perf intel-pt: Add a test for system-wide side band

Add a test for system-wide side band even when tracing selected CPUs.

The test fails before the patches up to "perf tools: Allow system-wide
events to keep their own CPUs" are applied, passes afterwards.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Ian Rogers <irogers@google.com>
Acked-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Link: https://lore.kernel.org/r/20220524075436.29144-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/shell/test_intel_pt.sh

@@ -0,0 +1,71 @@
+#!/bin/sh
+# Miscellaneous Intel PT testing
+# SPDX-License-Identifier: GPL-2.0
+
+set -e
+
+# Skip if no Intel PT
+perf list | grep -q 'intel_pt//' || exit 2
+
+skip_cnt=0
+ok_cnt=0
+err_cnt=0
+
+tmpfile=`mktemp`
+perfdatafile=`mktemp`
+
+can_cpu_wide()
+{
+	perf record -o ${tmpfile} -B -N --no-bpf-event -e dummy:u -C $1 true 2>&1 >/dev/null || return 2
+	return 0
+}
+
+test_system_wide_side_band()
+{
+	# Need CPU 0 and CPU 1
+	can_cpu_wide 0 || return $?
+	can_cpu_wide 1 || return $?
+
+	# Record on CPU 0 a task running on CPU 1
+	perf record -B -N --no-bpf-event -o ${perfdatafile} -e intel_pt//u -C 0 -- taskset --cpu-list 1 uname
+
+	# Should get MMAP events from CPU 1 because they can be needed to decode
+	mmap_cnt=`perf script -i ${perfdatafile} --no-itrace --show-mmap-events -C 1 2>/dev/null | grep MMAP | wc -l`
+
+	if [ ${mmap_cnt} -gt 0 ] ; then
+		return 0
+	fi
+
+	echo "Failed to record MMAP events on CPU 1 when tracing CPU 0"
+	return 1
+}
+
+count_result()
+{
+	if [ $1 -eq 2 ] ; then
+		skip_cnt=`expr ${skip_cnt} \+ 1`
+		return
+	fi
+	if [ $1 -eq 0 ] ; then
+		ok_cnt=`expr ${ok_cnt} \+ 1`
+		return
+	fi
+	err_cnt=`expr ${err_cnt} \+ 1`
+}
+
+test_system_wide_side_band
+
+count_result $?
+
+rm -f ${tmpfile}
+rm -f ${perfdatafile}
+
+if [ ${err_cnt} -gt 0 ] ; then
+	exit 1
+fi
+
+if [ ${ok_cnt} -gt 0 ] ; then
+	exit 0
+fi
+
+exit 2