@@ -423,6 +423,26 @@ Symbols From the Kernel (vmlinux + modules)
1) It lists all exported symbols from vmlinux and all modules.
2) It lists the CRC if CONFIG_MODVERSIONS is enabled.
+Version Information Formats
+---------------------------
+
+ Exported symbols have information stored in __ksymtab or __ksymtab_gpl
+ sections. Symbol names and namespaces are stored in __kstrtab and
+ __kstrtabns respectively, using a format similar to the string table
+ used for ELF. If CONFIG_MODVERSIONS is enabled, the CRCs corresponding
+ to exported symbols will be added to the __kcrctab or __kcrctab_gpl.
+
+ If CONFIG_BASIC_MODVERSIONS is enabled (default with
+ CONFIG_MODVERSIONS), imported symbols will have their symbol name and
+ CRC stored in the __versions section of the importing module. This
+ mode only supports symbols of length up to 64 bytes.
+
+ If CONFIG_EXTENDED_MODVERSIONS is enabled (required to enable both
+ CONFIG_MODVERSIONS and CONFIG_RUST at the same time), imported symbols
+ will have their symbol name recorded in the __version_ext_names
+ section as a series of concatenated, null-terminated strings. CRCs for
+ these symbols will be recorded in the __version_ext_crcs section.
+
Symbols and External Modules
----------------------------
Document where exported and imported symbols are kept, format options, and limitations. Signed-off-by: Matthew Maurer <mmaurer@google.com> --- Documentation/kbuild/modules.rst | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)