From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by sourceware.org (Postfix) with ESMTP id 573FE3989C8F for ; Tue, 4 May 2021 12:27:14 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 573FE3989C8F 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-21-w8edaqYQPBWMdncB-BstJw-1; Tue, 04 May 2021 08:27:11 -0400 X-MC-Unique: w8edaqYQPBWMdncB-BstJw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 84A5D81461B; Tue, 4 May 2021 12:27:00 +0000 (UTC) Received: from oldenburg.str.redhat.com (ovpn-112-137.ams2.redhat.com [10.36.112.137]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 257F475E5F; Tue, 4 May 2021 12:26:58 +0000 (UTC) From: Florian Weimer To: "H.J. Lu" Cc: GNU C Library , Andreas Schwab Subject: Re: [RFC] elf: Implement filtering of symbols historically defined in libpthread References: <87h7jqguew.fsf@oldenburg.str.redhat.com> <87k0oeln6s.fsf@oldenburg.str.redhat.com> Date: Tue, 04 May 2021 14:27:13 +0200 In-Reply-To: (H. J. Lu's message of "Tue, 4 May 2021 05:24:06 -0700") Message-ID: <87wnsek7ku.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-6.8 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, 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, 04 May 2021 12:27:16 -0000 * H. J. Lu: >> The patch attempts to detect old main programs by looking for the >> GLIBC_2.34 symbol version. Since we added __libc_start_main@@GLIBC_2.34 >> (which is called from our version of _start), all standard main programs >> linked with glibc 2.34 or later will have this symbol version. > Can we invent a symbol or version to detect the older binaries? > If not, can GNU property, ABI note, .... help here? I think we have all we need due to __libc_start_main@@GLIBC_2.34. It was an unrelated change, but it helps here as well. Thanks, Florian