commit 9f50ea66b4cd4ddf436fea574f768a7fab7963ea
author Steven Moreland <smoreland@google.com> Fri Sep 18 01:04:15 2020 +0000
committer Steven Moreland <smoreland@google.com> Fri Sep 18 01:09:35 2020 +0000
tree 6c8055488eaca1bd3543f2d3a5a9a7ec6fcff942
parent 6ba4920c3ac53336b7a6c5f25abeb50bbd9d0f93

libbinder: ignore CallRestriction for magic 0 cmd

There is a special transaction required to make sure that the context
manager is setup before we get a reference to it. Since this is required
to use binder, it would prevent use of CallRestriction outside of
servicemanager.

Fixes: 167302413
Test: binderLibTest

Change-Id: I029e2a99013008a7c8614d63dc29df2889067d11

libs/binder/IPCThreadState.cpp

diff --git a/libs/binder/IPCThreadState.cpp b/libs/binder/IPCThreadState.cpp
index 0c71ed8..33e7d47 100644
--- a/libs/binder/IPCThreadState.cpp
+++ b/libs/binder/IPCThreadState.cpp
@@ -448,6 +448,14 @@
     return mLastTransactionBinderFlags;
 }
 
+void IPCThreadState::setCallRestriction(ProcessState::CallRestriction restriction) {
+    mCallRestriction = restriction;
+}
+
+ProcessState::CallRestriction IPCThreadState::getCallRestriction() const {
+    return mCallRestriction;
+}
+
 void IPCThreadState::restoreCallingIdentity(int64_t token)
 {
     mCallingUid = (int)(token>>32);

libs/binder/ProcessState.cpp

diff --git a/libs/binder/ProcessState.cpp b/libs/binder/ProcessState.cpp
index a530565..83ca687 100644
--- a/libs/binder/ProcessState.cpp
+++ b/libs/binder/ProcessState.cpp
@@ -282,9 +282,17 @@
                 // a driver API to get a handle to the context manager with
                 // proper reference counting.
 
+                IPCThreadState* ipc = IPCThreadState::self();
+
+                CallRestriction originalCallRestriction = ipc->getCallRestriction();
+                ipc->setCallRestriction(CallRestriction::NONE);
+
                 Parcel data;
-                status_t status = IPCThreadState::self()->transact(
+                status_t status = ipc->transact(
                         0, IBinder::PING_TRANSACTION, data, nullptr, 0);
+
+                ipc->setCallRestriction(originalCallRestriction);
+
                 if (status == DEAD_OBJECT)
                    return nullptr;
             }

libs/binder/include/binder/IPCThreadState.h

diff --git a/libs/binder/include/binder/IPCThreadState.h b/libs/binder/include/binder/IPCThreadState.h
index cdeccea..867d307 100644
--- a/libs/binder/include/binder/IPCThreadState.h
+++ b/libs/binder/include/binder/IPCThreadState.h
@@ -32,6 +32,8 @@
 class IPCThreadState
 {
 public:
+    using CallRestriction = ProcessState::CallRestriction;
+
     static  IPCThreadState*     self();
     static  IPCThreadState*     selfOrNull();  // self(), but won't instantiate
 
@@ -96,6 +98,9 @@
             void                setLastTransactionBinderFlags(int32_t flags);
             int32_t             getLastTransactionBinderFlags() const;
 
+            void                setCallRestriction(CallRestriction restriction);
+            CallRestriction     getCallRestriction() const;
+
             int64_t             clearCallingIdentity();
             // Restores PID/UID (not SID)
             void                restoreCallingIdentity(int64_t token);
@@ -154,7 +159,6 @@
             // This constant needs to be kept in sync with Binder.UNSET_WORKSOURCE from the Java
             // side.
             static const int32_t kUnsetWorkSource = -1;
-
 private:
                                 IPCThreadState();
                                 ~IPCThreadState();
@@ -201,8 +205,7 @@
             bool                mPropagateWorkSource;
             int32_t             mStrictModePolicy;
             int32_t             mLastTransactionBinderFlags;
-
-            ProcessState::CallRestriction mCallRestriction;
+            CallRestriction     mCallRestriction;
 };
 
 } // namespace android

libs/binder/tests/binderLibTest.cpp

diff --git a/libs/binder/tests/binderLibTest.cpp b/libs/binder/tests/binderLibTest.cpp
index 145c099..c9cd102 100644
--- a/libs/binder/tests/binderLibTest.cpp
+++ b/libs/binder/tests/binderLibTest.cpp
@@ -599,6 +599,12 @@
     ASSERT_TRUE(server != nullptr);
 }
 
+TEST_F(BinderLibTest, AddManagerToManager) {
+    sp<IServiceManager> sm = defaultServiceManager();
+    sp<IBinder> binder = IInterface::asBinder(sm);
+    EXPECT_EQ(NO_ERROR, sm->addService(String16("binderLibTest-manager"), binder));
+}
+
 TEST_F(BinderLibTest, DeathNotificationStrongRef)
 {
     status_t ret;