fix style and bug

Author: JohnTortugo

src/hotspot/share/jvmci/jvmciCompilerToVM.cpp

@@ -27,8 +27,8 @@
 #include "classfile/symbolTable.hpp"
 #include "classfile/systemDictionary.hpp"
 #include "classfile/vmClasses.hpp"
-#include "code/scopeDesc.hpp"
 #include "code/nmethod.hpp"
+#include "code/scopeDesc.hpp"
 #include "compiler/compileBroker.hpp"
 #include "compiler/compilerEvent.hpp"
 #include "compiler/compilerOracle.hpp"
@@ -2254,6 +2254,16 @@ static jobject read_field_value(Handle obj, long displacement, jchar type_char,
   if (!aligned) {
     JVMCI_THROW_MSG_NULL(IllegalArgumentException, "read is unaligned");
   }
+  if (obj->is_array()) {
+    // Disallow reading after the last element of an array
+    size_t array_length = arrayOop(obj())->length();
+    int lh = obj->klass()->layout_helper();
+    size_t size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
+    size_in_bytes += Klass::layout_helper_header_size(lh);
+    if ((size_t) displacement + basic_type_elemsize > size_in_bytes) {
+      JVMCI_THROW_MSG_NULL(IllegalArgumentException, "reading after last array element");
+    }
+  }
   if (basic_type == T_OBJECT) {
     if (obj->is_objArray()) {
       if (displacement < arrayOopDesc::base_offset_in_bytes(T_OBJECT)) {