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

André Almeida <[email protected]> Wed, 8 Jul 2026 12:28:33 -0300
Newsgroups gmane.linux.kbuild.devel,gmane.linux.kernel
Message-ID <[email protected]>
Em 08/07/2026 10:56, Thomas Weißschuh escreveu:
> 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 <[email protected]>
> Link: https://lore.kernel.org/lkml/[email protected]/
> Signed-off-by: Thomas Weißschuh <[email protected]>
> ---

Thanks for your patch! Tested in arm64 (qemu) and it worked fine. I was 
just expecting that the file would be called "vdso.so.dbg", not "vdso.so".

Tested-by: André Almeida <[email protected]>