/*
 * Copyright (c) International Business Machines  Corp., 2004
 * Copyright (c) Linux Test Project, 2004-2017
 *
 * This program is free software;  you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 */

/*
 * DESCRIPTION
 *	hugeshmget03 - test for ENOSPC error
 *
 * HISTORY
 *	03/2001 - Written by Wayne Boyer
 *	04/2004 - Updated by Robbie Williamson
 */

#include <limits.h>
#include "hugetlb.h"
#include "mem.h"
#include "hugetlb.h"

/*
 * The MAXIDS value is somewhat arbitrary and may need to be increased
 * depending on the system being tested.
 */
#define MAXIDS	8192
#define PATH_SHMMNI	"/proc/sys/kernel/shmmni"

static size_t shm_size;
static int shm_id_1 = -1;
static int num_shms;
static int shm_id_arr[MAXIDS];

static long hugepages = 128;
static long orig_shmmni;
static struct tst_option options[] = {
	{"s:", &nr_opt, "-s   num  Set the number of the been allocated hugepages"},
	{NULL, NULL, NULL}
};

static void test_hugeshmget(void)
{
	TEST(shmget(IPC_PRIVATE, shm_size,
				SHM_HUGETLB | IPC_CREAT | IPC_EXCL | SHM_RW));
	if (TEST_RETURN != -1) {
		tst_res(TFAIL, "shmget succeeded unexpectedly");
		return;
	}
	if (TEST_ERRNO == ENOSPC)
		tst_res(TPASS | TTERRNO, "shmget failed as expected");
	else
		tst_res(TFAIL | TTERRNO, "shmget failed unexpectedly "
				"- expect errno=ENOSPC, got");
}

static void setup(void)
{
	long hpage_size;

	check_hugepage();
	if (nr_opt)
		hugepages = SAFE_STRTOL(nr_opt, 0, LONG_MAX);

	orig_hugepages = get_sys_tune("nr_hugepages");
	SAFE_FILE_SCANF(PATH_SHMMNI, "%ld", &orig_shmmni);

	set_sys_tune("nr_hugepages", hugepages, 1);
	SAFE_FILE_PRINTF(PATH_SHMMNI, "%ld", hugepages / 2);

	hpage_size = SAFE_READ_MEMINFO("Hugepagesize:") * 1024;
	shm_size = hpage_size;

	/*
	 * Use a while loop to create the maximum number of memory segments.
	 * If the loop exceeds MAXIDS, then break the test and cleanup.
	 */
	num_shms = 0;
	shm_id_1 = shmget(IPC_PRIVATE, shm_size,
			  SHM_HUGETLB | IPC_CREAT | IPC_EXCL | SHM_RW);
	while (shm_id_1 != -1) {
		shm_id_arr[num_shms++] = shm_id_1;
		if (num_shms == MAXIDS)
			tst_brk(TBROK, "The maximum number of "
				 "shared memory ID's has been reached. "
				 "Please increase the MAXIDS value in "
				 "the test.");
		shm_id_1 = shmget(IPC_PRIVATE, shm_size,
				  SHM_HUGETLB | IPC_CREAT | IPC_EXCL | SHM_RW);
	}
	if (errno != ENOSPC)
		tst_brk(TBROK | TERRNO, "shmget #setup");
}

static void cleanup(void)
{
	int i;

	for (i = 0; i < num_shms; i++)
		rm_shm(shm_id_arr[i]);

	FILE_PRINTF(PATH_SHMMNI, "%ld", orig_shmmni);
	set_sys_tune("nr_hugepages", orig_hugepages, 0);
}

static struct tst_test test = {
	.needs_root = 1,
	.options = options,
	.setup = setup,
	.cleanup = cleanup,
	.test_all = test_hugeshmget,
};
