From: Gianluca Borello <g.borello@gmail.com>
Date: Thu, 26 Oct 2017 01:47:42 +0000
Subject: bpf: remove tail_call and get_stackid helper declarations from bpf.h
Patch-mainline: v4.15-rc1
Git-commit: 035226b964c820f65e201cdf123705a8f1d7c670
References: bsc#1109837

commit afdb09c720b6 ("security: bpf: Add LSM hooks for bpf object related
syscall") included linux/bpf.h in linux/security.h. As a result, bpf
programs including bpf_helpers.h and some other header that ends up
pulling in also security.h, such as several examples under samples/bpf,
fail to compile because bpf_tail_call and bpf_get_stackid are now
"redefined as different kind of symbol".

>From bpf.h:

u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5);
u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);

Whereas in bpf_helpers.h they are:

static void (*bpf_tail_call)(void *ctx, void *map, int index);
static int (*bpf_get_stackid)(void *ctx, void *map, int flags);

Fix this by removing the unused declaration of bpf_tail_call and moving
the declaration of bpf_get_stackid in bpf_trace.c, which is the only
place where it's needed.

Signed-off-by: Gianluca Borello <g.borello@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 include/linux/bpf.h      |    3 ---
 kernel/trace/bpf_trace.c |    2 ++
 2 files changed, 2 insertions(+), 3 deletions(-)

--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -225,9 +225,6 @@ struct bpf_event_entry {
 	struct rcu_head rcu;
 };
 
-u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5);
-u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
-
 bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp);
 int bpf_prog_calc_tag(struct bpf_prog *fp);
 
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -15,6 +15,8 @@
 #include <linux/ctype.h>
 #include "trace.h"
 
+u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
+
 /**
  * trace_call_bpf - invoke BPF program
  * @call: tracepoint event