cfg80211/mac80211: revert to stack allocation for sinfo

Arend's previous patch made the sinfo structure smaller
again by to dynamically allocating the per-tid stats
only when needed. Thus, revert to stack allocation for
the struct to simplify the code.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

3 files changed, 48 insertions, 93 deletions

diff --git a/net/mac80211/ethtool.c b/net/mac80211/ethtool.c
index 09210aa8ea9a..2ba5686cbcab 100644
--- a/net/mac80211/ethtool.c
+++ b/net/mac80211/ethtool.c
@@ -71,15 +71,11 @@ static void ieee80211_get_stats(struct net_device *dev,
         struct ieee80211_channel *channel;
         struct sta_info *sta;
         struct ieee80211_local *local = sdata->local;
-        struct station_info *sinfo;
+        struct station_info sinfo;
         struct survey_info survey;
         int i, q;
 #define STA_STATS_SURVEY_LEN 7
 
-        sinfo = kmalloc(sizeof(*sinfo), GFP_KERNEL);
-        if (!sinfo)
-                return;
-
         memset(data, 0, sizeof(u64) * STA_STATS_LEN);
 
 #define ADD_STA_STATS(sta)                                      \
@@ -90,8 +86,8 @@ static void ieee80211_get_stats(struct net_device *dev,
                 data[i++] += sta->rx_stats.fragments;           \
                 data[i++] += sta->rx_stats.dropped;             \
                                                                 \
-                data[i++] += sinfo->tx_packets;                 \
-                data[i++] += sinfo->tx_bytes;                   \
+                data[i++] += sinfo.tx_packets;                  \
+                data[i++] += sinfo.tx_bytes;                    \
                 data[i++] += sta->status_stats.filtered;        \
                 data[i++] += sta->status_stats.retry_failed;    \
                 data[i++] += sta->status_stats.retry_count;     \
@@ -111,8 +107,8 @@ static void ieee80211_get_stats(struct net_device *dev,
                 if (!(sta && !WARN_ON(sta->sdata->dev != dev)))
                         goto do_survey;
 
-                memset(sinfo, 0, sizeof(*sinfo));
-                sta_set_sinfo(sta, sinfo);
+                memset(&sinfo, 0, sizeof(sinfo));
+                sta_set_sinfo(sta, &sinfo);
 
                 i = 0;
                 ADD_STA_STATS(sta);
@@ -120,17 +116,17 @@ static void ieee80211_get_stats(struct net_device *dev,
                 data[i++] = sta->sta_state;
 
 
-                if (sinfo->filled & BIT(NL80211_STA_INFO_TX_BITRATE))
+                if (sinfo.filled & BIT(NL80211_STA_INFO_TX_BITRATE))
                         data[i] = 100000ULL *
-                                cfg80211_calculate_bitrate(&sinfo->txrate);
+                                cfg80211_calculate_bitrate(&sinfo.txrate);
                 i++;
-                if (sinfo->filled & BIT(NL80211_STA_INFO_RX_BITRATE))
+                if (sinfo.filled & BIT(NL80211_STA_INFO_RX_BITRATE))
                         data[i] = 100000ULL *
-                                cfg80211_calculate_bitrate(&sinfo->rxrate);
+                                cfg80211_calculate_bitrate(&sinfo.rxrate);
                 i++;
 
-                if (sinfo->filled & BIT(NL80211_STA_INFO_SIGNAL_AVG))
-                        data[i] = (u8)sinfo->signal_avg;
+                if (sinfo.filled & BIT(NL80211_STA_INFO_SIGNAL_AVG))
+                        data[i] = (u8)sinfo.signal_avg;
                 i++;
         } else {
                 list_for_each_entry(sta, &local->sta_list, list) {
@@ -138,16 +134,14 @@ static void ieee80211_get_stats(struct net_device *dev,
                         if (sta->sdata->dev != dev)
                                 continue;
 
-                        memset(sinfo, 0, sizeof(*sinfo));
-                        sta_set_sinfo(sta, sinfo);
+                        memset(&sinfo, 0, sizeof(sinfo));
+                        sta_set_sinfo(sta, &sinfo);
                         i = 0;
                         ADD_STA_STATS(sta);
                 }
         }
 
 do_survey:
-        kfree(sinfo);
-
         i = STA_STATS_LEN - STA_STATS_SURVEY_LEN;
         /* Get survey stats for current channel */
         survey.filled = 0;
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 3d638f11edb5..7daceb1f253d 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -4723,17 +4723,13 @@ static int nl80211_send_station(struct sk_buff *msg, u32 cmd, u32 portid,
 static int nl80211_dump_station(struct sk_buff *skb,
                                 struct netlink_callback *cb)
 {
-        struct station_info *sinfo;
+        struct station_info sinfo;
         struct cfg80211_registered_device *rdev;
         struct wireless_dev *wdev;
         u8 mac_addr[ETH_ALEN];
         int sta_idx = cb->args[2];
         int err;
 
-        sinfo = kzalloc(sizeof(*sinfo), GFP_KERNEL);
-        if (!sinfo)
-                return -ENOMEM;
-
         rtnl_lock();
         err = nl80211_prepare_wdev_dump(skb, cb, &rdev, &wdev);
         if (err)
@@ -4750,9 +4746,9 @@ static int nl80211_dump_station(struct sk_buff *skb,
         }
 
         while (1) {
-                memset(sinfo, 0, sizeof(*sinfo));
+                memset(&sinfo, 0, sizeof(sinfo));
                 err = rdev_dump_station(rdev, wdev->netdev, sta_idx,
-                                        mac_addr, sinfo);
+                                        mac_addr, &sinfo);
                 if (err == -ENOENT)
                         break;
                 if (err)
@@ -4762,7 +4758,7 @@ static int nl80211_dump_station(struct sk_buff *skb,
                                 NETLINK_CB(cb->skb).portid,
                                 cb->nlh->nlmsg_seq, NLM_F_MULTI,
                                 rdev, wdev->netdev, mac_addr,
-                                sinfo) < 0)
+                                &sinfo) < 0)
                         goto out;
 
                 sta_idx++;
@@ -4773,7 +4769,6 @@ static int nl80211_dump_station(struct sk_buff *skb,
         err = skb->len;
  out_err:
         rtnl_unlock();
-        kfree(sinfo);
 
         return err;
 }
@@ -4782,49 +4777,37 @@ static int nl80211_get_station(struct sk_buff *skb, struct genl_info *info)
 {
         struct cfg80211_registered_device *rdev = info->user_ptr[0];
         struct net_device *dev = info->user_ptr[1];
-        struct station_info *sinfo;
+        struct station_info sinfo;
         struct sk_buff *msg;
         u8 *mac_addr = NULL;
         int err;
 
-        sinfo = kzalloc(sizeof(*sinfo), GFP_KERNEL);
-        if (!sinfo)
-                return -ENOMEM;
+        memset(&sinfo, 0, sizeof(sinfo));
 
-        if (!info->attrs[NL80211_ATTR_MAC]) {
-                err = -EINVAL;
-                goto out;
-        }
+        if (!info->attrs[NL80211_ATTR_MAC])
+                return -EINVAL;
 
         mac_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
 
-        if (!rdev->ops->get_station) {
-                err = -EOPNOTSUPP;
-                goto out;
-        }
+        if (!rdev->ops->get_station)
+                return -EOPNOTSUPP;
 
-        err = rdev_get_station(rdev, dev, mac_addr, sinfo);
+        err = rdev_get_station(rdev, dev, mac_addr, &sinfo);
         if (err)
-                goto out;
+                return err;
 
         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
-        if (!msg) {
-                err = -ENOMEM;
-                goto out;
-        }
+        if (!msg)
+                return -ENOMEM;
 
         if (nl80211_send_station(msg, NL80211_CMD_NEW_STATION,
                                  info->snd_portid, info->snd_seq, 0,
-                                 rdev, dev, mac_addr, sinfo) < 0) {
+                                 rdev, dev, mac_addr, &sinfo) < 0) {
                 nlmsg_free(msg);
-                err = -ENOBUFS;
-                goto out;
+                return -ENOBUFS;
         }
 
-        err = genlmsg_reply(msg, info);
-out:
-        kfree(sinfo);
-        return err;
+        return genlmsg_reply(msg, info);
 }
 
 int cfg80211_check_station_change(struct wiphy *wiphy,
@@ -10088,26 +10071,18 @@ static int cfg80211_cqm_rssi_update(struct cfg80211_registered_device *rdev,
          */
         if (!wdev->cqm_config->last_rssi_event_value && wdev->current_bss &&
             rdev->ops->get_station) {
-                struct station_info *sinfo;
+                struct station_info sinfo = {};
                 u8 *mac_addr;
 
-                sinfo = kzalloc(sizeof(*sinfo), GFP_KERNEL);
-                if (!sinfo)
-                        return -ENOMEM;
-
                 mac_addr = wdev->current_bss->pub.bssid;
 
-                err = rdev_get_station(rdev, dev, mac_addr, sinfo);
-                if (err) {
-                        kfree(sinfo);
+                err = rdev_get_station(rdev, dev, mac_addr, &sinfo);
+                if (err)
                         return err;
-                }
 
-                if (sinfo->filled & BIT(NL80211_STA_INFO_BEACON_SIGNAL_AVG))
+                if (sinfo.filled & BIT(NL80211_STA_INFO_BEACON_SIGNAL_AVG))
                         wdev->cqm_config->last_rssi_event_value =
-                                (s8)sinfo->rx_beacon_signal_avg;
-
-                kfree(sinfo);
+                                (s8) sinfo.rx_beacon_signal_avg;
         }
 
         last = wdev->cqm_config->last_rssi_event_value;
@@ -14641,32 +14616,25 @@ void cfg80211_del_sta_sinfo(struct net_device *dev, const u8 *mac_addr,
         struct wiphy *wiphy = dev->ieee80211_ptr->wiphy;
         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
         struct sk_buff *msg;
-        struct station_info *empty_sinfo = NULL;
+        struct station_info empty_sinfo = {};
 
-        if (!sinfo) {
-                empty_sinfo = kzalloc(sizeof(*empty_sinfo), GFP_KERNEL);
-                if (!empty_sinfo)
-                        return;
-                sinfo = empty_sinfo;
-        }
+        if (!sinfo)
+                sinfo = &empty_sinfo;
 
         trace_cfg80211_del_sta(dev, mac_addr);
 
         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp);
         if (!msg)
-                goto out;
+                return;
 
         if (nl80211_send_station(msg, NL80211_CMD_DEL_STATION, 0, 0, 0,
                                  rdev, dev, mac_addr, sinfo) < 0) {
                 nlmsg_free(msg);
-                goto out;
+                return;
         }
 
         genlmsg_multicast_netns(&nl80211_fam, wiphy_net(&rdev->wiphy), msg, 0,
                                 NL80211_MCGRP_MLME, gfp);
-
-out:
-        kfree(empty_sinfo);
 }
 EXPORT_SYMBOL(cfg80211_del_sta_sinfo);
 
diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c
index 9e002df0f8d8..05186a47878f 100644
--- a/net/wireless/wext-compat.c
+++ b/net/wireless/wext-compat.c
@@ -1254,7 +1254,7 @@ static int cfg80211_wext_giwrate(struct net_device *dev,
 {
         struct wireless_dev *wdev = dev->ieee80211_ptr;
         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
-        struct station_info *sinfo;
+        struct station_info sinfo = {};
         u8 addr[ETH_ALEN];
         int err;
 
@@ -1274,23 +1274,16 @@ static int cfg80211_wext_giwrate(struct net_device *dev,
         if (err)
                 return err;
 
-        sinfo = kzalloc(sizeof(*sinfo), GFP_KERNEL);
-        if (!sinfo)
-                return -ENOMEM;
-
-        err = rdev_get_station(rdev, dev, addr, sinfo);
+        err = rdev_get_station(rdev, dev, addr, &sinfo);
         if (err)
-                goto out;
+                return err;
 
-        if (!(sinfo->filled & BIT(NL80211_STA_INFO_TX_BITRATE))) {
-                err = -EOPNOTSUPP;
-                goto out;
-        }
+        if (!(sinfo.filled & BIT(NL80211_STA_INFO_TX_BITRATE)))
+                return -EOPNOTSUPP;
 
-        rate->value = 100000 * cfg80211_calculate_bitrate(&sinfo->txrate);
-out:
-        kfree(sinfo);
-        return err;
+        rate->value = 100000 * cfg80211_calculate_bitrate(&sinfo.txrate);
+
+        return 0;
 }
 
 /* Get wireless statistics.  Called by /proc/net/wireless and by SIOCGIWSTATS */