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 1614be20173dcb19ef45e65fa25d07f8d3c65194..06770233576249daf335a2ff050d1d8fd44af697 100644 (file)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2640,6 +2640,16 @@ 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;
@@ -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;