From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6528A1DFDE for ; Sat, 20 Apr 2024 18:19:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713637184; cv=none; b=ht8K4lPfueUizjixiRrnX3qIjh4Ac1L8q2N+1grabXaBVvhACAjECgoFmxyiM4VnsrYi8LmqBJMD1sdQxPZBaiWtg9xaCdRJIcynZk9fa3hyjXUZMTszYuOcmWT1ZjkqJf0hc3or7VNg7Y/IjYaKmjZH7I6MehN1i4TnuxSPQdQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713637184; c=relaxed/simple; bh=BMdXnEOYanaJkv2dxl2IwISChgysH2clKbvNEy1v2qg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=meDxxxf+1uoYmum8DV64MQcgjbZGuplrksQg00FaZbIfAWPDO9bp0S3bivmqW2ftExFoXCLze1wR6W/rshz+1J+4a9Dhz6bwP2VF4t7ZKFHYa+9mTJq1uYpdOUahdhPn1CbXoE2QKsz5GqvXIKuYHSwTjJ0H5Fqy7Q8PX+TVTk8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CZEiAfcU; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="CZEiAfcU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B320EC072AA; Sat, 20 Apr 2024 18:19:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713637183; bh=BMdXnEOYanaJkv2dxl2IwISChgysH2clKbvNEy1v2qg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=CZEiAfcUC/Qss7ofvzfw/TDwHHGSUGkwTkxQdsflFyD0a3/E2hxsNHQs56XKZduyH j+LispvCW+0+/6ZNqXSQaED4is/QWjUyn95GtGiiNum4dkqSrAwg8vHH+RI/40Uj97 Qk39OsvTbIIgLOFqOH1JZumJH/vYcCI0YUfsleUyWxIZhnOCZ0TIHS0NY4l92iDu/w 74nFZZUCxpVu0qNzLI1qOs3wsSsOUc+slB52dY5XaGKJTb4QqnkD1yUsjuXQ6lkK/h 9BXuRm9Db1BTdMY3bdtBqEy6OBgRYw5vRJiqIWe1M/yxIK+ZrNEXhhsIgJtXeTnRTw aeMz+0ays89ng== Date: Sat, 20 Apr 2024 11:19:42 -0700 From: Eric Biggers To: linux-crypto@vger.kernel.org Cc: x86@kernel.org Subject: Re: [PATCH] crypto: x86/aes-gcm - simplify GCM hash subkey derivation Message-ID: <20240420181942.GA786@quark.localdomain> References: <20240420060037.26014-1-ebiggers@kernel.org> Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240420060037.26014-1-ebiggers@kernel.org> On Fri, Apr 19, 2024 at 11:00:37PM -0700, Eric Biggers wrote: > + aes_encrypt(aes_key, hash_subkey, page_address(ZERO_PAGE(0))); Actually, page_address(ZERO_PAGE(0)) expands into a surprisingly large number of instructions. Using empty_zero_page directly would avoid this, but there's little precedent for doing that. For now, I think just using something like 'static const u8 zeroes[16]' is the way to go for small buffers like this. - Eric