Re: [PATCH v3 11/41] media/v4l2-core/mm: convert put_page() to put_user_page*()

[Hans Verkuil]

On 8/7/19 3:33 AM, john.hubbard@xxxxxxxxx wrote:
> From: John Hubbard <jhubbard@xxxxxxxxxx>
> 
> For pages that were retained via get_user_pages*(), release those pages
> via the new put_user_page*() routines, instead of via put_page() or
> release_pages().
> 
> This is part a tree-wide conversion, as described in commit fc1d8e7cca2d
> ("mm: introduce put_user_page*(), placeholder versions").
> 
> Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> Cc: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> Cc: Jan Kara <jack@xxxxxxx>
> Cc: Robin Murphy <robin.murphy@xxxxxxx>
> Cc: Souptick Joarder <jrdr.linux@xxxxxxxxx>
> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> Cc: linux-media@xxxxxxxxxxxxxxx
> Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>

Acked-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>

> ---
>  drivers/media/v4l2-core/videobuf-dma-sg.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/videobuf-dma-sg.c b/drivers/media/v4l2-core/videobuf-dma-sg.c
> index 66a6c6c236a7..d6eeb437ec19 100644
> --- a/drivers/media/v4l2-core/videobuf-dma-sg.c
> +++ b/drivers/media/v4l2-core/videobuf-dma-sg.c
> @@ -349,8 +349,7 @@ int videobuf_dma_free(struct videobuf_dmabuf *dma)
>  	BUG_ON(dma->sglen);
>  
>  	if (dma->pages) {
> -		for (i = 0; i < dma->nr_pages; i++)
> -			put_page(dma->pages[i]);
> +		put_user_pages(dma->pages, dma->nr_pages);
>  		kfree(dma->pages);
>  		dma->pages = NULL;
>  	}
>