From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= <bjorn.topel@intel.com>
Date: Mon, 20 Jan 2020 10:29:17 +0100
Subject: xsk, net: Make sock_def_readable() have external linkage
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Patch-mainline: v5.6-rc1
Git-commit: 43a825afc91e2b06af1e8e7422198e759c2c5e20
References: jsc#SLE-13706

XDP sockets use the default implementation of struct sock's
sk_data_ready callback, which is sock_def_readable(). This function
is called in the XDP socket fast-path, and involves a retpoline. By
letting sock_def_readable() have external linkage, and being called
directly, the retpoline can be avoided.

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200120092917.13949-1-bjorn.topel@gmail.com
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 include/net/sock.h |    2 ++
 net/core/sock.c    |    2 +-
 net/xdp/xsk.c      |    2 +-
 3 files changed, 4 insertions(+), 2 deletions(-)

--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2613,4 +2613,6 @@ static inline bool sk_dev_equal_l3scope(
 	return false;
 }
 
+void sock_def_readable(struct sock *sk);
+
 #endif	/* _SOCK_H */
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2786,7 +2786,7 @@ static void sock_def_error_report(struct
 	rcu_read_unlock();
 }
 
-static void sock_def_readable(struct sock *sk)
+void sock_def_readable(struct sock *sk)
 {
 	struct socket_wq *wq;
 
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -217,7 +217,7 @@ static int xsk_rcv(struct xdp_sock *xs,
 static void xsk_flush(struct xdp_sock *xs)
 {
 	xskq_prod_submit(xs->rx);
-	xs->sk.sk_data_ready(&xs->sk);
+	sock_def_readable(&xs->sk);
 }
 
 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)