From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 27BEEC433DB for ; Thu, 28 Jan 2021 12:56:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D966564D9D for ; Thu, 28 Jan 2021 12:56:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231618AbhA1M4V (ORCPT ); Thu, 28 Jan 2021 07:56:21 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:28439 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231465AbhA1M4U (ORCPT ); Thu, 28 Jan 2021 07:56:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611838494; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=MtBbADQiuUSQfzo63sc+64I9NQT25rWvLSQFMMQtrLU=; b=YcuoUX5/R31/6x7TLxZoArVRR2aS3UMRUPZf8A0TPkTzTYjJOsyJiDBeIvEeuRF+5xhrmX tsZPDyEpJVB+hZHgSS+fc/39Fo87FE3RPunRG99uYzBdPnjTB0I/hbVYIlJ3XOMqeqE0ai fNrzBObZLH0JQcvyDd85kBrUPVGUYk4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-19-iCTKjoaAPoCMCd_Cp56EsA-1; Thu, 28 Jan 2021 07:54:49 -0500 X-MC-Unique: iCTKjoaAPoCMCd_Cp56EsA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BF36D107ACE6; Thu, 28 Jan 2021 12:54:48 +0000 (UTC) Received: from redhat.com (ovpn-115-133.ams2.redhat.com [10.36.115.133]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E6BAA6064B; Thu, 28 Jan 2021 12:54:46 +0000 (UTC) Date: Thu, 28 Jan 2021 12:54:43 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Arnaldo Carvalho de Melo Cc: Mark Wielaard , dwarves@vger.kernel.org Subject: Re: [PATCH/RFC] Re: DWARF5 DW_AT_data_bit_offset Message-ID: <20210128125443.GI3832029@redhat.com> Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= References: <5ee85ca6e3b06b07c83b150912fbcfc1a4c13e19.camel@klomp.org> <20201002211819.GA127275@kernel.org> <20210121113516.GA8492@wildebeest.org> <20210128121122.GA775562@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210128121122.GA775562@kernel.org> User-Agent: Mutt/1.14.6 (2020-07-11) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: dwarves@vger.kernel.org On Thu, Jan 28, 2021 at 09:11:22AM -0300, Arnaldo Carvalho de Melo wrote: > Em Thu, Jan 21, 2021 at 12:35:16PM +0100, Mark Wielaard escreveu: > > On Fri, Oct 02, 2020 at 06:18:19PM -0300, Arnaldo Carvalho de Melo wrote: > > > Em Fri, Oct 02, 2020 at 06:11:06PM +0200, Mark Wielaard escreveu: > > > > Seems pahole with a recent version of elfutils libdw already handles > > > > most DWARF5 encodings. One thing it doesn't handle yet is > > > > DW_AT_data_bit_offset (this is actually a DWARF4 thing, but gcc only > > > > emits it for -gdwarf-5). > > > > > > > $ gcc -gdwarf-5 -c bf.c > > > > $ ./pahole ./bf.o > > > > DW_AT_<0xd>=0x21 > > > > DW_AT_<0xd>=0x21 > > > > DW_AT_<0xd>=0x21 > > > > struct pea { > > > > int type; /* 0 4 */ > > > > static long int a; /* 0 0 */ > > > > static long int b; /* 0 0 */ > > > > static long int c; /* 0 0 */ > > > > > > > > /* size: 8, cachelines: 1, members: 1, static members: 3 */ > > > > /* padding: 4 */ > > > > /* last cacheline: 8 bytes */ > > > > }; > > > > > Note that GCC11 might default to DWARF5. > > > > Thanks for the detailed report, I'm releasing v1.18 right now, will look > > > into that for v1.19. > > > Note that GCC11 indeed just switched to producing DWARF5 by default. > > It is not released yet, but already in stage4 and Fedora will start > > doing a mass-rebuild with it soon to shake out the last remaining bugs. > > So, 1.20 will have the fix below, please check if what is in: > > https://git.kernel.org/pub/scm/devel/pahole/pahole.git/log/?h=DW_AT_data_bit_offset > > Fixes it for you, the cset with all the tests performed is this one: > > https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?h=DW_AT_data_bit_offset&id=a77f039bb49bc97badf938049245f013fe3de4aa > > Now looking at https://bugzilla.redhat.com/show_bug.cgi?id=1919965 ... The XDR generated code example I give in that bug *does* appear to be fixed when using your DW_AT_data_bit_offset branch. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|