mac80211: fix spinlock recursion

When STAs are expired, we need to hold the sta_lock. Using
the same lock for keys too would then mean we'd need another
key free function, and that'll just lead to confusion, so just
use a new spinlock for all key lists.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index c642538e8282c88c5676d56e8c83a7b515bca5b1..ce566f3e0169a9e62f2b458c698753a543a25626 100644 (file)
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -600,8 +600,7 @@ struct ieee80211_local {
        /*
         * The lock only protects the list, hash, timer and counter
         * against manipulation, reads are done in RCU. Additionally,
-        * the lock protects each BSS's TIM bitmap, a few items in
-        * STA info structures and various key pointers.
+        * the lock protects each BSS's TIM bitmap.
         */
        spinlock_t sta_lock;
        unsigned long num_sta;
@@ -635,6 +634,13 @@ struct ieee80211_local {
 
        struct list_head interfaces;
 
+       /*
+        * Key lock, protects sdata's key_list and sta_info's
+        * key pointers (write access, they're RCU.)
+        */
+       spinlock_t key_lock;
+
+
        bool sta_sw_scanning;
        bool sta_hw_scanning;
        int scan_channel_idx;

diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index acf8d0370a3716607a690580894ef5ced08e9bc4..b98711dcdc54ec5cef69036862902f9087a0ae1b 100644 (file)
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -210,9 +210,9 @@ void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx)
 {
        unsigned long flags;
 
-       spin_lock_irqsave(&sdata->local->sta_lock, flags);
+       spin_lock_irqsave(&sdata->local->key_lock, flags);
        __ieee80211_set_default_key(sdata, idx);
-       spin_unlock_irqrestore(&sdata->local->sta_lock, flags);
+       spin_unlock_irqrestore(&sdata->local->key_lock, flags);
 }
 
 
@@ -339,7 +339,7 @@ void ieee80211_key_link(struct ieee80211_key *key,
                }
        }
 
-       spin_lock_irqsave(&sdata->local->sta_lock, flags);
+       spin_lock_irqsave(&sdata->local->key_lock, flags);
 
        if (sta)
                old_key = sta->key;
@@ -348,7 +348,7 @@ void ieee80211_key_link(struct ieee80211_key *key,
 
        __ieee80211_key_replace(sdata, sta, old_key, key);
 
-       spin_unlock_irqrestore(&sdata->local->sta_lock, flags);
+       spin_unlock_irqrestore(&sdata->local->key_lock, flags);
 
        /* free old key later */
        add_todo(old_key, KEY_FLAG_TODO_DELETE);
@@ -377,9 +377,9 @@ void ieee80211_key_free(struct ieee80211_key *key)
        if (!key)
                return;
 
-       spin_lock_irqsave(&key->sdata->local->sta_lock, flags);
+       spin_lock_irqsave(&key->sdata->local->key_lock, flags);
        __ieee80211_key_free(key);
-       spin_unlock_irqrestore(&key->sdata->local->sta_lock, flags);
+       spin_unlock_irqrestore(&key->sdata->local->key_lock, flags);
 }
 
 /*
@@ -397,10 +397,10 @@ static void ieee80211_todo_for_each_key(struct ieee80211_sub_if_data *sdata,
 
        might_sleep();
 
-       spin_lock_irqsave(&sdata->local->sta_lock, flags);
+       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->sta_lock, flags);
+       spin_unlock_irqrestore(&sdata->local->key_lock, flags);
 
        ieee80211_key_todo();
 }
@@ -506,10 +506,10 @@ void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
 
        ieee80211_debugfs_key_remove_default(sdata);
 
-       spin_lock_irqsave(&sdata->local->sta_lock, flags);
+       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->sta_lock, flags);
+       spin_unlock_irqrestore(&sdata->local->key_lock, flags);
 
        __ieee80211_key_todo();
 

diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index bfcbcf5353ad815a1b14cc641ccfeea830e3a145..e9a978979d38553188163f1b632360233735a401 100644 (file)
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -1587,6 +1587,8 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
 
        INIT_LIST_HEAD(&local->interfaces);
 
+       spin_lock_init(&local->key_lock);
+
        INIT_DELAYED_WORK(&local->scan_work, ieee80211_sta_scan_work);
 
        sta_info_init(local);