SHMLBA
addr = (void *)(rounddown2((uintptr_t)shmaddr, SHMLBA));
} else if (((uintptr_t)shmaddr & (SHMLBA-1)) == 0) {
if (shm && (SHMLBA > PAGE_SIZE)) {
int bits = ilog2(SHMLBA >> PAGE_SHIFT) + 1;
rounddown2((vm_offset_t)uap->shmaddr, SHMLBA);
} else if (((vm_offset_t)uap->shmaddr & (SHMLBA-1)) == 0) {