if ((shmid = shmget(key, 16*K_1, IPC_CREAT|0666)) < 0 ) {
  tst_resm(TFAIL, "shmget Failed.\n");
}
tst_resm(TPASS, "shmget") ;

cp = (char *) shmat(shmid, (void *)0x80000, 0);
if (cp == (char *)-1) {
  tst_resm(TFAIL, "shmat Failed.\n");
}
*cp     = '1';
*(cp+1) = '2';
tst_resm(TPASS, "shmat") ;

r = shmdt(cp);
if (r  < 0) {
  tst_resm(TFAIL, "shmdt Failed.\n");
}
tst_resm(TPASS, "shmdt first time.");

r = shmdt(cp);
if (r == 0) {
  tst_resm(TFAIL, "shmdt Failed.\n");
}
tst_resm(TPASS, "shmdt second time.");