1 /* $OpenBSD: mmap0.c,v 1.3 2021/10/24 21:24:20 deraadt Exp $ */
2 /*
3 * Copyright (c) 2011 Ariane van der Steldt <ariane@stack.nl>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 #include <sys/types.h>
19 #include <sys/mman.h>
20 #include <err.h>
21 #include <errno.h>
22 #include <fcntl.h>
23 #include <stdio.h>
24 #include <sysexits.h>
25
26
27 /*
28 * Mmap allocations with len=0 must fail with EINVAL.
29 *
30 * Posix says so and the vmmap implementation may not deal well with them
31 * either.
32 */
33 int
main()34 main()
35 {
36 void *ptr;
37 int errors = 0;
38 int fd;
39
40 fd = open("/dev/zero", O_RDWR);
41 if (fd == -1)
42 err(EX_OSERR, "open");
43
44 ptr = mmap(NULL, 0, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON, -1, 0);
45 if (ptr != MAP_FAILED) {
46 warn("mmap(len=0, MAP_ANON) return %p, expected MAP_FAILED",
47 ptr);
48 errors += 1;
49 } else if (errno != EINVAL) {
50 warn("mmap(len=0, MAP_ANON) errno %d, expected %d",
51 errno, EINVAL);
52 }
53
54 ptr = mmap(NULL, 0, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
55 if (ptr != MAP_FAILED) {
56 warn("mmap(len=0, fd=\"/dev/zero\") returned %p, "
57 "expected MAP_FAILED", ptr);
58 errors += 1;
59 } else if (errno != EINVAL) {
60 warn("mmap(len=0, fd=\"/dev/zero\") errno %d, expected %d",
61 errno, EINVAL);
62 }
63
64 return errors;
65 }
66