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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 CE889C48BD6 for ; Thu, 27 Jun 2019 09:39:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AD5A82080C for ; Thu, 27 Jun 2019 09:39:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726543AbfF0JjI (ORCPT ); Thu, 27 Jun 2019 05:39:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53881 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725385AbfF0JjI (ORCPT ); Thu, 27 Jun 2019 05:39:08 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 889F081E0A; Thu, 27 Jun 2019 09:38:59 +0000 (UTC) Received: from oldenburg2.str.redhat.com (dhcp-192-180.str.redhat.com [10.33.192.180]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 507835C1B4; Thu, 27 Jun 2019 09:38:46 +0000 (UTC) From: Florian Weimer To: Andy Lutomirski Cc: Dave Martin , Yu-cheng Yu , X86 ML , "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , LKML , "open list\:DOCUMENTATION" , Linux-MM , linux-arch , Linux API , Arnd Bergmann , Balbir Singh , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue , Szabolcs Nagy , libc-alpha Subject: Re: [PATCH] binfmt_elf: Extract .note.gnu.property from an ELF file References: <20190501211217.5039-1-yu-cheng.yu@intel.com> <20190502111003.GO3567@e103592.cambridge.arm.com> Date: Thu, 27 Jun 2019 11:38:45 +0200 In-Reply-To: (Andy Lutomirski's message of "Wed, 26 Jun 2019 10:14:07 -0700") Message-ID: <87ef3fweoq.fsf@oldenburg2.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Thu, 27 Jun 2019 09:39:08 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Andy Lutomirski: > Also, I don't think there's any actual requirement that the upstream > kernel recognize existing CET-enabled RHEL 8 binaries as being > CET-enabled. I tend to think that RHEL 8 jumped the gun here. The ABI was supposed to be finalized and everyone involved thought it had been reviewed by the GNU gABI community and other interested parties. It had been included in binutils for several releases. >From my point of view, the kernel is just a consumer of the ABI. The kernel would not change an instruction encoding if it doesn't like it for some reason, either. > While the upstream kernel should make some reasonble effort to make > sure that RHEL 8 binaries will continue to run, I don't see why we > need to go out of our way to keep the full set of mitigations > available for binaries that were developed against a non-upstream > kernel. They were developed against the ABI specification. I do not have a strong opinion what the kernel should do going forward. I just want to make clear what happened. Thanks, Florian