[alsa-devel] [PATCH 33/39] ALSA: seq: optimize get_client_pool function to new design

Takashi Sakamoto o-takashi at sakamocchi.jp
Sun Aug 7 11:49:09 CEST 2016


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, 14 insertions(+), 20 deletions(-)

diff --git a/sound/core/seq/seq_clientmgr.c b/sound/core/seq/seq_clientmgr.c
index 6c1b406..2e63082 100644
--- a/sound/core/seq/seq_clientmgr.c
+++ b/sound/core/seq/seq_clientmgr.c
@@ -1790,37 +1790,31 @@ static int seq_ioctl_set_queue_client(struct snd_seq_client *client, void *arg)
 
 
 /* GET_CLIENT_POOL ioctl() */
-static int seq_ioctl_get_client_pool(struct snd_seq_client *client,
-				     void __user *arg)
+static int seq_ioctl_get_client_pool(struct snd_seq_client *client, void *arg)
 {
-	struct snd_seq_client_pool info;
+	struct snd_seq_client_pool *info = arg;
 	struct snd_seq_client *cptr;
 
-	if (copy_from_user(&info, arg, sizeof(info)))
-		return -EFAULT;
-
-	cptr = snd_seq_client_use_ptr(info.client);
+	cptr = snd_seq_client_use_ptr(info->client);
 	if (cptr == NULL)
 		return -ENOENT;
-	memset(&info, 0, sizeof(info));
-	info.client = cptr->number;
-	info.output_pool = cptr->pool->size;
-	info.output_room = cptr->pool->room;
-	info.output_free = info.output_pool;
-	info.output_free = snd_seq_unused_cells(cptr->pool);
+	memset(info, 0, sizeof(*info));
+	info->client = cptr->number;
+	info->output_pool = cptr->pool->size;
+	info->output_room = cptr->pool->room;
+	info->output_free = info->output_pool;
+	info->output_free = snd_seq_unused_cells(cptr->pool);
 	if (cptr->type == USER_CLIENT) {
-		info.input_pool = cptr->data.user.fifo_pool_size;
-		info.input_free = info.input_pool;
+		info->input_pool = cptr->data.user.fifo_pool_size;
+		info->input_free = info->input_pool;
 		if (cptr->data.user.fifo)
-			info.input_free = snd_seq_unused_cells(cptr->data.user.fifo->pool);
+			info->input_free = snd_seq_unused_cells(cptr->data.user.fifo->pool);
 	} else {
-		info.input_pool = 0;
-		info.input_free = 0;
+		info->input_pool = 0;
+		info->input_free = 0;
 	}
 	snd_seq_client_unlock(cptr);
 	
-	if (copy_to_user(arg, &info, sizeof(info)))
-		return -EFAULT;
 	return 0;
 }
 
-- 
2.7.4



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