Commit 14e5728f authored by Song Liu's avatar Song Liu Committed by Daniel Borkmann
Browse files

bpftool: Only build bpftool-prog-profile if supported by clang 



bpftool-prog-profile requires clang to generate BTF for global variables.
When compared with older clang, skip this command. This is achieved by
adding a new feature, clang-bpf-global-var, to tools/build/feature.

Signed-off-by: default avatarSong Liu <songliubraving@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Reviewed-by: default avatarQuentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20200312182332.3953408-2-songliubraving@fb.com
parent fe4eb069

tools/bpf/bpftool/Makefile

+11 −4
Original line number Diff line number Diff line
@@ -62,8 +62,9 @@ RM ?= rm -f 
CLANG ?= clang



FEATURE_USER = .bpftool

FEATURE_TESTS = libbfd disassembler-four-args reallocarray zlib

FEATURE_DISPLAY = libbfd disassembler-four-args zlib

FEATURE_TESTS = libbfd disassembler-four-args reallocarray zlib \

	clang-bpf-global-var

FEATURE_DISPLAY = libbfd disassembler-four-args zlib clang-bpf-global-var



check_feat := 1

NON_CHECK_FEAT_TARGETS := clean uninstall doc doc-clean doc-install doc-uninstall
@@ -113,6 +114,12 @@ endif 
OBJS = $(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o

_OBJS = $(filter-out $(OUTPUT)prog.o,$(OBJS)) $(OUTPUT)_prog.o



ifeq ($(feature-clang-bpf-global-var),1)

	__OBJS = $(OBJS)

else

	__OBJS = $(_OBJS)

endif



$(OUTPUT)_prog.o: prog.c

	$(QUIET_CC)$(COMPILE.c) -MMD -DBPFTOOL_WITHOUT_SKELETONS -o $@ $<
@@ -136,8 +143,8 @@ $(OUTPUT)disasm.o: $(srctree)/kernel/bpf/disasm.c 


$(OUTPUT)feature.o: | zdep



$(OUTPUT)bpftool: $(OBJS) $(LIBBPF)

	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(OBJS) $(LIBS)

$(OUTPUT)bpftool: $(__OBJS) $(LIBBPF)

	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(__OBJS) $(LIBS)



$(OUTPUT)%.o: %.c

	$(QUIET_CC)$(COMPILE.c) -MMD -o $@ $<

tools/bpf/bpftool/prog.c

+1 −0
Original line number Diff line number Diff line
@@ -1545,6 +1545,7 @@ static int do_loadall(int argc, char **argv) 


static int do_profile(int argc, char **argv)

{

	p_err("bpftool prog profile command is not supported. Please build bpftool with clang >= 10.0.0");

	return 0;

}

tools/build/feature/Makefile

+8 −1
Original line number Diff line number Diff line
@@ -67,7 +67,8 @@ FILES= \ 
         test-llvm.bin				\

         test-llvm-version.bin			\

         test-libaio.bin			\

         test-libzstd.bin

         test-libzstd.bin			\

         test-clang-bpf-global-var.bin



FILES := $(addprefix $(OUTPUT),$(FILES))
@@ -75,6 +76,7 @@ CC ?= $(CROSS_COMPILE)gcc 
CXX ?= $(CROSS_COMPILE)g++

PKG_CONFIG ?= $(CROSS_COMPILE)pkg-config

LLVM_CONFIG ?= llvm-config

CLANG ?= clang



all: $(FILES)
@@ -321,6 +323,11 @@ $(OUTPUT)test-libaio.bin: 
$(OUTPUT)test-libzstd.bin:

	$(BUILD) -lzstd



$(OUTPUT)test-clang-bpf-global-var.bin:

	$(CLANG) -S -g -target bpf -o - $(patsubst %.bin,%.c,$(@F)) |	\

		grep BTF_KIND_VAR





###############################



clean:

tools/build/feature/test-clang-bpf-global-var.c

0 → 100644
+4 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

// Copyright (c) 2020 Facebook



volatile int global_value_for_test = 1;

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