run_helper
pid = run_helper(pre_exec, &data, args);
err = run_helper(port_pre_exec, &data, argv);
run_helper(NULL, NULL, argv);
run_helper(NULL, NULL, argv);
run_helper(NULL, NULL, argv);
run_helper(NULL, NULL, argv);
pid = run_helper(NULL, NULL, argv);
extern int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv);
EXPORT_SYMBOL(run_helper);