int prepare_binprm(struct linux_binprm *bprm)
{
	int retval;
	loff_t pos = 0;

	bprm_fill_uid(bprm);

	/* fill in binprm security blob */
	retval = security_bprm_set_creds(bprm);
	if (retval)
		return retval;
	bprm->called_set_creds = 1;

	memset(bprm->buf, 0, BINPRM_BUF_SIZE);
	return kernel_read(bprm->file, bprm->buf, BINPRM_BUF_SIZE, &pos);
}