From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758344AbaHZOFz (ORCPT ); Tue, 26 Aug 2014 10:05:55 -0400 Received: from mail-la0-f41.google.com ([209.85.215.41]:41682 "EHLO mail-la0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758324AbaHZOFy (ORCPT ); Tue, 26 Aug 2014 10:05:54 -0400 Date: Tue, 26 Aug 2014 17:05:43 +0300 From: Andreea-Cristina Bernat To: davem@davemloft.net, kuznet@ms2.inr.ac.ru, jmorris@namei.org, yoshfuji@linux-ipv6.org, kaber@trash.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: paulmck@linux.vnet.ibm.com Subject: [PATCH] ipv6: ip6_tunnel: Replace rcu_assign_pointer() with RCU_INIT_POINTER() Message-ID: <20140826140543.GA1846@ada> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org According to RCU_INIT_POINTER()'s block comment 3.a, it can be used if "3. The referenced data structure has already been exposed to readers either at compile time or via rcu_assign_pointer() -and- a. You have not made -any- reader-visible changes to this structure since then". This case fulfills the conditions above because between the rtnl_dereference() call and the rcu_assign_pointer() call there is no update of that value. Therefore, this patch makes the replacement. The following Coccinelle semantic patch was used: @@ @@ - rcu_assign_pointer + RCU_INIT_POINTER (..., ( rtnl_dereference(...) | rcu_dereference_protected(...) ) ) Signed-off-by: Andreea-Cristina Bernat --- net/ipv6/ip6_tunnel.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index afa0824..3837be3 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -233,7 +233,7 @@ ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t) { struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms); - rcu_assign_pointer(t->next , rtnl_dereference(*tp)); + RCU_INIT_POINTER(t->next , rtnl_dereference(*tp)); rcu_assign_pointer(*tp, t); } -- 1.9.1