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

["André Almeida" <andrealmeid@igalia.com>]

Em 08/07/2026 12:28, André Almeida escreveu:
> 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 <tglx@kernel.org>
>> Link: https://lore.kernel.org/lkml/20260602090536.045586688@kernel.org/
>> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
>> ---
> 
> 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 <andrealmeid@igalia.com>

Also, how do you suggest to integrate this with kselftests? Maybe adding 
an untar command to futex/functional/run.sh?