openwrt/target/linux/generic/hack-5.4/901-debloat_sock_diag.patch

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
@@ -100,6 +100,9 @@ source "net/netlabel/Kconfig"
 
 endif # if INET
 
+config SOCK_DIAG
+	bool
+
 config NETWORK_SECMARK
 	bool "Security Marking"
 	help
--- a/net/core/Makefile
+++ b/net/core/Makefile
@@ -10,9 +10,10 @@ obj-$(CONFIG_SYSCTL) += sysctl_net_core.
 
 obj-y		     += dev.o ethtool.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
 
+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
@@ -140,6 +140,7 @@
 
 static DEFINE_MUTEX(proto_list_mutex);
 static LIST_HEAD(proto_list);
+static atomic64_t cookie_gen;
 
 static void sock_inuse_add(struct net *net, int val);
 
@@ -539,6 +540,18 @@ discard_and_relse:
 }
 EXPORT_SYMBOL(__sk_receive_skb);
 
+u64 sock_gen_cookie(struct sock *sk)
+{
+	while (1) {
+		u64 res = atomic64_read(&sk->sk_cookie);
+
+		if (res)
+			return res;
+		res = atomic64_inc_return(&cookie_gen);
+		atomic64_cmpxchg(&sk->sk_cookie, 0, res);
+	}
+}
+
 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
 {
 	struct dst_entry *dst = __sk_dst_get(sk);
@@ -1746,9 +1759,11 @@ 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
@@ -19,19 +19,6 @@ static const struct sock_diag_handler *s
 static int (*inet_rcv_compat)(struct sk_buff *skb, struct nlmsghdr *nlh);
 static DEFINE_MUTEX(sock_diag_table_mutex);
 static struct workqueue_struct *broadcast_wq;
-static atomic64_t cookie_gen;
-
-u64 sock_gen_cookie(struct sock *sk)
-{
-	while (1) {
-		u64 res = atomic64_read(&sk->sk_cookie);
-
-		if (res)
-			return res;
-		res = atomic64_inc_return(&cookie_gen);
-		atomic64_cmpxchg(&sk->sk_cookie, 0, res);
-	}
-}
 
 int sock_diag_check_cookie(struct sock *sk, const __u32 *cookie)
 {
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -399,6 +399,7 @@ 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
@@ -28,6 +28,7 @@ config UNIX_SCM
 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.