From deab487e0f9b39ae4603e22d7d00908ebfc9753c Mon Sep 17 00:00:00 2001 From: =?utf8?q?Thomas=20Wei=C3=9Fschuh?= Date: Fri, 14 Nov 2025 14:43:58 +0100 Subject: [PATCH] kbuild: allow architectures to override CC_CAN_LINK MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The generic test for CC_CAN_LINK assumes that all architectures use -m32 and -m64 to switch between 32-bit and 64-bit compilation. This is overly simplistic. Architectures may use other flags (-mabi, -m31, etc.) or may also require byte order handling (-mlittle-endian, -EL). Expressing all of the different possibilities will be very complicated and brittle. Instead allow architectures to supply their own logic which will be easy to understand and evolve. Both the boolean ARCH_HAS_CC_CAN_LINK and the string ARCH_USERFLAGS need to be implemented as kconfig does not allow the reuse of string options. Signed-off-by: Thomas Weißschuh Reviewed-by: Nicolas Schier Reviewed-by: Nathan Chancellor Link: https://patch.msgid.link/20251114-kbuild-userprogs-bits-v3-3-4dee0d74d439@linutronix.de Signed-off-by: Nicolas Schier --- Makefile | 13 +++++++++++-- init/Kconfig | 4 ++++ 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/Makefile b/Makefile index 96ca0f17d158a..63f16b1606680 100644 --- a/Makefile +++ b/Makefile @@ -1137,8 +1137,17 @@ ifneq ($(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS),) LDFLAGS_vmlinux += --emit-relocs --discard-none endif -# Align the bit size of userspace programs with the kernel -USERFLAGS_FROM_KERNEL := -m32 -m64 --target=% +# Align the architecture of userspace programs with the kernel +USERFLAGS_FROM_KERNEL := --target=% + +ifdef CONFIG_ARCH_USERFLAGS +KBUILD_USERCFLAGS += $(CONFIG_ARCH_USERFLAGS) +KBUILD_USERLDFLAGS += $(CONFIG_ARCH_USERFLAGS) +else +# If not overridden also inherit the bit size +USERFLAGS_FROM_KERNEL += -m32 -m64 +endif + KBUILD_USERCFLAGS += $(filter $(USERFLAGS_FROM_KERNEL), $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)) KBUILD_USERLDFLAGS += $(filter $(USERFLAGS_FROM_KERNEL), $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)) diff --git a/init/Kconfig b/init/Kconfig index 7b722e714d5c5..4a2ae3cfbf265 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -82,8 +82,12 @@ config RUSTC_LLVM_VERSION int default $(rustc-llvm-version) +config ARCH_HAS_CC_CAN_LINK + bool + config CC_CAN_LINK bool + default ARCH_CC_CAN_LINK if ARCH_HAS_CC_CAN_LINK default $(cc_can_link_user,$(m64-flag)) if 64BIT default $(cc_can_link_user,$(m32-flag)) -- 2.47.3