selftests: mptcp: join: properly kill background tasks

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>
Link: https://patch.msgid.link/20251110-net-mptcp-sft-join-unstable-v1-6-a4332c714e10@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index 01273abfdc89789a18b1c8758f3009dc61047926..41503c241989d66919ff8f4475e2751e2300c86d 100755 (executable)
--- 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 d62e653d48b0f2ef7a01e289fa0be8907825667d..f4388900016abc642dfa2e282c81416e9e2897da 100644 (file)
--- 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##*:*}" ]