netfilter: add __rcu annotations

[linux-2.6-block.git] / net / netfilter / nf_queue.c

diff --git a/net/netfilter/nf_queue.c b/net/netfilter/nf_queue.c
index 74aebed5bd28bb5c0c924cec7d908615b82ffdd6..1876f74115618187521498ec5d91445569b3a623 100644 (file)
--- a/net/netfilter/nf_queue.c
+++ b/net/netfilter/nf_queue.c
@@ -27,14 +27,17 @@ static DEFINE_MUTEX(queue_handler_mutex);
 int nf_register_queue_handler(u_int8_t pf, const struct nf_queue_handler *qh)
 {
        int ret;
+       const struct nf_queue_handler *old;
 
        if (pf >= ARRAY_SIZE(queue_handler))
                return -EINVAL;
 
        mutex_lock(&queue_handler_mutex);
-       if (queue_handler[pf] == qh)
+       old = rcu_dereference_protected(queue_handler[pf],
+                                       lockdep_is_held(&queue_handler_mutex));
+       if (old == qh)
                ret = -EEXIST;
-       else if (queue_handler[pf])
+       else if (old)
                ret = -EBUSY;
        else {
                rcu_assign_pointer(queue_handler[pf], qh);
@@ -49,11 +52,15 @@ EXPORT_SYMBOL(nf_register_queue_handler);
 /* The caller must flush their queue before this */
 int nf_unregister_queue_handler(u_int8_t pf, const struct nf_queue_handler *qh)
 {
+       const struct nf_queue_handler *old;
+
        if (pf >= ARRAY_SIZE(queue_handler))
                return -EINVAL;
 
        mutex_lock(&queue_handler_mutex);
-       if (queue_handler[pf] && queue_handler[pf] != qh) {
+       old = rcu_dereference_protected(queue_handler[pf],
+                                       lockdep_is_held(&queue_handler_mutex));
+       if (old && old != qh) {
                mutex_unlock(&queue_handler_mutex);
                return -EINVAL;
        }
@@ -73,7 +80,10 @@ void nf_unregister_queue_handlers(const struct nf_queue_handler *qh)
 
        mutex_lock(&queue_handler_mutex);
        for (pf = 0; pf < ARRAY_SIZE(queue_handler); pf++)  {
-               if (queue_handler[pf] == qh)
+               if (rcu_dereference_protected(
+                               queue_handler[pf],
+                               lockdep_is_held(&queue_handler_mutex)
+                               ) == qh)
                        rcu_assign_pointer(queue_handler[pf], NULL);
        }
        mutex_unlock(&queue_handler_mutex);