From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.8 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED, SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.1 Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id 39F2C1F404 for ; Thu, 16 Aug 2018 13:00:53 +0000 (UTC) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:subject:to:references:cc:from:message-id:date :mime-version:in-reply-to:content-type :content-transfer-encoding; q=dns; s=default; b=OlKR5rhsPWhGTCBT Yq0JXQ3j+OqglMhaLtIfmIsGSXmCBPjHO2oSoA9wqPSevSvU0bmqVxenvqdVKRpU 3VJvGoW5HIQJ04y68NHqbAq+ZzR6ujwiKc+zSHA6HQaakYaRSQL3U1JAT5L5VC5V RCkrPSb1E/ah+03/kDE5qwZXNDk= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:subject:to:references:cc:from:message-id:date :mime-version:in-reply-to:content-type :content-transfer-encoding; s=default; bh=93Px/QaG4/o32259YHMNfg tC6Sg=; b=heiF9Yp5Jl0Zyy68GWLFm1JqYRd8dUITwRCq4SupNRMDZR9bS3PRpv R0iJ0P/nMQF9i81lr5LrI/JXW9nMClqLtgtRNs3s2lh5xlAj6kQFymeasZO1W+fT iHbS87uhyZI8HpQ5Sak+FO+Nf3/Dcpbv0nkLEDGDj3pGI5suDovm8= Received: (qmail 93227 invoked by alias); 16 Aug 2018 13:00:39 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 92976 invoked by uid 89); 16 Aug 2018 13:00:24 -0000 Authentication-Results: sourceware.org; auth=none X-HELO: mx1.redhat.com Subject: PT_NOTE alignment, NT_GNU_PROPERTY_TYPE_0, glibc and gold (was: Re: [PATCH] Document GNU_PROPERTY_X86_ISA_1_[USED|NEEDED]) To: "H.J. Lu" References: Cc: x86-64-abi@googlegroups.com, Binutils , GNU C Library From: Florian Weimer Message-ID: <13a92cb0-a993-f684-9a96-e02e4afb1bef@redhat.com> Date: Thu, 16 Aug 2018 15:00:03 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit On 08/07/2018 10:41 PM, H.J. Lu wrote: > The .note.gnu.property section with NT_GNU_PROPERTY_TYPE_0 has been > added to Linux Extensions to gABI: > > https://github.com/hjl-tools/linux-abi > > GNU_PROPERTY_X86_ISA_1_USED and GNU_PROPERTY_X86_ISA_1_NEEDED are > processor-specific program property types for i386 and x86-64. The specification is incomplete as far as alignment matters are concerned. Is the link editor supposed to maintain separate segments for notes with different alignments? Or is it possible to merge the notes into a single segment, potentially after adjusting alignment? Is the link editor *required* to produce 8-byte alignment for notes in ELFCLASS64 objects? Currently, we do not have agreement between binutils (particularly gold) and the glibc dynamic loader when it comes to alignment of PT_NOTE segments. glibc will disregard property notes in ELFCLASS64 objects which have 4-byte alignment, but gold produces such notes. This needs to be fixed. Thanks, Florian