Re: [PATCH 03/17] um: don't generate asm/bpf_perf_event.h

[Masahiro Yamada]

On Thu, Jul 4, 2024 at 11:37 PM Arnd Bergmann <arnd@xxxxxxxxxx> wrote:
>
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> If we start validating the existence of the asm-generic side of
> generated headers, this one causes a warning:
>
> make[3]: *** No rule to make target 'arch/um/include/generated/asm/bpf_perf_event.h', needed by 'all'.  Stop.
>
> The problem is that the asm-generic header only exists for the uapi
> variant, but arch/um has no uapi headers and instead uses the x86
> userspace API.
>
> Add a custom file with an explicit redirect to avoid this.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
>  arch/um/include/asm/Kbuild           | 1 -
>  arch/um/include/asm/bpf_perf_event.h | 3 +++
>  2 files changed, 3 insertions(+), 1 deletion(-)
>  create mode 100644 arch/um/include/asm/bpf_perf_event.h
>
> diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild
> index 6fe34779291a..6c583040537c 100644
> --- a/arch/um/include/asm/Kbuild
> +++ b/arch/um/include/asm/Kbuild
> @@ -1,5 +1,4 @@
>  # SPDX-License-Identifier: GPL-2.0
> -generic-y += bpf_perf_event.h
>  generic-y += bug.h
>  generic-y += compat.h
>  generic-y += current.h
> diff --git a/arch/um/include/asm/bpf_perf_event.h b/arch/um/include/asm/bpf_perf_event.h
> new file mode 100644
> index 000000000000..0a30420c83de
> --- /dev/null
> +++ b/arch/um/include/asm/bpf_perf_event.h
> @@ -0,0 +1,3 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +
> +#include <asm-generic/bpf_perf_event.h>
> --
> 2.39.2
>


I guess this is a step backward.

Technically, kernel-space asm/*.h files are allowed to
wrap UAPI <asm-generic/*.h>.
There is no reason why we ban generic-y for doing this,
whereas check-in source is allowed.




--
Best Regards
Masahiro Yamada