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>

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index aaa59d719592c0b7dc6ef3ddb4df8aaa578bc45c..906bc3b05aae29e881c43dfe526f5086aeb47beb 100644 (file)
--- 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 bd1fd8ea5105fead274e09b7bcd093ba97081a97..b297bd3043a86a718479adc5d32ed8c30b25ec38 100644 (file)
--- 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 fa16e54980a1d3e76ce2f85fcb3253eb2599e838..0e963bc1ceac3109f378431a617b853a7166df37 100644 (file)
--- 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 06d28787945b513e6672457a1e6990da0fd644d8..35e4f94d7ba1113b12db2ee26d6460a712606599 100644 (file)
--- 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 b8d331e7d883d50fd4fc3adf12c2869ac3beedb7..4826c8f5d0b29553e01248d18dce72c75bd12e39 100644 (file)
--- 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 f70e9cd10552dac6729d703edd2e9ae12750a3a6..387f61c4557da313f57f4744f1add217c1b6a64f 100644 (file)
--- 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 3ce7f2c8539a1f626f7488833ee966fb3af5d502..28185c8dc19a302b31af1e0efe11dbaea8000b2f 100644 (file)
--- 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 5cf62ec74c14d0e883ba599556a411c686b09e2d..73af7398850b2683d4db8769bb3b9e1ccb932289 100644 (file)
--- 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);
                }