display: Fix binder parcel position

If we call binder APIs from within the same process, the parcels
read position will not be reset at the client end. Also there is
no interface token. Reset the parcel position to zero if the
calling process is the same as the current one.

Change-Id: I6c4499f453dba3ec89b203ce9c86150edaefdbec

1 files changed, 6 insertions, 0 deletions

diff --git a/libqservice/QService.cpp b/libqservice/QService.cpp
index e4af42232..12dd9956a 100644
--- a/libqservice/QService.cpp
+++ b/libqservice/QService.cpp
@@ -28,6 +28,8 @@
  */
 
 #include <QService.h>
+#include <binder/Parcel.h>
+#include <binder/IPCThreadState.h>
 
 #define QSERVICE_DEBUG 0
 
@@ -55,6 +57,10 @@ void QService::connect(const sp<qClient::IQClient>& client) {
 status_t QService::dispatch(uint32_t command, const Parcel* inParcel,
         Parcel* outParcel) {
     status_t err = (status_t) FAILED_TRANSACTION;
+    IPCThreadState* ipc = IPCThreadState::self();
+    //Rewind parcel in case we're calling from the same process
+    if (ipc->getCallingPid() == getpid())
+        inParcel->setDataPosition(0);
     if (mClient.get()) {
         ALOGD_IF(QSERVICE_DEBUG, "Dispatching command: %d", command);
         err = mClient->notifyCallback(command, inParcel, outParcel);