From 0c2bef4621c5feb5bda9068c9964b2e9acf57017 Mon Sep 17 00:00:00 2001 From: Monam Agarwal Date: Mon, 24 Mar 2014 00:51:43 +0530 Subject: [PATCH] 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 [squash eight tiny patches, rewrite commit log] Signed-off-by: Johannes Berg --- net/mac80211/cfg.c | 2 +- net/mac80211/chan.c | 2 +- net/mac80211/debugfs.c | 2 +- net/mac80211/ibss.c | 2 +- net/mac80211/iface.c | 8 ++++---- net/mac80211/mesh.c | 6 +++--- net/mac80211/scan.c | 10 +++++----- net/mac80211/util.c | 2 +- 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); } -- 2.20.1