From 53fb95d3c14290fd6ee808b221e35493f096246f Mon Sep 17 00:00:00 2001 From: Matt Mackall Date: Thu, 11 Aug 2005 19:27:43 -0700 Subject: [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 Signed-off-by: David S. Miller --- include/linux/netpoll.h | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) (limited to 'include') 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 #include +#include #include 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 -- cgit v1.2.3-59-g8ed1b