futex: Cover all PI opcodes with cmpxchg enabled check

Some of the newer futex PI opcodes do not check the cmpxchg enabled
variable and call unconditionally into the handling functions. Cover
all PI opcodes in a separate check.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Darren Hart <dvhart@linux.intel.com>

diff --git a/kernel/futex.c b/kernel/futex.c
index ea87f4d2f455c8c99164cb555287ad1c9fb165e3..4b1c4b6a339c5ac01c0118700f85919cd4d4b03f 100644 (file)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2628,6 +2628,16 @@ long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
                        return -ENOSYS;
        }
 
+       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;
@@ -2649,16 +2659,13 @@ long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
                ret = futex_wake_op(uaddr, flags, uaddr2, val, val2, val3);
                break;
        case FUTEX_LOCK_PI:
-               if (futex_cmpxchg_enabled)
-                       ret = futex_lock_pi(uaddr, flags, val, timeout, 0);
+               ret = futex_lock_pi(uaddr, flags, val, timeout, 0);
                break;
        case FUTEX_UNLOCK_PI:
-               if (futex_cmpxchg_enabled)
-                       ret = futex_unlock_pi(uaddr, flags);
+               ret = futex_unlock_pi(uaddr, flags);
                break;
        case FUTEX_TRYLOCK_PI:
-               if (futex_cmpxchg_enabled)
-                       ret = futex_lock_pi(uaddr, flags, 0, timeout, 1);
+               ret = futex_lock_pi(uaddr, flags, 0, timeout, 1);
                break;
        case FUTEX_WAIT_REQUEUE_PI:
                val3 = FUTEX_BITSET_MATCH_ANY;