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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 CB5E6C43381 for ; Tue, 12 Mar 2019 17:42:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9DAC021734 for ; Tue, 12 Mar 2019 17:42:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552412557; bh=UY2kBkV2e9l/KGrFwczm1NkHnmte9s0hWgV8g+o2cBQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=2jFKO6Mxp/vTZXbLcdWYNgR+JPLByrVBJQGaiAvA8Zo7059NDCrwgvElPhchPShzf MG9fEwe3+YWcSp5lWJzHPCugDT47IyDZKu+6IuqV4qB4fy7AkJKv/TRRxCtdXcvfWk lhDl1kdHW8UAH4I3ZyLr1QzJWS+CnwqsvdnRdrpo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729185AbfCLRmg (ORCPT ); Tue, 12 Mar 2019 13:42:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:57216 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728923AbfCLRP4 (ORCPT ); Tue, 12 Mar 2019 13:15:56 -0400 Received: from localhost (unknown [104.133.8.98]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1BCE821850; Tue, 12 Mar 2019 17:15:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552410955; bh=UY2kBkV2e9l/KGrFwczm1NkHnmte9s0hWgV8g+o2cBQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QE+fnJuMMqqzZ9XiZOy9vtcc8TZlhRyzgGS6/mqKDzEy1G7IuDCQdf4hfKNUduIVG vmxOrAA0jtDLYtgJtyEtA8wKS7rHhEQn+jFY9haDs+9gzgBBwhJqLuHGLZQTRwscvv Gb5yEaGg8p5SkisK9c7PkgqF6uYaEQwUPJKpQ7Ks= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Igor Druzhinin , Paul Durrant , "David S. Miller" Subject: [PATCH 4.14 024/135] xen-netback: dont populate the hash cache on XenBus disconnect Date: Tue, 12 Mar 2019 10:07:51 -0700 Message-Id: <20190312170343.347675274@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190312170341.127810985@linuxfoundation.org> References: <20190312170341.127810985@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Igor Druzhinin [ Upstream commit a2288d4e355992d369c50c45d017a85f6061ff71 ] 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 Reviewed-by: Paul Durrant Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/xen-netback/hash.c | 2 ++ drivers/net/xen-netback/interface.c | 7 +++++++ 2 files changed, 9 insertions(+) --- a/drivers/net/xen-netback/hash.c +++ b/drivers/net/xen-netback/hash.c @@ -435,6 +435,8 @@ void xenvif_init_hash(struct xenvif *vif if (xenvif_hash_cache_size == 0) return; + BUG_ON(vif->hash.cache.count); + spin_lock_init(&vif->hash.cache.lock); INIT_LIST_HEAD(&vif->hash.cache.list); } --- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c @@ -153,6 +153,13 @@ static u16 xenvif_select_queue(struct ne { struct xenvif *vif = netdev_priv(dev); unsigned int size = vif->hash.size; + unsigned int num_queues; + + /* If queues are not set up internally - always return 0 + * as the packet going to be dropped anyway */ + num_queues = READ_ONCE(vif->num_queues); + if (num_queues < 1) + return 0; if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE) return fallback(dev, skb) % dev->real_num_tx_queues;