[GR-42467] Add support for loading libraries from directory containing native image.

docs/reference-manual/native-image/JNI.md

@@ -19,6 +19,7 @@ The Native Image JNI implementation supports both approaches.
 
 ### Table of Contents
 
+* [Loading Native Libraries](#loading-native-libraries)
 * [Reflection Metadata](#reflection-metadata)
 * [Object Handles](#object-handles)
 * [Java-to-Native Method Calls](#java-to-native-method-calls)
@@ -29,6 +30,12 @@ The Native Image JNI implementation supports both approaches.
 * [Exceptions](#exceptions)
 * [Monitors](#monitors)
 
+## Loading Native Libraries
+
+When loading native libraries using `System.loadLibrary()` (and related APIs), the native image will search the
+directory containing the native image before searching the Java library path. So as long as the native libraries
+to be loaded are in the same directory as the native image, no other settings should be necessary.
+
 ## Reflection Metadata
 
 JNI supports looking up classes by their names, and looking up methods and fields by their names and signatures.
@@ -187,4 +194,4 @@ For that reason, it can be beneficial to wrap synchronization in Java code.
 
 - [Interoperability with Native Code](InteropWithNativeCode.md)
 - [JNI Invocation API](JNIInvocationAPI.md)
-- [Reachability Metadata: Java Native Interface](ReachabilityMetadata.md#java-native-interface)
+- [Reachability Metadata: Java Native Interface](ReachabilityMetadata.md#java-native-interface)

docs/security/security-guide.md

@@ -118,6 +118,8 @@ See the [documentation](../reference-manual/native-image/CertificateManagement.m
 
 In addition, developers can run the `native-image` builder in a dedicated environment, such as a container, that does not contain any sensitive information in the first place.
 
+The directory containing the native image is part of the search path when loading native libraries using `System.loadLibrary()` at runtime.
+
 ### Serialization in Native Image
 
 Native Image supports Serialization to help users deserialize the constructors for classes, contained in a native executable in the first place.

sdk/src/org.graalvm.nativeimage/src/org/graalvm/nativeimage/impl/ProcessPropertiesSupport.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * The Universal Permissive License (UPL), Version 1.0
@@ -44,6 +44,7 @@
 import java.util.Map;
 
 import org.graalvm.nativeimage.c.function.CEntryPointLiteral;
+import org.graalvm.word.PointerBase;
 
 public interface ProcessPropertiesSupport {
     String getExecutableName();
@@ -54,7 +55,14 @@ public interface ProcessPropertiesSupport {
 
     String getObjectFile(String symbol);
 
-    String getObjectFile(CEntryPointLiteral<?> symbol);
+    default String getObjectFile(CEntryPointLiteral<?> symbol) {
+        return getObjectFile(symbol.getFunctionPointer());
+    }
+
+    @SuppressWarnings("unused")
+    default String getObjectFile(PointerBase symbolAddress) {
+        return null;
+    }
 
     String setLocale(String category, String locale);
 

substratevm/CHANGELOG.md

@@ -18,6 +18,7 @@ This changelog summarizes major changes to GraalVM Native Image.
 * (GR-19890) Native Image now sets up build environments for Windows users automatically. Running in an x64 Native Tools Command Prompt is no longer a requirement.
 * (GR-43410) Added support for the JFR event `ExecutionSample`.
 * (GR-44058) Red Hat added support for the JFR event `ObjectAllocationInNewTLAB`.
+* (GR-42467) The search path for `System.loadLibrary()` by default includes the directory containing the native image.
 
 ## Version 22.3.0
 * (GR-35721) Remove old build output style and the `-H:±BuildOutputUseNewStyle` option.

substratevm/src/com.oracle.svm.core.posix/src/com/oracle/svm/core/posix/PosixProcessPropertiesSupport.java

@@ -33,7 +33,6 @@
 import java.util.Map.Entry;
 import java.util.stream.Collectors;
 
-import org.graalvm.nativeimage.c.function.CEntryPointLiteral;
 import org.graalvm.nativeimage.c.type.CCharPointer;
 import org.graalvm.nativeimage.c.type.CTypeConversion;
 import org.graalvm.nativeimage.c.type.CTypeConversion.CCharPointerHolder;
@@ -82,12 +81,30 @@ public int waitForProcessExit(long processID) {
 
     @Override
     public String getObjectFile(String symbol) {
-        return getObjectPathDefiningSymbol(symbol);
+        try (CTypeConversion.CCharPointerHolder symbolHolder = CTypeConversion.toCString(symbol)) {
+            PointerBase symbolAddress = Dlfcn.dlsym(Dlfcn.RTLD_DEFAULT(), symbolHolder.get());
+            if (symbolAddress.isNull()) {
+                return null;
+            }
+            return getObjectFile(symbolAddress);
+        }
     }
 
     @Override
-    public String getObjectFile(CEntryPointLiteral<?> symbol) {
-        return getObjectPathDefiningAddress(symbol.getFunctionPointer());
+    public String getObjectFile(PointerBase symbolAddress) {
+        Dlfcn.Dl_info info = UnsafeStackValue.get(Dlfcn.Dl_info.class);
+        if (Dlfcn.dladdr(symbolAddress, info) == 0) {
+            return null;
+        }
+        CCharPointer realpath = Stdlib.realpath(info.dli_fname(), WordFactory.nullPointer());
+        if (realpath.isNull()) {
+            return null;
+        }
+        try {
+            return CTypeConversion.toJavaString(realpath);
+        } finally {
+            LibC.free(realpath);
+        }
     }
 
     @Override
@@ -133,32 +150,6 @@ public void exec(Path executable, String[] args, Map<String, String> env) {
         }
     }
 
-    static String getObjectPathDefiningSymbol(String symbol) {
-        try (CTypeConversion.CCharPointerHolder symbolHolder = CTypeConversion.toCString(symbol)) {
-            PointerBase symbolAddress = Dlfcn.dlsym(Dlfcn.RTLD_DEFAULT(), symbolHolder.get());
-            if (symbolAddress.isNull()) {
-                return null;
-            }
-            return getObjectPathDefiningAddress(symbolAddress);
-        }
-    }
-
-    static String getObjectPathDefiningAddress(PointerBase symbolAddress) {
-        Dlfcn.Dl_info info = UnsafeStackValue.get(Dlfcn.Dl_info.class);
-        if (Dlfcn.dladdr(symbolAddress, info) == 0) {
-            return null;
-        }
-        CCharPointer realpath = Stdlib.realpath(info.dli_fname(), WordFactory.nullPointer());
-        if (realpath.isNull()) {
-            return null;
-        }
-        try {
-            return CTypeConversion.toJavaString(realpath);
-        } finally {
-            LibC.free(realpath);
-        }
-    }
-
     /** A platform-independent method to canonicalize a path. */
     protected static String realpath(String path) {
         /*

substratevm/src/com.oracle.svm.core.windows/src/com/oracle/svm/core/windows/WindowsProcessPropertiesSupport.java

@@ -32,7 +32,6 @@
 import java.util.List;
 import java.util.Map;
 
-import org.graalvm.nativeimage.c.function.CEntryPointLiteral;
 import org.graalvm.nativeimage.c.type.CCharPointer;
 import org.graalvm.nativeimage.c.type.CTypeConversion;
 import org.graalvm.nativeimage.impl.ProcessPropertiesSupport;
@@ -47,16 +46,14 @@
 import com.oracle.svm.core.windows.headers.Process;
 import com.oracle.svm.core.windows.headers.WinBase;
 import com.oracle.svm.core.windows.headers.WinBase.HANDLE;
+import com.oracle.svm.core.windows.headers.WindowsLibC.WCharPointer;
 
 @AutomaticallyRegisteredImageSingleton(ProcessPropertiesSupport.class)
 public class WindowsProcessPropertiesSupport extends BaseProcessPropertiesSupport {
 
     @Override
     public String getExecutableName() {
-        CCharPointer path = UnsafeStackValue.get(WinBase.MAX_PATH, CCharPointer.class);
-        WinBase.HMODULE hModule = LibLoaderAPI.GetModuleHandleA(WordFactory.nullPointer());
-        int result = LibLoaderAPI.GetModuleFileNameA(hModule, path, WinBase.MAX_PATH);
-        return result == 0 ? null : CTypeConversion.toJavaString(path);
+        return getModulePath(LibLoaderAPI.GetModuleHandleA(WordFactory.nullPointer()));
     }
 
     @Override
@@ -117,21 +114,22 @@ public String getObjectFile(String symbol) {
     }
 
     @Override
-    public String getObjectFile(CEntryPointLiteral<?> symbol) {
-        PointerBase symbolAddress = symbol.getFunctionPointer();
-        return getObjectFile(symbolAddress);
-    }
-
-    private static String getObjectFile(PointerBase symbolAddress) {
+    public String getObjectFile(PointerBase symbolAddress) {
         WinBase.HMODULEPointer module = UnsafeStackValue.get(WinBase.HMODULEPointer.class);
         if (LibLoaderAPI.GetModuleHandleExA(LibLoaderAPI.GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS() | LibLoaderAPI.GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT(),
                         (CCharPointer) symbolAddress, module) == 0) {
             return null;
         }
+        return getModulePath(module.read());
+    }
 
-        CCharPointer path = UnsafeStackValue.get(WinBase.MAX_PATH, CCharPointer.class);
-        int result = LibLoaderAPI.GetModuleFileNameA(module.read(), path, WinBase.MAX_PATH);
-        return result == 0 ? null : CTypeConversion.toJavaString(path);
+    private static String getModulePath(WinBase.HMODULE module) {
+        WCharPointer path = UnsafeStackValue.get(WinBase.MAX_PATH, WCharPointer.class);
+        int length = LibLoaderAPI.GetModuleFileNameW(module, path, WinBase.MAX_PATH);
+        if (length == 0 || length == WinBase.MAX_PATH) {
+            return null;
+        }
+        return WindowsSystemPropertiesSupport.toJavaString(path, length);
     }
 
     @Override

substratevm/src/com.oracle.svm.core.windows/src/com/oracle/svm/core/windows/WindowsSystemPropertiesSupport.java

@@ -182,7 +182,7 @@ protected String javaLibraryPathValue() {
         return libraryPath.toString();
     }
 
-    private static String toJavaString(WCharPointer wcString, int length) {
+    static String toJavaString(WCharPointer wcString, int length) {
         return asCharBuffer(wcString, length).toString();
     }
 

substratevm/src/com.oracle.svm.core.windows/src/com/oracle/svm/core/windows/headers/LibLoaderAPI.java

@@ -32,9 +32,9 @@
 import org.graalvm.nativeimage.c.type.CCharPointer;
 import org.graalvm.word.PointerBase;
 
-import com.oracle.svm.core.windows.headers.WindowsLibC.WCharPointer;
 import com.oracle.svm.core.windows.headers.WinBase.HMODULE;
 import com.oracle.svm.core.windows.headers.WinBase.HMODULEPointer;
+import com.oracle.svm.core.windows.headers.WindowsLibC.WCharPointer;
 
 // Checkstyle: stop
 
@@ -48,10 +48,6 @@ public class LibLoaderAPI {
     @CFunction(transition = NO_TRANSITION)
     public static native int FreeLibrary(HMODULE hLibModule);
 
-    /** Retrieves the fully qualified path of the file that contains the specified module. */
-    @CFunction(transition = NO_TRANSITION)
-    public static native int GetModuleFileNameA(HMODULE hModule, CCharPointer lpFilename, int nSize);
-
     /** Retrieves the fully qualified path of the file that contains the specified module. */
     @CFunction(transition = NO_TRANSITION)
     public static native int GetModuleFileNameW(HMODULE hModule, WCharPointer lpFilename, int nSize);

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/NativeLibrarySupport.java

@@ -35,12 +35,17 @@
 import org.graalvm.nativeimage.ImageSingletons;
 import org.graalvm.nativeimage.Platform.HOSTED_ONLY;
 import org.graalvm.nativeimage.Platforms;
+import org.graalvm.nativeimage.ProcessProperties;
+import org.graalvm.nativeimage.impl.ProcessPropertiesSupport;
 import org.graalvm.word.PointerBase;
 import org.graalvm.word.WordFactory;
 
+import com.oracle.svm.core.NeverInline;
+import com.oracle.svm.core.SubstrateOptions;
 import com.oracle.svm.core.SubstrateUtil;
-import com.oracle.svm.core.jdk.PlatformNativeLibrarySupport.NativeLibrary;
 import com.oracle.svm.core.feature.AutomaticallyRegisteredImageSingleton;
+import com.oracle.svm.core.jdk.PlatformNativeLibrarySupport.NativeLibrary;
+import com.oracle.svm.core.snippets.KnownIntrinsics;
 
 @AutomaticallyRegisteredImageSingleton
 public final class NativeLibrarySupport {
@@ -62,7 +67,10 @@ public static NativeLibrarySupport singleton() {
 
     private final Deque<NativeLibrary> currentLoadContext = new ArrayDeque<>();
 
-    private String[] paths;
+    /** The path of the directory containing the native image. */
+    private String sysPath;
+    /** Paths derived from the {@code java.library.path} system property. */
+    private String[] usrPaths;
 
     private LibraryInitializer libraryInitializer;
 
@@ -97,17 +105,25 @@ public void loadLibraryRelative(String name) {
         if (loadLibrary0(new File(name), true)) {
             return;
         }
-        String libname = System.mapLibraryName(name);
-        if (paths == null) {
+        if (usrPaths == null) {
+            /*
+             * Note that `sysPath` will be `null` if we fail to get the image directory in which
+             * case we effectively fall back to using only `usrPaths`.
+             */
+            sysPath = getImageDirectory();
             String[] tokens = SubstrateUtil.split(System.getProperty("java.library.path", ""), File.pathSeparator);
             for (int i = 0; i < tokens.length; i++) {
                 if (tokens[i].isEmpty()) {
                     tokens[i] = ".";
                 }
             }
-            paths = tokens;
+            usrPaths = tokens;
+        }
+        String libname = System.mapLibraryName(name);
+        if (sysPath != null && loadLibrary0(new File(sysPath, libname), false)) {
+            return;
         }
-        for (String path : paths) {
+        for (String path : usrPaths) {
             File libpath = new File(path, libname);
             if (loadLibrary0(libpath, false)) {
                 return;
@@ -120,6 +136,20 @@ public void loadLibraryRelative(String name) {
         throw new UnsatisfiedLinkError("no " + name + " in java.library.path");
     }
 
+    /** Returns the directory containing the native image, or {@code null}. */
+    @NeverInline("Reads the return address.")
+    private static String getImageDirectory() {
+        /*
+         * While one might expect code for shared libraries to work for executables as well, this is
+         * not necessarily the case. For example, `dladdr` on Linux returns `argv[0]` for
+         * executables, which is completely useless when running an executable from `$PATH`, since
+         * then `argv[0]` contains only the name of the executable.
+         */
+        String image = !SubstrateOptions.SharedLibrary.getValue() ? ProcessProperties.getExecutableName()
+                        : ImageSingletons.lookup(ProcessPropertiesSupport.class).getObjectFile(KnownIntrinsics.readReturnAddress());
+        return image != null ? new File(image).getParent() : null;
+    }
+
     private boolean loadLibrary0(File file, boolean asBuiltin) {
         String canonical;
         try {