Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/Documentation/kernel-hacking/hacking.rst b/Documentation/kernel-hacking/hacking.rst
index d824e4f..a3ddb21 100644
--- a/Documentation/kernel-hacking/hacking.rst
+++ b/Documentation/kernel-hacking/hacking.rst
@@ -594,6 +594,24 @@
 maintainers and developers may however require EXPORT_SYMBOL_GPL()
 when adding any new APIs or functionality.
 
+:c:func:`EXPORT_SYMBOL_NS()`
+----------------------------
+
+Defined in ``include/linux/export.h``
+
+This is the variant of `EXPORT_SYMBOL()` that allows specifying a symbol
+namespace. Symbol Namespaces are documented in
+``Documentation/kbuild/namespaces.rst``.
+
+:c:func:`EXPORT_SYMBOL_NS_GPL()`
+--------------------------------
+
+Defined in ``include/linux/export.h``
+
+This is the variant of `EXPORT_SYMBOL_GPL()` that allows specifying a symbol
+namespace. Symbol Namespaces are documented in
+``Documentation/kbuild/namespaces.rst``.
+
 Routines and Conventions
 ========================
 
@@ -718,7 +736,7 @@
 -  Usually you want a configuration option for your kernel hack. Edit
    ``Kconfig`` in the appropriate directory. The Config language is
    simple to use by cut and paste, and there's complete documentation in
-   ``Documentation/kbuild/kconfig-language.txt``.
+   ``Documentation/kbuild/kconfig-language.rst``.
 
    In your description of the option, make sure you address both the
    expert user and the user who knows nothing about your feature.
@@ -728,7 +746,7 @@
 
 -  Edit the ``Makefile``: the CONFIG variables are exported here so you
    can usually just add a "obj-$(CONFIG_xxx) += xxx.o" line. The syntax
-   is documented in ``Documentation/kbuild/makefiles.txt``.
+   is documented in ``Documentation/kbuild/makefiles.rst``.
 
 -  Put yourself in ``CREDITS`` if you've done something noteworthy,
    usually beyond a single file (your name should be at the top of the