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 <sys/types.h> 48 #include <time.h> 49 50 int 51 main(int argc, char **argv) 52 { 53 const 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 uint_t 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 != %zd\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 = (uint_t)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 != %zd\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[%zd]=%d, expected 1\n", 124 idx, buf[idx]); 125 retval = 1; 126 goto end; 127 } 128 129 (void) printf("good data from read: buf[%zd]=1\n", idx); 130 end: 131 if (fd != -1) { 132 (void) close(fd); 133 } 134 if (buf != NULL) { 135 free(buf); 136 } 137 138 return (retval); 139 } 140