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=-6.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 976BEC433E2 for ; Tue, 8 Sep 2020 09:04:37 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5780D21741 for ; Tue, 8 Sep 2020 09:04:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5780D21741 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kFZYB-0007Lo-MP; Tue, 08 Sep 2020 09:04:27 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kFZYA-0007Lh-7i for xen-devel@lists.xenproject.org; Tue, 08 Sep 2020 09:04:26 +0000 X-Inumbo-ID: 94d759e3-b179-43c3-b00d-9209770666d9 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 94d759e3-b179-43c3-b00d-9209770666d9; Tue, 08 Sep 2020 09:04:25 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 64AFFABB2; Tue, 8 Sep 2020 09:04:25 +0000 (UTC) Subject: Re: [PATCH v3 1/4] x86/xen.lds.S: Work around binutils build id alignment bug To: Trammell Hudson References: <20200907190027.669086-1-hudson@trmm.net> <20200907190027.669086-2-hudson@trmm.net> Cc: xen-devel@lists.xenproject.org, Andrew Cooper , Wei Liu , =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= From: Jan Beulich Message-ID: <5b8f533d-c646-8a52-cf37-d21b182ccf9b@suse.com> Date: Tue, 8 Sep 2020 11:04:25 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <20200907190027.669086-2-hudson@trmm.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On 07.09.2020 21:00, Trammell Hudson wrote: > --- a/xen/arch/x86/xen.lds.S > +++ b/xen/arch/x86/xen.lds.S > @@ -156,6 +156,7 @@ SECTIONS > __note_gnu_build_id_end = .; > } :note :text > #elif defined(BUILD_ID_EFI) > + . = ALIGN(32); /* workaround binutils section overlap bug */ > DECL_SECTION(.buildid) { > __note_gnu_build_id_start = .; > *(.buildid) It being "just" 32 bytes may make it look as if we could take this without much thinking, but I'm then struggling where we would draw the boundary. The binutils bug having got fixed (or at least worked around), I don't really like this getting applied uniformly, the more that nothing would normally have the requirement you have (to be able to objcopy the whole thing). Personally I think this kind of a workaround patch is something distros ought to be fine to carry, if they care about the functionality and only until they get around to upgrade their binutils. But I'll be happy to hear differing opinions. I also don't see any mention anywhere of why it's 32 bytes, and not 16 or 64 or yet something else. Finally, please Cc maintainers on patch submissions. Jan