From: Tri Vo <trong@xxxxxxxxxxx> commit 2a6c7c367de82951c98a290a21156770f6f82c84 upstream x0 is not callee-saved in the PCS. So there is no need to specify -fcall-used-x0. Clang doesn't currently support -fcall-used flags. This patch will help building the kernel with clang. Tested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Acked-by: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Tri Vo <trong@xxxxxxxxxxx> Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx> Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> --- Sending to stable for inclusion in 4.14. Needed for CONFIG_ARM64_LSE_ATOMICS. arch/arm64/lib/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile index f28f91fd96a2..69ff9887f724 100644 --- a/arch/arm64/lib/Makefile +++ b/arch/arm64/lib/Makefile @@ -12,7 +12,7 @@ lib-y := clear_user.o delay.o copy_from_user.o \ # when supported by the CPU. Result and argument registers are handled # correctly, based on the function prototype. lib-$(CONFIG_ARM64_LSE_ATOMICS) += atomic_ll_sc.o -CFLAGS_atomic_ll_sc.o := -fcall-used-x0 -ffixed-x1 -ffixed-x2 \ +CFLAGS_atomic_ll_sc.o := -ffixed-x1 -ffixed-x2 \ -ffixed-x3 -ffixed-x4 -ffixed-x5 -ffixed-x6 \ -ffixed-x7 -fcall-saved-x8 -fcall-saved-x9 \ -fcall-saved-x10 -fcall-saved-x11 -fcall-saved-x12 \ -- 2.19.1.568.g152ad8e336-goog
