From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758183AbaHZNqo (ORCPT ); Tue, 26 Aug 2014 09:46:44 -0400 Received: from mail-lb0-f179.google.com ([209.85.217.179]:32812 "EHLO mail-lb0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755163AbaHZNqm (ORCPT ); Tue, 26 Aug 2014 09:46:42 -0400 Date: Tue, 26 Aug 2014 16:46:32 +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: sit: Replace rcu_assign_pointer() with RCU_INIT_POINTER() Message-ID: <20140826134632.GA1473@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/sit.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c index 4f40817..24c2dba 100644 --- a/net/ipv6/sit.c +++ b/net/ipv6/sit.c @@ -167,7 +167,7 @@ static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t) { struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t); - rcu_assign_pointer(t->next, rtnl_dereference(*tp)); + RCU_INIT_POINTER(t->next, rtnl_dereference(*tp)); rcu_assign_pointer(*tp, t); } -- 1.9.1