Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753162AbdCFJj5 (ORCPT ); Mon, 6 Mar 2017 04:39:57 -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-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" 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: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1465 Lines: 45 From: Kefeng Wang 3.12-stable review patch. If anyone has any objections, please let me know. =============== [ 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) -- 2.12.0