mac80211: batch key free synchronize_net()

Instead of calling synchronize_net() for every key
on an interface or when a station is removed, do it
only once for all keys in both of these cases.

As a side-effect, removing station keys now always
calls synchronize_net() even if there are no keys,
which fixes an issue with station removal happening
in the driver while the station could still be used
for TX.

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

diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index 953887bdc638a69a3aed9ece545ca8360e43528b..67059b88fea5f28619c97ad2ca8c150840045055 100644 (file)
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -406,18 +406,9 @@ static void ieee80211_key_free_common(struct ieee80211_key *key)
        kfree(key);
 }
 
-static void ieee80211_key_destroy(struct ieee80211_key *key,
-                                 bool delay_tailroom)
+static void __ieee80211_key_destroy(struct ieee80211_key *key,
+                                   bool delay_tailroom)
 {
-       if (!key)
-               return;
-
-       /*
-        * Synchronize so the TX path can no longer be using
-        * this key before we free/remove it.
-        */
-       synchronize_net();
-
        if (key->local)
                ieee80211_key_disable_hw_accel(key);
 
@@ -439,6 +430,21 @@ static void ieee80211_key_destroy(struct ieee80211_key *key,
        ieee80211_key_free_common(key);
 }
 
+static void ieee80211_key_destroy(struct ieee80211_key *key,
+                                 bool delay_tailroom)
+{
+       if (!key)
+               return;
+
+       /*
+        * Synchronize so the TX path can no longer be using
+        * this key before we free/remove it.
+        */
+       synchronize_net();
+
+       __ieee80211_key_destroy(key, delay_tailroom);
+}
+
 void ieee80211_key_free_unused(struct ieee80211_key *key)
 {
        WARN_ON(key->sdata || key->local);
@@ -560,6 +566,7 @@ EXPORT_SYMBOL(ieee80211_iter_keys);
 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
 {
        struct ieee80211_key *key, *tmp;
+       LIST_HEAD(keys);
 
        cancel_delayed_work_sync(&sdata->dec_tailroom_needed_wk);
 
@@ -571,17 +578,65 @@ void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
 
        ieee80211_debugfs_key_remove_mgmt_default(sdata);
 
-       list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
-               ieee80211_key_free(key, false);
+       list_for_each_entry_safe(key, tmp, &sdata->key_list, list) {
+               ieee80211_key_replace(key->sdata, key->sta,
+                               key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
+                               key, NULL);
+               list_add_tail(&key->list, &keys);
+       }
 
        ieee80211_debugfs_key_update_default(sdata);
 
+       if (!list_empty(&keys)) {
+               synchronize_net();
+               list_for_each_entry_safe(key, tmp, &keys, list)
+                       __ieee80211_key_destroy(key, false);
+       }
+
        WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
                     sdata->crypto_tx_tailroom_pending_dec);
 
        mutex_unlock(&sdata->local->key_mtx);
 }
 
+void ieee80211_free_sta_keys(struct ieee80211_local *local,
+                            struct sta_info *sta)
+{
+       struct ieee80211_key *key, *tmp;
+       LIST_HEAD(keys);
+       int i;
+
+       mutex_lock(&local->key_mtx);
+       for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
+               key = key_mtx_dereference(local, sta->gtk[i]);
+               if (!key)
+                       continue;
+               ieee80211_key_replace(key->sdata, key->sta,
+                               key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
+                               key, NULL);
+               list_add(&key->list, &keys);
+       }
+
+       key = key_mtx_dereference(local, sta->ptk);
+       if (key) {
+               ieee80211_key_replace(key->sdata, key->sta,
+                               key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
+                               key, NULL);
+               list_add(&key->list, &keys);
+       }
+
+       /*
+        * NB: the station code relies on this being
+        * done even if there aren't any keys
+        */
+       synchronize_net();
+
+       list_for_each_entry_safe(key, tmp, &keys, list)
+               __ieee80211_key_destroy(key, true);
+
+       mutex_unlock(&local->key_mtx);
+}
+
 void ieee80211_delayed_tailroom_dec(struct work_struct *wk)
 {
        struct ieee80211_sub_if_data *sdata;

diff --git a/net/mac80211/key.h b/net/mac80211/key.h
index a353ddd63b5b9fd13e04c3a5f3c5e29bcb498339..e8de3e6d7804be1e9562531be2d28372532897ea 100644 (file)
--- a/net/mac80211/key.h
+++ b/net/mac80211/key.h
@@ -141,6 +141,8 @@ void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
                                    int idx);
 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata);
+void ieee80211_free_sta_keys(struct ieee80211_local *local,
+                            struct sta_info *sta);
 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata);
 
 #define key_mtx_dereference(local, ref) \

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 2961f3d6b209c19fe2c1284b2dbc92b0186bdfe7..11216bc13b27565a4734638014ad01f5d2d88911 100644 (file)
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -783,7 +783,7 @@ int __must_check __sta_info_destroy(struct sta_info *sta)
 {
        struct ieee80211_local *local;
        struct ieee80211_sub_if_data *sdata;
-       int ret, i;
+       int ret;
 
        might_sleep();
 
@@ -810,14 +810,8 @@ int __must_check __sta_info_destroy(struct sta_info *sta)
 
        list_del_rcu(&sta->list);
 
-       mutex_lock(&local->key_mtx);
-       for (i = 0; i < NUM_DEFAULT_KEYS; i++)
-               ieee80211_key_free(key_mtx_dereference(local, sta->gtk[i]),
-                                  true);
-       if (sta->ptk)
-               ieee80211_key_free(key_mtx_dereference(local, sta->ptk),
-                                  true);
-       mutex_unlock(&local->key_mtx);
+       /* this always calls synchronize_net() */
+       ieee80211_free_sta_keys(local, sta);
 
        sta->dead = true;