From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D32F4C4727E for ; Wed, 23 Sep 2020 08:42:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9BFEF221F0 for ; Wed, 23 Sep 2020 08:42:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726537AbgIWImf (ORCPT ); Wed, 23 Sep 2020 04:42:35 -0400 Received: from jabberwock.ucw.cz ([46.255.230.98]:45778 "EHLO jabberwock.ucw.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726381AbgIWImf (ORCPT ); Wed, 23 Sep 2020 04:42:35 -0400 Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id 59AD61C0BB1; Wed, 23 Sep 2020 10:42:33 +0200 (CEST) Date: Wed, 23 Sep 2020 10:42:32 +0200 From: Pavel Machek To: madvenka@linux.microsoft.com Cc: kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, oleg@redhat.com, x86@kernel.org, luto@kernel.org, David.Laight@ACULAB.COM, fweimer@redhat.com, mark.rutland@arm.com, mic@digikod.net Subject: Re: [PATCH v2 0/4] [RFC] Implement Trampoline File Descriptor Message-ID: <20200923084232.GB30279@amd> References: <210d7cd762d5307c2aa1676705b392bd445f1baa> <20200922215326.4603-1-madvenka@linux.microsoft.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="zx4FCpZtqtKETZ7O" Content-Disposition: inline In-Reply-To: <20200922215326.4603-1-madvenka@linux.microsoft.com> User-Agent: Mutt/1.5.23 (2014-03-12) Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org --zx4FCpZtqtKETZ7O Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > Solution proposed in this RFC > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D >=20 > >From this RFC's perspective, there are two scenarios for dynamic code: >=20 > Scenario 1 > ---------- >=20 > We know what code we need only at runtime. For instance, JIT code generat= ed > for frequently executed Java methods. Only at runtime do we know what > methods need to be JIT compiled. Such code cannot be statically defined. = It > has to be generated at runtime. >=20 > Scenario 2 > ---------- >=20 > We know what code we need in advance. User trampolines are a good example= of > this. It is possible to define such code statically with some help from t= he > kernel. >=20 > This RFC addresses (2). (1) needs a general purpose trusted code generator > and is out of scope for this RFC. This is slightly less crazy talk than introduction talking about holes in W^X. But it is very, very far from normal Unix system, where you have selection of interpretters to run your malware on (sh, python, awk, emacs, ...) and often you can even compile malware from sources.=20 And as you noted, we don't have "a general purpose trusted code generator" for our systems. I believe you should simply delete confusing "introduction" and provide details of super-secure system where your patches would be useful, instead. Best regards, Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --zx4FCpZtqtKETZ7O Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAl9rCngACgkQMOfwapXb+vKeqgCgpVQMutlRE7F/wzcDjcBTlXwI RbAAnjRDzunOtf0iSPKO6rIM9FPy6+JQ =wVZX -----END PGP SIGNATURE----- --zx4FCpZtqtKETZ7O--