From: Thomas Weißschuh Date: Fri, 14 Nov 2025 13:43:58 +0000 (+0100) Subject: kbuild: allow architectures to override CC_CAN_LINK X-Git-Url: https://gentwo.org/gitweb/?a=commitdiff_plain;h=deab487e0f9b39ae4603e22d7d00908ebfc9753c;p=linux%2F.git kbuild: allow architectures to override CC_CAN_LINK 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 --- diff --git a/Makefile b/Makefile index 96ca0f17d158..63f16b160668 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 7b722e714d5c..4a2ae3cfbf26 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))