From f6b3d85f7f6d66f890862d763b2ed092c5dd4322 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Fri, 3 May 2013 10:01:03 +0200 Subject: mac80211: fix spurious RCU warning and update documentation Document rx vs tx status concurrency requirements. Signed-off-by: Felix Fietkau Signed-off-by: Johannes Berg --- net/mac80211/rate.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'net') diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c index 0d51877efdb..d3f414fe67e 100644 --- a/net/mac80211/rate.c +++ b/net/mac80211/rate.c @@ -688,8 +688,15 @@ int rate_control_set_rates(struct ieee80211_hw *hw, struct ieee80211_sta *pubsta, struct ieee80211_sta_rates *rates) { - struct ieee80211_sta_rates *old = rcu_dereference(pubsta->rates); + struct ieee80211_sta_rates *old; + /* + * mac80211 guarantees that this function will not be called + * concurrently, so the following RCU access is safe, even without + * extra locking. This can not be checked easily, so we just set + * the condition to true. + */ + old = rcu_dereference_protected(pubsta->rates, true); rcu_assign_pointer(pubsta->rates, rates); if (old) kfree_rcu(old, rcu_head); -- cgit v1.2.3-70-g09d2