From 3b6115d6b57a263bdc8c9b1df273bd4a7955eead Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Sat, 8 Jul 2017 08:16:31 +0200
Subject: debloat: add some debloat patches, strip down procfs and make O_DIRECT support optional, saves ~15K after lzma on MIPS

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 net/Kconfig         | 3 +++
 net/core/Makefile   | 3 ++-
 net/core/sock.c     | 2 ++
 net/ipv4/Kconfig    | 1 +
 net/netlink/Kconfig | 1 +
 net/packet/Kconfig  | 1 +
 net/unix/Kconfig    | 1 +
 7 files changed, 11 insertions(+), 1 deletion(-)

--- a/net/Kconfig
+++ b/net/Kconfig
@@ -129,6 +129,9 @@ source "net/mptcp/Kconfig"
 
 endif # if INET
 
+config SOCK_DIAG
+	bool
+
 config NETWORK_SECMARK
 	bool "Security Marking"
 	help
--- a/net/core/Makefile
+++ b/net/core/Makefile
@@ -11,12 +11,13 @@ obj-$(CONFIG_SYSCTL) += sysctl_net_core.
 
 obj-y		     += dev.o dev_addr_lists.o dst.o netevent.o \
 			neighbour.o rtnetlink.o utils.o link_watch.o filter.o \
-			sock_diag.o dev_ioctl.o tso.o sock_reuseport.o \
+			dev_ioctl.o tso.o sock_reuseport.o \
 			fib_notifier.o xdp.o flow_offload.o gro.o \
 			netdev-genl.o netdev-genl-gen.o gso.o
 
 obj-$(CONFIG_NETDEV_ADDR_LIST_TEST) += dev_addr_lists_test.o
 
+obj-$(CONFIG_SOCK_DIAG) += sock_diag.o
 obj-y += net-sysfs.o
 obj-$(CONFIG_PAGE_POOL) += page_pool.o
 obj-$(CONFIG_PROC_FS) += net-procfs.o
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -118,6 +118,7 @@
 #include <linux/mroute.h>
 #include <linux/mroute6.h>
 #include <linux/icmpv6.h>
+#include <linux/cookie.h>
 
 #include <linux/uaccess.h>
 
@@ -150,6 +151,7 @@
 
 static DEFINE_MUTEX(proto_list_mutex);
 static LIST_HEAD(proto_list);
+DEFINE_COOKIE(sock_cookie);
 
 static void sock_def_write_space_wfree(struct sock *sk);
 static void sock_def_write_space(struct sock *sk);
@@ -590,6 +592,21 @@ discard_and_relse:
 }
 EXPORT_SYMBOL(__sk_receive_skb);
 
+u64 __sock_gen_cookie(struct sock *sk)
+{
+	u64 res = atomic64_read(&sk->sk_cookie);
+
+	if (!res) {
+		u64 new = gen_cookie_next(&sock_cookie);
+
+		atomic64_cmpxchg(&sk->sk_cookie, res, new);
+
+		/* Another thread might have changed sk_cookie before us. */
+		res = atomic64_read(&sk->sk_cookie);
+	}
+	return res;
+}
+
 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 *,
@@ -2247,9 +2264,11 @@ static void __sk_free(struct sock *sk)
 	if (likely(sk->sk_net_refcnt))
 		sock_inuse_add(sock_net(sk), -1);
 
+#ifdef CONFIG_SOCK_DIAG
 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
 		sock_diag_broadcast_destroy(sk);
 	else
+#endif
 		sk_destruct(sk);
 }
 
--- a/net/core/sock_diag.c
+++ b/net/core/sock_diag.c
@@ -12,7 +12,6 @@
 #include <linux/tcp.h>
 #include <linux/workqueue.h>
 #include <linux/nospec.h>
-#include <linux/cookie.h>
 #include <linux/inet_diag.h>
 #include <linux/sock_diag.h>
 
@@ -21,23 +20,6 @@ static int (*inet_rcv_compat)(struct sk_
 static DEFINE_MUTEX(sock_diag_table_mutex);
 static struct workqueue_struct *broadcast_wq;
 
-DEFINE_COOKIE(sock_cookie);
-
-u64 __sock_gen_cookie(struct sock *sk)
-{
-	u64 res = atomic64_read(&sk->sk_cookie);
-
-	if (!res) {
-		u64 new = gen_cookie_next(&sock_cookie);
-
-		atomic64_cmpxchg(&sk->sk_cookie, res, new);
-
-		/* Another thread might have changed sk_cookie before us. */
-		res = atomic64_read(&sk->sk_cookie);
-	}
-	return res;
-}
-
 int sock_diag_check_cookie(struct sock *sk, const __u32 *cookie)
 {
 	u64 res;
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -423,6 +423,7 @@ config INET_TUNNEL
 
 config INET_DIAG
 	tristate "INET: socket monitoring interface"
+	select SOCK_DIAG
 	default y
 	help
 	  Support for INET (TCP, DCCP, etc) socket monitoring interface used by
--- a/net/netlink/Kconfig
+++ b/net/netlink/Kconfig
@@ -5,6 +5,7 @@
 
 config NETLINK_DIAG
 	tristate "NETLINK: socket monitoring interface"
+	select SOCK_DIAG
 	default n
 	help
 	  Support for NETLINK socket monitoring interface used by the ss tool.
--- a/net/packet/Kconfig
+++ b/net/packet/Kconfig
@@ -19,6 +19,7 @@ config PACKET
 config PACKET_DIAG
 	tristate "Packet: sockets monitoring interface"
 	depends on PACKET
+	select SOCK_DIAG
 	default n
 	help
 	  Support for PF_PACKET sockets monitoring interface used by the ss tool.
--- a/net/unix/Kconfig
+++ b/net/unix/Kconfig
@@ -29,6 +29,7 @@ config	AF_UNIX_OOB
 config UNIX_DIAG
 	tristate "UNIX: socket monitoring interface"
 	depends on UNIX
+	select SOCK_DIAG
 	default n
 	help
 	  Support for UNIX socket monitoring interface used by the ss tool.
--- a/net/xdp/Kconfig
+++ b/net/xdp/Kconfig
@@ -10,6 +10,7 @@ config XDP_SOCKETS
 config XDP_SOCKETS_DIAG
 	tristate "XDP sockets: monitoring interface"
 	depends on XDP_SOCKETS
+	select SOCK_DIAG
 	default n
 	help
 	  Support for PF_XDP sockets monitoring interface used by the ss tool.