On Fri, Dec 18, 2015 at 01:59:20PM -0700, Mathieu Poirier wrote:

+struct auxtrace_record
+*auxtrace_record__init(struct perf_evlist *evlist, int *err)
+{
+	struct perf_pmu	*cs_etm_pmu;
+	struct perf_evsel *evsel;
+	bool found_etm = false;
+
+	cs_etm_pmu = perf_pmu__find(CORESIGHT_ETM_PMU_NAME);
+
+	 if (evlist) {
+		evlist__for_each(evlist, evsel) {
+			if (cs_etm_pmu &&
+			    evsel->attr.type == cs_etm_pmu->type)
+				found_etm = true;
+		}
+	}
+
+	if (found_etm)
+		return cs_etm_record_init(err);
+
+	*err = -EINVAL;

This should not set an error code when found_etm is false.  Otherwise
any attempt to uses perf record without a cs_etm event enabled errors
out.

+	return NULL;
+}