Re: [PATCH -next v2] drm/imagination: Use memdup_user() helper

[Frank Binns]

On Mon, 2024-09-02 at 10:33 +0800, Jinjie Ruan wrote:
> Switching to memdup_user(), which combines kmalloc() and copy_from_user(),
> and it can simplfy code.
> 

Reviewed-by: Frank Binns <frank.binns@xxxxxxxxxx>

> Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
> Suggested-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> ---
> v2:
> - Add suggested-by.
> - Simplify the code.
> ---
>  drivers/gpu/drm/imagination/pvr_context.c | 18 +++---------------
>  1 file changed, 3 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/gpu/drm/imagination/pvr_context.c b/drivers/gpu/drm/imagination/pvr_context.c
> index eded5e955cc0..98327f9bbd9c 100644
> --- a/drivers/gpu/drm/imagination/pvr_context.c
> +++ b/drivers/gpu/drm/imagination/pvr_context.c
> @@ -69,24 +69,12 @@ process_static_context_state(struct pvr_device *pvr_dev, const struct pvr_stream
>  	void *stream;
>  	int err;
>  
> -	stream = kzalloc(stream_size, GFP_KERNEL);
> -	if (!stream)
> -		return -ENOMEM;
> -
> -	if (copy_from_user(stream, u64_to_user_ptr(stream_user_ptr), stream_size)) {
> -		err = -EFAULT;
> -		goto err_free;
> -	}
> +	stream = memdup_user(u64_to_user_ptr(stream_user_ptr), stream_size);
> +	if (IS_ERR(stream))
> +		return PTR_ERR(stream);
>  
>  	err = pvr_stream_process(pvr_dev, cmd_defs, stream, stream_size, dest);
> -	if (err)
> -		goto err_free;
> -
> -	kfree(stream);
> -
> -	return 0;
>  
> -err_free:
>  	kfree(stream);
>  
>  	return err;