Revert "UBUNTU: SAUCE: net: add recursion limit to GRO"

This reverts commit ac0099a9, as it will
be replaced by the upstream version available in stable kernel release
v4.4.32.
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/net/geneve.c

@@ -460,7 +460,7 @@ static struct sk_buff **geneve_gro_receive(struct sk_buff **head,
 
 	skb_gro_pull(skb, gh_len);
 	skb_gro_postpull_rcsum(skb, gh, gh_len);
-	pp = call_gro_receive(ptype->callbacks.gro_receive, head, skb);
+	pp = ptype->callbacks.gro_receive(head, skb);
 
 out_unlock:
 	rcu_read_unlock();

drivers/net/vxlan.c

@@ -755,7 +755,7 @@ static struct sk_buff **vxlan_gro_receive(struct sk_buff **head,
 		}
 	}
 
-	pp = call_gro_receive(eth_gro_receive, head, skb);
+	pp = eth_gro_receive(head, skb);
 
 out:
 	skb_gro_remcsum_cleanup(skb, &grc);

include/linux/netdevice.h

@@ -2052,10 +2052,7 @@ struct napi_gro_cb {
 	/* Used in foo-over-udp, set in udp[46]_gro_receive */
 	u8	is_ipv6:1;
 
-	/* Number of gro_receive callbacks this packet already went through */
-	u8 recursion_counter:4;
-
-	/* 3 bit hole */
+	/* 7 bit hole */
 
 	/* used to support CHECKSUM_COMPLETE for tunneling protocols */
 	__wsum	csum;
@@ -2066,25 +2063,6 @@ struct napi_gro_cb {
 
 #define NAPI_GRO_CB(skb) ((struct napi_gro_cb *)(skb)->cb)
 
-#define GRO_RECURSION_LIMIT 15
-static inline int gro_recursion_inc_test(struct sk_buff *skb)
-{
-	return ++NAPI_GRO_CB(skb)->recursion_counter == GRO_RECURSION_LIMIT;
-}
-
-typedef struct sk_buff **(*gro_receive_t)(struct sk_buff **, struct sk_buff *);
-static inline struct sk_buff **call_gro_receive(gro_receive_t cb,
-						struct sk_buff **head,
-						struct sk_buff *skb)
-{
-	if (gro_recursion_inc_test(skb)) {
-		NAPI_GRO_CB(skb)->flush |= 1;
-		return NULL;
-	}
-
-	return cb(head, skb);
-}
-
 struct packet_type {
 	__be16			type;	/* This is really htons(ether_type). */
 	struct net_device	*dev;	/* NULL is wildcarded here	     */

net/8021q/vlan.c

@@ -659,7 +659,7 @@ static struct sk_buff **vlan_gro_receive(struct sk_buff **head,
 
 	skb_gro_pull(skb, sizeof(*vhdr));
 	skb_gro_postpull_rcsum(skb, vhdr, sizeof(*vhdr));
-	pp = call_gro_receive(ptype->callbacks.gro_receive, head, skb);
+	pp = ptype->callbacks.gro_receive(head, skb);
 
 out_unlock:
 	rcu_read_unlock();

net/core/dev.c

@@ -4240,7 +4240,6 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff
 		NAPI_GRO_CB(skb)->flush = 0;
 		NAPI_GRO_CB(skb)->free = 0;
 		NAPI_GRO_CB(skb)->encap_mark = 0;
-		NAPI_GRO_CB(skb)->recursion_counter = 0;
 		NAPI_GRO_CB(skb)->gro_remcsum_start = 0;
 
 		/* Setup for GRO checksum validation */

net/ethernet/eth.c

@@ -438,7 +438,7 @@ struct sk_buff **eth_gro_receive(struct sk_buff **head,
 
 	skb_gro_pull(skb, sizeof(*eh));
 	skb_gro_postpull_rcsum(skb, eh, sizeof(*eh));
-	pp = call_gro_receive(ptype->callbacks.gro_receive, head, skb);
+	pp = ptype->callbacks.gro_receive(head, skb);
 
 out_unlock:
 	rcu_read_unlock();

net/ipv4/af_inet.c

@@ -1372,7 +1372,7 @@ static struct sk_buff **inet_gro_receive(struct sk_buff **head,
 	skb_gro_pull(skb, sizeof(*iph));
 	skb_set_transport_header(skb, skb_gro_offset(skb));
 
-	pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
+	pp = ops->callbacks.gro_receive(head, skb);
 
 out_unlock:
 	rcu_read_unlock();

net/ipv4/fou.c

@@ -209,7 +209,7 @@ static struct sk_buff **fou_gro_receive(struct sk_buff **head,
 	if (!ops || !ops->callbacks.gro_receive)
 		goto out_unlock;
 
-	pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
+	pp = ops->callbacks.gro_receive(head, skb);
 
 out_unlock:
 	rcu_read_unlock();
@@ -376,7 +376,7 @@ static struct sk_buff **gue_gro_receive(struct sk_buff **head,
 	if (WARN_ON_ONCE(!ops || !ops->callbacks.gro_receive))
 		goto out_unlock;
 
-	pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
+	pp = ops->callbacks.gro_receive(head, skb);
 
 out_unlock:
 	rcu_read_unlock();

net/ipv4/gre_offload.c

@@ -219,7 +219,7 @@ static struct sk_buff **gre_gro_receive(struct sk_buff **head,
 	/* Adjusted NAPI_GRO_CB(skb)->csum after skb_gro_pull()*/
 	skb_gro_postpull_rcsum(skb, greh, grehlen);
 
-	pp = call_gro_receive(ptype->callbacks.gro_receive, head, skb);
+	pp = ptype->callbacks.gro_receive(head, skb);
 
 out_unlock:
 	rcu_read_unlock();

net/ipv4/udp_offload.c

@@ -339,14 +339,8 @@ struct sk_buff **udp_gro_receive(struct sk_buff **head, struct sk_buff *skb,
 	skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */
 	skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr));
 	NAPI_GRO_CB(skb)->proto = uo_priv->offload->ipproto;
-
-	if (gro_recursion_inc_test(skb)) {
-		flush = 1;
-		pp = NULL;
-	} else {
 	pp = uo_priv->offload->callbacks.gro_receive(head, skb,
 						     uo_priv->offload);
-	}
 
 out_unlock:
 	rcu_read_unlock();

net/ipv6/ip6_offload.c

@@ -247,7 +247,7 @@ static struct sk_buff **ipv6_gro_receive(struct sk_buff **head,
 
 	skb_gro_postpull_rcsum(skb, iph, nlen);
 
-	pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
+	pp = ops->callbacks.gro_receive(head, skb);
 
 out_unlock:
 	rcu_read_unlock();