8328877: [JNI] The JNI Specification needs to address the limitations of integer UTF-8 String lengths

Reviewed-by: cjplummer, alanb

Author: David Holmes

src/hotspot/os/posix/dtrace/hotspot_jni.d

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 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
@@ -19,7 +19,7 @@
  * 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.
- *  
+ *
  */
 
 provider hotspot_jni {
@@ -129,7 +129,7 @@ provider hotspot_jni {
   probe CallNonvirtualVoidMethodA__return();
   probe CallNonvirtualVoidMethod__entry(void*, void*, void*, uintptr_t);
   probe CallNonvirtualVoidMethod__return();
-  probe CallNonvirtualVoidMethodV__entry(void*, void*, void*, uintptr_t);  
+  probe CallNonvirtualVoidMethodV__entry(void*, void*, void*, uintptr_t);
   probe CallNonvirtualVoidMethodV__return();
   probe CallObjectMethodA__entry(void*, void*, uintptr_t);
   probe CallObjectMethodA__return(void*);
@@ -200,14 +200,14 @@ provider hotspot_jni {
   probe CallStaticVoidMethodA__entry(void*, void*, uintptr_t);
   probe CallStaticVoidMethodA__return();
   probe CallStaticVoidMethod__entry(void*, void*, uintptr_t);
-  probe CallStaticVoidMethod__return(); 
-  probe CallStaticVoidMethodV__entry(void*, void*, uintptr_t);  
+  probe CallStaticVoidMethod__return();
+  probe CallStaticVoidMethodV__entry(void*, void*, uintptr_t);
   probe CallStaticVoidMethodV__return();
-  probe CallVoidMethodA__entry(void*, void*, uintptr_t);  
+  probe CallVoidMethodA__entry(void*, void*, uintptr_t);
   probe CallVoidMethodA__return();
-  probe CallVoidMethod__entry(void*, void*, uintptr_t);  
-  probe CallVoidMethod__return(); 
-  probe CallVoidMethodV__entry(void*, void*, uintptr_t);  
+  probe CallVoidMethod__entry(void*, void*, uintptr_t);
+  probe CallVoidMethod__return();
+  probe CallVoidMethodV__entry(void*, void*, uintptr_t);
   probe CallVoidMethodV__return();
   probe CreateJavaVM__entry(void**, void**, void*);
   probe CreateJavaVM__return(uint32_t);
@@ -229,7 +229,7 @@ provider hotspot_jni {
   probe ExceptionCheck__return(uintptr_t);
   probe ExceptionClear__entry(void*);
   probe ExceptionClear__return();
-  probe ExceptionDescribe__entry(void*);  
+  probe ExceptionDescribe__entry(void*);
   probe ExceptionDescribe__return();
   probe ExceptionOccurred__entry(void*);
   probe ExceptionOccurred__return(void*);
@@ -352,6 +352,8 @@ provider hotspot_jni {
   probe GetStringUTFChars__return(const char*);
   probe GetStringUTFLength__entry(void*, void*);
   probe GetStringUTFLength__return(uintptr_t);
+  probe GetStringUTFLengthAsLong__entry(void*, void*);
+  probe GetStringUTFLengthAsLong__return(uintptr_t);
   probe GetStringUTFRegion__entry(void*, void*, uintptr_t, uintptr_t, char*);
   probe GetStringUTFRegion__return();
   probe GetSuperclass__entry(void*, void*);
@@ -388,13 +390,13 @@ provider hotspot_jni {
   probe NewLocalRef__return(void*);
   probe NewLongArray__entry(void*, uintptr_t);
   probe NewLongArray__return(void*);
-  probe NewObjectA__entry(void*, void*, uintptr_t);  
+  probe NewObjectA__entry(void*, void*, uintptr_t);
   probe NewObjectA__return(void*);
   probe NewObjectArray__entry(void*, uintptr_t, void*, void*);
   probe NewObjectArray__return(void*);
-  probe NewObject__entry(void*, void*, uintptr_t); 
+  probe NewObject__entry(void*, void*, uintptr_t);
   probe NewObject__return(void*);
-  probe NewObjectV__entry(void*, void*, uintptr_t);  
+  probe NewObjectV__entry(void*, void*, uintptr_t);
   probe NewObjectV__return(void*);
   probe NewShortArray__entry(void*, uintptr_t);
   probe NewShortArray__return(void*);
@@ -408,7 +410,7 @@ provider hotspot_jni {
   probe PopLocalFrame__return(void*);
   probe PushLocalFrame__entry(void*, uint32_t);
   probe PushLocalFrame__return(uint32_t);
-  probe RegisterNatives__entry(void*, void*, const void*, uint32_t);  
+  probe RegisterNatives__entry(void*, void*, const void*, uint32_t);
   probe RegisterNatives__return(uint32_t);
   probe ReleaseBooleanArrayElements__entry(void*, void*, uintptr_t*, uint32_t);
   probe ReleaseBooleanArrayElements__return();
@@ -490,13 +492,13 @@ provider hotspot_jni {
   probe SetStaticShortField__return();
   probe Throw__entry(void*, void*);
   probe Throw__return(intptr_t);
-  probe ThrowNew__entry(void*, void*, const char*);  
-  probe ThrowNew__return(intptr_t);  
+  probe ThrowNew__entry(void*, void*, const char*);
+  probe ThrowNew__return(intptr_t);
   probe ToReflectedField__entry(void*, void*, uintptr_t, uintptr_t);
   probe ToReflectedField__return(void*);
   probe ToReflectedMethod__entry(void*, void*, uintptr_t, uintptr_t);
   probe ToReflectedMethod__return(void*);
-  probe UnregisterNatives__entry(void*, void*);  
+  probe UnregisterNatives__entry(void*, void*);
   probe UnregisterNatives__return(uint32_t);
 };
 
@@ -505,4 +507,3 @@ provider hotspot_jni {
 #pragma D attributes Private/Private/Unknown provider hotspot_jni function
 #pragma D attributes Standard/Standard/Common provider hotspot_jni name
 #pragma D attributes Evolving/Evolving/Common provider hotspot_jni args
-

src/hotspot/share/prims/jni.cpp

@@ -102,7 +102,7 @@
 #include "jfr/jfr.hpp"
 #endif
 
-static jint CurrentVersion = JNI_VERSION_21;
+static jint CurrentVersion = JNI_VERSION_24;
 
 #if defined(_WIN32) && !defined(USE_VECTORED_EXCEPTION_HANDLING)
 extern LONG WINAPI topLevelExceptionFilter(_EXCEPTION_POINTERS* );
@@ -2221,13 +2221,21 @@ JNI_END
 
 
 JNI_ENTRY(jsize, jni_GetStringUTFLength(JNIEnv *env, jstring string))
- HOTSPOT_JNI_GETSTRINGUTFLENGTH_ENTRY(env, string);
+  HOTSPOT_JNI_GETSTRINGUTFLENGTH_ENTRY(env, string);
   oop java_string = JNIHandles::resolve_non_null(string);
   jsize ret = java_lang_String::utf8_length_as_int(java_string);
   HOTSPOT_JNI_GETSTRINGUTFLENGTH_RETURN(ret);
   return ret;
 JNI_END
 
+JNI_ENTRY(jlong, jni_GetStringUTFLengthAsLong(JNIEnv *env, jstring string))
+  HOTSPOT_JNI_GETSTRINGUTFLENGTHASLONG_ENTRY(env, string);
+  oop java_string = JNIHandles::resolve_non_null(string);
+  size_t ret = java_lang_String::utf8_length(java_string);
+  HOTSPOT_JNI_GETSTRINGUTFLENGTHASLONG_RETURN(ret);
+return checked_cast<jlong>(ret);
+JNI_END
+
 
 JNI_ENTRY(const char*, jni_GetStringUTFChars(JNIEnv *env, jstring string, jboolean *isCopy))
  HOTSPOT_JNI_GETSTRINGUTFCHARS_ENTRY(env, string, (uintptr_t *) isCopy);
@@ -3398,7 +3406,11 @@ struct JNINativeInterface_ jni_NativeInterface = {
 
     // Virtual threads
 
-    jni_IsVirtualThread
+    jni_IsVirtualThread,
+
+    // Large UTF8 support
+
+    jni_GetStringUTFLengthAsLong
 };
 
 

src/hotspot/share/prims/jniCheck.cpp

@@ -1511,6 +1511,27 @@ JNI_ENTRY_CHECKED(jsize,
       checkString(thr, str);
     )
     jsize result = UNCHECKED()->GetStringUTFLength(env,str);
+    jlong full_length =  UNCHECKED()->GetStringUTFLengthAsLong(env,str);
+    if (full_length > result) {
+      ResourceMark rm(thr);
+      stringStream ss;
+      ss.print("WARNING: large String with modified UTF-8 length " JLONG_FORMAT
+                " is reporting a reduced length of %d - use GetStringUTFLengthAsLong instead",
+                full_length, result);
+      NativeReportJNIWarning(thr, ss.as_string());
+    }
+    functionExit(thr);
+    return result;
+JNI_END
+
+JNI_ENTRY_CHECKED(jlong,
+  checked_jni_GetStringUTFLengthAsLong(JNIEnv *env,
+                                       jstring str))
+    functionEnter(thr);
+    IN_VM(
+      checkString(thr, str);
+    )
+    jlong result = UNCHECKED()->GetStringUTFLengthAsLong(env,str);
     functionExit(thr);
     return result;
 JNI_END
@@ -2283,7 +2304,12 @@ struct JNINativeInterface_  checked_jni_NativeInterface = {
 
     // Virtual threads
 
-    checked_jni_IsVirtualThread
+    checked_jni_IsVirtualThread,
+
+    // Large UTF8 support
+
+    checked_jni_GetStringUTFLengthAsLong
+
 };
 
 

src/hotspot/share/runtime/threads.cpp

@@ -984,6 +984,7 @@ jboolean Threads::is_supported_jni_version(jint version) {
   if (version == JNI_VERSION_19) return JNI_TRUE;
   if (version == JNI_VERSION_20) return JNI_TRUE;
   if (version == JNI_VERSION_21) return JNI_TRUE;
+  if (version == JNI_VERSION_24) return JNI_TRUE;
   return JNI_FALSE;
 }
 

src/hotspot/share/utilities/dtrace_disabled.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 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
@@ -783,6 +783,10 @@
 #define HOTSPOT_JNI_GETSTRINGUTFLENGTH_ENTRY_ENABLED()  0
 #define HOTSPOT_JNI_GETSTRINGUTFLENGTH_RETURN(arg0)
 #define HOTSPOT_JNI_GETSTRINGUTFLENGTH_RETURN_ENABLED()  0
+#define HOTSPOT_JNI_GETSTRINGUTFLENGTHASLONG_ENTRY(arg0, arg1)
+#define HOTSPOT_JNI_GETSTRINGUTFLENGTHASLONG_ENTRY_ENABLED()  0
+#define HOTSPOT_JNI_GETSTRINGUTFLENGTHASLONG_RETURN(arg0)
+#define HOTSPOT_JNI_GETSTRINGUTFLENGTHASLONG_RETURN_ENABLED()  0
 #define HOTSPOT_JNI_GETSTRINGUTFREGION_ENTRY(arg0, arg1, arg2, arg3, arg4)
 #define HOTSPOT_JNI_GETSTRINGUTFREGION_ENTRY_ENABLED()  0
 #define HOTSPOT_JNI_GETSTRINGUTFREGION_RETURN()

src/java.base/share/native/include/jni.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1996, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 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
@@ -775,6 +775,12 @@ struct JNINativeInterface_ {
 
     jboolean (JNICALL *IsVirtualThread)
        (JNIEnv* env, jobject obj);
+
+    /* Large UTF8 Support */
+
+    jlong (JNICALL *GetStringUTFLengthAsLong)
+      (JNIEnv *env, jstring str);
+
 };
 
 /*
@@ -1623,6 +1629,9 @@ struct JNIEnv_ {
     jsize GetStringUTFLength(jstring str) {
         return functions->GetStringUTFLength(this,str);
     }
+    jlong GetStringUTFLengthAsLong(jstring str) {
+        return functions->GetStringUTFLengthAsLong(this,str);
+    }
     const char* GetStringUTFChars(jstring str, jboolean *isCopy) {
         return functions->GetStringUTFChars(this,str,isCopy);
     }
@@ -1993,6 +2002,7 @@ JNI_OnUnload(JavaVM *vm, void *reserved);
 #define JNI_VERSION_19  0x00130000
 #define JNI_VERSION_20  0x00140000
 #define JNI_VERSION_21  0x00150000
+#define JNI_VERSION_24  0x00180000
 
 #ifdef __cplusplus
 } /* extern "C" */

test/hotspot/jtreg/native_sanity/JniVersion.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 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
@@ -27,12 +27,12 @@
  */
 public class JniVersion {
 
-    public static final int JNI_VERSION_21 = 0x00150000;
+    public static final int JNI_VERSION_24 = 0x00180000;
 
     public static void main(String... args) throws Exception {
         System.loadLibrary("JniVersion");
         int res = getJniVersion();
-        if (res != JNI_VERSION_21) {
+        if (res != JNI_VERSION_24) {
             throw new Exception("Unexpected value returned from getJniVersion(): 0x" + Integer.toHexString(res));
         }
     }

test/hotspot/jtreg/runtime/jni/checked/TestLargeUTF8Length.java

@@ -0,0 +1,73 @@
+/*
+ * 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.
+ */
+
+/* @test
+ * @bug 8328877
+ * @summary Test warning for GetStringUTFLength and functionality of GetStringUTFLengthAsLong
+ * @requires vm.bits == 64
+ * @library /test/lib
+ * @modules java.management
+ * @run main/native TestLargeUTF8Length launch
+ */
+
+import java.util.Arrays;
+import jdk.test.lib.Utils;
+import jdk.test.lib.process.ProcessTools;
+import jdk.test.lib.process.OutputAnalyzer;
+
+public class TestLargeUTF8Length {
+
+    static {
+        System.loadLibrary("TestLargeUTF8Length");
+    }
+
+    static native void checkUTF8Length(String s, long utf8Length);
+
+    static void test() {
+        int length = Integer.MAX_VALUE/2 + 1;
+        char character = (char)0XD1; // N with tilde
+        long utf8Length = 2L * length;
+        char[] chrs = new char[length];
+        Arrays.fill(chrs, character);
+        String s = new String(chrs);
+        checkUTF8Length(s, utf8Length);
+    }
+
+    public static void main(String[] args) throws Throwable {
+        if (args == null || args.length == 0) {
+            test();
+            return;
+        }
+
+        OutputAnalyzer oa = ProcessTools.executeTestJava("-Xms9G",
+                                                         "-Xmx9G",
+                                                         "-Xcheck:jni",
+                                                         "-Djava.library.path=" + Utils.TEST_NATIVE_PATH,
+                                                         "TestLargeUTF8Length");
+        String warning = "WARNING: large String with modified UTF-8 length .*" +
+                         "is reporting a reduced length of .* - use GetStringUTFLengthAsLong instead";
+        oa.shouldHaveExitValue(0);
+        oa.stdoutShouldMatch(warning);
+        oa.reportDiagnosticSummary();
+    }
+}