[PATCH net-next v3 2/4] net: use indirect call wrappers at GRO network layer

From: Paolo Abeni
Date: Fri Dec 14 2018 - 05:52:43 EST


This avoids an indirect calls for L3 GRO receive path, both
for ipv4 and ipv6, if the latter is not compiled as a module.

Note that when IPv6 is compiled as builtin, it will be checked first,
so we have a single additional compare for the more common path.

v1 -> v2:
- adapted to INDIRECT_CALL_ changes

Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
---
include/net/inet_common.h | 2 ++
net/core/dev.c | 15 +++++++++++++--
net/ipv6/ip6_offload.c | 6 +++---
3 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/include/net/inet_common.h b/include/net/inet_common.h
index 3ca969cbd161..56e7592811ea 100644
--- a/include/net/inet_common.h
+++ b/include/net/inet_common.h
@@ -2,6 +2,8 @@
#ifndef _INET_COMMON_H
#define _INET_COMMON_H

+#include <linux/indirect_call_wrapper.h>
+
extern const struct proto_ops inet_stream_ops;
extern const struct proto_ops inet_dgram_ops;

diff --git a/net/core/dev.c b/net/core/dev.c
index ed9aa4a91f1f..1b5a4410be0e 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -145,6 +145,7 @@
#include <linux/sctp.h>
#include <net/udp_tunnel.h>
#include <linux/net_namespace.h>
+#include <linux/indirect_call_wrapper.h>

#include "net-sysfs.h"

@@ -5338,6 +5339,8 @@ static void flush_all_backlogs(void)
put_online_cpus();
}

+INDIRECT_CALLABLE_DECLARE(int inet_gro_complete(struct sk_buff *, int));
+INDIRECT_CALLABLE_DECLARE(int ipv6_gro_complete(struct sk_buff *, int));
static int napi_gro_complete(struct sk_buff *skb)
{
struct packet_offload *ptype;
@@ -5357,7 +5360,9 @@ static int napi_gro_complete(struct sk_buff *skb)
if (ptype->type != type || !ptype->callbacks.gro_complete)
continue;

- err = ptype->callbacks.gro_complete(skb, 0);
+ err = INDIRECT_CALL_INET(ptype->callbacks.gro_complete,
+ ipv6_gro_complete, inet_gro_complete,
+ skb, 0);
break;
}
rcu_read_unlock();
@@ -5504,6 +5509,10 @@ static void gro_flush_oldest(struct list_head *head)
napi_gro_complete(oldest);
}

+INDIRECT_CALLABLE_DECLARE(struct sk_buff *inet_gro_receive(struct list_head *,
+ struct sk_buff *));
+INDIRECT_CALLABLE_DECLARE(struct sk_buff *ipv6_gro_receive(struct list_head *,
+ struct sk_buff *));
static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
{
u32 hash = skb_get_hash_raw(skb) & (GRO_HASH_BUCKETS - 1);
@@ -5553,7 +5562,9 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff
NAPI_GRO_CB(skb)->csum_valid = 0;
}

- pp = ptype->callbacks.gro_receive(gro_head, skb);
+ pp = INDIRECT_CALL_INET(ptype->callbacks.gro_receive,
+ ipv6_gro_receive, inet_gro_receive,
+ gro_head, skb);
break;
}
rcu_read_unlock();
diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
index 70f525c33cb6..ff8b484d2258 100644
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -164,8 +164,8 @@ static int ipv6_exthdrs_len(struct ipv6hdr *iph,
return len;
}

-static struct sk_buff *ipv6_gro_receive(struct list_head *head,
- struct sk_buff *skb)
+INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receive(struct list_head *head,
+ struct sk_buff *skb)
{
const struct net_offload *ops;
struct sk_buff *pp = NULL;
@@ -301,7 +301,7 @@ static struct sk_buff *ip4ip6_gro_receive(struct list_head *head,
return inet_gro_receive(head, skb);
}

-static int ipv6_gro_complete(struct sk_buff *skb, int nhoff)
+INDIRECT_CALLABLE_SCOPE int ipv6_gro_complete(struct sk_buff *skb, int nhoff)
{
const struct net_offload *ops;
struct ipv6hdr *iph = (struct ipv6hdr *)(skb->data + nhoff);
--
2.19.2