From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753232AbcJKMUw (ORCPT ); Tue, 11 Oct 2016 08:20:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48642 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751647AbcJKMUv (ORCPT ); Tue, 11 Oct 2016 08:20:51 -0400 Date: Tue, 11 Oct 2016 07:20:49 -0500 From: Josh Poimboeuf To: Arnd Bergmann Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] [RFC] x86: avoid -mtune=atom for objtool warnings Message-ID: <20161011122049.mllgy4e5z74xg4js@treble> References: <20161010125709.1870563-1-arnd@arndb.de> <20161010202322.labiotb5dsf4oyfi@treble> <1855683.1QnG4Fe4Hq@wuerfel> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1855683.1QnG4Fe4Hq@wuerfel> User-Agent: Mutt/1.6.0.1 (2016-04-01) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Tue, 11 Oct 2016 12:20:51 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 11, 2016 at 10:08:12AM +0200, Arnd Bergmann wrote: > On Monday, October 10, 2016 3:23:22 PM CEST Josh Poimboeuf wrote: > > > > Thanks for reporting it. It looks like 'mtune=atom' sometimes makes a > > slight change to one of the stack frame setup instructions. Instead of: > > > > move rsp, rbp > > > > It sometimes does: > > > > lea (%rsp),%rbp > > > > They're two different instructions, but they have the same result. It's > > an easy fix for objtool. I'll post a patch soon. > > > > > > Ah, good to hear. I've replaced my patch with yours in my randconfig > tests now and will let you know if there are any other warnings on > atom. I've done a few thousand x86 randconfig builds now and done private > patches for all warnings I got (I previously had fixes only for the arm > warnings). I found objtool warnings for a few files in some configurations > that do not involve -mtune=atom, maybe you can also look at what > is going on there as I have no idea for how to address them: > > drivers/scsi/fnic/fnic_main.o: warning: objtool: fnic_log_q_error() falls through to next function fnic_handle_link_event() > drivers/scsi/snic/snic_res.o: warning: objtool: .text: unexpected end of section > drivers/infiniband/sw/rxe/rxe_comp.o: warning: objtool: rxe_completer()+0x2f3: sibling call from callable instruction with changed frame pointer > drivers/infiniband/sw/rxe/rxe_resp.o: warning: objtool: rxe_responder()+0x10f: sibling call from callable instruction with changed frame pointer > kernel/locking/rwsem.o: warning: objtool: down_write_killable()+0x16: call without frame pointer save/setup > > I can provide additional information for reproducing them if it's > not immediately obvious what the problems are. I'm really surprised the 0-day bot didn't find these. I was under the impression that it continuously did a bunch of randconfigs. Anyway, if you could send the configs for the warnings, that would be very helpful. I also happen to be working on a significant rewrite of objtool and these configs will come in handy for making a regression suite. -- Josh