diff -u b/core/includes/config.inc b/core/includes/config.inc
--- b/core/includes/config.inc
+++ b/core/includes/config.inc
@@ -1,6 +1,7 @@
 <?php
 
 use Drupal\Core\Config\Config;
+use Drupal\Core\Config\ConfigException;
 use Drupal\Core\Config\FileStorage;
 use Drupal\Core\Config\Context\ContextInterface;
 use Drupal\Core\Config\StorageInterface;
@@ -109,6 +110,39 @@
   return drupal_container()->get('config.factory')->get($name);
 }
 
+/*
+ * Sets the config context on the config factory.
+ *
+ * This allows configuration objects to be created using special configuration
+ * contexts eg. global override free or locale using a user preferred language.
+ * Calling this function affects all subsequent calls to config() until
+ * drupal_container()->get('config.context.factory')->leaveContext() is called.
+ *
+ * @param string $context_name
+ *   The name of the config context service on the container or a fully
+ *   qualified class implementing \Drupal\Core\Config\Context\ContextInterface.
+ *
+ * @return \Drupal\Core\Config\Context\ContextInterface
+ *   The configuration context object.
+ */
+function config_context_enter($context_name) {
+  if (drupal_container()->has($context_name)) {
+    $context = drupal_container()->get($context_name);
+  }
+  elseif (class_exists($context_name)) {
+    $context = drupal_container()
+      ->get('config.context.factory')
+      ->get($context_name);
+  }
+  else {
+    throw new ConfigException(sprintf('Unknown config context service or class: %s', $context_name));
+  }
+  drupal_container()
+    ->get('config.factory')
+    ->enterContext($context);
+  return $context;
+}
+
 /**
  * Returns a list of differences between configuration storages.
  *
diff -u b/core/lib/Drupal/Core/Config/Context/ConfigContextFactory.php b/core/lib/Drupal/Core/Config/Context/ConfigContextFactory.php
--- b/core/lib/Drupal/Core/Config/Context/ConfigContextFactory.php
+++ b/core/lib/Drupal/Core/Config/Context/ConfigContextFactory.php
@@ -8,6 +8,7 @@
 namespace Drupal\Core\Config\Context;
 
 use Drupal\Core\Config\Config;
+use Drupal\Core\Config\ConfigException;
 use Drupal\Core\Config\StorageInterface;
 use Symfony\Component\EventDispatcher\EventDispatcher;
 
@@ -56,7 +57,7 @@
       $context = new $class($this->eventDispatcher);
     }
     else {
-      throw new \Drupal\Core\Config\ConfigException(sprintf('Unknown config context class: %s', $class));
+      throw new ConfigException(sprintf('Unknown config context class: %s', $class));
     }
     return $context;
   }
diff -u b/core/modules/config/lib/Drupal/config/Tests/ConfigLocaleOverride.php b/core/modules/config/lib/Drupal/config/Tests/ConfigLocaleOverride.php
--- b/core/modules/config/lib/Drupal/config/Tests/ConfigLocaleOverride.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigLocaleOverride.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\config\Tests;
 
+use Drupal\Core\Config\ConfigException;
 use Drupal\Core\Language\Language;
 use Drupal\simpletest\DrupalUnitTestBase;
 
@@ -45,13 +46,10 @@
     $this->assertIdentical($config->get('foo'), 'en bar');
 
     // Ensure that we get the expected value when we use system_config.
-    $config_admin = system_config('config_test.system');
+    config_context_enter('config.context.free');
+    $config_admin = config('config_test.system');
     $this->assertIdentical($config_admin->get('foo'), 'bar');
 
-    // We should still be in the non override context.
-    $config = config($name);
-    $this->assertIdentical($config->get('foo'), 'bar');
-
     // Leave the non override context.
     drupal_container()->get('config.factory')->leaveContext();
     $config = config($name);
@@ -85,11 +83,10 @@
       'status' => 1,
       'preferred_langcode' => 'fr',
     ));
-
-    $user_config_context = drupal_container()->get('config.context.factory')->get('Drupal\user\UserConfigContext');
     $config_factory = drupal_container()->get('config.factory');
 
-    $config_factory->enterContext($user_config_context->setAccount($account));
+    $user_config_context = config_context_enter('Drupal\user\UserConfigContext');
+    $user_config_context->setAccount($account);
     $config = config('config_test.system');
     $this->assertIdentical($config->get('foo'), 'fr bar');
 
@@ -121,8 +118,8 @@
       'preferred_langcode' => 'en',
     ));
     // Create a new user config context to stack on top of the existign one.
-    $en_user_config_context = drupal_container()->get('config.context.factory')->get('Drupal\user\UserConfigContext');
-    $config_factory->enterContext($en_user_config_context->setAccount($account));
+    $en_user_config_context = config_context_enter('Drupal\user\UserConfigContext');
+    $en_user_config_context->setAccount($account);
     $config = config('config_test.system');
     $this->assertIdentical($config->get('foo'), 'en bar');
 
@@ -146,2 +143,15 @@
 
+  /*
+   * Tests config_context_enter() invalid context name handling.
+   */
+  function testInvalidContextName() {
+    $message = 'Expected ConfigException was thrown for an invalid context_name argument.';
+    try {
+      config_context_enter('invalid.config.context');
+      $this->fail($message);
+    }
+    catch (ConfigException $e) {
+      $this->pass($message);
+    }
+  }
 }
diff -u b/core/modules/system/system.admin.inc b/core/modules/system/system.admin.inc
--- b/core/modules/system/system.admin.inc
+++ b/core/modules/system/system.admin.inc
@@ -1403,7 +1403,8 @@
  * @see system_settings_form()
  */
 function system_site_information_settings($form, &$form_state) {
-  $site_config = system_config('system.site');
+  config_context_enter('config.context.free');
+  $site_config = config('system.site');
   $site_mail = $site_config->get('mail');
   if (empty($site_mail)) {
     $site_mail = ini_get('sendmail_from');
@@ -1509,7 +1510,8 @@
  * Form submission handler for system_site_information_settings().
  */
 function system_site_information_settings_submit($form, &$form_state) {
-  system_config('system.site')
+  config_context_enter('config.context.free');
+  config('system.site')
     ->set('name', $form_state['values']['site_name'])
     ->set('mail', $form_state['values']['site_mail'])
     ->set('slogan', $form_state['values']['site_slogan'])
@@ -1525,6 +1527,7 @@
  * @ingroup forms
  */
 function system_cron_settings($form, &$form_state) {
+  config_context_enter('config.context.free');
   $form['description'] = array(
     '#markup' => '<p>' . t('Cron takes care of running periodic tasks like checking for updates and indexing content for search.') . '</p>',
   );
@@ -1549,7 +1552,7 @@
   $form['cron']['cron_safe_threshold'] = array(
     '#type' => 'select',
     '#title' => t('Run cron every'),
-    '#default_value' => system_config('system.cron')->get('threshold.autorun'),
+    '#default_value' => config('system.cron')->get('threshold.autorun'),
     '#options' => array(0 => t('Never')) + drupal_map_assoc(array(3600, 10800, 21600, 43200, 86400, 604800), 'format_interval'),
   );
 
@@ -1562,7 +1565,8 @@
  * @ingroup forms
  */
 function system_cron_settings_submit($form, &$form_state) {
-  system_config('system.cron')
+  config_context_enter('config.context.free');
+  config('system.cron')
     ->set('threshold.autorun', $form_state['values']['cron_safe_threshold'])
     ->save();
 }
@@ -1591,10 +1595,11 @@
  * @see system_logging_settings_submit()
  */
 function system_logging_settings($form, &$form_state) {
+  config_context_enter('config.context.free');
   $form['error_level'] = array(
     '#type' => 'radios',
     '#title' => t('Error messages to display'),
-    '#default_value' => system_config('system.logging')->get('error_level'),
+    '#default_value' => config('system.logging')->get('error_level'),
     '#options' => array(
       ERROR_REPORTING_HIDE => t('None'),
       ERROR_REPORTING_DISPLAY_SOME => t('Errors and warnings'),
@@ -1613,7 +1618,8 @@
  * @ingroup forms
  */
 function system_logging_settings_submit($form, &$form_state) {
-  system_config('system.logging')
+  config_context_enter('config.context.free');
+  config('system.logging')
     ->set('error_level', $form_state['values']['error_level'])
     ->save();
 }
@@ -1626,7 +1632,8 @@
  */
 function system_performance_settings($form, &$form_state) {
   drupal_add_library('system', 'drupal.system');
-  $config = system_config('system.performance');
+  config_context_enter('config.context.free');
+  $config = config('system.performance');
 
   $form['clear_cache'] = array(
     '#type' => 'details',
@@ -1715,7 +1722,8 @@
  * @ingroup forms
  */
 function system_performance_settings_submit($form, &$form_state) {
-  $config = system_config('system.performance');
+  config_context_enter('config.context.free');
+  $config = config('system.performance');
   $config->set('cache.page.enabled', $form_state['values']['cache']);
   $config->set('cache.page.max_age', $form_state['values']['page_cache_maximum_age']);
   $config->set('response.gzip', $form_state['values']['page_compression']);
@@ -1860,7 +1868,8 @@
  * @ingroup forms
  */
 function system_rss_feeds_settings($form, &$form_state) {
-  $rss_config = system_config('system.rss');
+  config_context_enter('config.context.free');
+  $rss_config = config('system.rss');
   $form['feed_description'] = array(
     '#type' => 'textarea',
     '#title' => t('Feed description'),
@@ -1895,7 +1904,8 @@
  * @ingroup forms
  */
 function system_rss_feeds_settings_submit($form, &$form_state) {
-  system_config('system.rss')
+  config_context_enter('config.context.free');
+  config('system.rss')
     ->set('channel.description', $form_state['values']['feed_description'])
     ->set('items.limit', $form_state['values']['feed_default_items'])
     ->set('items.view_mode', $form_state['values']['feed_item_length'])
@@ -2015,7 +2025,8 @@
  * @see system_site_maintenance_mode_submit()
  */
 function system_site_maintenance_mode($form, &$form_state) {
-  $config = system_config('system.maintenance');
+  config_context_enter('config.context.free');
+  $config = config('system.maintenance');
   $form['maintenance_mode'] = array(
     '#type' => 'checkbox',
     '#title' => t('Put site into maintenance mode'),
@@ -2037,7 +2048,8 @@
  * @ingroup forms
  */
 function system_site_maintenance_mode_submit($form, &$form_state) {
-  system_config('system.maintenance')
+  config_context_enter('config.context.free');
+  config('system.maintenance')
     ->set('enabled', $form_state['values']['maintenance_mode'])
     ->set('message', $form_state['values']['maintenance_mode_message'])
     ->save();
reverted:
--- b/core/modules/system/system.module
+++ a/core/modules/system/system.module
@@ -3442,35 +3442,6 @@
 }
 
 /**
- * Retrieves a configuration object for administration.
- *
- * This configuration object will be created using a special configuration
- * context (config.admin = TRUE) and configuration plug-ins should mostly keep
- * hands off it and don't override it.
- *
- * This is intended for administration forms or any other case when we need to
- * get / set the configuration data without any overrides, as oppossed to
- * regular configuration used for runtime operations that may be altered by
- * plug-ins depending on other page request parameters:
- *
- * To get regular configuration objects for the page request use config()
- * instead of this function.
- *
- * @param $name
- *   The name of the configuration object to retrieve.
- *
- * @return Drupal\Core\Config\Config
- *   A configuration object.
- *
- * @see config()
- */
-function system_config($name) {
-  $config_factory = drupal_container()->get('config.factory');
-  $config_factory->enterContext(drupal_container()->get('config.context.free'));
-  return config($name);
-}
-
-/**
  * Generate a list of tasks offered by a specified module.
  *
  * @param $module
diff -u b/core/modules/user/user.admin.inc b/core/modules/user/user.admin.inc
--- b/core/modules/user/user.admin.inc
+++ b/core/modules/user/user.admin.inc
@@ -292,8 +292,9 @@
  * @see user_admin_settings_submit()
  */
 function user_admin_settings($form, &$form_state) {
-  $config = system_config('user.settings');
-  $mail_config = system_config('user.mail');
+  config_context_enter('config.context.free');
+  $config = config('user.settings');
+  $mail_config = config('user.mail');
 
   // Settings for anonymous users.
   $form['anonymous_settings'] = array(
@@ -627,6 +628,7 @@
  * Form submission handler for user_admin_settings().
  */
 function user_admin_settings_submit($form, &$form_state) {
+  config_context_enter('config.context.free');
   config('user.settings')
     ->set('anonymous', $form_state['values']['anonymous'])
     ->set('admin_role', $form_state['values']['user_admin_role'])
diff -u b/core/modules/user/user.module b/core/modules/user/user.module
--- b/core/modules/user/user.module
+++ b/core/modules/user/user.module
@@ -8,7 +8,6 @@
 use Drupal\user\Plugin\Core\Entity\User;
 use Drupal\user\UserRole;
 use Drupal\Core\Template\Attribute;
-use Drupal\user\UserConfigContext;
 use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 
 /**
@@ -1759,9 +1758,8 @@
 
   // Get configuration objects customized for this user, that may be localized
   // for the user's language if the locale module is enabled.
-  $config_factory = drupal_container()->get('config.factory');
-  $user_config_context = drupal_container()->get('config.context.factory')->get('Drupal\user\UserConfigContext');
-  $config_factory->enterContext($user_config_context->setAccount($params['account']));
+  $user_config_context = config_context_enter("Drupal\\user\\UserConfigContext");
+  $user_config_context->setAccount($params['account']);
   $mail_config = config('user.mail');
 
    // We do not sanitize the token replacement, since the output of this
@@ -1769,7 +1767,7 @@
   $token_options = array('langcode' => $langcode, 'callback' => 'user_mail_tokens', 'sanitize' => FALSE, 'clear' => TRUE);
   $message['subject'] .= token_replace($mail_config->get($key . '.subject'), $variables, $token_options);
   $message['body'][] = token_replace($mail_config->get($key . '.body'), $variables, $token_options);
-  $config_factory->leaveContext();
+  drupal_container()->get('config.factory')->leaveContext();
 }
 
 /**