Merge changes Ieb537412,I2339a8e0 am: a7e51752c2 (5ada8b38) · Commits · e / os / platform_frameworks_native

libs/binder/Parcel.cpp

+3 −0

Original line number	Diff line number	Diff line
		@@ -291,6 +291,9 @@ status_t Parcel::unflattenBinder(sp<IBinder>* out) const
		if (status_t status = mSession->state()->onBinderEntering(mSession, addr, &binder);
		status != OK)
		return status;
		if (status_t status = mSession->state()->flushExcessBinderRefs(mSession, addr, binder);
		status != OK)
		return status;
		}

		return finishUnflattenBinder(binder, out);

libs/binder/RpcSession.cpp

+5 −3

Original line number	Diff line number	Diff line
		@@ -217,15 +217,17 @@ status_t RpcSession::transact(const sp<IBinder>& binder, uint32_t code, const Pa
		}

		status_t RpcSession::sendDecStrong(const BpBinder* binder) {
		return sendDecStrong(binder->getPrivateAccessor().rpcAddress());
		// target is 0 because this is used to free BpBinder objects
		return sendDecStrongToTarget(binder->getPrivateAccessor().rpcAddress(), 0 /target/);
		}

		status_t RpcSession::sendDecStrong(uint64_t address) {
		status_t RpcSession::sendDecStrongToTarget(uint64_t address, size_t target) {
		ExclusiveConnection connection;
		status_t status = ExclusiveConnection::find(sp<RpcSession>::fromExisting(this),
		ConnectionUse::CLIENT_REFCOUNT, &connection);
		if (status != OK) return status;
		return state()->sendDecStrong(connection.get(), sp<RpcSession>::fromExisting(this), address);
		return state()->sendDecStrongToTarget(connection.get(), sp<RpcSession>::fromExisting(this),
		address, target);
		}

		status_t RpcSession::readId() {

libs/binder/RpcState.cpp

+77 −26

Original line number	Diff line number	Diff line
		@@ -152,7 +152,7 @@ status_t RpcState::onBinderEntering(const sp<RpcSession>& session, uint64_t addr
		return BAD_VALUE;
		}

		std::unique_lock<std::mutex> _l(mNodeMutex);
		std::lock_guard<std::mutex> _l(mNodeMutex);
		if (mTerminated) return DEAD_OBJECT;

		if (auto it = mNodeForAddress.find(address); it != mNodeForAddress.end()) {
		@@ -160,13 +160,7 @@ status_t RpcState::onBinderEntering(const sp<RpcSession>& session, uint64_t addr

		// implicitly have strong RPC refcount, since we received this binder
		it->second.timesRecd++;

		_l.unlock();

		// We have timesRecd RPC refcounts, but we only need to hold on to one
		// when we keep the object. All additional dec strongs are sent
		// immediately, we wait to send the last one in BpBinder::onLastDecStrong.
		return session->sendDecStrong(address);
		return OK;
		}

		// we don't know about this binder, so the other side of the connection
		@@ -187,6 +181,36 @@ status_t RpcState::onBinderEntering(const sp<RpcSession>& session, uint64_t addr
		return OK;
		}

		status_t RpcState::flushExcessBinderRefs(const sp<RpcSession>& session, uint64_t address,
		const sp<IBinder>& binder) {
		std::unique_lock<std::mutex> _l(mNodeMutex);
		if (mTerminated) return DEAD_OBJECT;

		auto it = mNodeForAddress.find(address);

		LOG_ALWAYS_FATAL_IF(it == mNodeForAddress.end(), "Can't be deleted while we hold sp<>");
		LOG_ALWAYS_FATAL_IF(it->second.binder != binder,
		"Caller of flushExcessBinderRefs using inconsistent arguments");

		// if this is a local binder, then we want to get rid of all refcounts
		// (tell the other process it can drop the binder when it wants to - we
		// have a local sp<>, so we will drop it when we want to as well). if
		// this is a remote binder, then we need to hold onto one refcount until
		// it is dropped in BpBinder::onLastStrongRef
		size_t targetRecd = binder->localBinder() ? 0 : 1;

		// We have timesRecd RPC refcounts, but we only need to hold on to one
		// when we keep the object. All additional dec strongs are sent
		// immediately, we wait to send the last one in BpBinder::onLastDecStrong.
		if (it->second.timesRecd != targetRecd) {
		_l.unlock();

		return session->sendDecStrongToTarget(address, targetRecd);
		}

		return OK;
		}

		size_t RpcState::countBinders() {
		std::lock_guard<std::mutex> _l(mNodeMutex);
		return mNodeForAddress.size();
		@@ -571,32 +595,43 @@ status_t RpcState::waitForReply(const sp<RpcSession::RpcConnection>& connection,
		return OK;
		}

		status_t RpcState::sendDecStrong(const sp<RpcSession::RpcConnection>& connection,
		const sp<RpcSession>& session, uint64_t addr) {
		status_t RpcState::sendDecStrongToTarget(const sp<RpcSession::RpcConnection>& connection,
		const sp<RpcSession>& session, uint64_t addr,
		size_t target) {
		RpcDecStrong body = {
		.address = RpcWireAddress::fromRaw(addr),
		};

		{
		std::lock_guard<std::mutex> _l(mNodeMutex);
		if (mTerminated) return DEAD_OBJECT; // avoid fatal only, otherwise races
		auto it = mNodeForAddress.find(addr);
		LOG_ALWAYS_FATAL_IF(it == mNodeForAddress.end(),
		"Sending dec strong on unknown address %" PRIu64, addr);
		LOG_ALWAYS_FATAL_IF(it->second.timesRecd <= 0, "Bad dec strong %" PRIu64, addr);

		it->second.timesRecd--;
		LOG_ALWAYS_FATAL_IF(it->second.timesRecd < target, "Can't dec count of %zu to %zu.",
		it->second.timesRecd, target);

		// typically this happens when multiple threads send dec refs at the
		// same time - the transactions will get combined automatically
		if (it->second.timesRecd == target) return OK;

		body.amount = it->second.timesRecd - target;
		it->second.timesRecd = target;

		LOG_ALWAYS_FATAL_IF(nullptr != tryEraseNode(it),
		"Bad state. RpcState shouldn't own received binder");
		}

		RpcWireHeader cmd = {
		.command = RPC_COMMAND_DEC_STRONG,
		.bodySize = sizeof(RpcWireAddress),
		.bodySize = sizeof(RpcDecStrong),
		};
		if (status_t status = rpcSend(connection, session, "dec ref header", &cmd, sizeof(cmd));
		status != OK)
		return status;
		if (status_t status = rpcSend(connection, session, "dec ref body", &addr, sizeof(addr));
		status != OK)
		return status;
		return OK;

		return rpcSend(connection, session, "dec ref body", &body, sizeof(body));
		}

		status_t RpcState::getAndExecuteCommand(const sp<RpcSession::RpcConnection>& connection,
		@@ -827,6 +862,12 @@ processTransactInternalTailCall:
		}
		}

		// Binder refs are flushed for oneway calls only after all calls which are
		// built up are executed. Otherwise, they fill up the binder buffer.
		if (addr != 0 && replyStatus == OK && !oneway) {
		replyStatus = flushExcessBinderRefs(session, addr, target);
		}

		if (oneway) {
		if (replyStatus != OK) {
		ALOGW("Oneway call failed with error: %d", replyStatus);
		@@ -875,6 +916,13 @@ processTransactInternalTailCall:
		goto processTransactInternalTailCall;
		}
		}

		// done processing all the async commands on this binder that we can, so
		// write decstrongs on the binder
		if (addr != 0 && replyStatus == OK) {
		return flushExcessBinderRefs(session, addr, target);
		}

		return OK;
		}

		@@ -916,16 +964,15 @@ status_t RpcState::processDecStrong(const sp<RpcSession::RpcConnection>& connect
		status != OK)
		return status;

		if (command.bodySize != sizeof(RpcWireAddress)) {
		ALOGE("Expecting %zu but got %" PRId32 " bytes for RpcWireAddress. Terminating!",
		sizeof(RpcWireAddress), command.bodySize);
		if (command.bodySize != sizeof(RpcDecStrong)) {
		ALOGE("Expecting %zu but got %" PRId32 " bytes for RpcDecStrong. Terminating!",
		sizeof(RpcDecStrong), command.bodySize);
		(void)session->shutdownAndWait(false);
		return BAD_VALUE;
		}
		RpcWireAddress* address = reinterpret_cast<RpcWireAddress*>(commandData.data());

		uint64_t addr = RpcWireAddress::toRaw(*address);
		RpcDecStrong* body = reinterpret_cast<RpcDecStrong*>(commandData.data());

		uint64_t addr = RpcWireAddress::toRaw(body->address);
		std::unique_lock<std::mutex> _l(mNodeMutex);
		auto it = mNodeForAddress.find(addr);
		if (it == mNodeForAddress.end()) {
		@@ -943,15 +990,19 @@ status_t RpcState::processDecStrong(const sp<RpcSession::RpcConnection>& connect
		return BAD_VALUE;
		}

		if (it->second.timesSent == 0) {
		ALOGE("No record of sending binder, but requested decStrong: %" PRIu64, addr);
		if (it->second.timesSent < body->amount) {
		ALOGE("Record of sending binder %zu times, but requested decStrong for %" PRIu64 " of %u",
		it->second.timesSent, addr, body->amount);
		return OK;
		}

		LOG_ALWAYS_FATAL_IF(it->second.sentRef == nullptr, "Inconsistent state, lost ref for %" PRIu64,
		addr);

		it->second.timesSent--;
		LOG_RPC_DETAIL("Processing dec strong of %" PRIu64 " by %u from %zu", addr, body->amount,
		it->second.timesSent);

		it->second.timesSent -= body->amount;
		sp<IBinder> tempHold = tryEraseNode(it);
		_l.unlock();
		tempHold = nullptr; // destructor may make binder calls on this session

libs/binder/RpcState.h

+30 −2

Original line number	Diff line number	Diff line
		@@ -82,8 +82,29 @@ public:
		uint64_t address, uint32_t code, const Parcel& data,
		const sp<RpcSession>& session, Parcel* reply,
		uint32_t flags);
		[[nodiscard]] status_t sendDecStrong(const sp<RpcSession::RpcConnection>& connection,
		const sp<RpcSession>& session, uint64_t address);

		/**
		* The ownership model here carries an implicit strong refcount whenever a
		* binder is sent across processes. Since we have a local strong count in
		* sp<> over these objects, we only ever need to keep one of these. So,
		* typically we tell the remote process that we drop all the implicit dec
		* strongs, and we hold onto the last one. 'target' here is the target
		* timesRecd (the number of remaining reference counts) we wish to keep.
		* Typically this should be '0' or '1'. The target is used instead of an
		* explicit decrement count in order to allow multiple threads to lower the
		* number of counts simultaneously. Since we only lower the count to 0 when
		* a binder is deleted, targets of '1' should only be sent when the caller
		* owns a local strong reference to the binder. Larger targets may be used
		* for testing, and to make the function generic, but generally this should
		* be avoided because it would be hard to guarantee another thread doesn't
		* lower the number of held refcounts to '1'. Note also, these refcounts
		* must be sent actively. If they are sent when binders are deleted, this
		* can cause leaks, since even remote binders carry an implicit strong ref
		* when they are sent to another process.
		*/
		[[nodiscard]] status_t sendDecStrongToTarget(const sp<RpcSession::RpcConnection>& connection,
		const sp<RpcSession>& session, uint64_t address,
		size_t target);

		enum class CommandType {
		ANY,
		@@ -108,6 +129,13 @@ public:
		*/
		[[nodiscard]] status_t onBinderEntering(const sp<RpcSession>& session, uint64_t address,
		sp<IBinder>* out);
		/**
		* Called on incoming binders to update refcounting information. This should
		* only be called when it is done as part of making progress on a
		* transaction.
		*/
		[[nodiscard]] status_t flushExcessBinderRefs(const sp<RpcSession>& session, uint64_t address,
		const sp<IBinder>& binder);

		size_t countBinders();
		void dump();

libs/binder/RpcWireFormat.h

+8 −1

Original line number	Diff line number	Diff line
		@@ -85,7 +85,7 @@ enum : uint32_t {
		*/
		RPC_COMMAND_REPLY,
		/**
		* follows is RpcWireAddress
		* follows is RpcDecStrong
		*
		* note - this in the protocol directly instead of as a 'special
		* transaction' in order to keep it as lightweight as possible (we don't
		@@ -117,6 +117,13 @@ struct RpcWireHeader {
		};
		static_assert(sizeof(RpcWireHeader) == 16);

		struct RpcDecStrong {
		RpcWireAddress address;
		uint32_t amount;
		uint32_t reserved;
		};
		static_assert(sizeof(RpcDecStrong) == 16);

		struct RpcWireTransaction {
		RpcWireAddress address;
		uint32_t code;