After commit d5c8d6e0fa61 ("kbuild: Update assembler calls to use proper flags and language target"), which updated as-instr to use the 'assembler-with-cpp' language option, the Kbuild version of as-instr always fails internally for arch/arm with
<command-line>: fatal error: asm/unified.h: No such file or directory compilation terminated.
because '-include' flags are now taken into account by the compiler driver and as-instr does not have '$(LINUXINCLUDE)', so unified.h is not found.
This went unnoticed at the time of the Kbuild change because the last use of as-instr in Kbuild that arch/arm could reach was removed in 5.7 by commit 541ad0150ca4 ("arm: Remove 32bit KVM host support") but a stable backport of the Kbuild change to before that point exposed this potential issue if one were to be reintroduced.
Follow the general pattern of '-include' paths throughout the tree and make unified.h absolute using '$(srctree)' to ensure KBUILD_AFLAGS can be used independently.
Cc: stable@vger.kernel.org Fixes: d5c8d6e0fa61 ("kbuild: Update assembler calls to use proper flags and language target") Reported-by: KernelCI bot bot@kernelci.org Closes: https://lore.kernel.org/CACo-S-1qbCX4WAVFA63dWfHtrRHZBTyyr2js8Lx=Az03XHTTHg@... Signed-off-by: Nathan Chancellor nathan@kernel.org --- arch/arm/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/Makefile b/arch/arm/Makefile index 4808d3ed98e4..e31e95ffd33f 100644 --- a/arch/arm/Makefile +++ b/arch/arm/Makefile @@ -149,7 +149,7 @@ endif # Need -Uarm for gcc < 3.x KBUILD_CPPFLAGS +=$(cpp-y) KBUILD_CFLAGS +=$(CFLAGS_ABI) $(CFLAGS_ISA) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm -KBUILD_AFLAGS +=$(CFLAGS_ABI) $(AFLAGS_ISA) -Wa,$(arch-y) $(tune-y) -include asm/unified.h -msoft-float +KBUILD_AFLAGS +=$(CFLAGS_ABI) $(AFLAGS_ISA) -Wa,$(arch-y) $(tune-y) -include $(srctree)/arch/arm/include/asm/unified.h -msoft-float KBUILD_RUSTFLAGS += --target=arm-unknown-linux-gnueabi
CHECKFLAGS += -D__arm__
--- base-commit: e04c78d86a9699d136910cfc0bdcf01087e3267e change-id: 20250618-arm-expand-include-unified-h-path-60e65adcda1e
Best regards, -- Nathan Chancellor nathan@kernel.org
On Thu, Jun 19, 2025 at 4:29 AM Nathan Chancellor nathan@kernel.org wrote:
After commit d5c8d6e0fa61 ("kbuild: Update assembler calls to use proper flags and language target"), which updated as-instr to use the 'assembler-with-cpp' language option, the Kbuild version of as-instr always fails internally for arch/arm with
<command-line>: fatal error: asm/unified.h: No such file or directory compilation terminated.
because '-include' flags are now taken into account by the compiler driver and as-instr does not have '$(LINUXINCLUDE)', so unified.h is not found.
This went unnoticed at the time of the Kbuild change because the last use of as-instr in Kbuild that arch/arm could reach was removed in 5.7 by commit 541ad0150ca4 ("arm: Remove 32bit KVM host support") but a stable backport of the Kbuild change to before that point exposed this potential issue if one were to be reintroduced.
Follow the general pattern of '-include' paths throughout the tree and make unified.h absolute using '$(srctree)' to ensure KBUILD_AFLAGS can be used independently.
Cc: stable@vger.kernel.org Fixes: d5c8d6e0fa61 ("kbuild: Update assembler calls to use proper flags and language target") Reported-by: KernelCI bot bot@kernelci.org Closes: https://lore.kernel.org/CACo-S-1qbCX4WAVFA63dWfHtrRHZBTyyr2js8Lx=Az03XHTTHg@... Signed-off-by: Nathan Chancellor nathan@kernel.org
Reviewed-by: Masahiro Yamada masahiroy@kernel.org
linux-stable-mirror@lists.linaro.org
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Masahiro Yamada -
Nathan Chancellor