commit 40343061d5f6f309c68a54940e24d404e6cd620a
author Kevin Rocard <krocard@google.com> Fri Mar 31 19:36:55 2017 -0700
committer Kevin Rocard <krocard@google.com> Fri Apr 07 14:35:47 2017 -0700
tree e8accbddf32406584958b4013081e0de8fb1c459
parent b6498cbdf6c04c631ccf6a6e65a1264b455e3088

Audio HAL: Destroy EventFlag on failed prepareTo{write,read}

If prepareToWrite or prepareToRead fails after EventFlag is created, it
is not destroyed. This lead to strange random crashes (double free it seems).

Use the RAII pattern to manage the EventFlag life cycle.

Test: Run test on target
Bug: 36311550

Change-Id: I53a04a62b7d12fdcc94afd8ced3e547aa6edff50
Signed-off-by: Kevin Rocard <krocard@google.com>

audio/2.0/default/StreamOut.cpp

diff --git a/audio/2.0/default/StreamOut.cpp b/audio/2.0/default/StreamOut.cpp
index 1fe3a69..3339b63 100644
--- a/audio/2.0/default/StreamOut.cpp
+++ b/audio/2.0/default/StreamOut.cpp
@@ -315,8 +315,11 @@
                 CommandMQ::Descriptor(), DataMQ::Descriptor(), StatusMQ::Descriptor(), threadInfo);
         return Void();
     }
-    status = EventFlag::createEventFlag(tempDataMQ->getEventFlagWord(), &mEfGroup);
-    if (status != OK || !mEfGroup) {
+    EventFlag* tempRawEfGroup{};
+    status = EventFlag::createEventFlag(tempDataMQ->getEventFlagWord(), &tempRawEfGroup);
+    std::unique_ptr<EventFlag, void(*)(EventFlag*)> tempElfGroup(tempRawEfGroup,[](auto *ef) {
+            EventFlag::deleteEventFlag(&ef); });
+    if (status != OK || !tempElfGroup) {
         ALOGE("failed creating event flag for data MQ: %s", strerror(-status));
         _hidl_cb(Result::INVALID_ARGUMENTS,
                 CommandMQ::Descriptor(), DataMQ::Descriptor(), StatusMQ::Descriptor(), threadInfo);
@@ -330,7 +333,7 @@
             tempCommandMQ.get(),
             tempDataMQ.get(),
             tempStatusMQ.get(),
-            mEfGroup);
+            tempElfGroup.get());
     if (!tempWriteThread->init()) {
         _hidl_cb(Result::INVALID_ARGUMENTS,
                  CommandMQ::Descriptor(), DataMQ::Descriptor(), StatusMQ::Descriptor(), threadInfo);
@@ -348,6 +351,7 @@
     mDataMQ = std::move(tempDataMQ);
     mStatusMQ = std::move(tempStatusMQ);
     mWriteThread = tempWriteThread.release();
+    mEfGroup = tempElfGroup.release();
     threadInfo.pid = getpid();
     threadInfo.tid = mWriteThread->getTid();
     _hidl_cb(Result::OK,