netfilter: nft_set_pipapo: use GFP_KERNEL for insertions

An earlier attempt changed this to GFP_KERNEL, but the get helper is
also called for get requests from userspace, which uses rcu.

Let the caller pass in the kmalloc flags to allow insertions
to schedule if needed.
Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>

net/netfilter/nft_set_pipapo.c

@@ -507,6 +507,7 @@ bool nft_pipapo_lookup(const struct net *net, const struct nft_set *set,
  * @data:	Key data to be matched against existing elements
  * @genmask:	If set, check that element is active in given genmask
  * @tstamp:	timestamp to check for expired elements
+ * @gfp:	the type of memory to allocate (see kmalloc).
  *
  * This is essentially the same as the lookup function, except that it matches
  * key data against the uncommitted copy and doesn't use preallocated maps for
@@ -517,7 +518,7 @@ bool nft_pipapo_lookup(const struct net *net, const struct nft_set *set,
 static struct nft_pipapo_elem *pipapo_get(const struct net *net,
 					  const struct nft_set *set,
 					  const u8 *data, u8 genmask,
-					  u64 tstamp)
+					  u64 tstamp, gfp_t gfp)
 {
 	struct nft_pipapo_elem *ret = ERR_PTR(-ENOENT);
 	struct nft_pipapo *priv = nft_set_priv(set);
@@ -530,13 +531,13 @@ static struct nft_pipapo_elem *pipapo_get(const struct net *net,
 	if (m->bsize_max == 0)
 		return ret;
 
-	res_map = kmalloc_array(m->bsize_max, sizeof(*res_map), GFP_ATOMIC);
+	res_map = kmalloc_array(m->bsize_max, sizeof(*res_map), gfp);
 	if (!res_map) {
 		ret = ERR_PTR(-ENOMEM);
 		goto out;
 	}
 
-	fill_map = kcalloc(m->bsize_max, sizeof(*res_map), GFP_ATOMIC);
+	fill_map = kcalloc(m->bsize_max, sizeof(*res_map), gfp);
 	if (!fill_map) {
 		ret = ERR_PTR(-ENOMEM);
 		goto out;
@@ -614,7 +615,8 @@ nft_pipapo_get(const struct net *net, const struct nft_set *set,
 	struct nft_pipapo_elem *e;
 
 	e = pipapo_get(net, set, (const u8 *)elem->key.val.data,
-		       nft_genmask_cur(net), get_jiffies_64());
+		       nft_genmask_cur(net), get_jiffies_64(),
+		       GFP_ATOMIC);
 	if (IS_ERR(e))
 		return ERR_CAST(e);
 
@@ -1275,7 +1277,7 @@ static int nft_pipapo_insert(const struct net *net, const struct nft_set *set,
 	else
 		end = start;
 
-	dup = pipapo_get(net, set, start, genmask, tstamp);
+	dup = pipapo_get(net, set, start, genmask, tstamp, GFP_KERNEL);
 	if (!IS_ERR(dup)) {
 		/* Check if we already have the same exact entry */
 		const struct nft_data *dup_key, *dup_end;
@@ -1297,7 +1299,8 @@ static int nft_pipapo_insert(const struct net *net, const struct nft_set *set,
 
 	if (PTR_ERR(dup) == -ENOENT) {
 		/* Look for partially overlapping entries */
-		dup = pipapo_get(net, set, end, nft_genmask_next(net), tstamp);
+		dup = pipapo_get(net, set, end, nft_genmask_next(net), tstamp,
+				 GFP_KERNEL);
 	}
 
 	if (PTR_ERR(dup) != -ENOENT) {
@@ -1865,7 +1868,8 @@ static void *pipapo_deactivate(const struct net *net, const struct nft_set *set,
 {
 	struct nft_pipapo_elem *e;
 
-	e = pipapo_get(net, set, data, nft_genmask_next(net), nft_net_tstamp(net));
+	e = pipapo_get(net, set, data, nft_genmask_next(net),
+		       nft_net_tstamp(net), GFP_KERNEL);
 	if (IS_ERR(e))
 		return NULL;