commit 875e94392ad2be9776c8325d3573160eb1455a2b
author Maya Erez <qca_merez@qca.qualcomm.com> Thu Jan 28 19:24:02 2016 +0200
committer Kalle Valo <kvalo@qca.qualcomm.com> Tue Feb 02 14:05:56 2016 +0200
tree 43b7a57a8847b70b2d3703dcacb74befccc6d72b
parent 1286558e45fd90fd0faf5d41df35f511c51f25e7

wil6210: prevent access to vring_tx_data lock during its init

wil_tx_vring locks the vring_tx_data lock before accessing the TX
vring to check if it is enabled and valid for use.
In case of quick disconnect / connect events for the same station,
spin_lock(&txdata->lock) can be called during the lock initialization
in the vring init function.
To prevent such a race, the TX vrings spin lock should be initialized
once during wil6210 driver initialization.

Signed-off-by: Maya Erez <qca_merez@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/wil6210/main.c

diff --git a/drivers/net/wireless/ath/wil6210/main.c b/drivers/net/wireless/ath/wil6210/main.c
index 0652efe..712ebbf 100644
--- a/drivers/net/wireless/ath/wil6210/main.c
+++ b/drivers/net/wireless/ath/wil6210/main.c
@@ -438,6 +438,9 @@
 	for (i = 0; i < WIL6210_MAX_CID; i++)
 		spin_lock_init(&wil->sta[i].tid_rx_lock);
 
+	for (i = 0; i < WIL6210_MAX_TX_RINGS; i++)
+		spin_lock_init(&wil->vring_tx_data[i].lock);
+
 	mutex_init(&wil->mutex);
 	mutex_init(&wil->wmi_mutex);
 	mutex_init(&wil->back_rx_mutex);

drivers/net/wireless/ath/wil6210/txrx.c

diff --git a/drivers/net/wireless/ath/wil6210/txrx.c b/drivers/net/wireless/ath/wil6210/txrx.c
index 9680b97..6af2090 100644
--- a/drivers/net/wireless/ath/wil6210/txrx.c
+++ b/drivers/net/wireless/ath/wil6210/txrx.c
@@ -717,6 +717,21 @@
 		wil_vring_free(wil, vring, 0);
 }
 
+static inline void wil_tx_data_init(struct vring_tx_data *txdata)
+{
+	spin_lock_bh(&txdata->lock);
+	txdata->dot1x_open = 0;
+	txdata->enabled = 0;
+	txdata->idle = 0;
+	txdata->last_idle = 0;
+	txdata->begin = 0;
+	txdata->agg_wsize = 0;
+	txdata->agg_timeout = 0;
+	txdata->agg_amsdu = 0;
+	txdata->addba_in_progress = false;
+	spin_unlock_bh(&txdata->lock);
+}
+
 int wil_vring_init_tx(struct wil6210_priv *wil, int id, int size,
 		      int cid, int tid)
 {
@@ -758,8 +773,7 @@
 		goto out;
 	}
 
-	memset(txdata, 0, sizeof(*txdata));
-	spin_lock_init(&txdata->lock);
+	wil_tx_data_init(txdata);
 	vring->size = size;
 	rc = wil_vring_alloc(wil, vring);
 	if (rc)
@@ -791,8 +805,10 @@
 
 	return 0;
  out_free:
+	spin_lock_bh(&txdata->lock);
 	txdata->dot1x_open = false;
 	txdata->enabled = 0;
+	spin_unlock_bh(&txdata->lock);
 	wil_vring_free(wil, vring, 1);
 	wil->vring2cid_tid[id][0] = WIL6210_MAX_CID;
 	wil->vring2cid_tid[id][1] = 0;
@@ -834,8 +850,7 @@
 		goto out;
 	}
 
-	memset(txdata, 0, sizeof(*txdata));
-	spin_lock_init(&txdata->lock);
+	wil_tx_data_init(txdata);
 	vring->size = size;
 	rc = wil_vring_alloc(wil, vring);
 	if (rc)
@@ -865,8 +880,10 @@
 
 	return 0;
  out_free:
+	spin_lock_bh(&txdata->lock);
 	txdata->enabled = 0;
 	txdata->dot1x_open = false;
+	spin_unlock_bh(&txdata->lock);
 	wil_vring_free(wil, vring, 1);
  out:
 
@@ -894,7 +911,6 @@
 		napi_synchronize(&wil->napi_tx);
 
 	wil_vring_free(wil, vring, 1);
-	memset(txdata, 0, sizeof(*txdata));
 }
 
 static struct vring *wil_find_tx_ucast(struct wil6210_priv *wil,