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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) International Business Machines Corp., 2001
* 07/2001 Ported by John George
* Copyright (c) 2017 Fujitsu Ltd.
* 04/2017 Modified by Jinhui Huang
*/
/*
* DESCRIPTION
* Testcase to check that write(2) doesn't corrupt a file when it fails
*
* ALGORITHM
* Create a file for writing, write 100 bytes to it. Then make write(2)
* fail with some erroneous parameter, close the fd. Then reopen the
* file in RDONLY mode, and read the contents of the file. Compare the
* buffers, to see whether they are same.
*/
#include <stdio.h>
#include <errno.h>
#include "tst_test.h"
static char *bad_addr;
static char wbuf[BUFSIZ], rbuf[BUFSIZ];
static int fd;
static void verify_write(void)
{
fd = SAFE_CREAT("testfile", 0644);
SAFE_WRITE(1, fd, wbuf, 100);
if (write(fd, bad_addr, 100) != -1) {
tst_res(TFAIL, "write() failed to fail");
SAFE_CLOSE(fd);
return;
}
SAFE_CLOSE(fd);
fd = SAFE_OPEN("testfile", O_RDONLY);
memset(rbuf, 0, BUFSIZ);
SAFE_READ(0, fd, rbuf, 100);
if (memcmp(wbuf, rbuf, 100) == 0)
tst_res(TPASS, "failure of write() did not corrupt the file");
else
tst_res(TFAIL, "failure of write() corrupted the file");
SAFE_CLOSE(fd);
}
static void setup(void)
{
bad_addr = SAFE_MMAP(0, 1, PROT_NONE,
MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
memset(wbuf, '0', 100);
}
static void cleanup(void)
{
if (fd > 0)
SAFE_CLOSE(fd);
}
static struct tst_test test = {
.test_all = verify_write,
.setup = setup,
.cleanup = cleanup,
.needs_tmpdir = 1,
};