* [PATCH bpf v2 1/2] bpf, libbpf: fix version info and add it to shared object
2019-03-23 0:49 [PATCH bpf v2 0/2] libbpf fix up and clarify version info Daniel Borkmann
@ 2019-03-23 0:49 ` Daniel Borkmann
2019-03-23 0:49 ` [PATCH bpf v2 2/2] bpf, libbpf: clarify bump in libbpf version info Daniel Borkmann
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Daniel Borkmann @ 2019-03-23 0:49 UTC (permalink / raw)
To: ast; +Cc: sdf, bpf, netdev, Daniel Borkmann
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 <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
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 61aaacf..5bf8e52 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
--
2.9.5
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH bpf v2 2/2] bpf, libbpf: clarify bump in libbpf version info
2019-03-23 0:49 [PATCH bpf v2 0/2] libbpf fix up and clarify version info Daniel Borkmann
2019-03-23 0:49 ` [PATCH bpf v2 1/2] bpf, libbpf: fix version info and add it to shared object Daniel Borkmann
@ 2019-03-23 0:49 ` Daniel Borkmann
2019-03-23 0:59 ` [PATCH bpf v2 0/2] libbpf fix up and clarify " Stanislav Fomichev
2019-03-25 2:52 ` Alexei Starovoitov
3 siblings, 0 replies; 5+ messages in thread
From: Daniel Borkmann @ 2019-03-23 0:49 UTC (permalink / raw)
To: ast; +Cc: sdf, bpf, netdev, Daniel Borkmann
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 <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
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 5788479..cef7b77 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:
--
2.9.5
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH bpf v2 0/2] libbpf fix up and clarify version info
2019-03-23 0:49 [PATCH bpf v2 0/2] libbpf fix up and clarify version info Daniel Borkmann
2019-03-23 0:49 ` [PATCH bpf v2 1/2] bpf, libbpf: fix version info and add it to shared object Daniel Borkmann
2019-03-23 0:49 ` [PATCH bpf v2 2/2] bpf, libbpf: clarify bump in libbpf version info Daniel Borkmann
@ 2019-03-23 0:59 ` Stanislav Fomichev
2019-03-25 2:52 ` Alexei Starovoitov
3 siblings, 0 replies; 5+ messages in thread
From: Stanislav Fomichev @ 2019-03-23 0:59 UTC (permalink / raw)
To: Daniel Borkmann; +Cc: ast, sdf, bpf, netdev
On 03/23, Daniel Borkmann wrote:
> First one is fixing version in Makefile and shared object and
> second one clarifies bump in version. Thanks!
>
> v1 -> v2:
> - Fix up soname, thanks Stanislav!
LGTM, thank you for a quick fix! For the whole series:
Reviewed-by: Stanislav Fomichev <sdf@google.com>
>
> Daniel Borkmann (2):
> bpf, libbpf: fix version info and add it to shared object
> bpf, libbpf: clarify bump in libbpf version info
>
> tools/lib/bpf/Makefile | 42 ++++++++++++++++++++++++++++--------------
> tools/lib/bpf/README.rst | 1 +
> 2 files changed, 29 insertions(+), 14 deletions(-)
>
> --
> 2.9.5
>
^ permalink raw reply [flat|nested] 5+ messages in thread