futex: Cover all PI opcodes with cmpxchg enabled check

commit 59263b513c11398cd66a52d4c5b2b118ce1e0359 upstream.

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: Peter Zijlstra <peterz@infradead.org>
Cc: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/futex.c b/kernel/futex.c
index 1614be2..0677023 100644 (file)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2641,6 +2641,16 @@ 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:
@@ -2661,16 +2671,13 @@ 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;