From dc2d9905f3f8c3913921248fd5fcf8c873c89264 Mon Sep 17 00:00:00 2001
From: Patrick Williams <pdwilliams@google.com>
Date: Wed, 19 Apr 2023 16:30:22 -0500
Subject: [PATCH] Check exceptions in BBQ and SC JNI code

Updates the following callback wrappers to crash the client when
exceptions are thrown:

* TransactionCommittedListenerWrapper
* TransactionHangCallbackWrapper
* TrustedPresentationCallbackWrapper
* WindowInfosReportedListenerWrapper

This prevents misleading error messages where a later JNI call fails due
to a pending Java exception.

Bug: 278526360
Bug: 278573545
Test: presubmits
Change-Id: I796e46640b6d1ab43152de9040cbc4b7f25addb9
---
 core/jni/android_graphics_BLASTBufferQueue.cpp | 14 ++++++++------
 core/jni/android_view_SurfaceControl.cpp       |  3 +++
 core/jni/core_jni_helpers.h                    |  9 +++++++++
 3 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/core/jni/android_graphics_BLASTBufferQueue.cpp b/core/jni/android_graphics_BLASTBufferQueue.cpp
index 55aa7117221ea..4474d4cabacba 100644
--- a/core/jni/android_graphics_BLASTBufferQueue.cpp
+++ b/core/jni/android_graphics_BLASTBufferQueue.cpp
@@ -52,7 +52,7 @@ static JNIEnv* getenv(JavaVM* vm) {
     return env;
 }
 
-  struct {
+struct {
     jmethodID onTransactionHang;
 } gTransactionHangCallback;
 
@@ -72,12 +72,14 @@ public:
     }
 
     void onTransactionHang(const std::string& reason) {
-        if (mTransactionHangObject) {
-            JNIEnv* env = getenv(mVm);
-            ScopedLocalRef<jstring> jReason(env, env->NewStringUTF(reason.c_str()));
-            getenv(mVm)->CallVoidMethod(mTransactionHangObject,
-                                        gTransactionHangCallback.onTransactionHang, jReason.get());
+        if (!mTransactionHangObject) {
+            return;
         }
+        JNIEnv* env = getenv(mVm);
+        ScopedLocalRef<jstring> jReason(env, env->NewStringUTF(reason.c_str()));
+        getenv(mVm)->CallVoidMethod(mTransactionHangObject,
+                                    gTransactionHangCallback.onTransactionHang, jReason.get());
+        DieIfException(env, "Uncaught exception in TransactionHangCallback.");
     }
 
 private:
diff --git a/core/jni/android_view_SurfaceControl.cpp b/core/jni/android_view_SurfaceControl.cpp
index e42c6f107e6dd..8e96ac1363701 100644
--- a/core/jni/android_view_SurfaceControl.cpp
+++ b/core/jni/android_view_SurfaceControl.cpp
@@ -285,6 +285,7 @@ public:
         JNIEnv* env = getenv();
         env->CallVoidMethod(mTransactionCommittedListenerObject,
                             gTransactionCommittedListenerClassInfo.onTransactionCommitted);
+        DieIfException(env, "Uncaught exception in TransactionCommittedListener.");
     }
 
     static void transactionCallbackThunk(void* context, nsecs_t /*latchTime*/,
@@ -325,6 +326,7 @@ public:
     binder::Status onWindowInfosReported() override {
         JNIEnv* env = getenv();
         env->CallVoidMethod(mListener, gRunnableClassInfo.run);
+        DieIfException(env, "Uncaught exception in WindowInfosReportedListener.");
         return binder::Status::ok();
     }
 
@@ -356,6 +358,7 @@ public:
         env->CallVoidMethod(mTrustedPresentationCallback,
                             gTrustedPresentationCallbackClassInfo.onTrustedPresentationChanged,
                             inTrustedPresentationState);
+        DieIfException(env, "Uncaught exception in TrustedPresentationCallback.");
     }
 
     void addCallbackRef(const sp<SurfaceComposerClient::PresentationCallbackRAII>& callbackRef) {
diff --git a/core/jni/core_jni_helpers.h b/core/jni/core_jni_helpers.h
index b85a42529fb6b..210dc895d674f 100644
--- a/core/jni/core_jni_helpers.h
+++ b/core/jni/core_jni_helpers.h
@@ -134,6 +134,15 @@ static inline JNIEnv* GetOrAttachJNIEnvironment(JavaVM* jvm, jint version = JNI_
     return env;
 }
 
+static inline void DieIfException(JNIEnv* env, const char* message) {
+    if (env->ExceptionCheck()) {
+        jnihelp::ExpandableString summary;
+        jnihelp::ExpandableStringInitialize(&summary);
+        jnihelp::GetStackTraceOrSummary(env, nullptr, &summary);
+        LOG_ALWAYS_FATAL("%s\n%s", message, summary.data);
+    }
+}
+
 }  // namespace android
 
 #endif  // CORE_JNI_HELPERS