perf dso: Sort symbols under lock

Determine if symbols are sorted, set the sorted flag and sort under
the dso lock. Done in the interest of thread safety.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Carsten Haitzler <carsten.haitzler@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Jason Wang <wangborong@cdjrlc.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/20230623054520.4118442-2-irogers@google.com
[ handle the similar code in util/probe-event.c ]
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

tools/perf/util/map.c

@@ -398,8 +398,7 @@ struct symbol *map__find_symbol_by_name(struct map *map, const char *name)
 		return NULL;
 
 	dso = map__dso(map);
-	if (!dso__sorted_by_name(dso))
-		dso__sort_by_name(dso);
+	dso__sort_by_name(dso);
 
 	return dso__find_symbol_by_name(dso, name);
 }

tools/perf/util/probe-event.c

@@ -3767,8 +3767,7 @@ int show_available_funcs(const char *target, struct nsinfo *nsi,
 		goto end;
 	}
 	dso = map__dso(map);
-	if (!dso__sorted_by_name(dso))
-		dso__sort_by_name(dso);
+	dso__sort_by_name(dso);
 
 	/* Show all (filtered) symbols */
 	setup_pager();

tools/perf/util/symbol.c

@@ -613,8 +613,12 @@ struct symbol *dso__find_symbol_by_name(struct dso *dso, const char *name)
 
 void dso__sort_by_name(struct dso *dso)
 {
-	dso__set_sorted_by_name(dso);
-	return symbols__sort_by_name(&dso->symbol_names, &dso->symbols);
+	mutex_lock(&dso->lock);
+	if (!dso__sorted_by_name(dso)) {
+		symbols__sort_by_name(&dso->symbol_names, &dso->symbols);
+		dso__set_sorted_by_name(dso);
+	}
+	mutex_unlock(&dso->lock);
 }
 
 /*