mac80211: don't hang on to sched_scan_ies

There's no need to keep a copy of the scheduled
scan IEs after the driver has been told, if it
requires a copy it must make one. Therefore, we
can move sched_scan_ies into the function.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/ieee80211_i.h

@@ -970,7 +970,6 @@ struct ieee80211_local {
 	int scan_channel_idx;
 	int scan_ies_len;
 
-	struct ieee80211_sched_scan_ies sched_scan_ies;
 	struct work_struct sched_scan_stopped_work;
 	struct ieee80211_sub_if_data __rcu *sched_scan_sdata;
 

net/mac80211/scan.c

@@ -917,6 +917,7 @@ int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
 				       struct cfg80211_sched_scan_request *req)
 {
 	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_sched_scan_ies sched_scan_ies;
 	int ret, i;
 
 	mutex_lock(&local->mtx);
@@ -935,33 +936,28 @@ int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
 		if (!local->hw.wiphy->bands[i])
 			continue;
 
-		local->sched_scan_ies.ie[i] = kzalloc(2 +
-						      IEEE80211_MAX_SSID_LEN +
-						      local->scan_ies_len +
-						      req->ie_len,
-						      GFP_KERNEL);
-		if (!local->sched_scan_ies.ie[i]) {
+		sched_scan_ies.ie[i] = kzalloc(2 + IEEE80211_MAX_SSID_LEN +
+					       local->scan_ies_len +
+					       req->ie_len,
+					       GFP_KERNEL);
+		if (!sched_scan_ies.ie[i]) {
 			ret = -ENOMEM;
 			goto out_free;
 		}
 
-		local->sched_scan_ies.len[i] =
-			ieee80211_build_preq_ies(local,
-						 local->sched_scan_ies.ie[i],
+		sched_scan_ies.len[i] =
+			ieee80211_build_preq_ies(local, sched_scan_ies.ie[i],
 						 req->ie, req->ie_len, i,
 						 (u32) -1, 0);
 	}
 
-	ret = drv_sched_scan_start(local, sdata, req,
-				   &local->sched_scan_ies);
-	if (ret == 0) {
+	ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
+	if (ret == 0)
 		rcu_assign_pointer(local->sched_scan_sdata, sdata);
-		goto out;
-	}
 
 out_free:
 	while (i > 0)
-		kfree(local->sched_scan_ies.ie[--i]);
+		kfree(sched_scan_ies.ie[--i]);
 out:
 	mutex_unlock(&local->mtx);
 	return ret;
@@ -970,7 +966,7 @@ int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata)
 {
 	struct ieee80211_local *local = sdata->local;
-	int ret = 0, i;
+	int ret = 0;
 
 	mutex_lock(&local->mtx);
 
@@ -979,12 +975,9 @@ int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata)
 		goto out;
 	}
 
-	if (rcu_access_pointer(local->sched_scan_sdata)) {
-		for (i = 0; i < IEEE80211_NUM_BANDS; i++)
-			kfree(local->sched_scan_ies.ie[i]);
-
+	if (rcu_access_pointer(local->sched_scan_sdata))
 		drv_sched_scan_stop(local, sdata);
-	}
+
 out:
 	mutex_unlock(&local->mtx);
 
@@ -1006,7 +999,6 @@ void ieee80211_sched_scan_stopped_work(struct work_struct *work)
 	struct ieee80211_local *local =
 		container_of(work, struct ieee80211_local,
 			     sched_scan_stopped_work);
-	int i;
 
 	mutex_lock(&local->mtx);
 
@@ -1015,9 +1007,6 @@ void ieee80211_sched_scan_stopped_work(struct work_struct *work)
 		return;
 	}
 
-	for (i = 0; i < IEEE80211_NUM_BANDS; i++)
-		kfree(local->sched_scan_ies.ie[i]);
-
 	rcu_assign_pointer(local->sched_scan_sdata, NULL);
 
 	mutex_unlock(&local->mtx);