From mboxrd@z Thu Jan 1 00:00:00 1970 From: Veaceslav Falico Subject: [PATCH v2 net-next 3/3] bonding: fix __get_active_agg() RCU logic Date: Thu, 9 Jan 2014 12:20:25 +0100 Message-ID: <1389266425-28365-4-git-send-email-vfalico@redhat.com> References: <1389266425-28365-1-git-send-email-vfalico@redhat.com> Cc: Veaceslav Falico , dingtianhong@huawei.com, Jay Vosburgh , Andy Gospodarek To: netdev@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:36645 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753152AbaAILYs (ORCPT ); Thu, 9 Jan 2014 06:24:48 -0500 In-Reply-To: <1389266425-28365-1-git-send-email-vfalico@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: Currently, the implementation is meaningless - once again, we take the slave structure and use it after we've exited RCU critical section. Fix this by removing the rcu_read_lock() from __get_active_agg(), and ensuring that all its callers are holding either RCU or RTNL lock. Fixes: be79bd048 ("bonding: add RCU for bond_3ad_state_machine_handler()") CC: dingtianhong@huawei.com CC: Jay Vosburgh CC: Andy Gospodarek Signed-off-by: Veaceslav Falico --- Notes: v1 -> v2: Don't use RCU primitives as we can hold RTNL. drivers/net/bonding/bond_3ad.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c index d2782c8..845545b 100644 --- a/drivers/net/bonding/bond_3ad.c +++ b/drivers/net/bonding/bond_3ad.c @@ -674,6 +674,8 @@ static u32 __get_agg_bandwidth(struct aggregator *aggregator) /** * __get_active_agg - get the current active aggregator * @aggregator: the aggregator we're looking at + * + * Caller must hold either RCU or RTNL lock. */ static struct aggregator *__get_active_agg(struct aggregator *aggregator) { @@ -681,13 +683,9 @@ static struct aggregator *__get_active_agg(struct aggregator *aggregator) struct list_head *iter; struct slave *slave; - rcu_read_lock(); - bond_for_each_slave_rcu(bond, slave, iter) - if (SLAVE_AD_INFO(slave).aggregator.is_active) { - rcu_read_unlock(); + bond_for_each_slave(bond, slave, iter) + if (SLAVE_AD_INFO(slave).aggregator.is_active) return &(SLAVE_AD_INFO(slave).aggregator); - } - rcu_read_unlock(); return NULL; } @@ -1495,11 +1493,11 @@ static void ad_agg_selection_logic(struct aggregator *agg) struct slave *slave; struct port *port; + rcu_read_lock(); origin = agg; active = __get_active_agg(agg); best = (active && agg_device_up(active)) ? active : NULL; - rcu_read_lock(); bond_for_each_slave_rcu(bond, slave, iter) { agg = &(SLAVE_AD_INFO(slave).aggregator); -- 1.8.4