Don't bind-mount bionic files am: 7b4801a921 (f90d8479) · Commits · e / os / android_system_core

init/builtins.cpp

+0 −9

Original line number	Diff line number	Diff line
		@@ -1118,14 +1118,6 @@ static Result<Success> do_parse_apex_configs(const BuiltinArguments& args) {
		}
		}

		static Result<Success> do_setup_runtime_bionic(const BuiltinArguments& args) {
		if (SetupRuntimeBionic()) {
		return Success();
		} else {
		return Error() << "Failed to setup runtime bionic";
		}
		}

		static Result<Success> do_enter_default_mount_ns(const BuiltinArguments& args) {
		if (SwitchToDefaultMountNamespace()) {
		return Success();
		@@ -1181,7 +1173,6 @@ const BuiltinFunctionMap::Map& BuiltinFunctionMap::map() const {
		{"rmdir", {1, 1, {true, do_rmdir}}},
		{"setprop", {2, 2, {true, do_setprop}}},
		{"setrlimit", {3, 3, {false, do_setrlimit}}},
		{"setup_runtime_bionic", {0, 0, {false, do_setup_runtime_bionic}}},
		{"start", {1, 1, {false, do_start}}},
		{"stop", {1, 1, {false, do_stop}}},
		{"swapon_all", {1, 1, {false, do_swapon_all}}},

init/mount_namespace.cpp

+5 −115

Original line number	Diff line number	Diff line
		@@ -33,37 +33,6 @@ namespace android {
		namespace init {
		namespace {

		static constexpr const char* kLinkerMountPoint = "/bionic/bin/linker";
		static constexpr const char* kBootstrapLinkerPath = "/system/bin/bootstrap/linker";
		static constexpr const char* kRuntimeLinkerPath = "/apex/com.android.runtime/bin/linker";

		static constexpr const char* kBionicLibsMountPointDir = "/bionic/lib/";
		static constexpr const char* kBootstrapBionicLibsDir = "/system/lib/bootstrap/";
		static constexpr const char* kRuntimeBionicLibsDir = "/apex/com.android.runtime/lib/bionic/";

		static constexpr const char* kLinkerMountPoint64 = "/bionic/bin/linker64";
		static constexpr const char* kBootstrapLinkerPath64 = "/system/bin/bootstrap/linker64";
		static constexpr const char* kRuntimeLinkerPath64 = "/apex/com.android.runtime/bin/linker64";

		static constexpr const char* kBionicLibsMountPointDir64 = "/bionic/lib64/";
		static constexpr const char* kBootstrapBionicLibsDir64 = "/system/lib64/bootstrap/";
		static constexpr const char* kRuntimeBionicLibsDir64 = "/apex/com.android.runtime/lib64/bionic/";

		static const std::vector<std::string> kBionicLibFileNames = {"libc.so", "libm.so", "libdl.so"};

		static bool BindMount(const std::string& source, const std::string& mount_point,
		bool recursive = false) {
		unsigned long mountflags = MS_BIND;
		if (recursive) {
		mountflags \|= MS_REC;
		}
		if (mount(source.c_str(), mount_point.c_str(), nullptr, mountflags, nullptr) == -1) {
		PLOG(ERROR) << "Could not bind-mount " << source << " to " << mount_point;
		return false;
		}
		return true;
		}

		static bool MakeShared(const std::string& mount_point, bool recursive = false) {
		unsigned long mountflags = MS_SHARED;
		if (recursive) {
		@@ -105,34 +74,6 @@ static std::string GetMountNamespaceId() {
		return ret;
		}

		static bool BindMountBionic(const std::string& linker_source, const std::string& lib_dir_source,
		const std::string& linker_mount_point,
		const std::string& lib_mount_dir) {
		if (access(linker_source.c_str(), F_OK) != 0) {
		PLOG(INFO) << linker_source << " does not exist. skipping mounting bionic there.";
		// This can happen for 64-bit bionic in 32-bit only device.
		// It is okay to skip mounting the 64-bit bionic.
		return true;
		}
		if (!BindMount(linker_source, linker_mount_point)) {
		return false;
		}
		if (!MakePrivate(linker_mount_point)) {
		return false;
		}
		for (const auto& libname : kBionicLibFileNames) {
		std::string mount_point = lib_mount_dir + libname;
		std::string source = lib_dir_source + libname;
		if (!BindMount(source, mount_point)) {
		return false;
		}
		if (!MakePrivate(mount_point)) {
		return false;
		}
		}
		return true;
		}

		static bool IsApexUpdatable() {
		static bool updatable = android::sysprop::ApexProperties::updatable().value_or(false);
		return updatable;
		@@ -154,26 +95,7 @@ bool SetupMountNamespaces() {
		// point to private.
		if (!MakeShared("/", true /recursive/)) return false;

		// Since different files (bootstrap or runtime APEX) should be mounted to
		// the same mount point paths (e.g. /bionic/bin/linker, /bionic/lib/libc.so,
		// etc.) across the two mount namespaces, we create a private mount point at
		// /bionic so that a mount event for the bootstrap bionic in the mount
		// namespace for pre-apexd processes is not propagated to the other mount
		// namespace for post-apexd process, and vice versa.
		//
		// Other mount points other than /bionic, however, are all still shared.
		if (!BindMount("/bionic", "/bionic", true /recursive/)) return false;
		if (!MakePrivate("/bionic")) return false;

		// Bind-mount bootstrap bionic.
		if (!BindMountBionic(kBootstrapLinkerPath, kBootstrapBionicLibsDir, kLinkerMountPoint,
		kBionicLibsMountPointDir))
		return false;
		if (!BindMountBionic(kBootstrapLinkerPath64, kBootstrapBionicLibsDir64, kLinkerMountPoint64,
		kBionicLibsMountPointDir64))
		return false;

		// /apex is also a private mountpoint to give different sets of APEXes for
		// /apex is a private mountpoint to give different sets of APEXes for
		// the bootstrap and default mount namespaces. The processes running with
		// the bootstrap namespace get APEXes from the read-only partition.
		if (!(MakePrivate("/apex"))) return false;
		@@ -181,12 +103,11 @@ bool SetupMountNamespaces() {
		bootstrap_ns_fd.reset(OpenMountNamespace());
		bootstrap_ns_id = GetMountNamespaceId();

		// When bionic is updatable via the runtime APEX, we create separate mount
		// When APEXes are updatable (e.g. not-flattened), we create separate mount
		// namespaces for processes that are started before and after the APEX is
		// activated by apexd. In the namespace for pre-apexd processes, the bionic
		// from the /system partition (that we call bootstrap bionic) is
		// bind-mounted. In the namespace for post-apexd processes, the bionic from
		// the runtime APEX is bind-mounted.
		// activated by apexd. In the namespace for pre-apexd processes, small
		// number of essential APEXes (e.g. com.android.runtime) are activated.
		// In the namespace for post-apexd processes, all APEXes are activated.
		bool success = true;
		if (IsApexUpdatable() && !IsRecoveryMode()) {
		// Creating a new namespace by cloning, saving, and switching back to
		@@ -198,15 +119,6 @@ bool SetupMountNamespaces() {
		default_ns_fd.reset(OpenMountNamespace());
		default_ns_id = GetMountNamespaceId();

		// By this unmount, the bootstrap bionic are not mounted in the default
		// mount namespace.
		if (umount2("/bionic", MNT_DETACH) == -1) {
		PLOG(ERROR) << "Cannot unmount /bionic";
		// Don't return here. We have to switch back to the bootstrap
		// namespace.
		success = false;
		}

		if (setns(bootstrap_ns_fd.get(), CLONE_NEWNS) == -1) {
		PLOG(ERROR) << "Cannot switch back to bootstrap mount namespace";
		return false;
		@@ -237,28 +149,6 @@ bool SwitchToDefaultMountNamespace() {
		return true;
		}

		// TODO(jiyong): remove this when /system/lib/libc.so becomes
		// a symlink to /apex/com.android.runtime/lib/bionic/libc.so
		bool SetupRuntimeBionic() {
		if (IsRecoveryMode()) {
		// We don't have multiple namespaces in recovery mode
		return true;
		}
		// Bind-mount bionic from the runtime APEX since it is now available. Note
		// that in case of IsApexUpdatable() == false, these mounts are over the
		// existing existing bind mounts for the bootstrap bionic, which effectively
		// becomes hidden.
		if (!BindMountBionic(kRuntimeLinkerPath, kRuntimeBionicLibsDir, kLinkerMountPoint,
		kBionicLibsMountPointDir))
		return false;
		if (!BindMountBionic(kRuntimeLinkerPath64, kRuntimeBionicLibsDir64, kLinkerMountPoint64,
		kBionicLibsMountPointDir64))
		return false;

		LOG(INFO) << "Runtime bionic is set up";
		return true;
		}

		bool SwitchToBootstrapMountNamespaceIfNeeded() {
		if (IsRecoveryMode()) {
		// we don't have multiple namespaces in recovery mode

init/mount_namespace.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -20,7 +20,6 @@ namespace android {
		namespace init {

		bool SetupMountNamespaces();
		bool SetupRuntimeBionic();
		bool SwitchToDefaultMountNamespace();
		bool SwitchToBootstrapMountNamespaceIfNeeded();

rootdir/etc/ld.config.txt

+2 −2

Original line number	Diff line number	Diff line
		@@ -83,7 +83,7 @@ namespace.default.permitted.paths += /%PRODUCT_SERVICES%/app
		namespace.default.permitted.paths += /%PRODUCT_SERVICES%/priv-app
		namespace.default.permitted.paths += /data
		namespace.default.permitted.paths += /mnt/expand
		namespace.default.permitted.paths += /bionic/${LIB}
		namespace.default.permitted.paths += /apex/com.android.runtime/${LIB}/bionic
		namespace.default.permitted.paths += /system/${LIB}/bootstrap

		namespace.default.asan.search.paths = /data/asan/system/${LIB}
		@@ -119,7 +119,7 @@ namespace.default.asan.permitted.paths += /%PRODUCT_SERVICES%/framework
		namespace.default.asan.permitted.paths += /%PRODUCT_SERVICES%/app
		namespace.default.asan.permitted.paths += /%PRODUCT_SERVICES%/priv-app
		namespace.default.asan.permitted.paths += /mnt/expand
		namespace.default.asan.permitted.paths += /bionic/${LIB}
		namespace.default.asan.permitted.paths += /apex/com.android.runtime/${LIB}/bionic
		namespace.default.asan.permitted.paths += /system/${LIB}/bootstrap

		# Keep in sync with ld.config.txt in the com.android.runtime APEX.

rootdir/init.rc

+0 −2

Original line number	Diff line number	Diff line
		@@ -578,8 +578,6 @@ on post-fs-data

		# Wait for apexd to finish activating APEXes before starting more processes.
		wait_for_prop apexd.status ready
		# TODO(jiyong): remove setup_runtime_bionic
		setup_runtime_bionic
		parse_apex_configs

		init_user0