init: start ueventd in the default mount namespace (4f23d5a2) · Commits · e / os / android_system_core

init/builtins.cpp

+21 −4

Original line number	Original line	Diff line number	Diff line
	@@ -1221,6 +1221,20 @@ static Result<void> GenerateLinkerConfiguration() {
	return {};		return {};
	}		}

			static Result<void> MountLinkerConfigForDefaultNamespace() {
			// No need to mount linkerconfig for default mount namespace if the path does not exist (which
			// would mean it is already mounted)
			if (access("/linkerconfig/default", 0) != 0) {
			return {};
			}

			if (mount("/linkerconfig/default", "/linkerconfig", nullptr, MS_BIND \| MS_REC, nullptr) != 0) {
			return ErrnoError() << "Failed to mount linker configuration for default mount namespace.";
			}

			return {};
			}

	static bool IsApexUpdatable() {		static bool IsApexUpdatable() {
	static bool updatable = android::sysprop::ApexProperties::updatable().value_or(false);		static bool updatable = android::sysprop::ApexProperties::updatable().value_or(false);
	return updatable;		return updatable;
	@@ -1319,11 +1333,14 @@ static Result<void> do_perform_apex_config(const BuiltinArguments& args) {
	}		}

	static Result<void> do_enter_default_mount_ns(const BuiltinArguments& args) {		static Result<void> do_enter_default_mount_ns(const BuiltinArguments& args) {
	if (SwitchToDefaultMountNamespace()) {		if (auto result = SwitchToMountNamespaceIfNeeded(NS_DEFAULT); !result.ok()) {
	return {};		return result.error();
	} else {		}
	return Error() << "Failed to enter into default mount namespace";		if (auto result = MountLinkerConfigForDefaultNamespace(); !result.ok()) {
			return result.error();
	}		}
			LOG(INFO) << "Switched to default mount namespace";
			return {};
	}		}

	// Builtin-function-map start		// Builtin-function-map start

init/mount_namespace.cpp

+11 −45

Original line number	Original line	Diff line number	Diff line
	@@ -176,20 +176,6 @@ static bool ActivateFlattenedApexesIfPossible() {
	return true;		return true;
	}		}

	static Result<void> MountLinkerConfigForDefaultNamespace() {
	// No need to mount linkerconfig for default mount namespace if the path does not exist (which
	// would mean it is already mounted)
	if (access("/linkerconfig/default", 0) != 0) {
	return {};
	}

	if (mount("/linkerconfig/default", "/linkerconfig", nullptr, MS_BIND \| MS_REC, nullptr) != 0) {
	return ErrnoError() << "Failed to mount linker configuration for default mount namespace.";
	}

	return {};
	}

	static android::base::unique_fd bootstrap_ns_fd;		static android::base::unique_fd bootstrap_ns_fd;
	static android::base::unique_fd default_ns_fd;		static android::base::unique_fd default_ns_fd;

	@@ -290,40 +276,20 @@ bool SetupMountNamespaces() {
	return success;		return success;
	}		}

	bool SwitchToDefaultMountNamespace() {		Result<void> SwitchToMountNamespaceIfNeeded(MountNamespace target_mount_namespace) {
	if (IsRecoveryMode()) {		if (IsRecoveryMode() \|\| !IsApexUpdatable()) {
	// we don't have multiple namespaces in recovery mode		// we don't have multiple namespaces in recovery mode or if apex is not updatable
	return true;		return {};
	}
	if (default_ns_id != GetMountNamespaceId()) {
	if (setns(default_ns_fd.get(), CLONE_NEWNS) == -1) {
	PLOG(ERROR) << "Failed to switch back to the default mount namespace.";
	return false;
	}

	if (auto result = MountLinkerConfigForDefaultNamespace(); !result.ok()) {
	LOG(ERROR) << result.error();
	return false;
	}
	}

	LOG(INFO) << "Switched to default mount namespace";
	return true;
	}

	bool SwitchToBootstrapMountNamespaceIfNeeded() {
	if (IsRecoveryMode()) {
	// we don't have multiple namespaces in recovery mode
	return true;
	}		}
	if (bootstrap_ns_id != GetMountNamespaceId() && bootstrap_ns_fd.get() != -1 &&		const auto& ns_id = target_mount_namespace == NS_BOOTSTRAP ? bootstrap_ns_id : default_ns_id;
	IsApexUpdatable()) {		const auto& ns_fd = target_mount_namespace == NS_BOOTSTRAP ? bootstrap_ns_fd : default_ns_fd;
	if (setns(bootstrap_ns_fd.get(), CLONE_NEWNS) == -1) {		const auto& ns_name = target_mount_namespace == NS_BOOTSTRAP ? "bootstrap" : "default";
	PLOG(ERROR) << "Failed to switch to bootstrap mount namespace.";		if (ns_id != GetMountNamespaceId() && ns_fd.get() != -1) {
	return false;		if (setns(ns_fd.get(), CLONE_NEWNS) == -1) {
			return ErrnoError() << "Failed to switch to " << ns_name << " mount namespace.";
	}		}
	}		}
	return true;		return {};
	}		}

	} // namespace init		} // namespace init

init/mount_namespace.h

+5 −2

Original line number	Original line	Diff line number	Diff line
	@@ -16,12 +16,15 @@

	#pragma once		#pragma once

			#include <android-base/result.h>

	namespace android {		namespace android {
	namespace init {		namespace init {

			enum MountNamespace { NS_BOOTSTRAP, NS_DEFAULT };

	bool SetupMountNamespaces();		bool SetupMountNamespaces();
	bool SwitchToDefaultMountNamespace();		base::Result<void> SwitchToMountNamespaceIfNeeded(MountNamespace target_mount_namespace);
	bool SwitchToBootstrapMountNamespaceIfNeeded();

	} // namespace init		} // namespace init
	} // namespace android		} // namespace android

init/reboot.cpp

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -831,7 +831,7 @@ static Result<void> DoUserspaceReboot() {
	sub_reason = "apex";		sub_reason = "apex";
	return result;		return result;
	}		}
	if (!SwitchToBootstrapMountNamespaceIfNeeded()) {		if (!SwitchToMountNamespaceIfNeeded(NS_BOOTSTRAP)) {
	sub_reason = "ns_switch";		sub_reason = "ns_switch";
	return Error() << "Failed to switch to bootstrap namespace";		return Error() << "Failed to switch to bootstrap namespace";
	}		}

init/service.cpp

+12 −1

Original line number	Original line	Diff line number	Diff line
	@@ -465,6 +465,16 @@ Result<void> Service::Start() {
	pre_apexd_ = true;		pre_apexd_ = true;
	}		}

			// For pre-apexd services, override mount namespace as "bootstrap" one before starting.
			// Note: "ueventd" is supposed to be run in "default" mount namespace even if it's pre-apexd
			// to support loading firmwares from APEXes.
			std::optional<MountNamespace> override_mount_namespace;
			if (name_ == "ueventd") {
			override_mount_namespace = NS_DEFAULT;
			} else if (pre_apexd_) {
			override_mount_namespace = NS_BOOTSTRAP;
			}

	post_data_ = ServiceList::GetInstance().IsPostData();		post_data_ = ServiceList::GetInstance().IsPostData();

	LOG(INFO) << "starting service '" << name_ << "'...";		LOG(INFO) << "starting service '" << name_ << "'...";
	@@ -496,7 +506,8 @@ Result<void> Service::Start() {
	if (pid == 0) {		if (pid == 0) {
	umask(077);		umask(077);

	if (auto result = EnterNamespaces(namespaces_, name_, pre_apexd_); !result.ok()) {		if (auto result = EnterNamespaces(namespaces_, name_, override_mount_namespace);
			!result.ok()) {
	LOG(FATAL) << "Service '" << name_		LOG(FATAL) << "Service '" << name_
	<< "' failed to set up namespaces: " << result.error();		<< "' failed to set up namespaces: " << result.error();
	}		}