diff options
| author | Yonghong Song <yhs@fb.com> | 2022-02-05 00:43:55 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-13 21:59:03 +0300 |
| commit | e9da1df2c021642a0541eaf2add19dbe0d9e7685 (patch) | |
| tree | 6babb740c8f340e3c4fa8263631c2fa250f15167 /tools | |
| parent | 19d067c10b7157fc006be1ce0e770ba300642415 (diff) | |
| download | linux-e9da1df2c021642a0541eaf2add19dbe0d9e7685.tar.xz | |
libbpf: Fix build issue with llvm-readelf
[ Upstream commit 0908a66ad1124c1634c33847ac662106f7f2c198 ]
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.
The proposed fix filters out all ABS symbols as they are not part of the comparison.
This works for both binutils readelf and llvm-readelf.
Reported-by: Delyan Kratunov <delyank@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220204214355.502108-1-yhs@fb.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/lib/bpf/Makefile | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile index 74c3b73a5fbe..089b73b3cb37 100644 --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -126,7 +126,7 @@ GLOBAL_SYM_COUNT = $(shell readelf -s --wide $(BPF_IN_SHARED) | \ sort -u | wc -l) VERSIONED_SYM_COUNT = $(shell readelf --dyn-syms --wide $(OUTPUT)libbpf.so | \ sed 's/\[.*\]//' | \ - awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}' | \ + awk '/GLOBAL/ && /DEFAULT/ && !/UND|ABS/ {print $$NF}' | \ grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | sort -u | wc -l) CMD_TARGETS = $(LIB_TARGET) $(PC_FILE) @@ -195,7 +195,7 @@ check_abi: $(OUTPUT)libbpf.so $(VERSION_SCRIPT) sort -u > $(OUTPUT)libbpf_global_syms.tmp; \ readelf --dyn-syms --wide $(OUTPUT)libbpf.so | \ sed 's/\[.*\]//' | \ - awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}'| \ + awk '/GLOBAL/ && /DEFAULT/ && !/UND|ABS/ {print $$NF}'| \ grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | \ sort -u > $(OUTPUT)libbpf_versioned_syms.tmp; \ diff -u $(OUTPUT)libbpf_global_syms.tmp \ |