8025238: nsk/jvmti/scenarios/bcinstr/BI04/bi04t002 crashed with SIGSEGV

Redefined class in stack trace may not be found by method_idnum so handle null.

Reviewed-by: sla, dcubed, sspitsyn

hotspot/src/share/vm/classfile/javaClasses.cpp

@@ -1376,8 +1376,15 @@ char* java_lang_Throwable::print_stack_element_to_buffer(Handle mirror,
   const char* klass_name  = holder->external_name();
   int buf_len = (int)strlen(klass_name);
 
-  // pushing to the stack trace added one.
+  // The method id may point to an obsolete method, can't get more stack information
   Method* method = holder->method_with_idnum(method_id);
+  if (method == NULL) {
+    char* buf = NEW_RESOURCE_ARRAY(char, buf_len + 64);
+    // This is what the java code prints in this case - added Redefined
+    sprintf(buf, "\tat %s.null (Redefined)", klass_name);
+    return buf;
+  }
+
   char* method_name = method->name()->as_C_string();
   buf_len += (int)strlen(method_name);
 
@@ -1773,7 +1780,8 @@ oop java_lang_Throwable::get_stack_trace_element(oop throwable, int index, TRAPS
   return element;
 }
 
-oop java_lang_StackTraceElement::create(Handle mirror, int method_id, int version, int bci, TRAPS) {
+oop java_lang_StackTraceElement::create(Handle mirror, int method_id,
+                                        int version, int bci, TRAPS) {
   // Allocate java.lang.StackTraceElement instance
   Klass* k = SystemDictionary::StackTraceElement_klass();
   assert(k != NULL, "must be loaded in 1.4+");
@@ -1790,8 +1798,16 @@ oop java_lang_StackTraceElement::create(Handle mirror, int method_id, int versio
   oop classname = StringTable::intern((char*) str, CHECK_0);
   java_lang_StackTraceElement::set_declaringClass(element(), classname);
 
-  // Fill in method name
   Method* method = holder->method_with_idnum(method_id);
+  // Method on stack may be obsolete because it was redefined so cannot be
+  // found by idnum.
+  if (method == NULL) {
+    // leave name and fileName null
+    java_lang_StackTraceElement::set_lineNumber(element(), -1);
+    return element();
+  }
+
+  // Fill in method name
   oop methodname = StringTable::intern(method->name(), CHECK_0);
   java_lang_StackTraceElement::set_methodName(element(), methodname);
 

hotspot/src/share/vm/prims/jvmtiRedefineClasses.cpp

@@ -2931,7 +2931,8 @@ void VM_RedefineClasses::check_methods_and_mark_as_obsolete(
       old_method->set_is_obsolete();
       obsolete_count++;
 
-      // obsolete methods need a unique idnum
+      // obsolete methods need a unique idnum so they become new entries in
+      // the jmethodID cache in InstanceKlass
       u2 num = InstanceKlass::cast(_the_class_oop)->next_method_idnum();
       if (num != ConstMethod::UNSET_IDNUM) {
         old_method->set_method_idnum(num);