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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0FEF5C77B7E for ; Thu, 1 Jun 2023 13:20:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230268AbjFANUl (ORCPT ); Thu, 1 Jun 2023 09:20:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58402 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233300AbjFANUk (ORCPT ); Thu, 1 Jun 2023 09:20:40 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91A9C189 for ; Thu, 1 Jun 2023 06:20:37 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id EDE1764432 for ; Thu, 1 Jun 2023 13:20:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE36AC433D2; Thu, 1 Jun 2023 13:20:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1685625636; bh=2ivYBxUrMu5ya+HhXrzj768w3Nbdhpc6riw/0/sCCig=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=uaJanA2vaSI2c8u3brixoSmmVMQz/GywFF8NW4OOQHMu8JOkzucgxeIiqP9QBk3nc AF+2apUUSixpkl1Mr+W9fvA9nfYL2YsP/q6Q0rcRnsmngGZoCygtTiKkNQjaCAk8S6 OOrfWSnUtCZH83uBW5gI9xgRnbWJEQ5pzQGY+Vf0= Date: Thu, 1 Jun 2023 14:20:32 +0100 From: Greg KH To: Luiz Capitulino Cc: paul@paul-moore.com, sashal@kernel.org, stable@vger.kernel.org Subject: Re: Possible build time regression affecting stable kernels Message-ID: <2023060148-levers-freight-5b11@gregkh> References: <8892cb92-0f30-db36-e9db-4bec5e7eb46e@amazon.com> <2023060156-precision-prorate-ce46@gregkh> <20259cf7-d50d-4eca-482b-3a89cc94df7b@amazon.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20259cf7-d50d-4eca-482b-3a89cc94df7b@amazon.com> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Thu, Jun 01, 2023 at 09:13:21AM -0400, Luiz Capitulino wrote: > > > On 2023-06-01 02:06, Greg KH wrote: > > > > > > > > > On Wed, May 31, 2023 at 10:12:40PM -0400, Luiz Capitulino wrote: > > > Hi Paul, > > > > > > A number of stable kernels recently backported this upstream commit: > > > > > > """ > > > commit 4ce1f694eb5d8ca607fed8542d32a33b4f1217a5 > > > Author: Paul Moore > > > Date: Wed Apr 12 13:29:11 2023 -0400 > > > > > > selinux: ensure av_permissions.h is built when needed > > > """ > > > > > > We're seeing a build issue with this commit where the "crash" tool will fail > > > to start, it complains that the vmlinux image and /proc/version don't match. > > > > > > A minimum reproducer would be having "make" version before 4.3 and building > > > the kernel with: > > > > > > $ make bzImages > > > $ make modules > > > > > > Then compare the version strings in the bzImage and vmlinux images, > > > we can use "strings" for this. For example, in the 5.10.181 kernel I get: > > > > > > $ strings vmlinux | egrep '^Linux version' > > > Linux version 5.10.181 (ec2-user@ip-172-31-79-134.ec2.internal) (gcc (GCC) 7.3.1 20180712 (Red Hat 7.3.1-15), GNU ld version 2.29.1-31.amzn2) #2 SMP Thu Jun 1 01:26:38 UTC 2023 > > > > > > $ strings ./arch/x86_64/boot/bzImage | egrep 'ld version' > > > 5.10.181 (ec2-user@ip-172-31-79-134.ec2.internal) (gcc (GCC) 7.3.1 20180712 (Red Hat 7.3.1-15), GNU ld version 2.29.1-31.amzn2) #1 SMP Thu Jun 1 01:23:59 UTC 2023 > > > > > > The version string in the bzImage doesn't have the "Linux version" part, but > > > I think this is added by the kernel when printing. If you compare the strings, > > > you'll see that they have a different build date and the "#1" and "#2" are > > > different. > > > > > > This only happens with commit 4ce1f694eb5 applied and older "make", in my case I > > > have "make" version 3.82. > > > > > > If I revert 4ce1f694eb5 or use "make" version 4.3 I get identical strings (except > > > for the "Linux version" part): > > > > > > $ strings vmlinux | egrep '^Linux version' > > > Linux version 5.10.181+ (ec2-user@ip-172-31-79-134.ec2.internal) (gcc (GCC) 7.3.1 20180712 (Red Hat 7.3.1-15), GNU ld version 2.29.1-31.amzn2) #1 SMP Thu Jun 1 01:29:11 UTC 2023 > > > > > > $ strings ./arch/x86_64/boot/bzImage | egrep 'ld version' > > > 5.10.181+ (ec2-user@ip-172-31-79-134.ec2.internal) (gcc (GCC) 7.3.1 20180712 (Red Hat 7.3.1-15), GNU ld version 2.29.1-31.amzn2) #1 SMP Thu Jun 1 01:29:11 UTC 2023 > > > > > > Maybe the grouped target usage in 4ce1f694eb5 with older "make" is causing a > > > rebuild of the vmlinux image in "make modules"? If yes, is this expected? > > > > > > I'm afraid this issue could be high impact for distros with older user-space. > > > > Is this issue also in 6.4-rc1 where this change came from? > > Yes. I'm reporting this here because I'm more concerned with -stable kernels since > they're more likely to be running on older user-space. Yeah, we are bug-compatible! :) When this gets fixed in Linus's tree, I'll be glad to backport the changes to the other kernels. Please work with the developers to get that fixed there. thanks, greg k-h