Re: [PATCH] arm64: Enforce endianness build flags for LD and AS

From: Guenter Roeck
Date: Wed Oct 04 2017 - 14:31:17 EST


On Tue, Oct 03, 2017 at 01:58:22PM -0700, Guenter Roeck wrote:
> If LD or AS is specified on the command line using "make LD=<my-ld>",
> the endianness flag will not be added. Depending on the toolchain used,
> this can result in endianness mismatch errors, such as
>
> aarch64-cros-linux-gnu/binutils-bin/2.27.0/ld.bfd.real:
> arch/arm64/crypto/.tmp_aes-ce-cipher.o:
> compiled for a big endian system and target is little endian
>
> The problem was observed when using the Chrome OS build system (which sets
> LD on the command line) for an arm64:allmodconfig build.
>
> Use the override flag for both LD and AS to ensure that the endianness
> flag is always set.
>
> Cc: Douglas Anderson <dianders@xxxxxxxxxxxx>
> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>

Please ignore this patch for now; it doesn't help with my problem. Not yet
sure what happens, but it appears that "-EB" doesn't make it into the LD
variable used by cmd_make_builtin in scripts/Makefile.build. I'll have
to figure out what is going on.

Thanks,
Guenter

> ---
> arch/arm64/Makefile | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
> index 939b310913cf..d780d00bea9c 100644
> --- a/arch/arm64/Makefile
> +++ b/arch/arm64/Makefile
> @@ -56,15 +56,15 @@ KBUILD_AFLAGS += $(call cc-option,-mabi=lp64)
> ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
> KBUILD_CPPFLAGS += -mbig-endian
> CHECKFLAGS += -D__AARCH64EB__
> -AS += -EB
> -LD += -EB
> +override AS += -EB
> +override LD += -EB
> LDFLAGS += -maarch64linuxb
> UTS_MACHINE := aarch64_be
> else
> KBUILD_CPPFLAGS += -mlittle-endian
> CHECKFLAGS += -D__AARCH64EL__
> -AS += -EL
> -LD += -EL
> +override AS += -EL
> +override LD += -EL
> LDFLAGS += -maarch64linux
> UTS_MACHINE := aarch64
> endif
> --
> 2.7.4
>