From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ignacy Gawedzki Subject: Attempt to auto-load em_cmp.ko results in negative module refcnt Date: Mon, 16 Feb 2015 11:59:12 +0100 Message-ID: <20150216105912.GA16798@zenon.in.qult.net> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-2 Content-Transfer-Encoding: QUOTED-PRINTABLE To: netdev@vger.kernel.org Return-path: Received: from [78.193.33.39] ([78.193.33.39]:57483 "EHLO mail.qult.net" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1755178AbbBPLAA (ORCPT ); Mon, 16 Feb 2015 06:00:00 -0500 Received: from zenon.in.qult.net ([192.168.64.1] helo=zenon) by mail.qult.net with esmtps (TLS1.2:RSA_AES_128_CBC_SHA1:128) (Exim 4.82) (envelope-from ) id 1YNJOr-0001Zp-48 for netdev@vger.kernel.org; Mon, 16 Feb 2015 11:59:37 +0100 Received: from ig by zenon with local (Exim 4.84_RC1) (envelope-from ) id 1YNJOS-0004h1-Fz for netdev@vger.kernel.org; Mon, 16 Feb 2015 11:59:12 +0100 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: Hi, This simple test case tc qdisc add dev eth0 root handle 1: htb tc class add dev eth0 root classid 1: htb rate 1Gbit tc class add dev eth0 parent 1: classid 1:1 htb rate 1Gbit tc filter add dev eth0 parent 1: basic match 'cmp(u8 at 0 eq 0)' clas= sid 1:1 fails with the following RTNETLINK answers: No such file or directory We have an error talking to the kernel if em_cmp.ko is not loaded beforehand. After that, lsmod shows that em_cmp.ko is loaded indeed, but its usage = count is -1 and an attempd to unload the module results in a "BUG at kernel/module.c:752". This has been broken pretty recently, I'm currently attempting a git bi= sect on this. --=20 Ignacy Gaw=EAdzki R&D Engineer Green Communications