diff options
| author | Matt Mackall <mpm@selenic.com> | 2005-08-11 19:27:43 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2005-08-11 19:27:43 -0700 |
| commit | 53fb95d3c14290fd6ee808b221e35493f096246f (patch) | |
| tree | 146c31c79bbc66d8fde3afa5ae37a04b63041eba /include/linux/netpoll.h | |
| parent | 2652076507b662fc88ba16c27b59c7bdd9ccd956 (diff) | |
| download | lwn-53fb95d3c14290fd6ee808b221e35493f096246f.tar.gz lwn-53fb95d3c14290fd6ee808b221e35493f096246f.zip | |
[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/netpoll.h')
| -rw-r--r-- | include/linux/netpoll.h | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h index be68d94b03d5..5ade54a78dbb 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 |