zdtm: Distinguish between fail and crash of dump

Adds a exit_signal static method to criu_cli, criu_config and criu_rpc
used to detect a crash.

Fixes: #350

Signed-off-by: Bhavik Sachdev <b.sachdev1904@gmail.com>

test/zdtm.py

@@ -899,6 +899,10 @@ def run(action,
             return cr
         return cr.wait(timeout=timeout)
 
+    @staticmethod
+    def exit_signal(ret):
+        return ret < 0
+
 
 class criu_rpc_process:
     def wait(self):
@@ -1018,8 +1022,11 @@ def run(action,
             else:
                 raise test_fail_exc('RPC for %s required' % action)
         except crpc.CRIUExceptionExternal as e:
-            print("Fail", e)
-            ret = -1
+            if e.typ != e.resp_typ:
+                ret = -2
+            else:
+                print("Fail", e)
+                ret = -1
         else:
             ret = 0
 
@@ -1032,6 +1039,10 @@ def run(action,
 
         return ret
 
+    @staticmethod
+    def exit_signal(ret):
+        return ret == -2
+
 
 class criu:
     def __init__(self, opts):
@@ -1233,7 +1244,7 @@ def __criu_act(self, action, opts=[], log=None, nowait=False):
                     return
             rst_succeeded = os.access(
                 os.path.join(__ddir, "restore-succeeded"), os.F_OK)
-            if self.__test.blocking() or (self.__sat and action == 'restore' and
+            if (self.__test.blocking() and not self.__criu.exit_signal(ret)) or (self.__sat and action == 'restore' and
                                           rst_succeeded):
                 raise test_fail_expected_exc(action)
             else:

test/zdtm/criu_config.py

@@ -40,3 +40,7 @@ def run(action,
         if nowait:
             return cr
         return cr.wait()
+
+    @staticmethod
+    def exit_signal(ret):
+        return ret < 0