[PATCH net-next 0/4] net: avoid indirect calls in dst functions

[PATCH net-next 0/4] net: avoid indirect calls in dst functions

[Brian Vazquez]

From: brianvv <brianvv@google.com>

Use of the indirect call wrappers in some dst related functions for the
ipv6/ipv4 case. This is a small improvent for CONFIG_RETPOLINE=y

brianvv (4):
  net: use indirect call helpers for dst_input
  net: use indirect call helpers for dst_output
  net: use indirect call helpers for dst_mtu
  net: indirect call helpers for ipv4/ipv6 dst_check functions

 include/net/dst.h   | 25 +++++++++++++++++++++----
 net/core/sock.c     | 12 ++++++++++--
 net/ipv4/route.c    | 12 ++++++++----
 net/ipv4/tcp_ipv4.c |  5 ++++-
 net/ipv6/route.c    | 12 ++++++++----
 net/ipv6/tcp_ipv6.c |  5 ++++-
 6 files changed, 55 insertions(+), 16 deletions(-)

-- 
2.29.2.576.ga3fc446d84-goog

[PATCH net-next 1/4] net: use indirect call helpers for dst_input

[Brian Vazquez]

From: brianvv <brianvv@google.com>

This patch avoids the indirect call for the common case:
ip_local_deliver and ip6_input

Signed-off-by: brianvv <brianvv@google.com>
---
 include/net/dst.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/net/dst.h b/include/net/dst.h
index 10f0a8399867..98cf6e8c06c4 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -18,6 +18,7 @@
 #include <linux/refcount.h>
 #include <net/neighbour.h>
 #include <asm/processor.h>
+#include <linux/indirect_call_wrapper.h>
 
 struct sk_buff;
 
@@ -441,10 +442,13 @@ static inline int dst_output(struct net *net, struct sock *sk, struct sk_buff *s
 	return skb_dst(skb)->output(net, sk, skb);
 }
 
+INDIRECT_CALLABLE_DECLARE(int ip6_input(struct sk_buff *));
+INDIRECT_CALLABLE_DECLARE(int ip_local_deliver(struct sk_buff *));
 /* Input packet from network to transport.  */
 static inline int dst_input(struct sk_buff *skb)
 {
-	return skb_dst(skb)->input(skb);
+	return INDIRECT_CALL_INET(skb_dst(skb)->input,
+				  ip6_input, ip_local_deliver, skb);
 }
 
 static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
-- 
2.29.2.576.ga3fc446d84-goog

[PATCH net-next 2/4] net: use indirect call helpers for dst_output

[Brian Vazquez]

From: brianvv <brianvv@google.com>

This patch avoids the indirect call for the common case:
ip6_output and ip_output

Signed-off-by: brianvv <brianvv@google.com>
---
 include/net/dst.h | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/include/net/dst.h b/include/net/dst.h
index 98cf6e8c06c4..3932e9931f08 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -436,10 +436,16 @@ static inline void dst_set_expires(struct dst_entry *dst, int timeout)
 		dst->expires = expires;
 }
 
+INDIRECT_CALLABLE_DECLARE(int ip6_output(struct net *, struct sock *,
+					 struct sk_buff *));
+INDIRECT_CALLABLE_DECLARE(int ip_output(struct net *, struct sock *,
+					 struct sk_buff *));
 /* Output packet to network from transport.  */
 static inline int dst_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
-	return skb_dst(skb)->output(net, sk, skb);
+	return INDIRECT_CALL_INET(skb_dst(skb)->output,
+				  ip6_output, ip_output,
+				  net, sk, skb);
 }
 
 INDIRECT_CALLABLE_DECLARE(int ip6_input(struct sk_buff *));
-- 
2.29.2.576.ga3fc446d84-goog

[PATCH net-next 3/4] net: use indirect call helpers for dst_mtu

[Brian Vazquez]

From: brianvv <brianvv@google.com>

This patch avoids the indirect call for the common case:
ip6_mtu and ipv4_mtu

Signed-off-by: brianvv <brianvv@google.com>
---
 include/net/dst.h | 4 +++-
 net/ipv4/route.c  | 6 ++++--
 net/ipv6/route.c  | 6 ++++--
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/include/net/dst.h b/include/net/dst.h
index 3932e9931f08..9f474a79ed7d 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -194,9 +194,11 @@ dst_feature(const struct dst_entry *dst, u32 feature)
 	return dst_metric(dst, RTAX_FEATURES) & feature;
 }
 
+INDIRECT_CALLABLE_DECLARE(unsigned int ip6_mtu(const struct dst_entry *));
+INDIRECT_CALLABLE_DECLARE(unsigned int ipv4_mtu(const struct dst_entry *));
 static inline u32 dst_mtu(const struct dst_entry *dst)
 {
-	return dst->ops->mtu(dst);
+	return INDIRECT_CALL_INET(dst->ops->mtu, ip6_mtu, ipv4_mtu, dst);
 }
 
 /* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index e26652ff7059..4fac91f8bd6c 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -135,7 +135,8 @@ static int ip_rt_gc_timeout __read_mostly	= RT_GC_TIMEOUT;
 
 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
 static unsigned int	 ipv4_default_advmss(const struct dst_entry *dst);
-static unsigned int	 ipv4_mtu(const struct dst_entry *dst);
+INDIRECT_CALLABLE_SCOPE
+unsigned int		ipv4_mtu(const struct dst_entry *dst);
 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
 static void		 ipv4_link_failure(struct sk_buff *skb);
 static void		 ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
@@ -1311,7 +1312,7 @@ static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
 	return min(advmss, IPV4_MAX_PMTU - header_size);
 }
 
-static unsigned int ipv4_mtu(const struct dst_entry *dst)
+INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst)
 {
 	const struct rtable *rt = (const struct rtable *)dst;
 	unsigned int mtu = rt->rt_pmtu;
@@ -1333,6 +1334,7 @@ static unsigned int ipv4_mtu(const struct dst_entry *dst)
 
 	return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
 }
+EXPORT_SYMBOL(ipv4_mtu);
 
 static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr)
 {
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 188e114b29b4..22caee290b6c 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -83,7 +83,8 @@ enum rt6_nud_state {
 
 static struct dst_entry	*ip6_dst_check(struct dst_entry *dst, u32 cookie);
 static unsigned int	 ip6_default_advmss(const struct dst_entry *dst);
-static unsigned int	 ip6_mtu(const struct dst_entry *dst);
+INDIRECT_CALLABLE_SCOPE
+unsigned int		ip6_mtu(const struct dst_entry *dst);
 static struct dst_entry *ip6_negative_advice(struct dst_entry *);
 static void		ip6_dst_destroy(struct dst_entry *);
 static void		ip6_dst_ifdown(struct dst_entry *,
@@ -3089,7 +3090,7 @@ static unsigned int ip6_default_advmss(const struct dst_entry *dst)
 	return mtu;
 }
 
-static unsigned int ip6_mtu(const struct dst_entry *dst)
+INDIRECT_CALLABLE_SCOPE unsigned int ip6_mtu(const struct dst_entry *dst)
 {
 	struct inet6_dev *idev;
 	unsigned int mtu;
@@ -3111,6 +3112,7 @@ static unsigned int ip6_mtu(const struct dst_entry *dst)
 
 	return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
 }
+EXPORT_SYMBOL(ip6_mtu);
 
 /* MTU selection:
  * 1. mtu on route is locked - use it
-- 
2.29.2.576.ga3fc446d84-goog

[PATCH net-next 4/4] net: indirect call helpers for ipv4/ipv6 dst_check functions

[Brian Vazquez]

From: brianvv <brianvv@google.com>

This patch avoids the indirect call for the common case:
ip6_dst_check and ipv4_dst_check

Signed-off-by: brianvv <brianvv@google.com>
---
 include/net/dst.h   |  7 ++++++-
 net/core/sock.c     | 12 ++++++++++--
 net/ipv4/route.c    |  6 ++++--
 net/ipv4/tcp_ipv4.c |  5 ++++-
 net/ipv6/route.c    |  6 ++++--
 net/ipv6/tcp_ipv6.c |  5 ++++-
 6 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/include/net/dst.h b/include/net/dst.h
index 9f474a79ed7d..26f134ad3a25 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -459,10 +459,15 @@ static inline int dst_input(struct sk_buff *skb)
 				  ip6_input, ip_local_deliver, skb);
 }
 
+INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
+							  u32));
+INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
+							   u32));
 static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
 {
 	if (dst->obsolete)
-		dst = dst->ops->check(dst, cookie);
+		dst = INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check,
+					 ipv4_dst_check, dst, cookie);
 	return dst;
 }
 
diff --git a/net/core/sock.c b/net/core/sock.c
index 4fd7e785f177..753b831a9d70 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -526,11 +526,17 @@ int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
 }
 EXPORT_SYMBOL(__sk_receive_skb);
 
+INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
+							  u32));
+INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
+							   u32));
 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
 {
 	struct dst_entry *dst = __sk_dst_get(sk);
 
-	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
+	if (dst && dst->obsolete &&
+	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
+			       dst, cookie) == NULL) {
 		sk_tx_queue_clear(sk);
 		sk->sk_dst_pending_confirm = 0;
 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
@@ -546,7 +552,9 @@ struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
 {
 	struct dst_entry *dst = sk_dst_get(sk);
 
-	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
+	if (dst && dst->obsolete &&
+	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
+			       dst, cookie) == NULL) {
 		sk_dst_reset(sk);
 		dst_release(dst);
 		return NULL;
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 4fac91f8bd6c..f06dfba3d272 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -133,7 +133,8 @@ static int ip_rt_gc_timeout __read_mostly	= RT_GC_TIMEOUT;
  *	Interface to generic destination cache.
  */
 
-static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
+INDIRECT_CALLABLE_SCOPE
+struct dst_entry	*ipv4_dst_check(struct dst_entry *dst, u32 cookie);
 static unsigned int	 ipv4_default_advmss(const struct dst_entry *dst);
 INDIRECT_CALLABLE_SCOPE
 unsigned int		ipv4_mtu(const struct dst_entry *dst);
@@ -1188,7 +1189,8 @@ void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
 }
 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
 
-static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
+INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst,
+							 u32 cookie)
 {
 	struct rtable *rt = (struct rtable *) dst;
 
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index af2338294598..aba5061024c7 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1646,6 +1646,8 @@ u16 tcp_v4_get_syncookie(struct sock *sk, struct iphdr *iph,
 	return mss;
 }
 
+INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
+							   u32));
 /* The socket must have it's spinlock held when we get
  * here, unless it is a TCP_LISTEN socket.
  *
@@ -1665,7 +1667,8 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
 		sk_mark_napi_id(sk, skb);
 		if (dst) {
 			if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
-			    !dst->ops->check(dst, 0)) {
+			    !INDIRECT_CALL_1(dst->ops->check, ipv4_dst_check,
+					     dst, 0)) {
 				dst_release(dst);
 				sk->sk_rx_dst = NULL;
 			}
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 22caee290b6c..071b5ff8f88f 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -81,7 +81,8 @@ enum rt6_nud_state {
 	RT6_NUD_SUCCEED = 1
 };
 
-static struct dst_entry	*ip6_dst_check(struct dst_entry *dst, u32 cookie);
+INDIRECT_CALLABLE_SCOPE
+struct dst_entry	*ip6_dst_check(struct dst_entry *dst, u32 cookie);
 static unsigned int	 ip6_default_advmss(const struct dst_entry *dst);
 INDIRECT_CALLABLE_SCOPE
 unsigned int		ip6_mtu(const struct dst_entry *dst);
@@ -2612,7 +2613,8 @@ static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt,
 		return NULL;
 }
 
-static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie)
+INDIRECT_CALLABLE_SCOPE struct dst_entry *ip6_dst_check(struct dst_entry *dst,
+							u32 cookie)
 {
 	struct dst_entry *dst_ret;
 	struct fib6_info *from;
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 1a1510513739..9e61e4fda03e 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1417,6 +1417,8 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *
 	return NULL;
 }
 
+INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
+							   u32));
 /* The socket must have it's spinlock held when we get
  * here, unless it is a TCP_LISTEN socket.
  *
@@ -1470,7 +1472,8 @@ static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
 		sk_mark_napi_id(sk, skb);
 		if (dst) {
 			if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
-			    dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
+			    INDIRECT_CALL_1(dst->ops->check, ip6_dst_check,
+					    dst, np->rx_dst_cookie) == NULL) {
 				dst_release(dst);
 				sk->sk_rx_dst = NULL;
 			}
-- 
2.29.2.576.ga3fc446d84-goog

Re: [PATCH net-next 1/4] net: use indirect call helpers for dst_input

[kernel test robot]

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Hi Brian,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on net-next/master]

url:    https://github.com/0day-ci/linux/commits/Brian-Vazquez/net-avoid-indirect-calls-in-dst-functions/20201211-100941
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 51e13685bd93654e0e9b2559c8e103d6545ddf95
config: x86_64-randconfig-a011-20201209 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/f63e8ffacedd4f9e322d6deaf20adacf4c9e3c87
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Brian-Vazquez/net-avoid-indirect-calls-in-dst-functions/20201211-100941
        git checkout f63e8ffacedd4f9e322d6deaf20adacf4c9e3c87
        # save the attached .config to linux build tree
        make W=1 ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>, old ones prefixed by <<):

>> ERROR: modpost: "ip_local_deliver" [net/decnet/decnet.ko] undefined!

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
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Re: [PATCH net-next 2/4] net: use indirect call helpers for dst_output

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 1389 bytes --]

Hi Brian,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on net-next/master]

url:    https://github.com/0day-ci/linux/commits/Brian-Vazquez/net-avoid-indirect-calls-in-dst-functions/20201211-100941
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 51e13685bd93654e0e9b2559c8e103d6545ddf95
config: x86_64-randconfig-a011-20201209 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/fdc06a361d26c1fda6387e9ce0ac220cbcc1b32a
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Brian-Vazquez/net-avoid-indirect-calls-in-dst-functions/20201211-100941
        git checkout fdc06a361d26c1fda6387e9ce0ac220cbcc1b32a
        # save the attached .config to linux build tree
        make W=1 ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>, old ones prefixed by <<):

>> ERROR: modpost: "ip6_output" [net/decnet/decnet.ko] undefined!
ERROR: modpost: "ip_local_deliver" [net/decnet/decnet.ko] undefined!
>> ERROR: modpost: "ip_output" [net/decnet/decnet.ko] undefined!

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

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