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>

diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 366a981..3d35867 100644 (file)
--- 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