From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-1.mimecast.com (us-smtp-delivery-1.mimecast.com [207.211.31.120]) by sourceware.org (Postfix) with ESMTP id 31738398784C for ; Tue, 22 Sep 2020 18:04:43 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 31738398784C 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-575-tq4KabhwNN6op8l0Pyv1CQ-1; Tue, 22 Sep 2020 14:04:40 -0400 X-MC-Unique: tq4KabhwNN6op8l0Pyv1CQ-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 42DF31017DCA; Tue, 22 Sep 2020 18:04:39 +0000 (UTC) Received: from oldenburg2.str.redhat.com (ovpn-114-108.ams2.redhat.com [10.36.114.108]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B875278830; Tue, 22 Sep 2020 18:04:32 +0000 (UTC) From: Florian Weimer To: Carlos O'Donell Cc: Carlos O'Donell via Libc-alpha , "Daniel Walker (danielwa)" , Pedro Alves , "Jeremy Stenglein (jstengle)" , "xe-linux-external(mailer list)" Subject: Re: [RFC PATCH 0/3] implement dlmopen hooks for gdb References: <20200626193228.1953-1-danielwa@cisco.com> <0f791d3a-20bc-4524-54eb-ce6df108fbff@redhat.com> <20200723184054.GD9875@zorba> <3ff42e45-b394-bf50-38c4-93baecc71497@redhat.com> <87h7rpwxke.fsf@oldenburg2.str.redhat.com> <87y2l1vhkn.fsf@oldenburg2.str.redhat.com> Date: Tue, 22 Sep 2020 20:04:31 +0200 In-Reply-To: (Carlos O'Donell's message of "Tue, 22 Sep 2020 13:59:09 -0400") Message-ID: <87h7rpvgb4.fsf@oldenburg2.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-7.2 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Sep 2020 18:04:44 -0000 * Carlos O'Donell: >> No, unlike GLIBC_PRIVATE, you can assume that if a GLIBC_DEBUG symbol is >> there (and perhaps has the documented size), it has the documented >> semantics. But you can't assume that it is present. >> >> The semantics of GLIBC_PRIVATE symbols can change arbitrarily, even >> between builds. > > Yes, absolutely, I agree completely, for it to be useful the semantics > have to be: > > - If you detect a given symbol foo@GLIBC_DEBUG, then the feature is > present and has the semantics you expect. > > - If you want new semantics then you need to make a foo2@GLIBC_DEBUG > with the new semantics. > > What are the runtime semantics of the symbol? How do you access it? That obviously depends on the symbol? Sorry, I don't quite understand these questions. Thanks, Florian -- Red Hat GmbH, https://de.redhat.com/ , Registered seat: Grasbrunn, Commercial register: Amtsgericht Muenchen, HRB 153243, Managing Directors: Charles Cachera, Brian Klemm, Laurie Krebs, Michael O'Neill