Re: [PATCH 01/12] kconfig: implement CONFIG_HEADERS_INSTALL for Usermode Linux

[Masahiro Yamada]

On Mon, Feb 17, 2025 at 8:00 PM Thomas Weißschuh
<thomas.weissschuh@xxxxxxxxxxxxx> wrote:
>
> userprogs sometimes need access to UAPI headers.
> This is currently not possible for Usermode Linux, as UM is only
> a pseudo architecture built on top of a regular architecture and does
> not have its own UAPI.
> Instead use the UAPI headers from the underlying regular architecture.
>
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>

Applied to linux-kbuild with the subject prefix fixed.


What concerned me was that this patch creates
multiple paths to visit the same directory.


[1]
ARCH=um archheaders
  -> ARCH=x86 archheaders
    -> arch/x86/entry/syscalls/

[2]
ARCH=um headers
  -> ARCH=x86 headers
    -> depends on ARCH=x86 archheaders
      -> arch/x86/entry/syscalls/


After carefully reviewing the code, I was convinced that
this is not a race condition.
(I am particularly cautious about race conditions in parallel builds
and try my best to avoid such code.)








--
Best Regards
Masahiro Yamada