iwlwifi: fix and add missing sta_lock usage

There are a few places where sta_lock is used, but the
station information protected by it is accessed outside
of the lock. Address this in two ways, if the access
won't sleep then just move the access into the lock, if
the access can sleep then copy the needed station
information to the stack to be accessed without risk of
it changing while access in progress.

Additionally, a number of other places access station
station information without holding the sta_lock, fix
those as well.

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-sta.c b/drivers/net/wireless/iwlwifi/iwl-sta.c
index 2eafba6..4d878d8 100644
--- a/drivers/net/wireless/iwlwifi/iwl-sta.c
+++ b/drivers/net/wireless/iwlwifi/iwl-sta.c
@@ -311,10 +311,10 @@
 				  struct ieee80211_sta_ht_cap *ht_info,
 				  u8 *sta_id_r)
 {
-	struct iwl_station_entry *station;
 	unsigned long flags_spin;
 	int ret = 0;
 	u8 sta_id;
+	struct iwl_addsta_cmd sta_cmd;
 
 	*sta_id_r = 0;
 	spin_lock_irqsave(&priv->sta_lock, flags_spin);
@@ -347,14 +347,15 @@
 	}
 
 	priv->stations[sta_id].used |= IWL_STA_UCODE_INPROGRESS;
-	station = &priv->stations[sta_id];
+	memcpy(&sta_cmd, &priv->stations[sta_id].sta, sizeof(struct iwl_addsta_cmd));
 	spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
 
 	/* Add station to device's station table */
-	ret = iwl_send_add_sta(priv, &station->sta, CMD_SYNC);
+	ret = iwl_send_add_sta(priv, &sta_cmd, CMD_SYNC);
 	if (ret) {
-		IWL_ERR(priv, "Adding station %pM failed.\n", station->sta.sta.addr);
 		spin_lock_irqsave(&priv->sta_lock, flags_spin);
+		IWL_ERR(priv, "Adding station %pM failed.\n",
+			priv->stations[sta_id].sta.sta.addr);
 		priv->stations[sta_id].used &= ~IWL_STA_DRIVER_ACTIVE;
 		priv->stations[sta_id].used &= ~IWL_STA_UCODE_INPROGRESS;
 		spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
@@ -488,7 +489,7 @@
 }
 
 static int iwl_send_remove_station(struct iwl_priv *priv,
-				   struct iwl_station_entry *station)
+				   const u8 *addr, int sta_id)
 {
 	struct iwl_rx_packet *pkt;
 	int ret;
@@ -505,7 +506,7 @@
 
 	memset(&rm_sta_cmd, 0, sizeof(rm_sta_cmd));
 	rm_sta_cmd.num_sta = 1;
-	memcpy(&rm_sta_cmd.addr, &station->sta.sta.addr , ETH_ALEN);
+	memcpy(&rm_sta_cmd.addr, addr, ETH_ALEN);
 
 	cmd.flags |= CMD_WANT_SKB;
 
@@ -525,7 +526,7 @@
 		switch (pkt->u.rem_sta.status) {
 		case REM_STA_SUCCESS_MSK:
 			spin_lock_irqsave(&priv->sta_lock, flags_spin);
-			iwl_sta_ucode_deactivate(priv, station->sta.sta.sta_id);
+			iwl_sta_ucode_deactivate(priv, sta_id);
 			spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
 			IWL_DEBUG_ASSOC(priv, "REPLY_REMOVE_STA PASSED\n");
 			break;
@@ -546,7 +547,6 @@
 int iwl_remove_station(struct iwl_priv *priv, const u8 sta_id,
 		       const u8 *addr)
 {
-	struct iwl_station_entry *station;
 	unsigned long flags;
 
 	if (!iwl_is_ready(priv)) {
@@ -592,10 +592,9 @@
 
 	BUG_ON(priv->num_stations < 0);
 
-	station = &priv->stations[sta_id];
 	spin_unlock_irqrestore(&priv->sta_lock, flags);
 
-	return iwl_send_remove_station(priv, station);
+	return iwl_send_remove_station(priv, addr, sta_id);
 out_err:
 	spin_unlock_irqrestore(&priv->sta_lock, flags);
 	return -EINVAL;
@@ -643,11 +642,13 @@
  */
 void iwl_restore_stations(struct iwl_priv *priv)
 {
-	struct iwl_station_entry *station;
+	struct iwl_addsta_cmd sta_cmd;
+	struct iwl_link_quality_cmd lq;
 	unsigned long flags_spin;
 	int i;
 	bool found = false;
 	int ret;
+	bool send_lq;
 
 	if (!iwl_is_ready(priv)) {
 		IWL_DEBUG_INFO(priv, "Not ready yet, not restoring any stations.\n");
@@ -669,13 +670,20 @@
 
 	for (i = 0; i < priv->hw_params.max_stations; i++) {
 		if ((priv->stations[i].used & IWL_STA_UCODE_INPROGRESS)) {
+			memcpy(&sta_cmd, &priv->stations[i].sta,
+			       sizeof(struct iwl_addsta_cmd));
+			send_lq = false;
+			if (priv->stations[i].lq) {
+				memcpy(&lq, priv->stations[i].lq,
+				       sizeof(struct iwl_link_quality_cmd));
+				send_lq = true;
+			}
 			spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
-			station = &priv->stations[i];
-			ret = iwl_send_add_sta(priv, &priv->stations[i].sta, CMD_SYNC);
+			ret = iwl_send_add_sta(priv, &sta_cmd, CMD_SYNC);
 			if (ret) {
-				IWL_ERR(priv, "Adding station %pM failed.\n",
-					station->sta.sta.addr);
 				spin_lock_irqsave(&priv->sta_lock, flags_spin);
+				IWL_ERR(priv, "Adding station %pM failed.\n",
+					priv->stations[i].sta.sta.addr);
 				priv->stations[i].used &= ~IWL_STA_DRIVER_ACTIVE;
 				priv->stations[i].used &= ~IWL_STA_UCODE_INPROGRESS;
 				spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
@@ -684,8 +692,8 @@
 			 * Rate scaling has already been initialized, send
 			 * current LQ command
 			 */
-			if (station->lq)
-				iwl_send_lq_cmd(priv, station->lq, CMD_SYNC, true);
+			if (send_lq)
+				iwl_send_lq_cmd(priv, &lq, CMD_SYNC, true);
 			spin_lock_irqsave(&priv->sta_lock, flags_spin);
 			priv->stations[i].used &= ~IWL_STA_UCODE_INPROGRESS;
 		}
@@ -1269,9 +1277,8 @@
 	priv->stations[sta_id].sta.sta.modify_mask = STA_MODIFY_TID_DISABLE_TX;
 	priv->stations[sta_id].sta.tid_disable_tx &= cpu_to_le16(~(1 << tid));
 	priv->stations[sta_id].sta.mode = STA_CONTROL_MODIFY_MSK;
-	spin_unlock_irqrestore(&priv->sta_lock, flags);
-
 	iwl_send_add_sta(priv, &priv->stations[sta_id].sta, CMD_ASYNC);
+	spin_unlock_irqrestore(&priv->sta_lock, flags);
 }
 EXPORT_SYMBOL(iwl_sta_tx_modify_enable_tid);
 
@@ -1302,7 +1309,7 @@
 			int tid)
 {
 	unsigned long flags;
-	int sta_id;
+	int sta_id, ret;
 
 	sta_id = iwl_sta_id(sta);
 	if (sta_id == IWL_INVALID_STATION) {
@@ -1315,10 +1322,11 @@
 	priv->stations[sta_id].sta.sta.modify_mask = STA_MODIFY_DELBA_TID_MSK;
 	priv->stations[sta_id].sta.remove_immediate_ba_tid = (u8)tid;
 	priv->stations[sta_id].sta.mode = STA_CONTROL_MODIFY_MSK;
+	ret = iwl_send_add_sta(priv, &priv->stations[sta_id].sta, CMD_ASYNC);
 	spin_unlock_irqrestore(&priv->sta_lock, flags);
 
-	return iwl_send_add_sta(priv, &priv->stations[sta_id].sta,
-					CMD_ASYNC);
+	return ret;
+
 }
 EXPORT_SYMBOL(iwl_sta_rx_agg_stop);
 
@@ -1332,9 +1340,9 @@
 	priv->stations[sta_id].sta.sta.modify_mask = 0;
 	priv->stations[sta_id].sta.sleep_tx_count = 0;
 	priv->stations[sta_id].sta.mode = STA_CONTROL_MODIFY_MSK;
+	iwl_send_add_sta(priv, &priv->stations[sta_id].sta, CMD_ASYNC);
 	spin_unlock_irqrestore(&priv->sta_lock, flags);
 
-	iwl_send_add_sta(priv, &priv->stations[sta_id].sta, CMD_ASYNC);
 }
 EXPORT_SYMBOL(iwl_sta_modify_ps_wake);
 
@@ -1349,9 +1357,9 @@
 					STA_MODIFY_SLEEP_TX_COUNT_MSK;
 	priv->stations[sta_id].sta.sleep_tx_count = cpu_to_le16(cnt);
 	priv->stations[sta_id].sta.mode = STA_CONTROL_MODIFY_MSK;
+	iwl_send_add_sta(priv, &priv->stations[sta_id].sta, CMD_ASYNC);
 	spin_unlock_irqrestore(&priv->sta_lock, flags);
 
-	iwl_send_add_sta(priv, &priv->stations[sta_id].sta, CMD_ASYNC);
 }
 EXPORT_SYMBOL(iwl_sta_modify_sleep_tx_count);