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 9AE6F3854812 for ; Tue, 18 May 2021 15:04:36 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 9AE6F3854812 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-99-epk3mSk1Nua_xf5ponyHhg-1; Tue, 18 May 2021 11:04:34 -0400 X-MC-Unique: epk3mSk1Nua_xf5ponyHhg-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 682898049CB; Tue, 18 May 2021 15:04:33 +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 901481349A; Tue, 18 May 2021 15:04:32 +0000 (UTC) From: Florian Weimer To: Andreas Schwab Cc: Florian Weimer via Libc-alpha Subject: Re: [PATCH 00/10] nptl: Complete libpthread removal References: <87eee4ccpd.fsf@igel.home> Date: Tue, 18 May 2021 17:04:30 +0200 In-Reply-To: <87eee4ccpd.fsf@igel.home> (Andreas Schwab's message of "Tue, 18 May 2021 16:56:46 +0200") Message-ID: <87v97g5bi9.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 10.5.11.11 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-6.7 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, 18 May 2021 15:04:38 -0000 * Andreas Schwab: > On Mai 18 2021, Florian Weimer via Libc-alpha wrote: > >> We need to provide libpthread.so.0 stub object for use with >> memusagestat, otherwise a system libpthread.so.0 might leak into the >> link. Not loading libpthread.so.0 is hacked directly into the dynamic >> loader. > > What would happen if the lpthread stub would be loaded? I made sure that it crashes: /* Produce an invalid init function, so that loading the stub crashes. */ .section .init_array,"a",%init_array .dc.a 4096 I tried adding an undefined symbol, but that make the stub unusable as a stub, too. Neither binutils nor glibc currently support DF_1_STUB, so that's not an option. Thanks, Florian