[PATCH v2 7/7] perf test: cs-etm: Test Coresight disassembly script

From: James Clark
Date: Thu Sep 12 2024 - 11:17:45 EST


Run a few samples through the disassembly script and check to see that
at least one branch instruction is printed.

Signed-off-by: James Clark <james.clark@xxxxxxxxxx>
---
.../tests/shell/test_arm_coresight_disasm.sh | 63 +++++++++++++++++++
1 file changed, 63 insertions(+)
create mode 100755 tools/perf/tests/shell/test_arm_coresight_disasm.sh

diff --git a/tools/perf/tests/shell/test_arm_coresight_disasm.sh b/tools/perf/tests/shell/test_arm_coresight_disasm.sh
new file mode 100755
index 000000000000..6d004bf29f80
--- /dev/null
+++ b/tools/perf/tests/shell/test_arm_coresight_disasm.sh
@@ -0,0 +1,63 @@
+#!/bin/sh
+# Check Arm CoreSight disassembly script completes without errors
+# SPDX-License-Identifier: GPL-2.0
+
+# The disassembly script reconstructs ranges of instructions and gives these to objdump to
+# decode. objdump doesn't like ranges that go backwards, but these are a good indication
+# that decoding has gone wrong either in OpenCSD, Perf or in the range reconstruction in
+# the script. Test all 3 parts are working correctly by running the script.
+
+skip_if_no_cs_etm_event() {
+ perf list | grep -q 'cs_etm//' && return 0
+
+ # cs_etm event doesn't exist
+ return 2
+}
+
+skip_if_no_cs_etm_event || exit 2
+
+# Assume an error unless we reach the very end
+set -e
+glb_err=1
+
+perfdata_dir=$(mktemp -d /tmp/__perf_test.perf.data.XXXXX)
+perfdata=${perfdata_dir}/perf.data
+file=$(mktemp /tmp/temporary_file.XXXXX)
+
+cleanup_files()
+{
+ set +e
+ rm -rf ${perfdata_dir}
+ rm -f ${file}
+ trap - EXIT TERM INT
+ exit $glb_err
+}
+
+trap cleanup_files EXIT TERM INT
+
+# Ranges start and end on branches, so check for some likely branch instructions
+sep="\s\|\s"
+branch_search="\sbl${sep}b${sep}b.ne${sep}b.eq${sep}cbz\s"
+
+## Test kernel ##
+if [ -e /proc/kcore ]; then
+ echo "Testing kernel disassembly"
+ perf record -o ${perfdata} -e cs_etm//k --kcore -- touch $file > /dev/null 2>&1
+ perf script -i ${perfdata} -s python:tools/perf/scripts/python/arm-cs-trace-disasm.py -- \
+ -d --stop-sample=30 2> /dev/null > ${file}
+ grep -q -e ${branch_search} ${file}
+ echo "Found kernel branches"
+else
+ # kcore is required for correct kernel decode due to runtime code patching
+ echo "No kcore, skipping kernel test"
+fi
+
+## Test user ##
+echo "Testing userspace disassembly"
+perf record -o ${perfdata} -e cs_etm//u -- touch $file > /dev/null 2>&1
+perf script -i ${perfdata} -s python:tools/perf/scripts/python/arm-cs-trace-disasm.py -- \
+ -d --stop-sample=30 2> /dev/null > ${file}
+grep -q -e ${branch_search} ${file}
+echo "Found userspace branches"
+
+glb_err=0
--
2.34.1