Commit 61c7aa50 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Daniel Borkmann
Browse files

libbpf: Re-build libbpf.so when libbpf.map changes 



Ensure libbpf.so is re-built whenever libbpf.map is modified.  Without this,
changes to libbpf.map are not detected and versioned symbols mismatch error
will be reported until `make clean && make` is used, which is a suboptimal
developer experience.

Fixes: 306b267c ("libbpf: Verify versioned symbols")
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210815070609.987780-8-andrii@kernel.org
parent 7adfc6c9

tools/lib/bpf/Makefile

+5 −5
Original line number Diff line number Diff line
@@ -4,8 +4,9 @@ 
RM ?= rm

srctree = $(abs_srctree)



VERSION_SCRIPT := libbpf.map

LIBBPF_VERSION := $(shell \

	grep -oE '^LIBBPF_([0-9.]+)' libbpf.map | \

	grep -oE '^LIBBPF_([0-9.]+)' $(VERSION_SCRIPT) | \

	sort -rV | head -n1 | cut -d'_' -f2)

LIBBPF_MAJOR_VERSION := $(firstword $(subst ., ,$(LIBBPF_VERSION)))
@@ -110,7 +111,6 @@ SHARED_OBJDIR := $(OUTPUT)sharedobjs/ 
STATIC_OBJDIR	:= $(OUTPUT)staticobjs/

BPF_IN_SHARED	:= $(SHARED_OBJDIR)libbpf-in.o

BPF_IN_STATIC	:= $(STATIC_OBJDIR)libbpf-in.o

VERSION_SCRIPT	:= libbpf.map

BPF_HELPER_DEFS	:= $(OUTPUT)bpf_helper_defs.h



LIB_TARGET	:= $(addprefix $(OUTPUT),$(LIB_TARGET))
@@ -163,10 +163,10 @@ $(BPF_HELPER_DEFS): $(srctree)/tools/include/uapi/linux/bpf.h 


$(OUTPUT)libbpf.so: $(OUTPUT)libbpf.so.$(LIBBPF_VERSION)



$(OUTPUT)libbpf.so.$(LIBBPF_VERSION): $(BPF_IN_SHARED)

$(OUTPUT)libbpf.so.$(LIBBPF_VERSION): $(BPF_IN_SHARED) $(VERSION_SCRIPT)

	$(QUIET_LINK)$(CC) $(LDFLAGS) \

		--shared -Wl,-soname,libbpf.so.$(LIBBPF_MAJOR_VERSION) \

		-Wl,--version-script=$(VERSION_SCRIPT) $^ -lelf -lz -o $@

		-Wl,--version-script=$(VERSION_SCRIPT) $< -lelf -lz -o $@

	@ln -sf $(@F) $(OUTPUT)libbpf.so

	@ln -sf $(@F) $(OUTPUT)libbpf.so.$(LIBBPF_MAJOR_VERSION)
@@ -181,7 +181,7 @@ $(OUTPUT)libbpf.pc: 


check: check_abi



check_abi: $(OUTPUT)libbpf.so

check_abi: $(OUTPUT)libbpf.so $(VERSION_SCRIPT)

	@if [ "$(GLOBAL_SYM_COUNT)" != "$(VERSIONED_SYM_COUNT)" ]; then	 \

		echo "Warning: Num of global symbols in $(BPF_IN_SHARED)"	 \

		     "($(GLOBAL_SYM_COUNT)) does NOT match with num of"	 \