perf probe: Set default kprobe group name if it is not given

Set kprobe group name as "probe" if it is not given.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160426090413.11891.95640.stgit@devboxSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/probe-event.c

@@ -2748,8 +2748,12 @@ static int convert_to_probe_trace_events(struct perf_probe_event *pev,
 {
 	int ret;
 
-	if (pev->uprobes && !pev->group) {
-		/* Replace group name if not given */
+	if (!pev->group) {
+		/* Set group name if not given */
+		if (!pev->uprobes) {
+			pev->group = strdup(PERFPROBE_GROUP);
+			ret = pev->group ? 0 : -ENOMEM;
+		} else
 			ret = convert_exec_to_group(pev->target, &pev->group);
 		if (ret != 0) {
 			pr_warning("Failed to make a group name.\n");