Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932454AbcLIHz7 (ORCPT ); Fri, 9 Dec 2016 02:55:59 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48026 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932146AbcLIHz5 (ORCPT ); Fri, 9 Dec 2016 02:55:57 -0500 Subject: Re: [PATCH] x86/kbuild: enable modversions for symbols exported from asm To: Nicholas Piggin , Don Zickus References: <20161129135118.24696-1-kilobyte@angband.pl> <30bb2db4-47bd-0c35-8328-ef032b551f06@suse.com> <20161129195721.GI2697@decadent.org.uk> <20161201051852.28dc335f@roar.ozlabs.ibm.com> <20161201041325.GX35881@redhat.com> <20161201153215.43b6cec7@roar.ozlabs.ibm.com> <20161201152039.GB35881@redhat.com> <20161209135041.5ff12770@roar.ozlabs.ibm.com> Cc: Linus Torvalds , Ben Hutchings , Michal Marek , Adam Borowski , Greg Kroah-Hartman , Linux Kbuild mailing list , Debian kernel maintainers , "linux-arch@vger.kernel.org" , Arnd Bergmann , Ingo Molnar , Linux Kernel Mailing List From: Stanislav Kozina Message-ID: <0937c184-1946-c494-56b6-c38fd0b632c2@redhat.com> Date: Fri, 9 Dec 2016 08:55:51 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <20161209135041.5ff12770@roar.ozlabs.ibm.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Fri, 09 Dec 2016 07:55:56 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 686 Lines: 15 >> The question is how to provide a similar guarantee if a different way? > As a tool to aid distro reviewers, modversions has some value, but the > debug info parsing tools that have been mentioned in this thread seem > superior (not that I've tested them). On the other hand the big advantage of modversions is that it also verifies the checksum during runtime (module loading). In other words, I believe that any other solution should still generate some form of checksum/watermark which can be easily checked for compatibility on module load. It should not be hard to add to the DWARF based tools though. We'd just parse DWARF data instead of the C code. Regards, -Stanislav