/*
* 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/fs.h>
#include <mntent.h>
#include <linux/loop.h>
#include <sys/cdefs.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/swap.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <memory>
#include <set>
#include <thread>
#include <vector>
#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/stringprintf.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 <logwrap/logwrap.h>
#include <private/android_filesystem_config.h>
#include <selinux/selinux.h>
#include "action_manager.h"
#include "init.h"
#include "property_service.h"
#include "reboot_utils.h"
#include "service.h"
#include "sigchld_handler.h"
using android::base::GetBoolProperty;
using android::base::Split;
using android::base::StringPrintf;
using android::base::Timer;
using android::base::unique_fd;
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<MountEntry>* blockDevPartitions,
std::vector<MountEntry>* emulatedPartitions, 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") {
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
android::base::WriteStringToFile("l", "/proc/sysrq-trigger");
android::base::WriteStringToFile("w", "/proc/sysrq-trigger");
}
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() { android::base::WriteStringToFile("i", "/proc/sysrq-trigger"); }
/* 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(bool runFsck, std::chrono::milliseconds timeout) {
Timer t;
std::vector<MountEntry> block_devices;
std::vector<MountEntry> 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) {
// 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();
}
}
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 (!android::base::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<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,");
}
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";
// keep debugging tools until non critical ones are all gone.
const std::set<std::string> kill_after_apps{"tombstoned", "logd", "adbd"};
// watchdogd is a vendor specific component but should be alive to complete shutdown safely.
const std::set<std::string> 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().IgnoreError();
}
service->SetShutdownCritical(); // will not check animation class separately
}
if (do_shutdown_animation) {
bootAnim->Start().IgnoreError();
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(runFsck, shutdown_timeout - t.duration());
// 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);
// 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<std::string> cmd_params = Split(command, ",");
std::string reboot_target = "";
bool run_fsck = false;
bool command_invalid = false;
if (cmd_params.size() > 3) {
command_invalid = true;
} else 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 == "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 false;
}
reboot_target = "recovery";
}
// If there is an additional parameter, pass it along
if ((cmd_params.size() == 3) && cmd_params[2].size()) {
reboot_target += "," + cmd_params[2];
}
}
} 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 Success();
};
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