3.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Bob Copeland <[email protected]> commit 8ceb59557bdc373e532b87d4142ce27e04218f0e upstream. 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. Signed-off-by: Bob Copeland <[email protected]> Reviewed-by: Paul E. McKenney <[email protected]> Signed-off-by: Johannes Berg <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- net/mac80211/cfg.c | 1 + net/mac80211/iface.c | 5 +++-- net/mac80211/pm.c | 1 + 3 files changed, 5 insertions(+), 2 deletions(-) --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -1034,6 +1034,7 @@ static int ieee80211_stop_ap(struct wiph 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); --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -844,11 +844,12 @@ static void ieee80211_do_stop(struct iee * * 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); --- a/net/mac80211/pm.c +++ b/net/mac80211/pm.c @@ -54,6 +54,7 @@ int __ieee80211_suspend(struct ieee80211 IEEE80211_QUEUE_STOP_REASON_SUSPEND); /* flush out all packets and station cleanup call_rcu()s */ + synchronize_net(); rcu_barrier(); drv_flush(local, false); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
