From 15c1aa51d323728135251a6b75f21b720d7439fe Mon Sep 17 00:00:00 2001
From: kotori0 <admin@0x.mk>
Date: Thu, 5 Nov 2020 20:44:17 +0800
Subject: [PATCH] Get ClassLinker instance from art::Runtime

---
 .../cpp/main/include/art/runtime/class_linker.h  | 16 ++++++++++++++++
 .../main/cpp/main/include/art/runtime/runtime.h  |  3 +++
 2 files changed, 19 insertions(+)

diff --git a/edxp-core/src/main/cpp/main/include/art/runtime/class_linker.h b/edxp-core/src/main/cpp/main/include/art/runtime/class_linker.h
index 2c76d125..60d2aeef 100644
--- a/edxp-core/src/main/cpp/main/include/art/runtime/class_linker.h
+++ b/edxp-core/src/main/cpp/main/include/art/runtime/class_linker.h
@@ -23,6 +23,7 @@ namespace art {
         }
 
         CREATE_HOOK_STUB_ENTRIES(void *, Constructor, void *thiz, void *intern_table) {
+            LOGI("ConstructorReplace called");
             if (LIKELY(instance_))
                 instance_->Reset(thiz);
             else
@@ -62,6 +63,20 @@ namespace art {
 
         // @ApiSensitive(Level.MIDDLE)
         static void Setup(void *handle, HookFunType hook_func) {
+            LOGD("Classlinker hook setup, handle=%p", handle);
+            // TODO: Maybe not compatible with Android 10-
+#ifdef __LP64__
+            size_t OFFSET_classlinker = 472 / 8;
+#else
+            size_t OFFSET_classlinker = 276 / 4;
+#endif
+            // ClassLinker* GetClassLinker() but inlined
+            void* cl = reinterpret_cast<void*>(
+                    reinterpret_cast<size_t*>(Runtime::Current()->Get()) + OFFSET_classlinker
+            );
+            LOGD("Classlinker object: %p", cl);
+            instance_ = new ClassLinker(cl);
+
             HOOK_FUNC(Constructor, "_ZN3art11ClassLinkerC2EPNS_11InternTableE",
                       "_ZN3art11ClassLinkerC2EPNS_11InternTableEb"); // 10.0
             RETRIEVE_FUNC_SYMBOL(SetEntryPointsToInterpreter,
@@ -76,6 +91,7 @@ namespace art {
         }
 
         ALWAYS_INLINE void SetEntryPointsToInterpreter(void *art_method) const {
+            LOGD("SetEntryPointsToInterpreter start, thiz=%p, art_method=%p", thiz_, art_method);
             if (LIKELY(thiz_))
                 SetEntryPointsToInterpreter(thiz_, art_method);
         }
diff --git a/edxp-core/src/main/cpp/main/include/art/runtime/runtime.h b/edxp-core/src/main/cpp/main/include/art/runtime/runtime.h
index 7451aba2..2e3ddc35 100644
--- a/edxp-core/src/main/cpp/main/include/art/runtime/runtime.h
+++ b/edxp-core/src/main/cpp/main/include/art/runtime/runtime.h
@@ -41,6 +41,9 @@ namespace art {
             HOOK_FUNC(Init, "_ZN3art7Runtime4InitEONS_18RuntimeArgumentMapE");
             RETRIEVE_FUNC_SYMBOL(DeoptimizeBootImage,
                                  "_ZN3art7Runtime19DeoptimizeBootImageEv");
+            RETRIEVE_FIELD_SYMBOL(thiz, "_ZN3art7Runtime9instance_E");
+            LOGD("_ZN3art7Runtime9instance_E = %p", thiz);
+            instance_ = new Runtime(thiz);
         }
 
         ALWAYS_INLINE void DeoptimizeBootImage() const {