On Sat, Nov 22, 2025 at 05:23:44PM -0500, Pasha Tatashin wrote:

Subject: selftests/liveupdate: Add kexec-based selftest for

                                                         ^ for what? ;-)

Introduce a kexec-based selftest, luo_kexec_simple, to validate the
end-to-end lifecycle of a Live Update Orchestrator (LUO) session across
a reboot.

While existing tests verify the uAPI in a pre-reboot context, this test
ensures that the core functionality—preserving state via Kexec Handover
and restoring it in a new kernel—works as expected.

The test operates in two stages, managing its state across the reboot by
preserving a dedicated "state session" containing a memfd. This
mechanism dogfoods the LUO feature itself for state tracking, making the
test self-contained.

The test validates the following sequence:

Stage 1 (Pre-kexec):
 - Creates a test session (test-session).
 - Creates and preserves a memfd with a known data pattern into the test
   session.
 - Creates the state-tracking session to signal progression to Stage 2.
 - Executes a kexec reboot via a helper script.

Stage 2 (Post-kexec):
 - Retrieves the state-tracking session to confirm it is in the
   post-reboot stage.
 - Retrieves the preserved test session.
 - Restores the memfd from the test session and verifies its contents
   match the original data pattern written in Stage 1.
 - Finalizes both the test and state sessions to ensure a clean
   teardown.

The test relies on a helper script (do_kexec.sh) to perform the reboot
and a shared utility library (luo_test_utils.c) for common LUO
operations, keeping the main test logic clean and focused.

Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Zhu Yanjun <redacted>

Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>

---
 tools/testing/selftests/liveupdate/Makefile   |   6 +
 .../testing/selftests/liveupdate/do_kexec.sh  |  16 ++
 .../selftests/liveupdate/luo_kexec_simple.c   |  89 ++++++
 .../selftests/liveupdate/luo_test_utils.c     | 266 ++++++++++++++++++
 .../selftests/liveupdate/luo_test_utils.h     |  44 +++
 5 files changed, 421 insertions(+)
 create mode 100755 tools/testing/selftests/liveupdate/do_kexec.sh
 create mode 100644 tools/testing/selftests/liveupdate/luo_kexec_simple.c
 create mode 100644 tools/testing/selftests/liveupdate/luo_test_utils.c
 create mode 100644 tools/testing/selftests/liveupdate/luo_test_utils.h

-- 
Sincerely yours,
Mike.