sparc64: FUTEX_OP_ANDN fix

[ Upstream commit d72609e1 ]

Correct sparc64's implementation of FUTEX_OP_ANDN to do a
bitwise negate of the oparg parameter before applying the
AND operation. All other archs that support FUTEX_OP_ANDN
either negate oparg explicitly (frv, ia64, mips, sh, x86),
or do so indirectly by using an and-not instruction (powerpc).
Since sparc64 has and-not, I chose to use that solution.

I've not found any use of FUTEX_OP_ANDN in glibc so the
impact of this bug is probably minor. But other user-space
components may try to use it so it should still get fixed.
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

include/asm-sparc64/futex.h

@@ -59,7 +59,7 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
 		__futex_cas_op("or\t%2, %4, %1", ret, oldval, uaddr, oparg);
 		break;
 	case FUTEX_OP_ANDN:
-		__futex_cas_op("and\t%2, %4, %1", ret, oldval, uaddr, oparg);
+		__futex_cas_op("andn\t%2, %4, %1", ret, oldval, uaddr, oparg);
 		break;
 	case FUTEX_OP_XOR:
 		__futex_cas_op("xor\t%2, %4, %1", ret, oldval, uaddr, oparg);