core: transition to FINAL_SIGTERM state after ExecStopPost=

Fixes #14566

src/core/service.c

@@ -3501,6 +3501,12 @@ static void service_sigchld_event(Unit *u, pid_t pid, int code, int status) {
                                 break;
 
                         case SERVICE_STOP_POST:
+
+                                if (control_pid_good(s) <= 0)
+                                        service_enter_signal(s, SERVICE_FINAL_SIGTERM, f);
+
+                                break;
+
                         case SERVICE_FINAL_SIGTERM:
                         case SERVICE_FINAL_SIGKILL:
 
@@ -3650,6 +3656,10 @@ static void service_sigchld_event(Unit *u, pid_t pid, int code, int status) {
                                 break;
 
                         case SERVICE_STOP_POST:
+                                if (main_pid_good(s) <= 0)
+                                        service_enter_signal(s, SERVICE_FINAL_SIGTERM, f);
+                                break;
+
                         case SERVICE_FINAL_SIGTERM:
                         case SERVICE_FINAL_SIGKILL:
                                 if (main_pid_good(s) <= 0)

test/TEST-47-ISSUE-14566/Makefile

@@ -0,0 +1 @@
+../TEST-01-BASIC/Makefile

test/TEST-47-ISSUE-14566/repro.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+sleep infinity &
+echo $! > /leakedtestpid
+wait $!

test/TEST-47-ISSUE-14566/test.sh

@@ -0,0 +1,43 @@
+#!/bin/bash
+set -e
+TEST_DESCRIPTION="Test that KillMode=mixed does not leave left over proccesses with ExecStopPost="
+. $TEST_BASE_DIR/test-functions
+
+test_setup() {
+    create_empty_image_rootdir
+
+    (
+        LOG_LEVEL=5
+        eval $(udevadm info --export --query=env --name=${LOOPDEV}p2)
+
+        setup_basic_environment
+        mask_supporting_services
+
+        # setup the testsuite service
+        cat >$initdir/etc/systemd/system/testsuite.service <<EOF
+[Unit]
+Description=Testsuite service
+
+[Service]
+ExecStart=/testsuite.sh
+Type=oneshot
+EOF
+        cat > $initdir/etc/systemd/system/issue_14566_test.service << EOF
+[Unit]
+Description=Issue 14566 Repro
+
+[Service]
+ExecStart=/repro.sh
+ExecStopPost=/bin/true
+KillMode=mixed
+EOF
+
+        cp testsuite.sh $initdir/
+        cp repro.sh $initdir/
+
+        setup_testsuite
+    )
+    setup_nspawn_root
+}
+
+do_test "$@"

test/TEST-47-ISSUE-14566/testsuite.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+set -ex
+set -o pipefail
+
+systemd-analyze log-level debug
+systemd-analyze log-target console
+
+systemctl start issue_14566_test
+systemctl status issue_14566_test
+
+leaked_pid=$(cat /leakedtestpid)
+
+systemctl stop issue_14566_test
+
+# Leaked PID will still be around if we're buggy.
+# I personally prefer to see 42.
+ps -p "$leaked_pid" && exit 42
+
+systemd-analyze log-level info
+
+echo OK > /testok
+
+exit 0