From edf2cadf01e8f2620af25b337d15ebc584911b46 Mon Sep 17 00:00:00 2001 From: Blake Jones Date: Thu, 12 Jun 2025 12:49:39 -0700 Subject: [PATCH] perf test: add test for BPF metadata collection This is an end-to-end test for the PERF_RECORD_BPF_METADATA support. It adds a new "bpf_metadata_perf_version" variable to perf's BPF programs, so that when they are loaded, there will be at least one BPF program with some metadata to parse. The test invokes "perf record" in a way that loads one of those BPF programs, and then sifts through the output to find its BPF metadata. Signed-off-by: Blake Jones Link: https://lore.kernel.org/r/20250612194939.162730-6-blakejones@google.com Signed-off-by: Namhyung Kim --- tools/perf/Makefile.perf | 3 +- tools/perf/tests/shell/test_bpf_metadata.sh | 76 +++++++++++++++++++++ tools/perf/util/bpf_skel/perf_version.h | 17 +++++ 3 files changed, 95 insertions(+), 1 deletion(-) create mode 100755 tools/perf/tests/shell/test_bpf_metadata.sh create mode 100644 tools/perf/util/bpf_skel/perf_version.h diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf index d4c7031b01a7..4f292edeca5a 100644 --- a/tools/perf/Makefile.perf +++ b/tools/perf/Makefile.perf @@ -1250,8 +1250,9 @@ else $(Q)cp "$(VMLINUX_H)" $@ endif -$(SKEL_TMP_OUT)/%.bpf.o: util/bpf_skel/%.bpf.c $(LIBBPF) $(SKEL_OUT)/vmlinux.h | $(SKEL_TMP_OUT) +$(SKEL_TMP_OUT)/%.bpf.o: util/bpf_skel/%.bpf.c $(OUTPUT)PERF-VERSION-FILE util/bpf_skel/perf_version.h $(LIBBPF) $(SKEL_OUT)/vmlinux.h | $(SKEL_TMP_OUT) $(QUIET_CLANG)$(CLANG) -g -O2 --target=bpf $(CLANG_OPTIONS) $(BPF_INCLUDE) $(TOOLS_UAPI_INCLUDE) \ + -include $(OUTPUT)PERF-VERSION-FILE -include util/bpf_skel/perf_version.h \ -c $(filter util/bpf_skel/%.bpf.c,$^) -o $@ $(SKEL_OUT)/%.skel.h: $(SKEL_TMP_OUT)/%.bpf.o | $(BPFTOOL) diff --git a/tools/perf/tests/shell/test_bpf_metadata.sh b/tools/perf/tests/shell/test_bpf_metadata.sh new file mode 100755 index 000000000000..11df592fb661 --- /dev/null +++ b/tools/perf/tests/shell/test_bpf_metadata.sh @@ -0,0 +1,76 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# +# BPF metadata collection test. + +set -e + +err=0 +perfdata=$(mktemp /tmp/__perf_test.perf.data.XXXXX) + +cleanup() { + rm -f "${perfdata}" + rm -f "${perfdata}".old + trap - EXIT TERM INT +} + +trap_cleanup() { + cleanup + exit 1 +} +trap trap_cleanup EXIT TERM INT + +test_bpf_metadata() { + echo "Checking BPF metadata collection" + + if ! perf check -q feature libbpf-strings ; then + echo "Basic BPF metadata test [skipping - not supported]" + err=0 + return + fi + + # This is a basic invocation of perf record + # that invokes the perf_sample_filter BPF program. + if ! perf record -e task-clock --filter 'ip > 0' \ + -o "${perfdata}" sleep 1 2> /dev/null + then + echo "Basic BPF metadata test [Failed record]" + err=1 + return + fi + + # The BPF programs that ship with "perf" all have the following + # variable defined at compile time: + # + # const char bpf_metadata_perf_version[] SEC(".rodata") = <...>; + # + # This invocation looks for a PERF_RECORD_BPF_METADATA event, + # and checks that its content contains the string given by + # "perf version". + VERS=$(perf version | awk '{print $NF}') + if ! perf script --show-bpf-events -i "${perfdata}" | awk ' + /PERF_RECORD_BPF_METADATA.*perf_sample_filter/ { + header = 1; + } + /^ *entry/ { + if (header) { header = 0; entry = 1; } + } + $0 !~ /^ *entry/ { + entry = 0; + } + /perf_version/ { + if (entry) print $NF; + } + ' | egrep "$VERS" > /dev/null + then + echo "Basic BPF metadata test [Failed invalid output]" + err=1 + return + fi + echo "Basic BPF metadata test [Success]" +} + +test_bpf_metadata + +cleanup +exit $err diff --git a/tools/perf/util/bpf_skel/perf_version.h b/tools/perf/util/bpf_skel/perf_version.h new file mode 100644 index 000000000000..1ed5b2e59bf5 --- /dev/null +++ b/tools/perf/util/bpf_skel/perf_version.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */ + +#ifndef __PERF_VERSION_H__ +#define __PERF_VERSION_H__ + +#include "vmlinux.h" +#include + +/* + * This is used by tests/shell/record_bpf_metadata.sh + * to verify that BPF metadata generation works. + * + * PERF_VERSION is defined by a build rule at compile time. + */ +const char bpf_metadata_perf_version[] SEC(".rodata") = PERF_VERSION; + +#endif /* __PERF_VERSION_H__ */ -- 2.25.1