Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753600AbaLANkK (ORCPT ); Mon, 1 Dec 2014 08:40:10 -0500 Received: from mx1.redhat.com ([209.132.183.28]:52299 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752596AbaLANkI (ORCPT ); Mon, 1 Dec 2014 08:40:08 -0500 Message-ID: <547C6F88.9000206@redhat.com> Date: Mon, 01 Dec 2014 14:39:20 +0100 From: Daniel Borkmann User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Dan Carpenter CC: tytso@mit.edu, zatimend@hotmail.co.uk, linux-kernel@vger.kernel.org, Hannes Frederic Sowa , Alexey Dobriyan , Kees Cook , Julia Lawall Subject: Re: [PATCH] random: add and use memzero_explicit() for clearing data References: <1408996899-4892-1-git-send-email-dborkman@redhat.com> <20141201102529.GA9666@mwanda> <547C4B59.1000807@redhat.com> <20141201112957.GC5048@mwanda> <20141201113815.GD5048@mwanda> In-Reply-To: <20141201113815.GD5048@mwanda> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/01/2014 12:38 PM, Dan Carpenter wrote: > On Mon, Dec 01, 2014 at 02:29:57PM +0300, Dan Carpenter wrote: >> On Mon, Dec 01, 2014 at 12:04:57PM +0100, Daniel Borkmann wrote: >>> Well, BSD has helpers such as bzero_explicit() for such cases to work >>> around this, which memzero_explicit() similarly does; see also [1]. >>> >>> [1] https://gcc.gnu.org/ml/gcc-help/2014-10/msg00059.html >> >> We should make memset() a define and call a custom function internally. > > Or we could specify -fno-builtin-memset like the GCC people suggest. If there's a better, reliable way, I'm all for it. To me, memzero_explicit() seemed like the least intrusive variant doing the job, I'm unsure if globally setting -fno-builtin-memset will come with unforeseen side-effects on some archs (besides performance-wise). -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/