| Message ID | 20220204211302.302066-1-yhs@fb.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | BPF |
| Headers | show |
| Series | [bpf-next] libbpf: fix build issue with llvm-readelf | expand |
On Fri, Feb 4, 2022 at 1:13 PM Yonghong Song <yhs@fb.com> wrote: > > There are cases where clang compiler is packaged in a way > readelf is a symbolic link to llvm-readelf. In such cases, > llvm-readelf will be used instead of default binutils readelf, > and the following error will appear during libbpf build: > > Warning: Num of global symbols in > /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/libbpf-in.o (367) > does NOT match with num of versioned symbols in > /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf.so libbpf.map (383). > Please make sure all LIBBPF_API symbols are versioned in libbpf.map. > --- /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf_global_syms.tmp ... > +++ /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf_versioned_syms.tmp ... > @@ -324,6 +324,22 @@ > btf__str_by_offset > btf__type_by_id > btf__type_cnt > +LIBBPF_0.0.1 > +LIBBPF_0.0.2 > +LIBBPF_0.0.3 > +LIBBPF_0.0.4 > +LIBBPF_0.0.5 > +LIBBPF_0.0.6 > +LIBBPF_0.0.7 > +LIBBPF_0.0.8 > +LIBBPF_0.0.9 > +LIBBPF_0.1.0 > +LIBBPF_0.2.0 > +LIBBPF_0.3.0 > +LIBBPF_0.4.0 > +LIBBPF_0.5.0 > +LIBBPF_0.6.0 > +LIBBPF_0.7.0 > libbpf_attach_type_by_name > libbpf_find_kernel_btf > libbpf_find_vmlinux_btf_id > make[2]: *** [Makefile:184: check_abi] Error 1 > make[1]: *** [Makefile:140: all] Error 2 > > The above failure is due to different printouts for some ABS > versioned symbols. For example, with the same libbpf.so, > $ /bin/readelf --dyn-syms --wide tools/lib/bpf/libbpf.so | grep "LIBBPF" | grep ABS > 134: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.5.0 > 202: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.6.0 > ... > $ /opt/llvm/bin/readelf --dyn-syms --wide tools/lib/bpf/libbpf.so | grep "LIBBPF" | grep ABS > 134: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.5.0@@LIBBPF_0.5.0 > 202: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.6.0@@LIBBPF_0.6.0 > ... > The binutils readelf doesn't print out the symbol LIBBPF_* version and llvm-readelf does. > Such a difference caused libbpf build failure with llvm-readelf. > > To fix the issue, let us do proper filtering for LIBBPF_*@@LIBBPF_* symbols. > The proposed fix works for both binutils readelf and llvm-readelf. > > Reported-by: Delyan Kratunov <delyank@fb.com> > Signed-off-by: Yonghong Song <yhs@fb.com> > --- > tools/lib/bpf/Makefile | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile > index f947b61b2107..d1577c26c16b 100644 > --- a/tools/lib/bpf/Makefile > +++ b/tools/lib/bpf/Makefile > @@ -132,7 +132,8 @@ GLOBAL_SYM_COUNT = $(shell readelf -s --wide $(BPF_IN_SHARED) | \ > VERSIONED_SYM_COUNT = $(shell readelf --dyn-syms --wide $(OUTPUT)libbpf.so | \ > sed 's/\[.*\]//' | \ > awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}' | \ have you tried just doing !/UND|ABS/ here? > - grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | sort -u | wc -l) > + grep -Eo '[^ ]+@LIBBPF_' | grep -Ev '^LIBBPF_' | \ > + cut -d@ -f1 | sort -u | wc -l) > > CMD_TARGETS = $(LIB_TARGET) $(PC_FILE) > > @@ -195,7 +196,8 @@ check_abi: $(OUTPUT)libbpf.so $(VERSION_SCRIPT) > readelf --dyn-syms --wide $(OUTPUT)libbpf.so | \ > sed 's/\[.*\]//' | \ > awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}'| \ > - grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | \ > + grep -Eo '[^ ]+@LIBBPF_' | grep -Ev '^LIBBPF_' | \ > + cut -d@ -f1 | \ > sort -u > $(OUTPUT)libbpf_versioned_syms.tmp; \ > diff -u $(OUTPUT)libbpf_global_syms.tmp \ > $(OUTPUT)libbpf_versioned_syms.tmp; \ > -- > 2.30.2 >
On 2/4/22 1:31 PM, Andrii Nakryiko wrote: > On Fri, Feb 4, 2022 at 1:13 PM Yonghong Song <yhs@fb.com> wrote: >> >> There are cases where clang compiler is packaged in a way >> readelf is a symbolic link to llvm-readelf. In such cases, >> llvm-readelf will be used instead of default binutils readelf, >> and the following error will appear during libbpf build: >> >> Warning: Num of global symbols in >> /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/libbpf-in.o (367) >> does NOT match with num of versioned symbols in >> /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf.so libbpf.map (383). >> Please make sure all LIBBPF_API symbols are versioned in libbpf.map. >> --- /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf_global_syms.tmp ... >> +++ /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf_versioned_syms.tmp ... >> @@ -324,6 +324,22 @@ >> btf__str_by_offset >> btf__type_by_id >> btf__type_cnt >> +LIBBPF_0.0.1 >> +LIBBPF_0.0.2 >> +LIBBPF_0.0.3 >> +LIBBPF_0.0.4 >> +LIBBPF_0.0.5 >> +LIBBPF_0.0.6 >> +LIBBPF_0.0.7 >> +LIBBPF_0.0.8 >> +LIBBPF_0.0.9 >> +LIBBPF_0.1.0 >> +LIBBPF_0.2.0 >> +LIBBPF_0.3.0 >> +LIBBPF_0.4.0 >> +LIBBPF_0.5.0 >> +LIBBPF_0.6.0 >> +LIBBPF_0.7.0 >> libbpf_attach_type_by_name >> libbpf_find_kernel_btf >> libbpf_find_vmlinux_btf_id >> make[2]: *** [Makefile:184: check_abi] Error 1 >> make[1]: *** [Makefile:140: all] Error 2 >> >> The above failure is due to different printouts for some ABS >> versioned symbols. For example, with the same libbpf.so, >> $ /bin/readelf --dyn-syms --wide tools/lib/bpf/libbpf.so | grep "LIBBPF" | grep ABS >> 134: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.5.0 >> 202: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.6.0 >> ... >> $ /opt/llvm/bin/readelf --dyn-syms --wide tools/lib/bpf/libbpf.so | grep "LIBBPF" | grep ABS >> 134: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.5.0@@LIBBPF_0.5.0 >> 202: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.6.0@@LIBBPF_0.6.0 >> ... >> The binutils readelf doesn't print out the symbol LIBBPF_* version and llvm-readelf does. >> Such a difference caused libbpf build failure with llvm-readelf. >> >> To fix the issue, let us do proper filtering for LIBBPF_*@@LIBBPF_* symbols. >> The proposed fix works for both binutils readelf and llvm-readelf. >> >> Reported-by: Delyan Kratunov <delyank@fb.com> >> Signed-off-by: Yonghong Song <yhs@fb.com> >> --- >> tools/lib/bpf/Makefile | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile >> index f947b61b2107..d1577c26c16b 100644 >> --- a/tools/lib/bpf/Makefile >> +++ b/tools/lib/bpf/Makefile >> @@ -132,7 +132,8 @@ GLOBAL_SYM_COUNT = $(shell readelf -s --wide $(BPF_IN_SHARED) | \ >> VERSIONED_SYM_COUNT = $(shell readelf --dyn-syms --wide $(OUTPUT)libbpf.so | \ >> sed 's/\[.*\]//' | \ >> awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}' | \ > > have you tried just doing !/UND|ABS/ here? It works and even simpler. Thanks for suggestion. Will send v2. > >> - grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | sort -u | wc -l) >> + grep -Eo '[^ ]+@LIBBPF_' | grep -Ev '^LIBBPF_' | \ >> + cut -d@ -f1 | sort -u | wc -l) >> >> CMD_TARGETS = $(LIB_TARGET) $(PC_FILE) >> >> @@ -195,7 +196,8 @@ check_abi: $(OUTPUT)libbpf.so $(VERSION_SCRIPT) >> readelf --dyn-syms --wide $(OUTPUT)libbpf.so | \ >> sed 's/\[.*\]//' | \ >> awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}'| \ >> - grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | \ >> + grep -Eo '[^ ]+@LIBBPF_' | grep -Ev '^LIBBPF_' | \ >> + cut -d@ -f1 | \ >> sort -u > $(OUTPUT)libbpf_versioned_syms.tmp; \ >> diff -u $(OUTPUT)libbpf_global_syms.tmp \ >> $(OUTPUT)libbpf_versioned_syms.tmp; \ >> -- >> 2.30.2 >>
diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile index f947b61b2107..d1577c26c16b 100644 --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -132,7 +132,8 @@ GLOBAL_SYM_COUNT = $(shell readelf -s --wide $(BPF_IN_SHARED) | \ VERSIONED_SYM_COUNT = $(shell readelf --dyn-syms --wide $(OUTPUT)libbpf.so | \ sed 's/\[.*\]//' | \ awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}' | \ - grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | sort -u | wc -l) + grep -Eo '[^ ]+@LIBBPF_' | grep -Ev '^LIBBPF_' | \ + cut -d@ -f1 | sort -u | wc -l) CMD_TARGETS = $(LIB_TARGET) $(PC_FILE) @@ -195,7 +196,8 @@ check_abi: $(OUTPUT)libbpf.so $(VERSION_SCRIPT) readelf --dyn-syms --wide $(OUTPUT)libbpf.so | \ sed 's/\[.*\]//' | \ awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}'| \ - grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | \ + grep -Eo '[^ ]+@LIBBPF_' | grep -Ev '^LIBBPF_' | \ + cut -d@ -f1 | \ sort -u > $(OUTPUT)libbpf_versioned_syms.tmp; \ diff -u $(OUTPUT)libbpf_global_syms.tmp \ $(OUTPUT)libbpf_versioned_syms.tmp; \
There are cases where clang compiler is packaged in a way readelf is a symbolic link to llvm-readelf. In such cases, llvm-readelf will be used instead of default binutils readelf, and the following error will appear during libbpf build: Warning: Num of global symbols in /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/libbpf-in.o (367) does NOT match with num of versioned symbols in /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf.so libbpf.map (383). Please make sure all LIBBPF_API symbols are versioned in libbpf.map. --- /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf_global_syms.tmp ... +++ /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf_versioned_syms.tmp ... @@ -324,6 +324,22 @@ btf__str_by_offset btf__type_by_id btf__type_cnt +LIBBPF_0.0.1 +LIBBPF_0.0.2 +LIBBPF_0.0.3 +LIBBPF_0.0.4 +LIBBPF_0.0.5 +LIBBPF_0.0.6 +LIBBPF_0.0.7 +LIBBPF_0.0.8 +LIBBPF_0.0.9 +LIBBPF_0.1.0 +LIBBPF_0.2.0 +LIBBPF_0.3.0 +LIBBPF_0.4.0 +LIBBPF_0.5.0 +LIBBPF_0.6.0 +LIBBPF_0.7.0 libbpf_attach_type_by_name libbpf_find_kernel_btf libbpf_find_vmlinux_btf_id make[2]: *** [Makefile:184: check_abi] Error 1 make[1]: *** [Makefile:140: all] Error 2 The above failure is due to different printouts for some ABS versioned symbols. For example, with the same libbpf.so, $ /bin/readelf --dyn-syms --wide tools/lib/bpf/libbpf.so | grep "LIBBPF" | grep ABS 134: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.5.0 202: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.6.0 ... $ /opt/llvm/bin/readelf --dyn-syms --wide tools/lib/bpf/libbpf.so | grep "LIBBPF" | grep ABS 134: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.5.0@@LIBBPF_0.5.0 202: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.6.0@@LIBBPF_0.6.0 ... The binutils readelf doesn't print out the symbol LIBBPF_* version and llvm-readelf does. Such a difference caused libbpf build failure with llvm-readelf. To fix the issue, let us do proper filtering for LIBBPF_*@@LIBBPF_* symbols. The proposed fix works for both binutils readelf and llvm-readelf. Reported-by: Delyan Kratunov <delyank@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> --- tools/lib/bpf/Makefile | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)