test: add integration test for udev event timeout

Note that run_test() calls coredumpctl in a loop because in certain
environments (1 vCPU unaccelerated QEMU VM) it might take quite a
while to process the coredump.

test/TEST-49-UDEV-EVENT-TIMEOUT/Makefile

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

test/TEST-49-UDEV-EVENT-TIMEOUT/test.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+set -e
+
+TEST_DESCRIPTION="test udev's event-timeout and timeout-signal options"
+TEST_NO_NSPAWN=1
+. $TEST_BASE_DIR/test-functions
+
+do_test "$@" 49

test/units/testsuite-49.service

@@ -0,0 +1,6 @@
+[Unit]
+Description=TEST-49-UDEV-EVENT-TIMEOUT
+
+[Service]
+ExecStart=/usr/lib/systemd/tests/testdata/units/%N.sh
+Type=oneshot

test/units/testsuite-49.sh

@@ -0,0 +1,47 @@
+#!/usr/bin/env bash
+
+set -ex
+
+test_rule="/run/udev/rules.d/49-test.rules"
+
+setup() {
+    mkdir -p "${test_rule%/*}"
+    cp -f /etc/udev/udev.conf /etc/udev/udev.conf.bckp
+    echo 'KERNEL=="lo", SUBSYSTEM=="net", PROGRAM=="/bin/sleep 60"' > "${test_rule}"
+    echo "event_timeout=30" >> /etc/udev/udev.conf
+    echo "timeout_signal=SIGABRT" >> /etc/udev/udev.conf
+
+    systemctl restart systemd-udevd.service
+}
+
+teardown() {
+    set +e
+
+    mv -f /etc/udev/udev.conf.bckp /etc/udev/udev.conf
+    rm -f "$test_rule"
+    systemctl restart systemd-udevd.service
+}
+
+run_test() {
+    since="$(date +%T)"
+
+    echo add > /sys/class/net/lo/uevent
+
+    for n in {1..20}; do
+        sleep 5
+        if coredumpctl --since "$since" --no-legend --no-pager | grep /bin/udevadm ; then
+            return 0
+        fi
+    done
+
+    return 1
+}
+
+trap teardown EXIT
+
+setup
+run_test
+
+echo OK > /testok
+
+exit 0