Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932552AbaGQMkD (ORCPT ); Thu, 17 Jul 2014 08:40:03 -0400 Received: from mx1.redhat.com ([209.132.183.28]:30396 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754920AbaGQMkA (ORCPT ); Thu, 17 Jul 2014 08:40:00 -0400 Message-ID: <53C7C40E.8070504@redhat.com> Date: Thu, 17 Jul 2014 14:39:42 +0200 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: "H. Peter Anvin" CC: Andy Lutomirski , kvm list , "Theodore Ts'o" , "linux-kernel@vger.kernel.org" , Kees Cook , X86 ML , Srivatsa Vaddagiri , Raghavendra K T , Gleb Natapov , Paolo Bonzini , Bandan Das , hannes@stressinduktion.org Subject: Re: [PATCH v3 2/5] random,x86: Add arch_get_slow_rng_u64 References: <5778e65d5ca52bebbaa023e177d863e44f098e96.1405546879.git.luto@amacapital.net> <53C6F5A9.80400@zytor.com> <53C703ED.2010605@zytor.com> In-Reply-To: <53C703ED.2010605@zytor.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/17/2014 12:59 AM, H. Peter Anvin wrote: > On 07/16/2014 03:40 PM, Andy Lutomirski wrote: >> On Wed, Jul 16, 2014 at 3:13 PM, Andy Lutomirski wrote: >>> My personal preference is to defer this until some user shows up. I >>> think that even this would be too complicated for KASLR, which is the >>> only extremely early-boot user that I found. >>> >>> Hmm. Does the prandom stuff want to use this? >> >> prandom isn't even using rdrand. I'd suggest fixing this separately, >> or even just waiting until someone goes and deletes prandom. > > prandom is exactly the opposite; it is designed for when we need > possibly low quality random numbers very quickly. RDRAND is actually > too slow. Yep, prandom() is quite heavily used in the network stack where it's traded for speed. -- 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/