| /* | 
 |  * 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 <dirent.h> | 
 | #include <fcntl.h> | 
 | #include <linux/f2fs.h> | 
 | #include <linux/fs.h> | 
 | #include <linux/loop.h> | 
 | #include <mntent.h> | 
 | #include <semaphore.h> | 
 | #include <stdlib.h> | 
 | #include <sys/cdefs.h> | 
 | #include <sys/ioctl.h> | 
 | #include <sys/mount.h> | 
 | #include <sys/stat.h> | 
 | #include <sys/swap.h> | 
 | #include <sys/syscall.h> | 
 | #include <sys/types.h> | 
 | #include <sys/wait.h> | 
 |  | 
 | #include <chrono> | 
 | #include <memory> | 
 | #include <set> | 
 | #include <thread> | 
 | #include <vector> | 
 |  | 
 | #include <InitProperties.sysprop.h> | 
 | #include <android-base/chrono_utils.h> | 
 | #include <android-base/file.h> | 
 | #include <android-base/logging.h> | 
 | #include <android-base/macros.h> | 
 | #include <android-base/properties.h> | 
 | #include <android-base/scopeguard.h> | 
 | #include <android-base/strings.h> | 
 | #include <android-base/unique_fd.h> | 
 | #include <bootloader_message/bootloader_message.h> | 
 | #include <cutils/android_reboot.h> | 
 | #include <fs_mgr.h> | 
 | #include <libsnapshot/snapshot.h> | 
 | #include <logwrap/logwrap.h> | 
 | #include <private/android_filesystem_config.h> | 
 | #include <selinux/selinux.h> | 
 |  | 
 | #include "action.h" | 
 | #include "action_manager.h" | 
 | #include "builtin_arguments.h" | 
 | #include "init.h" | 
 | #include "mount_namespace.h" | 
 | #include "property_service.h" | 
 | #include "reboot_utils.h" | 
 | #include "service.h" | 
 | #include "service_list.h" | 
 | #include "sigchld_handler.h" | 
 | #include "util.h" | 
 |  | 
 | using namespace std::literals; | 
 |  | 
 | using android::base::boot_clock; | 
 | using android::base::GetBoolProperty; | 
 | using android::base::GetUintProperty; | 
 | using android::base::SetProperty; | 
 | using android::base::Split; | 
 | using android::base::Timer; | 
 | using android::base::unique_fd; | 
 | using android::base::WaitForProperty; | 
 | using android::base::WriteStringToFile; | 
 |  | 
 | namespace android { | 
 | namespace init { | 
 |  | 
 | static bool shutting_down = false; | 
 |  | 
 | static const std::set<std::string> kDebuggingServices{"tombstoned", "logd", "adbd", "console"}; | 
 |  | 
 | static std::set<std::string> GetPostDataDebuggingServices() { | 
 |     std::set<std::string> ret; | 
 |     for (const auto& s : ServiceList::GetInstance()) { | 
 |         if (kDebuggingServices.count(s->name()) && s->is_post_data()) { | 
 |             ret.insert(s->name()); | 
 |         } | 
 |     } | 
 |     return ret; | 
 | } | 
 |  | 
 | static void PersistRebootReason(const char* reason, bool write_to_property) { | 
 |     if (write_to_property) { | 
 |         SetProperty(LAST_REBOOT_REASON_PROPERTY, reason); | 
 |     } | 
 |     auto fd = unique_fd(TEMP_FAILURE_RETRY(open( | 
 |             LAST_REBOOT_REASON_FILE, O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC | O_BINARY, 0666))); | 
 |     if (!fd.ok()) { | 
 |         PLOG(ERROR) << "Could not open '" << LAST_REBOOT_REASON_FILE | 
 |                     << "' to persist reboot reason"; | 
 |         return; | 
 |     } | 
 |     WriteStringToFd(reason, fd); | 
 |     fsync(fd.get()); | 
 | } | 
 |  | 
 | // 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(), | 
 |             }; | 
 |             logwrap_fork_execvp(arraysize(f2fs_argv), f2fs_argv, &st, false, LOG_KLOG, true, | 
 |                                 nullptr); | 
 |         } else if (IsExt4()) { | 
 |             const char* ext4_argv[] = { | 
 |                     "/system/bin/e2fsck", | 
 |                     "-y", | 
 |                     mnt_fsname_.c_str(), | 
 |             }; | 
 |             logwrap_fork_execvp(arraysize(ext4_argv), ext4_argv, &st, false, LOG_KLOG, true, | 
 |                                 nullptr); | 
 |         } | 
 |     } | 
 |  | 
 |     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.ok()) { | 
 |         LOG(WARNING) << "Could not start blank_screen service: " << result.error(); | 
 |     } | 
 | } | 
 |  | 
 | static Result<void> CallVdc(const std::string& system, const std::string& cmd) { | 
 |     LOG(INFO) << "Calling /system/bin/vdc " << system << " " << cmd; | 
 |     const char* vdc_argv[] = {"/system/bin/vdc", system.c_str(), cmd.c_str()}; | 
 |     int status; | 
 |     if (logwrap_fork_execvp(arraysize(vdc_argv), vdc_argv, &status, false, LOG_KLOG, true, | 
 |                             nullptr) != 0) { | 
 |         return ErrnoError() << "Failed to call '/system/bin/vdc " << system << " " << cmd << "'"; | 
 |     } | 
 |     if (WIFEXITED(status) && WEXITSTATUS(status) == 0) { | 
 |         return {}; | 
 |     } | 
 |     return Error() << "'/system/bin/vdc " << system << " " << cmd << "' failed : " << status; | 
 | } | 
 |  | 
 | static void LogShutdownTime(UmountStat stat, Timer* t) { | 
 |     LOG(WARNING) << "powerctl_shutdown_time_ms:" << std::to_string(t->duration().count()) << ":" | 
 |                  << stat; | 
 | } | 
 |  | 
 | static bool IsDataMounted(const std::string& fstype) { | 
 |     std::unique_ptr<std::FILE, int (*)(std::FILE*)> 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 (mentry->mnt_dir == "/data"s) { | 
 |             return fstype == "*" || mentry->mnt_type == fstype; | 
 |         } | 
 |     } | 
 |     return false; | 
 | } | 
 |  | 
 | // Find all read+write block devices and emulated devices in /proc/mounts and add them to | 
 | // the correpsponding list. | 
 | static bool FindPartitionsToUmount(std::vector<MountEntry>* block_dev_partitions, | 
 |                                    std::vector<MountEntry>* emulated_partitions, bool dump) { | 
 |     std::unique_ptr<std::FILE, int (*)(std::FILE*)> 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") { | 
 |                 block_dev_partitions->emplace(block_dev_partitions->begin(), *mentry); | 
 |             } | 
 |         } else if (MountEntry::IsEmulatedDevice(*mentry)) { | 
 |             emulated_partitions->emplace(emulated_partitions->begin(), *mentry); | 
 |         } | 
 |     } | 
 |     return true; | 
 | } | 
 |  | 
 | static void DumpUmountDebuggingInfo() { | 
 |     int status; | 
 |     if (!security_getenforce()) { | 
 |         LOG(INFO) << "Run lsof"; | 
 |         const char* lsof_argv[] = {"/system/bin/lsof"}; | 
 |         logwrap_fork_execvp(arraysize(lsof_argv), lsof_argv, &status, false, LOG_KLOG, true, | 
 |                             nullptr); | 
 |     } | 
 |     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<MountEntry> block_devices; | 
 |         std::vector<MountEntry> 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& reboot_target, | 
 |                          sem_t* reboot_semaphore, std::chrono::milliseconds shutdown_timeout, | 
 |                          bool* reboot_monitor_run) { | 
 |     unsigned int remaining_shutdown_time = 0; | 
 |  | 
 |     // 300 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 = 300; | 
 |     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) { | 
 |                 if (false) { | 
 |                     // SEPolicy will block debuggerd from running and this is intentional. | 
 |                     // But these lines are left to be enabled during debugging. | 
 |                     LOG(INFO) << "Try to dump init process call trace:"; | 
 |                     const char* vdc_argv[] = {"/system/bin/debuggerd", "-b", "1"}; | 
 |                     int status; | 
 |                     logwrap_fork_execvp(arraysize(vdc_argv), vdc_argv, &status, false, LOG_KLOG, | 
 |                                         true, nullptr); | 
 |                 } | 
 |                 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, reboot_target); | 
 |             } | 
 |  | 
 |             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, bool run_fsck, | 
 |                                    std::chrono::milliseconds timeout, sem_t* reboot_semaphore) { | 
 |     Timer t; | 
 |     std::vector<MountEntry> block_devices; | 
 |     std::vector<MountEntry> emulated_devices; | 
 |  | 
 |     if (run_fsck && !FindPartitionsToUmount(&block_devices, &emulated_devices, false)) { | 
 |         return UMOUNT_STAT_ERROR; | 
 |     } | 
 |     auto sm = snapshot::SnapshotManager::New(); | 
 |     bool ota_update_in_progress = false; | 
 |     if (sm->IsUserspaceSnapshotUpdateInProgress()) { | 
 |         LOG(INFO) << "OTA update in progress"; | 
 |         ota_update_in_progress = true; | 
 |     } | 
 |     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(); | 
 |         // Since umount timedout, we will try to kill all processes | 
 |         // and do one more attempt to umount the partitions. | 
 |         // | 
 |         // However, if OTA update is in progress, we don't want | 
 |         // to kill the snapuserd daemon as the daemon will | 
 |         // be serving I/O requests. Killing the daemon will | 
 |         // end up with I/O failures. If the update is in progress, | 
 |         // we will just return the umount failure status immediately. | 
 |         // This is ok, given the fact that killing the processes | 
 |         // and doing an umount is just a last effort. We are | 
 |         // still not doing fsck when all processes are killed. | 
 |         // | 
 |         if (ota_update_in_progress) { | 
 |             return stat; | 
 |         } | 
 |         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 && run_fsck) { | 
 |         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" | 
 | #define ZRAM_INITSTATE    "/sys/block/zram0/initstate" | 
 | static Result<void> KillZramBackingDevice() { | 
 |     std::string zram_initstate; | 
 |     if (!android::base::ReadFileToString(ZRAM_INITSTATE, &zram_initstate)) { | 
 |         return ErrnoError() << "Failed to read " << ZRAM_INITSTATE; | 
 |     } | 
 |  | 
 |     zram_initstate.erase(zram_initstate.length() - 1); | 
 |     if (zram_initstate == "0") { | 
 |         LOG(INFO) << "Zram has not been swapped on"; | 
 |         return {}; | 
 |     } | 
 |  | 
 |     if (access(ZRAM_BACK_DEV, F_OK) != 0 && errno == ENOENT) { | 
 |         LOG(INFO) << "No zram backing device configured"; | 
 |         return {}; | 
 |     } | 
 |     std::string backing_dev; | 
 |     if (!android::base::ReadFileToString(ZRAM_BACK_DEV, &backing_dev)) { | 
 |         return ErrnoError() << "Failed to read " << ZRAM_BACK_DEV; | 
 |     } | 
 |  | 
 |     // cut the last "\n" | 
 |     backing_dev.erase(backing_dev.length() - 1); | 
 |  | 
 |     if (android::base::StartsWith(backing_dev, "none")) { | 
 |         LOG(INFO) << "No zram backing device configured"; | 
 |         return {}; | 
 |     } | 
 |  | 
 |     // shutdown zram handle | 
 |     Timer swap_timer; | 
 |     LOG(INFO) << "swapoff() start..."; | 
 |     if (swapoff(ZRAM_DEVICE) == -1) { | 
 |         return ErrnoError() << "zram_backing_dev: swapoff (" << backing_dev << ")" | 
 |                             << " failed"; | 
 |     } | 
 |     LOG(INFO) << "swapoff() took " << swap_timer; | 
 |  | 
 |     if (!WriteStringToFile("1", ZRAM_RESET)) { | 
 |         return Error() << "zram_backing_dev: reset (" << backing_dev << ")" | 
 |                        << " failed"; | 
 |     } | 
 |  | 
 |     if (!android::base::StartsWith(backing_dev, "/dev/block/loop")) { | 
 |         LOG(INFO) << backing_dev << " is not a loop device. Exiting early"; | 
 |         return {}; | 
 |     } | 
 |  | 
 |     // clear loopback device | 
 |     unique_fd loop(TEMP_FAILURE_RETRY(open(backing_dev.c_str(), O_RDWR | O_CLOEXEC))); | 
 |     if (loop.get() < 0) { | 
 |         return ErrnoError() << "zram_backing_dev: open(" << backing_dev << ")" | 
 |                             << " failed"; | 
 |     } | 
 |  | 
 |     if (ioctl(loop.get(), LOOP_CLR_FD, 0) < 0) { | 
 |         return ErrnoError() << "zram_backing_dev: loop_clear (" << backing_dev << ")" | 
 |                             << " failed"; | 
 |     } | 
 |     LOG(INFO) << "zram_backing_dev: `" << backing_dev << "` is cleared successfully."; | 
 |     return {}; | 
 | } | 
 |  | 
 | // Stops given services, waits for them to be stopped for |timeout| ms. | 
 | // If terminate is true, then SIGTERM is sent to services, otherwise SIGKILL is sent. | 
 | // Note that services are stopped in order given by |ServiceList::services_in_shutdown_order| | 
 | // function. | 
 | static void StopServices(const std::set<std::string>& services, std::chrono::milliseconds timeout, | 
 |                          bool terminate) { | 
 |     LOG(INFO) << "Stopping " << services.size() << " services by sending " | 
 |               << (terminate ? "SIGTERM" : "SIGKILL"); | 
 |     std::vector<pid_t> pids; | 
 |     pids.reserve(services.size()); | 
 |     for (const auto& s : ServiceList::GetInstance().services_in_shutdown_order()) { | 
 |         if (services.count(s->name()) == 0) { | 
 |             continue; | 
 |         } | 
 |         if (s->pid() > 0) { | 
 |             pids.push_back(s->pid()); | 
 |         } | 
 |         if (terminate) { | 
 |             s->Terminate(); | 
 |         } else { | 
 |             s->Stop(); | 
 |         } | 
 |     } | 
 |     if (timeout > 0ms) { | 
 |         WaitToBeReaped(pids, timeout); | 
 |     } else { | 
 |         // Even if we don't to wait for services to stop, we still optimistically reap zombies. | 
 |         ReapAnyOutstandingChildren(); | 
 |     } | 
 | } | 
 |  | 
 | // Like StopServices, but also logs all the services that failed to stop after the provided timeout. | 
 | // Returns number of violators. | 
 | int StopServicesAndLogViolations(const std::set<std::string>& services, | 
 |                                  std::chrono::milliseconds timeout, bool terminate) { | 
 |     StopServices(services, timeout, terminate); | 
 |     int still_running = 0; | 
 |     for (const auto& s : ServiceList::GetInstance()) { | 
 |         if (s->IsRunning() && services.count(s->name())) { | 
 |             LOG(ERROR) << "[service-misbehaving] : service '" << s->name() << "' is still running " | 
 |                        << timeout.count() << "ms after receiving " | 
 |                        << (terminate ? "SIGTERM" : "SIGKILL"); | 
 |             still_running++; | 
 |         } | 
 |     } | 
 |     return still_running; | 
 | } | 
 |  | 
 | static Result<void> UnmountAllApexes() { | 
 |     // don't need to unmount because apexd doesn't use /data in Microdroid | 
 |     if (IsMicrodroid()) { | 
 |         return {}; | 
 |     } | 
 |  | 
 |     const char* args[] = {"/system/bin/apexd", "--unmount-all"}; | 
 |     int status; | 
 |     if (logwrap_fork_execvp(arraysize(args), args, &status, false, LOG_KLOG, true, nullptr) != 0) { | 
 |         return ErrnoError() << "Failed to call '/system/bin/apexd --unmount-all'"; | 
 |     } | 
 |     if (WIFEXITED(status) && WEXITSTATUS(status) == 0) { | 
 |         return {}; | 
 |     } | 
 |     return Error() << "'/system/bin/apexd --unmount-all' failed : " << status; | 
 | } | 
 |  | 
 | //* Reboot / shutdown the system. | 
 | // cmd ANDROID_RB_* as defined in android_reboot.h | 
 | // reason Reason string like "reboot", "shutdown,userrequested" | 
 | // reboot_target Reboot target string like "bootloader". Otherwise, it should be an empty string. | 
 | // run_fsck Whether to run fsck after umount is done. | 
 | // | 
 | static void DoReboot(unsigned int cmd, const std::string& reason, const std::string& reboot_target, | 
 |                      bool run_fsck) { | 
 |     Timer t; | 
 |     LOG(INFO) << "Reboot start, reason: " << reason << ", reboot_target: " << reboot_target; | 
 |  | 
 |     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, reboot_target, reason); | 
 |     } | 
 |  | 
 |     // 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, reboot_target, &reboot_semaphore, | 
 |                                       shutdown_timeout, &reboot_monitor_run); | 
 |     reboot_monitor_thread.detach(); | 
 |  | 
 |     // Start reboot monitor thread | 
 |     sem_post(&reboot_semaphore); | 
 |  | 
 |     // Ensure last reboot reason is reduced to canonical | 
 |     // alias reported in bootloader or system boot reason. | 
 |     size_t skip = 0; | 
 |     std::vector<std::string> 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,"); | 
 |     } | 
 |     PersistRebootReason(reason.c_str() + skip, true); | 
 |  | 
 |     // If /data isn't mounted then we can skip the extra reboot steps below, since we don't need to | 
 |     // worry about unmounting it. | 
 |     if (!IsDataMounted("*")) { | 
 |         sync(); | 
 |         RebootSystem(cmd, reboot_target, reason); | 
 |         abort(); | 
 |     } | 
 |  | 
 |     bool do_shutdown_animation = GetBoolProperty("ro.init.shutdown_animation", false); | 
 |     // watchdogd is a vendor specific component but should be alive to complete shutdown safely. | 
 |     const std::set<std::string> to_starts{"watchdogd"}; | 
 |     std::set<std::string> stop_first; | 
 |     for (const auto& s : ServiceList::GetInstance()) { | 
 |         if (kDebuggingServices.count(s->name())) { | 
 |             // keep debugging tools until non critical ones are all gone. | 
 |             s->SetShutdownCritical(); | 
 |         } else if (to_starts.count(s->name())) { | 
 |             if (auto result = s->Start(); !result.ok()) { | 
 |                 LOG(ERROR) << "Could not start shutdown 'to_start' service '" << s->name() | 
 |                            << "': " << result.error(); | 
 |             } | 
 |             s->SetShutdownCritical(); | 
 |         } else if (do_shutdown_animation && s->classnames().count("animation") > 0) { | 
 |             // Need these for shutdown animations. | 
 |         } else if (s->IsShutdownCritical()) { | 
 |             // Start shutdown critical service if not started. | 
 |             if (auto result = s->Start(); !result.ok()) { | 
 |                 LOG(ERROR) << "Could not start shutdown critical service '" << s->name() | 
 |                            << "': " << result.error(); | 
 |             } | 
 |         } else { | 
 |             stop_first.insert(s->name()); | 
 |         } | 
 |     } | 
 |  | 
 |     // remaining operations (specifically fsck) may take a substantial duration | 
 |     if (!do_shutdown_animation && (cmd == ANDROID_RB_POWEROFF || is_thermal_shutdown)) { | 
 |         TurnOffBacklight(); | 
 |     } | 
 |  | 
 |     Service* boot_anim = ServiceList::GetInstance().FindService("bootanim"); | 
 |     Service* surface_flinger = ServiceList::GetInstance().FindService("surfaceflinger"); | 
 |     if (boot_anim != nullptr && surface_flinger != nullptr && surface_flinger->IsRunning()) { | 
 |  | 
 |         if (do_shutdown_animation) { | 
 |             SetProperty("service.bootanim.exit", "0"); | 
 |             SetProperty("service.bootanim.progress", "0"); | 
 |             // Could be in the middle of animation. Stop and start so that it can pick | 
 |             // up the right mode. | 
 |             boot_anim->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) { | 
 |             boot_anim->Start(); | 
 |             surface_flinger->SetShutdownCritical(); | 
 |             boot_anim->SetShutdownCritical(); | 
 |         } | 
 |     } | 
 |  | 
 |     // optional shutdown step | 
 |     // 1. terminate all services except shutdown critical ones. wait for delay to finish | 
 |     if (shutdown_timeout > 0ms) { | 
 |         StopServicesAndLogViolations(stop_first, shutdown_timeout / 2, true /* SIGTERM */); | 
 |     } | 
 |     // Send SIGKILL to ones that didn't terminate cleanly. | 
 |     StopServicesAndLogViolations(stop_first, 0ms, false /* SIGKILL */); | 
 |     SubcontextTerminate(); | 
 |     // Reap subcontext pids. | 
 |     ReapAnyOutstandingChildren(); | 
 |  | 
 |     // 3. send volume abort_fuse and volume shutdown to vold | 
 |     Service* vold_service = ServiceList::GetInstance().FindService("vold"); | 
 |     if (vold_service != nullptr && vold_service->IsRunning()) { | 
 |         // Manually abort FUSE connections, since the FUSE daemon is already dead | 
 |         // at this point, and unmounting it might hang. | 
 |         CallVdc("volume", "abort_fuse"); | 
 |         CallVdc("volume", "shutdown"); | 
 |         vold_service->Stop(); | 
 |     } else { | 
 |         LOG(INFO) << "vold not running, skipping vold shutdown"; | 
 |     } | 
 |     // logcat stopped here | 
 |     StopServices(kDebuggingServices, 0ms, false /* SIGKILL */); | 
 |     // 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(); | 
 |  | 
 |     LOG(INFO) << "Ready to unmount apexes. So far shutdown sequence took " << t; | 
 |     // 6. unmount active apexes, otherwise they might prevent clean unmount of /data. | 
 |     if (auto ret = UnmountAllApexes(); !ret.ok()) { | 
 |         LOG(ERROR) << ret.error(); | 
 |     } | 
 |     UmountStat stat = | 
 |             TryUmountAndFsck(cmd, run_fsck, 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. | 
 |     if (IsDataMounted("f2fs")) { | 
 |         uint32_t flag = F2FS_GOING_DOWN_FULLSYNC; | 
 |         unique_fd fd(TEMP_FAILURE_RETRY(open("/data", O_RDONLY))); | 
 |         int ret = ioctl(fd.get(), F2FS_IOC_SHUTDOWN, &flag); | 
 |         if (ret) { | 
 |             PLOG(ERROR) << "Shutdown /data: "; | 
 |         } else { | 
 |             LOG(INFO) << "Shutdown /data"; | 
 |         } | 
 |     } | 
 |     RebootSystem(cmd, reboot_target, reason); | 
 |     abort(); | 
 | } | 
 |  | 
 | static void EnterShutdown() { | 
 |     LOG(INFO) << "Entering shutdown mode"; | 
 |     shutting_down = true; | 
 |     // 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(); | 
 |     } | 
 | } | 
 |  | 
 | static void LeaveShutdown() { | 
 |     LOG(INFO) << "Leaving shutdown mode"; | 
 |     shutting_down = false; | 
 |     StartSendingMessages(); | 
 | } | 
 |  | 
 | static std::chrono::milliseconds GetMillisProperty(const std::string& name, | 
 |                                                    std::chrono::milliseconds default_value) { | 
 |     auto value = GetUintProperty(name, static_cast<uint64_t>(default_value.count())); | 
 |     return std::chrono::milliseconds(std::move(value)); | 
 | } | 
 |  | 
 | static Result<void> DoUserspaceReboot() { | 
 |     LOG(INFO) << "Userspace reboot initiated"; | 
 |     // An ugly way to pass a more precise reason on why fallback to hard reboot was triggered. | 
 |     std::string sub_reason = ""; | 
 |     auto guard = android::base::make_scope_guard([&sub_reason] { | 
 |         // Leave shutdown so that we can handle a full reboot. | 
 |         LeaveShutdown(); | 
 |         trigger_shutdown("reboot,userspace_failed,shutdown_aborted," + sub_reason); | 
 |     }); | 
 |     // Triggering userspace-reboot-requested will result in a bunch of setprop | 
 |     // actions. We should make sure, that all of them are propagated before | 
 |     // proceeding with userspace reboot. Synchronously setting sys.init.userspace_reboot.in_progress | 
 |     // property is not perfect, but it should do the trick. | 
 |     if (!android::sysprop::InitProperties::userspace_reboot_in_progress(true)) { | 
 |         sub_reason = "setprop"; | 
 |         return Error() << "Failed to set sys.init.userspace_reboot.in_progress property"; | 
 |     } | 
 |     EnterShutdown(); | 
 |     if (!SetProperty("sys.powerctl", "")) { | 
 |         sub_reason = "resetprop"; | 
 |         return Error() << "Failed to reset sys.powerctl property"; | 
 |     } | 
 |     std::set<std::string> stop_first; | 
 |     // Remember the services that were enabled. We will need to manually enable them again otherwise | 
 |     // triggers like class_start won't restart them. | 
 |     std::set<std::string> were_enabled; | 
 |     for (const auto& s : ServiceList::GetInstance().services_in_shutdown_order()) { | 
 |         if (s->is_post_data() && !kDebuggingServices.count(s->name())) { | 
 |             stop_first.insert(s->name()); | 
 |         } | 
 |         // TODO(ioffe): we should also filter out temporary services here. | 
 |         if (s->is_post_data() && s->IsEnabled()) { | 
 |             were_enabled.insert(s->name()); | 
 |         } | 
 |     } | 
 |     { | 
 |         Timer sync_timer; | 
 |         LOG(INFO) << "sync() before terminating services..."; | 
 |         sync(); | 
 |         LOG(INFO) << "sync() took " << sync_timer; | 
 |     } | 
 |     auto sigterm_timeout = GetMillisProperty("init.userspace_reboot.sigterm.timeoutmillis", 5s); | 
 |     auto sigkill_timeout = GetMillisProperty("init.userspace_reboot.sigkill.timeoutmillis", 10s); | 
 |     LOG(INFO) << "Timeout to terminate services: " << sigterm_timeout.count() << "ms " | 
 |               << "Timeout to kill services: " << sigkill_timeout.count() << "ms"; | 
 |     std::string services_file_name = "/metadata/userspacereboot/services.txt"; | 
 |     const int flags = O_RDWR | O_CREAT | O_SYNC | O_APPEND | O_CLOEXEC; | 
 |     StopServicesAndLogViolations(stop_first, sigterm_timeout, true /* SIGTERM */); | 
 |     if (int r = StopServicesAndLogViolations(stop_first, sigkill_timeout, false /* SIGKILL */); | 
 |         r > 0) { | 
 |         auto fd = unique_fd(TEMP_FAILURE_RETRY(open(services_file_name.c_str(), flags, 0666))); | 
 |         android::base::WriteStringToFd("Post-data services still running: \n", fd); | 
 |         for (const auto& s : ServiceList::GetInstance()) { | 
 |             if (s->IsRunning() && stop_first.count(s->name())) { | 
 |                 android::base::WriteStringToFd(s->name() + "\n", fd); | 
 |             } | 
 |         } | 
 |         sub_reason = "sigkill"; | 
 |         return Error() << r << " post-data services are still running"; | 
 |     } | 
 |     if (auto result = KillZramBackingDevice(); !result.ok()) { | 
 |         sub_reason = "zram"; | 
 |         return result; | 
 |     } | 
 |     if (auto result = CallVdc("volume", "reset"); !result.ok()) { | 
 |         sub_reason = "vold_reset"; | 
 |         return result; | 
 |     } | 
 |     const auto& debugging_services = GetPostDataDebuggingServices(); | 
 |     if (int r = StopServicesAndLogViolations(debugging_services, sigkill_timeout, | 
 |                                              false /* SIGKILL */); | 
 |         r > 0) { | 
 |         auto fd = unique_fd(TEMP_FAILURE_RETRY(open(services_file_name.c_str(), flags, 0666))); | 
 |         android::base::WriteStringToFd("Debugging services still running: \n", fd); | 
 |         for (const auto& s : ServiceList::GetInstance()) { | 
 |             if (s->IsRunning() && debugging_services.count(s->name())) { | 
 |                 android::base::WriteStringToFd(s->name() + "\n", fd); | 
 |             } | 
 |         } | 
 |         sub_reason = "sigkill_debug"; | 
 |         return Error() << r << " debugging services are still running"; | 
 |     } | 
 |     { | 
 |         Timer sync_timer; | 
 |         LOG(INFO) << "sync() after stopping services..."; | 
 |         sync(); | 
 |         LOG(INFO) << "sync() took " << sync_timer; | 
 |     } | 
 |     if (auto result = UnmountAllApexes(); !result.ok()) { | 
 |         sub_reason = "apex"; | 
 |         return result; | 
 |     } | 
 |     if (!SwitchToMountNamespaceIfNeeded(NS_BOOTSTRAP).ok()) { | 
 |         sub_reason = "ns_switch"; | 
 |         return Error() << "Failed to switch to bootstrap namespace"; | 
 |     } | 
 |     ActionManager::GetInstance().RemoveActionIf([](const auto& action) -> bool { | 
 |         if (action->IsFromApex()) { | 
 |             std::string trigger_name = action->BuildTriggersString(); | 
 |             LOG(INFO) << "Removing action (" << trigger_name << ") from (" << action->filename() | 
 |                       << ":" << action->line() << ")"; | 
 |             return true; | 
 |         } | 
 |         return false; | 
 |     }); | 
 |     // Remove services that were defined in an APEX | 
 |     ServiceList::GetInstance().RemoveServiceIf([](const std::unique_ptr<Service>& s) -> bool { | 
 |         if (s->is_from_apex()) { | 
 |             LOG(INFO) << "Removing service '" << s->name() << "' because it's defined in an APEX"; | 
 |             return true; | 
 |         } | 
 |         return false; | 
 |     }); | 
 |     // Re-enable services | 
 |     for (const auto& s : ServiceList::GetInstance()) { | 
 |         if (were_enabled.count(s->name())) { | 
 |             LOG(INFO) << "Re-enabling service '" << s->name() << "'"; | 
 |             s->Enable(); | 
 |         } | 
 |     } | 
 |     ServiceList::GetInstance().ResetState(); | 
 |     LeaveShutdown(); | 
 |     ActionManager::GetInstance().QueueEventTrigger("userspace-reboot-resume"); | 
 |     guard.Disable();  // Go on with userspace reboot. | 
 |     return {}; | 
 | } | 
 |  | 
 | static void UserspaceRebootWatchdogThread() { | 
 |     auto started_timeout = GetMillisProperty("init.userspace_reboot.started.timeoutmillis", 10s); | 
 |     if (!WaitForProperty("sys.init.userspace_reboot.in_progress", "1", started_timeout)) { | 
 |         LOG(ERROR) << "Userspace reboot didn't start in " << started_timeout.count() | 
 |                    << "ms. Switching to full reboot"; | 
 |         // Init might be wedged, don't try to write reboot reason into a persistent property and do | 
 |         // a dirty reboot. | 
 |         PersistRebootReason("userspace_failed,watchdog_triggered,failed_to_start", false); | 
 |         RebootSystem(ANDROID_RB_RESTART2, "userspace_failed,watchdog_triggered,failed_to_start"); | 
 |     } | 
 |     LOG(INFO) << "Starting userspace reboot watchdog"; | 
 |     auto watchdog_timeout = GetMillisProperty("init.userspace_reboot.watchdog.timeoutmillis", 5min); | 
 |     LOG(INFO) << "UserspaceRebootWatchdog timeout: " << watchdog_timeout.count() << "ms"; | 
 |     if (!WaitForProperty("sys.boot_completed", "1", watchdog_timeout)) { | 
 |         LOG(ERROR) << "Failed to boot in " << watchdog_timeout.count() | 
 |                    << "ms. Switching to full reboot"; | 
 |         // In this case device is in a boot loop. Only way to recover is to do dirty reboot. | 
 |         // Since init might be wedged, don't try to write reboot reason into a persistent property. | 
 |         PersistRebootReason("userspace_failed,watchdog_triggered,failed_to_boot", false); | 
 |         RebootSystem(ANDROID_RB_RESTART2, "userspace_failed,watchdog_triggered,failed_to_boot"); | 
 |     } | 
 |     LOG(INFO) << "Device booted, stopping userspace reboot watchdog"; | 
 | } | 
 |  | 
 | static void HandleUserspaceReboot() { | 
 |     if (!android::sysprop::InitProperties::is_userspace_reboot_supported().value_or(false)) { | 
 |         LOG(ERROR) << "Attempted a userspace reboot on a device that doesn't support it"; | 
 |         return; | 
 |     } | 
 |     // Spinnig up a separate thread will fail the setns call later in the boot sequence. | 
 |     // Fork a new process to monitor userspace reboot while we are investigating a better solution. | 
 |     pid_t pid = fork(); | 
 |     if (pid < 0) { | 
 |         PLOG(ERROR) << "Failed to fork process for userspace reboot watchdog. Switching to full " | 
 |                     << "reboot"; | 
 |         trigger_shutdown("reboot,userspace_failed,watchdog_fork"); | 
 |         return; | 
 |     } | 
 |     if (pid == 0) { | 
 |         // Child | 
 |         UserspaceRebootWatchdogThread(); | 
 |         _exit(EXIT_SUCCESS); | 
 |     } | 
 |     LOG(INFO) << "Clearing queue and starting userspace-reboot-requested trigger"; | 
 |     auto& am = ActionManager::GetInstance(); | 
 |     am.ClearQueue(); | 
 |     am.QueueEventTrigger("userspace-reboot-requested"); | 
 |     auto handler = [](const BuiltinArguments&) { return DoUserspaceReboot(); }; | 
 |     am.QueueBuiltinAction(handler, "userspace-reboot"); | 
 | } | 
 |  | 
 | /** | 
 |  * Check if "command" field is set in bootloader message. | 
 |  * | 
 |  * If "command" field is broken (contains non-printable characters prior to | 
 |  * terminating zero), it will be zeroed. | 
 |  * | 
 |  * @param[in,out] boot Bootloader message (BCB) structure | 
 |  * @return true if "command" field is already set, and false if it's empty | 
 |  */ | 
 | static bool CommandIsPresent(bootloader_message* boot) { | 
 |     if (boot->command[0] == '\0') | 
 |         return false; | 
 |  | 
 |     for (size_t i = 0; i < arraysize(boot->command); ++i) { | 
 |         if (boot->command[i] == '\0') | 
 |             return true; | 
 |         if (!isprint(boot->command[i])) | 
 |             break; | 
 |     } | 
 |  | 
 |     memset(boot->command, 0, sizeof(boot->command)); | 
 |     return false; | 
 | } | 
 |  | 
 | void HandlePowerctlMessage(const std::string& command) { | 
 |     unsigned int cmd = 0; | 
 |     std::vector<std::string> cmd_params = Split(command, ","); | 
 |     std::string reboot_target = ""; | 
 |     bool run_fsck = false; | 
 |     bool command_invalid = false; | 
 |     bool userspace_reboot = 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]; | 
 |             if (reboot_target == "userspace") { | 
 |                 LOG(INFO) << "Userspace reboot requested"; | 
 |                 userspace_reboot = true; | 
 |             } | 
 |             // 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 (!CommandIsPresent(&boot)) { | 
 |                     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; | 
 |                     } | 
 |                 } | 
 |             } else if (reboot_target == "quiescent") { | 
 |                 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 (!CommandIsPresent(&boot)) { | 
 |                     strlcpy(boot.command, "boot-quiescent", sizeof(boot.command)); | 
 |                     if (std::string err; !write_bootloader_message(boot, &err)) { | 
 |                         LOG(ERROR) << "Failed to set bootloader message: " << err; | 
 |                         return; | 
 |                     } | 
 |                 } | 
 |             } 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<std::string> options = { | 
 |                         "--" + arg, | 
 |                 }; | 
 |                 std::string err; | 
 |                 if (!write_bootloader_message(options, &err)) { | 
 |                     LOG(ERROR) << "Failed to set bootloader message: " << err; | 
 |                     return; | 
 |                 } | 
 |                 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; | 
 |     } | 
 |  | 
 |     // We do not want to process any messages (queue'ing triggers, shutdown messages, control | 
 |     // messages, etc) from properties during reboot. | 
 |     StopSendingMessages(); | 
 |  | 
 |     if (userspace_reboot) { | 
 |         HandleUserspaceReboot(); | 
 |         return; | 
 |     } | 
 |  | 
 |     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<void>{}; | 
 |     }; | 
 |     ActionManager::GetInstance().QueueBuiltinAction(shutdown_handler, "shutdown_done"); | 
 |  | 
 |     EnterShutdown(); | 
 | } | 
 |  | 
 | bool IsShuttingDown() { | 
 |     return shutting_down; | 
 | } | 
 |  | 
 | }  // namespace init | 
 | }  // namespace android |