A new endpoint using the IP of the initial subflow has been recently added to increase the code coverage. But it breaks the test when using old kernels not having commit 86e39e04482b ("mptcp: keep track of local endpoint still available for each msk"), e.g. on v5.15.

Similar to commit d4c81bbb8600 ("selftests: mptcp: join: support local endpoint being tracked or not"), it is possible to add the new endpoint conditionally, by checking if "mptcp_pm_subflow_check_next" is present in kallsyms: this is not directly linked to the commit introducing this symbol but for the parent one which is linked anyway. So we can know in advance what will be the expected behaviour, and add the new endpoint only when it makes sense to do so.

Fixes: 4878f9f8421f ("selftests: mptcp: join: validate fullmesh endp on 1st sf") Cc: stable@vger.kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- tools/testing/selftests/net/mptcp/mptcp_join.sh | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh index a4762c49a878..cde041c93906 100755 --- a/tools/testing/selftests/net/mptcp/mptcp_join.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh @@ -3064,7 +3064,9 @@ fullmesh_tests() pm_nl_set_limits $ns1 1 3 pm_nl_set_limits $ns2 1 3 pm_nl_add_endpoint $ns1 10.0.2.1 flags signal - pm_nl_add_endpoint $ns2 10.0.1.2 flags subflow,fullmesh + if mptcp_lib_kallsyms_has "mptcp_pm_subflow_check_next$"; then + pm_nl_add_endpoint $ns2 10.0.1.2 flags subflow,fullmesh + fi fullmesh=1 speed=slow \ run_tests $ns1 $ns2 10.0.1.1 chk_join_nr 3 3 3