commit 49fdeaff2f4c1405738320b7c3a540b528457e1b
author Praveen Chavan <pchavan@codeaurora.org> Tue Sep 29 02:25:47 2015 -0700
committer Glenn Kasten <gkasten@google.com> Thu Oct 01 16:57:00 2015 -0700
tree 8c4dc9a5d53e6e17bd1fa68f12e4893376eb1f23
parent 921c7dffbd7f594b13688abae363d562eaefa8a0

AudioSystem: Fix race condition in accessing ioDescriptors

The vector mIoDescriptors can be simultaneouly modified
and accessed by 2 threads. Acquire a lock while wrapping
the ioDescriptor in a sp<>

Bug: 24576810

Author: Haynes Mathew George <hgeorge@codeaurora.org>

Change-Id: I73c79ef8eca092b500a7ead3a5ebd0bcf75f9920

media/libmedia/AudioSystem.cpp

diff --git a/media/libmedia/AudioSystem.cpp b/media/libmedia/AudioSystem.cpp
index 3bfb09a..9d645f0 100644
--- a/media/libmedia/AudioSystem.cpp
+++ b/media/libmedia/AudioSystem.cpp
@@ -476,7 +476,7 @@
         switch (event) {
         case AUDIO_OUTPUT_OPENED:
         case AUDIO_INPUT_OPENED: {
-            sp<AudioIoDescriptor> oldDesc = getIoDescriptor(ioDesc->mIoHandle);
+            sp<AudioIoDescriptor> oldDesc = getIoDescriptor_l(ioDesc->mIoHandle);
             if (oldDesc == 0) {
                 mIoDescriptors.add(ioDesc->mIoHandle, ioDesc);
             } else {
@@ -498,7 +498,7 @@
             } break;
         case AUDIO_OUTPUT_CLOSED:
         case AUDIO_INPUT_CLOSED: {
-            if (getIoDescriptor(ioDesc->mIoHandle) == 0) {
+            if (getIoDescriptor_l(ioDesc->mIoHandle) == 0) {
                 ALOGW("ioConfigChanged() closing unknown %s %d",
                       event == AUDIO_OUTPUT_CLOSED ? "output" : "input", ioDesc->mIoHandle);
                 break;
@@ -512,7 +512,7 @@
 
         case AUDIO_OUTPUT_CONFIG_CHANGED:
         case AUDIO_INPUT_CONFIG_CHANGED: {
-            sp<AudioIoDescriptor> oldDesc = getIoDescriptor(ioDesc->mIoHandle);
+            sp<AudioIoDescriptor> oldDesc = getIoDescriptor_l(ioDesc->mIoHandle);
             if (oldDesc == 0) {
                 ALOGW("ioConfigChanged() modifying unknown output! %d", ioDesc->mIoHandle);
                 break;
@@ -575,7 +575,7 @@
     return NO_ERROR;
 }
 
-sp<AudioIoDescriptor> AudioSystem::AudioFlingerClient::getIoDescriptor(audio_io_handle_t ioHandle)
+sp<AudioIoDescriptor> AudioSystem::AudioFlingerClient::getIoDescriptor_l(audio_io_handle_t ioHandle)
 {
     sp<AudioIoDescriptor> desc;
     ssize_t index = mIoDescriptors.indexOfKey(ioHandle);
@@ -585,6 +585,12 @@
     return desc;
 }
 
+sp<AudioIoDescriptor> AudioSystem::AudioFlingerClient::getIoDescriptor(audio_io_handle_t ioHandle)
+{
+    Mutex::Autolock _l(mLock);
+    return getIoDescriptor_l(ioHandle);
+}
+
 status_t AudioSystem::AudioFlingerClient::addAudioDeviceCallback(
         const sp<AudioDeviceCallback>& callback, audio_io_handle_t audioIo)
 {