From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-ia0-f175.google.com ([209.85.210.175]:64147 "EHLO mail-ia0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752689Ab3DRW1V (ORCPT ); Thu, 18 Apr 2013 18:27:21 -0400 Received: by mail-ia0-f175.google.com with SMTP id e16so2929929iaa.34 for ; Thu, 18 Apr 2013 15:27:20 -0700 (PDT) Date: Thu, 18 Apr 2013 18:26:49 -0400 From: Bob Copeland To: johannes@sipsolutions.net Cc: linux-wireless@vger.kernel.org, paulmck@linux.vnet.ibm.com Subject: [PATCH v2] mac80211: use synchronize_rcu() with rcu_barrier() Message-ID: <20130418222649.GC3759@localhost> (sfid-20130419_002724_768379_B1251428) References: <20130418220443.GB3759@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20130418220443.GB3759@localhost> Sender: linux-wireless-owner@vger.kernel.org List-ID: 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 --- v2: also in cfg.c 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 72ab1c0..dcffca4 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 b6abaaa..c634aff 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -836,11 +836,12 @@ 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