[alsa-devel] [PATCH 12/27] ALSA: seq: optimize get/set_client_info function to new design

[Takashi Sakamoto]

In former commit, actual operations of each ioctl command get argument
in kernel space. Copying from/to user space is performed outside of
the function.

This commit optimizes to the new design.

Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
---
 sound/core/seq/seq_clientmgr.c | 34 +++++++++++++---------------------
 1 file changed, 13 insertions(+), 21 deletions(-)

diff --git a/sound/core/seq/seq_clientmgr.c b/sound/core/seq/seq_clientmgr.c
index 59de125..e346786 100644
--- a/sound/core/seq/seq_clientmgr.c
+++ b/sound/core/seq/seq_clientmgr.c
@@ -1210,51 +1210,43 @@ static void get_client_info(struct snd_seq_client *cptr,
 }
 
 static int snd_seq_ioctl_get_client_info(struct snd_seq_client *client,
-					 void __user *arg)
+					 void *arg)
 {
+	struct snd_seq_client_info *client_info = arg;
 	struct snd_seq_client *cptr;
-	struct snd_seq_client_info client_info;
-
-	if (copy_from_user(&client_info, arg, sizeof(client_info)))
-		return -EFAULT;
 
 	/* requested client number */
-	cptr = snd_seq_client_use_ptr(client_info.client);
+	cptr = snd_seq_client_use_ptr(client_info->client);
 	if (cptr == NULL)
 		return -ENOENT;		/* don't change !!! */
 
-	get_client_info(cptr, &client_info);
+	get_client_info(cptr, client_info);
 	snd_seq_client_unlock(cptr);
 
-	if (copy_to_user(arg, &client_info, sizeof(client_info)))
-		return -EFAULT;
 	return 0;
 }
 
 
 /* CLIENT_INFO ioctl() */
 static int snd_seq_ioctl_set_client_info(struct snd_seq_client *client,
-					 void __user *arg)
+					 void *arg)
 {
-	struct snd_seq_client_info client_info;
-
-	if (copy_from_user(&client_info, arg, sizeof(client_info)))
-		return -EFAULT;
+	struct snd_seq_client_info *client_info = arg;
 
 	/* it is not allowed to set the info fields for an another client */
-	if (client->number != client_info.client)
+	if (client->number != client_info->client)
 		return -EPERM;
 	/* also client type must be set now */
-	if (client->type != client_info.type)
+	if (client->type != client_info->type)
 		return -EINVAL;
 
 	/* fill the info fields */
-	if (client_info.name[0])
-		strlcpy(client->name, client_info.name, sizeof(client->name));
+	if (client_info->name[0])
+		strlcpy(client->name, client_info->name, sizeof(client->name));
 
-	client->filter = client_info.filter;
-	client->event_lost = client_info.event_lost;
-	memcpy(client->event_filter, client_info.event_filter, 32);
+	client->filter = client_info->filter;
+	client->event_lost = client_info->event_lost;
+	memcpy(client->event_filter, client_info->event_filter, 32);
 
 	return 0;
 }
-- 
2.7.4