From patchwork Mon Mar 6 09:10:42 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Slaby X-Patchwork-Id: 94915 Delivered-To: patch@linaro.org Received: by 10.182.3.34 with SMTP id 2csp1247303obz; Mon, 6 Mar 2017 01:39:39 -0800 (PST) X-Received: by 10.98.72.199 with SMTP id q68mr19415028pfi.152.1488793179637; Mon, 06 Mar 2017 01:39:39 -0800 (PST) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id i35si15696282plg.308.2017.03.06.01.39.39; Mon, 06 Mar 2017 01:39:39 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of stable-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 stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753144AbdCFJj3 (ORCPT + 5 others); Mon, 6 Mar 2017 04:39:29 -0500 Received: from mx2.suse.de ([195.135.220.15]:37272 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752997AbdCFJMl (ORCPT ); Mon, 6 Mar 2017 04:12:41 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 563A7ADEE; Mon, 6 Mar 2017 09:12:35 +0000 (UTC) From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Kefeng Wang , "David S . Miller" , Jiri Slaby Subject: [PATCH 3.12 018/113] ipv6: addrconf: Avoid addrconf_disable_change() using RCU read-side lock Date: Mon, 6 Mar 2017 10:10:42 +0100 Message-Id: <1065fdb1dba37d36587ad22daa2e841e357eaf5f.1488791430.git.jslaby@suse.cz> X-Mailer: git-send-email 2.12.0 In-Reply-To: References: In-Reply-To: References: Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Kefeng Wang 3.12-stable review patch. If anyone has any objections, please let me know. -- 2.12.0 =============== [ Upstream commit 03e4deff4987f79c34112c5ba4eb195d4f9382b0 ] Just like commit 4acd4945cd1e ("ipv6: addrconf: Avoid calling netdevice notifiers with RCU read-side lock"), it is unnecessary to make addrconf_disable_change() use RCU iteration over the netdev list, since it already holds the RTNL lock, or we may meet Illegal context switch in RCU read-side critical section. Signed-off-by: Kefeng Wang Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby --- net/ipv6/addrconf.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 1e31fc5477e8..74fe3375aa7a 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -4693,8 +4693,7 @@ static void addrconf_disable_change(struct net *net, __s32 newf) struct net_device *dev; struct inet6_dev *idev; - rcu_read_lock(); - for_each_netdev_rcu(net, dev) { + for_each_netdev(net, dev) { idev = __in6_dev_get(dev); if (idev) { int changed = (!idev->cnf.disable_ipv6) ^ (!newf); @@ -4703,7 +4702,6 @@ static void addrconf_disable_change(struct net *net, __s32 newf) dev_disable_change(idev); } } - rcu_read_unlock(); } static int addrconf_disable_ipv6(struct ctl_table *table, int *p, int newf)