This is a note to let you know that I've just added the patch titled
mac80211: fix station entry leak/warning while suspending
to the 3.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mac80211-fix-station-entry-leak-warning-while-suspending.patch
and it can be found in the queue-3.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b20d34c458bc2bbd0a4624f2933581e01e72d875 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@xxxxxxxxx>
Date: Wed, 17 Apr 2013 11:26:40 +0200
Subject: mac80211: fix station entry leak/warning while suspending
From: Johannes Berg <johannes.berg@xxxxxxxxx>
commit b20d34c458bc2bbd0a4624f2933581e01e72d875 upstream.
Since Stanislaw's patches, when suspending while connected,
cfg80211 will disconnect. This causes the AP station to be
removed, which uses call_rcu() to clean up. Due to needing
process context, this queues a work struct on the mac80211
workqueue. This will warn and fail when already suspended,
which can happen if the rcu call doesn't happen quickly.
To fix this, replace the synchronize_net() which is really
just synchronize_rcu_expedited() with rcu_barrier(), which
unlike synchronize_rcu() waits until RCU callback have run
and thus avoids this issue.
In theory, this can even happen without Stanislaw's change
to disconnect on suspend since userspace might disconnect
just before suspending, though then it's unlikely that the
call_rcu() will be delayed long enough.
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/mac80211/pm.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/net/mac80211/pm.c
+++ b/net/mac80211/pm.c
@@ -53,8 +53,8 @@ int __ieee80211_suspend(struct ieee80211
ieee80211_stop_queues_by_reason(hw,
IEEE80211_QUEUE_STOP_REASON_SUSPEND);
- /* flush out all packets */
- synchronize_net();
+ /* flush out all packets and station cleanup call_rcu()s */
+ rcu_barrier();
drv_flush(local, false);
Patches currently in stable-queue which might be from johannes.berg@xxxxxxxxx are
queue-3.9/iwlwifi-dvm-don-t-send-zeroed-lq-cmd.patch
queue-3.9/iwlwifi-fix-freeing-uninitialized-pointer.patch
queue-3.9/mac80211-use-synchronize_rcu-with-rcu_barrier.patch
queue-3.9/mac80211-fix-station-entry-leak-warning-while-suspending.patch
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