pid = clone(helper_child, (void *) sp, CLONE_VM | SIGCHLD, &data);
if(pid < 0){
printk("run_helper : clone failed, errno = %d\n", errno);
pid = clone(helper_child, (void *) sp, CLONE_VM | SIGCHLD, &data);
if(pid < 0){
printk("run_helper : clone failed, errno = %d\n", errno);