8369505: jhsdb jstack cannot handle continuation stub

src/hotspot/share/runtime/continuationEntry.hpp

@@ -39,6 +39,7 @@ class RegisterMap;
 
 // Metadata stored in the continuation entry frame
 class ContinuationEntry {
+  friend class VMStructs;
   friend class JVMCIVMStructs;
   ContinuationEntryPD _pd;
 #ifdef ASSERT

src/hotspot/share/runtime/vmStructs.cpp

@@ -616,6 +616,7 @@
   nonstatic_field(JavaThread,                  _active_handles,                               JNIHandleBlock*)                       \
   nonstatic_field(JavaThread,                  _monitor_owner_id,                             int64_t)                               \
   volatile_nonstatic_field(JavaThread,         _terminated,                                   JavaThread::TerminatedTypes)           \
+  nonstatic_field(JavaThread,                  _cont_entry,                                   ContinuationEntry*)                    \
   nonstatic_field(Thread,                      _osthread,                                     OSThread*)                             \
                                                                                                                                      \
   /************/                                                                                                                     \
@@ -796,7 +797,8 @@
   nonstatic_field(Mutex,                       _name,                                         const char*)                           \
   static_field(Mutex,                          _mutex_array,                                  Mutex**)                               \
   static_field(Mutex,                          _num_mutex,                                    int)                                   \
-  volatile_nonstatic_field(Mutex,              _owner,                                        Thread*)
+  volatile_nonstatic_field(Mutex,              _owner,                                        Thread*)                               \
+  static_field(ContinuationEntry,              _return_pc,                                    address)
 
 //--------------------------------------------------------------------------------
 // VM_TYPES
@@ -1270,6 +1272,7 @@
   declare_toplevel_type(FileMapHeader)                                    \
   declare_toplevel_type(CDSFileMapRegion)                                 \
   declare_toplevel_type(UpcallStub::FrameData)                            \
+  declare_toplevel_type(ContinuationEntry)                                \
                                                                           \
   /************/                                                          \
   /* GC types */                                                          \

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/code/CodeBlob.java

@@ -180,6 +180,8 @@ public ImmutableOopMapSet getOopMaps() {
 
   public boolean isUpcallStub()         { return getKind() == UpcallKind; }
 
+  public boolean isContinuationStub()   { return getName().equals("StubRoutines (continuation stubs)"); }
+
   public boolean isJavaMethod()         { return false; }
 
   public boolean isNativeMethod()       { return false; }

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/ContinuationEntry.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2025, NTT DATA.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+package sun.jvm.hotspot.runtime;
+
+import sun.jvm.hotspot.debugger.*;
+import sun.jvm.hotspot.runtime.*;
+import sun.jvm.hotspot.types.*;
+
+
+public class ContinuationEntry extends VMObject {
+    private static long size;
+    private static Address returnPC;
+
+    static {
+        VM.registerVMInitializedObserver((o, d) -> initialize(VM.getVM().getTypeDataBase()));
+    }
+
+    private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {
+        Type type = db.lookupType("ContinuationEntry");
+        size = type.getSize();
+        returnPC = type.getAddressField("_return_pc").getValue();
+    }
+
+    public ContinuationEntry(Address addr) {
+        super(addr);
+    }
+
+    public Address getEntryPC() {
+        return returnPC;
+    }
+
+    public Address getEntrySP(){
+        return this.getAddress();
+    }
+
+    public Address getEntryFP(){
+        return this.getAddress().addOffsetTo(size);
+    }
+
+}

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/JavaThread.java

@@ -47,6 +47,7 @@ public class JavaThread extends Thread {
   private static AddressField  stackBaseField;
   private static CIntegerField stackSizeField;
   private static CIntegerField terminatedField;
+  private static AddressField  contEntryField;
   private static AddressField activeHandlesField;
   private static CIntegerField monitorOwnerIDField;
   private static long oopPtrSize;
@@ -95,6 +96,7 @@ private static synchronized void initialize(TypeDataBase db) {
     stackBaseField    = type.getAddressField("_stack_base");
     stackSizeField    = type.getCIntegerField("_stack_size");
     terminatedField   = type.getCIntegerField("_terminated");
+    contEntryField    = type.getAddressField("_cont_entry");
     activeHandlesField = type.getAddressField("_active_handles");
     monitorOwnerIDField = type.getCIntegerField("_monitor_owner_id");
 
@@ -340,6 +342,10 @@ public int getTerminated() {
       return (int) terminatedField.getValue(addr);
   }
 
+  public ContinuationEntry getContEntry() {
+      return VMObjectFactory.newObject(ContinuationEntry.class, contEntryField.getValue(addr));
+  }
+
   /** Gets the Java-side thread object for this JavaThread */
   public Oop getThreadObj() {
     Oop obj = null;

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/aarch64/AARCH64Frame.java

@@ -270,7 +270,13 @@ public Frame sender(RegisterMap regMap, CodeBlob cb) {
     }
 
     if (cb != null) {
-      return cb.isUpcallStub() ? senderForUpcallStub(map, (UpcallStub)cb) : senderForCompiledFrame(map, cb);
+      if (cb.isUpcallStub()) {
+        return senderForUpcallStub(map, (UpcallStub)cb);
+      } else if (cb.isContinuationStub()) {
+        return senderForContinuationStub(map, cb);
+      } else {
+        return senderForCompiledFrame(map, cb);
+      }
     }
 
     // Must be native-compiled frame, i.e. the marshaling code for native
@@ -356,6 +362,16 @@ private void updateMapWithSavedLink(RegisterMap map, Address savedFPAddr) {
     map.setLocation(fp, savedFPAddr);
   }
 
+  private Frame senderForContinuationStub(AARCH64RegisterMap map, CodeBlob cb) {
+    var contEntry = map.getThread().getContEntry();
+
+    Address senderSP = contEntry.getEntrySP();
+    Address senderPC = contEntry.getEntryPC();
+    Address senderFP = contEntry.getEntryFP();
+
+    return new AARCH64Frame(senderSP, senderFP, senderPC);
+  }
+
   private Frame senderForCompiledFrame(AARCH64RegisterMap map, CodeBlob cb) {
     if (DEBUG) {
       System.out.println("senderForCompiledFrame");

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/riscv64/RISCV64Frame.java

@@ -262,7 +262,13 @@ public Frame sender(RegisterMap regMap, CodeBlob cb) {
     }
 
     if (cb != null) {
-      return cb.isUpcallStub() ? senderForUpcallStub(map, (UpcallStub)cb) : senderForCompiledFrame(map, cb);
+      if (cb.isUpcallStub()) {
+        return senderForUpcallStub(map, (UpcallStub)cb);
+      } else if (cb.isContinuationStub()) {
+        return senderForContinuationStub(map, cb);
+      } else {
+        return senderForCompiledFrame(map, cb);
+      }
     }
 
     // Must be native-compiled frame, i.e. the marshaling code for native
@@ -348,6 +354,16 @@ private void updateMapWithSavedLink(RegisterMap map, Address savedFPAddr) {
     map.setLocation(fp, savedFPAddr);
   }
 
+  private Frame senderForContinuationStub(RISCV64RegisterMap map, CodeBlob cb) {
+    var contEntry = map.getThread().getContEntry();
+
+    Address senderSP = contEntry.getEntrySP();
+    Address senderPC = contEntry.getEntryPC();
+    Address senderFP = contEntry.getEntryFP();
+
+    return new RISCV64Frame(senderSP, senderFP, senderPC);
+  }
+
   private Frame senderForCompiledFrame(RISCV64RegisterMap map, CodeBlob cb) {
     if (DEBUG) {
       System.out.println("senderForCompiledFrame");

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/x86/X86Frame.java

@@ -270,7 +270,13 @@ public Frame sender(RegisterMap regMap, CodeBlob cb) {
     }
 
     if (cb != null) {
-      return cb.isUpcallStub() ? senderForUpcallStub(map, (UpcallStub)cb) : senderForCompiledFrame(map, cb);
+      if (cb.isUpcallStub()) {
+        return senderForUpcallStub(map, (UpcallStub)cb);
+      } else if (cb.isContinuationStub()) {
+        return senderForContinuationStub(map, cb);
+      } else {
+        return senderForCompiledFrame(map, cb);
+      }
     }
 
     // Must be native-compiled frame, i.e. the marshaling code for native
@@ -356,6 +362,16 @@ private void updateMapWithSavedLink(RegisterMap map, Address savedFPAddr) {
     map.setLocation(rbp, savedFPAddr);
   }
 
+  private Frame senderForContinuationStub(X86RegisterMap map, CodeBlob cb) {
+    var contEntry = map.getThread().getContEntry();
+
+    Address senderSP = contEntry.getEntrySP();
+    Address senderPC = contEntry.getEntryPC();
+    Address senderFP = contEntry.getEntryFP();
+
+    return new X86Frame(senderSP, senderFP, senderPC);
+  }
+
   private Frame senderForCompiledFrame(X86RegisterMap map, CodeBlob cb) {
     if (DEBUG) {
       System.out.println("senderForCompiledFrame");

test/hotspot/jtreg/serviceability/sa/LingeredAppWithVirtualThread.java

@@ -0,0 +1,87 @@
+
+/*
+ * Copyright (c) 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2025, NTT DATA
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import java.lang.invoke.MethodHandle;
+import java.lang.foreign.Arena;
+import java.lang.foreign.FunctionDescriptor;
+import java.lang.foreign.Linker;
+import java.lang.foreign.MemorySegment;
+import java.lang.foreign.SymbolLookup;
+import java.lang.foreign.ValueLayout;
+import java.util.concurrent.CountDownLatch;
+
+import jdk.test.lib.apps.LingeredApp;
+
+public class LingeredAppWithVirtualThread extends LingeredApp implements Runnable {
+
+    private static final String THREAD_NAME = "target thread";
+
+    private static final MethodHandle hndSleep;
+
+    private static final int sleepArg;
+
+    private static final CountDownLatch signal = new CountDownLatch(1);
+
+    static {
+        MemorySegment func;
+        if (System.getProperty("os.name").startsWith("Windows")) {
+            func = SymbolLookup.libraryLookup("Kernel32", Arena.global())
+                               .findOrThrow("Sleep");
+            sleepArg = 3600_000; // 1h in milliseconds
+        } else {
+            func = Linker.nativeLinker()
+                         .defaultLookup()
+                         .findOrThrow("sleep");
+            sleepArg = 3600; // 1h in seconds
+        }
+
+        var desc = FunctionDescriptor.of(ValueLayout.JAVA_INT, ValueLayout.JAVA_INT);
+        hndSleep = Linker.nativeLinker().downcallHandle(func, desc);
+    }
+
+    @Override
+    public void run() {
+        Thread.yield();
+        signal.countDown();
+        try {
+            hndSleep.invoke(sleepArg);
+        } catch (Throwable t) {
+            throw new RuntimeException(t);
+        }
+    }
+
+    public static void main(String[] args) {
+        try {
+            Thread.ofVirtual()
+                  .name(THREAD_NAME)
+                  .start(new LingeredAppWithVirtualThread());
+
+            signal.await();
+            LingeredApp.main(args);
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+}