[LTP] [PATCH] fanotify: fix missing fallback for FAN_RESPONSE_ERRNO

[Petr Vorel]

Hi Andrea, all,

[ Cc fanotify developers + active LTP maintainers for CI change decision ]

Reviewed-by: Petr Vorel <pvorel@suse.cz>

Please add before merge:

Fixes: c088316452 ("fanotify24: Add test for FAN_PRE_ACCESS and FAN_DENY_ERRNO")

> From: Andrea Cervesato <andrea.cervesato@suse.com>

> Fix the following build error on i586:

> fanotify24.c: In function ‘expected_errno’:
> ..
>   173 |                 return FAN_RESPONSE_ERRNO(response);
>       |                        ^~~~~~~~~~~~~~~~~~
>       |                        FAN_DENY_ERRNO
> make[4]: *** [../../../../include/mk/rules.mk:48: fanotify24] Error 1

This is not i586 specific, it fails in our OBS also on x86_64 [1]. In fact it's
not an arch specific - it fails on all archs, e.g.: aarch64 [2] ppc64le [3].
This is actually caused by update of /usr/include/linux/fanotify.h from kernel
6.14 (in openSUSE Tumbleweed provided by linux-glibc-devel-6.14-1.1).
Please fix the commit message before merge.

And I agree that the best to avoid this in the future is to add a guard to any
definition.

@Andrea @Li @Cyril We had in the past Tumbleweed, but due internal repo problem
it sometimes failed. I wonder if it's a time trying to reintroduce it again to
catch this.  If it's not working, we might try Fedora rawhide (@Li not sure if
rawhide is generally usable for CI).

Kind regards,
Petr

[1] https://build.opensuse.org/package/live_build_log/benchmark:ltp:devel/ltp/openSUSE_Factory/x86_64
[2] https://build.opensuse.org/package/live_build_log/benchmark:ltp:devel/ltp/openSUSE_Factory_ARM/aarch64
[3] https://build.opensuse.org/package/live_build_log/benchmark:ltp:devel/ltp/openSUSE_Factory_PowerPC/ppc64le

> Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
> ---
> The reason of the fail is related to the FAN_RESPONSE_ERRNO
> definition, which is skipped in the fallback header file.

> https://openqa.opensuse.org/tests/4961163#step/install_ltp/82
> ---
>  include/lapi/fanotify.h | 3 +++
>  1 file changed, 3 insertions(+)

> diff --git a/include/lapi/fanotify.h b/include/lapi/fanotify.h
> index 76907ea5f21989c5185478d3d4f5577d9403e519..8d04c8f28969d0b3d5fec71824d569b01c9ec054 100644
> --- a/include/lapi/fanotify.h
> +++ b/include/lapi/fanotify.h
> @@ -128,6 +128,9 @@
>  #ifndef FAN_DENY_ERRNO
>  #define FAN_ERRNO(err) (((((__u32)(err)) & 0xff) << 24))
>  #define FAN_DENY_ERRNO(err) (FAN_DENY | FAN_ERRNO(err))
> +#endif
> +
> +#ifndef FAN_RESPONSE_ERRNO
>  #define FAN_RESPONSE_ERRNO(res) ((int)((res) >> 24))
>  #endif


> ---
> base-commit: 1aca297938c85b41e41c913d4ffc0ecc345d02d4
> change-id: 20250331-fix_fanotify_i586-e96ee3d06275

> Best regards,