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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or https://opensource.org/licenses/CDDL-1.0.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* --------------------------------------------------------------
* BugId 5047993 : Getting bad read data.
*
* Usage: readmmap <filename>
*
* where:
* filename is an absolute path to the file name.
*
* Return values:
* 1 : error
* 0 : no errors
* --------------------------------------------------------------
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/mman.h>
#include <time.h>
int
main(int argc, char **argv)
{
const char *filename = "badfile";
size_t size = 4395;
size_t idx = 0;
char *buf = NULL;
char *map = NULL;
int fd = -1, bytes, retval = 0;
uint_t seed;
if (argc < 2 || optind == argc) {
(void) fprintf(stderr,
"usage: %s <file name>\n", argv[0]);
exit(1);
}
if ((buf = calloc(1, size)) == NULL) {
perror("calloc");
exit(1);
}
filename = argv[optind];
(void) remove(filename);
fd = open(filename, O_RDWR|O_CREAT|O_TRUNC, 0666);
if (fd == -1) {
perror("open to create");
retval = 1;
goto end;
}
bytes = write(fd, buf, size);
if (bytes != size) {
(void) printf("short write: %d != %zd\n", bytes, size);
retval = 1;
goto end;
}
map = mmap(0, size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
if (map == MAP_FAILED) {
perror("mmap");
retval = 1;
goto end;
}
seed = (uint_t)time(NULL);
srandom(seed);
idx = random() % size;
map[idx] = 1;
if (msync(map, size, MS_SYNC) != 0) {
perror("msync");
retval = 1;
goto end;
}
if (munmap(map, size) != 0) {
perror("munmap");
retval = 1;
goto end;
}
bytes = pread(fd, buf, size, 0);
if (bytes != size) {
(void) printf("short read: %d != %zd\n", bytes, size);
retval = 1;
goto end;
}
if (buf[idx] != 1) {
(void) printf(
"bad data from read! got buf[%zd]=%d, expected 1\n",
idx, buf[idx]);
retval = 1;
goto end;
}
(void) printf("good data from read: buf[%zd]=1\n", idx);
end:
if (fd != -1) {
(void) close(fd);
}
if (buf != NULL) {
free(buf);
}
return (retval);
}
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