Re: [PATCH v3] netpoll: protect napi_poll and poll_controller during dev_[open|close]
From: Francois Romieu <romieu@fr.zoreil.com>
Date: 2013-02-01 21:53:04
Neil Horman [off-list ref] : [...]
quoted hunk ↗ jump to hunk
diff --git a/net/core/dev.c b/net/core/dev.c index a87bc74..90b267a 100644 --- a/net/core/dev.c +++ b/net/core/dev.c
[...]
quoted hunk ↗ jump to hunk
@@ -1266,6 +1268,19 @@ static int __dev_open(struct net_device *dev) if (!netif_device_present(dev)) return -ENODEV; + /* + * Block netpoll from trying to do any rx path servicing + * If we don't do this there is a chance ndo_poll_controller + * or ndo_poll may be running while we open the device + */ + rcu_read_lock(); + ni = rcu_dereference(dev->npinfo); + if (ni && test_and_set_bit(NETPOLL_RX_ACTIVE, &ni->flags)) { + rcu_read_unlock(); + return -EBUSY; + } + rcu_read_unlock(); +
struct net_device contains no npinfo member when CONFIG_NETPOLL is not set. -- Ueimor