From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca by simark.ca with LMTP id DwOnFw27eWBXFwAAWB0awg (envelope-from ) for ; Fri, 16 Apr 2021 12:27:57 -0400 Received: by simark.ca (Postfix, from userid 112) id 550531F104; Fri, 16 Apr 2021 12:27:57 -0400 (EDT) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on simark.ca X-Spam-Level: X-Spam-Status: No, score=-0.7 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,RDNS_DYNAMIC,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (ip-8-43-85-97.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 (2048 bits) server-digest SHA256) (No client certificate requested) by simark.ca (Postfix) with ESMTPS id B05AD1E01F for ; Fri, 16 Apr 2021 12:27:56 -0400 (EDT) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 16F69398B41B; Fri, 16 Apr 2021 16:27:56 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 16F69398B41B DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1618590476; 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=vSYDfNSxArWGPJUFvA/NfGq9Dmrp6PFkrMrxp7STCyRYlvKlW15w1UiojK7p+/3TX 0JrUQMeWtqYW6tGkFI6G8SKeZEwAdXah2/FnPa8Q0o3zFicOrTE2HT8Z6c7frXI8yM uCiyR2DjoxEVB2d9+xdabBVubIS11Y76oRAoFQVE= 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 A6BD23893656 for ; Fri, 16 Apr 2021 16:27:53 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org A6BD23893656 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: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Florian Weimer via Gdb-patches Reply-To: Florian Weimer Cc: Emil Velikov , libc-alpha@sourceware.org, gdb-patches@sourceware.org Errors-To: gdb-patches-bounces@sourceware.org Sender: "Gdb-patches" * 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