ACK: [PATCH 1/4] efi_runtime: add VariableNameSize return when getting the EFI_BUFFER_TOO_SMALL

[Colin Ian King]

On 22/08/16 10:08, Ivan Hu wrote:
> VariableNameSize is required to return when getting the EFI_BUFFER_TOO_SMALL
> for user to obtain and set the required data buffer size on GetNextVariableName
> runtime service.
> 
> Signed-off-by: Ivan Hu <ivan.hu at canonical.com>
> ---
>  efi_runtime/efi_runtime.c | 52 ++++++++++++++++++++++++++++++-----------------
>  1 file changed, 33 insertions(+), 19 deletions(-)
> 
> diff --git a/efi_runtime/efi_runtime.c b/efi_runtime/efi_runtime.c
> index 5ac9781..c60a6d8 100644
> --- a/efi_runtime/efi_runtime.c
> +++ b/efi_runtime/efi_runtime.c
> @@ -334,7 +334,7 @@ static long efi_runtime_get_time(unsigned long arg)
>  			return -EFAULT;
>  	}
>  	if (gettime.time) {
> -		if(copy_to_user(gettime.time, &efi_time, sizeof(efi_time_t)))
> +		if (copy_to_user(gettime.time, &efi_time, sizeof(efi_time_t)))
>  			return -EFAULT;
>  	}
>  
> @@ -488,33 +488,47 @@ static long efi_runtime_get_nextvariablename(unsigned long arg)
>  
>  	status = efi.get_next_variable(ns, name, vd);
>  
> -	if (name) {
> -		rv = copy_ucs2_to_user_len(
> -				getnextvariablename.variable_name,
> -				name, prev_name_size);
> -		kfree(name);
> -		if (rv)
> -			return -EFAULT;
> +	if (put_user(status, getnextvariablename.status)) {
> +		rv = -EFAULT;
> +		goto out;
>  	}
>  
> -	if (put_user(status, getnextvariablename.status))
> -		return -EFAULT;
> +	if (status != EFI_SUCCESS) {
> +		if (status == EFI_BUFFER_TOO_SMALL) {
> +			if (ns && put_user(*ns,
> +				getnextvariablename.variable_name_size)) {
> +				rv = -EFAULT;
> +				goto out;
> +			}
> +		}
> +		rv = -EINVAL;
> +		goto out;
> +	}
> +
> +	if (name) {
> +		if (copy_ucs2_to_user_len(getnextvariablename.variable_name,
> +						name, prev_name_size)) {
> +			rv = -EFAULT;
> +			goto out;
> +		}
> +	}
>  
>  	if (ns) {
> -		if (put_user(*ns,
> -			getnextvariablename.variable_name_size))
> -			return -EFAULT;
> +		if (put_user(*ns, getnextvariablename.variable_name_size)) {
> +			rv = -EFAULT;
> +			goto out;
> +		}
>  	}
>  
>  	if (vd) {
> -		if (copy_to_user(getnextvariablename.vendor_guid,
> -				 vd, sizeof(efi_guid_t)))
> -			return -EFAULT;
> +		if (copy_to_user(getnextvariablename.vendor_guid, vd,
> +							sizeof(efi_guid_t)))
> +			rv = -EFAULT;
>  	}
>  
> -	if (status != EFI_SUCCESS)
> -		return -EINVAL;
> -	return 0;
> +out:
> +	kfree(name);
> +	return rv;
>  }
>  
>  static long efi_runtime_get_nexthighmonocount(unsigned long arg)
> 
Acked-by: Colin Ian King <colin.king at canonical.com>