Support SetRuntimeDebugState (#24)

build.gradle.kts

@@ -2,5 +2,5 @@ val androidTargetSdkVersion by extra(33)
 val androidMinSdkVersion by extra(21)
 val androidBuildToolsVersion by extra("33.0.0")
 val androidCompileSdkVersion by extra(33)
-val androidNdkVersion by extra("24.0.8215888")
+val androidNdkVersion by extra("25.1.8937393")
 val androidCmakeVersion by extra("3.22.1+")

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.4.2-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.5.1-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

lsplant/build.gradle.kts

@@ -114,7 +114,7 @@ publishing {
         register<MavenPublication>("lsplant") {
             group = "org.lsposed.lsplant"
             artifactId = "lsplant"
-            version = "4.1"
+            version = "4.2"
             afterEvaluate {
                 from(components.getByName("release"))
                 artifact(symbolsTask)

lsplant/src/main/jni/art/runtime/runtime.hpp

@@ -24,19 +24,46 @@
 namespace lsplant::art {
 
 class Runtime {
+public:
+    enum class RuntimeDebugState {
+        // This doesn't support any debug features / method tracing. This is the expected state
+        // usually.
+        kNonJavaDebuggable,
+        // This supports method tracing and a restricted set of debug features (for ex: redefinition
+        // isn't supported). We transition to this state when method tracing has started or when the
+        // debugger was attached and transition back to NonDebuggable once the tracing has stopped /
+        // the debugger agent has detached..
+        kJavaDebuggable,
+        // The runtime was started as a debuggable runtime. This allows us to support the extended
+        // set
+        // of debug features (for ex: redefinition). We never transition out of this state.
+        kJavaDebuggableAtInit
+    };
+
 private:
     inline static Runtime *instance_;
 
     CREATE_MEM_FUNC_SYMBOL_ENTRY(void, SetJavaDebuggable, void *thiz, bool value) {
-        if (SetJavaDebuggableSym) [[likely]] {
         SetJavaDebuggableSym(thiz, value);
     }
+
+    CREATE_MEM_FUNC_SYMBOL_ENTRY(void, SetRuntimeDebugState, void *thiz, RuntimeDebugState value) {
+        SetRuntimeDebugStateSym(thiz, value);
     }
 
+    inline static size_t debug_state_offset = 0U;
+
 public:
     inline static Runtime *Current() { return instance_; }
 
-    void SetJavaDebuggable(bool value) { SetJavaDebuggable(this, value); }
+    void SetJavaDebuggable(RuntimeDebugState value) {
+        if (SetJavaDebuggableSym) {
+            SetJavaDebuggable(this, value != RuntimeDebugState::kNonJavaDebuggable);
+        } else if (debug_state_offset > 0) {
+            *reinterpret_cast<RuntimeDebugState *>(reinterpret_cast<uintptr_t>(instance_) +
+                                                   debug_state_offset) = value;
+        }
+    }
 
     static bool Init(const HookHandler &handler) {
         int sdk_int = GetAndroidApiLevel();
@@ -48,7 +75,32 @@ public:
         LOGD("runtime instance = %p", instance_);
         if (sdk_int >= __ANDROID_API_O__) {
             if (!RETRIEVE_MEM_FUNC_SYMBOL(SetJavaDebuggable,
-                                          "_ZN3art7Runtime17SetJavaDebuggableEb")) {
+                                          "_ZN3art7Runtime17SetJavaDebuggableEb") &&
+                !RETRIEVE_MEM_FUNC_SYMBOL(
+                    SetRuntimeDebugState,
+                    "_ZN3art7Runtime20SetRuntimeDebugStateENS0_17RuntimeDebugStateE")) {
+                return false;
+            }
+        }
+        if (SetRuntimeDebugStateSym) {
+            static constexpr size_t kLargeEnoughSizeForRuntime = 4096;
+            std::array<uint8_t, kLargeEnoughSizeForRuntime> code;
+            static_assert(static_cast<int>(RuntimeDebugState::kJavaDebuggable) != 0);
+            static_assert(static_cast<int>(RuntimeDebugState::kJavaDebuggableAtInit) != 0);
+            code.fill(uint8_t{0});
+            auto *const fake_runtime = reinterpret_cast<Runtime *>(code.data());
+            SetRuntimeDebugState(fake_runtime, RuntimeDebugState::kJavaDebuggable);
+            for (size_t i = 0; i < kLargeEnoughSizeForRuntime; ++i) {
+                if (*reinterpret_cast<RuntimeDebugState *>(
+                        reinterpret_cast<uintptr_t>(fake_runtime) + i) ==
+                    RuntimeDebugState::kJavaDebuggable) {
+                    LOGD("found debug_state at offset %zu", i);
+                    debug_state_offset = i;
+                    break;
+                }
+            }
+            if (debug_state_offset == 0) {
+                LOGE("failed to find debug_state");
                 return false;
             }
         }

lsplant/src/main/jni/lsplant.cc

@@ -274,7 +274,7 @@ bool InitNative(JNIEnv *env, const HookHandler &handler) {
     if (IsJavaDebuggable(env)) {
         // Make the runtime non-debuggable as a workaround
         // when ShouldUseInterpreterEntrypoint inlined
-        Runtime::Current()->SetJavaDebuggable(false);
+        Runtime::Current()->SetJavaDebuggable(Runtime::RuntimeDebugState::kNonJavaDebuggable);
     }
     return true;
 }
@@ -735,8 +735,13 @@ using ::lsplant::IsHooked;
 
 [[maybe_unused]] bool MakeDexFileTrusted(JNIEnv *env, jobject cookie) {
     struct Guard {
-        Guard() { Runtime::Current()->SetJavaDebuggable(true); }
+        Guard() {
-        ~Guard() { Runtime::Current()->SetJavaDebuggable(false); }
+            Runtime::Current()->SetJavaDebuggable(
+                Runtime::RuntimeDebugState::kJavaDebuggableAtInit);
+        }
+        ~Guard() {
+            Runtime::Current()->SetJavaDebuggable(Runtime::RuntimeDebugState::kNonJavaDebuggable);
+        }
     } guard;
     if (!cookie) return false;
     return DexFile::SetTrusted(env, cookie);

settings.gradle.kts

@@ -5,8 +5,8 @@ pluginManagement {
         mavenCentral()
     }
     plugins {
-        id("com.android.application") version "7.2.1"
+        id("com.android.application") version "7.2.2"
-        id("com.android.library") version "7.2.1"
+        id("com.android.library") version "7.2.2"
     }
 }
 dependencyResolutionManagement {