FROMGIT: kbuild: Add gendwarfksyms as an alternative to genksyms

When MODVERSIONS is enabled, allow selecting gendwarfksyms as the
implementation, but default to genksyms.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
(cherry picked from commit 9c3681f9b9fd12cdbc4a542df599f1837512f3d5
 https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git kbuild)
Bug: 347787665
Signed-off-by: Matthew Maurer <mmaurer@google.com>

Change-Id: Id6279538db7fc1616dc6a1a4b980df271e8df087
Signed-off-by: Matthew Maurer <mmaurer@google.com>

kernel/module/Kconfig

@@ -169,6 +169,22 @@ config MODVERSIONS
 	  make them incompatible with the kernel you are running.  If
 	  unsure, say N.
 
+choice
+	prompt "Module versioning implementation"
+	depends on MODVERSIONS
+	help
+	  Select the tool used to calculate symbol versions for modules.
+
+	  If unsure, select GENKSYMS.
+
+config GENKSYMS
+	bool "genksyms (from source code)"
+	help
+	  Calculate symbol versions from pre-processed source code using
+	  genksyms.
+
+	  If unsure, say Y.
+
 config GENDWARFKSYMS
 	bool "gendwarfksyms (from debugging information)"
 	depends on DEBUG_INFO
@@ -176,6 +192,12 @@ config GENDWARFKSYMS
 	depends on !DEBUG_INFO_REDUCED && !DEBUG_INFO_SPLIT
 	# Requires ELF object files.
 	depends on !LTO
+	help
+	  Calculate symbol versions from DWARF debugging information using
+	  gendwarfksyms. Requires DEBUG_INFO to be enabled.
+
+	  If unsure, say N.
+endchoice
 
 config ASM_MODVERSIONS
 	bool