From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 54157C432C0 for ; Thu, 21 Nov 2019 19:50:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1CDBB20643 for ; Thu, 21 Nov 2019 19:50:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="SkmYuTDF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726909AbfKUTuS (ORCPT ); Thu, 21 Nov 2019 14:50:18 -0500 Received: from vps0.lunn.ch ([185.16.172.187]:50234 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726379AbfKUTuS (ORCPT ); Thu, 21 Nov 2019 14:50:18 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=idWpHQ/nnw+4hOuXenxT8j2yx3qPjOnf1q6Eq3KqWUM=; b=SkmYuTDF0Z/Nyn4W1aaPwWN/ag +jBgzLFgxMI0FOqyr15NFjRdVza41fVD0cOoYmz5QwKaqGRQ29LMbWA1ETw1DkKzlvG2+vCAgiBUR 7KYoJH/VFtNUdp2Y2/DJDE5Y+kOuSqMWMUdkXw/NE/i7WEpxb5E2uq3tIJfabPWWqAtg=; Received: from andrew by vps0.lunn.ch with local (Exim 4.92.2) (envelope-from ) id 1iXsSy-00023J-0u; Thu, 21 Nov 2019 20:50:12 +0100 Date: Thu, 21 Nov 2019 20:50:12 +0100 From: Andrew Lunn To: Ioana Ciornei Cc: davem@davemloft.net, netdev@vger.kernel.org, linux@armlinux.org.uk Subject: Re: [PATCH net-next 1/3] dpaa2-eth: do not hold rtnl_lock on phylink_create() or _destroy() Message-ID: <20191121195012.GA6602@lunn.ch> References: <1574363727-5437-1-git-send-email-ioana.ciornei@nxp.com> <1574363727-5437-2-git-send-email-ioana.ciornei@nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1574363727-5437-2-git-send-email-ioana.ciornei@nxp.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Nov 21, 2019 at 09:15:25PM +0200, Ioana Ciornei wrote: > The rtnl_lock should not be held when calling phylink_create() or > phylink_destroy() since it leads to the deadlock listed below: > > [ 18.656576] rtnl_lock+0x18/0x20 > [ 18.659798] sfp_bus_add_upstream+0x28/0x90 > [ 18.663974] phylink_create+0x2cc/0x828 > [ 18.667803] dpaa2_mac_connect+0x14c/0x2a8 > [ 18.671890] dpaa2_eth_connect_mac+0x94/0xd8 Hi Ioana Have you done any testing with CONFIG_PROVE_LOCKING enabled. It should find this sort of problem if the code paths get exercised. Andrew