Merge tag 'modules-for-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux

Pull modules updates from Jessica Yu:
 "The main bulk of this pull request introduces a new exported symbol
  namespaces feature. The number of exported symbols is increasingly
  growing with each release (we're at about 31k exports as of 5.3-rc7)
  and we currently have no way of visualizing how these symbols are
  "clustered" or making sense of this huge export surface.

  Namespacing exported symbols allows kernel developers to more
  explicitly partition and categorize exported symbols, as well as more
  easily limiting the availability of namespaced symbols to other parts
  of the kernel. For starters, we have introduced the USB_STORAGE
  namespace to demonstrate the API's usage. I have briefly summarized
  the feature and its main motivations in the tag below.

  Summary:

   - Introduce exported symbol namespaces.

     This new feature allows subsystem maintainers to partition and
     categorize their exported symbols into explicit namespaces. Module
     authors are now required to import the namespaces they need.

     Some of the main motivations of this feature include: allowing
     kernel developers to better manage the export surface, allow
     subsystem maintainers to explicitly state that usage of some
     exported symbols should only be limited to certain users (think:
     inter-module or inter-driver symbols, debugging symbols, etc), as
     well as more easily limiting the availability of namespaced symbols
     to other parts of the kernel.

     With the module import requirement, it is also easier to spot the
     misuse of exported symbols during patch review.

     Two new macros are introduced: EXPORT_SYMBOL_NS() and
     EXPORT_SYMBOL_NS_GPL(). The API is thoroughly documented in
     Documentation/kbuild/namespaces.rst.

   - Some small code and kbuild cleanups here and there"

* tag 'modules-for-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  module: Remove leftover '#undef' from export header
  module: remove unneeded casts in cmp_name()
  module: move CONFIG_UNUSED_SYMBOLS to the sub-menu of MODULES
  module: remove redundant 'depends on MODULES'
  module: Fix link failure due to invalid relocation on namespace offset
  usb-storage: export symbols in USB_STORAGE namespace
  usb-storage: remove single-use define for debugging
  docs: Add documentation for Symbol Namespaces
  scripts: Coccinelle script for namespace dependencies.
  modpost: add support for generating namespace dependencies
  export: allow definition default namespaces in Makefiles or sources
  module: add config option MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
  modpost: add support for symbol namespaces
  module: add support for symbol namespaces.
  export: explicitly align struct kernel_symbol
  module: support reading multiple values per modinfo tag

1 files changed, 30 insertions, 3 deletions

diff --git a/init/Kconfig b/init/Kconfig
index 058ba4e74250..57123594a7ca 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -2047,7 +2047,6 @@ config MODULE_SRCVERSION_ALL
 
 config MODULE_SIG
         bool "Module signature verification"
-        depends on MODULES
         select SYSTEM_DATA_VERIFICATION
         help
           Check modules for valid signatures upon load: the signature
@@ -2124,7 +2123,6 @@ config MODULE_SIG_HASH
 
 config MODULE_COMPRESS
         bool "Compress modules on installation"
-        depends on MODULES
         help
 
           Compresses kernel modules when 'make modules_install' is run; gzip or
@@ -2160,9 +2158,38 @@ config MODULE_COMPRESS_XZ
 
 endchoice
 
+config MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
+        bool "Allow loading of modules with missing namespace imports"
+        help
+          Symbols exported with EXPORT_SYMBOL_NS*() are considered exported in
+          a namespace. A module that makes use of a symbol exported with such a
+          namespace is required to import the namespace via MODULE_IMPORT_NS().
+          There is no technical reason to enforce correct namespace imports,
+          but it creates consistency between symbols defining namespaces and
+          users importing namespaces they make use of. This option relaxes this
+          requirement and lifts the enforcement when loading a module.
+
+          If unsure, say N.
+
+config UNUSED_SYMBOLS
+        bool "Enable unused/obsolete exported symbols"
+        default y if X86
+        help
+          Unused but exported symbols make the kernel needlessly bigger.  For
+          that reason most of these unused exports will soon be removed.  This
+          option is provided temporarily to provide a transition period in case
+          some external kernel module needs one of these symbols anyway. If you
+          encounter such a case in your module, consider if you are actually
+          using the right API.  (rationale: since nobody in the kernel is using
+          this in a module, there is a pretty good chance it's actually the
+          wrong interface to use).  If you really need the symbol, please send a
+          mail to the linux kernel mailing list mentioning the symbol and why
+          you really need it, and what the merge plan to the mainline kernel for
+          your module is.
+
 config TRIM_UNUSED_KSYMS
         bool "Trim unused exported kernel symbols"
-        depends on MODULES && !UNUSED_SYMBOLS
+        depends on !UNUSED_SYMBOLS
         help
           The kernel and some modules make many symbols available for
           other modules to use via EXPORT_SYMBOL() and variants. Depending