Fix signal handing

test.sh

@@ -6,6 +6,14 @@ function INFO(){
     echo -e "\e[104m\e[97m[INFO]\e[49m\e[39m $@"
 }
 
+function dokillkill () {
+  sleep 5;
+  kill -9 ${1}
+  return ${?}
+}
+
+_e=0
+
 INFO 'Checking whether hitting docker#18180.'
 for f in $(seq 1 100);do
     taskset 0x1 java 2> /dev/null || true;
@@ -17,10 +25,27 @@ INFO 'OK. not hitting docker#18180.'
 INFO 'Checking whether sendfile(2) is killable.'
 INFO 'If the container hangs up here, you are still facing the bug that linux@296291cd tried to fix.'
 /sendfile-test &
-sleep 5
-kill -9 $!
-wait $!
-INFO 'OK. sendfile(2) is killable.'
-
-INFO 'PERFECT!'
-
+_e=${?};
+if [ ${_e} -ne 0 ]; then
+  INFO "Error(${?}) failed to run /sendfile-test in background"
+  exit ${_e}
+else
+  _bpid="${!}"
+  _dvs="$( date )"
+  dokillkill "${_bpid}" &
+  _e=${?};
+  if [ ${_e} -ne 0 ]; then
+    INFO "Error(${?}) failed to run DOKILLKILL ${_bpid} in background"
+    kill -9 ${_bpid}
+    exit ${_e};
+  else
+    _kpid=${!}
+    if wait ${_bpid}; then
+      _e=${?}
+    else
+      _e=${?}
+    fi
+    _dve="$( date )"
+    INFO "OK. sendfile(2) is killable when ( ${_dve} - ${_dvs}  => 5s ) and exit code ${_e} != 0."
+  fi
+fi