xtensa: nommu: select HAVE_FUTEX_CMPXCHG

Not having HAVE_FUTEX_CMPXCHG makes futex_detect_cmpxchg probe
cmpxchg_futex_value_locked with NULL address. It's not guaranteed to
fault without MMU, instead it locks up on Xtensa when there's no RAM at
address 0.

Select HAVE_FUTEX_CMPXCHG in noMMU Xtensa configurations.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 366a98139909..3d35867c61f1 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -17,6 +17,7 @@ config XTENSA
         select HAVE_DMA_API_DEBUG
         select HAVE_DMA_ATTRS
         select HAVE_FUNCTION_TRACER
+        select HAVE_FUTEX_CMPXCHG if !MMU
         select HAVE_IRQ_TIME_ACCOUNTING
         select HAVE_OPROFILE
         select HAVE_PERF_EVENTS