static int test_check(struct test_region *region)
{
        struct page **pages;
        int nr_pages;
        int result = 0;
        int i;
        int *test;
        pages = kmalloc(sizeof(struct page *) * region->nr_pages, GFP_KERNEL);
        if (!pages)
                return -ENOMEM;
        down_read(&current->mm->mmap_sem);
        nr_pages = get_user_pages(current, current->mm,
                                  region->addr,
                                  region->nr_pages,
                                  1, 0,
                                  pages, NULL);
        /* kmap_atomic would be faster but we want to map over a long time and want to use cache advantages */
        test = (int *)kmap(*pages);
        printk(KERN_ERR "TEST: check value: %d\n", *test);
        kunmap(*pages);
        up_read(&current->mm->mmap_sem);
        if (region->nr_pages != nr_pages) {
                result = -EFAULT;
                goto get_err;
        }
        for (i = 0; i < nr_pages; i++) {
                if (region->pages[i] != pages[i])
                        printk(KERN_ERR "TEST: Check error <%p:%p> "
                               "page <%u> of <%u>\n",
                               pages[i], region->pages[i], i, nr_pages);
                put_page(pages[i]);
        }

get_err:
        kfree(pages);
        return result;
}