1 files changed, 25 insertions, 20 deletions

diff --git a/kernel/futex.c b/kernel/futex.c
index 93ef30ba209f..95989a3b4168 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -282,9 +282,9 @@ static inline int get_futex_value_locked(u32 *dest, u32 __user *from)
 {
         int ret;
 
-        inc_preempt_count();
+        pagefault_disable();
         ret = __copy_from_user_inatomic(dest, from, sizeof(u32));
-        dec_preempt_count();
+        pagefault_enable();
 
         return ret ? -EFAULT : 0;
 }
@@ -324,12 +324,11 @@ static int refill_pi_state_cache(void)
         if (likely(current->pi_state_cache))
                 return 0;
 
-        pi_state = kmalloc(sizeof(*pi_state), GFP_KERNEL);
+        pi_state = kzalloc(sizeof(*pi_state), GFP_KERNEL);
 
         if (!pi_state)
                 return -ENOMEM;
 
-        memset(pi_state, 0, sizeof(*pi_state));
         INIT_LIST_HEAD(&pi_state->list);
         /* pi_mutex gets initialized later */
         pi_state->owner = NULL;
@@ -553,7 +552,7 @@ static void wake_futex(struct futex_q *q)
          * at the end of wake_up_all() does not prevent this store from
          * moving.
          */
-        wmb();
+        smp_wmb();
         q->lock_ptr = NULL;
 }
 
@@ -585,9 +584,9 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this)
         if (!(uval & FUTEX_OWNER_DIED)) {
                 newval = FUTEX_WAITERS | new_owner->pid;
 
-                inc_preempt_count();
+                pagefault_disable();
                 curval = futex_atomic_cmpxchg_inatomic(uaddr, uval, newval);
-                dec_preempt_count();
+                pagefault_enable();
                 if (curval == -EFAULT)
                         return -EFAULT;
                 if (curval != uval)
@@ -618,9 +617,9 @@ static int unlock_futex_pi(u32 __user *uaddr, u32 uval)
          * There is no waiter, so we unlock the futex. The owner died
          * bit has not to be preserved here. We are the owner:
          */
-        inc_preempt_count();
+        pagefault_disable();
         oldval = futex_atomic_cmpxchg_inatomic(uaddr, uval, 0);
-        dec_preempt_count();
+        pagefault_enable();
 
         if (oldval == -EFAULT)
                 return oldval;
@@ -1158,9 +1157,9 @@ static int futex_lock_pi(u32 __user *uaddr, int detect, unsigned long sec,
          */
         newval = current->pid;
 
-        inc_preempt_count();
+        pagefault_disable();
         curval = futex_atomic_cmpxchg_inatomic(uaddr, 0, newval);
-        dec_preempt_count();
+        pagefault_enable();
 
         if (unlikely(curval == -EFAULT))
                 goto uaddr_faulted;
@@ -1183,9 +1182,9 @@ static int futex_lock_pi(u32 __user *uaddr, int detect, unsigned long sec,
         uval = curval;
         newval = uval | FUTEX_WAITERS;
 
-        inc_preempt_count();
+        pagefault_disable();
         curval = futex_atomic_cmpxchg_inatomic(uaddr, uval, newval);
-        dec_preempt_count();
+        pagefault_enable();
 
         if (unlikely(curval == -EFAULT))
                 goto uaddr_faulted;
@@ -1215,10 +1214,10 @@ static int futex_lock_pi(u32 __user *uaddr, int detect, unsigned long sec,
                         newval = current->pid |
                                 FUTEX_OWNER_DIED | FUTEX_WAITERS;
 
-                        inc_preempt_count();
+                        pagefault_disable();
                         curval = futex_atomic_cmpxchg_inatomic(uaddr,
                                                                uval, newval);
-                        dec_preempt_count();
+                        pagefault_enable();
 
                         if (unlikely(curval == -EFAULT))
                                 goto uaddr_faulted;
@@ -1390,9 +1389,9 @@ retry_locked:
          * anyone else up:
          */
         if (!(uval & FUTEX_OWNER_DIED)) {
-                inc_preempt_count();
+                pagefault_disable();
                 uval = futex_atomic_cmpxchg_inatomic(uaddr, current->pid, 0);
-                dec_preempt_count();
+                pagefault_enable();
         }
 
         if (unlikely(uval == -EFAULT))
@@ -1493,7 +1492,7 @@ static unsigned int futex_poll(struct file *filp,
         return ret;
 }
 
-static struct file_operations futex_fops = {
+static const struct file_operations futex_fops = {
         .release        = futex_close,
         .poll           = futex_poll,
 };
@@ -1858,10 +1857,16 @@ static struct file_system_type futex_fs_type = {
 
 static int __init init(void)
 {
-        unsigned int i;
+        int i = register_filesystem(&futex_fs_type);
+
+        if (i)
+                return i;
 
-        register_filesystem(&futex_fs_type);
         futex_mnt = kern_mount(&futex_fs_type);
+        if (IS_ERR(futex_mnt)) {
+                unregister_filesystem(&futex_fs_type);
+                return PTR_ERR(futex_mnt);
+        }
 
         for (i = 0; i < ARRAY_SIZE(futex_queues); i++) {
                 INIT_LIST_HEAD(&futex_queues[i].chain);