/*

 * 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();

}