1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27
28/*
29 * --------------------------------------------------------------
30 *	BugId 5047993 : Getting bad read data.
31 *
32 *	Usage: readmmap <filename>
33 *
34 *	where:
35 *		filename is an absolute path to the file name.
36 *
37 *	Return values:
38 *		1 : error
39 *		0 : no errors
40 * --------------------------------------------------------------
41 */
42#include <stdio.h>
43#include <stdlib.h>
44#include <time.h>
45#include <unistd.h>
46#include <fcntl.h>
47#include <errno.h>
48#include <sys/mman.h>
49
50int
51main(int argc, char **argv)
52{
53	char *filename = "badfile";
54	size_t size = 4395;
55	size_t idx = 0;
56	char *buf = NULL;
57	char *map = NULL;
58	int fd = -1, bytes, retval = 0;
59	unsigned seed;
60
61	if (argc < 2 || optind == argc) {
62		(void) fprintf(stderr,
63		    "usage: %s <file name>\n", argv[0]);
64		exit(1);
65	}
66
67	if ((buf = calloc(1, size)) == NULL) {
68		perror("calloc");
69		exit(1);
70	}
71
72	filename = argv[optind];
73
74	(void) remove(filename);
75
76	fd = open(filename, O_RDWR|O_CREAT|O_TRUNC, 0666);
77	if (fd == -1) {
78		perror("open to create");
79		retval = 1;
80		goto end;
81	}
82
83	bytes = write(fd, buf, size);
84	if (bytes != size) {
85		(void) printf("short write: %d != %zu\n", bytes, size);
86		retval = 1;
87		goto end;
88	}
89
90	map = mmap(0, size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
91	if (map == MAP_FAILED) {
92		perror("mmap");
93		retval = 1;
94		goto end;
95	}
96	seed = time(NULL);
97	srandom(seed);
98
99	idx = random() % size;
100	map[idx] = 1;
101
102	if (msync(map, size, MS_SYNC) != 0) {
103		perror("msync");
104		retval = 1;
105		goto end;
106	}
107
108	if (munmap(map, size) != 0) {
109		perror("munmap");
110		retval = 1;
111		goto end;
112	}
113
114	bytes = pread(fd, buf, size, 0);
115	if (bytes != size) {
116		(void) printf("short read: %d != %zu\n", bytes, size);
117		retval = 1;
118		goto end;
119	}
120
121	if (buf[idx] != 1) {
122		(void) printf(
123		    "bad data from read!  got buf[%zu]=%d, expected 1\n",
124		    idx, buf[idx]);
125		retval = 1;
126		goto end;
127	}
128
129	(void) printf("good data from read: buf[%zu]=1\n", idx);
130end:
131	if (fd != -1) {
132		(void) close(fd);
133	}
134	if (buf != NULL) {
135		free(buf);
136	}
137
138	return (retval);
139}
140