tools/bpftool: use version from the kernel source tree

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>

diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index 3f17ad3..f8f31a8 100644 (file)
--- 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

diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c
index ecd53cc..3a0396d 100644 (file)
--- 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;
 }