Received: by 2002:ac0:8845:0:0:0:0:0 with SMTP id g63csp8090img; Thu, 28 Feb 2019 14:01:00 -0800 (PST) X-Google-Smtp-Source: APXvYqy/ehOqgLedzIkNKod7fk1Kc3+xqr8sf5bwF0Oi66U21nd+VXjj3aVBC55GJxccA1CVFsUw X-Received: by 2002:a17:902:585:: with SMTP id f5mr1717445plf.242.1551391260790; Thu, 28 Feb 2019 14:01:00 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1551391260; cv=none; d=google.com; s=arc-20160816; b=Afa4cDjm1DfzCKtyz2A3WI2dGxkzsEBRzSc0c81Vqgq4zdYxQORg4ITYdn5tUuls2H igQCMItD5mCt00L2ihMZejvrjtdHBaaGx2ngWkeQv4olRdFbZEHiegWSUjUDdqEAx0Uc uNaylaeggrqMllPtjFVmLxcQ17sAR3Kj7OIT611TCOsO/N2tAKNKR/UvjUV+hjMVNQbF ioiipyCghOSz8ktLU6mf4wfOg0edhJaKLVfSCLqEaKu/wwPdyieUjnh76IhcuL24zwFQ SFDh4nYxk1+qp2AUyMj5P8uT1/tmhTnWPhIIFCx7XJtVOchFZkn0s16TkglgbL3ZzfPJ 5njQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :references:in-reply-to:from:subject:cc:to:message-id:date; bh=SGhjTiBZN3iiGYz2vt+GFuHvpOaChizODGr3yDs687k=; b=mtUCMfwQqehqut3jjk78sqH7Jh8LUChObi1EMhho0I+gFNw17nDQJ662aF4n/VF5mk ze598wAG1YvSkpmbB+HjAFu+kttE5lCH80CxedFNoSNP+zyIkg69bWaqPb60oCiAlGkl wGZBoKFa/kPERMoKCWB4CHuzOjQd01c7EsHLSJHl5bYyfH0qzUnu1ZvW+rr+0zPQJW/W u9VuFis1J4Hf/NWe1Jv1Arc5MOLnThzRbC+mHiW5JpGMSIf5mxR/kCA9E+3ddtN74vCq HvlBbjyeGqYVlMQvxVkCw8qWHBYDIBvRQvvTbIgEZ8FPYOkVSKwundfUk5sN67VkWNmi 2kdA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id h127si20172662pfb.213.2019.02.28.14.00.44; Thu, 28 Feb 2019 14:01:00 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387408AbfB1UvP (ORCPT + 99 others); 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: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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.