Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755952Ab1FASac (ORCPT ); Wed, 1 Jun 2011 14:30:32 -0400 Received: from lennier.cc.vt.edu ([198.82.162.213]:50302 "EHLO lennier.cc.vt.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751042Ab1FASab (ORCPT ); Wed, 1 Jun 2011 14:30:31 -0400 X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.3-dev To: Andrew Lutomirski Cc: Ingo Molnar , x86@kernel.org, Thomas Gleixner , linux-kernel@vger.kernel.org, Jesper Juhl , Borislav Petkov , Linus Torvalds , Andrew Morton , Arjan van de Ven , Jan Beulich , richard -rw- weinberger , Mikael Pettersson , Andi Kleen Subject: Re: [PATCH v3 10/10] x86-64: Add CONFIG_UNSAFE_VSYSCALLS to feature-removal-schedule In-Reply-To: Your message of "Wed, 01 Jun 2011 13:41:56 EDT." From: Valdis.Kletnieks@vt.edu References: <7e604b2dd699a30204fda3d1011f3af5a2c56572.1306847455.git.luto@mit.edu> <10442.1306949732@turing-police.cc.vt.edu> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1306952865_2661P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Wed, 01 Jun 2011 14:27:45 -0400 Message-ID: <13093.1306952865@turing-police.cc.vt.edu> X-Mirapoint-Received-SPF: 198.82.161.152 auth3.smtp.vt.edu Valdis.Kletnieks@vt.edu 2 pass X-Mirapoint-IP-Reputation: reputation=neutral-1, source=Fixed, refid=n/a, actions=MAILHURDLE SPF TAG X-Junkmail-Status: score=10/50, host=steiner.cc.vt.edu X-Junkmail-Signature-Raw: score=unknown, refid=str=0001.0A020207.4DE684A4.0178,ss=1,fgs=0, ip=0.0.0.0, so=2010-07-22 22:03:31, dmn=2009-09-10 00:05:08, mode=single engine X-Junkmail-IWF: false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1565 Lines: 46 --==_Exmh_1306952865_2661P Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable On Wed, 01 Jun 2011 13:41:56 EDT, Andrew Lutomirski said: >> + =A0 =A0 =A0 =A0 On a system with recent enough glibc (probably 2.14 = or >> + =A0 =A0 =A0 =A0 newer) and no static binaries, you can say N withou= t a >> + =A0 =A0 =A0 =A0 performance penalty to improve security >> >> So I checked my laptop (Fedora 16 Rawhide), and found a bunch of stati= c binaries. The ones >> that look like people may care: > The binaries will still work -- they'll just take a small performance > hit (=7E220ns on Sandy Bridge) every time they call time(). Ah. I misparsed the Kconfig help - I read it as =22If you have no static = binaries, setting this to N doesn't introduce a performance hit=22 (with an implied= =22if you have static binaries, this will hose you=22). Adding =22Static binaries = will continue to work at a very small performance penalty=22 would probably help. --==_Exmh_1306952865_2661P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Exmh version 2.5 07/13/2001 iD8DBQFN5oShcC3lWbTT17ARAukDAKDAnFF5saZAHWCj18NYMaWQIKJENgCg+x2r GLS1PNJRRid/M4Mg16YHa78= =zbmb -----END PGP SIGNATURE----- --==_Exmh_1306952865_2661P-- -- 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/