mac80211: sparse RCU annotations

This adds sparse RCU annotations to most of
mac80211, only the mesh code remains to be
done.

Due the the previous patches, the annotations
are pretty simple. The only thing that this
actually changes is removing the RCU usage of
key->sta in debugfs since this pointer isn't
actually an RCU-managed pointer (it only has
a single assignment done before the key even
goes live). As that is otherwise harmless, I
decided to make it part of this patch.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 9 insertions, 6 deletions

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index cba8309e9ac..82ab6b4643f 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -67,7 +67,8 @@ static int sta_info_hash_del(struct ieee80211_local *local,
 {
 	struct sta_info *s;
 
-	s = local->sta_hash[STA_HASH(sta->sta.addr)];
+	s = rcu_dereference_protected(local->sta_hash[STA_HASH(sta->sta.addr)],
+				      lockdep_is_held(&local->sta_lock));
 	if (!s)
 		return -ENOENT;
 	if (s == sta) {
@@ -76,9 +77,11 @@ static int sta_info_hash_del(struct ieee80211_local *local,
 		return 0;
 	}
 
-	while (s->hnext && s->hnext != sta)
-		s = s->hnext;
-	if (s->hnext) {
+	while (rcu_access_pointer(s->hnext) &&
+	       rcu_access_pointer(s->hnext) != sta)
+		s = rcu_dereference_protected(s->hnext,
+					lockdep_is_held(&local->sta_lock));
+	if (rcu_access_pointer(s->hnext)) {
 		rcu_assign_pointer(s->hnext, sta->hnext);
 		return 0;
 	}
@@ -654,9 +657,9 @@ static int __must_check __sta_info_destroy(struct sta_info *sta)
 
 	mutex_lock(&local->key_mtx);
 	for (i = 0; i < NUM_DEFAULT_KEYS; i++)
-		__ieee80211_key_free(sta->gtk[i]);
+		__ieee80211_key_free(key_mtx_dereference(local, sta->gtk[i]));
 	if (sta->ptk)
-		__ieee80211_key_free(sta->ptk);
+		__ieee80211_key_free(key_mtx_dereference(local, sta->ptk));
 	mutex_unlock(&local->key_mtx);
 
 	sta->dead = true;