From 8ceb59557bdc373e532b87d4142ce27e04218f0e Mon Sep 17 00:00:00 2001 From: Bob Copeland Date: Thu, 18 Apr 2013 18:26:49 -0400 Subject: [PATCH] mac80211: use synchronize_rcu() with rcu_barrier() The RCU docs used to state that rcu_barrier() included a wait for an RCU grace period; however the comments for rcu_barrier() as of commit f0a0e6f... "rcu: Clarify memory-ordering properties of grace-period primitives" contradict this. So add back synchronize_{rcu,net}() to where they once were, but keep the rcu_barrier()s for the call_rcu() callbacks. Cc: stable Signed-off-by: Bob Copeland Reviewed-by: Paul E. McKenney Signed-off-by: Johannes Berg --- net/mac80211/cfg.c | 1 + net/mac80211/iface.c | 5 +++-- net/mac80211/pm.c | 1 + 3 files changed, 5 insertions(+), 2 deletions(-) diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c index 490990e..1a89c80 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -1043,6 +1043,7 @@ static int ieee80211_stop_ap(struct wiphy *wiphy, struct net_device *dev) list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) sta_info_flush_defer(vlan); sta_info_flush_defer(sdata); + synchronize_net(); rcu_barrier(); list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) { sta_info_flush_cleanup(vlan); diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 146b132..9daa64e 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -839,11 +839,12 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata, * * sta_info_flush_cleanup() requires rcu_barrier() * first to wait for the station call_rcu() calls - * to complete, here we need at least sychronize_rcu() - * it to wait for the RX path in case it is using the + * to complete, and we also need synchronize_rcu() + * to wait for the RX path in case it is using the * interface and enqueuing frames at this very time on * another CPU. */ + synchronize_rcu(); rcu_barrier(); sta_info_flush_cleanup(sdata); diff --git a/net/mac80211/pm.c b/net/mac80211/pm.c index 4431f0f..7fc5d0d 100644 --- a/net/mac80211/pm.c +++ b/net/mac80211/pm.c @@ -38,6 +38,7 @@ int __ieee80211_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan) IEEE80211_QUEUE_STOP_REASON_SUSPEND); /* flush out all packets and station cleanup call_rcu()s */ + synchronize_net(); rcu_barrier(); ieee80211_flush_queues(local, NULL); -- 2.7.4