From e9ab162f30e88d5d9f8a9264d83745b8c3f381ad Mon Sep 17 00:00:00 2001
From: Colin Cross <ccross@android.com>
Date: Thu, 7 Mar 2013 13:42:29 -0800
Subject: [PATCH] init: prevent action being added to the action_queue twice

Property triggers may cause an action to be queued twice, resulting
in a loop in the action queue.  Keep actions that are not on the queue
in the list_empty state (act->qlist->next == act->qlist), and only
add them to the list if they are in that state.

Bug: 8335133
Change-Id: I3a3ec18176cf19cbaa3a45220a03c7560eacfe79
---
 init/init_parser.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/init/init_parser.c b/init/init_parser.c
index beb9188fc..686640ed4 100644
--- a/init/init_parser.c
+++ b/init/init_parser.c
@@ -571,6 +571,7 @@ void queue_builtin_action(int (*func)(int nargs, char **args), char *name)
     act = calloc(1, sizeof(*act));
     act->name = name;
     list_init(&act->commands);
+    list_init(&act->qlist);
 
     cmd = calloc(1, sizeof(*cmd));
     cmd->func = func;
@@ -583,7 +584,9 @@ void queue_builtin_action(int (*func)(int nargs, char **args), char *name)
 
 void action_add_queue_tail(struct action *act)
 {
-    list_add_tail(&action_queue, &act->qlist);
+    if (list_empty(&act->qlist)) {
+        list_add_tail(&action_queue, &act->qlist);
+    }
 }
 
 struct action *action_remove_queue_head(void)
@@ -594,6 +597,7 @@ struct action *action_remove_queue_head(void)
         struct listnode *node = list_head(&action_queue);
         struct action *act = node_to_item(node, struct action, qlist);
         list_remove(node);
+        list_init(node);
         return act;
     }
 }
@@ -825,6 +829,7 @@ static void *parse_action(struct parse_state *state, int nargs, char **args)
     act = calloc(1, sizeof(*act));
     act->name = args[1];
     list_init(&act->commands);
+    list_init(&act->qlist);
     list_add_tail(&action_list, &act->alist);
         /* XXX add to hash */
     return act;