First page Back Continue Last page Overview Graphics
Symbols exported to modules
From a kernel module,
only a limited number of kernel functions can be called
Functions and variables have to be explicitly exported
by the kernel to be visible from a kernel module
Two macros are used in the kernel
to export functions and variables:
- EXPORT_SYMBOL(symbolname), which exports a function or variable to all modules
- EXPORT_SYMBOL_GPL(symbolname), which exports a function or variable only to GPL modules
A normal driver should not need any non-exported function.