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authorMatt Mackall <mpm@selenic.com>2005-08-11 19:27:43 -0700
committerDavid S. Miller <davem@davemloft.net>2005-08-11 19:27:43 -0700
commit53fb95d3c14290fd6ee808b221e35493f096246f (patch)
tree146c31c79bbc66d8fde3afa5ae37a04b63041eba /include/linux
parent2652076507b662fc88ba16c27b59c7bdd9ccd956 (diff)
[NETPOLL]: fix initialization/NAPI race
This fixes a race during initialization with the NAPI softirq processing by using an RCU approach. This race was discovered when refill_skbs() was added to the setup code. Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/netpoll.h19
1 files changed, 13 insertions, 6 deletions
diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h
index be68d94b03d..5ade54a78db 100644
--- a/include/linux/netpoll.h
+++ b/include/linux/netpoll.h
@@ -9,6 +9,7 @@
#include <linux/netdevice.h>
#include <linux/interrupt.h>
+#include <linux/rcupdate.h>
#include <linux/list.h>
struct netpoll;
@@ -61,25 +62,31 @@ static inline int netpoll_rx(struct sk_buff *skb)
return ret;
}
-static inline void netpoll_poll_lock(struct net_device *dev)
+static inline void *netpoll_poll_lock(struct net_device *dev)
{
+ rcu_read_lock(); /* deal with race on ->npinfo */
if (dev->npinfo) {
spin_lock(&dev->npinfo->poll_lock);
dev->npinfo->poll_owner = smp_processor_id();
+ return dev->npinfo;
}
+ return NULL;
}
-static inline void netpoll_poll_unlock(struct net_device *dev)
+static inline void netpoll_poll_unlock(void *have)
{
- if (dev->npinfo) {
- dev->npinfo->poll_owner = -1;
- spin_unlock(&dev->npinfo->poll_lock);
+ struct netpoll_info *npi = have;
+
+ if (npi) {
+ npi->poll_owner = -1;
+ spin_unlock(&npi->poll_lock);
}
+ rcu_read_unlock();
}
#else
#define netpoll_rx(a) 0
-#define netpoll_poll_lock(a)
+#define netpoll_poll_lock(a) 0
#define netpoll_poll_unlock(a)
#endif