From: Ron Rindjunsky <ron.rindjunsky@xxxxxxxxx>
This patch fixes a deadlock of sta->lock use, occuring while changing
tx aggregation states, as dev_queue_xmit end up in new function
test_and_clear_sta_flags that uses that lock thus leading to deadlock
Signed-off-by: Ron Rindjunsky <ron.rindjunsky@xxxxxxxxx>
Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
---
net/mac80211/main.c | 10 +++++++---
1 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index b0fddb7..5a9030c 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -662,6 +662,8 @@ int ieee80211_start_tx_ba_session(struct ieee80211_hw *hw, u8 *ra, u16 tid)
goto start_ba_err;
}
+ spin_unlock_bh(&sta->lock);
+
/* Will put all the packets in the new SW queue */
ieee80211_requeue(local, ieee802_1d_to_ac[tid]);
spin_unlock_bh(&local->mdev->queue_lock);
@@ -688,9 +690,9 @@ start_ba_err:
kfree(sta->ampdu_mlme.tid_tx[tid]);
sta->ampdu_mlme.tid_tx[tid] = NULL;
spin_unlock_bh(&local->mdev->queue_lock);
+ spin_unlock_bh(&sta->lock);
ret = -EBUSY;
start_ba_exit:
- spin_unlock_bh(&sta->lock);
rcu_read_unlock();
return ret;
}
@@ -829,10 +831,11 @@ void ieee80211_stop_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u8 tid)
}
state = &sta->ampdu_mlme.tid_state_tx[tid];
- spin_lock_bh(&sta->lock);
+ /* no need to use sta->lock in this state check, as
+ * ieee80211_stop_tx_ba_session will let only
+ * one stop call to pass through per sta/tid */
if ((*state & HT_AGG_STATE_REQ_STOP_BA_MSK) == 0) {
printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
- spin_unlock_bh(&sta->lock);
rcu_read_unlock();
return;
}
@@ -855,6 +858,7 @@ void ieee80211_stop_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u8 tid)
* ieee80211_wake_queue is not used here as this queue is not
* necessarily stopped */
netif_schedule(local->mdev);
+ spin_lock_bh(&sta->lock);
*state = HT_AGG_STATE_IDLE;
sta->ampdu_mlme.addba_req_num[tid] = 0;
kfree(sta->ampdu_mlme.tid_tx[tid]);
--
1.5.4.1
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