Merge branch 'nick/ssh/fix-process-leak/OTP-8807' into dev

* nick/ssh/fix-process-leak/OTP-8807:
  Fix race condition when terminating a connection.
  fix process leak in ssh_system_sup (dynamicaly created childs where not cleaned up)

4 files changed, 49 insertions, 10 deletions

diff --git a/lib/ssh/src/ssh_cli.erl b/lib/ssh/src/ssh_cli.erl
index e3b6ffa125..cb78acb84c 100644
--- a/lib/ssh/src/ssh_cli.erl
+++ b/lib/ssh/src/ssh_cli.erl
@@ -415,14 +415,12 @@ start_shell(ConnectionManager, State) ->
     Shell = State#state.shell,
     ShellFun = case is_function(Shell) of
 		   true ->
+		       {ok, User} = 
+			   ssh_userreg:lookup_user(ConnectionManager),
 		       case erlang:fun_info(Shell, arity) of
 			   {arity, 1} ->
-			       {ok, User} = 
-				   ssh_userreg:lookup_user(ConnectionManager),
 			       fun() -> Shell(User) end;
 			   {arity, 2} ->
-			       {ok, User} = 
-				   ssh_userreg:lookup_user(ConnectionManager),
 			       {ok, PeerAddr} = 
 				   ssh_connection_manager:peer_addr(ConnectionManager),
 			       fun() -> Shell(User, PeerAddr) end;
@@ -437,10 +435,28 @@ start_shell(ConnectionManager, State) ->
     State#state{group = Group, buf = empty_buf()}.
 
 start_shell(_ConnectionManager, Cmd, #state{exec={M, F, A}} = State) ->
-    Group = group:start(self(), {M, F, A++[Cmd]}, [{echo,false}]),
+    Group = group:start(self(), {M, F, A++[Cmd]}, [{echo, false}]),
+    State#state{group = Group, buf = empty_buf()};
+start_shell(ConnectionManager, Cmd, #state{exec=Shell} = State) when is_function(Shell) ->
+    {ok, User} = 
+	ssh_userreg:lookup_user(ConnectionManager),
+    ShellFun = 
+	case erlang:fun_info(Shell, arity) of
+	    {arity, 1} ->
+		fun() -> Shell(Cmd) end;
+	    {arity, 2} ->
+		fun() -> Shell(Cmd, User) end;
+	    {arity, 3} ->
+		{ok, PeerAddr} = 
+		    ssh_connection_manager:peer_addr(ConnectionManager),
+		fun() -> Shell(Cmd, User, PeerAddr) end;
+	    _ ->
+		Shell
+	end,
+    Echo = get_echo(State#state.pty),
+    Group = group:start(self(), ShellFun, [{echo,Echo}]),
     State#state{group = Group, buf = empty_buf()}.
 
-
 % Pty can be undefined if the client never sets any pty options before
 % starting the shell.
 get_echo(undefined) ->
diff --git a/lib/ssh/src/ssh_connection_controler.erl b/lib/ssh/src/ssh_connection_controler.erl
index 636ecba532..ca3e62dc83 100644
--- a/lib/ssh/src/ssh_connection_controler.erl
+++ b/lib/ssh/src/ssh_connection_controler.erl
@@ -126,8 +126,8 @@ handle_cast(_, State) ->
 %% handle_info(ssh_connected, State) ->
 %%     {stop, normal, State};
 %% Servant termination.
-handle_info({'EXIT', _Pid, normal}, State) ->
-    {stop, normal, State}.
+handle_info({'EXIT', _Pid, Reason}, State) ->
+    {stop, Reason, State}.
 
 %%-----------------------------------------------------------------
 %% Func: code_change/3
diff --git a/lib/ssh/src/ssh_connection_manager.erl b/lib/ssh/src/ssh_connection_manager.erl
index 9e55312e5f..6bf89224cf 100644
--- a/lib/ssh/src/ssh_connection_manager.erl
+++ b/lib/ssh/src/ssh_connection_manager.erl
@@ -560,13 +560,18 @@ handle_info({'EXIT', _, _}, State) ->
 %% The return value is ignored.
 %%--------------------------------------------------------------------
 terminate(Reason, #state{connection_state =  
-			 #connection{requests = Requests},
+			 #connection{requests = Requests,
+			            sub_system_supervisor = SubSysSup},
 			 opts = Opts}) ->
     SSHOpts = proplists:get_value(ssh_opts, Opts),
     disconnect_fun(Reason, SSHOpts),
     (catch lists:foreach(fun({_, From}) -> 
 				 gen_server:reply(From, {error, connection_closed})
 			 end, Requests)),
+    Address =  proplists:get_value(address, Opts),
+    Port = proplists:get_value(port, Opts),
+    SystemSup = ssh_system_sup:system_supervisor(Address, Port),
+    ssh_system_sup:stop_subsystem(SystemSup, SubSysSup),
     ok.
 
 %%--------------------------------------------------------------------
diff --git a/lib/ssh/src/ssh_system_sup.erl b/lib/ssh/src/ssh_system_sup.erl
index 40db2e4adf..f4570b8a48 100644
--- a/lib/ssh/src/ssh_system_sup.erl
+++ b/lib/ssh/src/ssh_system_sup.erl
@@ -33,7 +33,8 @@
 	 stop_system/2, system_supervisor/2,
 	 subsystem_supervisor/1, channel_supervisor/1, 
 	 connection_supervisor/1, 
-	 acceptor_supervisor/1, start_subsystem/2, restart_subsystem/2, restart_acceptor/2]).
+	 acceptor_supervisor/1, start_subsystem/2, restart_subsystem/2,
+	 restart_acceptor/2, stop_subsystem/2]).
 
 %% Supervisor callback
 -export([init/1]).
@@ -83,6 +84,23 @@ start_subsystem(SystemSup, Options) ->
     Spec = ssh_subsystem_child_spec(Options),
     supervisor:start_child(SystemSup, Spec).
 
+stop_subsystem(SystemSup, SubSys) ->
+    case lists:keyfind(SubSys, 2, supervisor:which_children(SystemSup)) of
+	false ->
+	    {error, not_found};
+	{Id, _, _, _} ->
+	    spawn(fun() -> supervisor:terminate_child(SystemSup, Id),
+			   supervisor:delete_child(SystemSup, Id) end),
+	    ok;
+	{'EXIT', {noproc, _}} ->
+	    %% Already terminated; probably shutting down.
+	    ok;
+	{'EXIT', {shutdown, _}} ->
+	    %% Already shutting down.
+	    ok
+    end.
+
+
 restart_subsystem(Address, Port) ->
     SysSupName = make_name(Address, Port),
     SubSysName = id(ssh_subsystem_sup, Address, Port),