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| author | Veaceslav Falico <vfalico@redhat.com> | 2014-01-10 11:59:44 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-01-13 22:22:27 -0800 |
| commit | 768b954922e69a92a363bd4041cb93040ae4e9cf (patch) | |
| tree | a6de632160b5525aaebc9e462a7790c1b41d932f /drivers/net/bonding/bond_3ad.c | |
| parent | c1bc9644ecd1f663f918d42b33b41a508683b0ee (diff) | |
| download | lwn-768b954922e69a92a363bd4041cb93040ae4e9cf.tar.gz lwn-768b954922e69a92a363bd4041cb93040ae4e9cf.zip | |
bonding: fix __get_first_agg RCU usage
Currently, the RCU read lock usage is just wrong - it gets the slave struct
under RCU and continues to use it when RCU lock is released.
However, it's still safe to do this cause we didn't need the
rcu_read_lock() initially - all of the __get_first_agg() callers are either
holding RCU read lock or the RTNL lock, so that we can't sync while in it.
Fixes: be79bd048 ("bonding: add RCU for bond_3ad_state_machine_handler()")
CC: dingtianhong@huawei.com
CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/bonding/bond_3ad.c')
| -rw-r--r-- | drivers/net/bonding/bond_3ad.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c index da0d7c54d352..b49f421346a7 100644 --- a/drivers/net/bonding/bond_3ad.c +++ b/drivers/net/bonding/bond_3ad.c @@ -143,11 +143,13 @@ static inline struct bonding *__get_bond_by_port(struct port *port) * * Return the aggregator of the first slave in @bond, or %NULL if it can't be * found. + * The caller must hold RCU or RTNL lock. */ static inline struct aggregator *__get_first_agg(struct port *port) { struct bonding *bond = __get_bond_by_port(port); struct slave *first_slave; + struct aggregator *agg; /* If there's no bond for this port, or bond has no slaves */ if (bond == NULL) @@ -155,9 +157,10 @@ static inline struct aggregator *__get_first_agg(struct port *port) rcu_read_lock(); first_slave = bond_first_slave_rcu(bond); + agg = first_slave ? &(SLAVE_AD_INFO(first_slave).aggregator) : NULL; rcu_read_unlock(); - return first_slave ? &(SLAVE_AD_INFO(first_slave).aggregator) : NULL; + return agg; } /** |