Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755020AbbDOPcO (ORCPT ); Wed, 15 Apr 2015 11:32:14 -0400 Received: from bh-25.webhostbox.net ([208.91.199.152]:56677 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754191AbbDOPcF (ORCPT ); Wed, 15 Apr 2015 11:32:05 -0400 Date: Wed, 15 Apr 2015 08:31:50 -0700 From: Guenter Roeck To: Quentin Casasnovas Cc: Rusty Russell , lkml , Stephen Rothwell , linux-next Subject: Re: [PATCH 0/2] Tentative fix for the divide-by-zero on score/paris/.. Message-ID: <20150415153150.GA1149@roeck-us.net> References: <20150414165000.GA19434@roeck-us.net> <1429088078-23827-1-git-send-email-quentin.casasnovas@oracle.com> <552E6722.1080507@roeck-us.net> <20150415134637.GB5947@chrystal.uk.oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150415134637.GB5947@chrystal.uk.oracle.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Authenticated_sender: guenter@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-CTCH-PVer: 0000001 X-CTCH-Spam: Unknown X-CTCH-VOD: Unknown X-CTCH-Flags: 0 X-CTCH-RefID: str=0001.0A020201.552E8474.03E8,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0 X-CTCH-Score: 0.000 X-CTCH-ScoreCust: 0.000 X-CTCH-Rules: X-CTCH-SenderID: linux@roeck-us.net X-CTCH-SenderID-Flags: 0 X-CTCH-SenderID-TotalMessages: 3 X-CTCH-SenderID-TotalSpam: 0 X-CTCH-SenderID-TotalSuspected: 0 X-CTCH-SenderID-TotalConfirmed: 0 X-CTCH-SenderID-TotalBulk: 0 X-CTCH-SenderID-TotalVirus: 0 X-CTCH-SenderID-TotalRecipients: 0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: mailgid no entry from get_relayhosts_entry X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2852 Lines: 75 On Wed, Apr 15, 2015 at 03:46:37PM +0200, Quentin Casasnovas wrote: > On Wed, Apr 15, 2015 at 06:26:58AM -0700, Guenter Roeck wrote: > > On 04/15/2015 01:54 AM, Quentin Casasnovas wrote: > > > > > > Let me know if this makes things better.. > > > > > Hi Guenter, > > > > > the crash is fixed, but now I get > > > > That's a first step.. :) > > > FATAL: The relocation at __ex_table+0x4 references > > [...] > > > > for parisc:defconfig, > > for score:allnoconfig, and > > for mn10300:defconfig. > > Thanks for the testing, much appreciated! > > > > > While I agree that those should get fixed (if they are real problems, > > especially the ones for parisc and mn10300), I don't think it is > > a good idea to fail the build because of it. > > That's a tough one.. I think it's pretty bad in general to have some > crufts in the ex_table referencing non-executable sections. Note that it > will not make the build fail if the relocation _seems_ legit (jump to an > executable section even though it's not part of the white-list) but in > those cases, something really does look wrong and could potentially have a > security impact so I thought the build failure was a good thing to do. > Hi Quentin, Guess we have a different philosophy; mine is "do no harm". > Now, if it's a problem in modpost (which is likely!), then obviously I'd be > happy to try and help fix that! > > > > > Note that I did find the problem in the score build; that was a real bug. > > I don't know what may be wrong with the others. > > Cool! Mind CC'ing me to your fix, I'm curious :) > I'll do that. > Regarding the others, if you've compiled them with debug information, you > should be able to do some addr2line magic incantation to find the offending > code. I've also added scripts/check_extable.sh which you might be able to > use to get more details about the failures (or simply use the same logic in > there to know where those maybe-wrong-relocations are coming from). > > I'm surprised/concerned that some sections appear to have no name though > (indicating yet another bug in my modpost changes?).. If you can share the > object files then I can have a look (and possibly help with the addr2line > incantation). > I don't really have time to do that; please keep in mind that I am not getting paid for this and do it in my free time. Both the parisc and mn10300 (am33) tool chains are available from kernel.org; it should be straightforward to install them and see yourself what is going on. Unlike score I did not find the problem in those architectures with code inspection. Thanks, Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/