Merge "init: start ueventd in the default mount namespace" (7cc98e21) · Commits · e / os / android_system_core

init/builtins.cpp

+21 −4

Original line number	Diff line number	Diff line
		@@ -1221,6 +1221,20 @@ static Result<void> GenerateLinkerConfiguration() {
		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 updatable = android::sysprop::ApexProperties::updatable().value_or(false);
		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) {
		if (SwitchToDefaultMountNamespace()) {
		return {};
		} else {
		return Error() << "Failed to enter into default mount namespace";
		if (auto result = SwitchToMountNamespaceIfNeeded(NS_DEFAULT); !result.ok()) {
		return result.error();
		}
		if (auto result = MountLinkerConfigForDefaultNamespace(); !result.ok()) {
		return result.error();
		}
		LOG(INFO) << "Switched to default mount namespace";
		return {};
		}

		// Builtin-function-map start

init/mount_namespace.cpp

+11 −45

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

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

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

		} // namespace init

init/mount_namespace.h

+5 −2

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

		#pragma once

		#include <android-base/result.h>

		namespace android {
		namespace init {

		enum MountNamespace { NS_BOOTSTRAP, NS_DEFAULT };

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

		} // namespace init
		} // namespace android

init/reboot.cpp

+1 −1

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

init/service.cpp

+12 −1

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

		LOG(INFO) << "starting service '" << name_ << "'...";
		@@ -496,7 +506,8 @@ Result<void> Service::Start() {
		if (pid == 0) {
		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_
		<< "' failed to set up namespaces: " << result.error();
		}