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 https://opensource.org/licenses/CDDL-1.0. 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 #include <time.h> 48 49 int 50 main(int argc, char **argv) 51 { 52 const char *filename = "badfile"; 53 size_t size = 4395; 54 size_t idx = 0; 55 char *buf = NULL; 56 char *map = NULL; 57 int fd = -1, bytes, retval = 0; 58 uint_t seed; 59 60 if (argc < 2 || optind == argc) { 61 (void) fprintf(stderr, 62 "usage: %s <file name>\n", argv[0]); 63 exit(1); 64 } 65 66 if ((buf = calloc(1, size)) == NULL) { 67 perror("calloc"); 68 exit(1); 69 } 70 71 filename = argv[optind]; 72 73 (void) remove(filename); 74 75 fd = open(filename, O_RDWR|O_CREAT|O_TRUNC, 0666); 76 if (fd == -1) { 77 perror("open to create"); 78 retval = 1; 79 goto end; 80 } 81 82 bytes = write(fd, buf, size); 83 if (bytes != size) { 84 (void) printf("short write: %d != %zd\n", bytes, size); 85 retval = 1; 86 goto end; 87 } 88 89 map = mmap(0, size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); 90 if (map == MAP_FAILED) { 91 perror("mmap"); 92 retval = 1; 93 goto end; 94 } 95 seed = (uint_t)time(NULL); 96 srandom(seed); 97 98 idx = random() % size; 99 map[idx] = 1; 100 101 if (msync(map, size, MS_SYNC) != 0) { 102 perror("msync"); 103 retval = 1; 104 goto end; 105 } 106 107 if (munmap(map, size) != 0) { 108 perror("munmap"); 109 retval = 1; 110 goto end; 111 } 112 113 bytes = pread(fd, buf, size, 0); 114 if (bytes != size) { 115 (void) printf("short read: %d != %zd\n", bytes, size); 116 retval = 1; 117 goto end; 118 } 119 120 if (buf[idx] != 1) { 121 (void) printf( 122 "bad data from read! got buf[%zd]=%d, expected 1\n", 123 idx, buf[idx]); 124 retval = 1; 125 goto end; 126 } 127 128 (void) printf("good data from read: buf[%zd]=1\n", idx); 129 end: 130 if (fd != -1) { 131 (void) close(fd); 132 } 133 if (buf != NULL) { 134 free(buf); 135 } 136 137 return (retval); 138 } 139