Re: [PATCH v5 3/3] fscrypt: add support for hardware-wrapped keys

[Bart Van Assche <bvanassche@xxxxxxx>]

On 2/27/22 23:05, Eric Biggers wrote:
> diff --git a/include/uapi/linux/fscrypt.h b/include/uapi/linux/fscrypt.h
> index 9f4428be3e362..884c5bf526a05 100644
> --- a/include/uapi/linux/fscrypt.h
> +++ b/include/uapi/linux/fscrypt.h
> @@ -20,6 +20,7 @@
>   #define FSCRYPT_POLICY_FLAG_DIRECT_KEY		0x04
>   #define FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64	0x08
>   #define FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32	0x10
> +#define FSCRYPT_POLICY_FLAG_HW_WRAPPED_KEY	0x20
>   
>   /* Encryption algorithms */
>   #define FSCRYPT_MODE_AES_256_XTS		1
> @@ -115,7 +116,7 @@ struct fscrypt_key_specifier {
>    */
>   struct fscrypt_provisioning_key_payload {
>   	__u32 type;
> -	__u32 __reserved;
> +	__u32 flags;
>   	__u8 raw[];
>   };
>   
> @@ -124,7 +125,9 @@ struct fscrypt_add_key_arg {
>   	struct fscrypt_key_specifier key_spec;
>   	__u32 raw_size;
>   	__u32 key_id;
> -	__u32 __reserved[8];
> +#define FSCRYPT_ADD_KEY_FLAG_HW_WRAPPED			0x00000001
> +	__u32 flags;
> +	__u32 __reserved[7];
>   	__u8 raw[];
>   };

Is it allowed to use _Static_assert() in UAPI header files? There are already 
some static_assert() checks under include/linux to verify the size of certain 
data structures. gcc supports _Static_assert() since version 4.6. That is older 
than the minimum required gcc version to build the kernel.

Thanks,

Bart.