The support for __uint128_t is dependent on the target bit size. GCC that defaults to the 32-bit can still build the 64-bit kernel with -m64 flag passed. However, $(cc-option,-D__SIZEOF_INT128__=0) is evaluated against the default machine bit, which may not match to the kernel it is building. Theoretically, this could be evaluated separately for 64BIT/32BIT. config CC_HAS_INT128 bool default !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) if 64BIT default !$(cc-option,$(m32-flag) -D__SIZEOF_INT128__=0) I simplified it more because the 32-bit compiler is unlikely to support __uint128_t. Fixes: c12d3362a74b ("int128: move __uint128_t compiler test to Kconfig") Reported-by: George Spelvin <lkml@xxxxxxx> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> --- init/Kconfig | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/init/Kconfig b/init/Kconfig index 20a6ac33761c..4f717bfdbfe2 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -767,8 +767,7 @@ config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH bool config CC_HAS_INT128 - def_bool y - depends on !$(cc-option,-D__SIZEOF_INT128__=0) + def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) && 64BIT # # For architectures that know their GCC __int128 support is sound -- 2.17.1