1 files changed, 10 insertions, 2 deletions
diff --git a/core/vm/stack_table.go b/core/vm/stack_table.go
index 0936ef06f..eed8805f2 100644
--- a/core/vm/stack_table.go
+++ b/core/vm/stack_table.go
@@ -6,15 +6,23 @@ import (
 	"github.com/ethereum/go-ethereum/params"
 )
 
-func makeStackFunc(pop, push int) stackValidationFunc {
+func makeStackFunc(pop, diff int) stackValidationFunc {
 	return func(stack *Stack) error {
 		if err := stack.require(pop); err != nil {
 			return err
 		}
 
-		if push > 0 && stack.len()-pop+push > int(params.StackLimit) {
+		if int64(stack.len()+diff) > params.StackLimit.Int64() {
 			return fmt.Errorf("stack limit reached %d (%d)", stack.len(), params.StackLimit)
 		}
 		return nil
 	}
 }
+
+func makeDupStackFunc(n int) stackValidationFunc {
+	return makeStackFunc(n, 1)
+}
+
+func makeSwapStackFunc(n int) stackValidationFunc {
+	return makeStackFunc(n, 0)
+}