main: Add state variable splash_is_becoming_idle

Both handlers on_deactivate() and on_quit() sets the handler
on_boot_splash_idle() using the helper ply_boot_splash_become_idle().

That helper creates a new trigger and it stores it alongside the handler
in its context. The helper asserts if the trigger is set (i.e. a handler
is pending already).

None of the handlers on_deactivate() and on_quit() check if the handler
on_boot_splash_idle() is set already.

There is a race condition that leads to the situation in which the
assertion is false and causes plymouthd to signal itself with SIGABRT
and die.

First, a client sends the request deactivate to the daemon that creates
a trigger for the idle handler. Then, the trigger is still pending while
another client sends the request quit to the daemon that tries to create
a second trigger and die because of the assertion.

This commit adds the new state variable splash_is_becoming_idle that is
checked before calling the helper ply_boot_splash_become_idle() to avoid
to call it twice. The state variable is set by the caller after it calls
the helper ply_boot_splash_become_idle(). It is cleared by the handler
on_boot_splash_idle() after the splash becomes idle.

Fixes:

	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.186 ply-boot-server.c:350:print_connection_process_identity       : connection is from pid 683 (/usr/bin/plymouth deactivate) with parent pid 1 (/usr/lib/systemd/systemd --switched-root --system --deserialize 27)
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.186 ply-boot-server.c:459:ply_boot_connection_on_request          : got deactivate request
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.186 main.c:1275:on_deactivate                                     : deactivating
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.186 ply-event-loop.c:967:ply_event_loop_stop_watching_for_timeout : no matching timeout found for removal
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.186 ply-device-manager.c:1112:ply_device_manager_pause            : ply_device_manager_pause() called, stopping watching for udev events
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.186 ply-event-loop.c:761:ply_event_loop_stop_watching_fd          : stopping watching fd 8
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.186 ply-event-loop.c:777:ply_event_loop_stop_watching_fd          : removing destination for fd 8
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.186 ply-event-loop.c:786:ply_event_loop_stop_watching_fd          : no more destinations remaing for fd 8, removing source
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.186 ply-device-manager.c:1092:ply_device_manager_deactivate_keyboa: deactivating keyboards
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.186 ply-event-loop.c:761:ply_event_loop_stop_watching_fd          : stopping watching fd 10
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.186 ply-event-loop.c:777:ply_event_loop_stop_watching_fd          : removing destination for fd 10
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.186 ply-boot-splash.c:687:ply_boot_splash_become_idle             : telling splash to become idle
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.186 ./plugin.c:1801:become_idle                                   : deactivation requested
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.186 ./plugin.c:1819:become_idle                                   : already waiting for plugin to stop
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.191 ply-boot-server.c:350:print_connection_process_identity       : connection is from pid 685 (/usr/bin/plymouth quit --retain-splash) with parent pid 1 (/usr/lib/systemd/systemd --switched-root --system --deserialize 27)
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.191 ply-boot-server.c:486:ply_boot_connection_on_request          : got quit --retain-splash request
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.191 main.c:1326:on_quit                                           : quitting (retain splash: true)
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.191 main.c:1338:on_quit                                           : system initialized so saving boot-duration file
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.191 ply-utils.c:596:ply_create_directory                          : directory '/var/lib/plymouth/' already exists
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.191 main.c:686:get_cache_file_for_mode                            : returning cache file '/var/lib/plymouth//boot-duration'
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.191 ply-progress.c:214:ply_progress_save_cache                    : saving progress cache to /var/lib/plymouth//boot-duration
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.192 main.c:1634:tell_systemd_to_stop_printing_details             : telling systemd to stop printing details
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.192 main.c:1352:on_quit                                           : closing log
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.192 ply-device-manager.c:1092:ply_device_manager_deactivate_keyboa: deactivating keyboards
	Feb 25 22:04:35 steamos plymouthd[312]: 00:00:04.192 main.c:1358:on_quit                                           : unloading splash
	Feb 25 22:04:35 steamos plymouthd[312]: plymouthd: ply-boot-splash.c:677: ply_boot_splash_become_idle: Assertion `splash->idle_trigger == NULL' failed.
	Feb 25 22:05:06 steamos systemd[1]: plymouth-start.service: Main process exited, code=dumped, status=6/ABRT
	Feb 25 22:05:06 steamos systemd[1]: plymouth-start.service: Failed with result 'core-dump'.

Signed-off-by: Gaël PORTAY <gael.portay@collabora.com>

diff --git a/src/main.c b/src/main.c
index 01a7ee2db1fcce29e290639e054c2fa3797a64b1..a051f0f1b99892bf26c66b520458aa6a253cec79 100644 (file)
--- a/src/main.c
+++ b/src/main.c
@@ -108,6 +108,7 @@ typedef struct
         uint32_t                is_inactive : 1;
         uint32_t                is_shown : 1;
         uint32_t                should_force_details : 1;
+        uint32_t                splash_is_becoming_idle : 1;
 
         char                   *override_splash_path;
         char                   *system_default_splash_path;
@@ -1250,6 +1251,8 @@ on_boot_splash_idle (state_t *state)
                 ply_trace ("deactivating splash");
                 deactivate_splash (state);
         }
+
+        state->splash_is_becoming_idle = false;
 }
 
 static void
@@ -1279,10 +1282,13 @@ on_deactivate (state_t       *state,
         ply_device_manager_deactivate_keyboards (state->device_manager);
 
         if (state->boot_splash != NULL) {
-                ply_boot_splash_become_idle (state->boot_splash,
-                                             (ply_boot_splash_on_idle_handler_t)
-                                             on_boot_splash_idle,
-                                             state);
+                if (!state->splash_is_becoming_idle) {
+                        ply_boot_splash_become_idle (state->boot_splash,
+                                                     (ply_boot_splash_on_idle_handler_t)
+                                                     on_boot_splash_idle,
+                                                     state);
+                        state->splash_is_becoming_idle = true;
+                }
         } else {
                 ply_trace ("deactivating splash");
                 deactivate_splash (state);
@@ -1362,10 +1368,13 @@ on_quit (state_t       *state,
                 dump_details_and_quit_splash (state);
                 quit_program (state);
         } else if (state->boot_splash != NULL) {
-                ply_boot_splash_become_idle (state->boot_splash,
-                                             (ply_boot_splash_on_idle_handler_t)
-                                             on_boot_splash_idle,
-                                             state);
+                if (!state->splash_is_becoming_idle) {
+                        ply_boot_splash_become_idle (state->boot_splash,
+                                                     (ply_boot_splash_on_idle_handler_t)
+                                                     on_boot_splash_idle,
+                                                     state);
+                        state->splash_is_becoming_idle = true;
+                }
         } else {
                 quit_program (state);
         }