From a898def29e4119bc01ebe7ca97423181f4c0ea2d Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 22 Feb 2010 17:04:49 -0800 Subject: net: Add checking to rcu_dereference() primitives Update rcu_dereference() primitives to use new lockdep-based checking. The rcu_dereference() in __in6_dev_get() may be protected either by rcu_read_lock() or RTNL, per Eric Dumazet. The rcu_dereference() in __sk_free() is protected by the fact that it is never reached if an update could change it. Check for this by using rcu_dereference_check() to verify that the struct sock's ->sk_wmem_alloc counter is zero. Acked-by: Eric Dumazet Acked-by: David S. Miller Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1266887105-1528-5-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar --- net/core/rtnetlink.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'net/core/rtnetlink.c') diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 794bcb897ff..4c7d3f635ba 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -89,6 +89,14 @@ int rtnl_is_locked(void) } EXPORT_SYMBOL(rtnl_is_locked); +#ifdef CONFIG_PROVE_LOCKING +int lockdep_rtnl_is_held(void) +{ + return lockdep_is_held(&rtnl_mutex); +} +EXPORT_SYMBOL(lockdep_rtnl_is_held); +#endif /* #ifdef CONFIG_PROVE_LOCKING */ + static struct rtnl_link *rtnl_msg_handlers[NPROTO]; static inline int rtm_msgindex(int msgtype) -- cgit v1.2.3-70-g09d2