1 /*
2 * Copyright (c) 2011 Artur Grabowski <art@openbsd.org>
3 *
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
16
17
18 #include <sys/types.h>
19 #include <sys/mman.h>
20 #include <err.h>
21 #include <stdlib.h>
22 #include <stdio.h>
23 #include <string.h>
24 #include <unistd.h>
25 #include <errno.h>
26
27 /*
28 * Test a corner case writing to a file from an mmap region from that file
29 * should fail.
30 */
31 int
main(int argc,char ** argv)32 main(int argc, char **argv)
33 {
34 char name[20] = "/tmp/fluff.XXXXXX";
35 char *buf;
36 size_t ps;
37 int fd;
38
39 ps = getpagesize();
40
41 if ((fd = mkstemp(name)) == -1)
42 err(1, "mkstemp");
43
44 if (unlink(name) == -1)
45 err(1, "unlink");
46
47 buf = mmap(NULL, ps, PROT_READ, MAP_FILE|MAP_SHARED, fd, 0);
48 if (buf == MAP_FAILED)
49 err(1, "mmap");
50
51 if (pwrite(fd, buf, ps, 0) == ps)
52 errx(1, "write to self succeeded");
53
54 if (errno != EFAULT)
55 err(1, "unexpected errno");
56
57 return (0);
58 }
59