icmp: Remove some spurious dropped packet profile hits from the ICMP path

If icmp_rcv() has successfully processed the incoming ICMP datagram, we
should use consume_skb() rather than kfree_skb() because a hit on the likes
of perf -e skb:kfree_skb is not called-for.

Signed-off-by: Rick Jones <rick.jones2@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 2 deletions

diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index 092934032077..39b3ff97a504 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -679,6 +679,7 @@ static int icmpv6_rcv(struct sk_buff *skb)
         const struct in6_addr *saddr, *daddr;
         struct icmp6hdr *hdr;
         u8 type;
+        bool success = false;
 
         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
                 struct sec_path *sp = skb_sec_path(skb);
@@ -726,7 +727,7 @@ static int icmpv6_rcv(struct sk_buff *skb)
                 break;
 
         case ICMPV6_ECHO_REPLY:
-                ping_rcv(skb);
+                success = ping_rcv(skb);
                 break;
 
         case ICMPV6_PKT_TOOBIG:
@@ -790,7 +791,14 @@ static int icmpv6_rcv(struct sk_buff *skb)
                 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
         }
 
-        kfree_skb(skb);
+        /* until the v6 path can be better sorted assume failure and
+         * preserve the status quo behaviour for the rest of the paths to here
+         */
+        if (success)
+                consume_skb(skb);
+        else
+                kfree_skb(skb);
+
         return 0;
 
 csum_error: