Merge "libbinder: allow stability downgrade" (7f284f96) · Commits · e / os / android_frameworks_native

libs/binder/Stability.cpp

+30 −7

Original line number	Diff line number	Diff line
		@@ -38,6 +38,18 @@ Stability::Category Stability::Category::currentFromLevel(Level level) {
		};
		}

		void Stability::forceDowngradeCompilationUnit(const sp<IBinder>& binder) {
		// Downgrading a remote binder would require also copying the version from
		// the binder sent here. In practice though, we don't need to downgrade the
		// stability of a remote binder, since this would as an effect only restrict
		// what we can do to it.
		LOG_ALWAYS_FATAL_IF(!binder \|\| !binder->localBinder(), "Can only downgrade local binder");

		auto stability = Category::currentFromLevel(getLocalLevel());
		status_t result = setRepr(binder.get(), stability.repr(), REPR_LOG \| REPR_ALLOW_DOWNGRADE);
		LOG_ALWAYS_FATAL_IF(result != OK, "Should only mark known object.");
		}

		std::string Stability::Category::debugString() {
		return levelString(level) + " wire protocol version "
		+ std::to_string(version);
		@@ -45,13 +57,13 @@ std::string Stability::Category::debugString() {

		void Stability::markCompilationUnit(IBinder* binder) {
		auto stability = Category::currentFromLevel(getLocalLevel());
		status_t result = setRepr(binder, stability.repr(), true /log/);
		status_t result = setRepr(binder, stability.repr(), REPR_LOG);
		LOG_ALWAYS_FATAL_IF(result != OK, "Should only mark known object.");
		}

		void Stability::markVintf(IBinder* binder) {
		auto stability = Category::currentFromLevel(Level::VINTF);
		status_t result = setRepr(binder, stability.repr(), true /log/);
		status_t result = setRepr(binder, stability.repr(), REPR_LOG);
		LOG_ALWAYS_FATAL_IF(result != OK, "Should only mark known object.");
		}

		@@ -62,7 +74,7 @@ void Stability::debugLogStability(const std::string& tag, const sp<IBinder>& bin

		void Stability::markVndk(IBinder* binder) {
		auto stability = Category::currentFromLevel(Level::VENDOR);
		status_t result = setRepr(binder, stability.repr(), true /log/);
		status_t result = setRepr(binder, stability.repr(), REPR_LOG);
		LOG_ALWAYS_FATAL_IF(result != OK, "Should only mark known object.");
		}

		@@ -72,7 +84,7 @@ bool Stability::requiresVintfDeclaration(const sp<IBinder>& binder) {

		void Stability::tryMarkCompilationUnit(IBinder* binder) {
		auto stability = Category::currentFromLevel(getLocalLevel());
		(void) setRepr(binder, stability.repr(), false /log/);
		(void) setRepr(binder, stability.repr(), REPR_NONE);
		}

		Stability::Level Stability::getLocalLevel() {
		@@ -94,7 +106,10 @@ Stability::Level Stability::getLocalLevel() {
		#endif
		}

		status_t Stability::setRepr(IBinder* binder, int32_t representation, bool log) {
		status_t Stability::setRepr(IBinder* binder, int32_t representation, uint32_t flags) {
		bool log = flags & REPR_LOG;
		bool allowDowngrade = flags & REPR_ALLOW_DOWNGRADE;

		auto current = getCategory(binder);
		auto setting = Category::fromRepr(representation);

		@@ -129,7 +144,11 @@ status_t Stability::setRepr(IBinder* binder, int32_t representation, bool log) {
		return BAD_TYPE;
		}

		if (current.repr() != 0 && current != setting) {
		if (current == setting) return OK;

		bool hasAlreadyBeenSet = current.repr() != 0;
		bool isAllowedDowngrade = allowDowngrade && check(current, setting.level);
		if (hasAlreadyBeenSet && !isAllowedDowngrade) {
		if (log) {
		ALOGE("Interface being set with %s but it is already marked as %s",
		setting.debugString().c_str(),
		@@ -138,7 +157,11 @@ status_t Stability::setRepr(IBinder* binder, int32_t representation, bool log) {
		return BAD_TYPE;
		}

		if (current == setting) return OK;
		if (isAllowedDowngrade) {
		ALOGI("Interface set with %s downgraded to %s stability",
		current.debugString().c_str(),
		setting.debugString().c_str());
		}

		BBinder* local = binder->localBinder();
		if (local != nullptr) {

libs/binder/include/binder/Stability.h

+15 −3

Original line number	Diff line number	Diff line
		@@ -49,10 +49,17 @@ namespace internal {
		// that it knows how to process. The summary of stability of a binder is
		// represented by a Stability::Category object.

		// WARNING: These APIs are only ever expected to be called by auto-generated code.
		// Instead of calling them, you should set the stability of a .aidl interface
		class Stability final {
		public:
		// Given a binder interface at a certain stability, there may be some
		// requirements associated with that higher stability level. For instance, a
		// VINTF stability binder is required to be in the VINTF manifest. This API
		// can be called to use that same interface within a partition.
		static void forceDowngradeCompilationUnit(const sp<IBinder>& binder);

		// WARNING: Below APIs are only ever expected to be called by auto-generated code.
		// Instead of calling them, you should set the stability of a .aidl interface

		// WARNING: This is only ever expected to be called by auto-generated code. You likely want to
		// change or modify the stability class of the interface you are using.
		// This must be called as soon as the binder in question is constructed. No thread safety
		@@ -139,9 +146,14 @@ private:
		// returns the stability according to how this was built
		static Level getLocalLevel();

		enum {
		REPR_NONE = 0,
		REPR_LOG = 1,
		REPR_ALLOW_DOWNGRADE = 2,
		};
		// applies stability to binder if stability level is known
		__attribute__((warn_unused_result))
		static status_t setRepr(IBinder* binder, int32_t representation, bool log);
		static status_t setRepr(IBinder* binder, int32_t representation, uint32_t flags);

		// get stability information as encoded on the wire
		static Category getCategory(IBinder* binder);

libs/binder/tests/binderStabilityTest.cpp

+11 −0

Original line number	Diff line number	Diff line
		@@ -131,6 +131,17 @@ TEST(BinderStability, OnlyVintfStabilityBinderNeedsVintfDeclaration) {
		EXPECT_TRUE(Stability::requiresVintfDeclaration(BadStableBinder::vintf()));
		}

		TEST(BinderStability, ForceDowngradeStability) {
		sp<IBinder> someBinder = BadStableBinder::vintf();

		EXPECT_TRUE(Stability::requiresVintfDeclaration(someBinder));

		// silly to do this after already using the binder, but it's for the test
		Stability::forceDowngradeCompilationUnit(someBinder);

		EXPECT_FALSE(Stability::requiresVintfDeclaration(someBinder));
		}

		TEST(BinderStability, VintfStabilityServerMustBeDeclaredInManifest) {
		sp<IBinder> vintfServer = BadStableBinder::vintf();