From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH net-next-2.6] net: introduce rcu_dereference_rtnl Date: Wed, 08 Sep 2010 20:44:29 +0200 Message-ID: <1283971469.2428.9.camel@edumazet-laptop> References: <1283890291.2634.143.camel@edumazet-laptop> <4C86A558.6030802@gmail.com> <1283893657.2634.210.camel@edumazet-laptop> <1283970567.2237.0.camel@achroite.uk.solarflarecom.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Jarek Poplawski , David Miller , netdev To: Ben Hutchings Return-path: Received: from mail-fx0-f46.google.com ([209.85.161.46]:58952 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752122Ab0IHSoe (ORCPT ); Wed, 8 Sep 2010 14:44:34 -0400 Received: by fxm16 with SMTP id 16so344283fxm.19 for ; Wed, 08 Sep 2010 11:44:33 -0700 (PDT) In-Reply-To: <1283970567.2237.0.camel@achroite.uk.solarflarecom.com> Sender: netdev-owner@vger.kernel.org List-ID: Le mercredi 08 septembre 2010 =C3=A0 19:29 +0100, Ben Hutchings a =C3=A9= crit : > No semicolon on the end, please. The 'caller' will add that. Oh definitely, thanks ! [PATCH net-next-2.6] net: introduce rcu_dereference_rtnl We use rcu_dereference_check(p, rcu_read_lock_held() || lockdep_rtnl_is_held()) several times in network stack. More usages to come too, so its time to create a helper. Signed-off-by: Eric Dumazet --- include/linux/rtnetlink.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h index 58d4449..263690d 100644 --- a/include/linux/rtnetlink.h +++ b/include/linux/rtnetlink.h @@ -749,6 +749,17 @@ extern int rtnl_is_locked(void); extern int lockdep_rtnl_is_held(void); #endif /* #ifdef CONFIG_PROVE_LOCKING */ =20 +/** + * rcu_dereference_rtnl - rcu_dereference with debug checking + * @p: The pointer to read, prior to dereferencing + * + * Do an rcu_dereference(p), but check caller either holds rcu_read_lo= ck() + * or RTNL + */ +#define rcu_dereference_rtnl(p) \ + rcu_dereference_check(p, rcu_read_lock_held() || \ + lockdep_rtnl_is_held()) + extern void rtnetlink_init(void); extern void __rtnl_unlock(void); =20