Re: [PATCH] vDSO, kbuild: Provide vDSO debug variants at runtime

[Nicolas Schier]

On 2026-07-08 15:56 +0200, Thomas Weißschuh wrote:
> Finding the debug version of the vDSO is not trivial as there is no common
> scheme where it is placed. That's especially problematic for CI testing.
> 
> The vDSO futex unlock mechanism requires for testing to have access to the
> inner labels of the unlock assembly, which are only accessible via the
> debug so.
> 
> Also for general debugging purposes it's convenient to have access to the
> debug vDSO at a well defined place.
> 
> The files are placed in /sys/kernel/vdso_debug.tar.xz. They use the
> regular 'make vdso_install' layout, including build-id symlinks to find
> the correct file for each process.
> 
> The design is kept close to the ones of the similar IKCONFIG and IKHEADERS.
> 
> On x86 the x32 vDSO is derived from the x86_64 one, necessitating an
> explicit dependency to avoid errors due to concurrent builds.
> 
> Suggested-by: Thomas Gleixner <tglx@xxxxxxxxxx>
> Link: https://lore.kernel.org/lkml/20260602090536.045586688@xxxxxxxxxx/
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>
> ---
>  Makefile            | 33 ++++++++++++++++++++++++++++++++-
>  arch/x86/Makefile   |  3 +++
>  init/Kconfig        | 10 ++++++++++
>  kernel/Makefile     |  1 +
>  kernel/vdso_debug.c | 43 +++++++++++++++++++++++++++++++++++++++++++
>  5 files changed, 89 insertions(+), 1 deletion(-)
> 

This seems to have fallen through the cracks; shall it be considered for
kbuild-7.5?

-- 
Nicolas