From d8675a63518c6148827838058feb7f18403faed1 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 17 Jun 2022 22:36:37 +0200 Subject: wifi: mac80211: RCU-ify link/link_conf pointers Since links can be added and removed dynamically, we need to somehow protect the sdata->link[] and vif->link_conf[] array pointers from disappearing when accessing them without locks. RCU-ify the pointers to achieve this, which requires quite a bit of rework. Signed-off-by: Johannes Berg --- net/mac80211/vht.c | 62 +++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 43 insertions(+), 19 deletions(-) (limited to 'net/mac80211/vht.c') diff --git a/net/mac80211/vht.c b/net/mac80211/vht.c index fa14627b499a..c804890dc623 100644 --- a/net/mac80211/vht.c +++ b/net/mac80211/vht.c @@ -341,39 +341,50 @@ ieee80211_sta_cap_rx_bw(struct link_sta_info *link_sta) { unsigned int link_id = link_sta->link_id; struct ieee80211_sub_if_data *sdata = link_sta->sta->sdata; - struct ieee80211_bss_conf *link_conf = sdata->vif.link_conf[link_id]; struct ieee80211_sta_vht_cap *vht_cap = &link_sta->pub->vht_cap; struct ieee80211_sta_he_cap *he_cap = &link_sta->pub->he_cap; struct ieee80211_sta_eht_cap *eht_cap = &link_sta->pub->eht_cap; u32 cap_width; if (he_cap->has_he) { + struct ieee80211_bss_conf *link_conf; + enum ieee80211_sta_rx_bandwidth ret; u8 info; + rcu_read_lock(); + link_conf = rcu_dereference(sdata->vif.link_conf[link_id]); + if (eht_cap->has_eht && link_conf->chandef.chan->band == NL80211_BAND_6GHZ) { info = eht_cap->eht_cap_elem.phy_cap_info[0]; - if (info & IEEE80211_EHT_PHY_CAP0_320MHZ_IN_6GHZ) - return IEEE80211_STA_RX_BW_320; + if (info & IEEE80211_EHT_PHY_CAP0_320MHZ_IN_6GHZ) { + ret = IEEE80211_STA_RX_BW_320; + goto out; + } } info = he_cap->he_cap_elem.phy_cap_info[0]; if (link_conf->chandef.chan->band == NL80211_BAND_2GHZ) { if (info & IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_40MHZ_IN_2G) - return IEEE80211_STA_RX_BW_40; + ret = IEEE80211_STA_RX_BW_40; else - return IEEE80211_STA_RX_BW_20; + ret = IEEE80211_STA_RX_BW_20; + goto out; } if (info & IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_160MHZ_IN_5G || info & IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_80PLUS80_MHZ_IN_5G) - return IEEE80211_STA_RX_BW_160; + ret = IEEE80211_STA_RX_BW_160; else if (info & IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_40MHZ_80MHZ_IN_5G) - return IEEE80211_STA_RX_BW_80; + ret = IEEE80211_STA_RX_BW_80; + else + ret = IEEE80211_STA_RX_BW_20; +out: + rcu_read_unlock(); - return IEEE80211_STA_RX_BW_20; + return ret; } if (!vht_cap->vht_supported) @@ -481,11 +492,18 @@ enum ieee80211_sta_rx_bandwidth ieee80211_sta_cur_vht_bw(struct link_sta_info *link_sta) { struct sta_info *sta = link_sta->sta; - struct ieee80211_bss_conf *link_conf = - sta->sdata->vif.link_conf[link_sta->link_id]; - enum nl80211_chan_width bss_width = link_conf->chandef.width; + struct ieee80211_bss_conf *link_conf; + enum nl80211_chan_width bss_width; enum ieee80211_sta_rx_bandwidth bw; + rcu_read_lock(); + link_conf = rcu_dereference(sta->sdata->vif.link_conf[link_sta->link_id]); + if (WARN_ON(!link_conf)) + bss_width = NL80211_CHAN_WIDTH_20_NOHT; + else + bss_width = link_conf->chandef.width; + rcu_read_unlock(); + bw = ieee80211_sta_cap_rx_bw(link_sta); bw = min(bw, link_sta->cur_max_bandwidth); @@ -659,10 +677,10 @@ u32 __ieee80211_vht_handle_opmode(struct ieee80211_sub_if_data *sdata, } void ieee80211_process_mu_groups(struct ieee80211_sub_if_data *sdata, - unsigned int link_id, + struct ieee80211_link_data *link, struct ieee80211_mgmt *mgmt) { - struct ieee80211_bss_conf *link_conf = sdata->vif.link_conf[link_id]; + struct ieee80211_bss_conf *link_conf = link->conf; if (!link_conf->mu_mimo_owner) return; @@ -680,19 +698,25 @@ void ieee80211_process_mu_groups(struct ieee80211_sub_if_data *sdata, mgmt->u.action.u.vht_group_notif.position, WLAN_USER_POSITION_LEN); - ieee80211_link_info_change_notify(sdata, link_id, BSS_CHANGED_MU_GROUPS); + ieee80211_link_info_change_notify(sdata, link, + BSS_CHANGED_MU_GROUPS); } void ieee80211_update_mu_groups(struct ieee80211_vif *vif, unsigned int link_id, const u8 *membership, const u8 *position) { - struct ieee80211_bss_conf *link_conf = vif->link_conf[link_id]; + struct ieee80211_bss_conf *link_conf; - if (WARN_ON_ONCE(!link_conf->mu_mimo_owner)) - return; + rcu_read_lock(); + link_conf = rcu_dereference(vif->link_conf[link_id]); - memcpy(link_conf->mu_group.membership, membership, WLAN_MEMBERSHIP_LEN); - memcpy(link_conf->mu_group.position, position, WLAN_USER_POSITION_LEN); + if (!WARN_ON_ONCE(!link_conf || !link_conf->mu_mimo_owner)) { + memcpy(link_conf->mu_group.membership, membership, + WLAN_MEMBERSHIP_LEN); + memcpy(link_conf->mu_group.position, position, + WLAN_USER_POSITION_LEN); + } + rcu_read_unlock(); } EXPORT_SYMBOL_GPL(ieee80211_update_mu_groups); -- cgit v1.2.3