[for-next][PATCH 03/10] rtla: Add optional dependency on BPF tooling

Steven Rostedt
2025-03-06T18:18:24Z

If tooling required for building BPF CO-RE skeletons is present (that
is, libbpf, clang with BPF CO-RE support, and bpftool), turn on
HAVE_BPF_SKEL flag.

Those requirements are similar to what perf requires, with the
difference of using system libbpf and bpftool instead of in-tree
versions.

rtla can be forcefully built without BPF skeleton support by setting
BUILD_BPF_SKEL=0 manually; in that case, a warning is displayed.

Cc: John Kacur <jkacur@redhat.com>
Cc: Luis Goncalves <lgoncalv@redhat.com>
Cc: Gabriele Monaco <gmonaco@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Link: https://lore.kernel.org/20250218145859.27762-4-tglozar@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
tools/tracing/rtla/Makefile | 6 +++++
tools/tracing/rtla/Makefile.config | 42 ++++++++++++++++++++++++++++++
2 files changed, 48 insertions(+)

diff --git a/tools/tracing/rtla/Makefile b/tools/tracing/rtla/Makefile
index 8b5101457c70..0aa116f7b355 100644
--- a/tools/tracing/rtla/Makefile
+++ b/tools/tracing/rtla/Makefile
@@ -33,9 +33,15 @@ DOCSRC := ../../../Documentation/tools/rtla/
FEATURE_TESTS := libtraceevent
FEATURE_TESTS += libtracefs
FEATURE_TESTS += libcpupower
+FEATURE_TESTS += libbpf
+FEATURE_TESTS += clang-bpf-co-re
+FEATURE_TESTS += bpftool-skeletons
FEATURE_DISPLAY := libtraceevent
FEATURE_DISPLAY += libtracefs
FEATURE_DISPLAY += libcpupower
+FEATURE_DISPLAY += libbpf
+FEATURE_DISPLAY += clang-bpf-co-re
+FEATURE_DISPLAY += bpftool-skeletons

ifeq ($(V),1)
Q =
diff --git a/tools/tracing/rtla/Makefile.config b/tools/tracing/rtla/Makefile.config
index 92a6e12e42d3..5f2231d8d626 100644
--- a/tools/tracing/rtla/Makefile.config
+++ b/tools/tracing/rtla/Makefile.config
@@ -53,6 +53,48 @@ else
$(info Please install libcpupower-dev/kernel-tools-libs-devel)
endif

+ifndef BUILD_BPF_SKEL
+ # BPF skeletons are used to implement improved sample collection, enable
+ # them by default.
+ BUILD_BPF_SKEL := 1
+endif
+
+ifeq ($(BUILD_BPF_SKEL),0)
+ $(info BPF skeleton support disabled, building without BPF skeleton support.)
+endif
+
+$(call feature_check,libbpf)
+ifeq ($(feature-libbpf), 1)
+ $(call detected,CONFIG_LIBBPF)
+else
+ $(info libbpf is missing, building without BPF skeleton support.)
+ $(info Please install libbpf-dev/libbpf-devel)
+ BUILD_BPF_SKEL := 0
+endif
+
+$(call feature_check,clang-bpf-co-re)
+ifeq ($(feature-clang-bpf-co-re), 1)
+ $(call detected,CONFIG_CLANG_BPF_CO_RE)
+else
+ $(info clang is missing or does not support BPF CO-RE, building without BPF skeleton support.)
+ $(info Please install clang)
+ BUILD_BPF_SKEL := 0
+endif
+
+$(call feature_check,bpftool-skeletons)
+ifeq ($(feature-bpftool-skeletons), 1)
+ $(call detected,CONFIG_BPFTOOL_SKELETONS)
+else
+ $(info bpftool is missing or not supporting skeletons, building without BPF skeleton support.)
+ $(info Please install bpftool)
+ BUILD_BPF_SKEL := 0
+endif
+
+ifeq ($(BUILD_BPF_SKEL),1)
+ CFLAGS += -DHAVE_BPF_SKEL
+ EXTLIBS += -lbpf
+endif
+
ifeq ($(STOP_ERROR),1)
$(error Please, check the errors above.)
endif
--
2.47.2