aboutsummaryrefslogtreecommitdiffstats
path: root/include
diff options
context:
space:
mode:
authorHerbert Xu <herbert@gondor.apana.org.au>2010-09-17 16:55:03 -0700
committerDavid S. Miller <davem@davemloft.net>2010-09-17 16:55:03 -0700
commitf0f9deae9e7c421fa0c1c627beb8e174325e1ba7 (patch)
tree7883b0c64cc16f1c3f3f4360a4dbcc214e6a6a22 /include
parent4bdab43323b459900578b200a4b8cf9713ac8fab (diff)
downloadmrst-s0i3-test-f0f9deae9e7c421fa0c1c627beb8e174325e1ba7.tar.gz
mrst-s0i3-test-f0f9deae9e7c421fa0c1c627beb8e174325e1ba7.tar.xz
mrst-s0i3-test-f0f9deae9e7c421fa0c1c627beb8e174325e1ba7.zip
netpoll: Disable IRQ around RCU dereference in netpoll_rx
We cannot use rcu_dereference_bh safely in netpoll_rx as we may be called with IRQs disabled. We could however simply disable IRQs as that too causes BH to be disabled and is safe in either case. Thanks to John Linville for discovering this bug and providing a patch. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
-rw-r--r--include/linux/netpoll.h8
1 files changed, 4 insertions, 4 deletions
diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h
index 791d5109f34..50d8009be86 100644
--- a/include/linux/netpoll.h
+++ b/include/linux/netpoll.h
@@ -63,20 +63,20 @@ static inline bool netpoll_rx(struct sk_buff *skb)
unsigned long flags;
bool ret = false;
- rcu_read_lock_bh();
+ local_irq_save(flags);
npinfo = rcu_dereference_bh(skb->dev->npinfo);
if (!npinfo || (list_empty(&npinfo->rx_np) && !npinfo->rx_flags))
goto out;
- spin_lock_irqsave(&npinfo->rx_lock, flags);
+ spin_lock(&npinfo->rx_lock);
/* check rx_flags again with the lock held */
if (npinfo->rx_flags && __netpoll_rx(skb))
ret = true;
- spin_unlock_irqrestore(&npinfo->rx_lock, flags);
+ spin_unlock(&npinfo->rx_lock);
out:
- rcu_read_unlock_bh();
+ local_irq_restore(flags);
return ret;
}