Re: [PATCH] ARM: Use an absolute path to unified.h in KBUILD_AFLAGS

[Masahiro Yamada]

On Thu, Jun 19, 2025 at 4:29 AM Nathan Chancellor <nathan@xxxxxxxxxx> 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@xxxxxxxxxxxxxxx
> Fixes: d5c8d6e0fa61 ("kbuild: Update assembler calls to use proper flags and language target")
> Reported-by: KernelCI bot <bot@xxxxxxxxxxxx>
> Closes: https://lore.kernel.org/CACo-S-1qbCX4WAVFA63dWfHtrRHZBTyyr2js8Lx=Az03XHTTHg@xxxxxxxxxxxxxx/
> Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>


Reviewed-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>





-- 
Best Regards
Masahiro Yamada