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 <blakejones@google.com>
Link: https://lore.kernel.org/r/20250612194939.162730-6-blakejones@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

1 files changed, 76 insertions, 0 deletions

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