From b7a2d774c9c5a9a3228c6169ecf32f05b96609cf Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Thu, 22 Jun 2023 21:14:02 -0700 Subject: [PATCH] perf build: Add ability to build with a generated 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 Acked-by: Andrii Nakryiko Acked-by: Namhyung Kim Acked-by: Jiri Olsa Cc: James Clark Cc: Mark Rutland Cc: Yang Jihong Cc: Peter Zijlstra Cc: Adrian Hunter Cc: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Tiezhu Yang Cc: Ingo Molnar Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20230623041405.4039475-2-irogers@google.com [ Format the error message and add a comment for GEN_VMLINUX_H ] Signed-off-by: Namhyung Kim --- tools/perf/Makefile.config | 4 ++++ tools/perf/Makefile.perf | 18 +++++++++++++++++- tools/perf/util/bpf_skel/.gitignore | 1 + .../perf/util/bpf_skel/{ => vmlinux}/vmlinux.h | 0 4 files changed, 22 insertions(+), 1 deletion(-) rename tools/perf/util/bpf_skel/{ => vmlinux}/vmlinux.h (100%) diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config index 9c5aa14a44cf4..78411252b72a8 100644 --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -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 diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf index b1e62a621f92a..a49eded5cc4f9 100644 --- a/tools/perf/Makefile.perf +++ b/tools/perf/Makefile.perf @@ -132,6 +132,8 @@ include ../scripts/utilities.mak # Define EXTRA_TESTS to enable building extra tests useful mainly to perf # developers, such as: # x86 instruction decoder - new instructions test +# +# Define GEN_VMLINUX_H to generate vmlinux.h from the BTF. # As per kernel Makefile, avoid funny character set dependencies unexport LC_ALL @@ -1084,7 +1086,21 @@ $(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 $@ diff --git a/tools/perf/util/bpf_skel/.gitignore b/tools/perf/util/bpf_skel/.gitignore index 7a1c832825de8..cd01455e1b53c 100644 --- a/tools/perf/util/bpf_skel/.gitignore +++ b/tools/perf/util/bpf_skel/.gitignore @@ -1,3 +1,4 @@ # SPDX-License-Identifier: GPL-2.0-only .tmp *.skel.h +vmlinux.h diff --git a/tools/perf/util/bpf_skel/vmlinux.h b/tools/perf/util/bpf_skel/vmlinux/vmlinux.h similarity index 100% rename from tools/perf/util/bpf_skel/vmlinux.h rename to tools/perf/util/bpf_skel/vmlinux/vmlinux.h