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 * BugId 5047993 : Getting bad read data.
30 *
31 * Usage: readmmap <filename>
32 *
33 * where:
34 * filename is an absolute path to the file name.
35 *
36 * Return values:
37 * 1 : error
38 * 0 : no errors
39 * --------------------------------------------------------------
40 */
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <unistd.h>
44 #include <fcntl.h>
45 #include <errno.h>
46 #include <sys/mman.h>
47
48 int
main(int argc,char ** argv)49 main(int argc, char **argv)
50 {
51 char *filename = "badfile";
52 size_t size = 4395;
53 size_t idx = 0;
54 char *buf = NULL;
55 char *map = NULL;
56 int fd = -1, bytes, retval = 0;
57 unsigned seed;
58
59 if (argc < 2 || optind == argc) {
60 (void) fprintf(stderr,
61 "usage: %s <file name>\n", argv[0]);
62 exit(1);
63 }
64
65 if ((buf = calloc(1, size)) == NULL) {
66 perror("calloc");
67 exit(1);
68 }
69
70 filename = argv[optind];
71
72 (void) remove(filename);
73
74 fd = open(filename, O_RDWR|O_CREAT|O_TRUNC, 0666);
75 if (fd == -1) {
76 perror("open to create");
77 retval = 1;
78 goto end;
79 }
80
81 bytes = write(fd, buf, size);
82 if (bytes != size) {
83 (void) printf("short write: %d != %ud\n", bytes, size);
84 retval = 1;
85 goto end;
86 }
87
88 map = mmap(0, size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
89 if (map == MAP_FAILED) {
90 perror("mmap");
91 retval = 1;
92 goto end;
93 }
94 seed = time(NULL);
95 srandom(seed);
96
97 idx = random() % size;
98 map[idx] = 1;
99
100 if (msync(map, size, MS_SYNC) != 0) {
101 perror("msync");
102 retval = 1;
103 goto end;
104 }
105
106 if (munmap(map, size) != 0) {
107 perror("munmap");
108 retval = 1;
109 goto end;
110 }
111
112 bytes = pread(fd, buf, size, 0);
113 if (bytes != size) {
114 (void) printf("short read: %d != %ud\n", bytes, size);
115 retval = 1;
116 goto end;
117 }
118
119 if (buf[idx] != 1) {
120 (void) printf(
121 "bad data from read! got buf[%ud]=%d, expected 1\n",
122 idx, buf[idx]);
123 retval = 1;
124 goto end;
125 }
126
127 (void) printf("good data from read: buf[%ud]=1\n", idx);
128 end:
129 if (fd != -1) {
130 (void) close(fd);
131 }
132 if (buf != NULL) {
133 free(buf);
134 }
135
136 return (retval);
137 }
138