103 lines
2.1 KiB
C
103 lines
2.1 KiB
C
#include <sys/types.h>
|
|
#include <fcntl.h>
|
|
#include <sys/mman.h>
|
|
#include <errno.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
#include <stdio.h>
|
|
|
|
#ifndef O_BINARY
|
|
#define O_BINARY 0
|
|
#endif
|
|
|
|
int
|
|
main ()
|
|
{
|
|
char *data, *data2 = NULL, *data3;
|
|
int i, pagesize;
|
|
int fd;
|
|
|
|
pagesize = 65536; //getpagesize();
|
|
|
|
/*
|
|
* First, make a file with some known garbage in it.
|
|
*/
|
|
data = (char *) malloc (pagesize);
|
|
if (!data)
|
|
exit (1);
|
|
for (i = 0; i < pagesize; ++i)
|
|
*(data + i) = rand ();
|
|
umask (0);
|
|
fd = open ("conftestmmap", O_CREAT | O_TRUNC | O_WRONLY | O_BINARY, 0600);
|
|
if (fd < 0)
|
|
{
|
|
printf ("creat: %d\n", errno);
|
|
exit (1);
|
|
}
|
|
if (write (fd, data, pagesize) != pagesize)
|
|
{
|
|
printf ("write: %d\n", errno);
|
|
exit (1);
|
|
}
|
|
close (fd);
|
|
|
|
/*
|
|
* Next, try to mmap the file.
|
|
*/
|
|
fd = open ("conftestmmap", O_RDWR | O_BINARY);
|
|
if (fd < 0)
|
|
{
|
|
printf ("write: %d\n", errno);
|
|
exit (1);
|
|
}
|
|
if ((data2 = mmap (data2, pagesize, PROT_READ | PROT_WRITE,
|
|
MAP_PRIVATE, fd, 0L)) == MAP_FAILED)
|
|
{
|
|
printf ("mmap: %d\n", errno);
|
|
exit (1);
|
|
}
|
|
for (i = 0; i < pagesize; ++i)
|
|
if (*(data + i) != *(data2 + i))
|
|
{
|
|
printf ("check-if: %d\n", errno);
|
|
exit (1);
|
|
}
|
|
|
|
/*
|
|
* Finally, make sure that changes to the mapped area
|
|
* do not percolate back to the file as seen by read().
|
|
* (This is a bug on some variants of i386 svr4.0.)
|
|
*/
|
|
for (i = 0; i < pagesize; ++i)
|
|
*(data2 + i) = *(data2 + i) + 1;
|
|
data3 = (char *) malloc (pagesize);
|
|
if (!data3)
|
|
{
|
|
printf ("malloc2: %d\n", errno);
|
|
exit (1);
|
|
}
|
|
if (read (fd, data3, pagesize) != pagesize)
|
|
{
|
|
printf ("read: %d\n", errno);
|
|
exit (1);
|
|
}
|
|
for (i = 0; i < pagesize; ++i)
|
|
if (*(data + i) != *(data3 + i))
|
|
{
|
|
printf ("check-if2: %d\n", errno);
|
|
exit (1);
|
|
}
|
|
if (msync (data2, pagesize, MS_SYNC))
|
|
{
|
|
printf ("msync: %d\n", errno);
|
|
exit (1);
|
|
}
|
|
if (munmap (data2, pagesize))
|
|
{
|
|
printf ("munmap: %d\n", errno);
|
|
exit (1);
|
|
}
|
|
close (fd);
|
|
unlink ("conftestmmap");
|
|
exit (0);
|
|
}
|