Re: [PATCH v2 00/16] selftests: vDSO: parse_vdso: Make compatible with nolibc

[Shuah Khan <skhan@linuxfoundation.org>]

On 2/26/25 04:44, Thomas Weißschuh wrote:
> For testing the functionality of the vDSO, it is necessary to build
> userspace programs for multiple different architectures.
> It is additional work to acquire matching userspace cross-compilers with
> full C libraries and then building root images out of those.
> The kernel tree already contains nolibc, a small, header-only C library.
> By using it, it is possible to build userspace programs without any
> additional dependencies.
> For example the kernel.org crosstools or multi-target clang can be used
> to build test programs for a multitude of architectures.
> While nolibc is very limited, it is enough for many selftests.
> With some minor adjustments it is possible to make parse_vdso.c
> compatible with nolibc.
> As an example, vdso_standalone_test_x86 is now built from the same C
> code as the regular vdso_test_gettimeofday, while still being completely
> standalone.
> Also drop the dependency of parse_vdso.c on the elf.h header from libc and only
> use the one from the kernel's UAPI.
> 
> While this series is useful on its own now, it will also integrate with the
> kunit UAPI framework currently under development:
> https://lore.kernel.org/lkml/20250217-kunit-kselftests-v1-0-42b4524c3b0a@linutronix.de/
> 
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
> ---
> Changes in v2:
> - Provide a limits.h header in nolibc
> - Pick up Reviewed-by tags from Kees
> - Link to v1: https://lore.kernel.org/r/20250203-parse_vdso-nolibc-v1-0-9cb6268d77be@linutronix.de
> 
> ---
> Thomas Weißschuh (16):
>        MAINTAINERS: Add vDSO selftests
>        elf, uapi: Add definition for STN_UNDEF
>        elf, uapi: Add definition for DT_GNU_HASH
>        elf, uapi: Add definitions for VER_FLG_BASE and VER_FLG_WEAK
>        elf, uapi: Add type ElfXX_Versym
>        elf, uapi: Add types ElfXX_Verdef and ElfXX_Veraux
>        tools/include: Add uapi/linux/elf.h
>        selftests: Add headers target
>        tools/nolibc: add limits.h shim header
>        selftests: vDSO: vdso_standalone_test_x86: Use vdso_init_form_sysinfo_ehdr
>        selftests: vDSO: parse_vdso: Drop vdso_init_from_auxv()
>        selftests: vDSO: parse_vdso: Use UAPI headers instead of libc headers
>        selftests: vDSO: parse_vdso: Test __SIZEOF_LONG__ instead of ULONG_MAX
>        selftests: vDSO: vdso_test_gettimeofday: Clean up includes
>        selftests: vDSO: vdso_test_gettimeofday: Make compatible with nolibc
>        selftests: vDSO: vdso_standalone_test_x86: Switch to nolibc
> 
>   MAINTAINERS                                        |   1 +
>   include/uapi/linux/elf.h                           |  38 ++
>   tools/include/nolibc/Makefile                      |   1 +
>   tools/include/nolibc/limits.h                      |   7 +
>   tools/include/uapi/linux/elf.h                     | 524 +++++++++++++++++++++
>   tools/testing/selftests/lib.mk                     |   5 +-
>   tools/testing/selftests/vDSO/Makefile              |  11 +-
>   tools/testing/selftests/vDSO/parse_vdso.c          |  19 +-
>   tools/testing/selftests/vDSO/parse_vdso.h          |   1 -
>   .../selftests/vDSO/vdso_standalone_test_x86.c      | 143 +-----
>   .../selftests/vDSO/vdso_test_gettimeofday.c        |   4 +-
>   11 files changed, 590 insertions(+), 164 deletions(-)
> ---
> base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b
> change-id: 20241017-parse_vdso-nolibc-e069baa7ff48
> 
> Best regards,

Here is my Ack for this series to go through vDSO or x86 tree

Acked-by: Shuah Khan <skhan@linuxfoundation.org>

thanks,
-- Shuah