tools/build: Use SYSTEM_BPFTOOL for system bpftool

The feature test for system bpftool uses BPFTOOL as the variable to set
its path, defaulting to just "bpftool" if not set by the user.

This conflicts with selftests and a few other utilities, which expect
BPFTOOL to be set to the in-tree bpftool path by default. For example,
bpftool selftests fail to build:

$ make -C tools/testing/selftests/bpf/
make: Entering directory '/home/tglozar/dev/linux/tools/testing/selftests/bpf'

make: *** No rule to make target 'bpftool', needed by '/home/tglozar/dev/linux/tools/testing/selftests/bpf/tools/include/vmlinux.h'.  Stop.
make: Leaving directory '/home/tglozar/dev/linux/tools/testing/selftests/bpf'

Fix the problem by renaming the variable used for system bpftool from
BPFTOOL to SYSTEM_BPFTOOL, so that the new usage does not conflict with
the existing one of BPFTOOL.

Cc: John Kacur <jkacur@redhat.com>
Cc: Luis Goncalves <lgoncalv@redhat.com>
Link: https://lore.kernel.org/20250326004018.248357-1-tglozar@redhat.com
Fixes: 8a635c3856dd ("tools/build: Add bpftool-skeletons feature test")
Closes: https://lore.kernel.org/linux-kernel/5df6968a-2e5f-468e-b457-fc201535dd4c@linux.ibm.com/
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Suggested-by: Quentin Monnet <qmo@kernel.org>
Acked-by: Quentin Monnet <qmo@kernel.org>
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
index 4f9c1d950f5db5b3afab442f4823e3461d2d1b89..b8b5fb183dd406938b118e0dd88d42f61ce98084 100644 (file)
--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -419,7 +419,7 @@ $(OUTPUT)test-libpfm4.bin:
        $(BUILD) -lpfm
 
 $(OUTPUT)test-bpftool-skeletons.bin:
-       $(BPFTOOL) version | grep '^features:.*skeletons' \
+       $(SYSTEM_BPFTOOL) version | grep '^features:.*skeletons' \
                > $(@:.bin=.make.output) 2>&1
 ###############################
 

diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include
index 71bbe52721b35fdaada3b1d9cec73fd0015a9207..34a33c1ad96cf944a960f399bf5541d4aca387e9 100644 (file)
--- a/tools/scripts/Makefile.include
+++ b/tools/scripts/Makefile.include
@@ -92,7 +92,7 @@ LLVM_OBJCOPY  ?= llvm-objcopy
 LLVM_STRIP     ?= llvm-strip
 
 # Some tools require bpftool
-BPFTOOL                ?= bpftool
+SYSTEM_BPFTOOL ?= bpftool
 
 ifeq ($(CC_NO_CLANG), 1)
 EXTRA_WARNINGS += -Wstrict-aliasing=3

diff --git a/tools/tracing/rtla/Makefile b/tools/tracing/rtla/Makefile
index 557af322be6106282e8004b57a8164130c8dbe57..3dc050317b9d4fc0ee5a09c047caa3c6f24defb6 100644 (file)
--- a/tools/tracing/rtla/Makefile
+++ b/tools/tracing/rtla/Makefile
@@ -78,7 +78,7 @@ src/timerlat.bpf.o: src/timerlat.bpf.c
        $(QUIET_CLANG)$(CLANG) -g -O2 -target bpf -c $(filter %.c,$^) -o $@
 
 src/timerlat.skel.h: src/timerlat.bpf.o
-       $(QUIET_GENSKEL)$(BPFTOOL) gen skeleton $< > $@
+       $(QUIET_GENSKEL)$(SYSTEM_BPFTOOL) gen skeleton $< > $@
 else
 src/timerlat.skel.h:
        $(Q)echo '/* BPF skeleton is disabled */' > src/timerlat.skel.h