bind mount & chmod

/* This program changes the permission of '/dev/null' to 06000.  Is it right behavior?
 */
#include <stdio.h>
#include <unistd.h>
#include <sys/mount.h>

int
main()
{
  if (mount("/dev/null", "/dev/console", "none", MS_BIND, 0)) {
    perror("mount");
    return -1;
  }
  if (chmod("/dev/console", 0600)) {
    perror("chmod");
    return -1;
  }
  if (umount("/dev/console")) {
    perror("umount");
    return -1;
  }
  return 0;
}