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

["Ricardo B. Marlière" <rbm@suse.com>]

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>
---
 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)	  \

-- 
2.54.0