COMPAT_SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
		       compat_ulong_t __user *, nmask,
		       compat_ulong_t, maxnode,
		       compat_ulong_t, addr, compat_ulong_t, flags)
{
	long err;
	unsigned long __user *nm = NULL;
	unsigned long nr_bits, alloc_size;
	DECLARE_BITMAP(bm, MAX_NUMNODES);

	nr_bits = min_t(unsigned long, maxnode-1, nr_node_ids);
	alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;

	if (nmask)
		nm = compat_alloc_user_space(alloc_size);

	err = kernel_get_mempolicy(policy, nm, nr_bits+1, addr, flags);

	if (!err && nmask) {
		unsigned long copy_size;
		copy_size = min_t(unsigned long, sizeof(bm), alloc_size);
		err = copy_from_user(bm, nm, copy_size);
		/* ensure entire bitmap is zeroed */
		err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8);
		err |= compat_put_bitmap(nmask, bm, nr_bits);
	}

	return err;
}