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/* $Id: tstmmap.c $ */
/** @file
* vboxsf - Simple writable mmap testcase.
*/
/*
* Copyright (C) 2019-2023 Oracle and/or its affiliates.
*
* This file is part of VirtualBox base platform packages, as
* available from https://www.virtualbox.org.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, in version 3 of the
* License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses>.
*
* SPDX-License-Identifier: GPL-3.0-only
*/
/*********************************************************************************************************************************
* Header Files *
*********************************************************************************************************************************/
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
int main(int argc, char **argv)
{
uint8_t abBuf[4096];
int fd;
size_t cErrors = 0;
size_t cbFile;
size_t offFile;
uint8_t *pbMapping;
const char *pszFile = "tstmmap-file1";
if (argc > 1)
pszFile = argv[1];
fd = open(pszFile, O_CREAT | O_TRUNC | O_RDWR, 0660);
if (fd < 0)
{
fprintf(stderr, "error creating file: %s\n", pszFile);
return 1;
}
/* write 64 KB to the file: */
memset(abBuf, 0xf6, sizeof(abBuf));
for (cbFile = 0; cbFile < 0x10000; cbFile += sizeof(abBuf))
if (write(fd, abBuf, sizeof(abBuf)) != sizeof(abBuf))
{
fprintf(stderr, "error writing file: %s\n", pszFile);
return 1;
}
fsync(fd);
/* Map the file: */
pbMapping = (uint8_t *)mmap(NULL, cbFile, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (pbMapping == (void *)-1)
{
fprintf(stderr, "error mapping file: %s\n", pszFile);
return 1;
}
/* Modify the mapping and sync it: */
memset(pbMapping, 0xf7, cbFile);
if (msync(pbMapping, cbFile, MS_SYNC) != 0)
{
fprintf(stderr, "error msync'ing file: %s\n", pszFile);
return 1;
}
/* Unmap and close it: */
if (munmap(pbMapping, cbFile) != 0)
fprintf(stderr, "error munmap'ing file: %s\n", pszFile);
close(fd);
/*
* Open it again and check the content.
*/
fd = open(pszFile, O_RDWR, 0);
if (fd < 0)
{
fprintf(stderr, "error reopening file: %s\n", pszFile);
return 1;
}
while (offFile < cbFile && cErrors < 42)
{
size_t offBuf;
ssize_t cbRead = read(fd, abBuf, sizeof(abBuf));
if (cbRead != (ssize_t)sizeof(abBuf))
{
fprintf(stderr, "error reading file: %zd, off %#zx (%s)\n", cbRead, offFile, pszFile);
return 1;
}
for (offBuf = 0; offBuf < sizeof(abBuf); offBuf++)
if (abBuf[offBuf] != 0xf7)
{
fprintf(stderr, "mismatch at %#zx: %#x, expected %#x\n", offFile + offBuf, abBuf[offBuf], 0xf7);
cErrors++;
if (cErrors > 42)
break;
}
offFile += sizeof(abBuf);
}
close(fd);
return cErrors == 0 ? 0 : 1;
}
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