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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 4062CC5DF61 for ; Thu, 7 Nov 2019 15:25:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 17589218AE for ; Thu, 7 Nov 2019 15:25:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730221AbfKGPY7 (ORCPT ); Thu, 7 Nov 2019 10:24:59 -0500 Received: from mx2.suse.de ([195.135.220.15]:35940 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729829AbfKGPY7 (ORCPT ); Thu, 7 Nov 2019 10:24:59 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id B5B45B26E; Thu, 7 Nov 2019 15:24:57 +0000 (UTC) Date: Thu, 7 Nov 2019 16:24:57 +0100 (CET) From: Miroslav Benes To: Joe Lawrence cc: live-patching@vger.kernel.org, linux-kselftest@vger.kernel.org, shuah@kernel.org Subject: Re: [PATCH] selftests/livepatch: filter 'taints' from dmesg comparison In-Reply-To: Message-ID: References: <20191106222801.7541-1-joe.lawrence@redhat.com> User-Agent: Alpine 2.21 (LSU 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org On Thu, 7 Nov 2019, Joe Lawrence wrote: > On 11/7/19 9:53 AM, Miroslav Benes wrote: > > On Thu, 7 Nov 2019, Joe Lawrence wrote: > > > >> On 11/7/19 3:42 AM, Miroslav Benes wrote: > >>> On Wed, 6 Nov 2019, Joe Lawrence wrote: > >>> > >>>> The livepatch selftests compare expected dmesg output to verify kernel > >>>> behavior. They currently filter out "tainting kernel with > >>>> TAINT_LIVEPATCH" messages which may be logged when loading livepatch > >>>> modules. > >>>> > >>>> Further filter the log to also drop "loading out-of-tree module taints > >>>> kernel" messages in case the klp_test modules have been build without > >>>> the in-tree module flag. > >>> > >>> That is true, but "tainting kernel with TAINT_LIVEPATCH" should be printed > >>> out even in this case. check_modinfo_livepatch() is called for all modules > >>> and relies on MODINFO(livepatch, Y). > >>> > So either the bug is elsewhere or I need one more cup of tea. > > > > Ok, the above is not relevant here. > > > > I'm only wondering about the execution steps, because supporting modules > > lib/livepatch/ should be built as in-tree. No? > > > > Ah, I see. Well as you noted they are modprobed, so theoretically they could > come from anywhere OOT, right? Yes. > In my test, I had a kernel tree, but only wanted to build the test modules. > Once I did a 'make modules SUBDIR=' or 'make M= ...' KBUILD_EXTMOD got flipped > on and the modules lost in-tree status. No amount of googling could tell me > how to build a single in-tree directory of modules :( "make lib/livepatch/test_klp_livepatch.ko" should do the trick. "make lib/livepatch/" only builds the object files and I haven't found a way to make it link .ko modules other than specifying them one by one directly. > And then it seemed that > opening the tests for OOT modules was reasonable anyway. That's an interesting idea. If a module is in tree, it is under our control. So we know what "testing capabilities" it offers. I guess that with OOT testing modules the selftests would have to be smarter. Miroslav