From: Heiko Carstens <hca@xxxxxxxxxxxxx>
commit 26701574cee6777f867f89b4a5c667817e1ee0dd upstream.
The futex operation FUTEX_OP_ANDN is supposed to implement
*(int *)UADDR2 &= ~OPARG;
The s390 implementation just implements an AND instead of ANDN.
Add the missing bitwise not operation to oparg to fix this.
This is broken since nearly 19 years, so it looks like user space is
not making use of this operation.
Fixes: 3363fbdd6fb4 ("[PATCH] s390: futex atomic operations")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Acked-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/s390/include/asm/futex.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/s390/include/asm/futex.h
+++ b/arch/s390/include/asm/futex.h
@@ -46,7 +46,7 @@ static inline int arch_futex_atomic_op_i
break;
case FUTEX_OP_ANDN:
__futex_atomic_op("lr %2,%1\nnr %2,%5\n",
- ret, oldval, newval, uaddr, oparg);
+ ret, oldval, newval, uaddr, ~oparg);
break;
case FUTEX_OP_XOR:
__futex_atomic_op("lr %2,%1\nxr %2,%5\n",
Patches currently in stable-queue which might be from hca@xxxxxxxxxxxxx are
queue-5.4/s390-futex-fix-futex_op_andn-implementation.patch
