commit 4cf688f166b7952195c45da680aa75975acd84c0
author Steven Moreland <smoreland@google.com> Wed Mar 31 01:48:58 2021 +0000
committer Steven Moreland <smoreland@google.com> Fri Apr 02 01:48:56 2021 +0000
tree 050996524292046c1c5f85c5988536444b56be33
parent 8911d46baf682d95a08efd678aaee7fc15c9767a

libbinder: RPC with getInterfaceDescriptor

I need to follow up/add tests for all the built-in transactions, since
they need to call markForBinder, but this is required for making RPC
calls over NDK because this backend proactively retrieves the interface
descriptor (side note: potential optimization improvement).

Bug: 167966510
Test: binderRpcTest
Change-Id: I62ec7bf09040563d46aa43a685efb87e3add524f

libs/binder/BpBinder.cpp

diff --git a/libs/binder/BpBinder.cpp b/libs/binder/BpBinder.cpp
index 825a821..53b36ff 100644
--- a/libs/binder/BpBinder.cpp
+++ b/libs/binder/BpBinder.cpp
@@ -194,10 +194,13 @@
 const String16& BpBinder::getInterfaceDescriptor() const
 {
     if (isDescriptorCached() == false) {
-        Parcel send, reply;
+        sp<BpBinder> thiz = const_cast<BpBinder*>(this);
+
+        Parcel data;
+        data.markForBinder(thiz);
+        Parcel reply;
         // do the IPC without a lock held.
-        status_t err = const_cast<BpBinder*>(this)->transact(
-                INTERFACE_TRANSACTION, send, &reply);
+        status_t err = thiz->transact(INTERFACE_TRANSACTION, data, &reply);
         if (err == NO_ERROR) {
             String16 res(reply.readString16());
             Mutex::Autolock _l(mLock);