From 55c509708e9b89a7609fd41b6e5a271f250bbacd Mon Sep 17 00:00:00 2001
From: Jiawei Tang <jwtang@openjdk.org>
Date: Fri, 9 Aug 2024 02:29:15 +0000
Subject: [PATCH] 8337331: crash: pinned virtual thread will lead to jvm crash
 when running with the javaagent option

Reviewed-by: dholmes, sspitsyn
---
 src/hotspot/share/prims/jvmtiExport.cpp       | 10 +--
 .../TestPinCaseWithCFLH.java                  | 77 +++++++++++++++++++
 2 files changed, 82 insertions(+), 5 deletions(-)
 create mode 100644 test/hotspot/jtreg/serviceability/jvmti/vthread/TestPinCaseWithCFLH/TestPinCaseWithCFLH.java

diff --git a/src/hotspot/share/prims/jvmtiExport.cpp b/src/hotspot/share/prims/jvmtiExport.cpp
index f79116f5ebe..95cc54d9313 100644
--- a/src/hotspot/share/prims/jvmtiExport.cpp
+++ b/src/hotspot/share/prims/jvmtiExport.cpp
@@ -929,9 +929,8 @@ class JvmtiClassFileLoadHookPoster : public StackObj {
     _cached_class_file_ptr = cache_ptr;
     _has_been_modified = false;
 
-    if (_thread->is_in_any_VTMS_transition()) {
-      return; // no events should be posted if thread is in any VTMS transition
-    }
+    assert(!_thread->is_in_any_VTMS_transition(), "CFLH events are not allowed in any VTMS transition");
+
     _state = JvmtiExport::get_jvmti_thread_state(_thread);
     if (_state != nullptr) {
       _class_being_redefined = _state->get_class_being_redefined();
@@ -1091,8 +1090,9 @@ bool JvmtiExport::post_class_file_load_hook(Symbol* h_name,
   if (JvmtiEnv::get_phase() < JVMTI_PHASE_PRIMORDIAL) {
     return false;
   }
-  if (JavaThread::current()->is_in_tmp_VTMS_transition()) {
-    return false; // skip CFLH events in tmp VTMS transition
+
+  if (JavaThread::current()->is_in_any_VTMS_transition()) {
+    return false; // no events should be posted if thread is in any VTMS transition
   }
 
   JvmtiClassFileLoadHookPoster poster(h_name, class_loader,
diff --git a/test/hotspot/jtreg/serviceability/jvmti/vthread/TestPinCaseWithCFLH/TestPinCaseWithCFLH.java b/test/hotspot/jtreg/serviceability/jvmti/vthread/TestPinCaseWithCFLH/TestPinCaseWithCFLH.java
new file mode 100644
index 00000000000..02755a0289f
--- /dev/null
+++ b/test/hotspot/jtreg/serviceability/jvmti/vthread/TestPinCaseWithCFLH/TestPinCaseWithCFLH.java
@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2024, Oracle and/or its affiliates. All rights reserved.
+ * 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.instrument.ClassFileTransformer;
+import java.lang.instrument.IllegalClassFormatException;
+import java.lang.instrument.Instrumentation;
+import java.security.ProtectionDomain;
+import jdk.test.lib.thread.VThreadPinner;
+
+/*
+ * @test
+ * @summary javaagent + tracePinnedThreads will cause jvm crash/ run into deadlock when the virtual thread is pinned
+ * @library /test/lib
+ * @requires vm.continuations
+ * @requires vm.jvmti
+ * @modules java.base/java.lang:+open
+ * @compile TestPinCaseWithCFLH.java
+ * @build jdk.test.lib.Utils
+ * @run driver jdk.test.lib.util.JavaAgentBuilder
+ *             TestPinCaseWithCFLH TestPinCaseWithCFLH.jar
+ * @run main/othervm/timeout=100  -Djdk.virtualThreadScheduler.maxPoolSize=1
+ *       -Djdk.tracePinnedThreads=full --enable-native-access=ALL-UNNAMED
+ *       -javaagent:TestPinCaseWithCFLH.jar TestPinCaseWithCFLH
+ */
+public class TestPinCaseWithCFLH {
+
+    public static class TestClassFileTransformer implements ClassFileTransformer {
+        public byte[] transform(ClassLoader loader, String className, Class<?> classBeingRedefined,
+                                ProtectionDomain protectionDomain, byte[] classfileBuffer)
+                                throws IllegalClassFormatException {
+            return classfileBuffer;
+        }
+    }
+
+    // Called when agent is loaded at startup
+    public static void premain(String agentArgs, Instrumentation instrumentation) throws Exception {
+        instrumentation.addTransformer(new TestClassFileTransformer());
+    }
+
+    private static int result = 0;
+
+    public static void main(String[] args) throws Exception{
+        Thread t1 = Thread.ofVirtual().name("vthread-1").start(() -> {
+            VThreadPinner.runPinned(() -> {
+                try {
+                    // try yield, will pin,
+                    // javaagent + tracePinnedThreads should not lead to crash
+                    // (because of the class `PinnedThreadPrinter`)
+                    Thread.sleep(500);
+                } catch (Exception e) {
+                    e.printStackTrace();
+                }
+            });
+        });
+        t1.join();
+    }
+
+}
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