Merge lp:~mterry/lightdm/shut-down-dbus into lp:lightdm

[Michael Terry]

Greeters like to autostart dbus by making dbus calls. This normally works fine, because such autostarted sessions are closed when X is. But since lightdm re-uses X, the dbus-daemon and its spawn were surviving login.

This branch adds a wrapper for greeter sessions that ensures everything is cleaned up correctly.

[Robert Ancell (robert-ancell)]

Ech. LightDM really doesn't know (or care) what the greeter is so doing this is making big assumptions about the greeter behaviour. All processes spawned by the greeter should be killed, but this is probably better solved using cgroups.

We should move this into the gtk-greeter / Unity greeter, as hacks are OK there, but I'd like to keep this sort of thing out of lightdm core.

review: Needs Fixing

[Robert Ancell (robert-ancell)]

I'm closing this merge request because the daemon doesn't know about what the sessions are doing and it is their responsibility to clean up.

Unmerged revisions

1069. By Michael Terry on 2011-08-24

use wrapper for greeter to ensure that dbus dies when the greeter does

=== modified file 'src/Makefile.am'
--- src/Makefile.am	2011-08-23 01:59:52 +0000
+++ src/Makefile.am	2011-08-24 19:31:24 +0000
@@ -73,6 +73,7 @@
 lightdm_CFLAGS = \
 	$(LIGHTDM_CFLAGS) \
 	$(WARN_CFLAGS) \
+	-DLIBEXEC_DIR=\"$(libexecdir)\" \
 	-DPKGLIBEXEC_DIR=\"$(pkglibexecdir)\" \
 	-DCONFIG_DIR=\"$(sysconfdir)/lightdm\" \
 	-DLOG_DIR=\"$(localstatedir)/log/lightdm\" \

=== modified file 'src/display.c'
--- src/display.c	2011-08-23 01:59:52 +0000
+++ src/display.c	2011-08-24 19:31:24 +0000
@@ -460,6 +460,12 @@
             g_free (wrapper);
         }
     }
+    else if (is_greeter)
+    {
+        gchar *t = command;
+        command = g_strdup_printf ("%s/lightdm-greeter-session '%s'", LIBEXEC_DIR, command);
+        g_free (t);
+    }
 
     session = DISPLAY_GET_CLASS (display)->create_session (display);
     g_return_val_if_fail (session != NULL, NULL);

=== modified file 'utils/Makefile.am'
--- utils/Makefile.am	2011-08-17 02:16:56 +0000
+++ utils/Makefile.am	2011-08-24 19:31:24 +0000
@@ -1,5 +1,6 @@
 bin_PROGRAMS = dm-tool
 libexec_PROGRAMS = lightdm-set-defaults
+dist_libexec_SCRIPTS = lightdm-greeter-session
 dist_pkglibexec_SCRIPTS = gdmflexiserver
 
 dm_tool_SOURCES = \

=== added file 'utils/lightdm-greeter-session'
--- utils/lightdm-greeter-session	1970-01-01 00:00:00 +0000
+++ utils/lightdm-greeter-session	2011-08-24 19:31:24 +0000
@@ -0,0 +1,36 @@
+#!/bin/sh
+# -*- Mode: sh; indent-tabs-mode: nil; tab-width: 4 -*-
+#
+# Copyright (C) 2011 Canonical Ltd
+# Author: Michael Terry <[e-mail]>
+#
+# This program is free software: you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free Software
+# Foundation, version 3 of the License.
+#
+# See http://www.gnu.org/copyleft/gpl.html the full text of the license.
+
+# This wrapper merely ensures that dbus-daemon lives only as long as this
+# script does.  Otherwise, it's very easy for dbus-daemon to be autolaunched
+# and detached from the greeter.
+
+trap cleanup TERM EXIT
+
+cleanup()
+{
+    trap - TERM EXIT
+    if [ -n "$DBUS_SESSION_BUS_PID" ]; then
+        kill "$DBUS_SESSION_BUS_PID"
+    fi
+    if [ -n "$CMD_PID" ]; then
+        kill "$CMD_PID"
+    fi
+    exit 0
+}
+
+eval `dbus-launch --sh-syntax`
+
+exec $@ &
+CMD_PID=$!
+wait $CMD_PID
+CMD_PID=