Re: [PATCH v7 for-next 7/8] selftests/livepatch: Add test for state ID conflict across provides

[Petr Mladek <pmladek@suse.com>]

On Tue 2026-08-25 19:46:40, Yafang Shao wrote:
> Livepatches with different provides ids must not share the same state
> id. If a second livepatch attempts to reuse a state id already
> registered by a livepatch with a different provides id, the loading
> will fail. However, if the second livepatch's obsoletes list includes
> the first livepatch's provides id, the second livepatch replaces the
> first one and may reuse the same state id.
> 
> Add provides and obsoletes module parameters to test_klp_state.c and
> test_klp_state2.c (guarded by #ifndef KLP_HAS_REPLACE) so that they
> can be loaded with different provides ids and obsoletes ids.
> 
> Add a "state id conflict across provides" test scenario to
> test-provides.sh:
> 
>   - Load test_klp_state with provides=1, which registers state ID 1.
>   - Attempt to load test_klp_state2 with provides=2, which reuses the
>     same state ID 1. The second livepatch is rejected because
>     livepatches with different provides ids must not share the same
>     state id.
>   - Disable and unload the remaining livepatch.
> 
> Add a "taking over system state via obsoletes" test scenario to
> test-state.sh:
> 
>   - Load test_klp_state with provides=10, which registers state ID 1.
>   - Load test_klp_state2 with provides=20 obsoletes=10, which reuses the
>     same state ID 1. Although the provides ids differ, the second livepatch
>     replaces the first one because its obsoletes list includes the first
>     livepatch's provides id (10). The state is taken over successfully.
>   - Unload the replaced livepatch, then disable and unload the second
>     livepatch.
> 
> Assisted-by: Comagic:DeepSeek-V4-Flash
> Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
> ---
>  .../livepatch/test-provides-obsoletes.sh      | 86 +++++++++++++++++++
>  .../livepatch/test_modules/test_klp_state.c   |  9 ++
>  .../livepatch/test_modules/test_klp_state2.c  | 19 ++++
>  3 files changed, 114 insertions(+)
> 
> diff --git a/tools/testing/selftests/livepatch/test-provides-obsoletes.sh b/tools/testing/selftests/livepatch/test-provides-obsoletes.sh
> index 2707457b9133..f9a9f9b28490 100755
> --- a/tools/testing/selftests/livepatch/test-provides-obsoletes.sh
> +++ b/tools/testing/selftests/livepatch/test-provides-obsoletes.sh
> @@ -6,6 +6,8 @@
>  
>  MOD_ATOMIC=test_klp_atomic_replace
>  MOD_LIVEPATCH=test_klp_livepatch
> +MOD_STATE=test_klp_state
> +MOD_STATE2=test_klp_state2
>  
>  setup_config
>  
> @@ -171,4 +173,88 @@ livepatch: '$MOD_ATOMIC': completing unpatching transition
>  livepatch: '$MOD_ATOMIC': unpatching complete
>  % rmmod $MOD_ATOMIC"
>  
> +# - load a livepatch with provides=1 that registers state ID 1
> +# - try to load another livepatch with provides=2 that reuses the same
> +#   state ID. The second one must be rejected because livepatches with
> +#   different provides ids must not share the same state id.
> +# - disable and unload the remaining livepatch
> +
> +start_test "state id conflict across provides"
> +
> +load_lp $MOD_STATE provides=1
> +load_failing_mod $MOD_STATE2 provides=2

It is not obvious why it should fail because we do not know the used
state id. It might be better to define it via a parameter. It would
even allow to test more variants:

# same state, same provides
load_lp $MOD_STATE_LP1 state=1 provides=1
load_lp $MOD_STATE_LP2 state=1 provides=1

# same state, misc provides
load_lp $MOD_STATE_LP1 state=1 provides=1
load_failing_mod $MOD_STATE_LP2 state=1 provides=2

# same states, replaced by obsoletes
load_lp $MOD_STATE_LP1 state=1 provides=1
load_lp $MOD_STATE_LP2 state=1 provides=2 obsoletes=1

# misc states, same provides
load_lp $MOD_STATE_LP1 state=1 provides=1
load_failing_mod $MOD_STATE_LP2 state=2 provides=1

# misc states, misc provides
load_lp $MOD_STATE_LP1 state=1 provides=1
load_lp $MOD_STATE_LP2 state=2 provides=2

Best Regards,
Petr