[ALSA] unlocked/compat_ioctl rewrite for control API

Control Midlevel
ioctl handler for control API is rewritten using unlocked/compat_ioctl.
The 32bit wrapper is merged to the core module.

Added a new register/unregister function for compat control ioctls.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

include/sound/control.h

@@ -119,6 +119,13 @@ int snd_ctl_create(snd_card_t *card);
 
 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn);
 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn);
+#ifdef CONFIG_COMPAT
+int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn);
+int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn);
+#else
+#define snd_ctl_register_ioctl_compat(fcn)
+#define snd_ctl_unregister_ioctl_compat(fcn)
+#endif
 
 int snd_ctl_elem_read(snd_card_t *card, snd_ctl_elem_value_t *control);
 int snd_ctl_elem_write(snd_card_t *card, snd_ctl_file_t *file, snd_ctl_elem_value_t *control);

sound/core/control.c

@@ -43,6 +43,9 @@ typedef struct _snd_kctl_ioctl {
 
 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)
 {
@@ -595,43 +598,51 @@ static int snd_ctl_elem_list(snd_card_t *card, snd_ctl_elem_list_t __user *_list
 	return 0;
 }
 
-static int snd_ctl_elem_info(snd_ctl_file_t *ctl, snd_ctl_elem_info_t __user *_info)
+static int snd_ctl_elem_info(snd_ctl_file_t *ctl, snd_ctl_elem_info_t *info)
 {
 	snd_card_t *card = ctl->card;
-	snd_ctl_elem_info_t info;
 	snd_kcontrol_t *kctl;
 	snd_kcontrol_volatile_t *vd;
 	unsigned int index_offset;
 	int result;
 	
-	if (copy_from_user(&info, _info, sizeof(info)))
-		return -EFAULT;
 	down_read(&card->controls_rwsem);
-	kctl = snd_ctl_find_id(card, &info.id);
+	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;
+	info->access = 0;
 #endif
-	result = kctl->info(kctl, &info);
+	result = kctl->info(kctl, info);
 	if (result >= 0) {
-		snd_assert(info.access == 0, );
-		index_offset = snd_ctl_get_ioff(kctl, &info.id);
+		snd_assert(info->access == 0, );
+		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;
+		snd_ctl_build_ioff(&info->id, kctl, index_offset);
+		info->access = vd->access;
 		if (vd->owner) {
-			info.access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
+			info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 			if (vd->owner == ctl)
-				info.access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
-			info.owner = vd->owner_pid;
+				info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
+			info->owner = vd->owner_pid;
 		} else {
-			info.owner = -1;
+			info->owner = -1;
 		}
 	}
 	up_read(&card->controls_rwsem);
+	return result;
+}
+
+static int snd_ctl_elem_info_user(snd_ctl_file_t *ctl, snd_ctl_elem_info_t __user *_info)
+{
+	snd_ctl_elem_info_t info;
+	int result;
+
+	if (copy_from_user(&info, _info, sizeof(info)))
+		return -EFAULT;
+	result = snd_ctl_elem_info(ctl, &info);
 	if (result >= 0)
 		if (copy_to_user(_info, &info, sizeof(info)))
 			return -EFAULT;
@@ -816,14 +827,6 @@ static int snd_ctl_elem_user_info(snd_kcontrol_t *kcontrol, snd_ctl_elem_info_t
 	struct user_element *ue = kcontrol->private_data;
 
 	*uinfo = ue->info;
-	if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
-		uinfo->value.enumerated.items = ue->info.value.enumerated.items;
-		if (uinfo->value.enumerated.item >= ue->info.value.enumerated.items)
-			uinfo->value.enumerated.item = 0;
-		strlcpy(uinfo->value.enumerated.name,
-			(char *)ue->priv_data + uinfo->value.enumerated.item * 64,
-			64);
-	}
 	return 0;
 }
 
@@ -851,28 +854,25 @@ static void snd_ctl_elem_user_free(snd_kcontrol_t * kcontrol)
 	kfree(kcontrol->private_data);
 }
 
-static int snd_ctl_elem_add(snd_ctl_file_t *file, snd_ctl_elem_info_t __user *_info, int replace)
+static int snd_ctl_elem_add(snd_ctl_file_t *file, snd_ctl_elem_info_t *info, int replace)
 {
 	snd_card_t *card = file->card;
-	snd_ctl_elem_info_t info;
 	snd_kcontrol_t kctl, *_kctl;
 	unsigned int access;
-	long private_size, extra_size;
+	long private_size;
 	struct user_element *ue;
 	int idx, err;
 	
 	if (card->user_ctl_count >= MAX_USER_CONTROLS)
 		return -ENOMEM;
-	if (copy_from_user(&info, _info, sizeof(info)))
-		return -EFAULT;
-	if (info.count > 1024)
+	if (info->count > 1024)
 		return -EINVAL;
-	access = info.access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
-		(info.access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|SNDRV_CTL_ELEM_ACCESS_INACTIVE));
-	info.id.numid = 0;
+	access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
+		(info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|SNDRV_CTL_ELEM_ACCESS_INACTIVE));
+	info->id.numid = 0;
 	memset(&kctl, 0, sizeof(kctl));
 	down_write(&card->controls_rwsem);
-	_kctl = snd_ctl_find_id(card, &info.id);
+	_kctl = snd_ctl_find_id(card, &info->id);
 	err = 0;
 	if (_kctl) {
 		if (replace)
@@ -886,67 +886,50 @@ static int snd_ctl_elem_add(snd_ctl_file_t *file, snd_ctl_elem_info_t __user *_i
 	up_write(&card->controls_rwsem);
 	if (err < 0)
 		return err;
-	memcpy(&kctl.id, &info.id, sizeof(info.id));
-	kctl.count = info.owner ? info.owner : 1;
+	memcpy(&kctl.id, &info->id, sizeof(info->id));
+	kctl.count = info->owner ? info->owner : 1;
 	access |= SNDRV_CTL_ELEM_ACCESS_USER;
 	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;
-	extra_size = 0;
-	switch (info.type) {
+	switch (info->type) {
 	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
 		private_size = sizeof(char);
-		if (info.count > 128)
+		if (info->count > 128)
 			return -EINVAL;
 		break;
 	case SNDRV_CTL_ELEM_TYPE_INTEGER:
 		private_size = sizeof(long);
-		if (info.count > 128)
+		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)
+		if (info->count > 64)
 			return -EINVAL;
-		if (info.value.enumerated.items > 128)
-			return -EINVAL;
-		extra_size = info.value.enumerated.items * 64;
 		break;
 	case SNDRV_CTL_ELEM_TYPE_BYTES:
 		private_size = sizeof(unsigned char);
-		if (info.count > 512)
+		if (info->count > 512)
 			return -EINVAL;
 		break;
 	case SNDRV_CTL_ELEM_TYPE_IEC958:
 		private_size = sizeof(struct sndrv_aes_iec958);
-		if (info.count != 1)
+		if (info->count != 1)
 			return -EINVAL;
 		break;
 	default:
 		return -EINVAL;
 	}
-	private_size *= info.count;
-	ue = kcalloc(1, sizeof(struct user_element) + private_size + extra_size, GFP_KERNEL);
+	private_size *= info->count;
+	ue = kcalloc(1, sizeof(struct user_element) + private_size, GFP_KERNEL);
 	if (ue == NULL)
 		return -ENOMEM;
-	ue->info = info;
+	ue->info = *info;
 	ue->elem_data = (char *)ue + sizeof(ue);
 	ue->elem_data_size = private_size;
-	if (extra_size) {
-		ue->priv_data = (char *)ue + sizeof(ue) + private_size;
-		ue->priv_data_size = extra_size;
-		if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
-			if (copy_from_user(ue->priv_data, *(char __user **)info.value.enumerated.name, extra_size))
-				return -EFAULT;
-		}
-	}
 	kctl.private_free = snd_ctl_elem_user_free;
 	_kctl = snd_ctl_new(&kctl, access);
 	if (_kctl == NULL) {
@@ -969,6 +952,14 @@ static int snd_ctl_elem_add(snd_ctl_file_t *file, snd_ctl_elem_info_t __user *_i
 	return 0;
 }
 
+static int snd_ctl_elem_add_user(snd_ctl_file_t *file, snd_ctl_elem_info_t __user *_info, int replace)
+{
+	snd_ctl_elem_info_t info;
+	if (copy_from_user(&info, _info, sizeof(info)))
+		return -EFAULT;
+	return snd_ctl_elem_add(file, &info, replace);
+}
+
 static int snd_ctl_elem_remove(snd_ctl_file_t *file, snd_ctl_elem_id_t __user *_id)
 {
 	snd_ctl_elem_id_t id;
@@ -1039,8 +1030,7 @@ static int snd_ctl_set_power_state(snd_card_t *card, unsigned int power_state)
 }
 #endif
 
-static inline int _snd_ctl_ioctl(struct inode *inode, struct file *file,
-				 unsigned int cmd, unsigned long arg)
+static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	snd_ctl_file_t *ctl;
 	snd_card_t *card;
@@ -1061,7 +1051,7 @@ static inline int _snd_ctl_ioctl(struct inode *inode, struct file *file,
 	case SNDRV_CTL_IOCTL_ELEM_LIST:
 		return snd_ctl_elem_list(ctl->card, argp);
 	case SNDRV_CTL_IOCTL_ELEM_INFO:
-		return snd_ctl_elem_info(ctl, argp);
+		return snd_ctl_elem_info_user(ctl, argp);
 	case SNDRV_CTL_IOCTL_ELEM_READ:
 		return snd_ctl_elem_read_user(ctl->card, argp);
 	case SNDRV_CTL_IOCTL_ELEM_WRITE:
@@ -1071,7 +1061,7 @@ static inline int _snd_ctl_ioctl(struct inode *inode, struct file *file,
 	case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
 		return snd_ctl_elem_unlock(ctl, argp);
 	case SNDRV_CTL_IOCTL_ELEM_ADD:
-		return snd_ctl_elem_add(ctl, argp, 0);
+		return snd_ctl_elem_add_user(ctl, argp, 0);
 	case SNDRV_CTL_IOCTL_ELEM_REPLACE:
 		return snd_ctl_elem_add(ctl, argp, 1);
 	case SNDRV_CTL_IOCTL_ELEM_REMOVE:
@@ -1113,17 +1103,6 @@ static inline int _snd_ctl_ioctl(struct inode *inode, struct file *file,
 	return -ENOTTY;
 }
 
-/* FIXME: need to unlock BKL to allow preemption */
-static int snd_ctl_ioctl(struct inode *inode, struct file *file,
-			 unsigned int cmd, unsigned long arg)
-{
-	int err;
-	unlock_kernel();
-	err = _snd_ctl_ioctl(inode, file, cmd, arg);
-	lock_kernel();
-	return err;
-}
-
 static ssize_t snd_ctl_read(struct file *file, char __user *buffer, size_t count, loff_t * offset)
 {
 	snd_ctl_file_t *ctl;
@@ -1199,7 +1178,7 @@ static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
  * register the device-specific control-ioctls.
  * called from each device manager like pcm.c, hwdep.c, etc.
  */
-int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
+static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
 {
 	snd_kctl_ioctl_t *pn;
 
@@ -1208,22 +1187,34 @@ int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
 		return -ENOMEM;
 	pn->fioctl = fcn;
 	down_write(&snd_ioctl_rwsem);
-	list_add_tail(&pn->list, &snd_control_ioctls);
+	list_add_tail(&pn->list, lists);
 	up_write(&snd_ioctl_rwsem);
 	return 0;
 }
 
+int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
+{
+	return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
+}
+
+#ifdef CONFIG_COMPAT
+int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
+{
+	return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
+}
+#endif
+
 /*
  * de-register the device-specific control-ioctls.
  */
-int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
+static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
 {
 	struct list_head *list;
 	snd_kctl_ioctl_t *p;
 
 	snd_runtime_check(fcn != NULL, return -EINVAL);
 	down_write(&snd_ioctl_rwsem);
-	list_for_each(list, &snd_control_ioctls) {
+	list_for_each(list, lists) {
 		p = list_entry(list, snd_kctl_ioctl_t, list);
 		if (p->fioctl == fcn) {
 			list_del(&p->list);
@@ -1237,6 +1228,19 @@ int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
 	return -EINVAL;
 }
 
+int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
+{
+	return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
+}
+
+#ifdef CONFIG_COMPAT
+int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
+{
+	return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
+}
+
+#endif
+
 static int snd_ctl_fasync(int fd, struct file * file, int on)
 {
 	snd_ctl_file_t *ctl;
@@ -1248,6 +1252,15 @@ static int snd_ctl_fasync(int fd, struct file * file, int on)
 	return 0;
 }
 
+/*
+ * ioctl32 compat
+ */
+#ifdef CONFIG_COMPAT
+#include "control_compat.c"
+#else
+#define snd_ctl_ioctl_compat	NULL
+#endif
+
 /*
  *  INIT PART
  */
@@ -1259,7 +1272,8 @@ static struct file_operations snd_ctl_f_ops =
 	.open =		snd_ctl_open,
 	.release =	snd_ctl_release,
 	.poll =		snd_ctl_poll,
-	.ioctl =	snd_ctl_ioctl,
+	.unlocked_ioctl =	snd_ctl_ioctl,
+	.compat_ioctl =	snd_ctl_ioctl_compat,
 	.fasync =	snd_ctl_fasync,
 };
 

sound/core/control_compat.c

+/*
+ * compat ioctls for control API
+ *
+ *   Copyright (c) by Takashi Iwai <tiwai@suse.de>
+ *
+ *   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
+ */
+
+/* this file included from control.c */
+
+#include <linux/compat.h>
+
+struct sndrv_ctl_elem_list32 {
+	u32 offset;
+	u32 space;
+	u32 used;
+	u32 count;
+	u32 pids;
+	unsigned char reserved[50];
+} /* don't set packed attribute here */;
+
+static int snd_ctl_elem_list_compat(snd_card_t *card, struct sndrv_ctl_elem_list32 __user *data32)
+{
+	struct sndrv_ctl_elem_list __user *data;
+	compat_caddr_t ptr;
+	int err;
+
+	data = compat_alloc_user_space(sizeof(*data));
+
+	/* offset, space, used, count */
+	if (copy_in_user(data, data32, 4 * sizeof(u32)))
+		return -EFAULT;
+	/* pids */
+	if (get_user(ptr, &data32->pids) ||
+	    put_user(compat_ptr(ptr), &data->pids))
+		return -EFAULT;
+	err = snd_ctl_elem_list(card, data);
+	if (err < 0)
+		return err;
+	/* copy the result */
+	if (copy_in_user(data32, data, 4 * sizeof(u32)))
+		return -EFAULT;
+	return 0;
+}
+
+/*
+ * control element info
+ * it uses union, so the things are not easy..
+ */
+
+struct sndrv_ctl_elem_info32 {
+	struct sndrv_ctl_elem_id id; // the size of struct is same
+	s32 type;
+	u32 access;
+	u32 count;
+	s32 owner;
+	union {
+		struct {
+			s32 min;
+			s32 max;
+			s32 step;
+		} integer;
+		struct {
+			u64 min;
+			u64 max;
+			u64 step;
+		} integer64;
+		struct {
+			u32 items;
+			u32 item;
+			char name[64];
+		} enumerated;
+		unsigned char reserved[128];
+	} value;
+	unsigned char reserved[64];
+} __attribute__((packed));
+
+static int snd_ctl_elem_info_compat(snd_ctl_file_t *ctl, struct sndrv_ctl_elem_info32 __user *data32)
+{
+	struct sndrv_ctl_elem_info *data;
+	int err;
+
+	data = kcalloc(1, sizeof(*data), GFP_KERNEL);
+	if (! data)
+		return -ENOMEM;
+
+	err = -EFAULT;
+	/* copy id */
+	if (copy_from_user(&data->id, &data32->id, sizeof(data->id)))
+		goto error;
+	/* we need to copy the item index.
+	 * hope this doesn't break anything..
+	 */
+	if (get_user(data->value.enumerated.item, &data32->value.enumerated.item))
+		goto error;
+	err = snd_ctl_elem_info(ctl, data);
+	if (err < 0)
+		goto error;
+	/* restore info to 32bit */
+	err = -EFAULT;
+	/* id, type, access, count */
+	if (copy_to_user(&data32->id, &data->id, sizeof(data->id)) ||
+	    copy_to_user(&data32->type, &data->type, 3 * sizeof(u32)))
+		goto error;
+	if (put_user(data->owner, &data32->owner))
+		goto error;
+	switch (data->type) {
+	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
+	case SNDRV_CTL_ELEM_TYPE_INTEGER:
+		if (put_user(data->value.integer.min, &data32->value.integer.min) ||
+		    put_user(data->value.integer.max, &data32->value.integer.max) ||
+		    put_user(data->value.integer.step, &data32->value.integer.step))
+			goto error;
+		break;
+	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
+		if (copy_to_user(&data32->value.integer64,
+				 &data->value.integer64,
+				 sizeof(data->value.integer64)))
+			goto error;
+		break;
+	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
+		if (copy_to_user(&data32->value.enumerated,
+				 &data->value.enumerated,
+				 sizeof(data->value.enumerated)))
+			goto error;
+		break;
+	default:
+		break;
+	}
+	err = 0;
+ error:
+	kfree(data);
+	return err;
+}
+
+/* read / write */
+struct sndrv_ctl_elem_value32 {
+	struct sndrv_ctl_elem_id id;
+	unsigned int indirect;	/* bit-field causes misalignment */
+        union {
+		s32 integer[128];
+		unsigned char data[512];
+#ifndef CONFIG_X86_64
+		s64 integer64[64];
+#endif
+        } value;
+        unsigned char reserved[128];
+};
+
+
+/* get the value type and count of the control */
+static int get_ctl_type(snd_card_t *card, snd_ctl_elem_id_t *id, int *countp)
+{
+	snd_kcontrol_t *kctl;
+	snd_ctl_elem_info_t info;
+	int err;
+
+	down_read(&card->controls_rwsem);
+	kctl = snd_ctl_find_id(card, id);
+	if (! kctl) {
+		up_read(&card->controls_rwsem);
+		return -ENXIO;
+	}
+	info.id = *id;
+	err = kctl->info(kctl, &info);
+	up_read(&card->controls_rwsem);
+	if (err >= 0) {
+		err = info.type;
+		*countp = info.count;
+	}
+	return err;
+}
+
+static int get_elem_size(int type, int count)
+{
+	switch (type) {
+	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
+		return sizeof(s64) * count;
+	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
+		return sizeof(int) * count;
+	case SNDRV_CTL_ELEM_TYPE_BYTES:
+		return 512;
+	case SNDRV_CTL_ELEM_TYPE_IEC958:
+		return sizeof(struct sndrv_aes_iec958);
+	default:
+		return -1;
+	}
+}
+
+static int copy_ctl_value_from_user(snd_card_t *card,
+				    struct sndrv_ctl_elem_value *data,
+				    struct sndrv_ctl_elem_value32 __user *data32,
+				    int *typep, int *countp)
+{
+	int i, type, count, size;
+	unsigned int indirect;
+
+	if (copy_from_user(&data->id, &data32->id, sizeof(data->id)))
+		return -EFAULT;
+	if (get_user(indirect, &data32->indirect))
+		return -EFAULT;
+	if (indirect)
+		return -EINVAL;
+	type = get_ctl_type(card, &data->id, &count);
+	if (type < 0)
+		return type;
+
+	if (type == SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
+	    type == SNDRV_CTL_ELEM_TYPE_INTEGER) {
+		for (i = 0; i < count; i++) {
+			int val;
+			if (get_user(val, &data32->value.integer[i]))
+				return -EFAULT;
+			data->value.integer.value[i] = val;
+		}
+	} else {
+		size = get_elem_size(type, count);
+		if (size < 0) {
+			printk(KERN_ERR "snd_ioctl32_ctl_elem_value: unknown type %d\n", type);
+			return -EINVAL;
+		}
+		if (copy_from_user(data->value.bytes.data,
+				   data32->value.data, size))
+			return -EFAULT;
+	}
+
+	*typep = type;
+	*countp = count;
+	return 0;
+}
+
+/* restore the value to 32bit */
+static int copy_ctl_value_to_user(struct sndrv_ctl_elem_value32 __user *data32,
+				  struct sndrv_ctl_elem_value *data,
+				  int type, int count)
+{
+	int i, size;
+
+	if (type == SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
+	    type == SNDRV_CTL_ELEM_TYPE_INTEGER) {
+		for (i = 0; i < count; i++) {
+			int val;
+			val = data->value.integer.value[i];
+			if (put_user(val, &data32->value.integer[i]))
+				return -EFAULT;
+		}
+	} else {
+		size = get_elem_size(type, count);
+		if (copy_to_user(data32->value.data,
+				 data->value.bytes.data, size))
+			return -EFAULT;
+	}
+	return 0;
+}
+
+static int snd_ctl_elem_read_user_compat(snd_card_t *card, 
+					 struct sndrv_ctl_elem_value32 __user *data32)
+{
+	struct sndrv_ctl_elem_value *data;
+	int err, type, count;
+
+	data = kcalloc(1, sizeof(*data), GFP_KERNEL);
+	if (data == NULL)
+		return -ENOMEM;
+
+	if ((err = copy_ctl_value_from_user(card, data, data32, &type, &count)) < 0)
+		goto error;
+	if ((err = snd_ctl_elem_read(card, data)) < 0)
+		goto error;
+	err = copy_ctl_value_to_user(data32, data, type, count);
+ error:
+	kfree(data);
+	return err;
+}
+
+static int snd_ctl_elem_write_user_compat(snd_ctl_file_t *file,
+					  struct sndrv_ctl_elem_value32 __user *data32)
+{
+	struct sndrv_ctl_elem_value *data;
+	int err, type, count;
+
+	data = kcalloc(1, sizeof(*data), GFP_KERNEL);
+	if (data == NULL)
+		return -ENOMEM;
+
+	if ((err = copy_ctl_value_from_user(file->card, data, data32, &type, &count)) < 0)
+		goto error;
+	if ((err = snd_ctl_elem_write(file->card, file, data)) < 0)
+		goto error;
+	err = copy_ctl_value_to_user(data32, data, type, count);
+ error:
+	kfree(data);
+	return err;
+}
+
+/* add or replace a user control */
+static int snd_ctl_elem_add_compat(snd_ctl_file_t *file,
+				   struct sndrv_ctl_elem_info32 __user *data32,
+				   int replace)
+{
+	struct sndrv_ctl_elem_info *data;
+	int err;
+
+	data = kcalloc(1, sizeof(*data), GFP_KERNEL);
+	if (! data)
+		return -ENOMEM;
+
+	err = -EFAULT;
+	/* id, type, access, count */ \
+	if (copy_from_user(&data->id, &data32->id, sizeof(data->id)) ||
+	    copy_from_user(&data->type, &data32->type, 3 * sizeof(u32)))
+		goto error;
+	if (get_user(data->owner, &data32->owner) ||
+	    get_user(data->type, &data32->type))
+		goto error;
+	switch (data->type) {
+	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
+	case SNDRV_CTL_ELEM_TYPE_INTEGER:
+		if (get_user(data->value.integer.min, &data32->value.integer.min) ||
+		    get_user(data->value.integer.max, &data32->value.integer.max) ||
+		    get_user(data->value.integer.step, &data32->value.integer.step))
+			goto error;
+		break;
+	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
+		if (copy_from_user(&data->value.integer64,
+				   &data32->value.integer64,
+				   sizeof(data->value.integer64)))
+			goto error;
+		break;
+	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
+		if (copy_from_user(&data->value.enumerated,
+				   &data32->value.enumerated,
+				   sizeof(data->value.enumerated)))
+			goto error;
+		break;
+	default:
+		break;
+	}
+	err = snd_ctl_elem_add(file, data, replace);
+ error:
+	kfree(data);
+	return err;
+}  
+
+enum {
+	SNDRV_CTL_IOCTL_ELEM_LIST32 = _IOWR('U', 0x10, struct sndrv_ctl_elem_list32),
+	SNDRV_CTL_IOCTL_ELEM_INFO32 = _IOWR('U', 0x11, struct sndrv_ctl_elem_info32),
+	SNDRV_CTL_IOCTL_ELEM_READ32 = _IOWR('U', 0x12, struct sndrv_ctl_elem_value32),
+	SNDRV_CTL_IOCTL_ELEM_WRITE32 = _IOWR('U', 0x13, struct sndrv_ctl_elem_value32),
+	SNDRV_CTL_IOCTL_ELEM_ADD32 = _IOWR('U', 0x17, struct sndrv_ctl_elem_info32),
+	SNDRV_CTL_IOCTL_ELEM_REPLACE32 = _IOWR('U', 0x18, struct sndrv_ctl_elem_info32),
+};
+
+static inline long snd_ctl_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	snd_ctl_file_t *ctl;
+	struct list_head *list;
+	void __user *argp = compat_ptr(arg);
+	int err;
+
+	ctl = file->private_data;
+	snd_assert(ctl && ctl->card, return -ENXIO);
+
+	switch (cmd) {
+	case SNDRV_CTL_IOCTL_PVERSION:
+	case SNDRV_CTL_IOCTL_CARD_INFO:
+	case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
+	case SNDRV_CTL_IOCTL_POWER:
+	case SNDRV_CTL_IOCTL_POWER_STATE:
+	case SNDRV_CTL_IOCTL_ELEM_LOCK:
+	case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
+		return snd_ctl_ioctl(file, cmd, (unsigned long)argp);
+	case SNDRV_CTL_IOCTL_ELEM_LIST32:
+		return snd_ctl_elem_list_compat(ctl->card, argp);
+	case SNDRV_CTL_IOCTL_ELEM_INFO32:
+		return snd_ctl_elem_info_compat(ctl, argp);
+	case SNDRV_CTL_IOCTL_ELEM_READ32:
+		return snd_ctl_elem_read_user_compat(ctl->card, argp);
+	case SNDRV_CTL_IOCTL_ELEM_WRITE32:
+		return snd_ctl_elem_write_user_compat(ctl, argp);
+	case SNDRV_CTL_IOCTL_ELEM_ADD32:
+		return snd_ctl_elem_add_compat(ctl, argp, 0);
+	case SNDRV_CTL_IOCTL_ELEM_REPLACE32:
+		return snd_ctl_elem_add_compat(ctl, argp, 1);
+	}
+
+	down_read(&snd_ioctl_rwsem);
+	list_for_each(list, &snd_control_compat_ioctls) {
+		snd_kctl_ioctl_t *p = list_entry(list, snd_kctl_ioctl_t, list);
+		if (p->fioctl) {
+			err = p->fioctl(ctl->card, ctl, cmd, arg);
+			if (err != -ENOIOCTLCMD) {
+				up_read(&snd_ioctl_rwsem);
+				return err;
+			}
+		}
+	}
+	up_read(&snd_ioctl_rwsem);
+	return -ENOIOCTLCMD;
+}