rcu: rcu_read_lock_bh_held(): disabling irqs also disables bh

rcu_dereference_bh() doesnt know yet about hard irq being disabled, so
lockdep can trigger in netpoll_rx() after commit f0f9deae9e (netpoll:
Disable IRQ around RCU dereference in netpoll_rx)

Reported-by: Miles Lane <miles.lane@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Tested-by: Miles Lane <miles.lane@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Eric Dumazet 2010-09-22 08:38:44 +02:00 committed by Paul E. McKenney
parent 27c379f7f8
commit b3a084b9b6

View File

@ -454,7 +454,7 @@ static inline notrace void rcu_read_unlock_sched_notrace(void)
* Makes rcu_dereference_check() do the dirty work.
*/
#define rcu_dereference_bh(p) \
rcu_dereference_check(p, rcu_read_lock_bh_held())
rcu_dereference_check(p, rcu_read_lock_bh_held() || irqs_disabled())
/**
* rcu_dereference_sched - fetch RCU-protected pointer, checking for RCU-sched