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=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 9C08AC433E0 for ; Tue, 16 Feb 2021 15:56:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5DC7964DA5 for ; Tue, 16 Feb 2021 15:56:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230365AbhBPPzx (ORCPT ); Tue, 16 Feb 2021 10:55:53 -0500 Received: from mail.kernel.org ([198.145.29.99]:47570 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230337AbhBPPzl (ORCPT ); Tue, 16 Feb 2021 10:55:41 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3BDE664D9E; Tue, 16 Feb 2021 15:55:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1613490900; bh=KFPdQpy+hKbJ+DnvTlX9CTGk1+OUNb7Jti63BkjZxM8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=gAfSCgtHlR8D3ean5JJ45Nigwu12GAt7lEG4FZivurakw/RU6XWlZIfuAm7GfVRTi Z+kq981/hzh6jgx9BfYAKJ2YYrAirwygBVfu0odxzPhyDwRCRCCPwF4nxHL1b4Ult8 nVIReDkMtnHUO0uXj/pzkuSae1cxiOJqvrRplun8= Date: Tue, 16 Feb 2021 16:54:58 +0100 From: Greg Kroah-Hartman To: Josh Poimboeuf Cc: Steven Rostedt , LKML , Ingo Molnar , Andrew Morton Subject: Re: [PATCH] ftrace: Do not reference symbols in sections without size Message-ID: References: <20210215164446.530f6311@gandalf.local.home> <20210216000504.axm3k4xho47c6drz@treble> <20210215200639.67141685@oasis.local.home> <20210215210057.4ceb6339@oasis.local.home> <20210216095121.4fe321dc@gandalf.local.home> <20210216154539.qac763oef4czrtss@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210216154539.qac763oef4czrtss@treble> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 16, 2021 at 09:45:39AM -0600, Josh Poimboeuf wrote: > On Tue, Feb 16, 2021 at 09:51:21AM -0500, Steven Rostedt wrote: > > On Tue, 16 Feb 2021 12:04:06 +0100 > > Greg Kroah-Hartman wrote: > > > > > Thanks for this. > > > > > > Should I also queue these up for 4.9 and 4.14 which do not have these > > > commits in them either (but somehow do not show the problem, yet)? > > > > This bothers me. I want to know exactly why this is a problem. > > I actually see the same problem with 4.9 and 4.14, using the same > config. Ok, that's good to know. > It's very config-specific. Something has to convince the toolchain to > not reference those two weak functions by section. I've queued up all 3 patches (Steven collapsed 2 into 1 it seems) for 4.4.y, 4.9.y, and 4.14.y now. > > That said, it is fine to backport those patches, and I would include 4.9 > > and 4.14, as I would think you have a similar requirement that we have in > > the stable-rt trees. That is you shouldn't experience a regression going > > from an older kernel to a newer one because the older one had a fix > > backported to it that a newer one did not. Basically the same rationale that > > all fixes go into Linus's tree before backporting. We do the same on the > > stable-rt, where all fixes go in all maintained stable trees that are newer > > than the one you are backporting to. > > > > Although, it does allow more to be traced than what recordmcount enables. > > But hopefully it doesn't cause any issues. Maybe I should do some ftrace > > testing before you go and release any of those stables with those patches. > > > > I'm looking to see if this new "feature" of binutils isn't causing trouble > > elsewhere. I'm thinking that ftrace is just the canary here. > > It already caused quite a bit of trouble with objtool (as did a previous > similar change by the Clang assembler). I feel like we go through this every major binutils release. Why isn't "build the Linux kernel" part of the binutils regression test suite by now? :) thanks, greg k-h