From: Veaceslav Falico Date: Fri, 10 Jan 2014 10:59:45 +0000 (+0100) Subject: bonding: fix __get_active_agg() RCU logic X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=49b7624eda6867d2803bcc5bbf6f25936184304a;p=linux-beck.git bonding: fix __get_active_agg() RCU logic 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 RCU. 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 Signed-off-by: David S. Miller --- diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c index b49f421346a7..cce1f1bf90b4 100644 --- a/drivers/net/bonding/bond_3ad.c +++ b/drivers/net/bonding/bond_3ad.c @@ -678,6 +678,8 @@ 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 RCU lock. */ static struct aggregator *__get_active_agg(struct aggregator *aggregator) { @@ -685,13 +687,9 @@ 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(); + if (SLAVE_AD_INFO(slave).aggregator.is_active) return &(SLAVE_AD_INFO(slave).aggregator); - } - rcu_read_unlock(); return NULL; } @@ -1499,11 +1497,11 @@ 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);