Commit edf2cadf authored by Blake Jones's avatar Blake Jones Committed by Namhyung Kim
Browse files

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: default avatarBlake Jones <blakejones@google.com>
Link: https://lore.kernel.org/r/20250612194939.162730-6-blakejones@google.com


Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
parent f19860ea

tools/perf/Makefile.perf

+2 −1
Original line number Diff line number Diff line
@@ -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)

tools/perf/tests/shell/test_bpf_metadata.sh

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#!/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

tools/perf/util/bpf_skel/perf_version.h

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/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */



#ifndef __PERF_VERSION_H__

#define __PERF_VERSION_H__



#include "vmlinux.h"

#include <bpf/bpf_helpers.h>



/*

 * 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__ */