Re: [PATCH 1/3] efi/efi_test: use memdup_user() as a cleanup

[Matt Fleming <matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>]

On Mon, 26 Sep, at 11:14:49AM, Ivan Hu wrote:
> Cleanup the warning,
> drivers/firmware/efi/test/efi_test.c:269:8-15: WARNING opportunity for
> memdup_user
> 
> Use memdup_user rather than duplicating its implementation
> This is a little bit restricted to reduce false positives
 
I don't understand this sentence. What restriction are you talking
about?

> Generated by: coccinelle/api/memdup_user.coc
> 
> Signed-off-by: Ivan Hu <ivan.hu-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>
> ---
>  drivers/firmware/efi/test/efi_test.c | 10 +++-------
>  1 file changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/firmware/efi/test/efi_test.c b/drivers/firmware/efi/test/efi_test.c
> index f61bb52..5602c46 100644
> --- a/drivers/firmware/efi/test/efi_test.c
> +++ b/drivers/firmware/efi/test/efi_test.c
> @@ -266,14 +266,10 @@ static long efi_runtime_set_variable(unsigned long arg)
>  			return rv;
>  	}
>  
> -	data = kmalloc(setvariable.data_size, GFP_KERNEL);
> -	if (!data) {
> +	data = memdup_user(setvariable.data, setvariable.data_size);
> +	if (IS_ERR(data)) {
>  		kfree(name);
> -		return -ENOMEM;
> -	}
> -	if (copy_from_user(data, setvariable.data, setvariable.data_size)) {
> -		rv = -EFAULT;
> -		goto out;
> +		return PTR_ERR(data);
>  	}
>  
>  	status = efi.set_variable(name, &vendor_guid,
> -- 
> 1.9.1
>