/* * Copyright (C) 2017 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include "reboot.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "action_manager.h" #include "init.h" #include "property_service.h" #include "reboot_utils.h" #include "service.h" #include "service_list.h" #include "sigchld_handler.h" #define PROC_SYSRQ "/proc/sysrq-trigger" using android::base::GetBoolProperty; using android::base::Split; using android::base::Timer; using android::base::unique_fd; using android::base::WriteStringToFile; namespace android { namespace init { // represents umount status during reboot / shutdown. enum UmountStat { /* umount succeeded. */ UMOUNT_STAT_SUCCESS = 0, /* umount was not run. */ UMOUNT_STAT_SKIPPED = 1, /* umount failed with timeout. */ UMOUNT_STAT_TIMEOUT = 2, /* could not run due to error */ UMOUNT_STAT_ERROR = 3, /* not used by init but reserved for other part to use this to represent the the state where umount status before reboot is not found / available. */ UMOUNT_STAT_NOT_AVAILABLE = 4, }; // Utility for struct mntent class MountEntry { public: explicit MountEntry(const mntent& entry) : mnt_fsname_(entry.mnt_fsname), mnt_dir_(entry.mnt_dir), mnt_type_(entry.mnt_type), mnt_opts_(entry.mnt_opts) {} bool Umount(bool force) { LOG(INFO) << "Unmounting " << mnt_fsname_ << ":" << mnt_dir_ << " opts " << mnt_opts_; int r = umount2(mnt_dir_.c_str(), force ? MNT_FORCE : 0); if (r == 0) { LOG(INFO) << "Umounted " << mnt_fsname_ << ":" << mnt_dir_ << " opts " << mnt_opts_; return true; } else { PLOG(WARNING) << "Cannot umount " << mnt_fsname_ << ":" << mnt_dir_ << " opts " << mnt_opts_; return false; } } void DoFsck() { int st; if (IsF2Fs()) { const char* f2fs_argv[] = { "/system/bin/fsck.f2fs", "-a", mnt_fsname_.c_str(), }; android_fork_execvp_ext(arraysize(f2fs_argv), (char**)f2fs_argv, &st, true, LOG_KLOG, true, nullptr, nullptr, 0); } else if (IsExt4()) { const char* ext4_argv[] = { "/system/bin/e2fsck", "-y", mnt_fsname_.c_str(), }; android_fork_execvp_ext(arraysize(ext4_argv), (char**)ext4_argv, &st, true, LOG_KLOG, true, nullptr, nullptr, 0); } } static bool IsBlockDevice(const struct mntent& mntent) { return android::base::StartsWith(mntent.mnt_fsname, "/dev/block"); } static bool IsEmulatedDevice(const struct mntent& mntent) { return android::base::StartsWith(mntent.mnt_fsname, "/data/"); } private: bool IsF2Fs() const { return mnt_type_ == "f2fs"; } bool IsExt4() const { return mnt_type_ == "ext4"; } std::string mnt_fsname_; std::string mnt_dir_; std::string mnt_type_; std::string mnt_opts_; }; // Turn off backlight while we are performing power down cleanup activities. static void TurnOffBacklight() { Service* service = ServiceList::GetInstance().FindService("blank_screen"); if (service == nullptr) { LOG(WARNING) << "cannot find blank_screen in TurnOffBacklight"; return; } if (auto result = service->Start(); !result) { LOG(WARNING) << "Could not start blank_screen service: " << result.error(); } } static void ShutdownVold() { const char* vdc_argv[] = {"/system/bin/vdc", "volume", "shutdown"}; int status; android_fork_execvp_ext(arraysize(vdc_argv), (char**)vdc_argv, &status, true, LOG_KLOG, true, nullptr, nullptr, 0); } static void LogShutdownTime(UmountStat stat, Timer* t) { LOG(WARNING) << "powerctl_shutdown_time_ms:" << std::to_string(t->duration().count()) << ":" << stat; } /* Find all read+write block devices and emulated devices in /proc/mounts * and add them to correpsponding list. */ static bool FindPartitionsToUmount(std::vector* blockDevPartitions, std::vector* emulatedPartitions, bool dump) { std::unique_ptr fp(setmntent("/proc/mounts", "re"), endmntent); if (fp == nullptr) { PLOG(ERROR) << "Failed to open /proc/mounts"; return false; } mntent* mentry; while ((mentry = getmntent(fp.get())) != nullptr) { if (dump) { LOG(INFO) << "mount entry " << mentry->mnt_fsname << ":" << mentry->mnt_dir << " opts " << mentry->mnt_opts << " type " << mentry->mnt_type; } else if (MountEntry::IsBlockDevice(*mentry) && hasmntopt(mentry, "rw")) { std::string mount_dir(mentry->mnt_dir); // These are R/O partitions changed to R/W after adb remount. // Do not umount them as shutdown critical services may rely on them. if (mount_dir != "/" && mount_dir != "/system" && mount_dir != "/vendor" && mount_dir != "/oem") { blockDevPartitions->emplace(blockDevPartitions->begin(), *mentry); } } else if (MountEntry::IsEmulatedDevice(*mentry)) { emulatedPartitions->emplace(emulatedPartitions->begin(), *mentry); } } return true; } static void DumpUmountDebuggingInfo() { int status; if (!security_getenforce()) { LOG(INFO) << "Run lsof"; const char* lsof_argv[] = {"/system/bin/lsof"}; android_fork_execvp_ext(arraysize(lsof_argv), (char**)lsof_argv, &status, true, LOG_KLOG, true, nullptr, nullptr, 0); } FindPartitionsToUmount(nullptr, nullptr, true); // dump current CPU stack traces and uninterruptible tasks WriteStringToFile("l", PROC_SYSRQ); WriteStringToFile("w", PROC_SYSRQ); } static UmountStat UmountPartitions(std::chrono::milliseconds timeout) { Timer t; /* data partition needs all pending writes to be completed and all emulated partitions * umounted.If the current waiting is not good enough, give * up and leave it to e2fsck after reboot to fix it. */ while (true) { std::vector block_devices; std::vector emulated_devices; if (!FindPartitionsToUmount(&block_devices, &emulated_devices, false)) { return UMOUNT_STAT_ERROR; } if (block_devices.size() == 0) { return UMOUNT_STAT_SUCCESS; } bool unmount_done = true; if (emulated_devices.size() > 0) { for (auto& entry : emulated_devices) { if (!entry.Umount(false)) unmount_done = false; } if (unmount_done) { sync(); } } for (auto& entry : block_devices) { if (!entry.Umount(timeout == 0ms)) unmount_done = false; } if (unmount_done) { return UMOUNT_STAT_SUCCESS; } if ((timeout < t.duration())) { // try umount at least once return UMOUNT_STAT_TIMEOUT; } std::this_thread::sleep_for(100ms); } } static void KillAllProcesses() { WriteStringToFile("i", PROC_SYSRQ); } // Create reboot/shutdwon monitor thread void RebootMonitorThread(unsigned int cmd, const std::string& rebootTarget, sem_t* reboot_semaphore, std::chrono::milliseconds shutdown_timeout, bool* reboot_monitor_run) { unsigned int remaining_shutdown_time = 0; // 30 seconds more than the timeout passed to the thread as there is a final Umount pass // after the timeout is reached. constexpr unsigned int shutdown_watchdog_timeout_default = 30; auto shutdown_watchdog_timeout = android::base::GetUintProperty( "ro.build.shutdown.watchdog.timeout", shutdown_watchdog_timeout_default); remaining_shutdown_time = shutdown_watchdog_timeout + shutdown_timeout.count() / 1000; while (*reboot_monitor_run == true) { if (TEMP_FAILURE_RETRY(sem_wait(reboot_semaphore)) == -1) { LOG(ERROR) << "sem_wait failed and exit RebootMonitorThread()"; return; } timespec shutdown_timeout_timespec; if (clock_gettime(CLOCK_MONOTONIC, &shutdown_timeout_timespec) == -1) { LOG(ERROR) << "clock_gettime() fail! exit RebootMonitorThread()"; return; } // If there are some remaining shutdown time left from previous round, we use // remaining time here. shutdown_timeout_timespec.tv_sec += remaining_shutdown_time; LOG(INFO) << "shutdown_timeout_timespec.tv_sec: " << shutdown_timeout_timespec.tv_sec; int sem_return = 0; while ((sem_return = sem_timedwait_monotonic_np(reboot_semaphore, &shutdown_timeout_timespec)) == -1 && errno == EINTR) { } if (sem_return == -1) { LOG(ERROR) << "Reboot thread timed out"; if (android::base::GetBoolProperty("ro.debuggable", false) == true) { LOG(INFO) << "Try to dump init process call trace:"; const char* vdc_argv[] = {"/system/bin/debuggerd", "-b", "1"}; int status; android_fork_execvp_ext(arraysize(vdc_argv), (char**)vdc_argv, &status, true, LOG_KLOG, true, nullptr, nullptr, 0); LOG(INFO) << "Show stack for all active CPU:"; WriteStringToFile("l", PROC_SYSRQ); LOG(INFO) << "Show tasks that are in disk sleep(uninterruptable sleep), which are " "like " "blocked in mutex or hardware register access:"; WriteStringToFile("w", PROC_SYSRQ); } // In shutdown case,notify kernel to sync and umount fs to read-only before shutdown. if (cmd == ANDROID_RB_POWEROFF || cmd == ANDROID_RB_THERMOFF) { WriteStringToFile("s", PROC_SYSRQ); WriteStringToFile("u", PROC_SYSRQ); RebootSystem(cmd, rebootTarget); } LOG(ERROR) << "Trigger crash at last!"; WriteStringToFile("c", PROC_SYSRQ); } else { timespec current_time_timespec; if (clock_gettime(CLOCK_MONOTONIC, ¤t_time_timespec) == -1) { LOG(ERROR) << "clock_gettime() fail! exit RebootMonitorThread()"; return; } remaining_shutdown_time = shutdown_timeout_timespec.tv_sec - current_time_timespec.tv_sec; LOG(INFO) << "remaining_shutdown_time: " << remaining_shutdown_time; } } } /* Try umounting all emulated file systems R/W block device cfile systems. * This will just try umount and give it up if it fails. * For fs like ext4, this is ok as file system will be marked as unclean shutdown * and necessary check can be done at the next reboot. * For safer shutdown, caller needs to make sure that * all processes / emulated partition for the target fs are all cleaned-up. * * return true when umount was successful. false when timed out. */ static UmountStat TryUmountAndFsck(unsigned int cmd, const std::string& rebootTarget, bool runFsck, std::chrono::milliseconds timeout, sem_t* reboot_semaphore) { Timer t; std::vector block_devices; std::vector emulated_devices; if (runFsck && !FindPartitionsToUmount(&block_devices, &emulated_devices, false)) { return UMOUNT_STAT_ERROR; } UmountStat stat = UmountPartitions(timeout - t.duration()); if (stat != UMOUNT_STAT_SUCCESS) { LOG(INFO) << "umount timeout, last resort, kill all and try"; if (DUMP_ON_UMOUNT_FAILURE) DumpUmountDebuggingInfo(); KillAllProcesses(); // even if it succeeds, still it is timeout and do not run fsck with all processes killed UmountStat st = UmountPartitions(0ms); if ((st != UMOUNT_STAT_SUCCESS) && DUMP_ON_UMOUNT_FAILURE) DumpUmountDebuggingInfo(); } if (stat == UMOUNT_STAT_SUCCESS && runFsck) { LOG(INFO) << "Pause reboot monitor thread before fsck"; sem_post(reboot_semaphore); // fsck part is excluded from timeout check. It only runs for user initiated shutdown // and should not affect reboot time. for (auto& entry : block_devices) { entry.DoFsck(); } LOG(INFO) << "Resume reboot monitor thread after fsck"; sem_post(reboot_semaphore); } return stat; } // zram is able to use backing device on top of a loopback device. // In order to unmount /data successfully, we have to kill the loopback device first #define ZRAM_DEVICE "/dev/block/zram0" #define ZRAM_RESET "/sys/block/zram0/reset" #define ZRAM_BACK_DEV "/sys/block/zram0/backing_dev" static void KillZramBackingDevice() { std::string backing_dev; if (!android::base::ReadFileToString(ZRAM_BACK_DEV, &backing_dev)) return; if (!android::base::StartsWith(backing_dev, "/dev/block/loop")) return; // cut the last "\n" backing_dev.erase(backing_dev.length() - 1); // shutdown zram handle Timer swap_timer; LOG(INFO) << "swapoff() start..."; if (swapoff(ZRAM_DEVICE) == -1) { LOG(ERROR) << "zram_backing_dev: swapoff (" << backing_dev << ")" << " failed"; return; } LOG(INFO) << "swapoff() took " << swap_timer;; if (!WriteStringToFile("1", ZRAM_RESET)) { LOG(ERROR) << "zram_backing_dev: reset (" << backing_dev << ")" << " failed"; return; } // clear loopback device unique_fd loop(TEMP_FAILURE_RETRY(open(backing_dev.c_str(), O_RDWR | O_CLOEXEC))); if (loop.get() < 0) { LOG(ERROR) << "zram_backing_dev: open(" << backing_dev << ")" << " failed"; return; } if (ioctl(loop.get(), LOOP_CLR_FD, 0) < 0) { LOG(ERROR) << "zram_backing_dev: loop_clear (" << backing_dev << ")" << " failed"; return; } LOG(INFO) << "zram_backing_dev: `" << backing_dev << "` is cleared successfully."; } //* Reboot / shutdown the system. // cmd ANDROID_RB_* as defined in android_reboot.h // reason Reason string like "reboot", "shutdown,userrequested" // rebootTarget Reboot target string like "bootloader". Otherwise, it should be an // empty string. // runFsck Whether to run fsck after umount is done. // static void DoReboot(unsigned int cmd, const std::string& reason, const std::string& rebootTarget, bool runFsck) { Timer t; LOG(INFO) << "Reboot start, reason: " << reason << ", rebootTarget: " << rebootTarget; // Ensure last reboot reason is reduced to canonical // alias reported in bootloader or system boot reason. size_t skip = 0; std::vector reasons = Split(reason, ","); if (reasons.size() >= 2 && reasons[0] == "reboot" && (reasons[1] == "recovery" || reasons[1] == "bootloader" || reasons[1] == "cold" || reasons[1] == "hard" || reasons[1] == "warm")) { skip = strlen("reboot,"); } property_set(LAST_REBOOT_REASON_PROPERTY, reason.c_str() + skip); sync(); bool is_thermal_shutdown = cmd == ANDROID_RB_THERMOFF; auto shutdown_timeout = 0ms; if (!SHUTDOWN_ZERO_TIMEOUT) { constexpr unsigned int shutdown_timeout_default = 6; constexpr unsigned int max_thermal_shutdown_timeout = 3; auto shutdown_timeout_final = android::base::GetUintProperty("ro.build.shutdown_timeout", shutdown_timeout_default); if (is_thermal_shutdown && shutdown_timeout_final > max_thermal_shutdown_timeout) { shutdown_timeout_final = max_thermal_shutdown_timeout; } shutdown_timeout = std::chrono::seconds(shutdown_timeout_final); } LOG(INFO) << "Shutdown timeout: " << shutdown_timeout.count() << " ms"; sem_t reboot_semaphore; if (sem_init(&reboot_semaphore, false, 0) == -1) { // These should never fail, but if they do, skip the graceful reboot and reboot immediately. LOG(ERROR) << "sem_init() fail and RebootSystem() return!"; RebootSystem(cmd, rebootTarget); } // Start a thread to monitor init shutdown process LOG(INFO) << "Create reboot monitor thread."; bool reboot_monitor_run = true; std::thread reboot_monitor_thread(&RebootMonitorThread, cmd, rebootTarget, &reboot_semaphore, shutdown_timeout, &reboot_monitor_run); reboot_monitor_thread.detach(); // Start reboot monitor thread sem_post(&reboot_semaphore); // keep debugging tools until non critical ones are all gone. const std::set kill_after_apps{"tombstoned", "logd", "adbd"}; // watchdogd is a vendor specific component but should be alive to complete shutdown safely. const std::set to_starts{"watchdogd"}; for (const auto& s : ServiceList::GetInstance()) { if (kill_after_apps.count(s->name())) { s->SetShutdownCritical(); } else if (to_starts.count(s->name())) { if (auto result = s->Start(); !result) { LOG(ERROR) << "Could not start shutdown 'to_start' service '" << s->name() << "': " << result.error(); } s->SetShutdownCritical(); } else if (s->IsShutdownCritical()) { // Start shutdown critical service if not started. if (auto result = s->Start(); !result) { LOG(ERROR) << "Could not start shutdown critical service '" << s->name() << "': " << result.error(); } } } // remaining operations (specifically fsck) may take a substantial duration if (cmd == ANDROID_RB_POWEROFF || is_thermal_shutdown) { TurnOffBacklight(); } Service* bootAnim = ServiceList::GetInstance().FindService("bootanim"); Service* surfaceFlinger = ServiceList::GetInstance().FindService("surfaceflinger"); if (bootAnim != nullptr && surfaceFlinger != nullptr && surfaceFlinger->IsRunning()) { bool do_shutdown_animation = GetBoolProperty("ro.init.shutdown_animation", false); if (do_shutdown_animation) { property_set("service.bootanim.exit", "0"); // Could be in the middle of animation. Stop and start so that it can pick // up the right mode. bootAnim->Stop(); } for (const auto& service : ServiceList::GetInstance()) { if (service->classnames().count("animation") == 0) { continue; } // start all animation classes if stopped. if (do_shutdown_animation) { service->Start(); } service->SetShutdownCritical(); // will not check animation class separately } if (do_shutdown_animation) { bootAnim->Start(); surfaceFlinger->SetShutdownCritical(); bootAnim->SetShutdownCritical(); } } // optional shutdown step // 1. terminate all services except shutdown critical ones. wait for delay to finish if (shutdown_timeout > 0ms) { LOG(INFO) << "terminating init services"; // Ask all services to terminate except shutdown critical ones. for (const auto& s : ServiceList::GetInstance().services_in_shutdown_order()) { if (!s->IsShutdownCritical()) s->Terminate(); } int service_count = 0; // Only wait up to half of timeout here auto termination_wait_timeout = shutdown_timeout / 2; while (t.duration() < termination_wait_timeout) { ReapAnyOutstandingChildren(); service_count = 0; for (const auto& s : ServiceList::GetInstance()) { // Count the number of services running except shutdown critical. // Exclude the console as it will ignore the SIGTERM signal // and not exit. // Note: SVC_CONSOLE actually means "requires console" but // it is only used by the shell. if (!s->IsShutdownCritical() && s->pid() != 0 && (s->flags() & SVC_CONSOLE) == 0) { service_count++; } } if (service_count == 0) { // All terminable services terminated. We can exit early. break; } // Wait a bit before recounting the number or running services. std::this_thread::sleep_for(50ms); } LOG(INFO) << "Terminating running services took " << t << " with remaining services:" << service_count; } // minimum safety steps before restarting // 2. kill all services except ones that are necessary for the shutdown sequence. for (const auto& s : ServiceList::GetInstance().services_in_shutdown_order()) { if (!s->IsShutdownCritical()) s->Stop(); } SubcontextTerminate(); ReapAnyOutstandingChildren(); // 3. send volume shutdown to vold Service* voldService = ServiceList::GetInstance().FindService("vold"); if (voldService != nullptr && voldService->IsRunning()) { ShutdownVold(); voldService->Stop(); } else { LOG(INFO) << "vold not running, skipping vold shutdown"; } // logcat stopped here for (const auto& s : ServiceList::GetInstance().services_in_shutdown_order()) { if (kill_after_apps.count(s->name())) s->Stop(); } // 4. sync, try umount, and optionally run fsck for user shutdown { Timer sync_timer; LOG(INFO) << "sync() before umount..."; sync(); LOG(INFO) << "sync() before umount took" << sync_timer; } // 5. drop caches and disable zram backing device, if exist KillZramBackingDevice(); UmountStat stat = TryUmountAndFsck(cmd, rebootTarget, runFsck, shutdown_timeout - t.duration(), &reboot_semaphore); // Follow what linux shutdown is doing: one more sync with little bit delay { Timer sync_timer; LOG(INFO) << "sync() after umount..."; sync(); LOG(INFO) << "sync() after umount took" << sync_timer; } if (!is_thermal_shutdown) std::this_thread::sleep_for(100ms); LogShutdownTime(stat, &t); // Send signal to terminate reboot monitor thread. reboot_monitor_run = false; sem_post(&reboot_semaphore); // Reboot regardless of umount status. If umount fails, fsck after reboot will fix it. RebootSystem(cmd, rebootTarget); abort(); } bool HandlePowerctlMessage(const std::string& command) { unsigned int cmd = 0; std::vector cmd_params = Split(command, ","); std::string reboot_target = ""; bool run_fsck = false; bool command_invalid = false; if (cmd_params[0] == "shutdown") { cmd = ANDROID_RB_POWEROFF; if (cmd_params.size() >= 2) { if (cmd_params[1] == "userrequested") { // The shutdown reason is PowerManager.SHUTDOWN_USER_REQUESTED. // Run fsck once the file system is remounted in read-only mode. run_fsck = true; } else if (cmd_params[1] == "thermal") { // Turn off sources of heat immediately. TurnOffBacklight(); // run_fsck is false to avoid delay cmd = ANDROID_RB_THERMOFF; } } } else if (cmd_params[0] == "reboot") { cmd = ANDROID_RB_RESTART2; if (cmd_params.size() >= 2) { reboot_target = cmd_params[1]; // adb reboot fastboot should boot into bootloader for devices not // supporting logical partitions. if (reboot_target == "fastboot" && !android::base::GetBoolProperty("ro.boot.dynamic_partitions", false)) { reboot_target = "bootloader"; } // When rebooting to the bootloader notify the bootloader writing // also the BCB. if (reboot_target == "bootloader") { std::string err; if (!write_reboot_bootloader(&err)) { LOG(ERROR) << "reboot-bootloader: Error writing " "bootloader_message: " << err; } } else if (reboot_target == "recovery") { bootloader_message boot = {}; if (std::string err; !read_bootloader_message(&boot, &err)) { LOG(ERROR) << "Failed to read bootloader message: " << err; } // Update the boot command field if it's empty, and preserve // the other arguments in the bootloader message. if (boot.command[0] == '\0') { strlcpy(boot.command, "boot-recovery", sizeof(boot.command)); if (std::string err; !write_bootloader_message(boot, &err)) { LOG(ERROR) << "Failed to set bootloader message: " << err; return false; } } } else if (reboot_target == "sideload" || reboot_target == "sideload-auto-reboot" || reboot_target == "fastboot") { std::string arg = reboot_target == "sideload-auto-reboot" ? "sideload_auto_reboot" : reboot_target; const std::vector options = { "--" + arg, }; std::string err; if (!write_bootloader_message(options, &err)) { LOG(ERROR) << "Failed to set bootloader message: " << err; return false; } reboot_target = "recovery"; } // If there are additional parameter, pass them along for (size_t i = 2; (cmd_params.size() > i) && cmd_params[i].size(); ++i) { reboot_target += "," + cmd_params[i]; } } } else { command_invalid = true; } if (command_invalid) { LOG(ERROR) << "powerctl: unrecognized command '" << command << "'"; return false; } LOG(INFO) << "Clear action queue and start shutdown trigger"; ActionManager::GetInstance().ClearQueue(); // Queue shutdown trigger first ActionManager::GetInstance().QueueEventTrigger("shutdown"); // Queue built-in shutdown_done auto shutdown_handler = [cmd, command, reboot_target, run_fsck](const BuiltinArguments&) { DoReboot(cmd, command, reboot_target, run_fsck); return Result{}; }; ActionManager::GetInstance().QueueBuiltinAction(shutdown_handler, "shutdown_done"); // Skip wait for prop if it is in progress ResetWaitForProp(); // Clear EXEC flag if there is one pending for (const auto& s : ServiceList::GetInstance()) { s->UnSetExec(); } return true; } } // namespace init } // namespace android