Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/Documentation/kernel-hacking/conf.py b/Documentation/kernel-hacking/conf.py
deleted file mode 100644
index 3d8acf0..0000000
--- a/Documentation/kernel-hacking/conf.py
+++ /dev/null
@@ -1,10 +0,0 @@
-# -*- coding: utf-8; mode: python -*-
-
-project = "Kernel Hacking Guides"
-
-tags.add("subproject")
-
-latex_documents = [
-    ('index', 'kernel-hacking.tex', project,
-     'The kernel development community', 'manual'),
-]
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
diff --git a/Documentation/kernel-hacking/locking.rst b/Documentation/kernel-hacking/locking.rst
index 519673d..a8518ac 100644
--- a/Documentation/kernel-hacking/locking.rst
+++ b/Documentation/kernel-hacking/locking.rst
@@ -451,7 +451,7 @@
             if ((obj = kmalloc(sizeof(*obj), GFP_KERNEL)) == NULL)
                     return -ENOMEM;
 
-            strlcpy(obj->name, name, sizeof(obj->name));
+            strscpy(obj->name, name, sizeof(obj->name));
             obj->id = id;
             obj->popularity = 0;
 
@@ -660,7 +660,7 @@
      }
 
     @@ -63,6 +94,7 @@
-             strlcpy(obj->name, name, sizeof(obj->name));
+             strscpy(obj->name, name, sizeof(obj->name));
              obj->id = id;
              obj->popularity = 0;
     +        obj->refcnt = 1; /* The cache holds a reference */
@@ -774,7 +774,7 @@
      }
 
     @@ -94,7 +76,7 @@
-             strlcpy(obj->name, name, sizeof(obj->name));
+             strscpy(obj->name, name, sizeof(obj->name));
              obj->id = id;
              obj->popularity = 0;
     -        obj->refcnt = 1; /* The cache holds a reference */
@@ -1364,7 +1364,7 @@
 Further reading
 ===============
 
--  ``Documentation/locking/spinlocks.txt``: Linus Torvalds' spinlocking
+-  ``Documentation/locking/spinlocks.rst``: Linus Torvalds' spinlocking
    tutorial in the kernel sources.
 
 -  Unix Systems for Modern Architectures: Symmetric Multiprocessing and