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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 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 65263C433DB for ; Tue, 16 Feb 2021 17:55:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2834D64E08 for ; Tue, 16 Feb 2021 17:55:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231217AbhBPRy7 (ORCPT ); Tue, 16 Feb 2021 12:54:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:38478 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231231AbhBPRyN (ORCPT ); Tue, 16 Feb 2021 12:54:13 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 66FBE64E04; Tue, 16 Feb 2021 17:53:31 +0000 (UTC) Date: Tue, 16 Feb 2021 12:53:29 -0500 From: Steven Rostedt To: Greg Kroah-Hartman Cc: Josh Poimboeuf , LKML , Ingo Molnar , Andrew Morton Subject: Re: [PATCH] ftrace: Do not reference symbols in sections without size Message-ID: <20210216125329.5dcc9e03@gandalf.local.home> In-Reply-To: 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> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 16 Feb 2021 16:54:58 +0100 Greg Kroah-Hartman wrote: > 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. > Interesting. I removed the "-mrecordmcount" option from 5.10.16, and I'm currently building it, and so far it has no issues. :-/ This is on a fresh install of archlinux using binutils 2.36-3. > 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. Which were the three patches. And if I collapsed it into 1, that was by mistake :-/ I was doing the work on the archlinux VM and was using quilt to fix up the backport (as I usually do), but I was using vim instead of my normal emacs (yes I'm one of those), and may have screwed things up. > > > > 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? :) Perhaps it builds the latest kernel fine? As I said, I'm currently testing a 5.10 build (couldn't get the 4.4 to boot, so I wanted to see if the issue is on 5.10 as that's the kernel they were using). -- Steve