Re: [PATCH v2 3/4] bpftool: Add explicitly sequenced -lzstd to libbfd feature fallback

[Quentin Monnet <qmo@kernel.org>]

On 09/09/2026 21:41, Ian Rogers wrote:
> Distributions like Fedora currently ship a statically compiled binutils
> libbfd that natively depends on zstd to decompress sections (e.g.
> undefined reference to 'ZSTD_decompress').
> 
> Extend the newly supplemented libbfd-liberty-z-zstd feature probe into
> bpftool's Makefile so it can natively build against static binutils
> distributions.
> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> Assisted-by: Antigravity:gemini-3.1-pro
> ---
>  tools/bpf/bpftool/Makefile | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
> index b0f7168e7943..1cac4508eb0c 100644
> --- a/tools/bpf/bpftool/Makefile
> +++ b/tools/bpf/bpftool/Makefile
> @@ -125,6 +125,7 @@ FEATURE_TESTS += libcap
>  FEATURE_TESTS += libbfd
>  FEATURE_TESTS += libbfd-liberty
>  FEATURE_TESTS += libbfd-liberty-z
> +FEATURE_TESTS += libbfd-liberty-z-zstd
>  FEATURE_TESTS += disassembler-four-args
>  FEATURE_TESTS += disassembler-init-styled
>  FEATURE_TESTS += libelf-zstd
> @@ -135,6 +136,7 @@ FEATURE_DISPLAY += libcap
>  FEATURE_DISPLAY += libbfd
>  FEATURE_DISPLAY += libbfd-liberty
>  FEATURE_DISPLAY += libbfd-liberty-z
> +FEATURE_DISPLAY += libbfd-liberty-z-zstd
>  endif
>  
>  check_feat := 1
> @@ -201,6 +203,8 @@ else
>      LIBS += -lbfd -ldl -lopcodes -liberty
>    else ifeq ($(feature-libbfd-liberty-z),1)
>      LIBS += -lbfd -ldl -lopcodes -liberty -lz
> +  else ifeq ($(feature-libbfd-liberty-z-zstd),1)
> +    LIBS += -lbfd -ldl -lopcodes -liberty -lz -lzstd
>    endif
>  
>    # If one of the above feature combinations is set, we support libbfd


Hi Ian, thanks for this!

Just checking: my understanding is that if libbfd depends on libzstd,
then it always also depends on zlib, so we never need to check some
variant such as "feature-libbfd-liberty-zstd" (without the "-z"), is
this correct?

Quentin