1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (c) Zilogic Systems Pvt. Ltd., 2020
4 * Email: code@zilogic.com
5 */
6
7/*
8 * Test mmap with MAP_FIXED_NOREPLACE flag
9 *
10 * We are testing the MAP_FIXED_NOREPLACE flag of mmap() syscall. To check
11 * if an attempt to mmap at an exisiting mapping fails with EEXIST.
12 * The code allocates a free address by passing NULL to first mmap call
13 * Then tries to mmap with the same address using MAP_FIXED_NOREPLACE flag
14 * and the mapping fails as expected.
15 */
16
17#include <stdio.h>
18#include <fcntl.h>
19#include <sys/types.h>
20#include <sys/stat.h>
21#include <unistd.h>
22#include <errno.h>
23#include <string.h>
24#include <stdlib.h>
25#include "lapi/mmap.h"
26#include "tst_test.h"
27
28static int fd_file1;
29static int fd_file2;
30static void *mapped_address;
31static const char str[] = "Writing to mapped file";
32
33#define FNAME1 "file1_to_mmap"
34#define FNAME2 "file2_to_mmap"
35
36static void setup(void)
37{
38	fd_file1 = SAFE_OPEN(FNAME1, O_CREAT | O_RDWR, 0600);
39	fd_file2 = SAFE_OPEN(FNAME2, O_CREAT | O_RDWR, 0600);
40}
41
42static void cleanup(void)
43{
44	int str_len;
45
46	str_len = strlen(str);
47
48	if (fd_file2 > 0)
49		SAFE_CLOSE(fd_file2);
50	if (fd_file1 > 0)
51		SAFE_CLOSE(fd_file1);
52	if (mapped_address)
53		SAFE_MUNMAP(mapped_address, str_len);
54}
55
56static void test_mmap(void)
57{
58	int str_len;
59	void *address;
60
61	str_len = strlen(str);
62
63	SAFE_WRITE(SAFE_WRITE_ALL, fd_file1, str, str_len);
64	mapped_address = SAFE_MMAP(NULL, str_len, PROT_WRITE,
65				   MAP_PRIVATE, fd_file1, 0);
66
67	SAFE_WRITE(SAFE_WRITE_ALL, fd_file2, str, str_len);
68
69	address = mmap(mapped_address, str_len, PROT_WRITE,
70		  MAP_PRIVATE | MAP_FIXED_NOREPLACE, fd_file2, 0);
71	if (address == MAP_FAILED && errno == EEXIST)
72		tst_res(TPASS, "mmap set errno to EEXIST as expected");
73	else
74		tst_res(TFAIL | TERRNO, "mmap failed, with unexpected error "
75			"code, expected EEXIST");
76}
77
78static struct tst_test test = {
79	.setup = setup,
80	.cleanup = cleanup,
81	.test_all = test_mmap,
82	.min_kver = "4.17",
83	.needs_tmpdir = 1
84};
85