From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934084AbdBQNgV (ORCPT ); Fri, 17 Feb 2017 08:36:21 -0500 Received: from mail-wr0-f195.google.com ([209.85.128.195]:35277 "EHLO mail-wr0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933545AbdBQNgU (ORCPT ); Fri, 17 Feb 2017 08:36:20 -0500 Subject: Re: [PREVIEW 10/10] linkage: add .cfi_{start/end}proc to ENTRY/ENDPROC To: Josh Poimboeuf References: <20170217104757.28588-1-jslaby@suse.cz> <20170217104757.28588-10-jslaby@suse.cz> <20170217131602.pxrgfaeaanrzymnv@treble> Cc: mingo@redhat.com, tglx@linutronix.de, hpa@zytor.com, x86@kernel.org, linux-kernel@vger.kernel.org From: Jiri Slaby Message-ID: Date: Fri, 17 Feb 2017 14:36:15 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.7.0 MIME-Version: 1.0 In-Reply-To: <20170217131602.pxrgfaeaanrzymnv@treble> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/17/2017, 02:16 PM, Josh Poimboeuf wrote: > On Fri, Feb 17, 2017 at 11:47:57AM +0100, Jiri Slaby wrote: >> This is just a preview, not to merged now, only later with DWARF >> unwinder series. This is what the series will serve for (aside from >> cleanup and unification). >> >> I am aware of CFI_STARTPROC and CFI_ENDPROC left defined in other archs >> in spite of cfi annotations removal ages ago. For simplicity. I am using >> DW_ prefix here. > > If objtool is going to be generating CFI instructions, why not have it > generate .cfi_startproc and .cfi_endproc too? I tried that, but in many places it is very hard to recognize start and/or end of a function. Having .cfi_startproc and .cfi_endproc in place makes it rather easy, actually reduced to "emit dwarf instructions for this code between here and there". Plus pre-prepared .eh_frame only to be extended. (.eh_frame_hdr has to be rehashed of course.) thanks, -- js suse labs