mac80211: simplify key locking
Since I recently made station management able
to sleep, I can now rework key management as
well; since it will no longer need a spinlock
and can also use a mutex instead, a bunch of
code to allow drivers' set_key to sleep while
key management is protected by a spinlock can
now be removed.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index f8c49c5..952845e 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -120,6 +120,9 @@
struct ieee80211_key *key;
int err;
+ if (!netif_running(dev))
+ return -ENETDOWN;
+
sdata = IEEE80211_DEV_TO_SUB_IF(dev);
switch (params->cipher) {
@@ -145,7 +148,7 @@
if (!key)
return -ENOMEM;
- rcu_read_lock();
+ mutex_lock(&sdata->local->sta_mtx);
if (mac_addr) {
sta = sta_info_get_bss(sdata, mac_addr);
@@ -160,7 +163,7 @@
err = 0;
out_unlock:
- rcu_read_unlock();
+ mutex_unlock(&sdata->local->sta_mtx);
return err;
}
@@ -174,7 +177,7 @@
sdata = IEEE80211_DEV_TO_SUB_IF(dev);
- rcu_read_lock();
+ mutex_lock(&sdata->local->sta_mtx);
if (mac_addr) {
ret = -ENOENT;
@@ -202,7 +205,7 @@
ret = 0;
out_unlock:
- rcu_read_unlock();
+ mutex_unlock(&sdata->local->sta_mtx);
return ret;
}
@@ -305,15 +308,10 @@
struct net_device *dev,
u8 key_idx)
{
- struct ieee80211_sub_if_data *sdata;
+ struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
- rcu_read_lock();
-
- sdata = IEEE80211_DEV_TO_SUB_IF(dev);
ieee80211_set_default_key(sdata, key_idx);
- rcu_read_unlock();
-
return 0;
}
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 47d6753..4d3883e 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -746,10 +746,10 @@
struct mutex iflist_mtx;
/*
- * Key lock, protects sdata's key_list and sta_info's
+ * Key mutex, protects sdata's key_list and sta_info's
* key pointers (write access, they're RCU.)
*/
- spinlock_t key_lock;
+ struct mutex key_mtx;
/* Scanning and BSS list */
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 3d3a094..1afa9ec 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -268,7 +268,6 @@
changed |= ieee80211_reset_erp_info(sdata);
ieee80211_bss_info_change_notify(sdata, changed);
- ieee80211_enable_keys(sdata);
if (sdata->vif.type == NL80211_IFTYPE_STATION)
netif_carrier_off(dev);
@@ -522,8 +521,8 @@
BSS_CHANGED_BEACON_ENABLED);
}
- /* disable all keys for as long as this netdev is down */
- ieee80211_disable_keys(sdata);
+ /* free all remaining keys, there shouldn't be any */
+ ieee80211_free_keys(sdata);
drv_remove_interface(local, &sdata->vif);
}
diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index e8f6e3b..d0d9001 100644
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -36,80 +36,20 @@
* There is currently no way of knowing this except by looking into
* debugfs.
*
- * All key operations are protected internally so you can call them at
- * any time.
+ * All key operations are protected internally.
*
* Within mac80211, key references are, just as STA structure references,
* protected by RCU. Note, however, that some things are unprotected,
* namely the key->sta dereferences within the hardware acceleration
- * functions. This means that sta_info_destroy() must flush the key todo
- * list.
- *
- * All the direct key list manipulation functions must not sleep because
- * they can operate on STA info structs that are protected by RCU.
+ * functions. This means that sta_info_destroy() must remove the key
+ * which waits for an RCU grace period.
*/
static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
-/* key mutex: used to synchronise todo runners */
-static DEFINE_MUTEX(key_mutex);
-static DEFINE_SPINLOCK(todo_lock);
-static LIST_HEAD(todo_list);
-
-static void key_todo(struct work_struct *work)
+static void assert_key_lock(struct ieee80211_local *local)
{
- ieee80211_key_todo();
-}
-
-static DECLARE_WORK(todo_work, key_todo);
-
-/**
- * add_todo - add todo item for a key
- *
- * @key: key to add to do item for
- * @flag: todo flag(s)
- *
- * Must be called with IRQs or softirqs disabled.
- */
-static void add_todo(struct ieee80211_key *key, u32 flag)
-{
- if (!key)
- return;
-
- spin_lock(&todo_lock);
- key->flags |= flag;
- /*
- * Remove again if already on the list so that we move it to the end.
- */
- if (!list_empty(&key->todo))
- list_del(&key->todo);
- list_add_tail(&key->todo, &todo_list);
- schedule_work(&todo_work);
- spin_unlock(&todo_lock);
-}
-
-/**
- * ieee80211_key_lock - lock the mac80211 key operation lock
- *
- * This locks the (global) mac80211 key operation lock, all
- * key operations must be done under this lock.
- */
-static void ieee80211_key_lock(void)
-{
- mutex_lock(&key_mutex);
-}
-
-/**
- * ieee80211_key_unlock - unlock the mac80211 key operation lock
- */
-static void ieee80211_key_unlock(void)
-{
- mutex_unlock(&key_mutex);
-}
-
-static void assert_key_lock(void)
-{
- WARN_ON(!mutex_is_locked(&key_mutex));
+ WARN_ON(!mutex_is_locked(&local->key_mtx));
}
static struct ieee80211_sta *get_sta_for_key(struct ieee80211_key *key)
@@ -126,12 +66,13 @@
struct ieee80211_sta *sta;
int ret;
- assert_key_lock();
might_sleep();
if (!key->local->ops->set_key)
return;
+ assert_key_lock(key->local);
+
sta = get_sta_for_key(key);
sdata = key->sdata;
@@ -142,11 +83,8 @@
ret = drv_set_key(key->local, SET_KEY, sdata, sta, &key->conf);
- if (!ret) {
- spin_lock_bh(&todo_lock);
+ if (!ret)
key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
- spin_unlock_bh(&todo_lock);
- }
if (ret && ret != -ENOSPC && ret != -EOPNOTSUPP)
printk(KERN_ERR "mac80211-%s: failed to set key "
@@ -161,18 +99,15 @@
struct ieee80211_sta *sta;
int ret;
- assert_key_lock();
might_sleep();
if (!key || !key->local->ops->set_key)
return;
- spin_lock_bh(&todo_lock);
- if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)) {
- spin_unlock_bh(&todo_lock);
+ assert_key_lock(key->local);
+
+ if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
return;
- }
- spin_unlock_bh(&todo_lock);
sta = get_sta_for_key(key);
sdata = key->sdata;
@@ -191,9 +126,7 @@
wiphy_name(key->local->hw.wiphy),
key->conf.keyidx, sta ? sta->addr : bcast_addr, ret);
- spin_lock_bh(&todo_lock);
key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
- spin_unlock_bh(&todo_lock);
}
static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
@@ -201,22 +134,24 @@
{
struct ieee80211_key *key = NULL;
+ assert_key_lock(sdata->local);
+
if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
key = sdata->keys[idx];
rcu_assign_pointer(sdata->default_key, key);
- if (key)
- add_todo(key, KEY_FLAG_TODO_DEFKEY);
+ if (key) {
+ ieee80211_debugfs_key_remove_default(key->sdata);
+ ieee80211_debugfs_key_add_default(key->sdata);
+ }
}
void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx)
{
- unsigned long flags;
-
- spin_lock_irqsave(&sdata->local->key_lock, flags);
+ mutex_lock(&sdata->local->key_mtx);
__ieee80211_set_default_key(sdata, idx);
- spin_unlock_irqrestore(&sdata->local->key_lock, flags);
+ mutex_unlock(&sdata->local->key_mtx);
}
static void
@@ -224,24 +159,26 @@
{
struct ieee80211_key *key = NULL;
+ assert_key_lock(sdata->local);
+
if (idx >= NUM_DEFAULT_KEYS &&
idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
key = sdata->keys[idx];
rcu_assign_pointer(sdata->default_mgmt_key, key);
- if (key)
- add_todo(key, KEY_FLAG_TODO_DEFMGMTKEY);
+ if (key) {
+ ieee80211_debugfs_key_remove_mgmt_default(key->sdata);
+ ieee80211_debugfs_key_add_mgmt_default(key->sdata);
+ }
}
void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
int idx)
{
- unsigned long flags;
-
- spin_lock_irqsave(&sdata->local->key_lock, flags);
+ mutex_lock(&sdata->local->key_mtx);
__ieee80211_set_default_mgmt_key(sdata, idx);
- spin_unlock_irqrestore(&sdata->local->key_lock, flags);
+ mutex_unlock(&sdata->local->key_mtx);
}
@@ -352,7 +289,6 @@
}
memcpy(key->conf.key, key_data, key_len);
INIT_LIST_HEAD(&key->list);
- INIT_LIST_HEAD(&key->todo);
if (alg == ALG_CCMP) {
/*
@@ -382,12 +318,27 @@
return key;
}
+static void __ieee80211_key_destroy(struct ieee80211_key *key)
+{
+ if (!key)
+ return;
+
+ ieee80211_key_disable_hw_accel(key);
+
+ if (key->conf.alg == ALG_CCMP)
+ ieee80211_aes_key_free(key->u.ccmp.tfm);
+ if (key->conf.alg == ALG_AES_CMAC)
+ ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
+ ieee80211_debugfs_key_remove(key);
+
+ kfree(key);
+}
+
void ieee80211_key_link(struct ieee80211_key *key,
struct ieee80211_sub_if_data *sdata,
struct sta_info *sta)
{
struct ieee80211_key *old_key;
- unsigned long flags;
int idx;
BUG_ON(!sdata);
@@ -431,7 +382,7 @@
}
}
- spin_lock_irqsave(&sdata->local->key_lock, flags);
+ mutex_lock(&sdata->local->key_mtx);
if (sta)
old_key = sta->key;
@@ -439,15 +390,13 @@
old_key = sdata->keys[idx];
__ieee80211_key_replace(sdata, sta, old_key, key);
+ __ieee80211_key_destroy(old_key);
- /* free old key later */
- add_todo(old_key, KEY_FLAG_TODO_DELETE);
+ ieee80211_debugfs_key_add(key);
- add_todo(key, KEY_FLAG_TODO_ADD_DEBUGFS);
- if (ieee80211_sdata_running(sdata))
- add_todo(key, KEY_FLAG_TODO_HWACCEL_ADD);
+ ieee80211_key_enable_hw_accel(key);
- spin_unlock_irqrestore(&sdata->local->key_lock, flags);
+ mutex_unlock(&sdata->local->key_mtx);
}
static void __ieee80211_key_free(struct ieee80211_key *key)
@@ -458,170 +407,65 @@
if (key->sdata)
__ieee80211_key_replace(key->sdata, key->sta,
key, NULL);
-
- add_todo(key, KEY_FLAG_TODO_DELETE);
+ __ieee80211_key_destroy(key);
}
void ieee80211_key_free(struct ieee80211_key *key)
{
- unsigned long flags;
+ struct ieee80211_local *local;
if (!key)
return;
- if (!key->sdata) {
- /* The key has not been linked yet, simply free it
- * and don't Oops */
- if (key->conf.alg == ALG_CCMP)
- ieee80211_aes_key_free(key->u.ccmp.tfm);
- kfree(key);
- return;
- }
+ local = key->sdata->local;
- spin_lock_irqsave(&key->sdata->local->key_lock, flags);
+ mutex_lock(&local->key_mtx);
__ieee80211_key_free(key);
- spin_unlock_irqrestore(&key->sdata->local->key_lock, flags);
-}
-
-/*
- * To be safe against concurrent manipulations of the list (which shouldn't
- * actually happen) we need to hold the spinlock. But under the spinlock we
- * can't actually do much, so we defer processing to the todo list. Then run
- * the todo list to be sure the operation and possibly previously pending
- * operations are completed.
- */
-static void ieee80211_todo_for_each_key(struct ieee80211_sub_if_data *sdata,
- u32 todo_flags)
-{
- struct ieee80211_key *key;
- unsigned long flags;
-
- might_sleep();
-
- spin_lock_irqsave(&sdata->local->key_lock, flags);
- list_for_each_entry(key, &sdata->key_list, list)
- add_todo(key, todo_flags);
- spin_unlock_irqrestore(&sdata->local->key_lock, flags);
-
- ieee80211_key_todo();
+ mutex_unlock(&local->key_mtx);
}
void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
{
+ struct ieee80211_key *key;
+
ASSERT_RTNL();
if (WARN_ON(!ieee80211_sdata_running(sdata)))
return;
- ieee80211_todo_for_each_key(sdata, KEY_FLAG_TODO_HWACCEL_ADD);
+ mutex_lock(&sdata->local->key_mtx);
+
+ list_for_each_entry(key, &sdata->key_list, list)
+ ieee80211_key_enable_hw_accel(key);
+
+ mutex_unlock(&sdata->local->key_mtx);
}
void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata)
{
+ struct ieee80211_key *key;
+
ASSERT_RTNL();
- ieee80211_todo_for_each_key(sdata, KEY_FLAG_TODO_HWACCEL_REMOVE);
-}
+ mutex_lock(&sdata->local->key_mtx);
-static void __ieee80211_key_destroy(struct ieee80211_key *key)
-{
- if (!key)
- return;
+ list_for_each_entry(key, &sdata->key_list, list)
+ ieee80211_key_disable_hw_accel(key);
- ieee80211_key_disable_hw_accel(key);
-
- if (key->conf.alg == ALG_CCMP)
- ieee80211_aes_key_free(key->u.ccmp.tfm);
- if (key->conf.alg == ALG_AES_CMAC)
- ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
- ieee80211_debugfs_key_remove(key);
-
- kfree(key);
-}
-
-static void __ieee80211_key_todo(void)
-{
- struct ieee80211_key *key;
- bool work_done;
- u32 todoflags;
-
- /*
- * NB: sta_info_destroy relies on this!
- */
- synchronize_rcu();
-
- spin_lock_bh(&todo_lock);
- while (!list_empty(&todo_list)) {
- key = list_first_entry(&todo_list, struct ieee80211_key, todo);
- list_del_init(&key->todo);
- todoflags = key->flags & (KEY_FLAG_TODO_ADD_DEBUGFS |
- KEY_FLAG_TODO_DEFKEY |
- KEY_FLAG_TODO_DEFMGMTKEY |
- KEY_FLAG_TODO_HWACCEL_ADD |
- KEY_FLAG_TODO_HWACCEL_REMOVE |
- KEY_FLAG_TODO_DELETE);
- key->flags &= ~todoflags;
- spin_unlock_bh(&todo_lock);
-
- work_done = false;
-
- if (todoflags & KEY_FLAG_TODO_ADD_DEBUGFS) {
- ieee80211_debugfs_key_add(key);
- work_done = true;
- }
- if (todoflags & KEY_FLAG_TODO_DEFKEY) {
- ieee80211_debugfs_key_remove_default(key->sdata);
- ieee80211_debugfs_key_add_default(key->sdata);
- work_done = true;
- }
- if (todoflags & KEY_FLAG_TODO_DEFMGMTKEY) {
- ieee80211_debugfs_key_remove_mgmt_default(key->sdata);
- ieee80211_debugfs_key_add_mgmt_default(key->sdata);
- work_done = true;
- }
- if (todoflags & KEY_FLAG_TODO_HWACCEL_ADD) {
- ieee80211_key_enable_hw_accel(key);
- work_done = true;
- }
- if (todoflags & KEY_FLAG_TODO_HWACCEL_REMOVE) {
- ieee80211_key_disable_hw_accel(key);
- work_done = true;
- }
- if (todoflags & KEY_FLAG_TODO_DELETE) {
- __ieee80211_key_destroy(key);
- work_done = true;
- }
-
- WARN_ON(!work_done);
-
- spin_lock_bh(&todo_lock);
- }
- spin_unlock_bh(&todo_lock);
-}
-
-void ieee80211_key_todo(void)
-{
- ieee80211_key_lock();
- __ieee80211_key_todo();
- ieee80211_key_unlock();
+ mutex_unlock(&sdata->local->key_mtx);
}
void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_key *key, *tmp;
- unsigned long flags;
- ieee80211_key_lock();
+ mutex_lock(&sdata->local->key_mtx);
ieee80211_debugfs_key_remove_default(sdata);
ieee80211_debugfs_key_remove_mgmt_default(sdata);
- spin_lock_irqsave(&sdata->local->key_lock, flags);
list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
__ieee80211_key_free(key);
- spin_unlock_irqrestore(&sdata->local->key_lock, flags);
- __ieee80211_key_todo();
-
- ieee80211_key_unlock();
+ mutex_unlock(&sdata->local->key_mtx);
}
diff --git a/net/mac80211/key.h b/net/mac80211/key.h
index bdc2968..9996e3b 100644
--- a/net/mac80211/key.h
+++ b/net/mac80211/key.h
@@ -38,25 +38,9 @@
*
* @KEY_FLAG_UPLOADED_TO_HARDWARE: Indicates that this key is present
* in the hardware for TX crypto hardware acceleration.
- * @KEY_FLAG_TODO_DELETE: Key is marked for deletion and will, after an
- * RCU grace period, no longer be reachable other than from the
- * todo list.
- * @KEY_FLAG_TODO_HWACCEL_ADD: Key needs to be added to hardware acceleration.
- * @KEY_FLAG_TODO_HWACCEL_REMOVE: Key needs to be removed from hardware
- * acceleration.
- * @KEY_FLAG_TODO_DEFKEY: Key is default key and debugfs needs to be updated.
- * @KEY_FLAG_TODO_ADD_DEBUGFS: Key needs to be added to debugfs.
- * @KEY_FLAG_TODO_DEFMGMTKEY: Key is default management key and debugfs needs
- * to be updated.
*/
enum ieee80211_internal_key_flags {
KEY_FLAG_UPLOADED_TO_HARDWARE = BIT(0),
- KEY_FLAG_TODO_DELETE = BIT(1),
- KEY_FLAG_TODO_HWACCEL_ADD = BIT(2),
- KEY_FLAG_TODO_HWACCEL_REMOVE = BIT(3),
- KEY_FLAG_TODO_DEFKEY = BIT(4),
- KEY_FLAG_TODO_ADD_DEBUGFS = BIT(5),
- KEY_FLAG_TODO_DEFMGMTKEY = BIT(6),
};
enum ieee80211_internal_tkip_state {
@@ -79,10 +63,8 @@
/* for sdata list */
struct list_head list;
- /* for todo list */
- struct list_head todo;
- /* protected by todo lock! */
+ /* protected by key mutex */
unsigned int flags;
union {
@@ -155,6 +137,4 @@
void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata);
void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata);
-void ieee80211_key_todo(void);
-
#endif /* IEEE80211_KEY_H */
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 4051b23..045ead9 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -448,7 +448,7 @@
mutex_init(&local->iflist_mtx);
mutex_init(&local->scan_mtx);
- spin_lock_init(&local->key_lock);
+ mutex_init(&local->key_mtx);
spin_lock_init(&local->filter_lock);
spin_lock_init(&local->queue_stop_reason_lock);
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 7301975..c426c57 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -648,14 +648,6 @@
if (sta->key) {
ieee80211_key_free(sta->key);
- /*
- * We have only unlinked the key, and actually destroying it
- * may mean it is removed from hardware which requires that
- * the key->sta pointer is still valid, so flush the key todo
- * list here.
- */
- ieee80211_key_todo();
-
WARN_ON(sta->key);
}