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-ASN: AS17314 8.43.84.0/22 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, RCVD_IN_DNSWL_MED,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 3E0DB1F4B4 for ; Fri, 16 Apr 2021 16:27:55 +0000 (UTC) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 3229E39730F7; Fri, 16 Apr 2021 16:27:54 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 3229E39730F7 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1618590474; bh=9fHntgIhIOYGtwrGDqiafIvm1WdaF7cfM4dMH9MrdB8=; 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=H8sZ1CiXcIWxd21P4xrHBbwljp/uBauUlhzk1oJobMnYx+FuYOY2DKQwkOXNBlgss zP71AcpQ3FsQgQyNV3X29zGjG3BQXsB2fJOWJofsZOiQVm3OfIwPJOh6Jg+eyEmzDl LIqkFCXn5vRohpcDgbUsdSxLgyziQeJC7TcLph24= 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 A691738930F3 for ; Fri, 16 Apr 2021 16:27:51 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org A691738930F3 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-275-25Iriy9tPPOHcpEL31EBzw-1; Fri, 16 Apr 2021 12:27:49 -0400 X-MC-Unique: 25Iriy9tPPOHcpEL31EBzw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6962A107ACCA; Fri, 16 Apr 2021 16:27:48 +0000 (UTC) Received: from oldenburg.str.redhat.com (ovpn-113-139.ams2.redhat.com [10.36.113.139]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BE0115D6D3; Fri, 16 Apr 2021 16:27:46 +0000 (UTC) To: Pedro Alves Subject: Re: [PATCH glibc] nptl_db: different libpthread/ld.so load orders (bug 27744) References: <87sg3qnrz3.fsf@oldenburg.str.redhat.com> <73b32cc6-e201-8bac-e442-e3dddcc01e0d@polymtl.ca> <625ec5fe-bd09-860a-f617-745042b94011@redhat.com> Date: Fri, 16 Apr 2021 18:28:04 +0200 In-Reply-To: <625ec5fe-bd09-860a-f617-745042b94011@redhat.com> (Pedro Alves's message of "Fri, 16 Apr 2021 17:25:15 +0100") Message-ID: <87fszqnqi3.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 10.5.11.15 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: libc-alpha@sourceware.org, gdb-patches@sourceware.org, Simon Marchi , Kevin Buettner Errors-To: libc-alpha-bounces@sourceware.org Sender: "Libc-alpha" * Pedro Alves: > IIRC, the order which libraries are loaded by GDB hasn't changed. The > issue is that until recently (before glibc 1daccf403b1b), the stacks > lists lived in libpthread (stack_used/__stack_user), so the fact that > GDB loaded libthread_db.so before ld.so's symbols were loaded didn't > make a difference. Now they were moved to ld.so, so libthread_db.so > can't find them until GDB reads the ld.so symbols. Is this assessment > correct? Yes, I believe this is what happens. I assume that ldd shows objects in link map order, the it looks like this: $ ldd /usr/bin/python3 linux-vdso.so.1 (0x00007fff1f8d5000) libpython3.9.so.1.0 => /lib64/libpython3.9.so.1.0 (0x00007f3fd7782000) libc.so.6 => /lib64/libc.so.6 (0x00007f3fd75b7000) libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f3fd7595000) libdl.so.2 => /lib64/libdl.so.2 (0x00007f3fd758e000) libutil.so.1 => /lib64/libutil.so.1 (0x00007f3fd7589000) libm.so.6 => /lib64/libm.so.6 (0x00007f3fd7443000) /lib64/ld-linux-x86-64.so.2 (0x00007f3fd7af7000) Thanks, Florian