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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2010-02-22 17:04:49 -0800
committerIngo Molnar <mingo@elte.hu>2010-02-25 09:41:03 +0100
commita898def29e4119bc01ebe7ca97423181f4c0ea2d (patch)
treee6f89d4f4a91fd24507ad600ebb9ad620ec9d9a8 /net/core/sock.c
parent3120438ad68601f341e61e7cb1323b0e1a6ca367 (diff)
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 <eric.dumazet@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> 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 <mingo@elte.hu>
Diffstat (limited to 'net/core/sock.c')
-rw-r--r--net/core/sock.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/core/sock.c b/net/core/sock.c
index e1f6f225f01..305cba401ae 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1073,7 +1073,8 @@ static void __sk_free(struct sock *sk)
if (sk->sk_destruct)
sk->sk_destruct(sk);
- filter = rcu_dereference(sk->sk_filter);
+ filter = rcu_dereference_check(sk->sk_filter,
+ atomic_read(&sk->sk_wmem_alloc) == 0);
if (filter) {
sk_filter_uncharge(sk, filter);
rcu_assign_pointer(sk->sk_filter, NULL);