commit a3129fbfc3f4f31e1760442b786adcbfdea37578
author Ady Abraham <adyabr@google.com> Fri Oct 18 14:17:23 2019 -0700
committer Ady Abraham <adyabr@google.com> Fri Oct 18 21:19:27 2019 +0000
tree 3575320c1b25d80165704a0d2a6da536b0b5e8a3
parent 7b54102e954151bbbc16cec01a922d811fc209aa

SurfaceFlinger: lock mStateLock when modifying allowed configs

mAllowedDisplayConfigs should be protected by mStateLock when changing
it from the main thread in setAllowedDisplayConfigsInternal() as it is
being read by Binder threads in getAllowedDisplayConfigs().

Test: call setAllowedDisplayConfigs() and getAllowedDisplayConfigs()
      from backdoor using different threads.
Bug: 142850581

Change-Id: I569e75968aea676c96fbc648140ac49a165ffb69

services/surfaceflinger/SurfaceFlinger.cpp

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 0e33f10..ef9a598 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -5452,7 +5452,7 @@
         return NO_ERROR;
     }
 
-    postMessageSync(new LambdaMessage([&]() NO_THREAD_SAFETY_ANALYSIS {
+    postMessageSync(new LambdaMessage([&]() {
         const auto display = getDisplayDeviceLocked(displayToken);
         if (!display) {
             ALOGE("Attempt to set allowed display configs for invalid display token %p",
@@ -5460,6 +5460,7 @@
         } else if (display->isVirtual()) {
             ALOGW("Attempt to set allowed display configs for virtual display");
         } else {
+            Mutex::Autolock lock(mStateLock);
             setAllowedDisplayConfigsInternal(display, allowedConfigs);
         }
     }));