@@ -680,6 +680,10 @@ ifdef BUILD_BPF_SKEL
CFLAGS += -DHAVE_BPF_SKEL
endif
+ifndef GEN_VMLINUX_H
+ VMLINUX_H=$(src-perf)/util/bpf_skel/vmlinux/vmlinux.h
+endif
+
dwarf-post-unwind := 1
dwarf-post-unwind-text := BUG
@@ -1080,7 +1080,21 @@ $(BPFTOOL): | $(SKEL_TMP_OUT)
$(Q)CFLAGS= $(MAKE) -C ../bpf/bpftool \
OUTPUT=$(SKEL_TMP_OUT)/ bootstrap
-$(SKEL_TMP_OUT)/%.bpf.o: util/bpf_skel/%.bpf.c $(LIBBPF) | $(SKEL_TMP_OUT)
+VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux) \
+ $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux) \
+ ../../vmlinux \
+ /sys/kernel/btf/vmlinux \
+ /boot/vmlinux-$(shell uname -r)
+VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
+
+$(SKEL_OUT)/vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL)
+ifeq ($(VMLINUX_H),)
+ $(QUIET_GEN)$(BPFTOOL) btf dump file $< format c > $@
+else
+ $(Q)cp "$(VMLINUX_H)" $@
+endif
+
+$(SKEL_TMP_OUT)/%.bpf.o: util/bpf_skel/%.bpf.c $(LIBBPF) $(SKEL_OUT)/vmlinux.h | $(SKEL_TMP_OUT)
$(QUIET_CLANG)$(CLANG) -g -O2 -target bpf -Wall -Werror $(BPF_INCLUDE) $(TOOLS_UAPI_INCLUDE) \
-c $(filter util/bpf_skel/%.bpf.c,$^) -o $@
@@ -1,3 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
.tmp
*.skel.h
+vmlinux.h
similarity index 100%
rename from tools/perf/util/bpf_skel/vmlinux.h
rename to tools/perf/util/bpf_skel/vmlinux/vmlinux.h
Commit a887466562b4 ("perf bpf skels: Stop using vmlinux.h generated from BTF, use subset of used structs + CO-RE") made it so that vmlinux.h was uncondtionally included from tools/perf/util/vmlinux.h. This change reverts part of that change (so that vmlinux.h is once again generated) and makes it so that the vmlinux.h used at build time is selected from the VMLINUX_H variable. By default the VMLINUX_H variable is set to the vmlinux.h added in change a887466562b4, but if GEN_VMLINUX_H=1 is passed on the build command line then the previous generation behavior kicks in. The build with GEN_VMLINUX_H=1 currently fails with: ``` util/bpf_skel/lock_contention.bpf.c:419:8: error: redefinition of 'rq' struct rq {}; ^ /tmp/perf/util/bpf_skel/.tmp/../vmlinux.h:45630:8: note: previous definition is here struct rq { ^ 1 error generated. ``` Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> --- tools/perf/Makefile.config | 4 ++++ tools/perf/Makefile.perf | 16 +++++++++++++++- tools/perf/util/bpf_skel/.gitignore | 1 + tools/perf/util/bpf_skel/{ => vmlinux}/vmlinux.h | 0 4 files changed, 20 insertions(+), 1 deletion(-) rename tools/perf/util/bpf_skel/{ => vmlinux}/vmlinux.h (100%)