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Commit b95831cb authored by Steven Moreland's avatar Steven Moreland
Browse files

Binder: don't call getCallingUid for RPC calls 

All the code using getCallingUid here should be
ripped out anyway because it's Java-centric. Here
are some of the issues with the current stuff around
here:
- it's broken because it won't handle things happening in
  native code
- it's slow (e.g. big transactions are already logged in
  native code anyway)

Bug: 254835230
Test: boots, atest MicrodroidTestApp (with new tests)
Change-Id: I7315059bff138966e9509f1d529a6417466d2b7f
parent b6663f9d

core/java/android/os/Binder.java

+29 −11
Original line number Diff line number Diff line
@@ -1219,25 +1219,40 @@ public class Binder implements IBinder { 
    @UnsupportedAppUsage

    private boolean execTransact(int code, long dataObj, long replyObj,

            int flags) {



        Parcel data = Parcel.obtain(dataObj);

        Parcel reply = Parcel.obtain(replyObj);



        // At that point, the parcel request headers haven't been parsed so we do not know what

        // {@link WorkSource} the caller has set. Use calling UID as the default.

        final int callingUid = Binder.getCallingUid();

        final long origWorkSource = ThreadLocalWorkSource.setUid(callingUid);

        //

        // TODO: this is wrong - we should attribute along the entire call route

        // also this attribution logic should move to native code - it only works

        // for Java now

        //

        // This attribution support is not generic and therefore not support in RPC mode

        final int callingUid = data.isForRpc() ? -1 : Binder.getCallingUid();

        final long origWorkSource = callingUid == -1

                ? -1 : ThreadLocalWorkSource.setUid(callingUid);



        try {

            return execTransactInternal(code, dataObj, replyObj, flags, callingUid);

            return execTransactInternal(code, data, reply, flags, callingUid);

        } finally {

            reply.recycle();

            data.recycle();



            if (callingUid != -1) {

                ThreadLocalWorkSource.restore(origWorkSource);

            }

        }

    }



    private boolean execTransactInternal(int code, long dataObj, long replyObj, int flags,

    private boolean execTransactInternal(int code, Parcel data, Parcel reply, int flags,

            int callingUid) {

        // Make sure the observer won't change while processing a transaction.

        final BinderInternal.Observer observer = sObserver;

        final CallSession callSession =

                observer != null ? observer.callStarted(this, code, UNSET_WORKSOURCE) : null;

        Parcel data = Parcel.obtain(dataObj);

        Parcel reply = Parcel.obtain(replyObj);

        // Theoretically, we should call transact, which will call onTransact,

        // but all that does is rewind it, and we just got these from an IPC,

        // so we'll just call it directly.
@@ -1268,8 +1283,10 @@ public class Binder implements IBinder { 


        final boolean tracingEnabled = tagEnabled && transactionTraceName != null;

        try {

            // TODO - this logic should not be in Java - it should be in native

            // code in libbinder so that it works for all binder users.

            final BinderCallHeavyHitterWatcher heavyHitterWatcher = sHeavyHitterWatcher;

            if (heavyHitterWatcher != null) {

            if (heavyHitterWatcher != null && callingUid != -1) {

                // Notify the heavy hitter watcher, if it's enabled.

                heavyHitterWatcher.onTransaction(callingUid, getClass(), code);

            }
@@ -1277,7 +1294,10 @@ public class Binder implements IBinder { 
                Trace.traceBegin(Trace.TRACE_TAG_AIDL, transactionTraceName);

            }



            if ((flags & FLAG_COLLECT_NOTED_APP_OPS) != 0) {

            // TODO - this logic should not be in Java - it should be in native

            // code in libbinder so that it works for all binder users. Further,

            // this should not re-use flags.

            if ((flags & FLAG_COLLECT_NOTED_APP_OPS) != 0 && callingUid != -1) {

                AppOpsManager.startNotedAppOpsCollection(callingUid);

                try {

                    res = onTransact(code, data, reply, flags);
@@ -1320,8 +1340,6 @@ public class Binder implements IBinder { 
            }



            checkParcel(this, code, reply, "Unreasonably large binder reply buffer");

            reply.recycle();

            data.recycle();

        }



        // Just in case -- we are done with the IPC, so there should be no more strict