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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 A3548C3A59E for ; Mon, 26 Aug 2019 05:59:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7598121848 for ; Mon, 26 Aug 2019 05:59:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729317AbfHZF76 (ORCPT ); Mon, 26 Aug 2019 01:59:58 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:58818 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726606AbfHZF76 (ORCPT ); Mon, 26 Aug 2019 01:59:58 -0400 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::d71]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id A417E15248637; Sun, 25 Aug 2019 22:59:57 -0700 (PDT) Date: Sun, 25 Aug 2019 22:59:57 -0700 (PDT) Message-Id: <20190825.225957.2229146461648644754.davem@davemloft.net> To: michael.chan@broadcom.com Cc: netdev@vger.kernel.org, vasundhara-v.volam@broadcom.com, jiri@mellanox.com, ray.jui@broadcom.com Subject: Re: [PATCH net-next 08/14] bnxt_en: Add BNXT_STATE_IN_FW_RESET state and pf->registered_vfs. From: David Miller In-Reply-To: <1566791705-20473-9-git-send-email-michael.chan@broadcom.com> References: <1566791705-20473-1-git-send-email-michael.chan@broadcom.com> <1566791705-20473-9-git-send-email-michael.chan@broadcom.com> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Sun, 25 Aug 2019 22:59:57 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Michael Chan Date: Sun, 25 Aug 2019 23:54:59 -0400 > @@ -9234,6 +9243,13 @@ int bnxt_close_nic(struct bnxt *bp, bool irq_re_init, bool link_re_init) > { > int rc = 0; > > + while (test_bit(BNXT_STATE_IN_FW_RESET, &bp->state)) { > + netdev_info(bp->dev, "FW reset in progress, delaying close"); > + rtnl_unlock(); > + msleep(250); > + rtnl_lock(); > + } Dropping the RTNL here is extremely dangerous. Operations other than actual device close can get into the bnxt_close_nic() code paths (changing features, ethtool ops, etc.) So we can thus re-enter this function once you drop the RTNL mutex. Furthermore, and I understand what pains you go into in patch #9 to avoid this, but it's an endless loop. If there are bugs there, we will get stuck in this close path forever.