On Wed, Sep 8, 2021 at 6:01 AM Daniel Borkmann <daniel@xxxxxxxxxxxxx> wrote: > > On 9/8/21 8:55 AM, Andrii Nakryiko wrote: > > From: Quentin Monnet <quentin@xxxxxxxxxxxxx> > > > > Introduce a macro LIBBPF_DEPRECATED_SINCE(major, minor, message) to prepare > > the deprecation of two API functions. This macro marks functions as deprecated > > when libbpf's version reaches the values passed as an argument. > > > > As part of this change libbpf_version.h header is added with recorded major > > (LIBBPF_MAJOR_VERSION) and minor (LIBBPF_MINOR_VERSION) libbpf version macros. > > They are now part of libbpf public API and can be relied upon by user code. > > libbpf_version.h is installed system-wide along other libbpf public headers. > > > > Due to this new build-time auto-generated header, in-kernel applications > > relying on libbpf (resolve_btfids, bpftool, bpf_preload) are updated to > > include libbpf's output directory as part of a list of include search paths. > > Better fix would be to use libbpf's make_install target to install public API > > headers, but that clean up is left out as a future improvement. The build > > changes were tested by building kernel (with KBUILD_OUTPUT and O= specified > > explicitly), bpftool, libbpf, selftests/bpf, and resolve_btfids builds. No > > problems were detected. > > > > Note that because of the constraints of the C preprocessor we have to write > > a few lines of macro magic for each version used to prepare deprecation (0.6 > > for now). > > > > Also, use LIBBPF_DEPRECATED_SINCE() to schedule deprecation of > > btf__get_from_id() and btf__load(), which are replaced by > > btf__load_from_kernel_by_id() and btf__load_into_kernel(), respectively, > > starting from future libbpf v0.6. This is part of libbpf 1.0 effort ([0]). > > > > [0] Closes: https://github.com/libbpf/libbpf/issues/278 > > > > Co-developed-by: Quentin Monnet <quentin@xxxxxxxxxxxxx> > > Signed-off-by: Quentin Monnet <quentin@xxxxxxxxxxxxx> > > Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> > > --- > > > > v1->v2: > > - fix bpf_preload build by adding dependency for iterators/iterators.o on > > libbpf.a generation (caught by BPF CI); > [...] > > @@ -136,7 +140,7 @@ all: fixdep > > > > all_cmd: $(CMD_TARGETS) check > > > > -$(BPF_IN_SHARED): force $(BPF_HELPER_DEFS) > > +$(BPF_IN_SHARED): force $(BPF_GENERATED) > > @(test -f ../../include/uapi/linux/bpf.h -a -f ../../../include/uapi/linux/bpf.h && ( \ > > (diff -B ../../include/uapi/linux/bpf.h ../../../include/uapi/linux/bpf.h >/dev/null) || \ > > echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/bpf.h' differs from latest version at 'include/uapi/linux/bpf.h'" >&2 )) || true > > @@ -154,13 +158,19 @@ $(BPF_IN_SHARED): force $(BPF_HELPER_DEFS) > > 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) $(build)=libbpf OUTPUT=$(SHARED_OBJDIR) CFLAGS="$(CFLAGS) $(SHLIB_FLAGS)" > > > > -$(BPF_IN_STATIC): force $(BPF_HELPER_DEFS) > > +$(BPF_IN_STATIC): force $(BPF_GENERATED) > > $(Q)$(MAKE) $(build)=libbpf OUTPUT=$(STATIC_OBJDIR) > > > > $(BPF_HELPER_DEFS): $(srctree)/tools/include/uapi/linux/bpf.h > > $(QUIET_GEN)$(srctree)/scripts/bpf_doc.py --header \ > > --file $(srctree)/tools/include/uapi/linux/bpf.h > $(BPF_HELPER_DEFS) > > > > +$(VERSION_HDR): force > > + $(QUIET_GEN)echo "/* This file was auto-generated. */" > $@ > > + @echo "" >> $@ > > + @echo "#define LIBBPF_MAJOR_VERSION $(LIBBPF_MAJOR_VERSION)" >> $@ > > + @echo "#define LIBBPF_MINOR_VERSION $(LIBBPF_MINOR_VERSION)" >> $@ > > + > > Looks like CI caught a different issue this time with v2 where it cannot find libbpf_version.h: Yep, I'll keep fixing this. Couldn't repro this locally. But I'm also going to add a long sleep in libbpf_version.h generation to force this kind of issue more easily. Sorry for the noise. > > [...] > CC bench_count.o > GEN /home/runner/work/bpf/bpf/tools/testing/selftests/bpf/bpf-helpers.rst > In file included from /home/runner/work/bpf/bpf/tools/lib/bpf/bpf.h:31, > from /home/runner/work/bpf/bpf/tools/testing/selftests/bpf/bench.h:8, > from benchs/bench_count.c:3: > /home/runner/work/bpf/bpf/tools/lib/bpf/libbpf_common.h:13:10: fatal error: libbpf_version.h: No such file or directory > 13 | #include "libbpf_version.h" > | ^~~~~~~~~~~~~~~~~~ > compilation terminated. > make: *** [Makefile:517: /home/runner/work/bpf/bpf/tools/testing/selftests/bpf/bench_count.o] Error 1 > make: *** Waiting for unfinished jobs.... > GEN /home/runner/work/bpf/bpf/tools/testing/selftests/bpf/bpf-syscall.rst > In file included from /home/runner/work/bpf/bpf/tools/lib/bpf/bpf.h:31, > from bench.h:8, > from bench.c:13: > /home/runner/work/bpf/bpf/tools/lib/bpf/libbpf_common.h:13:10: fatal error: libbpf_version.h: No such file or directory > 13 | #include "libbpf_version.h" > | ^~~~~~~~~~~~~~~~~~ > compilation terminated. > make: *** [Makefile:162: /home/runner/work/bpf/bpf/tools/testing/selftests/bpf/bench.o] Error 1 > > Thanks, > Daniel
