	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.
+	 */
 
 	down_write(&card->controls_rwsem);
 	card->user_ctl_count++;
@@ -1272,9 +1344,19 @@ static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
 				 struct snd_ctl_elem_info __user *_info, int replace)
 {
 	struct snd_ctl_elem_info info;
+	int err;
+
 	if (copy_from_user(&info, _info, sizeof(info)))
 		return -EFAULT;
-	return snd_ctl_elem_add(file, &info, replace);
+	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;
 }
 
 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
@@ -1334,9 +1416,12 @@ static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
 		goto __kctl_end;
 	}
 	vd = &kctl->vd[tlv.numid - kctl->id.numid];
-	if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
-	    (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
-	    (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
+	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)) {
 	    	err = -ENXIO;
 	    	goto __kctl_end;
 	}
@@ -1353,7 +1438,7 @@ static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
 			return 0;
 		}
 	} else {
-		if (op_flag) {
+		if (op_flag != SNDRV_CTL_TLV_OP_READ) {
 			err = -ENXIO;
 			goto __kctl_end;
 		}