Re: [PATCH net 6/6] selftests: mptcp: join: properly kill background tasks

Hi Matt,

On Mon, 2025-11-10 at 19:23 +0100, Matthieu Baerts (NGI0) wrote:

The 'run_tests' function is executed in the background, but killing its associated PID would not kill the children tasks running in the background.

To properly kill all background tasks, 'kill -- -PID' could be used, but this requires kill from procps-ng. Instead, all children tasks are listed using 'ps', and 'kill' is called with all PIDs of this group.

Fixes: 31ee4ad86afd ("selftests: mptcp: join: stop transfer when check is done (part 1)") Cc: stable@vger.kernel.org Fixes: 04b57c9e096a ("selftests: mptcp: join: stop transfer when check is done (part 2)") Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org

This patch looks good to me.

Reviewed-by: Geliang Tang geliang@kernel.org

Thanks, -Geliang

---

tools/testing/selftests/net/mptcp/mptcp_join.sh | 18 +++++++++------

tools/testing/selftests/net/mptcp/mptcp_lib.sh  | 21 +++++++++++++++++++++  2 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh index 01273abfdc89..41503c241989 100755 --- a/tools/testing/selftests/net/mptcp/mptcp_join.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh @@ -3831,7 +3831,7 @@ userspace_tests()   chk_mptcp_info subflows 0 subflows 0   chk_subflows_total 1 1   kill_events_pids

• mptcp_lib_kill_wait $tests_pid
  

• mptcp_lib_kill_group_wait $tests_pid
  

fi     # userspace pm create destroy subflow @@ -3859,7 +3859,7 @@ userspace_tests()   chk_mptcp_info subflows 0 subflows 0   chk_subflows_total 1 1   kill_events_pids

• mptcp_lib_kill_wait $tests_pid
  

• mptcp_lib_kill_group_wait $tests_pid
  

fi     # userspace pm create id 0 subflow @@ -3880,7 +3880,7 @@ userspace_tests()   chk_mptcp_info subflows 1 subflows 1   chk_subflows_total 2 2   kill_events_pids

• mptcp_lib_kill_wait $tests_pid
  

• mptcp_lib_kill_group_wait $tests_pid
  

fi     # userspace pm remove initial subflow @@ -3904,7 +3904,7 @@ userspace_tests()   chk_mptcp_info subflows 1 subflows 1   chk_subflows_total 1 1   kill_events_pids

• mptcp_lib_kill_wait $tests_pid
  

• mptcp_lib_kill_group_wait $tests_pid
  

fi     # userspace pm send RM_ADDR for ID 0 @@ -3930,7 +3930,7 @@ userspace_tests()   chk_mptcp_info subflows 1 subflows 1   chk_subflows_total 1 1   kill_events_pids

• mptcp_lib_kill_wait $tests_pid
  

• mptcp_lib_kill_group_wait $tests_pid
  

fi  }   @@ -3960,7 +3960,7 @@ endpoint_tests()   pm_nl_add_endpoint $ns2 10.0.2.2 flags signal   pm_nl_check_endpoint "modif is allowed" \   $ns2 10.0.2.2 id 1 flags signal

• mptcp_lib_kill_wait $tests_pid
  

• mptcp_lib_kill_group_wait $tests_pid
  

fi     if reset_with_tcp_filter "delete and re-add" ns2 10.0.3.2 REJECT OUTPUT && @@ -4015,7 +4015,7 @@ endpoint_tests()   chk_mptcp_info subflows 3 subflows 3   done

• mptcp_lib_kill_wait $tests_pid
  

• mptcp_lib_kill_group_wait $tests_pid
  

kill_events_pids   chk_evt_nr ns1 MPTCP_LIB_EVENT_LISTENER_CREATED 1 @@ -4089,7 +4089,7 @@ endpoint_tests()   wait_mpj $ns2   chk_subflow_nr "after re-re-add ID 0" 3   chk_mptcp_info subflows 3 subflows 3

• mptcp_lib_kill_wait $tests_pid
  

• mptcp_lib_kill_group_wait $tests_pid
  

kill_events_pids   chk_evt_nr ns1 MPTCP_LIB_EVENT_LISTENER_CREATED 1 @@ -4137,7 +4137,7 @@ endpoint_tests()   wait_mpj $ns2   pm_nl_add_endpoint $ns1 10.0.3.1 id 2 flags signal   wait_mpj $ns2

• mptcp_lib_kill_wait $tests_pid
  

• mptcp_lib_kill_group_wait $tests_pid
  

join_syn_tx=3 join_connect_err=1 \   chk_join_nr 2 2 2 diff --git a/tools/testing/selftests/net/mptcp/mptcp_lib.sh b/tools/testing/selftests/net/mptcp/mptcp_lib.sh index d62e653d48b0..f4388900016a 100644 --- a/tools/testing/selftests/net/mptcp/mptcp_lib.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_lib.sh @@ -350,6 +350,27 @@ mptcp_lib_kill_wait() {   wait "${1}" 2>/dev/null  }   +# $1: PID +mptcp_lib_pid_list_children() {

• local curr="${1}"
• # evoke 'ps' only once
• local pids="${2:-"$(ps o pid,ppid)"}"
• echo "${curr}"
• local pid
• for pid in $(echo "${pids}" | awk "$2 == ${curr} { print

$1 }"); do

• mptcp_lib_pid_list_children "${pid}" "${pids}"
  

• done

+}

+# $1: PID +mptcp_lib_kill_group_wait() {

• # Some users might not have procps-ng: cannot use "kill -- -

PID"

• mptcp_lib_pid_list_children "${1}" | xargs -r kill

&>/dev/null

• wait "${1}" 2>/dev/null

+}

# $1: IP address  mptcp_lib_is_v6() {   [ -z "${1##*:*}" ]