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tools/bpftool: use version from the kernel source tree

PATCH In review Roman Gushchin 3 participants 4 messages Dec 27, 2017 – Dec 30, 2017

Subsystems (4)
Networking Network drivers BPF bpftool
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Roman Gushchin

author
#0 lore raw

PATCH v3 1/2 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 <[email protected]>
Reviewed-by Jakub Kicinski <[email protected]>
Cc Alexei Starovoitov <[email protected]>
Cc Daniel Borkmann <[email protected]>
---
 tools/bpf/bpftool/Makefile |  3 +++
 tools/bpf/bpftool/main.c   | 13 ++-----------
 2 files changed, 5 insertions(+), 11 deletions(-)
tools/bpf/bpftool/Makefile +3 -0
index 3f17ad317512..f8f31a8d9269 100644
@@ -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
tools/bpf/bpftool/main.c +2 -11
index ecd53ccf1239..3a0396d87c42 100644
@@ -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;
 }
Signature · 1 line
2.14.3
author
#1 lore raw

PATCH v3 2/2 tools/bpftool: fix bpftool build with bintutils >= 2.9

Bpftool build is broken with binutils version 2.29 and later. The cause is commit 003ca0fd2286 ("Refactor disassembler selection") in the binutils repo, which changed the disassembler() function signature.

Fix this by adding a new "feature" to the tools/build/features infrastructure and make it responsible for decision which disassembler() function signature to use.

Signed-off-by Roman Gushchin <[email protected]>
Cc Jakub Kicinski <[email protected]>
Cc Alexei Starovoitov <[email protected]>
Cc Daniel Borkmann <[email protected]>
---
 tools/bpf/Makefile                                | 29 +++++++++++++++++++++++
 tools/bpf/bpf_jit_disasm.c                        |  7 ++++++
 tools/bpf/bpftool/Makefile                        | 24 +++++++++++++++++++
 tools/bpf/bpftool/jit_disasm.c                    |  7 ++++++
 tools/build/feature/Makefile                      |  4 ++++
 tools/build/feature/test-disassembler-four-args.c | 15 ++++++++++++
 6 files changed, 86 insertions(+)
 create mode 100644 tools/build/feature/test-disassembler-four-args.c
tools/bpf/Makefile +29 -0
index 07a6697466ef..c8ec0ae16bf0 100644
@@ -9,6 +9,35 @@ MAKE = make
 CFLAGS += -Wall -O2
 CFLAGS += -D__EXPORTED_HEADERS__ -I../../include/uapi -I../../include
 
+ifeq ($(srctree),)
+srctree := $(patsubst %/,%,$(dir $(CURDIR)))
+srctree := $(patsubst %/,%,$(dir $(srctree)))
+endif
+
+FEATURE_USER = .bpf
+FEATURE_TESTS = libbfd disassembler-four-args
+FEATURE_DISPLAY = libbfd disassembler-four-args
+
+check_feat := 1
+NON_CHECK_FEAT_TARGETS := clean bpftool_clean
+ifdef MAKECMDGOALS
+ifeq ($(filter-out $(NON_CHECK_FEAT_TARGETS),$(MAKECMDGOALS)),)
+  check_feat := 0
+endif
+endif
+
+ifeq ($(check_feat),1)
+ifeq ($(FEATURES_DUMP),)
+include $(srctree)/tools/build/Makefile.feature
+else
+include $(FEATURES_DUMP)
+endif
+endif
+
+ifeq ($(feature-disassembler-four-args), 1)
+CFLAGS += -DDISASM_FOUR_ARGS_SIGNATURE
+endif
+
 %.yacc.c: %.y
 	$(YACC) -o $@ -d $<
tools/bpf/bpf_jit_disasm.c +7 -0
index 75bf526a0168..30044bc4f389 100644
@@ -72,7 +72,14 @@ static void get_asm_insns(uint8_t *image, size_t len, int opcodes)
 
 	disassemble_init_for_target(&info);
 
+#ifdef DISASM_FOUR_ARGS_SIGNATURE
+	disassemble = disassembler(info.arch,
+				   bfd_big_endian(bfdf),
+				   info.mach,
+				   bfdf);
+#else
 	disassemble = disassembler(bfdf);
+#endif
 	assert(disassemble);
 
 	do {
tools/bpf/bpftool/Makefile +24 -0
index f8f31a8d9269..2237bc43f71c 100644
@@ -46,6 +46,30 @@ LIBS = -lelf -lbfd -lopcodes $(LIBBPF)
 INSTALL ?= install
 RM ?= rm -f
 
+FEATURE_USER = .bpftool
+FEATURE_TESTS = libbfd disassembler-four-args
+FEATURE_DISPLAY = libbfd disassembler-four-args
+
+check_feat := 1
+NON_CHECK_FEAT_TARGETS := clean uninstall doc doc-clean doc-install doc-uninstall
+ifdef MAKECMDGOALS
+ifeq ($(filter-out $(NON_CHECK_FEAT_TARGETS),$(MAKECMDGOALS)),)
+  check_feat := 0
+endif
+endif
+
+ifeq ($(check_feat),1)
+ifeq ($(FEATURES_DUMP),)
+include $(srctree)/tools/build/Makefile.feature
+else
+include $(FEATURES_DUMP)
+endif
+endif
+
+ifeq ($(feature-disassembler-four-args), 1)
+CFLAGS += -DDISASM_FOUR_ARGS_SIGNATURE
+endif
+
 include $(wildcard *.d)
 
 all: $(OUTPUT)bpftool
tools/bpf/bpftool/jit_disasm.c +7 -0
index 1551d3918d4c..57d32e8a1391 100644
@@ -107,7 +107,14 @@ void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes)
 
 	disassemble_init_for_target(&info);
 
+#ifdef DISASM_FOUR_ARGS_SIGNATURE
+	disassemble = disassembler(info.arch,
+				   bfd_big_endian(bfdf),
+				   info.mach,
+				   bfdf);
+#else
 	disassemble = disassembler(bfdf);
+#endif
 	assert(disassemble);
 
 	if (json_output)
tools/build/feature/Makefile +4 -0
index 96982640fbf8..17f2c73fff8b 100644
@@ -13,6 +13,7 @@ FILES=                                          \
          test-hello.bin                         \
          test-libaudit.bin                      \
          test-libbfd.bin                        \
+         test-disassembler-four-args.bin        \
          test-liberty.bin                       \
          test-liberty-z.bin                     \
          test-cplus-demangle.bin                \

@@ -188,6 +189,9 @@ $(OUTPUT)test-libpython-version.bin:
 $(OUTPUT)test-libbfd.bin:
 	$(BUILD) -DPACKAGE='"perf"' -lbfd -lz -liberty -ldl
 
+$(OUTPUT)test-disassembler-four-args.bin:
+	$(BUILD) -lbfd -lopcodes
+
 $(OUTPUT)test-liberty.bin:
 	$(CC) $(CFLAGS) -Wall -Werror -o $@ test-libbfd.c -DPACKAGE='"perf"' $(LDFLAGS) -lbfd -ldl -liberty
tools/build/feature/test-disassembler-four-args.c new file +15 -0
new file mode 100644
index 000000000000..45ce65cfddf0
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <bfd.h>
+#include <dis-asm.h>
+
+int main(void)
+{
+	bfd *abfd = bfd_openr(NULL, NULL);
+
+	disassembler(bfd_get_arch(abfd),
+		     bfd_big_endian(abfd),
+		     bfd_get_mach(abfd),
+		     abfd);
+
+	return 0;
+}
Signature · 1 line
2.14.3
Acked-by on v3 2/2
#2 lore raw

Re: [PATCH v3 bpf-next 2/2] tools/bpftool: fix bpftool build with bintutils >= 2.9

Quoted 5 lines · Roman Gushchin

Bpftool build is broken with binutils version 2.29 and later. The cause is commit 003ca0fd2286 ("Refactor disassembler selection") in the binutils repo, which changed the disassembler() function signature.

Quoted 8 lines

Fix this by adding a new "feature" to the tools/build/features infrastructure and make it responsible for decision which disassembler() function signature to use.

Signed-off-by Roman Gushchin <[email protected]>
Cc Jakub Kicinski <[email protected]>
Cc Alexei Starovoitov <[email protected]>
Cc Daniel Borkmann <[email protected]>
Acked-by Jakub Kicinski <[email protected]>
maintainer
#3 lore raw
In reply to Roman Gushchin
Quoted 9 lines · Roman Gushchin

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.

Series applied to bpf-next, thanks everyone!