EXPORT_NO_SYMBOLS
include/linux/module.hIf a module exports no symbols then you can specify
EXPORT_NO_SYMBOLS;anywhere in the module. In kernel 2.4 and earlier, if a module contains neither
EXPORT_SYMBOL()
nor
EXPORT_NO_SYMBOLS
then the module defaults to
exporting all non-static global symbols.
In kernel 2.5 onwards you must explicitly specify whether a module
exports symbols or not.