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 52880C433F5 for ; Wed, 8 Dec 2021 13:06:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234077AbhLHNJz (ORCPT ); Wed, 8 Dec 2021 08:09:55 -0500 Received: from sin.source.kernel.org ([145.40.73.55]:53372 "EHLO sin.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234066AbhLHNJy (ORCPT ); Wed, 8 Dec 2021 08:09:54 -0500 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 sin.source.kernel.org (Postfix) with ESMTPS id 9176ACE2180 for ; Wed, 8 Dec 2021 13:06:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3F52DC00446; Wed, 8 Dec 2021 13:06:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1638968779; bh=jBjNCeVJHLsxhV+tXkdj+uvYJOsHT+jIBqBjO7s6QGQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=uMOmxQYbSMwMUVb/FQsmeM9GpPswZnL6FM5C+OK2wNmvy7Zwruy1COEidijMYGVs3 KyMSzI7SzIR64YOMXNpzePo+SA76sBNjxPPAw/Lsil+TgblTMXZH/WDi+G9oPqNmy7 qyb5b/MUatwxjypJzEy4TZYbfi/znz2nYUEhEQ/E= Date: Wed, 8 Dec 2021 14:06:14 +0100 From: Greg KH To: Kees Cook Cc: Thomas Lindroth , stable@vger.kernel.org Subject: Re: Could the fix for broken gcc-plugins with gcc-11 be backported to 5.10? Message-ID: References: <202112061220.79D1A6823E@keescook> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <202112061220.79D1A6823E@keescook> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Mon, Dec 06, 2021 at 12:29:31PM -0800, Kees Cook wrote: > On Mon, Dec 06, 2021 at 03:41:55PM +0100, Greg KH wrote: > > On Mon, Dec 06, 2021 at 02:59:57PM +0100, Thomas Lindroth wrote: > > > On 12/6/21 14:27, Greg KH wrote: > > > > On Mon, Dec 06, 2021 at 02:24:29PM +0100, Thomas Lindroth wrote: > > > > > On 12/6/21 14:04, Greg KH wrote: > > > > > > On Mon, Dec 06, 2021 at 01:59:31PM +0100, Thomas Lindroth wrote: > > > > > > > Build support for gcc-plugins are not detected with gcc-11 in lts kernels. > > > > > > > Gentoo and Arch apply their own patch to fix the problem in their distribution > > > > > > > kernels but I would prefer if a proper fix was applied upstream. > > > > > > > > > > > > > > https://bugs.gentoo.org/814200 a gentoo report with the relevant info. > > > > > > > > > > > > > > I've searched for any upstream discussions about the problem but I've only found > > > > > > > one message saying the backport needs an additional fix. That was almost a year > > > > > > > ago. https://www.spinics.net/lists/stable/msg438000.html > > > > > > > > > > > > We can not take a patch in a stable kernel release unless it is already > > > > > > in Linus's tree. Please work to get a patch accepted there first, > > > > > > before worrying about older kernel versions. > > > > > > > > > > > > thanks, > > > > > > > > > > > > greg k-h > > > > > > > > > > > > > > > > The problem was fixed in Linus tree in commit 67a5a68013056cbcf0a647e36cb6f4622fb6a470 > > > > > "gcc-plugins: fix gcc 11 indigestion with plugins..." added in v5.11 > > > > > > > > > > That's the patch that needed some kind of additional fix before it could be backported > > > > > but that fix never materialized. > > > > > > > > If you have a working version, based on a distro's use, please provide > > > > it and I will be glad to pick it up. > > > > > > > > thanks, > > > > > > > > greg k-h > > > > > > > > > > https://dev.gentoo.org/~mpagano/genpatches/trunk/5.10/2910_fix-gcc-detection-method.patch > > > > > > Here is the patch gentoo applies to 5.10. It seems to be a combination of two upstream > > > commits: > > > 67a5a68013056cbcf0a647e36cb6f4622fb6a470 "gcc-plugins: fix gcc 11 indigestion with plugins..." > > > 1e860048c53ee77ee9870dcce94847a28544b753 "gcc-plugins: simplify GCC plugin-dev capability test" > > > > That's not how I can take a patch, sorry. Please submit these as > > individual emails so that then could be applied. > > > > > I can't vouch for the correctness of that fix. I'm just a regular user who stumbled upon this > > > problem and found that gentoo bug report. Check with Kees Cook for that "additional fix". I > > > don't know what fix that is. > > > > I don't think either of them differ from what is in mainline, so I do > > not know. > > Hi! > > Yeah, the two fixes that I think are needed for v5.10 are: > > 1e860048c53ee77ee9870dcce94847a28544b753 > 67a5a68013056cbcf0a647e36cb6f4622fb6a470 > > This additionally appears to match the combo patch in gentoo: > https://814200.bugs.gentoo.org/attachment.cgi?id=746715 > > Local build testing shows the plugins working... Ok, both now queued up, thanks. greg k-h