Commit 59263b51 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

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: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Darren Hart <dvhart@linux.intel.com>
parent f07fdec5

kernel/futex.c

+13 −6
Original line number Diff line number Diff line
@@ -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;
@@ -2649,15 +2659,12 @@ 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);

		break;

	case FUTEX_UNLOCK_PI:

		if (futex_cmpxchg_enabled)

		ret = futex_unlock_pi(uaddr, flags);

		break;

	case FUTEX_TRYLOCK_PI:

		if (futex_cmpxchg_enabled)

		ret = futex_lock_pi(uaddr, flags, 0, timeout, 1);

		break;

	case FUTEX_WAIT_REQUEUE_PI: