Merge branch 'lukas/erts/fix_init_stop_code_load_race/OTP-13802' into maint

* lukas/erts/fix_init_stop_code_load_race/OTP-13802:
  erts/kernel: Fix code loading deadlock during init:stop

3 files changed, 7 insertions, 4 deletions

diff --git a/erts/preloaded/ebin/init.beam b/erts/preloaded/ebin/init.beam
index b856bff4fe..f0344fd6ba 100644
--- a/erts/preloaded/ebin/init.beam
+++ b/erts/preloaded/ebin/init.beam
diff --git a/erts/preloaded/src/init.erl b/erts/preloaded/src/init.erl
index 45468b3b9c..67929c53c2 100644
--- a/erts/preloaded/src/init.erl
+++ b/erts/preloaded/src/init.erl
@@ -423,9 +423,6 @@ loop(State) ->
 	    Loaded = State#state.loaded, %% boot_loop but is handled here 
 	    From ! {init,Loaded},        %% anyway.
 	    loop(State);
-	{From, {ensure_loaded, _}} ->
-	    From ! {init, not_allowed},
-	    loop(State);
 	Msg ->
 	    loop(handle_msg(Msg,State))
     end.
@@ -465,6 +462,8 @@ do_handle_msg(Msg,State) ->
 		    From ! {init,ok},
 		    {new_state,State#state{subscribed = [Pid|Subscribed]}}
 	    end;
+	{From, {ensure_loaded, _}} ->
+	    From ! {init, not_allowed};
 	X ->
 	    case whereis(user) of
 		undefined ->
diff --git a/lib/kernel/src/code_server.erl b/lib/kernel/src/code_server.erl
index 1792f9e908..48541ec500 100644
--- a/lib/kernel/src/code_server.erl
+++ b/lib/kernel/src/code_server.erl
@@ -135,10 +135,14 @@ split_paths([], _S, Path, Paths) ->
 
 -spec call(term()) -> term().
 call(Req) ->
+    Ref = erlang:monitor(process, ?MODULE),
     ?MODULE ! {code_call, self(), Req},
     receive 
 	{?MODULE, Reply} ->
-	    Reply
+            erlang:demonitor(Ref,[flush]),
+	    Reply;
+        {'DOWN',Ref,process,_,_} ->
+            exit({'DOWN',code_server,Req})
     end.
 
 reply(Pid, Res) ->