mac80211: use RCU_INIT_POINTER

rcu_assign_pointer() ensures that the initialization of a structure is
carried out before storing a pointer to that structure. However, in the
case that NULL is assigned there's no structure to initialize so using
RCU_INIT_POINTER instead is safe and more efficient.

Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
[squash eight tiny patches, rewrite commit log]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

8 files changed, 17 insertions, 17 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index aaa59d719592..906bc3b05aae 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1566,7 +1566,7 @@ static int ieee80211_change_station(struct wiphy *wiphy,
 
                 if (sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
                     sta->sdata->u.vlan.sta) {
-                        rcu_assign_pointer(sta->sdata->u.vlan.sta, NULL);
+                        RCU_INIT_POINTER(sta->sdata->u.vlan.sta, NULL);
                         prev_4addr = true;
                 }
 
diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index bd1fd8ea5105..b297bd3043a8 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -392,7 +392,7 @@ static void ieee80211_unassign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
         lockdep_assert_held(&local->chanctx_mtx);
 
         ctx->refcount--;
-        rcu_assign_pointer(sdata->vif.chanctx_conf, NULL);
+        RCU_INIT_POINTER(sdata->vif.chanctx_conf, NULL);
 
         sdata->vif.bss_conf.idle = true;
 
diff --git a/net/mac80211/debugfs.c b/net/mac80211/debugfs.c
index fa16e54980a1..0e963bc1ceac 100644
--- a/net/mac80211/debugfs.c
+++ b/net/mac80211/debugfs.c
@@ -128,7 +128,7 @@ static ssize_t sta_tx_latency_stat_write(struct file *file,
         if (!strcmp(buf, TX_LATENCY_DISABLED)) {
                 if (!tx_latency)
                         goto unlock;
-                rcu_assign_pointer(local->tx_latency, NULL);
+                RCU_INIT_POINTER(local->tx_latency, NULL);
                 synchronize_rcu();
                 kfree(tx_latency);
                 goto unlock;
diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index 06d28787945b..35e4f94d7ba1 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -253,7 +253,7 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 
         presp = rcu_dereference_protected(ifibss->presp,
                                           lockdep_is_held(&sdata->wdev.mtx));
-        rcu_assign_pointer(ifibss->presp, NULL);
+        RCU_INIT_POINTER(ifibss->presp, NULL);
         if (presp)
                 kfree_rcu(presp, rcu_head);
 
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index b8d331e7d883..4826c8f5d0b2 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -423,7 +423,7 @@ int ieee80211_add_virtual_monitor(struct ieee80211_local *local)
         mutex_unlock(&local->mtx);
         if (ret) {
                 mutex_lock(&local->iflist_mtx);
-                rcu_assign_pointer(local->monitor_sdata, NULL);
+                RCU_INIT_POINTER(local->monitor_sdata, NULL);
                 mutex_unlock(&local->iflist_mtx);
                 synchronize_net();
                 drv_remove_interface(local, sdata);
@@ -452,7 +452,7 @@ void ieee80211_del_virtual_monitor(struct ieee80211_local *local)
                 return;
         }
 
-        rcu_assign_pointer(local->monitor_sdata, NULL);
+        RCU_INIT_POINTER(local->monitor_sdata, NULL);
         mutex_unlock(&local->iflist_mtx);
 
         synchronize_net();
@@ -876,7 +876,7 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
         switch (sdata->vif.type) {
         case NL80211_IFTYPE_AP_VLAN:
                 list_del(&sdata->u.vlan.list);
-                rcu_assign_pointer(sdata->vif.chanctx_conf, NULL);
+                RCU_INIT_POINTER(sdata->vif.chanctx_conf, NULL);
                 /* no need to tell driver */
                 break;
         case NL80211_IFTYPE_MONITOR:
@@ -895,7 +895,7 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
                 break;
         case NL80211_IFTYPE_P2P_DEVICE:
                 /* relies on synchronize_rcu() below */
-                rcu_assign_pointer(local->p2p_sdata, NULL);
+                RCU_INIT_POINTER(local->p2p_sdata, NULL);
                 /* fall through */
         default:
                 cancel_work_sync(&sdata->work);
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index f70e9cd10552..387f61c4557d 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -829,7 +829,7 @@ void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata)
         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
         bcn = rcu_dereference_protected(ifmsh->beacon,
                                         lockdep_is_held(&sdata->wdev.mtx));
-        rcu_assign_pointer(ifmsh->beacon, NULL);
+        RCU_INIT_POINTER(ifmsh->beacon, NULL);
         kfree_rcu(bcn, rcu_head);
 
         /* flush STAs and mpaths on this iface */
@@ -1068,7 +1068,7 @@ int ieee80211_mesh_finish_csa(struct ieee80211_sub_if_data *sdata)
 
         /* Remove the CSA and MCSP elements from the beacon */
         tmp_csa_settings = rcu_dereference(ifmsh->csa);
-        rcu_assign_pointer(ifmsh->csa, NULL);
+        RCU_INIT_POINTER(ifmsh->csa, NULL);
         if (tmp_csa_settings)
                 kfree_rcu(tmp_csa_settings, rcu_head);
         ret = ieee80211_mesh_rebuild_beacon(sdata);
@@ -1102,7 +1102,7 @@ int ieee80211_mesh_csa_beacon(struct ieee80211_sub_if_data *sdata,
         ret = ieee80211_mesh_rebuild_beacon(sdata);
         if (ret) {
                 tmp_csa_settings = rcu_dereference(ifmsh->csa);
-                rcu_assign_pointer(ifmsh->csa, NULL);
+                RCU_INIT_POINTER(ifmsh->csa, NULL);
                 kfree_rcu(tmp_csa_settings, rcu_head);
                 return ret;
         }
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 3ce7f2c8539a..28185c8dc19a 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -309,7 +309,7 @@ static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
         if (local->scan_req != local->int_scan_req)
                 cfg80211_scan_done(local->scan_req, aborted);
         local->scan_req = NULL;
-        rcu_assign_pointer(local->scan_sdata, NULL);
+        RCU_INIT_POINTER(local->scan_sdata, NULL);
 
         local->scanning = 0;
         local->scan_chandef.chan = NULL;
@@ -559,7 +559,7 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
                 ieee80211_recalc_idle(local);
 
                 local->scan_req = NULL;
-                rcu_assign_pointer(local->scan_sdata, NULL);
+                RCU_INIT_POINTER(local->scan_sdata, NULL);
         }
 
         return rc;
@@ -773,7 +773,7 @@ void ieee80211_scan_work(struct work_struct *work)
                 int rc;
 
                 local->scan_req = NULL;
-                rcu_assign_pointer(local->scan_sdata, NULL);
+                RCU_INIT_POINTER(local->scan_sdata, NULL);
 
                 rc = __ieee80211_start_scan(sdata, req);
                 if (rc) {
@@ -1014,7 +1014,7 @@ out_free:
 
         if (ret) {
                 /* Clean in case of failure after HW restart or upon resume. */
-                rcu_assign_pointer(local->sched_scan_sdata, NULL);
+                RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
                 local->sched_scan_req = NULL;
         }
 
@@ -1089,7 +1089,7 @@ void ieee80211_sched_scan_stopped_work(struct work_struct *work)
                 return;
         }
 
-        rcu_assign_pointer(local->sched_scan_sdata, NULL);
+        RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
 
         /* If sched scan was aborted by the driver. */
         local->sched_scan_req = NULL;
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 5cf62ec74c14..73af7398850b 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1546,7 +1546,7 @@ int ieee80211_reconfig(struct ieee80211_local *local)
                 WARN_ON(local->resuming);
                 res = drv_add_interface(local, sdata);
                 if (WARN_ON(res)) {
-                        rcu_assign_pointer(local->monitor_sdata, NULL);
+                        RCU_INIT_POINTER(local->monitor_sdata, NULL);
                         synchronize_net();
                         kfree(sdata);
                 }