From: Andrey Ignatov <rdna@fb.com>
Date: Fri, 25 May 2018 08:55:22 -0700
Subject: bpf: Define cgroup_bpf_enabled for CONFIG_CGROUP_BPF=n
Patch-mainline: v4.18-rc1
Git-commit: 13193b0f392f5a65d0d54185cb95ed5e99c0a5bf
References: bsc#1109837

Static key is used to enable/disable cgroup-bpf related code paths at
run time.

Though it's not defined when cgroup-bpf is disabled at compile time,
i.e. CONFIG_CGROUP_BPF=n, and if some code wants to use it, it has to do
this:

	#ifdef CONFIG_CGROUP_BPF
		if (cgroup_bpf_enabled) {
			/* ... some work ... */
		}
	#endif

This code can be simplified by setting cgroup_bpf_enabled to 0 for
CONFIG_CGROUP_BPF=n case:

	if (cgroup_bpf_enabled) {
		/* ... some work ... */
	}

And it aligns well with existing BPF_CGROUP_RUN_PROG_* macros that
defined for both states of CONFIG_CGROUP_BPF.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 include/linux/bpf-cgroup.h |    1 +
 1 file changed, 1 insertion(+)

--- a/include/linux/bpf-cgroup.h
+++ b/include/linux/bpf-cgroup.h
@@ -184,6 +184,7 @@ struct cgroup_bpf {};
 static inline void cgroup_bpf_put(struct cgroup *cgrp) {}
 static inline int cgroup_bpf_inherit(struct cgroup *cgrp) { return 0; }
 
+#define cgroup_bpf_enabled (0)
 #define BPF_CGROUP_PRE_CONNECT_ENABLED(sk) (0)
 #define BPF_CGROUP_RUN_PROG_INET_INGRESS(sk,skb) ({ 0; })
 #define BPF_CGROUP_RUN_PROG_INET_EGRESS(sk,skb) ({ 0; })