commit: 8ceb59557bdc373e532b87d4142ce27e04218f0e
From: Bob Copeland <me@xxxxxxxxxxxxxxx>
Date: Thu, 18 Apr 2013 18:26:49 -0400
Subject: 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 <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Bob Copeland <bob@xxxxxxxxxxx>
Reviewed-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
---
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);
--
1.7.10.4
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