BPF programs are useful in perf to profile BPF programs. BPF skeleton is by far the easiest way to write BPF tools. Enable building BPF skeletons in util/bpf_skel. A dummy bpf skeleton is added. More bpf skeletons will be added for different use cases.
Signed-off-by: Song Liu <[email protected]> --- tools/build/Makefile.feature | 3 +- tools/perf/Makefile.config | 7 +++ tools/perf/Makefile.perf | 15 +++++- tools/perf/util/bpf_skel/.gitignore | 3 ++ tools/perf/util/bpf_skel/Makefile | 71 ++++++++++++++++++++++++++++ tools/perf/util/bpf_skel/dummy.bpf.c | 19 ++++++++ 6 files changed, 115 insertions(+), 3 deletions(-) create mode 100644 tools/perf/util/bpf_skel/.gitignore create mode 100644 tools/perf/util/bpf_skel/Makefile create mode 100644 tools/perf/util/bpf_skel/dummy.bpf.c diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature index 97cbfb31b7625..95a58b5564218 100644 --- a/tools/build/Makefile.feature +++ b/tools/build/Makefile.feature @@ -70,7 +70,8 @@ FEATURE_TESTS_BASIC := \ libaio \ libzstd \ disassembler-four-args \ - file-handle + file-handle \ + clang-bpf-co-re # FEATURE_TESTS_BASIC + FEATURE_TESTS_EXTRA is the complete list # of all feature tests diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config index ce8516e4de34f..1c2c0f4badd85 100644 --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -619,6 +619,13 @@ ifndef NO_LIBBPF msg := $(warning BPF API too old. Please install recent kernel headers. BPF support in 'perf record' is disabled.) NO_LIBBPF := 1 endif + + ifndef NO_BPF_SKEL + ifeq ($(feature-clang-bpf-co-re), 1) + BUILD_BPF_SKEL := 1 + $(call detected,CONFIG_PERF_BPF_SKEL) + endif + endif endif dwarf-post-unwind := 1 diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf index 7ce3f2e8b9c74..9a9fc71e2ffa4 100644 --- a/tools/perf/Makefile.perf +++ b/tools/perf/Makefile.perf @@ -126,6 +126,8 @@ include ../scripts/utilities.mak # # Define NO_LIBDEBUGINFOD if you do not want support debuginfod # +# Define NO_BPF_SKEL if you do not want build BPF skeletons +# # As per kernel Makefile, avoid funny character set dependencies unexport LC_ALL @@ -735,7 +737,8 @@ prepare: $(OUTPUT)PERF-VERSION-FILE $(OUTPUT)common-cmds.h archheaders $(drm_ioc $(x86_arch_prctl_code_array) \ $(rename_flags_array) \ $(arch_errno_name_array) \ - $(sync_file_range_arrays) + $(sync_file_range_arrays) \ + bpf-skel $(OUTPUT)%.o: %.c prepare FORCE $(Q)$(MAKE) -f $(srctree)/tools/build/Makefile.build dir=$(build-dir) $@ @@ -1008,7 +1011,15 @@ config-clean: python-clean: $(python-clean) +ifdef BUILD_BPF_SKEL +bpf-skel: + $(Q)$(MAKE) -C util/bpf_skel +else +bpf-skel: +endif + clean:: $(LIBTRACEEVENT)-clean $(LIBAPI)-clean $(LIBBPF)-clean $(LIBSUBCMD)-clean $(LIBPERF)-clean config-clean fixdep-clean python-clean + $(call descend,util/bpf_skel,clean) $(call QUIET_CLEAN, core-objs) $(RM) $(LIBPERF_A) $(OUTPUT)perf-archive $(OUTPUT)perf-with-kcore $(LANG_BINDINGS) $(Q)find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.cmd' -delete -o -name '\.*.d' -delete $(Q)$(RM) $(OUTPUT).config-detected @@ -1071,7 +1082,7 @@ endif FORCE: -.PHONY: all install clean config-clean strip install-gtk +.PHONY: all install clean config-clean strip install-gtk bpf-skel .PHONY: shell_compatibility_test please_set_SHELL_PATH_to_a_more_modern_shell .PHONY: $(GIT-HEAD-PHONY) TAGS tags cscope FORCE prepare .PHONY: libtraceevent_plugins archheaders diff --git a/tools/perf/util/bpf_skel/.gitignore b/tools/perf/util/bpf_skel/.gitignore new file mode 100644 index 0000000000000..5263e9e6c5d83 --- /dev/null +++ b/tools/perf/util/bpf_skel/.gitignore @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0-only +.tmp +*.skel.h \ No newline at end of file diff --git a/tools/perf/util/bpf_skel/Makefile b/tools/perf/util/bpf_skel/Makefile new file mode 100644 index 0000000000000..853bece088f4b --- /dev/null +++ b/tools/perf/util/bpf_skel/Makefile @@ -0,0 +1,71 @@ +# SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) +SKEL_OUTPUT := $(abspath .) +TMP_OUTPUT := $(abspath .tmp) +CLANG ?= clang +LLC ?= llc +LLVM_STRIP ?= llvm-strip +DEFAULT_BPFTOOL := $(TMP_OUTPUT)/sbin/bpftool +BPFTOOL ?= $(DEFAULT_BPFTOOL) +LIBBPF_SRC := $(abspath ../../../lib/bpf) +BPFOBJ := $(TMP_OUTPUT)/libbpf.a +BPF_INCLUDE := $(TMP_OUTPUT) +INCLUDES := -I$(TMP_OUTPUT) -I$(BPF_INCLUDE) -I$(abspath ../../../lib) \ + -I$(abspath ../../../include/uapi) +CFLAGS := -g -Wall + +# Try to detect best kernel BTF source +KERNEL_REL := $(shell uname -r) +VMLINUX_BTF_PATHS := /sys/kernel/btf/vmlinux /boot/vmlinux-$(KERNEL_REL) +VMLINUX_BTF_PATH := $(or $(VMLINUX_BTF),$(firstword \ + $(wildcard $(VMLINUX_BTF_PATHS)))) +ifeq ($(V),1) +Q = +msg = +else +Q = @ +msg = @printf ' %-8s %s%s\n' "$(1)" "$(notdir $(2))" "$(if $(3), $(3))"; +MAKEFLAGS += --no-print-directory +submake_extras := feature_display=0 +endif + +SKELETONS := $(SKEL_OUTPUT)/dummy.skel.h + +.DELETE_ON_ERROR: + +.PHONY: all clean +all: $(SKELETONS) + +clean: + $(call msg,CLEAN,bpf_skel) + $(Q)rm -rf $(TMP_OUTPUT) $(SKELETONS) + +$(SKEL_OUTPUT)/%.skel.h: $(TMP_OUTPUT)/%.bpf.o | $(BPFTOOL) + $(call msg,GEN-SKEL,$@) + $(Q)$(BPFTOOL) gen skeleton $< > $@ + +$(TMP_OUTPUT)/%.bpf.o: %.bpf.c $(TMP_OUTPUT)/vmlinux.h $(BPFOBJ) | $(TMP_OUTPUT) + $(call msg,BPF,$@) + $(Q)$(CLANG) -g -O2 -target bpf $(INCLUDES) \ + -c $(filter %.c,$^) -o $@ && \ + $(LLVM_STRIP) -g $@ + +$(TMP_OUTPUT): + $(call msg,MKDIR,$@) + $(Q)mkdir -p $(TMP_OUTPUT) + +$(TMP_OUTPUT)/vmlinux.h: $(VMLINUX_BTF_PATH) | $(TMP_OUTPUT) $(BPFTOOL) + $(call msg,GEN,$@) + $(Q)if [ ! -e "$(VMLINUX_BTF_PATH)" ] ; then \ + echo "Couldn't find kernel BTF; set VMLINUX_BTF to" \ + "specify its location." >&2; \ + exit 1;\ + fi + $(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF_PATH) format c > $@ + +$(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(TMP_OUTPUT) + $(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC) \ + OUTPUT=$(abspath $(dir $@))/ $(abspath $@) + +$(DEFAULT_BPFTOOL): | $(TMP_OUTPUT) + $(Q)$(MAKE) $(submake_extras) -C ../../../bpf/bpftool \ + prefix= OUTPUT=$(TMP_OUTPUT)/ DESTDIR=$(TMP_OUTPUT) install diff --git a/tools/perf/util/bpf_skel/dummy.bpf.c b/tools/perf/util/bpf_skel/dummy.bpf.c new file mode 100644 index 0000000000000..085fcee1f52cf --- /dev/null +++ b/tools/perf/util/bpf_skel/dummy.bpf.c @@ -0,0 +1,19 @@ +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +// Copyright (c) 2020 Facebook +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> + +struct { + __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); + __uint(key_size, sizeof(u32)); + __uint(value_size, sizeof(u64)); +} counts SEC(".maps"); + +SEC("fentry/dummy") +int BPF_PROG(fentry_dummy) +{ + return 0; +} + +char LICENSE[] SEC("license") = "Dual BSD/GPL"; -- 2.24.1
