diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index f072ed31..7a54ab50 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -21,18 +21,20 @@
 #include <linux/stacktrace.h>
 #include <linux/rculist.h>
 
 #include "tracing_map.h"
 #include "trace.h"
 
 struct hist_field;
 
-typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event,
-				struct ring_buffer_event *rbe);
+typedef u64 (*hist_field_fn_t) (struct hist_field *field,
+				struct tracing_map_elt *elt,
+				struct ring_buffer_event *rbe,
+				void *event);
 
 #define HIST_FIELD_OPERANDS_MAX	2
 #define HIST_FIELDS_MAX		(TRACING_MAP_FIELDS_MAX + TRACING_MAP_VARS_MAX)
 
 enum field_op_id {
 	FIELD_OP_NONE,
 	FIELD_OP_PLUS,
 	FIELD_OP_MINUS,
@@ -54,103 +56,122 @@ struct hist_field {
 	unsigned int                    is_signed;
 	struct hist_field		*operands[HIST_FIELD_OPERANDS_MAX];
 	struct hist_trigger_data	*hist_data;
 	struct hist_var			var;
 	enum field_op_id		operator;
 	char				*name;
 };
 
-static u64 hist_field_none(struct hist_field *field, void *event,
-			   struct ring_buffer_event *rbe)
+static u64 hist_field_none(struct hist_field *field,
+			   struct tracing_map_elt *elt,
+			   struct ring_buffer_event *rbe,
+			   void *event)
 {
 	return 0;
 }
 
-static u64 hist_field_counter(struct hist_field *field, void *event,
-			      struct ring_buffer_event *rbe)
+static u64 hist_field_counter(struct hist_field *field,
+			      struct tracing_map_elt *elt,
+			      struct ring_buffer_event *rbe,
+			      void *event)
 {
 	return 1;
 }
 
-static u64 hist_field_string(struct hist_field *hist_field, void *event,
-			     struct ring_buffer_event *rbe)
+static u64 hist_field_string(struct hist_field *hist_field,
+			     struct tracing_map_elt *elt,
+			     struct ring_buffer_event *rbe,
+			     void *event)
 {
 	char *addr = (char *)(event + hist_field->field->offset);
 
 	return (u64)(unsigned long)addr;
 }
 
-static u64 hist_field_dynstring(struct hist_field *hist_field, void *event,
-				struct ring_buffer_event *rbe)
+static u64 hist_field_dynstring(struct hist_field *hist_field,
+				struct tracing_map_elt *elt,
+				struct ring_buffer_event *rbe,
+				void *event)
 {
 	u32 str_item = *(u32 *)(event + hist_field->field->offset);
 	int str_loc = str_item & 0xffff;
 	char *addr = (char *)(event + str_loc);
 
 	return (u64)(unsigned long)addr;
 }
 
-static u64 hist_field_pstring(struct hist_field *hist_field, void *event,
-			      struct ring_buffer_event *rbe)
+static u64 hist_field_pstring(struct hist_field *hist_field,
+			      struct tracing_map_elt *elt,
+			      struct ring_buffer_event *rbe,
+			      void *event)
 {
 	char **addr = (char **)(event + hist_field->field->offset);
 
 	return (u64)(unsigned long)*addr;
 }
 
-static u64 hist_field_log2(struct hist_field *hist_field, void *event,
-			   struct ring_buffer_event *rbe)
+static u64 hist_field_log2(struct hist_field *hist_field,
+			   struct tracing_map_elt *elt,
+			   struct ring_buffer_event *rbe,
+			   void *event)
 {
 	struct hist_field *operand = hist_field->operands[0];
 
-	u64 val = operand->fn(operand, event, rbe);
+	u64 val = operand->fn(operand, elt, rbe, event);
 
 	return (u64) ilog2(roundup_pow_of_two(val));
 }
 
-static u64 hist_field_plus(struct hist_field *hist_field, void *event,
-			   struct ring_buffer_event *rbe)
+static u64 hist_field_plus(struct hist_field *hist_field,
+			   struct tracing_map_elt *elt,
+			   struct ring_buffer_event *rbe,
+			   void *event)
 {
 	struct hist_field *operand1 = hist_field->operands[0];
 	struct hist_field *operand2 = hist_field->operands[1];
 
-	u64 val1 = operand1->fn(operand1, event, rbe);
-	u64 val2 = operand2->fn(operand2, event, rbe);
+	u64 val1 = operand1->fn(operand1, elt, rbe, event);
+	u64 val2 = operand2->fn(operand2, elt, rbe, event);
 
 	return val1 + val2;
 }
 
-static u64 hist_field_minus(struct hist_field *hist_field, void *event,
-			    struct ring_buffer_event *rbe)
+static u64 hist_field_minus(struct hist_field *hist_field,
+			    struct tracing_map_elt *elt,
+			    struct ring_buffer_event *rbe,
+			    void *event)
 {
 	struct hist_field *operand1 = hist_field->operands[0];
 	struct hist_field *operand2 = hist_field->operands[1];
 
-	u64 val1 = operand1->fn(operand1, event, rbe);
-	u64 val2 = operand2->fn(operand2, event, rbe);
+	u64 val1 = operand1->fn(operand1, elt, rbe, event);
+	u64 val2 = operand2->fn(operand2, elt, rbe, event);
 
 	return val1 - val2;
 }
 
-static u64 hist_field_unary_minus(struct hist_field *hist_field, void *event,
-				  struct ring_buffer_event *rbe)
+static u64 hist_field_unary_minus(struct hist_field *hist_field,
+				  struct tracing_map_elt *elt,
+				  struct ring_buffer_event *rbe,
+				  void *event)
 {
 	struct hist_field *operand = hist_field->operands[0];
 
-	s64 sval = (s64)operand->fn(operand, event, rbe);
+	s64 sval = (s64)operand->fn(operand, elt, rbe, event);
 	u64 val = (u64)-sval;
 
 	return val;
 }
 
 #define DEFINE_HIST_FIELD_FN(type)					\
 	static u64 hist_field_##type(struct hist_field *hist_field,	\
-				     void *event,			\
-				     struct ring_buffer_event *rbe)	\
+				     struct tracing_map_elt *elt,	\
+				     struct ring_buffer_event *rbe,	\
+				     void *event)			\
 {									\
 	type *addr = (type *)(event + hist_field->field->offset);	\
 									\
 	return (u64)(unsigned long)*addr;				\
 }
 
 DEFINE_HIST_FIELD_FN(s64);
 DEFINE_HIST_FIELD_FN(u64);
@@ -228,18 +249,20 @@ struct hist_trigger_data {
 	unsigned int			n_sort_keys;
 	struct trace_event_file		*event_file;
 	struct hist_trigger_attrs	*attrs;
 	struct tracing_map		*map;
 	bool				enable_timestamps;
 	bool				remove;
 };
 
-static u64 hist_field_timestamp(struct hist_field *hist_field, void *event,
-				struct ring_buffer_event *rbe)
+static u64 hist_field_timestamp(struct hist_field *hist_field,
+				struct tracing_map_elt *elt,
+				struct ring_buffer_event *rbe,
+				void *event)
 {
 	struct hist_trigger_data *hist_data = hist_field->hist_data;
 	struct trace_array *tr = hist_data->event_file->tr;
 
 	u64 ts = ring_buffer_event_time_stamp(rbe);
 
 	if (hist_data->attrs->ts_in_usecs && trace_clock_in_ns(tr))
 		ts = ns2usecs(ts);
@@ -1565,29 +1588,29 @@ static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,
 				    struct ring_buffer_event *rbe)
 {
 	struct hist_field *hist_field;
 	unsigned int i, var_idx;
 	u64 hist_val;
 
 	for_each_hist_val_field(i, hist_data) {
 		hist_field = hist_data->fields[i];
-		hist_val = hist_field->fn(hist_field, rec, rbe);
+		hist_val = hist_field->fn(hist_field, elt, rbe, rec);
 		if (hist_field->flags & HIST_FIELD_FL_VAR) {
 			var_idx = hist_field->var.idx;
 			tracing_map_set_var(elt, var_idx, hist_val);
 			continue;
 		}
 		tracing_map_update_sum(elt, i, hist_val);
 	}
 
 	for_each_hist_key_field(i, hist_data) {
 		hist_field = hist_data->fields[i];
 		if (hist_field->flags & HIST_FIELD_FL_VAR) {
-			hist_val = hist_field->fn(hist_field, rec, rbe);
+			hist_val = hist_field->fn(hist_field, elt, rbe, rec);
 			var_idx = hist_field->var.idx;
 			tracing_map_set_var(elt, var_idx, hist_val);
 		}
 	}
 }
 
 static inline void add_to_key(char *compound_key, void *key,
 			      struct hist_field *key_field, void *rec)
@@ -1615,19 +1638,19 @@ static inline void add_to_key(char *compound_key, void *key,
 
 static void event_hist_trigger(struct event_trigger_data *data, void *rec,
 			       struct ring_buffer_event *rbe)
 {
 	struct hist_trigger_data *hist_data = data->private_data;
 	bool use_compound_key = (hist_data->n_keys > 1);
 	unsigned long entries[HIST_STACKTRACE_DEPTH];
 	char compound_key[HIST_KEY_SIZE_MAX];
+	struct tracing_map_elt *elt = NULL;
 	struct stack_trace stacktrace;
 	struct hist_field *key_field;
-	struct tracing_map_elt *elt;
 	u64 field_contents;
 	void *key = NULL;
 	unsigned int i;
 
 	memset(compound_key, 0, hist_data->key_size);
 
 	for_each_hist_key_field(i, hist_data) {
 		key_field = hist_data->fields[i];
@@ -1638,17 +1661,17 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec,
 			stacktrace.nr_entries = 0;
 			stacktrace.skip = HIST_STACKTRACE_SKIP;
 
 			memset(stacktrace.entries, 0, HIST_STACKTRACE_SIZE);
 			save_stack_trace(&stacktrace);
 
 			key = entries;
 		} else {
-			field_contents = key_field->fn(key_field, rec, rbe);
+			field_contents = key_field->fn(key_field, elt, rbe, rec);
 			if (key_field->flags & HIST_FIELD_FL_STRING) {
 				key = (void *)(unsigned long)field_contents;
 				use_compound_key = true;
 			} else
 				key = (void *)&field_contents;
 		}
 
 		if (use_compound_key)
