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-rw-r--r--kernel/trace/trace_events_hist.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index d33b046f985a..6ac35b9e195d 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -116,6 +116,7 @@ struct hist_field {
struct ftrace_event_field *field;
unsigned long flags;
hist_field_fn_t fn;
+ unsigned int ref;
unsigned int size;
unsigned int offset;
unsigned int is_signed;
@@ -2427,8 +2428,16 @@ static int contains_operator(char *str)
return field_op;
}
+static void get_hist_field(struct hist_field *hist_field)
+{
+ hist_field->ref++;
+}
+
static void __destroy_hist_field(struct hist_field *hist_field)
{
+ if (--hist_field->ref > 1)
+ return;
+
kfree(hist_field->var.name);
kfree(hist_field->name);
kfree(hist_field->type);
@@ -2470,6 +2479,8 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
if (!hist_field)
return NULL;
+ hist_field->ref = 1;
+
hist_field->hist_data = hist_data;
if (flags & HIST_FIELD_FL_EXPR || flags & HIST_FIELD_FL_ALIAS)
@@ -2665,6 +2676,17 @@ static struct hist_field *create_var_ref(struct hist_trigger_data *hist_data,
{
unsigned long flags = HIST_FIELD_FL_VAR_REF;
struct hist_field *ref_field;
+ int i;
+
+ /* Check if the variable already exists */
+ for (i = 0; i < hist_data->n_var_refs; i++) {
+ ref_field = hist_data->var_refs[i];
+ if (ref_field->var.idx == var_field->var.idx &&
+ ref_field->var.hist_data == var_field->hist_data) {
+ get_hist_field(ref_field);
+ return ref_field;
+ }
+ }
ref_field = create_hist_field(var_field->hist_data, NULL, flags, NULL);
if (ref_field) {