sparc64: FUTEX_OP_ANDN fix

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>

diff --git a/arch/sparc/include/asm/futex_64.h b/arch/sparc/include/asm/futex_64.h
index d8378935ae90918149a3099b46b38e11f5aa7d42..47f95839dc6956e190cd1175cb50b74491dcab00 100644 (file)
--- a/arch/sparc/include/asm/futex_64.h
+++ b/arch/sparc/include/asm/futex_64.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);