KCOV_BUF_MEMB_SIZE
if (offset < 0 || offset >= kd->kd_nmemb * KCOV_BUF_MEMB_SIZE)
stride * nmemb * KCOV_BUF_MEMB_SIZE);
size = roundup(nmemb * KCOV_BUF_MEMB_SIZE, PAGE_SIZE);