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