diff --git a/core/lib/Drupal/Core/Update/UpdateKernel.php b/core/lib/Drupal/Core/Update/UpdateKernel.php
old mode 100644
new mode 100755
index 20a7275..c24688f
--- a/core/lib/Drupal/Core/Update/UpdateKernel.php
+++ b/core/lib/Drupal/Core/Update/UpdateKernel.php
@@ -20,7 +20,7 @@
  * Defines a kernel which is used primarily to run the update of Drupal.
  *
  * We use a dedicated kernel + front controller (update.php) in order to be able
- * to repair Drupal if its in a broken state.
+ * to repair Drupal if it is in a broken state.
  *
  * @see update.php
  * @see \Drupal\system\Controller\DbUpdateController
@@ -116,10 +116,9 @@ protected function shutdownSession(Request $request) {
   }
 
   /**
-   * Ensures that the request has a fake routing data for update.php.
+   * Set up the request with fake routing data for update.php.
    *
-   * This fake routing data is needed in order to make batch API working
-   * properly.
+   * This fake routing data is needed in order to make batch API work properly.
    *
    * @param \Symfony\Component\HttpFoundation\Request $request
    *   The incoming request.
@@ -136,7 +135,9 @@ protected function setupRequestMatch(Request $request) {
   }
 
   /**
-   * Checks access and throws an access, in case it is not.
+   * Checks if the current user has rights to access updates page.
+   *
+   * If the current user does not have the rights, an exception is thrown.
    *
    * @param \Symfony\Component\HttpFoundation\Request $request
    *   The incoming request.
diff --git a/update.php b/update.php
old mode 100644
new mode 100755
index 04125a3..5222b96
--- a/update.php
+++ b/update.php
@@ -1,5 +1,13 @@
 <?php
 
+/**
+ * @file
+ * The PHP page that handles updating the Drupal installation.
+ *
+ * All Drupal code is released under the GNU General Public License.
+ * See COPYRIGHT.txt and LICENSE.txt files in the "core" directory.
+ */
+
 use Drupal\Core\Update\UpdateKernel;
 use Symfony\Component\HttpFoundation\Request;