BufferQueueProducer: use the correct IPCThreadState.

The system variant of libgui maybe be double loaded. Also
IGraphicBufferProducer functions may be called from hwbinder threads due
to the presence of TWGraphicBufferProducer wrappers (hybrid interfaces).
Therefore, we should use the correct IPCThreadState/ hardware::IPCThreadState to query
callingPids. This also avoids access to /dev/binder in vendor processes,
in case the system variant of the library is loaded, for eg: in
libmediandk.

Bug: 124128212

Test: Selinux denials realted to/dev/binder acccess are not present when AImageReader from
      libmediandk is used in a vendor process.

Test: Play Youtube movies on Chrome, use camera to take pictures/ record
      videos (sanity).

Change-Id: I27d78e30e16b7df5e3dfbb130121f3d7078671a3
Signed-off-by: Jayant Chowdhary <jchowdhary@google.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/libs/gui/include/private/gui/BufferQueueThreadState.h b/libs/gui/include/private/gui/BufferQueueThreadState.h
new file mode 100644
index 000000000..67dcf621c
--- /dev/null
+++ b/libs/gui/include/private/gui/BufferQueueThreadState.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdint.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+namespace android {
+
+// TODO: Replace this with b/127962003
+class BufferQueueThreadState {
+public:
+    static pid_t getCallingPid();
+    static uid_t getCallingUid();
+};
+
+} // namespace android