SHM_RDONLY
if ((shmflg & SHM_RDONLY) == 0)
(uap->shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W);
if ((uap->shmflg & SHM_RDONLY) == 0)
(shmat_msg->shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W);