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 [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id E64223858D28 for ; Sat, 18 Dec 2021 20:08:14 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org E64223858D28 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-503-PgkrRLzpNUK9czdkT669iA-1; Sat, 18 Dec 2021 15:08:11 -0500 X-MC-Unique: PgkrRLzpNUK9czdkT669iA-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 834E78042EA; Sat, 18 Dec 2021 20:08:10 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.192.46]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2A9265BD17; Sat, 18 Dec 2021 20:08:08 +0000 (UTC) From: Florian Weimer To: Adhemerval Zanella Cc: libc-alpha@sourceware.org, John Mellor-Crummey , Ben Woodard Subject: Re: [PATCH v6 15/20] elf: Run constructors if executable has a soname of a dependency References: <20211115183734.531155-1-adhemerval.zanella@linaro.org> <20211115183734.531155-16-adhemerval.zanella@linaro.org> Date: Sat, 18 Dec 2021 21:08:06 +0100 In-Reply-To: <20211115183734.531155-16-adhemerval.zanella@linaro.org> (Adhemerval Zanella's message of "Mon, 15 Nov 2021 15:37:29 -0300") Message-ID: <874k75he1l.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=-6.5 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_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) 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: Sat, 18 Dec 2021 20:08:16 -0000 * Adhemerval Zanella: > The DSO constructor should not be ignored if the main executable > has the SONAME set to a dependency. It fixes the case where > (using the scripts/dso-ordering-test.py definition): > > {}->a->b->c;soname({})=c > > Where the constructors should return > > c>b>a>{} Date: Fri Dec 11 17:30:03 2020 +0100 elf: Include libc.so.6 as main program in dependency sort (bug 20972) _dl_map_object_deps always sorts the initially loaded object first during dependency sorting. This means it is relocated last in dl_open_worker. This results in crashes in IFUNC resolvers without lazy bindings if libraries are preloaded that refer to IFUNCs in libc.so.6: the resolvers are called when libc.so.6 has not been relocated yet, so references to _rtld_global_ro etc. crash. The fix is to check against the libc.so.6 link map recorded by the __libc_early_init framework, and let it participate in the dependency sort. This fixes bug 20972. Reviewed-by: Carlos O'Donell Is it a more general/correct version of this commit? But if the main program has a soname, wouldn't we stop loading it as a dependency, too? So that the expected ouptut turns into: b>a>{}