From: Roman Gushchin <guro@fb.com>
Date: Wed, 27 Dec 2017 19:16:28 +0000
Subject: tools/bpftool: use version from the kernel source tree
Patch-mainline: v4.16-rc1
Git-commit: 4bfe3bd3cc351efd1d51b3258b060e9445533888
References: bsc#1109837

Bpftool determines it's own version based on the kernel
version, which is picked from the linux/version.h header.

It's strange to use the version of the installed kernel
headers, and makes much more sense to use the version
of the actual source tree, where bpftool sources are.

Fix this by building kernelversion target and use
the resulting string as bpftool version.

Example:
before:

$ bpftool version
bpftool v4.14.6

after:
$ bpftool version
bpftool v4.15.0-rc3

$bpftool version --json
{"version":"4.15.0-rc3"}

Signed-off-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 tools/bpf/bpftool/Makefile |    3 +++
 tools/bpf/bpftool/main.c   |   13 ++-----------
 2 files changed, 5 insertions(+), 11 deletions(-)

--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -23,6 +23,8 @@ endif
 
 LIBBPF = $(BPF_PATH)libbpf.a
 
+BPFTOOL_VERSION=$(shell make --no-print-directory -sC ../../.. kernelversion)
+
 $(LIBBPF): FORCE
 	$(Q)$(MAKE) -C $(BPF_DIR) OUTPUT=$(OUTPUT) $(OUTPUT)libbpf.a FEATURES_DUMP=$(FEATURE_DUMP_EXPORT)
 
@@ -38,6 +40,7 @@ CC = gcc
 CFLAGS += -O2
 CFLAGS += -W -Wall -Wextra -Wno-unused-parameter -Wshadow
 CFLAGS += -D__EXPORTED_HEADERS__ -I$(srctree)/tools/include/uapi -I$(srctree)/tools/include -I$(srctree)/tools/lib/bpf -I$(srctree)/kernel/bpf/
+CFLAGS += -DBPFTOOL_VERSION='"$(BPFTOOL_VERSION)"'
 LIBS = -lelf -lbfd -lopcodes $(LIBBPF)
 
 INSTALL ?= install
--- a/tools/bpf/bpftool/main.c
+++ b/tools/bpf/bpftool/main.c
@@ -38,7 +38,6 @@
 #include <errno.h>
 #include <getopt.h>
 #include <linux/bpf.h>
-#include <linux/version.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -95,21 +94,13 @@ static int do_help(int argc, char **argv
 
 static int do_version(int argc, char **argv)
 {
-	unsigned int version[3];
-
-	version[0] = LINUX_VERSION_CODE >> 16;
-	version[1] = LINUX_VERSION_CODE >> 8 & 0xf;
-	version[2] = LINUX_VERSION_CODE & 0xf;
-
 	if (json_output) {
 		jsonw_start_object(json_wtr);
 		jsonw_name(json_wtr, "version");
-		jsonw_printf(json_wtr, "\"%u.%u.%u\"",
-			     version[0], version[1], version[2]);
+		jsonw_printf(json_wtr, "\"%s\"", BPFTOOL_VERSION);
 		jsonw_end_object(json_wtr);
 	} else {
-		printf("%s v%u.%u.%u\n", bin_name,
-		       version[0], version[1], version[2]);
+		printf("%s v%s\n", bin_name, BPFTOOL_VERSION);
 	}
 	return 0;
 }