Changeset 4b72e81 in mainline for uspace/srv/hid/display/client.c

Timestamp:

2021-06-09T11:56:03Z (3 years ago)

Author:

Jiri Svoboda <jiri@…>

Children:

1bebc906

Parents:

4055fe63

git-author:

Jiri Svoboda <jiri@…> (2021-06-08 17:55:50)

git-committer:

Jiri Svoboda <jiri@…> (2021-06-09 11:56:03)

Message:

Purge events from client event queue when destroying window

If the client had events queued for a particular window and that got
destroyed, later these events, pointing to freed (and reused) memory
would be handed to the client with the wrong window ID (which was
read from the wrong/recycled memory block).

File:

• uspace/srv/hid/display/client.c (modified) (2 diffs)

uspace/srv/hid/display/client.c

@@ -119 +119 @@
         }
 
+        /* Make sure no event in the queue is referencing the window */
+        ds_client_purge_window_events(wnd->client, wnd);
+
         list_remove(&wnd->lcwindows);
         wnd->client = NULL;
@@ -199 +202 @@
 }
 
+/** Purge events from client event queue referring to a window.
+ *
+ * @param client Client
+ * @param window Window
+ */
+void ds_client_purge_window_events(ds_client_t *client,
+    ds_window_t *window)
+{
+        link_t *cur;
+        link_t *next;
+        ds_window_ev_t *wevent;
+
+        cur = list_first(&client->events);
+        while (cur != NULL) {
+                next = list_next(cur, &client->events);
+                wevent = list_get_instance(cur, ds_window_ev_t, levents);
+
+                if (wevent->window == window)
+                        list_remove(cur);
+
+                cur = next;
+        }
+}
+
 /** Post close event to the client's message queue.
  *