From 194be8180f89cd247d31e5ecdb23cb5261db2625 Mon Sep 17 00:00:00 2001
From: Guanqiang Han <ghan@openjdk.org>
Date: Wed, 25 Feb 2026 13:13:51 +0000
Subject: [PATCH] 8374807: Crash in MethodData::extra_data_lock()+0x0 when
 running -XX:+TraceDeoptimization -XX:-ProfileTraps -XX:-TieredCompilation
 -Xcomp -version

Reviewed-by: vlivanov, epeter
---
 src/hotspot/share/runtime/deoptimization.cpp  |  6 +-
 ...stPrintDiagnosticsWithoutProfileTraps.java | 58 +++++++++++++++++++
 2 files changed, 62 insertions(+), 2 deletions(-)
 create mode 100644 test/hotspot/jtreg/compiler/uncommontrap/TestPrintDiagnosticsWithoutProfileTraps.java

diff --git a/src/hotspot/share/runtime/deoptimization.cpp b/src/hotspot/share/runtime/deoptimization.cpp
index 2beba9abb06..54a65358693 100644
--- a/src/hotspot/share/runtime/deoptimization.cpp
+++ b/src/hotspot/share/runtime/deoptimization.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2026, 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
@@ -2155,7 +2155,9 @@ JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* current, jint tr
       // Lock to read ProfileData, and ensure lock is not broken by a safepoint
       // We must do this already now, since we cannot acquire this lock while
       // holding the tty lock (lock ordering by rank).
-      MutexLocker ml(trap_mdo->extra_data_lock(), Mutex::_no_safepoint_check_flag);
+      ConditionalMutexLocker ml((trap_mdo != nullptr) ? trap_mdo->extra_data_lock() : nullptr,
+                                (trap_mdo != nullptr),
+                                Mutex::_no_safepoint_check_flag);
 
       ttyLocker ttyl;
 
diff --git a/test/hotspot/jtreg/compiler/uncommontrap/TestPrintDiagnosticsWithoutProfileTraps.java b/test/hotspot/jtreg/compiler/uncommontrap/TestPrintDiagnosticsWithoutProfileTraps.java
new file mode 100644
index 00000000000..51b30219aca
--- /dev/null
+++ b/test/hotspot/jtreg/compiler/uncommontrap/TestPrintDiagnosticsWithoutProfileTraps.java
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2026, 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.
+ */
+
+ /**
+ * @test
+ * @bug 8374807
+ * @summary Regression test for -XX:+TraceDeoptimization -XX:-ProfileTraps
+ *          -XX:-TieredCompilation -Xcomp crash
+ * @modules java.base/jdk.internal.misc
+ * @requires vm.debug
+ * @run main/othervm -XX:+TraceDeoptimization -XX:-ProfileTraps
+ *                   -XX:-TieredCompilation -Xcomp -Xbatch
+ *                   -XX:CompileCommand=compileonly,compiler.uncommontrap.TestPrintDiagnosticsWithoutProfileTraps::test
+ *                   compiler.uncommontrap.TestPrintDiagnosticsWithoutProfileTraps
+ */
+
+package compiler.uncommontrap;
+
+import jdk.internal.misc.Unsafe;
+
+public class TestPrintDiagnosticsWithoutProfileTraps {
+    static final Unsafe UNSAFE=Unsafe.getUnsafe();
+    static volatile long sink;
+
+    static class TestSubClass {
+        int f;
+    }
+
+    static void test(){
+        // Trigger a deopt/uncommon-trap path while resolving the field offset.
+        sink = UNSAFE.objectFieldOffset(TestSubClass.class,"f");
+    }
+
+    public static void main(String[] args) {
+        test();
+        System.out.println("passed");
+    }
+}
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