/*
* libhugetlbfs - Easy use of Linux hugepages
* Copyright (C) 2005-2006 IBM Corporation.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#define _XOPEN_SOURCE 600
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <sys/mman.h>
#include <hugetlbfs.h>
#include "hugetests.h"
/*
* Test rationale:
*
* fadvise() on some kernels can cause the reservation counter to get
* corrupted. The problem is that the patches are allocated for the
* reservation but not faulted in at the time of allocation. The
* counters do not get updated and effectively "leak". This test
* identifies whether the kernel is vunerable to the problem or not.
* It's fixed in kernel by commit f2deae9d4e70793568ef9e85d227abb7bef5b622.
*/
int main(int argc, char *argv[])
{
long hpage_size;
int fd;
void *p;
unsigned long initial_rsvd, map_rsvd, fadvise_rsvd, end_rsvd;
test_init(argc, argv);
/* Setup */
hpage_size = check_hugepagesize();
fd = hugetlbfs_unlinked_fd();
if (fd < 0)
FAIL("hugetlbfs_unlinked_fd()");
initial_rsvd = get_huge_page_counter(hpage_size, HUGEPAGES_RSVD);
verbose_printf("Reserve count before map: %lu\n", initial_rsvd);
/* mmap a region and record reservations */
p = mmap(NULL, hpage_size, PROT_READ|PROT_WRITE, MAP_SHARED,
fd, 0);
if (p == MAP_FAILED)
FAIL("mmap(): %s", strerror(errno));
map_rsvd = get_huge_page_counter(hpage_size, HUGEPAGES_RSVD);
verbose_printf("Reserve count after map: %lu\n", map_rsvd);
/* fadvise the region and record reservations */
if (posix_fadvise(fd, 0, hpage_size, POSIX_FADV_WILLNEED) == -1)
FAIL("fadvise(): %s", strerror(errno));
fadvise_rsvd = get_huge_page_counter(hpage_size, HUGEPAGES_RSVD);
verbose_printf("Reserve count after fadvise: %lu\n", fadvise_rsvd);
/* Write the region */
memset(p, 1, hpage_size);
/* Free region */
munmap(p, hpage_size);
close(fd);
end_rsvd = get_huge_page_counter(hpage_size, HUGEPAGES_RSVD);
verbose_printf("Reserve count after close(): %lu\n", end_rsvd);
/* Reserve count should match initial reserve count */
if (end_rsvd != initial_rsvd)
FAIL("Reserve leaked: %lu != %lu\n", end_rsvd, initial_rsvd);
PASS();
}