Man page 9 : call_usermodehelper_exec

call_usermodehelper_exec - start a usermode application

int call_usermodehelper_exec(struct subprocess_info *  sub_info , int  wait );

sub_info
    information about the subprocessa

wait
    wait for the application to finish and return status. when UMH_NO_WAIT donAqt wait at all, but you get no useful error back when the program couldnAqt be execAqed. This makes it safe to call from interrupt context.

Runs a user-space application. The application is started asynchronously if wait is not set, and runs as a child of keventd. (ie. it runs with full root capabilities).