2 files changed, 13 insertions, 6 deletions

diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index 634b7f7140d5..9e8995eaf2b6 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -36,7 +36,10 @@ int thread__set_comm(struct thread *self, const char *comm)
         if (self->comm)
                 free(self->comm);
         self->comm = strdup(comm);
-        return self->comm ? 0 : -ENOMEM;
+        if (self->comm == NULL)
+                return -ENOMEM;
+        self->comm_set = true;
+        return 0;
 }
 
 int thread__comm_len(struct thread *self)
@@ -255,11 +258,14 @@ int thread__fork(struct thread *self, struct thread *parent)
 {
         int i;
 
-        if (self->comm)
-                free(self->comm);
-        self->comm = strdup(parent->comm);
-        if (!self->comm)
-                return -ENOMEM;
+        if (parent->comm_set) {
+                if (self->comm)
+                        free(self->comm);
+                self->comm = strdup(parent->comm);
+                if (!self->comm)
+                        return -ENOMEM;
+                self->comm_set = true;
+        }
 
         for (i = 0; i < MAP__NR_TYPES; ++i)
                 if (map_groups__clone(&self->mg, &parent->mg, i) < 0)
diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h
index 56f317b8a06c..0a28f39de545 100644
--- a/tools/perf/util/thread.h
+++ b/tools/perf/util/thread.h
@@ -15,6 +15,7 @@ struct thread {
         struct map_groups       mg;
         pid_t                   pid;
         char                    shortname[3];
+        bool                    comm_set;
         char                    *comm;
         int                     comm_len;
 };