From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751149AbdFAO3B (ORCPT ); Thu, 1 Jun 2017 10:29:01 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33862 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751090AbdFAO3A (ORCPT ); Thu, 1 Jun 2017 10:29:00 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com A390637EEC Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=jpoimboe@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com A390637EEC Date: Thu, 1 Jun 2017 09:28:58 -0500 From: Josh Poimboeuf To: Andy Lutomirski Cc: X86 ML , "linux-kernel@vger.kernel.org" , live-patching@vger.kernel.org, Linus Torvalds , Jiri Slaby , Ingo Molnar , "H. Peter Anvin" , Peter Zijlstra Subject: Re: [RFC PATCH 06/10] x86/entry: add CFI hint undwarf annotations Message-ID: <20170601142858.na6iph4ihpgcgold@treble> References: <1d852057ba39f2f5f02f196c604b8baecce33fea.1496293620.git.jpoimboe@redhat.com> <20170601142358.wvasu35pvyyvjt2r@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20170601142358.wvasu35pvyyvjt2r@treble> 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 [10.5.110.29]); Thu, 01 Jun 2017 14:28:59 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 01, 2017 at 09:23:58AM -0500, Josh Poimboeuf wrote: > On Thu, Jun 01, 2017 at 07:03:18AM -0700, Andy Lutomirski wrote: > > On Wed, May 31, 2017 at 10:44 PM, Josh Poimboeuf wrote: > > Just to make sure I understand this, if we unwind from... > > > > > @@ -112,6 +114,7 @@ For 32-bit we have the following conventions - kernel is built with > > > movq %rdx, 12*8+\offset(%rsp) > > > movq %rsi, 13*8+\offset(%rsp) > > > > ...here..., will objtool think that rdx and rsi (etc) still live in > > their respective regs, or will it find them in the on-stack data given > > by CFI_REGS? If the former, how does undwarf deal with the > > corresponding pops? > > It will find them in their respective registers, which is fine because > they haven't been clobbered yet. Sorry, I hit send too soon. Which pops are you referring to? -- Josh