wireless: convert reg_regdb_search_lock to mutex

Stanse discovered that kmalloc is being called with GFP_KERNEL while
holding this spinlock.  The spinlock can be a mutex instead, which also
enables the removal of the unlock/lock around the lock/unlock of
cfg80211_mutex and the call to set_regdom.

Reported-by: Jiri Slaby <jirislaby@gmail.com>
Cc: stable@kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 5 insertions, 7 deletions

diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index ed89c59bb431..81fcafc60150 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -324,7 +324,7 @@ struct reg_regdb_search_request {
 };
 
 static LIST_HEAD(reg_regdb_search_list);
-static DEFINE_SPINLOCK(reg_regdb_search_lock);
+static DEFINE_MUTEX(reg_regdb_search_mutex);
 
 static void reg_regdb_search(struct work_struct *work)
 {
@@ -332,7 +332,7 @@ static void reg_regdb_search(struct work_struct *work)
         const struct ieee80211_regdomain *curdom, *regdom;
         int i, r;
 
-        spin_lock(&reg_regdb_search_lock);
+        mutex_lock(&reg_regdb_search_mutex);
         while (!list_empty(&reg_regdb_search_list)) {
                 request = list_first_entry(&reg_regdb_search_list,
                                            struct reg_regdb_search_request,
@@ -346,18 +346,16 @@ static void reg_regdb_search(struct work_struct *work)
                                 r = reg_copy_regd(&regdom, curdom);
                                 if (r)
                                         break;
-                                spin_unlock(&reg_regdb_search_lock);
                                 mutex_lock(&cfg80211_mutex);
                                 set_regdom(regdom);
                                 mutex_unlock(&cfg80211_mutex);
-                                spin_lock(&reg_regdb_search_lock);
                                 break;
                         }
                 }
 
                 kfree(request);
         }
-        spin_unlock(&reg_regdb_search_lock);
+        mutex_unlock(&reg_regdb_search_mutex);
 }
 
 static DECLARE_WORK(reg_regdb_work, reg_regdb_search);
@@ -375,9 +373,9 @@ static void reg_regdb_query(const char *alpha2)
 
         memcpy(request->alpha2, alpha2, 2);
 
-        spin_lock(&reg_regdb_search_lock);
+        mutex_lock(&reg_regdb_search_mutex);
         list_add_tail(&request->list, &reg_regdb_search_list);
-        spin_unlock(&reg_regdb_search_lock);
+        mutex_unlock(&reg_regdb_search_mutex);
 
         schedule_work(&reg_regdb_work);
 }