Re: [PATCH bpf] tools/bpf: build: make sure resolve_btfids cleans up after itself

[Jiri Olsa <jolsa@redhat.com>]

On Tue, Sep 01, 2020 at 06:08:04PM +0200, Toke Høiland-Jørgensen wrote:
> Jiri Olsa <jolsa@redhat.com> writes:
> 
> > On Tue, Sep 01, 2020 at 04:43:43PM +0200, Toke Høiland-Jørgensen wrote:
> >> The new resolve_btfids tool did not clean up the feature detection folder
> >> on 'make clean', and also was not called properly from the clean rule in
> >> tools/make/ folder on its 'make clean'. This lead to stale objects being
> >> left around, which could cause feature detection to fail on subsequent
> >> builds.
> >> 
> >> Fixes: fbbb68de80a4 ("bpf: Add resolve_btfids tool to resolve BTF IDs in ELF object")
> >> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
> >> ---
> >>  tools/bpf/Makefile                | 4 ++--
> >>  tools/bpf/resolve_btfids/Makefile | 1 +
> >>  2 files changed, 3 insertions(+), 2 deletions(-)
> >> 
> >> diff --git a/tools/bpf/Makefile b/tools/bpf/Makefile
> >> index 0a6d09a3e91f..39bb322707b4 100644
> >> --- a/tools/bpf/Makefile
> >> +++ b/tools/bpf/Makefile
> >> @@ -38,7 +38,7 @@ FEATURE_TESTS = libbfd disassembler-four-args
> >>  FEATURE_DISPLAY = libbfd disassembler-four-args
> >>  
> >>  check_feat := 1
> >> -NON_CHECK_FEAT_TARGETS := clean bpftool_clean runqslower_clean
> >> +NON_CHECK_FEAT_TARGETS := clean bpftool_clean runqslower_clean resolve_btfids_clean
> >>  ifdef MAKECMDGOALS
> >>  ifeq ($(filter-out $(NON_CHECK_FEAT_TARGETS),$(MAKECMDGOALS)),)
> >>    check_feat := 0
> >> @@ -89,7 +89,7 @@ $(OUTPUT)bpf_exp.lex.c: $(OUTPUT)bpf_exp.yacc.c
> >>  $(OUTPUT)bpf_exp.yacc.o: $(OUTPUT)bpf_exp.yacc.c
> >>  $(OUTPUT)bpf_exp.lex.o: $(OUTPUT)bpf_exp.lex.c
> >>  
> >> -clean: bpftool_clean runqslower_clean
> >> +clean: bpftool_clean runqslower_clean resolve_btfids_clean
> >>  	$(call QUIET_CLEAN, bpf-progs)
> >>  	$(Q)$(RM) -r -- $(OUTPUT)*.o $(OUTPUT)bpf_jit_disasm $(OUTPUT)bpf_dbg \
> >>  	       $(OUTPUT)bpf_asm $(OUTPUT)bpf_exp.yacc.* $(OUTPUT)bpf_exp.lex.*
> >> diff --git a/tools/bpf/resolve_btfids/Makefile b/tools/bpf/resolve_btfids/Makefile
> >> index a88cd4426398..fe8eb537688b 100644
> >> --- a/tools/bpf/resolve_btfids/Makefile
> >> +++ b/tools/bpf/resolve_btfids/Makefile
> >> @@ -80,6 +80,7 @@ libbpf-clean:
> >>  clean: libsubcmd-clean libbpf-clean fixdep-clean
> >>  	$(call msg,CLEAN,$(BINARY))
> >>  	$(Q)$(RM) -f $(BINARY); \
> >> +	$(RM) -rf $(if $(OUTPUT),$(OUTPUT),.)/feature; \
> >
> > I forgot this one.. thanks for fixing this
> 
> You're welcome - it was a bit frustrating to track down, but a simple
> fix once I figured out what was going on.
> 
> BTW, there's still an issue that a 'make clean' in the toplevel kernel
> dir will not clean up this feature dir, so if someone doesn't know to do
> 'cd tools/bpf && make clean' the main build may still break (I happened
> upon this because my main kernel build broke :/). Couldn't figure out
> how to convince make to fix that, so if you could take a look that would
> be great! :)

will check, thanks

jirka