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 AFAC13858431 for ; Fri, 17 Dec 2021 02:56:42 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org AFAC13858431 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-647-kRwrwvLuMgGB611fxiAwBw-1; Thu, 16 Dec 2021 21:56:39 -0500 X-MC-Unique: kRwrwvLuMgGB611fxiAwBw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5A58F81CCB4; Fri, 17 Dec 2021 02:56:38 +0000 (UTC) Received: from redhat.com (unknown [10.2.16.5]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 3EB6878A95; Fri, 17 Dec 2021 02:56:38 +0000 (UTC) Received: from [127.0.0.1] (helo=vm-rhel7) by redhat.com with esmtp (Exim 4.94.2) (envelope-from ) id 1my3QC-0001wi-PE; Thu, 16 Dec 2021 21:56:37 -0500 From: fche@redhat.com (Frank Ch. Eigler) To: Matt Vibrys Cc: systemtap@sourceware.org Subject: Re: non-working .return probepoint from modules Date: Thu, 16 Dec 2021 21:33:39 -0500 References: Message-ID: <87mtl0aqhn.fsf@redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-6.2 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: systemtap@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Systemtap mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Dec 2021 02:56:44 -0000 >> The output below provides function calls, but it's silent about it's >> returns. Why so?: Good question, I wonder too! >> gmm@MY-HOST:~/user$ sudo /opt/systemtap-4.6/bin/stap -vv /home/gmm/user/scripts/drm.stp >> Systemtap translator/driver (version 4.6/0.176, non-git sources) >> [...] This is good, it contains the module-insertion fix PR28557. The stap console trace looks okay. > For better insight I've used drm module drm_ioctl function > instead. The problem persists, ie .return "locks nothing": > #+begin_src systemtap > probe module("drm").function("drm_ioctl") > { > printf("-->. %s %s %s\n", thread_indent(0), ppfunc(), $$parms); > } > > probe module("drm").function("drm_ioctl").return > { > printf("<--\n"); > } Would you consider rerunning a bit more pass-5 runtime side tracing such as % sudo stap -DDEBUG_KPROBES -DDEBUG_SYMBOLS [...] - FChE