diff --git a/debuggerd/debuggerd_test.cpp b/debuggerd/debuggerd_test.cpp
index 85adbea..a5e2413 100644
--- a/debuggerd/debuggerd_test.cpp
+++ b/debuggerd/debuggerd_test.cpp
@@ -1825,9 +1825,9 @@
 TEST_F(CrasherTest, unreadable_elf) {
   int intercept_result;
   unique_fd output_fd;
-  StartProcess([]() {
+  std::string tmp_so_name;
+  StartProcess([&tmp_so_name]() {
     TemporaryDir td;
-    std::string tmp_so_name;
     if (!CopySharedLibrary(td.path, &tmp_so_name)) {
       _exit(1);
     }
@@ -1857,6 +1857,8 @@
   std::string result;
   ConsumeFd(std::move(output_fd), &result);
   ASSERT_MATCH(result, R"(NOTE: Function names and BuildId information is missing )");
+  std::string match_str = "NOTE:   " + tmp_so_name;
+  ASSERT_MATCH(result, match_str);
 }
 
 TEST(tombstoned, proto) {
diff --git a/debuggerd/libdebuggerd/tombstone_proto.cpp b/debuggerd/libdebuggerd/tombstone_proto.cpp
index 3e31bb7..bee4a67 100644
--- a/debuggerd/libdebuggerd/tombstone_proto.cpp
+++ b/debuggerd/libdebuggerd/tombstone_proto.cpp
@@ -35,6 +35,7 @@
 
 #include <memory>
 #include <optional>
+#include <set>
 #include <string>
 
 #include <async_safe/log.h>
@@ -419,18 +420,29 @@
     return;
   }
 
-  if (unwinder->elf_from_memory_not_file()) {
+  unwinder->SetDisplayBuildID(true);
+  std::set<std::string> unreadable_elf_files;
+  for (const auto& frame : unwinder->frames()) {
+    BacktraceFrame* f = thread.add_current_backtrace();
+    fill_in_backtrace_frame(f, frame);
+    if (frame.map_info != nullptr && frame.map_info->ElfFileNotReadable()) {
+      unreadable_elf_files.emplace(frame.map_info->name());
+    }
+  }
+
+  if (!unreadable_elf_files.empty()) {
+    auto unreadable_elf_files_proto = thread.mutable_unreadable_elf_files();
     auto backtrace_note = thread.mutable_backtrace_note();
     *backtrace_note->Add() =
         "Function names and BuildId information is missing for some frames due";
     *backtrace_note->Add() = "to unreadable libraries. For unwinds of apps, only shared libraries";
     *backtrace_note->Add() = "found under the lib/ directory are readable.";
     *backtrace_note->Add() = "On this device, run setenforce 0 to make the libraries readable.";
-  }
-  unwinder->SetDisplayBuildID(true);
-  for (const auto& frame : unwinder->frames()) {
-    BacktraceFrame* f = thread.add_current_backtrace();
-    fill_in_backtrace_frame(f, frame);
+    *backtrace_note->Add() = "Unreadable libraries:";
+    for (auto& name : unreadable_elf_files) {
+      *backtrace_note->Add() = "  " + name;
+      *unreadable_elf_files_proto->Add() = name;
+    }
   }
 }
 
diff --git a/debuggerd/libdebuggerd/utility.cpp b/debuggerd/libdebuggerd/utility.cpp
index 543a67c..ecd98a4 100644
--- a/debuggerd/libdebuggerd/utility.cpp
+++ b/debuggerd/libdebuggerd/utility.cpp
@@ -28,6 +28,7 @@
 #include <sys/wait.h>
 #include <unistd.h>
 
+#include <set>
 #include <string>
 
 #include <android-base/properties.h>
@@ -483,7 +484,16 @@
 }
 
 void log_backtrace(log_t* log, unwindstack::Unwinder* unwinder, const char* prefix) {
-  if (unwinder->elf_from_memory_not_file()) {
+  std::set<std::string> unreadable_elf_files;
+  unwinder->SetDisplayBuildID(true);
+  for (const auto& frame : unwinder->frames()) {
+    if (frame.map_info != nullptr && frame.map_info->ElfFileNotReadable()) {
+      unreadable_elf_files.emplace(frame.map_info->name());
+    }
+  }
+
+  // Put the preamble ahead of the backtrace.
+  if (!unreadable_elf_files.empty()) {
     _LOG(log, logtype::BACKTRACE,
          "%sNOTE: Function names and BuildId information is missing for some frames due\n", prefix);
     _LOG(log, logtype::BACKTRACE,
@@ -493,10 +503,13 @@
     _LOG(log, logtype::BACKTRACE,
          "%sNOTE: On this device, run setenforce 0 to make the libraries readable.\n", prefix);
 #endif
+    _LOG(log, logtype::BACKTRACE, "%sNOTE: Unreadable libraries:\n", prefix);
+    for (auto& name : unreadable_elf_files) {
+      _LOG(log, logtype::BACKTRACE, "%sNOTE:   %s\n", prefix, name.c_str());
+    }
   }
 
-  unwinder->SetDisplayBuildID(true);
-  for (size_t i = 0; i < unwinder->NumFrames(); i++) {
-    _LOG(log, logtype::BACKTRACE, "%s%s\n", prefix, unwinder->FormatFrame(i).c_str());
+  for (const auto& frame : unwinder->frames()) {
+    _LOG(log, logtype::BACKTRACE, "%s%s\n", prefix, unwinder->FormatFrame(frame).c_str());
   }
 }
diff --git a/debuggerd/proto/tombstone.proto b/debuggerd/proto/tombstone.proto
index 40a942e..a0f2f82 100644
--- a/debuggerd/proto/tombstone.proto
+++ b/debuggerd/proto/tombstone.proto
@@ -123,12 +123,13 @@
   string name = 2;
   repeated Register registers = 3;
   repeated string backtrace_note = 7;
+  repeated string unreadable_elf_files = 9;
   repeated BacktraceFrame current_backtrace = 4;
   repeated MemoryDump memory_dump = 5;
   int64 tagged_addr_ctrl = 6;
   int64 pac_enabled_keys = 8;
 
-  reserved 9 to 999;
+  reserved 10 to 999;
 }
 
 message BacktraceFrame {
diff --git a/fs_mgr/libsnapshot/snapuserd/snapuserd_daemon.cpp b/fs_mgr/libsnapshot/snapuserd/snapuserd_daemon.cpp
index 0b88567..c31772b 100644
--- a/fs_mgr/libsnapshot/snapuserd/snapuserd_daemon.cpp
+++ b/fs_mgr/libsnapshot/snapuserd/snapuserd_daemon.cpp
@@ -223,8 +223,6 @@
 int main(int argc, char** argv) {
     android::base::InitLogging(argv, &android::base::KernelLogger);
 
-    LOG(INFO) << "snapuserd daemon about to start";
-
     android::snapshot::Daemon& daemon = android::snapshot::Daemon::Instance();
 
     if (!daemon.StartDaemon(argc, argv)) {
diff --git a/init/README.md b/init/README.md
index c82dbfb..13c6ebd 100644
--- a/init/README.md
+++ b/init/README.md
@@ -804,13 +804,18 @@
 `init.svc.<name>`
 > State of a named service ("stopped", "stopping", "running", "restarting")
 
-`dev.mnt.blk.<mount_point>`
+`dev.mnt.dev.<mount_point>`, `dev.mnt.blk.<mount_point>`, `dev.mnt.rootdisk.<mount_point>`
 > Block device base name associated with a *mount_point*.
   The *mount_point* has / replaced by . and if referencing the root mount point
-  "/", it will use "/root", specifically `dev.mnt.blk.root`.
-  Meant for references to `/sys/device/block/${dev.mnt.blk.<mount_point>}/` and
-  `/sys/fs/ext4/${dev.mnt.blk.<mount_point>}/` to tune the block device
-  characteristics in a device agnostic manner.
+  "/", it will use "/root".
+  `dev.mnt.dev.<mount_point>` indicates a block device attached to filesystems.
+    (e.g., dm-N or sdaN/mmcblk0pN to access `/sys/fs/ext4/${dev.mnt.dev.<mount_point>}/`)
+
+  `dev.mnt.blk.<mount_point>` indicates the disk partition to the above block device.
+    (e.g., sdaN / mmcblk0pN to access `/sys/class/block/${dev.mnt.blk.<mount_point>}/`)
+
+  `dev.mnt.rootdisk.<mount_point>` indicates the root disk to contain the above disk partition.
+    (e.g., sda / mmcblk0 to access `/sys/class/block/${dev.mnt.rootdisk.<mount_point>}/queue`)
 
 Init responds to properties that begin with `ctl.`.  These properties take the format of
 `ctl.[<target>_]<command>` and the _value_ of the system property is used as a parameter.  The
diff --git a/init/init.cpp b/init/init.cpp
index 9616805..5a0b3a6 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -33,7 +33,6 @@
 #define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
 #include <sys/_system_properties.h>
 
-#include <filesystem>
 #include <functional>
 #include <map>
 #include <memory>
@@ -47,7 +46,6 @@
 #include <android-base/logging.h>
 #include <android-base/parseint.h>
 #include <android-base/properties.h>
-#include <android-base/scopeguard.h>
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 #include <backtrace/Backtrace.h>
@@ -580,12 +578,29 @@
     HandlePowerctlMessage("shutdown,container");
 }
 
+static constexpr std::chrono::milliseconds kDiagnosticTimeout = 10s;
+
 static void HandleSignalFd() {
     signalfd_siginfo siginfo;
-    ssize_t bytes_read = TEMP_FAILURE_RETRY(read(signal_fd, &siginfo, sizeof(siginfo)));
-    if (bytes_read != sizeof(siginfo)) {
-        PLOG(ERROR) << "Failed to read siginfo from signal_fd";
-        return;
+    auto started = std::chrono::steady_clock::now();
+    for (;;) {
+        ssize_t bytes_read = TEMP_FAILURE_RETRY(read(signal_fd, &siginfo, sizeof(siginfo)));
+        if (bytes_read < 0 && errno == EAGAIN) {
+            auto now = std::chrono::steady_clock::now();
+            std::chrono::duration<double> waited = now - started;
+            if (waited >= kDiagnosticTimeout) {
+                LOG(ERROR) << "epoll() woke us up, but we waited with no SIGCHLD!";
+                started = now;
+            }
+
+            std::this_thread::sleep_for(100ms);
+            continue;
+        }
+        if (bytes_read != sizeof(siginfo)) {
+            PLOG(ERROR) << "Failed to read siginfo from signal_fd";
+            return;
+        }
+        break;
     }
 
     switch (siginfo.ssi_signo) {
@@ -641,7 +656,7 @@
         LOG(FATAL) << "Failed to register a fork handler: " << strerror(result);
     }
 
-    signal_fd = signalfd(-1, &mask, SFD_CLOEXEC);
+    signal_fd = signalfd(-1, &mask, SFD_CLOEXEC | SFD_NONBLOCK);
     if (signal_fd == -1) {
         PLOG(FATAL) << "failed to create signalfd";
     }
@@ -776,82 +791,6 @@
     return {};
 }
 
-static bool SystemReadSmokeTest() {
-    std::string dev = "/dev/block/mapper/system"s + fs_mgr_get_slot_suffix();
-    android::base::unique_fd fd(open(dev.c_str(), O_RDONLY));
-    if (fd < 0) {
-        PLOG(ERROR) << "open " << dev << " failed, will not diangose snapuserd hangs";
-        return false;
-    }
-
-    for (size_t i = 1; i <= 100; i++) {
-        // Skip around the partition a bit.
-        size_t offset = i * 4096 * 512;
-
-        char b;
-        ssize_t n = TEMP_FAILURE_RETRY(pread(fd.get(), &b, 1, offset));
-        if (n < 0) {
-            PLOG(ERROR) << "snapuserd smoke test read failed";
-            return false;
-        }
-    }
-    return true;
-}
-
-static void DiagnoseSnapuserdHang(pid_t pid) {
-    bool succeeded = false;
-
-    std::mutex m;
-    std::condition_variable cv;
-
-    // Enforce an ordering between this and the thread startup, by taking the
-    // lock before we lanuch the thread.
-    std::unique_lock<std::mutex> cv_lock(m);
-
-    std::thread t([&]() -> void {
-        std::lock_guard<std::mutex> lock(m);
-        succeeded = SystemReadSmokeTest();
-        cv.notify_all();
-    });
-
-    auto join = android::base::make_scope_guard([&]() -> void {
-        // If the smoke test is hung, then this will too. We expect the device to
-        // automatically reboot once the watchdog kicks in.
-        t.join();
-    });
-
-    auto now = std::chrono::system_clock::now();
-    auto deadline = now + 10s;
-    auto status = cv.wait_until(cv_lock, deadline);
-    if (status == std::cv_status::timeout) {
-        LOG(ERROR) << "snapuserd smoke test timed out";
-    } else if (!succeeded) {
-        LOG(ERROR) << "snapuserd smoke test failed";
-    }
-
-    if (succeeded) {
-        LOG(INFO) << "snapuserd smoke test succeeded";
-        return;
-    }
-
-    while (true) {
-        LOG(ERROR) << "snapuserd problem detected, printing open fds";
-
-        std::error_code ec;
-        std::string proc_dir = "/proc/" + std::to_string(pid) + "/fd";
-        for (const auto& entry : std::filesystem::directory_iterator(proc_dir)) {
-            std::string target;
-            if (android::base::Readlink(entry.path(), &target)) {
-                LOG(ERROR) << "snapuserd opened: " << target;
-            } else {
-                LOG(ERROR) << "snapuserd opened: " << entry.path();
-            }
-        }
-
-        std::this_thread::sleep_for(10s);
-    }
-}
-
 int SecondStageMain(int argc, char** argv) {
     if (REBOOT_BOOTLOADER_ON_PANIC) {
         InstallRebootSignalHandlers();
@@ -865,11 +804,6 @@
     InitKernelLogging(argv);
     LOG(INFO) << "init second stage started!";
 
-    if (auto pid = GetSnapuserdFirstStagePid()) {
-        std::thread t(DiagnoseSnapuserdHang, *pid);
-        t.detach();
-    }
-
     // Update $PATH in the case the second stage init is newer than first stage init, where it is
     // first set.
     if (setenv("PATH", _PATH_DEFPATH, 1) != 0) {
@@ -1021,7 +955,7 @@
     setpriority(PRIO_PROCESS, 0, 0);
     while (true) {
         // By default, sleep until something happens.
-        auto epoll_timeout = std::optional<std::chrono::milliseconds>{};
+        auto epoll_timeout = std::optional<std::chrono::milliseconds>{kDiagnosticTimeout};
 
         auto shutdown_command = shutdown_state.CheckShutdown();
         if (shutdown_command) {
@@ -1061,6 +995,13 @@
             for (const auto& function : *pending_functions) {
                 (*function)();
             }
+        } else if (Service::is_exec_service_running()) {
+            std::chrono::duration<double> waited =
+                    std::chrono::steady_clock::now() - Service::exec_service_started();
+            if (waited >= kDiagnosticTimeout) {
+                LOG(ERROR) << "Exec service is hung? Waited " << waited.count()
+                           << " without SIGCHLD";
+            }
         }
         if (!IsShuttingDown()) {
             HandleControlMessages();
diff --git a/init/mount_handler.cpp b/init/mount_handler.cpp
index f0d8d45..227ce2f 100644
--- a/init/mount_handler.cpp
+++ b/init/mount_handler.cpp
@@ -25,6 +25,7 @@
 #include <unistd.h>
 
 #include <algorithm>
+#include <filesystem>
 #include <string>
 #include <utility>
 #include <vector>
@@ -32,6 +33,7 @@
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <android-base/properties.h>
+#include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 #include <fs_mgr.h>
 #include <fstab/fstab.h>
@@ -39,6 +41,9 @@
 
 #include "epoll.h"
 
+using android::base::Basename;
+using android::base::StringPrintf;
+
 namespace android {
 namespace init {
 
@@ -67,41 +72,82 @@
     return MountHandlerEntry(fields[0], fields[1], fields[2]);
 }
 
+// return sda25 for dm-4, sda25 for sda25, or mmcblk0p24 for mmcblk0p24
+std::string GetDiskPart(std::string blockdev) {
+    if (blockdev.find('/') != std::string::npos) return {};
+
+    while (android::base::StartsWith(blockdev, "dm-")) {
+        auto& dm = dm::DeviceMapper::Instance();
+        std::optional<std::string> parent = dm.GetParentBlockDeviceByPath("/dev/block/" + blockdev);
+        if (parent) {
+            blockdev = android::base::Basename(*parent);
+        } else {
+            return {};
+        }
+    }
+    return blockdev;
+}
+
+// return sda for sda25, or mmcblk0 for mmcblk0p24
+std::string GetRootDisk(std::string blockdev) {
+    if (blockdev.empty()) return {};
+    if (blockdev.find('/') != std::string::npos) return {};
+
+    std::error_code ec;
+    for (const auto& entry : std::filesystem::directory_iterator("/sys/block", ec)) {
+        const std::string path = entry.path().string();
+        if (std::filesystem::exists(StringPrintf("%s/%s", path.c_str(), blockdev.c_str()))) {
+            return Basename(path);
+        }
+    }
+    return {};
+}
+
 void SetMountProperty(const MountHandlerEntry& entry, bool add) {
     static constexpr char devblock[] = "/dev/block/";
     if (!android::base::StartsWith(entry.blk_device, devblock)) return;
-    std::string value;
+    auto target = entry.blk_device.substr(strlen(devblock));
+    std::string diskpart, rootdisk;
     if (add) {
-        value = entry.blk_device.substr(strlen(devblock));
-        if (android::base::StartsWith(value, "sd")) {
-            // All sd partitions inherit their queue characteristics
-            // from the whole device reference.  Strip partition number.
-            auto it = std::find_if(value.begin(), value.end(), [](char c) { return isdigit(c); });
-            if (it != value.end()) value.erase(it, value.end());
-        }
-        auto queue = "/sys/block/" + value + "/queue";
+        diskpart = GetDiskPart(target);
+        rootdisk = GetRootDisk(diskpart);
+
         struct stat sb;
-        if (stat(queue.c_str(), &sb) || !S_ISDIR(sb.st_mode)) value = "";
-        if (stat(entry.mount_point.c_str(), &sb) || !S_ISDIR(sb.st_mode)) value = "";
+        if (stat(entry.mount_point.c_str(), &sb) || !S_ISDIR(sb.st_mode)) rootdisk = "";
         // Clear the noise associated with loopback and APEX.
-        if (android::base::StartsWith(value, "loop")) value = "";
-        if (android::base::StartsWith(entry.mount_point, "/apex/")) value = "";
+        if (android::base::StartsWith(target, "loop")) rootdisk = "";
+        if (android::base::StartsWith(entry.mount_point, "/apex/")) rootdisk = "";
     }
     auto mount_prop = entry.mount_point;
     if (mount_prop == "/") mount_prop = "/root";
     std::replace(mount_prop.begin(), mount_prop.end(), '/', '.');
     auto blk_mount_prop = "dev.mnt.blk" + mount_prop;
     auto dev_mount_prop = "dev.mnt.dev" + mount_prop;
-    // Set property even if its value does not change to trigger 'on property:'
+    auto rootdisk_mount_prop = "dev.mnt.rootdisk" + mount_prop;
+    // Set property even if its rootdisk does not change to trigger 'on property:'
     // handling, except for clearing non-existent or already clear property.
     // Goal is reduction of empty properties and associated triggers.
-    if (value.empty() && android::base::GetProperty(blk_mount_prop, "").empty()) return;
-    android::base::SetProperty(blk_mount_prop, value);
-    if (!value.empty()) {
-        android::base::SetProperty(dev_mount_prop, entry.blk_device.substr(strlen(devblock)));
-    } else {
+    if (rootdisk.empty() && android::base::GetProperty(blk_mount_prop, "").empty()) return;
+
+    if (rootdisk.empty()) {
+        android::base::SetProperty(blk_mount_prop, "");
         android::base::SetProperty(dev_mount_prop, "");
+        android::base::SetProperty(rootdisk_mount_prop, "");
+        return;
     }
+
+    // 1. dm-N
+    //  dev.mnt.dev.data = dm-N
+    //  dev.mnt.blk.data = sdaN or mmcblk0pN
+    //  dev.mnt.rootdisk.data = sda or mmcblk0
+    //
+    // 2. sdaN or mmcblk0pN
+    //  dev.mnt.dev.data = sdaN or mmcblk0pN
+    //  dev.mnt.blk.data = sdaN or mmcblk0pN
+    //  dev.mnt.rootdisk.data = sda or mmcblk0
+    android::base::SetProperty(dev_mount_prop, target);
+    android::base::SetProperty(blk_mount_prop, diskpart);
+    android::base::SetProperty(rootdisk_mount_prop, rootdisk);
 }
 
 }  // namespace
diff --git a/init/service.cpp b/init/service.cpp
index 8a9cc0a..2ebf87e 100644
--- a/init/service.cpp
+++ b/init/service.cpp
@@ -127,6 +127,7 @@
 
 unsigned long Service::next_start_order_ = 1;
 bool Service::is_exec_service_running_ = false;
+std::chrono::time_point<std::chrono::steady_clock> Service::exec_service_started_;
 
 Service::Service(const std::string& name, Subcontext* subcontext_for_restart_commands,
                  const std::vector<std::string>& args, bool from_apex)
@@ -388,6 +389,7 @@
 
     flags_ |= SVC_EXEC;
     is_exec_service_running_ = true;
+    exec_service_started_ = std::chrono::steady_clock::now();
 
     LOG(INFO) << "SVC_EXEC service '" << name_ << "' pid " << pid_ << " (uid " << proc_attr_.uid
               << " gid " << proc_attr_.gid << "+" << proc_attr_.supp_gids.size() << " context "
diff --git a/init/service.h b/init/service.h
index 3f12aa2..d233cbf 100644
--- a/init/service.h
+++ b/init/service.h
@@ -102,6 +102,9 @@
     size_t CheckAllCommands() const { return onrestart_.CheckAllCommands(); }
 
     static bool is_exec_service_running() { return is_exec_service_running_; }
+    static std::chrono::time_point<std::chrono::steady_clock> exec_service_started() {
+        return exec_service_started_;
+    }
 
     const std::string& name() const { return name_; }
     const std::set<std::string>& classnames() const { return classnames_; }
@@ -154,6 +157,8 @@
 
     static unsigned long next_start_order_;
     static bool is_exec_service_running_;
+    static std::chrono::time_point<std::chrono::steady_clock> exec_service_started_;
+    static pid_t exec_service_pid_;
 
     std::string name_;
     std::set<std::string> classnames_;
diff --git a/libprocessgroup/processgroup.cpp b/libprocessgroup/processgroup.cpp
index 76d5e13..96b5537 100644
--- a/libprocessgroup/processgroup.cpp
+++ b/libprocessgroup/processgroup.cpp
@@ -442,8 +442,8 @@
 
     struct stat cgroup_stat;
     mode_t cgroup_mode = 0750;
-    gid_t cgroup_uid = AID_SYSTEM;
-    uid_t cgroup_gid = AID_SYSTEM;
+    uid_t cgroup_uid = AID_SYSTEM;
+    gid_t cgroup_gid = AID_SYSTEM;
     int ret = 0;
 
     if (stat(cgroup.c_str(), &cgroup_stat) == 1) {
diff --git a/libprocessgroup/profiles/cgroups.json b/libprocessgroup/profiles/cgroups.json
index 0634220..3e4393d 100644
--- a/libprocessgroup/profiles/cgroups.json
+++ b/libprocessgroup/profiles/cgroups.json
@@ -3,7 +3,7 @@
     {
       "Controller": "blkio",
       "Path": "/dev/blkio",
-      "Mode": "0755",
+      "Mode": "0775",
       "UID": "system",
       "GID": "system"
     },
@@ -32,16 +32,13 @@
   ],
   "Cgroups2": {
     "Path": "/sys/fs/cgroup",
-    "Mode": "0755",
+    "Mode": "0775",
     "UID": "system",
     "GID": "system",
     "Controllers": [
       {
         "Controller": "freezer",
-        "Path": ".",
-        "Mode": "0755",
-        "UID": "system",
-        "GID": "system"
+        "Path": "."
       }
     ]
   }
diff --git a/rootdir/init.rc b/rootdir/init.rc
index c4c9eca..404d7ae 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -1085,9 +1085,11 @@
     mkdir /dev/sys/fs/by-name 0755 system system
     symlink /sys/fs/f2fs/${dev.mnt.dev.data} /dev/sys/fs/by-name/userdata
 
-    # to access dm-<num> sysfs
+    # dev.mnt.dev.data=dm-N, dev.mnt.blk.data=sdaN/mmcblk0pN, dev.mnt.rootdisk.data=sda/mmcblk0, or
+    # dev.mnt.dev.data=sdaN/mmcblk0pN, dev.mnt.blk.data=sdaN/mmcblk0pN, dev.mnt.rootdisk.data=sda/mmcblk0
     mkdir /dev/sys/block/by-name 0755 system system
-    symlink /sys/devices/virtual/block/${dev.mnt.dev.data} /dev/sys/block/by-name/userdata
+    symlink /sys/class/block/${dev.mnt.dev.data} /dev/sys/block/by-name/userdata
+    symlink /sys/class/block/${dev.mnt.rootdisk.data} /dev/sys/block/by-name/rootdisk
 
     # F2FS tuning. Set cp_interval larger than dirty_expire_centisecs, 30 secs,
     # to avoid power consumption when system becomes mostly idle. Be careful
@@ -1099,8 +1101,9 @@
 
     # limit discard size to 128MB in order to avoid long IO latency
     # for filesystem tuning first (dm or sda)
-    # Note that, if dm-<num> is used, sda/mmcblk0 should be tuned in vendor/init.rc
+    # this requires enabling selinux entry for sda/mmcblk0 in vendor side
     write /dev/sys/block/by-name/userdata/queue/discard_max_bytes 134217728
+    write /dev/sys/block/by-name/rootdisk/queue/discard_max_bytes 134217728
 
     # Permissions for System Server and daemons.
     chown system system /sys/power/autosleep
diff --git a/trusty/libtrusty/include/trusty/ipc.h b/trusty/libtrusty/include/trusty/ipc.h
index 1fa6fe4..04e84c6 100644
--- a/trusty/libtrusty/include/trusty/ipc.h
+++ b/trusty/libtrusty/include/trusty/ipc.h
@@ -23,15 +23,19 @@
 
 /**
  * enum transfer_kind - How to send an fd to Trusty
- * @TRUSTY_SHARE: Memory will be accessible by Linux and Trusty. On ARM it will
- *                be mapped as nonsecure. Suitable for shared memory. The paired
- *                fd must be a "memfd".
- * @TRUSTY_LEND:  Memory will be accessible only to Trusty. On ARM it will be
- *                transitioned to "Secure" memory if Trusty is in TrustZone.
- *                This transfer kind is suitable for donating video buffers or
- *                other similar resources. The paired fd may need to come from a
- *                platform-specific allocator for memory that may be
- *                transitioned to "Secure".
+ * @TRUSTY_SHARE:       Memory will be accessible by Linux and Trusty. On ARM it
+ *                      will be mapped as nonsecure. Suitable for shared memory.
+ *                      The paired fd must be a "dma_buf".
+ * @TRUSTY_LEND:        Memory will be accessible only to Trusty. On ARM it will
+ *                      be transitioned to "Secure" memory if Trusty is in
+ *                      TrustZone. This transfer kind is suitable for donating
+ *                      video buffers or other similar resources. The paired fd
+ *                      may need to come from a platform-specific allocator for
+ *                      memory that may be transitioned to "Secure".
+ * @TRUSTY_SEND_SECURE: Send memory that is already "Secure". Memory will be
+ *                      accessible only to Trusty. The paired fd may need to
+ *                      come from a platform-specific allocator that returns
+ *                      "Secure" buffers.
  *
  * Describes how the user would like the resource in question to be sent to
  * Trusty. Options may be valid only for certain kinds of fds.
@@ -39,6 +43,7 @@
 enum transfer_kind {
     TRUSTY_SHARE = 0,
     TRUSTY_LEND = 1,
+    TRUSTY_SEND_SECURE = 2,
 };
 
 /**