From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 117604 invoked by alias); 27 Sep 2018 12:42:55 -0000 Mailing-List: contact gnu-gabi-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Post: List-Help: List-Subscribe: Sender: gnu-gabi-owner@sourceware.org Received: (qmail 117580 invoked by uid 89); 27 Sep 2018 12:42:55 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Checked: by ClamAV 0.100.1 on sourceware.org X-Virus-Found: No X-Spam-SWARE-Status: No, score=-0.9 required=5.0 tests=BAYES_00,KAM_LAZY_DOMAIN_SECURITY,SPF_HELO_PASS autolearn=no version=3.3.2 spammy=Hx-languages-length:896 X-Spam-Status: No, score=-0.9 required=5.0 tests=BAYES_00,KAM_LAZY_DOMAIN_SECURITY,SPF_HELO_PASS autolearn=no version=3.3.2 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on sourceware.org X-Spam-Level: X-Spam-User: qpsmtpd, 2 recipients X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 27 Sep 2018 12:42:54 +0000 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 59FFF44835; Thu, 27 Sep 2018 12:42:52 +0000 (UTC) Received: from oldenburg.str.redhat.com (ovpn-116-50.ams2.redhat.com [10.36.116.50]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AF10730918A2; Thu, 27 Sep 2018 12:42:50 +0000 (UTC) From: Florian Weimer To: "H.J. Lu" Cc: Szabolcs Nagy , Jan Beulich , Rich Felker , Binutils , gnu-gabi@sourceware.org Subject: Re: RFC: Add SHT_GNU_PHDRS References: <87tvmbv8hp.fsf@oldenburg.str.redhat.com> <5BAC7D6802000078001EC6D1@prv1-mh.provo.novell.com> <87pnwzuz8r.fsf@oldenburg.str.redhat.com> <20180927103539.GJ10209@port70.net> Date: Mon, 01 Jan 2018 00:00:00 -0000 In-Reply-To: (H. J. Lu's message of "Thu, 27 Sep 2018 05:37:27 -0700") Message-ID: <87va6rqfg6.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.84 on 10.5.11.24 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Thu, 27 Sep 2018 12:42:52 +0000 (UTC) X-IsSubscribed: yes X-SW-Source: 2018-q3/txt/msg00016.txt.bz2 * H. J. Lu: > On Thu, Sep 27, 2018 at 3:35 AM, Szabolcs Nagy wrote: >> an alloc .phdr section covering the program headers solves >> this problem. if sections are not required for segments >> then simply the linker should ensure that there is always >> a load segment covering the program headers, possibly >> without containing any sections, however elf says >> "An object file segment contains one or more sections". >> >> i don't understand why a zero-size section is enough, what >> if phdr > pagesize? will that get covered by the load >> segment that is created for the zero-size section? > > Linker must keep this zero-size section in output and > create a PT_LOAD segment to cover it even if it is > the only SHF_ALLOC section in the PT_LOAD segment. Based on Szabolcs' comment, I don't think the section can be zero-sized. Thanks, Florian