Update ClassLoader.findNative to support JEP 472

A new version of ClassLoader.findNative has been introduced, which accepts the Java method name and the Java class where the native method is declared as input parameters. It performs native access checks to comply with JEP 472 (Prepare to Restrict the Use of JNI). Related: #19680 Related: #20354 Signed-off-by: Babneet Singh <[email protected]>
eclipse-openj9 · Dec 16, 2024 · 6f9e4d2 · 6f9e4d2
1 parent a6331e7
commit 6f9e4d2
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Showing 4 changed files with 45 additions and 11 deletions.
diff --git a/jcl/src/java.base/share/classes/java/lang/Access.java b/jcl/src/java.base/share/classes/java/lang/Access.java
@@ -592,7 +592,7 @@ public PrintStream initialSystemErr() {
 /*[ENDIF] JAVA_SPEC_VERSION >= 23 */
 
 	public long findNative(ClassLoader loader, String entryName) {
-		return ClassLoader.findNative(loader, entryName);
+		return ClassLoader.findNative0(loader, entryName);
 	}
 
 	@Override

diff --git a/jcl/src/java.base/share/classes/java/lang/ClassLoader.java b/jcl/src/java.base/share/classes/java/lang/ClassLoader.java
@@ -72,6 +72,10 @@
 import jdk.internal.reflect.CallerSensitiveAdapter;
 /*[ENDIF] JAVA_SPEC_VERSION >= 18 */
 
+/*[IF JAVA_SPEC_VERSION >= 24]*/
+import jdk.internal.reflect.Reflection;
+/*[ENDIF] JAVA_SPEC_VERSION >= 24 */
+
 /*[IF CRIU_SUPPORT]*/
 import openj9.internal.criu.NotCheckpointSafe;
 /*[ENDIF] CRIU_SUPPORT*/
@@ -2101,13 +2105,27 @@ static void loadLibrary(Class<?> caller, String libName) {
 	}
 }
 
-static long findNative(ClassLoader loader, String entryName) {
+/*[IF JAVA_SPEC_VERSION >= 24]*/
+static long findNative1(ClassLoader loader, String entryName, Class<?> cls, String javaName) {
+	long address = findNative0(loader, entryName);
+
+	if ((loader != null) && (address != 0)) {
+		Reflection.ensureNativeAccess(cls, cls, javaName, true);
+	}
+
+	return address;
+}
+/*[ENDIF] JAVA_SPEC_VERSION >= 24 */
+
+static long findNative0(ClassLoader loader, String entryName) {
 	NativeLibraries nativelib;
+
 	if ((loader == null) || (loader == bootstrapClassLoader)) {
 		nativelib = BootLoader.getNativeLibraries();
 	} else {
 		nativelib = loader.nativelibs;
 	}
+
 	return nativelib.find(entryName);
 }
 /*[ENDIF] JAVA_SPEC_VERSION >= 15 */

diff --git a/runtime/oti/vmconstantpool.xml b/runtime/oti/vmconstantpool.xml
@@ -474,7 +474,8 @@ SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0-only WITH Classpath-ex
 	<virtualmethodref class="java/lang/ClassLoader" name="loadClass" signature="(Ljava/lang/String;)Ljava/lang/Class;"/>
 	<specialmethodref class="java/lang/Thread" name="uncaughtException" signature="(Ljava/lang/Throwable;)V"/>
 	<specialmethodref class="java/lang/Thread" name="&lt;init>" signature="(Ljava/lang/String;Ljava/lang/Object;IZ)V"/>
-	<staticmethodref class="java/lang/ClassLoader" name="findNative" signature="(Ljava/lang/ClassLoader;Ljava/lang/String;)J" versions="17-"/>
+	<staticmethodref class="java/lang/ClassLoader" name="findNative0" signature="(Ljava/lang/ClassLoader;Ljava/lang/String;)J" versions="17-23"/>
+	<staticmethodref class="java/lang/ClassLoader" name="findNative1" signature="(Ljava/lang/ClassLoader;Ljava/lang/String;Ljava/lang/Class;Ljava/lang/String;)J" versions="24-"/>
 
 	<fieldref class="java/lang/J9VMInternals$ClassInitializationLock" name="theClass" signature="Ljava/lang/Class;"/>
 

diff --git a/runtime/vm/bindnatv.cpp b/runtime/vm/bindnatv.cpp
@@ -1105,17 +1105,32 @@ lookupJNINative(J9VMThread *currentThread, J9NativeLibrary *nativeLibrary, J9Met
 #if JAVA_SPEC_VERSION >= 17
 	if (NULL == nativeLibrary) {
 		internalAcquireVMAccess(currentThread);
-		j9object_t entryName = vm->memoryManagerFunctions->j9gc_createJavaLangString(currentThread, (U_8*)symbolName, strlen(symbolName), 0);
+		J9MemoryManagerFunctions *mmFuncs = vm->memoryManagerFunctions;
+		j9object_t entryName = mmFuncs->j9gc_createJavaLangString(currentThread, (U_8*)symbolName, strlen(symbolName), 0);
 		if (NULL != entryName) {
-			j9object_t classLoaderObject = J9_CLASS_FROM_METHOD(nativeMethod)->classLoader->classLoaderObject;
-			J9Method *findNativeMethod = J9VMJAVALANGCLASSLOADER_FINDNATIVE_METHOD(vm);
-			UDATA args[] = {(UDATA)classLoaderObject, (UDATA)entryName};
-			internalRunStaticMethod(currentThread, findNativeMethod, TRUE, (sizeof(args) / sizeof(UDATA)), args);
-			functionAddress = (UDATA*)(*(U_64*)&(currentThread->returnValue));
+#if JAVA_SPEC_VERSION >= 24
+			J9ROMMethod *nativeROMMethod = J9_ROM_METHOD_FROM_RAM_METHOD(nativeMethod);
+			j9object_t javaName = mmFuncs->j9gc_createJavaLangStringWithUTFCache(currentThread, J9ROMMETHOD_NAME(nativeROMMethod));
+			if (NULL != javaName)
+#endif /* JAVA_SPEC_VERSION >= 24 */
+			{
+				J9Class *nativeMethodCls = J9_CLASS_FROM_METHOD(nativeMethod);
+				j9object_t classLoaderObject = nativeMethodCls->classLoader->classLoaderObject;
+#if JAVA_SPEC_VERSION >= 24
+				j9object_t classObject = nativeMethodCls->classObject;
+				J9Method *findNativeMethod = J9VMJAVALANGCLASSLOADER_FINDNATIVE1_METHOD(vm);
+				UDATA args[] = {(UDATA)classLoaderObject, (UDATA)entryName, (UDATA)classObject, (UDATA)javaName};
+#else /* JAVA_SPEC_VERSION >= 24 */
+				J9Method *findNativeMethod = J9VMJAVALANGCLASSLOADER_FINDNATIVE0_METHOD(vm);
+				UDATA args[] = {(UDATA)classLoaderObject, (UDATA)entryName};
+#endif /* JAVA_SPEC_VERSION >= 24 */
+				internalRunStaticMethod(currentThread, findNativeMethod, TRUE, (sizeof(args) / sizeof(UDATA)), args);
+				functionAddress = (UDATA*)(*(U_64*)&(currentThread->returnValue));
 #if defined(J9VM_OPT_JAVA_OFFLOAD_SUPPORT)
-			doSwitching = ((UDATA)functionAddress) & J9_NATIVE_LIBRARY_SWITCH_MASK;
-			functionAddress = (UDATA *)(((UDATA)functionAddress) & ~(UDATA)J9_NATIVE_LIBRARY_SWITCH_MASK);
+				doSwitching = ((UDATA)functionAddress) & J9_NATIVE_LIBRARY_SWITCH_MASK;
+				functionAddress = (UDATA *)(((UDATA)functionAddress) & ~(UDATA)J9_NATIVE_LIBRARY_SWITCH_MASK);
 #endif /* defined(J9VM_OPT_JAVA_OFFLOAD_SUPPORT) */
+			}
 		}
 		/* always clear pending exception, might retry later */
 		VM_VMHelpers::clearException(currentThread);