From e546db5e9c81fabace719417cc77154e08355005 Mon Sep 17 00:00:00 2001
Date: Fri, 22 Jan 2021 11:37:38 +0800
Subject: Backport of JDK-8131600

Summary: JVM crashes when doing heapdump and handling a signal at a same time
LLT: none

Bug url: https://bugs.openjdk.java.net/browse/JDK-8131600
---
 hotspot/src/share/vm/prims/jvmtiTagMap.cpp   | 2 +-
 hotspot/src/share/vm/services/heapDumper.cpp | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/hotspot/src/share/vm/prims/jvmtiTagMap.cpp b/hotspot/src/share/vm/prims/jvmtiTagMap.cpp
index 224cd21ad..dc600d8ea 100644
--- a/hotspot/src/share/vm/prims/jvmtiTagMap.cpp
+++ b/hotspot/src/share/vm/prims/jvmtiTagMap.cpp
@@ -2829,7 +2829,7 @@ inline bool VM_HeapWalkOperation::iterate_over_class(oop java_class) {
   if (klass->oop_is_instance()) {
     InstanceKlass* ik = InstanceKlass::cast(klass);
 
-    // ignore the class if it's has been initialized yet
+    // Ignore the class if it hasn't been initialized yet
     if (!ik->is_linked()) {
       return true;
     }
diff --git a/hotspot/src/share/vm/services/heapDumper.cpp b/hotspot/src/share/vm/services/heapDumper.cpp
index e9fd8946a..24c0830c5 100644
--- a/hotspot/src/share/vm/services/heapDumper.cpp
+++ b/hotspot/src/share/vm/services/heapDumper.cpp
@@ -990,6 +990,11 @@ void DumperSupport::dump_class_and_array_classes(DumpWriter* writer, Klass* k) {
     return;
   }
 
+  // Ignore the class if it hasn't been initialized yet
+  if (!ik->is_linked()) {
+    return;
+  }
+
   writer->write_u1(HPROF_GC_CLASS_DUMP);
 
   // class ID
-- 
2.19.0