Re: [PATCH v7 16/22] selftests/liveupdate: Add userspace API selftests

[Mike Rapoport]

On Sat, Nov 22, 2025 at 05:23:43PM -0500, Pasha Tatashin wrote:
> Introduce a selftest suite for LUO. These tests validate the core
> userspace-facing API provided by the /dev/liveupdate device and its
> associated ioctls.
> 
> The suite covers fundamental device behavior, session management, and
> the file preservation mechanism using memfd as a test case. This
> provides regression testing for the LUO uAPI.
> 
> The following functionality is verified:
> 
> Device Access:
>     Basic open and close operations on /dev/liveupdate.
>     Enforcement of exclusive device access (verifying EBUSY on a
>     second open).
> 
> Session Management:
>     Successful creation of sessions with unique names.
>     Failure to create sessions with duplicate names.
> 
> File Preservation:
>     Preserving a single memfd and verifying its content remains
>     intact post-preservation.
>     Preserving multiple memfds within a single session, each with
>     unique data.
>     A complex scenario involving multiple sessions, each containing
>     a mix of empty and data-filled memfds.
> 
> Note: This test suite is limited to verifying the pre-kexec
> functionality of LUO (e.g., session creation, file preservation).
> The post-kexec restoration of resources is not covered, as the kselftest
> framework does not currently support orchestrating a reboot and
> continuing execution in the new kernel.
> 
> Signed-off-by: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>

Reviewed-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>

> ---
>  MAINTAINERS                                   |   1 +
>  tools/testing/selftests/Makefile              |   1 +
>  tools/testing/selftests/liveupdate/.gitignore |   9 +
>  tools/testing/selftests/liveupdate/Makefile   |  27 ++
>  tools/testing/selftests/liveupdate/config     |  11 +
>  .../testing/selftests/liveupdate/liveupdate.c | 348 ++++++++++++++++++
>  6 files changed, 397 insertions(+)
>  create mode 100644 tools/testing/selftests/liveupdate/.gitignore
>  create mode 100644 tools/testing/selftests/liveupdate/Makefile
>  create mode 100644 tools/testing/selftests/liveupdate/config
>  create mode 100644 tools/testing/selftests/liveupdate/liveupdate.c

-- 
Sincerely yours,
Mike.