From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754604AbcJZQpd (ORCPT ); Wed, 26 Oct 2016 12:45:33 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48466 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754027AbcJZQpc (ORCPT ); Wed, 26 Oct 2016 12:45:32 -0400 Date: Wed, 26 Oct 2016 11:45:30 -0500 From: Josh Poimboeuf To: Arnd Bergmann Cc: Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: [PATCH] objtool: fix rare switch jump table pattern detection Message-ID: <20161026164530.a7xzjtwk42ymfnqg@treble> References: <3971280.DNU2zoGODW@wuerfel> <20161026153408.2rifnw7bvoc5sex7@treble> <6240615.e5XfHPpyq8@wuerfel> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <6240615.e5XfHPpyq8@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]); Wed, 26 Oct 2016 16:45:31 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 26, 2016 at 06:03:44PM +0200, Arnd Bergmann wrote: > On Wednesday, October 26, 2016 10:34:08 AM CEST Josh Poimboeuf wrote: > > The following commit: > > > > 3732710ff6f2 ("objtool: Improve rare switch jump table pattern detection") > > > > ... improved objtool's ability to detect gcc switch statement jump > > tables for gcc 6. However the check to allow short jumps with the > > scanned range of instructions wasn't quite right. The pattern detection > > should allow jumps to the indirect jump instruction itself. > > > > This fixes the following warning: > > > > drivers/infiniband/sw/rxe/rxe_comp.o: warning: objtool: rxe_completer()+0x315: sibling call from callable instruction with changed frame pointer > > > > Reported-by: Arnd Bergmann > > Fixes: 3732710ff6f2 ("objtool: Improve rare switch jump table pattern detection") > > Signed-off-by: Josh Poimboeuf > > Tested-by: Arnd Bergmann > > It fixes the mlx4/resource_tracker.o problem, but not the other > one for ttusb-dec/ttusb_dec.o, as you mentioned. > > Do you need any more help creating a testcase for that one? No, I can recreate the ttusb_dec.o warning with the config you gave me for this one. Thanks! -- Josh