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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 07C26C43381 for ; Thu, 28 Feb 2019 20:51:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D2B712084F for ; Thu, 28 Feb 2019 20:51:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733243AbfB1UvP (ORCPT ); Thu, 28 Feb 2019 15:51:15 -0500 Received: from shards.monkeyblade.net ([23.128.96.9]:38618 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726172AbfB1UvP (ORCPT ); Thu, 28 Feb 2019 15:51:15 -0500 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::bf5]) (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 B17E914BFC366; Thu, 28 Feb 2019 12:51:14 -0800 (PST) Date: Thu, 28 Feb 2019 12:51:14 -0800 (PST) Message-Id: <20190228.125114.10822000460043710.davem@davemloft.net> To: igor.druzhinin@citrix.com Cc: xen-devel@lists.xenproject.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, wei.liu2@citrix.com, paul.durrant@citrix.com Subject: Re: [PATCH] xen-netback: don't populate the hash cache on XenBus disconnect From: David Miller In-Reply-To: <1551363086-29652-1-git-send-email-igor.druzhinin@citrix.com> References: <1551363086-29652-1-git-send-email-igor.druzhinin@citrix.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]); Thu, 28 Feb 2019 12:51:14 -0800 (PST) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Igor Druzhinin Date: Thu, 28 Feb 2019 14:11:26 +0000 > Occasionally, during the disconnection procedure on XenBus which > includes hash cache deinitialization there might be some packets > still in-flight on other processors. Handling of these packets includes > hashing and hash cache population that finally results in hash cache > data structure corruption. > > In order to avoid this we prevent hashing of those packets if there > are no queues initialized. In that case RCU protection of queues guards > the hash cache as well. > > Signed-off-by: Igor Druzhinin Applied and queued up for -stable, thanks.