diff --git a/adb/client/commandline.cpp b/adb/client/commandline.cpp
index 813a8a9..83b9238 100644
--- a/adb/client/commandline.cpp
+++ b/adb/client/commandline.cpp
@@ -790,6 +790,15 @@
                        service_string);
 }
 
+static int adb_shell_noinput(int argc, const char** argv) {
+#if !defined(_WIN32)
+    unique_fd fd(adb_open("/dev/null", O_RDONLY));
+    CHECK_NE(STDIN_FILENO, fd.get());
+    dup2(fd.get(), STDIN_FILENO);
+#endif
+    return adb_shell(argc, argv);
+}
+
 static int adb_sideload_legacy(const char* filename, int in_fd, int size) {
     std::string error;
     unique_fd out_fd(adb_connect(android::base::StringPrintf("sideload:%d", size), &error));
@@ -1612,7 +1621,7 @@
         return adb_query_command(query);
     }
     else if (!strcmp(argv[0], "connect")) {
-        if (argc != 2) error_exit("usage: adb connect HOST[:PORT>]");
+        if (argc != 2) error_exit("usage: adb connect HOST[:PORT]");
 
         std::string query = android::base::StringPrintf("host:connect:%s", argv[1]);
         return adb_query_command(query);
@@ -1711,7 +1720,7 @@
         if (CanUseFeature(features, kFeatureRemountShell)) {
             std::vector<const char*> args = {"shell"};
             args.insert(args.cend(), argv, argv + argc);
-            return adb_shell(args.size(), args.data());
+            return adb_shell_noinput(args.size(), args.data());
         } else if (argc > 1) {
             auto command = android::base::StringPrintf("%s:%s", argv[0], argv[1]);
             return adb_connect_command(command);
diff --git a/fs_mgr/libfiemap/include/libfiemap/fiemap_status.h b/fs_mgr/libfiemap/include/libfiemap/fiemap_status.h
index 56917cc..d7b2cf1 100644
--- a/fs_mgr/libfiemap/include/libfiemap/fiemap_status.h
+++ b/fs_mgr/libfiemap/include/libfiemap/fiemap_status.h
@@ -56,10 +56,12 @@
     // For logging and debugging only.
     std::string string() const;
 
+  protected:
+    FiemapStatus(ErrorCode code) : error_code_(code) {}
+
   private:
     ErrorCode error_code_;
 
-    FiemapStatus(ErrorCode code) : error_code_(code) {}
     static ErrorCode CastErrorCode(int error);
 };
 
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
index 52f8794..6e613ba 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
@@ -116,8 +116,30 @@
     using MetadataBuilder = android::fs_mgr::MetadataBuilder;
     using DeltaArchiveManifest = chromeos_update_engine::DeltaArchiveManifest;
     using MergeStatus = android::hardware::boot::V1_1::MergeStatus;
+    using FiemapStatus = android::fiemap::FiemapStatus;
 
   public:
+    // SnapshotManager functions return either bool or Return objects. "Return" types provides
+    // more information about the reason of the failure.
+    class Return : public FiemapStatus {
+      public:
+        // Total required size on /userdata.
+        uint64_t required_size() const { return required_size_; }
+
+        static Return Ok() { return Return(FiemapStatus::ErrorCode::SUCCESS); }
+        static Return Error() { return Return(FiemapStatus::ErrorCode::ERROR); }
+        static Return NoSpace(uint64_t size) {
+            return Return(FiemapStatus::ErrorCode::NO_SPACE, size);
+        }
+        // Does not set required_size_ properly even when status.error_code() == NO_SPACE.
+        explicit Return(const FiemapStatus& status) : Return(status.error_code()) {}
+
+      private:
+        uint64_t required_size_;
+        Return(FiemapStatus::ErrorCode code, uint64_t required_size = 0)
+            : FiemapStatus(code), required_size_(required_size) {}
+    };
+
     // Dependency injection for testing.
     class IDeviceInfo {
       public:
@@ -222,7 +244,7 @@
     // Create necessary COW device / files for OTA clients. New logical partitions will be added to
     // group "cow" in target_metadata. Regions of partitions of current_metadata will be
     // "write-protected" and snapshotted.
-    bool CreateUpdateSnapshots(const DeltaArchiveManifest& manifest);
+    Return CreateUpdateSnapshots(const DeltaArchiveManifest& manifest);
 
     // Map a snapshotted partition for OTA clients to write to. Write-protected regions are
     // determined previously in CreateSnapshots.
@@ -359,7 +381,7 @@
 
     // |name| should be the base partition name (e.g. "system_a"). Create the
     // backing COW image using the size previously passed to CreateSnapshot().
-    bool CreateCowImage(LockedFile* lock, const std::string& name);
+    Return CreateCowImage(LockedFile* lock, const std::string& name);
 
     // Map a snapshot device that was previously created with CreateSnapshot.
     // If a merge was previously initiated, the device-mapper table will have a
@@ -499,14 +521,14 @@
 
     // Helper for CreateUpdateSnapshots.
     // Creates all underlying images, COW partitions and snapshot files. Does not initialize them.
-    bool CreateUpdateSnapshotsInternal(LockedFile* lock, const DeltaArchiveManifest& manifest,
-                                       PartitionCowCreator* cow_creator,
-                                       AutoDeviceList* created_devices,
-                                       std::map<std::string, SnapshotStatus>* all_snapshot_status);
+    Return CreateUpdateSnapshotsInternal(
+            LockedFile* lock, const DeltaArchiveManifest& manifest,
+            PartitionCowCreator* cow_creator, AutoDeviceList* created_devices,
+            std::map<std::string, SnapshotStatus>* all_snapshot_status);
 
     // Initialize snapshots so that they can be mapped later.
     // Map the COW partition and zero-initialize the header.
-    bool InitializeUpdateSnapshots(
+    Return InitializeUpdateSnapshots(
             LockedFile* lock, MetadataBuilder* target_metadata,
             const LpMetadata* exported_target_metadata, const std::string& target_suffix,
             const std::map<std::string, SnapshotStatus>& all_snapshot_status);
diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index fd89ca0..b79b65c 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -54,6 +54,7 @@
 using android::dm::DmTargetSnapshot;
 using android::dm::kSectorSize;
 using android::dm::SnapshotStorageMode;
+using android::fiemap::FiemapStatus;
 using android::fiemap::IImageManager;
 using android::fs_mgr::CreateDmTable;
 using android::fs_mgr::CreateLogicalPartition;
@@ -289,14 +290,14 @@
     return true;
 }
 
-bool SnapshotManager::CreateCowImage(LockedFile* lock, const std::string& name) {
+SnapshotManager::Return SnapshotManager::CreateCowImage(LockedFile* lock, const std::string& name) {
     CHECK(lock);
     CHECK(lock->lock_mode() == LOCK_EX);
-    if (!EnsureImageManager()) return false;
+    if (!EnsureImageManager()) return Return::Error();
 
     SnapshotStatus status;
     if (!ReadSnapshotStatus(lock, name, &status)) {
-        return false;
+        return Return::Error();
     }
 
     // The COW file size should have been rounded up to the nearest sector in CreateSnapshot.
@@ -304,12 +305,12 @@
     if (status.cow_file_size() % kSectorSize != 0) {
         LOG(ERROR) << "Snapshot " << name << " COW file size is not a multiple of the sector size: "
                    << status.cow_file_size();
-        return false;
+        return Return::Error();
     }
 
     std::string cow_image_name = GetCowImageDeviceName(name);
     int cow_flags = IImageManager::CREATE_IMAGE_DEFAULT;
-    return images_->CreateBackingImage(cow_image_name, status.cow_file_size(), cow_flags);
+    return Return(images_->CreateBackingImage(cow_image_name, status.cow_file_size(), cow_flags));
 }
 
 bool SnapshotManager::MapSnapshot(LockedFile* lock, const std::string& name,
@@ -1844,9 +1845,23 @@
     }
 }
 
-bool SnapshotManager::CreateUpdateSnapshots(const DeltaArchiveManifest& manifest) {
+static SnapshotManager::Return AddRequiredSpace(
+        SnapshotManager::Return orig,
+        const std::map<std::string, SnapshotStatus>& all_snapshot_status) {
+    if (orig.error_code() != SnapshotManager::Return::ErrorCode::NO_SPACE) {
+        return orig;
+    }
+    uint64_t sum = 0;
+    for (auto&& [name, status] : all_snapshot_status) {
+        sum += status.cow_file_size();
+    }
+    return SnapshotManager::Return::NoSpace(sum);
+}
+
+SnapshotManager::Return SnapshotManager::CreateUpdateSnapshots(
+        const DeltaArchiveManifest& manifest) {
     auto lock = LockExclusive();
-    if (!lock) return false;
+    if (!lock) return Return::Error();
 
     // TODO(b/134949511): remove this check. Right now, with overlayfs mounted, the scratch
     // partition takes up a big chunk of space in super, causing COW images to be created on
@@ -1854,7 +1869,7 @@
     if (device_->IsOverlayfsSetup()) {
         LOG(ERROR) << "Cannot create update snapshots with overlayfs setup. Run `adb enable-verity`"
                    << ", reboot, then try again.";
-        return false;
+        return Return::Error();
     }
 
     const auto& opener = device_->GetPartitionOpener();
@@ -1879,7 +1894,7 @@
     SnapshotMetadataUpdater metadata_updater(target_metadata.get(), target_slot, manifest);
     if (!metadata_updater.Update()) {
         LOG(ERROR) << "Cannot calculate new metadata.";
-        return false;
+        return Return::Error();
     }
 
     // Delete previous COW partitions in current_metadata so that PartitionCowCreator marks those as
@@ -1911,36 +1926,34 @@
             .extra_extents = {},
     };
 
-    if (!CreateUpdateSnapshotsInternal(lock.get(), manifest, &cow_creator, &created_devices,
-                                       &all_snapshot_status)) {
-        return false;
-    }
+    auto ret = CreateUpdateSnapshotsInternal(lock.get(), manifest, &cow_creator, &created_devices,
+                                             &all_snapshot_status);
+    if (!ret.is_ok()) return ret;
 
     auto exported_target_metadata = target_metadata->Export();
     if (exported_target_metadata == nullptr) {
         LOG(ERROR) << "Cannot export target metadata";
-        return false;
+        return Return::Error();
     }
 
-    if (!InitializeUpdateSnapshots(lock.get(), target_metadata.get(),
-                                   exported_target_metadata.get(), target_suffix,
-                                   all_snapshot_status)) {
-        return false;
-    }
+    ret = InitializeUpdateSnapshots(lock.get(), target_metadata.get(),
+                                    exported_target_metadata.get(), target_suffix,
+                                    all_snapshot_status);
+    if (!ret.is_ok()) return ret;
 
     if (!UpdatePartitionTable(opener, device_->GetSuperDevice(target_slot),
                               *exported_target_metadata, target_slot)) {
         LOG(ERROR) << "Cannot write target metadata";
-        return false;
+        return Return::Error();
     }
 
     created_devices.Release();
     LOG(INFO) << "Successfully created all snapshots for target slot " << target_suffix;
 
-    return true;
+    return Return::Ok();
 }
 
-bool SnapshotManager::CreateUpdateSnapshotsInternal(
+SnapshotManager::Return SnapshotManager::CreateUpdateSnapshotsInternal(
         LockedFile* lock, const DeltaArchiveManifest& manifest, PartitionCowCreator* cow_creator,
         AutoDeviceList* created_devices,
         std::map<std::string, SnapshotStatus>* all_snapshot_status) {
@@ -1951,7 +1964,7 @@
 
     if (!target_metadata->AddGroup(kCowGroupName, 0)) {
         LOG(ERROR) << "Cannot add group " << kCowGroupName;
-        return false;
+        return Return::Error();
     }
 
     std::map<std::string, const RepeatedPtrField<InstallOperation>*> install_operation_map;
@@ -1963,7 +1976,7 @@
         if (!inserted) {
             LOG(ERROR) << "Duplicated partition " << partition_update.partition_name()
                        << " in update manifest.";
-            return false;
+            return Return::Error();
         }
 
         auto& extra_extents = extra_extents_map[suffixed_name];
@@ -1992,7 +2005,7 @@
         // Compute the device sizes for the partition.
         auto cow_creator_ret = cow_creator->Run();
         if (!cow_creator_ret.has_value()) {
-            return false;
+            return Return::Error();
         }
 
         LOG(INFO) << "For partition " << target_partition->name()
@@ -2006,7 +2019,7 @@
         if (!DeleteSnapshot(lock, target_partition->name())) {
             LOG(ERROR) << "Cannot delete existing snapshot before creating a new one for partition "
                        << target_partition->name();
-            return false;
+            return Return::Error();
         }
 
         // It is possible that the whole partition uses free space in super, and snapshot / COW
@@ -2024,7 +2037,7 @@
 
         // Store these device sizes to snapshot status file.
         if (!CreateSnapshot(lock, &cow_creator_ret->snapshot_status)) {
-            return false;
+            return Return::Error();
         }
         created_devices->EmplaceBack<AutoDeleteSnapshot>(this, lock, target_partition->name());
 
@@ -2038,7 +2051,7 @@
             auto cow_partition = target_metadata->AddPartition(GetCowName(target_partition->name()),
                                                                kCowGroupName, 0 /* flags */);
             if (cow_partition == nullptr) {
-                return false;
+                return Return::Error();
             }
 
             if (!target_metadata->ResizePartition(
@@ -2046,28 +2059,34 @@
                         cow_creator_ret->cow_partition_usable_regions)) {
                 LOG(ERROR) << "Cannot create COW partition on metadata with size "
                            << cow_creator_ret->snapshot_status.cow_partition_size();
-                return false;
+                return Return::Error();
             }
             // Only the in-memory target_metadata is modified; nothing to clean up if there is an
             // error in the future.
         }
 
-        // Create the backing COW image if necessary.
-        if (cow_creator_ret->snapshot_status.cow_file_size() > 0) {
-            if (!CreateCowImage(lock, target_partition->name())) {
-                return false;
-            }
-        }
-
         all_snapshot_status->emplace(target_partition->name(),
                                      std::move(cow_creator_ret->snapshot_status));
 
-        LOG(INFO) << "Successfully created snapshot for " << target_partition->name();
+        LOG(INFO) << "Successfully created snapshot partition for " << target_partition->name();
     }
-    return true;
+
+    LOG(INFO) << "Allocating CoW images.";
+
+    for (auto&& [name, snapshot_status] : *all_snapshot_status) {
+        // Create the backing COW image if necessary.
+        if (snapshot_status.cow_file_size() > 0) {
+            auto ret = CreateCowImage(lock, name);
+            if (!ret.is_ok()) return AddRequiredSpace(ret, *all_snapshot_status);
+        }
+
+        LOG(INFO) << "Successfully created snapshot for " << name;
+    }
+
+    return Return::Ok();
 }
 
-bool SnapshotManager::InitializeUpdateSnapshots(
+SnapshotManager::Return SnapshotManager::InitializeUpdateSnapshots(
         LockedFile* lock, MetadataBuilder* target_metadata,
         const LpMetadata* exported_target_metadata, const std::string& target_suffix,
         const std::map<std::string, SnapshotStatus>& all_snapshot_status) {
@@ -2086,7 +2105,7 @@
         if (!UnmapPartitionWithSnapshot(lock, target_partition->name())) {
             LOG(ERROR) << "Cannot unmap existing COW devices before re-mapping them for zero-fill: "
                        << target_partition->name();
-            return false;
+            return Return::Error();
         }
 
         auto it = all_snapshot_status.find(target_partition->name());
@@ -2094,23 +2113,24 @@
         cow_params.partition_name = target_partition->name();
         std::string cow_name;
         if (!MapCowDevices(lock, cow_params, it->second, &created_devices_for_cow, &cow_name)) {
-            return false;
+            return Return::Error();
         }
 
         std::string cow_path;
         if (!dm.GetDmDevicePathByName(cow_name, &cow_path)) {
             LOG(ERROR) << "Cannot determine path for " << cow_name;
-            return false;
+            return Return::Error();
         }
 
-        if (!InitializeCow(cow_path)) {
+        auto ret = InitializeCow(cow_path);
+        if (!ret.is_ok()) {
             LOG(ERROR) << "Can't zero-fill COW device for " << target_partition->name() << ": "
                        << cow_path;
-            return false;
+            return AddRequiredSpace(ret, all_snapshot_status);
         }
         // Let destructor of created_devices_for_cow to unmap the COW devices.
     };
-    return true;
+    return Return::Ok();
 }
 
 bool SnapshotManager::MapUpdateSnapshot(const CreateLogicalPartitionParams& params,
diff --git a/fs_mgr/libsnapshot/snapshot_test.cpp b/fs_mgr/libsnapshot/snapshot_test.cpp
index 9e2719f..cea9d69 100644
--- a/fs_mgr/libsnapshot/snapshot_test.cpp
+++ b/fs_mgr/libsnapshot/snapshot_test.cpp
@@ -1586,6 +1586,29 @@
     ASSERT_THAT(merger.get(), AnyOf(UpdateState::None, UpdateState::MergeCompleted));
 }
 
+TEST_F(SnapshotUpdateTest, LowSpace) {
+    static constexpr auto kMaxFree = 10_MiB;
+    auto userdata = std::make_unique<LowSpaceUserdata>();
+    ASSERT_TRUE(userdata->Init(kMaxFree));
+
+    // Grow all partitions to 5_MiB, total 15_MiB. This requires 15 MiB of CoW space. After
+    // using the empty space in super (< 1 MiB), it uses at least 14 MiB of /userdata space.
+    constexpr uint64_t partition_size = 5_MiB;
+    SetSize(sys_, partition_size);
+    SetSize(vnd_, partition_size);
+    SetSize(prd_, partition_size);
+
+    AddOperationForPartitions();
+
+    // Execute the update.
+    ASSERT_TRUE(sm->BeginUpdate());
+    auto res = sm->CreateUpdateSnapshots(manifest_);
+    ASSERT_FALSE(res);
+    ASSERT_EQ(SnapshotManager::Return::ErrorCode::NO_SPACE, res.error_code());
+    ASSERT_GE(res.required_size(), 14_MiB);
+    ASSERT_LT(res.required_size(), 15_MiB);
+}
+
 class FlashAfterUpdateTest : public SnapshotUpdateTest,
                              public WithParamInterface<std::tuple<uint32_t, bool>> {
   public:
diff --git a/fs_mgr/libsnapshot/utility.cpp b/fs_mgr/libsnapshot/utility.cpp
index fa1d7f0..f01500f 100644
--- a/fs_mgr/libsnapshot/utility.cpp
+++ b/fs_mgr/libsnapshot/utility.cpp
@@ -14,12 +14,15 @@
 
 #include "utility.h"
 
+#include <errno.h>
+
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <android-base/strings.h>
 #include <fs_mgr/roots.h>
 
 using android::dm::kSectorSize;
+using android::fiemap::FiemapStatus;
 using android::fs_mgr::EnsurePathMounted;
 using android::fs_mgr::EnsurePathUnmounted;
 using android::fs_mgr::Fstab;
@@ -83,7 +86,9 @@
     }
 }
 
-bool InitializeCow(const std::string& device) {
+SnapshotManager::Return InitializeCow(const std::string& device) {
+    using Return = SnapshotManager::Return;
+
     // When the kernel creates a persistent dm-snapshot, it requires a CoW file
     // to store the modifications. The kernel interface does not specify how
     // the CoW is used, and there is no standard associated.
@@ -103,15 +108,15 @@
     android::base::unique_fd fd(open(device.c_str(), O_WRONLY | O_BINARY));
     if (fd < 0) {
         PLOG(ERROR) << "Can't open COW device: " << device;
-        return false;
+        return Return(FiemapStatus::FromErrno(errno));
     }
 
     LOG(INFO) << "Zero-filling COW device: " << device;
     if (!android::base::WriteFully(fd, zeros.data(), kDmSnapZeroFillSize)) {
         PLOG(ERROR) << "Can't zero-fill COW device for " << device;
-        return false;
+        return Return(FiemapStatus::FromErrno(errno));
     }
-    return true;
+    return Return::Ok();
 }
 
 std::unique_ptr<AutoUnmountDevice> AutoUnmountDevice::New(const std::string& path) {
diff --git a/fs_mgr/libsnapshot/utility.h b/fs_mgr/libsnapshot/utility.h
index 5cc572e..0453256 100644
--- a/fs_mgr/libsnapshot/utility.h
+++ b/fs_mgr/libsnapshot/utility.h
@@ -26,6 +26,7 @@
 #include <update_engine/update_metadata.pb.h>
 
 #include <libsnapshot/auto_device.h>
+#include <libsnapshot/snapshot.h>
 
 namespace android {
 namespace snapshot {
@@ -110,7 +111,7 @@
         android::fs_mgr::MetadataBuilder* builder, const std::string& suffix);
 
 // Initialize a device before using it as the COW device for a dm-snapshot device.
-bool InitializeCow(const std::string& device);
+SnapshotManager::Return InitializeCow(const std::string& device);
 
 // "Atomically" write string to file. This is done by a series of actions:
 // 1. Write to path + ".tmp"
diff --git a/init/reboot.cpp b/init/reboot.cpp
index 225bc9c..4ee7188 100644
--- a/init/reboot.cpp
+++ b/init/reboot.cpp
@@ -860,6 +860,30 @@
     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, ",");
@@ -912,7 +936,7 @@
                 }
                 // Update the boot command field if it's empty, and preserve
                 // the other arguments in the bootloader message.
-                if (boot.command[0] == '\0') {
+                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;
diff --git a/init/reboot_utils.cpp b/init/reboot_utils.cpp
index dac0cf4..485188b 100644
--- a/init/reboot_utils.cpp
+++ b/init/reboot_utils.cpp
@@ -34,12 +34,16 @@
 namespace init {
 
 static std::string init_fatal_reboot_target = "bootloader";
+static bool init_fatal_panic = false;
 
 void SetFatalRebootTarget() {
     std::string cmdline;
     android::base::ReadFileToString("/proc/cmdline", &cmdline);
     cmdline = android::base::Trim(cmdline);
 
+    const char kInitFatalPanicString[] = "androidboot.init_fatal_panic=true";
+    init_fatal_panic = cmdline.find(kInitFatalPanicString) != std::string::npos;
+
     const char kRebootTargetString[] = "androidboot.init_fatal_reboot_target=";
     auto start_pos = cmdline.find(kRebootTargetString);
     if (start_pos == std::string::npos) {
@@ -133,6 +137,9 @@
     for (size_t i = 0; i < backtrace->NumFrames(); i++) {
         LOG(ERROR) << backtrace->FormatFrameData(i);
     }
+    if (init_fatal_panic) {
+        _exit(signal_number);
+    }
     RebootSystem(ANDROID_RB_RESTART2, init_fatal_reboot_target);
 }
 
diff --git a/libcutils/fs_config.cpp b/libcutils/fs_config.cpp
index dc31b28..65c59bd 100644
--- a/libcutils/fs_config.cpp
+++ b/libcutils/fs_config.cpp
@@ -196,10 +196,6 @@
     { 00750, AID_ROOT,      AID_SHELL,     CAP_MASK_LONG(CAP_SETUID) |
                                            CAP_MASK_LONG(CAP_SETGID),
                                               "system/bin/simpleperf_app_runner" },
-
-    // Support FIFO scheduling mode in SurfaceFlinger.
-    { 00755, AID_SYSTEM,    AID_GRAPHICS,  CAP_MASK_LONG(CAP_SYS_NICE),
-                                              "system/bin/surfaceflinger" },
     // generic defaults
     { 00755, AID_ROOT,      AID_ROOT,      0, "bin/*" },
     { 00640, AID_ROOT,      AID_SHELL,     0, "fstab.*" },
diff --git a/liblog/fake_log_device.cpp b/liblog/fake_log_device.cpp
index 2ec6393..af9f18b 100644
--- a/liblog/fake_log_device.cpp
+++ b/liblog/fake_log_device.cpp
@@ -49,14 +49,6 @@
 #define TRACE(...) ((void)0)
 #endif
 
-static void FakeClose();
-static int FakeWrite(log_id_t log_id, struct timespec* ts, struct iovec* vec, size_t nr);
-
-struct android_log_transport_write fakeLoggerWrite = {
-    .close = FakeClose,
-    .write = FakeWrite,
-};
-
 typedef struct LogState {
   bool initialized = false;
   /* global minimum priority */
@@ -453,7 +445,7 @@
  *  tag (N bytes -- null-terminated ASCII string)
  *  message (N bytes -- null-terminated ASCII string)
  */
-static int FakeWrite(log_id_t log_id, struct timespec*, struct iovec* vector, size_t count) {
+int FakeWrite(log_id_t log_id, struct timespec*, struct iovec* vector, size_t count) {
   /* Make sure that no-one frees the LogState while we're using it.
    * Also guarantees that only one thread is in showLog() at a given
    * time (if it matters).
@@ -519,7 +511,7 @@
  * call is in the exit handler. Logging can continue in the exit handler to
  * help debug HOST tools ...
  */
-static void FakeClose() {
+void FakeClose() {
   auto lock = std::lock_guard{*fake_log_mutex};
 
   memset(&log_state, 0, sizeof(log_state));
diff --git a/liblog/fake_log_device.h b/liblog/fake_log_device.h
index bd2256c..a2b40e2 100644
--- a/liblog/fake_log_device.h
+++ b/liblog/fake_log_device.h
@@ -18,16 +18,14 @@
 
 #include <sys/types.h>
 
-#include "log_portability.h"
-#include "uio.h"
+#include <android/log.h>
 
-struct iovec;
+#include "log_portability.h"
 
 __BEGIN_DECLS
 
-int fakeLogOpen(const char* pathName);
-int fakeLogClose(int fd);
-ssize_t fakeLogWritev(int fd, const struct iovec* vector, int count);
+void FakeClose();
+int FakeWrite(log_id_t log_id, struct timespec* ts, struct iovec* vec, size_t nr);
 
 int __android_log_is_loggable(int prio, const char*, int def);
 int __android_log_is_loggable_len(int prio, const char*, size_t, int def);
diff --git a/liblog/logd_reader.cpp b/liblog/logd_reader.cpp
index 6865c14..82ed6b2 100644
--- a/liblog/logd_reader.cpp
+++ b/liblog/logd_reader.cpp
@@ -35,8 +35,6 @@
 
 #include <string>
 
-#include <cutils/sockets.h>
-#include <private/android_filesystem_config.h>
 #include <private/android_logger.h>
 
 #include "logger.h"
diff --git a/liblog/logd_writer.cpp b/liblog/logd_writer.cpp
index 3c6eb69..f49c59e 100644
--- a/liblog/logd_writer.cpp
+++ b/liblog/logd_writer.cpp
@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#include "logd_writer.h"
+
 #include <errno.h>
 #include <fcntl.h>
 #include <inttypes.h>
@@ -32,7 +34,6 @@
 
 #include <shared_mutex>
 
-#include <cutils/sockets.h>
 #include <private/android_filesystem_config.h>
 #include <private/android_logger.h>
 
@@ -41,14 +42,6 @@
 #include "rwlock.h"
 #include "uio.h"
 
-static int LogdWrite(log_id_t logId, struct timespec* ts, struct iovec* vec, size_t nr);
-static void LogdClose();
-
-struct android_log_transport_write logdLoggerWrite = {
-    .close = LogdClose,
-    .write = LogdWrite,
-};
-
 static int logd_socket;
 static RwLock logd_socket_lock;
 
@@ -90,7 +83,7 @@
   OpenSocketLocked();
 }
 
-static void LogdClose() {
+void LogdClose() {
   auto lock = std::unique_lock{logd_socket_lock};
   if (logd_socket > 0) {
     close(logd_socket);
@@ -98,7 +91,7 @@
   logd_socket = 0;
 }
 
-static int LogdWrite(log_id_t logId, struct timespec* ts, struct iovec* vec, size_t nr) {
+int LogdWrite(log_id_t logId, struct timespec* ts, struct iovec* vec, size_t nr) {
   ssize_t ret;
   static const unsigned headerLength = 1;
   struct iovec newVec[nr + headerLength];
@@ -119,7 +112,7 @@
   }
 
   /* logd, after initialization and priv drop */
-  if (__android_log_uid() == AID_LOGD) {
+  if (getuid() == AID_LOGD) {
     /*
      * ignore log messages we send to ourself (logd).
      * Such log messages are often generated by libraries we depend on
diff --git a/liblog/logd_writer.h b/liblog/logd_writer.h
new file mode 100644
index 0000000..41197b5
--- /dev/null
+++ b/liblog/logd_writer.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+#pragma once
+
+#include <stddef.h>
+
+#include <android/log.h>
+
+int LogdWrite(log_id_t logId, struct timespec* ts, struct iovec* vec, size_t nr);
+void LogdClose();
diff --git a/liblog/logger.h b/liblog/logger.h
index 40d5fe5..078e778 100644
--- a/liblog/logger.h
+++ b/liblog/logger.h
@@ -18,7 +18,6 @@
 
 #include <stdatomic.h>
 
-#include <cutils/list.h>
 #include <log/log.h>
 
 #include "log_portability.h"
@@ -26,13 +25,6 @@
 
 __BEGIN_DECLS
 
-struct android_log_transport_write {
-  void (*close)(); /* free up resources */
-  /* write log to transport, returns number of bytes propagated, or -errno */
-  int (*write)(log_id_t logId, struct timespec* ts, struct iovec* vec,
-               size_t nr);
-};
-
 struct logger_list {
   atomic_int fd;
   int mode;
@@ -56,18 +48,4 @@
   return reinterpret_cast<uintptr_t>(logger) & LOGGER_LOGD;
 }
 
-/* OS specific dribs and drabs */
-
-#if defined(_WIN32)
-#include <private/android_filesystem_config.h>
-typedef uint32_t uid_t;
-static inline uid_t __android_log_uid() {
-  return AID_SYSTEM;
-}
-#else
-static inline uid_t __android_log_uid() {
-  return getuid();
-}
-#endif
-
 __END_DECLS
diff --git a/liblog/logger_read.cpp b/liblog/logger_read.cpp
index 0d383ff..a13ab36 100644
--- a/liblog/logger_read.cpp
+++ b/liblog/logger_read.cpp
@@ -27,8 +27,6 @@
 #include <unistd.h>
 
 #include <android/log.h>
-#include <cutils/list.h>
-#include <private/android_filesystem_config.h>
 
 #include "log_portability.h"
 #include "logd_reader.h"
diff --git a/liblog/logger_write.cpp b/liblog/logger_write.cpp
index d38b402..77be581 100644
--- a/liblog/logger_write.cpp
+++ b/liblog/logger_write.cpp
@@ -15,7 +15,6 @@
  */
 
 #include <errno.h>
-#include <stdatomic.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/time.h>
@@ -31,24 +30,18 @@
 #include "logger.h"
 #include "uio.h"
 
-#define LOG_BUF_SIZE 1024
-
 #if (FAKE_LOG_DEVICE == 0)
-extern struct android_log_transport_write logdLoggerWrite;
-extern struct android_log_transport_write pmsgLoggerWrite;
-
-android_log_transport_write* android_log_write = &logdLoggerWrite;
-android_log_transport_write* android_log_persist_write = &pmsgLoggerWrite;
+#include "logd_writer.h"
+#include "pmsg_writer.h"
 #else
-extern android_log_transport_write fakeLoggerWrite;
-
-android_log_transport_write* android_log_write = &fakeLoggerWrite;
-android_log_transport_write* android_log_persist_write = nullptr;
+#include "fake_log_device.h"
 #endif
 
+#define LOG_BUF_SIZE 1024
+
 #if defined(__ANDROID__)
 static int check_log_uid_permissions() {
-  uid_t uid = __android_log_uid();
+  uid_t uid = getuid();
 
   /* Matches clientHasLogCredentials() in logd */
   if ((uid != AID_SYSTEM) && (uid != AID_ROOT) && (uid != AID_LOG)) {
@@ -92,14 +85,12 @@
  * Release any logger resources. A new log write will immediately re-acquire.
  */
 void __android_log_close() {
-  if (android_log_write != nullptr) {
-    android_log_write->close();
-  }
-
-  if (android_log_persist_write != nullptr) {
-    android_log_persist_write->close();
-  }
-
+#if (FAKE_LOG_DEVICE == 0)
+  LogdClose();
+  PmsgClose();
+#else
+  FakeClose();
+#endif
 }
 
 static int write_to_log(log_id_t log_id, struct iovec* vec, size_t nr) {
@@ -158,17 +149,12 @@
 
   ret = 0;
 
-  if (android_log_write != nullptr) {
-    ssize_t retval;
-    retval = android_log_write->write(log_id, &ts, vec, nr);
-    if (ret >= 0) {
-      ret = retval;
-    }
-  }
-
-  if (android_log_persist_write != nullptr) {
-    android_log_persist_write->write(log_id, &ts, vec, nr);
-  }
+#if (FAKE_LOG_DEVICE == 0)
+  ret = LogdWrite(log_id, &ts, vec, nr);
+  PmsgWrite(log_id, &ts, vec, nr);
+#else
+  ret = FakeWrite(log_id, &ts, vec, nr);
+#endif
 
   errno = save_errno;
   return ret;
diff --git a/liblog/pmsg_reader.cpp b/liblog/pmsg_reader.cpp
index 9390fec..64a92b7 100644
--- a/liblog/pmsg_reader.cpp
+++ b/liblog/pmsg_reader.cpp
@@ -23,7 +23,7 @@
 #include <string.h>
 #include <sys/types.h>
 
-#include <private/android_filesystem_config.h>
+#include <cutils/list.h>
 #include <private/android_logger.h>
 
 #include "logger.h"
diff --git a/liblog/pmsg_writer.cpp b/liblog/pmsg_writer.cpp
index 4f45780..319360f 100644
--- a/liblog/pmsg_writer.cpp
+++ b/liblog/pmsg_writer.cpp
@@ -14,9 +14,7 @@
  * limitations under the License.
  */
 
-/*
- * pmsg write handler
- */
+#include "pmsg_writer.h"
 
 #include <errno.h>
 #include <fcntl.h>
@@ -28,7 +26,6 @@
 #include <shared_mutex>
 
 #include <log/log_properties.h>
-#include <private/android_filesystem_config.h>
 #include <private/android_logger.h>
 
 #include "log_portability.h"
@@ -36,14 +33,6 @@
 #include "rwlock.h"
 #include "uio.h"
 
-static void PmsgClose();
-static int PmsgWrite(log_id_t logId, struct timespec* ts, struct iovec* vec, size_t nr);
-
-struct android_log_transport_write pmsgLoggerWrite = {
-    .close = PmsgClose,
-    .write = PmsgWrite,
-};
-
 static int pmsg_fd;
 static RwLock pmsg_fd_lock;
 
@@ -57,7 +46,7 @@
   pmsg_fd = TEMP_FAILURE_RETRY(open("/dev/pmsg0", O_WRONLY | O_CLOEXEC));
 }
 
-static void PmsgClose() {
+void PmsgClose() {
   auto lock = std::unique_lock{pmsg_fd_lock};
   if (pmsg_fd > 0) {
     close(pmsg_fd);
@@ -65,7 +54,7 @@
   pmsg_fd = 0;
 }
 
-static int PmsgWrite(log_id_t logId, struct timespec* ts, struct iovec* vec, size_t nr) {
+int PmsgWrite(log_id_t logId, struct timespec* ts, struct iovec* vec, size_t nr) {
   static const unsigned headerLength = 2;
   struct iovec newVec[nr + headerLength];
   android_log_header_t header;
@@ -123,7 +112,7 @@
 
   pmsgHeader.magic = LOGGER_MAGIC;
   pmsgHeader.len = sizeof(pmsgHeader) + sizeof(header);
-  pmsgHeader.uid = __android_log_uid();
+  pmsgHeader.uid = getuid();
   pmsgHeader.pid = getpid();
 
   header.id = logId;
diff --git a/liblog/pmsg_writer.h b/liblog/pmsg_writer.h
new file mode 100644
index 0000000..d5e1a1c
--- /dev/null
+++ b/liblog/pmsg_writer.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+#pragma once
+
+#include <stddef.h>
+
+#include <android/log.h>
+
+int PmsgWrite(log_id_t logId, struct timespec* ts, struct iovec* vec, size_t nr);
+void PmsgClose();
diff --git a/libutils/include/utils/Flattenable.h b/libutils/include/utils/Flattenable.h
index 953b859..17c5e10 100644
--- a/libutils/include/utils/Flattenable.h
+++ b/libutils/include/utils/Flattenable.h
@@ -52,7 +52,12 @@
 
     template<size_t N>
     static size_t align(void*& buffer) {
-        return align<N>( const_cast<void const*&>(buffer) );
+        static_assert(!(N & (N - 1)), "Can only align to a power of 2.");
+        void* b = buffer;
+        buffer = reinterpret_cast<void*>((uintptr_t(buffer) + (N-1)) & ~(N-1));
+        size_t delta = size_t(uintptr_t(buffer) - uintptr_t(b));
+        memset(b, 0, delta);
+        return delta;
     }
 
     static void advance(void*& buffer, size_t& size, size_t offset) {