From 0379185b6c0d1e8252023698cf1091da92a3dc03 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 6 Apr 2010 11:18:42 +0200 Subject: [PATCH 1/1] mac80211: annotate station rcu dereferences The new RCU lockdep support warns about these in some contexts -- make it aware of the locks used to protect all this. Different locks are used in different contexts which unfortunately means we can't get perfect checking. Also remove rcu_dereference() from two places that don't actually dereference the pointers. Signed-off-by: Johannes Berg Signed-off-by: John W. Linville --- net/mac80211/main.c | 4 ++-- net/mac80211/sta_info.c | 20 ++++++++++++++++---- 2 files changed, 18 insertions(+), 6 deletions(-) diff --git a/net/mac80211/main.c b/net/mac80211/main.c index 06c33b6..b887e48 100644 --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -225,11 +225,11 @@ void ieee80211_bss_info_change_notify(struct ieee80211_sub_if_data *sdata, switch (sdata->vif.type) { case NL80211_IFTYPE_AP: sdata->vif.bss_conf.enable_beacon = - !!rcu_dereference(sdata->u.ap.beacon); + !!sdata->u.ap.beacon; break; case NL80211_IFTYPE_ADHOC: sdata->vif.bss_conf.enable_beacon = - !!rcu_dereference(sdata->u.ibss.presp); + !!sdata->u.ibss.presp; break; case NL80211_IFTYPE_MESH_POINT: sdata->vif.bss_conf.enable_beacon = true; diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c index 56422d8..fb12cec 100644 --- a/net/mac80211/sta_info.c +++ b/net/mac80211/sta_info.c @@ -93,12 +93,18 @@ struct sta_info *sta_info_get(struct ieee80211_sub_if_data *sdata, struct ieee80211_local *local = sdata->local; struct sta_info *sta; - sta = rcu_dereference(local->sta_hash[STA_HASH(addr)]); + sta = rcu_dereference_check(local->sta_hash[STA_HASH(addr)], + rcu_read_lock_held() || + lockdep_is_held(&local->sta_lock) || + lockdep_is_held(&local->sta_mtx)); while (sta) { if (sta->sdata == sdata && memcmp(sta->sta.addr, addr, ETH_ALEN) == 0) break; - sta = rcu_dereference(sta->hnext); + sta = rcu_dereference_check(sta->hnext, + rcu_read_lock_held() || + lockdep_is_held(&local->sta_lock) || + lockdep_is_held(&local->sta_mtx)); } return sta; } @@ -113,13 +119,19 @@ struct sta_info *sta_info_get_bss(struct ieee80211_sub_if_data *sdata, struct ieee80211_local *local = sdata->local; struct sta_info *sta; - sta = rcu_dereference(local->sta_hash[STA_HASH(addr)]); + sta = rcu_dereference_check(local->sta_hash[STA_HASH(addr)], + rcu_read_lock_held() || + lockdep_is_held(&local->sta_lock) || + lockdep_is_held(&local->sta_mtx)); while (sta) { if ((sta->sdata == sdata || sta->sdata->bss == sdata->bss) && memcmp(sta->sta.addr, addr, ETH_ALEN) == 0) break; - sta = rcu_dereference(sta->hnext); + sta = rcu_dereference_check(sta->hnext, + rcu_read_lock_held() || + lockdep_is_held(&local->sta_lock) || + lockdep_is_held(&local->sta_mtx)); } return sta; } -- 1.8.2.3