1 /* 2 * Copyright (c) 2004 Daniel McNeil <daniel (at) osdl.org> 3 * 2004 Open Source Development Lab 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See 12 * the GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 17 * 18 * Module: .c 19 */ 20 21 /* 22 * Change History: 23 * 24 * 2/2004 Marty Ridgeway (mridge (at) us.ibm.com) Changes to adapt to LTP 25 * 26 */ 27 #define _GNU_SOURCE 28 29 #include <stdlib.h> 30 #include <sys/types.h> 31 #include <signal.h> 32 #include <fcntl.h> 33 #include <stdio.h> 34 #include <unistd.h> 35 36 char *check_zero(unsigned char *buf, int size) 37 { 38 unsigned char *p; 39 40 p = buf; 41 42 while (size > 0) { 43 if (*buf != 0) { 44 fprintf(stderr, 45 "non zero buffer at buf[%d] => 0x%02x,%02x,%02x,%02x\n", 46 buf - p, (unsigned int)buf[0], 47 size > 1 ? (unsigned int)buf[1] : 0, 48 size > 2 ? (unsigned int)buf[2] : 0, 49 size > 3 ? (unsigned int)buf[3] : 0); 50 fprintf(stderr, "buf %p, p %p\n", buf, p); 51 return buf; 52 } 53 buf++; 54 size--; 55 } 56 return 0; /* all zeros */ 57 } 58 59 int read_eof(char *filename) 60 { 61 int fd; 62 int i; 63 int r; 64 char buf[4096]; 65 66 if ((fd = open(filename, O_RDWR)) < 0) { 67 fprintf(stderr, "can't open file %s \n", filename); 68 exit(1); 69 } 70 71 for (i = 0; i < 100000; i++) { 72 off_t offset; 73 char *bufoff; 74 75 offset = lseek(fd, 4096, SEEK_END); 76 r = write(fd, "A", 1); 77 78 offset = lseek(fd, offset - 4096, SEEK_SET); 79 80 r = read(fd, buf, 4096); 81 if (r > 0) { 82 if ((bufoff = check_zero(buf, r))) { 83 fprintf(stderr, "non-zero read at offset %p\n", 84 offset + bufoff); 85 exit(1); 86 } 87 } 88 } 89 fprintf(stderr, "read_checkzero done\n"); 90 return 0; 91 } 92 93 int main(int argc, char **argv) 94 { 95 if (argc < 2) { 96 printf("You must pass a filename to the test \n"); 97 exit(1); 98 } 99 100 char *filename = argv[1]; 101 102 read_eof(filename); 103 104 return 0; 105 } 106
