[PATCH] efi_loader: leave attribute check to StMM variable service

[Ilias Apalodimas]

Hi Kojima-san

This looks correct when U-Boot is using StMM for the variable storage.
Since Arm claims that SCT document is outdated should we also fix the
default behavior?  IOW U-Boot should return identical values when variables
are stored in a file in the ESP.

On Thu, Jan 26, 2023 at 12:15:12PM +0900, Masahisa Kojima wrote:
> Current U-Boot supports two EFI variable service, U-Boot own
> implementation and op-tee based StMM variable service.
> For latter case, parameter check should leave to StMM.
> This commit removes the attribute check from the common
> function(efi_query_variable_info) and moves it to
> lib/efi_loader/efi_variable.c.
>
> Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
> ---
>  lib/efi_loader/efi_var_common.c | 10 +---------
>  lib/efi_loader/efi_variable.c   | 10 ++++++++++
>  2 files changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/lib/efi_loader/efi_var_common.c b/lib/efi_loader/efi_var_common.c
> index eb83702781..ad50bffd2b 100644
> --- a/lib/efi_loader/efi_var_common.c
> +++ b/lib/efi_loader/efi_var_common.c
> @@ -165,17 +165,9 @@ efi_status_t EFIAPI efi_query_variable_info(
>
>  	if (!maximum_variable_storage_size ||
>  	    !remaining_variable_storage_size ||
> -	    !maximum_variable_size ||
> -	    !(attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS))
> +	    !maximum_variable_size)
>  		return EFI_EXIT(EFI_INVALID_PARAMETER);
>
> -	if ((attributes & ~(u32)EFI_VARIABLE_MASK) ||
> -	    (attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) ||
> -	    (attributes & EFI_VARIABLE_HARDWARE_ERROR_RECORD) ||
> -	    (!IS_ENABLED(CONFIG_EFI_SECURE_BOOT) &&
> -	     (attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS)))
> -		return EFI_EXIT(EFI_UNSUPPORTED);
> -
>  	ret = efi_query_variable_info_int(attributes,
>  					  maximum_variable_storage_size,
>  					  remaining_variable_storage_size,
> diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
> index 7c32adf6e5..86f39181e0 100644
> --- a/lib/efi_loader/efi_variable.c
> +++ b/lib/efi_loader/efi_variable.c
> @@ -349,6 +349,16 @@ efi_status_t efi_query_variable_info_int(u32 attributes,
>  					 u64 *remaining_variable_storage_size,
>  					 u64 *maximum_variable_size)
>  {
> +	if (!(attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS))
> +		return EFI_EXIT(EFI_INVALID_PARAMETER);
> +
> +	if ((attributes & ~(u32)EFI_VARIABLE_MASK) ||
> +	    (attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) ||
> +	    (attributes & EFI_VARIABLE_HARDWARE_ERROR_RECORD) ||
> +	    (!IS_ENABLED(CONFIG_EFI_SECURE_BOOT) &&
> +	     (attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS)))
> +		return EFI_EXIT(EFI_UNSUPPORTED);
> +
>  	*maximum_variable_storage_size = EFI_VAR_BUF_SIZE -
>  					 sizeof(struct efi_var_file);
>  	*remaining_variable_storage_size = efi_var_mem_free();
> --
> 2.17.1
>

Cheers
/Ilias