/*-
 * Copyright (c) 2023 Dmitry Chagin <dchagin@FreeBSD.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include <sys/mman.h>

#include <err.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>

#define MAP_32BIT_MAX_ADDR      ((vm_offset_t)1 << 31)

int
main(void)
{
        size_t pagesize;
        void *s32;
        int fd;

        if ((pagesize = getpagesize()) <= 0)
                err(1, "getpagesize");

        fd = open("/dev/zero", O_RDONLY);
        if (fd <= 0)
                err(1, "open failed");

        s32 = mmap(NULL, pagesize, PROT_READ, MAP_32BIT | MAP_PRIVATE, fd, 0);
        if (s32 == MAP_FAILED)
                err(1, "mmap MAP_32BIT | MAP_PRIVATE failed");
        if (((vm_offset_t)s32 + pagesize) > MAP_32BIT_MAX_ADDR)
                errx(1, "mmap invalid result %p", s32);

        close(fd);
        if (munmap(s32, pagesize) != 0)
                err(1, "munmap failed");

        s32 = mmap(NULL, pagesize, PROT_READ | PROT_WRITE,
            MAP_32BIT | MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
        if (s32 == MAP_FAILED)
                err(1, "mmap MAP_32BIT | MAP_ANONYMOUS | MAP_PRIVATE failed");
        if (((vm_offset_t)s32 + pagesize) > MAP_32BIT_MAX_ADDR)
                errx(1, "mmap invalid result %p", s32);

        if (munmap(s32, pagesize) != 0)
                err(1, "munmap failed");
        exit(0);
}