libperf: Add perf_evsel__attr() function

Add a perf_evsel__attr() function to get attr pointer from a perf_evsel
instance.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190721112506.12306-71-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/lib/evsel.c

@@ -225,3 +225,8 @@ struct perf_thread_map *perf_evsel__threads(struct perf_evsel *evsel)
 {
 	return evsel->threads;
 }
+
+struct perf_event_attr *perf_evsel__attr(struct perf_evsel *evsel)
+{
+	return &evsel->attr;
+}

tools/perf/lib/include/perf/evsel.h

@@ -34,5 +34,6 @@ LIBPERF_API int perf_evsel__enable(struct perf_evsel *evsel);
 LIBPERF_API int perf_evsel__disable(struct perf_evsel *evsel);
 LIBPERF_API struct perf_cpu_map *perf_evsel__cpus(struct perf_evsel *evsel);
 LIBPERF_API struct perf_thread_map *perf_evsel__threads(struct perf_evsel *evsel);
+LIBPERF_API struct perf_event_attr *perf_evsel__attr(struct perf_evsel *evsel);
 
 #endif /* __LIBPERF_EVSEL_H */

tools/perf/lib/libperf.map

@@ -23,6 +23,7 @@ LIBPERF_0.0.1 {
 		perf_evsel__read;
 		perf_evsel__cpus;
 		perf_evsel__threads;
+		perf_evsel__attr;
 		perf_evlist__new;
 		perf_evlist__delete;
 		perf_evlist__open;