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-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, 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 600981F4B4 for ; Fri, 18 Sep 2020 15:40:45 +0000 (UTC) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 381C3395445A; Fri, 18 Sep 2020 15:40:44 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 381C3395445A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1600443644; bh=nUm/2Ax4Mi3M3OMjQ06HTXtOLdlVnGwfnaxYh0gKbbE=; 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=YD8z2HQiFyuzhUfAfYE86Wb02NZUUAD047x5HpP3KWlIIieVCmz4l9c5qEqarPXKq n0HPyiwfRgBv2GZBYQQJxtyK6O+7frLqXlko/LqoIgkDWWCGYuvM3EOxJ83Fe0Drqw e5KC5hZNfLQSZ642IeLMdSnKupLuh73pYHdLtNb0= Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) by sourceware.org (Postfix) with ESMTP id 92EB2395445A for ; Fri, 18 Sep 2020 15:40:41 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 92EB2395445A 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-96-R4UKCA-ePVe38dsQZrqZlg-1; Fri, 18 Sep 2020 11:40:38 -0400 X-MC-Unique: R4UKCA-ePVe38dsQZrqZlg-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 309958030AC; Fri, 18 Sep 2020 15:40:37 +0000 (UTC) Received: from oldenburg2.str.redhat.com (ovpn-113-177.ams2.redhat.com [10.36.113.177]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 870B968876; Fri, 18 Sep 2020 15:40:32 +0000 (UTC) To: "Daniel Walker (danielwa)" Subject: Re: [RFC PATCH 0/3] implement dlmopen hooks for gdb References: <20200626193228.1953-1-danielwa@cisco.com> <0f791d3a-20bc-4524-54eb-ce6df108fbff@redhat.com> <20200723184054.GD9875@zorba> <3ff42e45-b394-bf50-38c4-93baecc71497@redhat.com> <20200916161836.GW7261@zorba> <85ee3ea9-039b-a5db-a84e-224924822c79@redhat.com> <871rj0imo8.fsf@oldenburg2.str.redhat.com> <5ce2d889-9eea-4c53-8bba-d8216f2bf513@redhat.com> <20200918153543.GX7261@zorba> Date: Fri, 18 Sep 2020 17:40:30 +0200 In-Reply-To: <20200918153543.GX7261@zorba> (Daniel Walker's message of "Fri, 18 Sep 2020 15:35:43 +0000") Message-ID: <87imcb3xg1.fsf@oldenburg2.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (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-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: "Nikola Tesic -X \(ntesic - SYRMIA DOO NOVI SAD at Cisco\)" , "libc-alpha@sourceware.org" , Pedro Alves , "Jeremy Stenglein \(jstengle\)" , "xe-linux-external\(mailer list\)" Errors-To: libc-alpha-bounces@sourceware.org Sender: "Libc-alpha" * Daniel Walker: > On Thu, Sep 17, 2020 at 09:53:30AM -0400, Carlos O'Donell wrote: >> On 9/17/20 8:59 AM, Florian Weimer wrote: >> > * Carlos O'Donell: >> > >> >> You will always have .dynsym with a definition for _r_debug_dlmopen. >> > >> > Note that this doesn't work if you just have a core file. In order to >> > find _r_debug (or _r_debug_dlmopen), a debugger needs the exact same >> > copy of ld.so that was used by the executable, otherwise the symbol >> > cannot be found in the image. >> >> You are correct. >> >> I followed up on my own email regarding this. >> >> So in the end to get process and core file debugging we'll need: >> >> * _r_debug_dlmopen >> * DT_DEBUG_DLMOPEN >> > > It seems like adding DT_DEBUG_DLMOPEN into the gABI might take some > effort. Have you considered this ? The last one which was added was > DT_SYMTAB_SHNDX in 2018, and it looks like it did not come from glibc. We are reviving GNU gABI maintenance. There's been quite a bit of list activity, and a proposal of a first ABI document: I have a feeling that we might be soon over this bump, and getting things added should become easier. In the meantime, can we demo this feature without DT_DEBUG_DLMOPEN? With a patch glibc and gdb? Incidentally, I have an LD_AUDIT issue I need to debug. 8-) Thanks, Florian -- Red Hat GmbH, https://de.redhat.com/ , Registered seat: Grasbrunn, Commercial register: Amtsgericht Muenchen, HRB 153243, Managing Directors: Charles Cachera, Brian Klemm, Laurie Krebs, Michael O'Neill