Re: [PATCH 1/4] selftests/bpf: Install bpftool where test_progs expects to find it

["Alexis Lothoré" <alexis.lothore@bootlin.com>]

Hi,

On Sat Jul 11, 2026 at 12:09 AM CEST, Ricardo B. Marlière wrote:
> bpftool_helpers.c looks for bpftool at "tools/sbin/bpftool" or
> "../tools/sbin/bpftool" relative to the running test_progs binary, matching
> the build directory layout where bpftool sits at
> $(OUTPUT)/tools/sbin/bpftool.
>
> INSTALL_RULE installs bpftool through the generic TEST_GEN_PROGS_EXTENDED
> mechanism, which flattens it straight into $(INSTALL_PATH) and loses the
> tools/sbin/ prefix. After "make install", every flavor of test_progs,
> including the default one, fails to locate bpftool, and bpftool_maps_access
> and bpftool_metadata error out with "Failed to detect bpftool path", even
> though bpftool itself built and installed fine.
>
> Explicitly install bpftool under tools/sbin/ in the installed tree
> so its relative location matches what detect_bpftool_path() already
> expects, restoring the pre-install layout instead of introducing a
> new one.
>
> Fixes: f21fae577446 ("selftests/bpf: Add a few helpers for bpftool testing")
> Signed-off-by: Ricardo B. Marlière <rbm@suse.com>

I did not face the issue because I am running the selftests in-tree, and
the CI seems to do the same, but for users using selftests after running
`make install`, I guess the change makes sense.

That's not the first fix aiming to improve bpftool
detection/installation (eg the BPFTOOL env variable, see [1]), so it
makes me wonder if we shouldn't just make bpftool part of
TRUNNER_EXTRA_FILES for all flavours of test_progs, similarly to other
binaries needed during tests (eg: urandom_read), instead of just adding
some bpftool-specific details in this generic install rule, and just
make the test runners assume that the needed binary is in the same
directory.

Alexis

[1] https://lore.kernel.org/all/20260223191118.655185-2-ihor.solodrai@linux.dev/

> ---
>  tools/testing/selftests/bpf/Makefile | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
> index b642ee489ea6..47911c9b4977 100644
> --- a/tools/testing/selftests/bpf/Makefile
> +++ b/tools/testing/selftests/bpf/Makefile
> @@ -1055,6 +1055,8 @@ endif
>  DEFAULT_INSTALL_RULE := $(INSTALL_RULE)
>  override define INSTALL_RULE
>  	$(DEFAULT_INSTALL_RULE)
> +	@mkdir -p $(INSTALL_PATH)/tools/sbin
> +	@rsync -a $(if $(PERMISSIVE),--ignore-missing-args) $(TRUNNER_BPFTOOL) $(INSTALL_PATH)/tools/sbin/
>  	@for DIR in $(TEST_INST_SUBDIRS); do				  \
>  		mkdir -p $(INSTALL_PATH)/$$DIR;				  \
>  		rsync -a $(if $(PERMISSIVE),--ignore-missing-args)	  \




-- 
Alexis Lothoré, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com