Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755470AbdGTRwS (ORCPT ); Thu, 20 Jul 2017 13:52:18 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:48448 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754035AbdGTRwQ (ORCPT ); Thu, 20 Jul 2017 13:52:16 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org BCC8D6077C Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=sboyd@codeaurora.org Date: Thu, 20 Jul 2017 10:52:13 -0700 From: Stephen Boyd To: Masahiro Yamada Cc: Rob Clark , Michal Marek , Linux Kernel Mailing List , linux-arm-msm , "linux-arm-kernel@lists.infradead.org" , Linux Kbuild mailing list , Bjorn Andersson Subject: Re: [PATCH] kbuild: modpost: Warn about references from rodata to __init text Message-ID: <20170720175213.GB3291@codeaurora.org> References: <20170630225822.25349-1-sboyd@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2316 Lines: 51 On 07/20, Masahiro Yamada wrote: > Hi Stephen, Rob, > > 2017-07-01 8:59 GMT+09:00 Rob Clark : > > On Fri, Jun 30, 2017 at 6:58 PM, Stephen Boyd wrote: > >> If we have a structure that's marked const it will be placed > >> into the .rodata section but it could reference an init section > >> function. Include the read only data section in the check we have > >> for read/write data sections referencing init sections so we can > >> find this class of problems. This exposes quite a few places > >> where const marked structures are referencing __init functions and > >> __init data that we were previously ignoring. > >> > >> Cc: Rob Clark > >> Cc: Bjorn Andersson > >> Signed-off-by: Stephen Boyd > >> --- > >> > >> Making this change leads to quite a few other errors even on the > >> multi_v7_defconfig for ARM[1]. I still need to do a build of the > >> allmodconfig to see how many other errors there, but it seems to > >> be quite a few. I suppose those will need to be fixed before we can > >> merge this? > > > > thanks.. the explosions you get with these mistakes when building > > drivers as modules in a distro kernel config are quite "fun" to > > debug.. > > > > I'm not quite sure about the rules for whether merging this would > > count as a regression, but I would argue those drivers are already > > broken, just no one noticed yet. Similar to when a new gcc gets more > > clever about detecting bugs. So I wouldn't be against merging this > > first to force drivers to fix their crap ;-) > > I applied this, but this way seems unacceptable. > I cannot send a pull-req for this > unless most of the warnings are fixed. > > Is there any activity for driver fixes? Sorry, no. I've only had a little time to look at the errors reported. Some of them seem to be noise, because there are structures that have a handful of members where one of the members points to an __init function or piece of data that is only used in __init code. We would need to mark these structures as __ref or write more complicated section mismatch checking code to be silent in these cases. -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project