Merge "Copy snapuserd to first_stage_ramdisk" (4767dcca) · Commits · e / os / android_system_core

init/first_stage_init.cpp

+37 −3

Original line number	Diff line number	Diff line
		@@ -27,6 +27,7 @@
		#include <sys/utsname.h>
		#include <unistd.h>

		#include <chrono>
		#include <filesystem>
		#include <string>
		#include <vector>
		@@ -107,6 +108,39 @@ bool ForceNormalBoot(const std::string& cmdline, const std::string& bootconfig)
		cmdline.find("androidboot.force_normal_boot=1") != std::string::npos;
		}

		static void Copy(const char* src, const char* dst) {
		if (link(src, dst) == 0) {
		LOG(INFO) << "hard linking " << src << " to " << dst << " succeeded";
		return;
		}
		PLOG(FATAL) << "hard linking " << src << " to " << dst << " failed, falling back to copy.";
		}

		// Move e2fsck before switching root, so that it is available at the same path
		// after switching root.
		void PrepareSwitchRoot() {
		constexpr const char* src = "/system/bin/snapuserd";
		constexpr const char* dst = "/first_stage_ramdisk/system/bin/snapuserd";

		if (access(dst, X_OK) == 0) {
		LOG(INFO) << dst << " already exists and it can be executed";
		return;
		}

		if (access(src, F_OK) != 0) {
		PLOG(INFO) << "Not moving " << src << " because it cannot be accessed";
		return;
		}

		auto dst_dir = android::base::Dirname(dst);
		std::error_code ec;
		if (access(dst_dir.c_str(), F_OK) != 0) {
		if (!fs::create_directories(dst_dir, ec)) {
		LOG(FATAL) << "Cannot create " << dst_dir << ": " << ec.message();
		}
		}
		Copy(src, dst);
		}
		} // namespace

		std::string GetModuleLoadList(bool recovery, const std::string& dir_path) {
		@@ -304,7 +338,6 @@ int FirstStageMain(int argc, char** argv) {
		<< module_elapse_time.count() << " ms";
		}


		bool created_devices = false;
		if (want_console == FirstStageConsoleParam::CONSOLE_ON_FAILURE) {
		if (!IsRecoveryMode()) {
		@@ -352,10 +385,11 @@ int FirstStageMain(int argc, char** argv) {

		if (ForceNormalBoot(cmdline, bootconfig)) {
		mkdir("/first_stage_ramdisk", 0755);
		PrepareSwitchRoot();
		// SwitchRoot() must be called with a mount point as the target, so we bind mount the
		// target directory to itself here.
		if (mount("/first_stage_ramdisk", "/first_stage_ramdisk", nullptr, MS_BIND, nullptr) != 0) {
		LOG(FATAL) << "Could not bind mount /first_stage_ramdisk to itself";
		PLOG(FATAL) << "Could not bind mount /first_stage_ramdisk to itself";
		}
		SwitchRoot("/first_stage_ramdisk");
		}

init/switch_root.cpp

+2 −1

Original line number	Diff line number	Diff line
		@@ -78,7 +78,8 @@ void SwitchRoot(const std::string& new_root) {
		auto new_mount_path = new_root + mount_path;
		mkdir(new_mount_path.c_str(), 0755);
		if (mount(mount_path.c_str(), new_mount_path.c_str(), nullptr, MS_MOVE, nullptr) != 0) {
		PLOG(FATAL) << "Unable to move mount at '" << mount_path << "'";
		PLOG(FATAL) << "Unable to move mount at '" << mount_path << "' to "
		<< "'" << new_mount_path << "'";
		}
		}