libbinder: do not always compute open ashmem size (c673f1f0) · Commits · e / os / android_frameworks_native-old

libs/binder/Parcel.cpp

+27 −32

Original line number	Diff line number	Diff line
		@@ -98,9 +98,8 @@ enum {
		BLOB_ASHMEM_MUTABLE = 2,
		};

		static void acquire_object(const sp<ProcessState>& proc,
		const flat_binder_object& obj, const void* who, size_t* outAshmemSize)
		{
		static void acquire_object(const sp<ProcessState>& proc, const flat_binder_object& obj,
		const void* who) {
		switch (obj.hdr.type) {
		case BINDER_TYPE_BINDER:
		if (obj.binder) {
		@@ -117,13 +116,6 @@ static void acquire_object(const sp<ProcessState>& proc,
		return;
		}
		case BINDER_TYPE_FD: {
		if ((obj.cookie != 0) && (outAshmemSize != nullptr) && ashmem_valid(obj.handle)) {
		// If we own an ashmem fd, keep track of how much memory it refers to.
		int size = ashmem_get_size_region(obj.handle);
		if (size > 0) {
		*outAshmemSize += size;
		}
		}
		return;
		}
		}
		@@ -131,9 +123,8 @@ static void acquire_object(const sp<ProcessState>& proc,
		ALOGD("Invalid object type 0x%08x", obj.hdr.type);
		}

		static void release_object(const sp<ProcessState>& proc,
		const flat_binder_object& obj, const void* who, size_t* outAshmemSize)
		{
		static void release_object(const sp<ProcessState>& proc, const flat_binder_object& obj,
		const void* who) {
		switch (obj.hdr.type) {
		case BINDER_TYPE_BINDER:
		if (obj.binder) {
		@@ -151,16 +142,6 @@ static void release_object(const sp<ProcessState>& proc,
		}
		case BINDER_TYPE_FD: {
		if (obj.cookie != 0) { // owned
		if ((outAshmemSize != nullptr) && ashmem_valid(obj.handle)) {
		int size = ashmem_get_size_region(obj.handle);
		if (size > 0) {
		// ashmem size might have changed since last time it was accounted for, e.g.
		// in acquire_object(). Value of *outAshmemSize is not critical since we are
		// releasing the object anyway. Check for integer overflow condition.
		outAshmemSize -= std::min(outAshmemSize, static_cast<size_t>(size));
		}
		}

		close(obj.handle);
		}
		return;
		@@ -512,7 +493,7 @@ status_t Parcel::appendFrom(const Parcel *parcel, size_t offset, size_t len)

		flat_binder_object* flat
		= reinterpret_cast<flat_binder_object*>(mData + off);
		acquire_object(proc, *flat, this, &mOpenAshmemSize);
		acquire_object(proc, *flat, this);

		if (flat->hdr.type == BINDER_TYPE_FD) {
		// If this is a file descriptor, we need to dup it so the
		@@ -1335,7 +1316,7 @@ restart_write:
		// Need to write meta-data?
		if (nullMetaData \|\| val.binder != 0) {
		mObjects[mObjectsSize] = mDataPos;
		acquire_object(ProcessState::self(), val, this, &mOpenAshmemSize);
		acquire_object(ProcessState::self(), val, this);
		mObjectsSize++;
		}

		@@ -2225,7 +2206,7 @@ void Parcel::releaseObjects()
		i--;
		const flat_binder_object* flat
		= reinterpret_cast<flat_binder_object*>(data+objects[i]);
		release_object(proc, *flat, this, &mOpenAshmemSize);
		release_object(proc, *flat, this);
		}
		}

		@@ -2242,7 +2223,7 @@ void Parcel::acquireObjects()
		i--;
		const flat_binder_object* flat
		= reinterpret_cast<flat_binder_object*>(data+objects[i]);
		acquire_object(proc, *flat, this, &mOpenAshmemSize);
		acquire_object(proc, *flat, this);
		}
		}

		@@ -2447,7 +2428,7 @@ status_t Parcel::continueWrite(size_t desired)
		// will need to rescan because we may have lopped off the only FDs
		mFdsKnown = false;
		}
		release_object(proc, *flat, this, &mOpenAshmemSize);
		release_object(proc, *flat, this);
		}

		if (objectsSize == 0) {
		@@ -2540,7 +2521,6 @@ void Parcel::initState()
		mAllowFds = true;
		mDeallocZero = false;
		mOwner = nullptr;
		mOpenAshmemSize = 0;
		mWorkSourceRequestHeaderPosition = 0;
		mRequestHeaderPresent = false;

		@@ -2576,13 +2556,28 @@ size_t Parcel::getBlobAshmemSize() const
		{
		// This used to return the size of all blobs that were written to ashmem, now we're returning
		// the ashmem currently referenced by this Parcel, which should be equivalent.
		// TODO: Remove method once ABI can be changed.
		return mOpenAshmemSize;
		// TODO(b/202029388): Remove method once ABI can be changed.
		return getOpenAshmemSize();
		}

		size_t Parcel::getOpenAshmemSize() const
		{
		return mOpenAshmemSize;
		size_t openAshmemSize = 0;
		for (size_t i = 0; i < mObjectsSize; i++) {
		const flat_binder_object* flat =
		reinterpret_cast<const flat_binder_object*>(mData + mObjects[i]);

		// cookie is compared against zero for historical reasons
		// > obj.cookie = takeOwnership ? 1 : 0;
		if (flat->hdr.type == BINDER_TYPE_FD && flat->cookie != 0 && ashmem_valid(flat->handle)) {
		int size = ashmem_get_size_region(flat->handle);
		if (__builtin_add_overflow(openAshmemSize, size, &openAshmemSize)) {
		ALOGE("Overflow when computing ashmem size.");
		return SIZE_MAX;
		}
		}
		}
		return openAshmemSize;
		}

		// --- Parcel::Blob ---

libs/binder/include/binder/Parcel.h

+10 −5

Original line number	Diff line number	Diff line
		@@ -1141,6 +1141,7 @@ private:
		release_func mOwner;

		sp<RpcSession> mSession;
		size_t mReserved;

		class Blob {
		public:
		@@ -1225,13 +1226,17 @@ public:
		inline void* data() { return mData; }
		};

		private:
		size_t mOpenAshmemSize;
		/**
		* Returns the total amount of ashmem memory owned by this object.
		*
		* Note: for historical reasons, this does not include ashmem memory which
		* is referenced by this Parcel, but which this parcel doesn't own (e.g.
		* writeFileDescriptor is called without 'takeOwnership' true).
		*/
		size_t getOpenAshmemSize() const;

		public:
		// TODO: Remove once ABI can be changed.
		// TODO(b/202029388): Remove 'getBlobAshmemSize' once ABI can be changed.
		size_t getBlobAshmemSize() const;
		size_t getOpenAshmemSize() const;
		};

		// ---------------------------------------------------------------------------