init_module(9) Kernel Functions init_module(9)NAME
init_module, cleanup_module - module load and unload functions
SYNOPSIS
#include <linux/module.h>
#include <linux/modversions.h>
int init_module(void);
void cleanup_module(void);
DESCRIPTION
These functions are not part of the kernel but entry points into load‐
able modules. These are the only symbols that must be externally
defined in order to load a module into a running kernel.
When a module is loaded into a running kernel, the init_module(9) func‐
tion within that object file is called to set up the module. The
implementation of that function initializes local features and uses
functions such as register_chrdev(9) to attach itself to the kernel. It
then returns zero(0) if it succeeds. If there is a problem or the mod‐
ule decides that it cannot be loaded, it returns instead an error code
(i.e. -ENODEV) and the kernel releases the module again.
Once loaded, the cleanup_module(9) function of a module is used by the
kernel to remove the module again. The module detaches itself from the
kernel and returns.
RETURN VALUE
The init_module(9) function returns 0 on success, or an error code <0
if the module cannot be initialized.
AVAILABILITY
Linux 1.0+
SEE ALSOMOD_INC_USE_COUNT(9), insmod(1)
Also list some source files for the kernel that implement the functions
of the page.
AUTHOR
Stephen Williams <steve@icarus.com>
BUGS
It is entirely up to the driver to be sure it is detached from the ker‐
nel when unloaded. If a module makes an error in this regard, bad
things may happen.
Linux DDI $Date:$ init_module(9)
