From 1d382264d911d91a8be5dbed1f0e053eb3245d81 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Sat, 23 Mar 2019 01:49:10 +0100 Subject: bpf, libbpf: fix version info and add it to shared object Even though libbpf's versioning script for the linker (libbpf.map) is pointing to 0.0.2, the BPF_EXTRAVERSION in the Makefile has not been updated along with it and is therefore still on 0.0.1. While fixing up, I also noticed that the generated shared object versioning information is missing, typical convention is to have a linker name (libbpf.so), soname (libbpf.so.0) and real name (libbpf.so.0.0.2) for library management. This is based upon the LIBBPF_VERSION as well. The build will then produce the following bpf libraries: # ll libbpf* libbpf.a libbpf.so -> libbpf.so.0.0.2 libbpf.so.0 -> libbpf.so.0.0.2 libbpf.so.0.0.2 # readelf -d libbpf.so.0.0.2 | grep SONAME 0x000000000000000e (SONAME) Library soname: [libbpf.so.0] And install them accordingly: # rm -rf /tmp/bld; mkdir /tmp/bld; make -j$(nproc) O=/tmp/bld install Auto-detecting system features: ... libelf: [ on ] ... bpf: [ on ] CC /tmp/bld/libbpf.o CC /tmp/bld/bpf.o CC /tmp/bld/nlattr.o CC /tmp/bld/btf.o CC /tmp/bld/libbpf_errno.o CC /tmp/bld/str_error.o CC /tmp/bld/netlink.o CC /tmp/bld/bpf_prog_linfo.o CC /tmp/bld/libbpf_probes.o CC /tmp/bld/xsk.o LD /tmp/bld/libbpf-in.o LINK /tmp/bld/libbpf.a LINK /tmp/bld/libbpf.so.0.0.2 LINK /tmp/bld/test_libbpf INSTALL /tmp/bld/libbpf.a INSTALL /tmp/bld/libbpf.so.0.0.2 # ll /usr/local/lib64/libbpf.* /usr/local/lib64/libbpf.a /usr/local/lib64/libbpf.so -> libbpf.so.0.0.2 /usr/local/lib64/libbpf.so.0 -> libbpf.so.0.0.2 /usr/local/lib64/libbpf.so.0.0.2 Fixes: 1bf4b05810fe ("tools: bpftool: add probes for eBPF program types") Fixes: 1b76c13e4b36 ("bpf tools: Introduce 'bpf' library and add bpf feature check") Reported-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/Makefile | 42 ++++++++++++++++++++++++++++-------------- 1 file changed, 28 insertions(+), 14 deletions(-) diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile index 61aaacf0cfa1..5bf8e52c41fc 100644 --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -3,7 +3,7 @@ BPF_VERSION = 0 BPF_PATCHLEVEL = 0 -BPF_EXTRAVERSION = 1 +BPF_EXTRAVERSION = 2 MAKEFLAGS += --no-print-directory @@ -79,8 +79,6 @@ export prefix libdir src obj libdir_SQ = $(subst ','\'',$(libdir)) libdir_relative_SQ = $(subst ','\'',$(libdir_relative)) -LIB_FILE = libbpf.a libbpf.so - VERSION = $(BPF_VERSION) PATCHLEVEL = $(BPF_PATCHLEVEL) EXTRAVERSION = $(BPF_EXTRAVERSION) @@ -88,7 +86,10 @@ EXTRAVERSION = $(BPF_EXTRAVERSION) OBJ = $@ N = -LIBBPF_VERSION = $(BPF_VERSION).$(BPF_PATCHLEVEL).$(BPF_EXTRAVERSION) +LIBBPF_VERSION = $(BPF_VERSION).$(BPF_PATCHLEVEL).$(BPF_EXTRAVERSION) + +LIB_TARGET = libbpf.a libbpf.so.$(LIBBPF_VERSION) +LIB_FILE = libbpf.a libbpf.so* # Set compile option CFLAGS ifdef EXTRA_CFLAGS @@ -128,16 +129,18 @@ all: export srctree OUTPUT CC LD CFLAGS V include $(srctree)/tools/build/Makefile.include -BPF_IN := $(OUTPUT)libbpf-in.o -LIB_FILE := $(addprefix $(OUTPUT),$(LIB_FILE)) -VERSION_SCRIPT := libbpf.map +BPF_IN := $(OUTPUT)libbpf-in.o +VERSION_SCRIPT := libbpf.map + +LIB_TARGET := $(addprefix $(OUTPUT),$(LIB_TARGET)) +LIB_FILE := $(addprefix $(OUTPUT),$(LIB_FILE)) GLOBAL_SYM_COUNT = $(shell readelf -s --wide $(BPF_IN) | \ awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {s++} END{print s}') VERSIONED_SYM_COUNT = $(shell readelf -s --wide $(OUTPUT)libbpf.so | \ grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | sort -u | wc -l) -CMD_TARGETS = $(LIB_FILE) +CMD_TARGETS = $(LIB_TARGET) CXX_TEST_TARGET = $(OUTPUT)test_libbpf @@ -170,9 +173,13 @@ $(BPF_IN): force elfdep bpfdep echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/if_xdp.h' differs from latest version at 'include/uapi/linux/if_xdp.h'" >&2 )) || true $(Q)$(MAKE) $(build)=libbpf -$(OUTPUT)libbpf.so: $(BPF_IN) - $(QUIET_LINK)$(CC) --shared -Wl,--version-script=$(VERSION_SCRIPT) \ - $^ -o $@ +$(OUTPUT)libbpf.so: $(OUTPUT)libbpf.so.$(LIBBPF_VERSION) + +$(OUTPUT)libbpf.so.$(LIBBPF_VERSION): $(BPF_IN) + $(QUIET_LINK)$(CC) --shared -Wl,-soname,libbpf.so.$(VERSION) \ + -Wl,--version-script=$(VERSION_SCRIPT) $^ -o $@ + @ln -sf $(@F) $(OUTPUT)libbpf.so + @ln -sf $(@F) $(OUTPUT)libbpf.so.$(VERSION) $(OUTPUT)libbpf.a: $(BPF_IN) $(QUIET_LINK)$(RM) $@; $(AR) rcs $@ $^ @@ -192,6 +199,12 @@ check_abi: $(OUTPUT)libbpf.so exit 1; \ fi +define do_install_mkdir + if [ ! -d '$(DESTDIR_SQ)$1' ]; then \ + $(INSTALL) -d -m 755 '$(DESTDIR_SQ)$1'; \ + fi +endef + define do_install if [ ! -d '$(DESTDIR_SQ)$2' ]; then \ $(INSTALL) -d -m 755 '$(DESTDIR_SQ)$2'; \ @@ -200,8 +213,9 @@ define do_install endef install_lib: all_cmd - $(call QUIET_INSTALL, $(LIB_FILE)) \ - $(call do_install,$(LIB_FILE),$(libdir_SQ)) + $(call QUIET_INSTALL, $(LIB_TARGET)) \ + $(call do_install_mkdir,$(libdir_SQ)); \ + cp -fpR $(LIB_FILE) $(DESTDIR)$(libdir_SQ) install_headers: $(call QUIET_INSTALL, headers) \ @@ -219,7 +233,7 @@ config-clean: clean: $(call QUIET_CLEAN, libbpf) $(RM) $(TARGETS) $(CXX_TEST_TARGET) \ - *.o *~ *.a *.so .*.d .*.cmd LIBBPF-CFLAGS + *.o *~ *.a *.so *.so.$(VERSION) .*.d .*.cmd LIBBPF-CFLAGS $(call QUIET_CLEAN, core-gen) $(RM) $(OUTPUT)FEATURE-DUMP.libbpf -- cgit v1.2.3 From 63197f78bca2d86093126783b0ee6519bd652435 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Sat, 23 Mar 2019 01:49:11 +0100 Subject: bpf, libbpf: clarify bump in libbpf version info The current documentation suggests that we would need to bump the libbpf version on every change. Lets clarify this a bit more and reflect what we do today in practice, that is, bumping it once per development cycle. Fixes: 76d1b894c515 ("libbpf: Document API and ABI conventions") Reported-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/README.rst | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/lib/bpf/README.rst b/tools/lib/bpf/README.rst index 5788479384ca..cef7b77eab69 100644 --- a/tools/lib/bpf/README.rst +++ b/tools/lib/bpf/README.rst @@ -111,6 +111,7 @@ starting from ``0.0.1``. Every time ABI is being changed, e.g. because a new symbol is added or semantic of existing symbol is changed, ABI version should be bumped. +This bump in ABI version is at most once per kernel development cycle. For example, if current state of ``libbpf.map`` is: -- cgit v1.2.3