Jul 01 2010

V4L/DVB: drivers/media/video/uvc: Use kmemdup 

Author: Julia Lawall <julia@diku.dk>

Use kmemdup when some other buffer is immediately copied into the
allocated region.

A simplified version of the semantic patch that makes this change is as
follows: (http://coccinelle.lip6.fr/)

// 
@@
expression from,to,size,flag;
statement S;
@@

-  to = \(kmalloc\|kzalloc\)(size,flag);
+  to = kmemdup(from,size,flag);
   if (to==NULL || ...) S
-  memcpy(to, from, size);
// 

Signed-off-by: Julia Lawall 
Signed-off-by: Douglas Schilling Landgraf 
Signed-off-by: Mauro Carvalho Chehab 

---
 drivers/media/video/uvc/uvc_driver.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)
 
diff --git a/drivers/media/video/uvc/uvc_driver.c b/drivers/media/video/uvc/uvc_driver.c
index 838b56f..45aac10 100644
--- a/drivers/media/video/uvc/uvc_driver.c
+++ b/drivers/media/video/uvc/uvc_driver.c
@@ -637,14 +637,13 @@ static int uvc_parse_streaming(struct uvc_device *dev,
 	}
 	streaming->header.bControlSize = n;
 
-	streaming->header.bmaControls = kmalloc(p*n, GFP_KERNEL);
+	streaming->header.bmaControls = kmemdup(&buffer[size], p * n,
+						GFP_KERNEL);
 	if (streaming->header.bmaControls == NULL) {
 		ret = -ENOMEM;
 		goto error;
 	}
 
-	memcpy(streaming->header.bmaControls, &buffer[size], p*n);
-
 	buflen -= buffer[0];
 	buffer += buffer[0];

qlambert