From: Xin Long <lucien.xin@gmail.com>
Date: Fri, 17 Jul 2020 15:02:30 +0800
Subject: xfrm: interface: use IS_REACHABLE to avoid some compile errors
Patch-mainline: v5.9-rc1
Git-commit: 0a0d93b943a20e4210491911e82c3b4a34391ce4
References: bsc#1176447

kernel test robot reported some compile errors:

  ia64-linux-ld: net/xfrm/xfrm_interface.o: in function `xfrmi4_fini':
  net/xfrm/xfrm_interface.c:900: undefined reference to `xfrm4_tunnel_deregister'
  ia64-linux-ld: net/xfrm/xfrm_interface.c:901: undefined reference to `xfrm4_tunnel_deregister'
  ia64-linux-ld: net/xfrm/xfrm_interface.o: in function `xfrmi4_init':
  net/xfrm/xfrm_interface.c:873: undefined reference to `xfrm4_tunnel_register'
  ia64-linux-ld: net/xfrm/xfrm_interface.c:876: undefined reference to `xfrm4_tunnel_register'
  ia64-linux-ld: net/xfrm/xfrm_interface.c:885: undefined reference to `xfrm4_tunnel_deregister'

This happened when set CONFIG_XFRM_INTERFACE=y and CONFIG_INET_TUNNEL=m.
We don't really want xfrm_interface to depend inet_tunnel completely,
but only to disable the tunnel code when inet_tunnel is not seen.

So instead of adding "select INET_TUNNEL" for XFRM_INTERFACE, this patch
is only to change to IS_REACHABLE to avoid these compile error.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: da9bbf0598c9 ("xfrm: interface: support IPIP and IPIP6 tunnels processing with .cb_handler")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/xfrm/xfrm_interface.c |   16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

--- a/net/xfrm/xfrm_interface.c
+++ b/net/xfrm/xfrm_interface.c
@@ -814,7 +814,7 @@ static struct xfrm6_protocol xfrmi_ipcom
 	.priority	=	10,
 };
 
-#if IS_ENABLED(CONFIG_INET6_XFRM_TUNNEL)
+#if IS_REACHABLE(CONFIG_INET6_XFRM_TUNNEL)
 static int xfrmi6_rcv_tunnel(struct sk_buff *skb)
 {
 	const xfrm_address_t *saddr;
@@ -865,7 +865,7 @@ static struct xfrm4_protocol xfrmi_ipcom
 	.priority	=	10,
 };
 
-#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)
+#if IS_REACHABLE(CONFIG_INET_XFRM_TUNNEL)
 static int xfrmi4_rcv_tunnel(struct sk_buff *skb)
 {
 	return xfrm4_rcv_spi(skb, IPPROTO_IPIP, ip_hdr(skb)->saddr);
@@ -899,7 +899,7 @@ static int __init xfrmi4_init(void)
 	err = xfrm4_protocol_register(&xfrmi_ipcomp4_protocol, IPPROTO_COMP);
 	if (err < 0)
 		goto xfrm_proto_comp_failed;
-#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)
+#if IS_REACHABLE(CONFIG_INET_XFRM_TUNNEL)
 	err = xfrm4_tunnel_register(&xfrmi_ipip_handler, AF_INET);
 	if (err < 0)
 		goto xfrm_tunnel_ipip_failed;
@@ -910,7 +910,7 @@ static int __init xfrmi4_init(void)
 
 	return 0;
 
-#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)
+#if IS_REACHABLE(CONFIG_INET_XFRM_TUNNEL)
 xfrm_tunnel_ipip6_failed:
 	xfrm4_tunnel_deregister(&xfrmi_ipip_handler, AF_INET);
 xfrm_tunnel_ipip_failed:
@@ -926,7 +926,7 @@ xfrm_proto_esp_failed:
 
 static void xfrmi4_fini(void)
 {
-#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)
+#if IS_REACHABLE(CONFIG_INET_XFRM_TUNNEL)
 	xfrm4_tunnel_deregister(&xfrmi_ipip6_handler, AF_INET6);
 	xfrm4_tunnel_deregister(&xfrmi_ipip_handler, AF_INET);
 #endif
@@ -948,7 +948,7 @@ static int __init xfrmi6_init(void)
 	err = xfrm6_protocol_register(&xfrmi_ipcomp6_protocol, IPPROTO_COMP);
 	if (err < 0)
 		goto xfrm_proto_comp_failed;
-#if IS_ENABLED(CONFIG_INET6_XFRM_TUNNEL)
+#if IS_REACHABLE(CONFIG_INET6_XFRM_TUNNEL)
 	err = xfrm6_tunnel_register(&xfrmi_ipv6_handler, AF_INET6);
 	if (err < 0)
 		goto xfrm_tunnel_ipv6_failed;
@@ -959,7 +959,7 @@ static int __init xfrmi6_init(void)
 
 	return 0;
 
-#if IS_ENABLED(CONFIG_INET6_XFRM_TUNNEL)
+#if IS_REACHABLE(CONFIG_INET6_XFRM_TUNNEL)
 xfrm_tunnel_ip6ip_failed:
 	xfrm6_tunnel_deregister(&xfrmi_ipv6_handler, AF_INET6);
 xfrm_tunnel_ipv6_failed:
@@ -975,7 +975,7 @@ xfrm_proto_esp_failed:
 
 static void xfrmi6_fini(void)
 {
-#if IS_ENABLED(CONFIG_INET6_XFRM_TUNNEL)
+#if IS_REACHABLE(CONFIG_INET6_XFRM_TUNNEL)
 	xfrm6_tunnel_deregister(&xfrmi_ip6ip_handler, AF_INET);
 	xfrm6_tunnel_deregister(&xfrmi_ipv6_handler, AF_INET6);
 #endif