[alsa-devel] [PATCH 10/27] ALSA: seq: optimize system_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 | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/sound/core/seq/seq_clientmgr.c b/sound/core/seq/seq_clientmgr.c
index 9cf5a82..624d001 100644
--- a/sound/core/seq/seq_clientmgr.c
+++ b/sound/core/seq/seq_clientmgr.c
@@ -1131,21 +1131,19 @@ static int seq_ioctl_client_id(struct snd_seq_client *client, void *arg)
 }
 
 /* SYSTEM_INFO ioctl() */
-static int snd_seq_ioctl_system_info(struct snd_seq_client *client, void __user *arg)
+static int snd_seq_ioctl_system_info(struct snd_seq_client *client, void *arg)
 {
-	struct snd_seq_system_info info;
+	struct snd_seq_system_info *info = arg;
 
-	memset(&info, 0, sizeof(info));
+	memset(info, 0, sizeof(*info));
 	/* fill the info fields */
-	info.queues = SNDRV_SEQ_MAX_QUEUES;
-	info.clients = SNDRV_SEQ_MAX_CLIENTS;
-	info.ports = SNDRV_SEQ_MAX_PORTS;
-	info.channels = 256;	/* fixed limit */
-	info.cur_clients = client_usage.cur;
-	info.cur_queues = snd_seq_queue_get_cur_queues();
+	info->queues = SNDRV_SEQ_MAX_QUEUES;
+	info->clients = SNDRV_SEQ_MAX_CLIENTS;
+	info->ports = SNDRV_SEQ_MAX_PORTS;
+	info->channels = 256;	/* fixed limit */
+	info->cur_clients = client_usage.cur;
+	info->cur_queues = snd_seq_queue_get_cur_queues();
 
-	if (copy_to_user(arg, &info, sizeof(info)))
-		return -EFAULT;
 	return 0;
 }
 
-- 
2.7.4