Commit 6d10e46b authored by Johannes Berg's avatar Johannes Berg
Browse files

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: default avatarJohannes Berg <johannes.berg@intel.com>
parent 3b8d9c29

net/mac80211/key.c

+68 −13
Original line number Diff line number Diff line
@@ -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,

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;

net/mac80211/key.h

+2 −0
Original line number Diff line number Diff line
@@ -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) \

net/mac80211/sta_info.c

+3 −9
Original line number Diff line number Diff line
@@ -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;

CRA Git | Maintained and supported by SUSTech CRA and CCSE