[16/37] drivers/media/video/uvc: Use kmemdup
Commit Message
From: 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/)
// <smpl>
@@
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);
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
---
drivers/media/video/uvc/uvc_driver.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
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Comments
Hi Julia,
Thanks for the patch.
On Saturday 15 May 2010 23:17:59 Julia Lawall wrote:
> From: 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/)
>
> // <smpl>
> @@
> 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);
> // </smpl>
>
> Signed-off-by: Julia Lawall <julia@diku.dk>
>
> ---
> drivers/media/video/uvc/uvc_driver.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff -u -p a/drivers/media/video/uvc/uvc_driver.c
> b/drivers/media/video/uvc/uvc_driver.c ---
> 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 uv
> }
> streaming->header.bControlSize = n;
>
> - streaming->header.bmaControls = kmalloc(p*n, GFP_KERNEL);
> + streaming->header.bmaControls = kmemdup(&buffer[size], p * n,
I'm puzzled, how did the above semantic patch transform 'p*n' into 'p * n' ?
As a side note, keeping 'p*n' would have allowed the statement to fit in one
line :-)
> + 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];
@@ -637,14 +637,13 @@ static int uvc_parse_streaming(struct uv
}
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];