diff --git a/core/modules/user/user.module b/core/modules/user/user.module
index 3da4a71..094d58e 100644
--- a/core/modules/user/user.module
+++ b/core/modules/user/user.module
@@ -422,37 +422,7 @@ function user_password($length = 10) {
  *   permission strings for the given role ID.
  */
 function user_role_permissions($roles) {
-  $cache = &drupal_static(__FUNCTION__, array());
-
-  $role_permissions = $fetch = array();
-
-  foreach ($roles as $rid => $name) {
-    if (isset($cache[$rid])) {
-      $role_permissions[$rid] = $cache[$rid];
-    }
-    else {
-      // Add this rid to the list of those needing to be fetched.
-      $fetch[] = $rid;
-      // Prepare in case no permissions are returned.
-      $cache[$rid] = array();
-    }
-  }
-
-  if ($fetch) {
-    // Get from the database permissions that were not in the static variable.
-    // Only role IDs with at least one permission assigned will return rows.
-    $result = db_query("SELECT rid, permission FROM {role_permission} WHERE rid IN (:fetch)", array(':fetch' => $fetch));
-
-    foreach ($result as $row) {
-      $cache[$row->rid][$row->permission] = TRUE;
-    }
-    foreach ($fetch as $rid) {
-      // For every rid, we know we at least assigned an empty array.
-      $role_permissions[$rid] = $cache[$rid];
-    }
-  }
-
-  return $role_permissions;
+  return \Drupal::service('user.access')->userRolePermissions($roles);
 }
 
 /**