+status_t Parcel::validateReadData(size_t upperBound) const
+{
+ // Don't allow non-object reads on object data
+ if (mObjectsSorted || mObjectsSize <= 1) {
+data_sorted:
+ // Expect to check only against the next object
+ if (mNextObjectHint < mObjectsSize && upperBound > mObjects[mNextObjectHint]) {
+ // For some reason the current read position is greater than the next object
+ // hint. Iterate until we find the right object
+ size_t nextObject = mNextObjectHint;
+ do {
+ if (mDataPos < mObjects[nextObject] + sizeof(flat_binder_object)) {
+ // Requested info overlaps with an object
+ ALOGE("Attempt to read from protected data in Parcel %p", this);
+ return PERMISSION_DENIED;
+ }
+ nextObject++;
+ } while (nextObject < mObjectsSize && upperBound > mObjects[nextObject]);
+ mNextObjectHint = nextObject;
+ }
+ return NO_ERROR;
+ }
+ // Quickly determine if mObjects is sorted.
+ binder_size_t* currObj = mObjects + mObjectsSize - 1;
+ binder_size_t* prevObj = currObj;
+ while (currObj > mObjects) {
+ prevObj--;
+ if(*prevObj > *currObj) {
+ goto data_unsorted;
+ }
+ currObj--;
+ }
+ mObjectsSorted = true;
+ goto data_sorted;
+
+data_unsorted:
+ // Insertion Sort mObjects
+ // Great for mostly sorted lists. If randomly sorted or reverse ordered mObjects become common,
+ // switch to std::sort(mObjects, mObjects + mObjectsSize);
+ for (binder_size_t* iter0 = mObjects + 1; iter0 < mObjects + mObjectsSize; iter0++) {
+ binder_size_t temp = *iter0;
+ binder_size_t* iter1 = iter0 - 1;
+ while (iter1 >= mObjects && *iter1 > temp) {
+ *(iter1 + 1) = *iter1;
+ iter1--;
+ }
+ *(iter1 + 1) = temp;
+ }
+ mNextObjectHint = 0;
+ mObjectsSorted = true;
+ goto data_sorted;
+}
+