moduload(2)

moduload -- unload a loadable kernel module on demand

Synopsis

   #include <sys/mod.h>
   
   int moduload(int modid);

Description

moduload allows processes with privilege P_LOADMOD to demand-unload a loadable module--or all loadable modules--from a running system.

If modid specifies a module identifier, moduload attempts to unload that module. If modid specifies 0 (zero), moduload attempts to unload all loadable modules.

Loadable modules are considered unloadable if all of the following conditions are true:

the module is not currently being used
the module is not currently being loaded or unloaded
no module that depends on the module is currently loaded
profiling is disabled

When moduload finds that it cannot demand-unload a module for one of the reasons cited above, it flags the module as a candidate for subsequent unloading by the kernel's auto-unload mechanism.

Tasks performed during the unload operation include:

logically disconnect the module from the running system by removing the module's switch table entry
execute the module's wrapper routine to perform any cleanup the module requires to remove itself from the system
free kernel memory allocated for the module

Return values

On success, moduload returns 0. On failure, moduload returns -1 and sets errno to identify the error.

Errors

In the following conditions, moduload fails and sets errno to:

EBUSY: Outstanding references to this module exist, or modules that depend on this module are currently loaded, or profiling is not enabled, or this module is in the process of being loaded or unloaded.
EINVAL: modid does not specify a valid loadable module identifier, or modid is not currently loaded.
EPERM: The caller does not possess P_LOADMOD privileges.
ENOSYS: Unable to perform the requested operation because the loadable modules functions are not configured into the system.

References

modadmin(1M), modload(2), modpath(2), modstat(2)