From 3796b0d6a647022ee4c2a9458392d922411c8b53 Mon Sep 17 00:00:00 2001
From: Martijn Coenen <maco@google.com>
Date: Thu, 9 Aug 2018 16:11:04 +0200
Subject: [PATCH] BinderProxy dump: distinguish between empty descriptor and
 dead remote.

getInterfaceDescriptor() will return an empty string when the call
to retrieve it into the remote process fails. Proxies to a dead binder
process then show up as having an empty descriptor in the proxy dumps,
and can't be distinguished from live proxies with an empty descriptor.

Instead, if we get an empty string, check if the proxy is still alive,
so we can more accurately dump. This will make it much easier to find
proxy leaks to dead binder nodes.

Bug: 109888955
Test: adb shell dumpsys activity binder-proxies
Change-Id: Ib37ec004f38c99743ffb4a62101c12626b649e5d
---
 core/java/android/os/BinderProxy.java | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/core/java/android/os/BinderProxy.java b/core/java/android/os/BinderProxy.java
index dc09c51f934fb..e492f88d4329a 100644
--- a/core/java/android/os/BinderProxy.java
+++ b/core/java/android/os/BinderProxy.java
@@ -240,6 +240,9 @@ public final class BinderProxy implements IBinder {
                         } else {
                             try {
                                 key = bp.getInterfaceDescriptor();
+                                if ((key == null || key.isEmpty()) && !bp.isBinderAlive()) {
+                                    key = "<proxy to dead node>";
+                                }
                             } catch (Throwable t) {
                                 key = "<exception during getDescriptor>";
                             }