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Commit ceed9bb6 authored by Steven Moreland's avatar Steven Moreland
Browse files

libbinder: simplify setIpcSetDataReference 

This deduplicates part of 'freeInit', so that if a reply parcel is
re-used by a client, its previous state may leak into the next step.

Client code essentially look like this:

    Parcel reply;
    ...->transact(..., &reply, ...);
         // inside this call, in waitForResponse
         reply->ipcSetDataReference(...);

However, if multiple transact calls are sent, then other data in Parcel
might be undesirably mutated. Specifically, any field of Parcel which is
currently not set here. However, when receiving a reply from another
process, we want it in a very particular state (and any options on that
Parcel which we want to set on that Parcel should be set by libbinder
itself, if there are every any).

Bug: 167966510
Test: boot & test mapping tests here
Change-Id: Ib834b94c78ac4f481eba280dcec150f53127ce3e
parent adf390d7

libs/binder/Parcel.cpp

+4 −8
Original line number Diff line number Diff line
@@ -2503,19 +2503,15 @@ size_t Parcel::ipcObjectsCount() const 
void Parcel::ipcSetDataReference(const uint8_t* data, size_t dataSize,

    const binder_size_t* objects, size_t objectsCount, release_func relFunc)

{

    binder_size_t minOffset = 0;

    freeDataNoInit();

    mError = NO_ERROR;

    freeData();



    mData = const_cast<uint8_t*>(data);

    mDataSize = mDataCapacity = dataSize;

    //ALOGI("setDataReference Setting data size of %p to %lu (pid=%d)", this, mDataSize, getpid());

    mDataPos = 0;

    ALOGV("setDataReference Setting data pos of %p to %zu", this, mDataPos);

    mObjects = const_cast<binder_size_t*>(objects);

    mObjectsSize = mObjectsCapacity = objectsCount;

    mNextObjectHint = 0;

    mObjectsSorted = false;

    mOwner = relFunc;



    binder_size_t minOffset = 0;

    for (size_t i = 0; i < mObjectsSize; i++) {

        binder_size_t offset = mObjects[i];

        if (offset < minOffset) {