Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core/locking changes for v3.4 from Ingo Molnar

* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Simplify return logic
  futex: Cover all PI opcodes with cmpxchg enabled check

1 files changed, 23 insertions, 28 deletions

diff --git a/kernel/futex.c b/kernel/futex.c
index 1614be20173d..72efa1e4359a 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2628,7 +2628,7 @@ void exit_robust_list(struct task_struct *curr)
 long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
                 u32 __user *uaddr2, u32 val2, u32 val3)
 {
-        int ret = -ENOSYS, cmd = op & FUTEX_CMD_MASK;
+        int cmd = op & FUTEX_CMD_MASK;
         unsigned int flags = 0;
 
         if (!(op & FUTEX_PRIVATE_FLAG))
@@ -2641,49 +2641,44 @@ long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
         }
 
         switch (cmd) {
+        case FUTEX_LOCK_PI:
+        case FUTEX_UNLOCK_PI:
+        case FUTEX_TRYLOCK_PI:
+        case FUTEX_WAIT_REQUEUE_PI:
+        case FUTEX_CMP_REQUEUE_PI:
+                if (!futex_cmpxchg_enabled)
+                        return -ENOSYS;
+        }
+
+        switch (cmd) {
         case FUTEX_WAIT:
                 val3 = FUTEX_BITSET_MATCH_ANY;
         case FUTEX_WAIT_BITSET:
-                ret = futex_wait(uaddr, flags, val, timeout, val3);
-                break;
+                return futex_wait(uaddr, flags, val, timeout, val3);
         case FUTEX_WAKE:
                 val3 = FUTEX_BITSET_MATCH_ANY;
         case FUTEX_WAKE_BITSET:
-                ret = futex_wake(uaddr, flags, val, val3);
-                break;
+                return futex_wake(uaddr, flags, val, val3);
         case FUTEX_REQUEUE:
-                ret = futex_requeue(uaddr, flags, uaddr2, val, val2, NULL, 0);
-                break;
+                return futex_requeue(uaddr, flags, uaddr2, val, val2, NULL, 0);
         case FUTEX_CMP_REQUEUE:
-                ret = futex_requeue(uaddr, flags, uaddr2, val, val2, &val3, 0);
-                break;
+                return futex_requeue(uaddr, flags, uaddr2, val, val2, &val3, 0);
         case FUTEX_WAKE_OP:
-                ret = futex_wake_op(uaddr, flags, uaddr2, val, val2, val3);
-                break;
+                return futex_wake_op(uaddr, flags, uaddr2, val, val2, val3);
         case FUTEX_LOCK_PI:
-                if (futex_cmpxchg_enabled)
-                        ret = futex_lock_pi(uaddr, flags, val, timeout, 0);
-                break;
+                return futex_lock_pi(uaddr, flags, val, timeout, 0);
         case FUTEX_UNLOCK_PI:
-                if (futex_cmpxchg_enabled)
-                        ret = futex_unlock_pi(uaddr, flags);
-                break;
+                return futex_unlock_pi(uaddr, flags);
         case FUTEX_TRYLOCK_PI:
-                if (futex_cmpxchg_enabled)
-                        ret = futex_lock_pi(uaddr, flags, 0, timeout, 1);
-                break;
+                return futex_lock_pi(uaddr, flags, 0, timeout, 1);
         case FUTEX_WAIT_REQUEUE_PI:
                 val3 = FUTEX_BITSET_MATCH_ANY;
-                ret = futex_wait_requeue_pi(uaddr, flags, val, timeout, val3,
-                                            uaddr2);
-                break;
+                return futex_wait_requeue_pi(uaddr, flags, val, timeout, val3,
+                                             uaddr2);
         case FUTEX_CMP_REQUEUE_PI:
-                ret = futex_requeue(uaddr, flags, uaddr2, val, val2, &val3, 1);
-                break;
-        default:
-                ret = -ENOSYS;
+                return futex_requeue(uaddr, flags, uaddr2, val, val2, &val3, 1);
         }
-        return ret;
+        return -ENOSYS;
 }