From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-Status: No, score=-4.2 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,MAILING_LIST_MULTI, SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server2.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id 2C2FA1F4B4 for ; Tue, 22 Sep 2020 18:04:46 +0000 (UTC) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 1560B3987863; Tue, 22 Sep 2020 18:04:45 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 1560B3987863 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1600797885; bh=kY+pTVNukcooNis7hCa58JtZHrUrpbW0ZWnmnD5bwRc=; h=To:Subject:References:Date:In-Reply-To:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=L03/dbd3MKdazYXroJxmicsZpW+XBygUDY6Ssifzg8IjzZo3qD52MCjznSQcz4ePY QovnaG2F4Kgf0UieHiMVtrPrTtdfBtlDqBq21bdqa+kituOqOUXOVwB02UTAhsZNX8 XktcfLo/Nvm3sMNXPrFxmPyZM6dT4iZO8Lih+DCE= 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) To: Carlos O'Donell 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-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: , From: Florian Weimer via Libc-alpha Reply-To: Florian Weimer Cc: Pedro Alves , "xe-linux-external\(mailer list\)" , Carlos O'Donell via Libc-alpha , "Jeremy Stenglein \(jstengle\)" Errors-To: libc-alpha-bounces@sourceware.org Sender: "Libc-alpha" * 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