/*
 *  Copyright (c) International Business Machines  Corp., 2004
 *  Copyright (c) Linux Test Project, 2013-2016
 *
 * 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.
 */

/*
 * This is a test for the madvise(2) system call. It is intended
 * to provide a complete exposure of the system call. It tests
 * madvise(2) for all error conditions to occur correctly.
 *
 * (A) Test Case for EINVAL
 *  1. start is not page-aligned
 *  2. advice is not a valid value
 *  3. application is attempting to release
 *     locked or shared pages (with MADV_DONTNEED)
 *  4. MADV_MERGEABLE or MADV_UNMERGEABLE was specified in advice,
 *     but the kernel was not configured with CONFIG_KSM.
 *
 * (B) Test Case for ENOMEM
 *  5|6. addresses in the specified range are not currently mapped
 *     or are outside the address space of the process
 *  b. Not enough memory - paging in failed
 *
 * (C) Test Case for EBADF
 *  7. the map exists,
 *     but the area maps something that isn't a file.
 */

#include <sys/types.h>
#include <sys/mman.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "tst_test.h"
#include "lapi/mmap.h"

#define TEST_FILE "testfile"
#define STR "abcdefghijklmnopqrstuvwxyz12345\n"
#define KSM_SYS_DIR	"/sys/kernel/mm/ksm"

static struct stat st;
static long pagesize;
static char *file1;
static char *file2;
static char *ptr_addr;
static char *tmp_addr;
static char *nonalign;

static struct tcase {
	int advice;
	char *name;
	char **addr;
	int exp_errno;
	int skip;
} tcases[] = {
	{MADV_NORMAL,      "MADV_NORMAL",      &nonalign, EINVAL, 0},
	{1212,             "MADV_NORMAL",      &file1,    EINVAL, 0},
	{MADV_DONTNEED,    "MADV_DONTNEED",    &file1,    EINVAL, 1},
	{MADV_MERGEABLE,   "MADV_MERGEABLE",   &file1,    EINVAL, 0},
	{MADV_UNMERGEABLE, "MADV_UNMERGEABLE", &file1,    EINVAL, 0},
	{MADV_NORMAL,      "MADV_NORMAL",      &file2,    ENOMEM, 0},
	{MADV_WILLNEED,    "MADV_WILLNEED",    &file2,    ENOMEM, 0},
	{MADV_WILLNEED,    "MADV_WILLNEED",    &tmp_addr,  EBADF, 0},
};

static void tcases_filter(void)
{
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(tcases); i++) {
		struct tcase *tc = &tcases[i];

		switch (tc->advice) {
		case MADV_DONTNEED:
#if !defined(UCLINUX)
			if (mlock(file1, st.st_size) < 0)
				tst_brk(TBROK | TERRNO, "mlock failed");
			tc->skip = 0;
#endif /* if !defined(UCLINUX) */
		break;

		case MADV_MERGEABLE:
		case MADV_UNMERGEABLE:
			if ((tst_kvercmp(2, 6, 32)) < 0)
				tc->skip = 1;

			/* kernel configured with CONFIG_KSM,
			 * skip EINVAL test for MADV_MERGEABLE. */
			if (access(KSM_SYS_DIR, F_OK) == 0)
				tc->skip = 1;
		break;
		case MADV_WILLNEED:
			/* In kernel commit 1998cc0, madvise(MADV_WILLNEED) to
			 * anon mem doesn't return -EBADF now, as now we support
			 * swap prefretch. */
			if ((tst_kvercmp(3, 9, 0)) > 0 &&
					tc->exp_errno == EBADF)
				tc->skip = 1;
		break;
		default:
		break;
		}
	}
}

static void setup(void)
{
	int i, fd;

	fd = SAFE_OPEN(TEST_FILE, O_RDWR | O_CREAT, 0664);

	pagesize = getpagesize();

	/* Writing 16 pages of random data into this file */
	for (i = 0; i < (pagesize / 2); i++)
		SAFE_WRITE(1, fd, STR, sizeof(STR) - 1);

	SAFE_FSTAT(fd, &st);

	file1 = SAFE_MMAP(0, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
	file2 = SAFE_MMAP(0, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
	SAFE_MUNMAP(file2 + st.st_size - pagesize, pagesize);

	nonalign = file1 + 100;

	ptr_addr = SAFE_MALLOC(st.st_size);
	tmp_addr = (void*)LTP_ALIGN((long)ptr_addr, pagesize);

	SAFE_CLOSE(fd);

	tcases_filter();
}


static void advice_test(unsigned int i)
{
	struct tcase *tc = &tcases[i];

	if (tc->skip == 1) {
		tst_res(TCONF, "%s is not supported", tc->name);
		return;
	}

	TEST(madvise(*(tc->addr), st.st_size, tc->advice));
	if (TEST_RETURN == -1) {
		if (TEST_ERRNO == tc->exp_errno) {
			tst_res(TPASS | TTERRNO, "failed as expected");
		} else {
			tst_res(TFAIL | TTERRNO,
					"failed unexpectedly; expected - %d : %s",
					tc->exp_errno, tst_strerrno(TFAIL | TTERRNO));
		}
	} else {
		tst_res(TFAIL, "madvise succeeded unexpectedly");
	}
}

static void cleanup(void)
{
	free(ptr_addr);
	SAFE_MUNMAP(file1, st.st_size);
	SAFE_MUNMAP(file2, st.st_size - pagesize);
}

static struct tst_test test = {
	.tcnt = ARRAY_SIZE(tcases),
	.test = advice_test,
	.needs_tmpdir = 1,
	.needs_root = 1,
	.setup = setup,
	.cleanup = cleanup,
};