Re: [PATCH] libbpf: don't preserve ownership during install

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The use of the GNU-specific `cp --preserve` extension breaks `make install` on platforms with BSD or BusyBox `cp` implementations (e.g., macOS, FreeBSD, Alpine).
--

--- Patch [1]: [PATCH] libbpf: don't preserve ownership during install ---
commit 20b6f948388a1067581300a57d47fc33d1950c11
Author: Martin Kaiser <martin@kaiser.cx>

libbpf: don't preserve ownership during install

This commit modifies the libbpf install_lib target in the Makefile to
prevent leaking the source tree owner's UID into the root filesystem. It
replaces the cp -p flag with the --preserve=mode,timestamps flag to only
preserve specific file attributes during installation.

> diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
> --- a/tools/lib/bpf/Makefile
> +++ b/tools/lib/bpf/Makefile
> @@ -231,7 +231,7 @@ endef
>  install_lib: all_cmd
>  	$(call QUIET_INSTALL, $(LIB_TARGET)) \
>  		$(call do_install_mkdir,$(libdir_SQ)); \
> -		cp -fpR $(LIB_FILE) $(DESTDIR)$(libdir_SQ)
> +		cp -fR --preserve=mode,timestamps $(LIB_FILE) $(DESTDIR)$(libdir_SQ)

[Severity: Medium]
Will this break the installation process on platforms that do not use GNU
coreutils?

The --preserve argument is a GNU-specific extension. It appears this might
cause the make install target to fail with an unrecognized option error on
systems relying on BSD or BusyBox implementations of cp, such as macOS,
FreeBSD, or Alpine Linux.

[ ... ]

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Sashiko AI review · https://sashiko.dev/#/patchset/20260728071516.2706695-1-martin@kaiser.cx?part=1