From: Heiko Carstens Date: Tue, 7 Jan 2025 10:28:58 +0000 (+0100) Subject: s390/futex: Fix FUTEX_OP_ANDN implementation X-Git-Tag: v6.14-rc1~200^2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=26701574cee6777f867f89b4a5c667817e1ee0dd;p=thirdparty%2Flinux.git s390/futex: Fix FUTEX_OP_ANDN implementation 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@vger.kernel.org Signed-off-by: Heiko Carstens Acked-by: Alexander Gordeev Signed-off-by: Alexander Gordeev --- diff --git a/arch/s390/include/asm/futex.h b/arch/s390/include/asm/futex.h index eaeaeb3ff0be3..752a2310f0d6c 100644 --- a/arch/s390/include/asm/futex.h +++ b/arch/s390/include/asm/futex.h @@ -44,7 +44,7 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval, 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",