From owner-freebsd-arch@FreeBSD.ORG Thu Jul 31 05:02:04 2014 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 38749F32; Thu, 31 Jul 2014 05:02:04 +0000 (UTC) Received: from vps1.elischer.org (vps1.elischer.org [204.109.63.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "vps1.elischer.org", Issuer "CA Cert Signing Authority" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id DECDD2557; Thu, 31 Jul 2014 05:02:03 +0000 (UTC) Received: from Julian-MBP3.local (ppp121-45-250-191.lns20.per2.internode.on.net [121.45.250.191]) (authenticated bits=0) by vps1.elischer.org (8.14.9/8.14.9) with ESMTP id s6V51vc5024599 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Wed, 30 Jul 2014 22:01:59 -0700 (PDT) (envelope-from julian@freebsd.org) Message-ID: <53D9CDBF.6030003@freebsd.org> Date: Thu, 31 Jul 2014 13:01:51 +0800 From: Julian Elischer User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Pedro Giffuni , Shawn Webb Subject: Re: [RFC] ASLR Whitepaper and Candidate Final Patch References: <96C72773-3239-427E-A90B-D05FF0F5B782@freebsd.org> <20140720201858.GB29618@pwnie.vrt.sourcefire.com> <20140723004543.GH29618@pwnie.vrt.sourcefire.com> <20140724175704.GT29618@pwnie.vrt.sourcefire.com> <112E989D-607B-47AC-8942-0FB049DA6C3D@freebsd.org> In-Reply-To: <112E989D-607B-47AC-8942-0FB049DA6C3D@freebsd.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit Cc: PaX Team , freebsd-arch@freebsd.org, Bryan Drewery , Robert Watson , Oliver Pinter X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 31 Jul 2014 05:02:04 -0000 On 7/31/14, 11:00 AM, Pedro Giffuni wrote: > Il giorno 24/lug/2014, alle ore 12:57, Shawn Webb ha scritto: > >> >> The unixbench results are in. The overall scores are below. >> >> ASLR Disabled: 456.33 >> ASLR Enabled: 357.05 >> No ASLR: 474.03 is bigger better or worse? >> >> I've uploaded the raw results to >> http://0xfeedface.org/~shawn/aslr/2014-07-24_benchmark.tar.gz >> >> Take these results with a grain of salt, given that some of unixbench's >> test are filesystem-related and I'm running ZFS on an old laptop with >> little RAM. It does show that there is a performance impact when ASLR is >> enabled. and even from being included. I don't believe that should be forgotten. 1% here ,2% there.. soon you have lost noticeable performance. > The effect of the available RAM and/or age of the system is > independent of ASLR being on or off si I think the results are valid. > > As Robert said, the particularly bad result is the effect of having ASLR > disabled vs not having the patch at all. The priority should certainly be > to fix this. > > The effect of ASLR seems significant, I did expect it less but it is something > that can be expected. People that enable ASLR have to be aware that there > are consequences performance-wise. A further effect that hasn’t been quantified > but could be obtained from the raw data is the standard deviation. I would expect > that the randomization induced from using ASLR will cause an important increase > in the standard deviation and that performance will be basically unpredictable. > > The last issue is a show stopper from enabling ASLR by default but the first > issue is a show stopper from committing the patch at all :(. > > Of course, all just IMHO. > > Pedro. > > _______________________________________________ > freebsd-arch@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-arch > To unsubscribe, send any mail to "freebsd-arch-unsubscribe@freebsd.org" > > >