Merge "libbinder: Handle peer closing connection in Trusty" am: a1cf02cf50 am: c0e7936dd0

Original change: https://android-review.googlesource.com/c/platform/frameworks/native/+/2336530

Change-Id: I313f60528415b1e98d841286c52519fbb4121722
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

2 files changed, 11 insertions, 3 deletions

diff --git a/libs/binder/RpcTransportTipcAndroid.cpp b/libs/binder/RpcTransportTipcAndroid.cpp
index 453279c0a5..8b3ddfbd6f 100644
--- a/libs/binder/RpcTransportTipcAndroid.cpp
+++ b/libs/binder/RpcTransportTipcAndroid.cpp
@@ -63,12 +63,14 @@ public:
         if (pfd.revents & POLLERR) {
             return DEAD_OBJECT;
         }
-        if (pfd.revents & POLLHUP) {
-            return DEAD_OBJECT;
-        }
         if (pfd.revents & POLLIN) {
+            // Copied from FdTrigger.cpp: Even though POLLHUP may also be set,
+            // treat it as a success condition to ensure data is drained.
             return OK;
         }
+        if (pfd.revents & POLLHUP) {
+            return DEAD_OBJECT;
+        }
 
         return WOULD_BLOCK;
     }
diff --git a/libs/binder/trusty/RpcTransportTipcTrusty.cpp b/libs/binder/trusty/RpcTransportTipcTrusty.cpp
index 58bfe71211..d249b2e1eb 100644
--- a/libs/binder/trusty/RpcTransportTipcTrusty.cpp
+++ b/libs/binder/trusty/RpcTransportTipcTrusty.cpp
@@ -239,6 +239,12 @@ private:
         }
         if (!(uevt.event & IPC_HANDLE_POLL_MSG)) {
             /* No message, terminate here and leave mHaveMessage false */
+            if (uevt.event & IPC_HANDLE_POLL_HUP) {
+                // Peer closed the connection. We need to preserve the order
+                // between MSG and HUP from FdTrigger.cpp, which means that
+                // getting MSG&HUP should return OK instead of DEAD_OBJECT.
+                return DEAD_OBJECT;
+            }
             return OK;
         }